Science.gov

Sample records for metallic driver fuel

  1. EBR-II metallic driver fuel - a live option

    SciTech Connect

    Seidel, B.R.; Walters, L.C.

    1981-10-01

    The exceptional performance of metallic driver fuel has been demonstrated by the irradiation of a large number of Experimental Breeder Reactor II (EBR-II) driver-fuel elements of uranium-5 wt percent fissium clad in austenitic stainless steel. High burnup with high reliability has been achieved by a close coupling of element design and materials selection. The irradiation performance has been improved by decreasing the fuel smear density, increasing the plenum volume, increasing the cladding thickness, and selecting a higher-strength, lower-swelling cladding alloy which exhibits less fuel-cladding chemical interaction. Quantification of reliability has allowed full utilization of the element lifetime. Lifetimes much greater than 10 at. percent could be achieved by a design change of the restrainer, which currently limits life. Use of U-Pu-Zr fuel alloy with current cladding material would provide higher-temperature capability. Metallic fuel systems with their inherently superior breeding and irradiation performance are a capable and attractive next-generation power systems. 19 refs.

  2. Fuel-Cell Drivers Wanted

    ERIC Educational Resources Information Center

    Clark, Todd; Jones, Rick

    2004-01-01

    While the political climate seems favorable for the development of fuel-cell vehicles for personal transportation, the market's demand may not be so favorable. Nonetheless, middle level students will be the next generation of drivers and voters, and they need to be able to make informed decisions regarding the nation's energy and transportation…

  3. Fuel-Cell Drivers Wanted

    ERIC Educational Resources Information Center

    Clark, Todd; Jones, Rick

    2004-01-01

    While the political climate seems favorable for the development of fuel-cell vehicles for personal transportation, the market's demand may not be so favorable. Nonetheless, middle level students will be the next generation of drivers and voters, and they need to be able to make informed decisions regarding the nation's energy and transportation…

  4. Recent metal fuel safety tests in TREAT

    SciTech Connect

    Wright, A.E.; Bauer, T.H.; Lo, R.K.; Robinson, W.R.; Palm, R.G.

    1986-01-01

    In-reactor safety tests have been performed on metal-alloy reactor fuel to study its response to transient-overpower conditions, in particular, the margin to cladding breach and the axial self-extrusion of fuel within intact cladding. Uranium-fissium EBR-II driver fuel elements of several burnups were tested, some to cladding breach and others to incipient breach. Transient fuel motions were monitored, and time and location of breach were measured. The test results and computations of fuel extrusion and cladding failure in metal-alloy fuel are described.

  5. Analysis of IFR driver fuel hot channel factors

    SciTech Connect

    Ku, J.Y.; Chang, L.K.; Mohr, D.

    1994-03-01

    Thermal-hydraulic uncertainty factors for Integral Fast Reactor (IFR) driver fuels have been determined based primarily on the database obtained from the predecessor fuels used in the IFR prototype, Experimental Breeder Reactor II. The uncertainty factors were applied to the channel factors (HCFs) analyses to obtain separate overall HCFs for fuel and cladding for steady-state analyses. A ``semistatistical horizontal method`` was used in the HCFs analyses. The uncertainty factor of the fuel thermal conductivity dominates the effects considered in the HCFs analysis; the uncertainty in fuel thermal conductivity will be reduced as more data are obtained to expand the currently limited database for the IFR ternary metal fuel (U-20Pu-10Zr). A set of uncertainty factors to be used for transient analyses has also been derived.

  6. Metallic fuel safety assessment

    SciTech Connect

    Bauer, T. H.; Cahalan, J. E.; Dunn, F. E.; Fenske, G. R.; Gabor, J. D.; Gruber, E. E.; Hughes, T. H.; Kalimullah, none; Kramer, J. M.; Miles, K. J.; Pedersen, D. R.; Spencer, B. W.; Tentner, A. M.; Tilbrook, R. W.; Wright, A. E.

    1989-02-01

    A survey of experimental and analytical results from the Integral Fast Reactor (IFR) safety program are presented, with a focus on metallic fuel safety performance. Experimental results from laboratory and in-pile tests are reviewed. Models of metallic fuel behavior for prediction of performance in reactor transients and accidents are summarized. Analyses of metallic fuel response in design basis accidents and anticipated transients without scram are presented. The experimental and analytical databases demonstrate the superior safety performance of metallic fuel in IFR design concepts.

  7. Off-normal performance of EBR-II (Experimental Breeder Reactor) driver fuel

    SciTech Connect

    Seidel, B.R.; Batte, G.L.; Lahm, C.E.; Fryer, R.M.; Koenig, J.F.; Hofman, G.L.

    1986-09-01

    The off-normal performance of EBR-II Mark-II driver fuel has been more than satisfactory as demonstrated by robust reliability under repeated transient overpower and undercooled loss-of-flow tests, by benign run-beyond-cladding-breach behavior, and by forgiving response to fabrication defects including lack of bond. Test results have verified that the metallic driver fuel is very tolerant of off-normal events. This behavior has allowed EBR-II to operate in a combined steady-state and transient mode to provide test capability without limitation from the metallic driver fuel.

  8. Processing of driver fuel assemblies at FFTF

    SciTech Connect

    Danko, A.D.; Hicks, D.F.; Arneson, S.O.

    1982-07-01

    The ability to disassemble an irradiated Fast Flux Test Facility (FFTF) Driver Fuel Assembly (DFA) is important both to the continued operation of the FFTF and the future of the Breeder Reactor Program. At the FFTF, DFA's with up to three (3)* kilowatts of decay heat will be placed in the Interim Examination and Maintenance (IEM) Cell for disassembly and nondestructive examination. This process includes sodium removal, duct measurement, duct cutting and pulling, fuel pin removal, and component disposition to other laboratories for destructive examination.

  9. Metallic fuel development

    SciTech Connect

    Walters, L.C.

    1987-01-01

    Metallic fuels are capable of achieving high burnup as a result of design modifications instituted in the late 1960's. The gap between the fuel slug and the cladding is fixed such that by the time the fuel swells to the cladding the fission gas bubbles interconnect and release the fission gas to an appropriately sized plenum volume. Interconnected porosity thus provides room for the fuel to deform from further swelling rather than stress the cladding. In addition, the interconnected porosity allows the fuel pin to be tolerant to transient events because as stresses are generated during a transient event the fuel flows rather than applying significant stress to the cladding. Until 1969 a number of metallic fuel alloys were under development in the US. At that time the metallic fuel development program in the US was discontinued in favor of ceramic fuels. However, development had proceeded to the point where it was clear that the zirconium addition to uranium-plutonium fuel would yield a ternary fuel with an adequately high solidus temperature and good compatibility with austenitic stainless steel cladding. Furthermore, several U-Pu-Zr fuel pins had achieved about 6 at.% bu by the late 1960's, without failure, and thus the prospect for high burnup was promising.

  10. Development of an LMR core design using metallic fuel

    SciTech Connect

    Orechwa, Y.; Yang, S.T.

    1986-01-01

    The design and performance of a metal fueled LMR core at the 900 MWth power level is described. Performance measures of preliminary driver and blanket fuel pin designs are calculated with the developmental fuel performance code LIFE-metal. The robustness of the designs to changes in design parameters is shown with respect to plenum length, cladding thickness and cladding temperature.

  11. Metallic fuels handbook

    SciTech Connect

    Hofman, G. L.; Leibowitz, L.; Kramer, J. M.; Billone, M. C.; Koenig, J. F.

    1985-11-01

    This compilation of Thermophysical and Mechanical Properties of certain metallic fuels is meant to be used as a common source of data in work related to the Integral Fast Reactor. This handbook focuses on the two fuel compositions chosen for the IFR; namely, Uranium-Zirconium and Uranium-Plutonium-Zirconium.

  12. Metallic fuels for advanced reactors

    NASA Astrophysics Data System (ADS)

    Carmack, W. J.; Porter, D. L.; Chang, Y. I.; Hayes, S. L.; Meyer, M. K.; Burkes, D. E.; Lee, C. B.; Mizuno, T.; Delage, F.; Somers, J.

    2009-07-01

    In the framework of the Generation IV Sodium Fast Reactor Program, the Advanced Fuel Project has conducted an evaluation of the available fuel systems supporting future sodium cooled fast reactors. This paper presents an evaluation of metallic alloy fuels. Early US fast reactor developers originally favored metal alloy fuel due to its high fissile density and compatibility with sodium. The goal of fast reactor fuel development programs is to develop and qualify a nuclear fuel system that performs all of the functions of a conventional fast spectrum nuclear fuel while destroying recycled actinides. This will provide a mechanism for closure of the nuclear fuel cycle. Metal fuels are candidates for this application, based on documented performance of metallic fast reactor fuels and the early results of tests currently being conducted in US and international transmutation fuel development programs.

  13. Factors controlling metal fuel lifetime

    SciTech Connect

    Porter, D.L.; Hofman, G.L.; Seidel, B.R.; Walters, L.C.

    1986-01-01

    The reliability of metal fuel elements is determined by a fuel burnup at which a statistically predicted number of fuel breaches would occur, the number of breaches determined by the amount of free fission gas which a particular reactor design can tolerate. The reliability is therefore measured using experimentally determined breach statistics, or by modelling fuel element behavior and those factors which contribute to cladding breach. The factors are fuel/cladding mechanical and chemical interactions, fission gas pressure, fuel phase transformations involving volume changes, and fission product effects on cladding integrity. Experimental data for EBR-II fuel elements has shown that the primary, and perhaps the only significant factor affecting metal fuel reliability, is the pressure-induced stresses caused by fission gas release. Other metal fuel/cladding systems may perform similarly.

  14. Irradiation behavior of experimental Mark-II Experimental Breeder Reactor II driver fuel

    SciTech Connect

    Hofman, G.L.

    1980-01-01

    Prototypic driver-fuel elements using metallic fuel and stainless-steel cladding, designed to achieve a high burnup, were tested in the Experimental Breeder Reactor II. The irradiation results showed that burnup of up to 10 at.% can be attained without cladding failure and that cladding deformation can be kept to acceptable values if Type 316 stainless steel is used as the cladding material.

  15. Recent progress in the development of metallic fuel

    SciTech Connect

    Seidel, B.R.; Batte, G.L.; Dodds, N.E.; Lahm, C.E.; Pahl, R.G. ); Tsai, H.C. )

    1990-01-01

    Tests to date demonstrate that metallic fuel for advanced liquid metal reactors performs well, is easily reprocessed and refabricated and provides inherent reactor safety within an economic design. The behavior and performance of metallic fuel is key to the demonstration of the Integral Fast Reactor (IFR) concept at Argonne National Laboratory. Since 1985, more than 40 assemblies of experimental fuel in addition to the standard metallic driver fuel for Experimental Breeder Reactor 2 (EBR-2)have been irradiated; several more continue to be designed and fabricated. Results have characterized the influence of a wide range of fabrication, design and material variables upon irradiation behavior throughout the fuel lifetime under normal and upset conditions including operation with breached cladding. Results of test, both in- and out-of-reactor, indicate that metallic fuel is readily and economically fabricated, capable of achieving high exposure and long reactor residence times, and possesses unique and promising safety features. 9 refs., 6 figs.

  16. Analyzing Vehicle Fuel Saving Opportunities through Intelligent Driver Feedback

    SciTech Connect

    Gonder, J.; Earleywine, M.; Sparks, W.

    2012-06-01

    Driving style changes, e.g., improving driver efficiency and motivating driver behavior changes, could deliver significant petroleum savings. This project examines eliminating stop-and-go driving and unnecessary idling, and also adjusting acceleration rates and cruising speeds to ideal levels to quantify fuel savings. Such extreme adjustments can result in dramatic fuel savings of over 30%, but would in reality only be achievable through automated control of vehicles and traffic flow. In real-world driving, efficient driving behaviors could reduce fuel use by 20% on aggressively driven cycles and by 5-10% on more moderately driven trips. A literature survey was conducted of driver behavior influences, and pertinent factors from on-road experiments with different driving styles were observed. This effort highlighted important driver influences such as surrounding vehicle behavior, anxiety over trying to get somewhere quickly, and the power/torque available from the vehicle. Existing feedback approaches often deliver efficiency information and instruction. Three recommendations for maximizing fuel savings from potential drive cycle improvement are: (1) leveraging applications with enhanced incentives, (2) using an approach that is easy and widely deployable to motivate drivers, and (3) utilizing connected vehicle and automation technologies to achieve large and widespread efficiency improvements.

  17. Electrorefining Experience For Pyrochemical Reprocessing of Spent EBR-II Driver Fuel

    SciTech Connect

    S. X. Li; T. A. Johnson; B. R. Westphal; K. M. Goff; R. W. Benedict

    2005-10-01

    Pyrochemical processing has been implemented for the treatment of spent fuel from the Experimental Breeder Reactor-II (EBR-II) at Idaho National Laboratory since 1996. This report summarizes technical advancements made in electrorefining of spent EBR-II driver fuel in the Mk-IV electrorefiner since the pyrochemical processing was integrated into the AFCI program in 2002. The significant advancements include improving uranium dissolution and noble metal retention from chopped fuel segments, increasing cathode current efficiency, and achieving co-collection of zirconium along with uranium from the cadmium pool.

  18. Hybrid combustion with metallized fuels

    NASA Technical Reports Server (NTRS)

    Yi, Jianwen; Wygle, Brian S.; Bates, Ronald W.; Jones, Michael D.; Ramohalli, Kumar

    1993-01-01

    A chemical method of adding certain catalysts to improve the degradation process of a solid fuel is discussed. Thermogravimetric (TGA) analysis used to study the fundamental degradation behavior of a typical hybrid fuel (HTPB) shows that high surface temperatures increase the degradation rate. Fuels were tested in a laboratory-scale experimental hybrid rocket and their behavior was compared to a baseline behavior of HTPB fuel regression rates. It was found that a small amount of metal powder added to the fuel can significantly increase the regression rates.

  19. Final Report on the Fuel Saving Effectiveness of Various Driver Feedback Approaches

    SciTech Connect

    Gonder, J.; Earleywine, M.; Sparks, W.

    2011-03-01

    This final report quantifies the fuel-savings opportunities from specific driving behavior changes, identifies factors that influence drivers' receptiveness to adopting fuel-saving behaviors, and assesses various driver feedback approaches.

  20. Determining Bond Sodium Remaining in Plenum Region of Spent Nuclear Driver Fuel

    SciTech Connect

    D. Vaden; S. X. Li

    2008-06-01

    The Fuel Conditioning Facility (FCF) at the Idaho National Laboratory (INL) treats spent nuclear fuel using an electro-chemical process that separates the uranium from the fission products, sodium thermal bond, and cladding materials [REF 1]. Upon immersion into the ER electrolyte, the sodium used to thermally bond the fuel to the clad jacket chemically reacts with the UCl3 in the electrolyte producing NaCl and uranium metal. The uranium in the spent fuel is separated from the cladding and fission products by taking advantage of the electro-chemical potential differences between uranium and the other fuel components. Assuming all the sodium in the thermal bond is converted to NaCl in the ER, the difference between the cumulative bond sodium mass in the fuel elements and the cumulative sodium mass found in the driver ER electrolyte inventory provides an upper mass limit for the sodium that migrated to the upper gas region, or plenum section, of the fuel element during irradiation in the reactor. The plenums are to be processed as metal waste via melting and metal consolidation operations. However, depending on the amount of sodium in the plenums, additional processing may be required to remove the sodium before metal waste processing.

  1. Investigation of vehicle and driver aggressivity and relation to fuel economy testing

    NASA Astrophysics Data System (ADS)

    Stichter, Jonathan Seth

    As vehicle technologies continue to improve it is becoming more evident one of the last major factors impacting fuel economy left today is the driver. In this study the driver is defined as the operator of a vehicle and the difference between driving styles of the driver and vehicle is defined as aggressivity. Driver aggressivity is proven to have a substantial impact on fuel economy in many studies. Many fuel economy tests have been created, all to measure the fuel efficiency of today's vehicles and their related technologies. These tests typically require that the drivers be trained or experienced in fuel economy testing unless the impact of the driver on fuel economy is the variable being tested. It is also recommended, for certain tests, that the driver stay with the same vehicle for the tests entirety. Although these are the requirements, having the same trained drivers for the entirety of a fuel economy test may not always be a viable option. This leads to the question of, what impact can a set of drivers, who are asked to drive the same, have on fuel consumption during a fuel consumption test? The SAE J1321 Type II Fuel Consumption Test Procedure was followed on two identical trucks with two drivers that were untrained in fuel economy testing in order to answer this question. It was found in this particular study that the driver variability can impose up to a 10% fuel economy difference on shorter distance routes where the driver is kept the same. By increasing the distance of the route and swapping drivers variability in fuel economy reduced to 5%. It was shown by this particular test that the impact of the driver when asked to drive the same is minimal compared to real world results of up to 30%. A larger data set and more testing is still necessary to completely understand and validate the impact of the driver on fuel economy testing.

  2. Performance of HT9 clad metallic fuel at high temperature

    SciTech Connect

    Pahl, R.G.; Lahm, C.E.; Hayes, S.L.

    1992-12-01

    Steady-state testing of HT9 clad metallic fuel at high temperatures was initiated in EBR-II in November of 1987. At that time U-10 wt. % Zr fuel clad with the low-swelling ferritic/martensitic alloy HT9 was being considered as driver fuel options for both EBR-II and FFTF. The objective of the X447 test described here was to determine the lifetime of HT9 cladding when operated with metallic fuel at beginning of life inside wall temperatures approaching {approximately}660{degree}C. Though stress-temperature design limits for HT9 preclude its use for high burnup applications under these conditions due to excessive thermal creep, the X447 test was carried out to obtain data on high temperature breach phenomena involving metallic fuel since little data existed in that area.

  3. Performance of HT9 clad metallic fuel at high temperature

    SciTech Connect

    Pahl, R.G.; Lahm, C.E.; Hayes, S.L.

    1992-01-01

    Steady-state testing of HT9 clad metallic fuel at high temperatures was initiated in EBR-II in November of 1987. At that time U-10 wt. % Zr fuel clad with the low-swelling ferritic/martensitic alloy HT9 was being considered as driver fuel options for both EBR-II and FFTF. The objective of the X447 test described here was to determine the lifetime of HT9 cladding when operated with metallic fuel at beginning of life inside wall temperatures approaching [approximately]660[degree]C. Though stress-temperature design limits for HT9 preclude its use for high burnup applications under these conditions due to excessive thermal creep, the X447 test was carried out to obtain data on high temperature breach phenomena involving metallic fuel since little data existed in that area.

  4. EXTENDING SODIUM FAST REACTOR DRIVER FUEL USE TO HIGHER TEMPERATURES

    SciTech Connect

    Douglas L. Porter

    2011-02-01

    Calculations of potential sodium-cooled fast reactor fuel temperatures were performed to estimate the effects of increasing the outlet temperature of a given fast reactor design by increasing pin power, decreasing assembly flow, or increasing inlet temperature. Based upon experience in the U.S., both metal and mixed oxide (MOX) fuel types are discussed in terms of potential performance effects created by the increased operating temperatures. Assembly outlet temperatures of 600, 650 and 700 °C were used as goal temperatures. Fuel/cladding chemical interaction (FCCI) and fuel melting, as well as challenges to the mechanical integrity of the cladding material, were identified as the limiting phenomena. For example, starting with a recent 1000 MWth fast reactor design, raising the outlet temperature to 650 °C through pin power increase increased the MOX centerline temperature to more than 3300 °C and the metal fuel peak cladding temperature to more than 700 °C. These exceeded limitations to fuel performance; fuel melting was limiting for MOX and FCCI for metal fuel. Both could be alleviated by design ‘fixes’, such as using a barrier inside the cladding to minimize FCCI in the metal fuel, or using annular fuel in the case of MOX. Both would also require an advanced cladding material with improved stress rupture properties. While some of these are costly, the benefits of having a high-temperature reactor which can support hydrogen production, or other missions requiring high process heat may make the extra costs justified.

  5. Posttest examination results of recent treat tests on metal fuel

    SciTech Connect

    Holland, J.W.; Wright, A.E.; Bauer, T.H.; Goldman, A.J.; Klickman, A.E.; Sevy, R.H.

    1986-01-01

    A series of in-reactor transient tests is underway to study the characteristics of metal-alloy fuel during transient-overpower-without-scam conditions. The initial tests focused on determining the margin to cladding breach and the axial fuel motions that would mitigate the power excursion. The tests were conducted in flowing-sodium loops with uranium - 5% fissium EBR-II Mark-II driver fuel elements in the TREAT facility. Posttest examination of the tests evaluated fuel elongation in intact pins and postfailure fuel motion. Microscopic examination of the intact pins studied the nature and extent of fuel/cladding interaction, fuel melt fraction and mass distribution, and distribution of porosity. Eutectic penetration and failure of the cladding were also examined in the failed pins.

  6. EXPERIMENTAL LIQUID METAL FUEL REACTOR

    DOEpatents

    Happell, J.J.; Thomas, G.R.; Denise, R.P.; Bunts, J.L. Jr.

    1962-01-23

    A liquid metal fuel nuclear fission reactor is designed in which the fissionable material is dissolved or suspended in a liquid metal moderator and coolant. The liquid suspension flows into a chamber in which a critical amount of fissionable material is obtained. The fluid leaves the chamber and the heat of fission is extracted for power or other utilization. The improvement is in the support arrangement for a segrnented graphite core to permit dif ferential thermal expansion, effective sealing between main and blanket liquid metal flows, and avoidance of excessive stress development in the graphite segments. (AEC)

  7. A metallic fuel cycle concept from spent oxide fuel to metallic fuel

    SciTech Connect

    Fujita, Reiko; Kawashima, Masatoshi; Yamaoka, Mitsuaki; Arie, Kazuo; Koyama, Tadafumi

    2007-07-01

    A Metallic fuel cycle concept for Self-Consistent Nuclear Energy System (SCNES) has been proposed in a companion papers. The ultimate goal of the SCNES is to realize sustainable energy supply without endangering the environment and humans. For future transition period from LWR era to SCNES era, a new metallic fuel recycle concept from LWR spent fuel has been proposed in this paper. Combining the technology for electro-reduction of oxide fuels and zirconium recovery by electrorefining in molten salts in the nuclear recycling schemes, the amount of radioactive waste reduced in a proposed metallic fuel cycle concept. If the recovery ratio of zirconium metal from the spent zirconium waste is 95%, the cost estimation in zirconium recycle to the metallic fuel materials has been estimated to be less than 1/25. (authors)

  8. Status of Transuranic Bearing Metallic Fuel Development

    SciTech Connect

    Steve Hayes; Bruce Hilton; Heather MacLean; Debbie Utterbeck; Jon Carmack; Kemal Pasamehmetoglu

    2009-09-01

    This paper summarizes the status of the metallic fuel development under the Advanced Fuel Cycle Initiative (AFCI). The metallic fuel development program includes fuel fabrication, characterization, advanced cladding research, irradiation testing and post-irradiation examination (PIE). The focus of this paper is on the recent irradiation experiments conducted in the Advanced Test Reactor and some PIE results from these tests.

  9. Degradation of EBR-II driver fuel during wet storage

    SciTech Connect

    Pahl, R. G.

    2000-03-09

    Characterization data are reported for sodium bonded EBR-II reactor fuel which had been stored underwater in containers since the 1981--1982 timeframe. Ten stainless steel storage containers, which had leaked water during storage due to improper sealing, were retrieved from the ICPP-603 storage basin at the Idaho National Engineering and Environmental Laboratory (INEEL) in Idaho. In the container chosen for detailed destructive analysis, the stainless steel cladding on the uranium alloy fuel had ruptured and fuel oxide sludge filled the bottom of the container. Headspace gas sampling determined that greater than 99% hydrogen was present. Cesium 137, which had leached out of the fuel during the aqueous corrosion process, dominated the radionuclide source term of the water. The metallic sodium from the fuel element bond had reacted with the water, forming a concentrated caustic solution of NaOH.

  10. Irradiation behavior of metallic fast reactor fuels

    SciTech Connect

    Pahl, R.G.; Porter, D.L.; Crawford, D.C.; Walters, L.C.

    1991-01-01

    Metallic fuels were the first fuels chosen for liquid metal cooled fast reactors (LMR's). In the late 1960's world-wide interest turned toward ceramic LMR fuels before the full potential of metallic fuel was realized. However, during the 1970's the performance limitations of metallic fuel were resolved in order to achieve a high plant factor at the Argonne National Laboratory's Experimental Breeder Reactor II. The 1980's spawned renewed interest in metallic fuel when the Integral Fast Reactor (IFR) concept emerged at Argonne National Laboratory. A fuel performance demonstration program was put into place to obtain the data needed for the eventual licensing of metallic fuel. This paper will summarize the results of the irradiation program carried out since 1985.

  11. Metal-gas fuel cell

    SciTech Connect

    Struthers, R.C.

    1984-10-16

    A metal-gas fuel cell comprising an anode chamber filled with a base anolyte solution, a metallic anode plate immersed in the anolyte; an ion exchange chamber filled with a base ionolyte solution adjacent the anode chamber; a cationic membrane between the anode and ion exchange chambers separating the anolyte and ionolyte; a cathode plate adjacent the ion exchange chamber remote from the cationic membrane with one surface in contact with the ionolyte and another surface in contact with a cathode fuel gas. The cathode plate is a laminated structure including a layer of hydrophyllic material in contact with the ionolyte, a layer of gas permeable hydrophobic material in contact with the gas and a gas and liquid permeable current collector of inert material with catalytic surfaces within the layer of hydrophyllic material. The anode and cathode plates are connected with an external electric circuit which effects the flow of electrons from the anode plate to the cathode plate.

  12. Metal-fuel modeling for inherently safe reactor designs

    SciTech Connect

    Miles, K.J. Jr.

    1987-01-01

    Current development of breeder reactor systems has led to the renewed interest in metal fuels. These fuels have properties that enhance the inherent safety of the system, such as high thermal conductivity, compatibility with liquid sodium, and low fuel/cladding mechanical interaction. While metal-fuel irradiation behavior is well understood, there are some areas where more information is needed to fully understand the various safety-related phenomena, such as fuel/cladding chemical interaction, eutectic melting and penetration, and axial relocation of molten fuel prior to cladding breach. Because many of these phenomena can cause changes in the reactivity state of the system, their effects on whole-core normal, anticipated, and hypothetical accident scenarios need to be studied. The metal-fuel behavior model DEFORM-5 is being developed to provide the necessary phenomenological basis for these studies. The first stage in the DEFORM-5 development has been completed. Presently, DEFORM-5 calculates the cladding strain, life fraction, and eutectic penetration thinning for Types D9, HT9, or 316 steels. This first stage of DEFORM-5 has been used to analyze the TREAT M2, M3, and M4 transients with irradiated Experimental Breeder Reactor-II driver fuel. The paper shows the DEFORM-5 and experimental results for failure times for the test pins. The results provide confidence and validation of the DEFORM-5 modeling of the cladding behavior.

  13. Metal hydride fuel storage and method thereof

    DOEpatents

    Morse, Jeffrey D [Martinez, CA; Jankowski, Alan F [Livermore, CA; Yu, Conrad [Antioch, CA

    2009-05-05

    Disclosed herein is a metal hydride fuel storage cartridge having integrated resistive heaters that can be used in conjunction with fuel cells such as MEMS-based fuel cells. The cartridge is fabricated using micromachining methods and thin/thick film materials synthesis techniques.

  14. Metal hydride fuel storage and method thereof

    DOEpatents

    Morse, Jeffrey D.; Jankowski, Alan F.; Yu, Conrad

    2006-10-17

    Disclosed herein is a metal hydride fuel storage cartridge having integrated resistive heaters that can be used in conjunction with fuel cells such as MEMS-based fuel cells. The cartridge is fabricated using micromachining methods and thin/thick film materials synthesis techniques.

  15. Local fault tolerance of metal fuel

    SciTech Connect

    Tilbrook, R W; Pedersen, D R; Thompson, D H; Ragland, W A

    1986-02-01

    This IFR technical memorandum presents a review of the potential initiators of fuel failure in metal fuel and a preliminary evaluation of the consequences of failure and the potential for propagation within a fuel assembly. Lines of defense against initiation and propagation are identified and some discussed in detail including appropriate supportive conclusions from oxide fuel assessments. The ongoing supporting fuel element test program is described and areas requiring further analytical or experimental effort are identified. Based on the extensive experience in EBR-II with uranium-fissium fuel, and the differences between the properties of metallic and oxide fuel constitutents, superior local faults tolerance of ternary alloy fuel is anticipated. 34 refs.

  16. 33 CFR 183.538 - Metallic fuel line materials.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Metallic fuel line materials. 183... (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Fuel Systems Equipment Standards § 183.538 Metallic fuel line materials. Each metallic fuel line connecting the fuel tank with the fuel inlet connection...

  17. Relationship between blood metals and inflammation in taxi drivers.

    PubMed

    Brucker, Natália; Moro, Angela; Charão, Mariele; Bubols, Guilherme; Nascimento, Sabrina; Goethel, Gabriela; Barth, Anelise; Prohmann, Ana C; Rocha, Rafael; Moresco, Rafael; Sangoi, Manuela; Hausen, Bruna S; Saint'Pierre, Tatiana; Gioda, Adriana; Duarte, Marta; Castro, Iran; Saldiva, Paulo H; Garcia, Solange Cristina

    2015-04-15

    Cardiovascular disease is a cause of concern in public health worldwide, reinforcing the need for studies related to the identification of potential agents that contribute to the inflammation process and atherosclerosis. This study aimed to evaluate whether metals are associated with inflammatory and kidney damage and could contribute to the atherosclerosis process. Blood metals, inflammatory markers, homocysteine, antioxidants and renal markers were measured in 42 taxi drivers and 27 controls (non-occupationally exposed). Taxi drivers had increased Hg, As, Pb and Cd levels, however Cu and Zn levels were decreased compared to controls (p<0.05). Hg, As and Pb levels were positively associated with pro-inflammatory cytokines, nitric oxide and negatively associated with glutathione peroxidase. Moreover, Hg, As and Pb presented positive associations with homocysteine, an independent risk factor for atherosclerosis. Regarding markers of kidney function, N-acetyl-beta-d-glucosaminidase levels were increased in taxi drivers and correlated to inflammation markers. Hg levels were found above the recommended limits in taxi drivers and both Hg and As levels showed associations with inflammatory process, oxidative status and homocysteine. Thus, chemical substances as Hg and As can be considered as additional contributors to the development of cardiovascular diseases. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. Microstructural Characterization of Cast Metallic Transmutation Fuels

    SciTech Connect

    J. I. Cole; D. D. Keiser; J. R. Kennedy

    2007-09-01

    As part of the Global Nuclear Energy Partnership (GNEP) and the Advanced Fuel Cycle Initiative (AFCI), the US Department of Energy (DOE) is participating in an international collaboration to irradiate prototypic actinide-bearing transmutation fuels in the French Phenix fast reactor (FUTURIX-FTA experiment). The INL has contributed to this experiment by fabricating and characterizing two compositions of metallic fuel; a non-fertile 48Pu-12Am-40Zr fuel and a low-fertile 35U-29Pu-4Am-2Np-30Zr fuel for insertion into the reactor. This paper highlights results of the microstructural analysis of these cast fuels, which were reasonably homogeneous in nature, but had several distinct phase constituents. Spatial variations in composition appeared to be more pronounced in the low-fertile fuel when compared to the non-fertile fuel.

  19. Development of Metallic Fuels for Actinide Transmutation

    SciTech Connect

    Hayes, Steven Lowe; Fielding, Randall Sidney; Benson, Michael Timothy; Chichester, Heather Jean MacLean; Carmack, William Jonathan

    2015-09-01

    Research and development activities on metallic fuels are focused on their potential use for actinide transmutation in future sodium fast reactors. As part of this application, there is also a need for a near zero-loss fabrication process and a desire to demonstrate a multifold increase in burnup potential. The incorporation of Am and Np into the traditional U-20Pu-10Zr metallic fuel alloy was demonstrated in the US during the Integral Fast Reactor Program of the 1980’s and early 1990’s. However, the conventional counter gravity injection casting method performed under vacuum, previously used to fabricate these metallic fuel alloys, was not optimized for mitigating loss of the volatile Am constituent in the casting charge; as a result, approximately 40% of the Am casting charge failed to be incorporated into the as-cast fuel alloys. Fabrication development efforts of the past few years have pursued an optimized bottom-pour casting method to increase utilization of the melted charge to near 100%, and a differential pressure casting approach, performed under an argon overpressure, has been demonstrated to result in essentially no loss of Am due to volatilization during fabrication. In short, a path toward zero-loss fabrication of metallic fuels including minor actinides has been shown to be feasible. Irradiation testing of advanced metallic fuel alloys in the Advanced Test Reactor (ATR) has been underway since 2003. Testing in the ATR is performed inside of cadmium-shrouded positions to remove >99% of the thermal flux incident on the test fuels, resulting in an epi-thermal driven fuel test that is free from gross flux depression and producing an essentially prototypic radial temperature profile inside the fuel rodlets. To date, three irradiation test series (AFC-1,2,3) have been completed. Over 20 different metallic fuel alloys have been tested to burnups as high as 30% with constituent compositions of Pu up to 30%, Am up to 12%, Np up to 10%, and Zr between 10

  20. Preparing oxidizer coated metal fuel particles

    NASA Technical Reports Server (NTRS)

    Shafer, J. I.; Simmons, G. M. (Inventor)

    1974-01-01

    A solid propellant composition of improved efficiency is described which includes an oxidizer containing ammonium perchlorate, and a powered metal fuel, preferably aluminum or beryllium, in the form of a composite. The metal fuel is contained in the crystalline lattice framework of the oxidizer, as well as within the oxidizer particles, and is disposed in the interstices between the oxidizer particles of the composition. The propellant composition is produced by a process comprising the crystallization of ammonium perchlorate in water, in the presence of finely divided aluminum or beryllium. A suitable binder is incorporated in the propellant composition to bind the individual particles of metal with the particles of oxidizer containing occluded metal.

  1. 33 CFR 183.562 - Metallic fuel lines.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... fuel lines. (a) Each metallic fuel line that is mounted to the boat structure must be connected to the engine by a flexible fuel line. (b) Each metallic fuel line must be attached to the boat's structure... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Metallic fuel lines....

  2. 33 CFR 183.562 - Metallic fuel lines.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... fuel lines. (a) Each metallic fuel line that is mounted to the boat structure must be connected to the engine by a flexible fuel line. (b) Each metallic fuel line must be attached to the boat's structure... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Metallic fuel lines....

  3. 33 CFR 183.562 - Metallic fuel lines.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... fuel lines. (a) Each metallic fuel line that is mounted to the boat structure must be connected to the engine by a flexible fuel line. (b) Each metallic fuel line must be attached to the boat's structure... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Metallic fuel lines....

  4. 33 CFR 183.562 - Metallic fuel lines.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... fuel lines. (a) Each metallic fuel line that is mounted to the boat structure must be connected to the engine by a flexible fuel line. (b) Each metallic fuel line must be attached to the boat's structure... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Metallic fuel lines....

  5. Metal fuel manufacturing and irradiation performance

    SciTech Connect

    Pedersen, D.R.; Walters, L.C.

    1992-06-01

    The advances in metal fuel by the Integral Fast Reactor Program at Argonne National Laboratory are the subject of this paper. The Integral Fast Reactor (IFR) is an advanced liquid-metal-cooled reactor concept being developed at Argonne National Laboratory. The advances stressed in the paper include fuel irradiation performance, and improved passive safety. The goals and the safety philosophy of the Integral Fast Reactor Program are stressed.

  6. Metal fuel manufacturing and irradiation performance

    SciTech Connect

    Pedersen, D.R.; Walters, L.C.

    1992-01-01

    The advances in metal fuel by the Integral Fast Reactor Program at Argonne National Laboratory are the subject of this paper. The Integral Fast Reactor (IFR) is an advanced liquid-metal-cooled reactor concept being developed at Argonne National Laboratory. The advances stressed in the paper include fuel irradiation performance, and improved passive safety. The goals and the safety philosophy of the Integral Fast Reactor Program are stressed.

  7. PLUTONIUM METALLIC FUELS FOR FAST REACTORS

    SciTech Connect

    STAN, MARIUS; HECKER, SIEGFRIED S.

    2007-02-07

    Early interest in metallic plutonium fuels for fast reactors led to much research on plutonium alloy systems including binary solid solutions with the addition of aluminum, gallium, or zirconium and low-melting eutectic alloys with iron and nickel or cobalt. There was also interest in ternaries of these elements with plutonium and cerium. The solid solution and eutectic alloys have most unusual properties, including negative thermal expansion in some solid-solution alloys and the highest viscosity known for liquid metals in the Pu-Fe system. Although metallic fuels have many potential advantages over ceramic fuels, the early attempts were unsuccessful because these fuels suffered from high swelling rates during burn up and high smearing densities. The liquid metal fuels experienced excessive corrosion. Subsequent work on higher-melting U-PuZr metallic fuels was much more promising. In light of the recent rebirth of interest in fast reactors, we review some of the key properties of the early fuels and discuss the challenges presented by the ternary alloys.

  8. Performance analysis of a mixed nitride fuel system for an advanced liquid metal reactor

    SciTech Connect

    Lyon, W.F.; Baker, R.B.; Leggett, R.D.

    1990-11-01

    The conceptual development and analysis of a proposed mixed nitride driver and blanket fuel system for a prototypic advanced liquid metal reactor design has been performed. As a first step, an intensive literature survey was completed on the development and testing of nitride fuel systems. Based on the results of this survey, prototypic mixed nitride fuel and blanket pins were designed and analyzed using the SIEX computer code. The analysis predicted that the nitride fuel consistently operated at peak temperatures and cladding strain levels that compared quite favorably with competing fuel designs. These results, along with data available in the literature on nitride fuel performance, indicate that a nitride fuel system should offer enhanced capabilities for advanced liquid metal reactors. 13 refs., 10 figs., 2 tabs.

  9. 33 CFR 183.562 - Metallic fuel lines.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Metallic fuel lines. 183.562...) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Fuel Systems Manufacturer Requirements § 183.562 Metallic fuel lines. (a) Each metallic fuel line that is mounted to the boat structure must be connected to...

  10. Refueling Behavior of Flexible Fuel Vehicle Drivers in the Federal Fleet

    SciTech Connect

    Daley, R.; Nangle, J.; Boeckman, G.; Miller, M.

    2014-05-01

    Federal fleets are a frequent subject of legislative and executive efforts to lead a national transition to alternative fuels and advanced vehicle technologies. Section 701 of the Energy Policy Act of 2005 requires that all dual-fueled alternative fuel vehicles in the federal fleet be operated on alternative fuel 100% of the time when they have access to it. However, in Fiscal Year (FY) 2012, drivers of federal flex fuel vehicles (FFV) leased through the General Services Administration refueled with E85 24% of the time when it was available--falling well short of the mandate. The U.S. Department of Energy's National Renewable Energy Laboratory completed a 2-year Laboratory Directed Research and Development project to identify the factors that influence the refueling behavior of federal FFV drivers. The project began with two primary hypotheses. First, information scarcity increases the tendency to miss opportunities to purchase E85. Second, even with perfect information, there are limits to how far drivers will go out of their way to purchase E85. This paper discusses the results of the project, which included a June 2012 survey of federal fleet drivers and an empirical analysis of actual refueling behavior from FY 2009 to 2012. This research will aid in the design and implementation of intervention programs aimed at increasing alternative fuel use and reducing petroleum consumption.

  11. Volatile species retention during metallic fuel casting

    NASA Astrophysics Data System (ADS)

    Fielding, Randall S.; Porter, Douglas L.

    2013-10-01

    Metallic nuclear fuels are candidate transmutation fuel forms for advanced fuel cycles. Through the operation of the Experimental Breeder Reactor II metallic nuclear fuels have been shown to be robust and easily manufactured. However, concerns have been raised concerning loss of americium during the casting process because of its high vapor pressure. In order to address these concerns a gaseous diffusion model was developed and a series of experiments using both manganese and samarium as surrogates for americium were conducted. The modeling results showed that volatility losses can be controlled to essentially no losses with a modest overpressure. Experimental results also showed volatile species retention down to no detectable losses through overpressure, and although the loss values varied from the model results the same trend was seen. Based on these results it is very probable that americium losses through volatility can be controlled to no detectable losses through application of a modest overpressure during casting.

  12. Volatile Species Retention During Metallic Fuel Casting

    SciTech Connect

    Randall S. Fielding; Douglas L. Proter

    2013-10-01

    Metallic nuclear fuels are candidate transmutation fuel forms for advanced fuel cycles. Through the operation of the Experimental Breeder Reactor II metallic nuclear fuels have been shown to be robust and easily manufactured. However, concerns have been raised concerning loss of americium during the casting process because of its high vapor pressure. In order to address these concerns a gaseous diffusion model was developed and a series of experiments using both manganese and samarium as surrogates for americium were conducted. The modeling results showed that volatility losses can be controlled to essentially no losses with a modest overpressure. Experimental results also showed volatile species retention down to no detectable losses through overpressure, although the loss values varied from the model results the same trend was seen. Bases on these results it is very probably that americium losses through volatility can be controlled to no detectable losses through application of a modest overpressure during casting.

  13. Cladding failure margins for metallic fuel in the integral fast reactor

    SciTech Connect

    Bauer, T.H.; Fenske, G.R.; Kramer, J.M.

    1987-01-01

    The reference fuel for Integral Fast Reactor (IFR) is a ternary U-Pu-Zr alloy with a low swelling austenitic or ferritic stainless steel cladding. It is known that low melting point eutectics may form in such metallic fuel-cladding systems which could contribute to cladding failure under accident conditions. This paper will present recent measurements of cladding eutectic penetration rates for the ternary IFR alloy and will compare these results with earlier eutectic penetration data for other fuel and cladding materials. A method for calculating failure of metallic fuel pins is developed by combining cladding deformation equations with a large strain analysis where the hoop stress is calculated using the instantaneous wall thickness as determined from correlations of the eutectic penetration-rate data. This method is applied to analyze the results of in-reactor and out-of-reactor fuel pin failure tests on uranium-fissium alloy EBR-II Mark-II driver fuel.

  14. Fabrication of U-10 wt.%Zr Metallic Fuel Rodlets for Irradiation Test in BOR-60 Fast Reactor

    DOE PAGES

    Kim, Ki-Hwan; Kim, Jong-Hwan; Oh, Seok-Jin; ...

    2016-01-01

    The fabrication technology for metallic fuel has been developed to produce the driver fuel in a PGSFR in Korea since 2007. In order to evaluate the irradiation integrity and validate the in-reactor of the starting metallic fuel with FMS cladding for the loading of the metallic fuel, U-10 wt.%Zr fuel rodlets were fabricated and evaluated for a verification of the starting driver fuel through an irradiation test in the BOR-60 fast reactor. The injection casting method was applied to U-10 wt.%Zr fuel slugs with a diameter of 5.5 mm. Consequently, fuel slugs per melting batch without casting defects were fabricated through the developmentmore » of advanced casting technology and evaluation tests. The optimal GTAW welding conditions were also established through a number of experiments. In addition, a qualification test was carried out to prove the weld quality of the end plug welding of the metallic fuel rodlets. The wire wrapping of metallic fuel rodlets was successfully accomplished for the irradiation test. Thus, PGSFR fuel rodlets have been soundly fabricated for the irradiation test in a BOR-60 fast reactor.« less

  15. Metal-deactivating additives for liquid fuels

    SciTech Connect

    Boneva, M.I.; Ivanov, S.K.; Kalitchin, Z.D.; Tanielyan, S.K.; Terebenina, A.; Todorova, O.I.

    1995-05-01

    The metal-deactivating and the antioxidant properties of 1-phenyl-3-methylpyrazolone-5 derivatives have been investigated both in the model reaction of low temperature oxidation of ethylbenzene and in gasoline oxidation. The study of the ability of these derivatives to reduce the catalytic effect of copper naphthenate demonstrates that they are promising as metal deactivating additives for light fuels. Some of the pyrazolone compounds appear to be of special interest for the long-term storage of liquid fuels due to their action as multifunctional inhibitors.

  16. Personal exposures to airborne metals in London taxi drivers and office workers in 1995 and 1996.

    PubMed

    Pfeifer, G D; Harrison, R M; Lynam, D R

    1999-09-01

    In 1995, a petroleum marketer introduced a diesel fuel additive in the UK containing Mn as MMT (methylcyclopentadienyl manganese tricarbonyl). A small study of personal exposures to airborne Mn in London was conducted before and after introduction of the additive to identify any major impact of the additive on exposures. In 1995, personal exposures to Mn were measured in two groups, taxi drivers and office workers (10 subjects per group) for two consecutive 7-day periods. A similar study was carried out in 1996 to determine if exposures had changed. Samples were also analyzed for Ca, Al, Mg and Pb. In 1996, exposures to aerosol mass as total suspended particulates (TSP) and PM2.5 were measured in addition to the metals. Manganese exposures in this cohort did not increase as a result of introduction of the additive. However, a significant source of Mn exposure was discovered during the conduct of these tests. The mean exposure to Mn was higher among the office workers in both years than that of the taxi drivers. This was due to the fact that approximately half of the office workers commuted via the underground railway system where airborne dust and metal concentrations are significantly elevated over those in the general environment. Similar results have been noted in other cities having underground rail systems. Exposure to Mn, Pb, Ca, and Mg were not significantly different between the 2 years. Taxi drivers had higher exposures than office workers to Mg and Pb in both years. Commuting via the underground also had a significant impact on exposures to TSP, PM2.5, Al, and Ca, but had little effect on exposures to Mg. The aerosol in the underground was particularly enriched in Mn, approximately 10-fold, when compared to the aerosol in the general environment. There are several possible sources for this Mn, including mechanical wear of the steel wheels on the steel rais, vaporization of metal from sparking of the third rail, or brake wear.

  17. Electrolytic recovery of reactor metal fuel

    DOEpatents

    Miller, W.E.; Tomczuk, Z.

    1994-09-20

    A new electrolytic process and apparatus are provided using sodium, cerium or a similar metal in alloy or within a sodium beta or beta[double prime]-alumina sodium ion conductor to electrolytically displace each of the spent fuel metals except for cesium and strontium on a selective basis from the electrolyte to an inert metal cathode. Each of the metals can be deposited separately. An electrolytic transfer of spent fuel into the electrolyte includes a sodium or cerium salt in the electrolyte with sodium or cerium alloy being deposited on the cathode during the transfer of the metals from the spent fuel. The cathode with the deposit of sodium or cerium alloy is then shunted to an anode and the reverse transfer is carried out on a selective basis with each metal being deposited separately at the cathode. The result is that the sodium or cerium needed for the process is regenerated in the first step and no additional source of these reactants is required. 2 figs.

  18. Electrolytic recovery of reactor metal fuel

    DOEpatents

    Miller, William E.; Tomczuk, Zygmunt

    1994-01-01

    A new electrolytic process and apparatus are provided using sodium, cerium or a similar metal in alloy or within a sodium beta or beta"-alumina sodium ion conductor to electrolytically displace each of the spent fuel metals except for cesium and strontium on a selective basis from the electrolyte to an inert metal cathode. Each of the metals can be deposited separately. An electrolytic transfer of spent fuel into the electrolyte includes a sodium or cerium salt in the electrolyte with sodium or cerium alloy being deposited on the cathode during the transfer of the metals from the spent fuel. The cathode with the deposit of sodium or cerium alloy is then chanted to an anode and the reverse transfer is carried out on a selective basis with each metal being deposited separately at the cathode. The result is that the sodium or cerium needed for the process is regenerated in the first step and no additional source of these reactants is required.

  19. Electrolytic recovery of reactor metal fuel

    DOEpatents

    Miller, W.E.; Tomczuk, Z.

    1993-02-03

    This invention is comprised of a new electrolytic process and apparatus using sodium, cerium or a similar metal in an alloy or within a sodium beta or beta-alumina sodium ion conductor to electrolytically displace each of the spent fuel metals except for Cesium and strontium on a selective basis from the electrolyte to an inert metal cathode. Each of the metals can be deposited separately. An electrolytic transfer of spent fuel into the electrolyte includes a sodium or cerium salt in the electrolyte with sodium or cerium alloy being deposited on the cathode during the transfer of the metals from the spent fuel. The cathode with the deposit of sodium or cerium alloy is then changed to an anode and the reverse transfer is carried out on a selective basis with each metal being deposited separately at the cathode. The result is that the sodium or cerium needed for the process is regenerated in the first step and no additional source of these reactants is required.

  20. Fuel cells and the theory of metals.

    NASA Technical Reports Server (NTRS)

    Bocciarelli, C. V.

    1972-01-01

    Metal theory is used to study the role of metal catalysts in electrocatalysis, with particular reference to alkaline hydrogen-oxygen fuel cells. Use is made of a simple model, analogous to that used to interpret field emission in vacuum. Theoretical values for all the quantities in the Tafel equation are obtained in terms of bulk properties of the metal catalysts (such as free electron densities and Fermi level). The reasons why some processes are reversible (H-electrodes) and some irreversible (O-electrodes) are identified. Selection rules for desirable properties of catalytic materials are established.

  1. Fuel cells and the theory of metals.

    NASA Technical Reports Server (NTRS)

    Bocciarelli, C. V.

    1972-01-01

    Metal theory is used to study the role of metal catalysts in electrocatalysis, with particular reference to alkaline hydrogen-oxygen fuel cells. Use is made of a simple model, analogous to that used to interpret field emission in vacuum. Theoretical values for all the quantities in the Tafel equation are obtained in terms of bulk properties of the metal catalysts (such as free electron densities and Fermi level). The reasons why some processes are reversible (H-electrodes) and some irreversible (O-electrodes) are identified. Selection rules for desirable properties of catalytic materials are established.

  2. Electrochemical Dissolution of Spent EBR-II Driver Fuel in Molten Salt Electrolyte

    SciTech Connect

    S. X. Li; D. Vaden; R. W. Benedict; K. M. Goff

    2006-06-01

    Pyrochemical processing is a promising technology for closing the nuclear fuel cycle for next generation nuclear reactors. At Idaho National Laboratory (INL), such a pyrochemical process has been implemented for the treatment of spent fuel from the Experimental Breeder Reactor (EBR-II). A successful demonstration of the technology was performed from 1996 to 1999 for the Department of Energy (DOE). Since 2002, processing of the spent fuel and associated research and development activities have been carried out under DOE’s Advanced Fuel Cycle Initiative (AFCI) program. Electrorefining is considered to be the signature or central technology for pyrochemical processing. This paper summarizes recent experience and results in electrorefining, specifically focusing on electrochemical dissolution of spent EBR-II driver fuel in the Mark-IV (Mk-IV) electrorefiner (ER).

  3. POWER GENERATION FROM LIQUID METAL NUCLEAR FUEL

    DOEpatents

    Dwyer, O.E.

    1958-12-23

    A nuclear reactor system is described wherein the reactor is the type using a liquid metal fuel, such as a dispersion of fissile material in bismuth. The reactor is designed ln the form of a closed loop having a core sectlon and heat exchanger sections. The liquid fuel is clrculated through the loop undergoing flssion in the core section to produce heat energy and transferrlng this heat energy to secondary fluids in the heat exchanger sections. The fission in the core may be produced by a separate neutron source or by a selfsustained chain reaction of the liquid fuel present in the core section. Additional auxiliary heat exchangers are used in the system to convert water into steam which drives a turbine.

  4. Irradiation performance of full-length metallic IFR fuels

    SciTech Connect

    Tsai, H.; Neimark, L.A.

    1992-07-01

    An assembly irradiation of 169 full-length U-Pu-Zr metallic fuel pins was successfully completed in FFTF to a goal burnup of 10 at.%. All test fuel pins maintained their cladding integrity during the irradiation. Postirradiation examination showed minimal fuel/cladding mechanical interaction and excellent stability of the fuel column. Fission-gas release was normal and consistent with the existing data base from irradiation testing of shorter metallic fuel pins in EBR-II.

  5. Self-fueled biomimetic liquid metal mollusk.

    PubMed

    Zhang, Jie; Yao, Youyou; Sheng, Lei; Liu, Jing

    2015-04-24

    A liquid metal motor that can "eat" aluminum food and then move spontaneously and swiftly in various solution configurations and structured channels for more than 1 h is discovered. Such a biomimetic mollusk is highly shape self-adaptive by closely conforming to the geometrical space it voyages in. The first ever self-fueled pump is illustrated as one of its typical practical utilizations.

  6. Precious Metal Recovery from Fuel Cell MEA's

    SciTech Connect

    Shore, Lawrence

    2004-04-27

    In 2003, Engelhard Corporation received a DOE award to develop a cost-effective, environmentally friendly approach to recover Pt from fuel cell membrane electrode assemblies (MEA’s). The most important precious metal used in fuel cells is platinum, but ruthenium is also added to the anode electrocatalyst if CO is present in the hydrogen stream. As part of the project, a large number of measurements of Pt and Ru need to be made. A low-cost approach to measuring Pt is using the industry standard spectrophotometric measurement of Pt complexed with stannous chloride. The interference of Ru can be eliminated by reading the Pt absorbance at 450 nm. Spectrophotometric methods for measuring Ru, while reported in the literature, are not as robust. These slides will discuss the options for measuring Pt and Ru using the method of UV-VIS spectrophotometry

  7. Characterization of corroded metallic uranium fuel plates

    NASA Astrophysics Data System (ADS)

    Totemeier, T. C.; Pahl, R. G.; Hayes, S. L.; Frank, S. M.

    1998-08-01

    A brief background on the history of the corrosion of uranium metal fuel plates from the Zero Power Physics Reactor (ZPPR) and the findings of a recent characterization of the corrosion are presented. The characterization encompassed visual examination, metallography, scanning electron microscopy, and X-ray diffraction. Corrosion of the plates has been observed essentially since their manufacture. The corrosion was found to have both general and localized forms. A black powder corrosion product associated with areas of localized attack was determined to be UH 3, while the remainder of the corrosion product was UO 2+ x.

  8. The dynamics and drivers of fuel and fire in the Portuguese public forest.

    PubMed

    Fernandes, Paulo M; Loureiro, Carlos; Guiomar, Nuno; Pezzatti, Gianni B; Manso, Filipa T; Lopes, Luís

    2014-12-15

    The assumption that increased wildfire incidence in the Mediterranean Basin during the last decades is an outcome of changes in land use warrants an objective analysis. In this study we examine how annual area burned (BA) in the Portuguese public forest varied in relation to environmental and human-influenced drivers during the 1943-2011 period. Fire behaviour models were used to describe fuel hazard considering biomass removal, cover type changes, area burned, post-disturbance fuel accumulation, forest age-classes distribution and fuel connectivity. Biomass removal decreased rapidly beyond the 1940s, which, along with afforestation, increased fuel hazard until the 1980s; a subsequent decline was caused by increased fire activity. Change point analysis indicates upward shifts in BA in 1952 and in 1973, both corresponding to six-fold increases. Fire weather (expressed by the 90th percentile of the Canadian FWI during summer) increased over the study period, accounting for 18 and 36% of log(BA) variation before 1974 and after 1973, respectively. Regression modelling indicates that BA responds positively to fire weather, fuel hazard and number of fires in descending order of importance; pre-summer and 2-year lagged precipitation respectively decrease and increase BA, but the effects are minor and non-significant when both variables are included in the model. Land use conflicts (expressed through more fires) played a role, but it was afforestation and agricultural abandonment that supported the fire regime shifts, explaining weather-drought as the current major driver of BA as well. We conclude that bottom-up factors, i.e. human-induced changes in landscape flammability and ignition density, can enhance or override the influence of weather-drought on the fire regime in Mediterranean humid regions. A more relevant role of fuel control in fire management policies and practices is warranted by our findings. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Fuel management studies of small metal and oxide LMR's

    SciTech Connect

    Khalil, H.; Fujita, E.K.; Yang, S.; Orechwa, Y.

    1986-01-01

    Fuel-cycle analyses performed at Argonne National Laboratory to evaluate and compare the neutronic performance characteristics of small oxide- and metal-fueled LMR's are described. Specific consideration is given to those analyses concerned with optimization of core and blanket configurations, selection of fuel residence time and refueling interval, determination of control rod worths and requirements, development of in-core fuel management strategy, and evaluation of performance characteristics both for startup cycles and for the equilibrium state reached via repeated recycle of discharged fuel. Differences in the computed performance parameters of oxide and metal cores, arising from basic differences in their neutronic characteristics, are identified and discussed. Metal-fueled cores are shown to offer some important performance advantages over oxide cores for small LMR's because of their harder spectrum, superior neutron economy, and greater breeding capacity. These advantages include smaller fissile and heavy metal loadings, lower control-system requirements, and greater adaptability to changes in fuel management scenarios.

  10. Colloids generation from metallic uranium fuel

    SciTech Connect

    Metz, C.; Fortner, J.; Goldberg, M.; Shelton-Davis, C.

    2000-07-20

    The possibility of colloid generation from spent fuel in an unsaturated environment has significant implications for storage of these fuels in the proposed repository at Yucca Mountain. Because colloids can act as a transport medium for sparingly soluble radionuclides, it might be possible for colloid-associated radionuclides to migrate large distances underground and present a human health concern. This study examines the nature of colloidal materials produced during corrosion of metallic uranium fuel in simulated groundwater at elevated temperature in an unsaturated environment. Colloidal analyses of the leachates from these corrosion tests were performed using dynamic light scattering and transmission electron microscopy. Results from both techniques indicate a bimodal distribution of small discrete particles and aggregates of the small particles. The average diameters of the small, discrete colloids are {approximately}3--12 nm, and the large aggregates have average diameters of {approximately}100--200 nm. X-ray diffraction of the solids from these tests indicates a mineral composition of uranium oxide or uranium oxy-hydroxide.

  11. Advances in Metallic Fuels for High Burnup and Actinide Transmutation

    SciTech Connect

    Hayes, S. L.; Harp, J. M.; Chichester, H. J. M.; Fielding, R. S.; Mariani, R. D.; Carmack, W. J.

    2016-10-01

    Research and development activities on metallic fuels in the US are focused on their potential use for actinide transmutation in future sodium fast reactors. As part of this application, there is a desire to demonstrate a multifold increase in burnup potential. A number of metallic fuel design innovations are under investigation with a view toward significantly increasing the burnup potential of metallic fuels, since higher discharge burnups equate to lower potential actinide losses during recycle. Promising innovations under investigation include: 1) lowering the fuel smeared density in order to accommodate the additional swelling expected as burnups increase, 2) utilizing an annular fuel geometry for better geometrical stability at low smeared densities, as well as the potential to eliminate the need for a sodium bond, and 3) minor alloy additions to immobilize lanthanide fission products inside the metallic fuel matrix and prevent their transport to the cladding resulting in fuel-cladding chemical interaction. This paper presents results from these efforts to advance metallic fuel technology in support of high burnup and actinide transmutation objectives. Highlights include examples of fabrication of low smeared density annular metallic fuels, experiments to identify alloy additions effective in immobilizing lanthanide fission products, and early postirradiation examinations of annular metallic fuels having low smeared densities and palladium additions for fission product immobilization.

  12. Fabrication and Preliminary Evaluation of Metal Matrix Microencapsulated Fuels

    SciTech Connect

    Terrani, Kurt A; Kiggans, Jim; Snead, Lance Lewis

    2012-01-01

    The metal matrix microencapsulated (M3) fuel concept for light water reactors (LWRs), consisting of coated fuel particles dispersed in a zirconium metal matrix, is introduced. Fabrication of M3 fuels by hot pressing, hot isostatic pressing, or extrusion methodologies has been demonstrated over the temperature range 800-1050 C. Various types of coated fuel particles with outermost layers of pyrocarbon, SiC, ZrC, and TiN have been incorporated into the zirconium metal matrix. Mechanical particle-particle and chemical particle-matrix interactions have been observed during the preliminary characterization of as-fabricated M3 specimens. Irradiation of three M3 rodlets with surrogate coated fuel particles was carried out at mean rod temperature of 400 C to 4.6 dpa in the zirconium metal matrix. Due to absence of texture in the metal matrix no irradiation growth strain (<0.09%) was detected during the post-irradiation examination.

  13. Viscosity Meaurement Technique for Metal Fuels

    SciTech Connect

    Ban, Heng; Kennedy, Rory

    2015-02-09

    Metallic fuels have exceptional transient behavior, excellent thermal conductivity, and a more straightforward reprocessing path, which does not separate out pure plutonium from the process stream. Fabrication of fuel containing minor actinides and rare earth (RE) elements for irradiation tests, for instance, U-20Pu-3Am-2Np-1.0RE-15Zr samples at the Idaho National Laboratory, is generally done by melt casting in an inert atmosphere. For the design of a casting system and further scale up development, computational modeling of the casting process is needed to provide information on melt flow and solidification for process optimization. Therefore, there is a need for melt viscosity data, the most important melt property that controls the melt flow. The goal of the project was to develop a measurement technique that uses fully sealed melt sample with no Americium vapor loss to determine the viscosity of metallic melts and at temperatures relevant to the casting process. The specific objectives of the project were to: develop mathematical models to establish the principle of the measurement method, design and build a viscosity measurement prototype system based on the established principle, and calibrate the system and quantify the uncertainty range. The result of the project indicates that the oscillation cup technique is applicable for melt viscosity measurement. Detailed mathematical models of innovative sample ampoule designs were developed to not only determine melt viscosity, but also melt density under certain designs. Measurement uncertainties were analyzed and quantified. The result of this project can be used as the initial step toward the eventual goal of establishing a viscosity measurement system for radioactive melts.

  14. Nanotechnology Investigated for Future Gelled and Metallized Gelled Fuels

    NASA Technical Reports Server (NTRS)

    Palaszewski, Bryan A.

    2003-01-01

    The objective of this research is to create combustion data for gelled and metallized gelled fuels using unique nanometer-sized gellant particles and/or nanometer-sized aluminum particles. Researchers at the NASA Glenn Research Center are formulating the fuels for both gas turbine and pulsed detonation engines. We intend to demonstrate metallized gelled fuel ignition characteristics for pulse detonation engines with JP/aluminum fuel and for gas turbine engines with gelled JP, propane, and methane fuel. The fuels to be created are revolutionary as they will deliver the highest theoretically maximum performance of gelled and metallized gelled fuels. Past combustion work has used micrometer-sized particles, which have limited the combustion performance of gelled and metallized gelled fuels. The new fuel used nanometer-sized aluminum oxide particles, which reduce the losses due to mismatch in the gas and solid phases in the exhaust. Gelled fuels provide higher density, added safety, reduced fuel slosh, reduced leakage, and increased exhaust velocity. Altogether, these benefits reduce the overall size and mass of the vehicle, increasing its flexibility.

  15. Fleet Conversion in Local Government: Determinants of Driver Fuel Choice for Bi-Fuel Vehicles

    ERIC Educational Resources Information Center

    Johns, Kimberly D.; Khovanova, Kseniya M.; Welch, Eric W.

    2009-01-01

    This study evaluates the conversion of one local government's fleet from gasoline to bi-fuel E-85, compressed natural gas, and liquid propane gas powered vehicles at the midpoint of a 10-year conversion plan. This study employs a behavioral model based on the theory of reasoned action to explore factors that influence an individual's perceived and…

  16. Fleet Conversion in Local Government: Determinants of Driver Fuel Choice for Bi-Fuel Vehicles

    ERIC Educational Resources Information Center

    Johns, Kimberly D.; Khovanova, Kseniya M.; Welch, Eric W.

    2009-01-01

    This study evaluates the conversion of one local government's fleet from gasoline to bi-fuel E-85, compressed natural gas, and liquid propane gas powered vehicles at the midpoint of a 10-year conversion plan. This study employs a behavioral model based on the theory of reasoned action to explore factors that influence an individual's perceived and…

  17. Constituent Redistribution in U-Zr Metallic Fuel Using the Advanced Fuel Performance Code BISON

    SciTech Connect

    Galloway, Jack D.; Unal, Cetin; Matthews, Christopher

    2016-09-30

    Previous work done by Galloway, et. al. on EBR-II ternary (U-Pu-Zr) fuel constituent redistribution yielded accurate simulation data for the limited data sets of Zr redistribution. The data sets included EPMA scans of two different irradiated rods. First, T179, which was irradiated to 1.9 at% burnup, was analyzed. Second, DP16, which was irradiated to 11 at% burnup, was analyzed. One set of parameters that most accurately represented the zirconium profiles for both experiments was determined. Since the binary fuel (U-Zr) has previously been used as the driver fuel for sodium fast reactors (SFR) as well as being the likely driver fuel if a new SFR is constructed, this same process has been initiated on the binary fuel form. From limited binary EPMA scans as well as other fuel characterization techniques, it has been observed that zirconium redistribution also occurs in the binary fuel, albeit at a reduced rate compared to observation in the ternary fuel, as noted by Kim et. al. While the rate of redistribution has been observed to be slower, numerous metallographs of U-Zr fuel show distinct zone formations.

  18. Integral fast reactor concept. [Pool type; metal fuel; integral fuel cycle

    SciTech Connect

    Chang, Y.I.; Marchaterre, J.F.; Sevy, R.H.

    1984-01-01

    Key features of the IFR consist of a pool-type plant arrangement, a metal fuel-based core design, and an integral fuel cycle with colocated fuel cycle facility. Both the basic concept and the technology base have been demonstrated through actual integral cycle operation in EBR-II. This paper discusses the inherent safety characteristics of the IFR concept. (DLC)

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

    SciTech Connect

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

    1989-03-01

    This study summarizes the neutronic and fuel cycle analysis performed at Argonne National Laboratory for an oxide and a metal fueled 3500 MWth LMR. The oxide and metal core designs were developed to meet reactor performance specifications that are constrained by requirements for core loading interchangeability and for small burnup reactivity swing. Differences in the computed performance parameters of the oxide and metal cores, arising from basic differences in their neutronic characteristics, were 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., 25 figs.

  20. In situ observation of axial irradiation growth in liquid-metal reactor metal fuel

    SciTech Connect

    Cramer, E.R.; Pitner, A.L.

    1989-01-01

    Effects of the rapid early-in-life expansion of metal fuel were measured in an irradiation experiment in the Fast Flux Test Facility (FFTF). This important performance/design information was obtainable through the unique combination of a dimensionally stable FFTF oxide core and the calibrated proximity instrumentation associated with the test. These results delineate the time dependence of metal-fuel swelling and provide quantitative estimates of the magnitude of axial fuel swelling in full-length metal-fuel assemblies. Final posttest examination results will define actual fuel column growth levels.

  1. Metallic fuels: The EBR-II legacy and recent advances

    SciTech Connect

    Douglas L. Porter; Steven L. Hayes; J. Rory Kennedy

    2012-09-01

    Experimental Breeder Reactor – II (EBR-II) metallic fuel was qualified for high burnup to approximately 10 atomic per cent. Subsequently, the electrometallurgical treatment of this fuel was demonstrated. Advanced metallic fuels are now investigated for increased performance, including ultra-high burnup and actinide burning. Advances include additives to mitigate the fuel/cladding chemical interaction and uranium alloys that combine Mo, Ti and Zr to improve alloy performance. The impacts of the advances—on fabrication, waste streams, electrorefining, etc.—are found to be minimal and beneficial. Owing to extensive research literature and computational methods, only a modest effort is required to complete their development.

  2. Chemomechanical interactions resulting from fuel-alkali metal reactions inside LMFBR oxide fuel elements

    SciTech Connect

    Adamson, M.G.; Vaidyanathan, S.; Bottcher, J.H.; Hofman, G.L.

    1982-01-01

    Chemomechanical interactions inside metal-clad fuel elements are defined as those fuel-cladding mechanical interactions (FCMI) that are influenced by or result from chemical reactions between constituents of the irradiated fuel system. The purpose of the present paper is to interpret some recent experimental and analytical results in terms of chemomechanical reaction mechanisms, with special emphasis on the modeling of breached LMFBR oxide fuel pin behavior.

  3. Progress in the development of metallic fuel in fast reactors

    SciTech Connect

    Seidel, B.R.; Walters, L.C.

    1988-01-01

    Renewed interest has developed in metallic fuel for fast reactors as a result of Argonne National Laboratory's integral fast reactor (IFR) concept. This concept involves a novel approach to fuel-cycle closure that is based on metal reprocessing and injection-casting fabrication. This paper delves into recent developments associated with the performance of metallic fuels. In February of 1985, three full assemblies of advanced metallic fuel were placed in the core of the Experimental Breeder Reactor II (EBR-II). The 61-pin assemblies each contained an identical complement of metallic fuel of three compositions: U-10 Zr, U-8 Pu-10 Zr, and U-19 Pu-10 Zr. The pins were clad with the austenitic D9, had linear power rating of 15 kW/ft, and achieved peak cladding temperatures of 600{degree}C. The burnup achieved to date on these pins is 14 at.% burnup without any failures, and the irradiation continues. These lead assemblies have demonstrated that metallic fuels have the potential of being competitive with any existing fuel type in terms of steady-state performance.

  4. Dimensional, microstructural and compositional stability of metal fuels

    SciTech Connect

    Solomon, A.A.; Dayananda, M.A.

    1993-03-15

    The projects undertaken were to address two areas of concern for metal-fueled fast reactors: metallurgical compatibility of fuel and its fission products with the stainless steel cladding, and effects of porosity development in the fuel on fuel/cladding interactions and on sodium penetration in fuel. The following studies are reported on extensively in appendices: hot isostatic pressing of U-10Zr by coupled boundary diffusion/power law creep cavitation, liquid Na intrusion into porous U-10Zr fuel alloy by differential capillarity, interdiffusion between U-Zr fuel and selected Fe-Ni-Cr alloys, interdiffusion between U-Zr fuel vs selected cladding steels, and interdiffusion of Ce in Fe-base alloys with Ni or Cr.

  5. Metal Matrix Microencapsulated (M3) fuel neutronics performance in PWRs

    SciTech Connect

    Fratoni, Massimiliano; Terrani, Kurt A

    2012-01-01

    Metal Matrix Microencapsulated (M3) fuel consists of TRISO or BISO coated fuel particles directly dispersed in a matrix of zirconium metal to form a solid rod (Fig. 1). In this integral fuel concept the cladding tube and the failure mechanisms associated with it have been eliminated. In this manner pellet-clad-interactions (PCI), thin tube failure due to oxidation and hydriding, and tube pressurization and burst will be absent. M3 fuel, given the high stiffness of the integral rod design, could as well improve grid-to-rod wear behavior. Overall M3 fuel, compared to existing fuel designs, is expected to provide greatly improved operational performance. Multiple barriers to fission product release (ceramic coating layers in the coated fuel particle and te metal matrix) and the high thermal conductivity zirconium alloy metal matrix contribute to the enhancement in fuel behavior. The discontinuous nature of fissile material encapsulated in coated particles provides additional assistance; for instance if the M3 fuel rod is snapped into multiple pieces, only the limited number of fuel particles at the failure cross section are susceptible to release fission products. This is in contrast to the conventional oxide fuel where the presence of a small opening in the cladding provides the pathway for release of the entire inventory of fission products from the fuel rod. While conventional metal fuels (e.g. U-Zr and U-Mo) are typically expected to experience large swelling under irradiation due to the high degree of damage from fission fragments and introduction of fission gas into the lattice, this is not the case for M3 fuels. The fissile portion of the fuel is contained within the coated particle where enough room is available to accommodate fission gases and kernel swelling. The zirconium metal matrix will not be exposed to fission products and its swelling is known to be very limited when exposed solely to neutrons. Under design basis RIA and LOCA, fuel performance will be

  6. Highly Dispersed Metal Catalyst for Fuel Cell Electrodes

    SciTech Connect

    2009-03-01

    This factsheet describes a study that will bring industrial catalyst experience to fuel cell research. Specifically, industrial catalysts, such as those used in platforming, utilize precious metal platinum as an active component in a finely dispersed form.

  7. Fuel cell with metal screen flow-field

    DOEpatents

    Wilson, Mahlon S.; Zawodzinski, Christine

    1998-01-01

    A polymer electrolyte membrane (PEM) fuel cell is provided with electrodes supplied with a reactant on each side of a catalyzed membrane assembly (CMA). The fuel cell includes a metal mesh defining a rectangular flow-field pattern having an inlet at a first corner and an outlet at a second corner located on a diagonal from the first corner, wherein all flow paths from the inlet to the outlet through the square flow field pattern are equivalent to uniformly distribute the reactant over the CMA. In a preferred form of metal mesh, a square weave screen forms the flow-field pattern. In a particular characterization of the present invention, a bipolar plate electrically connects adjacent fuel cells, where the bipolar plate includes a thin metal foil having an anode side and a cathode side; a first metal mesh on the anode side of the thin metal foil; and a second metal mesh on the cathode side of the thin metal foil. In another characterization of the present invention, a cooling plate assembly cools adjacent fuel cells, where the cooling plate assembly includes an anode electrode and a cathode electrode formed of thin conducting foils; and a metal mesh flow field therebetween for distributing cooling water flow over the electrodes to remove heat generated by the fuel cells.

  8. Fuel cell with metal screen flow-field

    DOEpatents

    Wilson, Mahlon S.; Zawodzinski, Christine

    2001-01-01

    A polymer electrolyte membrane (PEM) fuel cell is provided with electrodes supplied with a reactant on each side of a catalyzed membrane assembly (CMA). The fuel cell includes a metal mesh defining a rectangular flow-field pattern having an inlet at a first corner and an outlet at a second corner located on a diagonal from the first corner, wherein all flow paths from the inlet to the outlet through the square flow field pattern are equivalent to uniformly distribute the reactant over the CMA. In a preferred form of metal mesh, a square weave screen forms the flow-field pattern. In a particular characterization of the present invention, a bipolar plate electrically connects adjacent fuel cells, where the bipolar plate includes a thin metal foil having an anode side and a cathode side; a first metal mesh on the anode side of the thin metal foil; and a second metal mesh on the cathode side of the thin metal foil. In another characterization of the present invention, a cooling plate assembly cools adjacent fuel cells, where the cooling plate assembly includes an anode electrode and a cathode electrode formed of thin conducting foils; and a metal mesh flow field therebetween for distributing cooling water flow over the electrodes to remove heat generated by the fuel cells.

  9. Fuel cell with metal screen flow-field

    DOEpatents

    Wilson, M.S.; Zawodzinski, C.

    1998-08-25

    A polymer electrolyte membrane (PEM) fuel cell is provided with electrodes supplied with a reactant on each side of a catalyzed membrane assembly (CMA). The fuel cell includes a metal mesh defining a rectangular flow-field pattern having an inlet at a first corner and an outlet at a second corner located on a diagonal from the first corner, wherein all flow paths from the inlet to the outlet through the square flow field pattern are equivalent to uniformly distribute the reactant over the CMA. In a preferred form of metal mesh, a square weave screen forms the flow-field pattern. In a particular characterization of the present invention, a bipolar plate electrically connects adjacent fuel cells, where the bipolar plate includes a thin metal foil having an anode side and a cathode side; a first metal mesh on the anode side of the thin metal foil; and a second metal mesh on the cathode side of the thin metal foil. In another characterization of the present invention, a cooling plate assembly cools adjacent fuel cells, where the cooling plate assembly includes an anode electrode and a cathode electrode formed of thin conducting foils; and a metal mesh flow field there between for distributing cooling water flow over the electrodes to remove heat generated by the fuel cells. 11 figs.

  10. Disposition of Unirradiated Sodium Bonded EBR-II Driver Fuel Elements and HEU Scrap: Work Performed for FY 2007

    SciTech Connect

    Karen A Moore

    2007-04-01

    Specific surplus high enriched uranium (HEU) materials at the Idaho National Laboratory (INL) Materials and Fuels Complex (MFC) will be transferred to a designated off-site receiving facility. The DOE High Enriched Uranium Disposition Program Office (HDPO) will determine which materials, if any, will be prepared and transferred to an off-site facility for processing and eventual fabrication of fuel for nuclear reactors. These surplus HEU materials include approximately 7200 kg unirradiated sodium-bonded EBR-II driver fuel elements, and nearly 800 kg of HEU casting scrap from the process which formed various sodium-bonded fuels (including the EBR-II driver elements). Before the driver fuel can be packaged for shipment, the fuel elements will require removal of the sodium bond. The HEU scrap will also require repackaging in preparation for off-site transport. Preliminary work on this task was authorized by BWXT Y-12 on Nov 6, 2006 and performed in three areas: • Facility Modifications • Safety Documentation • Project Management

  11. Novel fuel cell stack with coupled metal hydride containers

    NASA Astrophysics Data System (ADS)

    Liu, Zhixiang; Li, Yan; Bu, Qingyuan; Guzy, Christopher J.; Li, Qi; Chen, Weirong; Wang, Cheng

    2016-10-01

    Air-cooled, self-humidifying hydrogen fuel cells are often used for backup and portable power sources, with a metal hydride used as the hydrogen storage material. To provide a stable hydrogen flow to the fuel cell stack, heat must be provided to the metal hydride. Conventionally, the heat released from the exothermic reaction of hydrogen and oxygen in the fuel cell stack to the exhaust air is used to heat a separate metal hydride container. In this case, the heat is only partially used instead of being more closely coupled because of the heat transfer resistances in the system. To achieve better heat integration, a novel scheme is proposed whereby hydrogen storage and single fuel cells are more closely coupled. Based on this idea, metal hydride containers in the form of cooling plates were assembled between each pair of cells in the stack so that the heat could be directly transferred to a metal hydride container of much larger surface-to-volume ratio than conventional separate containers. A heat coupled fuel cell portable power source with 10 cells and 11 metal hydride containers was constructed and the experimental results show that this scheme is beneficial for the heat management of fuel cell stack.

  12. Studies of prefailure fuel extrusion in metal fuel pins with EXTRUS

    SciTech Connect

    Hummel, H H; Pizzica, P A

    1988-02-01

    A SAS4A module, EXTRUS, available in a special version of SAS4A, has been prepared to deal with prefailure metal fuel extrusion in a slow TOP accident, as an alternative to the PINACLE module. Results of calculation of prefailure fuel extrusion for the TREAT M4 experiment as calculated in SAS4A by PINACLE and by EXTRUS have been compared. The questions of the importance for metal fuel of inpin axial fuel distribution on fuel motion reactivity effects and of dynamic effects on prefailure molten fuel extrusion have been investigated using the PINACLE and EXTRUS modules of SAS4A. Calculations with the EXTRUS module have been performed for the 1.9% burnup pin in the F2 M5 TREAT experiment to try to understand the low molten fuel extrusion of only 1 to 2% observed. The M6 experiment showed extrusion of 3 to 5%, considerably larger than that in M5. Fuel clad failure conditions and prefailure fuel extrusion for prototypical SAFR metal fuel pins have been investigated for a programmed power history typical of a .1$/sec transient overpower accident.

  13. Evaluation of Metal-Fueled Surface Reactor Concepts

    SciTech Connect

    Poston, David I.; Marcille, Thomas F.; Kapernick, Richard J.; Hiatt, Matthew T.; Amiri, Benjamin W.

    2007-01-30

    Surface fission power systems for use on the Moon and Mars may provide the first use of near-term reactor technology in space. Most near-term surface reactor concepts specify reactor temperatures <1000 K to allow the use of established material and power conversion technology and minimize the impact of the in-situ environment. Metal alloy fuels (e.g. U-10Zr and U-10Mo) have not traditionally been considered for space reactors because of high-temperature requirements, but they might be an attractive option for these lower temperature surface power missions. In addition to temperature limitations, metal fuels are also known to swell significantly at rather low fuel burnups ({approx}1 a/o), but near-term surface missions can mitigate this concern as well, because power and lifetime requirements generally keep fuel burnups <1 a/o. If temperature and swelling issues are not a concern, then a surface reactor concept may be able to benefit from the high uranium density and relative ease of manufacture of metal fuels. This paper investigates two reactor concepts that utilize metal fuels. It is found that these concepts compare very well to concepts that utilize other fuels (UN, UO2, UZrH) on a mass basis, while also providing the potential to simplify material safeguards issues.

  14. A novel microstructured metal-supported solid oxide fuel cell

    NASA Astrophysics Data System (ADS)

    Fernández-González, R.; Hernández, E.; Savvin, S.; Núñez, P.; Makradi, A.; Sabaté, N.; Esquivel, J. P.; Ruiz-Morales, J. C.

    2014-12-01

    An innovative design, alternative to the conventional metal supported fuel cells (MSC) is proposed. This new design of Solid Oxide Fuel Cell (SOFC), comprises a 200 μm layer of a honeycomb-metallic framework with hexagonal cells which supports a 250 μm layer of electrolyte. Each hexagonal cell is further functionalized with a thin 5-10 μm of Ni-YSZ anode. This new design allows a reduction of ∼65% of the metallic supporting material, rendering performances over 300 mW cm-2 under pure hydrogen at 850 °C, with an OCV of ∼1.1 V.

  15. Modeling Constituent Redistribution in U-Pu-Zr Metallic Fuel Using the Advanced Fuel Performance Code BISON

    SciTech Connect

    Douglas Porter; Steve Hayes; Various

    2014-06-01

    The Advanced Fuels Campaign (AFC) metallic fuels currently being tested have higher zirconium and plutonium concentrations than those tested in the past in EBR reactors. Current metal fuel performance codes have limitations and deficiencies in predicting AFC fuel performance, particularly in the modeling of constituent distribution. No fully validated code exists due to sparse data and unknown modeling parameters. Our primary objective is to develop an initial analysis tool by incorporating state-of-the-art knowledge, constitutive models and properties of AFC metal fuels into the MOOSE/BISON (1) framework in order to analyze AFC metallic fuel tests.

  16. Metallic Fuel Casting Development and Parameter Optimization Simulations

    SciTech Connect

    R.S. Fielding; J. Crapps; C. Unal; J.R. Kennedy

    2013-03-01

    One of the advantages of metallic fuel is the abilility to cast the fuel slugs to near net shape with little additional processing. However, the high aspect ratio of the fuel is not ideal for casting. EBR-II fuel was cast using counter gravity injection casting (CGIC) but, concerns have been raised concerning the feasibility of this process for americium bearing alloys. The Fuel Cycle Research and Development program has begun developing gravity casting techniques suitable for fuel production. Compared to CGIC gravity casting does not require a large heel that then is recycled, does not require application of a vacuum during melting, and is conducive to re-usable molds. Development has included fabrication of two separate benchscale, approximately 300 grams, systems. To shorten development time computer simulations have been used to ensure mold and crucible designs are feasible and to identify which fluid properties most affect casting behavior and therefore require more characterization.

  17. Metal matrix composite fuel for space radioisotope energy sources

    NASA Astrophysics Data System (ADS)

    Williams, H. R.; Ning, H.; Reece, M. J.; Ambrosi, R. M.; Bannister, N. P.; Stephenson, K.

    2013-02-01

    Radioisotope fuels produce heat that can be used for spacecraft thermal control or converted to electricity. They must retain integrity in the event of destruction or atmospheric entry of the parent spacecraft. Addition of a metal matrix to the actinide oxide could yield a more robust fuel form. Neodymium (III) oxide (Nd2O3) - niobium metal matrix composites were produced using Spark Plasma Sintering; Nd2O3 is a non-radioactive surrogate for americium (III) oxide (Am2O3). Two compositions, 70 and 50 wt% Nd2O3, were mechanically tested under equibiaxial (ring-on-ring) flexure according to ASTM C1499. The addition of the niobium matrix increased the mean flexural strength by a factor of about 2 compared to typical ceramic nuclear fuels, and significantly increased the Weibull modulus to over 20. These improved mechanical properties could result in reduced fuel dispersion in severe accidents and improved safety of space radioisotope power systems.

  18. Metal Nanoshells for Plasmonically Enhanced Solar to Fuel Photocatalytic Conversion

    DTIC Science & Technology

    2016-05-18

    AFRL-AFOSR-JP-TR-2016-0075 Metal Nanoshells for Plasmonically Enhanced Solar to Fuel Photocatalytic Conversion Randall Lee UNIVERSITY OF HOUSTON... Solar to Fuel Photocatalytic Conversion 5a.  CONTRACT NUMBER 5b.  GRANT NUMBER FA2386-14-1-4074 5c.  PROGRAM ELEMENT NUMBER 61102F 6. AUTHOR(S) Randall...redistribution of the absorbed energy via various dissipative mechanisms. This energy transfer can enhance the photoactivity of the system because ZIS

  19. Apparatus for injection casting metallic nuclear energy fuel rods

    DOEpatents

    Seidel, Bobby R.; Tracy, Donald B.; Griffiths, Vernon

    1991-01-01

    Molds for making metallic nuclear fuel rods are provided which present reduced risks to the environment by reducing radioactive waste. In one embodiment, the mold is consumable with the fuel rod, and in another embodiment, part of the mold can be re-used. Several molds can be arranged together in a cascaded manner, if desired, or several long cavities can be integrated in a monolithic multiple cavity re-usable mold.

  20. Low Cost PEM Fuel Cell Metal Bipolar Plates

    SciTech Connect

    Wang, Conghua

    2013-05-30

    Bipolar plate is an important component in fuel cell stacks and accounts for more than 75% of stack weight and volume. The technology development of metal bipolar plates can effectively reduce the fuel cells stack weight and volume over 50%. The challenge is the metal plate corrosion protection at low cost for the broad commercial applications. This project is aimed to develop innovative technological solutions to overcome the corrosion barrier of low cost metal plates. The feasibility of has been demonstrated and patented (US Patent 7,309,540). The plan is to further reduce the cost, and scale up the technology. The project is built on three pillars: 1) robust experimental evidence demonstrating the feasibility of our technology, 2) a team that consists of industrial leaders in fuel cell stack application, design, and manufactures; 3) a low-risk, significant-milestone driven program that proves the feasibility of meeting program objectives The implementation of this project will reduce the fuel cell stack metal bipolar separator plate cost which accounts 15-21% of the overall stack cost. It will contribute to the market adoption of fuel cell technologies. In addition, this corrosion protection technology can be used similar energy devices, such as batteries and electrolyzers. Therefore, the success of the project will be benefit in broad markets.

  1. Vibrocompacted fuel for the liquid-metal FBR BOR 60

    SciTech Connect

    Herbig, R.; Rudolph, K.; Lindau, B. ); Skiba, O.V. )

    1992-01-01

    In view of fuel element refabrication on a highly radioactive and toxic level, a technology based on vibrocompacted granular fuel with consequent automation and remote control was developed. The main advantage of the granular technology is to enable the insertion of getter materials, e.g., metallic uranium, to control the U/Pu-O ratio, influence the thermodynamic state of the fuel, control the chemical state of fission products, and absorb impurities. The corrosion of the inner surface in this way may be lowered to a negligible depth. Future developments will lead to accomplished vibrotechnology by a controlled gravimetric dosing method.

  2. Performance and design considerations in metal fueled cores. [LMFBR

    SciTech Connect

    Orechwa, Y.; Khalil, H.; Turski, R.B.

    1984-01-01

    To focus future metal fuel development requirements a study was performed to quantify the relationship between some critical core design parameters. The fuel studied was U-Pu-Zr alloy. Of interest are performance parameters, such as peak Pu enrichment, burnup swing, fast fluence, breeding ratio, and their relation to core parameters such as reactor size, degree of core heterogeneity, pin diameter, and linear heat rating. These performance parameters, while numericaly different from those of ceramic fuels, were found to exhibit the same qualitative dependence on the key design variables.

  3. Metallic Fast Reactor Fuel Fabrication for Global Nuclear Energy Partnership

    SciTech Connect

    Douglas E. Burkes; Randall S. Fielding; Douglas L. Porter

    2009-07-01

    Fast reactors are once again being considered for nuclear power generation, in addition to transmutation of long-lived fission products resident in spent nuclear fuels. This re-consideration follows with intense developmental programs for both fuel and reactor design. One of the two leading candidates for next generation fast reactor fuel is metal alloys, resulting primarily from the successes achieved in the 1960s to early 1990s with both the experimental breeding reactor-II and the fast flux test facility. The goal of the current program is to develop and qualify a nuclear fuel system that performs all of the functions of a conventional, fast-spectrum nuclear fuel while destroying recycled actinides, thereby closing the nuclear fuel cycle. In order to meet this goal, the program must develop efficient and safe fuel fabrication processes designed for remote operation. This paper provides an overview of advanced casting processes investigated in the past, and the development of a gaseous diffusion calculation that demonstrates how straightforward process parameter modification can mitigate the loss of volatile minor actinides in the metal alloy melt.

  4. Temperature and burnup correlated fuel-cladding chemical interaction in U-10ZR metallic fuel

    NASA Astrophysics Data System (ADS)

    Carmack, William J.

    Metallic fuels are proposed for use in advanced sodium cooled fast reactors and provide a number of advantages over other fuel types considering their fabricability, performance, recyclability, and safety. Resistance to cladding "breach" and subsequent release of fission products and fuel constituents to the nuclear power plant primary coolant system is a key performance parameter for a nuclear fuel system. In metallic fuel, FCCI weakens the cladding, especially at high power-high temperature operation, contributing to fuel pin breach. Empirical relationships for FCCI have been developed from a large body of data collected from in-pile (EBR-II) and out-of-pile experiments [1]. However, these relationships are unreliable in predicting FCCI outside the range of EBR-II experimental data. This dissertation examines new FCCI data extracted from the MFF-series of prototypic length metallic fuel irradiations performed in the Fast Flux Test Facility (FFTF). The fuel in these assemblies operated a temperature and burnup conditions similar to that in EBR-II but with axial fuel height three times longer than EBR-II experiments. Comparing FCCI formation data from FFTF and EBR-II provides new insight into FCCI formation kinetics. A model is developed combining both production and diffusion of lanthanides to the fuel-cladding interface and subsequent reaction with the cladding. The model allows these phenomena to be influenced by fuel burnup (lanthanide concentrations) and operating temperature. Parameters in the model are adjusted to reproduce measured FCCI layer thicknesses from EBR-II and FFTF. The model predicts that, under appropriate conditions, rate of FCCI formation can be controlled by either fission product transport or by the reaction rate of the interaction species at the fuel-cladding interface. This dissertation will help forward the design of metallic fuel systems for advanced sodium cooled fast reactors by allowing the prediction of FCCI layer formation in full

  5. Irradiation performance of U-Pu-Zr metal fuels for liquid-metal-cooled reactors

    SciTech Connect

    Tsai, H.; Cohen, A.B.; Billone, M.C.; Neimark, L.A.

    1994-10-01

    This report discusses a fuel system utilizing metallic U-Pu-Zr alloys which has been developed for advanced liquid metal-cooled reactors (LMRs). Result`s from extensive irradiation testing conducted in EBR-II show a design having the following key features can achieve both high reliability and high burnup capability: a cast nominally U-20wt %Pu-10wt %Zr slug with the diameter sized to yield a fuel smear density of {approx}75% theoretical density, low-swelling tempered martensitic stainless steel cladding, sodium bond filling the initial fuel/cladding gap, and an as-built plenum/fuel volume ratio of {approx}1.5. The robust performance capability of this design stems primarily from the negligible loading on the cladding from either fuel/cladding mechanical interaction or fission-gas pressure during the irradiation. The effects of these individual design parameters, e.g., fuel smear density, zirconium content in fuel, plenum volume, and cladding types, on fuel element performance were investigated in a systematic irradiation experiment in EBR-II. The results show that, at the discharge burnup of {approx}11 at. %, variations on zirconium content or plenum volume in the ranges tested have no substantial effects on performance. Fuel smear density, on the other hand, has pronounced but countervailing effects: increased density results in greater cladding strain, but lesser cladding wastage from fuel/cladding chemical interaction.

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

    SciTech Connect

    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.

  7. Assessment of ceramic coatings for metal fuel melting crucible

    SciTech Connect

    Kim, Ki-Hwan; Song, Hoon; Kim, Jong-Hwan; Oh, Seok-Jin; Kim, Hyung-Tae; Lee, Chan-Bock

    2013-07-01

    The objective of this study is to develop a coating method and material for crucibles to prevent material interactions with the U-Zr/U-TRU-Zr fuels during the manufacturing of SFR fuels. Refractory coatings were applied to niobium substrates by vacuum plasma-spray coating method. Melt dipping tests conducted were the coated rods lowered into the fuel melt at 1600 C. degrees, and withdrawn and cooled outside the crucible in the inert atmosphere of the induction furnace. Melt dipping tests of the coated Nb rods indicated that plasma-sprayed Y{sub 2}O{sub 3} coating doesn't form significant reaction layer between fuel melt and coating layer. Melt dipping tests of the coated Nb rods showed that TiC, TaC, and Y{sub 2}O{sub 3} coatings exhibited the promising performance among other ceramic coatings. These materials could be promising candidate materials for the reusable melt crucible of metal fuel for SFR. In addition, in order to develop the vacuum plasma-spray coating method for re-usable crucible of metal fuel slugs to be overcome the issue of thermal expansion mismatch between coating material and crucible, various combinations of coating conditions were investigated to find the bonding effect on the substrate in pursuit of more effective ways to withstand the thermal stresses. It is observed that most coating methods maintained sound coating state in U-Zr melt. (authors)

  8. Coated metal sintering carriers for fuel cell electrodes

    SciTech Connect

    Donelson, Richard; Bryson, E. S.

    1998-01-01

    A carrier for conveying components of a fuel cell to be sintered through a sintering furnace. The carrier comprises a metal sheet coated with a water-based carbon paint, the water-based carbon paint comprising water, powdered graphite, an organic binder, a wetting agent, a dispersing agent and a defoaming agent.

  9. Coated metal sintering carriers for fuel cell electrodes

    DOEpatents

    Donelson, R.; Bryson, E.S.

    1998-11-10

    A carrier is described for conveying components of a fuel cell to be sintered through a sintering furnace. The carrier comprises a metal sheet coated with a water-based carbon paint, the water-based carbon paint comprising water, powdered graphite, an organic binder, a wetting agent, a dispersing agent and a defoaming agent.

  10. Fission gas retention and axial expansion of irradiated metallic fuel

    SciTech Connect

    Fenske, G.R.; Emerson, J.E.; Savoie, F.E.; Johanson, E.W.

    1986-05-01

    Out-of-reactor experiments utilizing direct electrical heating and infrared heating techniques were performed on irradiated metallic fuel. The results indicate accelerated expansion can occur during thermal transients and that the accelerated expansion is driven by retained fission gases. The results also demonstrate gas retention and, hence, expansion behavior is a function of axial position within the pin.

  11. Yttrium and rare earth stabilized fast reactor metal fuel

    SciTech Connect

    Guon, J.; Grantham, L.F.; Specht, E.R.

    1992-05-12

    This patent describes an improved metal alloy reactor fuel consisting essentially of uranium, plutonium, and at least one element from the group consisting of yttrium, lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium and lutetium.

  12. Fuel/cladding compatibility in irradiated metallic fuel pins at elevated temperatures

    SciTech Connect

    Tsai, Hanchung.

    1990-04-01

    Over fifty fuel/cladding compatibility tests on irradiated metallic fuel specimens have been conducted in an in-cell facility at elevated temperatures. At temperatures below 700--725{degree}C, no fuel/cladding interaction was noted in tests up to 7 h. Liquid-phase cladding penetration occurred in some of the tests at temperatures greater than 725--750{degree}C. The effective rates of liquid- phase cladding penetration of six different fuel/cladding combinations during 1-h testing are reported. After the initial liquefaction at the fuel/cladding interface, which may be affected by the solid-state diffusional interaction during the steady-state irradiation, the rate of further cladding penetration stays constant or decreases with time. There was no runaway cladding penetration in the latter part of a heating cycle.

  13. Fuel damage during off-normal transients in metal-fueled fast reactors

    SciTech Connect

    Kramer, J.M.; Bauer, T.H.

    1990-01-01

    Fuel damage during off-normal transients is a key issue in the safety of fast reactors because the fuel pin cladding provides the primary barrier to the release of radioactive materials. Part of the Safety Task of the Integral Fast Reactor Program is to provide assessments of the damage and margins to failure for metallic fuels over the wide range of transients that must be considered in safety analyses. This paper reviews the current status of the analytical and experimental programs that are providing the bases for these assessments. 13 refs., 2 figs.

  14. Review of fuel/cladding eutectic formation in metallic SFR fuel pins

    SciTech Connect

    Denman, M.; Todreas, N.; Driscoll, M.

    2012-07-01

    Sodium-cooled Fast Reactors (SFRs) remain a strong contender amongst the Generation IV reactor concepts. Metallic fuel has been a primary fuel option for SFR designers in the US and was used extensively in the first generation of SFRs. One of the benefits of metallic fuel is its chemical compatibility with the coolant; unfortunately this compatibility does not extend to steel cladding at elevated temperatures. It has been known that uranium, plutonium, and rare earths diffuse with cladding constituents to form a low melting point fuel/cladding eutectic which acts to thin the cladding once the interfacial temperature rises above the system liquidus temperature. Since the 1960's, many experiments have been performed and published to evaluate the rate of fuel/cladding eutectic formation and the temperature above which melting will begin as a function of fuel/cladding interfacial temperature, time at temperature, fuel constituents (uranium, fissium or uranium (plutonium) zirconium), cladding type (stainless steel 316, stainless steel 306, D9 or HT9), beginning of life linear power, plutonium enrichment and burnup. The results of these tests, however, remain scattered across conference and journal papers spanning 50 years. The tests used to collect this data also varied in experimental procedure throughout the years. This paper will consolidate the experimental data into four groups of similar test conditions and expand upon the testing performed for each group in detail. A companion paper in PSA 2011 will discuss predictive correlations formulated from this database. (authors)

  15. Irradiation-Induced Thermal Effects in Alloyed Metal Fuel of Fast Reactors

    NASA Astrophysics Data System (ADS)

    Kryukov, F. N.; Nikitin, O. N.; Kuzmin, S. V.; Belyaeva, A. V.; Gilmutdinov, I. F.; Grin, P. I.; Zhemkov, I. Yu

    2017-01-01

    The paper presents the results of studying alloyed metal fuel after irradiation in a fast reactor. Determined is the mechanism of fuel irradiation swelling, mechanical interaction between fuel and cladding, and distribution of fission products. Experience gained in fuel properties and behavior under irradiation as well as in irradiation-induced thermal effects occurred in alloyed metal fuel provides for a fuel pin design to have a burnup not less than 20% h. a.

  16. Casting of metallic fuel containing minor actinide additions

    NASA Astrophysics Data System (ADS)

    Trybus, C. L.; Sanecki, J. E.; Henslee, S. P.

    1993-09-01

    Metallic U-20%Pu-10%Zr (by weight) nuclear fuel was injection cast with the addition of two minor actinides, 2.1% Am and 1.3% Np. Three full length fuel slugs (4.3 mm × 340 mm) were successfully cast incorporating both Np and Am. No unusual macrosegregation of the major constituents was observed. About 60% of the initial Am and 100% of the Np charge was present in the as-cast fuel. Am loss was attributed to volatile contaminants in the feed stock and evaporation at the casting temperature (1465°C). Microstructural and microchemical characterization of the as-cast fuel along with bulk chemical analyses are reported.

  17. Metal bipolar plates for PEM fuel cell-A review

    NASA Astrophysics Data System (ADS)

    Tawfik, H.; Hung, Y.; Mahajan, D.

    The polymer electrolyte membrane (PEM) based fuel cells are clean alternative energy systems that hold excellent potential for cost effectiveness, durability, and relatively high overall efficiency. PEM fuel cell is recognized by the U.S. Department of Energy (DOE) as the main candidate to replace the internal combustion engine in transportation applications. Metallic bipolar plates and membrane electrode assembly (MEA) are two crucial components of a PEM power stack and their durability and fabrication cost must be optimized to allow fuel cells to penetrate the commercial market and compete with other energy sources. The bipolar plates perform as the current conductors between cells, provide conduits for reactant gases flow, and constitute the backbone of a power stack. They are commonly made of graphite composite for high corrosion resistance and good surface contact resistance; however their manufacturability, permeability, and durability for shock and vibration are unfavorable in comparison to metals. On the other hand, various methods and techniques must be developed to combat metallic corrosion and eliminate the passive layer that causes unacceptable reduction in contact resistance and possible fouling of the catalyst and the ionomer. Thus recently metallic bipolar plates have received considerable attention in the research community. This paper offers a comprehensive review of the research work conducted on metal bipolar plates to prevent corrosion while maintaining a low contact resistance.

  18. Emissions of fuel metals content from a diesel vehicle engine

    NASA Astrophysics Data System (ADS)

    Wang, Ya-Fen; Huang, Kuo-Lin; Li, Chun-Teh; Mi, Hsiao-Hsuan; Luo, Jih-Haur; Tsai, Perng-Jy

    This study was set out to assess the characteristics and significance of metal contents emitted from diesel engines. We found that the emitted concentrations of crust elements (including Al, Ca, Fe, Mg, and Si) were much higher than those of anthropogenic elements (including Ag, Ba, Cd, Co, Cr, Cu, Mn, Mo, Ni, Pb, Sb, Sr, Ti, V, and Zn) from diesel vehicle engine exhausts under the transient-cycle condition. The emission concentrations of particulate matters from diesel vehicle engine were inversely proportional to the specified engine speeds. To the contrary, the increase of engine speeds resulted in increase of fractions of metal contents in particulate matters. We conducted simple linear regression analysis to relate the emission rates of the metal contents in vehicle exhaust to the consumption rates of metal contents in diesel fuel. This study yielded R2=0.999 which suggests that the emission of the metal contents in vehicle exhaust could be fully explained by the consumption of metal contents in diesel fuel. For illustration, we found that the annual emission rates of both crust and anthropogenic elements from all diesel engine vehicles (=269 000 and 58 700 kg yr -1, respectively) were significantly higher than those from the coal power plant, electrical arc furnace, and coke oven (=90 100 and 1660 kg yr -1, 2060 and 173 kg yr -1, and 60 500 and 3740 kg yr -1, respectively) in Taiwan area. The relatively high amount of metal contents emitted from diesel engines strongly suggests that the measurement on the control of metal contents in diesel fuel should be taken in the future.

  19. Metal-Free Motifs for Solar Fuel Applications

    NASA Astrophysics Data System (ADS)

    Ilic, Stefan; Zoric, Marija R.; Kadel, Usha Pandey; Huang, Yunjing; Glusac, Ksenija D.

    2017-05-01

    Metal-free motifs, such as graphitic carbon nitride, conjugated polymers, and doped nanostructures, are emerging as a new class of Earth-abundant materials for solar fuel devices. Although these metal-free structures show great potential, detailed mechanistic understanding of their performance remains limited. Here, we review important experimental and theoretical findings relevant to the role of metal-free motifs as either photoelectrodes or electrocatalysts. First, the light-harvesting characteristics of metal-free photoelectrodes (band energetics, exciton binding energies, charge carrier mobilities and lifetimes) are discussed and contrasted with those in traditional inorganic semiconductors (such as Si). Second, the mechanistic insights into the electrocatalytic oxygen reduction and evolution reactions, hydrogen evolution reaction, and carbon dioxide reduction reaction by metal-free motifs are summarized, including experimental surface-sensitive spectroscopy findings, studies on small molecular models, and computational modeling of these chemical transformations.

  20. Metal hydride fuel storage and method thereof

    DOEpatents

    Morse, Jeffrey D [Martinez, CA; Jankowski, Alan F [Livermore, CA; Yu, Conrad [Antioch, CA

    2010-08-10

    An apparatus having a first substrate having (1) a cavity, (2) one or more resistive heaters, and (3) one or more coatings forming a diffusion barrier to hydrogen; a second substrate having (1) an outlet valve comprising a pressure relief structure and (2) one or more coatings forming a diffusion barrier to hydrogen, wherein said second substrate is coupled to said first substrate forming a sealed volume in said cavity; a metal hydride material contained within said cavity; and a gas distribution system formed by coupling a microfluidic interconnect to said pressure relief structure. Additional apparatuses and methods are also disclosed.

  1. Metallic hydrogen: The most powerful rocket fuel yet to exist

    NASA Astrophysics Data System (ADS)

    Silvera, Isaac F.; Cole, John W.

    2010-03-01

    Wigner and Huntington first predicted that pressures of order 25 GPa were required for the transition of solid molecular hydrogen to the atomic metallic phase. Later it was predicted that metallic hydrogen might be a metastable material so that it remains metallic when pressure is released. Experimental pressures achieved on hydrogen have been more than an order of magnitude higher than the predicted transition pressure and yet it remains an insulator. We discuss the applications of metastable metallic hydrogen to rocketry. Metastable metallic hydrogen would be a very light-weight, low volume, powerful rocket propellant. One of the characteristics of a propellant is its specific impulse, Isp. Liquid (molecular) hydrogen-oxygen used in modern rockets has an Isp of ~460s; metallic hydrogen has a theoretical Isp of 1700s! Detailed analysis shows that such a fuel would allow single-stage rockets to enter into orbit or carry economical payloads to the moon. If pure metallic hydrogen is used as a propellant, the reaction chamber temperature is calculated to be greater than 6000 K, too high for currently known rocket engine materials. By diluting metallic hydrogen with liquid hydrogen or water, the reaction temperature can be reduced, yet there is still a significant performance improvement for the diluted mixture.

  2. Adsorption of spent fuel storage pool contaminants into metal surfaces

    SciTech Connect

    Reaves, K.; Kunze, J.; Lu, Kang ); Bennett, P.C. )

    1990-01-01

    Shipping casks, after being submerged in spent fuel pools for the purpose of loading or unloading fuel, resist complete removal of the adsorbed contamination. To systematically study the mechanisms involved, 122 metal surface samples were immersed in the spent fuel storage pool of the Callaway Power Plant for periods of 7 to 30 days. After being removed from the pool, all samples were washed and wiped (with cloth) using demineralized water. They were then gamma counted for absolute activity, by using Eu-152 as an energy efficiency calibrator, applied uniformly to unexposed sample surfaces. Swipes were taken after each of 3 days of such environmental conditioning. Following this conditioning, selected samples were again counted to determine absolute contamination remaining on the samples. 2 refs., 1 tab.

  3. Performance of metal and oxide fuel cores during accidents in large liquid-metal-cooled reactors

    SciTech Connect

    Royl, P.H.; Kussmaul, G. ); Cahalan, J.E.; Wigeland, R.A. ); Friedel, G. ); Moreau, J. ); Perks, M. )

    1992-02-01

    This paper reports on a cooperative effort among European and U.S. analysts, which is an assessment of the comparative safety performance of metal and oxide fuels during accidents in a 3500-MW (thermal), pool-type, liquid-metal-cooled reactor (LMR) is performed. The study focuses on three accident initiators with failure to scram: the unprotected loss-of-flow (ULOF), the unprotected transient overpower, and the unprotected loss-of-heat-sink (ULOHS). Core designs with a similar power output that have been previously analyzed in Europe under ULOF accident conditions are also included in this comparison. Emphasis is placed on identification of design features that provide passive, self-limiting responses to postulated accident conditions and quantification of relative safety margins. The analyses show that in ULOF and ULOHS sequences, metal-fueled LMRs with pool-type primary systems provide larger temperature margins to coolant boiling than do oxide-fueled reactors of the same design.

  4. Performance of metal and oxide fuels during accidents in a large liquid metal cooled reactor

    SciTech Connect

    Cahalan, J.; Wigeland, R. ); Friedel, G. , Bergisch Gladbach ); Kussmaul, G.; Royl, P. ); Moreau, J. ); Perks, M.

    1990-01-01

    In a cooperative effort among European and US analysts, an assessment of the comparative safety performance of metal and oxide fuels during accidents in a large (3500 MWt), pool-type, liquid-metal-cooled reactor (LMR) was performed. The study focused on three accident initiators with failure to scram: the unprotected loss-of-flow (ULOF), the unprotected transient overpower (UTOP), and the unprotected loss-of-heat-sink (ULOHS). Emphasis was placed on identification of design features that provide passive, self-limiting responses to upset conditions, and quantification of relative safety margins. The analyses show that in ULOF and ULOHS sequences, metal-fueled LMRs with pool-type primary systems provide larger temperature margins to coolant boiling than oxide-fueled reactors of the same design. 3 refs., 4 figs.

  5. An analysis of grazing incidence metal mirrors in a laser ICF reactor driver

    SciTech Connect

    Bieri, R.; Guinan, M.

    1991-07-12

    Grazing incidence metal mirrors (GIMMs) are examined to replace dielectric mirrors for the final elements in a laser beam line for an inertial confinement fusion reactor. For a laser driver with a wavelength from 250 to 500 nm in a 10-ms pulse, irradiated mirrors made of Al, Al alloys, or Mg were found to have calculated laser damage limits of 0.3--2.3 J/cm{sup 2} of beam energy and neutron lifetime fluence limits of over 5 {times} 10{sup 20} 14 MeV n/cm{sup 2} when used at grazing incidence and operated at room temperature or at 77 K. A final focusing system including mirrors made of Al alloy 7475 at room temperature or at liquid nitrogen temperatures used with a driver which delivers 5 MJ of beam energy in 32 beams would require 32 mirrors of roughly 10 m{sup 2} each. This chapter includes calculations of damage limits for GIMMs and discusses critical issues relevant to the integrity and lifetime of such mirrors in a reactor environment. The reflectivities of various metals are calculated from measured optical constants at room temperature and at cryogenic temperatures for 250- to 500-nm light at both normal and grazing incidence. Then, for the mirrors in a representative system, the thermal absorption and conduction rates of the best candidate metals are used with the maximum allowable cyclic thermal stress to give the maximum allowed surface-temperature rise and surface thermal load. The allowed surface thermal load and surface reflectivity give the maximum beam energy density and the minimum size for each mirror. For mirrors made of aluminum alloy 7475 and initially operated at room temperature, the resulting optical damage threshold and allowable temperature rise give a required mirror size for each final mirror. Critical issues relevant to the integrity and lifetime of such mirrors in a reactor environment are briefly discussed.

  6. Proposed pyrometallurgical process for rapid recycle of discharged fuel materials from the integral fast reactor. [Metal fuel

    SciTech Connect

    Burris, L.; Steindler, M.; Miller, W.

    1984-01-01

    The pool-type Integral Fast Reactor (IFR) concept developed by Argonne National Laboratory includes on-site recycle of discharged core and blanket fuel materials. The process and fabrication steps will be demonstrated in the EBR-II Fuel Cycle Facility with IFR fuel irradiated in EBR-II and the Fast Flux Test Facility. The proposed process consists of two major steps: a halide slagging step and an electrorefining step. The fuel is maintained in the metallic form to yield directly a metal product sufficiently decontaminated to allow recycle to the reactor as new fuel. The process is further described and available information to support its feasibility is presented.

  7. A US perspective on fast reactor fuel fabrication technology and experience part I: metal fuels and assembly design

    NASA Astrophysics Data System (ADS)

    Burkes, Douglas E.; Fielding, Randall S.; Porter, Douglas L.; Crawford, Douglas C.; Meyer, Mitchell K.

    2009-06-01

    This paper is part I of a review focusing on the United States experience with metallic fast reactor fuel fabrication and assembly design for the Experimental Breeder Reactor-II (EBR-II) and the Fast Flux Test Facility (FFTF). Experience with metal fuel fabrication in the United States is extensive, including over 60 years of research conducted by the government, national laboratories, industry, and academia. This experience has culminated in a considerable amount of research that resulted in significant improvements to the technologies employed to fabricate metallic fast reactor fuel. This part of the review documents the current state of fuel fabrication technologies for metallic fuels, some of the challenges faced by previous researchers, and how these were overcome. Knowledge gained from reviewing previous investigations will aid both researchers and policy makers in forming future decisions relating to nuclear fuel fabrication technologies.

  8. Driver Education Saves Gas.

    ERIC Educational Resources Information Center

    American Automobile Association, Falls Church, VA. Traffic Engineering and Safety Dept.

    The argument that driver education should be dropped because driver education cars use gas is shortsighted. High school driver education is an excellent vehicle for teaching concepts of energy conservation. A small investment in fuel now can result in major savings of gasoline over a student's lifetime. In addition good driver education courses…

  9. Method for producing hydrocarbon fuels and fuel gas from heavy polynuclear hydrocarbons by the use of molten metal halide catalysts

    DOEpatents

    Gorin, Everett

    1979-01-01

    In a process for hydrocracking heavy polynuclear carbonaceous feedstocks to produce lighter hydrocarbon fuels by contacting the heavy feedstocks with hydrogen in the presence of a molten metal halide catalyst in a hydrocracking zone, thereafter separating at least a major portion of the lighter hydrocarbon fuels from the spent molten metal halide and thereafter regenerating the spent molten metal halide by incinerating the spent molten metal halide by combustion of carbon and sulfur compounds in the spent molten metal halide in an incineration zone, the improvement comprising: (a) contacting the heavy feedstocks and hydrogen in the presence of the molten metal halide in the hydrocracking zone at reaction conditions effective to convert from about 60 to about 90 weight percent of the feedstock to lighter hydrocarbon fuels; (b) separating at least a major portion of the lighter hydrocarbon fuels from the spent molten metal halide; (c) contacting the spent molten metal halide with oxygen in a liquid phase gasification zone at a temperature and pressure sufficient to vaporize from about 25 to about 75 weight percent of the spent metal halide, the oxygen being introduced in an amount sufficient to remove from about 60 to about 90 weight percent of the carbon contained in the spent molten metal halide to produce a fuel gas and regenerated metal halide; and (d) incinerating the spent molten metal halide by combusting carbon and sulfur compounds contained therein.

  10. High performance, high durability non-precious metal fuel cell catalysts

    DOEpatents

    Wood, Thomas E.; Atanasoski, Radoslav; Schmoeckel, Alison K.

    2016-03-15

    This invention relates to non-precious metal fuel cell cathode catalysts, fuel cells that contain these catalysts, and methods of making the same. The fuel cell cathode catalysts are highly nitrogenated carbon materials that can contain a transition metal. The highly nitrogenated carbon materials can be supported on a nanoparticle substrate.

  11. Batch Tests with unirradiated uranium metal fuel program report.

    SciTech Connect

    Kaminski, M. D.

    2002-02-21

    Although the general environment of the proposed repository at Yucca Mountain is expected to be oxidizing in nature, the local chemistry within fuel canisters may be otherwise. The combination of low dissolved oxygen and corrosion of metallic fuels, such as Hanford's N-Reactor inventory, may produce reducing conditions. This condition may persist for periods sufficient to affect the corrosion and paragenesis of fuels and their reaction products. Starting in September 2001, unirradiated metallic uranium fuel was examined during batch tests under anoxic conditions. A series of tests carried out under inert atmosphere highlighted the rapid corrosion of the metallic uranium in EJ-13 water at 90 C. During the oxidation of the uranium, uranium dioxide fines spilled from the fuel surface generating copious amounts of colloids. The proportion of uranium-associated colloids accounted for nearly 50% to >99% of the uranium in solution after a brief period where no colloids were detected. The colloids were identified as individual (<10nm) and agglomerated uranium dioxide spheres as large as a few hundred nanometers in size. Silicate and alumino-silicate clays of diverse size and shape were also identified. The bulk size distribution as measured by dynamic light scattering was consistent with the microscopy observations in that the polydispersity indices were large, indicating a wide distribution of colloid particle sizes. The colloids were found to persist for periods beyond the scope of these tests and are at least partly stable. The anoxic experiments suggest that at least two mechanisms are responsible for uranium corrosion. The initial corrosion period is variably long but may last more than one month during which there is no net release of gas. Calculations of oxygen concentration in the vessel at the time of vessel closure show that this period is not consistent with the presence of dissolved oxygen, which would suppress H{sub 2} production in undersaturated conditions

  12. Experimental Determination of Metal Fuel Point Defect Parameters

    SciTech Connect

    Fluss, M J; McCall, S

    2008-06-03

    Nuclear metallic fuels are one of many options for advanced nuclear fuel cycles because they provide dimensional stability, mechanical integrity, thermal efficiency, and irradiation resistance while the associated pyro-processing is technically relevant to concerns about proliferation and diversion of special nuclear materials. In this presentation we will discuss recent success that we have had in studying isochronal annealing of damage cascades in Pu and Pu(Ga) arising from the self-decay of Pu as well as the annealing characteristics of noninteracting point defect populations produced by ion accelerator irradiation. Comparisons of the annealing properties of these two populations of defects arising from very different source terms are enlightening and point to complex defect and mass transport properties in the plutonium specimens which we are only now starting to understand as a result of many follow-on studies. More importantly however, the success of these measurements points the way to obtaining important mass transport parameters for comparison with theoretical predictions or to use directly in existing and future materials modeling of radiation effects in nuclear metallic fuels. The way forward on such measurements and the requisite theory and modeling will be discussed.

  13. Effect of a metal alloy fuel catalyst on bacterial growth.

    PubMed

    Ghosh, Ruma; Koerting, Claudia; Suib, Steven L; Best, Michael H; Berlin, Alvin J

    2005-11-08

    Many microorganisms have been demonstrated to utilize petroleum fuel products to fulfill their nutritional requirement for carbon. As a result, the ability of these microbes to degrade fuel has both a deleterious affect as well as beneficial applications. This study focused on the undesired ability of bacteria to grow on fuel and the potential for some metal alloys to inhibit this biodegradation. The objective of this study was to review the pattern of growth of two reference strains of petroleum-degrading bacteria, Pseudomonas oleovorans and Rhodococcus rhodocrous, in a specific hydrocarbon environment in the presence of a commercially available alloy. The alloy formulated and supplied by Advanced Power Systems International Inc. (APSI) is sold for fuel reformulation and other purposes. The components of the alloy used in the study were antimony, tin, lead, and mercury formulated as pellets. Surface characterization also showed the presence of tin oxide and lead amalgam phases. Hydrocarbon used for the study was primarily 87-octane gasoline. The growth of the bacteria in the water and mineral-supplemented gasoline mixture over 6-8 weeks was monitored by the viable plate count method. While an initial increase in bacteria occurred in the first week, overall bacterial growth was found to be suppressed in the presence of the alloy. Results also indicate that the alloy surface characteristics that convey the catalytic activity may also contribute to the observed antibacterial activity.

  14. DOE/NEAMS AMP CAMP I 2010 - multi species transport in metal fuels

    SciTech Connect

    Dilts, Gary A

    2011-01-21

    Essential aspects from the literature of metal nuclear fuel alloys and modeling the transport of constituents therein are discussed. The essential mathematical problem is described along with relevant issues for implementation of solution algorithms in the AMP nuclear fuel code.

  15. Synthesis of metal-polymer nanocomposites for fuel applications

    NASA Astrophysics Data System (ADS)

    Pontes Lima, Ricardo Jose

    Metal particles have long been of interest as fuel and fuel additives for propellants and explosives because their high-density energy. In general, their volumetric energy density is higher as compared to conventional hydrocarbon-based fuel. This advantage is clearly beneficial for volume-limited rocket propulsion systems, in which the most important parameter is the density-based specific impulse. It is widely known that the reactivity of metal particles increases when particle size decreases. Significant improvements in combustion behaviors of propellant have been attributed to the use of nanosize metal particles, for example faster burning rates and shorter ignition delay time. For this reason the application of nanosize particles as fuel could be preferable than large particles. However, several difficulties limit the use of ultrafine particles in fuel applications and propellants. Most of them are attributed to the oxide layer formation on the particles that prevents good combustion performance. In boron applications, practical difficulties such as poor ignition and combustion performance, have so far limited extensive use of boron for fuel applications. Indications are that application of non-oxide coatings on particles protects them against premature oxidation and enhances their combustion properties. A number of methods have been proposed to coat metal particles with a variety of organic compounds or other metals. Common applications provides coatings of saturated hydrocarbons or fatty acids, such as oleic acid as a means to passivation the particles. Recently, high-energy ball milling, in combination with chemical reactions, was applied to fabricate nanostructured metal particles coated with organic compounds. One of the advantages of this technique is that the passivation be integrated into the production of particles as a single step. For example, the reactive milling of boron in oleic acid solution showed an improved reactivity of as-milled powders

  16. Metallic impurities-silicon carbide interaction in HTGR fuel particles

    NASA Astrophysics Data System (ADS)

    Minato, Kazuo; Ogawa, Toru; Kashimura, Satoru; Fukuda, Kousaku; Shimizu, Michio; Tayama, Yoshinobu; Takahashi, Ishio

    1990-12-01

    Corrosion of the coating layers of silicon carbide (SiC) by metallic impurities was observed in irradiated Triso-coated uranium dioxide particles for high temperature gas-cooled reactors with an optical microscope and an electron probe micro-analyzer. The SiC layers were attacked from the outside of the particles. The main element observed in the corroded areas was iron, but sometimes iron and nickel were found. These elements must have been contained as impurities in the graphite matrix in which the coated particles were dispersed. Since these elements are more stable thermodynamically in the presence of SiC than in the presence of graphite at irradiation temperatures, they were transferred to the SiC layer to form more stable silicides. During fuel manufacturing processes, intensive care should be taken to prevent the fuel from being contaminated with those elements which react with SiC.

  17. Perspectives on the metallic interconnects for solid oxide fuel cells.

    PubMed

    Zhu, Wei-Zhong; Yan, Mi

    2004-12-01

    The various stages and progress in the development of interconnect materials for solid oxide fuel cells (SOFCs) over the last two decades are reviewed. The criteria for the application of materials as interconnects are highlighted. In-terconnects based on lanthanum chromite ceramics demonstrate many inherent drawbacks and therefore are only useful for SOFCs operating around 1000 degrees C. The advance in the research of anode-supported flat SOFCs facilitates the replacement of ceramic interconnects with metallic ones due to their significantly lowered working temperature. Besides, interconnects made of metals or alloys offer many advantages as compared to their ceramic counterpart. The oxidation response and thermal expansion behaviors of various prospective metallic interconnects are examined and evaluated. The minimization of contact resistance to achieve desired and reliable stack performance during their projected lifetime still remains a highly challenging issue with metallic interconnects. Inexpensive coating materials and techniques may play a key role in pro-moting the commercialization of SOFC stack whose interconnects are constructed of some current commercially available alloys. Alternatively, development of new metallic materials that are capable of forming stable oxide scales with sluggish growth rate and sufficient electrical conductivity is called for.

  18. A precious-metal free micro fuel cell accumulator

    NASA Astrophysics Data System (ADS)

    Bretthauer, C.; Müller, C.; Reinecke, H.

    2011-05-01

    In recent years, integrated fuel cell (FC) type primary and secondary batteries attracted a great deal of attention as integrated on-chip power sources due to their high theoretical power densities. Unfortunately, the costs of these devices have been rather high. This is partially due to the involved clean-room processes, but also due to the fact that these devices generally rely on expensive precious-metals such as Pd and Pt. Therefore we developed a novel integrated FC type accumulator that is based on non-precious-metals only. The key component of the presented accumulator is its alkaline polymer electrolyte membrane that allows not only the usage of a low-cost AB5 type hydrogen storage electrode, but also the usage of La0.6Ca0.4CoO3 as a precious-metal free bifunctional catalyst for the air-breathing electrode. Additionally the presented design requires only comparatively few cleanroom processes which further reduces the overall production costs. Although abdicating precious-metals, the presented accumulator shows an open circuit voltage of 0.81 V and a maximum power density of 0.66 mW cm-2 which is comparable or even superior to former precious-metal based cells.

  19. Nuclear fuel for liquid metal cooled nuclear reactors

    SciTech Connect

    Duncombe, E.; Adamson, J.; Gratton, C.P.

    1983-11-22

    In a cluster of nuclear fuel rods cooled by liquid metal an obstruction to coolant flow results in overheating in the wake of the obstruction. By the provision of open ended heat transfer tubes in the flow channels, a guaranteed supply of coolant is maintained and this supply holds the temperature to below saturation. Heat transfer via the tubes is highly efficient and ensures that a sufficient temperature rise occurs at the cluster exit to provoke a response from the outlet temperature transducer sensing average temperature.

  20. Fully-Coupled Metallic Fuel Performance Simulations using BISON

    SciTech Connect

    Galloway, Jack D.; Unal, Cetin

    2015-08-27

    This document is a set of slides intended to accompany a talk at a meeting. The first topic taken up is zirconium redistribution. The rod edge Zr increase is evidently due to the Soret term and temperature gradient. Then metallic fission gas release modeling is considered. Based on a GRSIS/FEAST model, the approach of generating fission gas in the fuel matrix is described. A sensitivity study on parameters is presented, including sodium bond & diffusion coefficient sensitivity along with dt sensitivity. Finally, results of some coupled simulations are shown, with ideas about future work.

  1. Metallography and fuel cladding chemical interaction in fast flux test facility irradiated metallic U-10Zr MFF-3 and MFF-5 fuel pins

    SciTech Connect

    Carmack, W. J.; Chichester, H. M.; Porter, D. L.; Wootan, D. W.

    2016-05-01

    Abstract The Mechanistic Fuel Failure (MFF) series of metal fuel irradiations conducted in the Fast Flux Test Facility (FFTF) provides an important potential comparison between data generated in the Experimental Breeder Reactor (EBR-II) and that expected in a larger-scale fast reactor. The irradiations were the beginning tests to qualify U-10wt%Zr as a driver fuel for FFTF. The FFTF core, with a 91.4 cm tall fuel column and a chopped cosine neutron flux profile, operated with a peak cladding temperature at the top of the fuel column, but developed peak burnup at the centerline of the core. This places the peak fuel temperature midway between the core center and the top of fuel, lower in the fuel column than in previous EBR-II experiments that had a 32-cm height core. The MFF-3 and MFF-5 qualification assemblies operated in FFTF to >10 at% burnup, and performed very well with no cladding breaches. The MFF-3 assembly operated to 13.8 at% burnup with a peak inner cladding temperature of 643°C, and the MFF-5 assembly operated to 10.1 at% burnup with a peak inner cladding temperature of 651°C. Because of the very high operating temperatures for both the fuel and the cladding, data from the MFF assemblies are most comparable to the data obtained from the EBR-II X447 experiment, which experienced two pin breaches. The X447 breaches were strongly influenced by a large amount of fuel/cladding chemical interaction (FCCI). The MFF pins benefitted from different axial locations of high burnup and peak cladding temperature, which helped to reduce interdiffusion between rare earth fission products and stainless steel cladding. Post-irradiation examination evidence illustrates this advantage. Comparing other performance data of the long MFF pins to prior EBR-II test data, the MFF fuel inside the cladding grew less axially, and the gas release data did not reveal a definitive difference.

  2. Metallography and fuel cladding chemical interaction in fast flux test facility irradiated metallic U-10Zr MFF-3 and MFF-5 fuel pins

    DOE PAGES

    Carmack, W. Jon; Chichester, Heather M.; Porter, Douglas L.; ...

    2016-02-27

    The Mechanistic Fuel Failure (MFF) series of metal fuel irradiations conducted in the Fast Flux Test Facility (FFTF) provides an important potential comparison between data generated in the Experimental Breeder Reactor (EBR-II) and that expected in a larger-scale fast reactor. The irradiations were the beginning tests to qualify U-10wt%Zr as a driver fuel for FFTF. The FFTF core, with a 91.4 cm tall fuel column and a chopped cosine neutron flux profile, operated with a peak cladding temperature at the top of the fuel column, but developed peak burnup at the centerline of the core. This then places the peakmore » fuel temperature midway between the core center and the top of fuel, lower in the fuel column than in previous EBR-II experiments that had a 32-cm height core. The MFF-3 and MFF-5 qualification assemblies operated in FFTF to >10 at% burnup, and performed very well with no cladding breaches. The MFF-3 assembly operated to 13.8 at% burnup with a peak inner cladding temperature of 643°C, and the MFF-5 assembly operated to 10.1 at% burnup with a peak inner cladding temperature of 651°C. Because of the very high operating temperatures for both the fuel and the cladding, data from the MFF assemblies are most comparable to the data obtained from the EBR-II X447 experiment, which experienced two pin breaches. The X447 breaches were strongly influenced by a large amount of fuel/cladding chemical interaction (FCCI). The MFF pins benefitted from different axial locations of high burnup and peak cladding temperature, which helped to reduce interdiffusion between rare earth fission products and stainless steel cladding. Post-irradiation examination evidence illustrates this advantage. After comparing other performance data of the long MFF pins to prior EBR-II test data, the MFF fuel inside the cladding grew less axially, and the gas release data did not reveal a definitive difference.« less

  3. Metallography and fuel cladding chemical interaction in fast flux test facility irradiated metallic U-10Zr MFF-3 and MFF-5 fuel pins

    SciTech Connect

    Carmack, W. Jon; Chichester, Heather M.; Porter, Douglas L.; Wootan, David W.

    2016-02-27

    The Mechanistic Fuel Failure (MFF) series of metal fuel irradiations conducted in the Fast Flux Test Facility (FFTF) provides an important potential comparison between data generated in the Experimental Breeder Reactor (EBR-II) and that expected in a larger-scale fast reactor. The irradiations were the beginning tests to qualify U-10wt%Zr as a driver fuel for FFTF. The FFTF core, with a 91.4 cm tall fuel column and a chopped cosine neutron flux profile, operated with a peak cladding temperature at the top of the fuel column, but developed peak burnup at the centerline of the core. This then places the peak fuel temperature midway between the core center and the top of fuel, lower in the fuel column than in previous EBR-II experiments that had a 32-cm height core. The MFF-3 and MFF-5 qualification assemblies operated in FFTF to >10 at% burnup, and performed very well with no cladding breaches. The MFF-3 assembly operated to 13.8 at% burnup with a peak inner cladding temperature of 643°C, and the MFF-5 assembly operated to 10.1 at% burnup with a peak inner cladding temperature of 651°C. Because of the very high operating temperatures for both the fuel and the cladding, data from the MFF assemblies are most comparable to the data obtained from the EBR-II X447 experiment, which experienced two pin breaches. The X447 breaches were strongly influenced by a large amount of fuel/cladding chemical interaction (FCCI). The MFF pins benefitted from different axial locations of high burnup and peak cladding temperature, which helped to reduce interdiffusion between rare earth fission products and stainless steel cladding. Post-irradiation examination evidence illustrates this advantage. After comparing other performance data of the long MFF pins to prior EBR-II test data, the MFF fuel inside the cladding grew less axially, and the gas release data did not reveal a definitive difference.

  4. Analysis of metal fuel transient overpower experiments with the SAS4A accident analysis code

    SciTech Connect

    Tentner, A.M.; Kalimullah; Miles, K.J.

    1990-01-01

    The results of the SAS4A analysis of the M7 TREAT Metal fuel experiment are presented. New models incorporated in the metal fuel version of SAS4A are described. The computational results are compared with the experimental observations and this comparison is used in the interpretation of physical phenomena. This analysis was performed using the integrated metal fuel SAS4A version and covers a wide range of events, providing an increased degree of confidence in the SAS4A metal fuel accident analysis capabilities.

  5. Eco-hydrological and climatic drivers of fuel moisture dynamics in complex terrain

    NASA Astrophysics Data System (ADS)

    Nyman, Petter; Duff, Thomas; Baillie, Craig; Sheridan, Gary

    2016-04-01

    Fuel moisture is a critical parameter for predicting fire behaviour and for planning prescribed burning operations. Moisture content in fuels located on or near the forest floor is particularly important because this fuel source 1) can comprise a large component of the overall fuel load, 2) can have a strong impact on fire spread, and 3) it can in many cases be effectively managed with prescribed burning. Being able to predict surface fuel moisture content is therefore an important research topic. Moisture dynamics in surface fuel are a function of microclimate above the litter layer, rainfall, interception, soil moisture and the hydraulic properties of the fuel itself. Process-based fuel moisture models include these factors in their predictions. However, the data needed to parametrise and test such models at landscape scales are often lacking. The relative importance of various components of the water balance in the litter layer is therefore unknown. In this research we seek to quantify how climate, vegetation and eco-hydrological feedback contribute to variation in net radiation and potential evaporation at the forest floor. Research sites were established at 16 locations in eucalyptus forests in south-east Australia with variable elevation, solar exposure, and drainage areas. Forests ranged from open woodland to tall temperate forests. At these sites we measured solar radiation, air temperature, relative humidity, throughfall, litter moisture, soil moisture, and litter temperature. Forest structure was characterised using hemispherical photos. Using these data on microclimate and vegetation structure we develop and parametrise a Penman-Monteith model of potential evaporation on the forest floor at daily timescales. Using this model of potential evaporation alongside landscape-scale information on the long term water and energy balance we quantify the effects of topography, long-term climate and eco-hydrological feedback on the energy and water balance at the

  6. Assessment of fission-gas-induced transient swelling in metallic fuel

    SciTech Connect

    Sevy, R H; Cahalan, J E

    1985-03-01

    A model for fission-gas-induced transient swelling in metallic fuel is described. An observation that the strength of metallic fuel becomes very small at a temperature several hundred degrees below the solidus forms the basis for an assumption that, above this temperature, the fuel proceeds through a series of stress-free equilibrium states for a large range of heating rates. Gas bubble coalescence and growth and any effects from ingested sodium are ignored such that the model may tend to underestimate swelling in some circumstances. The fuel swelling model is used to predict the reactivity effect of fission-gas-induced axial expansion of metallic fuel during transient overpower excursions. Comparisons to oxide fuel behavior are made. Sensitivity of results to metallic fuel modeling assumptions are assessed in a parametric study.

  7. Molten metal electrodes in solid oxide fuel cells

    NASA Astrophysics Data System (ADS)

    Javadekar, Ashay Dileep

    Molten metal electrodes in solid oxide fuel cells are electrochemically characterized for their possible use in direct carbon oxidation and energy storage. The cells were operated in the battery mode at 973 K, without added fuel, in order to understand the oxidation characteristics of Sb alloys as anodes at electrolyte interfaces. The cells using 50-mol% In-Sb and Sn-Sb mixtures exhibited open-circuit voltages (OCV) of 1.0 and 0.93 V, values similar to those of cells with pure In and Sn anodes respectively, and insulating In2O3 and SnO2 layers formed at the electrolyte interface. The 50-mol% Sb-Bi cell had an OCV of 0.73 V initially, close to that with pure Sb anode. The OCV remained constant until all of the Sb had been oxidized, after which it dropped to 0.43 V, similar to the value for pure Bi. SEM analysis of the spent cell showed two distinct phases, with metallic Bi at the bottom and Sb2O3 at the top. The cell with 50-mol% Sb-Pb anode exhibited an OCV that changed continuously with conversion, from 0.73 V initially to 0.67 V following the addition of charge equivalent to oxidation of 120% the Sb. The total cell impedance remained low for this entire period. EDS measurements on the sectioned Sb-Pb cell suggested formation of a mixed oxide of Pb and Sb. An energy-storage concept using molten Sb as the fuel in a reversible solid-oxide electrochemical cell was tested using a button cell with a Sc-stabilized zirconia electrolyte at 973 K, by measuring the impedances under fuel-cell and electrolyzer conditions for a range of stirred Sb-Sb2O 3 compositions. The Sb-Sb2O3 electrode impedances were found to be on the order of 0.15 ohm.cm2 for both fuel-cell and electrolyzer conditions, for compositions up to 30% Sb and 70% Sb2O3. The OCVs were 0.75 V, independent of conversion. The use of molten neat Ag and alloyed Ag-Sb for direct-carbon anodes in SOFCs has been examined at 1273 K. For Ag, an OCV typical of that expected for carbon oxidation, 1.12 V, was observed when

  8. The evaluation of the use of metal alloy fuels in pressurized water reactors. Final report

    SciTech Connect

    Lancaster, D.

    1992-10-26

    The use of metal alloy fuels in a PWR was investigated. It was found that it would be feasible and competitive to design PWRs with metal alloy fuels but that there seemed to be no significant benefits. The new technology would carry with it added economic uncertainty and since no large benefits were found it was determined that metal alloy fuels are not recommended. Initially, a benefit was found for metal alloy fuels but when the oxide core was equally optimized the benefit faded. On review of the optimization of the current generation of ``advanced reactors,`` it became clear that reactor design optimization has been under emphasized. Current ``advanced reactors`` are severely constrained. The AP-600 required the use of a fuel design from the 1970`s. In order to find the best metal alloy fuel design, core optimization became a central effort. This work is ongoing.

  9. A Review of Inherent Safety Characteristics of Metal-Alloy SFR Fuel Against Postulated Accidents

    SciTech Connect

    Sofu, Tanju

    2015-04-01

    The thermal, mechanical, and neutronic performance of the metal alloy fast reactor fuel design complements the safety advantages of the liquid metal cooling and the pool-type primary system. Together, these features provide large safety margins in both normal operating modes and for a wide range of postulated accidents. In particular, they maximize the measures of safety associated with inherent reactor response to unprotected, double-fault accidents, and to minimize risk to the public and plant investment. High thermal conductivity and high gap conductance play the most significant role in safety advantages of the metallic fuel, resulting in a flatter radial temperature profile within the pin and much lower normal operation and transient temperatures in comparison to oxide fuel. Despite the big difference in melting point, both oxide and metal fuels have a relatively similar margin to melting during postulated accidents. When the metal fuel cladding fails, it typically occurs below the coolant boiling point and the damaged fuel pins remain cool-able. Metal fuel is compatible with sodium coolant, eliminating the potential of energetic fuel coolant reactions and flow blockages. All these, and the low retained heat leading to a longer grace period for operator action, are significant contributing factors to the inherently benign response of metallic fuel to postulated accidents. This paper summarizes the past analytical and experimental results obtained in past sodium-cooled fast reactor safety programs in the United States, and presents an overview of fuel safety performance as observed in laboratory and in-pile tests.

  10. Consequences of metallic fuel-cladding liquid phase attack during over-temperature transient on fuel element lifetime

    SciTech Connect

    Lahm, C.E.; Koenig, J.F.; Seidel, B.R.

    1990-01-01

    Metallic fuel elements irradiated in EBR-II at temperatures significantly higher than design, causing liquid phase attack of the cladding, were subsequently irradiated at normal operating temperatures to first breach. The fuel element lifetime was compared to that for elements not subjected to the over-temperature transient and found to be equivalent. 1 ref., 3 figs.

  11. Epsilon Metal Waste Form for Immobilization of Noble Metals from Used Nuclear Fuel

    SciTech Connect

    Crum, Jarrod V.; Strachan, Denis M.; Rohatgi, Aashish; Zumhoff, Mac R.

    2013-10-01

    Epsilon metal (ε-metal), an alloy of Mo, Pd, Rh, Ru, and Tc, is being developed as a waste form to treat and immobilize the undissolved solids and dissolved noble metals from aqueous reprocessing of commercial used nuclear fuel. Epsilon metal is an attractive waste form for several reasons: increased durability relative to borosilicate glass, it can be fabricated without additives (100% waste loading), and in addition it also benefits borosilicate glass waste loading by eliminating noble metals from the glass and thus the processing problems related there insolubility in glass. This work focused on the processing aspects of the epsilon metal waste form development. Epsilon metal is comprised of refractory metals resulting in high reaction temperatures to form the alloy, expected to be 1500 - 2000°C making it a non-trivial phase to fabricate by traditional methods. Three commercially available advanced technologies were identified: spark-plasma sintering, microwave sintering, and hot isostatic pressing, and investigated as potential methods to fabricate this waste form. Results of these investigations are reported and compared in terms of bulk density, phase assemblage (X-ray diffraction and elemental analysis), and microstructure (scanning electron microscopy).

  12. Epsilon metal waste form for immobilization of noble metals from used nuclear fuel

    NASA Astrophysics Data System (ADS)

    Crum, Jarrod V.; Strachan, Denis; Rohatgi, Aashish; Zumhoff, Mac

    2013-10-01

    Epsilon metal (ɛ-metal), an alloy of Mo, Pd, Rh, Ru, and Tc, is being developed as a waste form to treat and immobilize the undissolved solids and dissolved noble metals from aqueous reprocessing of commercial used nuclear fuel. Epsilon metal is an attractive waste form for several reasons: increased durability relative to borosilicate glass, it can be fabricated without additives (100% waste loading), and in addition it also benefits borosilicate glass waste loading by eliminating noble metals from the glass, thus the processing problems related to their insolubility in glass. This work focused on the processing aspects of the epsilon metal waste form development. Epsilon metal is comprised of refractory metals resulting in high alloying temperatures, expected to be 1500-2000 °C, making it a non-trivial phase to fabricate by traditional methods. Three commercially available advanced technologies were identified: spark-plasma sintering, microwave sintering, and hot isostatic pressing, and investigated as potential methods to fabricate this waste form. Results of these investigations are reported and compared in terms of bulk density, phase assemblage (X-ray diffraction and elemental analysis), and microstructure (scanning electron microscopy).

  13. Casting technology for manufacturing metal rods from simulated metallic spent fuels

    NASA Astrophysics Data System (ADS)

    Leeand, Y. S.; Lee, D. B.; Kim, C. K.; Shin, Y. J.; Lee, J. H.

    2000-09-01

    A uranium metal rod 13.5 mm in diameter and 1,150 mm long was produced from simulated metallic spent fuels with advanced casting equipment using the directional-solidification method. A vacuum casting furnace equipped with a four-zone heater to prevent surface oxidation and the formation of surface shrinkage holes was designed. By controlling the axial temperature gradient of the casting furnace, deformation by the surface shrinkage phenomena was diminished, and a sound rod was manufactured. The cooling behavior of the molten uranium was analyzed using the computer software package MAGMAsoft.

  14. Irradiaton of Metallic and Oxide Fuels for Actinide Transmutation in the ATR

    SciTech Connect

    Heather J. MacLean; Steven L. Hayes

    2007-09-01

    Metallic fuels containing minor actinides and rare earth additions have been fabricated and are prepared for irradiation in the ATR, scheduled to begin during the summer of 2007. Oxide fuels containing minor actinides are being fabricated and will be ready for irradiation in ATR, scheduled to begin during the summer of 2008. Fabrication and irradiation of these fuels will provide detailed studies of actinide transmutation in support of the Global Nuclear Energy Partnership. These fuel irradiations include new fuel compositions that have never before been tested. Results from these tests will provide fundamental data on fuel irradiation performance and will advance the state of knowledge for transmutation fuels.

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

    PubMed

    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.

  16. Physics implications of oxide and metal fuel on the design of small LMFBR cores

    SciTech Connect

    Orechwa, Y.; Khalil, H.

    1984-09-17

    Slower growth projections in the demand for electricity and advances in metal fuel technology have shifted some of the emphasis in fast reactor development in the US from large oxide cores to small cores and also renewed interest in metal fuel. Cores constrained by diameter and fuel burnup exhibit many similar neutronic performance characteristics. However, some parameters such as reactivity coefficients, for example, are very different. The physics parameters of the four cores studied suggest that metal fueled cores, although less developed than oxide cores, are more flexible in adapting to currently changing deployment scenarios.

  17. Development of inexpensive metal macrocyclic complexes for use in fuel cells

    SciTech Connect

    Doddapaneni, N.; Ingersoll, D.; Kosek, J.A.; Cropley, C.C.; Hamdan, M.

    1998-01-01

    Several metal macrocyclic complexes were synthesized for use as catalysts in fuel cells. An initial evaluation of their ability to catalyze the fuel cell reactions were completed. Based on this initial evaluation, one metal macrocyclic catalyst was selected and long-term stability testing in a fuel cell was initiated. The fuel cell employing this catalyst was operated continuously for one year with little signs of catalyst degradation. The effect of synthetic reformates on the performance of the catalyst in the fuel cell environment also demonstrated high tolerance of this catalyst for common contaminants and poisons.

  18. N-Reactor (U-metal) Fuel Characteristics for Disposal Criticality Analysis

    SciTech Connect

    Taylor, Larry Lorin

    2000-05-01

    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 nine 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. Additionally, the criticality analysis will also require data to support design of the canister internals, thermal, and radiation shielding. The purpose of this report is to consolidate and provide in a concise format, material and information/data needed to perform supporting analyses to qualify N-Reactor fuels for acceptance into the designated repository. The N Reactor fuels incorporate zirconium cladding and uranium metal with unique fabrication details in terms of physical size, and method of construction. The fuel construction and post-irradiation handling have created attendant issues relative to cladding failure in the underwater storage environment. These fuels were comprised of low-enriched metal (0.947 to 1.25 wt% 235U) that were originally intended to generate weapons-grade plutonium for national defense. Modifications in subsequent fuel design and changes in the mode of reactor operation in later years were focused more toward power production.

  19. Using graphitic foam as the bonding material in metal fuel pins for sodium fast reactors

    NASA Astrophysics Data System (ADS)

    Karahan, Aydın; Kazimi, Mujid S.

    2013-10-01

    The study evaluates the possible use of graphite foam as the bonding material between U-Pu-Zr metallic fuel and steel clad for sodium fast reactor applications using FEAST-METAL fuel performance code. Furthermore, the applicability of FEAST-METAL to the advanced fuel designs is demonstrated. Replacing the sodium bond with a chemically stable foam material would eliminate fuel clad metallurgical interactions, and allow for fuel swelling under low external stress. Hence, a significant improvement is expected for the steady state and transient performance. FEAST-METAL was used to assess the thermo-mechanical behavior of the new fuel form and a reference metallic fuel pin. Nearly unity conversion ratio, 75% smear density U-15Pu-6Zr metallic fuel pin with sodium bond, and T91 cladding was selected as a reference case. It was found that operating the reference case at high clad temperatures (600-660 °C) results in (1) excessive clad wastage formation/clad thinning due to lanthanide migration and formation of brittle phases at clad inner surface, and (2) excessive clad hoop strain at the upper axial section due mainly to the occurrence of thermal creep. The combination of these two factors may lead to cladding breach. The work concludes that replacing the sodium bond with 80% porous graphite foam and reducing the fuel smear density to 70%, it is likely that the fuel clad metallurgical interaction would be eliminated while the fuel swelling is allowed without excessive fuel clad mechanical interaction. The suggested design appears as an alternative for a high performance metallic fuel design for sodium fast reactors.

  20. Dynamics of axial extrusion of metallic fuel during overheating transients

    SciTech Connect

    Kramer, J M; Demaree, J D; Gruber, E E

    1985-12-01

    An analysis is presented for the axial extrusion of an expanding viscoelastic solid inside a long cylindrical tube. Both differential thermal expansion and expansion of gas bubbles in the solid are considered. Finite element calculations are used to illustrate the details of the behavior of the system. The response is shown to be initially elastic followed by the development of a boundary layer near the free surface where the pressure gradients are sufficiently large to cause axial viscous flow. Simple boundary layer equations are derived to describe this flow. Results using these equations agree well with the results of the finite element calculations. The theory is applied to the extrusion of uranium-based metallic reactor fuel during overheating transients. 10 figs.

  1. Mechanism of deposit formation on fuel-wetted metal surfaces

    SciTech Connect

    Stavinoha, L.L.; Westbrook, S.R.; McInnis, L.A.

    1995-05-01

    Experiments were performed in a Single-Tube Heat Exchanger (STHE) apparatus and a Hot Liquid Process Simulator (HLPS) configured and operated to meet Jet Fuel Thermal Oxidation Tester (JFTOT) ASTM D 3241 requirements. The HLPS-JFTOT heater tubes used were 1018 mild steel, 316 stainless steel (SS), 304 stainless steel (SS), and 304 SS tubes coated with aluminum, magnesium, gold, and copper. A low-sulfur Jet A fuel with a breakpoint temperature of 254{degrees}C was used to create deposits on the heater tubes at temperatures of 300{degrees}C, 340{degrees}C, and 380{degrees}C. Deposit thickness was measured by dielectric breakdown voltage and Auger ion milling. Pronounced differences between the deposit thickness measuring techniques suggested that both the Auger milling rate and the dielectric strength of the deposit may be affected by deposit morphology/composition (such as metal ions that may have become included in the bulk of the deposit). Carbon burnoff data were obtained as a means of judging the validity of DMD-derived deposit evaluations. ESCA data suggest that the thinnest deposit was on the magnesium-coated test tube. The Scanning Electron Microscope (SEM) photographs showed marked variations in the deposit morphology and the results suggested that surface composition has a significant effect on the mechanism of deposition. The most dramatic effect observed was that the bulk of deposits moved to tube locations of lower temperature as the maximum temperature of the tube was increased from 300{degrees} to 380{degrees}C, also verified in a single-tube heat exchanger. The results indicate that the deposition rate and quantity at elevated temperatures is not completely temperature dependent, but is limited by the concentration of dissolved oxygen and/or reactive components in the fuel over a temperature range.

  2. Laser dispersion and ignition of metal fuel particles.

    PubMed

    Abdel-Hafez, Ahmed A; Brodt, Matthew W; Carney, Joel R; Lightstone, James M

    2011-06-01

    The development of a laser-shock technique for dispersing Al metal fuel particles at velocities approaching those expected in a detonating explosive is discussed. The technique is described in detail by quantifying how air drag affects the temporal variation of the velocity of the dispersed particle plume. The effect of particle size is incorporated by examining various poly-dispersed commercial Al powders at different dispersion velocities (390-630 m/s). The technique is finally tested within a preliminary study of particle ignition delay and burn time, where the effect of velocity is highlighted for different particle sizes. It was found that plume velocity exhibits a modified exponential temporal profile, where smaller particles are more susceptible to air drag than larger ones. Moreover, larger particles exhibit longer ignition delays and burn times than smaller ones. The velocity of a particle was found to significantly affect its ignition delay, burn time, and combustion temperature, especially for particles in the diffusion-controlled regime. Shorter ignition delays and burn times and lower temperatures were observed at higher particle velocities. The utility of this technique as a combustion screening test for future, novel fuels is discussed.

  3. Ion-driver fast ignition: Reducing heavy-ion fusion driver energy and cost, simplifying chamber design, target fab, tritium fueling and power conversion

    SciTech Connect

    Logan, G.; Callahan-Miller, D.; Perkins, J.; Caporaso, G.; Tabak, M.; Moir, R.; Meier, W.; Bangerter, Roger; Lee, Ed

    1998-04-01

    Ion fast ignition, like laser fast ignition, can potentially reduce driver energy for high target gain by an order of magnitude, while reducing fuel capsule implosion velocity, convergence ratio, and required precisions in target fabrication and illumination symmetry, all of which should further improve and simplify IFE power plants. From fast-ignition target requirements, we determine requirements for ion beam acceleration, pulse-compression, and final focus for advanced accelerators that must be developed for much shorter pulses and higher voltage gradients than today's accelerators, to deliver the petawatt peak powers and small focal spots ({approx}100 {micro}m) required. Although such peak powers and small focal spots are available today with lasers, development of such advanced accelerators is motivated by the greater likely efficiency of deep ion penetration and deposition into pre-compressed 1000x liquid density DT cores. Ion ignitor beam parameters for acceleration, pulse compression, and final focus are estimated for two examples based on a Dielectric Wall Accelerator; (1) a small target with {rho}r {approx} 2 g/cm{sup 2} for a small demo/pilot plant producing {approx}40 MJ of fusion yield per target, and (2) a large target with {rho}r {approx} 10 g/cm{sup 2} producing {approx}1 GJ yield for multi-unit electricity/hydrogen plants, allowing internal T-breeding with low T/D ratios, >75 % of the total fusion yield captured for plasma direct conversion, and simple liquid-protected chambers with gravity clearing. Key enabling development needs for ion fast ignition are found to be (1) ''Close-coupled'' target designs for single-ended illumination of both compressor and ignitor beams; (2) Development of high gradient (>25 MV/m) linacs with high charge-state (q {approx} 26) ion sources for short ({approx}5 ns) accelerator output pulses; (3) Small mm-scale laser-driven plasma lens of {approx}10 MG fields to provide steep focusing angles close-in to the target

  4. Behavior of metallic fission products in uranium plutonium mixed oxide fuel

    NASA Astrophysics Data System (ADS)

    Sato, I.; Furuya, H.; Arima, T.; Idemitsu, K.; Yamamoto, K.

    1999-08-01

    Metallic fission products, ruthenium, rhodium, technetium, palladium, and molybdenum, exist in irradiated oxide fuels as metallic inclusions. In this work, the radial distributions of metallic inclusion constituents in the fuel specimen irradiated to a peak burnup of 7-13 at.% were observed with an electron probe microanalysis. Palladium concentration is high at the periphery in all the specimens. Molybdenum shows the same tendency for the 13 at.% burnup specimen. These results showed the significant difference between experimental data and calculations with ORIGEN-2 at such high burnups, which suggested that the migration of palladium and molybdenum was controlled mainly by diffusion of gaseous species containing each metal along the fuel temperature gradient.

  5. Report on FY16 Low-dose Metal Fuel Irradiation and PIE

    SciTech Connect

    Edmondson, Philip D.

    2016-09-01

    This report gives an overview of the efforts into the low-dose metal fuel irradiation and PIE as part of the Fuel Cycle Research & Development (FCRD) Advanced Fuels Campaign (AFC) milestone M3FT-16OR020303031. The current status of the FCT and FCRP irradiation campaigns are given including a description of the materials that have been irradiated, analysis of the passive temperature monitors, and the initial PIE efforts of the fuel samples.

  6. A metallic interconnect for a solid oxide fuel cell stack

    NASA Astrophysics Data System (ADS)

    England, Diane Mildred

    A solid oxide fuel cell (SOFC) electrochemically converts the chemical energy of reaction into electrical energy. The commercial success of planar, SOFC stack technology has a number of challenges, one of which is the interconnect that electrically and physically connects the cathode of one cell to the anode of an adjacent cell in the SOFC stack and in addition, separates the anodic and cathodic gases. An SOFC stack operating at intermediate temperatures, between 600°C and 800°C, can utilize a metallic alloy as an interconnect material. Since the interconnect of an SOFC stack must operate in both air and fuel environments, the oxidation kinetics, adherence and electronic resistance of the oxide scales formed on commercial alloys were investigated in air and wet hydrogen under thermal cycling conditions to 800°C. The alloy, Haynes 230, exhibited the slowest oxidation kinetics and the lowest area-specific resistance as a function of oxidation time of all the alloys in air at 800°C. However, the area-specific resistance of the oxide scale formed on Haynes 230 in wet hydrogen was unacceptably high after only 500 hours of oxidation, which was attributed to the high resistivity of Cr2O3 in a reducing atmosphere. A study of the electrical conductivity of the minor phase manganese chromite, MnXCr3-XO4, in the oxide scale of Haynes 230, revealed that a composition closer to Mn2CrO4 had significantly higher electrical conductivity than that closer to MnCr 2O4. Haynes 230 was coated with Mn to form a phase closer to the Mn2CrO4 composition for application on the fuel side of the interconnect. U.S. Patent No. 6,054,231 is pending. Although coating a metallic alloy is inexpensive, the stringent economic requirements of SOFC stack technology required an alloy without coating for production applications. As no commercially available alloy, among the 41 alloys investigated, performed to the specifications required, a new alloy was created and designated DME-A2. The oxide scale

  7. Approaches to mitigate metal catalyst deactivation in solid oxide fuel cell (SOFC) fuel electrodes

    NASA Astrophysics Data System (ADS)

    Adijanto, Lawrence

    While Ni/YSZ cermets have been used successfully in SOFCs, they also have several limitations, thus motivating the use of highly conductive ceramics to replace the Ni components in SOFC anodes. Ceramic electrodes are promising for use in SOFC anodes because they are expected to be less susceptible to sintering and coking, be redox stable, and be more tolerant of impurities like sulfur. In this thesis, for catalytic studies, the infiltration procedure has been used to form composites which have greatly simplified the search for the best ceramics for anode applications. In the development of ceramic fuel electrodes for SOFC, high performance can only be achieved when a transition metal catalyst is added. Because of the high operating temperatures, deactivation of the metal catalyst by sintering and/or coking is a severe problem. In this thesis, two approaches aimed at mitigating metal catalyst deactivation which was achieved by: 1) designing a catalyst that is resistant to coking and sintering and 2) developing a new method for catalyst deposition, will be presented. The first approach involved synthesizing a self-regenerating, "smart" catalyst, in which Co, Cu, or Ni were inserted into the B-site of a perovskite oxide under oxidizing conditions and then brought back to the surface under reducing conditions. This restores lost surface area of sintered metal particles through an oxidation/reduction cycle. Results will be shown for each of the metals, as well as for Cu-Co mixed metal systems, which are found to exhibit good tolerance to carbon deposition and interesting catalytic properties. The second strategy involves depositing novel Pd CeO2 core-shell nanostructure catalysts onto a substrate surface which had been chemically modified to anchor the nanoparticles. The catalyst deposited onto the chemically modified, hydrophobic surface is shown to be uniform and well dispersed, and exhibit excellent thermal stability to temperatures as high as 1373 K. Similar metal

  8. Performance of low smeared density sodium-cooled fast reactor metal fuel

    SciTech Connect

    Porter, D. L.; H. J. M. Chichester; Medvedev, P. G.; Hayes, S. L.; Teague, M. C.

    2015-06-17

    An experiment was performed in the Experimental Breeder Rector-II (EBR-II) in the 1990s to show that metallic fast reactor fuel could be used in reactors with a single, once-through core. To prove the long duration, high burnup, high neutron exposure capability an experiment where the fuel pin was designed with a very large fission gas plenum and very low fuel smeared density (SD). The experiment, X496, operated to only 8.3 at. % burnup because the EBR-II reactor was scheduled for shut-down at that time. Many of the examinations of the fuel pins only funded recently with the resurgence of reactor designs using very high-burnup fuel. The results showed that, despite the low smeared density of 59% the fuel swelled radially to contact the cladding, fission gas release appeared to be slightly higher than demonstrated in conventional 75%SD fuel tests and axial growth was about the same as 75% SD fuel. There were axial positions in some of the fuel pins which showed evidence of fuel restructuring and an absence of fission products with low metaling points and gaseous precursors (Cs and Rb). Lastly, a model to investigate whether these areas may have overheated due to a loss of bond sodium indicates that it is a possible explanation for the fuel restructuring and something to be considered for fuel performance modeling of low SD fuel.

  9. Performance of low smeared density sodium-cooled fast reactor metal fuel

    DOE PAGES

    Porter, D. L.; H. J. M. Chichester; Medvedev, P. G.; ...

    2015-06-17

    An experiment was performed in the Experimental Breeder Rector-II (EBR-II) in the 1990s to show that metallic fast reactor fuel could be used in reactors with a single, once-through core. To prove the long duration, high burnup, high neutron exposure capability an experiment where the fuel pin was designed with a very large fission gas plenum and very low fuel smeared density (SD). The experiment, X496, operated to only 8.3 at. % burnup because the EBR-II reactor was scheduled for shut-down at that time. Many of the examinations of the fuel pins only funded recently with the resurgence of reactormore » designs using very high-burnup fuel. The results showed that, despite the low smeared density of 59% the fuel swelled radially to contact the cladding, fission gas release appeared to be slightly higher than demonstrated in conventional 75%SD fuel tests and axial growth was about the same as 75% SD fuel. There were axial positions in some of the fuel pins which showed evidence of fuel restructuring and an absence of fission products with low metaling points and gaseous precursors (Cs and Rb). Lastly, a model to investigate whether these areas may have overheated due to a loss of bond sodium indicates that it is a possible explanation for the fuel restructuring and something to be considered for fuel performance modeling of low SD fuel.« less

  10. Regulatory Technology Development Plan - Sodium Fast Reactor. Mechanistic Source Term - Metal Fuel Radionuclide Release

    SciTech Connect

    Grabaskas, David; Bucknor, Matthew; Jerden, James

    2016-02-01

    The development of an accurate and defensible mechanistic source term will be vital for the future licensing efforts of metal fuel, pool-type sodium fast reactors. To assist in the creation of a comprehensive mechanistic source term, the current effort sought to estimate the release fraction of radionuclides from metal fuel pins to the primary sodium coolant during fuel pin failures at a variety of temperature conditions. These release estimates were based on the findings of an extensive literature search, which reviewed past experimentation and reactor fuel damage accidents. Data sources for each radionuclide of interest were reviewed to establish release fractions, along with possible release dependencies, and the corresponding uncertainty levels. Although the current knowledge base is substantial, and radionuclide release fractions were established for the elements deemed important for the determination of offsite consequences following a reactor accident, gaps were found pertaining to several radionuclides. First, there is uncertainty regarding the transport behavior of several radionuclides (iodine, barium, strontium, tellurium, and europium) during metal fuel irradiation to high burnup levels. The migration of these radionuclides within the fuel matrix and bond sodium region can greatly affect their release during pin failure incidents. Post-irradiation examination of existing high burnup metal fuel can likely resolve this knowledge gap. Second, data regarding the radionuclide release from molten high burnup metal fuel in sodium is sparse, which makes the assessment of radionuclide release from fuel melting accidents at high fuel burnup levels difficult. This gap could be addressed through fuel melting experimentation with samples from the existing high burnup metal fuel inventory.

  11. Actinides recovery from irradiated metallic fuel in LiCl-KCl melts

    NASA Astrophysics Data System (ADS)

    Murakami, T.; Rodrigues, A.; Ougier, M.; Iizuka, M.; Tsukada, T.; Glatz, J.-P.

    2015-11-01

    Electrorefining of irradiated metallic fuels was successfully demonstrated: Actinides (U, Pu, Np, Am and Cm) in the fuels were dissolved in LiCl-KCl melts with high dissolution ratios, while U was selectively deposited on a solid cathode and the simultaneous recovery of actinides in a liquid Cd cathode was confirmed. The behavior of actinides, the fuel matrix stabilizer Zr and fission products such as lanthanide, alkaline, alkaline earth and noble metal, at the electrorefining is discussed based on the ICP-MS analysis of the samples taken from molten salt electrolyte, anode fuel residues and cathode deposits.

  12. Emission FTIR analyses of thin microscopic patches of jet fuel residue deposited on heated metal surface

    NASA Technical Reports Server (NTRS)

    Lauer, J. L.; Vogel, P.

    1984-01-01

    Deposits laid down in patches on metal strips in a high pressure/high temperature fuel system simulator operated with aerated fuel at varying flow rates were analyzed by emission FTIR in terms of functional groups. Significant differences were found in the spectra and amounts of deposits derived from fuels to which small concentrations of oxygen-, nitrogen-, or sulfur-containing heterocyclics or metal naphthenates were added. The spectra of deposits generated on strips by heating fuels and air in a closed container were very different from those of the flowing fluid deposits. One such closed-container dodecane deposit on silver gave a strong surface-enhanced Raman spectrum.

  13. Thermochemical Processing of Radioactive Waste Using Powder Metal Fuels

    SciTech Connect

    Ojovan, M. I.; Sobolev, I. A.; Dmitriev, S. A.; Panteleev, V. I.; Karlina, O. K.; Klimov. V. L.

    2003-02-25

    Problematic radioactive wastes were generated during various activities of both industrial facilities and research institutions usually in relative small amounts. These can be spent ion exchange resins, inorganic absorbents, wastes from research nuclear reactors, irradiated graphite, mixed, organic or chlorine-containing radioactive waste, contaminated soils, un-burnable heavily surface-contaminated materials, etc. Conventional treatment methods encounter serious problems concerning processing efficiency of such waste, e.g. complete destruction of organic molecules and avoiding of possible emissions of radionuclides, heavy metals and chemically hazardous species. Some contaminations cannot be removed from surface using common decontamination methods. Conditioning of ash residues obtained after treatment of solid radioactive waste including ashes received from treating problematic wastes also is a complicated task. Moreover due to relative small volume of specific type radioactive waste the development of target treatment procedures and facilities to conduct technological processes and their deployment could be economically unexpedient and ecologically no justified. Thermochemical processing technologies are used for treating and conditioning problematic radioactive wastes. The thermochemical processing uses powdered metal fuels (PMF) that are specifically formulated for the waste composition and react chemically with the waste components. The composition of the PMF is designed in such a way as to minimize the release of hazardous components and radionuclides in the off gas and to confine the contaminants in the ash residue. The thermochemical procedures allow decomposition of organic matter and capturing hazardous radionuclides and chemical species simultaneously. A significant advantage of thermochemical processing is its autonomy. Thermochemical treatment technologies use the energy of exothermic reactions in the mixture of radioactive or hazardous waste with PMF

  14. Run - Beyond - Cladding - Breach (RBCB) test results for the Integral Fast Reactor (IFR) metallic fuels program

    SciTech Connect

    Batte, G.L. ); Hoffman, G.L. )

    1990-01-01

    In 1984 Argonne National Laboratory (ANL) began an aggressive program of research and development based on the concept of a closed system for fast-reactor power generation and on-site fuel reprocessing, exclusively designed around the use of metallic fuel. This is the Integral Fast Reactor (IFR). Although the Experimental Breeder Reactor-II (EBR-II) has used metallic fuel since its creation 25 yeas ago, in 1985 ANL began a study of the characteristics and behavior of an advanced-design metallic fuel based on uranium-zirconium (U-Zr) and uranium-plutonium-zirconium (U-Pu-Zr) alloys. During the past five years several areas were addressed concerning the performance of this fuel system. In all instances of testing the metallic fuel has demonstrated its ability to perform reliably to high burnups under varying design conditions. This paper will present one area of testing which concerns the fuel system's performance under breach conditions. It is the purpose of this paper to document the observed post-breach behavior of this advanced-design metallic fuel. 2 figs., 1 tab.

  15. Dimensional, microstructural and compositional stability of metal fuels. Final performance report

    SciTech Connect

    Solomon, A.A.; Dayananda, M.A.

    1993-03-15

    The projects undertaken were to address two areas of concern for metal-fueled fast reactors: metallurgical compatibility of fuel and its fission products with the stainless steel cladding, and effects of porosity development in the fuel on fuel/cladding interactions and on sodium penetration in fuel. The following studies are reported on extensively in appendices: hot isostatic pressing of U-10Zr by coupled boundary diffusion/power law creep cavitation, liquid Na intrusion into porous U-10Zr fuel alloy by differential capillarity, interdiffusion between U-Zr fuel and selected Fe-Ni-Cr alloys, interdiffusion between U-Zr fuel vs selected cladding steels, and interdiffusion of Ce in Fe-base alloys with Ni or Cr.

  16. Temperature and Burnup Correlated FCCI in U-10Zr Metallic Fuel

    SciTech Connect

    William J. Carmack

    2012-05-01

    Metallic fuels are proposed for use in advanced sodium cooled fast reactors. The experience basis for metallic fuels is extensive and includes development and qualification of fuels for the Experimental Breeder Reactor I, the Experimental Breeder Reactor II, FERMI-I, and the Fast Flux Test Facility (FFTF) reactors. Metallic fuels provide a number of advantages over other fuel types in terms of fabricability, performance, recyclability, and safety. Key to the performance of all nuclear fuel systems is the resistance to “breach” and subsequent release of fission products and fuel constituents to the primary coolant system of the nuclear power plant. In metallic fuel, the experience is that significant fuel-cladding chemical (FCCI) interaction occurs and becomes prevalent at high power-high temperature operation and ultimately leads to fuel pin breach and failure. Empirical relationships for metallic fuel pin failure have been developed from a large body of in-pile and out of pile research, development, and experimentation. It has been found that significant in-pile acceleration of the FCCI rate is experienced over similar condition out-of-pile experiments. The study of FCCI in metallic fuels has led to the quantification of in-pile failure rates to establish an empirical time and temperature dependent failure limit for fuel elements. Up until now the understanding of FCCI layer formation has been limited to data generated in EBR-II experiments. This dissertation provides new FCCI data extracted from the MFF-series of metallic fuel irradiations performed in the FFTF. These fuel assemblies contain valuable information on the formation of FCCI in metallic fuels at a variety of temperature and burnup conditions and in fuel with axial fuel height three times longer than EBR-II experiments. The longer fuel column in the FFTF and the fuel pins examined have significantly different flux, power, temperature, and FCCI profiles than that found in similar tests conducted in

  17. SUB-LEU-METAL-THERM-001 SUBCRITICAL MEASUREMENTS OF LOW ENRICHED TUBULAR URANIUM METAL FUEL ELEMENTS BEFORE & AFTER IRRADIATION

    SciTech Connect

    SCHWINKENDORF, K.N.

    2006-05-12

    With the shutdown of the Hanford PUREX (Plutonium-Uranium Extraction Plant) reprocessing plant in the 1970s, adequate storage capacity for spent Hanford N Reactor fuel elements in the K and N Reactor pools became a concern. To maximize space utilization in the pools, accounting for fuel burnup was considered. Calculations indicated that at typical fuel exposures for N Reactor, the spent-fuel critical mass would be twice the critical mass for green fuel. A decision was reached to test the calculational result with a definitive experiment. If the results proved positive, storage capacity could be increased and N Reactor operation could be prolonged. An experiment to be conducted in the N Reactor spent-fuel storage pool was designed and assembled and the services of the Battelle Northwest Laboratories (BNWL) (now Pacific Northwest National Laboratory [PNNL]) critical mass laboratory were procured for the measurements. The experiments were performed in April 1975 in the Hanford N Reactor fuel storage pool. The fuel elements were MKIA fuel assemblies, comprising two concentric tubes of low-enriched metallic uranium. Two separate sets of measurements were performed: one with ''green'' (fresh) fuel and one with spent fuel. Both the green and spent fuel, were measured in the same geometry. The spent-fuel MKIA assemblies had an average burnup of 2865 MWd (megawatt days)/t. A constraint was imposed restricting the measurements to a subcritical limit of k{sub eff} = 0.97. Subcritical count rate data was obtained with pulsed-neutron and approach-to-critical measurements. Ten (10) configurations with green fuel and nine (9) configurations with spent fuel are described and evaluated. Of these, 3 green fuel and 4 spent fuel loading configurations were considered to serve as benchmark models. However, shortcomings in experimental data failed to meet the high standards for a benchmark problem. Nevertheless, the data provided by these subcritical measurements can supply useful

  18. Pumped lithium loop test to evaluate advanced refractory metal alloys and simulated nuclear fuel elements

    NASA Technical Reports Server (NTRS)

    Brandenburf, G. P.; Hoffman, E. E.; Smith, J. P.

    1974-01-01

    The performance was determined of refractory metal alloys and uranium nitride fuel element specimens in flowing 1900F (1083C) lithium. The results demonstrate the suitability of the selected materials to perform satisfactorily from a chemical compatibility standpoint.

  19. EBR-II spent fuel treatment demonstration project status

    SciTech Connect

    Benedict, R.W.; Henslee, S.P.

    1998-07-01

    The application of electrometallurgical technology to spent nuclear fuel treatment is being demonstrated by treating 410 kg uranium spent driver fuel and 1,200 kg uranium spent blanket fuel from the Experimental Breeder Reactor-II (EBR-II) spent driver and blanket fuel. This fuel is a metallic uranium alloy and contains elemental sodium, which is a reactive material. Since reactive material is considered hazardous by US Environmental Protection Agency regulations, this fuel requires treatment before disposal in a geologic repository. The EBR-II spent fuel treatment demonstration conditions this fuel in an integrated process where the fuel is converted into three different products: low enriched uranium (LEU), ceramic waste and metallic waste. This demonstration was initiated in June 1996 and has treated approximately 50% of the driver fuel. The higher throughput equipment that will be used for blanket treatment processes has been installed in the hot cell facility and is being tested with depleted uranium. Metal waste forms have been produced from the irradiated metals from the driver fuel. Ceramic waste process equipment has been built and is being tested before installation in the hot cell facilities. This paper discusses the processes and the current results from the first 20 months of operation.

  20. Performance of low smeared density sodium-cooled fast reactor metal fuel

    NASA Astrophysics Data System (ADS)

    Porter, D. L.; Chichester, H. J. M.; Medvedev, P. G.; Hayes, S. L.; Teague, M. C.

    2015-10-01

    An experiment was performed in the Experimental Breeder Rector-II (EBR-II) in the 1990s to show that metallic fast reactor fuel could be used in reactors with a single, once-through core. To prove the long duration, high burnup, high neutron exposure capability an experiment where the fuel pin was designed with a very large fission gas plenum and very low fuel smeared density (SD). The experiment, X496, operated to only 8.3 at.% burnup because the EBR-II reactor was scheduled for shut-down at that time. Many of the examinations of the fuel pins only funded recently with the resurgence of reactor designs using very high-burnup fuel. The results showed that, despite the low smeared density of 59% the fuel swelled radially to contact the cladding, fission gas release appeared to be slightly higher than demonstrated in conventional 75%SD fuel tests and axial growth was about the same as 75% SD fuel. There were axial positions in some of the fuel pins which showed evidence of fuel restructuring and an absence of fission products with low melting points and gaseous precursors (Cs and Rb). A model to investigate whether these areas may have overheated due to a loss of bond sodium indicates that it is a possible explanation for the fuel restructuring and something to be considered for fuel performance modeling of low SD fuel.

  1. Electrometallurgical treatment of metal, oxide, and aluminum-alloy spent nuclear fuel types.

    SciTech Connect

    McPheeters, C. C.; Gay, E. C.; Karell, E. J.; Ackerman, J. P.; Chemical Engineering

    1997-01-01

    Electrorefining uranium in a molten salt bath is the key step in the electrometallurgical treatment of spent nuclear fuels. The versatility of the electrometallurgical treatment suggests its use for a variety of spent fuel types, as well as for nonnuclear metal-separation applications.

  2. Heavy metal inventory and fuel sustainability of recycling TRU in FBR design

    SciTech Connect

    Permana, Sidik; Suzuki, Mitsutoshi; Su'ud, Zaki

    2012-06-06

    Nuclear fuel materials from spent fuel of light water reactors have a potential to be used for destructive devices with very huge energy release or in the same time, it can be utilized as a peaceful energy or civil applications, for generating electricity, desalination of water, medical application and others applications. Several research activities showed some recycled spent fuel can be used as additional fuel loading for increasing fuel breeding capability as well as improving intrinsic aspect of nuclear non-proliferation. The present investigation intends to evaluate the composition of heavy metals inventories and fuel breeding capability in the FBR design based on the loaded fuel of light water reactor (LWR) spent fuel (SF) of 33 GWd/t with 5 years cooling time by adopting depletion code of ORIGEN. Whole core analysis of FBR design is performed by adopting and coupling codes such as SLAROM code, JOINT and CITATION codes. Nuclear data library, JFS-3-J-3.2R which is based on the JENDL 3.2 has been used for nuclear data analysis. JSFR design is the basis design reference which basically adopted 800 days cycle length for 4 batches system. Higher inventories of plutonium of MOX fuel and TRU fuel types at equilibrium composition than initial composition have been shown. Minor actinide (MA) inventory compositions obtain a different inventory trends at equilibrium composition for both fuel types. Higher Inventory of MA is obtained by MOX fuel and less MA inventory for TRU fuel at equilibrium composition than initial composition. Some different MA inventories can be estimated from the different inventory trend of americium (Am). Higher americium inventory for MOX fuel and less americium inventory for TRU fuel at equilibrium condition. Breeding ratio of TRU fuel is relatively higher compared with MOX fuel type. It can be estimated from relatively higher production of Pu-238 (through converted MA) in TRU fuel, and Pu-238 converts through neutron capture to produce Pu-239

  3. Heavy metal inventory and fuel sustainability of recycling TRU in FBR design

    NASA Astrophysics Data System (ADS)

    Permana, Sidik; Suzuki, Mitsutoshi; Su'ud, Zaki

    2012-06-01

    Nuclear fuel materials from spent fuel of light water reactors have a potential to be used for destructive devices with very huge energy release or in the same time, it can be utilized as a peaceful energy or civil applications, for generating electricity, desalination of water, medical application and others applications. Several research activities showed some recycled spent fuel can be used as additional fuel loading for increasing fuel breeding capability as well as improving intrinsic aspect of nuclear non-proliferation. The present investigation intends to evaluate the composition of heavy metals inventories and fuel breeding capability in the FBR design based on the loaded fuel of light water reactor (LWR) spent fuel (SF) of 33 GWd/t with 5 years cooling time by adopting depletion code of ORIGEN. Whole core analysis of FBR design is performed by adopting and coupling codes such as SLAROM code, JOINT and CITATION codes. Nuclear data library, JFS-3-J-3.2R which is based on the JENDL 3.2 has been used for nuclear data analysis. JSFR design is the basis design reference which basically adopted 800 days cycle length for 4 batches system. Higher inventories of plutonium of MOX fuel and TRU fuel types at equilibrium composition than initial composition have been shown. Minor actinide (MA) inventory compositions obtain a different inventory trends at equilibrium composition for both fuel types. Higher Inventory of MA is obtained by MOX fuel and less MA inventory for TRU fuel at equilibrium composition than initial composition. Some different MA inventories can be estimated from the different inventory trend of americium (Am). Higher americium inventory for MOX fuel and less americium inventory for TRU fuel at equilibrium condition. Breeding ratio of TRU fuel is relatively higher compared with MOX fuel type. It can be estimated from relatively higher production of Pu-238 (through converted MA) in TRU fuel, and Pu-238 converts through neutron capture to produce Pu-239

  4. Simulation of the impact of 3-D porosity distribution in metallic U-10Zr fuels

    NASA Astrophysics Data System (ADS)

    Yun, Di; Yacout, Abdellatif M.; Stan, Marius; Bauer, Theodore H.; Wright, Arthur E.

    2014-05-01

    Evolution of porosity generated in metallic U-Zr fuel irradiated in fast spectrum reactors leads to changes in fuel properties and impacts important phenomena such as heat transport and constituent redistribution. The porosity is generated as a result of the accumulation of fission gases and is affected by the possible bond sodium infiltration into the fuel. Typically, the impact of porosity development on properties, such as thermal conductivity, is accounted for through empirical correlations that are dependent on porosity and infiltrated sodium fractions. Currently available simulation tools make it possible to take into account fuel 3-D porosity distributions, potentially eliminating the need for such correlations. This development allows for a more realistic representation of the porosity evolution in metallic fuel and creates a framework for truly mechanistic fuel development models. In this work, COMSOL multi-physics simulation platform is used to model 3-D porosity distributions and simulate heat transport in metallic U-10Zr fuel. Available experimental data regarding microstructural evolution of fuel that was irradiated in EBR-II and associated phase stability information are used to guide the simulation. The impact of changes in porosity characteristics on material properties is estimated and the results are compared with calculated temperature distributions. The simulations demonstrate the developed capability and importance of accounting for detailed porosity distribution features for accurate fuel performance evaluation.

  5. Fuel Cycle System Analysis Implications of Sodium-Cooled Metal-Fueled Fast Reactor Transuranic Conversion Ratio

    SciTech Connect

    Steven J. Piet; Edward A. Hoffman; Samuel E. Bays; Gretchen E. Matthern; Jacob J. Jacobson; Ryan Clement; David W. Gerts

    2013-03-01

    If advanced fuel cycles are to include a large number of fast reactors (FRs), what should be the transuranic (TRU) conversion ratio (CR)? The nuclear energy era started with the assumption that they should be breeder reactors (CR > 1), but the full range of possible CRs eventually received attention. For example, during the recent U.S. Global Nuclear Energy Partnership program, the proposal was burner reactors (CR < 1). Yet, more recently, Massachusetts Institute of Technology's "Future of the Nuclear Fuel Cycle" proposed CR [approximately] 1. Meanwhile, the French company EDF remains focused on breeders. At least one of the reasons for the differences of approach is different fuel cycle objectives. To clarify matters, this paper analyzes the impact of TRU CR on many parameters relevant to fuel cycle systems and therefore spans a broad range of topic areas. The analyses are based on a FR physics parameter scan of TRU CR from 0 to [approximately]1.8 in a sodium-cooled metal-fueled FR (SMFR), in which the fuel from uranium-oxide-fueled light water reactors (LWRs) is recycled directly to FRs and FRs displace LWRs in the fleet. In this instance, the FRs are sodium cooled and metal fueled. Generally, it is assumed that all TRU elements are recycled, which maximizes uranium ore utilization for a given TRU CR and waste radiotoxicity reduction and is consistent with the assumption of used metal fuel separated by electrochemical means. In these analyses, the fuel burnup was constrained by imposing a neutron fluence limit to fuel cladding to the same constant value. This paper first presents static, time-independent measures of performance for the LWR [right arrow] FR fuel cycle, including mass, heat, gamma emission, radiotoxicity, and the two figures of merit for materials for weapon attractiveness developed by C. Bathke et al. No new fuel cycle will achieve a static equilibrium in the foreseeable future. Therefore, additional analyses are shown with dynamic, time

  6. A direct borohydride fuel cell with a polymer fiber membrane and non-noble metal catalysts

    PubMed Central

    Yang, Xiaodong; Liu, Yongning; Li, Sai; Wei, Xiaozhu; Wang, Li; Chen, Yuanzhen

    2012-01-01

    Polymer electrolyte membranes (PEM) and Pt-based catalysts are two crucial components which determine the properties and price of fuel cells. Even though, PEM faces problem of fuel crossover in liquid fuel cells such as direct methanol fuel cell (DMFC) and direct borohydride fuel cell (DBFC), which lowers power output greatly. Here, we report a DBFC in which a polymer fiber membrane (PFM) was used, and metal oxides, such as LaNiO3 and MnO2, were used as cathode catalysts, meanwhile CoO was used as anode catalyst. Peak power density of 663 mW·cm−2 has been achieved at 65°C, which increases by a factor of 1.7–3.7 compared with classic DBFCs. This fuel cell structure can also be extended to other liquid fuel cells, such as DMFC. PMID:22880160

  7. A direct borohydride fuel cell with a polymer fiber membrane and non-noble metal catalysts.

    PubMed

    Yang, Xiaodong; Liu, Yongning; Li, Sai; Wei, Xiaozhu; Wang, Li; Chen, Yuanzhen

    2012-01-01

    Polymer electrolyte membranes (PEM) and Pt-based catalysts are two crucial components which determine the properties and price of fuel cells. Even though, PEM faces problem of fuel crossover in liquid fuel cells such as direct methanol fuel cell (DMFC) and direct borohydride fuel cell (DBFC), which lowers power output greatly. Here, we report a DBFC in which a polymer fiber membrane (PFM) was used, and metal oxides, such as LaNiO₃ and MnO₂, were used as cathode catalysts, meanwhile CoO was used as anode catalyst. Peak power density of 663 mW·cm⁻² has been achieved at 65°C, which increases by a factor of 1.7-3.7 compared with classic DBFCs. This fuel cell structure can also be extended to other liquid fuel cells, such as DMFC.

  8. Recent irradiation tests of uranium-plutonium-zirconium metal fuel elements

    SciTech Connect

    Pahl, R.G.; Lahm, C.E.; Villarreal, R.; Hofman, G.L.; Beck, W.N.

    1986-09-01

    Uranium-Plutonium-Zirconium metal fuel irradiation tests to support the ANL Integral Fast Reactor concept are discussed. Satisfactory performance has been demonstrated to 2.9 at.% peak burnup in three alloys having 0, 8, and 19 wt % plutonium. Fuel swelling measurements at low burnup in alloys to 26 wt % plutonium show that fuel deformation is primarily radial in direction. Increasing the plutonium content in the fuel diminishes the rate of fuel-cladding gap closure and axial fuel column growth. Chemical redistribution occurs by 2.1 at.% peak burnup and generally involves the inward migration of zirconium and outward migration of uranium. Fission gas release to the plenum ranges from 46% to 56% in the alloys irradiated to 2.9 at.% peak burnup. No evidence of deleterious fuel-cladding chemical or mechanical interaction was observed.

  9. Fate of Noble Metals during the Pyroprocessing of Spent Nuclear Fuel

    SciTech Connect

    B.R. Westphal; D. Vaden; S.X. Li; G.L. Fredrickson; R.D. Mariani

    2009-09-01

    During the pyroprocessing of spent nuclear fuel by electrochemical techniques, fission products are separated as the fuel is oxidized at the anode and refined uranium is deposited at the cathode. Those fission products that are oxidized into the molten salt electrolyte are considered active metals while those that do not react are considered noble metals. The primary noble metals encountered during pyroprocessing are molybdenum, zirconium, ruthenium, rhodium, palladium, and technetium. Pyroprocessing of spent fuel to date has involved two distinctly different electrorefiner designs, in particular the anode to cathode configuration. For one electrorefiner, the anode and cathode collector are horizontally displaced such that uranium is transported across the electrolyte medium. As expected, the noble metal removal from the uranium during refining is very high, typically in excess of 99%. For the other electrorefiner, the anode and cathode collector are vertically collocated to maximize uranium throughput. This arrangement results in significantly less noble metals removal from the uranium during refining, typically no better than 20%. In addition to electrorefiner design, operating parameters can also influence the retention of noble metals, albeit at the cost of uranium recovery. Experiments performed to date have shown that as much as 100% of the noble metals can be retained by the cladding hulls while affecting the uranium recovery by only 6%. However, it is likely that commercial pyroprocessing of spent fuel will require the uranium recovery to be much closer to 100%. The above mentioned design and operational issues will likely be driven by the effects of noble metal contamination on fuel fabrication and performance. These effects will be presented in terms of thermal properties (expansion, conductivity, and fusion) and radioactivity considerations. Ultimately, the incorporation of minor amounts of noble metals from pyroprocessing into fast reactor metallic fuel

  10. Electrometallurgical treatment of metallic spent nuclear fuel stored at the Hanford Site

    SciTech Connect

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

    1996-05-01

    The major component of the DOE spent nuclear fuel inventory is the metallic fuel stored at the Hanford site in the southeastern part of the state of Washington. Most of this fuel was discharged from the N-Reactor; a small part of the inventory is fuel from the early Hanford production reactors. The U.S. Department of Energy (DOE) plans to remove these fuels from the spent fuel storage pools in which they are presently stored, dry them, and place them in interim storage at a location at the Hanford site that is far removed from the Columbia River. It is not yet certain that these fuels will be acceptable for disposal in a mined geologic repository without further treatment, due to their potential pyrophoric character. A practical method for treatment of the Hanford metallic spent fuel, based on an electrorefining process, has been developed and has been demonstrated with unirradiated N-Reactor fuel and with simulated single-pass reactor (SPR) spent fuel. The process can be operated with any desired throughput rates; being a batch process, it is simply a matter of setting the size of the electrorefiner modules and the number of such modules. A single module, prototypic of a production-scale module, has been fabricated and testing is in progress at a throughput rate of 150 kg (heavy metal) per day. The envisioned production version would incorporate additional anode baskets and cathode tubes and provide a throughput rate of 333 kgHM/day. A system with four of these modules would permit treatment of Hanford metallic fuels at a rate of at least 250 metric tons per year.

  11. Simplified process for leaching precious metals from fuel cell membrane electrode assemblies

    DOEpatents

    Shore, Lawrence; Matlin, Ramail

    2009-12-22

    The membrane electrode assemblies of fuel cells are recycled to recover the catalyst precious metals from the assemblies. The assemblies are cryogenically embrittled and pulverized to form a powder. The pulverized assemblies are then mixed with a surfactant to form a paste which is contacted with an acid solution to leach precious metals from the pulverized membranes.

  12. Anodic dissolution of irradiated metallic fuels in LiCl-KCl melt

    NASA Astrophysics Data System (ADS)

    Murakami, T.; Kato, T.; Rodrigues, A.; Ougier, M.; Iizuka, M.; Koyama, T.; Glatz, J.-P.

    2014-09-01

    Electrorefining is the main step in pyro-process of spent nuclear fuels, where actinides are recovered and separated from fission products. In the present study, electrorefining of irradiated metallic fuels called METAPHIX-1 (U-19 wt%Pu-10 wt%Zr alloy irradiated at PHENIX reactor, approximate maximum burn-up 2.5 at%) was performed. A major focus was on minimization of Zr co-dissolution from spent metallic fuels to reduce the burden to the pyro-process. Based on the ICP-MS analysis results and the SEM-EDX observations, the anodic dissolution behavior of the irradiated metallic fuels and the mass balances of actinides and fission products during the electrorefining were evaluated.

  13. Water storage of liquid-metal fast-breeder-reactor fuel

    SciTech Connect

    Meacham, S.A.

    1982-01-01

    The purpose of this paper is to present a general overview of a concept proposed for receiving and storing liquid metal fast breeder reactor (LMFBR) spent fuel. This work was done as part of the Consolidated Fuel Reprocessing Program (CFRP) at the Oak Ridge National Laboratory (ORNL). The CFRP has as its major objective the development of technology for reprocessing advanced nuclear reactor fuels. The program plans that research and development will be carried through to a sufficient scale, using irradiated spent fuel under plant operating conditions, to establish a basis for confident projection of reprocessing capability to support a breeder industry.

  14. Nuclear Rocket Ceramic Metal Fuel Fabrication Using Tungsten Powder Coating and Spark Plasma Sintering

    NASA Technical Reports Server (NTRS)

    Barnes, M. W.; Tucker, D. S.; Hone, L.; Cook, S.

    2017-01-01

    Nuclear thermal propulsion is an enabling technology for crewed Mars missions. An investigation was conducted to evaluate spark plasma sintering (SPS) as a method to produce tungsten-depleted uranium dioxide (W-dUO2) fuel material when employing fuel particles that were tungsten powder coated. Ceramic metal fuel wafers were produced from a blend of W-60vol% dUO2 powder that was sintered via SPS. The maximum sintering temperatures were varied from 1,600 to 1,850 C while applying a 50-MPa axial load. Wafers exhibited high density (>95% of theoretical) and a uniform microstructure (fuel particles uniformly dispersed throughout tungsten matrix).

  15. Nanotextured metal copper substrates as powerful and long-lasting fuel cell anodes.

    PubMed

    Filanovsky, Boris; Granot, Eran; Dirawi, Rawi; Presman, Igor; Kuras, Iliya; Patolsky, Fernando

    2011-04-13

    Fuel cells (FCs) are promising electrochemical devices that convert chemical energy of fuels directly into electrical energy. We present a new anode material based on nanotextured metal copper for fuel cell applications. We have demonstrated that low-cost copper catalyst anodes act as highly efficient and ultra-long-lasting materials for the direct electro-oxidation of ammonia-borane and additional amine derivatives. High power densities of ca. 1W·cm(-2) (ca. -1 V vs Ag/AgCl at 1 A) are readily achieved at room temperature. We fabricate fuel cell devices based on our nanotextured Cu anodes in combination with commercial air cathodes.

  16. Time constants and transfer functions for a homogeneous 900 MWt metallic fueled LMR

    SciTech Connect

    Grimm, K.N.; Meneghetti, D.

    1988-01-01

    Nodal transfer functions are calculated for a 900 MWt U10Zr-fueled sodium cooled reactor. From the transfer functions the time constants, feedback reactivity transfer function coefficients, and power coefficients can be determined. These quantities are calculated for core fuel, upper and lower axial reflector steel, radial blanket fuel, radial reflector steel, and B/sub 4/C rod shaft expansion effect. The quantities are compared to the analogous quantities of a 60 MWt metallic-fueled sodium cooled Experimental Breeder Reactor II configuration. 8 refs., 2 figs., 6 tabs.

  17. Yttrium and rare earth stabilized fast reactor metal fuel

    DOEpatents

    Guon, Jerold; Grantham, LeRoy F.; Specht, Eugene R.

    1992-01-01

    To increase the operating temperature of a reactor, the melting point and mechanical properties of the fuel must be increased. For an actinide-rich fuel, yttrium, lanthanum and/or rare earth elements can be added, as stabilizers, to uranium and plutonium and/or a mixture of other actinides to raise the melting point of the fuel and improve its mechanical properties. Since only about 1% of the actinide fuel may be yttrium, lanthanum, or a rare earth element, the neutron penalty is low, the reactor core size can be reduced, the fuel can be burned efficiently, reprocessing requirements are reduced, and the nuclear waste disposal volumes reduced. A further advantage occurs when yttrium, lanthanum, and/or other rare earth elements are exposed to radiation in a reactor, they produce only short half life radioisotopes, which reduce nuclear waste disposal problems through much shorter assured-isolation requirements.

  18. Sensitivity Analysis of FEAST-Metal Fuel Performance Code: Initial Results

    SciTech Connect

    Edelmann, Paul Guy; Williams, Brian J.; Unal, Cetin; Yacout, Abdellatif

    2012-06-27

    This memo documents the completion of the LANL milestone, M3FT-12LA0202041, describing methodologies and initial results using FEAST-Metal. The FEAST-Metal code calculations for this work are being conducted at LANL in support of on-going activities related to sensitivity analysis of fuel performance codes. The objective is to identify important macroscopic parameters of interest to modeling and simulation of metallic fuel performance. This report summarizes our preliminary results for the sensitivity analysis using 6 calibration datasets for metallic fuel developed at ANL for EBR-II experiments. Sensitivity ranking methodology was deployed to narrow down the selected parameters for the current study. There are approximately 84 calibration parameters in the FEAST-Metal code, of which 32 were ultimately used in Phase II of this study. Preliminary results of this sensitivity analysis led to the following ranking of FEAST models for future calibration and improvements: fuel conductivity, fission gas transport/release, fuel creep, and precipitation kinetics. More validation data is needed to validate calibrated parameter distributions for future uncertainty quantification studies with FEAST-Metal. Results of this study also served to point out some code deficiencies and possible errors, and these are being investigated in order to determine root causes and to improve upon the existing code models.

  19. AN EVALUATION OF POTENTIAL LINER MATERIALS FOR ELIMINATING FCCI IN IRRADIATED METALLIC NUCLEAR FUEL ELEMENTS

    SciTech Connect

    D. D. Keiser; J. I. Cole

    2007-09-01

    Metallic nuclear fuels are being looked at as part of the Global Nuclear Energy Program for transmuting longlive transuranic actinide isotopes contained in spent nuclear fuel into shorter-lived fission products. In order to optimize the performance of these fuels, the concept of using liners to eliminate the fuel/cladding chemical interactions that can occur during irradiation of a fuel element has been investigated. The potential liner materials Zr and V have been tested using solid-solid diffusion couples, consisting of liner materials butted against fuel alloys and against cladding materials. The couples were annealed at the relatively high temperature of 700°C. This temperature would be the absolute maximum temperature present at the fuel/cladding interface for a fuel element in-reactor. Analysis was performed using a scanning electron microscope equipped with energy-dispersive and wavelengthdispersive spectrometers (SEM/EDS/WDS) to evaluate any developed diffusion structures. At 700°C, minimal interaction was observed between the metallic fuels and either Zr or V. Similarly, limited interaction was observed between the Zr and V and the cladding materials. The best performing liner material appeared to be the V, based on amounts of interaction.

  20. SUB-LEU-METAL-THERM-001 SUBCRITICAL MEASUREMENTS OF LOW ENRICHED TUBULAR URANIUM METAL FUEL ELEMENTS BEFORE & AFTER IRRADIATION

    SciTech Connect

    TOFFER, H.

    2006-07-18

    With the shutdown of the Hanford PUREX (Plutonium-Uranium Extraction Plant) reprocessing plant in the 1970s, adequate storage capacity for spent Hanford N Reactor fuel elements in the K and N Reactor pools became a concern. To maximize space utilization in the pools, accounting for fuel burnup was considered. Fuel that had experienced a neutron environment in a reactor is known as spent, exposed, or irradiated fuel. In contrast fuel that has not yet been placed in a reactor is known as green, unexposed, or unirradiated fuel. Calculations indicated that at typical fuel exposures for N Reactor, the spent-fuel critical mass would be twice the critical mass for green fuel. A decision was reached to test the calculational result with a definitive experiment. If the results proved positive, storage capacity could be increased and N Reactor operation could be prolonged. An experiment to be conducted in the N Reactor spent-fuel storage pool was designed and assembled (References 1 and 2) and the services of the Battelle Northwest Laboratories (BNWL) (now Pacific Northwest National Laboratory [PNNL]) critical mass laboratory were procured for the measurements (Reference 3). The experiments were performed in April 1975 in the Hanford N Reactor fuel storage pool. The fuel elements were MKIA fuel assemblies, comprised of two concentric tubes of low-enriched metallic uranium. Two separate sets of measurements were performed: one with unirradiated fuel and one with irradiated fuel. Both the unirradiated and irradiated fuel, were measured in the same geometry. The spent-fuel MKIA assemblies had an average burnup of 2865 MWd (megawatt days)/t. A constraint was imposed restricting the measurements to a subcritical limit of k{sub eff} = 0.97. Subcritical count rate data was obtained with pulsed-neutron and approach-to-critical measurements. Ten (10) configurations with green fuel and nine (9) configurations with spent fuel are described and evaluated. Of these, three (3) green fuel

  1. Ancient Heavy Metal Contamination in Soils as a Driver of Tolerant Anthyllis vulneraria Rhizobial Communities.

    PubMed

    Mohamad, Roba; Maynaud, Geraldine; Le Quéré, Antoine; Vidal, Céline; Klonowska, Agnieszka; Yashiro, Erika; Cleyet-Marel, Jean-Claude; Brunel, Brigitte

    2017-01-15

    Anthyllis vulneraria is a legume associated with nitrogen-fixing rhizobia that together offer an adapted biological material for mine-soil phytostabilization by limiting metal pollution. To find rhizobia associated with Anthyllis at a given site, we evaluated the genetic and phenotypic properties of a collection of 137 rhizobia recovered from soils presenting contrasting metal levels. Zn-Pb mine soils largely contained metal-tolerant rhizobia belonging to Mesorhizobium metallidurans or to another sister metal-tolerant species. All of the metal-tolerant isolates harbored the cadA marker gene (encoding a metal-efflux PIB-type ATPase transporter). In contrast, metal-sensitive strains were taxonomically distinct from metal-tolerant populations and consisted of new Mesorhizobium genospecies. Based on the symbiotic nodA marker, the populations comprise two symbiovar assemblages (potentially related to Anthyllis or Lotus host preferences) according to soil geographic locations but independently of metal content. Multivariate analysis showed that soil Pb and Cd concentrations differentially impacted the rhizobial communities and that a rhizobial community found in one geographically distant site was highly divergent from the others. In conclusion, heavy metal levels in soils drive the taxonomic composition of Anthyllis-associated rhizobial populations according to their metal-tolerance phenotype but not their symbiotic nodA diversity. In addition to heavy metals, local soil physicochemical and topoclimatic conditions also impact the rhizobial beta diversity. Mesorhizobium communities were locally adapted and site specific, and their use is recommended for the success of phytostabilization strategies based on Mesorhizobium-legume vegetation. Phytostabilization of toxic mine spoils limits heavy metal dispersion and environmental pollution by establishing a sustainable plant cover. This eco-friendly method is facilitated by the use of selected and adapted cover crop legumes

  2. Ancient Heavy Metal Contamination in Soils as a Driver of Tolerant Anthyllis vulneraria Rhizobial Communities

    PubMed Central

    Mohamad, Roba; Maynaud, Geraldine; Le Quéré, Antoine; Vidal, Céline; Klonowska, Agnieszka; Yashiro, Erika; Cleyet-Marel, Jean-Claude

    2016-01-01

    ABSTRACT Anthyllis vulneraria is a legume associated with nitrogen-fixing rhizobia that together offer an adapted biological material for mine-soil phytostabilization by limiting metal pollution. To find rhizobia associated with Anthyllis at a given site, we evaluated the genetic and phenotypic properties of a collection of 137 rhizobia recovered from soils presenting contrasting metal levels. Zn-Pb mine soils largely contained metal-tolerant rhizobia belonging to Mesorhizobium metallidurans or to another sister metal-tolerant species. All of the metal-tolerant isolates harbored the cadA marker gene (encoding a metal-efflux PIB-type ATPase transporter). In contrast, metal-sensitive strains were taxonomically distinct from metal-tolerant populations and consisted of new Mesorhizobium genospecies. Based on the symbiotic nodA marker, the populations comprise two symbiovar assemblages (potentially related to Anthyllis or Lotus host preferences) according to soil geographic locations but independently of metal content. Multivariate analysis showed that soil Pb and Cd concentrations differentially impacted the rhizobial communities and that a rhizobial community found in one geographically distant site was highly divergent from the others. In conclusion, heavy metal levels in soils drive the taxonomic composition of Anthyllis-associated rhizobial populations according to their metal-tolerance phenotype but not their symbiotic nodA diversity. In addition to heavy metals, local soil physicochemical and topoclimatic conditions also impact the rhizobial beta diversity. Mesorhizobium communities were locally adapted and site specific, and their use is recommended for the success of phytostabilization strategies based on Mesorhizobium-legume vegetation. IMPORTANCE Phytostabilization of toxic mine spoils limits heavy metal dispersion and environmental pollution by establishing a sustainable plant cover. This eco-friendly method is facilitated by the use of selected and adapted

  3. HOT CELL SYSTEM FOR DETERMINING FISSION GAS RETENTION IN METALLIC FUELS

    SciTech Connect

    Sell, D. A.; Baily, C. E.; Malewitz, T. J.; Medvedev, P. G.; Porter, D. L.; Hilton, B. A.

    2016-09-01

    A system has been developed to perform measurements on irradiated, sodium bonded-metallic fuel elements to determine the amount of fission gas retained in the fuel material after release of the gas to the element plenum. During irradiation of metallic fuel elements, most of the fission gas developed is released from the fuel and captured in the gas plenums of the fuel elements. A significant amount of fission gas, however, remains captured in closed porosities which develop in the fuel during irradiation. Additionally, some gas is trapped in open porosity but sealed off from the plenum by frozen bond sodium after the element has cooled in the hot cell. The Retained fission Gas (RFG) system has been designed, tested and implemented to capture and measure the quantity of retained fission gas in characterized cut pieces of sodium bonded metallic fuel. Fuel pieces are loaded into the apparatus along with a prescribed amount of iron powder, which is used to create a relatively low melting, eutectic composition as the iron diffuses into the fuel. The apparatus is sealed, evacuated, and then heated to temperatures in excess of the eutectic melting point. Retained fission gas release is monitored by pressure transducers during the heating phase, thus monitoring for release of fission gas as first the bond sodium melts and then the fuel. A separate hot cell system is used to sample the gas in the apparatus and also characterize the volume of the apparatus thus permitting the calculation of the total fission gas release from the fuel element samples along with analysis of the gas composition.

  4. Microstructural Changes In Thermally Cycled U-Pu-Zr-Am-Np Metallic Transmutation Fuel With 1.5% Lanthanides

    SciTech Connect

    Dawn E. Janney; J. Rory Kennedy

    2008-06-01

    The United States Department of Energy (DOE) Global Nuclear Energy Partnership (GNEP) is developing metallic actinide-zirconium alloy fuels for the transmutation of minor actinides as part of a closed fuel cycle. The molten salt electrochemical process to be used for fuel recycle has the potential to carry over up to 2% fission product lanthanide content into the fuel fabrication process. Within the scope of the fuel irradiation testing program at Idaho National Laboratory (INL), candidate metal alloy transmutation fuels containing quantities of lanthanide elements have been fabricated, characterized, and delivered to the Advanced Test Reactor for irradiation testing.

  5. Characterization of Irradiated Metal Waste from the Pyrometallurgical Treatment of Used EBR-II Fuel

    SciTech Connect

    B.R. Westphal; K.C. Marsden; W.M. McCartin; S.M. Frank; D.D. Keiser, Jr.; T.S. Yoo; D. Vaden; D.G. Cummings; K.J. Bateman; J. J. Giglio; T. P. O'Holleran; P. A. Hahn; M. N. Patterson

    2013-03-01

    As part of the pyrometallurgical treatment of used Experimental Breeder Reactor-II fuel, a metal waste stream is generated consisting primarily of cladding hulls laden with fission products noble to the electrorefining process. Consolidation by melting at high temperature [1873 K (1600 degrees C)] has been developed to sequester the noble metal fission products (Zr, Mo, Tc, Ru, Rh, Te, and Pd) which remain in the iron-based cladding hulls. Zirconium from the uranium fuel alloy (U-10Zr) is also deposited on the hulls and forms Fe-Zr intermetallics which incorporate the noble metals as well as residual actinides during processing. Hence, Zr has been chosen as the primary indicator for consistency of the metal waste. Recently, the first production-scale metal waste ingot was generated and sampled to monitor Zr content for Fe-Zr intermetallic phase formation and validation of processing conditions. Chemical assay of the metal waste ingot revealed a homogeneous distribution of the noble metal fission products as well as the primary fuel constituents U and Zr. Microstructural characterization of the ingot confirmed the immobilization of the noble metals in the Fe-Zr intermetallic phase.

  6. Characterization of Irradiated Metal Waste from the Pyrometallurgical Treatment of Used EBR-II Fuel

    NASA Astrophysics Data System (ADS)

    Westphal, Brian R.; Frank, S. M.; McCartin, W. M.; Cummings, D. G.; Giglio, J. J.; O'Holleran, T. P.; Hahn, P. A.; Yoo, T. S.; Marsden, K. C.; Bateman, K. J.; Patterson, M. N.

    2015-01-01

    As part of the pyrometallurgical treatment of used Experimental Breeder Reactor-II fuel, a metal waste stream is generated consisting primarily of cladding hulls laden with fission products noble to the electrorefining process. Consolidation by melting at high temperature [1873 K (1600 °C)] has been developed to sequester the noble metal fission products (Zr, Mo, Tc, Ru, Rh, Te, and Pd) which remain in the iron-based cladding hulls. Zirconium from the uranium fuel alloy (U-10Zr) is also deposited on the hulls and forms Fe-Zr intermetallics which incorporate the noble metals as well as residual actinides during processing. Hence, Zr has been chosen as the primary indicator for consistency of the metal waste. Recently, the first production-scale metal waste ingot was generated and sampled to monitor Zr content for Fe-Zr intermetallic phase formation and validation of processing conditions. Chemical assay of the metal waste ingot revealed a homogeneous distribution of the noble metal fission products as well as the primary fuel constituents U and Zr. Microstructural characterization of the ingot confirmed the immobilization of the noble metals in the Fe-Zr intermetallic phase.

  7. PROCESSING OF URANIUM-METAL-CONTAINING FUEL ELEMENTS

    DOEpatents

    Moore, R.H.

    1962-10-01

    A process is given for recovering uranium from neutronbombarded uranium- aluminum alloys. The alloy is dissolved in an aluminum halide--alkali metal halide mixture in which the halide is a mixture of chloride and bromide, the aluminum halide is present in about stoichiometric quantity as to uranium and fission products and the alkali metal halide in a predominant quantity; the uranium- and electropositive fission-products-containing salt phase is separated from the electronegative-containing metal phase; more aluminum halide is added to the salt phase to obtain equimolarity as to the alkali metal halide; adding an excess of aluminum metal whereby uranium metal is formed and alloyed with the excess aluminum; and separating the uranium-aluminum alloy from the fission- productscontaining salt phase. (AEC)

  8. Method for preparing metal powder, device for preparing metal powder, method for processing spent nuclear fuel

    DOEpatents

    Park, Jong-Hee [Clarendon Hills, IL

    2011-11-29

    A method for producing metal powder is provided the comprising supplying a molten bath containing a reducing agent, contacting a metal oxide with the molten bath for a time and at a temperature sufficient to reduce the metal in the metal oxide to elemental metal and produce free oxygen; and isolating the elemental metal from the molten bath.

  9. Metallography and fuel cladding chemical interaction in fast flux test facility irradiated metallic U-10Zr MFF-3 and MFF-5 fuel pins

    NASA Astrophysics Data System (ADS)

    Carmack, W. J.; Chichester, H. M.; Porter, D. L.; Wootan, D. W.

    2016-05-01

    The Mechanistic Fuel Failure (MFF) series of metal fuel irradiations conducted in the Fast Flux Test Facility (FFTF) provides an important comparison between data generated in the Experimental Breeder Reactor (EBR-II) and that expected in a larger-scale fast reactor. The MFF fuel operated with a peak cladding temperature at the top of the fuel column, but developed peak burnup at the centerline of the core. This places the peak fuel temperature midway between the core center and the top of fuel, lower in the fuel column than in EBR-II experiments. Data from the MFF-3 and MFF-5 assemblies are most comparable to the data obtained from the EBR-II X447 experiment. The two X447 pin breaches were strongly influenced by fuel/cladding chemical interaction (FCCI) at the top of the fuel column. Post irradiation examination data from MFF-3 and MFF-5 are presented and compared to historical EBR-II data.

  10. Nitrogen-doped graphene as efficient metal-free electrocatalyst for oxygen reduction in fuel cells.

    PubMed

    Qu, Liangti; Liu, Yong; Baek, Jong-Beom; Dai, Liming

    2010-03-23

    Nitrogen-doped graphene (N-graphene) was synthesized by chemical vapor deposition of methane in the presence of ammonia. The resultant N-graphene was demonstrated to act as a metal-free electrode with a much better electrocatalytic activity, long-term operation stability, and tolerance to crossover effect than platinum for oxygen reduction via a four-electron pathway in alkaline fuel cells. To the best of our knowledge, this is the first report on the use of graphene and its derivatives as metal-free catalysts for oxygen reduction. The important role of N-doping to oxygen reduction reaction (ORR) can be applied to various carbon materials for the development of other metal-free efficient ORR catalysts for fuel cell applications, even new catalytic materials for applications beyond fuel cells.

  11. Determination of a Jet Fuel Metal Deactivator by High Performance Liquid Chromatography

    DTIC Science & Technology

    1983-06-01

    column packings, and sensitive low dead volume detectors have catapulted HPLC into a rapidly maturing and valuable complement to gas chromatography ...be a gas or liquid; and a stationary phase, which may be either a liquid or a solid. The form of chromatography used in this research was partition...AFWAL-TR-82-21 28 1 1- 0 • DETERMINATION OF A JET FUEL METAL DEACTIVATOR BY HIGH PERFORMANCE LIQUID CHROMATOGRAPHY Paul C. Hayes, Jr. Fuels Branch

  12. Irradiation experiment on fast reactor metal fuels containing minor actinides up to 7 at.% burnup

    SciTech Connect

    Ohta, H.; Yokoo, T.; Ogata, T.; Inoue, T.; Ougier, M.; Glatz, J.P.; Fontaine, B.; Breton, L.

    2007-07-01

    Fast reactor metal fuels containing minor actinides (MAs: Np, Am, Cm) and rare earths (REs) have been irradiated in the fast reactor PHENIX. In this experiment, four types of fuel alloys, U-19Pu-10Zr, U-19Pu-10Zr-2MA-2RE, U-19Pu-10Zr-5MA-5RE and U-19Pu-10Zr-5MA (wt.%), are loaded into part of standard metal fuel stacks. The postirradiation examinations will be conducted at {approx}2.4, {approx}7 and {approx}11 at.% burnup. As for the low-burnup fuel pins, nondestructive postirradiation tests have already been performed and the fuel integrity was confirmed. Furthermore, the irradiation experiment for the intermediate burnup goal of {approx}7 at.% was completed in July 2006. For the irradiation period of 356.63 equivalent full-power days, the neutron flux level remained in the range of 3.5-3.6 x 10{sup 15} n/cm{sup 2}/s at the axial peak position. On the other hand, the maximum linear power of fuel alloys decreased gradually from 305-315 W/cm (beginning of irradiation) to 250-260 W/cm (end of irradiation). The discharged peak burnup was estimated to be 6.59-7.23 at.%. The irradiation behavior of MA-containing metal fuels up to 7 at.% burnup was predicted using the ALFUS code, which was developed for U-Pu-Zr ternary fuel performance analysis. As a result, it was evaluated that the fuel temperature is distributed between {approx}410 deg. C and {approx}645 deg. C at the end of the irradiation experiment. From the stress-strain analysis based on the preliminarily employed cladding irradiation properties and the FCMI stress distribution history, it was predicted that a cladding strain of not more than 0.9% would appear. (authors)

  13. Method for producing hydrocarbon fuels from heavy polynuclear hydrocarbons by use of molten metal halide catalyst

    DOEpatents

    Gorin, Everett

    1979-01-01

    In a process for hydrocracking heavy polynuclear carbonaceous feedstocks to produce lighter hydrocarbon fuels by contacting the heavy feedstocks with hydrogen in the presence of a molten metal halide catalyst, thereafter separating at least a substantial portion of the carbonaceous material associated with the reaction mixture from the spent molten metal halide and thereafter regenerating the metal halide catalyst, an improvement comprising contacting the spent molten metal halide catalyst after removal of a major portion of the carbonaceous material therefrom with an additional quantity of hydrogen is disclosed.

  14. Processing and fabrication of mixed uranium/refractory metal carbide fuels with liquid-phase sintering

    NASA Astrophysics Data System (ADS)

    Knight, Travis W.; Anghaie, Samim

    2002-11-01

    Optimization of powder processing techniques were sought for the fabrication of single-phase, solid-solution mixed uranium/refractory metal carbide nuclear fuels - namely (U, Zr, Nb)C. These advanced, ultra-high temperature nuclear fuels have great potential for improved performance over graphite matrix, dispersed fuels tested in the Rover/NERVA program of the 1960s and early 1970s. Hypostoichiometric fuel samples with carbon-to-metal ratios of 0.98, uranium metal mole fractions of 5% and 10%, and porosities less than 5% were fabricated. These qualities should provide for the longest life and highest performance capability for these fuels. Study and optimization of processing methods were necessary to provide the quality assurance of samples for meaningful testing and assessment of performance for nuclear thermal propulsion applications. The processing parameters and benefits of enhanced sintering by uranium carbide liquid-phase sintering were established for the rapid and effective consolidation and formation of a solid-solution mixed carbide nuclear fuel.

  15. Alkaline polymer electrolyte fuel cells completely free from noble metal catalysts

    PubMed Central

    Lu, Shanfu; Pan, Jing; Huang, Aibin; Zhuang, Lin; Lu, Juntao

    2008-01-01

    In recent decades, fuel cell technology has been undergoing revolutionary developments, with fundamental progress being the replacement of electrolyte solutions with polymer electrolytes, making the device more compact in size and higher in power density. Nowadays, acidic polymer electrolytes, typically Nafion, are widely used. Despite great success, fuel cells based on acidic polyelectrolyte still depend heavily on noble metal catalysts, predominantly platinum (Pt), thus increasing the cost and hampering the widespread application of fuel cells. Here, we report a type of polymer electrolyte fuel cells (PEFC) employing a hydroxide ion-conductive polymer, quaternary ammonium polysulphone, as alkaline electrolyte and nonprecious metals, chromium-decorated nickel and silver, as the catalyst for the negative and positive electrodes, respectively. In addition to the development of a high-performance alkaline polymer electrolyte particularly suitable for fuel cells, key progress has been achieved in catalyst tailoring: The surface electronic structure of nickel has been tuned to suppress selectively the surface oxidative passivation with retained activity toward hydrogen oxidation. This report of a H2–O2 PEFC completely free from noble metal catalysts in both the positive and negative electrodes represents an important advancement in the research and development of fuel cells.

  16. The Hanford spent nuclear metal fuel multi-canister overpack and vacuum drying & hot conditioning process

    SciTech Connect

    Goldmann, L.H.; Irwin, J.J.; Miska, C.R.

    1996-12-31

    Nuclear production reactors operated at the U.S. Department of Energy`s Hanford Site from 1944 until 1988 to produce plutonium. Most of the irradiated fuel from these reactors was processed onsite to separate and recover the plutonium. When the processing facilities were closed in 1992, about 1,900 metric tons of unprocessed irradiated fuel remained in storage. Additional fuel was irradiated for research purposes or was shipped to the Hanford Site from offsite reactor facilities for storage or recovery of nuclear materials. The fuel inventory now in storage at the Hanford Site is predominantly N Reactor irradiated fuel, a metallic uranium alloy that is coextruded into zircaloy-2 cladding. The Spent Nuclear Fuel Project has committed to an accelerated schedule for removing spent nuclear fuel from the Hanford Site K Basins to a new interim storage facility in the 200 Area. The Westinghouse Hanford Company has developed an integrated process to deal with the K Basin spent fuel inventory. The process consists of cleaning the fuel, packaging it into MCOs, vacuum drying it at the K Basins, then transporting it to the Canister Storage Building for staging, hot conditioning, and interim storage. This presentation describes the MCO function, design, and life-cycle, including an overview of the vacuum drying and hot conditioning processes.

  17. Nano-structured noble metal catalysts based on hexametallate architecture for the reforming of hydrocarbon fuels

    DOEpatents

    Gardner, Todd H.

    2015-09-15

    Nano-structured noble metal catalysts based on hexametallate lattices, of a spinel block type, and which are resistant to carbon deposition and metal sulfide formation are provided. The catalysts are designed for the reforming of hydrocarbon fuels to synthesis gas. The hexametallate lattices are doped with noble metals (Au, Pt, Rh, Ru) which are atomically dispersed as isolated sites throughout the lattice and take the place of hexametallate metal ions such as Cr, Ga, In, and/or Nb. Mirror cations in the crystal lattice are selected from alkali metals, alkaline earth metals, and the lanthanide metals, so as to reduce the acidity of the catalyst crystal lattice and enhance the desorption of carbon deposit forming moieties such as aromatics. The catalysts can be used at temperatures as high as 1000.degree. C. and pressures up to 30 atmospheres. A method for producing these catalysts and applications of their use also is provided.

  18. Conducting polymer-coated corrosion resistant metallic bipolar plates for proton exchange membrane fuel cells

    NASA Astrophysics Data System (ADS)

    Joseph, Shine

    2005-11-01

    Concerns over depleting stocks of natural resources and a growing awareness of the environmental damage caused by widespread burning of fossil fuels, and more energy demands brought the idea of alternative energy systems. Proton Exchange Membrane (PEM) fuel cells are one of the fast growing alternative energy technologies. PEM fuel cells generate electricity from an electrochemical reaction between hydrogen and oxygen and produce electricity, a small amount of heat and water and therefore, they are environmentally friendly. Fuel cells are more efficient than internal combustion engines and operate continuously as long as fuel is supplied from an external tank. Fuel cells in stacks are used for most applications because the current output of a PEM fuel cell is around 0.3--0.5 A/cm2. In fuel cell stacks, bipolar plates combine two cells in series with anode and cathode of adjacent cells. The main functions of bipolar plates are electron and gas transport. Bipolar plates are major components in weight and volume of the PEM fuel cell stack and are a significant contributor to the stack cost. The bipolar plate is therefore a key component if power density is to increase and cost to come down. Bipolar plate material should be corrosion resistant, conductive, gas impermeable, light weight (mobile applications) and economical. Graphite plates are used for bipolar plate applications but they are expensive, are brittle to make in thin plates with gas channels on sides, have high manufacturing cost and are gas permeable if too thin. Metals are preferable for bipolar plate application because of better mechanical properties, higher electrical conductivity, lower gas permeability and low cost. In this work Al 6061 and 304 stainless steel alloys are the materials selected for bipolar plates. These metals form non-conductive surface oxides in a PEM fuel cell environment and cause a high contact resistance. This internal resistance lowers the efficiency of PEM fuel cell system. In

  19. Liquid Metal Bond for Improved Heat Transfer in LWR Fuel Rods

    SciTech Connect

    Donald Olander

    2005-08-24

    A liquid metal (LM) consisting of 1/3 weight fraction each of Pb, Sn, and Bi has been proposed as the bonding substance in the pellet-cladding gap in place of He. The LM bond eliminates the large AT over the pre-closure gap which is characteristic of helium-bonded fuel elements. Because the LM does not wet either UO2 or Zircaloy, simply loading fuel pellets into a cladding tube containing LM at atmospheric pressure leaves unfilled regions (voids) in the bond. The HEATING 7.3 heat transfer code indicates that these void spaces lead to local fuel hot spots.

  20. Fission product release phenomena during core melt accidents in metal fueled heavy water reactors

    SciTech Connect

    Ellison, P G; Hyder, M L; Monson, P R; Randolph, H W; Hagrman, D L; McClure, P R; Leonard, M T

    1990-01-01

    The phenomena that determine fission product release rates from a core melting accident in a metal-fueled, heavy water reactor are described in this paper. This information is obtained from the analysis of the current metal fuel experimental data base and from the results of analytical calculations. Experimental programs in place at the Savannah River Site are described that will provide information to resolve uncertainties in the data base. The results of the experiments will be incorporated into new severe accident computer codes recently developed for this reactor design. 47 refs., 4 figs.

  1. Accommodation of unprotected accidents by inherent safety design features in metallic and oxide-fueled LMFBRs

    SciTech Connect

    Cahalan, J.E.; Sevy, R.H.; Su, S.F.

    1985-01-01

    This paper presents the results of a study of the effectivness of intrinsic design features to mitigate the consequences of unprotected accidents in metallic and oxide-fueled LMFBRs. The accidents analyzed belong to the class generally considered to lead to core disruption; unprotected loss-of-flow (LOF) and transient over-power (TOP). Results of the study demonstrate the potential for design features to meliorate accident consequences, and in some cases to render them benign. Emphasis is placed on the relative performance of metallic and oxide-fueled core designs.

  2. Metallic fast reactor fuel fabrication for the global nuclear energy partnership

    NASA Astrophysics Data System (ADS)

    Burkes, Douglas E.; Fielding, Randall S.; Porter, Douglas L.

    2009-07-01

    Fast reactors are once again being considered for nuclear power generation, in addition to transmutation of long-lived fission products resident in spent nuclear fuels. This re-consideration follows with intense developmental programs for both fuel and reactor design. One of the two leading candidates for next generation fast reactor fuel is metal alloys, resulting primarily from the successes achieved in the 1960s to early 1990s with both the experimental breeding reactor-II and the fast flux test facility. The goal of the current program is to develop and qualify a nuclear fuel system that performs all of the functions of a conventional, fast-spectrum nuclear fuel while destroying recycled actinides, thereby closing the nuclear fuel cycle. In order to meet this goal, the program must develop efficient and safe fuel fabrication processes designed for remote operation. This paper provides an overview of advanced casting processes investigated in the past, and the development of a gaseous diffusion calculation that demonstrates how straightforward process parameter modification can mitigate the loss of volatile minor actinides in the metal alloy melt.

  3. Corrosion and Protection of Metallic Interconnects in Solid Oxide Fuel Cells

    SciTech Connect

    Yang, Z Gary; Stevenson, Jeffry W.; Singh, Prabhakar

    2007-12-09

    Energy security and increased concern over environmental protection have spurred a dramatic world-wide growth in research and development of fuel cells, which electrochemically convert incoming fuel into electricity with no or low pollution. Fuel cell technology has become increasingly attractive to a number of sectors, including utility, automotive, and defense industries. Among the various types of fuel cells, solid oxide fuel cells (SOFCs) operate at high temperature (typically 650-1,000 C) and have advantages in terms of high conversion efficiency and the flexibility of using hydrocarbon fuels, in addition to hydrogen. The high temperature operation, however, can lead to increased mass transport and interactions between the surrounding environment and components that are required to be stable during a lifetime of thousands of hours and up to hundreds of thermal cycles. For stacks with relatively low operating temperatures (<800 C), the interconnects that are used to electrically connect a number of cells in series are typically made from cost-effective metals or alloys. The metallic interconnects must demonstrate excellent stability in a very challenging environment during SOFC operation, as they are simultaneously exposed to both an oxidizing (air) environment on the cathode side and a reducing environment (hydrogen or a reformed hydrocarbon fuel) on the anode side. Other challenges include the fact that water vapor is likely to be present in both of these environments, and the fuel is likely to contain impurities, such as sulfides. Since the fuel is usually a reformed hydrocarbon fuel, such as natural gas, coal gas, biogas, gasoline, etc., the interconnect is exposed to a wet carbonaceous environment at the anode side. Finally, the interconnect must be stable towards any adjacent components, such as electrodes, seals and electrical contact materials, with which it is in physical contact.

  4. Measuring the Noble Metal and Iodine Composition of Extracted Noble Metal Phase from Spent Nuclear Fuel Using Instrumental Neutron Activation Analysis

    SciTech Connect

    Palomares, R. I.; Dayman, Kenneth J.; Landsberger, Sheldon; Biegalski, Steven R.; Soderquist, Chuck Z.; Casella, Amanda J.; Brady Raap, Michaele C.; Schwantes, Jon M.

    2015-04-01

    Mass quantities of noble metal and iodine nuclides in the metallic noble metal phase extracted from spent fuel are measured using instrumental neutron activation analysis (NAA). Nuclide presence is predicted using fission yield analysis, and mass quantification is derived from standard gamma spectroscopy and radionuclide decay analysis. The nuclide compositions of noble metal phase derived from two dissolution methods, UO2 fuel dissolved in nitric acid and UO2 fuel dissolved in ammonium-carbonate and hydrogen-peroxide solution, are compared. Lastly, the implications of the rapid analytic speed of instrumental NAA are discussed in relation to potential nuclear forensics applications.

  5. Graphene supported non-precious metal-macrocycle catalysts for oxygen reduction reaction in fuel cells

    NASA Astrophysics Data System (ADS)

    Choi, Hyun-Jung; Ashok Kumar, Nanjundan; Baek, Jong-Beom

    2015-04-01

    Fuel cells are promising alternative energy devices owing to their high efficiency and eco-friendliness. While platinum is generally used as a catalyst for the oxygen reduction reaction (ORR) in a typical fuel cell, limited reserves and prohibitively high costs limit its future use. The development of non-precious and durable metal catalysts is being constantly conceived. Graphene has been widely used as a substrate for metal catalysts due to its unique properties, thus improving stability and ORR activities. In this feature, we present an overview on the electrochemical characteristics of graphene supported non-precious metal containing macrocycle catalysts that include metal porphyrin and phthalocyanine derivatives. Suggested research and future development directions are discussed.

  6. Creep resistant, metal-coated LiFeO.sub.2 anodes for molten carbonated fuel cells

    DOEpatents

    Khandkar, Ashok C.

    1994-01-01

    A porous, creep-resistant, metal-coated, LiFeO.sub.2 ceramic electrode for fuel cells is disclosed. The electrode is particularly useful for molten carbonate fuel cells (MCFC) although it may have utilities in solid oxide fuel cells (SOFC) as well.

  7. Creep resistant, metal-coated LiFeO[sub 2] anodes for molten carbonated fuel cells

    DOEpatents

    Khandkar, A.C.

    1994-08-23

    A porous, creep-resistant, metal-coated, LiFeO[sub 2] ceramic electrode for fuel cells is disclosed. The electrode is particularly useful for molten carbonate fuel cells (MCFC) although it may have utilities in solid oxide fuel cells (SOFC) as well. 11 figs.

  8. Evaluation of the use of metal alloy fuels in pressurized water reactors. Progress report, September 1989--November 1990

    SciTech Connect

    Not Available

    1990-12-31

    The project concentrated on model development. Reactor physics modeling involved establishing accurate models with PC versions of COMBINE and VENTURE. Fuel performance analysis will start with METAL- LIFE. In order to justify the change of fuel to metal alloy, large benefits will have to be found; the cost benefit reported is not sufficient. The fuel pin will be annular and contact the clad; the clad thickness will force the fuel to grow toward the central hole. This report reports: design improvements, neutronic model development, COBRA modifications, reactor kinetics model development, RELAP code, and fuel performance.

  9. Liquid Metal Anode for JP-8 Fuel Cell

    DTIC Science & Technology

    2009-01-15

    IV > 20 Po Group IV > 20 Hg Group IV > 20 17 Figure 2 CellTech Power liquid tin anode SOFC Ag Group IV > 20 The electrochemistry...have higher specific power compared to Westinghouse-Siemens type tubular fuel cells. But planar SOFC for direct oxidation of hydrocarbons such as JP...the LTA- SOFC for military power generation. The Gen 3.1 cell was designed for a battery charger and other sub-kilowatt portable power missions. The

  10. Burnup Predictions for Metal Fuel Tests in the Fast Flux Test Facility

    SciTech Connect

    Wootan, David W.; Nelson, Joseph V.

    2012-06-01

    The Fast Flux Test Facility (FFTF) is the most recent Liquid Metal Reactor (LMR) to be designed, constructed, and operated by the U.S. Department of Energy (DOE). The FFTF operated successfully from initial startup in 1980 through the end of the last operating cycle in March, 1992. A variety of fuel tests were irradiated in FFTF to provide performance data over a range of conditions. The MFF-3 and MFF-5 tests were U10Zr metal fuel tests with HT9 cladding. The MFF-3 and MFF-5 tests were both aggressive irradiation tests of U10Zr metal fuel pins with HT9 cladding that were prototypic of full scale LMR designs. MFF-3 was irradiated for 726 Effective Full Power Days (EFPD), starting from Cycle 10C1 (from November 1988 through March 1992), and MFF-5 was irradiated for 503 EFPD starting from Cycle 11B1 (from January 1990 through March 1992). A group of fuel pins from these two tests are undergoing post irradiation examination at the Idaho National Laboratory (INL) for the Fuel Cycle Research and Development Program (FCRD). The generation of a data package of key information on the irradiation environment and current pin detailed compositions for these tests is described. This information will be used in interpreting the results of these examinations.

  11. Corrosion-resistant fuel cladding allow for liquid metal fast breeder reactors

    DOEpatents

    Brehm, Jr., William F.; Colburn, Richard P.

    1982-01-01

    An aluminide coating for a fuel cladding tube for LMFBRs (liquid metal fast breeder reactors) such as those using liquid sodium as a heat transfer agent. The coating comprises a mixture of nickel-aluminum intermetallic phases and presents good corrosion resistance to liquid sodium at temperatures up to 700.degree. C. while additionally presenting a barrier to outward diffusion of .sup.54 Mn.

  12. Comparison of the effect of insulating blockages on metal and oxide fuel elements

    SciTech Connect

    Tilbrook, R.W.; Dever, D.J.

    1988-01-01

    The safety philosophy of the new liquid-metal reactor (LMR) plant designs is oriented toward inherent protection against loss of coolable geometry and other entries to core disruption. One potential entry is via propagation of local faults. The basic event in all local sequences is cladding failure, irrespective of initiator. A model of a complete insulating blockage, i.e., total loss of heat transfer from the cladding surface due to any cause, was developed for a range of insulated arcs. The internal properties represented either metal or oxide fuels, both irradiated to a condition that closed the fuel-clad gap. The advantage of the high conductivity of the metal fuel is clearly evident; the maximum cladding temperatures are considerably lower than for the oxide elements with the same circumferential blockage extent. Also, the minimum cladding temperature at the opposite side of the element is higher for the metal fuel, thus providing more uniform heat rejection from the unblocked portion of the cladding. The cladding temperatures at the edge of the blockages for the oxide elements are directly proportional to the blockage angle, indicating that the cladding is the main path for heat rejection.

  13. Development and analysis of a metal-fueled accelerator-driven burner

    SciTech Connect

    Lypsch, F.; Hill, R.N.

    1994-08-01

    The purpose of this paper is to compare the safety characteristics of an accelerator driven metal fueled fast system to a critical core on a consistent basis to determine how these characteristics are affected solely by subcritically of the system. To accomplish this an accelerator proton beam/tungsten neutron source model is surrounded by a subcritical blanket using metallic fuel and sodium as coolant. The consequences of typical accident transients, namely unprotected transient overpower (TOP), loss of heat sink (LOHS), and loss of flow (LOP) were calculated for the hybrid system and compared to corresponding results for a metal-fueled fast reactor. Results indicate that the subcritical system exhibits superior performance for TOP (reactivity-induced) transits; however, only in the critical system are reactivity feedbacks able to cause passive shutdown in the LOHS ad LOP events. Therefore, for a full spectrum of accident initiators considered, the overall safety behavior of accelerator-driven metal-fueled systems can neither be concluded to be worse nor to be better than advanced reactor designs which rely on passive safety features.

  14. Gas Generation from K East Basin Sludges and Irradiated Metallic Uranium Fuel Particles Series III Testing

    SciTech Connect

    Schmidt, Andrew J.; Delegard, Calvin H.; Bryan, Samuel A.; Elmore, Monte R.; Sell, Rachel L.; Silvers, Kurt L.; Gano, Susan R.; Thornton, Brenda M.

    2003-08-01

    The path forward for managing of Hanford K Basin sludge calls for it to be packaged, shipped, and stored at T Plant until final processing at a future date. An important consideration for the design and cost of retrieval, transportation, and storage systems is the potential for heat and gas generation through oxidation reactions between uranium metal and water. This report, the third in a series (Series III), describes work performed at the Pacific Northwest National Laboratory (PNNL) to assess corrosion and gas generation from irradiated metallic uranium particles (fuel particles) with and without K Basin sludge addition. The testing described in this report consisted of 12 tests. In 10 of the tests, 4.3 to 26.4 g of fuel particles of selected size distribution were placed into 60- or 800-ml reaction vessels with 0 to 100 g settled sludge. In another test, a single 3.72-g fuel fragment (i.e., 7150-mm particle) was placed in a 60 ml reaction vessel with no added sludge. The twelfth test contained only sludge. The fuel particles were prepared by crushing archived coupons (samples) from an irradiated metallic uranium fuel element. After loading the sludge materials (whether fuel particles, mixtures of fuel particles and sludge, or sludge-only) into reaction vessels, the solids were covered with an excess of K Basin water, the vessels closed and connected to a gas measurement manifold, and the vessels back-flushed with inert neon cover gas. The vessels were then heated to a constant temperature. The gas pressures and temperatures were monitored continuously from the times the vessels were purged. Gas samples were collected at various times during the tests, and the samples analyzed by mass spectrometry. Data on the reaction rates of uranium metal fuel particles with water as a function of temperature and particle size were generated. The data were compared with published studies on metallic uranium corrosion kinetics. The effects of an intimate overlying sludge layer

  15. Metal-catalyst-free carbohydrazide fuel cells with three-dimensional graphene anodes.

    PubMed

    Qi, Ji; Benipal, Neeva; Wang, Hui; Chadderdon, David J; Jiang, Yibo; Wei, Wei; Hu, Yun Hang; Li, Wenzhen

    2015-04-13

    As a potential solution to concerns on sustainable energy, the wide spread commercialization of fuel cell has long been hindered by limited reserves and relatively high costs of metal catalysts. 3D graphene, a carbon-only catalyst prepared by reduction of carbon monoxide with lithium oxide, is found to electrochemically catalyze carbohydrazide oxidation reaction efficiently. A prototype of a completely metal-catalyst-free anion exchange membrane fuel cell (AEMFC) with a 3D graphene anode catalyst and an N-doped CNT (N-CNT) cathode catalyst generate a peak power density of 24.9 mW cm(-2) . The average number of electrons electrochemically extracted from one carbohydrazide molecule is 4.9, indicating the existence of CN bond activation, which is a key factor contributing to high fuel utilization efficiency.

  16. Investigation of novel electrolyte systems for advanced metal/air batteries and fuel cells

    NASA Astrophysics Data System (ADS)

    Ye, Hui

    It is a worldwide challenge to develop advanced green power sources for modern portable devices, transportation and stationary power generation. Metal/air batteries and fuel cells clearly stand out in view of their high specific energy, high energy efficiency and environment-friendliness. Advanced metal/air batteries based on metal ion conductors and proton exchange membrane (PEM) fuel cells operated at elevated temperatures (>120°C) can circumvent the limitations of current technologies and bring considerable advantages. The key is to develop suitable electrolytes to enable these new technologies. In this thesis research, investigation of novel electrolytes systems for advanced metal/air batteries and PEM fuel cells is conducted. Novel polymer gel electrolyte systems, [metal salt/ionic liquid/polymer] and [metal salt/liquid polyether/polymer] are prepared. Such systems contain no volatile solvents, conduct metal ions (Li+ or Zn 2+) with high ionic conductivity, possess wide electrochemical stability windows, and exhibit wide operating temperature ranges. They promise to enable non-aqueous, all-solid-state, thin-film Li/air batteries and Zn/air batteries. They are advantageous for application in other battery systems as well, such as rechargeable lithium and lithium ion batteries. In the case of proton exchange membranes, polymer gel electrolyte systems [acid/ionic liquid/polymer] are prepared. Especially, H3PO4/PMIH2PO 4/PBI is demonstrated as prospective proton exchange membranes for PEM fuel cells operating at elevated temperatures. Comprehensive electrochemical characterization, thermal analysis (TGA and DSC) and spectroscopy analysis (NMR and FTIR) are carried out to investigate these novel electrolyte systems and their ion transport mechanisms. The design and synthesis of novel ionic liquids and electrolyte systems based on them for advantageous application in various electrochemical power sources are highlighted in this work.

  17. Metal Interconnects for Solid Oxide Fuel Cell Power Systems

    SciTech Connect

    S. Elangovan

    2006-04-01

    Interconnect development is identified by the US Department of energy as a key technical area requiring focused research to meet the performance and cost goals under the Solid State Energy Conversion Alliance initiative. In the Phase I SECA Core Technology Program, Ceramatec investigated a commercial ferritic stainless steel composition for oxidation resistance properties by measuring the weight gain when exposed to air at the fuel cell operating temperature. A pre-treatment process that results in a dense, adherent scale was found to reduce the oxide scale growth rate significantly. A process for coating the surface of the alloy in order to reduce the in-plane resistance and potentially inhibit chromium oxide evaporation was also identified. The combination of treatments provided a very low resistance through the scale. The resistance measured was as low as 10 milliohm-cm2 at 750 C in air. The oxide scale was also found to be stable in humidified air at 750 C. The resistance value was stable over several thermal cycles. A similar treatment and coating for the fuel side of the interconnect also showed an exceptionally low resistance of one milliohm-cm2 in humidified hydrogen at 750 c, and was stable through multiple thermal cycles. Measurement of interconnect resistance when it was exposed to both air and humidified hydrogen on opposite sides also showed low, stable resistance after additional modification to the pre-treatment process. Resistance stacks, using an interconnect stack with realistic gas flows, also provided favorable results. Chromium evaporation issue however requires testing of fuel stacks and was outside of the scope of this project. based on results to-date, the alloy selection and the treatment processes appear to be well suited for SOFC interconnect application.

  18. Determination of Uranium Metal Concentration in Irradiated Fuel Storage Basin Sludge Using Selective Dissolution

    SciTech Connect

    Delegard, Calvin H.; Sinkov, Sergey I.; Chenault, Jeffrey W.; Schmidt, Andrew J.; Welsh, Terri L.; Pool, Karl N.

    2014-03-01

    Uranium metal corroding in water-saturated sludges now held in the US Department of Energy Hanford Site K West irradiated fuel storage basin can create hazardous hydrogen atmospheres during handling, immobilization, or subsequent transport and storage. Knowledge of uranium metal concentration in sludge thus is essential to safe sludge management and process design, requiring an expeditious routine analytical method to detect uranium metal concentrations as low as 0.03 wt% in sludge even in the presence of 30 wt% or higher total uranium concentrations.

  19. Stabilized metal nanoparticles from organometallic precursors for low temperature fuel cells.

    PubMed

    Ramirez-Meneses, E; Dominguez-Crespo, M A; Torres-Huerta, A M

    2013-01-01

    In this work, a review of articles and patents related to the utilization of colloidal metal nanoparticles produced by the decomposition of organometallic precursors as supported electrocatalysts in different electrochemical reactions including hydrogen evolution reaction (HER), oxygen reduction reaction (ORR) and methanol oxidation reaction (MOR) is discussed. In the case of stabilized metal nanoparticles, the kind of functional group contained in the stabilizer as well as the metal/stabilizer ratio, to evaluate the effect of particle size on the electrochemical performance, were also debated. Potential applications and perspectives of these electrocatalysts in proton exchange membrane fuel cells (PEMFC) are contended with reference to the role played by the coordination compounds and costs.

  20. A new code for predicting the thermo-mechanical and irradiation behavior of metallic fuels in sodium fast reactors

    NASA Astrophysics Data System (ADS)

    Karahan, Aydın; Buongiorno, Jacopo

    2010-01-01

    An engineering code to predict the irradiation behavior of U-Zr and U-Pu-Zr metallic alloy fuel pins and UO2-PuO2 mixed oxide fuel pins in sodium-cooled fast reactors was developed. The code was named Fuel Engineering and Structural analysis Tool (FEAST). FEAST has several modules working in coupled form with an explicit numerical algorithm. These modules describe fission gas release and fuel swelling, fuel chemistry and restructuring, temperature distribution, fuel-clad chemical interaction, and fuel and clad mechanical analysis including transient creep-fracture for the clad. Given the fuel pin geometry, composition and irradiation history, FEAST can analyze fuel and clad thermo-mechanical behavior at both steady-state and design-basis (non-disruptive) transient scenarios. FEAST was written in FORTRAN-90 and has a simple input file similar to that of the LWR fuel code FRAPCON. The metal-fuel version is called FEAST-METAL, and is described in this paper. The oxide-fuel version, FEAST-OXIDE is described in a companion paper. With respect to the old Argonne National Laboratory code LIFE-METAL and other same-generation codes, FEAST-METAL emphasizes more mechanistic, less empirical models, whenever available. Specifically, fission gas release and swelling are modeled with the GRSIS algorithm, which is based on detailed tracking of fission gas bubbles within the metal fuel. Migration of the fuel constituents is modeled by means of thermo-transport theory. Fuel-clad chemical interaction models based on precipitation kinetics were developed for steady-state operation and transients. Finally, a transient intergranular creep-fracture model for the clad, which tracks the nucleation and growth of the cavities at the grain boundaries, was developed for and implemented in the code. Reducing the empiricism in the constitutive models should make it more acceptable to extrapolate FEAST-METAL to new fuel compositions and higher burnup, as envisioned in advanced sodium reactors

  1. Magnetron sputtering of metallic coatings onto elastomeric substrates for a decrease in fuel permeation rate

    NASA Astrophysics Data System (ADS)

    Myntti, Matthew F.

    The purpose of this research was to investigate the application of a metallic coating by magnetron sputtering onto elastomeric substrates, as an inhibiting layer to permeation transport. The metallic coatings which were deposited were aluminum, titanium, and copper. The substrates used were NBR, FVMQ, and FKM elastomers. The permeating fluids were ASTM Fuel C, isooctane, and toluene. The magnetron sputtering properties of these metallic elements were unique to each material, with the titanium sputtering rate being very low. The sputtering rates of these materials correlated well with their sublimation temperature. It was found that some of the metallic particles which were sputtered onto the substrates, implanted into the surface of the elastomeric membranes, with the total amount and distance of implantation being related to the density of the substrate material. The permeation of these solvents through the composite materials was reduced by the presence of these coatings with the reduction in permeation rate ranging from 12 to 25% for Fuel C. The pervaporation properties of these substrates were also evaluated. It was found from this analysis that for the FVMQ and NBR substrates, the permeation rate of the permeating solute molecules was proportional to the size of the permeation molecule. The substrate materials were not significantly stiffened by the addition of the thin metallic coatings. The coated materials were cohesive and well adhered, as determined by stretching of the substrate materials with the metallic layer in place. Upon stretching, there was no evidence of damage to the metallic coating.

  2. Assessment on the occupational exposure of urban public bus drivers to bioaccessible trace metals through resuspended fraction of settled bus dust.

    PubMed

    Gao, Peng; Liu, Sa; Ye, Wenyuan; Lin, Nan; Meng, Ping; Feng, Yujie; Zhang, Zhaohan; Cui, Fuyi; Lu, Binyu; Xing, Baoshan

    2015-03-01

    Limited information is available on the bioaccessible fraction of trace metals in the resuspended fraction of settled bus dust in order to estimate bus drivers' occupational exposure. In this study, 45 resuspended fraction of settled dust samples were collected from gasoline and compressed natural gas (CNG) powered buses and analyzed for trace metals and their fraction concentrations using a three-step sequential extraction procedure. Experimental results showed that zinc (Zn) had the greatest bioaccessible fraction, recorded as an average of 608.53 mg/kg, followed in order of decreasing concentration by 129.80 mg/kg lead (Pb), 56.77 mg/kg copper (Cu), 34.03 mg/kg chromium (Cr), 22.05 mg/kg nickel (Ni), 13.17 mg/kg arsenic (As) and 2.77 mg/kg cadmium (Cd). Among the three settled bus dust exposure pathways, ingestion was the main route. Total exposure hazard index (HIt) for non-carcinogenic effect trace metals was lower than the safety level of 1. The incremental lifetime cancer risk (ILCR) for drivers was estimated for trace metal exposure. Pb and Ni presented relatively high potential risks in the non-carcinogenic and potentially carcinogenic health assessment for all drivers. ILCR was in the range of 1.84E-05 to 7.37E-05 and 1.74E-05 to 6.95E-05 for gasoline and CNG buses, respectively.

  3. Nanostructure of Metallic Particles in Light Water Reactor Used Nuclear Fuel

    SciTech Connect

    Buck, Edgar C.; Mausolf, Edward J.; Mcnamara, Bruce K.; Soderquist, Chuck Z.; Schwantes, Jon M.

    2015-03-11

    The extraordinary nano-structure of metallic particles in light water reactor fuels points to possible high reactivity through increased surface area and a high concentration of high energy defect sites. We have analyzed the metallic epsilon particles from a high burn-up fuel from a boiling water reactor using transmission electron microscopy and have observed a much finer nanostructure in these particles than has been reported previously. The individual round particles that varying in size between ~20 and ~50 nm appear to consist of individual crystallites on the order of 2-3 nm in diameter. It is likely that in-reactor irradiation induce displacement cascades results in the formation of the nano-structure. The composition of these metallic phases is variable yet the structure of the material is consistent with the hexagonal close packed structure of epsilon-ruthenium. These findings suggest that unusual catalytic behavior of these materials might be expected, particularly under accident conditions.

  4. Development of new ferritic cladding materials for metal-fueled FBRs

    SciTech Connect

    Tokiwai, Moriyasu; Kako, Kenji ); Horie, Masaaki; Fujiwara, Yuukou )

    1992-01-01

    It is well known that the characteristics of metallic fuel (U-Zr, U-Pu-Zr alloy), such as high fissile density, high thermal conductivity, and harder neutron spectrum, enable the development of superior core performance and safety features based on the passive safety design of a liquid metal fast breeder reactor (LMFBR). For the higher performance of a metal fuel core, higher-strength and high-swelling-resistant cladding materials are required. Ferritic stainless steel is well known to be resistant to swelling up to very high fast neutron fluence, but the creep strength is not sufficient for the practical use as a cladding material. In this study, combinations of various strengthening techniques were applied to Fe-12% Cr ferritic stainless steels.

  5. Scoping studies of vapor behavior during a severe accident in a metal-fueled reactor

    SciTech Connect

    Spencer, B.W.; Marchaterre, J.F.

    1985-04-15

    Scoping calculations have been performed examining the consequences of fuel melting and pin failures for a reactivity-insertion type accident in a sodium-cooled, pool-type reactor fueled with a metal alloy fuel. The principal gas and vapor species released are shown to be Xe, Cs,and bond sodium contained within the fuel porosity. Fuel vapor pressure is insignificant, and there is no energetic fuel-coolant interaction for the conditions considered. Condensation of sodium vapor as it expands into the upper sodium pool in a jet mixing regime may occur as rapidly as the vapor emerges from the disrupted core (although reactor-material experiments are needed to confirm these high condensation rates). If the predictions of rapid direct-contact condensation can be verified experimentally for the sodium system, the implication is that the ability of vapor expansion to perform appreciable work on the system is largely eliminated. Furthermore, the ability of an expanding vapor bubble to transport fuel and fission product species to the cover gas region where they may be released to the containment is also largely eliminated. The radionuclide species except for fission gas are largely retained within the core and sodium pool.

  6. METAL INTERCONNECTS FOR SOLID OXIDE FUEL CELL POWER SYSTEMS

    SciTech Connect

    S. Elangovan; S. Balagopal; M. Timper; I. Bay; D. Larsen; J. Hartvigsen

    2003-10-01

    Interconnect development is identified by the U.S. Department of Energy as a key technical area requiring focused research to meet the performance and cost goals under the Solid State Energy Conversion Alliance initiative. In the Phase I SECA Core Technology Program, Ceramatec investigated a commercial ferritic stainless steel composition for oxidation resistance properties by measuring the weight gain when exposed to air at the fuel cell operating temperature. A pre-treatment process that results in a dense, adherent scale was found to reduce the oxide scale growth rate significantly. A process for coating the surface of the alloy in order to reduce the in-plane resistance and potentially inhibit chromium oxide evaporation was also identified. The combination of treatments provided a very low resistance through the scale. The resistance measured was as low as 10 milliohm-cm{sup 2} at 750 C in air. The oxide scale was found to be stable in humidified air at 750 C. The resistance value was stable over several thermal cycles. A similar treatment and coating for the fuel side of the interconnect also showed an exceptionally low resistance of one milliohm-cm{sup 2} in humidified hydrogen at 750 C, and was stable through multiple thermal cycles. Analysis of the scale after exposure to various atmospheres showed the presence of a stable composition. When exposed to a dual (air and hydrogen) atmosphere however, the scale composition contains a mixture of phases. Based on results to-date, the alloy selection and the treatment processes appear to be well suited for SOFC interconnect application.

  7. Metal hydride and pyrophoric fuel additives for dicyclopentadiene based hybrid propellants

    NASA Astrophysics Data System (ADS)

    Shark, Steven C.

    The purpose of this study is to investigate the use of reactive energetic fuel additives that have the potential to increase the combustion performance of hybrid rocket propellants in terms of solid fuel regression rate and combustion efficiency. Additives that can augment the combustion flame zone in a hybrid rocket motor by means of increased energy feedback to the fuel grain surface are of great interest. Metal hydrides have large volumetric hydrogen densities, which gives these materials high performance potential as fuel additives in terms of specifc impulse. The excess hydrogen and corresponding base metal may also cause an increase in the hybrid rocket solid fuel regression rate. Pyrophoric additives also have potential to increase the solid fuel regression rate by reacting more readily near the burning fuel surface providing rapid energy feedback. An experimental performance evaluation of metal hydride fuel additives for hybrid rocket motor propulsion systems is examined in this study. Hypergolic ignition droplet tests and an accelerated aging study revealed the protection capabilities of Dicyclopentadiene (DCPD) as a fuel binder, and the ability for unaided ignition. Static hybrid rocket motor experiments were conducted using DCPD as the fuel. Sodium borohydride (NabH4) and aluminum hydride (AlH3) were examined as fuel additives. Ninety percent rocket grade hydrogen peroxide (RGHP) was used as the oxidizer. In this study, the sensitivity of solid fuel regression rate and characteristic velocity (C*) efficiency to total fuel grain port mass flux and particle loading is examined. These results were compared to HTPB combustion performance as a baseline. Chamber pressure histories revealed steady motor operation in most tests, with reduced ignition delays when using NabH4 as a fuel additive. The addition of NabH4 and AlH3 produced up to a 47% and 85% increase in regression rate over neat DCPD, respectively. For all test conditions examined C* efficiency ranges

  8. REFORMULATION OF COAL-DERIVED TRANSPORTATION FUELS: SELECTIVE OXIDATION OF CARBON MONOXIDE ON METAL FOAM CATALYSTS

    SciTech Connect

    Paul Chin; Xiaolei Sun; George W. Roberts; Amornmart Sirijarhuphan; Sourabh Pansare; James G. Goodwin Jr; Richard W. Rice; James J. Spivey

    2005-06-01

    Hydrocarbon fuels must be reformed in a series of steps to provide hydrogen for use in proton exchange membrane fuel cells (PEMFCs). Preferential oxidation (PROX) is one method to reduce the CO concentration to less than 10 ppm in the presence of {approx}40% H{sub 2}, CO{sub 2}, and steam. This will prevent CO poisoning of the PEMFC anode. Structured supports, such as ceramic monoliths, can be used for the PROX reaction. Alternatively, metal foams offer a number of advantages over the traditional ceramic monolith.

  9. Application of fuel cell for pyrite and heavy metal containing mining waste

    NASA Astrophysics Data System (ADS)

    Keum, H.; Ju, W. J.; Jho, E. H.; Nam, K.

    2015-12-01

    Once pyrite and heavy metal containing mining waste reacts with water and air it produces acid mine drainage (AMD) and leads to the other environmental problems such as contamination of surrounding soils. Pyrite is the major source of AMD and it can be controlled using a biological-electrochemical dissolution method. By enhancing the dissolution of pyrite using fuel cell technology, not only mining waste be beneficially utilized but also be treated at the same time by. As pyrite-containing mining waste is oxidized in the anode of the fuel cell, electrons and protons are generated, and electrons moves through an external load to cathode reducing oxygen to water while protons migrate to cathode through a proton exchange membrane. Iron-oxidizing bacteria such as Acidithiobacillus ferrooxidans, which can utilize Fe as an electron donor promotes pyrite dissolution and hence enhances electrochemical dissolution of pyrite from mining waste. In this study mining waste from a zinc mine in Korea containing 17 wt% pyrite and 9% As was utilized as a fuel for the fuel cell inoculated with A. ferrooxidans. Electrochemically dissolved As content and chemically dissolved As content was compared. With the initial pH of 3.5 at 23℃, the dissolved As concentration increased (from 4.0 to 13 mg/L after 20 d) in the fuel cell, while it kept decreased in the chemical reactor (from 12 to 0.43 mg/L after 20 d). The fuel cell produced 0.09 V of open circuit voltage with the maximum power density of 0.84 mW/m2. Dissolution of As from mining waste was enhanced through electrochemical reaction. Application of fuel cell technology is a novel treatment method for pyrite and heavy metals containing mining waste, and this method is beneficial for mining environment as well as local community of mining areas.

  10. Metal based gas diffusion layers for enhanced fuel cell performance at high current densities

    NASA Astrophysics Data System (ADS)

    Hussain, Nabeel; Van Steen, Eric; Tanaka, Shiro; Levecque, Pieter

    2017-01-01

    The gas diffusion layer strongly influences the performance and durability of polymer electrolyte fuel cells. A major drawback of current carbon fiber based GDLs is the non-controlled variation in porosity resulting in a random micro-structure. Moreover, when subjected to compression these materials show significant reduction in porosity and permeability leading to water management problems and mass transfer losses within the fuel cell. This study investigated the use of uniform perforated metal sheets as GDLs in conjunction with microchannel flowfields. A metal sheet design with a pitch of 110 μm and a hole diameter of 60 μm in combination with an MPL showed superior performance in the high current density region compared to a commercially available carbon paper based GDL in a single cell environment. Fuel cell testing with different oxidants (air, heliox and oxygen) indicate that the metal sheet offers both superior diffusion and reduced flooding in comparison to the carbon based GDL. The presence of the MPL has been found to be critical to the functionality of the metal sheet suggesting that the MPL design may represent an important optimisation parameter for further improvements in performance.

  11. A review of inherent safety characteristics of metal alloy sodium-cooled fast reactor fuel against postulated accidents

    DOE PAGES

    Sofu, Tanju

    2015-04-01

    The thermal, mechanical, and neutronic performance of the metal alloy fast reactor fuel design complements the safety advantages of the liquid metal cooling and the pool-type primary system. Together, these features provide large safety margins in both normal operating modes and for a wide range of postulated accidents. In particular, they maximize the measures of safety associated with inherent reactor response to unprotected, double-fault accidents, and to minimize risk to the public and plant investment. High thermal conductivity and high gap conductance play the most significant role in safety advantages of the metallic fuel, resulting in a flatter radial temperaturemore » profile within the pin and much lower normal operation and transient temperatures in comparison to oxide fuel. Despite the big difference in melting point, both oxide and metal fuels have a relatively similar margin to melting during postulated accidents. When the metal fuel cladding fails, it typically occurs below the coolant boiling point and the damaged fuel pins remain coolable. Metal fuel is compatible with sodium coolant, eliminating the potential of energetic fuel--coolant reactions and flow blockages. All these, and the low retained heat leading to a longer grace period for operator action, are significant contributing factors to the inherently benign response of metallic fuel to postulated accidents. This paper summarizes the past analytical and experimental results obtained in past sodium-cooled fast reactor safety programs in the United States, and presents an overview of fuel safety performance as observed in laboratory and in-pile tests.« less

  12. Low Emissions Burner Technology for Metal Processing Industry using Byproducts and Biomass Derived Liquid Fuels

    SciTech Connect

    Agrawal, Ajay; Taylor, Robert

    2013-09-30

    path forward to utilize both fossil and alternative liquid fuels in the same combustion system. In particular, experiments show that straight VO can be cleanly combusted without the need for chemical processing or preheating steps, which can result in significant economic and environmental benefits. Next, low-emission combustion of glycerol/methane was achieved by utilizing FB injector to yield fine droplets of highly viscous glycerol. Heat released from methane combustion further improves glycerol pre-vaporization and thus its clean combustion. Methane addition results in an intensified reaction zone with locally high temperatures near the injector exit. Reduction in methane flow rate elongates the reaction zone, which leads to higher CO emissions and lower NOx emissions. Similarly, higher air to liquid (ALR) mass ratio improves atomization and fuel pre-vaporization and shifts the flame closer to the injector exit. In spite of these internal variations, all fuel mixes of glycerol with methane produced similar CO and NOx emissions at the combustor exit. Results show that FB concept provides low emissions with the flexibility to utilize gaseous and highly viscous liquid fuels, straight VO and glycerol, without preheating or preprocessing the fuels. Following these initial experiments in quartz combustor, we demonstrated that glycerol combustion can be stably sustained in a metal combustor. Phase Doppler Particle Analyzer (PDPA) measurements in glycerol/methane flames resulted in flow-weighted Sauter Mean Diameter (SMD) of 35 to 40 μm, depending upon the methane percentage. This study verified that lab-scale dual-fuel burner using FB injector can successfully atomize and combust glycerol and presumably other highly viscous liquid fuels at relatively low HRR (<10 kW). For industrial applications, a scaled-up glycerol burner design thus seemed feasible.

  13. Advanced liquid metal reactor fuel and blanket designs using HT9

    SciTech Connect

    Bridges, A.E.; Waltar, A.E.; Leggett, R.D.; Baker, R.B.; Gneiting, B.C.

    1991-08-01

    This paper discusses the results of the Core Demonstration Experiment being irradiated in the US Department of Energy's Fast Flux Test Facility. The CDE clearly demonstrates that mixed-oxide fuel can achieve burnups in excess of 200 MWd/kgM and fast fluences in excess of 30 {times} 10{sup 22} n/cm{sup 2} using the very low swelling ferritic-martensitic alloy, HT9. Supporting data from post-irradiation examination of the ACO-1 experiment, a related fuel test for the CDE, is reported and compared to the existing austenitic database. Additionally, the current status of a follow-on program to test metal fuel using HT9 is reviewed. 22 refs., 6 figs.

  14. Engineering-Scale Development of Injection Casting Technology for Metal Fuel Cycle

    SciTech Connect

    Ogata, Takanari; Tsukada, Takeshi

    2007-07-01

    Engineering-scale injection casting tests were conducted in order to demonstrate the applicability of injection casting technology to the commercialized fast reactor fuel cycle. The uranium-zirconium alloy slugs produced in the tests were examined with reference to the practical slug specifications: average diameter tolerance {+-} 0.05 mm, local diameter tolerance {+-} 0.1 mm, density range 15.3 to 16.1 g/cm{sup 3}, zirconium content range 10 {+-} 1 wt% and total impurity (C, N, O, Si) <2000 ppm, which were provisionally determined. Most of the slugs satisfied these specifications, except for zirconium content. The impurity level was sufficiently low even though the residual and scrapped alloys were repeatedly recycled. The weight ratio of injected metal to charged metal was sufficiently high for a high process throughput. The injection casting technology will be applicable to the commercialized fuel cycle when the issue of zirconium content variation is resolved. (authors)

  15. Tubular solid oxide fuel cells with porous metal supports and ceramic interconnections

    SciTech Connect

    Huang, Kevin; Ruka, Roswell J

    2012-05-08

    An intermediate temperature solid oxide fuel cell structure capable of operating at from 600.degree. C. to 800.degree. C. having a very thin porous hollow elongated metallic support tube having a thickness from 0.10 mm to 1.0 mm, preferably 0.10 mm to 0.35 mm, a porosity of from 25 vol. % to 50 vol. % and a tensile strength from 700 GPa to 900 GPa, which metallic tube supports a reduced thickness air electrode having a thickness from 0.010 mm to 0.2 mm, a solid oxide electrolyte, a cermet fuel electrode, a ceramic interconnection and an electrically conductive cell to cell contact layer.

  16. Accommodation of unprotected accidents by inherent safety design features in metallic and oxide-fueled LMFBRs

    SciTech Connect

    Su, S.F.; Cahalan, J.E.; Sevy, R.H.

    1985-01-01

    This paper presents the results of a systematic study of the effectiveness of intrinsic design features to mitigate the consequences of unprotected accidents in metallic and oxide-fueled LMFBRs. The accidents analyzed belong to the class generally considered to lead to core disruption; unprotected loss-of-flow (LOF) and transient over-power (TOP). The results of the study demonstrate the potential for design features to meliorate accident consequences, and in some cases to render them benign. Emphasis is placed on the relative performance of metallic and oxide-fueled core designs, and safety margins are quantified in sensitivity studies. All analyses were carried out using the SASSYS LMFBR systems analysis code (1).

  17. Conversion of light hydrocarbon gases to metal carbides for production of liquid fuels and chemicals

    SciTech Connect

    Diaz, A.F.; Modestino, A.J.; Howard, J.B.; Peters, W.A.

    1993-02-01

    Light hydrocarbon gases could be reacted with low cost alkaline earth metal oxide (CaO, MgO) in high-temperature plasma reactor to achieve very high ([le]100%) gas conversion to H[sub 2], CO, and the corresponding metal carbides. These carbides could be stored, transported, and hydrolyzed to acetylene or methyl acetylene, which in turn could be upgraded to a wide range of chemicals and premium liquid hydrocarbon fuels. An electric arc discharge reactor was built for converting methane. Literature reviews were made.

  18. Laboratory studies of shear/leach processing of zircaloy clad metallic uranium reactor fuel

    SciTech Connect

    Swanson, J.L.; Bray, L.A.; Kjarmo, H.E.; Ryan, J.L.; Matsuzaki, C.L.; Pitman, S.G.; Haberman, J.H.

    1985-12-01

    The safety aspects addressed centered on understanding and explaining the undesirable reactions, ''fires,'' observed in a few instances during earlier processing of such fuel at the Nuclear Fuels Services (NFS) plant at West Valley, New York. Consideration of the dissolver fires that occurred at NFS leads to the conclusion that they resulted from rapid reactions with uranium metal, rather than with zirconium metal or with sensitized weld beads. The fires observed at NFS during hulls handling operations may have involved sensitized weld beads as suggested by earlier investigators, but current results suggest that these fires also could have been caused by reactions involving uranium metal. Very little pyrophoric activity was observed in leeached cladding hulls, indicating a very low probability for safety problems resulting from the U-Zr intermetallic zone in N-Reactor fuel. Consideration of the potential role of hydrides in the fires observed at NFS indicates that they were also not important factors. Consideration was also given to protective atmospheres to be used during shearing to prevent excessive reaction during that operation. A water deluge during shearing will likely provide adequate safety while meshing well with other process considerations. Studies on the dissolution of metallic uranium in nitric acid show an initial slower reaction followed by a faster reaction that proceeds at a sustained rate for a prolonged period of time. At solution concentrations typical of those encountered in practical uranium dissolver conditions, this sustained rate is governed by an equation such as: Dissolution rate = K (surface area) ((HNO3)+2(U))/sup 2.6/. Little difference was found in dissolution rates of as-fabricated and of irradiated fuel. The transuranic element content of leached cladding hulls was found to be approx. 400 nCi/g. This is too high to allow disposal as low-level waste.

  19. Complex Equilibrium Calculations of Nonideal Multiphase Systems (CEC- NMS) and Applications to Liquid Metal Fuel Combustion

    DTIC Science & Technology

    1989-03-15

    of Metals with Molten Salts," Molten Salt. Chemistry, M. Blander ed., J. Wiley and Sons, New York. Brinkley, S. R., Jr . (1947), "Calculation of the...Earl Quandt, Jr . Dr. H. W. Carhart Code 2704 Combustion & Fuels David Taylor Naval Ship Naval Research Laboratory Research and Development Center...University Tempe, AZ 85282 Princeton, NY 08544 Dr. Hugh H. Darsie Dr. W. Lee Advanced Technology Group Research and Technology Department Sundstrand Energy

  20. Gas-bubble growth mechanisms in the analysis of metal fuel swelling

    SciTech Connect

    Gruber, E.E.; Kramer, J.M.

    1986-06-01

    During steady-state irradiation, swelling rates associated with growth of fission-gas bubbles in metallic fast reactor fuels may be expected to remain small. As a consequence, bubble-growth mechanisms are not a major consideration in modeling the steady-state fuel behavior, and it is usually adequate to consider the gas pressure to be in equilibrium with the external pressure and surface tension restraint. On transient time scales, however, various bubble-growth mechanisms become important components of the swelling rate. These mechanisms include growth by diffusion, for bubbles within grains and on grain boundaries; dislocation nucleation at the bubble surface, or ''punchout''; and bubble growth by creep. Analyses of these mechanisms are presented and applied to provide information on the conditions and the relative time scales for which the various processes should dominate fuel swelling. The results are compared to a series of experiments in which the swelling of irradiated metal fuel was determined after annealing at various temperatures and pressures. The diffusive growth of bubbles on grain boundaries is concluded to be dominant in these experiments.

  1. Facile and Gram-scale Synthesis of Metal-free Catalysts: Toward Realistic Applications for Fuel Cells

    PubMed Central

    Kim, Ok-Hee; Cho, Yong-Hun; Chung, Dong Young; Kim, Min Jeong; Yoo, Ji Mun; Park, Ji Eun; Choe, Heeman; Sung, Yung-Eun

    2015-01-01

    Although numerous reports on nonprecious metal catalysts for replacing expensive Pt-based catalysts have been published, few of these studies have demonstrated their practical application in fuel cells. In this work, we report graphitic carbon nitride and carbon nanofiber hybrid materials synthesized by a facile and gram-scale method via liquid-based reactions, without the use of toxic materials or a high pressure-high temperature reactor, for use as fuel cell cathodes. The resulting materials exhibited remarkable methanol tolerance, selectivity, and stability even without a metal dopant. Furthermore, these completely metal-free catalysts exhibited outstanding performance as cathode materials in an actual fuel cell device: a membrane electrode assembly with both acidic and alkaline polymer electrolytes. The fabrication method and remarkable performance of the single cell produced in this study represent progressive steps toward the realistic application of metal-free cathode electrocatalysts in fuel cells. PMID:25728910

  2. Facile and gram-scale synthesis of metal-free catalysts: toward realistic applications for fuel cells.

    PubMed

    Kim, Ok-Hee; Cho, Yong-Hun; Chung, Dong Young; Kim, Min Jeong; Yoo, Ji Mun; Park, Ji Eun; Choe, Heeman; Sung, Yung-Eun

    2015-03-02

    Although numerous reports on nonprecious metal catalysts for replacing expensive Pt-based catalysts have been published, few of these studies have demonstrated their practical application in fuel cells. In this work, we report graphitic carbon nitride and carbon nanofiber hybrid materials synthesized by a facile and gram-scale method via liquid-based reactions, without the use of toxic materials or a high pressure-high temperature reactor, for use as fuel cell cathodes. The resulting materials exhibited remarkable methanol tolerance, selectivity, and stability even without a metal dopant. Furthermore, these completely metal-free catalysts exhibited outstanding performance as cathode materials in an actual fuel cell device: a membrane electrode assembly with both acidic and alkaline polymer electrolytes. The fabrication method and remarkable performance of the single cell produced in this study represent progressive steps toward the realistic application of metal-free cathode electrocatalysts in fuel cells.

  3. Facile and Gram-scale Synthesis of Metal-free Catalysts: Toward Realistic Applications for Fuel Cells

    NASA Astrophysics Data System (ADS)

    Kim, Ok-Hee; Cho, Yong-Hun; Chung, Dong Young; Kim, Min Jeong; Yoo, Ji Mun; Park, Ji Eun; Choe, Heeman; Sung, Yung-Eun

    2015-03-01

    Although numerous reports on nonprecious metal catalysts for replacing expensive Pt-based catalysts have been published, few of these studies have demonstrated their practical application in fuel cells. In this work, we report graphitic carbon nitride and carbon nanofiber hybrid materials synthesized by a facile and gram-scale method via liquid-based reactions, without the use of toxic materials or a high pressure-high temperature reactor, for use as fuel cell cathodes. The resulting materials exhibited remarkable methanol tolerance, selectivity, and stability even without a metal dopant. Furthermore, these completely metal-free catalysts exhibited outstanding performance as cathode materials in an actual fuel cell device: a membrane electrode assembly with both acidic and alkaline polymer electrolytes. The fabrication method and remarkable performance of the single cell produced in this study represent progressive steps toward the realistic application of metal-free cathode electrocatalysts in fuel cells.

  4. Activity targets for nanostructured platinum-group-metal-free catalysts in hydroxide exchange membrane fuel cells.

    PubMed

    Setzler, Brian P; Zhuang, Zhongbin; Wittkopf, Jarrid A; Yan, Yushan

    2016-12-06

    Fuel cells are the zero-emission automotive power source that best preserves the advantages of gasoline automobiles: low upfront cost, long driving range and fast refuelling. To make fuel-cell cars a reality, the US Department of Energy has set a fuel cell system cost target of US$30 kW(-1) in the long-term, which equates to US$2,400 per vehicle, excluding several major powertrain components (in comparison, a basic, but complete, internal combustion engine system costs approximately US$3,000). To date, most research for automotive applications has focused on proton exchange membrane fuel cells (PEMFCs), because these systems have demonstrated the highest power density. Recently, however, an alternative technology, hydroxide exchange membrane fuel cells (HEMFCs), has gained significant attention, because of the possibility to use stable platinum-group-metal-free catalysts, with inherent, long-term cost advantages. In this Perspective, we discuss the cost profile of PEMFCs and the advantages offered by HEMFCs. In particular, we discuss catalyst development needs for HEMFCs and set catalyst activity targets to achieve performance parity with state-of-the-art automotive PEMFCs. Meeting these targets requires careful optimization of nanostructures to pack high surface areas into a small volume, while maintaining high area-specific activity and favourable pore-transport properties.

  5. Activity targets for nanostructured platinum-group-metal-free catalysts in hydroxide exchange membrane fuel cells

    NASA Astrophysics Data System (ADS)

    Setzler, Brian P.; Zhuang, Zhongbin; Wittkopf, Jarrid A.; Yan, Yushan

    2016-12-01

    Fuel cells are the zero-emission automotive power source that best preserves the advantages of gasoline automobiles: low upfront cost, long driving range and fast refuelling. To make fuel-cell cars a reality, the US Department of Energy has set a fuel cell system cost target of US$30 kW-1 in the long-term, which equates to US$2,400 per vehicle, excluding several major powertrain components (in comparison, a basic, but complete, internal combustion engine system costs approximately US$3,000). To date, most research for automotive applications has focused on proton exchange membrane fuel cells (PEMFCs), because these systems have demonstrated the highest power density. Recently, however, an alternative technology, hydroxide exchange membrane fuel cells (HEMFCs), has gained significant attention, because of the possibility to use stable platinum-group-metal-free catalysts, with inherent, long-term cost advantages. In this Perspective, we discuss the cost profile of PEMFCs and the advantages offered by HEMFCs. In particular, we discuss catalyst development needs for HEMFCs and set catalyst activity targets to achieve performance parity with state-of-the-art automotive PEMFCs. Meeting these targets requires careful optimization of nanostructures to pack high surface areas into a small volume, while maintaining high area-specific activity and favourable pore-transport properties.

  6. Test design description Volume 2, Part 1. IFR-1 metal fuel irradiation test (AK-181) element as-built data

    SciTech Connect

    Dodds, N. E.

    1986-06-01

    The IFR-1 Test, designated as the AK-181 Test Assembly, will be the first irradiation test of wire wrapped, sodium-bonded metallic fuel elements in the Fast Flux Test Facility (FFTF). The test is part of the Integral Fast Reactor (IFR) fuels program conducted by Argonne National Laboratory (ANL) in support of the Innovative Reactor Concepts Program sponsored by the US Department of Energy (DOE). One subassembly, containing 169 fuel elements, will be irradiated for 600 full power days to achieve 10 at.% burnup. Three metal fuel alloys (U-10Zr, U-8Pu-10Zr) will be irradiated in D9 cladding tubes. The metal fuel elements have a fuel-smeared density of 75% and each contains five slugs. The enriched zone contains three slugs and is 36-in. long. One 6.5-in. long depleted uranium axial blanket slug (DU-10Zr) was loaded at each end of the enriched zone. the fuel elements were fabricated at ANL-W and delivered to Westinghouse-Hanford for wirewrapping and assembly into the test article. This Test Design Description contains relevant data on compositions, densities, dimensions and weights for the cast fuel slugs and completed fuel elements. The elements conform to the requirements in MG-22, "Users` Guide for the Irradiation of Experiments in the FTR."

  7. Separation and Recovery of Uranium Metal from Spent Light Water Reactor Fuel via Electrolytic Reduction and Electrorefining

    SciTech Connect

    S. D. Herrmann; S. X. Li

    2010-09-01

    A series of bench-scale experiments was performed in a hot cell at Idaho National Laboratory to demonstrate the separation and recovery of uranium metal from spent light water reactor (LWR) oxide fuel. The experiments involved crushing spent LWR fuel to particulate and separating it from its cladding. Oxide fuel particulate was then converted to metal in a series of six electrolytic reduction runs that were performed in succession with a single salt loading of molten LiCl – 1 wt% Li2O at 650 °C. Analysis of salt samples following the series of electrolytic reduction runs identified the diffusion of select fission products from the spent fuel to the molten salt electrolyte. The extents of metal oxide conversion in the post-test fuel were also quantified, including a nominal 99.7% conversion of uranium oxide to metal. Uranium metal was then separated from the reduced LWR fuel in a series of six electrorefining runs that were performed in succession with a single salt loading of molten LiCl-KCl-UCl3 at 500 °C. Analysis of salt samples following the series of electrorefining runs identified additional partitioning of fission products into the molten salt electrolyte. Analyses of the separated uranium metal were performed, and its decontamination factors were determined.

  8. Processing of mixed uranium/refractory metal carbide fuels for high temperature space nuclear reactors

    NASA Astrophysics Data System (ADS)

    Knight, Travis; Anghaie, Samim

    2000-01-01

    Single phase, solid-solution mixed uranium/refractory metal carbides have been proposed as an advanced nuclear fuel for high performance, next generation space power and propulsion systems. These mixed carbides such as the pseudo-ternary, (U, Zr, Nb)C, hold significant promise because of their high melting points (typically greater than 3200 K), thermochemical stability in a hot hydrogen environment, and high thermal conductivity. However, insufficient test data exist under nuclear thermal propulsion conditions of temperature and hot hydrogen environment to fully evaluate their performance. Various compositions of (U, Zr, Nb)C were processed with 5% and 10% metal mole fraction of uranium. Stoichiometric samples were processed from the constituent carbide powders while hypostoichiometric samples with carbon-to-metal (C/M) ratios of 0.95 were processed from uranium hydride, graphite, and constituent refractory carbide powders. Processing techniques of cold pressing, sintering, and hot pressing were investigated to optimize the processing parameters necessary to produce dense (low porosity), homogeneous, single phase, solid-solution mixed carbide nuclear fuels for testing. This investigation was undertaken to evaluate and characterize the performance of these mixed uranium/refractory metal carbides for space power and propulsion applications. .

  9. The Potential of Aluminium Metal Powder as a Fuel for Space Propulsion Systems

    NASA Astrophysics Data System (ADS)

    Ismail, A. M.; Osborne, B.; Welch, C. S.

    Metal powder propulsion systems have been addressed intermittently since the Second World War, initially in the field of underwater propulsion where research in the application of propelling torpedoes continues until this day. During the post war era, researchers attempted to utilise metal powders as a fuel for ram jet applications in missiles. The 1960's and 1970's saw additional interest in the use of `pure powder' propellants, i.e. fluidised metal fuel and oxidiser, both in solid particulate form. Again the application was for employment in space-constrained missiles where the idea was to maximise the performance of high energy density powder propellants in order to enhance the missile's flight duration. Metal powder as possible fuel was investigated for in-situ resource utilisation propulsion systems post-1980's where the emphasis was on the use of gaseous oxygen or liquid oxygen combined with aluminium metal powder for use as a ``lunar soil propellant'' or carbon dioxide and magnesium metal powder as a ``Martian propellant''.Albeit aluminium metal powder propellants are lower in performance than cryogenic and Earth storable propellants, the former does have an advantage inasmuch that the propulsion system is generic, i.e. it can be powered with chemicals mined and processed on Earth, the Moon and Mars. Thus, due to the potential refuelling capability, the lower performing aluminium metal powder propellant would effectively possess a much higher change in velocity (V) for multiple missions than the cryogenic or Earth storable propellant which is only suitable for one planet or one mission scenario, respectively.One of the principal limitations of long duration human spaceflight beyond cis-lunar orbit is the lack of refuelling capabilities on distant planets resulting in the reliance on con- ventional non-cryogenic, propellants produced on Earth. If one could develop a reliable propulsion system operating on pro- pellants derived entirely of ingredients found on

  10. Final Scientific Report : Development of Transition Metal/ Chalcogen Based Cathode Catalysts for PEM Fuel Cells

    SciTech Connect

    Campbell, Stephen, A.

    2008-02-29

    The aim of this project was to investigate the potential for using base metal sulfides and selenides as low cost replacements for precious metal catalysts, such as platinum, currently being used in PEM fuel cells. The approach was to deposit thin films of the materials to be evaluated onto inert electrodes and evaluate their activity for the cathode reaction (oxygen reduction) as well as ex-situ structural and compositional characterization. The most active materials identified are CoS2 and the 50:50 solid solution (Co,Ni)S2. However, the OCP of these materials is still considered too low, at 0.83V and 0.89V vs. RHE respectively, for testing in fuel cells. The methods employed here were necessary to compare with the activity of platinum as, when nano-dispersed on carbon supports, the active surface area of these materials is difficult to measure, making comparisons inaccurate. This research adds to the knowledge of potential candidates for platinum replacement in order to reduce the cost of PEM fuel cell technology and promote commercialization. Although the fabrication methods employed here are strictly experimental, methods were also developed to produce nano-dispersed catalysts with similar compositions, structure and activity. Cycling of these catalysts to highly oxidizing potentials resulted in an increase of the open circuit voltage to approach that of platinum, however, it proved difficult to determine why using these dispersed materials. The potential for non-precious, non-metallic, low cost, compound catalysts for PEM fuel cells has been investigated and demonstrated.

  11. Influence of heavy metals on the microbial degradation of diesel fuel.

    PubMed

    Riis, Volker; Babel, Wolfgang; Pucci, Oscar Héctor

    2002-11-01

    The degradation of diesel fuel by a microbial community from a soil polluted by heavy metals (h.m.) in the presence of Cu, Ni, Zn, Pb, Cd, Hg and Cr (as chromate) was investigated. Experiments were conducted with soil slurries and the extracted community in liquid cultivation. The concentrations applied were in the sub-mM and mM range. Whereas the slurries displayed no significant effect, degradation in liquid culture was increasingly inhibited by higher metal concentrations. The course of degradation in suspension was demonstrated by the oxygen consumption. The order of toxicity was found to be: Hg > Cr(VI) > Cu > Cd > Ni > Pb > Zn. The absence of any effect for slurries was due to the non-availability of the metals in the soil, and to precipitation or adsorption to the soil in the case of amendment. The paper also includes results on the availability of h.m. and changes to the community after exposure.

  12. Solid oxide fuel cell systems for residential micro-combined heat and power in the UK: Key economic drivers

    NASA Astrophysics Data System (ADS)

    Hawkes, Adam; Leach, Matthew

    The ability of combined heat and power (CHP) to meet residential heat and power demands efficiently offers potentially significant financial and environmental advantages over centralised power generation and heat-provision through natural-gas fired boilers. A solid oxide fuel cell (SOFC) can operate at high overall efficiencies (heat and power) of 80-90%, offering an improvement over centralised generation, which is often unable to utilise waste heat. This paper applies an equivalent annual cost (EAC) minimisation model to a residential solid oxide fuel cell CHP system to determine what the driving factors are behind investment in this technology. We explore the performance of a hypothetical SOFC system—representing expectations of near to medium term technology development—under present UK market conditions. We find that households with small to average energy demands do not benefit from installation of a SOFC micro-CHP system, but larger energy demands do benefit under these conditions. However, this result is sensitive to a number of factors including stack capital cost, energy import and export prices, and plant lifetime. The results for small and average dwellings are shown to reverse under an observed change in energy import prices, an increase in electricity export price, a decrease in stack capital costs, or an improvement in stack lifetime.

  13. Performance evaluation and characterization of metallic bipolar plates in a proton exchange membrane (PEM) fuel cell

    NASA Astrophysics Data System (ADS)

    Hung, Yue

    Bipolar plate and membrane electrode assembly (MEA) are the two most repeated components of a proton exchange membrane (PEM) fuel cell stack. Bipolar plates comprise more than 60% of the weight and account for 30% of the total cost of a fuel cell stack. The bipolar plates perform as current conductors between cells, provide conduits for reactant gases, facilitate water and thermal management through the cell, and constitute the backbone of a power stack. In addition, bipolar plates must have excellent corrosion resistance to withstand the highly corrosive environment inside the fuel cell, and they must maintain low interfacial contact resistance throughout the operation to achieve optimum power density output. Currently, commercial bipolar plates are made of graphite composites because of their relatively low interfacial contact resistance (ICR) and high corrosion resistance. However, graphite composite's manufacturability, permeability, and durability for shock and vibration are unfavorable in comparison to metals. Therefore, metals have been considered as a replacement material for graphite composite bipolar plates. Since bipolar plates must possess the combined advantages of both metals and graphite composites in the fuel cell technology, various methods and techniques are being developed to combat metallic corrosion and eliminate the passive layer formed on the metal surface that causes unacceptable power reduction and possible fouling of the catalyst and the electrolyte. The main objective of this study was to explore the possibility of producing efficient, cost-effective and durable metallic bipolar plates that were capable of functioning in the highly corrosive fuel cell environment. Bulk materials such as Poco graphite, graphite composite, SS310, SS316, incoloy 800, titanium carbide and zirconium carbide were investigated as potential bipolar plate materials. In this work, different alloys and compositions of chromium carbide coatings on aluminum and SS316

  14. Fuel pin

    DOEpatents

    Christiansen, David W.; Karnesky, Richard A.; Leggett, Robert D.; Baker, Ronald B.

    1989-10-03

    A fuel pin for a liquid metal nuclear reactor is provided. The fuel pin includes a generally cylindrical cladding member with metallic fuel material disposed therein. At least a portion of the fuel material extends radially outwardly to the inner diameter of the cladding member to promote efficient transfer of heat to the reactor coolant system. The fuel material defines at least one void space therein to facilitate swelling of the fuel material during fission.

  15. Fuel pin

    DOEpatents

    Christiansen, David W.; Karnesky, Richard A.; Leggett, Robert D.; Baker, Ronald B.

    1989-01-01

    A fuel pin for a liquid metal nuclear reactor is provided. The fuel pin includes a generally cylindrical cladding member with metallic fuel material disposed therein. At least a portion of the fuel material extends radially outwardly to the inner diameter of the cladding member to promote efficient transfer of heat to the reactor coolant system. The fuel material defines at least one void space therein to facilitate swelling of the fuel material during fission.

  16. Fuel pin

    DOEpatents

    Christiansen, D.W.; Karnesky, R.A.; Leggett, R.D.; Baker, R.B.

    1987-11-24

    A fuel pin for a liquid metal nuclear reactor is provided. The fuel pin includes a generally cylindrical cladding member with metallic fuel material disposed therein. At least a portion of the fuel material extends radially outwardly to the inner diameter of the cladding member to promote efficient transfer of heat to the reactor coolant system. The fuel material defines at least one void space therein to facilitate swelling of the fuel material during fission.

  17. Fuel pin

    SciTech Connect

    Christiansen, D.W.; Karnesky, R.A.; Leggett, R.D.; Baker, R.B.

    1987-11-24

    A fuel pin for a liquid metal nuclear reactor is provided. The fuel pin includes a generally cylindrical cladding member with metallic fuel material disposed therein. At least a portion of the fuel material extends radially outwardly to the inner diameter of the cladding member to promote efficient transfer of heat to the reactor coolant system. The fuel material defines at least one void space therein to facilitate swelling of the fuel material during fission.

  18. Enhancements to BISON U-Zr Metallic Fuel X447 Example Problem

    SciTech Connect

    Galloway, Jack D.; Matthews, Christopher; Unal, Cetin

    2016-09-30

    As development of a metallic fuel modeling capability in BISON has progressed, the need for an example problem used as a comparison basis was observed. Collaborative work between researchers at Los Alamos National Laboratory (LANL) and Idaho National Laboratory (INL) then proceeded to determine a viable rod to use as the basis and create a BISON input deck utilizing as many metallic fuel models as feasible. The basis chosen was what would be considered a generic rod from subassembly X447, an assembly irradiated in EBR-II towards the end of its operating life, heavily based on reported data for fuel pin DP11. Thus, the approach was adopted to use flow characteristics from subassembly X447 as a basis for the convective heat transfer solution, power history and axial power profiles that are representative of rod DP11 from subassembly X447. The rod simulated is a U-10Zr wt% (U-22.5Zr at%) composition. A 2D-RZ mesh would be used to capture axial thermal hydraulic effects, axial swelling and stress-strain calculations over the full length of the rod. After initial work was invested, a refinement of the various models and input parameters was conducted to ensure consistency between operator-declared conditions, model input requirements and those represented in the example problem. This report serves as a synopsis of the enhancements and refinements to the example problem conducted throughout the 2016 fiscal year.

  19. Evaluation of Metal Halide, Plasma, and LED Lighting Technologies for a Hydrogen Fuel Cell Mobile Light (H 2 LT)

    DOE PAGES

    Miller, L. B.; Donohoe, S. P.; Jones, M. H.; ...

    2015-04-22

    This article reports on the testing and comparison of a prototype hydrogen fuel cell light tower (H2LT) and a conventional diesel-powered metal halide light trailer for use in road maintenance and construction activities. The prototype was originally outfitted with plasma lights and then with light-emitting diode (LED) luminaires. Light output and distribution, lighting energy efficiency (i.e., efficacy), power source thermal efficiency, and fuel costs are compared. The metal halide luminaires have 2.2 and 3.1 times more light output than the plasma and LED luminaires, respectively, but they require more power/lumen to provide that output. The LED luminaires have 1.6 timesmore » better light efficacy than either the metal halide or plasma luminaires. The light uniformity ratios produced by the plasma and LED towers are acceptable. The fuel cell thermal efficiency at the power required to operate the plasma lights is 48%, significantly higher than the diesel generator efficiency of 23% when operating the metal halide lights. Due to the increased efficiency of the fuel cell and the LED lighting, the fuel cost per lumen-hour of the H2LT is 62% of the metal halide diesel light tower assuming a kilogram of hydrogen is twice the cost of a gallon of diesel fuel.« less

  20. Extending FEAST-METAL for analysis of low content minor actinide bearing and zirconium rich metallic fuels for sodium fast reactors

    NASA Astrophysics Data System (ADS)

    Karahan, Aydın

    2011-07-01

    Computational models in FEAST-METAL fuel behaviour code have been upgraded to simulate minor actinide bearing zirconium rich metallic fuels for use in sodium fast reactors. Increasing the zirconium content to 20-40 wt.% causes significant changes in fuel slug microstructure affecting thermal, mechanical, chemical, and fission gas behaviour. Inclusion of zirconium rich phase reduces the fission gas swelling rate significantly in early irradiation. Above the threshold fission gas swelling, formation of micro-cracks, and open pores increase material compliancy enhance diffusivity, leading to rapid fuel gas swelling, interconnected porosity development and release of the fission gases and helium. Production and release of helium was modelled empirically as a function of americium content and fission gas production, consistent with previous Idaho National Laboratory studies. Predicted fuel constituent redistribution is much smaller compared to typical U-Pu-10Zr fuel operated at EBR-II. Material properties such as fuel thermal conductivity, modulus of elasticity, and thermal expansion coefficient have been approximated using the available database. Creep rate and fission gas diffusivity of high zirconium fuel is lowered by an order of magnitude with respect to the reference low zirconium fuel based on limited database and in order to match experimental observations. The new code is benchmarked against the AFC-1F fuel assembly post irradiation examination results. Satisfactory match was obtained for fission gas release and swelling behaviour. Finally, the study considers a comparison of fuel behaviour between high zirconium content minor actinide bearing fuel and typical U-15Pu-6Zr fuel pins with 75% smear density. The new fuel has much higher fissile content, allowing for operating at lower neutron flux level compared to fuel with lower fissile density. This feature allows the designer to reach a much higher burnup before reaching the cladding dose limit. On the other

  1. Method of improving fuel cell performance by removing at least one metal oxide contaminant from a fuel cell electrode

    DOEpatents

    Kim, Yu Seung; Choi, Jong-Ho; Zelenay, Piotr

    2009-08-18

    A method of removing contaminants from a fuel cell catalyst electrode. The method includes providing a getter electrode and a fuel cell catalyst electrode having at least one contaminant to a bath and applying a voltage sufficient to drive the contaminant from the fuel cell catalyst electrode to the getter electrode. Methods of removing contaminants from a membrane electrode assembly of a fuel cell and of improving performance of a fuel cell are also provided.

  2. Older Drivers

    MedlinePlus

    ... Affects Driving Tips for Safe Driving Making Your Vehicle Safe Regulations Affecting Older Drivers When Driving Skills ... Like drivers of any age, they use their vehicles to go shopping, do errands, and visit the ...

  3. Space/time explicit Hestia version 2.0 fossil fuel CO2 emissions for the Los Angeles Basin: comparison to atmospheric monitoring, emission drivers, and policy implications

    NASA Astrophysics Data System (ADS)

    Gurney, K. R.; Liang, J.; Patarasuk, R.; O'Keeffe, D.; Newman, S.; Rao, P.; Hutchins, M.; Huang, J.

    2016-12-01

    The Los Angeles Basin represents one of the largest metropolitan areas in the United States and is home to the Megacity Carbon Project, a multi-institutional effort led by NASA JPL to understand the total carbon budget of the Los Angeles Basin. A key component of that effort is the Hestia bottom-up fossil fuel CO2 emissions data product, which quantifies FFCO2 every hour to the spatial scale of individual buildings and road segments. This data product has undergone considerable revision in the last year and the version 2.0 data product is now complete covering the 2011-2014 time period. In this presentation, we highlight the advances in the Hestia version 2.0 including the improvements to onroad, building and industrial emissions. We make comparisons to the independently reported GHG reporting program of the EPA and to in-situ atmospheric measurement of CO2 at two monotiring locations in Pasadena and Palos Verdes. We provide an analysis of the socioeconomic drivers of emissions in the building and onroad transportation sectors across the domain highlighting hotspots of emissions and spatially-specific opportunities for reductions.

  4. Cryogenic Gellant and Fuel Formulation for Metallized Gelled Propellants: Hydrocarbons and Hydrogen with Aluminum

    NASA Technical Reports Server (NTRS)

    Wong, Wing; Starkovich, John; Adams, Scott; Palaszewski, Bryan; Davison, William; Burt, William; Thridandam, Hareesh; Hu-Peng, Hsiao; Santy, Myrrl J.

    1994-01-01

    An experimental program to determine the viability of nanoparticulate gellant materials for gelled hydrocarbons and gelled liquid hydrogen was conducted. The gellants included alkoxides (BTMSE and BTMSH) and silica-based materials. Hexane, ethane, propane and hydrogen were gelled with the newly-formulated materials and their rheological properties were determined: shear stress versus shear rate and their attendant viscosities. Metallized hexane with aluminum particles was also rheologically characterized. The propellant and gellant formulations were selected for the very high surface area and relatively-high energy content of the gellants. These new gellants can therefore improve rocket engine specific impulse over that obtained with traditional cryogenic-fuel gellant materials silicon dioxide, frozen methane, or frozen ethane particles. Significant reductions in the total mass of the gellant were enabled in the fuels. In gelled liquid hydrogen, the total mass of gellant was reduced from 10-40 wt percent of frozen hydrocarbon particles to less that 8 wt percent with the alkoxide.

  5. Test Design Description (TDD). Volume 1A. Design description and safety analysis for IFR-1 metal fuels irradiation test in FFTF

    SciTech Connect

    Tsai, H.; Neimark, L. A.; Billone, M. C.; Fryer, R. M.; Koenig, J. F.; Lehto, W. K.; Malloy, D. J.

    1986-01-01

    A steady-state irradiation experiment on metal fuels, designated IFR-1, will be conducted in the FTR. The purpose of the experiment is to support the development of metal fuels for the Integral Fast Reactor (IFR) program. The main objective of the IFR-1 test is to generate integral fuel performance data for full-length metal fuels. The effect of fuel column length on the integral behavior of metal fuels will be evaluated by comparing the results of the IFR-1 test with those of the EBR-II tests conducted under similar power and temperature conditions. This document describes the IFR-1 metal fuel irradiation experiment and provides the test requirements and supporting steady-state, transient and safety analyses as required by the User`s Guide for the Irradiation of Experiments in the FTR [1] for Test Design Description Volume 1A. 40 refs.

  6. Metal foams application to enhance cooling of open cathode polymer electrolyte membrane fuel cells

    NASA Astrophysics Data System (ADS)

    Sajid Hossain, Mohammad; Shabani, Bahman

    2015-11-01

    Conventional channel flow fields of open cathode Polymer Electrolyte Membrane Fuel Cells (PEMFCs) introduce some challenges linked to humidity, temperature, pressure and oxygen concentration gradients along the conventional flow fields that reduce the cell performance. According to previous experimental reports, with conventional air flow fields, hotspot formation due to water accumulation in Gas Diffusion Layer (GDL) is common. Unlike continuous long flow passages in conventional channels, metal foams provide randomly interrupted flow passages. Re-circulation of fluid, due to randomly distributed tortuous ligaments, enhances temperature and humidity uniformity in the fluid. Moreover, the higher electrical conductivity of metal foams compared to non-metal current collectors and their very low mass density compared to solid metal materials are expected to increase the electrical performance of the cell while significantly reducing its weight. This article reviews the existing cooling systems and identifies the important parameters on the basis of reported literature in the air cooling systems of PEMFCs. This is followed by investigating metal foams as a possible option to be used within the structure of such PEMFCs as an option that can potentially address cooling and flow distribution challenges associated with using conventional flow channels, especially in air-cooled PEMFCs.

  7. Metal ferrite oxygen carriers for chemical looping combustion of solid fuels

    DOEpatents

    Siriwardane, Ranjani V.; Fan, Yueying

    2017-01-31

    The disclosure provides a metal ferrite oxygen carrier for the chemical looping combustion of solid carbonaceous fuels, such as coal, coke, coal and biomass char, and the like. The metal ferrite oxygen carrier comprises MFe.sub.xO.sub.y on an inert support, where MFe.sub.xO.sub.y is a chemical composition and M is one of Mg, Ca, Sr, Ba, Co, Mn, and combinations thereof. For example, MFe.sub.xO.sub.y may be one of MgFe.sub.2O.sub.4, CaFe.sub.2O.sub.4, SrFe.sub.2O.sub.4, BaFe.sub.2O.sub.4, CoFe.sub.2O.sub.4, MnFeO.sub.3, and combinations thereof. The MFe.sub.xO.sub.y is supported on an inert support. The inert support disperses the MFe.sub.xO.sub.y oxides to avoid agglomeration and improve performance stability. In an embodiment, the inert support comprises from about 5 wt. % to about 60 wt. % of the metal ferrite oxygen carrier and the MFe.sub.xO.sub.y comprises at least 30 wt. % of the metal ferrite oxygen carrier. The metal ferrite oxygen carriers disclosed display improved reduction rates over Fe.sub.2O.sub.3, and improved oxidation rates over CuO.

  8. Development of Low-Cost, Clad Metal Bipolar Plates for PEM Fuel Cells

    SciTech Connect

    Weil, K Scott; Yang, Zhenguo; Xia, Guanguang; Kim, Jin Yong; Hardy, Michael; Chang, Steve

    2006-05-18

    The bipolar plate is the most bulky component in the PEMFC stack (in both weight and volume) and one of the most expensive to manufacture. It serves not only as the electrical junction between serially connected cells, but also performs several other key functions in the device: • Distribute the fuel and oxidant uniformly over the active areas of the cells. • Facilitate water management of the membrane to keep it humidified, yet mitigate flooding. • Act as an impermeable barrier between the fuel and oxidant streams (particularly H2) to maintain the hydrogen gradient across the membrane necessary for high power output. • Provide some measure of structural support for the stack. • Remove heat from the active areas of the cells. The use of metal-based bipolar plates in PEMFC stacks potentially offers a number advantages particularly for transportation applications including: low-cost, mass-production via stamping or embossing of sheet product; fabrication in very thin form (< 200μm) to reduce weight and volume in the overall stack; impermeability to fuel, oxidant and water vapor; and in general, excellent thermal conduction properties and good mechanical robustness, even as a thin stamped foil. The primary challenge with metal interconnects is surface corrosion, and the current drive to increase the operating temperature of the stack will only exacerbate this problem. Corrosion of the bipolar plate leads to a release of metal ions that can contaminate the electrolyte membrane and poison the electrode catalysts. In addition, the formation of a passivating oxide or oxyhydroxide layer on the surface of the metal will increase the contact resistance between the bipolar plate and the adjacent graphite electrode backing layer by many orders of magnitude. Both conditions can significantly degrade stack performance. A number of researchers have investigated various schemes for protecting metallic bipolar plates, most of which rely on a thin, inert yet electrically

  9. Outlooks of HLW Partitioning Technologies Usage for Recovering of Platinum Metals from Spent Fuel

    SciTech Connect

    Pokhitonov, Y. A.; Estimantovskiy, V.; Romanovski, v.; Zatsev, B.; Todd, T.

    2003-02-24

    The existing practice of management of high level waste (HLW) generated by NPPs, call for a task of selective separation of the most dangerous long-lived radionuclides with the purpose of their subsequent immobilization and disposal. HLW partitioning allows to reduce substantially the cost of vitrified product storage owing to isolation of the most dangerous radionuclides, such as transplutonium elements (TPE) into separate fractions of small volumes, intended for ultimate storage. By now numerous investigations on partitioning of HLW of various composition have been carried out in many countries and a lot of processes permitting to recover cesium, strontium, TPE and rare earth elements (REE) have been already tested. Apart from enumerated radionuclides, a fair quantity of palladium and rhodium presents in spent fuel, but the problem of these elements recovery has not yet been decided at the operating radiochemical plants. A negative effect of platinum group metals (PGM) occurrence is determined by the formation of separate metal phase, which not only worsens the conditions of glass-melting but also shortens considerably the service life of the equipment. At the same time, the exhaustion of PGMs natural resources may finally lead to such a growth of their costs that the spent nuclear fuel would became a substituting source of these elements industrial production. Allowing above mentioned, it is of interest to develop the technique for ''reactor'' palladium and rhodium recovery process which would be compatible with HLW partitioning and could be realized using the same facilities. In the report the data on platinum metals distribution in spent fuel reprocessing products and the several flowsheets for palladium separation from HLW are presented.

  10. Mixed oxide fuel development

    SciTech Connect

    Leggett, R.D.; Omberg, R.P.

    1987-05-08

    This paper describes the success of the ongoing mixed-oxide fuel development program in the United States aimed at qualifying an economical fuel system for liquid metal cooled reactors. This development has been the cornerstone of the US program for the past 20 years and has proceeded in a deliberate and highly disciplined fashion with high emphasis on fuel reliability and operational safety as major features of an economical fuel system. The program progresses from feature testing in EBR-II to qualifying full size components in FFTF under fully prototypic conditions to establish a basis for extending allowable lifetimes. The development program started with the one year (300 EFPD) core, which is the FFTF driver fuel, continued with the demonstration of a two year (600 EFPD) core and is presently evaluating a three year (900 EFPD) fuel system. All three of these systems, consistent with other LMR fuel programs around the world, use fuel pellets gas bonded to a cladding tube that is assembled into a bundle and fitted into a wrapper tube or duct for ease of insertion into a core. The materials of construction progressed from austenitic CW 316 SS to lower swelling austenitic D9 to non swelling ferritic/martensitic HT9. 6 figs., 2 tabs.

  11. Metal-Organic Frameworks for Removal of Xe and Kr from Nuclear Fuel Reprocessing Plants

    SciTech Connect

    Liu, Jian; Thallapally, Praveen K.; Strachan, Denis M.

    2012-08-07

    Removal of Xenon (Xe) and Krypton (Kr) from in parts per million (ppm) levels were demonstrated for the first time using two well known metal-organic frameworks (MOFs), HKUST-1 and Ni/DOBDC. Results of an activated carbon were also included for comparison. Ni/DOBDC has higher Xe/Kr selectivities than those of the activated carbon. Moreover, results show that the Ni/DOBDC and HKUST-1 can selectively adsorb Xe and Kr from air even at 1000 ppm concentration. This shows a promising future for MOFs in a radioactive nuclides separation from spent fuel.

  12. Non-precious metal catalysis for proton-exchange membrane fuel cells

    NASA Astrophysics Data System (ADS)

    Leonard, Nathaniel Dean

    Non-precious metal catalysts (NPMC) for proton exchange membrane fuel cells (PEMFC) are explored. Research into NPMCs is motivated by the growing need for cleaner, more efficient energy options. NPMCs are one option to make fuel cells more commercially viable. To this end, the present work studies and simulates the morphology and function of metal-nitrogen-carbon (MNC) oxygen reduction catalysts. A porosity study finds that mesoporosity is critical to high performance of autogenic pressure metal-nitrogen-carbon (APMNC) oxygen reduction catalysts. Various carbon materials are used as precursors to synthesis APMNC catalysts. The catalysts and the associated porous carbon materials are characterized morphologically, chemically, and electrochemically. The results indicated that substrates adsorbing the most nitrogen and iron show the highest activity. Furthermore, a relationship is found between mesoporosity and nitrogen content indicating the importance of transport to active site creation. A correlation is found between surface alkalinity and catalytic activity for APMNC catalysts. The basic site strength and quantity were calculated by two different methods, and it was shown that increased Bronsted- Lowry basicity correlates to more active catalysts. The relationship between alkalinity and catalytic activity could be the result of the impact of alkalinity on the electron density of the metal centers or basic sites could encourage active site formation. It is found that the oxygen reduction reaction (ORR) proceeds both via a direct four-electron pathway to water at high potentials and an indirect peroxide pathway at low potentials on an APMNC catalyst. At higher potential, site availability inhibits peroxide generation causing the direct four-electron reduction pathway to dominate. Oxygen reduction begins to shift to the indirect peroxide pathway due to fast kinetics and higher site availability around 0.6 V vs RHE. The net peroxide generation remains relatively low

  13. Rapid thermal cycling of metal-supported solid oxide fuel cellmembranes

    SciTech Connect

    Matus, Yuriy B.; De Jonghe, Lutgard C.; Jacobson, Craig P.; Visco, Steven J.

    2004-01-02

    Solid oxide fuel cell (SOFC) membranes were developed in which zirconia-based electrolyte thin films were supported by a composite metal/ceramic electrode, and were subjected to rapid thermal cycling between 200 and 800 C. The effects of this cycling on membrane performance were evaluated. The membranes, not yet optimized for performance, showed a peak power density of 350mW/cm2at 900 C in laboratory-sized SOFCs that was not affected by the thermal cycling. This resistance to cycling degradation is attributed to the close matching of thermal expansion coefficient of the cermet support electrode with that of the zirconia electrolyte.

  14. Steady state temperature profiles in two simulated liquid metal reactor fuel assemblies with identical design specifications

    SciTech Connect

    Levin, A.E.; Carbajo, J.J.; Lloyd, D.B.; Montgomery, B.H.; Rose, S.D.; Wantland, J.L.

    1985-01-01

    Temperature data from steady state tests in two parallel, simulated liquid metal reactor fuel assemblies with identical design specifications have been compared to determine the extent to which they agree. In general, good agreement was found in data at low flows and in bundle-center data at higher flows. Discrepancies in the data wre noted near the bundle edges at higher flows. An analysis of bundle thermal boundary conditions showed that the possible eccentric placement of one bundle within the housing could account for these discrepancies.

  15. A unique class of alternative catalysts for fuel cell applications that replace the need for precious metals

    SciTech Connect

    Bailey, P.G.

    1995-12-31

    A method has been found that allows the replacement of precious metals with nonmetallic alternative materials for use as the required catalysts in various fuel cell applications. The amount of the precious metal currently used for the catalyst per fuel cell is substantial, and is a significant fraction of the non-variable cost of the entire fuel cell unit. Through the use of a recently developed trade-secret process, a class of nonmetal materials can be manufactured into a metal-like polymer that behaves electrically in an similar manner as do the precious metals during normal fuel cell operation. Samples of these alternative catalysts have been manufactured using an inexpensive process developed and protected under trade secret agreements. Actual small-scale fuel cell demonstration tests have been successfully conducted that verify the operational capabilities of these low-cost alternative catalysts in place of platinum and rhodium. The cost savings of using these alternative catalysts within large scale fuel cell power units may be large.

  16. Effectiveness of a dopant in U-Zr metallic fuel to prevent lanthanide migration

    SciTech Connect

    Kim, Yeon Soo; Wieneck, T.; O'Hare, E.; Fortner, J.

    2013-07-01

    The advanced fast reactor concepts to achieve ultra-high burnup (about 50%) without requiring refueling by way of using metallic alloy fuel have gained interest. Fission product lanthanide accumulation at high burnup is substantial and its migration to cladding and reaction with cladding is a potential life-limiting phenomenon. As a means to solve this problem, adding an element that forms stable compounds with lanthanides to immobilize them has been proposed. The theoretical assessment shows that indium, thallium, gallium, and antimony are good candidates. Except for Sb, because these elements are low-melting temperature elements, liquid metal embrittlement of cladding is a concern if large sized agglomerates exist contacting the cladding. Alloy characterization of as-fabricated samples was performed to examine the effectiveness of the dopant addition method using optical microscopy and scanning electron microscopy. Although preliminary, the present results showed that indium is a better dopant to immobilize lanthanides.

  17. Modeling the behavior of metallic fast reactor fuels during extended transients

    SciTech Connect

    Kramer, J.M.; Liu, Y.Y.; Billone, M.C.; Tsai, H.C.

    1992-01-01

    Passive safety features in the metal-fueled Integral Fast Reactor (IFR) make it possible to avoid core damage for extended time periods even when automatic scram systems fail to operate or heat removal systems are severely degraded. The time scale for these transients are intermediate between those that have traditionally been analyzed in fast reactor safety assessments and those of normal operation. Consequently, it has been necessary to validate models and computer codes (FPIN2 and LIFE-METAL) for application to this time regime. Results from out-of-reactor Whole Pin Furnace tests are being used for this purpose. Pretest predictions for tests FM-1 through FM-6 have been performed and calculations have been compared with the experimental measurements.

  18. Modeling the behavior of metallic fast reactor fuels during extended transients

    SciTech Connect

    Kramer, J.M.; Liu, Y.Y.; Billone, M.C.; Tsai, H.C.

    1992-11-01

    Passive safety features in the metal-fueled Integral Fast Reactor (IFR) make it possible to avoid core damage for extended time periods even when automatic scram systems fail to operate or heat removal systems are severely degraded. The time scale for these transients are intermediate between those that have traditionally been analyzed in fast reactor safety assessments and those of normal operation. Consequently, it has been necessary to validate models and computer codes (FPIN2 and LIFE-METAL) for application to this time regime. Results from out-of-reactor Whole Pin Furnace tests are being used for this purpose. Pretest predictions for tests FM-1 through FM-6 have been performed and calculations have been compared with the experimental measurements.

  19. Comparative Study of Alternative Fuel Icing Inhibitor Additive Properties & Chemical Analysis of Metal Speciation in Aviation Fuels

    DTIC Science & Technology

    2010-08-01

    Jet fuels are a mixture of diverse hydrocarbon chemical species that serve as a fuel source for jet aircraft engines. Jet fuels also contain...Figure 14. Freeze points of FSII-water mixtures by DSC, ASTM-D1177 35 Figure 15. Viscosity profile for the coolilng cycle of 10-100...disalicylidene-1,2-propanediamine (MDA). Fuel System Icing Inhibitor Additives: Petroleum is composed of a diverse mixture of hydrocarbons such as

  20. Emission of Metals from Pelletized and Uncompressed Biomass Fuels Combustion in Rural Household Stoves in China

    NASA Astrophysics Data System (ADS)

    Zhang, Wei; Tong, Yindong; Wang, Huanhuan; Chen, Long; Ou, Langbo; Wang, Xuejun; Liu, Guohua; Zhu, Yan

    2014-07-01

    Effort of reducing CO2 emissions in developing countries may require an increasing utilization of biomass fuels. Biomass pellets seem well-suited for residential biomass markets. However, there is limited quantitative information on pollutant emissions from biomass pellets burning, especially those measured in real applications. In this study, biomass pellets and raw biomass fuels were burned in a pellet burner and a conventional stove respectively, in rural households, and metal emissions were determined. Results showed that the emission factors (EFs) ranged 3.20-5.57 (Pb), 5.20-7.58 (Cu), 0.11-0.23 (Cd), 12.67-39.00 (As), 0.59-1.31 mg/kg (Ni) for pellets, and 0.73-1.34 (Pb), 0.92-4.48 (Cu), 0.08-0.14 (Cd), 7.29-13.22 (As), 0.28-0.62 (Ni) mg/kg for raw biomass. For unit energy delivered to cooking vessels, the EFs ranged 0.42-0.77 (Pb), 0.79-1.16 (Cu), 0.01-0.03 (Cd), 1.93-5.09 (As), 0.08-0.19 mg/MJ (Ni) for pellets, and 0.30-0.56 (Pb), 0.41-1.86 (Cu), 0.04-0.06 (Cd), 3.25-5.49 (As), 0.12-0.26 (Ni) mg/MJ for raw biomass. This study found that moisture, volatile matter and modified combustion efficiency were the important factors affecting metal emissions. Comparisons of the mass-based and task-based EFs found that biomass pellets produced higher metal emissions than the same amount of raw biomass. However, metal emissions from pellets were not higher in terms of unit energy delivered.

  1. REFORMULATION OF COAL-DERIVED TRANSPORTATION FUELS: SELECTIVE OXIDATION OF CARBON MONOXIDE ON METAL FOAM CATALYSTS

    SciTech Connect

    Paul Chin; George W. Roberts; James J. Spivey

    2003-12-31

    Uses for structured catalytic supports, such as ceramic straight-channel monoliths and ceramic foams, have been established for a long time. One of the most prominent examples is the washcoated ceramic monolith as a three-way catalytic converter for gasoline-powered automobiles. A distinct alternative to the ceramic monolith is the metal foam, with potential use in fuel cell-powered automobiles. The metal foams are characterized by their pores per inch (ppi) and density ({rho}). In previous research, using 5 wt% platinum (Pt) and 0.5 wt% iron (Fe) catalysts, washcoated metal foams, 5.08 cm in length and 2.54 cm in diameter, of both varying and similar ppi and {rho} were tested for their activity (X{sub CO}) and selectivity (S{sub CO}) on a CO preferential oxidation (PROX) reaction in the presence of a H{sub 2}-rich gas stream. The variances in these metal foams' activity and selectivity were much larger than expected. Other structured supports with 5 wt% Pt, 0-1 wt% Fe weight loading were also examined. A theory for this phenomenon states that even though these structured supports have a similar nominal catalyst weight loading, only a certain percentage of the Pt/Fe catalyst is exposed on the surface as an active site for CO adsorption. We will use two techniques, pulse chemisorption and temperature programmed desorption (TPD), to characterize our structured supports. Active metal count, metal dispersion, and other calculations will help clarify the causes for the activity and selectivity variations between the supports. Results on ceramic monoliths show that a higher Fe loading yields a lower dispersion, potentially because of Fe inhibition of the Pt surface for CO adsorption. This theory is used to explain the reason for activity and selectivity differences for varying ppi and {rho} metal foams; less active and selective metal foams have a lower Fe loading, which justifies their higher metal dispersion. Data on the CO desorption temperature and average metal

  2. Do trace metals (chromium, copper, and nickel) influence toxicity of diesel fuel for free-living marine nematodes?

    PubMed

    Hedfi, Amor; Boufahja, Fehmi; Ben Ali, Manel; Aïssa, Patricia; Mahmoudi, Ezzeddine; Beyrem, Hamouda

    2013-06-01

    The objective of this study was to test the hypotheses that (1) free-living marine nematodes respond in a differential way to diesel fuel if it is combined with three trace metals (chromium, copper, and nickel) used as smoke suppressants and that (2) the magnitude of toxicity of diesel fuel differs according to the level of trace metal mixture added. Nematodes from Sidi Salem beach (Tunisia) were subjected separately for 30 days to three doses of diesel fuel and three others of a trace metals mixture. Simultaneously, low-dose diesel was combined with three amounts of a trace metal mixture. Results from univariate and multivariate methods of data evaluation generally support our initial hypothesis that nematode assemblages exhibit various characteristic changes when exposed to different types of disturbances; the low dose of diesel fuel, discernibly non-toxic alone, became toxic when trace metals were added. For all types of treatments, biological disturbance caused severe specific changes in assemblage structure. For diesel fuel-treated microcosms, Marylynnia bellula and Chromaspirinia pontica were the best positive indicative species; their remarkable presence in given ecosystem may predict unsafe seafood. The powerful toxicity of the combination between diesel fuel and trace metals was expressed with only negative bioindicators, namely Trichotheristus mirabilis, Pomponema multipapillatum, Ditlevsenella murmanica, Desmodora longiseta, and Bathylaimus capacosus. Assemblages with high abundances of these species should be an index of healthy seafood. When nematodes were exposed to only trace metals, their response looks special with a distinction of a different list of indicative species; the high presence of seven species (T. mirabilis, P. multipapillatum, Leptonemella aphanothecae, D. murmanica, Viscosia cobbi, Gammanema conicauda, and Viscosia glabra) could indicate a good quality of seafood and that of another species (Oncholaimellus mediterraneus) appeared an

  3. High performance metal-supported solid oxide fuel cells with Gd-doped ceria barrier layers

    NASA Astrophysics Data System (ADS)

    Klemensø, Trine; Nielsen, Jimmi; Blennow, Peter; Persson, Åsa H.; Stegk, Tobias; Christensen, Bjarke Holl; Sønderby, Steffen

    Metal-supported solid oxide fuel cells are believed to have commercial advantages compared to conventional anode (Ni-YSZ) supported cells, with the metal-supported cells having lower material costs, increased tolerance to mechanical and thermal stresses, and lower operational temperatures. The implementation of a metallic support has been challenged by the need to revise the cell fabrication route, as well as electrode microstructures and material choices, to compete with the energy output and stability of full ceramic cells. The metal-supported SOFC design developed at Risø DTU has been improved, and an electrochemical performance beyond the state-of-the-art anode-supported SOFC is demonstrated possible, by introducing a CGO barrier layer in combination with Sr-doped lanthanum cobalt oxide (LSC) cathode. Area specific resistances (ASR) down to 0.27 Ω cm 2, corresponding to a maximum power density of 1.14 W cm -2 at 650 °C and 0.6 V, were obtained on cells with barrier layers fabricated by magnetron sputtering. The performance is dependent on the density of the barrier layer, indicating Sr 2+ diffusion is occurring at the intermediate SOFC temperatures. The optimized design further demonstrate improved durability with steady degradation rates of 0.9% kh -1 in cell voltage for up to 3000 h galvanostatic testing at 650 °C and 0.25 A cm -2.

  4. Enhanced Endosomal Escape by Light-Fueled Liquid-Metal Transformer.

    PubMed

    Lu, Yue; Lin, Yiliang; Chen, Zhaowei; Hu, Quanyin; Liu, Yang; Yu, Shuangjiang; Gao, Wei; Dickey, Michael D; Gu, Zhen

    2017-04-12

    Effective endosomal escape remains as the "holy grail" for endocytosis-based intracellular drug delivery. To date, most of the endosomal escape strategies rely on small molecules, cationic polymers, or pore-forming proteins, which are often limited by the systemic toxicity and lack of specificity. We describe here a light-fueled liquid-metal transformer for effective endosomal escape-facilitated cargo delivery via a chemical-mechanical process. The nanoscale transformer can be prepared by a simple approach of sonicating a low-toxicity liquid-metal. When coated with graphene quantum dots (GQDs), the resulting nanospheres demonstrate the ability to absorb and convert photoenergy to drive the simultaneous phase separation and morphological transformation of the inner liquid-metal core. The morphological transformation from nanospheres to hollow nanorods with a remarkable change of aspect ratio can physically disrupt the endosomal membrane to promote endosomal escape of payloads. This metal-based nanotransformer equipped with GQDs provides a new strategy for facilitating effective endosomal escape to achieve spatiotemporally controlled drug delivery with enhanced efficacy.

  5. Transient modeling of spent nuclear fuel electrorefining with liquid metal electrode

    NASA Astrophysics Data System (ADS)

    Seo, Seungjin; Choi, Sungyeol; Park, Byung Gi

    2017-08-01

    During the molten salt electrorefining of spent nuclear fuel, multiple phases such as oxide, solid metal, liquid metal, and molten salt often co-exist. Computational modeling can be a useful tool for understanding the reaction mechanism across the multiple phases. The new model has been developed and applied to a lab-scale electrorefining with liquid metal anode and solid cathode LiCl-KCl molten salt. The benchmark study predicts anodic dissolution and cathodic deposition of U and Pu with minor disagreements. In particular, the on-set of Pu deposition on the surface of the solid cathode is well estimated, which is important for the quality of U ingot and the safeguards of process. The underestimation of U deposition (∼6%) and the overestimation of Pu dissolution (∼7%) at the end of simulation are explained by unconsidered reaction species such as Np and Am from the liquid Cd anode, which overestimates the dissolution of Pu from the anode compared to the measured data. The sensitivity study also reveals the transition behaviors of electrochemical reactions for U and Pu on the solid cathode are changed by diffusion boundary layer thickness, transfer coefficients, and the difference of electrochemical potentials more sensitively than those of the liquid metal anode. For this specific experiment case, the thinner diffusion boundary layer improves the prediction of cathodic reactions particularly at the end of electrorefining.

  6. Accumulation of fossil fuels and metallic minerals in active and ancient rift lakes

    USGS Publications Warehouse

    Robbins, E.I.

    1983-01-01

    A study of active and ancient rift systems around the world suggests that accumulations of fossil fuels and metallic minerals are related to the interactions of processes that form rift valleys with those that take place in and around rift lakes. The deposition of the precursors of petroleum, gas, oil shale, coal, phosphate, barite, Cu-Pb-Zn sulfides, and uranium begins with erosion of uplifted areas, and the consequent input of abundant nutrients and solute loads into swamps and tectonic lakes. Hot springs and volcanism add other nutrients and solutes. The resulting high biological productivity creates oxidized/reduced interfaces, and anoxic and H2S-rich bottom waters which preserves metal-bearing organic tissues and horizons. In the depositional phases, the fine-grained lake deposits are in contact with coarse-grained beach, delta, river, talus, and alluvial fan deposits. Earthquake-induced turbidites also are common coarse-grained deposits of rift lakes. Postdepositional processes in rifts include high heat flow and a resulting concentration of the organic and metallic components that were dispersed throughout the lakebeds. Postdepositional faulting brings organic- and metal-rich sourcebeds in contact with coarse-grained host and reservoir rocks. A suite of potentially economic deposits is therefore a characteristic of rift valleys. ?? 1983.

  7. Development of novel proton exchange membrane fuel cells using stamped metallic bipolar plates

    NASA Astrophysics Data System (ADS)

    Jung, Shiauh-Ping; Lee, Chun-I.; Chen, Chi-Chang; Chang, Wen-Sheng; Yang, Chang-Chung

    2015-06-01

    This study presents the development of novel proton exchange membrane fuel cells using stamped metallic bipolar plates. To achieve uniformly distributed and low pressure-drop flow fields within fuel cells, a novel bipolar plate with straight channels is designed and verification of a fuel-cell short stack using this bipolar plate is performed. In the experiments, low-temperature and low-humidity operations and high-temperature and high-humidity operations are adopted to evaluate effects of stack temperature and inlet relative humidity on performance at various outlet pressures. Experimental results show that under low-temperature and low-humidity operations, increasing the outlet pressure enhances stack performance and reduces performance differences between various stack temperatures. Under high-temperature and high-humidity operations, stack performance increases with increasing outlet pressures, while the extent of their increase becomes smaller. Compared to low-temperature and low-humidity operations, high-temperature and high-humidity operations have better electrochemical reactions and membrane hydration and, thus, better stack performance. In this study, the operation with a stack temperature of 80 °C and outlet pressure of 4 atm produces the best performance of 1100 mA cm-2 at 0.646 V.

  8. RF Plasma Torch System for Metal Matrix Composite Production in Nuclear Fuel Cladding

    NASA Astrophysics Data System (ADS)

    Holik, Eddie, III

    2007-10-01

    For the first time in 30 years, plans are afoot to build new fission power plants in the US. It is timely to develop technology that could improve the safety and efficiency of new reactors. A program of development for advanced fuel cycles and Generation IV reactors is underway. The path to greater efficiency is to increase the core operating temperature. That places particular challenges to the cladding tubes that contain the fission fuel. A promising material for this purpose is a metal matrix composite (MMC) in which ceramic fibers are bonded within a high-strength steel matrix, much like fiberglass. Current MMC technology lacks the ability to effectively bond traditional high-temperature alloys to ceramic strands. The purpose of this project is to design an rf plasma torch system to use titanium as a buffer between the ceramic fibers and the refractory outer material. The design and methods of using an rf plasma torch to produce a non-equilibrium phase reaction to bond together the MMC will be discussed. The effects of having a long lived fuel cladding in the design of future reactors will also be discussed.

  9. Gas-bubble growth mechanisms in the analysis of metal fuel swelling

    SciTech Connect

    Gruber, E E; Kramer, J M

    1985-10-01

    The FRAS3 code has been applied to analysis of a series of experiments on irradiated uranium fuel. Comparison of the predicted bubble-size distributions to those measured indicate that grain-boundary bubbles are an important component of the fission-gas inventory. In these experiments, bubble growth rates were not a factor because of the long heating times. On transient time scales, however, various bubble-growth mechanisms become important in determining swelling rates. These mechanisms include growth by diffusion, for bubbles within grains and on grain boundaries; dislocation nucleation at the bubble surface, or "punchout"; and bubble growth by creep. Analyses of these mechanisms are presented and applied to provide information on the conditions and the relative time scales for which the various processes should dominate fuel swelling. The results are compared to a series of experiments in which the swelling of irradiated metal fuel was determined after annealing at various temperatures and pressures. The diffusive growth of bubbles on grain boundaries is concluded to be dominant in these experiments.

  10. Characteristics of aqueous colloids generated by corrosion of metallic uranium fuel.

    SciTech Connect

    Fortner, J. A.; Mertz, C. J.; Goldberg, M. M.; Siefert, S.

    2002-09-12

    Metallic uranium fuel from the Hanford N Reactor was corroded in aqueous solutions and the resulting colloidal suspensions were analyzed to determine particle size, morphology, population, and radionuclide association. The experiments used a range of solution chemistry conditions including deionized water, single salt solutions, and modified groundwater from Yucca Mountain. Colloids were analyzed by inductively coupled plasma mass spectrometry, transmission electron microscopy, photon correlation spectroscopy, and synchrotron small-angle x-ray scattering. The results of these analyses indicate that stable suspensions of small (1-10 nm diameter), spherical uranium oxides are generated and aggregate to approximately 100-200 nm colloids. There is no indication that these colloids continue to aggregate to larger size. In silicate solutions, large acicular uranium silicate colloids are formed in small quantities as are large uranium-bearing smectite clay colloids. Plutonium clearly associates with colloidal particles. Large particles contain the same Pu/U ratio as the uncorroded fuel, possibly indicating that the Pu is incorporated in the particle matrix. Smaller particles are highly enriched in Pu relative to the uncorroded fuel.

  11. Dust survey following the final shutdown of TEXTOR: metal particles and fuel retention

    NASA Astrophysics Data System (ADS)

    Fortuna-Zaleśna, E.; Weckmann, A.; Grzonka, J.; Rubel, M.; Esser, H. G.; Freisinger, M.; Kreter, A.; Sergienko, G.; Ström, P.

    2016-02-01

    The work presents results of a broad TEXTOR dust survey in terms of its composition, structure, distribution and fuel content. The dust particles were collected after final shutdown of TEXTOR in December 2013. Fuel retention, as determined by thermal desorption, varied significantly, even by two orders of magnitude, dependent on the dust location in the machine. Dust structure was examined by means of scanning electron microscopy combined with energy-dispersive x-ray spectroscopy, focused ion beam and scanning transmission electron microscopy. Several categories of dust have been identified. Carbon-based stratified and granular deposits were dominating, but the emphasis in studies was on metal dust. They were found in the form of small particles, small spheres, flakes and splashes which formed ‘comet’-like structures, clearly indicating directional effects in the impact on surfaces of plasma-facing components. Nickel-rich alloys from the Inconel liner and iron-based ones from various diagnostic holders were the main components of metal-containing dust, but also molybdenum and tungsten debris were detected. Their origin is discussed.

  12. Impact of Fuel Metal Impurities on the Durability of a Light-Duty Diesel Aftertreatment System

    SciTech Connect

    Williams, A.; Burton, J.; McCormick, R. L.; Toops, T.; Wereszczak, A. A.; Fox, E. E.; Lance, M. J.; Cavataio, G.; Dobson, D.; Warner, J.; Brezny, R.; Nguyen, K.; Brookshear, D. W.

    2013-04-01

    Alkali and alkaline earth metal impurities found in diesel fuels are potential poisons for diesel exhaust catalysts. A set of diesel engine production exhaust systems was aged to 150,000 miles. These exhaust systems included a diesel oxidation catalyst, selective catalytic reduction (SCR) catalyst, and diesel particulate filter (DPF). Four separate exhaust systems were aged, each with a different fuel: ultralow sulfur diesel containing no measureable metals, B20 (a common biodiesel blend) containing sodium, B20 containing potassium, and B20 containing calcium, which were selected to simulate the maximum allowable levels in B100 according to ASTM D6751. Analysis included Federal Test Procedure emissions testing, bench-flow reactor testing of catalyst cores, electron probe microanalysis (EPMA), and measurement of thermo-mechanical properties of the DPFs. EPMA imaging found that the sodium and potassium penetrated into the washcoat, while calcium remained on the surface. Bench-flow reactor experiments were used to measure the standard nitrogen oxide (NOx) conversion, ammonia storage, and ammonia oxidation for each of the aged SCR catalysts. Vehicle emissions tests were conducted with each of the aged catalyst systems using a chassis dynamometer. The vehicle successfully passed the 0.2 gram/mile NOx emission standard with each of the four aged exhaust systems.

  13. Investigation on heavy liquid metal cooling of ADS fuel pin assemblies

    NASA Astrophysics Data System (ADS)

    Litfin, K.; Batta, A.; Class, A. G.; Wetzel, Th.; Stieglitz, R.

    2011-08-01

    In the framework of accelerator driven sub-critical reactor systems heavy liquid metals are considered as coolant for the reactor core and the spallation target. In particular lead or lead bismuth eutectic (LBE) exhibit efficient heat removal properties and high production rate of neutrons. However, the excellent heat conductivity of LBE-flows expressed by a low molecular Prandtl number of the order 10 -2 requires improved modeling of the turbulent heat transfer. Although various models for thermal hydraulics of LBE flows are existing, validated heat transfer correlations for ADS-relevant conditions are still missing. In order to validate the sub-channel codes and computational fluid dynamics codes used to design fuel assemblies, the comparison with experimental data is inevitable. Therefore, an experimental program composed of three major experiments, a single electrically heated rod, a 19-pin hexagonal water rod bundle and a LBE rod bundle, has been initiated at the Karlsruhe Liquid metal Laboratory (KALLA) of the Karlsruhe Institute of Technology, in order to quantify and separate the individual phenomena occurring in the momentum and energy transfer of a fuel assembly.

  14. Preliminary Compatibility Assessment of Metallic Dispenser Materials for Service in Ethanol Fuel Blends

    SciTech Connect

    Pawel, Steven J; Kass, Michael D; Janke, Christopher James

    2009-11-01

    The compatibility of selected metals representative of those commonly used in dispensing systems was evaluated in an aggressive E20 formulation (CE20a) and in synthetic gasoline (Reference Fuel C) in identical testing to facilitate comparison of results. The testing was performed at modestly elevated temperature (nominally 60 C) and with constant fluid flow in an effort to accelerate potential interactions in the screening test. Based on weight change, the general corrosion of all individual coupons exposed in the vapor phase above Reference Fuel C and CE20a as well as all coupons immersed in Reference Fuel C was essentially nil (<0.3 {micro}m/y), with no evidence of localized corrosion such as pitting/crevice corrosion or selective leaching at any location. Modest discoloration was observed on the copper-based alloys (cartridge brass and phosphor bronze), but the associated corrosion films were quite thin and apparently protective. For coupons immersed in CE20a, four different materials exhibited net weight loss over the entire course of the experiment: cartridge brass, phosphor bronze, galvanized steel, and terne-plated steel. None of these exhibited substantial incompatibility with the test fluid, with the largest general corrosion rate calculated from coupon weight loss to be approximately 4 {micro}m/y for the cartridge brass specimens. Selective leaching of zinc (from brass) and tin (from bronze) was observed, as well as the presence of sulfide surface films rich in these elements, suggesting the importance of the role of sulfuric acid in the CE20a formulation. Analysis of weight loss data for the slightly corroded metals indicated that the corrosivity of the test environment decreased with exposure time for brass and bronze and increased for galvanized and terne-plated steel. Other materials immersed in CE20a - type 1020 mild steel, type 1100 aluminum, type 201 nickel, and type 304 stainless steel - each appeared essentially immune to corrosion at the test

  15. Metal-Organic-Framework-Derived Dual Metal- and Nitrogen-Doped Carbon as Efficient and Robust Oxygen Reduction Reaction Catalysts for Microbial Fuel Cells.

    PubMed

    Tang, Haolin; Cai, Shichang; Xie, Shilei; Wang, Zhengbang; Tong, Yexiang; Pan, Mu; Lu, Xihong

    2016-02-01

    A new class of dual metal and N doped carbon catalysts with well-defined porous structure derived from metal-organic frameworks (MOFs) has been developed as a high-performance electrocatalyst for oxygen reduction reaction (ORR). Furthermore, the microbial fuel cell (MFC) device based on the as-prepared Ni/Co and N codoped carbon as air cathode catalyst achieves a maximum power density of 4335.6 mW m(-2) and excellent durability.

  16. Mesoporous zeolite-supported noble metal catalysts for low-temperature hydrogenation of aromatics in distillate fuels

    SciTech Connect

    Reddy, K.M.; Song, C.

    1996-12-31

    The present work is concerned with deep hydrogenation of aromatics in distillate fuels at low temperatures using mesoporous zeolite-supported noble metal catalysts. This work is a part of our on-going effort to develop advanced thermally stable jet fuels from coal-derived liquids and petroleum. Saturation of naphthalene and its derivatives from only reduces aromatics contents of jet fuels, but also generates decalins which show much higher thermal stability than long-chain alkanes in jet fuels at high temperature. This work also has a bearing on developing new catalytic processes for low-temperature hydrogenation of distillate fuels. The Clean Air Act Amendments of 1990 and new regulations call for the production and use of more environmentally friendly transportation fuels with lower contents of sulfur and aromatics. High aromatic content in distillate fuels lowers the fuel quality and contributes significantly to the formation of environmentally harmful emissions. California Air Resources Board (CARB) has passed legislative measures to limit the sulfur and aromatic contents of diesel fuel to 0.05 wt% and 10 vol%, respectively, effective October 1993. Currently, conventional hydrotreating technology is adapted for aromatics saturation. Some studies have shown that complete hydrogenation of aromatics is not possible owing to equilibrium limitations under typical hydrotreating conditions, and existing middle distillate hydrotreaters designed to reduce sulfur and nitrogen levels would lower the diesel aromatics only marginally.

  17. Evaluation of an EMITEC resistively heated metal monolith catalytic converter on two M100 neat methanol-fueled vehicles

    NASA Astrophysics Data System (ADS)

    Piotrowski, Gregory K.; Schaefer, Ronald M.

    1992-12-01

    The report describes the evaluation of a resistively heated catalyst system on two different methanol fueled vehicles. The EMITEC catalyst consisted of a compact resistively heated metal monolith in front of a larger conventional main converter. The EMITEC catalyst was evaluated on two neat methanol-fueled vehicles, a 1981 Volkswagen Rabbit and a 1988 Toyota Corolla. Emission testing was conducted over the Federal Test Procedure (FTP) CVS-75 test cycle. The emissions of primary interest were cold start methanol (unburned fuel), carbon monoxide, and formaldehyde.

  18. The Hanford spent nuclear metal fuel multi-canister overpack and vacuum drying {ampersand} hot conditioning process

    SciTech Connect

    Irwin, J.J.

    1996-05-15

    Nuclear production reactors operated at the U.S. Department of Energy`s Hanford Site from 1944 until 1988 to produce plutonium. Most of the irradiated fuel from these reactors was processed onsite to separate and recover the plutonium. When the processing facilities were closed in 1992, about 1,900 metric tons of unprocessed irradiated fuel remained in storage. Additional fuel was irradiated for research purposes or was shipped to the Hanford Site from offsite reactor facilities for storage or recovery of nuclear materials. The fuel inventory now in storage at the Hanford Site is predominantly N Reactor irradiated fuel, a metallic uranium alloy that is coextruded into zircaloy-2 cladding. The Spent Nuclear Fuel Project has rommitted to an accelerated schedule for removing spent nuclear fuel from the Hanford Site K Basins to a new interim storage facility in the 200 Area. Under the current proposed accelerated schedule, retrieval of spent nuclear fuel stored in the K East and West Basins must begin by December 1997 and be completed by December 1999. A key part of this action is retrieving fuel canisters from the water-filled K Basin storage pools and transferring them into multi@ister overpacks (MCOS) that will be used to handle and process the fuel, then store it after conditioning. The Westinghouse Hanford Company has developed an integrated process to deal with the K Basin spent fuel inventory. The process consists of cleaning the fuel, packaging it into MCOS, vacuum drying it at the K Basins, then transporting it to the Canister Storage Building (CSB) for staging, hot conditioning, and interim storage. This presentation dekribes the MCO function, design, and life-cycle, including an overview of the vacuum drying and hot conditioning processes.

  19. Microbial fuel cell driving electrokinetic remediation of toxic metal contaminated soils.

    PubMed

    Habibul, Nuzahat; Hu, Yi; Sheng, Guo-Ping

    2016-11-15

    An investigation of the feasibility of in-situ electrokinetic remediation for toxic metal contaminated soil driven by microbial fuel cell (MFC) is presented. Results revealed that the weak electricity generated from MFC could power the electrokinetic remediation effectively. The metal removal efficiency and its influence on soil physiological properties were also investigated. With the electricity generated through the oxidation of organics in soils by microorganisms, the metals in the soils would mitigate from the anode to the cathode. The concentrations of Cd and Pb in the soils increased gradually through the anode to the cathode regions after remediation. After about 143days and 108 days' operation, the removal efficiencies of 31.0% and 44.1% for Cd and Pb at the anode region could be achieved, respectively. Soil properties such as pH and soil conductivity were also significantly redistributed from the anode to the cathode regions. The study shows that the MFC driving electrokinetic remediation technology is cost-effective and environmental friendly, with a promising application in soil remediation.

  20. Effect of delivery condition on desorption rate of ZrCo metal hydride bed for fusion fuel cycle

    SciTech Connect

    Kang, H.G.; Yun, S.H.; Chung, D.; Oh, Y.H.; Chang, M.H.; Cho, S.; Chung, H.; Song, K.M.

    2015-03-15

    For the safety of fusion fuel cycle, hydrogen isotope gases including tritium are stored as metal hydride form. To satisfy fueling requirement of fusion machine, rapid delivery from metal hydride bed is one of major factors for the development of tritium storage and delivery system. Desorption from metal hydride depends on the operation scenario by pressure and temperature control of the bed. The effect of operation scenario and pump performance on desorption rate of metal hydride bed was experimentally investigated using ZrCo bed. The results showed that the condition of pre-heating scenario before actual delivery of gas affected the delivery performance. Different pumps were connected to desorption line from bed and the effect of pump capacity on desorption rate were also found to be significant. (authors)

  1. Novel architectured metal-supported solid oxide fuel cells with Mo-doped SrFeO3-δ electrocatalysts

    NASA Astrophysics Data System (ADS)

    Zhou, Yucun; Meng, Xie; Liu, Xuejiao; Pan, Xin; Li, Junliang; Ye, Xiaofeng; Nie, Huaiwen; Xia, Changrong; Wang, Shaorong; Zhan, Zhongliang

    2014-12-01

    Barriers to technological advancement of metal-supported SOFCs include nickel coarsening in the anode, metallic interdiffusion between the anode and the metal substrate, as well as poor cathode adhesion. Here we report a robust and novel architectured metal-supported SOFC that consists of a thin dense yttria-stabilized zirconia (YSZ) electrolyte layer sandwiched between a porous 430L stainless steel substrate and a porous YSZ thin layer. The key feature is simultaneous use of impregnated nano-scale SrFe0.75Mo0.25O3-δ coatings on the internal surfaces of the porous 430L and YSZ backbones respectively as the anode and cathode catalyst. Such a fuel cell exhibits power densities of 0.74 W cm-2 at 800 °C and 0.40 W cm-2 at 700 °C when operating on hydrogen fuels and air oxidants.

  2. Interaction of coal-derived synthesis gas impurities with solid oxide fuel cell metallic components

    NASA Astrophysics Data System (ADS)

    Marina, Olga A.; Pederson, Larry R.; Coyle, Christopher A.; Edwards, Danny J.; Chou, Yeong-Shyung; Cramer, Carolyn N.

    Oxidation-resistant alloys find use as interconnect materials, heat exchangers, and gas supply tubing in solid oxide fuel cell (SOFC) systems, especially when operated at temperatures below ∼800 °C. If fueled with synthesis gas derived from coal or biomass, such metallic components could be exposed to impurities contained in those fuel sources. In this study, coupons of ferritic stainless steels Crofer 22 APU and SS 441, austenitic nickel-chromium superalloy Inconel 600, and an alumina-forming high nickel alloy alumel were exposed to synthesis gas containing ≤2 ppm phosphorus, arsenic and antimony, and reaction products were tested. Crofer 22 APU coupons coated with a (Mn,Co) 3O 4 protective layer were also evaluated. Phosphorus was found to be the most reactive. On Crofer 22 APU, the (Mn,Cr) 3O 4 passivation layer reacted to form an Mn-P-O product, predicted to be manganese phosphate from thermochemical calculations, and Cr 2O 3. On SS 441, reaction of phosphorus with (Mn,Cr) 3O 4 led to the formation of manganese phosphate as well as an Fe-P product, predicted from thermochemical calculations to be Fe 3P. Minimal interactions with antimony or arsenic in synthesis gas were limited to Fe-Sb and Fe-As solid solution formation. Though not intended for use on the anode side, a (Mn,Co) 3O 4 spinel coating on Crofer 22 APU reacted with phosphorus in synthesis gas to produce products consistent with Mn 3(PO 4) 2 and Co 2P. A thin Cr 2O 3 passivation layer on Inconel 600 did not prevent the formation of nickel phosphides and arsenides and of iron phosphides and arsenides, though no reaction with Cr 2O 3 was apparent. On alumel, an Al 2O 3 passivation layer rich in Ni did not prevent the formation of nickel phosphides, arsenides, and antimonides, though no reaction with Al 2O 3 occurred. This work shows that unprotected metallic components of an SOFC stack and system can provide a sink for P, As and Sb impurities that may be present in fuel gases, and thus complicate

  3. Influence of carbonation under oxy-fuel combustion flue gas on the leachability of heavy metals in MSWI fly ash.

    PubMed

    Ni, Peng; Xiong, Zhuo; Tian, Chong; Li, Hailong; Zhao, Yongchun; Zhang, Junying; Zheng, Chuguang

    2017-09-01

    Due to the high cost of pure CO2, carbonation of MSWI fly ash has not been fully developed. It is essential to select a kind of reaction gas with rich CO2 instead of pure CO2. The CO2 uptake and leaching toxicity of heavy metals in three typical types of municipal solid waste incinerator (MSWI) fly ash were investigated with simulated oxy-fuel combustion flue gas under different reaction temperatures, which was compared with both pure CO2 and simulated air combustion flue gas. The CO2 uptake under simulated oxy-fuel combustion flue gas were similar to that of pure CO2. The leaching concentration of heavy metals in all MSWI fly ash samples, especially in ash from Changzhou, China (CZ), decreased after carbonation. Specifically, the leached Pb concentration of the CZ MSWI fly ash decreased 92% under oxy-fuel combustion flue gas, 95% under pure CO2 atmosphere and 84% under the air combustion flue gas. After carbonation, the leaching concentration of Pb was below the Chinese legal limit. The leaching concentration of Zn from CZ sample decreased 69% under oxy-fuel combustion flue gas, which of Cu, As, Cr and Hg decreased 25%, 33%, 11% and 21%, respectively. In the other two samples of Xuzhou, China (XZ) and Wuhan, China (WH), the leaching characteristics of heavy metals were similar to the CZ sample. The speciation of heavy metals was largely changed from the exchangeable to carbonated fraction because of the carbonation reaction under simulated oxy-fuel combustion flue gas. After carbonation reaction, most of heavy metals bound in carbonates became more stable and leached less. Therefore, oxy-fuel combustion flue gas could be a low-cost source for carbonation of MSWI fly ash. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Analysis of additive metals in fuel and emission aerosols of diesel vehicles with and without particle traps.

    PubMed

    Ulrich, Andrea; Wichser, Adrian

    2003-09-01

    Fuel additives used in particle traps have to comply with environmental directives and should not support the formation of additional toxic substances. The emission of metal additives from diesel engines with downstream particle traps has been studied. Aspects of the optimisation of sampling procedure, sample preparation and analysis are described. Exemplary results in form of a mass balance calculation are presented. The results demonstrate the high retention rate of the studied filter system but also possible deposition of additive metals in the engine.

  5. Irradiation performance of Fast Flux Test Facility drivers using D9 alloy

    SciTech Connect

    Pitner, A.L.; Gneiting, B.C.; Bard, F.E.

    1995-11-01

    In comparison with the Fast Flux Test Facility Type 316 stainless steel driver design, six test assemblies employing D9 alloy in place of stainless steel for duct, cladding, and wire wrap material were irradiated to demonstrate the improved performance and lifetime capability of an advanced D9 alloy driver design. A single pinhole-type breach occurred in one of the high-exposure tests after a peak fuel burnup of 155 MWd/kg metal (M) and peak fast neutron fluence of 25 {times} 10{sup 22} n/cm{sup 2} (E > 0.1 MeV). Postirradiation examinations were performed on four of the test assemblies and measured results were compared with analytical evaluations. A revised swelling correlation for D9 alloy was developed to provide improved agreement between calculated and measured cladding deformation results. A fuel pin lifetime design criterion of 5% calculated hoop strain was derived from these results. Alternatively, fuel pin lifetimes were developed for two irradiation parameters using statistical failure analyses. For a 99.99% reliability, the analyses indicated a peak fast-fluence lifetime of 21.0 {times} 10{sup 22} n/cm{sup 2}, or a peak fuel burnup >120 MWd/kg M. In comparison with the Fast Flux Test Facility reference driver design, the extended lifetime capability of D9 alloy would reduce fuel supply requirements for the liquid-metal reactor by a third.

  6. Designated drivers: the differing roles of divalent metal ions in surfactant adsorption at the oil-water interface.

    PubMed

    Robertson, Ellen J; Beaman, Daniel K; Richmond, Geraldine L

    2013-12-17

    Divalent metal ions play numerous roles in biological, technological, and environmental systems. This study examines the role of a variety of ions, Mg(2+), Ca(2+), Mn(2+), Ni(2+), Cu(2+), and Zn(2+), in the adsorption of sodium decanoate at the carbon tetrachloride-water interface. For all ions studied, the ions drive the adsorption of the surfactant to the interface. Using vibrational sum-frequency spectroscopy and the carboxylic acid vibrational modes as a signature for metal ion binding, each metal salt is found to play a distinctly different role in the molecular characteristics of surfactant adsorption at the interface. Additional spectroscopic studies of the methyl and methylene vibrations are monitored to track the ordering of the alkyl chains when metal salts are added to solution. How the metal-surfactant binding impacts the surfactant structure, orientation, and solvation is explored. How these spectroscopic measurements compare with the degree of adsorption as measured by interfacial tension data is presented.

  7. Design principles for oxygen-reduction activity on perovskite oxide catalysts for fuel cells and metal-air batteries

    NASA Astrophysics Data System (ADS)

    Suntivich, Jin; Gasteiger, Hubert A.; Yabuuchi, Naoaki; Nakanishi, Haruyuki; Goodenough, John B.; Shao-Horn, Yang

    2011-07-01

    The prohibitive cost and scarcity of the noble-metal catalysts needed for catalysing the oxygen reduction reaction (ORR) in fuel cells and metal-air batteries limit the commercialization of these clean-energy technologies. Identifying a catalyst design principle that links material properties to the catalytic activity can accelerate the search for highly active and abundant transition-metal-oxide catalysts to replace platinum. Here, we demonstrate that the ORR activity for oxide catalysts primarily correlates to σ*-orbital (eg) occupation and the extent of B-site transition-metal-oxygen covalency, which serves as a secondary activity descriptor. Our findings reflect the critical influences of the σ* orbital and metal-oxygen covalency on the competition between O22-/OH- displacement and OH- regeneration on surface transition-metal ions as the rate-limiting steps of the ORR, and thus highlight the importance of electronic structure in controlling oxide catalytic activity.

  8. Design principles for oxygen-reduction activity on perovskite oxide catalysts for fuel cells and metal-air batteries.

    PubMed

    Suntivich, Jin; Gasteiger, Hubert A; Yabuuchi, Naoaki; Nakanishi, Haruyuki; Goodenough, John B; Shao-Horn, Yang

    2011-06-12

    The prohibitive cost and scarcity of the noble-metal catalysts needed for catalysing the oxygen reduction reaction (ORR) in fuel cells and metal-air batteries limit the commercialization of these clean-energy technologies. Identifying a catalyst design principle that links material properties to the catalytic activity can accelerate the search for highly active and abundant transition-metal-oxide catalysts to replace platinum. Here, we demonstrate that the ORR activity for oxide catalysts primarily correlates to σ-orbital (e(g)) occupation and the extent of B-site transition-metal-oxygen covalency, which serves as a secondary activity descriptor. Our findings reflect the critical influences of the σ orbital and metal-oxygen covalency on the competition between O(2)(2-)/OH(-) displacement and OH(-) regeneration on surface transition-metal ions as the rate-limiting steps of the ORR, and thus highlight the importance of electronic structure in controlling oxide catalytic activity.

  9. Ceramic plasma-sprayed coating of melting crucibles for casting metal fuel slugs

    NASA Astrophysics Data System (ADS)

    Kim, Ki Hwan; Lee, Chong Tak; Lee, Chan Bock; Fielding, R. S.; Kennedy, J. R.

    2013-10-01

    Thermal cycling and melt reaction studies of ceramic coatings plasma-sprayed on Nb substrates were carried out to evaluate the performance of barrier coatings for metallic fuel casting applications. Thermal cycling tests of the ceramic plasma-sprayed coatings to 1450 °C showed that HfN, TiC, ZrC, and Y2O3 coating had good cycling characteristics with few interconnected cracks even after 20 cycles. Interaction studies by 1550 °C melt dipping tests of the plasma-sprayed coatings also indicated that HfN and Y2O3 do not form significant reaction layer between U-20 wt.% Zr melt and the coating layer. Plasma-sprayed Y2O3 coating exhibited the most promising characteristics among HfN, TiC, ZrC, and Y2O3 coating.

  10. Ceramic plasma-sprayed coating of melting crucibles for casting metal fuel slugs

    SciTech Connect

    K.H. Kim; C.T. Lee; C.B. Lee; R.S. Fielding; J.R. Kennedy

    2013-10-01

    Thermal cycling and melt reaction studies of ceramic coatings plasma-sprayed on Nb substrates were carried out to evaluate the performance of barrier coatings for metallic fuel casting applications. Thermal cycling tests of the ceramic plasma-sprayed coatings to 1450 degrees C showed that HfN, TiC, ZrC, and Y2O3 coating had good cycling characteristics with few interconnected cracks even after 20 cycles. Interaction studies by 1550 degrees C melt dipping tests of the plasma-sprayed coatings also indicated that HfN and Y2O3 do not form significant reaction layer between U–20 wt.% Zr melt and the coating layer. Plasma-sprayed Y2O3 coating exhibited the most promising characteristics among HfN, TiC, ZrC, and Y2O3 coating.

  11. Comparison of effect of insulating blockages on metal and oxide fuel elements

    SciTech Connect

    Tilbrook, R.W.; Dever, D.J.

    1988-01-01

    The safety philosophy of the new liquid metal reactor (LMR) plant designs is oriented towards inherent protection against loss of coolable geometry and other entries to core disruption. On potential entry is via propagation of local faults. Within this category is a wide range of initiators which each require assessment of their probability and consequences in order to determine their contribution to plant risk. Local faults include those initiators which cause local power/flow disturbances restricted either to a single subassembly or to a local region of the bundle. The concern is that these localized initiators may start a sequence of events in which fuel failure may propagate first within a subassembly envelope and finally cause loss of coolable geometry in adjacent. This document discusses these scenarios. 3 refs., 1 fig.

  12. Emission of Metals from Pelletized and Uncompressed Biomass Fuels Combustion in Rural Household Stoves in China

    PubMed Central

    Zhang, Wei; Tong, Yindong; Wang, Huanhuan; Chen, Long; Ou, Langbo; Wang, Xuejun; Liu, Guohua; Zhu, Yan

    2014-01-01

    Effort of reducing CO2 emissions in developing countries may require an increasing utilization of biomass fuels. Biomass pellets seem well-suited for residential biomass markets. However, there is limited quantitative information on pollutant emissions from biomass pellets burning, especially those measured in real applications. In this study, biomass pellets and raw biomass fuels were burned in a pellet burner and a conventional stove respectively, in rural households, and metal emissions were determined. Results showed that the emission factors (EFs) ranged 3.20–5.57 (Pb), 5.20–7.58 (Cu), 0.11–0.23 (Cd), 12.67–39.00 (As), 0.59–1.31 mg/kg (Ni) for pellets, and 0.73–1.34 (Pb), 0.92–4.48 (Cu), 0.08–0.14 (Cd), 7.29–13.22 (As), 0.28–0.62 (Ni) mg/kg for raw biomass. For unit energy delivered to cooking vessels, the EFs ranged 0.42–0.77 (Pb), 0.79–1.16 (Cu), 0.01–0.03 (Cd), 1.93–5.09 (As), 0.08–0.19 mg/MJ (Ni) for pellets, and 0.30–0.56 (Pb), 0.41–1.86 (Cu), 0.04–0.06 (Cd), 3.25–5.49 (As), 0.12–0.26 (Ni) mg/MJ for raw biomass. This study found that moisture, volatile matter and modified combustion efficiency were the important factors affecting metal emissions. Comparisons of the mass-based and task-based EFs found that biomass pellets produced higher metal emissions than the same amount of raw biomass. However, metal emissions from pellets were not higher in terms of unit energy delivered. PMID:25002204

  13. Forced-to-natural convection transition tests in parallel simulated liquid metal reactor fuel assemblies

    SciTech Connect

    Levin, A.E. ); Montgomery, B.H. )

    1990-01-01

    The Thermal-Hydraulic Out of Reactor Safety (THORS) Program at Oak Ridge National Laboratory (ORNL) had as its objective the testing of simulated, electrically heated liquid metal reactor (LMR) fuel assemblies in an engineering-scale, sodium loop. Between 1971 and 1985, the THORS Program operated 11 simulated fuel bundles in conditions covering a wide range of normal and off-normal conditions. The last test series in the Program, THORS-SHRS Assembly 1, employed two parallel, 19-pin, full-length, simulated fuel assemblies of a design consistent with the large LMR (Large Scale Prototype Breeder -- LSPB) under development at that time. These bundles were installed in the THORS Facility, allowing single- and parallel-bundle testing in thermal-hydraulic conditions up to and including sodium boiling and dryout. As the name SHRS (Shutdown Heat Removal System) implies, a major objective of the program was testing under conditions expected during low-power reactor operation, including low-flow forced convection, natural convection, and forced-to-natural convection transition at various powers. The THORS-SHRS Assembly 1 experimental program was divided up into four phases. Phase 1 included preliminary and shakedown tests, including the collection of baseline steady-state thermal-hydraulic data. Phase 2 comprised natural convection testing. Forced convection testing was conducted in Phase 3. The final phase of testing included forced-to-natural convection transition tests. Phases 1, 2, and 3 have been discussed in previous papers. The fourth phase is described in this paper. 3 refs., 2 figs.

  14. Environmentally Friendly Carbon-Preserving Recovery of Noble Metals From Supported Fuel Cell Catalysts.

    PubMed

    Latsuzbaia, R; Negro, E; Koper, G J M

    2015-06-08

    The dissolution of noble-metal catalysts under mild and carbon-preserving conditions offers the possibility of in situ regeneration of the catalyst nanoparticles in fuel cells or other applications. Here, we report on the complete dissolution of the fuel cell catalyst, platinum nanoparticles, under very mild conditions at room temperature in 0.1 M HClO4 and 0.1 M HCl by electrochemical potential cycling between 0.5-1.1 V at a scan rate of 50 mV s(-1) . Dissolution rates as high as 22.5 μg cm(-2) per cycle were achieved, which ensured a relatively short dissolution timescale of 3-5 h for a Pt loading of 0.35 mg cm(-2) on carbon. The influence of chloride ions and oxygen in the electrolyte on the dissolution was investigated, and a dissolution mechanism is proposed on the basis of the experimental observations and available literature results. During the dissolution process, the corrosion of the carbon support was minimal, as observed by X-ray photoelectron spectroscopy (XPS). © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Highly stable precious metal-free cathode catalyst for fuel cell application

    NASA Astrophysics Data System (ADS)

    Serov, Alexey; Workman, Michael J.; Artyushkova, Kateryna; Atanassov, Plamen; McCool, Geoffrey; McKinney, Sam; Romero, Henry; Halevi, Barr; Stephenson, Thomas

    2016-09-01

    A platinum group metal-free (PGM-free) oxygen reduction reaction (ORR) catalyst engineered for stability has been synthesized using the sacrificial support method (SSM). This catalyst was comprehensively characterized by physiochemical analyses and tested for performance and durability in fuel cell membrane electrode assemblies (MEAs). This catalyst, belonging to the family of Fe-N-C materials, is easily scalable and can be manufactured in batches up to 200 g. The fuel cell durability tests were performed in a single cell configuration at realistic operating conditions of 0.65 V, 1.25 atmgauge air, and 90% RH for 100 h. In-depth characterization of surface chemistry and morphology of the catalyst layer before and after durability tests were performed. The failure modes of the PGM-free electrodes were derived from structure-to-property correlations. It is suggested that under constant voltage operation, the performance loss results from degradation of the electrode pore structure, while under carbon corrosion accelerated test protocols the failure mode is catalyst corrosion.

  16. The thermodynamics of pyrochemical processes for liquid metal reactor fuel cycles

    SciTech Connect

    Johnson, I.

    1987-01-01

    The thermodynamic basis for pyrochemical processes for the recovery and purification of fuel for the liquid metal reactor fuel cycle is described. These processes involve the transport of the uranium and plutonium from one liquid alloy to another through a molten salt. The processes discussed use liquid alloys of cadmium, zinc, and magnesium and molten chloride salts. The oxidation-reduction steps are done either chemically by the use of an auxiliary redox couple or electrochemically by the use of an external electrical supply. The same basic thermodynamics apply to both the salt transport and the electrotransport processes. Large deviations from ideal solution behavior of the actinides and lanthanides in the liquid alloys have a major influence on the solubilities and the performance of both the salt transport and electrotransport processes. Separation of plutonium and uranium from each other and decontamination from the more noble fission product elements can be achieved using both transport processes. The thermodynamic analysis is used to make process design computations for different process conditions.

  17. Performance of liquid metal reactor fuel pins with D9 cladding

    SciTech Connect

    Makenas, B.J.; Hales, J.W.

    1985-05-01

    The use of 316 stainless steel (SS) for Liquid Metal Fast Reactor applications is limited because of its tendency to swell significantly under neutron irradiation. Consequently, a number of alloys have been proposed as advanced cladding materials including precipitation hardened alloys, ferritic materials, and titanium modified versions of austenitic 316 SS. One of the latter type of alloys is called and is similar in composition to 316 SS but with titanium additions of approx.0.25%. Three mixed-oxide (U,Pu)O/sub 2/ fuel tests containing D9-clad pins have been successfully irradiated in EBR-II. They have demonstrated significantly lower swelling for D9 than for the reference 316 SS cladding and have shown that the behavior of D9 is very similar to 316 SS with respect to other properties important to reactor design. In two of the tests (designated P43 and P44), D9 was irradiated side-by-side with various other cladding materials. Two different variations of D9 (differing primarily in molybdenum), two cladding cold work levels, and two fuel smeared densities (85% and 89% TD) were explored. The third test, P45, was made up exclusively of 20% CW D9-clad pins.

  18. Phase Characteristics of a Number of U-Pu-Am-Np-Zr Metallic Alloys for Use as Fast Reactor Fuels

    SciTech Connect

    Douglas E. Burkes; J. Rory Kennedy; Thomas Hartmann; Cynthia A. Papesch; Denis D. Keiser, Jr.

    2010-01-01

    Metallic fuel alloys consisting of uranium, plutonium, and zirconium with minor additions of americium and neptunium are under evaluation for potential use to transmute long-lived transuranic actinide isotopes in fast reactors. A series of test designs for the Advanced Fuel Cycle Initiative (AFCI) have been irradiated in the Advanced Test Reactor (ATR), designated as the AFC-1 and AFC-2 designs. Metal fuel compositions in these designs have included varying amounts of U, Pu, Zr, and minor actinides (Am, Np). Investigations into the phase behavior and relationships based on the alloy constituents have been conducted using x-ray diffraction and differential thermal analysis. Results of these investigations, along with proposed relationships between observed behavior and alloy composition, are provided. In general, observed behaviors can be predicted by a ternary U-Pu-Zr phase diagram, with transition temperatures being most dependent on U content. Furthermore, the enthalpy associated with transitions is strongly dependent on the as-cast microstructural characteristics.

  19. Phase characteristics of a number of U-Pu-Am-Np-Zr metallic alloys for use as fast reactor fuels

    NASA Astrophysics Data System (ADS)

    Burkes, Douglas E.; Kennedy, J. Rory; Hartmann, Thomas; Papesch, Cynthia A.; Keiser, Dennis D., Jr.

    2010-01-01

    Metallic fuel alloys consisting of uranium, plutonium, and zirconium with minor additions of americium and neptunium are under evaluation for potential use to transmute long-lived transuranic actinide isotopes in fast reactors. A series of test designs for the Advanced Fuel Cycle Initiative (AFCI) have been irradiated in the Advanced Test Reactor (ATR), designated as the AFC-1 and AFC-2 designs. Metal fuel compositions in these designs have included varying amounts of U, Pu, Zr, and minor actinides (Am, Np). Investigations into the phase behavior and relationships based on the alloy constituents have been conducted using X-ray diffraction and differential thermal analysis. Results of these investigations, along with proposed relationships between observed behavior and alloy composition, are provided. In general, observed behaviors can be predicted by a ternary U-Pu-Zr phase diagram, with transition temperatures being most dependent on U content. Furthermore, the enthalpy associated with transitions is strongly dependent on the as-cast microstructural characteristics.

  20. Report on Development of Concepts for the Advanced Casting System in Support of the Deployment of a Remotely Operable Research Scale Fuel Fabrication Facility for Metal Fuel

    SciTech Connect

    Ken Marsden

    2007-03-01

    Demonstration of recycle processes with low transuranic losses is key to the successful implementation of the Global Nuclear Energy Partnership strategy to manage spent fuel. It is probable that these recycle processes will include remote fuel fabrication. This report outlines the strategy to develop and implement a remote metal fuel casting process with minimal transuranic losses. The approach includes a bench-scale casting system to develop materials, methods, and perform tests with transuranics, and an engineering-scale casting system to demonstrate scalability and remote operability. These systems will be built as flexible test beds allowing exploration of multiple fuel casting approaches. The final component of the remote fuel fabrication demonstration culminates in the installation of an advanced casting system in a hot cell to provide integrated remote operation experience with low transuranic loss. Design efforts and technology planning have begun for the bench-scale casting system, and this will become operational in fiscal year 2008, assuming appropriate funding. Installation of the engineering-scale system will follow in late fiscal year 2008, and utilize materials and process knowledge gained in the bench-scale system. Assuming appropriate funding, the advanced casting system will be installed in a remote hot cell at the end of fiscal year 2009.

  1. Multi-unit inertial fusion plants based on HYLIFE-II, with shared heavy-ion RIA driver and target factory, producing electricity and hydrogen fuel

    SciTech Connect

    Logan, G.; Moir, R.; Hoffman, M.

    1994-05-05

    Following is a modification of the IFEFUEL systems code, called IFEFUEL2, to treat specifically the HYLIFE-II target chamber concept. The same improved Recirculating Induction Accelerator (RIA) energy scaling model developed recently by Bieri is used in this survey of the economics of multi-unit IFE plants producing both electricity and hydrogen fuel. Reference cases will assume conventional HI-indirect target gains for a 2 mm spot, and improved HYLIFE-II BoP models as per Hoffman. Credits for improved plant availability and lower operating costs due to HYLIFE-II`s 30-yr target chamber lifetime are included, as well as unit cost reductions suggested by Delene to credit greater {open_quotes}learning curve{close_quotes} benefits for the duplicated portions of a multi-unit plant. To illustrate the potential impact of more advanced assumptions, additional {open_quotes}advanced{close_quotes} cases will consider the possible benefits of an MHD + Steam BoP, where direct MHD conversion of plasma from baseball-size LiH target blanket shells is assumed to be possible in a new (as yet undesigned) liquid Flibe-walled target chamber, together and separately, with advanced, higher-gain heavy-ion targets with Fast Ignitors. These runs may help decide the course of a possible future {open_quotes}HYLIFE-III{close_quotes} IFE study. Beam switchyard and final focusing system costs per target chamber are assumed to be consistent with single-sided illumination, for either {open_quotes}conventional{close_quotes} or {open_quotes}advanced{close_quotes} indirect target gain assumptions. Target costs are scaled according to the model by Woodworth. In all cases, the driver energy and rep rate for each chosen number of target chambers and total plant output will be optimized to minimize the cost of electricity (CoE) and the associated cost of hydrogen (CoH), using a relationship between CoE and CoH to be presented in the next section.

  2. A separate effect study of the influence of metallic fission products on CsI radioactive release from nuclear fuel

    NASA Astrophysics Data System (ADS)

    Di Lemma, F. G.; Colle, J. Y.; Beneš, O.; Konings, R. J. M.

    2015-10-01

    The chemistry of cesium and iodine is of main importance to quantify the radioactive release in case of a nuclear reactor accident, or sabotage involving irradiated nuclear materials. We studied the interaction of CsI with different metallic fission products such as Mo and Ru. These elements can be released from nuclear fuel when exposed to oxidising conditions, as in the case of contact of overheated nuclear fuel with air (e.g. in a spent fuel cask sabotage, uncovering of a spent fuel pond, or air ingress accidents). Experiments were performed by vaporizing mixtures of the compounds in air, and analysing the produced aerosols in view of a possible gas-gas and gas-aerosol reactions between the compounds. These results were compared with the gaseous species predicted by thermochemical equilibrium calculations and experimental equilibrium vaporization tests using Knudsen Effusion Mass Spectrometry.

  3. Behavior of low-burnup metallic fuels for the integral fast reactor at elevated temperatures in ex-reactor tests

    SciTech Connect

    Tsai, Hanchung; Liu, Yung Y.; Wang, Da-Yung; Kramer, J.M.

    1991-07-01

    A series of ex-reactor heating tests on low burnup U-26wt.%Pu-10wt.%Zr metallic fuel for the PRISM reactor was conducted to evaluate fuel/cladding metallurgical interaction and its effect on cladding integrity at elevated temperatures. The reaction between the fuel and cladding caused liquid-phase formation and dissolution of the inner surface of the cladding. The rate of cladding penetration was below the existing design correlation, which provides a conservative margin to cladding failure. In a test which enveloped a wide range of postulated reactor transient events, a substantial temporal cladding integrity margin was demonstrated for an intact, whole fuel pin. The cause of the eventual pin breach was reaction-induced cladding thinning combined with fission-gas pressure loading. The behavior of the breached pin was benign. 7 refs., 7 figs., 1 tab.

  4. A novel Ni/ceria-based anode for metal-supported solid oxide fuel cells

    NASA Astrophysics Data System (ADS)

    Rojek-Wöckner, Veronika A.; Opitz, Alexander K.; Brandner, Marco; Mathé, Jörg; Bram, Martin

    2016-10-01

    For optimization of ageing behavior, electrochemical performance, and sulfur tolerance of metal-supported solid oxide fuel cells a new anode concept is introduced, which is based on a Ni/GDC cermet replacing the established Ni/YSZ anodes. In the present work optimized processing parameters compatible with MSC substrates are specified by doing sintering studies on pressed bulk specimen and on real porous anode structures. The electrochemical performance of the Ni/GDC anodes was characterized by means of symmetrical electrolyte supported model-type cells. In this study, three main objectives are pursued. Firstly, the effective technical realization of the Ni/GDC concept is demonstrated. Secondly, the electrochemical behavior of Ni/GDC porous anodes is characterized by impedance spectroscopy and compared with the current standard Ni/YSZ anode. Further, a qualitative comparison of the sulfur poisoning behavior of both anode types is presented. Thirdly, preliminary results of a successful implementation of the Ni/GDC cermet into a metal-supported single cell are presented.

  5. Long-term stability of metal-supported solid oxide fuel cells employing infiltrated electrodes

    NASA Astrophysics Data System (ADS)

    Zhou, Yucun; Chen, Ting; Li, Junliang; Yuan, Chun; Xin, Xianshuang; Chen, Guoyi; Miao, Guoshuan; Zhan, Weiting; Zhan, Zhongliang; Wang, Shaorong

    2015-11-01

    Here, stability of the metal-supported solid oxide fuel cell (MS-SOFC) with Ni-Ce0.8Sm0.2O2-δ (SDC) infiltrated 430L anode and La0.6Sr0.4Fe0.9Sc0.1O3-δ (LSFSc) infiltrated scandia-stabilized zirconia (SSZ) cathode is evaluated. It is found that the degradation rate defined as the voltage loss during a fixed period is faster at higher operation temperatures and larger current densities. Scanning electron microscopy (SEM) and energy dispersive X-ray spectra (EDS) analysis indicate that the degradation is mainly caused by the morphological change of the anode while metal element diffusion between Ni catalyst and 430L substrate contributes little. A 1500 h durability test measured at 650 °C and 0.9 A cm-2 shows a degradation rate of 1.3% kh-1 and the voltage decrease is mainly found in the initial 500 h.

  6. Metal-organic frameworks for removal of Xe and Kr from nuclear fuel reprocessing plants.

    PubMed

    Liu, Jian; Thallapally, Praveen K; Strachan, Denis

    2012-08-07

    Removal of xenon (Xe) and krypton (Kr) from process off-gases containing 400 ppm Xe, 40 ppm Kr, 78% N(2), 21% O(2), 0.9% Ar, 0.03% CO(2), and so forth using adsorption was demonstrated for the first time. Two well-known metal-organic frameworks (MOFs), HKUST-1 and Ni/DOBDC, which both have unsaturated metal centers but different pore morphologies, were selected as novel adsorbents. Results of an activated carbon were also included for comparison. The Ni/DOBDC has higher Xe/Kr selectivities than those of the activated carbon and the HKUST-1. In addition, results show that the Ni/DOBDC and HKUST-1 can adsorb substantial amounts of Xe and Kr even when they are mixed in air. Moreover, the Ni/DOBDC can successfully separate 400 ppm Xe from 40 ppm Kr and air containing O(2), N(2), and CO(2) with a Xe/Ke selectivity of 7.3 as indicated by our breakthrough results. This shows a promising future for MOFs in radioactive nuclide separations from spent fuels.

  7. Mechanical reliability and life prediction of coated metallic interconnects within solid oxide fuel cells

    DOE PAGES

    Xu, Zhijie; Xu, Wei; Stephens, Elizabeth; ...

    2017-07-03

    Metallic cell interconnects (IC) made of ferritic stainless steels, i.e., iron-based alloys, have been increasingly favored in the recent development of planar solid oxide fuel cells (SOFCs) because of their advantages in excellent imperviousness, low electrical resistance, ease in fabrication, and cost effectiveness. Typical SOFC operating conditions inevitably lead to the formation of oxide scales on the surface of ferritic stainless steel, which could cause delamination, buckling, and spallation resulting from the mismatch of the coefficient of thermal expansion and eventually reduce the lifetime of the interconnect components. Various protective coating techniques have been applied to alleviate these drawbacks. Inmore » the present work, a fracture-mechanics-based quantitative modeling framework has been established to predict the mechanical reliability and lifetime of the spinel-coated, surface-modified specimens under an isothermal cooling cycle. Analytical solutions have been formulated to evaluate the scale/substrate interfacial strength and determine the critical oxide thickness in terms of a variety of design factors, such as coating thickness, material properties, and uncertainties. In conclusion, the findings then are correlated with the experimentally measured oxide scale growth kinetics to quantify the predicted lifetime of the metallic interconnects.« less

  8. Some computations in planning reconstitution of a 500-MW(electric) fast breeder reactor (metallic) fuel by electrorefining

    SciTech Connect

    Nawada, H.P.; Bhat, N.P.; Balasubramanian, G.R.

    1996-04-01

    To compare and evaluate various fuel cycle options for a 500-MW(electric) fast breeder reactor, the electrorefining process has been examined for reprocessing spent fuel. Making use of an improved thermochemical model, optimum process conditions for electrorefining have been worked out. These conditions are the following: capacity of the electrorefining cell, number of cells, batch size, feed adjustments, sequential operations for recovery of uranium and co-recovery of uranium and plutonium, number of cycles, and time frame to meet the refueling schedule. The spent fuel is envisaged to undergo reprocessing in three campaigns: (a) the inner core campaign, (b) the outer core campaign, and (c) the blanket and the leftover campaign. Feed adjustments are done by mixing either the spent inner core or the outer core fuels with the blankets. Three product streams with required fuel composition for direct refabrication of the inner core, the outer core, and the blanket fuel subassemblies, respectively, are obtained by certain sequential electrorefiing operations. These calculations made for a mixed-oxide fuel core can be easily extended to the metallic core.

  9. Processing and Properties of Metallic Foams for Solid-Oxide Fuel Cell Interconnects

    NASA Astrophysics Data System (ADS)

    Scott, Justin Aaron

    Metallic foams possess a unique array of mechanical, thermal, and acoustic properties that have led to an increasing portfolio of potential applications. One of the newest additions includes solid-oxide fuel cells (SOFCs), where commercialization hinges on the development of improved materials and designs that can withstand the severe operational requirements of high temperature (up to 850 °C) and long service lifetimes (>10,000 hours). These demands place strict design limitations on the interconnect, which serves as a current path and fluid barrier between fuel and oxidant gases in the SOFC stack. Materials with excellent oxidation and creep resistance are sought. Chromia-forming Iron and Nickel-based alloy families have shown the most promise in preliminary studies. While a wealth of knowledge is available on these alloys as dense interconnects, limited research has also explored the option of porous metallic interconnects that offer the potential for cheaper, lightweight, and more mechanically robust stacks. This thesis aims to provide a more thorough examination of porous metallic interconnect construction beginning with refinement of the place-holder replication techniques to create fully-interconnected, open porosity in a E-Brite (Fe-26Cr-1Mo, wt.%) and J5 (Ni-22.5Mo-12.5Cr-1Ti-0.5Mn-0.1Al-0.1Y, wt.%) alloy. Mechanical response of the E-Brite was examined at room temperature and found good agreement with existing, beam-based models for stiffness and yield strength. High temperature mechanical deformation was also recorded and a creep strengthening effect due to the formation of oxide was characterized. Electrochemical properties of porous E-Brite including the activation energy of oxide formation and area-specific resistance were also determined and found to be comparable to existing literature on bulk response. Finite element modeling (FEM) of the creep of unoxidized and oxidized E-Brite was also performed and successfully captured the qualitative behavior

  10. Synthesis of graphene-supported noble metal hybrid nanostructures and their applications as advanced electrocatalysts for fuel cells.

    PubMed

    Zhu, Chengzhou; Dong, Shaojun

    2013-11-21

    Graphene (GN) is an emerging carbon material that may soon find practical applications. With its unusual properties, GN is an ideal platform for constructing a series of GN-based functional nanomaterials. Among them, GN/noble metal hybrids become one of the families of composite materials with extraordinary properties by combining the advantages of noble metal nanostructures and GN. The recent progress in the synthesis of GN/noble metal hybrids is presented first, such as in situ solution based methods, electrochemical deposition methods, self-assembly and other methods. Then, the applications of these novel GN/noble metal hybrids in fuel cells are summarized and discussed. Future research trends and challenges of design and synthesis of GN/noble metal hybrids are proposed.

  11. Investigation of Redox Metal Oxides for Carbonaceous Fuel Conversion and CO2 Capture

    NASA Astrophysics Data System (ADS)

    Galinsky, Nathan Lee

    The chemical looping combustion (CLC) process uses metal oxides, also referred to as oxygen carriers, in a redox scheme for conversion of carbonaceous fuels into a concentrated stream of CO2 and steam while also producing heat and electricity. The unique redox scheme of CLC allows CO2 capture with minimal energy penalty. The CLC process performance greatly depends on the oxygen carrier that is chosen. To date, more than 1000 oxygen carriers have been developed for chemical-looping processes using metal oxides containing first-row transition metals. Oxygen carriers are typically mixed with an inert ceramic support to improve their overall mechanical stability and recyclability. This study focuses on design of (i) iron oxide oxygen carriers for conversion of gaseous carbonaceous fuels and (ii) development of perovskite CaMnO 3-d with improved stability and redox properties for conversion of solid fuels. Iron oxide is cheap and environmentally benign. However, it suffers from low activity with carbonaceous fuels due partially to the low ionic conductivity of iron oxides. In order to address the low activity of iron-oxide-based oxygen carriers, support addition has been shown to lower the energy barrier of oxygen anion transport within the oxygen carrier. This work adds a mixed-ionic-and-electronic-conductor (MIEC) support to iron oxide to help facilitate O2- transport inside the lattice of iron oxide. The MIEC-supported iron oxide is compared to commonly used supports including TiO2 and Al2O 3 and the pure ionic conductor support yttria-stabilized zirconia (YSZ) for conversion of different carbonaceous fuels and hydrogen. Results show that the MIEC-supported iron oxide exhibits up to 70 times higher activity than non-MIEC-supported iron oxides for methane conversion. The MIEC supported iron oxide also shows good recyclability with only minor agglomeration and carbon formation observed. The effect of support-iron oxide synergies is further investigated to understand

  12. SrFe0.75Mo0.25O3-δ impregnated 430L alloys for efficient fuel oxidation in metal supported solid oxide fuel cells

    NASA Astrophysics Data System (ADS)

    Zhou, Yucun; Meng, Xie; Yuan, Chun; Luo, Ting; Ye, Xiaofeng; Li, Junliang; Wang, Shaorong; Zhan, Zhongliang

    2014-12-01

    Here we report a novel SrFe0.75Mo0.25O3-δ (SFMO)-430L composite anode for the application in the metal supported solid oxide fuel cells. Such an anode is prepared by coating a thin nano porous and mixed electronic-ionic conducting SFMO layer onto the internal surface of a micron porous 430L alloy backbone. The area specific polarization resistance of the composite anode for hydrogen oxidation can be as low as 0.11 Ω cm2 at 800 °C. The electronic conductivity of the 430L alloy support is found to be critically important for promoting rapid hydrogen oxidation kinetics and attaining such a low polarization resistance as the fuel cell anode. A metal-supported fuel cell with the SFMO impregnated 430L composite anode exhibits outstanding power densities at 800 °C, e.g., 0.81 W cm-2 in hydrogen and 0.31 W cm-2 in iso-octane. Preliminary results show that the present SFMO-430L composite anode exhibits much higher tolerance for coking formation than the traditional Ni-based anode.

  13. Dynamic evaluation of low-temperature metal-supported solid oxide fuel cell oriented to auxiliary power units

    NASA Astrophysics Data System (ADS)

    Wang, Zhenwei; Berghaus, Jörg Oberste; Yick, Sing; Decès-Petit, Cyrille; Qu, Wei; Hui, Rob; Maric, Radenka; Ghosh, Dave

    A metal-supported solid oxide fuel cell (SOFC) composed of a Ni-Ce 0.8Sm 0.2O 2- δ (Ni-SDC) cermet anode and an SDC electrolyte was fabricated by suspension plasma spraying on a Hastelloy X substrate. The cathode, an Sm 0.5Sr 0.5CoO 3 (SSCo)-SDC composite, was screen-printed and fired in situ. The dynamic behaviour of the cell was measured while subjected to complete fuel shutoff and rapid start-up cycles, as typically encountered in auxiliary power units (APU) applications. A promising performance - with a maximum power density (MPD) of 0.176 W cm -2 at 600 °C - was achieved using humidified hydrogen as fuel and air as the oxidant. The cell also showed excellent resistance to oxidation at 600 °C during fuel shutoff, with only a slight drop in performance after reintroduction of the fuel. The Cr and Mn species in the Hastelloy X alloy appeared to be preferentially oxidized while the oxidation of nickel in the metallic substrate was temporarily alleviated. In rapid start-up cycles with a heating rate of 60 °C min -1, noticeable performance deterioration took place in the first two thermal cycles, and then continued at a much slower rate in subsequent cycles. A postmortem analysis of the cell suggested that the degradation was mainly due to the mismatch of the thermal expansion coefficient across the cathode/electrolyte interface.

  14. Effect of central metal ions of analogous metal-organic frameworks on the adsorptive removal of benzothiophene from a model fuel.

    PubMed

    Khan, Nazmul Abedin; Jhung, Sung Hwa

    2013-09-15

    Liquid phase adsorption of benzothiophene (BT) has been studied over CuCl₂-loaded analogous metal-organic frameworks (MOFs), metal-benzenedicarboxylates (Me-BDCs, Me: Al, Cr and V), to understand the effect of central metal ions on the adsorptive removal of BT from a model fuel. Among the central metal ions (Al(3+), Cr(3+) and V(3+)) of the Me-BDCs only V(3+) was oxidized by the loaded CuCl₂ (or Cu(2+)) at ambient condition resulting in V(4+) and Cu(+) species. Different from the CuCl₂-loaded Al- and Cr-BDCs, the CuCl₂/V-BDC adsorbed BT remarkably well compared to the virgin V-BDCs which suggests a specific favorable interaction (π-complexation) between the obtained Cu(+) in the CuCl₂/V-BDC and BT.

  15. Retrieval of Au, Ag, Cu precious metals coupled with electric energy production via an unconventional coupled redox fuel cell reactor.

    PubMed

    Zhang, Hui-Min; Fan, Zheng; Xu, Wei; Feng, Xiao; Wu, Zu-Cheng

    2017-09-15

    The recovery of heavy metals from aqueous solutions or e-wastes is of upmost importance. Retrieval of Au, Ag, and Cu with electricity generation through building an ethanol-metal coupled redox fuel cells (CRFCs) is demonstrated. The cell was uniquely assembled on PdNi/C anode the electro-oxidation of ethanol takes place to give electrons and then go through the external circuit reducing metal ions to metallic on the cathode, metals are recovered. Taking an example of removal of 100mgL(-1) gold in 0.5M HAc-NaAc buffer solution as the catholyte, 2.0M ethanol in 1.0M alkaline solution as the anolyte, an open circuit voltage of 1.4V, more than 96% of gold removal efficiency in 20h, and equivalent energy production of 2.0kWhkg(-1) of gold can be readily achieved in this system. When gold and copper ions coexist, it was confirmed that metallic Cu is formed on the cathodic electrode later than metallic Au formation by XPS analysis. Thus, this system can achieve step by step electrodeposition of gold and copper while the two metal ions coexisting. This work develops a new approach to retrieve valuable metals from aqueous solution or e-wastes. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. As-cast uranium-molybdenum based metallic fuel candidates and the effects of carbon addition

    NASA Astrophysics Data System (ADS)

    Blackwood, Van Stephen

    The objective of this research was to develop and recommend a metallic nuclear fuel candidate that lowered the onset temperature of gamma phase formation comparable or better than the uranium-10 wt. pct. molybdenum alloy, offered a solidus temperature as high or higher than uranium-10 wt. pct. zirconium (1250°C), and stabilized the fuel phase against interaction with iron and steel at least as much as uranium-10 wt. pct. zirconium stabilized the fuel phase. Two new as-cast alloy compositions were characterized to assess thermal equilibrium boundaries of the gamma phase field and the effect of carbon addition up to 0.22 wt. pct. The first system investigated was uranium- x wt. pct. M where x ranged between 5-20 wt. pct. M was held at a constant ratio of 50 wt. pct. molybdenum, 43 wt. pct. titanium, and 7 wt. pct. zirconium. The second system investigated was the uranium-molybdenum-tungsten system in the range 90 wt. pct. uranium - 10 wt. pct. molybdenum - 0 wt. pct. tungsten to 80 wt. pct. uranium - 10 wt. pct. molybdenum - 10 wt. pct. tungsten. The results showed that the solidus temperature increased with increased addition of M up to 12.5 wt. pct. for the uranium-M system. Alloy additions of titanium and zirconium were removed from uranium-molybdenum solid solution by carbide formation and segregation. The uranium-molybdenum-tungsten system solidus temperature increased to 1218°C at 2.5 wt. pct. with no significant change in temperature up to 5 wt. pct. tungsten suggesting the solubility limit of tungsten had been reached. Carbides were observed with surrounding areas enriched in both molybdenum and tungsten. The peak solidus temperatures for the alloy systems were roughly the same at 1226°C for the uranium-M system and 1218°C for the uranium-molybdenum-tungsten system. The uranium-molybdenum-tungsten system required less alloy addition to achieve similar solidus temperatures as the uranium-M system.

  17. Study on laser welding of fuel clad tubes and end plugs made of modified 9Cr-1Mo steel for metallic fuel of Fast Breeder Reactors

    NASA Astrophysics Data System (ADS)

    Harinath, Y. V.; Gopal, K. A.; Murugan, S.; Albert, S. K.

    2013-04-01

    A procedure for Pulsed Laser Beam Welding (PLBW) has been developed for fabrication of fuel pins made of modified 9Cr-1Mo steel for metallic fuel proposed to be used in future in India's Fast Breeder Reactor (FBR) programme. Initial welding trials of the samples were carried out with different average power using Nd-YAG based PLBW process. After analyzing the welds, average power for the weld was optimized for the required depth of penetration and weld quality. Subsequently, keeping the average power constant, the effect of various other welding parameters like laser peak power, pulse frequency, pulse duration and energy per pulse on weld joint integrity were studied and a procedure that would ensure welds of acceptable quality with required depth of penetration, minimum size of fusion zone and Heat Affected Zone (HAZ) were finalized. This procedure is also found to reduce the volume fraction delta-ferrite in the fusion zone.

  18. Recycling Of Uranium- And Plutonium-Contaminated Metals From Decommissioning Of The Hanau Fuel Fabrication Plant

    SciTech Connect

    Kluth, T.; Quade, U.; Lederbrink, F. W.

    2003-02-26

    Decommissioning of a nuclear facility comprises not only actual dismantling but also, above all, management of the resulting residual materials and waste. Siemens Decommissioning Projects (DP) in Hanau has been involved in this task since 1995 when the decision was taken to decommission and dismantle the Hanau Fuel Fabrication Plant. Due to the decommissioning, large amounts of contaminated steel scrap have to be managed. The contamination of this metal scrap can be found almost exclusively in the form of surface contamination. Various decontamination technologies are involved, as there are blasting and wiping. Often these methods are not sufficient to meet the free release limits. In these cases, SIEMENS has decided to melt the scrap at Siempelkamp's melting plant. The plant is licensed according to the German Radiation Protection Ordinance Section 7 (issue of 20.07.2001). The furnace is a medium frequency induction type with a load capacity of 3.2 t and a throughput of 2 t/h for steel melting. For safety reasons, the furnace is widely operated by remote handling. A highly efficient filter system of cyclone, bag filter and HEPA-filter in two lines retains the dust and aerosol activity from the off-gas system. The slag is solidified at the surface of the melt and gripped before pouring the liquid iron into a chill. Since 1989, in total 15,000 t have been molten in the plant, 2,000 t of them having been contaminated steel scrap from the decommissioning of fuel fabrication plants. Decontamination factors could be achieved between 80 and 100 by the high affinity of the uranium to the slag former. The activity is transferred to the slag up to nearly 100 %. Samples taken from metal, slag and dust are analyzed by gamma measurements of the 186 keV line of U235 and the 1001 keV line of Pa234m for U238. All produced ingots showed a remaining activity less than 1 Bq/g and could be released for industrial reuse.

  19. Enhanced Ceria Solid Electrolyte Fuel Cell Development. Reduction of Electronic Conductivity Permits use of a Solid Ceria Electrolyte in High Efficiency High Power Density Fuel Cells at Temperatures Compatible with Metallic Cell Hardware

    DTIC Science & Technology

    1990-01-01

    DTC FILE COPY DARPA ORDER 9526 lit I 0ENHANCED CERIA SOLID ELECTROLYTE FUEL CELL DEVELOPMENT Reduction of Electronic Conductivity Permits use of a...Solid Ceria Electrolyte * I’- in High Efficiency High Power Density Fuel Cells at Temperatures Compatible with Metallic Cell Hardware Prepared by D T IC...D. L. MairicleI < T International Fuel Cells D. .. Box 739 FEB 0 8 1990 195 Governors Highway D South Windsor, CT 06074 January 1990 IFCR-10824

  20. N/S-heterocyclic contaminant removal from fuels by the mesoporous metal-organic framework MIL-100: the role of the metal ion.

    PubMed

    Van de Voorde, Ben; Boulhout, Mohammed; Vermoortele, Frederik; Horcajada, Patricia; Cunha, Denise; Lee, Ji Sun; Chang, Jong-San; Gibson, Emma; Daturi, Marco; Lavalley, Jean-Claude; Vimont, Alexandre; Beurroies, Isabelle; De Vos, Dirk E

    2013-07-03

    The influence of the metal ion in the mesoporous metal trimesate MIL-100(Al(3+), Cr(3+), Fe(3+), V(3+)) on the adsorptive removal of N/S-heterocyclic molecules from fuels has been investigated by combining isotherms for adsorption from a model fuel solution with microcalorimetric and IR spectroscopic characterizations. The results show a clear influence of the different metals (Al, Fe, Cr, V) on the affinity for the heterocyclic compounds, on the integral adsorption enthalpies, and on the uptake capacities. Among several factors, the availability of coordinatively unsaturated sites and the presence of basic sites next to the coordinative vacancies are important factors contributing to the observed affinity differences for N-heterocyclic compounds. These trends were deduced from IR spectroscopic observation of adsorbed indole molecules, which can be chemisorbed coordinatively or by formation of hydrogen bonded species. On the basis of our results we are able to propose an optimized adsorbent for the deep and selective removal of nitrogen contaminants out of fuel feeds, namely MIL-100(V).

  1. Special handling and preheating requirements for IFR-1 metal fuel experiment in FFTF

    SciTech Connect

    Tsai, H; Koenig, J F

    1986-04-01

    The FFTF IFR-1 test fuel elements incorporate a sodium bond between the fuel slugs and cladding to promote heat transfer. This design feature represents a major difference from the reference mixed oxide fuel design in which helium gas is used as heat transfer media between the fuel pellets and the cladding. Because of the sodium bond, special procedures for handling and preheating of the IFR-1 fuel elements and assembly at FFTF are required. They are defined in this report. These procedures are designed to protect the integrity of the as-built sodium bond and, more importantly, to prevent inadvertent damage to the fuel element before their insertion into the reactor.

  2. Emission FTIR analyses of thin microscopic patches of jet fuel residues deposited on heated metal surfaces

    NASA Technical Reports Server (NTRS)

    Lauer, J. L.; Vogel, P.

    1986-01-01

    The relationship of fuel stability to fuel composition and the development of mechanisms for deposit formation were investigated. Fuel deposits reduce heat transfer efficiency and increase resistance to fuel flow and are highly detrimental to aircraft performance. Infrared emission Fourier transform spectroscopy was chosen as the primary method of analysis because it was sensitive enough to be used in-situ on tiny patches of monolayers or of only a few molecular layers of deposits which generally proved completely insoluble in any nondestructive solvents. Deposits of four base fuels were compared; dodecane, a dodecane/tetralin blend, commercial Jet A fuel, and a broadened-properties jet fuel particularly rich in polynuclear aromatics. Every fuel in turn was provided with and without small additions of such additives as thiophene, furan, pyrrole, and copper and iron naphthenates.

  3. Current status of the Run-Beyond-Cladding Breach (RBCB) tests for the Integral Fast Reactor (IFR). Metallic Fuels Program

    SciTech Connect

    Batte, G.L.; Pahl, R.G.; Hofman, G.L.

    1993-09-01

    This paper describes the results from the Integral Fast Reactor (IFR) metallic fuel Run-Beyond-Cladding-Breach (RBCB) experiments conducted in the Experimental Breeder Reactor II (EBR-II). Included in the report are scoping test results and the data collected from the prototypical tests as well as the exam results and discussion from a naturally occurring breach of one of the lead IFR fuel tests. All results showed a characteristic delayed neutron and fission gas release pattern that readily allows for identification and evaluation of cladding breach events. Also, cladding breaches are very small and do not propagate during extensive post breach operation. Loss of fuel from breached cladding was found to be insignificant. The paper will conclude with a brief description of future RBCB experiments planned for irradiation in EBR-II.

  4. Nuclear reactor fuel structure containing uranium alloy wires embedded in a metallic matrix plate

    DOEpatents

    Travelli, A.

    1985-10-25

    A flat or curved plate structure, to be used as fuel in a nuclear reactor, comprises elongated fissionable wires or strips embedded in a metallic continuous non-fissionable matrix plate. The wires or strips are made predominantly of a malleable uranium alloy, such as uranium silicide, uranium gallide or uranium germanide. The matrix plate is made predominantly of aluminum or an aluminum alloy. The wires or strips are located in a single row at the midsurface of the plate, parallel with one another and with the length dimension of the plate. The wires or strips are separated from each other, and from the surface of the plate, by sufficient thicknesses of matrix material, to provide structural integrity and effective fission product retention, under neutron irradiation. This construction makes it safely feasible to provide a high uranium density, so that the uranium enrichment with uranium 235 may be reduced below about 20%, to deter the reprocessing of the uranium for use in nuclear weapons.

  5. Interaction of coal-derived synthesis gas impurities with solid oxide fuel cell metallic components

    SciTech Connect

    Marina, Olga A.; Pederson, Larry R.; Coyle, Christopher A.; Edwards, Danny J.; Chou, Y. S.; Cramer, Carolyn N.

    2010-05-28

    Chromium-containing iron-based alloys Crofer22 APU and SS 441 and nickel-based alloy Inconel600, all commonly used in a solid oxide fuel cell (SOFC) stack as interconnect materials, heat exchanger and gas feeding pipes, were exposed at 700-850oC to a synthetic coal gas containing ≤2 ppm phosphine, arsine, sulfur and antimony. Samples were characterized by SEM/EDS and XRD to monitor the secondary phase formation. Exposure of ferritic stainless steels to P led to the formation of surface Cr-Mn-P-O and Fe-P-O compounds and increased temperatures accelerated the rate of interactions. Fewer interactions were observed after exposures to As and Sb. No sulfur containing compounds were found. Nickel-based alloy exhibited much stronger interactions with As and P in comparison with ferritic steels and the arsenic interactions were particularly strong. The difference between the iron- and nickel-based alloys is explained by the different chemistry and morphology of the scales grown on the alloy surfaces in coal gas. While P and As interactions with the metallic parts in the SOFC are likely to mitigate the nickel/zirconia anode poisoning, the other degradation mechanisms should be taken into consideration to avoid potential stack failures. Manganese spinels were found to be effective as phosphorus getters and could be used in coal gas cleanup.

  6. Nuclear reactor fuel structure containing uranium alloy wires embedded in a metallic matrix plate

    DOEpatents

    Travelli, Armando

    1988-01-01

    A flat or curved plate structure, to be used as fuel in a nuclear reactor, comprises elongated fissionable wires or strips embedded in a metallic continuous non-fissionable matrix plate. The wires or strips are made predominantly of a malleable uranium alloy, such as uranium silicide, uranium gallide or uranium germanide. The matrix plate is made predominantly of aluminum or an aluminum alloy. The wires or strips are located in a single row at the midsurface of the plate, parallel with one another and with the length dimension of the plate. The wires or strips are separated from each other, and from the surface of the plate, by sufficient thicknesses of matrix material, to provide structural integrity and effective fission product retention, under neutron irradiation. This construction makes it safely feasible to provide a high uranium density, so that the uranium enrichment with uranium 235 may be reduced below about 20%, to deter the reprocessing of the uranium for use in nuclear weapons.

  7. Kinetic and thermodynamic bases to resolve issues regarding conditioning of uranium metal fuels

    SciTech Connect

    Johnson, A.B.; Ballinger, R.G.; Simpson, K.A.

    1994-12-01

    Numerous uranium - bearing fuels are corroding in fuel storage pools in several countries. At facilities where reprocessing is no longer available, dry storage is being evaluated to preclude aqueous corrosion that is ongoing. It is essential that thermodynamic and kinetic factors are accounted for in transitions of corroding uranium-bearing fuels to dry storage. This paper addresses a process that has been proposed to move Hanford N-Reactor fuel from wet storage to dry storage.

  8. Effects of Dopant Metal Variation and Material Synthesis Method on the Material Properties of Mixed Metal Ferrites in Yttria Stabilized Zirconia for Solar Thermochemical Fuel Production

    DOE PAGES

    Leonard, Jeffrey; Reyes, Nichole; Allen, Kyle M.; ...

    2015-01-01

    Mixed metal ferrites have shown much promise in two-step solar-thermochemical fuel production. Previous work has typically focused on evaluating a particular metal ferrite produced by a particular synthesis process, which makes comparisons between studies performed by independent researchers difficult. A comparative study was undertaken to explore the effects different synthesis methods have on the performance of a particular material during redox cycling using thermogravimetry. This study revealed that materials made via wet chemistry methods and extended periods of high temperature calcination yield better redox performance. Differences in redox performance between materials made via wet chemistry methods were minimal andmore » these demonstrated much better performance than those synthesized via the solid state method. Subsequently, various metal ferrite samples (NiFe 2 O 4 , MgFe 2 O 4 , CoFe 2 O 4 , and MnFe 2 O 4 ) in yttria stabilized zirconia (8YSZ) were synthesized via coprecipitation and tested to determine the most promising metal ferrite combination. It was determined that 10 wt.% CoFe 2 O 4 in 8YSZ produced the highest and most consistent yields of O 2 and CO. By testing the effects of synthesis methods and dopants in a consistent fashion, those aspects of ferrite preparation which are most significant can be revealed. More importantly, these insights can guide future efforts in developing the next generation of thermochemical fuel production materials.« less

  9. Analysis of fuel options for the breakeven core configuration of the Advanced Recycling Reactor

    SciTech Connect

    Stauff, N.E.; Klim, T.K.; Taiwo, T.A.; Fiorina, C.; Franceschini, F.

    2013-07-01

    A trade-off study is performed to determine the impacts of various fuel forms on the core design and core physics characteristics of the sodium-cooled Toshiba- Westinghouse Advanced Recycling Reactor (ARR). The fuel forms include oxide, nitride, and metallic forms of U and Th. The ARR core configuration is redesigned with driver and blanket regions in order to achieve breakeven fissile breeding performance with the various fuel types. State-of-the-art core physics tools are used for the analyses. In addition, a quasi-static reactivity balance approach is used for a preliminary comparison of the inherent safety performances of the various fuel options. Thorium-fueled cores exhibit lower breeding ratios and require larger blankets compared to the U-fueled cores, which is detrimental to core compactness and increases reprocessing and manufacturing requirements. The Th cores also exhibit higher reactivity swings through each cycle, which penalizes reactivity control and increases the number of control rods required. On the other hand, using Th leads to drastic reductions in void and coolant expansion coefficients of reactivity, with the potential for enhancing inherent core safety. Among the U-fueled ARR cores, metallic and nitride fuels result in higher breeding ratios due to their higher heavy metal densities. On the other hand, oxide fuels provide a softer spectrum, which increases the Doppler effect and reduces the positive sodium void worth. A lower fuel temperature is obtained with the metallic and nitride fuels due to their higher thermal conductivities and compatibility with sodium bonds. This is especially beneficial from an inherent safety point of view since it facilitates the reactor cool-down during loss of power removal transients. The advantages in terms of inherent safety of nitride and metallic fuels are maintained when using Th fuel. However, there is a lower relative increase in heavy metal density and in breeding ratio going from oxide to metallic

  10. Impact of reducing sodium void worth on the severe accident response of metallic-fueled sodium-cooled reactors

    SciTech Connect

    Wigeland, R.A.; Turski, R.B.; Pizzica, P.A.

    1994-03-01

    Analyses have performed on the severe accident response of four 90 MWth reactor cores, all designed using the metallic fuel of the Integrated Fast Reactor (IFR) concept. The four core designs have different sodium void worth, in the range of {minus}3$ to 5$. The purpose of the investigation is to determine the improvement in safety, as measured by the severe accident consequences, that can be achieved from a reduction in the sodium void worth for reactor cores designed using the IFR concept.

  11. Separation of metallic residues from the dissolution of a high-burnup BWR fuel using nitrogen trifluoride

    SciTech Connect

    McNamara, Bruce K.; Buck, Edgar C.; Soderquist, Chuck Z.; Smith, Frances N.; Mausolf, Edward J.; Scheele, Randall D.

    2014-03-23

    Nitrogen trifluoride (NF3) was used to fluorinate the metallic residue from the dissolution of a high burnup, boiling water reactor fuel (~70 MWd/kgU). The metallic residue included the noble metal phase (containing ruthenium, rhodium, palladium, technetium, and molybdenum), and smaller amounts of zirconium, selenium, tellurium, and silver. Exposing the noble metal phase to 10% NF3 in argon between 400 and 550°C, removed molybdenum and technetium near 400°C as their volatile fluorides, and ruthenium near 500C as its volatile fluoride. The events were thermally and temporally distinct and the conditions specified are a recipe to separate these transition metals from each other and from the noble metal phase nonvolatile residue. Depletion of the volatile fluorides resulted in substantial exothermicity. Thermal excursion behavior was recorded under non-adiabatic, isothermal conditions that typically minimize heat release. Physical characterization of the metallic noble phase and its thermal behavior are consistent with high kinetic velocity reactions encouraged by the nanoparticulate phase or perhaps catalytic influences of the mixed platinum metals with nearly pure phase structure. Post-fluorination, only two phases were present in the residual nonvolatile fraction. These were identified as a nano-crystalline, metallic palladium cubic phase and a hexagonal rhodium trifluoride (RhF3) phase. The two phases were distinct as the sub-µm crystallites of metallic palladium were in contrast to the RhF3 phase, which grew from the parent nano-crystalline noble-metal phase during fluorination, to acicular crystals exceeding 20-µm in length.

  12. A review of composite and metallic bipolar plates in proton exchange membrane fuel cell: Materials, fabrication, and material selection

    NASA Astrophysics Data System (ADS)

    Taherian, Reza

    2014-11-01

    Proton exchange membrane (PEM) fuel cells offer exceptional potential for a clean, efficient, and reliable power source. The bipolar plate (BP) is a key component in this device, as it connects each cell electrically, supplies reactant gases to both anode and cathode, and removes reaction products from the cell. BPs have primarily been fabricated from high-density graphite, but in recent years, much attention has been paid to develop the cost-effective and feasible alternative materials. Recently, two different classes of materials have been attracted attention: metals and composite materials. This paper offers a comprehensive review of the current researches being carried out on the metallic and composite BPs, covering materials and fabrication methods. In this research, the phenomenon of ionic contamination due to the release of the corrosion products of metallic BP and relative impact on the durability as well as performance of PEM fuel cells is extensively investigated. Furthermore, in this paper, upon several effective parameters on commercialization of PEM fuel cells, such as stack cost, weight, volume, durability, strength, ohmic resistance, and ionic contamination, a material selection is performed among the most common BPs currently being used. This material selection is conducted by using Simple Additive Weighting Method (SAWM).

  13. Development of remote disassembly technology for liquid-metal reactor (LMR) fuel

    SciTech Connect

    Bradley, E.C.; Evans, J.H.; Metz, C.F. III; Weil, B.S.

    1990-01-01

    A major objective of the Consolidated Fuel Reprocessing Program (CFRP) is to develop equipment and demonstrate technology to reprocess fast breeder reactor fuel. Experimental work on fuel disassembly cutting methods began in the 1970s. High-power laser cutting was selected as the preferred cutting method for fuel disassembly. Remotely operated development equipment was designed, fabricated, installed, and tested at Oak Ridge National Laboratory (ORNL). Development testing included remote automatic operation, remote maintenance testing, and laser cutting process development. This paper summarizes the development work performed at ORNL on remote fuel disassembly. 2 refs., 1 fig.

  14. Impact of Fission Products Impurity on the Plutonium Content of Metal- and Oxide- Fuels in Sodium Cooled Fast Reactors

    SciTech Connect

    Hikaru Hiruta; Gilles Youinou

    2013-09-01

    This short report presents the neutronic analysis to evaluate the impact of fission product impurity on the Pu content of Sodium-cooled Fast Reactor (SFR) metal- and oxide- fuel fabrication. The similar work has been previously done for PWR MOX fuel [1]. The analysis will be performed based on the assumption that the separation of the fission products (FP) during the reprocessing of UOX spent nuclear fuel assemblies is not perfect and that, consequently, a certain amount of FP goes into the Pu stream used to fabricate SFR fuels. Only non-gaseous FPs have been considered (see the list of 176 isotopes considered in the calculations in Appendix 1 of Reference 1). Throughout of this report, we define the mixture of Pu and FPs as PuFP. The main objective of this analysis is to quantify the increase of the Pu content of SFR fuels necessary to maintain the same average burnup at discharge independently of the amount of FP in the Pu stream, i.e. independently of the PuFP composition. The FP losses are considered element-independent, i.e., for example, 1% of FP losses mean that 1% of all non-gaseous FP leak into the Pu stream.

  15. Engineering interface and surface of noble metal nanoparticle nanotubes toward enhanced catalytic activity for fuel cell applications.

    PubMed

    Cui, Chun-Hua; Yu, Shu-Hong

    2013-07-16

    In order for fuel cells to have commercial viability as alternative fuel sources, researchers need to develop highly active and robust fuel cell electrocatalysts. In recent years, the focus has been on the design and synthesis of novel catalytic materials with controlled interface and surface structures. Another goal is to uncover potential catalytic activity and selectivity, as well as understand their fundamental catalytic mechanisms. Scientists have achieved great progress in the experimental and theoretical investigation due to the urgent demand for broad commercialization of fuel cells in automotive applications. However, there are still three main problems: cost, performance, and stability. To meet these targets, the catalyst needs to have multisynergic functions. In addition, the composition and structure changes of the catalysts during the reactions still need to be explored. Activity in catalytic nanomaterials is generally controlled by the size, shape, composition, and interface and surface engineering. As such, one-dimensional nanostructures such as nanowires and nanotubes are of special interest. However, these structures tend to lose the nanoparticle morphology and inhibit the use of catalysts in both fuel cell anodes and cathodes. In 2003, Rubinstein and co-workers proposed the idea of nanoparticle nanotubes (NNs), which combine the geometry of nanotubes and the morphology of nanoparticles. This concept gives both the high surface-to-volume ratio and the size effect, which are both appealing in electrocatalyst design. In this Account, we describe our developments in the construction of highly active NNs with unique surface and heterogeneous interface structures. We try to clarify enhanced activity and stability in catalytic systems by taking into account the activity impact factors. We briefly introduce material structural effects on the electrocatalytic reactivity including metal oxide/metal and metal/metal interfaces, dealloyed pure Pt, and mixed Pt

  16. High-temperature compatibility between liquid metal as PWR fuel gap filler and stainless steel and high-density concrete

    NASA Astrophysics Data System (ADS)

    Wongsawaeng, Doonyapong; Jumpee, Chayanit; Jitpukdee, Manit

    2014-08-01

    In conventional nuclear fuel rods for light-water reactors, a helium-filled as-fabricated gap between the fuel and the cladding inner surface accommodates fuel swelling and cladding creep down. Because helium exhibits a very low thermal conductivity, it results in a large temperature rise in the gap. Liquid metal (LM; 1/3 weight portion each of lead, tin, and bismuth) has been proposed to be a gap filler because of its high thermal conductivity (∼100 times that of He), low melting point (∼100 °C), and lack of chemical reactivity with UO2 and water. With the presence of LM, the temperature drop across the gap is virtually eliminated and the fuel is operated at a lower temperature at the same power output, resulting in safer fuel, delayed fission gas release and prevention of massive secondary hydriding. During normal reactor operation, should an LM-bonded fuel rod failure occurs resulting in a discharge of liquid metal into the bottom of the reactor pressure vessel, it should not corrode stainless steel. An experiment was conducted to confirm that at 315 °C, LM in contact with 304 stainless steel in the PWR water chemistry environment for up to 30 days resulted in no observable corrosion. Moreover, during a hypothetical core-melt accident assuming that the liquid metal with elevated temperature between 1000 and 1600 °C is spread on a high-density concrete basement of the power plant, a small-scale experiment was performed to demonstrate that the LM-concrete interaction at 1000 °C for as long as 12 h resulted in no penetration. At 1200 °C for 5 h, the LM penetrated a distance of ∼1.3 cm, but the penetration appeared to stop. At 1400 °C the penetration rate was ∼0.7 cm/h. At 1600 °C, the penetration rate was ∼17 cm/h. No corrosion based on chemical reactions with high-density concrete occurred, and, hence, the only physical interaction between high-temperature LM and high-density concrete was from tiny cracks generated from thermal stress. Moreover

  17. Numerical evaluation of oxide growth in metallic support microstructures of Solid Oxide Fuel Cells and its influence on mass transport

    NASA Astrophysics Data System (ADS)

    Reiss, Georg; Frandsen, Henrik Lund; Persson, Åsa Helen; Weiß, Christian; Brandstätter, Wilhelm

    2015-11-01

    Metal-supported Solid Oxide Fuel Cells (SOFCs) are developed as a durable and cost-effective alternative to the state-of-the-art cermet SOFCs. This novel technology offers new opportunities but also new challenges. One of them is corrosion of the metallic support, which will decrease the long-term performance of the SOFCs. In order to understand the implications of the corrosion on the mass-transport through the metallic support, a corrosion model is developed that is capable of determining the change of the porous microstructure due to oxide scale growth. The model is based on high-temperature corrosion theory, and the required model parameters can be retrieved by standard corrosion weight gain measurements. The microstructure is reconstructed from X-ray computed tomography, and converted into a computational grid. The influence of the changing microstructure on the fuel cell performance is evaluated by determining an effective diffusion coefficient and the equivalent electrical area specific resistance (ASR) due to diffusion over time. It is thus possible to assess the applicability (in terms of corrosion behaviour) of potential metallic supports without costly long-term experiments. In addition to that an analytical frame-work is proposed, which is capable of estimating the porosity, tortuosity and the corresponding ASR based on weight gain measurements.

  18. The application of electrorefining for recovery and purification of fuel discharged from the Integral Fast Reactor

    SciTech Connect

    Burris, L.; Steunenberg, R.K.; Miller, W.E.

    1986-01-01

    An electrorefining process employing a molten salt electrolyte and a molten cadmium anode is proposed for the separation of uranium and plutonium from fission products and cladding material in discharged IFR driver fuel. The use of a liquid cadmium anode, which is the unique feature of the process, permits selective dissolution of the fuel from the cladding and prevents electrolytic corrosion of the steel container and contamination of the product by noble metal fission products.

  19. Development of Mixed Ion-Electron Conducting Metal Oxides for Solid Oxide Fuel Cells

    NASA Astrophysics Data System (ADS)

    Kan, Wang Hay

    A solid oxide fuel cell (SOFC) is an energy conversion device, which directly converts chemical fuels (e.g., H2, C xHy) into electricity and heat with high efficiency up to 90%. The by-product of CO2 can be safely sequestrated or subsequently chemically transformed back into fuels (e.g., CO, CH 4) by electrolysis using renewable energy sources such as solar and wind. The state-of-the-art Ni-YSZ anode is de-activated in the presence of ppm level of H2S and forming coke in hydrocarbons. Currently, mixed ion and electron conductors (MIECs) are considered as alternatives for Ni-YSZ in SOFCs. The key goal of the research was to develop mixed ion-electron conducting metal oxides based on B-site disordered perovskite-type Ba(Ca,Nb)1-x MxO3-delta (M = Mn, Fe, Co), the B-site 1:1 ordered perovskite-type (M = Mn, Fe, Co) and the Sr2PbO4-type Sr2Ce1-xPrxO4 for SOFCs. Ba2(Ca,Nb)2-xMxO6-delta was chemically stable in 30 ppm levels of H2S at 600 °C for 24 h and in pure CO2 at 800 °C for 24 h. The thermal expansion coefficients (TEC) of the as-prepared ordered perovskites was found to be comparable to Zr0.84Y0.16O1.92 (YSZ). The near-surface concentration of Fe2+ in Ba2Ca 0.67Fe0.33NbO6-delta was found to be about 3 times higher than that in the bulk sample. The electrochemical performance of Ba2Ca0.67M0.33NbO6-delta was assessed by ac impedance spectroscopy using a YSZ supported half-cell. The area specific polarization resistance (ASR) of all samples was found to decrease with increasing temperature. The ASR for H2 gas oxidation can be correlated to the higher concentration of low valence Fe2+ species near-surface (nano-scale). BaCa0.335M0.165Nb0.5O3-delta crystallizes in the B-site disordered primitive perovskite (space group Pm-3m) at 900 °C in air, which can be converted into the B-site 1:2 ordered perovskite (space group P-3m1) at 1200 °C and the B-site 1:1 ordered double perovskite phase (space group Fm-3m ) at 1300 °C. The chemical stability of the perovskites in CO

  20. Visible light active, nano-architectured metal oxide photo-catalysts for solar fuel applications

    NASA Astrophysics Data System (ADS)

    LaTempa, Thomas Joseph, Jr.

    Large-scale implementation of renewable energy sources such as solar requires the development of an efficient energy capture, conversion and storage scheme. Harnessing solar energy to create storable fuels, i.e., solar fuels, provides a unique strategy to meet this objective. In this regard, hydrogen generation through water photoelectrolysis and methane generation via the photocatalytic conversion of carbon dioxide and water vapor are investigated. The primary motivation of this work lies in the development of efficient, low cost materials for solar fuel applications. Metal oxide semiconductors such as n-type titanium dioxide (TiO 2) have generated significant interest in the scientific community due to their low cost, stability and high photocatalytic activity under band gap illumination. The implementation of nano-structured materials has significantly enhanced the conversion efficiency obtained with TiO2 in applications such as water photoelectrolysis. Despite these advancements, TiO2 has an inherently poor photoresponse due its wide band gap (3.0-3.2 eV), which accounts for ≈ 5% of the solar spectrum energy. Therefore, the primary objective of this work is to develop materials with a photocatalytic activity approaching that of TiO2, while shifting the photo-response to harness the visible light portion of the solar spectrum. Two differing approaches are evaluated in this work to meet this objective. Hematite (alpha-Fe2O3) has a band gap ≈ 2.2 eV, well suited for capturing solar energy, but suffers from intrinsically poor electrical characteristics. To overcome these limitations, iron oxide nanotubes were developed using a temperature controlled anodization technique. This provides greater control over the film morphology to create high aspect ratio nano-structures approximately 1-4 mum in length, sufficient to harness solar energy, with a wall thickness approaching 10 nm to improve the electrical characteristics for photocatalytic application. The

  1. Diffusion Barrier Selection from Refractory Metals (Zr, Mo and Nb) via Interdiffusion Investigation for U-Mo RERTR Fuel Alloy

    SciTech Connect

    K. Huang; C. Kammerer; D. D. Keiser, Jr.; Y. H. Sohn

    2014-04-01

    U-Mo alloys are being developed as low enrichment monolithic fuel under the Reduced Enrichment for Research and Test Reactor (RERTR) Program. Diffusional interactions between the U-Mo fuel alloy and Al-alloy cladding within the monolithic fuel plate construct necessitate incorporation of a barrier layer. Fundamentally, a diffusion barrier candidate must have good thermal conductivity, high melting point, minimal metallurgical interaction, and good irradiation performance. Refractory metals, Zr, Mo, and Nb are considered based on their physical properties, and the diffusion behavior must be carefully examined first with U-Mo fuel alloy. Solid-to-solid U-10wt.%Mo vs. Mo, Zr, or Nb diffusion couples were assembled and annealed at 600, 700, 800, 900 and 1000 degrees C for various times. The interdiffusion microstructures and chemical composition were examined via scanning electron microscopy and electron probe microanalysis, respectively. For all three systems, the growth rate of interdiffusion zone were calculated at 1000, 900 and 800 degrees C under the assumption of parabolic growth, and calculated for lower temperature of 700, 600 and 500 degrees C according to Arrhenius relationship. The growth rate was determined to be about 10 3 times slower for Zr, 10 5 times slower for Mo and 10 6 times slower for Nb, than the growth rates reported for the interaction between the U-Mo fuel alloy and pure Al or Al-Si cladding alloys. Zr, however was selected as the barrier metal due to a concern for thermo- mechanical behavior of UMo/Nb interface observed from diffusion couples, and for ductile-to-brittle transition of Mo near room temperature.

  2. N- and S-doped mesoporous carbon as metal-free cathode catalysts for direct biorenewable alcohol fuel cells

    SciTech Connect

    Qiu, Yang; Huo, Jiajie; Jia, Fan; Shanks, Brent. H.; Li, Wenzhen

    2015-11-06

    Nitrogen and sulfur were simultaneously doped into the framework of mesoporous CMK-3 as metal-free catalysts for direct biorenewable alcohol fuel cells. Glucose, NH3, and thiophene were used as carbon, nitrogen and sulfur precursors, respectively, to prepare mesoporous N-S-CMK-3 with uniform mesopores and extra macropores, resulting in good O2 diffusion both in half cell and alcohol fuel cell investigations. Among all investigated CMK-3 based catalysts, N-S-CMK-3 prepared at 800 °C exhibited the highest ORR activity with the onset potential of 0.92 V vs. RHE, Tafel slope of 68 mV dec-1, and 3.96 electron transfer number per oxygen molecule in 0.1 M KOH. In addition, the alkaline membrane-based direct alcohol fuel cell (DAFC) with N-S-CMK-3 cathode displayed 88.2 mW cm-2 peak power density without obvious O2 diffusion issue, reaching 84% initial performance of that with a Pt/C cathode. The high catalyst durability and fuel-crossover tolerance led to stable performance of the N-S-CMK-3 cathode DAFC with 90.6 mW cm-2 peak power density after 2 h operation, while the Pt/C cathode-based DAFC lost 36.9% of its peak power density. In conclusion, the high ORR activity of N-S-CMK-3 can be attributed to the synergistic effect between graphitic-N and S (C–S–C structure), suggesting great potential to use N-S-CMK-3 as an alternative to noble metal catalysts in the fuel cell cathode.

  3. N- and S-doped mesoporous carbon as metal-free cathode catalysts for direct biorenewable alcohol fuel cells

    DOE PAGES

    Qiu, Yang; Huo, Jiajie; Jia, Fan; ...

    2015-11-06

    Nitrogen and sulfur were simultaneously doped into the framework of mesoporous CMK-3 as metal-free catalysts for direct biorenewable alcohol fuel cells. Glucose, NH3, and thiophene were used as carbon, nitrogen and sulfur precursors, respectively, to prepare mesoporous N-S-CMK-3 with uniform mesopores and extra macropores, resulting in good O2 diffusion both in half cell and alcohol fuel cell investigations. Among all investigated CMK-3 based catalysts, N-S-CMK-3 prepared at 800 °C exhibited the highest ORR activity with the onset potential of 0.92 V vs. RHE, Tafel slope of 68 mV dec-1, and 3.96 electron transfer number per oxygen molecule in 0.1 Mmore » KOH. In addition, the alkaline membrane-based direct alcohol fuel cell (DAFC) with N-S-CMK-3 cathode displayed 88.2 mW cm-2 peak power density without obvious O2 diffusion issue, reaching 84% initial performance of that with a Pt/C cathode. The high catalyst durability and fuel-crossover tolerance led to stable performance of the N-S-CMK-3 cathode DAFC with 90.6 mW cm-2 peak power density after 2 h operation, while the Pt/C cathode-based DAFC lost 36.9% of its peak power density. In conclusion, the high ORR activity of N-S-CMK-3 can be attributed to the synergistic effect between graphitic-N and S (C–S–C structure), suggesting great potential to use N-S-CMK-3 as an alternative to noble metal catalysts in the fuel cell cathode.« less

  4. A methodology for investigating new nonprecious metal catalysts for PEM fuel cells.

    PubMed

    Susac, D; Sode, A; Zhu, L; Wong, P C; Teo, M; Bizzotto, D; Mitchell, K A R; Parsons, R R; Campbell, S A

    2006-06-08

    This paper reports an approach to investigate metal-chalcogen materials as catalysts for the oxygen reduction reaction (ORR) in proton exchange membrane (PEM) fuel cells. The methodology is illustrated with reference to Co-Se thin films prepared by magnetron sputtering onto a glassy-carbon substrate. Scanning Auger microscopy (SAM), X-ray photoelectron spectroscopy (XPS), energy-dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD) have been used, in parallel with electrochemical activity and stability measurements, to assess how the electrochemical performance relates to chemical composition. It is shown that Co-Se thin films with varying Se are active for oxygen reduction, although the open circuit potential (OCP) is lower than for Pt. A kinetically controlled process is observed in the potential range 0.5-0.7 V (vs reversible hydrogen electrode) for the thin-film catalysts studied. An initial exposure of the thin-film samples to an acid environment served as a pretreatment, which modified surface composition prior to activity measurements with the rotating disk electrode (RDE) method. Based on the SAM characterization before and after electrochemical tests, all surfaces demonstrating activity are dominated by chalcogen. XRD shows that the thin films have nanocrystalline character that is based on a Co(1-x)Se phase. Parallel studies on Co-Se powder supported on XC72R carbon show comparable OCP, Tafel region, and structural phase as for the thin-film model catalysts. A comparison for ORR activity has also been made between this Co-Se powder and a commercial Pt catalyst.

  5. Driver Aid and Education Test Project. Final Report.

    ERIC Educational Resources Information Center

    Shadis, W.; Soucek, S. J.

    A driver education project tested the hypothesis that measurable improvements in fleet fuel economy can be achieved by driver awareness training in fuel-efficient driving techniques and by a manifold vacuum gauge, used individually or in combination with each other. From April 1976 through December 1977 data were collected in the Las Vegas,…

  6. Cladding inner surface wastage for mixed-oxide liquid metal reactor fuel pins

    SciTech Connect

    Lawrence, L.A.; Bard, F.E.; Cannon, N.S.

    1990-11-01

    Cladding inner surface wastage was measured on reference fuel pins with stainless steel and D9 cladding irradiated beyond goal burnup in the Fast Flux Test Facility. Measurements were compared to the Experimental Breeder Reactor No. 2 based fuel-cladding chemical interaction correlation developed for uranium-plutonium oxide fuels with 20% cold-worked stainless steel cladding. The fuel-cladding chemical interaction was also measured in fuel pins irradiated with HT9 cladding. Comparison of the measurements with the design correlation showed the correlation adequately accounted for the extent of interaction in the Fast Flux Test Facility fuel pins with cold-worked stainless steel D9, and HT9 cladding. 9 refs., 6 figs.

  7. Nuclear reactor composite fuel assembly

    DOEpatents

    Burgess, Donn M.; Marr, Duane R.; Cappiello, Michael W.; Omberg, Ronald P.

    1980-01-01

    A core and composite fuel assembly for a liquid-cooled breeder nuclear reactor including a plurality of elongated coextending driver and breeder fuel elements arranged to form a generally polygonal bundle within a thin-walled duct. The breeder elements are larger in cross section than the driver elements, and each breeder element is laterally bounded by a number of the driver elements. Each driver element further includes structure for spacing the driver elements from adjacent fuel elements and, where adjacent, the thin-walled duct. A core made up of the fuel elements can advantageously include fissile fuel of only one enrichment, while varying the effective enrichment of any given assembly or core region, merely by varying the relative number and size of the driver and breeder elements.

  8. Electron probe microanalysis of a METAPHIX UPuZr metallic alloy fuel irradiated to 7.0 at.% burn-up

    NASA Astrophysics Data System (ADS)

    Brémier, S.; Inagaki, K.; Capriotti, L.; Poeml, P.; Ogata, T.; Ohta, H.; Rondinella, V. V.

    2016-11-01

    The METAPHIX project is a collaboration between CRIEPI and JRC-ITU investigating safety and performance of a closed fuel cycle option based on fast reactor metal alloy fuels containing Minor Actinides (MA). The aim of the project is to investigate the behaviour of this type of fuel and demonstrate the transmutation of MA under irradiation. A UPuZr metallic fuel sample irradiated to a burn-up of 7 at.% was examined by electron probe microanalysis. The fuel sample was extensively characterised qualitatively and quantitatively using elemental X-ray imaging and point analysis techniques. The analyses reveal a significant redistribution of the fuel components along the fuel radius highlighting a nearly complete depletion of Zr in the central part of the fuel. Numerous rare earth and fission products secondary phases are present in various compositions. Fuel cladding chemical interaction was observed with creation of a number of intermediary layers affecting a cladding depth of 15-20 μm and migration of cladding elements to the fuel.

  9. In-pile release behavior of metallic fission products in graphite materials of an htgr fuel assembly

    NASA Astrophysics Data System (ADS)

    Hayashi, K.; Kobayashi, F.; Minato, K.; Ikawa, K.; Fukuda, K.

    1987-06-01

    Distribution of metallic fission products in the graphite sleeve and block of the fifth OGL-1 fuel assembly was measured by gamma spectrometry with lathe sectioning. Considerably large release fractions of long-lived fission products with smooth axial profiles were observed in the sleeve due to a large failure fraction of coated fuel particles accompanied with failed silicon carbide layers. Nevertheless, a key nuclide 110mAg, whose large release is suspected at increased burnups for low-enriched uranium fuels, was effectively retained within the graphite sleeve. The retention was also observed for 125Sb, 154Eu and 155Eu up to a burnup of 3.2% fission per initial metal atom, but was limited for 134Cs and 137Cs at high sleeve-temperatures above 900°C. In-pile diffusion coefficients in IG-110 graphite have been evaluated for Cs, Ag and Sb; those for Cs are in reasonable agreement with available in-pile data.

  10. Compatibility Study for Plastic, Elastomeric, and Metallic Fueling Infrastructure Materials Exposed to Aggressive Formulations of Ethanol-blended Gasoline

    SciTech Connect

    Kass, Michael D; Pawel, Steven J; Theiss, Timothy J; Janke, Christopher James

    2012-07-01

    In 2008 Oak Ridge National Laboratory began a series of experiments to evaluate the compatibility of fueling infrastructure materials with intermediate levels of ethanol-blended gasoline. Initially, the focus was elastomers, metals, and sealants, and the test fuels were Fuel C, CE10a, CE17a and CE25a. The results of these studies were published in 2010. Follow-on studies were performed with an emphasis on plastic (thermoplastic and thermoset) materials used in underground storage and dispenser systems. These materials were exposed to test fuels of Fuel C and CE25a. Upon completion of this effort, it was felt that additional compatibility data with higher ethanol blends was needed and another round of experimentation was performed on elastomers, metals, and plastics with CE50a and CE85a test fuels. Compatibility of polymers typically relates to the solubility of the solid polymer with a solvent. It can also mean susceptibility to chemical attack, but the polymers and test fuels evaluated in this study are not considered to be chemically reactive with each other. Solubility in polymers is typically assessed by measuring the volume swell of the polymer exposed to the solvent of interest. Elastomers are a class of polymers that are predominantly used as seals, and most o-ring and seal manufacturers provide compatibility tables of their products with various solvents including ethanol, toluene, and isooctane, which are components of aggressive oxygenated gasoline as described by the Society of Automotive Engineers (SAE) J1681. These tables include a ranking based on the level of volume swell in the elastomer associated with exposure to a particular solvent. Swell is usually accompanied by a decrease in hardness (softening) that also affects performance. For seal applications, shrinkage of the elastomer upon drying is also a critical parameter since a contraction of volume can conceivably enable leakage to occur. Shrinkage is also indicative of the removal of one or more

  11. Long-term clinical and economic analysis of the Endeavor drug-eluting stent versus the Driver bare-metal stent: 4-year results from the ENDEAVOR II trial (Randomized Controlled Trial to Evaluate the Safety and Efficacy of the Medtronic AVE ABT-578 Eluting Driver Coronary Stent in De Novo Native Coronary Artery Lesions).

    PubMed

    Eisenstein, Eric L; Wijns, William; Fajadet, Jean; Mauri, Laura; Edwards, Rex; Cowper, Patricia A; Kong, David F; Anstrom, Kevin J

    2009-12-01

    This study was designed to evaluate long-term clinical and economic outcomes for subjects receiving Endeavor drug-eluting versus Driver bare-metal stents (both Medtronic CardioVascular, Santa Rosa, California). Early studies found that the drug-eluting stent (DES) was a clinically and economically attractive alternative to the bare-metal stent; however, associations between DES and very late stent thrombosis suggest that longer follow-up is required. We used clinical, resource use and follow-up data from 1,197 subjects randomized to receive Endeavor (n = 598) versus Driver (n = 599) stents in ENDEAVOR II (Randomized Controlled Trial to Evaluate the Safety and Efficacy of the Medtronic AVE ABT-578 Eluting Driver Coronary Stent in De Novo Native Coronary Artery Lesions) study with Medicare cost weights and quality of life adjustments applied from secondary sources. We compared differences through 4-year follow-up (1,440 days). Patients in both treatment groups had similar baseline characteristics. The use of Endeavor versus Driver reduced 4-year target vessel revascularization rates per 100 subjects (10.4 vs. 21.5; difference: -11.1; 95% confidence interval [CI]: -16.0 to -6.1; p < 0.001), with no difference in the rates per 100 subjects of death (5.0 vs. 5.2; difference: -0.2; 95% CI: -2.7 to 2.4; p = 0.90) or nonfatal myocardial infarction (3.2 vs. 4.4; difference: -1.2; 95% CI: -3.4 to 1.0; p = 0.29). After discounting at a 3% annual rate, there were no differences in quality-adjusted survival days (1,093 vs. 1,090; difference: 3; 95% CI: -13 to 19; p = 0.69) and total medical costs ($21,483 vs. $21,680; difference: -$198; 95% CI: -$1,608 to $1,207; p = 0.78). The use of Endeavor versus Driver was associated with a significant reduction in target vessel revascularization through 4-year follow-up with no difference in death, nonfatal myocardial infarction, quality-adjusted survival, or total medical costs. These results are comparable to those for other studies

  12. Evaluation of Metal Halide, Plasma, and LED Lighting Technologies for a Hydrogen Fuel Cell Mobile Light (H 2 LT)

    SciTech Connect

    Miller, L. B.; Donohoe, S. P.; Jones, M. H.; White, W. A.; Klebanoff, L. E.; Velinsky, S. A.

    2015-04-22

    This article reports on the testing and comparison of a prototype hydrogen fuel cell light tower (H2LT) and a conventional diesel-powered metal halide light trailer for use in road maintenance and construction activities. The prototype was originally outfitted with plasma lights and then with light-emitting diode (LED) luminaires. Light output and distribution, lighting energy efficiency (i.e., efficacy), power source thermal efficiency, and fuel costs are compared. The metal halide luminaires have 2.2 and 3.1 times more light output than the plasma and LED luminaires, respectively, but they require more power/lumen to provide that output. The LED luminaires have 1.6 times better light efficacy than either the metal halide or plasma luminaires. The light uniformity ratios produced by the plasma and LED towers are acceptable. The fuel cell thermal efficiency at the power required to operate the plasma lights is 48%, significantly higher than the diesel generator efficiency of 23% when operating the metal halide lights. Due to the increased efficiency of the fuel cell and the LED lighting, the fuel cost per lumen-hour of the H2LT is 62% of the metal halide diesel light tower assuming a kilogram of hydrogen is twice the cost of a gallon of diesel fuel.

  13. LAND 121 Lightweight Vehicle Driver Conversion Course Study Using A-SMART

    DTIC Science & Technology

    2012-02-01

    Directed Training Requirement ECN Employment Category Number FY Financial Year GS General Service HC Heavy Combination HR Heavy Rigid ...Course and IET Driver RACT Course plus six months TIR;  Private (109-1) Two courses from: o Driver – Heavy Rigid GS (HR2), o Driver – Heavy Rigid CL...D), o Operator Bulk Fuel Tanker, o Driver – (Coach) Heavy Rigid (HR3), o Operate a Vehicle Mounted Crane, o Driver Bus (MR3), o Driver Forklift

  14. Anodic process of electrorefining spent nuclear fuel in molten LiCl-KCL-UCl{sub 3}/CD system.

    SciTech Connect

    Li, S. X.

    2002-07-03

    This article summarizes the experimental results and engineering aspects regarding the anodic process for electrorefining 100 irradiated driver fuel assemblies, a demonstration project for the Department of Energy (DOE) to treat spent nuclear fuel. The focus is on the anode due to its unique geometry (fuel dissolution baskets loaded with chopped irradiated fuel segments), complex chemical compositions, highly demanding process goals and their significance to the entire spent fuel treatment process. Chemical analysis results of cladding hull samples were used as the key criteria to evaluate the effectiveness of the uranium dissolution and noble metal retention. Parametric study indicated that the diffusion of reactants in the porous fuel matrix was the rate-controlling step to the uranium dissolution from the chopped fuel segments. Anode resistance was the most effective parameter to assess the completeness of uranium dissolution and noble metal retention.

  15. Metal organic chemical vapor deposition of environmental barrier coatings for the inhibition of solid deposit formation from heated jet fuel

    NASA Astrophysics Data System (ADS)

    Mohan, Arun Ram

    Solid deposit formation from jet fuel compromises the fuel handling system of an aviation turbine engine and increases the maintenance downtime of an aircraft. The deposit formation process depends upon the composition of the fuel, the nature of metal surfaces that come in contact with the heated fuel and the operating conditions of the engine. The objective of the study is to investigate the effect of substrate surfaces on the amount and nature of solid deposits in the intermediate regime where both autoxidation and pyrolysis play an important role in deposit formation. A particular focus has been directed to examining the effectiveness of barrier coatings produced by metal organic chemical vapor deposition (MOCVD) on metal surfaces for inhibiting the solid deposit formation from jet fuel degradation. In the first part of the experimental study, a commercial Jet-A sample was stressed in a flow reactor on seven different metal surfaces: AISI316, AISI 321, AISI 304, AISI 347, Inconel 600, Inconel 718, Inconel 750X and FecrAlloy. Examination of deposits by thermal and microscopic analysis shows that the solid deposit formation is influenced by the interaction of organosulfur compounds and autoxidation products with the metal surfaces. The nature of metal sulfides was predicted by Fe-Ni-S ternary phase diagram. Thermal stressing on uncoated surfaces produced coke deposits with varying degree of structural order. They are hydrogen-rich and structurally disordered deposits, spherulitic deposits, small carbon particles with relatively ordered structures and large platelets of ordered carbon structures formed by metal catalysis. In the second part of the study, environmental barrier coatings were deposited on tube surfaces to inhibit solid deposit formation from the heated fuel. A new CVD system was configured by the proper choice of components for mass flow, pressure and temperature control in the reactor. A bubbler was designed to deliver the precursor into the reactor

  16. Effects of heavy metals (Fe3+/Cr6+) on low-level energy generation in a microbial fuel cell

    NASA Astrophysics Data System (ADS)

    Caparanga, A. R.; Balatbat, A. S.; Tayo, L.

    2017-06-01

    A dual-chamber microbial fuel cell (MFC) was constructed with Pseudomonas aeruginosa as biocatalyst to facilitate substrate conversion and, consequently, low-level energy generation. To simulate a wastewater situation with BOD and heavy metals contamination, glucose and Fe3+ and Cr6+ were used as substrate and heavy-metal spikes, respectively. The effects of varying substrate concentrations (150 ppm, 300 ppm, 600 ppm) and heavy metal loads (10 ppm, 50 ppm, 100 ppm) on overall power generation were evaluated. The presence of Cr6+ in the anode compartment decreased the potential from 565 to 201 mV (i.e., lowest value achieved at highest Cr6+ concentration of 300 ppm). On the other hand, replacing Cr6+ with Fe3+ as electron acceptor resulted in substantial increase in measured potential (i.e., from 565 to 703 mV). Increasing glucose concentrations resulted in longer time to reach constant open circuit voltage. A maximum potential of 606 mV was achieved at 1200 ppm glucose. Incorporating Pseudomonas aeruginosa increased the potential from 256 to 592 mV. On the basis of these results, a microbial fuel cell feeding on wastewater can be an important potential technology for generating low-level energy

  17. Efficient solar-driven synthesis, carbon capture, and desalinization, STEP: solar thermal electrochemical production of fuels, metals, bleach.

    PubMed

    Licht, S

    2011-12-15

    STEP (solar thermal electrochemical production) theory is derived and experimentally verified for the electrosynthesis of energetic molecules at solar energy efficiency greater than any photovoltaic conversion efficiency. In STEP the efficient formation of metals, fuels, chlorine, and carbon capture is driven by solar thermal heated endothermic electrolyses of concentrated reactants occuring at a voltage below that of the room temperature energy stored in the products. One example is CO(2) , which is reduced to either fuels or storable carbon at a solar efficiency of over 50% due to a synergy of efficient solar thermal absorption and electrochemical conversion at high temperature and reactant concentration. CO(2) -free production of iron by STEP, from iron ore, occurs via Fe(III) in molten carbonate. Water is efficiently split to hydrogen by molten hydroxide electrolysis, and chlorine, sodium, and magnesium from molten chlorides. A pathway is provided for the STEP decrease of atmospheric carbon dioxide levels to pre-industial age levels in 10 years.

  18. Contributions to economic geology (short papers and preliminary reports), 1927: Part I - Metals and nonmetals except fuels

    USGS Publications Warehouse

    Loughlin, Gerald Francis; Mansfield, George Rogers

    1927-01-01

    The Geological Survey's "Contributions to economic geology" are published in two parts, one including papers on metals and nonmetals except fuels and the other including papers on mineral fuels. As the subtitle indicates, most of the papers in these volumes are of three classes (1) short papers describing as thoroughly as conditions will permit areas or deposits on which no other report is likely to be prepared; (2) brief notes on mining districts or economic deposits whose examination has been merely incidental to other work; and (3) preliminary reports on economic investigations the results of which are to be published later in more detailed form. Although these papers set forth mainly the practical results of economic investigations, they include brief theoretical discussions and summary statements of conclusions if these appear to require prompt publication.

  19. Metallic elements in fossil fuel combustion products: amounts and form of emissions and evaluation of carcinogenicity and mutagenicity.

    PubMed Central

    Vouk, V B; Piver, W T

    1983-01-01

    Metallic elements contained in coal, oil and gasoline are mobilized by combustion processes and may be emitted into the atmosphere, mainly as components of submicron particles. The information about the amounts, composition and form of metal compounds is reviewed for some fuels and combustion processes. Since metal compounds are always contained in urban air pollutants, they have to be considered whenever an evaluation of biological impact of air pollutants is made. The value of currently used bioassays for the evaluation of the role of trace metal compounds, either as major biologically active components or as modifiers of biological effects of organic compounds is assessed. The whole animal bioassays for carcinogenicity do not seem to be an appropriate approach. They are costly, time-consuming and not easily amenable to the testing of complex mixtures. Some problems related to the application and interpretation of short-term bioassays are considered, and the usefulness of such bioassays for the evaluation of trace metal components contained in complex air pollution mixtures is examined. PMID:6337825

  20. DEVELOPMENT OF GLASS COMPOSITIONS TO IMMOBILIZE ALKALI, ALKALINE EARTH, LANTHANIDE AND TRANSITION METAL FISSION PRODUCTS FROM NUCLEAR FUEL REPROCESSING

    SciTech Connect

    Marra, J.; Billings, A.

    2009-06-24

    The Advanced Fuel Cycle Initiative (AFCI) waste management strategy revolves around specific treatment of individual or groups of separated waste streams. A goal for the separations processes is to efficiently manage the waste to be dispositioned as high level radioactive waste. The Advanced Fuel Cycle Initiative (AFCI) baseline technology for immobilization of the lanthanide (Ln) and transition metal fission product (TM) wastes is vitrification into a borosilicate glass. A current interest is to evaluate the feasibility of vitrifying combined waste streams to most cost effectively immobilize the wastes resulting from aqueous fuel reprocessing. Studies showed that high waste loadings are achievable for the Ln only (Option 1) stream. Waste loadings in excess of 60 wt % (on a calcined oxide basis) were demonstrated via a lanthanide borosilicate (LaBS) glass. The resulting glasses had excellent relative durability as determined by the Product Consistency Test (PCT). For a combined Ln and TM waste stream glass (Option 2), noble metal solubility was found to limit waste loading. However, the measured PCT normalized elemental releases for this glass were at least an order of magnitude below that of Environmental Assessment (EA) glass. Current efforts to evaluate the feasibility of vitrifying combined Ln, TM, alkali (Cs is the primary radionuclide of concern) and alkaline earth (Sr is the primary radionuclide of concern) wastes (Option 3) have shown that these approaches are feasible. However, waste loading limitations with respect to heat load (Cs/Sr loading), molybdenum solubility and/or noble metal solubility will likely be realized and must be considered in determining the cost effectiveness of these approaches.

  1. Emissions from a Diesel Engine using Fe-based Fuel Additives and a Sintered Metal Filtration System

    PubMed Central

    Bugarski, Aleksandar D.; Hummer, Jon A.; Stachulak, Jozef S.; Miller, Arthur; Patts, Larry D.; Cauda, Emanuele G.

    2015-01-01

    A series of laboratory tests were conducted to assess the effects of Fe-containing fuel additives on aerosols emitted by a diesel engine retrofitted with a sintered metal filter (SMF) system. Emission measurements performed upstream and downstream of the SMF system were compared, for cases when the engine was fueled with neat ultralow sulfur diesel (ULSD) and with ULSD treated with two formulations of additives containing Fe-based catalysts. The effects were assessed for four steady-state engine operating conditions and one transient cycle. The results showed that the SMF system reduced the average total number and surface area concentrations of aerosols by more than 100-fold. The total mass and elemental carbon results confirmed that the SMF system was indeed very effective in the removal of diesel aerosols. When added at the recommended concentrations (30 p.p.m. of iron), the tested additives had minor adverse impacts on the number, surface area, and mass concentrations of filter-out (FOut) aerosols. For one of the test cases, the additives may have contributed to measurable concentrations of engine-out (EOut) nucleation mode aerosols. The additives had only a minor impact on the concentration and size distribution of volatile and semi-volatile FOut aerosols. Metal analysis showed that the introduction of Fe with the additives substantially increased Fe concentration in the EOut, but the SMF system was effective in removal of Fe-containing aerosols. The FOut Fe concentrations for all three tested fuels were found to be much lower than the corresponding EOut Fe concentrations for the case of untreated ULSD fuel. The results support recommendations that these additives should not be used in diesel engines unless they are equipped with exhaust filtration systems. Since the tested SMF system was found to be very efficient in removing Fe introduced by the additives, the use of these additives should not result in a measurable increase in emissions of de novo generated

  2. Emissions from a Diesel Engine using Fe-based Fuel Additives and a Sintered Metal Filtration System.

    PubMed

    Bugarski, Aleksandar D; Hummer, Jon A; Stachulak, Jozef S; Miller, Arthur; Patts, Larry D; Cauda, Emanuele G

    2016-03-01

    A series of laboratory tests were conducted to assess the effects of Fe-containing fuel additives on aerosols emitted by a diesel engine retrofitted with a sintered metal filter (SMF) system. Emission measurements performed upstream and downstream of the SMF system were compared, for cases when the engine was fueled with neat ultralow sulfur diesel (ULSD) and with ULSD treated with two formulations of additives containing Fe-based catalysts. The effects were assessed for four steady-state engine operating conditions and one transient cycle. The results showed that the SMF system reduced the average total number and surface area concentrations of aerosols by more than 100-fold. The total mass and elemental carbon results confirmed that the SMF system was indeed very effective in the removal of diesel aerosols. When added at the recommended concentrations (30 p.p.m. of iron), the tested additives had minor adverse impacts on the number, surface area, and mass concentrations of filter-out (FOut) aerosols. For one of the test cases, the additives may have contributed to measurable concentrations of engine-out (EOut) nucleation mode aerosols. The additives had only a minor impact on the concentration and size distribution of volatile and semi-volatile FOut aerosols. Metal analysis showed that the introduction of Fe with the additives substantially increased Fe concentration in the EOut, but the SMF system was effective in removal of Fe-containing aerosols. The FOut Fe concentrations for all three tested fuels were found to be much lower than the corresponding EOut Fe concentrations for the case of untreated ULSD fuel. The results support recommendations that these additives should not be used in diesel engines unless they are equipped with exhaust filtration systems. Since the tested SMF system was found to be very efficient in removing Fe introduced by the additives, the use of these additives should not result in a measurable increase in emissions of de novo generated

  3. Separation of toxic metal ions, hydrophilic hydrocarbons, hydrophobic fuel and halogenated hydrocarbons and recovery of ethanol from a process stream

    DOEpatents

    Kansa, Edward J.; Anderson, Brian L.; Wijesinghe, Ananda M.; Viani, Brian E.

    1999-01-01

    This invention provides a process to tremendously reduce the bulk volume of contaminants obtained from an effluent stream produced subsurface remediation. The chemicals used for the subsurface remediation are reclaimed for recycling to the remediation process. Additional reductions in contaminant bulk volume are achieved by the ultra-violet light destruction of halogenated hydrocarbons, and the complete oxidation of hydrophobic fuel hydrocarbons and hydrophilic hydrocarbons. The contaminated bulk volume will arise primarily from the disposal of the toxic metal ions. The entire process is modular, so if there are any technological breakthroughs in one or more of the component process modules, such modules can be readily replaced.

  4. Separation of toxic metal ions, hydrophilic hydrocarbons, hydrophobic fuel and halogenated hydrocarbons and recovery of ethanol from a process stream

    DOEpatents

    Kansa, E.J.; Anderson, B.L.; Wijesinghe, A.M.; Viani, B.E.

    1999-05-25

    This invention provides a process to tremendously reduce the bulk volume of contaminants obtained from an effluent stream produced subsurface remediation. The chemicals used for the subsurface remediation are reclaimed for recycling to the remediation process. Additional reductions in contaminant bulk volume are achieved by the ultra-violet light destruction of halogenated hydrocarbons, and the complete oxidation of hydrophobic fuel hydrocarbons and hydrophilic hydrocarbons. The contaminated bulk volume will arise primarily from the disposal of the toxic metal ions. The entire process is modular, so if there are any technological breakthroughs in one or more of the component process modules, such modules can be readily replaced. 3 figs.

  5. Heat-resistant, electrically conducting joint between ceramic end plates and metallic conductors in solid oxide fuel cell

    SciTech Connect

    Wilkenhoener, R.; Buchkremer, H.P.; Stoever, D.; Stolten, D.; Koch, A.

    2000-07-01

    Ceramic parts made of doped lanthanum chromite are used as interconnects and end plates in stacks for several solid oxide fuel cell (SOFC) designs. Metallic conductors have to be attached to enable a low-resistance connection between individual stacks in each SOFC unit and to permit power to be drawn from the SOFC. The resistances of the metal-ceramic bond and the metallic conductors have to be stable under operating conditions, i.e., 1,000 C in air. Consequently, heat-resistant materials have to be used. A two-step process has been developed to connect commercially available, Ni- or Fe-based metallic conductors to ceramic SOFC end plates by vacuum furnace brazing. In the first step, a metallic sheet, which acts as the current collector, is brazed onto the ceramic end plate. Thereby, the much lower electrical conductivity of the ceramic part is compensated by that of the metal. The chromium alloy CrFe5Y{sub 2}O{sub 3}1 is suitable because it is heat-resistant, and its thermal expansion coefficient is close to that of lanthanum chromite. In the second step, metallic wires or strips are brazed on the current collector. Since this joint area is significantly smaller than that of the first joint, materials with a different thermal expansion coefficient can be used, such as conventional heat-resistant nickel alloys (Inconel 617) and ferritic stainless steels (FeCrAl 25 5). Filler alloys for both brazing steps with matching melting points have been found. Hence, both brazing steps can be performed cost-effectively in one heating step. Suitable parameters for vacuum furnace brazing of both joints are presented, and the composition of the filler alloys is given. Data concerning the long-term behavior of the joint resistances in air at 1,000 C are discussed.

  6. 49 CFR 395.11 - Supporting documents for drivers using EOBRs.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 5 2010-10-01 2010-10-01 false Supporting documents for drivers using EOBRs. 395... REGULATIONS HOURS OF SERVICE OF DRIVERS § 395.11 Supporting documents for drivers using EOBRs. (a) Motor... additional supporting documents (e.g., driver payroll records, fuel receipts) that provide the ability...

  7. 49 CFR 395.11 - Supporting documents for drivers using EOBRs.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 5 2011-10-01 2011-10-01 false Supporting documents for drivers using EOBRs. 395... REGULATIONS HOURS OF SERVICE OF DRIVERS § 395.11 Supporting documents for drivers using EOBRs. (a) Motor... additional supporting documents (e.g., driver payroll records, fuel receipts) that provide the ability...

  8. Development of Novel Non-Pt Group Metal Electrocatalysts for PEM Fuel Cell Applications

    SciTech Connect

    Mukerjee, Sanjeev; Atanassov, Plamen; Barton, Scott; Dale, Nilesh; Halevi, Bar

    2016-01-04

    The objective of this multi-institutional effort was to comprehensively pursue the goal of eliminating noble metal (Pt group metals, PGM) from the cathodic oxygen reduction reaction (ORR) electrode thereby providing a quantum leap in lowering the overall PGM loading in a polymer electrolyte fuel cell (PEMFC). The overall project scope encompassed (a) comprehensive materials discovery effort, (b) a concomitant effort to scale up these materials with very high ( ±5%) reproducibility, both intra and inter, (c) understanding mass transport in porous medium both in gas diffusion and micro-porous layers for enhanced areal activity, (d) understanding mechanistic aspects of active site structure and ORR electrocatalytic pathway. Overall project milestones and metrics were (a) first phase effort based on performance in oxygen where the project’s Go/No-Go decision point milestone of 100 mA/cm2 at 0.8 V (internal resistance-free, iR-free) at 80°C, pure H2/O2, with 1.5 bar total pressure was met. Subsequently, the principle objectives were to (a) transition the project from H2/O2 to H2/Air with slated target of exceeding 30 mA/cm2 @ 0.8 V, 2.5 bar total pressure and an end of the project target of 1 A/cm2 @ 0.4 V (same total pressure), both under 100% relative humidity. The target for catalyst material scale up was to achieve 100 g batch size at the end of the program. This scale up target had a quality control milestone of less than 5% variation of activity measured with H2/Air (2.5 bar total pressure) at 0.8 V. In addition, the project also aimed at arriving at a unified understanding of the nature of active sites in these catalysts as well as some preliminary understanding of the mechanistic pathway. Also addressed is the development of an integrated method for determination of mass transport parameters using a combination of Helox experiments and modeling of the gas

  9. Optimization of a microbial fuel cell for wastewater treatment using recycled scrap metals as a cost-effective cathode material.

    PubMed

    Lefebvre, Olivier; Tan, Zi; Shen, Yujia; Ng, How Y

    2013-01-01

    Microbial fuel cell (MFC) for wastewater treatment is still hindered by the prohibitive cost of cathode material, especially when platinum is used to catalyze oxygen reduction. In this study, recycled scrap metals could be used efficiently as cathode material in a specially-designed MFC. In terms of raw power, the scrap metals ranked as follows: W/Co > Cu/Ni > Inconel 718 > carpenter alloy; however, in terms of cost and long term stability, Inconel 718 was the preferred choice. Treatment performance--assessed on real and synthetic wastewater--was considerably improved either by filling the anode compartment with carbon granules or by operating the MFC in full-loop mode. The latter option allowed reaching 99.7% acetate removal while generating a maximum power of 36 W m(-3) at an acetate concentration of 2535 mg L(-1). Under these conditions, the energy produced by the system averaged 0.1 kWh m(-3) of wastewater treated.

  10. An experimental evaluation of metallic diaphragms for positive fuel expulsion in the atmosphere explorer hydrazine propulsion subsystem

    NASA Technical Reports Server (NTRS)

    Woodruff, W. L.

    1973-01-01

    Four Arde conospheroid metallic diaphragms were tested to evaluate their capability for use in the orbit adjust propulsion subsystem (OAPS) of the Explorer spacecraft. The diaphragms will be used for positive propellant expulsion and spacecraft center of mass control. A leak-free cycle life capability of nine reversals was demonstrated. The diaphragms rolled smoothly from ring to ring in a predictable manner on the first reversal. Varying amounts of diaphragm cocking and ring skipping were observed on subsequent reversals. The diaphragm pressure differential did not exceed 7 N/sq cm during any reversal. Cycle life capability, reversal mode, and pressure differential were not affected by sudden reversals, environmental tests, or 18,000 partial reversals. An expulsion efficiency of approximately 97 percent was demonstrated. The results of these tests show that metallic diaphragms can be used as an effective means of positive fuel expulsion; however, to achieve spacecraft center of mass control, the diaphragm must not be reversed prior to flight.

  11. High pressure pyrolyzed non-precious metal oxygen reduction catalysts for alkaline polymer electrolyte membrane fuel cells.

    PubMed

    Sanetuntikul, Jakkid; Shanmugam, Sangaraju

    2015-05-07

    Non-precious metal catalysts, such as metal-coordinated to nitrogen doped-carbon, have shown reasonable oxygen reduction reaction (ORR) performances in alkaline fuel cells. In this report, we present the development of a highly active, stable and low-cost non-precious metal ORR catalyst by direct synthesis under autogenic-pressure conditions. Transmission electron microscopy studies show highly porous Fe-N-C and Co-N-C structures, which were further confirmed by Brunauer-Emmett-Teller surface area measurements. The surface areas of the Fe-N-C and Co-N-C catalysts were found to be 377.5 and 369.3 m(2) g(-1), respectively. XPS results show the possible existence of N-C and M-Nx structures, which are generally proposed to be the active sites in non-precious metal catalysts. The Fe-N-C electrocatalyst exhibits an ORR half-wave potential 20 mV higher than the reference Pt/C catalyst. The cycling durability test for Fe-N-C over 5000 cycles shows that the half-wave potential lost only 4 mV, whereas the half-wave potential of the Pt/C catalyst lost about 50 mV. The Fe-N-C catalyst exhibited an improved activity and stability compared to the reference Pt/C catalyst and it possesses a direct 4-electron transfer pathway for the ORR process. Further, the Fe-N-C catalyst produces extremely low HO2(-) content, as confirmed by the rotating ring-disk electrode measurements. In the alkaline fuel single cell tests, maximum power densities of 75 and 80 mW cm(-2) were observed for the Fe-N-C and Pt/C cathodes, respectively. Durability studies (100 h) showed that decay of the fuel cell current was more prominent for the Pt/C cathode catalyst compared to the Fe-N-C cathode catalyst. Therefore, the Fe-N-C catalyst appears to be a promising new class of non-precious metal catalysts prepared by an autogenic synthetic method.

  12. Self-sustained reduction of multiple metals in a microbial fuel cell-microbial electrolysis cell hybrid system.

    PubMed

    Li, Yan; Wu, Yining; Liu, Bingchuan; Luan, Hongwei; Vadas, Timothy; Guo, Wanqian; Ding, Jie; Li, Baikun

    2015-09-01

    A self-sustained hybrid bioelectrochemical system consisting of microbial fuel cell (MFC) and microbial electrolysis cell (MEC) was developed to reduce multiple metals simultaneously by utilizing different reaction potentials. Three heavy metals representing spontaneous reaction (chromium, Cr) and unspontaneous reaction (lead, Pb and nickel, Ni) were selected in this batch-mode study. The maximum power density of the MFC achieved 189.4 mW m(-2), and the energy recovery relative to the energy storage circuit (ESC) was ∼ 450%. At the initial concentration of 100 mg L(-1), the average reduction rate of Cr(VI) was 30.0 mg L(-1) d(-1), Pb(II) 32.7 mg L(-1) d(-1), and Ni(II) 8.9 mg L(-1) d(-1). An electrochemical model was developed to predict the change of metal concentration over time. The power output of the MFC was sufficient to meet the requirement of the ESC and MEC, and the "self-sustained metal reduction" was achieved in this hybrid system.

  13. Development of metal-coated ceramic anodes for molten carbonate fuel cells. Final report

    SciTech Connect

    Khandkar, A.C.; Elangovan, S.; Marianowski, L.G.

    1990-03-01

    This report documents the developmental efforts on metal coating of various ceramic substrates (LiAlO{sub 2}, SrTiO{sub 3}, and LiFeO{sub 2}) and the critical issues associated with fabricating anodes using metal-coated LiAlO{sub 2} substrates. Electroless Ni and Cu coating technology was developed to achieve complete metal coverage on LiAlO{sub 2} powder substrates. Metal coated SrTiO{sub 3} powders were fabricated into anodes by a process identical to that reported in the GE literature. Microstructural examination revealed that the grains of the ceramic had fused together, with the metal having dewetted from the surface of the ceramic. Alternate substrates that might allow for better wetting of the metal on the ceramic such as LiFeO{sub 2} and Li{sub 2}MnO{sub 3} were identified. Cu/Ni-coated (50:50 mol ratio, 50 w/o metal loading) LiFeO{sub 2} anodes were optimized to meet the MCFC anode specifications. Metal-coated gamma-LiAlO{sub 2} substrates were also developed. By using suitable chemical surface modification methods, the gamma-UAlO{sub 2} substrate surface may be modified to allow a stable metal coated anode to be fabricated. Creep testing of the metal coated ceramic anodes were conducted at IGT. It was determined that the predominant creep mechanism is due to particle rearrangement. The anode porosity, and mean pore size had significant effect on the creep of the anode. Lower porosity and pore size consistent with performance criteria are desired to reduce creep. Lower metal loading with uniformity of coverage will result in lower creep behavior of the anode. Of the two substrates evaluated, LiFeO{sub 2} in general exhibited lower creep which was attributed to superior metal adhesion.

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

    DOEpatents

    Gay, Eddie C.

    1995-01-01

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

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

    SciTech Connect

    Gay, E.C.

    1993-12-23

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

  16. Combinatorial electrochemical cell array for high throughput screening of micro-fuel-cells and metal/air batteries

    NASA Astrophysics Data System (ADS)

    Jiang, Rongzhong

    2007-07-01

    An electrochemical cell array was designed that contains a common air electrode and 16 microanodes for high throughput screening of both fuel cells (based on polymer electrolyte membrane) and metal/air batteries (based on liquid electrolyte). Electrode materials can easily be coated on the anodes of the electrochemical cell array and screened by switching a graphite probe from one cell to the others. The electrochemical cell array was used to study direct methanol fuel cells (DMFCs), including high throughput screening of electrode catalysts and determination of optimum operating conditions. For screening of DMFCs, there is about 6% relative standard deviation (percentage of standard deviation versus mean value) for discharge current from 10to20mA/cm2. The electrochemical cell array was also used to study tin/air batteries. The effect of Cu content in the anode electrode on the discharge performance of the tin/air battery was investigated. The relative standard deviations for screening of metal/air battery (based on zinc/air) are 2.4%, 3.6%, and 5.1% for discharge current at 50, 100, and 150mA/cm2, respectively.

  17. Combinatorial electrochemical cell array for high throughput screening of micro-fuel-cells and metal/air batteries.

    PubMed

    Jiang, Rongzhong

    2007-07-01

    An electrochemical cell array was designed that contains a common air electrode and 16 microanodes for high throughput screening of both fuel cells (based on polymer electrolyte membrane) and metal/air batteries (based on liquid electrolyte). Electrode materials can easily be coated on the anodes of the electrochemical cell array and screened by switching a graphite probe from one cell to the others. The electrochemical cell array was used to study direct methanol fuel cells (DMFCs), including high throughput screening of electrode catalysts and determination of optimum operating conditions. For screening of DMFCs, there is about 6% relative standard deviation (percentage of standard deviation versus mean value) for discharge current from 10 to 20 mAcm(2). The electrochemical cell array was also used to study tin/air batteries. The effect of Cu content in the anode electrode on the discharge performance of the tin/air battery was investigated. The relative standard deviations for screening of metal/air battery (based on zinc/air) are 2.4%, 3.6%, and 5.1% for discharge current at 50, 100, and 150 mAcm(2), respectively.

  18. Irradiation of Metallic Fuels with Rare Earth Additions for Actinide Transmutation in the ATR. Experiment Description for AFC-2A and AFC-2B

    SciTech Connect

    S. L. Hayes; D. J. Utterbeck; T. A. Hyde

    2007-03-01

    The U.S. Advanced Fuel Cycle Initiative (AFCI), now within the broader context of the Global Nuclear Energy Partnership (GNEP), seeks to develop and demonstrate the technologies needed to transmute the long-lived transuranic actinide isotopes contained in spent nuclear fuel into shorter-lived fission products, thereby dramatically decreasing the volume of material requiring disposal and the long-term radio-toxicity and heat load of high-level waste sent to a geologic repository. One important component of the technology development is actinide-bearing metallic transmutation fuel forms containing plutonium, neptunium, americium (and possibly curium) isotopes. The proposed AFC-2A and AFC-2B irradiation experiments are a continuation of the metallic fuel test series in progress in the ATR. This report documents the experiment description and test matrix of the proposed experiments and the Post Irradiation Examination (PIE) and fabrication schedule.

  19. Irradiation of Metallic Fuels with Rare Earth Additions for Actinide Transmutation in the Advanced Test Reactor. Experiment Description for AFC-2A and AFC-2B

    SciTech Connect

    Hayes, Steven L.

    2006-12-01

    The U.S. Advanced Fuel Cycle Initiative (AFCI), now within the broader context of the Global Nuclear Energy Partnership (GNEP), seeks to develop and demonstrate the technologies needed to transmute the long-lived transuranic actinide isotopes contained in spent nuclear fuel into shorter-lived fission products, thereby dramatically decreasing the volume of material requiring disposal and the long-term radio-toxicity and heat load of high-level waste sent to a geologic repository. One important component of the technology development is actinide-bearing metallic transmutation fuel forms containing plutonium, neptunium, americium (and possibly curium) isotopes. The proposed AFC-2A and AFC-2B irradiation experiments are a continuation of the metallic fuel test series in progress in the ATR. This report documents the experiment description and test matrix of the proposed experiments and the Post Irradiation Examination (PIE) and fabrication schedule.

  20. Irradiation of Metallic Fuels with Rare Earth Additions for Actinide Transmutation in the ATR. Experiment Description for AFC-2A and AFC-2B

    SciTech Connect

    S. L. Hayes; D. J. Utterbeck; T. A. Hyde

    2006-11-01

    The U.S. Advanced Fuel Cycle Initiative (AFCI), now within the broader context of the Global Nuclear Energy Partnership (GNEP), seeks to develop and demonstrate the technologies needed to transmute the long-lived transuranic actinide isotopes contained in spent nuclear fuel into shorter-lived fission products, thereby dramatically decreasing the volume of material requiring disposal and the long-term radio-toxicity and heat load of high-level waste sent to a geologic repository. One important component of the technology development is actinide-bearing metallic transmutation fuel forms containing plutonium, neptunium, americium (and possibly curium) isotopes. The proposed AFC-2A and AFC-2B irradiation experiments are a continuation of the metallic fuel test series in progress in the ATR. This report documents the experiment description and test matrix of the proposed experiments and the Post Irradiation Examination (PIE) and fabrication schedule.

  1. Nuclear fuel and precious-metal occurrences in Precambrian rocks of southeast Wyoming

    SciTech Connect

    Graff, P.

    1986-08-01

    Studies done on Precambrian metasediments in southeast Wyoming show the occurrence of quartz-pebble conglomerates containing subeconomic amounts of uranium and thorium. These conglomerates were marginal deposits in the late 1970s when uranium prices reached $50/lb. Fuel minerals occur in silicate phases and complicate milling operations. Because of the additional cost of processing and underground mining, no attempt to develop these resources was made. Additional studies show a favorable comparison of the rocks in Wyoming to the auriferous Witwatersrand section of South Africa. Exploration for gold in the Wyoming conglomerates has been done in a preliminary manner, but assay values to 10 ppm are reported. Both fuel minerals and gold are deposited as fossil placers by fluvial systems operating in an anoxic environment. Lag gravel and meander deposits contain heavy-mineral suites formed of coffinite, pyrite, thorite, gold, and uraninite. Available studies have not considered producing fuel and precious minerals as coproducts of surface mining methods.

  2. High pressure pyrolyzed non-precious metal oxygen reduction catalysts for alkaline polymer electrolyte membrane fuel cells

    NASA Astrophysics Data System (ADS)

    Sanetuntikul, Jakkid; Shanmugam, Sangaraju

    2015-04-01

    Non-precious metal catalysts, such as metal-coordinated to nitrogen doped-carbon, have shown reasonable oxygen reduction reaction (ORR) performances in alkaline fuel cells. In this report, we present the development of a highly active, stable and low-cost non-precious metal ORR catalyst by direct synthesis under autogenic-pressure conditions. Transmission electron microscopy studies show highly porous Fe-N-C and Co-N-C structures, which were further confirmed by Brunauer-Emmett-Teller surface area measurements. The surface areas of the Fe-N-C and Co-N-C catalysts were found to be 377.5 and 369.3 m2 g-1, respectively. XPS results show the possible existence of N-C and M-Nx structures, which are generally proposed to be the active sites in non-precious metal catalysts. The Fe-N-C electrocatalyst exhibits an ORR half-wave potential 20 mV higher than the reference Pt/C catalyst. The cycling durability test for Fe-N-C over 5000 cycles shows that the half-wave potential lost only 4 mV, whereas the half-wave potential of the Pt/C catalyst lost about 50 mV. The Fe-N-C catalyst exhibited an improved activity and stability compared to the reference Pt/C catalyst and it possesses a direct 4-electron transfer pathway for the ORR process. Further, the Fe-N-C catalyst produces extremely low HO2- content, as confirmed by the rotating ring-disk electrode measurements. In the alkaline fuel single cell tests, maximum power densities of 75 and 80 mW cm-2 were observed for the Fe-N-C and Pt/C cathodes, respectively. Durability studies (100 h) showed that decay of the fuel cell current was more prominent for the Pt/C cathode catalyst compared to the Fe-N-C cathode catalyst. Therefore, the Fe-N-C catalyst appears to be a promising new class of non-precious metal catalysts prepared by an autogenic synthetic method.Non-precious metal catalysts, such as metal-coordinated to nitrogen doped-carbon, have shown reasonable oxygen reduction reaction (ORR) performances in alkaline fuel cells. In

  3. Reduction of methanol crossover by thin cracked metal barriers at the interface between membrane and electrode in direct methanol fuel cells

    NASA Astrophysics Data System (ADS)

    Kim, Sungjun; Jang, Segeun; Kim, Sang Moon; Ahn, Chi-Yeong; Hwang, Wonchan; Cho, Yong-Hun; Sung, Yung-Eun; Choi, Mansoo

    2017-09-01

    This work reports the successful reduction in methanol crossover by creating a thin cracked metal barrier at the interface between a Nafion® membrane and an electrode in direct methanol fuel cells (DMFCs). The cracks are generated by simple mechanical stretching of a metal deposited Nafion® membrane as a result of the elastic mismatch between the two attached surfaces. The cracked metal barriers with varying strains (∼0.5 and ∼1.0) are investigated and successfully incorporated into the DMFC. Remarkably, the membrane electrode assembly with the thin metal crack exhibits comparable ohmic resistance as well as reduction of methanol crossover, which enhanced the device performance.

  4. Teaching Driver Education Technology to Novice Drivers.

    ERIC Educational Resources Information Center

    Young, Anthony

    A cybernetic unit in driver education was developed to help grade 10 students develop the skills needed to acquire and process driver education information and prepare for the driving phase of driver education in grade 11. Students used a simulator to engage in a series of scenarios designed to promote development of social, behavioral, and mental…

  5. Status of LMR fuel development in the United States of America

    SciTech Connect

    Leggett, R.D.; Walters, L.C.

    1992-12-01

    Three fuel systems - oxide, metal and carbide - are shown to be reliable to high burnup and a fourth system, nitride, is shown to have promise for LMR applications. The excellent steady state performance of the oxide and metal driver fuels for FFTF and EBR-II, respectively, as well as that of tens of thousands of test pins is provided. Achieving 300 MWd/kg in the oxide fuel system through the use of low swelling cladding and duct materials is described and arguments for economic viability are presented. Responses to operational transients and severe overpower events are shown to have large safety margins and run beyond cladding breach, RBCB, likewise, is shown to be nonthreatening to LMR reactor systems. The Integral Fast Reactor (IFR) concept that utilizes metallic fuel and the commercial viability of this concept are discussed. Results from a joint US-Swiss carbide test that operated successfully at high power and burnup in FFTF are also presented.

  6. Increasing the recovery of heavy metal ions using two microbial fuel cells operating in parallel with no power output.

    PubMed

    Wang, Xiaohui; Li, Jing; Wang, Zhao; Tursun, Hairti; Liu, Rui; Gao, Yanmei; Li, Yuan

    2016-10-01

    The present study aimed to improve the performance of microbial fuel cells (MFCs) by using an intermittent connection period without power output. Connecting two MFCs in parallel improved the voltage output of both MFCs until the voltage stabilized. Electric energy was accumulated in two MFCs containing heavy metal ions copper, zinc, and cadmium as electron acceptors by connection in parallel for several hours. The system was then switched to discharge mode with single MFCs with a 1000-Ω resistor connected between anode and cathode. This method successfully achieved highly efficient removal of heavy metal ions. Even when the anolyte was run in sequencing batch mode, the insufficient voltage and power needed to recover heavy metals from the cathode of MFCs can be complemented by the developed method. The average removal ratio of heavy metal ions in sequencing batch mode was 67 % after 10 h. When the discharge time was 20 h, the removal ratios of zinc, copper, and cadmium were 91.5, 86.7, and 83.57 %, respectively; the average removal ratio of these ions after 20 h was only 52.1 % for the control group. Therefore, the average removal efficiency of heavy metal ions increased by 1.75 times using the electrons stored from the bacteria under the open-circuit conditions in parallel mode. Electrochemical impedance data showed that the anode had lower solution resistance and polarization resistance in the parallel stage than as a single MFC, and capacitance increased with the length of time in parallel.

  7. Open framework metal chalcogenides as efficient photocatalysts for reduction of CO2 into renewable hydrocarbon fuel.

    PubMed

    Sasan, Koroush; Lin, Qipu; Mao, Chengyu; Feng, Pingyun

    2016-06-07

    Open framework metal chalcogenides are a family of porous semiconducting materials with diverse chemical compositions. Here we show that these materials containing covalent three-dimensional superlattices of nanosized supertetrahedral clusters can function as efficient photocatalysts for the reduction of CO2 to CH4. Unlike dense semiconductors, metal cations are successfully incorporated into the channels of the porous semiconducting materials to further tune the physical properties of the materials such as electrical conductivity and band gaps. In terms of the photocatalytic properties, the metal-incorporated porous chalcogenides demonstrated enhanced solar energy absorption and higher electrical conductivity and improved photocatalytic activity.

  8. Nonprecious metal catalysts for fuel cell applications: electrochemical dioxygen activation by a series of first row transition metal tris(2-pyridylmethyl)amine complexes.

    PubMed

    Ward, Ashleigh L; Elbaz, Lior; Kerr, John B; Arnold, John

    2012-04-16

    A series of divalent first row triflate complexes supported by the ligand tris(2-pyridylmethyl)amine (TPA) have been investigated as oxygen reduction catalysts for fuel cell applications. [(TPA)M(2+)](n+) (M = Mn, Fe, Co, Ni, and Cu) derivatives were synthesized and characterized by X-ray crystallography, cyclic voltammetry, NMR spectroscopy, magnetic susceptibility, IR spectroscopy, and conductance measurements. The stoichiometric and electrochemical O(2) reactivities of the series were examined. Rotating-ring disk electrode (RRDE) voltammetry was used to examine the catalytic activity of the complexes on a carbon support in acidic media, emulating fuel cell performance. The iron complex displayed a selectivity of 89% for four-electron conversion and demonstrated the fastest reaction kinetics, as determined by a kinetic current of 7.6 mA. Additionally, the Mn, Co, and Cu complexes all showed selective four-electron oxygen reduction (<28% H(2)O(2)) at onset potentials (~0.44 V vs RHE) comparable to state of the art molecular catalysts, while being straightforward to access synthetically and derived from nonprecious metals. © 2012 American Chemical Society

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

    SciTech Connect

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

    1992-09-01

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

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

    SciTech Connect

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

    1992-01-01

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

  11. Alkali activation of recovered fuel-biofuel fly ash from fluidised-bed combustion: Stabilisation/solidification of heavy metals.

    PubMed

    Yliniemi, Juho; Pesonen, Janne; Tiainen, Minna; Illikainen, Mirja

    2015-09-01

    Recovered fuel-biofuel fly ash from a fluidized bed boiler was alkali-activated and granulated with a sodium-silicate solution in order to immobilise the heavy metals it contains. The effect of blast-furnace slag and metakaolin as co-binders were studied. Leaching standard EN 12457-3 was applied to evaluate the immobilisation potential. The results showed that Ba, Pb and Zn were effectively immobilised. However, there was increased leaching after alkali activation for As, Cu, Mo, Sb and V. The co-binders had minimal or even negative effect on the immobilisation. One exception was found for Cr, in which the slag decreased leaching, and one was found for Cu, in which the slag increased leaching. A sequential leaching procedure was utilized to gain a deeper understanding of the immobilisation mechanism. By using a sequential leaching procedure it is possible fractionate elements into watersoluble, acid-soluble, easily-reduced and oxidisable fractions, yielding a total 'bioavailable' amount that is potentially hazardous for the environment. It was found that the total bioavailable amount was lower following alkali activation for all heavy metals, although the water-soluble fraction was higher for some metals. Evidence from leaching tests suggests the immobilisation mechanism was chemical retention, or trapping inside the alkali activation reaction products, rather than physical retention, adsorption or precipitation as hydroxides. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Laminated exfoliated graphite composite-metal compositions for fuel cell flow field plate or bipolar plate applications

    SciTech Connect

    Zhamu, Aruna; Shi, Jinjun; Guo, Jiusheng; Jang, Bor Z

    2014-05-20

    An electrically conductive laminate composition for fuel cell flow field plate or bipolar plate applications. The laminate composition comprises at least a thin metal sheet having two opposed exterior surfaces and a first exfoliated graphite composite sheet bonded to the first of the two exterior surfaces of the metal sheet wherein the exfoliated graphite composite sheet comprises: (a) expanded or exfoliated graphite and (b) a binder or matrix material to bond the expanded graphite for forming a cohered sheet, wherein the binder or matrix material is between 3% and 60% by weight based on the total weight of the first exfoliated graphite composite sheet. Preferably, the first exfoliated graphite composite sheet further comprises particles of non-expandable graphite or carbon in the amount of between 3% and 60% by weight based on the total weight of the non-expandable particles and the expanded graphite. Further preferably, the laminate comprises a second exfoliated graphite composite sheet bonded to the second surface of the metal sheet to form a three-layer laminate. Surface flow channels and other desired geometric features can be built onto the exterior surfaces of the laminate to form a flow field plate or bipolar plate. The resulting laminate has an exceptionally high thickness-direction conductivity and excellent resistance to gas permeation.

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

    DOEpatents

    Gay, E.C.

    1995-10-03

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

  14. Metal Nanoshells for Plasmonically Enhanced Solar-to-Fuel Photocatalytic Conversion

    DTIC Science & Technology

    2014-05-09

    adjustment of the ratios of [Zn]/[In], the hydrogen production rate of the photocatalysts , particle sizes, and band gap are significantly different. In the...following experiments, the core-shell of nanoshell@SiO2, as well as the nanostructure of photocatalyst , were further investigated. Solar energy in the...visible-light range is expected to be absorbed by the photocatalyst first without any interference from the metal nanoshells. The presence of metal

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

    SciTech Connect

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

    2012-04-01

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

  16. Failed fuel monitoring and surveillance techniques for liquid metal cooled fast reactors

    SciTech Connect

    Lambert, J.D.B.; Mikaili, R.; Gross, K.C.; Strain, R.V.; Aoyama, T.; Ukai, S.; Nomura, S.; Nakae, N.

    1995-05-01

    The Experimental Breeder Reactor II (EBR-II) has been used as a facility for irradiation of LMR fuels and components for thirty years. During this time many tests of experimental fuel were continued to cladding breach in order to study modes of element failure; the methods used to identify such failures are described in a parallel paper. This paper summarizes experience of monitoring the delayed-neutron (DN) and fission-gas (FG) release behavior of a smaller number of elements that continued operation in the run-beyond-cladding-breach (RBCB) mode. The scope of RBCB testing, the methods developed to characterize failures on-line, and examples of DN/FG behavior are described.

  17. Metallic inert matrix fuel concept for minor actinides incineration to achieve ultra-high burn-up

    NASA Astrophysics Data System (ADS)

    Lipkina, K.; Savchenko, A.; Skupov, M.; Glushenkov, A.; Vatulin, A.; Uferov, O.; Ivanov, Y.; Kulakov, G.; Ershov, S.; Maranchak, S.; Kozlov, A.; Maynikov, E.; Konova, K.

    2014-09-01

    The advantages of using Inert Matrix Fuel (IMF) in a design of an isolated arrangement of fuel are considered, with emphasis on, low temperatures in the fuel center, achievement of high burn-ups, and an environment friendly process for the fuel element fabrication. Changes in the currently existing concept of IMF usage are suggested, involving novel IMF design in the nuclear fuel cycle.

  18. Modeling of polymer electrolyte membrane fuel cell with metal foam in the flow-field of the bipolar/end plates

    NASA Astrophysics Data System (ADS)

    Kumar, Atul; Reddy, R. G.

    A unified, three-dimensional, steady-state numerical mass-transfer single cell model for polymer electrolyte membrane fuel cell (PEMFC) was developed. The modeled fuel cell uses metal foam in the flow-field of the bipolar/end plates instead of the conventionally used rectangular channels. Transport equations formulated under the PEMFC conditions were solved using the commercial computational fluid dynamics software Fluent ® 6.0 with Gambit ® 2.0 as pre-processor. Simulations were performed for different permeability levels of the metal foam in the flow-field. Results showed a significant effect of permeability of the metal foam on the performance of the fuel cell. For example: at 10 -6 m 2 permeability of metal foam the value of average current density was 5943 A/m 2 while at 10 -11 m 2 permeability, the average current density was 8325 A/m 2. The average current density value for the multi-parallel flow-field channel design (channel width=0.0625 in., channel depth=0.0625 in. and land width=0.0625 in.), which corresponded to an equivalent permeability value of 4.4×10 -8 m 2 was 7019 A/m 2. This value for the porous configuration with same permeability and under similar conditions of temperature, pressure and reactants flow rate was slightly lower at 6794 A/m 2. The trend indicated that decreasing the permeability of the flow-field results in better performance from the cell. However, the permeability of the channel design can not be decreased below the value of around 10 -8 m 2, due to difficulty in machining thinner channels. Consequently, the use of metal foam flow-field is proposed in the bipolar/end plate. The developed model offers fuel cell developers a scope for improvement of the bipolar/end plates in the fuel cell, by switching over to the metal foam flow-field concept.

  19. Design Principles for Metal Oxide Redox Materials for Solar-Driven Isothermal Fuel Production

    PubMed Central

    Michalsky, Ronald; Botu, Venkatesh; Hargus, Cory M; Peterson, Andrew A; Steinfeld, Aldo

    2015-01-01

    The performance of metal oxides as redox materials is limited by their oxygen conductivity and thermochemical stability. Predicting these properties from the electronic structure can support the screening of advanced metal oxides and accelerate their development for clean energy applications. Specifically, reducible metal oxide catalysts and potential redox materials for the solar-thermochemical splitting of CO2 and H2O via an isothermal redox cycle are examined. A volcano-type correlation is developed from available experimental data and density functional theory. It is found that the energy of the oxygen-vacancy formation at the most stable surfaces of TiO2, Ti2O3, Cu2O, ZnO, ZrO2, MoO3, Ag2O, CeO2, yttria-stabilized zirconia, and three perovskites scales with the Gibbs free energy of formation of the bulk oxides. Analogously, the experimental oxygen self-diffusion constants correlate with the transition-state energy of oxygen conduction. A simple descriptor is derived for rapid screening of oxygen-diffusion trends across a large set of metal oxide compositions. These general trends are rationalized with the electronic charge localized at the lattice oxygen and can be utilized to predict the surface activity, the free energy of complex bulk metal oxides, and their oxygen conductivity. PMID:26855639

  20. Micro-solid oxide fuel cell supported on a porous metallic Ni/stainless-steel bi-layer

    NASA Astrophysics Data System (ADS)

    Lee, Younki; Park, Young Min; Choi, Gyeong Man

    2014-03-01

    Metallic bi-layer of porous Ni and porous stainless steel (STS) is utilized as a support for micro-solid oxide fuel cells (SOFCs) using a thin-film layer of electrolyte. Tape-casting and screen-printing processes are employed to fabricate a thick (∼250 μm) STS-layer covered with a thin (∼20 μm) nano-porous Ni layer. Successful deposition of a nearly pore-free electrolyte layer by the pulsed laser deposition (PLD) method is demonstrated by the high open-circuit-voltage (OCV) value of a single cell. The Ohmic resistance of the micro-SOFC deposited on a porous Ni/STS-support is stable and it shows ∼28 mW cm-2 after operation for ∼112 h at 450 °C. The use of a porous Ni/STS bi-layer as a support for micro-SOFCs is successfully demonstrated.

  1. Understanding of Electrochemical Mechanisms for CO2 Capture and Conversion into Hydrocarbon Fuels in Transition-Metal Carbides (MXenes).

    PubMed

    Li, Neng; Chen, Xingzhu; Ong, Wee-Jun; MacFarlane, Douglas R; Zhao, Xiujian; Cheetham, Anthony K; Sun, Chenghua

    2017-09-13

    Two-dimensional (2D) transition-metal (groups IV, V, VI) carbides (MXenes) with formulas M3C2 have been investigated as CO2 conversion catalysts with well-resolved density functional theory calculations. While MXenes from the group IV to VI series have demonstrated an active behavior for the capture of CO2, the Cr3C2 and Mo3C2 MXenes exhibit the most promising CO2 to CH4 selective conversion capabilities. Our results predicted the formation of OCHO(•) and HOCO(•) radical species in the early hydrogenation steps through spontaneous reactions. This provides atomic level insights into the computer-aided screening for high-performance catalysts and the understanding of electrochemical mechanisms for CO2 reduction to energy-rich hydrocarbon fuels, which is of fundamental significance to elucidate the elementary steps for CO2 fixation.

  2. Nitrogen oxides reduction by carbonaceous materials and carbon dioxide separation using regenerative metal oxides from fossil fuel based flue gas

    NASA Astrophysics Data System (ADS)

    Gupta, Himanshu

    The ever-growing energy demands due to rising global population and continuing lifestyle improvements has placed indispensable emphasis on fossil fuels. Combustion of fossil fuels leads to the emission of harmful gaseous pollutants such as oxides of sulfur (SOx) and nitrogen (NOx), carbon dioxide (CO2), mercury, particulate matter, etc. Documented evidence has proved that this air pollution leads to adverse environmental health. This dissertation focuses on the development of technologies for the control of NOx and CO2 emissions. The first part of the thesis (Chapters 2--6) deals with the development of carbon based post combustion NOx reduction technology called CARBONOX process. High temperature combustion oxidizes both atmospheric nitrogen and organic nitrogen in coal to nitric oxide (NO). The reaction rate between graphite and NO is slow and requires high temperature (>900°C). The presence of metallic species in coal char catalyzes the reaction. The reaction temperature is lowered in the presence of oxygen to about 600--850°C. Chemical impregnation, specifically sodium compounds, further lowers the reaction temperature to 350--600°C. Activated high sodium lignite char (HSLC) provided the best performance for NO reduction. The requirement of char for NOx reduction is about 8--12 g carbon/g NO reduced in the presence of 2% oxygen in the inlet gas. The second part of this dissertation (chapter 7--8) focuses on the development of a reaction-based process for the separation of CO2 from combustion flue gas. Certain metal oxides react with CO2 forming metal carbonates under flue gas conditions. They can be calcined separately to yield CO2. Calcium oxide (CaO) has been identified as a viable metal oxide for the carbonation-calcination reaction (CCR) scheme. CaO synthesized from naturally occurring precursors (limestone and dolomite) attained 45--55% of their stoichiometric conversion due to the susceptibility of their microporous structure. High surface area

  3. Double-chamber microbial fuel cell with a non-platinum-group metal Fe-N-C cathode catalyst.

    PubMed

    Santoro, Carlo; Serov, Alexey; Narvaez Villarrubia, Claudia W; Stariha, Sarah; Babanova, Sofia; Schuler, Andrew J; Artyushkova, Kateryna; Atanassov, Plamen

    2015-03-01

    Non-Pt-group metal (non-PGM) materials based on transition metal-nitrogen-carbon (M-N-C) and derived from iron salt and aminoantipyrine (Fe-AAPyr) of mebendazole (Fe-MBZ) were studied for the first time as cathode catalysts in double-chamber microbial fuel cells (DCMFCs). The pH value of the cathode chamber was varied from 6 to 11 to elucidate the activity of those catalysts in acidic to basic conditions. The Fe-AAPyr- and Fe-MBZ-based cathodes were compared to a Pt-based cathode used as a baseline. Pt cathodes performed better at pH 6-7.5 and had similar performances at pH 9 and a substantially lower performance at pH 11 at which Fe-AAPyr and Fe-MBZ demonstrated their best electrocatalytic activity. The power density achieved with Pt constantly decreased from 94-99 μW cm(-2) at pH 6 to 55-57 μW cm(-2) at pH 11. In contrast, the power densities of DCMFs using Fe-AAPyr and Fe-MBZ were 61-68 μW cm(-2) at pH 6, decreased to 51-58 μW cm(-2) at pH 7.5, increased to 65-75 μW cm(-2) at pH 9, and the highest power density was achieved at pH 11 (68-80 μW cm(-2) ). Non-PGM cathode catalysts can be manufactured at the fraction of the cost of the Pt-based ones. The higher performance and lower cost indicates that non-PGM catalysts may be a viable materials choice in large-scale microbial fuel cells.

  4. Synthesis and characterization of new ternary transition metal sulfide anodes for H 2S-powered solid oxide fuel cell

    NASA Astrophysics Data System (ADS)

    Vorontsov, V.; Luo, J. L.; Sanger, A. R.; Chuang, K. T.

    A number of ternary transition metal sulfides with general composition AB 2S 4 (where A and B are different transition metal atoms) have been prepared and investigated as potential anode catalysts for use in H 2S-powered solid oxide fuel cells (SOFCs). For the initial screening, polarization resistance of the materials was measured in a two electrode symmetrical cell at 700-850 °C. Vanadium-based materials showed the lowest polarization resistance, and so were chosen for subsequent full cell tests using the configuration [H 2S, AV 2S 4/YSZ/Pt, air] (where A = Ni, Cr, Mo). MoV 2S 4 anode had superior activity and performance in the full cell setup, consistent with results from symmetrical cell tests. Polarization curves showed MoV 2S 4 had the lowest potential drop, with up to a 200 mA cm -2 current density at 800 °C. The highest power density of ca. 275 mW cm -2 at 800 °C was obtained with a pure H 2S stream. Polarization resistance of materials was a strong function of current density, and showed a sharp change of slope attributable to a change in the rate-limiting step of the anode reaction mechanism. MoV 2S 4 was chemically stable during prolonged (10 days) exposure to H 2S at 850 °C, and fuel cell performance was stable during continuous 3-day operation at 370 mA cm -2 current density.

  5. Thermal coupling potential of Solid Oxide Fuel Cells with metal hydride tanks: Thermodynamic and design considerations towards integrated systems

    NASA Astrophysics Data System (ADS)

    Yiotis, Andreas G.; Kainourgiakis, Michael E.; Kosmidis, Lefteris I.; Charalambopoulou, Georgia C.; Stubos, Athanassios K.

    2014-12-01

    We study the thermal coupling potential between a high temperature metal hydride (MH) tank and a Solid Oxide Fuel Cell (SOFC) aiming towards the design of an efficient integrated system, where the thermal power produced during normal SOFC operation is redirected towards the MH tank in order to maintain H2 desorption without the use of external heating sources. Based on principles of thermodynamics, we calculate the energy balance in the SOFC/MH system and derive analytical expressions for both the thermal power produced during SOFC operation and the corresponding thermal power required for H2 desorption, as a function of the operating temperature, efficiency and fuel utilization ratio in the SOFC, and the MH enthalpy of desorption in the tank. Based on these calculations, we propose an integrated SOFC/MH design where heat is transferred primarily by radiation to the tank in order to maintain steady-state desorption conditions. We develop a mathematical model for this particular design that accounts for heat/mass transfer and desorption kinetics in the tank, and solve for the dynamics of the system assuming MgH2 as a storage material. Our results focus primarily on tank operating conditions, such as pressure, temperature and H2 saturation profiles vs operation time.

  6. Metal-supported solid oxide fuel cells with impregnated SrFe0.75Mo0.25O3 cathodes

    NASA Astrophysics Data System (ADS)

    Zhou, Yucun; Meng, Xie; Ye, Xiaofeng; Li, Junliang; Wang, Shaorong; Zhan, Zhongliang

    2014-02-01

    This paper reports on the fabrication in reducing atmospheres of SrFe0.75Mo0.25O3 (SFMO)-8 mol%Y2O3-stabilized ZrO2 (YSZ) composites by impregnating Sr2+-, Fe3+- and Mo7O246--containing solutions into the porous YSZ backbones, which would find important applications as cathodes for co-fired metal-supported solid oxide fuel cells. X-ray diffraction examination shows that as-synthesized infiltrates consist of perovskite SFMO oxides and metallic Fe. In situ oxidation during the fuel cell operation eliminates metallic Fe, and SFMO oxides become the predominant component with some minor SrMoO4 impurities. Impedance measurements on symmetric cathode fuel cells show that such impregnated SFMO-YSZ composites exhibit low polarization resistances in air, e.g., 0.06 Ω cm2 at 800 °C. Metal-supported solid oxide fuel cells, consisting of porous 430L stainless steel substrates, Ni-YSZ active anodes, YSZ electrolytes and impregnated SFMO-YSZ composite cathodes, are fabricated using tape casting, tape lamination, co-sintering and solution impregnation techniques, and show maximum power densities of 438 mW cm-2 at 800 °C and 221 mW cm-2 at 700 °C.

  7. Evaluation of the emission characteristics of trace metals from coal and fuel oil fired power plants and their fate during combustion.

    PubMed

    Reddy, M Srinivasa; Basha, Shaik; Joshi, H V; Jha, B

    2005-08-31

    Coal as well as fuel oil combustion generates emissions of potentially toxic trace pollutants including organic and inorganic chemical compounds besides major pollutants. A study on As, Cd, Co, Cr, Cu, Hg, Fe, Mn, Ni, Pb, Se, and Zn emissions from a 220 MW coal-fired power plant equipped with a electrostatic precipitators (ESPs) and 6 MW oil fired-power plant was carried out, using stack monitoring kit, Envirotech APM 620, which is similar to EPA Method 29. Simultaneous sampling of coal, fuel oil, oil waste, bottom ash, fly ash, flue gases, and particles associated with the gas phase has been performed. This sampling method was used for trace metal sampling. The content of all these metals in coal, oil, oil waste, bottom ash, fly ash have been determined by XRF, whereas their contents in the flue gases, and particles associated with the gas phase has been analyzed with ICP-AES. The mass balances obtained for trace elements were satisfactory in case of fuel oil based power plant, whereas in case of coal fired power plant, the mass balance for all the trace elements were below 50% except for the As, Se, and Hg. The enrichment factors for all trace metals was <1 in both cases. The above sampling method is moderately adequate method for trace element sampling in coal as well as oil fired power plants except for Hg. The results indicate that trace metals emissions were higher in coal-based power plant than the fuel oil-fired power plant.

  8. A New Process for Hot Metal Production at Low Fuel Rate - Phase 1 Feasibility Study

    SciTech Connect

    Dr. Wei-Kao Lu

    2006-02-01

    The project is part of the continuing effort by the North American steel industry to develop a coal-based, cokeless process for hot metal production. The objective of Phase 1 is to determine the feasibility of designing and constructing a pilot scale facility with the capacity of 42,000 mtpy of direct reduced iron (DRI) with 95% metallization. The primary effort is performed by Bricmont, Inc., an international engineering firm, under the supervision of McMaster University. The study focused on the Paired Straight Hearth furnace concept developed previously by McMaster University, The American Iron and Steel Institute and the US Department of Energy.

  9. Fuel/cladding compatibility in high-burnup U-19 Pu-10 Zr/HT-9 clad fuel at elevated temperatures

    SciTech Connect

    Cohen, A.B.; Tsai, H.; Sanecki, J.E.; Neimark, L.A. )

    1992-01-01

    The U-Pu-Zr metallic fuel in the integral fast reactor may interact chemically with the steel cladding at elevated temperatures, leading to a thinning of the cladding and eventual pin failure. Also, as a result of the fuel/cladding chemical interaction (FCCI), iron may diffuse into the fuel and form a lower melting phase with uranium and plutonium. If the temperature is raised above the solidus temperature of this phase, the fuel can undergo liquefaction, i.e., the formation of a mixture of liquid and solid phases, that may promote further cladding interaction. Fuel/cladding chemical interaction, therefore, is a complex phenomenon on both sides of the fuel/cladding interface that depends on fuel and cladding compositions, linear power rating, burnup, and cladding temperature. The purpose of this study was to determine the temperature at which the fuel/cladding interaction region forms solid-plus-liquid phases above the normal in-reactor operating temperatures of high-burnup (11 at.%) Mark V-type fuel for the Experimental Breeder Reactor II (EBR-II). The Mark V fuel is being developed as a future driver fuel for the reactor. The effect of this solid-plus-liquid mixture on the kinetics and mechanism of FCCI was also investigated. This paper updates results previously reported for lower-burnup Mark V-type fuel elements.

  10. Application of Neutron-Absorbing Structural-Amorphous Metal (SAM) Coatings for Spent Nuclear Fuel (SNF) Container to Enhance Criticality Safety Control

    SciTech Connect

    Choi, J

    2007-01-12

    This report describes the analysis and modeling approaches used in the evaluation for criticality-control applications of the neutron-absorbing structural-amorphous metal (SAM) coatings. The applications of boron-containing high-performance corrosion-resistant material (HPCRM)--amorphous metal as the neutron-absorbing coatings to the metallic support structure can enhance criticality safety controls for spent nuclear fuel in baskets inside storage containers, transportation casks, and disposal containers. The use of these advanced iron-based, corrosion-resistant materials to prevent nuclear criticality in transportation, aging, and disposal containers would be extremely beneficial to the nuclear waste management programs.

  11. Metal-Free Carbon-Based Materials: Promising Electrocatalysts for Oxygen Reduction Reaction in Microbial Fuel Cells

    PubMed Central

    Sawant, Sandesh Y.; Han, Thi Hiep; Cho, Moo Hwan

    2016-01-01

    Microbial fuel cells (MFCs) are a promising green approach for wastewater treatment with the simultaneous advantage of energy production. Among the various limiting factors, the cathodic limitation, with respect to performance and cost, is one of the main obstacles to the practical applications of MFCs. Despite the high performance of platinum and other metal-based cathodes, their practical use is limited by their high cost, low stability, and environmental toxicity. Oxygen is the most favorable electron acceptor in the case of MFCs, which reduces to water through a complicated oxygen reduction reaction (ORR). Carbon-based ORR catalysts possessing high surface area and good electrical conductivity improve the ORR kinetics by lowering the cathodic overpotential. Recently, a range of carbon-based materials have attracted attention for their exceptional ORR catalytic activity and high stability. Doping the carbon texture with a heteroatom improved their ORR activity remarkably through the favorable adsorption of oxygen and weaker molecular bonding. This review provides better insight into ORR catalysis for MFCs and the properties, performance, and applicability of various metal-free carbon-based electrocatalysts in MFCs to find the most appropriate cathodic catalyst for the practical applications. The approaches for improvement, key challenges, and future opportunities in this field are also explored. PMID:28029116

  12. Characteristics of electricity production by metallic and nonmetallic anodes immersed in mud sediment using sediment microbial fuel cell

    NASA Astrophysics Data System (ADS)

    Haque, N.; Cho, D.; Kwon, S.

    2015-09-01

    Sediment microbial fuel cell (SMFC), equipped with Zn, Al, Cu, Fe or graphite felt (GF) anode and marine sediment, was performed. Graphite felt was used as a common cathode. SMFC was single chambered and did not use any redox mediator. The aim of this work was to find efficient anodic material. Oxidation reduction potential (ORP), cell voltage, current density, power density, pH and chemical oxygen demand (COD) were measured for SMFC's performance. The order of maximum power density was 913 mWm-2 for Zn, 646 mWm-2 for Fe, 387.8 mWm-2 for Cu, 266 mWm-2 for Al, and 127 mWm-2 for GF. The current density over voltage was found to be strongly correlated one another in most metal electrodes but the graphite felt electrode, in which relatively weaker electricity was observed because of its biooriented mechanism. Metal corrosion reactions and/or a complicated microbial electron transfer mechanism acting around the anodic compartment may facilitate to generate electricity. We presume that more sophisticated selection of anodic material can lead to better performance in SMFC.

  13. Metal-Free Carbon-Based Materials: Promising Electrocatalysts for Oxygen Reduction Reaction in Microbial Fuel Cells.

    PubMed

    Sawant, Sandesh Y; Han, Thi Hiep; Cho, Moo Hwan

    2016-12-24

    Microbial fuel cells (MFCs) are a promising green approach for wastewater treatment with the simultaneous advantage of energy production. Among the various limiting factors, the cathodic limitation, with respect to performance and cost, is one of the main obstacles to the practical applications of MFCs. Despite the high performance of platinum and other metal-based cathodes, their practical use is limited by their high cost, low stability, and environmental toxicity. Oxygen is the most favorable electron acceptor in the case of MFCs, which reduces to water through a complicated oxygen reduction reaction (ORR). Carbon-based ORR catalysts possessing high surface area and good electrical conductivity improve the ORR kinetics by lowering the cathodic overpotential. Recently, a range of carbon-based materials have attracted attention for their exceptional ORR catalytic activity and high stability. Doping the carbon texture with a heteroatom improved their ORR activity remarkably through the favorable adsorption of oxygen and weaker molecular bonding. This review provides better insight into ORR catalysis for MFCs and the properties, performance, and applicability of various metal-free carbon-based electrocatalysts in MFCs to find the most appropriate cathodic catalyst for the practical applications. The approaches for improvement, key challenges, and future opportunities in this field are also explored.

  14. Characteristics of electricity production by metallic and nonmetallic anodes immersed in mud sediment using sediment microbial fuel cell

    NASA Astrophysics Data System (ADS)

    Haque, N.; Cho, D.; Kwon, S.

    2015-09-01

    Sediment microbial fuel cell (SMFC), equipped with Zn, Al, Cu, Fe orgraphite felt (GF) anodeand marine sediment, was performed. Graphite felt was used as a common cathode. SMFC was single chambered and did not use any redox mediator. The aimof this workwas to find efficient anodic material. Oxidation reduction potential (ORP), cell voltage, current density, power density, pH and chemical oxygen demand (COD) were measured for SMFC's performance.The order of maximum power density was 913 mWm-2 for Zn, 646 mWm-2 for Fe, 387.8 mWm-2 for Cu, 266 mWm-2 for Al, and 127 mWm-2 for GF. The current density over voltage was found to be strongly correlated one another in most metal electrodesbutthe graphite felt electrode, in which relatively weaker electricity was observed because of its bio-oriented mechanism. Metal corrosion reactionsand/or a complicated microbial electron transfer mechanismacting around the anodiccompartment may facilitate to generate electricity. We presume that more sophisticated selection of anodic material can lead to better performance in SMFC.

  15. Methodology for the design of accelerated stress tests for non-precious metal catalysts in fuel cell cathodes

    NASA Astrophysics Data System (ADS)

    Sharabi, Ronit; Wijsboom, Yair Haim; Borchtchoukova, Nino; Finkelshtain, Gennadi; Elbaz, Lior

    2016-12-01

    In this work we propose systematic methods for testing non-precious group metal catalysts and support degradation alkaline fuel cell cathodes. In this case study, we used a cathode composed of a pyrolyzed non-precious metal catalyst (NPMC) on activated carbon. The vulnerabilities of the cathode components were studied in order to develop the methodology and design an accelerated stress test (AST) for NPMC-based cathode in alkaline environment. Cyclic voltammetry (CV), chronoamperometry (CA) and impedance spectroscopy (EIS) were used to characterize the electrochemical behavior of the cathode and to follow the changes that occur as a result of exposing the cathodes to extreme operating conditions. Rotating ring disk electrode (RRDE) was used to study the cathodes kinetics; Raman spectroscopy and X-ray fluorescence (XRF) were used to study the structural changes in the electrode surface as well as depletion of the catalysts' active sites from the electrode. The changes in the composition of the electrode and catalyst were detected using X-ray diffraction (XRD). For the first time, we show that NPMC degrade rapidly at low operating potentials whereas the support degrades at high operating potentials and developed a tailor-made AST to take these into account.

  16. Advanced cathode materials for polymer electrolyte fuel cells based on pt/ metal oxides: from model electrodes to catalyst systems.

    PubMed

    Fabbri, Emiliana; Pătru, Alexandra; Rabis, Annett; Kötz, Rüdiger; Schmidt, Thomas J

    2014-01-01

    The development of stable catalyst systems for application at the cathode side of polymer electrolyte fuel cells (PEFCs) requires the substitution of the state-of-the-art carbon supports with materials showing high corrosion resistance in a strongly oxidizing environment. Metal oxides in their highest oxidation state can represent viable support materials for the next generation PEFC cathodes. In the present work a multilevel approach has been adopted to investigate the kinetics and the activity of Pt nanoparticles supported on SnO2-based metal oxides. Particularly, model electrodes made of SnO2 thin films supporting Pt nanoparticles, and porous catalyst systems made of Pt nanoparticles supported on Sb-doped SnO2 high surface area powders have been investigated. The present results indicate that SnO2-based supports do not modify the oxygen reduction reaction mechanism on the Pt nanoparticle surface, but rather lead to catalysts with enhanced specific activity compared to Pt/carbon systems. Different reasons for the enhancement in the specific activity are considered and discussed.

  17. An experimental evaluation of metallic diaphragms for positive fuel expulsion in the Atmosphere Explorer, hydrazine propulsion subsystem

    NASA Technical Reports Server (NTRS)

    Woodruff, W. L.

    1973-01-01

    Four Arde conospheroid metallic diaphragms were tested at NASA to evaluate their capability for use in the orbit adjust propulsion subsystem (OAPS) of the Atmosphere Explorer spacecraft (AE's C, D, and E). The diaphragms will be used for positive propellant expulsion and spacecraft center of mass (c.m.) control. A leak-free cycle life capability of nine reversals was demonstrated. The diaphragms rolled smoothly from ring to ring in a predictable manner on the first reversal. Varying amounts of diaphragm cocking and ring skipping were observed on subsequent reversals. The diaphragm pressure differential did not exceed 10 psid during any reversal. Cycle life capability, reversal mode, and pressure differential were not affected by sudden reversals, environmental tests, or 18,000 partial reversals. An expulsion efficiency of approximately 97 percent was demonstrated. The results of these tests show that metallic diaphragms can be used as an effective means of positive fuel expulsion; however, to achieve spacecraft c.m. control, the diaphragm must not be reversed prior to flight.

  18. The influence of different metal ions on light scattering properties of pattern microbial fuel cells' bacteria Desulfuromonas acetoxidans

    NASA Astrophysics Data System (ADS)

    Vasyliv, Oresta M.; Bilyy, Olexsandr I.; Getman, Vasyl'B.; Ferensovyich, Yaroslav P.; Yaremyk, Roman Y.; Hnatush, Svitlana O.

    2011-09-01

    Microbial fuel cell (MFC) technologies represent the newest approach for generating electricity - bioelectricity generation from biomass using bacteria. Desulfuromonas acetoxidans are aquatic obligatory anaerobic sulfur-reducing bacteria that possess an ability to produce electric current in the processes of organic matter oxidation and Fe3+- or Mn4+- reduction. These are pattern objects for MFC systems. They could be applied as a highly effective and self-sustaining model of wastewater treatment which contains energy in the form of biodegradable organic matter. But wastewaters contain high concentrations of xenobiotics, such as different heavy metals that have a detrimental effect towards all living organisms. The influence of different concentrations of MnCl2×4H2O, FeSO4 CuSO4, CdSO4, ZnSO4 and PbNO3 on light scattering properties of aquatic D. acetoxidans bacteria on the base of their cells' size distribution and relative content has been investigated by the new method of measurement. The cell distribution curve was in the range of 0.4 - 1.4 μm. The most crucial changes of cell concentration dependences, compared with other investigated metal ions, have been observed under the influence of copper ions. The ability of D. acetoxidans bacteria to produce electric current upon the specific cultivation conditions and the influence of Fe2+ and Mn2+ has been verified.

  19. Dispersion and thermal interactions of molten metal fuel settling on a horizontal steel plate through a sodium pool

    SciTech Connect

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

    1989-01-01

    Although the Integral Fast Reactor (IFR) possesses inherent safety features, an assessment of the consequences of melting of the metal fuel is necessary for risk analysis. As part of this effort an experimental study was conducted to determine the depths of sodium at 600 C required for pour streams of various molten uranium alloys (U, U-5 wt % Zr, U-10 wt % Zr, and U-10 wt % Fe) to break up and solidify. The quenched particulate material, which was in the shape of filaments and sheets, formed coolable beds because of the high voidage ({approximately}0.9) and large particle size ({approximately}10 mm). In a test with a 0.15-m sodium depth, the fragments from a pure uranium pour stream did not completely solidify but formed an agglomerated mass which did not fuse to the base plate. However, the agglomerated fragments of U-10 wt % Fe eutectic fused to the stainless steel base plate. An analysis of the temperature response of a 25-mm thick base plate was made by volume averaging the properties of the sodium and metal particle phases and assuming two semi-infinite solids coming into contact. Good agreement was obtained with the data during the initial 5 to 10 s of the contact period. 16 refs., 5 figs., 1 tab.

  20. Surface science and electrochemical studies of metal-modified carbides for fuel cells and hydrogen production

    NASA Astrophysics Data System (ADS)

    Kelly, Thomas Glenn

    Carbides of the early transition metals have emerged as low-cost catalysts that are active for a wide range of reactions. The surface chemistry of carbides can be altered by modifying the surface with small amounts of admetals. These metal-modified carbides can be effective replacements for Pt-based bimetallic systems, which suffer from the drawbacks of high cost and low thermal stability. In this dissertation, metal-modified carbides were studied for reactions with applications to renewable energy technologies. It is demonstrated that metal-modified carbides possess high activity for alcohol reforming and electrochemical hydrogen production. First, the surface chemistry of carbides towards alcohol decomposition is studied using density functional theory (DFT) and surface science experiments. The Vienna Ab initio Simulation Package (VASP) was used to calculate the binding energies of alcohols and decomposition intermediates on metal-modified carbides. The calculated binding energies were then correlated to reforming activity determined experimentally using temperature programmed desorption (TPD). In the case of methanol decomposition, it was found that tungsten monocarbide (WC) selectively cleaved the C-O bond to produce methane. Upon modifying the surface with a single layer of metal such as Ni, Pt, or Rh, the selectivity shifted towards scission of the C-H bonds while leaving the C-O bond intact, producing carbon monoxide (CO) and H2. High resolution energy loss spectroscopy (HREELS) was used to examine the bond breaking sequence as a function of temperature. From HREELS, it was shown that the surfaces followed an activity trend of Rh > Ni > Pt. The Au-modified WC surface possessed too low of a methanol binding energy, and molecular desorption of methanol was the most favorable pathway on this surface. Next, the ability of Rh-modified WC to break the C-C bond of C2 and C3 alcohols was demonstrated. HREELS showed that ethanol decomposed through an acetaldehyde

  1. Tolerance of non-platinum group metals cathodes proton exchange membrane fuel cells to air contaminants

    NASA Astrophysics Data System (ADS)

    Reshetenko, Tatyana; Serov, Alexey; Artyushkova, Kateryna; Matanovic, Ivana; Sarah Stariha; Atanassov, Plamen

    2016-08-01

    The effects of major airborne contaminants (SO2, NO2 and CO) on the spatial performance of Fe/N/C cathode membrane electrode assemblies were studied using a segmented cell system. The injection of 2-10 ppm SO2 in air stream did not cause any performance decrease and redistribution of local currents due to the lack of stably adsorbed SO2 molecules on Fe-Nx sites, as confirmed by density functional theory (DFT) calculations. The introduction of 5-20 ppm of CO into the air stream also did not affect fuel cell performance. The exposure of Fe/N/C cathodes to 2 and 10 ppm NO2 resulted in performance losses of 30 and 70-75 mV, respectively. DFT results showed that the adsorption energies of NO2 and NO were greater than that of O2, which accounted for the observed voltage decrease and slight current redistribution. The cell performance partially recovered when the NO2 injection was stopped. The long-term operation of the fuel cells resulted in cell performance degradation. XPS analyses of Fe/N/C electrodes revealed that the performance decrease was due to catalyst degradation and ionomer oxidation. The latter was accelerated in the presence of air contaminants. The details of the spatial performance and electrochemical impedance spectroscopy results are presented and discussed.

  2. Safe on-line refurbishment of separation plants for metal fuel

    SciTech Connect

    Hall, J.R.; Ashworth, A.B

    1991-11-01

    Plants and related facilities dedicated to Magnox fuel reprocessing at Sellafield were developed during the late 1950s, with construction and commissioning phases carried out during the early 1960s. The major facilities in the reprocessing route, housed in separate buildings, are as follows: pond storage, fuel decanning plant, chemical separation plant, uranium finishing, plutonium finishing, effluent treatment plants. The plants have operated successfully since the commissioning phase, with reprocessing rates of some 1,000 to 1,600 tons of uranium per year. The paper describes on-line refurbishment, concentrating on the following aspects: (1) selection of new equipment for installation in an existing chemical plant; (2) installation of new plant and equipment in an operating plant with minimum loss of production while meeting onerous new and significant safety requirements; (3) upgrading of an operating plant to meet new and more demanding criteria for radiological protection; and (4) establishments of the best approach to decommissioning and removal or redundant equipment within an operating plant.

  3. CoxFe1-x oxide coatings on metallic interconnects for solid oxide fuel cells

    NASA Astrophysics Data System (ADS)

    Shen, Fengyu; Lu, Kathy

    2016-10-01

    In order to improve the performance of Cr-containing steel as an interconnect material for solid oxide fuel cells, CoFe alloy coatings with Co:Fe ratios of 9:1, 8:2, 7:3, 6:4, and 5:5 are deposited by electrodeposition and then oxidized to CoxFe1-x oxide coatings with a thickness of ∼6 μm as protective layers on the interconnect. The area specific resistance of the coated interconnect increases with the Fe content. Higher Co content oxide coatings are more effective in limiting the growth of the chromia scale while all coatings are effective in inhibiting Cr diffusion and evaporation. With the Co0.8Fe0.2 oxide coated interconnect, the electrochemical performance of the Sm0.5Sr0.5Co0.2Fe0.8O3 cathode is improved. Only 1.54 atomic percentage of Cr is detected on the surface of the Sm0.5Sr0.5Co0.2Fe0.8O3 cathode while no Cr is detected 0.66 μm or more into the cathode. CoxFe1-x oxide coatings are promising candidates for solid oxide fuel cell interconnects with the advantage of using existing cathode species for compatibility and performance enhancement.

  4. A low-Cr metallic interconnect for intermediate-temperature solid oxide fuel cells

    SciTech Connect

    Geng, Shujiang; Zhu, Jiahong; Brady, Michael P; Anderson, Harlan; ZHOU, XIADONG; YANG, ZHENGUO

    2007-01-01

    Solid oxide fuel cells (SOFCs) have attracted significant attention due to the potential for environmentally-friendly power generation with high efficiency, fuel flexibility, and zero/no emissions. However, the main hurdles thwarting the commercial introduction of SOFCs are the stack cost and durability, particularly related to the long-term stability of stack/cell materials such as the interconnect 1-3. There has been recent interest in utilizing the Cr2O3-forming alloys as interconnect for intermediate-temperature SOFCs4-6. As a consequence, volatile Cr species from the Cr2O3 scale can cause severe degradation of electrical and catalytic properties of the cathode7-9. Here, we report a new low-Cr Fe-Co-Ni base alloy that demonstrates a close match in coefficient of thermal expansion (CTE) with adjacent cell components; good oxidation resistance; and low oxide scale area specific resistance (ASR). The formation of a Cr-free (Fe,Co,Ni)3O4 spinel outer layer over the chromia inner layer upon thermal exposure effectively reduces the chromium evaporation.

  5. First Principles and Genetic Algorithm Studies of Lanthanide Metal Oxides for Optimal Fuel Cell Electrolyte Design

    NASA Astrophysics Data System (ADS)

    Ismail, Arif

    As the demand for clean and renewable energy sources continues to grow, much attention has been given to solid oxide fuel cells (SOFCs) due to their efficiency and low operating temperature. However, the components of SOFCs must still be improved before commercialization can be reached. Of particular interest is the solid electrolyte, which conducts oxygen ions from the cathode to the anode. Samarium-doped ceria (SDC) is the electrolyte of choice in most SOFCs today, due mostly to its high ionic conductivity at low temperatures. However, the underlying principles that contribute to high ionic conductivity in doped ceria remain unknown, and so it is difficult to improve upon the design of SOFCs. This thesis focuses on identifying the atomistic interactions in SDC which contribute to its favourable performance in the fuel cell. Unfortunately, information as basic as the structure of SDC has not yet been found due to the difficulty in experimentally characterizing and computationally modelling the system. For instance, to evaluate 10.3% SDC, which is close to the 11.1% concentration used in fuel cells, one must investigate 194 trillion configurations, due to the numerous ways of arranging the Sm ions and oxygen vacancies in the simulation cell. As an exhaustive search method is clearly unfeasible, we develop a genetic algorithm (GA) to search the vast potential energy surface for the low-energy configurations, which will be most prevalent in the real material. With the GA, we investigate the structure of SDC for the first time at the DFT+U level of theory. Importantly, we find key differences in our results from prior calculations of this system which used less accurate methods, which demonstrate the importance of accurately modelling the system. Overall, our simulation results of the structure of SDC agree with experimental measurements. We identify the structural significance of defects in the doped ceria lattice which contribute to oxygen ion conductivity. Thus

  6. Elucidating the mechanism of Cr(VI) formation upon the interaction with metal oxides during coal oxy-fuel combustion.

    PubMed

    Chen, Juan; Jiao, Facun; Zhang, Lian; Yao, Hong; Ninomiya, Yoshihiko

    2013-10-15

    The thermodynamics underpinning the interaction of Cr-bearing species with basic metal oxides, i.e. K2O, Fe2O3, MgO and CaO, during the air and oxy-fuel combustion of coal have been examined. The synchrotron-based X-ray adsorption near-edge spectroscopy (XANES) was used for Cr speciation. For the oxides tested, Cr(VI) formation is dominated by the reduction potential of the metals. The oxides of Ca(2+) with high reduction potential favored the oxidation of Cr(III), same for K(+). The other two basic metals, Fe2O3 and MgO with lower reduction potentials reacted with Cr(III) to form the corresponding chromites at the temperatures above 600°C. Coal combustion experiments in drop-tube furnace have confirmed the rapid capture of Cr vapors, either trivalent or hexavalent, by CaO into solid ash. The existence of HCl in flue gas favored the vaporization of Cr as CrO2Cl2, which was in turn captured by CaO into chromate. Both Fe2O3 and MgO exhibited less capability on scavenging the Cr(VI) vapor. Particularly, MgO alone exhibited a low capability for capturing the vaporized Cr(III) vapors. However, its co-existence with CaO in the furnace inhibited the Cr(VI) formation. This is beneficial for minimizing the toxicity of Cr in the coal combustion-derived fly ash.

  7. Complex Metal Hydrides. High Energy Fuel Components for Solid Propellant Rocket Motors.

    DTIC Science & Technology

    of beryllium-hydrogen chemistry (2) a study of the redistribution of AlH3 -BeCl2, BeH2-BeCl2 and AlH3 -AlCl3 in ether solvent (3) a study of the...formation and properties of ether soluble AlH3 (4) a study involving the preparation of a series of complex metal hydrides of zinc (e.g., Li2ZnH4) (5) a

  8. Field Method for Detection of Metal Deactivator Additive in Jet Fuel

    DTIC Science & Technology

    2009-04-01

    5 2.2.2 Metal salt doping of stationary phase .................................................. 6 2.2.3 DSTO open column ...didn’t require the use of portable spectrophotometers, solvents or reagents. The method chosen was based on open column chromatography using a small... column of silica gel that was coated with a copper salt. The indicator for the presence of MDA is a colour change in the silica gel. The copper salt

  9. Energy Efficiency Handbook for Driver's Education.

    ERIC Educational Resources Information Center

    Berlowitz, Dan; And Others

    Presented are suggestions to help the automobile driver attain the saving of fuel and money. Discussed are starting and stopping; anticipation of traffic conditions; use of accessories; trip planning; and accomodation of pedestrians and cyclists. Additional topics covered include systematic car maintenance and safety considerations. (RE)

  10. AB INITIO STUDY OF ADVANCED METALLIC NUCLEAR FUELS FOR FAST BREEDER REACTORS

    SciTech Connect

    Landa, A; Soderlind, P; Grabowski, B; Turchi, P A; Ruban, A V; Vitos, L

    2012-04-23

    Density-functional formalism is applied to study the ground state properties of {gamma}-U-Zr and {gamma}-U-Mo solid solutions. Calculated heats of formation are compared with CALPHAD assessments. We discuss how the heat of formation in both alloys correlates with the charge transfer between the alloy components. The decomposition curves for {gamma}-based U-Zr and U-Mo solid solutions are derived from Ising-type Monte Carlo simulations. We explore the idea of stabilization of the {delta}-UZr{sub 2} compound against the {alpha}-Zr (hcp) structure due to increase of Zr d-band occupancy by the addition of U to Zr. We discuss how the specific behavior of the electronic density of states in the vicinity of the Fermi level promotes the stabilization of the U{sub 2}Mo compound. The mechanism of possible Am redistribution in the U-Zr and U-Mo fuels is also discussed.

  11. Metal-ceramic/ceramic nanostructured layered composites for solid oxide fuel cells by spark plasma sintering.

    PubMed

    Bezdorozhev, Oleksii; Borodianska, Hanna; Sakka, Yoshio; Vasylkiv, Oleg

    2014-06-01

    In this work, bi-layered Fe-Ni-Co-YSZ/YSZ nanostructured composites for solid oxide fuel cells were obtained using the spark plasma sintering (SPS) technique. The microstructures of the anode and electrolyte were controlled by optimization of SPS consolidation parameters. The resulting bilayers have a full dense YSZ electrolyte and porous Fe-Ni-Co/YSZ anode as well as crack-free and well-bonded anode/electrolyte interface. On the other hand, SPS under non-optimized processing parameters cannot yield the desired results. The high resistance to thermal stresses of the fabricated half-cells was achieved with Fe-Ni-Co/YSZ anode. The developed anode showed higher thermal compatibility with YSZ electrolyte than usual Ni/YSZ cermet. Thus, with the successful combination of SPS parameters and anode material, we have obtained bi-layers for SOFCs with required microstructure and thermal compatibility.

  12. Effect of indium addition in U-Zr metallic fuel on lanthanide migration

    NASA Astrophysics Data System (ADS)

    Kim, Yeon Soo; Wiencek, T.; O'Hare, E.; Fortner, J.; Wright, A.; Cheon, J. S.; Lee, B. O.

    2017-02-01

    Advanced fast reactor concepts to achieve ultra-high burnup (∼50%) require prevention of fuel-cladding chemical interaction (FCCI). Fission product lanthanide accumulation at high burnup is substantial and significantly contributes to FCCI upon migration to the cladding interface. Diffusion barriers are typically used to prevent interaction of the lanthanides with the cladding. A more active method has been proposed which immobilizes the lanthanides through formation of stable compounds with an additive. Theoretical analysis showed that indium, thallium, and antimony are good candidates. Indium was the strongest candidate because of its low reactivity with iron-based cladding alloys. Characterization of the as-fabricated alloys was performed to determine the effectiveness of the indium addition in forming compounds with lanthanides, represented by cerium. Tests to examine how effectively the dopant prevents lanthanide migration under a thermal gradient were also performed. The results showed that indium effectively prevented cerium migration.

  13. Selective deposition of Pt onto supported metal clusters for fuel cell electrocatalysts

    NASA Astrophysics Data System (ADS)

    Jeon, Tae-Yeol; Pinna, Nicola; Yoo, Sung Jong; Ahn, Docheon; Choi, Sun Hee; Willinger, Marc-Georg; Cho, Yong-Hun; Lee, Kug-Seung; Park, Hee-Young; Yu, Seung-Ho; Sung, Yung-Eun

    2012-09-01

    We report a new method for deposition of Pt on a metal core to develop real electrocatalysts with significantly reduced amounts of expensive Pt as well as enhanced activity for oxygen reduction reaction. Ru and Pd have different crystal structures and modify the electronic structure of Pt to a different extent (shifts in d-band center). They were chosen as core materials to examine whether hydroquinone dissolved in ethanol can be used to deposit additional Pt atoms onto preformed core nanoparticles, and whether the modified d-character of Pt on different host metals can result in the enhanced ORR activity. The physicochemical characteristics of Pd-Pt and Ru-Pt core-shell nanoparticles are investigated. The core-shell structure was identified through a combination of experimental methods, employing electron microscopy, electrochemical measurements, and synchrotron X-ray measurements such as powder X-ray diffraction, X-ray absorption fine structure, and X-ray photoelectron spectroscopy. The hydroquinone reduction method proved to be an excellent route for the epitaxial growth of a Pt shell on the metal cores, leading to enhanced ORR activities.We report a new method for deposition of Pt on a metal core to develop real electrocatalysts with significantly reduced amounts of expensive Pt as well as enhanced activity for oxygen reduction reaction. Ru and Pd have different crystal structures and modify the electronic structure of Pt to a different extent (shifts in d-band center). They were chosen as core materials to examine whether hydroquinone dissolved in ethanol can be used to deposit additional Pt atoms onto preformed core nanoparticles, and whether the modified d-character of Pt on different host metals can result in the enhanced ORR activity. The physicochemical characteristics of Pd-Pt and Ru-Pt core-shell nanoparticles are investigated. The core-shell structure was identified through a combination of experimental methods, employing electron microscopy

  14. Soda-fuel metallurgy: Metal ions for carbon neutral CO2 and H2O reduction

    NASA Astrophysics Data System (ADS)

    Neelameggham, Neale R.

    2009-04-01

    The role of minerals in biomass formation is understood only to a limited extent. When the term “photosynthesis—CO2 and H2O reduction of sugars, using solar energy”—is used, one normally thinks of chlorophyll as a compound containing magnesium. Alkali and alkaline earth metals present in leaf cells in the form of ions are equally essential in this solar energy bioconversion coupled with nitrogen fixation. Application of some of these principles can lead to artificial carbon-neutral processes on an industrial scale close to the concentrated CO2 emission sources.

  15. Complex Metal Hydrides. High Energy Fuel Components for Solid Propellant Rocket Motors

    DTIC Science & Technology

    1978-08-01

    8217"’:"•&. \\ ’•=..ap ’.,’ ,, PUBLICATIONS AS A RESULT OF WORK ON THIS PROJECT 1. E. C. Ashby and B. James, "Concerning the Direct Synthesis of the Alkali...Direct Synthesis of Alinoalanes," Or ano- metal. Chen.,22, C34 (1970). 7. E. C. Ashby and R. G. Beach, "Concerning the Reaction of Lithium AluminumHydride...with Diethyl Magnesium in Diethyl Ether," Inorg. Chem., 9, 2301., (1970). ’’ -" 8. R. A, Kovar and E. C. Ashby, "Aminoalanes. Direct Synthesis from

  16. Implementation, verification, and validation of the FPIN2 metal fuel pin mechanics model in the SASSYS/SAS4A LMR transient analysis codes

    SciTech Connect

    Sofu, T.; Kramer, J.M.

    1994-03-01

    The metal fuel version of the FPIN2 code which provides a validated pin mechanics model is coupled with SASSYS/SAS4A Version 3.0 for single pin calculations. In this implementation, SASSY/SAS4A provides pin temperatures, and FPIN2 performs analysis of pin deformation and predicts the time and location of cladding failure. FPIN2 results are also used for the estimates of axial expansion of fuel and associated reactivity effects. The revalidation of the integrated SAS-FPIN2 code system is performed using TREAT tests.

  17. High Performance Ceramic Interconnect Material for Solid Oxide Fuel Cells (SOFCs): Ca- and Transition Metal-doped Yttrium Chromite

    SciTech Connect

    Yoon, Kyung J.; Stevenson, Jeffry W.; Marina, Olga A.

    2011-10-15

    The effect of transition metal substitution on thermal and electrical properties of Ca-doped yttrium chromite was investigated in relation to use as a ceramic interconnect in high temperature solid oxide fuel cells (SOFCs). 10 at% Co, 4 at% Ni, and 1 at% Cu substitution on B-site of 20 at% Ca-doped yttrium chromite led to a close match of thermal expansion coefficient (TEC) with that of 8 mol% yttria-stabilized zirconia (YSZ), and a single phase Y0.8Ca0.2Cr0.85Co0.1Ni0.04Cu0.01O3 remained stable between 25 and 1100 degree C over a wide oxygen partial pressure range. Doping with Cu significantly facilitated densification of yttrium chromite. Ni dopant improved both electrical conductivity and dimensional stability in reducing environments, likely through diminishing the oxygen vacancy formation. Substitution with Co substantially enhanced electrical conductivity in oxidizing atmosphere, which was attributed to an increase in charge carrier density and hopping mobility. Electrical conductivity of Y0.8Ca0.2Cr0.85Co0.1Ni0.04Cu0.01O3 at 900 degree C is 57 S/cm in air and 11 S/cm in fuel (pO2=5×10^-17 atm) environments. Chemical compatibility of doped yttrium chromite with other cell components was verified at the processing temperatures. Based on the chemical and dimensional stability, sinterability, and thermal and electrical properties, Y0.8Ca0.2Cr0.85Co0.1Ni0.04Cu0.01O3 is suggested as a promising SOFC ceramic interconnect to potentially overcome technical limitations of conventional acceptor-doped lanthanum chromites.

  18. Supported noble metals on hydrogen-treated TiO2 nanotube arrays as highly ordered electrodes for fuel cells.

    PubMed

    Zhang, Changkun; Yu, Hongmei; Li, Yongkun; Gao, Yuan; Zhao, Yun; Song, Wei; Shao, Zhigang; Yi, Baolian

    2013-04-01

    Hydrogen-treated TiO2 nanotube (H-TNT) arrays serve as highly ordered nanostructured electrode supports, which are able to significantly improve the electrochemical performance and durability of fuel cells. The electrical conductivity of H-TNTs increases by approximately one order of magnitude in comparison to air-treated TNTs. The increase in the number of oxygen vacancies and hydroxyl groups on the H-TNTs help to anchor a greater number of Pt atoms during Pt electrodeposition. The H-TNTs are pretreated by using a successive ion adsorption and reaction (SIAR) method that enhances the loading and dispersion of Pt catalysts when electrodeposited. In the SIAR method a Pd activator can be used to provide uniform nucleation sites for Pt and leads to increased Pt loading on the H-TNTs. Furthermore, fabricated Pt nanoparticles with a diameter of 3.4 nm are located uniformly around the pretreated H-TNT support. The as-prepared and highly ordered electrodes exhibit excellent stability during accelerated durability tests, particularly for the H-TNT-loaded Pt catalysts that have been annealed in ultrahigh purity H2 for a second time. There is minimal decrease in the electrochemical surface area of the as-prepared electrode after 1000 cycles compared to a 68 % decrease for the commercial JM 20 % Pt/C electrode after 800 cycles. X-ray photoelectron spectroscopy shows that after the H-TNT-loaded Pt catalysts are annealed in H2 for the second time, the strong metal-support interaction between the H-TNTs and the Pt catalysts enhances the electrochemical stability of the electrodes. Fuel-cell testing shows that the power density reaches a maximum of 500 mWcm(-2) when this highly ordered electrode is used as the anode. When used as the cathode in a fuel cell with extra-low Pt loading, the new electrode generates a specific power density of 2.68 kWg(Pt) (-1) . It is indicated that H-TNT arrays, which have highly ordered nanostructures, could be used as ordered electrode supports

  19. EQ6 Calculations for Chemical Degradation Of N Reactor (U-Metal) Spent Nuclear Fuel Waste Packages

    SciTech Connect

    P. Bernot

    2001-02-27

    The Monitored Geologic Repository (MGR) Waste Package Department of the Civilian Radioactive Waste Management System Management & Operating Contractor (CRWMS M&O) performed calculations to provide input for disposal of spent nuclear fuel (SNF) from the N Reactor, a graphite moderated reactor at the Department of Energy's (DOE) Hanford Site (ref. 1). The N Reactor core was fueled with slightly enriched (0.947 wt% and 0.947 to 1.25 wt% {sup 235}U in Mark IV and Mark IA fuels, respectively) U-metal clad in Zircaloy-2 (Ref. 1, Sec. 3). Both types of N Reactor SNF have been considered for disposal at the proposed Yucca Mountain site. For some WPs, the outer shell and inner shell may breach (Ref. 3) allowing the influx of water. Water in the WP will moderate neutrons, increasing the likelihood of a criticality event within the WP; and the water may, in time, gradually leach the fissile components from the WP, further affecting the neutronics of the system. This study presents calculations of the long-term geochemical behavior of WPs containing two multi-canister overpacks (MCO) with either six baskets of Mark IA or five baskets of Mark IV intact N Reactor SNF rods (Ref. 1, Sec. 4) and two high-level waste (HLW) glass pour canisters (GPCs) arranged according to the codisposal concept (Ref. 4). The specific study objectives were to determine: (1) The extent to which fissile uranium will remain in the WP after corrosion/dissolution of the initial WP configuration (2) The extent to which fissile uranium will be carried out of the degraded WP by infiltrating water (such that internal criticality is no longer possible, but the possibility of external criticality may be enhanced); and (3) The nominal chemical composition for the criticality evaluations of the WP design, and to suggest the range of parametric variations for additional evaluations. The scope of this calculation, the chemical compositions (and subsequent criticality evaluations) of the simulations, is limited to

  20. Formation mechanism of gas bubble superlattice in UMo metal fuels: Phase-field modeling investigation

    NASA Astrophysics Data System (ADS)

    Hu, Shenyang; Burkes, Douglas E.; Lavender, Curt A.; Senor, David J.; Setyawan, Wahyu; Xu, Zhijie

    2016-10-01

    Nano-gas bubble superlattices are often observed in irradiated UMo nuclear fuels. However, the formation mechanism of gas bubble superlattices is not well understood. A number of physical processes may affect the gas bubble nucleation and growth; hence, the morphology of gas bubble microstructures including size and spatial distributions. In this work, a phase-field model integrating a first-passage Monte Carlo method to investigate the formation mechanism of gas bubble superlattices was developed. Six physical processes are taken into account in the model: 1) heterogeneous generation of gas atoms, vacancies, and interstitials informed from atomistic simulations; 2) one-dimensional (1-D) migration of interstitials; 3) irradiation-induced dissolution of gas atoms; 4) recombination between vacancies and interstitials; 5) elastic interaction; and 6) heterogeneous nucleation of gas bubbles. We found that the elastic interaction doesn't cause the gas bubble alignment, and fast 1-D migration of interstitials along <110> directions in the body-centered cubic U matrix causes the gas bubble alignment along <110> directions. It implies that 1-D interstitial migration along [110] direction should be the primary mechanism of a fcc gas bubble superlattice which is observed in bcc UMo alloys. Simulations also show that fission rates, saturated gas concentration, and elastic interaction all affect the morphology of gas bubble microstructures.

  1. Residual stresses in high-velocity oxy-fuel metallic coatings

    NASA Astrophysics Data System (ADS)

    Totemeier, T. C.; Wright, R. N.; Swank, W. D.

    2004-06-01

    X-ray based residual stress measurements were made on type 316 stainless steel and Fe3Al coatings that were high-velocity oxy-fuel (HVOF) sprayed onto low-carbon and stainless steel substrates. Nominal coating thicknesses varied from 250 to 1500 µm. The effect of HVOF spray particle velocity on residual stress and deposition efficiency was assessed by preparing coatings at three different torch chamber pressures. The effect of substrate thickness on residual stress was determined by spraying coatings onto thick (6.4 mm) and thin (1.4 mm) substrates. Residual stresses were compressive for both coating materials and increased in magnitude with spray velocity. For coatings applied to thick substrates, near-surface residual stresses were essentially constant with increasing coating thickness. Differences in thermal expansion coefficient between low-carbon and stainless steels led to a 180 MPa difference in residual stress for Fe3Al coatings. Deposition efficiency for both materials is maximized at an intermediate (˜600 m/s) velocity. Considerations for X-ray measurement of residual stresses in HVOF coatings are also presented.

  2. Formation mechanism of gas bubble superlattice in UMo metal fuels: Phase-field modeling investigation

    SciTech Connect

    Hu, Shenyang; Burkes, Douglas E.; Lavender, Curt A.; Senor, David J.; Setyawan, Wahyu; Xu, Zhijie

    2016-07-08

    Nano-gas bubble superlattices are often observed in irradiated UMo nuclear fuels. However, the for- mation mechanism of gas bubble superlattices is not well understood. A number of physical processes may affect the gas bubble nucleation and growth; hence, the morphology of gas bubble microstructures including size and spatial distributions. In this work, a phase-field model integrating a first-passage Monte Carlo method to investigate the formation mechanism of gas bubble superlattices was devel- oped. Six physical processes are taken into account in the model: 1) heterogeneous generation of gas atoms, vacancies, and interstitials informed from atomistic simulations; 2) one-dimensional (1-D) migration of interstitials; 3) irradiation-induced dissolution of gas atoms; 4) recombination between vacancies and interstitials; 5) elastic interaction; and 6) heterogeneous nucleation of gas bubbles. We found that the elastic interaction doesn’t cause the gas bubble alignment, and fast 1-D migration of interstitials along $\\langle$110$\\rangle$ directions in the body-centered cubic U matrix causes the gas bubble alignment along $\\langle$110$\\rangle$ directions. It implies that 1-D interstitial migration along [110] direction should be the primary mechanism of a fcc gas bubble superlattice which is observed in bcc UMo alloys. Simulations also show that fission rates, saturated gas concentration, and elastic interaction all affect the morphology of gas bubble microstructures.

  3. Elevated pCO2 effects on the geochemistry of carbonate aquifers: calcite dissolution as a driver of elevated metal concentrations

    NASA Astrophysics Data System (ADS)

    Wunsch, A.; Navarre-Sitchler, A. K.; Moore, J.; McCray, J. E.

    2012-12-01

    Geological carbon capture, utilization and storage has gained momentum in the last decade as a viable option of reducing anthropogenic emissions of CO2, with several demonstration projects completed, in progress or planned for upcoming years. However, large-scale CO2-injection operations are accompanied by concerns of CO2 leakage from deep geological repositories and subsequent contact with shallower aquifers, such as underground sources of drinking water. Direct toxicity of CO2 is of lesser concern; rather, it is the acidification of aquifers from increased CO2 partial-pressures (pCO2), which may lead to release of metals into groundwater through mineral dissolution and metal desorption. Previous geochemical studies have suggested that the presence of calcite in aquifer material would reduce the hazard of metal release by effectively buffering acidity via calcite dissolution at elevated pCO2, thus placing carbonate aquifers at lesser risk in case of CO2 leakage. Yet calcite is rarely found in pure form, and often contains a wide range of impurities, including metals such as As, Cr, and Pb, in solid-solution. Dissolution of calcite during acidity buffering is accompanied by release of these impurities from the calcite lattice. We show through experimental work that dissolution of calcite is the primary mechanism responsible for elevated concentrations of metals in carbonate aquifers at high pCO2. It is also evident that the mechanism responsible for metal release, i.e. dissolution or desorption, is metal-specific and pCO2-specific. Modeling work based on our experimental results suggests that in reducing aquifers calcite can contribute more to release of metals than sulfides, which are generally viewed as likely sources of metals in aquifers, during a hypothetical 30-year CO2 leak. In addition, modeling work suggests that when sulfide minerals are present in a carbonate aquifer, metals release would be more sensitive to pO2 than to pCO2.

  4. Driver Behavior and Motivation.

    ERIC Educational Resources Information Center

    Thomas, Patricia

    School bus driver behavior and motivation are continuing concerns for leaders/administrators in the field of transportation. Motivation begins with selection of a potential new driver. Drivers must like children and be patient, loyal, and punctual. The applicant's background must be verified, in view of the national concern for child safety.…

  5. Studies on metal catalysts and carbon materials for fuel cell applications

    NASA Astrophysics Data System (ADS)

    Zhang, Gaixia

    As a potential candidate for an environmentally benign and highly efficient electric power generation technology, proton exchange membrane fuel cells (PEMFC) are now attracting great interest for various applications. The main objective of this project has been to investigate the interfacial interaction of Pt nanoparticles with their carbon supports, so as to determine ways to optimise the catalyst electrode and to increase its catalytic activity, thereby enhancing PEM fuel cell performance. We first studied the interfacial interaction (leading to adhesion) of Pt nanoparticles evaporated onto untreated and Ar+-treated highly oriented pyrolytic graphite surfaces, with, respectively, low and high surface defect densities; HOPG was used as a model for carbon nanotubes (CNTs) and carbon fibers. We found that those Pt nanoparticles have very weak interactions with their pristine carbon material supports, with no evidence of compound formation between them. Our analysis, however, indicated that the adhesion of Pt nanoparticles to their supports can be enhanced, using ion beams, plasmas, or other treatments to establish defects on the carbon substrate surface. In addition, by using multicomponent XPS analysis with symmetric lineshapes for each Pt4f spectral component (4f7/2,5/2), we attributed the component peaks to the existence of (i) surface oxidation on the platinum nanoparticles, and different electronic configurations of (ii) surface and (iii) bulk Pt atoms. One way of enhancing strong adhesion between them is by chemical functionalization of the support. Using mixed H2SO4/HNO3 acid treatments, we have characterized the surface chemistry of functionalized carbon fiber paper by combining infrared, Raman and X-ray photoelectron spectroscopies, to give new insights into the often-used oxidation of graphene-containing materials. We have, for the first time, demonstrated the presence of transient O-, N- and S-containing species during the oxidation process, as well as

  6. Theory-guided design of nanoscale multi-metallic catalysts for fuel cells

    SciTech Connect

    Balbuena, Perla B; Seminario, Jorge M

    2007-04-30

    Research goals This project aims to address the following aspects of the oxygen reduction reaction on multimetallic nanocatalysts: 1. Elucidate physical and chemical aspects of electron and proton transfer 2. Incorporate local and nonlocal field effects to the analysis 3. Investigate the performance of bimetallic and multimetallic nanocatalytic ensembles a. Explore combinations of Pt with other non-precious metals b. Explore theoretically the performance of active catalytic sites/substrate/proton-carrier systems towards maximizing oxygen reduction currents. c. Explore compatibility catalyst/substrate/ionic carrier. 4. Investigate nanocatalyst stability under the reaction conditions, effects of pH and overall composition; surface segregation phenomena in nanoclusters. 5. Carry out theory-guided experiments involving electron transfer as proof of concept. Specific objectives for the previous year: Determine trends for catalytic activity towards the oxygen reduction reaction and stability against dissolution of Pt-based alloy nanocatalysts exposed to acid medium. Reactivity and stability trends are sought as a function of surface composition and atomic distribution in the first 2-3 surface layers. Investigate possible mechanisms for metal dissolution. Developing and testing new computational approaches to characterize the catalytic interface. Significant achievements and results for the previous year: Catalytic activity: Variations in atomic distribution (mixed vs. ordered structures) analyzed in small clusters and extended surfaces of PtxPdy at fixed overall composition revealed polarization effects caused by specific electronic density distributions determining trends in reactivity. We studied other bimetallic and trimetallic systems to characterize the ability of various alloy elements for modifying Pt reactivity. We found an interesting parallelism between metalloenzymes and bimetallic nanocatalysts for the oxygen reduction reaction. Along the same lines, we are

  7. LANL GPIB Driver

    SciTech Connect

    2004-04-15

    This driver code adds a GPIB infrastructure and API features to 2.6 series Linux kernels. Currently supported hardware is National Instruments PCI-GPIB cards built on either the TNT4882 controller chip, or the TNT5004 controller chip. This driver is an improvement over previous GPIB drivers in Linux because it has all the features of the GPL, high performance DMA, supports Linux 2.6 and the new driver model, and has a cleaner API than the previous drivers. GPIB is the "general purpose interface bus", commonly used to control oscilloscopes, digital multimeters, function generators, and other electronic test equipment.

  8. Conceptual design study on very small long-life gas cooled fast reactor using metallic natural Uranium-Zr as fuel cycle input

    SciTech Connect

    Monado, Fiber; Ariani, Menik; Su'ud, Zaki; Waris, Abdul; Basar, Khairul; Permana, Sidik; Aziz, Ferhat; Sekimoto, Hiroshi

    2014-02-12

    A conceptual design study of very small 350 MWth Gas-cooled Fast Reactors with Helium coolant has been performed. In this study Modified CANDLE burn-up scheme was implemented to create small and long life fast reactors with natural Uranium as fuel cycle input. Such system can utilize natural Uranium resources efficiently without the necessity of enrichment plant or reprocessing plant. The core with metallic fuel based was subdivided into 10 regions with the same volume. The fresh Natural Uranium is initially put in region-1, after one cycle of 10 years of burn-up it is shifted to region-2 and the each region-1 is filled by fresh Natural Uranium fuel. This concept is basically applied to all axial regions. The reactor discharge burn-up is 31.8% HM. From the neutronic point of view, this design is in compliance with good performance.

  9. Conceptual design study on very small long-life gas cooled fast reactor using metallic natural Uranium-Zr as fuel cycle input

    NASA Astrophysics Data System (ADS)

    Monado, Fiber; Ariani, Menik; Su'ud, Zaki; Waris, Abdul; Basar, Khairul; Aziz, Ferhat; Permana, Sidik; Sekimoto, Hiroshi

    2014-02-01

    A conceptual design study of very small 350 MWth Gas-cooled Fast Reactors with Helium coolant has been performed. In this study Modified CANDLE burn-up scheme was implemented to create small and long life fast reactors with natural Uranium as fuel cycle input. Such system can utilize natural Uranium resources efficiently without the necessity of enrichment plant or reprocessing plant. The core with metallic fuel based was subdivided into 10 regions with the same volume. The fresh Natural Uranium is initially put in region-1, after one cycle of 10 years of burn-up it is shifted to region-2 and the each region-1 is filled by fresh Natural Uranium fuel. This concept is basically applied to all axial regions. The reactor discharge burn-up is 31.8% HM. From the neutronic point of view, this design is in compliance with good performance.

  10. Trace heavy metal ions promoted extracellular electron transfer and power generation by Shewanella in microbial fuel cells.

    PubMed

    Xu, Yu-Shang; Zheng, Tao; Yong, Xiao-Yu; Zhai, Dan-Dan; Si, Rong-Wei; Li, Bing; Yu, Yang-Yang; Yong, Yang-Chun

    2016-07-01

    Although microbial fuel cells (MFCs) is considered as one of the most promising technology for renewable energy harvesting, low power output still accounts one of the bottlenecks and limits its further development. In this work, it is found that Cu(2+) (0.1μgL(-1)-0.1mgL(-1)) or Cd(2+) (0.1μgL(-1)-1mgL(-1)) significantly improve the electricity generation in MFCs. The maximum power output achieved with trace level of Cu(2+) (∼6nM) or Cd(2+) (∼5nM) is 1.3 times and 1.6 times higher than that of the control, respectively. Further analysis verifies that addition of Cu(2+) or Cd(2+) effectively improves riboflavin production and bacteria attachment on the electrode, which enhances bacterial extracellular electron transfer (EET) in MFCs. These results unveil the mechanism for power output enhancement by Cu(2+) or Cd(2+) addition, and suggest that metal ion addition should be a promising strategy to enhance EET as well as power generation of MFCs.

  11. New insights into non-precious metal catalyst layer designs for proton exchange membrane fuel cells: Improving performance and stability

    NASA Astrophysics Data System (ADS)

    Banham, Dustin; Kishimoto, Takeaki; Sato, Tetsutaro; Kobayashi, Yoshikazu; Narizuka, Kumi; Ozaki, Jun-ichi; Zhou, Yingjie; Marquez, Emil; Bai, Kyoung; Ye, Siyu

    2017-03-01

    The activity of non-precious metal catalysts (NPMCs) has now reached a stage at which they can be considered as possible alternatives to Pt for some proton exchange membrane fuel cell (PEMFC) applications. However, despite significant efforts over the past 50 years on catalyst development, only limited studies have been performed on NPMC-based cathode catalyst layer (CCL) designs. In this work, an extensive ionomer study is performed to investigate the impact of ionomer equivalent weight on performance, which has uncovered two crucial findings. Firstly, it is demonstrated that beyond a critical CCL conductance, no further improvement in performance is observed. The procedure used to determine this critical conductance can be used by other researchers in this field to aid in their design of high performing NPMC-based CCLs. Secondly, it is shown that the stability of NPMC-based CCLs can be improved through the use of low equivalent weight ionomers. This represents a completely unexplored pathway for further stability improvements, and also provides new insights into the possible degradation mechanisms occurring in NPMC-based CCLs. These findings have broad implications on all future NPMC-based CCL designs.

  12. Effective adsorptive removal of indole from model fuel using a metal-organic framework functionalized with amino groups.

    PubMed

    Ahmed, Imteaz; Jhung, Sung Hwa

    2015-01-01

    Nitrogen-containing compounds (NCCs) should be removed from fuels because of the negative effect of NCCs on the environment and catalyst stability. NCCs are composed of basic materials such as quinoline (QUI) and neutral materials such as indole (IND). The NCCs can be removed by various methods including adsorption. Compared with basic NCCs, neutral NCCs are more difficult to remove through adsorption due to their less affinity toward adsorbents. In this report, adsorption of IND (as one of the representative neutral NCCs) was studied over the metal-organic frameworks (MOFs), UiO-66 and UiO-66-NH2, which contain terephthalate and aminoterephthalate linkers, respectively. In spite of the reduced porosity of UiO-66-NH2, the adsorption capacity of IND was improved upto 46% when compared with pristine UiO-66. Therefore, the additional amino group in the MOF imparts extra adsorption capability on the MOF. For a detailed investigation, adsorption of other NCCs such as QUI, pyrrole, and methylpyrrole was studied. The improved adsorption of IND over amino-functionalized MOFs could be attributed to the improved interaction of IND with the MOF via H-bonding because of the NH2 group. In addition to this remarkable improvement in IND adsorption, UiO-66-NH2 could be regenerated several times for the adsorption of IND by simple solvent washing.

  13. Gaseous fuel production from nonrecyclable paper wastes by using supported metal catalysts in high-temperature liquid water.

    PubMed

    Yamaguchi, Aritomo; Hiyoshi, Norihito; Sato, Osamu; Bando, Kyoko K; Shirai, Masayuki

    2010-06-21

    Paper wastes are used for the production of gaseous fuels over supported metal catalysts. The gasification of the nonrecyclable paper wastes, such as shredded documents and paper sludge, is carried out in high-temperature liquid water. The order of the catalytic activity for the gasification is found to be ruthenium>rhodium>platinum>palladium. A charcoal-supported ruthenium catalyst (Ru/C) is the most effective for the gasification of paper and cellulose. Paper wastes are gasified to a limited degree (32.6 carbon %) for 30 min in water at 523 K to produce methane and carbon dioxide, with a small amount of hydrogen. At 573 K, more complete gasification with almost 100 carbon % is achieved within 10 min in water. At 523 K, the gas yield of paper gasification over Ru/C is higher than that of cellulose powder. The gas yields are increased by ball-milling treatment of the recycled paper and cellulose powder. Printed paper wastes are also gasified at 523 K in water.

  14. A facile synthetic strategy for iron, aniline-based non-precious metal catalysts for polymer electrolyte membrane fuel cells.

    PubMed

    Lee, Hyunjoon; Kim, Min Jeong; Lim, Taeho; Sung, Yung-Eun; Kim, Hyun-Jong; Lee, Ho-Nyun; Kwon, Oh Joong; Cho, Yong-Hun

    2017-07-14

    The development of a low cost and highly active alternative to the commercial Pt/C catalysts used in the oxygen reduction reaction (ORR) requires a facile and environmentally-friendly synthesis process to facilitate large-scale production and provide an effective replacement. Transition metals, in conjunction with nitrogen-doped carbon, are among the most promising substitute catalysts because of their high activity, inexpensive composition, and high carbon monoxide tolerance. We prepared a polyaniline-derived Fe-N-C catalyst for oxygen reduction using a facile one-pot process with no additional reagents. This process was carried out by ultrasonicating a mixture containing an iron precursor, an aniline monomer, and carbon black. The half-wave potential of the synthesized Fe-N-C catalyst for the ORR was only 10 mV less than that of a commercial Pt/C catalyst. The optimized Fe-N-C catalyst showed outstanding performance in a practical anion exchange membrane fuel cell (AEMFC), suggesting its potential as an alternative to commercial Pt/C catalysts for the ORR.

  15. Graphite oxide/metal-organic framework (MIL-101): remarkable performance in the adsorptive denitrogenation of model fuels.

    PubMed

    Ahmed, Imteaz; Khan, Nazmul Abedin; Jhung, Sung Hwa

    2013-12-16

    A highly porous metal-organic framework (MOF), MIL-101 (Cr-benzenedicarboxylate), was synthesized in the presence of graphite oxide (GO) to produce GO/MIL-101 composites. The porosity of the composites increased remarkably in the presence of a small amount of GO (<0.5% of MIL-101); however, further increases in GO reduced the porosity. GO also accelerated the synthesis of the MIL-101. The composites (GO/MIL-101) were used, for the first time, in liquid-phase adsorptions. The adsorptive removal of nitrogen-containing compounds (NCCs) and sulfur-containing compounds (SCCs) from model fuels demonstrated the potential applications of the composites in adsorptions, and the adsorption capacity was dependent on the surface area and pore volume of the composites. Most importantly, the GO/MIL-101 composite has the highest adsorption capacity for NCCs among reported adsorbents so far, partly because of the increased porosity of the composite. Finally, the results suggest that GO could be used in the synthesis of highly porous MOF composites, and the obtained materials could be used in various adsorptions in both liquid and gas/vapor phase (such as H2, CH4, and CO2 storage) adsorptions, because of the high porosity and functional GO.

  16. Modeling Electrochemical Performance of the Hierarchical Morphology of Precious Group Metal-free Cathode for Polymer Electrolyte Fuel Cell

    DOE PAGES

    Komini Babu, Siddharth; Chung, Hoon Taek; Zelenay, Piotr; ...

    2017-08-04

    Here, this paper presents a two-dimensional (2D) computational model of a polymer electrolyte fuel cell (PEFC) with a platinum group metal-free (PGM-free) catalyst cathode that can significantly reduce PEFC costs by eliminating the need for expensive platinum catalysts. Due to their comparatively low volumetric activity, PGM-free cathodes are an order of magnitude thicker than their Pt-based counterpart. The resulting need for greater electrode thickness to achieve sufficient power density requires careful attention to the transport losses across the thicker cathodes. The presented model is used to correlate the composition and morphology of the cathode to PEFC performance. The model ismore » a complete cell, continuum model that includes an advanced agglomerate model for a microstructurally consistent representation of the cathode. A unique feature of the approach is the integration of morphology and transport parameter statistics extracted from nano-scale resolution X-ray computed tomography (nano-CT) imaging of PGM-free cathodes. The model was validated with experimental results of PGM-free cathodes with varying Nafion loading. Lastly, our key findings are a need for increased cathode hydrophobicity and increased ionomer conductivity through either reduced tortuosity or increased bulk conductivity. We further use the model to evaluate targets for the volumetric activity and active site density for future catalysts.« less

  17. Fast ionic conduction in tetravalent metal pyrophosphate-alkali carbonate composites: New potential electrolytes for intermediate-temperature fuel cells

    NASA Astrophysics Data System (ADS)

    Singh, Bhupendra; Bhardwaj, Aman; Gautam, Sandeep K.; Kumar, Devendra; Parkash, Om; Kim, In-Ho; Song, Sun-Ju

    2017-03-01

    Here we present a report on synthesis and characterization of tetravalent metal pyrophosphate (TMP) and alkali carbonate (A2CO3; A = Li and/or Na) composites. The TMP-carbonate composites are prepared by mixing indium-doped tin pyrophosphate or yttrium-doped zirconium pyrophosphate with Li2CO3 or an eutectic mixture of Li2CO3-Na2CO3 in different wt.% ratios. The phase composition, microstructure and electrical conductivity of the sintered specimen are analyzed. In addition, the effect of different TMP and A2CO3 phases is investigated. A maximum ionic conductivity of 5.5 × 10-2 S cm-1 at 630 °C is observed in this study with a Sn0.9In0.1P2O7-Li2CO3 composite. Based on the literature data, TMP-carbonate composites can be considered to be primarily a proton and oxygen-ion co-ionic conductor and, therefore, have strong potential as electrolytes in fuel cells in 500-700 °C range.

  18. Report of Separate Effects Testing for Modeling of Metallic Fuel Casting Process

    SciTech Connect

    Crapps, Justin M.; Galloway, Jack D.; Decroix, David S.; Korzekwa, David A.; Aikin, Robert M. Jr.; Unal, Cetin; Fielding, R.; Kennedy, R

    2012-06-29

    In order to give guidance regarding the best investment of time and effort in experimental determination of parameters defining the casting process, a Flow-3D model of the casting process was used to investigate the most influential parameters regarding void fraction of the solidified rods and solidification speed for fluid flow parameters, liquid heat transfer parameters, and solid heat transfer parameters. Table 1 summarizes the most significant variables for each of the situations studied. A primary, secondary, and tertiary effect is provided for fluid flow parameters (impacts void fraction) and liquid heat transfer parameters (impacts solidification). In Table 1, the wetting angle represents the angle between the liquid and mold surface as pictured in Figure 1. The viscosity is the dynamic viscosity of the liquid and the surface tension is the property of the surface of a liquid that allows it to resist an external force. When only considering solid heat transfer properties, the variations from case to case were very small. Details on this conclusion are provided in the section considering solid heat transfer properties. The primary recommendation of the study is to measure the fluid flow parameters, specifically the wetting angle, surface tension, and dynamic viscosity, in order of importance, as well as the heat transfer parameters latent heat and specific heat of the liquid alloy. The wetting angle and surface tension can be measured simultaneously using the sessile drop method. It is unclear whether there is a temperature dependency in these properties. Thus measurements for all three parameters are requested at 1340, 1420, and 1500 degrees Celsius, which correspond to the minimum, middle, and maximum temperatures of the liquid alloy during the process. In addition, the heat transfer coefficient between the mold and liquid metal, the latent heat of transformation, and the specific heat of the liquid metal all have strong influences on solidification. These

  19. Conversion of light hydrocarbon gases to metal carbides for production of liquid fuels and chemicals. Quarterly technical status report, October 1--December 31, 1992

    SciTech Connect

    Diaz, A.F.; Modestino, A.J.; Howard, J.B.; Peters, W.A.

    1993-02-01

    Light hydrocarbon gases could be reacted with low cost alkaline earth metal oxide (CaO, MgO) in high-temperature plasma reactor to achieve very high ({le}100%) gas conversion to H{sub 2}, CO, and the corresponding metal carbides. These carbides could be stored, transported, and hydrolyzed to acetylene or methyl acetylene, which in turn could be upgraded to a wide range of chemicals and premium liquid hydrocarbon fuels. An electric arc discharge reactor was built for converting methane. Literature reviews were made.

  20. Reusable fuel test assembly for the FFTF

    SciTech Connect

    Pitner, A.L.; Dittmer, J.O. )

    1992-01-01

    A fuel test assembly that provides re-irradiation capability after interim discharge and reconstitution of the test pin bundle has been developed for use in the Fast Flux Test Facility (FFTF). This test vehicle permits irradiation test data to be obtained at multiple exposures on a few select test pins without the substantial expense of fabricating individual test assemblies as would otherwise be required. A variety of test pin types can be loaded in the reusable test assembly. A reusable test vehicle for irradiation testing in the FFTF has long been desired, but a number of obstacles previously prevented the implementation of such an experimental rig. The MFF-8A test assembly employs a 169-pin bundle using HT-9 alloy for duct and cladding material. The standard driver pins in the fuel bundle are sodium-bonded metal fuel (U-10 wt% Zr). Thirty-seven positions in the bundle are replaceable pin positions. Standard MFF-8A driver pins can be loaded in any test pin location to fill the bundle if necessary. Application of the MFF-8A reusable test assembly in the FFTF constitutes a considerable cost-saving measure with regard to irradiation testing. Only a few well-characterized test pins need be fabricated to conduct a test program rather than constructing entire test assemblies.