Modeling of fuel retention in the pre-damaged tungsten with MeV W ions after exposure to D plasma

Directory of Open Access Journals (Sweden)

Zhenhou Wang

2017-12-01

Full Text Available Modeling of high-Z ion irradiated-induced damages on fuel retention inside tungsten (W material has been performed in this work. The upgraded Hydrogen Isotope Inventory Processes Code (HIIPC is applied to model the deuterium (D retention inside pre-damaged W during exposed to low-energy D flux, and the W is pre-irradiated by 20 MeV W-ion before exposed to D flux. Three types of trap, i.e. mono-vacancies, dislocations and grain boundary vacancies, are considered in the present model. The mono-vacancy defects induced by energetic W ions are calculated by SRIM code. First, the model is validated against the available experimental data under the same D flux exposure conditions, showing the reasonable agreement. Then, the effect of radiation-induced defects produced by pre-exposed energetic W-ion with different energy and fluence on the fuel retention are studied, confirming that the irradiation-induced traps play a dominated role on the fuel retention in the surface of the material (∼ micrometer. Finally, the effects of different type of defect, D fluence, and wall temperature on the fuel retention are discussed systemically, and these modeling results are in well agreement with the previous studies.

Fuel poverty pre-diagnosis. Challenges, methods and comparison between Ile-de-France and national tools

International Nuclear Information System (INIS)

Boitel, Marc; Ceron, Pascale; Faure, Elise; Collinet, Sophie; Guillemot, Celia; Erard, Timothee

2016-01-01

Many initiatives and tools have been developed for many years to identify and evaluate fuel poverty over a local, regional or national territory. The multiplicity of available tools leads to complex choice for a territory approach. Through this document, the Iddri Institute and the ARENE Agency provide communities with a recap of today's identified challenges and methods for fuel poverty characterization in a given territory. The document presents a comparative evaluation and some tool sheets for the available pre-diagnostic solutions in the Ile-de-France and national territories

Pre-irradiation testing of experimental fuel elements

International Nuclear Information System (INIS)

Basova, B.G.; Davydov, E.F.; Dvoretskij, V.G.; Ivanov, V.B.; Syuzev, V.N.; Timofeev, G.A.; Tsykanov, V.A.

1979-01-01

The problems of testing of experimental fuel elements of nuclear reactors on the basis of complex accountancy of the factors defining operating capacity of the fuel elements are considered. The classification of the parameters under control and the methods of initial technological testing, including testing of the fuel product, cladding and fished fuel element, is given. The requirements to the apparatus used for complex testing are formulated. One of the possible variants of representation of the information obtained in the form of the input certificate of a single fuel element under study is proposed. The processing flowsheet of the gathered information using the computer is given. The approach under consideration is a methodological basis of investigation of fuel element operating life at the testing stage of the experimental fuel elements

Pre-treatment of waste fuel with low-speed shredding and screening for fluidized bed incineration; Foerbehandling av avfallsbraensle foer fluidbaeddpannor med laangsamtgaaende valskross och saekerhetssiktning

Energy Technology Data Exchange (ETDEWEB)

Hermansson, Sven; Victoren, Anders; Niklasson, Fredrik; Jones, Frida

2013-09-01

In FB combustion of waste, an important cost factor is the pre-treatment of the waste fuel. The most common method of final levigation of the waste fuel is using hammer mills, which crushes the fuel with high force and high rotational speed. The advantage of the powerful hammer mill is, however, also a disadvantage. The fraction of fines becomes large, and the method is experienced to cause high maintenance costs and problems with accidental fires. A plausible alternative to the hammer mill is the shredder. The rotational speed of the shreeder is lower, while it cutting and slicing the waste fuel instead of grinding it. The shredder is, therefore, expected to yield less wear and tear, lower electricity consumption and less accidental fires. On the other hand, the shreeder may yield a higher fraction of oversized fuel particles, which could cause problems in the combustion, especially in smaller FB-plants with one single fuel supply conveyor. In this project, the framing of question has been if low-speed shredding in combination with screening of over sizes fuel particles, may function for smaller FB plants with one single fuel supplying conveyor. The aim of the project has been to support FB plant owners and manufacturers for independent comparision of the different fuel pre-treatment methods, via pre-treatment and combustions trials and economical comparisons. The concept of lowspeed shreddning and screening has been compared economically with a traditional hammer mill system and a shredding system designed for a larger FB plant. Moreover, combustion trials have been carried out with shredded and screened fuel, and hammer milled fuel, in two smaller parallel FB furnaces with one single fuel supplying conveyor per furnace. The fuels were analysed for particle size distribution and composition, and the operation during the combustion trial was evaluated. The economical evaluation of the new pre-treatment concept, with lowspeed shredding and screening, yielded an

Investigating the reactivity controlled compression ignition (RCCI) combustion strategy in a natural gas/diesel fueled engine with a pre-chamber

International Nuclear Information System (INIS)

Salahi, Mohammad Mahdi; Esfahanian, Vahid; Gharehghani, Ayatallah; Mirsalim, Mostafa

2017-01-01

Highlights: • A novel combustion strategy, RCCI with a pre-chamber, is proposed and investigated. • The proposed strategy extends the RCCI operating range to use less intake air temperatures. • The new concept extends the RCCI operating range to use lower portions of the active fuel. • The proposed strategy is sensitive to engine load and is more efficient for high loads. - Abstract: Reactivity controlled compression ignition (RCCI) concept has been proven to be a promising combustion mode for the next generations of internal combustion engines. This strategy is still subject of extensive studies to overcome its operational limitations. In the present work, the effect of using a pre-chamber to extend some operating ranges in a RCCI engine is investigated using coupled multidimensional computational fluid dynamics (CFD) with detailed chemical kinetic mechanisms. To accomplish this, the combustion and flow field in a single cylinder engine with a pre-chamber, working in RCCI mode and fueled with natural gas/diesel are numerically modeled. Experimental data is used to validate the simulation results and then, combustion characteristics and engine emissions in some various operating regions, in terms of initial temperature, fuel equivalence ratio and portions of the two fuels are discussed. The results reveal that the proposed strategy provides the ability to extend the engine operating ranges to use lower intake temperatures, even to 50 K lower for some cases, and also using a larger portion of natural gas instead of diesel fuel. On the other hand, the new strategy could result in incomplete combustion and formation of related emissions in low loads, but for higher engine loads it shows better combustion characteristics.

Study on homogeneous charge diesel combustion engine. 4th Report. Search for low emission combustion method with diesel fuel pre-mixture; Kin`itsu kongo asshuku chakka diesel kikan ni kansuru kenkyu. 4. Keiyu yokongoka deno tei emission no kanosei

Energy Technology Data Exchange (ETDEWEB)

Suzuki, H; Koike, S; Odaka, M [Traffic Safety and Nuisance Research Inst., Tokyo (Japan)

1997-10-01

Single fuel operation with diesel fuel has been tried experimentally for the Homogeneous Charge Diesel Combustion method (HCDC). The higher the pre-mixed fuel ratio, the lower the emissions. But diesel knock due to early self ignition may be occurred under high pre-mixed fuel ratio conditions and consequently the maximum pre-mixed fuel ratio is restricted by these knock limits. Full load operations with higher pre-mixed fuel ratio can be possible with a supercharging which improve the knock limits and emissions. 8 refs., 12 figs.

Experimental data report for Test TS-1 Reactivity Initiated Accident Test in NSRR with pre-irradiated BWR fuel rod

International Nuclear Information System (INIS)

Nakamura, Takehiko; Yoshinaga, Makio; Sobajima, Makoto; Fujishiro, Toshio; Horiki, Ohichiro; Yamahara, Takeshi; Ichihashi, Yoshinori; Kikuchi, Teruo

1992-01-01

This report presents experimental data for Test TS-1 which was the first in a series of tests, simulating Reactivity Initiated Accident (RIA) conditions using pre-irradiated BWR fuel rods, performed in the Nuclear Safety Research Reactor (NSRR) in October, 1989. Test fuel rod used in the Test TS-1 was a short-sized BWR (7 x 7) type rod which was fabricated from a commercial rod provided from Tsuruga Unit 1 power reactor. The fuel had an initial enrichment of 2.79 % and burnup of 21.3 GWd/t (bundle average). Pulse irradiation was performed at a condition of stagnant water cooling, atmospheric pressure and ambient temperature using a newly developed double container-type capsule. Energy deposition of the rod in this test was evaluated to be about 61 cal/g·fuel (55 cal/g·fuel in peak fuel enthalpy) and no fuel failure was observed. Descriptions on test conditions, test procedures, fuel burnup measurements, transient behavior of the test rod during pulse irradiation and results of post pulse irradiation examinations are contained in this report. (author)

Method for pre-processing LWR spent fuel

International Nuclear Information System (INIS)

Otsuka, Katsuyuki; Ebihara, Hikoe.

1986-01-01

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

Burnup calculation with estimated neutron spectrum of JMTR irradiation field. Development of the burnup calculation method for fuel pre-irradiated in the JMTR

International Nuclear Information System (INIS)

Okonogi, Kazunari; Nakamura, Takehiko; Yoshinaga, Makio; Hosoyamada, Ryuji

1999-03-01

As a series of the pulse irradiation tests with the irradiated fuel, the high-enriched fuel rods pre-irradiated in the JMTR as well as the fuels irradiated in commercial reactors have been irradiated in the NSRR. In the pre-irradiation at the JMTR, the test fuels were placed at the irradiation holes in the reflector region far from the driver core to keep the linear heat generation rate of the test fuel low. Accordingly, neutron energy spectra of the irradiation holes for the test fuels are softened due to the higher moderator ratio than in those of the ordinary LWR core, which causes quite different burnup characteristics. JMTR post irradiation condition corresponds to the pre-test condition in the NSRR. Therefore, proper understanding of the condition is quite important for the precise evaluating the energy deposition and FP generation in the test. Then, neutron spectra at the JMTR irradiation field were evaluated and its effects on the burnup calculation were quantified. Basing on the configuration of the JMTR core in the operation cycle No.85, neutron diffusion calculations of 107 groups were executed in 2-D slab (X-Y) geometry of CITATION of SRAC95 code system, and neutron energy spectra of the irradiation hole for the test fuels were evaluated. Burnup calculations of Test JMN-1 fuel with the estimated neutron energy spectra were performed and the results were compared to both the measurements and calculation results with the PWR and BWR libraries in ORIGEN2 code. SWAT code was used to collapse the 107 groups spectra into 1 group libraries for the ORIGEN2 use. The calculation results for both the generation and depletion of U, Pu and Nd with the JMTR libraries obtained in the present study were in the reasonably good agreement with the measurements, while in the case of calculation with the PWR and BWR libraries in ORIGEN2, the generation of fission products having mass numbers from 105 to 130 and some actinides were overestimated by about 1.5 to 3.5 times

Extended burnup demonstration: reactor fuel program. Pre-irradiation characterization and summary of pre-program poolside examinations. Big Rock Point extended burnup fuel

International Nuclear Information System (INIS)

Exarhos, C.A.; Van Swam, L.F.; Wahlquist, F.P.

1981-12-01

This report is a resource document characterizing the 64 fuel rods being irradiated at the Big Rock Point reactor as part of the Extended Burnup Demonstration being sponsored jointly by the US Department of Energy, Consumers Power Company, Exxon Nuclear Company, and General Public Utilities. The program entails extending the exposure of standard BWR fuel to a discharge average of 38,000 MWD/MTU to demonstrate the feasibility of operating fuel of standard design to levels significantly above current limits. The fabrication characteristics of the Big Rock Point EBD fuel are presented along with measurement of rod length, rod diameter, pellet stack height, and fuel rod withdrawal force taken at poolside at burnups up to 26,200 MWD/MTU. A review of the fuel examination data indicates no performance characteristics which might restrict the continued irradiation of the fuel

Pre-Licensing Evaluation of Legacy SFR Metallic Fuel Data

Energy Technology Data Exchange (ETDEWEB)

Yacout, A. M. [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Billone, M. C. [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division

2016-09-16

The US sodium cooled fast reactor (SFR) metallic fuel performance data that are of interest to advanced fast reactors applications, can be attributed mostly to the Integral Fast Reactor (IFR) program between 1984 and 1994. Metallic fuel data collected prior to the IFR program were associated with types of fuel that are not of interest to future advanced reactors deployment (e.g., previous U-Fissium alloy fuel). The IFR fuels data were collected from irradiation of U-Zr based fuel alloy, with and without Pu additions, and clad in different types of steels, including HT9, D9, and 316 stainless-steel. Different types of data were generated during the program, and were based on the requirements associated with the DOE Advanced Liquid Metal Cooled Reactor (ALMR) program.

Fuel injection nozzle and method of manufacturing the same

Science.gov (United States)

Monaghan, James Christopher; Johnson, Thomas Edward; Ostebee, Heath Michael

2017-02-21

A fuel injection head for use in a fuel injection nozzle comprises a monolithic body portion comprising an upstream face, an opposite downstream face, and a peripheral wall extending therebetween. A plurality of pre-mix tubes are integrally formed with and extend axially through the body portion. Each of the pre-mix tubes comprises an inlet adjacent the upstream face, an outlet adjacent the downstream face, and a channel extending between the inlet and the outlet. Each pre-mix tube also includes at least one fuel injector that at least partially extends outward from an exterior surface of the pre-mix tube, wherein the fuel injector is integrally formed with the pre-mix tube and is configured to facilitate fuel flow between the body portion and the channel.

Monolithic fuel injector and related manufacturing method

Science.gov (United States)

Ziminsky, Willy Steve [Greenville, SC; Johnson, Thomas Edward [Greenville, SC; Lacy, Benjamin [Greenville, SC; York, William David [Greenville, SC; Stevenson, Christian Xavier [Greenville, SC

2012-05-22

A monolithic fuel injection head for a fuel nozzle includes a substantially hollow vesicle body formed with an upstream end face, a downstream end face and a peripheral wall extending therebetween, an internal baffle plate extending radially outwardly from a downstream end of the bore, terminating short of the peripheral wall, thereby defining upstream and downstream fuel plenums in the vesicle body, in fluid communication by way of a radial gap between the baffle plate and the peripheral wall. A plurality of integral pre-mix tubes extend axially through the upstream and downstream fuel plenums in the vesicle body and through the baffle plate, with at least one fuel injection hole extending between each of the pre-mix tubes and the upstream fuel plenum, thereby enabling fuel in the upstream plenum to be injected into the plurality of pre-mix tubes. The fuel injection head is formed by direct metal laser sintering.

GFR fuel and core pre-conceptual design studies

International Nuclear Information System (INIS)

Chauvin, N.; Ravenet, A.; Lorenzo, D.; Pelletier, M.; Escleine, J.M.; Munoz, I.; Bonnerot, J.M.; Malo, J.Y.; Garnier, J.C.; Bertrand, F.; Bosq, J.C.

2007-01-01

The revision of the GFR core design - plate type - has been undertaken since previous core presented at Global'05. The self-breeding searched for has been achieved with an optimized design ('12/06 E'). The higher core pressure drop was a matter of concern. First of all, the core coolability in natural circulation for pressurized conditions has been studied and preliminary plant transient calculations have been performed. The design and safety criteria are met but no more margin remains. The project is also addressing the feasibility and the design of the fuel S/A. The hexagonal shape together with the principle of closed S/A (wrapper tube) is kept. Ceramic plate type fuel element combines a high enough core power density (minimization of the Pu inventory) and plutonium and minor actinides recycling capabilities. Innovative for many aspects, the fuel element is central to the GFR feasibility. It is supported already by a significant R and D effort also applicable to a pin concept that is considered as the other fuel element of interest. This combination of fuel/core feasibility and performance analysis, safety dispositions and performances analysis will compose the 'GFR preliminary feasibility' which is a project milestone at the end of the year 2007. (authors)

LMFBR fuel analysis. Task A: Oxide fuel dynamics. Final report, October 1, 1976--September 30, 1977

International Nuclear Information System (INIS)

Dhir, V.K.; Doshi, J.; Frank, M.; Hauss, B.; Kastenberg, W.E.; Wong, K.

1977-10-01

The study presented deals with several areas of uncertainty in the analysis of the unprotected overpower transient for the Clinch River Breeder Reactor. These areas of uncertainty include the time, place, and mode of fuel pin failure; pre-failure fuel motion; fuel freezing, plugging, and plate-out following pin failure; and the potential for re-criticality. Internal molten fuel motion prior to pin failure was found to be sensitive to ramp rate and burnup. The strain-limit fuel failure criterion was found to be inappropriate for analysis based on existing data. The coupling of pre-transient- and transient-induced stresses tended to force the failure location towards the core midplane

Fuel cell design using a new heuristic method

International Nuclear Information System (INIS)

Perusquia, R.; Montes T, J. L.; Ortiz S, J. J.; Castillo M, A.

2014-10-01

In this paper a new method for the pre-design of a typical fuel cell with a structural array of 10 x 10 fuel elements for a BWR is presented. The method is based on principles of maximum dispersion and minimum peaks of local power within the array of fuel elements. The pre-design of the fuel cells is made by simulation in two dimensions (2-D) through the cells physics code CASMO-4. For this purpose of pre-design the search process is guided by an objective function which is a combination of the main neutronic parameters of the fuel cell. The results show that the method is a promising tool that could be used for the design of fuel cells for use in a nuclear plant BWR. (Author)

Ni/YSZ anode – Effect of pre-treatments on cell degradation and microstructures

DEFF Research Database (Denmark)

Hauch, Anne; Jørgensen, Peter Stanley; Brodersen, Karen

2011-01-01

,TPB) was decreased to ¼ or less for the pre-treated and fuel cell tested cells when compared with a non-pre-treated reference tested cell; all operated at the same fuel cell test conditions. Scanning electron microscopy and image analyses for the non-pre-treated reference tested cell and selected pre-treated cells...

Pre-conceptual core design of SCWR with annular fuel rods

Energy Technology Data Exchange (ETDEWEB)

Zhao, Chuanqi [Key Laboratory of Thermo-Fluid Science and Engineering of MOE, School of Energy and Power Engineering, Xi’an Jiaotong University, Xi’an, Shaanxi 710049 (China); School of Nuclear Science and Technology, Xi’an Jiaotong University, Xi’an, Shaanxi 710049 (China); Cao, Liangzhi, E-mail: caolz@mail.xjtu.edu.cn [Key Laboratory of Thermo-Fluid Science and Engineering of MOE, School of Energy and Power Engineering, Xi’an Jiaotong University, Xi’an, Shaanxi 710049 (China); School of Nuclear Science and Technology, Xi’an Jiaotong University, Xi’an, Shaanxi 710049 (China); Wu, Hongchun; Zheng, Youqi [School of Nuclear Science and Technology, Xi’an Jiaotong University, Xi’an, Shaanxi 710049 (China)

2014-02-15

Highlights: • Annular fuel with both internal and external cooling is used in supercritical light water reactor (SCWR). • The geometry of the annular fuel has been optimized to achieve better performance for the SCWR. • Based on the annular fuel assembly, an equilibrium core has been designed. • The results show that the equilibrium core has satisfied all the objectives and design criteria. - Abstract: The new design of supercritical light water reactor was proposed using annular fuel assemblies. Annular fuel consists of several concentric rings. Feed water flows through the center and outside of the fuel to give both internal and external cooling. Thanks to this feature, the fuel center temperature and the cladding temperature can be reduced and high power density can be achieved. The water flowing through the center also provides moderation, so there is no need for extra water rods in the assembly. The power distribution can be easily flattened by use of this design. The geometry of the annular fuel has been optimized to achieve better performance for the SCWR. There are 19 fuel pins in an assembly. Burnable poison is utilized to reduce the initial excess reactivity. The fuel reloading pattern and water flow scheme were optimized to achieve more uniform power distribution and lower cladding temperature. An equilibrium core has been designed and analyzed using three dimensional neutronics and thermal-hydraulics coupling calculations. The void reactivity, Doppler coefficient and cold shut down margin were calculated for safety consideration. The present results show that this concept is a promising design for the SCWR.

Pattern fuel assembly loading system

International Nuclear Information System (INIS)

Ahmed, H.J.; Gerkey, K.S.; Miller, T.W.; Wylie, M.E.

1986-01-01

This patent describes an interactive system for facilitating preloading of fuel rods into magazines, which comprises: an operator work station adapted for positioning between a supply of fuel rods of predetermined types, and the magazine defining grid locations for a predetermined fuel assembly; display means associated with the work station; scanner means associated with the work station and adapted for reading predetermined information accompanying the fuel rods; a rectangular frame adapted for attachment to one end of the fuel assembly loading magazine; prompter/detector means associated with the frame for detecting insertion of a fuel rod into the magazine; and processing means responsive to the scanner means and the sensing means for prompting the operator via the display means to pre-load the fuel rods into desired grid locations in the magazine. An apparatus is described for facilitating pre-loading of fuel rods in predetermined grid locations of a fuel assembly loading magazine, comprising: a rectangular frame adapted for attachment to one end of the fuel assembly loading magazine; and means associated with the frame for detecting insertion of fuel rods into the magazine

Modelling auto ignition of hydrogen in a jet ignition pre-chamber

Energy Technology Data Exchange (ETDEWEB)

Boretti, Alberto A. [School of Science and Engineering, University of Ballarat, PO Box 663, Ballarat, Victoria 3353 (Australia)

2010-04-15

Spark-less jet ignition pre-chambers are enablers of high efficiencies and load control by quantity of fuel injected when coupled with direct injection of main chamber fuel, thus permitting always lean burn bulk stratified combustion. Towards the end of the compression stroke, a small quantity of hydrogen is injected within the pre-chamber, where it mixes with the air entering from the main chamber. Combustion of the air and fuel mixture then starts within the pre-chamber because of the high temperature of the hot glow plug, and then jets of partially combusted hot gases enter the main chamber igniting there in the bulk, over multiple ignition points, lean stratified mixtures of air and fuel. The paper describes the operation of the spark-less jet ignition pre-chamber coupling CFD and CAE engine simulations to allow component selection and engine performance evaluation. (author)

Prescribed burning in ponderosa pine: fuel reductions and redistributing fuels near boles to prevent injury

Science.gov (United States)

Prescribed burning can be an effective tool for thinning forests and reducing fuels to lessen wildfire risks. However, prescribed burning sometimes fails to substantially reduce fuels and sometimes damages/kills valuable, large trees. This study compared fuel reductions between fall and spring pre...

Method for pre-heating lmfbr type reactors

International Nuclear Information System (INIS)

Yokozawa, Atsushi; Kataoka, Hajime.

1978-01-01

Purpose: To enable pre-heating for the inside of the reactor container and the inside of the coolant recycling system with no additional facilities. Method: The coolant recycling system is composed of a heat exchanger, a mechanical pump, a check valve, a flow meter or the like and it is connected in series by way of a pipe line to a reactor container. The mechanical pump is used as a gas recycling device upon pre-heating and it is designed so that a blower such as a fan can be replaced for the impeller of the pump. The inside of the reactor container and the inside of the coolant recycling system is at first filled with an inert gas such as for use with cover gas. Then, nuclear fuels are loaded to attain criticality. Simultaneously, the blower is started and the control rods are operated while cooling the nuclear fuel with the inert gas thus to obtain heat required for pre-heating the pipe line or the like from the nuclear fuels. After the completion of the pre-heating, the liquid metal is charged. (Ikeda, J.)

Fuel Flexible, Low Emission Catalytic Combustor for Opportunity Fuel Applications

Energy Technology Data Exchange (ETDEWEB)

Eteman, Shahrokh

2013-06-30

Limited fuel resources, increasing energy demand and stringent emission regulations are drivers to evaluate process off-gases or process waste streams as fuels for power generation. Often these process waste streams have low energy content and/or highly reactive components. Operability of low energy content fuels in gas turbines leads to issues such as unstable and incomplete combustion. On the other hand, fuels containing higher-order hydrocarbons lead to flashback and auto-ignition issues. Due to above reasons, these fuels cannot be used directly without modifications or efficiency penalties in gas turbine engines. To enable the use of these wide variety of fuels in gas turbine engines a rich catalytic lean burn (RCL®) combustion system was developed and tested in a subscale high pressure (10 atm.) rig. The RCL® injector provided stability and extended turndown to low Btu fuels due to catalytic pre-reaction. Previous work has shown promise with fuels such as blast furnace gas (BFG) with LHV of 85 Btu/ft3 successfully combusted. This program extends on this work by further modifying the combustor to achieve greater catalytic stability enhancement. Fuels containing low energy content such as weak natural gas with a Lower Heating Value (LHV) of 6.5 MJ/m3 (180 Btu/ft3 to natural gas fuels containing higher hydrocarbon (e.g ethane) with LHV of 37.6 MJ/m3 (1010 Btu/ft3) were demonstrated with improved combustion stability; an extended turndown (defined as the difference between catalytic and non-catalytic lean blow out) of greater than 250oF was achieved with CO and NOx emissions lower than 5 ppm corrected to 15% O2. In addition, for highly reactive fuels the catalytic region preferentially pre-reacted the higher order hydrocarbons with no events of flashback or auto-ignition allowing a stable and safe operation with low NOx and CO emissions.

Nuclear fuel financing

International Nuclear Information System (INIS)

Lurf, G.

1975-01-01

Fuel financing is only at its beginning. A logical way of developing financing model is a step by step method starting with the financing of pre-payments. The second step will be financing of natural uranium and enrichment services to the point where the finished fuel elements are delivered to the reactor operator. The third step should be the financing of fuel elements during the time the elements are inserted in the reactor. (orig.) [de

Pre-Combustion Capture of CO2 in IGCC Plants

Energy Technology Data Exchange (ETDEWEB)

NONE

2011-12-15

Pre-combustion capture involves reacting a fuel with oxygen or air and/or steam to give mainly a 'synthesis gas (syngas)' or 'fuel gas' composed of carbon monoxide and hydrogen. The carbon monoxide is reacted with steam in a catalytic reactor, called a shift converter, to produce CO2 and more hydrogen. CO2 is then separated, usually by a physical or chemical absorption process, resulting in a hydrogen-rich fuel which can be used in many applications, such as boilers, furnaces, gas turbines, engines and fuel cells. Pre-combustion capture is suitable for use in integrated gasification combined cycle (IGCC) plants especially since the CO2 partial pressures in the fuel gas are higher than in the flue gas. After the introduction there follows a short discussion of the water-gas shift (WGS) reaction. This is followed by chapters on the means of CO2 capture by physical and chemical solvents, solid sorbents, and membranes. The results and conclusions of techno-economic studies are introduced followed by a look at some of the pilot and demonstration plants relevant to pre-combustion capture in IGCC plants.

Acid pre-hydrolysis of biomass as a preparation process for its utilization as thermoelectric power plants fuel; Pre-hidrolise acida da biomassa como preparacao de combustivel para termoeletrica

Energy Technology Data Exchange (ETDEWEB)

Pinatti, D G; Resende, R L [Fundacao de Tecnologia Industrial (FTI), Lorena, SP (Brazil)

1991-12-31

It is described a process of production of celulignin from biomass through acid pre-hydrolysis in continuous reactor made of advanced materials such as niobium, titanium and monel. The celulignin is a fuel of 28.50 MJ/kg of heating power. The utilization of this technology together with eucalyptus reforestation by vegetative propagation and high efficiency thermoelectric plant (triple cycle of steam turbine, gas turbine and MHD electrical generation) allow electric power production with competitive cost when compared to hydroelectric power. (author). 1 ref. 5 figs., 2 tabs

Mineralogic and petrologic investigation of pre-test core samples from the spent fuel test-climax

International Nuclear Information System (INIS)

Ryerson, F.J.; Qualheim, B.J.

1983-12-01

Pre-test samples obtained from just inside the perimeter of the canister emplacement holes of the Spent Fuel Test-Climax have been characterized by petrographic and microanalytical techniques. The primary quartz monzonite has undergone various degrees of hydrothermal alteration as a result of natural processes. Alteration is most apparent on primary plagioclase and biotite. The most common secondary phases on plagioclase are muscovite and calcite, while the most common secondary phases on biotite are epidote and chlorite. The major alteration zones encountered are localized along filled fractures, i.e. veins. The thickness and mineralogy of the alteration zones can be correlated with the vein mineralogy, becoming wider and more complex mineralogically when the veins contain calcite. 7 references, 10 figures, 4 tables

Fuel flexibility within a carbon limited energy world

Energy Technology Data Exchange (ETDEWEB)

Jones, R.M.; Raddings, T.; Scholz, M. [GE Energy (United States)

2007-07-01

This paper focuses on technical aspects of Integrated Gasification Combined Cycles (IGCC) from a coal, pre-combustion perspective, now and towards the future, including gasification and hydrogen gas turbines. The advantages of gasification and pre-combustion fuel clean-up range from the potential to utilize various low cost feedstock, which can be converted into synthetic fuels, to providing a viable and secure alternative to natural gas. GE has delivered over 650 licensed gasification facilities operational in the field, 12 with solid feedstock and 25 utilizing shift reaction for hydrogen production and CO{sub 2} capture. The process for pre-combustion de-carbonisation of natural gas or syngas derived from coals will result in gas turbine fuels that consist of 90% or higher hydrogen content fuel. Over 25 GE heavy-duty gas turbines are operating presently, on a large variation of syngas fuels, ranging from B and E to F-class technologies. 7 refs., 15 figs.

Combustor with two stage primary fuel tube with concentric members and flow regulating

Science.gov (United States)

Parker, David Marchant; Whidden, Graydon Lane; Zolyomi, Wendel

1999-01-01

A combustor for a gas turbine having a centrally located fuel nozzle and inner, middle and outer concentric cylindrical liners, the inner liner enclosing a primary combustion zone. The combustor has an air inlet that forms two passages for pre-mixing primary fuel and air to be supplied to the primary combustion zone. Each of the pre-mixing passages has a circumferential array of swirl vanes. A plurality of primary fuel tube assemblies extend through both pre-mixing passages, with each primary fuel tube assembly located between a pair of swirl vanes. Each primary fuel tube assembly is comprised of two tubular members. The first member supplies fuel to the first pre-mixing passage, while the second member, which extends through the first member, supplies fuel to the second pre-mixing passage. An annular fuel manifold is divided into first and second chambers by a circumferentially extending baffle. The proximal end of the first member is attached to the manifold itself while the proximal end of the second member is attached to the baffle. The distal end of the first member is attached directly to the second member at around its mid-point. The inlets of the first and second members are in flow communication with the first and second manifold chambers, respectively. Control valves separately regulate the flow of fuel to the two chambers and, therefore, to the two members of the fuel tube assemblies, thereby allowing the flow of fuel to the first and second pre-mixing passages to be separately controlled.

A study on the safety of spent fuel management. A scenario study on spent fuel management

Energy Technology Data Exchange (ETDEWEB)

Chun, Kwan Sik; Park, Hyun Soo; Ahn, Jin Soo; Hwang, Joo Ho; Choi, Jong Won; Kim, Yeon Soo; Park, Ju Hwan; Chung, Choong Hwan [Korea Atomic Energy Research Inst., Daeduk (Korea, Republic of)

1992-03-01

In order to produce data applicable for the long-term policy making of spent fuel management and to suggest a basic scenario suitable to domestic situation, the pre-conceptual design of reference disposal facilities for the spent fuel and the vitrified high level radioactive waste from its reprocessing, has been performed. From the results of the pre-conceptual study, further research and development areas to accumulate the disposal technology are suggested. In addition, the physico-chemical properties and functional characteristics of domestic bentonite are analyzed to assess its applicability as a buffer material which would play a major role for the safe disposal of highly active waste including spent fuels. (Author).

Coal Integrated Gasification Fuel Cell System Study

Energy Technology Data Exchange (ETDEWEB)

Gregory Wotzak; Chellappa Balan; Faress Rahman; Nguyen Minh

2003-08-01

The pre-baseline configuration for an Integrated Gasification Fuel Cell (IGFC) system has been developed. This case uses current gasification, clean-up, gas turbine, and bottoming cycle technologies together with projected large planar Solid Oxide Fuel Cell (SOFC) technology. This pre-baseline case will be used as a basis for identifying the critical factors impacting system performance and the major technical challenges in implementing such systems. Top-level system requirements were used as the criteria to evaluate and down select alternative sub-systems. The top choice subsystems were subsequently integrated to form the pre-baseline case. The down-selected pre-baseline case includes a British Gas Lurgi (BGL) gasification and cleanup sub-system integrated with a GE Power Systems 6FA+e gas turbine and the Hybrid Power Generation Systems planar Solid Oxide Fuel Cell (SOFC) sub-system. The overall efficiency of this system is estimated to be 43.0%. The system efficiency of the pre-baseline system provides a benchmark level for further optimization efforts in this program.

Catalysis in high-temperature fuel cells.

Science.gov (United States)

Föger, K; Ahmed, K

2005-02-17

Catalysis plays a critical role in solid oxide fuel cell systems. The electrochemical reactions within the cell--oxygen dissociation on the cathode and electrochemical fuel combustion on the anode--are catalytic reactions. The fuels used in high-temperature fuel cells, for example, natural gas, propane, or liquid hydrocarbons, need to be preprocessed to a form suitable for conversion on the anode-sulfur removal and pre-reforming. The unconverted fuel (economic fuel utilization around 85%) is commonly combusted using a catalytic burner. Ceramic Fuel Cells Ltd. has developed anodes that in addition to having electrochemical activity also are reactive for internal steam reforming of methane. This can simplify fuel preprocessing, but its main advantage is thermal management of the fuel cell stack by endothermic heat removal. Using this approach, the objective of fuel preprocessing is to produce a methane-rich fuel stream but with all higher hydrocarbons removed. Sulfur removal can be achieved by absorption or hydro-desulfurization (HDS). Depending on the system configuration, hydrogen is also required for start-up and shutdown. Reactor operating parameters are strongly tied to fuel cell operational regimes, thus often limiting optimization of the catalytic reactors. In this paper we discuss operation of an authothermal reforming reactor for hydrogen generation for HDS and start-up/shutdown, and development of a pre-reformer for converting propane to a methane-rich fuel stream.

Technical report: fabrication of PWR type rodlet fuel

International Nuclear Information System (INIS)

Yanagisawa, Kazuaki; Uno, Hisao; Sasajima, Hideo

1990-06-01

With respect to the simulated reactivity initiated accident (RIA) experiments with pre-irradiated LWR type fuel rods at nuclear safety research reactor (NSRR), there were principally three technical difficulties which should be overcome: (1) Fabrication of the rodlet fuel; Fuel rods from the commercial power reactors had an active column length by 3.6m. To utilize this for NSRR pulse experiment, rodlet fuel having an active column length by 0.12m (reduced to one thirtieth) is requested to fabricate without changing the inside fuel conditions. (2) Development of in-core instrumentations: During pre-irradiation stages, a long-sized fuel rod had dimensional changes by waterside corrosion, bowing, creep down and so on. The fuel also had greater amount of radioactive fission products. This condition is significant to in-core instrumentations to be attached to the fuel rods. Well characterized data to be obtained from these, however, are quite necessary and important from research point of view. Remote handling techniques to attach the rod pressure sensor, the cladding extensometer, the fuel extensometer, and the cladding surface thermocouple to pre-irradiated fuel rods are, therefore, requested to develop. (3) Installation of PIE equipments for pulsed rodlet fuels: PIE on the pulsed rodlet fuels are necessary to better understanding the fuel performance detaily. Equipments which can easily detect the data related to PCMI type fuel failure are matter of concern. Since 1986, the technical difficulties have been tried to overcome by all staffs belonging to Reactivity Accident Laboratory, NSRR Operation Division, Department of Reactor Fuel Examination and Hot Laboratory. This report describes the technical achievements obtained through four years work. (author)

BWR spent fuel storage cask performance test. Volume 2. Pre- and post-test decay heat, heat transfer, and shielding analyses

International Nuclear Information System (INIS)

Wiles, L.E.; Lombardo, N.J.; Heeb, C.M.; Jenquin, U.P.; Michener, T.E.; Wheeler, C.L.; Creer, J.M.; McCann, R.A.

1986-06-01

This report describes the decay heat, heat transfer, and shielding analyses conducted in support of performance testing of a Ridhihalgh, Eggers and Associates REA 2033 boiling water reactor (BWR) spent fuel storage cask. The cask testing program was conducted for the US Department of Energy (DOE) Commercial Spent Fuel Management Program by the Pacific Northwest Laboratory (PNL) and by General Electric at the latters' Morris Operation (GE-MO) as reported in Volume I. The analyses effort consisted of performing pretest calculations to (1) select spent fuel for the test; (2) symmetrically load the spent fuel assemblies in the cask to ensure lateral symmetry of decay heat generation rates; (3) optimally locate temperature and dose rate instrumentation in the cask and spent fuel assemblies; and (4) evaluate the ORIGEN2 (decay heat), HYDRA and COBRA-SFS (heat transfer), and QAD and DOT (shielding) computer codes. The emphasis of this second volume is on the comparison of code predictions to experimental test data in support of the code evaluation process. Code evaluations were accomplished by comparing pretest (actually pre-look, since some predictions were not completed until testing was in progress) predictions with experimental cask testing data reported in Volume I. No attempt was made in this study to compare the two heat transfer codes because results of other evaluations have not been completed, and a comparison based on one data set may lead to erroneous conclusions

Behavior of metallic fuel in treat transient overpower tests

International Nuclear Information System (INIS)

Bauer, T.H.; Wright, A.E.; Robinson, W.R.; Klickman, A.E.

1988-01-01

Results and analyses are reported for TREAT in-pile transient overpower tests of margin to cladding failure and pre-failure axial expansion of metallic fuel. In all cases the power rise was exponential on an 8 s period until either incipient or actual cladding failure was achieved. Test fuel included EBR-II driver fuel and ternary alloy, the reference fuel of the Intergral Fast Reactor concept. Test pin burnup spanned the widest range available. The nature of the observed cladding failure and resultant fuel dispersals is described. Simple models are presented which describe observed cladding failures and pre-failure axial expansions yet are general enough to apply to all metal fuel types

Irradiation behavior of uranium-molybdenum dispersion fuel: Fuel performance data from RERTR-1 and RERTR-2

International Nuclear Information System (INIS)

Meyer, M.K.; Clark, C.R.; Hayes, S.L.; Strain, R.V.; Hofman, G.L.; Snelgrove, J.L.; Park, J.M.; Kim, K.H.

1999-01-01

This paper presents quantitative data on the irradiation behavior of uranium-molybdenum fuels from the low temperature RERTR-1 and -2 experiments. Fuel swelling measurements of U-Mo fuels at ∼40% and ∼70% burnup are presented. The rate of fuel-matrix interaction layer growth is estimated. Microstructures of fuel in the pre- and postirradiation condition were compared. Based on these data, a qualitative picture of the evolution of the U-Mo fuel microstructure during irradiation has been developed. Estimates of uranium-molybdenum fuel swelling and fuel-matrix interaction under high-power research reactor operating conditions are presented. (author)

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

Energy Technology Data Exchange (ETDEWEB)

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

2014-07-01

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

Thermodynamic Analysis of an Integrated Solid Oxide Fuel Cell Cycle with a Rankine Cycle

DEFF Research Database (Denmark)

Rokni, Masoud

2010-01-01

Hybrid systems consisting of Solid Oxide Fuel Cells (SOFC) on the top of a Steam Turbine (ST) are investigated. The plants are fired by natural gas (NG). A desulfurization reactor removes the sulfur content in the fuel while a pre-reformer breaks down the heavier hydrocarbons. The pre-treated fuel......% are achieved which is considerably higher than the conventional Combined Cycles (CC). Both ASR (Adiabatic Steam Reformer) and CPO (Catalytic Partial Oxidation) fuel pre-reformer reactors are considered in this investigation....

Assessment of oxy-fuel, pre- and post-combustion-based carbon capture for future IGCC plants

International Nuclear Information System (INIS)

Kunze, Christian; Spliethoff, Hartmut

2012-01-01

Highlights: ► Hot gas cleanup is a highly favorable technology for all selected IGCC concepts. ► Proposed high pressure IGCC with membrane reactor enables direct CO 2 condensation. ► IGCC with OTM and carbonate looping enable significant synergy effects. ► Combining IGCC and oxy-fuel is technically challenging but energetically favorable. ► All selected IGCC concepts are able to realize CO 2 capture rates up to 99%. -- Abstract: Environmental damage due to the emission of greenhouse gases from conventional coal-based power plants is a growing concern. Various carbon capture strategies to minimize CO 2 emissions are currently being investigated. Unfortunately, the efficiency drop due to de-carbonization is still significant and the capture rate is limited. Therefore three future hard coal IGCC concepts are assessed here, applying emerging technologies and various carbon capture approaches. The advanced pre-combustion capture concept is based on hot gas clean-up, membrane-enhanced CO conversion and direct CO 2 condensation. The concept reached a net efficiency of 45.1% (LHV), representing an improvement of 6.46% compared to the conventional IGCC base case. The second IGCC concept, based on post-combustion capture via calcination–carbonation loops, hot gas clean-up and oxygen membranes, showed a net efficiency of 45.87% (LHV). The third IGCC concept applies hot gas clean-up and combustion of the unconverted fuel gas using pure oxygen. The oxygen is supplied by an integrated oxygen membrane. The combination of IGCC and oxy-fuel process reached a net efficiency of 45.74% (LHV). In addition to their increased efficiency, all of the concepts showed significantly improved carbon capture rates up to 99%, resulting in virtually carbon-free fossil power plants.

Flame holding tolerant fuel and air premixer for a gas turbine combustor

Science.gov (United States)

York, William David; Johnson, Thomas Edward; Ziminsky, Willy Steve

2012-11-20

A fuel nozzle with active cooling is provided. It includes an outer peripheral wall, a nozzle center body concentrically disposed within the outer wall in a fuel and air pre-mixture. The fuel and air pre-mixture includes an air inlet, a fuel inlet and a premixing passage defined between the outer wall in the center body. A gas fuel flow passage is provided. A first cooling passage is included within the center body in a second cooling passage is defined between the center body and the outer wall.

Identification of accelerants, fuels and post-combustion residues using a colorimetric sensor array.

Science.gov (United States)

Li, Zheng; Jang, Minseok; Askim, Jon R; Suslick, Kenneth S

2015-09-07

A linear (1 × 36) colorimetric sensor array has been integrated with a pre-oxidation technique for detection and identification of a variety of fuels and post-combustion residues. The pre-oxidation method permits the conversion of fuel vapor into more detectable species and therefore greatly enhances the sensitivity of the sensor array. The pre-oxidation technique used a packed tube of chromic acid on an oxide support and was optimized in terms of the support and concentration. Excellent batch to batch reproducibility was observed for preparation and use of the disposable pre-oxidation tubes. Twenty automotive fuels including gasolines and diesel from five gasoline retailers were individually identifiable with no confusions or misclassifications in quintuplicate trials. Limits of detection were at sub-ppm concentrations for gasoline and diesel fuels. In addition, burning tests were performed on commonly used fire accelerants, and clear differentiation was achieved among both the fuels themselves and their volatile residues after burning.

Increasing TRIGA fuel lifetime with 12 wt.% U TRIGA fuel

Energy Technology Data Exchange (ETDEWEB)

Naughton, W F; Cenko, M J; Levine, S H; Witzig, W F [Pennsylvania State University (United States)

1974-07-01

In-core fuel management studies have been performed for the Penn State Breazeale Reactor (PSBR) wherein 12 wt % U fuel elements are used to replace the standard 8.5 wt % U TRIGA fuel. The core configuration used to develop a calculational model was a 90-element hexagonal array, which is representative of the PSBR core, and consists of five hexagonal rings surrounding a central thimble containing water. The technique employed for refueling the core fully loaded with 8.5 wt % U fuel involves replacing 8.5 wt % U fuel with 12 wt % U fuel using an in-out reloading scheme. A batch reload consists of 6 new 12 wt % U fuel elements. Placing the 12 wt % U fuel in the B ring produces fuel temperatures ({approx}450 {sup o}C) that are well below the 800{sup o}C maximum limitation when the PSBR is operating at its maximum allowed power of 1 Megawatt. The advantages of using new 12 wt % U fuel to replace the burned up 8.5 wt % U fuel in the B ring over refueling strictly with 8.5 wt % U-Zr TRIGA fuel are clearly delineated in Table 1 where cost calculations used the General Atomic pre-1972 prices for TRIGA fuel, i.e., $1500 and $1650 for an 8.5 and 12 wt % U fuel element, respectively. Experimental results obtained to date utilizing the 12 wt % U fuel elements agree with the computed results. (author)

Viability assessment of regional biomass pre-processing center based bioethanol value chains

Science.gov (United States)

Carolan, Joseph E.

Petroleum accounts for 94% of all liquid fuels and 36% of the total of all energy consumed in the United States. Petroleum dependence is problematic because global petroleum reserves are estimated to last only for 40 to 60 years at current consumption rates; global supplies are often located in politically unstable or unfriendly regions; and fossil fuels have negative environmental footprints. Domestic policies have aimed at promoting alternative, renewable liquid fuels, specifically bio-fuels derived from organic matter. Cellulosic bio-ethanol is one promising alternative fuel that has featured prominently in federal bio-fuel mandates under the Energy Independence and Security Act, 2007. However, the cellulosic bio-ethanol industry faces several technical, physical and industrial organization challenges. This dissertation examines the concept of a network of regional biomass pre-treatment centers (RBPC) that form an extended biomass supply chain feeding into a simplified biorefinery as a way to overcome these challenges. The analyses conducted address the structural and transactional issues facing bio-ethanol value chain establishment; the technical and financial feasibility of a stand alone pre-treatment center (RBPC); the impact of distributed pre-treatment on biomass transport costs; a comparative systems cost evaluation of the performance of the RBPC chain versus a fully integrated biorefinery (gIBRh), followed by application of the analytical framework to three case study regions.

Preparation of the proton exchange membranes for fuel cell under pre-irradiation induced grafting method

International Nuclear Information System (INIS)

Li Jingye; Muto, F.; Matsuura, A.; Kakiji, T.; Miura, T.; Oshima, A.; Washio, M.; Katsumura, Y.

2006-01-01

Proton exchange membranes (PEMs) were prepared via pre-irradiation induced grafting of styrene or styrene/divinylbenzene (S/DVB) into the crosslinked polytetrafluoroethylene (RX-PTFE) films with thickness around 10 m and then sulfonated by chlorosulfonic acid. The membrane electrode assembles (MEAs) based on these PEMs with ion exchange capacity (IEC) values around 2meq/g were prepared by hot-press with Nafion dispersion coated on the surfaces of the membranes and electrodes. And the MEA based on the Nafion 112 membrane was also prepared under same procedure as a comparison. The performances of the MEAs in single fuel cell were tested under different working temperatures and humidification conditions. The performance of the synthesized PEMs showed better results than that of Nafion 112 membrane under low humidification at 80 degree C. The electrochemical impedance spectra (EIS) were taken with the direct current density of 0.5A/cm 2 and the resulted curves in Nyqvist representation obeyed the half circle pattern. (authors)

MODELING OF THE FUNCTIONING UNITS OF FUEL SYSTEM OF GAS TURBINE ENGINE AIRCRAFT IN VIEW OF AVIATION FUEL QUALITY CHANGES

OpenAIRE

I. I. Zavyalik; V. S. Oleshko; V. M. Samoylenko; E. V. Fetisov

2016-01-01

The article describes the developed modeling system in MATLAB Simulink which allows to simulate, explore and pre- dict the technical condition of the units of the aircraft gas turbine engine fuel system depending on aviation fuel quality changes.

Proton exchange membrane fuel cells modeling

CERN Document Server

Gao, Fengge; Miraoui, Abdellatif

2013-01-01

The fuel cell is a potential candidate for energy storage and conversion in our future energy mix. It is able to directly convert the chemical energy stored in fuel (e.g. hydrogen) into electricity, without undergoing different intermediary conversion steps. In the field of mobile and stationary applications, it is considered to be one of the future energy solutions.Among the different fuel cell types, the proton exchange membrane (PEM) fuel cell has shown great potential in mobile applications, due to its low operating temperature, solid-state electrolyte and compactness.This book pre

MODELING OF THE FUNCTIONING UNITS OF FUEL SYSTEM OF GAS TURBINE ENGINE AIRCRAFT IN VIEW OF AVIATION FUEL QUALITY CHANGES

Directory of Open Access Journals (Sweden)

I. I. Zavyalik

2016-01-01

Full Text Available The article describes the developed modeling system in MATLAB Simulink which allows to simulate, explore and pre- dict the technical condition of the units of the aircraft gas turbine engine fuel system depending on aviation fuel quality changes.

Catalytic processing of high-sulfur fuels for distributed hydrogen production

Energy Technology Data Exchange (ETDEWEB)

Muradov, Nazim; Ramasamy, Karthik; Huang, Cunping; T-Raissi, Ali [Central Florida Univ., FL (United States)

2010-07-01

In this work, the development of a new on-demand hydrogen production technology is reported. In this process, a liquid hydrocarbon fuel (e.g., high-S diesel) is first catalytically pre-reformed to shorter chain gaseous hydrocarbons (predominantly, C{sub 1}-C{sub 3}) before being directed to the steam reformer, where it is converted to syngas and then to high-purity hydrogen. In the pre-reformer, most sulfurous species present in the fuel are catalytically converted to H{sub 2}S. In the desulfurization unit, H{sub 2}S is scrubbed and converted to H{sub 2} and elemental sulfur. Desulfurization of the pre-reformate gas is carried out in a special regenerative redox system, which includes Fe(II)/Fe(III)-containing aqueous phase scrubber coupled with an electrolyzer. The integrated pre-reformer/scrubber/electrolyzer unit operated successfully on high-S diesel fuel for more than 100 hours meeting the required desulfurization target of >95 % sulfur removal. (orig.)

Thermodynamic analysis of an integrated solid oxide fuel cell cycle with a rankine cycle

International Nuclear Information System (INIS)

Rokni, Masoud

2010-01-01

Hybrid systems consisting of solid oxide fuel cells (SOFC) on the top of a steam turbine (ST) are investigated. The plants are fired by natural gas (NG). A desulfurization reactor removes the sulfur content in the fuel while a pre-reformer breaks down the heavier hydro-carbons. The pre-treated fuel enters then into the anode side of the SOFC. The remaining fuels after the SOFC stacks enter a burner for further burning. The off-gases are then used to produce steam for a Rankine cycle in a heat recovery steam generator (HRSG). Different system setups are suggested. Cyclic efficiencies up to 67% are achieved which is considerably higher than the conventional combined cycles (CC). Both adiabatic steam reformer (ASR) and catalytic partial oxidation (CPO) fuel pre-reformer reactors are considered in this investigation.

40 CFR 80.603 - What are the pre-compliance reporting requirements for NRLM diesel fuel?

Science.gov (United States)

2010-07-01

... requirements for NRLM diesel fuel? 80.603 Section 80.603 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) REGULATION OF FUELS AND FUEL ADDITIVES Motor Vehicle Diesel Fuel; Nonroad, Locomotive, and Marine Diesel Fuel; and ECA Marine Fuel Recordkeeping and Reporting...

Development of lean burn gas engines using pilot fuel for ignition source; Developpement d'un moteur a gaz avec pre-injection de carburant pour la source d'allumage

Energy Technology Data Exchange (ETDEWEB)

Sakonji, T.; Saito, H.; Sakurai, T. [Tokyo Gas Co., Ltd. (Japan); Hirashima, T.; Kanno, K. [Nissan Diesel Motor Co., Ltd. (Japan)

2000-07-01

A development was conducted to investigate the performance of an open chamber gas engine with pilot fuel for ignition source. Experiments were conducted by using a gas engine equipped with a common-rail injection system. Main gas fuel is supplied to the engine cylinder, and then a small quantity of diesel fuel (approximately 1 % of total fuel energy input) was injected into the main chamber for ignition. The single cylinder prototype gas engine has demonstrated superior performance, such as, a shaft-end thermal efficiency of 36.7% with NO{sub x} level of 0.4 g/kW-h, which equals those of conventional spark ignited pre-chamber lean burn gas engines. For the next step, the multi-cylinder gas engine has been developed. That has 138 mm bore, 142 mm stroke, V8 configuration and 229 kW engine output 1500 rpm. This engine can also run with only diesel fuel for Standby-Power-Concurrent Co-generation. (authors)

Nanoindentation measurements of the mechanical properties of zirconium matrix and hydrides in unirradiated pre-hydrided nuclear fuel cladding

International Nuclear Information System (INIS)

Rico, A.; Martin-Rengel, M.A.; Ruiz-Hervias, J.; Rodriguez, J.; Gomez-Sanchez, F.J.

2014-01-01

It is well known that the mechanical properties of the nuclear fuel cladding may be affected by the presence of hydrides. The average mechanical properties of hydrided cladding have been extensively investigated from a macroscopic point of view. In addition, the mechanical and fracture properties of bulk hydride samples fabricated from zirconium plates have also been reported. In this paper, Young’s modulus, hardness and yield stress are measured for each phase, namely zirconium hydrides and matrix, of pre-hydrided nuclear fuel cladding. To this end, nanoindentation tests were performed on ZIRLO samples in as-received state, on a hydride blister and in samples with 150 and 1200 ppm of hydrogen homogeneously distributed along the hoop direction of the cladding. The results show that the measured mechanical properties of the zirconium hydrides and ZIRLO matrix (Young’s modulus, hardness and yield stress) are rather similar. From the experimental data, the hydride volume fraction in the cladding samples with 150 and 1200 ppm was estimated and the average mechanical properties were calculated by means of the rule of mixtures. These values were compared with those obtained from ring compression tests. Good agreement between the results obtained by both methods was found

Analysis of irradiation temperature in fuel rods of OGL-1 fuel assembly

International Nuclear Information System (INIS)

Fukuda, Kousaku; Kobayashi, Fumiaki; Minato, Kazuo; Ikawa, Katsuichi; Iwamoto, Kazumi

1984-10-01

Irradiation temperature in the fuel rods of 5th OGL-1 fuel assembly was analysed by the system composed by STPDSP2 and TRUMP codes. As the measured input-data, following parameters were allowed for; circumferential heating distribution around the fuel rod, which was measured in the JMTR critical assembly, axial heating distribution through the fuel rod, ratio of peak heatings of three fuel rods, and pre- and post-irradiation outer radii of the fuel compacts and inner radii of the graphite sleeves, which had been measured in PIE of the 5th OGL-1 fuel assembly. In computation the axial distributions of helium coolant temperature through the fuel rod and the heating value of each fuel rod were, firstly, calculated as input data for TRUMP. The TRUMP calculation yielded the temperatures which were fitted in those measured by all of the thermo-couples installed in the fuel rods, by adjusting only the value of the surface heat transfer coefficient, and consequently, the temperatures in all portions of the fuel rod were obtained. The apparent heat transfer coefficient changed to 60% of the initial values in the middle period of irradiation. For this reduction it was deduced that shoot had covered the surface of the fuel rod during irradiation, which was confirmed in PIE. Beside it, several things were found in this analysis. (author)

Pre-Shipment Preparations at the Savannah River Site

International Nuclear Information System (INIS)

Thomas, J.E.

2000-01-01

This paper will provide a detailed description of each of the pre-shipment process steps WSRC performs to produce the technical basis for approving the receipt and storage of spent nuclear fuel at the Savannah River Site. It is intended to be a guide to reactor operators who plan on returning ''U.S. origin'' SNF and to emphasize the need for accurate and timely completion of pre-shipment activities

MaxiFuels. Final report; Maxi-Fuels. Afslutningsrapport

Energy Technology Data Exchange (ETDEWEB)

2008-07-01

The MaxiFuel pilot plant opened September 2006 with a view to testing and developing a competitive integrated concept for 2nd generation bioethanol production from lignocellulosic biomass such as straw. This makes the raw material cheaper than crops cultivated for energy production purposes only, and the bioethanol production will not compete with production of food. The MaxiFuels concept is a patented technology which has proven in lab-scale to have the potential of producing bioethanol from residual biomass for a lower price than other existing 2nd generation bioethanol concepts. Lately a suitable pre-treatment process, Wet Explosion, has been developed, and enzymes and C6 fermentation based on yeast have been tested and further developed on pre-treated straw. Furthermore a special micro organism has been isolated, genetically engineered and tested on the pre-treated biomass. The micro organism converts C5 sugars to ethanol. Finally an attempt has been made to produce biogas from the remaining organic material, which can't be fermented to ethanol. All the abovementioned processes have been developed in lab-scale. The operation of these processes at the same time in one concept in pilot scale makes it possible to evaluate the concept's productivity in full-scale. The data of the pilot plant operation have been used for the set-up of an economical model of the whole concept. Based on this model a full-scale plant has been designed and a business plan for the implementation of this step has been elaborated. (BA)

Roles of programmable logic controllers in fuel reprocessing plants

International Nuclear Information System (INIS)

Mishra, Hrishikesh; Balakrishnan, V.P.; Pandya, G.J.

1999-01-01

Fuel charging facility is another application of Programmable Logic Controllers (PLC) in fuel reprocessing plants, that involves automatic operation of fuel cask dolly, charging motor, pneumatic doors, clutches, clamps, stepper motors and rod pushers in a pre-determined sequence. Block diagram of ACF system is given for underlining the scope of control and interlocks requirements involved for automation of the fuel charging system has been provided for the purpose at KARP Plant, Kalpakkam

Fuel cell design using a new heuristic method; Diseno de celdas de combustible mediante un nuevo metodo heuristico

Energy Technology Data Exchange (ETDEWEB)

Perusquia, R.; Montes T, J. L.; Ortiz S, J. J.; Castillo M, A., E-mail: joseluis.montes@inin.gob.mx [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

2014-10-15

In this paper a new method for the pre-design of a typical fuel cell with a structural array of 10 x 10 fuel elements for a BWR is presented. The method is based on principles of maximum dispersion and minimum peaks of local power within the array of fuel elements. The pre-design of the fuel cells is made by simulation in two dimensions (2-D) through the cells physics code CASMO-4. For this purpose of pre-design the search process is guided by an objective function which is a combination of the main neutronic parameters of the fuel cell. The results show that the method is a promising tool that could be used for the design of fuel cells for use in a nuclear plant BWR. (Author)

High-performance oxygen reduction catalysts in both alkaline and acidic fuel cells based on pre-treating carbon material and iron precursor

Energy Technology Data Exchange (ETDEWEB)

Song, Ping; Barkholtz, Heather M.; Wang, Ying; Xu, Weilin; Liu, Dijia; Zhuang, Lin

2017-12-01

We demonstrate a new and simple method for pre-treating the carbon material and iron precursor to prepare oxygen reduction reaction (ORR) catalysts, which can produce super-high performance and stability in alkaline solution, with high performance in acid solution. This strategy using cheap materials is simply controllable. Moreover, it has achieved smaller uniform nanoparticles to exhibit high stability, and the synergetic effect of Fe and N offered much higher performance in ORR than commercial Pt/C, with high maximum power density in alkaline and acid fuel cell test. So it can make this kind of catalysts be the most promising alternatives of Pt-based catalysts with best performance/price.

Assessment of core characteristics during transition from 37-element fuel to CANFLEX-NU fuel in CANDU 6

International Nuclear Information System (INIS)

Jeong, Chang Joon; Suk, Ho Chun

2002-01-01

A transition from 37-element natural uranium fuel to CANFLEX-NU fuel has been modeled in a 1200-day time-dependent fuel management simulation for a CANDU 6 reactor. The simulation was divided into three parts. The pre-transition period extended from 0 to 300 FPD, in which the reactor was fuelled only with standard 37-element fuel bundles. In the transition period, refueling took place only with the CANFLEX-NU fuel bundle. The transition stage lasted from 300 to 920 FPD, at which point all of the 37-element fuel in the core had been replaced by CANFLEX-NU fuel bundle. In the post-transition phase, refueling continued with CANFLEX-NU fuel until 1200 FPD, to arrive at estimate of the equilibrium core characteristics with CANFLEX-NU fuel. Simulation results show that the CANFLEX-NU fuel bundle has a operational compatibility with the CANDU 6 reactor during the transition core, and also show that the transition core from 37-element natural uranium fuel to CANFLEX-NU can be operated without violating any license limit of the CANDU 6 reactor

Legislation of Renewable Energy Sources In Slovakia / Legislatívna Úprava Obnoviteľných Zdrojov Energie Na Slovensku

Directory of Open Access Journals (Sweden)

Marišová Eleonóra

2015-12-01

Full Text Available Pestovanie energetickych rastlin a drevin na poľnohospodarskej pode a ďalšie využitie ich energie predstavuje zasadny vyznam pre realizaciu dlhodobej strategie Slovenska v oblasti ziskavania a využivania obnoviteľnych zdrojov energie (OZE. Energeticke rastliny spĺňaju ciele strategie Europa 2020 a prispievaju k diverzifi kacii energetickych zdrojov. Prispevok vychadza z pravnych predpisov EU a narodnej legislativy upravujucej OZE. Analyzovane su Smernica 2009/28/ES Europskeho parlamentu a Rady z 23. aprila 2009 o podpore využivania energie z obnoviteľnych zdrojov a o zmene a naslednom zrušeni smernic 2001/77/ES a 2003/30/ES. Tema obnoviteľnych zdrojov energie je integrovana do Programu rozvoja vidieka 2014 - 2020. Konkretne Akčny plan pre biomasu 2008-2013, Strategia vyššieho využitia obnoviteľnych zdrojov energie na Slovensku a Strategia energetickej bezpečnosti Slovenska bola prijata až do roku 2030. Trvalo udržateľne využivanie poľnohospodarskej pody, jeho riadenie a využivanie, ako aj ochrana jeho kvality a funkcie su upravene zakonom č 220/2004 Zb. o ochrane a využivani poľnohospodarskej pody a ktorym sa meni zakon č. 245/2003 Zb., o integrovanej prevencii a kontrole znečisťovania životneho prostredia a o zmene niektorych zakonov v zneni neskoršich predpisov, ktory nadobudol učinnosť 1. maja 2004. Zakon č. 57/2013 Zb., ktory je platny od 1. aprila 2013, stanovuje zasady a postup zriaďovania plantaži rychlorastucich drevin na poľnohospodarskej pode. Slovenska pravna uprava zaviedla register rychlo rastucich drevin na každom okresnom urade (72, na pozemkovom a lesnom odbore na Slovensku. Prieskum tychto registrov ukazuje, že tato pravna uprava podporuje poľnohospodarov, aby začali použivať marginalne pody pre rychlo rastuce dreviny.

Study on performance of blended fuel PPO - Diesel at generator

Science.gov (United States)

Prasetyo, Joni; Prasetyo, Dwi Husodo; Murti, S. D. Sumbogo; Adiarso, Priyanto, Unggul

2018-02-01

Bio-energy is renewable energy made from plant. Biomass-based energy sources are potentially CO2 neutral and recycle the same carbon atoms. In order to reduce pollution caused by fossil fuel combustion either for mechanical or electrical energy generation, the performance characteristic of purified palm oil blends are analyzed at various ratios. Bio-energy, Pure Plant Oil, represent a sustainable solution.A generator has been modified due to adapt the viscosity ofblended fuel, PPO - diesel, by pre-heating. Several PPO - diesel composition and injection timing were tested in order to investigate the characteristic of mixed fuel with and without pre-heating. The term biofuel refers to liquid or gaseous fuels for the internal combustion engines that are predominantly produced fro m biomass. Surprising result showed that BSFC of blended PPO - diesel was more efficient when injection timing set more than 15° BTDC. The mixed fuel produced power with less mixed fuel even though the calorie content of diesel is higher than PPO. The most efficient was 20% PPO in diesel with BSFC 296 gr fuel / kwh rather than 100% diesel with BSFC 309 gr fuel / kwh at the same injection timing 18° BTDC with pre-heating. The improvement of BSFC is caused by heating up of mixed fuel which it added calorie in the mixed fuel. Therefore, the heating up of blended PPO - diesel is not only to adapt the viscosity but also improving the efficiency of fuel usage representing by lower BSFC. In addition, torque of the 20% PPO was also as smooth as 100% diesel representing by almost the same torqueat injection timing 15° BTDC. The AIP Proceedings article template has many predefined paragraph styles for you to use/apply as you write your paper. To format your abstract, use the Microsoft Word template style: Abstract. Each paper must include an abstract. Begin the abstract with the word "Abstract" followed by a period in bold font, and then continue with a normal 9 point font.

Interaction Layer Characteristics in U-xMo Dispersion/Monolithic Fuels

International Nuclear Information System (INIS)

Porter, D.L.

2010-01-01

Published data concerning the interaction layer (IL) formed between U-xMo fuel alloy and aluminum (Al)-based matrix or cladding materials was reviewed, including the effects of silicon (Si) content in the matrix/cladding, molybdenum (Mo) content in the fuel, pre irradiation thermal treatments, irradiation, and test temperature. The review revealed that tests conducted in the laboratory produce results different from those conducted in an irradiation environment. However, the laboratory testing relates well to thermal treatments performed prior to irradiation and helps in understanding the effects that these pre irradiation treatments have on in reactor performance. A pre-formed, Si-enriched IL seems to be important in delaying the onset of rapid growth of fission gas bubbles at low irradiation temperatures. Several other conclusions can be drawn: (1) An IL with phases akin to UAl3 is desired for optimum fuel performance, but at low temperatures, and especially in an irradiation atmosphere, the desired (Al+Si)/(U+Mo) ratio of three is difficult to produce. When the fuel operating temperature is low, it is important to create a pre-irradiation IL, enriched in Si. This pre-formed IL is relatively stable, performs well in terms of swelling resistance, and prevents rapid IL growth during irradiation. (2) At higher operating temperatures (>150-170 C), IL formation in reactor may not be so dependent on pre-irradiation IL formation, especially at high burnup; a pre-fabricated IL seems to be less stable at high burnup and high operating temperature. Moreover, the (Al+SI)/(U+Mo) ratio of three occurs more often at higher temperature. For these two reasons, it is important at high operating temperature to also have a matrix with significant Si content to create an IL in reactor with the right characteristics. (3) Out-of-reactor testing seems to indicate that Si in the matrix material is required in some concentration (2%, 5%, ?) to provide for a thin, Si-enriched IL formed

Interaction Layer Characteristics in U-xMo Dispersion/Monolithic Fuels

Energy Technology Data Exchange (ETDEWEB)

D. L. Porter

2010-11-01

Published data concerning the interaction layer (IL) formed between U-xMo fuel alloy and aluminum (Al)-based matrix or cladding materials was reviewed, including the effects of silicon (Si) content in the matrix/cladding, molybdenum (Mo) content in the fuel, pre irradiation thermal treatments, irradiation, and test temperature. The review revealed that tests conducted in the laboratory produce results different from those conducted in an irradiation environment. However, the laboratory testing relates well to thermal treatments performed prior to irradiation and helps in understanding the effects that these pre irradiation treatments have on in reactor performance. A pre-formed, Si-enriched IL seems to be important in delaying the onset of rapid growth of fission gas bubbles at low irradaiiation temperatures. Several other conclusions can be drawn: 1. An IL with phases akin to UAl3 is desired for optimum fuel performance, but at low temperatures, and especially in an irradiation atmosphere, the desired (Al+Si)/(U+Mo) ratio of three is difficult to produce. When the fuel operating temperature is low, it is important to create a pre-irradiation IL, enriched in Si. This pre-formed IL is relatively stable, performs well in terms of swelling resistance, and prevents rapid IL growth during irradiation. 2. At higher operating temperatures (>150–170°C), IL formation in reactor may not be so dependent on pre-irradiation IL formation, especially at high burnup; a pre-fabricated IL seems to be less stable at high burnup and high operating temperature. Moreover, the (Al+SI)/(U+Mo) ratio of three occurs more often at higher temperature. For these two reasons, it is important at high operating temperature to also have a matrix with significant Si content to create an IL in reactor with the right characteristics. 3. Out-of-reactor testing seems to indicate that Si in the matrix material is required in some concentration (2%, 5%, ?) to provide for a thin, Si-enriched IL formed

A light hydrocarbon fuel processor producing high-purity hydrogen

Science.gov (United States)

Löffler, Daniel G.; Taylor, Kyle; Mason, Dylan

This paper discusses the design process and presents performance data for a dual fuel (natural gas and LPG) fuel processor for PEM fuel cells delivering between 2 and 8 kW electric power in stationary applications. The fuel processor resulted from a series of design compromises made to address different design constraints. First, the product quality was selected; then, the unit operations needed to achieve that product quality were chosen from the pool of available technologies. Next, the specific equipment needed for each unit operation was selected. Finally, the unit operations were thermally integrated to achieve high thermal efficiency. Early in the design process, it was decided that the fuel processor would deliver high-purity hydrogen. Hydrogen can be separated from other gases by pressure-driven processes based on either selective adsorption or permeation. The pressure requirement made steam reforming (SR) the preferred reforming technology because it does not require compression of combustion air; therefore, steam reforming is more efficient in a high-pressure fuel processor than alternative technologies like autothermal reforming (ATR) or partial oxidation (POX), where the combustion occurs at the pressure of the process stream. A low-temperature pre-reformer reactor is needed upstream of a steam reformer to suppress coke formation; yet, low temperatures facilitate the formation of metal sulfides that deactivate the catalyst. For this reason, a desulfurization unit is needed upstream of the pre-reformer. Hydrogen separation was implemented using a palladium alloy membrane. Packed beds were chosen for the pre-reformer and reformer reactors primarily because of their low cost, relatively simple operation and low maintenance. Commercial, off-the-shelf balance of plant (BOP) components (pumps, valves, and heat exchangers) were used to integrate the unit operations. The fuel processor delivers up to 100 slm hydrogen >99.9% pure with <1 ppm CO, <3 ppm CO 2. The

Beginning-of-life gap closure behaviour of experimental PFBR MOX fuel pin

International Nuclear Information System (INIS)

Jayaraj, V.V.; Padalakshmi, M.; Ojha, B.K.; Padma Prabu, C.; Saravanan, T.; Venkiteswaran, C.N.; Philip, John; Muralidharan, N.G.; Joseph, Jojo; Kasiviswanathan, K.V.; Jayakumar, T.

2011-01-01

Mixed oxide fuel with 22 % and 29% plutonium is chosen as the fuel for PFBR for the two fissile zones. Due to the fabrication tolerances in the pellet diameter, fuel has to be preconditioned at a lower linear power for a brief period before raising the power to the rated value of 450 W/cm. PIE was done on an experimental MOX fuel pin irradiated in FBTR for 13 days at a linear power of 400 W/cm for gap closure studies with the objective of optimising the duration of pre-conditioning before raising the power to the design value of 450 W/cm. X-radiography and remote metallography was done on the fuel pin to estimate the axial fuel column elongation and fuel-clad gap. Remote metallography of the fuel pin cross-sections at five axial locations of the fuel column and the subsequent fuel-clad gap measurement has indicated that the average radial gap has reduced from the pre-irradiation value of 75-110 microns to around 12-13 microns along the entire length of the fuel column. This paper will describe the details of examinations and results of the PIE carried out on the MOX fuel pin. (author)

Nuclear fuel assembly

International Nuclear Information System (INIS)

1975-01-01

The nuclear fuel assembly described includes a cluster of fuel elements supported at a distance from each other so that their axes are parallel in order to establish secondary channels between them reserved for the coolant. Several ducts for an auxiliary cooling fluid are arranged in the cluster. The wall of each duct is pierced with coolant ejection holes which are placed circumferentially to a pre-determined pattern established according to the position of the duct in the cluster and by the axial distance of the ejection hole along the duct. This assembly is intended for reactors cooled by light or heavy water [fr

The effects of pre-mix on burn in ICF capsules

International Nuclear Information System (INIS)

Wilson, D C; Kyrala, G A; Jr, J F Benage; Wysocki, F J; Gunderson, M A; Herrman, H W; Cooley, J H; Welser-Sherrill, L; Garbett, W J; Horsfield, C J; Glebov, V Y; Yaakobi, B; Roberts, S A; Frenje, J

2008-01-01

Directly driven implosions at the Omega laser have tested the effects of pre-mix of Ar, Kr, and Xe in D 2 + 3 He filled glass micro-balloons. Diagnostics included: D+D and D+T neutron yields, D+ 3 He proton yields and spectra, Doppler broadened ion temperatures, time dependent neutron and proton burn rates, and time gated, high energy filtered, X-ray images. Yields are better calculated by XSN LTE than by non-LTE. Yields with a small amount of pre-mix, atom fractions of ∼5e-3 for Ar, 2e-3 Kr, and Xe for 5e-4, are more degraded than calculated, while the measured ion temperatures are the same as without pre-mix. There is also a decrease in fuel ρr. The neutron burn histories suggest that the early yield coming before the reflected shock strikes the incoming shell is un-degraded, with yield degradation occurring afterwards. Adding 20 atm % 3 He to pure D fuel seems to produce a similar degradation. Calculated gated X-ray images agree with observed when the reflected shock strikes the incoming shell, but are smaller than observed afterward. This partially explains yield degradation and both the low fuel and whole capsule ρr's observed in secondary T+D neutrons and slowing of the D+ 3 He protons. Neither LTE on non-LTE captures the degradation by 3 He or at low pre-mix levels, nor matches the large shell radii after impact of the reflected shock

Effect of Glycemic Index of a Pre-exercise Meal on Endurance Exercise Performance

NARCIS (Netherlands)

Burdon, Catriona A.; Spronk, Inge; Cheng, Hoi Lun; O’Connor, Helen T.

2017-01-01

Background: Low glycemic index (GI) pre-exercise meals may enhance endurance performance by maintaining euglycemia and altering fuel utilization. However, evidence for performance benefits is equivocal. Objective: To evaluate the effect of a low GI (LGI) versus a high GI (HGI) pre-exercise meal on

Fuel rod failure due to marked diametral expansion and fuel rod collapse occurred in the HBWR power ramp experiment

International Nuclear Information System (INIS)

Yanagisawa, Kazuaki

1985-12-01

In the power ramp experiment with the BWR type light water loop at the HBWR, the two pre-irradiated fuel rods caused an unexpected pellet-cladding interaction (PCI). One occurred in the fuel rod with small gap of 0.10 mm, which was pre-irradiated up to the burn-up of 14 MWd/kgU. At high power, the diameter of the rod was increased markedly without accompanying significant axial elongation. The other occurred in the rod with a large gap of 0.23 mm, which was pre-irradiated up to the burn-up of 8 MWd/kgU. The diameter of the rod collapsed during a diameter measurement at the maximum power level. The causes of those were investigated in the present study by evaluating in-core data obtained from equipped instruments in the experiment. It was revealed from the investigation that these behaviours were attributed to the local reduction of the coolant flow occurred in the region of a transformer in the ramp rig. The fuel cladding material is seemed to become softened due to temperature increase caused by the local reduction of the coolant flow, and collapsed by the coolant pressure, either locally or wholly depending on the rod diametral gap existed. (author)

Method of making nuclear fuel bodies

International Nuclear Information System (INIS)

Davis, D.E.; Leary, D.F.

1977-01-01

A method of making nuclear fuel bodies is described comprising: providing particulate graphite having a particle size not greater than about 1500 microns; impregnating the graphite with a polymerizable organic resin in liquid form; treating the impregnated particles with a hot aqueous acid solution to pre-cure the impregnated resin and to remove excess resin from the surfaces of said graphite particles; heating the treated particles to polymerize the impregnant; blending the impregnated particles with particulate nuclear fuel; and forming a nuclear fuel body by joining the blend of particles into a cohesive mass using a carbonaceous binder

Automated Fuel Element Closure Welding System

International Nuclear Information System (INIS)

Wahlquist, D.R.

1993-01-01

The Automated Fuel Element Closure Welding System is a robotic device that will load and weld top end plugs onto nuclear fuel elements in a highly radioactive and inert gas environment. The system was developed at Argonne National Laboratory-West as part of the Fuel Cycle Demonstration. The welding system performs four main functions, it (1) injects a small amount of a xenon/krypton gas mixture into specific fuel elements, and (2) loads tiny end plugs into the tops of fuel element jackets, and (3) welds the end plugs to the element jackets, and (4) performs a dimensional inspection of the pre- and post-welded fuel elements. The system components are modular to facilitate remote replacement of failed parts. The entire system can be operated remotely in manual, semi-automatic, or fully automatic modes using a computer control system. The welding system is currently undergoing software testing and functional checkout

Fuel management approach in IRIS Reactor

International Nuclear Information System (INIS)

Petrovic, B.; Franceschini, F.

2004-01-01

This paper provides an overview of fuel management approach employed in IRIS (International Reactor Innovative and Secure). It introduces the initial, rather ambitious, fuel management goals and discusses their evolution that reflected the fast pace of progress of the overall project. The updated objectives rely on using currently licensed fuel technology, thus enabling near-term deployment of IRIS, while still providing improved fuel utilization. The paper focuses on the reference core design and fuel management strategy that is considered in pre-application licensing, which enables extended cycle of three to four years. The extended cycle reduces maintenance outage time and increases capacity factor, thus reducing the cost of electricity. Approaches to achieving this goal are discussed, including use of different reloading strategies. Additional fuel management options, which are not part of the licensing process, but are pursued as long-term research for possible future implementation, are presented as well. (Author)

40 CFR 91.408 - Pre-test procedures.

Science.gov (United States)

2010-07-01

....408 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED... accordance with § 91.117. (b) Engine pre-test preparation. (1) Drain and charge the fuel tank(s) with the..., including the sample probe, using mode 1 from Table 2 in appendix A of this subpart. The emission sampling...

Direct electrical heating of irradiated metal fuel

International Nuclear Information System (INIS)

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

1985-01-01

The Integral Fast Reactor (IFR) concept proposed by Argonne National Laboratory utilizes a metal fuel core. Reactor safety analysis requires information on the potential for fuel axial expansion during severe thermal transients. In addition to a comparatively large thermal expansion coefficient, metallic fuel has a unique potential for enhanced pre-failure expansion driven by retained fission gas and ingested bond sodium. In this paper, the authors present preliminary results from three direct electrical heating (DEH) experiments performed on irradiated metal fuel to investigate axial expansion behavior. The test samples were from Experimental Breeder Reactor II (EBR-II) driver fuel ML-11 irradiated to 8 at.% burnup. Preliminary analysis of the results suggest that enhanced expansion driven by trapped fission gas can occur

Development of Mitsubishi--Lurgi fluidized bd incinerator with pre-drying hearths

Energy Technology Data Exchange (ETDEWEB)

Hori, Y; Senshu, A; Mishima, K; Sato, T; Honda, H

1979-02-01

For a better disposal of a steadily increasing volume of sludges with energy conservation it is essential to develop an effective and energy-saving incinerator. The fluidized bed incinerator now widely used for the disposal of sludges has many superior features as compared with the conventional vertical multiple-hearth incinerator, but, on the other hand, has a defect, that is, a large fuel consumption. This is due to the fact that the fluidized bed incinerator has generally low drying efficiency notwithstanding its excellent burning characteristics with minimum excess air. The feasibility of fuel saving by installing sludge pre-drying hearths and an exhaust gas recirculation system additionally on the conventional fluidized bed incinerator and conducted incineration tests on various kinds of sludges, using a 1500 kg/h pilot plant equipped with the incinerator is examined. As the result, the Mitsubishi--Lurgi fluidized bed incinerator with high efficiency multiple pre-drying hearths which consumes less fuel was developed. Part of the incineration test results are presented.

Fuel safety research 2000

Energy Technology Data Exchange (ETDEWEB)

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

2001-03-01

In April 1999, the Fuel Safety Research Laboratory was newly established as a part of reorganization of the Nuclear Safety Research Center, JAERI. The new laboratory was organized by combining three pre-existing laboratories, Reactivity Accident Laboratory, Fuel Reliability Laboratory, and a part of Severe Accident Research Laboratory. The Fuel Safety Research Laboratory becomes to be in charge of all fuel safety research in JAERI. Various 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 following five research groups corresponding to each research fields; (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). The research activities in year 2000 produced many important data and information. They are, for example, failure of high burnup BWR fuel rod under RIA conditions, data on the behavior of hydrided Zircaloy cladding under LOCA conditions and FP release data from VEGA experiments at very high temperature/pressure condition. This report summarizes the outline of research activities and major outcomes of the research executed in 2000 in the Fuel Safety Research Laboratory. (author)

Recovered fuels - The connection between fuel preparation, combustion equipments and ash quality; Returbraenslen - kopplingen mellan braensleberedning, foerbraenningsutrustning och askkvalitet

Energy Technology Data Exchange (ETDEWEB)

Gyllenhammar, Marianne; Johansson, Inge [S.E.P. Scandinavian Energy Project AB, Goeteborg (Sweden)

2004-01-01

The lack of bio fuel and new regulations of waste treatment have increased the interest of recovered fuels. Co-combustion is of great interest, but the consequences and permit handling involved in introducing a new fuel into a plant have to be investigated. The aim of this study is to see if it is possible to affect the ash quality by pre-treatment of the fuel, or by firing in different combustion equipments. Ashes can be used in several different types of applications. Few of these have uniform requirements of ash quality. The ongoing research will hopefully help generating unified regulations and recommendations for the uses of ashes. However, right now the knowledge is limited and very specific. Every type of ash has to be analysed for the appropriate use. It is especially the requirements of leaching that are difficult to make general. The work started with a survey of recovered fuels. It contains roughly which fuels exist and which of those are accessible for the energy market in Sweden. The survey showed that there are approximately 13 Mton/y wastes partly accessible to the energy market; 50 % are used for material recycling, 32 % for energy recovery, 1.5 % for composting and the rest are used as landfill. Three recovered fuels were chosen and studied more thoroughly. These were PTP (paper, wood and plastic), tires and impregnated wood. The project showed that the recovered fuels have different qualifications as fuels and have different possibilities at co-combustion which results in variable ash quality. A pre-treated fuel is more homogeneous which give better combustion and cleaner ashes. A fluidised bed demands a more pre-treated fuel than a grate and the fluidised bed generate more ashes because the ashes contain bed material. As a result of this the ashes from a fluidised bed is generally easier to utilize. In this project the composition of ashes from co-combustion of the three recovered fuels together with wood fuel has been estimated. The aim was to

Motor fuel prices in Turkey

International Nuclear Information System (INIS)

Erdogdu, Erkan

2014-01-01

The world's most expensive motor fuel (gasoline, diesel and LPG) is sold most likely in the Republic of Turkey. This paper investigates the key issues related to the motor fuel prices in Turkey. First of all, the paper analyses the main reason behind high prices, namely motor fuel taxes in Turkey. Then, it estimates the elasticity of motor fuel demand in Turkey using an econometric analysis. The findings indicate that motor fuel demand in Turkey is quite inelastic and, therefore, not responsive to price increases caused by an increase in either pre-tax prices or taxes. Therefore, fuel market in Turkey is open to opportunistic behavior by firms (through excessive profits) and the government (through excessive taxes). Besides, the paper focuses on the impact of high motor fuel prices on road transport associated activities, including the pattern of passenger transportation, motorization rate, fuel use, total kilometers traveled and CO 2 emissions from road transportation. The impact of motor fuel prices on income distribution in Turkey and Turkish public opinion about high motor fuel prices are also among the subjects investigated in the course of the study. - Highlights: • The key issues (e.g. taxes) related to motor fuel prices in Turkey are explored. • Their impact on transport activities and income distribution is also investigated. • An econometric analysis is performed to estimate motor fuel demand in Turkey. • Motor fuel demand in Turkey is found to be quite inelastic. • Turkish fuel market is open to opportunistic behavior by firms and the government

Spent fuel container alignment device and method

Science.gov (United States)

Jones, Stewart D.; Chapek, George V.

1996-01-01

An alignment device is used with a spent fuel shipping container including a plurality of fuel pockets for spent fuel arranged in an annular array and having a rotatable cover including an access opening therein. The alignment device includes a lightweight plate which is installed over the access opening of the cover. A laser device is mounted on the plate so as to emit a laser beam through a laser admittance window in the cover into the container in the direction of a pre-established target associated with a particular fuel pocket. An indexing arrangement on the container provides an indication of the angular position of the rotatable cover when the laser beam produced by the laser is brought into alignment with the target of the associated fuel pocket.

In-cell refabrication of experimental pencils from pencils pre-irradiated in a power reactor

International Nuclear Information System (INIS)

Vignesoult, N.; Atabek, R.; Ducas, S.

1980-05-01

For the fuel-cladding study, small irradiated pencils were fabricated in a hot cell from long elements taken from power reactors. This reconstitution in a hot cell makes it possible to: - avoid long and costly fabrications of pencils and pre-irradiations in experimental reactors, - perform re-irradiations on very long fuel elements from power reactors, - fabricate several small pencils from one pre-irradiation pencil having homogeneous characteristics. This paper describes (a) the various in-cell fabrication stages of small pre-irradiated pencils, stressing the precautions taken to avoid any pollution and modifications in the characteristics of the pencil, in order to carry out a perfectly representative re-irradiation, (b) the equipment used and the quality control made, and (c) the results achieved and the qualification programme of this operation [fr

Storage arrangements for nuclear fuel

International Nuclear Information System (INIS)

Deacon, D.

1982-01-01

A storage arrangement for spent nuclear fuel either irradiated or pre-irradiated or for vitrified waste after spent fuel reprocessing, comprises a plenum chamber which has a base pierced by a plurality of openings each of which has sealed to it an open topped tube extending downwards and closed at its lower end. The plenum chamber, with the tubes, forms an air-filled enclosure associated with an exhaust system for exhausting air from the system through filters to maintain the interior of the enclosure at sub-atmospheric pressure. The tubes are arranged to accommodate the stored fuel and the arrangement includes a means for producing a flow of cooling air over the exterior of the tubes so that the latter effectively form a plurality of heat exchangers in close proximity to the fuel. The air may be caused to flow over the tube surfaces by a natural thermosyphon process. (author)

Effect of diesel pre-injection timing on combustion and emission characteristics of compression ignited natural gas engine

International Nuclear Information System (INIS)

Xu, Min; Cheng, Wei; Zhang, Hongfei; An, Tao; Zhang, Shaohua

2016-01-01

Highlights: • Pre-injection timing on combustion and emission of CING engine are studied. • Closely pre-injection operations leads to increase of combustion intensity. • Early pre-injection operations leads to lower combustion intensity. • Early pre-injection modes provide better NO x emission. - Abstract: Pre-injection strategy is considered to be one of the most important ways to improve diesel engine performance, emission and combustion. It is the same important factor in pilot diesel compression ignition natural gas (CING) engine. In this study, effects of pre-injection timing on combustion and emission performances were experimentally studied in a CING engine which was modified from a turbocharged six-cylinder diesel engine. The experiments were conducted at constant speed of 1400 rpm and different engine loads with a constant fuel injection pressure of 1100 bar. Main injection timing was fixed at 10 °CA BTDC in the advance process of pre-injection timing. The cylinder pressure, heart release rate (HRR), pressure rise rate (PRR), start of combustion (SOC) and coefficient of variation (COV IMEP ), as well as NO x , HC and CO emissions were analyzed. The results indicated that closely pre-injection operations lead to the advance of SOC which intensified combustion of in-cylinder mixture, thereby resulting in higher cylinder pressure, HRR and PRR, as well higher NO x emissions and lower HC and CO emissions. However, early pre-injection operations lead to lower cylinder pressure, HRR and PRR due to decreasing in combustion intensity. Pre-injection timing of 70 °CA BTDC is a conversion point in which influence of pre-injection fuel on ignition and combustion of natural gas nearly disappeared and lowest NO x emission could be obtained. Compared with single injection ignition mode, NO x emissions at the conversion point were reduced by 33%, 38% and 7% at engine load of 38%, 60% and 80% respectively. This is important for the conditions that ignition fuel

Compound process fuel cycle concept

International Nuclear Information System (INIS)

Ikegami, Tetsuo

2005-01-01

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

Fuel fired heat sources

Energy Technology Data Exchange (ETDEWEB)

Ortlinghaus, U

1977-09-08

Fuel fired heat sources with a valve-controlled ignition and main burner, whose flame is monitored and whose control valve is closed or opened by a controller according to the control deviation between actual and reference heat source temperature, previously suffered the disadvantage of high consumption of ignition gas. According to the invention this disadvantage is avoided by closing the ignition valve from the controller via a delay unit and having the delay time of the delay unit controlled either by the temperature measured by the sensor or increasing it with increasing deviation of the actual value of pre-temperature from the reference value of the pre-temperature.

PREP-PWR-1.0: a WIMS-D/4 pre-processor code for the generation of data for PWR fuel assemblies

International Nuclear Information System (INIS)

Ball, G.

1991-06-01

The PREP-PWR-1.0 computer code is a substantially modified version of the PREWIM code which formed part of the original MARIA System (Report J.E.N. 543). PREP-PWR-1.0 is a comprehensive pre-processor code which generates input data for the WIMS-D/4.1 code (Report PEL 294) for PWR fuel assemblies, with or without control and burnable poison rods. This data is generated at various base and off-base conditions. The overall cross section generation methodology is described, followed by a brief overview of the model. Aspects of the base/off-base calculational scheme are outlined. Additional features of the code are described while the input data format of PREP-PWR-1.0 is listed. The sample problems and suggestions for further improvements to the code are also described. 2 figs., 2 tabs., 12 refs

Fuel corrosion processes under waste disposal conditions

International Nuclear Information System (INIS)

Shoesmith, D.W.

1999-09-01

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

Fuel corrosion processes under waste disposal conditions

Energy Technology Data Exchange (ETDEWEB)

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

1999-09-01

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

Romanian nuclear fuel program

International Nuclear Information System (INIS)

Budan, O.

1999-01-01

of January 1997 with fuel produced by the Romanian fuel plant. The quality evaluation of the 'pre-1990' fuel started in April 1996 and was performed by the Nuclear Fuel Plant (FCN) Pitesti, under the supervision of the Nuclear Power Group (GEN) - a distinct department of RENEL. The paper presents the involvement of Romania in the activities related to the Advanced CANDU Fuel Cycle. The future prospect and trend of the Romanian Nuclear Fuel Program are also presented in this paper. (author)

Pre-conceptual Development and characterization of an extruded graphite composite fuel for the TREAT Reactor

Energy Technology Data Exchange (ETDEWEB)

Luther, Erik; Rooyen, Isabella van; Leckie, Rafael; Papin, Pallas; Nelson, Andrew; Hunter, James

2015-03-01

In an effort to explore fuel systems that are more robust under accident scenarios, the DOE-NE has identified the need to resume transient testing. The Transient Reactor Test (TREAT) facility has been identified as the preferred option for the resumption of transient testing of nuclear fuel in the United States. In parallel, NNSA’s Global Threat Reduction Initiative (GTRI) Convert program is exploring the needs to replace the existing highly enriched uranium (HEU) core with low enriched uranium (LEU) core. In order to construct a new LEU core, materials and fabrication processes similar to those used in the initial core fabrication must be identified, developed and characterized. In this research, graphite matrix fuel blocks were extruded and materials properties of were measured. Initially the extrusion process followed the historic route; however, the project was expanded to explore methods to increase the graphite content of the fuel blocks and explore modern resins. Materials properties relevant to fuel performance including density, heat capacity and thermal diffusivity were measured. The relationship between process defects and materials properties will be discussed.

HYDROGEN COMMERCIALIZATION: TRANSPORTATION FUEL FOR THE 21ST CENTURY

Energy Technology Data Exchange (ETDEWEB)

APOLONIO DEL TORO

2008-05-27

Since 1999, SunLine Transit Agency has worked with the U.S. Department of Energy (DOE), U.S. Department of Defense (DOD), and the U.S. Department of Transportation (DOT) to develop and test hydrogen infrastructure, fuel cell buses, a heavy-duty fuel cell truck, a fuel cell neighborhood electric vehicle, fuel cell golf carts and internal combustion engine buses operating on a mixture of hydrogen and compressed natural gas (CNG). SunLine has cultivated a rich history of testing and demonstrating equipment for leading industry manufacturers in a pre-commercial environment. Visitors to SunLine's "Clean Fuels Mall" from around the world have included government delegations and agencies, international journalists and media, industry leaders and experts and environmental and educational groups.

The Role of Fuel Breaks in the Invasion of Nonnative Plants

Science.gov (United States)

Merriam, Kyle E.; Keeley, Jon E.; Beyers, Jan L.

2007-01-01

Executive Summary Fuel reduction projects have become an increasingly important component of state and federal fuels management programs. However, an unintended result of some pre-fire fuel manipulation projects may be the introduction of nonnative invasive plants. The establishment of nonnative plants within fuel breaks is a serious concern because the presence of invasive species in areas treated to reduce fuels could make adjacent wildland areas more susceptible to invasion, particularly following widespread disturbances such as fires. This report presents the results of a research project investigating the relationship between fuel reduction treatments and the invasion of nonnative plants. Throughout the rest of this document, we will collectively refer to these treatments as fuel breaks, although we sampled a range of fuel breaks described variously as fuel breaks, shaded fuel breaks, defensible fuel reduction zones, defensible fuel profile zones, fuel reduction projects, fuel management zones, wildfire protection zones, and community protection zones.

Direct methanol feed fuel cell with reduced catalyst loading

Science.gov (United States)

Kindler, Andrew (Inventor)

1999-01-01

Improvements to direct feed methanol fuel cells include new protocols for component formation. Catalyst-water repellent material is applied in formation of electrodes and sintered before application of ionomer. A membrane used in formation of an electrode assembly is specially pre-treated to improve bonding between catalyst and membrane. The improved electrode and the pre-treated membrane are assembled into a membrane electrode assembly.

An examination of flame shape related to convection heat transfer in deep-fuel beds

Science.gov (United States)

Kara M. Yedinak; Jack D. Cohen; Jason M. Forthofer; Mark A. Finney

2010-01-01

Fire spread through a fuel bed produces an observable curved combustion interface. This shape has been schematically represented largely without consideration for fire spread processes. The shape and dynamics of the flame profile within the fuel bed likely reflect the mechanisms of heat transfer necessary for the pre-heating and ignition of the fuel during fire spread....

Pre-shipment preparations at the Savannah River Site - WSRC's technical basis to support DOE's approval to ship

International Nuclear Information System (INIS)

Thomas, Jay E.; Bickley, Donald W.; Conatser, E. Ray

2000-01-01

In the first four years of the Foreign Research Reactor (FRR) Spent Nuclear Fuel (SNF) Return Program following resumption of the SNF return program with the DOE-EIS ROD in May 1996, 13 shipments involving 77 casks with over 2,600 assemblies have been safely received and stored at the Savannah River Site (SRS). Each fuel type has gone through a rigorous pre-shipment preparation process that includes fuel characterization, criticality safety reviews, and operational reviews, culminating in the Department of Energy's (DOE's) authorization to ship. Ideally, the authorization to ship process should begin two years in advance of the fuel receipt with an agreement between the Department of Energy - Head Quarters (DOE-HQ) and the research reactor government on the conditions and protocol for the spent nuclear fuel return, with a target of DOE shipment authorization at least two months before facility loading. A visit by representatives from the Department of Energy - Savannah River (DOE-SR) and Westinghouse Savannah River Company (WSRC), DOE's Management and Operations (M and O) Contractor for the SRS, to the research reactor facility is then scheduled for the purpose of finalizing contractual arrangements (DOE-SR), facility assessments, and initial fuel inspections. An extensive effort is initiated at this time to characterize the fuel in a standard format as identified in the Appendix A attachment to the contract. The Appendix A must be finalized in an accurate and timely manner because it serves as the base reference document for WSRC and other involved stakeholders such as the cask owners and the competent authorities throughout the approval process. With the approval of the Appendix A, criticality safety reviews are initiated to evaluate the unloading and storage configurations. Operational reviews are conducted to allow for necessary adaptation of fuel handling facilities, procedures, and training. WSRC has proceduralized this process, 'Certification to Receive and

Automatic inspection for remotely manufactured fuel elements

International Nuclear Information System (INIS)

Reifman, J.; Vitela, J.E.; Gibbs, K.S.; Benedict, R.W.

1995-01-01

Two classification techniques, standard control charts and artificial neural networks, are studied as a means for automating the visual inspection of the welding of end plugs onto the top of remotely manufactured reprocessed nuclear fuel element jackets. Classificatory data are obtained through measurements performed on pre- and post-weld images captured with a remote camera and processed by an off-the-shelf vision system. The two classification methods are applied in the classification of 167 dummy stainless steel (HT9) fuel jackets yielding comparable results

Analysis of the influence of pre-DPF water injection technique on pollutants emission

OpenAIRE

Bermúdez, Vicente; Serrano Cruz, José Ramón; Piqueras, P.; Campos, Daniel

2015-01-01

The pressure drop across DPFs directly affects the exhaust back-pressure and fuel economy of compression ignition engines. Pressure drop is related to the soot trapped inside the DPF, increasing exhaust back-pressure as the soot mass loading does. Consequently, regeneration strategies are required to remove the soot collected in the DPF. However, these processes usually involve additional fuel consumption. Considering this context, control techniques to reduce the exhaust back-pre...

Development of tools to manage the operational monitoring and pre-design of the NPP-LV cycle; Desarrollo de herramientas para administrar el seguimiento operativo y el pre-diseno del ciclo de la CLV

Energy Technology Data Exchange (ETDEWEB)

Perusquia, R.; Arredondo S, C.; Hernandez M, J. L.; Montes T, J. L.; Castillo M, A.; Ortiz S, J. J., E-mail: raul.perusquia@inin.gob.mx [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

2015-09-15

This paper presents the development of tools to facilitate the management so much, the operational monitoring of boiling water reactors (BWR) of the nuclear power plant of Laguna Verde (NPP-LV) through independent codes, and how to carry out the static calculations corresponding to process of optimized pre-design of the reference cycle next to current cycle. The progress and preliminary results obtained with the program SACal, developed at Instituto Nacional de Investigaciones Nucleares (ININ), central tool to achieve provide a management platform of the operational monitoring and pre-design of NPP-LV cycle are also described. The reached preliminary advances directed to get an Analysis center and automated design of fuel assembly cells are also presented, which together with centers or similar modules related with the fuel reloads form the key part to meet the targets set for the realization of a Management Platform of Nuclear Fuel of the NPP-LV. (Author)

A Study on Fuel Estimation Algorithms for a Geostationary Communication & Broadcasting Satellite

OpenAIRE

Jong Won Eun

2000-01-01

It has been developed to calculate fuel budget for a geostationary communication and broadcasting satellite. It is quite essential that the pre-launch fuel budget estimation must account for the deterministic transfer and drift orbit maneuver requirements. After on-station, the calculation of satellite lifetime should be based on the estimation of remaining fuel and assessment of actual performance. These estimations step from the proper algorithms to produce the prediction of satellite lifet...

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

International Nuclear Information System (INIS)

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

2017-01-01

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

Vision and strategy development of Slovak society. Development Strategy for Slovak society (basis for public adversary); Vizia a strategia rozvoja slovenskej spolocnosti. Strategia rozvoja slovenskej spolocnosti (Podklad pre verejnu oponenturu)

Energy Technology Data Exchange (ETDEWEB)

Sikula, V [ed.; Okali, I; Klas, A [Ekonomicky ustav, Slovenska akademia vied, Bratislava (Slovakia); Bercik, P [Ministerstvo vnutra SR, Bratislava (Slovakia); Peknik, M [Ustav politickych vied, Slovenska akademia vied, Bratislava (Slovakia); Tirpak, I [Recyklacny fond, Bratislava (Slovakia); Bucek, M [Narodohospodarska fakulta Ekonomickej univerzity v Bratislave (Slovakia)

2010-02-15

This analytical study analyses the present state as well as strategy of perspectives of development of Slovak society. This strategy of development of Slovak society is scientific testimony of the authors, the manner and extent of its use will determine political representation. Future economic growth and development of Slovak's regions will mainly depend on the availability of raw materials, energy resources, water, food processes and improving the environment. A key issue in the next 5 to 10 years in the energy sector will address energy security, diversification of energy sources, utilization of domestic raw materials and renewable energy and energy savings. The energy security strategy is to achieve a competitive energy industry for reliable and efficient supply of all forms of energy at affordable prices, with a view to protection of the customer and the environment.

FAILED FUEL DISPOSITION STUDY

International Nuclear Information System (INIS)

THIELGES, J.R.

2004-01-01

In May 2004 alpha contamination was found on the lid of the pre-filter housing in the Sodium Removal Ion Exchange System during routine filter change. Subsequent investigation determined that the alpha contamination likely came from a fuel pin(s) contained in an Ident-69 (ID-69) type pin storage container serial number 9 (ID-69-9) that was washed in the Sodium Removal System (SRS) in January 2004. Because all evidence indicated that the wash water interacted with the fuel, this ID49 is designated as containing a failed fuel pin with gross cladding defect and was set aside in the Interim Examination and Maintenance (IEM) Cell until it could be determined how to proceed for long term dry storage of the fuel pin container. This ID49 contained fuel pins from the driver fuel assembly (DFA) 16392, which was identified as a Delayed Neutron Monitor (DNM) leaker assembly. However, this DFA was disassembled and the fuel pin that was thought to be the failed pin was encapsulated and was not located in this ID49 container. This failed fuel disposition study discusses two alternatives that could be used to address long term storage for the contents of ID-69-9. The first alternative evaluated utilizes the current method of identifying and storing DNM leaker fuel pin(s) in tubes and thus, verifying that the alpha contamination found in the SRS came from a failed pin in this pin container. This approach will require unloading selected fuel pins from the ID-69, visually examining and possibly weighing suspect fuel pins to identify the failed pin(s), inserting the failed pin(s) in storage tubes, and reloading the fuel pins into ID49 containers. Safety analysis must be performed to revise the 200 Area Interim Storage Area (ISA) Final Safety Analysis Report (FSAR) (Reference 1) for this fuel configuration. The second alternative considered is to store the failed fuel as-is in the ID-69. This was evaluated to determine if this approach would comply with storage requirements. This

FAILED FUEL DISPOSITION STUDY

Energy Technology Data Exchange (ETDEWEB)

THIELGES, J.R.

2004-12-20

In May 2004 alpha contamination was found on the lid of the pre-filter housing in the Sodium Removal Ion Exchange System during routine filter change. Subsequent investigation determined that the alpha contamination likely came from a fuel pin(s) contained in an Ident-69 (ID-69) type pin storage container serial number 9 (ID-69-9) that was washed in the Sodium Removal System (SRS) in January 2004. Because all evidence indicated that the wash water interacted with the fuel, this ID49 is designated as containing a failed fuel pin with gross cladding defect and was set aside in the Interim Examination and Maintenance (IEM) Cell until it could be determined how to proceed for long term dry storage of the fuel pin container. This ID49 contained fuel pins from the driver fuel assembly (DFA) 16392, which was identified as a Delayed Neutron Monitor (DNM) leaker assembly. However, this DFA was disassembled and the fuel pin that was thought to be the failed pin was encapsulated and was not located in this ID49 container. This failed fuel disposition study discusses two alternatives that could be used to address long term storage for the contents of ID-69-9. The first alternative evaluated utilizes the current method of identifying and storing DNM leaker fuel pin(s) in tubes and thus, verifying that the alpha contamination found in the SRS came from a failed pin in this pin container. This approach will require unloading selected fuel pins from the ID-69, visually examining and possibly weighing suspect fuel pins to identify the failed pin(s), inserting the failed pin(s) in storage tubes, and reloading the fuel pins into ID49 containers. Safety analysis must be performed to revise the 200 Area Interim Storage Area (ISA) Final Safety Analysis Report (FSAR) (Reference 1) for this fuel configuration. The second alternative considered is to store the failed fuel as-is in the ID-69. This was evaluated to determine if this approach would comply with storage requirements. This

Baumot BA-B Diesel Particulate Filter with Pre-Catalyst (ETV Mobile Source Emissions Control Devices) Verification Report

Science.gov (United States)

The Baumot BA-B Diesel Particulate Filter with Pre-Catalyst is a diesel engine retrofit device for light, medium, and heavy heavy-duty diesel on-highway engines for use with commercial ultra-low-sulfur diesel (ULSD) fuel. The BA-B particulate filter is composed of a pre-catalyst ...

Core instrumentation and pre-operational procedures for core conversion HEU to LEU

International Nuclear Information System (INIS)

1984-02-01

This report is intended for the reactor operator, to be used as a manual or checklist for general guidance on pre-startup activities that need to be addressed in preparation for conversion to Low Enriched Fuel (LEU). All nuclear, thermodynamic and safety calculations should have been performed prior to this stage of the core conversion process. During these calculations and certainly before ordering the new LEU fuel elements the reactor operator needs to very carefully consider additional important factors concerning the new fuel: fuel reliability, reliability of fuel fabricator, reprocessing contract or fuel element storage and disposal, economics of the new fuel cycle. At this stage, too, a preoperational experimental programme has to be developed and presented to the regulatory authorities for approval. This experimental programme could lead to additional requirements on: in-core instrumentation, out-of-core instrumentation or additional experimental devices. Detailed instructions on specific tests and measurements are not provided in this report since much information on the subject is available in the open literature

Plant characteristics of an integrated solid oxide fuel cell cycle and a steam cycle

International Nuclear Information System (INIS)

Rokni, Masoud

2010-01-01

Plant characteristics of a system containing a solid oxide fuel cell (SOFC) cycle on the top of a Rankine cycle were investigated. A desulfurization reactor removes the sulfur content in the fuel, while a pre-reformer broke down the heavier hydrocarbons in an adiabatic steam reformer (ASR). The pre-treated fuel then entered to the anode side of the SOFC. The remaining fuels after the SOFC stacks entered a catalytic burner for further combusting. The burned gases from the burner were then used to produce steam for the Rankine cycle in a heat recovery steam generator (HRSG). The remaining energy of the off-gases was recycled back to the topping cycle for further utilization. Several parameter studies were carried out to investigate the sensitivity of the suggested plant. It was shown that the operation temperature of the desulfurization and the pre-reformer had no effect on the plant efficiency, which was also true when decreasing the anode temperature. However, increasing the cathode temperature had a significant effect on the plant efficiency. In addition, decreasing the SOFC utilization factor from 0.8 to 0.7, increases the plant efficiency by about 6%. An optimal plant efficiency of about 71% was achieved by optimizing the plant.

Plant characteristics of an integrated solid oxide fuel cell cycle and a steam cycle

Energy Technology Data Exchange (ETDEWEB)

Rokni, Masoud [Technical University of Denmark, Dept. of Mechanical Engineering, Thermal Energy System, Building 402, 2800 Kgs, Lyngby (Denmark)

2010-12-15

Plant characteristics of a system containing a solid oxide fuel cell (SOFC) cycle on the top of a Rankine cycle were investigated. A desulfurization reactor removes the sulfur content in the fuel, while a pre-reformer broke down the heavier hydrocarbons in an adiabatic steam reformer (ASR). The pre-treated fuel then entered to the anode side of the SOFC. The remaining fuels after the SOFC stacks entered a catalytic burner for further combusting. The burned gases from the burner were then used to produce steam for the Rankine cycle in a heat recovery steam generator (HRSG). The remaining energy of the off-gases was recycled back to the topping cycle for further utilization. Several parameter studies were carried out to investigate the sensitivity of the suggested plant. It was shown that the operation temperature of the desulfurization and the pre-reformer had no effect on the plant efficiency, which was also true when decreasing the anode temperature. However, increasing the cathode temperature had a significant effect on the plant efficiency. In addition, decreasing the SOFC utilization factor from 0.8 to 0.7, increases the plant efficiency by about 6%. An optimal plant efficiency of about 71% was achieved by optimizing the plant. (author)

Accountability study for TMI-2 fuel

International Nuclear Information System (INIS)

Goris, P.; Scott, D.D.

1981-05-01

The TMI-2 accountability study considers problems of identifying, measuring, and accounting for TMI-2 fuel in the resident condition, as it is removed from the reactor, during subsequent cleanup, and during post-removal examinations. The goal is to identify methods and procedures which will provide a verifiable material balance equating to the pre-accident balance

Thorium fuel for light water reactors - reducing proliferation potential of nuclear power fuel cycle

Energy Technology Data Exchange (ETDEWEB)

Galperin, A; Radkowski, A [Ben-Gurion Univ. of the Negev, Beersheba (Israel)

1996-12-01

The proliferation potential of the light water reactor fuel cycle may be significantly reduced by utilization of thorium as a fertile component of the nuclear fuel. The main challenge of Th utilization is to design a core and a fuel cycle, which would be proliferation-resistant and economically feasible. This challenge is met by the Radkowsky Thorium Reactor (RTR) concept. So far the concept has been applied to a Russian design of a 1,000 MWe pressurized water reactor, known as a WWER-1000, and designated as VVERT. The following are the main results of the preliminary reference design: * The amount of Pu contained in the RTR spent fuel stockpile is reduced by 80% in comparison with a VVER of a current design. * The isotopic composition of the RTR-Pu greatly increases the probability of pre-initiation and yield degradation of a nuclear explosion. An extremely large Pu-238 content causes correspondingly large heat emission, which would complicate the design of an explosive device based on RTR-Pu. The economic incentive to reprocess and reuse the fissile component of the RTR spent fuel is decreased. The once-through cycle is economically optimal for the RTR core and cycle. To summarize all the items above: the replacement of a standard (U-based) fuel for nuclear reactors of current generation by the RTR fuel will provide an inherent barrier for nuclear weapon proliferation. This inherent barrier, in combination with existing safeguard measures and procedures is adequate to unambiguously disassociate civilian nuclear power from military nuclear power. * The RTR concept is applied to existing power plants to assure its economic feasibility. Reductions in waste disposal requirements, as well as in natural U and fabrication expenses, as compared to a standard WWER fuel, provide approximately 20% reduction in fuel cycle (authors).

Calibration of spent fuel measurement assembly

International Nuclear Information System (INIS)

Koleska, Michal; Viererbl, Ladislav; Marek, Milan

2014-01-01

The LVR-15 research reactor (Czech Republic) had been converted from the highly enriched IRT-2M to the low enriched IRT-4M fuel. For the possibility of the independent pre-transport evaluation of IRT-2M burnup, a spectrometric system was developed. This spectrometric system consists of the fuel holder, the collimator and the portable Canberra Big MAC HPGe (High Purity Germanium) detector. In order to have well reproducible and reliable experimental data for modeling of the measurement system, calibration with the 110m Ag isotope with known activity was performed. This isotope was chosen for having energies similar to isotopes measured in fuel assemblies. The 110m Ag isotope was prepared by irradiating of the silver foil in LVR-15 research reactor; its activity was evaluated in the LVR-15's spectrometric laboratory. From the measured data, an efficiency curve of the spectrometric system has been determined. The experimental data were compared to the calculation results with the MCNPX model of the spectrometric system. - Highlights: • Calibration of research reactor spent fuel measurement assembly. • On-site prepared 110m Ag isotope used for the measurement. • Calculated self-shielding factor for the IRT-2M fuel. • Applicable to other research reactor fuel geometries

Fuel pin failure in the PFR/TREAT experiments

International Nuclear Information System (INIS)

Herbert, R.; Hunter, C.W.; Kramer, J.M.; Wood, M.H.; Wright, A.E.

1986-01-01

The PFR/TREAT safety testing programme involves the transient testing of fresh and pre-irradiated UK and US fuel pins. This paper summarizes the experimental and calculational results obtained to date on fuel pin failure during transient overpower (resulting from an accidental addition of resolivity) and transient undercooling followed by overpower (arising from an accidental stoppage of the primary sodium circulating pumps) accidents. Companion papers at this conference address: (I) the progress and future plans of the programme, and (II) post-failure material movements

Greenfield Alternative Study LEU-Mo Fuel Fabrication Facility

Energy Technology Data Exchange (ETDEWEB)

Washington Division of URS

2008-07-01

This report provides the initial “first look” of the design of the Greenfield Alternative of the Fuel Fabrication Capability (FFC); a facility to be built at a Greenfield DOE National Laboratory site. The FFC is designed to fabricate LEU-Mo monolithic fuel for the 5 US High Performance Research Reactors (HPRRs). This report provides a pre-conceptual design of the site, facility, process and equipment systems of the FFC; along with a preliminary hazards evaluation, risk assessment as well as the ROM cost and schedule estimate.

Multiplexed electrospray scaling for liquid fuel injection

International Nuclear Information System (INIS)

Waits, C Mike; Hanrahan, Brendan; Lee, Ivan

2010-01-01

Evaporation and space-charge requirements are evaluated to understand the effect of device scaling and fuel preheating for a liquid fuel injector using a multiplexed electrospray (MES) configuration in compact combustion applications. This work reveals the influence of the droplet diameter, droplet velocity and droplet surface temperature as well as the surrounding gas temperature on the size and performance of microfabricated MES. Measurements from MES devices are used in the model to accurately account for the droplet diameter versus flow rate relationship, the minimum droplet diameter and the relevant droplet velocities. A maximum extractor electrode to ground electrode distance of 3.1 mm required to overcome space-charge forces is found to be independent of voltage or droplet velocity for large levels of multiplexing. This maximum distance also becomes the required evaporation length scale which imposes minimum fuel pre-heating requirements for large flow densities. Required fuel preheating is therefore evaluated for both ethanol and 1-butanol with combustor parameters relevant to fuel reformation, thermoelectric conversion, thermophotovoltaic conversion and thermionic conversion

Pie technique of LWR fuel cladding fracture toughness test

International Nuclear Information System (INIS)

Endo, Shinya; Usami, Koji; Nakata, Masahito; Fukuda, Takuji; Numata, Masami; Kizaki, Minoru; Nishino, Yasuharu

2006-01-01

Remote-handling techniques were developed by cooperative research between the Department of Hot Laboratories in the Japan Atomic Energy Research Institute (JAERI) and the Nuclear Fuel Industries Ltd. (NFI) for evaluating the fracture toughness on irradiated LWR fuel cladding. The developed techniques, sample machining by using the electrical discharge machine (EDM), pre-cracking by fatigue tester, sample assembling to the compact tension (CT) shaped test fixture gave a satisfied result for a fracture toughness test developed by NFL. And post-irradiation examination (PIE) using the remote-handling techniques were carried out to evaluate the fracture toughness on BWR spent fuel cladding in the Waste Safety Testing Facility (WASTEF). (author)

Duration of fuels reduction following prescribed fire in coniferous forests of U.S. national parks in California and the Colorado Plateau

Science.gov (United States)

van Mantgem, Phillip J.; Lalemand, Laura; Keifer, MaryBeth; Kane, Jeffrey M.

2016-01-01

Prescribed fire is a widely used forest management tool, yet the long-term effectiveness of prescribed fire in reducing fuels and fire hazards in many vegetation types is not well documented. We assessed the magnitude and duration of reductions in surface fuels and modeled fire hazards in coniferous forests across nine U.S. national parks in California and the Colorado Plateau. We used observations from a prescribed fire effects monitoring program that feature standard forest and surface fuels inventories conducted pre-fire, immediately following an initial (first-entry) prescribed fire and at varying intervals up to >20 years post-fire. A subset of these plots was subjected to prescribed fire again (second-entry) with continued monitoring. Prescribed fire effects were highly variable among plots, but we found on average first-entry fires resulted in a significant post-fire reduction in surface fuels, with litter and duff fuels not returning to pre-fire levels over the length of our observations. Fine and coarse woody fuels often took a decade or longer to return to pre-fire levels. For second-entry fires we found continued fuels reductions, without strong evidence of fuel loads returning to levels observed immediately prior to second-entry fire. Following both first- and second-entry fire there were increases in estimated canopy base heights, along with reductions in estimated canopy bulk density and modeled flame lengths. We did not find evidence of return to pre-fire conditions during our observation intervals for these measures of fire hazard. Our results show that prescribed fire can be a valuable tool to reduce fire hazards and, depending on forest conditions and the measurement used, reductions in fire hazard can last for decades. Second-entry prescribed fire appeared to reinforce the reduction in fuels and fire hazard from first-entry fires.

Dry Refabrication Technology Development of Spent Nuclear Fuel

International Nuclear Information System (INIS)

Lee, Jung Won; Park, G. I.; Park, C. J.

2010-04-01

Key technical data on advanced nuclear fuel cycle technology development for the spent fuel recycling have been produced in this study. In the frame work of DUPIC, dry process oxide products fabrication, hot cell experimental data for decladding, powdering and oxide product fabrication from low and high burnup spent fuel have been produced, basic technology for fabrication of spent fuel standard material has been developed, and remote modulated welding equipment has been designed and fabricated. In the area of advanced pre-treatment process development, a rotary-type oxidizer and spherical particle fabrication process were developed by using SIMFUEL and off-gas treatment technology and zircalloy tube treatment technology were studied. In the area of the property characteristics of dry process products, fabrication technology of simulated dry process products was established and property models were developed based on reproducible property measurement data

Development of U-Mo/Al dispersion fuel for research reactors

Energy Technology Data Exchange (ETDEWEB)

Park, Jong Man; Ryu, Ho Jin; Yang, Jae Ho; Jeong, Yong Jin; Lee, Yoon Sang [Korea Atomic Energy Research Inst., Research Reactor Fuel Development Division, Daejeon (Korea, Republic of)

2012-03-15

Currently, the KOMO-5 irradiation test for full size U-Mo/Al dispersion fuel rods has been underway since May 23, 2011. The purpose of the KOMO-5 test includes an investigation of the irradiation behaviors of silicide or nitride coated U-7Mo/Al(-Si) dispersion fuels and the effects of pre-formed interaction layers on U-Mo particles. It is expected that the irradiation test will be finished after attaining 60 at% U-235 burnup in May 2012, and the first PIE results of the KOMO-5 will be obtained in September 2012. In addition, an international cooperation program on the qualification of U-Mo dispersion fuels for small and medium size research reactors is going to be proposed in cooperation with the IAEA. Conversion from silicide fuel to U-Mo fuel will increase the cycle length with a smaller number of fuel assemblies and allow more flexible back-end options for spent fuel due to of the reprocessibility of U-Mo. (author)

Top-MOX fuel solution: strategies, challenges, opportunities

International Nuclear Information System (INIS)

Breitenstein, P.; Vo Van, V.

2014-01-01

TOP-MOX is a nuclear fuel solution and product developed by AREVA and successfully implemented in Europe. It allows utilities burning plutonium (instead of enriched uranium) even when this plutonium is not stemming from own reprocessed used fuel - that is third party plutonium. The important challenges for utilities along with TOP-MOX implementation are legal/patrimonial Pu-ownership issues and general economical aspects. Available sponsorship of such plutonium permits UO2 competitive market prices. For new MOX customers licensing and technical aspects come along. Further AREVA proposes a flexible solution which is called 'TOP-MOX pre-cycling'. This involves making available third party plutonium for fuel fabrication and reactor use pending the utilities' final strategic fuel cycle decision. The paper gives insight into and analyses the impacts of allowing customers the implementation of a TOP-MOX program with focus on Pu-ownership, economics, technical and legal aspects as well as the impact on used MOX management and final waste management. (authors)

Assessment of chemical and material contamination in waste wood fuels--A case study ranging over nine years.

Science.gov (United States)

Edo, Mar; Björn, Erik; Persson, Per-Erik; Jansson, Stina

2016-03-01

The increased demand for waste wood (WW) as fuel in Swedish co-combustion facilities during the last years has increased the import of this material. Each country has different laws governing the use of chemicals and therefore the composition of the fuel will likely change when combining WW from different origins. To cope with this, enhanced knowledge is needed on WW composition and the performance of pre-treatment techniques for reduction of its contaminants. In this study, the chemical and physical characteristics of 500 WW samples collected at a co-combustion facility in Sweden between 2004 and 2013 were investigated to determine the variation of contaminant content over time. Multivariate data analysis was used for the interpretation of the data. The concentrations of all the studied contaminants varied widely between sampling occasions, demonstrating the highly variable composition of WW fuels. The efficiency of sieving as a pre-treatment measure to reduce the levels of contaminants was not sufficient, revealing that sieving should be used in combination with other pre-treatment methods. The results from this case study provide knowledge on waste wood composition that may benefit its management. This knowledge can be applied for selection of the most suitable pre-treatments to obtain high quality sustainable WW fuels. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Use of Water-Fuel Mixture in Diesel Engines at Fishing Vessels

Science.gov (United States)

Klyus, Oleg; Bezyukov, O.

2017-06-01

The paper presents the laboratory test results determining physical parameters of fuel mixture made up of petroleum diesel oil, rapeseed oil methyl esters (up to 20%) and water (up to 2.5%). The obtained parameters prove that adding bio-components (rapeseed oil methyl esters) and water to fuel does not result in deterioration of their physical and chemical properties and are comparable to base fuel parameters, namely petroleum diesel oil. The mixture was a subject of bench testing with the use of a self-ignition engine by means of pre-catalytic fuel treatment. The treatment process consisted in fuel - catalytically active material direct contact on the atomizer body. At the comparable operational parameters for the engine, the obtained exhaust gases opacity was lower up to 60% due to the preliminary fuel mixture treatment in relation to the factory-made fuel injection system using petroleum diesel oil.

USE OF WATER-FUEL MIXTURE IN DIESEL ENGINES AT FISHING VESSELS

Directory of Open Access Journals (Sweden)

Oleg KLYUS

2017-04-01

Full Text Available The paper presents the laboratory test results determining physical parameters of fuel mixture made up of petroleum diesel oil, rapeseed oil methyl esters (up to 20% and water (up to 2.5%. The obtained parameters prove that adding bio-components (rapeseed oil methyl esters and water to fuel does not result in deterioration of their physical and chemical properties and are comparable to base fuel parameters, namely petroleum diesel oil. The mixture was a subject of bench testing with the use of a self-ignition engine by means of pre-catalytic fuel treatment. The treatment process consisted in fuel – catalytically active material direct contact on the atomizer body. At the comparable operational parameters for the engine, the obtained exhaust gases opacity was lower up to 60% due to the preliminary fuel mixture treatment in relation to the factory-made fuel injection system using petroleum diesel oil.

On the behaviour of dissolved fission gases prior to transient testing of fuel pins

International Nuclear Information System (INIS)

Wood, M.H.; Matthews, J.R.

1978-10-01

The TREAT and CABRI series of reactor safety experiments on irradiated fuel require the transfer of fuel pins from the reactor in which the fuel has achieved some burn-up to the test facility. Subsequently, the fuel is restored to power in the test facility for some time before transient heating is initiated. Such pre-test manoeuvres, where the fuel is subjected to changes in the fission rate and temperature, may have important consequences for the fission gas behaviour during the transient experiment. The results of rate theory calculations are used to assess these effects. (author)

Development of tools to manage the operational monitoring and pre-design of the NPP-LV cycle

International Nuclear Information System (INIS)

Perusquia, R.; Arredondo S, C.; Hernandez M, J. L.; Montes T, J. L.; Castillo M, A.; Ortiz S, J. J.

2015-09-01

This paper presents the development of tools to facilitate the management so much, the operational monitoring of boiling water reactors (BWR) of the nuclear power plant of Laguna Verde (NPP-LV) through independent codes, and how to carry out the static calculations corresponding to process of optimized pre-design of the reference cycle next to current cycle. The progress and preliminary results obtained with the program SACal, developed at Instituto Nacional de Investigaciones Nucleares (ININ), central tool to achieve provide a management platform of the operational monitoring and pre-design of NPP-LV cycle are also described. The reached preliminary advances directed to get an Analysis center and automated design of fuel assembly cells are also presented, which together with centers or similar modules related with the fuel reloads form the key part to meet the targets set for the realization of a Management Platform of Nuclear Fuel of the NPP-LV. (Author)

Safety Culture in Pre-operational Phases of Nuclear Power Plant Projects

Energy Technology Data Exchange (ETDEWEB)

NONE

2012-09-15

An abundance of information exists on safety culture related to the operational phases of nuclear power plants; however, pre-operational phases present unique challenges. This publication focuses on safety culture during pre-operational phases that span the interval from before a decision to launch a nuclear power programme to first fuel load. It provides safety culture insights and focuses on eight generic issues: safety culture understanding; multicultural aspects; leadership; competencies and resource competition; management systems; learning and feedback; cultural assessments; and communication. Each issue is discussed in terms of: specific challenges; desired state; approaches and methods; and examples and resources. This publication will be of interest to newcomers and experienced individuals faced with the opportunities and challenges inherent in safety culture programmes aimed at pre-operational activities.

Safety Culture in Pre-operational Phases of Nuclear Power Plant Projects

International Nuclear Information System (INIS)

2012-01-01

An abundance of information exists on safety culture related to the operational phases of nuclear power plants; however, pre-operational phases present unique challenges. This publication focuses on safety culture during pre-operational phases that span the interval from before a decision to launch a nuclear power programme to first fuel load. It provides safety culture insights and focuses on eight generic issues: safety culture understanding; multicultural aspects; leadership; competencies and resource competition; management systems; learning and feedback; cultural assessments; and communication. Each issue is discussed in terms of: specific challenges; desired state; approaches and methods; and examples and resources. This publication will be of interest to newcomers and experienced individuals faced with the opportunities and challenges inherent in safety culture programmes aimed at pre-operational activities.

A statistical analysis of pellet-clad interaction failures in water reactor fuel

International Nuclear Information System (INIS)

McDonald, S.G.; Fardo, R.D.; Sipush, P.J.; Kaiser, R.S.

1981-01-01

The primary objective of the statistical analysis was to develop a mathematical function that would predict PCI fuel rod failures as a function of the imposed operating conditions. Linear discriminant analysis of data from both test and commercial reactors was performed. The initial data base used encompassed 713 data points (117 failures and 596 non-failures) representing a wide variety of water cooled reactor fuel (PWR, BWR, CANDU, and SGHWR). When applied on a best-estimate basis, the resulting function simultaneously predicts approximately 80 percent of both the failure and non-failure data correctly. One of the most significant predictions of the analysis is that relatively large changes in power can be tolerated when the pre-ramp irradiation power is low, but that only small changes in power can be tolerated when the pre-ramp irradiation power is high. However, it is also predicted that fuel rods irradiated at low power will fail at lower final powers than those irradiated at high powers. Other results of the analysis are that fuel rods with high clad operating temperatures can withstand larger power increases that fuel rods with low clad operating temperatures, and that burnup has only a minimal effect on PCI performance after levels of approximately 10000 MWD/MTU have been exceeded. These trends in PCI performance and the operating parameters selected are believed to be consistent with mechanistic considerations. Published PCI data indicate that BWR fuel usually operates at higher local powers and changes in power, lower clad temperatures, and higher local ramp rates than PWR fuel

Pre-test nondestructive examination data summary report on Turkey Point spent fuel assemblies D01, D04 and D06 for the climax-spent fuel test

International Nuclear Information System (INIS)

Davis, R.B.

1981-01-01

Fuel assembly sip testing conducted at Turkey Point and Battelle Columbus Laboratories (BCL) confirmed no leaking rods were among the thirteen fuel assemblies included in the Climax-Spent Fuel Test. A detailed nondestructive examination was conducted on three of the thirteen assemblies. Fuel assembly lengths and widths averaged 153.6 inches and 8.3 inches, respectively. The assemblies weighed 1459 +- 3 lbs. Total neutron flux measured at the fuel column midplane was 1.06 x 10 4 N/cm 2 /s with an average neutron energy of 1.4 MeV. Gamma dose rates were measured axially and vertically to the fuel column with maximum contact dose rate of 9.52 x 10 4 R/h. Twenty rods underwent detailed rod nondestructive examination. Rod lengths and weights averaged 152.5 inches and 6.82 lb, respectively. Spiral profilometry scans showed the maximum ovality for the twenty rods was 0.0105 inch with average rod diameters ranging from 0.4201 inch to 0.4211 inch. Extensive ridging from pellet cladding interaction was evident over most of the length on all rods. Gamma scan results showed no cesium peaking and no unusually large pellet to pellet gaps. Approximate 10% gamma activity depressions were found at the grid spacer locations. Several areas were identified as locations with an internal anomaly using eddy current results. Fifteen rods were reinserted into the three fuel assemblies at the completion of the nondestructive examinations. Five rods remained at BCL for destructive characterization

A Study on Fuel Estimation Algorithms for a Geostationary Communication & Broadcasting Satellite

Directory of Open Access Journals (Sweden)

Jong Won Eun

2000-12-01

Full Text Available It has been developed to calculate fuel budget for a geostationary communication and broadcasting satellite. It is quite essential that the pre-launch fuel budget estimation must account for the deterministic transfer and drift orbit maneuver requirements. After on-station, the calculation of satellite lifetime should be based on the estimation of remaining fuel and assessment of actual performance. These estimations step from the proper algorithms to produce the prediction of satellite lifetime. This paper concentrates on the fuel estimation method that was studied for calculation of the propellant budget by using the given algorithms. Applications of this method are discussed for a communication and broadcasting satellite.

Data sheets of fission product release experiments for light water reactor fuel, (2)

International Nuclear Information System (INIS)

Ishiwatari, Nasumi; Nagai, Hitoshi; Takeda, Tsuneo; Yamamoto, Katsumune; Nakazaki, Chozaburo.

1979-07-01

This is the second data sheets of fission products (FP) release experiments for light water reactor fuel. Results of five FP release experiments from the third to the seventh are presented: results of pre-examinations of UO 2 pellets, photographs of parts of fuel rod assemblies for irradiation and the assemblies, operational conditions of JMTR and OWL-1, variations of radioiodine-131 level in the main loop coolant during experimental periods, and representative results of post-irradiation examinations of respective fuel rods. (author)

Development of a computer program of fast calculation for the pre design of advanced nuclear fuel 10 x 10 for BWR type reactors

International Nuclear Information System (INIS)

Perusquia, R.; Montes, J.L.; Ortiz, J.J.

2005-01-01

In the National Institute of Nuclear Research (ININ) a methodology is developed to optimize the design of cells 10x10 of assemble fuels for reactors of water in boil or BWR. It was proposed a lineal calculation formula based on a coefficients matrix (of the change reason of the relative power due to changes in the enrichment of U-235) for estimate the relative powers by pin of a cell. With this it was developed the computer program of fast calculation named PreDiCeldas. The one which by means of a simple search algorithm allows to minimize the relative power peak maximum of cell or LPPF. This is achieved varying the distribution of U-235 inside the cell, maintaining in turn fixed its average enrichment. The accuracy in the estimation of the relative powers for pin is of the order from 1.9% when comparing it with results of the 'best estimate' HELIOS code. With the PreDiCeldas it was possible, at one minimum time of calculation, to re-design a reference cell diminishing the LPPF, to the beginning of the life, of 1.44 to a value of 1.31. With the cell design with low LPPF is sought to even design cycles but extensive that those reached at the moment in the BWR of the Laguna Verde Central. (Author)

Development of nuclear fuel rod inspection technique using ultrasonic resonance phenomenon

Energy Technology Data Exchange (ETDEWEB)

Choi, Myung Sun; Lee, Jong Po; Ju, Young Sang [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

1995-11-01

Acoustic resonance scattering from a nuclear fuel rod in water is analyzed. A new model for the background which is attributed to the interference of reflected wave and diffracted wave is found and here named {sup t}he inherent background{sup .} The resonance spectrum of a fuel rod is obtained by subtracting the inherent background from the scattered pressure. And also analyzed are the effect of material damping of cladding tube and pellet on the resonance spectrum of a fuel rod. The propagation characteristics of circumferential waves which cause the resonances of cladding tube is produced and the appropriate resonance modes for the application to the inspection of assembled fuel rods are selected. The resonance modes are experimentally measured for pre- and post-irradiated fuel rods and the validation of the fuel rod inspection using ultrasonic resonance phenomenon is examined. And thin ultrasonic sensors accessible into the narrow interval (about 2-3mm) between assembled fuel rods are designed and manufactured. 14 refs. (Author).

Thermal performance of a meso-scale liquid-fuel combustor

International Nuclear Information System (INIS)

Vijayan, V.; Gupta, A.K.

2011-01-01

Research highlights: → Demonstrated successful combustion of liquid fuel-air mixtures in a novel meso-scale combustor. → Flame quenching was eliminated using heat recirculation in a swiss roll type combustor that also extended the flammability limits. → Liquid fuel was rapidly vaporized with the use of hot narrow channel walls that eliminated the need of a fuel atomizer. → Maximum power density of the combustor was estimated to be about 8.5 GW/m3 and heat load in the range of 50-280W. → Overall efficiency of the combustor was estimated in the range of 12 to 20%. - Abstract: Combustion in small scale devices poses significant challenges due to the quenching of reactions from wall heat losses as well as the significantly reduced time available for mixing and combustion. In the case of liquid fuels there are additional challenges related to atomization, vaporization and mixing with the oxidant in the very short time-scale liquid-fuel combustor. The liquid fuel employed here is methanol with air as the oxidizer. The combustor was designed based on the heat recirculating concept wherein the incoming reactants are preheated by the combustion products through heat exchange occurring via combustor walls. The combustor was fabricated from Zirconium phosphate, a ceramic with very low thermal conductivity (0.8 W m -1 K -1 ). The combustor had rectangular shaped double spiral geometry with combustion chamber in the center of the spiral formed by inlet and exhaust channels. Methanol and air were introduced immediately upstream at inlet of the combustor. The preheated walls of the inlet channel also act as a pre-vaporizer for liquid fuel which vaporizes the liquid fuel and then mixes with air prior to the fuel-air mixture reaching the combustion chamber. Rapid pre-vaporization of the liquid fuel by the hot narrow channel walls eliminated the necessity for a fuel atomizer. Self-sustained combustion of methanol-air was achieved in a chamber volume as small as 32.6 mm 3

Increase in the boiler's performance in terms of the acid dew point temperature: Environmental advantages of replacing fuels

Energy Technology Data Exchange (ETDEWEB)

Blanco, J.M.; Pena, F. [Dpto. Maquinas y Motores Termicos, Escuela Tecnica Superior de Ingenieria, Universidad del Pais Vasco/E.H.U., Alameda de Urquijo s/n (48013) Bilbao (Spain)

2008-05-15

The aim of air pre-heaters is to raise the temperature of the combustion air in boilers, using heat recovered from the power plant combustion gases. On the one hand, this paper compares the effects of the acid dew point temperature (ADT) on pre-heaters in a reference thermal power plant for two types of fuel, ''fuel No. 2'' and ''low sulphur fuel'' respectively and on the other hand, it shows how a changeover to this latter fuel would increase the useful lifetime of this equipment, reducing this way cost of maintenance due to the considerable decrease in the area exposed to ADT with the subsequent increase in the boiler's performance. (author)

Determination of the fuel component in the cost price of the energy production in NPP

International Nuclear Information System (INIS)

Lakov, M.; Velev, V.

1997-01-01

An approach is proposed for the determination of the fuel component in the cost price of the nuclear units production with regards of the difference between the time of the fuel consumption and the energy production. This method gives the opportunity for fuel consumption prognostication, as well as an optimization of both short and long term fueling regimes. This approach permits current update of the economic conditions and the pre-history of the investments. It can be used both for the determination of the fuel component and the full cost price of the energy production in NPPs.(author)

CANDU-6 fuel optimization for advanced cycles

Energy Technology Data Exchange (ETDEWEB)

St-Aubin, Emmanuel, E-mail: emmanuel.st-aubin@polymtl.ca; Marleau, Guy, E-mail: guy.marleau@polymtl.ca

2015-11-15

Highlights: • New fuel selection process proposed for advanced CANDU cycles. • Full core time-average CANDU modeling with independent refueling and burnup zones. • New time-average fuel optimization method used for discrete on-power refueling. • Performance metrics evaluated for thorium-uranium and thorium-DUPIC cycles. - Abstract: We implement a selection process based on DRAGON and DONJON simulations to identify interesting thorium fuel cycles driven by low-enriched uranium or DUPIC dioxide fuels for CANDU-6 reactors. We also develop a fuel management optimization method based on the physics of discrete on-power refueling and the time-average approach to maximize the economical advantages of the candidates that have been pre-selected using a corrected infinite lattice model. Credible instantaneous states are also defined using a channel age model and simulated to quantify the hot spots amplitude and the departure from criticality with fixed reactivity devices. For the most promising fuels identified using coarse models, optimized 2D cell and 3D reactivity device supercell DRAGON models are then used to generate accurate reactor databases at low computational cost. The application of the selection process to different cycles demonstrates the efficiency of our procedure in identifying the most interesting fuel compositions and refueling options for a CANDU reactor. The results show that using our optimization method one can obtain fuels that achieve a high average exit burnup while respecting the reference cycle safety limits.

Environmentally safe separation and pre-concentration of rhodium and ruthenium from spent nuclear fuel using mixed-micelle cloud point extraction and determination by ICP-MS

International Nuclear Information System (INIS)

Ranjit, M.; Meeravali, N.N.; Kumar, S.J.

2010-01-01

Full text: Recently, spend nuclear fuel waste of thermal and fast reactors are emerging as an alternative valuable resource for Rh, Ru and Pd. In addition, its presence causes the difficulty in the vitrification process. Hence, its safe extraction from these wastes has to be carried out by using the environmental friendly extraction procedure. In this study, we have reported the simple mixed-micelle cloud point extraction (MM-CPE) procedure for separation as well as pre-concentration of Rh, Ru and Pd. This MM-CPE is carried out preliminarily from aqueous chloride medium with Aliquat-336/Triton X-114 mixed-micelles in the absence and presence of tin(II) chloride. In presence of chloride medium alone, only Pd get extracted quantitatively, while extraction of Rh and Ru are negligible. In presence of tin chloride, the extraction of Rh and Ru increases and becomes quantitative, without affecting the extraction of Pd. The MM-CPE conditions are optimized under influence of variables such as HCI, Aliquat-336, Triton X-114 and tin chloride concentrations and incubation time and temperature. Under the optimized conditions, the accuracy of the procedure is verified by using recovery study carried out from real water samples. This work is under progress to apply real nuclear fuel waste samples

Axial transport of fission gas in LWR fuel rods

International Nuclear Information System (INIS)

Kinoshita, M.

1983-01-01

With regard to fission gas transportation inside the fuel rod, the following three mechanisms are important: (1) a localized and time dependent fission gas release from UO 2 fuel to pellet/clad gap, (2) the consequent gas pressure difference between the gap and the plenum, and (3) the inter-diffusion of initially filled Helium and released fission gas such as Xenon. Among these three mechanisms, the 2nd mechanism would result in the one dimensional flow through P/C gap in the axial direction, while the 3rd would average the local fission gas concentration difference. In this paper, an attempt was made to develop a computerized model, LINUS (LINear flow and diffusion under Un-Steady condition) describing the above two mechanisms, items (2) and (3). The item (1) is treated as an input. The code was applied to analyse short length experimental fuel rods and long length commercial fuel rods. The calculated time evolution of Xe concentration along the fuel column shows that the dilution rate of Xe in commercial fuel rods is much slower than that in short experimental fuel rods. Some other sensitivity studies, such as the effect of pre-pressurization, are also presented. (author)

Cost-Effective Fuel Treatment Planning

Science.gov (United States)

Kreitler, J.; Thompson, M.; Vaillant, N.

2014-12-01

The cost of fighting large wildland fires in the western United States has grown dramatically over the past decade. This trend will likely continue with growth of the WUI into fire prone ecosystems, dangerous fuel conditions from decades of fire suppression, and a potentially increasing effect from prolonged drought and climate change. Fuel treatments are often considered the primary pre-fire mechanism to reduce the exposure of values at risk to wildland fire, and a growing suite of fire models and tools are employed to prioritize where treatments could mitigate wildland fire damages. Assessments using the likelihood and consequence of fire are critical because funds are insufficient to reduce risk on all lands needing treatment, therefore prioritization is required to maximize the effectiveness of fuel treatment budgets. Cost-effectiveness, doing the most good per dollar, would seem to be an important fuel treatment metric, yet studies or plans that prioritize fuel treatments using costs or cost-effectiveness measures are absent from the literature. Therefore, to explore the effect of using costs in fuel treatment planning we test four prioritization algorithms designed to reduce risk in a case study examining fuel treatments on the Sisters Ranger District of central Oregon. For benefits we model sediment retention and standing biomass, and measure the effectiveness of each algorithm by comparing the differences among treatment and no treat alternative scenarios. Our objective is to maximize the averted loss of net benefits subject to a representative fuel treatment budget. We model costs across the study landscape using the My Fuel Treatment Planner software, tree list data, local mill prices, and GIS-measured site characteristics. We use fire simulations to generate burn probabilities, and estimate fire intensity as conditional flame length at each pixel. Two prioritization algorithms target treatments based on cost-effectiveness and show improvements over those

Forest biomass and tree planting for fossil fuel offsets in the Colorado Front Range

Science.gov (United States)

Mike A. Battaglia; Kellen Nelson; Dan Kashian; Michael G. Ryan

2010-01-01

This study estimates the amount of carbon available for removal in fuel reduction and reforestation treatments in montane forests of the Colorado Front Range based on site productivity, pre-treatment basal area, and planting density. Thinning dense stands will yield the greatest offsets for biomass fuel. However, this will also yield the greatest carbon losses, if the...

Power generation costs for alternate reactor fuel cycles

International Nuclear Information System (INIS)

Smolen, G.R.; Delene, J.G.

1980-09-01

The total electric generating costs at the power plant busbar are estimated for various nuclear reactor fuel cycles which may be considered for power generation in the future. The reactor systems include pressurized water reactors (PWR), heavy-water reactors (HWR), high-temperature gas cooled reactors (HTGR), liquid-metal fast breeder reactors (LMFBR), light-water pre-breeder and breeder reactors (LWPR, LWBR), and a fast mixed spectrum reactor (FMSR). Fuel cycles include once-through, uranium-only recycle, and full recycle of the uranium and plutonium in the spent fuel assemblies. The U 3 O 8 price for economic transition from once-through LWR fuel cycles to both PWR recycle and LMFBR systems is estimated. Electric power generation costs were determined both for a reference set of unit cost parameters and for a range of uncertainty in these parameters. In addition, cost sensitivity parameters are provided so that independent estimations can be made for alternate cost assumptions

CANDU fuel behaviour under LOCA conditions

International Nuclear Information System (INIS)

Kohn, E.

1989-07-01

This report summarizes the current understanding of CANDU fuel-element behaviour under loss-of-coolant (LOCA) accidents. It focuses on a key in-reactor verification experiment conducted at Idaho National Engineering Laboratory (INEL) and on three Canadian in-reactor tests. The in-reactor data, and the considerable body of supporting information developed from out-reactor tests, support the general conclusion that CANDU fuel behaviour during LOCA transients is well understood. Four elements of 37-element CANDU fuel-bundle design were tested under conditions typical of a large-break LOCA blowdown in a CANDU reactor. The purpose of the test was to confirm our current understanding of fuel behaviour under loss-of-coolant accident blowdown conditions. The test also provided data for comparison with predictions made with the steady-state and transient fuel-element performance codes ELESIM and ELOCA. Key components of typical LOCA transients were incorporated in the test: namely, a rapid depressurization rate of the hot coolant, a simultaneous power increase before decreasing to decay values (a power pulse), and prototype fuel element under pre-transient power and burnup conditions. The test was successfully completed in the Power Burst Facility (PBF) reactor at INEL under contract to Ontario Hydro and AECL. The three CANDU Owners Group LOCA tests performed at Chalk River Nuclear Laboratories measured both the thermal-mechanical response and fission-gas release resulting from exposure to a LOCA transient. Results from these three tests provided further confirmation that the behaviour of the fuel under LOCA conditions is understood

BWR Spent Nuclear Fuel Integrity Research and Development Survey for UKABWR Spent Fuel Interim Storage

Energy Technology Data Exchange (ETDEWEB)

Bevard, Bruce Balkcom [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Mertyurek, Ugur [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Belles, Randy [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Scaglione, John M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2015-10-01

The objective of this report is to identify issues and support documentation and identify and detail existing research on spent fuel dry storage; provide information to support potential R&D for the UKABWR (United Kingdom Advanced Boiling Water Reactor) Spent Fuel Interim Storage (SFIS) Pre-Construction Safety Report; and support development of answers to questions developed by the regulator. Where there are gaps or insufficient data, Oak Ridge National Laboratory (ORNL) has summarized the research planned to provide the necessary data along with the schedule for the research, if known. Spent nuclear fuel (SNF) from nuclear power plants has historically been stored on site (wet) in spent fuel pools pending ultimate disposition. Nuclear power users (countries, utilities, vendors) are developing a suite of options and set of supporting analyses that will enable future informed choices about how best to manage these materials. As part of that effort, they are beginning to lay the groundwork for implementing longer-term interim storage of the SNF and the Greater Than Class C (CTCC) waste (dry). Deploying dry storage will require a number of technical issues to be addressed. For the past 4-5 years, ORNL has been supporting the U.S. Department of Energy (DOE) in identifying these key technical issues, managing the collection of data to be used in issue resolution, and identifying gaps in the needed data. During this effort, ORNL subject matter experts (SMEs) have become expert in understanding what information is publicly available and what gaps in data remain. To ensure the safety of the spent fuel under normal and frequent conditions of wet and subsequent dry storage, intact fuel must be shown to: 1.Maintain fuel cladding integrity; 2.Maintain its geometry for cooling, shielding, and subcriticality; 3.Maintain retrievability, and damaged fuel with pinhole or hairline cracks must be shown not to degrade further. Where PWR (pressurized water reactor) information is

IFPE/IFA-533, Fuel Thermal Behaviour at High Burnup, Halden Reactor

International Nuclear Information System (INIS)

Gyori, Cs.; Turnbull, J.A.

1997-01-01

Description: After twelve years irradiation in the Halden Boiling Water Reactor two fuel rods (Rod 807 and Rod 808) were re-instrumented with fuel centre thermocouples and reloaded into the reactor in order to investigate the fuel thermal behaviour at high burnup. The fuel rods were pre-irradiated with four other rods in the upper cluster of IFA-409 (IFA=Instrumented Fuel Assembly) from May 1973 to June 1985. After base irradiation the four neighbouring rods were re-instrumented with pressure transducers and ramp tested in IFA-535.5 and IFA-535.6 providing useful data about fission gas release (FGR) presented in the Fuel Performance Database as well (Ref. 1). The two rods re-instrumented with fuel centre thermocouples have been irradiated as IFA-533.2 from April 1992. As the irradiation history of IFA-533.2 in the first months was very similar to the history of the ramp tests, the fuel temperature and FGR data measured in the different IFAs can complement each other, although the fuel-cladding gap sizes were slightly different and due to re-instrumentation the internal gas conditions were also dissimilar

Solar pre-heating of water for steam generation in the friendship textile mill

International Nuclear Information System (INIS)

Sid -Ahmed, M.O.; Hussien, T.

1994-01-01

The technology of solar water heating is simple and can be used for pre-heating of water entering a boiler. In this paper the economics of solar pre-heating of water was calculated. The calculations were based on the performance and cost of a locally-made flat plate collector, and the performance and fuel consumption of a boiler in a textile mill. The results showed that a collector area of about 800 meter square with initial cost of about LS 5,000,000, could save annually about 130 tons of furnace oil. ( Author )

Some observations on the pre-boilover burning of a slick of oil on water

International Nuclear Information System (INIS)

Garo, J.P.; Vantelon, J.P.; Gandhi, S.; Torero, J.L.

1996-01-01

The effects of burning oil in water were investigated to establish a systematic methodology for ignition of oil-spills. A simple heat conduction model was used to describe the pre-boil over burning rate of crude oil and heating oil. Results from the model were compared with experimental pool burning test results. The calculations agreed well with experiments conducted with crude oil and heating oil. Theoretical expressions were also successfully correlated with emulsified and weathered crude. The parameters considered for the calculations included the fuel layer thickness, the weathering level and the percentage of water emulsified in the fuel. The model accurately described the regression rate for fuel layers thicker than 8 mm. 22 refs., 1 tab., 13 figs

Wildfire fuel harvesting and resultant biomass utilization using a cut-to-length/small chipper system

Science.gov (United States)

M. Chad Bolding; Bobby L. Lanford

2005-01-01

Currently, there is a lack of information concerning mechanical forest fuel reduction. This study examined and measured the feasibility of ground-based mechanical harvesting to reduce forest fuel buildup and produce energywood. Cut-to-length (CTL) harvesting coupled with a small in-woods chipper provided a low impact way to harvest pre-commercial trees and tops along...

Measurements relating fire radiative energy density and surface fuel consumption - RxCADRE 2011 and 2012

Science.gov (United States)

Andrew T. Hudak; Matthew B. Dickinson; Benjamin C. Bright; Robert L. Kremens; E. Louise Loudermilk; Joseph J. O' Brien; Benjamin S. Hornsby; Roger D. Ottmar

2016-01-01

Small-scale experiments have demonstrated that fire radiative energy is linearly related to fuel combusted but such a relationship has not been shown at the landscape level of prescribed fires. This paper presents field and remotely sensed measures of pre-fire fuel loads, consumption, fire radiative energy density (FRED) and fire radiative power flux density (FRFD),...

New polymer electrolytes for low temperature fuel cells

Energy Technology Data Exchange (ETDEWEB)

Sundholm, F.; Elomaa, M.; Ennari, J.; Hietala, S.; Paronen, M. [Univ. of Helsinki (Finland). Lab. of Polymer Chemistry

1998-12-31

Proton conducting polymer membranes for demanding applications, such as low temperature fuel cells, have been synthesised and characterised. Pre-irradiation methods are used to introduce sulfonic acid groups, directly or using polystyrene grafting, in stable, preformed polymer films. The membranes produced in this work show promise for the development of cost-effective, highly conducting membranes. (orig.)

Integral reactor system and method for fuel cells

Science.gov (United States)

Fernandes, Neil Edward; Brown, Michael S; Cheekatamarla, Praveen; Deng, Thomas; Dimitrakopoulos, James; Litka, Anthony F

2013-11-19

A reactor system is integrated internally within an anode-side cavity of a fuel cell. The reactor system is configured to convert hydrocarbons to smaller species while mitigating the lower production of solid carbon. The reactor system may incorporate one or more of a pre-reforming section, an anode exhaust gas recirculation device, and a reforming section.

Effects of bolt pre-loading variations on performance of GDL in a bolted PEMFC by 3-D FEM analysis

International Nuclear Information System (INIS)

Chien, Chi-Hui; Hu, Yao-Lun; Su, Ting-Hsuan; Liu, Hsuan-Ting; Wang, Chung-Ting; Yang, Ping-Feng; Lu, Ying-Xu

2016-01-01

This study numerically investigated the effects of different bolt pre-loadings on the performance of the gas diffusion layer (GDL) in a bolted proton exchange membrane fuel cell (PEMFC). Firstly, a complete three-dimensional finite element model of a PEMFC bolted by 12 bolts with a reactive area of 5 cm by 5 cm was established using the commercial software SolidWorks. Then, a pre-loading of 1 MPa to 7 MPa on each bolt was applied, increasing in increments 1 MPa, and the corresponding deformation and stress fields of each component of the fuel cell were obtained using the commercial software ANSYS 15.0/Workbench. Finally, the effects of the bolt pre-loading variations on the performance of the GDL were discussed. The results showed that the compression ratio of the GDL increased linearly with the magnitude of bolt pre-loading, and improving the performance of the GDL. However, when the pre-loading on each bolt reached 7 MPa, the compression ratio exceeded 15%, degrading the efficiency of the PEMFC. Also, by comparing the relationships between bolt pre-loading and conductivity and porosity of GDL, in order to obtain the maximum performance of GDL, an optimum value of 4 MPa for bolt preloading was recommended. - Highlights: • Effect of bolt pre-loading on deformations is more serious than that of thermal loading. • Bolt pre-loading improves compression ratio of GDL. • For obtaining a maximum performance of GDL, 4 MPa of bolt pre-loading was recommended. • Flow channel volume reduced by bolt pre-loading degrades the efficiency of PEMFC.

The advanced neutron source three-element-core fuel grading

International Nuclear Information System (INIS)

Gehin, J.C.

1995-01-01

The proposed Advanced Neutron Source (ANS) pre-conceptual design consists of a two-element 330 MW f nuclear reactor fueled with highly-enriched uranium and is cooled, moderated, and reflected with heavy water. Recently, the ANS design has been changed to a three-element configuration in order to permit a reduction of the enrichment, if required, while maintaining or improving the thermal-hydraulic margins. The core consists of three annular fuel elements composed of involute-shaped fuel plates. Each fuel plate has a thickness of 1.27 mm and consists of a fuel meat region Of U 3 Si 2 -Al (50% enriched in one case that was proposed) and an aluminum filler region between aluminum cladding. The individual plates are separated by a 1.27 mm coolant channel. The three element core has a fuel loading of 31 kg of 235 U which is sufficient for a 17-day fuel cycle. The goal in obtaining a new fuel grading is to maximize important temperature margins. The limits imposed axe: (1) Limit the temperature drop over the cladding oxide layer to less than 119 degrees C to avoid oxide spallation. (2) Limit the fuel centerline temperature to less than 400 degrees C to avoid fuel damage. (3) Limit the cladding wall temperature to less than the coolant. incipient-boiling temperature to avoid coolant boiling. Other thermal hydraulic conditions, such as critical heat flux, are also considered

Autoignition characteristics of laminar lifted jet flames of pre-vaporized iso-octane in heated coflow air

KAUST Repository

Al-Noman, Saeed M.; Choi, Sang Kyu; Chung, Suk-Ho

2015-01-01

The stabilization characteristics of laminar non-premixed jet flames of pre-vaporized iso-octane, one of the primary reference fuels for octane rating, have been studied experimentally in heated coflow air. Non-autoignited and autoignited lifted

Transportation fuel from plastic: Two cases of study.

Science.gov (United States)

Faussone, Gian Claudio

2018-03-01

Synthesis of liquid fuels from waste is a promising pathway for reducing the carbon footprint of transportation industry and optimizing waste management towards zero landfilling. The study of commercial plants that conduct pyrolysis of plastics from post-consumer recycled materials and directly mine from old landfills without any pre-treatment has revealed two cases that show the feasibility of manufacturing transportation fuels via these methods. Pyrolysis oil, consisting of almost 26% hydrocarbons within the gasoline range and almost 70% within the diesel range, is upgraded to transportation fuel in the existing refinery. A batch operating plant is able to deliver relatively good quality pyrolysis oil from post-consumer plastic waste, owing to the catalyst employed. Simple distillation was also evaluated as an alternative and cheaper upgrading process into transportation fuels, meeting EN590 diesel and ISO8217 marine fuel standards. Even though the two installations are outside the European Union, they represent good examples of the "circular economy" concept envisaged by the European Union via its ambitious "Circular Economy Package [1]", providing real world data for comparison with other experimental and lab results. Copyright © 2017 Elsevier Ltd. All rights reserved.

A microfluidic direct formate fuel cell on paper.

Science.gov (United States)

Copenhaver, Thomas S; Purohit, Krutarth H; Domalaon, Kryls; Pham, Linda; Burgess, Brianna J; Manorothkul, Natalie; Galvan, Vicente; Sotez, Samantha; Gomez, Frank A; Haan, John L

2015-08-01

We describe the first direct formate fuel cell on a paper microfluidic platform. In traditional membrane-less microfluidic fuel cells (MFCs), external pumping consumes power produced by the fuel cell in order to maintain co-laminar flow of the anode stream and oxidant stream to prevent mixing. However, in paper microfluidics, capillary action drives flow while minimizing stream mixing. In this work, we demonstrate a paper MFC that uses formate and hydrogen peroxide as the anode fuel and cathode oxidant, respectively. Using these materials we achieve a maximum power density of nearly 2.5 mW/mg Pd. In a series configuration, our MFC achieves an open circuit voltage just over 1 V, and in a parallel configuration, short circuit of 20 mA absolute current. We also demonstrate that the MFC does not require continuous flow of fuel and oxidant to produce power. We found that we can pre-saturate the materials on the paper, stop the electrolyte flow, and still produce approximately 0.5 V for 15 min. This type of paper MFC has potential applications in point-of-care diagnostic devices and other electrochemical sensors. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Analysis of fuel pin behavior under slow-ramp type transient overpower condition by using the fuel performance evaluation code 'FEMAXI-FBR'

International Nuclear Information System (INIS)

Tsuboi, Yasushi; Ninokata, Hisashi; Endo, Hiroshi; Ishizu, Tomoko; Tatewaki, Isao; Saito, Hiroaki

2012-01-01

FEMAXI-FBR has been developed as the one module of the core disruptive accident analysis code 'ASTERIA-FBR' in order to evaluate the mixed oxide (MOX) fuel performance under steady, transient and accident conditions of fast reactors consistently. On the basis of light water reactor (LWR) fuel performance evaluation code 'FEMAXI-6', FEMAXI-FBR develops specific models for the fast reactor fuel performance, such as restructuring, material migration during steady state and transient, melting cavity formation and pressure during accident, so that it can evaluate the fuel failure during accident. The analysis of test pin with slow transient over power test of CABRI-2 program was conducted from steady to transient. The test pin was pre-irradiated and tested under transient overpower with several % P 0 /s (P 0 : steady state power) of the power rate. Analysis results of the gas release ratio, pin failure time, and fuel melt radius were compared to measured values. The analysis results of the steady and transient performances were also compared with the measured values. The compared performances are gas release ratio, fuel restructuring for steady state and linear power and melt radius at failure during transient. This analysis result reproduces the measured value. It was concluded that FEMAXI-FBR is effective to evaluate fast reactor fuel performances from steady state to accident conditions. (author)

Economics of Direct Hydrogen Polymer Electrolyte Membrane Fuel Cell Systems

Energy Technology Data Exchange (ETDEWEB)

Mahadevan, Kathyayani

2011-10-04

Battelle's Economic Analysis of PEM Fuel Cell Systems project was initiated in 2003 to evaluate the technology and markets that are near-term and potentially could support the transition to fuel cells in automotive markets. The objective of Battelle?s project was to assist the DOE in developing fuel cell systems for pre-automotive applications by analyzing the technical, economic, and market drivers of direct hydrogen PEM fuel cell adoption. The project was executed over a 6-year period (2003 to 2010) and a variety of analyses were completed in that period. The analyses presented in the final report include: Commercialization scenarios for stationary generation through 2015 (2004); Stakeholder feedback on technology status and performance status of fuel cell systems (2004); Development of manufacturing costs of stationary PEM fuel cell systems for backup power markets (2004); Identification of near-term and mid-term markets for PEM fuel cells (2006); Development of the value proposition and market opportunity of PEM fuel cells in near-term markets by assessing the lifecycle cost of PEM fuel cells as compared to conventional alternatives used in the marketplace and modeling market penetration (2006); Development of the value proposition of PEM fuel cells in government markets (2007); Development of the value proposition and opportunity for large fuel cell system application at data centers and wastewater treatment plants (2008); Update of the manufacturing costs of PEM fuel cells for backup power applications (2009).

The 3R anthracite clean coal technology: Economical conversion of brown coal to anthracite type clean coal by low temperature carbonization pre-treatment process

Directory of Open Access Journals (Sweden)

Someus Edward

2006-01-01

Full Text Available The preventive pre-treatment of low grade solid fuels is safer, faster, better, and less costly vs. the "end-of-the-pipe" post treatment solutions. The "3R" (Recycle-Reduce-Reuse integrated environment control technology provides preventive pre-treatment of low grade solid fuels, such as brown coal and contaminated solid fuels to achieve high grade cleansed fuels with anthracite and coke comparable quality. The goal of the 3R technology is to provide cost efficient and environmentally sustainable solutions by preventive pre-treatment means for extended operations of the solid fuel combustion power plants with capacity up to 300 MWe power capacities. The 3R Anthracite Clean Coal end product and technology may advantageously be integrated to the oxyfuel-oxy-firing, Foster Wheeler anthracite arc-fired utility type boiler and Heat Pipe Reformer technologies in combination with CO2 capture and storage programs. The 3R technology is patented original solution. Advantages. Feedstock flexibility: application of pre-treated multi fuels from wider fuel selection and availability. Improved burning efficiency. Technology flexibility: efficient and advantageous inter-link to proven boiler technologies, such as oxyfuel and arcfired boilers. Near zero pollutants for hazardous-air-pollutants: preventive separation of halogens and heavy metals into small volume streams prior utilization of cleansed fuels. >97% organic sulphur removal achieved by the 3R thermal pre-treatment process. Integrated carbon capture and storage (CCS programs: the introduction of monolitic GHG gas is improving storage safety. The 3R technology offers significant improvements for the GHG CCS conditions. Cost reduction: decrease of overall production costs when all real costs are calculated. Improved safety: application of preventive measures. For pre-treatment a specific purpose designed, developed, and patented pyrolysis technology used, consisting of a horizontally arranged externally

Designing the microturbine engine for waste-derived fuels.

Science.gov (United States)

Seljak, Tine; Katrašnik, Tomaž

2016-01-01

Presented paper deals with adaptation procedure of a microturbine (MGT) for exploitation of refuse derived fuels (RDF). RDF often possess significantly different properties than conventional fuels and usually require at least some adaptations of internal combustion systems to obtain full functionality. With the methodology, developed in the paper it is possible to evaluate the extent of required adaptations by performing a thorough analysis of fuel combustion properties in a dedicated experimental rig suitable for testing of wide-variety of waste and biomass derived fuels. In the first part key turbine components are analyzed followed by cause and effect analysis of interaction between different fuel properties and design parameters of the components. The data are then used to build a dedicated test system where two fuels with diametric physical and chemical properties are tested - liquefied biomass waste (LW) and waste tire pyrolysis oil (TPO). The analysis suggests that exploitation of LW requires higher complexity of target MGT system as stable combustion can be achieved only with regenerative thermodynamic cycle, high fuel preheat temperatures and optimized fuel injection nozzle. Contrary, TPO requires less complex MGT design and sufficient operational stability is achieved already with simple cycle MGT and conventional fuel system. The presented approach of testing can significantly reduce the extent and cost of required adaptations of commercial system as pre-selection procedure of suitable MGT is done in developed test system. The obtained data can at the same time serve as an input for fine-tuning the processes for RDF production. Copyright © 2015. Published by Elsevier Ltd.

Alkylation and pre-organization of diglycolamide ligands on flexible platforms for nuclear waste treatment

NARCIS (Netherlands)

Leoncini, Andrea

2017-01-01

The research topic of this thesis concerns the synthesis and evaluation of new diglycolamide (DGA) ligands for the extraction and (potential) separation of actinide and lanthanide ions from bulk spent nuclear fuel. This work was aimed at the development of new pre-organised ligands with improved

Conversion of Mixed Plastic Wastes (High Density Polyethylene and Polypropylene) into Liquid Fuel

International Nuclear Information System (INIS)

Chaw Su Su Hmwe; Tint Tint Kywe; Moe Moe Kyaw

2010-12-01

In this study, mixed plastic wastes were converted into liquid fuels. Mixed plastic wastes used were high density polyethylene (HDPE) and polypropylene (PP). The pyrolysis of mixed plastic waste to liquid fuel was carried out with and without prepared zeolite catalyst.The catalyst was characterized by X-ray Diffraction (XRD). This catalyst was pre-treated for activation. The experiments were carried out at temperature range of 350-410C.Physical properties (density, kinematic, viscosity,refractive index)of prepared liquid fuel samples were measured. From this study, yields of liquid fuel and gas fuel were found to be 41-64% and 15-35% respectively. As for by products, char was obtained as the yield percentages from 9 to 14% and wax (yield% - 1 to 14) was formed during pyrolysis.

Calibration of the enigma code for Finnish reactor fuel with support from experimental irradiations

Energy Technology Data Exchange (ETDEWEB)

Kelppe, S; Ranta-Puska, K [VTT Energy, Jyvaeskylae (Finland)

1997-08-01

Assessment by VTT of the ENIGMA fuel performance code, the original version by Nuclear Electric plc of the UK amended by a set of WWER specific materials correlations, is described. The given examples of results include analyses for BWR 9 x 9 fuel, BWR fuel irradiated in the reinstrumented test of an international Riso project, pre-characterized commercial WWER fuel irradiated in Loviisa reactor in Finland, and instrumented WWER test fuel irradiations in the MR reactor in Russia. The effects of power uncertainty and some model parameters are discussed. Considering the fact that the described cases all mean prototypic application of the code, the results are well encouraging. The importance of the accuracy in temperature calculations is emphasized. (author). 2 refs, 12 figs, 1 tab.

Investigation on the effects of pilot injection on low temperature combustion in high-speed diesel engine fueled with n-butanol–diesel blends

International Nuclear Information System (INIS)

Huang, Haozhong; Liu, Qingsheng; Yang, Ruzhi; Zhu, Tianru; Zhao, Ruiqing; Wang, Yaodong

2015-01-01

Highlights: • The effects of pre-injected timing and pre-injected mass were studied in CI engine. • The addition of n-butanol consumed OH free radicals, which delayed the ignition time. • With the increase of n-butanol, the BSFC and MPRR increased, NO_x and soot decreased. • With the advance of pilot injection timing, the BSFC increased, NO_x and soot decreased. • With the increase of pilot injection mass, NO_x increased, soot decreased then increased. - Abstract: The effect of pilot injection timing and pilot injection mass on combustion and emission characteristics under medium exhaust gas recirculation (EGR (25%)) condition were experimentally investigated in high-speed diesel engine. Diesel fuel (B0), two blends of butanol and diesel fuel denoted as B20 (20% butanol and 80% diesel in volume), and B30 (30% butanol and 70% diesel in volume) were tested. The results show that, for all fuels, when advancing the pilot injection timing, the peak value of heat release rate decreases for pre-injection fuel, but increases slightly for the main-injection fuel. Moreover, the in-cylinder pressure peak value reduces with the rise of maximum pressure rise rate (MPRR), while NO_x and soot emissions reduce. Increasing the pilot injection fuel mass, the peak value of heat release rate for pre-injected fuel increases, but for the main-injection, the peak descends, and the in-cylinder pressure peak value and NO_x emissions increase, while soot emission decreases at first and then increases. Blending n-butanol in diesel improves soot emissions. When pilot injection is adopted, the increase of n-butanol ratio causes the MPRR increasing and the crank angle location for 50% cumulative heat release (CA50) advancing, as well as NO_x and soot emissions decreasing. The simulation of the combustion of n-butanol–diesel fuel blends, which was based on the n-heptane–n-butanol–PAH–toluene mixing mechanism, demonstrated that the addition of n-butanol consumed OH free radicals

Dry refabrication technology development of spent nuclear fuel

International Nuclear Information System (INIS)

Park, Geun Il; Lee, J. W.; Song, K. C.

2012-04-01

Key technologies highly applicable to the development of advanced nuclear fuel cycle for the spent fuel recycling were developed using spent fuel and simulated spent fuel (SIMFUEL). In the frame work of dry process oxide products fabrication and the property characteristics of dry process products, hot cell experimental data for decladding, powdering and oxide product fabrication from low and high burnup spent fuel have been produced, basic technology for fabrication of spent fuel standard material has been developed, and remotely modulated welding equipment has been designed and fabricated. Also, fabrication technology of simulated dry process products was established and property models were developed based on reproducible property measurement data. In the development of head-end technology for dry refabrication of spent nuclear fuel and key technologies for volume reduction of head-end process waste which are essential in back-end fuel cycle field including pyro-processing, advanced head-end unit process technology development includes the establishment of experimental conditions for synthesis of porous fuel particles using a granulating furnace and for preparation of UO2 pellets, and fabrication and performance demonstration of engineering scale equipment for off-gas treatment of semi-volatile nuclides, and development of phosphate ceramic technology for immobilization of used filters. Radioactivation characterization and treatment equipment design of metal wastes from pretreatment process was conducted, and preliminary experiments of chlorination/electrorefining techniques for the treatment of hull wastes were performed. Based on the verification of the key technologies for head-end process via the hot-cell tests using spent nuclear fuel, pre-conceptual design for the head-end equipments was performed

Dry refabrication technology development of spent nuclear fuel

Energy Technology Data Exchange (ETDEWEB)

Park, Geun Il; Lee, J. W.; Song, K. C.; and others

2012-04-15

Key technologies highly applicable to the development of advanced nuclear fuel cycle for the spent fuel recycling were developed using spent fuel and simulated spent fuel (SIMFUEL). In the frame work of dry process oxide products fabrication and the property characteristics of dry process products, hot cell experimental data for decladding, powdering and oxide product fabrication from low and high burnup spent fuel have been produced, basic technology for fabrication of spent fuel standard material has been developed, and remotely modulated welding equipment has been designed and fabricated. Also, fabrication technology of simulated dry process products was established and property models were developed based on reproducible property measurement data. In the development of head-end technology for dry refabrication of spent nuclear fuel and key technologies for volume reduction of head-end process waste which are essential in back-end fuel cycle field including pyro-processing, advanced head-end unit process technology development includes the establishment of experimental conditions for synthesis of porous fuel particles using a granulating furnace and for preparation of UO2 pellets, and fabrication and performance demonstration of engineering scale equipment for off-gas treatment of semi-volatile nuclides, and development of phosphate ceramic technology for immobilization of used filters. Radioactivation characterization and treatment equipment design of metal wastes from pretreatment process was conducted, and preliminary experiments of chlorination/electrorefining techniques for the treatment of hull wastes were performed. Based on the verification of the key technologies for head-end process via the hot-cell tests using spent nuclear fuel, pre-conceptual design for the head-end equipments was performed.

Democrazia e scrittura della storia

NARCIS (Netherlands)

de Baets, Antoon

2015-01-01

In questo saggio cerchiamo di chiarire le relazioni fra la democrazia e la scrittura della storia. La nostra strategia consiste nell’esplorare innanzitutto la relazione generale fra la democrazia e la coscienza storica per poi esaminare quella fra la democrazia e la storiografia in quanto tale,

Study on thermal performance and margins of BWR fuel elements

International Nuclear Information System (INIS)

Stosic, Zoran

1999-01-01

This paper contributes to developing a methodology of predicting and analyzing thermal performance and margins of Boiling Water Reactor (BWR) fuel assemblies under conditions of reaching high quality Boiling Crisis and subsequent post-dryout thermal hydraulics causing temperature excursion of fuel cladding. Operational margins against dryout and potential for increasing fuel performance with appropriate benefits are discussed. The philosophy of modeling with its special topics are demonstrated on the HECHAN (HEated CHannel ANalyzer) model as the state-of-art for thermal-hydraulics analysis of BWR fuel assemblies in pre- and post-dryout two-phase flow regimes. The scope of further work either being or has to be performed concerning implementation of new physical aspects, including domain extension of HECHAN model applications to the Pressurized Water Reactors (PWRs), is discussed. Finally, a comprehensive overview of the literature dealing with development of the model is given. (author)

Studsvik`s fuel R and D projects

Energy Technology Data Exchange (ETDEWEB)

Grounes, M [Studsvik Nuclearr AB, Nykoping (Sweden)

1997-08-01

The report reviews some recently performed, ongoing and planned fuel R and D projects, executed by Studsvik Nuclear AB, a subsidiary of Studsvik AB. Data from these projects are used as experimental support for fuel modelling at high burnup. Much of Studsvik Nuclear`s R and D work has been concentrated on fuel testing, which can be made in the R2 test reactor with high precision under realistic water reactor conditions. This type of work started in the early 1960s. The fuel testing projects executed at Studsvik have been organized under three different types of sponsorship: International (multilateral) fuel projects: jointly sponsored internationally on a world-wide basis, with project information remaining restricted to the project participants throughout the project`s duration and for some pre-determined time after project completion; Bilateral fuel projects: sponsored by one single organization, or a few co-operating organizations, with project information remaining restricted to the sponsor, sometimes published later; in-house R and D work: sponsored by Studsvik Nuclear. The fuel testing activities can be divided into a number of well-defined steps as follows: Base irradiation, performed in a power reactor, or in Studsvik`s R2 test reactor; power ramping and/or other in-pile measurements, performed in Studsvik`s R2 test reactor. Non-destructive testing between different phases of an experiment, performed in Studsvik`s R2 reactor pool, or in Studsvik`s Hot Cell Laboratory; destructive post-irradiation examinations, performed in Studsvik`s Hot Cell Laboratory, or in the sponsor`s hot cell laboratory. 47 refs, 2 tabs.

Autoxidation of jet fuels: Implications for modeling and thermal stability

Energy Technology Data Exchange (ETDEWEB)

Heneghan, S.P. [Univ. of Dayton Research Institute, OH (United States); Chin, L.P. [Systems Research Laboratories, Inc., Dayton, OH (United States)

1995-05-01

The study and modeling of jet fuel thermal deposition is dependent on an understanding of and ability to model the oxidation chemistry. Global modeling of jet fuel oxidation is complicated by several facts. First, liquid jet fuels are hard to heat rapidly and fuels may begin to oxidize during the heat-up phase. Non-isothermal conditions can be accounted for but the evaluation of temperature versus time is difficult. Second, the jet fuels are a mixture of many compounds that may oxidize at different rates. Third, jet fuel oxidation may be autoaccelerating through the decomposition of the oxidation products. Attempts to model the deposition of jet fuels in two different flowing systems showed the inadequacy of a simple two-parameter global Arrhenius oxidation rate constant. Discarding previous assumptions about the form of the global rate constants results in a four parameter model (which accounts for autoacceleration). This paper discusses the source of the rate constant form and the meaning of each parameter. One of these parameters is associated with the pre-exponential of the autoxidation chain length. This value is expected to vary inversely to thermal stability. We calculate the parameters for two different fuels and discuss the implication to thermal and oxidative stability of the fuels. Finally, we discuss the effect of non-Arrhenius behavior on current modeling of deposition efforts.

Dimensional response of CANDU fuel to power changes

Energy Technology Data Exchange (ETDEWEB)

Fehrenbach, P J [Fuel Engineering Branch, Chalk River Nuclear Laboratories, Atomic Energy of Canada Limited, Chalk River, ON (Canada); Hastings, I J; Morel, P A; Sage, R D; Smith, A D [Fuel Materials Branch, Chalk River Nuclear Laboratories, Atomic Energy of Canada Limited, Chalk River, ON (Canada)

1983-06-01

The introduction of CANLUB-coated fuel cladding, modified fuel management schemes, and revisions to the sequence of control rod movements, have eliminated power ramping fuel failures in CANDU power reactors. However, an irradiation program continues at Chalk River Nuclear Laboratories to determine the effect of various design and operating parameters on the dimensional response of UO{sub 2} fuel elements to power changes, over a range of conditions outside those normally experienced by CANDU power reactor fuel. We have investigated the effect of power changes on element diameter for UO{sub 2} fuel with starting densities of 10.6 and 10.8 Mg/m{sup 3} clad in 0.4 mm thick Zircaloy, at burnups from 0 to 100 MW.h/kg U. Element diameter measurements were obtained at power using an In-Reactor Diameter Measuring Rig (IRDMR). Rates of power change over the range 0.0005 to 0.03 kW.m{sup -1}.s{sup -1} were achieved by a combination of reactor power control and use of a Helium-3 power cycling facility. Total diameter increases in unirradiated elements were about 1% at pellet interface locations for both fuel densities during the initial power increase to 60 kW/m. Diameter changes during subsequent power cycles of these elements from 55 to 100% maximum power were significantly larger for the higher density fuel, ranging from 0.3 to 0.5% compared to less than 0.1% for the standard density (10.6 Mg/m{sup 3}) fuel. In elements pre-irradiated at 27 kW/m to burnups of about 100 MW.h/kg U prior to power ramping, the diameter increases measured after ramping to 55 kW/m also varied with starting fuel density. Diameter changes at pellet interface locations were about 0.9% and 0.6% for higher density and standard density fuel respectively. (author)

Ignition delay and soot oxidative reactivity of MTBE blended diesel fuel

KAUST Repository

Yang, Seung Yeon; Naser, Nimal; Chung, Suk-Ho; Al-Qurashi, Khalid

2014-01-01

Methyl tert-butyl ether (MTBE) was added to diesel fuel to investigate the effect on ignition delay and soot oxidative reactivity. An ignition quality tester (IQT) was used to study the ignition propensity of MTBE blended diesel fuels in a reactive spray environment. The IQT data showed that ignition delay increases linearly as the MTBE fraction increases in the fuel. A four-stroke single cylinder diesel engine was used to generate soot samples for a soot oxidation study. Soot samples were pre-treated using a tube furnace in a nitrogen environment to remove any soluble organic fractions and moisture content. Non-isothermal oxidation of soot samples was conducted using a thermogravimetric analyzer (TGA). It was observed that oxidation of 'MTBE soot' started began at a lower temperature and had higher reaction rate than 'diesel soot' across a range of temperatures. Several kinetic analyses including an isoconversional method and a combined model fitting method were carried out to evaluate kinetic parameters. The results showed that Diesel and MTBE soot samples had similar activation energy but the pre-exponential factor of MTBE soot was much higher than that of the Diesel soot. This may explain why MTBE soot was more reactive than Diesel soot. It is suggested that adding MTBE to diesel fuel is better for DPF regeneration since an MTBE blend can significantly influence the ignition characteristics and, consequently, the oxidative reactivity of soot. Copyright © 2014 SAE International.

Ignition delay and soot oxidative reactivity of MTBE blended diesel fuel

KAUST Repository

Yang, Seung Yeon

2014-04-01

Methyl tert-butyl ether (MTBE) was added to diesel fuel to investigate the effect on ignition delay and soot oxidative reactivity. An ignition quality tester (IQT) was used to study the ignition propensity of MTBE blended diesel fuels in a reactive spray environment. The IQT data showed that ignition delay increases linearly as the MTBE fraction increases in the fuel. A four-stroke single cylinder diesel engine was used to generate soot samples for a soot oxidation study. Soot samples were pre-treated using a tube furnace in a nitrogen environment to remove any soluble organic fractions and moisture content. Non-isothermal oxidation of soot samples was conducted using a thermogravimetric analyzer (TGA). It was observed that oxidation of \\'MTBE soot\\' started began at a lower temperature and had higher reaction rate than \\'diesel soot\\' across a range of temperatures. Several kinetic analyses including an isoconversional method and a combined model fitting method were carried out to evaluate kinetic parameters. The results showed that Diesel and MTBE soot samples had similar activation energy but the pre-exponential factor of MTBE soot was much higher than that of the Diesel soot. This may explain why MTBE soot was more reactive than Diesel soot. It is suggested that adding MTBE to diesel fuel is better for DPF regeneration since an MTBE blend can significantly influence the ignition characteristics and, consequently, the oxidative reactivity of soot. Copyright © 2014 SAE International.

Microstructural characteristics of PWR [pressurized water reactor] spent fuel relative to its leaching behavior

International Nuclear Information System (INIS)

Wilson, C.N.

1986-01-01

Microstructural, compositional and thermochemical properties of spent nuclear fuel are discussed relative to its potential performance as a high-level waste form under proposed Nevada Nuclear Waste Storage Investigations Project tuff repository conditions. Pressurized water reactor spent fuel specimens with various artificially induced cladding defects were leach tested in deionized water and in a reference tuff groundwater under ambient hot cell air and temperature conditions. Greater fractional actinide release was observed with bare fuel than with clad fuel leached through a cladding defect. Congruent actinide release and preferential release of cesium and technetium were observed in both water types. Selected summary radionuclide release data are presented and correlated to pre- and post-test microstructural characterization data

Feeding strategies of Rattus norvegicus: a review / Una sintesi di alcuni aspetti della strategia alimentare del ratto Rattus norvegicus

Directory of Open Access Journals (Sweden)

Mara Cagnin

1987-07-01

the foraging behaviour of the rat, are: the constant sampling of al1 the potential foods that brings the populations to a noteworthy adaptability to the change of available resources; the social interactions among individuals (mother-pups, adult-adult that are very important in influencing the food preferences and, eventually, the food avoidance; the use of feeding-places, which is considered as a fundamental trait of the foraging behaviour of the rat, working as an information-centre of the animals. Riassunto Sono stati esaminati alcuni dei più importanti aspetti della strategia alimentare del ratto, Rattus norvegicus (Berkenhout, 1769 considerando in particolare il comportamento dei selvatici e i lavori in natura. Le marcate differenze individuali nelle preferenze alimentari ed il campionamento continuo di tutte le potenziali fonti alimentari, permettono alle popolazioni naturali di sfruttare un gran numero di risorse dell'ambiente, adattandosi alle sue variazioni. I1 comportamento di accumulo, ben evidenziato in laboratorio ma scarsamente documentato in natura, sembra nel ratto un meccanismo utilizzato solo per far fronte a situazioni particolari (es. surplus di cibo, allattamento. I1 grado di neofobia è variamente modulato in popolazioni che hanno un rapporto con l'ambiente umano e assente nelle popolazioni non commensali. Molto importanti risultano le interazioni sociali fra gli individui (madre-piccoli, adulti-adulti nell'influenzare le scelte alimentari. Vengono discussi i dati relativi alla predazione su Molluschi che confermano l'ipotesi di una trasmissione delle informazioni riguardo alla scoperta di nuovi alimenti e delle tecniche di apertura del guscio. La formazione di mense viene interpretata come un fondamentale aspetto del comportamento di foraggiamento del ratto, rilevante come centro per lo scambio di informazioni fra gli animali.

Romanian nuclear fuel program: past, present and future

International Nuclear Information System (INIS)

Budan, O.; Rotaru, I.; Galeriu, C.A.

1997-01-01

and authorized CANDU-6 fuel supplier. The re-loading of the Cernavoda NGS Unit 1 started in the middle of January 1997 with fuel produced by the Romanian fuel plant. The quality evaluation of the 'pre-1990' fuel started in April 1996 and was performed by the Nuclear Fuel Plant (FCN) Pitesti, under the supervision of the Nuclear Power Group (GEN) - a distinct department of RENEL. The future prospect and trend of the Romanian Nuclear Fuel Program are also presented in this paper

A battery-fuel cell hybrid auxiliary power unit for trucks: Analysis of direct and indirect hybrid configurations

International Nuclear Information System (INIS)

Samsun, Remzi Can; Krupp, Carsten; Baltzer, Sidney; Gnörich, Bruno; Peters, Ralf; Stolten, Detlef

2016-01-01

Highlights: • A battery-fuel cell hybrid auxiliary power unit for heavy duty vehicles is reported. • Comparison of direct and indirect hybrids using representative load profiles. • Evaluation based on validated fuel cell system and battery models. • Indirect hybrid with constant fuel cell load yields 29.3% hybrid system efficiency. • Fuel cell should be pre-heated using waste heat from the diesel engine during drive. - Abstract: The idling operation of engines in heavy duty vehicles to cover electricity demand during layovers entails significant fuel consumption and corresponding emissions. Indeed, this mode of operation is highly inefficient and a noteworthy contributor to the transportation sector’s aggregate carbon dioxide emissions. Here, a potential solution to this wasteful practice is outlined in the form of a hybrid battery-fuel cell system for application as an auxiliary power unit for trucks. Drawing on experimentally-validated fuel cell and battery models, several possible hybrid concepts are evaluated and direct and indirect hybrid configurations analyzed using a representative load profile. The results indicate that a direct hybrid configuration is only applicable if the load demand profile does not deviate strongly from the assumed profile. Operation of an indirect hybrid with a constant fuel cell load yields the greatest hybrid system efficiency, at 29.3%, while battery size could be reduced by 87% if the fuel cell is operated at the highest dynamics. Maximum efficiency in truck applications can be achieved by pre-heating the system prior to operation using exhaust heat from the motor, which increased system efficiency from 25.3% to 28.1%, including start-up. These findings confirm that hybrid systems could offer enormous fuel savings and constitute a sizeable step on the path toward energy-efficient and environmentally-friendly heavy duty vehicles that does not necessitate a fuel switch.

A Review of Hydrothermal Liquefaction Bio-Crude Properties and Prospects for Upgrading to Transportation Fuels

Directory of Open Access Journals (Sweden)

Jerome A. Ramirez

2015-07-01

Full Text Available Hydrothermal liquefaction (HTL presents a viable route for converting a vast range of materials into liquid fuel, without the need for pre-drying. Currently, HTL studies produce bio-crude with properties that fall short of diesel or biodiesel standards. Upgrading bio-crude improves the physical and chemical properties to produce a fuel corresponding to diesel or biodiesel. Properties such as viscosity, density, heating value, oxygen, nitrogen and sulphur content, and chemical composition can be modified towards meeting fuel standards using strategies such as solvent extraction, distillation, hydrodeoxygenation and catalytic cracking. This article presents a review of the upgrading technologies available, and how they might be used to make HTL bio-crude into a transportation fuel that meets current fuel property standards.

Operation experience of the advanced fuel assemblies at Unit 1 of Volgodonsk NPP within four fuel cycles

International Nuclear Information System (INIS)

Vasilchenko, I.; Kobelev, S.; Kushmanov, S.

2006-01-01

The first commissioning of Volgodonsk NPP Unit 1 with standard reactor WWER-1000 (project V-320) was in 2001. The reactor core, starting from the first fuel charge, was arranged completely with Advanced Fuel Assemblies (AFAs). In this way, it is possible to obtain the experience in startup and operation of the core, completely arranged with AFAs, and also to get a possibility of performing the comprehensive check for justification of newly commissioned units and justification of design solutions accepted in the design of reactor core for Taiwan NPP, Bushehr NPP and Kudankulam NPP. The first fuel charge of the Volgodonsk NPP Unit 1 is a reference and unified for Tiawan NPP (V-428), Bushehr NPP (V-446), Kudankulam NPP(V-412) with small differences caused by design features of RP V-320. The first core charge of Unit 1 of Volgodonsk NPP was arranged of 163 AFAs, comprising 61 CPS ARs and 42 BAR bundles. The subsequent fuel charges were arranged of AFAs with gadolinium oxide integrated into fuel instead of BAR. By 2005 the results of operation of the core at Unit 1 of Volgodonsk NPP during four fuel cycles showed that AFA is sufficiently reliable and serviceable. The activity of the primary coolant of the Volgodonsk NPP is at stable low level. During the whole time of the core operation of the Volgodonsk NPP Unit 1 no leaky AFAs were revealed. The modifications of the internals, made during pre-operational work, are reasonable and effective to provide for fuel mechanical stability in the course of operation. The modifications, made in AFA structure during operation of the Volgodonsk NPP Unit 1, are aimed at improving the service and operational reliability of its components. Correctness of the solutions taken is confirmed by AFAs operation experience both at the Volgodonsk NPP, and at other operating Russian NPPs

Heterogeneous Recycle of Transuranics Fuels in Fast Reactors

International Nuclear Information System (INIS)

Hoffman, Edward; Taiwo, Temitope; Hill, Robert

2008-01-01

A preliminary physics evaluation of the impacts of heterogeneous recycle using Pu+Np driver and minor actinide target fuel assemblies in fast reactor cores has been performed by comparing results to those obtained for a reference homogeneous recycle core using driver assemblies containing grouped transuranic (TRU) fuel. Parametric studies are performed on the reference heterogeneous recycle core to evaluate the impacts of variations in the pre- and post-separation cooling times, target material type (uranium and non-uranium based), target amount and location, and other parameters on the system performance. This study focused on startup, single-pass cores for the purpose of quantifying impacts and also included comparisons to the option of simply storing the LWR spent nuclear fuel over a 50-year period. An evaluation of homogeneous recycle cores with elevated minor actinide contents is presented to illustrate the impact of using progressively higher TRU content on the core and transmutation performance, as a means of starting with known fuel technology with the aim of ultimately employing grouped TRU fuel in such cores. Reactivity coefficients and safety parameters are presented to indicate that the cores evaluated appear workable from a safety perspective, though more detailed safety and systems evaluations are required. (authors)

Experimental investigation and modeling of an aircraft Otto engine operating with gasoline and heavier fuels

Science.gov (United States)

Saldivar Olague, Jose

A Continental "O-200" aircraft Otto-cycle engine has been modified to burn diesel fuel. Algebraic models of the different processes of the cycle were developed from basic principles applied to a real engine, and utilized in an algorithm for the simulation of engine performance. The simulation provides a means to investigate the performance of the modified version of the Continental engine for a wide range of operating parameters. The main goals of this study are to increase the range of a particular aircraft by reducing the specific fuel consumption of the engine, and to show that such an engine can burn heavier fuels (such as diesel, kerosene, and jet fuel) instead of gasoline. Such heavier fuels are much less flammable during handling operations making them safer than aviation gasoline and very attractive for use in flight operations from naval vessels. The cycle uses an electric spark to ignite the heavier fuel at low to moderate compression ratios, The stratified charge combustion process is utilized in a pre-chamber where the spray injection of the fuel occurs at a moderate pressure of 1200 psi (8.3 MPa). One advantage of fuel injection into the combustion chamber instead of into the intake port, is that the air-to-fuel ratio can be widely varied---in contrast to the narrower limits of the premixed combustion case used in gasoline engines---in order to obtain very lean combustion. Another benefit is that higher compression ratios can be attained in the modified cycle with heavier fuels. The combination of injection into the chamber for lean combustion, and higher compression ratios allow to limit the peak pressure in the cylinder, and to avoid engine damage. Such high-compression ratios are characteristic of Diesel engines and lead to increase in thermal efficiency without pre-ignition problems. In this experimental investigation, operations with diesel fuel have shown that considerable improvements in the fuel efficiency are possible. The results of

Behaviour of Spent WWER fuel under long term storage conditions

Energy Technology Data Exchange (ETDEWEB)

Kadarmetov, I M [A.A.Bochvar All-Russia Research Institute of Inorganic Materials, Moscow (Russian Federation)

1999-07-02

Results of experimental investigation into thermomechanical properties of pre-irradiated Zr-1%Nb alloy over a range temperatures 500-570 grad C are presented. Safety examination of the Ventilation Storage Casks dry storage system has been carried out. Preliminary safety criteria under dry storage conditions in an environment of inert gas are follows: maximum cladding temperature under normal conditions of dry storage should not exceed 330 grad C after 5-year cooling in water-filled pools; maximum allowable temperature of spent fuel rod cladding under operational mode with infringement of heat removal should not exceed 440 grad C over 8 hours. As each SFA dry storage project comprises its individual technology of spent fuel management, it is necessary to evaluate allowable parameters (terms of storage, maximum temperatures of fuel) for each project respectively. The programme of experimental investigations for the justification of safety criteria for WWER-1000 dry spent fuel storage systems is underway. (author)

SOLID OXIDE FUEL CELL HYBRID SYSTEM FOR DISTRIBUTED POWER GENERATION

Energy Technology Data Exchange (ETDEWEB)

Faress Rahman; Nguyen Minh

2003-07-01

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

Thermal dimensioning of spent fuel repository

International Nuclear Information System (INIS)

Ikonen, K.

2009-09-01

This report contains the temperature dimensioning of the KBS-3V type nuclear fuel repository in Olkiluoto for the BWR, VVER and EPR fuel canisters, which are disposed at vertical position in the horizontal tunnels in a rectangular geometry according to the preliminary Posiva plan. This report concerns only the temperature dimensioning of the repository and does not take into account the possible restrictions caused by the stresses induced in the rock. The maximum temperature on the canister-bentonite interface is limited to the design temperature of +100 deg C. However, due to uncertainties in thermal analysis parameters (like scattering in rock conductivity or in predicted decay power) the allowable calculated maximum canister temperature is set to 90 deg C causing a safety margin of 10 deg C. The allowable temperature is controlled by adjusting the space between adjacent canisters, adjacent tunnels and the pre-cooling time affecting on power of the canisters. The temperature of canister surfaces can be determined by superposing analytic line heat source models much more efficiently than by numerical analysis, if the analytic model is first calibrated by numerical analysis (by control volume method). This was done by comparing the surface temperatures of a single canister calculated numerically and analytically. For the Olkiluoto repository of one panel having 900 canisters of BWR, VVER and EPR spent fuel was analyzed. The analyses were performed with an initial canister power of 1 700 W, 1 370 W and 1 830 W, respectively. These decay heats are obtained when the pre-cooling times of the fuels are 32.9, 29.6 and 50.3 years (the burn-up values 40, 40 and 50 MWd/kgU, respectively). The analyses gave as a result the canister spacing (6.0-10.8 m), when the tunnel spacing was 25 m, 30 m or 40 m. On the edge areas of the panel with constant canister spacing the temperatures of the canisters are lower than in the middle area of the repository. Thus it is possible to pack

Plant Characteristics of an Integrated Solid Oxide Fuel Cell Cycle and a Steam Cycle

DEFF Research Database (Denmark)

Rokni, Masoud

2010-01-01

Plant characteristics of a system containing a solid oxide fuel cell (SOFC) cycle on the top of a Rankine cycle were investigated. Natural gas (NG) was used as the fuel for the plant. A desulfurization reactor removes the sulfur content in the fuel, while a pre-reformer broke down the heavier...... recovery steam generator (HRSG). The remaining energy of the off-gases was recycled back to the topping cycle for further utilization. Several parameter studies were carried out to investigate the sensitivity of the suggested plant. It was shown that the operation temperature of the desulfurization unit...

Fuel Exhaling Fuel Cell.

Science.gov (United States)

Manzoor Bhat, Zahid; Thimmappa, Ravikumar; Devendrachari, Mruthyunjayachari Chattanahalli; Kottaichamy, Alagar Raja; Shafi, Shahid Pottachola; Varhade, Swapnil; Gautam, Manu; Thotiyl, Musthafa Ottakam

2018-01-18

State-of-the-art proton exchange membrane fuel cells (PEMFCs) anodically inhale H 2 fuel and cathodically expel water molecules. We show an unprecedented fuel cell concept exhibiting cathodic fuel exhalation capability of anodically inhaled fuel, driven by the neutralization energy on decoupling the direct acid-base chemistry. The fuel exhaling fuel cell delivered a peak power density of 70 mW/cm 2 at a peak current density of 160 mA/cm 2 with a cathodic H 2 output of ∼80 mL in 1 h. We illustrate that the energy benefits from the same fuel stream can at least be doubled by directing it through proposed neutralization electrochemical cell prior to PEMFC in a tandem configuration.

Fuel management at the Petten high flux reactor

International Nuclear Information System (INIS)

Thijssen, P.J.M.

1999-01-01

Several years ago the shipment of spent fuel of the High Flux Reactor (HFR) at Petten has come to a standstill resulting in an ever growing stock of fuel elements that are labelled 'fully burnt up'. Examination of those elements showed that a reasonably number of them have a relatively high 235 U mass left. A reactor physics analysis showed that the use of such elements in the peripheral core zone allows the loading of four instead of five fresh fuel elements in many cycle cores. For the assessment of safety and performance parameters of HFR cores a new calculational tool is being developed. It is based on AEA Technology's Reactor physics code suite Winfrith Improved Multigroup Scheme (WIMS). NRG produced pre- and post-processing facilities to feed input data into WIMS's 2D transport code CACTUS and to extract relevant parameters from the output. The processing facilities can be used for many different types of application. (author)

Irradiation performance of PFBR MOX fuel after 112 GWd/t burn-up

Energy Technology Data Exchange (ETDEWEB)

Venkiteswaran, C.N., E-mail: cnv@igcar.gov.in; Jayaraj, V.V.; Ojha, B.K.; Anandaraj, V.; Padalakshmi, M.; Vinodkumar, S.; Karthik, V.; Vijaykumar, Ran; Vijayaraghavan, A.; Divakar, R.; Johny, T.; Joseph, Jojo; Thirunavakkarasu, S.; Saravanan, T.; Philip, John; Rao, B.P.C.; Kasiviswanathan, K.V.; Jayakumar, T.

2014-06-01

The 500 MWe Prototype Fast Breeder Reactor (PFBR) which is in advanced stage of construction at Kalpakkam, India, will use mixed oxide (MOX) fuel with a target burnup of 100 GWd/t. The fuel pellet is of annular design to enable operation at a peak linear power of 450 W/cm with the requirement of minimum duration of pre-conditioning. The performance of the MOX fuel and the D9 clad and wrapper material was assessed through Post Irradiation Examinations (PIE) after test irradiation of 37 fuel pin subassembly in Fast Breeder Test Reactor (FBTR) to a burn-up of 112 GWd/t. Fission product distribution, swelling and fuel–clad gap evolution, central hole diameter variation, restructuring, fission gas release and clad wastage due to fuel–clad chemical interaction were evaluated through non-destructive and destructive examinations. The examinations have indicated that the MOX fuel can safely attain the desired target burn-up in PFBR.

Development of hold down plate of INGLE fuel assembly

International Nuclear Information System (INIS)

Kim, Hyeong Koo; Kim, Kyu Tae

1996-07-01

Hold down plate for the INGLE fuel which has been designed for high performance in the standpoints of thermal margin and structural integrity compared to current fuel for YGN 3/4 and UCN 3/4 has been developed and its structural integrity has been verified based on the eh stress analysis. The design feature of the developed hold down plate has not only perfect compatibility with the reactor internals of Korea standard reactor, but also brand-new locking mechanism between upper tie plate and guide tubes. This locking mechanism introduced to the INGLE fuel provides very simple and reliable reconstitutability. In this report, finite element stress analysis with the aid of the ANSYS code as a solver and the MSC/PATRAN code as a pre and post processor were performed to verify structural integrity of the hold down plate considering various load cases which seem to be applied to the hold down plate during its lifetime. Based on the analysis results, the developed hold down plate for INGLE fuel sustains structural integrity under considered load conditions. 3 tabs., 16 figs., 9 refs. (Author)

Beginning-of-Life Data Report for the Instrumented Fuel Assembly (IFA)-527

Energy Technology Data Exchange (ETDEWEB)

Lanning, D. D.

1981-09-01

This report presents beginning-of-life (BOL) data from the first four months of operation of the six-rod instrumented fuel assembly (IFA)-527 in the Halden Boiling Water Reactor (HBWR), Halden, Norway. This assembly is the last in a series of U.S. Nuclear Regulatory Commission (NRC)-sponsored tests to verify steady-state fuel performance computer codes. IFA-527 contains five identical rods with high-density stable fuel pellets and 0.23-mm diametral gaps and one rod with similar fuel pellets but with a 0.06-mm diametral gap. All six rods were xenon-filled to provide simulation of the effects of fission gas and to enhance the observable effects of fuel cracking and relocation on fuel temperatures. The assembly operated successfully from July 1, 1980, to August 15, 1980; and then the reactor was shut down until September 10, 1980. Sometime during the shutdown, four of the six rods suffered pressure boundary failure. The decision was made to restart the reactor to collect operating data with failed rods. This report presents both pre- and postfailure data for IFA-527.

GAP pre-polymer, as an energetic binder and high performance additive for propellants and explosives: A review

Directory of Open Access Journals (Sweden)

Mehmet S. Eroglu

2017-08-01

Full Text Available In preparation of energetic composite formulations, functionally terminated pre-polymers have been used as binder. After physically mixing the pre-polymers with oxidizing components, metallic fuel, burning rate modifier and other minor ingredients, they are cured with a suitable curing agent to provide physical and chemical stability. These pre-polymers could be functionalized with carboxyl, epoxide or hydroxyl groups at varying average chain functionalities. For carboxyl-terminated pre-polymers, an epoxy functional curing agents could be used. If the pre-polymer possesses hydroxyl groups, isocyanate functional curing agents are the most suitable curing agents in terms of easy and efficient processing. Glycidyl azide polymer (GAP is one of the well-known low-molecular weight energetic liquid pre-polymer, which was developed to use as energetic binder, high performance additive and gas generator for high performance smokeless composite propellant and explosive formulations. Linear or branched GAP can be synthesized by nucleophilic substitution reaction of corresponding poly(epichlorohydrin (PECH with sodium azide through replacement of chloromethyl groups of PECH with pendant energetic azido-methyl groups on the polyether main chain. Positive heat of formation (+957 kJ/kg enables exothermic and rapid decomposition of GAP producing fuel rich gases. Its polyether main chain provides GAP with relatively low glass transition temperature (Tg= - 48 oC and presence of hydroxyl functional groups allows it to have easy processing in curing with isocyanate curing agents to form covalently crosslinked polyurethane structure. These outstanding properties of GAP enable it to be used as energetic polymeric binder and high performance additive in preparation of energetic materials and low vulnerable explosives.

The optimal fuel mix and redistribution of social surplus in the Korean power market

International Nuclear Information System (INIS)

Kim, Hyunsook; Kim, Sung-Soo

2010-01-01

This paper investigates the difference between the optimal fuel mix incorporating a pre-installed generation capacity constraint and the actual fuel mix in the Korean power market. Since the restructuring of the market, the fuel mix has been determined partly by investors and partly by the Basic Plan for Long-Term Electricity Supply and Demand (BPE). Both the system marginal price (SMP), and the capacity payment (CP), which has been based on the fixed cost of a specific gas turbine generator, were intended to provide an investment incentive in the market; however, they did not bring about an optimal fuel mix in Korea. Under the circumstances of a shortage of base load generators, these generators may garner excessive profits due to a high SMP level. However, the adjustment scheme of profit between KEPCO and Gencos left scant profit for generators. This paper suggests that a contract is needed to create the appropriate profit and tax levels for these base load generators. The redistribution of profit improves equality between consumers and generators, and the proper margin creates incentives for base load technology investment in Korea. - Research highlights: → This paper aims to determine the optimal fuel mix in Korea and shows the difference between the optimal and actual fuel mix; → We discovered that the optimal fuel mix ratio should be 63.5%:20.5%:16.0%for nuclear energy, coal, and LNG, respectively; → Because the pre-installed capacity is taken as given, the optimal fuel mix under the given installed capacity is an addition of a new nuclear unit to the current fuel mix; → The additional profit above the profit margin in the BPE should be collected and redistributed to consumers; → While we provide an incentive to build nuclear and coal units in Korea, we also suggest that a contract is needed to guarantee the profit level for generators based on a government regulation constraint, the BPE, to achieve a fair treatment.

Oxide fuel fabrication technology development of the FaCT project (5). Current status on 9Cr-ODS steel cladding development for high burn-up fast reactor fuel

International Nuclear Information System (INIS)

Ohtsuka, Satoshi; Kaito, Takeji; Yano, Yasuhide; Yamashita, Shinichiro; Ogawa, Ryuichiro; Uwaba, Tomoyuki; Koyama, Shinichi; Tanaka, Kenya

2011-01-01

This paper describes evaluation results of in-reactor integrity of 9Cr and 12Cr-ODS steel cladding tubes and the plan for reliability improvement in homogeneous tube production, both of which are key points for the commercialized use of ODS steels as long-life fuel cladding tubes. A fuel assembly in the BOR-60 irradiation test including 9Cr and 12Cr-ODS fuel pins has achieved the highest burn-up, i.e. peak burn-up of 11.9at% and peak neutron dose of 51dpa, without any fuel pin rupture and microstructure instability. In another fuel assembly containing 9Cr and 12Cr-ODS steel fuel pins whose peak burn-up was 10.5at%, one 9Cr-ODS steel fuel pin failed near the upper end of the fuel column. A peculiar microstructure change occurred in the vicinity of the ruptured area. The primary cause of this fuel pin rupture and microstructure change was shown to be the presence of metallic Cr inclusions in the 9Cr-ODS steel tube, which had passed an ultrasonic inspection test for defects. In the next stage from 2011 to 2013, the fabrication technology of full pre-alloy 9Cr-ODS steel cladding tube will be developed, where the handling of elemental powder is prohibited in the process. (author)

Experimental assessment of pre-turbo aftertreatment configurations in a single stage turbocharged diesel engine. Part 1: Steady-state operation

OpenAIRE

Luján, José M.; Bermúdez, Vicente; Piqueras, P.; Garcia Afonso, Oscar

2015-01-01

Diesel oxidation catalysts and diesel particulate filters are standard aftertreatment systems in Diesel engines which are traditionally placed downstream of the turbine. However, pre-turbo aftertreatment configurations are being approached as a way to improve the aftertreatment performance in terms of light-off and passive regeneration. This exhaust line architecture can also benefit fuel economy. The objective of this work is to analyse experimentally how the pre-turbo aftertreatment placeme...

Enhancing the ABAQUS Thermomechanics Code to Simulate Steady and Transient Fuel Rod Behavior

International Nuclear Information System (INIS)

Williamson, R.L.; Knoll, D.A.

2009-01-01

A powerful multidimensional fuels performance capability, applicable to both steady and transient fuel behavior, is developed based on enhancements to the commercially available ABAQUS general-purpose thermomechanics code. Enhanced capabilities are described, including: UO2 temperature and burnup dependent thermal properties, solid and gaseous fission product swelling, fuel densification, fission gas release, cladding thermal and irradiation creep, cladding irradiation growth, gap heat transfer, and gap/plenum gas behavior during irradiation. The various modeling capabilities are demonstrated using a 2D axisymmetric analysis of the upper section of a simplified multi-pellet fuel rod, during both steady and transient operation. Computational results demonstrate the importance of a multidimensional fully-coupled thermomechanics treatment. Interestingly, many of the inherent deficiencies in existing fuel performance codes (e.g., 1D thermomechanics, loose thermo-mechanical coupling, separate steady and transient analysis, cumbersome pre- and post-processing) are, in fact, ABAQUS strengths.

Manufacturing technologies for direct methanol fuel cells (DMFCs)

Energy Technology Data Exchange (ETDEWEB)

Gluesen, Andreas; Mueller, Martin; Kimiaie, Nicola; Konradi, Irene; Mergel, Juergen; Stolten, Detlef [Forschungszentrum Juelich (Germany). Inst. of Energy Research - IEF-3: Fuel Cells

2010-07-01

Fuel cell research is focussing on increasing power density and lifetime and reducing costs of the whole fuel cell system. In order to reach these aims, it is necessary to develop appropriately designed components outgoing from high quality materials, a suitable manufacturing process and a well balanced system. To make use of the advantages that can be obtained by developing production technology, we are mainly improving the coating and assembling techniques for polymer electrolyte fuel cells, especially Direct Methanol Fuel Cells (DMFCs). Coating is used for making fuel cell electrodes as well as highly conductive contacts. Assembling is used to join larger components like membrane electrode assemblies (MEAs) and bipolar units consisting of flow fields and the separator plate, as well as entire stacks. On the one hand a reproducible manufacturing process is required to study fine differences in fuel cell performance affected by new materials or new designs. On the other hand a change in each parameter of the manufacturing process itself can change product properties and therefore affect fuel cell performance. As a result, gas diffusion electrodes (GDEs) are now produced automatically in square-meter batches, the hot-pressing of MEAs is a fully automated process and by pre-assembling the number of parts that have to be assembled in a stack was reduced by a factor of 10. These achievements make DMFC manufacturing more reproducible and less error-prone. All these and further developments of manufacturing technology are necessary to make DMFCs ready for the market. (orig.)

Elasticidade-preço da demanda por etanol no Brasil: como renda e preços relativos explicam diferenças entre estados

Directory of Open Access Journals (Sweden)

Veronica Fernandez Orellano

2013-12-01

Full Text Available Este artigo estuda a demanda por etanol no Brasil no período 2001-2009, considerando as características regionais de renda e de preços relativos. Essas características explicam variação relevante na elasticidade-preço da demanda, aspecto até então desconsiderado em estudos anteriores. Foi estimado um modelo econométrico a partir de um painel de dados estaduais mensais, no qual variáveis instrumentais foram usadas para controlar a endogeneidade na análise da demanda. Conclui-se que a demanda é mais elástica em estados mais pobres e em que o preço relativo está próximo a 70%, a taxa técnica de substituição entre etanol e gasolina, parâmetro relevante para as decisões de consumo de proprietários de veículos flex-fuel. Essas regiões apresentam maiores elasticidades-preço da demanda, em última análise, por conta de diferenças logísticas e tributárias, as quais definem o preço relativo. Esses resultados diferem daqueles obtidos por Salvo e Huse (2013, pois identificam diferenças regionais que independem da heterogeneidade das preferências dos consumidores, mas decorrem da configuração logística e de renda. Os resultados sugerem implicações para as políticas tributária e de infraestrutura logística, as quais, ao afetarem o nível de preços relativos de etanol e gasolina, afetam a sensibilidade da demanda com relação às variações de preço.

Design, fabrication and operating experience of Monju ex-vessel fuel storage tank

International Nuclear Information System (INIS)

Yokota, Yoshio; Yamagishi, Yoshiaki; Kuroha, Mitsuo; Inoue, Tatsuya

1995-01-01

In FBRs there are two methods of storing and cooling the spent fuel - the in-vessel storage and the ex-vessel storage. Because of the sodium leaks through the tank at the beginning of pre-operation, the utilization of the ex-vessel fuel storage tank (EVST) of some FBR plant has been changed from the ex-vessel fuel storage to the interim fuel transfer tank. This led to reactor designers focusing on the material, structure and fabrication of the carbon steel sodium storage tanks worldwide. The Monju EVST was at the final stage of the design, when the leaks occurred. The lesson learned from that experience and the domestic fabrication technology are reflected to the design and fabrication of the Monju EVST. This paper describes the design, fabrication and R and D results for the tank, and operating experience in functional test. The items to be examined are as follows: (1) Overall structure of the tank and design philosophy on the function, (2) Structure of the cover shielding plug and its design philosophy, (3) Structures of the rotating rack and its bearings, and their design philosophy, (4) Cooling method and its design philosophy, (5) Structure and fabrication of the cooling coil support inside EVST with comparison of leaked case, (6) R and D effort for items above. The fabrication of the Monju EVST started in August 1986 and it was shipped to the site in March 1990. Installation was completed in November 1990, and sodium fill after pre-heating started in 1991. The operation has been continued since September 1992. In 1996 when the first spent fuel is stored, its total functions will be examined. (author)

Estimation of wildfire size and risk changes due to fuels treatments

Science.gov (United States)

M. A. Cochrane; C. J. Moran; M. C. Wimberly; A. D. Baer; M. A. Finney; K. L. Beckendorf; J. Eidenshink; Z. Zhu

2012-01-01

Human land use practices, altered climates, and shifting forest and fire management policies have increased the frequency of large wildfires several-fold. Mitigation of potential fire behaviour and fire severity have increasingly been attempted through pre-fire alteration of wildland fuels using mechanical treatments and prescribed fires. Despite annual treatment of...

Final Report - Durable Catalysts for Fuel Cell Protection during Transient Conditions

Energy Technology Data Exchange (ETDEWEB)

Atanasoski, Radoslav [3M Company, St. Paul, MN (United States); van der Vliet, Dennis [3M Company, St. Paul, MN (United States); Cullen, David [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Atanasoska, Ljiljana [3M Company, St. Paul, MN (United States)

2015-01-26

The objective of this project was to develop catalysts that will enable proton exchange membranes (PEM) fuel cell systems to weather the damaging conditions in the fuel cell at voltages beyond the thermodynamic stability of water during the transient periods of start-up/shut-down and fuel starvation. Such catalysts are required to make it possible for the fuel cell to satisfy the 2015 DOE targets for performance and durability. The project addressed a key issue of importance for successful transition of PEM fuel cell technology from development to pre-commercial phase. This issue is the failure of the catalyst and the other thermodynamically unstable membrane electrode assembly (MEA) components during start-up/shut-down and local fuel starvation at the anode, commonly referred to as transient conditions. During these periods the electrodes can reach potentials higher than the usual 1.23V upper limit during normal operation. The most logical way to minimize the damage from such transient events is to minimize the potential seen by the electrodes. At lower positive potentials, increased stability of the catalysts themselves and reduced degradation of the other MEA components is expected.

Study on the behavior of irradiated light water reactor fuel during out-of-pile annealing

International Nuclear Information System (INIS)

Yanagisawa, Kazuaki; Kanazawa, Hiroyuki; Uno, Hisao; Sasajima, Hideo

1988-11-01

Using the pre-irradiated light water reactor fuel (burnup: 35 MWd/kgU) and the slightly irradiated NSRR fuel (burnup: 5.6 x 10 -6 MWd/kgU), FP gas release rate up to the temperature of 2273 K was measured through out-of-pile annealing test. Results of this experiment were compared with those of ORNL annealing test (SFD/HI-test series) performed in USA. Obtained conclusions are: (1) Maximum release rate of Kr gas in light water reactor fuel was 6.4 % min -1 at temperature of 2273 K. This was in good agreement with ORNL data. FP gas release rate during annealing test was increased greatly with increasing fuel burnup and annealing temperature. (2) No FP was detected in NSRR slightly irradiated fuel up to the temperature of 1913 K. (author)

Effect of mastication and other mechanical treatments on fuel structure in chaparral

Science.gov (United States)

Brennan, Teresa J.; Keeley, Jon E.

2015-01-01

Mechanical fuel treatments are a common pre-fire strategy for reducing wildfire hazard that alters fuel structure by converting live canopy fuels to a compacted layer of dead surface fuels. Current knowledge concerning their effectiveness, however, comes primarily from forest-dominated ecosystems. Our objectives were to quantify and compare changes in shrub-dominated chaparral following crushing, mastication, re-mastication and mastication-plus-burning treatments, and to assess treatment longevity. Results from analysis of variance (ANOVA) identified significant differences in all fuel components by treatment type, vegetation type and time since treatment. Live woody fuel components of height, cover and mass were positively correlated with time since treatment, whereas downed woody fuel components were negatively correlated. Herbaceous fuels, conversely, were not correlated, and exhibited a 5-fold increase in cover across treatment types in comparison to controls. Average live woody fuel recovery was 50% across all treatment and vegetation types. Differences in recovery between time-since-treatment years 1–8 ranged from 32–65% and exhibited significant positive correlations with time since treatment. These results suggest that treatment effectiveness is short term due to the rapid regrowth of shrubs in these systems and is compromised by the substantial increase in herbaceous fuels. Consequences of not having a full understanding of these treatments are serious and leave concern for their widespread use on chaparral-dominated landscapes.

Degradation of solid oxide fuel cells with wood

International Nuclear Information System (INIS)

N Frank; M Saule; J Karl

2006-01-01

The Technical University of Munich investigates the degradation effects observed on SOFCs when fired with product gases from biomass gasification processes. The TUM has concentrated its research on tubular SOFCs. For this purpose tubular electrolyte-supported SOFCs have been manufactured using commercially available electrolyte tubes, anode foil and cathode paste. The tubular SOFCs were first run with hydrogen and synthetic fuels. Once stable and reproducible results were achieved, tests with product gas from four different biomass gasifiers have started. These gasifiers have been coupled to a gas cleaning device which includes sulphur and particle removal and pre-reforming. Different operation conditions of the gasifiers and the gas cleaning device have been realized and the corresponding fuel cell degradations have been analysed. (authors)

Conversion of sewage sludge to clean solid fuel using hydrothermal carbonization: Hydrochar fuel characteristics and combustion behavior

International Nuclear Information System (INIS)

He, Chao; Giannis, Apostolos; Wang, Jing-Yuan

2013-01-01

Highlights: • The hydrothermal carbonization of sewage sludge process is developed. • Hydrochars are solid fuels with less nitrogen and sulfur contents. • The first order combustion reaction of hydrochars is derived. • Main combustion decomposition of hydrochars is easier and more stable. • Formation pathways of hydrochars during hydrothermal carbonization are proposed. - Abstract: Conventional thermochemical treatment of sewage sludge (SS) is energy-intensive due to its high moisture content. To overcome this drawback, the hydrothermal carbonization (HTC) process was used to convert SS into clean solid fuel without prior drying. Different carbonization times were applied in order to produce hydrochars possessing better fuel properties. After the carbonization process, fuel characteristics and combustion behaviors of hydrochars were evaluated. Elemental analysis showed that 88% of carbon was recovered while 60% of nitrogen and sulfur was removed. Due to dehydration and decarboxylation reactions, hydrogen/carbon and oxygen/carbon atomic ratios reduced to 1.53 and 0.39, respectively. It was found that the fuel ratio increased to 0.18 by prolonging the carbonization process. Besides, longer carbonization time seemed to decrease oxygen containing functional groups while carbon aromaticity structure increased, thereby rendering hydrochars highly hydrophobic. The thermogravimetric analysis showed that the combustion decomposition was altered from a single stage for raw sludge to two stages for hydrochars. The combustion reaction was best fitted to the first order for both raw sludge and hydrochars. The combustion of hydrochars is expected to be easier and more stable than raw sludge because of lower activation energy and pre-exponential factor

Current status of the transient integral fuel element performance code URANUS

International Nuclear Information System (INIS)

Preusser, T.; Lassmann, K.

1983-01-01

To investigate the behavior of fuel pins during normal and off-normal operation, the integral fuel rod code URANUS has been extended to include a transient version. The paper describes the current status of the program system including a presentation of newly developed models for hypothetical accident investigation. The main objective of current development work is to improve the modelling of fuel and clad material behavior during fast transients. URANUS allows detailed analysis of experiments until the onset of strong material transport phenomena. Transient fission gas analysis is carried out due to the coupling with a special version of the LANGZEIT-KURZZEIT-code (KfK). Fuel restructuring and grain growth kinetics models have been improved recently to better characterize pre-experimental steady-state operation; transient models are under development. Extensive verification of the new version has been carried out by comparison with analytical solutions, experimental evidence, and code-to-code evaluation studies. URANUS, with all these improvements, has been successfully applied to difficult fast breeder fuel rod analysis including TOP, LOF, TUCOP, local coolant blockage and specific carbide fuel experiments. Objective of further studies is the description of transient PCMI. It is expected that the results of these developments will contribute significantly to the understanding of fuel element structural behavior during severe transients. (orig.)

Development of a data-mining methodology for spent nuclear fuel forensics

International Nuclear Information System (INIS)

Sanghwa Lee; Kyungho Jin; Gyunyoung Heo; Jaekwang Kim

2017-01-01

The purpose of this study is to categorize the type of spent nuclear fuels using simulation data-based classification methods. Considering the practical conditions making the full analysis of radioactive nuclides difficult, the classification methods were designed to be robust to noise and missing information. The strength and weakness of three classifiers, linear discriminant analysis, quadratic discriminant analysis and support vector classification were compared, which is developed by the history information such as burnup, enrichment, and cooling type generated from ORIGEN-ARP upon fuel assembly types. Auto-Associative Kernel Regression improved outlier management as a pre-processing technique. (author)

Advances in nuclear fuel cycle materials and concepts. Vol. 1

Energy Technology Data Exchange (ETDEWEB)

El-Sayed, A A [Materials Division, Nuclear Research Centre, Atomic Energy Authority, Cairo (Egypt)

1996-03-01

This presentation gives an overview of the new trends in the materials used in various steps of the nuclear fuel cycle. This will cover fuels for various types of reactors (PWRs, HTRs, ... etc.) cladding materials, control rod materials, reactor structural materials, as well as materials used in the back end of the fuel cycle. Problems associated with corrosion of fuel cladding materials as well as those in control rod materials (B{sub 4} C swelling...etc.), and approaches for combating these influences are reviewed. For the case of reactor pressure vessel materials issues related to the influences of alloy composition, design approaches including the use of more forged parts and minimizing, as for as possible, longitudinal welds especially in the central region, are discussed. Furthermore the application of techniques for recovery of pre-irradiation mechanical properties of PVS components is also covered. New candidate materials for the construction of high level waste containers including modified types of stainless steel (high Ni and high MO), nickel-base alloys and titanium alloys are also detailed. Finally, nuclear fuel cycle concepts involving plutonium and actinides recycling shall be reviewed. 28 figs., 6 tabs.

Advances in nuclear fuel cycle materials and concepts. Vol. 1

International Nuclear Information System (INIS)

El-Sayed, A.A.

1996-01-01

This presentation gives an overview of the new trends in the materials used in various steps of the nuclear fuel cycle. This will cover fuels for various types of reactors (PWRs, HTRs, ... etc.) cladding materials, control rod materials, reactor structural materials, as well as materials used in the back end of the fuel cycle. Problems associated with corrosion of fuel cladding materials as well as those in control rod materials (B 4 C swelling...etc.), and approaches for combating these influences are reviewed. For the case of reactor pressure vessel materials issues related to the influences of alloy composition, design approaches including the use of more forged parts and minimizing, as for as possible, longitudinal welds especially in the central region, are discussed. Furthermore the application of techniques for recovery of pre-irradiation mechanical properties of PVS components is also covered. New candidate materials for the construction of high level waste containers including modified types of stainless steel (high Ni and high MO), nickel-base alloys and titanium alloys are also detailed. Finally, nuclear fuel cycle concepts involving plutonium and actinides recycling shall be reviewed. 28 figs., 6 tabs

Improvement of failed fuel detection system of light water reactor

International Nuclear Information System (INIS)

Chung, M.K.; Kang, H.D.; Cho, S.W.; Lee, K.W.

1981-01-01

Multi-task DAAS system by utilizing PDP-11/23 computer was assembled and tested for its performances. By connecting four Ge(Li) detectors to this DAAS, test experiments were done to prove system capability for detection and analysis of any fission gases resolved in four independently sampled primary cooling water from a power reactor. Appropriate computer programs were also introduced for this application and satisfactory results were obtained. Further application of this DAAS to the quality test of fuel pins (uniform distribution of enriched uranium in fresh fuel pellets), a prototype fuel scanner system was designed, constructed and tested. Operational principle of this system is based on the determination of 235 U/ 238 U abundance ratio in pellets by precision spectrometry or gamma-rays which are emitted from a portion of fuel pellets. For the uniform scanning, rotational and traverse motions at pre-selected speeds were applied to a fuel pin under tests. A long lens magnetic beta-spectrometer of Argonne National Laboratory was transferred to KAERI and re-installed for future precision beta-gamma spectroscopic research works on short-lived fission products nuclei

Development of a financing model for nuclear fuel cycle cost evaluation

International Nuclear Information System (INIS)

Takahashi, Makoto; Yajima, Masayuki

1984-01-01

It is necessary to evaluate the prices of nuclear fuel pre- and post-processing in order to analyse the costs of the nuclear power generation. Those prices are directly related to the costs of construction and operation of facilities in the nuclear fuel cycle. In this report, we propose a model which evaluates financing of an undertaking that constructs and operates one of the facilities such as uranium enrichment, reprocessing or interim storage of spent fuels. The model is divided into two phases, the construction phase and the operation phase. In the construction phase, it calculates expenses during the facility construction and corresponding financings for each term. In the operation phase, the model refers to the results of the construction phase and performs calculations on profits and losses, cash-flow, and disposition to profits term by according to a certain operation schedule. Using this model, feasibility of the undertaking and effects of various pricing strategies on the nuclear fuel costs can be evaluated by simulations. (author)

Status of plutonium recycle from mixed oxide fuel fabrication wastes (U,Pu)O2 facility activities

International Nuclear Information System (INIS)

Quesada, Calixto A.; Adelfang, Pablo; Greiner, G.; Orlando, Oscar S.; Mathot, Sergio R.

1999-01-01

Within the specific subject of mixed oxides corresponding to the Fuel Cycle activities performed at CNEA, the recovery of plutonium from wastes originated during tests and pre-fabrication stages is performed. (author)

Fuel cell generator with fuel electrodes that control on-cell fuel reformation

Science.gov (United States)

Ruka, Roswell J [Pittsburgh, PA; Basel, Richard A [Pittsburgh, PA; Zhang, Gong [Murrysville, PA

2011-10-25

A fuel cell for a fuel cell generator including a housing including a gas flow path for receiving a fuel from a fuel source and directing the fuel across the fuel cell. The fuel cell includes an elongate member including opposing first and second ends and defining an interior cathode portion and an exterior anode portion. The interior cathode portion includes an electrode in contact with an oxidant flow path. The exterior anode portion includes an electrode in contact with the fuel in the gas flow path. The anode portion includes a catalyst material for effecting fuel reformation along the fuel cell between the opposing ends. A fuel reformation control layer is applied over the catalyst material for reducing a rate of fuel reformation on the fuel cell. The control layer effects a variable reformation rate along the length of the fuel cell.

Performance, combustion timing and emissions from a light duty vehicle at different altitudes fueled with animal fat biodiesel, GTL and diesel fuels

International Nuclear Information System (INIS)

Ramos, Ángel; García-Contreras, Reyes; Armas, Octavio

2016-01-01

Highlights: • Effects of altitude, alternative fuels and driving conditions on emissions have been studied. • Combustion timing was studied by means of on-line thermodynamic diagnosis. • Altitude particularly increases the combustion duration of paraffinic fuels. • Altitude increases NOx emissions more than ten times compared to the sea level. • Effect of fuels on particulate matter is masked when diesel particle filters work efficiently. - Abstract: The altitude effect on performance, emissions and thermodynamic diagnosis under real world driving conditions has been evaluated using two alternative fuels and a diesel fuel. Three places, at different altitudes, were selected for the tests, from 0 to 2500 m above the sea level. Besides, two type of circuits (Urban and Extra-urban) have been selected in order to evaluate these two driving pattern conditions. A light duty diesel vehicle equipped with the same after-treatment system as Euro 5 engines was used as test vehicle. Thermodynamic diagnosis shows that, when the engine works with two pre-injection events (mainly at high altitude and without EGR) the ignition delay agrees of the cetane number of fuels. At urban conditions, altitude increases the combustion duration of all fuels and particularly with paraffinic fuels. The effect of altitude on THC and CO emissions is not noticeable, but at high altitude, NOx emissions during extra-urban tests were around three times higher than those from testing along the urban circuit. Besides, compared to circuits next to the sea level, these emissions at both circuits (urban and extra-urban) were around ten times higher, respectively, than the limits established by the Euro standards. The effect of fuels on pollutant emissions was masked by the variability associated to real driving conditions.

Pre-conceptual design of a spent PWR fuel disposal container

International Nuclear Information System (INIS)

Choi, Jong Won; Cho, Dong Keun; Lee, Yang; Choi, Heui Joo; Lee, Jong Youl

2005-01-01

In this paper, sets of engineering analyses were conducted to renew the overall dimensions and configurations of a disposal container proposed as a prototype in the previous study. Such efforts and calculation results can provide new design variables such as the inner basket array type and thickness of the outer shell and the lid and bottom of a spent nuclear fuel disposal container. These efforts include radiation shielding and nuclear criticality analyses to check to see whether the dimensions of the container proposed from the mechanical structural analyses can provide a nuclear safety or not. According to the results of the structural analysis of a PWR disposal container by varying the diameter of the container insert. the Maximum Von Mises stress from the 102 cm container meets the safety factor of 2.0 for both extreme and normal load conditions. This container also satisfies the nuclear criticality and radiation safety limits. This decrease in the diameter results in a weight loss of a container by ∼20 tons

Ignition and burn in inertially confined magnetized fuel

International Nuclear Information System (INIS)

Kirkpatrick, R.C.; Lindemuth, I.R.

1991-01-01

At the third International Conference on Emerging Nuclear Energy Systems, we presented computational results which suggested that ''breakeven'' experiments in inertial confinement fusion (ICF) may be possible with existing driver technology. We recently used the ICF simulation code LASNEX to calculate the performance of an idealized magnetized fuel target. The parameter space in which magnetized fuel operates is remote from that of both ''conventional'' ICF and magnetic confinement fusion devices. In particular, the plasma has a very high β and is wall confined, not magnetically confined. The role of the field is to reduce the electron thermal conductivity and to partially trap the DT alphas. The plasma is contained in a pusher which is imploded to compress and adiabatically heat the plasma from an initial condition of preheat and pre-magnetization to the conditions necessary for fusion ignition. The initial density must be quite low by ICF standards in order to insure that the electron thermal conductivity is suppressed and to minimize the generation of radiation from the plasma. Because the energy loss terms are effectively suppressed, the implosion may proceed at a relatively slow rate of about 1 to 3 cm/μs. Also, the need for low density fuel dictates a much larger target, so that magnetized fuel can use drivers with much lower power and power density. Therefore, magnetized fuel allows the use of efficient drivers that are not suitable for laser or particle beam fusion due to insufficient focus or too long pulse length. The ignition and burn of magnetized fuel involves very different dominant physical processes than does ''conventional'' ICF. The fusion time scale becomes comparable to the hydrodynamic time scale, but other processes that limit the burn in unmagnetized fuel are of no consequence. The idealized low gain magnetized fuel target presented here is large and requires a very low implosion velocity. 11 refs

Fuel and nuclear fuel cycle

International Nuclear Information System (INIS)

Prunier, C.

1998-01-01

The nuclear fuel is studied in detail, the best choice and why in relation with the type of reactor, the properties of the fuel cans, the choice of fuel materials. An important part is granted to the fuel assembly of PWR type reactor and the performances of nuclear fuels are tackled. The different subjects for research and development are discussed and this article ends with the particular situation of mixed oxide fuels ( materials, behavior, efficiency). (N.C.)

Test Results of PBMR Fuel Spheres

International Nuclear Information System (INIS)

Koshcheev, Konstantin; Diakov, Alexander; Beltyukov, Igor; Barybin, Andrey; Chernetsov, Mikhail

2014-01-01

Results of pre-irradiation testing of fuel spheres (FS) and coated particles (CP) manufactured by PBMR SOC (Republic of South Africa) are described. The stable high quality level of major characteristics (dimensions, CP coating structure, uranium-235 contamination of the FS matrix graphite and the outer PyC layer of the CP coating) are shown. Results of a methodical irradiation test of two FS in helium and neon medium at temperatures of 800 to 1300 °C with simultaneous determination of release-to-birth ratios for major gaseous fission products (GFP) are described. (author)

Using pre-heated sunflower oil as fuel in a diesel cycle engine

Energy Technology Data Exchange (ETDEWEB)

Delalibera, H.C.; Neto, P.H.W.; Martini, J. [State Univ. of Ponta Grossa (Brazil)

2010-07-01

This paper reported on a study in which 100 per cent sunflower oil was used in a tractor to compare its performance with petroleum diesel. Work trials were carried out for 50 hours on a single cylinder direct injection micro-tractor. In the first trial (E-1), the temperature of the vegetable oil was the same as the air temperature of the engine, while in the second trial (E-2), the oil was heated to a temperature of about 90 degrees C. Only petrodiesel was used in the third (E-3) trial. The head gasket burned in the first test after 50 hours of operation. An increase in compression was noted during trials E-1 and E-2. The carbonized mass in the nozzle of the E-2 trial was 81.5 per cent lower than in the E-1 trial. The carbonized mass in the intake system of the E-2 trial was 51.7 per cent lower than in the E-1 trial. The exhaust system of the E-2 trial was 33.4 per cent lower than that of the E-1 trial. For the combustion chamber, the carbonization of the E-1 trial was nearly the same as in the E-2 trial. The hourly fuel consumption of the E-1 trial was 2.3 per cent higher than petrodiesel, while E-2 trial was 0.7 per cent higher than petrodiesel. In the first 2 tests, the lubricating oil was contaminated by vegetable oil fuel. In general, results from the first trial were better than results from the second trial.

Large-Scale Production of Fuel and Feed from Marine Microalgae

Energy Technology Data Exchange (ETDEWEB)

Huntley, Mark [Cornell Univ., Ithaca, NY (United States)

2015-09-30

In summary, this Consortium has demonstrated a fully integrated process for the production of biofuels and high-value nutritional bioproducts at pre-commercial scale. We have achieved unprecedented yields of algal oil, and converted the oil to viable fuels. We have demonstrated the potential value of the residual product as a viable feed ingredient for many important animals in the global food supply.

Direct Coal -to-Liquids (CTL) for Jet Fuel Using Biomass-Derived Solvents

Energy Technology Data Exchange (ETDEWEB)

Chauhan, Satya P. [Battelle Memorial Inst., Columbus, OH (United States); Garbark, Daniel B. [Battelle Memorial Inst., Columbus, OH (United States); Taha, Rachid [Battelle Memorial Inst., Columbus, OH (United States); Peterson, Rick [Battelle Memorial Inst., Columbus, OH (United States)

2017-09-30

Battelle has demonstrated a novel and potentially breakthrough technology for a direct coal-to-liquids (CTL) process for producing jet fuel using biomass-derived coal solvents (bio-solvents). The Battelle process offers a significant reduction in capital and operating costs and a substantial reduction in greenhouse gas (GHG) emissions, without requiring carbon capture and storage (CCS). The results of the project are the advancement of three steps of the hybrid coal/biomass-to-jet fuel process to the technology readiness level (TRL) of 5. The project objectives were achieved over two phases. In Phase 1, all three major process steps were explored and refined at bench-scale, including: (1) biomass conversion to high hydrogen-donor bio-solvent; (2) coal dissolution in biomass-derived bio-solvent, without requiring molecular H₂, to produce a synthetic crude (syncrude); and (3) two-stage catalytic hydrotreating/hydrogenation of syncrude to jet fuel and other distillates. In Phase 2, all three subsystems of the CTL process were scaled up to a pre-pilot scale, and an economic analysis was carried out. A total of over 40 bio-solvents were identified and prepared. The most unique attribute of Battelle’s bio-solvents is their ability to provide much-needed hydrogen to liquefy coal and thus increase its hydrogen content so much that the resulting syncrude is liquid at room temperature. Based on the laboratory-scale testing with bituminous coals from Ohio and West Virginia, a total of 12 novel bio-solvent met the goal of greater than 80% coal solubility, with 8 bio-solvents being as good as or better than a well-known but expensive hydrogen-donor solvent, tetralin. The Battelle CTL process was then scaled up to 1 ton/day (1TPD) at a pre-pilot facility operated in Morgantown, WV. These tests were conducted, in part, to produce enough material for syncrude-upgrading testing. To convert the Battelle-CTL syncrude into a form suitable as a blending stock for jet

Deep desulfurization of jet fuel for applications in mobile fuel cell systems; Tiefentschwefelung von Flugturbinenkraftstoffen fuer die Anwendung in mobilen Brennstoffzellensystemen

Energy Technology Data Exchange (ETDEWEB)

Wang, Yong

2012-07-01

Fuel cell powered APUs are promising for the on-board electricity supply in heavy vehicles, aircraft and ships because of their high efficiency and low emission of pollutants. The catalytical reforming with subsequent gas processing units is applied to operate the fuel cell system with onboard available fuels. Within the reformer the liquid fuel is converted into a hydrogen-rich synthesis gas in the presence of metal catalysts. However, an on-board desulfurization of fuels is required to avoid the deactivation of catalysts in the fuel processing unit as well as in the fuel cell. The present work aims at developing a technically feasible deep desulfurization process for fuel cell powered APUs with theoretical and experimental study as well as procedural analysis. The focus of the work is on the desulfurization of jet fuels in liquid phase, since the reformer currently developed in IEK-3 is designed for aviation applications of fuel cell APUs and it can only be operated by liquid jet fuels. In addition, the desulfurization of marine gas oil was investigated to fulfill the sulfur requirement of the fuels for the application of fuel cell A PUs for inland navigation. In the petroleum industry, low-sulfur fuels are often obtained by hydrodesulfurization and the S-Zorb Process. However, these conventional methods are highly inconvenient for reducing sulfur compounds to the desired level in a mobile fuel cell system, since improvements of the desulfurization efficiency are limited by increasingly severe operating conditions and escalating costs. Moreover, the hydrodesulfurization and the S-Zorb Process are not suitable for mobile applications, since hydrogen recycling is required, which is not possible with H{sub 2} syngas. To this end, a large number of processes discussed in the literature were assessed with regard to their application in fuel cell APUs. Three potentially suitable processes were selected: pervaporation, adsorption, and hydrodesulfurization with pre

Research on the combustion, energy and emission parameters of diesel fuel and a biomass-to-liquid (BTL) fuel blend in a compression-ignition engine

International Nuclear Information System (INIS)

Rimkus, Alfredas; Žaglinskis, Justas; Rapalis, Paulius; Skačkauskas, Paulius

2015-01-01

Highlights: • Researched physical–chemical and performance properties of diesel fuel and BTL blend (85/15 V/V). • BTL additive reduced Brake Specific Fuel Consumption, improved engine efficiency. • Simpler BTL molecular chains and lower C/H ratio reduced CO_2 emission and smokiness. • Higher cetane number of BTL reduced heat release in beginning of combustion and NO_x emission. • Advanced start of fuel injection caused reduced fuel consumption and smokiness, increased NO_x emission. - Abstract: This paper presents the comparable research results of the physical–chemical and direct injection (DI) diesel engine properties of diesel fuel and BTL (biomass-to-liquid) blend (85/15 V/V). The energy, ecological and in-cylinder parameters were analysed under medium engine speed and brake torque load regimes; the start of fuel injection was also adjusted. After analysis of the engine bench tests and simulation with AVL BOOST software, it was observed that the BTL additive shortened the fuel ignition delay phase, reduced the heat release in the pre-mixed intensive combustion phase, reduced the nitrogen oxide (NO_x) concentration in the engine exhaust gases and reduced the thermal and mechanical load of the crankshaft mechanism. BTL additive reduced the rates of carbon dioxide (CO_2), incompletely burned hydrocarbons (HC) emission and smokiness due to its chemical composition and combustion features. BTL also reduced Brake Specific Fuel Consumption (BSFC, g/kW h) and improved engine efficiency (η_e); however, the volumetric fuel consumption changed due to the lower density of BTL. The start of fuel injection was adjusted for maximum engine efficiency; concomitantly, reductions in the CO_2 concentration, HC concentration and smokiness were achieved. However, the NO_x and thermo-mechanical engine load increased.

Assessing GHG emissions, ecological footprint, and water linkage for different fuels.

Science.gov (United States)

Chavez-Rodriguez, Mauro F; Nebra, Silvia A

2010-12-15

Currently, transport is highly dependent on fossil fuels and responsible for about 23% of world energy-related GHG (greenhouse gas) emissions. Ethanol from sugar cane and corn emerges as an alternative for gasoline in order to mitigate GHG emissions. Additionally, deeper offshore drilling projects such as in the Brazilian Pre-Salt reservoirs and mining projects of nonconventional sources like Tar Sands in Canada could be a solution for supplying demand of fossil fuels in the short and midterm. Based on updated literature, this paper presents an assessment of GHG emissions for four different fuels: ethanol from sugar cane and from corn and gasoline from conventional crude oil and from tar sands. An Ecological Footprint analysis is also presented, which shows that ethanol from sugar cane has the lowest GHG emissions and requires the lowest biocapacity per unit of energy produced among these fuels. Finally, an analysis using the Embodied Water concept is made with the introduction of a new concept, the "CO(2)-Water", to illustrate the impacts of releasing carbon from underground to atmosphere and of the water needed to sequestrate it over the life cycle of the assessed fuels. Using this method resulted that gasoline from fossil fuels would indirectly "require" on average as much water as ethanol from sugar cane per unit of fuel energy produced.

Application of CO{sub 2} selective membrane reactors in pre-combustion decarbonisation systems for power production

Energy Technology Data Exchange (ETDEWEB)

Steven C.A. Kluiters; Virginie C. Feuillade; Jan Wilco Dijkstra; Daniel Jansen; Wim G. Haije [Energy research Centre of the Netherlands (ECN), Petten (Netherlands)

2006-07-01

For pre-combustion decarbonisation of fuels for large-scale power production or H{sub 2} generation both CO{sub 2} and H{sub 2} selective membranes are viable candidates for use in steam reforming and water gas shift membrane reactors. It will be shown that the choice between either option is not a matter of taste, but dictated by the fuel used and, to a lesser extent, the total system layout. Hydrotalcites, clay-like materials, are shown to be promising candidates as membrane material for low temperature, below 400{sup o}C, membrane shift reactors. 7 refs., 6 figs., 1 tab.

Data mining in the study of nuclear fuel cells

International Nuclear Information System (INIS)

Medina P, J. A.; Ortiz S, J. J.; Castillo, A.; Montes T, J. L.; Perusquia, R.

2015-09-01

In this paper is presented a study of data mining application in the analysis of fuel cells and their performance within a nuclear boiling water reactor. A decision tree was used to fulfill questions of the type If (condition) and Then (conclusion) to classify if the fuel cells will have good performance. The performance is measured by compliance or not of the cold shutdown margin, the rate of linear heat generation and the average heat generation in a plane of the reactor. It is assumed that the fuel cells are simulated in the reactor under a fuel reload and rod control patterns pre designed. 18125 fuel cells were simulated according to a steady-state calculation. The decision tree works on a target variable which is one of the three mentioned before. To analyze this objective, the decision tree works with a set of attribute variables. In this case, the attributes are characteristics of the cell as number of gadolinium rods, rods number with certain uranium enrichment mixed with a concentration of gadolinium, etc. The found model was able to predict the execution or not of the shutdown margin with a precision of around 95%. However, the other two variables showed lower percentages due to few learning cases of the model in which these variables were or were not achieved. Even with this inconvenience, the model is quite reliable and can be used in way coupled in optimization systems of fuel cells. (Author)

Axial design of fuel for BWRs using neural networks

International Nuclear Information System (INIS)

Ortiz, J.J.; Castillo, A.; Montes, J.L.; Perusquia, R.

2007-01-01

In this work a new system of axial optimization of fuel is presented based on a recurrent multi state neural net called RENODC. They are described with detail the main characteristics of this type of neural net (architecture, energy function and actualization of neural states) and like was adapted to the assemble design of nuclear fuel. The fuel design is proven by means of a fuel recharge and pre determined control rod patterns. By this way a good axial fuel design one has, when the thermal limits are fulfilled along the cycle, the reactor stays critic and at least the wanted longitude of the cycle is reached; also the margin of in cold turned off is verified. The assemble of fuel created with RENODC it is substituted by a recharge assemble and it is sought to verify that the energy requirements and aspects of safety are completed. The used cycle corresponds to a balance cycle of 18 months that it can be applied to the Laguna Verde Nucleo electric Central. The tests demonstrate the effectiveness of the system to reach satisfactory results in times of CPU of around 4 hours. This way, it could be proven that the design proposed with a lightly superior enrichment to that of the substituted design, fulfills the energy requirements. In later stages of this project this system will be coupled to the other optimization modules that are already had. (Author)

HTGR fuel and fuel cycle technology

International Nuclear Information System (INIS)

Lotts, A.L.; Homan, F.J.; Balthesen, E.; Turner, R.F.

1977-01-01

Significant advances have occurred in the development of HTGR fuel and fuel cycle. These accomplishments permit a wide choice of fuel designs, reactor concepts, and fuel cycles. Fuels capable of providing helium outlet temperatures of 750 0 C are available, and fuels capable of 1000 0 C outlet temperatures may be expected from extension of present technology. Fuels have been developed for two basic HTGR designs, one using a spherical (pebble bed) element and the other a prismatic element. Within each concept a number of variations of geometry, fuel composition, and structural materials are permitted. Potential fuel cycles include both low-enriched and high-enriched Th- 235 U, recycle Th- 233 U, and Th-Pu or U-Pu cycles. This flexibility offered by the HTGR is of great practical benefit considering the rapidly changing economics of power production. The inflation of ore prices has increased optimum conversion ratios, and increased the necessity of fuel recycle at an early date. Fuel element makeup is very similar for prismatic and spherical designs. Both use spherical fissile and fertile particles coated with combinations of pyrolytic carbon and silicon carbide. Both use carbonaceous binder materials, and graphite as the structural material. Weak-acid resin (WAR) UO 2 -UC 2 fissile fuels and sol-gel-derived ThO 2 fertile fuels have been selected for the Th- 233 U cycle in the prismatic design. Sol-gel-derived UO 2 UC 2 is the reference fissile fuel for the low-enriched pebble bed design. Both the United States and Federal Republic of Germany are developing technology for fuel cycle operations including fabrication, reprocessing, refabrication, and waste handling. Feasibility of basic processes has been established and designs developed for full-scale equipment. Fuel and fuel cycle technology provide the basis for a broad range of applications of the HTGR. Extension of the fuels to higher operating temperatures and development and commercial demonstration of fuel

Inhalation of Hydrocarbon Jet Fuel Suppress Central Auditory Nervous System Function.

Science.gov (United States)

Guthrie, O'neil W; Wong, Brian A; McInturf, Shawn M; Reboulet, James E; Ortiz, Pedro A; Mattie, David R

2015-01-01

More than 800 million L/d of hydrocarbon fuels is used to power cars, boats, and jet airplanes. The weekly consumption of these fuels necessarily puts the public at risk for repeated inhalation exposure. Recent studies showed that exposure to hydrocarbon jet fuel produces lethality in presynaptic sensory cells, leading to hearing loss, especially in the presence of noise. However, the effects of hydrocarbon jet fuel on the central auditory nervous system (CANS) have not received much attention. It is important to investigate the effects of hydrocarbons on the CANS in order to complete current knowledge regarding the ototoxic profile of such exposures. The objective of the current study was to determine whether inhalation exposure to hydrocarbon jet fuel might affect the functions of the CANS. Male Fischer 344 rats were randomly divided into four groups (control, noise, fuel, and fuel + noise). The structural and functional integrity of presynaptic sensory cells was determined in each group. Neurotransmission in both peripheral and central auditory pathways was simultaneously evaluated in order to identify and differentiate between peripheral and central dysfunctions. There were no detectable effects on pre- and postsynaptic peripheral functions. However, the responsiveness of the brain was significantly depressed and neural transmission time was markedly delayed. The development of CANS dysfunctions in the general public and the military due to cumulative exposure to hydrocarbon fuels may represent a significant but currently unrecognized public health issue.

Radiological and environmental safety aspects of uranium fuel fabrication plants at Nuclear Fuel Complex, Hyderabad

International Nuclear Information System (INIS)

Viswanathan, S.; Surya Rao, B.; Lakshmanan, A.R.; Krishna Rao, T.

1991-01-01

Nuclear Fuel Complex, Hyderabad manufactures uranium dioxide fuel assemblies for PHWRs and BWRs operating in India. Starting materials are magnesium diuranate received from UCIL, Jaduguda and imported UF. Both of these are converted to UO 2 pellets by identical chemical processes and mechanical compacting. Since the uranium handled here is free of daughter product activities, external radiation is not a problem. Inhalation of airborne U compounds is one of the main source of exposure. Engineered protective measures like enclosures around U bearing powder handling equipment and local exhausts reduce worker's exposure. Installation of pre-filters, wet rotoclones and electrostatic precipitators in the ventillation system reduces the release of U into the environment. The criticality hazard in handling slightly enriched uranium is very low due to the built-in control based on geometry and inventory. Where airborne uranium is significant, workers are provided with protective respirators. The workers are regularly monitored for external exposure and also for internal exposure. The environmental releases from the NFC facility is well controlled. Soil, water and air from the NFC environment are routinely collected and analysed for all the possible pollutants. The paper describes the Health Physics experience during the last five years on occupational exposures and on environmental surveillance which reveals the high quality of safety observed in our nuclear fuel fabricating installations. (author). 4 refs., 6 tabs

Constant strength fuel-fuel cell

International Nuclear Information System (INIS)

Vaseen, V.A.

1980-01-01

A fuel cell is an electrochemical apparatus composed of both a nonconsumable anode and cathode; and electrolyte, fuel oxidant and controls. This invention guarantees the constant transfer of hydrogen atoms and their respective electrons, thus a constant flow of power by submergence of the negative electrode in a constant strength hydrogen furnishing fuel; when said fuel is an aqueous absorbed hydrocarbon, such as and similar to ethanol or methnol. The objective is accomplished by recirculation of the liquid fuel, as depleted in the cell through specific type membranes which pass water molecules and reject the fuel molecules; thus concentrating them for recycle use

Il ruolo della robustezza strutturale nella impostazione ingegneristica della sicurezza antincendio

DEFF Research Database (Denmark)

Crosti, C.; Giuliani, Luisa; Gentili, F.

2012-01-01

contrastare il più possibile la diffusione dell’incendio stesso. Questa strategia si applica a tutti i livelli: fra un locale e l’altro all’interno di un piano, fra un piano e l’altro all’interno di un edificio, fra un edificio e l’altro all’interno di un isolato, fino alla scala urbana e finanche regionale...

Immobilization of preconditioned spent fuel from nuclear research reactors in a ceramic matrix

International Nuclear Information System (INIS)

Russo, Diego O.; Rodriguez, Diego S.; Heredia, Arturo D.; Sanfilippo, Miguel; Sterba, Mario E.; Mateos, Patricia

2002-01-01

The fuel elements from nuclear research reactors consist in a laminated sandwich of aluminum with a core of some uranium compound. To process this material its necessary to previously eliminate the aluminum covering the fuel, before the conditioning of the rest of the fuel in a stable matrix, in order to obtain an acceptable waste form for a subsequent disposition in a geological repository. Normally, mechanical and chemical methods are proposed for that purpose. One of the most developed techniques for immobilization of the radioactive elements above mentioned, is the vitrification. In this work we propose a method named CERUS (in Spanish Ceramizacion de Elementos Radiactivos con Uranio Sinterizado - Ceramization of radioactive elements with sintered uranium). This is a sinterization of the pre-treated fuel elements mixed with natural uranium oxide. The properties of the blocks obtained are adequate for final disposal in a deep geological reservoir. (author)

Major results on the development of high density U-Mo fuel and pin-type fuel elements executed under the Russian RERTR program and in cooperation with ANL (USA)

International Nuclear Information System (INIS)

Vatulin, A.; Morozov, A.; Stetsky, Y.; Suprun, V.; Dobrikova, I.; Trifonov, Y.; Mishunin, V.; Sorokin, V.

2003-01-01

VNIINM is active participant of 'Russian program on Reduced Enrichment for Research and Test Reactors'. Institute Works in two main directions: 1) development of new high-density fuels (HDF) and 2) development of new design of fuel elements with LEU. The development of the new type fuel element is carried out both for existing reactors, and for developing new advanced reactors. The 'TVEL' concern is coordinator of works of this program. The majority enterprises of branch (NIIAR, PIYaF, RRC KI, NZChK) take part in this work. Since 2000 these works are being conducted in cooperation with Argonne National Laboratory (USA) within the RERTR program under VNIINM with ANL contract. At the present, a large set of pre-pile investigations has been completed. All necessary fabrication procedures have been developed for utilization of U-Mo dispersion fuel in Russian-designed research reactors. For irradiation tests the pin-type mini-fuel elements with HDF dispersion fuel with LEU and the uranium density equaled to 4,0 and 6,0 g/cm 3 (up to 40 vol.%) have been manufactured. Their irradiation began in August 2003 in the MIR reactor (NIIAR, Dimitrovgrad). A large set of works for preparation of lifetime tests (WWR-M reactor in Gatchina) of two full-scale fuel assemblies with new pin-type fuel elements on basis LEU UO 2 -Al and UMo-Al fuels has been completed. The in-pile tests of fuel assemblies began in September 2003. The summary of important results of performed works and their near-term future are presented in paper. (author)

Rethinking the economics of centralized spent fuel storage

International Nuclear Information System (INIS)

Wood, T.W.; Short, S.M.; Dippold, D.G.; Rod, S.R.; Williams, J.W.

1991-01-01

The technology for extended storage of spent nuclear fuel (SNF), either at-reactor or in a centralized facility such as a monitored retrievable storage (MRS) facility, is well-developed and proven from an engineering and safety perspective. The question of whether spent fuel should await its final geologic disposal while at a reactor site or in an MRS facility is essentially an economic one. While intuition and previous results suggest that centralized storage will be more economical than at-reactor storage beyond some break-even quantity of SNF, the incremental costs of pool storage at-reactor are close to zero as long as pool capacity is generally available. Thus, if economics is the prime motivator, the quantity of spent fuel required to warrant centralized storage could be quite large. The economics of centralizing the storage of spent fuel at a single site, as opposed to continued storage at over 100 reactor sites, has been the subject of several recent analyses. Most of these analyses involved calculating the benefits of an MRS facility (in terms of avoided utility costs) with a pre-defined MRS operating scenario (e.g., spent fuel acceptance schedule, storage capacity, and typical storage cycle). While these analyses provided some insight into the economic justification for an MRS facility, even the most favorable scenarios resulted in net costs of hundreds of millions of dollars when evaluated on a discounted cash flow basis

Pre-Stretched Low Equivalent Weight PFSA Membranes with Improved Fuel Cell Performance

DEFF Research Database (Denmark)

Zhang, Wenjing (Angela); Wycisk, Ryszard; Kish, Daniel L.

2014-01-01

for the morphological changes to be permanent. For 825 EW PFSA, stretching increased the polymer crystallinity by 22.5%, with a reduction in methanol permeability and a small increase in proton conductivity. In direct methanol fuel cell tests at 60◦C with 1.0 M methanol, the power density at 0.4 V with a DR = 4...... stretched 825 EW membrane (72 mW/cm2) was considerably greater than that obtained with a solution-cast membrane (28 mW/cm2) or with a commercial Nafion 117 membrane (55 mW/cm2). For 733 EW PFSA, stretching promoted the formation of ordered ionic domains leading to an increase in proton conductivity...

Funzioni del tempo presente nella strategia narrativa

Directory of Open Access Journals (Sweden)

Aleksandra Koman

2017-08-01

Full Text Available La scelta del tempo verbale adatto a una determinata situazione dipende dal rapporto tra il momento dell’avvenimento e quello dell’enunciazione. Se coincidono abbiamo a che fare con il tempo presente (Bertinetto. È necessario, però, ricordare che il presente è in grado di riferirsi agli eventi passati come accade spesso nei testi narrativi. Per capire lo scopo di questa scelta si sono analizzati diversi tipi di scrittura comprovanti che il presente nella narrativa può servire a sottolineare la posizione temporale del narratore (Il fu Mattia Pascal; a evidenziare un momento importante dal punto di vista dello svolgimento dell’azione (Se questo è un uomo; a costruire descrizioni (Vita oppure far entrare il lettore nel vivo del racconto (Gli Italiani in Polonia nei secoli, dando l’impressione che egli sia un testimone diretto degli eventi raccontati.

Greenhouse gases in the life cycle of fossil fuels: critical aspects in upstream emissions estimate and their repercussions on the overall life-cycle

International Nuclear Information System (INIS)

Zerlia, Tiziana

2004-01-01

Combustion accounts for the main contribution to greenhouse-gas (GHG) emissions in electricity generation via fossil fuels. To date, minor attention has been paid to pre combustion emissions associated with fossil fuel upstream segment (production, processing and transportation). This study seeks to provide insight into GHG emissions in the pre combustion step of natural gas and coal. Owing to the size/complexity of the upstream processes and to a lack of detailed site-specific data, this study just outlines some of the key aspects involved. The attention will be focused on the elements that may have a significant impact on fossil fuel life-cycle and no on the evaluation of GHG: the sources, the extent of the pre combustion GHG emissions and the accuracy of their estimate. Some key results are summarized in the following. The first one is that pre combustion GHG, owing of the huge Italy reliance on fossil fuels imports, are mainly emitted abroad. In addition, they are released to the atmosphere mainly as fugitive emissions (methane and carbon dioxide being the predominant gases). Moreover, although pre combustion emissions give a modest contribution to GHG of the whole energy sector, they may account for a consistent part of the aver all fuel life-cycle in power generation even though combustion technologies efficiency plays a key role in emission reduction. Some examples are reported, showing the potential impact of pre combustion emissions on coal and natural gas life-cycle in Italy's electricity generation. The second one is that pre combustion emissions are very site specific as they depend on several factors which may vary greatly between countries and even between individual companies. The sources and the extent of upstream emissions are in fact a function of a least three factor types: (a) technical parameters (design and operating practices, process operating conditions, efficiency of potential emission control/reduction equipment, age and conditions of

Sol-gel process for thermal reactor fuel fabrication

International Nuclear Information System (INIS)

Mukerjee, S.K.

2008-01-01

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

Performance effects of coal-derived contaminants on the carbonate fuel cell

Energy Technology Data Exchange (ETDEWEB)

Pigeaud, A. [Energy Research Corp., Danbury, CT (United States); Wilemski, G. [Physical Sciences, Inc., Andover, MA (United States)

1993-05-01

Coal-derived contaminant studies have been pursued at ERC since the early 1980`s when the pace of carbonate fuel cell development began to markedly increase. Initial work was concerned with performance effects on laboratory and bench-scale carbonate fuel cells primarily due to sulfur compounds. Results have now also been obtained with respect to nine additional coal-gas contaminants, including volatile trace metal species. Thermochemical calculations, out-of-cell experiments, and cell performance as well as endurance testshave recently been conducted which have involved the following species: NH{sub 3}, H{sub 2}S [COS], HCl, AsH{sub 3}[As{sub 2}(v)], Zn(v), Pb(v), Cd(v), H{sub 2} Se, Hg(v), Sn(v). Employing thermochemically calculated results, thermogravimetric (TGA) and pre-, and post-test analytical data as well as fuel cell performance observations, it has been shown that there are four main mechanisms of contaminant interaction with the carbonate fuel cell. These have been formulated into performance models for six significant contaminant species, thus providing long-term endurance estimations.

Performance effects of coal-derived contaminants on the carbonate fuel cell

Energy Technology Data Exchange (ETDEWEB)

Pigeaud, A. (Energy Research Corp., Danbury, CT (United States)); Wilemski, G. (Physical Sciences, Inc., Andover, MA (United States))

1993-01-01

Coal-derived contaminant studies have been pursued at ERC since the early 1980's when the pace of carbonate fuel cell development began to markedly increase. Initial work was concerned with performance effects on laboratory and bench-scale carbonate fuel cells primarily due to sulfur compounds. Results have now also been obtained with respect to nine additional coal-gas contaminants, including volatile trace metal species. Thermochemical calculations, out-of-cell experiments, and cell performance as well as endurance testshave recently been conducted which have involved the following species: NH[sub 3], H[sub 2]S [COS], HCl, AsH[sub 3][As[sub 2](v)], Zn(v), Pb(v), Cd(v), H[sub 2] Se, Hg(v), Sn(v). Employing thermochemically calculated results, thermogravimetric (TGA) and pre-, and post-test analytical data as well as fuel cell performance observations, it has been shown that there are four main mechanisms of contaminant interaction with the carbonate fuel cell. These have been formulated into performance models for six significant contaminant species, thus providing long-term endurance estimations.

Fuels processing for transportation fuel cell systems

Science.gov (United States)

Kumar, R.; Ahmed, S.

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

Direct-injection strategies for a hydrogen-fueled engine : an optical and numerical investigation

Energy Technology Data Exchange (ETDEWEB)

Kaiser, S.; Salazar, V. [Sandia National Labs, Albuquerque, NM (United States); Scarcelli, R.; Wallner, T. [Argonne National Lab, Argonne, IL (United States)

2009-07-01

Vehicles with hydrogen-fueled engines are competitive with systems based on fuel cells. There is a lack of fundamental knowledge about in-cylinder processes in hydrogen direct injection engines. This presentation discussed a study that used a variety of injector configurations to establish a broad database. A light-load conditions that can profit from stratification was investigated. Several results were presented, including the 5-hole nozzle produced an asymmetric jet pattern which may be good for late injection. Very lean regions in the wake of the transient jets were found to be similar to those found in diesel injection. The 13-hole nozzle demonstrated complete jet collapse, consistent with Schlieren imaging by Petersen. Stratification made efficiency sensitive to the targeting of the single-hole injector. Computational fluid dynamics with a commercially available code aimed to improve the process of design optimization. The simulation predicted less fuel dispersion than was experimentally measured. Details of the fuel penetration were captured. It was concluded that for the single-hole nozzle, the pre-spark fuel distribution is consistent with results from the fired engine. tabs., figs.

New concept for low emission diesel combustion. 2nd Report. Combustion improvement by applying EGR and oxygenated fuel; Teikogai diesel engine no nensho concept. EGR, gansanso nenryo ni yoru nensho kaizen

Energy Technology Data Exchange (ETDEWEB)

Yokota, H.; Nakajima, H.; Kakegawa, T. [Hino Motors, Ltd., Tokyo (Japan)

1998-05-01

Described herein are performance of a new concept of premixed, multiple injection combustion, in which part of the fuel is injected into the combustion chamber at the early stage and the remainder is injected in the ordinary manner, and characteristics of the exhaust gases. Also described are the effects of EGR and oxygenated fuel on reduced HC emissions and fuel consumption. The ordinary premixed, multiple injection combustion system has problems related to fuel efficiency, and HC and particulate missions. When combined with an EGR system, this system reduces HC emissions to one-third. MTBE shows an effect of improving fuel efficiency, when mixed with diesel fuel. No particulate matter is exhausted and fuel efficiency is improved by 6%, when MTBE is present in the fuel at 30% by weight. The pre-mixture is less homogeneous in the absence of EGR and oxygenated fuel, producing a luminous flame observed in the fuel-rich region. No such a flame is observed, when MTBE is added to the fuel and suction air temperature is increased to the level corresponding to that associated with EGR, conceivably resulting from increased suction air temperature and lower boiling point of MTBE, which together make the pre-mixture leaner and more homogeneous. 7 refs., 9 figs., 2 tabs.

High dose stainless steel swelling data on interior and peripheral oxide fuel pins

International Nuclear Information System (INIS)

Boltax, A.; Foster, J.P.; Nayak, U.P.

1983-01-01

High dose (2 x 10 23 n/cm 2 , E > 0.1 Mev) swelling data obtained on 20% cold-worked AISI 316 stainless steel (N-lot) cladding from mixed-oxide fuel pins show large differences in swelling incubation dose due to pre-incubation dose temperature changes. Circumferential swelling variations of 1.5 to 4 times were found in peripheral fuel pin cladding which experienced 30 to 60 deg C temperature changes due to movement in a temperature gradient. Consideration is given to the implications of these results to low swelling materials development and core design. (author)

Constraints of fossil fuels depletion on global warming projections

International Nuclear Information System (INIS)

Chiari, Luca; Zecca, Antonio

2011-01-01

A scientific debate is in progress about the intersection of climate change with the new field of fossil fuels depletion geology. Here, new projections of atmospheric CO 2 concentration and global-mean temperature change are presented, should fossil fuels be exploited at a rate limited by geological availability only. The present work starts from the projections of fossil energy use, as obtained from ten independent sources. From such projections an upper bound, a lower bound and an ensemble mean profile for fossil CO 2 emissions until 2200 are derived. Using the coupled gas-cycle/climate model MAGICC, the corresponding climatic projections out to 2200 are obtained. We find that CO 2 concentration might increase up to about 480 ppm (445-540 ppm), while the global-mean temperature increase w.r.t. 2000 might reach 1.2 deg. C (0.9-1.6 deg. C). However, future improvements of fossil fuels recovery and discoveries of new resources might lead to higher emissions; hence our climatic projections are likely to be underestimated. In the absence of actions of emissions reduction, a level of dangerous anthropogenic interference with the climate system might be already experienced toward the middle of the 21st century, despite the constraints imposed by the exhaustion of fossil fuels. - Highlights: → CO 2 and global temperature are projected under fossil fuels exhaustion scenarios. → Temperature is projected to reach a minimum of 2 deg. C above pre-industrial. → Temperature projections are possibly lower than the IPCC ones. → Fossil fuels exhaustion will not avoid dangerous global warming.

Constraints of fossil fuels depletion on global warming projections

Energy Technology Data Exchange (ETDEWEB)

Chiari, Luca, E-mail: chiari@science.unitn.it [Department of Physics, University of Trento, Via Sommarive 14, 38123 Povo (Italy); Zecca, Antonio, E-mail: zecca@science.unitn.it [Department of Physics, University of Trento, Via Sommarive 14, 38123 Povo (Italy)

2011-09-15

A scientific debate is in progress about the intersection of climate change with the new field of fossil fuels depletion geology. Here, new projections of atmospheric CO{sub 2} concentration and global-mean temperature change are presented, should fossil fuels be exploited at a rate limited by geological availability only. The present work starts from the projections of fossil energy use, as obtained from ten independent sources. From such projections an upper bound, a lower bound and an ensemble mean profile for fossil CO{sub 2} emissions until 2200 are derived. Using the coupled gas-cycle/climate model MAGICC, the corresponding climatic projections out to 2200 are obtained. We find that CO{sub 2} concentration might increase up to about 480 ppm (445-540 ppm), while the global-mean temperature increase w.r.t. 2000 might reach 1.2 deg. C (0.9-1.6 deg. C). However, future improvements of fossil fuels recovery and discoveries of new resources might lead to higher emissions; hence our climatic projections are likely to be underestimated. In the absence of actions of emissions reduction, a level of dangerous anthropogenic interference with the climate system might be already experienced toward the middle of the 21st century, despite the constraints imposed by the exhaustion of fossil fuels. - Highlights: > CO{sub 2} and global temperature are projected under fossil fuels exhaustion scenarios. > Temperature is projected to reach a minimum of 2 deg. C above pre-industrial. > Temperature projections are possibly lower than the IPCC ones. > Fossil fuels exhaustion will not avoid dangerous global warming.

Thermal-hydraulic analyses of the TN-24P cask loaded with consolidated and unconsolidated spent nuclear fuel

International Nuclear Information System (INIS)

Michener, T.E.; McKinnon, M.A.; Rector, D.R.; Creer, J.M.

1989-06-01

This paper presents the results of comparisons of COBRA-SFS (spent fuel storage) temperature predictions with experimental data from the TN-24P (Transnuclear) spent fuel storage cask loaded with unconsolidated and consolidated spent PWR fuel. Peak cladding temperature predictions using the COBRA-SFS code are compared with test data and predicted axial and radial temperature distributions are compared with measured temperature profiles. The pre-test accuracy of the COBRA-SFS code in predicting temperature distributions is discussed, along with the effect of post-test model improvements on temperature predictions. This paper also briefly describes the COBRA-SFS code, which is designed to accurately predict flow and temperature distributions in spent nuclear fuel storage and transportation systems. 6 refs., 14 figs

Scientific basis for storage criteria for interim dry storage of aluminum-clad fuels

International Nuclear Information System (INIS)

Sindelar, R.L.; Peacock, H.B. Jr.; Lam, P.S.; Iyer, N.C.; Louthan, M.R. Jr.; Murphy, J.R.

1996-01-01

An engineered system for dry storage of aluminum-clad foreign and domestic research reactor spent fuel owned by the US Department of Energy is being considered to store the fuel up to a nominal period of 40 years prior to ultimate disposition. Scientifically-based criteria for environmental limits to drying and storing the fuels for this system are being developed to avoid excessive degradation in sealed and non-sealed (open to air) dry storage systems. These limits are based on consideration of degradation modes that can cause loss of net section of the cladding, embrittlement of the cladding, distortion of the fuel, or release of fuel and fission products from the fuel/clad system. Potential degradation mechanisms include corrosion mechanisms from exposure to air and/or sources of humidity, hydrogen blistering of the aluminum cladding, distortion of the fuel due to creep, and interdiffusion of the fuel and fission products with the cladding. The aluminum-clad research reactor fuels are predominantly highly-enriched aluminum uranium alloy fuel which is clad with aluminum alloys similar to 1100, 5052, and 6061 aluminum. In the absence of corrodant species, degradation due to creep and diffusion mechanisms limit the maximum fuel storage temperature to 200 C. The results of laboratory scale corrosion tests indicate that this fuel could be stored under air up to 200 C at low relative humidity levels (< 20%) to limit corrosion of the cladding and fuel (exposed to the storage environment through assumed pre-existing pits in the cladding). Excessive degradation of fuels with uranium metal up to 200 C can be avoided if the fuel is sufficiently dried and contained in a sealed system; open storage can be achieved if the temperature is controlled to avoid excessive corrosion even in dry air

Technology Implementation Plan: Irradiation Testing and Qualification for Nuclear Thermal Propulsion Fuel

Energy Technology Data Exchange (ETDEWEB)

Harrison, Thomas J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Howard, Richard H. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Rader, Jordan D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2017-09-01

This document is a notional technology implementation plan (TIP) for the development, testing, and qualification of a prototypic fuel element to support design and construction of a nuclear thermal propulsion (NTP) engine, specifically its pre-flight ground test. This TIP outlines a generic methodology for the progression from non-nuclear out-of-pile (OOP) testing through nuclear in-pile (IP) testing, at operational temperatures, flows, and specific powers, of an NTP fuel element in an existing test reactor. Subsequent post-irradiation examination (PIE) will occur in existing radiological facilities. Further, the methodology is intended to be nonspecific with respect to fuel types and irradiation or examination facilities. The goals of OOP and IP testing are to provide confidence in the operational performance of fuel system concepts and provide data to program leadership for system optimization and fuel down-selection. The test methodology, parameters, collected data, and analytical results from OOP, IP, and PIE will be documented for reference by the NTP operator and the appropriate regulatory and oversight authorities. Final full-scale integrated testing would be performed separately by the reactor operator as part of the preflight ground test.

FY 2014 Status Report: of Vibration Testing of Clad Fuel (M4FT-14OR0805033)

Energy Technology Data Exchange (ETDEWEB)

Bevard, Bruce Balkcom [ORNL

2014-03-28

The DOE Used Fuel Disposition Campaign (UFDC) tasked Oak Ridge National Laboratory (ORNL) to investigate the behavior of light-water-reactor (LWR) fuel cladding material performance related to extended storage and transportation of UNF. ORNL has been tasked to perform a systematic study on UNF integrity under simulated normal conditions of transportation (NCT) by using the recently developed hot-cell testing equipment, Cyclic Integrated Reversible-Bending Fatigue Tester (CIRFT). To support the testing on actual high-burnup UNF, fast-neutron irradiation of pre-hydrided zirconium-alloy cladding in the High Flux Isotope Reactor (HFIR) at elevated temperatures will be used to simulate the effects of high-burnup on fuel cladding for help in understanding the cladding materials properties relevant to extended storage and subsequent transportation. The irradiated pre-hydrided metallic materials testing will generate baseline data to benchmark hot-cell testing of the actual high-burnup UNF cladding. More importantly, the HFIR-irradiated samples will be free of alpha contamination and can be provided to researchers who do not have hot cell facilities to handle highly contaminated high-burnup UNF cladding to support their research projects for the UFDC.

Particle fueling experiments with a series of pellets in LHD

Science.gov (United States)

Baldzuhn, J.; Damm, H.; Dinklage, A.; Sakamoto, R.; Motojima, G.; Yasuhara, R.; Ida, K.; Yamada, H.; LHD Experiment Group; Wendelstein 7-X Team

2018-03-01

Ice pellet injection is performed in the heliotron Large Helical Device (LHD). The pellets are injected in short series, with up to eight individual pellets. Parameter variations are performed for the pellet ice isotopes, the LHD magnetic configurations, the heating scenario, and some others. These experiments are performed in order to find out whether deeper fueling can be achieved with a series of pellets compared to single pellets. An increase of the fueling efficiency is expected since pre-cooling of the plasma by the first pellets within a series could aid deeper penetration of later pellets in the same series. In addition, these experiments show which boundary conditions must be fulfilled to optimize the technique. The high-field side injection of pellets, as proposed for deep fueling in a tokamak, will not be feasible with the same efficiency in a stellarator or heliotron because there the magnetic field gradient is smaller than in a tokamak of comparable size. Hence, too shallow pellet fueling, in particular in a large device or a fusion reactor, will be an issue that can be overcome only by extremely high pellet velocities, or other techniques that will have to be developed in the future. It turned out by our investigations that the fueling efficiency can be enhanced by the injection of a series of pellets to some extent. However, further investigations will be needed in order to optimize this approach for deep particle fueling.

Reaction in air and in nitrogen of pre-oxidised Zircaloy-4 and M5™ claddings

Energy Technology Data Exchange (ETDEWEB)

Duriez, C., E-mail: christian.duriez@irsn.fr [Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PSN-RES/SEREX-LE2M, Centre de Cadarache, St Paul-Lez-Durance 13115 (France); Drouan, D. [Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PSN-RES/SEREX-LE2M, Centre de Cadarache, St Paul-Lez-Durance 13115 (France); Pouzadoux, G. [Université Technologique de Troyes, BP 2060, Troyes 10010 (France)

2013-10-15

High temperature reactivity in air and in nitrogen of pre-oxidised Zircaloy-4 and M5™ claddings has been studied by thermogravimetry. Claddings were pre-oxidised at low temperature with the aim of simulating spent fuel. Different pre-oxidation modes, inducing significant variation in the pre-oxides microstructure, were compared. The behaviour in air, investigated in the 850–1000 °C temperature range, was found to be strongly dependant on the type of pre-oxide: the compact pre-oxide formed in autoclave (at temperature, pressure, and water chemistry representative of PWR conditions) significantly slows down the degradation in air compared to the bare alloys; on the contrary, a pre-oxide formed at 500 °C at ambient pressure, either in oxygen or in steam, favours the initiation of post-breakaway type oxidation, which in air is associated with nitride formation. The behaviour in nitrogen has been investigated in the 800–1200 °C temperature range, with Zircaloy-4 pre-oxidised at 500 °C in O{sub 2}. Reactivity is low up to 1000 °C but becomes very significant at the highest temperatures investigated, 1100 and 1200 °C. Finally, cladding segments first reacted in N{sub 2} at 1100 °C, were exposed to air and show fast oxidation even at the lowest temperature investigated (600 °C)

Development of System Engineering Technology for Nuclear Fuel Cycle

International Nuclear Information System (INIS)

Kim, Ho Dong; Kim, Sung Ki; Song, Kee Chan

2010-04-01

This report is aims to establish design requirements for constructing mock-up system of pyroprocess by 2011 to realize long-term goal of nuclear energy promotion comprehensive plan, which is construction of engineering scale pyroprocess integrated process demonstration facility. The development of efficient process for spent fuel and establishment of system engineering technology to demonstrate the process are required to develop nuclear energy continuously. The detailed contents of research for these are as follows; - Design of Mock-up facility for demonstrate pyroprocess, Construction, Approval, Trial run, Performance test - Development of nuclear material accountancy technology for unit processes of pyroprocess and design of safeguards system - Remote operation of demonstrating pyroprocess / Development of maintenance technology and equipment - Establishment of transportation system and evaluation of pre-safety for interim storage system - Deriving and implementation of a method to improve nuclear transparency for commercialization proliferation resistance nuclear fuel cycle Spent fuel which is the most important pending problem of nuclear power development would be reduced and recycled by developing the system engineering technology of pyroprocess facility by 2010. This technology would contribute to obtain JD for the use of spent fuel between the ROK-US and to amend the ROK-US Atomic Energy Agreement scheduled in 2014

Development of 3-Pin Fuel Test Loop and Utilization Technology

International Nuclear Information System (INIS)

Lee, Chung Young; Sim, B. S.; Lee, C. Y.

2007-06-01

The principal contents of this project are to design, fabricate and install the steady-state fuel test loop in HANARO for nuclear technology development. Procurement and, fabrication of main equipment, licensing and installation for fuel test loop have been performed. Following contents are described in the report. 1. Design - Design of the In-pile system and Out pile system 2. Fabrication and procurement of the equipment - Fabrication of the In-pile system and In-pool piping - Fabrication and procurement of the equipment of the out-pile system 3. Acquisition of the license - Preparation of the safety analysis report and acquisition of the license - Pre-service inspection of the facility 4. Installation and commissioning - Installation of the FTL - Development of the commissioning procedure

Aerial infrared monitoring for nuclear fuel cycle facilities in Ukraine

International Nuclear Information System (INIS)

Stankevich, S.A.; Dudar, T.V.; Kovalenko, G.D.; Kartashov, V.V.

2015-01-01

The scientific research overall objective is rapid express detection and preliminary identification of pre-accidental conditions at nuclear fuel cycle facilities. We consider development of a miniature unmanned aerial vehicle equipped with high-precision infrared spectroradiometer able to detect remotely internal warming up of hazardous facilities by its thermal infrared radiation. The possibility of remote monitoring using unmanned aerial vehicle is considered at the example of the dry spent fuel storage facility of the Zaporizhzhya Nuclear Power Plant. Infrared remote monitoring is supposed to present additional information on the monitored facilities based on different physical principles rather than those currently in use. Models and specifications towards up-to-date samples of infrared surveying equipment and its small-sized unmanned vehicles are presented in the paper.

Description and characterization of BRPR series S-0, S-1, S-2, S-3, and S-4 demonstration fuel rods

International Nuclear Information System (INIS)

Welty, R.K.

1981-07-01

This report describes the process development, fabrication, and pre-irradiation characterization of the demonstration fuel rods for irradiation in the Big Rock Point Reactor as part of the DOE-sponsored Fuel Performance Improvement Program (FPIP). The fuel rods represent advanced designs that are expected to exhibit improved performance with respect to pellet-cladding-interaction and the attainment of extended burnup. Whereas other design variations are described, the primary fuel concepts being evaluated as part of the FPIP are an annular-coated-pressurized design and, at a more modest level, a sphere-pac design. A solid-pellet reference design provides the basis for comparing irradiation behavior

Landscape variation in tree regeneration and snag fall drive fuel loads in 24-year old post-fire lodgepole pine forests.

Science.gov (United States)

Nelson, Kellen N; Turner, Monica G; Romme, William H; Tinker, Daniel B

2016-12-01

Escalating wildfire in subalpine forests with stand-replacing fire regimes is increasing the extent of early-seral forests throughout the western USA. Post-fire succession generates the fuel for future fires, but little is known about fuel loads and their variability in young post-fire stands. We sampled fuel profiles in 24-year-old post-fire lodgepole pine (Pinus contorta var. latifolia) stands (n = 82) that regenerated from the 1988 Yellowstone Fires to answer three questions. (1) How do canopy and surface fuel loads vary within and among young lodgepole pine stands? (2) How do canopy and surface fuels vary with pre- and post-fire lodgepole pine stand structure and environmental conditions? (3) How have surface fuels changed between eight and 24 years post-fire? Fuel complexes varied tremendously across the landscape despite having regenerated from the same fires. Available canopy fuel loads and canopy bulk density averaged 8.5 Mg/ha (range 0.0-46.6) and 0.24 kg/m 3 (range: 0.0-2.3), respectively, meeting or exceeding levels in mature lodgepole pine forests. Total surface-fuel loads averaged 123 Mg/ha (range: 43-207), and 88% was in the 1,000-h fuel class. Litter, 1-h, and 10-h surface fuel loads were lower than reported for mature lodgepole pine forests, and 1,000-h fuel loads were similar or greater. Among-plot variation was greater in canopy fuels than surface fuels, and within-plot variation was greater than among-plot variation for nearly all fuels. Post-fire lodgepole pine density was the strongest positive predictor of canopy and fine surface fuel loads. Pre-fire successional stage was the best predictor of 100-h and 1,000-h fuel loads in the post-fire stands and strongly influenced the size and proportion of sound logs (greater when late successional stands had burned) and rotten logs (greater when early successional stands had burned). Our data suggest that 76% of the young post-fire lodgepole pine forests have 1,000-h fuel loads that exceed levels

Estimation of wildfire size and risk changes due to fuels treatments

Science.gov (United States)

Cochrane, M.A.; Moran, C.J.; Wimberly, M.C.; Baer, A.D.; Finney, M.A.; Beckendorf, K.L.; Eidenshink, J.; Zhu, Z.

2012-01-01

Human land use practices, altered climates, and shifting forest and fire management policies have increased the frequency of large wildfires several-fold. Mitigation of potential fire behaviour and fire severity have increasingly been attempted through pre-fire alteration of wildland fuels using mechanical treatments and prescribed fires. Despite annual treatment of more than a million hectares of land, quantitative assessments of the effectiveness of existing fuel treatments at reducing the size of actual wildfires or how they might alter the risk of burning across landscapes are currently lacking. Here, we present a method for estimating spatial probabilities of burning as a function of extant fuels treatments for any wildland fire-affected landscape. We examined the landscape effects of more than 72 000 ha of wildland fuel treatments involved in 14 large wildfires that burned 314 000 ha of forests in nine US states between 2002 and 2010. Fuels treatments altered the probability of fire occurrence both positively and negatively across landscapes, effectively redistributing fire risk by changing surface fire spread rates and reducing the likelihood of crowning behaviour. Trade offs are created between formation of large areas with low probabilities of increased burning and smaller, well-defined regions with reduced fire risk.

Recommendations for the nuclear fuel management in Mexico

International Nuclear Information System (INIS)

Ortega C, R.F.

2003-01-01

In this work some observations about the economic and strategic importance of the nuclear fuel management of a nucleo electric power station are presented, especially of the fuel management outside of the reactor core or supply function. We know that the economic competitiveness of the nucleo electric generation in fact resides in its low cost of fuel, in comparison with other alternative energy generation sources. Notwithstanding, frequently it is not given to this function the importance that should to have. The objective of this work is to focus again the mission of this activity, at view of the evolution and the peculiarities of the international markets of the nuclear fuel cycle. Equally a brief exhibition of the markets is made, from the uranium supply until the post- irradiation phase. In the case of the pre-irradiation phase we are in front of a market that the buyers dominate and that seemingly it will not present bigger problems in the next years, however situations exist like the decrease of the existent uranium inventories and the lack opening of new mines that can change the panorama. In relation with the post-irradiation phase, is necessary to study the strategies followed by other countries as the one uranium and plutonium recycled. As I have observed that the reality of that this passing in these markets and the practice of the fuel management, sometimes do not go of the hand, I have looked for to contribute some ideas and suggestions, on as going adapting this important function. (Author)

Production of fuel ethanol from steam-explosion pretreated olive tree pruning

Energy Technology Data Exchange (ETDEWEB)

Cristobal Cara; Encarnacion Ruiz; Mercedes Ballesteros; Paloma Manzanares; Ma Jose Negro; Eulogio Castro [University of Jaen, Jaen (Spain). Department of Chemical, Environmental and Materials Engineering

2008-05-15

This work deals with the production of fuel ethanol from olive tree pruning. This raw material is a renewable, low cost, largely available, and lacking of economic alternatives agricultural residue. Olive tree pruning was submitted to steam explosion pre-treatment in the temperature range 190-240{sup o}C, with or without previous impregnation by water or sulphuric acid solutions. The influence of both pre-treatment temperature and impregnation conditions on sugar and ethanol yields was investigated by enzymatic hydrolysis and simultaneous saccharification and fermentation on the pretreated solids. Results show that the maximum ethanol yield (7.2 g ethanol/100 g raw material) is obtained from water impregnated, steam pretreated residue at 240{sup o}C. Nevertheless if all sugars solubilized during pre-treatment are taken into account, up to 15.9 g ethanol/100 g raw material may be obtained (pre-treatment conditions: 230{sup o}C and impregnation with 1% w/w sulphuric acid concentration), assuming theoretical conversion of these sugars to ethanol. 29 refs., 2 figs., 5 tabs.

Aina mukana : mobiililaitteiden yleistymisen vaikutus verkkomainontaan

OpenAIRE

Rintala, Samu

2013-01-01

Tämän tutkielman tarkoituksena on selvittää, miten mobiililaitteiden yleistyminen vaikuttaa verkkomainontaan. Internet nousi valtamedioiden joukkoon viime vuosikymmenen aikana, koska kiinteähintaiset laajakaistat ja käyttäjien valta kasvattivat sen suosiota. Verkkomainonta mahdollisti uudenlaisen tiedon saamisen asiakkaista mittaamalla, mutta laajalle levinneeseen verkkoon oli luotava tarkka strategia, että potentiaaliset asiakkaat saatiin tavoitettua. Mobiililaitteet, jotka mahdollistavat in...

Fuel performance and operation experience of WWER-440 fuel in improved fuel cycle

International Nuclear Information System (INIS)

Gagarinski, A.; Proselkov, V.; Semchenkov, Yu.

2007-01-01

The paper summarizes WWER-440 second-generation fuel operation experience in improved fuel cycles using the example of Kola NPP units 3 and 4. Basic parameters of fuel assemblies, fuel rods and uranium-gadolinium fuel rods, as well as the principal neutronic parameters and burn-up achieved in fuel assemblies are presented. The paper also contains some data concerning the activity of coolant during operation (Authors)

Advanced fuel development at AECL: What does the future hold for CANDU fuels/fuel cycles?

Energy Technology Data Exchange (ETDEWEB)

Kupferschmidt, W.C.H. [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada)

2013-07-01

This paper outlines advanced fuel development at AECL. It discusses expanding the limits of fuel utilization, deploy alternate fuel cycles, increase fuel flexibility, employ recycled fuels; increase safety and reliability, decrease environmental impact and develop proliferation resistant fuel and fuel cycle.

HTGR fuel and fuel cycle technology

International Nuclear Information System (INIS)

Lotts, A.L.; Coobs, J.H.

1976-08-01

The status of fuel and fuel cycle technology for high-temperature gas-cooled reactors (HTGRs) is reviewed. The all-ceramic core of the HTGRs permits high temperatures compared with other reactors. Core outlet temperatures of 740 0 C are now available for the steam cycle. For advanced HTGRs such as are required for direct-cycle power generation and for high-temperature process heat, coolant temperatures as high as 1000 0 C may be expected. The paper discusses the variations of HTGR fuel designs that meet the performance requirements and the requirements of the isotopes to be used in the fuel cycle. Also discussed are the fuel cycle possibilities, which include the low-enrichment cycle, the Th- 233 U cycle, and plutonium utilization in either cycle. The status of fuel and fuel cycle development is summarized

The Third Dryout Fuel Behaviour Test Series in IFA-613

International Nuclear Information System (INIS)

Ianiri, Raffaella

1998-02-01

The objective of the dryout experiment with the instrumented fuel assembly IFA-613 is to provide information on the consequences induced on fuel by short terms dry outs having characteristics similar to those anticipated to occur from pump trips in a Boiling Water Reactor (BWR). For the third experiment it was planned to test one fresh and two pre-irradiated segments. Unfortunately one of the channels, Channel A developed a leakage and was not suitable for testing anymore. The rig was loaded with only two rods: one fresh PWR rod with a design similar to the fresh rod in IFA-613.1 and one pre-irradiated PWR segment (N1310 with a burn-up of 29 MWd/kgU). Both rods were equipped with a clad extensometer and two clad surface thermocouples (upper and lower position). The rig was loaded during the December 1997 shutdown and the dryout tests were performed on 16th January 1998. Both rods experienced temperature excursions with a target peak clad temperature (PCT) of 650 o C. According to the measured cladding temperatures, the time above the target temperature was about 4-5 s for both rods. The lower thermocouple did not indicate dryout at any occasion. The rig was unloaded immediately after the testing. (author)

Optimisation of dilute acid pre-treatment of artisan rice hulls for ethanol production

International Nuclear Information System (INIS)

Lopez, Yoney; Martin, Carlos; Gullon, Beatriz; Parajo, Juan Carlos

2011-01-01

Rice hulls are potential low-cost feedstocks for fuel ethanol production in many countries. In this work, the dilute-acid pre-treatment of artisan rice hulls was investigated using a central composite rotatable experimental design. The experimental variables were temperature (140-210 C), biomass load (5-20%) and sulphuric acid concentration (0.5-1.5 g per 100 g of reaction mixture). A total of 16 experimental runs, including a 23-plan, two replicates at the central point and six star points, were carried out. Low temperatures were found to be favourable for the hydrolysis of xylan and of the easily hydrolyzable glucan fraction. High glucose formation (up to 15.3 g/100 g), attributable to starch hydrolysis, was detected in the hydrolysates obtained under the least severe pre-treatment conditions. Using the experimental results, several models for predicting the effect of the operational conditions on the yield of pretreated solids, xylan and glucan conversion upon pre-treatment, and on enzymatic convertibility of cellulose were developed. Optimum results were predicted for the conversion of easily-hydrolyzable glucan in the material pretreated at 140.7 C, and for the enzymatic saccharification of cellulose in the material pretreated at 169 C. These results suggested the use of two-step acid hydrolysis as future pre-treatment strategy for artisan rice hulls. Key words: Dilute acid hydrolysis, enzymatic hydrolysis, pre-treatment, rice hulls. (author)

Pre-fire treatment effects and post-fire forest dynamics on the Rodeo-Chediski burn area, Arizona

Science.gov (United States)

Barbara A. Strom

2005-01-01

The 2002 Rodeo-Chediski fire was the largest wildfire in Arizona history at 189,000 ha (468,000 acres), and exhibited some of the most extreme fire behavior ever seen in the Southwest. Pre-fire fuel reduction treatments of thinning, timber harvesting, and prescribed burning on the White Mountain Apache Tribal lands (WMAT) and thinning on the Apache-Sitgreaves National...

76 FR 37703 - Regulation of Fuels and Fuel Additives: 2012 Renewable Fuel Standards; Public Hearing

Science.gov (United States)

2011-06-28

... Regulation of Fuels and Fuel Additives: 2012 Renewable Fuel Standards; Public Hearing AGENCY: Environmental... hearing to be held for the proposed rule ``Regulation of Fuels and Fuel Additives: 2012 Renewable Fuel... be proposing amendments to the renewable fuel standard program regulations to establish annual...

Microbial alkane production for jet fuel industry: motivation, state of the art and perspectives.

Science.gov (United States)

Jiménez-Díaz, Lorena; Caballero, Antonio; Pérez-Hernández, Natalia; Segura, Ana

2017-01-01

Bio-jet fuel has attracted a lot of interest in recent years and has become a focus for aircraft and engine manufacturers, oil companies, governments and researchers. Given the global concern about environmental issues and the instability of oil market, bio-jet fuel has been identified as a promising way to reduce the greenhouse gas emissions from the aviation industry, while also promoting energy security. Although a number of bio-jet fuel sources have been approved for manufacture, their commercialization and entry into the market is still a far way away. In this review, we provide an overview of the drivers for intensified research into bio-jet fuel technologies, the type of chemical compounds found in bio-jet fuel preparations and the current state of related pre-commercial technologies. The biosynthesis of hydrocarbons is one of the most promising approaches for bio-jet fuel production, and thus we provide a detailed analysis of recent advances in the microbial biosynthesis of hydrocarbons (with a focus on alkanes). Finally, we explore the latest developments and their implications for the future of research into bio-jet fuel technologies. © 2016 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

Multi-fuel reformers for fuel cells used in transportation. Phase 1: Multi-fuel reformers

Science.gov (United States)

1994-05-01

DOE has established the goal, through the Fuel Cells in Transportation Program, of fostering the rapid development and commercialization of fuel cells as economic competitors for the internal combustion engine. Central to this goal is a safe feasible means of supplying hydrogen of the required purity to the vehicular fuel cell system. Two basic strategies are being considered: (1) on-board fuel processing whereby alternative fuels such as methanol, ethanol or natural gas stored on the vehicle undergo reformation and subsequent processing to produce hydrogen, and (2) on-board storage of pure hydrogen provided by stationary fuel processing plants. This report analyzes fuel processor technologies, types of fuel and fuel cell options for on-board reformation. As the Phase 1 of a multi-phased program to develop a prototype multi-fuel reformer system for a fuel cell powered vehicle, the objective of this program was to evaluate the feasibility of a multi-fuel reformer concept and to select a reforming technology for further development in the Phase 2 program, with the ultimate goal of integration with a DOE-designated fuel cell and vehicle configuration. The basic reformer processes examined in this study included catalytic steam reforming (SR), non-catalytic partial oxidation (POX) and catalytic partial oxidation (also known as Autothermal Reforming, or ATR). Fuels under consideration in this study included methanol, ethanol, and natural gas. A systematic evaluation of reforming technologies, fuels, and transportation fuel cell applications was conducted for the purpose of selecting a suitable multi-fuel processor for further development and demonstration in a transportation application.

Air/fuel ratio visualization in a diesel spray

Science.gov (United States)

Carabell, Kevin David

1993-01-01

To investigate some features of high pressure diesel spray ignition, we have applied a newly developed planar imaging system to a spray in an engine-fed combustion bomb. The bomb is designed to give flow characteristics similar to those in a direct injection diesel engine yet provide nearly unlimited optical access. A high pressure electronic unit injector system with on-line manually adjustable main and pilot injection features was used. The primary scalar of interest was the local air/fuel ratio, particularly near the spray plumes. To make this measurement quantitative, we have developed a calibration LIF technique. The development of this technique is the key contribution of this dissertation. The air/fuel ratio measurement was made using biacetyl as a seed in the air inlet to the engine. When probed by a tripled Nd:YAG laser the biacetyl fluoresces, with a signal proportional to the local biacetyl concentration. This feature of biacetyl enables the fluorescent signal to be used as as indicator of local fuel vapor concentration. The biacetyl partial pressure was carefully controlled, enabling estimates of the local concentration of air and the approximate local stoichiometry in the fuel spray. The results indicate that the image quality generated with this method is sufficient for generating air/fuel ratio contours. The processes during the ignition delay have a marked effect on ignition and the subsequent burn. These processes, vaporization and pre-flame kinetics, very much depend on the mixing of the air and fuel. This study has shown that poor mixing and over-mixing of the air and fuel will directly affect the type of ignition. An optimal mixing arrangement exists and depends on the swirl ratio in the engine, the number of holes in the fuel injector and the distribution of fuel into a pilot and main injection. If a short delay and a diffusion burn is desired, the best mixing parameters among those surveyed would be a high swirl ratio, a 4-hole nozzle and a

Fuel assembly

International Nuclear Information System (INIS)

Chaki, Masao; Nishida, Koji; Karasawa, Hidetoshi; Kanazawa, Toru; Orii, Akihito; Nagayoshi, Takuji; Kashiwai, Shin-ichi; Masuhara, Yasuhiro

1998-01-01

The present invention concerns a fuel assembly, for a BWR type nuclear reactor, comprising fuel rods in 9 x 9 matrix. The inner width of the channel box is about 132mm and the length of the fuel rods which are not short fuel rods is about 4m. Two water rods having a circular cross section are arranged on a diagonal line in a portion of 3 x 3 matrix at the center of the fuel assembly, and two fuel rods are disposed at vacant spaces, and the number of fuel rods is 74. Eight fuel rods are determined as short fuel rods among 74 fuel rods. Assuming the fuel inventory in the short fuel rod as X(kg), and the fuel inventory in the fuel rods other than the short fuel rods as Y(kg), X and Y satisfy the relation: X + Y ≥ 173m, Y ≤ - 9.7X + 292, Y ≤ - 0.3X + 203 and X > 0. Then, even when the short fuel rods are used, the fuel inventory is increased and fuel economy can be improved. (I.N.)

Fuel assemblies

International Nuclear Information System (INIS)

Mukai, Hideyuki

1987-01-01

Purpose: To prevent bending of fuel rods caused by the difference of irradiation growth between coupling fuel rods and standards fuel rods thereby maintain the fuel rod integrity. Constitution: The f value for a fuel can (the ratio of pole of zirconium crystals in the entire crystals along the axial direction of the fuel can) of a coupling fuel rod secured by upper and lower tie plates is made smaller than the f value for the fuel can of a standard fuel rod not secured by the upper and the lower tie plates. This can make the irradiation growth of the fuel can of the coupling fuel rod greater than the irradiation growth of the fuel can of the standard fuel rod and, accordingly, since the elongation of the standard fuel rod can always by made greater, bending of the standard fuel rod can be prevented. (Yoshihara, M.)

Features of fuel performance at high fuel burnups

International Nuclear Information System (INIS)

Proselkov, V.N.; Scheglov, A.S.; Smirnov, A.V.; Smirnov, V.P.

2001-01-01

Some features of fuel behavior at high fuel burnups, in particular, initiation and development of rim-layer, increase in the rate of fission gas release from the fuel and increase in the inner gas pressure in the fuel rod are briefly described. Basing on the analysis of the data of post-irradiation examinations of fuel rods of WWER-440 working FA and CR fuel followers, that have been operated for five fuel cycles and got the average fuel burnup or varies as 50MW-day/kgU, a conclusion is made that the WWER-440 fuel burnup can be increased at least to average burnups of 55-58 MW-day/kgU per fuel assembly (Authors)

Technical concept for test of geologic storage of spent reactor fuel in the Climax granite, Nevada Test Site

International Nuclear Information System (INIS)

Ramspott, L.D.; Ballou, L.B.; Carlson, R.C.; Montan, D.N.; Butkovich, T.R.; Duncan, J.E.; Patrick, W.C.; Wilder, D.G.; Brough, W.G.; Mayr, M.C.

1979-01-01

The Spent Fuel Test in the Climax granite at the Nevada Test Site is a generic test in which spent fuel assemblies from an operating commercial nuclear reactor are emplaced at, and retrieved from, a plausible waste repository depth in a typical granite. Eleven canisters of spent fuel are emplaced in a storage drift 420 m below the surface along with six electrical simulator canisters. Two adjacent drifts contain electrical heaters which are operated so as to simulate the initial five years of the temperature-stress-displacement fields of a large repository. The site is described, and the pre-operational measurement program and characteristics of the spent fuel are given. Both thermal and mechanical response calculations are summarized. The field instrumentation and data acquisition systems are described, as well as the system for handling the spent fuel

DK-SOFCa. Development of solid oxide fuel cells. Technical final report; DK-SOFCa, udvikling af fastoxid braendselsceller. Teknisk slutrapport

Energy Technology Data Exchange (ETDEWEB)

Larsen, P.H.

2004-08-01

This project is part of the Danish strategy for solid oxide fuel cells. The main purpose with the project was to upgrade Danish fuel cell technology within the SOFC area from established laboratory production techniques to pre-pilot scale. This target has been reached, as a 400m{sup 2} production area with equipment capable of producing up to 500 homogeneous, batch-size cells with a low rejection rate has been established. The production processes are described, analysed and optimised systematically in order to create a basis for a future upgrading to industrial production. A number of non-destructive evaluation methods have been developed for quality control of the produced cells. A reproducibility study of the established production process has contributed to identifying reasons for variations in the yield of the cells, and has enabled a continuous quality improvement. The cells produced on the pre-pilot plant are globally competitive as to mechanical strength, service life and electrical yield. Thus, the project has opened an opportunity for a demonstration of Danish fuel cell technology. (BA)

BioTfueL Project: Targeting the Development of Second-Generation Bio-diesel and Bio-jet Fuels

International Nuclear Information System (INIS)

Viguie, J.C.; Ullrich, N.; Porot, P.; Bournay, L.; Hecquet, M.; Rousseau, J.

2013-01-01

2. generation biofuels will have an important part to take in the energy transition as far as fuels are concerned. Using non edible biomass, they will avoid any direct competition with food usage. Within second generation biofuels, the BTL route consists in the production of middle distillates (Diesel and jet fuel) via gasification and Fischer-Tropsch (FT) synthesis. These fuels are called 'drop in' fuels; this means that to be used they technically do not request any modification in the vehicle whatever the blending rate with conventional fuels. This route is currently at the pre-industrial phase where demonstration is required. This article presents the BioTfueL project which has been created by Axens, CEA, IFP Energies Nouvelles, Sofiproteol, ThyssenKrupp Uhde and Total. This project is focused on the original concept of co-processing (biomass can be gasified together with fossil feedstock) and proposes to develop and demonstrate a full process chain to be commercialized worldwide via licensing. (authors)

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)

Alternative fuel produced from thermal pyrolysis of waste tires and its use in a DI diesel engine

International Nuclear Information System (INIS)

Wang, Wei-Cheng; Bai, Chi-Jeng; Lin, Chi-Tung; Prakash, Samay

2016-01-01

Highlights: • The liquid, solid and gas yields from pyrolysis of waste tires were investigated. • For energy and economic consideration, pre-treatments of TPO were avoided. • Various proportions of TPO-diesel mixture were tested in a DI diesel engine. • TPOs derived from various pyrolysis temperatures were also tested in engine. • Fuel consumption, cylinder pressure, engine power, and SO2 emission were discussed. - Abstract: Alternative fuels from waste material have been receiving attentions due to the increasing demand of fossil fuels. Pyrolysis has been a considerable solution for processing waste tires because it gives clean emissions and produces valuable liquid or solid products. Pyrolysis oil from waste tires has become a potential replacement for petroleum diesel due to the similar physical and chemical properties to diesel fuel. In this study, waste tires were pyrolyzed in a lab-scale fixed bed reactor with various reaction temperatures. The liquid, solid and gas product yields from different pyrolysis temperatures were compared, as well as the analyses of property and element for the oil product. Due to the energy and economic consideration, the pre-treatments of TPO before adding into regular diesel were avoided. The TPO derived from various pyrolysis temperatures were mixed with regular diesel at different proportions and subsequently tested in a DI diesel engine. The engine performance, such as fuel consumption, cylinder pressure, engine power, and SO_2 emission, were examined and discussed. The results indicated that increasing the TPO fraction in diesel lead to worse engine performance, but it can be recovered using TPOs produced from higher pyrolysis temperatures.

Benefits of barrier fuel on fuel cycle economics

International Nuclear Information System (INIS)

Crowther, R.L.; Kunz, C.L.

1988-01-01

Barrier fuel rod cladding was developed to eliminate fuel rod failures from pellet/cladding stress/corrosion interaction and to eliminate the associated need to restrict the rate at which fuel rod power can be increased. The performance of barrier cladding has been demonstrated through extensive testing and through production application to many boiling water reactors (BWRs). Power reactor data have shown that barrier fuel rod cladding has a significant beneficial effect on plant capacity factor and plant operating costs and significantly increases fuel reliability. Independent of the fuel reliability benefit, it is less obvious that barrier fuel has a beneficial effect of fuel cycle costs, since barrier cladding is more costly to fabricate. Evaluations, measurements, and development activities, however, have shown that the fuel cycle cost benefits of barrier fuel are large. This paper is a summary of development activities that have shown that application of barrier fuel significantly reduces BWR fuel cycle costs

Design and analysis of CANDU advanced fuel -Development of the advanced CANDU technology-

International Nuclear Information System (INIS)

Seok, Ho Cheon; Shim, Ki Seop; Byeon, Taek Sang; Park, Kwang Seok; Kim, Bong Ki; Lee, Yeong Uk; Jeong, Chang Joon; Oh, Deok Joo; Lee, Ui Joo; Park, Joo Hwan; Lee, Sang Yong; Jeong, Beop Dong; Choi, Han Rim; Lee, Yeong Jin; Choi, Cheol Jin; Choi, Jong Ho; Lee, Kwang Won; Cho, Cheon Hyi; On, Myeong Ryong; Kim, Taek Mo; Lim, Hong Sik; Lee, Kang Moon; Lee, Nam Ho; Lee, Kyu Hyeong

1994-07-01

It has been projected that a total of 5 pressurized heavy water reactors (PHWR) including Wolsong 1 under operation and Wolsong 2, 3 and 4 under construction will be operated by 2006, and so about 500 ton of natural uranium will be consumed every year and a lot of spent fuels will be generated. Therefore, the ultimate goal of this R and D project is to develop the CANDU advanced fuel having the following capabilities compared with existing standard fuel: (1) To reduce linear heat generation rating by more than 15% (i.e., less than 50 kW/m), (2) To extend fuel burnup by more than 3 times (i.e., higher than 21,000 MWD/MTU), and (3) To increase critical channel power by more than 5%. In accordance, the followings are performed in this fiscal year: (1) Undertake CANFLEX-NU design and thermalmechanical performance analysis, and prepare design documents, (2) Establish reactor physics analysis code system, and investigate the compativility of the CANFLEX-NU fuel with the standard 37-element fuel in the CANDU-6 reactor. (3) Establish safety analysis methodology with the assumption of the CANFLEX-NU loaded CANDU-6 reactor, and perform the preliminary thermalhydraulic and fuel behavior for the selected DBA accidents, (4) Investigate reactor physics analysis code system as pre-study for CANFLEX-SEU loaded reactors

Irradiation tests on PHWR type fuel elements in TRIGA research reactor of INR Pitesti

Energy Technology Data Exchange (ETDEWEB)

Horhoianu, Grigore [Institute for Nuclear Research, Pitesti (Romania). Nuclear Fuel Engineering Lab.; Sorescu, Ion [Institute for Nuclear Research, Pitesti (Romania). TRIGA Reactor Loop Facility; Parvan, Marcel [Institute for Nuclear Research, Pitesti (Romania). Hot Cells Lab.

2012-12-15

Nine PHWR type fuel elements with reduced length were irradiated in loop A of the TRIGA Research Reactor of INR Pitesti. The primary objective of the test was to determine the performance of nuclear fuel fabricated at INR Pitesti at high linear powers in pressurized water conditions. Six fuel elements were irradiated with a ramp power history, achieving a maximum power of 45 kW/m during pre-ramp and of 64 kW/m in the ramp. The maximum discharge burnup was of 216 MWh/kgU. Another three fuel elements with reduced length were irradiated with declining power history. At the beginning of irradiation the fuel elements achieved a maximum linear power of 66 kW/m. The maximum fuel power was about 1.3 times the maximum expected in PHWR. The maximum discharge burnup was 205 MWh/kgU. The elements were destructively examined in the hot cells of INR Pitesti. Temperature-sensitive parameters such as UO{sub 2} grain growth, fission-gas release and sheath deformations were examined. The tests proved the feasibility of irradiating PHWR type fuel elements at linear powers up to 66 kW/m under pressurized water conditions and demonstrated the possibility of more flexible operation of this fuel in power reactors. This paper presents the results of the investigation. (orig.)

Fuel assembly

International Nuclear Information System (INIS)

Yamazaki, Hajime.

1995-01-01

In a fuel assembly having fuel rods of different length, fuel pellets of mixed oxides of uranium and plutonium are loaded to a short fuel rod. The volume ratio of a pellet-loaded portion to a plenum portion of the short fuel rod is made greater than the volume ratio of a fuel rod to which uranium fuel pellets are loaded. In addition, the volume of the plenum portion of the short fuel rod is set greater depending on the plutonium content in the loaded fuel pellets. MOX fuel pellets are loaded on the short fuel rods having a greater degree of freedom relevant to the setting for the volume of the plenum portion compared with that of a long rod fuel, and the volume of the plenum portion is ensured greater depending on the plutonium content. Even if a large amount of FP gas and He gas are discharged from the MOX fuels compared with that from the uranium fuels, the internal pressure of the MOX fuel rod during operation is maintained substantially identical with that of the uranium fuel rod, so that a risk of generating excess stresses applied to the fuel cladding tubes and rupture of fuels are greatly reduced. (N.H.)

Framing car fuel efficiency : linearity heuristic for fuel consumption and fuel-efficiency ratings

NARCIS (Netherlands)

Schouten, T.M.; Bolderdijk, J.W.; Steg, L.

2014-01-01

People are sensitive to the way information on fuel efficiency is conveyed. When the fuel efficiency of cars is framed in terms of fuel per distance (FPD; e.g. l/100 km), instead of distance per units of fuel (DPF; e.g. km/l), people have a more accurate perception of potential fuel savings. People

Used fuel packing plant for CANDU fuel

Energy Technology Data Exchange (ETDEWEB)

Menzies, I.; Thayer, B.; Bains, N., E-mail: imenzies@atsautomation.com [ATS Automation, Cambridge, ON (Canada); Murchison, A., E-mail: amurchison@nwmo.ca [NWMO, Toronto, ON (Canada)

2015-07-01

Large forgings have been selected to containerize Light Water Reactor used nuclear fuel. CANDU fuel, which is significantly smaller in size, allows novel approaches for containerization. For example, by utilizing commercially available extruded ASME pipe a conceptual design of a Used Fuel Packing Plant for containerization of used CANDU fuel in a long lived metallic container has been developed. The design adopts a modular approach with multiple independent work cells to transfer and containerize the used fuel. Based on current technologies and concepts from proven industrial systems, the Used Fuel Packing Plant can assemble twelve used fuel containers per day considering conservative levels of process availability. (author)

Axisymmetric whole pin life modelling of advanced gas-cooled reactor nuclear fuel

International Nuclear Information System (INIS)

Mella, R.; Wenman, M.R.

2013-01-01

Thermo-mechanical contributions to pellet–clad interaction (PCI) in advanced gas-cooled reactors (AGRs) are modelled in the ABAQUS finite element (FE) code. User supplied sub-routines permit the modelling of the non-linear behaviour of AGR fuel through life. Through utilisation of ABAQUS’s well-developed pre- and post-processing ability, the behaviour of the axially constrained steel clad fuel was modelled. The 2D axisymmetric model includes thermo-mechanical behaviour of the fuel with time and condition dependent material properties. Pellet cladding gap dynamics and thermal behaviour are also modelled. The model treats heat up as a fully coupled temperature-displacement study. Dwell time and direct power cycling was applied to model the impact of online refuelling, a key feature of the AGR. The model includes the visco-plastic behaviour of the fuel under the stress and irradiation conditions within an AGR core and a non-linear heat transfer model. A multiscale fission gas release model is applied to compute pin pressure; this model is coupled to the PCI gap model through an explicit fission gas inventory code. Whole pin, whole life, models are able to show the impact of the fuel on all segments of cladding including weld end caps and cladding pellet locking mechanisms (unique to AGR fuel). The development of this model in a commercial FE package shows that the development of a potentially verified and future-proof fuel performance code can be created and used

A study of the friction and wear processes of the structural components of fuel assemblies for water-cooled and water moderated power reactors

International Nuclear Information System (INIS)

Makarov, V.; Afanasiev, A.; Matvienko, I.; Drozdov, Y.; Puchkov, V.

2011-01-01

The friction forces affect the fuel assembly (FA) strength at all the stages of its lifecycle. The paper covers the methods and the results of the pre-irradiation experimental studies of the static and dynamic processes the friction forces are involved in. These comprise the FA assembling at the manufacturer, fuel rod flow-induced vibration and fretting-wear in the fuel rod-to-cell friction pairs, rod cluster control assembly (RCCA) movement in the FA guide tubes, FA bowing, FA loading-unloading into the core, irradiation-induced growth and thermal-mechanical fuel rod-to-spacer grid interaction. (authors)

Fuel assembly

International Nuclear Information System (INIS)

Sakuyama, Tadashi; Mukai, Hideyuki.

1988-01-01

Purpose: To prevent the bending of a fuel rod caused by the difference in the elongation between a joined fuel rod and a standard fuel rod thereby maintain the fuel rod integrity. Constitution: A joined fuel rod is in a thread engagement at its lower end plug thereof with a lower plate, while passed through at its upper end plug into an upper tie plate and secured with a nut. Further, a standard fuel rod is engaged at its upper end plug and lower end plug with the upper tie plate and the lower tie plate respectively. Expansion springs are mounted to the upper end plugs of these bonded fuel rods and the standard fuel rods for preventing this lifting. Each of the fuel rods comprises a plurality of sintered pellets of nuclear fuel materials laminated in a zircaloy fuel can. The content of the alloy ingredient in the fuel can of the bonded fuel rod is made greater than that of the alloy ingredient of the standard fuel rod. this can increase the elongation for the bonded fuel rod, and the spring of the standard fuel rod is tightly bonded to prevent the bending. (Yoshino, Y.)

Fuel performance of DOE fuels in water storage

International Nuclear Information System (INIS)

Hoskins, A.P.; Scott, J.G.; Shelton-Davis, C.V.; McDannel, G.E.

1993-01-01

Westinghouse Idaho Nuclear Company operates the Idaho Chemical Processing Plant (ICPP) at the Idaho National Engineering Laboratory. In April of 1992, the U.S. Department of Energy (DOE) decided to end the fuel reprocessing mission at ICPP. Fuel performance in storage received increased emphasis as the fuel now needs to be stored until final dispositioning is defined and implemented. Fuels are stored in four main areas: an original underwater storage facility, a modern underwater storage facility, and two dry fuel storage facilities. As a result of the reactor research mission of the DOE and predecessor agencies, the Energy Research and Development Administration and the Atomic Energy Commission, many types of nuclear fuel have been developed, used, and assigned to storage at the ICPP. Fuel clad with stainless steel, zirconium, aluminum, and graphite are represented. Fuel matrices include uranium oxide, hydride, carbide, metal, and alloy fuels, resulting in 55 different fuel types in storage. Also included in the fuel storage inventory is canned scrap material

Fuel Supply Defaults for Regional Fuels and Fuel Wizard Tool in MOVES201X

Science.gov (United States)

The fuel supply report documents the data and methodology used to derive the default gasoline, diesel and fuel-blend fuel properties, and their respective fuel market share in MOVES. The default market share of the individual fuels varies by calendar year, seasons, and several do...

78 FR 12005 - Regulation of Fuels and Fuel Additives: 2013 Renewable Fuel Standards; Public Hearing

Science.gov (United States)

2013-02-21

... Regulation of Fuels and Fuel Additives: 2013 Renewable Fuel Standards; Public Hearing AGENCY: Environmental... EPA is announcing a public hearing to be held for the proposed rule ``Regulation of Fuels and Fuel Additives: 2013 Renewable Fuel Standards,'' which was published separately in the Federal Register on...

Solid TRU fuels and fuel cycle technology

International Nuclear Information System (INIS)

Ogawa, Toru; Suzuki, Yasufumi

1997-01-01

Alloys and nitrides are candidate solid fuels for transmutation. However, the nitride fuels are preferred to the alloys because they have more favorable thermal properties which allows to apply a cold-fuel concept. The nitride fuel cycle technology is briefly presented

Nuclear fuels

International Nuclear Information System (INIS)

Beauvy, M.; Berthoud, G.; Defranceschi, M.; Ducros, G.; Guerin, Y.; Limoge, Y.; Madic, Ch.; Santarini, G.; Seiler, J.M.; Sollogoub, P.; Vernaz, E.; Guillet, J.L.; Ballagny, A.; Bechade, J.L.; Bonin, B.; Brachet, J.Ch.; Delpech, M.; Dubois, S.; Ferry, C.; Freyss, M.; Gilbon, D.; Grouiller, J.P.; Iracane, D.; Lansiart, S.; Lemoine, P.; Lenain, R.; Marsault, Ph.; Michel, B.; Noirot, J.; Parrat, D.; Pelletier, M.; Perrais, Ch.; Phelip, M.; Pillon, S.; Poinssot, Ch.; Vallory, J.; Valot, C.; Pradel, Ph.; Bonin, B.; Bouquin, B.; Dozol, M.; Lecomte, M.; Vallee, A.; Bazile, F.; Parisot, J.F.; Finot, P.; Roberts, J.F.

2009-01-01

Fuel is one of the essential components in a reactor. It is within that fuel that nuclear reactions take place, i.e. fission of heavy atoms, uranium and plutonium. Fuel is at the core of the reactor, but equally at the core of the nuclear system as a whole. Fuel design and properties influence reactor behavior, performance, and safety. Even though it only accounts for a small part of the cost per kilowatt-hour of power provided by current nuclear power plants, good utilization of fuel is a major economic issue. Major advances have yet to be achieved, to ensure longer in-reactor dwell-time, thus enabling fuel to yield more energy; and improve ruggedness. Aside from economics, and safety, such strategic issues as use of plutonium, conservation of resources, and nuclear waste management have to be addressed, and true technological challenges arise. This Monograph surveys current knowledge regarding in-reactor behavior, operating limits, and avenues for R and D. It also provides illustrations of ongoing research work, setting out a few noteworthy results recently achieved. Content: 1 - Introduction; 2 - Water reactor fuel: What are the features of water reactor fuel? 9 (What is the purpose of a nuclear fuel?, Ceramic fuel, Fuel rods, PWR fuel assemblies, BWR fuel assemblies); Fabrication of water reactor fuels (Fabrication of UO 2 pellets, Fabrication of MOX (mixed uranium-plutonium oxide) pellets, Fabrication of claddings); In-reactor behavior of UO 2 and MOX fuels (Irradiation conditions during nominal operation, Heat generation, and removal, The processes involved at the start of irradiation, Fission gas behavior, Microstructural changes); Water reactor fuel behavior in loss of tightness conditions (Cladding, the first containment barrier, Causes of failure, Consequences of a failure); Microscopic morphology of fuel ceramic and its evolution under irradiation; Migration and localization of fission products in UOX and MOX matrices (The ceramic under irradiation

Nuclear fuels

Energy Technology Data Exchange (ETDEWEB)

Beauvy, M.; Berthoud, G.; Defranceschi, M.; Ducros, G.; Guerin, Y.; Limoge, Y.; Madic, Ch.; Santarini, G.; Seiler, J.M.; Sollogoub, P.; Vernaz, E.; Guillet, J.L.; Ballagny, A.; Bechade, J.L.; Bonin, B.; Brachet, J.Ch.; Delpech, M.; Dubois, S.; Ferry, C.; Freyss, M.; Gilbon, D.; Grouiller, J.P.; Iracane, D.; Lansiart, S.; Lemoine, P.; Lenain, R.; Marsault, Ph.; Michel, B.; Noirot, J.; Parrat, D.; Pelletier, M.; Perrais, Ch.; Phelip, M.; Pillon, S.; Poinssot, Ch.; Vallory, J.; Valot, C.; Pradel, Ph.; Bonin, B.; Bouquin, B.; Dozol, M.; Lecomte, M.; Vallee, A.; Bazile, F.; Parisot, J.F.; Finot, P.; Roberts, J.F

2009-07-01

Fuel is one of the essential components in a reactor. It is within that fuel that nuclear reactions take place, i.e. fission of heavy atoms, uranium and plutonium. Fuel is at the core of the reactor, but equally at the core of the nuclear system as a whole. Fuel design and properties influence reactor behavior, performance, and safety. Even though it only accounts for a small part of the cost per kilowatt-hour of power provided by current nuclear power plants, good utilization of fuel is a major economic issue. Major advances have yet to be achieved, to ensure longer in-reactor dwell-time, thus enabling fuel to yield more energy; and improve ruggedness. Aside from economics, and safety, such strategic issues as use of plutonium, conservation of resources, and nuclear waste management have to be addressed, and true technological challenges arise. This Monograph surveys current knowledge regarding in-reactor behavior, operating limits, and avenues for R and D. It also provides illustrations of ongoing research work, setting out a few noteworthy results recently achieved. Content: 1 - Introduction; 2 - Water reactor fuel: What are the features of water reactor fuel? 9 (What is the purpose of a nuclear fuel?, Ceramic fuel, Fuel rods, PWR fuel assemblies, BWR fuel assemblies); Fabrication of water reactor fuels (Fabrication of UO{sub 2} pellets, Fabrication of MOX (mixed uranium-plutonium oxide) pellets, Fabrication of claddings); In-reactor behavior of UO{sub 2} and MOX fuels (Irradiation conditions during nominal operation, Heat generation, and removal, The processes involved at the start of irradiation, Fission gas behavior, Microstructural changes); Water reactor fuel behavior in loss of tightness conditions (Cladding, the first containment barrier, Causes of failure, Consequences of a failure); Microscopic morphology of fuel ceramic and its evolution under irradiation; Migration and localization of fission products in UOX and MOX matrices (The ceramic under

Fuel economy of hybrid fuel-cell vehicles

Science.gov (United States)

Ahluwalia, Rajesh K.; Wang, X.; Rousseau, A.

The potential improvement in fuel economy of a mid-size fuel-cell vehicle by combining it with an energy storage system has been assessed. An energy management strategy is developed and used to operate the direct hydrogen, pressurized fuel-cell system in a load-following mode and the energy storage system in a charge-sustaining mode. The strategy places highest priority on maintaining the energy storage system in a state where it can supply unanticipated boost power when the fuel-cell system alone cannot meet the power demand. It is found that downsizing a fuel-cell system decreases its efficiency on a drive cycle which is compensated by partial regenerative capture of braking energy. On a highway cycle with limited braking energy the increase in fuel economy with hybridization is small but on the stop-and-go urban cycle the fuel economy can improve by 27%. On the combined highway and urban drive cycles the fuel economy of the fuel-cell vehicle is estimated to increase by up to 15% by hybridizing it with an energy storage system.

Rethinking the economics of centralized spent fuel storage

International Nuclear Information System (INIS)

Wood, T.W.; Short, S.M.; Dippold, D.G.; Rod, S.R.; Williams, J.W.

1991-04-01

The technology for extended storage of spent nuclear fuel (SNF), either at-reactor or in a centralized facility such as a monitored retrievable storage (MRS) facility, is well-developed and proven from an engineering and safety perspective. The question of whether spent fuel should await its final geologic disposal while at a reactor site or in an MRS facility is essentially an economic one. While intuition and previous results suggest that centralized storage will be more economical than at-reactor storage beyond some break-even quantity of SNF, the incremental costs of pool storage at-reactor are close to zero as long as pool capacity is generally available. Thus, if economics is the prime motivator, the quantity of spent fuel required to warrant centralized storage could be quite large. The economics of centralizing the storage of spent fuel at a single site, as opposed to continued storage at over 100 reactor sites, has been the subject of several recent analyses. Most of these analyses involved calculating the benefits of an MRS facility with a pre-defined MRS operating scenario. This paper reverses this approach to economic analysis of the MRS by seeking the optimal MRS operating scenario (in terms of the parameters listed above) implied by the economic incentives arising from the relative costs of at-reactor storage and centralized storage. This approach treats an MRS as a possible storage location that will be used according to its economic value in system operation. 5 refs., 5 figs

Ammonia as a Suitable Fuel for Fuel Cells

International Nuclear Information System (INIS)

Lan, Rong; Tao, Shanwen

2014-01-01

Ammonia, an important basic chemical, is produced at a scale of 150 million tons per year. Half of hydrogen produced in chemical industry is used for ammonia production. Ammonia containing 17.5 wt% hydrogen is an ideal carbon-free fuel for fuel cells. Compared to hydrogen, ammonia has many advantages. In this mini-review, the suitability of ammonia as fuel for fuel cells, the development of different types of fuel cells using ammonia as the fuel and the potential applications of ammonia fuel cells are briefly reviewed.

The evolving image and role of the regulator for implementing repositories for nuclear waste and spent nuclear fuel

International Nuclear Information System (INIS)

Melin, J.

2005-01-01

A country introducing nuclear power in their energy strategy has a life long obligation. The obligation is not mainly a question of energy production. It is an obligation to maintain safety during the phase of construction, energy production and decommissioning as well as to take care of all the waste streams from nuclear installations. I believe that one of the most controversial siting projects in the society is a waste repository for spent nuclear fuel. Competence, available funds and a clear responsibility between the stakeholders as well as the trust of the public is indispensable to obtain a good result. The Swedish programme for managing nuclear waste and spent nuclear fuel has been in progress for more than 25 years. The pre-licensing process of a repository for spent nuclear fuel is much alike a pre-licensing process for the first nuclear power plant in a country. You need a clear political will, you have to involve the nuclear regulator without jeopardizing his integrity and you need the money to perform research and make the investments. The enthusiasm of politicians and industry may however differ between these two projects. (author)

Ammonia as a suitable fuel for fuel cells

Directory of Open Access Journals (Sweden)

Rong eLan

2014-08-01

Full Text Available Ammonia, an important basic chemical, is produced at a scale of 150 million tons per year. Half of hydrogen produced in chemical industry is used for ammonia production. Ammonia containing 17.5wt% hydrogen is an ideal carbon-free fuel for fuel cells. Compared to hydrogen, ammonia has many advantages. In this mini-review, the suitability of ammonia as fuel for fuel cells, the development of different types of fuel cells using ammonia as the fuel and the potential applications of ammonia fuel cells are briefly reviewed.

Safety analysis of MOX fuels by fuel performance code

Energy Technology Data Exchange (ETDEWEB)

Suzuki, Motoe [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

2002-12-01

Performance of plutonium rick mixed oxide fuels specified for the Reduced-Moderation Water Reactor (RMWR) has been analysed by modified fuel performance code. Thermodynamic properties of these fuels up to 120 GWd/t burnup have not been measured and estimated using existing uranium fuel models. Fission product release, pressure rise inside fuel rods and mechanical loads of fuel cans due to internal pressure have been preliminarily assessed based on assumed axial power distribution history, which show the integrity of fuel performance. Detailed evaluation of fuel-cladding interactions due to thermal expansion or swelling of fuel pellets due to high burnup will be required for safety analysis of mixed oxide fuels. Thermal conductivity and swelling of plutonium rich mixed oxide fuels shall be taken into consideration. (T. Tanaka)

Comparative Analysis of Torque and Acceleration of Pre- and Post-Transmission Parallel Hybrid Drivetrains

Directory of Open Access Journals (Sweden)

Zulkifli Saiful A.

2016-01-01

Full Text Available Parallel hybrid electric vehicles (HEV can be classified according to the location of the electric motor with respect to the transmission unit for the internal combustion engine (ICE: they can be pre-transmission or posttransmission parallel hybrid. A split-axle parallel HEV – in which the ICE and electric motor provide propulsion power to different axles – is a sub-type of the post-transmission hybrid, since addition of torque and power from the two power sources occurs after the vehicle’s transmission. The term ‘through-the-road’ (TTR hybrid is also used for the split-parallel HEV, since power coupling between the ICE and electric motor is not through some mechanical device but through the vehicle itself, its wheels and the road on which it moves. The present work presents torquespeed relationship of the split-parallel hybrid and analyses simulation results of torque profiles and acceleration performance of pre-transmission and post-transmission hybrid configurations, using three different sizes of electric motor. Different operating regions of the pre-trans and post-trans motors are observed, leading to different speed and torque profiles. Although ICE average efficiency in the post-trans hybrid is slightly lower than in the pre-trans hybrid, the post-trans hybrid vehicle has better fuel economy and acceleration performance than the pre-trans hybrid vehicle.

Reactor fuel element and fuel assembly

International Nuclear Information System (INIS)

Okada, Seiji; Ishida, Tsuyoshi; Ikeda, Atsuko.

1997-01-01

A mixture of fission products and burnable poisons is disposed at least to a portion between MOX pellets to form a burnable poison-incorporated fuel element without mixing burnable poisons to the MOX pellets. Alternatively, a mixture of materials other than the fission products and burnable poisons is formed into disks, a fuel lamination portion is divided into at least to two regions, and the ratio of number of the disks of the mixture relative to the volume of the region is increased toward the lower portion of the fuel lamination portion. With such a constitution, the axial power distribution of fuels can be made flat easily. Alternatively, the thickness of the disk of the mixture is increased toward the lower region of the fuel lamination portion to flatten the axial power distribution of the fuels in the same manner easily. The time and the cost required for the manufacture are reduced, and MOX fuels filled with burnable poisons with easy maintenance and control can be realized. (N.H.)

Emergency fuels utilization guidebook. Alternative Fuels Utilization Program

Energy Technology Data Exchange (ETDEWEB)

1980-08-01

The basic concept of an emergency fuel is to safely and effectively use blends of specification fuels and hydrocarbon liquids which are free in the sense that they have been commandeered or volunteered from lower priority uses to provide critical transportation services for short-duration emergencies on the order of weeks, or perhaps months. A wide variety of liquid hydrocarbons not normally used as fuels for internal combustion engines have been categorized generically, including limited information on physical characteristics and chemical composition which might prove useful and instructive to fleet operators. Fuels covered are: gasoline and diesel fuel; alcohols; solvents; jet fuels; kerosene; heating oils; residual fuels; crude oils; vegetable oils; gaseous fuels.

PRE-DIABETES

OpenAIRE

Akula Annapurna

2013-01-01

Pre-diabetes is a condition where the body's cells begin to show resistance to insulin. Glucose circulates in the blood instead of being used by the cells for energy. Blood sugar levels become elevated. Increased weight, unhealthy diet and a sedentary lifestyle can lead to pre-diabetes. WHAT IS PRE-DIABETES A diagnosis of pre-diabetes means that the cells in your body are becoming resistant to insulin and your blood glucose levels are higher than they should be. Since the levels aren't as hig...

Dimpled/grooved face on a fuel injection nozzle body for flame stabilization and related method

Science.gov (United States)

Uhm, Jong Ho; Johnson, Thomas Edward; Kim, Kwanwoo; Zuo, Baifang

2013-08-20

A fuel injection head for a fuel nozzle used in a gas turbine combustor includes a substantially hollow body formed with an upstream end face, a downstream end face and a peripheral wall extending therebetween. A plurality of pre-mix tubes or passages extend axially through the hollow body with inlets at the upstream end face and outlets at the downstream end face. An exterior surface of the downstream end face is formed with three-dimensional surface features that increase a total surface area of the exterior surface as compared to a substantially flat, planar downstream end face.

Alternatives for implementing burnup credit in the design and operation of spent fuel transport casks

International Nuclear Information System (INIS)

Sanders, T.L.; Lake, W.H.

1989-01-01

It is possible to develop an optimal strategy for implementing burnup credit in spent fuel transport casks. For transport, the relative risk is rapidly reduced if additional pre-transport controls such as a cavity dryness verifications are conducted prior to transport. Some other operational and design features that could be incorporated into a burnup credit cask strategy are listed. These examples represent many of the system features and alternatives already available for use in developing a broadly based criticality safety strategy for implementing burnup credit in the design and operation of spent fuel transport casks. 4 refs., 1 tab

Estimation of Pre-industrial Nitrous Oxide Emission from the Terrestrial Biosphere

Science.gov (United States)

Xu, R.; Tian, H.; Lu, C.; Zhang, B.; Pan, S.; Yang, J.

2015-12-01

Nitrous oxide (N2O) is currently the third most important greenhouse gases (GHG) after methane (CH4) and carbon dioxide (CO2). Global N2O emission increased substantially primarily due to reactive nitrogen (N) enrichment through fossil fuel combustion, fertilizer production, and legume crop cultivation etc. In order to understand how climate system is perturbed by anthropogenic N2O emissions from the terrestrial biosphere, it is necessary to better estimate the pre-industrial N2O emissions. Previous estimations of natural N2O emissions from the terrestrial biosphere range from 3.3-9.0 Tg N2O-N yr-1. This large uncertainty in the estimation of pre-industrial N2O emissions from the terrestrial biosphere may be caused by uncertainty associated with key parameters such as maximum nitrification and denitrification rates, half-saturation coefficients of soil ammonium and nitrate, N fixation rate, and maximum N uptake rate. In addition to the large estimation range, previous studies did not provide an estimate on preindustrial N2O emissions at regional and biome levels. In this study, we applied a process-based coupled biogeochemical model to estimate the magnitude and spatial patterns of pre-industrial N2O fluxes at biome and continental scales as driven by multiple input data, including pre-industrial climate data, atmospheric CO2 concentration, N deposition, N fixation, and land cover types and distributions. Uncertainty associated with key parameters is also evaluated. Finally, we generate sector-based estimates of pre-industrial N2O emission, which provides a reference for assessing the climate forcing of anthropogenic N2O emission from the land biosphere.

Visual Programming per l'interfaccia utente di GEOPOI 2.0 in Sogei

Directory of Open Access Journals (Sweden)

Maurizio Rosina

2012-06-01

Full Text Available Da qualche tempo è  stato  coniato  il  termine  mass customization (personalizzazione di massa che vuo-le indicare la strategia per la produzione di beni e servizi orientata a soddisfare i bisogni individuali dei Clienti e  contemporaneamente  preservare  l’efficienza  della  pro-duzione  di  massa,  in  termini  di  bassi  costi  di  produzione e prezzi di vendita contenuti. Tradurre in pratica da parte delle imprese tale lodevole strategia non è assolutamente facile. Talvolta le imprese ripiegano su di una più persegui-bile strategia di adaptive customization (personalizzazione adattiva: ovvero l’impresa produce un prodotto standard,che  comunque  ha  in  sé  le  caratteristiche  di  poter  essere personalizzato - generalmente in modo reversibile - direttamente dal Cliente finale (nel caso di produzione di sw un esempio  potrebbe  essere  la  possibilità  di  cambiare in  un prodotto  o  servizio  standard  la  font  e  la dimensione  dei caratteri. Visual Programming for the GEOPOI 2.0 User interface in SOGEI The paper describes how to get GEOPOI 2.0-WUI using the techniques  of  Visual  Programming  and  simple  assembly  of widgets  via  drag  and  drop.  These  techniques  allow  for extremely fast and easy creation of customized GEOPOI 2.0-WUI (Web User Interfaces, achievable even by personnel with lit-tle or no knowledge of cartographic software programming, thus providing a useful tool to support the innovative software development  methodologies  that  go  under the name Agile Software Development.

Enhancing the ABAQUS thermomechanics code to simulate multipellet steady and transient LWR fuel rod behavior

International Nuclear Information System (INIS)

Williamson, R.L.

2011-01-01

Highlights: → The ABAQUS thermomechanics code is enhanced to enable simulation of nuclear fuel behavior. → Comparisons are made between discrete and smeared fuel pellet analysis. → Multidimensional and multipellet analysis is important for accurate prediction of PCMI. → Fully coupled thermomechanics results in very smooth prediction of fuel-clad gap closure. → A smeared-pellet approximation results in significant underprediction of clad radial displacements and plastic strain. - Abstract: A powerful multidimensional fuels performance analysis capability, applicable to both steady and transient fuel behavior, is developed based on enhancements to the commercially available ABAQUS general-purpose thermomechanics code. Enhanced capabilities are described, including: UO 2 temperature and burnup dependent thermal properties, solid and gaseous fission product swelling, fuel densification, fission gas release, cladding thermal and irradiation creep, cladding irradiation growth, gap heat transfer, and gap/plenum gas behavior during irradiation. This new capability is demonstrated using a 2D axisymmetric analysis of the upper section of a simplified multipellet fuel rod, during both steady and transient operation. Comparisons are made between discrete and smeared-pellet simulations. Computational results demonstrate the importance of a multidimensional, multipellet, fully-coupled thermomechanical approach. Interestingly, many of the inherent deficiencies in existing fuel performance codes (e.g., 1D thermomechanics, loose thermomechanical coupling, separate steady and transient analysis, cumbersome pre- and post-processing) are, in fact, ABAQUS strengths.

Development of pre-startup equipment for light water reactors

International Nuclear Information System (INIS)

Ram, Rajit; Borkar, S.P.; Dixit, M.Y.; Das, Debashis; Patil, R.K.

2010-01-01

Light water reactor (LWR) core typically has high excess reactivity as compared to Pressurized Heavy Water Reactor (PHWR). Unlike PHWR, where online refueling is done, LWR is operated for a long period to achieve maximum fuel burn-up before refueling. Since the reactivity is always reducing with burn-up of the core, the positions of control rods at criticality are always changing in a single direction, i.e. away from the core. Therefore it is possible to start the LWR even if the nuclear instrumentation is not online, provided the criticality position of control rods is known for previous operation. However, for the very first startup, the criticality position of control rods is required to be determined. A special nuclear instrumentation system, called Pre-startup equipment (PSE) is developed using two numbers of in-core detectors along with the processing electronics. The PSE enables operators to determine the criticality position of control rods for the first startup at zero power. The same equipment can also be used during loading of fuel assemblies. This paper discusses the features and architecture of PSE, its individual circuit blocks and specifications. (author)

77 FR 13009 - Regulation of Fuels and Fuel Additives: Identification of Additional Qualifying Renewable Fuel...

Science.gov (United States)

2012-03-05

... Regulation of Fuels and Fuel Additives: Identification of Additional Qualifying Renewable Fuel Pathways Under the Renewable Fuel Standard Program AGENCY: Environmental Protection Agency (EPA). ACTION: Withdrawal... Renewable Fuel Standard program regulations. Because EPA received adverse comment, we are withdrawing the...

Characterization of LWR fuel rod irradiations with power transients in the BR2 reflector

International Nuclear Information System (INIS)

Ponsard, B.; Bodart, S.; Meer, K. van der; Raedt, C. de

1996-01-01

Fuel rod irradiations in reflector positions of the materials testing reactor BR2 are becoming increasingly important. A typical example is that of irradiation devices containing single LWR fuel rods, to be tested in the framework of a new international fuel investigation and development programme. Some of the irradiations will comprise power transients with central fuel melting (at 2800 deg. C), the power increase being obtained by decreasing the pressure in a He-3 neutron absorbing screen and/or by varying the BR2 reactor operating power. A total power variation by a factor of at least 2.5 in the fuel rod irradiated could thus be achieved. In some of the rods, central temperature measurements (up to 2000 deg. C) will be carried out. Both fresh and pre-irradiated fuel rods are concerned in the programme. For these irradiations, the accurate knowledge of the neutron-induced fission heating and of the gamma heating is required, as one of the purposes of the programme consists in establishing the correlation among the thermal conductivity, the burn-up and the irradiation temperature. Calibration work among various measuring methods and between measurements and one- and two-dimensional calculations is being pursued. (author). 10 refs, 15 figs, 3 tabs

Nuclear fuels

International Nuclear Information System (INIS)

2008-01-01

The nuclear fuel is one of the key component of a nuclear reactor. Inside it, the fission reactions of heavy atoms, uranium and plutonium, take place. It is located in the core of the reactor, but also in the core of the whole nuclear system. Its design and properties influence the behaviour, the efficiency and the safety of the reactor. Even if it represents a weak share of the generated electricity cost, its proper use represents an important economic stake. Important improvements remain to be made to increase its residence time inside the reactor, to supply more energy, and to improve its robustness. Beyond the economical and safety considerations, strategical questions have to find an answer, like the use of plutonium, the management of resources and the management of nuclear wastes and real technological challenges have to be taken up. This monograph summarizes the existing knowledge about the nuclear fuel, its behaviour inside the reactor, its limits of use, and its R and D tracks. It illustrates also the researches in progress and presents some key results obtained recently. Content: 1 - Introduction; 2 - The fuel of water-cooled reactors: aspect, fabrication, behaviour of UO 2 and MOX fuels inside the reactor, behaviour in loss of tightness situation, microscopic morphology of fuel ceramics and evolution under irradiation - migration and localisation of fission products in UOX and MOX matrices, modeling of fuels behaviour - modeling of defects and fission products in the UO 2 ceramics by ab initio calculations, cladding and assembly materials, pellet-cladding interaction, advanced UO 2 and MOX ceramics, mechanical behaviour of the fuel assembly, fuel during a loss of coolant accident, fuel during a reactivity accident, fuel during a serious accident, fuel management inside reactor cores, fuel cycle materials balance, long-term behaviour of the spent fuel, fuel of boiling water reactors; 3 - the fuel of liquid metal fast reactors: fast neutrons radiation

Advanced Fuel Cycle Economic Analysis of Symbiotic Light-Water Reactor and Fast Burner Reactor Systems

Energy Technology Data Exchange (ETDEWEB)

D. E. Shropshire

2009-01-01

The Advanced Fuel Cycle Economic Analysis of Symbiotic Light-Water Reactor and Fast Burner Reactor Systems, prepared to support the U.S. Advanced Fuel Cycle Initiative (AFCI) systems analysis, provides a technology-oriented baseline system cost comparison between the open fuel cycle and closed fuel cycle systems. The intent is to understand their overall cost trends, cost sensitivities, and trade-offs. This analysis also improves the AFCI Program’s understanding of the cost drivers that will determine nuclear power’s cost competitiveness vis-a-vis other baseload generation systems. The common reactor-related costs consist of capital, operating, and decontamination and decommissioning costs. Fuel cycle costs include front-end (pre-irradiation) and back-end (post-iradiation) costs, as well as costs specifically associated with fuel recycling. This analysis reveals that there are large cost uncertainties associated with all the fuel cycle strategies, and that overall systems (reactor plus fuel cycle) using a closed fuel cycle are about 10% more expensive in terms of electricity generation cost than open cycle systems. The study concludes that further U.S. and joint international-based design studies are needed to reduce the cost uncertainties with respect to fast reactor, fuel separation and fabrication, and waste disposition. The results of this work can help provide insight to the cost-related factors and conditions needed to keep nuclear energy (including closed fuel cycles) economically competitive in the U.S. and worldwide. These results may be updated over time based on new cost information, revised assumptions, and feedback received from additional reviews.

Advanced Fuel Cycle Economic Analysis of Symbiotic Light-Water Reactor and Fast Burner Reactor Systems

International Nuclear Information System (INIS)

Shropshire, D.E.

2009-01-01

The Advanced Fuel Cycle Economic Analysis of Symbiotic Light-Water Reactor and Fast Burner Reactor Systems, prepared to support the U.S. Advanced Fuel Cycle Initiative (AFCI) systems analysis, provides a technology-oriented baseline system cost comparison between the open fuel cycle and closed fuel cycle systems. The intent is to understand their overall cost trends, cost sensitivities, and trade-offs. This analysis also improves the AFCI Program's understanding of the cost drivers that will determine nuclear power's cost competitiveness vis-a-vis other baseload generation systems. The common reactor-related costs consist of capital, operating, and decontamination and decommissioning costs. Fuel cycle costs include front-end (pre-irradiation) and back-end (post-irradiation) costs, as well as costs specifically associated with fuel recycling. This analysis reveals that there are large cost uncertainties associated with all the fuel cycle strategies, and that overall systems (reactor plus fuel cycle) using a closed fuel cycle are about 10% more expensive in terms of electricity generation cost than open cycle systems. The study concludes that further U.S. and joint international-based design studies are needed to reduce the cost uncertainties with respect to fast reactor, fuel separation and fabrication, and waste disposition. The results of this work can help provide insight to the cost-related factors and conditions needed to keep nuclear energy (including closed fuel cycles) economically competitive in the U.S. and worldwide. These results may be updated over time based on new cost information, revised assumptions, and feedback received from additional reviews.

Apparatus for loading fuel pellets in fuel rods

International Nuclear Information System (INIS)

Tedesco, R.J.

1976-01-01

An apparatus is disclosed for loading fuel pellets into fuel rods for a nuclear reactor including a base supporting a table having grooves therein for holding a multiplicity of pellets. Multiple fuel rods are placed in alignment with grooves in the pellet table and a guide member channels pellets from the table into the corresponding fuel rods. To effect movement of pellets inside the fuel rods without jamming, a number of electromechanical devices mounted on the base have arms connected to the lower surface of the fuel rod table which cyclically imparts a reciprocating arc motion to the table for moving the fuel pellets longitudinally of and inside the fuel rods. These electromechanical devices include a solenoid having a plunger therein connected to a leaf type spring, the arrangement being such that upon energization of the solenoid coil, the leaf spring moves the fuel rod table rearwardly and downwardly, and upon deenergization of the coil, the spring imparts an upward-forward movement to the table which results in physical displacement of fuel pellets in the fuel rods clamped to the table surface. 8 claims, 6 drawing figures

Hardened over-coating fuel particle and manufacture of nuclear fuel using its fuel particle

International Nuclear Information System (INIS)

Yoshimuda, Hideharu.

1990-01-01

Coated-fuel particles comprise a coating layer formed by coating ceramics such as silicon carbide or zirconium carbide and carbons, etc. to a fuel core made of nuclear fuel materials. The fuel core generally includes oxide particles such as uranium, thorium and plutonium, having 400 to 600 μm of average grain size. The average grain size of the coated-fuel particle is usually from 800 to 900 μm. The thickness of the coating layer is usually from 150 to 250 μm. Matrix material comprising a powdery graphite and a thermosetting resin such as phenol resin, etc. is overcoated to the surface of the coated-fuel particle and hardened under heating to form a hardened overcoating layer to the coated-fuel particle. If such coated-fuel particles are used, cracks, etc. are less caused to the coating layer of the coated-fuel particles upon production, thereby enabling to prevent the damages to the coating layer. (T.M.)

Fuel and fuel cycles with high burnup for WWER reactors

International Nuclear Information System (INIS)

Chernushev, V.; Sokolov, F.

2002-01-01

The paper discusses the status and trends in development of nuclear fuel and fuel cycles for WWER reactors. Parameters and main stages of implementation of new fuel cycles will be presented. At present, these new fuel cycles are offered to NPPs. Development of new fuel and fuel cycles based on the following principles: profiling fuel enrichment in a cross section of fuel assemblies; increase of average fuel enrichment in fuel assemblies; use of refuelling schemes with lower neutron leakage ('in-in-out'); use of integrated fuel gadolinium-based burnable absorber (for a five-year fuel cycle); increase of fuel burnup in fuel assemblies; improving the neutron balance by using structural materials with low neutron absorption; use of zirconium alloy claddings which are highly resistant to irradiation and corrosion. The paper also presents the results of fuel operation. (author)

A natural-law approach to human rights in a plural society

Directory of Open Access Journals (Sweden)

Parisoli, Luca

2010-10-01

Full Text Available I propose a medieval voluntaristic version of natural-law theory, as a plausible strategy to implement fundamental rights in a culturally non-homogeneous society; it is, in particular, the version proposed by the Franciscan school, which proposes a substantial cut between pre-lapsarian and post-lapsarian natural law (the former corresponding to the sphere of fundamental rights of persons while the lattrer marks the sphere of institutional rights of individuals in a given society, with a plurality of the common good. With necessary semantical precisions, this strategy safeguards the political value of tolerance and the real plurality of sundry cultural models withan one society, although such as belong to a certain culture are convinced it is superior to others. This strategy is opposed to ethical legalism, widespread in modern political debate, which I blame for its tendency to homogeneity and its reduction of plurality to non-culturality.

Propongo una versión voluntarista medieval del jusnaturalismo como estrategia plausible para implementar los derechos fundamentales en una sociedad culturalmente no-homogénea; trátase, en particular, de la versión de la escuela franciscana, que propone una discontinuidad sustancial entre el derecho natural que precede a la Caída (esfera de los derechos fundamentales de la persona y el derecho natural que sigue a la Caída (esfera de los derechos institucionales de los individuos de una sociedad dada, con una pluralidad del bien común. Tras las necesarias precisiones semánticas, esa estrategia conserva el valor político de la tolerancia y la pluralidad efectiva de los modelos culturales en una misma sociedad, aunque quienes pertenecen a una cultura determinada estén persuadidos de la superioridad de su propia cultura sobre las demás. Opónese esa estrategia al legalismo ético, difundido en el debate político contemporáneo, al cual critico por su tendencia homogeneizante y su reducción de la

Fuel Cell Power Plants Renewable and Waste Fuels

Science.gov (United States)

2011-01-13

logo, Direct FuelCell and “DFC” are all registered trademarks (®) of FuelCell Energy, Inc. Applications •On-site self generation of combined heat... of FuelCell Energy, Inc. Fuels Resources for DFC • Natural Gas and LNG • Propane • Biogas (by Anaerobicnaerobic Digestion) - Municipal Waste...FUEL RESOURCES z NATURAL GAS z PROPANE z DFC H2 (50-60%) z ETHANOL zWASTE METHANE z BIOGAS z COAL GAS Diversity of Fuels plus High Efficiency

Pre-treatment of substrates for biogas production - A systems analysis; Foerbehandling av biogassubstrat i systemanalys

Energy Technology Data Exchange (ETDEWEB)

Carlsson, My; Holmstroem, David; Lagerkvist, Anders; Bisaillon, Mattias

2013-09-01

The present expansion of biogas capacity responds to a growing demand for renewable vehicle fuels. Biodegradable wastes are attractive substrates and are also prioritized in national policy. The full potential of the substrates can rarely be used however. This is partly due to impurities, or the availability or degradation speed may be limiting the biogas yield. In both cases there is a need of pre-treatments. This work deals with the system impacts of pre-treatment aiming to remove impurities in food waste and pre-treatments aiming to improve the biogas yield of horse manure and ley. In the latter case steam explosion and extrusion were the treatments studied. Gas yields and the plant and system impacts on energy, climate and economic were studied. The system includes the biogas plant as well as the impact in supplementary systems for heat and power production. The three named substrates were identified to be highly prioritised due to their total potential and the improvements possible in its realisation. Existing information from literature and contacts has form the data basis, with the addition of a few supplementary analyses of substrates. The project has been operated by the authors with participation of a group of facility operators and external reviewers. Four plants have been visited during the study. Operators of digestion plants and all interested in developing the efficiency of biogas plants are the main target group for the study. The rate that the potential yield of food waste can be utilised depends largely on how efficiently contaminants can be separated without loss of substrate. In this case the separation degree has the main impact on the economy, but not a pronounced climate effect. For all types of pre-treatments the water content of substrates is important, a higher water content is detrimental to economy, energy demand and climate impact. For both the energy balance and the climate impact the generation of vehicle fuel has a large impact. An

Fuel-cycle cost comparisons with oxide and silicide fuels

International Nuclear Information System (INIS)

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

1982-01-01

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

AECL experience in fuel channel inspection

Energy Technology Data Exchange (ETDEWEB)

Van Drunen, G. [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada); Gunn, R. [Atomic Energy of Canada Limited, Mississauga, Ontario (Canada); Mayo, W.R. [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada); Scott, D.A. [Atomic Energy of Canada Limited, Mississauga, Ontario (Canada)

1999-06-01

Inspection of CANDU fuel channels (FC) is performed to ensure safe and economic reactor operation. CANDU reactor FCs have features that make them a unique non-destructive testing (NDT) challenge. The thin, 4 mm pressure-tube wall means flaws down to about 0.1 mm deep must be reliably detected and characterized. This is one to two orders of magnitude smaller than is usually considered of significant concern for steel piping and pressure vessels. A second unique feature is that inspection sensors must operate in the reactor core--often within 20 cm of highly radioactive fuel. Work on inspection of CANDU reactor FCs at AECL dates back over three decades. In that time, AECL staff have provided equipment and conducted or supervised in-service inspections in about 250 FCs, in addition to over 8000 pre-service FCs. These inspections took place at every existing CANDU reactor except those in India and Romania. Early FC inspections focussed on measurement of changes in dimensions (gauging) resulting from exposure to a combination of neutrons, stress and elevated temperature. Expansion of inspection activities to include volumetric inspection (for flaws) started in the mid-1970s with the discovery of delayed hydride cracking in Pickering 3 and 4 rolled joints. Recognition of other types of flaw mechanisms in the 1980s led to further expansion in both pre-service and in-service inspections. These growing requirements, to meet regulatory as well as economic needs, led to the development of a wide spectrum of inspection technology that now includes tests for hydrogen concentration, structural integrity of core components, flaws, and dimensional change. This paper reviews current CANDU reactor FC inspection requirements. The equipment and techniques developed to satisfy these requirements are also described. The paper concludes with a discussion of work in progress in AECL aimed at providing state-of-the-art FC inspection services. (author)

Simulating fuel behavior under transient conditions using FRAPTRAN and uncertainty analysis using Dakota

International Nuclear Information System (INIS)

Gomes, Daniel S.; Teixeira, Antonio S.

2017-01-01

Although regulatory agencies have shown a special interest in incorporating best estimate approaches in the fuel licensing process, fuel codes are currently licensed based on only the deterministic limits such as those seen in 10CRF50, and therefore, may yield unrealistic safety margins. The concept of uncertainty analysis is employed to more realistically manage this risk. In this study, uncertainties were classified into two categories: probabilistic and epistemic (owing to a lack of pre-existing knowledge in this area). Fuel rods have three sources of uncertainty: manufacturing tolerance, boundary conditions, and physical models. The first step in successfully analyzing the uncertainties involves performing a statistical analysis on the input parameters used throughout the fuel code. The response obtained from this analysis must show proportional index correlations because the uncertainties are globally propagated. The Dakota toolkit was used to analyze the FRAPTRAN transient fuel code. The subsequent sensitivity analyses helped in identifying the key parameters with the highest correlation indices including the peak cladding temperature and the time required for cladding failures. The uncertainty analysis was performed using an IFA-650-5 fuel rod, which was in line with the tests performed in the Halden Project in Norway. The main objectives of the Halden project included studying the ballooning and rupture processes. The results of this experiment demonstrate the accuracy and applicability of the physical models in evaluating the thermal conductivity, mechanical model, and fuel swelling formulations. (author)

Simulating fuel behavior under transient conditions using FRAPTRAN and uncertainty analysis using Dakota

Energy Technology Data Exchange (ETDEWEB)

Gomes, Daniel S.; Teixeira, Antonio S., E-mail: dsgomes@ipen.br, E-mail: teixeira@ipen [Instituto de Pesquisas Energéticas e Nucleares (IPEN/CNEN-SP), São Paulo, SP (Brazil)

2017-07-01

Although regulatory agencies have shown a special interest in incorporating best estimate approaches in the fuel licensing process, fuel codes are currently licensed based on only the deterministic limits such as those seen in 10CRF50, and therefore, may yield unrealistic safety margins. The concept of uncertainty analysis is employed to more realistically manage this risk. In this study, uncertainties were classified into two categories: probabilistic and epistemic (owing to a lack of pre-existing knowledge in this area). Fuel rods have three sources of uncertainty: manufacturing tolerance, boundary conditions, and physical models. The first step in successfully analyzing the uncertainties involves performing a statistical analysis on the input parameters used throughout the fuel code. The response obtained from this analysis must show proportional index correlations because the uncertainties are globally propagated. The Dakota toolkit was used to analyze the FRAPTRAN transient fuel code. The subsequent sensitivity analyses helped in identifying the key parameters with the highest correlation indices including the peak cladding temperature and the time required for cladding failures. The uncertainty analysis was performed using an IFA-650-5 fuel rod, which was in line with the tests performed in the Halden Project in Norway. The main objectives of the Halden project included studying the ballooning and rupture processes. The results of this experiment demonstrate the accuracy and applicability of the physical models in evaluating the thermal conductivity, mechanical model, and fuel swelling formulations. (author)

Fuel temperature characteristics of the 37-element and CANFLEX fuel bundle

International Nuclear Information System (INIS)

Bae, Jun Ho; Rho, Gyu Hong; Park, Joo Hwan

2009-10-01

This report describes the fuel temperature characteristics of CANFLEX fuel bundles and 37-element fuel bundles for a different burnup of fuel. The program was consisted for seeking the fuel temperature of fuel bundles of CANFLEX fuel bundles and 37-element fuel bundles by using the method in NUCIRC. Fuel temperature has an increasing pattern with the burnup of fuel for CANFLEX fuel bundles and 37-element fuel bundles. For all the case of burnup, the fuel temperature of CANFLEX fuel bundles has a lower value than that of 37-element fuel bundles. Especially, for the high power channel, the CANFLEX fuel bundles show a lower fuel temperature as much as about 75 degree, and the core averaged fuel temperature has a lower fuel temperature of about 50 degree than that of 37-element fuel bundles. The lower fuel temperature of CANFLEX fuel bundles is expected to enhance the safety by reducing the fuel temperature coefficient. Finally, for each burnup of CANFLEX fuel bundles and 37-element fuel bundles, the equation was present for predicting the fuel temperature of a bundle in terms of a coolant temperature and bundle power

Nuclear fuels

International Nuclear Information System (INIS)

Gangwani, Saloni; Chakrabortty, Sumita

2011-01-01

Nuclear fuel is a material that can be consumed to derive nuclear energy, by analogy to chemical fuel that is burned for energy. Nuclear fuels are the most dense sources of energy available. Nuclear fuel in a nuclear fuel cycle can refer to the fuel itself, or to physical objects (for example bundles composed of fuel rods) composed of the fuel material, mixed with structural, neutron moderating, or neutron reflecting materials. Long-lived radioactive waste from the back end of the fuel cycle is especially relevant when designing a complete waste management plan for SNF. When looking at long-term radioactive decay, the actinides in the SNF have a significant influence due to their characteristically long half-lives. Depending on what a nuclear reactor is fueled with, the actinide composition in the SNF will be different. The following paper will also include the uses. advancements, advantages, disadvantages, various processes and behavior of nuclear fuels

Guidebook on non-destructive examination of water reactor fuel

International Nuclear Information System (INIS)

1991-01-01

To date, a significant quantity of data has been collected and published on power reactor fuel examination to determine the performance when subjected to radiation. The data have been published in technical reports and papers in technical journals. However, the usefulness of the published data to the IAEA Member States is limited. This is due to a number of reasons, including the large variety of examination methods, incomplete documentation of the data and lack of sufficiently detailed information on pre-irradiation data and irradiation history. To alleviate some of these problems, the Agency initiated a Co-ordinated Research Programme in 1983 entitled ''Examination and Documentation Methodology for Water Reactor Fuel''. The programme meetings usually involved technical contributions from the programme participants, followed by a detailed discussion of the various examination methods presented in these contributions. Based on these discussions and contributions, a guidebook on the examination and documentation methodology for light and heavy water reactor fuel has been prepared. The guidebook addresses the most commonly used examination methods for the various water reactor fuel systems. Limitations of each of the measurement techniques are also discussed, including their accuracy and precision. A detailed description of the measurement equipment is given and the common methods of documenting the data are also addressed. With the adoption of the uniform set of procedures and documentation methods, it is hoped that the IAEA Member States will be able to use effectively both the existing data and the future data from the various national programmes. It is also expected that this guidebook will be useful for adaptation of measurement techniques that are unique to specific fuel systems to other fuel types. 59 refs, 33 figs, 4 tabs

Autoignited and non-autoignited lifted flames of pre-vaporized n-heptane in coflow jets at elevated temperatures

KAUST Repository

Choi, Sangkyu

2013-09-01

The characteristics of laminar lifted flames of pre-vaporized n-heptane in coflow jets were investigated under both non-autoignited and autoignited conditions by varying the initial temperature. The fuel tested was n-heptane considering the importance as a primary reference fuel for gasoline and its low temperature ignition behavior at relatively low pressure. The results showed that the lifted flame edge in the non-autoignited regime had a tribrachial structure with lean and rich premixed flame wings together with a trailing diffusion flame. The liftoff heights correlated reasonably well with the fuel jet velocity scaled by the stoichiometric laminar burning velocity regardless of the initial temperature and the nitrogen dilution. The liftoff velocity multiplied by the buoyancy-induced velocity and the blowout velocity scaled by the mole fraction of the fuel correlated well with the stoichiometric laminar burning velocity. When the initial temperature was above 900. K, flames were autoignited without any external ignition source. Autoignited lifted flames with both tribrachial edges and mild combustion characteristics were observed. The correlation of the liftoff height with the calculated adiabatic ignition delay time was weak, unlike in cases with gaseous fuels of C1-C4 hydrocarbons in which the liftoff height of the autoignited flames correlated well with the square of the adiabatic ignition delay time. When the mole fraction of the fuel was small, mild combustion behaviors were exhibited with edge flames without distinct tribrachial structures. The liftoff height was correlated with the fuel jet velocity scaled by the initial fuel mass fraction, while the dependence on the ignition delay time was weak when compared with the gaseous fuels. © 2013 The Combustion Institute.

Checklist for transition to new highway fuel(s).

Energy Technology Data Exchange (ETDEWEB)

Risch, C.; Santini, D.J. (Energy Systems)

2011-12-15

Transportation is vital to the U.S. economy and society. As such, U.S. Presidents have repeatedly stated that the nation needs to reduce dependence on petroleum, especially for the highway transportation sector. Throughout history, highway transportation fuel transitions have been completed successfully both in United States and abroad. Other attempts have failed, as described in Appendix A: Historical Highway Fuel Transitions. Planning for a transition is critical because the changes can affect our nation's ability to compete in the world market. A transition will take many years to complete. While it is tempting to make quick decisions about the new fuel(s) of choice, it is preferable and necessary to analyze all the pertinent criteria to ensure that correct decisions are made. Doing so will reduce the number of changes in highway fuel(s). Obviously, changes may become necessary because of occurrences such as significant technology breakthroughs or major world events. With any and all of the possible transitions to new fuel(s), the total replacement of gasoline and diesel fuels is not expected. These conventional fuels are envisioned to coexist with the new fuel(s) for decades, while the revised fuel and vehicle infrastructures are implemented. The transition process must analyze the needs of the primary 'players,' which consist of the customers, the government, the fuel industry, and the automotive industry. To maximize the probability of future successes, the prime considerations of these groups must be addressed. Section 2 presents a succinct outline of the Checklist. Section 3 provides a brief discussion about the groupings on the Checklist.

Wood fuel from early thinning and plantation cleaning. Summary of an international review

International Nuclear Information System (INIS)

Puttock, D.

1998-01-01

This paper summaries the results of an international of wood fuel from early thinning and plantation cleaning. The economic and biological benefits from early thinning have been well documented. However, removing forest biomass during early stages of stand development from sites which are low in one or more nutrients may contribute a loss of nutrients and organic matter. Depending on the pre-thinning density and the thinning intensity, the potential yield of wood fuel from early thinning may be as much as 79 dry tons per hectare. Thus, wood fuel from the thinnings could be an important source of revenue to forest owners and would contribute to domestic energy requirements. Motor-manual felling predominates in early thinning, mainly due to the lack of appropriate technology for thinning small trees. However, the productivity of motor-manual felling is greatly affected by the initial stand density and declines dramatically at densities greater than 10 000 stems per ha. Under these conditions, purpose-built wood fuel harvesters with small-tree harvesting capability offer the greatest potential for increasing felling productivity and reducing the cost of wood fuel. The cost of wood fuel from early thinnings varies widely between countries from USD 25.00 - 87.50 per dry ton depending on stand conditions, harvesting system, transport distance, domestic tax rates, and stumpage prices. At the low end of this range, wood fuel chips from early thinning are competitive with wood fuel produced from mill waste, the residues from clearfell operations, or from later thinnings

75 FR 37733 - Regulation of Fuels and Fuel Additives: Modifications to Renewable Fuel Standard Program

Science.gov (United States)

2010-06-30

... Regulation of Fuels and Fuel Additives: Modifications to Renewable Fuel Standard Program AGENCY... direct final rule to amend the Renewable Fuel Standard program requirements on May 10, 2010. Because EPA... Fuel Standard program requirements, published on May 10, 2010. We stated in that direct final rule that...

77 FR 72746 - Regulation of Fuels and Fuel Additives: Modifications to Renewable Fuel Standard and Diesel...

Science.gov (United States)

2012-12-06

... Fuels and Fuel Additives: Modifications to Renewable Fuel Standard and Diesel Sulfur Programs AGENCY... Fuel Standard (``RFS'') program under section 211(o) of the Clean Air Act. The direct final rule also... marine diesel fuel produced by transmix processors, and the fuel marker requirements for 500 ppm sulfur...

LWR fuel rod testing facilities in high flux reactor (HFT) Petten for investigation of power cycling and ramping behaviour

Energy Technology Data Exchange (ETDEWEB)

Markgraf, J; Perry, D; Oudaert, J [Commission of the European Communities, Joint Reserach Centre, Petten Establishment, Petten (Netherlands)

1983-06-01

LWR fuel rod irradiation experiments are being performed in HFR's Pool Side Facility (PSF) by means of pressurized boiling water capsules (BWFC). For more than 6 years the major application of these devices has been in performing irradiation programs to investigate the power ramp behaviour of PWR and BWR rods which have been pre-irradiated in power reactors. Irradiation devices with various types of monitoring instrumentation are available, e.g. for fuel rod length, fuel stack length, fuel rod internal pressure and fuel rod central temperature measurements. The application scope covers PWR and BWR fuel rods, with burn-up levels up to 45 MWd/kg(U), max. linear heat generation rates up to 700 W/cm and simulation of constant power change rates between 0.05 and 1000 W/cm.min. The paper describes the different designs of LWR fuel rod testing facilities and associated non-destructive testing devices in use at the HFR Petten. It also addresses the new test capabilities that will become available after exchange of the HFR vessel in 1983. Furthermore it shows some typical results. (author)

Alternate-Fueled Flight: Halophytes, Algae, Bio-, and Synthetic Fuels

Science.gov (United States)

Hendricks, R. C.

2012-01-01

Synthetic and biomass fueling are now considered to be near-term aviation alternate fueling. The major impediment is a secure sustainable supply of these fuels at reasonable cost. However, biomass fueling raises major concerns related to uses of common food crops and grasses (some also called "weeds") for processing into aviation fuels. These issues are addressed, and then halophytes and algae are shown to be better suited as sources of aerospace fuels and transportation fueling in general. Some of the history related to alternate fuels use is provided as a guideline for current and planned alternate fuels testing (ground and flight) with emphasis on biofuel blends. It is also noted that lessons learned from terrestrial fueling are applicable to space missions. These materials represent an update (to 2009) and additions to the Workshop on Alternate Fueling Sustainable Supply and Halophyte Summit at Twinsburg, Ohio, October 17 to 18, 2007.

Increased fuel burn-up and fuel cycle equilibrium

International Nuclear Information System (INIS)

Debes, M.

2001-01-01

Improvement of nuclear competitiveness will rely mainly on increased fuel performance, with higher burn-up, and reactors sustained life. Regarding spent fuel management, the EDF current policy relies on UO 2 fuel reprocessing (around 850 MTHM/year at La Hague) and MOX recycling to ensure plutonium flux adequacy (around 100 MTHM/year, with an electricity production equivalent to 30 TWh). This policy enables to reuse fuel material, while maintaining global kWh economy with existing facilities. It goes along with current perspective to increase fuel burn-up up to 57 GWday/t mean in 2010. The following presentation describes the consequences of higher fuel burn-up on fuel cycle and waste management and implementation of a long term and global equilibrium for decades in spent fuel management resulting from this strategy. (author)

Fuel-Coolant Interactions - some Basic Studies at the UKAEA Culham Laboratory

International Nuclear Information System (INIS)

Reynolds, J.A.; Dullforce, T.A.; Peckover, R.S.; Vaughan, G.J.

1976-01-01

In a hypothetical fault sequence important effects of fuel-coolant interactions include voiding and dispersion of core debris as well as the pressure damage usually discussed. The development of the fuel-coolant interaction probably depends on any pre-mixing Weber break-up that may occur, and is therefore a function of the way the fuel and coolant come together. Four contact modes are identified: jetting, shock tube, drops and static, and Culham's experiments have been mainly concerned with simulating the falling drop mode by using molten tin in water. It was observed that the fuel-coolant interaction is a short series of violent coolant oscillations centred at a localized position on the drop, generating a spray of submillimeter sized debris. The interaction started spontaneously at a specific time after the drop first contacted the water. There was a definite limited fuel-coolant interaction zone on a plot of initial coolant temperature versus initial fuel temperature outside which interactions never occurred. The. interaction time was a function of the initial temperatures. Theoretical scaling formulae are given which describe the fuel-coolant interaction zone and dwell time. Bounds of fuel and coolant temperature below which fuel-coolant interactions do not occur are explained by freezing. Upper bounds of fuel and coolant temperatures above which there were no fuel-coolant interactions are interpreted in terms of heat transfer through vapour films of various thicknesses. In conclusion: We have considered the effects of fuel-coolant interactions in a hypothetical fault sequence, emphasising that debris and vapour production as well as the pressure pulse can be important factors. The fuel-coolant interaction has been classified into types, according to possible modes of mixing in the fault sequence. Culham has been studying one type, the self-triggering of falling drops, by simulant experiments. It is found that there is a definite zone of interaction on a plot

Control issues in oxy-fuel combustion

Energy Technology Data Exchange (ETDEWEB)

Snarheim, Dagfinn

2009-08-15

Combustion of fossil fuels is the major energy source in todays society. While the use of fossil fuels is a necessity for our society to function, there has been an increasing concern on the emissions of CO{sub 2} resulting from human activities. Emissions of CO{sub 2} are considered to be the main cause for the global warming and climate changes we have experienced in recent years. To fight the climate changes, the emissions of CO{sub 2} must be reduced in a timely fashion. Strategies to achieve this include switching to less carbon intensive fuels, renewable energy sources, nuclear energy and combustion with CO{sub 2} capture. The use of oxy-fuel combustion is among the alternative post- and pre combustion capture concepts, a strategy to achieve power production from fossil fuels with CO{sub 2} capture. In an oxy-fuel process, the fuel is burned in a mixture of oxygen and CO{sub 2} (or steam), leaving the exhaust consisting mainly of CO{sub 2} and steam. The steam can be removed by use of a condenser, leaving (almost) pure CO{sub 2} ready to be captured. The downside to CO{sub 2} capture is that it is expensive, both in capital cost of extra equipment, and in operation as it costs energy to capture the CO{sub 2}. Thus it is important to maximize the efficiency in such plants. One attractive concept to achieve CO{sub 2} capture by use of oxy-fuel, is a semi-closed oxy-fuel gas turbine cycle. The dynamics of such a plant are highly integrated, involving energy and mass recycle, and optimizing efficiency might lead to operational (control) challenges. In these thesis we investigate how such a power cycle should be controlled. By looking at control at such an early stage in the design phase, it is possible to find control solutions otherwise not feasible, that leads to better overall performance. Optimization is used on a nonlinear model based on first principles, to compare different control structures. Then, closed loop simulations using MPC, are used to validate

High density fuels using dispersion and monolithic fuel

Energy Technology Data Exchange (ETDEWEB)

Gomes, Daniel S.; Silva, Antonio T.; Abe, Alfredo Y.; Muniz, Rafael O.R.; Giovedi, Claudia, E-mail: dsgomes@ipen.br, E-mail: teixeira@ipen.br, E-mail: alfredo@ctmsp.mar.mil.br, E-mail: rafael.orm@gmail.com, E-mail: claudia.giovedi@ctmsp.mar.mil.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Universidade de São Paulo (USP), SP (Brazil). Departamento de Engenharia Naval e Oceânica

2017-07-01

Fuel plates used in high-performance research reactors need to be converted to low-enrichment uranium fuel; the fuel option based on a monolithic formulation requires alloys to contain 6 - 10 wt% Mo. In this case, the fuel plates are composed of the metallic alloy U-10Mo surrounded by a thin zirconium layer encapsulated in aluminum cladding. This study reviewed the physical properties of monolithic forms. The constraints produced during the manufacturing process were analyzed and compared to those of dispersed fuel. The bonding process used for dispersion fuels differs from the techniques applied to foil bonding used for pure alloys. The quality of monolithic plates depends on the fabrication method, which usually involves hot isostatic pressing and the thermal annealing effect of residual stress, which degrades the uranium cubic phase. The preservation of the metastable phase has considerable influence on fuel performance. The physical properties of the foil fuel under irradiation are superior to those of aluminum-dispersed fuels. The fuel meat, using zirconium as the diffusion barrier, prevents the interaction layer from becoming excessively thick. The problem with dispersed fuel is breakaway swelling with a medium fission rate. It has been observed that the fuel dispersed in aluminum was minimized in monolithic forms. The pure alloys exhibited a suitable response from a rate at least twice as much as the fission rate of dispersions. The foils can support fissile material concentration combined with a reduced swelling rate. (author)

High density fuels using dispersion and monolithic fuel

International Nuclear Information System (INIS)

Gomes, Daniel S.; Silva, Antonio T.; Abe, Alfredo Y.; Muniz, Rafael O.R.; Giovedi, Claudia; Universidade de São Paulo

2017-01-01

Fuel plates used in high-performance research reactors need to be converted to low-enrichment uranium fuel; the fuel option based on a monolithic formulation requires alloys to contain 6 - 10 wt% Mo. In this case, the fuel plates are composed of the metallic alloy U-10Mo surrounded by a thin zirconium layer encapsulated in aluminum cladding. This study reviewed the physical properties of monolithic forms. The constraints produced during the manufacturing process were analyzed and compared to those of dispersed fuel. The bonding process used for dispersion fuels differs from the techniques applied to foil bonding used for pure alloys. The quality of monolithic plates depends on the fabrication method, which usually involves hot isostatic pressing and the thermal annealing effect of residual stress, which degrades the uranium cubic phase. The preservation of the metastable phase has considerable influence on fuel performance. The physical properties of the foil fuel under irradiation are superior to those of aluminum-dispersed fuels. The fuel meat, using zirconium as the diffusion barrier, prevents the interaction layer from becoming excessively thick. The problem with dispersed fuel is breakaway swelling with a medium fission rate. It has been observed that the fuel dispersed in aluminum was minimized in monolithic forms. The pure alloys exhibited a suitable response from a rate at least twice as much as the fission rate of dispersions. The foils can support fissile material concentration combined with a reduced swelling rate. (author)

Fuel rod behaviour at high burnup WWER fuel cycles

International Nuclear Information System (INIS)

Medvedev, A.; Bogatyr, S.; Kouznetsov, V.; Khvostov, G.; Lagovsky; Korystin, L.; Poudov, V.

2003-01-01

The modernisation of WWER fuel cycles is carried out on the base of complete modelling and experimental justification of fuel rods up to 70 MWd/kgU. The modelling justification of the reliability of fuel rod and fuel rod with gadolinium is carried out with the use of certified START-3 code. START-3 code has a continuous experimental support. The thermophysical and strength reliability of WWER-440 fuel is justified for fuel rod and pellet burnups 65 MWd/kgU and 74 MWd/U, accordingly. Results of analysis are demonstrated by the example of uranium-gadolinium fuel assemblies of second generation under 5-year cycle with a portion of 6-year assemblies and by the example of successfully completed pilot operation of 5-year cycle fuel assemblies during 6 years at unit 3 of Kolskaja NPP. The thermophysical and strength reliability of WWER-1000 fuel is justified for a fuel rod burnup 66 MWd/kgU by the example of fuel operation under 4-year cycles and 6-year test operation of fuel assemblies at unit 1 of Kalininskaya NPP. By the example of 5-year cycle at Dukovany NPP Unit 2 it was demonstrated that WWER fuel rod of a burnup 58 MWd/kgU ensure reliable operation under load following conditions. The analysis has confirmed sufficient reserves of Russian fuel to implement program of JSC 'TVEL' in order to improve technical and economical parameters of WWER fuel cycles

78 FR 62462 - Regulation of Fuels and Fuel Additives: Modifications to Renewable Fuel Standard Program

Science.gov (United States)

2013-10-22

... renewable fuel is defined as fuel produced from renewable biomass that is used to replace or reduce the quantity of fossil fuel present in home heating oil or jet fuel.\\3\\ In essence, additional renewable fuel... of ``home heating oil.'' EPA determined that this term was ambiguous, and defined it by incorporating...

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.

Fuel processing

International Nuclear Information System (INIS)

Allardice, R.H.

1990-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

Agrawal, Ajay; Taylor, Robert

2013-09-30

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

Low contaminant formic acid fuel for direct liquid fuel cell

Science.gov (United States)

Masel, Richard I [Champaign, IL; Zhu, Yimin [Urbana, IL; Kahn, Zakia [Palatine, IL; Man, Malcolm [Vancouver, CA

2009-11-17

A low contaminant formic acid fuel is especially suited toward use in a direct organic liquid fuel cell. A fuel of the invention provides high power output that is maintained for a substantial time and the fuel is substantially non-flammable. Specific contaminants and contaminant levels have been identified as being deleterious to the performance of a formic acid fuel in a fuel cell, and embodiments of the invention provide low contaminant fuels that have improved performance compared to known commercial bulk grade and commercial purified grade formic acid fuels. Preferred embodiment fuels (and fuel cells containing such fuels) including low levels of a combination of key contaminants, including acetic acid, methyl formate, and methanol.

Fuel gases

International Nuclear Information System (INIS)

Anon.

1996-01-01

This paper gives a brief presentation of the context, perspectives of production, specificities, and the conditions required for the development of NGV (Natural Gas for Vehicle) and LPG-f (Liquefied Petroleum Gas fuel) alternative fuels. After an historical presentation of 80 years of LPG evolution in vehicle fuels, a first part describes the economical and environmental advantages of gaseous alternative fuels (cleaner combustion, longer engines life, reduced noise pollution, greater natural gas reserves, lower political-economical petroleum dependence..). The second part gives a comparative cost and environmental evaluation between the available alternative fuels: bio-fuels, electric power and fuel gases, taking into account the processes and constraints involved in the production of these fuels. (J.S.)

Fuel quality issues in stationary fuel cell systems.

Energy Technology Data Exchange (ETDEWEB)

Papadias, D.; Ahmed, S.; Kumar, R. (Chemical Sciences and Engineering Division)

2012-02-07

Fuel cell systems are being deployed in stationary applications for the generation of electricity, heat, and hydrogen. These systems use a variety of fuel cell types, ranging from the low temperature polymer electrolyte fuel cell (PEFC) to the high temperature solid oxide fuel cell (SOFC). Depending on the application and location, these systems are being designed to operate on reformate or syngas produced from various fuels that include natural gas, biogas, coal gas, etc. All of these fuels contain species that can potentially damage the fuel cell anode or other unit operations and processes that precede the fuel cell stack. These detrimental effects include loss in performance or durability, and attenuating these effects requires additional components to reduce the impurity concentrations to tolerable levels, if not eliminate the impurity entirely. These impurity management components increase the complexity of the fuel cell system, and they add to the system's capital and operating costs (such as regeneration, replacement and disposal of spent material and maintenance). This project reviewed the public domain information available on the impurities encountered in stationary fuel cell systems, and the effects of the impurities on the fuel cells. A database has been set up that classifies the impurities, especially in renewable fuels, such as landfill gas and anaerobic digester gas. It documents the known deleterious effects on fuel cells, and the maximum allowable concentrations of select impurities suggested by manufacturers and researchers. The literature review helped to identify the impurity removal strategies that are available, and their effectiveness, capacity, and cost. A generic model of a stationary fuel-cell based power plant operating on digester and landfill gas has been developed; it includes a gas processing unit, followed by a fuel cell system. The model includes the key impurity removal steps to enable predictions of impurity breakthrough

Fuel cells for electricity generation from carbonaceous fuels

Energy Technology Data Exchange (ETDEWEB)

Ledjeff-Hey, K; Formanski, V; Roes, J [Gerhard-Mercator- Universitaet - Gesamthochschule Duisburg, Fachbereich Maschinenbau/Fachgebiet Energietechnik, Duisburg (Germany); Heinzel, A [Fraunhofer Inst. for Solar Energy Systems (ISE), Freiburg (Germany)

1998-09-01

Fuel cells, which are electrochemical systems converting chemical energy directly into electrical energy with water and heat as by-products, are of interest as a means of generating electricity which is environmentally friendly, clean and highly efficient. They are classified according to the electrolyte used. The main types of cell in order of operating temperature are described. These are: alkaline fuel cells, the polymer electrolyte membrane fuel cell (PEMFC); the phosphoric acid fuel cell (PAFC); the molten carbonate fuel cell (MCFC); the solid oxide fuel cell (SOFC). Applications depend on the type of cell and may range from power generation on a large scale to mobile application in cars or portable systems. One of the most promising options is the PEM-fuel cell stack where there has been significant improvement in power density in recent years. The production from carbonaceous fuels and purification of the cell fuel, hydrogen, is considered. Of the purification methods available, hydrogen separation by means of palladium alloy membranes seems particular effective in reducing CO concentrations to the low levels required for PEM cells. (UK)

Fuel cells : a viable fossil fuel alternative

Energy Technology Data Exchange (ETDEWEB)

Paduada, M.

2007-02-15

This article presented a program initiated by Natural Resources Canada (NRCan) to develop proof-of-concept of underground mining vehicles powered by fuel cells in order to eliminate emissions. Recent studies on American and Canadian underground mines provided the basis for estimating the operational cost savings of switching from diesel to fuel cells. For the Canadian mines evaluated, the estimated ventilation system operating cost reductions ranged from 29 per cent to 75 per cent. In order to demonstrate the viability of a fuel cell-powered vehicle, NRCan has designed a modified Caterpillar R1300 loader with a 160 kW hybrid power plant in which 3 stacks of fuel cells deliver up to 90 kW continuously, and a nickel-metal hydride battery provides up to 70 kW. The battery subsystem transiently boosts output to meet peak power requirements and also accommodates regenerative braking. Traction for the loader is provided by a brushless permanent magnet traction motor. The hydraulic pump motor is capable of a 55 kW load continuously. The loader's hydraulic and traction systems are operated independently. Future fuel cell-powered vehicles designed by the program may include a locomotive and a utility vehicle. Future mines running their operations with hydrogen-fueled equipment may also gain advantages by employing fuel cells in the operation of handheld equipment such as radios, flashlights, and headlamps. However, the proton exchange membrane (PEM) fuel cells used in the project are prohibitively expensive. The catalytic content of a fuel cell can add hundreds of dollars per kW of electric output. Production of catalytic precious metals will be strongly connected to the scale of use and acceptance of fuel cells in vehicles. In addition, the efficiency of hydrogen production and delivery is significantly lower than the well-to-tank efficiency of many conventional fuels. It was concluded that an adequate hydrogen infrastructure will be required for the mining industry

Applying hot-wire anemometry to directly measure the water balance in a proton exchange membrane fuel cell for a pre-humidified hydrogen stream

DEFF Research Database (Denmark)

Berning, Torsten; Shakhshir, Saher Al

2016-01-01

In a recent publication it has been shown how the water balance in a proton exchange membrane fuel cell can be determined employing hot wire anemometry. The hot wire sensor has to be placed into the anode outlet pipe of the operating fuel cell, and the voltage signal E that is read from the senso....... Finally, it will be shown how previously developed dew point diagrams for the anode side in a fuel cell can be corrected for a humidified hydrogen inlet stream....

Cold spray copper coatings for used fuel containers

Energy Technology Data Exchange (ETDEWEB)

Keech, P. [Nuclear Waste Management Organization, Toronto, ON (Canada); Vo, P.; Poirier, D.; Legoux, J-G [National Research Council, Boucherville QC, (Canada)

2015-07-01

Recently, the Nuclear Waste Management Organization has been developing copper coatings as a method of protecting steel used fuel containers (UFCs) from corrosion within a deep geological repository. The corrosion barrier design is based on the application of a copper coating bonded directly to the exterior surface of the UFC structural core. Copper coating technologies amendable to supply of pre-coated UFC vessel components and application to the weld zone following UFC closure within the radiological environment have been investigated. Copper cold spray has been assessed for both operations; this paper outlines the research and development to date of this technique. (author)

Opportunities for mixed oxide fuel testing in the advanced test reactor to support plutonium disposition

International Nuclear Information System (INIS)

Terry, W.K.; Ryskamp, J.M.; Sterbentz, J.W.

1995-08-01

Numerous technical issues must be resolved before LWR operating licenses can be amended to allow the use of MOX fuel. These issues include the following: (1) MOX fuel fabrication process verification; (2) Whether and how to use burnable poisons to depress MOX fuel initial reactivity, which is higher than that of urania; (3) The effects of WGPu isotopic composition; (4) The feasibility of loading MOX fuel with plutonia content up to 7% by weight; (5) The effects of americium and gallium in WGPu; (6) Fission gas release from MOX fuel pellets made from WGPu; (7) Fuel/cladding gap closure; (8) The effects of power cycling and off-normal events on fuel integrity; (9) Development of radial distributions of burnup and fission products; (10) Power spiking near the interfaces of MOX and urania fuel assemblies; and (11) Fuel performance code validation. The Advanced Test Reactor (ATR) at the Idaho National Engineering Laboratory possesses many advantages for performing tests to resolve most of the issues identified above. We have performed calculations to show that the use of hafnium shrouds can produce spectrum adjustments that will bring the flux spectrum in ATR test loops into a good approximation to the spectrum anticipated in a commercial LWR containing MOX fuel while allowing operation of the test fuel assemblies near their optimum values of linear heat generation rate. The ATR would be a nearly ideal test bed for developing data needed to support applications to license LWRs for operation with MOX fuel made from weapons-grade plutonium. The requirements for planning and implementing a test program in the ATR have been identified. The facilities at Argonne National Laboratory-West can meet all potential needs for pre- and post-irradiation examination that might arise in a MOX fuel qualification program

Effect of thermal, chemical and thermo-chemical pre-treatments to enhance methane production

Energy Technology Data Exchange (ETDEWEB)

Rafique, Rashad; Nizami, Abdul-Sattar; Murphy, Jerry D.; Kiely, Gerard [Department of Civil and Environmental Engineering, University College Cork (Ireland); Poulsen, Tjalfe Gorm [Department of Biotechnology, Chemistry and Environmental Engineering, Aalborg University (Denmark); Asam, Zaki-ul-Zaman [Department of Civil Engineering, National University of Ireland Galway (Ireland)

2010-12-15

The rise in oil price triggered the exploration and enhancement of various renewable energy sources. Producing biogas from organic waste is not only providing a clean sustainable indigenous fuel to the number of on-farm digesters in Europe, but also reducing the ecological and environmental deterioration. The lignocellulosic substrates are not completely biodegraded in anaerobic digesters operating at commercial scale due to their complex physical and chemical structure, which result in meager energy recovery in terms of methane yield. The focus of this study is to investigate the effect of pre-treatments: thermal, thermo-chemical and chemical pre-treatments on the biogas and methane potential of dewatered pig manure. A laboratory scale batch digester is used for these pre-treatments at different temperature range (25 C-150 C). Results showed that thermo-chemical pretreatment has high effect on biogas and methane potential in the temperature range (25-100 C). Maximum enhancement is observed at 70 C with increase of 78% biogas and 60% methane production. Thermal pretreatment also showed enhancement in the temperature range (50-10 C), with maximum enhancement at 100 C having 28% biogas and 25% methane increase. (author)

Fuel characteristics pertinent to the design of aircraft fuel systems

Science.gov (United States)

Barnett, Henry C; Hibbard, R R

1953-01-01

Because of the importance of fuel properties in design of aircraft fuel systems the present report has been prepared to provide information on the characteristics of current jet fuels. In addition to information on fuel properties, discussions are presented on fuel specifications, the variations among fuels supplied under a given specification, fuel composition, and the pertinence of fuel composition and physical properties to fuel system design. In some instances the influence of variables such as pressure and temperature on physical properties is indicated. References are cited to provide fuel system designers with sources of information containing more detail than is practicable in the present report.

Crude Glycerol as Cost-Effective Fuel for Combined Heat and Power to Replace Fossil Fuels, Final Technical Report

Energy Technology Data Exchange (ETDEWEB)

Roberts, William L

2012-10-31

The primary objectives of this work can be summed into two major categories. Firstly, the fundamentals of the combustion of glycerol (in both a refined and unrefined form) were to be investigated, with emphasis of the development of a system capable of reliably and repeatedly combusting glycerol as well as an analysis of the emissions produced during glycerol combustion. Focus was placed on quantifying common emissions in comparison to more traditional fuels and this work showed that the burner developed was able to completely combust glycerol within a relatively wide range of operating conditions. Additionally, focus was placed on examining specific emissions in more detail, namely interesting NOx emissions observed in initial trials, acrolein and other volatile organic emissions, and particulate and ash emissions. This work showed that the combustion of crude glycerol could result in significantly reduced NOx emissions as a function of the high fuel bound oxygen content within the glycerol fuel. It also showed that when burned properly, the combustion of crude glycerol did not result in excessive emissions of acrolein or any other VOC compared to the combustion from more traditional fuels. Lastly however, this work has shown that in any practical application in which glycerol is being burned, it will be necessary to explore ash mitigation techniques due to the very high particulate matter concentrations produced during glycerol combustion. These emissions are comparable to unfiltered coal combustion and are directly tied to the biodiesel production method. The second focus of this work was directed to developing a commercialization strategy for the use of glycerol as a fuel replacement. This strategy has identified a 30 month plan for the scaling up of the laboratory scale burner into a pre-pilot scale system. Additionally, financing options were explored and an assessment was made of the economics of replacing a traditional fuel (namely natural gas) with crude

On the nuclear fuel and fossil fuel reserves

International Nuclear Information System (INIS)

Fettweis, G.

1978-01-01

A short discussion of the nuclear fuel and fossil fuel reserves and the connected problem of prices evolution is presented. The need to regard fuel production under an economic aspect is emphasized. Data about known and assessed fuel reserves, world-wide and with special consideration of Austria, are reviewed. It is concluded that in view of the fuel reserves situation an energy policy which allows for a maximum of options seems adequate. (G.G.)

Reestablishing Open Rotor as an Option for Significant Fuel Burn Improvements

Science.gov (United States)

Van Zante, Dale

2011-01-01

A low-noise open rotor system is being tested in collaboration with General Electric and CFM International, a 50/50 joint company between Snecma and GE. Candidate technologies for lower noise will be investigated as well as installation effects such as pylon integration. Current test status is presented as well as future scheduled testing which includes the FAA/CLEEN test entry. Pre-test predictions show that Open Rotors have the potential for revolutionary fuel burn savings.

Control strategy for power management, efficiency-optimization and operating-safety of a 5-kW solid oxide fuel cell system

International Nuclear Information System (INIS)

Zhang, Lin; Jiang, Jianhua; Cheng, Huan; Deng, Zhonghua; Li, Xi

2015-01-01

Highlights: • Efficiency optimization associated with simultaneous power and thermal management. • Fast load tracing, fuel starvation, high efficiency and operating safety are considered. • Open loop pre-conditioning current strategy is proposed for load step-up transients. • Feedback control scheme is proposed for load step-up transients. - Abstract: The slow power tracking, operating safety, especially the fuel exhaustion, and high efficiency considerations are the key issues for integrated solid oxide fuel cell (SOFC) systems during power step up transients, resulting in the relatively poor dynamic capabilities and make the transient load following very challenging and must be enhanced. To this end, this paper first focus on addressing the efficiency optimization associated with simultaneous power and thermal management of a 5-kW SOFC system. Particularly, a traverse optimization process including cubic convolution interpolation algorithm are proposed to obtain optimal operating points (OOPs) with the maximum efficiency. Then this paper investigate the current implications on system step-up transient performance, then a two stage pre-conditioning current strategy and a feedback power reference control scheme is proposed for load step-up transients to balance fast load following and fuel starvation, after that safe thermal transient is validated. Simulation results show the efficacy of the control design by demonstrating the fast load following ability while maintaining the safe operation, thus safe; efficient and fast load transition can be achieved

Il comico come strategia in Gianni Celati & Co

DEFF Research Database (Denmark)

2012-01-01

in danese. Lene Waage Petersen ha organizzato l’incontro di Copenaghen insieme a Pia Schwarz Lausten, con la collaborazione del comitato scientifico composto da Marco Belpoliti, María J. Calvo Montoro e Anna Wegener, che ringraziamo per il loro contributo sostanziale alla realizzazione del convegno...

Pre-symptomatic increase in urine-orosomucoid excretion in pre-eclamptic women

DEFF Research Database (Denmark)

Kronborg, Camilla Skovhus; Allen, Jim; Vittinghus, Erik

2007-01-01

, 32 women developed pre-eclampsia, and 5 controls for every case of pre-eclampsia were found. Blood samples were collected 4 times and urine samples 6 times from the 18/19th week and throughout pregnancy. Orosomucoid and albumin in plasma were analysed by standard methods, and in urine by sandwich...... in orosomucoid. In the plasma samples, orosomucoid was significantly higher late in pre-eclamptic pregnancies (>or=36th week, p=0.0275). CONCLUSIONS: Pre-eclampsia is associated with a pre-symptomatic increase in the urine excretion of orosomucoid, and orosomucoid excretion precedes that of albumin. Orosomucoid...... excretion can probably be used as a prognostic tool in combination with other screening methods, and seems to be a more sensitive marker for evolving pre-eclampsia than albumin. Plasma orosomucoid is significantly increased late in pre-eclampsia. Thus, the increased excretion of orosomucoid must primarily...

Microcontroller based automation system for end plug welding of test fuel pins in solgel facility

International Nuclear Information System (INIS)

Prabhakar Rao, J.; Srinivas, K.C.; Prabhu, T.V.; Ravi, N.

2010-01-01

A microcontroller based stepper motor control and driver Unit for 'XY' positioning system is designed and developed to perform the 'pick-place' of fuel tube to pre-determined coordinates. This Unit provides a fine movement of the fuel tube to get perfect position for welding. The Graphical User Interface software running on PC displays the absolute position of the XY system and provides all the required control buttons to achieve the accurate positioning. The welding of clad tube with end plug is carried out in a high precision welding fixture by operating it remotely. This paper discusses about the Hardware and Software features and implementation of the instrumentation. (author)

Fuel R and D to improve fuel reliability

International Nuclear Information System (INIS)

Yang, Rosa; Cheng, Bo; Deshon, Jeff; Edsinger, Kurt; Ozer, Odelli

2006-01-01

Light water reactor fuel is operating in an increasingly challenging environment. Fuel burnup extension and cycle length increase both can increase the local duty. Reactor water chemistry modifications for the purpose of protection the plant system materials have the potential of increasing fuel surface deposition and cladding corrosion and hydriding. The status of fuel performance in US reactors is summarized and an update of the Fuel Reliability Program' established by the utility industry to ensure reliability is provided. (author)

Instrumentation of fuel elements and fuel plates

International Nuclear Information System (INIS)

Durand, J.P.; Fanjas, Y.

1993-01-01

When controlling the behaviour of a reactor or developing a new fuel concept, it is of utmost interest to have the possibility to confirm the thermohydraulic calculations by actual measurements in the fuel elements or in the fuel plates. For years, CERCA has developed the technology and supplied its customers with fuel elements equipped with pressure or temperature measuring devices according to the requirements. Recent customer projects have led to the development of a new method to introduce thermocouples directly into the fuel plate meat instead of the cladding. The purpose of this paper is to review the various instrumentation possibilities available at CERCA. (author)

Instrumentation of fuel elements and fuel plates

International Nuclear Information System (INIS)

Durand, J.P.; Fanjas, Y.

1994-01-01

When controlling the behaviour of a reactor or developing a new fuel concept, it is of utmost interest to have the possibility to confirm the thermohydraulic calculations by actual measurements in the fuel elements or in the fuel plates. For years, CERCA has developed the technology and supplied its customers with fuel elements equipped with pressure or temperature measuring devices according to the requirements. Recent customer projects have lead to the development of a new method to introduce thermocouples directly into the fuel plate meat instead of the cladding. The purpose of this paper is to review the various instrumentation possibilities available at CERCA. (author)

Solid recovered fuels in the cement industry with special respect to hazardous waste.

Science.gov (United States)

Thomanetz, Erwin

2012-04-01

Cements with good technical properties have been produced in Europe since the nineteenth century and are now worldwide standardized high-quality mass products with enormous production numbers. The basic component for cement is the so-called clinker which is produced mainly from raw meal (limestone plus clay plus sands) in a rotary kiln with preheater and progressively with integrated calciner, at temperatures up to 1450 °C. This process requires large amounts of fossil fuels and is CO₂-intensive. But most CO₂ is released by lime decomposition during the burning process. In the 1980s the use of alternative fuels began--firstly in the form of used oil and waste tyres and then increasingly by pre-conditioned materials from commercial waste and from high calorific industrial waste (i.e. solid recovered fuel (SRF))--as well as organic hazardous waste materials such as solvents, pre-conditioned with sawdust. Therefore the cement industry is more and more a competitor in the waste-to-energy market--be it for municipal waste or for hazardous waste, especially concerning waste incineration, but also for other co-incineration plants. There are still no binding EU rules identifying which types of SRF or hazardous waste could be incinerated in cement kilns, but there are some well-made country-specific 'positive lists', for example in Switzerland and Austria. Thus, for proper planning in the cement industry as well as in the waste management field, waste disposal routes should be considered properly, in order to avoid surplus capacities on one side and shortage on the other.

Alternative Fuels Data Center: Biodiesel Fueling Stations

Science.gov (United States)

Locations Infrastructure Development Vehicles Laws & Incentives Biodiesel Fueling Stations Photo of a location or along a route. Infrastructure Development Learn about biodiesel fueling infrastructure codes Case Studies California Ramps Up Biofuels Infrastructure Green Fueling Station Powers Fleets in Upstate

PreCam

Energy Technology Data Exchange (ETDEWEB)

Allam, Sahar S. [Fermilab; Tucker, Douglas L. [Fermilab

2015-01-01

The Dark Energy Survey (DES) will be taking the next step in probing the properties of Dark Energy and in understanding the physics of cosmic acceleration. A step towards the photometric calibration of DES is to have a quick, bright survey in the DES footprint (PreCam), using a pre-production set of the Dark Energy Camera (DECam) CCDs and a set of 100 mm×100 mm DES filters. The objective of the PreCam Survey is to create a network of calibrated DES grizY standard stars that will be used for DES nightly calibrations and to improve the DES global relative calibrations. Here, we describe the first year of PreCam observation, results, and photometric calibrations.

Fuel assembly

International Nuclear Information System (INIS)

Nomata, Terumitsu.

1993-01-01

Among fuel pellets to be loaded to fuel cans of a fuel assembly, fuel pellets having a small thermal power are charged in a region from the end of each of spacers up to about 50mm on the upstream of coolants that flow vertically at the periphery of fuel rods. Coolants at the periphery of fuel rods are heated by the heat generation, to result in voids. However, since cooling effect on the upstream of the spacers is low due to influences of the spacers. Further, since the fuel pellets disposed in the upstream region have small thermal power, a void coefficient is not increased. Even if a thermal power exceeding cooling performance should be generated, there is no worry of causing burnout in the upstream region. Even if burnout should be caused, safety margin and reliability relative to burnout are improved, to increase an allowable thermal power, thereby enabling to improve integrity and reliability of fuel rods and fuel assemblies. (N.H.)

Fuel assembly

International Nuclear Information System (INIS)

Gjertsen, R.K.; Bassler, E.A.; Huckestein, E.A.; Salton, R.B.; Tower, S.N.

1988-01-01

A fuel assembly adapted for use with a pressurized water nuclear reactor having capabilities for fluid moderator spectral shift control is described comprising: parallel arranged elongated nuclear fuel elements; means for providing for axial support of the fuel elements and for arranging the fuel elements in a spaced array; thimbles interspersed among the fuel elements adapted for insertion of a rod control cluster therewithin; means for structurally joining the fuel elements and the guide thimbles; fluid moderator control means for providing a volume of low neutron absorbing fluid within the fuel assembly and for removing a substantially equivalent volume of reactor coolant water therefrom, a first flow manifold at one end of the fuel assembly sealingly connected to a first end of the moderator control tubes whereby the first ends are commonly flow connected; and a second flow manifold, having an inlet passage and an outlet passage therein, sealingly connected to a second end of the moderator control tubes at a second end of the fuel assembly

Proposal for a project to irradiation of fuel rods in hydraulic rabbit loop of R-2 reactor, Studsvik, Sweden

International Nuclear Information System (INIS)

Almeida, M.R.; Ambrozio, F.; Carvalho, S.R.B.

1974-01-01

It is planning to perform irradiation test on 21 little samples during a short time. These samples are formed by fuel rods covered with zircaloy 4. It contains UO sub(2) natural pellets and UO sub(2) enriched pellets. The type of fuel and the effects of some parameters, such as diametral gap, irradiation time, power liner density, thermal treatment, over the performance of the samples, will be studied. The parameters variations will be measured by pre and post-irradiation tests. Computer codes has been used in order to simulate the samples performance. The safety test performance via those simulations leads to conclusions that irradiation does not cause damage to integrity of the fuel rods. (M.I.)

Alternative Fuels Data Center: Ethanol Fueling Stations

Science.gov (United States)

... More in this section... Ethanol Basics Benefits & Considerations Stations Locations Infrastructure fueling stations by location or along a route. Infrastructure Development Learn about ethanol fueling infrastructure; codes, standards, and safety; and ethanol equipment options. Maps & Data E85 Fueling Station

Effect of Granule Size on Diametric Tolerance of Annular Fuel Pellet

International Nuclear Information System (INIS)

Rhee, Young Woo; Kim, Dong Joo; Kim, Jong Hun; Yang, Jae Ho; Kim, Keon Sik; Kang, Ki Won; Song, Kun Woo

2008-01-01

A dual cooled annular fuel has been seriously considered as a favorable option for an extended power uprate of a Pressurized Water Reactor fuel assembly. An annular fuel shows a lot of advantages from the point of a fuel safety and its economy due to its unique configurational merit such as an increased heat transfer area and a thin pellet thickness. From the viewpoint of the fuel pellet fabrication, however, the unique shape of annular fuel pellet causes challenging difficulties to satisfy a diametric tolerance. A sintered cylindrical PWR fuel pellet fabricated by a conventional double-acting press has an hour-glass shape due to an inhomogeneous green density distribution in a powder compact. Thus, a sintered pellet usually undergoes a centerless grinding process in order to secure diametric tolerance specifications. In the case of an annular pellet fabrication using a conventional double-acting press, the same hour-glass shape would probably occur. An inhomogeneous green density distribution in a powder compact is attributed to granule-granule frictions and granule to pressing mold wall frictions. Frictions result in an irregular pressing load distribution in a powder compact. In order to mitigate the frictions, a lot of process variables should be considered such as pre-compaction pressure, lubricant content, granule size and compaction pressure. The purpose of this study is to investigate the effect of a granule size on the amount of deformation after sintering, in other words, the amount of an hour-glassing. The granules with classified size ranges were made to green annular pellets with the same height and diameters. The hour-glassing amounts of the sintered annular pellets were measured and compared with that of the annular pellet made by unclassified granule

Apparatus and method for grounding compressed fuel fueling operator

Science.gov (United States)

Cohen, Joseph Perry; Farese, David John; Xu, Jianguo

2002-06-11

A safety system for grounding an operator at a fueling station prior to removing a fuel fill nozzle from a fuel tank upon completion of a fuel filling operation is provided which includes a fuel tank port in communication with the fuel tank for receiving and retaining the nozzle during the fuel filling operation and a grounding device adjacent to the fuel tank port which includes a grounding switch having a contact member that receives physical contact by the operator and where physical contact of the contact member activates the grounding switch. A releasable interlock is included that provides a lock position wherein the nozzle is locked into the port upon insertion of the nozzle into the port and a release position wherein the nozzle is releasable from the port upon completion of the fuel filling operation and after physical contact of the contact member is accomplished.

Nuclear fuel

International Nuclear Information System (INIS)

D Hondt, P.

1998-01-01

The research and development programme on nuclear fuel at the Belgian Nuclear Research Centre SCK/CEN is described. The objective of this programme is to enhance the quantitative prediction of the operational limits of nuclear fuel and to assess the behaviour of fuel under incidental and accidental conditions. Progress is described in different domains including the modelling of fission gas release in LWR fuel, thermal conductivity, basic physical phenomena, post-irradiation examination for fuel performance assessment, and conceptual studies of incidental and accidental fuel experiments

Automotive Fuel Processor Development and Demonstration with Fuel Cell Systems

Energy Technology Data Exchange (ETDEWEB)

Nuvera Fuel Cells

2005-04-15

The potential for fuel cell systems to improve energy efficiency and reduce emissions over conventional power systems has generated significant interest in fuel cell technologies. While fuel cells are being investigated for use in many applications such as stationary power generation and small portable devices, transportation applications present some unique challenges for fuel cell technology. Due to their lower operating temperature and non-brittle materials, most transportation work is focusing on fuel cells using proton exchange membrane (PEM) technology. Since PEM fuel cells are fueled by hydrogen, major obstacles to their widespread use are the lack of an available hydrogen fueling infrastructure and hydrogen's relatively low energy storage density, which leads to a much lower driving range than conventional vehicles. One potential solution to the hydrogen infrastructure and storage density issues is to convert a conventional fuel such as gasoline into hydrogen onboard the vehicle using a fuel processor. Figure 2 shows that gasoline stores roughly 7 times more energy per volume than pressurized hydrogen gas at 700 bar and 4 times more than liquid hydrogen. If integrated properly, the fuel processor/fuel cell system would also be more efficient than traditional engines and would give a fuel economy benefit while hydrogen storage and distribution issues are being investigated. Widespread implementation of fuel processor/fuel cell systems requires improvements in several aspects of the technology, including size, startup time, transient response time, and cost. In addition, the ability to operate on a number of hydrocarbon fuels that are available through the existing infrastructure is a key enabler for commercializing these systems. In this program, Nuvera Fuel Cells collaborated with the Department of Energy (DOE) to develop efficient, low-emission, multi-fuel processors for transportation applications. Nuvera's focus was on (1) developing fuel

Demonstration test of the spent fuel rod cutting process with tube cutter mechanism

International Nuclear Information System (INIS)

Lee, Jong Youl; Jung, Jae Hoo; Hong, Dong Hee; Yoon, Ji Sup; Lee, Eun Pyo

2001-03-01

In this paper, the verification by computer graphics technology for the spent fuel rod cutting devise which belongs to the spent fuel disassembly processes, the performance tests of the real device, and the demonstration tests with tube cutter mechanism are described. The graphical design system is used throughout the design stages from conceptual design to motion analysis like collision detection. By using this system, the device and the process are optimized. The performance test of the real device and the demonstration test using the tube cutter mechanism in the hot cell are carried out. From these results, the spent fuel rod cutting device is improved based on the considerations of circularity of the rod cross-section, debris generation, and fire risk etc. Also, this device is improved to be operated automatically via remote control system considering later use in closed environment like Hot-cell (radioactive area) and the modulization in the structure of this device makes maintenance easy. The result of the performance test and the demonstration in this report is expected to contribute to the optimization of the pre-treatment processes for the reuse of the spent fuel like DUPIC process and the final disposal

Fluid pressure method for recovering fuel pellets from nuclear fuel elements

International Nuclear Information System (INIS)

John, C.D. Jr.

1979-01-01

A method is described for removing fuel pellets from a nuclear fuel element without damaging the fuel pellets or fuel element sheath so that both may be reused. The method comprises holding the fuel element while a high pressure stream internally pressurizes the fuel element to expand the fuel element sheath away from the fuel pellets therein so that the fuel pellets may be easily removed

Nuclear Fuel elements

International Nuclear Information System (INIS)

Hirakawa, Hiromasa.

1979-01-01

Purpose: To reduce the stress gradient resulted in the fuel can in fuel rods adapted to control the axial power distribution by the combination of fuel pellets having different linear power densities. Constitution: In a fuel rod comprising a first fuel pellet of a relatively low linear power density and a second fuel pellet of a relatively high linear power density, the second fuel pellet is cut at its both end faces by an amount corresponding to the heat expansion of the pellet due to the difference in the linear power density to the adjacent first fuel pellet. Thus, the second fuel pellet takes a smaller space than the first fuel pellet in the fuel can. This can reduce the stress produced in the portion of the fuel can corresponding to the boundary between the adjacent fuel pellets. (Kawakami, Y.)

The Cooney Ridge Fire Experiment: An early operation to relate pre-, active, and post-fire field and remotely sensed measurements

Science.gov (United States)

Andrew T. Hudak; Patrick H. Freeborn; Sarah A. Lewis; Sharon M. Hood; Helen Y. Smith; Colin C. Hardy; Robert J. Kremens; Bret W. Butler; Casey Teske; Robert G. Tissell; Lloyd P. Queen; Bryce L. Nordgren; Benjamin C. Bright; Penelope Morgan; Philip J. Riggan; Lee Macholz; Leigh B. Lentile; James P. Riddering; Edward E. Mathews

2018-01-01

The Cooney Ridge Fire Experiment conducted by fire scientists in 2003 was a burnout operation supported by a fire suppression crew on the active Cooney Ridge wildfire incident. The fire experiment included measurements of pre-fire fuels, active fire behavior, and immediate post-fire effects. Heat flux measurements collected at multiple scales with multiple ground and...

77 FR 61313 - Regulation of Fuels and Fuel Additives: Modifications to Renewable Fuel Standard and Diesel...

Science.gov (United States)

2012-10-09

... transportation fuels, including gasoline and diesel fuel, or renewable fuels such as ethanol and biodiesel, as... that which arose under RFS1 for certain renewable fuels (in particular biodiesel) that were produced...

Fuel assembly

International Nuclear Information System (INIS)

Fujibayashi, Toru.

1970-01-01

Herein disclosed is a fuel assembly in which a fuel rod bundle is easily detachable by rotating a fuel rod fastener rotatably mounted to the upper surface of an upper tie-plate supporting a fuel bundle therebelow. A locking portion at the leading end of each fuel rod protrudes through the upper tie-plate and is engaged with or separated from the tie-plate by the rotation of the fastener. The removal of a desired fuel rod can therefore be remotely accomplished without the necessity of handling pawls, locking washers and nuts. (Owens, K.J.)

75 FR 14669 - Regulation of Fuels and Fuel Additives: Changes to Renewable Fuel Standard Program

Science.gov (United States)

2010-03-26

... RINs from producers of the renewable fuel. The obligated parties do not need lead time for construction... fuels and new limits on renewable biomass feedstocks. This rulemaking marks the first time that... advanced biofuel and multiple cellulosic-based fuels with their 60% threshold. Additional fuel pathways...

Fuel property effects on Navy aircraft fuel systems

Science.gov (United States)

Moses, C. A.

1984-01-01

Problems of ensuring compatibility of Navy aircraft with fuels that may be different than the fuels for which the equipment was designed and qualified are discussed. To avoid expensive requalification of all the engines and airframe fuel systems, methodologies to qualify future fuels by using bench-scale and component testing are being sought. Fuel blends with increasing JP5-type aromatic concentration were seen to produce less volume swell than an equivalent aromatic concentration in the reference fuel. Futhermore, blends with naphthenes, decalin, tetralin, and naphthalenes do not deviate significantly from the correlation line of aromatic blends, Similar results are found with tensile strenth and elongation. Other elastomers, sealants, and adhesives are also being tested.

Characterization of fuel swelling in helium-bonded carbide fuel pins

International Nuclear Information System (INIS)

Louie, D.L.Y.

1987-08-01

This work is not only the first attempt at characterizing the swelling of (U,Pu)C fuel pellets, but it also represents the only detailed examinations on carbide fuel swelling at high fuel burnups (4 to 16 at. %). This characterization includes the contributions of fission gases, cracks and solid fission products to fuel swelling. Significantly, the contributions of fission gases and cracks were determined by using the image analysis technique (IAT) which allows researchers to take areal measurements of the irradiated fuel porosity and cracks from the photographs of metallographic fuel samples. However, because areal measurements for varying depths in the fuel pellet could not be obtained, the crack areal measurements could not be converted into volumetric quantities. Consequently, in this situation, an areal fuel swelling analysis was used. The macroscopic fission-gas induced fuel swelling (MAS) caused by fission-gas bubbles and pores > 1 μm was determined using the measured irradiated fuel porosity because the measuring range of IAT is limited to bubbles and pores >1 μm. Conversely, for fuel swelling induced by fission-gas bubbles < 1 μm, the microscopic fission-gas induced fuel swelling (MIS) was estimated using an areal fuel swelling model

Automation of FBTR fuel pin inspection using FPGA

International Nuclear Information System (INIS)

Khare, K.M.; Pai, Siddhesh; Pant, Brijesh; Sendhil Raja, S.; Gupta, P.K.

2011-01-01

A non-contact metrology system for inspection of FBTR fuel pins has been developed. The system consists of a stepper motors driven mechanism for orientation and positioning of FBTR fuel pin, a telecentric imaging system, absolute linear encoder with 0.1 μm resolution and a Field Programmable Gate Array (FPCA) based controller. The FBTR pin assembly is telecentrically illuminated from bottom by a red LED and its shadow graph is imaged using a CCD camera through telecentric imaging lens system. For system control and automation we have used a FPGA that has integrated soft picoblaze processor, X-θ axis motion controller, custom IPs for encoder data acquisition, synchronization circuit, RS485 interface along with other l/Os. Using the Graphical User Interface (GUI) on a PC the system is initialized at home position and the controller provides the trigger signal for start of data acquisition of CCD camera. CCD image of pin and the corresponding X-θ information is captured. After the acquisition of one set of images, the imaging module is moved with a step size pre-programmed to ensure proper stitching of acquired images. The GUI is programmed to analyze these X-θ Images to calculate the required parameters of the fuel pin like the diameter variation, pitch and bow. The details of the instrument and measurements made with it will be presented. (author)

KMRR fuel design