WorldWideScience

Sample records for fuel reliability experience

  1. Report: New reliable method for the measurement of chlorine in refuse-derived fuels through combustion experiments in a pilot plant.

    Science.gov (United States)

    Schröer, Ramona; Urban, A I

    2010-02-01

    The calorific values and the chlorine contents of refuse-derived fuels were measured in the pilot combustion plant (PCP) by means of combustion experiments followed by mass and energy balancing. This plant reaches an increased precision by measuring the integrated values throughout the whole experimental period of three hours, based on a fuel capacity of 10 kg per test, allowing a more reliable measurement of pollutants than for experimental analysis of only a few grams of the sample. The combustion experiments are shown for the verification of the quality of the chlorine balancing in the PCP. The test evaluation was carried out by balancing the inputs and outputs of chlorine in the mass streams, and the recovery rates for chlorine were determined. An emission pattern for the chlorine is described by the transfer coefficients and via the temporal fluctuation of the hydrogen chloride concentration in the flue gas. The results of the combustion experiments prove that the balancing via combustion experiments in the PCP provides reliable data on the chlorine concentrations in the fuels, and is a new and reliable method for measuring polluting chlorine in refuse-derived fuels.

  2. Robust and reliable fuel cells; Robusta och tillfoerlitliga braensleceller

    Energy Technology Data Exchange (ETDEWEB)

    Nordlund, Joakim [Cellkraft AB, Stockholm (Sweden)

    2012-03-15

    For fuel cells to be a viable alternative for backup power in applications, where reliability is a critical factor, the reliability of fuel cells has to be high and documented. Based on intrinsic properties of fuel cells, it is safe to argue that it is possible to make them highly reliable, but to unleash the full reliability potential of fuel cells, some great engineering work has to be performed. Cellkraft has since many years been addressing this issue and this project is an important piece of this puzzle. The project included both a large number of laboratory testing of fuel cells and long experiments in field environment to verify the results from the laboratory work. The development work performed within this project is a solid base for the continuous work to fulfil Cellkraft's own, tough, technical reliability targets. The project targets below were achieved within this project: 1. The fuel cell start with 100 % reliability. 2. The fuel cell provides nominal power within 30 seconds in 100 % of the cases. 3. The fuel cell keeps providing nominal power as long as there is a demand in 100 % of the cases. 4. No cell in the fuel cell deviates from the mean cell potential with more than 0,1 V at full power.

  3. RELIABILITY AND DESIGN OF EXPERIMENTS

    Directory of Open Access Journals (Sweden)

    Adrian Stere PARIS

    2013-05-01

    Full Text Available The mechanical reliability uses many statistical tools to find the factors of influence and their levels inthe optimization of parameters on the basis of experimental data. Design of Experiments (DOE techniquesenables designers to determine simultaneously the individual and interactive effects of many factors that couldaffect the output results in any design. The state-of-the-art in the domain implies extended use of software and abasic mathematical knowledge, mainly applying ANOVA and the regression analysis of experimental data.

  4. The reliability and innovation of Mitsubishi PWR fuel

    Energy Technology Data Exchange (ETDEWEB)

    Abeta, S. [Mitsubishi Heavy Industries Ltd., Yokohama (Japan); Takahashi, T.; Doi, S. [Mitsubishi Heavy Industries Ltd., Kobe (Japan)

    1997-12-31

    Mitsubishi has been making continuous efforts to improve fuel reliability for many years. Although no significant issues have occurred recently, Mitsubishi has been continuing to develop further design modifications including a variety of corrective designs to eliminate debris fretting or grid fretting. Since fuel reliability has been improved to almost zero defect levels, the emphasis has changed to reducing the amount of spent fuel and improving economics by extending burnup to the next target of 55 GWd/t and to using fuel resources more effectively by MOX fuel utilization. (author).

  5. Spent Nuclear Fuel Transport Reliability Study

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jy-An John [ORNL; Wang, Hong [ORNL; Jiang, Hao [ORNL

    2016-01-01

    This conference paper was orignated and shorten from the following publisehd PTS documents: 1. Jy-An Wang, Hao Jiang, and Hong Wang, Dynamic Deformation Simulation of Spent Nuclear Fuel Assembly and CIRFT Deformation Sensor Stability Investigation, ORNL/SPR-2015/662, November 2015. 2. Jy-An Wang, Hong Wang, Mechanical Fatigue Testing of High-Burnup Fuel for Transportation Applications, NUREG/CR-7198, ORNL/TM-2014/214, May 2015. 3. Jy-An Wang, Hong Wang, Hao Jiang, Yong Yan, Bruce Bevard, Spent Nuclear Fuel Vibration Integrity Study 16332, WM2016 Conference, March 6 10, 2016, Phoenix, Arizona.

  6. Advanced Reactor Fuels Irradiation Experiment Design Objectives

    Energy Technology Data Exchange (ETDEWEB)

    Chichester, Heather Jean MacLean [Idaho National Lab. (INL), Idaho Falls, ID (United States); Hayes, Steven Lowe [Idaho National Lab. (INL), Idaho Falls, ID (United States); Dempsey, Douglas [Idaho National Lab. (INL), Idaho Falls, ID (United States); Harp, Jason Michael [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-09-01

    This report summarizes the objectives of the current irradiation testing activities being undertaken by the Advanced Fuels Campaign relative to supporting the development and demonstration of innovative design features for metallic fuels in order to realize reliable performance to ultra-high burnups. The AFC-3 and AFC-4 test series are nearing completion; the experiments in this test series that have been completed or are in progress are reviewed and the objectives and test matrices for the final experiments in these two series are defined. The objectives, testing strategy, and test parameters associated with a future AFC test series, AFC-5, are documented. Finally, the future intersections and/or synergies of the AFC irradiation testing program with those of the TREAT transient testing program, emerging needs of proposed Versatile Test Reactor concepts, and the Joint Fuel Cycle Study program’s Integrated Recycle Test are discussed.

  7. Alternative Aviation Fuel Experiment (AAFEX)

    Science.gov (United States)

    Anderson, B. E.; Beyersdorf, A. J.; Hudgins, C. H.; Plant, J. V.; Thornhill, K. L.; Winstead, E. L.; Ziemba, L. D.; Howard, R.; Corporan, E.; Miake-Lye, R. C.; Herndon, S. C.; Timko, M.; Woods, E.; Dodds, W.; Lee, B.; Santoni, G.; Whitefield, P.; Hagen, D.; Lobo, P.; Knighton, W. B.; Bulzan, D.; Tacina, K.; Wey, C.; VanderWal, R.; Bhargava, A.

    2011-01-01

    The rising cost of oil coupled with the need to reduce pollution and dependence on foreign suppliers has spurred great interest and activity in developing alternative aviation fuels. Although a variety of fuels have been produced that have similar properties to standard Jet A, detailed studies are required to ascertain the exact impacts of the fuels on engine operation and exhaust composition. In response to this need, NASA acquired and burned a variety of alternative aviation fuel mixtures in the Dryden Flight Research Center DC-8 to assess changes in the aircraft s CFM-56 engine performance and emission parameters relative to operation with standard JP-8. This Alternative Aviation Fuel Experiment, or AAFEX, was conducted at NASA Dryden s Aircraft Operations Facility (DAOF) in Palmdale, California, from January 19 to February 3, 2009 and specifically sought to establish fuel matrix effects on: 1) engine and exhaust gas temperatures and compressor speeds; 2) engine and auxiliary power unit (APU) gas phase and particle emissions and characteristics; and 3) volatile aerosol formation in aging exhaust plumes

  8. Aviation Fuel System Reliability and Fail-Safety Analysis. Promising Alternative Ways for Improving the Fuel System Reliability

    Directory of Open Access Journals (Sweden)

    I. S. Shumilov

    2017-01-01

    Full Text Available The paper deals with design requirements for an aviation fuel system (AFS, AFS basic design requirements, reliability, and design precautions to avoid AFS failure. Compares the reliability and fail-safety of AFS and aircraft hydraulic system (AHS, considers the promising alternative ways to raise reliability of fuel systems, as well as elaborates recommendations to improve reliability of the pipeline system components and pipeline systems, in general, based on the selection of design solutions.It is extremely advisable to design the AFS and AHS in accordance with Aviation Regulations АП25 and Accident Prevention Guidelines, ICAO (International Civil Aviation Association, which will reduce risk of emergency situations, and in some cases even avoid heavy disasters.ATS and AHS designs should be based on the uniform principles to ensure the highest reliability and safety. However, currently, this principle is not enough kept, and AFS looses in reliability and fail-safety as compared with AHS. When there are the examined failures (single and their combinations the guidelines to ensure the AFS efficiency should be the same as those of norm-adopted in the Regulations АП25 for AHS. This will significantly increase reliability and fail-safety of the fuel systems and aircraft flights, in general, despite a slight increase in AFS mass.The proposed improvements through the use of components redundancy of the fuel system will greatly raise reliability of the fuel system of a passenger aircraft, which will, without serious consequences for the flight, withstand up to 2 failures, its reliability and fail-safety design will be similar to those of the AHS, however, above improvement measures will lead to a slightly increasing total mass of the fuel system.It is advisable to set a second pump on the engine in parallel with the first one. It will run in case the first one fails for some reasons. The second pump, like the first pump, can be driven from the

  9. Fuel Cell Balance-of-Plant Reliability Testbed Project

    Energy Technology Data Exchange (ETDEWEB)

    Sproat, Vern [Stark State College of Technology, North Canton, OH (United States); LaHurd, Debbie [Lockheed Martin Corp., Oak Ridge, TN (United States)

    2016-10-29

    Reliability of the fuel cell system balance-of-plant (BoP) components is a critical factor that needs to be addressed prior to fuel cells becoming fully commercialized. Failure or performance degradation of BoP components has been identified as a life-limiting factor in fuel cell systems.1 The goal of this project is to develop a series of test beds that will test system components such as pumps, valves, sensors, fittings, etc., under operating conditions anticipated in real Polymer Electrolyte Membrane (PEM) fuel cell systems. Results will be made generally available to begin removing reliability as a roadblock to the growth of the PEM fuel cell industry. Stark State College students participating in the project, in conjunction with their coursework, have been exposed to technical knowledge and training in the handling and maintenance of hydrogen, fuel cells and system components as well as component failure modes and mechanisms. Three test beds were constructed. Testing was completed on gas flow pumps, tubing, and pressure and temperature sensors and valves.

  10. Software reliability experiments data analysis and investigation

    Science.gov (United States)

    Walker, J. Leslie; Caglayan, Alper K.

    1991-01-01

    The objectives are to investigate the fundamental reasons which cause independently developed software programs to fail dependently, and to examine fault tolerant software structures which maximize reliability gain in the presence of such dependent failure behavior. The authors used 20 redundant programs from a software reliability experiment to analyze the software errors causing coincident failures, to compare the reliability of N-version and recovery block structures composed of these programs, and to examine the impact of diversity on software reliability using subpopulations of these programs. The results indicate that both conceptually related and unrelated errors can cause coincident failures and that recovery block structures offer more reliability gain than N-version structures if acceptance checks that fail independently from the software components are available. The authors present a theory of general program checkers that have potential application for acceptance tests.

  11. Development of a Reliable Fuel Depletion Methodology for the HTR-10 Spent Fuel Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Kiwhan [Los Alamos National Laboratory; Beddingfield, David H. [Los Alamos National Laboratory; Geist, William H. [Los Alamos National Laboratory; Lee, Sang-Yoon [unaffiliated

    2012-07-03

    A technical working group formed in 2007 between NNSA and CAEA to develop a reliable fuel depletion method for HTR-10 based on MCNPX and to analyze the isotopic inventory and radiation source terms of the HTR-10 spent fuel. Conclusions of this presentation are: (1) Established a fuel depletion methodology and demonstrated its safeguards application; (2) Proliferation resistant at high discharge burnup ({approx}80 GWD/MtHM) - Unfavorable isotopics, high number of pebbles needed, harder to reprocess pebbles; (3) SF should remain under safeguards comparable to that of LWR; and (4) Diversion scenarios not considered, but can be performed.

  12. Wetted foam liquid fuel ICF target experiments

    Science.gov (United States)

    Olson, R. E.; Leeper, R. J.; Yi, S. A.; Kline, J. L.; Zylstra, A. B.; Peterson, R. R.; Shah, R.; Braun, T.; Biener, J.; Kozioziemski, B. J.; Sater, J. D.; Biener, M. M.; Hamza, A. V.; Nikroo, A.; Berzak Hopkins, L.; Ho, D.; LePape, S.; Meezan, N. B.

    2016-05-01

    We are developing a new NIF experimental platform that employs wetted foam liquid fuel layer ICF capsules. We will use the liquid fuel layer capsules in a NIF sub-scale experimental campaign to explore the relationship between hot spot convergence ratio (CR) and the predictability of hot spot formation. DT liquid layer ICF capsules allow for flexibility in hot spot CR via the adjustment of the initial cryogenic capsule temperature and, hence, DT vapor density. Our hypothesis is that the predictive capability of hot spot formation is robust and 1D-like for a relatively low CR hot spot (CR∼15), but will become less reliable as hot spot CR is increased to CR>20. Simulations indicate that backing off on hot spot CR is an excellent way to reduce capsule instability growth and to improve robustness to low-mode x-ray flux asymmetries. In the initial experiments, we will test our hypothesis by measuring hot spot size, neutron yield, ion temperature, and burn width to infer hot spot pressure and compare to predictions for implosions with hot spot CR's in the range of 12 to 25. Larger scale experiments are also being designed, and we will advance from sub-scale to full-scale NIF experiments to determine if 1D-like behavior at low CR is retained as the scale-size is increased. The long-term objective is to develop a liquid fuel layer ICF capsule platform with robust thermonuclear burn, modest CR, and significant α-heating with burn propagation.

  13. Analysis of recent fuel-disruption experiments

    Energy Technology Data Exchange (ETDEWEB)

    Kramer, J.M.; Kraft, T.E.; DiMelfi, R.J.; Fenske, G.R.; Gruber, E.E.

    1982-01-01

    Recent USDOE-sponsored DEH, FGR, and TREAT F series fuel-disruption experiments are analyzed with existing analytical models. The experiments are interpreted and the results used to evaluate the models. Calculations are presented using the FRAS3 fission-gas-behavior code and the DiMelfi-Deitrich fuel-response model.

  14. Analysis of recent fuel-disruption experiments

    Energy Technology Data Exchange (ETDEWEB)

    Kramer, J.M.; Kraft, T.E.; DiMelfi, R.J.; Fenske, G.R.; Gruber, E.E.

    1982-01-01

    Recent USDOE-sponsored DEH, FGR, and TREAT F series fuel-disruption experiments are analyzed with existing analytical models. The experiments are interpreted and the results used to evaluate the models. Calculations are presented using the FRAS3 fission-gas-behavior code and the DiMelfi-Deitrich fuel-response model.

  15. Critical experiments with mixed oxide fuel

    Energy Technology Data Exchange (ETDEWEB)

    Harris, D.R. [Rensselaer Polytechnic Institute, Troy, NY (United States)

    1997-06-01

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

  16. Applying fuel cell experience to sustainable power products

    Science.gov (United States)

    King, Joseph M.; O'Day, Michael J.

    Fuel cell power plants have demonstrated high efficiency, environmental friendliness, excellent transient response, and superior reliability and durability in spacecraft and stationary applications. Broader application of fuel cell technology promises significant contribution to sustainable global economic growth, but requires improvement to size, cost, fuel flexibility and operating flexibility. International Fuel Cells (IFC) is applying lessons learned from delivery of more than 425 fuel cell power plants and 3 million h of operation to the development of product technology which captures that promise. Key findings at the fuel cell power plant level include: (1) ancillary components account for more than 40% of the weight and nearly all unscheduled outages of hydrocarbon-fuelled power plants; a higher level of integration and simplification is required to achieve reasonable characteristics, (2) hydrocarbon fuel cell power plant components are highly interactive; the fuel processing approach and power plant operating pressure are major determinants of overall efficiency, and (3) achieving the durability required for heavy duty vehicles and stationary applications requires simultaneous satisfaction of electrochemical, materials and mechanical considerations in the design of the cell stack and other power plant components. Practical designs must minimize application specific equipment. Related lessons for stationary fuel cell power plants include: (1) within fuel specification limits, natural gas varies widely in heating value, minor constituents such as oxygen and nitrogen content and trace compounds such as the odorant; (2) city water quality varies widely; recovery of product water for process use avoids costly, complicated and site-specific water treatment systems, but water treatment is required to eliminate impurities and (3) the embedded protection functions for reliable operation of fuel cell power conditioners meet or exceed those required for connection to

  17. Water-moderated reactor fuel cladding reliability study

    OpenAIRE

    Бакутяк, Елена Викторовна; Пелых, Сергей Николаевич

    2014-01-01

    Considering the fuel element, averaged by fuel assembly (FA) of water-moderated reactor with the power of 1000 MW (VVER-1000), the number of fuel elements with the greatest cladding failure probability after 4 operation years at Khmelnitsky NPP-2 (KNPP-2) is found. This will allow to calculate the fuel cladding failure probability and determine the most likely cladding damages, which will enable to improve the performance and economic indexes of VVER.The novelty of the paper lies in calculati...

  18. Bulk Fuel Pricing: DOD Needs to Take Additional Actions to Establish a More Reliable Methodology

    Science.gov (United States)

    2015-11-19

    Defense Bulk Fuel Pricing: DOD Needs to Take Additional Actions to Establish a More Reliable Methodology Dear Secretary Carter: Each fiscal...that the Department of Defense (DOD) will charge for fuel, which the military services and other fuel customers use in developing their annual budget...official with the Office of the Under Secretary of Defense (Comptroller) who oversees DOD’s bulk fuel program told us that the department expects to

  19. Reliability in sealing of canister for spent nuclear fuel

    Energy Technology Data Exchange (ETDEWEB)

    Ronneteg, Ulf [Bodycote Materials Testing AB, Nykoeping (Sweden); Cederqvist, Lars; Ryden, Haakan [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden); Oeberg, Tomas [Tomas Oeberg Konsult AB, Karlskrona (Sweden); Mueller, Christina [Federal Inst. for Materials Research and Testing, Berlin (Germany)

    2006-06-15

    The reliability of the system for sealing the canister and inspecting the weld that has been developed for the Encapsulation plant was investigated. In the investigation the occurrence of discontinuities that can be formed in the welds was determined both qualitatively and quantitatively. The probability that these discontinuities can be detected by nondestructive testing (NDT) was also studied. The friction stir welding (FSW) process was verified in several steps. The variables in the welding process that determine weld quality were identified during the development work. In order to establish the limits within which they can be allowed to vary, a screening experiment was performed where the different process settings were tested according to a given design. In the next step the optimal process setting was determined by means of a response surface experiment, whereby the sensitivity of the process to different variable changes was studied. Based on the optimal process setting, the process window was defined, i.e. the limits within which the welding variables must lie in order for the process to produce the desired result. Finally, the process was evaluated during a demonstration series of 20 sealing welds which were carried out under production-like conditions. Conditions for the formation of discontinuities in welding were investigated. The investigations show that the occurrence of discontinuities is dependent on the welding variables. Discontinuities that can arise were classified and described with respect to characteristics, occurrence, cause and preventive measures. To ensure that testing of the welds has been done with sufficient reliability, the probability of detection (POD) of discontinuities by NDT and the accuracy of size determination by NDT were determined. In the evaluation of the demonstration series, which comprised 20 welds, a statistical method based on the generalized extreme value distribution was fitted to the size estimate of the indications

  20. Fueling studies on the lithium tokamak experiment

    Science.gov (United States)

    Lundberg, Daniel Patrick

    Lithium plasma facing components reduce the flux of "recycled" particles entering the plasma edge from the plasma facing components. This results in increased external fueling requirements and provides the opportunity to control the magnitude and distribution of the incoming particle flux. It has been predicted that the plasma density profile will then be determined by the deposition profile of the external fueling, rather than dominated by the recycled particle flux. A series of experiments on the Lithium Tokamak Experiment demonstrate that lithium wall coatings facilitate control of the neutral and plasma particle inventories. With fresh lithium coatings and careful gas injection programming, over 90% of the injected particle inventory can be absorbed in the lithium wall during a discharge. Furthermore, dramatic changes in the fueling requirements and plasma parameters were observed when lithium coatings were applied. This is largely due to the elimination of water as an impurity on the plasma facing components. A Molecular Cluster Injector (MCI) was developed for the fueling of LTX plasmas. The MCI uses a supersonic nozzle, cooled to liquid nitrogen temperatures, to create the conditions necessary for molecular cluster formation. It has been predicted that molecular clusters will penetrate deeper into plasmas than gas-phase molecules via a reduced ionization cross-section and by improving the collimation of the neutral jet. Using an electron beam diagnostic, the densities of the cryogenic MCI are measured to be an order of magnitude higher than in the room-temperature jets formed with the same valve pressure. This indicates increased collimation relative to what would be expected from ideal gas dynamics alone. A systematic study of the fueling efficiencies achieved with the LTX fueling systems is presented. The fueling efficiency of the Supersonic Gas Injector (SGI) is demonstrated to be strongly dependent on the distance between the nozzle and plasma edge. The

  1. System-level Reliability Assessment of Power Stage in Fuel Cell Application

    DEFF Research Database (Denmark)

    Zhou, Dao; Wang, Huai; Blaabjerg, Frede

    2016-01-01

    High efficient and less pollutant fuel cell stacks are emerging and strong candidates of the power solution used for mobile base stations. In the application of the backup power, the availability and reliability hold the highest priority. This paper considers the reliability metrics from...... the component-level to the system-level for the power stage used in a fuel cell application. It starts with an estimation of the annual accumulated damage for the key power electronic components according to the real mission profile of the fuel cell system. Then, considering the parameter variations in both...... reliability. In a case study of a 5 kW fuel cell power stage, the parameter variations of the lifetime model prove that the exponential factor of the junction temperature fluctuation is the most sensitive parameter. Besides, if a 5-out-of-6 redundancy is used, it is concluded both the B10 and the B1 system...

  2. New results from the NSRR experiments with high burnup fuel

    Energy Technology Data Exchange (ETDEWEB)

    Fuketa, Toyoshi; Ishijima, Kiyomi; Mori, Yukihide [Japan Atomic Research Institute, Toaki, Ibaraki (Japan)] [and others

    1996-03-01

    Results obtained in the NSRR power burst experiments with irradiated PWR fuel rods with fuel burnup up to 50 MWd/kgU are described and discussed in this paper. Data concerning test method, test fuel rod, pulse irradiation, transient records during the pulse and post irradiation examination are described, and interpretations and discussions on fission gas release and fuel pellet fragmentation are presented. During the pulse-irradiation experiment with 50 MWd/kgU PWR fuel rod, the fuel rod failed at considerably low energy deposition level, and large amount of fission gas release and fragmentation of fuel pellets were observed.

  3. Experience with unconventional gas turbine fuels

    Energy Technology Data Exchange (ETDEWEB)

    Mukherjee, D.K. [ABB Power Generation Ltd., Baden (Switzerland)

    1996-12-31

    Low grade fuels such as Blast Furnace Gas, biomass, residual oil, coke, and coal - if used in conjunction with appropriate combustion, gasification, and clean-up processes and in combination with a gas turbine combined cycle -offer attractive and environmentally sound power generation. Recently, the Bao Shan Iron and Steel Company in Shanghai placed an order with Kawasaki Heavy Industries, Japan, to supply a combined-cycle power plant. The plant is to employ ABB`s GT 11N2 with a combustor modified to burn blast furnace gas. Recent tests in Shanghai and at Kawasaki Steel, Japan, have confirmed the burner design. The same basic combustor concept can also be used for the low BTU gas derived from airblown gasification processes. ABB is also participating in the API project: A refinery-residual gasification combined-cycle plant in Italy. The GT 13E2 gas turbine employees MBTU EV burners that have been successfully tested under full operating conditions. These burners can also handle the MBTU gas produced in oxygenblown coal gasification processes. ABB`s vast experience in burning blast furnace gas (21 plants built during the 1950s and 1960s), residuals, crude, and coal in various gas turbine applications is an important asset for building such power plants. This presentation discusses some of the experience gained in such plants. (orig.) 6 refs.

  4. Reliability prediction of large fuel cell stack based on structure stress analysis

    Science.gov (United States)

    Liu, L. F.; Liu, B.; Wu, C. W.

    2017-09-01

    The aim of this paper is to improve the reliability of Proton Electrolyte Membrane Fuel Cell (PEMFC) stack by designing the clamping force and the thickness difference between the membrane electrode assembly (MEA) and the gasket. The stack reliability is directly determined by the component reliability, which is affected by the material property and contact stress. The component contact stress is a random variable because it is usually affected by many uncertain factors in the production and clamping process. We have investigated the influences of parameter variation coefficient on the probability distribution of contact stress using the equivalent stiffness model and the first-order second moment method. The optimal contact stress to make the component stay in the highest level reliability is obtained by the stress-strength interference model. To obtain the optimal contact stress between the contact components, the optimal thickness of the component and the stack clamping force are optimally designed. Finally, a detailed description is given how to design the MEA and gasket dimensions to obtain the highest stack reliability. This work can provide a valuable guidance in the design of stack structure for a high reliability of fuel cell stack.

  5. MEMS Reliability: Infrastructure, Test Structures, Experiments, and Failure Modes

    Energy Technology Data Exchange (ETDEWEB)

    TANNER,DANELLE M.; SMITH,NORMAN F.; IRWIN,LLOYD W.; EATON,WILLIAM P.; HELGESEN,KAREN SUE; CLEMENT,J. JOSEPH; MILLER,WILLIAM M.; MILLER,SAMUEL L.; DUGGER,MICHAEL T.; WALRAVEN,JEREMY A.; PETERSON,KENNETH A.

    2000-01-01

    The burgeoning new technology of Micro-Electro-Mechanical Systems (MEMS) shows great promise in the weapons arena. We can now conceive of micro-gyros, micro-surety systems, and micro-navigators that are extremely small and inexpensive. Do we want to use this new technology in critical applications such as nuclear weapons? This question drove us to understand the reliability and failure mechanisms of silicon surface-micromachined MEMS. Development of a testing infrastructure was a crucial step to perform reliability experiments on MEMS devices and will be reported here. In addition, reliability test structures have been designed and characterized. Many experiments were performed to investigate failure modes and specifically those in different environments (humidity, temperature, shock, vibration, and storage). A predictive reliability model for wear of rubbing surfaces in microengines was developed. The root causes of failure for operating and non-operating MEMS are discussed. The major failure mechanism for operating MEMS was wear of the polysilicon rubbing surfaces. Reliability design rules for future MEMS devices are established.

  6. Neutronic experiment planning for the Fuels Refabrication and Development Program

    Energy Technology Data Exchange (ETDEWEB)

    Gore, B.F.; NcNeese, J.P.; Zimmerman, M.G.; Konzek, G.J.

    1979-12-01

    A program of experiments using /sup 233/UO/sub 2/ - ThO/sub 2/ fuel was proposed to provide new and improved neutronic and criticality data for thorium based nuclear fuels, in order to support the licensing of /sup 233/UO/sub 2/ - ThO/sub 2/ fuels in LWR cores. This would support the goal to develop technology for proliferation resistant fuel cycles to a point where fuel cycle choice is not limited by refabrication technology. The proposed experimental program is described in this document, along with initial planning and fuel acquisition activities undertaken during FY 1979. The program was terminated following notification that the DOE-sponsored denatured LWR Fuel Program which the experiments supported was to be discontinued.

  7. Reliability considerations of a fuel cell backup power system for telecom applications

    Science.gov (United States)

    Serincan, Mustafa Fazil

    2016-03-01

    A commercial fuel cell backup power unit is tested in real life operating conditions at a base station of a Turkish telecom operator. The fuel cell system responds to 256 of 260 electric power outages successfully, providing the required power to the base station. Reliability of the fuel cell backup power unit is found to be 98.5% at the system level. On the other hand, a qualitative reliability analysis at the component level is carried out. Implications of the power management algorithm on reliability is discussed. Moreover, integration of the backup power unit to the base station ecosystem is reviewed in the context of reliability. Impact of inverter design on the stability of the output power is outlined. Significant current harmonics are encountered when a generic inverter is used. However, ripples are attenuated significantly when a custom design inverter is used. Further, fault conditions are considered for real world case studies such as running out of hydrogen, a malfunction in the system, or an unprecedented operating scheme. Some design guidelines are suggested for hybridization of the backup power unit for an uninterrupted operation.

  8. OPTIMUM DESIGN OF EXPERIMENTS FOR ACCELERATED RELIABILITY TESTING

    Directory of Open Access Journals (Sweden)

    Sebastian Marian ZAHARIA

    2014-05-01

    Full Text Available In this paper is presented a case study that demonstrates how design to experiments (DOE information can be used to design better accelerated reliability tests. In the case study described in this paper, will be done a comparison and optimization between main accelerated reliability test plans (3 Level Best Standard Plan, 3 Level Best Compromise Plan, 3 Level Best Equal Expected Number Failing Plan, 3 Level 4:2:1 Allocation Plan. Before starting an accelerated reliability test, it is advisable to have a plan that helps in accurately estimating reliability at operating conditions while minimizing test time and costs. A test plan should be used to decide on the appropriate stress levels that should be used (for each stress type and the amount of the test units that need to be allocated to the different stress levels (for each combination of the different stress types' levels. For the case study it used ALTA 7 software what provides a complete analysis for data from accelerated reliability tests

  9. Proof test on thermal and hydraulic design reliability of Japanese PWR fuel assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Akiyama, Mamoru (Univ. of Tokyo (Japan)); Inoue, Akira (Tokyo Institute of Technology (Japan)); Miyazaki, Keiji (Osaka Univ. (Japan)); Abeta, Sadaaki (Mitsubishi, Tokyo (Japan)); Hori, Keiichi (Mitsubishi, Hyogo (Japan)); Mukasa, Tomio; Oishi, Masao; Aoki, Toshimasa; Makihara, Yoshiaki

    1990-01-01

    A series of departure from nucleate boiling (DNB) tests for pressurized water reactors (PWRs) was performed at the Nuclear Power Engineering Test Center. The objective was to prove the reliability of fuel assembly design by confirming the thermal margin of heat transfer. The present method for evaluating the DNB ratio in a Japanese 17 x 17 PWR core is adequate according to the newly obtained DNB test data.

  10. A new topology of fuel cell hybrid power source for efficient operation and high reliability

    Science.gov (United States)

    Bizon, Nicu

    2011-03-01

    This paper analyzes a new fuel cell Hybrid Power Source (HPS) topology having the feature to mitigate the current ripple of the fuel cell inverter system. In the operation of the inverter system that is grid connected or supplies AC motors in vehicle application, the current ripple normally appears at the DC port of the fuel cell HPS. Consequently, if mitigation measures are not applied, this ripple is back propagated to the fuel cell stack. Other features of the proposed fuel cell HPS are the Maximum Power Point (MPP) tracking, high reliability in operation under sharp power pulses and improved energy efficiency in high power applications. This topology uses an inverter system directly powered from the appropriate fuel cell stack and a controlled buck current source as low power source used for ripple mitigation. The low frequency ripple mitigation is based on active control. The anti-ripple current is injected in HPS output node and this has the LF power spectrum almost the same with the inverter ripple. Consequently, the fuel cell current ripple is mitigated by the designed active control. The ripple mitigation performances are evaluated by indicators that are defined to measure the mitigation ratio of the low frequency harmonics. In this paper it is shown that good performances are obtained by using the hysteretic current control, but better if a dedicated nonlinear controller is used. Two ways to design the nonlinear control law are proposed. First is based on simulation trials that help to draw the characteristic of ripple mitigation ratio vs. fuel cell current ripple. The second is based on Fuzzy Logic Controller (FLC). The ripple factor is up to 1% in both cases.

  11. Assessment of reactivity transient experiments with high burnup fuel

    Energy Technology Data Exchange (ETDEWEB)

    Ozer, O.; Yang, R.L.; Rashid, Y.R.; Montgomery, R.O.

    1996-03-01

    A few recent experiments aimed at determining the response of high-burnup LWR fuel during a reactivity initiated accident (RIA) have raised concerns that existing failure criteria may be inappropriate for such fuel. In particular, three experiments (SPERT CDC-859, NSRR HBO-1 and CABRI REP Na-1) appear to have resulted in fuel failures at only a fraction of the anticipated enthalpy levels. In evaluating the results of such RIA simulation experiments, however, it is necessary that the following two key considerations be taken into account: (1) Are the experiments representative of conditions that LWR fuel would experience during an in-reactor RIA event? (2) Is the fuel that is being utilized in the tests representative of the present (or anticipated) population of LWR fuel? Conducting experiments under conditions that can not occur in-reactor can trigger response modes that could not take place during in-reactor operation. Similarly, using unrepresentative fuel samples for the tests will produce failure information that is of limited relevance to commercial LWR fuel. This is particularly important for high-burnup fuel since the manner under which the test samples are base-irradiated prior to the test will impact the mechanical properties of the cladding and will therefore affect the RIA response. A good example of this effect can be seen in the results of the SPERT CDC-859 test and in the NSRR JM-4 and JM-5 tests. The conditions under which the fuel used for these tests was fabricated and/or base-irradiated prior to the RIA pulse resulted in the formation of multiple cladding defects in the form of hydride blisters. When this fuel was subjected to the RIA power pulse, it failed by developing multiple cracks that were closely correlated with the locations of the pre-existing hydride blisters. In the case of the JM tests, many of the cracks formed within the blisters themselves and did not propagate beyond the heavily hydrided regions.

  12. A Mechanistic Reliability Assessment of RVACS and Metal Fuel Inherent Reactivity Feedbacks

    Energy Technology Data Exchange (ETDEWEB)

    Grabaskas, David; Brunett, Acacia J.; Passerini, Stefano; Grelle, Austin

    2017-09-24

    GE Hitachi Nuclear Energy (GEH) and Argonne National Laboratory (Argonne) participated in a two year collaboration to modernize and update the probabilistic risk assessment (PRA) for the PRISM sodium fast reactor. At a high level, the primary outcome of the project was the development of a next-generation PRA that is intended to enable risk-informed prioritization of safety- and reliability-focused research and development. A central Argonne task during this project was a reliability assessment of passive safety systems, which included the Reactor Vessel Auxiliary Cooling System (RVACS) and the inherent reactivity feedbacks of the metal fuel core. Both systems were examined utilizing a methodology derived from the Reliability Method for Passive Safety Functions (RMPS), with an emphasis on developing success criteria based on mechanistic system modeling while also maintaining consistency with the Fuel Damage Categories (FDCs) of the mechanistic source term assessment. This paper provides an overview of the reliability analyses of both systems, including highlights of the FMEAs, the construction of best-estimate models, uncertain parameter screening and propagation, and the quantification of system failure probability. In particular, special focus is given to the methodologies to perform the analysis of uncertainty propagation and the determination of the likelihood of violating FDC limits. Additionally, important lessons learned are also reviewed, such as optimal sampling methodologies for the discovery of low likelihood failure events and strategies for the combined treatment of aleatory and epistemic uncertainties.

  13. Lunar Regenerative Fuel Cell (RFC) Reliability Testing for Assured Mission Success

    Science.gov (United States)

    Bents, David J.

    2009-01-01

    NASA's Constellation program has selected the closed cycle hydrogen oxygen Polymer Electrolyte Membrane (PEM) Regenerative Fuel Cell (RFC) as its baseline solar energy storage system for the lunar outpost and manned rover vehicles. Since the outpost and manned rovers are "human-rated," these energy storage systems will have to be of proven reliability exceeding 99 percent over the length of the mission. Because of the low (TRL=5) development state of the closed cycle hydrogen oxygen PEM RFC at present, and because there is no equivalent technology base in the commercial sector from which to draw or infer reliability information from, NASA will have to spend significant resources developing this technology from TRL 5 to TRL 9, and will have to embark upon an ambitious reliability development program to make this technology ready for a manned mission. Because NASA would be the first user of this new technology, NASA will likely have to bear all the costs associated with its development.When well-known reliability estimation techniques are applied to the hydrogen oxygen RFC to determine the amount of testing that will be required to assure RFC unit reliability over life of the mission, the analysis indicates the reliability testing phase by itself will take at least 2 yr, and could take up to 6 yr depending on the number of QA units that are built and tested and the individual unit reliability that is desired. The cost and schedule impacts of reliability development need to be considered in NASA's Exploration Technology Development Program (ETDP) plans, since life cycle testing to build meaningful reliability data is the only way to assure "return to the moon, this time to stay, then on to Mars" mission success.

  14. On-site fuel inspection experience and developments in Spain

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez, A.; Alvarez, P. [ENUSA Industrias Avanzadas SA, Fuel Services, C. Salamanca-Vitigudino km 0, 70, 37008 Salamanca (Spain); Fernandez, J.R.; Mendez, M. [TECNATOM SA, Steam Generators and Nuclear Fuel, Av. Montes de Oca no. 1, 28703 San Sebastian de los Reyes, Madrid (Spain)

    2010-07-01

    Fuel performance characterization is essential to assure that new fuel designs and plant changes do not lead to unexpected fuel behaviour. Additionally, measurement of fuel key features is basic for the development of accurate design models needed for licensing purposes when a new fuel design is being proposed. Due to the fact that pool-side inspections are more economical and less time consuming than post irradiation examinations conducted in hot cell facilities it has been necessary to develop reliable equipments able to measure with a sufficient accuracy the main characteristics of irradiated fuel behaviour. Since 1994 ENUSA Industrias Avanzadas SA and TECNATOM are working together to develop the capacities for fuel inspection within the SICOM (Spanish acronym for Fuel Inspection System) family of equipments. Non-Destructive methods (NDE) such as eddy current for oxide thickness determination and defects characterization, and LVDT (Linear Variable Differential Transformer) for dimensional analysis are the main techniques used in the equipments, supported with visual inspections, although new techniques for additional characteristics evaluation are currently being introduced. (authors)

  15. Dual-Fuel Truck Fleet: Start-Up Experience

    Energy Technology Data Exchange (ETDEWEB)

    NREL

    1998-09-30

    Although dual-fuel engine technology has been in development and limited use for several years, it has only recently moved toward full-scale operational capability for heavy-duty truck applications. Unlike a bifuel engine, which has two separate fuel systems that are used one at a time, a dual-fuel engine uses two fuel systems simultaneously. One of California's South Coast Air Quality Management District (SCAQMD) current programs is a demonstration of dual-fuel engine technology in heavy-duty trucks. These trucks are being studied as part of the National Renewable Energy Laboratory's (NREL's) Alternative Fuel Truck Program. This report describes the start-up experience from the program.

  16. Gaseous fuels: past experiences and future expectations

    NARCIS (Netherlands)

    Steen, M. van der

    1996-01-01

    During the fifties, the use of LPG (Liquefied Petroleum Gas) was promoted in Italy and the Netherlands. The Dutch government promulgated tax regulations which made the use of LPG, available in large quentities as a by-product in the refineries, attractive as an automotive fuel. Dedicated heavy-duty

  17. JSC Case Study: Fleet Experience with E-85 Fuel

    Science.gov (United States)

    Hummel, Kirck

    2009-01-01

    JSC has used E-85 as part of an overall strategy to comply with Presidential Executive Order 13423 and the Energy Policy Act. As a Federal fleet, we are required to reduce our petroleum consumption by 2 percent per year, and increase the use of alternative fuels in our vehicles. With the opening of our onsite dispenser in October 2004, JSC became the second federal fleet in Texas and the fifth NASA center to add E-85 fueling capability. JSC has a relatively small number of GSA Flex Fuel fleet vehicles at the present time (we don't include personal vehicles, or other contractor's non-GSA fleet), and there were no reasonably available retail E-85 fuel stations within a 15-minute drive or within five miles (one way). So we decided to install a small 1000 gallon onsite tank and dispenser. It was difficult to obtain a supplier due to our low monthly fuel consumption, and our fuel supplier contract has changed three times in less than five years. We experiences a couple of fuel contamination and quality control issues. JSC obtained good information on E-85 from the National Ethanol Vehicle Coalition (NEVC). We also spoke with Defense Energy Support Center, (DESC), Lawrence Berkeley Laboratory, and US Army Fort Leonard Wood. E-85 is a liquid fuel that is dispensed into our Flexible Fuel Vehicles identically to regular gasoline, so it was easy for our vehicle drivers to make the transition.

  18. Reliability Assessment of Fuel Cell System - A Framework for Quantitative Approach

    DEFF Research Database (Denmark)

    Lee, Shinae; Zhou, Dao; Wang, Huai

    2016-01-01

    Hydrogen Fuel Cell (FC) technologies have been developed to overcome the operational and environmental challenges associated with using conventional power sources. Telecommunication industry, in particular, has implemented FC systems for the backup power function. The designers and manufacturers...... of such FC systems have great interest in verifying the performance and safety of their systems. Reliability assessment is designated to support decision-making about the optimal design and the operation strategies for FC systems to be commercial viable. This involves the properties of the system...... such as component failures, the system architecture, and operational strategies. This paper suggests an approach that includes Failure Modes and Effects Analysis (FMEA), Fault Tree Analysis (FTA), and Reliability Block Diagram (RBD). For a case study, and the service lifetime of a commercial 5 kW Proton Exchange...

  19. Reliability and availability analysis of low power portable direct methanol fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Sisworahardjo, N.S. [School of Electrical Engineering and Informatics, Bandung Institute of Technology, Bandung, 40132 (Indonesia); Department of Electrical and Computer Engineering, University of South Alabama, Mobile, AL 36688 (United States); Alam, M.S.; Aydinli, G. [Department of Electrical and Computer Engineering, University of South Alabama, Mobile, AL 36688 (United States)

    2008-03-01

    This paper presents a methodology for modeling and calculating the reliability and availability of low power portable direct methanol fuel cells (DMFCs). System reliability and availability are critical factors for improving market acceptance and for determining the competitiveness of the low power DMFC. Two techniques have been used for analyzing the system reliability and availability requirements for various system components. Reliability block diagram (RBD) is formed based on the failure rates of irreparable system components. A state-space method is developed to calculate system availability using the Markov model (MM). The state-space method incorporates three different states - operational, derated, and fully faulted states. Since most system components spend their lifetime in performing normal functional task, this research is focused mainly on this operational period. The failure and repair rates for repairable DMFC systems are estimated on the basis of a homogeneous Poisson process (HPP) and exponential distribution. Extensive analytical modeling and simulation study has been performed to verify the effectiveness of the proposed technique. (author)

  20. Reliability and availability analysis of low power portable direct methanol fuel cells

    Science.gov (United States)

    Sisworahardjo, N. S.; Alam, M. S.; Aydinli, G.

    This paper presents a methodology for modeling and calculating the reliability and availability of low power portable direct methanol fuel cells (DMFCs). System reliability and availability are critical factors for improving market acceptance and for determining the competitiveness of the low power DMFC. Two techniques have been used for analyzing the system reliability and availability requirements for various system components. Reliability block diagram (RBD) is formed based on the failure rates of irreparable system components. A state-space method is developed to calculate system availability using the Markov model (MM). The state-space method incorporates three different states-operational, derated, and fully faulted states. Since most system components spend their lifetime in performing normal functional task, this research is focused mainly on this operational period. The failure and repair rates for repairable DMFC systems are estimated on the basis of a homogeneous Poisson process (HPP) and exponential distribution. Extensive analytical modeling and simulation study has been performed to verify the effectiveness of the proposed technique.

  1. Experiments on contrail formation from fuels with different sulfur content

    Energy Technology Data Exchange (ETDEWEB)

    Busen, R.; Kuhn, M.; Petzold, A.; Schroeder, F.; Schumann, U. [Deutsche Forschungs- und Versuchsanstalt fuer Luft- und Raumfahrt e.V., Oberpfaffenhofen (Germany); Baumgardner, D. [National Center for Atmospheric Research, Boulder, CO (United States); Borrmann, S. [Mainz Univ. (Germany); Hagen, D.; Whitefield, Ph. [Missouri Univ., Rolla, MO (United States). Bureau of Mines; Stroem, J. [Stockholm Univ. (Sweden)

    1997-12-31

    A series of both flight tests and ground experiments has been performed to evaluate the role of the sulfur contained in kerosene in condensation trail (contrail) formation processes. The results of the first experiments are compiled briefly. The last SULFUR 4 experiment dealing with the influence of the fuel sulfur content and different appertaining conditions is described in detail. Different sulfur mass fractions lead to different particle size spectra. The number of ice particles in the contrail increases by about a factor of 2 for 3000 ppm instead of 6 ppm sulfur fuel content. (author) 10 refs.

  2. Irradiation Experiment Conceptual Design Parameters for NBSR Fuel Conversion

    Energy Technology Data Exchange (ETDEWEB)

    Brown, N. R. [Brookhaven National Lab. (BNL), Upton, NY (United States). Nuclear Science and Technology Dept.; Brown, N. R. [Brookhaven National Lab. (BNL), Upton, NY (United States). Nuclear Science and Technology Dept.; Baek, J. S [Brookhaven National Lab. (BNL), Upton, NY (United States). Nuclear Science and Technology Dept.; Hanson, A. L. [Brookhaven National Lab. (BNL), Upton, NY (United States). Nuclear Science and Technology Dept.; Cuadra, A. [Brookhaven National Lab. (BNL), Upton, NY (United States). Nuclear Science and Technology Dept.; Cheng, L. Y. [Brookhaven National Lab. (BNL), Upton, NY (United States). Nuclear Science and Technology Dept.; Diamond, D. J. [Brookhaven National Lab. (BNL), Upton, NY (United States). Nuclear Science and Technology Dept.

    2014-04-30

    It has been proposed to convert the National Institute of Standards and Technology (NIST) research reactor, known as the NBSR, from high-enriched uranium (HEU) fuel to low-Enriched uranium (LEU) fuel. The motivation to convert the NBSR to LEU fuel is to reduce the risk of proliferation of special nuclear material. This report is a compilation of relevant information from recent studies related to the proposed conversion using a metal alloy of LEU with 10 w/o molybdenum. The objective is to inform the design of the mini-plate and full-size-Plate irradiation experiments that are being planned. This report provides relevant dimensions of the fuel elements, and the following parameters at steady state: average and maximum fission rate density and fission density, fuel temperature distribution for the plate with maximum local temperature, and two-dimensional heat flux profiles of fuel plates with high power densities. The latter profiles are given for plates in both the inner and outer core zones and for cores with both fresh and depleted shim arms (reactivity control devices). A summary of the methodology to obtain these results is presented. Fuel element tolerance assumptions and hot channel factors used in the safety analysis are also given.

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

    Science.gov (United States)

    Marcum, W. R.; Wachs, D. M.; Robinson, A. B.; Lillo, M. A.

    2016-04-01

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

  4. The reliability of untempered end plug welds on HT9-clad IFR fuel elements

    Energy Technology Data Exchange (ETDEWEB)

    Crawford, D C; Porter, D L

    1987-02-01

    Welding generally leaves residual stresses in transformed weld zones, which can initiate cracks from flaws already present in the weld zones. When HT9 cools from welding temperatures, a martensite phase forms in the weld fusion zone and heat-affected zone. Because this martensite phase is hard and brittle, it is particularly susceptible to cracking aggravated by residual stresses. This causes concern over the use of untempered welds on HT9-clad fuel elements. To determine if residual stresses present in end-plug weld zones would affect fuel pin performance, HT9 capsules with prototypic TIG- and CD-welded end plugs (in the tempered and as-welded conditions) were pressurized to failure at room temperature, 550{sup 0}C, and 600{sup 0}C. None of the capsules failed in a weld zone. To determine the effects of reactor operating temperatures on untempered welds, prototypic TIG welds were tempered at reactor bulk sodium temperature and an expected sodium outlet temperature for various lengths of time. Subsequent tensile and burst tests of these specimens proved that any embrittling effects that may have been induced in these welds were of no consequence. Hardness tests on longitudinal sections of welds indicated the amount of tempering a weld will receive inreactor after relatively short lengths of time. The pressure burst tests proved that untemperted welds on HT9-clad fuel elements are as reliable as tempered welds; any residual stresses in untempered weld zones were of no consequence. The tempering test showed that welds used in the as-welded condition will sufficiently temper in 7 days at 550{sup 0}C, but will not, sufficiently temper in 7 days at bulk sodium temperature. A comparison of the structure of laser welds to those of CD and TIG welds indicated that untempered laser welds will perform and temper in a manner similar to the TIG welds tested in this effort.

  5. Reactor scram experience for shutdown system reliability analysis. [BWR; PWR

    Energy Technology Data Exchange (ETDEWEB)

    Edison, G.E.; Pugliese, S.L.; Sacramo, R.F.

    1976-06-01

    Scram experience in a number of operating light water reactors has been reviewed. The date and reactor power of each scram was compiled from monthly operating reports and personal communications with the operating plant personnel. The average scram frequency from ''significant'' power (defined as P/sub trip//P/sub max greater than/ approximately 20 percent) was determined as a function of operating life. This relationship was then used to estimate the total number of reactor trips from above approximately 20 percent of full power expected to occur during the life of a nuclear power plant. The shape of the scram frequency vs. operating life curve resembles a typical reliability bathtub curve (failure rate vs. time), but without a rising ''wearout'' phase due to the lack of operating data near the end of plant design life. For this case the failures are represented by ''bugs'' in the plant system design, construction, and operation which lead to scram. The number of scrams would appear to level out at an average of around three per year; the standard deviations from the mean value indicate an uncertainty of about 50 percent. The total number of scrams from significant power that could be expected in a plant designed for a 40-year life would be about 130 if no wearout phase develops near the end of life.

  6. Downwell pump reliability: Geothermal experience update: Final report

    Energy Technology Data Exchange (ETDEWEB)

    Ellis, P.F.

    1988-01-01

    Geothermal resources with temperatures between 250/sup 0/ and 360/sup 0/F (121/sup 0/C and 182/sup 0/C) are prime candidates for binary-cycle power generation, and constitute about 80% of the power-capable resources in the United States. The successful exploitation of these resources requires reliable high-capacity downwell brine production pumps, but earlier experience showed that high-capacity, high-temperature geothermal production pumps had many problems which resulted in a mean time-to-failure (MTTF) of less than 1000 h. However, steady progress has been made since 1981, and a large body of experience has been acquired by three geothermal binary plants. This survey of high-temperature geothermal downwell pump users and manufacturers updates a prior survey (AP-3572) completed in early 1983. This survey traces the development of lineshaft pump technology from the late 1970s to the present (mid-1987), detailing the advances in design, materials selection, and operating practices. Case histories of 72 lineshaft pumps installed at three geothermal binary plants since late 1981 are documented, including some detailed cause of failure reports. In the recent past, pump lives in excess of 7000 h have become common, but a high continuing rate of premature failures resulted in a mean time-to-failure (MTTF) of about 5000 h. Based on recent advances which appear likely to eliminate most premature failures, the estimated near-term MTTF will be on the order of 8000 h. The survey found almost no development of high-temperature geothermal electric submersible pumps (ESP's) or close-coupled downwell hydraulic turbopumps, and concluded that considerable development and demonstration will be needed before these technologies are able to compete with existing high-temperature geothermal lineshaft pump technology. 36 refs., 10 figs., 25 tabs.

  7. Irradiation Experiment Conceptual Design Parameters for NBSR Fuel Conversion

    Energy Technology Data Exchange (ETDEWEB)

    Brown N. R.; Brown,N.R.; Baek,J.S; Hanson, A.L.; Cuadra,A.; Cheng,L.Y.; Diamond, D.J.

    2013-03-31

    It has been proposed to convert the National Institute of Standards and Technology (NIST) research reactor, known as the NBSR, from high-enriched uranium (HEU) fuel to low-enriched uranium (LEU) fuel. The motivation to convert the NBSR to LEU fuel is to reduce the risk of proliferation of special nuclear material. This report is a compilation of relevant information from recent studies related to the proposed conversion using a metal alloy of LEU with 10 w/o molybdenum. The objective is to inform the design of the mini-plate and full-size plate irradiation experiments that are being planned. This report provides relevant dimensions of the fuel elements, and the following parameters at steady state: average and maximum fission rate density and fission density, fuel temperature distribution for the plate with maximum local temperature, and two-dimensional heat flux profiles of fuel plates with high power densities. . The latter profiles are given for plates in both the inner and outer core zones and for cores with both fresh and depleted shim arms (reactivity control devices). In addition, a summary of the methodology to obtain these results is presented.

  8. The development of a fuel cell stack electronic simulator for enhanced safety and reliability during test and training

    Energy Technology Data Exchange (ETDEWEB)

    Abdulhadi, M.; Al-Garni, M. [King AbdulAziz City for Science and Technology (KACST), Riyadh (Saudi Arabia). Energy Research Inst.

    1996-12-31

    One of the main sub-tasks of HYSOLAR, a joint Saudi-German research and development program in the field of solar hydrogen, is the investigation and characterization of phosphoric acid fuel cells (PAFC). To facilitate this, a fully automated data acquisition and control (DAC) system for fuel cell stacks was developed at KACST`s Solar Village. In order to ensure that the test and training procedures were as safe and reliable as possible, an electronic simulator for the fuel cell stacks was also developed. This paper discusses the background and concept and describes the development and operational characteristics of the simulator. (Author)

  9. Optimal Reliability-Based Planning of Experiments for POD Curves

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Faber, M. H.; Kroon, I. B.

    Optimal planning of the crack detection test is considered. The test are used to update the information on the reliability of the inspection techniques modelled by probability of detection (P.O.D.) curves. It is shown how cost-optimal and reliability based test plans can be obtained using First...

  10. Optimal Reliability-Based Planning of Experiments for POD Curves

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Faber, M. H.; Kroon, I. B.

    Optimal planning of the crack detection test is considered. The test are used to update the information on the reliability of the inspection techniques modelled by probability of detection (P.O.D.) curves. It is shown how cost-optimal and reliability based test plans can be obtained using First O...... Order Reliability Methods in combination with life-cycle cost-optimal inspection and maintenance planning. The methodology is based on preposterior analyses from Bayesian decision theory. An illustrative example is shown.......Optimal planning of the crack detection test is considered. The test are used to update the information on the reliability of the inspection techniques modelled by probability of detection (P.O.D.) curves. It is shown how cost-optimal and reliability based test plans can be obtained using First...

  11. Experiences with Two Reliability Data Collection Efforts (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Sheng, S.; Lantz, E.

    2013-08-01

    This presentation, given by NREL at the Wind Reliability Experts Meeting in Albuquerque, New Mexico, outlines the causes of wind plant operational expenditures and gearbox failures and describes NREL's efforts to create a gearbox failure database.

  12. Measurement and Its Reliability: An Introductory Laboratory Experiment

    Science.gov (United States)

    Poultney, Sherman K.

    1971-01-01

    Describes a laboratory activity about measurement and its reliability for general education students. The measurement focuses on automobile speeds and allows for estimates of errors, experimental design, and relativity in addition to kinematical concepts. (DS)

  13. Test experiences with the DaimlerChrysler: Fuel cell electric vehicle NECAR

    Directory of Open Access Journals (Sweden)

    Friedlmeier Gerardo

    2002-01-01

    Full Text Available The DalmlerChrysler fuel cell electric vehicle NECAR 4, a hydrogen-fueled zero-emission compact car based on the A-Class of Mercedes-Benz, is described. Test results obtained on the road and on the dynamometer are presented. These and other results show the high technological maturity reliability and durability already achieved with fuel cell technology.

  14. Stability and reliability of anodic biofilms under different feedstock conditions: Towards microbial fuel cell sensors

    Directory of Open Access Journals (Sweden)

    Jiseon You

    2015-12-01

    Full Text Available Stability and reliability of microbial fuel cell anodic biofilms, consisting of mixed cultures, were investigated in a continuously fed system. Two groups of anodic biofilm matured with different substrates, acetate and casein for 20–25 days, reached steady states and produced 80–87 μW and 20–29 μW consistently for 3 weeks, respectively. When the substrates were swapped, the casein-enriched group showed faster response to acetate and higher power output, compared to the acetate-enriched group. Also when the substrates were switched back to their original groups, the power output of both groups returned to the previous levels more quickly than when the substrates were swapped the first time. During the substrate change, both MFC groups showed stable power output once they reached their steady states and the output of each group with different substrates was reproducible within the same group. Community level physiological profiling also revealed the possibility of manipulating anodic biofilm metabolisms through exposure to different feedstock conditions.

  15. Fuel Performance Experiments and Modeling: Fission Gas Bubble Nucleation and Growth in Alloy Nuclear Fuels

    Energy Technology Data Exchange (ETDEWEB)

    McDeavitt, Sean [Texas A & M Univ., College Station, TX (United States); Shao, Lin [Texas A & M Univ., College Station, TX (United States); Tsvetkov, Pavel [Texas A & M Univ., College Station, TX (United States); Wirth, Brian [Univ. of Tennessee, Knoxville, TN (United States); Kennedy, Rory [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2014-04-07

    Advanced fast reactor systems being developed under the DOE's Advanced Fuel Cycle Initiative are designed to destroy TRU isotopes generated in existing and future nuclear energy systems. Over the past 40 years, multiple experiments and demonstrations have been completed using U-Zr, U-Pu-Zr, U-Mo and other metal alloys. As a result, multiple empirical and semi-empirical relationships have been established to develop empirical performance modeling codes. Many mechanistic questions about fission as mobility, bubble coalescience, and gas release have been answered through industrial experience, research, and empirical understanding. The advent of modern computational materials science, however, opens new doors of development such that physics-based multi-scale models may be developed to enable a new generation of predictive fuel performance codes that are not limited by empiricism.

  16. Testing reliability of raster - report of experiment with Kerckhoffs students

    NARCIS (Netherlands)

    Vriezekolk, Eelco

    2014-01-01

    We are working on the development of an availability risk assessment method for telecommunication services, called Raster. From previous research we know that Raster can produce assessments with reasonable effort, but we have not yet shown that its results are reliable (repeatable) and accurate (cor

  17. 14 CFR Appendix N to Part 25 - Fuel Tank Flammability Exposure and Reliability Analysis

    Science.gov (United States)

    2010-01-01

    ... temperature varies with altitude following the International Standard Atmosphere (ISA) rate of change from the... ISA rate of change is used. (3) Fuel properties: (i) For Jet A fuel, the variation of flash point...

  18. Enhancing Experiment Central Service Reliability: from delivery to security and virtualization

    CERN Document Server

    Donno, Flavia; Buzykaev, Alexey; Saiz Santos, Maria Dolores

    2011-01-01

    The four LHC experiments rely on experiment specific services running on machines mainly located at CERN. Some of these services have been rated by the experiments as very critical: any loss or degradation of performance has a major impact on the experiment's production and analysis activities. It is therefore important to provide a reliable and robust operational environment. In this work we describe the strategy based on service deployment, security and virtualization adopted to enhance the reliability of ATLAS and CMS central services.

  19. Tennessee Valley Authority validation experience with substation reliability centered maintenance

    Energy Technology Data Exchange (ETDEWEB)

    Bolton, S.M.; Graziano, J.A. [Tennessee Valley Authority, Chattanooga, TN (United States)

    1996-08-01

    This paper discusses the approach the Tennessee Valley Authority (TVA) used in the application of the Reliability Centered Maintenance (RCM) process during the evaluation of a Delle air blast circuit breaker. It discusses the selection of a system, establishing system boundaries, and the problems encountered in reviewing test data and personnel interviews. This paper also shows the functional failure analysis process, critical failure mode causes and resulting tasks. From the failure mode causes a task comparison is developed. The results from the RCM evaluation are shown as a cost savings. Finally, from this evaluation a list of conclusions and recommendations concerning the RCM validation process is provided.

  20. Penalty for Fuel Economy - System Level Perspectives on the Reliability of Hybrid Electric Vehicles During Normal and Graceful Degradation Operation

    Science.gov (United States)

    2008-08-27

    the issue of system level reliability in hybrid electric vehicles from a quantitative point of view. It also introduces a quantitative meaning to the...internal combustion engine based vehicle and later transition of those to hybrid electric vehicles . The paper intends to drive the point that in HEV...Generally people tend to think only in terms of fuel economy and additional cost premium on vehicle price while discussing about hybrid electric

  1. Optimization through experiment planning for determination of experimental conditions which guarantees the metrological reliability for analysis of chloride and sulfate in fuel alcohol; Otimizacao via planejamento de experimento para determinar as condicoes experimentais que garantam confiabilidade metrologica para analise de cloreto e sulfato em alcool combustivel

    Energy Technology Data Exchange (ETDEWEB)

    Souza e Silva, Renata; Araujo, Thiago de Oliveira [Instituto Nacional de Metrologia, Normalizacao e Qualidade Industrial (INMETRO), Duque de Caxias, RJ (Brazil)], Emails: rsouza@inmetro.gov.br, toaraujo@inmetro.gov.br; Aguiar, Paula Fernandes de [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil)], E-mail: pfaguiar@ufrj.br

    2009-07-01

    This work presents a method of analysis to determine chloride and sulfate in fuel alcohol which allowed eliminate or minimized the matrix effect in sample of fuel alcohol, using the Doehlert planning for the stage of optimization.

  2. A choice experiment on fuel taxation and earmarking in Norway

    Energy Technology Data Exchange (ETDEWEB)

    Saelen, Haakon; Kallbekken, Steffen

    2010-07-01

    Pigouvian taxes are efficient - but unpopular among voters. Earmarking of revenues has been widely reported to increase support for taxes, but this practice represents a deviation from optimal policy design. This trade-off between efficiency and political feasibility is the inspiration for this paper's attempt to quantify the effect of earmarking on voter support for fuel tax rises. Another aim of the paper is to investigate why earmarking increases support. The study estimates models of voter preferences for fuel taxes based on data are collected through a choice experiment conducted on a sample of 1177 respondents representative of the Norwegian voter population, and fitted using logistic regression models. The results show that earmarking the revenues for environmental measures has a substantial effect on voter support for fuel tax increases, garnering a majority for increases of up to 20 per cent above present levels. Earmarking the additional revenue for income redistribution does not result in a majority for any increase. Further analysis indicates that a prime reason why earmarking for environmental measures is popular is that it increases the perceived environmental effectiveness of the tax, and hence its legitimacy as an environmental rather than a fiscal policy. (Author)

  3. Calculation Analysis of San Onofre Depletion MOX Fuel Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Pavlovichev, AM

    2001-08-31

    The report provides calculation results of isotopic composition of spent MOX fuel irradiated in Sun Onofre PWR reactor. The calculation was performed by means of the MCU/BURNUP Monte Carlo code. The code is developed in Kurchatov Institute, Russia. The predicted isotope contents are compared with the measured ones. A purpose of this work is a verification both the code and the model of experiment description. Predicted plutonium content exceeds the measured one approximately by 3%. It is arise mainly from error of {sup 239}Pu isotope. Isotopic contents of the main plutonium and uranium isotopes are predicted with satisfactory precision.

  4. Development, Validity, and Reliability of the Campus Residential Experience Survey

    Science.gov (United States)

    Sriram, Rishi; Scales, Laine; Shushok, Frank, Jr.

    2017-01-01

    The importance of living on campus is well established, but extant research that examines administrator perceptions of what comprises the best educational experience for students living on campus is generally unavailable. This study reports the development of a psychometric instrument designed to uncover underlying paradigms and attitudes of…

  5. Balancing low cost with reliable operation in the rotordynamic design of the ALS Liquid Hydrogen Fuel Turbopump

    Science.gov (United States)

    Greenhill, L. M.

    1990-01-01

    The Air Force/NASA Advanced Launch System (ALS) Liquid Hydrogen Fuel Turbopump (FTP) has primary design goals of low cost and high reliability, with performance and weight having less importance. This approach is atypical compared with other rocket engine turbopump design efforts, such as on the Space Shuttle Main Engine (SSME), which emphasized high performance and low weight. Similar to the SSME turbopumps, the ALS FTP operates supercritically, which implies that stability and bearing loads strongly influence the design. In addition, the use of low cost/high reliability features in the ALS FTP such as hydrostatic bearings, relaxed seal clearances, and unshrouded turbine blades also have a negative influence on rotordynamics. This paper discusses the analysis conducted to achieve a balance between low cost and acceptable rotordynamic behavior, to ensure that the ALS FTP will operate reliably without subsynchronous instabilities or excessive bearing loads.

  6. Tiger Teams Technical Assistance: Reliable, Universal Open Architecture for Card Access to Dispense Alternative Fuels

    Energy Technology Data Exchange (ETDEWEB)

    2002-03-01

    Report discusses the dilemma of incorporating consistent, convenient, universal card access (or ''pay-at-the-pump'') systems into alternative fueling stations across the country. The state of California continues to be in the forefront of implementing alternative fuels for transportation applications. Aggressive efforts to deploy alternative fuel vehicles (AFVs) in California have highlighted the need to provide adequate fueling stations and develop appropriate, user-friendly means to purchase fuel at the pump. Since these fuels are not typically provided by petroleum companies at conventional fueling stations, and acceptance of cash is often not an option, a payment method must be developed that is consistent with the way individual AFV operators are accustomed to purchasing automotive fuels--with a credit card. At the same time, large fleets like the California Department of General Services must be able to use a single fuel card that offers comprehensive fleet management services. The Gas Technology Institute's Infrastructure Working Group (IWG) and its stakeholders have identified the lack of a common card reader system as a hurdle to wider deployment of AFVs in California and the United States. In conjunction with the U.S. Department of Energy's (DOE) National Clean Cities Program, the IWG has outlined a multi-phased strategy to systematically address the barriers to develop a more ''open'' architecture that's similar to the way gasoline and diesel are currently dispensed. Under the auspices of the IWG, survey results were gathered (circa 1999) from certain fuel providers, as a means to more carefully study card reader issues and their potential solutions. Pilot programs featuring card reader systems capable of accepting wider payment options have been attempted in several regions of the United States with mixed success. In early 2001, DOE joined the National Renewable Energy Laboratory (NREL), the

  7. HLM fuel pin bundle experiments in the CIRCE pool facility

    Energy Technology Data Exchange (ETDEWEB)

    Martelli, Daniele, E-mail: daniele.martelli@ing.unipi.it [University of Pisa, Department of Civil and Industrial Engineering, Pisa (Italy); Forgione, Nicola [University of Pisa, Department of Civil and Industrial Engineering, Pisa (Italy); Di Piazza, Ivan; Tarantino, Mariano [Italian National Agency for New Technologies, Energy and Sustainable Economic Development, C.R. ENEA Brasimone (Italy)

    2015-10-15

    Highlights: • The experimental results represent the first set of values for LBE pool facility. • Heat transfer is investigated for a 37-pin electrical bundle cooled by LBE. • Experimental data are presented together with a detailed error analysis. • Nu is computed as a function of the Pe and compared with correlations. • Experimental Nu is about 25% lower than Nu derived from correlations. - Abstract: Since Lead-cooled Fast Reactors (LFR) have been conceptualized in the frame of GEN IV International Forum (GIF), great interest has focused on the development and testing of new technologies related to HLM nuclear reactors. In this frame the Integral Circulation Experiment (ICE) test section has been installed into the CIRCE pool facility and suitable experiments have been carried out aiming to fully investigate the heat transfer phenomena in grid spaced fuel pin bundles providing experimental data in support of European fast reactor development. In particular, the fuel pin bundle simulator (FPS) cooled by lead bismuth eutectic (LBE), has been conceived with a thermal power of about 1 MW and a uniform linear power up to 25 kW/m, relevant values for a LFR. It consists of 37 fuel pins (electrically simulated) placed on a hexagonal lattice with a pitch to diameter ratio of 1.8. The FPS was deeply instrumented by several thermocouples. In particular, two sections of the FPS were instrumented in order to evaluate the heat transfer coefficient along the bundle as well as the cladding temperature in different ranks of sub-channels. Nusselt number in the central sub-channel was therefore calculated as a function of the Peclet number and the obtained results were compared to Nusselt numbers obtained from convective heat transfer correlations available in literature on Heavy Liquid Metals (HLM). Results reported in the present work, represent the first set of experimental data concerning fuel pin bundle behaviour in a heavy liquid metal pool, both in forced and

  8. Experience on management of CANDU spent fuel in Korea

    Energy Technology Data Exchange (ETDEWEB)

    Lee, H.-Y.; Choi, B.-I.; Yoon, J.-H.; Seo, U.-S. [Korea Hydro and Nuclear Power Co. Ltd., Nuclear Environment Technology Inst. (KHNP/NETEC), Yusung-Gu, Daejeon (Korea, Republic of)

    2002-07-01

    In Korea, national policy on the management of spent fuel from both PWR and CANDU reactors demands that all the spent fuel be kept within reactor site in until 2016 the time spent fuel interim storage facility might open. Based on the end of 2001, KHNP has 4 CANDU reactors in operation generating approximately 5,000 bundles of spent fuels per each unit annually. The generation, accumulation, and management of CANDU spent fuel by KHNP in Korea are reviewed. CANDU spent fuel storage technology including pool storage in fuel building, concrete silo storage, and on going project for consolidating storage adapting modular vault type MACSTOR concept are outlined. Especially current joint development of storage of CANDU spent fuel for improving land usage is addressed. The explanation of the new consolidated dry storage system includes description of the storage facility, its safety evaluations, and final implementation. Finally future movement on management of spent fuel in Korea is also briefly introduced. (author)

  9. Results of international standard problem No. 36 severe fuel damage experiment of a VVER fuel bundle

    Energy Technology Data Exchange (ETDEWEB)

    Firnhaber, M. [Gesellschaft fuer Anlagen-und Reaktorsicherheit, Koeln (Germany); Yegorova, L. [Nuclear Safety Institute of Russian Research Center, Moscow (Russian Federation); Brockmeier, U. [Ruhr-Univ. of Bochum (Germany)] [and others

    1995-09-01

    International Standard Problems (ISP) organized by the OECD are defined as comparative exercises in which predictions with different computer codes for a given physical problem are compared with each other and with a carefully controlled experimental study. The main goal of ISP is to increase confidence in the validity and accuracy of analytical tools used in assessing the safety of nuclear installations. In addition, it enables the code user to gain experience and to improve his competence. This paper presents the results and assessment of ISP No. 36, which deals with the early core degradation phase during an unmitigated severe LWR accident in a Russian type VVER. Representatives of 17 organizations participated in the ISP using the codes ATHLET-CD, ICARE2, KESS-III, MELCOR, SCDAP/RELAP5 and RAPTA. Some participants performed several calculations with different codes. As experimental basis the severe fuel damage experiment CORA-W2 was selected. The main phenomena investigated are thermal behavior of fuel rods, onset of temperature escalation, material behavior and hydrogen generation. In general, the calculations give the right tendency of the experimental results for the thermal behavior, the hydrogen generation and, partly, for the material behavior. However, some calculations deviate in important quantities - e.g. some material behavior data - showing remarkable discrepancies between each other and from the experiments. The temperature history of the bundle up to the beginning of significant oxidation was calculated quite well. Deviations seem to be related to the overall heat balance. Since the material behavior of the bundle is to a great extent influenced by the cladding failure criteria a more realistic cladding failure model should be developed at least for the detailed, mechanistic codes. Regarding the material behavior and flow blockage some models for the material interaction as well as for relocation and refreezing requires further improvement.

  10. System-level Reliability Assessment of Power Stage in Fuel Cell Application

    DEFF Research Database (Denmark)

    Zhou, Dao; Wang, Huai; Blaabjerg, Frede

    2016-01-01

    the lifetime model and the stress levels, the Weibull distribution of the power semiconductors lifetime can be obtained by using Monte Carlo analysis. Afterwards, the reliability block diagram can further be adopted to evaluate the reliability of the power stage based on the estimated power semiconductor...

  11. Recent Advances in Enzymatic Fuel Cells: Experiments and Modeling

    Directory of Open Access Journals (Sweden)

    Ivan Ivanov

    2010-04-01

    Full Text Available Enzymatic fuel cells convert the chemical energy of biofuels into electrical energy. Unlike traditional fuel cell types, which are mainly based on metal catalysts, the enzymatic fuel cells employ enzymes as catalysts. This fuel cell type can be used as an implantable power source for a variety of medical devices used in modern medicine to administer drugs, treat ailments and monitor bodily functions. Some advantages in comparison to conventional fuel cells include a simple fuel cell design and lower cost of the main fuel cell components, however they suffer from severe kinetic limitations mainly due to inefficiency in electron transfer between the enzyme and the electrode surface. In this review article, the major research activities concerned with the enzymatic fuel cells (anode and cathode development, system design, modeling by highlighting the current problems (low cell voltage, low current density, stability will be presented.

  12. Fuel element failure detection experiments, evaluation of the experiments at KNK II/1 (Intermediate Report)

    CERN Document Server

    Bruetsch, D

    1983-01-01

    In the frame of the fuel element failure detection experiments at KNK II with its first core the measurement devices of INTERATOM were taken into operation in August 1981 and were in operation almost continuously. Since the start-up until the end of the first KNK II core operation plugs with different fuel test areas were inserted in order to test the efficiency of the different measuring devices. The experimental results determined during this test phase and the gained experiences are described in this report and valuated. All three measuring techniques (Xenon adsorption line XAS, gas-chromatograph GC and precipitator PIT) could fulfil the expectations concerning their susceptibility. For XAS and GC the nuclide specific sensitivities as determined during the preliminary tests could be confirmed. For PIT the influences of different parameters on the signal yield could be determined. The sensitivity of the device could not be measured due to a missing reference measuring point.

  13. REVA Advanced Fuel Design and Codes and Methods - Increasing Reliability, Operating Margin and Efficiency in Operation

    Energy Technology Data Exchange (ETDEWEB)

    Frichet, A.; Mollard, P.; Gentet, G.; Lippert, H. J.; Curva-Tivig, F.; Cole, S.; Garner, N.

    2014-07-01

    Since three decades, AREVA has been incrementally implementing upgrades in the BWR and PWR Fuel design and codes and methods leading to an ever greater fuel efficiency and easier licensing. For PWRs, AREVA is implementing upgraded versions of its HTP{sup T}M and AFA 3G technologies called HTP{sup T}M-I and AFA3G-I. These fuel assemblies feature improved robustness and dimensional stability through the ultimate optimization of their hold down system, the use of Q12, the AREVA advanced quaternary alloy for guide tube, the increase in their wall thickness and the stiffening of the spacer to guide tube connection. But an even bigger step forward has been achieved a s AREVA has successfully developed and introduces to the market the GAIA product which maintains the resistance to grid to rod fretting (GTRF) of the HTP{sup T}M product while providing addition al thermal-hydraulic margin and high resistance to Fuel Assembly bow. (Author)

  14. Benchmark physics experiment of metallic-fueled LMFBR at FCA. 2; Experiments of FCA assembly XVI-1 and their analyses

    Energy Technology Data Exchange (ETDEWEB)

    Iijima, Susumu; Oigawa, Hiroyuki; Ohno, Akio; Sakurai, Takeshi; Nemoto, Tatsuo; Osugi, Toshitaka; Satoh, Kunio; Hayasaka, Katsuhisa [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Bando, Masaru

    1993-10-01

    An availability of data and method for a design of metallic-fueled LMFBR is examined by using the experiment results of FCA assembly XVI-1. Experiment included criticality and reactivity coefficients such as Doppler, sodium void, fuel shifting and fuel expansion. Reaction rate ratios, sample worth and control rod worth were also measured. Analysis was made by using three-dimensional diffusion calculations and JENDL-2 cross sections. Predictions of assembly XVI-1 reactor physics parameters agree reasonably well with the measured values, but for some reactivity coefficients such as Doppler, large zone sodium void and fuel shifting further improvement of calculation method was need. (author).

  15. Scoring sacroiliac joints by magnetic resonance imaging. A multiple-reader reliability experiment

    DEFF Research Database (Denmark)

    Landewe, Robert B.M.; Hermann, Kay Geert A; Van Der Heijde, Desiree M.F.M

    2005-01-01

    Magnetic resonance imaging (MRI) of the sacroiliac (SI) joints and the spine is increasingly important in the assessment of inflammatory activity and structural damage in clinical trials with patients with ankylosing spondylitis (AS). We investigated inter-reader reliability and sensitivity...... systems. Sensitivity to change differed per reader, but in general was somewhat better for the comprehensive SPARCC system. This experiment under 'real life,' far from optimal conditions demonstrates the feasibility of scoring exercises for method comparison, provides evidence for the reliability...

  16. Scoring sacroiliac joints by magnetic resonance imaging. A multiple-reader reliability experiment

    DEFF Research Database (Denmark)

    Landewe, Robert B.M.; Hermann, Kay Geert A; Van Der Heijde, Desiree M.F.M

    2005-01-01

    Magnetic resonance imaging (MRI) of the sacroiliac (SI) joints and the spine is increasingly important in the assessment of inflammatory activity and structural damage in clinical trials with patients with ankylosing spondylitis (AS). We investigated inter-reader reliability and sensitivity...... systems. Sensitivity to change differed per reader, but in general was somewhat better for the comprehensive SPARCC system. This experiment under 'real life,' far from optimal conditions demonstrates the feasibility of scoring exercises for method comparison, provides evidence for the reliability...

  17. Reliability Assessment of Fuel Cell System - A Framework for Quantitative Approach

    DEFF Research Database (Denmark)

    Lee, Shinae; Zhou, Dao; Wang, Huai

    2016-01-01

    such as component failures, the system architecture, and operational strategies. This paper suggests an approach that includes Failure Modes and Effects Analysis (FMEA), Fault Tree Analysis (FTA), and Reliability Block Diagram (RBD). For a case study, and the service lifetime of a commercial 5 kW Proton Exchange...

  18. Project Description Advanced Fuel Cycle Initiative AFC-2A and AFC-2B Experiments

    Energy Technology Data Exchange (ETDEWEB)

    AFCI AFC-2A and AFC-2B Experiments Project Executi

    2007-03-01

    The proposed AFC-2A and AFC-2B irradiation experiments are a continuation of the AFC-1 fuel test series currently in progress in the ATR. This document discusses the experiments and the planned activities that will take place.

  19. Traveling-wave tube reliability estimates, life tests, and space flight experience

    Science.gov (United States)

    Lalli, V. R.; Speck, C. E.

    1977-01-01

    Infant mortality, useful life, and wearout phase of twt life are considered. The performance of existing developmental tubes, flight experience, and sequential hardware testing are evaluated. The reliability history of twt's in space applications is documented by considering: (1) the generic parts of the tube in light of the manner in which their design and operation affect the ultimate reliability of the device, (2) the flight experience of medium power tubes, and (3) the available life test data for existing space-qualified twt's in addition to those of high power devices.

  20. Aircraft emissions of methane and nitrous oxide during the alternative aviation fuel experiment.

    Science.gov (United States)

    Santoni, Gregory W; Lee, Ben H; Wood, Ezra C; Herndon, Scott C; Miake-Lye, Richard C; Wofsy, Steven C; McManus, J Barry; Nelson, David D; Zahniser, Mark S

    2011-08-15

    Given the predicted growth of aviation and the recent developments of alternative aviation fuels, quantifying methane (CH(4)) and nitrous oxide (N(2)O) emission ratios for various aircraft engines and fuels can help constrain projected impacts of aviation on the Earth's radiative balance. Fuel-based emission indices for CH(4) and N(2)O were quantified from CFM56-2C1 engines aboard the NASA DC-8 aircraft during the first Alternative Aviation Fuel Experiment (AAFEX-I) in 2009. The measurements of JP-8 fuel combustion products indicate that at low thrust engine states (idle and taxi, or 4% and 7% maximum rated thrusts, respectively) the engines emit both CH(4) and N(2)O at a mean ± 1σ rate of 170 ± 160 mg CH(4) (kg Fuel)(-1) and 110 ± 50 mg N(2)O (kg Fuel)(-1), respectively. At higher thrust levels corresponding to greater fuel flow and higher engine temperatures, CH(4) concentrations in engine exhaust were lower than ambient concentrations. Average emission indices for JP-8 fuel combusted at engine thrusts between 30% and 100% of maximum rating were -54 ± 33 mg CH(4) (kg Fuel)(-1) and 32 ± 18 mg N(2)O (kg Fuel)(-1), where the negative sign indicates consumption of atmospheric CH(4) in the engine. Emission factors for the synthetic Fischer-Tropsch fuels were statistically indistinguishable from those for JP-8.

  1. Additional experiments on flowability improvements of aviation fuels at low temperatures, volume 2

    Science.gov (United States)

    Stockemer, F. J.; Deane, R. L.

    1982-01-01

    An investigation was performed to study flow improver additives and scale-model fuel heating systems for use with aviation hydrocarbon fuel at low temperatures. Test were performed in a facility that simulated the heat transfer and temperature profiles anticipated in wing fuel tanks during flight of long-range commercial aircraft. The results are presented of experiments conducted in a test tank simulating a section of an outer wing integral fuel tank approximately full-scale in height, chilled through heat exchange panels bonded to the upper and lower horizontal surfaces. A separate system heated lubricating oil externally by a controllable electric heater, to transfer heat to fuel pumped from the test tank through an oil-to-fuel heat exchanger, and to recirculate the heated fuel back to the test tank.

  2. H2FIRST: A partnership to advance hydrogen fueling station technology driving an optimal consumer experience.

    Energy Technology Data Exchange (ETDEWEB)

    Moen, Christopher D.; Dedrick, Daniel E.; Pratt, Joseph William; Balfour, Bruce; Noma, Edwin Yoichi; Somerday, Brian P.; San Marchi, Christopher W.; K. Wipke; J. Kurtz; D. Terlip; K. Harrison; S. Sprik

    2014-03-01

    The US Department of Energy (DOE) Energy Efficiency and Renewable Energy (EERE) Office of Fuel Cell Technologies Office (FCTO) is establishing the Hydrogen Fueling Infrastructure Research and Station Technology (H2FIRST) partnership, led by the National Renewable Energy Laboratory (NREL) and Sandia National Laboratories (SNL). FCTO is establishing this partnership and the associated capabilities in support of H2USA, the public/private partnership launched in 2013. The H2FIRST partnership provides the research and technology acceleration support to enable the widespread deployment of hydrogen infrastructure for the robust fueling of light-duty fuel cell electric vehicles (FCEV). H2FIRST will focus on improving private-sector economics, safety, availability and reliability, and consumer confidence for hydrogen fueling. This whitepaper outlines the goals, scope, activities associated with the H2FIRST partnership.

  3. Reliability of Objective Structured Clinical Examinations: Four Years of Experience in a Surgical Clerkship.

    Science.gov (United States)

    Mann, Karen V.; And Others

    1990-01-01

    Four years of experience with an objective structured clinical examination (OSCE) following an eight-week surgical clerkship (n=356 students) are reported, including data on mean student performance across years, reliability coefficients, and generalizability. Implications for improvement and development of OSCE are discussed. (Author/MSE)

  4. Reliability of measuring anomalous experience: the Bonn Scale for the Assessment of Basic Symptoms

    DEFF Research Database (Denmark)

    Vollmer-Larsen, Anne; Handest, Peter; Parnas, Josef

    2007-01-01

    Studying subjective experience, apart from preformed self-rating questionnaires, has nearly vanished in psychiatry, partly due to reliability concerns. Recent research in early detection of schizophrenia has entailed an increasing interest in the subtle experiential anomalies that may assist in i...

  5. Service validity and service reliability of search, experience and credence services: A scenario study

    NARCIS (Netherlands)

    Galetzka, Mirjam; Verhoeven, Joost W.M.; Pruyn, Ad Th.H.

    2006-01-01

    The purpose of this research is to add to our understanding of the antecedents of customer satisfaction by examining the effects of service reliability (Is the service “correctly” produced?) and service validity (Is the “correct” service produced?) of search, experience and credence services. Design

  6. Foreign experience on effects of extended dry storage on the integrity of spent nuclear fuel

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, K.J.; Mitchell, S.J.

    1992-04-01

    This report summarizes the results of a survey of foreign experience in dry storage of spent fuel from nuclear power reactors that was carried out for the US Department of Energy`s (DOE) Office of Civilian Radioactive Waste Management (OCRWM). The report reviews the mechanisms for degradation of spent fuel cladding and fuel materials in dry storage, identifies the status and plans of world-wide experience and applications, and documents the available information on the expected long-term integrity of the dry-stored spent fuel from actual foreign experience. Countries covered in this survey are: Argentina, Canada, Federal Republic of Germany (before reunification with the former East Germany), former German Democratic Republic (former East Germany), France, India, Italy, Japan, South Korea, Spain, Switzerland, United Kingdom, and the former USSR (most of these former Republics are now in the Commonwealth of Independent States [CIS]). Industrial dry storage of Magnox fuels started in 1972 in the United Kingdom; Canada began industrial dry storage of CANDU fuels in 1980. The technology for safe storage is generally considered to be developed for time periods of 30 to 100 years for LWR fuel in inert gas and for some fuels in oxidizing gases at low temperatures. Because it will probably be decades before countries will have a repository for spent fuels and high-level wastes, the plans for expanded use of dry storage have increased significantly in recent years and are expected to continue to increase in the near future.

  7. Foreign experience on effects of extended dry storage on the integrity of spent nuclear fuel

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, K.J.; Mitchell, S.J.

    1992-04-01

    This report summarizes the results of a survey of foreign experience in dry storage of spent fuel from nuclear power reactors that was carried out for the US Department of Energy's (DOE) Office of Civilian Radioactive Waste Management (OCRWM). The report reviews the mechanisms for degradation of spent fuel cladding and fuel materials in dry storage, identifies the status and plans of world-wide experience and applications, and documents the available information on the expected long-term integrity of the dry-stored spent fuel from actual foreign experience. Countries covered in this survey are: Argentina, Canada, Federal Republic of Germany (before reunification with the former East Germany), former German Democratic Republic (former East Germany), France, India, Italy, Japan, South Korea, Spain, Switzerland, United Kingdom, and the former USSR (most of these former Republics are now in the Commonwealth of Independent States (CIS)). Industrial dry storage of Magnox fuels started in 1972 in the United Kingdom; Canada began industrial dry storage of CANDU fuels in 1980. The technology for safe storage is generally considered to be developed for time periods of 30 to 100 years for LWR fuel in inert gas and for some fuels in oxidizing gases at low temperatures. Because it will probably be decades before countries will have a repository for spent fuels and high-level wastes, the plans for expanded use of dry storage have increased significantly in recent years and are expected to continue to increase in the near future.

  8. Reliability of Physician-Level Measures of Patient Experience in Primary Care.

    Science.gov (United States)

    Fenton, Joshua J; Jerant, Anthony; Kravitz, Richard L; Bertakis, Klea D; Tancredi, Daniel J; Magnan, Elizabeth M; Franks, Peter

    2017-09-12

    Patient experience measures are widely used to compare performance at the individual physician level. To assess the impact of unmeasured patient characteristics on visit-level patient experience measures and the sample sizes required to reliably measure patient experience at the primary care physician (PCP) level. Repeated cross-sectional design. Academic family medicine practice in California. One thousand one hundred forty-one adult patients attending 1319 visits with 56 PCPs (including 45 resident and 11 faculty physicians). Post-visit patient experience surveys including patient measures used for standard adjustment as recommend by the Consumer Assessment of Healthcare Providers and Systems (CAHPS) Consortium and additional patient characteristics used for expanded adjustment (including attitudes toward healthcare, global life satisfaction, patient personality, current symptom bother, and marital status). The amount of variance in patient experience explained doubled with expanded adjustment for patient characteristics compared with standard adjustment (R(2) = 20.0% vs. 9.6%, respectively). With expanded adjustment, the amount of variance attributable to the PCP dropped from 6.1% to 3.4% and the required sample size to achieve a reliability of 0.90 in the physician-level patient experience measure increased from 138 to 255 patients per physician. After ranking of the 56 PCPs by average patient experience, 8 were reclassified into or out of the top or bottom quartiles of average experience with expanded as compared to standard adjustment [14.3% (95% CI: 7.0-25.2%)]. Widely used methods for measuring PCP-level patient experience may not account sufficiently for influential patient characteristics. If methods were adapted to account for these characteristics, patient sample sizes for reliable between-physician comparisons may be too large for most practices to obtain.

  9. Experience of IEA-R1 research reactor spent fuel transportation back to United States

    Energy Technology Data Exchange (ETDEWEB)

    Frajndlich, Roberto [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil). Div. de Operacao do Reator IEAR-R1m]. E-mail: frajndli@net.ipen.br; Perrotta, Jose A. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil). Div.de Engenharia do Nucleo]. E-mail: perrotta@net.ipen.br; Maiorino, Jose Rubens [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil). Diretoria de Reatores]. E-mail: maiorino@net.ipen.br; Soares, Adalberto Jose [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil). Dept. de Reatores]. E-mail: ajsoares@net.ipen.br

    1998-07-01

    IPEN/CNEN-SP is sending the IEA-R1 Research Reactor spent fuels from USA origin back to this country. This paper describes the experience in organizing the negotiations, documents and activities to perform the transport. Subjects as cask licensing, transport licensing and fuel failure criteria for transportation are presented. (author)

  10. Advanced Gas Reactor (AGR)-5/6/7 Fuel Irradiation Experiments in the Advanced Test Reactor

    Energy Technology Data Exchange (ETDEWEB)

    A. Joseph Palmer; David A. Petti; S. Blaine Grover

    2014-04-01

    The United States Department of Energy’s Very High Temperature Reactor (VHTR) Advanced Gas Reactor (AGR) Fuel Development and Qualification Program will be irradiating up to seven separate low enriched uranium (LEU) tri-isotopic (TRISO) particle fuel (in compact form) experiments in the Advanced Test Reactor (ATR) located at the Idaho National Laboratory (INL). These irradiations and fuel development are being accomplished to support development of the next generation reactors in the United States. The goals of the irradiation experiments are to provide irradiation performance data to support fuel process development, to qualify fuel for normal operating conditions, to support development and validation of fuel performance and fission product transport models and codes, and to provide irradiated fuel and materials for post irradiation examination (PIE) and safety testing. The experiments, which each consist of at least five separate capsules, are being irradiated in an inert sweep gas atmosphere with individual on-line temperature monitoring and control of each capsule. The sweep gases also have on-line fission product monitoring the effluent from each capsule to track performance of the fuel during irradiation. The first two experiments (designated AGR-1 and AGR-2), have been completed. The third and fourth experiments have been combined into a single experiment designated AGR-3/4, which started its irradiation in December 2011 and is currently scheduled to be completed in April 2014. The design of the fuel qualification experiment, designated AGR-5/6/7, is well underway and incorporates lessons learned from the three previous experiments. Various design issues will be discussed with particular details related to selection of thermometry.

  11. Status of the NGNP Fuel Experiment AGR-2 Irradiated in the Advanced Test Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Blaine Grover

    2012-10-01

    The United States Department of Energy’s Next Generation Nuclear Plant (NGNP) Advanced Gas Reactor (AGR) Fuel Development and Qualification Program will be irradiating up to seven separate low enriched uranium (LEU) tri-isotopic (TRISO) particle fuel (in compact form) experiments in the Advanced Test Reactor (ATR) located at the Idaho National Laboratory (INL). These irradiations and fuel development are being accomplished to support development of the next generation reactors in the United States, and will be irradiated over the next several years to demonstrate and qualify new TRISO coated particle fuel for use in high temperature gas reactors. The goals of the irradiation experiments are to provide irradiation performance data to support fuel process development, to qualify fuel for normal operating conditions, to support development and validation of fuel performance and fission product transport models and codes, and to provide irradiated fuel and materials for post irradiation examination (PIE) and safety testing. The experiments, which will each consist of at least six separate capsules, will be irradiated in an inert sweep gas atmosphere with individual on-line temperature monitoring and control of each capsule. The sweep gas will also have on-line fission product monitoring on its effluent to track performance of the fuel in each individual capsule during irradiation. The first experiment (designated AGR-1) started irradiation in December 2006 and was completed in November 2009. The second experiment (AGR-2), which utilized the same experiment design as well as control and monitoring systems as AGR-1, started irradiation in June 2010 and is currently scheduled to be completed in April 2013. The design of this experiment and support systems will be briefly discussed, followed by the progress and status of the experiment to date.

  12. Nuclear imaging of the fuel assembly in ignition experiments

    Energy Technology Data Exchange (ETDEWEB)

    Grim, G. P.; Guler, N.; Merrill, F. E.; Morgan, G. L.; Danly, C. R.; Volegov, P. L.; Wilde, C. H.; Wilson, D. C.; Clark, D. S.; Hinkel, D. E.; Jones, O. S.; Raman, K. S.; Izumi, N.; Fittinghoff, D. N.; Drury, O. B.; Alger, E. T.; Arnold, P. A.; Ashabranner, R. C.; Atherton, L. J.; Barrios, M. A.; Batha, S.; Bell, P. M.; Benedetti, L. R.; Berger, R. L.; Bernstein, L. A.; Berzins, L. V.; Betti, R.; Bhandarkar, S. D.; Bionta, R. M.; Bleuel, D. L.; Boehly, T. R.; Bond, E. J.; Bowers, M. W.; Bradley, D. K.; Brunton, G. K.; Buckles, R. A.; Burkhart, S. C.; Burr, R. F.; Caggiano, J. A.; Callahan, D. A.; Casey, D. T.; Castro, C.; Celliers, P. M.; Cerjan, C. J.; Chandler, G. A.; Choate, C.; Cohen, S. J.; Collins, G. W.; Cooper, G. W.; Cox, J. R.; Cradick, J. R.; Datte, P. S.; Dewald, E. L.; Di Nicola, P.; Di Nicola, J. M.; Divol, L.; Dixit, S. N.; Dylla-Spears, R.; Dzenitis, E. G.; Eckart, M. J.; Eder, D. C.; Edgell, D. H.; Edwards, M. J.; Eggert, J. H.; Ehrlich, R. B.; Erbert, G. V.; Fair, J.; Farley, D. R.; Felker, B.; Fortner, R. J.; Frenje, J. A.; Frieders, G.; Friedrich, S.; Gatu-Johnson, M.; Gibson, C. R.; Giraldez, E.; Glebov, V. Y.; Glenn, S. M.; Glenzer, S. H.; Gururangan, G.; Haan, S. W.; Hahn, K. D.; Hammel, B. A.; Hamza, A. V.; Hartouni, E. P.; Hatarik, R.; Hatchett, S. P.; Haynam, C.; Hermann, M. R.; Herrmann, H. W.; Hicks, D. G.; Holder, J. P.; Holunga, D. M.; Horner, J. B.; Hsing, W. W.; Huang, H.; Jackson, M. C.; Jancaitis, K. S.; Kalantar, D. H.; Kauffman, R. L.; Kauffman, M. I.; Khan, S. F.; Kilkenny, J. D.; Kimbrough, J. R.; Kirkwood, R.; Kline, J. L.; Knauer, J. P.; Knittel, K. M.; Koch, J. A.; Kohut, T. R.; Kozioziemski, B. J.; Krauter, K.; Krauter, G. W.; Kritcher, A. L.; Kroll, J.; Kyrala, G. A.; Fortune, K. N. La; LaCaille, G.; Lagin, L. J.; Land, T. A.; Landen, O. L.; Larson, D. W.; Latray, D. A.; Leeper, R. J.; Lewis, T. L.; LePape, S.; Lindl, J. D.; Lowe-Webb, R. R.; Ma, T.; MacGowan, B. J.; MacKinnon, A. J.; MacPhee, A. G.; Malone, R. M.; Malsbury, T. N.; Mapoles, E.; Marshall, C. D.; Mathisen, D. G.; McKenty, P.; McNaney, J. M.; Meezan, N. B.; Michel, P.; Milovich, J. L.; Moody, J. D.; Moore, A. S.; Moran, M. J.; Moreno, K.; Moses, E. I.; Munro, D. H.; Nathan, B. R.; Nelson, A. J.; Nikroo, A.; Olson, R. E.; Orth, C.; Pak, A. E.; Palma, E. S.; Parham, T. G.; Patel, P. K.; Patterson, R. W.; Petrasso, R. D.; Prasad, R.; Ralph, J. E.; Regan, S. P.; Rinderknecht, H.; Robey, H. F.; Ross, G. F.; Ruiz, C. L.; Seguin, F. H.; Salmonson, J. D.; Sangster, T. C.; Sater, J. D.; Saunders, R. L.; Schneider, M. B.; Schneider, D. H.; Shaw, M. J.; Simanovskaia, N.; Spears, B. K.; Springer, P. T.; Stoeckl, C.; Stoeffl, W.; Suter, L. J.; Thomas, C. A.; Tommasini, R.; Town, R. P.; Traille, A. J.; Wonterghem, B. Van; Wallace, R. J.; Weaver, S.; Weber, S. V.; Wegner, P. J.; Whitman, P. K.; Widmann, K.; Widmayer, C. C.; Wood, R. D.; Young, B. K.; Zacharias, R. A.; Zylstra, A.

    2013-05-01

    First results from the analysis of neutron image data collected on implosions of cryogenically layered deuterium-tritium capsules during the 2011-2012 National Ignition Campaign are reported. The data span a variety of experimental designs aimed at increasing the stagnation pressure of the central hotspot and areal density of the surrounding fuel assembly. Images of neutrons produced by deuterium–tritium fusion reactions in the hotspot are presented, as well as images of neutrons that scatter in the surrounding dense fuel assembly. The image data are compared with 1D and 2D model predictions, and consistency checked using other diagnostic data. The results indicate that the size of the fusing hotspot is consistent with the model predictions, as well as other imaging data, while the overall size of the fuel assembly, inferred from the scattered neutron images, is systematically smaller than models’ prediction. Preliminary studies indicate these differences are consistent with a significant fraction (20%–25%) of the initial deuterium-tritium fuel mass outside the compact fuel assembly, due either to low mode mass asymmetry or high mode 3D mix effects at the ablator-ice interface.

  13. Laguna Verde BWRs operational experience: steady-state fuel performance

    Energy Technology Data Exchange (ETDEWEB)

    Cuevas V, G. F.; Bravo S, J. M. [Global Nuclear Fuel - Americas, 3901 Castle Hayne Road, Wilmington, 28401 North Carolina (United States); Casillas, J. L., E-mail: gabriel.cuevas-vivas@gnf.co [General Electric Hitachi Nuclear Energy, 1989 Little Orchard St. Romm 239, San Jose, 95125 California (United States)

    2010-10-15

    The two BWR at Laguna Verde nuclear power station are finishing 21 and 15 years of continuous successful operation as of 2010. During Unit 1 and 2 commercial operations only Ge/GNF fuel designs have been employed; fuel lattice designs 8 x 8 and 10 x 10 were used at the reactor, with an original licensed thermal power (OLTP: 1931 MWt) and the reactor's first power up-rates of 5%. GNF fuel will be also used for the second EPU to reach 120% of OLTP in the near future. Thermal and gamma traversing in-core probes (Tip) are used for power monitoring purposes along with the Ge (now GNF-A) core monitoring system, 3-dimensional Monicore{sup TM}. GNF-A has also participated by preparing the core management plan that is regularly fine-tuned in collaboration with Comision Federal de Electricidad (CFE owner of the Laguna Verde reactors). For determination of thermal margins and eigenvalue prediction, GNF-A employs the NRC-licensed steady-state core simulator PANAC11. Tip comparisons are routinely used to adapt power distributions for a better thermal margin calculation. Over the years, several challenges have appeared in the near and long term fuel management planning such as increasing cycle length, optimization of the thermal margins, rated power increase, etc. Each challenge has been successfully overcome via operational strategy, code improvements and better fuel designs. This paper summarizes Laguna Verde Unit 1 and 2 steady-state performance from initial commercial operation, with a discussion of the nuclear and thermal-hydraulic design features, as well as of the operational strategies that set and interesting benchmark for future fuel applications, code development and operation of the BWRs. (Author)

  14. FLOWSHEET EVALUATION FOR THE DISSOLVING AND NEUTRALIZATION OF SODIUM REACTOR EXPERIMENT USED NUCLEAR FUEL

    Energy Technology Data Exchange (ETDEWEB)

    Daniel, W. E.; Hansen, E. K.; Shehee, T. C.

    2012-10-30

    This report includes the literature review, hydrogen off-gas calculations, and hydrogen generation tests to determine that H-Canyon can safely dissolve the Sodium Reactor Experiment (SRE; thorium fuel), Ford Nuclear Reactor (FNR; aluminum alloy fuel), and Denmark Reactor (DR-3; silicide fuel, aluminum alloy fuel, and aluminum oxide fuel) assemblies in the L-Bundles with respect to the hydrogen levels in the projected peak off-gas rates. This is provided that the number of L-Bundles charged to the dissolver is controlled. Examination of SRE dissolution for potential issues has aided in predicting the optimal batching scenario. The calculations detailed in this report demonstrate that the FNR, SRE, and DR-3 used nuclear fuel (UNF) are bounded by MURR UNF and may be charged using the controls outlined for MURR dissolution in a prior report.

  15. Experience of air transport of nuclear fuel material in Japan

    Energy Technology Data Exchange (ETDEWEB)

    Yamashita, T.; Toguri, D. [Transnuclear, LTD. (AREVA group), Tokyo (Japan); Kawasaki, M. [Japan Nuclear Cycle Development Inst., Muramatsu, Ibaraki (Japan)

    2004-07-01

    Certified Reference Materials (hereafter called as to CRMs), which are indispensable for Quality Assurance and Material Accountability in nuclear fuel plants, are being provided by overseas suppliers to Japanese nuclear entities as Type A package (non-fissile) through air transport. However, after the criticality accident at JCO in Japan, special law defining nuclear disaster countermeasures (hereafter called as to the LAW) has been newly enforced in June 2000. Thereafter, nuclear fuel materials must meet not only to the existing transport regulations but also to the LAW for its transport.

  16. Calculation of the radionuclides in PWR spent fuel samples for SFR experiment planning.

    Energy Technology Data Exchange (ETDEWEB)

    Naegeli, Robert Earl

    2004-06-01

    This report documents the calculation of radionuclide content in the pressurized water reactor (PWR) spent fuel samples planned for use in the Spent Fuel Ratio (SPR) Experiments at Sandia National Laboratories, Albuquerque, New Mexico (SNL) to aid in experiment planning. The calculation methods using the ORIGEN2 and ORIGEN-ARP computer codes and the input modeling of the planned PWR spent fuel from the H. B. Robinson and the Surry nuclear power plants are discussed. The safety hazards for the calculated nuclide inventories in the spent fuel samples are characterized by the potential airborne dose and by the portion of the nuclear facility hazard category 2 and 3 thresholds that the experiment samples would present. In addition, the gamma ray photon energy source for the nuclide inventories is tabulated to facilitate subsequent calculation of the direct and shielded dose rates expected from the samples. The relative hazards of the high burnup 72 gigawatt-day per metric ton of uranium (GWd/MTU) spent fuel from H. B. Robinson and the medium burnup 36 GWd/MTU spent fuel from Surry are compared against a parametric calculation of various fuel burnups to assess the potential for higher hazard PWR fuel samples.

  17. OPTIMUM PLANNING OF EXPERIMENTS AT MODELING FUEL CONSUMPTION IN INTERNAL COMBUSTION ENGINES

    Directory of Open Access Journals (Sweden)

    N. Koshevoy

    2009-01-01

    Full Text Available The efficiency of optimum experiments planning by cost expenses at studying the processes of fuel consumption internal combustion engines is shown. The mathematical models of these processes in different state of engine working are synthesized.

  18. The Study on Fatigue Experiment and Reliability Life of Submarine Pipeline Steel

    Directory of Open Access Journals (Sweden)

    Yan Yifei

    2013-02-01

    Full Text Available The aim of the fatigue experiment study is to solve the fatigue fracture problem of X70 submarine tubing when it is under the scouring effect of offshore current. The multilevel fatigue experiments are carried out following the internation (GB4337-84 recommended method. The standard round bar fatigue specimen was made by the material of submarine pipeline steel. The fatigue life of submarine pipeline steel in different survival probability and P-S-N curve were achieved. According to reliability numerical analysis method, the reliability fatigue life of pipeline steel in different stress level is got. The results show that the fatigue life of X70 submarine pipeline steel obeys the normal distribution. The detection of submarine pipeline scouring condation should be enhanced and the pipeline zone which was scoured seriously should be repaired and controlled effectively in order to reduce the scouring effect of ocean current.

  19. Halden Gd fuel experiments IFA-515, IFA-636 and IFA-681

    Energy Technology Data Exchange (ETDEWEB)

    Tolonen, Pekka; Tverberg, Terje

    2004-07-01

    The nuclear power industry has used gadolinia (Gd) as a burnable poison widely in Boiling Water Reactors (BWR) since the 1970's, and its use in Pressurised Water Reactors (PWR) as well has become common since the 1990's. Given the poorer thermal conductivity of Gd bearing fuels in comparison with UO{sub 2} fuels, the Gd fuel power and discharge burnup are generally limited by lower enrichment to compensate for the relatively higher fuel temperature. The global tendency of increasing discharge burnup and thus operating powers to improve fuel economy brings about a demand to improve the knowledge on the thermal-mechanical performance characteristics of Gd bearing fuels and hence, reduce the reactivity penalty due to large margins in fuel design and low enrichment. Aiming to respond to the demand for more profound knowledge on Gd fuel performance, the OECD Halden Reactor Project is conducting a series of Gd experiments, which started with the special Gd fuel experiment IFA-515.10 from 1994 to 2000. The experiment was dedicated to the thermal conductivity study of non absorbing low diameter Gd fuel pellets up to an average burnup of 76 MWd/kgUO{sub 2}. Since 1998 it has been followed by an comparative integral Gd/UO{sub 2} fuel performance experiment IFA-636.1 loaded with production line pellets fabricated by ENUSA. This experiment has generated data on key thermal-mechanical performance issues, such as fuel densification and swelling and fission gas release. However, two instrumentation failures resulted in partial loss of data from the experiment and the low initial operating power in Gd rods left doubts about the initial fuel densification results. The experiment has accumulated maximum burnup of approx25 MWd/kgUO{sub 2} in Gd fuel, and will be discharged in 2004. Some of the rods will be subjected to post irradiation examinations (PIE) at the Kjeller hot cell laboratory, while options exist to load selected rods into other experiment rigs for further

  20. Survey of Worldwide Light Water Reactor Experience with Mixed Uranium-Plutonium Oxide Fuel

    Energy Technology Data Exchange (ETDEWEB)

    Cowell, B.S.; Fisher, S.E.

    1999-02-01

    The US and the Former Soviet Union (FSU) have recently declared quantities of weapons materials, including weapons-grade (WG) plutonium, excess to strategic requirements. One of the leading candidates for the disposition of excess WG plutonium is irradiation in light water reactors (LWRs) as mixed uranium-plutonium oxide (MOX) fuel. A description of the MOX fuel fabrication techniques in worldwide use is presented. A comprehensive examination of the domestic MOX experience in US reactors obtained during the 1960s, 1970s, and early 1980s is also presented. This experience is described by manufacturer and is also categorized by the reactor facility that irradiated the MOX fuel. A limited summary of the international experience with MOX fuels is also presented. A review of MOX fuel and its performance is conducted in view of the special considerations associated with the disposition of WG plutonium. Based on the available information, it appears that adoption of foreign commercial MOX technology from one of the successful MOX fuel vendors will minimize the technical risks to the overall mission. The conclusion is made that the existing MOX fuel experience base suggests that disposition of excess weapons plutonium through irradiation in LWRs is a technically attractive option.

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

    Science.gov (United States)

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

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

  2. Fission Product Monitoring of TRISO Coated Fuel For The Advanced Gas Reactor -1 Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Dawn M. Scates; John (Jack) K Hartwell; John B. Walter

    2008-09-01

    The US Department of Energy has embarked on a series of tests of TRISO-coated particle reactor fuel intended for use in the Very High Temperature Reactor (VHTR) as part of the Advanced Gas Reactor (AGR) program. The AGR-1 TRISO fuel experiment, currently underway, is the first in a series of eight fuel tests planned for irradiation in the Advanced Test Reactor (ATR) located at the Idaho National Laboratory (INL). The AGR-1 experiment reached a peak compact averaged burn up of 9% FIMA with no known TRISO fuel particle failures in March 2008. The burnup goal for the majority of the fuel compacts is to have a compact averaged burnup greater than 18% FIMA and a minimum compact averaged burnup of 14% FIMA. At the INL the TRISO fuel in the AGR-1 experiment is closely monitored while it is being irradiated in the ATR. The effluent monitoring system used for the AGR-1 fuel is the Fission Product Monitoring System (FPMS). The FPMS is a valuable tool that provides near real-time data indicative of the AGR-1 test fuel performance and incorporates both high-purity germanium (HPGe) gamma-ray spectrometers and sodium iodide [NaI(Tl)] scintillation detector-based gross radiation monitors. To quantify the fuel performance, release-to-birth ratios (R/B’s) of radioactive fission gases are computed. The gamma-ray spectra acquired by the AGR-1 FPMS are analyzed and used to determine the released activities of specific fission gases, while a dedicated detector provides near-real time count rate information. Isotopic build up and depletion calculations provide the associated isotopic birth rates. This paper highlights the features of the FPMS, encompassing the equipment, methods and measures that enable the calculation of the release-to-birth ratios. Some preliminary results from the AGR-1 experiment are also presented.

  3. Designing Fault-Injection Experiments for the Reliability of Embedded Systems

    Science.gov (United States)

    White, Allan L.

    2012-01-01

    This paper considers the long-standing problem of conducting fault-injections experiments to establish the ultra-reliability of embedded systems. There have been extensive efforts in fault injection, and this paper offers a partial summary of the efforts, but these previous efforts have focused on realism and efficiency. Fault injections have been used to examine diagnostics and to test algorithms, but the literature does not contain any framework that says how to conduct fault-injection experiments to establish ultra-reliability. A solution to this problem integrates field-data, arguments-from-design, and fault-injection into a seamless whole. The solution in this paper is to derive a model reduction theorem for a class of semi-Markov models suitable for describing ultra-reliable embedded systems. The derivation shows that a tight upper bound on the probability of system failure can be obtained using only the means of system-recovery times, thus reducing the experimental effort to estimating a reasonable number of easily-observed parameters. The paper includes an example of a system subject to both permanent and transient faults. There is a discussion of integrating fault-injection with field-data and arguments-from-design.

  4. Benchmark experiment for physics parameters of metallic-fueled LMFBR at FCA

    Energy Technology Data Exchange (ETDEWEB)

    Iijima, S.; Oigawa, H.; Sakurai, T.; Nemoto, T.; Okajima, S. [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1996-09-01

    The calculated prediction for reactor physics parameters in a metallic-fueled LMFBR was tested using the benchmark experiments performed at FCA. The reactivity feedback parameters such as sodium void worth, Doppler reactivity worth and {sup 238}U-capture-to-{sup 239}Pu -fission ratio have been measured. The fuel expansion reactivity has also measured. Direct comparison with the results from similar oxide fuel assembly was made. Analysis was done with the JENDL-2 cross section library and JENDL-3.2. Prediction of reactor physics parameters with JENDL-3.2 in the metallic-fueled core agreed reasonably well with the measured values and showed similar trend to the results in the oxide fuel core. (author)

  5. NSRR experiment with un-irradiated uranium-zirconium hydride fuel. Design, fabrication process and inspection data of test fuel rod

    Energy Technology Data Exchange (ETDEWEB)

    Sasajima, Hideo; Fuketa, Toyoshi; Ishijima, Kiyomi; Kuroha, Hiroshi; Ikeda, Yoshikazu [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Aizawa, Keiichi

    1998-08-01

    An experiment plan is progressing in the Nuclear Safety Research Reactor (NSRR) to perform pulse-irradiation with uranium-zirconium hydride (U-ZrH{sub x}) fuel. This fuel is widely used in the training research and isotope production reactor of GA (TRIGA). The objectives of the experiment are to determine the fuel rod failure threshold and to investigate fuel behavior under simulated reactivity initiated accident (RIA) conditions. This report summarizes design, fabrication process and inspection data of the test fuel rods before pulse-irradiation. The experiment with U-ZrH{sub x} fuel will realize precise safety evaluation, and improve the TRIGA reactor performance. The data to be obtained in this program will also contribute development of next-generation TRIGA reactor and its safety evaluation. (author)

  6. Solid recovered fuel: An experiment on classification and potential applications.

    Science.gov (United States)

    Bessi, C; Lombardi, L; Meoni, R; Canovai, A; Corti, A

    2016-01-01

    The residual urban waste of Prato district (Italy) is characterized by a high calorific value that would make it suitable for direct combustion in waste-to-energy plants. Since the area of central Italy lacks this kind of plant, residual municipal waste is quite often allocated to mechanical treatment plants in order to recover recyclable materials (such as metals) and energy content, sending the dry fractions to waste-to-energy plants outside the region. With the previous Italian legislation concerning Refuse Derived Fuels, only the dry stream produced as output by the study case plant, considered in this study, could be allocated to energy recovery, while the other output flows were landfilled. The most recent Italian regulation, introduced a new classification for the fuel streams recovered from waste following the criteria of the European standard (EN 15359:2011), defining the Solid Recovered Fuel (SRF). In this framework, the aim of this study was to check whether the different streams produced as output by the study case plant could be classified as SRF. For this reason, a sampling and analysis campaign was carried out with the purpose of characterizing every single output stream that can be obtained from the study case mechanical treatment plant, when operating it in different ways. The results showed that all the output flows from the study case mechanical treatment plant were classified as SRF, although with a wide quality range. In particular, few streams, of rather poor quality, could be fed to waste-to-energy plants, compatibly with the plant feeding systems. Other streams, with very high quality, were suitable for non-dedicated facilities, such as cement plants or power plants, as a substitute for coal. The implementation of the new legislation has hence the potential for a significant reduction of landfilling, contributing to lowering the overall environmental impact by avoiding the direct impacts of landfilling and by exploiting the beneficial

  7. Sodium Loop Safety Facility W-2 experiment fuel pin rupture detection system. [LMFBR

    Energy Technology Data Exchange (ETDEWEB)

    Hoffman, M.A.; Kirchner, T.L.; Meyers, S.C.

    1980-05-01

    The objective of the Sodium Loop Safety Facility (SLSF) W-2 experiment is to characterize the combined effects of a preconditioned full-length fuel column and slow transient overpower (TOP) conditions on breeder reactor (BR) fuel pin cladding failures. The W-2 experiment will meet this objective by providing data in two technological areas: (1) time and location of cladding failure, and (2) early post-failure test fuel behavior. The test involves a seven pin, prototypic full-length fast test reactor (FTR) fuel pin bundle which will be subjected to a simulated unprotected 5 cents/s reactivity transient overpower event. The outer six pins will provide the necessary prototypic thermal-hydraulic environment for the center pin.

  8. Alcohols/Ethers as Oxygenates in Diesel Fuel: Properties of Blended Fuels and Evaluation of Practiacl Experiences

    Energy Technology Data Exchange (ETDEWEB)

    Nylund, N.; Aakko, P. [TEC Trans Energy Consulting Ltd (Finland); Niemi, S.; Paanu, T. [Turku Polytechnic (Finland); Berg, R. [Befri Konsult (Sweden)

    2005-03-15

    Oxygenates blended into diesel fuel can serve at least two purposes. Components based on renewable feedstocks make it possible to introduce a renewable component into diesel fuel. Secondly, oxygenates blended into diesel fuel might help to reduce emissions. A number of different oxygenates have been considered as components for diesel fuel. These oxygenates include various alcohols, ethers, esters and carbonates. Of the oxygenates, ethanol is the most common and almost all practical experiences have been generated from the use of diesel/ethanol blends (E-diesel). Biodiesel was not included in this study. Adding ethanol to diesel will reduce cetane, and therefore, both cetane improver and lubricity additives might be needed. Diesel/ethanol emulsions obtained with emulsifiers or without additives are 'milky' mixtures. Micro-emulsions of ethanol and diesel can be obtained using additives containing surfactants or co-solvents. The microemulsions are chemically and thermodynamically stable, they are clear and bright blends, unlike the emulsions. Storage and handling regulations for fuels are based on the flash point. The problem with, e.g., ethanol into diesel is that ethanol lowers the flash point of the blend significantly even at low concentrations. Regarding safety, diesel-ethanol blends fall into the same category as gasoline. Higher alcohols are more suitable for diesel blending than ethanol. Currently, various standards and specifications set rather tight limits for diesel fuel composition and properties. It should be noted that, e.g., E-diesel does not fulfil any current diesel specification and it cannot, thus, be sold as general diesel fuel. Some blends have already received approvals for special applications. The critical factors of the potential commercial use of these blends include blend properties such as stability, viscosity and lubricity, safety and materials compatibility. The effect of the fuel on engine performance, durability and emissions

  9. Multidimensional shielding analysis of the JASPER in-vessel fuel storage experiments

    Energy Technology Data Exchange (ETDEWEB)

    Bucholz, J.A.

    1993-03-01

    The In-Vessel Fuel Storage (IVFS) experiments analyzed in this report were conducted at the Oak Ridge National Laboratory`s Tower Shielding Reactor (TSR) as part of the Japanese-American Shielding Program for Experimental Research (JASPER). These IVFS experiments were designed to study source multiplication and three-dimensional effects related to in-vessel storage of spent fuel elements in liquid metal reactor (LMR) systems. The present report describes the 2-D and 3-D models, analyses, and calculated results corresponding to a limited subset of those IVFS experiments in which the US LMR program has a particular interest.

  10. Fuel Fabrication Capability WBS 01.02.01.05 - HIP Bonding Experiments Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Dickerson, Patricia O' Donnell [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Summa, Deborah Ann [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Liu, Cheng [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Tucker, Laura Arias [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Chen, Ching-Fong [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Aikin, Beverly [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Aragon, Daniel Adrian [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Beard, Timothy Vance [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Montalvo, Joel Dwayne [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Pena, Maria Isela [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Dombrowski, David E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-06-10

    The goals of this project were to demonstrate reliable, reproducible solid state bonding of aluminum 6061 alloy plates together to encapsulate DU-10 wt% Mo surrogate fuel foils. This was done as part of the CONVERT Fuel Fabrication Capability effort in Process Baseline Development . Bonding was done using Hot Isotatic Pressing (HIP) of evacuated stainless steel cans (a.k.a HIP cans) containing fuel plate components and strongbacks. Gross macroscopic measurements of HIP cans prior to HIP and after HIP were used as part of this demonstration, and were used to determine the accuracy of a finitie element model of the HIP bonding process. The quality of the bonding was measured by controlled miniature bulge testing for Al-Al, Al-Zr, and Zr-DU bonds. A special objective was to determine if the HIP process consistently produces good quality bonding and to determine the best characterization techniques for technology transfer.

  11. Large scale experiments simulating hydrogen distribution in a spent fuel pool building during a hypothetical fuel uncovery accident scenario

    Energy Technology Data Exchange (ETDEWEB)

    Mignot, Guillaume; Paranjape, Sidharth; Paladino, Domenico; Jaeckel, Bernd; Rydl, Adolf [Paul Scherrer Institute, Villigen (Switzerland)

    2016-08-15

    Following the Fukushima accident and its extended station blackout, attention was brought to the importance of the spent fuel pools' (SFPs) behavior in case of a prolonged loss of the cooling system. Since then, many analytical works have been performed to estimate the timing of hypothetical fuel uncovery for various SFP types. Experimentally, however, little was done to investigate issues related to the formation of a flammable gas mixture, distribution, and stratification in the SFP building itself and to some extent assess the capability for the code to correctly predict it. This paper presents the main outcomes of the Experiments on Spent Fuel Pool (ESFP) project carried out under the auspices of Swissnuclear (Framework 2012–2013) in the PANDA facility at the Paul Scherrer Institut in Switzerland. It consists of an experimental investigation focused on hydrogen concentration build-up into a SFP building during a predefined scaled scenario for different venting positions. Tests follow a two-phase scenario. Initially steam is released to mimic the boiling of the pool followed by a helium/steam mixture release to simulate the deterioration of the oxidizing spent fuel. Results shows that while the SFP building would mainly be inerted by the presence of a high concentration of steam, the volume located below the level of the pool in adjacent rooms would maintain a high air content. The interface of the two-gas mixture presents the highest risk of flammability. Additionally, it was observed that the gas mixture could become stagnant leading locally to high hydrogen concentration while steam condenses. Overall, the experiments provide relevant information for the potentially hazardous gas distribution formed in the SFP building and hints on accident management and on eventual retrofitting measures to be implemented in the SFP building.

  12. QUICK ASSESSMENT METHODOLOGY FOR RELIABILITY OF SOLDER JOINTS IN BALL GRID ARRAY (BGA)ASSEMBLY--PART Ⅱ: RELIABILITY EXPERIMENT AND NUMERICAL SIMULATION

    Institute of Scientific and Technical Information of China (English)

    史训清; John HL Pang; 杨前进; 王志平; 聂景旭

    2002-01-01

    In the present study, a facility, i.e., a mechanical deflection system(MDS), was established and applied to assess the long-term reliability of the solder joints in plastic ball grid array (BGA) assembly. It was found that the MDS not only quickly assesses the long-term reliability of solder joints within days, but can also mimic similar failure mechanisms in accelerated thermal cycling (ATC) tests.Based on the MDS and ATC reliability experiments, the acceleration factors (AF)were obtained for different reliability testing conditions. Furthermore, by using the creep constitutive relation and fatigue life model developed in part I, a numerical approach was established for the purpose of virtual life prediction of solder joints.The simulation results were found to be in good agreement with the test results from the MDS. As a result, a new reliability assessment methodology was established as an alternative to ATC for the evaluation of long-term reliability of plastic BGA assembly.

  13. Clean, Efficient, and Reliable Heat and Power for the 21st Century, Fuel Cell Technologies Program (FCTP) (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    2010-05-01

    This overview of the U.S. Department of Energy's Fuel Cell Technologies Program describes the program's focus and goals, along with current fuel cell applications and future potential. The program focuses on research and development of fuel cell systems for diverse applications in the stationary power, portable power, and transportation sectors. It works to reduce costs and improve technologies to advance fuel cell uses in areas such as combined heat and power, auxiliary power units, portable power systems, and stationary and backup power. To help ensure that fuel cell advances are realized, the program rigorously analyzes energy efficiency, economic, and environmental benefits of fuel cells and seeks to optimize synergies among fuel cell applications and other renewable technologies.

  14. Reliability Lessons Learned From GPU Experience With The Titan Supercomputer at Oak Ridge Leadership Computing Facility

    Energy Technology Data Exchange (ETDEWEB)

    Gallarno, George [Christian Brothers University; Rogers, James H [ORNL; Maxwell, Don E [ORNL

    2015-01-01

    The high computational capability of graphics processing units (GPUs) is enabling and driving the scientific discovery process at large-scale. The world s second fastest supercomputer for open science, Titan, has more than 18,000 GPUs that computational scientists use to perform scientific simu- lations and data analysis. Understanding of GPU reliability characteristics, however, is still in its nascent stage since GPUs have only recently been deployed at large-scale. This paper presents a detailed study of GPU errors and their impact on system operations and applications, describing experiences with the 18,688 GPUs on the Titan supercom- puter as well as lessons learned in the process of efficient operation of GPUs at scale. These experiences are helpful to HPC sites which already have large-scale GPU clusters or plan to deploy GPUs in the future.

  15. Critical experiments supporting close proximity water storage of power reactor fuel. Technical progress report, October 1, 1977-December 31, 1977

    Energy Technology Data Exchange (ETDEWEB)

    Baldwin, M.N.; Hoovler, G.S.

    1978-03-01

    Experiments are being conducted on critical configurations of clusters of fuel rods, mocking up LWR-type fuel elements in close proximity water storage. Spacings between fuel clusters and the intervening material are being varied to provide a variety of benchmark loadings. (DLC)

  16. REVIEW OF FAST FLUX TEST FACILITY (FFTF) FUEL EXPERIMENTS FOR STORAGE IN INTERIM STORAGE CASKS (ISC)

    Energy Technology Data Exchange (ETDEWEB)

    CHASTAIN, S.A.

    2005-10-24

    Appendix H, Section H.3.3.10.11 of the Final Safety Analysis Report (FSAR), provides the limits to be observed for fueled components authorized for storage in the Fast Flux Test Facility (FFTF) spent fuel storage system. Currently, the authorization basis allows standard driver fuel assemblies (DFA), as described in the FSAR Chapter 17, Section 17.5.3.1, to be stored provided decay power per assembly is {le} 250 watts, post-irradiation time is four years minimum, average assembly burn-up is 150,000 MWD/MTHM maximum and the pre-irradiation enrichment is 29.3% maximum (per H.3.3.10.11). In addition, driver evaluation (DE), core characterizer assemblies (CCA), and run-to-cladding-breach (RTCB) assemblies are included based on their similarities to a standard DFA. Ident-69 pin containers with fuel pins from these DFAs can also be stored. Section H.3.3.10.11 states that fuel types outside the specification criteria above will be addressed on a case-by-case basis. There are many different types of fuel and blanket experiments that were irradiated in the FFTF which now require offload to the spent fuel storage system. Two reviews were completed for a portion of these special type fuel components to determine if placement into the Core Component Container (CCC)/Interim Storage Cask (ISC) would require any special considerations or changes to the authorization basis. Project mission priorities coupled with availability of resources and analysts prevented these evaluations from being completed as a single effort. Areas of review have included radiological accident release consequences, radiological shielding adequacy, criticality safety, thermal limits, confinement, and stress. The results of these reviews are available in WHC-SD-FF-RPT-005, Rev. 0 and 1, ''Review of FFTF Fuel Experiments for Storage at ISA'', (Reference I), which subsequently allowed a large portion of these components to be included in the authorization basis (Table H.3.3-21). The

  17. Measurements of nitrous acid in commercial aircraft exhaust at the Alternative Aviation Fuel Experiment.

    Science.gov (United States)

    Lee, Ben H; Santoni, Gregory W; Wood, Ezra C; Herndon, Scott C; Miake-Lye, Richard C; Zahniser, Mark S; Wofsy, Steven C; Munger, J William

    2011-09-15

    The Alternative Aviation Fuel Experiment (AAFEX), conducted in January of 2009 in Palmdale, California, quantified aerosol and gaseous emissions from a DC-8 aircraft equipped with CFM56-2C1 engines using both traditional and synthetic fuels. This study examines the emissions of nitrous acid (HONO) and nitrogen oxides (NO(x) = NO + NO(2)) measured 145 m behind the grounded aircraft. The fuel-based emission index (EI) for HONO increases approximately 6-fold from idle to takeoff conditions but plateaus between 65 and 100% of maximum rated engine thrust, while the EI for NO(x) increases continuously. At high engine power, NO(x) EI is greater when combusting traditional (JP-8) rather than Fischer-Tropsch fuels, while HONO exhibits the opposite trend. Additionally, hydrogen peroxide (H(2)O(2)) was identified in exhaust plumes emitted only during engine idle. Chemical reactions responsible for emissions and comparison to previous measurement studies are discussed.

  18. Inter-rater reliability in the classification of supraspinatus tendon tears using 3D ultrasound – a question of experience?

    Directory of Open Access Journals (Sweden)

    Giorgio Tamborrini

    2016-09-01

    Full Text Available Background: Three-dimensional (3D ultrasound of the shoulder is characterized by a comparable accuracy to two-dimensional (2D ultrasound. No studies investigating 2D versus 3D inter-rater reliability in the detection of supraspinatus tendon tears taking into account the level of experience of the raters have been carried out so far. Objectives: The aim of this study was to determine the inter-rater reliability in the analysis of 3D ultrasound image sets of the supraspinatus tendon between sonographer with different levels of experience. Patients and methods: Non-interventional, prospective, observational pilot study of 2309 images of 127 adult patients suffering from unilateral shoulder pain. 3D ultrasound image sets were scored by three raters independently. The intra-and interrater reliabilities were calculated. Results: There was an excellent intra-rater reliability of rater A in the overall classification of supraspinatus tendon tears (2D vs 3D κ = 0.892, pairwise reliability 93.81%, 3D scoring round 1 vs 3D scoring round 2 κ = 0.875, pairwise reliability 92.857%. The inter-rater reliability was only moderate compared to rater B on 3D (κ = 0.497, pairwise reliability 70.95% and fair compared to rater C (κ = 0.238, pairwise reliability 42.38%. Conclusions: The reliability of 3D ultrasound of the supraspinatus tendon depends on the level of experience of the sonographer. Experience in 2D ultrasound does not seem to be sufficient for the analysis of 3D ultrasound imaging sets. Therefore, for a 3D ultrasound analysis new diagnostic criteria have to be established and taught even to experienced 2D sonographers to improve reproducibility.

  19. Large Scale Experiments Simulating Hydrogen Distribution in a Spent Fuel Pool Building During a Hypothetical Fuel Uncovery Accident Scenario

    Directory of Open Access Journals (Sweden)

    Guillaume Mignot

    2016-08-01

    This paper presents the main outcomes of the Experiments on Spent Fuel Pool (ESFP project carried out under the auspices of Swissnuclear (Framework 2012–2013 in the PANDA facility at the Paul Scherrer Institut in Switzerland. It consists of an experimental investigation focused on hydrogen concentration build-up into a SFP building during a predefined scaled scenario for different venting positions. Tests follow a two-phase scenario. Initially steam is released to mimic the boiling of the pool followed by a helium/steam mixture release to simulate the deterioration of the oxidizing spent fuel. Results shows that while the SFP building would mainly be inerted by the presence of a high concentration of steam, the volume located below the level of the pool in adjacent rooms would maintain a high air content. The interface of the two-gas mixture presents the highest risk of flammability. Additionally, it was observed that the gas mixture could become stagnant leading locally to high hydrogen concentration while steam condenses. Overall, the experiments provide relevant information for the potentially hazardous gas distribution formed in the SFP building and hints on accident management and on eventual retrofitting measures to be implemented in the SFP building.

  20. Precisely determined the spent nuclear fuel antineutrino flux and spectrum for Daya Bay antineutrino experiment

    CERN Document Server

    Ma, X B; Chen, Y X; Zhong, W L; An, F P

    2015-01-01

    Spent nuclear fuel (SNF) antineutrino flux is an important source of uncertainties for a reactor neutrino flux prediction. However, if one want to determine the contribution of spent fuel, many data are needed, such as the amount of spent fuel in the pool, the time after discharged from the reactor core, the burnup of each assembly, and the antineutrino spectrum of the isotopes in the spend fuel. A method to calculate the contribution of SNF is proposed in this study. In this method, reactor simulation code verified by experiment have been used to simulate the fuel depletion by taking into account more than 2000 isotopes and fission products, the quantity of SNF in each six spend fuel pool, and the antineutrino spectrum of SNF varying with time after SNF discharged from core. Results show that the contribution of SNF to the total antineutrino flux is about 0.26%~0.34%, and the shutdown impact is about 20%. The SNF spectrum would distort the softer part of antineutrino spectra, and the maximum contribution fro...

  1. Investigation of Acquired Fuel Motion Caused by Ice Roughness in OMEGA Cryogenic Experiments

    Science.gov (United States)

    Cao, D.; McKenty, P. W.; Knauer, J. P.

    2016-10-01

    It is expected that DT ice/gas interfaces in cryogenic targets will have a certain level of ice roughness; however, less is known about the possible influence of this roughness on net fuel motion during a target implosion. Measureable nonzero net fuel velocity is typically associated with low- l mode asymmetries. Since ice roughness is mainly characterized by low l modes, this work examines the effect of roughness on fuel motion in OMEGA cryogenic experiments. The measurements of fuel motion are taken using neutron time-of-flight (nTOF) diagnostics, which operate on the principle that emitted neutrons have an additional velocity component caused by the fluid motion from which they are borne. This gives rise to an energy shift of the neutron energy spectra. NTOF measurements will be shown illustrating the overall fuel motion that is systematically seen in OMEGA cryogenic implosions but not seen in warm target implosions. Results from 2-D DRACO simulations, which include low l-mode ice roughness, will be presented and the predicted acquired fuel motion will be compared to experimental data. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

  2. Parametric analysis of the proton exchange membrane fuel cell performance using design of experiments

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Wei-Lung [School of Defense Science, Chung Cheng Institute of Technology, National Defense University, No. 190, Sanyuan 1st Street, Ta-Hsi, Taoyuan, Taiwan 335 (China); Wu, Sheng-Ju; Shiah, Sheau-Wen [Department of Power Vehicle and Systems Engineering, Chung Cheng Institute of Technology, National Defense University, No. 190, Sanyuan 1st Street, Ta-Hsi, Taoyuan, Taiwan 335 (China)

    2008-05-15

    Proton exchange membrane fuel cell (PEMFC) performance depends on different fuel cell operating temperatures, humidification temperatures, operating pressures, flow rates, and various combinations of these parameters. This study employed the method of the design of experiments (DOE) to obtain the optimal combination of the six primary operating parameters (fuel cell operating temperatures, operating pressures, anode and cathode humidification temperatures, anode and cathode stoichiometric flow ratios). In the first stage, this study adopted a 2{sup k-2} fractional factorial design of the DOE to determine whether these factors have significant effects on a response and the interactions between various parameters. Second, the L{sub 27}(3{sup 13}) orthogonal array of the Taguchi method is utilized to determine the optimal combination of factors for a fuel cell. Based on this study, the operating pressure, the operating temperature, and the interactions between operating temperature and operating pressure have a significant effect on the fuel cell performance. Among them, the operating pressure is the most important contributor. When the operating pressure increases, it should simultaneously lower the effects of other factors. While both the operating temperature and pressure increase simultaneously with that, the other factors are at appropriate conditions, it is possible to improve the fuel cell performance. (author)

  3. Summary report on the fuel performance modeling of the AFC-2A, 2B irradiation experiments

    Energy Technology Data Exchange (ETDEWEB)

    Pavel G. Medvedev

    2013-09-01

    The primary objective of this work at the Idaho National Laboratory (INL) is to determine the fuel and cladding temperature history during irradiation of the AFC-2A, 2B transmutation metallic fuel alloy irradiation experiments containing transuranic and rare earth elements. Addition of the rare earth elements intends to simulate potential fission product carry-over from pyro-metallurgical reprocessing. Post irradiation examination of the AFC-2A, 2B rodlets revealed breaches in the rodlets and fuel melting which was attributed to the release of the fission gas into the helium gap between the rodlet cladding and the capsule which houses six individually encapsulated rodlets. This release is not anticipated during nominal operation of the AFC irradiation vehicle that features a double encapsulated design in which sodium bonded metallic fuel is separated from the ATR coolant by the cladding and the capsule walls. The modeling effort is focused on assessing effects of this unanticipated event on the fuel and cladding temperature with an objective to compare calculated results with the temperature limits of the fuel and the cladding.

  4. Experiences from Swedish demonstration projects with phosphoric acid fuel cells; Erfarenheter fraan svenska demonstrationsprojekt med fosforsyrabraensleceller

    Energy Technology Data Exchange (ETDEWEB)

    Carlsson, Per [Sycon Energikonsult AB, Stockholm (Sweden); Sarkoezi, Laszlo [Vattenfall Utveckling AB, Stockholm (Sweden)

    1999-10-01

    In Sweden, there are today two phosphoric acid fuel cells installed, one PC25A which have been in operation in more than 4 years, and one PC25C which have been in operation for two years. The aim with this project has been two compare operation characteristics, performance, and operation experiences for these two models.

  5. Quantitative Investigations of Biodiesel Fuel Using Infrared Spectroscopy: An Instrumental Analysis Experiment for Undergraduate Chemistry Students

    Science.gov (United States)

    Ault, Andrew P.; Pomeroy, Robert

    2012-01-01

    Biodiesel has gained attention in recent years as a renewable fuel source due to its reduced greenhouse gas and particulate emissions, and it can be produced within the United States. A laboratory experiment designed for students in an upper-division undergraduate laboratory is described to study biodiesel production and biodiesel mixing with…

  6. Analysis of sample and fuel pin irradiation experiments in Phenix for basic nuclear data validation

    Energy Technology Data Exchange (ETDEWEB)

    D' Angelo, A.; Cleri, F. (ENEA, Casaccia Nuclear Research Centre, Dipartimento Reattori Veloci, 0060 Casaccia (IT)); Marimbeau, P.; Salvatores, M.; Grouiller, J.P. (Centre d' Etudes Nucleaires de Cadarache, Service de Physique des Reacteurs et du Cycle, Dept. de Recherche Physique, 13108 St. Paul-lez-Durance (FR))

    1990-07-01

    This paper presents comparisons between calculations and experimental data from fuel irradiation experiments performed in Phenix. Both the French CARNAVAL-IV system and the recently developed JEF-1 basic data file are used. The global consistency of the results is excellent and the compared values are, in general, very satisfactory. In some cases, indications for evaluated data modifications are obtained.

  7. Quantitative Investigations of Biodiesel Fuel Using Infrared Spectroscopy: An Instrumental Analysis Experiment for Undergraduate Chemistry Students

    Science.gov (United States)

    Ault, Andrew P.; Pomeroy, Robert

    2012-01-01

    Biodiesel has gained attention in recent years as a renewable fuel source due to its reduced greenhouse gas and particulate emissions, and it can be produced within the United States. A laboratory experiment designed for students in an upper-division undergraduate laboratory is described to study biodiesel production and biodiesel mixing with…

  8. Experiment on the improvement of OREOX process for fabrication of dry recycling nuclear fuel pellets

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Woong Ki; Kim, S. S.; Park, G. I. [and others

    2004-01-01

    The OREOX(Oxidation and REduction of OXide fuel) process has been performed to fabricate dry recycling(DUPIC ; Direct Use of spent PWR fuel In CANDU reactor) nuclear fuel pellets by using spent PWR fuel. Generally, sinterable DUPIC powder has been manufactured from spent PWR fuel pellets by the 3 cycles of oxidation and reduction treatment. The OREOX process is one of the most important processes for DUPIC pellet fabrication. A lot of time more than 37 hours as well as a lot of reaction gas is required to perform 3 cycles of OREOX treatments. In this experiment, 1 cycle OREOX process was adopted to improve the powdering process of DUPIC pellet manufacturing processes. As a result of experiment, the densities of pellets sintered at 1800 .deg. C for 10 hours ranged from 10.15 to 10.22 g/cm{sup 3}(93.8{approx}94.5 % of T.D.). The pellets were sintered again to increase the sintered density. The sintered densities of pellets re-sintered at 1850 .deg. C for 7 hours ranged from 10.27 to 10.33 g/cm{sup 3}(94.9{approx} 95.5 % of T.D)

  9. 固体燃料超燃冲压发动机原理性试验研究%Experiment study on the principle of solid fuel scramjet

    Institute of Scientific and Technical Information of China (English)

    杨向明; 刘伟凯; 陈林泉; 郑凯斌

    2012-01-01

    进行了固体燃料超燃冲压发动机实验研究,并成功进行了点火和燃烧实验,包括固体碳氢燃料超音速燃烧试验和聚甲基丙烯酸甲酯(PMMA)超音速燃烧试验.实验验证了固体燃料在超音速气流中能可靠点火,并保持了火焰的稳定燃烧,获得了固体燃料的超音速燃烧内弹道特性,同时研究了固体燃料PMMA在超音速气流中的燃烧,分析了其在超燃冲压燃烧室内的退移规律,认为燃料退移速度随时间变化,燃烧趋向于将燃面轮廓变平,区域显示圆柱形.%Solid fuel scramjet was investigated by experiment. Ignition and combustion experiments that include solid hydrocarbon fuel and PMMA fuel were successfully done,which proved reliable ignition of the solid fuel in supersonic flow and stable combustion of the flame. Finally supersonic chamber characteristics of solid fuel were obtained. Combustion of PMMA fuel in supersonic flow was also investigated,and its regression rule was analyzed. Results show that regression rate of PMMA fuel changes with time, combustion outline tends to be plane and combustion region exhibits column.

  10. Progress of the RIA experiments with high burnup fuels and their evaluation in JAERI

    Energy Technology Data Exchange (ETDEWEB)

    Ishijima, Kiyomi; Fuketa, Toyoshi [Japan Atomic Energy Research Institute, Ibaraki-ken (Japan)

    1997-01-01

    Recent results obtained in the NSRR power burst experiments with high burnup PWR fuel rods are described and discussed in this paper. Data concerning test condition, transient records during pulse irradiation and post irradiation examination are described. Another high burnup PWR fuel rod failed in the test HBO-5 at the slightly higher energy deposition than that in the test HBO-1. The failure mechanism of the test HBO-5 is the same as that of the test HBO-1, that is, hydride-assisted PCMI. Some influence of the thermocouples welding on the failure behavior of the HBO-5 rod was observed.

  11. NASA Alternative-Fuel Effects on Contrails and Cruise Emissions (ACCESS) Flight Experiments

    Science.gov (United States)

    Anderson, B. E.; Moore, R.; Beyersdorf, A. J.; Thornhill, K. L., II; Shook, M.; Winstead, E.; Ziemba, L. D.; Bulzan, D. L.; Brown, A.; Beaton, B.; Schlager, H.

    2014-12-01

    Although the emission performance of gas-turbine engines burning renewable aviation fuels have been thoroughly documented in recent ground-based studies, there is still great uncertainty regarding how the fuels effect aircraft exhaust composition and contrail formation at cruise altitudes. To fill this information gap, the NASA Aeronautics Research Mission Directorate sponsored the ACCESS flight series to make detailed measurements of trace gases, aerosols and ice particles in the near-field behind the NASA DC-8 aircraft as it burned either standard petroleum-based fuel of varying sulfur content or a 50:50 blend of standard fuel and a hydro-treated esters and fatty acid (HEFA) jet fuel produced from camelina plant oil. ACCESS 1, conducted in spring 2013 near Palmdale CA, focused on refining flight plans and sampling techniques and used the instrumented NASA Langley HU-25 aircraft to document DC-8 emissions and contrails on five separate flights of ~2 hour duration. ACCESS 2, conducted from Palmdale in May 2014, engaged partners from the Deutsches Zentrum für Luft- und Raumfahrt (DLR) and National Research Council-Canada to provide additional scientific expertise and sampling aircraft (Falcon 20 and CT-133, respectively) with more extensive trace gas, particle, or air motion measurement capability. Eight, muliti-aircraft research flights of 2 to 4 hour duration were conducted to document the emissions and contrail properties of the DC-8 as it 1) burned low sulfur Jet A, high sulfur Jet A or low sulfur Jet A/HEFA blend, 2) flew at altitudes between 6 and 11 km, and 3) operated its engines at three different fuel flow rates. This presentation further describes the ACCESS flight experiments, examines fuel type and thrust setting impacts on engine emissions, and compares cruise-altitude observations with similar data acquired in ground-test venues.

  12. The statistical analysis techniques to support the NGNP fuel performance experiments

    Science.gov (United States)

    Pham, Binh T.; Einerson, Jeffrey J.

    2013-10-01

    This paper describes the development and application of statistical analysis techniques to support the Advanced Gas Reactor (AGR) experimental program on Next Generation Nuclear Plant (NGNP) fuel performance. The experiments conducted in the Idaho National Laboratory's Advanced Test Reactor employ fuel compacts placed in a graphite cylinder shrouded by a steel capsule. The tests are instrumented with thermocouples embedded in graphite blocks and the target quantity (fuel temperature) is regulated by the He-Ne gas mixture that fills the gap volume. Three techniques for statistical analysis, namely control charting, correlation analysis, and regression analysis, are implemented in the NGNP Data Management and Analysis System for automated processing and qualification of the AGR measured data. The neutronic and thermal code simulation results are used for comparative scrutiny. The ultimate objective of this work includes (a) a multi-faceted system for data monitoring and data accuracy testing, (b) identification of possible modes of diagnostics deterioration and changes in experimental conditions, (c) qualification of data for use in code validation, and (d) identification and use of data trends to support effective control of test conditions with respect to the test target. Analysis results and examples given in the paper show the three statistical analysis techniques providing a complementary capability to warn of thermocouple failures. It also suggests that the regression analysis models relating calculated fuel temperatures and thermocouple readings can enable online regulation of experimental parameters (i.e. gas mixture content), to effectively maintain the fuel temperature within a given range.

  13. Determination of fission gas release of spent nuclear fuel in puncturing test and in leaching experiments under anoxic conditions

    Science.gov (United States)

    González-Robles, E.; Metz, V.; Wegen, D. H.; Herm, M.; Papaioannou, D.; Bohnert, E.; Gretter, R.; Müller, N.; Nasyrow, R.; de Weerd, W.; Wiss, T.; Kienzler, B.

    2016-10-01

    During reactor operation the fission gases Kr and Xe are formed within the UO2 matrix of nuclear fuel. Their quantification is important to evaluate their impact on critical parameters regarding the fuel behaviour during irradiation and (long-term) interim storage, such as internal pressure of the fuel rod and fuel swelling. Moreover the content of Kr and Xe in the plenum of a fuel rod and their content in the UO2 fuel itself are widely used as indicators for the release properties of 129I, 137Cs, and other safety relevant radionuclides with respect to final disposal of spent nuclear fuel. The present study deals with the fission gas release from spent nuclear fuel exposed to simulated groundwater in comparison with the fission gas previously released to the fuel rod plenum during irradiation in reactor. In a unique approach we determined both the Kr and Xe inventories in the plenum by means of a puncturing test and in leaching experiments with a cladded fuel pellet and fuel fragments in bicarbonate water under 3.2 bar H2 overpressure. The fractional inventory of the fission gases released during irradiation into the plenum was (8.3 ± 0.9) %. The fraction of inventory of fission gases released during the leaching experiments was (17 ± 2) % after 333 days of leaching of the cladded pellet and (25 ± 2) % after 447 days of leaching of the fuel fragments, respectively. The relatively high release of fission gases in the experiment with fuel fragments was caused by the increased accessibility of water to the Kr and Xe occluded in the fuel.

  14. Pre-qualification experiments of DUPIC fuel pellets for irradiation testing in the NRU reactor

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Woong Ki; Kim, S. S.; Lee, J. W. and others

    2002-02-01

    DUPIC fuel manufacturing technologies and processes have been developed at DFDF(DUPIC Fuel Development Facility, IMEF M6). Using DUPIC powder prepared by the oxidation and reduction processes, the DUPIC fuel pellets and mini-elements were fabricated for the irradiation test and performance evaluation at HANARO. In this study, the irradiation test was planned for the performance evaluation of DUPIC fuel pellets and elements at NRU. To establish fabrication process satisfying the requirements of NRU irradiation test, sintered DUPIC pellets were fabricated with a variety of process parameters involving compaction pressure and characterized by the inspection system. As a result of the experiment, DUPIC pellets with 12.19 mm of diameter, 10.37{approx}10.45 g/cm{sup 3} of sintered density, and less than Ra 0.8{mu}m of surface roughness have been successfully fabricated at hot cell. The optimum DUPIC pellet fabrication process satisfying the requirements of NRU irradiation has been established based on the result of this experiment.

  15. Ceramography of Irradiated tristructural isotropic (TRISO) Fuel from the AGR-2 Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Rice, Francine Joyce [Idaho National Lab. (INL), Idaho Falls, ID (United States); Stempien, John Dennis [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-09-01

    Ceramography was performed on cross sections from four tristructural isotropic (TRISO) coated particle fuel compacts taken from the AGR-2 experiment, which was irradiated between June 2010 and October 2013 in the Advanced Test Reactor (ATR). The fuel compacts examined in this study contained TRISO-coated particles with either uranium oxide (UO2) kernels or uranium oxide/uranium carbide (UCO) kernels that were irradiated to final burnup values between 9.0 and 11.1% FIMA. These examinations are intended to explore kernel and coating morphology evolution during irradiation. This includes kernel porosity, swelling, and migration, and irradiation-induced coating fracture and separation. Variations in behavior within a specific cross section, which could be related to temperature or burnup gradients within the fuel compact, are also explored. The criteria for categorizing post-irradiation particle morphologies developed for AGR-1 ceramographic exams, was applied to the particles in the AGR-2 compacts particles examined. Results are compared with similar investigations performed as part of the earlier AGR-1 irradiation experiment. This paper presents the results of the AGR-2 examinations and discusses the key implications for fuel irradiation performance.

  16. Experiments and simulations of NOx formation in the combustion of hydroxylated fuels

    KAUST Repository

    Bohon, Myles

    2015-06-01

    This work investigates the influence of molecular structure in hydroxylated fuels (i.e. fuels with one or more hydroxyl groups), such as alcohols and polyols, on NOx formation. The fuels studied are three lower alcohols (methanol, ethanol, and n-propanol), two diols (1,2-ethanediol and 1,2-propanediol), and one triol (1,2,3-propanetriol); all of which are liquids at room temperature and span a wide range of thermophysical properties. Experimental stack emissions measurements of NO/NO2, CO, and CO2 and flame temperature profiles utilizing a rake of thermocouples were obtained in globally lean, swirling, liquid atomized spray flames inside a refractory-lined combustion chamber as a function of the atomizing air flow rate and swirl number. These experiments show significantly lower NOx formation with increasing fuel oxygen content despite similarities in the flame temperature profiles. By controlling the temperature profiles, the contribution to NOx formation through the thermal mechanism were matched, and variations in the contribution through non-thermal NOx formation pathways are observed. Simulations in a perfectly stirred reactor, at conditions representative of those measured within the combustion region, were conducted as a function of temperature and equivalence ratio. The simulations employed a detailed high temperature chemical kinetic model for NOx formation from hydroxylated fuels developed based on recent alcohol combustion models and extended to include polyol combustion chemistry. These simulations provide a qualitative comparison to the range of temperatures and equivalence ratios observed in complex swirling flows and provide insight into the influence of variations in the fuel decomposition pathways on NOx formation. It is observed that increasing the fuel bound oxygen concentration ultimately reduces the formation of NOx by increasing the proportion of fuel oxidized through formaldehyde, as opposed to acetylene or acetaldehyde

  17. Sintering of CaF 2 pellets as nuclear fuel analog for surface stability experiments

    Science.gov (United States)

    Godinho, José R. A.; Piazolo, Sandra; Stennett, Martin C.; Hyatt, Neil C.

    2011-12-01

    To enable a detailed study of the influence of microstructure and surface properties on the stability of spent nuclear fuel, it is necessary to produce analogs that closely resemble nuclear fuel in terms of crystallography and microstructure. One such analog can be obtained by sintering CaF 2 powder. This paper reports the microstructures obtained after sintering CaF 2 powders at temperatures up to 1240 °C. Pellets with microstructure, density and pore structure similar to that of UO 2 spent nuclear fuel pellets were obtained in the temperature range between 900 °C and 1000 °C. When CaF 2 was sintered above 1100 °C the formation of CaO at the grain boundaries caused the disintegration of the pellet due to hydration occurring after sintering. First results from a novel set-up of dissolution experiments show that changes in roughness, dissolution rate and etch pit shape of fluorite surfaces are strongly dependent on the crystallographic orientation of the expose surface. Consequently, the differences observed for each orientation will affect the overall dissolution rate and will lead to uncertainties in the estimation of dissolution rates of spent nuclear fuel.

  18. Determination of the Emissions from an Aircraft Auxiliary Power Unit (APU) during the Alternative Aviation Fuel Experiment (AAFEX)

    Science.gov (United States)

    The emissions from a Garrett-AiResearch (now Honeywell) Model GTCP85-98CK APU were determined as part of the National Aeronautics and Space Administration's (NASA's) Alternative Aviation Fuels Experiment using both JP-8 and a coal-derived Fischer Tropsch fuel (FT-2). Measurements...

  19. Migration and degradation of fuel vapours in the vadose zone. Field experiment at airbase Værløse

    DEFF Research Database (Denmark)

    Christophersen, Mette; Broholm, Mette Martina; Kjeldsen, Peter

    2002-01-01

    Fuel has been spilled in the vadose zone at many sites. An artificial jet fuel source has been installed in a vadose zone (3.5 m sand) at Airbase Værløse. The field experiment is conducted to investigate the natural attenuation potential in order to obtain better evaluations of the risk for ground...

  20. Influence of plutonium contents in MOX fuel on destructive forces at fuel failure in the NSRR experiment

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, Jinichi; Sugiyama, Tomoyuki; Nakamura, Takehiko; Kanazawa, Toru; Sasajima, Hideo [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2003-03-01

    In order to confirm safety margins of the Mixed Oxide (MOX) fuel use in LWRs, pulse irradiation tests are planned in the Nuclear Safety Research Reactor (NSRR) with the MOX fuel with plutonium content up to 12.8%. Impacts of the higher plutonium contents on safety of the reactivity-initiated-accident (RIA) tests are examined in terms of generation of destructive forces to threat the integrity of test capsules. Pressure pulses would be generated at fuel rod failure by releases of high pressure gases. The strength of the pressure pulses, therefore, depends on rod internal - external pressure difference, which is independent to plutonium content of the fuel. The other destructive forces, water hammer, would be generated by thermal interaction between fuel fragments and coolant water. Heat flux from the fragments to the water was calculated taking account of changes in thermal properties of MOX fuels at higher plutonium contents. The results showed that the heat transfer from the MOX fuel would be slightly smaller than that from UO{sub 2} fuel fragments at similar size in a short period to cause the water hammer. Therefore, the destructive forces were not expected to increase in the new tests with higher plutonium content MOX fuels. (author)

  1. Experiment on the improvement of sinterability for dry recycling nuclear fuel pellets by using simulated spent PWR fuel of high burnup

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Woong Ki; Kim, S. S.; Park, G. I.; Lee, Jae W.; Cho, K. H.; Lee, D. Y.; Lee, Y. S.; Lee, J. W.; Yang, M. S.; Shin, W. C

    2004-09-01

    To study the fabrication characteristics of dry recycling nuclear fuel using spent PWR fuel with high burnup of 60,000 MWd/tU, the fission products of spent PWR fuel was analyzed by ORIGEN-2 code. Simulated spent PWR fuel pellets were fabricated by using UO{sub 2} powder added by the simulated fission products. The simulated dry-recycling-fuel pellets were fabricated by dry recycling fuel fabrication flow including 3 cycle treated OREOX(Oxidation and REduction of OXide fuel) process. A small amount of dopant such as TiO{sub 2}, Nb{sub 2}O{sub 5}, Li{sub 2}O are added to increase sinterability of the OREOX treated powder. As the results of experiments, the densities of sintered pellets without dopant ranged from 10.04 to 10.34 g/cm{sup 3}(94.3 to 97.1% of T.D.), the grain size of the pellets ranged from 3 to 4 {mu}m. The sintered density of the pellets with TiO{sub 2} or Nb{sub 2}O{sub 5} ranged from 10.46 to 10.32 g/cm{sup 3}(98.2 to 96.9 % of T.D.) The grain size of the pellets with TiO{sub 2}, Nb{sub 2}O{sub 5} or Li{sub 2}O ranged from 7.3 to 12.2 {mu}m.

  2. Advanced air staging techniques to improve fuel flexibility, reliability and emissions in fluidized bed co-combustion

    Energy Technology Data Exchange (ETDEWEB)

    Aamand, Lars-Erik; Leckner, Bo [Chalmers Technical Univ., Goeteborg (Sweden); Luecke, Karsten; Werther, Joachim [Technical Univ. of Hamburg-Harburg (Germany)

    2001-12-01

    A joint research project between the Technical University of Hamburg-Harburg and Chalmers Technical University. For operation under co-combustion the following results should be considered: The high ash content of the sewage sludge results in significantly increased ash flows. Although high alkali metal concentrations are found in the sewage sludge ash, no critical concentrations were reached and tendencies to fouling were not observed. The trace metal input rises with increased sludge fraction. However, emissions of metal compounds were well below legal limits. The trace metals tend to accumulate on the fly ash. In general, very low fuel nitrogen conversions to NO and N{sub 2}O of 2 - 4 % are achievable. With coal as a base fuel alternative air staging with secondary air supply after solids separation attains even lower NO emissions than normal staging without strongly affecting CO and SO{sub 2} emissions. Alternative staging also reduces N{sub 2}O emissions. An optimum for the excess air ratio in the riser of 1.05 was found for a total excess air ratio of 1.2. The higher the volatile content of the fuel is, the less effective the NO reduction due to air staging becomes. The measurements suggest that the optimum gas residence time regarding the emissions in CFB combustors is around 6 to 7 s. These times are achieved in commercial scale plants due to their large cyclones that perhaps partly can replace a large afterburner chamber. The circulating fluidized bed boiler can be operated in a very flexible way with various fuel mixtures up to an energy fraction of sludge of 25% without exceeding legal emission limits.

  3. Measuring Educators' Attitudes and Beliefs about Evaluation: Construct Validity and Reliability of the Teacher Evaluation Experience Scale

    Science.gov (United States)

    Reddy, Linda A.; Dudek, Christopher M.; Kettler, Ryan J.; Kurz, Alexander; Peters, Stephanie

    2016-01-01

    This study presents the reliability and validity of the Teacher Evaluation Experience Scale--Teacher Form (TEES-T), a multidimensional measure of educators' attitudes and beliefs about teacher evaluation. Confirmatory factor analyses of data from 583 teachers were conducted on the TEES-T hypothesized five-factor model, as well as on alternative…

  4. Proceedings of the Water Reactor Fuel Performance Meeting - WRFPM / Top Fuel 2009

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-06-15

    SFEN, ENS, SNR, ANS, AESJ, CNS KNS, IAEA and NEA are jointly organizing the 2009 International Water Reactor Fuel Performance / TopFuel 2009 Meeting following the 2008 KNS Water Reactor Performance Meeting held during October 19-23, 2008 in Seoul, Korea. This meeting is held annually on a tri-annual rotational basis in Europe, USA and Asia. In 2009, this meeting will be held in Paris, September 6-10, 2009 in coordination with the Global 2009 Conference at the same date and place. That would lead to a common opening session, some common technical presentations, a common exhibition and common social events. The technical scope of the meeting includes all aspects of nuclear fuel from fuel rod to core design as well as manufacturing, performance in commercial and test reactors or on-going and future developments and trends. Emphasis will be placed on fuel reliability in the general context of nuclear 'Renaissance' and recycling perspective. The meeting includes selectively front and/or back end issues that impact fuel designs and performance. In this frame, the conference track devoted to 'Concepts for transportation and interim storage of spent fuels and conditioned waste' will be shared with 'GLOBAL' conference. Technical Tracks: - 1. Fuel Performance, Reliability and Operational Experience: Fuel operating experience and performance; experience with high burn-up fuels; water side corrosion; stress corrosion cracking; MOX fuel performance; post irradiation data on lead fuel assemblies; radiation effects; water chemistry and corrosion counter-measures. - 2. Transient Fuel Behaviour and Safety Related Issues: Transient fuel behavior and criteria (RIA, LOCA, ATWS, Ramp tests..). Fuel safety-related issues such as PCI (pellet cladding interaction), transient fission gas releases and cladding bursting/ballooning during transient events - Advances in fuel performance modeling and core reload methodology, small and large-scale fuel testing

  5. Analysis of Fresh Fuel Critical Experiments Appropriate for Burnup Credit Validation

    Energy Technology Data Exchange (ETDEWEB)

    DeHart, M.D.

    1995-01-01

    The ANS/ANS-8.1 standard requires that calculational methods used in determining criticality safety limits for applications outside reactors be validated by comparison with appropriate critical experiments. This report provides a detailed description of 34 fresh fuel critical experiments and their analyses using the SCALE-4.2 code system and the 27-group ENDF/B-IV cross-section library. The 34 critical experiments were selected based on geometry, material, and neutron interaction characteristics that are applicable to a transportation cask loaded with pressurized-water-reactor spent fuel. These 34 experiments are a representative subset of a much larger data base of low-enriched uranium and mixed-oxide critical experiments. A statistical approach is described and used to obtain an estimate of the bias and uncertainty in the calculational methods and to predict a confidence limit for a calculated neutron multiplication factor. The SCALE-4.2 results for a superset of approximately 100 criticals are included in uncertainty analyses, but descriptions of the individual criticals are not included.

  6. Analysis of fresh fuel critical experiments appropriate for burnup credit validation

    Energy Technology Data Exchange (ETDEWEB)

    DeHart, M.D.; Bowman, S.M.

    1995-10-01

    The ANS/ANS-8.1 standard requires that calculational methods used in determining criticality safety limits for applications outside reactors be validated by comparison with appropriate critical experiments. This report provides a detailed description of 34 fresh fuel critical experiments and their analyses using the SCALE-4.2 code system and the 27-group ENDF/B-IV cross-section library. The 34 critical experiments were selected based on geometry, material, and neutron interaction characteristics that are applicable to a transportation cask loaded with pressurized-water-reactor spent fuel. These 34 experiments are a representative subset of a much larger data base of low-enriched uranium and mixed-oxide critical experiments. A statistical approach is described and used to obtain an estimate of the bias and uncertainty in the calculational methods and to predict a confidence limit for a calculated neutron multiplication factor. The SCALE-4.2 results for a superset of approximately 100 criticals are included in uncertainty analyses, but descriptions of the individual criticals are not included.

  7. Reliability Allocation of Underwater Experiment System Based on Particle Swarm Optimization

    Directory of Open Access Journals (Sweden)

    Lu Xiong

    2013-06-01

    Full Text Available The problem of system reliability allocation is often solved by direct search method. The shortage, which affects the application of this method, is the large calculation amount of complex system architecture. Particle Swarm Optimization (PSO is a popular and bionic algorithm based on the social behavior associated with bird flocking for optimization problems. The particle swarm optimization, which attracted the interest of researchers. In this paper, a kind of PSO algorithm is proposed to solve underwater experimental system reliability problems. In addition, the reliability of the system model is established as well, the model is numerically simulated by PSO algorithm and examples are provided. The results show that compared to other algorithms, PSO has a better adaptability and can solve the optimal solution more stably without the precocious weakness, which is more suitable for reliability optimization of a system underwater with a more complex structure.

  8. Used Fuel Logistics: Decades of Experience with transportation and Interim storage solutions

    Energy Technology Data Exchange (ETDEWEB)

    Orban, G.; Shelton, C.

    2015-07-01

    Used fuel inventories are growing worldwide. While some countries have opted for a closed cycle with recycling, numerous countries must expand their interim storage solutions as implementation of permanent repositories is taking more time than foreseen. In both cases transportation capabilities will have to be developed. AREVA TN has an unparalleled expertise with transportation of used fuel. For more than 50 years AREVA TN has safely shipped more than 7,000 used fuel transport casks. The transportation model that was initially developed in the 1970s has been adapted and enhanced over the years to meet more restrictive regulatory requirements and evolving customer needs, and to address public concerns. The numerous “lessons learned” have offered data and guidance that have allowed for also efficient and consistent improvement over the decades. AREVA TN has also an extensive experience with interim dry storage solutions in many countries on-site but also is working with partners to developed consolidated interim storage facility. Both expertise with storage and transportation contribute to safe, secure and smooth continuity of the operations. This paper will describe decades of experience with a very successful transportation program as well as interim storage solutions. (Author)

  9. Impact of experience on government policy toward acceptance of hydrogen fuel cell vehicles in Korea

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Min Jung [Department of Information and Industrial Engineering, Yonsei University, 134 Shinchon-Dong, Seodaemoon-Gu, Seoul 120-749 (Korea, Republic of); Park, Heejun, E-mail: h.park@yonsei.ac.kr [Department of Information and Industrial Engineering, Yonsei University, 134 Shinchon-Dong, Seodaemoon-Gu, Seoul 120-749 (Korea, Republic of)

    2011-06-15

    As the 'low carbon, green growth' agenda, which emphasized sustainable development through equilibrium between economic growth and environmental preservation, is propagated rapidly in Korea. Despite this progress, it is not uncommon for new products made through advanced technologies, such as hydrogen fuel cell vehicles, to face public skepticism preventing market penetration. Therefore, the factors impacting customer acceptance of hydrogen fuel cell vehicles have to be estimated. Furthermore, it is necessary to examine whether or not the policies related to these products can prevent public skepticism regarding them. This empirical study examining the relationship between personal experiences related to the policy and acceptance of the innovative products of hydrogen fuel cell vehicles shows that government involvement in technology targeting and promotions administered by the 'low carbon, green growth' agenda rarely stimulate potential customers' purchase intentions. Thus, technology targeting administered by the 'low carbon, green growth' agenda needs to be reconciled with customer responses to the future market. - Highlights: > Experience of the 'low carbon, green growth' policy affects perception of it. > Positive perception on the policy seldom arouses positive perception on HFCV performance. > Technology targeting by the policy rarely stimulates purchase intention of HFCV. > Desire to be regarded as a person with environment concern impacts purchase intentions.> Technology targeting by the policy needs to be reconciled with customer responses to it.

  10. The Statistical Analysis Techniques to Support the NGNP Fuel Performance Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Bihn T. Pham; Jeffrey J. Einerson

    2010-06-01

    This paper describes the development and application of statistical analysis techniques to support the AGR experimental program on NGNP fuel performance. The experiments conducted in the Idaho National Laboratory’s Advanced Test Reactor employ fuel compacts placed in a graphite cylinder shrouded by a steel capsule. The tests are instrumented with thermocouples embedded in graphite blocks and the target quantity (fuel/graphite temperature) is regulated by the He-Ne gas mixture that fills the gap volume. Three techniques for statistical analysis, namely control charting, correlation analysis, and regression analysis, are implemented in the SAS-based NGNP Data Management and Analysis System (NDMAS) for automated processing and qualification of the AGR measured data. The NDMAS also stores daily neutronic (power) and thermal (heat transfer) code simulation results along with the measurement data, allowing for their combined use and comparative scrutiny. The ultimate objective of this work includes (a) a multi-faceted system for data monitoring and data accuracy testing, (b) identification of possible modes of diagnostics deterioration and changes in experimental conditions, (c) qualification of data for use in code validation, and (d) identification and use of data trends to support effective control of test conditions with respect to the test target. Analysis results and examples given in the paper show the three statistical analysis techniques providing a complementary capability to warn of thermocouple failures. It also suggests that the regression analysis models relating calculated fuel temperatures and thermocouple readings can enable online regulation of experimental parameters (i.e. gas mixture content), to effectively maintain the target quantity (fuel temperature) within a given range.

  11. FSV experience in support of the GT-MHR reactor physics, fuel performance, and graphite

    Energy Technology Data Exchange (ETDEWEB)

    Baxter, A.M.; McEachern, D.; Hanson, D.L.; Vollman, R.E.

    1994-11-01

    The Fort St. Vrain (FSV) power plant was the most recent operating graphite-moderated, helium-cooled nuclear power plant in the United States. Many similarities exist between the FSV design and the current design of the GT-MHR. Both designs use graphite as the basic building blocks of the core, as structural material, in the reflectors, and as a neutron moderator. Both designs use hexagonal fuel elements containing cylindrical fuel rods with coated fuel particles. Helium is the coolant and the power densities vary by less than 5%. Since material and geometric properties of the GT-MHR core am very similar to the FSV core, it is logical to draw upon the FSV experience in support of the GT-MHR design. In the Physics area, testing at FSV during the first three cycles of operation has confirmed that the calculational models used for the core design were very successful in predicting the core nuclear performance from initial cold criticality through power operation and refueling. There was excellent agreement between predicted and measured initial core criticality and control rod positions during startup. Measured axial flux distributions were within 5% of the predicted value at the peak. The isothermal temperature coefficient at zero power was in agreement within 3%, and even the calculated temperature defect over the whole operating range for cycle 3 was within 8% of the measured defect. In the Fuel Performance area, fuel particle coating performance, and fission gas release predictions and an overall plateout analysis were performed for decommissioning purposes. A comparison between predicted and measured fission gas release histories of Kr-85m and Xe-138 and a similar comparison with specific circulator plateout data indicated good agreement between prediction and measured data. Only I-131 plateout data was overpredicted, while Cs-137 data was underpredicted.

  12. 18 years experience on UF{sub 6} handling at Japanese nuclear fuel manufacturer

    Energy Technology Data Exchange (ETDEWEB)

    Fujinaga, H.; Yamazaki, N.; Takebe, N. [Japan Nucelar Fuel Conversion Co., Ltd., Ibaraki (Japan)

    1991-12-31

    In the spring of 1991, a leading nuclear fuel manufacturing company in Japan, celebrated its 18th anniversary. Since 1973, the company has produced over 5000 metric ton of ceramic grade UO{sub 2} powder to supply to Japanese fabricators, without major accident/incident and especially with a successful safety record on UF{sub 6} handling. The company`s 18 years experience on nuclear fuel manufacturing reveals that key factors for the safe handling of UF{sub 6} are (1) installing adequate facilities, equipped with safety devices, (2) providing UF{sub 6} handling manuals and executing them strictly, and (3) repeating on and off the job training for operators. In this paper, equipment and the operation mode for UF{sub 6} processing at their facility are discussed.

  13. Experience with incomplete control rod insertion in fuel with burnup exceeding approximately 40 GWD/MTU

    Energy Technology Data Exchange (ETDEWEB)

    Kee, E. [Houston Lighting & Power Co., Wadworth, TX (United States)

    1997-01-01

    Analysis and measurement experience with fuel assemblies having incomplete control rod insertion at burnups of approximately 40 GWD/MTU is presented. Control rod motion dynamics and simplified structural analyses are presented and compared to measurement data. Fuel assembly growth measurements taken with the plant Refueling Machine Z-Tape are described and presented. Bow measurements (including plug gauging) are described and potential improvements are suggested. The measurements described and analysis performed show that sufficient guide tube bow (either from creep or yield buckling) is present in some high burnup assemblies to stop the control rods before they reach their full limit of travel. Recommendations are made that, if implemented, could improve cost performance related to testing and analysis activities.

  14. Fuel performance annual report for 1991. Volume 9

    Energy Technology Data Exchange (ETDEWEB)

    Painter, C.L.; Alvis, J.M.; Beyer, C.E. [Pacific Northwest Lab., Richland, WA (United States); Marion, A.L. [Oregon State Univ., Corvallis, OR (United States). Dept. of Nuclear Engineering; Payne, G.A. [Northwest Coll. and Univ. Association for Science, Richland, WA (United States); Kendrick, E.D. [Nuclear Regulatory Commission, Washington, DC (United States)

    1994-08-01

    This report is the fourteenth in a series that provides a compilation of information regarding commercial nuclear fuel performance. The series of annual reports were developed as a result of interest expressed by the public, advising bodies, and the US Nuclear Regulatory Commission (NRC) for public availability of information pertaining to commercial nuclear fuel performance. During 1991, the nuclear industry`s focus regarding fuel continued to be on extending burnup while maintaining fuel rod reliability. Utilities realize that high-burnup fuel reduces the amount of generated spent fuel, reduces fuel costs, reduces operational and maintenance costs, and improves plant capacity factors by extending operating cycles. Brief summaries of fuel operating experience, fuel design changes, fuel surveillance programs, high-burnup experience, problem areas, and items of general significance are provided.

  15. Design, Construction and Experiment on Imbert Downdraft Gasifier Using South Sumatera Biomass and Low Rank Coal as Fuel

    Directory of Open Access Journals (Sweden)

    Fajri Vidian

    2017-03-01

    Full Text Available The solid fuel must be converted to gas fuel or liquid fuel for application to internal combustion engine or gas turbine. Gasification is a technology to convert solid fuel into combustible gas. Gasification system generally consists of a gasifier, cyclone, spray tower and filter. This study is purposed to design, construction, and experiment of gasification system. The imbert downdraft gasifier was designed with 42 kg/h for the maximum capacity of fuel consumption, 90 cm for height, 26.8 cm for main diameter and 12 cm for throat diameter. The gasifier was constructed from stainless steel material of SUS 304. Biomass and low rank coal from South Sumatera, Indonesia was used as fuel. The result of the experiment showed that combustible gas was produced after 15 minutes operation in average. The air fuel ratio of low rank coal was 1.7 which was higher than biomass (1.1. Combustible gas stopped producing when the fuel went down below the throat of gasifier

  16. A systematic review of the reliability and validity of discrete choice experiments in valuing non-market environmental goods.

    Science.gov (United States)

    Rakotonarivo, O Sarobidy; Schaafsma, Marije; Hockley, Neal

    2016-12-01

    While discrete choice experiments (DCEs) are increasingly used in the field of environmental valuation, they remain controversial because of their hypothetical nature and the contested reliability and validity of their results. We systematically reviewed evidence on the validity and reliability of environmental DCEs from the past thirteen years (Jan 2003-February 2016). 107 articles met our inclusion criteria. These studies provide limited and mixed evidence of the reliability and validity of DCE. Valuation results were susceptible to small changes in survey design in 45% of outcomes reporting reliability measures. DCE results were generally consistent with those of other stated preference techniques (convergent validity), but hypothetical bias was common. Evidence supporting theoretical validity (consistency with assumptions of rational choice theory) was limited. In content validity tests, 2-90% of respondents protested against a feature of the survey, and a considerable proportion found DCEs to be incomprehensible or inconsequential (17-40% and 10-62% respectively). DCE remains useful for non-market valuation, but its results should be used with caution. Given the sparse and inconclusive evidence base, we recommend that tests of reliability and validity are more routinely integrated into DCE studies and suggest how this might be achieved. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  17. Design of an experiment to measure the decay heat of an irradiated PWR fuel: MERCI experiment; Conception d'une experience de mesure de la puissance residuelle d'un combustible irradie: l'experience MERCI

    Energy Technology Data Exchange (ETDEWEB)

    Bourganel, St

    2002-11-01

    After a reactor shutdown, a significant quantity of energy known as 'decay heat' continues to be generated from the irradiated fuel. This heat source is due to the disintegration energy of fission products and actinides. Decay heat determination of an irradiated fuel is of the utmost importance for safety analysis as the design cooling systems, spent fuel transport, or handling. Furthermore, the uncertainty on decay heat has a straight economic impact. The unloading fuel spent time is an example. The purpose of MERCI experiment (irradiated fuel decay heat measurement) consists in qualifying computer codes, particularly the DARWIN code system developed by the CEA in relation to industrial organizations, as EDF, FRAMATOME and COGEMA. To achieve this goal, a UOX fuel is irradiated in the vicinity of the OSIRIS research reactor, and then the decay heat is measured by using a calorimeter. The objective is to reduce the decay heat uncertainties from 8% to 3 or 4% at short cooling times. A full simulation on computer of the MERCI experiment has been achieved: fuel irradiation analysis is performed using transport code TRIPOLI4 and evolution code DARWIN/PEPIN2, and heat transfer with CASTEM2000 code. The results obtained are used for the design of this experiment. Moreover, we propose a calibration procedure decreasing the influence of uncertainty measurements and an interpretation method of the experimental results and evaluation of associated uncertainties. (author)

  18. Shock and vibration effects on performance reliability and mechanical integrity of proton exchange membrane fuel cells: A critical review and discussion

    Science.gov (United States)

    Haji Hosseinloo, Ashkan; Ehteshami, Mohsen Mousavi

    2017-10-01

    Performance reliability and mechanical integrity are the main bottlenecks in mass commercialization of PEMFCs for applications with inherent harsh environment such as automotive and aerospace applications. Imparted shock and vibration to the fuel cell in such applications could bring about numerous issues including clamping torque loosening, gas leakage, increased electrical resistance, and structural damage and breakage. Here, we provide a comprehensive review and critique of the literature focusing on the effects of mechanically harsh environment on PEMFCs, and at the end, we suggest two main future directions in FC technology research that need immediate attention: (i) developing a generic and adequately accurate dynamic model of PEMFCs to assess the dynamic response of FC devices, and (ii) designing effective and robust shock and vibration protection systems based on the developed models in (i).

  19. Accurate and reliable quantification of total microalgal fuel potential as fatty acid methyl esters by in situ transesterification

    Energy Technology Data Exchange (ETDEWEB)

    Laurens, Lieve M.L.; Quinn, Matthew; Wychen, Stefanie van; Templeton, David W.; Wolfrum, Edward J. [National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO (United States)

    2012-04-15

    In the context of algal biofuels, lipids, or better aliphatic chains of the fatty acids, are perhaps the most important constituents of algal biomass. Accurate quantification of lipids and their respective fuel yield is crucial for comparison of algal strains and growth conditions and for process monitoring. As an alternative to traditional solvent-based lipid extraction procedures, we have developed a robust whole-biomass in situ transesterification procedure for quantification of algal lipids (as fatty acid methyl esters, FAMEs) that (a) can be carried out on a small scale (using 4-7 mg of biomass), (b) is applicable to a range of different species, (c) consists of a single-step reaction, (d) is robust over a range of different temperature and time combinations, and (e) tolerant to at least 50% water in the biomass. Unlike gravimetric lipid quantification, which can over- or underestimate the lipid content, whole biomass transesterification reflects the true potential fuel yield of algal biomass. We report here on the comparison of the yield of FAMEs by using different catalysts and catalyst combinations, with the acid catalyst HCl providing a consistently high level of conversion of fatty acids with a precision of 1.9% relative standard deviation. We investigate the influence of reaction time, temperature, and biomass water content on the measured FAME content and profile for 4 different samples of algae (replete and deplete Chlorella vulgaris, replete Phaeodactylum tricornutum, and replete Nannochloropsis sp.). We conclude by demonstrating a full mass balance closure of all fatty acids around a traditional lipid extraction process. (orig.)

  20. Accurate and Reliable Quantification of Total Microalgal Fuel Potential as Fatty Acid Methyl Esters by in situ Transesterfication

    Energy Technology Data Exchange (ETDEWEB)

    Laurens, L. M. L.; Quinn, M.; Van Wychen, S.; Templeton, D. W.; Wolfrum, E. J.

    2012-04-01

    In the context of algal biofuels, lipids, or better aliphatic chains of the fatty acids, are perhaps the most important constituents of algal biomass. Accurate quantification of lipids and their respective fuel yield is crucial for comparison of algal strains and growth conditions and for process monitoring. As an alternative to traditional solvent-based lipid extraction procedures, we have developed a robust whole-biomass in situ transesterification procedure for quantification of algal lipids (as fatty acid methyl esters, FAMEs) that (a) can be carried out on a small scale (using 4-7 mg of biomass), (b) is applicable to a range of different species, (c) consists of a single-step reaction, (d) is robust over a range of different temperature and time combinations, and (e) tolerant to at least 50% water in the biomass. Unlike gravimetric lipid quantification, which can over- or underestimate the lipid content, whole biomass transesterification reflects the true potential fuel yield of algal biomass. We report here on the comparison of the yield of FAMEs by using different catalysts and catalyst combinations, with the acid catalyst HCl providing a consistently high level of conversion of fatty acids with a precision of 1.9% relative standard deviation. We investigate the influence of reaction time, temperature, and biomass water content on the measured FAME content and profile for 4 different samples of algae (replete and deplete Chlorella vulgaris, replete Phaeodactylum tricornutum, and replete Nannochloropsis sp.). We conclude by demonstrating a full mass balance closure of all fatty acids around a traditional lipid extraction process.

  1. Developing the User Experience for a Next Generation Nuclear Fuel Cycle Simulator (NGFCS)

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, Paul H. [Univ. of Wisconsin, Madison, WI (United States); Schneider, Erich [Univ. of Texas, Austin, TX (United States); Pascucci, Valerio [Univ. of Utah, Salt Lake City, UT (United States); Livnat, Yarden [Univ. of Utah, Salt Lake City, UT (United States); Hiromoto, Robert [Univ. of Idaho, Moscow, ID (United States); Scopatz, Anthony [Univ. of Wisconsin, Madison, WI (United States); Brossard, Dominique [Univ. of Wisconsin, Madison, WI (United States); Scheufele, Dietram [Univ. of Wisconsin, Madison, WI (United States)

    2017-07-30

    This project made substantial progress on its original aim for providing a modern user experience for nuclear fuel cycle analysis while also creating a robust and functional next- generation fuel cycle simulator. The Cyclus kernel experienced a dramatic clari cation of its interfaces and data model, becoming a full- edged agent-based framework, with strong support for third party developers of novel archetypes. The most important contribution of this project to the the development of Cyclus was the introduction of tools to facilitate archetype development. These include automated code generation of routine archetype components, metadata annotations to provide re ection and rich description of each data member's purpose, and mechanisms for input validation and output of complex data. A comprehensive social science investigation of decision makers' interests in nuclear fuel cycles, and speci cally their interests in nuclear fuel cycle simulators (NFCSs) as tools for understanding nuclear fuel cycle options, was conducted. This included document review and analysis, stakeholder interviews, and a survey of decision makers. This information was used to study the role of visualization formats and features in communicating information about nuclear fuel cycles. A exible and user-friendly tool was developed for building Cyclus analysis models, featuring a drag-and-drop interface and automatic input form generation for novel archetypes. Cycic allows users to design fuel cycles from arbitrary collections of facilities for the rst time, with mechanisms that contribute to consistency within that fuel cycle. Interacting with some of the metadata capabilities introduced in the above-mentioned tools to support archetype development, Cycic also automates the generation of user input forms for novel archetypes with little to no special knowledge required by the archetype developers. Translation of the fundamental metrics of Cyclus into more interesting quantities is

  2. Reliability of measuring anomalous experience: the Bonn Scale for the Assessment of Basic Symptoms

    DEFF Research Database (Denmark)

    Vollmer-Larsen, Anne; Handest, Peter; Parnas, Josef

    2007-01-01

    in identifying the patients at risk of psychosis. Some of these anomalies are described in the Bonn Scale for the Assessment of Basic Symptoms (BSABS). We examined the reliability of this instrument. SAMPLING AND METHOD: 18 hospitalised patients accepted to participate in a psychopathological interview assessing...

  3. The reliability of assessment criteria for undergraduate medical students' communication skills portfolios: the Nottingham experience.

    Science.gov (United States)

    Rees, Charlotte E; Sheard, Charlotte E

    2004-02-01

    Some educators have argued that portfolios should not be assessed summatively because there is little evidence supporting the reliability of their assessment. This study aims to determine the reliability of assessment criteria used for a portfolio at the University of Nottingham. Two independent analysts assessed a random sample of portfolios (n = 100, 49.5%) using criterion-referenced assessment. Students' performances were examined against subjective items in five areas: 1) portfolio structure, 2) level of critical reflection, 3) level of skills development, 4) use of documentary evidence, and 5) use of relevant literature. These subjective judgements were later converted into quantitative scales ranging from 0 to 3 so that interrater reliability could be established. The level of agreement between the two analysts for the total percentage score was established using an intraclass correlation coefficient and for the individual items using weighted kappa coefficients. The level of agreement between the two raters for the total percentage score was 0.771 (95% CI = 0.678, 0.840), as measured by an intraclass correlation coefficient. The levels of agreement between the two raters for the individual items of the assessment criteria ranged from kappa=0.359 (item 3) to kappa=0.693 (item 4). This study provides some support for the summative assessment of portfolios. The findings suggest that discussion and negotiation between independent assessors can enhance the reliability of assessment criteria. Therefore, medical educators are encouraged to use such procedures in the summative assessment of portfolios.

  4. Is surgeons' experience important on intra- and inter-observer reliability of classifications used for adult femoral neck fracture?

    OpenAIRE

    Turgut, Ali; Kumbaracı, Mert; Kalenderer, Önder; İlyas, Gökhan; Bacaksız, Tayfun; Karapınar, Levent

    2017-01-01

    Purpose: To evaluate whether surgeons' experience affect inter- and intra-observer reliability among mostly used classification systems for femoral neck fractures. Material and Methods: A power point presentation was prepared with 107 slides which were antero-posterior radiographs of each femoral neck fracture. 5 residents, 5 orthopaedic surgeons and 5 senior orthopaedic surgeons reviewed this presentation and classified the fractures according to Garden, Pauwels and AO classifications. ...

  5. Frontiers of reliability

    CERN Document Server

    Basu, Asit P; Basu, Sujit K

    1998-01-01

    This volume presents recent results in reliability theory by leading experts in the world. It will prove valuable for researchers, and users of reliability theory. It consists of refereed invited papers on a broad spectrum of topics in reliability. The subjects covered include Bayesian reliability, Bayesian reliability modeling, confounding in a series system, DF tests, Edgeworth approximation to reliability, estimation under random censoring, fault tree reduction for reliability, inference about changes in hazard rates, information theory and reliability, mixture experiment, mixture of Weibul

  6. Design and Status of the NGNP Fuel Experiment AGR-3/4 Irradiated in the Advanced Test Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Blaine Grover

    2012-10-01

    The United States Department of Energy’s Next Generation Nuclear Plant (NGNP) Advanced Gas Reactor (AGR) Fuel Development and Qualification Program will be irradiating up to seven separate low enriched uranium (LEU) tri-isotopic (TRISO) particle fuel (in compact form) experiments in the Advanced Test Reactor (ATR) located at the Idaho National Laboratory (INL). These irradiations and fuel development are being accomplished to support development of the next generation reactors in the United States, and will be irradiated over the next several years to demonstrate and qualify new TRISO coated particle fuel for use in high temperature gas reactors. The goals of the irradiation experiments are to provide irradiation performance data to support fuel process development, to qualify fuel for normal operating conditions, to support development and validation of fuel performance and fission product transport models and codes, and to provide irradiated fuel and materials for post irradiation examination (PIE) and safety testing. The experiments, which will each consist of at least six separate capsules, will be irradiated in an inert sweep gas atmosphere with individual on-line temperature monitoring and control of each capsule. The sweep gas will also have on-line fission product monitoring on its effluent to track performance of the fuel in each individual capsule during irradiation. The first experiment (designated AGR-1) started irradiation in December 2006 and was completed in November 2009. The second experiment (AGR-2) started irradiation in June 2010 and is currently scheduled to be completed in April 2013. The third and fourth experiments have been combined into a single experiment designated AGR-3/4, which started its irradiation in December 2011 and is currently scheduled to be completed in November 2013. Since the purpose of this experiment is to provide data on fission product migration and retention in the NGNP reactor, the design of this experiment is

  7. Reliability of Margin Assessment after Surgery for Extremity Soft Tissue Sarcoma: The SSG Experience

    Directory of Open Access Journals (Sweden)

    Clement S. Trovik

    2012-01-01

    Full Text Available Surgery remains the mainstay of soft tissue sarcoma (STS treatment and has been the primary treatment for the majority of patients in Scandinavia during the last 30 years although the use of adjuvant radiotherapy has increased. Patient and treatment characteristics have been recorded in the Scandinavian Sarcoma Group (SSG Register since 1987. When the effect of new radiotherapy guidelines from 1998 was evaluated, the reliability of surgical margin assessments among different Scandinavian institutions was investigated. Margins were reevaluated by a panel of sarcoma surgeons, studying pathology and surgical reports from 117 patients, randomly selected among 470 recorded patients treated between 1998–2003. In 80% of cases, the panel agreed with the original classification. Disagreement was most frequent when addressing the distinction between marginal and wide margins. Considered the element of judgment inherent in all margin assessment, we find this reliability acceptable for using the Register for studies of local control of STS.

  8. Modeling and Simulation of Reliability & Maintainability Parameters for Reusable Launch Vehicles using Design of Experiments

    Science.gov (United States)

    Unal, Resit; Morris, W. Douglas; White, Nancy H.; Lepsch, Roger A.

    2004-01-01

    This paper describes the development of a methodology for estimating reliability and maintainability distribution parameters for a reusable launch vehicle. A disciplinary analysis code and experimental designs are used to construct approximation models for performance characteristics. These models are then used in a simulation study to estimate performance characteristic distributions efficiently. The effectiveness and limitations of the developed methodology for launch vehicle operations simulations are also discussed.

  9. Analysis of Fuel Cell Markets in Japan and the US: Experience Curve Development and Cost Reduction Disaggregation

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Max [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Smith, Sarah J. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Sohn, Michael D. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2016-07-15

    Fuel cells are both a longstanding and emerging technology for stationary and transportation applications, and their future use will likely be critical for the deep decarbonization of global energy systems. As we look into future applications, a key challenge for policy-makers and technology market forecasters who seek to track and/or accelerate their market adoption is the ability to forecast market costs of the fuel cells as technology innovations are incorporated into market products. Specifically, there is a need to estimate technology learning rates, which are rates of cost reduction versus production volume. Unfortunately, no literature exists for forecasting future learning rates for fuel cells. In this paper, we look retrospectively to estimate learning rates for two fuel cell deployment programs: (1) the micro-combined heat and power (CHP) program in Japan, and (2) the Self-Generation Incentive Program (SGIP) in California. These two examples have a relatively broad set of historical market data and thus provide an informative and international comparison of distinct fuel cell technologies and government deployment programs. We develop a generalized procedure for disaggregating experience-curve cost-reductions in order to disaggregate the Japanese fuel cell micro-CHP market into its constituent components, and we derive and present a range of learning rates that may explain observed market trends. Finally, we explore the differences in the technology development ecosystem and market conditions that may have contributed to the observed differences in cost reduction and draw policy observations for the market adoption of future fuel cell technologies. The scientific and policy contributions of this paper are the first comparative experience curve analysis of past fuel cell technologies in two distinct markets, and the first quantitative comparison of a detailed cost model of fuel cell systems with actual market data. The resulting approach is applicable to

  10. Developing safe and reliable LNG supply chains in teh new global environment: experience and lessons from six continents

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, Ernst; Danielsen, Hans Kristian; Dweck, Jacob; Mareino, Vince; Eriksen, Remi

    2007-07-01

    This paper explores the dynamics of risk management in the context of specific recent experiences in the liquefied natural gas (LNG) business. The paper notes the overall success of the LNG business in ensuring safety and reliability, and highlights the opportunities and dangers of recent business growth. Risks are organised by theme, with focuses on politics and regulation, safety and security, environmental impact, public perception, technological innovation, cost and time management, competence and quality of assets, and harsh climates. Developers and other stakeholders are encouraged to draw lessons from these experiences when attempting to model the interplay of social, commercial and technical factors in LNG project development. (auth)

  11. UP TO 100,000 RELIABLE STRONG GRAVITATIONAL LENSES IN FUTURE DARK ENERGY EXPERIMENTS

    Energy Technology Data Exchange (ETDEWEB)

    Serjeant, S. [Department of Physical Sciences, The Open University, Milton Keynes MK7 6AA (United Kingdom)

    2014-09-20

    The Euclid space telescope will observe ∼10{sup 5} strong galaxy-galaxy gravitational lens events in its wide field imaging survey over around half the sky, but identifying the gravitational lenses from their observed morphologies requires solving the difficult problem of reliably separating the lensed sources from contaminant populations, such as tidal tails, as well as presenting challenges for spectroscopic follow-up redshift campaigns. Here I present alternative selection techniques for strong gravitational lenses in both Euclid and the Square Kilometre Array, exploiting the strong magnification bias present in the steep end of the Hα luminosity function and the H I mass function. Around 10{sup 3} strong lensing events are detectable with this method in the Euclid wide survey. While only ∼1% of the total haul of Euclid lenses, this sample has ∼100% reliability, known source redshifts, high signal-to-noise, and a magnification-based selection independent of assumptions of lens morphology. With the proposed Square Kilometre Array dark energy survey, the numbers of reliable strong gravitational lenses with source redshifts can reach 10{sup 5}.

  12. Influence of coolant temperature and pressure on destructive forces at fuel failure in the NSRR experiment

    Energy Technology Data Exchange (ETDEWEB)

    Kusagaya, Kazuyuki [Global Nuclear Fuel - Japan Co., Ltd., Yokosuka, Kanagawa (Japan); Sugiyama, Tomoyuki; Nakamura, Takehiko; Uetsuka, Hiroshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2003-01-01

    In order to design a new experimental capsule to be used in the NSRR (Nuclear Safety Research Reactor) experiment with the temperature and pressure conditions in a typical commercial BWR, coolant temperature and pressure influence is estimated for destructive forces during fuel rod failure in the experiment simulating reactivity-initiated accident (RIA). Considering steam property dependence on temperature and pressure, it is qualitatively shown that the destructive forces in the BWR operation condition are smaller than those in the room temperature and atmospheric pressure condition. Water column velocity, which determines impact by water hammer, is further investigated quantitatively by modeling the experimental system and water hammer phenomenon. As a result, the maximum velocity of the water column in the BWR operation conditions is calculated to be only about 10% of that in the room temperature and atmospheric pressure condition. (author)

  13. UNCERTAINTY QUANTIFICATION OF CALCULATED TEMPERATURES FOR ADVANCED GAS REACTOR FUEL IRRADIATION EXPERIMENTS

    Energy Technology Data Exchange (ETDEWEB)

    Pham, Binh Thi-Cam [Idaho National Laboratory; Hawkes, Grant Lynn [Idaho National Laboratory; Einerson, Jeffrey James [Idaho National Laboratory

    2015-08-01

    This paper presents the quantification of uncertainty of the calculated temperature data for the Advanced Gas Reactor (AGR) fuel irradiation experiments conducted in the Advanced Test Reactor at Idaho National Laboratory in support of the Advanced Reactor Technology Research and Development program. Recognizing uncertainties inherent in physics and thermal simulations of the AGR tests, the results of the numerical simulations are used in combination with statistical analysis methods to improve qualification of measured data. The temperature simulation data for AGR tests are also used for validation of the fission product transport and fuel performance simulation models. These crucial roles of the calculated fuel temperatures in ensuring achievement of the AGR experimental program objectives require accurate determination of the model temperature uncertainties. To quantify the uncertainty of AGR calculated temperatures, this study identifies and analyzes ABAQUS model parameters of potential importance to the AGR predicted fuel temperatures. The selection of input parameters for uncertainty quantification of the AGR calculated temperatures is based on the ranking of their influences on variation of temperature predictions. Thus, selected input parameters include those with high sensitivity and those with large uncertainty. Propagation of model parameter uncertainty and sensitivity is then used to quantify the overall uncertainty of AGR calculated temperatures. Expert judgment is used as the basis to specify the uncertainty range for selected input parameters. The input uncertainties are dynamic accounting for the effect of unplanned events and changes in thermal properties of capsule components over extended exposure to high temperature and fast neutron irradiation. The sensitivity analysis performed in this work went beyond the traditional local sensitivity. Using experimental design, analysis of pairwise interactions of model parameters was performed to establish

  14. All-Russia Thermal Engineering Institute experience in using difficult to burn fuels in the power industry

    Science.gov (United States)

    Tugov, A. N.; Ryabov, G. A.; Shtegman, A. V.; Ryzhii, I. A.; Litun, D. S.

    2016-07-01

    This article presents the results of the research carried out at the All-Russia Thermal Engineering Institute (VTI) aimed at using saline coal, municipal solid waste and bark waste, sunflower husk, and nesting/ manure materials from poultry farms. The results of saline coal burning experience in Troitsk and Verkhny Tagil thermal power plants (TPP) show that when switching the boiler to this coal, it is necessary to take into account its operating reliability and environmental safety. Due to increased chlorine content in saline coal, the concentration of hydrogen chloride can make over 500 mg/m3. That this very fact causes the sharp increase of acidity in sludge and the resulting damage of hydraulic ash removal system equipment at these power stations has been proven. High concentration of HCl can trigger damage of the steam superheater due to high-temperature corrosion and result in a danger of low-temperature corrosion of air heating surfaces. Besides, increased HCl emissions worsen the environmental characteristics of the boiler operation on the whole. The data on waste-to-energy research for municipal solid waste (MSW) has been generalized. Based on the results of mastering various technologies of MSW thermal processing at special plants nos. 2 and 4 in Moscow, as well as laboratory, bench, and industrial studies, the principal technical solutions to be implemented in the modern domestic thermal power plant with the installed capacity of 24 MW and MSW as the primary fuel type has been developed. The experience of the VTI in burning various kinds of organic waste—bark waste, sunflower husk, and nesting/manure materials from poultry farms—has been analyzed.

  15. Reliability of Med-El Cochlear Implants in children. The Romania Experience.

    Directory of Open Access Journals (Sweden)

    Eugen Horatiu Stefanescu

    2016-07-01

    Full Text Available Introduction: Early detection of hearing loss significantly lowered the age of cochlear implantation. A failed CI is a very problematic issue for the child and family and seems to be, for the moment, inevitable. This is a retrospective review aimed to evaluate the reliability of Med-El devices implanted in children in Romania. Materials and Methods: We designed a questionnaire to assess the incidence, the time elapsed and the reason of total device failure. Medical-surgical data were collected from children who received Med-El cochlear implants since the start of the National Cochlear Implant Program in 2001. Results: There were 256 patients included. Failure Rate (6,64% and Cumulative Survival Rate (95,31% at 5 years were calculated. The majority of the hard and soft failures were encountered in Pulsar devices. Flap necrosis was the most frequent medical/surgical reason for re-plantation. There was only one case of posttraumatic device failure. Time elapsed to device failure was short – 22 months on average. Conclusion: Cochlear implant reliability data should be considered during the choice of an implant for each individual patient. This study confirms the safety and efficacy of Med-El cochlear implants in children for both ceramic and non-ceramic devices.

  16. Experience on wet storage spent fuel sipping at IEA-R1 Brazilian research reactor

    Energy Technology Data Exchange (ETDEWEB)

    Perrotta, J.A.; Terremoto, L.A.A.; Zeituni, C.A. [Instituto de Pesquisas Energeticas e Nucleares, Sao Paulo (Brazil). Divisao de Engenharia do Nucleo

    1997-12-01

    The IEA-R1 research reactor of the Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP) is a pool type reactor of B and W design, that has been operating since 1957 at a power of 2 MW. Irradiated (spent) fuels have been stored at the facility during the various years of operation. At present there are 40 spent fuel assemblies at dry storage, 79 spent fuel assemblies at wet storage and 30 fuel assemblies in the core. The oldest fuels are of United States origin, made with U-Al alloy, both of LEU and HEU MTR fuel type. many of these fuel assemblies have corrosion pits along their lateral fuel plates. These pits originate by galvanic corrosion between the fuel plate and the stainless steel storage racks. As a consequence of the possibility of sending the irradiated old fuels back to the U.S.A., sipping tests were performed with the spent fuel assemblies. The reason for this was to evaluate their {sup 137}Cs leaking rate, if any. This work describes the procedure and methodology used to perform the sipping tests with the fuel assemblies at the storage pool, and presents the results obtained for the {sup 137}Cs sipping water activity for each fuel assembly. A correlation is made between the corrosion pits and the activity values measured. A {sup 137}Cs leaking rate is determined and compared to the criteria established for canning spent fuel assemblies before shipment. (author).

  17. Experience on wet storage spent fuel sipping at IEA-R1 Brazilian research reactor

    Energy Technology Data Exchange (ETDEWEB)

    Perrotta, J.A.; Terremoto, L.A.A.; Zeituni, C.A

    1998-03-01

    The IEA-R1 research reactor of the Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP) is a pool type reactor of B and W design, that has been operating since 1957 at a power of 2 MW. Irradiated (spent) fuels have been stored at the facility during the various years of operation. At present there are 40 spent fuel assemblies at dry storage, 79 spent fuel assemblies at wet storage and 30 fuel assemblies in the core. The oldest fuels are of United States origin, made with U-Al alloy, both of LEU and HEU MTR fuel type. Many of these fuel assemblies have corrosion pits along their lateral fuel plates. These pits originate by galvanic corrosion between the fuel plate and the stainless steel storage racks. As a consequence of the possibility of sending the irradiated old fuels back the U.S.A., sipping tests were performed with the spent fuel assemblies. The reason for this was to evaluate their {sup 137}Cs leaking rate, if any. This work describes the procedure and methodology used to perform the sipping tests with the fuel assemblies at the storage pool, and presents the results obtained for the {sup 137}Cs sipping water activity for each fuel assembly. A correlation is made between the corrosion pits and the activity values measured. A {sup 137}Cs leaking rate is determined and compared to the criteria established for canning spent fuel assemblies before shipment.

  18. LMFBR source term experiments in the Fuel Aerosol Simulant Test (FAST) facility

    Energy Technology Data Exchange (ETDEWEB)

    Petrykowski, J.C.; Longest, A.W.

    1985-01-01

    The transport of uranium dioxide (UO/sub 2/) aerosol through liquid sodium was studied in a series of ten experiments in the Fuel Aerosol Simulant Test (FAST) facility at Oak Ridge National Laboratory (ORNL). The experiments were designed to provide a mechanistic basis for evaluating the radiological source term associated with a postulated, energetic core disruptive accident (CDA) in a liquid metal fast breeder reactor (LMFBR). Aerosol was generated by capacitor discharge vaporization of UO/sub 2/ pellets which were submerged in a sodium pool under an argon cover gas. Measurements of the pool and cover gas pressures were used to study the transport of aerosol contained by vapor bubbles within the pool. Samples of cover gas were filtered to determine the quantity of aerosol released from the pool. The depth at which the aerosol was generated was found to be the most critical parameter affecting release. The largest release was observed in the baseline experiment where the sample was vaporized above the sodium pool. In the nine ''undersodium'' experiments aerosol was generated beneath the surface of the pool at depths varying from 30 to 1060 mm. The mass of aerosol released from the pool was found to be a very small fraction of the original specimen. It appears that the bulk of aerosol was contained by bubbles which collapsed within the pool. 18 refs., 11 figs., 4 tabs.

  19. MELCOR 1.8.2 assessment: The DF-4 BWR Damaged Fuel experiment

    Energy Technology Data Exchange (ETDEWEB)

    Tautges, T.J.

    1993-10-01

    MELCOR is a fully integrated, engineering-level computer code being developed at Sandia National Laboratories for the USNRC, that models the entire spectrum of severe accident phenomena in a unified framework for both BWRs and PWRs. As a part of an ongoing assessment, program, MELCOR has been used to model the ACRR in-pile DF-4 Damaged Fuel experiment. DF-4 provided data for early phase melt progression in BWR fuel assemblies, particularly for phenomena associated with eutectic interactions in the BWR control blade and zircaloy oxidation in the canister and cladding. MELCOR provided good agreement with experimental data in the key areas of eutectic material behavior and canister and cladding oxidation. Several shortcomings associated with the MELCOR modeling of BWR geometries were found and corrected. Twenty-five sensitivity studies were performed on COR, HS and CVH parameters. These studies showed that the new MELCOR eutectics model played an important role in predicting control blade behavior. These studies revealed slight time step dependence and no machine dependencies. Comparisons made with the results from four best-estimate codes showed that MELCOR did as well as these codes in matching DF-4 experimental data.

  20. Experiments on Induction Times of Diesel-Fuels and its Surrogates

    Science.gov (United States)

    Eigenbrod, Christian; Reimert, Manfredo; Marks, Guenther; Rickmers, Peter; Klinkov, Konstantin; Moriue, Osamu

    Aiming for as low polluting combustion control as possible in Diesel-engines or gas-turbines, pre-vaporized and pre-mixed combustion at low mean temperature levels marks the goal. Low-est emissions of nitric-oxides are achievable at combustion temperatures associated to mixture ratios close to the lean flammability limit. In order to prevent local mixture ratios to be below the flammability limit (resulting in flame extinction or generation of unburned hydrocarbons and carbon-monoxide) or to be richer than required (resulting in more nitric-oxide than possi-ble), well-stirred conditioning is required. The time needed for spray generation, vaporization and turbulent mixing is limited through the induction time to self-ignition in a hot high-pressure ambiance. Therefore, detailed knowledge about the autoignition of fuels is a pre-requisit. Experiments were performed at the Bremen drop tower to investigate the self-ignition behavior of single droplets of fossil-Diesel oil, rapeseed-oil, Gas-to-Liquid (GTL) synthetic Diesel-oil and the fossil Diesel surrogates n-heptane, n-tetradecane, 50 n-tetradecane/ 50 1-methylnaphthalene as well as on the GTL-surrogates n-tetradecane / bicyclohexyl and n-tetradecane / 2,2,4,4,6,8,8-heptamethylnonane (iso-cetane). The rules for selection of the above fuels and the experimental results are presented and dis-cussed.

  1. Examination of anomalous self-experience in first-episode psychosis: interrater reliability

    DEFF Research Database (Denmark)

    Møller, Paul; Haug, Elisabeth; Raballo, Andrea

    2011-01-01

    Background: The growing research focus on early detection of schizophrenia has fostered an increasing interest in the nonpsychotic experiential anomalies that may antedate schizophrenia spectrum disorders and assist early differential diagnosis. The Examination of Anomalous Self-Experience (EASE)...

  2. Examination of anomalous self-experience in first-episode psychosis: interrater reliability

    DEFF Research Database (Denmark)

    Møller, Paul; Haug, Elisabeth; Raballo, Andrea

    2011-01-01

    Background: The growing research focus on early detection of schizophrenia has fostered an increasing interest in the nonpsychotic experiential anomalies that may antedate schizophrenia spectrum disorders and assist early differential diagnosis. The Examination of Anomalous Self-Experience (EASE)...

  3. The Study on Fatigue Experiment and Reliability Life of Submarine Pipeline Steel

    OpenAIRE

    Yan Yifei; Shao Bing; Liu Jinkun; Cheng Lufeng

    2013-01-01

    The aim of the fatigue experiment study is to solve the fatigue fracture problem of X70 submarine tubing when it is under the scouring effect of offshore current. The multilevel fatigue experiments are carried out following the internation (GB4337-84) recommended method. The standard round bar fatigue specimen was made by the material of submarine pipeline steel. The fatigue life of submarine pipeline steel in different survival probability and P-S-N curve were achieved. According to reliabil...

  4. Operating Experience and Reliability Improvements on the 5 kW CW Klystron at Jefferson Lab

    Science.gov (United States)

    Nelson, R.; Holben, S.

    1997-05-01

    With substantial operating hours on the RF system, considerable information on reliability of the 5 kW CW klystrons has been obtained. High early failure rates led to examination of the operating conditions and failure modes. Internal ceramic contamination caused premature failure of gun potting material and ultimate tube demise through arcing or ceramic fracture. A planned course of repotting and reconditioning of approximately 300 klystrons, plus careful attention to operating conditions and periodic analysis of operational data, has substantially reduced the failure rate. It is anticipated that implementation of planned supplemental monitoring systems for the klystrons will allow most catastrophic failures to be avoided. By predicting end of life, tubes can be changed out before they fail, thus minimizing unplanned downtime. Initial tests have also been conducted on this same klystron operated at higher voltages with resultant higher output power. The outcome of these tests will provide information to be considered for future upgrades to the accelerator.

  5. Scoring sacroiliac joints by magnetic resonance imaging. A multiple-reader reliability experiment

    DEFF Research Database (Denmark)

    Landewe, Robert B.M.; Hermann, Kay Geert A; Van Der Heijde, Desiree M.F.M

    2005-01-01

    Magnetic resonance imaging (MRI) of the sacroiliac (SI) joints and the spine is increasingly important in the assessment of inflammatory activity and structural damage in clinical trials with patients with ankylosing spondylitis (AS). We investigated inter-reader reliability and sensitivity...... electronically to 7 experienced readers from different countries (Europe, Canada). Readers scored the MRI by 3 different methods including: a global score (grading activity per SI joint); a more comprehensive global score (grading activity per SI joint per quadrant); and a detailed scoring system...... and sensitivity to change of scoring systems to be used in assessing activity of SI joints in clinical trials, and sets the conditions for further validation research in this field...

  6. Fuel Cell Demonstration Program

    Energy Technology Data Exchange (ETDEWEB)

    Gerald Brun

    2006-09-15

    In an effort to promote clean energy projects and aid in the commercialization of new fuel cell technologies the Long Island Power Authority (LIPA) initiated a Fuel Cell Demonstration Program in 1999 with six month deployments of Proton Exchange Membrane (PEM) non-commercial Beta model systems at partnering sites throughout Long Island. These projects facilitated significant developments in the technology, providing operating experience that allowed the manufacturer to produce fuel cells that were half the size of the Beta units and suitable for outdoor installations. In 2001, LIPA embarked on a large-scale effort to identify and develop measures that could improve the reliability and performance of future fuel cell technologies for electric utility applications and the concept to establish a fuel cell farm (Farm) of 75 units was developed. By the end of October of 2001, 75 Lorax 2.0 fuel cells had been installed at the West Babylon substation on Long Island, making it the first fuel cell demonstration of its kind and size anywhere in the world at the time. Designed to help LIPA study the feasibility of using fuel cells to operate in parallel with LIPA's electric grid system, the Farm operated 120 fuel cells over its lifetime of over 3 years including 3 generations of Plug Power fuel cells (Lorax 2.0, Lorax 3.0, Lorax 4.5). Of these 120 fuel cells, 20 Lorax 3.0 units operated under this Award from June 2002 to September 2004. In parallel with the operation of the Farm, LIPA recruited government and commercial/industrial customers to demonstrate fuel cells as on-site distributed generation. From December 2002 to February 2005, 17 fuel cells were tested and monitored at various customer sites throughout Long Island. The 37 fuel cells operated under this Award produced a total of 712,635 kWh. As fuel cell technology became more mature, performance improvements included a 1% increase in system efficiency. Including equipment, design, fuel, maintenance

  7. Investigation of the Feasibility of Utilizing Gamma Emission Computed Tomography in Evaluating Fission Product Migration in Irradiated TRISO Fuel Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Jason M. Harp; Paul A. Demkowicz

    2014-10-01

    In the High Temperature Gas-Cooled Reactor (HTGR) the TRISO particle fuel serves as the primary fission product containment. However the large number of TRISO particles present in proposed HTGRs dictates that there will be a small fraction (~10-4 to 10-5) of as manufactured and in-pile particle failures that will lead to some fission product release. The matrix material surrounding the TRISO particles in fuel compacts and the structural graphite holding the TRISO particles in place can also serve as sinks for containing any released fission products. However data on the migration of solid fission products through these materials is lacking. One of the primary goals of the AGR-3/4 experiment is to study fission product migration from failed TRISO particles in prototypic HTGR components such as structural graphite and compact matrix material. In this work, the potential for a Gamma Emission Computed Tomography (GECT) technique to non-destructively examine the fission product distribution in AGR-3/4 components and other irradiation experiments is explored. Specifically, the feasibility of using the Idaho National Laboratory (INL) Hot Fuels Examination Facility (HFEF) Precision Gamma Scanner (PGS) system for this GECT application is considered. To test the feasibility, the response of the PGS system to idealized fission product distributions has been simulated using Monte Carlo radiation transport simulations. Previous work that applied similar techniques during the AGR-1 experiment will also be discussed as well as planned uses for the GECT technique during the post irradiation examination of the AGR-2 experiment. The GECT technique has also been applied to other irradiated nuclear fuel systems that were currently available in the HFEF hot cell including oxide fuel pins, metallic fuel pins, and monolithic plate fuel.

  8. Experiment and numerical simulation on the performance of a kw-scale molten carbonate fuel cell stack

    Directory of Open Access Journals (Sweden)

    L. J. Yu

    2007-12-01

    Full Text Available A high-temperature molten carbonate fuel cell stack was studied experimentally and computationally. Experimental data for fuel cell temperature was obtained when the stack was running under given operational conditions. A 3-D CFD numerical model was set up and used to simulate the central fuel cell in the stack. It includes the mass, momentum and energy conservation equations, the ideal gas law and an empirical equation for cell voltage. The model was used to simulate the transient behavior of the fuel cell under the same operational conditions as those of the experiment. Simulation results show that the transient temperature and current and power densities reach their maximal values at the channel outlet. A comparison of the modeling results and the experimental data shows the good agreement.

  9. Reliability of the discrete choice experiment at the input and output level in patients with rheumatoid arthritis

    DEFF Research Database (Denmark)

    Skjoldborg, Ulla Slothuus; Lauridsen, Jørgen; Junker, Peter

    2009-01-01

    agents. Respondents participated in three face-to-face interviews over a period of 4 months. Reliability was measured both at the input level, where the consistency of matches made by respondents to the Discrete Choice Experiment (DCE) question between replications was determined, and at the output level......, where the parameters of the conjoint model were estimated and tested for joint significance and willingness to pay (WTP) confidence intervals were calculated. RESULTS: Input level: Of the 1661 choices made in survey 1, 1316 were repeated in survey 2. Based on the observed number of consistently repeated...

  10. Further Support of the Reliability of the Limit on Photon Mass Given by the Rotating Torsion Balance Experiment

    Institute of Scientific and Technical Information of China (English)

    刘琳霞; 邓罡

    2012-01-01

    We consider there is a vacancy in the plasma in the solar system, and calculate the vector potential produced by the magnetic field frozen in the plasma. The result shows that, in the vacancy, the vector potential produced by the magnetic field frozen in the plasma is much less than the large scale cosmic vector potential. This means if our earth is in such a vacancy, the total vector potential on the surface of the earth is dominated by the cosmic magnetic vector potential, which gives a further support of the reliability of the limit on photon mass given by rotating torsion balance experiment [Phys. Rev. Lett. 90 (2003) 081801].

  11. Experiments and Modeling of Multi-Component Fuel Behavior in Combustion

    Science.gov (United States)

    1984-05-01

    heteroatom components. Such models will be necessary input to the large computer codes which calculate the characteristics of two phase reacting flows...methane -nd acetylene accompanied by soot formation. The trends are similar for the two fuels except that JP-4 produces more methane than JP-7. Both fuels...fuels vii1 be increasingly important as the sources shift to heavier petroleum , oil shale, tar sands and coal derived fuels. The combustion of such

  12. Health and safety impacts of nuclear, geothermal, and fossil-fuel electric generation in California. Volume 7. Power plant reliability-availability and state regulation

    Energy Technology Data Exchange (ETDEWEB)

    Nero, A.V.; Bouromand, I.N.M.N.

    1977-01-01

    Data from the Edison Electric Institute annual report on equipment availability are briefly examined with a view to determining the breadth of effort which would be required to reduce outage time caused by equipment difficulties. For nuclear units, for several size categories of fossil units, and for gas turbine units, the basic data are examined to establish the basic operating experience and related outage and availability rates, and to assign outages to major plant systems. Related data giving detailed outage causes are grouped to yield data on component failure versus outage time, information that is required to determine the possible impact of research and regulatory efforts on reliability and availability.

  13. Heating experiments for flowability improvement of near-freezing aviation fuel

    Science.gov (United States)

    Friedman, R.; Stockemer, F. J.

    1984-01-01

    An experimental jet fuel with a -33 C freezing point was chilled in a wing tank simulator with superimposed fuel heating to improve low temperature flowability. Heating consisted of circulating a portion of the fuel to an external heat exchanger and returning the heated fuel to the tank. Flowability was determined by the mass percent of unpumpable fuel (holdup) left in the simulator upon withdrawal of fuel at the conclusion of testing. The study demonstrated that fuel heating is feasible and improves flowability as compared to that of baseline, unheated tests. Delayed heating with initiation when the fuel reaches a prescribed low temperature limit, showed promise of being more efficient than continuous heating. Regardless of the mode or rate of heating, complete flowability (zero holdup) could not be restored by fuel heating. The severe, extreme-day environment imposed by the test caused a very small amount of subfreezing fuel to be retained near the tank surfaces even at high rates of heating. Correlations of flowability established for unheated fuel tests also could be applied to the heated test results if based on boundary-layer temperature or a solid index (subfreezing point) characteristic of the fuel. Previously announced in STAR as N82-26483

  14. Piping: Over 100 years of experience: From empiricism towards reliability-based design

    NARCIS (Netherlands)

    Van Beek, V.M.; Knoeff, H.G.; Schweckendiek, T.

    2011-01-01

    Backward piping is the process of channel formation in a sandy aquifer under river dikes. During high water periods this process manifests itself by the formation of sand boils. A long history of cases and experiments has contributed to the insights into this phenomenon and has improved the ability

  15. Reliability-Based Optimal Design of Experiment Plans for Offshore Structures

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Faber, M. H.; Kroon, I. B.

    1993-01-01

    Design of cost optimal experiment plans on the basis of a preposterior analysis is discussed. In particular the planning of on-site response measurements on offshore structures in order to update probabilistic models for fatigue life estimation is addressed. Special emphasis is given to modelling...

  16. Piping: Over 100 years of experience: From empiricism towards reliability-based design

    NARCIS (Netherlands)

    Van Beek, V.M.; Knoeff, H.G.; Schweckendiek, T.

    2011-01-01

    Backward piping is the process of channel formation in a sandy aquifer under river dikes. During high water periods this process manifests itself by the formation of sand boils. A long history of cases and experiments has contributed to the insights into this phenomenon and has improved the ability

  17. Reliability and Quality Assurance Experience in Launcher Hold and Release System used in GSLV

    Directory of Open Access Journals (Sweden)

    J. Singaravelu

    2002-01-01

    Full Text Available The launcher hold and release system (LHRS was successfully used, for the first time, for GSLV-DI mission after thorough test and evaluation, in line with reliability and quality assurance (R&QA requirements. Various R&QA techniques are applied to make LHRS failure-free. Failure mode effect and criticality analysis (FMECA was used as a tool for identifying critical failure modes. Single-point failure modes (SPFMs identified from FMECA are strengthened by design modifications and the same are verified by testing. Testing philosophy is tailored to have more number of tests at the system level. Capability demonstration tests and failure mode simulation tests were carried out during system qualification phase. Acceptance tests are done on the flight hardware at launch pad to demonstrate better confidence on the system. This paper illustrates how R&QA techniques complimented and added value at different stages in the development cycle of LHRS, by means of few case studies. Testing methodologies adopted and problems encountered during the development and qualification phases are described in brief. Various problems surfaced during preparation for flight are also discussed.

  18. Qualitative soil moisture assessment in semi-arid Africa: the role of experience and training on inter-rater reliability

    Directory of Open Access Journals (Sweden)

    M. Rinderer

    2015-03-01

    Full Text Available Soil and water management is particularly relevant in semi-arid regions to enhance agricultural productivity. During periods of water scarcity soil moisture differences are important indicators of the soil water deficit and are traditionally used for allocating water resources among farmers of a village community. Here we present a simple, inexpensive soil wetness classification scheme based on qualitative indicators which one can see or touch on the soil surface. It incorporates the local farmers' knowledge on the best soil moisture conditions for seeding and brick making in the semi-arid environment of the study site near Arusha, Tanzania. The scheme was tested twice in 2014 with farmers, students and experts (April: 40 persons, June: 25 persons for inter-rater reliability, bias of individuals and functional relation between qualitative and quantitative soil moisture values. During the test in April farmers assigned the same wetness class in 46% of all cases while students and experts agreed in about 60% of all cases. Students who had been trained in how to apply the method gained higher inter-rater reliability than their colleagues with only a basic introduction. When repeating the test in June, participants were given improved instructions, organized in small sub-groups, which resulted in a higher inter-rater reliability among farmers. In 66% of all classifications farmers assigned the same wetness class and the spread of class assignments was smaller. This study demonstrates that a wetness classification scheme based on qualitative indicators is a robust tool and can be applied successfully regardless of experience in crop growing and education level when an in-depth introduction and training is provided. The use of a simple and clear layout of the assessment form is important for reliable wetness class assignments.

  19. Qualitative soil moisture assessment in semi-arid Africa - the role of experience and training on inter-rater reliability

    Science.gov (United States)

    Rinderer, M.; Komakech, H. C.; Müller, D.; Wiesenberg, G. L. B.; Seibert, J.

    2015-08-01

    Soil and water management is particularly relevant in semi-arid regions to enhance agricultural productivity. During periods of water scarcity, soil moisture differences are important indicators of the soil water deficit and are traditionally used for allocating water resources among farmers of a village community. Here we present a simple, inexpensive soil wetness classification scheme based on qualitative indicators which one can see or touch on the soil surface. It incorporates the local farmers' knowledge on the best soil moisture conditions for seeding and brick making in the semi-arid environment of the study site near Arusha, Tanzania. The scheme was tested twice in 2014 with farmers, students and experts (April: 40 persons, June: 25 persons) for inter-rater reliability, bias of individuals and functional relation between qualitative and quantitative soil moisture values. During the test in April farmers assigned the same wetness class in 46 % of all cases, while students and experts agreed on about 60 % of all cases. Students who had been trained in how to apply the method gained higher inter-rater reliability than their colleagues with only a basic introduction. When repeating the test in June, participants were given improved instructions, organized in small subgroups, which resulted in a higher inter-rater reliability among farmers. In 66 % of all classifications, farmers assigned the same wetness class and the spread of class assignments was smaller. This study demonstrates that a wetness classification scheme based on qualitative indicators is a robust tool and can be applied successfully regardless of experience in crop growing and education level when an in-depth introduction and training is provided. The use of a simple and clear layout of the assessment form is important for reliable wetness class assignments.

  20. Qualitative soil moisture assessment in semi-arid Africa: the role of experience and training on inter-rater reliability

    Science.gov (United States)

    Rinderer, M.; Komakech, H.; Müller, D.; Seibert, J.

    2015-03-01

    Soil and water management is particularly relevant in semi-arid regions to enhance agricultural productivity. During periods of water scarcity soil moisture differences are important indicators of the soil water deficit and are traditionally used for allocating water resources among farmers of a village community. Here we present a simple, inexpensive soil wetness classification scheme based on qualitative indicators which one can see or touch on the soil surface. It incorporates the local farmers' knowledge on the best soil moisture conditions for seeding and brick making in the semi-arid environment of the study site near Arusha, Tanzania. The scheme was tested twice in 2014 with farmers, students and experts (April: 40 persons, June: 25 persons) for inter-rater reliability, bias of individuals and functional relation between qualitative and quantitative soil moisture values. During the test in April farmers assigned the same wetness class in 46% of all cases while students and experts agreed in about 60% of all cases. Students who had been trained in how to apply the method gained higher inter-rater reliability than their colleagues with only a basic introduction. When repeating the test in June, participants were given improved instructions, organized in small sub-groups, which resulted in a higher inter-rater reliability among farmers. In 66% of all classifications farmers assigned the same wetness class and the spread of class assignments was smaller. This study demonstrates that a wetness classification scheme based on qualitative indicators is a robust tool and can be applied successfully regardless of experience in crop growing and education level when an in-depth introduction and training is provided. The use of a simple and clear layout of the assessment form is important for reliable wetness class assignments.

  1. Minimal information: an urgent need to assess the functional reliability of recombinant proteins used in biological experiments

    Directory of Open Access Journals (Sweden)

    de Marco Ario

    2008-07-01

    Full Text Available Abstract Structural characterization of proteins used in biological experiments is largely neglected. In most publications, the information available is totally insufficient to judge the functionality of the proteins used and, therefore, the significance of identified protein-protein interactions (was the interaction specific or due to unspecific binding of misfolded protein regions? or reliability of kinetic and thermodynamic data (how much protein was in its native form?. As a consequence, the results of single experiments might not only become questionable, but the whole reliability of systems biology, built on these fundaments, would be weakened. The introduction of Minimal Information concerning purified proteins to add as metadata to the main body of a manuscript would render straightforward the assessment of their functional and structural qualities and, consequently, of results obtained using these proteins. Furthermore, accepted standards for protein annotation would simplify data comparison and exchange. This article has been envisaged as a proposal for aggregating scientists who share the opinion that the scientific community needs a platform for Minimum Information for Protein Functionality Evaluation (MIPFE.

  2. Systematic impact of spent nuclear fuel on θ13 sensitivity at reactor neutrino experiment

    Institute of Scientific and Technical Information of China (English)

    AN Feng-Peng; TIAN Xin-Chun; ZHAN Liang; CAO Jun

    2009-01-01

    Reactor neutrino oscillation experiments, such as Daya Bay, Double Chooz and RENO are designed to determine the neutrino mixing angle θ13 with a sensitivity of 0.01--0.03 in sin2 2θ13 at 90% confidence level, an improvement over the current limit by more than one order of magnitude. The control of systematic uncertainties is critical to achieving the sin2 2θ13 sensitivity goal of these experiments. Antineutrinos emitted from spent nuclear fuel (SNF) would distort the soft part of energy spectrum and may introduce a non-negligible systematic uncertainty. In this article, a detailed calculation of SNF neutrinos is performed taking account of the operation of a typical reactor and the event rate in the detector is obtained. A further estimation shows that the event rate contribution of SNF neutrinos is less than 0.2% relative to the reactor neutrino signals. A global χ2 analysis shows that this uncertainty will degrade the θ13 sensitivity at a negligible level.

  3. The influence of spine surgeons' experience on the classification and intraobserver reliability of the novel AOSpine thoracolumbar spine injury classification system : an international study

    NARCIS (Netherlands)

    Sadiqi, Said; Oner, F. Cumhur; Dvorak, Marcel F.; Aarabi, Bizhan; Schroeder, Gregory D.; Vaccaro, Alexander R.

    2015-01-01

    Study Design. International validation study. Objective. To investigate the influence of the spine surgeons' level of experience on the intraobserver reliability of the novel AOSpine Thoracolumbar Spine Injury Classification system, and the appropriate classification according to this system. Summar

  4. Sea experiment of a survey AUV powered by a fuel cell system

    OpenAIRE

    Raugel, E; Rigaud, Vincent; Lakeman, C

    2010-01-01

    The use of autonomous underwater systems, such as AUV, is currently limited by their on board energy supply. The emergence of a higher capacity power source could be a breakthrough that extends these technologies field of application. Since 2005, within the PACSM project1, fuel cell systems for underwater applications were studied. HELION, an AREVA Renewable subsidiary, dedicated to both PEM fuel cell and electrolyze systems development, has designed a fuel cell system adapted for AUV energy ...

  5. Structure and Control Strategies of Fuel Cell Vehicle

    Institute of Scientific and Technical Information of China (English)

    宋建国; 张承宁; 孙逢春; 钟秋海

    2004-01-01

    The structure and kinds of the fuel cell vehicle (FCV) and the mathematical model of the fuel cell processor are discussed in detail. FCV includes many parts: the fuel cell thermal and water management, fuel supply, air supply and distribution, AC motor drive, main and auxiliary power management, and overall vehicle control system. So it requires different kinds of control strategies, such as the PID method, zero-pole method, optimal control method, fuzzy control and neural network control. Along with the progress of control method, the fuel cell vehicle's stability and reliability is up-and-up. Experiment results show FCV has high energy efficiency.

  6. Experience of Areva in fuel services for PWR and BWR; Experiencia de Areva en servicios de combustible para PWR y BWR

    Energy Technology Data Exchange (ETDEWEB)

    Morales, I.

    2015-07-01

    AREVA being an integrated supplier of fuel assemblies has included in its strategy to develop services and solutions to customers who desire to improve the performance and safety of their fuel. These services go beyond the simple 'after sale' services that can be expected from a fuel supplier: The portfolio of AREVA includes a wide variety of services, from scientific calculations to fuel handling services in a nuclear power plant. AREVA is committed to collaborate and to propose best-in-class solutions that really make the difference for the customer, based on 40 years of Fuel design and manufacturing experience. (Author)

  7. A within-sample investigation of test-retest reliability in choice experiment surveys with real economic incentives

    DEFF Research Database (Denmark)

    Mørkbak, Morten Raun; Olsen, Søren Bøye

    2015-01-01

    comparing choices, we also test for differences in preferences and error variance when a sample of respondents is given the exact same questionnaire twice, with a time lag of 2 weeks in between. Finally, we examine potential reasons and covariates explaining the level of agreement in choices across the 2......In this paper, we investigate the level of agreement between respondents' choices in identical choice sets in a test-retest choice experiment for a market good with real economic incentives, thus investigating whether the incentivised CE method can be reliable and stable over time. Besides...... difference in a choice task, the larger the probability that the respondent will choose the same alternative in the retest. Moreover, the results show that the longer time respondents take to answer the 12 choice sets in the retest, the lower the probability that the respondent will choose the same...

  8. Numerical analyses and experiment investigations of an annular micro gas turbine power system using fuels with low heating values

    Institute of Scientific and Technical Information of China (English)

    YANG; ChunHsiang; LEE; ChengChia; HSIAO; JenHao; CHEN; ChiunHsun

    2009-01-01

    This study investigates the effects of using fuels with low heating values on the performance of an annular micro gas turbine(MGT)experimentally and numerically.The MGT used in this study is MW-54, whose original fuel is liquid(Jet A1).Its fuel supply system is re-designed to use biogas fuel with low heating value(LHV).The purpose is to reduce the size of a biogas distributed power supply system and to enhance its popularization.This study assesses the practicability of using fuels with LHVs by using various mixing ratios of methane(CH4)and carbon dioxide(CO2).Prior to experiments,the corresponding simulations,aided by the commercial code CFD-ACE+,were carried out to investigate the cooling effect in a perforated combustion chamber and combustion behavior in an annular MGT when LHV gas was used.The main purposes are to confirm that there are no hot spots occurring in the liners and the exhaust temperatures of combustor are lower than 700°C when MGT is operated under different conditions.In experiments,fuel pressure and mass flow rate,turbine rotational speed,generator power output,and temperature distribution were measured to analyze MGT performance.Experimental results indicate that the presented MGT system operates successfully under each tested condition when the minimum heating value of the simulated fuel is approximately 50%of pure methane.The power output is around 170 W at 85000 r/min as 90%CH4 with 10%CO2 is used and 70 W at 60000 r/min as 70%CH4 with 30%CO2 is used.When a critical limit of 60%CH4 is used,the power output is extremely low. Furthermore,the best theoretical Brayton cycle efficiency for such MGT is calculated as 23%according to the experimental data while LHV fuel is used.Finally,the numerical results and experiment results reveal that MGT performance can be improved further and the possible solutions for performance im- provement are suggested for the future studies.

  9. Numerical analyses and experiment investigations of an annular micro gas turbine power system using fuels with low heating values

    Institute of Scientific and Technical Information of China (English)

    YANG ChunHsiang; LEE ChengChia; HSIAO JenHao; CHEN ChiunHsun

    2009-01-01

    This study investigates the effects of using fuels with low heating values on the performance of an annular micro gas turbine(MGT)experimentally and numerically.The MGT used in this study is MW-54,whose original fuel is liquid(Jet al).Its fuel supply system is re-designed to use biogas fuel with low heating value(LHV).The purpose is to reduce the size of a biogas distributed power supply system and to enhance its popularization.This study assesses the practicability of using fuels with LHVs by using various mixing ratios of methane(CH_4)and carbon dioxide(CO_2).Prior to experiments,the corresponding simulations,aided by the commercial code CFD-ACE+,were carried out to investigate the cooling effect in a perforated combustion chamber and combustion behavior in an annular MGT when LHV gas was used.The main purposes are to confirm that there are no hot spots occurring in the liners and the exhaust temperatures of combustor are lower than 700℃ when MGT is operated under different conditions,in experiments,fuel pressure and mass flow rate,turbine rotational speed,generator power output,and temperature distribution were measured to analyze MGT performance.Experimental results indicate that the presented MGT system operates successfully under each tested condition when the minimum heating value of the simulated fuel is approximately 50%of pure methane.The power output is around 170 W at 85000 r/min as 90%CH_4 with 10%CO_2 is used and 70 W at 60000 r/min as 70%CH_4 with 30%CO_2 is used.When a critical limit of 60%CH_4 is used,the power output is extremely low.Furthermore,the best theoretical Brayton cycle efficiency for such MGT is calculated as 23%according to the experimental data while LHV fuel is used.Finally,the numerical results and experiment results reveal that MGT performance can be improved further and the possible solutions for performance improvement are suggested for the future studies.

  10. Fuel cell vehicles at general motors

    Energy Technology Data Exchange (ETDEWEB)

    Helmolt, R. von [GM Fuel Cell Activities, Adam Opel AG, IPC 81-90, D-65423 Ruesselsheim (Germany)

    2004-12-01

    An overview of GM/Opel's hydrogen fuel cell vehicles is presented. Three vehicle generations have been put into operation within the past four years, and valuable practical experience has been gained. GM/Opel's development targets are today shifting from pure performance optimisation to more varied aims, including reliability and durability considerations. Increased attention is also being paid to the fuel storage factor, which is a major issue for hydrogen cars. (Abstract Copyright [2004], Wiley Periodicals, Inc.)

  11. Licensing of spent fuel dry storage and consolidated rod storage: A Review of Issues and Experiences

    Energy Technology Data Exchange (ETDEWEB)

    Bailey, W.J.

    1990-02-01

    The results of this study, performed by Pacific Northwest Laboratory (PNL) and sponsored by the US Department of Energy (DOE), respond to the nuclear industry's recommendation that a report be prepared that collects and describes the licensing issues (and their resolutions) that confront a new applicant requesting approval from the US Nuclear Regulatory Commission (NRC) for dry storage of spent fuel or for large-scale storage of consolidated spent fuel rods in pools. The issues are identified in comments, questions, and requests from the NRC during its review of applicants' submittals. Included in the report are discussions of (1) the 18 topical reports on cask and module designs for dry storage fuel that have been submitted to the NRC, (2) the three license applications for dry storage of spent fuel at independent spent fuel storage installations (ISFSIs) that have been submitted to the NRC, and (3) the three applications (one of which was later withdrawn) for large-scale storage of consolidated fuel rods in existing spent fuel storage pools at reactors that were submitted tot he NRC. For each of the applications submitted, examples of some of the issues (and suggestions for their resolutions) are described. The issues and their resolutions are also covered in detail in an example in each of the three subject areas: (1) the application for the CASTOR V/21 dry spent fuel storage cask, (2) the application for the ISFSI for dry storage of spent fuel at Surry, and (3) the application for full-scale wet storage of consolidated spent fuel at Millstone-2. The conclusions in the report include examples of major issues that applicants have encountered. Recommendations for future applicants to follow are listed. 401 refs., 26 tabs.

  12. A proposal of benchmark calculation on reactor physics for metallic fueled and MOX fueled LMFBR based upon mack-up experiment at FCA

    Energy Technology Data Exchange (ETDEWEB)

    Oigawa, Hiroyuki; Iijima, Susumu; Sakurai, Takeshi; Okajima, Shigeaki; Andoh, Masaki; Nemoto, Tatsuo; Kato, Yuichi; Osugi, Toshitaka [Dept. of Nuclear Energy System, Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan)

    2000-02-01

    In order to assess the validity of the cross section library for fast reactor physics, a set of benchmark calculation is proposed. The benchmark calculation is based upon mock-up experiments at three FCA cores with various compositions of central test regions, two of which were mock-ups of metallic fueled LMFBR's, and the other was a mock-up of a mixed oxide fueled LMFBR. One of the metallic cores included enriched uranium in the test region, while the others did not. Physics parameters to be calculated are criticality, reaction rate ratios, plutonium and B{sub 4}C sample worth, sodium void reactivity worth, and Doppler reactivity worth of {sup 238}U. Homogenized atomic number densities and various correction factors are given so that anyone can easily perform diffusion calculation in two-dimensional RZ-model and compare the results with the experiments. The validity of the correction factors are proved by changing the calculation method and used nuclear data file. (author)

  13. Effect of Fuel Wobbe Number on Pollutant Emissions from Advanced Technology Residential Water Heaters: Results of Controlled Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Rapp, Vi H.; Singer, Brett C.

    2014-03-01

    The research summarized in this report is part of a larger effort to evaluate the potential air quality impacts of using liquefied natural gas in California. A difference of potential importance between many liquefied natural gas blends and the natural gas blends that have been distributed in California in recent years is the higher Wobbe number of liquefied natural gas. Wobbe number is a measure of the energy delivery rate for appliances that use orifice- or pressure-based fuel metering. The effect of Wobbe number on pollutant emissions from residential water heaters was evaluated in controlled experiments. Experiments were conducted on eight storage water heaters, including five with “ultra low-NO{sub X}” burners, and four on-demand (tankless) water heaters, all of which featured ultra low-NO{sub X} burners. Pollutant emissions were quantified as air-free concentrations in the appliance flue and fuel-based emission factors in units of nanogram of pollutant emitter per joule of fuel energy consumed. Emissions were measured for carbon monoxide (CO), nitrogen oxides (NO{sub X}), nitrogen oxide (NO), formaldehyde and acetaldehyde as the water heaters were operated through defined operating cycles using fuels with varying Wobbe number. The reference fuel was Northern California line gas with Wobbe number ranging from 1344 to 1365. Test fuels had Wobbe numbers of 1360, 1390 and 1420. The most prominent finding was an increase in NO{sub X} emissions with increasing Wobbe number: all five of the ultra low-NO{sub X} storage water heaters and two of the four ultra low-NO{sub X} on-demand water heaters had statistically discernible (p<0.10) increases in NO{sub X} with fuel Wobbe number. The largest percentage increases occurred for the ultra low-NO{sub X} water heaters. There was a discernible change in CO emissions with Wobbe number for all four of the on-demand devices tested. The on-demand water heater with the highest CO emissions also had the largest CO increase

  14. Assessment of RANS Based CFD Methodology using JAEA Experiment with a Wire-wrapped 127-pin Fuel Assembly

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, J. H.; Yoo, J.; Lee, K. L.; Ha, K. S. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    In this paper, we assess the RANS based CFD methodology with JAEA experimental data. The JAEA experiment study with the 127-pin wire-wrapped fuel assembly was implemented using water for validating pressure drop formulas in ASFRE code. Complicated and vortical flow phenomena in the wire-wrapped fuel bundles were captured by vortex structure identification technique based on the critical point theory. The SFR system is one of the nuclear reactors in which a recycling of transuranics (TRUs) by reusing spent nuclear fuel sustains the fission chain reaction. This situation strongly motivated the Korea Atomic Energy Research Institute (KAERI) to start a prototype Gen-4 Sodium-cooled Fast Reactor (PGSFR) design project under the national nuclear R and D program. Generally, the SFR system has a tight package of the fuel bundle and a high power density. The sodium material has a high thermal conductivity and boiling temperature than the water. That can make core design to be more compact than Light Water Reactor (LWR) through narrower sub-channels. The fuel assembly of the SFR system consists of long and thin wire-wrapped fuel bundles and a hexagonal duct, in which wire-wrapped fuel bundles in the hexagonal tube has triangular loose array. The main purpose of a wire spacer is to avoid collisions between adjacent rods. Furthermore, a wire spacer can mitigate a vortex induced vibration, and enhance convective heat transfer due to the secondary flow by helical type wire spacers. Most of numerical studies in the nuclear fields was widely conducted based on the simplified sub-channel analysis codes such as COBRA (Rowe), SABRE (Macdougall and Lillington), ASFRE (Ninokata), and MATRA-LMR (Kim et al.). The relationship between complex flow phenomena and helically wrapped-wire spacers will be discussed. The RANS based CFD methodology is evaluated with JAEA experimental data of the 127-pin wirewrapped fuel assembly. Complicated and vortical flow phenomena in the wire-wrapped fuel

  15. Validity and Reliability of a New Measure of Nursing Experience With Unintended Consequences of Electronic Health Records.

    Science.gov (United States)

    Gephart, Sheila M; Bristol, Alycia A; Dye, Judy L; Finley, Brooke A; Carrington, Jane M

    2016-10-01

    Unintended consequences of electronic health records represent undesired effects on individuals or systems, which may contradict initial goals and impact patient care. The purpose of this study was to determine the extent to which a new quantitative measure called the Carrington-Gephart Unintended Consequences of Electronic Health Record Questionnaire (CG-UCE-Q) was valid and reliable. Then, it was used to describe acute care nurses' experience with unintended consequences of electronic health records and relate them to the professional practice environment. Acceptable content validity was achieved for two rounds of surveys with nursing informatics experts (n = 5). Then, acute care nurses (n = 144) were recruited locally and nationally to complete the survey and describe the frequency with which they encounter unintended consequences in daily work. Principal component analysis with oblique rotation was applied to evaluate construct validity. Correlational analysis with measures of the professional practice environment and workarounds was used to evaluate convergent validity. Test-retest reliability was measured in the local sample (N = 68). Explanation for 63% of the variance across six subscales (patient safety, system design, workload issues, workarounds, technology barriers, and sociotechnical impact) supported construct validity. Relationships were significant between subscales for electronic health record-related threats to patient safety and low autonomy/leadership (P < .01), poor communication about patients (P < .01), and low control over practice (P < .01). The most frequent sources of unintended consequences were increased workload, interruptions that shifted tasks from the computer, altered workflow, and the need to duplicate data entry. Convergent validity of the CG-UCE-Q was moderately supported with both the context and processes of workarounds with strong relationships identified for when nurses perceived a block and altered process to work around it

  16. PIE of the second fuel rod from the LOCA experiment (IFA-650.2)

    Energy Technology Data Exchange (ETDEWEB)

    Oberlaender, B.C.; Jenssen, H.K.; Espeland, M.; Solum, N.O.

    2005-07-01

    The LOCA experiment on the second rod (IFA-650.2) a fresh, low-tin Zr-4, pressurised PWR rod was carried out in May 2004. The main objective was to produce ballooning, to determine the time to burst and to assess the material oxidation and hydriding kinetics. The rod pressure at hot conditions and peak PCT were 70 bar and 1050 C, respectively. To document the effect of the LOCA testing on the cladding, rod 2 was subjected in PIE to visual inspection, profilometry and metallography. On visual inspection the clad shows a typical balloon. In the region of max ballooning the clad shows a 35 mm long, < 20 mm burst opening. In the balloon region the outer clad diameter increased by <35% and locally the wall thickness reduction is >55%. The entire rod is covered with a black oxide layer. Below and above the split opening the continuous oxide layer was 40 to 50mum both on water and fuel side of the clad. At the locations of the upper and lower cladding thermocouples the oxide thickness was in the range 24-27 mum. Widmanstaetten structure is seen in the bulk of the clad and confirms the high temperature experienced. A some 40mum wide, hard and brittle zone with oxygen rich globular alpha-grains is found both at the outer and the inner edge of the clad in the balloon region. The zone is widest near the axial split (crack). In the clad few, arbitrary oriented hydride platelets are observed in the balloon area. (Author)

  17. GEN IV: Carbide Fuel Elaboration for the 'Futurix Concepts' experiment

    Energy Technology Data Exchange (ETDEWEB)

    Vaudez, Stephane; Riglet-Martial, Chantal; Paret, Laurent; Abonneau, Eric [Commissariat a l' Energie Atomique (C.E.A.), Direction de l' Energie Nucleaire, Centre d' Etudes de Cadarache, 13108 Saint Paul lez Durance Cedex (France)

    2008-07-01

    In order to collect information on the behaviour of the future GFR (Gas Fast Reactor) fuel under fast neutron irradiation, an experimental irradiation program, called 'Futurix-concepts' has been launched at the CEA. The considered concept is a composite material made of a fissile fuel embedded in an inert ceramic matrix. Fissile fuel pellets are made of UPuN or UPuC while ceramics are SiC for the carbide fuel and TiN for the nitride fuel. This paper focuses on the description of the carbide composite fabrication. The UPuC pellets are manufactured using a metallurgical powder process. Fabrication and handling of the fuels are carried out in glove boxes under a nitrogen atmosphere. Carbide fuel is synthesized by carbo-thermic reduction under vacuum of a mixture of actinide oxide and graphitic carbon up to 1550 deg. C. After ball milling, the UPuC powder is pressed to create hexagonal or spherical compacts. They are then sintered up to 1750 deg. C in order to obtain a density of 85 % of the theoretical one. The sintered pellets are inserted into an inert and tight capsule of SiC. In order to control the gap between the fuel and the matrix precisely, the pellets are abraded. The inert matrix is then filled with the pellets and the whole system is sealed by a BRASiC{sup R} process at high temperature under a helium atmosphere. Fabrication of the sample to be irradiated was done in 2006 and the irradiation began in May 2007 in the Phenix reactor. This presentation will detail and discuss the results obtained during this fabrication phase. (authors)

  18. Using Coupled Mesoscale Experiments and Simulations to Investigate High Burn-Up Oxide Fuel Thermal Conductivity

    Science.gov (United States)

    Teague, Melissa C.; Fromm, Bradley S.; Tonks, Michael R.; Field, David P.

    2014-12-01

    Nuclear energy is a mature technology with a small carbon footprint. However, work is needed to make current reactor technology more accident tolerant and to allow reactor fuel to be burned in a reactor for longer periods of time. Optimizing the reactor fuel performance is essentially a materials science problem. The current understanding of fuel microstructure have been limited by the difficulty in studying the structure and chemistry of irradiated fuel samples at the mesoscale. Here, we take advantage of recent advances in experimental capabilities to characterize the microstructure in 3D of irradiated mixed oxide (MOX) fuel taken from two radial positions in the fuel pellet. We also reconstruct these microstructures using Idaho National Laboratory's MARMOT code and calculate the impact of microstructure heterogeneities on the effective thermal conductivity using mesoscale heat conduction simulations. The thermal conductivities of both samples are higher than the bulk MOX thermal conductivity because of the formation of metallic precipitates and because we do not currently consider phonon scattering due to defects smaller than the experimental resolution. We also used the results to investigate the accuracy of simple thermal conductivity approximations and equations to convert 2D thermal conductivities to 3D. It was found that these approximations struggle to predict the complex thermal transport interactions between metal precipitates and voids.

  19. Experiment and Simulation of Medium-Duty Tactical Truck for Fuel Economy Improvement

    Directory of Open Access Journals (Sweden)

    Allen M. Quail

    2011-02-01

    Full Text Available Fuel economy improvement on medium-duty tactical truck has and continues to be a significant initiative for the U.S. Army. The focus of this study is the investigation of Automated Manual Transmissions (AMT and mild hybridization powertrain that have potential to improve the fuel economy of the 2.5-ton cargo trucks. The current platform uses a seven-speed automatic transmission. This study utilized a combination of on-road experimental vehicle data and analytical vehicle modeling and simulation. This paper presents the results of (1 establishment of a validated, high fidelity baseline analytical vehicle model, (2 modeling and simulation of two AMTs and their control strategy, (3 optimization of transmissions shift schedules, and (4 modeling and simulation of engine idle stop/start and Belt-Integrated-Starter-Generator (B-ISG systems to improve the fuel economy. The fuel economy discrepancy between experimental average and the baseline simulation result was 2.87%. The simulation results indicated a 14.5% and 12.2% fuel economy improvement for the 10-speed and 12-speed AMT respectively. A stop/start system followed by a B-ISG mild hybrid system incorporating regenerative braking was estimated to improve fuel economy 3.39% and 10.2% respectively.

  20. Areva new fuel designs; increased reliability, operating margins and operating efficiency; Nuevos disenos de combustible Areva: aumento de fiabilidad, margenes operativos y eficiencia del funcionamiento

    Energy Technology Data Exchange (ETDEWEB)

    Mollard, P.; Vollmer, N.; Curca-Tivig, F.; Cole, S.; Louf, H. P.

    2015-07-01

    AREVA is continuously working on the improvement of the fuel design to address immediate and future needs of the utilities. This improvement process regularly leads to incremental changes but also to breakthrough changes addressing the next needs of the market. Since a few years now, the improvements of the fuel design and licensing benefit from the improvement and upgrade in codes and methods and computational capabilities. Changes in design are sustained by these more powerful and phenomenological tools which secure and fasten the fuel design optimization and its implementation. (Author)

  1. Practical experiences with animal fat as added fuel in the Ingolstadt power station; Praktische Erfahrungen bei der versuchsweisen Mitverbrennung von Tierfett im Kraftwerk Ingolstadt

    Energy Technology Data Exchange (ETDEWEB)

    Gerischer, C.N. [E.ON Kraftwerke GmbH, Kraftwerksgruppe Ingolstadt/Irsching, Grossmehring (Germany)

    2004-07-01

    In 2001 the market was overflowing with animal fat due to the discussion about the bovine spongiform encephalopathy disease. One solution was the use as additional fuel in power plants. The fundamental technical requirements existed in Ingolstadt power station. Economical considerations led to the decision to test animal fat as added fuel. The main experiences are presented and discussed. (orig.)

  2. Recent developments in the production of liquid fuels via catalytic conversion of microalgae: experiments and simulations

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Fan; Wang, Pin; Duan, Yuhua; Link, Dirk; Morreale, Bryan

    2012-01-01

    Due to continuing high demand, depletion of non-renewable resources and increasing concerns about climate change, the use of fossil fuel-derived transportation fuels faces relentless challenges both from a world markets and an environmental perspective. The production of renewable transportation fuel from microalgae continues to attract much attention because of its potential for fast growth rates, high oil content, ability to grow in unconventional scenarios, and inherent carbon neutrality. Moreover, the use of microalgae would minimize ‘‘food versus fuel’’ concerns associated with several biomass strategies, as microalgae do not compete with food crops in the food chain. This paper reviews the progress of recent research on the production of transportation fuels via homogeneous and heterogeneous catalytic conversions of microalgae. This review also describes the development of tools that may allow for a more fundamental understanding of catalyst selection and conversion processes using computational modelling. The catalytic conversion reaction pathways that have been investigated are fully discussed based on both experimental and theoretical approaches. Finally, this work makes several projections for the potential of various thermocatalytic pathways to produce alternative transportation fuels from algae, and identifies key areas where the authors feel that computational modelling should be directed to elucidate key information to optimize the process.

  3. The Outlook for Low-Grade Fuels in Tomsk Region: Research Experience at Tomsk Polytechnic University

    Directory of Open Access Journals (Sweden)

    Khaustov Sergei A.

    2016-01-01

    Full Text Available The urgency of the discussed issue is caused by the need to substitute in the regional fuel-energy balances imported energy resources with local low-grade fuels. The main aim of the study is to estimate thermal properties of local fuels in Tomsk region and evaluate its energy use viability. The methods used in the study were based standard GOST 52911-2008, 11022-95 and 6382-2001, by means of a bomb calorimeter ABK-1 and Vario micro cube analyzer. The mineral ash of researched fuels was studied agreeing with GOST 10538-87. The results state the fact that discussed low-grade fuels of Tomsk region in the unprepared form are not able to replace imported coal in regional energy balance, because of the high moisture and ash content values. A promosing direction of a low-temperature fue processing is a catalytic converter, which allows receiving hydrogen-enriched syngas from the initial solid raw.

  4. Experience of Areva in the design of MOX and ERU fuel; Experiencia de Areva en el diseno de combustible MOX y ERU

    Energy Technology Data Exchange (ETDEWEB)

    Porsch, D.; Lorenzo, D. de

    2011-07-01

    In the sustainability concept being applied to an energy source, it is implied its capacity to produce or have available enough fuel for its continuous operation for a sufficiently long time period. in the case of fission nuclear energy, fuel recycling is crucial to achieve this objective. Fortunately, the recycling technologies developed in a commercial scale by Ar eva are sufficiently proved and MOX/ERU fuel assemblies have been used for decades in some Europe countries mainly and others in the world. This article aims to show the cumulated experience for these types of fuels and the results of its use in commercial Light Water Reactors (LWRs). (Author) 3 refs.

  5. Direct Experiments on the Ocean Disposal of Fossil Fuel CO2

    Energy Technology Data Exchange (ETDEWEB)

    Barry, James, P.

    2010-05-26

    Funding from DoE grant # FG0204-ER63721, Direct Experiments on the Ocean Disposal of Fossil Fuel CO2, supposed several postdoctoral fellows and research activities at MBARI related to ocean CO2 disposal and the biological consequences of high ocean CO2 levels on marine organisms. Postdocs supported on the project included Brad Seibel, now an associate professor at the University of Rhode Island, Jeff Drazen, now an associate professor at the University of Hawaii, and Eric Pane, who continues as a research associate at MBARI. Thus, the project contributed significantly to the professional development of young scientists. In addition, we made significant progress in several research areas. We continued several deep-sea CO2 release experiments using support from DoE and MBARI, along with several collaborators. These CO2 release studies had the goal of broadening our understanding of the effects of high ocean CO2 levels on deep sea animals in the vicinity of potential release sites for direct deep-ocean carbon dioxide sequestration. Using MBARI ships and ROVs, we performed these experiments at depths of 3000 to 3600 m, where liquid CO2 is heavier than seawater. CO2 was released into small pools (sections of PVC pipe) on the seabed, where it dissolved and drifted downstream, bathing any caged animals and sediments in a CO2-rich, low-pH plume. We assessed the survival of organisms nearby. Several publications arose from these studies (Barry et al. 2004, 2005; Carman et al. 2004; Thistle et al. 2005, 2006, 2007; Fleeger et al. 2006, 2010; Barry and Drazen 2007; Bernhard et al. 2009; Sedlacek et al. 2009; Ricketts et al. in press; Barry et al, in revision) concerning the sensitivity of animals to low pH waters. Using funds from DoE and MBARI, we designed and fabricated a hyperbaric trap-respirometer to study metabolic rates of deep-sea fishes under high CO2 conditions (Drazen et al, 2005), as well as a gas-control aquarium system to support laboratory studies of the

  6. Fuel Cells

    Science.gov (United States)

    Hawkins, M. D.

    1973-01-01

    Discusses the theories, construction, operation, types, and advantages of fuel cells developed by the American space programs. Indicates that the cell is an ideal small-scale power source characterized by its compactness, high efficiency, reliability, and freedom from polluting fumes. (CC)

  7. Influence of the experience of the reader on reliability of joint space width measurement. A cross-sectional multiple reading study in hip osteoarthritis.

    Science.gov (United States)

    Ornetti, Paul; Maillefert, Jean-Francis; Paternotte, Simon; Dougados, Maxime; Gossec, Laure

    2011-10-01

    The objectives were to evaluate improvement in reliability of joint space width (JSW) measurements, according to the previous experience of the readers in hip osteoarthritis (OA). Fifty radiographs in hip OA patients from a randomized controlled trial (ECHODIAH) were read 12 times by two readers with different levels of experience in radiographic interpretation. Intra-reader reliability and inter-reader reliability were assessed through calculation of the smallest detectable difference (SDD) and the intra-class correlation coefficient (ICC). Intra-reader reliability: for the experienced reader, no significant change in SDD was observed with repeated JSW measurements. For the junior reader, the SDD decreased significantly from 0.90 mm to 0.65 mm (P=0.002). A plateau of SDD was reached after reading 200 to 300 radiographs, with a value close to the mean SDD of the experienced reader (0.67 mm). ICCs were high (>0.88) for both the senior and the junior readers. Inter-reader reliability: no improvement in inter-reader reliability was noted with repeated measurements of JSW (SDD=0.81 mm). However, no additional training sessions were performed. ICCs were high (>0.85). This study indicated for the first time a learning curve in analyzing JSW in hip OA for an inexperienced reader. After analyzing 200 to 300 radiographs, the junior reader reached an intra-reader reliability similar to the experienced reader. Moreover, the information brought by the ICC was not sufficient, suggesting that the SDD should be systematically reported in studies evaluating OA radiographic progression, on top of the ICC, to help in interpreting the JSW reliability. Copyright © 2010 Société française de rhumatologie. Published by Elsevier SAS. All rights reserved.

  8. Hot Experiment on Fission Gas Release Behavior from Voloxidation Process using Spent Fuel

    Energy Technology Data Exchange (ETDEWEB)

    Park, Geun Il; Park, J. J.; Jung, I. H.; Shin, J. M.; Cho, K. H.; Yang, M. S.; Song, K. C

    2007-08-15

    Quantitative analysis of the fission gas release characteristics during the voloxidation and OREOX processes of spent PWR fuel was carried out by spent PWR fuel in a hot-cell of the DFDF. The release characteristics of {sup 85}Kr and {sup 14}C fission gases during voloxidation process at 500 .deg. C is closely linked to the degree of conversion efficiency of UO{sub 2} to U{sub 3}O{sub 8} powder, and it can be interpreted that the release from grain-boundary would be dominated during this step. Volatile fission gases of {sup 14}C and {sup 85}Kr were released to near completion during the OREOX process. Both the {sup 14}C and {sup 85}Kr have similar release characteristics under the voloxidation and OREOX process conditions. A higher burn-up spent fuel showed a higher release fraction than that of a low burn-up fuel during the voloxidation step at 500 .deg. C. It was also observed that the release fraction of semi-volatile Cs was about 16% during a reduction at 1,000 .deg. C of the oxidized powder, but over 90% during the voloxidation at 1,250 .deg. C.

  9. Hydrogen Storage Experiments for an Undergraduate Laboratory Course--Clean Energy: Hydrogen/Fuel Cells

    Science.gov (United States)

    Bailey, Alla; Andrews, Lisa; Khot, Ameya; Rubin, Lea; Young, Jun; Allston, Thomas D.; Takacs, Gerald A.

    2015-01-01

    Global interest in both renewable energies and reduction in emission levels has placed increasing attention on hydrogen-based fuel cells that avoid harm to the environment by releasing only water as a byproduct. Therefore, there is a critical need for education and workforce development in clean energy technologies. A new undergraduate laboratory…

  10. Field test corrosion experiments in Denmark with biomass fuels Part I Straw firing

    DEFF Research Database (Denmark)

    Montgomery, Melanie; Karlsson, A; Larsen, OH

    2002-01-01

    In Denmark, straw and other types of biomass are used for generating energy in power plants. Straw has the advantage that it is a "carbon dioxide neutral fuel" and therefore environmentally acceptable. Straw combustion is associated with corrosion problems which are not encountered in coal...

  11. Hydrogen Storage Experiments for an Undergraduate Laboratory Course--Clean Energy: Hydrogen/Fuel Cells

    Science.gov (United States)

    Bailey, Alla; Andrews, Lisa; Khot, Ameya; Rubin, Lea; Young, Jun; Allston, Thomas D.; Takacs, Gerald A.

    2015-01-01

    Global interest in both renewable energies and reduction in emission levels has placed increasing attention on hydrogen-based fuel cells that avoid harm to the environment by releasing only water as a byproduct. Therefore, there is a critical need for education and workforce development in clean energy technologies. A new undergraduate laboratory…

  12. Field test corrosion experiments in Denmark with biomass fuels Part I Straw firing

    DEFF Research Database (Denmark)

    Montgomery, Melanie; Karlsson, A; Larsen, OH

    2002-01-01

    In Denmark, straw and other types of biomass are used for generating energy in power plants. Straw has the advantage that it is a "carbon dioxide neutral fuel" and therefore environmentally acceptable. Straw combustion is associated with corrosion problems which are not encountered in coal...

  13. Multiphase Simulations and Design of Validation Experiments for Proton Exchange Membrane Fuel Cells

    DEFF Research Database (Denmark)

    Berning, Torsten

    2013-01-01

    Proton exchange membrane fuel cells directly convert into electricity the chemical energy of hydrogen and oxygen from air. The by-products are just water and waste heat. Depending on the operating conditions the water may be in the liquid or gas phase, and liquid water can hence plug the porous m...

  14. Traction-transport components integrated in fuel cells; running constraints, lifetime, reliability; Les composants traction-transport integres dans les systemes PAC; contraintes de mission, duree de vie, fiabilite

    Energy Technology Data Exchange (ETDEWEB)

    Coquery, G. [Institut National de Recherche sur les transports et leur Securite, INRETS LTN, 94 - Arcueil (France)

    2000-07-01

    The future systems 'fuel cell' on-board in transport vehicles 'SPACT' will be optimized by the control of energy fluxes: of generation, of traction, of recovery to braking and of stored energy. The aim is to reach the level required for the user in terms of reliability, availability, maintainability and safety for a transport vehicle answering to economical and environmental criteria. Despite the obvious necessity of the research and industrialization studies on the 'SPACT' technologies, the current technological advances on the integration of the electronics for traction and the energy storage by super-capacitors and batteries are also determining factors for the industrialization of these hybrid systems. The proposed study presents the constraints of the transport applications, lifetime and reliability, the technologies of the power integration and the future developments of these new components for the transport sector. (O.M.)

  15. Experience with the transport and storage casks CASTOR (registered) MTR 2 for spent nuclear fuel assemblies from research reactors

    Energy Technology Data Exchange (ETDEWEB)

    Jack, Allen; Rettenbacher, Katharina; Skrzyppek, Juergen [GNS Gesellschaft fuer Nuklear-Service mbH, Essen (Germany)

    2011-07-01

    The CASTOR (registered) MTR 2 cask was designed and manufactured by the company GNS during the 1990's for the transport and interim storage of spent nuclear fuel assemblies from various types of research reactors. Casks of this type have been used at the VKTA Research Centre in Rossendorf near Dresden, Germany as well as at the European Commission's Joint Research Centre at Petten and at the HOR reactor at Delft in the Netherlands. A total of 24 units have been used for the functions of transport and storage with various spent fuel types (VVER, HFR-HEU, and HOR-HEU) for more than ten years now. This type of packaging for radioactive material is a member of the CASTOR (registered) family of spent nuclear fuel casks used worldwide. Over 1000 units are loaded and in storage in Europe, Asia, Africa and North America. This paper presents the experience from the use of the casks for transport and storage in the past, as well as the prospects for the future. (author)

  16. Essential Data and Techniques for Conducting Microbial Fuel Cell and other Types of Bioelectrochemical System Experiments

    KAUST Repository

    Logan, Bruce E.

    2012-04-19

    Microbial fuel cells (MFCs) and other bioelectrochemical systems are new technologies that require expertise in a variety of technical areas, ranging from electrochemistry to biological wastewater treatment. There are certain data and critical information that should be included in every MFC study, such as specific surface area of the electrodes, solution conductivity, and power densities normalized to electrode surface area and volumes. Electrochemical techniques such as linear sweep voltammetry can be used to understand the performance of the MFC, but extremely slow scans are required for these biological systems compared to more traditional fuel cells. In this Minireview, the critical information needed for MFC studies is provided with examples of how results can be better conveyed through a full description of materials, the use of proper controls, and inclusion of a more complete electrochemical analysis. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Fuel flexible fuel injector

    Science.gov (United States)

    Tuthill, Richard S; Davis, Dustin W; Dai, Zhongtao

    2015-02-03

    A disclosed fuel injector provides mixing of fuel with airflow by surrounding a swirled fuel flow with first and second swirled airflows that ensures mixing prior to or upon entering the combustion chamber. Fuel tubes produce a central fuel flow along with a central airflow through a plurality of openings to generate the high velocity fuel/air mixture along the axis of the fuel injector in addition to the swirled fuel/air mixture.

  18. Experiment Safety Assurance Package for Mixed Oxide Fuel Irradiation in an Average Power Position (I-24) in the Advanced Test Reactor

    Energy Technology Data Exchange (ETDEWEB)

    J. M . Ryskamp; R. C. Howard; R. C. Pedersen; S. T. Khericha

    1998-10-01

    The Fissile Material Disposition Program Light Water Reactor Mixed Oxide Fuel Irradiation Test Project Plan details a series of test irradiations designed to investigate the use of weapons-grade plutonium in MOX fuel for light water reactors (LWR) (Cowell 1996a, Cowell 1997a, Thoms 1997a). Commercial MOX fuel has been successfully used in overseas reactors for many years; however, weapons-derived test fuel contains small amounts of gallium (about 2 parts per million). A concern exists that the gallium may migrate out of the fuel and into the clad, inducing embrittlement. For preliminary out-of-pile experiments, Wilson (1997) states that intermetallic compound formation is the principal interaction mechanism between zircaloy cladding and gallium. This interaction is very limited by the low mass of gallium, so problems are not expected with the zircaloy cladding, but an in-pile experiment is needed to confirm the out-of-pile experiments. Ryskamp (1998) provides an overview of this experiment and its documentation. The purpose of this Experiment Safety Assurance Package (ESAP) is to demonstrate the safe irradiation and handling of the mixed uranium and plutonium oxide (MOX) Fuel Average Power Test (APT) experiment as required by Advanced Test Reactor (ATR) Technical Safety Requirement (TSR) 3.9.1 (LMITCO 1998). This ESAP addresses the specific operation of the MOX Fuel APT experiment with respect to the operating envelope for irradiation established by the Upgraded Final Safety Analysis Report (UFSAR) Lockheed Martin Idaho Technologies Company (LMITCO 1997a). Experiment handling activities are discussed herein.

  19. Nitrogen isotopic evidence for a shift from nitrate- to diazotroph-fueled export production in VAHINE mesocosm experiments

    Directory of Open Access Journals (Sweden)

    A. N. Knapp

    2015-12-01

    Full Text Available In a shallow, coastal lagoon off the southwest coast of New Caledonia, large-volume (~ 50 m3 mesocosm experiments were undertaken to track the fate of newly fixed nitrogen (N. The mesocosms were intentionally fertilized with 0.8 μM dissolved inorganic phosphorus (DIP to stimulate diazotrophy. N isotopic evidence indicates that the dominant source of N fueling export production shifted from subsurface nitrate (NO3− assimilated prior to the start of the 23 day experiments to N2 fixation by the end of the experiments. While the δ15N of the sinking particulate N (PNsink flux changed during the experiments, the δ15N of the suspended PN (PNsusp and dissolved organic N (DON pools did not. This is consistent with previous observations that the δ15N of surface ocean N pools is less responsive than that of PNsink to changes in the dominant source of new N to surface waters. In spite of the absence of detectable NO3− in the mesocosms, the δ15N of PNsink indicated that NO3− continued to fuel a significant fraction of export production (20 to 60 % throughout the 23 day experiments, with N2 fixation dominating export after about two weeks. The low rates of primary productivity and export production during the first 14 days were primarily supported by NO3−, and phytoplankton abundance data suggest that export was driven by large diatoms sinking out of surface waters. Concurrent molecular and taxonomic studies indicate that the diazotroph community was dominated by diatom-diazotroph assemblages (DDAs at this time. However, these DDAs represented a minor fraction (2 fixation; they were thus not important for driving export production, either directly or indirectly. The unicellular cyanobacterial diazotroph, a Cyanothece-like UCYN-C, proliferated during the last phase of the experiments when N2 fixation, primary production, and the flux of PNsink increased significantly, and δ15N budgets reflected a predominantly diazotrophic source of N fueling

  20. The co-evolution of alternative fuel infrastructure and vehicles. A study of the experience of Argentina with compressed natural gas

    Energy Technology Data Exchange (ETDEWEB)

    Collantes, Gustavo [Renergh Consulting and Department of Commerce, State of Washington, 2001 6th Ave, Suite 2600, Seattle, WA 98121 (United States); Melaina, Marc W. [National Renewable Energy Laboratory (United States)

    2011-02-15

    In a quest for strategic and environmental benefits, the developed countries have been trying for many years to increase the share of alternative fuels in their transportation fuel mixes. They have met very little success though. In this paper, we examine the experience of Argentina with compressed natural gas. We conducted interviews with a wide range of stakeholders and analyzed econometrically data collected in Argentina to investigate the factors, economic, political, and others that determined the high rate of adoption of this fuel. A central objective of this research was to identify lessons that could be useful to developed countries in their efforts to deploy alternative fuel vehicles. We find that fuel price regulation was a significant determinant of the adoption of compressed natural gas, while, contrary to expectations, government financing of refueling infrastructure was minimal. (author)

  1. Compositional evolution of the emplaced fuel source in the vadose zone field experiment at airbase Vaerlose, Denmark

    DEFF Research Database (Denmark)

    Broholm, Mette Martina; Christophersen, Mette; Maier, U.;

    2005-01-01

    A field experiment was performed in a sandy vadose zone, studying the fate of an emplaced fuel-NAPL source, composed of 13 hydrocarbons and a tracer. The UNIFAC model was used to test the nonideal behavior of the source, and the numerical model MIN3P was used for assessing the effect of biodegrad......A field experiment was performed in a sandy vadose zone, studying the fate of an emplaced fuel-NAPL source, composed of 13 hydrocarbons and a tracer. The UNIFAC model was used to test the nonideal behavior of the source, and the numerical model MIN3P was used for assessing the effect...... of biodegradation on source evolution. The diffusive loss to the surrounding vadose zone and the atmosphere created temporary gradients in mole fractions of the individual compounds within the source NAPL. The evolution of the source composition corresponded in general with expectations based on Raoult's Law....... Positive deviations were calculated for the aromatic compounds. The effect of biodegradation on source depletion, evaluated by numerical modeling, was greater for the aromatic as compared to the aliphatic compounds. Hence, the faster depletion of the aromatic relative to aliphatic compounds of similar...

  2. Model and experiments of diesel fuel HCCI combustion with external mixture formation

    Energy Technology Data Exchange (ETDEWEB)

    Canova, M.; Vosz, A.; Dumbauld, D.; Garcin, R.; Midlam-Mohler, S.; Guezennec, Y.; Rizzoni, G. [Ohio State Univ. (United States)

    2005-07-01

    Homogeneous Charge Compression Ignition represents a promising concept for achieving high efficiencies and low emissions at part-load operations. In particular, HCCI combustion can be successfully applied to conventional Direct Injection Diesel engines with very low extra costs and no modification to the DI system by performing the mixture formation in the intake manifold with a novel fuel atomizer. The present paper describes the experimental and modeling activity oriented to the control of HCCI combustion on a conventional CIDI 4-cylinder engine fitted with this external fueling device. Paralleling preliminary results obtained last year on single-cylinder engine in collaboration with FKFS at the University of Stuttgart, Diesel-fuel HCCI combustion was achieved and characterized over a range of engine speeds, loads, EGR dilution and boost pressure. Stable HCCI combustion with negligible NO{sub x} formation (10 ppm) was achieved with no modification of a high compression ratio engine (c{sub r}=18). The in-cylinder pressure traces were analyzed by performing a detailed heat release analysis while accounting for the wall heat transfer, which is substantially higher during the combustion phase than in a conventional CIDI engine. This analysis led to the joint identification of 2 sub-models: a heat transfer model, and a heat release model. It was found that under the wide range of conditions experimentally measured, the heat release can be approximated by the superposition of 3 Wiebe functions. The sub-models developed were then implemented in a combustion model based on a first-law thermodynamic analysis of in-cylinder processes, in order to identify the influence of the main control parameters on HCCI auto-ignition and to control the combustion process in a HCCI Diesel engine with external mixture formation. The model predictions were then compared to the results of a parallel experimental activity made on a 4-cylinder CIDI Diesel engine equipped with the fuel

  3. Good reliability and validity for a new utility instrument measuring the birth experience, the Labor and Delivery Index

    NARCIS (Netherlands)

    Gärtner, F.R.; Miranda, E. de; Rijnders, M.E.; Freeman, L.M.; Middeldorp, J.M.; Bloemenkamp, K.W.M.; Stiggelbout, A.M.; Akker-van Marle, M.E. van den

    2015-01-01

    Objectives To validate the Labor and Delivery Index (LADY-X), a new delivery-specific utility measure. Study Design and Setting In a test–retest design, women were surveyed online, 6 to 8 weeks postpartum and again 1 to 2 weeks later. For reliability testing, we assessed the standard error of

  4. Industrial experience on the development of the molten carbonate fuel cell technology

    Energy Technology Data Exchange (ETDEWEB)

    Bosio, B.; Costamagna, P. [Ist. di Ingegneria Chimica e di Processo ``G.B. Bonino`` Univ. di Genova (Italy); Parodi, F.; Passalacqua, B. [Ansaldo Ricerche, Genova (Italy)

    1998-08-01

    The development of the molten carbonate fuel cell (MCFC) technology at Ansaldo Ricerche (ARI) is reported, starting from small scale single cells up to stacks of several kW capacity. The evolution of material and fabrication strategies as well as the progress in terms of electrical performance are described and discussed. The data reported show that the MCFC technology has been successfully tested on stacks in the kW power class, however some problems still need to be solved to improve the stack performance. In particular, better control of the start-up phase, of electrolyte migration through the manifolds and of the gas feed distribution are required, based on the latest experimental data on a 50 cell stack with cell area 0.1 m{sup 2} (cell active area 0.0702 m{sup 2}), which operated for 780 h with a maximum performance of 4 kW at 206 mA/cm{sup 2} at 50% fuel utilisation. Future development steps, which will lead to the realisation and operation of systems of several hundred kW, are presented. (orig.)

  5. Differential Die-Away Instrument: Report on Initial Simulations of Spent Fuel Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Goodsell, Alison V. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Henzl, Vladimir [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Swinhoe, Martyn T. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-04-01

    New Monte Carlo simulations of the differential die-away (DDA) instrument response to the assay of spent and fresh fuel helped to redefine the signal-to-Background ratio and the effects of source neutron tailoring on the system performance. Previously, burst neutrons from the neutron generator together with all neutrons from a fission chain started by a fast fission of 238U were considered to contribute to active background counts. However, through additional simulations, the magnitude of the 238U first fission contribution was found to not affect the DDA performance in reconstructing 239Pueff. As a result, the newly adopted DDA active background definition considers now any neutrons within a branch of the fission chain that does not include at least one fission event induced by a thermal neutron, before being detected, to be the active background. The active background, consisting thus of neutrons from a fission chain or its individual branches composed entirely of sequence of fast fissions on any fissile or fissionable nuclei, is not expected to change significantly with different fuel assemblies. Additionally, while source tailoring materials surrounding the neutron generator were found to influence and possibly improve the instrument performance, the effect was not substantial.

  6. Reliability assessment of high energy particle induced radioactivity calculation code DCHAIN-SP 2001 by analysis of integral activation experiments with 14 MeV neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Kai, Tetsuya; Maekawa, Fujio; Kasugai, Yoshimi; Takada, Hiroshi; Ikeda, Yujiro [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Kosako, Kazuaki [Sumitomo Atomic Energy Industries, Ltd., Tokyo (Japan)

    2002-03-01

    Reliability assessment for the high energy particle induced radioactivity calculation code DCHAIN-SP 2001 was carried out through analysis of integral activation experiments with 14-MeV neutrons aiming at validating the cross section and decay data revised from previous version. The following three kinds of experiments conducted at the D-T neutron source facility, FNS, in JAERI were employed: (1) the decay gamma-ray measurement experiment for fusion reactor materials, (2) the decay heat measurement experiment for 32 fusion reactor materials, and (3) the integral activation experiment on mercury. It was found that the calculations with DCHAIN-SP 2001 predicted the experimental data for (1) - (3) within several tens of percent. It was concluded that the cross section data below 20 MeV and the associated decay data as well as the calculation algorithm for solving the Beteman equation that was the master equation of DCHAIN-SP were adequate. (author)

  7. Progress and prospects of nuclear fuel development in Japan, (2). Progress and future plan of research and development on PWR fuel in Japan

    Energy Technology Data Exchange (ETDEWEB)

    Kondo, Yoshiaki; Abeta, Sadaaki; Aisu, Hideo; Teranishi, Tomoyuki

    1982-06-01

    13 years have elapsed since the first PWR plant started the operation in Japan, and at present, 11 PWR plants are in operation. During this period, much results of use and experience have been accumulated for the PWR fuel. The improvement and development of the fuel have been performed to meet the supply of the fuel sufficiently adaptable to the severe environment in Japan. In this paper, the evaluation of soundness and the improvement of reliability of PWR fuel made so far are reported, and the response of fuel side to long cycle operation and load following-up operation, which will be required in near future, is explained. The inspection of fuel has been performed at reactor sites for the purpose of sufficiently observing the irradiation behavior of fuel and detecting the points out of order. Effort has been exerted to perform various inspections thoroughly on total number of fuel and reflect the results to the improved design. Fuel leak scarcely occurred from the beginning, accordingly, improvement has been made to reduce the bending of fuel rods. The change of PWR fuel design, the evaluation of soundness and the improvement of reliability of PWR fuel, and the improvement for the future are reported.

  8. Reactor physics studies for the Advanced Fuel Cycle Initiative (AFCI) Reactor-Accelerator Coupling Experiments (RACE) Project

    Science.gov (United States)

    Stankovskiy, Evgeny Yuryevich

    In the recently completed RACE Project of the AFCI, accelerator-driven subcritical systems (ADS) experiments were conducted to develop technology of coupling accelerators to nuclear reactors. In these experiments electron accelerators induced photon-neutron reactions in heavy-metal targets to initiate fission reactions in ADS. Although the Idaho State University (ISU) RACE ADS was constructed only to develop measurement techniques for advanced experiments, many reactor kinetics experiments were conducted there. In the research reported in this dissertation, a method was developed to calculate kinetics parameters for measurement and calculation of the reactivity of ADS, a safety parameter that is necessary for control and monitoring of power production. Reactivity is measured in units of fraction of delayed versus prompt neutron from fission, a quantity that cannot be directly measured in far-subcritical reactors such as the ISU RACE configuration. A new technique is reported herein to calculate it accurately and to predict kinetic behavior of a far-subcritical ADS. Experiments conducted at ISU are first described and experimental data are presented before development of the kinetic theory used in the new computational method. Because of the complexity of the ISU ADS, the Monte-Carlo method as applied in the MCNP code is most suitable for modeling reactor kinetics. However, the standard method of calculating the delayed neutron fraction produces inaccurate values. A new method was developed and used herein to evaluate actual experiments. An advantage of this method is that its efficiency is independent of the fission yield of delayed neutrons, which makes it suitable for fuel with a minor actinide component (e.g. transmutation fuels). The implementation of this method is based on a correlated sampling technique which allows the accurate evaluation of delayed and prompt neutrons. The validity of the obtained results is indicated by good agreement between experimental

  9. Review Of Decommissioning Experience In Spent Fuel Reprocessing Facilities at Marcoule

    Energy Technology Data Exchange (ETDEWEB)

    Guiberteau, Ph.; Vendroux, M. [CODEM GIE, BP 21004, 30201 Bagnols sur Ceze cedex (France); Berlan, C. [COGEMA Reprocessing Business Unit, 2, rue Paul Dautier - BP.4, 78141 Velizy Cedex (France)

    2003-07-01

    Final shutdown and decontamination, dismantling, and legacy waste retrieval programs are currently in progress at the Marcoule nuclear fuel reprocessing plant in southern France. They began in 1998 and will continue until about 2040. CODEM is the funding, decision-making and inspection organization for these decommissioning operations, COGEMA is the nuclear operator and the industrial contractor. After an overview of the facilities, the project and the participants, most significant operations are discussed in greater detail. High activity levels and the presence of large quantities of {alpha}-emitters complicate operating and waste treatment conditions. The major issues impacting cost-effectiveness-scenario, waste removal and project organization will be highlighted in the conclusion.

  10. Model optimization method and connected-pipe experiment of a liquid fuel ramjet engine

    Institute of Scientific and Technical Information of China (English)

    MA Qian-rong; GUO Xin; WU Hu; CHOU Qian

    2013-01-01

    The optimization method of a mathematical model and connected-pipe experimental technique for a test in altitude test facility (ATF) of a liquid fuel ramjet engine was researched.The optimization of the simple mathematical model was divided into two steps.Firstly,using the test engine's geometry configuration size data,a preliminary adjustment was done.Secondly,using experimental test data,the components' experiential coefficients were modified appropriately.Emphasis was laid on the simulation technique of flight condition and parameters measurement method.The experimental technique was applied to a ramjet ATF test successfully.The comparison results show that the optimized-model has higher precision and the nozzle gross thrust difference drops from 12% to about 4%.

  11. Differential die-away instrument: Report on comparison of fuel assembly experiments and simulations

    Energy Technology Data Exchange (ETDEWEB)

    Goodsell, Alison Victoria [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Henzl, Vladimir [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Swinhoe, Martyn Thomas [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Rael, Carlos D. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Desimone, David J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-01-14

    Experimental results of the assay of mock-up (fresh) fuel with the differential die-away (DDA) instrument were compared to the Monte Carlo N-Particle eXtended (MCNPX) simulation results. Most principal experimental observables, the die-away time and the in tegral of the DDA signal in several time domains, have been found in good agreement with the MCNPX simulation results. The remaining discrepancies between the simulation and experimental results are likely due to small differences between the actual experimental setup and the simulated geometry, including uncertainty in the DT neutron generator yield. Within this report we also present a sensitivity study of the DDA instrument which is a complex and sensitive system and demonstrate to what degree it can be impacted by geometry, material composition, and electronics performance.

  12. Patient experiences questionnaire for interdisciplinary treatment for substance dependence (PEQ-ITSD): reliability and validity following a national survey in Norway.

    Science.gov (United States)

    Haugum, Mona; Iversen, Hilde Hestad; Bjertnaes, Oyvind; Lindahl, Anne Karin

    2017-02-20

    Patient experiences are an important aspect of health care quality, but there is a lack of validated instruments for their measurement in the substance dependence literature. A new questionnaire to measure inpatients' experiences of interdisciplinary treatment for substance dependence has been developed in Norway. The aim of this study was to psychometrically test the new questionnaire, using data from a national survey in 2013. The questionnaire was developed based on a literature review, qualitative interviews with patients, expert group discussions and pretesting. Data were collected in a national survey covering all residential facilities with inpatients in treatment for substance dependence in 2013. Data quality and psychometric properties were assessed, including ceiling effects, item missing, exploratory factor analysis, and tests of internal consistency reliability, test-retest reliability and construct validity. The sample included 978 inpatients present at 98 residential institutions. After correcting for excluded patients (n = 175), the response rate was 91.4%. 28 out of 33 items had less than 20.5% of missing data or replies in the "not applicable" category. All but one item met the ceiling effect criterion of less than 50.0% of the responses in the most favorable category. Exploratory factor analysis resulted in three scales: "treatment and personnel", "milieu" and "outcome". All scales showed satisfactory internal consistency reliability (Cronbach's alpha ranged from 0.75-0.91) and test-retest reliability (ICC ranged from 0.82-0.85). 17 of 18 significant associations between single variables and the scales supported construct validity of the PEQ-ITSD. The content validity of the PEQ-ITSD was secured by a literature review, consultations with an expert group and qualitative interviews with patients. The PEQ-ITSD was used in a national survey in Norway in 2013 and psychometric testing showed that the instrument had satisfactory internal consistency

  13. Fuel Cell Power Plants Renewable and Waste Fuels

    Science.gov (United States)

    2011-01-13

    Fuel Cell Power Plants Renewable and Waste Fuels DOE-DOD Workshop Washington, DC. January 13, 2011 reliable, efficient, ultra-clean Report...2011 2. REPORT TYPE 3. DATES COVERED 00-00-2011 to 00-00-2011 4. TITLE AND SUBTITLE Fuel Cell Power Plants Renewable and Waste Fuels 5a. CONTRACT...Approved for public release; distribution unlimited 13. SUPPLEMENTARY NOTES presented at the DOE-DOD Waste-to-Energy using Fuel Cells Workshop held

  14. Development and design of experiments optimization of a high temperature proton exchange membrane fuel cell auxiliary power unit with onboard fuel processor

    Science.gov (United States)

    Karstedt, Jörg; Ogrzewalla, Jürgen; Severin, Christopher; Pischinger, Stefan

    In this work, the concept development, system layout, component simulation and the overall DOE system optimization of a HT-PEM fuel cell APU with a net electric power output of 4.5 kW and an onboard methane fuel processor are presented. A highly integrated system layout has been developed that enables fast startup within 7.5 min, a closed system water balance and high fuel processor efficiencies of up to 85% due to the recuperation of the anode offgas burner heat. The integration of the system battery into the load management enhances the transient electric performance and the maximum electric power output of the APU system. Simulation models of the carbon monoxide influence on HT-PEM cell voltage, the concentration and temperature profiles within the autothermal reformer (ATR) and the CO conversion rates within the watergas shift stages (WGSs) have been developed. They enable the optimization of the CO concentration in the anode gas of the fuel cell in order to achieve maximum system efficiencies and an optimized dimensioning of the ATR and WGS reactors. Furthermore a DOE optimization of the global system parameters cathode stoichiometry, anode stoichiometry, air/fuel ratio and steam/carbon ratio of the fuel processing system has been performed in order to achieve maximum system efficiencies for all system operating points under given boundary conditions.

  15. Validation Experiments for Spent- Fuel Dry-Cask In-Basket Convection

    Energy Technology Data Exchange (ETDEWEB)

    Smith, barton [Utah State Univ., Logan, UT (United States)

    2016-08-16

    This work consisted of the following major efforts; 1. Literature survey on validation of external natural convection; 2. Design the experiment; 3. Build the experiment; 4. Run the experiment; 5. Collect results; 6. Disseminate results; and 7. Perform a CFD validation study using the results. We note that while all tasks are complete, some deviations from the original plan were made. Specifically, geometrical changes in the parameter space were skipped in favor of flow condition changes, which were found to be much more practical to implement. Changing the geometry required new as-built measurements, which proved extremely costly and impractical given the time and funds available

  16. Validation Experiments for Spent-Fuel Dry-Cask In-Basket Convection

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Barton L. [Utah State Univ., Logan, UT (United States). Dept. of Mechanical and Aerospace Engineering

    2016-08-16

    This work consisted of the following major efforts; 1. Literature survey on validation of external natural convection; 2. Design the experiment; 3. Build the experiment; 4. Run the experiment; 5. Collect results; 6. Disseminate results; and 7. Perform a CFD validation study using the results. We note that while all tasks are complete, some deviations from the original plan were made. Specifically, geometrical changes in the parameter space were skipped in favor of flow condition changes, which were found to be much more practical to implement. Changing the geometry required new as-built measurements, which proved extremely costly and impractical given the time and funds available

  17. Nitrogen isotopic evidence for a shift from nitrate- to diazotroph-fueled export production in the VAHINE mesocosm experiments

    Science.gov (United States)

    Knapp, Angela N.; Fawcett, Sarah E.; Martínez-Garcia, Alfredo; Leblond, Nathalie; Moutin, Thierry; Bonnet, Sophie

    2016-08-01

    In a coastal lagoon with a shallow, 25 m water column off the southwest coast of New Caledonia, large-volume ( ˜ 50 m3) mesocosm experiments were undertaken to track the fate of newly fixed nitrogen (N). The mesocosms were intentionally fertilized with 0.8 µM dissolved inorganic phosphorus to stimulate diazotrophy. N isotopic evidence indicates that the dominant source of N fueling export production shifted from subsurface nitrate (NO3-) assimilated prior to the start of the 23-day experiments to N2 fixation by the end of the experiments. While the δ15N of the sinking particulate N (PNsink) flux changed during the experiments, the δ15N of the suspended PN (PNsusp) and dissolved organic N (DON) pools did not. This is consistent with previous observations that the δ15N of surface ocean N pools is less responsive than that of PNsink to changes in the dominant source of new N to surface waters. In spite of the absence of detectable NO3- in the mesocosms, the δ15N of PNsink indicated that NO3- continued to fuel a significant fraction of export production (20 to 60 %) throughout the 23-day experiments, with N2 fixation dominating export after about 2 weeks. The low rates of organic N export during the first 14 days were largely supported by NO3-, and phytoplankton abundance data suggest that sinking material primarily comprised large diatoms. Concurrent molecular and taxonomic studies indicate that the diazotroph community was dominated by diatom-diazotroph assemblages (DDAs) at this time. However, these DDAs represented a minor fraction (< 5 %) of the total diatom community and contributed very little new N via N2 fixation; they were thus not important for driving export production, either directly or indirectly. The unicellular cyanobacterial diazotroph, a Cyanothece-like UCYN-C, proliferated during the last phase of the experiments when N2 fixation, primary production, and the flux of PNsink increased significantly, and δ15N budgets reflected a predominantly

  18. Fuel loading experiments of IPEN/MB-01 reactor core; Experimento de carregamento do nucleo do reator IPEN/MB-01

    Energy Technology Data Exchange (ETDEWEB)

    Abe, Alfredo; Angioletto, Elcio; Pasqualetto, Hertz; Moreira, Joao M.L.; Sabo, Marcos A.; Fuga, Rinaldo [Centro Tecnologico da Marinha em Sao Paulo (CTMSP), SP (Brazil). E-mail: ayabe@net.ipen.br; Jerez, Rogerio [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)

    2000-07-01

    IPEN/MB-01 is a critical assembly which reaches a first critically at November 1998, since then a several experiments have been conducted in order to validate and qualify the reactor Physics methodologies and codes. Recently, loading experiment was performed to determine the critical number of fuels rods using a multiplication inverse technique (1/M). The experiment can be considered as benchmark and contribute toward reactor physics methodologies, codes and basic nuclear data libraries validation qualification. (author)

  19. Common feature of concave growth pattern of oscillations in terms of speed, acceleration, fuel consumption and emission in car following: experiment and modeling

    CERN Document Server

    Tian, Junfang; Treiber, Martin; Ma, Shoufeng; Jia, Bin; Zhang, Wenyi

    2016-01-01

    This paper has investigated the growth pattern of traffic oscillations by using vehicle trajectory data in a car following experiment. We measured the standard deviation of acceleration, emission and fuel consumption of each vehicle in the car-following platoon. We found that: (1) Similar to the standard deviation of speed, these indices exhibit a common feature of concave growth pattern along vehicles in the platoon; (2) The emission and fuel consumption of each vehicle decrease remarkably when the average speed of the platoon increases from low value; However, when reaches 30km/h, the change of emission and fuel consumption with is not so significant; (3), the correlations of emission and fuel consumption with both the standard deviation of acceleration and the speed oscillation are strong. Simulations show that with the memory effect of drivers taken into account, the improved two-dimensional intelligent driver model is able to reproduce the common feature of traffic oscillation evolution quite well.

  20. A systematic review of the reliability and validity of discrete choice experiments in valuing non-market environmental goods

    DEFF Research Database (Denmark)

    Rokotonarivo, Sarobidy; Schaafsma, Marije; Hockley, Neal

    2016-01-01

    reliability measures. DCE results were generally consistent with those of other stated preference techniques (convergent validity), but hypothetical bias was common. Evidence supporting theoretical validity (consistency with assumptions of rational choice theory) was limited. In content validity tests, 2......–90% of respondents protested against a feature of the survey, and a considerable proportion found DCEs to be incomprehensible or inconsequential (17–40% and 10–62% respectively). DCE remains useful for non-market valuation, but its results should be used with caution. Given the sparse and inconclusive evidence base...

  1. Quantum Mechanics Studies of Fuel Cell Catalysts and Proton Conducting Ceramics with Validation by Experiment

    Science.gov (United States)

    Tsai, Ho-Cheng

    We carried out quantum mechanics (QM) studies aimed at improving the performance of hydrogen fuel cells. In part I, The challenge was to find a replacement for the Pt cathode that would lead to improved performance for the Oxygen Reduction Reaction (ORR) while remaining stable under operational conditions and decreasing cost. Our design strategy was to find an alloy with composition Pt3M that would lead to surface segregation such that the top layer would be pure Pt, with the second and subsequent layers richer in M. Under operating conditions we expect the surface to have significant O and/or OH chemisorbed on the surface; we searched for M that would remain segregated under these conditions. Using QM we examined surface segregation for 28 Pt3M alloys, where M is a transition metal. We found that only Pt3Os and Pt3Ir showed significant surface segregation when O and OH are chemisorbed on the catalyst surfaces. This result indicates that Pt3Os and Pt 3Ir favor formation of a Pt-skin surface layer structure that would resist the acidic electrolyte corrosion during fuel cell operation environments. We chose to focus on Os because the phase diagram for Pt-Ir indicated that Pt-Ir could not form a homogeneous alloy at lower temperature. To determine the performance for ORR, we used QM to examine intermediates, reaction pathways, and reaction barriers involved in the processes for which protons from the anode reactions react with O2 to form H2O. These QM calculations used our Poisson-Boltzmann implicit solvation model include the effects of the solvent (water with dielectric constant 78 with pH 7 at 298K). We also carried out similar QM studies followed by experimental validation for the Os/Pt core-shell catalyst fabricated by the underpotential deposition (UPD) method. The QM results indicated that the RDS for ORR is a compromise between the OOH formation step (0.37 eV for Pt, 0.23 eV for Pt2ML/Os core-shell) and H2O formation steps (0.32 eV for Pt, 0.22 eV for Pt2ML

  2. Experiments on water detritiation and cryogenic distillation at TLK; Impact on ITER fuel cycle subsystems interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Cristescu, I.; Cristescu, I. R.; Doerr, L.; Hellriegel, G.; Michling, R. [Forschungszentrum Karlsruhe, Inst. for Technical Physics, Tritium Laboratory Karlsruhe, P.O. Box 3640, D- 76021 Karlsruhe (Germany); Murdoch, D. [EFDA CSU, MPI fuer Plasmaphysik, Garching (Germany); Schaefer, P.; Welte, S.; Wurster, W. [Forschungszentrum Karlsruhe, Inst. for Technical Physics, Tritium Laboratory Karlsruhe, P.O. Box 3640, D- 76021 Karlsruhe (Germany)

    2008-07-15

    The ITER Isotope Separation System (ISS) and Water Detritiation System (WDS) should be integrated in order to reduce potential chronic tritium emissions from the ISS. This is achieved by routing the top (protium) product from the ISS to a feed point near the bottom end of the WDS Liquid Phase Catalytic Exchange (LPCE) column. This provides an additional barrier against ISS emissions and should mitigate the memory effects due to process parameter fluctuations in the ISS. To support the research activities needed to characterize the performances of various components for WDS and ISS processes under various working conditions and configurations as needed for ITER design, an experimental facility called TRENTA representative of the ITER WDS and ISS protium separation column, has been commissioned and is in operation at TLK The experimental program on TRENTA facility is conducted to provide the necessary design data related to the relevant ITER operating modes. The operation availability and performances of ISS-WDS have impact on ITER fuel cycle subsystems with consequences on the design integration. The preliminary experimental data on TRENTA facility are presented. (authors)

  3. MEMS reliability

    CERN Document Server

    Hartzell, Allyson L; Shea, Herbert R

    2010-01-01

    This book focuses on the reliability and manufacturability of MEMS at a fundamental level. It demonstrates how to design MEMs for reliability and provides detailed information on the different types of failure modes and how to avoid them.

  4. Fuels and Lubricants Facility

    Data.gov (United States)

    Federal Laboratory Consortium — Modern naval aircraft and turbine-powered craft require reliable and high-quality fuels and lubricants to satisfy the demands imposed upon them for top performance...

  5. Fuel condition in Canadian CANDU 6 reactors

    Energy Technology Data Exchange (ETDEWEB)

    Hu, R.H.; Macici, N [Hydro-Quebec, Montreal, Quebec (Canada); Gibb, R. [New Brunswick Power, Lepreau, NB (Canada); Purdy, P.L.; Manzer, A.M. [Atomic Energy of Canada Limited, Mississauga, Ontario (Canada); Kohn, E. [Ontario Hydro, Toronto, Ontario (Canada)

    1997-07-01

    The cornerstone of the CANDU concept is its natural uranium fuel, and the success of its reactor operation hinges on the fuel condition in the reactor. Neutron economy, on power refuelling, and simple fuel design are among the unique characteristics of CANDU fuel. In Canadian CANDU 6 reactors (Gentilly 2 and Point Lepreau), the 37-element fuel has provided an enviable record of safe, economic and reliable plant operation for 29 reactor years to date. The fuelling cost is among the lowest in the world - a corollary of high neutron economy, simple fuel design, and judicial fuelling scheme. The reliability of fuel is high: only 21 of the 60000 bundles discharged from Gentilly 2 were confirmed defective and the five-year period from March 1992 to February 1997 saw no defect at all at Gentilly-2. Also, thanks to the inherent on-power refuelling capability and an effective defect detection and removal system, the primary coolant loops are kept extremely clean (very low activity level) - benefiting both maintenance and safety. Moreover, the inventories of fission products in the core and in the channel are maintained within the safety analysis envelope, due to on-power fuelling and sophisticated fuel management. In this paper, CANDU 6 fuel performance is reviewed against the feedback from post-irradiation examinations, and the findings from our ongoing R and D program. The results suggest that the fuel behavior m reactor are basically as originally anticipated, despite an evolutionary 3% increase in bundle uranium mass in the 1980's. For operating conditions within the CANDU 6 37-element experience, the average strains are typically 0.09%; and fission gas release, 2.7%. The UO{sub 2} fuel remains stoichiometric after irradiation. In-core measurements of pressure tube fitting are generally low. All these observations are consistent with the excellent fuel performance statistics coming out of the two Canadian CANDU 6 reactors. Additionally, this paper will briefly

  6. Danish Experiences with Deposit Probe Measurements in Grate and Pulverized Fuel Biomass Power Boilers

    DEFF Research Database (Denmark)

    Hansen, Stine Broholm; Jensen, Peter Arendt; Jappe Frandsen, Flemming

    2012-01-01

    Several measuring campaigns with focus on deposition behavior have been conducted at full-scale power plants firing biomass in Denmark. These campaigns have been reviewed in this work. The focus is the obtained experiences on deposit formation, shedding and chemistry. When comparing results from...

  7. Software reliability

    CERN Document Server

    Bendell, A

    1986-01-01

    Software Reliability reviews some fundamental issues of software reliability as well as the techniques, models, and metrics used to predict the reliability of software. Topics covered include fault avoidance, fault removal, and fault tolerance, along with statistical methods for the objective assessment of predictive accuracy. Development cost models and life-cycle cost models are also discussed. This book is divided into eight sections and begins with a chapter on adaptive modeling used to predict software reliability, followed by a discussion on failure rate in software reliability growth mo

  8. Design and implementation of a reliable and cost-effective cloud computing infrastructure: the INFN Napoli experience

    Science.gov (United States)

    Capone, V.; Esposito, R.; Pardi, S.; Taurino, F.; Tortone, G.

    2012-12-01

    Over the last few years we have seen an increasing number of services and applications needed to manage and maintain cloud computing facilities. This is particularly true for computing in high energy physics, which often requires complex configurations and distributed infrastructures. In this scenario a cost effective rationalization and consolidation strategy is the key to success in terms of scalability and reliability. In this work we describe an IaaS (Infrastructure as a Service) cloud computing system, with high availability and redundancy features, which is currently in production at INFN-Naples and ATLAS Tier-2 data centre. The main goal we intended to achieve was a simplified method to manage our computing resources and deliver reliable user services, reusing existing hardware without incurring heavy costs. A combined usage of virtualization and clustering technologies allowed us to consolidate our services on a small number of physical machines, reducing electric power costs. As a result of our efforts we developed a complete solution for data and computing centres that can be easily replicated using commodity hardware. Our architecture consists of 2 main subsystems: a clustered storage solution, built on top of disk servers running GlusterFS file system, and a virtual machines execution environment. GlusterFS is a network file system able to perform parallel writes on multiple disk servers, providing this way live replication of data. High availability is also achieved via a network configuration using redundant switches and multiple paths between hypervisor hosts and disk servers. We also developed a set of management scripts to easily perform basic system administration tasks such as automatic deployment of new virtual machines, adaptive scheduling of virtual machines on hypervisor hosts, live migration and automated restart in case of hypervisor failures.

  9. Final Progress Report: Direct Experiments on the Ocean Disposal of Fossil Fuel CO2.

    Energy Technology Data Exchange (ETDEWEB)

    James P. Barry; Peter G. Brewer

    2004-05-25

    OAK-B135 This report summarizes activities and results of investigations of the potential environmental consequences of direct injection of carbon dioxide into the deep-sea as a carbon sequestration method. Results of field experiments using small scale in situ releases of liquid CO2 are described in detail. The major conclusions of these experiments are that mortality rates of deep sea biota will vary depending on the concentrations of CO2 in deep ocean waters that result from a carbon sequestration project. Large changes in seawater acidity and carbon dioxide content near CO2 release sites will likely cause significant harm to deep-sea marine life. Smaller changes in seawater chemistry at greater distances from release sites will be less harmful, but may result in significant ecosystem changes.

  10. Fate of Methane and Ethanol-Blended Fuels in Soil: Laboratory and Field Experiments

    Science.gov (United States)

    Mackay, D. M.; de Sieyes, N. R.; Peng, J.; Schmidt, R.; Buelow, M. C.; Felice, M.

    2015-12-01

    Our research site is within the UC Davis Putah Creek Riparian Reserve in Davis, CA; climate is semi-arid and soils are sandy loams and silts. We are conducting three types of controlled release experiments in the field: 1) Gas mixture, a continuous release of methane, sometimes with other gases included, with the composition and release rate changing over time to allow examination of various hypotheses, 2) E10 (gasoline with 10% ethanol): a continuous release of E10 NAPL at rate equal to documented low rate releases from underground storage tanks (USTs) that are difficult or impossible to detect with current practical approaches (<0.04 gallons per day); 3) E85: release at same rate as the E10 release. In the field experiments, gas or NAPL is released from a stainless steel drive point with 0.5 cm slotted section at 1 m bgs; we monitor temperature, pressure, moisture content, and soil gas composition in the soil, and efflux of carbon dioxide, methane, oxygen, water vapor, and other species to/ from soil to atmosphere. Periodic coring allows examination of the microbial community composition with depth. Laboratory microcosm and column tests assisted in planning the E10 and E85 field experiments above, evaluated the effect of moisture content on methane oxidation, and allowed testing and refinement of the monitoring approaches in the field We found that up to 40% of the methane released can be accounted for by efflux from soil to the atmosphere. The percentage in the efflux depends on the rate of release, and, based on literature and our microcosms with methane-spiked PCRR soils, we hypothesize that the very low moisture content of the soils in this drought year limits in situ methane oxidation. Efflux of carbon dioxide accounted for up to 20% of the E10 release rate under our lab column conditions, which we believe were oxygen-limited compared to the field conditions. We also detected low molecular weight hydrocarbons in the column efflux, though the concentrations

  11. First elevated-temperature performance testing of coated particle fuel compacts from the AGR-1 irradiation experiment

    Energy Technology Data Exchange (ETDEWEB)

    Charles A. Baldwin; John D. Hunn; Robert N. Morris; Fred C. Montgomery; Chinthaka M. Silva; Paul A. Demkowicz

    2014-05-01

    In the AGR-1 irradiation experiment, 72 coated-particle fuel compacts were taken to a peak burnup of 19.5% fissions per initial metal atom with no in-pile failures. This paper discusses the first post-irradiation test of these mixed uranium oxide/uranium carbide fuel compacts at elevated temperature to examine the fuel performance under a simulated depressurized conduction cooldown event. A compact was heated for 400 h at 1600 degrees C. Release of 85Kr was monitored throughout the furnace test as an indicator of coating failure, while other fission product releases from the compact were periodically measured by capturing them on exchangeable, water-cooled deposition cups. No coating failure was detected during the furnace test, and this result was verified by subsequent electrolytic deconsolidation and acid leaching of the compact, which showed that all SiC layers were still intact. However, the deposition cups recovered significant quantities of silver, europium, and strontium. Based on comparison of calculated compact inventories at the end of irradiation versus analysis of these fission products released to the deposition cups and furnace internals, the minimum estimated fractional losses from the compact during the furnace test were 1.9 x 10-2 for silver, 1.4 x 10-3 for europium, and 1.1 x 10-5 for strontium. Other post-irradiation examination of AGR-1 compacts indicates that similar fractions of europium and silver may have already been released by the intact coated particles during irradiation, and it is therefore likely that the detected fission products released from the compact in this 1600 degrees C furnace test were from residual fission products in the matrix. Gamma analysis of coated particles deconsolidated from the compact after the heating test revealed that silver content within each particle varied considerably; a result that is probably not related to the furnace test, because it has also been observed in other as-irradiated AGR-1 compacts. X

  12. Willow as fuel for district heating. Experiences from test combustion; Energipil som braendsel til fjernvarme - Erfaringsindsamling fra testfyringer

    Energy Technology Data Exchange (ETDEWEB)

    Pedersen, Joergen

    2012-10-15

    The project has been a study of the fuel characteristics of willow chips. The study was carried out on Trustrup-Lyngby Heating Plant and Assens District Heating Plant in the period 2011-12. Operating experiences were collected from the two plants. Furthermore, yield and crop data were collected from suppliers of willow chips to Assens District Heating Plant, and the analysis of particle size distribution of the willow chips is carried out. The collected data on yield and particle size distribution are compared with results from previous studies. The project has shown that willow chips generally are a suitable and attractive fuel in wood-fired heat and power plants. The plants are very aware of quality of willow chips and want chips with coarse structure. Furthermore, there is the wish that water content of willow chips are on par with the moisture content of wood chips, i.e. around 30-40%; woodchips are the vast majority of the chips used in the plants. Wood chips produced from fresh willow shoots with chopper will typically have a moisture content of 50-60 %. Such ''wet'' chips will of some plants be deselected during winter, where there is a requirement of safe and high boiler output. Other plants will simply mix the ''wet'' willow chips with other, drier types of chips and can use it almost all the year. If the willow shoots are harvested as branches, which subsequently are allowed to dry for a period before chipping, willow chips can be produced with a moisture content that is in line with what is typical in wood chips. Analysis of particle size distribution shows that willow chips harvested with a cutting machine usually can meet the requirements for quality classes ''fine'', ''medium'' and ''coarse''. An account of the harvested yields of willow among the growers who supplied willow chips to Assens Heating Plant, showed a relatively low yield of 5.1 tonnes dry

  13. Willow as fuel for district heating. Experiences from test combustion; Energipil som braendsel til fjernvarme - Erfaringsindsamling fra testfyringer

    Energy Technology Data Exchange (ETDEWEB)

    Pedersen, Joergen

    2012-10-15

    The project has been a study of the fuel characteristics of willow chips. The study was carried out on Trustrup-Lyngby Heating Plant and Assens District Heating Plant in the period 2011-12. Operating experiences were collected from the two plants. Furthermore, yield and crop data were collected from suppliers of willow chips to Assens District Heating Plant, and the analysis of particle size distribution of the willow chips is carried out. The collected data on yield and particle size distribution are compared with results from previous studies. The project has shown that willow chips generally are a suitable and attractive fuel in wood-fired heat and power plants. The plants are very aware of quality of willow chips and want chips with coarse structure. Furthermore, there is the wish that water content of willow chips are on par with the moisture content of wood chips, i.e. around 30-40%; woodchips are the vast majority of the chips used in the plants. Wood chips produced from fresh willow shoots with chopper will typically have a moisture content of 50-60 %. Such ''wet'' chips will of some plants be deselected during winter, where there is a requirement of safe and high boiler output. Other plants will simply mix the ''wet'' willow chips with other, drier types of chips and can use it almost all the year. If the willow shoots are harvested as branches, which subsequently are allowed to dry for a period before chipping, willow chips can be produced with a moisture content that is in line with what is typical in wood chips. Analysis of particle size distribution shows that willow chips harvested with a cutting machine usually can meet the requirements for quality classes ''fine'', ''medium'' and ''coarse''. An account of the harvested yields of willow among the growers who supplied willow chips to Assens Heating Plant, showed a relatively low yield of 5.1 tonnes dry

  14. First elevated-temperature performance testing of coated particle fuel compacts from the AGR-1 irradiation experiment

    Energy Technology Data Exchange (ETDEWEB)

    Baldwin, Charles A., E-mail: baldwinca@ornl.gov [Oak Ridge National Laboratory (ORNL), P.O. Box 2008, Oak Ridge, TN 37831-6295 (United States); Hunn, John D.; Morris, Robert N.; Montgomery, Fred C.; Silva, Chinthaka M. [Oak Ridge National Laboratory (ORNL), P.O. Box 2008, Oak Ridge, TN 37831-6295 (United States); Demkowicz, Paul A. [Idaho National Laboratory (INL), P.O. Box 1625, Idaho Falls, ID 83414 (United States)

    2014-05-01

    In the AGR-1 irradiation experiment, 72 coated-particle fuel compacts were taken to a peak burnup of 19.5% fissions per initial metal atom with no in-pile failures. This paper discusses the first post-irradiation test of these mixed uranium oxide/uranium carbide fuel compacts at elevated temperature to examine the fuel performance under a simulated depressurized conduction cooldown event. A compact was heated for 400 h at 1600 °C. Release of {sup 85}Kr was monitored throughout the furnace test as an indicator of coating failure, while other fission product releases from the compact were periodically measured by capturing them on exchangeable, water-cooled deposition cups. No coating failure was detected during the furnace test, and this result was verified by subsequent electrolytic deconsolidation and acid leaching of the compact, which showed that all SiC layers were still intact. However, the deposition cups recovered significant quantities of silver, europium, and strontium. Based on comparison of calculated compact inventories at the end of irradiation versus analysis of these fission products released to the deposition cups and furnace internals, the minimum estimated fractional losses from the compact during the furnace test were 1.9 × 10{sup −2} for silver, 1.4 × 10{sup −3} for europium, and 1.1 × 10{sup −5} for strontium. Other post-irradiation examination of AGR-1 compacts indicates that similar fractions of europium and silver may have already been released by the intact coated particles during irradiation, and it is therefore likely that the detected fission products released from the compact in this 1600 °C furnace test were from residual fission products in the matrix. Gamma analysis of coated particles deconsolidated from the compact after the heating test revealed that silver content within each particle varied considerably; a result that is probably not related to the furnace test, because it has also been observed in other as

  15. The co-evolution of alternative fuel infrastructure and vehicles: A study of the experience of Argentina with compressed natural gas

    Energy Technology Data Exchange (ETDEWEB)

    Collantes, Gustavo, E-mail: gustavo.collantes@commerce.wa.go [Renergh Consulting and Department of Commerce, State of Washington, 2001 6th Ave, Suite 2600, Seattle, WA 98121 (United States); Melaina, Marc W. [National Renewable Energy Laboratory (United States)

    2011-02-15

    In a quest for strategic and environmental benefits, the developed countries have been trying for many years to increase the share of alternative fuels in their transportation fuel mixes. They have met very little success though. In this paper, we examine the experience of Argentina with compressed natural gas. We conducted interviews with a wide range of stakeholders and analyzed econometrically data collected in Argentina to investigate the factors, economic, political, and others that determined the high rate of adoption of this fuel. A central objective of this research was to identify lessons that could be useful to developed countries in their efforts to deploy alternative fuel vehicles. We find that fuel price regulation was a significant determinant of the adoption of compressed natural gas, while, contrary to expectations, government financing of refueling infrastructure was minimal. - Research Highlights: {yields}The broad scale adoption of CNG for transportation in Argentina was initiated by a market demand for an effective fuel that was priced at a significantly lower level compared to the mainstream alternatives. {yields}The Argentine played a marginal role in the development of refueling infrastructure. {yields}The role of the government focused on sending clear signals to the marketplace and developing effective codes and standards. {yields}Consumers willingness to switch to CNG increases as state of the economy deteriorates and disposable incomes decrease.

  16. THE MISSION AND ACCOMPLISHMENTS FROM DOE’S FUEL CYCLE RESEARCH AND DEVELOPMENT (FCRD) ADVANCED FUELS CAMPAIGN

    Energy Technology Data Exchange (ETDEWEB)

    J. Carmack; L. Braase; F. Goldner

    2015-09-01

    The mission of the Advanced Fuels Campaign (AFC) is to perform Research, Development, and Demonstration (RD&D) activities for advanced fuel forms (including cladding) to enhance the performance and safety of the nation’s current and future reactors, enhance proliferation resistance of nuclear fuel, effectively utilize nuclear energy resources, and address the longer-term waste management challenges. This includes development of a state of the art Research and Development (R&D) infrastructure to support the use of a “goal oriented science based approach.” AFC uses a “goal oriented, science based approach” aimed at a fundamental understanding of fuel and cladding fabrication methods and performance under irradiation, enabling the pursuit of multiple fuel forms for future fuel cycle options. This approach includes fundamental experiments, theory, and advanced modeling and simulation. One of the most challenging aspects of AFC is the management, integration, and coordination of major R&D activities across multiple organizations. AFC interfaces and collaborates with Fuel Cycle Technologies (FCT) campaigns, universities, industry, various DOE programs and laboratories, federal agencies (e.g., Nuclear Regulatory Commission [NRC]), and international organizations. Key challenges are the development of fuel technologies to enable major increases in fuel performance (safety, reliability, power and burnup) beyond current technologies, and development of characterization methods and predictive fuel performance models to enable more efficient development and licensing of advanced fuels. Challenged with the research and development of fuels for two different reactor technology platforms, AFC targeted transmutation fuel development and focused ceramic fuel development for Advanced LWR Fuels.

  17. Simulation with GOTHIC of experiments Oxidation of fuel in Air; Simulacion con GOTHIC de Experimentos de Oxidacion de Combustible en Aire

    Energy Technology Data Exchange (ETDEWEB)

    Martinez-Murillo Mendez, J. C.

    2012-07-01

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

  18. Welding procedures used in the fabrication of fuel elements for the DON Reactor exponential experiment; La soldadura en la fabricacion de elementos combustibles destinados a una experiencia exponencial

    Energy Technology Data Exchange (ETDEWEB)

    Diaz Beltran, A.; Jaraiz Franco, E.; Rivas Diaz, M. de las

    1965-07-01

    This exponential experiment required 74 units (37 loaded with UO{sub 2} and 37 with UC) to simulate the Reactor fuel channels. Each unit was enclosed in a tube similar to the calandria ones. It contained the pressure tube, the shroud and the 19 rods cluster. Within the pressure tube, in touch with the elements, was the organic liquid. (Author)

  19. Two-Dimensional Mapping of the Calculated Fission Power for the Full-Size Fuel Plate Experiment Irradiated in the Advanced Test Reactor

    Science.gov (United States)

    Chang, G. S.; Lillo, M. A.

    2009-08-01

    The National Nuclear Security Administrations (NNSA) Reduced Enrichment for Research and Test Reactors (RERTR) program assigned to the Idaho National Laboratory (INL) the responsibility of developing and demonstrating high uranium density research reactor fuel forms to enable the use of low enriched uranium (LEU) in research and test reactors around the world. A series of full-size fuel plate experiments have been proposed for irradiation testing in the center flux trap (CFT) position of the Advanced Test Reactor (ATR). These full-size fuel plate tests are designated as the AFIP tests. The AFIP nominal fuel zone is rectangular in shape having a designed length of 21.5-in (54.61-cm), width of 1.6-in (4.064-cm), and uniform thickness of 0.014-in (0.03556-cm). This gives a nominal fuel zone volume of 0.482 in3 (7.89 cm3) per fuel plate. The AFIP test assembly has two test positions. Each test position is designed to hold 2 full-size plates, for a total of 4 full-size plates per test assembly. The AFIP test plates will be irradiated at a peak surface heat flux of about 350 W/cm2 and discharged at a peak U-235 burn-up of about 70 at.%. Based on limited irradiation testing of the monolithic (U-10Mo) fuel form, it is desirable to keep the peak fuel temperature below 250°C to achieve this, it will be necessary to keep plate heat fluxes below 500 W/cm2. Due to the heavy U-235 loading and a plate width of 1.6-in (4.064-cm), the neutron self-shielding will increase the local-to-average-ratio (L2AR) fission power near the sides of the fuel plates. To demonstrate that the AFIP experiment will meet the ATR safety requirements, a very detailed 2-dimensional (2D) Y-Z fission power profile was evaluated in order to best predict the fuel plate temperature distribution. The ability to accurately predict fuel plate power and burnup are essential to both the design of the AFIP tests as well as evaluation of the irradiated fuel performance. To support this need, a detailed MCNP Y

  20. Modeling the influence of precursor volatility and molecular structure on secondary organic aerosol formation using evaporated fuel experiments

    Directory of Open Access Journals (Sweden)

    S. H. Jathar

    2013-09-01

    Full Text Available We use SOA production data from an ensemble of evaporated fuels to test various SOA formation models. Except for gasoline, traditional SOA models focusing exclusively on volatile species in the fuels under-predict the observed SOA formation. These models can be improved dramatically by accounting for lower volatility species, but at the cost of a large set of free parameters. In contrast, a SOA model based only on the volatility of the precursor, starting with the volatility distribution of the evaporated fuels and optimized for the volatility reduction of first-generation products, reasonably reproduces the observed SOA formation with relatively few free parameters. The exceptions are exotic fuels such as Fischer-Tropsch fuels that expose the central assumption of the volatility based model that most emissions consist of complex mixtures displaying reasonably average behavior. However, for the vast majority of fuels, the volatility based model performs well.

  1. Distribution Reliability of the Energy Supply Chain

    Directory of Open Access Journals (Sweden)

    Hidayat Rachmad

    2016-01-01

    Full Text Available Reliability of an oil fuel distribution system can be achieved by considering multiple attributes. Load-point indicators consisted of the frequency of failures, average duration of an outage and average annual outage time. Indicators of system performance were SAIFI and SAIDI and the method of the study was the Learning Vector Quantization (LVQ. Decisions were made by considering the multi-attribute oil fuel distribution system to determine high reliability, which was simulated on the agent. The use of agents in the simulation to determine the oil fuel distribution system reliability helped visualize the oil fuel distribution in meeting the quality of fuels received by consumers and made it easier to learn the problems faced by oil fuel distribution.

  2. Fuel sensor-less control of a liquid feed fuel cell under dynamic loading conditions for portable power sources (I)

    Energy Technology Data Exchange (ETDEWEB)

    Chang, C.L. [Institute of Nuclear Energy Research (INER), No. 1000, Wunhua Road, Jiaan Village, Longtan Township, Taoyuan County 32546 (China); National Taiwan University (China); Chen, C.Y.; Liou, D.H. [Institute of Nuclear Energy Research (INER), No. 1000, Wunhua Road, Jiaan Village, Longtan Township, Taoyuan County 32546 (China); Sung, C.C. [National Taiwan University (China)

    2008-07-15

    This work presents a novel fuel sensor-less control scheme for a liquid feed fuel cell system that operates under dynamic loading conditions and is suitable for portable power sources. The proposed technique utilizes the operating characteristics of a fuel cell, such as voltage, current and power, to control the supply of liquid fuel and regulate its concentration. As verified by systematic experiments, this scheme controls effectively the supply of fuel under dynamic loading conditions and pushes the system toward higher power output. The primary features and advantages of sensor-less fuel control are as follows. When the fuel concentration sensor is excluded, the cost of a liquid feed fuel cell system is decreased and system volume and weight are reduced, thereby increasing specific energy density and design simplicity, and shortening system response time. Notably, temperature compensation for measurement data is unnecessary. With a decreased number of components, the control scheme improves durability and reliability of liquid feed fuel cells. These advantages will help commercialization of liquid feed fuel cells as portable power sources. (author)

  3. SunLine Transit Agency Advanced Technology Fuel Cell Bus Evaluation: First Results Report

    Energy Technology Data Exchange (ETDEWEB)

    Eudy, L.; Chandler, K.

    2011-03-01

    This report describes operations at SunLine Transit Agency for their newest prototype fuel cell bus and five compressed natural gas (CNG) buses. In May 2010, SunLine began operating its sixth-generation hydrogen fueled bus, an Advanced Technology (AT) fuel cell bus that incorporates the latest design improvements to reduce weight and increase reliability and performance. The agency is collaborating with the U.S. Department of Energy's (DOE) National Renewable Energy Laboratory (NREL) to evaluate the bus in revenue service. This report provides the early data results and implementation experience of the AT fuel cell bus since it was placed in service.

  4. The MARINE experiment: Irradiation of sphere-pac fuel and pellets of UO{sub 2−x} for americium breeding blanket concept

    Energy Technology Data Exchange (ETDEWEB)

    D' Agata, E., E-mail: elio.dagata@ec.europa.eu [European Commission, Joint Research Centre, Institute for Energy and Transport, P.O. Box 2, NL-1755 ZG Petten (Netherlands); Hania, P.R. [Nuclear Research and Consultancy Group, P.O. Box 25, NL-1755 ZG Petten (Netherlands); Freis, D.; Somers, J. [European Commission, Joint Research Centre, Institute for Transuranium Elements, P.O. Box 2340, D-76125 Karlsruhe (Germany); Bejaoui, S. [Commissariat à l’Energie Atomique et aux Energies Alternatives, DEN/DEC, F-13108 St. Paul lez Durance Cedex (France); Charpin, F.F.; Baas, P.J.; Okel, R.A.F.; Til, S. van [Nuclear Research and Consultancy Group, P.O. Box 25, NL-1755 ZG Petten (Netherlands); Lapetite, J.-M. [European Commission, Joint Research Centre, Institute for Energy and Transport, P.O. Box 2, NL-1755 ZG Petten (Netherlands); Delage, F. [Commissariat à l’Energie Atomique et aux Energies Alternatives, DEN/DEC, F-13108 St. Paul lez Durance Cedex (France)

    2017-01-15

    Highlights: • MARINE is designed to check the behaviour of MABB sphere-pac concept. • MABB sphere-pac are compared with MABB pellet. • Swelling and helium release behaviour will be the main output of the experiment. • An experiment to check sphere-pac MADF fuel behaviour has been already performed. - Abstract: Americium is a strong contributor to the long term radiotoxicity of high activity nuclear waste. Transmutation by irradiation in nuclear reactors of long-lived nuclides like {sup 241}Am is therefore an option for the reduction of radiotoxicity and heat production of waste packages to be stored in a repository. The MARINE irradiation experiment is the latest of a series of European experiments on americium transmutation (e.g. EFTTRA-T4, EFTTRA-T4bis, HELIOS, MARIOS, SPHERE) performed in the High Flux Reactor (HFR). The MARINE experiment is developed and carried out in the framework of the collaborative research project PELGRIMM of the EURATOM 7th Framework Programme (FP7). During the past years of experimental works in the field of transmutation and tests of innovative nuclear fuels, the release or trapping of helium as well as swelling have been shown to be the key issues for the design of such kind of fuel both as drivers and even more for Am-bearing blanket targets (due to the higher Am contents). The main objective of the MARINE experiment is to study the in-pile behaviour of uranium oxide fuel containing 13% of americium and to compare the behaviour of sphere-pac versus pellet fuel, in particular the role of microstructure and temperature on fission gas release and He on fuel swelling. The MARINE experiment will be irradiated in 2016 in the HFR in Petten (The Netherlands) and is expected to be completed in spring 2017. This paper discusses the rationale and objective of the MARINE experiment and provides a general description of its design for which some innovative features have been adopted.

  5. Modeling: driving fuel cells

    Directory of Open Access Journals (Sweden)

    Michael Francis

    2002-05-01

    Fuel cells were invented in 1839 by Sir William Grove, a Welsh judge and gentleman scientist, as a result of his experiments on the electrolysis of water. To put it simply, fuel cells are electrochemical devices that take hydrogen gas from fuel, combine it with oxygen from the air, and generate electricity and heat, with water as the only by-product.

  6. Pyrometric fuel particle measurements in pressurized reactors

    Energy Technology Data Exchange (ETDEWEB)

    Joutsenoja, T.; Stenberg, J.; Hernberg, R.; Aho, M.; Richard, J.-R.; Mallet, C.; Bonn, B. [Tampere University of Technology, Tampere (Finland). Dept. of Physics

    1998-12-31

    A fibre-optic two-colour pyrometric technique for fuel particle temperature and size measurement is modified and applied to three pressurised reactors of different type in Finland, Germany and France. A modification of the pyrometric method for simultaneous in situ measurement of the temperature and size of individual pulverised coal particles at the pressurised entrained flow reactor of VTT Energy in Jyvaskyla was developed and several series of measurements were made in order to study the effects of oxygen concentration (3-30 vol%) and pressure (0.2-1.0 MPa) on the particle temperature. The fuels used in the experiments were Westerholt, Polish and Gottelborn hvb coals. Gardanne lignite and Niederberg anthracite. The initial nominal fuel particle size varied in the experiments from 70 to 250 {mu}m and the gas temperature was typically 1173 K. For the anthracite also the effects of gas temperature (1073-1423 K) and CO{sub 2} concentration (6-80 vol%) were studied. In Orleans a fibre-optic pyrometric device was installed to a pressurised thermogravimetric reactor of CNRS and the two-colour temperatures of fuel samples were measured. The fuel in the experiments was pulverized Gottelborn char. The reliability of optical temperature measurement in this particular application was analysed. In Essen a fibre-optic pyrometric technique that is capable to measure bed and fuel particle temperatures was applied to an atmospheric fluidised bed reactor of DMT. The effects of oxygen concentration (3-8 vol%) and bed temperature (1123-1193 K) on the fuel particle temperature were studied. The fuels in these were Westerholt coal and char and EBV-coal. 17 refs., 21 figs., 3 tabs.

  7. Pyrometric fuel particle measurements in pressurised reactors

    Energy Technology Data Exchange (ETDEWEB)

    Hernberg, R.; Joutsenoja, T. [Tampere Univ. of Technology (Finland)

    1997-10-01

    A fibre-optic two-colour pyrometric technique for fuel particle temperature and size measurement is modified and applied to three pressurised reactors of different type in Finland, Germany and France. A modification of the pyrometric method for simultaneous in situ measurement of the temperature and size of individual pulverised coal particles at the pressurised entrained flow reactor of VTT Energy in Jyvaeskylae was developed and several series of measurements were made in order to study the effects of oxygen concentration (3-30 vol%) and pressure (0.2-1.0 MPa) on the particle temperature. The fuels used in the experiments were Westerholt, Polish and Goettelborn hvb coals, Gardanne lignite and Niederberg anthracite. The initial nominal fuel particle size varied in the experiments from 70 to 250 ,{mu}m and the gas temperature was typically 1173 K. For the anthracite also the effects of gas temperature (1073-1423K) and CO{sub 2} concentration (6-80 vol%) were studied. In Orleans a fibreoptic pyrometric device was installed to a pressurised thermogravimetric reactor of CNRS and the two-colour temperatures of fuel samples were measured. The fuel in the experiments was pulverised Goettelborn char. The reliability of optical temperature measurement in this particular application was analysed. In Essen a fibre-optic pyrometric technique that is capable to measure bed and fuel particle temperatures was applied to an atmospheric fluidised bed reactor of DMT. The effects of oxygen concentration (3-8 vol%) and bed temperature (1123-1193 K) on the fuel particle temperature were studied. The fuels in these were Westerholt coal and char and EBV-coal. Some results of these measurements are presented. The project belonged to EU`s Joule 2 extension research programme (contract JOU2-CT93-0331). (orig.)

  8. 活门组件综合试验器研制%Design of Fuel Static Experiment Comprehensive Platform

    Institute of Scientific and Technical Information of China (English)

    王野牧; 谌超逸

    2014-01-01

    活门组件综合试验器是专门为检测飞机活门组件和独立活门的性能指标而开发的一种新型试验设备。针对试验器的基本技术要求,给出了该试验器液压控制系统原理图、电气控制系统硬件组成框图及软件系统的工作流程图,并着重就开发中所遇到的重点、难点进行了较详细的介绍,同时验证了设计方案的正确性。%Fuel static experiment comprehensive platform is a new test equipment,specially designed for testing performance of the combination valve and the independent valve. Aiming at the basic technical requirements,the principle diagram of hydraulic control system,hardware composition block diagram of electrical control system and work flow chart of software system for this comprehensive platform were given. The emphases and difficulties encountered in the developing were introduced in detail. The correctness of the de-sign was verified at last.

  9. Characterization of a Solid Oxide Fuel Cell Gas Turbine Hybrid System Based on a Factorial Design of Experiments Using Hardware Simulation

    Energy Technology Data Exchange (ETDEWEB)

    Restrepo, Bernardo; Banta, Larry E; Tucker, David

    2012-10-01

    A full factorial experimental design and a replicated fractional factorial design were carried out using the Hybrid Performance (HyPer) project facility installed at the National Energy Technology Laboratory (NETL), U.S. Department of Energy to simulate gasifer/fuel cell/turbine hybrid power systems. The HyPer facility uses hardware in the loop (HIL) technology that couples a modified recuperated gas turbine cycle with hardware driven by a solid oxide fuel cell model. A 34 full factorial design (FFD) was selected to study the effects of four factors: cold-air, hot-air, bleed-air bypass valves, and the electric load on different parameters such as cathode and turbine inlet temperatures, pressure and mass flow. The results obtained, compared with former results where the experiments were made using one-factor-at-a-time (OFAT), show that no strong interactions between the factors are present in the different parameters of the system. This work also presents a fractional factorial design (ffd) 34-2 in order to analyze replication of the experiments. In addition, a new envelope is described based on the results of the design of experiments (DoE), compared with OFAT experiments, and analyzed in an off-design integrated fuel cell/gas turbine framework. This paper describes the methodology, strategy, and results of these experiments that bring new knowledge concerning the operating state space for this kind of power generation system.

  10. EPRI fuel cladding integrity program

    Energy Technology Data Exchange (ETDEWEB)

    Yang, R. [Electric Power Research Institute, Palo Alto, CA (United States)

    1997-01-01

    The objectives of the EPRI fuel program is to supplement the fuel vendor research to assure that utility economic and operational interests are met. To accomplish such objectives, EPRI has conducted research and development efforts to (1) reduce fuel failure rates and mitigate the impact of fuel failures on plant operation, (2) provide technology to extend burnup and reduce fuel cycle cost. The scope of R&D includes fuel and cladding. In this paper, only R&D related to cladding integrity will be covered. Specific areas aimed at improving fuel cladding integrity include: (1) Fuel Reliability Data Base; (2) Operational Guidance for Defective Fuel; (3) Impact of Water Chemistry on Cladding Integrity; (4) Cladding Corrosion Data and Model; (5) Cladding Mechanical Properties; and (6) Transient Fuel Cladding Response.

  11. Reliability Engineering

    CERN Document Server

    Lazzaroni, Massimo

    2012-01-01

    This book gives a practical guide for designers and users in Information and Communication Technology context. In particular, in the first Section, the definition of the fundamental terms according to the international standards are given. Then, some theoretical concepts and reliability models are presented in Chapters 2 and 3: the aim is to evaluate performance for components and systems and reliability growth. Chapter 4, by introducing the laboratory tests, puts in evidence the reliability concept from the experimental point of view. In ICT context, the failure rate for a given system can be

  12. Six years working experience of the Marcoule plant for treatment of irradiated fuel; Experience de 6 annees de fonctionnement de l'usine de retraitement de Marcoule

    Energy Technology Data Exchange (ETDEWEB)

    Jouannaud, C. [CEA Marcoule, Centre de Production de Plutonium, 30 (France)

    1964-07-01

    The irradiated fuel treatment plant at Marcoule began treating rods from the pile G 1 in July 1958. These six years experience of the plant in operation have led to the confirmation or revision of the original ideas concerning the process as well as the technology or methods of exploitation. The process as a whole has suffered little modification, the performances having proved better than originally foreseen; the only alterations made were justified by greater simplicity of operation, better nuclear security (criticality) or for technological reasons. The processes of plutonium reduction from valency IV to valency III by uranium IV, and of concentration of fission product solutions in the presence of formaldehyde, have always given complete satisfaction. The initial concept of direct maintenance of the installations has been justified by experience. Certain maintenance jobs, originally considered impossible after the start of operations, have proved feasible and have been carried out under acceptable conditions; a number of examples are given. From experience it has been possible to define optimal conditions for the design of these installations such as to provide a maximum in robustness and ease of maintenance. The advantages of continuously-operating equipment have been shown. Certain installations have been altered in accordance with these new ideas. Analytical checking in the laboratory has been profoundly modified, and the plans adopted are such that complete safety in work on radioactive solutions is compatible with a very good working speed. Experience has also shown the advantages of having a group on the spot to carry out short-term applied studies. Finally, a strict working discipline and excellent collaboration with the radiation protection service have enabled us to reach the end of these six years, during some of which the exploitation was intensive, without irradiation accident. (authors) [French] L'usine de traitement des combustibles irradies

  13. Innovative Fuel Cell Health Monitoring IC Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Energy storage devices, including fuel cells, are needed to enable future robotic and human exploration missions. Historically, the reliability of the fuel cells has...

  14. On the Ability of Ascends to Constrain Fossil Fuel, Ocean and High Latitude Emissions: Flux Estimation Experiments

    Science.gov (United States)

    Crowell, S.; Kawa, S. R.; Hammerling, D.; Moore, B., III; Rayner, P. J.

    2014-12-01

    In Hammerling et al., 2014 (H14) the authors demonstrated a geostatistical method for mapping satellite estimates of column integrated CO2 mixing ratio, denoted XCO2, that incorporates the spatial variability in satellite-measured XCO2 as well as measurement precision. The goal of the study was to determine whether the Active Sensing of CO2 over Nights, Days and Seasons (ASCENDS) mission would be able to detect changes in XCO2 given changes in the underlying fluxes for different levels of instrument precision. Three scenarios were proposed: a flux-neutral shift in fossil fuel emissions from Europe to China (shown in the figure); a permafrost melting event; interannual variability in the Southern Oceans. The conclusions of H14 were modest but favorable for detectability in each case by ASCENDS given enough observations and sufficient precision. These signal detection experiments suggest that ASCENDS observations, together with a chemical transport model and data assimilation methodology, would be sufficient to provide quality estimates of the underlying surface fluxes, so long as the ASCENDS observations are precise enough. In this work, we present results that bridge the gap between the previous signal detection work by [Hammerling et al., 2014] and the ability of transport models to recover flux perturbations from ASCENDS observations utilizing the TM5-4DVAR data assimilation system. In particular, we will explore the space of model and observational uncertainties that will yield useful scientific information in each of the flux perturbation scenarios. This work will give a sense of the ability of ASCENDS to answer key questions about some of the foremost questions in carbon cycle science today. References: Hammerling, D., Kawa, S., Schaefer, K., and Michalak, A. (2014). Detectability of CO2 flux signals by a space-based lidar mission. Submitted.

  15. Design, Fabrication, and Operation of Innovative Microalgae Culture Experiments for the Purpose of Producing Fuels: Final Report, Phase I

    Energy Technology Data Exchange (ETDEWEB)

    1985-01-01

    A conceptual design was developed for a 1000-acre (water surface) algae culture facility for the production of fuels. The system is modeled after the shallow raceway system with mixing foils that is now being operated at the University of Hawaii. A computer economic model was created to calculate the discounted breakeven price of algae or fuels produced by the culture facility. A sensitivity analysis was done to estimate the impact of changes in important biological, engineering, and financial parameters on product price.

  16. Fuel services; Servicios de combustible

    Energy Technology Data Exchange (ETDEWEB)

    Marta, H.; Alvarez, P.; Jimenez, J.

    2006-07-01

    Refuelling outages comprise a number of maintenance tasks scheduled long in advance to assure a reliable operation throughout the next cycle and, in the long run, a safer and more efficient plant. Most of these tasks are routine service of mechanical and electrical system and likewise fuel an be considered a critical component as to handling, inspection, cleaning and repair. ENUSA-ENWESA AIE has been working in this area since 1995 growing from fuel repair to a more integrated service that includes new and spent fuel handling, inserts, failed fuel rod detection systems, ultrasonic fuel cleaning,fuel repair and a comprehensive array of inspection and tests related to the reliability of the mechanical components in the fuel assembly, all this, performed in compliance with quality, safety, health physics and any other nuclear standard. (Author)

  17. Health Services OutPatient Experience questionnaire: factorial validity and reliability of a patient-centered outcome measure for outpatient settings in Italy

    Directory of Open Access Journals (Sweden)

    Coluccia A

    2014-09-01

    Full Text Available Anna Coluccia, Fabio Ferretti, Andrea PozzaDepartment of Medical Sciences, Surgery and Neurosciences, Santa Maria alle Scotte University Hospital, University of Siena, Siena, ItalyPurpose: The patient-centered approach to health care does not seem to be sufficiently developed in the Italian context, and is still characterized by the biomedical model. In addition, there is a lack of validated outcome measures to assess outpatient experience as an aspect common to a variety of settings. The current study aimed to evaluate the factorial validity, reliability, and invariance across sex of the Health Services OutPatient Experience (HSOPE questionnaire, a short ten-item measure of patient-centeredness for Italian adult outpatients. The rationale for unidimensionality of the measure was that it could cover global patient experience as a process common to patients with a variety of diseases and irrespective of the phase of treatment course.Patients and methods: The HSOPE was compiled by 1,532 adult outpatients (51% females, mean age 59.22 years, standard deviation 16.26 receiving care in ten facilities at the Santa Maria alle Scotte University Hospital of Siena, Italy. The sample represented all the age cohorts. Twelve percent were young adults, 57% were adults, and 32% were older adults. Exploratory and confirmatory factor analyses were conducted to evaluate factor structure. Reliability was evaluated as internal consistency using Cronbach’s α. Factor invariance was assessed through multigroup analyses.Results: Both exploratory and confirmatory analyses suggested a clearly defined unidimensional structure of the measure, with all the ten items having salient loadings on a single factor. Internal consistency was excellent (α=0.95. Indices of model fit supported a single-factor structure for both male and female outpatient groups. Young adult outpatients had significantly lower scores on perceived patient-centeredness relative to older adults. No

  18. Measuring trauma and stressful events in childhood and adolescence among patients with first-episode psychosis: initial factor structure, reliability, and validity of the Trauma Experiences Checklist.

    Science.gov (United States)

    Cristofaro, Sarah L; Cleary, Sean D; Ramsay Wan, Claire; Broussard, Beth; Chapman, Colby; Haggard, Patrick J; Jananeh, Sara; Myers, Neely L; Compton, Michael T

    2013-12-15

    Past trauma and stressful events, especially in childhood and adolescence, are common among individuals with serious mental illnesses like schizophrenia. Traumatic experiences are thought to be a socio-environmental risk factor not only for poorer outcomes, but also potentially for the onset of these disorders. Because improved measurement tools are needed, we developed and studied, among 205 first-episode psychosis patients, the factor structure, internal consistency reliability, and initial validity of the Trauma Experiences Checklist (TEC), our measure of trauma and stressful events during childhood/adolescence. We assessed validity of subscales using correlations with Childhood Trauma Questionnaire-Short Form, Parental Harsh Discipline, Violence Exposure, and TEC-Informant Version scores. Exploratory factor analysis resulted in two internally consistent subscales (Cronbach's α=0.79 and 0.80, respectively), interpersonal abuse and family stress, and violence, death, and legal involvement. Scores from the former subscale were substantially associated with CTQ-SF physical, emotional, and sexual abuse (r=0.42-0.57, all p<0.001) and Violence Exposure (r=0.49, p<0.001). On the other hand, violence, death, and legal involvement scores were most highly correlated with Violence Exposure (r=0.49, p<0.001), and not with most CTQ-SF subscales. The TEC is a potentially useful tool in assessing diverse traumatic life events across various social contexts during childhood and adolescence.

  19. Fuel safety research 1999

    Energy Technology Data Exchange (ETDEWEB)

    Uetsuka, Hiroshi (ed.) [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2000-07-01

    In April 1999, the Fuel Safety Research Laboratory was newly established as a result of reorganization of the Nuclear Safety Research Center, JAERI. The laboratory was organized by combining three laboratories, the Reactivity Accident Laboratory, the Fuel Reliability Laboratory, and a part of the Sever Accident Research Laboratory. Consequently, the Fuel Safety Research Laboratory is now in charge of all the fuel safety research in JAERI. Various types of experimental and analytical researches are conducted in the laboratory by using the unique facilities such as the Nuclear Safety Research Reactor (NSRR), the Japan Material Testing Reactor (JMTR), the Japan Research Reactor 3 (JRR-3) and hot cells in JAERI. The laboratory consists of five research groups corresponding to each research fields. They are; (a) Research group of fuel behavior under the reactivity initiated accident conditions (RIA group). (b) Research group of fuel behavior under the loss-of-coolant accident conditions (LOCA group). (c) Research group of fuel behavior under the normal operation conditions (JMTR/BOCA group). (d) Research group of fuel behavior analysis (FEMAXI group). (e) Research group of FP release/transport behavior from irradiated fuel (VEGA group). This report summarizes the outline of research activities and major outcomes of the research executed in 1999 in the Fuel Safety Research Laboratory. (author)

  20. Fuel elements assembling for the DON project exponential experience; Montaje de los elementos combustibles para la experiencia exponencial del proyecto DON

    Energy Technology Data Exchange (ETDEWEB)

    Anca Abati, R. de

    1966-07-01

    It is described the fuel unit used in the DON exponential experience, the manufacturing installments and tools as well as the stages in the fabrication.These 74 elements contain each 19 cartridges loaded with synterized urania, uranium carbide and indium, gold, and manganese probes. They were arranged in calandria-like tubes and the process-tube. This last one containing a cooling liquid simulating the reactor organic. Besides being used in the DON reactor exponential experience they were used in critic essays by the substitution method in the French reactor AQUILON II. (Author) 6 refs.

  1. Expert system aids reliability

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, A.T. [Tennessee Gas Pipeline, Houston, TX (United States)

    1997-09-01

    Quality and Reliability are key requirements in the energy transmission industry. Tennessee Gas Co. a division of El Paso Energy, has applied Gensym`s G2, object-oriented Expert System programming language as a standard tool for maintaining and improving quality and reliability in pipeline operation. Tennessee created a small team of gas controllers and engineers to develop a Proactive Controller`s Assistant (ProCA) that provides recommendations for operating the pipeline more efficiently, reliably and safely. The controller`s pipeline operating knowledge is recreated in G2 in the form of Rules and Procedures in ProCA. Two G2 programmers supporting the Gas Control Room add information to the ProCA knowledge base daily. The result is a dynamic, constantly improving system that not only supports the pipeline controllers in their operations, but also the measurement and communications departments` requests for special studies. The Proactive Controller`s Assistant development focus is in the following areas: Alarm Management; Pipeline Efficiency; Reliability; Fuel Efficiency; and Controller Development.

  2. The Reliability of Estimating Ki Values for Direct, Reversible Inhibition of Cytochrome P450 Enzymes from Corresponding IC50 Values: A Retrospective Analysis of 343 Experiments.

    Science.gov (United States)

    Haupt, Lois J; Kazmi, Faraz; Ogilvie, Brian W; Buckley, David B; Smith, Brian D; Leatherman, Sarah; Paris, Brandy; Parkinson, Oliver; Parkinson, Andrew

    2015-11-01

    In the present study, we conducted a retrospective analysis of 343 in vitro experiments to ascertain whether observed (experimentally determined) values of Ki for reversible cytochrome P450 (P450) inhibition could be reliably predicted by dividing the corresponding IC₅₀ values by two, based on the relationship (for competitive inhibition) in which Ki = IC₅₀/2 when [S] (substrate concentration) = Km (Michaelis-Menten constant). Values of Ki and IC₅₀ were determined under the following conditions: 1) the concentration of P450 marker substrate, [S], was equal to Km (for IC₅₀ determinations) and spanned Km (for Ki determinations); 2) the substrate incubation time was short (5 minutes) to minimize metabolism-dependent inhibition and inhibitor depletion; and 3) the concentration of human liver microsomes was low (0.1 mg/ml or less) to maximize the unbound fraction of inhibitor. Under these conditions, predicted Ki values, based on IC₅₀/2, correlated strongly with experimentally observed Ki determinations [r = 0.940; average fold error (AFE) = 1.10]. Of the 343 predicted Ki values, 316 (92%) were within a factor of 2 of the experimentally determined Ki values, and only one value fell outside a 3-fold range. In the case of noncompetitive inhibitors, Ki values predicted from IC₅₀/2 values were overestimated by a factor of nearly 2 (AFE = 1.85; n = 13), which is to be expected because, for noncompetitive inhibition, Ki = IC₅₀ (not IC₅₀/2). The results suggest that, under appropriate experimental conditions with the substrate concentration equal to Km, values of Ki for direct, reversible inhibition can be reliably estimated from values of IC₅₀/2.

  3. Most advanced HTP fuel assembly design for EPR

    Energy Technology Data Exchange (ETDEWEB)

    Francillon, Eric [AREVA - Framatome ANP, 10 rue Juliette Recamier - 69456 Lyon Cedex 06 (France); Kiehlmann, Horst-Dieter [AREVA - Framatome ANP GmbH, P.O. Box 3220, 91050 Erlangen (Germany)

    2006-07-01

    End 2003, the Finnish electricity utility Teollisuuden Voima Oy (TVO) signed the contract for building an EPR in Olkiluoto (Finland). Mid 2004, the French electricity utility EDF selected an EPR to be built in France. In 2005, Framatome ANP, an AREVA and Siemens company, announced that they will be pursuing a design certification in the U.S. The EPR development is based on the latest PWR product lines of former Framatome (N4) and Siemens Nuklear (Konvoi). As an introductory part, different aspects of the EPR core characteristics connected to fuel assembly design are presented. It includes means of ensuring reactivity control like hybrid AIC/B4C control rod absorbers and gadolinium as burnable absorber integrated in fuel rods, and specific options for in-core instrumentation, such as Aeroball type instrumentation. Then the design requirements for the EPR fuel assembly are presented in term of very high burnup capacity, rod cladding and fuel assembly reliability. Framatome ANP fuel assembly product characteristics meeting these requirements are then described. EPR fuel assembly design characteristics benefit from the experience feedback of the latest fuel assembly products designed within Framatome ANP, leading to resistance to assembly deformation, high fuel rod restraint and prevention of handling hazards. EPR fuel assembly design features the best components composing the cornerstones of the upgraded family of fuel assemblies that FRAMATOME ANP proposes today. This family is based on a set of common characteristics and associated features, which include the HMP grid as bottom end spacer, the MONOBLOC guide tube and the Robust FUELGUARD as lower tie plate, the use of the M5 Alloy, as cladding and structure material. This fully re-crystallized, ternary Zr-Nb-O alloy produces radically improved in-reactor corrosion, very low hydrogen uptake and growth and an excellent creep behavior, which are described there. EPR fuel assembly description also includes fuel rod

  4. 3D COMSOL Simulations for Thermal Deflection of HFIR Fuel Plate in the "Cheverton-Kelley" Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Jain, Prashant K [ORNL; Freels, James D [ORNL; Cook, David Howard [ORNL

    2012-08-01

    Three dimensional simulation capabilities are currently being developed at Oak Ridge National Laboratory using COMSOL Multiphysics, a finite element modeling software, to investigate thermal expansion of High Flux Isotope Reactor (HFIR) s low enriched uranium fuel plates. To validate simulations, 3D models have also been developed for the experimental setup used by Cheverton and Kelley in 1968 to investigate the buckling and thermal deflections of HFIR s highly enriched uranium fuel plates. Results for several simulations are presented in this report, and comparisons with the experimental data are provided when data are available. A close agreement between the simulation results and experimental findings demonstrates that the COMSOL simulations are able to capture the thermal expansion physics accurately and that COMSOL could be deployed as a predictive tool for more advanced computations at realistic HFIR conditions to study temperature-induced fuel plate deflection behavior.

  5. Trace gas emissions from combustion of peat, crop residue, biofuels, grasses, and other fuels: configuration and FTIR component of the fourth Fire Lab at Missoula Experiment (FLAME-4

    Directory of Open Access Journals (Sweden)

    C. E. Stockwell

    2014-04-01

    Full Text Available During the fourth Fire Lab at Missoula Experiment (FLAME-4, October–November~2012 a~large variety of regionally and globally significant biomass fuels was burned at the US Forest Service Fire Sciences Laboratory in Missoula, Montana. The particle emissions were characterized by an extensive suite of instrumentation that measured aerosol chemistry, size distribution, optical properties, and cloud-nucleating properties. The trace gas measurements included high resolution mass spectrometry, one- and two-dimensional gas chromatography, and open-path Fourier transform infrared (OP-FTIR spectroscopy. This paper summarizes the overall experimental design for FLAME-4 including the fuel properties, the nature of the burn simulations, the instrumentation employed, and then focuses on the OP-FTIR results. The OP-FTIR was used to measure the initial emissions of 20 trace gases: CO2, CO, CH4, C2H2, C2H4, C3H6, HCHO, HCOOH, CH3OH, CH3COOH, glycolaldehyde, furan, H2O, NO, NO2, HONO, NH3, HCN, HCl, and SO2. These species include most of the major trace gases emitted by biomass burning and for several of these compounds it is the first time their emissions are reported for important fuel types. The main fuel types included: African grasses, Asian rice straw, cooking fires (open (3-stone, rocket, and gasifier stoves, Indonesian and extratropical peat, temperate and boreal coniferous canopy fuels, US crop residue, shredded tires, and trash. Comparisons of the OP-FTIR emission factors (EF and emission ratios (ER to field measurements of biomass burning verify that the large body of FLAME-4 results can be used to enhance the understanding of global biomass burning and its representation in atmospheric chemistry models.

  6. FY2015 ceramic fuels development annual highlights

    Energy Technology Data Exchange (ETDEWEB)

    Mcclellan, Kenneth James [Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)

    2015-09-22

    Key challenges for the Advanced Fuels Campaign are the development of fuel technologies to enable major increases in fuel performance (safety, reliability, power and burnup) beyond current technologies, and development of characterization methods and predictive fuel performance models to enable more efficient development and licensing of advanced fuels. Ceramic fuel development activities for fiscal year 2015 fell within the areas of 1) National and International Technical Integration, 2) Advanced Accident Tolerant Ceramic Fuel Development, 3) Advanced Techniques and Reference Materials Development, and 4) Fabrication of Enriched Ceramic Fuels. High uranium density fuels were the focus of the ceramic fuels efforts. Accomplishments for FY15 primarily reflect the prioritization of identification and assessment of new ceramic fuels for light water reactors which have enhanced accident tolerance while also maintaining or improving normal operation performance, and exploration of advanced post irradiation examination techniques which will support more efficient testing and qualification of new fuel systems.

  7. FY2016 Ceramic Fuels Development Annual Highlights

    Energy Technology Data Exchange (ETDEWEB)

    Mcclellan, Kenneth James [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-01-24

    Key challenges for the Advanced Fuels Campaign are the development of fuel technologies to enable major increases in fuel performance (safety, reliability, power and burnup) beyond current technologies, and development of characterization methods and predictive fuel performance models to enable more efficient development and licensing of advanced fuels. Ceramic fuel development activities for fiscal year 2016 fell within the areas of 1) National and International Technical Integration, 2) Advanced Accident Tolerant Ceramic Fuel Development, 3) Advanced Techniques and Reference Materials Development, and 4) Fabrication of Enriched Ceramic Fuels. High uranium density fuels were the focus of the ceramic fuels efforts. Accomplishments for FY16 primarily reflect the prioritization of identification and assessment of new ceramic fuels for light water reactors which have enhanced accident tolerance while also maintaining or improving normal operation performance, and exploration of advanced post irradiation examination techniques which will support more efficient testing and qualification of new fuel systems.

  8. Fuel flexibility for advanced gas turbines with an output of up to 15 MW: requirements, design and experiences; Brenngasflexibilitt fortschrittlicher Gasturbinen im Leistungssegment bis 15 MW: Anforderungen - Designkonzept-Erfahrungen

    Energy Technology Data Exchange (ETDEWEB)

    Rainer Kurz; Chaur Wen; Luke H. Cowell; John C.Y. Lee [Solar Turbines Incorporated, San Diego, CA (United States)

    2007-10-15

    Industrial gas turbines can be operated with a number of different gas and liquid fuels and at the same time maintain low levels of pollutants. At present the use of LNG (liquefied natural gas) and gas turbine operation using fuel gas from various sources and in various compositions are much discussed. The influence of fuel composition on the production of pollutants and the reliable operation of the combustion system is discussed and measures for preventing problems ahead of projects are explained. Gaseous fuels only are considered including natural gases, liquefied petroleum gas, coke oven gas, landfill gas: coal mine methane; coal bed methane and air-blown and oxy-blown coal gas. 13 refs., 8 figs.

  9. Microelectronics Reliability

    Science.gov (United States)

    2017-01-17

    convey any rights or permission to manufacture, use, or sell any patented invention that may relate to them. This report was cleared for public release...testing for reliability prediction of devices exhibiting multiple failure mechanisms. Also presented was an integrated accelerating and measuring ...13  Table 2  T, V, F and matrix versus  measured  FIT

  10. Fuel performance annual report for 1990. Volume 8

    Energy Technology Data Exchange (ETDEWEB)

    Preble, E.A.; Painter, C.L.; Alvis, J.A.; Berting, F.M.; Beyer, C.E.; Payne, G.A. [Pacific Northwest Lab., Richland, WA (United States); Wu, S.L. [Nuclear Regulatory Commission, Washington, DC (United States). Div. of Systems Technology

    1993-11-01

    This annual report, the thirteenth in a series, provides a brief description of fuel performance during 1990 in commercial nuclear power plants. Brief summaries of fuel design changes, fuel surveillance programs, fuel operating experience and trends, fuel problems high-burnup fuel experience, and items of general significance are provided . References to additional, more detailed information, and related NRC evaluations are included where appropriate.

  11. Fuel performance annual report for 1989

    Energy Technology Data Exchange (ETDEWEB)

    Bailey, W.J.; Berting, F.M. (Pacific Northwest Lab., Richland, WA (United States)); Wu, S. (Nuclear Regulatory Commission, Washington, DC (United States). Div. of Systems Technology)

    1992-06-01

    This annual report, the twelfth in a series, provides a brief description of fuel performance during 1989 in commercial nuclear power plants and an indication of trends. Brief summaries of fuel design changes, fuel surveillance programs, fuel operating experience, fuel problems, high-burnup fuel experience, and items of general significance are provided. References to more detailed information and related US Nuclear Regulatory Commission evaluations are included.

  12. Fuel performance annual report for 1986

    Energy Technology Data Exchange (ETDEWEB)

    Bailey, W.J.; Wu, S.

    1988-03-01

    This annual report, the ninth in a series, provides a brief description of fuel performance during 1986 in commercial nuclear power plants and an indication of trends. Brief summaries of fuel design changes, fuel surveillance programs, fuel operating experience, fuel problems, high-burnup fuel experience, and items of general significance are provided. References to more detailed information and related U.S. Nuclear Regulatory Commission evaluations are included. 550 refs., 12 figs., 31 tabs.

  13. Experiments for Aviation Fuel Pollution in a Junction of Three Branches%航空燃油污染在三通管路的分布试验

    Institute of Scientific and Technical Information of China (English)

    蔡伟; 周洲; Nicolas Riviere

    2013-01-01

    Aviation fuel pollution is the one of the most important factors in fuel system failure, so fuel flow debit and quality are the parameters for real-time monitoring. For studying pollution distribution in a junction of three branches, a series of experiments with distilled water, are designsed by using measured pH to determine the concentration and then integrate the flow debit. The experiment in a single straight channel shows that the chosen method is fairly acceptable the debit and transverse diffusion coefficient are consistent with the theory The experiments in a junction of three branches prove that the flow is three-dimensional with characteristics of turbulence flow field, and that the dividing line between polluted fuel and unpolluted fuel is not so clear. Meanwhile, the process of longitudinal diffusion, transverse diffusion and vertical diffusion can be studied.%航空燃油污染对于整个燃油系统故障有举足轻重的地位.燃油流量以及质量是实时监测的重要参数.对于三支路交叉管道的燃油污染分布情况,设计了以蒸馏水为模拟介质,通过pH测定浓度进而得到流量的系列试验.单直管道的试验表明所选方法是可行的,流量和横向扩散系数都与理论保持一致.三支路交叉管道的试验则证明交叉混合区流场的三维湍流特性,以及已污染和未污染燃油之间的分界线的动态不确定性;同时可模拟出流向扩散、横向扩散以及纵向扩散的进程.

  14. Kiln process impact of alternative solid fuel combustion in the cement kiln main burner - Mathematical modelling and full-scale experiment

    OpenAIRE

    Ariyaratne, Hiromi Wijesinghe; Melaaen, Morten Christian; Tokheim, Lars André; Manjula, Edirisinghe V. P. J.

    2014-01-01

    Increased use of alternative fuels in cement kilns is a trend in the world. However, replacing fossil fuels like coal with different alternative fuels will give various impacts on the overall kiln process due to the fuel characteristics. Hence, it is important to know to what extent the fossil fuels can be replaced by different alternative fuels without severely changing process conditions, product quality or emissions. In the present study, a mass and energy balance for the combustion of dif...

  15. Oxygen reduction activity of Pt and Pt Co-alloy catalysts: A comparison between kinetic measurements and polymer electrolyte fuel cell experiments

    Energy Technology Data Exchange (ETDEWEB)

    Paulus, U.A.; Draschil, C.; Schmidt, T.J. [PSI and Lawrence Berkeley National Lab (United States); Stamenkovic, V. [Lawrence Berkeley National Lab (United States); Markovic, N.M. [Lawrence Berkeley National Lab (United States); Ross, P.N. [Lawrence Berkeley National Lab (United States); Scherer, G.G.

    2002-03-01

    The oxygen reduction reaction (orr) has been studied on various carbon supported Pt Co alloys in comparison to carbon supported platinum in perchloric acid. The applied thin film rotating ring-disk electrode (rrde) technique allows both the investigation of the orr and their kinetic analysis and in parallel the detection and quantification of the amount of peroxide produced during the orr. Polymer Electrolyte Fuel cell (PEFC) experiments using commercially available gas diffusion electrodes (gdes) with Pt/C and Pt Co/C respectively as active layers were carried out to investigate the above characterized catalysts under real PEFC conditions. (author)

  16. Identification and evaluation of alternatives for the disposition of fluoride fuel and flush salts from the molten salt reactor experiment at Oak Ridge National Laboratory, Oak Ridge, Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-08-15

    This document presents an initial identification and evaluation of the alternatives for disposition of the fluoride fuel and flush salts stored in the drain tanks at the Molten Salt Reactor Experiment (MSRE) at Oak Ridge National Laboratory (ORNL). It will serve as a resource for the U.S. Department of Energy contractor preparing the feasibility study for this activity under the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA). This document will also facilitate further discussion on the range of credible alternatives, and the relative merits of alternatives, throughout the time that a final alternative is selected under the CERCLA process.

  17. STEM-EDS analysis of fission products in neutron-irradiated TRISO fuel particles from AGR-1 experiment

    Science.gov (United States)

    Leng, B.; van Rooyen, I. J.; Wu, Y. Q.; Szlufarska, I.; Sridharan, K.

    2016-07-01

    Historic and recent post-irradiation-examination from the German AVR and Advanced Gas Reactor Fuel Development and Qualification Project have shown that 110 m Ag is released from intact tristructural isotropic (TRISO) fuel. Although TRISO fuel particle research has been performed over the last few decades, little is known about how metallic fission products are transported through the SiC layer, and it was not until March 2013 that Ag was first identified in the SiC layer of a neutron-irradiated TRISO fuel particle. The existence of Pd- and Ag-rich grain boundary precipitates, triple junction precipitates, and Pd nano-sized intragranular precipitates in neutron-irradiated TRISO particle coatings was investigated using Scanning Transmission Electron Microscopy and Energy Dispersive Spectroscopy analysis to obtain more information on the chemical composition of the fission product precipitates. A U-rich fission product honeycomb shape precipitate network was found near a micron-sized precipitate in a SiC grain about ∼5 μm from the SiC-inner pyrolytic carbon interlayer, indicating a possible intragranular transport path for uranium. A single Ag-Pd nano-sized precipitate was found inside a SiC grain, and this is the first research showing such finding in irradiated SiC. This finding may possibly suggest a possible Pd-assisted intragranular transport mechanism for Ag and may be related to void or dislocation networks inside SiC grains. Preliminary semi-quantitative analysis indicated the micron-sized precipitates to be Pd2Si2U with carbon existing inside these precipitates. However, the results of such analysis for nano-sized precipitates may be influenced by the SiC matrix. The results reported in this paper confirm the co-existence of Cd with Ag in triple points reported previously.

  18. NASA Alternative Aviation Fuel Research

    Science.gov (United States)

    Anderson, B. E.; Beyersdorf, A. J.; Thornhill, K. L., II; Moore, R.; Shook, M.; Winstead, E.; Ziemba, L. D.; Crumeyrolle, S.

    2015-12-01

    We present an overview of research conducted by NASA Aeronautics Research Mission Directorate to evaluate the performance and emissions of "drop-in" alternative jet fuels, highlighting experiment design and results from the Alternative Aviation Fuel Experiments (AAFEX-I & -II) and Alternative Fuel-Effects on Contrails and Cruise Emissions flight series (ACCESS-I & II). These projects included almost 100 hours of sampling exhaust emissions from the NASA DC-8 aircraft in both ground and airborne operation and at idle to takeoff thrust settings. Tested fuels included Fischer-Tropsch (FT) synthetic kerosenes manufactured from coal and natural-gas feedstocks; Hydro-treated Esters and Fatty-Acids (HEFA) fuels made from beef-tallow and camelina-plant oil; and 50:50 blends of these alternative fuels with Jet A. Experiments were also conducted with FT and Jet A fuels doped with tetrahydrothiophene to examine the effects of fuel sulfur on volatile aerosol and contrail formation and microphysical properties. Results indicate that although the absence of aromatic compounds in the alternative fuels caused DC-8 fuel-system leaks, the fuels did not compromise engine performance or combustion efficiency. And whereas the alternative fuels produced only slightly different gas-phase emissions, dramatic reductions in non-volatile particulate matter (nvPM) emissions were observed when burning the pure alternative fuels, particularly at low thrust settings where particle number and mass emissions were an order of magnitude lower than measured from standard jet fuel combustion; 50:50 blends of Jet A and alternative fuels typically reduced nvPM emissions by ~50% across all thrust settings. Alternative fuels with the highest hydrogen content produced the greatest nvPM reductions. For Jet A and fuel blends, nvPM emissions were positively correlated with fuel aromatic and naphthalene content. Fuel sulfur content regulated nucleation mode aerosol number and mass concentrations within aging

  19. Synthesis of Reliable Telecommunication Networks

    Directory of Open Access Journals (Sweden)

    Dusan Trstensky

    2005-01-01

    Full Text Available In many application, the network designer may to know to senthesise a reliable telecommunication network. Assume that a network, denoted Gm,e has the number of nodes n and the number of edges e, and the operational probability of each edge is known. The system reliability of the network is defined to be the reliability that every pair of nodes can communicate with each other. A network synthesis problem considered in this paper is to find a network G*n,e, that maximises system reliability over the class of all networks for the classes of networks Gn,n-1, Gn,m and Gn,n+1 respectively. In addition an upper bound of maximum reliability for the networks with n-node and e-edge (e>n+2 is derived in terms of node. Computational experiments for the reliability upper are also presented. the results show, that the proposed reliability upper bound is effective.

  20. Reliability Centered Maintenance - Methodologies

    Science.gov (United States)

    Kammerer, Catherine C.

    2009-01-01

    Journal article about Reliability Centered Maintenance (RCM) methodologies used by United Space Alliance, LLC (USA) in support of the Space Shuttle Program at Kennedy Space Center. The USA Reliability Centered Maintenance program differs from traditional RCM programs because various methodologies are utilized to take advantage of their respective strengths for each application. Based on operational experience, USA has customized the traditional RCM methodology into a streamlined lean logic path and has implemented the use of statistical tools to drive the process. USA RCM has integrated many of the L6S tools into both RCM methodologies. The tools utilized in the Measure, Analyze, and Improve phases of a Lean Six Sigma project lend themselves to application in the RCM process. All USA RCM methodologies meet the requirements defined in SAE JA 1011, Evaluation Criteria for Reliability-Centered Maintenance (RCM) Processes. The proposed article explores these methodologies.

  1. Experimental determination and chemical modelling of radiolytic processes at the spent fuel/water interface. Experiments carried out in carbonate solutions in absence and presence of chloride

    Energy Technology Data Exchange (ETDEWEB)

    Bruno, Jordi; Cera, Esther; Grive, Mireia; Duro, Lara [Enviros Spain SL (Spain); Eriksen, Trygve [Royal Inst. of Tech., Stockholm (Sweden). Dept. of Nuclear Chemistry

    2003-01-01

    We report on the recent experimental and modelling results of a research programme that started in 1995. The aim has been to understand the kinetic and thermodynamic processes that control the radiolytic generation of oxidants and reductants at the spent fuel water interface and their consequences for spent fuel matrix stability and radionuclide release. This has been done by carrying out well-controlled dissolution experiments of PWR Ringhals spent fuel fragments in an initially anoxic closed system and by using different solution compositions. Experimental series started with several tests carried out with deionised water as solvent, in a second phase experiments were conducted with 10 mM bicarbonate solutions. New experimental series were set up during the last two years by using the same bicarbonate content in solutions with varying NaCl concentrations in order to ascertain the role of this ligand on the radiolytic products and its consequence for radionuclide release. The selected NaCl concentrations are in the range of 0.1 to 10 mM. Experimental data shows that uranium dissolution at early contact times is controlled by the oxidation of the UO{sub 2} matrix. This process controls the co-dissolution of most of the analysed radionuclides, including Sr, Mo, Tc, Np and surprisingly enough, Cs. In the overall the release rates for U and the matrix associated radionuclides are in the range of 10{sup -6} moles/day with a clear decreasing trend with exposure time and after 2 years the initial release rates have decreased down to 3x10{sup -8} moles/day. The solubility of the released actinides appears to be limited by the formation of An(IV) hydroxide phases, although Np concentrations in solution did not reach solubility levels during the time intervals of the present tests. No secondary solid phase appears to control the solubility of the rest of the elements.

  2. 生物质颗粒燃料燃烧模拟实验%The Combustion Simulation Experiments on Biomass Pellet Fuel

    Institute of Scientific and Technical Information of China (English)

    矫振伟; 苏俊林; 罗小金

    2011-01-01

    With the combustion test boiler using biomass pellet fuel, the experimental researches of the four working condition were made at different primary and secondary air rate, different positions and different fuel layer thickness. Experiment results show that the heat efficiency of the biomass boiler can reach 77. 69% ,and that environmental protection indexes of exhaust gas, such as NOx ,SO2 and so on,are much lower than those of the coal boiler. The eombustion simulation experiment results provided credible information for the design and operation of the biomass boiler.%在生物质颗粒燃料燃烧试验用锅炉平台上,进行了多种配风、一、二次风配比、不同的二次送风位置及改变燃料层厚度四个工况下的实验研究.实验结果表明:生物质颗粒燃料锅炉热效率高达77.69%,而锅炉排烟中NOx、SO2等环保指标远远低于燃煤锅炉.燃烧模拟实验为生物质颗粒锅炉设计和运行提供规律性参考数据.

  3. A Review and Analysis of European Industrial Experience in Handling LWR Spent Fuel and Vitrified High-Level Waste

    Energy Technology Data Exchange (ETDEWEB)

    Blomeke, J.O.

    2001-07-10

    The industrial facilities that have been built or are under construction in France, the United Kingdom, Sweden, and West Germany to handle light-water reactor (LWR) spent fuel and canisters of vitrified high-level waste before ultimate disposal are described and illustrated with drawings and photographs. Published information on the operating performance of these facilities is also given. This information was assembled for consideration in planning and design of similar equipment and facilities needed for the Federal Waste Management System in the United States.

  4. STEM-EDS analysis of fission products in neutron-irradiated TRISO fuel particles from AGR-1 experiment

    Energy Technology Data Exchange (ETDEWEB)

    Leng, B. [University of Wisconsin-Madison, Madison, WI 53706 (United States); Thorium Molten Salts Reactor Center, Shanghai Institute of Applied Physics, Shanghai, 201800 (China); Rooyen, I.J. van, E-mail: Isabella.vanrooyen@inl.gov [Fuel Design and Development Department, Idaho National Laboratory, Idaho Falls, ID 83415-6188 (United States); Wu, Y.Q. [Department of Materials Science and Engineering, Boise State University, Boise, ID 83725-2090 (United States); Center for Advanced Energy Studies, Idaho Falls, ID 83401 (United States); Szlufarska, I.; Sridharan, K. [University of Wisconsin-Madison, Madison, WI 53706 (United States)

    2016-07-15

    Historic and recent post-irradiation-examination from the German AVR and Advanced Gas Reactor Fuel Development and Qualification Project have shown that 110 m Ag is released from intact tristructural isotropic (TRISO) fuel. Although TRISO fuel particle research has been performed over the last few decades, little is known about how metallic fission products are transported through the SiC layer, and it was not until March 2013 that Ag was first identified in the SiC layer of a neutron-irradiated TRISO fuel particle. The existence of Pd- and Ag-rich grain boundary precipitates, triple junction precipitates, and Pd nano-sized intragranular precipitates in neutron-irradiated TRISO particle coatings was investigated using Scanning Transmission Electron Microscopy and Energy Dispersive Spectroscopy analysis to obtain more information on the chemical composition of the fission product precipitates. A U-rich fission product honeycomb shape precipitate network was found near a micron-sized precipitate in a SiC grain about ∼5 μm from the SiC-inner pyrolytic carbon interlayer, indicating a possible intragranular transport path for uranium. A single Ag-Pd nano-sized precipitate was found inside a SiC grain, and this is the first research showing such finding in irradiated SiC. This finding may possibly suggest a possible Pd-assisted intragranular transport mechanism for Ag and may be related to void or dislocation networks inside SiC grains. Preliminary semi-quantitative analysis indicated the micron-sized precipitates to be Pd{sub 2}Si{sub 2}U with carbon existing inside these precipitates. However, the results of such analysis for nano-sized precipitates may be influenced by the SiC matrix. The results reported in this paper confirm the co-existence of Cd with Ag in triple points reported previously. - Highlights: • First research data in neutron irradiated TRISO coated particles showing a Ag-Pd nano-sized precipitate inside a SiC grain. • Intragranular Ag Pd

  5. Reliability engineering theory and practice

    CERN Document Server

    Birolini, Alessandro

    2010-01-01

    Presenting a solid overview of reliability engineering, this volume enables readers to build and evaluate the reliability of various components, equipment and systems. Current applications are presented, and the text itself is based on the author's 30 years of experience in the field.

  6. Photovoltaic module reliability workshop

    Energy Technology Data Exchange (ETDEWEB)

    Mrig, L. (ed.)

    1990-01-01

    The paper and presentations compiled in this volume form the Proceedings of the fourth in a series of Workshops sponsored by Solar Energy Research Institute (SERI/DOE) under the general theme of photovoltaic module reliability during the period 1986--1990. The reliability Photo Voltaic (PV) modules/systems is exceedingly important along with the initial cost and efficiency of modules if the PV technology has to make a major impact in the power generation market, and for it to compete with the conventional electricity producing technologies. The reliability of photovoltaic modules has progressed significantly in the last few years as evidenced by warranties available on commercial modules of as long as 12 years. However, there is still need for substantial research and testing required to improve module field reliability to levels of 30 years or more. Several small groups of researchers are involved in this research, development, and monitoring activity around the world. In the US, PV manufacturers, DOE laboratories, electric utilities and others are engaged in the photovoltaic reliability research and testing. This group of researchers and others interested in this field were brought together under SERI/DOE sponsorship to exchange the technical knowledge and field experience as related to current information in this important field. The papers presented here reflect this effort.

  7. Grid reliability

    CERN Document Server

    Saiz, P; Rocha, R; Andreeva, J

    2007-01-01

    We are offering a system to track the efficiency of different components of the GRID. We can study the performance of both the WMS and the data transfers At the moment, we have set different parts of the system for ALICE, ATLAS, CMS and LHCb. None of the components that we have developed are VO specific, therefore it would be very easy to deploy them for any other VO. Our main goal is basically to improve the reliability of the GRID. The main idea is to discover as soon as possible the different problems that have happened, and inform the responsible. Since we study the jobs and transfers issued by real users, we see the same problems that users see. As a matter of fact, we see even more problems than the end user does, since we are also interested in following up the errors that GRID components can overcome by themselves (like for instance, in case of a job failure, resubmitting the job to a different site). This kind of information is very useful to site and VO administrators. They can find out the efficien...

  8. Nuclear Energy Research Initiative Project No. 02 103 Innovative Low Cost Approaches to Automating QA/QC of Fuel Particle Production Using On Line Nondestructive Methods for Higher Reliability Final Project Report

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, Salahuddin; Batishko, Charles R.; Flake, Matthew; Good, Morris S.; Mathews, Royce; Morra, Marino; Panetta, Paul D.; Pardini, Allan F.; Sandness, Gerald A.; Tucker, Brian J.; Weier, Dennis R.; Hockey, Ronald L.; Gray, Joseph N.; Saurwein, John J.; Bond, Leonard J.; Lowden, Richard A.; Miller, James H.

    2006-02-28

    This Nuclear Energy Research Initiative (NERI) project was tasked with exploring, adapting, developing and demonstrating innovative nondestructive test methods to automate nuclear coated particle fuel inspection so as to provide the United States (US) with necessary improved and economical Quality Assurance and Control (QA/QC) that is needed for the fuels for several reactor concepts being proposed for both near term deployment [DOE NE & NERAC, 2001] and Generation IV nuclear systems. Replacing present day QA/QC methods, done manually and in many cases destructively, with higher speed automated nondestructive methods will make fuel production for advanced reactors economically feasible. For successful deployment of next generation reactors that employ particle fuels, or fuels in the form of pebbles based on particles, extremely large numbers of fuel particles will require inspection at throughput rates that do not significantly impact the proposed manufacturing processes. The focus of the project is nondestructive examination (NDE) technologies that can be automated for production speeds and make either: (I) On Process Measurements or (II) In Line Measurements. The inspection technologies selected will enable particle “quality” qualification as a particle or group of particles passes a sensor. A multiple attribute dependent signature will be measured and used for qualification or process control decisions. A primary task for achieving this objective is to establish standard signatures for both good/acceptable particles and the most problematic types of defects using several nondestructive methods.

  9. Fuel related risks; Braenslerisker

    Energy Technology Data Exchange (ETDEWEB)

    Englund, Jessica; Sernhed, Kerstin; Nystroem, Olle; Graveus, Frank (Grontmij AB, (Sweden))

    2012-02-15

    The project, within which this work report was prepared, aimed to complement the Vaermeforsk publication 'Handbook of fuels' on fuel related risks and measures to reduce the risks. The fuels examined in this project where the fuels included in the first version of the handbook from 2005 plus four additional fuels that will be included in the second and next edition of the handbook. Following fuels were included: woodfuels (sawdust, wood chips, powder, briquettes), slash, recycled wood, salix, bark, hardwood, stumps, straw, reed canary grass, hemp, cereal, cereal waste, olive waste, cocoa beans, citrus waste, shea, sludge, forest industrial sludge, manure, Paper Wood Plastic, tyre, leather waste, cardboard rejects, meat and bone meal, liquid animal and vegetable wastes, tall oil pitch, peat, residues from food industry, biomal (including slaughterhouse waste) and lignin. The report includes two main chapters; a general risk chapter and a chapter of fuel specific risks. The first one deals with the general concept of risk, it highlights laws and rules relevant for risk management and it discuss general risks that are related to the different steps of fuel handling, i.e. unloading, storing, processing the fuel, transportation within the facility, combustion and handling of ashes. The information that was used to produce this chapter was gathered through a literature review, site visits, and the project group's experience from risk management. The other main chapter deals with fuel-specific risks and the measures to reduce the risks for the steps of unloading, storing, processing the fuel, internal transportation, combustion and handling of the ashes. Risks and measures were considered for all the biofuels included in the second version in the handbook of fuels. Information about the risks and risk management was gathered through interviews with people working with different kinds of fuels in electricity and heat plants in Sweden. The information from

  10. PWR fuel performance and burnup extension in Japan

    Energy Technology Data Exchange (ETDEWEB)

    Yokote, M. [Kansai Electric Power Co., Inc., Osaka (Japan); Kondo, Y.; Abeta, S.

    1996-10-01

    Japanese utilities and fuel manufacturers have expanded much of their resources and efforts to maintain a reliable supply of PWR fuel for Japan. In the early 1970s, since the level of knowledge and experience of using fuel was less than now, some problems were encountered. However, their causes were investigated and countermeasures implemented, the design improved and quality control enhanced. The results can already be seen by significantly improved performance of the PWR plants now in operation, frequency of problems was quickly reduced. Since fuel reliability has been improved, the emphasis has shifted to improving economics by increasing burnup and using uranium resources effectively. The maximum discharged burnup was previously limited to 39 GWd/t and STEP1 burnup extension to 48 GWd/t has been gradually developed, while STEP2 burnup extension to 55 GWd/t is started to be demonstrated from 1996. Because resources in Japan are scarce, a policy was selected of conserving and making effective use of these resources by recycling the uranium and plutonium recovered from reactors. Consequently, significant work is being done on the development of MOX fuel and utilization of recovered uranium. (author)

  11. Proof of concept experiments of the multi-isotope process monitor: An online, nondestructive, near real-time monitor for spent nuclear fuel reprocessing facilities

    Energy Technology Data Exchange (ETDEWEB)

    Orton, Christopher R., E-mail: christopher.orton@pnnl.gov [Pacific Northwest National Laboratory, 902 Battelle Boulevard, P.O. Box 999, Richland, WA 99354 (United States); Fraga, Carlos G., E-mail: carlos.fraga@pnnl.gov [Pacific Northwest National Laboratory, 902 Battelle Boulevard, P.O. Box 999, Richland, WA 99354 (United States); Christensen, Richard N., E-mail: christensen.3@osu.edu [The Ohio State University, 201W. 19th Avenue, Columbus, Ohio 43210 (United States); Schwantes, Jon M., E-mail: jon.schwantes@pnnl.gov [Pacific Northwest National Laboratory, 902 Battelle Boulevard, P.O. Box 999, Richland, WA 99354 (United States)

    2012-04-21

    Operators, national regulatory agencies and the IAEA will require the development of advanced technologies to efficiently control and safeguard nuclear material at increasingly large-scale nuclear recycling facilities. Ideally, the envisioned technologies would be capable of non-destructive, near real-time (NRT), autonomous process monitoring. This paper describes results from proof-of-principle experiments designed to test the multi-isotope process (MIP) monitor, a novel approach to monitoring and safeguarding reprocessing facilities. The MIP Monitor combines the detection of intrinsic gamma ray signatures emitted from process solutions with multivariate analysis to detect off-normal conditions in process streams nondestructively and in NRT. Commercial spent nuclear fuel of various irradiation histories was dissolved and separated using a PUREX-based batch solvent extraction. Extractions were performed at various nitric acid concentrations to mimic both normal and off-normal industrial plant operating conditions. Principal component analysis (PCA) was applied to the simulated gamma spectra to investigate pattern variations as a function of acid concentration, burnup and cooling time. Partial least squares (PLS) regression was applied to attempt to quantify both the acid concentration and burnup of the dissolved spent fuel during the initial separation stage of recycle. The MIP Monitor demonstrated sensitivity to induced variations of acid concentration, including the distinction of {+-}1.3 M variation from normal process conditions by way of PCA. Acid concentration was predicted using measurements from the organic extract and PLS resulting in predictions with <0.7 M relative error. Quantification of burnup levels from dissolved fuel spectra using PLS was demonstrated to be within 2.5% of previously measured values.

  12. Proof of Concept Experiments of the Multi-Isotope Process Monitor: An Online, Nondestructive, Near Real-Time Monitor for Spent Nuclear Fuel Reprocessing Facilities

    Energy Technology Data Exchange (ETDEWEB)

    Orton, Christopher R.; Fraga, Carlos G.; Christensen, Richard; Schwantes, Jon M.

    2012-04-21

    Operators, national regulatory agencies and the IAEA will require the development of advanced technologies to efficiently control and safeguard nuclear material at increasingly large-scale nuclear recycling facilities. Ideally, the envisioned technologies would be capable of non-destructive, near-real-time (NRT), autonomous process monitoring. This paper describes results from proof-of-principle experiments designed to test the Multi-Isotope Process (MIP) Monitor, a novel approach to safeguarding reprocessing facilities. The MIP Monitor combines the detection of intrinsic gamma ray signatures emitted from process solutions with multivariate analysis to detect off-normal conditions in process streams nondestructively and in NRT. Commercial spent nuclear fuel of various irradiation histories was dissolved and separated using a PUREX-based batch solvent extraction. Extractions were performed at various nitric acid concentrations to mimic both normal and off-normal industrial plant operating conditions. Principal Component Analysis (PCA) was applied to the simulated gamma spectra to investigate pattern variations as a function of acid concentration, burnup and cooling time. Partial Least Squares (PLS) regression was applied to attempt to quantify both the acid concentration and burnup of the dissolved spent fuel during the initial separation stage of recycle. The MIP Monitor demonstrated sensitivity to induced variations of acid concentration, including the distinction of {+-} 1.3 M variation from normal process conditions by way of PCA. Acid concentration was predicted using measurements from the organic extract and PLS resulting in predictions with <0.7 M relative error. Quantification of burnup levels from dissolved fuel spectra using PLS was demonstrated to be within 2.5% of previously measured values.

  13. 固液火箭发动机试验瞬时燃速分析方法%Instantaneous Fuel Regression Rate Analysis of Hybrid Rocket Motor Experiment

    Institute of Scientific and Technical Information of China (English)

    李新田; 曾鹏; 田耀; 蔡国飙

    2012-01-01

    介绍了一种用于固液火箭发动机试验的瞬时燃速分析方法,运用该方法对H2O2/HTPB固液火箭发动机单室双推力长时间热试车试验进行燃速分析,拟合得到该工况下的燃速公式为r=1.847×10-2G0o.7304。根据燃速公式等计算结果对一次发动机试验进行了预估,计算得到的预估内弹道性能曲线与试验结果吻合较好,验证了该瞬时燃速分析方法的可行性,为发动机工作时间较长、氧化剂流率变化较大时的燃速分析提供了一种途径。%This paper proposes an instantaneous fuel regression rate analysis method for hybrid rocket motor experiment when the oxidizer mass flux changes large during a long working time. The method is applied on a single-chamber dual-thrust hybrid rocket long-time test with the hydrogen peroxide(H2O2) and hydroxyl-terminated polybutadiene(HTPB) propellant combination, and the fuel regression rate formula,r = 1. 847 × 10 2 Go ^0.7304 , is fitted based on the analysis results. According to the fitted fuel regression rate formula and calculation results, the prediction performances of a test are produced. The results show that the prediction interior ballistics performances fit well with the test curves, which validates the feasibility of the analy- sis method.

  14. Proof of concept experiments of the multi-isotope process monitor: An online, nondestructive, near real-time monitor for spent nuclear fuel reprocessing facilities

    Science.gov (United States)

    Orton, Christopher R.; Fraga, Carlos G.; Christensen, Richard N.; Schwantes, Jon M.

    2012-04-01

    Operators, national regulatory agencies and the IAEA will require the development of advanced technologies to efficiently control and safeguard nuclear material at increasingly large-scale nuclear recycling facilities. Ideally, the envisioned technologies would be capable of non-destructive, near real-time (NRT), autonomous process monitoring. This paper describes results from proof-of-principle experiments designed to test the multi-isotope process (MIP) monitor, a novel approach to monitoring and safeguarding reprocessing facilities. The MIP Monitor combines the detection of intrinsic gamma ray signatures emitted from process solutions with multivariate analysis to detect off-normal conditions in process streams nondestructively and in NRT. Commercial spent nuclear fuel of various irradiation histories was dissolved and separated using a PUREX-based batch solvent extraction. Extractions were performed at various nitric acid concentrations to mimic both normal and off-normal industrial plant operating conditions. Principal component analysis (PCA) was applied to the simulated gamma spectra to investigate pattern variations as a function of acid concentration, burnup and cooling time. Partial least squares (PLS) regression was applied to attempt to quantify both the acid concentration and burnup of the dissolved spent fuel during the initial separation stage of recycle. The MIP Monitor demonstrated sensitivity to induced variations of acid concentration, including the distinction of ±1.3 M variation from normal process conditions by way of PCA. Acid concentration was predicted using measurements from the organic extract and PLS resulting in predictions with <0.7 M relative error. Quantification of burnup levels from dissolved fuel spectra using PLS was demonstrated to be within 2.5% of previously measured values.

  15. Solid fuels as engine fuels. Kiinteiden polttoaineiden kaeyttoemahdollisuudet moottoripolttoaineena

    Energy Technology Data Exchange (ETDEWEB)

    Vakkilainen, A.; Nylund, N.-O.

    1986-07-01

    The use of solid fuels as engine fuels is discussed in this literature study. The present liquid fuel engines require extensive and expensive changes to overcome difficulties due to solid fuels. The solid particles result in increasing wear in the engine, in the fuel feed system and everywhere, where the particles come into touch with moving surfaces. The rate of wear has been as high as 100-fold compared to that caused by liquid fuels. Large medium-fast or slow diesel engines seem to meet best the requirements set by solid fuels. The experiment carried out by the Swiss Sulzer Engine Works are the most promising engine experiments carried out so far. In Sulzer's experiments, coal-water slurries containing 50-70 wt-% coal have been used as the fuel. Burning has been rather complete, but wear and the high price of the coal-water slurry seem to be unsolvable problems. The development work on enines is still at an early stage and a solid fuel engine will not be manufactured in series in the near future. The pulverous fuel of the future will be a mixture of some liquid and of some solid fuel powder, and hence the handling-technical problems will be considerably smaller than using powder only. Powder manufacture with the present techniques is energy-wasting. Most engine experiments have been carried out on on coal slurries with < 30 ..mu..m particle size. It is not economic to produce such powders at present.

  16. Reliability engineering theory and practice

    CERN Document Server

    Birolini, Alessandro

    2014-01-01

    This book shows how to build in, evaluate, and demonstrate reliability and availability of components, equipment, systems. It presents the state-of-theart of reliability engineering, both in theory and practice, and is based on the author's more than 30 years experience in this field, half in industry and half as Professor of Reliability Engineering at the ETH, Zurich. The structure of the book allows rapid access to practical results. This final edition extend and replace all previous editions. New are, in particular, a strategy to mitigate incomplete coverage, a comprehensive introduction to human reliability with design guidelines and new models, and a refinement of reliability allocation, design guidelines for maintainability, and concepts related to regenerative stochastic processes. The set of problems for homework has been extended. Methods & tools are given in a way that they can be tailored to cover different reliability requirement levels and be used for safety analysis. Because of the Appendice...

  17. Photovoltaic performance and reliability workshop

    Energy Technology Data Exchange (ETDEWEB)

    Mrig, L. [ed.

    1993-12-01

    This workshop was the sixth in a series of workshops sponsored by NREL/DOE under the general subject of photovoltaic testing and reliability during the period 1986--1993. PV performance and PV reliability are at least as important as PV cost, if not more. In the US, PV manufacturers, DOE laboratories, electric utilities, and others are engaged in the photovoltaic reliability research and testing. This group of researchers and others interested in the field were brought together to exchange the technical knowledge and field experience as related to current information in this evolving field of PV reliability. The papers presented here reflect this effort since the last workshop held in September, 1992. The topics covered include: cell and module characterization, module and system testing, durability and reliability, system field experience, and standards and codes.

  18. Ex situ bioremediation of a soil contaminated by mazut (heavy residual fuel oil)--a field experiment.

    Science.gov (United States)

    Beškoski, Vladimir P; Gojgić-Cvijović, Gordana; Milić, Jelena; Ilić, Mila; Miletić, Srdjan; Solević, Tatjana; Vrvić, Miroslav M

    2011-03-01

    Mazut (heavy residual fuel oil)-polluted soil was exposed to bioremediation in an ex situ field-scale (600 m(3)) study. Re-inoculation was performed periodically with biomasses of microbial consortia isolated from the mazut-contaminated soil. Biostimulation was conducted by adding nutritional elements (N, P and K). The biopile (depth 0.4m) was comprised of mechanically mixed polluted soil with softwood sawdust and crude river sand. Aeration was improved by systematic mixing. The biopile was protected from direct external influences by a polyethylene cover. Part (10 m(3)) of the material prepared for bioremediation was set aside uninoculated, and maintained as an untreated control pile (CP). Biostimulation and re-inoculation with zymogenous microorganisms increased the number of hydrocarbon degraders after 50 d by more than 20 times in the treated soil. During the 5 months, the total petroleum hydrocarbon (TPH) content of the contaminated soil was reduced to 6% of the initial value, from 5.2 to 0.3 g kg(-1) dry matter, while TPH reduced to only 90% of the initial value in the CP. After 150 d there were 96%, 97% and 83% reductions for the aliphatic, aromatic, and nitrogen-sulphur-oxygen and asphaltene fractions, respectively. The isoprenoids, pristane and phytane, were more than 55% biodegraded, which indicated that they are not suitable biomarkers for following bioremediation. According to the available data, this is the first field-scale study of the bioremediation of mazut and mazut sediment-polluted soil, and the efficiency achieved was far above that described in the literature to date for heavy fuel oil.

  19. Study on reliability technology of contactor relay

    Institute of Scientific and Technical Information of China (English)

    LIU Guo-jin; ZHAO Jing-ying; WANG Hai-tao; YANG Chen-guang; SUN Shun-li

    2007-01-01

    In this paper, the reliability of contactor relay is studied. There are three main parts about reliability test and analysis. First, in order to analyze reliability level of contact relay, the failure ratio ranks are established as index base on the product level. Second, the reliability test method is put forward. The sample plan of reliability compliance test is gained from reliability sample theory. The failure criterion is ensured according to the failure modes of contactor relay. Third, after reliability test experiment, the analysis of failure physics is made and the failure reason is found.

  20. Status of advanced fuel candidates for Sodium Fast Reactor within the Generation IV International Forum

    Science.gov (United States)

    Delage, F.; Carmack, J.; Lee, C. B.; Mizuno, T.; Pelletier, M.; Somers, J.

    2013-10-01

    The main challenge for fuels for future Sodium Fast Reactor systems is the development and qualification of a nuclear fuel sub-assembly which meets the Generation IV International Forum goals. The Advanced Fuel project investigates high burn-up minor actinide bearing fuels as well as claddings and wrappers to withstand high neutron doses and temperatures. The R&D outcome of national and collaborative programs has been collected and shared between the AF project members in order to review the capability of sub-assembly material and fuel candidates, to identify the issues and select the viable options. Based on historical experience and knowledge, both oxide and metal fuels emerge as primary options to meet the performance and the reliability goals of Generation IV SFR systems. There is a significant positive experience on carbide fuels but major issues remain to be overcome: strong in-pile swelling, atmosphere required for fabrication as well as Pu and Am losses. The irradiation performance database for nitride fuels is limited with longer term R&D activities still required. The promising core material candidates are Ferritic/Martensitic (F/M) and Oxide Dispersed Strengthened (ODS) steels.

  1. Simulation of the nuclear fuel assembly drop test with LS-Dyna

    Energy Technology Data Exchange (ETDEWEB)

    Petkevich, P., E-mail: petya2306@gmail.com; Abramov, V.; Yuremenko, V.; Piminov, V.; Makarov, V.; Afanasiev, A.

    2014-04-01

    Transportation of the nuclear fuel containing objects is especially sensitive to accidental drops, as any event, affecting the fuel spacial arrangement, alters also neutron multiplication factor and can result in uncontrolled chain reaction. The latter is particularly important for nuclear fuel being immersed in water. Apart from that, fall can result in a mechanical damage of the fuel rods, which can cause environmental pollution by radionuclides. Final and intermediate fuel configurations during the accident depend on the impact velocity and the angle between falling object and the surface. Experiments cannot cover all the possible variants of drops, as it would result in their unacceptable prices. Therefore elaboration of the approaches to numerically simulate such kind of accidents is an essential step in the nuclear fuel transportation safety analysis and is the principal goal of the present research. Series of drop tests with fuel assemblies (FA) models of different complexity have been performed and numerically simulated with LS-Dyna software in order to proof the reliability of such kind of analysis. The paper contains description of the drop test experimental facility, some experimental results and their numerical simulation. It has been found that the finite element model of the FA and the material properties used for the simulation provide reliable predictions of the FA materials deformation and failure in case of accidental drops onto a rigid surface.

  2. Results of Severe Fuel Damage Experiment QUENCH-14 with Advanced Rod Cladding M5®. (KIT Scientific Reports ; 7549)

    OpenAIRE

    STUCKERT J.; Große, M.; Stegmaier, U.; Steinbrück, M.

    2010-01-01

    The QUENCH experiments are to investigate the hydrogen release resulting from the water injection into an uncovered core of a Light Water Reactor as well as the high-temperature behavior of core materials. The QUENCH-14 experiment investigated the effect of M5® cladding material on bundle oxidation and core reflood, in comparison with the tests QUENCH-06 that used standard Zircaloy-4 and QUENCH-12 that used VVER E110-claddings.

  3. Equipment for the management of spent fuels and radioactive waste

    Energy Technology Data Exchange (ETDEWEB)

    Bower, C. C. F.; Carter, C. C.; Doubt, H. A. [GEC Alsthom Engineering System Ltd., Leicester (United Kingdom)

    1996-04-15

    UK experience over the last thirty years with the design and implementation of equipment for the management of spent fuels and radioactive wastes has ranged from remote handling, through encapsulation and containerisation, to the medium-term storage of heat-producing fuels and wastes in the dry state. The design principles involved in handling, transporting and storing hazardous materials safely and reliably, while ensuring biological shielding, containment and cooling of radioactive materials, are common to the various kinds of equipment presented in this paper, even though the individual requirements may be very different. The UK nuclear programme over the last thirty years has encouraged the development of extensive expertise in the engineering of equipment for the management of spent fuel and radioactive waste. This expertise can be applied with benefit to the Korean nuclear programme.

  4. Luncheon address: Early days of CANDU fuel

    Energy Technology Data Exchange (ETDEWEB)

    Page, R.D. [Atomic Energy of Canada Limited (Canada)

    1997-07-01

    This will briefly describe how the original dimensions of the fuel bundle were defined and how that early designs of fuel evolved. I will also touch on some of the historical events of the materials and experiments which effected the fuel programme. Also how I became with Canada's Nuclear Fuel programme. (author)

  5. Instant release of fission products in leaching experiments with high burn-up nuclear fuels in the framework of the Euratom project FIRST- Nuclides

    Science.gov (United States)

    Lemmens, K.; González-Robles, E.; Kienzler, B.; Curti, E.; Serrano-Purroy, D.; Sureda, R.; Martínez-Torrents, A.; Roth, O.; Slonszki, E.; Mennecart, T.; Günther-Leopold, I.; Hózer, Z.

    2017-02-01

    The instant release of fission products from high burn-up UO2 fuels and one MOX fuel was investigated by means of leach tests. The samples covered PWR and BWR fuels at average rod burn-up in the range of 45-63 GWd/tHM and included clad fuel segments, fuel segments with opened cladding, fuel fragments and fuel powder. The tests were performed with sodium chloride - bicarbonate solutions under oxidizing conditions and, for one test, in reducing Ar/H2 atmosphere. The iodine and cesium release could be partially explained by the differences in sample preparation, leading to different sizes and properties of the exposed surface areas. Iodine and cesium releases tend to correlate with FGR and linear power rating, but the scatter of the data is significant. Although the gap between the fuel and the cladding was closed in some high burn-up samples, fissures still provide possible preferential transport pathways.

  6. Designs and development of fuel spay measurement system for experiments%实验用燃油喷雾检测系统的设计与开发

    Institute of Scientific and Technical Information of China (English)

    马宗正; 徐平; 杨安杰; 刘豫喜

    2016-01-01

    Aiming at the high price for the fuel spray measurement system in the laboratory which is harmful to the practical teaching,one fuel spray measurement system for the experiment is designed and developed.This system is based on light scattering principle and it consists of 8 bit single-chip processor,common opt coupler chip and field-effect tube driven chip.Then the control system is designed based on the hardware,and it can realize the inj ection,CCD camera and strobe light automatic control.Meanwhile,the image processing software is completed based on Matlab platform.It is proved by the experiment that the fuel spray process image can be achieved and the spray also can be processed quantitatively based on the image.So it is helpful to improve the understanding of the theoretical knowledge.%针对目前实验室能用于测量燃油喷雾的检测系统,不利于实践教学的问题,开发了一款实验用燃油喷雾检测系统。该系统基于散射法原理,以8位单片机为处理器、普通光耦芯片和场效应管为驱动芯片,完成了控制系统的开发,实现了对于喷油、CCD相机和频闪光源的控制,同时基于 Matlab 软件完成了图像处理程序的开发。经过测试验证,该系统可以实现喷雾过程的图像采集,同时还可以对喷雾过程进行定量处理。该系统对于提高学生对于理论知识的掌握有着积极作用。

  7. European opportunities for fuel cell commercialisation

    Science.gov (United States)

    Gibbs, C. E.; Steel, M. C. F.

    1992-01-01

    when demand for power exceeds supply. The SWB solar hydrogen project in Germany is testing PAFC and AFC stacks in this application. Several problems remain before fuel cell technology can fulfil its maximum potential market. For PAFC there is a need to reduce plant capital costs and to verify lifetimes and reliability. KTI's 25 kW demonstration at Delft and the Milan 1 MW plant will increase European knowledge and experience of PAFC plant operation. For MCFC there are materials problems to be solved and work needs to be carried out on the best way to scale up plants. Projects underway in the Netherlands, Germany, Italy and elsewhere should bring Europe to the forefront of MCFC technology. SOFC requires further study in the area of design configurations and fabrication techniques. Research on these aspects is underway in Denmark, Switzerland, Germany, the Netherlands and the UK. For PEM technology work on reducing precious metal loadings and selecting the best polymer membrane is required — an area in which Johnson Matthey is involved. For all fuel cell technologies there needs to be a greater awareness among power suppliers, consumers, legislators and environmentalists of the advantages that fuel cells can offer. The increase in activity among European organisations in developing, demonstrating, testing and optimising fuel cell systems will encourage a greater awareness of the technology and bring commercialisation closer to reality.

  8. Power electronics reliability.

    Energy Technology Data Exchange (ETDEWEB)

    Kaplar, Robert James; Brock, Reinhard C.; Marinella, Matthew; King, Michael Patrick; Stanley, James K.; Smith, Mark A.; Atcitty, Stanley

    2010-10-01

    The project's goals are: (1) use experiments and modeling to investigate and characterize stress-related failure modes of post-silicon power electronic (PE) devices such as silicon carbide (SiC) and gallium nitride (GaN) switches; and (2) seek opportunities for condition monitoring (CM) and prognostics and health management (PHM) to further enhance the reliability of power electronics devices and equipment. CM - detect anomalies and diagnose problems that require maintenance. PHM - track damage growth, predict time to failure, and manage subsequent maintenance and operations in such a way to optimize overall system utility against cost. The benefits of CM/PHM are: (1) operate power conversion systems in ways that will preclude predicted failures; (2) reduce unscheduled downtime and thereby reduce costs; and (3) pioneering reliability in SiC and GaN.

  9. Quantification of the reliability of personnel actions from the evaluation of actual German operational experience. Final report; Quantifizierung der Zuverlaessigkeit von Personalhandlungen durch Auswertung der aktuellen deutschen Betriebserfahrung. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Preischl, W.; Fassmann, W.

    2013-07-15

    The results and their uncertainty bounds of PSA studies are considerably impacted by the assessment of human reliability. But the amount of available, generic data is not sufficient to evaluate all human actions considered in a modern PSA study adequately. Further the data are not sufficiently validated and rely as well as the proposed uncertainty bounds on expert judgement. This research project as well as the preceding project /GRS 10/ validated data recommended by the German PSA Guidelines and enlarged the amount of available data. The findings may contribute to an update of the German PSA Guidelines. In a first step of the project information about reportable events in German nuclear power plants with observed human errors (event reports, expert statements, technical documents, interviews and plant walk downs with subject matter experts from the plants) were analysed. The investigation resulted in 67 samples describing personal activities, performance conditions, the number of observed errors and the number of action performance. In a second step a new methodology was developed and applied in a pilot plant. The objective was to identify undoubtedly error free safety relevant actions, their performance conditions, and frequency as well as to prove and demonstrate that probabilistic data can be derived from that operational experience (OE). The application in the pilot plant resulted in 18 ''error free'' samples characterizing human reliability. All available samples were evaluated by use of the method of Bayes. That commonly accepted methodology was applied in order to derive probabilistic data based on samples taken from operational experience. A thorough analysis of the obtained results shows that both data sources (OE reportable events, OE with undoubtedly error free action performance) provide data with comparable quality and validity. At the end of the research project the following products are available. - Methods to select samples

  10. Hydrocarbon characterization experiments in fully turbulent fires.

    Energy Technology Data Exchange (ETDEWEB)

    Ricks, Allen; Blanchat, Thomas K.

    2007-05-01

    As the capabilities of numerical simulations increase, decision makers are increasingly relying upon simulations rather than experiments to assess risks across a wide variety of accident scenarios including fires. There are still, however, many aspects of fires that are either not well understood or are difficult to treat from first principles due to the computational expense. For a simulation to be truly predictive and to provide decision makers with information which can be reliably used for risk assessment the remaining physical processes must be studied and suitable models developed for the effects of the physics. The model for the fuel evaporation rate in a liquid fuel pool fire is significant because in well-ventilated fires the evaporation rate largely controls the total heat release rate from the fire. A set of experiments are outlined in this report which will provide data for the development and validation of models for the fuel regression rates in liquid hydrocarbon fuel fires. The experiments will be performed on fires in the fully turbulent scale range (> 1 m diameter) and with a number of hydrocarbon fuels ranging from lightly sooting to heavily sooting. The importance of spectral absorption in the liquid fuels and the vapor dome above the pool will be investigated and the total heat flux to the pool surface will be measured. The importance of convection within the liquid fuel will be assessed by restricting large scale liquid motion in some tests. These data sets will provide a sound, experimentally proven basis for assessing how much of the liquid fuel needs to be modeled to enable a predictive simulation of a fuel fire given the couplings between evaporation of fuel from the pool and the heat release from the fire which drives the evaporation.

  11. Review of the LBDS Safety and Reliability Analysis in the Light of the Operational Experience during the Period 2010-2012

    CERN Document Server

    Filippini, R

    2013-01-01

    During the years 2010, 2011 and 2012 a large amount of LHC data was recorded, which also included failure events in the LHC Beam Dumping System (LBDS). We used these data for the validation of the safety and reliability analyses of the LBDS which were performed in 2003-2006. The results of the analysis confirm the agreement of the calculated statistics with the predicted estimates. The LBDS generated a number of about 10 false beam dumps per year, which is in agreement with the estimated 8 ± 2. A thorough investigation of the data set also confirms that the LBDS always preserved a sufficient residual margin of safety for all identified failure scenarios, and globally meets SIL3 at least. These results are accompanied by several recommendations, among which instructions for updating the reliability model to the actual operation scenarios, and suggestions for the improvement of safety and availability of the LBDS.

  12. Evaluation Metrics Applied to Accident Tolerant Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Shannon M. Bragg-Sitton; Jon Carmack; Frank Goldner

    2014-10-01

    The safe, reliable, and economic operation of the nation’s nuclear power reactor fleet has always been a top priority for the United States’ nuclear industry. Continual improvement of technology, including advanced materials and nuclear fuels, remains central to the industry’s success. Decades of research combined with continual operation have produced steady advancements in technology and have yielded an extensive base of data, experience, and knowledge on light water reactor (LWR) fuel performance under both normal and accident conditions. One of the current missions of the U.S. Department of Energy’s (DOE) Office of Nuclear Energy (NE) is to develop nuclear fuels and claddings with enhanced accident tolerance for use in the current fleet of commercial LWRs or in reactor concepts with design certifications (GEN-III+). Accident tolerance became a focus within advanced LWR research upon direction from Congress following the 2011 Great East Japan Earthquake, resulting tsunami, and subsequent damage to the Fukushima Daiichi nuclear power plant complex. The overall goal of ATF development is to identify alternative fuel system technologies to further enhance the safety, competitiveness and economics of commercial nuclear power. Enhanced accident tolerant fuels would endure loss of active cooling in the reactor core for a considerably longer period of time than the current fuel system while maintaining or improving performance during normal operations. The U.S. DOE is supporting multiple teams to investigate a number of technologies that may improve fuel system response and behavior in accident conditions, with team leadership provided by DOE national laboratories, universities, and the nuclear industry. Concepts under consideration offer both evolutionary and revolutionary changes to the current nuclear fuel system. Mature concepts will be tested in the Advanced Test Reactor at Idaho National Laboratory beginning in Summer 2014 with additional concepts being

  13. Space Vehicle Reliability Modeling in DIORAMA

    Energy Technology Data Exchange (ETDEWEB)

    Tornga, Shawn Robert [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-07-12

    When modeling system performance of space based detection systems it is important to consider spacecraft reliability. As space vehicles age the components become prone to failure for a variety of reasons such as radiation damage. Additionally, some vehicles may lose the ability to maneuver once they exhaust fuel supplies. Typically failure is divided into two categories: engineering mistakes and technology surprise. This document will report on a method of simulating space vehicle reliability in the DIORAMA framework.

  14. Reliability estimation using kriging metamodel

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Tae Min; Ju, Byeong Hyeon; Lee, Byung Chai [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of); Jung, Do Hyun [Korea Automotive Technology Institute, Chonan (Korea, Republic of)

    2006-08-15

    In this study, the new method for reliability estimation is proposed using kriging metamodel. Kriging metamodel can be determined by appropriate sampling range and sampling numbers because there are no random errors in the Design and Analysis of Computer Experiments(DACE) model. The first kriging metamodel is made based on widely ranged sampling points. The Advanced First Order Reliability Method(AFORM) is applied to the first kriging metamodel to estimate the reliability approximately. Then, the second kriging metamodel is constructed using additional sampling points with updated sampling range. The Monte-Carlo Simulation(MCS) is applied to the second kriging metamodel to evaluate the reliability. The proposed method is applied to numerical examples and the results are almost equal to the reference reliability.

  15. Spent-fuel-storage alternatives

    Energy Technology Data Exchange (ETDEWEB)

    1980-01-01

    The Spent Fuel Storage Alternatives meeting was a technical forum in which 37 experts from 12 states discussed storage alternatives that are available or are under development. The subject matter was divided into the following five areas: techniques for increasing fuel storage density; dry storage of spent fuel; fuel characterization and conditioning; fuel storage operating experience; and storage and transport economics. Nineteen of the 21 papers which were presented at this meeting are included in this Proceedings. These have been abstracted and indexed. (ATT)

  16. Spent-fuel-storage alternatives

    Energy Technology Data Exchange (ETDEWEB)

    1980-01-01

    The Spent Fuel Storage Alternatives meeting was a technical forum in which 37 experts from 12 states discussed storage alternatives that are available or are under development. The subject matter was divided into the following five areas: techniques for increasing fuel storage density; dry storage of spent fuel; fuel characterization and conditioning; fuel storage operating experience; and storage and transport economics. Nineteen of the 21 papers which were presented at this meeting are included in this Proceedings. These have been abstracted and indexed. (ATT)

  17. 回转窑热解城市垃圾制造中热值燃气的试验%EXPERIMENT ON MANUFACTURE MEDIUMHEATING VALUE FUEL GAS BY PYROLYZING MUNICIPAL REFUSE IN A ROTARY KILN

    Institute of Scientific and Technical Information of China (English)

    李爱民; 李晓东; 李水清; 严建华; 岑可法

    1999-01-01

    Manufacturing fuel gases by pyrolyzing municipal refuse is an attractive technology. A laboratory-scale externally heated rotary kiln was designed and developed, and a series of the pyrolysis experiments were done with paper,paper board,waste plastic(including PVC plastic and PE plastic),rubber,vegetable,wood cloth and orange husk were selected as the sample species of the main organic groups of municipal refuse.The yield and the heating value of the fuel gas were measured;The effects of moisture and size of raw materials on pyrolysis were studied by taking wood chips as an example and the effects of the heating methods on pyrolysis gas yield and the variations of gas composition and heating value during pyrolysis were discussed.At last,the efficiency of pyrolysis,the conversion fraction of fuel gas and gas yield were defined and the results of the experiments were analyzed in terms of such definitions.

  18. Delta-Reliability

    OpenAIRE

    Eugster, P.; Guerraoui, R.; Kouznetsov, P.

    2001-01-01

    This paper presents a new, non-binary measure of the reliability of broadcast algorithms, called Delta-Reliability. This measure quantifies the reliability of practical broadcast algorithms that, on the one hand, were devised with some form of reliability in mind, but, on the other hand, are not considered reliable according to the ``traditional'' notion of broadcast reliability [HT94]. Our specification of Delta-Reliability suggests a further step towards bridging the gap between theory and...

  19. Fossil Fuels.

    Science.gov (United States)

    Crank, Ron

    This instructional unit is one of 10 developed by students on various energy-related areas that deals specifically with fossil fuels. Some topics covered are historic facts, development of fuels, history of oil production, current and future trends of the oil industry, refining fossil fuels, and environmental problems. Material in each unit may…

  20. Fossil Fuels.

    Science.gov (United States)

    Crank, Ron

    This instructional unit is one of 10 developed by students on various energy-related areas that deals specifically with fossil fuels. Some topics covered are historic facts, development of fuels, history of oil production, current and future trends of the oil industry, refining fossil fuels, and environmental problems. Material in each unit may…

  1. Fuel Handbook[Wood and other renewable fuels

    Energy Technology Data Exchange (ETDEWEB)

    Stroemberg, Birgitta [TPS Termiska Processer AB, Nykoeping (SE)] (ed.)

    2006-03-15

    This handbook on renewable fuels is intended for power and heat producers in Sweden. This fuel handbook provides, from a plant owner's perspective, a method to evaluate different fuels on the market. The fuel handbook concerns renewable fuels (but does not include household waste) that are available on the Swedish market today or fuels that have potential to be available within the next ten years. The handbook covers 26 different fuels. Analysis data, special properties, operating experiences and literature references are outlined for each fuel. [Special properties, operating experiences and literature references are not included in this English version] The handbook also contains: A proposed methodology for introduction of new fuels. A recommendation of analyses and tests to perform in order to reduce the risk of problems is presented. [The recommendation of analyses and tests is not included in the English version] A summary of relevant laws and taxes for energy production, with references to relevant documentation. [Only laws and taxes regarding EU are included] Theory and background to evaluate a fuel with respect to combustion, ash and corrosion properties and methods that can be used for such evaluations. Summary of standards, databases and handbooks on biomass fuels and other solid fuels, and links to web sites where further information about the fuels can be found. The appendices includes: A methodology for trial firing of fuels. Calculations procedures for, amongst others, heating value, flue gas composition, key number and free fall velocity [Free fall velocity is not included in the English version]. In addition, conversion routines between different units for a number of different applications are provided. Fuel analyses are presented in the appendix. (The report is a translation of parts of the report VARMEFORSK--911 published in 2005)

  2. Reliability computation from reliability block diagrams

    Science.gov (United States)

    Chelson, P. O.; Eckstein, E. Y.

    1975-01-01

    Computer program computes system reliability for very general class of reliability block diagrams. Four factors are considered in calculating probability of system success: active block redundancy, standby block redundancy, partial redundancy, and presence of equivalent blocks in the diagram.

  3. Advanced PWR in-core fuel management with optimized gadolinia fuel designs

    Energy Technology Data Exchange (ETDEWEB)

    Berger, H.D.; Neufert, A. [Siemens AG / Power Generation KWU, Nuclear Fuel Cycle, Erlangen (Germany)

    1999-07-01

    Utilities operating LWRs require fuel assemblies and in-core fuel management service, which ensure safe, flexible and cost-effective production of electricity. With the reliability of the fuel having been always the most important requirement, advanced measures to minimize fuel cycle costs are receiving increasing attention in the light of the pressure on costs within the de-regulated power generation markets. The role of in-core fuel management in supporting the goal to minimize fuel cycle costs consists in the development of more demanding core loading strategies, i.e. in the first place more advanced low leakage loading patterns. A prerequisite for this type of loading pattern is the use of an optimized burnable absorber design. Gadolinia as integrated burnable absorber is a very effective means for limiting the critical boron concentration and power peaking factors. Siemens has accumulated extensive experience with Gd-fuel for almost 20 years with e.g. more than 5500 Gd-FA's delivered for PWRs and irradiated up to 65 MWd/kg{sub HM}. Current development efforts for optimizing Gd-fuel are focused on the reduction of the inherent penalties of today's Gd-Fa designs, i.e. reduced average FA enrichment and heavy metal content as well as residual reactivity binding. The most effective way to overcome these drawbacks is the reduction of the Gd{sub 2}O{sub 3} concentration to values of approximately 2 w/o, for which according to recent measurements of the heat conductivity of modern Gd-fuels the reduction of the fissile content in the Gd-rods is no longer necessary. Various feasibility studies have been performed to evaluate the consequences of low-Gd designs for both Siemens PWRs and Non-Siemens PWRs, for which more restrictive boundary conditions with respect to critical boron concentration and peaking factors have to be fulfilled. These studies as well as the first realization of an extended reactor cycle using a low Gd-Fa reload design confirm that the in

  4. Summary of thermocouple performance during advanced gas reactor fuel irradiation experiments in the advanced test reactor and out-of-pile thermocouple testing in support of such experiments

    Energy Technology Data Exchange (ETDEWEB)

    Palmer, A. J.; Haggard, DC; Herter, J. W.; Swank, W. D.; Knudson, D. L.; Cherry, R. S. [Idaho National Laboratory, P.O. Box 1625, MS 4112, Idaho Falls, ID, (United States); Scervini, M. [University of Cambridge, Department of Material Science and Metallurgy, 27 Charles Babbage Road, CB3 0FS, Cambridge, (United Kingdom)

    2015-07-01

    High temperature gas reactor experiments create unique challenges for thermocouple-based temperature measurements. As a result of the interaction with neutrons, the thermoelements of the thermocouples undergo transmutation, which produces a time-dependent change in composition and, as a consequence, a time-dependent drift of the thermocouple signal. This drift is particularly severe for high temperature platinum-rhodium thermocouples (Types S, R, and B) and tungsten-rhenium thermocouples (Type C). For lower temperature applications, previous experiences with Type K thermocouples in nuclear reactors have shown that they are affected by neutron irradiation only to a limited extent. Similarly, Type N thermocouples are expected to be only slightly affected by neutron fluence. Currently, the use of these nickel-based thermocouples is limited when the temperature exceeds 1000 deg. C due to drift related to phenomena other than nuclear irradiation. High rates of open-circuit failure are also typical. Over the past 10 years, three long-term Advanced Gas Reactor experiments have been conducted with measured temperatures ranging from 700 deg. C - 1200 deg. C. A variety of standard Type N and specialty thermocouple designs have been used in these experiments with mixed results. A brief summary of thermocouple performance in these experiments is provided. Most recently, out-of-pile testing has been conducted on a variety of Type N thermocouple designs at the following (nominal) temperatures and durations: 1150 deg. C and 1200 deg. C for 2,000 hours at each temperature, followed by 200 hours at 1250 deg. C and 200 hours at 1300 deg. C. The standard Type N design utilizes high purity, crushed MgO insulation and an Inconel 600 sheath. Several variations on the standard Type N design were tested, including a Haynes 214 alloy sheath, spinel (MgAl{sub 2}O{sub 4}) insulation instead of MgO, a customized sheath developed at the University of Cambridge, and finally a loose assembly

  5. Summary of Thermocouple Performance During Advanced Gas Reactor Fuel Irradiation Experiments in the Advanced Test Reactor and Out-of-Pile Thermocouple Testing in Support of Such Experiments

    Energy Technology Data Exchange (ETDEWEB)

    A. J. Palmer; DC Haggard; J. W. Herter; M. Scervini; W. D. Swank; D. L. Knudson; R. S. Cherry

    2011-07-01

    High temperature gas reactor experiments create unique challenges for thermocouple based temperature measurements. As a result of the interaction with neutrons, the thermoelements of the thermocouples undergo transmutation, which produces a time dependent change in composition and, as a consequence, a time dependent drift of the thermocouple signal. This drift is particularly severe for high temperature platinum-rhodium thermocouples (Types S, R, and B); and tungsten-rhenium thermocouples (Types C and W). For lower temperature applications, previous experiences with type K thermocouples in nuclear reactors have shown that they are affected by neutron irradiation only to a limited extent. Similarly type N thermocouples are expected to be only slightly affected by neutron fluxes. Currently the use of these Nickel based thermocouples is limited when the temperature exceeds 1000°C due to drift related to phenomena other than nuclear irradiation. High rates of open-circuit failure are also typical. Over the past ten years, three long-term Advanced Gas Reactor (AGR) experiments have been conducted with measured temperatures ranging from 700oC – 1200oC. A variety of standard Type N and specialty thermocouple designs have been used in these experiments with mixed results. A brief summary of thermocouple performance in these experiments is provided. Most recently, out of pile testing has been conducted on a variety of Type N thermocouple designs at the following (nominal) temperatures and durations: 1150oC and 1200oC for 2000 hours at each temperature, followed by 200 hours at 1250oC, and 200 hours at 1300oC. The standard Type N design utilizes high purity crushed MgO insulation and an Inconel 600 sheath. Several variations on the standard Type N design were tested, including Haynes 214 alloy sheath, spinel (MgAl2O4) insulation instead of MgO, a customized sheath developed at the University of Cambridge, and finally a loose assembly thermocouple with hard fired alumina

  6. Fuel storage systems

    Energy Technology Data Exchange (ETDEWEB)

    Donakowski, T.D.; Tison, R.R.

    1979-08-01

    Storage technologies are characterized for solid, liquid, and gaseous fuels. Emphasis is placed on storage methods applicable to Integrated Community Energy Systems based on coal. Items discussed here include standard practice, materials and energy losses, environmental effects, operating requirements, maintenance and reliability, and cost considerations. All storage systems were found to be well-developed and to represent mature technologies; an exception may exist for low-Btu gas storage, which could have materials incompatability.

  7. Software Reliability through Theorem Proving

    Directory of Open Access Journals (Sweden)

    S.G.K. Murthy

    2009-05-01

    Full Text Available Improving software reliability of mission-critical systems is widely recognised as one of the major challenges. Early detection of errors in software requirements, designs and implementation, need rigorous verification and validation techniques. Several techniques comprising static and dynamic testing approaches are used to improve reliability of mission critical software; however it is hard to balance development time and budget with software reliability. Particularly using dynamic testing techniques, it is hard to ensure software reliability, as exhaustive testing is not possible. On the other hand, formal verification techniques utilise mathematical logic to prove correctness of the software based on given specifications, which in turn improves the reliability of the software. Theorem proving is a powerful formal verification technique that enhances the software reliability for missioncritical aerospace applications. This paper discusses the issues related to software reliability and theorem proving used to enhance software reliability through formal verification technique, based on the experiences with STeP tool, using the conventional and internationally accepted methodologies, models, theorem proving techniques available in the tool without proposing a new model.Defence Science Journal, 2009, 59(3, pp.314-317, DOI:http://dx.doi.org/10.14429/dsj.59.1527

  8. AFC-1 Transmutation Fuels Post-Irradiation Hot Cell Examination 4-8 at.% - Final Report (Irradiation Experiments AFC-1B, -1F and -1Æ)

    Energy Technology Data Exchange (ETDEWEB)

    Bruce Hilton; Douglas Porter; Steven Hayes

    2006-09-01

    The AFC-1B, AFC-1F and AFC-1Æ irradiation tests are part of a series of test irradiations designed to evaluate the feasibility of the use of actinide bearing fuel forms in advanced fuel cycles for the transmutation of transuranic elements from nuclear waste. The tests were irradiated in the Idaho National Laboratory’s (INL) Advanced Test Reactor (ATR) to an intermediate burnup of 4 to 8 at% (2.7 - 6.8 x 1020 fiss/cm3). The tests contain metallic and nitride fuel forms with non-fertile (i.e., no uranium) and low-fertile (i.e., uranium bearing) compositions. Results of postirradiation hot cell examinations of AFC-1 irradiation tests are reported for eleven metallic alloy transmutation fuel rodlets and five nitride transmutation fuel rodlets. Non-destructive examinations included visual examination, dimensional inspection, gamma scan analysis, and neutron radiography. Detailed examinations, including fission gas puncture and analysis, metallography / ceramography and isotopics and burnup analyses, were performed on five metallic alloy and three nitride transmutation fuels. Fuel performance of both metallic alloy and nitride fuel forms was best correlated with fission density as a burnup metric rather than at.% depletion. The actinide bearing transmutation metallic alloy compositions exhibit irradiation performance very similar to U-xPu-10Zr fuel at equivalent fission densities. The irradiation performance of nitride transmutation fuels was comparable to limited data published on mixed nitride systems.

  9. Materials and system degradation in PEM fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Fowler, D. [Waterloo Univ., ON (Canada). Dept. of Chemical Engineering, Green Energy and Fuel Cell Group

    2007-07-01

    Various degradation processes in fuel cell anodes and cathodes can cause the release of fluoride ions that thin the ionomer membrane and allow more gases to permeate the cell. This presentation provided an overview of reliability modelling techniques used to identify the failure modes of material degradation in fuel cells. A reliability model of a fuel cell stack and hydrogen power system was presented in addition to solution methods for Nafion degradation of the main polymer chain. Changes in the molecular weight of Nafion were discussed. A case study of a model was used to demonstrate that reaction slowed as the ionomer on the cathode degraded. Equations were developed for hydrogen crossover, peroxide production; peroxide destruction; F-ion production; thickness change; diffusion through the gas diffusion layer (GDL); and open circuit voltage (OCV). It was concluded that the OCV durability experiments generated a mechanism for degradation of commercial membranes. The modelling study showed that degradation was related to the permeability of hydrogen to the cathode, and oxygen to the anode. It was concluded that at lower oxygen pressures anode degradation was limited, while at higher pressures anode degradation was more significant. A power point presentation of the University of Waterloo's alternative fuel team provided details of the team's recent research activities. tabs., figs.

  10. Fuel distribution

    Energy Technology Data Exchange (ETDEWEB)

    Tison, R.R.; Baker, N.R.; Blazek, C.F.

    1979-07-01

    Distribution of fuel is considered from a supply point to the secondary conversion sites and ultimate end users. All distribution is intracity with the maximum distance between the supply point and end-use site generally considered to be 15 mi. The fuels discussed are: coal or coal-like solids, methanol, No. 2 fuel oil, No. 6 fuel oil, high-Btu gas, medium-Btu gas, and low-Btu gas. Although the fuel state, i.e., gas, liquid, etc., can have a major impact on the distribution system, the source of these fuels (e.g., naturally-occurring or coal-derived) does not. Single-source, single-termination point and single-source, multi-termination point systems for liquid, gaseous, and solid fuel distribution are considered. Transport modes and the fuels associated with each mode are: by truck - coal, methanol, No. 2 fuel oil, and No. 6 fuel oil; and by pipeline - coal, methane, No. 2 fuel oil, No. 6 oil, high-Btu gas, medium-Btu gas, and low-Btu gas. Data provided for each distribution system include component makeup and initial costs.

  11. Gas-Cooled Reactor Programs annual progress report for period ending December 31, 1973. [HTGR fuel reprocessing, fuel fabrication, fuel irradiation, core materials, and fission product distribution; GCFR fuel irradiation and steam generator modeling

    Energy Technology Data Exchange (ETDEWEB)

    Kasten, P.R.; Coobs, J.H.; Lotts, A.L.

    1976-04-01

    Progress is summarized in studies relating to HTGR fuel reprocessing, refabrication, and recycle; HTGR fuel materials development and performance testing; HTGR PCRV development; HTGR materials investigations; HTGR fuel chemistry; HTGR safety studies; and GCFR irradiation experiments and steam generator modeling.

  12. High burnup fuel behavior related to fission gas effects under reactivity initiated accidents (RIA) conditions

    Science.gov (United States)

    Lemoine, F.

    1997-09-01

    Specific aspects of irradiated fuel result from the increasing retention of gaseous and volatile fission products with burnup, which, under overpower conditions, can lead to solid fuel pressurization and swelling causing severe PCMI (pellet clad mechanical interaction). In order to assess the reliability of high burnup fuel under RIAs, experimental programs have been initiated which have provided important data concerning the transient fission gas behavior and the clad loading mechanisms. The importance of the rim zone is demonstrated based on three experiments resulting in clad failure at low enthalpy, which are explained by energetic considerations. High gas release in non-failure tests with low energy deposition underlines the importance of grain boundary and porosity gas. Measured final releases are strongly correlated to the microstructure evolution, depending on energy deposition, pulse width, initial and refabricated fuel rod design. Observed helium release can also increase internal pressure and gives hints to the gas behavior understanding.

  13. Advanced Fuels Campaign Light Water Reactor Accident Tolerant Fuel Performance Metrics

    Energy Technology Data Exchange (ETDEWEB)

    Brad Merrill; Melissa Teague; Robert Youngblood; Larry Ott; Kevin Robb; Michael Todosow; Chris Stanek; Mitchell Farmer; Michael Billone; Robert Montgomery; Nicholas Brown; Shannon Bragg-Sitton

    2014-02-01

    The safe, reliable and economic operation of the nation’s nuclear power reactor fleet has always been a top priority for the United States’ nuclear industry. As a result, continual improvement of technology, including advanced materials and nuclear fuels, remains central to industry’s success. Decades of research combined with continual operation have produced steady advancements in technology and yielded an extensive base of data, experience, and knowledge on light water reactor (LWR) fuel performance under both normal and accident conditions. In 2011, following the Great East Japan Earthquake, resulting tsunami, and subsequent damage to the Fukushima Daiichi nuclear power plant complex, enhancing the accident tolerance of LWRs became a topic of serious discussion. As a result of direction from the U.S. Congress, the U.S. Department of Energy Office of Nuclear Energy (DOE-NE) initiated an Accident Tolerant Fuel (ATF) Development program. The complex multiphysics behavior of LWR nuclear fuel makes defining specific material or design improvements difficult; as such, establishing qualitative attributes is critical to guide the design and development of fuels and cladding with enhanced accident tolerance. This report summarizes a common set of technical evaluation metrics to aid in the optimization and down selection of candidate designs. As used herein, “metrics” describe a set of technical bases by which multiple concepts can be fairly evaluated against a common baseline and against one another. Furthermore, this report describes a proposed technical evaluation methodology that can be applied to assess the ability of each concept to meet performance and safety goals relative to the current UO2 – zirconium alloy system and relative to one another. The resultant ranked evaluation can then inform concept down-selection, such that the most promising accident tolerant fuel design option(s) can continue to be developed for lead test rod or lead test assembly

  14. VLSI Reliability in Europe

    NARCIS (Netherlands)

    Verweij, Jan F.

    1993-01-01

    Several issue's regarding VLSI reliability research in Europe are discussed. Organizations involved in stimulating the activities on reliability by exchanging information or supporting research programs are described. Within one such program, ESPRIT, a technical interest group on IC reliability was

  15. External fuel thermionic reactor system.

    Science.gov (United States)

    Mondt, J. F.; Peelgren, M. L.

    1971-01-01

    Thermionic reactors are prime candidates for nuclear electric propulsion. The national thermionic reactor effort is concentrated on the flashlight concept with the external-fuel concept as the backup. The external-fuel concept is very adaptable to a completely modular power subsystem which is attractive for highly reliable long-life applications. The 20- to 25-cm long, externally-fueled converters have been designed, fabricated, and successfully tested with many thermal cycles by electrical heating. However, difficulties have been encountered during encapsulation for nuclear heated tests and none have been started to date. These nuclear tests are required to demonstrate the concept feasibility.

  16. Development of spent fuel remote handling technology

    Energy Technology Data Exchange (ETDEWEB)

    Park, B. S.; Yoon, J. S.; Hong, H. D. (and others)

    2007-02-15

    In this research, the remote handling technology was developed for the ACP application. The ACP gives a possible solution to reduce the rapidly cumulative amount of spent fuels generated from the nuclear power plants in Korea. The remote technologies developed in this work are a slitting device, a voloxidizer, a modified telescopic servo manipulator and a digital mock-up. A slitting device was developed to declad the spent fuel rod-cuts and collect the spent fuel UO{sub 2} pellets. A voloxidizer was developed to convert the spent fuel UO{sub 2} pellets obtained from the slitting process in to U{sub 3}O{sub 8} powder. Experiments were performed to test the capabilities and remote operation of the developed slitting device and voloxidizer by using simulated rod-cuts and fuel in the ACP hot cell. A telescopic servo manipulator was redesigned and manufactured improving the structure of the prototype. This servo manipulator was installed in the ACP hot cell, and the target module for maintenance of the process equipment was selected. The optimal procedures for remote operation were made through the maintenance tests by using the servo manipulator. The ACP digital mockup in a virtual environment was established to secure a reliability and safety of remote operation and maintenance. The simulation for the remote operation and maintenance was implemented and the operability was analyzed. A digital mockup about the preliminary conceptual design of an enginnering-scale ACP was established, and an analysis about a scale of facility and remote handling was accomplished. The real-time diagnostic technique was developed to detect the possible fault accidents of the slitting device. An assessment of radiation effect for various sensors was also conducted in the radiation environment.

  17. Advanced Fuels Campaign Execution Plan

    Energy Technology Data Exchange (ETDEWEB)

    Kemal Pasamehmetoglu

    2011-09-01

    The purpose of the Advanced Fuels Campaign (AFC) Execution Plan is to communicate the structure and management of research, development, and demonstration (RD&D) activities within the Fuel Cycle Research and Development (FCRD) program. Included in this document is an overview of the FCRD program, a description of the difference between revolutionary and evolutionary approaches to nuclear fuel development, the meaning of science-based development of nuclear fuels, and the 'Grand Challenge' for the AFC that would, if achieved, provide a transformational technology to the nuclear industry in the form of a high performance, high reliability nuclear fuel system. The activities that will be conducted by the AFC to achieve success towards this grand challenge are described and the goals and milestones over the next 20 to 40 year period of research and development are established.

  18. Advanced Fuels Campaign Execution Plan

    Energy Technology Data Exchange (ETDEWEB)

    Kemal Pasamehmetoglu

    2010-10-01

    The purpose of the Advanced Fuels Campaign (AFC) Execution Plan is to communicate the structure and management of research, development, and demonstration (RD&D) activities within the Fuel Cycle Research and Development (FCRD) program. Included in this document is an overview of the FCRD program, a description of the difference between revolutionary and evolutionary approaches to nuclear fuel development, the meaning of science-based development of nuclear fuels, and the “Grand Challenge” for the AFC that would, if achieved, provide a transformational technology to the nuclear industry in the form of a high performance, high reliability nuclear fuel system. The activities that will be conducted by the AFC to achieve success towards this grand challenge are described and the goals and milestones over the next 20 to 40 year period of research and development are established.

  19. Alkaline fuel cells applications

    Science.gov (United States)

    Kordesch, Karl; Hacker, Viktor; Gsellmann, Josef; Cifrain, Martin; Faleschini, Gottfried; Enzinger, Peter; Fankhauser, Robert; Ortner, Markus; Muhr, Michael; Aronson, Robert R.

    On the world-wide automobile market technical developments are increasingly determined by the dramatic restriction on emissions as well as the regimentation of fuel consumption by legislation. Therefore there is an increasing chance of a completely new technology breakthrough if it offers new opportunities, meeting the requirements of resource preservation and emission restrictions. Fuel cell technology offers the possibility to excel in today's motive power techniques in terms of environmental compatibility, consumer's profit, costs of maintenance and efficiency. The key question is economy. This will be decided by the costs of fuel cell systems if they are to be used as power generators for future electric vehicles. The alkaline hydrogen-air fuel cell system with circulating KOH electrolyte and low-cost catalysed carbon electrodes could be a promising alternative. Based on the experiences of Kordesch [K. Kordesch, Brennstoffbatterien, Springer, Wien, 1984, ISBN 3-387-81819-7; K. Kordesch, City car with H 2-air fuel cell and lead-battery, SAE Paper No. 719015, 6th IECEC, 1971], who operated a city car hybrid vehicle on public roads for 3 years in the early 1970s, improved air electrodes plus new variations of the bipolar stack assembly developed in Graz are investigated. Primary fuel choice will be a major issue until such time as cost-effective, on-board hydrogen storage is developed. Ammonia is an interesting option. The whole system, ammonia dissociator plus alkaline fuel cell (AFC), is characterised by a simple design and high efficiency.

  20. A Design of Experiments (DOE) approach to optimise temperature measurement accuracy in Solid Oxide Fuel Cell (SOFC)

    Science.gov (United States)

    Barari, F.; Morgan, R.; Barnard, P.

    2014-11-01

    In SOFC, accurately measuring the hot-gas temperature is challenging due to low gas velocity, high wall temperature, complex flow geometries and relatively small pipe diameter. Improper use of low cost thermometry system such as standard Type K thermocouples (TC) may introduce large measurement error. The error could have a negative effect on the thermal management of the SOFC systems and consequential reduction in efficiency. In order to study the factors affecting the accuracy of the temperature measurement system, a mathematical model of a TC inside a pipe was defined and numerically solved. The model calculated the difference between the actual and the measured gas temperature inside the pipe. A statistical Design of Experiment (DOE) approach was applied to the modelling data to compute the interaction effect between variables and investigate the significance of each variable on the measurement errors. In this study a full factorial DOE design with six variables (wall temperature, gas temperature, TC length, TC diameter and TC emissivity) at two levels was carried out. Four different scenarios, two sets of TC length (6 - 10.5 mm and 17 - 22 mm) and two different sets of temperature range (550 - 650 °C and 750 - 850 °C), were proposed. DOE analysis was done for each scenario and results were compared to identify key parameters affecting the accuracy of a particular temperature reading.

  1. Visualization Experiments of a Specific Fuel Flow Through Quartz-glass Tubes Under both Sub-and Supercritical Conditions

    Institute of Scientific and Technical Information of China (English)

    DENG Hongwu; ZHANG Chunben; XU Guoqiang; TAO Zhi; ZHU Kun; WANG Yingjie

    2012-01-01

    The present work is a visualization study of a typical kerosene (RP-3) flowing through vertical and horizontal quartz-glass tubes under both sub- and supercritical conditions by a high speed camera.The experiments are accomplished at temperatures of 300-730 K under pressures from 0.107-5 MPa.Six distinctive two-phase flow patterns are observed in upward flow and the critical point of RP-3 is identified as critical pressure pc=2.33 MPa and critical temperature Tc=645.04 K and it is found that when the fluid pressure exceeds 2.33 MPa the flow can be considered as a single phase flow.The critical opalescence phenomenon of RP-3 is observed when the temperature is between 643.16 K and 648.61 K and the pressure is between 2.308 MPa and 2.366 MPa.The region filled by the critical opalescence in the upward flow is clearly larger than that in the downward flow due to the interaction between the buoyancy force and fluid inertia.Morecover,obvious layered flow phenomenon is observed in horizontal flow under supercritical pressures due to the differences of gravity and density.

  2. Commercialization of fuel cells: myth or reality?

    CERN Document Server

    Wang, Junye

    2014-01-01

    Despite huge investment and efforts in the last decades, fuel cells are still known as a fledgling industry after 170 years of the first fuel cell. It becomes clear that these investment and efforts did not address the critical questions. Why upscaling of fuel cells failed often when many researchers stated their successes in small scale? Why the fuel cells with simpler structure still lag far from the internal combustion (IC) engines and gas turbines? Could the current investment of the hydrogen infrastructure reduce substantially the fuel cell cost and make a breakthrough to the key issues of durability, reliability and robustness? In this paper, we study these fundamental questions and point out a must-way possible to reduce cost of fuel cells and to substantially improve durability and reliability.

  3. Dinitrogen fixation and dissolved organic nitrogen fueled primary production and particulate export during the VAHINE mesocosm experiment (New Caledonia lagoon)

    Science.gov (United States)

    Berthelot, H.; Moutin, T.; L'Helguen, S.; Leblanc, K.; Hélias, S.; Grosso, O.; Leblond, N.; Charrière, B.; Bonnet, S.

    2015-07-01

    In the oligotrophic ocean characterized by nitrate (NO3-) depletion in surface waters, dinitrogen (N2) fixation and dissolved organic nitrogen (DON) can represent significant nitrogen (N) sources for the ecosystem. In this study, we deployed large in situ mesocosms in New Caledonia in order to investigate (1) the contribution of N2 fixation and DON use to primary production (PP) and particle export and (2) the fate of the freshly produced particulate organic N (PON), i.e., whether it is preferentially accumulated and recycled in the water column or exported out of the system. The mesocosms were fertilized with phosphate (PO43-) in order to prevent phosphorus (P) limitation and promote N2 fixation. The diazotrophic community was dominated by diatom-diazotroph associations (DDAs) during the first part of the experiment for 10 days (P1) followed by the unicellular N2-fixing cyanobacteria UCYN-C for the last 9 days (P2) of the experiment. N2 fixation rates averaged 9.8 ± 4.0 and 27.7 ± 8.6 nmol L-1 d-1 during P1 and P2, respectively. NO3- concentrations ( 0.05) during P1 (9.0 ± 3.3 %) and P2 (12.6 ± 6.1 %). However, the e ratio that quantifies the efficiency of a system to export particulate organic carbon (POCexport) compared to PP (e ratio = POCexport/PP) was significantly higher (p efficient at promoting C export than the production sustained by DDAs. During P1, PON was stable and the total amount of N provided by N2 fixation (0.10 ± 0.02 μmol L-1) was not significantly different (p > 0.05) from the total amount of PON exported (0.10 ± 0.04 μmol L-1), suggesting a rapid and probably direct export of the recently fixed N2 by the DDAs. During P2, both PON concentrations and PON export increased in the mesocosms by a factor 1.5-2. Unlike in P1, this PON production was not totally explained by the new N provided by N2 fixation. The use of DON, whose concentrations decreased significantly (p < 0.05) from 5.3 ± 0.5 μmol L-1 to 4.4 ± 0.5 μmol L-1, appeared to

  4. Injection of zinc in plants of ANAV. Impact on fuel and operation experience; Inyeccion de cinc en las plantas de ANAV. Impacto sobre el combustible y experiencia de operacion

    Energy Technology Data Exchange (ETDEWEB)

    Doncell, N.; Gago, J. L.

    2015-07-01

    Zinc injection performed in the three ANAV (Asociacion Nuclear Asco-Vandellos) plants is part of an overall primary water chemistry program, material management and dose reduction program. The application of zinc shown significant benefits in radiation field reduction as well as in mitigation of PWSCC initiation. Although zinc injection also reduces general corrosion rates and consequently reduces corrosion product transport to the fuel, and evaluation of the risks with respect to fuel performance should be done. ANAV and ENUSA, following industry recommendations, have coordinated the task related to the viability of the program in Asco and Vandellos including monitoring, inspections and control parameters. finally, this article includes a comprehensive review of operating experience and an assessment of fuel performance effects. (Author)

  5. Continuous improvement in manufacturing and inspection of fuel; Mejora continua en fabricacion e inspeccion de combustible

    Energy Technology Data Exchange (ETDEWEB)

    Domingon, A.; Ruiz, R.

    2015-07-01

    The manufacturing and inspection process of fuel assemblies in ENUSA is characterized by its robustness acquired over the last thirty years of experience in manufacturing. The reliability of these processes is based on a qualified processes and continuous improvement in the design and upgrading of equipment and optimization of software and manufacturing processes. Additionally, management and quality control systems have been improved in both software and measuring business objectives. this article emphasizes the improvements made over the past five years in management, production and inspection of fuel assemblies. (Author)

  6. Fuel Cells

    DEFF Research Database (Denmark)

    Smith, Anders; Pedersen, Allan Schrøder

    2014-01-01

    Fuel cells have been the subject of intense research and development efforts for the past decades. Even so, the technology has not had its commercial breakthrough yet. This entry gives an overview of the technological challenges and status of fuel cells and discusses the most promising applications...... of the different types of fuel cells. Finally, their role in a future energy supply with a large share of fluctuating sustainable power sources, e.g., solar or wind, is surveyed....

  7. Issues related to the construction and operation of a geological disposal facility for nuclear fuel waste in crystalline rock - the Canadian experience

    Energy Technology Data Exchange (ETDEWEB)

    Allan, C.J.; Baumgartner, P.; Ohta, M.M.; Simmons, G.R.; Whitaker, S.H. [Atomic Energy of Canada Ltd., Pinawa, MB (Canada). Whiteshell Labs

    1997-12-31

    This paper covers the overview of the Canadian nuclear fuel waste management program, the general approach to the siting, design, construction, operation and closure of a geological disposal facility, the implementing disposal, and the public involvement in implementing geological disposal of nuclear fuel waste. And two appendices are included. 45 refs., 5 tabs., 10 figs.

  8. Fabrication and Pre-irradiation Characterization of a Minor Actinide and Rare Earth Containing Fast Reactor Fuel Experiment for Irradiation in the Advanced Test Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Timothy A. Hyde

    2012-06-01

    The United States Department of Energy, seeks to develop and demonstrate the technologies needed to transmute the long-lived transuranic actinide isotopes contained in spent nuclear fuel into shorter lived fission products, thereby decreasing the volume of material requiring disposal and reducing the long-term radiotoxicity and heat load of high-level waste sent to a geologic repository. This transmutation of the long lived actinides plutonium, neptunium, americium and curium can be accomplished by first separating them from spent Light Water Reactor fuel using a pyro-metalurgical process, then reprocessing them into new fuel with fresh uranium additions, and then transmuted to short lived nuclides in a liquid metal cooled fast reactor. An important component of the technology is developing actinide-bearing fuel forms containing plutonium, neptunium, americium and curium isotopes that meet the stringent requirements of reactor fuels and materials.

  9. Reliability Generalization: "Lapsus Linguae"

    Science.gov (United States)

    Smith, Julie M.

    2011-01-01

    This study examines the proposed Reliability Generalization (RG) method for studying reliability. RG employs the application of meta-analytic techniques similar to those used in validity generalization studies to examine reliability coefficients. This study explains why RG does not provide a proper research method for the study of reliability,…

  10. Reliability-Based Optimization in Structural Engineering

    DEFF Research Database (Denmark)

    Enevoldsen, I.; Sørensen, John Dalsgaard

    1994-01-01

    -based optimal inspection planning and reliability-based experiment planning. It is explained how these optimization problems can be solved by application of similar techniques. The reliability estimation is limited to first order reliability methods (FORM) for both component and systems reliability evaluation......, inclusion of the finite element method as the response evaluation tool and how the size of the problem can be made practicable. Finally, the important task of model evaluation and sensitivity analysis of the optimal solution is treated including a strategy for model-making with both pre and post-analysis.......In this paper reliability-based optimization problems in structural engineering are formulated on the basis of the classical decision theory. Several formulations are presented: Reliability-based optimal design of structural systems with component or systems reliability constraints, reliability...

  11. Improve of the adequacy and reliability of no standardized processing model datasets in studies of educational systems method of experiment planning

    Directory of Open Access Journals (Sweden)

    Valery Alexeev

    2014-06-01

    Full Text Available The article is devoted the questions of improvement of the accuracy of statistical mathematical models, used to investigate the effectiveness of the educational process. The authors suggest changing standard approaches to information processing large datasets, using the method of experiment planning. This takes into account features of data sets characteristic of pedagogical processes. Using these proposals one can improve the accuracy of the model and the value processing, and hence the accuracy of machining.

  12. Enhanced Accident Tolerant LWR Fuels National Metrics Workshop Report

    Energy Technology Data Exchange (ETDEWEB)

    Lori Braase

    2013-01-01

    The U.S. Department of Energy Office of Nuclear Energy (DOE-NE), in collaboration with the nuclear industry, has been conducting research and development (R&D) activities on advanced Light Water Reactor (LWR) fuels for the last few years. The emphasis for these activities was on improving the fuel performance in terms of increased burnup for waste minimization and increased power density for power upgrades, as well as collaborating with industry on fuel reliability. After the events at the Fukushima Nuclear Power Plant in Japan in March 2011, enhancing the accident tolerance of LWRs became a topic of serious discussion. In the Consolidated Appropriations Act, 2012, Conference Report 112-75, the U.S. Congress directed DOE-NE to: • Give “priority to developing enhanced fuels and cladding for light water reactors to improve safety in the event of accidents in the reactor or spent fuel pools.” • Give “special technical emphasis and funding priority…to activities aimed at the development and near-term qualification of meltdown-resistant, accident-tolerant nuclear fuels that would enhance the safety of present and future generations of light water reactors.” • Report “to the Committee, within 90 days of enactment of this act, on its plan for development of meltdown-resistant fuels leading to reactor testing and utilization by 2020.” Fuels with enhanced accident tolerance are those that, in comparison with the standard UO2-zirconium alloy system currently used by the nuclear industry, can tolerate loss of active cooling in the reactor core for a considerably longer time period (depending on the LWR system and accident scenario) while maintaining or improving the fuel performance during normal operations, and operational transients, as well as design-basis and beyond design-basis events. The overall draft strategy for development and demonstration is comprised of three phases: Feasibility Assessment and Down-selection; Development and Qualification; and

  13. Procuring Stationary Fuel Cells For CHP: A Guide for Federal Facility Decision Makers

    Energy Technology Data Exchange (ETDEWEB)

    Stinton, David P [ORNL; McGervey, Joseph [SRA International, Inc.; Curran, Scott [ORNL

    2011-11-01

    Federal agency leaders are expressing growing interest in using innovative fuel cell combined heat and power (CHP) technology at their sites, motivated by both executive branch sustainability targets and a desire to lead by example in the transition to a clean energy economy. Fuel cell CHP can deliver reliable electricity and heat with 70% to 85% efficiency. Implementing this technology can be a high efficiency, clean energy solution for agencies striving to meet ambitious sustainability requirements with limited budgets. Fuel cell CHP systems can use natural gas or renewable fuels, such as biogas. Procuring Stationary Fuel Cells for CHP: A Guide for Federal Facility Decision Makers presents an overview of the process for planning and implementing a fuel cell CHP project in a concise, step-by-step format. This guide is designed to help agency leaders turn their interest in fuel cell technology into successful installations. This guide concentrates on larger (100 kW and greater) fuel cell CHP systems and does not consider other fuel cell applications such as cars, forklifts, backup power supplies or small generators (<100 kW). Because fuel cell technologies are rapidly evolving and have high up front costs, their deployment poses unique challenges. The electrical and thermal output of the CHP system must be integrated with the building s energy systems. Innovative financing mechanisms allow agencies to make a make versus buy decision to maximize savings. This guide outlines methods that federal agencies may use to procure fuel cell CHP systems with little or no capital investment. Each agency and division, however, has its own set of procurement procedures. This guide was written as a starting point, and it defers to the reader s set of rules if differences exist. The fuel cell industry is maturing, and project developers are gaining experience in working with federal agencies. Technology improvements, cost reductions, and experienced project developers are making

  14. 运动机构可靠性仿真试验系统体系结构研究%Research on the Architecture of Simulative Experiment System for Mechanism Motion Reliability Analysis

    Institute of Scientific and Technical Information of China (English)

    王慧; 喻天翔; 雷鸣敏; 宋笔锋

    2011-01-01

    针对工程实际复杂运动机构系统成本高、研制周期长、试验量少等特点,提出基于机液协同仿真模型的运动机构可靠性仿真分析方法.从工程实际运动机构系统的运动规律和系统性能出发,给出系统的主要失效模式并定量确定主要失效模式的失效判据,通过整合运动机构系统仿真模型可靠性分析的数据来源,建立并不断修正运动机构系统可靠性仿真模型,同时综合集成三维辅助建模软件、多体分析软件、有限元软件和控制系统建模软件等商用软件并结合经典可靠性分析方法,建立一个协同的运动机构可靠性仿真试验平台集成系统,从而对运动机构系统进行可靠性仿真试验分析与评估,为今后可靠性设计提供大量的有用信息.通过起落架落震可靠性仿真试验研究,表明该系统能够实现工程实际复杂运动机构可靠性仿真试验.%The complex engineering mechanisms are usually of high cost, long term schedules, and small number of experimental specimens. In order to deal with the problem, a hybrid simulative method for mechanism motion reliability analysis is proposed based on the mechanic-liquid coupling model. Considering the rule of movement and performance of the engineering mechanism system, the principal failure modes are defined and the corresponding failure criterions are determined quantitatively. The simulative model is built and updated by integration of data source for mechanism motion reliability analysis. Using the integration of commercial software, including 3D CAD software, multi-body analysis software, finite element analysis software and control system modeling software, and combining with the classic reliability analysis method, an integrated platform of simulative experiment system for mechanism motion reliability analysis is developed. The simulative experiment analysis and evaluation of the mechanism motion reliability can be performed, and

  15. Alternative Fuels: Research Progress

    Directory of Open Access Journals (Sweden)

    Maher A.R. Sadiq Al-Baghdadi

    2013-01-01

    Full Text Available Chapter 1: Pollutant Emissions and Combustion Characteristics of Biofuels and Biofuel/Diesel Blends in Laminar and Turbulent Gas Jet Flames. R. N. Parthasarathy, S. R. Gollahalli Chapter 2: Sustainable Routes for The Production of Oxygenated High-Energy Density Biofuels from Lignocellulosic Biomass. Juan A. Melero, Jose Iglesias, Gabriel Morales, Marta Paniagua Chapter 3: Optical Investigations of Alternative-Fuel Combustion in an HSDI Diesel Engine. T. Huelser, M. Jakob, G. Gruenefeld, P. Adomeit, S. Pischinger Chapter 4: An Insight into Biodiesel Physico-Chemical Properties and Exhaust Emissions Based on Statistical Elaboration of Experimental Data. Evangelos G. Giakoumis Chapter 5: Biodiesel: A Promising Alternative Energy Resource. A.E. Atabani Chapter 6: Alternative Fuels for Internal Combustion Engines: An Overview of the Current Research. Ahmed A. Taha, Tarek M. Abdel-Salam, Madhu Vellakal Chapter 7: Investigating the Hydrogen-Natural Gas Blends as a Fuel in Internal Combustion Engine. ?lker YILMAZ Chapter 8: Conversion of Bus Diesel Engine into LPG Gaseous Engine; Method and Experiments Validation. M. A. Jemni , G. Kantchev , Z. Driss , R. Saaidia , M. S. Abid Chapter 9: Predicting the Combustion Performance of Different Vegetable Oils-Derived Biodiesel Fuels. Qing Shu, ChangLin Yu Chapter 10: Production of Gasoline, Naphtha, Kerosene, Diesel, and Fuel Oil Range Fuels from Polypropylene and Polystyrene Waste Plastics Mixture by Two-Stage Catalytic Degradation using ZnO. Moinuddin Sarker, Mohammad Mamunor Rashid

  16. Nalco Fuel Tech

    Energy Technology Data Exchange (ETDEWEB)

    Michalak, S.

    1995-12-31

    The Nalco Fuel Tech with its seat at Naperville (near Chicago), Illinois, is an engineering company working in the field of technology and equipment for environmental protection. A major portion of NALCO products constitute chemical materials and additives used in environmental protection technologies (waste-water treatment plants, water treatment, fuel modifiers, etc.). Basing in part on the experience, laboratories and RD potential of the mother company, the Nalco Fuel Tech Company developed and implemented in the power industry a series of technologies aimed at the reduction of environment-polluting products of fuel combustion. The engineering solution of Nalco Fuel Tech belong to a new generation of environmental protection techniques developed in the USA. They consist in actions focused on the sources of pollutants, i.e., in upgrading the combustion chambers of power engineering plants, e.g., boilers or communal and/or industrial waste combustion units. The Nalco Fuel Tech development and research group cooperates with leading US investigation and research institutes.

  17. Motor Fuel Excise Taxes

    Energy Technology Data Exchange (ETDEWEB)

    2015-09-01

    A new report from the National Renewable Energy Laboratory (NREL) explores the role of alternative fuels and energy efficient vehicles in motor fuel taxes. Throughout the United States, it is common practice for federal, state, and local governments to tax motor fuels on a per gallon basis to fund construction and maintenance of our transportation infrastructure. In recent years, however, expenses have outpaced revenues creating substantial funding shortfalls that have required supplemental funding sources. While rising infrastructure costs and the decreasing purchasing power of the gas tax are significant factors contributing to the shortfall, the increased use of alternative fuels and more stringent fuel economy standards are also exacerbating revenue shortfalls. The current dynamic places vehicle efficiency and petroleum use reduction polices at direct odds with policies promoting robust transportation infrastructure. Understanding the energy, transportation, and environmental tradeoffs of motor fuel tax policies can be complicated, but recent experiences at the state level are helping policymakers align their energy and environmental priorities with highway funding requirements.

  18. Using fine-scale fuel measurements to assess wildland fuels, potential fire behavior and hazard mitigation treatments in the southeastern USA

    Science.gov (United States)

    Roger D. Ottmar; John I. Blake; William T. Crolly

    2012-01-01

    The inherent spatial and temporal heterogeneity of fuel beds in forests of the southeastern United States may require fine scale fuel measurements for providing reliable fire hazard and fuel treatment effectiveness estimates. In a series of five papers, an intensive, fine scale fuel inventory from the Savanna River Site in the southeastern United States is used for...

  19. Enhanced Accident Tolerant LWR Fuels: Metrics Development

    Energy Technology Data Exchange (ETDEWEB)

    Shannon Bragg-Sitton; Lori Braase; Rose Montgomery; Chris Stanek; Robert Montgomery; Lance Snead; Larry Ott; Mike Billone

    2013-09-01

    The Department of Energy (DOE) Fuel Cycle Research and Development (FCRD) Advanced Fuels Campaign (AFC) is conducting research and development on enhanced Accident Tolerant Fuels (ATF) for light water reactors (LWRs). This mission emphasizes the development of novel fuel and cladding concepts to replace the current zirconium alloy-uranium dioxide (UO2) fuel system. The overall mission of the ATF research is to develop advanced fuels/cladding with improved performance, reliability and safety characteristics during normal operations and accident conditions, while minimizing waste generation. The initial effort will focus on implementation in operating reactors or reactors with design certifications. To initiate the development of quantitative metrics for ATR, a LWR Enhanced Accident Tolerant Fuels Metrics Development Workshop was held in October 2012 in Germantown, MD. This paper summarizes the outcome of that workshop and the current status of metrics development for LWR ATF.

  20. Inspection of state of spent fuel elements stored in RA reactor spent fuel storage pool

    Energy Technology Data Exchange (ETDEWEB)

    Aden, V.G.; Bulkin, S.Yu.; Sokolov, A.V. [Research and Development Institute of Power Engineering, Moscow (Russian Federation); Matausek, M.V.; Vukadin, Z. [VINCA Institute of Nuclear Science, Belgrade (Yugoslavia)

    1999-07-01

    About five thousand spent fuel elements from RA reactor have been stored for over 30 years in sealed aluminum barrels in the spent fuel storage pool. This way of storage does not provide complete information about the state of spent fuel elements or the medium inside the barrels, like pressure or radioactivity. The technology has recently been developed and the equipment has been manufactured to inspect the state of the spent fuel and to reduce eventual internal pressure inside the aluminum barrels. Based on the results of this inspection, a procedure will be proposed for transferring spent fuel to a more reliable storage facility. (author)

  1. Assuring reliability program effectiveness.

    Science.gov (United States)

    Ball, L. W.

    1973-01-01

    An attempt is made to provide simple identification and description of techniques that have proved to be most useful either in developing a new product or in improving reliability of an established product. The first reliability task is obtaining and organizing parts failure rate data. Other tasks are parts screening, tabulation of general failure rates, preventive maintenance, prediction of new product reliability, and statistical demonstration of achieved reliability. Five principal tasks for improving reliability involve the physics of failure research, derating of internal stresses, control of external stresses, functional redundancy, and failure effects control. A final task is the training and motivation of reliability specialist engineers.

  2. The Accelerator Reliability Forum

    CERN Document Server

    Lüdeke, Andreas; Giachino, R

    2014-01-01

    A high reliability is a very important goal for most particle accelerators. The biennial Accelerator Reliability Workshop covers topics related to the design and operation of particle accelerators with a high reliability. In order to optimize the over-all reliability of an accelerator one needs to gather information on the reliability of many different subsystems. While a biennial workshop can serve as a platform for the exchange of such information, the authors aimed to provide a further channel to allow for a more timely communication: the Particle Accelerator Reliability Forum [1]. This contribution will describe the forum and advertise it’s usage in the community.

  3. Combustion studies of coal-derived solid fuels. Part IV. Correlation of ignition temperatures from thermogravimetry and free-floating experiments

    Science.gov (United States)

    Rostam-Abadi, M.; DeBarr, J.A.; Chen, W.T.

    1992-01-01

    The usefulness of TG as an efficient and practical method to characterize the combustion properties of fuels used in large-scale combustors is of considerable interest. Relative ignition temperatures of a lignite, an anthracite, a bituminous coal and three chars derived from this coal were measured by a free-floating technique. These temperatures were correlated with those estimated from TG burning profiles of the fuels. ?? 1992.

  4. Enlightenment on Computer Network Reliability From Transportation Network Reliability

    OpenAIRE

    Hu Wenjun; Zhou Xizhao

    2011-01-01

    Referring to transportation network reliability problem, five new computer network reliability definitions are proposed and discussed. They are computer network connectivity reliability, computer network time reliability, computer network capacity reliability, computer network behavior reliability and computer network potential reliability. Finally strategies are suggested to enhance network reliability.

  5. Fuel cells:

    DEFF Research Database (Denmark)

    Sørensen, Bent

    2013-01-01

    A brief overview of the progress in fuel cell applications and basic technology development is presented, as a backdrop for discussing readiness for penetration into the marketplace as a solution to problems of depletion, safety, climate or environmental impact from currently used fossil and nucl......A brief overview of the progress in fuel cell applications and basic technology development is presented, as a backdrop for discussing readiness for penetration into the marketplace as a solution to problems of depletion, safety, climate or environmental impact from currently used fossil...... and nuclear fuel-based energy technologies....

  6. Operational limitations of light water reactors relating to fuel performance

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, H S

    1976-07-01

    General aspects of fuel performance for typical Boiling and Pressurized Water Reactors are presented. Emphasis is placed on fuel failures in order to make clear important operational limitations. A discussion of fuel element designs is first given to provide the background information for the subsequent discussion of several fuel failure modes that have been identified. Fuel failure experiences through December 31, 1974, are summarized. The operational limitations that are required to mitigate the effects of fuel failures are discussed.

  7. Operational limitations of light water reactors relating to fuel performance

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, H S

    1976-07-01

    General aspects of fuel performance for typical Boiling and Pressurized Water Reactors are presented. Emphasis is placed on fuel failures in order to make clear important operational limitations. A discussion of fuel element designs is first given to provide the background information for the subsequent discussion of several fuel failure modes that have been identified. Fuel failure experiences through December 31, 1974, are summarized. The operational limitations that are required to mitigate the effects of fuel failures are discussed.

  8. Human Reliability Program Overview

    Energy Technology Data Exchange (ETDEWEB)

    Bodin, Michael

    2012-09-25

    This presentation covers the high points of the Human Reliability Program, including certification/decertification, critical positions, due process, organizational structure, program components, personnel security, an overview of the US DOE reliability program, retirees and academia, and security program integration.

  9. Power electronics reliability analysis.

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Mark A.; Atcitty, Stanley

    2009-12-01

    This report provides the DOE and industry with a general process for analyzing power electronics reliability. The analysis can help with understanding the main causes of failures, downtime, and cost and how to reduce them. One approach is to collect field maintenance data and use it directly to calculate reliability metrics related to each cause. Another approach is to model the functional structure of the equipment using a fault tree to derive system reliability from component reliability. Analysis of a fictitious device demonstrates the latter process. Optimization can use the resulting baseline model to decide how to improve reliability and/or lower costs. It is recommended that both electric utilities and equipment manufacturers make provisions to collect and share data in order to lay the groundwork for improving reliability into the future. Reliability analysis helps guide reliability improvements in hardware and software technology including condition monitoring and prognostics and health management.

  10. Reliable Design Versus Trust

    Science.gov (United States)

    Berg, Melanie; LaBel, Kenneth A.

    2016-01-01

    This presentation focuses on reliability and trust for the users portion of the FPGA design flow. It is assumed that the manufacturer prior to hand-off to the user tests FPGA internal components. The objective is to present the challenges of creating reliable and trusted designs. The following will be addressed: What makes a design vulnerable to functional flaws (reliability) or attackers (trust)? What are the challenges for verifying a reliable design versus a trusted design?

  11. BioSAXS Sample Changer: a robotic sample changer for rapid and reliable high-throughput X-ray solution scattering experiments

    Energy Technology Data Exchange (ETDEWEB)

    Round, Adam, E-mail: around@embl.fr; Felisaz, Franck [European Molecular Biology Laboratory, Grenoble Outstation, 71 Avenue des Martyrs, CS 90181, 38042 Grenoble (France); Université Grenoble Alpes–EMBL–CNRS, 71 Avenue des Martyrs, CS 90181, 38042 Grenoble (France); Fodinger, Lukas; Gobbo, Alexandre [European Molecular Biology Laboratory, Grenoble Outstation, 71 Avenue des Martyrs, CS 90181, 38042 Grenoble (France); Huet, Julien [European Molecular Biology Laboratory, Grenoble Outstation, 71 Avenue des Martyrs, CS 90181, 38042 Grenoble (France); Université Grenoble Alpes–EMBL–CNRS, 71 Avenue des Martyrs, CS 90181, 38042 Grenoble (France); Villard, Cyril [European Molecular Biology Laboratory, Grenoble Outstation, 71 Avenue des Martyrs, CS 90181, 38042 Grenoble (France); Blanchet, Clement E., E-mail: around@embl.fr [EMBL c/o DESY, Notkestrasse 85, 22603 Hamburg (Germany); Pernot, Petra; McSweeney, Sean [ESRF, 6 Rue Jules Horowitz, 38000 Grenoble (France); Roessle, Manfred; Svergun, Dmitri I. [EMBL c/o DESY, Notkestrasse 85, 22603 Hamburg (Germany); Cipriani, Florent, E-mail: around@embl.fr [European Molecular Biology Laboratory, Grenoble Outstation, 71 Avenue des Martyrs, CS 90181, 38042 Grenoble (France); Université Grenoble Alpes–EMBL–CNRS, 71 Avenue des Martyrs, CS 90181, 38042 Grenoble (France)

    2015-01-01

    A robotic sample changer for solution X-ray scattering experiments optimized for speed and to use the minimum amount of material has been developed. This system is now in routine use at three high-brilliance European synchrotron sites, each capable of several hundred measurements per day. Small-angle X-ray scattering (SAXS) of macromolecules in solution is in increasing demand by an ever more diverse research community, both academic and industrial. To better serve user needs, and to allow automated and high-throughput operation, a sample changer (BioSAXS Sample Changer) that is able to perform unattended measurements of up to several hundred samples per day has been developed. The Sample Changer is able to handle and expose sample volumes of down to 5 µl with a measurement/cleaning cycle of under 1 min. The samples are stored in standard 96-well plates and the data are collected in a vacuum-mounted capillary with automated positioning of the solution in the X-ray beam. Fast and efficient capillary cleaning avoids cross-contamination and ensures reproducibility of the measurements. Independent temperature control for the well storage and for the measurement capillary allows the samples to be kept cool while still collecting data at physiological temperatures. The Sample Changer has been installed at three major third-generation synchrotrons: on the BM29 beamline at the European Synchrotron Radiation Facility (ESRF), the P12 beamline at the PETRA-III synchrotron (EMBL@PETRA-III) and the I22/B21 beamlines at Diamond Light Source, with the latter being the first commercial unit supplied by Bruker ASC.

  12. Assessment of spent fuel cooling

    Energy Technology Data Exchange (ETDEWEB)

    Ibarra, J.G.; Jones, W.R.; Lanik, G.F. [and others

    1997-02-01

    The paper presents the methodology, the findings, and the conclusions of a study that was done by the Nuclear Regulatory Commission`s Office for Analysis and Evaluation of Operational Data (AEOD) on loss of spent fuel pool cooling. The study involved an examination of spent fuel pool designs, operating experience, operating practices, and procedures. AEOD`s work was augmented in the area of statistics and probabilistic risk assessment by experts from the Idaho Nuclear Engineering Laboratory. Operating experience was integrated into a probabilistic risk assessment to gain insight on the risks from spent fuel pools.

  13. A method for limitation of probability of accumulation of fuel elements claddings damage in WWER

    OpenAIRE

    Sergey N. Pelykh; Mark V. Nikolsky; S. D. Ryabchikov

    2014-01-01

    The aim is to reduce the probability of accumulation of fuel elements claddings damage by developing a method to control the properties of the fuel elements on stages of design and operation of WWER. An averaged over the fuel assembly WWER-1000 fuel element is considered. The probability of depressurization of fuel elements claddings is found. The ability to predict the reliability of claddings by controlling the factors that determine the properties of the fuel elements is proved. The expedi...

  14. Viking Lander reliability program

    Science.gov (United States)

    Pilny, M. J.

    1978-01-01

    The Viking Lander reliability program is reviewed with attention given to the development of the reliability program requirements, reliability program management, documents evaluation, failure modes evaluation, production variation control, failure reporting and correction, and the parts program. Lander hardware failures which have occurred during the mission are listed.

  15. Fuel cells

    Directory of Open Access Journals (Sweden)

    D. N. Srivastava

    1962-05-01

    Full Text Available The current state of development of fuel cells as potential power sources is reviewed. Applications in special fields with particular reference to military requirements are pointed out.

  16. Is quantitative electromyography reliable?

    Science.gov (United States)

    Cecere, F; Ruf, S; Pancherz, H

    1996-01-01

    The reliability of quantitative electromyography (EMG) of the masticatory muscles was investigated in 14 subjects without any signs or symptoms of temporomandibular disorders. Integrated EMG activity from the anterior temporalis and masseter muscles was recorded bilaterally by means of bipolar surface electrodes during chewing and biting activities. In the first experiment, the influence of electrode relocation was investigated. No influence of electrode relocation on the recorded EMG signal could be detected. In a second experiment, three sessions of EMG recordings during five different chewing and biting activities were performed in the morning (I); 1 hour later without intermediate removal of the electrodes (II); and in the afternoon, using new electrodes (III). The method errors for different time intervals (I-II and I-III errors) for each muscle and each function were calculated. Depending on the time interval between the EMG recordings, the muscles considered, and the function performed, the individual errors ranged from 5% to 63%. The method error increased significantly (P masseter (mean 27.2%) was higher than for the temporalis (mean 20.0%). The largest function error was found during maximal biting in intercuspal position (mean 23.1%). Based on the findings, quantitative electromyography of the masticatory muscles seems to have a limited value in diagnostics and in the evaluation of individual treatment results.

  17. Future Fuels

    Science.gov (United States)

    2006-04-01

    Storage Devices, Fuel Management, Gasification, Fischer-Tropsch, Syngas , Hubberts’s Peak UNCLAS UNCLAS UNCLAS UU 80 Dr. Sujata Millick (703) 696...prices ever higher, and perhaps lead to intermittent fuel shortages as production fluctuates. Clearly, this competition for resources also provides oil...producers multiple options for selling their products, and raises the possibility that the US could face shortages resulting from shifts in

  18. Effects of mixing system and pilot fuel quality on diesel-biogas dual fuel engine performance.

    Science.gov (United States)

    Bedoya, Iván Darío; Arrieta, Andrés Amell; Cadavid, Francisco Javier

    2009-12-01

    This paper describes results obtained from CI engine performance running on dual fuel mode at fixed engine speed and four loads, varying the mixing system and pilot fuel quality, associated with fuel composition and cetane number. The experiments were carried out on a power generation diesel engine at 1500 m above sea level, with simulated biogas (60% CH(4)-40% CO(2)) as primary fuel, and diesel and palm oil biodiesel as pilot fuels. Dual fuel engine performance using a naturally aspirated mixing system and diesel as pilot fuel was compared with engine performance attained with a supercharged mixing system and biodiesel as pilot fuel. For all loads evaluated, was possible to achieve full diesel substitution using biogas and biodiesel as power sources. Using the supercharged mixing system combined with biodiesel as pilot fuel, thermal efficiency and substitution of pilot fuel were increased, whereas methane and carbon monoxide emissions were reduced.

  19. CALCULATION OF STRESS AND DEFORMATION IN FUEL ROD CLADDING DURING PELLET-CLADDING INTERACTION

    Directory of Open Access Journals (Sweden)

    Dávid Halabuk

    2015-12-01

    Full Text Available The elementary parts of every fuel assembly, and thus of the reactor core, are fuel rods. The main function of cladding is hermetic separation of nuclear fuel from coolant. The fuel rod works in very specific and difficult conditions, so there are high requirements on its reliability and safety. During irradiation of fuel rods, a state may occur when fuel pellet and cladding interact. This state is followed by changes of stress and deformations in the fuel cladding. The article is focused on stress and deformation analysis of fuel cladding, where two fuels are compared: a fresh one and a spent one, which is in contact with cladding. The calculations are done for 4 different shapes of fuel pellets. It is possible to evaluate which shape of fuel pellet is the most appropriate in consideration of stress and deformation forming in fuel cladding, axial dilatation of fuel, and radial temperature distribution in the fuel rod, based on the obtained results.

  20. Portable fuel cell power sources for various applications

    Energy Technology Data Exchange (ETDEWEB)

    Daugherty, Mark; Kenyon, Ken; Jackson, Greg [Enable Fuel Cell Corporation, Middleton, WI 53562 (US)] (and others)

    2001-07-01

    The Enable Fuel Cell Corporation is developing proton exchange membrane (PEM) fuel cells ranging in size from a fraction of a Watt to several kilowatts. Our goal is to develop efficient, reliable and cost effective fuel cells, suitable for meeting the day-to-day needs of users in the industrial and consumer power markets. In this paper we present results of testing and initial field deployment of several different fuel cell systems. (author)

  1. Multiple Irradiation Capsule Experiment (MICE)-3B Irradiation Test of Space Fuel Specimens in the Advanced Test Reactor (ATR) - Close Out Documentation for Naval Reactors (NR) Information

    Energy Technology Data Exchange (ETDEWEB)

    M. Chen; CM Regan; D. Noe

    2006-01-09

    Few data exist for UO{sub 2} or UN within the notional design space for the Prometheus-1 reactor (low fission rate, high temperature, long duration). As such, basic testing is required to validate predictions (and in some cases determine) performance aspects of these fuels. Therefore, the MICE-3B test of UO{sub 2} pellets was designed to provide data on gas release, unrestrained swelling, and restrained swelling at the upper range of fission rates expected for a space reactor. These data would be compared with model predictions and used to determine adequacy of a space reactor design basis relative to fission gas release and swelling of UO{sub 2} fuel and to assess potential pellet-clad interactions. A primary goal of an irradiation test for UN fuel was to assess performance issues currently associated with this fuel type such as gas release, swelling and transient performance. Information learned from this effort may have enabled use of UN fuel for future applications.

  2. Experience gained from carrying out ultrasonic cleaning of fuel assemblies and control and protection system assemblies in the Novovoronezh NPP unit 3

    Science.gov (United States)

    Gorburov, V. I.; Shvarov, V. A.; Vitkovskii, S. L.

    2014-02-01

    A growth of deposits on fuel assembly elements was revealed during operation of the Novovoronezh NPP Unit 3 starting from 1997. This growth caused progressive reduction of coolant flow rate through the reactor core and increase of pressure difference across the assemblies, which eventually led to the need to reduce the power unit output and then to shut down the power unit. In view of these circumstances, it was decided to develop an installation for ultrasonic cleaning of fuel assemblies. The following conclusions were drawn with regard of this installation after completion of all stages of its development, commissioning, and improvement: no detrimental effect of ultrasound on the integrity of fuel assemblies was revealed, whereas the cleaning effect on the fuel assemblies subjected to ultrasonic treatment and improvement of their thermal-hydraulic characteristics are obvious. With these measures implemented, it became possible to clean all fuel assemblies in the core in 2011, to achieve better thermal-hydraulic characteristics, and to avoid reduction of power output and off-scheduled outages of Unit 3.

  3. Proceedings of the fifth international conference on CANDU fuel. V.1,2

    Energy Technology Data Exchange (ETDEWEB)

    Lau, J.H. [ed.

    1997-07-01

    The First International Conference on CANDU Fuel was held in Chalk River in 1986. The CANDU Fuel community has gathered every three years since. The papers presented include topics on international experience, CANFLEX fuel bundles, Fuel design, Fuel modelling, Manufacturing and Quality assurance, Fuel performance and Safety, Fuel cycles and Spent Fuel management. Volume One was published in advance of the conference and Volume Two was printed after the conference.

  4. Reliability in Cross-National Content Analysis.

    Science.gov (United States)

    Peter, Jochen; Lauf, Edmund

    2002-01-01

    Investigates how coder characteristics such as language skills, political knowledge, coding experience, and coding certainty affected inter-coder and coder-training reliability. Shows that language skills influenced both reliability types. Suggests that cross-national researchers should pay more attention to cross-national assessments of…

  5. Rare extragonadal teratomas in children: complete tumor excision as a reliable and essential procedure for significant survival. Clinical experience and review of the literature.

    Science.gov (United States)

    Paradies, Guglielmo; Zullino, Francesca; Orofino, Antonio; Leggio, Samuele

    2014-01-01

    Extragonadal teratomas are rare tumors in neonates and infants and can sometimes show unusual, distinctive feature such as an unusual location, a clinical sometimes acute, presentation and a "fetiform" histotype of the lesion. We have extrapolated, from our entire experience of teratomas, 4 unusual cases, mostly operated as emergencies; 2 of them were treated just after birth. Aim of this paper is to report the clinical and pathological findings, to evaluate the surgical approach and the long-term biological behaviour in these cases, in the light of survival and current insights reported in the literature. The Authors reviewed the most significant (Tables I and II) clinical, laboratory, radiologic, and pathologic findings, surgical procedures, early and long-term results in 4 children, 1 male and 3 females (M/F ratio: 1/3), suffering from extragonadal teratomas, located in the temporo-zygomatic region of the head (Case n. 1, Fig. 1), retroperitoneal space (Case n. 2, Fig. 2) ,liver (Case n. 3, Figg. 3-5), kidney (Case n. 4, Fig. 6, 7), respectively. Of the 4 patients, 2 were treated neonatally (1 T. of the head, 1 retroperitoneal T.) A prenatal diagnosis had already been made in 2 of the 4 patients, between the 2nd and 3rd trimester of pregnancy, All the infants were born by scheduled caesarean section in a tertiary care hospital and were the immediately referred to thew N.I.C.Us. Because of a mostly acute clinical presentation, the 4 patients were then referred to the surgical unit at different ages: 7 days, 28 days, 7 months, and 4 years respectively. The initial clinical presentation (Table II) was consistent with the site of the mass and/or its side effects. The 2 newborns (Case 1 and 2) both with a prenatally diagnosed mass located at the temporozygomatic region and in the abdominal cavite respectively, already displayed, at birth a mass with a tendency to further growth. The symptoms and signs described to the primary care physician by the parents of the 2

  6. Complete Sensitivity/Uncertainty Analysis of LR-0 Reactor Experiments with MSRE FLiBe Salt and Perform Comparison with Molten Salt Cooled and Molten Salt Fueled Reactor Models

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Nicholas R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Powers, Jeffrey J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Mueller, Don [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Patton, Bruce W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-12-01

    In September 2016, reactor physics measurements were conducted at Research Centre Rez (RC Rez) using the FLiBe (2 7LiF + BeF2) salt from the Molten Salt Reactor Experiment (MSRE) in the LR-0 low power nuclear reactor. These experiments were intended to inform on neutron spectral effects and nuclear data uncertainties for advanced reactor systems using FLiBe salt in a thermal neutron energy spectrum. Oak Ridge National Laboratory (ORNL), in collaboration with RC Rez, performed sensitivity/uncertainty (S/U) analyses of these experiments as part of the ongoing collaboration between the United States and the Czech Republic on civilian nuclear energy research and development. The objectives of these analyses were (1) to identify potential sources of bias in fluoride salt-cooled and salt-fueled reactor simulations resulting from cross section uncertainties, and (2) to produce the sensitivity of neutron multiplication to cross section data on an energy-dependent basis for specific nuclides. This report provides a final report on the S/U analyses of critical experiments at the LR-0 Reactor relevant to fluoride salt-cooled high temperature reactor (FHR) and liquid-fueled molten salt reactor (MSR) concepts. In the future, these S/U analyses could be used to inform the design of additional FLiBe-based experiments using the salt from MSRE. The key finding of this work is that, for both solid and liquid fueled fluoride salt reactors, radiative capture in 7Li is the most significant contributor to potential bias in neutronics calculations within the FLiBe salt.

  7. Dewatering of ashes from mixed fuels. Experiences and results from Tekniska Verken in Linkoeping; Avvattning av aska fraan blandbraenslen. Erfarenheter och resultat fraan Tekniska Verken i Linkoeping

    Energy Technology Data Exchange (ETDEWEB)

    Carlson, Ulf; Fredriksson, Anders; Lindahl, Inge [Tekniska Verken i Linkoeping AB (Sweden); Arevius, Anna; Sjoeblom, Rolf [AaF-Energikonsult AB, Stockholm (Sweden)

    2003-12-01

    Unit 3 at Tekniska Verken i Linkoeping (TVL) has a grid type furnace. During the firing season 2000 - 2001, the fuel has been comprising 45 % recovered wood chip, 45 % bark and 10 % recovered plastic material. The outfeed has been wet, and flyash and bottom ash have been mixed in the process. During 1999, about 19,000 tonnes of ash with a water content of about 50 % have been generated. The procedure has implied drawbacks in the form of handling of sludge and disposal of material with a high water content. The purpose of the work carried out has been to provide a basis for design of a handling in which these drawbacks have been eliminated, and which supports other destinations for the bottom ash than disposal. The search for information showed that a number of reactions, in particular hydratisation and recrystallisation, take place when ash is in contact with water. The process is strongly dependent on the chemical composition of the ash. The result is influenced not only by the chemical reactions that occur but also by the order in which they take place. Fly ash is very reactive while bottom ash is relatively inert. The experiments in the laboratory scale showed that bottom ash drained well while fly ash as well as different mixtures of fly ash and bottom ash are relatively impermeable to water. The ageing experiments which were carried out did not indicate any particular alteration in the permeability. Tests on a reduced scale clearly showed that bottom ash drains rapidly without the aid of vacuum and that the field capacity (the relative amount of water which does not drain) is low. Mixtures of bottom ash and fly ash drained more when vacuum was applied. However, such mixtures cured within a few hours and this lead to a substantial decrease in permeability. Tests on a pilot scale were conducted using three different methods of dewatering. The tests on self-percolation showed that most of the drainage water appeared during the first few hours where after the

  8. Experiences of stigma among people with severe mental illness. Reliability, acceptability and construct validity of the Swedish versions of two stigma scales measuring devaluation/discrimination and rejection experiences.

    Science.gov (United States)

    Björkman, Tommy; Svensson, Bengt; Lundberg, Bertil

    2007-01-01

    Stigma has been identified as one of the most important obstacles for a successful integration of people with mental illness into the society. Research about stigma has shown negative attitudes among the public towards people with mental illness. Studies so far have, however, put little emphasis on how these negative attitudes are perceived by the mentally ill persons. The aim of the present study was to investigate acceptability and internal consistency of the Swedish versions of two stigma scales, the Devaluation and Discrimination scale and the Rejection experiences scale. Forty individuals were subject to an interview, which also comprised assessments of needs for care, quality of life, therapeutic relationship and empowerment. The results showed that both the Devaluation and Discrimination scale and the Rejection experiences scale had a good internal consistency and acceptability. Stigma in terms of perceived devaluation and discrimination was found to be most markedly associated with empowerment and rejection experiences was found to be most associated with the number of previous psychiatric admissions. It is concluded that the Swedish versions of the Devaluation and Discrimination scale and the Rejection experiences scale may well be used in further studies of stigma among people with mental illness.

  9. Reliability and Availability of Cloud Computing

    CERN Document Server

    Bauer, Eric

    2012-01-01

    A holistic approach to service reliability and availability of cloud computing Reliability and Availability of Cloud Computing provides IS/IT system and solution architects, developers, and engineers with the knowledge needed to assess the impact of virtualization and cloud computing on service reliability and availability. It reveals how to select the most appropriate design for reliability diligence to assure that user expectations are met. Organized in three parts (basics, risk analysis, and recommendations), this resource is accessible to readers of diverse backgrounds and experience le

  10. Bringing fuel cells to reality and reality to fuel cells: A systems perspective on the use of fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Saxe, Maria

    2008-10-15

    The hopes and expectations on fuel cells are high and sometimes unrealistically positive. However, as an emerging technology, much remains to be proven and the proper use of the technology in terms of suitable applications, integration with society and extent of use is still under debate. This thesis is a contribution to the debate, presenting results from two fuel cell demonstration projects, looking into the introduction of fuel cells on the market, discussing the prospects and concerns for the near-term future and commenting on the potential use in a future sustainable energy system. Bringing fuel cells to reality implies finding near-term niche applications and markets where fuel cell systems may be competitive. In a sense fuel cells are already a reality as they have been demonstrated in various applications world-wide. However, in many of the envisioned applications fuel cells are far from being competitive and sometimes also the environmental benefit of using fuel cells in a given application may be questioned. Bringing reality to fuel cells implies emphasising the need for realistic expectations and pointing out that the first markets have to be based on the currently available technology and not the visions of what fuel cells could be in the future. The results from the demonstration projects show that further development and research on especially the durability for fuel cell systems is crucial and a general recommendation is to design the systems for high reliability and durability rather than striving towards higher energy efficiencies. When sufficient reliability and durability are achieved, fuel cell systems may be introduced in niche markets where the added values presented by the technology compensate for the initial high cost

  11. Operating Experiences with a Small-scale CHP Pilot Plant based on a 35 kWel Hermetic Four Cylinder Stirling Engine for Biomass Fuels

    DEFF Research Database (Denmark)

    Biedermann, F.; Carlsen, Henrik; Schoech, M.

    2003-01-01

    Within the scope of the RD&D project presented a small-scale CHP plant with a hermetic four cylinder Stirling engine for biomass fuels was developed and optimised in cooperation with the Technical University of Denmark, MAWERA Holzfeuerungsanlagen GesmbH, an Austrian biomass furnace and boiler...

  12. Problems of renewal of the main resources and experience in ecological improvement of coal fuels at TPS of 'OAO Sverdlovenergo'

    Energy Technology Data Exchange (ETDEWEB)

    Korelkin, G.; Knyazev, A.

    2003-07-01

    From 1990 up to now, the rate of renewal of the main power generating capacities in Russia as well as in the Ural region decreased considerably. Accordingly, the problems of physical depreciation and obsolescence of equipment installed at TPS, heating and electric networks have become acute during the past few years. This resulted in deterioration of boiler performance and gradual reduction of general effectiveness of power generating facilities. Sverdlovskenergo faces the problems too. Over the past 15 years intense convection transfer surfaces (ribbed, membrane-, band-spiral and combined type) were introduced at 17 boilers. This retrofit gave fuel saving up to 3000 t of conventional fuel annually per one boiler. A wide range of works is being executed to ensure ecological safety of combustion processes. Twenty one boilers of IE-14 type at Serovskaya and Verkhnetagilskaya TPS, equipped with coal handling systems with direct blow , simplified two- and three-stage solid fuel combustion schemes were introduced. Staged combustion of ekibastuz coal was realized via the formation of oxygen-deficient and oxygen-excess zones by pulverized coal redistribution between the burners. Centrifugal coal powder distributor directing air/fuel mixture to two burners located in two rows was designed. 5 figs.

  13. HTGR Generic Technology Program. Materials technology reactor operating experience medium-enriched-uranium fuel development. Quarterly progress report for the period ending April 30, 1978

    Energy Technology Data Exchange (ETDEWEB)

    Kaae, J. L.; Lai, G. Y.; Thompson, L. D.; Sheehan, J. E.; Rosenwasser, S. N.; Johnson, W. R.; Li, C. C.; Pieren, W. R.; Smith, A. B.; Holko, K. H.; Baenteli, G. J.; Cheung, K. C.; Orr, J. D.; Potter, R. C.; Baxter, A.; Bell, W.; Lane, R.; Wunderlich, R. G.; Neylan, A. J.

    1978-05-01

    The work reported includes the development of the materials properties data base for noncore components, plant surveillance and testing performed at Fort St. Vrain, and work to demonstrate the feasibility of using medium-enriched fuel in Fort St. Vrain. Studies and analyses plus experimental procedures and results are discussed and data are presented.

  14. HTGR Generic Technology Program: materials technology reactor; operating experience; medium-enriched-uranium fuel development. Quarterly progress report for the period ending July 31, 1978

    Energy Technology Data Exchange (ETDEWEB)

    1978-08-01

    The work reported includes the development of the materials properties data base for noncore components, plant surveillance and testing performed at Fort St. Vrain, and work to demonstrate the feasibility of using medium-enriched fuel in Fort St. Vrain. Studies and analyses plus experimental procedures and results are discussed and data are presented.

  15. Reliability and safety engineering

    CERN Document Server

    Verma, Ajit Kumar; Karanki, Durga Rao

    2016-01-01

    Reliability and safety are core issues that must be addressed throughout the life cycle of engineering systems. Reliability and Safety Engineering presents an overview of the basic concepts, together with simple and practical illustrations. The authors present reliability terminology in various engineering fields, viz.,electronics engineering, software engineering, mechanical engineering, structural engineering and power systems engineering. The book describes the latest applications in the area of probabilistic safety assessment, such as technical specification optimization, risk monitoring and risk informed in-service inspection. Reliability and safety studies must, inevitably, deal with uncertainty, so the book includes uncertainty propagation methods: Monte Carlo simulation, fuzzy arithmetic, Dempster-Shafer theory and probability bounds. Reliability and Safety Engineering also highlights advances in system reliability and safety assessment including dynamic system modeling and uncertainty management. Cas...

  16. PV system field experience and reliability

    Science.gov (United States)

    Durand, Steven; Rosenthal, Andrew; Thomas, Mike

    1997-02-01

    Hybrid power systems consisting of battery inverters coupled with diesel, propane, or gasoline engine-driven electrical generators, and photovoltaic arrays are being used in many remote locations. The potential cost advantages of hybrid systems over simple engine-driven generator systems are causing hybrid systems to be considered for numerous applications including single-family residential, communications, and village power. This paper discusses the various design constraints of such systems and presents one technique for reducing hybrid system losses. The Southwest Technology Development Institute under contract to the National Renewable Energy Laboratory and Sandia National Laboratories has been installing data acquisition systems (DAS) on a number of small and large hybrid PV systems. These systems range from small residential systems (1 kW PV - 7 kW generator), to medium sized systems (10 kW PV - 20 kW generator), to larger systems (100 kW PV - 200 kW generator). Even larger systems are being installed with hundreds of kilowatts of PV modules, multiple wind machines, and larger diesel generators.

  17. Application of the BISON Fuel Performance Code to the FUMEX-III Coordinated Research Project

    Energy Technology Data Exchange (ETDEWEB)

    R. L. Williamson; S. R. Novascone

    2012-04-01

    INL recently participated in FUMEX-III, an International Atomic Energy Agency sponsored fuel modeling Coordinated Research Project. A main purpose of FUMEX-III is to compare code predictions to reliable experimental data. During the same time period, the INL initiated development of a new multidimensional (2D and 3D) multiphysics nuclear fuel performance code called BISON. Interactions with international fuel modeling researchers via FUMEX-III played a significant and important role in the BISON evolution, particularly influencing the selection of material and behavioral models which are now included in the code. BISON's ability to model integral fuel rod behavior did not mature until 2011, thus the only FUMEX-III case considered was the Riso3-GE7 experiment, which includes measurements of rod outer diameter following pellet clad mechanical interaction (PCMI) resulting from a power ramp late in fuel life. BISON comparisons to the Riso3-GE7 final rod diameter measurements are quite reasonable. The INL is very interested in participation in the next Fuel Modeling Coordinated Research Project and would like to see the project initiated as soon as possible.

  18. Solar fuels

    Energy Technology Data Exchange (ETDEWEB)

    Bolton, J.R.

    1978-11-17

    The paper is concerned with (1) the thermodynamic and kinetic limits for the photochemical conversion and storage of solar energy as it is received on the earth's surface, and (2) the evaluation of a number of possible photochemical reactions with particular emphasis on the production of solar hydrogen from water. Procedures for generating hydrogen fuel are considered. Topics examined include the general requirements for a fuel-generation reaction, the photochemical reaction, limits on the conversion of light energy to chemical energy, an estimate of chemical storage efficiency, and the water decomposition reaction.

  19. Análisis de confiabilidad y de validez del instrumento Course Experience Questionnaire (CEQ Análise de confiabilidade e de validade do instrumento Course Experience Questionnaire (CEQ Analysis of the Reliability and Validity of the Course Experience Questionnaire (CEQ

    Directory of Open Access Journals (Sweden)

    Carlos González

    2012-04-01

    into Spanish and applied to 325 engineering students at a public university in a metropolitan area of Chile. Descriptive statistics were compiled and the analysis of both reliability and validity showed mostly adequate results. The CEQ can be applied to measure the quality of teaching at Latin American universities and the suggestion is that it be used for research purposes. New studies should continue to validate this tool and to include other variables regarded as crucial in "student learning research" to investigate the learning experience of college students.

  20. Measurement System Reliability Assessment

    Directory of Open Access Journals (Sweden)

    Kłos Ryszard

    2015-06-01

    Full Text Available Decision-making in problem situations is based on up-to-date and reliable information. A great deal of information is subject to rapid changes, hence it may be outdated or manipulated and enforce erroneous decisions. It is crucial to have the possibility to assess the obtained information. In order to ensure its reliability it is best to obtain it with an own measurement process. In such a case, conducting assessment of measurement system reliability seems to be crucial. The article describes general approach to assessing reliability of measurement systems.

  1. Reliable knowledge discovery

    CERN Document Server

    Dai, Honghua; Smirnov, Evgueni

    2012-01-01

    Reliable Knowledge Discovery focuses on theory, methods, and techniques for RKDD, a new sub-field of KDD. It studies the theory and methods to assure the reliability and trustworthiness of discovered knowledge and to maintain the stability and consistency of knowledge discovery processes. RKDD has a broad spectrum of applications, especially in critical domains like medicine, finance, and military. Reliable Knowledge Discovery also presents methods and techniques for designing robust knowledge-discovery processes. Approaches to assessing the reliability of the discovered knowledge are introduc

  2. Reliability of fluid systems

    Directory of Open Access Journals (Sweden)

    Kopáček Jaroslav

    2016-01-01

    Full Text Available This paper focuses on the importance of detection reliability, especially in complex fluid systems for demanding production technology. The initial criterion for assessing the reliability is the failure of object (element, which is seen as a random variable and their data (values can be processed using by the mathematical methods of theory probability and statistics. They are defined the basic indicators of reliability and their applications in calculations of serial, parallel and backed-up systems. For illustration, there are calculation examples of indicators of reliability for various elements of the system and for the selected pneumatic circuit.

  3. Circuit design for reliability

    CERN Document Server

    Cao, Yu; Wirth, Gilson

    2015-01-01

    This book presents physical understanding, modeling and simulation, on-chip characterization, layout solutions, and design techniques that are effective to enhance the reliability of various circuit units.  The authors provide readers with techniques for state of the art and future technologies, ranging from technology modeling, fault detection and analysis, circuit hardening, and reliability management. Provides comprehensive review on various reliability mechanisms at sub-45nm nodes; Describes practical modeling and characterization techniques for reliability; Includes thorough presentation of robust design techniques for major VLSI design units; Promotes physical understanding with first-principle simulations.

  4. Experimental fuel rod stored energy determination. STEED I project

    Energy Technology Data Exchange (ETDEWEB)

    Engman, U.; Malen, K. [Studsvik Nuclear AB, Nykoeping (Sweden)

    1999-06-01

    The objective of the STEED I (STored Energy/Enthalpy Determination) project was to evaluate an experimental method for producing accurate and reliable data concerning the stored energy in fuel rods during operation. The STEED data should provide useful information for LOCA evaluation, fuel design and thermo-mechanical modelling. Stored energy refers to the amount of heat, which at a certain time is stored within the fuel. Physical properties of the fuel that affect the quantity of stored energy are radial power profile, burnup, fuel geometry, fuel density and thermal conductivity and heat capacity of the fuel pellet, and the gas gap conductance. The quantity of stored energy is conveniently studied under transient conditions when all, or part of the stored heat is released. This work describes determination of the stored energy by evaluating scram tests. The R2 test reactor is well suited for this type of experiments, where the thermal response of different types of fuel rods can be evaluated and compared. Scrams have been performed with the intent to evaluate the fuel rod stored energy before the scram. Methods have been developed for evaluation of the stored energy from the scram response It was found that the time dependence for a large part of the heat release from the rod could be described by a single time constant. Evaluations of the time constant have been made from the data in different ways. The stored energy has been evaluated integrating the exponential decay. The integral of the exponential decay is the initial power multiplied by the time constant. This means that differences in the stored energy due to, for instance, rod properties or rod power dependence are best studied using the same time constant. The scram response was modelled with the TOODEE2 transient code. The calculations gave a time constant of about 4 s and very little power dependence. The experimental result is a time constant around 4 s. The small differences in the measurement results

  5. Quivers For Special Fuel Rods-Disposal Of Special Fuel Rods In CASTOR V Casks

    Energy Technology Data Exchange (ETDEWEB)

    Bannani, Amin; Cebula, Wojciech; Buchmuller, Olga; Huggenberg, Roland [GNS, Essen (Germany); Helmut Kuhl [WTI, Julich (Germany)

    2015-05-15

    While GNS casks of the CASTOR family are a suitable means to transfer fuel assemblies (FA) from the NPP to an interim dry storage site, Germanys phase-out of nuclear energy has triggered the demand for an additional solution to dispose of special fuel rods (SFR), normally remaining in the fuel pond until the final shutdown of the NPP. SFR are fuel rods that had to be removed from fuel assemblies mainly due to their special condition, e. g. damages in the cladding of the fuel rods which may have occurred during reactor operations. SFR are usually stored in the spent fuel pond after they are removed from the FA. The quiver for special fuel rods features a robust yet simple design, with a high mechanical stability, a reliable leak-tightness and large safety margins for future requirements on safety analysis. The quiver for special fuel rods can be easily adapted to a large variety of different damaged fuel rods and tailored to the specific need of the customer. The quiver for special fuel rods is adaptable e.g. in length and diameter for use in other types of transport and storage casks and is applicable in other countries as well. The overall concept presented here is a first of its kind solution for the disposal of SFRs via Castor V-casks. This provides an important precondition in achieving the status 'free from nuclear fuel' of the shut down German NPPs.

  6. The Fuel Handbook 2012; Braenslehandboken 2012

    Energy Technology Data Exchange (ETDEWEB)

    Stroemberg, Birgitta; Herstad Svaerd, Solvie

    2012-04-15

    This fuel handbook provides, from a plant owner's perspective, a method of evaluating different fuels on the market. The fuel handbook concerns renewable fuels (but not including household waste) that are available on the Swedish market today or which are judged to have the potential to be available within the next ten years. The handbook covers 31 different fuels. Analysis data, special properties, operating experience, recommendations, risks when using the fuels and literature references are outlined for each fuel. The handbook also contains 1. A proposed route to follow when one plans to introduce a new fuel. Those analyses and tests one should perform to reduce the risk of encountering problems. 2. A summary of relevant laws and taxes for energy production, with directions as to where relevant documentation can be found. 3. Theory and background to judge the fuel's combustion, ash and corrosion properties and different methods that can be used for such judgement. 4. Summary of standards, databases and handbooks for biomass fuels and other solid fuels, and details on where further information on the fuels can be found, with the help of links to different web sites. Included in the annexes are 1. A proposal for a standard procedure for test burning of fuel. 2. Calculations procedures for, amongst others, heating value, flue gas composition and key numbers. In addition, calculations routines for different units for a number of different applications are provided

  7. Sustainable Hypersaline Microbial Fuel Cells: Inexpensive Recyclable Polymer Supports for Carbon Nanotube Conductive Paint Anodes.

    Science.gov (United States)

    Grattieri, Matteo; Shivel, Nelson D; Sifat, Iram; Bestetti, Massimiliano; Minteer, Shelley D

    2017-02-28

    Microbial fuel cells are an emerging technology for wastewater treatment, but to be commercially viable and sustainable, the electrode materials must be inexpensive, recyclable, and reliable. In this study, recyclable polymeric supports were explored for the development of anode electrodes to be applied in single-chamber microbial fuel cells operated in field under hypersaline conditions. The support was covered with a carbon nanotube (CNT) based conductive paint, and biofilms were able to colonize the electrodes. The single-chamber microbial fuel cells with Pt-free cathodes delivered a reproducible power output after 15 days of operation to achieve 12±1 mW m(-2) at a current density of 69±7 mA m(-2) . The decrease of the performance in long-term experiments was mostly related to inorganic precipitates on the cathode electrode and did not affect the performance of the anode, as shown by experiments in which the cathode was replaced and the fuel cell performance was regenerated. The results of these studies show the feasibility of polymeric supports coated with CNT-based paint for microbial fuel cell applications.

  8. Dynamic modeling, experimental evaluation, optimal design and control of integrated fuel cell system and hybrid energy systems for building demands

    Science.gov (United States)

    Nguyen, Gia Luong Huu

    Fuel cells can produce electricity with high efficiency, low pollutants, and low noise. With the advent of fuel cell technologies, fuel cell systems have since been demonstrated as reliable power generators with power outputs from a few watts to a few megawatts. With proper equipment, fuel cell systems can produce heating and cooling, thus increased its overall efficiency. To increase the acceptance from electrical utilities and building owners, fuel cell systems must operate more dynamically and integrate well with renewable energy resources. This research studies the dynamic performance of fuel cells and the integration of fuel cells with other equipment in three levels: (i) the fuel cell stack operating on hydrogen and reformate gases, (ii) the fuel cell system consisting of a fuel reformer, a fuel cell stack, and a heat recovery unit, and (iii) the hybrid energy system consisting of photovoltaic panels, fuel cell system, and energy storage. In the first part, this research studied the steady-state and dynamic performance of a high temperature PEM fuel cell stack. Collaborators at Aalborg University (Aalborg, Denmark) conducted experiments on a high temperature PEM fuel cell short stack at steady-state and transients. Along with the experimental activities, this research developed a first-principles dynamic model of a fuel cell stack. The dynamic model developed in this research was compared to the experimental results when operating on different reformate concentrations. Finally, the dynamic performance of the fuel cell stack for a rapid increase and rapid decrease in power was evaluated. The dynamic model well predicted the performance of the well-performing cells in the experimental fuel cell stack. The second part of the research studied the dynamic response of a high temperature PEM fuel cell system consisting of a fuel reformer, a fuel cell stack, and a heat recovery unit with high thermal integration. After verifying the model performance with the

  9. Transport fuel

    DEFF Research Database (Denmark)

    Ronsse, Frederik; Jørgensen, Henning; Schüßler, Ingmar

    2014-01-01

    Worldwide, the use of transport fuel derived from biomass increased four-fold between 2003 and 2012. Mainly based on food resources, these conventional biofuels did not achieve the expected emission savings and contributed to higher prices for food commod - ities, especially maize and oilseeds...

  10. LED system reliability

    NARCIS (Netherlands)

    Driel, W.D. van; Yuan, C.A.; Koh, S.; Zhang, G.Q.

    2011-01-01

    This paper presents our effort to predict the system reliability of Solid State Lighting (SSL) applications. A SSL system is composed of a LED engine with micro-electronic driver(s) that supplies power to the optic design. Knowledge of system level reliability is not only a challenging scientific ex

  11. Principles of Bridge Reliability

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle; Nowak, Andrzej S.

    The paper gives a brief introduction to the basic principles of structural reliability theory and its application to bridge engineering. Fundamental concepts like failure probability and reliability index are introduced. Ultimate as well as serviceability limit states for bridges are formulated...

  12. Improving machinery reliability

    CERN Document Server

    Bloch, Heinz P

    1998-01-01

    This totally revised, updated and expanded edition provides proven techniques and procedures that extend machinery life, reduce maintenance costs, and achieve optimum machinery reliability. This essential text clearly describes the reliability improvement and failure avoidance steps practiced by best-of-class process plants in the U.S. and Europe.

  13. Hawaii Electric System Reliability

    Energy Technology Data Exchange (ETDEWEB)

    Loose, Verne William [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Silva Monroy, Cesar Augusto [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2012-08-01

    This report addresses Hawaii electric system reliability issues; greater emphasis is placed on short-term reliability but resource adequacy is reviewed in reference to electric consumers’ views of reliability “worth” and the reserve capacity required to deliver that value. The report begins with a description of the Hawaii electric system to the extent permitted by publicly available data. Electrical engineering literature in the area of electric reliability is researched and briefly reviewed. North American Electric Reliability Corporation standards and measures for generation and transmission are reviewed and identified as to their appropriateness for various portions of the electric grid and for application in Hawaii. Analysis of frequency data supplied by the State of Hawaii Public Utilities Commission is presented together with comparison and contrast of performance of each of the systems for two years, 2010 and 2011. Literature tracing the development of reliability economics is reviewed and referenced. A method is explained for integrating system cost with outage cost to determine the optimal resource adequacy given customers’ views of the value contributed by reliable electric supply. The report concludes with findings and recommendations for reliability in the State of Hawaii.

  14. Hawaii electric system reliability.

    Energy Technology Data Exchange (ETDEWEB)

    Silva Monroy, Cesar Augusto; Loose, Verne William

    2012-09-01

    This report addresses Hawaii electric system reliability issues; greater emphasis is placed on short-term reliability but resource adequacy is reviewed in reference to electric consumers' views of reliability %E2%80%9Cworth%E2%80%9D and the reserve capacity required to deliver that value. The report begins with a description of the Hawaii electric system to the extent permitted by publicly available data. Electrical engineering literature in the area of electric reliability is researched and briefly reviewed. North American Electric Reliability Corporation standards and measures for generation and transmission are reviewed and identified as to their appropriateness for various portions of the electric grid and for application in Hawaii. Analysis of frequency data supplied by the State of Hawaii Public Utilities Commission is presented together with comparison and contrast of performance of each of the systems for two years, 2010 and 2011. Literature tracing the development of reliability economics is reviewed and referenced. A method is explained for integrating system cost with outage cost to determine the optimal resource adequacy given customers' views of the value contributed by reliable electric supply. The report concludes with findings and recommendations for reliability in the State of Hawaii.

  15. Photovoltaic performance and reliability workshop

    Energy Technology Data Exchange (ETDEWEB)

    Kroposki, B

    1996-10-01

    This proceedings is the compilation of papers presented at the ninth PV Performance and Reliability Workshop held at the Sheraton Denver West Hotel on September 4--6, 1996. This years workshop included presentations from 25 speakers and had over 100 attendees. All of the presentations that were given are included in this proceedings. Topics of the papers included: defining service lifetime and developing models for PV module lifetime; examining and determining failure and degradation mechanisms in PV modules; combining IEEE/IEC/UL testing procedures; AC module performance and reliability testing; inverter reliability/qualification testing; standardization of utility interconnect requirements for PV systems; need activities to separate variables by testing individual components of PV systems (e.g. cells, modules, batteries, inverters,charge controllers) for individual reliability and then test them in actual system configurations; more results reported from field experience on modules, inverters, batteries, and charge controllers from field deployed PV systems; and system certification and standardized testing for stand-alone and grid-tied systems.

  16. Chapter 9: Reliability

    Energy Technology Data Exchange (ETDEWEB)

    Algora, Carlos; Espinet-Gonzalez, Pilar; Vazquez, Manuel; Bosco, Nick; Miller, David; Kurtz, Sarah; Rubio, Francisca; McConnell,Robert

    2016-04-15

    This chapter describes the accumulated knowledge on CPV reliability with its fundamentals and qualification. It explains the reliability of solar cells, modules (including optics) and plants. The chapter discusses the statistical distributions, namely exponential, normal and Weibull. The reliability of solar cells includes: namely the issues in accelerated aging tests in CPV solar cells, types of failure and failures in real time operation. The chapter explores the accelerated life tests, namely qualitative life tests (mainly HALT) and quantitative accelerated life tests (QALT). It examines other well proven and experienced PV cells and/or semiconductor devices, which share similar semiconductor materials, manufacturing techniques or operating conditions, namely, III-V space solar cells and light emitting diodes (LEDs). It addresses each of the identified reliability issues and presents the current state of the art knowledge for their testing and evaluation. Finally, the chapter summarizes the CPV qualification and reliability standards.

  17. Premixing of corium into water during a Fuel-Coolant Interaction. The models used in the 3 field version of the MC3D code and two examples of validation on Billeau and FARO experiments

    Energy Technology Data Exchange (ETDEWEB)

    Berthoud, G.; Crecy, F. de; Duplat, F.; Meignen, R.; Valette, M. [CEA/Grenoble, DRN/DTP, 17 Avenue des Martyrs, 38054 Grenoble Cedex 9 (France)

    1998-01-01

    This paper presents the <> application of the multiphasic 3D computer code MC3D. This application is devoted to the premixing phase of a Fuel Coolant Interaction (FCI) when large amounts of molten corium flow into water and interact with it. A description of the new features of the model is given (a more complete description of the full model is given in annex). Calculations of Billeau experiments (cold or hot spheres dropped into water) and of a FARO test (<> corium dropped into 5 MPa saturated water) are presented. (author)

  18. A GUIDE TO FUEL PERFORMANCE

    Energy Technology Data Exchange (ETDEWEB)

    LITZKE,W.

    2004-08-01

    Heating oil, as its name implies, is intended for end use heating consumption as its primary application. But its identity in reference name and actual chemical properties may vary based on a number of factors. By name, heating oil is sometimes referred to as gas oil, diesel, No. 2 distillate (middle distillate), or light heating oil. Kerosene, also used as a burner fuel, is a No. 1 distillate. Due to the higher heat content and competitive price in most markets, No. 2 heating oil is primarily used in modern, pressure-atomized burners. Using No. 1 oil for heating has the advantages of better cold-flow properties, lower emissions, and better storage properties. Because it is not nearly as abundant in supply, it is often markedly more expensive than No. 2 heating oil. Given the advanced, low-firing rate burners in use today, the objective is for the fuel to be compatible and achieve combustion performance at the highest achievable efficiency of the heating systems--with minimal service requirements. Among the Oil heat industry's top priorities are improving reliability and reducing service costs associated with fuel performance. Poor fuel quality, fuel degradation, and contamination can cause burner shut-downs resulting in ''no-heat'' calls. Many of these unscheduled service calls are preventable with routine inspection of the fuel and the tank. This manual focuses on No. 2 heating oil--its performance, properties, sampling and testing. Its purpose is to provide the marketer, service manager and technician with the proper guidelines for inspecting the product, maintaining good fuel quality, and the best practices for proper storage. Up-to-date information is also provided on commercially available fuel additives, their appropriate use and limitations.

  19. Wind-To-Hydrogen Project: Operational Experience, Performance Testing, and Systems Integration

    Energy Technology Data Exchange (ETDEWEB)

    Harrison, K. W.; Martin, G. D.; Ramsden, T. G.; Kramer, W. E.; Novachek, F. J.

    2009-03-01

    The Wind2H2 system is fully functional and continues to gather performance data. In this report, specifications of the Wind2H2 equipment (electrolyzers, compressor, hydrogen storage tanks, and the hydrogen fueled generator) are summarized. System operational experience and lessons learned are discussed. Valuable operational experience is shared through running, testing, daily operations, and troubleshooting the Wind2H2 system and equipment errors are being logged to help evaluate the reliability of the system.

  20. Next Generation Reliable Transport Networks

    DEFF Research Database (Denmark)

    Zhang, Jiang

    of criticality and security, there are certain physical or logical segregation requirements between the avionic systems. Such segregations can be implemented on the proposed avionic networks with different hierarchies. In order to fulfill the segregation requirements, a tailored heuristic approach for solving......This thesis focuses the efforts on ensuring the reliability of transport networks and takes advantages and experiences from the transport networks into the networks for particular purposes. Firstly, the challenges of providing reliable multicast services on Multipath Label Switching......-Transport Profile (MPLS-TP) ring networks are addressed. Through the proposed protection structure and protection switching schemes, the recovery mechanism is enhanced in terms of recovery label consumption, operation simplicity and fine traffic engineering granularity. Furthermore, the extensions for existing...

  1. Power Quality and Reliability Project

    Science.gov (United States)

    Attia, John O.

    2001-01-01

    One area where universities and industry can link is in the area of power systems reliability and quality - key concepts in the commercial, industrial and public sector engineering environments. Prairie View A&M University (PVAMU) has established a collaborative relationship with the University of'Texas at Arlington (UTA), NASA/Johnson Space Center (JSC), and EP&C Engineering and Technology Group (EP&C) a small disadvantage business that specializes in power quality and engineering services. The primary goal of this collaboration is to facilitate the development and implementation of a Strategic Integrated power/Systems Reliability and Curriculum Enhancement Program. The objectives of first phase of this work are: (a) to develop a course in power quality and reliability, (b) to use the campus of Prairie View A&M University as a laboratory for the study of systems reliability and quality issues, (c) to provide students with NASA/EPC shadowing and Internship experience. In this work, a course, titled "Reliability Analysis of Electrical Facilities" was developed and taught for two semesters. About thirty seven has benefited directly from this course. A laboratory accompanying the course was also developed. Four facilities at Prairie View A&M University were surveyed. Some tests that were performed are (i) earth-ground testing, (ii) voltage, amperage and harmonics of various panels in the buildings, (iii) checking the wire sizes to see if they were the right size for the load that they were carrying, (iv) vibration tests to test the status of the engines or chillers and water pumps, (v) infrared testing to the test arcing or misfiring of electrical or mechanical systems.

  2. Metal Fuel Development and Verification for Prototype Generation IV Sodium-Cooled Fast Reactor

    OpenAIRE

    Chan Bock Lee; Jin Sik Cheon; Sung Ho Kim; Jeong-Yong Park; Hyung-Kook Joo

    2016-01-01

    Metal fuel is being developed for the prototype generation-IV sodium-cooled fast reactor (PGSFR) to be built by 2028. U–Zr fuel is a driver for the initial core of the PGSFR, and U–transuranics (TRU)–Zr fuel will gradually replace U–Zr fuel through its qualification in the PGSFR. Based on the vast worldwide experiences of U–Zr fuel, work on U–Zr fuel is focused on fuel design, fabrication of fuel components, and fuel verification tests. U–TRU–Zr fuel uses TRU recovered through pyroelectrochem...

  3. Photovoltaic system reliability

    Energy Technology Data Exchange (ETDEWEB)

    Maish, A.B.; Atcitty, C. [Sandia National Labs., NM (United States); Greenberg, D. [Ascension Technology, Inc., Lincoln Center, MA (United States)] [and others

    1997-10-01

    This paper discusses the reliability of several photovoltaic projects including SMUD`s PV Pioneer project, various projects monitored by Ascension Technology, and the Colorado Parks project. System times-to-failure range from 1 to 16 years, and maintenance costs range from 1 to 16 cents per kilowatt-hour. Factors contributing to the reliability of these systems are discussed, and practices are recommended that can be applied to future projects. This paper also discusses the methodology used to collect and analyze PV system reliability data.

  4. Structural Reliability Methods

    DEFF Research Database (Denmark)

    Ditlevsen, Ove Dalager; Madsen, H. O.

    of structural reliability, including the theoretical basis for these methods. Partial safety factor codes under current practice are briefly introduced and discussed. A probabilistic code format for obtaining a formal reliability evaluation system that catches the most essential features of the nature......The structural reliability methods quantitatively treat the uncertainty of predicting the behaviour and properties of a structure given the uncertain properties of its geometry, materials, and the actions it is supposed to withstand. This book addresses the probabilistic methods for evaluation...

  5. Post-test calculation of the QUENCH-17 bundle experiment with debris formation and bottom water reflood using thermal hydraulic and severe fuel damage code SOCRAT/V3

    Energy Technology Data Exchange (ETDEWEB)

    Vasiliev, A., E-mail: vasil@ibrae.ac.ru [Nuclear Safety Institute (IBRAE), B. Tulskaya 52, 115191 Moscow (Russian Federation); Stuckert, J., E-mail: juri.stuckert@kit.edu [Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany)

    2015-03-15

    Highlights: • Modeling of processes in porous debris regions. • Analysis of coolability of massive debris bed. • Complexity of simulation of flow regime near boiling curve. - Abstract: The thermal hydraulic and SFD (Severe Fuel Damage) best estimate computer modeling code SOCRAT/V3 was used for the post-test analysis of the QUENCH-17 experiment performed at KIT on January 2013. The objective of this test was to examine the formation of a debris bed inside the completely oxidized region of the bundle without melt formation and to investigate the coolability behavior during the reflood. The test bundle for QUENCH-17 test was intentionally changed in comparison to basic QUENCH bundles (usually 21 heated rod simulators) with the emphasis to investigate debris behavior phenomena. Only 12 periphery fuel rod simulators were heated by centerline tungsten heaters. 9 unheated fuel rod simulators were located in the inner part of the test bundle. This is why the massive porous debris formation in the inner part of the bundle was not influenced by the presence of tungsten heaters. The QUENCH-17 test conditions simulated a hypothetical scenario of nuclear power plant severe accident sequence with debris bed formation in which the overheated up to 1800 K core would be flooded from the bottom by ECCS (Emergency Core Cooling System). The QUENCH-17 test included the following phases: (1) heat-up phase (heat-up rate up to 0.25 K/s); (2) oxidation phase (the cladding temperature about 1800 K in hottest region, steam mass flow rate 2 g/s); (3) bottom flood phase (characteristic cooling time about 600 s, water mass flow rate 10 g/s). SOCRAT/V3 computer modeling code was used for calculation of basic thermal hydraulic, oxidation and thermal mechanical behavior during all phases of the experiment. The calculated results are in a good agreement with experimental data which justifies the adequacy of modeling capabilities of SOCRAT code system.

  6. Fuel control system for dual fuel engines

    Energy Technology Data Exchange (ETDEWEB)

    Helmich, M.J.; Ryan, W.P.; Marvin, D.H.

    1987-11-24

    A fuel governing system for an engine adapted for operation on a first fuel and a second fuel is described comprising: a first fuel governing system including a spontaneous motion metering means; and a second fuel governing system, the second fuel governing system further comprising: means for providing a first signal indicative of position of the first fuel metering means, which signal approximates total load on the engine, means for providing a second signal of the selected percentage of first fuel relative to total load, means for controlling flow of the second fuel to the engine, which flow causes reflective displacement of the first fuel metering means, means for determining the difference between the first signal and the second signal, which difference is indicative of distance the first fuel metering means must be moved to attain the selected percentage of first fuel relative to total load, and means for causing operation of the means for controlling flow of the second fuel to the engine to cause displacement of the first fuel metering means equal to the distance the first fuel metering means must be moved to attain the selected percentage of first fuel relative to total load.

  7. High Temperature PEM Fuel Cell Systems, Control and Diagnostics

    DEFF Research Database (Denmark)

    Andreasen, Søren Juhl; Kær, Søren Knudsen; Justesen, Kristian Kjær

    2015-01-01

    Various system topologies are available when it comes to designing high temperature PEM fuel cell systems. Very simple system designs are possible using pure hydrogen, and more complex system designs present themselves when alternative fuels are desired, using reformer systems. The use of reformed...... fuels utilizes one of the main advantages of the high temperature PEM fuel cell: robustness to fuel quality and impurities. In order for such systems to provide efficient, robust, and reliable energy, proper control strategies are needed. The complexity and nonlinearity of many of the components...

  8. Fuel model selection for BEHAVE in midwestern oak savannas

    Science.gov (United States)

    Grabner, K.W.; Dwyer, J.P.; Cutter, B.E.

    2001-01-01

    BEHAVE, a fire behavior prediction system, can be a useful tool for managing areas with prescribed fire. However, the proper choice of fuel models can be critical in developing management scenarios. BEHAVE predictions were evaluated using four standardized fuel models that partially described oak savanna fuel conditions: Fuel Model 1 (Short Grass), 2 (Timber and Grass), 3 (Tall Grass), and 9 (Hardwood Litter). Although all four models yielded regressions with R2 in excess of 0.8, Fuel Model 2 produced the most reliable fire behavior predictions.

  9. Reliable Electronic Equipment

    Directory of Open Access Journals (Sweden)

    N. A. Nayak

    1960-05-01

    Full Text Available The reliability aspect of electronic equipment's is discussed. To obtain optimum results, close cooperation between the components engineer, the design engineer and the production engineer is suggested.

  10. Reliability prediction techniques

    Energy Technology Data Exchange (ETDEWEB)

    Whittaker, B.; Worthington, B.; Lord, J.F.; Pinkard, D.

    1986-01-01

    The paper demonstrates the feasibility of applying reliability assessment techniques to mining equipment. A number of techniques are identified and described and examples of their use in assessing mining equipment are given. These techniques include: reliability prediction; failure analysis; design audit; maintainability; availability and the life cycle costing. Specific conclusions regarding the usefulness of each technique are outlined. The choice of techniques depends upon both the type of equipment being assessed and its stage of development, with numerical prediction best suited for electronic equipment and fault analysis and design audit suited to mechanical equipment. Reliability assessments involve much detailed and time consuming work but it has been demonstrated that the resulting reliability improvements lead to savings in service costs which more than offset the cost of the evaluation.

  11. 新颖船舶燃油锅炉模拟实验系统的研制%An Original Simulation Experiment System of Marine Fuel Boiler

    Institute of Scientific and Technical Information of China (English)

    严华; 杨文中

    2012-01-01

    For marine fuel boiler control object of pluralism, on the basis of introduction for its composition and functions, the paper builds a new experimental simulation system of marine fuel boiler In order to realistically reflect the working principle and processes, the boiler body and simulation physical modeling of boiler control box are established with a combustion and water level signal detection circuit. A combustion and water level control process is programmed by PLC. Practical applications verify the feasibility of the system, and resolved the problems in the teaching of ship fuel boiler%针对船舶燃油辅锅炉控制对象的多元性,在简要介绍其组成及功能的基础上,构建了一种新颖的船舶燃油锅炉实验模拟系统。为了逼真反映船舶燃油锅炉工作原理和工作过程,建立了锅炉本体及燃油锅炉控制箱的仿真实物模型,设计了燃烧、水位信号检测电路,利用PLC开发燃烧过程和水位控制程序。实际应用验证了该模拟系统的可行性,解决了船舶燃油锅炉教学上的难题。

  12. Plutonium in an enduring fuel cycle

    Energy Technology Data Exchange (ETDEWEB)

    Pillay, K.K.S.

    1998-05-01

    Nuclear fuel cycles evolved over the past five decades have allowed many nations of the world to enjoy the benefits of nuclear energy, while contributing to the sustainable consumption of the world`s energy resources. The nuclear fuel cycle for energy production suffered many traumas since the 1970s because of perceived risks of proliferation of nuclear weapons. However, the experience of the past five decades has shown that the world community is committed to safeguarding all fissile materials and continuing the use of nuclear energy resources. Decisions of a few nations to discard spent nuclear fuels in geologic formations are contrary to the goals of an enduring nuclear fuel cycle and sustainable development being pursued by the world community. The maintenance of an enduring nuclear fuel cycle is dependent on sensible management of all the resources of the fuel cycle, including spent fuels.

  13. Fuel Cell Hydroge Manifold for Lift Trucks

    DEFF Research Database (Denmark)

    Hosseinzadeh, Elham

    Reducing CO2 emissions are getting more attention because of global warming. The transport sector which is responsible for a significant amount of emissions is going to reduce them due to new and upcoming regulations. Using fuel cells may be one way to help to reduce the emissions from this sector....... Battery driven lift trucks are being used more and more in different companies to reduce their emissions. However, battery driven lift trucks need long time to recharge and may be out of work for a long time. Fuel cell driven lift trucks diminish this problem and are therefore getting more attention....... The most common type of fuel cell used for automotive applications is PEM fuel cell. They are known for their high efficiency, low emissions and high reliability. However, lack of a hydrogen infrastructure, cost and durability of the stack is considered the biggest obstacles to the introduction of fuel...

  14. Reliability-Centric High-Level Synthesis

    CERN Document Server

    Tosun, S; Arvas, E; Kandemir, M; Xie, Yuan

    2011-01-01

    Importance of addressing soft errors in both safety critical applications and commercial consumer products is increasing, mainly due to ever shrinking geometries, higher-density circuits, and employment of power-saving techniques such as voltage scaling and component shut-down. As a result, it is becoming necessary to treat reliability as a first-class citizen in system design. In particular, reliability decisions taken early in system design can have significant benefits in terms of design quality. Motivated by this observation, this paper presents a reliability-centric high-level synthesis approach that addresses the soft error problem. The proposed approach tries to maximize reliability of the design while observing the bounds on area and performance, and makes use of our reliability characterization of hardware components such as adders and multipliers. We implemented the proposed approach, performed experiments with several designs, and compared the results with those obtained by a prior proposal.

  15. The rating reliability calculator

    Directory of Open Access Journals (Sweden)

    Solomon David J

    2004-04-01

    Full Text Available Abstract Background Rating scales form an important means of gathering evaluation data. Since important decisions are often based on these evaluations, determining the reliability of rating data can be critical. Most commonly used methods of estimating reliability require a complete set of ratings i.e. every subject being rated must be rated by each judge. Over fifty years ago Ebel described an algorithm for estimating the reliability of ratings based on incomplete data. While his article has been widely cited over the years, software based on the algorithm is not readily available. This paper describes an easy-to-use Web-based utility for estimating the reliability of ratings based on incomplete data using Ebel's algorithm. Methods The program is available public use on our server and the source code is freely available under GNU General Public License. The utility is written in PHP, a common open source imbedded scripting language. The rating data can be entered in a convenient format on the user's personal computer that the program will upload to the server for calculating the reliability and other statistics describing the ratings. Results When the program is run it displays the reliability, number of subject rated, harmonic mean number of judges rating each subject, the mean and standard deviation of the averaged ratings per subject. The program also displays the mean, standard deviation and number of ratings for each subject rated. Additionally the program will estimate the reliability of an average of a number of ratings for each subject via the Spearman-Brown prophecy formula. Conclusion This simple web-based program provides a convenient means of estimating the reliability of rating data without the need to conduct special studies in order to provide complete rating data. I would welcome other researchers revising and enhancing the program.

  16. Reliability of power connections

    Institute of Scientific and Technical Information of China (English)

    BRAUNOVIC Milenko

    2007-01-01

    Despite the use of various preventive maintenance measures, there are still a number of problem areas that can adversely affect system reliability. Also, economical constraints have pushed the designs of power connections closer to the limits allowed by the existing standards. The major parameters influencing the reliability and life of Al-Al and Al-Cu connections are identified. The effectiveness of various palliative measures is determined and the misconceptions about their effectiveness are dealt in detail.

  17. RERTR Fuel Developmemt and Qualification Plan

    Energy Technology Data Exchange (ETDEWEB)

    Dan Wachs

    2007-01-01

    In late 2003 it became evident that U-Mo aluminum fuels under development exhibited significant fuel performance problems under the irradiation conditions required for conversion of most high-powered research reactors. Solutions to the fuel performance issue have been proposed and show promise in early testing. Based on these results, a Reduced Enrichment Research and Test Reactor (RERTR) program strategy has been mapped to allow generic fuel qualification to occur prior to the end of FY10 and reactor conversion to occur prior to the end of FY14. This strategy utilizes a diversity of technologies, test conditions, and test types. Scoping studies using miniature fuel plates will be completed in the time frame of 2006-2008. Irradiation of larger specimens will occur in the Advanced Test Reactor (ATR) in the United States, the Belgian Reactor-2 (BR2) reactor in Belgium, and in the OSIRIS reactor in France in 2006-2009. These scoping irradiation tests provide a large amount of data on the performance of advanced fuel types under irradiation and allow the down selection of technology for larger scale testing during the final stages of fuel qualification. In conjunction with irradiation testing, fabrication processes must be developed and made available to commercial fabricators. The commercial fabrication infrastructure must also be upgraded to ensure a reliable low enriched uranium (LEU) fuel supply. Final qualification of fuels will occur in two phases. Phase I will obtain generic approval for use of dispersion fuels with density less than 8.5 g-U/cm3. In order to obtain this approval, a larger scale demonstration of fuel performance and fabrication technology will be necessary. Several Materials Test Reactor (MTR) plate-type fuel assemblies will be irradiated in both the High Flux Reactor (HFR) and the ATR (other options include the BR2 and Russian Research Reactor, Dmitrovgrad, Russia [MIR] reactors) in 2008-2009. Following postirradiation examination, a report

  18. Multidisciplinary System Reliability Analysis

    Science.gov (United States)

    Mahadevan, Sankaran; Han, Song; Chamis, Christos C. (Technical Monitor)

    2001-01-01

    The objective of this study is to develop a new methodology for estimating the reliability of engineering systems that encompass multiple disciplines. The methodology is formulated in the context of the NESSUS probabilistic structural analysis code, developed under the leadership of NASA Glenn Research Center. The NESSUS code has been successfully applied to the reliability estimation of a variety of structural engineering systems. This study examines whether the features of NESSUS could be used to investigate the reliability of systems in other disciplines such as heat transfer, fluid mechanics, electrical circuits etc., without considerable programming effort specific to each discipline. In this study, the mechanical equivalence between system behavior models in different disciplines are investigated to achieve this objective. A new methodology is presented for the analysis of heat transfer, fluid flow, and electrical circuit problems using the structural analysis routines within NESSUS, by utilizing the equivalence between the computational quantities in different disciplines. This technique is integrated with the fast probability integration and system reliability techniques within the NESSUS code, to successfully compute the system reliability of multidisciplinary systems. Traditional as well as progressive failure analysis methods for system reliability estimation are demonstrated, through a numerical example of a heat exchanger system involving failure modes in structural, heat transfer and fluid flow disciplines.

  19. Bioprospecting--fuels from fungi.

    Science.gov (United States)

    Strobel, Gary Allan

    2015-05-01

    The world has a continuing demand and utility for liquid fuels to power its societies. The utilization of crude oil based fuels is leading to a dramatic increase in the CO2 content of the atmosphere which is being related to a dangerously warming earth. Having liquid fuels that are derived from biological sources is one solution to this growing problem since the carbon being utilized is only from recycled sources. Presently, the microbes, having the greatest impact on the world's economies, producing liquid fuel are various yeasts producing ethanol. Other microbial sources need to be sought since ethanol is not the most desirable fuel and yeasts require simple sugars to carry out the fermentation processes. Recently, several endophytic fungi have been described that make hydrocarbons with fuel potential (Mycodiesel). Among others the compounds found in the volatile phases of these cultures include alkanes, branched alkanes, cyclohexanes, cyclopentanes, and alkyl alcohols/ketones, benzenes and polyaromatic hydrocarbons. Most importantly, generally these organisms make hydrocarbons while utilizing complex carbohydrates found in all plant-based agricultural wastes. Also discussed in this review is a rationale for finding hydrocarbon producing endophytes as well as examples of other promising hydrocarbon producers-Nodulisporium spp. which make 1,8-cineole and families of other hydrocarbons. Extremely favorable results of engine and fuel testing experiments recently completed on cineole and other products of Nodulisporium sp. are also presented. Finally, there is a brief discussion on the main limiting steps in the domestication of these fungi.

  20. Sensitivity Analysis of Component Reliability

    Institute of Scientific and Technical Information of China (English)

    ZhenhuaGe

    2004-01-01

    In a system, Every component has its unique position within system and its unique failure characteristics. When a component's reliability is changed, its effect on system reliability is not equal. Component reliability sensitivity is a measure of effect on system reliability while a component's reliability is changed. In this paper, the definition and relative matrix of component reliability sensitivity is proposed, and some of their characteristics are analyzed. All these will help us to analyse or improve the system reliability.

  1. Equipamento para medição do consumo de combustível em experimentos agrícolas An equipment for measuring tractor fuel consumption in agricultural experiments

    Directory of Open Access Journals (Sweden)

    José Valdemar Gonzalez Maziero

    1992-01-01

    Full Text Available É descrito e aferido (em condições de laboratório um equipamento para medição de consumo de combustível para uso em experimentos com máquinas agrícolas. O medidor, construído com tubos-reservatórios de PVC, tubo de vidro graduado, tanque plástico de combustível e eletroválvulas (12 VCC, é ligado ao sistema de alimentação do trator com mangueiras de plástico de baixa pressão, controlando-se o fluxo de combustível mediante uma chave elétrica liga/desliga. Faz parte do conjunto um medidor de temperatura para possibilitar o cálculo da densidade do combustível, quando necessário medir seu consumo específico. O equipamento, desenvolvido pela Seção de Máquinas de Tração e de Potência, é simples, econômico, de fácil utilização, e tem precisão adequada para medir consumo de combustível variando de 5,0 a 50,0 l/h.A description and test's results of an equipment for measuring tractor fuel consumption in agricultural experiments are presented. The equipment was constructed with two reservoir tanks made of PVC tube, a feeder tank, a graduated glass tube and solenoidal valves (12 VCC which are connected to the tractor fuel system with low pressure hoses. The flow is controlled by input/output key. A thermometer integrates the equipment for determining the density of fuel when it is necessary to measure the specific fuel consumption. This equipment developed by the Seção de Máquinas de Tração e de Potência, State of São Paulo, Brazil, is simple, inexpensive, easy to use and has satisfactory accuracy for measuring tractor fuel consumption from 5.0 to 50.0 l/h.

  2. Experiment on fuel flexibility of biomass pellet burner%生物质颗粒燃烧器燃料适应性试验

    Institute of Scientific and Technical Information of China (English)

    王月乔; 田宜水; 侯书林; 赵立欣; 孟海波

    2014-01-01

    为深入研究生物质颗粒燃料的燃烧特性,探讨自动燃烧器的燃料适应性,该文基于PB-20型生物质颗粒燃烧器,选择了5种灰分小于25%(空气干燥基)的颗粒燃料,分别研究了燃烧工况中进料量和空气量对燃烧性能的影响。试验结果表明灰分含量大于20%的颗粒燃料燃烧不充分,工况不稳定,效率低,结渣大,易熄火,不适用于此类生物质颗粒燃烧器;灰分含量为12.40%的颗粒燃料推荐参数为进料量4 kg/h,风机转速2600~2800 r/min,清渣速度为3 r/min,转5 s/停35 s;灰分在7.21%的颗粒燃料推荐控制参数为进料量3~4 kg/h,风机转速2600~2800 r/min,清渣速度相对应为3 r/min,转5 s/停60~55 s;灰分值低于1%的颗粒燃料均以进料量3~4 kg/h,风机转速2600~2800 r/min,不需清渣为推荐参数。该研究总结了生物质颗粒燃烧器的燃料适用控制参数,为燃烧器的推广应用提供了数据支持。%Because there exists much diversity in raw materials, biomass fuel pellet properties, and corresponding combustion equipment, research to develop the fuel adaptability of biomass burners is necessary. The research was accomplished on a self-build biomass combustion equipment-monitoring platform. The monitoring platform has multiple sensors to collect and process data of the burner’s control parameters and combustion state parameters. Based on the platform, the author used a PB-20-type biomass pellet burner, which is designed by the Chinese Academy of Agricultural Engineering. The author investigated five kinds of biomass pellets with ash values from 0 to 25 percent, And tested nine kinds of working conditions for each pellet with 3, 4, and 5 kg/h fuel feed rates and 2 600, 2 700, and 2 800 r/min fan speed. The thermal performance of the burner was tested according to the GB/T10180-2003 Thermal performance test code for industrial boilers and the GB13271-2001 Emission

  3. Offshore wind turbines reliability, availability and maintenance

    CERN Document Server

    Tavner, Peter

    2012-01-01

    The first book to specifically focus on offshore wind turbine technology and which addresses practically wind turbine reliability and availability. The book draws on the author's experience of power generation reliability and availability and the condition monitoring of that plant to describe the problems facing the developers of offshore wind farms and the solutions available to them to raise availability, reduce cost of energy and improve through life cost.

  4. Dissolution experiments of commercial PWR (52 MWd/kgU) and BWR (53 MWd/kgU) spent nuclear fuel cladded segments in bicarbonate water under oxidizing conditions. Experimental determination of matrix and instant release fraction

    Science.gov (United States)

    González-Robles, E.; Serrano-Purroy, D.; Sureda, R.; Casas, I.; de Pablo, J.

    2015-10-01

    The denominated instant release fraction (IRF) is considered in performance assessment (PA) exercises to govern the dose that could arise from the repository. A conservative definition of IRF comprises the total inventory of radionuclides located in the gap, fractures, and the grain boundaries and, if present, in the high burn-up structure (HBS). The values calculated from this theoretical approach correspond to an upper limit that likely does not correspond to what it will be expected to be instantaneously released in the real system. Trying to ascertain this IRF from an experimental point of view, static leaching experiments have been carried out with two commercial UO2 spent nuclear fuels (SNF): one from a pressurized water reactor (PWR), labelled PWR, with an average burn-up (BU) of 52 MWd/kgU and fission gas release (FGR) of 23.1%, and one from a boiling water reactor (BWR), labelled BWR, with an average BU of and 53 MWd/kgU and FGR of 3.9%. One sample of each SNF, consisting of fuel and cladding, has been leached in bicarbonate water during one year under oxidizing conditions at room temperature (25 ± 5)°C. The behaviour of the concentration measured in solution can be divided in two according to the release rate. All radionuclides presented an initial release rate that after some days levels down to a slower second one, which remains constant until the end of the experiment. Cumulative fraction of inventory in aqueous phase (FIAPc) values has been calculated. Results show faster release in the case of the PWR SNF. In both cases Np, Pu, Am, Cm, Y, Tc, La and Nd dissolve congruently with U, while dissolution of Zr, Ru and Rh is slower. Rb, Sr, Cs and Mo, dissolve faster than U. The IRF of Cs at 10 and 200 days has been calculated, being (3.10 ± 0.62) and (3.66 ± 0.73) for PWR fuel, and (0.35 ± 0.07) and (0.51 ± 0.10) for BWR fuel.

  5. Reliability analysis and initial requirements for FC systems and stacks

    Science.gov (United States)

    Åström, K.; Fontell, E.; Virtanen, S.

    In the year 2000 Wärtsilä Corporation started an R&D program to develop SOFC systems for CHP applications. The program aims to bring to the market highly efficient, clean and cost competitive fuel cell systems with rated power output in the range of 50-250 kW for distributed generation and marine applications. In the program Wärtsilä focuses on system integration and development. System reliability and availability are key issues determining the competitiveness of the SOFC technology. In Wärtsilä, methods have been implemented for analysing the system in respect to reliability and safety as well as for defining reliability requirements for system components. A fault tree representation is used as the basis for reliability prediction analysis. A dynamic simulation technique has been developed to allow for non-static properties in the fault tree logic modelling. Special emphasis has been placed on reliability analysis of the fuel cell stacks in the system. A method for assessing reliability and critical failure predictability requirements for fuel cell stacks in a system consisting of several stacks has been developed. The method is based on a qualitative model of the stack configuration where each stack can be in a functional, partially failed or critically failed state, each of the states having different failure rates and effects on the system behaviour. The main purpose of the method is to understand the effect of stack reliability, critical failure predictability and operating strategy on the system reliability and availability. An example configuration, consisting of 5 × 5 stacks (series of 5 sets of 5 parallel stacks) is analysed in respect to stack reliability requirements as a function of predictability of critical failures and Weibull shape factor of failure rate distributions.

  6. Reliability engineering theory and practice

    CERN Document Server

    Birolini, Alessandro

    2017-01-01

    This book shows how to build in and assess reliability, availability, maintainability, and safety (RAMS) of components, equipment, and systems. It presents the state of the art of reliability (RAMS) engineering, in theory & practice, and is based on over 30 years author's experience in this field, half in industry and half as Professor of Reliability Engineering at the ETH, Zurich. The book structure allows rapid access to practical results. Methods & tools are given in a way that they can be tailored to cover different RAMS requirement levels. Thanks to Appendices A6 - A8 the book is mathematically self-contained, and can be used as a textbook or as a desktop reference with a large number of tables (60), figures (210), and examples / exercises^ 10,000 per year since 2013) were the motivation for this final edition, the 13th since 1985, including German editions. Extended and carefully reviewed to improve accuracy, it represents the continuous improvement effort to satisfy reader's needs and confidenc...

  7. Modeling Of Proton Exchange Membrane Fuel Cell Systems

    DEFF Research Database (Denmark)

    Nielsen, Mads Pagh

    The objective of this doctoral thesis was to develop reliable steady-state and transient component models suitable to asses-, develop- and optimize proton exchange membrane (PEM) fuel cell systems. Several components in PEM fuel cell systems were characterized and modeled. The developed component...

  8. Monitoring instrumentation spent fuel management program. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1979-01-01

    Preliminary monitoring system methodologies are identified as an input to the risk assessment of spent fuel management. Conceptual approaches to instrumentation for surveillance of canister position and orientation, vault deformation, spent fuel dissolution, temperature, and health physics conditions are presented. In future studies, the resolution, reliability, and uncertainty associated with these monitoring system methodologies will be evaluated.

  9. History of fast reactor fuel development

    Energy Technology Data Exchange (ETDEWEB)

    Kittel, J.H. (Argonne National Lab., IL (United States)); Frost, B.R.T. (Argonne National Lab., IL (United States)); Mustelier, J.P. (COGEMA, Velizy-Villacoublay (France)); Bagley, K.Q. (AEA Reactor Services, Risley (United Kingdom)); Crittenden, G.C. (AEA Reactor Services, Dounreay (United Kingdom)); Dievoet, J. van (Belgonucleaire, Brussels (Belgium))

    1993-09-01

    The first fast breeder eactors, constructed in the 1945-1960 time period, used metallic fuels composed of uranium, plutonium, or their alloys. They were chosen because most existing reactor operating experience had been obtained on metallic fuels and because they provided the highest breeding ratios. Difficulties in obtaining adequate dimensional stability in metallic fuel elements under conditions of high fuel burnup led in the 1960s to the virtual worldwide choice of ceramic fuels. Although ceramic fuels provide lower breeding performance, this objective is no longer an important consideration in most national programs. Mixed uranium and plutonium dioxide became the ceramic fuel that has received the widest use. The more advanced ceramic fuels, mixed uranium and plutonium carbides and nitrides, continue under development. More recently, metal fuel elements of improved design have joined ceramic fuels in achieving goal burnups of 15 to 20 percent. Low-swelling fuel cladding alloys have also been continuously developed to deal with the unexpected problem of void formation in stainless steels subjected to fast neutron irradiation, a phenomenon first observed in the 1960s. (orig.)

  10. Operation of the nuclear fuel cycle test facilities -Operation of the hot test loop facilities

    Energy Technology Data Exchange (ETDEWEB)

    Chun, S. Y.; Jeong, M. K.; Park, C. K.; Yang, S. K.; Won, S. Y.; Song, C. H.; Jeon, H. K.; Jeong, H. J.; Cho, S.; Min, K. H.; Jeong, J. H.

    1997-01-01

    A performance and reliability of a advanced nuclear fuel and reactor newly designed should be verified by performing the thermal hydraulics tests. In thermal hydraulics research team, the thermal hydraulics tests associated with the development of an advanced nuclear fuel and reactor haven been carried out with the test facilities, such as the Hot Test Loop operated under high temperature and pressure conditions, Cold Test Loop, RCS Loop and B and C Loop. The objective of this project is to obtain the available experimental data and to develop the advanced measuring techniques through taking full advantage of the facilities. The facilities operated by the thermal hydraulics research team have been maintained and repaired in order to carry out the thermal hydraulics tests necessary for providing the available data. The performance tests for the double grid type bottom end piece which was improved on the debris filtering effectivity were performed using the PWR-Hot Test Loop. The CANDU-Hot Test Loop was operated to carry out the pressure drop tests and strength tests of CANFLEX fuel. The Cold Test Loop was used to obtain the local velocity data in subchannel within HANARO fuel bundle and to study a thermal mixing characteristic of PWR fuel bundle. RCS thermal hydraulic loop was constructed and the experiments have been carried out to measure the critical heat flux. In B and C Loop, the performance tests for each component were carried out. (author). 19 tabs., 78 figs., 19 refs.

  11. Robustness in the design and manufacture of the AP1000 fuel assembly

    Energy Technology Data Exchange (ETDEWEB)

    Sumit, Ray [New Reactor Fuel Engineering, Westinghouse Electric Corporation, Monroeville, PA (United States)

    2009-06-15

    This paper will describe the significant set of measures that are being taken by Westinghouse to ensure that the fuel for AP1000 reactors operates flawlessly and meets all of the requirements of the INPO 2010 from the very beginning of plant operation. The INPO 2010 initiatives and the associated EPRI Fuel Reliability Guidelines, developed by utilities and fuel vendors under EPRI sponsorship, provide a valuable template that Westinghouse has been following in the design and development of the AP1000 fuel assembly, as well in the planning for the manufacturing campaign. In addition, planning is underway for surveillance programs that will provide early feedback on AP1000 fuel performance trends. The Westinghouse AP1000 flawless fuel program consists of four main elements. These are: 1) Implement a comprehensive set of measures in the design and manufacture of AP1000 fuel to ensure that all possible defect mechanisms have been addressed in as proactive a manner as possible 2) Address any plant design issues during the AP1000 plant design finalization process that can adversely impact fuel performance 3) Specify bounds of reactor operation and implement through a monitoring process using the Westinghouse BEACON{sup TM} software and 4) Support the above with a set of robust post irradiation programs to obtain early feedback on fuel performance. The key fuel failure mechanisms addressed are consistent with Westinghouse experience as well as the INPO 2010 initiatives. These include grid to rod fretting, PCI, debris, crud induced corrosion and manufacturing related issues that can lead to fuel failure. This paper will describe the specific analysis, testing, as well as the design and manufacturing process enhancements that are being incorporated into the AP1000 fuel design to address each one of these mechanisms. The risk factors assessed for each failure mechanism are based on extensive Westinghouse as well as the broader industry experience, with specific focus on the

  12. Preliminary ecotoxicity assessment of new generation alternative fuels in seawater.

    Science.gov (United States)

    Rosen, Gunther; Dolecal, Renee E; Colvin, Marienne A; George, Robert D

    2014-06-01

    The United States Navy (USN) is currently demonstrating the viability of environmentally sustainable alternative fuels to power its fleet comprised of aircraft and ships. As with any fuel used in a maritime setting, there is potential for introduction into the environment through transport, storage, and spills. However, while alternative fuels are often presumed to be eco-friendly relative to conventional petroleum-based fuels, their environmental fate and effects on marine environments are essentially unknown. Here, standard laboratory-based toxicity experiments were conducted for two alternative fuels, jet fuel derived from Camelina sativa (wild flax) seeds (HRJ5) and diesel fuel derived from algae (HRD76), and two conventional counterparts, jet fuel (JP5) and ship diesel (F76). Initial toxicity tests performed on water-accommodated fractions (WAF) from neat fuels partitioned into seawater, using four standard marine species in acute and chronic/sublethal tests, indicate that the alternative fuels are significantly less toxic to marine organisms.

  13. Thermally regenerative hydrogen/oxygen fuel cell power cycles

    Science.gov (United States)

    Morehouse, J. H.

    1986-01-01

    Two innovative thermodynamic power cycles are analytically examined for future engineering feasibility. The power cycles use a hydrogen-oxygen fuel cell for electrical energy production and use the thermal dissociation of water for regeneration of the hydrogen and oxygen. The TDS (thermal dissociation system) uses a thermal energy input at over 2000 K to thermally dissociate the water. The other cycle, the HTE (high temperature electrolyzer) system, dissociates the water using an electrolyzer operating at high temperature (1300 K) which receives its electrical energy from the fuel cell. The primary advantages of these cycles is that they are basically a no moving parts system, thus having the potential for long life and high reliability, and they have the potential for high thermal efficiency. Both cycles are shown to be classical heat engines with ideal efficiency close to Carnot cycle efficiency. The feasibility of constructing actual cycles is investigated by examining process irreversibilities and device efficiencies for the two types of cycles. The results show that while the processes and devices of the 2000 K TDS exceed current technology limits, the high temperature electrolyzer system appears to be a state-of-the-art technology development. The requirements for very high electrolyzer and fuel cell efficiencies are seen as determining the feasbility of the HTE system, and these high efficiency devices are currently being developed. It is concluded that a proof-of-concept HTE system experiment can and should be conducted.

  14. THE AIRLINE'S RELIABILITY PROGRAM

    OpenAIRE

    Тамаргазін, О. А.; Національний авіаційний університет; Власенко, П. О.; Національний авіаційний університет

    2013-01-01

    Airline's operational structure for Reliability program implementation — engineering division, reliability  division, reliability control division, aircraft maintenance division, quality assurance division — was considered. Airline's Reliability program structure is shown. Using of Reliability program for reducing costs on aircraft maintenance is proposed. Рассмотрена организационная структура авиакомпании по выполнению Программы надежности - инженерный отдел, отделы по надежности авиацио...

  15. Ultra reliability at NASA

    Science.gov (United States)

    Shapiro, Andrew A.

    2006-01-01

    Ultra reliable systems are critical to NASA particularly as consideration is being given to extended lunar missions and manned missions to Mars. NASA has formulated a program designed to improve the reliability of NASA systems. The long term goal for the NASA ultra reliability is to ultimately improve NASA systems by an order of magnitude. The approach outlined in this presentation involves the steps used in developing a strategic plan to achieve the long term objective of ultra reliability. Consideration is given to: complex systems, hardware (including aircraft, aerospace craft and launch vehicles), software, human interactions, long life missions, infrastructure development, and cross cutting technologies. Several NASA-wide workshops have been held, identifying issues for reliability improvement and providing mitigation strategies for these issues. In addition to representation from all of the NASA centers, experts from government (NASA and non-NASA), universities and industry participated. Highlights of a strategic plan, which is being developed using the results from these workshops, will be presented.

  16. Aviation fuels outlook

    Science.gov (United States)

    Momenthy, A. M.

    1980-01-01

    Options for satisfying the future demand for commercial jet fuels are analyzed. It is concluded that the most effective means to this end are to attract more refiners to the jet fuel market and encourage development of processes to convert oil shale and coal to transportation fuels. Furthermore, changing the U.S. refineries fuel specification would not significantly alter jet fuel availability.

  17. Alternative Fuel Research in Fischer-Tropsch Synthesis

    Science.gov (United States)

    Surgenor, Angela D.; Klettlinger, Jennifer L.; Yen, Chia H.; Nakley, Leah M.

    2011-01-01

    NASA Glenn Research Center has recently constructed an Alternative Fuels Laboratory which is solely being used to perform Fischer-Tropsch (F-T) reactor studies, novel catalyst development and thermal stability experiments. Facility systems have demonstrated reliability and consistency for continuous and safe operations in Fischer-Tropsch synthesis. The purpose of this test facility is to conduct bench scale Fischer-Tropsch (F-T) catalyst screening experiments while focusing on reducing energy inputs, reducing CO2 emissions and increasing product yields within the F-T process. Fischer-Tropsch synthesis is considered a gas to liquid process which reacts syn-gas (a gaseous mixture of hydrogen and carbon monoxide), over the surface of a catalyst material which is then converted into liquids of various hydrocarbon chain length and product distributions1. These hydrocarbons can then be further processed into higher quality liquid fuels such as gasoline and diesel. The experiments performed in this laboratory will enable the investigation of F-T reaction kinetics to focus on newly formulated catalysts, improved process conditions and enhanced catalyst activation methods. Currently the facility has the capability of performing three simultaneous reactor screening tests, along with a fourth fixed-bed reactor used solely for cobalt catalyst activation.

  18. Post irradiation examination of HANARO nucler mini-element fuel (metallographic and density test)

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Byung Ok; Hong, K. P.; Park, D. G.; Choo, Y. S.; Baik, S. J.; Kim, K. H.; Kim, H. C.; Jung, Y. H

    2001-05-01

    The post irradiation examination of a HANARO mini-element nuclear fuel, KH96C-004, was done in June 6, 2000. The purpose of this project is to evaluate the in-core performance and reliability of mini-element nuclear fuel for HANARO developed by the project ''The Nuclear Fuel Material Development of Research Reactor''. And, in order to examine the performance of mini-element nuclear fuel in normal output condition, the post irradiation examination of a nuclear fuel bundle composed by 6 mini nuclear fuel rods and 12 dummy fuel rods was performed. Based on these examination results, the safety and reliability of HANARO fuel and the basic data on the design of HANARO nuclear fuel can be ensured and obtained,.

  19. A Novel Two-Terminal Reliability Analysis for MANET

    OpenAIRE

    Xibin Zhao; Zhiyang You; Hai Wan

    2013-01-01

    Mobile ad hoc network (MANET) is a dynamic wireless communication network. Because of the dynamic and infrastructureless characteristics, MANET is vulnerable in reliability. This paper presents a novel reliability analysis for MANET. The node mobility effect and the node reliability based on a real MANET platform are modeled and analyzed. An effective Monte Carlo method for reliability analysis is proposed. A detailed evaluation is performed in terms of the experiment results.

  20. A Novel Two-Terminal Reliability Analysis for MANET

    Directory of Open Access Journals (Sweden)

    Xibin Zhao

    2013-01-01

    Full Text Available Mobile ad hoc network (MANET is a dynamic wireless communication network. Because of the dynamic and infrastructureless characteristics, MANET is vulnerable in reliability. This paper presents a novel reliability analysis for MANET. The node mobility effect and the node reliability based on a real MANET platform are modeled and analyzed. An effective Monte Carlo method for reliability analysis is proposed. A detailed evaluation is performed in terms of the experiment results.