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Sample records for ce entrained fuel process

  1. Experimental studies on spray and gas entrainment characteristics of biodiesel fuel: Implications of gas entrained and fuel oxygen content on soot formation

    International Nuclear Information System (INIS)

    Kuti, Olawole Abiola; Nishida, Keiya; Zhu, Jingyu

    2013-01-01

    Experiments were performed inside the constant volume vessel to simulate the real diesel engine conditions. The LIF–PIV (Laser Induced Florescence – Particulate Image Velocimetry) technique was used to characterize the spray and gas entrainment characteristics of the fuels while the OH-chemiluminescence and two color pyrometry were applied to obtain information about the combustion processes. Biodiesel from palm oil (BDF (Biodiesel Fuel)) and the JIS #2 diesel fuel were utilized. It was observed that the SMD (Sauter mean diameter) obtained through an empirical equation decreased by increasing the injection pressure from 100 to 300 MPa and reducing the nozzle diameter from 0.16 to 0.08 mm. BDF has higher SMD values compared to diesel thus signifying inferior atomization. By increasing the injection pressure up to 300 MPa and reducing the nozzle diameter to 0.08 mm, the normal velocity and total mass flow rate of the entrained gas by the fuels increased. Due to higher viscosity and density properties, BDF possessed inferior atomization characteristics which made the normal velocity and total mass flow rate of the entrained gas lower compared to diesel. Due to inferior atomization which led to less gas being entrained upstream of the lift-off flame, the fuel oxygen content in BDF played a significant role in soot formation processes. - Highlights: • Spray and gas entrainment characteristics of biodiesel (BDF (Biodiesel Fuel)) and fuel were investigated. • Effect of injector parameters on BDF spray and gas entrainment characteristics was identified. • Higher viscosity and density of BDF yielded inferior spray atomization processes. • Gas entrainment velocity and mass flow rate of gas entrained by BDF lower. • Gas entrained had less effect on BDF's soot formation

  2. Fuel processing

    International Nuclear Information System (INIS)

    Allardice, R.H.

    1990-01-01

    The technical and economic viability of the fast breeder reactor as an electricity generating system depends not only upon the reactor performance but also on a capability to recycle plutonium efficiently, reliably and economically through the reactor and fuel cycle facilities. Thus the fuel cycle is an integral and essential part of the system. Fuel cycle research and development has focused on demonstrating that the challenging technical requirements of processing plutonium fuel could be met and that the sometimes conflicting requirements of the fuel developer, fuel fabricator and fuel reprocessor could be reconciled. Pilot plant operation and development and design studies have established both the technical and economic feasibility of the fuel cycle but scope for further improvement exists through process intensification and flowsheet optimization. These objectives and the increasing processing demands made by the continuing improvement to fuel design and irradiation performance provide an incentive for continuing fuel cycle development work. (author)

  3. Effect of wall impingement on ambient gas entrainment, fuel evaporation and mixture formation of diesel spray

    Energy Technology Data Exchange (ETDEWEB)

    Nishida, Keiya [Department of Mechanical Physics Engineering, University of Hiroshima (Japan); Matsumoto, Yuhei; Zhang, Wu [Mazda Motor Corp. (Japan); Gao, Jian [University of Wisconsin (United States); Moon, Seoksu [Argonne National Laboratory (United States)

    2010-07-01

    In the energy sector, with the implementation of stringent regulations on combustion emissions and the depletion of conventional fuels, there is a pressing need to improve the performance of engines. The purpose of this paper is to determine the impact of wall impingement on several characteristics of diesel spray. Experiments were carried out with both a small and a large amount of diesel spray injected and ambient gas entrainment, fuel evaporation and mixture formation were evaluated using an LAS optical system. Results showed that wall impingement has the same effects for small or large amounts of diesel spray injected; these are: a larger volume spray after the impingement and a smaller volume after it, the suppression of ambient gas entrainment and fuel evaporation, and the shift of the PDF peak of the vapor equivalent ratio. This study provided useful information but further work is needed to address the remaining issues.

  4. Solvent purification using a current of water vapour. A continuous process applicable to chemical plants treating irradiated fuels; Purification des solvants par entrainement a la vapeur d'eau. Procede continu applicable aux usines chimiques de traitement des combustibles irradies

    Energy Technology Data Exchange (ETDEWEB)

    Auchapt, P R; Sautray, R R; Girard, B R [Commissariat a l' Energie Atomique, Centre de Production de Plutonium, Marcoule (France). Centre d' Etudes Nucleaires

    1964-07-01

    The pilot plant described in this report is intended for the continuous purification of the solvent used in the plutonium extraction plant at Marcoule, by separating the impurities (fission products). This physical separation is operated by carrying over in a water vapour stream. The contaminating products, only slightly volatile, remain in the form of the droplets and are separated; the vaporised solvent and the water vapour used are condensed and then separated. The originality of the installation resides in the system for pulverising the liquid and in the operating conditions: low working pressure and temperature. The systematic analysis of the various parameters (percentage of residue; flow, pressure and temperature ratios etc...) has shown their influence on the decontamination. The activity due to the zirconium-niobium is undetectable after treatment, and it is easy to obtain decontamination factors of 300 for the ruthenium. The, presence of uranium is favorable for the decontamination. As a conclusion, some extra-technical considerations are given concerning in particular the approximate cost price of the treated solvent per litre. (authors) [French] L'installation pilote decrite dans ce rapport est destinee a purifier, en continu, le solvant utilise a l'usine d'extraction du plutonium de Marcoule, en separant les impuretes (produits de fission). Cette separation physique est realisee par entrainement a la vapeur d'eau. Les produits contaminants, peu volatils, restant sous forme de gouttelettes, sont separes; le solvant vaporise ainsi que la vapeur d'entrainement sont condenses puis separes. L'originalite de l'installation reside dans le systeme de pulverisation du liquide et dans les conditions operatoires: faible pression et basse temperature de fonctionnement. L'analyse systematique des differents parametres (pourcentage de residus, rapport de debits, pression et temperature, etc...) a mis en evidence leur influence sur la decontamination. L'activite en

  5. The role of high-level processes for oscillatory phase entrainment to speech sound

    Directory of Open Access Journals (Sweden)

    Benedikt eZoefel

    2015-12-01

    Full Text Available Constantly bombarded with input, the brain has the need to filter out relevant information while ignoring the irrelevant rest. A powerful tool may be represented by neural oscillations which entrain their high-excitability phase to important input while their low-excitability phase attenuates irrelevant information. Indeed, the alignment between brain oscillations and speech improves intelligibility and helps dissociating speakers during a cocktail party. Although well-investigated, the contribution of low- and high-level processes to phase entrainment to speech sound has only recently begun to be understood. Here, we review those findings, and concentrate on three main results: (1 Phase entrainment to speech sound is modulated by attention or predictions, likely supported by top-down signals and indicating higher-level processes involved in the brain’s adjustment to speech. (2 As phase entrainment to speech can be observed without systematic fluctuations in sound amplitude or spectral content, it does not only reflect a passive steady-state ringing of the cochlea, but entails a higher-level process. (3 The role of intelligibility for phase entrainment is debated. Recent results suggest that intelligibility modulates the behavioral consequences of entrainment, rather than directly affecting the strength of entrainment in auditory regions. We conclude that phase entrainment to speech reflects a sophisticated mechanism: Several high-level processes interact to optimally align neural oscillations with predicted events of high relevance, even when they are hidden in a continuous stream of background noise.

  6. Research on the pyrolysis of hardwood in an entrained bed process development unit

    Energy Technology Data Exchange (ETDEWEB)

    Kovac, R.J.; Gorton, C.W.; Knight, J.A.; Newman, C.J.; O' Neil, D.J. (Georgia Inst. of Tech., Atlanta, GA (United States). Research Inst.)

    1991-08-01

    An atmospheric flash pyrolysis process, the Georgia Tech Entrained Flow Pyrolysis Process, for the production of liquid biofuels from oak hardwood is described. The development of the process began with bench-scale studies and a conceptual design in the 1978--1981 timeframe. Its development and successful demonstration through research on the pyrolysis of hardwood in an entrained bed process development unit (PDU), in the period of 1982--1989, is presented. Oil yields (dry basis) up to 60% were achieved in the 1.5 ton-per-day PDU, far exceeding the initial target/forecast of 40% oil yields. Experimental data, based on over forty runs under steady-state conditions, supported by material and energy balances of near-100% closures, have been used to establish a process model which indicates that oil yields well in excess of 60% (dry basis) can be achieved in a commercial reactor. Experimental results demonstrate a gross product thermal efficiency of 94% and a net product thermal efficiency of 72% or more; the highest values yet achieved with a large-scale biomass liquefaction process. A conceptual manufacturing process and an economic analysis for liquid biofuel production at 60% oil yield from a 200-TPD commercial plant is reported. The plant appears to be profitable at contemporary fuel costs of $21/barrel oil-equivalent. Total capital investment is estimated at under $2.5 million. A rate-of-return on investment of 39.4% and a pay-out period of 2.1 years has been estimated. The manufacturing cost of the combustible pyrolysis oil is $2.70 per gigajoule. 20 figs., 87 tabs.

  7. Conceptual design of heterogeneous azeotropic distillation process for ethanol dehydration using 1-butanol as entrainer

    OpenAIRE

    Paritta Prayoonyong

    2014-01-01

    The synthesis of a heterogeneous azeotropic distillation process for ethanol dehydration using 1-butanol as entrainer is presented. The residue curve map of the ethanol/water/1-butanol mixture is computationally generated using non-random twoliquid thermodynamic model. It is found that 1-butanol leads to a residue curve map topological structure different from that generated by typical entrainers used in ethanol dehydration. Synthesis...

  8. Fuel processing. Wastes processing

    International Nuclear Information System (INIS)

    Bourgeois, M.

    2000-01-01

    The gaseous, liquid and solid radioactive effluents generated by the fuel reprocessing, can't be release in the environment. They have to be treated in order to respect the limits of the pollution regulations. These processing are detailed and discussed in this technical paper. A second part is devoted to the SPIN research program relative to the separation of the long life radionuclides in order to reduce the radioactive wastes storage volume. (A.L.B.)

  9. Fabrication and characterization of CeO{sub 2} pellets for simulation of nuclear fuel

    Energy Technology Data Exchange (ETDEWEB)

    García-Ostos, C.; Rodríguez-Ortiz, J.A. [Department of Mechanical and Materials Engineering, School of Engineering, University of Seville, Seville (Spain); Arévalo, C., E-mail: carevalo@us.es [Department of Mechanical and Materials Engineering, School of Engineering, University of Seville, Seville (Spain); Cobos, J. [CIEMAT, Avenida Complutense, 40, Madrid (Spain); Gotor, F.J. [Materials Science Institute of Seville (CSIC-US), Av. Américo Vespucio, 49, 41092 Seville (Spain); Torres, Y. [Department of Mechanical and Materials Engineering, School of Engineering, University of Seville, Seville (Spain)

    2016-03-15

    Highlights: • CeO{sub 2} is presented as a surrogate material for UO{sub 2} to study nuclear fuel. • Powder-metallurgy methods are applied to fabricate CeO{sub 2} pellets with controlled porosity. • An optimization of the fabrication parameters is established. • Microstructural and tribo-mechanical characterizations are performed. • Properties are compared to those of the nuclear fuel. - Abstract: Cerium Oxide, CeO{sub 2}, has been shown as a surrogate material to understand irradiated Mixed Oxide (MOX) based matrix fuel for nuclear power plants due to its similar structure, chemical and mechanical properties. In this work, CeO{sub 2} pellets with controlled porosity have been developed through conventional powder-metallurgy process. Influence of the main processing parameters (binder content, compaction pressure, sintering temperature and sintering time) on porosity and volumetric contraction values has been studied. Microstructure and physical properties of sintered compacts have also been characterized through several techniques. Mechanical properties such as dynamic Young's modulus, hardness and fracture toughness have been determined and connected to powder-metallurgy parameters. Simulation of nuclear fuel after reactor utilization with radial gradient porosity is proposed.

  10. Evaluation of BaZr0.1Ce0.7Y0.2O3-δ-based proton-conducting solid oxide fuel cells fabricated by a one-step co-firing process

    International Nuclear Information System (INIS)

    Sun Wenping; Wang Yanfei; Fang Shumin; Zhu Zhiwen; Yan Litao; Liu Wei

    2011-01-01

    Proton-conducting solid oxide fuel cells, incorporating BaZr 0.1 Ce 0.7 Y 0.2 O 3-δ (BZCY) electrolyte, NiO-BZCY anode, and Sm 0.5 Sr 0.5 CoO 3-δ -Ce 0.8 Sm 0.2 O 2-δ (SSC-SDC) cathode, were successfully fabricated by a combined co-pressing and printing technique after a one-step co-firing process at 1100, 1150, or 1200 o C. Scanning electron microscope (SEM) results revealed that the co-firing temperature significantly affected not only the density of the electrolyte membrane but the grain size and porosity of the electrodes. Influences of the co-firing temperature on the electrochemical performances of the single cells were also studied in detail. Using wet hydrogen (2% H 2 O) as the fuel and static air as the oxidant, the cell co-fired at 1150 o C showed the highest maximum power density (PD max ) of 552 and 370 mW cm -2 at 700 and 650 o C, respectively, while the one co-fired at 1100 o C showed the highest PD max of 276 and 170 mWcm -2 at 600 and 550 o C, respectively. The Arrhenius equation was proposed to analyze the dependence of the PD max on the operating temperature, and revealed that PD max of the cell co-fired at a lower temperature was less dependent on operating temperature. The influences of the co-firing temperature on the resistances of the single cells, which were estimated from the electrochemical impedance spectroscopy measured under open circuit conditions, were also investigated.

  11. Cortical oscillations and entrainment in speech processing during working memory load.

    Science.gov (United States)

    Hjortkjaer, Jens; Märcher-Rørsted, Jonatan; Fuglsang, Søren A; Dau, Torsten

    2018-02-02

    Neuronal oscillations are thought to play an important role in working memory (WM) and speech processing. Listening to speech in real-life situations is often cognitively demanding but it is unknown whether WM load influences how auditory cortical activity synchronizes to speech features. Here, we developed an auditory n-back paradigm to investigate cortical entrainment to speech envelope fluctuations under different degrees of WM load. We measured the electroencephalogram, pupil dilations and behavioural performance from 22 subjects listening to continuous speech with an embedded n-back task. The speech stimuli consisted of long spoken number sequences created to match natural speech in terms of sentence intonation, syllabic rate and phonetic content. To burden different WM functions during speech processing, listeners performed an n-back task on the speech sequences in different levels of background noise. Increasing WM load at higher n-back levels was associated with a decrease in posterior alpha power as well as increased pupil dilations. Frontal theta power increased at the start of the trial and increased additionally with higher n-back level. The observed alpha-theta power changes are consistent with visual n-back paradigms suggesting general oscillatory correlates of WM processing load. Speech entrainment was measured as a linear mapping between the envelope of the speech signal and low-frequency cortical activity (level) decreased cortical speech envelope entrainment. Although entrainment persisted under high load, our results suggest a top-down influence of WM processing on cortical speech entrainment. © 2018 The Authors. European Journal of Neuroscience published by Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  12. Conceptual design of heterogeneous azeotropic distillation process for ethanol dehydration using 1-butanol as entrainer

    Directory of Open Access Journals (Sweden)

    Paritta Prayoonyong

    2014-12-01

    Full Text Available The synthesis of a heterogeneous azeotropic distillation process for ethanol dehydration using 1-butanol as entrainer is presented. The residue curve map of the ethanol/water/1-butanol mixture is computationally generated using non-random twoliquid thermodynamic model. It is found that 1-butanol leads to a residue curve map topological structure different from that generated by typical entrainers used in ethanol dehydration. Synthesised by residue curve map analysis, the distillation flowsheet for ethanol dehydration by 1-butanol comprises a double-feed column integrated with an overhead decanter and a simple column. The double-feed column is used to recover water as the top product, whereas the simple column is used for recovering ethanol and 1-butanol. The separation feasibility and the economically near-optimal designs of distillation columns in the flowsheet are evaluated and identified by using the boundary value design method. The distillation flowsheet using 1-butanol is compared with the conventional process using benzene as entrainer. Based on their total annualised costs, the ethanol dehydration process using 1-butanol is less economically attractive than the process using benzene. However, 1-butanol is less toxic than benzene.

  13. Separation of ethanol and water by extractive distillation with salt and solvent as entrainer: process simulation

    OpenAIRE

    Gil, I. D.; Uyazán, A. M.; Aguilar, J. L.; Rodríguez, G.; Caicedo, L. A.

    2008-01-01

    The aim of this work is to simulate and analyze an extractive distillation process for azeotropic ethanol dehydration with ethylene glycol and calcium chloride mixture as entrainer. The work was developed with Aspen Plus® simulator version 11.1. Calculation of the activity coefficients employed to describe vapor liquid equilibrium of ethanol - water - ethylene glycol - calcium chloride system was done with the NRTL-E equation and they were validated with experimental data. The dehydration pro...

  14. Simultaneous design of ionic liquid entrainers and energy efficient azeotropic separation processes

    DEFF Research Database (Denmark)

    Roughton, Brock C.; Christian, Brianna; White, John

    2012-01-01

    A methodology and tool set for the simultaneous design of ionic liquid entrainers and azeotropic separation processes is presented. By adjusting the cation, anion, and alkyl chain length on the cation, the properties of the ionic liquid can be adjusted to design an entrainer for a given azeotropic...... mixture. Several group contribution property models available in literature have been used along with a newly developed group contribution solubility parameter model and UNIFAC model for ionic liquids (UNIFAC-IL). For a given azeotropic mixture, an ionic liquid is designed using a computer-aided molecular...... design (CAMD) method and the UNIFAC-IL model is used to screen design candidates based on minimum ionic liquid concentration needed to break the azeotrope. Once the ionic liquid has been designed, the extractive distillation column for the azeotropic mixture is designed using the driving force method...

  15. Demonstration of Entrained Solids and Sr/TRU Removal Processes with Archived AN-107 Waste

    International Nuclear Information System (INIS)

    Hallen, R.T.; Brooks, K.P.; Jagoda, L.K.

    2000-01-01

    Archived AN-107 waste was used to evaluate entrained solids removal, Sr/TRU decontamination of supernatant, and Sr/TRU solids removal. Even though most of the entrained solids had been previously removed from the archived sample, the residual entrained solids rapidly fouled the filter element resulting in very poor filter performance. An attempt to run at higher pressure resulted in more fouling, and reduced filter performance. Filtration efforts to remove entrained solids were abandoned and the waste was treated for Sr/TRU removal with the entrained solids present. The new processing scheme for Sr/TRU removal involving precipitation by added strontium and permanganate worked well. The decontamination factors for Sr and TRU components were significantly greater than the ILAW DF requirements for higher reagent concentrations of 1M hydroxide, 0.075M Sr, and 0.05M permanganate and lower reagent concentrations of 0.8M hydroxide, 0.05M Sr, and 0.03M permanganate. These results support the use of lower concentration of reagent additions in future tests. Optimization studies should be conducted to examine the reduction in added hydroxide from 1M to 0.5 M, reduction of Sr from 0.075M to 0.05M, and reduction in permanganate from 0.05M to 0.03M and the impact this reduction has on filtration performance with new samples from Tank AN-107. The combined entrained solids and Sr/TRU precipitate were successfully filtered in the single element, crossflow filtration unit. The filtrate flux was high, >0.1 gpm/ft 2 , at the initial test conditions of 53 psi and 11.2ft/s for the treated archived AN-107 sample. The filter flux rate dropped significantly with time as testing progressed and appears to be a result of shearing the agglomerated solids and fouling of the filter element by the resulting fine particles. The relatively low clean water flux rates obtained at the end of the test also indicate filter fouling. Chemical cleaning was required to restore clean water flux rates to pre

  16. Photodynamic Processes in Fluoride Crystals Doped with Ce3+

    Directory of Open Access Journals (Sweden)

    Pavlov V.V.

    2015-01-01

    Full Text Available Integrated studies of photoelectric phenomena and their associated photodynamic processes in LiCaAlF6, LiLuF4, LiYF4, LiY0,5Lu0,5F4, SrAlF5 crystals doped with Ce3+ ions have been carried out using the combination of the methods of optical and dielectric spectroscopy. The numerical values of the basic parameters of photodynamic processes and their spectral dependence in 240 – 310 nm spectral range are evaluated. It has been shown that the most probable process, which leads to the photoionization of Ce3+ ions in LiYxLu1-xF4:Ce3+ (x=0; 0,5; 1 and LiCaAlF6:Ce3+ crystals, is excited-state absorption to the states of mixed configurations of Ce3+ ions localized near/in the conduction band of crystal.

  17. Foaming and Antifoaming and Gas Entrainment in Radioactive Waste Pretreatment and Immobilization Processes. Final Report

    International Nuclear Information System (INIS)

    Wasan, Darsh T.

    2007-01-01

    The Savannah River Site (SRS) and Hanford site are in the process of stabilizing millions of gallons of radioactive waste slurries remaining from production of nuclear materials for the Department of Energy (DOE). The Defense Waste Processing Facility (DWPF) at SRS is currently vitrifying the waste in borosilicate glass, while the facilities at the Hanford site are in the construction phase. Both processes utilize slurry-fed joule-heated melters to vitrify the waste slurries. The DWPF has experienced difficulty during operations. The cause of the operational problems has been attributed to foaming, gas entrainment and the rheological properties of the process slurries. The rheological properties of the waste slurries limit the total solids content that can be processed by the remote equipment during the pretreatment and meter feed processes. Highly viscous material can lead to air entrainment during agitation and difficulties with pump operations. Excessive foaming in waste evaporators can cause carryover of radionuclides and non-radioactive waste to the condensate system. Experimental and theoretical investigations of the surface phenomena, suspension rheology and bubble generation of interactions that lead to foaming and air entrainment problems in the DOE High Level and Low Activity Radioactive Waste separation and immobilization processes were pursued under this project. The first major task accomplished in the grant proposal involved development of a theoretical model of the phenomenon of foaming in a three-phase gas-liquid-solid slurry system. This work was presented in a recently completed Ph.D. thesis (9). The second major task involved the investigation of the inter-particle interaction and microstructure formation in a model slurry by the batch sedimentation method. Both experiments and modeling studies were carried out. The results were presented in a recently completed Ph.D. thesis. The third task involved the use of laser confocal microscopy to study

  18. Fuels Processing Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — NETL’s Fuels Processing Laboratory in Morgantown, WV, provides researchers with the equipment they need to thoroughly explore the catalytic issues associated with...

  19. Ethanol dehydration via azeotropic distillation with gasoline fractions as entrainers: A pilot-scale study of the manufacture of an ethanol–hydrocarbon fuel blend

    OpenAIRE

    Gomis Yagües, Vicente; Pedraza Berenguer, Ricardo; Saquete Ferrándiz, María Dolores; Font, Alicia; Garcia-Cano, Jorge

    2015-01-01

    We establish experimentally and through simulations the economic and technical viability of dehydrating ethanol by means of azeotropic distillation, using a hydrocarbon as entrainer. The purpose of this is to manufacture a ready-to-use ethanol–hydrocarbon fuel blend. In order to demonstrate the feasibility of this proposition, we have tested an azeotropic water–ethanol feed mixture, using a hydrocarbon as entrainer, in a semi pilot-plant scale distillation column. Four different hydrocarbons ...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-12-05

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

  1. Detection of solvent losses (entrainment) in gas streams of process vessels using radioisotope tracing techniques

    International Nuclear Information System (INIS)

    Wan Zakaria Wan Muhamad Tahir; Juhari Mohd Yusof

    2002-01-01

    Liquid droplets (MDEA aqueous solution) entrained in the gas streams can cause severe problems on chemical plants. On-line detection of liquid entrainment (carry over) into gas streams from process vessel is investigated using radioisotope iodine ( 131 I). In order to obtain information on whether there is any carry-over of MDEA in the vapour space leaving from the process system, a number of test and calibration injections involving the released of certain amount of tracer activity (mCi) at the inlet and overhead lines of the process vessels were made using a special injection device. MDEA solvent- tagged tracer in the overhead line of the designated process vessels was monitored using radiation scintillation detectors mounted externally at specified locations of the vessels. Output pulses (response curves) with respect to time of measurements from all detectors were plotted and analysed for the finger prints of solvent losses leaving the vessels. From this study, no distinguishable peaks were detected at the outlet vessels of the overhead lines. Thus, no significant MDEA solvent losses in the form of vapour being discovered along the gas streams due to the process taking place in the system. (Author)

  2. Fuels processing for transportation fuel cell systems

    Science.gov (United States)

    Kumar, R.; Ahmed, S.

    Fuel cells primarily use hydrogen as the fuel. This hydrogen must be produced from other fuels such as natural gas or methanol. The fuel processor requirements are affected by the fuel to be converted, the type of fuel cell to be supplied, and the fuel cell application. The conventional fuel processing technology has been reexamined to determine how it must be adapted for use in demanding applications such as transportation. The two major fuel conversion processes are steam reforming and partial oxidation reforming. The former is established practice for stationary applications; the latter offers certain advantages for mobile systems and is presently in various stages of development. This paper discusses these fuel processing technologies and the more recent developments for fuel cell systems used in transportation. The need for new materials in fuels processing, particularly in the area of reforming catalysis and hydrogen purification, is discussed.

  3. Separation of ethanol and water by extractive distillation with salt and solvent as entrainer: process simulation

    Directory of Open Access Journals (Sweden)

    I. D. Gil

    2008-03-01

    Full Text Available The aim of this work is to simulate and analyze an extractive distillation process for azeotropic ethanol dehydration with ethylene glycol and calcium chloride mixture as entrainer. The work was developed with Aspen Plus® simulator version 11.1. Calculation of the activity coefficients employed to describe vapor liquid equilibrium of ethanol - water - ethylene glycol - calcium chloride system was done with the NRTL-E equation and they were validated with experimental data. The dehydration process used two columns: the main extractive column and the recovery column. The solvent to feed molar ratio S/F=0.3, molar reflux ratio RR=0.35, number of theoretical stages Ns=18, feed stage Sf=12, feed solvent stage SS=3, and feed solvent temperature TS=80 ºC, were determined to obtain a distillate with at least 99.5 % mole of ethanol. A substantial reduction in the energy consumption, compared with the conventional processes, was predicted by using ethylene glycol and calcium chloride as entrainer.

  4. Effect of oxy-fuel combustion with steam addition on coal ignition and burnout in an entrained flow reactor

    International Nuclear Information System (INIS)

    Riaza, J.; Alvarez, L.; Gil, M.V.; Pevida, C.; Pis, J.J.; Rubiera, F.

    2011-01-01

    The ignition temperature and burnout of a semi-anthracite and a high-volatile bituminous coal were studied under oxy-fuel combustion conditions in an entrained flow reactor (EFR). The results obtained under oxy-fuel atmospheres (21%O 2 -79%CO 2 , 30%O 2 -70% O 2 and 35%O 2 -65%CO 2 ) were compared with those attained in air. The replacement of CO 2 by 5, 10 and 20% of steam in the oxy-fuel combustion atmospheres was also evaluated in order to study the wet recirculation of flue gas. For the 21%O 2 -79%CO 2 atmosphere, the results indicated that the ignition temperature was higher and the coal burnout was lower than in air. However, when the O 2 concentration was increased to 30 and 35% in the oxy-fuel combustion atmosphere, the ignition temperature was lower and coal burnout was improved in comparison with air conditions. On the other hand, an increase in ignition temperature and a worsening of the coal burnout was observed when steam was added to the oxy-fuel combustion atmospheres though no relevant differences between the different steam concentrations were detected. -- Highlights: → The ignition temperature and the burnout of two thermal coals under oxy-fuel combustion conditions were determined. → The effect of the wet recirculation of flue gas on combustion behaviour was evaluated. → Addition of steam caused a worsening of the ignition temperature and coal burnout.

  5. Influence of Ce-precursor and fuel on structure and catalytic activity of combustion synthesized Ni/CeO{sub 2} catalysts for biogas oxidative steam reforming

    Energy Technology Data Exchange (ETDEWEB)

    Vita, Antonio, E-mail: antonio.vita@itae.cnr.it; Italiano, Cristina; Fabiano, Concetto; Laganà, Massimo; Pino, Lidia

    2015-08-01

    A series of nanosized Ni/CeO{sub 2} catalysts were prepared by Solution Combustion Synthesis (SCS) varying the fuel (oxalyldihydrazide, urea, carbohydrazide and glycerol), the cerium precursor (cerium nitrate and cerium ammonium nitrate) and the nickel loading (ranging between 3.1 and 15.6 wt%). The obtained powders were characterized by X-ray Diffraction (XRD), N{sub 2}-physisorption, CO-chemisorption, Temperature Programmed Reduction (H{sub 2}-TPR) and Scanning Electron Microscopy (SEM). The catalytic activity towards the Oxy Steam Reforming (OSR) of biogas was assessed. The selected operating variables have a strong influence on the nature of combustion and, in turn, on the morphological and structural properties of the synthesized catalysts. Particularly, the use of urea allows to improve nickel dispersion, surface area, particle size and reducibility of the catalysts, affecting positively the biogas OSR performances. - Highlights: • Synthesis of Ni/CeO{sub 2} nanopowders by quick and easy solution combustion synthesis. • The fuel and precursor drive the structural and morphological properties of the catalysts. • The use of urea as fuel allows to improve nickel dispersion, surface area and particle size. • Ni/CeO{sub 2} (7.8 wt% of Ni loading) powders synthesized by urea route exhibits high performances for the biogas OSR process.

  6. Influence of Ce-precursor and fuel on structure and catalytic activity of combustion synthesized Ni/CeO2 catalysts for biogas oxidative steam reforming

    International Nuclear Information System (INIS)

    Vita, Antonio; Italiano, Cristina; Fabiano, Concetto; Laganà, Massimo; Pino, Lidia

    2015-01-01

    A series of nanosized Ni/CeO 2 catalysts were prepared by Solution Combustion Synthesis (SCS) varying the fuel (oxalyldihydrazide, urea, carbohydrazide and glycerol), the cerium precursor (cerium nitrate and cerium ammonium nitrate) and the nickel loading (ranging between 3.1 and 15.6 wt%). The obtained powders were characterized by X-ray Diffraction (XRD), N 2 -physisorption, CO-chemisorption, Temperature Programmed Reduction (H 2 -TPR) and Scanning Electron Microscopy (SEM). The catalytic activity towards the Oxy Steam Reforming (OSR) of biogas was assessed. The selected operating variables have a strong influence on the nature of combustion and, in turn, on the morphological and structural properties of the synthesized catalysts. Particularly, the use of urea allows to improve nickel dispersion, surface area, particle size and reducibility of the catalysts, affecting positively the biogas OSR performances. - Highlights: • Synthesis of Ni/CeO 2 nanopowders by quick and easy solution combustion synthesis. • The fuel and precursor drive the structural and morphological properties of the catalysts. • The use of urea as fuel allows to improve nickel dispersion, surface area and particle size. • Ni/CeO 2 (7.8 wt% of Ni loading) powders synthesized by urea route exhibits high performances for the biogas OSR process

  7. Cortical oscillations and entrainment in speech processing during working memory load

    DEFF Research Database (Denmark)

    Hjortkjær, Jens; Märcher-Rørsted, Jonatan; Fuglsang, Søren A

    2018-01-01

    Neuronal oscillations are thought to play an important role in working memory (WM) and speech processing. Listening to speech in real-life situations is often cognitively demanding but it is unknown whether WM load influences how auditory cortical activity synchronizes to speech features. Here, we...... developed an auditory n-back paradigm to investigate cortical entrainment to speech envelope fluctuations under different degrees of WM load. We measured the electroencephalogram, pupil dilations and behavioural performance from 22 subjects listening to continuous speech with an embedded n-back task....... The speech stimuli consisted of long spoken number sequences created to match natural speech in terms of sentence intonation, syllabic rate and phonetic content. To burden different WM functions during speech processing, listeners performed an n-back task on the speech sequences in different levels...

  8. Dynamic modeling of Shell entrained flow gasifier in an integrated gasification combined cycle process

    International Nuclear Information System (INIS)

    Lee, Hyeon-Hui; Lee, Jae-Chul; Joo, Yong-Jin; Oh, Min; Lee, Chang-Ha

    2014-01-01

    Highlights: • Detailed dynamic model for the Shell entrained flow gasifier was developed. • The model included sub-models of reactor, membrane wall, gas quench and slag flow. • The dynamics of each zone including membrane wall in the gasifier were analyzed. • Cold gas efficiency (81.82%), gas fraction and temperature agreed with Shell data. • The model could be used as part of the overall IGCC simulation. - Abstract: The Shell coal gasification system is a single-stage, up-flow, oxygen-blown gasifier which utilizes dry pulverized coal with an entrained flow mechanism. Moreover, it has a membrane wall structure and operates in the slagging mode. This work provides a detailed dynamic model of the 300 MW Shell gasifier developed for use as part of an overall IGCC (integrated gasification combined cycle) process simulation. The model consists of several sub-models, such as a volatilization zone, reaction zone, quench zone, slag zone, and membrane wall zone, including heat transfers between the wall layers and steam generation. The dynamic results were illustrated and the validation of the gasifier model was confirmed by comparing the results in the steady state with the reference data. The product gases (H 2 and CO) began to come out from the exit of the reaction zone within 0.5 s, and nucleate boiling heat transfer was dominant in the water zone of the membrane wall due to high heat fluxes. The steady state of the process was reached at nearly t = 500 s, and our simulation data for the steady state, such as the temperature and composition of the syngas, the cold gas efficiency (81.82%), and carbon conversion (near 1.0) were in good agreement with the reference data

  9. Solvent purification using a current of water vapour. A continuous process applicable to chemical plants treating irradiated fuels; Purification des solvants par entrainement a la vapeur d'eau. Procede continu applicable aux usines chimiques de traitement des combustibles irradies

    Energy Technology Data Exchange (ETDEWEB)

    Auchapt, P.R.; Sautray, R.R.; Girard, B.R. [Commissariat a l' Energie Atomique, Centre de Production de Plutonium, Marcoule (France). Centre d' Etudes Nucleaires

    1964-07-01

    The pilot plant described in this report is intended for the continuous purification of the solvent used in the plutonium extraction plant at Marcoule, by separating the impurities (fission products). This physical separation is operated by carrying over in a water vapour stream. The contaminating products, only slightly volatile, remain in the form of the droplets and are separated; the vaporised solvent and the water vapour used are condensed and then separated. The originality of the installation resides in the system for pulverising the liquid and in the operating conditions: low working pressure and temperature. The systematic analysis of the various parameters (percentage of residue; flow, pressure and temperature ratios etc...) has shown their influence on the decontamination. The activity due to the zirconium-niobium is undetectable after treatment, and it is easy to obtain decontamination factors of 300 for the ruthenium. The, presence of uranium is favorable for the decontamination. As a conclusion, some extra-technical considerations are given concerning in particular the approximate cost price of the treated solvent per litre. (authors) [French] L'installation pilote decrite dans ce rapport est destinee a purifier, en continu, le solvant utilise a l'usine d'extraction du plutonium de Marcoule, en separant les impuretes (produits de fission). Cette separation physique est realisee par entrainement a la vapeur d'eau. Les produits contaminants, peu volatils, restant sous forme de gouttelettes, sont separes; le solvant vaporise ainsi que la vapeur d'entrainement sont condenses puis separes. L'originalite de l'installation reside dans le systeme de pulverisation du liquide et dans les conditions operatoires: faible pression et basse temperature de fonctionnement. L'analyse systematique des differents parametres (pourcentage de residus, rapport de debits, pression et temperature, etc...) a mis en evidence leur influence

  10. PCI/SCC failure behavior of KWU/CE fuel rods

    International Nuclear Information System (INIS)

    Kikuchi, Akira

    1983-10-01

    The Over Ramp (Studsvik Over Ramp-STOR) project is an international power ramping irradiation program for studying PCI/SCC failure behavior of PWR-fuel rods. The project had its activities for about three years (Apr., 1977 - Dec., 1980) as the cooperation works of twelve participants composing nine countries. The present report introduces the irradiation data on the KWU/CE fuel rods in the project and discusses the failure behavior of PWR-fuel rods. (author)

  11. Fusion reactor fuel processing

    International Nuclear Information System (INIS)

    Johnson, E.F.

    1972-06-01

    For thermonuclear power reactors based on the continuous fusion of deuterium and tritium the principal fuel processing problems occur in maintaining desired compositions in the primary fuel cycled through the reactor, in the recovery of tritium bred in the blanket surrounding the reactor, and in the prevention of tritium loss to the environment. Since all fuel recycled through the reactor must be cooled to cryogenic conditions for reinjection into the reactor, cryogenic fractional distillation is a likely process for controlling the primary fuel stream composition. Another practical possibility is the permeation of the hydrogen isotopes through thin metal membranes. The removal of tritium from the ash discharged from the power system would be accomplished by chemical procedures to assure physiologically safe concentration levels. The recovery process for tritium from the breeder blanket depends on the nature of the blanket fluids. For molten lithium the only practicable possibility appears to be permeation from the liquid phase. For molten salts the process would involve stripping with inert gas followed by chemical recovery. In either case extremely low concentrations of tritium in the melts would be desirable to maintain low tritium inventories, and to minimize escape of tritium through unwanted permeation, and to avoid embrittlement of metal walls. 21 refs

  12. REGSOLexpert: Entrainer Selection Tool for waste solvent recovery by batch distillation processes

    OpenAIRE

    Rodriguez-Donis, Ivonne; Gerbaud, Vincent; Baudouin, Olivier; Joulia, Xavier

    2009-01-01

    A general procedure to systematize the search of several alternatives enabling the separation of non-ideal binary mixtures such as pressure-swing distillation, azeotropic and extractive distillation is presented. The use of heterogeneous entrainers is specially highlighted.

  13. Health Effects Associated with Inhalation Exposure to Diesel Emission Generated with and without CeO2 Nano Fuel Additive

    Science.gov (United States)

    Diesel exhaust (DE) exposure induces adverse cardiopulmonary effects. Addition of nano cerium (Ce) oxide additive to diesel fuel (DECe) increases fuel burning efficiency resulting in altered emission characteristics and potentially altered health effects. We hypothesized that inh...

  14. Electrochemical reduction of CerMet fuels for transmutation using surrogate CeO2-Mo pellets

    Science.gov (United States)

    Claux, B.; Souček, P.; Malmbeck, R.; Rodrigues, A.; Glatz, J.-P.

    2017-08-01

    One of the concepts chosen for the transmutation of minor actinides in Accelerator Driven Systems or fast reactors proposes the use of fuels and targets containing minor actinides oxides embedded in an inert matrix either composed of molybdenum metal (CerMet fuel) or of ceramic magnesium oxide (CerCer fuel). Since the sufficient transmutation cannot be achieved in a single step, it requires multi-recycling of the fuel including recovery of the not transmuted minor actinides. In the present work, a pyrochemical process for treatment of Mo metal inert matrix based CerMet fuels is studied, particularly the electroreduction in molten chloride salt as a head-end step required prior the main separation process. At the initial stage, different inactive pellets simulating the fuel containing CeO2 as minor actinide surrogates were examined. The main studied parameters of the process efficiency were the porosity and composition of the pellets and the process parameters as current density and passed charge. The results indicated the feasibility of the process, gave insight into its limiting parameters and defined the parameters for the future experiment on minor actinide containing material.

  15. Compound process fuel cycle concept

    International Nuclear Information System (INIS)

    Ikegami, Tetsuo

    2005-01-01

    Mass flow of light water reactor spent fuel for a newly proposed nuclear fuel cycle concept 'Compound Process Fuel Cycle' has been studied in order to assess the capacity of the concept for accepting light water reactor spent fuels, taking an example for boiling water reactor mixed oxide spent fuel of 60 GWd/t burn-up and for a fast reactor core of 3 GW thermal output. The acceptable heavy metal of boiling water reactor mixed oxide spent fuel is about 3.7 t/y/reactor while the burn-up of the recycled fuel is about 160 GWd/t and about 1.6 t/y reactor with the recycled fuel burn-up of about 300 GWd/t, in the case of 2 times recycle and 4 times recycle respectively. The compound process fuel cycle concept has such flexibility that it can accept so much light water reactor spent fuels as to suppress the light water reactor spent fuel pile-up if not so high fuel burn-up is expected, and can aim at high fuel burn-up if the light water reactor spent fuel pile-up is not so much. Following distinctive features of the concept have also been revealed. A sort of ideal utilization of boiling water reactor mixed oxide spent fuel might be achieved through this concept, since both plutonium and minor actinide reach equilibrium state beyond 2 times recycle. Changes of the reactivity coefficients during recycles are mild, giving roughly same level of reactivity coefficients as the conventional large scale fast breeder core. Both the radio-activity and the heat generation after 4 year cooling and after 4 times recycle are less than 2.5 times of those of the pre recycle fuel. (author)

  16. Facile preparation of self-healing superhydrophobic CeO2 surface by electrochemical processes

    Science.gov (United States)

    Nakayama, Katsutoshi; Hiraga, Takuya; Zhu, Chunyu; Tsuji, Etsushi; Aoki, Yoshitaka; Habazaki, Hiroki

    2017-11-01

    Herein we report simple electrochemical processes to fabricate a self-healing superhydrophobic CeO2 coating on Type 304 stainless steel. The CeO2 surface anodically deposited on flat stainless steel surface is hydrophilic, although high temperature-sintered and sputter-deposited CeO2 surface was reported to be hydrophobic. The anodically deposited hydrophilic CeO2 surface is transformed to hydrophobic during air exposure. Specific accumulation of contaminant hydrocarbon on the CeO2 surface is responsible for the transformation to hydrophobic state. The deposition of CeO2 on hierarchically rough stainless steel surface produces superhydrophobic CeO2 surface, which also shows self-healing ability; the surface changes to superhydrophilic after oxygen plasma treatment but superhydrophobic state is recovered repeatedly by air exposure. This work provides a facile method for preparing a self-healing superhydrophobic surface using practical electrochemical processes.

  17. Catalytic processes for cleaner fuels

    International Nuclear Information System (INIS)

    Catani, R.; Marchionna, M.; Rossini, S.

    1999-01-01

    More stringent limitations on vehicle emissions require different measurement: fuel reformulation is one of the most important and is calling for a noticeable impact on refinery assets. Composition rangers of the future fuels have been defined on a time scale. In this scenario the evolution of catalytic technologies becomes a fundamental tool for allowing refinery to reach the fixed-by-law targets. In this paper, the refinery process options to meet each specific requirements of reformulated fuels are surveyed [it

  18. Entrainment by turbulent plumes

    Science.gov (United States)

    Parker, David; Burridge, Henry; Partridge, Jamie; Linden, Paul

    2017-11-01

    Plumes are of relevance to nature and real consequence to industry. While the Morton, Taylor & Turner (1956) plume model is able to estimate the mean physical flux parameters, the process of entrainment is only parametrised in a time-averaged sense and a deeper understanding is key to understanding how they evolve. Various flow configurations, resulting in different entrainment values, are considered; we perform simultaneous PIV and plume-edge detection on saline plumes in water resulting from a point source, a line source and a line source where a vertical wall is placed immediately adjacent. Of particular interest is the effect the large scale eddies, forming at the edge of the plume and engulfing ambient fluid, have on the entrainment process. By using velocity statistics in a coordinate system based on the instantaneous scalar edge of the plume the significance of this large scale engulfment is quantified. It is found that significant mass is transported outside the plumes, in particular in regions where large scale structures are absent creating regions of relatively high-momentum ambient fluid. This suggests that the large scale processes, whereby ambient fluid is engulfed into the plume, contribute significantly to the entrainment.

  19. Entrained Flow Gasification of Biomass

    DEFF Research Database (Denmark)

    Qin, Ke

    The present Ph. D. thesis describes experimental and modeling investigations on entrained flow gasification of biomass and an experimental investigation on entrained flow cogasification of biomass and coal. A review of the current knowledge of biomass entrained flow gasification is presented....... Biomass gasification experiments were performed in a laboratory-scale atmospheric pressure entrained flow reactor with the aim to investigate the effects of operating parameters and biomass types on syngas products. A wide range of operating parameters was involved: reactor temperature, steam/carbon ratio......, excess air ratio, oxygen concentration, feeder gas flow, and residence time. Wood, straw, and lignin were used as biomass fuels. In general, the carbon conversion was higher than 90 % in the biomass gasification experiments conducted at high temperatures (> 1200 °C). The biomass carbon...

  20. Evaluation of Pd Nanoparticle-Decorated CeO2-MWCNT Nanocomposite as an Electrocatalyst for Formic Acid Fuel Cells

    Science.gov (United States)

    Saleem, Junaid; Safdar Hossain, SK.; Al-Ahmed, Amir; Rahman, Ateequr; McKay, Gordon; Hossain, Mohammed M.

    2018-04-01

    In this work, CeO2-modified Pd/CeO2-carbon nanotube (CNT) electrocatalyst for the electro-oxidation of formic acid has been investigated. The support CNT was first modified with different amounts (5-30 wt.%) of CeO2 using a precipitation-deposition method. The electrocatalysts were developed by dispersing Pd on the CeO2-CNT supports using the borohydride reduction method. The synthesized electrocatalysts were analyzed for composition, morphology and electronic structure using x-ray diffraction (XRD), scanning electron microscopy with energy-dispersive x-ray spectroscopy (SEM/EDX), transmission electron microscopy (TEM), x-ray photoelectron spectroscopy (XPS), and thermogravimetric analysis (TGA) techniques. The formation of Pd nanoparticles on the CeO2-CNT support was confirmed using TEM. The activity of Pd/CeO2-CNT and of Pd-CNT samples upon oxidation of formic acid was evaluated by using carbon monoxide stripping voltammetry, cyclic voltammetry, and chronoamperometry. The addition of moderate amounts of cerium oxide (up to 10 wt.%) significantly improved the activity of Pd/CeO2-CNT compared to the unmodified Pd-CNT. Pd/10 wt.% CeO2-CNT showed a current density of 2 A mg-1, which is ten times higher than that of the unmodified Pd-CNT (0.2 A mg-1). Similarly, the power density obtained for Pd/10 wt.% CeO2-CNT in an air-breathing formic acid fuel cell was 6.8 mW/cm2 which is two times higher than Pd-CNT (3.2 mW/cm2), thus exhibiting the promotional effects of CeO2 to Pd/CeO2-CNT. A plausible justification for the improved catalytic performance and stability is provided in the light of the physical characterization results.

  1. Spray Processes in Optical Diesel Engines - Air-Entrainement and Emissions

    OpenAIRE

    Chartier, Clement

    2012-01-01

    Internal combustion engines have been an important technological field for more than a century. It has had an important impact on society through improved transportation and industrial applications. However, concerns about environmental effects of exhaust gases and utilization of oil resources have pushed development of combustion engines towards cleaner combustion and higher efficiencies. The diesel engine is today an interesting solution in terms of fuel economy. However, emissions ...

  2. Reflooding phase of the LOCA - state of the art II. Rewetting and liquid entrainment

    International Nuclear Information System (INIS)

    Elias, E.; Yadigaroglu, G.

    1977-01-01

    Understanding the mechanisms by which hot fuel rods quench and the physics of liquid droplet entrainment is important for the analysis of the reflooding phase of the LOCA. Published models of the rewetting process include simple one-dimensional solutions. The basic physical assumptions of these models and the numerical values assigned to the various parameters, as well as empirical rewetting correlations are discussed. The various mechanisms for liquid droplet entrainment and analytical formulations of the critical gas velocity and of the droplet diameter at the onset of entrainment are reviewed

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

    Science.gov (United States)

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

    2012-11-01

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

  4. Integrated chemical process for exothermic wave synthesis of high luminance YAG:Ce phosphors

    International Nuclear Information System (INIS)

    Won, C.W.; Nersisyan, H.H.; Won, H.I.; Youn, J.W.

    2011-01-01

    In this paper, high-luminance yellow-emitting Y 3 Al 5 O 12 :Ce 3+ phosphor (YAG:Ce) microparticles were prepared in a solid flame using a 1.425Y 2 O 3 +2.5Al 2 O 3 +0.15CeO 2 +k(KClO 3 +urea)+mNH 4 F precursor mixture (here k is the number of moles of the KClO 3 +urea red-ox mixture, and m is the number of moles of NH 4 F). The self-sustaining combustion process for the entire reaction sample was provided by the heat generated from the KClO 3 +urea mixture. Parametric studies demonstrated that the maximum temperature in the combustion wave varied from 885 to 1200 deg. C for k=2.0-3.0 mole and m=0-1.5 mole. X-ray analysis results showed that the product obtained in the solid flame consisted of Y 3 Al 5 O 12 :Ce 3+ and KCl phases. Therefore, after dissolving potassium chloride in distillated water, pure-phase YAG:Ce phosphor powder was obtained. The as-prepared YAG:Ce phosphor particles had diameters of 10-25 μm and good dispersity and exhibited luminescence properties comparable to those of YAG:Ce phosphor powders prepared by conventional high-temperature processing. - Highlights: → A new solid-flame strategy was developed for synthesizing high-luminance YAG:Ce phosphor. → Adding KClO 3 +CO(NH 2 ) 2 +NH 4 F mixture to oxide powders provides a low-temperature combustion process. → YAG:Ce phosphor particles 10-25 μm in diameter were obtained at 1000-1100 deg. C within tens of seconds. → As-prepared YAG:Ce emission intensity was 90.1-103.2% compared to that of the reference sample.

  5. Process for removal of sulfur compounds from fuel gases

    Science.gov (United States)

    Moore, Raymond H.; Stegen, Gary E.

    1978-01-01

    Fuel gases such as those produced in the gasification of coal are stripped of sulfur compounds and particulate matter by contact with molten metal salt. The fuel gas and salt are intimately mixed by passage through a venturi or other constriction in which the fuel gas entrains the molten salt as dispersed droplets to a gas-liquid separator. The separated molten salt is divided into a major and a minor flow portion with the minor flow portion passing on to a regenerator in which it is contacted with steam and carbon dioxide as strip gas to remove sulfur compounds. The strip gas is further processed to recover sulfur. The depleted, minor flow portion of salt is passed again into contact with the fuel gas for further sulfur removal from the gas. The sulfur depleted, fuel gas then flows through a solid absorbent for removal of salt droplets. The minor flow portion of the molten salt is then recombined with the major flow portion for feed to the venturi.

  6. Enhanced electro-oxidation of ethanol using PtSn/CeO{sub 2}-C electrocatalyst prepared by an alcohol-reduction process

    Energy Technology Data Exchange (ETDEWEB)

    Neto, Almir Oliveira; Farias, Luciana A.; Dias, Ricardo R.; Brandalise, Michelle; Linardi, Marcelo; Spinace, Estevam V. [Instituto de Pesquisas Energeticas e Nucleares, IPEN/CNEN-SP, Av. Prof. Lineu Prestes, 2242 - Cidade Universitaria, CEP 05508-900 Sao Paulo-SP (Brazil)

    2008-09-15

    PtSn/CeO{sub 2}-C electrocatalysts were prepared by an alcohol-reduction process using ethylene glycol as solvent and reduction agent and CeO{sub 2} and Vulcan Carbon XC72 as supports. The electrocatalysts were characterized by EDX and XRD. The electro-oxidation of ethanol was studied at room temperature by chronoamperometry. PtSn/CeO{sub 2}-C electrocatalyst with 15 wt% of CeO{sub 2} showed a significant increase of performance for ethanol oxidation compared to PtSn/C catalyst. Preliminary tests at 100C on a single cell of a direct ethanol fuel cell (DEFC) also confirm the results obtained by chronoamperometry. (author)

  7. A secondary fuel removal process: plasma processing

    Energy Technology Data Exchange (ETDEWEB)

    Min, J Y; Kim, Y S [Hanyang Univ., Seoul (Korea, Republic of); Bae, K K; Yang, M S [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1997-07-01

    Plasma etching process of UO{sub 2} by using fluorine containing gas plasma is studied as a secondary fuel removal process for DUPIC (Direct Use of PWR spent fuel Into Candu) process which is taken into consideration for potential future fuel cycle in Korea. CF{sub 4}/O{sub 2} gas mixture is chosen for reactant gas and the etching rates of UO{sub 2} by the gas plasma are investigated as functions of CF{sub 4}/O{sub 2} ratio, plasma power, substrate temperature, and plasma gas pressure. It is found that the optimum CF{sub 4}/O{sub 2} ratio is around 4:1 at all temperatures up to 400 deg C and the etching rate increases with increasing r.f. power and substrate temperature. Under 150W r.f. power the etching rate reaches 1100 monolayers/min at 400 deg C, which is equivalent to about 0.5mm/min. (author).

  8. Low-Frequency Cortical Entrainment to Speech Reflects Phoneme-Level Processing.

    Science.gov (United States)

    Di Liberto, Giovanni M; O'Sullivan, James A; Lalor, Edmund C

    2015-10-05

    The human ability to understand speech is underpinned by a hierarchical auditory system whose successive stages process increasingly complex attributes of the acoustic input. It has been suggested that to produce categorical speech perception, this system must elicit consistent neural responses to speech tokens (e.g., phonemes) despite variations in their acoustics. Here, using electroencephalography (EEG), we provide evidence for this categorical phoneme-level speech processing by showing that the relationship between continuous speech and neural activity is best described when that speech is represented using both low-level spectrotemporal information and categorical labeling of phonetic features. Furthermore, the mapping between phonemes and EEG becomes more discriminative for phonetic features at longer latencies, in line with what one might expect from a hierarchical system. Importantly, these effects are not seen for time-reversed speech. These findings may form the basis for future research on natural language processing in specific cohorts of interest and for broader insights into how brains transform acoustic input into meaning. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Co-combustion of pulverized coal and solid recovered fuel in an entrained flow reactor- General combustion and ash behavior

    DEFF Research Database (Denmark)

    Wu, Hao; Glarborg, Peter; Frandsen, Flemming

    2011-01-01

    .9 wt.%, 14.8 wt.% and 25 wt.%, respectively. The effect of additives was evaluated by maintaining the share of secondary fuel (mixture of SRF and additive) at 14.8 wt.%. The experimental results showed that the fuel burnout, NO and SO2 emission in co-combustion of coal and SRF were decreased...... with increasing share of SRF. The majority of the additives inhibited the burnout, except for NaCl which seemed to have a promoting effect. The impact of additives on NO emission was mostly insignificant, except for ammonium sulphate which greatly reduced the NO emission. For SO2 emission, it was found that all...

  10. Green power production by co-gasification of biomass in coal-fired oxygen-blown entrained-flow based IGCC processes

    Energy Technology Data Exchange (ETDEWEB)

    Van Ree, R; Korbee, R; De Smidt, R P; Jansen, D [ECN Fuels Conversion and Environment, Petten (Netherlands); Baumann, H R; Ullrich, N [Krupp Uhde, Dortmund (Germany); Haupt, G; Zimmerman, [Siemens, Erlangen (Germany)

    1998-11-01

    The use of coal for large scale power production meets a growing environmental concern. In spite of the fact that clean coal conversion technologies integrated with high-efficiency power production facilities, such as IGCC, are developed, the aim for sustainable development strives for a power production system based on renewable energy sources. One of the most promising renewable energy sources that can be used in the Netherlands is biomass, i.e. organic waste materials and/or energy crops. To accelerate the introduction of this material, in a technical and economically acceptable way, co-gasification with fossil fuels, in particular coal, in large scale IGCC processes is considered. In this paper the technical feasibility, economic profitability, and environmental acceptability of co-gasification of biomass in coal-fired oxygen-blown entrained-flow based IGM is discussed. Both a base-case coal-fired oxygen-blown entrained-flow based IGCC process - showing strong resemblance to the Puertollano IGCC plant in Spain - and three co-gasification concepts, viz.: (1) a concept with separate dry coal and biomass feeding systems, (2) a concept with a combined dry coal/biomass-derived pyrolysis char feeding system, and (3) a concept with parallel biomass pre-treatment/gasification and combined fuel gas clean-up/power production, were defined for further consideration. The base-case system and the co-gasification concepts as well are modelled in the flowsheet simulation package ASPEN{sup +}. Steady-state integral system calculations resulted in an overall net electrical plant efficiency for the base-case system of 50. 1 %LHV (48.3 %HHV). Replacing about 10 % of the total thermal plant input (coal) by biomass (willow) resulted in a decrease of the overall net electrical plant efficiency of 1.4 to 2.1 %-points LHV, avoided specific CO2 emissions of 40-49 g/kWh{sub e}, and total avoided CO2 emissions of about 129 to 159 kt/a, all depending on the co-gasification concept

  11. Effects of entrained gas on the acoustic detection of sodium boiling in a simulated LMFBR fuel bundle

    International Nuclear Information System (INIS)

    Leavell, W.H.; Sides, W.H.

    1975-01-01

    The relationship between acoustic intensity of nucleate boiling and void fraction was studied in a simulated LMFBR fuel bundle. Results indicate that as the void fraction increases the detected intensity of nucleate boiling decreased until it was indistinguishable from background noise. (JWR)

  12. Reducing the Entrainment of Gangue Fines in Low Grade Microcrystalline Graphite Ore Flotation Using Multi-Stage Grinding-Flotation Process

    Directory of Open Access Journals (Sweden)

    Xiaoqing Weng

    2017-03-01

    Full Text Available A suitable grinding fineness and flow-sheet could potentially reduce the mechanical entrainment of gangue minerals in the flotation process of microcrystalline graphite. In this study, the suitable grinding fineness of a commercial graphite ore was estimated by mineralogy analysis and laboratory grind-flotation tests. The target grind size of this ore should be 92% passing 74 μm based on the mineralogical evaluation and the flotation performance. A comparison of a single-stage and a three-stage grinding circuit was conducted. Experimental results demonstrated that the three-stage grinding circuit could effectively improve the separation effect, which was attributed to the reduction of slimes. In the end, a more desirable beneficiation result was obtained with the application of three-stage grinding-flotation process by minimizing gangue entrainment.

  13. Dry Process Fuel Performance Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Myung Seung; Song, K. C.; Moon, J. S. and others

    2005-04-15

    The objective of the project is to establish the performance evaluation system of DUPIC fuel during the Phase II R and D. In order to fulfil this objectives, irradiation test of DUPIC fuel was carried out in HANARO using the non-instrumented and SPND-instrumented rig. Also, the analysis on the in-reactor behavior analysis of DUPIC fuel, out-pile test using simulated DUPIC fuel as well as performance and integrity assessment in a commercial reactor were performed during this Phase. The R and D results of the Phase II are summarized as follows : - Performance evaluation of DUPIC fuel via irradiation test in HANARO - Post irradiation examination of irradiated fuel and performance analysis - Development of DUPIC fuel performance code (modified ELESTRES) considering material properties of DUPIC fuel - Irradiation behavior and integrity assessment under the design power envelope of DUPIC fuel - Foundamental technology development of thermal/mechanical performance evaluation using ANSYS (FEM package)

  14. Dry Process Fuel Performance Evaluation

    International Nuclear Information System (INIS)

    Yang, Myung Seung; Song, K. C.; Moon, J. S. and others

    2005-04-01

    The objective of the project is to establish the performance evaluation system of DUPIC fuel during the Phase II R and D. In order to fulfil this objectives, irradiation test of DUPIC fuel was carried out in HANARO using the non-instrumented and SPND-instrumented rig. Also, the analysis on the in-reactor behavior analysis of DUPIC fuel, out-pile test using simulated DUPIC fuel as well as performance and integrity assessment in a commercial reactor were performed during this Phase. The R and D results of the Phase II are summarized as follows : - Performance evaluation of DUPIC fuel via irradiation test in HANARO - Post irradiation examination of irradiated fuel and performance analysis - Development of DUPIC fuel performance code (modified ELESTRES) considering material properties of DUPIC fuel - Irradiation behavior and integrity assessment under the design power envelope of DUPIC fuel - Foundamental technology development of thermal/mechanical performance evaluation using ANSYS (FEM package)

  15. Neural Entrainment to Speech Modulates Speech Intelligibility

    NARCIS (Netherlands)

    Riecke, Lars; Formisano, Elia; Sorger, Bettina; Baskent, Deniz; Gaudrain, Etienne

    2018-01-01

    Speech is crucial for communication in everyday life. Speech-brain entrainment, the alignment of neural activity to the slow temporal fluctuations (envelope) of acoustic speech input, is a ubiquitous element of current theories of speech processing. Associations between speech-brain entrainment and

  16. Constraining Mantle Differentiation Processes with La-Ce and Sm-Nd Isotope Systematics

    Science.gov (United States)

    Willig, M.; Stracke, A.

    2016-12-01

    Cerium (Ce) and Neodymium (Nd) isotopic ratios in oceanic basalts reflect the time integrated La-Ce and Sm-Nd ratios, and hence the extent of light rare earth element element (LREE) depletion or enrichment of their mantle sources. New high precision Ce-Nd isotope data from several ocean islands define a tight array in ԑCe-ԑNd space with ԑNd = -8.2±0.4 ԑCe + 1.3±0.9 (S.D.), in good agreement with previous data [1, 2]. The slope of the ԑCe-ԑNd array and the overall isotopic range are sensitive indicators of the processes that govern the evolution of the mantle's LREE composition. A Monte Carlo approach is employed to simulate continuous mantle-crust differentiation by partial melting and recycling of crustal materials. Partial melting of mantle peridotites produces variably depleted mantle and oceanic crust, which evolve for different time periods, before the oceanic crust is recycled back into the mantle including small amounts of continental crust (GLOSS [3]). Subsequently, depleted mantle and recycled materials of variable age and composition melt, and the respective melts mix in different proportions. Mixing lines strongly curve towards depleted mantle, and tend to be offset from the data for increasingly older and more depleted mantle. Observed ԑCe-ԑNd in ridge [1] and ocean island basalts and the slope of the ԑCe-ԑNd array therefore define upper limits for the extent and age of LREE depletion preserved in mantle peridotites. Very old average mantle depletion ages (> ca. 1-2 Ga) for the bulk of the mantle are difficult to reconcile with the existing ԑCe-ԑNd data, consistent with the range of Nd-Hf-Os model ages in abyssal peridotites [4-6]. Moreover, unless small amounts of continental crust are included in the recycled material, it is difficult to reproduce the relatively shallow slope of the ԑCe-ԑNd array, consistent with constraints from the ԑNd - ԑHf mantle array [7]. [1] Makishima and Masuda, 1994 Chem. Geol. 118, 1-8. [2] Doucelance et al

  17. Collective processing device for spent fuel

    International Nuclear Information System (INIS)

    Irie, Hiroaki; Taniguchi, Noboru.

    1996-01-01

    The device of the present invention comprises a sealing vessel, a transporting device for transporting spent fuels to the sealing vessel, a laser beam cutting device for cutting the transported spent fuels, a dissolving device for dissolving the cut spent fuels, and a recovering device for recovering radioactive materials from the spent fuels during processing. Reprocessing treatments comprising each processing of dismantling, shearing and dissolving are conducted in the sealing vessel can ensure a sealing barrier for the radioactive materials (fissionable products and heavy nuclides). Then, since spent fuels can be processed in a state of assemblies, and the spent fuels are easily placed in the sealing vessel, operation efficiency is improved, as well as operation cost is saved. Further, since the spent fuels can be cut by a remote laser beam operation, there can be prevented operator's exposure due to radioactive materials released from the spent fuels during cutting operation. (T.M.)

  18. Dry process fuel performance technology development

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Kweon Ho; Kim, K. W.; Kim, B. K. (and others)

    2006-06-15

    The objective of the project is to establish the performance evaluation system of DUPIC fuel during the Phase III R and D. In order to fulfil this objectives, property model development of DUPIC fuel and irradiation test was carried out in Hanaro using the instrumented rig. Also, the analysis on the in-reactor behavior analysis of DUPIC fuel, out-pile test using simulated DUPIC fuel as well as performance and integrity assessment in a commercial reactor were performed during this Phase. The R and D results of the Phase III are summarized as follows: Fabrication process establishment of simulated DUPIC fuel for property measurement, Property model development for the DUPIC fuel, Performance evaluation of DUPIC fuel via irradiation test in Hanaro, Post irradiation examination of irradiated fuel and performance analysis, Development of DUPIC fuel performance code (KAOS)

  19. Dry process fuel performance technology development

    International Nuclear Information System (INIS)

    Kang, Kweon Ho; Kim, K. W.; Kim, B. K.

    2006-06-01

    The objective of the project is to establish the performance evaluation system of DUPIC fuel during the Phase III R and D. In order to fulfil this objectives, property model development of DUPIC fuel and irradiation test was carried out in Hanaro using the instrumented rig. Also, the analysis on the in-reactor behavior analysis of DUPIC fuel, out-pile test using simulated DUPIC fuel as well as performance and integrity assessment in a commercial reactor were performed during this Phase. The R and D results of the Phase III are summarized as follows: Fabrication process establishment of simulated DUPIC fuel for property measurement, Property model development for the DUPIC fuel, Performance evaluation of DUPIC fuel via irradiation test in Hanaro, Post irradiation examination of irradiated fuel and performance analysis, Development of DUPIC fuel performance code (KAOS)

  20. Entraining the Brain: Applications to Language Research and Links to Musical Entrainment

    Directory of Open Access Journals (Sweden)

    Usha Goswami

    2012-09-01

    Full Text Available Clayton’s paper provides a clear and accessible summary of the significance of entrainment for music making, and for human behaviour in general. He notes the central role of metrical structure in musical entrainment, the possible role of oscillatory neural activity, and the core notion of phase alignment. Here I show how these same factors are central to speech processing by the human brain. I argue that entrainment to metrical structure is core to linguistic as well as musical human behaviour. I illustrate this view using entrainment data from developmental dyslexia. The core role of entrainment in efficient speech processing suggests that language difficulties in childhood may benefit from music-based remediation that focuses on multi-modal rhythmic entrainment. Alignment of linguistic and musical metrical structure seems likely to be fundamental to successful remediation.

  1. Spent fuel storage process equipment development

    International Nuclear Information System (INIS)

    Park, Hyun Soo; Lee, Jae Sol; Yoo, Jae Hyung

    1990-02-01

    Nuclear energy which is a major energy source of national energy supply entails spent fuels. Spent fuels which are high level radioactive meterials, are tricky to manage and need high technology. The objectives of this study are to establish and develop key elements of spent fuel management technologies: handling equipment and maintenance, process automation technology, colling system, and cleanup system. (author)

  2. Thermochemical production of liquid fuels from biomass: Thermo-economic modeling, process design and process integration analysis

    International Nuclear Information System (INIS)

    Tock, Laurence; Gassner, Martin; Marechal, Francois

    2010-01-01

    A detailed thermo-economic model combining thermodynamics with economic analysis and considering different technological alternatives for the thermochemical production of liquid fuels from lignocellulosic biomass is presented. Energetic and economic models for the production of Fischer-Tropsch fuel (FT), methanol (MeOH) and dimethyl ether (DME) by means of biomass drying with steam or flue gas, directly or indirectly heated fluidized bed or entrained flow gasification, hot or cold gas cleaning, fuel synthesis and upgrading are reviewed and developed. The process is integrated and the optimal utility system is computed. The competitiveness of the different process options is compared systematically with regard to energetic, economic and environmental considerations. At several examples, it is highlighted that process integration is a key element that allows for considerably increasing the performance by optimal utility integration and energy conversion. The performance computations of some exemplary technology scenarios of integrated plants yield overall energy efficiencies of 59.8% (crude FT-fuel), 52.5% (MeOH) and 53.5% (DME), and production costs of 89, 128 and 113 Euro MWh -1 on fuel basis. The applied process design approach allows to evaluate the economic competitiveness compared to fossil fuels, to study the influence of the biomass and electricity price and to project for different plant capacities. Process integration reveals in particular potential energy savings and waste heat valorization. Based on this work, the most promising options for the polygeneration of fuel, power and heat will be determined in a future thermo-economic optimization.

  3. A Process for Evaluating Adverse Environmental Impacts by Cooling-Water System Entrainment at a California Power Plant

    Directory of Open Access Journals (Sweden)

    C.P. Ehrler

    2002-01-01

    Full Text Available A study to determine the effects of entrainment by the Diablo Canyon Power Plant (DCPP was conducted between 1996 and 1999 as required under Section 316(b of the Clean Water Act. The goal of this study was to present the U.S. Environmental Protection Agency (EPA and Central Coast Regional Water Quality Control Board (CCRWQCB with results that could be used to determine if any adverse environmental impacts (AEIs were caused by the operation of the plant’s cooling-water intake structure (CWIS. To this end we chose, under guidance of the CCRWQCB and their entrainment technical working group, a unique approach combining three different models for estimating power plant effects: fecundity hindcasting (FH, adult equivalent loss (AEL, and the empirical transport model (ETM. Comparisons of the results from these three approaches provided us a relative measure of confidence in our estimates of effects. A total of 14 target larval fish taxa were assessed as part of the DCPP 316(b. Example results are presented here for the kelp, gopher, and black-and-yellow (KGB rockfish complex and clinid kelpfish. Estimates of larval entrainment losses for KGB rockfish were in close agreement (FH is approximately equals to 550 adult females per year, AEL is approximately equals to 1,000 adults [male and female] per year, and ETM = larval mortality as high as 5% which could be interpreted as ca. 2,600 1 kg adult fish. The similar results from the three models provided confidence in the estimated effects for this group. Due to lack of life history information needed to parameterize the FH and AEL models, effects on clinid kelpfish could only be assessed using the ETM model. Results from this model plus ancillary information about local populations of adult kelpfish suggest that the CWIS might be causing an AEI in the vicinity of DCPP.

  4. Visual cortex entrains to sign language.

    Science.gov (United States)

    Brookshire, Geoffrey; Lu, Jenny; Nusbaum, Howard C; Goldin-Meadow, Susan; Casasanto, Daniel

    2017-06-13

    Despite immense variability across languages, people can learn to understand any human language, spoken or signed. What neural mechanisms allow people to comprehend language across sensory modalities? When people listen to speech, electrophysiological oscillations in auditory cortex entrain to slow ([Formula: see text]8 Hz) fluctuations in the acoustic envelope. Entrainment to the speech envelope may reflect mechanisms specialized for auditory perception. Alternatively, flexible entrainment may be a general-purpose cortical mechanism that optimizes sensitivity to rhythmic information regardless of modality. Here, we test these proposals by examining cortical coherence to visual information in sign language. First, we develop a metric to quantify visual change over time. We find quasiperiodic fluctuations in sign language, characterized by lower frequencies than fluctuations in speech. Next, we test for entrainment of neural oscillations to visual change in sign language, using electroencephalography (EEG) in fluent speakers of American Sign Language (ASL) as they watch videos in ASL. We find significant cortical entrainment to visual oscillations in sign language sign is strongest over occipital and parietal cortex, in contrast to speech, where coherence is strongest over the auditory cortex. Nonsigners also show coherence to sign language, but entrainment at frontal sites is reduced relative to fluent signers. These results demonstrate that flexible cortical entrainment to language does not depend on neural processes that are specific to auditory speech perception. Low-frequency oscillatory entrainment may reflect a general cortical mechanism that maximizes sensitivity to informational peaks in time-varying signals.

  5. Fuel corrosion processes under waste disposal conditions

    International Nuclear Information System (INIS)

    Shoesmith, D.W.

    2000-01-01

    The release of the majority of radionuclides from spent nuclear fuel under permanent disposal conditions will be controlled by the rate of dissolution of the UO 2 fuel matrix. In this manuscript the mechanism of the coupled anodic (fuel dissolution) and cathodic (oxidant reduction) reactions which constitute the overall fuel corrosion process is reviewed, and the many published observations on fuel corrosion under disposal conditions discussed. The primary emphasis is on summarizing the overall mechanistic behaviour and establishing the primary factors likely to control fuel corrosion. Included are discussions on the influence of various oxidants including radiolytic ones, pH, temperature, groundwater composition, and the formation of corrosion product deposits. The relevance of the data recorded on unirradiated UO 2 to the interpretation of spent fuel behaviour is included. Based on the review, the data used to develop fuel corrosion models under the conditions anticipated in Yucca Mountain (NV, USA) are evaluated

  6. Fuel quality processing study, volume 1

    Science.gov (United States)

    Ohara, J. B.; Bela, A.; Jentz, N. E.; Syverson, H. T.; Klumpe, H. W.; Kessler, R. E.; Kotzot, H. T.; Loran, B. L.

    1981-01-01

    A fuel quality processing study to provide a data base for an intelligent tradeoff between advanced turbine technology and liquid fuel quality, and also, to guide the development of specifications of future synthetic fuels anticipated for use in the time period 1985 to 2000 is given. Four technical performance tests are discussed: on-site pretreating, existing refineries to upgrade fuels, new refineries to upgrade fuels, and data evaluation. The base case refinery is a modern Midwest refinery processing 200,000 BPD of a 60/40 domestic/import petroleum crude mix. The synthetic crudes used for upgrading to marketable products and turbine fuel are shale oil and coal liquids. Of these syncrudes, 50,000 BPD are processed in the existing petroleum refinery, requiring additional process units and reducing petroleum feed, and in a new refinery designed for processing each syncrude to produce gasoline, distillate fuels, resid fuels, and turbine fuel, JPGs and coke. An extensive collection of synfuel properties and upgrading data was prepared for the application of a linear program model to investigate the most economical production slate meeting petroleum product specifications and turbine fuels of various quality grades. Technical and economic projections were developed for 36 scenarios, based on 4 different crude feeds to either modified existing or new refineries operated in 2 different modes to produce 7 differing grades of turbine fuels. A required product selling price of turbine fuel for each processing route was calculated. Procedures and projected economics were developed for on-site treatment of turbine fuel to meet limitations of impurities and emission of pollutants.

  7. Manufacturing technology and process for BWR fuel

    International Nuclear Information System (INIS)

    Kato, Shigeru

    1996-01-01

    Following recent advanced technologies, processes and requests of the design changes of BWR fuel, Nuclear Fuel Industries, Ltd. (NFI) has upgraded the manufacturing technology and honed its own skills to complete its brand-new automated facility in Tokai in the latter half of 1980's. The plant uses various forms of automation throughout the manufacturing process: the acceptance of uranium dioxide powder, pelletizing, fuel rod assembling, fuel bundle assembling and shipment. All processes are well computerized and linked together to establish the integrated control system with three levels of Production and Quality Control, Process Control and Process Automation. This multi-level system plays an important role in the quality assurance system which generates the highest quality of fuels and other benefits. (author)

  8. Nano-engineered ZnO/CeO2 dots@CNFs for fuel cell application

    Directory of Open Access Journals (Sweden)

    Zafar Khan Ghouri

    2016-03-01

    Full Text Available Well-dispersed ZnO(xCeO2(1−x nanodots@carbon nanofibers as anode catalysts for the electrooxidation of methanol were synthesized by an easy-controlled template-free method. Their structure and morphology were characterized by X-ray diffraction (XRD, high resolution transmission electron microscopy (HR-TEM, field-emission scanning electron microscopy (FESEM equipped with rapid EDX (energy dispersive analysis of X-ray. The appealed characterization techniques specified that the obtained material is carbon nanofibers decorated by ZnO and CeO2 nanodots. The electrochemical oxidation of methanol on ZnO(xCeO2(1−x nanodots@CNFs modified glassy carbon electrode in alkaline solutions was systematically evaluated by cyclic voltammetry (CV method. A detailed investigation is made for the electrocatalytic oxidation of methanol by varying methanol concentration. The corresponding current densities of ZnO(60%CeO2(40% nanodots@CNFs and ZnO(40%CeO2(60% nanodots@CNFs were 5.3 and 16.3 mA/cm2, respectively. Moreover, negative onset potential (−50 mV vs. Ag/AgCl was observed when ZnO(40%CeO2(60% nanodots@CNFs were utilized, which is a superior value among the reported non-precious electrocatalysts. These results suggested cheap and effective nanomaterials as non-precious catalyst for DMFCs application and pave the way to further improve the performance in energy and environmental applications.

  9. A spectrophotometric study of cerium IV and chromium VI species in nuclear fuel reprocessing process streams

    International Nuclear Information System (INIS)

    Nickson, I D; Boxall, C; Jackson, A; Whillock, G O H

    2010-01-01

    Nuclear fuel reprocessing schemes such as PUREX and UREX utilise HNO 3 media. An understanding of the corrosion of process engineering materials such as stainless steel in such media is a major concern for the nuclear industry. Two key species are cerium and chromium which, as Ce(IV), Cr(VI), may act as corrosion accelerants. An on-line analytical technique for these quantities would be useful for determining the relationship between corrosion rate and [Ce(IV)] and [Cr(VI)]. Consequently, a strategy for simultaneous quantification of Ce(IV), Cr(VI) and Cr(III) in the presence of other ions found in average burn-up Magnox / PWR fuel reprocessing stream (Fe, Mg, Nd, Al) is being developed. This involves simultaneous UV-vis absorbance measurement at 620, 540, 450 nm, wavelengths where Ce and Cr absorb but other ions do not. Mixed solutions of Cr(VI) and Ce(IV) are found to present higher absorbance values at 540 nm than those predicted from absorbances recorded from single component solutions of those ions. This is attributed to the formation of a 3:1 Cr(VI)-Ce(IV) complex and we report on the complexation and UV-visible spectrophotometric characteristics of this species. To the best of our knowledge this is the first experimental study of this complex in aqueous nitric acid solution systems.

  10. Entrainment separator performance

    International Nuclear Information System (INIS)

    First, M.W.; Leith, D.

    1976-01-01

    Clean and dust-loaded ACS entrainment separators mounted upstream of HEPA filters were exposed to a combination of fine water mist and steam at about 70 0 C from one to four hours. In every trial, the ACS entrainment separator prevented measurable deterioration of performance in the following HEPA filter. Droplet size-efficiency evaluation of the ACS entrainment separators showed that, within the accuracy of the measurements, they meet all service requirements and are fully equal to the best separator units available for service on pressurized water reactors

  11. Fuel processing requirements and techniques for fuel cell propulsion power

    Science.gov (United States)

    Kumar, R.; Ahmed, S.; Yu, M.

    Fuels for fuel cells in transportation systems are likely to be methanol, natural gas, hydrogen, propane, or ethanol. Fuels other than hydrogen will need to be reformed to hydrogen on-board the vehicle. The fuel reformer must meet stringent requirements for weight and volume, product quality, and transient operation. It must be compact and lightweight, must produce low levels of CO and other byproducts, and must have rapid start-up and good dynamic response. Catalytic steam reforming, catalytic or noncatalytic partial oxidation reforming, or some combination of these processes may be used. This paper discusses salient features of the different kinds of reformers and describes the catalysts and processes being examined for the oxidation reforming of methanol and the steam reforming of ethanol. Effective catalysts and reaction conditions for the former have been identified; promising catalysts and reaction conditions for the latter are being investigated.

  12. Powder handling for automated fuel processing

    International Nuclear Information System (INIS)

    Frederickson, J.R.; Eschenbaum, R.C.; Goldmann, L.H.

    1989-01-01

    Installation of the Secure Automated Fabrication (SAF) line has been completed. It is located in the Fuel Cycle Plant (FCP) at the Department of Energy's (DOE) Hanford site near Richland, Washington. The SAF line was designed to fabricate advanced reactor fuel pellets and assemble fuel pins by automated, remote operation. This paper describes powder handling equipment and techniques utilized for automated powder processing and powder conditioning systems in this line. 9 figs

  13. Physical Properties of Mixed Conductor Solid Oxide Fuel Cell Anodes of Doped CeO2

    DEFF Research Database (Denmark)

    Mogensen, Mogens Bjerg; Lindegaard, Thomas; Hansen, Uffe Rud

    1994-01-01

    Samples of CeO2 doped with oxides such as CaO and Gd2O3 were prepared. Their conductivities and expansions onreduction were measured at 1000°C, and the thermal expansion coefficients in the range 50 to 1000°C were determined. Theionic and electronic conductivity were derived from curves of total ...

  14. Large Eddy and Interface Simulation (LEIS) of liquid entrainment in turbulent stratified flow

    International Nuclear Information System (INIS)

    Gulati, S.; Buongiorno, J.; Lakehal, D.

    2011-01-01

    Dryout of the liquid film on the fuel rods in BWR fuel assemblies leads to an abrupt decrease in heat transfer coefficient and can result in fuel failure. The process of mechanical mass transfer from the continuous liquid field into the continuous vapor field along the liquid-vapor interface is called entrainment and is the dominant depletion mechanism for the liquid film in annular flow. Using interface tracking methods combined with a Large Eddy Simulation approach, implemented in the Computational Multi-Fluid Dynamics (CMFD) code TransAT®, we are studying entrainment phenomena in BWR fuel assemblies. In this paper we report on the CMFD simulation approaches and the current validation effort for the code. (author)

  15. Mathematical modeling of biomass fuels formation process

    International Nuclear Information System (INIS)

    Gaska, Krzysztof; Wandrasz, Andrzej J.

    2008-01-01

    The increasing demand for thermal and electric energy in many branches of industry and municipal management accounts for a drastic diminishing of natural resources (fossil fuels). Meanwhile, in numerous technical processes, a huge mass of wastes is produced. A segregated and converted combustible fraction of the wastes, with relatively high calorific value, may be used as a component of formed fuels. The utilization of the formed fuel components from segregated groups of waste in associated processes of co-combustion with conventional fuels causes significant savings resulting from partial replacement of fossil fuels, and reduction of environmental pollution resulting directly from the limitation of waste migration to the environment (soil, atmospheric air, surface and underground water). The realization of technological processes with the utilization of formed fuel in associated thermal systems should be qualified by technical criteria, which means that elementary processes as well as factors of sustainable development, from a global viewpoint, must not be disturbed. The utilization of post-process waste should be preceded by detailed technical, ecological and economic analyses. In order to optimize the mixing process of fuel components, a mathematical model of the forming process was created. The model is defined as a group of data structures which uniquely identify a real process and conversion of this data in algorithms based on a problem of linear programming. The paper also presents the optimization of parameters in the process of forming fuels using a modified simplex algorithm with a polynomial worktime. This model is a datum-point in the numerical modeling of real processes, allowing a precise determination of the optimal elementary composition of formed fuels components, with assumed constraints and decision variables of the task

  16. Microwave processing in MOX fuel cycle

    International Nuclear Information System (INIS)

    Mallik, G.K.; Malav, R.K.; Panakkal, J.P.; Kamath, H.S.

    2005-01-01

    The prominent aspect of the microwave heating technique applications in nuclear material processing is its eco-friendly status. It is envisaged that no active liquid waste will be generated from microwave processing. AFFF has fabricated the (U, Pu) 2 O mixed oxide fuels for PHWRs, BWRs and PFBR. AFFF is also working for the AHWR fuel cycle. The present paper summarises about the process experiments, instrumental development, results, and future applications of microwave heating technique. (author)

  17. Chemical aspects of nuclear fuel fabrication processes

    Energy Technology Data Exchange (ETDEWEB)

    Naylor, A; Ellis, J F; Watson, R H

    1986-04-01

    Processes used by British Nuclear Fuels plc for the conversion of uranium ore concentrates to uranium metal and uranium hexafluoride, are reviewed. Means of converting the latter compound, after enrichment, to sintered UO/sub 2/ fuel bodies are also described. An overview is given of the associated chemical engineering technology.

  18. Fuel corrosion processes under waste disposal conditions

    International Nuclear Information System (INIS)

    Shoesmith, D.W.

    1999-09-01

    Under the oxidizing conditions likely to be encountered in the Yucca Mountain Repository, fuel dissolution is a corrosion process involving the coupling of the anodic dissolution of the fuel with the cathodic reduction of oxidants available within the repository. The oxidants potentially available to drive fuel corrosion are environmental oxygen, supplied by the transport through the permeable rock of the mountain and molecular and radical species produced by the radiolysis of available aerated water. The mechanism of these coupled anodic and cathodic reactions is reviewed in detail. While gaps in understanding remain, many kinetic features of these reactions have been studied in considerable detail, and a reasonably justified mechanism for fuel corrosion is available. The corrosion rate is determined primarily by environmental factors rather than the properties of the fuel. Thus, with the exception of increase in rate due to an increase in surface area, pre-oxidation of the fuel has little effect on the corrosion rate

  19. Fuel corrosion processes under waste disposal conditions

    Energy Technology Data Exchange (ETDEWEB)

    Shoesmith, D.W. [Univ. of Western Ontario, Dept. of Chemistry, London, Ontario (Canada)

    1999-09-01

    Under the oxidizing conditions likely to be encountered in the Yucca Mountain Repository, fuel dissolution is a corrosion process involving the coupling of the anodic dissolution of the fuel with the cathodic reduction of oxidants available within the repository. The oxidants potentially available to drive fuel corrosion are environmental oxygen, supplied by the transport through the permeable rock of the mountain and molecular and radical species produced by the radiolysis of available aerated water. The mechanism of these coupled anodic and cathodic reactions is reviewed in detail. While gaps in understanding remain, many kinetic features of these reactions have been studied in considerable detail, and a reasonably justified mechanism for fuel corrosion is available. The corrosion rate is determined primarily by environmental factors rather than the properties of the fuel. Thus, with the exception of increase in rate due to an increase in surface area, pre-oxidation of the fuel has little effect on the corrosion rate.

  20. Fuel processing for molten-salt reactors

    International Nuclear Information System (INIS)

    Hightower, J.R. Jr.

    1976-01-01

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

  1. Reflooding phase of the LOCA in PWRs. Part II: rewetting and liquid entrainment

    International Nuclear Information System (INIS)

    Elias, E.; Yadigaroglu, G.

    1978-01-01

    Surface rewetting and liquid-droplet entrainment play an important role in the analysis of the reflooding phase of the loss-of-coolant accident in pressurized-water reactors. The definitions and the various interpretations given to the rewetting temperature and the rewetting mechanisms of the fuel rods are discussed. Published models of the axial-conduction-controlled rewetting process include one-dimensional solutions in two axial regions, one-dimensional solutions in three axial regions with or without precursory cooling, one- and two-dimensional numerical-difference techniques using temperature-dependent heat-transfer coefficients, and analytical two-dimensional solutions. The basic physical assumptions and the numerical values assigned to the various parameters, as well as empirical rewetting correlations, are discussed. The physical mechanisms for liquid-droplet entrainment and analytical formulations of the critical gas velocity and of the droplet diameter at the onset of entrainment are reviewed

  2. Process for producing nuclear reactor fuel oxides

    International Nuclear Information System (INIS)

    Goenrich, H.; Druckenbrodt, W.G.

    1981-01-01

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

  3. Cloud-Top Entrainment in Stratocumulus Clouds

    Science.gov (United States)

    Mellado, Juan Pedro

    2017-01-01

    Cloud entrainment, the mixing between cloudy and clear air at the boundary of clouds, constitutes one paradigm for the relevance of small scales in the Earth system: By regulating cloud lifetimes, meter- and submeter-scale processes at cloud boundaries can influence planetary-scale properties. Understanding cloud entrainment is difficult given the complexity and diversity of the associated phenomena, which include turbulence entrainment within a stratified medium, convective instabilities driven by radiative and evaporative cooling, shear instabilities, and cloud microphysics. Obtaining accurate data at the required small scales is also challenging, for both simulations and measurements. During the past few decades, however, high-resolution simulations and measurements have greatly advanced our understanding of the main mechanisms controlling cloud entrainment. This article reviews some of these advances, focusing on stratocumulus clouds, and indicates remaining challenges.

  4. Investigations of gas entrainment in KNK II

    International Nuclear Information System (INIS)

    Hoppe, P.; Massier, H.; Mitzel, F.; Vaeth, W.

    1979-08-01

    During commissioning of KNK II operational difficulties were encountered due to gas entrainment in the coolant. This gas entrainment caused negative reactivity fluctuations which tripped the reactor repeatedly. Since first investigations indicated one main cause of the gas entrainment and the existence of an accumulation process, a technical modification (installation of a throttle valve) for remedy was performed. This report describes the investigations made after the plant modification. The main objective was to test the effectiveness of the modifications and to look into the following still open problems: Localization of the gas storage, detection and estimation of a permanent gas entrainment and the analysis of positive power overshoots being observed in connection with the gas bubbles

  5. Exploring Entrainment Patterns of Human Emotion in Social Media

    Science.gov (United States)

    Luo, Chuan; Zhang, Zhu

    2016-01-01

    Emotion entrainment, which is generally defined as the synchronous convergence of human emotions, performs many important social functions. However, what the specific mechanisms of emotion entrainment are beyond in-person interactions, and how human emotions evolve under different entrainment patterns in large-scale social communities, are still unknown. In this paper, we aim to examine the massive emotion entrainment patterns and understand the underlying mechanisms in the context of social media. As modeling emotion dynamics on a large scale is often challenging, we elaborate a pragmatic framework to characterize and quantify the entrainment phenomenon. By applying this framework on the datasets from two large-scale social media platforms, we find that the emotions of online users entrain through social networks. We further uncover that online users often form their relations via dual entrainment, while maintain it through single entrainment. Remarkably, the emotions of online users are more convergent in nonreciprocal entrainment. Building on these findings, we develop an entrainment augmented model for emotion prediction. Experimental results suggest that entrainment patterns inform emotion proximity in dyads, and encoding their associations promotes emotion prediction. This work can further help us to understand the underlying dynamic process of large-scale online interactions and make more reasonable decisions regarding emergency situations, epidemic diseases, and political campaigns in cyberspace. PMID:26953692

  6. Exploring Entrainment Patterns of Human Emotion in Social Media.

    Science.gov (United States)

    He, Saike; Zheng, Xiaolong; Zeng, Daniel; Luo, Chuan; Zhang, Zhu

    2016-01-01

    Emotion entrainment, which is generally defined as the synchronous convergence of human emotions, performs many important social functions. However, what the specific mechanisms of emotion entrainment are beyond in-person interactions, and how human emotions evolve under different entrainment patterns in large-scale social communities, are still unknown. In this paper, we aim to examine the massive emotion entrainment patterns and understand the underlying mechanisms in the context of social media. As modeling emotion dynamics on a large scale is often challenging, we elaborate a pragmatic framework to characterize and quantify the entrainment phenomenon. By applying this framework on the datasets from two large-scale social media platforms, we find that the emotions of online users entrain through social networks. We further uncover that online users often form their relations via dual entrainment, while maintain it through single entrainment. Remarkably, the emotions of online users are more convergent in nonreciprocal entrainment. Building on these findings, we develop an entrainment augmented model for emotion prediction. Experimental results suggest that entrainment patterns inform emotion proximity in dyads, and encoding their associations promotes emotion prediction. This work can further help us to understand the underlying dynamic process of large-scale online interactions and make more reasonable decisions regarding emergency situations, epidemic diseases, and political campaigns in cyberspace.

  7. Exploring Entrainment Patterns of Human Emotion in Social Media.

    Directory of Open Access Journals (Sweden)

    Saike He

    Full Text Available Emotion entrainment, which is generally defined as the synchronous convergence of human emotions, performs many important social functions. However, what the specific mechanisms of emotion entrainment are beyond in-person interactions, and how human emotions evolve under different entrainment patterns in large-scale social communities, are still unknown. In this paper, we aim to examine the massive emotion entrainment patterns and understand the underlying mechanisms in the context of social media. As modeling emotion dynamics on a large scale is often challenging, we elaborate a pragmatic framework to characterize and quantify the entrainment phenomenon. By applying this framework on the datasets from two large-scale social media platforms, we find that the emotions of online users entrain through social networks. We further uncover that online users often form their relations via dual entrainment, while maintain it through single entrainment. Remarkably, the emotions of online users are more convergent in nonreciprocal entrainment. Building on these findings, we develop an entrainment augmented model for emotion prediction. Experimental results suggest that entrainment patterns inform emotion proximity in dyads, and encoding their associations promotes emotion prediction. This work can further help us to understand the underlying dynamic process of large-scale online interactions and make more reasonable decisions regarding emergency situations, epidemic diseases, and political campaigns in cyberspace.

  8. Ultra-Deep Adsorptive Desulfurization of Light-Irradiated Diesel Fuel over Supported TiO2-CeO2 Adsorbents

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Jing; Wang, Xiaoxing; Chen, Yongsheng; Fujii, Mamoru; Song, Chunshan [SCUT-China; (Penn)

    2014-02-13

    This study investigates ultra-deep adsorptive desulfurization (ADS) from light-irradiated diesel fuel over supported TiO2CeO2 adsorbents. A 30-fold higher desulfurization capacity of 95 mL of fuel per gram of adsorbent (mL-F/g-sorb) or 1.143 mg of sulfur per gram of adsorbent (mg-S/g-sorb) was achieved from light-irradiated fuel over the original low-sulfur fuel containing about 15 ppm by weight (ppmw) of sulfur. The sulfur species on spent TiO2CeO2/MCM-48 adsorbent was identified by sulfur K-edge XANES as sulfones and the adsorption selectivity to different compounds tested in a model fuel decreases in the order of indole > dibenzothiophenesulfone → dibenzothiophene > 4-methyldibenzothiophene > benzothiophene > 4,6-dimethyldibenzothiophene > phenanthrene > 2-methylnaphthalene ~ fluorene > naphthalene. The results suggest that during ADS of light-irradiated fuel, the original sulfur species were chemically transformed to sulfones, resulting in the significant increase in desulfurization capacity. For different supports for TiO2–CeO2 oxides, the ADS capacity increases with a decrease in the point of zero charge (PZC) value; for silica-supported TiO2CeO2 oxides (the lowest PZC value of 2–4) with different surface areas, the ADS capacity increases monotonically with increasing surface area. The supported TiO2CeO2/MCM-48 adsorbent can be regenerated using oxidative air treatment. The present study provides an attractive new path to achieve ultraclean fuel more effectively.

  9. How can we describe the entrainment processes in sheared convective boundary layers?: a large-eddy simulation and mixed-layer theory/model comparison study

    NARCIS (Netherlands)

    Pino, D.; Vilà-Guerau de Arellano, J.; Kim, S.W.

    2006-01-01

    Dry convective boundary layers characterized by a significant wind shear on the surface and at the inversion zone are studied by means of the mixed layer theory. Two different representations of the entrainment zone, each of which has a different closure of the entrainment heat flux, are considered.

  10. Nanoporous silver cathode surface treated by atomic layer deposition of CeO_x for low-temperature solid oxide fuel cells

    International Nuclear Information System (INIS)

    Neoh, Ke Chean; Han, Gwon Deok; Kim, Manjin; Kim, Jun Woo; Choi, Hyung Jong; Park, Suk Won; Shim, Joon Hyung

    2016-01-01

    We evaluated the performance of solid oxide fuel cells (SOFCs) with a 50 nm thin silver (Ag) cathode surface treated with cerium oxide (CeO_x) by atomic layer deposition (ALD). The performances of bare and ALD-treated Ag cathodes were evaluated on gadolinia-doped ceria (GDC) electrolyte supporting cells with a platinum (Pt) anode over 300 °C–450 °C. Our work confirms that ALD CeO_x treatment enhances cathodic performance and thermal stability of the Ag cathode. The performance difference between cells using a Ag cathode optimally treated with an ALD CeO_x surface and a reference Pt cathode is about 50% at 450 °C in terms of fuel cell power output in our experiment. The bare Ag cathode completely agglomerated into islands during fuel cell operation at 450 °C, while the ALD CeO_x treatment effectively protects the porosity of the cathode. We also discuss the long-term stability of ALD CeO_x-treated Ag cathodes related to the microstructure of the layers. (paper)

  11. Process to produce homogenized reactor fuels

    International Nuclear Information System (INIS)

    Hart, P.E.; Daniel, J.L.; Brite, D.W.

    1980-01-01

    The fuels consist of a mixture of PuO 2 and UO 2 . In order to increase the homogeneity of mechanically mixed fuels the pellets are sintered in a hydrogen atmosphere with a sufficiently low oxygen potential. This results in a reduction of Pu +4 to Pu +3 . By the reduction process water vapor is obtained increasing the pressure within the PuO 2 particles and causing PuO 2 to be pressed into the uranium oxide structure. (DG) [de

  12. Pyrochemical processing of DOE spent nuclear fuel

    International Nuclear Information System (INIS)

    Laidler, J.J.

    1995-01-01

    A compact, efficient method for conditioning spent nuclear fuel is under development. This method, known as pyrochemical processing, or open-quotes pyroprocessing,close quotes provides a separation of fission products from the actinide elements present in spent fuel and further separates pure uranium from the transuranic elements. The process can facilitate the timely and environmentally-sound treatment of the highly diverse collection of spent fuel currently in the inventory of the United States Department of Energy (DOE). The pyroprocess utilizes elevated-temperature processes to prepare spent fuel for fission product separation; that separation is accomplished by a molten salt electrorefining step that provides efficient (>99.9%) separation of transuranics. The resultant waste forms from the pyroprocess, are stable under envisioned repository environment conditions and highly leach-resistant. Treatment of any spent fuel type produces a set of common high-level waste forms, one a mineral and the other a metal alloy, that can be readily qualified for repository disposal and avoid the substantial costs that would be associated with the qualification of the numerous spent fuel types included in the DOE inventory

  13. Development of advanced spent fuel management process. System analysis of advanced spent fuel management process

    International Nuclear Information System (INIS)

    Ro, S.G.; Kang, D.S.; Seo, C.S.; Lee, H.H.; Shin, Y.J.; Park, S.W.

    1999-03-01

    The system analysis of an advanced spent fuel management process to establish a non-proliferation model for the long-term spent fuel management is performed by comparing the several dry processes, such as a salt transport process, a lithium process, the IFR process developed in America, and DDP developed in Russia. In our system analysis, the non-proliferation concept is focused on the separation factor between uranium and plutonium and decontamination factors of products in each process, and the non-proliferation model for the long-term spent fuel management has finally been introduced. (Author). 29 refs., 17 tabs., 12 figs

  14. Method for processing spent nuclear reactor fuel

    International Nuclear Information System (INIS)

    Levenson, M.; Zebroski, E.L.

    1981-01-01

    A method and apparatus are claimed for processing spent nuclear reactor fuel wherein plutonium is continuously contaminated with radioactive fission products and diluted with uranium. Plutonium of sufficient purity to fabricate nuclear weapons cannot be produced by the process or in the disclosed reprocessing plant. Diversion of plutonium is prevented by radiation hazards and ease of detection

  15. Brazing process in nuclear fuel element fabrication

    International Nuclear Information System (INIS)

    Katam, K.; Sudarsono

    1982-01-01

    The purpose of the brazing process is to join the spacers and pads of fuel pins, so that the process is meant as a soldering technique and not only as a hardening or reinforcing process such as in common brazing purposes. There are some preliminary processes before executing the brazing process such as: materials preparation, sand blasting, brazing metal coating tack welding the spacers and pads on the fuel cladding. The metal brazing used is beryllium in strip form which will be evaporated in vacuum condition to coat the spacers and pads. The beryllium vapor and dust is very hazardous to the workers, so all the line process of brazing needs specials safety protection and equipment to protect the workers and the processing area. Coating process temperature is 2470 deg C with a vacuum pressure of 10 -5 mmHg. Brazing process temperature process is 1060 deg C with a vacuum pressure of 10 -6 mmHg. The brazing process with beryllium coating probably will give metallurgical structural change in the fuel cladding metal at the locations of spacers and pads. The quality of brazing is highly influenced by and is depending on the chemical composition of the metal and the brazing metal, materials preparations, temperature, vacuum pressure, time of coating and brazing process. The quality control of brazing could be performed with methods of visuality geometry, radiography and metallography. (author)

  16. Development of advanced spent fuel management process

    International Nuclear Information System (INIS)

    Park, Seong Won; Shin, Y. J.; Cho, S. H.

    2004-03-01

    The research on spent fuel management focuses on the maximization of the disposal efficiency by a volume reduction, the improvement of the environmental friendliness by the partitioning and transmutation of the long lived nuclides, and the recycling of the spent fuel for an efficient utilization of the uranium source. In the second phase which started in 2001, the performance test of the advanced spent fuel management process consisting of voloxidation, reduction of spent fuel and the lithium recovery process has been completed successfully on a laboratory scale. The world-premier spent fuel reduction hot test of a 5 kgHM/batch has been performed successfully by joint research with Russia and the valuable data on the actinides and FPs material balance and the characteristics of the metal product were obtained with experience to help design an engineering scale reduction system. The electrolytic reduction technology which integrates uranium oxide reduction in a molten LiCl-Li 2 O system and Li 2 O electrolysis is developed and a unique reaction system is also devised. Design data such as the treatment capacity, current density and mass transfer behavior obtained from the performance test of a 5 kgU/batch electrolytic reduction system pave the way for the third phase of the hot cell demonstration of the advanced spent fuel management technology

  17. Holistic analysis of thermochemical processes by using solid biomass for fuel production in Germany

    International Nuclear Information System (INIS)

    Henssler, Martin

    2015-01-01

    According to the German act ''Biokraftstoff-Nachhaltigkeitsverordnung'', biofuels must show a CO 2eq -reduction compared to the fossil reference fuel (83.8 g CO 2eq /MJ fuel /Richtlinie 98/70/EG/) of 35 % beginning with 2011. In new plants, which go into operation after the 31.12.2016 the CO 2eq -savings must be higher than 50 % in 2017 and higher than 60 % in 2018 /Biokraft-NachV/. The biofuels (methyl ester of rapeseed, bioethanol and biomethane) considered in this study do not meet these requirements for new plants. To comply with these rules new processes must be deployed. Alternative thermochemical generated fuels could be an option. The aim of this work is to evaluate through a technical, ecological and economic analysis (Well-to-Wheel) whether and under what conditions the thermochemical production of Fischer-Tropsch-diesel or -gasoline, hydrogen (H 2 ) and Substitute Natural Gas (SNG) complies with the targets. Four different processes are considered (fast pyrolysis and torrefaction with entrained flow gasifier, CHOREN Carbo-V registered -gasifier, Absorption Enhanced Reforming (AER-) gasifier). Beside residues such as winter wheat straw and residual forest wood, wood from short-rotation plantations is taken into account. The technical analysis showed that at present status (2010) two and in 2050 six plants can be operated energy-self-sufficient. The overall efficiency of the processes is in the range of 41.5 (Fischer-Tropsch-diesel or -gasoline) and 59.4 % (H 2 ). Furthermore, it was found that for 2010, all thermochemical produced fuels except the H 2 -production from wood from short-rotation plantations in decentralised or central fast pyrolysis and in decentralised torrefactions with entrained flow gasifier keep the required CO 2eq -saving of 60 %. In 2050, all thermochemical produced fuels will reach these limits. The CO 2eq -saving is between 72 (H 2 ) and 95 % (Fischer-Tropsch-diesel or -gasoline). When the production costs of the

  18. Development of advanced spent fuel management process

    International Nuclear Information System (INIS)

    Shin, Young Joon; Cho, S. H.; You, G. S.

    2001-04-01

    Currently, the economic advantage of any known approach to the back end fuel cycle of a nuclear power reactor has not been well established. Thus the long term storage of the spent fuel in a safe manner is one of the important issues to be resolved in countries where the nuclear power has a relatively heavy weight in power production of that country. At KAERI, as a solution to this particular issue midterm storage of the spent fuel, an alternative approach has been developed. This approach includes the decladding and pulverization process of the spent PWR fuel rod, the reducing process from the uranium oxide to a metallic uranium powder using Li metal in a LiCl salt, the continuous casting process of the reduced metal, and the recovery process of Li from mixed salts by the electrolysis. We conducted the laboratory scale tests of each processes for the technical feasibility and determination for the operational conditions for this approach. Also, we performed the theoretical safety analysis and conducted integral tests for the equipment integration through the Mock-up facility with non-radioactive samples. There were no major issues in the approach, however, material incompatibility of the alkaline metal and oxide in a salt at a high temperature and the reactor that contains the salt became a show stopper of the process. Also the difficulty of the clear separation of the salt with metals reduced from the oxide became a major issue

  19. Study of resolution and linearity in LaBr3: Ce scintillator through digital-pulse processing

    International Nuclear Information System (INIS)

    Abhinav Kumar; Mishra, Gaurav; Ramachandran, K.

    2014-01-01

    Advent of digital pulse processing has led to a paradigm shift in pulse processing techniques by replacing analog electronics processing chain with equivalent algorithms acting on pulse profiles digitized at high sampling rates. In this paper, we have carried out offline digital pulse processing of Cerium-doped Lanthanum bromide scintillator (LaBr 3 : Ce) detector pulses, acquired using CAEN V1742 VME digitizer module. Algorithms have been written to approximate the functioning of peak sensing analog-to-digital convertor (ADC) and charge-to-digital convertor (QDC). Energy dependence of resolution and energy linearity of LaBr 3 : Ce scintillator detector has been studied by utilizing aforesaid algorithms

  20. A robust NiO-Sm0.2Ce0.8O1.9 anode for direct-methane solid oxide fuel cell

    KAUST Repository

    Tian, Dong

    2015-07-02

    In order to directly use methane without a reforming process, NiO-Sm0.2Ce0.8O1.9 (NiO-SDC) nanocomposite anode are successfully synthesized via a one-pot, surfactant-assisted co-assembly approach for direct-methane solid oxide fuel cells. Both NiO with cubic phase and SDC with fluorite phase are obtained at 550 °C. Both NiO nanoparticles and SDC nanoparticles are highly monodispersed in size with nearly spherical shapes. Based on the as-synthesized NiO-SDC, two kinds of single cells with different micro/macro-porous structure are successfully fabricated. As a result, the cell performance was improved by 40%-45% with the new double-pore NiO-SDC anode relative to the cell performance with the conventional NiO-SDC anode due to a wider triple-phase-boundary (TPB) area. In addition, no significant degradation of the cell performance was observed after 60 hours, which means an increasing of long term stability. Therefore, the as-synthesized NiO-SDC nanocomposite is a promising anode for direct-methane solid oxide fuel cells.

  1. Development of advanced spent fuel management process

    International Nuclear Information System (INIS)

    Ro, Seung Gy; Shin, Y. J.; Do, J. B.; You, G. S.; Seo, J. S.; Lee, H. G.

    1998-03-01

    This study is to develop an advanced spent fuel management process for countries which have not yet decided a back-end nuclear fuel cycle policy. The aims of this process development based on the pyroreduction technology of PWR spent fuels with molten lithium, are to reduce the storage volume by a quarter and to reduce the storage cooling load in half by the preferential removal of highly radioactive decay-heat elements such as Cs-137 and Sr-90 only. From the experimental results which confirm the feasibility of metallization technology, it is concluded that there are no problems in aspects of reaction kinetics and equilibrium. However, the operating performance test of each equipment on an engineering scale still remain and will be conducted in 1999. (author). 21 refs., 45 tabs., 119 figs

  2. Review on Fuel Loading Process and Performance for Advanced Fuel Handling Equipment

    International Nuclear Information System (INIS)

    Chang, Sang-Gyoon; Lee, Dae-Hee; Kim, Young-Baik; Lee, Deuck-Soo

    2007-01-01

    The fuel loading process and the performance of the advanced fuel handling equipment for OPR 1000 (Optimized Power Plant) are analyzed and evaluated. The fuel handling equipment, which acts critical processes in the refueling outage, has been improved to reduce fuel handling time. The analysis of the fuel loading process can be a useful tool to improve the performance of the fuel handling equipment effectively. Some recommendations for further improvement are provided based on this study

  3. Performance of entrained flow and fluidised bed biomass gasifiers on different scales

    International Nuclear Information System (INIS)

    Tremel, Alexander; Becherer, Dominik; Fendt, Sebastian; Gaderer, Matthias; Spliethoff, Hartmut

    2013-01-01

    Highlights: ► Gasification of biomass in fluidised bed and entrained flow reactors is modelled. ► The systems are evaluated for a thermal input from 10 MW to 500 MW. ► Special attention is given to the preconditioning methods for biomass. ► Fluidised bed and entrained flow gasifiers are compared in terms of efficiency and costs. - Abstract: This biomass gasification process study compares the energetic and economic efficiencies of a dual fluidised bed and an oxygen-blown entrained flow gasifier from 10 MW th to 500 MW th . While fluidised bed gasification became the most applied technology for biomass in small and medium scale facilities, entrained flow gasification technology is still used exclusively for industrial scale coal gasification. Therefore, it is analysed whether and for which capacity the entrained flow technology is an energetically and economically efficient option for the thermo-chemical conversion of biomass. Special attention is given to the pre-conditioning methods for biomass to enable the application in an entrained flow gasifier. Process chains are selected for the two gasifier types and subsequently transformed to simulation models. The simulation results show that the performance of both gasifier types is similar for the production of a pressurised product gas (2.5 MPa). The cold gas efficiency of the fluidised bed is 76–79% and about 0.5–2 percentage points higher than for the entrained flow reactor. The net efficiencies of both technologies are similar and between 64% and 71% depending on scale. The auxiliary power consumption of the entrained flow reactor is caused mainly by the air separation unit, the oxygen compression, and the fuel pulverisation, whereas the fluidised bed requires additional power mainly for gas compression. The costs for the product gas are determined as between €4.2 cent/kWh (500 MW th ) and €7.4 cent/kWh (10 MW th ) in the economic analysis of both technologies. The study indicates that the

  4. Alternative Fuel for Portland Cement Processing

    Energy Technology Data Exchange (ETDEWEB)

    Schindler, Anton K; Duke, Steve R; Burch, Thomas E; Davis, Edward W; Zee, Ralph H; Bransby, David I; Hopkins, Carla; Thompson, Rutherford L; Duan, Jingran; ; Venkatasubramanian, Vignesh; Stephen, Giles

    2012-06-30

    The production of cement involves a combination of numerous raw materials, strictly monitored system processes, and temperatures on the order of 1500 °C. Immense quantities of fuel are required for the production of cement. Traditionally, energy from fossil fuels was solely relied upon for the production of cement. The overarching project objective is to evaluate the use of alternative fuels to lessen the dependence on non-renewable resources to produce portland cement. The key objective of using alternative fuels is to continue to produce high-quality cement while decreasing the use of non-renewable fuels and minimizing the impact on the environment. Burn characteristics and thermodynamic parameters were evaluated with a laboratory burn simulator under conditions that mimic those in the preheater where the fuels are brought into a cement plant. A drop-tube furnace and visualization method were developed that show potential for evaluating time- and space-resolved temperature distributions for fuel solid particles and liquid droplets undergoing combustion in various combustion atmospheres. Downdraft gasification has been explored as a means to extract chemical energy from poultry litter while limiting the throughput of potentially deleterious components with regards to use in firing a cement kiln. Results have shown that the clinkering is temperature independent, at least within the controllable temperature range. Limestone also had only a slight effect on the fusion when used to coat the pellets. However, limestone addition did display some promise in regards to chlorine capture, as ash analyses showed chlorine concentrations of more than four times greater in the limestone infused ash as compared to raw poultry litter. A reliable and convenient sampling procedure was developed to estimate the combustion quality of broiler litter that is the best compromise between convenience and reliability by means of statistical analysis. Multi-day trial burns were conducted

  5. Process of producing a fuel, etc

    Energy Technology Data Exchange (ETDEWEB)

    1924-12-01

    This invention has for its object a process of producing fuels by separating a light oil from primary tar, characterized by a succession of operations comprising preliminary removal of phenols from the oils, removing sulfur completely by the application of suitable catalysts and an agent to fix the free sulfur as hydrogen sulfide; finally, washing to remove ethylenes, pyridines, and impurities from the treatment.

  6. Water Entrainment in Concrete

    DEFF Research Database (Denmark)

    Jensen, Ole Mejlhede; Hansen, Per Freiesleben

    This report gives a survey of different techniques for incorporation of designed, water-filled cavities in concrete: Water entrainment. Also an estimate of the optimum size of the water inclusions is given. Water entrainment can be used to avoid self-desiccation and self-desiccation shrinkage...... during hydration [1,26]. What is needed is some sort of container which retains the shape of the water when mixed into the concrete. The container may function based on several different physical or chemical principles. Cells and gels are examples of containers found in nature. A cell membrane provides...... a boundary to water, whereas a polymer network incorporates water in its intersticious space with its affinity due to interaction energy and polymer entropy. Such containers allow water to be stored as an entity. In relation to concrete the water encapsulation may be accomplished either before or after start...

  7. Process and device to produce fuel briquettes

    Energy Technology Data Exchange (ETDEWEB)

    Caroe, C J

    1980-10-23

    A two-stage process for the production of briquettes consisting essentially of cellulose (sawdust, peanut shells) is proposed. The fuel material (in case with additives) is molded by high pressure to pellets of the size of a few centimeters. The pellets are mixed with flammable binding agents like paraffin, wax, polyethylene etc. and molded at a lower pressure or extruded in a second step. A suited molding device is described. The wax content could be lowered with respect to known processes.

  8. Influences of in-fuel physical-chemical processes on serviceability of energy reactor fuel elements

    Energy Technology Data Exchange (ETDEWEB)

    Bibilashvili, Yu K; Nekrasova, G A; Sukhanov, G I

    1989-01-01

    In-fuel physico-chemical processes and their effect on stress corrosion cracking of fuel element zirconium cladding are considered in the review. The mechanism of fission product release from the fuel is studied and the negative role of primarily iodine on the cladding corrosion process is demonstrated. Directions for improving the fuel element claddings and fuel to increase the fuel element serviceability are specified.

  9. Influences of in-fuel physical-chemical processes on serviceability of energy reactor fuel elements

    International Nuclear Information System (INIS)

    Bibilashvili, Yu.K.; Nekrasova, G.A.; Sukhanov, G.I.

    1989-01-01

    In-fuel physico-chemical processes and their effect on stress corrosion cracking of fuel element zirconium cladding are considered in the review. The mechanism of fission product release from the fuel is studied and the negative role of primarily iodine on the cladding corrosion process is demonstrated. Directions for improving the fuel element claddings and fuel to increase the fuel element serviceability are specified

  10. Safeguardability of advanced spent fuel conditioning process

    Energy Technology Data Exchange (ETDEWEB)

    Li, T. K. (Tien K.); Lee, S. Y. (Sang Yoon); Burr, Tom; Russo, P. A. (Phyllis A.); Menlove, Howard O.; Kim, H. D.; Ko, W. I. (Won Il); Park, S. W.; Park, H. S.

    2004-01-01

    The Advanced Spent Fuel Conditioning Process (ACP) is an electro-metallurgical treatment technique to convert oxide-type spent nuclear fuel into a metallic form. The Korea Atomic Energy Research Institute (KAERI) has been developing this technology since 1977 for the purpose of spent fuel management and is planning to perform a lab-scale demonstration in 2006. By using of this technology, a significant reduction of the volume and heat load of spent fuel is expected, which would lighten the burden of final disposal in terms of disposal size, safety and economics. In the framework of collaboration agreement to develop the safeguards system for the ACP, a joint study on the safeguardability of the ACP technology has been performed by the Los Alamos National Laboratory (LANL) and the KAERI since 2002. In this study, the safeguardability of the ACP technology was examined for the pilot-scale facility. The process and material flows were conceptually designed, and the uncertainties in material accounting were estimated with international target values.

  11. Insight into the structure and functional application of the Sr0.95Ce0.05CoO3-δ cathode for solid oxide fuel cells.

    Science.gov (United States)

    Yang, Wei; Zhang, Huairuo; Sun, Chunwen; Liu, Lilu; Alonso, J A; Fernández-Díaz, M T; Chen, Liquan

    2015-04-06

    A new perovskite cathode, Sr0.95Ce0.05CoO3-δ, performs well for oxygen-reduction reactions in solid oxide fuel cells (SOFCs). We gain insight into the crystal structure of Sr1-xCexCoO3-δ (x = 0.05, 0.1) and temperature-dependent structural evolution of Sr0.95Ce0.05CoO3-δ by X-ray diffraction, neutron powder diffraction, and scanning transmission electron microscopy experiments. Sr0.9Ce0.1CoO3-δ shows a perfectly cubic structure (a = a0), with a large oxygen deficiency in a single oxygen site; however, Sr0.95Ce0.05CoO3-δ exhibits a tetragonal perovskite superstructure with a double c axis, defined in the P4/mmm space group, that contains two crystallographically different cobalt positions, with distinct oxygen environments. The structural evolution of Sr0.95Ce0.05CoO3-δ at high temperatures was further studied by in situ temperature-dependent NPD experiments. At 1100 K, the oxygen atoms in Sr0.95Ce0.05CoO3-δ show large and highly anisotropic displacement factors, suggesting a significant ionic mobility. The test cell with a La0.8Sr0.2Ga0.83Mg0.17O3-δ-electrolyte-supported (∼300 μm thickness) configuration yields peak power densities of 0.25 and 0.48 W cm(-2) at temperatures of 1023 and 1073 K, respectively, with pure H2 as the fuel and ambient air as the oxidant. The electrochemical impedance spectra evolution with time of the symmetric cathode fuel cell measured at 1073 K shows that the Sr0.95Ce0.05CoO3-δ cathode possesses superior ORR catalytic activity and long-term stability. Mixed ionic-electronic conduction properties of Sr0.95Ce0.05CoO3-δ account for its good performance as an oxygen-reduction catalyst.

  12. Detection of gas entrainment into liquid metals

    Energy Technology Data Exchange (ETDEWEB)

    Vogt, T., E-mail: t.vogt@hzdr.de [Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Institute of Fluid Dynamics, 01328 Dresden (Germany); Boden, S. [Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Institute of Fluid Dynamics, 01328 Dresden (Germany); Andruszkiewicz, A. [Faculty of Mechanical and Power Engineering, Wroclaw University of Technology (Poland); Eckert, K. [Technische Universität Dresden, Institute of Fluid Mechanics, 01062 Dresden (Germany); Eckert, S.; Gerbeth, G. [Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Institute of Fluid Dynamics, 01328 Dresden (Germany)

    2015-12-01

    Highlights: • We present liquid metal experiments dedicated to gas entrainment on the free surface. • Ultrasonic and X-ray attenuation techniques have been used to study the mechanisms of gas entrainment. • A comparison between bubbly flow in water and GaInSn showed substantial differences. • Our results emphasize the importance of liquid metal experiments which are able to provide a suitable data base for numerical code validation. - Abstract: Entrainment of cover gas into the liquid metal coolant is one of the principal safety issues in the design of innovative liquid metal-cooled fast reactors. We present generic experimental studies of this phenomenon in low-melting metals. Ultrasonic and X-ray diagnostic tools were considered for a visualization of gas entrainment at the free surface of the melt. Laboratory experiments were conducted using the eutectic alloy GaInSn, which is liquid at room temperature. Vortex-activated entrainment of air at the free surface of a rotating flow was revealed by ultrasonic techniques. X-ray radioscopy was used to visualize the behavior of argon bubbles inside a slit geometry. The measurements reveal distinct differences between water and GaInSn, especially with respect to the process of bubble formation and the coalescence and breakup of bubbles. Our results emphasize the importance of liquid metal experiments which are able to provide a suitable data base for numerical code validation.

  13. Luminescence characteristics of Pb2+ centres in undoped and Ce3+-doped Lu3Al5O12 single-crystalline films and Pb2+→Ce3+ energy transfer processes

    International Nuclear Information System (INIS)

    Babin, V.; Gorbenko, V.; Makhov, A.; Mares, J.A.; Nikl, M.; Zazubovich, S.; Zorenko, Yu.

    2007-01-01

    At 4.2-350 K, the steady-state and time-resolved emission and excitation spectra and luminescence decay kinetics were studied under excitation in the 2.5-15 eV energy range for the undoped and Ce 3+ -doped Lu 3 Al 5 O 12 (LuAG) single-crystalline films grown by liquid phase epitaxy method from the PbO-based flux. The spectral bands arising from the single Pb 2+ -based centres were identified. The processes of energy transfer from the host lattice to Pb 2+ and Ce 3+ ions and from Pb 2+ to Ce 3+ ions were investigated. Competition between Pb 2+ and Ce 3+ ions in the processes of energy transfer from the LuAG crystal lattice was evidenced especially in the exciton absorption region. Due to overlap of the 3.61 eV emission band of Pb 2+ centres with the 3.6 eV absorption band of Ce 3+ centres, an effective nonradiative energy transfer from Pb 2+ ions to Ce 3+ ions takes place, resulting in the appearance of slower component in the luminescence decay kinetics of Ce 3+ centres and decrease of the Ce 3+ -related luminescence intensity

  14. Modeling of a CeO2 thermochemistry reduction process for hydrogen production by solar concentrated energy

    Science.gov (United States)

    Valle-Hernández, Julio; Romero-Paredes, Hernando; Arancibia-Bulnes, Camilo A.; Villafan-Vidales, Heidi I.; Espinosa-Paredes, Gilberto

    2016-05-01

    In this paper the simulation of the thermal reduction for hydrogen production through the decomposition of cerium oxide is presented. The thermochemical cycle for hydrogen production consists of the endothermic reduction of CeO2 at high temperature, where concentrated solar energy is used as a source of heat; and of the subsequent steam hydrolysis of the resulting cerium oxide to produce hydrogen. For the thermochemical process, a solar reactor prototype is proposed; consisting of a cubic receptacle made of graphite fiber thermally insulated. Inside the reactor a pyramidal arrangement with nine tungsten pipes is housed. The pyramidal arrangement is made respect to the focal point where the reflected energy is concentrated. The solar energy is concentrated through the solar furnace of high radiative flux. The endothermic step is the reduction of the cerium oxide to lower-valence cerium oxide, at very high temperature. The exothermic step is the hydrolysis of the cerium oxide (III) to form H2 and the corresponding initial cerium oxide made at lower temperature inside the solar reactor. For the modeling, three sections of the pipe where the reaction occurs were considered; the carrier gas inlet, the porous medium and the reaction products outlet. The mathematical model describes the fluid mechanics; mass and energy transfer occurring therein inside the tungsten pipe. Thermochemical process model was simulated in CFD. The results show a temperature distribution in the solar reaction pipe and allow obtaining the fluid dynamics and the heat transfer within the pipe. This work is part of the project "Solar Fuels and Industrial Processes" from the Mexican Center for Innovation in Solar Energy (CEMIE-Sol).

  15. Process development and fabrication for sphere-pac fuel rods

    International Nuclear Information System (INIS)

    Welty, R.K.; Campbell, M.H.

    1981-06-01

    Uranium fuel rods containing sphere-pac fuel have been fabricated for in-reactor tests and demonstrations. A process for the development, qualification, and fabrication of acceptable sphere-pac fuel rods is described. Special equipment to control fuel contamination with moisture or air and the equipment layout needed for rod fabrication is described and tests for assuring the uniformity of the fuel column are discussed. Fuel retainers required for sphere-pac fuel column stability and instrumentation to measure fuel column smear density are described. Results of sphere-pac fuel rod fabrication campaigns are reviewed and recommended improvements for high throughput production are noted

  16. Modeling closed nuclear fuel cycles processes

    Energy Technology Data Exchange (ETDEWEB)

    Shmidt, O.V. [A.A. Bochvar All-Russian Scientific Research Institute for Inorganic Materials, Rogova, 5a street, Moscow, 123098 (Russian Federation); Makeeva, I.R. [Zababakhin All-Russian Scientific Research Institute of Technical Physics, Vasiliev street 13, Snezhinsk, Chelyabinsk region, 456770 (Russian Federation); Liventsov, S.N. [Tomsk Polytechnic University, Tomsk, Lenin Avenue, 30, 634050 (Russian Federation)

    2016-07-01

    Computer models of processes are necessary for determination of optimal operating conditions for closed nuclear fuel cycle (NFC) processes. Computer models can be quickly changed in accordance with new and fresh data from experimental research. 3 kinds of process simulation are necessary. First, the VIZART software package is a balance model development used for calculating the material flow in technological processes. VIZART involves taking into account of equipment capacity, transport lines and storage volumes. Secondly, it is necessary to simulate the physico-chemical processes that are involved in the closure of NFC. The third kind of simulation is the development of software that allows the optimization, diagnostics and control of the processes which implies real-time simulation of product flows on the whole plant or on separate lines of the plant. (A.C.)

  17. Industrial Maturity of FR Fuel Cycle Processes and Technologies

    International Nuclear Information System (INIS)

    Bruezière, Jérôme

    2013-01-01

    FR fuel cycle processes and technologies have already been proven industrially for Oxide Fuel, and to a lesser extent for metal fuel. In addition, both used oxide fuel reprocessing and fresh oxide fuel manufacturing benefit from similar industrial experience currently deployed for LWR. Alternative fuel type will have to generate very significant benefit in reactor ( safety, cost, … ) to justify corresponding development and industrialization costs

  18. Modification in fuel processing of Mitsubishi Nuclear Fuel's Tokai Works

    International Nuclear Information System (INIS)

    1976-01-01

    Results of the study by the Committee for Examination of Fuel Safety, reported to the AEC of Japan, are presented, concerning safety of the modifications of Tokai Works, Mitsubishi Nuclear Fuel Co., Ltd. Safety has been confirmed thereof. The modifications covered are the following: storage facility of nuclear fuel in increase, analytical facility in transfer, fuel assemblage equipment in addition, incineration facility of combustible solid wastes in installation, experimental facility of uranium recovery in installation, and warehouse in installation. (Mori, K.)

  19. Thermal Expansion Property of U-Zr Alloys and U-Zr-Ce Alloys as a Surrogate Metallic Fuel for SFR

    International Nuclear Information System (INIS)

    Kim, Sun Ki; Lee, Jong Tak; Oh, Seok Jin; Ko, Young Mo; Kim, Ki Hwan; Woo, Youn Myung; Lee, Chan Bock

    2010-01-01

    Metal fuels was selected for fueling many of the first reactors in the US, including the Experimental Breeder Reactor-I (EBR-I) and the Experimental Breeder Reactor-II (EBR-II) in Idaho, the FERMI-I reactor, and the Dounreay Fast Reactor (DFR) in the UK. Metallic U.Pu.Zr alloys were the reference fuel for the US Integral Fast Reactor (IFR) program. An extensive database on the performance of advanced metal fuels was generated as a result of the operation of these reactors and the IFR program. In this study, the U-Zr binary alloys and U-Zr-Ce ternary alloys as surrogate metallic fuel were fabricated in lower pressure Ar environment by gravity casting. The melt temperature was approximately 1,500 .deg. C. Thermal expansion of the fuel during normal operation is related with fuel performance in a reactor. Therefore, it is necessary to investigate the thermal expansion of the fuel in order to warrant a good prediction the fuel performance

  20. Effect of processing conditions and methods on residual stress in CeO2 buffer layers and YBCO superconducting films

    International Nuclear Information System (INIS)

    Xiong Jie; Qin Wenfeng; Cui Xumei; Tao Bowan; Tang Jinlong; Li Yanrong

    2006-01-01

    CeO 2 layers have been fabricated by pulsed laser deposition (PLD) technique on (1 1 0 2) sapphire substrate. Microstructure of CeO 2 layers is characterized by X-ray diffraction as functions of substrate temperature. The effects of the substrate temperature on the residual stress have been studied. The results show that residual stress in CeO 2 film decreased with increasing substrate temperature, not the same development tendency as that of thermal stress. This means that the thermal stress is only a fraction of the residual stress. Moreover, YBCO superconducting films were prepared by direct current (DC) sputtering and pulsed laser deposition (PLD) technique. The residual stress and thermal stress of both YBCO films were measured. PLD processing apparently generated higher intrinsic compressive stresses in comparison to DC sputtering

  1. Pyroelectrochemical process for reprocessing irradiated nuclear fuels

    International Nuclear Information System (INIS)

    Brambilla, G.; Sartorelli, A.

    1982-01-01

    A pyroelectrochemical process for reprocessing irradiated fast reactor mixed oxide or carbide fuels is described. The fuel is dissolved in a bath of molten alkali metal sulfates. The Pu(SO 4 ) 2 formed in the bath is thermally decomposed, leaving crystalline PuO 2 on the bottom of the reaction vessel. Electrodes are then introduced into the bath, and UO 2 is deposited on the cathode. Alternatively, both UO 2 and PuO 2 may be electrodeposited. The molten salts, after decontamination by precipitating the fission products dissolved in the bath by introducing basic agents such as oxides, carbonates, or hydroxides, may be recycled. Since it is not possible to remove cesium from the molten salt bath, periodic disposal and partial renewal with fresh salts is necessary. The melted salts that contain the fission products are conditioned for disposal by embedding them in a metallic matrix

  2. Plasma Technologies of Solid Fuels Processing

    International Nuclear Information System (INIS)

    Karpenko, E.I.; Messerle, V.E.; Ustimenko, A.

    2003-01-01

    Use of fuel processing plasma technologies improves ecological and economical indexes of low-grade coal utilization at thermal power plants. This paper presents experimental plasma plant 70 k W of power and 11 kg per hour of coal productivity. On the base of material and heat balances integral indexes of the process of plasma gasification of Podmoskovny brown coal 48% of ash content were found. Synthesis gas with concentration 85.2% was got. Hydrogen concentration in the synthesis gas was higher than carbon monoxide one. Ratio H 2 :CO in synthesis gas was 1.4-1.5. It was shown that steam consumption and temperature of the process increase causes H 2 concentration and coal gasification degree increase. Fulfilled experiments and comparison of their result with theoretical investigations allowed creating pilot experimental plant for plasma processing of low-grade coals. The power of the pilot plant is 1000 k W and coal productivity is 300 kg/h. (author)

  3. Chemical process safety at fuel cycle facilities

    International Nuclear Information System (INIS)

    Ayres, D.A.

    1997-08-01

    This NUREG provides broad guidance on chemical safety issues relevant to fuel cycle facilities. It describes an approach acceptable to the NRC staff, with examples that are not exhaustive, for addressing chemical process safety in the safe storage, handling, and processing of licensed nuclear material. It expounds to license holders and applicants a general philosophy of the role of chemical process safety with respect to NRC-licensed materials; sets forth the basic information needed to properly evaluate chemical process safety; and describes plausible methods of identifying and evaluating chemical hazards and assessing the adequacy of the chemical safety of the proposed equipment and facilities. Examples of equipment and methods commonly used to prevent and/or mitigate the consequences of chemical incidents are discussed in this document

  4. WWER-1000 nuclear fuel manufacturing process at PJSC MSZ

    International Nuclear Information System (INIS)

    Morylev, A.; Bagdatyeva, E.; Aksenov, P.

    2015-01-01

    In this report a brief description of WWER-1000 fuel manufacturing process steps at PJSC MSZ as: uranium dioxide powder fabrication; fuel pellet manufacture fuel rod manufacture working assembly and fuel assembly manufacture is given. The implemented innovations are also presented

  5. Complex plasmochemical processing of solid fuel

    Directory of Open Access Journals (Sweden)

    Vladimir Messerle

    2012-12-01

    Full Text Available Technology of complex plasmaochemical processing of solid fuel by Ecibastuz bituminous and Turgay brown coals is presented. Thermodynamic and experimental study of the technology was fulfilled. Use of this technology allows producing of synthesis gas from organic mass of coal and valuable components (technical silicon, ferrosilicon, aluminum and silicon carbide and microelements of rare metals: uranium, molybdenum, vanadium etc. from mineral mass of coal. Produced a high-calorific synthesis gas can be used for methanol synthesis, as high-grade reducing gas instead of coke, as well as energy gas in thermal power plants.

  6. Dissolution process for advanced-PWR-type fuels

    International Nuclear Information System (INIS)

    Black, D.E.; Decker, L.A.; Pearson, L.G.

    1979-01-01

    The new Fluorinel Dissolution Process and Fuel Storage (FAST) Facility at ICPP will provide underwater storage of spent PWR fuel and a new head-end process for fuel dissolution. The dissolution will be two-stage, using HF and HNO 3 , with an intermittent H 2 SO 4 dissolution for removing stainless steel components. Equipment operation is described

  7. Adsorption process of fluoride from drinking water with magnetic core-shell Ce-Ti@Fe3O4 and Ce-Ti oxide nanoparticles.

    Science.gov (United States)

    Abo Markeb, Ahmad; Alonso, Amanda; Sánchez, Antoni; Font, Xavier

    2017-11-15

    Synthesized magnetic core-shell Ce-Ti@Fe 3 O 4 nanoparticles were tested, as an adsorbent, for fluoride removal and the adsorption studies were optimized. Adsorption capacity was compared with the synthesized Ce-Ti oxide nanoparticles. The adsorption equilibrium for the Ce-Ti@Fe 3 O 4 adsorbent was found to occur in cycles of adsorption-desorption. Although the nanoparticles suffer slight structure modifications after their reusability, they keep their adsorption capacity. Likewise, the efficiency of the Ce-Ti@Fe 3 O 4 was demonstrated when applied to real water to obtain a residual concentration of F - below the maximum contaminated level, 1.5mg/L (WHO, 2006). Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Effects of Fuel Quantity on Soot Formation Process for Biomass-Based Renewable Diesel Fuel Combustion

    KAUST Repository

    Jing, Wei; Wu, Zengyang; Roberts, William L.; Fang, Tiegang

    2016-01-01

    Soot formation process was investigated for biomass-based renewable diesel fuel, such as biomass to liquid (BTL), and conventional diesel combustion under varied fuel quantities injected into a constant volume combustion chamber. Soot measurement

  9. Energy efficiency enhancement of ethanol electrooxidation on Pd-CeO(2)/C in passive and active polymer electrolyte-membrane fuel cells.

    Science.gov (United States)

    Bambagioni, Valentina; Bianchini, Claudio; Chen, Yanxin; Filippi, Jonathan; Fornasiero, Paolo; Innocenti, Massimo; Lavacchi, Alessandro; Marchionni, Andrea; Oberhauser, Werner; Vizza, Francesco

    2012-07-01

    Pd nanoparticles have been generated by performing an electroless procedure on a mixed ceria (CeO(2))/carbon black (Vulcan XC-72) support. The resulting material, Pd-CeO(2)/C, has been characterized by means of transmission electron microscopy (TEM), inductively coupled plasma atomic emission spectroscopy (ICP-AES), and X-ray diffraction (XRD) techniques. Electrodes coated with Pd-CeO(2)/C have been scrutinized for the oxidation of ethanol in alkaline media in half cells as well as in passive and active direct ethanol fuel cells (DEFCs). Membrane electrode assemblies have been fabricated using Pd-CeO(2)/C anodes, proprietary Fe-Co cathodes, and Tokuyama anion-exchange membranes. The monoplanar passive and active DEFCs have been fed with aqueous solutions of 10 wt% ethanol and 2 M KOH, supplying power densities as high as 66 mW cm(-2) at 25 °C and 140 mW cm(-2) at 80 °C. A comparison with a standard anode electrocatalyst containing Pd nanoparticles (Pd/C) has shown that, at even metal loading and experimental conditions, the energy released by the cells with the Pd-CeO(2)/C electrocatalyst is twice as much as that supplied by the cells with the Pd/C electrocatalyst. A cyclic voltammetry study has shown that the co-support ceria contributes to the remarkable decrease of the onset oxidation potential of ethanol. It is proposed that ceria promotes the formation at low potentials of species adsorbed on Pd, Pd(I)-OH(ads), that are responsible for ethanol oxidation. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Property-process relationships in nuclear fuel fabrication

    International Nuclear Information System (INIS)

    Tikare, V.

    2015-01-01

    Nuclear fuels are fabricated using many different techniques as they come in a large variety of shapes and compositions. The design and composition of nuclear fuels are predominantly dictated by the engineering requirements necessary for their function in reactors of various designs. Other engineering properties requirements originate from safety and security concerns, and the easy of handling, storing, transporting and disposing of the radioactive materials. In this chapter, the more common of these fuels will be briefly reviewed and the methods used to fabricate them will be presented. The fuels considered in this paper are oxide fuels used in LWRs and FRs, metal fuels in FRs and particulate fuels used in HTGRs. Fabrication of alternative fuel forms and use of standard fuels in alternative reactors will be discussed briefly. The primary motivation to advance fuel fabrication is to improve performance, reduce cost, reduce waste or enhance safety and security of the fuels. To achieve optimal performance, developing models to advance fuel fabrication has to be done in concert with developing fuel performance models. The specific properties and microstructures necessary for improved fuel performance must be identified using fuel performance models, while fuel fabrication models that can determine processing variables to give the desired microstructure and materials properties must be developed. (author)

  11. Speech Entrainment Compensates for Broca's Area Damage

    Science.gov (United States)

    Fridriksson, Julius; Basilakos, Alexandra; Hickok, Gregory; Bonilha, Leonardo; Rorden, Chris

    2015-01-01

    Speech entrainment (SE), the online mimicking of an audiovisual speech model, has been shown to increase speech fluency in patients with Broca's aphasia. However, not all individuals with aphasia benefit from SE. The purpose of this study was to identify patterns of cortical damage that predict a positive response SE's fluency-inducing effects. Forty-four chronic patients with left hemisphere stroke (15 female) were included in this study. Participants completed two tasks: 1) spontaneous speech production, and 2) audiovisual SE. Number of different words per minute was calculated as a speech output measure for each task, with the difference between SE and spontaneous speech conditions yielding a measure of fluency improvement. Voxel-wise lesion-symptom mapping (VLSM) was used to relate the number of different words per minute for spontaneous speech, SE, and SE-related improvement to patterns of brain damage in order to predict lesion locations associated with the fluency-inducing response to speech entrainment. Individuals with Broca's aphasia demonstrated a significant increase in different words per minute during speech entrainment versus spontaneous speech. A similar pattern of improvement was not seen in patients with other types of aphasia. VLSM analysis revealed damage to the inferior frontal gyrus predicted this response. Results suggest that SE exerts its fluency-inducing effects by providing a surrogate target for speech production via internal monitoring processes. Clinically, these results add further support for the use of speech entrainment to improve speech production and may help select patients for speech entrainment treatment. PMID:25989443

  12. Development of Advanced Spent Fuel Management Process

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Chung Seok; Choi, I. K.; Kwon, S. G. (and others)

    2007-06-15

    As a part of research efforts to develop an advanced spent fuel management process, this project focused on the electrochemical reduction technology which can replace the original Li reduction technology of ANL, and we have successfully built a 20 kgHM/batch scale demonstration system. The performance tests of the system in the ACPF hot cell showed more than a 99% reduction yield of SIMFUEL, a current density of 100 mA/cm{sup 2} and a current efficiency of 80%. For an optimization of the process, the prevention of a voltage drop in an integrated cathode, a minimization of the anodic effect and an improvement of the hot cell operability by a modulation and simplization of the unit apparatuses were achieved. Basic research using a bench-scale system was also carried out by focusing on a measurement of the electrochemical reduction rate of the surrogates, an elucidation of the reaction mechanism, collecting data on the partition coefficients of the major nuclides, quantitative measurement of mass transfer rates and diffusion coefficients of oxygen and metal ions in molten salts. When compared to the PYROX process of INL, the electrochemical reduction system developed in this project has comparative advantages in its application of a flexible reaction mechanism, relatively short reaction times and increased process yields.

  13. Development of Advanced Spent Fuel Management Process

    International Nuclear Information System (INIS)

    Seo, Chung Seok; Choi, I. K.; Kwon, S. G.

    2007-06-01

    As a part of research efforts to develop an advanced spent fuel management process, this project focused on the electrochemical reduction technology which can replace the original Li reduction technology of ANL, and we have successfully built a 20 kgHM/batch scale demonstration system. The performance tests of the system in the ACPF hot cell showed more than a 99% reduction yield of SIMFUEL, a current density of 100 mA/cm 2 and a current efficiency of 80%. For an optimization of the process, the prevention of a voltage drop in an integrated cathode, a minimization of the anodic effect and an improvement of the hot cell operability by a modulation and simplization of the unit apparatuses were achieved. Basic research using a bench-scale system was also carried out by focusing on a measurement of the electrochemical reduction rate of the surrogates, an elucidation of the reaction mechanism, collecting data on the partition coefficients of the major nuclides, quantitative measurement of mass transfer rates and diffusion coefficients of oxygen and metal ions in molten salts. When compared to the PYROX process of INL, the electrochemical reduction system developed in this project has comparative advantages in its application of a flexible reaction mechanism, relatively short reaction times and increased process yields

  14. Pt-Ru/CeO2/carbon nanotube nanocomposites: an efficient electrocatalyst for direct methanol fuel cells.

    Science.gov (United States)

    Sun, Zhenyu; Wang, Xiang; Liu, Zhimin; Zhang, Hongye; Yu, Ping; Mao, Lanqun

    2010-07-20

    Pt-Ru/CeO(2)/multiwalled carbon nanotube (MWNT) electrocatalysts were prepared using a rapid sonication-facilitated deposition method and were characterized by X-ray diffraction (XRD), X-ray photoemission spectroscopy (XPS), transmission electron microscopy (TEM), energy-dispersive spectroscopy (EDS), and voltammetry. Morphological characterization by TEM revealed that CeO(2) nanoparticles (NPs) were in intimate contact with Pt-Ru NPs, and both were highly dispersed on the exteriors of nanotubes with a small size and a very narrow size distribution. Compared with the Pt-Ru/MWNT and Pt/MWNT electrocatalysts, the as-prepared Pt-Ru/CeO(2)/MWNT exhibited a significantly improved electrochemically active surface area (ECSA) and a remarkably enhanced activity toward methanol oxidation. The effects of the Pt-Ru loading and the Pt-to-Ru molar ratio on the electrocatalytic activity of Pt-Ru/CeO(2)/MWNT for methanol oxidation were investigated. We found that a maximum activity toward methanol oxidation reached at the 10 wt % of Pt-Ru loading and 1:1 of Pt-to-Ru ratio. Moreover, the role of CeO(2) in the catalysts for the enhancement of methanol oxidation was discussed in terms of both bifunctional mechanism and electronic effects.

  15. Cost reductions of fuel cells for transport applications: fuel processing options

    Energy Technology Data Exchange (ETDEWEB)

    Teagan, W P; Bentley, J; Barnett, B [Arthur D. Little, Inc., Cambridge, MA (United States)

    1998-03-15

    The highly favorable efficiency/environmental characteristics of fuel cell technologies have now been verified by virtue of recent and ongoing field experience. The key issue regarding the timing and extent of fuel cell commercialization is the ability to reduce costs to acceptable levels in both stationary and transport applications. It is increasingly recognized that the fuel processing subsystem can have a major impact on overall system costs, particularly as ongoing R and D efforts result in reduction of the basic cost structure of stacks which currently dominate system costs. The fuel processing subsystem for polymer electrolyte membrane fuel cell (PEMFC) technology, which is the focus of transport applications, includes the reformer, shift reactors, and means for CO reduction. In addition to low cost, transport applications require a fuel processor that is compact and can start rapidly. This paper describes the impact of factors such as fuel choice operating temperature, material selection, catalyst requirements, and controls on the cost of fuel processing systems. There are fuel processor technology paths which manufacturing cost analyses indicate are consistent with fuel processor subsystem costs of under $150/kW in stationary applications and $30/kW in transport applications. As such, the costs of mature fuel processing subsystem technologies should be consistent with their use in commercially viable fuel cell systems in both application categories. (orig.)

  16. Role of ion chromatograph in nuclear fuel fabrication process at Nuclear Fuel Complex

    International Nuclear Information System (INIS)

    Balaji Rao, Y.; Prasada Rao, G.; Prahlad, B.; Saibaba, N.

    2012-01-01

    The present paper discusses the different applications of ion chromatography followed in nuclear fuel fabrication process at Nuclear Fuel Complex. Some more applications of IC for characterization of nuclear materials and which are at different stages of method development at Control Laboratory, Nuclear Fuel Complex are also highlighted

  17. Photodynamic processes in LiCaAlF6:Ce3+ UV active medium

    International Nuclear Information System (INIS)

    Galiev, A I; Semashko, V V; Akhtyamov, O R; Shnaidman, S A; Marisov, M A; Shavelev, A A

    2014-01-01

    The objectives of this paper are experimental studies of pump-induced effects in LiCaAlF 6 : Ce 3+ single crystals and computer model elaboration and appropriated software package engineering. The elaborated experimental technique and software allow either to calculate the nonlinear absorption/gain characteristics of the active medium on the basis of known parameters, or to find its previously unknown parameters from pump-probe experimental dependences

  18. DOE Coal Gasification Multi-Test Facility: fossil fuel processing technical/professional services

    Energy Technology Data Exchange (ETDEWEB)

    Hefferan, J.K.; Lee, G.Y.; Boesch, L.P.; James, R.B.; Rode, R.R.; Walters, A.B.

    1979-07-13

    A conceptual design, including process descriptions, heat and material balances, process flow diagrams, utility requirements, schedule, capital and operating cost estimate, and alternative design considerations, is presented for the DOE Coal Gasification Multi-Test Facility (GMTF). The GMTF, an engineering scale facility, is to provide a complete plant into which different types of gasifiers and conversion/synthesis equipment can be readily integrated for testing in an operational environment at relatively low cost. The design allows for operation of several gasifiers simultaneously at a total coal throughput of 2500 tons/day; individual gasifiers operate at up to 1200 tons/day and 600 psig using air or oxygen. Ten different test gasifiers can be in place at the facility, but only three can be operated at one time. The GMTF can produce a spectrum of saleable products, including low Btu, synthesis and pipeline gases, hydrogen (for fuel cells or hydrogasification), methanol, gasoline, diesel and fuel oils, organic chemicals, and electrical power (potentially). In 1979 dollars, the base facility requires a $288 million capital investment for common-use units, $193 million for four gasification units and four synthesis units, and $305 million for six years of operation. Critical reviews of detailed vendor designs are appended for a methanol synthesis unit, three entrained flow gasifiers, a fluidized bed gasifier, and a hydrogasifier/slag-bath gasifier.

  19. Method of processing spent fuel cladding tubes

    International Nuclear Information System (INIS)

    Nakatsuka, Masafumi; Ouchi, Atsuhiro; Imahashi, Hiromichi.

    1986-01-01

    Purpose: To decrease the residual activity of spent fuel cladding tubes in a short period of time and enable safety storage with simple storage equipments. Constitution: Spent fuel cladding tubes made of zirconium alloys discharged from a nuclear fuel reprocessing step are exposed to a grain boundary embrittling atmosphere to cause grain boundary destruction. This causes grain boundary fractures to the zirconium crystal grains as the matrix of nuclear fuels and then precipitation products precipitated to the grain boundary fractures are removed. The zirconium constituting the nuclear fuel cladding tube and other ingredient elements contained in the precipitation products are separated in this removing step and they are separately stored respectively. As a result, zirconium constituting most part of the composition of the spent nuclear fuel cladding tubes can be stored safely at a low activity level. (Takahashi, M.)

  20. Nuclear fuel re-processing plant

    International Nuclear Information System (INIS)

    Sasaki, Yuko; Honda, Takashi; Shoji, Saburo; Kobayashi, Shiro; Furuya, Yasumasa

    1989-01-01

    In a nuclear fuel re-processing plant, high Si series stainless steels not always have sufficient corrosion resistance in a solution containing only nitric acid at medium or high concentration. Further, a method of blowing NOx gases may possibly promote the corrosion of equipment constituent materials remarkably. In view of the above, the corrosion promoting effect of nuclear fission products is suppressed without depositing corrosive metal ions as metals in the nitric acid solution. That is, a reducing atmosphere is formed by generating NOx by electrolytic reduction thereby preventing increase in the surface potential of stainless steels. Further, an anode is disposed in the nitric acid solution containing oxidative metal ions to establish an electrical conduction and separate them by way of partition membranes and a constant potential or constant current is applied while maintaining an ionic state so as not to deposit metals. Thus, equipments of re-processing facility can be protected from corrosion with no particular treatment for wastes as radioactive materials. (K.M.)

  1. The investigation of HTGR fuel regeneration process

    Energy Technology Data Exchange (ETDEWEB)

    Lazarev, L N; Bertina, L E; Popik, V P; Isakov, V P; Alkhimov, N B; Pokhitonov, Yu A

    1985-07-01

    The aim of this report is the investigation of HTGR fuel regeneration. The operation in the technologic scheme of uranium extraction from fuel depleted elements is separation of fuel from graphite. Available methods of graphite matrix destruction are: mechanical destruction, chemical destruction, and burning. Mechanical destruction is done in combination with leaching or chlorination. Methods of chemical destruction of graphite matrix are not sufficiently studied. Most of the investigations nowadays sre devoted to removal of graphite by burning.

  2. Electrochemical processing of spent nuclear fuel

    Energy Technology Data Exchange (ETDEWEB)

    Williamson, M. A.; Willit, J. L.; Barnes, L. A.; Figueroa, J.; Limmer, S. L.; Blaskovitz, R. [Argonne National Laboratory, Argonne (United States)

    2008-08-15

    Our work in developing the fuel cycles and electrochemical technologies needed for the treatment of spent light water reactor and spent fast reactor fuel is progressing well. Baseline flowsheets along with a theoretical material balance have been developed for treatment of each type of fuel. A discussion about the flowsheets provides the opportunity to present the status of our technology development activities and future research and development directions.

  3. Electrochemical processing of spent nuclear fuel

    International Nuclear Information System (INIS)

    Williamson, M. A.; Willit, J. L.; Barnes, L. A.; Figueroa, J.; Limmer, S. L.; Blaskovitz, R.

    2008-01-01

    Our work in developing the fuel cycles and electrochemical technologies needed for the treatment of spent light water reactor and spent fast reactor fuel is progressing well. Baseline flowsheets along with a theoretical material balance have been developed for treatment of each type of fuel. A discussion about the flowsheets provides the opportunity to present the status of our technology development activities and future research and development directions

  4. The investigation of HTGR fuel regeneration process

    International Nuclear Information System (INIS)

    Lazarev, L.N.; Bertina, L.E.; Popik, V.P.; Isakov, V.P.; Alkhimov, N.B.; Pokhitonov, Yu.A.

    1985-01-01

    The aim of this report is the investigation of HTGR fuel regeneration. The operation in the technologic scheme of uranium extraction from fuel depleted elements is separation of fuel from graphite. Available methods of graphite matrix destruction are: mechanical destruction, chemical destruction, and burning. Mechanical destruction is done in combination with leaching or chlorination. Methods of chemical destruction of graphite matrix are not sufficiently studied. Most of the investigations nowadays sre devoted to removal of graphite by burning

  5. Fuel Cell Stations Automate Processes, Catalyst Testing

    Science.gov (United States)

    2010-01-01

    Glenn Research Center looks for ways to improve fuel cells, which are an important source of power for space missions, as well as the equipment used to test fuel cells. With Small Business Innovation Research (SBIR) awards from Glenn, Lynntech Inc., of College Station, Texas, addressed a major limitation of fuel cell testing equipment. Five years later, the company obtained a patent and provided the equipment to the commercial world. Now offered through TesSol Inc., of Battle Ground, Washington, the technology is used for fuel cell work, catalyst testing, sensor testing, gas blending, and other applications. It can be found at universities, national laboratories, and businesses around the world.

  6. Sediment particle entrainment in an obstructed annular

    Energy Technology Data Exchange (ETDEWEB)

    Loureiro, Bruno Venturini; Siqueira, Renato do Nascimento [Faculdade do Centro Leste (UCL), Serra, ES (Brazil). Lab. de Fenomenos de Transporte], e-mail: brunovl@ucl.br, e-mail: renatons@ucl.br

    2006-07-01

    Flow in an annular region with internal cylinder rotation is a classic problem in fluid mechanics and has been widely studied. Besides its importance as a fundamental problem, flow in annular regions has several practical applications. This project was motivated by an application of this kind of flow to the drilling of oil and gas wells. In this work, an erosion apparatus was constructed in order to study the effect of the internal cylinder rotation on particle entrainment in an obstructed annular space and bed package as well. The study also analyzed the influence of height of the particles bed on the process performance. The experiment was designed so that the internal cylinder rotation could be measured by an encoder. The fluid temperature was measured by a thermocouple and the experiments were carried out at the temperature of 25 deg C. The study revealed that the particle entrainment for the height of the bed that is close to the center of the cylinders is negligible and the internal cylinder rotation provokes the movement and packing of the bed. For lower height of the bed, with same dimension of the annular gap, the particle entrainment process was satisfactory and the bed compaction was smaller than in the previous case, leading to a more efficient cleaning process in the annular space. (author)

  7. Experimental study of gas entrainment from surface swirl

    Energy Technology Data Exchange (ETDEWEB)

    Moudjed, B., E-mail: brahim.moudjed@cea.fr; Excoffon, J.; Riva, R.; Rossi, L., E-mail: lionel.rossi@cea.fr

    2016-12-15

    Gas entrainment from surface swirls is characterized using water experiments. A free surface shear flow is generated in an open channel flow. A suction nozzle is set at the bottom of the test section to induce a downward flow and provoke gas entrainment. An important originality of these experiments is the possibility to change the inlet condition so as to generate different turbulent shear flows. This is done by adding obstacles of different sizes and shapes at the end of a flat plate separating the inlet flow from a “stagnant” water area. Velocity fields and profiles, measured with the PIV technique, are provided both to describe the inlet conditions corresponding to various geometries and flow rates, and to characterize the temporal average shear flow generated within the centre part of the channel. Gas entrainment mappings are established from direct observations of the different flow configurations. These new results show that the threshold for the suction velocities required to entrain gas are similar for the configurations with small obstacles and the flat plate configuration triggering a standard shear flow. Increasing the size of the obstacles promotes gas entrainment and reduces the threshold values of the suction velocity to trigger gas entrainment. Shadowgraphy with image processing is used to present new results characterizing the geometrical properties of surface swirls and the quantity of gas entrained. Inlet configurations with obstacles generate larger surface swirls which move upstream from the suction nozzle centre whereas they are situated downstream with the flat plate configuration. Moreover, dimensionless power laws are found to be good approximations for the surface swirl width and the quantity of gas entrained. In addition to provide new insights about gas entrainment in analytical configurations relevant to Sodium cooled fast nuclear reactor, these results should provide different test cases for the validation of MCFD codes.

  8. Mixed U/Pu oxide fuel fabrication facility co-processed feed, pelletized fuel

    International Nuclear Information System (INIS)

    1978-09-01

    Two conceptual MOX fuel fabrication facilities are discussed in this study. The first facility in the main body of the report is for the fabrication of LWR uranium dioxide - plutonium dioxide (MOX) fuel using co-processed feed. The second facility in the addendum is for the fabrication of co-processed MOX fuel spiked with 60 Co. Both facilities produce pellet fuel. The spiked facility uses the same basic fabrication process as the conventional MOX plant but the fuel feed incorporates a high energy gamma emitter as a safeguard measure against diversion; additional shielding is added to protect personnel from radiation exposure, all operations are automated and remote, and normal maintenance is performed remotely. The report describes the fuel fabrication process and plant layout including scrap and waste processing; and maintenance, ventilation and safety measures

  9. Purification of hydrogen from carbon monoxide for fuel cell application over modified mesoporous CuO-CeO2 catalysts

    KAUST Repository

    Li, Jing

    2011-08-01

    Selective oxidation of CO in H2-rich streams was carried out over a series of CuO-CeO2 catalysts doped by different transition metals (Mn, Fe, Ni, Ti, Co and Cr). The effect of the dopants on the structure and catalytic properties of CuO-CeO2 catalysts was investigated by N2 adsorption/desorption, X-ray diffraction (XRD), H2 temperature-programmed reduction (H2-TPR), X-ray photoelectron spectroscopy (XPS), Raman spectra and in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) techniques. The results show that the addition of Mn and Fe plays a beneficial role in extending the low-temperature catalytic activity of CuO-CeO2 catalysts, whereas the introduction of Cr and Co leads to a negative effect on the catalytic activity and resistance against CO2 and H2O. The superior catalytic performance of CuO-CeO2 catalysts with Mn and Fe doping originates from the enhanced interaction between copper and ceria, owing to the formation of more Cu+ and oxygen vacancies in the solid solution framework. While the poor catalytic activity of the Co doped counterpart is mainly ascribed to the substitution of introduced cobalt ions for copper ions in ceria lattice, resulting in the segregation of copper ions from the ceria lattice and the consequent aggregation of copper species on the ceria surface. The doping of Cr into CuO-CeO2 structure remarkably weakens the interaction between copper and ceria, which decreases the reducibility of copper species and inhibits the formation of Cu+. It accounts for the lowest catalytic activity. © 2011 Elsevier B.V.

  10. Purification of hydrogen from carbon monoxide for fuel cell application over modified mesoporous CuO-CeO2 catalysts

    KAUST Repository

    Li, Jing; Han, Yuxi; Zhu, Yihan; Zhou, Renxian

    2011-01-01

    Selective oxidation of CO in H2-rich streams was carried out over a series of CuO-CeO2 catalysts doped by different transition metals (Mn, Fe, Ni, Ti, Co and Cr). The effect of the dopants on the structure and catalytic properties of CuO-CeO2 catalysts was investigated by N2 adsorption/desorption, X-ray diffraction (XRD), H2 temperature-programmed reduction (H2-TPR), X-ray photoelectron spectroscopy (XPS), Raman spectra and in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) techniques. The results show that the addition of Mn and Fe plays a beneficial role in extending the low-temperature catalytic activity of CuO-CeO2 catalysts, whereas the introduction of Cr and Co leads to a negative effect on the catalytic activity and resistance against CO2 and H2O. The superior catalytic performance of CuO-CeO2 catalysts with Mn and Fe doping originates from the enhanced interaction between copper and ceria, owing to the formation of more Cu+ and oxygen vacancies in the solid solution framework. While the poor catalytic activity of the Co doped counterpart is mainly ascribed to the substitution of introduced cobalt ions for copper ions in ceria lattice, resulting in the segregation of copper ions from the ceria lattice and the consequent aggregation of copper species on the ceria surface. The doping of Cr into CuO-CeO2 structure remarkably weakens the interaction between copper and ceria, which decreases the reducibility of copper species and inhibits the formation of Cu+. It accounts for the lowest catalytic activity. © 2011 Elsevier B.V.

  11. Modified ADS molten salt processes for back-end fuel cycle of PWR spent fuel

    International Nuclear Information System (INIS)

    Choi, In-Kyu; Yeon, Jei-Won; Kim, Won-Ho

    2002-01-01

    The back-end fuel cycle concept for PWR spent fuel is explained. This concept is adequate for Korea, which has operated both PWR and CANDU reactors. Molten salt processes for accelerator driven system (ADS) were modified both for the transmutation of long-lived radioisotopes and for the utilisation of the remained fissile uranium in PWR spent fuels. Prior to applying molten salt processes to PWR fuel, hydrofluorination and fluorination processes are applied to obtain uranium hexafluoride from the spent fuel pellet. It is converted to uranium dioxide and fabricated into CANDU fuel. From the remained fluoride compounds, transuranium elements can be separated by the molten salt technology such as electrowinning and reductive extraction processes for transmutation purpose without weakening the proliferation resistance of molten salt technology. The proposed fuel cycle concept using fluorination processes is thought to be adequate for our nuclear program and can replace DUPIC (Direct Use of spent PWR fuel in CANDU reactor) fuel cycle. Each process for the proposed fuel cycle concept was evaluated in detail

  12. Measurement of air entrainment in plasma jets

    International Nuclear Information System (INIS)

    Fincke, J.R.; Rodriquez, R.; Pentecost, C.G.

    1990-01-01

    The concentration and temperature of air entrained into argon and helium plasma jets has been measured using coherent anti-Stokes Raman spectroscopy (CARS). The argon plasma flow field is characterized by a short region of well behaved laminar flow near the nozzle exit followed by an abrupt transition to turbulence. Once the transition of turbulence occurs, air is rapidly mixed into the jet core. The location of the transition region is determined by the rapid cooling of the jet and the resulting increase in Reynolds number. In contrast, the helium plasma flow field never exceeds a Reynolds number of 200 and remains laminar. The entrainment process in this case is controlled by molecular diffusion rather than turbulent mixing. 9 refs., 5 figs., 1 tab

  13. Materials and processes for solar fuel production

    CERN Document Server

    Viswanathan, Balasubramanian; Lee, Jae Sung

    2014-01-01

    This book features different approaches to non-biochemical pathways for solar fuel production. This one-of-a-kind book addresses photovoltaics, photocatalytic water splitting for clean hydrogen production and CO2 conversion to hydrocarbon fuel through in-depth comprehensive contributions from a select blend of established and experienced authors from across the world. The commercial application of solar based systems, with particular emphasis on non-PV based devices have been discussed. This book intends to serve as a primary resource for a multidisciplinary audience including chemists, engineers and scientists providing a one-stop location for all aspects related to solar fuel production. The material is divided into three sections: Solar assisted water splitting to produce hydrogen; Solar assisted CO2 utilization to produce green fuels and Solar assisted electricity generation. The content strikes a balance between theory, material synthesis and application with the central theme being solar fuels.

  14. Handbook on process and chemistry on nuclear fuel reprocessing

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Atsuyuki [Tokyo Univ., Tokyo (Japan); Asakura, Toshihide; Adachi, Takeo [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; and others

    2001-12-01

    'Wet-type' nuclear fuel reprocessing technology, based on PUREX technology, has wide applicability as the principal reprocessing technology of the first generation, and relating technologies, waste management for example, are highly developed, too. It is quite important to establish a database summarizing fundamental information about the process and the chemistry of 'wet-type' reprocessing, because it contributes to establish and develop fuel reprocessing process and nuclear fuel cycle treating high burn-up UO{sub 2} fuel and spent MOX fuel, and to utilize 'wet-type' reprocessing technology much widely. This handbook summarizes the fundamental data on process and chemistry, which was collected and examined by 'Editing Committee of Handbook on Process and Chemistry of Nuclear Fuel Reprocessing', from FY 1993 until FY 2000. (author)

  15. Handbook on process and chemistry on nuclear fuel reprocessing

    International Nuclear Information System (INIS)

    Suzuki, Atsuyuki; Asakura, Toshihide; Adachi, Takeo

    2001-12-01

    'Wet-type' nuclear fuel reprocessing technology, based on PUREX technology, has wide applicability as the principal reprocessing technology of the first generation, and relating technologies, waste management for example, are highly developed, too. It is quite important to establish a database summarizing fundamental information about the process and the chemistry of 'wet-type' reprocessing, because it contributes to establish and develop fuel reprocessing process and nuclear fuel cycle treating high burn-up UO 2 fuel and spent MOX fuel, and to utilize 'wet-type' reprocessing technology much widely. This handbook summarizes the fundamental data on process and chemistry, which was collected and examined by 'Editing Committee of Handbook on Process and Chemistry of Nuclear Fuel Reprocessing', from FY 1993 until FY 2000. (author)

  16. Handbook on process and chemistry on nuclear fuel reprocessing

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Atsuyuki (ed.) [Tokyo Univ., Tokyo (Japan); Asakura, Toshihide; Adachi, Takeo (eds.) [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment] [and others

    2001-12-01

    'Wet-type' nuclear fuel reprocessing technology, based on PUREX technology, has wide applicability as the principal reprocessing technology of the first generation, and relating technologies, waste management for example, are highly developed, too. It is quite important to establish a database summarizing fundamental information about the process and the chemistry of 'wet-type' reprocessing, because it contributes to establish and develop fuel reprocessing process and nuclear fuel cycle treating high burn-up UO{sub 2} fuel and spent MOX fuel, and to utilize 'wet-type' reprocessing technology much widely. This handbook summarizes the fundamental data on process and chemistry, which was collected and examined by 'Editing Committee of Handbook on Process and Chemistry of Nuclear Fuel Reprocessing', from FY 1993 until FY 2000. (author)

  17. Tuning Neural Phase Entrainment to Speech.

    Science.gov (United States)

    Falk, Simone; Lanzilotti, Cosima; Schön, Daniele

    2017-08-01

    Musical rhythm positively impacts on subsequent speech processing. However, the neural mechanisms underlying this phenomenon are so far unclear. We investigated whether carryover effects from a preceding musical cue to a speech stimulus result from a continuation of neural phase entrainment to periodicities that are present in both music and speech. Participants listened and memorized French metrical sentences that contained (quasi-)periodic recurrences of accents and syllables. Speech stimuli were preceded by a rhythmically regular or irregular musical cue. Our results show that the presence of a regular cue modulates neural response as estimated by EEG power spectral density, intertrial coherence, and source analyses at critical frequencies during speech processing compared with the irregular condition. Importantly, intertrial coherences for regular cues were indicative of the participants' success in memorizing the subsequent speech stimuli. These findings underscore the highly adaptive nature of neural phase entrainment across fundamentally different auditory stimuli. They also support current models of neural phase entrainment as a tool of predictive timing and attentional selection across cognitive domains.

  18. Progress in the development of a reactivity capability in the SAM-CE system for validating fuel management codes. Interim report

    International Nuclear Information System (INIS)

    Lichtenstein, H.; Steinberg, H.; Troubetzkoy, E.; Cohen, M.O.; Chui, C.

    1978-02-01

    The SAM-CE Monte Carlo system (for three dimensional neutron, gamma ray and electron transport) has been expanded to include a reactivity capability. The implemented code modifications have effected the following improvements: (a) Doppler broadening of ENDF/B-IV based nuclear data (including fission); (b) probability table representation for the unresolved resonance range; (c) utilization of thermal scattering law data for the moderator; (d) free gas model in the absence of thermal scattering law data; (e) generalization of the nuclear element data tape structure to facilitate data management; (f) generalization of data management routines; (g) extension of the SAM-CE Complex Combinatorial Geometry capability to facilitate treatment of hexagonal lattices; (h) simultaneous use of 4 different eigenvalue estimators; (i) estimation of the eigenfunction in user prescribed spatial domains; and (j) variance reduction via stratification of source (position, energy, direction) and absorption (based on a quota sampling technique), as well as optional suppression of absorption. The new coding has undergone extensive testing, both specific (via drivers and idealized data) and integral (via comparison with previous computations). Base data have been examined for internal consistency and checked for reasonableness. A documented TRX-1 benchmark calculation has been performed. Agreement with other calculations, as well as with experiment, has served to validate the reactivity mode of SAM-CE. Further refinement of the cross section data processing component of SAM-CE (i.e., SAM-X) is suggested

  19. Recent advances in fuel product and manufacturing process development

    International Nuclear Information System (INIS)

    Slember, R.J.; Doshi, P.K.

    1987-01-01

    This paper discusses advancements in commercial nuclear fuel products and manufacturing made by the Westinghouse Electric Corporation in response to the commercial nuclear fuel industry's demand for high reliability, increased plant availability and improved operating flexibility. The features and benefits of Westinghouse's most advanced fuel products--VANTAGE 5 for PWR plants and QUAD+ for BWR plants--are described, as well as 'high performance' fuel concepts now under development for delivery in the late 1980s. The paper also disusses the importance of in-process quality control throughout manufacturing towards reducing product variability and improving fuel reliability. (author)

  20. Process for humidifying a gaseous fuel stream

    International Nuclear Information System (INIS)

    Sederquist, R. A.

    1985-01-01

    A fuel gas stream for a fuel cell is humidified by a recirculating hot liquid water stream using the heat of condensation from the humidified stream as the heat to vaporize the liquid water. Humidification is accomplished by directly contacting the liquid water with the dry gas stream in a saturator to evaporate a small portion of water. The recirculating liquid water is reheated by direct contact with the humidified gas stream in a condenser, wherein water is condensed into the liquid stream. Between the steps of humidifying and condensing water from the gas stream it passes through the fuel cell and additional water, in the form of steam, is added thereto

  1. Processes of the excitation energy migration and transfer in Ce3+-doped alkali gadolinium phosphates studied with time-resolved photoluminescence spectroscopy technique

    International Nuclear Information System (INIS)

    Stryganyuk, G.; Shalapska, T.; Voloshinovskii, A.; Gektin, A.; Krasnikov, A.; Zazubovich, S.

    2011-01-01

    Spectral-kinetic characteristics of Gd 3+ and Ce 3+ luminescence from a series of Ce 3+ -doped alkali gadolinium phosphates of MGdP 4 O 12 type (M=Li, Na, Cs) have been studied within 4.2-300 K temperature range using time-resolved luminescence spectroscopy techniques. The processes of energy migration along the Gd 3+ sub-lattice and energy transfer between the Gd 3+ and Ce 3+ ions have been investigated. Peculiarities of these processes have been compared for MGdP 4 O 12 phosphate hosts with different alkali metal ions. A contribution of different levels from the 6 P j multiplet of the lowest Gd 3+ excited state into the energy migration and transfer processes has been clarified. The phonon-assisted occupation of high-energy 6 P 5/2,3/2 levels by Gd 3+ in the excited 6 P j state has been revealed as a shift of Gd 3+6 P j → 8 S 7/2 emission into the short-wavelength spectral range upon the temperature increase. The relaxation of excited Gd 3+ via phonon-assisted population of Gd 3+6 P 5/2 level (next higher one to the lowest excited 6 P 7/2 ) is supposed to be responsible for the rise in probability of energy migration within the Gd 3+ sub-lattice initiating the Gd 3+ →Ce 3+ energy transfer at T 3+ →Ce 3+ energy transfer at T>150 K is explained by the increase in probability of Gd 3+ relaxation into the highest 6 P 3/2 level of the 6 P j multiplet. An efficient reversed Ce 3+ →Gd 3+ energy transfer has been revealed for the studied phosphates at 4.2 K. - Highlights: →We investigate the Gd 3+ -Ce 3+ energy transfer in alkali gadolinium phosphates. → Thermal population of Gd 3+6 P 5/2 level improves migration along the Gd sub-lattice. → Increasing overlap of Gd 3+ and Ce 3+ states enhances the Gd 3+ -Ce 3+ energy transfer. → In LiGdP 4 O 12 :Ce and NaGdP 4 O 12 :Ce an efficient Ce 3+ -Gd 3+ transfer occurs at 4-300 K. → An effective reverse Gd 3+ -Ce 3+ energy transfer becomes possible at T>150 K.

  2. DUPIC nuclear fuel manufacturing and process technology development

    International Nuclear Information System (INIS)

    Yang, Myung Seung; Park, J. J.; Lee, J. W.

    2000-05-01

    In this study, DUPIC fuel fabrication technology and the active fuel laboratory were developed for the study of spent nuclear fuel. A new nuclear fuel using highly radioactive nuclear materials can be studied at the active fuel laboratory. Detailed DUPIC fuel fabrication process flow was developed considering the manufacturing flow, quality control process and material accountability. The equipment layout of about twenty DUPIC equipment at IMEF M6 hot cell was established for the minimization of the contamination during DUPIC processes. The characteristics of the SIMFUEL powder and pellets was studied in terms of milling conditions. The characteristics of DUPIC powder and pellet was studied by using 1 kg of spent PWR fuel at PIEF nr.9405 hot cell. The results were used as reference process conditions for following DUPIC fuel fabrication at IMEF M6. Based on the reference fabrication process conditions, the main DUPIC pellet fabrication campaign has been started at IMEF M6 using 2 kg of spent PWR fuel since 2000 January. As of March 2000, about thirty DUPIC pellets were successfully fabricated

  3. DUPIC nuclear fuel manufacturing and process technology development

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Myung Seung; Park, J. J.; Lee, J. W. [and others

    2000-05-01

    In this study, DUPIC fuel fabrication technology and the active fuel laboratory were developed for the study of spent nuclear fuel. A new nuclear fuel using highly radioactive nuclear materials can be studied at the active fuel laboratory. Detailed DUPIC fuel fabrication process flow was developed considering the manufacturing flow, quality control process and material accountability. The equipment layout of about twenty DUPIC equipment at IMEF M6 hot cell was established for the minimization of the contamination during DUPIC processes. The characteristics of the SIMFUEL powder and pellets was studied in terms of milling conditions. The characteristics of DUPIC powder and pellet was studied by using 1 kg of spent PWR fuel at PIEF nr.9405 hot cell. The results were used as reference process conditions for following DUPIC fuel fabrication at IMEF M6. Based on the reference fabrication process conditions, the main DUPIC pellet fabrication campaign has been started at IMEF M6 using 2 kg of spent PWR fuel since 2000 January. As of March 2000, about thirty DUPIC pellets were successfully fabricated.

  4. Fluid Dynamics of Pressurized, Entrained Coal Gasifiers

    International Nuclear Information System (INIS)

    1997-01-01

    Pressurized, entrained gasification is a promising new technology for the clean and efficient combustion of coal. Its principle is to operate a coal gasifier at a high inlet gas velocity to increase the inflow of reactants, and at an elevated pressure to raise the overall efficiency of the process. Unfortunately, because of the extraordinary difficulties involved in performing measurements in hot, pressurized, high-velocity pilot plants, its fluid dynamics are largely unknown. Thus the designer cannot predict with certainty crucial phenomena like erosion, heat transfer and solid capture. In this context, we are conducting a study of the fluid dynamics of Pressurized Entrained Coal Gasifiers (PECGs). The idea is to simulate the flows in generic industrial PECGs using dimensional similitude. To this end, we employ a unique entrained gas-solid flow facility with the flexibility to recycle--rather than discard--gases other than air. By matching five dimensionless parameters, suspensions in mixtures of helium, carbon dioxide and sulfur hexafluoride simulate the effects of pressure and scale-upon the fluid dynamics of PECGs. Because it operates under cold, atmospheric conditions, the laboratory facility is ideal for detailed measurements

  5. An Automated Process for Generation of New Fuel Breakdown Mechanisms

    National Research Council Canada - National Science Library

    Violi, Angela

    2006-01-01

    .... It combines advanced computational techniques in a synergistic study of the critical processes in fuel decomposition at a level of detail that can help distinguish, correct, and quantify mechanisms for these processes...

  6. Differential entrainment of neuroelectric delta oscillations in developmental dyslexia.

    Directory of Open Access Journals (Sweden)

    Fruzsina Soltész

    Full Text Available Oscillatory entrainment to the speech signal is important for language processing, but has not yet been studied in developmental disorders of language. Developmental dyslexia, a difficulty in acquiring efficient reading skills linked to difficulties with phonology (the sound structure of language, has been associated with behavioural entrainment deficits. It has been proposed that the phonological 'deficit' that characterises dyslexia across languages is related to impaired auditory entrainment to speech at lower frequencies via neuroelectric oscillations (<10 Hz, 'temporal sampling theory'. Impaired entrainment to temporal modulations at lower frequencies would affect the recovery of the prosodic and syllabic structure of speech. Here we investigated event-related oscillatory EEG activity and contingent negative variation (CNV to auditory rhythmic tone streams delivered at frequencies within the delta band (2 Hz, 1.5 Hz, relevant to sampling stressed syllables in speech. Given prior behavioural entrainment findings at these rates, we predicted functionally atypical entrainment of delta oscillations in dyslexia. Participants performed a rhythmic expectancy task, detecting occasional white noise targets interspersed with tones occurring regularly at rates of 2 Hz or 1.5 Hz. Both groups showed significant entrainment of delta oscillations to the rhythmic stimulus stream, however the strength of inter-trial delta phase coherence (ITC, 'phase locking' and the CNV were both significantly weaker in dyslexics, suggestive of weaker entrainment and less preparatory brain activity. Both ITC strength and CNV amplitude were significantly related to individual differences in language processing and reading. Additionally, the instantaneous phase of prestimulus delta oscillation predicted behavioural responding (response time for control participants only.

  7. Fuel processing for molten-salt reactors

    International Nuclear Information System (INIS)

    Hightower, J.R. Jr.

    1975-01-01

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

  8. A FIRE-ACE/SHEBA Case Study of Mixed-Phase Arctic Boundary Layer Clouds: Entrainment Rate Limitations on Rapid Primary Ice Nucleation Processes

    Science.gov (United States)

    Fridlin, Ann; vanDiedenhoven, Bastiaan; Ackerman, Andrew S.; Avramov, Alexander; Mrowiec, Agnieszka; Morrison, Hugh; Zuidema, Paquita; Shupe, Matthew D.

    2012-01-01

    Observations of long-lived mixed-phase Arctic boundary layer clouds on 7 May 1998 during the First International Satellite Cloud Climatology Project (ISCCP) Regional Experiment (FIRE)Arctic Cloud Experiment (ACE)Surface Heat Budget of the Arctic Ocean (SHEBA) campaign provide a unique opportunity to test understanding of cloud ice formation. Under the microphysically simple conditions observed (apparently negligible ice aggregation, sublimation, and multiplication), the only expected source of new ice crystals is activation of heterogeneous ice nuclei (IN) and the only sink is sedimentation. Large-eddy simulations with size-resolved microphysics are initialized with IN number concentration N(sub IN) measured above cloud top, but details of IN activation behavior are unknown. If activated rapidly (in deposition, condensation, or immersion modes), as commonly assumed, IN are depleted from the well-mixed boundary layer within minutes. Quasi-equilibrium ice number concentration N(sub i) is then limited to a small fraction of overlying N(sub IN) that is determined by the cloud-top entrainment rate w(sub e) divided by the number-weighted ice fall speed at the surface v(sub f). Because w(sub c) 10 cm/s, N(sub i)/N(sub IN)<< 1. Such conditions may be common for this cloud type, which has implications for modeling IN diagnostically, interpreting measurements, and quantifying sensitivity to increasing N(sub IN) (when w(sub e)/v(sub f)< 1, entrainment rate limitations serve to buffer cloud system response). To reproduce observed ice crystal size distributions and cloud radar reflectivities with rapidly consumed IN in this case, the measured above-cloud N(sub IN) must be multiplied by approximately 30. However, results are sensitive to assumed ice crystal properties not constrained by measurements. In addition, simulations do not reproduce the pronounced mesoscale heterogeneity in radar reflectivity that is observed.

  9. Modeling of large-scale oxy-fuel combustion processes

    DEFF Research Database (Denmark)

    Yin, Chungen

    2012-01-01

    Quite some studies have been conducted in order to implement oxy-fuel combustion with flue gas recycle in conventional utility boilers as an effective effort of carbon capture and storage. However, combustion under oxy-fuel conditions is significantly different from conventional air-fuel firing......, among which radiative heat transfer under oxy-fuel conditions is one of the fundamental issues. This paper demonstrates the nongray-gas effects in modeling of large-scale oxy-fuel combustion processes. Oxy-fuel combustion of natural gas in a 609MW utility boiler is numerically studied, in which...... calculation of the oxy-fuel WSGGM remarkably over-predicts the radiative heat transfer to the furnace walls and under-predicts the gas temperature at the furnace exit plane, which also result in a higher incomplete combustion in the gray calculation. Moreover, the gray and non-gray calculations of the same...

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

    Directory of Open Access Journals (Sweden)

    A. V. Zolin

    2015-01-01

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

  11. PWR-to-PWR fuel cycle model using dry process

    International Nuclear Information System (INIS)

    Iqbal, M.; Jeong, Chang Joon; Rho, Gyu Hong

    2002-03-01

    PWR-to-PWR fuel cycle model has been developed to recycle the spent fuel using the dry fabrication process. Two types of fuels were considered; first fuel was based on low initial enrichment with low discharge burnup and second one was based on more initial enrichment with high discharge burnup in PWR. For recycling calculations, the HELIOS code was used, in which all of the available fission products were considered. The decay of 10 years was applied for reuse of the spent fuel. Sensitivity analysis for the fresh feed material enrichment has also been carried out. If enrichment of the mixing material is increased the saving of uranium reserves would be decreased. The uranium saving of low burned fuel increased from 4.2% to 7.4% in fifth recycling step for 5 wt% to 19.00wt% mixing material enrichment. While for high burned fuel, there was no uranium saving, which implies that higher uranium enrichment required than 5 wt%. For mixing of 15 wt% enriched fuel, the required mixing is about 21.0% and 37.0% of total fuel volume for low and high burned fuel, respectively. With multiple recycling, reductions in waste for low and high burned fuel became 80% and 60%, for first recycling, respectively. In this way, waste can be reduced more and the cost of the waste disposal reduction can provide the economic balance

  12. A Brief Review of Past INL Work Assessing Radionuclide Content in TMI-2 Melted Fuel Debris: The Use of 144Ce as a Surrogate for Pu Accountancy

    Energy Technology Data Exchange (ETDEWEB)

    D. L. Chichester; S. J. Thompson

    2013-09-01

    This report serves as a literature review of prior work performed at Idaho National Laboratory, and its predecessor organizations Idaho National Engineering Laboratory (INEL) and Idaho National Engineering and Environmental Laboratory (INEEL), studying radionuclide partitioning within the melted fuel debris of the reactor of the Three Mile Island 2 (TMI-2) nuclear power plant. The purpose of this review is to document prior published work that provides supporting evidence of the utility of using 144Ce as a surrogate for plutonium within melted fuel debris. When the TMI-2 accident occurred no quantitative nondestructive analysis (NDA) techniques existed that could assay plutonium in the unconventional wastes from the reactor. However, unpublished work performed at INL by D. W. Akers in the late 1980s through the 1990s demonstrated that passive gamma-ray spectrometry of 144Ce could potentially be used to develop a semi-quantitative correlation for estimating plutonium content in these materials. The fate and transport of radioisotopes in fuel from different regions of the core, including uranium, fission products, and actinides, appear to be well characterized based on the maximum temperature reached by fuel in different parts of the core and the melting point, boiling point, and volatility of those radioisotopes. Also, the chemical interactions between fuel, fuel cladding, control elements, and core structural components appears to have played a large role in determining when and how fuel relocation occurred in the core; perhaps the most important of these reaction appears to be related to the formation of mixed-material alloys, eutectics, in the fuel cladding. Because of its high melting point, low volatility, and similar chemical behavior to plutonium, the element cerium appears to have behaved similarly to plutonium during the evolution of the TMI-2 accident. Anecdotal evidence extrapolated from open-source literature strengthens this logical feasibility for

  13. Cortical entrainment to music and its modulation by expertise.

    Science.gov (United States)

    Doelling, Keith B; Poeppel, David

    2015-11-10

    Recent studies establish that cortical oscillations track naturalistic speech in a remarkably faithful way. Here, we test whether such neural activity, particularly low-frequency (music and whether experience modifies such a cortical phenomenon. Music of varying tempi was used to test entrainment at different rates. In three magnetoencephalography experiments, we recorded from nonmusicians, as well as musicians with varying years of experience. Recordings from nonmusicians demonstrate cortical entrainment that tracks musical stimuli over a typical range of tempi, but not at tempi below 1 note per second. Importantly, the observed entrainment correlates with performance on a concurrent pitch-related behavioral task. In contrast, the data from musicians show that entrainment is enhanced by years of musical training, at all presented tempi. This suggests a bidirectional relationship between behavior and cortical entrainment, a phenomenon that has not previously been reported. Additional analyses focus on responses in the beta range (∼15-30 Hz)-often linked to delta activity in the context of temporal predictions. Our findings provide evidence that the role of beta in temporal predictions scales to the complex hierarchical rhythms in natural music and enhances processing of musical content. This study builds on important findings on brainstem plasticity and represents a compelling demonstration that cortical neural entrainment is tightly coupled to both musical training and task performance, further supporting a role for cortical oscillatory activity in music perception and cognition.

  14. Alteration in fuel processing at Tokai Works of Mitsubishi Nuclear Fuel Co., Ltd

    International Nuclear Information System (INIS)

    1977-01-01

    The report of the Committee on Examination of Nuclear Fuel Safety to the Atomic Energy Commission of Japan concerning the alteration is given, which is attached to the reply from the commission to the prime minister, and its safety was confirmed. The alterations are installation of the storage for transport containers containing fuel assemblies, construction of radiation control and other buildings; and improvement and installation of the facilities for chemical-processing, pellet fabrication, fuel assembling, and storage. (Mori, K.)

  15. A Pd/C-CeO2 Anode Catalyst for High-Performance Platinum-Free Anion Exchange Membrane Fuel Cells.

    Science.gov (United States)

    Miller, Hamish A; Lavacchi, Alessandro; Vizza, Francesco; Marelli, Marcello; Di Benedetto, Francesco; D'Acapito, Francesco; Paska, Yair; Page, Miles; Dekel, Dario R

    2016-05-10

    One of the biggest obstacles to the dissemination of fuel cells is their cost, a large part of which is due to platinum (Pt) electrocatalysts. Complete removal of Pt is a difficult if not impossible task for proton exchange membrane fuel cells (PEM-FCs). The anion exchange membrane fuel cell (AEM-FC) has long been proposed as a solution as non-Pt metals may be employed. Despite this, few examples of Pt-free AEM-FCs have been demonstrated with modest power output. The main obstacle preventing the realization of a high power density Pt-free AEM-FC is sluggish hydrogen oxidation (HOR) kinetics of the anode catalyst. Here we describe a Pt-free AEM-FC that employs a mixed carbon-CeO2 supported palladium (Pd) anode catalyst that exhibits enhanced kinetics for the HOR. AEM-FC tests run on dry H2 and pure air show peak power densities of more than 500 mW cm(-2) . © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Fuel Rod Performance Evaluation of CE 16 x 16 LTA Operated at Steady State Using Transuranus and Pad Codes

    Energy Technology Data Exchange (ETDEWEB)

    Krasnorutskyy, V.; Slyeptsov, O. [Nuclear Fuel Cycle Science and Technology Establishment (NFCSTE), National Science Center, Kharkhov Institute of Physics and Technology (NSC KIPT), Kharkhov (Ukraine)

    2013-03-15

    The report performed under IAEA research contract No. 15370 describes the results of fuel performance evaluation of PWR fuel rods operated at steady state up to discharge burnup of {approx}60 GWD/MTU using the codes of TRANSURANUS designed by ITU and PAD designed by Westinghouse. The experimental results from US-PWR 16x16 LTA Extended Burnup Demonstration Program presented in the IFPE database of the OECD/NEA have been utilized for assessing the codes themselves during simulation of such properties as rod burnup, cladding corrosion, fuel densification and swelling, cladding irradiation growth and strain, FGR and RIP. The results obtained by PAD showed that the code properly simulates rod burnup, cladding irradiation growth and cladding oxidation with Standard Zr-4 material. The calculated burnup values along the fuel stack vary within {+-} 5% of the rod average burnup. The predicted values of the rod axial growth are (0.88-0.94) % and within the measured ones obtained in the burnup range of (50 - 60) GWD/MTU. With allowance made for probability of crud deposition and hot channel hydraulic diameter variation, the axial distribution of oxide layer is predicted well. For the nominal rod dimensions and operation conditions, the calculated peak oxide thickness is slightly overestimated based on the BE corrosion model parameters. The WEC fuel swelling and densification model together with the US NRC one, which is incorporated in the code, were used to assess the change in fuel pellet density ({Delta}{rho}) and fuel volume ({Delta}V{sub F}/V) vs. burnup as well as the rod void volume change, {Delta}V{sub V}/V, and the cladding outer diameter (OD) variation along the fuel stack. (author)

  17. Process for assembling a nuclear fuel element

    International Nuclear Information System (INIS)

    Wachtendonk, H.J. von.

    1984-01-01

    Before insertion into the spacers, the fuel rocks are coated with a self-hardening layer of water-soluble polyvinyl and/or polyether polymer to prevent scratches on the cladding tubes. After insertion, the protective conting is removed by means of water. (orig.) [de

  18. State of the art of UO2 fuel fabrication processes

    International Nuclear Information System (INIS)

    Henke, M.; Klemm, U.

    1980-01-01

    Starting from the need of UO 2 for thermal power reactors in the period from 1980 to 1990 and the role of UF 6 conversion into UO 2 within the fuel cycle, the state-of-the-art of the three established industrial processes - ADU process, AUC process, IDR process - is assessed. The number of process stages and requirements on process management are discussed. In particular, the properties of the fabricated UO 2 powders, their influence on the following pellet production and on operational behaviour of the fuel elements under reactor conditions are described. Hence, an evaluation of the three essential conversion processes is derived. (author)

  19. Timescales of Massive Human Entrainment

    DEFF Research Database (Denmark)

    Fusaroli, Riccardo; Perlman, Marcus; Mislove, Alan

    2014-01-01

    of distinct scales, in an exquisitely time locked fashion. Using a large scale database of human communication data, we analyze and describe three different time scales of human entrainment in electronic media. We sought a distinct shared experience that provided a test bed for quantifying large scale human...

  20. Processing of spent nuclear fuel from light water reactors

    International Nuclear Information System (INIS)

    Sraier, V.

    1978-11-01

    A comprehensive review is given of the reprocessing of spent nuclear fuel from LWR's (covering references up to No. 18 (1977) of INIS inclusively). Particular attention is devoted to waste processing, safety, and reprocessing plants. In the addendum, the present status is shown on the example of KEWA, the projected large German fuel reprocessing plant. (author)

  1. Process for automatic filling of nuclear fuel rod cans

    International Nuclear Information System (INIS)

    Bezold, H.

    1977-01-01

    A drying section is inserted in the production line for the automation of the filling process for fuel rods with nuclear fuel pellets. The pellets are taken in a drum magazine to a drying furnace and then pushed out one after the other into the can to be filled. (TK) [de

  2. Synergistic energy conversion process using nuclear energy and fossil fuels

    International Nuclear Information System (INIS)

    Hori, Masao

    2007-01-01

    Because primary energies such as fossil fuels, nuclear energy and renewable energy are limited in quantity of supply, it is necessary to use available energies effectively for the increase of energy demand that is inevitable this century while keeping environment in good condition. For this purpose, an efficient synergistic energy conversion process using nuclear energy and fossil fuels together converted to energy carriers such are electricity, hydrogen, and synthetic fuels seems to be effective. Synergistic energy conversion processes containing nuclear energy were surveyed and effects of these processes on resource saving and the CO 2 emission reduction were discussed. (T.T.)

  3. Radioactive waste management of experimental DUPIC fuel fabrication process

    International Nuclear Information System (INIS)

    Lee, H. H.; Park, J. J.; Shin, J. M.; Yang, M. S.; Hong, K. P.

    2001-01-01

    The concept of DUPIC(Direct Use of Spent PWR Fuel in CANDU Reactors) is a dry processing technology to manufacture CANDU compatible DUPIC fuel from spent PWR fuel material. Real spent PWR fuel was used in IMEF M6 hot cell to carry out DUPIC experiment. Afterwards, about 200 kg-U of spent PWR fuel is supposed to be used till 2006. This study has been conducted in some hot cells of PIEF and M6 cell of IMEF. There are various forms of nuclear material such as rod cut, powder, green pellet, sintered pellet, fabrication debris, fuel rod, fuel bundle, sample, and process waste produced from various manufacturing experiment of DUPIC fuel. After completing test, the above nuclear wastes and test equipment etc. will be classified as radioactive waste, transferred to storage facility and managed rigorously according to domestic and international laws until the final management policy is determined. It is desirable to review management options in advance for radioactive waste generated from manufacturing experiment of DUPIC nuclear fuel as well as residual nuclear material and dismantled equipment. This paper includes basic plan for DUPIC radwaste, arising source and estimated amount of radioactive waste, waste classification and packing, transport cask, transport procedures

  4. Method for pre-processing LWR spent fuel

    International Nuclear Information System (INIS)

    Otsuka, Katsuyuki; Ebihara, Hikoe.

    1986-01-01

    Purpose: To facilitate the decladding of spent fuel, cladding tube processing, and waste gas recovery, and to enable the efficient execution of main re-processing process thereafter. Constitution: Spent fuel assemblies are sent to a cutting process where they are cut into chips of easy-to-process size. The chips, in a thermal decladding process, undergo a thermal cycle processing in air with the processing temperatures increased and decreased within the range of from 700 deg C to 1200 deg C, oxidizing zircaloy comprising the cladding tubes into zirconia. The oxidized cladding tubes have a number of fine cracks and become very brittle and easy to loosen off from fuel pellets when even a slight mechanical force is applied thereto, thus changing into a form of powder. Processed products are then separated into zirconia sand and fuel pellets by a gravitational selection method or by a sifting method, the zirconia sand being sent to a waste processing process and the fuel pellets to a melting-refining process. (Yoshino, Y.)

  5. Safety analysis of IFR fuel processing in the Argonne National Laboratory Fuel Cycle Facility

    International Nuclear Information System (INIS)

    Charak, I; Pedersen, D.R.; Forrester, R.J.; Phipps, R.D.

    1993-01-01

    The Integral Fast Reactor (IFR) concept developed by Argonne National Laboratory (ANL) includes on-site processing and recycling of discharged core and blanket fuel materials. The process is being demonstrated in the Fuel Cycle Facility (FCF) at ANL's Idaho site. This paper describes the safety analyses that were performed in support of the FCF program; the resulting safety analysis report was the vehicle used to secure authorization to operate the facility and carry out the program, which is now under way. This work also provided some insights into safety-related issues of a commercial IFR fuel processing facility. These are also discussed

  6. Effects of Fuel Quantity on Soot Formation Process for Biomass-Based Renewable Diesel Fuel Combustion

    KAUST Repository

    Jing, Wei

    2016-12-01

    Soot formation process was investigated for biomass-based renewable diesel fuel, such as biomass to liquid (BTL), and conventional diesel combustion under varied fuel quantities injected into a constant volume combustion chamber. Soot measurement was implemented by two-color pyrometry under quiescent type diesel engine conditions (1000 K and 21% O2 concentration). Different fuel quantities, which correspond to different injection widths from 0.5 ms to 2 ms under constant injection pressure (1000 bar), were used to simulate different loads in engines. For a given fuel, soot temperature and KL factor show a different trend at initial stage for different fuel quantities, where a higher soot temperature can be found in a small fuel quantity case but a higher KL factor is observed in a large fuel quantity case generally. Another difference occurs at the end of combustion due to the termination of fuel injection. Additionally, BTL flame has a lower soot temperature, especially under a larger fuel quantity (2 ms injection width). Meanwhile, average soot level is lower for BTL flame, especially under a lower fuel quantity (0.5 ms injection width). BTL shows an overall low sooting behavior with low soot temperature compared to diesel, however, trade-off between soot level and soot temperature needs to be carefully selected when different loads are used.

  7. Gas turbine with two circuits and intermediate fuel conversion process

    International Nuclear Information System (INIS)

    Bachl, H.

    1978-01-01

    The combination of a fuel conversion process with a thermal process saves coolant and subsequent separation plant, in order to achieve the greatest possible use of the mechanical or electrical energy. The waste heat of a thermal circuit is taken to an endothermal chemical fuel conversion process arranged before a second circuit. The heat remaining after removal of the heat required for the chemical process is taken to a second thermal circuit. The reaction products of the chemical process which condense out during expansion in the second thermal process are selectively separated from the remaining gas mixture in the individual turbine stages. (HGOE) [de

  8. Entrainment and deposition rates of droplets in annular two-phase flow

    International Nuclear Information System (INIS)

    Kataoka, I.; Ishii, M.

    1986-01-01

    The droplet entrainment from a liquid film is important to the mass, momentum, and energy transfer process in annular two-phase flow. For example, the amount of entrainment as well as the rate of entrainment significantly affect the occurrences of the dryout, whereas the post-CHF heat transfer depends strongly on the entrainment and droplet sizes. Despite the importance of the entrainment rate, there have been no satisfactory correlations available in the literature. In view of these, correlations for entrainment rate covering both entrance region and equilibrium region were developed from a simple model in collaboration with data. Results show that the entrainment rate varies considerably in the entrainment-development region. However, at a certain distance from an inlet it attains an equilibrium value. A simple approximate correlation was obtained for the equilibrium state where entrainment rate and deposition rate becomes equal. The result indicates that the equilibrium entrainment rate is proportional to Weber number based on the hydraulic diameter of a tube. 34 references, 14 figures

  9. Systems and processes for conversion of ethylene feedstocks to hydrocarbon fuels

    Science.gov (United States)

    Lilga, Michael A.; Hallen, Richard T.; Albrecht, Karl O.; Cooper, Alan R.; Frye, John G.; Ramasamy, Karthikeyan Kallupalayam

    2018-04-03

    Systems, processes, and catalysts are disclosed for obtaining fuel and fuel blends containing selected ratios of open-chain and closed-chain fuel-range hydrocarbons suitable for production of alternate fuels including gasolines, jet fuels, and diesel fuels. Fuel-range hydrocarbons may be derived from ethylene-containing feedstocks and ethanol-containing feedstocks.

  10. Systems and processes for conversion of ethylene feedstocks to hydrocarbon fuels

    Science.gov (United States)

    Lilga, Michael A.; Hallen, Richard T.; Albrecht, Karl O.; Cooper, Alan R.; Frye, John G.; Ramasamy, Karthikeyan Kallupalayam

    2017-09-26

    Systems, processes, and catalysts are disclosed for obtaining fuels and fuel blends containing selected ratios of open-chain and closed-chain fuel-range hydrocarbons suitable for production of alternate fuels including gasolines, jet fuels, and diesel fuels. Fuel-range hydrocarbons may be derived from ethylene-containing feedstocks and ethanol-containing feedstocks.

  11. Rapid separation of pure 144Ce fraction from fuel dissolver solution for demonstration experiment on secular equilibrium

    International Nuclear Information System (INIS)

    Ashok Kumar, G.V.S.; Kumar, R.; Venkata Subramani, C.R.

    2015-01-01

    Radioactive equilibrium is a condition in which the activity ratio of parent to its daughter is maintained constant with time which occurs only when the parent half-life is greater than daughter half-life. It is transient equilibrium in the case of the ratio of their half-lives of parent to daughter being less than an order whereas it becomes secular equilibrium when it is more than an order. In the case of secular equilibrium, the ratio of the activities becomes unity whereas the same depends on the decay constants of the parent and daughter nuclide for the transient equilibrium. 144 Ce- 144 Pr pair is a good example for the demonstration of secular equilibrium

  12. Sol-gel process for thermal reactor fuel fabrication

    International Nuclear Information System (INIS)

    Mukerjee, S.K.

    2008-01-01

    Full text: Sol-gel processes have revolutionized conventional ceramic technology by providing extremely fine and uniform powders for the fabrication of ceramics. The use of this technology for nuclear fuel fabrication has also been explored in many countries. Unlike the conventional sol-gel process, sol-gel process for nuclear fuels tries to eliminate the preparation of powders in view of the toxic nature of the powders particularly those of plutonium and 233 U. The elimination of powder handling thus makes this process more readily amenable for use in glove boxes or for remote handling. In this process, the first step is the preparation of microspheres of the fuel material from a solution which is then followed by vibro-compaction of these microspheres of different sizes to obtain the required smear density of fuel inside a pin. The maximum achievable packing density of 92 % makes it suitable for fast reactors only. With a view to extend the applicability of sol-gel process for thermal reactor fuel fabrication the concept of converting the gel microspheres derived from sol-gel process, to the pellets, has been under investigation for several years. The unique feature of this process is that it combines the advantages of sol-gel process for the preparation of fuel oxide gel microspheres of reproducible quality with proven irradiation behavior of the pellet fuel. One of the important pre-requisite for the success of this process is the preparation of soft oxide gel microspheres suitable for conversion to dense pellets free from berry structure. Studies on the internal gelation process, one of the many variants of sol-gel process, for obtaining soft oxide gel microspheres suitable for gel pelletisation is now under investigation at BARC. Some of the recent findings related to Sol-Gel Microsphere Pelletisation (SGMP) in urania-plutonia and thoria-urania systems will be presented

  13. Doing Duo – a Case Study of Entrainment in William Forsythe’s Choreography Duo

    Directory of Open Access Journals (Sweden)

    Elizabeth eWaterhouse

    2014-10-01

    Full Text Available Entrainment theory focuses on processes in which interacting (i.e. coupled rhythmic systems stabilize, producing synchronization in the ideal sense, and forms of phase related rhythmic coordination in complex cases. In human action, entrainment involves spatiotemporal and social aspects, characterizing the meaningful activities of music, dance, and communication. How can the phenomenon of human entrainment be meaningfully studied in complex situations such as dance? We present an in-progress case study of entrainment in William Forsythe's choreography Duo, a duet in which coordinated rhythmic activity is achieved without an external musical beat and without touch-based interaction. Using concepts of entrainment from different disciplines as well as insight from Duo performer Riley Watts, we question definitions of entrainment in the context of dance. The functions of chorusing, turn-taking, complementary action, cues and alignments are discussed and linked to supporting annotated video material. While Duo challenges the definition of entrainment in dance as coordinated response to an external musical or rhythmic signal, it supports the definition of entrainment as coordinated interplay of motion and sound production by active agents (i.e., dancers in the field. Agreeing that human entrainment should be studied on multiple levels, we suggest that entrainment between the dancers in Duo is elastic in time and a propose how to test this hypothesis empirically. We do not claim that our proposed model of elasticity is applicable to all forms of human entrainment nor to all to examples of entrainment in dance. Rather, we suggest studying higher order phase correction (the stabilizing tendency of entrainment as a potential aspect to be incorporated into other models.

  14. Galvanic cell for processing of used nuclear fuel

    Science.gov (United States)

    Garcia-Diaz, Brenda L.; Martinez-Rodriguez, Michael J.; Gray, Joshua R.; Olson, Luke C.

    2017-02-07

    A galvanic cell and methods of using the galvanic cell is described for the recovery of uranium from used nuclear fuel according to an electrofluorination process. The galvanic cell requires no input energy and can utilize relatively benign gaseous fluorinating agents. Uranium can be recovered from used nuclear fuel in the form of gaseous uranium compound such as uranium hexafluoride, which can then be converted to metallic uranium or UO.sub.2 and processed according to known methodology to form a useful product, e.g., fuel pellets for use in a commercial energy production system.

  15. Electrochemical fluorination for processing of used nuclear fuel

    Science.gov (United States)

    Garcia-Diaz, Brenda L.; Martinez-Rodriguez, Michael J.; Gray, Joshua R.; Olson, Luke C.

    2016-07-05

    A galvanic cell and methods of using the galvanic cell is described for the recovery of uranium from used nuclear fuel according to an electrofluorination process. The galvanic cell requires no input energy and can utilize relatively benign gaseous fluorinating agents. Uranium can be recovered from used nuclear fuel in the form of gaseous uranium compound such as uranium hexafluoride, which can then be converted to metallic uranium or UO.sub.2 and processed according to known methodology to form a useful product, e.g., fuel pellets for use in a commercial energy production system.

  16. In situ screen-printed BaZr{sub 0.1}Ce{sub 0.7}Y{sub 0.2}O{sub 3-{delta}} electrolyte-based protonic ceramic membrane fuel cells with layered SmBaCo{sub 2}O{sub 5+x} cathode

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Bin; Dong, Yingchao; Zhang, Shangquan; Hu, Mingjun; Zhou, Yang; Meng, Guangyao [Department of Materials Science and Engineering, University of Science and Technology of China (USTC), Hefei, Anhui 230026 (China); Yan, Ruiqiang [Department of Materials Engineering, Taizhou University, Linhai, Zhejiang 317000 (China)

    2009-01-15

    In order to develop a simple and cost-effective route to fabricate protonic ceramic membrane fuel cells (PCMFCs) with layered SmBaCo{sub 2}O{sub 5+x} (SBCO) cathode, a dense BaZr{sub 0.1}Ce{sub 0.7}Y{sub 0.2}O{sub 3-{delta}} (BZCY) electrolyte was fabricated on a porous anode by in situ screen printing. The porous NiO-BaZr{sub 0.1}Ce{sub 0.7}Y{sub 0.2}O{sub 3-{delta}} (NiO-BZCY) anode was directly prepared from metal oxide (NiO, BaCO{sub 3}, ZrO{sub 2}, CeO{sub 2} and Y{sub 2}O{sub 3}) by a simple gel-casting process. An ink of metal oxide (BaCO{sub 3}, ZrO{sub 2}, CeO{sub 2} and Y{sub 2}O{sub 3}) powders was then employed to deposit BaZr{sub 0.1}Ce{sub 0.7}Y{sub 0.2}O{sub 3-{delta}} (BZCY) thin layer by an in situ reaction-sintering screen printing process on NiO-BZCY anode. The bi-layer with 25 {mu}m dense BZCY electrolyte was obtained by co-sintering at 1400 C for 5 h. With layered SBCO cathode synthesized by gel-casting on the bi-layer, single cells were assembled and tested with H{sub 2} as fuel and the static air as oxidant. A high open-circuit potential of 1.01 V, a maximum power density of 382 mW cm{sup -2}, and a low polarization resistance of the electrodes of 0.15 {omega} cm{sup 2} was achieved at 700 C. (author)

  17. Bugs and coal: processing fuels with biotechnology

    Energy Technology Data Exchange (ETDEWEB)

    Shepard, M

    1987-06-01

    Bioprocessing of coal is developing along several fronts, each of potential significance to utilities. Researchers have found a fungus, polyporous versicolor, which can liquefy certain kinds of coal and scientists have genetically engineered bacteria that remove sulfur and ash-forming metal impurities from coal. Research programs are being undertaken to find organisms that will convert lignite into gaseous methane to produce gaseous fuel more economically than the current coal gasification methods. Researchers looking for ways to remove sulfur from coal before it is burned are evaluating the use of a bacterium called thiobacillus ferroxidans to enhance the physical removal of pyrite. 2 refs.

  18. Pressurized water reactor fuel performance problems connected with fuel cladding corrosion processes

    International Nuclear Information System (INIS)

    Dobrevski, I.; Zaharieva, N.

    2008-01-01

    Generally, Pressurized Water Reactor (WWER, PWR) Fuel Element Performance is connected with fuel cladding corrosion and crud deposition processes. By transient to extended fuel cycles in nuclear power reactors, aiming to achieve higher burnup and better fuel utilization, the role of these processes increases significantly. This evolution modifies the chemical and electrochemical conditions in the reactor primary system, including change of fuel claddings' environment. The higher duty cores are always attended with increased boiling (sub-cooled nucleate boiling) mainly on the feed fuel assemblies. This boiling process on fuel cladding surfaces can cause different consequences on fuel element cladding's environment characteristics. In the case of boiling at the cladding surfaces without or with some cover of corrosion product deposition, the behavior of gases dissolved in water phase is strongly influenced by the vapor generation. The increase of vapor partial pressure will reduce the partial pressures of dissolved gases and will cause their stripping out. By these circumstances the concentrations of dissolved gases in cladding wall water layer can dramatically decrease, including also the case by which all dissolved gases to be stripped out. On the other hand it is known that the hydrogen is added to primary coolant in order to avoid the production of oxidants by radiolysis of water. It is clear that if boiling strips out dissolved hydrogen, the creation of oxidizing conditions at the cladding surfaces will be favored. In this case the local production of oxidants will be a result from local processes of water radiolysis, by which not only both oxygen (O 2 ) and hydrogen (H 2 ) but also hydrogen peroxide (H 2 O 2 ) will be produced. While these hydrogen and oxygen will be stripped out preferentially by boiling, the bigger part of hydrogen peroxide will remain in wall water phase and will act as the most important factor for creation of oxidizing conditions in fuel

  19. Advanced fuel cycle on the basis of pyroelectrochemical process for irradiated fuel reprocessing and vibropacking technology

    International Nuclear Information System (INIS)

    Mayorshin, A.A.; Skiba, O.V.; Tsykanov, V.A.; Golovanov, V.N.; Bychkov, A.V.; Kisly, V.A.; Bobrov, D.A.

    2000-01-01

    For advanced nuclear fuel cycle in SSC RIAR there is developed the pyroelectrochemical process to reprocess irradiated fuel and produce granulated oxide fuel UO 2 , PuO 2 or (U,Pu)O 2 from chloride melts. The basic technological stage is the extraction of oxides as a crystal product with the methods either of the electrolysis (UO 2 and UO 2 -PuO 2 ) or of the precipitating crystalIization (PuO 2 ). After treating the granulated fuel is ready for direct use to manufacture vibropacking fuel pins. Electrochemical model for (U,Pu)O 2 coprecipitation is described. There are new processes being developed: electroprecipitation of mixed oxides - (U,Np)O 2 , (U,Pu,Np)O 2 , (U,Am)O 2 and (U,Pu,Am)O 2 . Pyroelectrochemical production of mixed actinide oxides is used both for reprocessing spent fuel and for producing actinide fuel. Both the efficiency of pyroelectrochemical methods application for reprocessing nuclear fuel and of vibropac technology for plutonium recovery are estimated. (author)

  20. Research on plant of metal fuel fabrication using casting process

    International Nuclear Information System (INIS)

    Senda, Yasuhide; Mori, Yukihide

    2003-12-01

    This document presents the plant concept of metal fuel fabrication system (38tHM/y) using casting process in electrolytic recycle, which based on recent studies of its equipment design and quality control system. And we estimate the cost of its construction and operation, including costs of maintenance, consumed hardware and management of waste. The content of this work is as follows. (1) Designing of fuel fabrication equipment: We make material flow diagrams of the fuel fabrication plant and rough designs of the injection casting furnace, demolder and inspection equipment. (2) Designing of resolution system of liquid waste, which comes from analytical process facility. Increased analytical items, we rearrange analytical process facility, estimate its chemicals and amount of waste. (3) Arrangement of equipments: We made a arrangement diagram of the metal fuel fabrication equipments in cells. (4) Estimation of cost data: We estimated cost to construct the facility and to operate it. (author)

  1. Scintillation properties of Zr co-doped Ce:(Gd, La)_2Si_2O_7 grown by the Czochralski process

    International Nuclear Information System (INIS)

    Murakami, Rikito; Kurosawa, Shunsuke; Shoji, Yasuhiro; Jary, Vitezslav; Ohashi, Yuji; Pejchal, Jan; Yokota, Yuui; Kamada, Kei; Nikl, Martin; Yoshikawa, Akira

    2016-01-01

    (Gd_0_._7_5,Ce_0_._0_1_5,La_0_._2_3_5)_2Si_2O_7 (Ce:La-GPS) single crystals co-doped with 0, 100, 200, 500 and 1000 ppm Zr were grown by the Czochralski process, and their scintillation properties were investigated. We investigated the co-doping effect of a stable tetravalent ion in Ce:La-GPS for the first time. The scintillation decay times in the faster component were shortened with increasing the Zr concentration. While the non-co-doped sample showed ∼63 ns day time, the Zr 100, 200, 500 and 1000 ppm co-doped samples showed ∼61, ∼59, ∼57, ∼54 ns, respectively. Additionally, light output, photon nonproportional response (PNR) and other optical properties were investigated. - Highlights: • Czochralski growth of Ce:(Gd,La)_2Si_2O_7 single crystals. • Co-doping effect of a stable tetravalent ion in Ce:(Gd,La)_2Si_2O_7 system. • Photon nonproportional response of Zr co-doped Ce:(Gd,La)_2Si_2O_7.

  2. A high performance BaZr0.1Ce0.7Y0.2O3-δ-based solid oxide fuel cell with a cobalt-free Ba0.5Sr0.5FeO3-δ–Ce0.8Sm0.2O2-δ composite cathode

    NARCIS (Netherlands)

    Sun, Wenping; Shi, Zhen; Fang, S.; Yan, Litao; Zhu, Zhiwen; Liu, Wei

    2010-01-01

    A cobalt-free Ba0.5Sr0.5FeO3-δ–Ce0.8Sm0.2O2-δ (BSF–SDC) composite is employed as a cathode for an anode-supported proton-conducting solid oxide fuel cells (H-SOFCs) using BaZr0.1Ce0.7Y0.2O3-δ (BZCY) as the electrolyte. The chemical compatibility between BSF and SDC is evaluated. The XRD results show

  3. Viscous entrainment on hairy surfaces

    Science.gov (United States)

    Nasto, Alice; Brun, P.-T.; Hosoi, A. E.

    2018-02-01

    Nectar-drinking bats and honeybees have tongues covered with hairlike structures, enhancing their ability to take up viscous nectar by dipping. Using a combination of model experiments and theory, we explore the physical mechanisms that govern viscous entrainment in a hairy texture. Hairy surfaces are fabricated using laser cut molds and casting samples with polydimethylsiloxane (PDMS) elastomer. We model the liquid trapped within the texture using a Darcy-Brinkmann-like approach and derive the drainage flow solution. The amount of fluid that is entrained is dependent on the viscosity of the fluid, the density of the hairs, and the withdrawal speed. Both experiments and theory reveal an optimal hair density to maximize fluid uptake.

  4. Production process and quality control for the HTTR fuel

    International Nuclear Information System (INIS)

    Yoshimuta, S.; Suzuki, N.; Kaneko, M.; Fukuda, K.

    1991-01-01

    Development of the production and inspection technology for High Temperature Engineering Test Reactor (HTTR) fuel has been carried out by cooperative work between Japan Atomic Energy Research Institute (JAERI) and Nuclear Fuel Industries, Ltd (NFI). The performance and the quality level of the developed fuel are well established to meet the design requirements of the HTTR. For the commercial scale production of the fuel, statistical quality control and quality assurance must be carefully considered in order to assure the safety of the HTTR. It is also important to produce the fuel under well controlled process condition. To meet these requirements in the production of the HTTR fuel, a new production process and quality control system is to be introduced in the new facilities. The main feature of the system is a computer integrated control system. Process control data at each production stage of products and semi-products are all gathered by terminal computers and processed by a host computer. The processed information is effectively used for the production, quality and accountancy control. With the aid of this system, all the products will be easily traceable from starting materials to final stages and the statistical evaluation of the quality of products becomes more reliable. (author). 8 figs

  5. IFR fuel cycle process equipment design environment and objectives

    International Nuclear Information System (INIS)

    Rigg, R.H.

    1993-01-01

    Argonne National laboratory (ANL) is refurbishing the hot cell facility originally constructed with the EBR-II reactor. When refurbishment is complete, the facility win demonstrate the complete fuel cycle for current generation high burnup metallic fuel elements. These are sodium bonded, stainless steel clad fuel pins of U-Zr or U-Pu-Zr composition typical of the fuel type proposed for a future Integral Fast Reactor (IFR) design. To the extent possible, the process equipment is being built at full commercial scale, and the facility is being modified to incorporate current DOE facility design requirements and modem remote maintenance principles. The current regulatory and safety environment has affected the design of the fuel fabrication equipment, most of which will be described in greater detail in subsequent papers in this session

  6. Model studying the processes arising during fuel element overheating

    International Nuclear Information System (INIS)

    Usynin, G.B.; Anoshkin, Yu.I.; Vlasichev, G.N.; Galitskikh, Yu.N.; Semenychev, M.A.

    1986-01-01

    A calculational technique for studying heating and melting of fuel elements in the BN type reactors during an accident with heat release failure and a simulator with central rod heater intended for out-of-pile experiments is developed. The time rangeof the characteristic melting steps for the most thermally stressed fuel element at the reactor nominal power is calculated. The experimental study of the fuel element melting using a simulator with a tungsten heater has proved that the technique for the simultor and fuel can melting, respectively, is correct. The developed technique is used for determining the geometrical values and operational conditions for experiments with simulators, when quantitative and qualitative characteristics of the process under study are rather close to those natural for fuel elements

  7. Nuclear reactor fuel cycle technology with pyroelectrochemical processes

    International Nuclear Information System (INIS)

    Skiba, O.V.; Maershin, A.A.; Bychkov, A.V.; Zhdanov, A.N.; Kislyj, V.A.; Vavilov, S.K.; Babikov, L.G.

    1999-01-01

    A group of dry technologies and processes of vibro-packing granulated fuel in combination with unique properties of vibro-packed FEs make it possible to implement a new comprehensive approach to the fuel cycle with plutonium fuel. Testing of a big number of FEs with vibro-packed U-Pu oxide fuel in the BOR-60 reactor, successful testing of experimental FSAs in the BN-600 rector, reliable operation of the experimental and research complex facilities allow to make the conclusion about a real possibility to develop a safe, economically beneficial U-Pu fuel cycle based on the technologies enumerated above and to use both reactor-grade and weapon-grade plutonium in nuclear reactors with a reliable control and accounting system [ru

  8. A droplet entrainment model for horizontal segregated flows

    Energy Technology Data Exchange (ETDEWEB)

    Höhne, Thomas, E-mail: T.Hoehne@hzdr.de [Helmholtz-Zentrum Dresden-Rossendorf (HZDR) – Institute of Fluid Dynamics, P.O. Box 510119, D-01314 Dresden (Germany); Hänsch, Susann [Imperial College, Department of Mechanical Engineering, South Kensington Campus, London SW7 2AZ (United Kingdom)

    2015-05-15

    Highlights: • We further developed the flow morphology detection model AIAD. • An advanced droplet entrainment model was introduced. • The new approach is applied against HAWAC experiments. - Abstract: One limitation in simulating horizontal segregated flows is that there is no treatment of droplet formation mechanisms at wavy surfaces. For self-generating waves and slugs, the interfacial momentum exchange and the turbulence parameters have to be modeled correctly. Furthermore, understanding the mechanism of droplet entrainment for heat and mass transfer processes is of great importance in the chemical and nuclear industry. The development of general computational fluid dynamics models is an essential precondition for the application of CFD codes to the modeling of flow related phenomena. The new formulation for the interfacial drag at the free surface and turbulence parameters within the algebraic interfacial area density model (AIAD) represents one step toward a more physical description of free surface flows including less empiricism. The AIAD approach allows the use of different physical models depending on the local fluid morphology inside a macro-scale multi-fluid framework. A further step of improving the modeling of free interfaces lies within the consideration of droplet entrainment mechanisms. In this paper a new sub-grid entrainment model is proposed, which assumes that due to liquid turbulence the interface gets rough and wavy leading to the formation of droplets. Therefore, the droplet entrainment model requires the consideration of an additional droplet phase, which is described with an own set of balance equations in the spirit of the particle model. Two local key factors determine the rate of droplet entrainment: the liquid turbulent kinetic energy as well as the outward velocity gradient of the liquid relative to the interface motion. The new droplet entrainment approach is included into CFD simulations for attempting to reproduce existing

  9. Photophysical and energy transfer processes in Ce{sup 3+} co-doped ZrO{sub 2}: Eu{sup 3+} nanorods

    Energy Technology Data Exchange (ETDEWEB)

    Ahemen, I.; Dejene, F.B. [University of the Free State-Qwaqwa Campus, Department of Physics, Phuthaditjhaba (South Africa)

    2017-02-15

    Cerium (III) ion co-doped ZrO{sub 2}: Eu{sup 3+} nanorods at varying Ce{sup 3+} ion concentrations were synthesized by a simple chemical dehydration route. Their structural, morphological and optical properties were investigated. Structural studies revealed a tetragonal phase with CeO{sub 2} phase grafted onto its surface. Field emission scanning electron microscopy images show nanorods of different dimensions. Diffraction peaks shifted towards smaller angles indicating the incorporation of the rare earth ions. Both Ce{sup 3+} (donor) and Eu{sup 3+} (activator) emission peaks were obtained when the samples were excited via the Ce{sup 3+} excitation band indicating energy transfer from the donor to activator. The process of energy transfer is both multipolar and exchange interactions. However, no significant enhancement of the activator's emission intensity, because concentration quenching process dominated the energy transfer process. The internal quantum efficiency, though low (20-25%), increased with increasing Ce{sup 3+} concentration. (orig.)

  10. Development of Voloxidation Process for Treatment of LWR Spent Fuel

    Energy Technology Data Exchange (ETDEWEB)

    Park, J. J.; Jung, I. H.; Shin, J. M. (and others)

    2007-08-15

    The objective of the project is to develop a process which provides a means to recover fuel from the cladding, and to simplify downstream processes by recovering volatile fission products. This work focuses on the process development in three areas ; the measurement and assessment of the release behavior for the volatile and semi-volatile fission products from the voloxidation process, the assessment of techniques to trap and recover gaseous fission products, and the development of process cycles to optimize fuel cladding separation and fuel particle size. High temperature adsorption method of KAERI was adopted in the co-design of OTS for hot experiment in INL. KAERI supplied 6 sets of filter for hot experiment. Three hot experiment in INL hot cell from the 25th of November for two weeks with attaching 4 KAERI staffs had been carried out. The results were promising. For example, trapping efficiency of Cs was 95% and that of I was 99%, etc.

  11. Analysis of the ATR fuel element swaging process

    International Nuclear Information System (INIS)

    Richins, W.D.; Miller, G.K.

    1995-12-01

    This report documents a detailed evaluation of the swaging process used to connect fuel plates to side plates in Advanced Test Reactor (ATR) fuel elements. The swaging is a mechanical process that begins with fitting a fuel plate into grooves in the side plates. Once a fuel plate is positioned, a lip on each of two side plate grooves is pressed into the fuel plate using swaging wheels to form the joints. Each connection must have a specified strength (measured in terms, of a pullout force capacity) to assure that these joints do not fail during reactor operation. The purpose of this study is to analyze the swaging process and associated procedural controls, and to provide recommendations to assure that the manufacturing process produces swaged connections that meet the minimum strength requirement. The current fuel element manufacturer, Babcock and Wilcox (B ampersand W) of Lynchburg, Virginia, follows established procedures that include quality inspections and process controls in swaging these connections. The procedures have been approved by Lockheed Martin Idaho Technologies and are designed to assure repeatability of the process and structural integrity of each joint. Prior to July 1994, ATR fuel elements were placed in the Hydraulic Test Facility (HTF) at the Idaho National Engineering Laboratory (AGNAIL), Test Reactor Area (TRA) for application of Boehmite (an aluminum oxide) film and for checking structural integrity before placement of the elements into the ATR. The results presented in this report demonstrate that the pullout strength of the swaged connections is assured by the current manufacturing process (with several recommended enhancements) without the need for- testing each element in the HTF

  12. Continuous tests of Phosphoric Acid - dihydrate process - from phosphatic concentrate of Itataia-CE ore

    International Nuclear Information System (INIS)

    Santos Benedetto, J. dos.

    1984-01-01

    A consolidation of principal studies and continuous tests done with phosphatic concentrated of Itataia ore intending phosphoric acid production by humid-route dihydrate way process is presented. The production of phosphoric acid is applied in uranium extraction process by solvents. (author) [pt

  13. Process for the fabrication of a nuclear fuel

    International Nuclear Information System (INIS)

    Hirose, Yasuo.

    1970-01-01

    Herein disclosed is a process for fabricating a nuclear fuel incorporating either uranium or plutonium. A pellet-like substrate consisting of a packed powder ceramic fuel such as uranium or plutonium is prepared with the horizontal surface of the body provided with a masking. Next, after impregnating the substrate voids with a solution consisting of a fissile material or mixture of fissile material and poison, the solvent is removed by a chemical deposition process which causes the impregnated material to migrate through capillary action toward the vicinity of the fuel body surface. Sintering and pyrolysis of the deposited material and masking are subsequently carried out to yield a fuel body having adjacent to its surface an intensely concentrated layer of either fissile material or a mixture of fissile material and poison. (Owens, K.J.)

  14. On board fuel processing for using in electric vehicles

    International Nuclear Information System (INIS)

    Paez, Daniel E.; Marquez, Marco A.

    1999-01-01

    The increase in vehicle population, the emission effects upon the environment, and the growing concern of industrialized nations to reduce oil dependency, are the arguments for the new developments that may change the automobile revolution within the next decades. However, the electricity to move the future vehicles must come from the processing of liquid fuels on board. Liquid fuels such as gasoline have the advantage of having good on-site system for distribution and supply directly to the vehicle and will compete for staying as the energy source of the future. What are the opportunities in R and D and how to take advantage of them are analyzed in this document. Liquid fuel processing technologies and fuel options are also described by PDVSA-INTEVEP

  15. Electrochemical characterization of Pr2CuO4–Ce0.9Gd0.1O1.95 composite cathodes for solid oxide fuel cells

    International Nuclear Information System (INIS)

    Kolchina, L.M.; Lyskov, N.V.; Petukhov, D.I.; Mazo, G.N.

    2014-01-01

    Highlights: • PCO–GDC composites are studied as a cathode for SOFCs. • The rate-determined step of the overall electrode process vs. temperature was defined. • PCO–GDC33 composite gave the lowest area surface resistance of 0.41 Ω cm 2 at 700 °C. • PCO–GDC33 is preferred to use as a cathode material for IT-SOFCs. - Abstract: Pr 2 CuO 4 –Ce 0.9 Gd 0.1 O 1.95 (PCO–GDC) composites screen printed on Ce 0.9 Gd 0.1 O 1.95 (GDC) electrolyte were considered as a cathode material for intermediate temperature solid oxide fuel cells (IT-SOFCs). Phase composition, microstructure and electrochemical properties were investigated by X-ray powder diffraction (XRD), scanning electron microscopy and AC impedance spectroscopy, respectively. The oxygen reduction on porous PCO–GDC electrode applied on CGO electrolyte was studied in a symmetrical cell configuration by AC impedance spectroscopy at OCV conditions at 670–730 °C and p O 2 =10 -2 -0.21atm. The charge transfer process and the dissociation of adsorbed molecular oxygen were found to be rate-determining steps of the oxygen reduction reaction. Results reveal that both GDC addition and electrode morphology have strong influence on area specific resistance (ASR) of the electrode/electrolyte interface. The lowest ASR value of 0.41 Ω cm 2 was achieved for the composition containing 33 wt.% GDC at 700 °S in air. The data obtained allow to consider the PCO–GDC33 composite as a promising cathode material for IT-SOFCs

  16. Capabilities for processing shipping casks at spent fuel storage facilities

    International Nuclear Information System (INIS)

    Baker, W.H.; Arnett, L.M.

    1978-01-01

    Spent fuel is received at a storage facility in heavily shielded casks transported either by rail or truck. The casks are inspected, cooled, emptied, decontaminated, and reshipped. The spent fuel is transferred to storage. The number of locations or space inside the building provided to perform each function in cask processing will determine the rate at which the facility can process shipping casks and transfer spent fuel to storage. Because of the high cost of construction of licensed spent fuel handling and storage facilities and the difficulty in retrofitting, it is desirable to correctly specify the space required. In this paper, the size of the cask handling facilities is specified as a function of rate at which spent fuel is received for storage. The minimum number of handling locations to achieve a given throughput of shipping casks has been determined by computer simulation of the process. The simulation program uses a Monte Carlo technique in which a large number of casks are received at a facility with a fixed number of handling locations in each process area. As a cask enters a handling location, the time to process the cask at that location is selected at random from the distribution of process time. Shipping cask handling times are based on experience at the General Electric Storage Facility, Morris, Illinois. Shipping cask capacity is based on the most recent survey available of the expected capability of reactors to handle existing rail or truck casks

  17. Product Characterization for Entrained Flow Coal/Biomass Co-Gasification

    Energy Technology Data Exchange (ETDEWEB)

    Maghzi, Shawn; Subramanian, Ramanathan; Rizeq, George; Singh, Surinder; McDermott, John; Eiteneer, Boris; Ladd, David; Vazquez, Arturo; Anderson, Denise; Bates, Noel

    2011-09-30

    The U.S. Department of Energy‘s National Energy Technology Laboratory (DOE NETL) is exploring affordable technologies and processes to convert domestic coal and biomass resources to high-quality liquid hydrocarbon fuels. This interest is primarily motivated by the need to increase energy security and reduce greenhouse gas emissions in the United States. Gasification technologies represent clean, flexible and efficient conversion pathways to utilize coal and biomass resources. Substantial experience and knowledge had been developed worldwide on gasification of either coal or biomass. However, reliable data on effects of blending various biomass fuels with coal during gasification process and resulting syngas composition are lacking. In this project, GE Global Research performed a complete characterization of the gas, liquid and solid products that result from the co-gasification of coal/biomass mixtures. This work was performed using a bench-scale gasifier (BSG) and a pilot-scale entrained flow gasifier (EFG). This project focused on comprehensive characterization of the products from gasifying coal/biomass mixtures in a high-temperature, high-pressure entrained flow gasifier. Results from this project provide guidance on appropriate gas clean-up systems and optimization of operating parameters needed to develop and commercialize gasification technologies. GE‘s bench-scale test facility provided the bulk of high-fidelity quantitative data under temperature, heating rate, and residence time conditions closely matching those of commercial oxygen-blown entrained flow gasifiers. Energy and Environmental Research Center (EERC) pilot-scale test facility provided focused high temperature and pressure tests at entrained flow gasifier conditions. Accurate matching of syngas time-temperature history during cooling ensured that complex species interactions including homogeneous and heterogeneous processes such as particle nucleation, coagulation, surface condensation, and

  18. Product Characterization for Entrained Flow Coal/Biomass Co-Gasification

    Energy Technology Data Exchange (ETDEWEB)

    Maghzi, Shawn [General Electric Global Research, Niskayuna, NY (United States); Subramanian, Ramanathan [General Electric Global Research, Niskayuna, NY (United States); Rizeq, George [General Electric Global Research, Niskayuna, NY (United States); Singh, Surinder [General Electric Global Research, Niskayuna, NY (United States); McDermott, John [General Electric Global Research, Niskayuna, NY (United States); Eiteneer, Boris [General Electric Global Research, Niskayuna, NY (United States); Ladd, David [General Electric Global Research, Niskayuna, NY (United States); Vazquez, Arturo [General Electric Global Research, Niskayuna, NY (United States); Anderson, Denise [General Electric Global Research, Niskayuna, NY (United States); Bates, Noel [General Electric Global Research, Niskayuna, NY (United States)

    2011-12-11

    The U.S. Department of Energy's National Energy Technology Laboratory (DOE NETL) is exploring affordable technologies and processes to convert domestic coal and biomass resources to high-quality liquid hydrocarbon fuels. This interest is primarily motivated by the need to increase energy security and reduce greenhouse gas emissions in the United States. Gasification technologies represent clean, flexible and efficient conversion pathways to utilize coal and biomass resources. Substantial experience and knowledge had been developed worldwide on gasification of either coal or biomass. However, reliable data on effects of blending various biomass fuels with coal during gasification process and resulting syngas composition are lacking. In this project, GE Global Research performed a complete characterization of the gas, liquid and solid products that result from the co-gasification of coal/biomass mixtures. This work was performed using a bench-scale gasifier (BSG) and a pilot-scale entrained flow gasifier (EFG). This project focused on comprehensive characterization of the products from gasifying coal/biomass mixtures in a high-temperature, high-pressure entrained flow gasifier. Results from this project provide guidance on appropriate gas clean-up systems and optimization of operating parameters needed to develop and commercialize gasification technologies. GE's bench-scale test facility provided the bulk of high-fidelity quantitative data under temperature, heating rate, and residence time conditions closely matching those of commercial oxygen-blown entrained flow gasifiers. Energy and Environmental Research Center (EERC) pilot-scale test facility provided focused high temperature and pressure tests at entrained flow gasifier conditions. Accurate matching of syngas time-temperature history during cooling ensured that complex species interactions including homogeneous and heterogeneous processes such as particle nucleation, coagulation, surface condensation

  19. Process and equipment for locating defective fuel rods of a reactor fuel element

    International Nuclear Information System (INIS)

    Jester, A.; Honig, H.

    1977-01-01

    By this equipment, well-known processes for determining defective fuel rods of a reactor fuel element are improved in such a fashion that defective fuel rods can be located individually, so that it is possible to replace them. The equipment consists of a cylindrical test vessel open above, which accommodates the element to be tested, so that an annular space is left between the latter's external circumference and the wall of the vessel, and so that the fuel rods project above the vessel. A bell in the shape of a frustrum of a cone is inverted over the test vessel, which has an infra-red measuring equipment at a certain distance above the tops of the fuel rods. The fuel element to be tested together with the test vessel and hood are immersed in a basin full of water, which displaces water by means of gas from the hood. The post-shutdown heat increases the temperature in the water space of the test vessel, which is stabilised at 100 0 C. In each defective fuel rod the water which has penetrated the defective fuel rod previously, or does so now, starts to boil. The steam rising in the fuel rod raises the temperature of the defective fuel rod compared to all the sound ones. The subsequent measurement easily determines this. Where one can expect interference with the measurement by appreciable amounts of gamma rays, the measuring equipment is removed from the path of radiation by mirror deflection in a suitably shaped measuring hood. (FW) [de

  20. Parallel processing of neutron transport in fuel assembly calculation

    International Nuclear Information System (INIS)

    Song, Jae Seung

    1992-02-01

    Group constants, which are used for reactor analyses by nodal method, are generated by fuel assembly calculations based on the neutron transport theory, since one or a quarter of the fuel assembly corresponds to a unit mesh in the current nodal calculation. The group constant calculation for a fuel assembly is performed through spectrum calculations, a two-dimensional fuel assembly calculation, and depletion calculations. The purpose of this study is to develop a parallel algorithm to be used in a parallel processor for the fuel assembly calculation and the depletion calculations of the group constant generation. A serial program, which solves the neutron integral transport equation using the transmission probability method and the linear depletion equation, was prepared and verified by a benchmark calculation. Small changes from the serial program was enough to parallelize the depletion calculation which has inherent parallel characteristics. In the fuel assembly calculation, however, efficient parallelization is not simple and easy because of the many coupling parameters in the calculation and data communications among CPU's. In this study, the group distribution method is introduced for the parallel processing of the fuel assembly calculation to minimize the data communications. The parallel processing was performed on Quadputer with 4 CPU's operating in NURAD Lab. at KAIST. Efficiencies of 54.3 % and 78.0 % were obtained in the fuel assembly calculation and depletion calculation, respectively, which lead to the overall speedup of about 2.5. As a result, it is concluded that the computing time consumed for the group constant generation can be easily reduced by parallel processing on the parallel computer with small size CPU's

  1. Drop size measurements and entrainment in APR1400 during LBLOCA reflood phase

    International Nuclear Information System (INIS)

    Lee, Eo Hwak

    2010-02-01

    A study has been performed to investigate droplet size in the nuclear reactor of APR1400 during LBLOCA reflood phase and to develop droplet entrainment and deposition models for SPACE (Safety and Performance CodE) which is a safety analysis tool for PWR being developed in Korea. A freezing technique for measuring the size of droplets was developed to obtain the droplet size distribution in horizontal annular flow in a pipe with a 37.1 mm diameter. Droplets are frozen by using an extremely low temperature nitrogen gas with liquid film extraction. They are then photographed with a microscope and a CCD camera and measured by means of an image process. The results are compared with various experimental data. The droplet sizes measured by the freezing technique are comparable with those measured by other methods at a high superficial air velocity (of 50 m/s). However, because of the film extraction problem, the droplet sizes measured at a low superficial air velocity of less than 40 m/s are higher than those measured by other methods. A present method suggested for predicting the Sauter mean diameter is based on the maximum droplet size correlation for the experimental data, with and without liquid film extraction. The average droplet size is remarkably smaller downstream of the liquid film extractor because large droplets from the liquid film are excluded. In order to understand and to predict a heat transfer between superheated steam and droplets properly during reflood phase of LBLOCA, it is very important to measure broken droplet sizes by spacer grids. A study, therefore, has been performed to investigate droplet size in rod bundles with spacer grids and to develop a spacer grid droplet breakup model for safety analysis codes. Experiments were conducted with liquid droplets (SMD of 300∼700 μm) and various spacer grids at superficial air velocity of 10 m/s and 20 m/s based on FLECHT SEASET. The test channel and the grids were heated to 150 .deg. C to prevent

  2. Drop size measurements and entrainment in APR1400 during LBLOCA reflood phase

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Eo Hwak

    2010-02-15

    A study has been performed to investigate droplet size in the nuclear reactor of APR1400 during LBLOCA reflood phase and to develop droplet entrainment and deposition models for SPACE (Safety and Performance CodE) which is a safety analysis tool for PWR being developed in Korea. A freezing technique for measuring the size of droplets was developed to obtain the droplet size distribution in horizontal annular flow in a pipe with a 37.1 mm diameter. Droplets are frozen by using an extremely low temperature nitrogen gas with liquid film extraction. They are then photographed with a microscope and a CCD camera and measured by means of an image process. The results are compared with various experimental data. The droplet sizes measured by the freezing technique are comparable with those measured by other methods at a high superficial air velocity (of 50 m/s). However, because of the film extraction problem, the droplet sizes measured at a low superficial air velocity of less than 40 m/s are higher than those measured by other methods. A present method suggested for predicting the Sauter mean diameter is based on the maximum droplet size correlation for the experimental data, with and without liquid film extraction. The average droplet size is remarkably smaller downstream of the liquid film extractor because large droplets from the liquid film are excluded. In order to understand and to predict a heat transfer between superheated steam and droplets properly during reflood phase of LBLOCA, it is very important to measure broken droplet sizes by spacer grids. A study, therefore, has been performed to investigate droplet size in rod bundles with spacer grids and to develop a spacer grid droplet breakup model for safety analysis codes. Experiments were conducted with liquid droplets (SMD of 300∼700 μm) and various spacer grids at superficial air velocity of 10 m/s and 20 m/s based on FLECHT SEASET. The test channel and the grids were heated to 150 .deg. C to prevent

  3. Rewetting and liquid entrainment during reflooding: state of the art

    International Nuclear Information System (INIS)

    Elias, E.; Yadigaroglu, G.

    1977-05-01

    Considerable interest has recently been generated in the problems of surface rewetting and the physics of liquid droplet entrainment due to their role in light water nuclear reactor safety. Published models of the rewetting process include simple one-dimensional solutions in two axial regions, one-dimensional solutions in three axial regions with or without precursory cooling, one- and two-dimensional numerical-difference techniques using temperature dependent heat transfer coefficients, and analytical two-dimensional solutions. The basic assumptions of these models and the numerical values assigned to the various parameters, as well as empirical rewetting correlations, are discussed. The various mechanisms for liquid droplet entrainment and analytical formulations of the critical gas velocity and of the droplet diameter at the onset of entrainment are reviewed

  4. Experimental investigation on the droplet entrainment from interfacial waves in air-water horizontal stratified flow

    International Nuclear Information System (INIS)

    Bae, Byeong Geon; Yun, Byong Jo; Kim, Kyoung Du

    2014-01-01

    It was mainly due to the fact that droplet entrainment affects the Peak Cladding Temperature (PCT) of the nuclear fuel rod in the Postulated accident conditions of NPP. Recently, droplet entrainment in the horizontally arranged primary piping system for the NPP is of interest because it affects directly the steam binding phenomena in the steam generators. Pan and Hanratty correlation is the only applicable one for the droplet entrainment rate model for horizontal flow. Moreover, there are no efforts for the model development on the basis of the droplet entrainment principal and physics phenomena. More recently, Korea Atomic Energy Research Institute (KAERI) proposed a new mechanistic droplet generation model applicable in the horizontal pipe for the SPACE code. However, constitutive relations in this new model require three model coefficients which have not yet been decided. The purpose of present work is determining three model coefficients by visualization experiment. For these model coefficients, the major physical parameters regarding the interfacial disturbance wave should be measured in this experiments. There are the wave slope, liquid fraction, wave hypotenuse length, wave velocity, wave frequency, and wavelength in the major physical parameters. The experiment was conducted at an air water horizontal rectangular channel with the PIV system. In this study, the experimental conditions were stratified-way flow during the droplet generation. Three coefficients were determined based on several data related to the interfacial wave. Additionally, we manufactured the parallel wire conductance probe to measure the fluctuating water level over time, and compared the wave height measured by the parallel wire conductance probe and image processing from images taken by high speed camera. Experimental investigation was performed for droplet entrainment from phase interface wave in an air-water stratified flow. In the experiments, we measured major physical parameters

  5. Holistic analysis of thermochemical processes by using solid biomass for fuel production in Germany; Ganzheitliche Analyse thermochemischer Verfahren bei der Nutzung fester Biomasse zur Kraftstoffproduktion in Deutschland

    Energy Technology Data Exchange (ETDEWEB)

    Henssler, Martin

    2015-04-28

    According to the German act ''Biokraftstoff-Nachhaltigkeitsverordnung'', biofuels must show a CO{sub 2eq}-reduction compared to the fossil reference fuel (83.8 g CO{sub 2eq}/MJ{sub fuel} /Richtlinie 98/70/EG/) of 35 % beginning with 2011. In new plants, which go into operation after the 31.12.2016 the CO{sub 2eq}-savings must be higher than 50 % in 2017 and higher than 60 % in 2018 /Biokraft-NachV/. The biofuels (methyl ester of rapeseed, bioethanol and biomethane) considered in this study do not meet these requirements for new plants. To comply with these rules new processes must be deployed. Alternative thermochemical generated fuels could be an option. The aim of this work is to evaluate through a technical, ecological and economic analysis (Well-to-Wheel) whether and under what conditions the thermochemical production of Fischer-Tropsch-diesel or -gasoline, hydrogen (H{sub 2}) and Substitute Natural Gas (SNG) complies with the targets. Four different processes are considered (fast pyrolysis and torrefaction with entrained flow gasifier, CHOREN Carbo-V {sup registered} -gasifier, Absorption Enhanced Reforming (AER-) gasifier). Beside residues such as winter wheat straw and residual forest wood, wood from short-rotation plantations is taken into account. The technical analysis showed that at present status (2010) two and in 2050 six plants can be operated energy-self-sufficient. The overall efficiency of the processes is in the range of 41.5 (Fischer-Tropsch-diesel or -gasoline) and 59.4 % (H{sub 2}). Furthermore, it was found that for 2010, all thermochemical produced fuels except the H{sub 2}-production from wood from short-rotation plantations in decentralised or central fast pyrolysis and in decentralised torrefactions with entrained flow gasifier keep the required CO{sub 2eq}-saving of 60 %. In 2050, all thermochemical produced fuels will reach these limits. The CO{sub 2eq}-saving is between 72 (H{sub 2}) and 95 % (Fischer

  6. Demonstration of pyrometallurgical processing for metal fuel and HLW

    International Nuclear Information System (INIS)

    Tadafumi, Koyama; Kensuke, Kinoshita; Takatoshi, Hizikata; Tadashi, Inoue; Ougier, M.; Rikard, Malmbeck; Glatz, J.P.; Lothar, Koch

    2001-01-01

    CRIEPI and JRC-ITU have started a joint study on pyrometallurgical processing to demonstrate the capability of this type of process for separating actinide elements from spent fuel and HLW. The equipment dedicated for this experiments has been developed and installed in JRC-ITU. The stainless steel box equipped with tele-manipulators is operated under pure Ar atmosphere, and prepared for later installation in a hot cell. Experiments on pyro-processing of un-irradiated U-Pu-Zr metal alloy fuel by molten salt electrorefining has been carried out. Recovery of U and Pu from this type alloy fuel was first demonstrated with using solid iron cathode and liquid Cd cathode, respectively. (author)

  7. Processing of carbon composite paper as electrode for fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Mathur, R.B.; Maheshwari, Priyanka H.; Dhami, T.L. [Carbon Technology Unit, National Physical Laboratory, New Delhi 110012 (India); Sharma, R.K.; Sharma, C.P. [Soft Polymeric Group, Division of Engineering Materials, National Physical Laboratory, New Delhi 110012 (India)

    2006-10-27

    The porous carbon electrode in a fuel cell not only acts as an electrolyte and a catalyst support, but also allows the diffusion of hydrogen fuel through its fine porosity and serves as a current-carrying conductor. A suitable carbon paper electrode is developed and possesses the characteristics of high porosity, permeability and strength along with low electrical resistivity so that it can be effectively used in proton-exchange membrane and phosphoric acid fuel cells. The electrode is prepared through a combination of two important techniques, viz., paper-making technology by first forming a porous chopped carbon fibre preform, and composite technology using a thermosetting resin matrix. The study reveals an interdependence of one parameter on another and how judicious choice of the processing conditions are necessary to achieve the desired characteristics. The current-voltage performance of the electrode in a unit fuel cell matches that of a commercially-available material. (author)

  8. Quality control in the fuel elements production process

    International Nuclear Information System (INIS)

    Katanic-Popovic, J.; Spasic, Z.; Djuricis, Lj.

    1977-01-01

    Recently great attention has been paid at the international level to the analysis of production processes and quality control of fuel and fuel elements with the aim to speed up activity of proposing and accepting standards and measurement methods. IAEA also devoted great interest to these problems appealing to more active participation of all users and producers fuel elements in a general effort to secure successful work of nuclear plants. For adequate and timely participation in future in the establishment and analysis of general requirements and documentation for the control of purchased or self produced fuel elements in out country it is necessary to be well informed and to follow this activity at the international level. (author)

  9. Process and apparatus for sealing nuclear reactor fuel

    International Nuclear Information System (INIS)

    Duncan, R.; Barna, R.P.

    1978-01-01

    A process and apparatus for simultaneously pressurizing a fuel rod having a plug in one end, welding a plug in the other end and sealing a gas pressurizing orifice therein in a single operation is described. A weld chamber is provided which accommodates one end of a seal rod having a plug fixed in the rod end by a friction fit. A mechanism pushes the fuel rod into the weld chamber which is then pressurized to force gas through a plug orifice into the fuel rod. During subsequent rotation of the rod, an electrode in the weld chamber forms a weld puddle which bridges the end plug-fuel rod interface and the plug orifice to thereby weld the plug in the rod and seal the plug orifice in a single operation. 6 claims, 3 figures

  10. Advanced Fuels and Combustion Processes for Propulsion

    Science.gov (United States)

    2010-09-01

    production from biomass steam reforming – Conduct a feasibility analysis of the proposed integrated process Energia Technologies - D. Nguyen & K. Parimi...strength foam material development by Ultramet – Combustion experiments performed U. Of Alabama – End-user input provided by Solar Turbines Major

  11. PHWR fuel fabrication with imported uranium - procedures and processes

    International Nuclear Information System (INIS)

    Rao, R.V.R.L.V.; Rameswara Rao, A.; Hemantha Rao, G.V.S.; Jayaraj, R.N.

    2010-01-01

    Following the 123 agreement and subsequent agreements with IAEA & NSG, Government of India has entered into bilateral agreements with different countries for nuclear trade. Department of Atomic Energy (DAE), Government of India, has entered into contract with few countries for supply of uranium material for use in the safeguarded PHWRs. Nuclear Fuel Complex (NFC), an industrial unit of DAE, established in the early seventies, is engaged in the production of Nuclear Fuel and Zircaloy items required for Nuclear Power Reactors operating in the country. NFC has placed one of its fuel fabrication facilities (NFC, Block-A, INE-) under safeguards. DAE has opted to procure uranium material in the form of ore concentrate and fuel pellets. Uranium ore concentrate was procured as per the ASTM specifications. Since no international standards are available for PHWR fuel pellets, Specifications have to be finalized based on the present fabrication and operating experience. The process steps have to be modified and fine tuned for handling the imported uranium material especially for ore concentrate. Different transportation methods are to be employed for transportation of uranium material to the facility. Cost of the uranium material imported and the recoveries at various stages of fuel fabrication have impact on the fuel pricing and in turn the unit energy costs. Similarly the operating procedures have to be modified for safeguards inspections by IAEA. NFC has successfully manufactured and supplied fuel bundles for the three 220 MWe safeguarded PHWRs. The paper describes various issues encountered while manufacturing fuel bundles with different types of nuclear material. (author)

  12. Crustal entrainment and pulsar glitches.

    Science.gov (United States)

    Chamel, N

    2013-01-04

    Large pulsar frequency glitches are generally interpreted as sudden transfers of angular momentum between the neutron superfluid permeating the inner crust and the rest of the star. Despite the absence of viscous drag, the neutron superfluid is strongly coupled to the crust due to nondissipative entrainment effects. These effects are shown to severely limit the maximum amount of angular momentum that can possibly be transferred during glitches. In particular, it is found that the glitches observed in the Vela pulsar require an additional reservoir of angular momentum.

  13. Study of the oxygen reduction reaction using Pt-Rare earths (La, Ce, Er) electrocatalysts for application of PEM fuel cells

    International Nuclear Information System (INIS)

    Gomes, Thiago Bueno

    2013-01-01

    The complexity of the oxygen reduction reaction (ORR) and its potential losses make it responsible for the most part of efficiency losses at the Fuel Cells. For this reaction the electrocatalyst witch is most appropriated and shows better performance is platinum, a noble metal that elevates the cost, raising barriers for Fuel Cells technology to enter the market. First this work focuses on reducing the amount of platinum used in the cathode, by being replaced by rare earths. The most common methods of synthesis involves a large amount of steps and this work proposed to prepare the electrocatalyst through a simpler way that would not take so many steps and time to be done. Using an ultrasound mixer the electrocatalyst was prepared mixing platinum supported on carbon black and the rare earths lanthanum, cerium and erbium oxides to be applied in a half-cell study of the ORR. The Koutecky-Levich plots shows that among the electrocatalysts prepared the Pt80Ce20/C had the catalytic activity close to the commercial BASF platinum on carbon black, suggesting that the reaction was taken by the 4-electron path. As found in some works in literature, among the rare earth used to study the ORR, cerium is the one witch shows the better performance because it is able to store and provide oxygen. This feature is of great interest for the ORR because this reaction is first order to the oxygen concentration. Results show that is possible to reduce the amount of platinum maintaining the same electrocatalyst activity. (author)

  14. Digital mock-up for the spent fuel disassembly processes

    International Nuclear Information System (INIS)

    Lee, J. Y.; Kim, S. H.; Song, T. G.; Kim, Y. H.; Hong, D. H.; Yoon, J. S.

    2000-12-01

    In this study, the graphical design system is developed and the digital mock-up is implemented for designing the spent fuel handling and disassembly processes. The system consists of a 3D graphical modeling system, a devices assembling system, and a motion simulation system. This system is used throughout the design stages from the conceptual design to the motion analysis. By using this system, all the process involved in the spent fuel handling and disassembly processes are analyzed and optimized. Also, this system is used in developing the on-line graphic simulator which synchronously simulates the motion of the equipment in a real time basis by connecting the device controllers with the graphic server through the TCP/IP network. This simulator can be effectively used for detecting the malfunctions of the process equipment which is remotely operated. Thus, the simulator enhances the reliability and safety of the spent fuel handling process by providing the remote monitoring function of the process. The graphical design system and the digital mock-up system can be effectively used for designing the process equipment, as well as the optimized process and maintenance process. And the on-line graphic simulator can be an alternative of the conventional process monitoring system which is a hardware based system

  15. Process for production of liquid fuels

    Energy Technology Data Exchange (ETDEWEB)

    1947-03-14

    The process comprises continually passing a current of carbonaceous material, finely divided in a vertical zone of reaction, finely divided carbonaceous material raised to a fluidized state dispersed in gas flowing from the bottom to the top carrying into the zone of reaction an oxidizing gas in sufficient quantity to supply the heat for combustion by burning part of the carbonaceous material withdrawing from the zone of reaction the products of the combustible fluids, withdrawing from the zone the solid carbonaceous products of the reaction and reacting a part of the lesser products left in a second zone of reaction by means of steam to produce oxides of carbon and hydrogen.

  16. Fuel sparing: Control of industrial furnaces using process gas as supplemental fuel

    International Nuclear Information System (INIS)

    Boisvert, Patrick G.; Runstedtler, Allan

    2014-01-01

    Combustible gases from industrial processes can be used to spare purchased fuels such as natural gas and avoid wasteful flaring of the process gases. One of the challenges of incorporating these gases into other furnaces is their intermittent availability. In order to incorporate the gases into a continuously operating furnace, the furnace control system must be carefully designed so that the payload is not affected by the changing fuel. This paper presents a transient computational fluid dynamics (CFD) model of an industrial furnace that supplements natural gas with carbon monoxide during furnace operation. A realistic control system of the furnace is simulated as part of the CFD calculation. The time dependent changes in fuels and air injection on the furnace operation is observed. It is found that there is a trade-off between over-controlling the furnace, which results in too sensitive a response to normal flow oscillations, and under-controlling, which results in a lagged response to the fuel change. - Highlights: •Intermittently available process gases used in a continuously operating furnace. •Study shows a trade-off between over-controlling and under-controlling the furnace. •Over-controlling: response too sensitive to normal flow oscillations. •Under-controlling: lagged response to changing fuel composition. •Normal flow oscillations in furnace would not be apparent in steady-state model

  17. Entrainer selection for the synthesis of fatty acid esters by entrainer-based reactive distillation

    NARCIS (Netherlands)

    Jong, de M.C.; Zondervan, E.; Dimian, A.C.; Haan, de A.B.

    2010-01-01

    In this research it is demonstrated that, due to the similarities between Entrainer-based Reactive Distillation and azeotropic distillation, the same selection rules can be applied to select a suitable entrainer. From a list of suitable entrainers for the azeotropic distillation of isopropanol and

  18. Simulation study of light transport in laser-processed LYSO:Ce detectors with single-side readout.

    Science.gov (United States)

    Bläckberg, L; El Fakhri, G; Sabet, H

    2017-10-19

    A tightly focused pulsed laser beam can locally modify the crystal structure inside the bulk of a scintillator. The result is incorporation of so-called optical barriers with a refractive index different from that of the crystal bulk, that can be used to redirect the scintillation light and control the light spread in the detector. We here systematically study the scintillation light transport in detectors fabricated using the laser induced optical barrier technique, and objectively compare their potential performance characteristics with those of the two mainstream detector types: monolithic and mechanically pixelated arrays. Among countless optical barrier patterns, we explore barriers arranged in a pixel-like pattern extending all-the-way or half-way through a 20 mm thick LYSO:Ce crystal. We analyze the performance of the detectors coupled to MPPC arrays, in terms of light response functions, flood maps, line profiles, and light collection efficiency. Our results show that laser-processed detectors with both barrier patterns constitute a new detector category with a behavior between that of the two standard detector types. Results show that when the barrier-crystal interface is smooth, no DOI information can be obtained regardless of barrier refractive index (RI). However, with a rough barrier-crystal interface we can extract multiple levels of DOI. Lower barrier RI results in larger light confinement, leading to better transverse resolution. Furthermore we see that the laser-processed crystals have the potential to increase the light collection efficiency, which could lead to improved energy resolution and potentially better timing resolution due to higher signals. For a laser-processed detector with smooth barrier-crystal interfaces the light collection efficiency is simulated to  >42%, and for rough interfaces  >73%. The corresponding numbers for a monolithic crystal is 39% with polished surfaces, and 71% with rough surfaces, and for a mechanically

  19. Process for producing a fuel suitable for degassing from refuse

    Energy Technology Data Exchange (ETDEWEB)

    Sulzberger, J

    1975-11-20

    Utilization of the heat energy of refuse in waste incineration plants is time-consuming and expensive due to high investment and operation costs. The inventor recommends to process the refuse to a sterile, handy and storable fuel. For this propose the refuse should be crushed, kneaded and pressed. The briquettes produced in this way should be dried.

  20. Electrochemical performance of Ni0.8Cu0.2/Ce0.8Gd0.2O1.9 cermet anodes with functionally graded structures for intermediate-temperature solid oxide fuel cell fueled with syngas

    Science.gov (United States)

    Miyake, Michihiro; Iwami, Makoto; Takeuchi, Mizue; Nishimoto, Shunsuke; Kameshima, Yoshikazu

    2018-06-01

    The electrochemical performance of layered Ni0.8Cu0.2/Ce0.8Gd0.2O1.9 (GDC) cermet anodes is investigated for intermediate-temperature solid oxide fuel cells (IT-SOFCs) at 600 °C using humidified (3% H2O) model syngas with a molar ratio of H2/CO = 3/2 as the fuel. From the results obtained, the electrochemical performance of the functionally graded multi-layered anodes is found to be superior to the mono-layered anodes. The test cell with a bi-layered anode consisting of 100 mass% Ni0.8Cu0.2/0 mass% GDC (10M/0E) and 70 mass% Ni0.8Cu0.2/30 mass% GDC (7M/3E) exhibits high power density. The test cell with a tri-layered anode consisting of 10M/0E, 7M/3E, and 50 mass% Ni0.8Cu0.2/50 mass% GDC (5M/5E) exhibits an even higher power density, suggesting that 10M/0E and 5M/5E layers contribute to the current collecting part and active part, respectively.

  1. Handbook on process and chemistry of nuclear fuel reprocessing. 3rd edition

    International Nuclear Information System (INIS)

    2015-03-01

    The fundamental data on spent nuclear fuel reprocessing and related chemistry was collected and summarized as a new edition of 'Handbook on Process and Chemistry of Nuclear Fuel Reprocessing'. The purpose of this handbook is contribution to development of the fuel reprocessing and fuel cycle technology for uranium fuel and mixed oxide fuel utilization. Contents in this book was discussed and reviewed by specialists of science and technology on fuel reprocessing in Japan. (author)

  2. Process for gasifying fuels with the recovery of rich gases

    Energy Technology Data Exchange (ETDEWEB)

    Jahns, F

    1921-04-10

    A process for gasifying fuels with recovery of water-free, rich-in-tar gases in a ring-gas-producer characterized by hot-gas-stream arising from the gasification bed of a fresh chamber in the known way is divided. One part is conducted through an old chamber, the other part is led first during the drying through the fresh fuel and with the received water-vapor also through the old chamber and then during the carbonization with the carbonization products is led to the carbonization-gas conduit.

  3. Structural analysis of advanced spent fuel conditioning process

    International Nuclear Information System (INIS)

    Gu, J. H.; Jung, W. M.; Jo, I. J.; Gug, D. H.; Yoo, K. S.

    2003-01-01

    An advanced spent fuel conditioning process (ACP) is developing for the safe and effective management of spent fuels which arising from the domestic nuclear power plants. And its demonstration facility is under design. This facility will be prepared by modifying IMEF's reserve hot cell facility which reserved for future usage by considering the characteristics of ACP. This study presents a basic structural architecture design and analysis results of ACP hot cell including modification of the IMEF. The results of this study will be used for the detail design of ACP demonstration facility, and utilized as basic data for the licensing of the ACP facility

  4. Dustless fabrication process for minor actinide bearing blankets: first applications to (Ce,Gd)O2 and (U,Am)O2

    International Nuclear Information System (INIS)

    Caisso, M.; Lebreton, F.; Horlait, D.; Delahaye, T.; Picart, S.; Gauthe, A.; Renard, C.; Roussel, P.; Martin, P.; Neuville, D.R.; Ayral, A.

    2014-01-01

    Minor actinides (MA) are generated in UOX and MOX fuels during irradiation in nuclear reactors. In the framework of their recycling, transmutation of americium in fast neutron reactors through MABB (Minor Actinide-Bearing Blanket) irradiation represents a major research focus. However, MABB fabrication requires special attention due to the high radiotoxicity of MA. Currently, the fabrication of these mixed-oxide pellets follows a powder metallurgy route which generates fine particles. Dustless processes which can avoid the use of such fine, thus highly contaminant, powder in the fabrication line are recommended. In this aim, the development of a spherule route called the calcined resin microsphere pelletizing (CRMP) process has been initiated. The general approach consists of elaborating micrometric spherical mixed-oxide precursors through an adaptation of the weak acid resin (WAR) process, and their compaction into pellets before sintering. The spherule synthesis is based on the fixation of americium and uranium ions into the beads composed of an ion exchange resin, and their mineralization leading to the formation of oxide microspheres. Our study is a first step in the elaboration of mixed-oxide pellets by the CRMP process, using cerium and gadolinium as lanthanide surrogates for uranium and americium, respectively. In a first part, the resin loading with a selected Ce/Gd ratio of 80/20 is described, with the use of actinide nitrates dissolved in aqueous solution. In a second part, characterizations by TGA (thermogravimetric analysis), HT-XRD (high-temperature X-ray diffraction), HT-Raman spectroscopy and HT-XAS (high temperature X-ray absorption spectroscopy) of the loaded resin were performed to study the departure of carbon from the initial structure and the oxide formation. Key temperatures were identified, corresponding to the important steps of the formation of a gadolinium doped ceria solid solution. The organic matter departure happens around 400 K and

  5. Method For Processing Spent (Trn,Zr)N Fuel

    Science.gov (United States)

    Miller, William E.; Richmann, Michael K.

    2004-07-27

    A new process for recycling spent nuclear fuels, in particular, mixed nitrides of transuranic elements and zirconium. The process consists of two electrorefiner cells in series configuration. A transuranic element such as plutonium is reduced at the cathode in the first cell, zirconium at the cathode in the second cell, and nitrogen-15 is released and captured for reuse to make transuranic and zirconium nitrides.

  6. Adding the s-Process Element Cerium to the APOGEE Survey: Identification and Characterization of Ce II Lines in the H-band Spectral Window

    Science.gov (United States)

    Cunha, Katia; Smith, Verne V.; Hasselquist, Sten; Souto, Diogo; Shetrone, Matthew D.; Allende Prieto, Carlos; Bizyaev, Dmitry; Frinchaboy, Peter; García-Hernández, D. Anibal; Holtzman, Jon; Johnson, Jennifer A.; Jőnsson, Henrik; Majewski, Steven R.; Mészáros, Szabolcs; Nidever, David; Pinsonneault, Mark; Schiavon, Ricardo P.; Sobeck, Jennifer; Skrutskie, Michael F.; Zamora, Olga; Zasowski, Gail; Fernández-Trincado, J. G.

    2017-08-01

    Nine Ce II lines have been identified and characterized within the spectral window observed by the Apache Point Observatory Galactic Evolution Experiment (APOGEE) survey (between λ1.51 and 1.69 μm). At solar metallicities, cerium is an element that is produced predominantly as a result of the slow capture of neutrons (the s-process) during asymptotic giant branch stellar evolution. The Ce II lines were identified using a combination of a high-resolution (R=λ /δ λ ={{100,000}}) Fourier Transform Spectrometer (FTS) spectrum of α Boo and an APOGEE spectrum (R = 22,400) of a metal-poor, but s-process enriched, red giant (2M16011638-1201525). Laboratory oscillator strengths are not available for these lines. Astrophysical gf-values were derived using α Boo as a standard star, with the absolute cerium abundance in α Boo set by using optical Ce II lines that have precise published laboratory gf-values. The near-infrared Ce II lines identified here are also analyzed, as consistency checks, in a small number of bright red giants using archival FTS spectra, as well as a small sample of APOGEE red giants, including two members of the open cluster NGC 6819, two field stars, and seven metal-poor N- and Al-rich stars. The conclusion is that this set of Ce II lines can be detected and analyzed in a large fraction of the APOGEE red giant sample and will be useful for probing chemical evolution of the s-process products in various populations of the Milky Way.

  7. Fuel production from coal by the Mobil Oil process using nuclear high-temperature process heat

    International Nuclear Information System (INIS)

    Hoffmann, G.

    1982-01-01

    Two processes for the production of liquid hydrocarbons are presented: Direct conversion of coal into fuel (coal hydrogenation) and indirect conversion of coal into fuel (syngas production, methanol synthesis, Mobil Oil process). Both processes have several variants in which nuclear process heat may be used; in most cases, the nuclear heat is introduced in the gas production stage. The following gas production processes are compared: LURGI coal gasification process; steam reformer methanation, with and without coal hydrogasification and steam gasification of coal. (orig./EF) [de

  8. Broadening of cloud droplet spectra through turbulent entrainment and eddy hopping

    Science.gov (United States)

    Abade, Gustavo; Grabowski, Wojciech; Pawlowska, Hanna

    2017-11-01

    This work discusses the effect of cloud turbulence and turbulent entrainment on the evolution of the cloud droplet-size spectrum. We simulate an ensemble of idealized turbulent cloud parcels that are subject to entrainment events, modeled as a random Poisson process. Entrainment events, subsequent turbulent mixing inside the parcel, supersaturation fluctuations, and the resulting stochastic droplet growth by condensation are simulated using a Monte Carlo scheme. Quantities characterizing the turbulence intensity, entrainment rate and the mean fraction of environmental air entrained in an event are specified as external parameters. Cloud microphysics is described by applying Lagrangian particles, the so-called superdroplets. They are either unactivated cloud condensation nuclei (CCN) or cloud droplets that form from activated CCN. The model accounts for the transport of environmental CCN into the cloud by the entraining eddies at the cloud edge. Turbulent mixing of the entrained dry air with cloudy air is described using a linear model. We show that turbulence plays an important role in aiding entrained CCN to activate, providing a source of small cloud droplets and thus broadening the droplet size distribution. Further simulation results will be reported at the meeting.

  9. Fuel processing for PEM fuel cells: transport and kinetic issues of system design

    Science.gov (United States)

    Zalc, J. M.; Löffler, D. G.

    In light of the distribution and storage issues associated with hydrogen, efficient on-board fuel processing will be a significant factor in the implementation of PEM fuel cells for automotive applications. Here, we apply basic chemical engineering principles to gain insight into the factors that limit performance in each component of a fuel processor. A system consisting of a plate reactor steam reformer, water-gas shift unit, and preferential oxidation reactor is used as a case study. It is found that for a steam reformer based on catalyst-coated foils, mass transfer from the bulk gas to the catalyst surface is the limiting process. The water-gas shift reactor is expected to be the largest component of the fuel processor and is limited by intrinsic catalyst activity, while a successful preferential oxidation unit depends on strict temperature control in order to minimize parasitic hydrogen oxidation. This stepwise approach of sequentially eliminating rate-limiting processes can be used to identify possible means of performance enhancement in a broad range of applications.

  10. Stable, easily sintered BaCe0.5Zr0.3Y0.16Zn0.04O3-δ electrolyte-based proton-conducting solid oxide fuel cells by gel-casting and suspension spray

    International Nuclear Information System (INIS)

    Lin Bin; Dong Yingchao; Wang Songlin; Fang Daru; Ding Hanping; Zhang Xiaozhen; Liu Xingqin; Meng Guangyao

    2009-01-01

    Protonic ceramic membrane fuel cells (PCMFCs) based on oxide proton conductors exhibit more advantages than traditional solid oxide fuel cells (SOFCs) based on oxygen-ion conducting electrolytes, such as low activation energy and high energy efficiency. In order to develop a simple and cost-effective route to fabricate PCMFCs with SrCo 0.9 Sb 0.1 O 3-δ (SCS) cubic perovskite cathode, a dense BaCe 0.5 Zr 0.3 Y 0.16 Zn 0.04 O 3-δ (BCZYZn) electrolyte was fabricated in situ metal oxide on a porous anode support by gel-casting and suspension spray, which is cost-effective, easy to realize, and suitable for mass-production. The key part of this process is to directly spray well-mixed suspension of BaCO 3 , CeO 2 , ZrO 2 , Y 2 O 3 and ZnO instead of pre-synthesized BCZYZn ceramic powder on the anode substrate. With SCS cubic perovskite cathode synthesized by gel-casting on the bi-layer, single cells were assembled and tested with H 2 as fuel and the static air as oxidant. An open-circuit potential of 0.987 V, a maximum power density of 364 mW cm -2 , and a low polarization resistance of the electrodes of 0.07 Ω cm 2 was achieved at 700 deg. C.

  11. Solvent extraction process development for high plutonium fuel cycles

    Energy Technology Data Exchange (ETDEWEB)

    Anil Kumar, R; Selvaraj, P G; Natarajan, R; Raman, V R [Reprocessing Group, Indira Gandhi Centre for Atomic Research, Kalpakkam (India)

    1994-06-01

    The purification of high plutonium bearing irradiated fuels using 30% TBP in dodecane diluent requires precise determination of concentration profiles during steady state, transient and process upset conditions. Mathematical models have been developed and a computer code is in use for determining Pu-U concentration profiles in a solvent extraction equipment in a typical reprocessing plant. The process parameters have been optimised for recovery of U and Pu and decontamination from the fission products. This computer code is used to analyse the extraction flow sheets of fuels of two typical Pu-U compositions encountered in Indian fast breeder programme. The analysis include the effect of uncertainty in equilibrium condition prediction by the model and the variation of flows of streams during plant operation. The studies highlight the margin available to avoid second organic phase formation and adjustments required in the process flowsheet. (author). 7 refs., 7 figs., 2 tabs.

  12. Process Investigation for Conversion of MSW into Liquid Fuel

    International Nuclear Information System (INIS)

    Javed, M.T.; Jafri, U.A.; Chugtai, I.R.

    2010-01-01

    An investigation was conducted on pyrolysis technology to convert the municipal solid waste into liquid fuel. The investigation includes the development of the experimental setup for this process and its future prospects in Pakistan. A pyrolysis process is under consideration for many years for the production of synthetic fuel oils from organic solid waste. The system comprises of pyrolysis reactor, condenser for condensable gas, gas holder (for non- condensable gas). The feedstock used in the pyrolysis reactor is the municipal solid waste (includes kitchen waste, papers etc) in fine mesh size i.e. 2.5 - 3.0 mm. The residue obtained were mainly tar (pyrolytic oil), pyrogas (non - condensable gases) and ash, which shows that process has a potential for the treatment of the municipal solid waste and is a good technology for resource recover. (author)

  13. Used nuclear fuel separations process simulation and testing

    International Nuclear Information System (INIS)

    Pereira, C.; Krebs, J.F.; Copple, J.M.; Frey, K.E.; Maggos, L.E.; Figueroa, J.; Willit, J.L.; Papadias, D.D.

    2013-01-01

    Recent efforts in separations process simulation at Argonne have expanded from the traditional focus on solvent extraction flowsheet design in order to capture process dynamics and to simulate other components, processing and systems of a used nuclear fuel reprocessing plant. For example, the Argonne Model for Universal Solvent Extraction (AMUSE) code has been enhanced to make it both more portable and more readily extensible. Moving away from a spreadsheet environment makes the addition of new species and processes simpler for the expert user, which should enable more rapid implementation of chemical models that simulate evolving processes. The dyAMUSE (dynamic AMUSE) version allows the simulation of transient behavior across an extractor. Electrochemical separations have now been modeled using spreadsheet codes that simulate the electrochemical recycle of fast reactor fuel. The user can follow the evolution of the salt, products, and waste compositions in the electro-refiner, cathode processors, and drawdown as a function of fuel batches treated. To further expand capabilities in integrating multiple unit operations, a platform for linking mathematical models representing the different operations that comprise a reprocessing facility was adapted to enable systems-level analysis and optimization of facility functions. (authors)

  14. Used nuclear fuel separations process simulation and testing

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, C.; Krebs, J.F.; Copple, J.M.; Frey, K.E.; Maggos, L.E.; Figueroa, J.; Willit, J.L.; Papadias, D.D. [Argonne National Laboratory: 9700 South Cass Avenue, Argonne, IL 60439 (United States)

    2013-07-01

    Recent efforts in separations process simulation at Argonne have expanded from the traditional focus on solvent extraction flowsheet design in order to capture process dynamics and to simulate other components, processing and systems of a used nuclear fuel reprocessing plant. For example, the Argonne Model for Universal Solvent Extraction (AMUSE) code has been enhanced to make it both more portable and more readily extensible. Moving away from a spreadsheet environment makes the addition of new species and processes simpler for the expert user, which should enable more rapid implementation of chemical models that simulate evolving processes. The dyAMUSE (dynamic AMUSE) version allows the simulation of transient behavior across an extractor. Electrochemical separations have now been modeled using spreadsheet codes that simulate the electrochemical recycle of fast reactor fuel. The user can follow the evolution of the salt, products, and waste compositions in the electro-refiner, cathode processors, and drawdown as a function of fuel batches treated. To further expand capabilities in integrating multiple unit operations, a platform for linking mathematical models representing the different operations that comprise a reprocessing facility was adapted to enable systems-level analysis and optimization of facility functions. (authors)

  15. Two-photon excitation processes to near-ultraviolet states in Ce3+:CaF2

    International Nuclear Information System (INIS)

    Hamilton, D.S.

    1982-11-01

    The two-photon transition to the lowest Ce 3+ 5d state in Ce 3+ :CaF 2 has been investigated. At liquid helium temperatures, a no-phonon resonance line is observed and is accompanied by a vibrational sideband. The peak cross section for this transition is of order 1 x 10 -53 cm 4 s indicating strong parity mixing for the 5d levels. The no-phonon line shows a polarization anisotropy consistent with a tetragonal Ce 3+ site of C 4 /sub V/ symmetry. The phonon side band shows a different anisotropy than the no-phonon line and its polarization characteristics are a function of phonon frequency and temperature

  16. Sequential Strategy Of Experimental Design I: Optimization Of Extractive Distillation Process Of Ethanol-water Using [bmim][n(cn)(2)] As Entrainer

    OpenAIRE

    Jaimes Figueroa; Jaiver Efren; Rodrigues; Maria Isabel; Wolf Maciel; Maria Regina

    2016-01-01

    Nowadays, one of the methods available to obtain the anhydrous ethanol is the extractive distillation process, which presents great potential depending on the solvent used. It is imperative that the solvent promotes dehydration, but low cost, the low energy consumption, and low waste generation and emissions must be taken into account. Within this context, there is high demand for new efficient solvents for extractive distillation of ethanol-water mixture, so, the ionic liquids (ILs) have som...

  17. Concerning permission of change in nuclear fuel processing business of Japan Nuclear Fuel Co. , Ltd

    Energy Technology Data Exchange (ETDEWEB)

    1988-12-01

    In response to an inquiry on the title issue received on Jun. 17, 1988, the Nuclear Safety Commission made a study and submitted the findings to the Prime Minister on Jul. 21, 1988. The study was intended to determine the conformity of the permission to the applicable criteria specified in laws relating to control of nuclear material, nuclear fuel and nuclear reactor. The proposed modification plan included changes in the facilities in the No.1 processing building and changes in processing methods which were required to perform processing of blanket fuel assemblies for fast breeder reactor. It also included changes in the facilities in the No.2 building which were required to improve the processes. The safety study covered the anti-earthquake performance, fire/explosion prevention, criticality control, containment performance, radioactive waste disposal, and other major safety issues. Other investigations included exposure dose evaluation and accident analysis. Study results were examined on the basis of the Basic Guidelines for Nuclear Fuel Facilities Safety Review and the Uranium Processing Safety Review Guidelines. It was concluded that the modifications would not have adverse effect on the safety of the facilities. (Nogami, K.).

  18. Concerning permission of change in nuclear fuel processing business of Japan Nuclear Fuel Co., Ltd

    International Nuclear Information System (INIS)

    1988-01-01

    In response to an inquiry on the title issue received on Jun. 17, 1988, the Nuclear Safety Commission made a study and submitted the findings to the Prime Minister on Jul. 21, 1988. The study was intended to determine the conformity of the permission to the applicable criteria specified in laws relating to control of nuclear material, nuclear fuel and nuclear reactor. The proposed modification plan included changes in the facilities in the No.1 processing building and changes in processing methods which were required to perform processing of blanket fuel assemblies for fast breeder reactor. It also included changes in the facilities in the No.2 building which were required to improve the processes. The safety study covered the anti-earthquake performance, fire/explosion prevention, criticality control, containment performance, radioactive waste disposal, and other major safety issues. Other investigations included exposure dose evaluation and accident analysis. Study results were examined on the basis of the Basic Guidelines for Nuclear Fuel Facilities Safety Review and the Uranium Processing Safety Review Guidelines. It was concluded that the modifications would not have adverse effect on the safety of the facilities. (Nogami, K.)

  19. Entrainment at a sediment concentration interface in turbulent channel flow

    Science.gov (United States)

    Salinas, Jorge; Shringarpure, Mrugesh; Cantero, Mariano; Balachandar, S.

    2016-11-01

    In this work we address the role of turbulence on entrainment at a sediment concentration interface. This process can be conceived as the entrainment of sediment-free fluid into the bottom sediment-laden flow, or alternatively, as the entrainment of sediment into the top sediment-free flow. We have performed direct numerical simulations for fixed Reynolds and Schmidt numbers while varying the values of Richardson number and particle settling velocity. The analysis performed shows that the ability of the flow to pick up a given sediment size decreases with the distance from the bottom, and thus only fine enough sediment particles are entrained across the sediment concentration interface. For these cases, the concentration profiles evolve to a final steady state in good agreement with the well-known Rouse profile. The approach towards the Rouse profile happens through a transient self-similar state. Detailed analysis of the three dimensional structure of the sediment concentration interface shows the mechanisms by which sediment particles are lifted up by tongues of sediment-laden fluid with positive correlation between vertical velocity and sediment concentration. Finally, the mixing ability of the flow is addressed by monitoring the center of mass of the sediment-laden layer. With the support of ExxonMobil, NSF, ANPCyT, CONICET.

  20. Thermodynamic stability studies of Ce-Sb compounds with Fe

    Science.gov (United States)

    Xie, Yi; Zhang, Jinsuo; Benson, Michael T.; Mariani, Robert D.

    2018-02-01

    Lanthanide fission products can migrate to the fuel periphery and react with cladding, causing fuel-cladding chemical interaction (FCCI). Adding a fuel additive dopant, such as Sb, can bind lanthanide, such as Ce, into metallic compounds and thus prevent migration. The present study focuses on the thermodynamic stability of Ce-Sb compounds when in contact with the major cladding constituent Fe by conducting diffusion couple tests. Ce-Sb compounds have shown high thermodynamic stability as they did not react with Fe. When Fe-Sb compounds contacted with Ce, Sb was separated out of Fe-Sb compounds and formed the more stable Ce-Sb compounds.

  1. Optimization Of Process Parameters For The Production Of Bio diesel From Waste Cooking Oil In The Presence Of Bifunctional γ-Al2O3-CeO2 Supported Catalysts

    International Nuclear Information System (INIS)

    Anita Ramli; Muhammad Farooq

    2015-01-01

    Huge quantities of waste cooking oils are produced all over the world every day, especially in the developed countries with 0.5 million ton per year waste cooking oil are being generated in Malaysia alone. Such large amount of waste cooking oil production can create disposal problems and contamination to water and land resources if not disposed properly. The use of waste cooking oil as feedstock for bio diesel production will not only avoid the competition of the same oil resources for food and fuel but will also overcome the waste cooking oil disposal problems. However, waste cooking oil has high acid value, thus would require the oil to undergo esterification with an acid catalyst prior to transesterification with a base catalyst. Therefore, in this study, bifunctional catalyst supports were developed for one-step esterification-transesterification of waste cooking oil by varying the CeO 2 loading on γ-Al 2 O 3 . The bifunctional supports were then impregnated with 5 wt % Mo and characterized using N 2 adsorption-desorption isotherm to determine the surface area of the catalysts while temperature programmed desorption with NH 3 and CO 2 as adsorbents were used to determine the acidity and basicity of the catalysts. Results show that the γ-Al 2 O 3 -CeO 2 supported Mo catalysts are active for the one-step esterification-transesterification of waste cooking oil to produce bio diesel with the Mo/ γ-Al 2 O 3 -20 wt% CeO 2 as the most active catalyst. Optimization of process parameters for the production of bio diesel from waste cooking oil in the presence of this catalyst show that 81.1 % bio diesel yield was produced at 110 degree Celsius with catalyst loading of 7 wt %, agitation speed of 600 rpm, methanol to oil ratio of 30:1 and reaction period of 270 minutes. (author)

  2. Pyrometallurgical processing of Integral Fast Reactor metal fuels

    International Nuclear Information System (INIS)

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

    1991-01-01

    The pyrometallurgical process for recycling spent metal fuels from the Integral Fast Reactor is now in an advanced state of development. This process involves electrorefining spent fuel with a cadmium anode, solid and liquid cathodes, and a molten salt electrolyte (LiCl-KCl) at 500 degrees C. The initial process feasibility and flowsheet verification studies have been conducted in a laboratory-scale electrorefiner. Based on these studies, a dual cathode approach has been adopted, where uranium is recovered on a solid cathode mandrel and uranium-plutonium is recovered in a liquid cadmium cathode. Consolidation and purification (salt and cadmium removal) of uranium and uranium-plutonium products from the electrorefiner have been successful. The process is being developed with the aid of an engineering-scale electrorefiner, which has been successfully operated for more than three years. In this electrorefiner, uranium has been electrotransported from the cadmium anode to a solid cathode in 10 kg quantities. Also, anodic dissolution of 10 kg batches of chopped, simulated fuel (U--10% Zr) has been demonstrated. Development of the liquid cadmium cathode for recovering uranium-plutonium is under way

  3. Towards Extrusion of Ionomers to Process Fuel Cell Membranes

    Directory of Open Access Journals (Sweden)

    Jean-Yves Sanchez

    2011-07-01

    Full Text Available While Proton Exchange Membrane Fuel Cell (PEMFC membranes are currently prepared by film casting, this paper demonstrates the feasibility of extrusion, a solvent-free alternative process. Thanks to water-soluble process-aid plasticizers, duly selected, it was possible to extrude acidic and alkaline polysulfone ionomers. Additionally, the feasibility to extrude composites was demonstrated. The impact of the plasticizers on the melt viscosity was investigated. Following the extrusion, the plasticizers were fully removed in water. The extrusion was found to impact neither on the ionomer chains, nor on the performances of the membrane. This environmentally friendly process was successfully validated for a variety of high performance ionomers.

  4. Modular, High-Volume Fuel Cell Leak-Test Suite and Process

    Energy Technology Data Exchange (ETDEWEB)

    Ru Chen; Ian Kaye

    2012-03-12

    Fuel cell stacks are typically hand-assembled and tested. As a result the manufacturing process is labor-intensive and time-consuming. The fluid leakage in fuel cell stacks may reduce fuel cell performance, damage fuel cell stack, or even cause fire and become a safety hazard. Leak check is a critical step in the fuel cell stack manufacturing. The fuel cell industry is in need of fuel cell leak-test processes and equipment that is automatic, robust, and high throughput. The equipment should reduce fuel cell manufacturing cost.

  5. Sintering Studies of Ga-Doped CeO2 (Ga-Doped PuO2 Surrogate) for Mixed Oxide Nuclear Fuel

    International Nuclear Information System (INIS)

    Haertling, C.; Huling, J.; Park, Y.S.

    1999-01-01

    Sintering studies of CeO 2 and CeO 2 + 2 wt. % Ga 2 O 3 were completed. Firing temperatures studied were 1250-1650 C with 2 to 4 hour firing soak times in air. Powders fabricated by three methods (as-received, attrition-mill and nitrite-derived) were studied. Attrition-milled CeO 2 improved densities as compared with as-received CeO 2 . Attrition-milled CeO 2 with 2 wt.% Ga 2 O 3 showed decreased densities with increasing temperatures. As-received CeO 2 with 2 wt.% Ga 2 O 3 showed a opposite trend, increasing in density with increased firing temperature. Two pellet preparation methods were studied, a one-step-press method and a two-step-press method. The two-step-press method showed greater densities at lower firing temperatures and times as compared with the one-step-press method, however for CeO 2 + 2 wt.% Ga 2 O 3 , the two methods gave equivalent results at 1650 C, 6 hr. firing conditions

  6. Radiation Monitoring System in Advanced Spent Fuel Conditioning Process Facility

    Energy Technology Data Exchange (ETDEWEB)

    You, Gil Sung; Kook, D. H.; Choung, W. M.; Ku, J. H.; Cho, I. J.; You, G. S.; Kwon, K. C.; Lee, W. K.; Lee, E. P

    2006-09-15

    The Advanced spent fuel Conditioning Process is under development for effective management of spent fuel by converting UO{sub 2} into U-metal. For demonstration of this process, {alpha}-{gamma} type new hot cell was built in the IMEF basement . To secure against radiation hazard, this facility needs radiation monitoring system which will observe the entire operating area before the hot cell and service area at back of it. This system consists of 7 parts; Area Monitor for {gamma}-ray, Room Air Monitor for particulate and iodine in both area, Hot cell Monitor for hot cell inside high radiation and rear door interlock, Duct Monitor for particulate of outlet ventilation, Iodine Monitor for iodine of outlet duct, CCTV for watching workers and material movement, Server for management of whole monitoring system. After installation and test of this, radiation monitoring system will be expected to assist the successful ACP demonstration.

  7. Radiation Monitoring System in Advanced Spent Fuel Conditioning Process Facility

    International Nuclear Information System (INIS)

    You, Gil Sung; Kook, D. H.; Choung, W. M.; Ku, J. H.; Cho, I. J.; You, G. S.; Kwon, K. C.; Lee, W. K.; Lee, E. P.

    2006-09-01

    The Advanced spent fuel Conditioning Process is under development for effective management of spent fuel by converting UO 2 into U-metal. For demonstration of this process, α-γ type new hot cell was built in the IMEF basement . To secure against radiation hazard, this facility needs radiation monitoring system which will observe the entire operating area before the hot cell and service area at back of it. This system consists of 7 parts; Area Monitor for γ-ray, Room Air Monitor for particulate and iodine in both area, Hot cell Monitor for hot cell inside high radiation and rear door interlock, Duct Monitor for particulate of outlet ventilation, Iodine Monitor for iodine of outlet duct, CCTV for watching workers and material movement, Server for management of whole monitoring system. After installation and test of this, radiation monitoring system will be expected to assist the successful ACP demonstration

  8. Process control of an HTGR fuel reprocessing cold pilot plant

    International Nuclear Information System (INIS)

    Rode, J.S.

    1976-10-01

    Development of engineering-scale systems for a large-scale HTGR fuel reprocessing demonstration facility is currently underway in a cold pilot plant. These systems include two fluidized-bed burners, which remove the graphite (carbon) matrix from the crushed HTGR fuel by high temperature (900 0 C) oxidation. The burners are controlled by a digital process controller with an all analog input/output interface which has been in use since March, 1976. The advantages of such a control system to a pilot plant operation can be summarized as follows: (1) Control loop functions and configurations can be changed easily; (2) control constants, alarm limits, output limits, and scaling constants can be changed easily; (3) calculation of data and/or interface with a computerized information retrieval system during operation are available; (4) diagnosis of process control problems is facilitated; and (5) control panel/room space is saved

  9. The performative pleasure of imprecision: a diachronic study of entrainment in music performance

    Directory of Open Access Journals (Sweden)

    Andrew eGeeves

    2014-10-01

    Full Text Available This study focuses in on a moment of live performance in which the entrainment amongst a musical quartet is threatened. Entrainment is asymmetric in so far as there is an ensemble leader who improvises and expands the structure of a last chorus of a piece of music beyond the limits tacitly negotiated during prior rehearsals and performances. Despite the risk of entrainment being disturbed and performance interrupted, the other three musicians in the quartet follow the leading performer and smoothly transition into unprecedented performance territory. We use this moment of live performance to work back through the fieldwork data, building a diachronic study of the development and bases of entrainment in live music performance. We introduce the concept of entrainment and profile previous theory and research relevant to entrainment in music performance. After outlining our methodology, we trace the evolution of the structure of the piece of music from first rehearsal to final performance. Using video clip analysis, interviews and field notes we consider how entrainment shaped and was shaped by the moment of performance in focus. The sense of trust between quartet musicians is established through entrainment processes, is consolidated via smooth adaptation to the threats of disruption. Nonverbal communicative exchanges, via eye contact, gesture and spatial proximity, sustain entrainment through phase shifts occurring swiftly and on the fly in performance contexts. These exchanges permit smooth adaptation promoting trust. This frees the quartet members to play with the potential disturbance of equilibrium inherent in entrained relationships and to play with this tension in an improvisatory way that enhances audience engagement and the live quality of performance.

  10. Turbulent entrainment across turbulent-nonturbulent interfaces in stably stratified mixing layers

    Science.gov (United States)

    Watanabe, T.; Riley, J. J.; Nagata, K.

    2017-10-01

    The entrainment process in stably stratified mixing layers is studied in relation to the turbulent-nonturbulent interface (TNTI) using direct numerical simulations. The statistics are calculated with the interface coordinate in an Eulerian frame as well as with the Lagrangian fluid particles entrained from the nonturbulent to the turbulent regions. The characteristics of entrainment change as the buoyancy Reynolds number Reb decreases and the flow begins to layer. The baroclinic torque delays the enstrophy growth of the entrained fluids at small Reb, while this effect is less efficient for large Reb. The entrained particle movement within the TNTI layer is dominated by the small dissipative scales, and the rapid decay of the kinetic energy dissipation rate due to buoyancy causes the entrained particle movement relative to the interface location to become slower. Although the Eulerian statistics confirm that there exists turbulent fluid with strong vorticity or with large buoyancy frequency near the TNTI, the entrained fluid particles circumvent these regions by passing through the TNTI in strain-dominant regions or in regions with small buoyancy frequency. The multiparticle statistics show that once the nonturbulent fluid volumes are entrained, they are deformed into flattened shapes in the vertical direction and diffuse in the horizontal direction. When Reb is large enough for small-scale turbulence to exist, the entrained fluid is able to penetrate into the turbulent core region. Once the flow begins to layer with decreasing Reb, however, the entrained fluid volume remains near the outer edge of the turbulent region and forms a stably stratified layer without vertical overturning.

  11. Temperature compensation and entrainment in circadian rhythms

    International Nuclear Information System (INIS)

    Bodenstein, C; Heiland, I; Schuster, S

    2012-01-01

    To anticipate daily variations in the environment and coordinate biological activities into a daily cycle many organisms possess a circadian clock. In the absence of external time cues the circadian rhythm persists with a period of approximately 24 h. The clock phase can be shifted by single pulses of light, darkness, chemicals, or temperature and this allows entrainment of the clock to exactly 24 h by cycles of these zeitgebers. On the other hand, the period of the circadian rhythm is kept relatively constant within a physiological range of constant temperatures, which means that the oscillator is temperature compensated. The mechanisms behind temperature compensation and temperature entrainment are not fully understood, neither biochemically nor mathematically. Here, we theoretically investigate the interplay of temperature compensation and entrainment in general oscillatory systems. We first give an analytical treatment for small temperature shifts and derive that every temperature-compensated oscillator is entrainable to external small-amplitude temperature cycles. Temperature compensation ensures that this entrainment region is always centered at the endogenous period regardless of possible seasonal temperature differences. Moreover, for small temperature cycles the entrainment region of the oscillator is potentially larger for rectangular pulses. For large temperature shifts we numerically analyze different circadian clock models proposed in the literature with respect to these properties. We observe that for such large temperature shifts sinusoidal or gradual temperature cycles allow a larger entrainment region than rectangular cycles. (paper)

  12. Improvement of the Zircaloy fuel can manufacturing process

    International Nuclear Information System (INIS)

    1986-01-01

    The following work has been performed in order to ensure more reliable supply of start material for the manufacture of Zy-2 and Zy-4 fuel cans, and to improve the processing techniques and product quality: 1) Two complete production campaigns with the ingot suppliers Western Zirconium and Ugine Aciers. 2) Development of new ingot dimensions (rolling tests). 3) Development of a mechanized washing and cleansing procedure. 4) Development of a new abrasive treatment technique (wet sand blasting). (orig./HP) [de

  13. Non-slag co-gasification of biomass and coal in entrained-bed furnace

    Science.gov (United States)

    Itaya, Yoshinori; Suami, Akira; Kobayashi, Nobusuke

    2018-02-01

    Gasification is a promising candidate of processes to upgrade biomass and to yield clean gaseous fuel for utilization of renewable energy resources. However, a sufficient amount of biomass is not always available to operate a large scale of the plant. Co-gasification of biomass with coal is proposed as a solution of the problem. Tar emission is another subject during operation in shaft or kiln type of gasifiers employed conventionally for biomass. The present authors proposed co-gasification of biomass and coal in entrained-bed furnace, which is a representative process without tar emission under high temperature, but operated so to collect dust as flyash without molten slag formation. This paper presents the works performed on co-gasification performance of biomass and pulverized coal to apply to entrained-bed type of furnaces. At first, co-gasification of woody powder and pulverized coal examined using the lab-scale test furnace of the down-flow entrained bed showed that the maximum temperatures in the furnace was over 1500 K and the carbon conversion to gas achieved at higher efficiency than 80-90 percent although the residence time in the furnace was as short as a few seconds. Non-slag co-gasification was carried out successfully without slag formation in the furnace if coal containing ash with high fusion temperature was employed. The trend suggesting the effect of reaction rate enhancement of co-gasification was also observed. Secondary, an innovative sewage sludge upgrading system consisting of self-energy recovery processes was proposed to yield bio-dried sludge and to sequentially produce char without adding auxiliary fuel. Carbonization behavior of bio-dried sludge was evaluated through pyrolysis examination in a lab-scale quartz tube reactor. The thermal treatment of pyrolysis of sludge contributed to decomposition and removal of contaminant components such as nitrogen and sulfur. The gasification kinetics of sludge and coal was also determined by a

  14. Neurobiological foundations of neurologic music therapy: rhythmic entrainment and the motor system.

    Science.gov (United States)

    Thaut, Michael H; McIntosh, Gerald C; Hoemberg, Volker

    2014-01-01

    Entrainment is defined by a temporal locking process in which one system's motion or signal frequency entrains the frequency of another system. This process is a universal phenomenon that can be observed in physical (e.g., pendulum clocks) and biological systems (e.g., fire flies). However, entrainment can also be observed between human sensory and motor systems. The function of rhythmic entrainment in rehabilitative training and learning was established for the first time by Thaut and colleagues in several research studies in the early 1990s. It was shown that the inherent periodicity of auditory rhythmic patterns could entrain movement patterns in patients with movement disorders (see for a review: Thaut et al., 1999). Physiological, kinematic, and behavioral movement analysis showed very quickly that entrainment cues not only changed the timing of movement but also improved spatial and force parameters. Mathematical models have shown that anticipatory rhythmic templates as critical time constraints can result in the complete specification of the dynamics of a movement over the entire movement cycle, thereby optimizing motor planning and execution. Furthermore, temporal rhythmic entrainment has been successfully extended into applications in cognitive rehabilitation and speech and language rehabilitation, and thus become one of the major neurological mechanisms linking music and rhythm to brain rehabilitation. These findings provided a scientific basis for the development of neurologic music therapy.

  15. Neurobiological foundations of neurologic music therapy: rhythmic entrainment and the motor system

    Science.gov (United States)

    Thaut, Michael H.; McIntosh, Gerald C.; Hoemberg, Volker

    2015-01-01

    Entrainment is defined by a temporal locking process in which one system’s motion or signal frequency entrains the frequency of another system. This process is a universal phenomenon that can be observed in physical (e.g., pendulum clocks) and biological systems (e.g., fire flies). However, entrainment can also be observed between human sensory and motor systems. The function of rhythmic entrainment in rehabilitative training and learning was established for the first time by Thaut and colleagues in several research studies in the early 1990s. It was shown that the inherent periodicity of auditory rhythmic patterns could entrain movement patterns in patients with movement disorders (see for a review: Thaut et al., 1999). Physiological, kinematic, and behavioral movement analysis showed very quickly that entrainment cues not only changed the timing of movement but also improved spatial and force parameters. Mathematical models have shown that anticipatory rhythmic templates as critical time constraints can result in the complete specification of the dynamics of a movement over the entire movement cycle, thereby optimizing motor planning and execution. Furthermore, temporal rhythmic entrainment has been successfully extended into applications in cognitive rehabilitation and speech and language rehabilitation, and thus become one of the major neurological mechanisms linking music and rhythm to brain rehabilitation. These findings provided a scientific basis for the development of neurologic music therapy. PMID:25774137

  16. Neurobiological Foundations of Neurologic Music Therapy: Rhythmic Entrainment and the Motor System

    Directory of Open Access Journals (Sweden)

    Michael eThaut

    2015-02-01

    Full Text Available AbstractEntrainment is defined by a temporal locking process in which one system’s motion or signal frequency entrains the frequency of another system. This process is a universal phenomenon that can be observed in physical (e.g., pendulum clocks and biological systems (e.g. fire flies. However, entrainment can also be observed between human sensory and motor systems. The function of rhythmic entrainment in rehabilitative training and learning was established for the first time by Thaut and colleagues in several research studies in the early 1990s. It was shown that the inherent periodicity of auditory rhythmic patterns could entrain movement patterns in patients with movement disorders (see for a review: Thaut et al, 1999. Physiological, kinematic and behavioral movement analysis showed very quickly that entrainment cues not only changed the timing of movement but also improved spatial and force parameters. Mathematical models have shown that anticipatory rhythmic templates as critical time constraints can result in the complete specification of the dynamics of a movement over the entire movement cycle, thereby optimizing motor planning and execution. Furthermore, temporal rhythmic entrainment has been successfully extended into applications in cognitive rehabilitation and speech and language rehabilitation, and thus become one of the major neurological mechanisms linking music and rhythm to brain rehabilitation. These findings provided a scientific basis for the development of Neurologic Music Therapy.

  17. Composite Fe - BaCe0.2Zr0.6Y0.2O2.9 Anodes for Proton Conductor Fuel Cells

    DEFF Research Database (Denmark)

    Lapina, Alberto; Chatzichristodoulou, Christodoulos; Holtappels, Peter

    2014-01-01

    Symmetrical cells with Fe - BaCe0.2Zr0.6Y0.2O2.9 composite electrodes are produced by screen printing and infiltration, using BaCe0.2Zr0.6Y0.2O2.9 as electrolyte. The electrochemical performance of the composite electrode is studied by impedance spectroscopy at 250–500◦C in dry and wet hydrogen/n...

  18. Process for the fabrication of nuclear fuel oxide pellets

    International Nuclear Information System (INIS)

    Francois, Bernard; Paradis, Yves.

    1977-01-01

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

  19. Smelting Associated with the Advanced Spent Fuel Conditioning Process

    International Nuclear Information System (INIS)

    Hur, J-M.; Jeong, M-S.; Lee, W-K.; Cho, S-H.; Seo, C-S.; Park, S-W.

    2004-01-01

    The smelting process associated with the advanced spent fuel conditioning process (ACP) of Korea Atomic Energy Research Institute was studied by using surrogate materials. Considering the vaporization behaviors of input materials, the operation procedure of smelting was set up as (1) removal of residual salts, (2) melting of metal powder, and (3) removal of dross from a metal ingot. The behaviors of porous MgO crucible during smelting were tested and the chemical stability of MgO in the salt-being atmosphere was confirmed

  20. A survey of processes for producing hydrogen fuel from different sources for automotive-propulsion fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Brown, L.F.

    1996-03-01

    Seven common fuels are compared for their utility as hydrogen sources for proton-exchange-membrane fuel cells used in automotive propulsion. Methanol, natural gas, gasoline, diesel fuel, aviation jet fuel, ethanol, and hydrogen are the fuels considered. Except for the steam reforming of methanol and using pure hydrogen, all processes for generating hydrogen from these fuels require temperatures over 1000 K at some point. With the same two exceptions, all processes require water-gas shift reactors of significant size. All processes require low-sulfur or zero-sulfur fuels, and this may add cost to some of them. Fuels produced by steam reforming contain {approximately}70-80% hydrogen, those by partial oxidation {approximately}35-45%. The lower percentages may adversely affect cell performance. Theoretical input energies do not differ markedly among the various processes for generating hydrogen from organic-chemical fuels. Pure hydrogen has severe distribution and storage problems. As a result, the steam reforming of methanol is the leading candidate process for on-board generation of hydrogen for automotive propulsion. If methanol unavailability or a high price demands an alternative process, steam reforming appears preferable to partial oxidation for this purpose.

  1. Technical and regulatory review of the Rover nuclear fuel process for use on Fort St. Vrain fuel

    International Nuclear Information System (INIS)

    Hertzler, T.

    1993-02-01

    This report describes the results of an analysis for processing and final disposal of Fort St. Vrain (FSV) irradiated fuel in Rover-type equipment or technologies. This analysis includes an evaluation of the current Rover equipment status and the applicability of this technology in processing FSV fuel. The analyses are based on the physical characteristics of the FSV fuel and processing capabilities of the Rover equipment. Alternate FSV fuel disposal options are also considered including fuel-rod removal from the block, disposal of the empty block, or disposal of the entire fuel-containing block. The results of these analyses document that the current Rover hardware is not operable for any purpose, and any effort to restart this hardware will require extensive modifications and re-evaluation. However, various aspects of the Rover technology, such as the successful fluid-bed burner design, can be applied with modification to FSV fuel processing. The current regulatory climate and technical knowledge are not adequately defined to allow a complete analysis and conclusion with respect to the disposal of intact fuel blocks with or without the fuel rods removed. The primary unknowns include the various aspects of fuel-rod removal from the block, concentration of radionuclides remaining in the graphite block after rod removal, and acceptability of carbon in the form of graphite in a high level waste repository

  2. Quality control of CANDU6 fuel element in fabrication process

    International Nuclear Information System (INIS)

    Li Yinxie; Zhang Jie

    2012-01-01

    To enhance the fine control over all aspects of the production process, improve product quality, fuel element fabrication process for CANDU6 quality process control activities carried out by professional technical and management technology combined mode, the quality of the fuel elements formed around CANDU6 weak links - - end plug , and brazing processes and procedures associated with this aspect of strict control, in improving staff quality consciousness, strengthening equipment maintenance, improved tooling, fixtures, optimization process test, strengthen supervision, fine inspection operations, timely delivery carry out aspects of the quality of information and concerns the production environment, etc., to find the problem from the improvement of product quality and factors affecting the source, and resolved to form the active control, comprehensive and systematic analysis of the problem of the quality management concepts, effectively reducing the end plug weld microstructure after the failure times and number of defects zirconium alloys brazed, improved product quality, and created economic benefits expressly provided, while staff quality consciousness and attention to detail, collaboration department, communication has been greatly improved and achieved very good management effectiveness. (authors)

  3. Iodine-129 in aquatic organisms near nuclear fuels processing plants

    International Nuclear Information System (INIS)

    Watson, D.G.

    1975-04-01

    Concentrations of 129 I in two aquatic habitats near nuclear fuel processing plants were highest in algae and crustaceans. These two forms may be useful in future monitoring of 129 I. There is some indication of an increase in atom ratios and specific activity in aquatic organisms over that in water and sediments. Additional measurements should be made to verify this conclusion. Efforts should continue to measure the possible long term build-up of 129 I in aquatic environments receiving effluents from fuels reprocessing plants. Even at very low rates of release to the environment, the long physical half-life of 129 I creates the potential for build-up of this nuclide to significant levels. (U.S.)

  4. Use of Hansen Solubility Parameters in Fuel Treatment Processes

    Science.gov (United States)

    2014-03-17

    Clearance # Considerations for Rocket Fuel Objective: Utilize liquid/liquid extraction process to improve performance, increase availability, and...1/4)(H1 - H0)2 - (D2 – D0)2 - (1/4) (P2 - P0)2 - (1/4)(H2 - H0)2 ] + RT ln (V1/ V2 ) K = C0,2 / CO,1 Partition coefficient RT ln K = V0( D1...02 – D2-02 ) + RT ln (V1/ V2 ) Di-0 is the distance in “solubility parameter space” between liquid i and impurity 0. For reference, phase 1 = fuel

  5. High performance fuel electrodes fabricated by electroless plating of copper on BaZr0.8Ce0.1Y0.1O3-δ proton-conducting ceramic

    Science.gov (United States)

    Patki, Neil S.; Way, J. Douglas; Ricote, Sandrine

    2017-10-01

    The stability of copper at high temperatures in reducing and hydrocarbon-containing atmospheres makes it a good candidate for fabricating fuel electrodes on proton-conducting ceramics, such as BaZr0.9-xCexY0.1O3-δ (BZCY). In this work, the electrochemical performance of Cu-based electrodes fabricated by electroless plating (ELP) on BaZr0.8Ce0.1Y0.1O3-δ is studied with impedance spectroscopy. Three activation catalysts (Pd, Ru, and Cu) are investigated and ELP is compared to a commercial Cu paste (ESL 2312-G) for electrode fabrication. The area specific resistances (ASR) for Pd, Ru, and Cu activations at 700 °C in moist 5% H2 in Ar are 2.1, 3.2, and 13.4 Ω cm2, respectively. That is a 1-2 orders of magnitude improvement over the commercial Cu paste (192 Ω cm2). Furthermore, the ASR has contributions from electrode processes and charge transfer at the electrode/electrolyte interface. Additionally, the morphology of the as-fabricated electrode is unaffected by the activation catalyst. However, heat treatment at 750 °C in H2 for 24 h leads to sintering and large reorganization of the electrode fabricated with Cu activation (micron sized pores seen in the tested sample), while Pd and Ru activations are immune to such reorganization. Thus, Pd and Ru are identified as candidates for future work with improvements to charge transfer required for the former, and better electrode processes required for the latter.

  6. Entrainment: an annotated bibliography. Interim report

    International Nuclear Information System (INIS)

    Carrier, R.F.; Hannon, E.H.

    1979-04-01

    The 604 annotated references in this bibliography on the effects of pumped entrainment of aquatic organisms through the cooling systems of thermal power plants were compiled from published and unpublished literature and cover the years 1947 through 1977. References to published literature were obtained by searching large-scale commercial data bases, ORNL in-house-generated data bases, relevant journals, and periodical bibliographies. The unpublished literature is a compilation of Sections 316(a) and 316(b) demonstrations, environmental impact statements, and environmental reports prepared by the utilities in compliance with Federal Water Pollution Control Administration regulations. The bibliography includes references on monitoring studies at power plant sites, laboratory studies of physical and biological effects on entrained organisms, engineering strategies for the mitigation of entrainment effects, and selected theoretical studies concerned with the methodology for determining entrainment effects

  7. A model study of mixing and entrainment in the horizontally evolving atmospheric convective boundary layer

    Energy Technology Data Exchange (ETDEWEB)

    Fedorovich, E.; Kaiser, R. [Univ. Karlsruhe, Inst. fuer Hydrologie und Wasserwirtschaft (Germany)

    1997-10-01

    We present results from a parallel wind-tunnel/large-eddy simulation (LES) model study of mixing and entrainment in the atmospheric convective boundary layer (CBL) longitudinally developing over a heated surface. The advection-type entrainment of warmer air from upper turbulence-free layers into the growing CBL has been investigated. Most of numerical and laboratory model studies of the CBL carried out so far dealt with another type of entrainment, namely the non-steady one, regarding the CBL growth as a non-stationary process. In the atmosphere, both types of the CBL development can take place, often being superimposed. (au)

  8. Red electroluminescent process excited by hot holes in SrGa2S4:Ce, Mn thin film

    International Nuclear Information System (INIS)

    Tanaka, Katsu; Okamoto, Shinji

    2009-01-01

    This paper reports the first observation of red electroluminescence (EL) in SrGa 2 S 4 :Ce, Mn thin film. The EL spectrum consists of single broad emission band having a peak wavelength of 665 nm. The dominant EL decay time was 31 μs. The relationship between the applied voltage and the EL waveform was measured in single insulating thin film electroluminescent (TFEL) devices. An asymmetric EL waveform was observed in SrGa 2 S 4 :Ce, Mn TFEL devices under a rectangular applied voltage. The polarity of the EL waveform in these devices was different from the waveform in manganese-activated zinc sulfide ZnS:Mn devices. This indicates that hot holes excite the Mn 2+ ions to cause the red EL.

  9. Universal entrainment mechanism controls contact times with motile cells

    Science.gov (United States)

    Mathijssen, Arnold J. T. M.; Jeanneret, Raphaël; Polin, Marco

    2018-03-01

    Contact between particles and motile cells underpins a wide variety of biological processes, from nutrient capture and ligand binding to grazing, viral infection, and cell-cell communication. The window of opportunity for these interactions depends on the basic mechanism determining contact time, which is currently unknown. By combining experiments on three different species—Chlamydomonas reinhardtii, Tetraselmis subcordiforms, and Oxyrrhis marina—with simulations and analytical modeling, we show that the fundamental physical process regulating proximity to a swimming microorganism is hydrodynamic particle entrainment. The resulting distribution of contact times is derived within the framework of Taylor dispersion as a competition between advection by the cell surface and microparticle diffusion, and predicts the existence of an optimal tracer size that is also observed experimentally. Spatial organization of flagella, swimming speed, and swimmer and tracer size influence entrainment features and provide tradeoffs that may be tuned to optimize the estimated probabilities for microbial interactions like predation and infection.

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

    Energy Technology Data Exchange (ETDEWEB)

    Stutz, M. J.

    2007-07-01

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

  11. U-10Mo Baseline Fuel Fabrication Process Description

    Energy Technology Data Exchange (ETDEWEB)

    Hubbard, Lance R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Arendt, Christina L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Dye, Daniel F. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Clayton, Christopher K. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lerchen, Megan E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lombardo, Nicholas J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lavender, Curt A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Zacher, Alan H. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2017-09-27

    This document provides a description of the U.S. High Power Research Reactor (USHPRR) low-enriched uranium (LEU) fuel fabrication process. This document is intended to be used in conjunction with the baseline process flow diagram (PFD) presented in Appendix A. The baseline PFD is used to document the fabrication process, communicate gaps in technology or manufacturing capabilities, convey alternatives under consideration, and as the basis for a dynamic simulation model of the fabrication process. The simulation model allows for the assessment of production rates, costs, and manufacturing requirements (manpower, fabrication space, numbers and types of equipment, etc.) throughout the lifecycle of the USHPRR program. This document, along with the accompanying PFD, is updated regularly

  12. Techniques for laser processing, assay, and examination of spent fuel

    International Nuclear Information System (INIS)

    Gray, J.H.; Mitchell, R.C.; Rogell, M.L.

    1981-11-01

    Fuel examination studies were performed which have application to interim spent fuel storage. These studies were in three areas, i.e., laser drilling and rewelding demonstration, nondestructive assay techniques survey, and fuel examination techniques survey

  13. Progress in fuel processing for PEMFC systems for transport applications

    Energy Technology Data Exchange (ETDEWEB)

    Dams, A J; Hayter, P R; Moore, S C

    1998-07-01

    Wellman CJB Limited has been developing fuel processors for PEMFC systems for transport applications using a range of feedstocks. Feedstocks that can be processed to produce a hydrogen-rich gas stream suitable for use with a PEMFC include methanol, gasoline, diesel, LPG, dimethylether, marine diesel and aviation fuel. The basic fuel processor is a steam reformer combined with a selective carbon monoxide oxidation stage. Depending on the nature of the liquid feedstock, other process steps will be required such as vaporizer, desulfurizer, pre-reformer and high and low temperature shift reactors. Work on methanol reforming has been specifically targeted at a PEMFC driven passenger car as part of a multinational European Community JOULE programme called MERCATOX. The objective is to develop and test a compact and fast response methanol reformer and gas clean-up unit to meet a car manufacturer's specification. The method of construction is to coat a methanol reforming catalyst onto one side of a metal corrugated plate. On the other side is a coated combustion catalyst which burns fuel cell off-gas to provide the endothermic heat for the methanol reforming reaction. A number of these plates are assembled in a compact unit ensuring good heat transfer. The gas clean-up unit is similarly constructed with a selective oxidation catalyst on one side and a thermal fluid on the other. Initial tests have indicated a superior performance to conventional packed bed reformers in terms of response and start-up time. Steam reforming of gasoline, diesel, LPG, dimethylether, marine diesel and aviation fuel has been demonstrated on a bench scale (0.5kW). The process steps commence with vaporization (except for LPG), desulfurization (except for dimethylether), prereforming, reforming, low and high temperature shift and selective oxidation. A simple technology demonstrator has shown that a hydrogen-rich mixture (75% hydrogen, 25% carbon dioxide) with less than 2ppm carbon monoxide can be

  14. Thermal characteristics during hydrogen fueling process of type IV cylinder

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sung Chan [Department of Fire and Disaster Prevention, Kyungil University, 33, Buhori, Hayang, Kyungsan 712-701 (Korea); Lee, Seung Hoon; Yoon, Kee Bong [Department of Mechanical Engineering, Chung Ang University, 221, Huksuk, Dongjak, Seoul 156-756 (Korea)

    2010-07-15

    Temperature increase during hydrogen fueling process is a significant safety concern of a high pressure hydrogen vessel. Hence, thermal characteristics of a Type IV cylinder during hydrogen filling process need to be understood. In this study, a series of experiments were conducted to quantify the temperature change of the cylinder during hydrogen filling to 35 MPa. Computational fluid dynamics (CFD) analysis was also conducted to simulate the conditions of the experiments. The results predicted by the CFD analysis show reasonable agreement with the experiments and the discrepancy between the CFD results and experimental results decrease with higher initial gas pressures. The upper and the lower parts of the vessel showed a temperature difference in the vertical direction. The upper gas temperature was higher than that of the lower part due to the buoyancy effect in the vessel. The maximum gas temperature was higher than the maximum temperature allowed in the ISO safety code (85 C) for the case in which the vessel was pressurized from 0 MPa to 35 MPa. This work contributes to the understanding of the thermal flow characteristics of the hydrogen filling process and notes that additional efforts should be made to guarantee the safety of a type IV cylinder during the hydrogen fueling process. (author)

  15. Low temperature chemical processing of graphite-clad nuclear fuels

    Science.gov (United States)

    Pierce, Robert A.

    2017-10-17

    A reduced-temperature method for treatment of a fuel element is described. The method includes molten salt treatment of a fuel element with a nitrate salt. The nitrate salt can oxidize the outer graphite matrix of a fuel element. The method can also include reduced temperature degradation of the carbide layer of a fuel element and low temperature solubilization of the fuel in a kernel of a fuel element.

  16. Conversion of microalgae to jet fuel: process design and simulation.

    Science.gov (United States)

    Wang, Hui-Yuan; Bluck, David; Van Wie, Bernard J

    2014-09-01

    Microalgae's aquatic, non-edible, highly genetically modifiable nature and fast growth rate are considered ideal for biomass conversion to liquid fuels providing promise for future shortages in fossil fuels and for reducing greenhouse gas and pollutant emissions from combustion. We demonstrate adaptability of PRO/II software by simulating a microalgae photo-bio-reactor and thermolysis with fixed conversion isothermal reactors adding a heat exchanger for thermolysis. We model a cooling tower and gas floatation with zero-duty flash drums adding solids removal for floatation. Properties data are from PRO/II's thermodynamic data manager. Hydrotreating is analyzed within PRO/II's case study option, made subject to Jet B fuel constraints, and we determine an optimal 6.8% bioleum bypass ratio, 230°C hydrotreater temperature, and 20:1 bottoms to overhead distillation ratio. Process economic feasibility occurs if cheap CO2, H2O and nutrient resources are available, along with solar energy and energy from byproduct combustion, and hydrotreater H2 from product reforming. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Mechanical separation process for decladding of LWR fuel elements

    International Nuclear Information System (INIS)

    Koch, R.

    1984-10-01

    A comparison of the advantages and disadvantages of known methods of decladding led to cavitation erosion being used as a decladding mechanism. This process attacks not the jacket of the fuel rod but the fuel itself. Cavitation erosion is the consequence of imploding vapour bubbles entailing dynamic stress of a high frequency and high amplitude. The separation effect is due to the different material properties. Ductile materials as a rule are much more resistant to dynamic stress than brittle materials. Systematic experiments at varying pressures, volume flow, nozzle geometries and distances between nozzle and sample led to optimized parameters. There was a conspicuous rise in the relations pressure to depth of erosion and volume flow to depth of erosion. This considered, p=700 bar and d=1.6 mm were found to be useful parameters. The relation of the distance from nozzle to sample and the erosion obtained also has an optimum at s=50 mm. This distance can be shortened in the course of the operation. A great entrance angle combined with a nozzle outlet channel of the length l=1/2 D improves the erosion result considerably. The attack of the cavitating water jet on the jacket of the fuel rod causes a weight loss of [de

  18. Music and emotions: from enchantment to entrainment.

    Science.gov (United States)

    Vuilleumier, Patrik; Trost, Wiebke

    2015-03-01

    Producing and perceiving music engage a wide range of sensorimotor, cognitive, and emotional processes. Emotions are a central feature of the enjoyment of music, with a large variety of affective states consistently reported by people while listening to music. However, besides joy or sadness, music often elicits feelings of wonder, nostalgia, or tenderness, which do not correspond to emotion categories typically studied in neuroscience and whose neural substrates remain largely unknown. Here we review the similarities and differences in the neural substrates underlying these "complex" music-evoked emotions relative to other more "basic" emotional experiences. We suggest that these emotions emerge through a combination of activation in emotional and motivational brain systems (e.g., including reward pathways) that confer its valence to music, with activation in several other areas outside emotional systems, including motor, attention, or memory-related regions. We then discuss the neural substrates underlying the entrainment of cognitive and motor processes by music and their relation to affective experience. These effects have important implications for the potential therapeutic use of music in neurological or psychiatric diseases, particularly those associated with motor, attention, or affective disturbances. © 2015 New York Academy of Sciences.

  19. Advanced hybrid process with solvent extraction and pyro-chemical process of spent fuel reprocessing for LWR to FBR

    International Nuclear Information System (INIS)

    Fujita, Reiko; Mizuguchi, Koji; Fuse, Kouki; Saso, Michitaka; Utsunomiya, Kazuhiro; Arie, Kazuo

    2008-01-01

    Toshiba has been proposing a new fuel cycle concept of a transition from LWR to FBR. The new fuel cycle concept has better economical process of the LWR spent fuel reprocessing than the present Purex Process and the proliferation resistance for FBR cycle of plutonium with minor actinides after 2040. Toshiba has been developing a new Advanced Hybrid Process with Solvent Extraction and Pyrochemical process of spent fuel reprocessing for LWR to FBR. The Advanced Hybrid Process combines the solvent extraction process of the LWR spent fuel in nitric acid with the recovery of high pure uranium for LWR fuel and the pyro-chemical process in molten salts of impure plutonium recovery with minor actinides for metallic FBR fuel, which is the FBR spent fuel recycle system after FBR age based on the electrorefining process in molten salts since 1988. The new Advanced Hybrid Process enables the decrease of the high-level waste and the secondary waste from the spent fuel reprocessing plants. The R and D costs in the new Advanced Hybrid Process might be reduced because of the mutual Pyro-chemical process in molten salts. This paper describes the new fuel cycle concept of a transition from LWR to FBR and the feasibility of the new Advanced Hybrid Process by fundamental experiments. (author)

  20. Pyrolytic electrochemical process for the reprocessing of irradiated nuclear fuels

    International Nuclear Information System (INIS)

    Brambilla, G.; Sartorelli, A.

    1980-01-01

    The reprocessing is aimed at synthetic UO 2 -PuO 2 mixed oxides, UC-PuC mixed carbides and at oxides and carbides of U, Pu and Th from fast nuclear reactors. The nuclear fuel is dissolved in a salt melting bath. The conversion of the Pu(SO 4 ) 2 is done thermally and that of UO 2 is done electrolytically. The molten salts are returned to the input of the process and the fission products and the molten salts are conditioned. (DG) [de

  1. Safeguards System for the Advanced Spent Fuel Conditioning Process Facility

    International Nuclear Information System (INIS)

    Kim, Ho-dong; Lee, T.H.; Yoon, J.S.; Park, S.W; Lee, S.Y.; Li, T.K.; Menlove, H.; Miller, M.C.; Tolba, A.; Zarucki, R.; Shawky, S.; Kamya, S.

    2007-01-01

    The advanced spent fuel conditioning process (ACP) which is a part of a pyro-processing has been under development at Korean Atomic Energy Research Institute (KAERI) since 1997 to tackle the problem of an accumulation of spent fuel. The concept is to convert spent oxide fuel into a metallic form in a high temperature molten salt in order to reduce the heat energy, volume, and radioactivity of a spent fuel. Since the inactive tests of the ACP have been successfully implemented to confirm the validity of the electrolytic reduction technology, a lab-scale hot test will be undertaken in a couple of years to validate the concept. For this purpose, the KAERI has built the ACP Facility (ACPF) at the basement of the Irradiated Material Examination Facility (IMEF) of KAERI, which already has a reserved hot-cell area. Through the bilateral arrangement between US Department of Energy (DOE) and Korean Ministry of Science and Technology (MOST) for safeguards R and D, the KAERI has developed elements of safeguards system for the ACPF in cooperation with the Los Alamos National Laboratory (LANL). The reference safeguards design conditions and equipment were established for the ACPF. The ACPF safeguards system has many unique design specifications because of the particular characteristics of the pyro-process materials and the restrictions during a facility operation. For the material accounting system, a set of remote operation and maintenance concepts has been introduced for a non-destructive assay (NDA) system. The IAEA has proposed a safeguards approach to the ACPF for the different operational phases. Safeguards measures at the ACPF will be implemented during all operational phases which include a 'Cold Test', a 'Hot Test' and at the end of a 'Hot test'. Optimization of the IAEA's inspection efforts was addressed by designing an effective safeguards approach that relies on, inter alia, remote monitoring using cameras, installed NDA instrumentation, gate monitors and seals

  2. Microbial fuel cell treatment of ethanol fermentation process water

    Science.gov (United States)

    Borole, Abhijeet P [Knoxville, TN

    2012-06-05

    The present invention relates to a method for removing inhibitor compounds from a cellulosic biomass-to-ethanol process which includes a pretreatment step of raw cellulosic biomass material and the production of fermentation process water after production and removal of ethanol from a fermentation step, the method comprising contacting said fermentation process water with an anode of a microbial fuel cell, said anode containing microbes thereon which oxidatively degrade one or more of said inhibitor compounds while producing electrical energy or hydrogen from said oxidative degradation, and wherein said anode is in electrical communication with a cathode, and a porous material (such as a porous or cation-permeable membrane) separates said anode and cathode.

  3. Zeolites as Catalysts for Fuels Refining after Indirect Liquefaction Processes

    Directory of Open Access Journals (Sweden)

    Arno de Klerk

    2018-01-01

    Full Text Available The use of zeolite catalysts for the refining of products from methanol synthesis and Fisher–Tropsch synthesis was reviewed. The focus was on fuels refining processes and differences in the application to indirect liquefaction products was compared to petroleum, which is often a case of managing different molecules. Processes covered were skeletal isomerisation of n-butenes, hydroisomerisation of n-butane, aliphatic alkylation, alkene oligomerisation, methanol to hydrocarbons, ethanol and heavier alcohols to hydrocarbons, carbonyls to hydrocarbons, etherification of alkenes with alcohols, light naphtha hydroisomerisation, catalytic naphtha reforming, hydroisomerisation of distillate, hydrocracking and fluid catalytic cracking. The zeolite types that are already industrially used were pointed out, as well as zeolite types that have future promise for specific conversion processes.

  4. NEW MATERIAL NEEDS FOR HYDROCARBON FUEL PROCESSING: Generating Hydrogen for the PEM Fuel Cell

    Science.gov (United States)

    Farrauto, R.; Hwang, S.; Shore, L.; Ruettinger, W.; Lampert, J.; Giroux, T.; Liu, Y.; Ilinich, O.

    2003-08-01

    The hydrogen economy is fast approaching as petroleum reserves are rapidly consumed. The fuel cell promises to deliver clean and efficient power by combining hydrogen and oxygen in a simple electrochemical device that directly converts chemical energy to electrical energy. Hydrogen, the most plentiful element available, can be extracted from water by electrolysis. One can imagine capturing energy from the sun and wind and/or from the depths of the earth to provide the necessary power for electrolysis. Alternative energy sources such as these are the promise for the future, but for now they are not feasible for power needs across the globe. A transitional solution is required to convert certain hydrocarbon fuels to hydrogen. These fuels must be available through existing infrastructures such as the natural gas pipeline. The present review discusses the catalyst and adsorbent technologies under development for the extraction of hydrogen from natural gas to meet the requirements for the proton exchange membrane (PEM) fuel cell. The primary market is for residential applications, where pipeline natural gas will be the source of H2 used to power the home. Other applications including the reforming of methanol for portable power applications such as laptop computers, cellular phones, and personnel digital equipment are also discussed. Processing natural gas containing sulfur requires many materials, for example, adsorbents for desulfurization, and heterogeneous catalysts for reforming (either autothermal or steam reforming) water gas shift, preferential oxidation of CO, and anode tail gas combustion. All these technologies are discussed for natural gas and to a limited extent for reforming methanol.

  5. AECL's progress in developing the DUPIC fuel fabrication process

    International Nuclear Information System (INIS)

    Sullivan, J.D.; Cox, D.S.

    1995-01-01

    Spent Pressurized Water Reactor (PWR) fuel can be used directly in CANDU reactors without the need for wet chemical reprocessing or reenrichment. Considerable experimental progress has been made in verifying the practicality of this fuel cycle, including hot-cell experiments using spent PWR fuels and out-cell trials using surrogate fuels. This paper describes the current status of these experiments. (author)

  6. Measurements of air entrainment by vertical plunging liquid jets

    Science.gov (United States)

    El Hammoumi, M.; Achard, J. L.; Davoust, L.

    2002-06-01

    This paper addresses the issue of the air-entrainment process by a vertical plunging liquid jet. A non-dimensional physical analysis, inspired by the literature on the stability of free jets submitted to an aerodynamic interaction, was developed and yielded two correlation equations for the laminar and the turbulent plunging jets. These correlation equations allow the volumetric flow rate of the air carryunder represented by the Weber number of entrainment We n to be predicted. The plunging jets under consideration issued from circular tubes long enough to achieve a fully developed flow at the outlet. A sensitive technique based on a rising soap meniscus was developed to measure directly the volumetric flow rate of the air carryunder. Our data are compared with other experimental data available in the literature; they also stand as a possible database for future theoretical modelling.

  7. Measurements of air entrainment by vertical plunging liquid jets

    Energy Technology Data Exchange (ETDEWEB)

    El Hammoumi, M. [Faculte des Sciences et Techniques, Departement de Physique, Laboratoire de Mecanique Appliquee, Fes (Morocco); Achard, J.L.; Davoust, L. [Laboratoire des Ecoulements Geophysiques et Industriels (LEGI), Grenoble (France)

    2002-06-01

    This paper addresses the issue of the air-entrainment process by a vertical plunging liquid jet. A non-dimensional physical analysis, inspired by the literature on the stability of free jets submitted to an aerodynamic interaction, was developed and yielded two correlation equations for the laminar and the turbulent plunging jets. These correlation equations allow the volumetric flow rate of the air carryunder represented by the Weber number of entrainment We{sub n} to be predicted. The plunging jets under consideration issued from circular tubes long enough to achieve a fully developed flow at the outlet. A sensitive technique based on a rising soap meniscus was developed to measure directly the volumetric flow rate of the air carryunder. Our data are compared with other experimental data available in the literature; they also stand as a possible database for future theoretical modelling. (orig.)

  8. A new technology for air-entrainment of concrete

    DEFF Research Database (Denmark)

    Laustsen, Sara; Hasholt, Marianne Tange; Jensen, Ole Mejlhede

    2008-01-01

    This paper describes a new technology for air-entrainment of concrete. The technology is based on the addition of dry superabsorbent polymers (SAP) to the concrete. A large amount of small internal water reservoirs are formed during mixing when SAP absorbs water and swells. The internal water......-entrainment include stability of the air void system and improved control of both the amount of added air and the air void size. The new technology based on SAP has been tested in freeze-thaw experiments, where the amount of surface scaling was measured. The results clearly show that SAP is beneficial for frost...... reservoirs are distributed throughout the concrete. During the hydration process the cement paste imbibes water from the water-filled SAP voids. Thereby the water-filled SAP voids turn into partly air-filled voids. The advantages of the SAP-based technology compared to traditional chemical air...

  9. Transcriptome Changes in Douglas-fir (Pseudotsuga menziesii) Induced by Exposure to Diesel Emissions Generated with CeO2 Nanoparticle Fuel Additive

    Science.gov (United States)

    When cerium oxide nanoparticles are added to diesel fuel, fuel burning efficiency increases, producing emissions (DECe) with characteristics that differ from conventional diesel exhaust (DE). It has previously been shown that DECe induces more adverse pulmonary effects in rats on...

  10. Entrainment Zone Characteristics and Entrainment Rates in Cloud-Topped Boundary Layers from DYCOMS-II

    Science.gov (United States)

    2012-03-01

    Malinowski , J. L. Brenguier, and F. Burnet, 2005: Holes and entrainment in stratocumulus. J. Atmos. Sci., 62, 443–459. Glickman, T. S...of the Entrainment Zone in Cloud-topped Boundary Layers. Department of Meteorology, NPS, 93 pp. Krzysztof, Haman E., S. P. Malinowski , M. J

  11. Large Eddy Simulation of Heat Entrainment Under Arctic Sea Ice

    Science.gov (United States)

    Ramudu, Eshwan; Gelderloos, Renske; Yang, Di; Meneveau, Charles; Gnanadesikan, Anand

    2018-01-01

    Arctic sea ice has declined rapidly in recent decades. The faster than projected retreat suggests that free-running large-scale climate models may not be accurately representing some key processes. The small-scale turbulent entrainment of heat from the mixed layer could be one such process. To better understand this mechanism, we model the Arctic Ocean's Canada Basin, which is characterized by a perennial anomalously warm Pacific Summer Water (PSW) layer residing at the base of the mixed layer and a summertime Near-Surface Temperature Maximum (NSTM) within the mixed layer trapping heat from solar radiation. We use large eddy simulation (LES) to investigate heat entrainment for different ice-drift velocities and different initial temperature profiles. The value of LES is that the resolved turbulent fluxes are greater than the subgrid-scale fluxes for most of our parameter space. The results show that the presence of the NSTM enhances heat entrainment from the mixed layer. Additionally there is no PSW heat entrained under the parameter space considered. We propose a scaling law for the ocean-to-ice heat flux which depends on the initial temperature anomaly in the NSTM layer and the ice-drift velocity. A case study of "The Great Arctic Cyclone of 2012" gives a turbulent heat flux from the mixed layer that is approximately 70% of the total ocean-to-ice heat flux estimated from the PIOMAS model often used for short-term predictions. Present results highlight the need for large-scale climate models to account for the NSTM layer.

  12. Particle Entrainment under Turbulent Flow Conditions

    Science.gov (United States)

    Diplas, Panayiotis

    2009-11-01

    Erosion, transportation and deposition of sediments and pollutants influence the hydrosphere, pedosphere, biosphere and atmosphere in profound ways. The global amount of sediment eroded annually over the continental surface of the earth via the action of water and wind is estimated to be around 80 billion metric tons, with 20 of them delivered by rivers to the oceans. This redistribution of material over the surface of the earth affects most of its physical, chemical and biological processes in ways that are exceedingly difficult to comprehend. The criterion currently in use for predicting particle entrainment, originally proposed by Shields in 1936, emphasizes the time-averaged boundary shear stress and therefore is incapable of accounting for the fluctuating forces encountered in turbulent flows. A new criterion that was developed recently in an effort to overcome the limitations of the previous approach will be presented. It is hypothesized that not only the magnitude, but also the duration of energetic near bed turbulent events is relevant in predicting grain removal from the bed surface. It is therefore proposed that the product of force and its duration, or impulse, is a more appropriate and universal criterion for identifying conditions suitable for particle dislodgement. Analytical formulation of the problem and experimental data are used to examine the validity of the new criterion.

  13. Electrochemical performance of Nd1.8Ce0.2CuO4+δ:Ce0.9Gd0.1O2 composite cathode for intermediate temperature solid oxide fuel cells

    International Nuclear Information System (INIS)

    Khandale, A.P.; Bhoga, S.S.

    2012-01-01

    Intermediate temperature solid oxide fuel cells (IT-SOFCs) are viewed as a promising power generation systems with high efficiency and low pollution. Recently, mixed ionic-electronic conductors (MIECs), with K 2 NiF 4 - type structure, attracted much attention as cathode for IT-SOFC

  14. An Update on NiCE Support for BISON

    Energy Technology Data Exchange (ETDEWEB)

    McCaskey, Alex [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Billings, Jay Jay [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Deyton, Jordan H. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Wojtowicz, Anna [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-09-01

    The Nuclear Energy Advanced Modeling and Simulation program (NEAMS) from the Department of Energy s Office of Nuclear Energy has funded the development of a modeling and simulation workflow environment to support the various codes in its nuclear energy scientific computing toolkit. This NEAMS Integrated Computational Environment (NiCE) provides extensible tools and services that enable efficient code execution, input generation, pre-processing visualizations, and post-simulation data analysis and visualization for a large portion of the NEAMS Toolkit. A strong focus for the NiCE development team throughout FY 2015 has been support for the Multiphysics Object Oriented Simulation Environment (MOOSE) and the NEAMS nuclear fuel performance modeling application built on that environment, BISON. There is a strong desire in the program to enable and facilitate the use of BISON throughout nuclear energy research and industry. A primary result of this desire is the need for strong support for BISON in NiCE. This report will detail improvements to NiCE support for BISON. We will present a new and improved interface for interacting with BISON simulations in a variety of ways: (1) improved input model generation, (2) embedded mesh and solution data visualizations, and (3) local and remote BISON simulation launch. We will also show how NiCE has been extended to provide support for BISON code development.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1999-03-01

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

  16. Rework of process effluents from the fabrication of HTR fuel

    Energy Technology Data Exchange (ETDEWEB)

    Lasberg, Ingo; Braehler, Georg [NUKEM Technologies GmbH (Germany); Boyes, David [Pebble Bed Modular Reactor (Pty) Ltd., Centurion (South Africa)

    2008-07-01

    HTR fuel facilities require the application of several liquid chemicals and accordingly they produce significant amounts of Uranium contaminated/potentially contaminated effluents. The main effluents are (amounts for a 3 t Uranium/a plant): aqueous solutions including tetrahydrofurfuryl alcohol THFA, ammonium hydroxide NH4OH, and ammonium nitrate NH4NO3 (180 m{sup 3}/a), isopropanol IPA/water mixtures (130 m{sup 3}/a); Non-Process Water NPW (300 m{sup 3}/a); methanol (7m{sup 3}/a); additionally off-gas streams, containing ammonia (9 t/a) have to be treated. In an industrial scale facility all such effluents/gases need to be processed for recycling, decontamination prior to release to the environment (as waste or as valuable material). Thermal decomposition is applied to dispose of burnable residues.

  17. Process engineering of ceramic composite coatings for fuel cell systems

    Energy Technology Data Exchange (ETDEWEB)

    Li, G.; Kim, H.; Chen, M.; Yang, Q.; Troczynski, T. [British Columbia Univ., Vancouver, BC (Canada). Dept. of Metals and Materials Engineering

    2003-07-01

    Researchers at UBCeram at the Department of Metals and Materials Engineering at the University of British Columbia have developed a technology to chemically bond composite sol-gel (CB-CSG) coating onto metallic surfaces of complex or concave shapes. The process has been optimized for electrically resistive coatings and corrosion-resistant coatings. The CSG is sprayed onto metallic surfaces and is heat-treated at 300 degrees C to partially dehydrate the hydroxides. The CSG film is then chemically bonded through reaction of active alumina with metal phosphates, such as aluminium phosphate. A new chromate-free process is being developed to address the issue of coatings porosity. The electrodeposition technique involves polymer particles mixed with suspended fine alumina particles which are co-deposited by electrophoretic means or by electrocoagulation. The composite e-coatings have excellent mechanical properties and are being considered as a protective coating for various components of fuel cell systems. 9 refs., 7 figs.

  18. Synthesis of Diopside by Solution Combustion Process Using Glycine Fuel

    Science.gov (United States)

    Sherikar, Baburao N.; Umarji, A. M.

    Nano ceramic Diopside (CaMgSi2O6) powders are synthesized by Solution Combustion Process(SCS) using Calcium nitrate, Magnesium nitrate as oxidizer and glycine as fuel, fumed silica as silica source. Ammonium nitrate (AN) is used as extra oxidizer. Effect of AN on Diopside phase formation is investigated. The adiabatic flame temperatures are calculated theoretically for varying amount of AN according to thermodynamic concept and correlated with the observed flame temperatures. A “Multi channel thermocouple setup connected to computer interfaced Keithley multi voltmeter 2700” is used to monitor the thermal events during the process. An interpretation based on maximum combustion temperature and the amount of gases produced during reaction for various AN compositions has been proposed for the nature of combustion and its correlation with the characteristics of as synthesized powder. These powders are characterized by XRD, SEM showing that the powders are composed of polycrystalline oxides with crystallite size of 58nm to 74nm.

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

    International Nuclear Information System (INIS)

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

    2006-01-01

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

  20. Rework of process effluents from the fabrication of HTR fuel

    International Nuclear Information System (INIS)

    Lasberg, Ingo; Braehler, Georg; Boyes, David

    2008-01-01

    HTR fuel facilities require the application of several liquid chemicals and accordingly they produce significant amounts of Uranium contaminated/potentially contaminated effluents. The main effluents are (amounts for a 3 t Uranium/a plant): aqueous solutions including tetrahydrofurfuryl alcohol THFA, ammonium hydroxide NH4OH, and ammonium nitrate NH4NO3 (180 m 3 /a), isopropanol IPA/water mixtures (130 m 3 /a); Non-Process Water NPW (300 m 3 /a); methanol (7m 3 /a); additionally off-gas streams, containing ammonia (9 t/a) have to be treated. In an industrial scale facility all such effluents/gases need to be processed for recycling, decontamination prior to release to the environment (as waste or as valuable material). Thermal decomposition is applied to dispose of burnable residues.

  1. Manufacturing process for the metal ceramic hybrid fuel cladding tube

    International Nuclear Information System (INIS)

    Jung, Yang Il; Kim, Sun Han; Park, Jeong Yong

    2012-01-01

    For application in LWRs with suppressed hydrogen release, a metal-ceramic hybrid cladding tube has been proposed. The cladding consists of an inner zirconium tube and outer SiC fiber matrix SiC ceramic composite. The inner zirconium allows the matrix to remain fully sealed even if the ceramic matrix cracks through. The outer SiC composite can increase the safety margin by taking the merits of the SiC itself. However, it is a challenging task to fabricate the metal-ceramic hybrid tube. Processes such as filament winding, matrix impregnation, and surface costing are additionally required for the existing Zr based fuel cladding tubes. In the current paper, the development of the manufacturing process will be introduced

  2. Liquid fuels from biomass via a hydrothermal process

    Energy Technology Data Exchange (ETDEWEB)

    Goudriaan, F.; Peferoen, D.G.R. (Koninklijke Shell, Amsterdam (Netherlands). Lab.)

    1990-01-01

    Preliminary process studies on the conversion of various biomass types into liquid fuels have indicated that HydroThermal Upgrading (HTU) is more attractive than pyrolysis or gasification. In HTU the biomass is treated at temperatures of 300-350{sup 0}C in the presence of liquid water for 5-15 min. A large proportion of the oxygen is removed as carbon dioxide. In a case study a process for the production of 3600 t/d hydrocarbons starting from wood is evaluated. Six HTU units convert wood into ''biocrude'' containing 10 %w oxygen. The biocrude is upgraded by catalytic hydrodeoxygenation in a central facility. The final products are kerosine and gas oil which may be expected to have excellent properties. The manufacturing cost is 400-450 $/t. (author).

  3. Processing biogas to obtain motor fuel - Operational experience

    International Nuclear Information System (INIS)

    Seifert, M.

    2008-01-01

    This article takes a look at how raw biogas can be processed in order to remove carbon dioxide and corrosive substances and thus bring it up to natural gas quality. The ecological advantages of using biogas as a fuel are discussed and the situation in Europe and Switzerland is examined. Also, feeding biogas into the normal natural gas mains is discussed and the technologies necessary for the cleaning and preparation of the biogas are described. These include absorption and adsorption processes as well as membrane systems that are used to remove excessive carbon dioxide. The costs involved are discussed on the basis of experience gained in Sweden and Switzerland. Finally, the environmental aspects of methane losses are discussed.

  4. Manufacturing process for the metal ceramic hybrid fuel cladding tube

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Yang Il; Kim, Sun Han; Park, Jeong Yong [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2012-10-15

    For application in LWRs with suppressed hydrogen release, a metal-ceramic hybrid cladding tube has been proposed. The cladding consists of an inner zirconium tube and outer SiC fiber matrix SiC ceramic composite. The inner zirconium allows the matrix to remain fully sealed even if the ceramic matrix cracks through. The outer SiC composite can increase the safety margin by taking the merits of the SiC itself. However, it is a challenging task to fabricate the metal-ceramic hybrid tube. Processes such as filament winding, matrix impregnation, and surface costing are additionally required for the existing Zr based fuel cladding tubes. In the current paper, the development of the manufacturing process will be introduced.

  5. Process for the production of fuel combined articles for addition in block shaped high temperature fuel elements

    International Nuclear Information System (INIS)

    Hrovat, M.; Rachor, L.

    1976-01-01

    There is provided a process for the production of fuel compacts consisting of an isotropic, radiation-resistant graphite matrix of good heat conductivity having embedded therein coated fuel and/or fertile particles for insertion into high temperature fuel elements by providing the coated fuel and/or fertile particles with an overcoat of molding mixture consisting of graphite powder and a thermoplastic resin binder. The particles after the overcoating are provided with hardener and lubricant only on the surface and subsequently are compressed in a die heated to a constant temperature of about 150 0 C, hardened and discharged therefrom as finished compacts

  6. A study on recovery of uranium in the anode basket residues delivered from the pyrochemical process of used nuclear fuel

    Science.gov (United States)

    Eun, H. C.; Kim, T. J.; Jang, J. H.; Kim, G. Y.; Park, S. B.; Yoon, D. S.; Kim, S. H.; Paek, S. W.; Lee, S. J.

    2018-04-01

    In this study, the chlorination of uranium oxide (UO2) using ammonium chloride and zirconium as chemical agents was conducted to recover the uranium in the anode basket residues from the pyrochemical process of used nuclear fuel. The chlorination of UO2 was predicted using thermodynamic equilibrium calculations. The experimental conditions for the chlorination were determined using a chlorination test with cerium oxide (CeO2). In the chlorination test, it was confirmed that UO2 was chlorinated into UCl3 at 320 °C, some UO2 remained without changes in the chemical form, and ZrO2, Zr2O, and ZrCl2 were generated as byproducts.

  7. Report of Post Irradiation Examination for Dry Process Fuel

    International Nuclear Information System (INIS)

    Par, Jang Jin; Jung, I. H.; Kang, K. H.; Moon, J. S.; Lee, C. R.; Ryu, H. J.; Song, K. C.; Yang, M. S.; Yoo, B. O.; Jung, Y. H.; Choo, Y. S.

    2006-08-01

    The spent PWR fuel typically contains 0.9 wt.% of fissile uranium and 0.6 wt.% of fissile plutonium, which exceeds the natural uranium fissile content of 0.711 wt.%. The neutron economy of a CANDU reactor is sufficient to utilize the DUPIC fuel, even though the neutron-absorbing fission products contained in the spent PWR fuel were remained in the DUPIC fuel. The DUPIC fuel cycle offers advantages to the countries operating both the PWR and CANDU reactors, such as saving the natural uranium, reducing the spent fuel in both PWR and CANDU, and acquiring the extra energy by reuse of the PWR spent fuel. This report contains the results of post-irradiation examination of the DUPIC fuel irradiated four times at HANARO from May 2000 to August 2006 present except the first irradiation test of simulated DUPIC fuel at HANARO on August 1999

  8. Characteristics of Air Entrainment in Hydraulic Jump

    Science.gov (United States)

    Albarkani, M. S. S.; Tan, L. W.; Al-Gheethi, A.

    2018-04-01

    The characteristics of hydraulic jump, especially the air entrainment within jump is still not properly understood. Therefore, the current work aimed to determine the size and number of air entrainment formed in hydraulic jump at three different Froude numbers and to obtain the relationship between Froude number with the size and number of air entrainment in hydraulic jump. Experiments of hydraulic jump were conducted in a 10 m long and 0.3 m wide Armfield S6MKII glass-sided tilting flume. Hydraulic jumps were produced by flow under sluice gate with varying Froude number. The air entrainment of the hydraulic jump was captured with a Canon Power Shot SX40 HS digital camera in video format at 24 frames per second. Three discharges have been considered, i.e. 0.010 m3/s, 0.011 m3/s, and 0.013 m3/s. For hydraulic jump formed in each discharge, 32 frames were selected for the purpose of analysing the size and number of air entrainment in hydraulic jump. The results revealed that that there is a tendency to have greater range in sizes of air bubbles as Fr1 increases. Experiments with Fr1 = 7.547. 7.707, and 7.924 shown that the number of air bubbles increases exponentially with Fr1 at a relationship of N = 1.3814 e 0.9795Fr1.

  9. (La, Pr)0.8Sr0.2FeO3-δ-Sm 0.2Ce0.8O2-δ composite cathode for proton-conducting solid oxide fuel cells

    KAUST Repository

    Chen, Yonghong

    2014-08-01

    Mixed rare-earth (La, Pr)0.8Sr0.2FeO 3-δ-Sm0.2Ce0.8O2-δ (LPSF-SDC) composite cathode was investigated for proton-conducting solid oxide fuel cells based on protonic BaZr0.1Ce0.7Y 0.2O3-δ (BZCY) electrolyte. The powders of La 0.8-xPrxSr0.2FeO3-δ (x = 0, 0.2, 0.4, 0.6), Sm0.2Ce0.8O2-δ (SDC) and BaZr0.1Ce0.7Y0.2O3-δ (BZCY) were synthesized by a citric acid-nitrates self-propagating combustion method. The XRD results indicate that La0.8-xPrxSr 0.2FeO3-δ samples calcined at 950 °C exhibit perovskite structure and there are no interactions between LPSF0.2 and SDC at 1100 °C. The average thermal expansion coefficient (TEC) of LPSF0.2-SDC, BZCY and NiO-BZCY is 12.50 × 10-6 K-1, 13.51 × 10-6 K-1 and 13.47 × 10-6 K -1, respectively, which can provide good thermal compatibility between electrodes and electrolyte. An anode-supported single cell of NiO-BZCY|BZCY|LPSF0.2-SDC was successfully fabricated and operated from 700 °C to 550 °C with humidified hydrogen (∼3% H2O) as fuel and the static air as oxidant. A high maximum power density of 488 mW cm -2, an open-circuit potential of 0.95 V, and a low electrode polarization resistance of 0.071 Ω cm2 were achieved at 700 °C. Preliminary results demonstrate that LPSF0.2-SDC composite is a promising cathode material for proton-conducting solid oxide fuel cells. © 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

  10. Reduction of Pt{sup 2+} species in model Pt–CeO{sub 2} fuel cell catalysts upon reaction with methanol

    Energy Technology Data Exchange (ETDEWEB)

    Neitzel, Armin [Lehrstuhl für Physikalische Chemie II, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstrasse 3, 91058 Erlangen (Germany); Johánek, Viktor [Charles University, Faculty of Mathematics and Physics, Department of Surface and Plasma Science, V Holešovičkách 2, 18000 Prague (Czech Republic); Lykhach, Yaroslava, E-mail: yaroslava.lykhach@fau.de [Lehrstuhl für Physikalische Chemie II, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstrasse 3, 91058 Erlangen (Germany); Skála, Tomáš; Tsud, Nataliya; Vorokhta, Mykhailo; Matolín, Vladimír [Charles University, Faculty of Mathematics and Physics, Department of Surface and Plasma Science, V Holešovičkách 2, 18000 Prague (Czech Republic); Libuda, Jörg [Lehrstuhl für Physikalische Chemie II, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstrasse 3, 91058 Erlangen (Germany); Erlangen Catalysis Resource Center, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstrasse 3, 91058 Erlangen (Germany)

    2016-11-30

    Highlights: • Pt{sup 2+} species are reduced upon reaction with methanol. • Reduction of one Pt{sup 2+} requires presence of two oxygen vacancies. • Reduction of Pt{sup 2+} species leads to formation of ultra-small Pt particles. • Ultra-small Pt particles (around 25 atoms or less) are resistant to sintering. - Abstract: The stability of atomically dispersed Pt{sup 2+} species on the surface of nanostructured CeO{sub 2} films during the reaction with methanol has been investigated by means of synchrotron radiation photoelectron spectroscopy and resonant photoemission spectroscopy. The isolated Pt{sup 2+} species were prepared at low Pt concentration in Pt–CeO{sub 2} film. Additionally, Pt{sup 2+} species coexisting with metallic Pt particles were prepared at high Pt concentration. We found that adsorption of methanol yields similar decomposition products regardless of Pt concentration in Pt–CeO{sub 2} films. A small number of oxygen vacancies formed during the methanol decomposition can be replenished in the Pt–CeO{sub 2} film with low Pt concentration by diffusion of oxygen from the bulk. In the presence of supported Pt particles, a higher number of oxygen vacancies leads to a partial reduction of the Pt{sup 2+} species. The isolated Pt{sup 2+} species are reduced under rather strongly reducing conditions only, i.e. during annealing under continuous exposure to methanol. Reduction of isolated Pt{sup 2+} species results in the formation of ultra-small Pt particles containing around 25 atoms per particle or less. Such ultra-small Pt particles demonstrate excellent stability against sintering during annealing of Pt–CeO{sub 2} film with low Pt concentration under reducing conditions.

  11. Underwater Nuclear Fuel Disassembly and Rod Storage Process and Equipment Description. Volume II

    International Nuclear Information System (INIS)

    Viebrock, J.M.

    1981-09-01

    The process, equipment, and the demonstration of the Underwater Nuclear Fuel Disassembly and Rod Storage System are presented. The process was shown to be a viable means of increasing spent fuel pool storage density by taking apart fuel assemblies and storing the fuel rods in a denser fashion than in the original storage racks. The assembly's nonfuel-bearing waste is compacted and containerized. The report documents design criteria and analysis, fabrication, demonstration program results, and proposed enhancements to the system

  12. A CFD Investigation on the Effect of the Air Entrainment in Breaking Wave Impacts on a Mono-Pile

    DEFF Research Database (Denmark)

    Tomaselli, Pietro; Christensen, Erik Damgaard

    2017-01-01

    In impacts of breaking waves on offshore structures, it is still not well-known how the air entrainment phenomenon affects the exerted loads. In this paper, a developed CFD solver capable of simulating the air entrainment process was employed to repro-duce an experimental investigation on the imp......In impacts of breaking waves on offshore structures, it is still not well-known how the air entrainment phenomenon affects the exerted loads. In this paper, a developed CFD solver capable of simulating the air entrainment process was employed to repro-duce an experimental investigation...... on the impact of a spilling wave against a circular cylinder. The exerted in-line force was computed with and without the inclusion of dispersed bubbles. Results showed that the magnitude of the computed force was affected when the entrainment of bubbles was simulated....

  13. Fuel decontamination at Ringhals 1 with the new decontamination process IcedecTM

    International Nuclear Information System (INIS)

    Fredriksson, E.; Ivars, R.; Rosengren, A.; Granath, G.

    2003-01-01

    The new fuel decontamination technique ICEDEC TM , which has been developed by Westinghouse, is based on abrasion of fuel crud with ice particles. A mixture of ice and water is led continuously through the fuel assembly, which is placed in a specially designed fuel decontamination container connected to a closed loop recirculation system. The ice particles scrape off the loose crud from the fuel surfaces and a mixture of crud and water from the melted ice is then led to a filter unit were the crud is separated from the water. In this paper results of fuel decontamination tests of two-year-old and spent fuel assemblies during spring 2001 at Ringhals 1 are presented. The fuel crud was only released when ice particles passed through the fuel assembly and stopped within ten seconds after the feeding of ice particles had ceased. The activity release from the fuel could thus be performed in a controlled way making the process easy to manage and survey. Activity measurements confirmed that about 50% of the loose crud was removed from the fuel surfaces of the two-year-old assembly. Fuel inspection after the decontamination process showed no influence on the fuel integrity. Furthermore, no enhanced personnel radiation dose was involved with the fuel decontamination compared to normal fuel services. (authors)

  14. Fuel distribution process risk analysis in East Borneo

    Directory of Open Access Journals (Sweden)

    Laksmita Raizsa

    2018-01-01

    Full Text Available Fuel distribution is an important aspect of fulfilling the customer’s need. It is risky because it can cause tardiness that can cause fuel scarcity. In the process of distribution, many risks are occurring. House of Risk is a method used for mitigating the risk. It identifies seven risk events and nine risk agents. Matrix occurrence and severity are used for eliminating the minor impact risk. House of Risk 1 is used for determining the Aggregate Risk Potential (ARP. Pareto diagram is applied to prioritize risk that must be mitigated by preventive actions based on ARP. It identifies 4 priority risks, namely A8 (Car trouble, A4 (Human Error, A3 (Error deposit via bank and underpayment, and A6 (traffic accident which should be mitigated. House of Risk 2 makes for mapping between the preventive action and risk agent. It gets the Effectiveness to Difficulty Ratio (ETD for mitigating action. Conducting safety talk routine once every three days with ETD 2088 is the primary preventive actions.

  15. Understanding Kelvin-Helmholtz instability in paraffin-based hybrid rocket fuels

    Science.gov (United States)

    Petrarolo, Anna; Kobald, Mario; Schlechtriem, Stefan

    2018-04-01

    Liquefying fuels show higher regression rates than the classical polymeric ones. They are able to form, along their burning surface, a low viscosity and surface tension liquid layer, which can become unstable (Kelvin-Helmholtz instability) due to the high velocity gas flow in the fuel port. This causes entrainment of liquid droplets from the fuel surface into the oxidizer gas flow. To better understand the droplets entrainment mechanism, optical investigations on the combustion behaviour of paraffin-based hybrid rocket fuels in combination with gaseous oxygen have been conducted in the framework of this research. Combustion tests were performed in a 2D single-slab burner at atmospheric conditions. High speed videos were recorded and analysed with two decomposition techniques. Proper orthogonal decomposition (POD) and independent component analysis (ICA) were applied to the scalar field of the flame luminosity. The most excited frequencies and wavelengths of the wave-like structures characterizing the liquid melt layer were computed. The fuel slab viscosity and the oxidizer mass flow were varied to study their influence on the liquid layer instability process. The combustion is dominated by periodic, wave-like structures for all the analysed fuels. Frequencies and wavelengths characterizing the liquid melt layer depend on the fuel viscosity and oxidizer mass flow. Moreover, for very low mass flows, no wavelength peaks are detected for the higher viscosity fuels. This is important to better understand and predict the onset and development of the entrainment process, which is connected to the amplification of the longitudinal waves.

  16. Electrochemical processing of spent nuclear fuels: An overview of oxide reduction in pyroprocessing technology

    Directory of Open Access Journals (Sweden)

    Eun-Young Choi

    2015-12-01

    Full Text Available The electrochemical reduction process has been used to reduce spent oxide fuel to a metallic form using pyroprocessing technology for a closed fuel cycle in combination with a metal-fuel fast reactor. In the electrochemical reduction process, oxides fuels are loaded at the cathode basket in molten Li2O–LiCl salt and electrochemically reduced to the metal form. Various approaches based on thermodynamic calculations and experimental studies have been used to understand the electrode reaction and efficiently treat spent fuels. The factors that affect the speed of the electrochemical reduction have been determined to optimize the process and scale-up the electrolysis cell. In addition, demonstrations of the integrated series of processes (electrorefining and salt distillation with the electrochemical reduction have been conducted to realize the oxide fuel cycle. This overview provides insight into the current status of and issues related to the electrochemical processing of spent nuclear fuels.

  17. Process for dehydration of oregano using propane gas as fuel

    Directory of Open Access Journals (Sweden)

    Carlos O. Velásquez-Santos

    2014-08-01

    Full Text Available The article describes two important issues, the first is the process to design, implement and validate a mechanical dryer of oregano, using propane gas as fuel, and the second is the cost of the process of dehydrated, taking into account the cost of electric energy consumption by the fan and the cost of propane gas consumption by the heat exchanger. To achieve this, it was necessary review the state of the art and the study of the raw material (oregano, were established as premises of design the necessary technical specifications and the variables involved in the process, using conceptual methods and simulation to ensure that it complies with the ISO standard 7925:1999, which defines the requirements for the marketing of dried oregano and processed. Emphasis was made on the percentage of moisture that is 10%, the moisture of the product was found by the azeotropic distillation method, subsequently was validated the functionality and efficiency, comparing the results from an experimental design, then it was obtained the drying curve of oregano with the prototype of drying and it was checked if it meets ISO 7925:1999 standard and the NTC 4423 standard in order to obtain a final product dehydrated with the percentage of humidity appropriate.

  18. Stable, easily sintered BaCe{sub 0.5}Zr{sub 0.3}Y{sub 0.16}Zn{sub 0.04}O{sub 3-{delta}} electrolyte-based proton-conducting solid oxide fuel cells by gel-casting and suspension spray

    Energy Technology Data Exchange (ETDEWEB)

    Lin Bin; Dong Yingchao; Wang Songlin; Fang Daru; Ding Hanping; Zhang Xiaozhen; Liu Xingqin [Department of Materials Science and Engineering, University of Science and Technology of China (USTC), Hefei, Anhui 230026 (China); Meng Guangyao [Department of Materials Science and Engineering, University of Science and Technology of China (USTC), Hefei, Anhui 230026 (China)], E-mail: bin@mail.ustc.edu.cn

    2009-06-10

    Protonic ceramic membrane fuel cells (PCMFCs) based on oxide proton conductors exhibit more advantages than traditional solid oxide fuel cells (SOFCs) based on oxygen-ion conducting electrolytes, such as low activation energy and high energy efficiency. In order to develop a simple and cost-effective route to fabricate PCMFCs with SrCo{sub 0.9}Sb{sub 0.1}O{sub 3-{delta}} (SCS) cubic perovskite cathode, a dense BaCe{sub 0.5}Zr{sub 0.3}Y{sub 0.16}Zn{sub 0.04}O{sub 3-{delta}} (BCZYZn) electrolyte was fabricated in situ metal oxide on a porous anode support by gel-casting and suspension spray, which is cost-effective, easy to realize, and suitable for mass-production. The key part of this process is to directly spray well-mixed suspension of BaCO{sub 3}, CeO{sub 2}, ZrO{sub 2}, Y{sub 2}O{sub 3} and ZnO instead of pre-synthesized BCZYZn ceramic powder on the anode substrate. With SCS cubic perovskite cathode synthesized by gel-casting on the bi-layer, single cells were assembled and tested with H{sub 2} as fuel and the static air as oxidant. An open-circuit potential of 0.987 V, a maximum power density of 364 mW cm{sup -2}, and a low polarization resistance of the electrodes of 0.07 {omega} cm{sup 2} was achieved at 700 deg. C.

  19. Emission of pollutants from the combustion of composite fuels by metallurgical processes

    Directory of Open Access Journals (Sweden)

    J. Łabaj

    2015-10-01

    Full Text Available This paper presents the results of the study on emission characteristics of pollutants resulting from combustion process of composite alternative fuels for use in the processes of pyrometallurgy of copper as an alternative fuel to currently used coke breeze. These fuels are mainly based on waste carrier of “C” element, and the composition of the fuel is modelled in order to obtain the appropriate energy and emission parameters as well as strength parameters. These studies confirmed the possibility of using composite fuels as an alternative reducing agent as well as an energy carrier in the processes of pyrometallurgy of copper.

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

    International Nuclear Information System (INIS)

    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

  1. A proposed pyrometallurgical process for rapid recycle of discharged fuel materials from the Integral Fast Reactor

    International Nuclear Information System (INIS)

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

    1984-01-01

    The 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

  2. Supercritical Fluids Processing of Biomass to Chemicals and Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Olson, Norman K. [Iowa State Univ., Ames, IA (United States)

    2011-09-28

    The main objective of this project is to develop and/or enhance cost-effective methodologies for converting biomass into a wide variety of chemicals, fuels, and products using supercritical fluids. Supercritical fluids will be used both to perform reactions of biomass to chemicals and products as well as to perform extractions/separations of bio-based chemicals from non-homogeneous mixtures. This work supports the Biomass Program’s Thermochemical Platform Goals. Supercritical fluids are a thermochemical approach to processing biomass that, while aligned with the Biomass Program’s interests in gasification and pyrolysis, offer the potential for more precise and controllable reactions. Indeed, the literature with respect to the use of water as a supercritical fluid frequently refers to “supercritical water gasification” or “supercritical water pyrolysis.”

  3. Castor and Pollux - shielded cells for studying fuel treatment processes

    International Nuclear Information System (INIS)

    Faudot, G.; Bathellier, A.

    1969-01-01

    CASTOR and POLLUX, two alpha, beta, gamma cells are described in the present paper. They are located in the CEN at Fontenay-aux-Roses (France). They are designed for improvement studies of the various aqueous separation processes used in irradiated fuels reprocessing plants. Located in the same air-tight steel encasement, they arc inter-connected by a pneumatic transfer. These two cells have a similar in-line conception and they include: a gamma shielding in lead of 10 cm of thickness; an inner air-tight box, made with stainless steel and plexiglas, is maintained in lowering in comparison to room pressure. Eleven Hobson model seven master-slave manipulators allow inner manipulations. Then the inner equipment is described briefly. (author) [fr

  4. Environmental assessment for radioisotope heat source fuel processing and fabrication

    International Nuclear Information System (INIS)

    1991-07-01

    DOE has prepared an Environmental Assessment (EA) for radioisotope heat source fuel processing and fabrication involving existing facilities at the Savannah River Site (SRS) near Aiken, South Carolina and the Los Alamos National Laboratory (LANL) near Los Alamos, New Mexico. The proposed action is needed to provide Radioisotope Thermoelectric Generators (RTG) to support the National Aeronautics and Space Administration's (NASA) CRAF and Cassini Missions. Based on the analysis in the EA, DOE has determined that the proposed action does not constitute a major Federal action significantly affecting the quality of the human environment within the meaning of the National Environmental Policy Act (NEPA) of 1969. Therefore, an Environmental Impact Statement is not required. 30 refs., 5 figs

  5. Entrainment, transport and deposition of sediment by saline gravity currents

    Science.gov (United States)

    Zordan, Jessica; Juez, Carmelo; Schleiss, Anton J.; Franca, Mário J.

    2018-05-01

    Few studies have addressed simultaneously the feedback between the hydrodynamics of a gravity current and the geomorphological changes of a mobile bed. Hydrodynamic quantities such as turbulent and mean velocities, bed shear stress and turbulent stresses undoubtedly govern the processes of entrainment, transport and deposition. On the other hand, the incorporation of entrained sediment in the current may change its momentum by introducing extra internal stresses, introducing thus a feedback process. These two main questions are here investigated. Laboratory experiments of saline gravity currents, produced by lock-exchange, flowing over a mobile bed channel reach, are here reported. Different initial buoyancies of the current in the lock are tested together with three different grain sizes of the non-coherent sediment that form the erodible bed. Results from velocity measurements are combined with the visualization of the sediment movement in the mobile reach and with post-test topographic and photo surveys of the geomorphology modifications of the channel bed. Mean and turbulent velocities are measured and bed shear stress and Reynolds stresses are estimated. We show that the mean vertical component of the velocity and bed shear stress are highly correlated with the first instants of sediment entrainment. Vertical turbulent velocity is similarly related to entrainment, although with lower correlation values, contributing as well to the sediment movement. Bed shear stress and Reynolds shear stress measured near the bed are correlated with sediment entrainment for longer periods, indicating that these quantities are associated to distal transport as well. Geomorphological changes in the mobile bed are strongly related to the impulse caused by the bed shear stress on the sediment. On the other hand, we show that the nature of the grain of the mobile bed reach influences the hydrodynamics of the current which means that a feedback mechanisms between both occurs during

  6. Neural entrainment to rhythmically-presented auditory, visual and audio-visual speech in children

    Directory of Open Access Journals (Sweden)

    Alan James Power

    2012-07-01

    Full Text Available Auditory cortical oscillations have been proposed to play an important role in speech perception. It is suggested that the brain may take temporal ‘samples’ of information from the speech stream at different rates, phase-resetting ongoing oscillations so that they are aligned with similar frequency bands in the input (‘phase locking’. Information from these frequency bands is then bound together for speech perception. To date, there are no explorations of neural phase-locking and entrainment to speech input in children. However, it is clear from studies of language acquisition that infants use both visual speech information and auditory speech information in learning. In order to study neural entrainment to speech in typically-developing children, we use a rhythmic entrainment paradigm (underlying 2 Hz or delta rate based on repetition of the syllable ba, presented in either the auditory modality alone, the visual modality alone, or as auditory-visual speech (via a talking head. To ensure attention to the task, children aged 13 years were asked to press a button as fast as possible when the ba stimulus violated the rhythm for each stream type. Rhythmic violation depended on delaying the occurrence of a ba in the isochronous stream. Neural entrainment was demonstrated for all stream types, and individual differences in standardized measures of language processing were related to auditory entrainment at the theta rate. Further, there was significant modulation of the preferred phase of auditory entrainment in the theta band when visual speech cues were present, indicating cross-modal phase resetting. The rhythmic entrainment paradigm developed here offers a method for exploring individual differences in oscillatory phase locking during development. In particular, a method for assessing neural entrainment and cross-modal phase resetting would be useful for exploring developmental learning difficulties thought to involve temporal sampling

  7. Additive effect of Ce, Mo and K to nickel-cobalt aluminate supported solid oxide fuel cell for direct internal reforming of methane

    International Nuclear Information System (INIS)

    Kwak, Bu Ho; Park, Jungdeok; Yoon, Heechul; Kim, Hyeon Hui; Kim, Lim; Chung, Jong Shik

    2014-01-01

    Direct internal reforming of methane (steam/carbon=0.031, 850 .deg. C) is tested using button cells of Ni-YSZ/YSZ/LSM in which the anode layer is supported either on Ni-YSZ or on Ni-CoAl 2 O 4 . The Ni-CoAl 2 O 4 supported cell shows little degradation with operating time, as a result of higher resistance against carbon deposition, whereas the Ni-YSZ supported cell deactivates quickly and suffers fracture in 50 h. Upon incorporation of additives such as K, Ce, or Mo into the Ni-CoAl 2 O 4 support, cells with 0.5 wt% CeO 2 exhibit the best stable performance as a result of reduced coke formation. Cells with 0.5 wt% Mo exhibit the lowest performance. Although no carbon deposit is detected in the cells with K 2 CO 3 additives, their performance is worse than that in the CeO 2 case, and, in constant-current mode, there is a sudden voltage drop to zero after a certain period of time; this time becomes shorter with increasing K content. The injection of potassium into the anode side facilitates the generation of OH - and CO 3 2- in the anode and promotes the diffusion of these ions to the cathode. Increased polarization resistance at the cathode and increased electrolyte resistance result in such a sudden failure

  8. Asymmetric diffusion of Zr, Sc and Ce, Gd at the interface between zirconia electrolyte and ceria interlayer for solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Bo, E-mail: Liangbo@gdut.edu.cn; Tao, Tao; Zhang, Silong; Huang, Yongan; Cai, Zhihong; Lu, Shenguo, E-mail: sglu@gdut.edu.cn

    2016-09-15

    The microstructures of cathode interlayer and elemental diffusion behaviors across the interfacial region (electrolyte/interlayer) have been characterized using high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD) and scanning TEM combined with energy dispersive X-ray spectroscopy (STEM-EDS). A densified film about 100 nm is locally formed at the interface of electrolyte/interlayer as the interlayer using dip-coating method and being sintered at 1200 °C. It is observed that the compositional distribution curves across the interface are asymmetric. More amount of the Zr, Sc component is detected in gadolinium-doped ceria (GDC) than that of the Ce, Gd component is detected in scandia-stabilized-zirconia (SSZ). XRD and EDS results show that the densified layer might consist of (Zr, Ce)O{sub 2}-based solid solution. The high open circuit voltage of the cell is related to the dense structure of electrolyte, while the increased activation energy in overpotential resistance is attributed to the porous structure of interlayer as well as the high resistance phases locally formed at its interface. - Highlights: • The (Ce−Zr)O{sub 2} based solid solution was locally formed at 1200 °C. • More Zr, Sc elements were detected in GDC than Ce, Gd elements in SSZ. • Zirconia nanodomain was embedded in GDC beside grain boundary. • High OCVs were achieved due to the highly dense electrolyte layer.

  9. Laser-based analytical monitoring in nuclear-fuel processing plants

    International Nuclear Information System (INIS)

    Hohimer, J.P.

    1978-09-01

    The use of laser-based analytical methods in nuclear-fuel processing plants is considered. The species and locations for accountability, process control, and effluent control measurements in the Coprocessing, Thorex, and reference Purex fuel processing operations are identified and the conventional analytical methods used for these measurements are summarized. The laser analytical methods based upon Raman, absorption, fluorescence, and nonlinear spectroscopy are reviewed and evaluated for their use in fuel processing plants. After a comparison of the capabilities of the laser-based and conventional analytical methods, the promising areas of application of the laser-based methods in fuel processing plants are identified

  10. Crud in the solvent extraction process for spent fuel reprocessing

    International Nuclear Information System (INIS)

    Chen Jing

    2004-01-01

    The crud occurred in Purex process is caused by the degradations of extractant and solvent and the existence of insoluble solid particle in the nuclear fuel reprocessing. The crud seriously affects the operation of the extraction column. The present paper reviews the study status on the crud in the Purex process. It is generally accepted that in the Purex process, particularly in the first cycle, the crud occurrence is related to the capillary chemistry phenomena resulting from the deposits of Zr with TBP degradation products HDBP, H 2 MBP, H 3 PO 4 and the insoluble particle RuO 2 and Pd. The occurrence of deposits and the type of crud are tightly related to the molar ratio of HDBP and Zr, and the aqueous pH. In addition, the effect of degradation products from the diluent, such as kerosene, is an unnegligible factor to cause the crud. The crud can be discharged from the extraction equipment with Na 2 CO 3 or oxalic acid. In the study on simulating the crud, the effects of the deposits of Zr with TBP degradation products HDBP, H 2 MBP and H 2 PO 4 , and the insoluble particle RuO 2 and Pd should be considered at the same time. (authors)

  11. Pyro-electrochemical reprocessing of irradiated MOX fast reactor fuel, testing of the reprocessing process with direct MOX fuel production

    Energy Technology Data Exchange (ETDEWEB)

    Kormilitzyn, M.V.; Vavilov, S.K.; Bychkov, A.V.; Skiba, O.V.; Chistyakov, V.M.; Tselichshev, I.V

    2000-07-01

    One of the advanced technologies for fast reactor fuel recycle is pyro-electrochemical molten salt technology. In 1998 we began to study the next phase of the irradiated oxide fuel reprocessing new process MOX {yields} MOX. This process involves the following steps: - Dissolution of irradiated fuel in molten alkaline metal chlorides, - Purification of melt from fission products that are co-deposited with uranium and plutonium oxides, - Electrochemical co-deposition of uranium and plutonium oxides under the controlled cathode potential, - Production of granulated MOX (crushing,salt separation and sizing), and - Purification of melt from fission products by phosphate precipitation. In 1998 a series of experiments were prepared and carried out in order to validate this process. It was shown that the proposed reprocessing flowsheet of irradiated MOX fuel verified the feasibility of its decontamination from most of its fission products (rare earths, cesium) and minor-actinides (americium, curium)

  12. Pyro-electrochemical reprocessing of irradiated MOX fast reactor fuel, testing of the reprocessing process with direct MOX fuel production

    International Nuclear Information System (INIS)

    Kormilitzyn, M.V.; Vavilov, S.K.; Bychkov, A.V.; Skiba, O.V.; Chistyakov, V.M.; Tselichshev, I.V.

    2000-01-01

    One of the advanced technologies for fast reactor fuel recycle is pyro-electrochemical molten salt technology. In 1998 we began to study the next phase of the irradiated oxide fuel reprocessing new process MOX → MOX. This process involves the following steps: - Dissolution of irradiated fuel in molten alkaline metal chlorides, - Purification of melt from fission products that are co-deposited with uranium and plutonium oxides, - Electrochemical co-deposition of uranium and plutonium oxides under the controlled cathode potential, - Production of granulated MOX (crushing,salt separation and sizing), and - Purification of melt from fission products by phosphate precipitation. In 1998 a series of experiments were prepared and carried out in order to validate this process. It was shown that the proposed reprocessing flowsheet of irradiated MOX fuel verified the feasibility of its decontamination from most of its fission products (rare earths, cesium) and minor-actinides (americium, curium)

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

    International Nuclear Information System (INIS)

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

    1978-01-01

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

  14. 40 CFR 80.1416 - Petition process for evaluation of new renewable fuels pathways.

    Science.gov (United States)

    2010-07-01

    ... renewable fuels pathways. 80.1416 Section 80.1416 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Petition process for evaluation of new renewable fuels pathways. (a) Pursuant to this section, a party may... fuel pathway has not been evaluated by EPA to determine if it qualifies for a D code pursuant to § 80...

  15. Control system design specification of advanced spent fuel management process units

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, S. H.; Kim, S. H.; Yoon, J. S

    2003-06-01

    In this study, the design specifications of instrumentation and control system for advanced spent fuel management process units are presented. The advanced spent fuel management process consists of several process units such as slitting device, dry pulverizing/mixing device, metallizer, etc. In this study, the control and operation characteristics of the advanced spent fuel management mockup process devices and the process devices developed in 2001 and 2002 are analysed. Also, a integral processing system of the unit process control signals is proposed, which the operation efficiency is improved. And a redundant PLC control system is constructed which the reliability is improved. A control scheme is proposed for the time delayed systems compensating the control performance degradation caused by time delay. The control system design specification is presented for the advanced spent fuel management process units. This design specifications can be effectively used for the detail design of the advanced spent fuel management process.

  16. Air entrainment by plunging water jets

    NARCIS (Netherlands)

    Van de Sande, E.

    1974-01-01

    Gas entrainment caused by the impact of liquid jets upon liquid pool surfaces is a subject which has received too little attention. This well-known phenomenon,which occurs In nature and in numerous industrial operations, has only recently received interest from scientific workers. The influence on

  17. Remote Handling Devices for Disposition of Enriched Uranium Reactor Fuel Using Melt-Dilute Process

    International Nuclear Information System (INIS)

    Heckendorn, F.M.

    2001-01-01

    Remote handling equipment is required to achieve the processing of highly radioactive, post reactor, fuel for the melt-dilute process, which will convert high enrichment uranium fuel elements into lower enrichment forms for subsequent disposal. The melt-dilute process combines highly radioactive enriched uranium fuel elements with deleted uranium and aluminum for inductive melting and inductive stirring steps that produce a stable aluminum/uranium ingot of low enrichment

  18. TRISO-coated spent fuel processing using a Grind-Leach head-end

    International Nuclear Information System (INIS)

    Spencer, Barry B.; Del Cul, Guillermo D.; Mattus, Catherine H.; Collins, Emory D.

    2005-01-01

    Processing of TRISO-coated HTGR fuels with the grind-leach process requires that the fuel be finely pulverized for efficient and effective acid dissolution of the fuel components. Mechanical size reduction of the fuel is being investigated with jet mill technology as the final milling step. Laboratory experiments were performed with surrogates of crushed fuel compacts that indicate that milling to very small particle sizes is feasible. The size distribution of the milled product is sensitive to the solids feed rate, and the distribution may be bimodal which could support an effective solid-solid separation. (author)

  19. Microstructure and properties of the novel Cu–0.30Mg–0.05Ce alloy processed by equal channel angular pressing

    International Nuclear Information System (INIS)

    Duan, Y.L.; Xu, G.F.; Tang, L.; Li, Z.; Yang, G.

    2015-01-01

    A novel Cu–0.30Mg–0.05Ce (wt%) alloy was designed and prepared by melting and casting. The hot-rolled Cu–Mg–Ce alloy with an average grain size of 24.3 μm was processed by equal channel angular pressing (ECAP) via route B_C with different passes at room temperature. Moreover, microstructure evolution, mechanical properties and electrical conductivity of the alloy subjected to ECAP with different passes have been analyzed. The transmission electron microscope observation and electron backscatter diffraction analysis results show that the grains were refined significantly and the low angle boundaries generated at the initial stage of deformation were gradually transformed to the high angle boundaries with increasing the number of ECAP passes. After 8 ECAP passes, the average grain size decreased to 1.2 μm, and the fraction of high angle boundaries was 87.7%. Besides, the typical FCC shear textures ({111} , {111} and {001} ) were generated during ECAP deformation. Furthermore, tension testing results indicated that the tensile strength was remarkably improved from ∼274 MPa before ECAP to ∼588 MPa after 8 ECAP passes, maintaining an appropriate elongation of ∼11% and good electrical conductivity of 73.5% International Annealed Copper Standard (IACS), which showed bright prospect in high-speed railway as a contact wire material.

  20. Microstructure and properties of the novel Cu–0.30Mg–0.05Ce alloy processed by equal channel angular pressing

    Energy Technology Data Exchange (ETDEWEB)

    Duan, Y.L. [School of Materials Science and Engineering, Central South University, Changsha 410083 (China); Xu, G.F., E-mail: csuxgf660302@csu.edu.cn [School of Materials Science and Engineering, Central South University, Changsha 410083 (China); Key Laboratory of Nonferrous Materials Science and Engineering of Ministry of Education, Central South University, Changsha 410083 (China); Tang, L. [School of Materials Science and Engineering, Central South University, Changsha 410083 (China); Li, Z. [School of Materials Science and Engineering, Central South University, Changsha 410083 (China); Key Laboratory of Nonferrous Materials Science and Engineering of Ministry of Education, Central South University, Changsha 410083 (China); Yang, G. [School of Materials Science and Engineering, Central South University, Changsha 410083 (China)

    2015-11-11

    A novel Cu–0.30Mg–0.05Ce (wt%) alloy was designed and prepared by melting and casting. The hot-rolled Cu–Mg–Ce alloy with an average grain size of 24.3 μm was processed by equal channel angular pressing (ECAP) via route B{sub C} with different passes at room temperature. Moreover, microstructure evolution, mechanical properties and electrical conductivity of the alloy subjected to ECAP with different passes have been analyzed. The transmission electron microscope observation and electron backscatter diffraction analysis results show that the grains were refined significantly and the low angle boundaries generated at the initial stage of deformation were gradually transformed to the high angle boundaries with increasing the number of ECAP passes. After 8 ECAP passes, the average grain size decreased to 1.2 μm, and the fraction of high angle boundaries was 87.7%. Besides, the typical FCC shear textures ({111}<112>, {111}<110> and {001}<110>) were generated during ECAP deformation. Furthermore, tension testing results indicated that the tensile strength was remarkably improved from ∼274 MPa before ECAP to ∼588 MPa after 8 ECAP passes, maintaining an appropriate elongation of ∼11% and good electrical conductivity of 73.5% International Annealed Copper Standard (IACS), which showed bright prospect in high-speed railway as a contact wire material.

  1. Spent Nuclear Fuel (SNF) Project Design Verification and Validation Process

    International Nuclear Information System (INIS)

    OLGUIN, L.J.

    2000-01-01

    This document provides a description of design verification and validation activities implemented by the Spent Nuclear Fuel (SNF) Project. During the execution of early design verification, a management assessment (Bergman, 1999) and external assessments on configuration management (Augustenburg, 1999) and testing (Loscoe, 2000) were conducted and identified potential uncertainties in the verification process. This led the SNF Chief Engineer to implement corrective actions to improve process and design products. This included Design Verification Reports (DVRs) for each subproject, validation assessments for testing, and verification of the safety function of systems and components identified in the Safety Equipment List to ensure that the design outputs were compliant with the SNF Technical Requirements. Although some activities are still in progress, the results of the DVR and associated validation assessments indicate that Project requirements for design verification are being effectively implemented. These results have been documented in subproject-specific technical documents (Table 2). Identified punch-list items are being dispositioned by the Project. As these remaining items are closed, the technical reports (Table 2) will be revised and reissued to document the results of this work

  2. Onset of liquid droplet entrainment on a direct vessel injection system for APR1400

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Han-sol; Lee, Jae-Young [Handong Global University, Pohang (Korea, Republic of); Kim, Jong-Rok; Euh, Dong-Jin [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-10-15

    In this research, a series of visualization works was conducted to understand droplet entrainment of the flow pattern generated in direct vessel injection system(DVI) of Korea nuclear power plant, APR 1400. In the emergency situation of a nuclear power plant, reliability of DVI cooling can be an important issue. It is known that, the amount and the rate of entrainment during the DVI cooling process can significantly affect the total heat removal. To visualize the film Reynolds number closely related with onset of droplet entrainment induced by falling film flow and lateral air flow in a small gap, confocal chromatic sensing method for measuring accurately film thickness and depth averaging particle image velocimetry for film velocity were used. The results have been post processed 4G Insight software. By measuring two dimensional film Reynolds number, we can predict the onset of droplet entrainment and obtain visible breakup region intuitively. To visualize the droplet entrainment induced by falling film flow and lateral air flow in a small gap, shadowgraph method with CCD camera (2200fps, 1280 pixel X 800 pixel, ) on coated plate with super water-repellent agent was used. The results have been post processed using 4G Insight software. By measuring two dimensional film Reynolds number, we can predict the onset of droplet entrainment and obtain visible breakup region intuitively. By adopting both super hydrophobic coating method and shadowgraph method, entrainment in a narrow gap was successfully visualized that has rarely performed before and meaningful results for DVI system research fields have been made.

  3. Onset of liquid droplet entrainment on a direct vessel injection system for APR1400

    International Nuclear Information System (INIS)

    Kim, Han-sol; Lee, Jae-Young; Kim, Jong-Rok; Euh, Dong-Jin

    2016-01-01

    In this research, a series of visualization works was conducted to understand droplet entrainment of the flow pattern generated in direct vessel injection system(DVI) of Korea nuclear power plant, APR 1400. In the emergency situation of a nuclear power plant, reliability of DVI cooling can be an important issue. It is known that, the amount and the rate of entrainment during the DVI cooling process can significantly affect the total heat removal. To visualize the film Reynolds number closely related with onset of droplet entrainment induced by falling film flow and lateral air flow in a small gap, confocal chromatic sensing method for measuring accurately film thickness and depth averaging particle image velocimetry for film velocity were used. The results have been post processed 4G Insight software. By measuring two dimensional film Reynolds number, we can predict the onset of droplet entrainment and obtain visible breakup region intuitively. To visualize the droplet entrainment induced by falling film flow and lateral air flow in a small gap, shadowgraph method with CCD camera (2200fps, 1280 pixel X 800 pixel, ) on coated plate with super water-repellent agent was used. The results have been post processed using 4G Insight software. By measuring two dimensional film Reynolds number, we can predict the onset of droplet entrainment and obtain visible breakup region intuitively. By adopting both super hydrophobic coating method and shadowgraph method, entrainment in a narrow gap was successfully visualized that has rarely performed before and meaningful results for DVI system research fields have been made

  4. Additive effect of Ce, Mo and K to nickel-cobalt aluminate supported solid oxide fuel cell for direct internal reforming of methane

    Energy Technology Data Exchange (ETDEWEB)

    Kwak, Bu Ho; Park, Jungdeok; Yoon, Heechul; Kim, Hyeon Hui; Kim, Lim; Chung, Jong Shik [POSTECH, Pohang (Korea, Republic of)

    2014-01-15

    Direct internal reforming of methane (steam/carbon=0.031, 850 .deg. C) is tested using button cells of Ni-YSZ/YSZ/LSM in which the anode layer is supported either on Ni-YSZ or on Ni-CoAl{sub 2}O{sub 4}. The Ni-CoAl{sub 2}O{sub 4} supported cell shows little degradation with operating time, as a result of higher resistance against carbon deposition, whereas the Ni-YSZ supported cell deactivates quickly and suffers fracture in 50 h. Upon incorporation of additives such as K, Ce, or Mo into the Ni-CoAl{sub 2}O{sub 4} support, cells with 0.5 wt% CeO{sub 2} exhibit the best stable performance as a result of reduced coke formation. Cells with 0.5 wt% Mo exhibit the lowest performance. Although no carbon deposit is detected in the cells with K{sub 2}CO{sub 3} additives, their performance is worse than that in the CeO{sub 2} case, and, in constant-current mode, there is a sudden voltage drop to zero after a certain period of time; this time becomes shorter with increasing K content. The injection of potassium into the anode side facilitates the generation of OH{sup -} and CO{sub 3}{sup 2-} in the anode and promotes the diffusion of these ions to the cathode. Increased polarization resistance at the cathode and increased electrolyte resistance result in such a sudden failure.

  5. The development of spent fuel storage process equipment

    International Nuclear Information System (INIS)

    Yoon, Wan Ki; Kim, Ho Dong; Kim, Ki Joon; Kim, Bum Hoe

    1992-02-01

    A nuclear material accounting system were designed to track the transitions of nuclear materials at the spent-fuel technology research facility. It is embedded in a distributed control system real-time structure of the system gives timely on-line accountancy. And performance of AC servo motor with fuzzy logic control and its applicability to spent fuel management were experimentally evaluated. (Author)

  6. Detailed modeling of common rail fuel injection process

    NARCIS (Netherlands)

    Seykens, X.L.J.; Somers, L.M.T.; Baert, R.S.G.

    2005-01-01

    Modeling of fuel injection equipment is a tool that is used increasingly for explaining or predicting the effect of advanced diesel injection strategies on combustion and emissions. This paper reports on the modeling of the high-pressure part of a research type Heavy Duty Common Rail (CR) fuel

  7. Spent fuel reprocessing system availability definition by process simulation

    International Nuclear Information System (INIS)

    Holder, N.; Haldy, B.B.; Jonzen, M.

    1978-05-01

    To examine nuclear fuel reprocessing plant operating parameters such as maintainability, reliability, availability, equipment redundancy, and surge storage requirements and their effect on plant throughput, a computer simulation model of integrated HTGR fuel reprocessing plant operations is being developed at General Atomic Company (GA). The simulation methodology and the status of the computer programming completed on reprocessing head end systems is reported

  8. Fuel Quality/Processing Study. Volume II. Appendix, Task I, literature survey

    Energy Technology Data Exchange (ETDEWEB)

    O' Hara, J B; Bela, A; Jentz, N E; Klumpe, H W; Kessler, R E; Kotzot, H T; Loran, B I

    1981-04-01

    This activity was begun with the assembly of information from Parsons' files and from contacts in the development and commercial fields. A further more extensive literature search was carried out using the Energy Data Base and the American Petroleum Institute Data Base. These are part of the DOE/RECON system. Approximately 6000 references and abstracts were obtained from the EDB search. These were reviewed and the especially pertinent documents, approximately 300, were acquired in the form of paper copy or microfiche. A Fuel Properties form was developed for listing information pertinent to gas turbine liquid fuel properties specifications. Fuel properties data for liquid fuels from selected synfuel processes, deemed to be successful candidates for near future commercial plants were tabulated on the forms. The processes selected consisted of H-Coal, SRC-II and Exxon Donor Solvent (EDS) coal liquefaction processes plus Paraho and Tosco shale oil processes. Fuel properties analyses for crude and distillate syncrude process products are contained in Section 2. Analyses representing synthetic fuels given refinery treatments, mostly bench scale hydrotreating, are contained in Section 3. Section 4 discusses gas turbine fuel specifications based on petroleum source fuels as developed by the major gas turbine manufacturers. Section 5 presents the on-site gas turbine fuel treatments applicable to petroleum base fuels impurities content in order to prevent adverse contaminant effects. Section 7 relates the environmental aspects of gas turbine fuel usage and combustion performance. It appears that the near future stationary industrial gas turbine fuel market will require that some of the synthetic fuels be refined to the point that they resemble petroleum based fuels.

  9. Fusion-Fission Hybrid for Fissile Fuel Production without Processing

    Energy Technology Data Exchange (ETDEWEB)

    Fratoni, M; Moir, R W; Kramer, K J; Latkowski, J F; Meier, W R; Powers, J J

    2012-01-02

    Two scenarios are typically envisioned for thorium fuel cycles: 'open' cycles based on irradiation of {sup 232}Th and fission of {sup 233}U in situ without reprocessing or 'closed' cycles based on irradiation of {sup 232}Th followed by reprocessing, and recycling of {sup 233}U either in situ or in critical fission reactors. This study evaluates a third option based on the possibility of breeding fissile material in a fusion-fission hybrid reactor and burning the same fuel in a critical reactor without any reprocessing or reconditioning. This fuel cycle requires the hybrid and the critical reactor to use the same fuel form. TRISO particles embedded in carbon pebbles were selected as the preferred form of fuel and an inertial laser fusion system featuring a subcritical blanket was combined with critical pebble bed reactors, either gas-cooled or liquid-salt-cooled. The hybrid reactor was modeled based on the earlier, hybrid version of the LLNL Laser Inertial Fusion Energy (LIFE1) system, whereas the critical reactors were modeled according to the Pebble Bed Modular Reactor (PBMR) and the Pebble Bed Advanced High Temperature Reactor (PB-AHTR) design. An extensive neutronic analysis was carried out for both the hybrid and the fission reactors in order to track the fuel composition at each stage of the fuel cycle and ultimately determine the plant support ratio, which has been defined as the ratio between the thermal power generated in fission reactors and the fusion power required to breed the fissile fuel burnt in these fission reactors. It was found that the maximum attainable plant support ratio for a thorium fuel cycle that employs neither enrichment nor reprocessing is about 2. This requires tuning the neutron energy towards high energy for breeding and towards thermal energy for burning. A high fuel loading in the pebbles allows a faster spectrum in the hybrid blanket; mixing dummy carbon pebbles with fuel pebbles enables a softer spectrum in

  10. Thermal imaging of solid oxide fuel cell anode processes

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-01-01

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

  11. Thermal imaging of solid oxide fuel cell anode processes

    Science.gov (United States)

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

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

  12. Development of recycling processes for clean rejected MOX fuel pellets

    International Nuclear Information System (INIS)

    Khot, P.M.; Singh, G.; Shelke, B.K.; Surendra, B.; Yadav, M.K.; Mishra, A.K.; Afzal, Mohd.; Panakkal, J.P.

    2014-01-01

    Highlights: • Dry and wet (MWDD) methods were developed for 100% recycling of CRO (0.4–44% PuO 2 ). • Dry method showed higher productivity and comparable powder/product characteristics. • MWDD batches demonstrated improved powder/product characteristics to that of virgin. • Second/multiple recycling is possible with MWDD with better powder/product characteristics. • MWDD batches prepared by little milling showed better macroscopic homogeneity to that of virgin. - Abstract: The dry and wet recycling processes have been developed for 100% recycling of Clean Reject Oxide (CRO) generated during the fabrication of MOX fuel, as CRO contains significant amount of plutonium. Plutonium being strategic material need to be circumvented from its proliferation issues related to its storage for long period. It was difficult to recycle CRO containing higher Pu content even with multiple oxidation and reduction steps. The mechanical recycling comprising of jaw crushing and sieving has been coupled with thermal pulverization for recycling CRO with higher Pu content in dry recycling technique. In wet recycling, MicroWave Direct Denitration (MWDD) technique has been developed for 100% recycling of CRO. The powder prepared by dry and wet (MWDD) recycling techniques was characterized by XRD and BET techniques and their effects on the pellets were evaluated. (U,21%Pu)O 2 pellets fabricated from virgin powder and MWDD were characterized using optical microscopy and α-autoradiography and the results obtained were compared

  13. Process and device for feeding a cutter of nuclear fuel

    International Nuclear Information System (INIS)

    Chaze, Gilbert; Cherel, Guy; Guilloteau, Rene; Tucoulat, Daniel.

    1975-01-01

    A process is described for feeding the cutter of a nuclear fuel tube bundle by means of a mobile magazine. The first operation consists in grabbing the bundle in the storage pool by means of handling gear incorporated in the cutter magazine and introducing the bundle right into the magazine. The second operation is to locate the position of the bundle and to do so a mobile reference plate, of which the relative positions in relation to the magazine and to the cutting section in the cutter are known, is placed near the end of the magazine that will enter into contact with the cutter, the bundle is then moved until its end enters into contact with the reference plate. The next operation consists in adjusting the position of the bundle by moving it out of the magazine by a given length as from the position of the bundle when it was in contact with the reference plate so as to separate the foot end of the bundle by a cut made right next to this foot end. In several successive operations to adjust the cutting positions, the bundle is fed forward in the cutter by a length equal to a tube section. All these operations are carried out without the bundle being separated from the single handling gear built into the magazine [fr

  14. Heterogeneous catalytic process for alcohol fuels from syngas

    Energy Technology Data Exchange (ETDEWEB)

    Minahan, D.M.; Nagaki, D.A.

    1995-12-31

    This project is focused on the discovery and evaluation of novel heterogeneous catalyst for the production of oxygenated fuel enhancers from synthesis gas. Catalysts have been studied and optimized for the production of methanol and isobutanol mixtures which may be used for the downstream synthesis of MTBE or related oxygenates. Higher alcohols synthesis (HAS) from syngas was studied; the alcohols that are produced in this process may be used for the downstream synthesis of MTBE or related oxygenates. This work has resulted in the discovery of a catalyst system that is highly selective for isobutanol compared with the prior art. The catalysts operate at high temperature (400{degrees}C), and consist of a spinel oxide support (general formula AB{sub 2}O{sub 4}, where A=M{sup 2+} and B = M{sup 3+}), promoted with various other elements. These catalysts operate by what is believed to be an aldol condensation mechanism, giving a product mix of mainly methanol and isobutanol. In this study, the effect of product feed/recycle (methanol, ethanol. n-propanol, isopropanol, carbon dioxide and water) on the performance of 10-DAN-55 (spinel oxide based catalyst) at 400{degrees}C, 1000 psi, GHSV = 12,000 and syngas (H{sub 2}/CO) ratio = 1:2 (alcohol addition) and 1:1 (carbon dioxide and water addition) was studied. The effect of operation at high temperatures and pressures on the performance of an improved catalyst formulation was also examined.

  15. Reduction of environmental pollution from fuel and target manufacturing processes

    International Nuclear Information System (INIS)

    Hardt, H.A.

    1976-10-01

    Nuclear fuel and target manufacturing processes in the 300 Area generate potential environmental pollutants. Efforts to eliminate or reduce their harmful effects have been pursued for many years by the Raw Materials and Raw Materials Technology departments with assistance from other groups, primarily the Project and Health Physics departments. This report documents: methods adopted to reduce pollution; cost of these methods; amount of pollution reduction achieved; and other benefits in cost savings or quality improvement for January 1968 through December 1975. Capital funds totaling $915,000 were spent on these programs. Annual cost savings of $65,000 were realized, and incidental but significant improvements in product quality were obtained. In no case was product quality degraded. Reductions in releases of pollutants are summarized for water pollution, air pollution, and land pollution. In addition to these reductions, intangible benefits were realized including reduced corrosion of structures and equipment; improved working conditions for personnel; energy savings, both on and offplant; improved utilization of natural resources; and reduced impact to environment, both on and offplant

  16. Tecnored process - high potential in using different kinds of solid fuels

    Directory of Open Access Journals (Sweden)

    José Henrique Noldin Júnior

    2005-12-01

    Full Text Available One important feature of the Brazilian Tecnored ironmaking process is its flexibility to use different types of solid fuels, other than metallurgical coke, as proved in the pilot plant tests by extensively using green petroleum coke, biomasses, high ash cokes, etc. Even if new solid fuels not thus far used are envisaged for a given project, thru the bench scale simulator of the process it is possible to predict the behavior of such solid fuels in the Tecnored furnace and establish the best techno-economical-environmental equation for its use. This paper discusses the key aspects involved in the use of alternative solid fuels in the Tecnored process.

  17. Research on solvent extraction process for reprocessing of Th-U fuel from HTGR

    International Nuclear Information System (INIS)

    Bao Borong; Wang Gaodong; Qian Jun

    1992-05-01

    The unique properties of spent fuel from HTGR (high temperature gas cooled reactor) have been analysed. The single solvent extraction process using 30% TBP for separation and purification of Th-U fuel has been studied. In addition, the solvent extraction process for second uranium purification is also investigated to meet different needs of reprocessing and reproduction of Th-U spent fuel from HTGR

  18. The main chemical safety problems in main process of nuclear fuel reprocessing plant

    International Nuclear Information System (INIS)

    Song Fengli; Zhao Shangui; Liu Xinhua; Zhang Chunlong; Lu Dan; Liu Yuntao; Yang Xiaowei; Wang Shijun

    2014-01-01

    There are many chemical reactions in the aqueous process of nuclear fuel reprocessing. The reaction conditions and the products are different so that the chemical safety problems are different. In the paper the chemical reactions in the aqueous process of nuclear fuel reprocessing are described and the main chemical safety problems are analyzed. The reference is offered to the design and accident analysis of the nuclear fuel reprocessing plant. (authors)

  19. Historic American Engineering Record, Idaho National Laboratory, Idaho Chemical Processing Plant, Fuel Reprocessing Complex

    Energy Technology Data Exchange (ETDEWEB)

    Susan Stacy; Julie Braun

    2006-12-01

    Just as automobiles need fuel to operate, so do nuclear reactors. When fossil fuels such as gasoline are burned to power an automobile, they are consumed immediately and nearly completely in the process. When the fuel is gone, energy production stops. Nuclear reactors are incapable of achieving this near complete burn-up because as the fuel (uranium) that powers them is burned through the process of nuclear fission, a variety of other elements are also created and become intimately associated with the uranium. Because they absorb neutrons, which energize the fission process, these accumulating fission products eventually poison the fuel by stopping the production of energy from it. The fission products may also damage the structural integrity of the fuel elements. Even though the uranium fuel is still present, sometimes in significant quantities, it is unburnable and will not power a reactor unless it is separated from the neutron-absorbing fission products by a method called fuel reprocessing. Construction of the Fuel Reprocessing Complex at the Chem Plant started in 1950 with the Bechtel Corporation serving as construction contractor and American Cyanamid Company as operating contractor. Although the Foster Wheeler Corporation assumed responsibility for the detailed working design of the overall plant, scientists at Oak Ridge designed all of the equipment that would be employed in the uranium separations process. After three years of construction activity and extensive testing, the plant was ready to handle its first load of irradiated fuel.

  20. Permission of the alteration in nuclear fuel material processing business in the Kumatori Works of Nuclear Fuel Industries, Ltd. (report)

    International Nuclear Information System (INIS)

    1982-01-01

    A report by the Nuclear Safety Commission to the Prime Minister concerning the permission of the alteration in nuclear fuel material processing business in the Kumatori Works, Nuclear Fuel Industries Ltd., was presented. The technical capability of NFI and the safety of the business alteration were confirmed. The items of the safety examination concerning the alteration, made by the Committee on Examination of Nuclear Fuel Safety of NSC, are as follows: the aseismic design and fire prevention measures of the No.2 processing building and the No.3 waste storage building to be newly installed; criticality control concerning the No.2 processing building; the release control of gaseous and liquid wastes; the management of solid wastes; radiation control; the exposure dose of general public. (J.P.N.)

  1. Environmental protection and processes for burning solid fuel. Zashchita okruzhayushchey sredy i protsessy goreniya tverdovo topliva

    Energy Technology Data Exchange (ETDEWEB)

    1981-01-01

    The anthology's materials are devoted to studying the mechanism of formation of harmful emissions during burning of solid fuels, methods of suppressing processes of formation of nitrogen oxide in boiler devices, and processes of combustion to create power plants with minimal emissions of NO /SUB x/ and SO /SUB x/ and maximum use of organic and mineral components of the fuel.

  2. AW-101 entrained solids - Solubility versus temperature

    International Nuclear Information System (INIS)

    GJ Lumetta; RC Lettau; GF Piepel

    2000-01-01

    This report describes the results of a test conducted by Battelle to assess the solubility of the solids entrained in the diluted AW-101 low-activity waste (LAW) sample. BNFL requested Battelle to dilute the AW-1-1 sample using de-ionized water to mimic expected plant operating conditions. BNFL further requested Battelle to assess the solubility of the solids present in the diluted AW-101 sample versus temperature conditions of 30, 40, and 50 C. BNFL requested these tests to assess the composition of the LAW supernatant and solids versus expected plant-operating conditions. The work was conducted according to test plan BNFL-TP-29953-7, Rev. 0, Determination of the Solubility of LAW Entrained Solids. The test went according to plan, with no deviations from the test plan

  3. Fabrication of Nano-CeO2 and Application of Nano-CeO2 in Fe Matrix Composites

    International Nuclear Information System (INIS)

    Tiebao, W.; Chunxiang, C.; Xiaodong, W.; Guobin, L.

    2010-01-01

    It is expatiated that nano-CeO2 is fabricated by the direct sedimentation method. The components and particles diameter of nano-CeO2 powders are analyzed by XRD and SEM . The thermodynamic analysis and acting mechanism of nano-CeO2 with Al in Fe matrix composites are researched, which shows that the reaction is generated between CeO2 and Al in the composite, that is, 3CeO2+4Al - 2Al2O3+3[Ce], which obtains Al2O3 and active [Ce] during the sintering process. The active [Ce] can improve the performance of CeO2/Fe matrix composites. The suitable amount of CeO2 is about 0.05% in CeO2/Fe matrix composites. SEM fracture analysis shows that the toughness sockets in nano-CeO2/Fe matrix composites are more than those in no-added nano-CeO2 composites, which can explain that adding nano-CeO2 into Fe matrix composite, the toughness of the composite is improved significantly. Applied nano-CeO2 to Fe matrix diamond saw blades shows that Fe matrix diamond saw blade is sharper and of longer cutting life than that with no-added nano-CeO2.

  4. Assessment of the dry process fuel sodium-cooled fast reactors

    Energy Technology Data Exchange (ETDEWEB)

    Roh, Gyu Hong; Choi, Hang Bok

    2004-04-01

    The feasibility of using dry-processed oxide fuel in a Sodium-cooled Fast Reactor (SFR) was analyzed for the equilibrium fuel cycle of two reference cores: Hybrid BN-600 benchmark core with a enlarged lattice pitch and modified BN-600 core. The dry process technology assumed in this study based on the molten-salt process, which was developed by Russian scientists for recycling oxide fuels. The core calculation was performed by the REBUS-3 code and the reactor characteristics such as the transuranic enrichment, breeding ratio, peak linear power, burnup reactivity swing, etc. were calculated for the equilibrium core under a fixed fuel management scheme. The results showed that a self-sustainable breakeven core was achievable without blanket fuels when the fuel volume fraction was {approx}50% and most of the fission products were removed.

  5. Assessment of the dry process fuel sodium-cooled fast reactors

    International Nuclear Information System (INIS)

    Roh, Gyu Hong; Choi, Hang Bok

    2004-04-01

    The feasibility of using dry-processed oxide fuel in a Sodium-cooled Fast Reactor (SFR) was analyzed for the equilibrium fuel cycle of two reference cores: Hybrid BN-600 benchmark core with a enlarged lattice pitch and modified BN-600 core. The dry process technology assumed in this study based on the molten-salt process, which was developed by Russian scientists for recycling oxide fuels. The core calculation was performed by the REBUS-3 code and the reactor characteristics such as the transuranic enrichment, breeding ratio, peak linear power, burnup reactivity swing, etc. were calculated for the equilibrium core under a fixed fuel management scheme. The results showed that a self-sustainable breakeven core was achievable without blanket fuels when the fuel volume fraction was ∼50% and most of the fission products were removed

  6. Studies on the fission products behavior during dissolution process of BWR spent fuel

    International Nuclear Information System (INIS)

    Sato, K.; Nakai, E.; Kobayashi, Y.

    1987-01-01

    In order to obtain basic data on fission products behavior in connection with the head end process of fuel reprocessing, especially to obtain better understanding on undissolved residues, small scale dissolution studies were performed by using BWR spent fuel rods which were irradiated as monitoring fuel rods under the monitoring program for LWR fuel assembly performance entitled PROVING TEST ON RELIABILITY OF FUEL ASSEMBLY . The Zircaloy-2 claddings and the fuel pellets were subjected individually to the following studies on 1) release of fission products during dissolution process, 2) characterization of undissolved residues, and 3) analysis of the claddings. This paper presents comprehensive descriptions of the fission products behavior during dissolution process, based on detailed and through PIE conducted by JNFS under the sponsorship of MITI (Ministry of International Trade and Industry)

  7. Development of nitride fuel and pyrochemical process for transmutation of minor actinides

    International Nuclear Information System (INIS)

    Arai, Yasuo; Akabori, Mitsuo; Minato, Kazuo; Uno, Masayoshi

    2010-01-01

    Nitride fuel cycle for transmutation of minor actinides has been investigated under the double-strata fuel cycle concept. Mononitride solid solutions containing minor actinides have been prepared and characterised. Thermo-physical properties, such as thermal expansion, heat capacity and thermal diffusivity, have been measured by use of minor actinide nitride and burn-up simulated nitride samples. Irradiation behaviour of nitride fuel has been examined by irradiation tests. Pyrochemical process for treatment of spent nitride fuel has been investigated mainly by electrochemical measurements and nitride formation behaviour in pyrochemical process has been studied for recycled fuel fabrication. Recent results of experimental study on nitride fuel and pyrochemical process are summarised in the paper. (authors)

  8. Advanced spent fuel processing technologies for the United States GNEP programme

    International Nuclear Information System (INIS)

    Laidler, J.J.

    2007-01-01

    Spent fuel processing technologies for future advanced nuclear fuel cycles are being developed under the scope of the Global Nuclear Energy Partnership (GNEP). This effort seeks to make available for future deployment a fissile material recycling system that does not involve the separation of pure plutonium from spent fuel. In the nuclear system proposed by the United States under the GNEP initiative, light water reactor spent fuel is treated by means of a solvent extraction process that involves a group extraction of transuranic elements. The recovered transuranics are recycled as fuel material for advanced burner reactors, which can lead in the long term to fast reactors with conversion ratios greater than unity, helping to assure the sustainability of nuclear power systems. Both aqueous and pyrochemical methods are being considered for fast reactor spent fuel processing in the current US development programme. (author)

  9. Handbook on process and chemistry of nuclear fuel reprocessing version 2

    International Nuclear Information System (INIS)

    2008-10-01

    Aqueous nuclear fuel reprocessing technology, based on PUREX technology, has wide applicability as the principal reprocessing technology of the first generation, and relating technologies, waste management for example, are highly developed, too. It is quite important to establish a database summarizing fundamental information about the process and the chemistry of aqueous reprocessing, because it contributes to establish and develop fuel reprocessing technology and nuclear fuel cycle treating high burn-up UO 2 fuel and spent MOX fuel, and to utilize aqueous reprocessing technology much widely. This handbook is the second edition of the first report, which summarizes the fundamental data on process and chemistry, which was collected and examined by 'Editing Committee of Handbook on Process and Chemistry of Nuclear Fuel Reprocessing' from FY 1993 until FY 2000. (author)

  10. Alignment strategies for the entrainment of music and movement rhythms.

    Science.gov (United States)

    Moens, Bart; Leman, Marc

    2015-03-01

    Theories of entrainment assume that spontaneous entrainment emerges from dynamic laws that operate via mediators on interactions, whereby entrainment is facilitated if certain conditions are fulfilled. In this study, we show that mediators can be built that affect the entrainment of human locomotion to music. More specifically, we built D-Jogger, a music player that functions as a mediator between music and locomotion rhythms. The D-Jogger makes it possible to manipulate the timing differences between salient moments of the rhythms (beats and footfalls) through the manipulation of the musical period and phase, which affect the condition in which entrainment functions. We conducted several experiments to explore different strategies for manipulating the entrainment of locomotion and music. The results of these experiments showed that spontaneous entrainment can be manipulated, thereby suggesting different strategies on how to embark. The findings furthermore suggest a distinction among different modalities of entrainment: finding the beat (the most difficult part of entrainment), keeping the beat (easier, as a temporal scheme has been established), and being in phase (no entrainment is needed because the music is always adapted to the human rhythm). This study points to a new avenue of research on entrainment and opens new perspectives for the neuroscience of music. © 2014 New York Academy of Sciences.

  11. Rocket Fuel Synthesis by Fisher-Tropsch Process

    Data.gov (United States)

    National Aeronautics and Space Administration — This study aims to investigate the feasibility of using Fisher Tropsch (FT), a commercial-scale technology that currently produces liquid fuels from syngas (CO &...

  12. Physical modelling of near-wall phenomena in entrained-flow coal gasifiers

    OpenAIRE

    Troiano, Maurizio

    2015-01-01

    Combustion and gasification under slagging conditions are key aspects of the design of modern entrained-flow reactors for thermal conversion of solid fuels, aimed at increasing the overall energy efficiency. In these systems, solid particles migrate toward the reactor walls, due to swirled/tangential flow induced in the reaction chamber and to turbophoresis, generating, thanks to the very high operating temperatures, a slag layer that flows along the reactor internal walls and is drained to t...

  13. ETHANOL DEHYDRATION IN PACKED DISTILLATION COLUMN USING GLYCEROL AS ENTRAINER: EXPERIMENTS AND HETP EVALUATION

    OpenAIRE

    Souza,W. L. R.; Silva,C. S.; Meleiro,L. A. C.; Mendes,M. F.

    2016-01-01

    Abstract The ethanol-water separation is very important because ethanol is widely applied in the chemical industry and its use as a fuel can reduce the pollution emitted to the air. However, anhydrous ethanol production using conventional distillation is impossible, at atmospheric pressure, due to the presence of an azeotrope. In the present work, experimental tests were carried out in order to evaluate the use of glycerol as an entrainer, in substitution of ethylene glycol in an extractive d...

  14. Fuel cells science and engineering. Materials, processes, systems and technology. Vol. 1

    Energy Technology Data Exchange (ETDEWEB)

    Stolten, Detlef; Emonts, Bernd (eds.) [Forschungszentrum Juelich GmbH (DE). Inst. fuer Energieforschung (IEF), Brennstoffzellen (IEF-3)

    2012-07-01

    The first volume is divided in four parts and 22 chapters. It is structured as follows: PART I: Technology. Chapter 1: Technical Advancement of Fuel-Cell Research and Development (Dr. Bernd Emonts, Ludger Blum, Thomas Grube, Werner Lehnert, Juergen Mergel, Martin Mueller and Ralf Peters); 2: Single-Chamber Fuel Cells (Teko W. Napporn and Melanie Kuhn); 3: Technology and Applications of Molten Carbonate Fuel Cells (Barbara Bosio, Elisabetta Arato and Paolo Greppi); 4: Alkaline Fuel Cells (Erich Guelzow); 5: Micro Fuel Cells (Ulf Groos and Dietmar Gerteisen); 6: Principles and Technology of Microbial Fuel Cells (Jan B. A. Arends, Joachim Desloover, Sebastia Puig and Willy Verstraete); 7: Micro-Reactors for Fuel Processing (Gunther Kolb); 8: Regenerative Fuel Cells (Martin Mueller). PART II: Materials and Production Processes. Chapter 9: Advances in Solid Oxide Fuel Cell Development between 1995 and 2010 at Forschungszentrum Juelich GmbH, Germany (Vincent Haanappel); 10: Solid Oxide Fuel Cell Electrode Fabrication by Infiltration (Evren Gunen); 11: Sealing Technology for Solid Oxide Fuel Cells (K. Scott Weil); 12: Phosphoric Acid, an Electrolyte for Fuel Cells - Temperature and Composition Dependence of Vapor Pressure and Proton Conductivity (Carsten Korte); 13: Materials and Coatings for Metallic Bipolar Plates in Polymer Electrolyte Membrane Fuel Cells (Heli Wang and John A. Turner); 14: Nanostructured Materials for Fuel Cells (John F. Elter); 15: Catalysis in Low-Temperature Fuel Cells - An Overview (Sabine Schimpf and Michael Bron). PART III: Analytics and Diagnostics. Chapter 16: Impedance Spectroscopy for High-Temperature Fuel Cells (Ellen Ivers-Tiffee, Andre Leonide, Helge Schichlein, Volker Sonn and Andre Weber); 17: Post-Test Characterization of Solid Oxide Fuel-Cell Stacks (Norbert H. Menzler and Peter Batfalsky); 18: In Situ Imaging at Large-Scale Facilities (Christian Toetzke, Ingo Manke and Werner Lehnert); 19: Analytics of Physical Properties of Low

  15. Structure study of BaCe{sub 0.85}Y{sub 0.15}O{sub 3-Δ} as solid state fuel cell material

    Energy Technology Data Exchange (ETDEWEB)

    Krezhov, K., E-mail: krezhov@inrne.bas.bg; Malakova, T.; Dimitrov, D. [Institute forNuclear Research and Nuclear Energy, Bulgarian Academy of Sciences, Sofia (Bulgaria); Vladikova, D.; Raikova, G.; Genov, I. [Institute of Electrochemistry and Energy Systems, Bulgarian Academy of Sciences, Sofia (Bulgaria); Svab, E. [Wigner Research Center for Physics, RISSPO, Hungarian Academy of Sciences, Budapest (Hungary); Fabian, M. [Wigner Research Center for Physics, RISSPO, Hungarian Academy of Sciences, Budapest (Hungary); Center for Energy Research, Hungarian Academy of Sciences, Budapest (Hungary)

    2016-03-25

    The structural details of powder, dense and porous samples of BaCe{sub 0.85}Y{sub 0.15}O{sub 3−δ} (BCY15) used recently in an innovative monolithic design of SOFC were studied from multiple Rietveld analysis of neutron and x-ray diffraction patterns. The 3-layered monolithic assembly built from BCY15 material works as oxide ion conductor in the oxygen space, as proton conductor in the hydrogen area and as mixed conductor in the central membrane. We find that in all the samples of studied BCY15 based materials there are no indications of difference in crystallographic symmetry and the structure refinements did produce best agreement factors in orthorhombic Pnma space group.

  16. Simulation codes of chemical separation process of spent fuel reprocessing. Tool for process development and safety research

    International Nuclear Information System (INIS)

    Asakura, Toshihide; Sato, Makoto; Matsumura, Masakazu; Morita, Yasuji

    2005-01-01

    This paper reviews the succeeding development and utilization of Extraction System Simulation Code for Advanced Reprocessing (ESSCAR). From the viewpoint of development, more tests with spent fuel and calculations should be performed with better understanding of the physico-chemical phenomena in a separation process. From the viewpoint of process safety research on fuel cycle facilities, it is important to know the process behavior of a key substance; being highly reactive but existing only trace amount. (author)

  17. The effect of acceleration on turbulent entrainment

    International Nuclear Information System (INIS)

    Breidenthal, Robert E

    2008-01-01

    A new class of self-similar turbulent flows is proposed, which exhibits dramatically reduced entrainment rates. Under strong acceleration, the rotation period of the large-scale vortices is forced to decrease linearly in time. In ordinary unforced turbulence, the rotation period always increases linearly with time, at least in the mean. However, by imposing an exponential acceleration on the flow, the vortex rotation period is forced to become the e-folding timescale of the acceleration. If the e-folding timescale itself decreases linearly in time, the forcing is 'super-exponential', characterized by an acceleration parameter α. Based on dimensional and heuristic arguments, a model suggests that the dissipation rate is an exponential function of α and the dimensions of the conserved quantity of the flow. Acceleration decreases the dissipation and entrainment rates in all canonical laboratory flows except for Rayleigh-Taylor. Experiments of exponential jets and super-exponential transverse jets are in accord with the model. As noted by Johari, acceleration is the only known means of affecting the entrainment rate of the far-field jet. Numerical simulations of Rayleigh-Taylor flow by Cook and Greenough are also consistent. In the limit of large acceleration, vortices do not move far before their rotation period changes substantially. In this sense, extreme acceleration corresponds to stationary vortices.

  18. Process and equipment for pressure build-up in nuclear reactor fuel rods

    International Nuclear Information System (INIS)

    Heer, W.F.; Carli, E.V. de.

    1976-01-01

    The equipment makes possible the build-up of inert gas pressure in a filled and closed fuel can, i.e. in a complete fuel rod. Handling is simple, it is suitable for mass production and only causes low processing costs. The quality, e.g. the degree of purity of the contents of the rod, remains unchangedin processing. The equipment consists of a vacuum-tight space, into which the equally vacuum tight fuel rod is introduced, and can be fixed so that its position can be reproduced unmistakeably. The vacuum space contains a connection for the inert gases and a laser arrangement. After inserting a fuel rod into the facility, this is evacuated and the fuel can has a hole bored in it by a laser beam. After fast equalisation of pressure, an inert gas at the required pressure is introduced into the chamber and the fuel rod. After the filling process is completed, the fuel can is closed again with the same laser beam. The quality of the seal obtained, i.e the leak-tightness of the fuel can, can be checked after reduction of the inert gas pressure and before taking out the fuel rod, by repeated evacuation of the chamber. Laser light energies between 13,000 and 110,000 Joule/sq cm are sufficient. Optimum results were obtained for a Zircaloy fuel can with about 52,000 Joule/sq cm. (TK) [de

  19. Entraining the topology and the dynamics of a network of phase oscillators

    Science.gov (United States)

    Sendiña-Nadal, I.; Leyva, I.; Buldú, J. M.; Almendral, J. A.; Boccaletti, S.

    2009-04-01

    We show that the topology and dynamics of a network of unsynchronized Kuramoto oscillators can be simultaneously controlled by means of a forcing mechanism which yields a phase locking of the oscillators to that of an external pacemaker in connection with the reshaping of the network’s degree distribution. The entrainment mechanism is based on the addition, at regular time intervals, of unidirectional links from oscillators that follow the dynamics of a pacemaker to oscillators in the pristine graph whose phases hold a prescribed phase relationship. Such a dynamically based rule in the attachment process leads to the emergence of a power-law shape in the final degree distribution of the graph whenever the network is entrained to the dynamics of the pacemaker. We show that the arousal of a scale-free distribution in connection with the success of the entrainment process is a robust feature, characterizing different networks’ initial configurations and parameters.

  20. ARTIST process. A novel chemical process for treatment of spent nuclear fuel

    International Nuclear Information System (INIS)

    Tachimori, Shoichi

    2001-10-01

    A new chemical process, ARTIST process, is proposed for the treatment of spent nuclear fuel. The main concept of the ARTIST process is to recover and stock all actinides (Ans) as two groups, uranium (U) and a mixture of transuranics (TRU), to preserve their resource value and to dispose solely fission products (FPs). The process is composed of two main steps, an U exclusive isolation and a total recovery of TRU; which copes with the nuclear non-proliferation measures, and additionally of Pu separation process and soft N-donor process if requested, and optionally of processes for separation of long-lived FPs. These An products: U-product and TRU-product, are to be solidified by calcination and allowed to the interim stockpile for future utilization. These separations are achieved by use of amidic extractants in accord with the CHON principle. The technical feasibility of the ARTIST process was explained by the performance of both the branched alkyl monoamides in extracting U and suppressing the extraction of tetravalent Ans due to the steric effect and the diglycolic amide (TODGA) in thorough extraction of all TRU by tridentate fashion. When these TRU are requested to put into reactors, LWR or FBR, for power generation or the Accelerator - Driven System (ADS) for transmutation, Pu (Np) or Am-Cm (Np) are to be extracted from the TRU-product. (author)

  1. Features, Events and Processes for the Used Fuel Disposition Campaign

    International Nuclear Information System (INIS)

    Blink, J.A.; Greenberg, H.R.; Caporuscio, F.A.; Houseworth, J.E.; Freeze, G.A.; Mariner, P.; Cunnane, J.C.

    2010-01-01

    The Used Fuel Disposition (UFD) Campaign within DOE-NE is evaluating storage and disposal options for a range of waste forms and a range of geologic environments. To assess the potential performance of conceptual repository designs for the combinations of waste form and geologic environment, a master set of Features, Events, and Processes (FEPs) has been developed and evaluated. These FEPs are based on prior lists developed by the Yucca Mountain Project (YMP) and the international repository community. The objective of the UFD FEPs activity is to identify and categorize FEPs that are important to disposal system performance for a variety of disposal alternatives (i.e., combinations of waste forms, disposal concepts, and geologic environments). FEP analysis provides guidance for the identification of (1) important considerations in disposal system design, and (2) gaps in the technical bases. The UFD FEPs also support the development of performance assessment (PA) models to evaluate the long-term performance of waste forms in the engineered and geologic environments of candidate disposal system alternatives. For the UFD FEP development, five waste form groups and seven geologic settings are being considered. A total of 208 FEPs have been identified, categorized by the physical components of the waste disposal system as well as cross-cutting physical phenomena. The combination of 35 waste-form/geologic environments and 208 FEPs is large; however, some FEP evaluations can cut across multiple waste/environment combinations, and other FEPs can be categorized as not-applicable for some waste/environment combinations, making the task of FEP evaluation more tractable. A FEP status tool has been developed to document progress. The tool emphasizes three major areas that can be statused numerically. FEP Applicability documents whether the FEP is pertinent to a waste/environment combination. FEP Completion Status documents the progress of the evaluation for the FEP

  2. Implementation process and deployment initiatives for the regionalized storage of DOE-owned spent nuclear fuel

    International Nuclear Information System (INIS)

    Dearien, J.A.; Smith, N.E.L.

    1995-01-01

    This report describes how DOE-owned spent nuclear fuel (SNF) will be stored in the interim 40-year period from 1996 to 2035, by which time it is expected to be in a National Nuclear Repository. The process is described in terms of its primary components: fuel inventory, facilities where it is stored, how the fuel will be moved, and legal issues associated with the process. Tools developed to deploy and fulfill the implementation needs of the National Spent Nuclear Fuel Program are also discussed

  3. New insights into the wind-dust relationship in sandblasting and direct aerodynamic entrainment from wind tunnel experiments

    KAUST Repository

    Parajuli, Sagar Prasad; Zobeck, Ted M.; Kocurek, Gary; Yang, Zong-Liang; Stenchikov, Georgiy L.

    2016-01-01

    Numerous parameterizations have been developed for predicting wind erosion, yet the physical mechanism of dust emission is not fully understood. Sandblasting is thought to be the primary mechanism, but recent studies suggest that dust emission by direct aerodynamic entrainment can be significant under certain conditions. In this work, using wind tunnel experiments, we investigated some of the lesser understood aspects of dust emission in sandblasting and aerodynamic entrainment for three soil types, namely clay, silty clay loam, and clay loam. First, we explored the role of erodible surface roughness on dust emitted by aerodynamic entrainment. Second, we compared the emitted dust concentration in sandblasting and aerodynamic entrainment under a range of wind friction velocities. Finally, we explored the sensitivity of emitted dust particle size distribution (PSD) to soil type and wind friction velocity in these two processes. The dust concentration in aerodynamic entrainment showed strong positive correlation, no significant correlation, and weak negative correlation, for the clay, silty clay loam, and clay loam, respectively, with the erodible soil surface roughness. The dust in aerodynamic entrainment was significant constituting up to 28.3, 41.4, and 146.4% compared to sandblasting for the clay, silty clay loam, and clay loam, respectively. PSD of emitted dust was sensitive to soil type in both sandblasting and aerodynamic entrainment. PSD was sensitive to the friction velocity in aerodynamic entrainment but not in sandblasting. Our results highlight the need to consider the details of sandblasting and direct aerodynamic entrainment processes in parameterizing dust emission in global/regional climate models.

  4. New insights into the wind-dust relationship in sandblasting and direct aerodynamic entrainment from wind tunnel experiments

    KAUST Repository

    Parajuli, Sagar Prasad

    2016-01-22

    Numerous parameterizations have been developed for predicting wind erosion, yet the physical mechanism of dust emission is not fully understood. Sandblasting is thought to be the primary mechanism, but recent studies suggest that dust emission by direct aerodynamic entrainment can be significant under certain conditions. In this work, using wind tunnel experiments, we investigated some of the lesser understood aspects of dust emission in sandblasting and aerodynamic entrainment for three soil types, namely clay, silty clay loam, and clay loam. First, we explored the role of erodible surface roughness on dust emitted by aerodynamic entrainment. Second, we compared the emitted dust concentration in sandblasting and aerodynamic entrainment under a range of wind friction velocities. Finally, we explored the sensitivity of emitted dust particle size distribution (PSD) to soil type and wind friction velocity in these two processes. The dust concentration in aerodynamic entrainment showed strong positive correlation, no significant correlation, and weak negative correlation, for the clay, silty clay loam, and clay loam, respectively, with the erodible soil surface roughness. The dust in aerodynamic entrainment was significant constituting up to 28.3, 41.4, and 146.4% compared to sandblasting for the clay, silty clay loam, and clay loam, respectively. PSD of emitted dust was sensitive to soil type in both sandblasting and aerodynamic entrainment. PSD was sensitive to the friction velocity in aerodynamic entrainment but not in sandblasting. Our results highlight the need to consider the details of sandblasting and direct aerodynamic entrainment processes in parameterizing dust emission in global/regional climate models.

  5. Implementation of a dry process fuel cycle model into the DYMOND code

    International Nuclear Information System (INIS)

    Park, Joo Hwan; Jeong, Chang Joon; Choi, Hang Bok

    2004-01-01

    For the analysis of a dry process fuel cycle, new modules were implemented into the fuel cycle analysis code DYMOND, which was developed by the Argonne National Laboratory. The modifications were made to the energy demand prediction model, a Canada Deuterium Uranium (CANDU) reactor, direct use of spent Pressurized Water Reactor (PWR) fuel in CANDU reactors (DUPIC) fuel cycle model, the fuel cycle calculation module, and the input/output modules. The performance of the modified DYMOND code was assessed for the postulated once-through fuel cycle models including both the PWR and CANDU reactor. This paper presents modifications of the DYMOND code and the results of sample calculations for the PWR once-through and DUPIC fuel cycles

  6. Uncertainty associated with convective wet removal of entrained aerosols in a global climate model

    Directory of Open Access Journals (Sweden)

    B. Croft

    2012-11-01

    Full Text Available The uncertainties associated with the wet removal of aerosols entrained above convective cloud bases are investigated in a global aerosol-climate model (ECHAM5-HAM under a set of limiting assumptions for the wet removal of the entrained aerosols. The limiting assumptions for the wet removal of entrained aerosols are negligible scavenging and vigorous scavenging (either through activation, with size-dependent impaction scavenging, or with the prescribed fractions of the standard model. To facilitate this process-based study, an explicit representation of cloud-droplet-borne and ice-crystal-borne aerosol mass and number, for the purpose of wet removal, is introduced into the ECHAM5-HAM model. This replaces and is compared with the prescribed cloud-droplet-borne and ice-crystal-borne aerosol fraction scavenging scheme of the standard model.

    A 20% to 35% uncertainty in simulated global, annual mean aerosol mass burdens and optical depth (AOD is attributed to different assumptions for the wet removal of aerosols entrained above convective cloud bases. Assumptions about the removal of aerosols entrained above convective cloud bases control modeled upper tropospheric aerosol concentrations by as much as one order of magnitude.

    Simulated aerosols entrained above convective cloud bases contribute 20% to 50% of modeled global, annual mean aerosol mass convective wet deposition (about 5% to 10% of the total dry and wet deposition, depending on the aerosol species, when including wet scavenging of those entrained aerosols (either by activation, size-dependent impaction, or with the prescribed fraction scheme. Among the simulations, the prescribed fraction and size-dependent impaction schemes yield the largest global, annual mean aerosol mass convective wet deposition (by about two-fold. However, the prescribed fraction scheme has more vigorous convective mixed-phase wet removal (by two to five-fold relative to the size-dependent impaction

  7. Uncertainty associated with convective wet removal of entrained aerosols in a global climate model

    Science.gov (United States)

    Croft, B.; Pierce, J. R.; Martin, R. V.; Hoose, C.; Lohmann, U.

    2012-11-01

    The uncertainties associated with the wet removal of aerosols entrained above convective cloud bases are investigated in a global aerosol-climate model (ECHAM5-HAM) under a set of limiting assumptions for the wet removal of the entrained aerosols. The limiting assumptions for the wet removal of entrained aerosols are negligible scavenging and vigorous scavenging (either through activation, with size-dependent impaction scavenging, or with the prescribed fractions of the standard model). To facilitate this process-based study, an explicit representation of cloud-droplet-borne and ice-crystal-borne aerosol mass and number, for the purpose of wet removal, is introduced into the ECHAM5-HAM model. This replaces and is compared with the prescribed cloud-droplet-borne and ice-crystal-borne aerosol fraction scavenging scheme of the standard model. A 20% to 35% uncertainty in simulated global, annual mean aerosol mass burdens and optical depth (AOD) is attributed to different assumptions for the wet removal of aerosols entrained above convective cloud bases. Assumptions about the removal of aerosols entrained above convective cloud bases control modeled upper tropospheric aerosol concentrations by as much as one order of magnitude. Simulated aerosols entrained above convective cloud bases contribute 20% to 50% of modeled global, annual mean aerosol mass convective wet deposition (about 5% to 10% of the total dry and wet deposition), depending on the aerosol species, when including wet scavenging of those entrained aerosols (either by activation, size-dependent impaction, or with the prescribed fraction scheme). Among the simulations, the prescribed fraction and size-dependent impaction schemes yield the largest global, annual mean aerosol mass convective wet deposition (by about two-fold). However, the prescribed fraction scheme has more vigorous convective mixed-phase wet removal (by two to five-fold relative to the size-dependent impaction scheme) since nearly all

  8. Investigation of fuel lean reburning process in a 1.5 MW boiler

    International Nuclear Information System (INIS)

    Kim, Hak Young; Baek, Seung Wook; Kim, Se Won

    2012-01-01

    Highlights: → We examine a detailed study of fuel lean reburning process in a 1.5 MW gas-fired boiler. → Experimental and numerical researches are conducted. → We investigate change in the level of NO X and CO emission. → The recirculation flow is important in the fuel lean reburning process. -- Abstract: This paper examines a detailed study of fuel lean reburning process applied to a 1.5 MW gas-fired boiler. Experimental and numerical studies were carried out to investigate the effect of the fuel lean reburning process on the NO X reduction and CO emission. Natural gas (CH 4 ) was used as the reburn as well as the main fuel. The amount of the reburn fuel, injection location and thermal load of boiler were considered as experimental parameters. The flue gas data revealed that the fuel lean reburning process led to NO X reduction up to 43%, while CO emission was limited to less than 30 ppm for the 100% thermal load condition. The commercial computational fluid dynamics code FLUENT 6.3, which included turbulence, chemical reaction, radiation and NO modeling, was used to predict the fluid flow and heat transfer characteristics under various operational conditions in the boiler. Subsequently, predicted results were validated with available measured data such as gas temperature distributions and local mean NO X concentrations. The detailed numerical results showed that the recirculation flow developed inside the boiler was found to play an important role in improving the effectiveness of fuel lean reburning process.

  9. Manufacturing and investigation of U-Mo LEU fuel granules by hydride-dehydride processing

    International Nuclear Information System (INIS)

    Stetskiy, Y.A.; Trifonov, Y.I.; Mitrofanov, A.V.; Samarin, V.I.

    2002-01-01

    Investigations of hydride-dehydride processing for comminution of U-Mo alloys with Mo content in the range 1.9/9.2% have been performed. Some regularities of the process as a function of Mo content have been determined as well as some parameters elaborated. Hydride-dehydride processing has been shown to provide necessary phase and chemical compositions of U-Mo fuel granules to be used in disperse fuel elements for research reactors. Pin type disperse mini-fuel elements for irradiation tests in the loop of 'MIR' reactor (Dmitrovgrad) have been fabricated using U-Mo LEU fuel granules obtained by hydride-dehydride processing. Irradiation tests of these mini-fuel elements loaded to 4 g U tot /cm 3 are planned to start by the end of this year. (author)

  10. Effects of sintering process, pH and temperature on chemical durability of Ce{sub 0.5}Pr{sub 0.5}PO{sub 4} ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Jiyan; Teng, Yuancheng, E-mail: tyc239@163.com; Huang, Yi; Wu, Lang; Zhang, Kuibao; Zhao, Xiaofeng

    2015-10-15

    The Ce{sub 0.5}Pr{sub 0.5}PO{sub 4} ceramics with high relative density of 99% and small average grain size of 0.15 μm were prepared by hot-pressing at 1150 °C for 2 h. The effects of sintering process, pH values and temperature on the chemical durability of the ceramics were investigated. The results show that normalized elemental leaching rates of Pr (LR{sub Pr}) and Ce (LR{sub Ce}) of the hot-pressed ceramics are slightly lower than that of the ceramics sintered at 1500 °C for 4 h by normal pressure. The LR{sub Pr} and LR{sub Ce} reach the highest values (∼10{sup −3} g m{sup −2} d{sup −1}) when pH = 3, while the LR{sub Pr} and LR{sub Ce} have the lowest values (∼10{sup −7} g m{sup −2} d{sup −1}) when pH = 7. The surface of the ceramic in pH = 3 leachate appears serious corrosion with plenty of pores. The precipitation of low-soluble was formed on sample surface during leaching tests at pH = 9 and 11. - Highlights: • The Ce{sub 0.5}Pr{sub 0.5}PO{sub 4} ceramics with high relative density of 99% and small average grain size of 0.15 µm were prepared by hot-pressing at 1150 ºC for 2 h. • The normalized elemental leaching rates of Pr (LR{sub Pr}) and Ce (LR{sub Ce}) of the hot-pressed ceramics are slightly lower than that of the ceramics sintered at 1500 ºC for 4 h by normal pressure. • The LR{sub Pr} and LR{sub Ce} reach the highest values (∼10{sup −3} g m{sup −2} d{sup −1}) when pH = 3, while the LR{sub Pr} and LR{sub Ce} have the lowest values (∼10{sup −7} g m{sup −2} d{sup −1}) when pH = 7.

  11. Advances in field and analytical methods for estimating entrainment mortality factors

    International Nuclear Information System (INIS)

    Muessig, P.H.; Young, J.R.; Vaughan, D.S.; Smith, B.A.

    1988-01-01

    The hearings and settlement negotiations in the Hudson River case focused on various modeling input factors for calculating reduction in year-class strength of important fish species in the Hudson River due to power plant operations. One of the inputs that received considerable attention, and about which the various parties to the case came to general agreement, was the entrainment mortality factor, or f-factor, the probability that an entrained live organism will be killed as a result of its passage through a power plant in the condenser cooling water. Entrainment mortality includes death due to temperature increases and death due to mechanical processes. The convergence of views about the f-factor arose from increased understanding of the sources of estimation error, improvements in gear for collection of fish larvae, and development of a model for the thermal component of entrainment mortality. Improvements in sampling-gear design reduced potential biases in mortality estimates, reduced estimates of mechanical mortality from 0.923 to 0.412, and improved the statistical power to detect entrainment mortality and the precision of mortality estimates. 20 refs., 7 figs., 1 tab

  12. Getting the beat: entrainment of brain activity by musical rhythm and pleasantness.

    Science.gov (United States)

    Trost, Wiebke; Frühholz, Sascha; Schön, Daniele; Labbé, Carolina; Pichon, Swann; Grandjean, Didier; Vuilleumier, Patrik

    2014-12-01

    Rhythmic entrainment is an important component of emotion induction by music, but brain circuits recruited during spontaneous entrainment of attention by music and the influence of the subjective emotional feelings evoked by music remain still largely unresolved. In this study we used fMRI to test whether the metric structure of music entrains brain activity and how music pleasantness influences such entrainment. Participants listened to piano music while performing a speeded visuomotor detection task in which targets appeared time-locked to either strong or weak beats. Each musical piece was presented in both a consonant/pleasant and dissonant/unpleasant version. Consonant music facilitated target detection and targets presented synchronously with strong beats were detected faster. FMRI showed increased activation of bilateral caudate nucleus when responding on strong beats, whereas consonance enhanced activity in attentional networks. Meter and consonance selectively interacted in the caudate nucleus, with greater meter effects during dissonant than consonant music. These results reveal that the basal ganglia, involved both in emotion and rhythm processing, critically contribute to rhythmic entrainment of subcortical brain circuits by music. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. Word-by-word entrainment of speech rhythm during joint story building

    Directory of Open Access Journals (Sweden)

    Tommi eHimberg

    2015-06-01

    Full Text Available Movements and behaviour synchronise during social interaction at many levels, often unintentionally. During smooth conversation, for example, participants adapt to each others' speech rates. Here we aimed to find out to which extent speakers adapt their turn-taking rhythms during a story-building game.Nine sex-matched dyads of adults (12 males, 6 females created two 5-min stories by contributing to them alternatingly one word at a time. The participants were located in different rooms, with audio connection during one story and audiovisual during the other. They were free to select the topic of the story.Although the participants received no instructions regarding the timing of the story building, their word rhythms were highly entrained (R ̅ = 0.70, p < 0.001 even though the rhythms as such were unstable (R ̅ = 0.14 for pooled data. Such high entrainment in the absence of steady word rhythm occurred in every individual story, independently of whether the subjects were connected via audio-only or audiovisual link.The observed entrainment was of similar strength as typical entrainment in finger-tapping tasks where participants are specifically instructed to synchronize their behaviour. Thus speech seems to spontaneously induce strong entrainment between the conversation partners, likely reflecting automatic alignment of their semantic and syntactic processes.

  14. Technical and economic feasibility of alternative fuel use in process heaters and small boilers

    Energy Technology Data Exchange (ETDEWEB)

    1980-02-01

    The technical and economic feasibility of using alternate fuels - fuels other than oil and natural gas - in combustors not regulated by the Powerplant and Industrial Fuel Use Act of 1978 (FUA) was evaluated. FUA requires coal or alternate fuel use in most large new boilers and in some existing boilers. Section 747 of FUA authorizes a study of the potential for reduced oil and gas use in combustors not subject to the act: small industrial boilers with capacities less than 100 MMBtu/hr, and process heat applications. Alternative fuel use in combustors not regulated by FUA was examined and the impact of several measures to encourage the substitution of alternative fuels in these combustors was analyzed. The primary processes in which significant fuel savings can be achieved are identified. Since feedstock uses of oil and natural gas are considered raw materials, not fuels, feedstock applications are not examined in this analysis. The combustors evaluated in this study comprise approximately 45% of the fuel demand projected in 1990. These uses would account for more than 3.5 million barrels per day equivalent fuel demand in 1990.

  15. Development of processes and equipment for the refabrication of HTGR fuels

    International Nuclear Information System (INIS)

    Sease, J.D.; Lotts, A.L.

    1976-06-01

    Refabrication is in the step in the HTGR thorium fuel cycle that begins with a nitrate solution containing 238 U and culminates in the assembly of this material into fuel elements for use in an HTGR. Refabrication of HTGR fuel is essentially a manufacturing operation and consists of preparation of fuel kernels, application of multiple layers of pyrolytic carbon and SiC, preparation of fuel rods, and assembly of fuel rods in fuel elements. All the equipment for refabrication of 238 U-containing fuel must be designed for completely remote operation and maintenance in hot cell facilities. This paper describes the status of processes and equipment development for the remote refabrication of HTGR fuels. The feasibility of HTGR refabrication processes has been proven by laboratory development. Engineering-scale development is now being performed on a unit basis on the majority of the major equipment items. Engineering-scale equipment described includes full-scale resin loading equipment, a 5-in.-dia (0.13-m) microsphere coating furnace, a fuel rod forming machine, and a cure-in-place furnace

  16. Effect of Colombian coal rank and its feeding technology on substitute natural gas production by entrained gasification

    Directory of Open Access Journals (Sweden)

    Juan Fernando Pérez-Bayer

    2016-01-01

    Full Text Available The effect of coal rank (from sub-bituminous to semi-anthracite and type of fuel feeding technology (slurry and dry on the production of substitute natural gas (SNG in entrained flow gasifiers is studied. Ten coals from important Colombian mines were selected. The process is modeled under thermochemical equilibrium using Aspen Plus, and its performance is evaluated in function of output parameters that include SNG heating value, Wobbe index, coal conversion efficiency, cold gas efficiency, process efficiency, global efficiency, and SNG production rate, among others. In descending order, the coal-to-SNG process improves energetically with the use of coals with: higher volatile-matter to fixed-carbon ratio, lower ash content, higher C+H/O ratio, and higher coal heating value. The overall energy efficiency of the slurry-feed technology (S-FT to produce SNG by gasification is 17% higher than the dry-feed technology (D-FT, possibly as a consequence of the higher CH4 concentration in the syngas (around 7 vol. % when the coal is fed as aqueous slurry. As the simulated SNG meets the natural gas (NG quality standards in Colombia, the substitute gaseous fuel could be directly transported through pipelines. Therefore, the coal-to-SNG process is a technically feasible and unconventional alternative for NG production.

  17. Advanced immobilization processes for fuel hulls and dissolver residues

    International Nuclear Information System (INIS)

    Hebel, W.; Boehme, G.; Findlay, J.R.; Sombret, C.

    1984-08-01

    Various research and development projects for the conditioning of cladding scraps and dissolver residues are pursued within the scope of the R and D programme on nuclear waste Management of the European Community. They include the characterization of the waste materials arising from industrial fuel reprocessing and the development of different waste immobilization techniques. These concern the embedment of scraps and residues into inert matrices like cement, metal alloys, compacted graphite and sintered ceramics as well as the treatment of the fuel hulls by melting or chemical conversion. The conditioned waste forms are tested as to their relevant properties for activity enclosure

  18. Advanced immobilization processes for fuel hulls and dissolver residues

    International Nuclear Information System (INIS)

    Hebel, W.; Boehme, G.; Findlay, J.R.; Sombert, C.

    1984-01-01

    Various research and development projects for the conditioning of cladding scraps and dissolver residues are pursued within the scope of the R and D programme on nuclear waste Management of the European Community. They include the characterization of the waste materials arising from industrial fuel reprocessing and the development of different waste immobilization techniques. These concern the embedment of the scraps and residues into inert matrices like cement, metal alloys, compacted graphite and sintered ceramics as well as the treatment of the fuel hulls by melting or chemical conversion. The conditioned waste forms are tested as to their relevant properties for activity enclosure

  19. Processing of FRG high-temperature gas-cooled reactor fuel elements at General Atomic under the US/FRG cooperative agreement for spent fuel elements

    International Nuclear Information System (INIS)

    Holder, N.D.; Strand, J.B.; Schwarz, F.A.; Drake, R.N.

    1981-11-01

    The Federal Republic of Germany (FRG) and the United States (US) are cooperating on certain aspects of gas-cooled reactor technology under an umbrella agreement. Under the spent fuel treatment development section of the agreement, both FRG mixed uranium/ thorium and low-enriched uranium fuel spheres have been processed in the Department of Energy-sponsored cold pilot plant for high-temperature gas-cooled reactor (HTGR) fuel processing at General Atomic Company in San Diego, California. The FRG fuel spheres were crushed and burned to recover coated fuel particles suitable for further treatment for uranium recovery. Successful completion of the tests described in this paper demonstrated certain modifications to the US HTGR fuel burining process necessary for FRG fuel treatment. Results of the tests will be used in the design of a US/FRG joint prototype headend facility for HTGR fuel

  20. Processing of FRG mixed oxide fuel elements at General Atomic under the US/FRG cooperative agreement for spent fuel elements

    International Nuclear Information System (INIS)

    Holder, N.D.; Strand, J.B.; Schwarz, F.A.; Tischer, H.E.

    1980-11-01

    The Federal Republic of Germany (FRG) and the United States (US) are cooperating on certain aspects gas-cooled reactor technology under an umbrella agreement. Under the spent fuel treatment section of the agreement, FRG fuel spheres were recently sent for processing in the Department of Energy sponsored cold pilot plant for High-Temperature Gas-Cooled Reactor (HTGR) fuel processing at General Atomic Company in San Diego, California. The FRG fuel spheres were crushed and burned to recover coated fuel particles. These particles were in turn crushed and burned to recover the fuel-bearing kernels for further treatment for uranium recovery. Successful completion of the tests described in this paper demonstrated the applicability of the US HTGR fuel treatment flowsheet to FRG fuel processing. 10 figures

  1. The Importance of Stochastic Effects for Explaining Entrainment in the Zebrafish Circadian Clock

    Directory of Open Access Journals (Sweden)

    Raphaela Heussen

    2015-01-01

    Full Text Available The circadian clock plays a pivotal role in modulating physiological processes and has been implicated, either directly or indirectly, in a range of pathological states including cancer. Here we investigate how the circadian clock is entrained by external cues such as light. Working with zebrafish cell lines and combining light pulse experiments with simulation efforts focused on the role of synchronization effects, we find that even very modest doses of light exposure are sufficient to trigger some entrainment, whereby a higher light intensity or duration correlates with strength of the circadian signal. Moreover, we observe in the simulations that stochastic effects may be considered an essential feature of the circadian clock in order to explain the circadian signal decay in prolonged darkness, as well as light initiated resynchronization as a strong component of entrainment.

  2. Observational study of the relationship between entrainment rate and relative dispersion in deep convective clouds

    Science.gov (United States)

    Guo, Xiaohao; Lu, Chunsong; Zhao, Tianliang; Liu, Yangang; Zhang, Guang Jun; Luo, Shi

    2018-01-01

    This study investigates the influence of entrainment rate (λ) on relative dispersion (ε) of cloud droplet size distributions (CDSD) in the 99 growing precipitating deep convective clouds during TOGA-COARE. The results show that entrainment suppresses ε, which is opposite to the traditional understanding that entrainment-mixing broadens CDSD. To examine how the relationship between ε and λ is affected by droplets with different sizes, CDSDs are divided into three portions with droplet radius processes is developed to illustrate the possible scenarios entailing different relationships between ε and λ. The number concentration of small droplets and the degree of evaporation of small droplets are found to be key factors that shift the sign (i.e., positive or negative) of the ε-λ relationship.

  3. Methodological aspects of fuel performance system analysis at raw hydrocarbon processing plants

    Science.gov (United States)

    Kulbjakina, A. V.; Dolotovskij, I. V.

    2018-01-01

    The article discusses the methodological aspects of fuel performance system analysis at raw hydrocarbon (RH) processing plants. Modern RH processing facilities are the major consumers of energy resources (ER) for their own needs. To reduce ER, including fuel consumption, and to develop rational fuel system structure are complex and relevant scientific tasks that can only be done using system analysis and complex system synthesis. In accordance with the principles of system analysis, the hierarchical structure of the fuel system, the block scheme for the synthesis of the most efficient alternative of the fuel system using mathematical models and the set of performance criteria have been developed on the main stages of the study. The results from the introduction of specific engineering solutions to develop their own energy supply sources for RH processing facilities have been provided.

  4. Process and system to encapsulate spent nuclear fuel

    International Nuclear Information System (INIS)

    Gunasekaran, Muthian; Fleischer, L.R.

    1980-01-01

    System for encapsulating spent nuclear fuel containing active fission matter and comprised in a metal casing, where concrete covers this casing in a contiguous, uniform and complete manner. It is characterized in that this concrete contains metal fibres to raise the thermal conductivity and polymers for increasing impermeability and that convection facilities are provided for cooling the outer surface of the concrete [fr

  5. Sustainable Production of Asphalt using Biomass as Primary Process Fuel

    DEFF Research Database (Denmark)

    Bühler, Fabian; Nguyen, Tuong-Van; Elmegaard, Brian

    2016-01-01

    is the heating and drying of aggregate,where natural gas, fuel oil or LPG is burned in a direct-fired rotary dryer. Replacing this energy source with amore sustainable one presents several technical and economic challenges, as high temperatures, short startuptimes and seasonal production variations are required...

  6. Flowsheet for shear/leach processing of N Reactor fuel at PUREX

    International Nuclear Information System (INIS)

    Enghusen, M.B.

    1995-01-01

    This document was originally prepared to support the restart of the PUREX plant using a new Shear/Leach head end process. However, the PUREX facility was shutdown and processing of the remaining N Reactor fuel is no longer considered an alternative for fuel disposition. This document is being issued for reference only to document the activities which were investigated to incorporate the shear/leach process in the PUREX plant

  7. Literature on fabrication of tungsten for application in pyrochemical processing of spent nuclear fuels

    International Nuclear Information System (INIS)

    Edstrom, C.M.; Phillips, A.G.; Johnson, L.D.; Corle, R.R.

    1980-01-01

    The pyrochemical processing of nuclear fuels requires crucibles, stirrers, and transfer tubing that will withstand the temperature and the chemical attack from molten salts and metals used in the process. This report summarizes the literature that pertains to fabrication (joining, chemical vapor deposition, plasma spraying, forming, and spinning) is the main theme. This report also summarizes a sampling of literature on molbdenum and the work previously performed at Argonne National Laboratory on other container materials used for pyrochemical processing of spent nuclear fuels

  8. Processes for converting biomass-derived feedstocks to chemicals and liquid fuels

    Science.gov (United States)

    Held, Andrew; Woods, Elizabeth; Cortright, Randy; Gray, Matthew

    2018-04-17

    The present invention provides processes, methods, and systems for converting biomass-derived feedstocks to liquid fuels and chemicals. The method generally includes the reaction of a hydrolysate from a biomass deconstruction process with hydrogen and a catalyst to produce a reaction product comprising one of more oxygenated compounds. The process also includes reacting the reaction product with a condensation catalyst to produce C.sub.4+ compounds useful as fuels and chemicals.

  9. Processes for converting biomass-derived feedstocks to chemicals and liquid fuels

    Science.gov (United States)

    Held, Andrew; Woods, Elizabeth; Cortright, Randy; Gray, Matthew

    2017-05-23

    The present invention provides processes, methods, and systems for converting biomass-derived feedstocks to liquid fuels and chemicals. The method generally includes the reaction of a hydrolysate from a biomass deconstruction process with hydrogen and a catalyst to produce a reaction product comprising one of more oxygenated compounds. The process also includes reacting the reaction product with a condensation catalyst to produce C.sub.4+ compounds useful as fuels and chemicals.

  10. Systems Analysis of an Advanced Nuclear Fuel Cycle Based on a Modified UREX+3c Process

    Energy Technology Data Exchange (ETDEWEB)

    E. R. Johnson; R. E. Best

    2009-12-28

    The research described in this report was performed under a grant from the U.S. Department of Energy (DOE) to describe and compare the merits of two advanced alternative nuclear fuel cycles -- named by this study as the “UREX+3c fuel cycle” and the “Alternative Fuel Cycle” (AFC). Both fuel cycles were assumed to support 100 1,000 MWe light water reactor (LWR) nuclear power plants operating over the period 2020 through 2100, and the fast reactors (FRs) necessary to burn the plutonium and minor actinides generated by the LWRs. Reprocessing in both fuel cycles is assumed to be based on the UREX+3c process reported in earlier work by the DOE. Conceptually, the UREX+3c process provides nearly complete separation of the various components of spent nuclear fuel in order to enable recycle of reusable nuclear materials, and the storage, conversion, transmutation and/or disposal of other recovered components. Output of the process contains substantially all of the plutonium, which is recovered as a 5:1 uranium/plutonium mixture, in order to discourage plutonium diversion. Mixed oxide (MOX) fuel for recycle in LWRs is made using this 5:1 U/Pu mixture plus appropriate makeup uranium. A second process output contains all of the recovered uranium except the uranium in the 5:1 U/Pu mixture. The several other process outputs are various waste streams, including a stream of minor actinides that are stored until they are consumed in future FRs. For this study, the UREX+3c fuel cycle is assumed to recycle only the 5:1 U/Pu mixture to be used in LWR MOX fuel and to use depleted uranium (tails) for the makeup uranium. This fuel cycle is assumed not to use the recovered uranium output stream but to discard it instead. On the other hand, the AFC is assumed to recycle both the 5:1 U/Pu mixture and all of the recovered uranium. In this case, the recovered uranium is reenriched with the level of enrichment being determined by the amount of recovered plutonium and the combined amount

  11. Systems Analysis of an Advanced Nuclear Fuel Cycle Based on a Modified UREX+3c Process

    International Nuclear Information System (INIS)

    Johnson, E.R.; Best, R.E.

    2009-01-01

    The research described in this report was performed under a grant from the U.S. Department of Energy (DOE) to describe and compare the merits of two advanced alternative nuclear fuel cycles -- named by this study as the 'UREX+3c fuel cycle' and the 'Alternative Fuel Cycle' (AFC). Both fuel cycles were assumed to support 100 1,000 MWe light water reactor (LWR) nuclear power plants operating over the period 2020 through 2100, and the fast reactors (FRs) necessary to burn the plutonium and minor actinides generated by the LWRs. Reprocessing in both fuel cycles is assumed to be based on the UREX+3c process reported in earlier work by the DOE. Conceptually, the UREX+3c process provides nearly complete separation of the various components of spent nuclear fuel in order to enable recycle of reusable nuclear materials, and the storage, conversion, transmutation and/or disposal of other recovered components. Output of the process contains substantially all of the plutonium, which is recovered as a 5:1 uranium/plutonium mixture, in order to discourage plutonium diversion. Mixed oxide (MOX) fuel for recycle in LWRs is made using this 5:1 U/Pu mixture plus appropriate makeup uranium. A second process output contains all of the recovered uranium except the uranium in the 5:1 U/Pu mixture. The several other process outputs are various waste streams, including a stream of minor actinides that are stored until they are consumed in future FRs. For this study, the UREX+3c fuel cycle is assumed to recycle only the 5:1 U/Pu mixture to be used in LWR MOX fuel and to use depleted uranium (tails) for the makeup uranium. This fuel cycle is assumed not to use the recovered uranium output stream but to discard it instead. On the other hand, the AFC is assumed to recycle both the 5:1 U/Pu mixture and all of the recovered uranium. In this case, the recovered uranium is reenriched with the level of enrichment being determined by the amount of recovered plutonium and the combined amount of the

  12. Assessment of the Dry Processed Oxide Fuel in Liquid Metal Fast Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Roh, Gyu Hong; Choi, Hang Bok

    2005-09-15

    The neutronic feasibility of the dry process oxide fuel was assessed for the sodium-cooled and lead-cooled fast reactors (SFR and LFR, respectively), which were recommended as Generation-IV (Gen-IV) reactor systems by the Gen-IV international forum. The reactor analysis was performed for the equilibrium fuel cycle of two core configurations: Hybrid BN-600 benchmark core with an enlarged lattice pitch and a modified BN-600 core. The dry process technology assumed in this study is the molten-salt process, which was developed by Russian scientists for recycling oxide fuels. The core calculation was performed by the REBUS-3 code and the reactor characteristics such as the transuranic (TRU) enrichment, breeding ratio, peak linear power, burnup reactivity swing, etc. were calculated for the equilibrium core under a fixed fuel management scheme. The results showed that a fissile self-sustainable breakeven core was achievable without blanket fuels when the fuel volume fraction was {approx}50% and most of the fission products were removed. If the design criteria used in this study is proved to be acceptable through a detailed physics design and thermal hydraulic analysis in the future, it is practically possible to construct an equilibrium fuel cycle of the SFR and LFR systems based on the oxide fuel by utilizing the dry process technology.

  13. Assessment of the Dry Processed Oxide Fuel in Liquid Metal Fast Reactors

    International Nuclear Information System (INIS)

    Roh, Gyu Hong; Choi, Hang Bok

    2005-09-01

    The neutronic feasibility of the dry process oxide fuel was assessed for the sodium-cooled and lead-cooled fast reactors (SFR and LFR, respectively), which were recommended as Generation-IV (Gen-IV) reactor systems by the Gen-IV international forum. The reactor analysis was performed for the equilibrium fuel cycle of two core configurations: Hybrid BN-600 benchmark core with an enlarged lattice pitch and a modified BN-600 core. The dry process technology assumed in this study is the molten-salt process, which was developed by Russian scientists for recycling oxide fuels. The core calculation was performed by the REBUS-3 code and the reactor characteristics such as the transuranic (TRU) enrichment, breeding ratio, peak linear power, burnup reactivity swing, etc. were calculated for the equilibrium core under a fixed fuel management scheme. The results showed that a fissile self-sustainable breakeven core was achievable without blanket fuels when the fuel volume fraction was ∼50% and most of the fission products were removed. If the design criteria used in this study is proved to be acceptable through a detailed physics design and thermal hydraulic analysis in the future, it is practically possible to construct an equilibrium fuel cycle of the SFR and LFR systems based on the oxide fuel by utilizing the dry process technology

  14. Development of new decladding system in the reprocessing process for FBR fuel

    International Nuclear Information System (INIS)

    Yamada, Seiya; Washiya, Tadahiro; Takeuchi, Masayuki; Koizumi, Tsutomu; Aose, Shinichi

    2005-01-01

    As a part of the feasibility study on commercialized fast reactor cycle systems, Japan Nuclear Cycle Development Institute (JNC) has been developing the fuel decladding technology for the dry reprocessing process (oxide electrowinning process) and aqueous reprocessing process. Particularly, in the oxide electrowinning process, the spent fuel should be reduced to powder for quick dissolution in the molten salt at electrolyzer. Therefore, JNC proposes new decladding system with innovative mechanical decladding devices. The decladding system consists of fuel crushing stage, hull separation stage and hull rinsing stage. In the fuel crushing stage, disassembled spent fuel pins are crushed and powdered by mechanical decladding device, then the following stage, the hull and the fuel powder are separated by magnetic separator. Only the fuel powder is fed to the electrolyzer. On the other side, the separated hull is melted by induction heating method, and the small amount of oxide included in the hull fragments is recovered at the hull rinsing stage. The recovered oxide fuel is fed back to the electrolyzer. In this paper, the basic performance of the element equipment that composes this new decladding system will be described. (author)

  15. SYSTEM AND PROCESS FOR PRODUCTION OF METHANOL FROM COMBINED WIND TURBINE AND FUEL CELL POWER

    Science.gov (United States)

    The paper examines an integrated use of ultra-clean wind turbines and high temperature fuel cells to produce methanol, especially for transportation purposes. The principal utility and application of the process is the production of transportation fuel from domestic resources to ...

  16. Charred olive stones: experimental and archaeological evidence for recognizing olive processing residues used as fuel

    NARCIS (Netherlands)

    Braadbaart, Freek; Marinova, E.; Sarpaki, A.

    After extracting oil from olives a residue is left usually referred to as the olive oil processing residue (OPR). This study explores the way in which ancient societies may have used OPR as fuel for fires to generate heat and the various issues that are related to the residues of this fuel. After

  17. Investigation of the gas formation in dissolution process of nuclear reactor fuel

    International Nuclear Information System (INIS)

    Zhang Qinfen; Liao Yuanzhong; Chen Yongqing; Sun Shuyun; Fan Yincheng

    1987-12-01

    The gas formation in dissolution process of two kinds of nuclear fuels was studied. The results shows that the maximum volume flow released from dissolution system is composed of two parts. One of them is air remained in dissolver and pushed out by acid vapor. The other is produced in dissolution reaction. The procedure of calculating the gas amount produced in dissolution process has been given. It is based on variation of components of dissolution solution. The gas amount produced in dissolution process of spent UO 2 fuel elements was calculated. The condenser system and loading volume of disposal system of tail gas of dissolution of spent fuel were discussed

  18. SAF: the next generation process for radiotoxic material handling in the nuclear fuel industry

    International Nuclear Information System (INIS)

    Nyman, D.H.; Graham, R.A.

    1984-01-01

    In 1980 the Secure Automated Fabrication (SAF) Project was established with the goal to design, build, and operate a remote process for manufacturing breeder reactor fuel pins. The SAF line will be housed in the Fuels and Materials Examination Facility (FMEF) at the Hanford site. The fabrication system and supporting operations are designed for computer-controlled operation from a centralized control room. In addition to improved worker protection, remote and automated fuel fabrication operations will result in enhanced safeguards and accountability of fuel material, improved product quality, and increased productivity. Installation of the SAF line equipment has started. Qualification runs are scheduled to begin in 1986 with production commencing in 1987

  19. Entrainment to periodic initiation and transition rates in a computational model for gene translation.

    Directory of Open Access Journals (Sweden)

    Michael Margaliot

    Full Text Available Periodic oscillations play an important role in many biomedical systems. Proper functioning of biological systems that respond to periodic signals requires the ability to synchronize with the periodic excitation. For example, the sleep/wake cycle is a manifestation of an internal timing system that synchronizes to the solar day. In the terminology of systems theory, the biological system must entrain or phase-lock to the periodic excitation. Entrainment is also important in synthetic biology. For example, connecting several artificial biological systems that entrain to a common clock may lead to a well-functioning modular system. The cell-cycle is a periodic program that regulates DNA synthesis and cell division. Recent biological studies suggest that cell-cycle related genes entrain to this periodic program at the gene translation level, leading to periodically-varying protein levels of these genes. The ribosome flow model (RFM is a deterministic model obtained via a mean-field approximation of a stochastic model from statistical physics that has been used to model numerous processes including ribosome flow along the mRNA. Here we analyze the RFM under the assumption that the initiation and/or transition rates vary periodically with a common period T. We show that the ribosome distribution profile in the RFM entrains to this periodic excitation. In particular, the protein synthesis pattern converges to a unique periodic solution with period T. To the best of our knowledge, this is the first proof of entrainment in a mathematical model for translation that encapsulates aspects such as initiation and termination rates, ribosomal movement and interactions, and non-homogeneous elongation speeds along the mRNA. Our results support the conjecture that periodic oscillations in tRNA levels and other factors related to the translation process can induce periodic oscillations in protein levels, and may suggest a new approach for re-engineering genetic

  20. Processing used nuclear fuel with nanoscale control of uranium and ultrafiltration

    Energy Technology Data Exchange (ETDEWEB)

    Wylie, Ernest M.; Peruski, Kathryn M.; Prizio, Sarah E. [Department of Civil and Environmental Engineering and Earth Sciences, University of Notre Dame, Notre Dame, IN 46556 (United States); Bridges, Andrea N.A.; Rudisill, Tracy S.; Hobbs, David T. [Savannah River National Laboratory, Aiken, SC 29808 (United States); Phillip, William A. [Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, IN 46556 (United States); Burns, Peter C., E-mail: pburns@nd.edu [Department of Civil and Environmental Engineering and Earth Sciences, University of Notre Dame, Notre Dame, IN 46556 (United States); Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556 (United States)

    2016-05-15

    Current separation and purification technologies utilized in the nuclear fuel cycle rely primarily on liquid–liquid extraction and ion-exchange processes. Here, we report a laboratory-scale aqueous process that demonstrates nanoscale control for the recovery of uranium from simulated used nuclear fuel (SIMFUEL). The selective, hydrogen peroxide induced oxidative dissolution of SIMFUEL material results in the rapid assembly of persistent uranyl peroxide nanocluster species that can be separated and recovered at moderate to high yield from other process-soluble constituents using sequestration-assisted ultrafiltration. Implementation of size-selective physical processes like filtration could results in an overall simplification of nuclear fuel cycle technology, improving the environmental consequences of nuclear energy and reducing costs of processing. - Highlights: • Nanoscale control in irradiated fuel reprocessing. • Ultrafiltration to recover uranyl cage clusters. • Alternative to solvent extraction for uranium purification.

  1. On-line ultrasonic gas entrainment monitor

    International Nuclear Information System (INIS)

    Day, C.K.; Pedersen, H.N.

    1978-01-01

    Apparatus employing ultrasonic energy for detecting and measuring the quantity of gas bubbles present in liquids being transported through pipes is described. An ultrasonic transducer is positioned along the longitudinal axis of a fluid duct, oriented to transmit acoustic energy radially of the duct around the circumference of the enclosure walls. The back-reflected energy is received centrally of the duct and interpreted as a measure of gas entrainment. One embodiment employs a conical reflector to direct the transmitted acoustic energy radially of the duct and redirect the reflected energy back to the transducer for reception. A modified embodiment employs a cylindrical ultrasonic transducer for this purpose

  2. Disposal of defense spent fuel and HLW from the Idaho Chemical Processing Plant

    International Nuclear Information System (INIS)

    Ermold, L.F.; Loo, H.H.; Klingler, R.D.; Herzog, J.D.; Knecht, D.A.

    1992-12-01

    Acid high-level radioactive waste (HLW) resulting from fuel reprocessing at the Idaho Chemical Processing Plant (ICPP) for the US Department of Energy (DOE) has been solidified to a calcine since 1963 and stored in stainless steel bins enclosed by concrete vaults. Several different types of unprocessed irradiated DOE-owned fuels are also in storage ate the ICPP. In April, 1992, DOE announced that spent fuel would no longer be reprocessed to recover enriched uranium and called for a shutdown of the reprocessing facilities at the ICPP. A new Spent Fuel and HLW Technology Development program was subsequently initiated to develop technologies for immobilizing ICPP spent fuels and HLW for disposal, in accordance with the Nuclear Waste Policy Act. The Program elements include Systems Analysis, Graphite Fuel Disposal, Other Spent Fuel Disposal, Sodium-Bearing Liquid Waste Processing, Calcine Immobilization, and Metal Recycle/Waste Minimization. This paper presents an overview of the ICPP radioactive wastes and current spent fuels, with an emphasis on the description of HLW and spent fuels requiring repository disposal

  3. The electrical conductivity of model melts based on LiCl-KCl, used for the processing of spent nuclear fuel

    International Nuclear Information System (INIS)

    Salyulev, Alexander; Potapov, Alexei; Khokhlov, Vladimir; Shishkin, Vladimir

    2017-01-01

    During pyrochemical reprocessing of spent nuclear fuel, complex melts based on LiCl-KCl eutectic are formed, but their properties are still not well studied. We measured the electrical conductivity of (LiCl-KCl) eut. − CeCl 3 , (LiCl-KCl) eut. − NdCl 3 and (LiCl-KCl) eut. − UCl 3 quasi-binary melts was up to 40 mol.% CeCl 3 , 40 mol.% NdCl 3 and 10.45 mol.% UCl 3 in a wide temperature span. In addition the electrical conductivity of several compositions, such as (LiCl-KCl) eut. − CeCl 3 + NdCl 3 and (LiCl-KCl) eut. − CeCl 3 + NdCl 3 + UCl 3 was measured. The measurements were carried out in quartz cells of the capillary type. When the total concentration of trivalent ions is less than 12 mol.%, we found that the conductivity of mixtures of arbitrary composition is almost a linear function of CeCl 3 , NdCl 3 , and UCl 3 the overall concentration.

  4. Intermediate-to-low temperature protonic ceramic membrane fuel cells with Ba{sub 0.5}Sr{sub 0.5}Co{sub 0.8}Fe{sub 0.2}O{sub 3-{delta}}-BaZr{sub 0.1}Ce{sub 0.7}Y{sub 0.2}O{sub 3-{delta}} composite cathode

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Bin; Ding, Hanping; Dong, Yingchao; Wang, Songlin; Zhang, Xiaozhen; Fang, Daru; Meng, Guangyao [Department of Materials Science and Engineering, University of Science and Technology of China (USTC), Hefei, Anhui 230026 (China)

    2009-01-01

    The perovskite-type Ba{sub 0.5}Sr{sub 0.5}Co{sub 0.8}Fe{sub 0.2}O{sub 3-{delta}}-BaZr{sub 0.1}Ce{sub 0.7}Y{sub 0.2}O{sub 3-{delta}} (BSCF-BZCY) composite oxides were synthesized by a modified Pechini method and examined as a novel composite cathode for intermediate-to-low temperature protonic ceramic membrane fuel cells (ILT-PCMFCs). Thin proton-conducting BaZr{sub 0.1}Ce{sub 0.7}Y{sub 0.2}O{sub 3-{delta}} (BZCY) electrolyte and NiO-BaZr{sub 0.1}Ce{sub 0.7}Y{sub 0.2}O{sub 3-{delta}} (NiO-BZCY) anode functional layer were prepared over porous anode substrates composed of NiO-BaZr{sub 0.1}Ce{sub 0.7}Y{sub 0.2}O{sub 3-{delta}} by a one-step dry-pressing/co-firing process. A laboratory-sized quad-layer cell of NiO-BZCY/NiO-BZCY({proportional_to}50 {mu}m)/BZCY({proportional_to}20 {mu}m)/BSCF-BZCY({proportional_to}50 {mu}m) was operated from 550 to 700 C with humidified hydrogen ({proportional_to}3% H{sub 2}O) as fuel and the static air as oxidant. A high open-circuit potential of 1.009 V, a maximum power density of 418 mW cm{sup -2}, and a low polarization resistance of the electrodes of 0.10 {omega} cm{sup 2} was achieved at 700 C. These investigations have indicated that proton-conducting BZCY electrolyte with BSCF perovskite cathode is a promising material system for the next generation solid oxide fuel cells (SOFCs). (author)

  5. Technical and economic modelling of processes for liquid fuel production in Europe

    Energy Technology Data Exchange (ETDEWEB)

    Bridgwater, A V; Double, J M [Aston Univ. Birmingham (GB). Dept of Chemical Engineering

    1992-12-31

    The project which is described had the objective of examining the full range of technologies for liquid fuel production from renewable feedstocks in a technical and economic evaluation in order to identify the most promising technologies. The technologies considered are indirect thermochemical liquefaction (i.e. via gasification) to produce methanol, fuel alcohol or hydrocarbon fuels, direct thermochemical liquefaction or pyrolysis to produce hydrocarbon fuels and fermentation to produce ethanol. Feedstocks considered were wood, refuse derived fuel, straw, wheat and sugar beet. In order to carry out the evaluation, a computer model was developed, based on a unit process approach. Each unit operation is modelled as a process step, the model calculating the mass balance, energy balance and operating cost of the unit process. The results from the process step models are then combined to generate the mass balance, energy balance, capital cost and operating cost for the total process. The results show that the lowest production cost (L7/GJ) is obtained for methanol generated from a straw feedstock, but there is a moderate level of technical uncertainty associated with this result. The lowest production cost for hydrocarbon fuel (L8.6/GJ) is given by the pyrolysis process using a wood feedstock. This process has a high level of uncertainty. Fermentation processes showed the highest production costs, ranging from L14.4/GJ for a simple wood feedstock process to L25.2/GJ for a process based on sugar beet. The important conclusions are as follows: - In every case, the product cost is above current liquid fuel prices; - In most cases the feedstock cost dominates the production cost; -The most attractive products are thermochemically produced alcohol fuels.

  6. Technical and economic modelling of processes for liquid fuel production in Europe

    International Nuclear Information System (INIS)

    Bridgwater, A.V.; Double, J.M.

    1991-01-01

    The project which is described had the objective of examining the full range of technologies for liquid fuel production from renewable feedstocks in a technical and economic evaluation in order to identify the most promising technologies. The technologies considered are indirect thermochemical liquefaction (i.e. via gasification) to produce methanol, fuel alcohol or hydrocarbon fuels, direct thermochemical liquefaction or pyrolysis to produce hydrocarbon fuels and fermentation to produce ethanol. Feedstocks considered were wood, refuse derived fuel, straw, wheat and sugar beet. In order to carry out the evaluation, a computer model was developed, based on a unit process approach. Each unit operation is modelled as a process step, the model calculating the mass balance, energy balance and operating cost of the unit process. The results from the process step models are then combined to generate the mass balance, energy balance, capital cost and operating cost for the total process. The results show that the lowest production cost (L7/GJ) is obtained for methanol generated from a straw feedstock, but there is a moderate level of technical uncertainty associated with this result. The lowest production cost for hydrocarbon fuel (L8.6/GJ) is given by the pyrolysis process using a wood feedstock. This process has a high level of uncertainty. Fermentation processes showed the highest production costs, ranging from L14.4/GJ for a simple wood feedstock process to L25.2/GJ for a process based on sugar beet. The important conclusions are as follows: - In every case, the product cost is above current liquid fuel prices; - In most cases the feedstock cost dominates the production cost; -The most attractive products are thermochemically produced alcohol fuels

  7. Assessment of impact due to entrainment of ichthyoplankton

    International Nuclear Information System (INIS)

    Horst, T.J.

    1975-01-01

    Three approaches to the assessment of impact associated with the entrainment of ichthyoplankton into power stations are discussed. The first is the estimation of the probability of mortality for those organisms entrained. The second is the assessment to the fish populations which have the egg and larvae life stages entrained. The third approach is the assessment of impact to the community or ecosystem. Some models are presented as examples for each of the three approaches. (U.S.)

  8. Study of the oxygen reduction reaction using Pt-Rare earths (La, Ce, Er) electrocatalysts for application of PEM fuel cells; Estudo da reacao de reducao do oxigenio utilizando eletrocatalisadores a base de Pt-terras raras (La, Ce, Er) para aplicacao em celulas a combustivel tipo PEM

    Energy Technology Data Exchange (ETDEWEB)

    Gomes, Thiago Bueno

    2013-07-01

    The complexity of the oxygen reduction reaction (ORR) and its potential losses make it responsible for the most part of efficiency losses at the Fuel Cells. For this reaction the electrocatalyst witch is most appropriated and shows better performance is platinum, a noble metal that elevates the cost, raising barriers for Fuel Cells technology to enter the market. First this work focuses on reducing the amount of platinum used in the cathode, by being replaced by rare earths. The most common methods of synthesis involves a large amount of steps and this work proposed to prepare the electrocatalyst through a simpler way that would not take so many steps and time to be done. Using an ultrasound mixer the electrocatalyst was prepared mixing platinum supported on carbon black and the rare earths lanthanum, cerium and erbium oxides to be applied in a half-cell study of the ORR. The Koutecky-Levich plots shows that among the electrocatalysts prepared the Pt80Ce20/C had the catalytic activity close to the commercial BASF platinum on carbon black, suggesting that the reaction was taken by the 4-electron path. As found in some works in literature, among the rare earth used to study the ORR, cerium is the one witch shows the better performance because it is able to store and provide oxygen. This feature is of great interest for the ORR because this reaction is first order to the oxygen concentration. Results show that is possible to reduce the amount of platinum maintaining the same electrocatalyst activity. (author)

  9. Advanced Diagnostics in Oxy-Fuel Combustion Processes

    DEFF Research Database (Denmark)

    Brix, Jacob; Toftegaard, Maja Bøg; Clausen, Sønnik

    This report sums up the findings in PSO-project 010069, “Advanced Diagnostics in Oxy- Fuel Combustion Processes”. Three areas of optic diagnostics are covered in this work: - FTIR measurements in a 30 kW swirl burner. - IR measurements in a 30 kW swirl burner. - IR measurements in a laboratory...... technique was an invaluable tool in the discussion of data obtained by gas analysis, and it allowed for estimation of combustion times in O2/CO2 where the high CO2 concentration prevents the use of the carbon mass balance for that purpose. During the project the data have been presented at a conference......, formed the basis of a publication and it is part of two PhD dissertations. The name of the conference the journal and the dissertations are listed below. - Joint Meeting of the Scandinavian-Nordic and French Sections of the Combustion Institute, Combustion of Char Particles under Oxy-Fuel Conditions...

  10. Cellular processing of gold nanoparticles: CE-ICP-MS evidence for the speciation changes in human cytosol.

    Science.gov (United States)

    Legat, Joanna; Matczuk, Magdalena; Timerbaev, Andrei R; Jarosz, Maciej

    2018-01-01

    The cellular uptake of gold nanoparticles (AuNPs) may (or may not) affect their speciation, but information on the chemical forms in which the particles exist in the cell remains obscure. An analytical method based on the use of capillary electrophoresis hyphenated with inductively coupled plasma mass spectrometry (ICP-MS) has been proposed to shed light on the intracellular processing of AuNPs. It was observed that when being introduced into normal cytosol, the conjugates of 10-50 nm AuNPs with albumin evolved in human serum stayed intact. On the contrary, under simulated cancer cytosol conditions, the nanoconjugates underwent decomposition, the rate of which and the resulting metal speciation patterns were strongly influenced by particle size. The new peaks that appeared in ICP-MS electropherograms could be ascribed to nanosized species, as upon ultracentrifugation, they quantitatively precipitated whereas the supernatant showed only trace Au signals. Our present study is the first step to unravel a mystery of the cellular chemistry for metal-based nanomedicines.

  11. Process for preparing sintered uranium dioxide nuclear fuel

    International Nuclear Information System (INIS)

    Carter, R.E.

    1975-01-01

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

  12. Process and device for fabricating nuclear fuel assembly grids

    International Nuclear Information System (INIS)

    Thiebaut, B.; Duthoo, D.; Germanaz, J.J.; Angilbert, B.

    1991-01-01

    The method for fabricating PWR fuel assembly grids consists to place the grid of which the constituent parts are held firmly in place within a frame into a sealed chamber full of inert gas. This chamber can rotate about an axis. The welding on one face at a time is carried out with a laser beam orthogonal to the axis orientation of the device. The laser source is outside of the chamber and the beam penetrates via a transparent view port

  13. EFFECT OF COMPOSITION OF FUEL CONTAINING BUTANOL ON WORKING PROCESS PARAMETERS OF DIESEL ENGINE

    Directory of Open Access Journals (Sweden)

    D. G. Hershan

    2017-01-01

    Full Text Available Computational researches the effect of composition of fuel containing butanol on working process parameters of 4ЧН 11/12,5 diesel engine on the external speed characteristic have been conducted. Nominal power is 140 kW at engine speed 2300 min–1. The engine is equipped with gas turbine pressure charging with intercooling of charging air, accumulator-type fuel-handling system. Calculations of the working process have been made in accordance with the developed computer program and models. Investigations have been carried out in two stages: without any changes in regulation of fuel-handling system and with cyclic fuel delivery that ensure such value of excess air factor at various operational modes which corresponds to the operation with diesel fuel. All the obtained results have been analyzed in the paper. The paper shows changes in mean indicated pressure, specific indicated fuel consumption, indicated efficiency, specific nitrogen oxides emissions for various modes in question while using 5, 10, 15, 20, 25 and 30 % mixture of diesel fuel with butanol. Dependences of parameters pertaining to diesel operation have been determined according to external speed characteristic for various mixtures and the obtained data make it possible to justify parameters of the fuel-handling system. It has been recommended to use a diesel fuel-butanol mixture containing 15 % of butanol without any changes in regulating and design engine parameters. It has been revealed that in order to improve parameters of the engine operational process mixture composition must be changed while changing the operational mode. An injector nozzle with a compound needle for the fuel-handling system has been developed and it allows to change fuel composition according to engine operational mode.

  14. Entrainer-based reactive distillation versus conventional reactive distillation for the synthesis of fatty acid esters

    NARCIS (Netherlands)

    Jong, de M.C.; Dimian, A.C.; Haan, de A.B.

    2008-01-01

    In this paper different reactive distillation configurations for the synthesis of isopropyl myristate were compared with the use of process models made in Aspen Plus. It can be concluded that the configurations in which an entrainer is added are more capable to reach the required conversion of

  15. Demasking biological oscillators : Properties and principles of entrainment exemplified by the Neurospora circadian clock

    NARCIS (Netherlands)

    Roenneberg, T; Dragovic, Z; Merrow, M; Takahashi, Joseph S.

    2005-01-01

    Oscillations are found throughout the physical and biological worlds. Their interactions can result in a systematic process of synchronization called entrainment, which is distinct from a simple stimulus-response pattern. Oscillators respond to stimuli at some times in their cycle and may not

  16. Savannah River Laboratory monthly report: 238Pu fuel form processes

    International Nuclear Information System (INIS)

    1976-01-01

    Progress in the Savannah River 238 Pu Fuel Form Program is discussed. Goals of the Savannah River Laboratory (SRL) program are to provide technical support for the transfer of the 238 Pu fuel form fabrication operations from Mound Laboratory to new facilities being built at the Savannah River Plant (SRP), to provide the technical basis for 238 Pu scrap recovery at SRP, and to assist in sustaining plant operations. During the period it was found that the density of hot-pressed 238 PuO 2 pellets decreased as the particle size of ball-milled powder decreased;the surface area of calcined 238 PuO 2 powder increased with increasing precipitation temperature and may be related to the variation in ball-milling response observed among different H Area B-Line batches; calcined PuO 2 produced by Pu(III) reverse-strike precipitation was directly fabricated into a pellet without ball milling, slugging, or sharding. The pellet had good appearance with acceptable density and dimensional stability, and heat transfer measurements and calculations showed that the use of hollow aluminum sleeves in the plutonium fuel fabrication (PuFF) storage vault reduced the temperature of shipping cans to 170 0 C and will reduce the temperature at the center of pure plutonium oxide (PPO) spheres to 580 0 C

  17. Three-field modeling with droplet entrainment and de-entrainment models for TRAC-M

    International Nuclear Information System (INIS)

    Lee, Sang Ik

    2005-02-01

    A three-field modeling has been developed and implemented to the basic one-dimensional components of TRAC-M/F90 (Modernized Transient Reactor Analysis Code, Fortran90) to improve the estimation of the behavior of droplet entrainment. the divide and conquer algorithmic technique is adjusted for the implementation after considering the verifications. The governing equations are composed of the conservation equations of each field with thermal-equilibrium assumption between the two liquid fields. As a result, three momentum equations, four mass equations including noncondensable gas mass equation and two energy equations are used. In the development of the momentum equation for an entrained droplet, two different kinds of approaches are tested: the simple force balance on a single droplet and the field-type equation based on the continuum assumption. The first showed unstable nature and the latter was chosen. All of the necessary empirical correlations were obtained from literatures, in particular, the physical models of COBRA-TF. The sensitivities of each empirical correlation were investigated where the effect of droplet diameter and droplet drag was found to be negligible. The advantages of the SETS numerical scheme in comparison with the semi-implicit nimerical scheme were addressed in the simulation time and the maximum allowed time-step size. Finally, the simulations of Collier and Hewitt's experiment were performed and it is concluded that the three-field model developed in the present study is reasonable. The predictions by the present code agree with the measured values within the RMS errors of 16.5% and 9.6% in the entrained liquid mass flow rates and the pressure gradients, respectively. Assessment on the physical models is performed. The wall and interfacial drag models were determined at first. After that, the assessments of entrainment model were performed. Wurtz's entrainment model, which was used in COBRA-TF and Kataoka and Ishii's model, were mainly

  18. Advanced diagnostics in oxy-fuel combustion processes

    Energy Technology Data Exchange (ETDEWEB)

    Brix, J.; Clausen, Soennik; Degn Jensen, A. (Technical Univ. of Denmark. CHEC Research Centre, Kgs. Lyngby (Denmark)); Boeg Toftegaard, M. (DONG Energy Power, Hvidovre (Denmark))

    2012-07-01

    This report sums up the findings in PSO-project 010069, ''Advanced Diagnostics in Oxy-Fuel Combustion Processes''. Three areas of optic diagnostics are covered in this work: - FTIR measurements in a 30 kW swirl burner. - IR measurements in a 30 kW swirl burner. - IR measurements in a laboratory scale fixed bed reactor. The results obtained in the swirl burner have proved the FTIR method as a valuable technique for gas phase temperature measurements. When its efficacy is evaluated against traditional thermocouple measurements, two cases, with and without probe beam stop, must however be treated separately. When the FTIR probe is operated with the purpose of gas phase concentration measurements the probe needs to operate with a beam stop mounted in front of it. With this beam stop in place it was shown that the measured gas phase temperature was affected by cooling, induced by the cooled beam stop. Hence, for a more accurate determination of gas phase temperatures the probe needed to operate without the beam stop. When this was the case, the FTIR probe showed superior to traditional temperature measurements using a thermocouple as it could measure the fast temperature fluctuations. With the beam stop in place the efficacy of the FTIR probe for gas temperature determination was comparable to the use of a traditional thermocouple. The evaluation of the FTIR technique regarding estimation of gas phase concentrations of H{sub 2}O, CO{sub 2} and CO showed that the method is reliable though it cannot be stated as particularly accurate. The accuracy of the method is dependent on the similarity of the reference emission spectra of the gases with those obtained in the experiments, as the transmittance intensity is not a linear function of concentration. The length of the optical path also affects the steadiness of the measurements. The length of the optical path is difficult to adjust on the small scales that are the focus of this work. However

  19. Entrainment in vertical annular two-phase flow

    International Nuclear Information System (INIS)

    Sawant, Pravin; Ishii, Mamoru; Mori, Michitsugu

    2009-01-01

    Prediction of amount of entrained droplets or entrainment fraction in annular two-phase flow is essential for the estimation of dryout condition and analysis of post dryout heat transfer in light water nuclear reactors and steam boilers. In this study, air-water and organic fluid (Freon-113) annular flow entrainment experiments have been carried out in 9.4 and 10.2 mm diameter test sections, respectively. Both the experiments covered three distinct pressure conditions and wide range of liquid and gas flow conditions. The organic fluid experiments simulated high pressure steam-water annular flow conditions. In each of the experiments, measurements of entrainment fraction, droplet entrainment rate and droplet deposition rate have been performed by using a liquid film extraction method. A simple, explicit and non-dimensional correlation developed by Sawant et al. (2008a) for the prediction of entrainment fraction is further improved in this study in order to account for the existence of critical gas and liquid flow rates below which no entrainment is possible. Additionally, a new correlation is proposed for the estimation of minimum liquid film flow rate at the maximum entrainment fraction condition. The improved correlation successfully predicted the newly collected air-water and Freon-113 entrainment fraction data. Furthermore, the correlations satisfactorily compared with the air-water, helium-water and air-genklene experimental data measured by Willetts (1987). (author)

  20. Aerosol entrainment from a sparged non-Newtonian slurry.

    Science.gov (United States)

    Fritz, Brad G

    2006-08-01

    Previous bench-scale experiments have provided data necessary for the development of empirical models that describe aerosol entrainment from bubble bursting. However, previous work has not been extended to non-Newtonian liquid slurries. Design of a waste treatment plant on the Hanford Site in Washington required an evaluation of the applicability of these models outside of their intended range. For this evaluation, aerosol measurements were conducted above an air-sparged mixing tank filled with simulated waste slurry possessing Bingham plastic rheological properties. Three aerosol-size fractions were measured at three sampling heights and for three different sparging rates. The measured entrainment was compared with entrainment models. One model developed based on bench-scale air-water experiments agreed well with measured entrainment. Another model did not agree well with the measured entrainment. It appeared that the source of discrepancy between measured and modeled entrainment stemmed from application beyond the range of data used to develop the model. A possible separation in entrainment coefficients between air-water and steam-water systems was identified. A third entrainment model was adapted to match experimental conditions and fit a posteri to the experimental data, resulting in a modified version that resulted in estimated entrainment rates similar to the first model.

  1. Spent Nuclear Fuel (SNF) Process Validation Technical Support Plan

    Energy Technology Data Exchange (ETDEWEB)

    SEXTON, R.A.

    2000-03-13

    The purpose of Process Validation is to confirm that nominal process operations are consistent with the expected process envelope. The Process Validation activities described in this document are not part of the safety basis, but are expected to demonstrate that the process operates well within the safety basis. Some adjustments to the process may be made as a result of information gathered in Process Validation.

  2. Spent Nuclear Fuel (SNF) Process Validation Technical Support Plan

    International Nuclear Information System (INIS)

    SEXTON, R.A.

    2000-01-01

    The purpose of Process Validation is to confirm that nominal process operations are consistent with the expected process envelope. The Process Validation activities described in this document are not part of the safety basis, but are expected to demonstrate that the process operates well within the safety basis. Some adjustments to the process may be made as a result of information gathered in Process Validation

  3. High liquid fuel yielding biofuel processes and a roadmap for the future transportation

    Science.gov (United States)

    Singh, Navneet R.

    In a fossil-fuel deprived world when crude oil will be scarce and transportation need cannot be met with electricity and transportation liquid fuel must be produced, biomass derived liquid fuels can be a natural replacement. However, the carbon efficiency of the currently known biomass to liquid fuel conversion processes ranges from 35-40%, yielding 90 ethanol gallon equivalents (ege) per ton of biomass. This coupled with the fact that the efficiency at which solar energy is captured by biomass (hydrodeoxygenation is proposed which can achieve liquid fuel yield of 215 ege/ton consuming 0.11 kg hydrogen per liter of oil. Due to the lower hydrogen consumption of the H2Bioil process, synergistically integrated transition pathways are feasible where hot syngas derived from coal gasification (H2Bioil-C) or a natural gas reformer (H 2Bioil-NG) is used to supply the hydrogen and process heat for the biomass fast-hydropyrolysis/hydrodeoxygenation. Another off-shoot of the H2Bioil process is the H2Bioil-B process, where hydrogen required for the hydropyrolysis is obtained from gasification of a fraction of the biomass. H2Bioil-B achieves the highest liquid fuel yield (126-146 ege/ton of biomass) reported in the literature for any self-contained conversion of biomass to biofuel. Finally, an integration of the H2Bioil process with the H2CAR process is suggested which can achieve 100% carbon efficiency (330 ege/ton of biomass) at the expense of 0.24 kg hydrogen/liter of oil. A sun-to-fuel efficiency analysis shows that extracting CO2 from air and converting it to liquid fuel is at least two times more efficient than growing dedicated fuel crops and converting them to liquid fuel even for the highest biomass growth rates feasible by algae. This implies that liquid fuel should preferably be produced from sustainably available waste (SAW) biomass first and if the SAW biomass is unable to meet the demand for liquid fuel, then, CO2 should be extracted from air and converted to

  4. Nuclear fuel cycle, nuclear fuel makes the rounds: choosing a closed fuel cycle, nuclear fuel cycle processes, front-end of the fuel cycle: from crude ore to enriched uranium, back-end of the fuel cycle: the second life of nuclear fuel, and tomorrow: multiple recycling while generating increasingly less waste

    International Nuclear Information System (INIS)

    Philippon, Patrick

    2016-01-01

    France has opted for a policy of processing and recycling spent fuel. This option has already been deployed commercially since the 1990's, but will reach its full potential with the fourth generation. The CEA developed the processes in use today, and is pursuing research to improve, extend, and adapt these technologies to tomorrow's challenges. France has opted for a 'closed cycle' to recycle the reusable materials in spent fuel (uranium and plutonium) and optimise ultimate waste management. France has opted for a 'closed' nuclear fuel cycle. Spent fuel is processed to recover the reusable materials: uranium and plutonium. The remaining components (fission products and minor actinides) are the ultimate waste. This info-graphic shows the main steps in the fuel cycle currently implemented commercially in France. From the mine to the reactor, a vast industrial system ensures the conversion of uranium contained in the ore to obtain uranium oxide (UOX) fuel pellets. Selective extraction, purification, enrichment - key scientific and technical challenges for the teams in the Nuclear Energy Division (DEN). The back-end stages of the fuel cycle for recycling the reusable materials in spent fuel and conditioning the final waste-forms have reached maturity. CEA teams are pursuing their research in support of industry to optimise these processes. Multi-recycle plutonium, make even better use of uranium resources and, over the longer term, explore the possibility of transmuting the most highly radioactive waste: these are the challenges facing future nuclear systems. (authors)

  5. Atenção Pré-Natal no Município de Quixadá-CE segundo indicadores de processo do SISPRENATAL Atención prenatal en el municipio de Quixadá-CE según indicadores de proceso del SISPRENATAL Prenatal care in Quixadá-CE according to SISPRENATAL's process indicators

    Directory of Open Access Journals (Sweden)

    Gisele Ribeiro Grangeiro

    2008-03-01

    Full Text Available Pesquisa descritiva, documental, que objetivou analisar os indicadores de processo do Sistema de Informação do Pré-natal (SISPRENATAL, em Quixadá-CE. Estudaram-se 1.544 cadastros de gestantes no período de 2001 a 2004. Os dados foram coletados de fevereiro a abril de 2005 no SISPRENATAL, implantado no setor de Epidemiologia da Secretaria Municipal de Saúde. Os resultados foram apresentados em tabela única e analisados à luz da literatura atual e experiência acumulada das autoras. Verificou-se percentual crescente de gestantes com indicador de, no mínimo, seis consultas, todos os exames básicos, teste anti-HIV, imunização antitetânica e consulta puerperal de 2001 a 2004, ou seja, zero, 2,6, 5,68 e 21,11%, respectivamente. É necessário, pois, uma melhora na utilização do Sistema, assim como a leitura sistemática dos indicadores de processo, no sentido de obter subsídios para a melhoria da qualidade da assistência pré-natal.En esta Investigación descriptiva, documental se tuvo como objetivo analizar los indicadores de proceso del Sistema de Información del Prenatal (SISPRENATAL, el el municipio de Quixadá-CE. Fueron estudiados 1.544 registros de mujeres embarazadas en el período de 2001 a 2004. Los datos fueron recolectados de febrero a abril del 2005 en el SISPRENATAL, en el sector de Epidemiología de la Secretaría Municipal de Salud. Los resultados fueron presentados sólo en una tabla y analizados a la luz de la literatura actual y también a partir de las experiencias de las autoras. Se verificó el porcentaje creciente de mujeres embarazadas con indicador mínimo de seis consultas, todos los exámenes básicos, test anti-VIH, inmunización antitetánica y consulta puerperal de 2001 a 2004, es decir, cero, 2,6, 5,68 e 21,11%, respectivamente. Es necesario, pues, una mejor utilización del Sistema, y también una lectura sistemática de los indicadores de proceso para obtener soporte para la mejoría de la calidad de

  6. The Role of Oscillatory Phase in Determining the Temporal Organization of Perception: Evidence from Sensory Entrainment.

    Science.gov (United States)

    Ronconi, Luca; Melcher, David

    2017-11-01

    Recent behavioral, neuroimaging, and neurophysiological studies have renewed the idea that the information processing within different temporal windows is linked to the phase and/or frequency of the ongoing oscillations, predominantly in the theta/alpha band (∼4-7 and 8-12 Hz, respectively). However, being correlational in nature, this evidence might reflect a nonfunctional byproduct rather than having a causal role. A more direct link can be shown with methods that manipulate oscillatory activity. Here, we used audiovisual entrainment at different frequencies in the prestimulus period of a temporal integration/segregation task. We hypothesized that entrainment would align ongoing oscillations and drive them toward the stimulation frequency. To reveal behavioral oscillations in temporal perception after the entrainment, we sampled the segregation/integration performance densely in time. In Experiment 1, two groups of human participants (both males and females) received stimulation either at the lower or the upper boundary of the alpha band (∼8.5 vs 11.5 Hz). For both entrainment frequencies, we found a phase alignment of the perceptual oscillation across subjects, but with two different power spectra that peaked near the entrainment frequency. These results were confirmed when perceptual oscillations were characterized in the time domain with sinusoidal fittings. In Experiment 2, we replicated the findings in a within-subject design, extending the results for frequencies in the theta (∼6.5 Hz), but not in the beta (∼15 Hz), range. Overall, these findings show that temporal segregation can be modified by sensory entrainment, providing evidence for a critical role of ongoing oscillations in the temporal organization of perception. SIGNIFICANCE STATEMENT The continuous flow of sensory input is not processed in an analog fashion, but rather is grouped by the perceptual system over time. Recent studies pinpointed the phase and/or frequency of the neural

  7. A study on the manufacturing and processing technologies of DUPIC fuel

    International Nuclear Information System (INIS)

    Yang, Myung Seung; Park, J.J.; Lee, J.W.; Kim, S.S.; Yim, S.P.; Kim, J.H.; Kim, K.H.; Na, S.H.; Kim, W.K.; Kang, K.H.; Shin, J.M.; Lee, D.Y.; Cho, K.H.; Lee, Y.S.; Sohn, J.S.; Kim, M.J.

    1999-06-01

    In this study, DUPIC fuel fabrication technologies are developed, characteristics of fuel materials are studied, and characterization experiments for DUPIC powder and pellets are performed at PIEF. SIMFUEL powder and pellets are made of UO 2 mixed with the simulated fission products of spent fuel. Both characteristics of SIMFUEL powder and micro-structure of pellets are analyzed. End cap of DUPIC fuel rod is sealed with laser welding technique. Optimum welding condition is analyzed with results of Micro-hardness, mechanical and metallographic tests. Micro-focus x-ray inspection technique is studied to fine fine defects. DUPIC processes are improved by making OREOX process be multi-functional and by adopting rol compacting process. At PIEF, characterization experiments for DUPIC powder and pellet are performed. The equipment for experiments have been installed at PIEF no. 9405 hot cell, and its process parameters are established. (author). 7 refs., 7 tabs., 37 figs

  8. Solid recovered fuel: influence of waste stream composition and processing on chlorine content and fuel quality.

    Science.gov (United States)

    Velis, Costas; Wagland, Stuart; Longhurst, Phil; Robson, Bryce; Sinfield, Keith; Wise, Stephen; Pollard, Simon

    2012-02-07

    Solid recovered fuel (SRF) produced by mechanical-biological treatment (MBT) of municipal waste can replace fossil fuels, being a CO(2)-neutral, affordable, and alternative energy source. SRF application is limited by low confidence in quality. We present results for key SRF properties centered on the issue of chlorine content. A detailed investigation involved sampling, statistical analysis, reconstruction of composition, and modeling of SRF properties. The total chlorine median for a typical plant during summer operation was 0.69% w/w(d), with lower/upper 95% confidence intervals of 0.60% w/w(d) and 0.74% w/w(d) (class 3 of CEN Cl indicator). The average total chlorine can be simulated, using a reconciled SRF composition before shredding to limit for ash content marginally below the 20% w/w(d) deemed suitable for certain power plants; and a lower 95% confidence limit of net calorific value (NCV) at 14.5 MJ kg(ar)(-1). The data provide, for the first time, a high level of confidence on the effects of SRF composition on its chlorine content, illustrating interrelationships with other fuel properties. The findings presented here allow rational debate on achievable vs desirable MBT-derived SRF quality, informing the development of realistic SRF quality specifications, through modeling exercises, needed for effective thermal recovery.

  9. Development of the vacuum drying process for the PWR spent nuclear fuel dry storage

    Energy Technology Data Exchange (ETDEWEB)

    Baeg, Chagn Yeal; Cho, Chun Hyung [Korea Radioactive Waste Agency, Daejeon (Korea, Republic of)

    2016-12-15

    This paper describes the development of a dry operation process for PWR spent nuclear fuel, which is currently stored in the domestic NPP's storage pool, using a dual purpose metal cask. Domestic NNPs have had experience with wet type transportation of PWR spent nuclear fuel between neighboring NPPs since the early 1990s, but no experience with dry type operation. For this reason, we developed a specific operation process and also confirmed the safety of the major cask components and its spent nuclear fuel during the dual purpose metal cask operation process. We also describe the short term operation process that was established to be completed within 21 hours and propose the allowable working time for each step (15 hours for wet process, 3 hours for drain process and 3 hours for vacuum drying process)

  10. Development of the spent fuel disassembling process by utilizing the 3D graphic design technology

    International Nuclear Information System (INIS)

    Song, T. K.; Lee, J. Y.; Kim, S. H.; Yun, J. S.

    2001-01-01

    For developing the spent fuel disassembling process, the 3D graphic simulation has been established by utilizing the 3D graphic design technology which is widely used in the industry. The spent fuel disassembling process consists of a downender, a rod extraction device, a rod cutting device, a pellet extracting device and a skeleton compaction device. In this study, the 3D graphical design model of these devices is implemented by conceptual design and established the virtual workcell within kinematics to motion of each device. By implementing this graphic simulation, all the unit process involved in the spent fuel disassembling processes are analyzed and optimized. The 3D graphical model and the 3D graphic simulation can be effectively used for designing the process equipment, as well as the optimized process and maintenance process

  11. The GC computer code for flow sheet simulation of pyrochemical processing of spent nuclear fuels

    International Nuclear Information System (INIS)

    Ahluwalia, R.K.; Geyer, H.K.

    1996-01-01

    The GC computer code has been developed for flow sheet simulation of pyrochemical processing of spent nuclear fuel. It utilizes a robust algorithm SLG for analyzing simultaneous chemical reactions between species distributed across many phases. Models have been developed for analysis of the oxide fuel reduction process, salt recovery by electrochemical decomposition of lithium oxide, uranium separation from the reduced fuel by electrorefining, and extraction of fission products into liquid cadmium. The versatility of GC is demonstrated by applying the code to a flow sheet of current interest

  12. Evaluation of alternative fuels for the Greek road transport sector using the analytic hierarchy process

    International Nuclear Information System (INIS)

    Tsita, Katerina G.; Pilavachi, Petros A.

    2012-01-01

    This paper evaluates alternative fuels for the Greek road transport sector, using the Analytic Hierarchy Process. Seven different alternatives of fuel mode are considered in this paper: internal combustion engine (ICE) and its combination with petroleum and 1st and 2nd generation biofuels blends, fuel cells, hybrid vehicles, plug-in hybrids and electric vehicles. The evaluation of alternative fuel modes is performed according to cost and policy aspects. In order to evaluate each alternative fuel, one base scenario and ten alternative scenarios with different weight factors selection per criterion are presented. After deciding the alternative fuels’ scoring against each criterion and the criteria weights, their synthesis gives the overall score and ranking for all ten alternative scenarios. It is concluded that ICE blended with 1st and 2nd generation biofuels are the most suitable alternative fuels for the Greek road transport sector. - Highlights: ► Alternative fuels for the Greek road transport sector have been evaluated. ► The method of the AHP was used. ► Seven different alternatives of fuel mode are considered. ► The evaluation is performed according to cost and policy aspects. ► The ICE with 1st and 2nd generation biofuels are the most suitable fuels.

  13. CONCEPTUAL DESIGN OF NON-IDEAL MIXTURE SEPARATION WITH LIGHT ENTRAINERS

    Directory of Open Access Journals (Sweden)

    W. Shen

    Full Text Available Abstract A method is proposed to study the separation of minimum-, maximum-boiling azeotropic, and low volatility mixtures with a light entrainer, to investigate feasible regions of the key operating parameters reboil ratio (S and entrainer - feed flowrate ratio (FE/F for continuous processes. The thermodynamic topological predictions are carried out for 1.0-2, 1.0-1a, and 0.0-1 Serafimov's class diagrams. It relies upon the knowledge of residue curve maps, along with the univolatility line, and it enables the prediction of possible products at the bottom of the column and limiting values of FE/F. The profiles of the stripping, extractive, and rectifying sections are calculated by equations considering S and FE/F, and they bring information about the location of singular points and possible composition profile separatrices that could impair process feasibility. Providing specified product composition and recovery, the approximate calculations are compared with rigorous simulations of extractive distillation processes. Separating non-ideal mixtures using a light entrainer provides more opportunities for the case when it is not easy to find an appropriate heavy or intermediate entrainer.

  14. High performance Ni-Sm{sub 0.15}Ce{sub 0.85}O{sub 2-{delta}} cermet anodes for intermediate temperature solid oxide fuel cells using LaGaO{sub 3} based oxide electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Shizhong; Takita, Yusaku [Department of Applied Chemistry, Faculty of Engineering, Oita University, Dannoharu 700, Oita 870-1192 (Japan); Ando, Masaki [Materials Production Course, Graduate School of Engineering, Oita University, Dannoharu 700, Oita 870-1192 (Japan); Ishihara, Tatsumi [Department of Applied Chemistry, Faculty of Engineering, Kyushu University, Hakozaki 6-10-1, Higashi-ku, Fukuoka 812-8581 (Japan)

    2004-10-29

    Effect of the composition and synthesizing approaches on the performance of Ni-15 mol% Sm{sup 3+} doped CeO{sub 2} (Sm{sub 0.15}Ce{sub 0.85}O{sub 2-{delta}}, SDC) composite anodes were studied. The results showed that the addition of SDC into Ni significantly improved the performance of Ni anode mainly by reducing the ohmic resistance of the cell and the overpotential at anode/electrolyte interface. The introduction of SDC into Ni created more active sites for H{sub 2} oxidation; however, it also increased the activation energy of the process at the same time. Therefore, the anodic overpotential of Ni-SDC composite electrode was higher than pure Ni at low reaction temperatures (873 K), while lower than that of pure Ni at 1073 K. Further experiments showed that the activities of Ni-SDC composite electrodes showed strong dependency on the synthesizing approaches. The electrodes prepared with impregnation methods exhibited a much higher activity compared with the electrodes prepared with solid-state reaction due to the reduced ohmic resistance. The low ohmic resistance of the cells using Ni-SDC anodes prepared with impregnation method is due to the improved distribution of Ni and SDC in the green powder of anode. An equal distribution of Ni and SDC is essential to minimize the reaction between Ni and strontium and magnesium doped lanthanum gallate (LSGM), and decrease the ohmic resistance.

  15. Analysis of irradiated U-7wt%Mo dispersion fuel microstructures using automated image processing

    Energy Technology Data Exchange (ETDEWEB)

    Collette, R. [Colorado School of Mines, Nuclear Science and Engineering Program, 1500 Illinois St, Golden, CO 80401 (United States); King, J., E-mail: kingjc@mines.edu [Colorado School of Mines, Nuclear Science and Engineering Program, 1500 Illinois St, Golden, CO 80401 (United States); Buesch, C. [Oregon State University, 1500 SW Jefferson St., Corvallis, OR 97331 (United States); Keiser, D.D.; Williams, W.; Miller, B.D.; Schulthess, J. [Nuclear Fuels and Materials Division, Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415-6188 (United States)

    2016-07-15

    The High Performance Research Reactor Fuel Development (HPPRFD) program is responsible for developing low enriched uranium (LEU) fuel substitutes for high performance reactors fueled with highly enriched uranium (HEU) that have not yet been converted to LEU. The uranium-molybdenum (U-Mo) fuel system was selected for this effort. In this study, fission gas pore segmentation was performed on U-7wt%Mo dispersion fuel samples at three separate fission densities using an automated image processing interface developed in MATLAB. Pore size distributions were attained that showed both expected and unexpected fission gas behavior. In general, it proved challenging to identify any dominant trends when comparing fission bubble data across samples from different fuel plates due to varying compositions and fabrication techniques. The results exhibited fair agreement with the fission density vs. porosity correlation developed by the Russian reactor conversion program. - Highlights: • Automated image processing is used to extract fission gas bubble data from irradiated U−Mo fuel samples. • Verification and validation tests are performed to ensure the algorithm's accuracy. • Fission bubble parameters are predictably difficult to compare across samples of varying compositions. • The 2-D results suggest the need for more homogenized fuel sampling in future studies. • The results also demonstrate the value of 3-D reconstruction techniques.

  16. Chemical processing of HTR fuels applying either THOREX or PUREX flow sheets

    Energy Technology Data Exchange (ETDEWEB)

    Zimmer, E; Merz, E [Kernforschungsanlage, Juelich GmbH, Institut fuer Chemische Technologie der Nuklearen Entsorgung, Juelich (Germany)

    1985-07-01

    Two fuel cycles are considered for utilization in high temperature gas-cooled reactors (HTRs): the high-enriched thorium-uranium (HEU 93% U-235) and the low-enriched uranium (LEU 8-12% U-235) fuel concept. For both fuel compositions suitable reprocessing procedures are required which are capable to separate the actinides thorium, uranium and plutonium from fission products and from each other. In any case, the processes under consideration utilize Tri-n-butylphosphate (TBP) together with a straight-chain paraffinic diluent (C{sub 8}-C{sub 14}, to day usually dodecane) as extractant in an aqueous nitrate system; most commonly, the related processes are known by the acronyms PUREX and THOREX. The PUREX process has become the reprocessing procedure quite generally used for all fuel types containing natural, slightly or highly enriched uranium together with lower or higher contents of plutonium. The THOREX process on the other hand has been developed to separate thorium, uranium and fission products from thorium based irradiated fuel. Generally, the utilization of the thorium fuel cycle is most attractive for High Temperature Reactors. On the other hand, the strong recommendation of INFCE to abandon the use of high-enriched uranium for nuclear energy applications virtually rules out the thorium fuel cycle, since economic utilization of thorium as a fertile material requires the use of high-enriched U-235. Thus, it was decided in the Federal Republic of Germany to switch over, at least for the foreseeable future, to the low enrichment uranium-plutonium fuel cycle, well aware of its economic shortcomings. In this paper various THOREX flowsheets as well as a PUREX variant suitable for LEU fuel reprocessing are described. Both processes have in common that the main stream is always presented by the fertile material, that means thorium and U-238, respectively.

  17. Apparatus and process for separating end of nuclear fuel assembly

    International Nuclear Information System (INIS)

    Beneck, J.A.; Quayre, C.; Moreau, J.R.M.; Vermeille, D.E.A.

    1989-01-01

    The apparatus for cutting the guide tubes of a nuclear fuel assembly below the bottom nozzle has a framework with removable fixation and centering means on the bottom nozzle. Cutting devices in the form of hollow pins are inserted simultaneously into all the guide tubes. Each pin contains a shaft that is moved axially inside it by the expansion system to deploy or retract a cutting edge near the lower end of the pin. A single motor using a gear wheel system, rotates all the cutting pins simultaneously [fr

  18. Air plasma spray processing and electrochemical characterization of Cu-SDC coatings for use in solid oxide fuel cell anodes

    Energy Technology Data Exchange (ETDEWEB)

    Benoved, Nir [Department of Mechanical Engineering, The University of British Columbia, 2054-6250 Applied Sciences Lane, Vancouver, British Columbia (Canada); Kesler, O. [Department of Mechanical and Industrial Engineering, University of Toronto, 5 King' s College Road, Toronto, Ontario (Canada)

    2009-09-05

    Air plasma spraying has been used to produce porous composite anodes based on Ce{sub 0.8}Sm{sub 0.2}O{sub 1.9} (SDC) and Cu for use in solid oxide fuel cells (SOFCs). Preliminarily, a range of plasma conditions has been examined for the production of composite coatings from pre-mixed SDC and CuO powders. Plasma gas compositions were varied to obtain a range of plasma temperatures. After reduction in H{sub 2}, coatings were characterized for composition and microstructure using EDX and SEM. As a result of these tests, symmetrical sintered electrolyte-supported anode-anode cells were fabricated by air plasma spraying of the anodes, followed by in situ reduction of the CuO to Cu. Full cells deposited on SS430 porous substrates were then produced in one integrated process. Fine CuO and SDC powders have been used to produce homogeneously mixed anode coatings with higher surface area microstructures, resulting in area-specific polarization resistances of 4.8 {omega} cm{sup 2} in impedance tests in hydrogen at 712 C. (author)

  19. Air plasma spray processing and electrochemical characterization of Cu-SDC coatings for use in solid oxide fuel cell anodes

    Science.gov (United States)

    Benoved, Nir; Kesler, O.

    Air plasma spraying has been used to produce porous composite anodes based on Ce 0.8Sm 0.2O 1.9 (SDC) and Cu for use in solid oxide fuel cells (SOFCs). Preliminarily, a range of plasma conditions has been examined for the production of composite coatings from pre-mixed SDC and CuO powders. Plasma gas compositions were varied to obtain a range of plasma temperatures. After reduction in H 2, coatings were characterized for composition and microstructure using EDX and SEM. As a result of these tests, symmetrical sintered electrolyte-supported anode-anode cells were fabricated by air plasma spraying of the anodes, followed by in situ reduction of the CuO to Cu. Full cells deposited on SS430 porous substrates were then produced in one integrated process. Fine CuO and SDC powders have been used to produce homogeneously mixed anode coatings with higher surface area microstructures, resulting in area-specific polarization resistances of 4.8 Ω cm 2 in impedance tests in hydrogen at 712 °C.

  20. The effect of low-NOx combustion on residual carbon in fly ash and its adsorption capacity for air entrainment admixtures in concrete

    DEFF Research Database (Denmark)

    Pedersen, Kim Hougaard; Jensen, Anker Degn; Dam-Johansen, Kim

    2010-01-01

    been combusted in an entrained flow reactor to test the impact of changes in operating conditions and fuel type on the AEA adsorption of ash and NOx formation. Increased oxidizing conditions, obtained by improved fuel-air mixing or higher excess air, decreased the AEA requirements of the produced ash......Fly ash from pulverized coal combustion contains residual carbon that can adsorb the air-entraining admixtures (AEAs) added to control the air entrainment in concrete. This is a problem that has increased by the implementation of low-NOx combustion technologies. In this work, pulverized fuel has...... by up to a factor of 25. This was due to a lower carbon content in the ash and a lower specific AEA adsorptivity of the carbon. The latter was suggested to be caused by changes in the adsorption properties of the unburned char and a decreased formation of soot, which was found to have a large AEA...

  1. Review of the literature for dry reprocessing oxide, metal, and carbide fuel: The AIROX, RAHYD, and CARBOX pyrochemical processes

    Energy Technology Data Exchange (ETDEWEB)

    Hoyt, R.C.; Rhee, B.W. [Rockwell International Corp., Canoga Park, CA (United States). Energy Systems Group

    1979-09-30

    The state of the art of dry processing oxide, carbide, and metal fuel has been determined through an extensive literature review. Dry processing in one of the most proliferation resistant fuel reprocessing technologies available to date, and is one of the few which can be exported to other countries. Feasibility has been established for oxide, carbide, and metal fuel on a laboratory scale, and large-scale experiments on oxide and carbide fuel have shown viability of the dry processing concept. A complete dry processing cycle has been demonstrated by multicycle processing-refabrication-reirradiation experiments on oxide fuel. Additional experimental work is necessary to: (1) demonstrate the complete fuel cycle for carbide and metal fuel, (2) optimize dry processing conditions, and (3) establish fission product behavior. Dry process waste management is easier than for an aqueous processing facility since wastes are primarily solids and gases. Waste treatment can be accomplished by techniques which have been, or are being, developed for aqueous plants.

  2. Numerical Studies on Controlling Gaseous Fuel Combustion by Managing the Combustion Process of Diesel Pilot Dose in a Dual-Fuel Engine

    Directory of Open Access Journals (Sweden)

    Mikulski Maciej

    2015-06-01

    Full Text Available Protection of the environment and counteracting global warming require finding alternative sources of energy. One of the methods of generating energy from environmentally friendly sources is increasing the share of gaseous fuels in the total energy balance. The use of these fuels in compression-ignition (CI engines is difficult due to their relatively high autoignition temperature. One solution for using these fuels in CI engines is operating in a dualfuel mode, where the air and gas mixture is ignited with a liquid fuel dose. In this method, a series of relatively complex chemical processes occur in the engine's combustion chamber, related to the combustion of individual fuel fractions that interact with one another. Analysis of combustion of specific fuels in this type of fuel injection to the engine is difficult due to the fact that combustion of both fuel fractions takes place simultaneously. Simulation experiments can be used to analyse the impact of diesel fuel combustion on gaseous fuel combustion. In this paper, we discuss the results of simulation tests of combustion, based on the proprietary multiphase model of a dual-fuel engine. The results obtained from the simulation allow for analysis of the combustion process of individual fuels separately, which expands the knowledge obtained from experimental tests on the engine.

  3. Development of cables for nuclear fuel processing facilities

    International Nuclear Information System (INIS)

    Kamimura, Seiji; Seki, Ikuo; Yamamoto, Yasuaki; Matsuyama, Shigeki; Endo, Shigeru; Yagi, Toshiaki; Kawakami, Waichiro.

    1988-01-01

    Accompanying the development of nuclear power stations, the expansion and repletion of the facilities for nuclear fuel cycle such as fuel reprocessing facilities and waste treatment facilities are requested. In these facilities, there is the environment which is exposed to very high level radiation, and in this case, the cables withstanding 10 MGy radiation dose are required. As the cables meeting such requirement, the new cables having excellent flexibility and radiation resistance were developed. In this paper, the points of material development and the characteristics of cables are reported. Considering the radiation resistance and others, ethylene propylene rubber was selected as the base polymer of the insulator, and polyethylene chlorosulfonate was selected as the sheath material. In order to give excellent radiation resistance, as the anti-rad, energy transfer type aromatic oil that absorbs and dissipates radiation energy and radical trap type anti-oxidant of amine group that catches and stabilizes the radicals generated in the polymer were added. The bromine group burning retarding agent having excellent radiation resistance was applied. In this way, the cables withstanding high radiation dose up to 10 MGy were able to be developed. (K.I.)

  4. Fuel ethanol production from lignocellulose: a challenge for metabolic engineering and process integration

    DEFF Research Database (Denmark)

    Zaldivar, Jesus; Nielsen, Jens; Olsson, Lisbeth

    2001-01-01

    and with the implementation of environmental protection laws in many countries, demand for this fuel is increasing. Efficient ethanol production processes and cheap substrates are needed. Current ethanol production processes using crops such as sugar cane and corn are well-established; however, utilization of a cheaper...... substrate such as lignocellulose could make bioethanol more competitive with fossil fuel. The processing and utilization of this substrate is complex, differing, in many aspects from crop-based ethanol production. One important requirement is an efficient microorganism able to ferment a variety of sugars......With industrial development growing rapidly, there is a need for environmentally sustainable energy sources. Bioethanol (ethanol from biomass) is an attractive, sustainable energy source to fuel transportation. Based on the premise that fuel bioethanol can contribute to a cleaner environment...

  5. Hydrodeoxygenation processes: advances on catalytic transformations of biomass-derived platform chemicals into hydrocarbon fuels.

    Science.gov (United States)

    De, Sudipta; Saha, Basudeb; Luque, Rafael

    2015-02-01

    Lignocellulosic biomass provides an attractive source of renewable carbon that can be sustainably converted into chemicals and fuels. Hydrodeoxygenation (HDO) processes have recently received considerable attention to upgrade biomass-derived feedstocks into liquid transportation fuels. The selection and design of HDO catalysts plays an important role to determine the success of the process. This review has been aimed to emphasize recent developments on HDO catalysts in effective transformations of biomass-derived platform molecules into hydrocarbon fuels with reduced oxygen content and improved H/C ratios. Liquid hydrocarbon fuels can be obtained by combining oxygen removal processes (e.g. dehydration, hydrogenation, hydrogenolysis, decarbonylation etc.) as well as by increasing the molecular weight via C-C coupling reactions (e.g. aldol condensation, ketonization, oligomerization, hydroxyalkylation etc.). Fundamentals and mechanistic aspects of the use of HDO catalysts in deoxygenation reactions will also be discussed. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Progress on matrix SiC processing and properties for fully ceramic microencapsulated fuel form

    International Nuclear Information System (INIS)

    Terrani, K.A.; Kiggans, J.O.; Silva, C.M.; Shih, C.; Katoh, Y.; Snead, L.L.

    2015-01-01

    The consolidation mechanism and resulting properties of the silicon carbide (SiC) matrix of fully ceramic microencapsulated (FCM) fuel form are discussed. The matrix is produced via the nano-infiltration transient eutectic-forming (NITE) process. Coefficient of thermal expansion, thermal conductivity, and strength characteristics of this SiC matrix have been characterized in the unirradiated state. An ad hoc methodology for estimation of thermal conductivity of the neutron-irradiated NITE–SiC matrix is also provided to aid fuel performance modeling efforts specific to this concept. Finally, specific processing methods developed for production of an optimal and reliable fuel form using this process are summarized. These various sections collectively report the progress made to date on production of optimal FCM fuel form to enable its application in light water and advanced reactors

  7. Stability of La0.6Sr0.4Co0.2Fe0.8O3/Ce0.9Gd0.1O2 cathodes during sintering and solid oxide fuel cell operation

    DEFF Research Database (Denmark)

    Kiebach, Ragnar; Zhang, Weiwei; Zhang, Wei

    2015-01-01

    Degradation phenomena of La0.58Sr0.4Co0.2Fe0.8O3/Ce0.9Gd0.1O2 (LSCF/CGO) cathodes were investigated via post-mortem analyses of an experimental solid oxide fuel cell (SOFC) stack tested at 700 °C for 2000 h using advanced electron microscopy (SEM-EDS, HR-TEM-EDS) and time-of-flight secondary ion...... mass spectrometry (TOF-SIMS). Similar studies were carried out on non-tested reference cells for comparison. The analysis focused on the LSCF/CGO cathode and the CGO barrier layer, as the cathode degradation can be a major contributor to the overall degradation in this type of SOFC. SEM-EDS and TOF......-SIMS were used to investigate inter-diffusion across the barrier layer - electrolyte interface and the barrier layer - cathode interface. In addition, TOF-SIMS data were employed to investigate impurity distribution before and after testing. HR-TEM-EDS was used to investigate possible phase segregation...

  8. EFFECT OF RHODIUM INFILTRATION ON THE MICROSTRUCTURE AND PERFORMANCE OF Ni/Ce0.8Gd0.2O2-δ CERMET ANODE FOR LOW TEMPERATURE SOLID OXIDE FUEL CELL

    Directory of Open Access Journals (Sweden)

    F. Torknik

    2016-03-01

    Full Text Available In order to further enhance the Ni/Ce 0.8Gd0.2O2-δ (Ni/GDC20 cermet anodic performance for low temperature solid oxide fuel cell (LT-SOFC, a study was conducted on the nanostructuring of NiO/GDC composite by only once wet-infiltration of rhodium chloride precursor. By using electrochemical impedance spectroscopy (EIS analysis, the effect of only one drop of Rh-infiltrating solution on the anodic polarization resistance was examined using symmetric Ni–GDC20|GDC20|Pt electrolyte-supported cell at 400-600 °C. Nanostructural evolution before and after H 2 reduction at 600 °C and also after anodic performance test was investigated by atomic force microscopy (AFM, field emission scanning electron microscopy (FE-SEM, and transmission electron microscopy (TEM techniques in comparison to the anode itself. Despite the fine distribution of Rh-infiltrated nanoparticles having average particle size of 11.7 nm, the results showed ineffectiveness and inability of the Rh nanoparticles to succeed in decreasing of anodic polarization resistance for H 2 oxidation reaction in LT-SOFC.

  9. Diversion-resistant nuclear-fuels processing. Progress report, 1980-1981

    International Nuclear Information System (INIS)

    Tomlinson, R.E.; Campbell, M.H.; Hansen, L.E.; Jaech, J.L.; Merker, L.G.; Malody, C.W.; Nilson, R.; Schneider, R.A.

    1983-01-01

    Design objectives for the projected colocated facilities were formulated. An assessment methodology, was developed. As a baseline, the modified Delphi procedure was used to evaluate the most recent US designs of a fuel reprocessing plant and a fuels refabrication plant against the identified regulations and goals. An upgraded design concept was synthesized, using the baseline fuel reprocessing plant design as a starting point but using a new design concept for fuel conversion and refabrication. The modified Delphi procedure was used to evaluate the upgrading design concepts against identified regulations and goals. The upgraded portions, product conversion, fuel fabrication, and laboratory received ratings of 95% or higher compared with ratings of about 60% for the baseline designs. Alternative reprocessing and refabrication processes were evaluated to determine if any process could offer an inherent safeguards advantage over the combination included in the upgraded design concept. Tentative conclusions reached are: A combination of a modified Purex solvent extraction fuel reprocessing and a Sphere-Pac fuel fabrication flowsheet, coupled with an improved measurement system and a rapid draw-down inventory procedure, can provide the means for meeting most NRC and IAEA Goals. Given industry and DOE support, fuels fabricated by the Sphere-Pac process can probably be licensed by 1990. With a modest demonstration effort, the processes and equipment modifications envisioned can be ready for incorporation in a detailed design by 1985. Practical techniques and equipment are available for the assured control of the movement of plutonium and personnel into and out of the plant and between plant segments. The incremental cost of facilities and procedures needed to provide the above capabilities would probably increase the unit cost of fuel reprocessing and conversion by 5 to 10%

  10. Powder metallurgy and fabricating processes of cermet and metmet fuel in Russia

    International Nuclear Information System (INIS)

    Vatulin, A.; Konovalov, I.; Savchenco, A.; Stetsky, Y.; Trifonov, Y.; Bochvar, A.A.

    2000-01-01

    Methods of powder metallurgy are widely used for manufacturing of various components of reactor core: beryllium reflectors, absorbers, parts of controlling and safety systems, fuel pellets for fuel elements of power reactors and etc. The new problems arising before atomic engineering associated with increasing requirements to safe operation of reactors, non-proliferation of the nuclear weapons and utilization of plutonium stockpile in the world, served as a push to development of new kinds of dispersion nuclear fuel CERMET, CERCER, METMET. The bases of fabricating processes of such compositions are the methods of powder metallurgy. In this report some results of research activities on the development of new kinds of CERMET and METMET fuel and fuel elements for different type reactors are presented. (author)

  11. Simulation of spent fuel reprocessing processes: Realizations and prospects

    International Nuclear Information System (INIS)

    Boullis, B.

    1986-12-01

    The separation of uranium and plutonium in the Purex process is very complex and for the extension of reprocessing plants optimization of the process requires mathematical modelling. The development of this model is reviewed [fr

  12. Promoting effect of CeO 2 on cyclohexanol conversion over CeO 2

    Indian Academy of Sciences (India)

    Abstract. CeO2-ZnO materials were prepared by amorphous citrate process and characterized by TGA, XRD, UV-DRS and surface area measurements. TGA showed that the citrate precursors decompose in the range 350-550°C producing CeO2-containing catalytic materials. XRD and DRS results indicated the formation of ...

  13. Out-of-synchrony speech entrainment in developmental dyslexia.

    Science.gov (United States)

    Molinaro, Nicola; Lizarazu, Mikel; Lallier, Marie; Bourguignon, Mathieu; Carreiras, Manuel

    2016-08-01

    Developmental dyslexia is a reading disorder often characterized by reduced awareness of speech units. Whether the neural source of this phonological disorder in dyslexic readers results from the malfunctioning of the primary auditory system or damaged feedback communication between higher-order phonological regions (i.e., left inferior frontal regions) and the auditory cortex is still under dispute. Here we recorded magnetoencephalographic (MEG) signals from 20 dyslexic readers and 20 age-matched controls while they were listening to ∼10-s-long spoken sentences. Compared to controls, dyslexic readers had (1) an impaired neural entrainment to speech in the delta band (0.5-1 Hz); (2) a reduced delta synchronization in both the right auditory cortex and the left inferior frontal gyrus; and (3) an impaired feedforward functional coupling between neural oscillations in the right auditory cortex and the left inferior frontal regions. This shows that during speech listening, individuals with developmental dyslexia present reduced neural synchrony to low-frequency speech oscillations in primary auditory regions that hinders higher-order speech processing steps. The present findings, thus, strengthen proposals assuming that improper low-frequency acoustic entrainment affects speech sampling. This low speech-brain synchronization has the strong potential to cause severe consequences for both phonological and reading skills. Interestingly, the reduced speech-brain synchronization in dyslexic readers compared to normal readers (and its higher-order consequences across the speech processing network) appears preserved through the development from childhood to adulthood. Thus, the evaluation of speech-brain synchronization could possibly serve as a diagnostic tool for early detection of children at risk of dyslexia. Hum Brain Mapp 37:2767-2783, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  14. Bioelectricity Generation and Bioremediation of an Azo-Dye in a Microbial Fuel Cell Coupled Activated Sludge Process

    Science.gov (United States)

    Khan, Mohammad Danish; Abdulateif, Huda; Ismail, Iqbal M.; Sabir, Suhail; Khan, Mohammad Zain

    2015-01-01

    Simultaneous bioelectricity generation and dye degradation was achieved in the present study by using a combined anaerobic-aerobic process. The anaerobic system was a typical single chambered microbial fuel cell (SMFC) which utilizes acid navy blue r (ANB) dye along with glucose as growth substrate to generate electricity. Four different concentrations of ANB (50, 100, 200 and 400 ppm) were tested in the SMFC and the degradation products were further treated in an activated sludge post treatment process. The dye decolorization followed pseudo first order kinetics while the negative values of the thermodynamic parameter ∆G (change in Gibbs free energy) shows that the reaction proceeds with a net decrease in the free energy of the system. The coulombic efficiency (CE) and power density (PD) attained peak values at 10.36% and 2,236 mW/m2 respectively for 200 ppm of ANB. A further increase in ANB concentrations results in lowering of cell potential (and PD) values owing to microbial inhibition at higher concentrations of toxic substrates. Cyclic voltammetry studies revealed a perfect redox reaction was taking place in the SMFC. The pH, temperature and conductivity remain 7.5–8.0, 27(±2°C and 10.6–18.2 mS/cm throughout the operation. The biodegradation pathway was studied by the gas chromatography coupled with mass spectroscopy technique, suggested the preferential cleavage of the azo bond as the initial step resulting in to aromatic amines. Thus, a combined anaerobic-aerobic process using SMFC coupled with activated sludge process can be a viable option for effective degradation of complex dye substrates along with energy (bioelectricity) recovery. PMID:26496083

  15. Liquid waste processing from TRIGA spent fuel storage pits

    International Nuclear Information System (INIS)

    Buchtela, Karl

    1988-01-01

    At the Atominstitute of the Austrian Universities and also at other facilities running TRIGA reactors, storage pits for spent fuel elements are installed. During the last revision procedure, the reactor group of the Atominstitute decided to refill the storage pits and to get rid of any contaminated storage pit water. The liquid radioactive waste had been pumped to polyethylene vessels for intermediate storage before decontamination and release. The activity concentration of the storage pit water at the Aominstitute after a storage period of several years was about 40 kBq/l, the total amount of liquid in the storage pits was about 0.25 m 3 . It was attempted to find a simple and inexpensive method to remove especially the radioactive Cesium from the waste solution. Different methods for decontamination like distillation, precipitation and ion exchange are discussed

  16. 238Pu fuel form processes. Savannah River Laboratory monthly report

    International Nuclear Information System (INIS)

    1976-05-01

    Progress in the Savannah River 238 Pu fuel form program is summarized. Suspended solids observed in the technical-grade oxalic acid solution used in H-Area B-Line had no significant effect on particle size or morphology. A small but significant increase in product purity was noted with the use of reagent-grade oxalic acid. The density of hot-pressed LCHP pellets made from both problem and standardized feed decreased with longer milling times as was observed for multi-hundred watt (MHW) pellets. The LCHP pellets (greater than 90 percent theoretical density) generally cracked following final heat treatment. Cold-pressing studies indicate the anticipated pressure variation during cold pressing in the PuFF facility will have negligible effect on the density of MHW spheres. Construction of the plutonium experimental facility is 72 percent complete

  17. Process and catalysts for hydrocarbon conversion. [high antiknock motor fuel

    Energy Technology Data Exchange (ETDEWEB)

    1940-02-14

    High anti-knock motor fuel is produced from hydrocarbons by subjecting it at an elevated temperature to contact with a calcined mixture of hydrated silica, hydrated alumina, and hydrated zirconia, substantially free from alkali metal compounds. The catalyst may be prepared by precipitating silica gel by the acidification of an aqueous solution of an alkali metal silicate, intimately mixing hydrated alumina and hydrated zirconia therewith, drying, purifying the composite to substantially remove alkali metal compounds, again drying, forming the dried material into particles, and finally calcining. The resultant conversion products may be fractionated to produce gasoline, hydrocarbon oil above gasoling boiling point range, and a gaseous fraction of olefins which are polymerized into gasoline boiling range polymers.

  18. Simulation of primary fuel atomization processes at subcritical pressures.

    Energy Technology Data Exchange (ETDEWEB)

    Arienti, Marco

    2013-06-01

    This report documents results from an LDRD project for the first-principles simulation of the early stages of spray formation (primary atomization). The first part describes a Cartesian embedded-wall method for the calculation of flow internal to a real injector in a fully coupled primary calculation. The second part describes the extension to an all-velocity formulation by introducing a momentum-conservative semi-Lagrangian advection and by adding a compressible term in the Poissons equation. Accompanying the description of the new algorithms are verification tests for simple two-phase problems in the presence of a solid interface; a validation study for a scaled-up multi-hole Diesel injector; and demonstration calculations for the closing and opening transients of a single-hole injector and for the high-pressure injection of liquid fuel at supersonic velocity.

  19. Liquid entrainment through orifices by sparging gas

    International Nuclear Information System (INIS)

    Bonnet, J.M.; Malara, M.; Amblard, M.; Seiler, J.M.

    2001-01-01

    Corium Coolability by water flood during an MCCI (Molten Corium Concrete Interaction) is still an open problem. Several physical mechanisms have been identified which may reduce significantly and finally stop the ablation of concrete. Among these mechanisms, corium ejection by sparging gas into the overlying water may represent an important contribution. This mechanism was at the origin of a large and coolable debris bed and volcano formation in the MACE M3B test. This mechanism has also been observed in simulant material tests performed at UCSB and at FZK. The objective of the work, which is described in the present paper, is to model this mechanism and to quantify the liquid entrainment rate by sparging gas. (author)

  20. Research on plant of metal fuel fabrication using casting process (2)

    International Nuclear Information System (INIS)

    Senda, Yasuhide; Yamada, Seiya

    2005-02-01

    In this research work for the metal fuel fabrication system (38 tHM/y), the studies of the concept of the main process equipments were performed based on the previous studies on the process design and the quality control system design. In this study the handling equipment of the products were also designed, according to these designs the handling periods were evaluated. Consequently the numbers of the equipments were assessed taking into account for the method of the blending the fuel composition. (1) Structural concept design of the major equipments, the fuel handling machine and the gravimetries in the main fabrication process. The structural concept were designed for the fuel composition blending equipment, the fuel pin assembling equipment, the sodium bonding equipment, the handling equipment for fuel slug palettes, the handling equipment for fuel pins and the gravimetries. (2) Re-assessment of the numbers of the equipments taking account of the handling periods. Based on the results of item (1) the periods were evaluated for the fuel slug and pin handling. Processing time of demolder is short, then the number of it is increased to two. Three vehicles are also added to transfer the slugs and a heel smoothly. (3) Design of the buffer storages. The buffer storages among the equipments were designed through the comparison of the process speed between the equipments taking into account for the handling periods. The required amount of the structural parts (for example cladding materials) was assessed for the buffer in the same manner and the amount of the buffer facilities were optimized. (author)