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Sample records for fuel pellet inspection

  1. Automated fuel pellet inspection system

    NASA Astrophysics Data System (ADS)

    Lichauer, John C.; Zana, Larry J.

    1992-11-01

    In the nuclear fuels industry, a great deal of effort goes into ensuring that quality materials are produced. Of these materials, none receives more attention than the uranium-oxide nuclear fuel pellets. These cylindrically shaped pellets (approx. 1/2 inch L X 1/2 inch D) are carefully produced and then meticulously inspected for various defects (e.g., cracks, chips, etc.). The inspection process is designed to remove any defective pellets from each lot, assuring the end user a reliable, predictable, and safe product. The current (manual) inspection process is laborious and subjective in nature. The inspector also receives prolonged exposure to low-level radiation. For these reasons, automated inspection of nuclear fuel pellets has long been a goal of the industry. However, it is not a simple task, due to the many material handling and image processing challenges required to inspect pellets at production rates (greater than five per second). This paper describes an automated nuclear fuel pellet inspection system that has successfully met these challenges. Built around a set of modular, high-speed, pipelined image processing hardware, it inspects pellets at rates of up to seven pellets per second. Recent tests have shown better than 97% detection rates with less than 2% false reject rates. Image processing algorithms and solutions to design challenges are described.

  2. Automatic inspection system for nuclear fuel pellets or rods

    DOEpatents

    Miller, Jr., William H.; Sease, John D.; Hamel, William R.; Bradley, Ronnie A.

    1978-01-01

    An automatic inspection system is provided for determining surface defects on cylindrical objects such as nuclear fuel pellets or rods. The active element of the system is a compound ring having a plurality of pneumatic jet units directed into a central bore. These jet units are connected to provide multiple circuits, each circuit being provided with a pressure sensor. The outputs of the sensors are fed to a comparator circuit whereby a signal is generated when the difference of pressure between pneumatic circuits, caused by a defect, exceeds a pre-set amount. This signal may be used to divert the piece being inspected into a "reject" storage bin or the like.

  3. Pellet inspection apparatus

    DOEpatents

    Wilks, Robert S.; Taleff, Alexander; Sturges, Jr., Robert H.

    1982-01-01

    Apparatus for inspecting nuclear fuel pellets in a sealed container for diameter, flaws, length and weight. The apparatus includes, in an array, a pellet pick-up station, four pellet inspection stations and a pellet sorting station. The pellets are delivered one at a time to the pick-up station by a vibrating bowl through a vibrating linear conveyor. Grippers each associated with a successive pair of the stations are reciprocable together to pick up a pellet at the upstream station of each pair and to deposit the pellet at the corresponding downstream station. The gripper jaws are opened selectively depending on the state of the pellets at the stations and the particular cycle in which the apparatus is operating. Inspection for diameter, flaws and length is effected in each case by a laser beam projected on the pellets by a precise optical system while each pellet is rotated by rollers. Each laser and its optical system are mounted in a container which is free standing on a precise surface and is provided with locating buttons which engage locating holes in the surface so that each laser and its optical system is precisely set. The roller stands are likewise free standing and are similarly precisely positioned. The diameter optical system projects a thin beam of light which scans across the top of each pellet and is projected on a diode array. The fl GOVERNMENT CONTRACT CLAUSE The invention herein described was made in the course of or under a contract or subcontract thereunder with the Department of Energy bearing No. EY-67-14-C-2170.

  4. ORNL centrifuge pellet fueling system

    SciTech Connect

    Foster, C.A.; Houlberg, W.A.; Gouge, M.J.; Grapperhaus, M.J.; Milora, S.L. ); Drawin, H.; Geraud, A.; Chatelier, M.; Gros, G. )

    1992-01-01

    A centrifuge pellet injecter designed and built at Oak Ridge National Laboratory (ORNL) is in operation on Tore Supra. This injector has the capability of injecting up to 100 pellets at speeds up to 800 M/s. The solid deuterium pellets can be formed with a variable mass from 3 to 10 torr-L and are fired at a rate of up to 10 pellets per second. The experimental program that is under way combines repetitive pellet fueling with the ergodic divertor and pump limiters to establish and understand long-pulse plasmas in which the pellet fuel source is in balance with the particle exhaust. With lower hybrid current drive, pulse lengths of up to 2 min might be achieved. To prepare for these extended pulse lengths, the pellet source on the centrifuge will be extended to provide a 300- to 500-pellet capability. A similar system extended to steady-state pellet fabrication technology and designed for a radiation and tritium environment would be a candidate for a fueling system for the International Thermonuclear Experimental Reactor (ITER). Analysis of pellet-fueled ITER discharges using the WHIST code shows the potential for controlling the radial fuel deposition point to achieve the desired core density while maintaining the edge density and temperatures so as to minimize the diverter plate erosion. A centrifuge fueling system would have the capability of taking the D-T exhaust directly from the cryopumping systems, recondensing and purifying the fuel, and injecting the reconstituted pellets into the plasma, thereby minimizing the tritium inventory.

  5. ORNL centrifuge pellet fueling system

    SciTech Connect

    Foster, C.A.; Houlberg, W.A.; Gouge, M.J.; Grapperhaus, M.J.; Milora, S.L.; Drawin, H.; Geraud, A.; Chatelier, M.; Gros, G.

    1992-11-01

    A centrifuge pellet injecter designed and built at Oak Ridge National Laboratory (ORNL) is in operation on Tore Supra. This injector has the capability of injecting up to 100 pellets at speeds up to 800 M/s. The solid deuterium pellets can be formed with a variable mass from 3 to 10 torr-L and are fired at a rate of up to 10 pellets per second. The experimental program that is under way combines repetitive pellet fueling with the ergodic divertor and pump limiters to establish and understand long-pulse plasmas in which the pellet fuel source is in balance with the particle exhaust. With lower hybrid current drive, pulse lengths of up to 2 min might be achieved. To prepare for these extended pulse lengths, the pellet source on the centrifuge will be extended to provide a 300- to 500-pellet capability. A similar system extended to steady-state pellet fabrication technology and designed for a radiation and tritium environment would be a candidate for a fueling system for the International Thermonuclear Experimental Reactor (ITER). Analysis of pellet-fueled ITER discharges using the WHIST code shows the potential for controlling the radial fuel deposition point to achieve the desired core density while maintaining the edge density and temperatures so as to minimize the diverter plate erosion. A centrifuge fueling system would have the capability of taking the D-T exhaust directly from the cryopumping systems, recondensing and purifying the fuel, and injecting the reconstituted pellets into the plasma, thereby minimizing the tritium inventory.

  6. Nuclear fuel pellet quality control using artificial intelligence techniques

    NASA Astrophysics Data System (ADS)

    Song, Xiaolong

    Inspection of nuclear fuel pellets is a complex and time-consuming process. At present, quality control in the fuel fabrication field mainly relies on human manual inspection, which is essentially a judgement call. Considering the high quality requirement of fuel pellets in the nuclear industry, pellet inspection systems must have a high accuracy rate in addition to a high inspection speed. Furthermore, any inspection process should have a low rejection rate of good pellets from the manufacturer point of view. It is very difficult to use traditional techniques, such as simple image comparison, to adequately perform the inspection process of the nuclear fuel pellet. Knowledge-based inspection and a defect-recognition algorithm, which maps the human inspection knowledge, is more robust and effective. A novel method is introduced here for pellet image processing. Three artificial intelligence techniques are studied and applied for fuel pellet inspection in this research. They are an artificial neural network, fuzzy logic, and the decision tree method. A dynamic reference model is located on each input fuel pellet image. Then, those pixels that belong to the abnormal defect are enhanced with high speed and high accuracy. Next, the content-based features for the defect are extracted from those abno1mal pixels and used in the inspection algorithm. Finally, an automated inspection prototype system---Visual Inspection Studio---which combines machine vision and these three AI techniques, is developed and tested. The experimental results indicate a very successful system with a high potential for on-line automatic inspection process.

  7. Nuclear fuel pellet transfer escalator

    SciTech Connect

    Huggins, T.B. Sr.; Roberts, E.; Edmunds, M.O.

    1991-09-17

    This patent describes a nuclear fuel pellet escalator for loading nuclear fuel pellets into a sintering boat. It comprises a generally horizontally-disposed pellet transfer conveyor for moving pellets in single file fashion from a receiving end to a discharge end thereof, the conveyor being mounted about an axis at its receiving end for pivotal movement to generally vertically move its discharge end toward and away from a sintering boat when placed below the discharge end of the conveyor, the conveyor including an elongated arm swingable vertically about the axis and having an elongated channel recessed below an upper side of the arm and extending between the receiving and discharge ends of the conveyor; a pellet dispensing chute mounted to the arm of the conveyor at the discharge end thereof and extending therebelow such that the chute is carried at the discharge end of the conveyor for generally vertical movement therewith toward and away from the sintering boat.

  8. Apparatus and method for classifying fuel pellets for nuclear reactor

    DOEpatents

    Wilks, Robert S.; Sternheim, Eliezer; Breakey, Gerald A.; Sturges, Jr., Robert H.; Taleff, Alexander; Castner, Raymond P.

    1984-01-01

    Control for the operation of a mechanical handling and gauging system for nuclear fuel pellets. The pellets are inspected for diameters, lengths, surface flaws and weights in successive stations. The control includes, a computer for commanding the operation of the system and its electronics and for storing and processing the complex data derived at the required high rate. In measuring the diameter, the computer enables the measurement of a calibration pellet, stores that calibration data and computes and stores diameter-correction factors and their addresses along a pellet. To each diameter measurement a correction factor is applied at the appropriate address. The computer commands verification that all critical parts of the system and control are set for inspection and that each pellet is positioned for inspection. During each cycle of inspection, the measurement operation proceeds normally irrespective of whether or not a pellet is present in each station. If a pellet is not positioned in a station, a measurement is recorded, but the recorded measurement indicates maloperation. In measuring diameter and length a light pattern including successive shadows of slices transverse for diameter or longitudinal for length are projected on a photodiode array. The light pattern is scanned electronically by a train of pulses. The pulses are counted during the scan of the lighted diodes. For evaluation of diameter the maximum diameter count and the number of slices for which the diameter exceeds a predetermined minimum is determined. For acceptance, the maximum must be less than a maximum level and the minimum must exceed a set number. For evaluation of length, the maximum length is determined. For acceptance, the length must be within maximum and minimum limits.

  9. Apparatus for feeding nuclear fuel pellets to a loading tray

    SciTech Connect

    Huggins, T.B.

    1981-12-08

    Apparatus for feeding nuclear fuel pellets at a uniform, predetermined rate between pellet centering and grinding apparatus and a tray used for loading pellets into a nuclear fuel rod are described. Pellets discharged from the grinder are conveyed by a woven wire belt to a drive wheel which develops a force available to be applied to pellets preceding it on the belt. The pellets pass under the drive wheel which adds additional weight acting vertically on each pellet. This total weight of pellet and drive wheel coupled with wire belt linear movement acts to push a line of about 36 pellets onto a pellet dumping mechanism. As the dumping mechanism is actuated to dump the pellets on to a loading tray, the pellets moving toward the mechanism are clamped in a stationary position and the drive wheel simultaneously is lifted from its pellet contacting position until the pellet dumping process is completed. The clamping device is then lifted from its pellet and the drive wheel simultaneously is lowered into a pellet contacting position.

  10. Fabrication of high exposure nuclear fuel pellets

    DOEpatents

    Frederickson, James R.

    1987-01-01

    A method is disclosed for making a fuel pellet for a nuclear reactor. A mixture is prepared of PuO.sub.2 and UO.sub.2 powders, where the mixture contains at least about 30% PuO.sub.2, and where at least about 12% of the Pu is the Pu.sup.240 isotope. To this mixture is added about 0.3 to about 5% of a binder having a melting point of at least about 250.degree. F. The mixture is pressed to form a slug and the slug is granulated. Up to about 4.7% of a lubricant having a melting point of at least about 330.degree. F. is added to the granulated slug. Both the binder and the lubricant are selected from a group consisting of polyvinyl carboxylate, polyvinyl alcohol, naturally occurring high molecular weight cellulosic polymers, chemically modified high molecular weight cellulosic polymers, and mixtures thereof. The mixture is pressed to form a pellet and the pellet is sintered.

  11. Modeling of MOX Fuel Pellet-Clad Interaction Using ABAQUS

    SciTech Connect

    Ambrosek, Richard G.; Pedersen, Robert C.; Maple, Amanda

    2002-07-01

    Post-irradiation examination (PIE) has indicated an increase in the outer diameter of fuel pins being irradiated in the Advanced Test Reactor (ATR) for the MOX irradiation program. The diameter increase is the largest in the region between fuel pellets. The fuel pellet was modeled using PATRAN and the model was evaluated using ABAQUS, version 6.2. The results from the analysis indicate the non-uniform clad diameter is caused by interaction between the fuel pellet and the clad. The results also demonstrate that the interaction is not uniform over the pellet axial length, with the largest interaction occurring in the region of the pellet-pellet interface. Results were obtained for an axisymmetric model and for a 1/8 pie shaped segment, using the coupled temperature-displacement solution technique. (authors)

  12. Pellet fueling development at Oak Ridge National Laboratory

    SciTech Connect

    Foster, C.A.; Milora, S.L.; Schuresko, D.D.; Combs, S.K.; Lunsford, R.V.

    1982-01-01

    A pellet injector development program has been under way at the Oak Ridge National Laboratory (ORNL) since 1976 with the goals of developing D/sub 2/, T/sub 2/ pellet fuel injectors capable of reliable repetitive fueling of reactors and of continued experimentation on contemporary plasma devices. The development has focused primarily on two types of injectors that show promise. One of these injectors is the centrifuge-type injector, which accelerates pellets in a high speed rotating track. The other is the gas or pneumatic gun, which accelerates pellets in a gun barrel using compressed helium of H/sub 2/ gas.

  13. Straw pellets as fuel in biomass combustion units

    SciTech Connect

    Andreasen, P.; Larsen, M.G.

    1996-12-31

    In order to estimate the suitability of straw pellets as fuel in small combustion units, the Danish Technological Institute accomplished a project including a number of combustion tests in the energy laboratory. The project was part of the effort to reduce the use of fuel oil. The aim of the project was primarily to test straw pellets in small combustion units, including the following: ash/slag conditions when burning straw pellets; emission conditions; other operational consequences; and necessary work performance when using straw pellets. Five types of straw and wood pellets made with different binders and antislag agents were tested as fuel in five different types of boilers in test firings at 50% and 100% nominal boiler output.

  14. A fuel pellet injector for the Microwave Tokamak Experiment (MTX)

    SciTech Connect

    Hibbs, S.M.; Allen, S.L.; Petersen, D.E.; Sewall, N.R.

    1990-09-01

    Unlike other fueling systems for magnetically confined fusion plasmas, a pellet injector can deliver many fuel gas particles to the core of the plasma, enhancing plasma confinement. We installed a new pellet injector on the MTX (formerly Alcator-O) to provide a plasma with a high core density for experiments both with and without ultrahigh-power microwave heating. Its four-barrel pellet generator is the first to be designed and built at LLNL. Based on pipe-gun'' technology originated at Oak Ridge National Laboratory (ORNL), it incorporates our structural and thermal engineering innovations and a unique control system. The pellet transport, differential vacuum-pumping stages, and fast-opening propellant valves are reused parts of the Impurity Study EXperiment (ISX) pellet injector built by ORNL. We tailored designs of all other systems and components to the MTX. Our injector launches pellets of frozen hydrogen or deuterium into the MTX, either singly or in timed bursts of up to four pellets at velocities of up to 1000 m/s. Pellet diameters range from 1.02 to 2.08 mm. A diagnostic stage measures pellet velocities and allows us to photograph the pellets in flight. We are striving to improve the injector's performance, but its operations is already very consistent and reliable.

  15. Fuel pins with both target and fuel pellets in an isotope-production reactor

    DOEpatents

    Cawley, W.E.; Omberg, R.P.

    1982-08-19

    A method is described for producing tritium in a fast breeder reactor cooled with liquid metal. Lithium target pellets are placed in close contact with fissile fuel pellets in order to increase the tritium production rate.

  16. Calculation of density profiles in tandem mirrors fueled by pellets

    SciTech Connect

    Campbell, R.B.; Gilmore, J.M.

    1983-12-02

    We have modified the LLNL radial transport code TMT to model reactor regime plasmas, fueled by pellets. The source profiles arising from pellet fueling are obtained from existing pellet ablation models. Because inward radial diffusion due to inverted profiles must compete with trapping of central cell ions in the transition region for tandem mirrors, pellets must penetrate fairly far into the plasma. In fact, based on our radial calculations, a pellet with a velocity of 10 km/sec cannot sustain the central flux tubes; a velocity more like 100 km/sec will be necessary. We also find that the central cell radial diffusion must exceed classical by about a factor of 100.

  17. Apparatus for inspecting fuel elements

    DOEpatents

    Oakley, David J.; Groves, Oliver J.; Kaiser, Bruce J.

    1986-01-01

    Disclosed is an alpha monitor usable in an automated nuclear fuel pin loading and processing unit. Fuel pins or other elongated pins are fed laterally into the alpha monitor in a singular fashion and are translated by a first roller assembly into a weld flare machining and decontamination substation not forming a part of the invention. Pins return and are lifted upwardly and transferred across to a combined pin lifting and electrode operating means which lifts the pins upwardly into a clamshell electrode assembly which is spread open by a combined pin lifting and electrode operating means. Once inserted the clamshell type electrode arrangement closes around the fuel pins so that inspection can occur. Fuel pins are inspected by charging electrodes to a negative potential and measuring the change in charge occurring when positively charged alpha particles strike the negatively charged electrodes. After inspection, the fuel pins are lowered by the pin lifting and electrode operating means into a second roller assembly which longitudinally conveys approved pins from the airtight enclosure in which the alpha monitor is mounted. If the fuel pins are rejected then they are moved laterally by a second transfer means and onto another system for further processing.

  18. Apparatus for inspecting fuel elements

    DOEpatents

    Kaiser, B.J.; Oakley, D.J.; Groves, O.J.

    1984-12-21

    This disclosure describes an alpha monitor usable in an automated nuclear fuel pin loading and processing unit. Fuel pins or other elongated pins are fed laterally into the alpha monitor in a singular fashion and are translated by a first roller assembly into a weld flare machining and decontamination substation not forming a part of the invention. Pins return and are lifted upwardly and transferred across to a combined pin lifting and electrode operating means which lifts the pins upwardly into a clamshell electrode assembly which is spread open by a combined pin lifting and electrode operating means. Once inserted the clamshell type electrode arrangement closes around the fuel pins so that inspection can occur. Fuel pins are inspected by charging electrodes to a negative potential and measuring the change in charge occurring when positively charged alpha particles strike the negatively charged electrodes. After inspection, the fuel pins are lowered by the pin lifting and electrode operating means into a second roller assembly which longitudinally conveys approved pins from the airtight enclosure in which the alpha monitor is mounted. If the fuel pins are rejected then they are moved laterally by a second transfer means and onto another system for further processing.

  19. Studies on Pellet Fueling of ITER-Like Plasmas

    SciTech Connect

    Kamelander, Gerald; Weimann, Geert; Garzotti, Luca; Litaudon, Xavier; Moreau, Didier; Pegourie, Bernard

    2004-06-15

    The paper reports on simulation of pellet-fueled plasmas in a fusion reactor. The simulations have been performed by means of the ASTRA transport code. We have studied physical modeling of pellet injection as well as the numerical conditions to resolve pellet injection correctly. As a first step the essential mechanisms for density control have been studied based on simplified assumptions with a generic source of additional heating. The experience gained has been used to simulate advanced scenarios including internal transport barriers. It has been confirmed that it is possible to drive the plasma of a next-generation tokamak into a high-Q regime and to maintain it in a steady-state regime. Nevertheless, the pellet injection parameters required are rather demanding and imply a significant technological improvement of pellet injectors. Those investigations represent an improvement of simulations done earlier with a control of the central density at constant profile.

  20. A Compact Flexible Pellet Injection System for Fueling Studies

    NASA Astrophysics Data System (ADS)

    Baylor, L. R.; Combs, S. K.; Fehling, D. T.; Fisher, P. W.; Foust, C. R.; Gouge, M. J.; Rasmussen, D. A.

    2000-10-01

    A compact pellet injection system is being designed and built at ORNL to provide a flexible pellet fueling system for studies in magnetic confinement fusion devices. The system known as a ``pellet injector in a suitcase (PIS)'' is a pipe gun device with four barrels that uses a cryocooler for in-situ hydrogenic pellet formation. The system is being built to provide a flexible, low-cost fueling system that can be used on a number of plasma confinement experiments with minimal installation and operation costs. components in the system. It will use both propellant gas and a mechanical punch to accelerate the 1 - 4 mm size pellets to 100-1500 m/s. With the mechanical punch alone a low speed pellet, useful for curved guide tube applications, can be produced with minimal gas load eliminating the need for a large ballast volume. can be independently fired. diagnose the injector. The PIS is a flexible tool for fueling alternative concept devices such as MST and NSTX and for specialized studies in mainline tokamak experiments such as DIII-D and JET. The small size makes installation on such devices more feasible. of the system design and the expected performance will be presented.

  1. Pellet fueling technology development leading to efficient fueling of ITER burning plasmas

    SciTech Connect

    Baylor, L.R.; Combs, S.K.; Jernigan, T.C.; Houlberg, W.A.; Owen, L.W.; Rasmussen, D.A.; Maruyama, S.; Parks, P.B.

    2005-05-15

    Pellet injection is the primary fueling technique planned for core fueling of ITER [ITER Technical Basis 2002 ITER EDA Documentation Series (Vienna: IAEA)] burning plasmas. Efficient core plasma fueling with deuterium and tritium D-T is a requirement for achieving high fusion gain and it cannot be achieved with gas fueling. Injection of pellets from the inner wall has been shown on present day tokamaks to provide efficient fueling and is planned for use on ITER. Modeling of the fueling deposition from inner wall pellet injection using the Parks ExB drift model indicates that pellets have the capability to fuel well inside the separatrix. Gas fueling calculations show very poor neutral penetration due to the high density and wide scrape off layer. Isotopically mixed D-T pellets can provide efficient tritium fueling that will minimize tritium wall loading when compared to gas puffing. Currently the performance of the ITER inner wall guide tube design is under test with initial results indicating that pellet speeds in excess of 300 m/s will lead to fragmented pellets. The ITER pellet injection technology requirements and remaining development issues are discussed along with a plan to reach the design goal for employment on ITER.

  2. Fuel Pellets from Wheat Straw: The Effect of Lignin Glass Transition and Surface Waxes on Pelletizing Properties

    Treesearch

    Wolfgang Stelte; Craig Clemons; Jens K. Holm; Jesper Ahrenfeldt; Ulrik B. Henriksen; Anand R. Sanadi

    2012-01-01

    The utilization of wheat straw as a renewable energy resource is limited due to its low bulk density. Pelletizing wheat straw into fuel pellets of high density increases its handling properties but is more challenging compared to pelletizing wood biomass. Straw has a lower lignin content and a high concentration of hydrophobic waxes on its outer surface that may limit...

  3. On the Ablation Models of Fuel Pellets

    SciTech Connect

    Rozhansky, V.A.; Senichenkov, I.Yu.

    2005-12-15

    The neutral gas shielding model and neutral-gas-plasma shielding model are analyzed qualitatively. The main physical processes that govern the formation of the shielding gas cloud and, consequently, the ablation rate are considered. For the neutral gas shielding model, simple formulas relating the ablation rate and cloud parameters to the parameters of the pellet and the background plasma are presented. The estimates of the efficiency of neutral gas shielding and plasma shielding are compared. It is shown that the main portion of the energy flux of the background electrons is released in the plasma cloud. Formulas for the ablation rate and plasma parameters are derived in the neutral-gas-plasma shielding model. The question is discussed as to why the neutral gas shielding model describes well the ablation rate of the pellet material, although it does not take into account the ionization effects and the effects associated with the interaction of ionized particles with the magnetic field. The reason is that the ablation rate depends weakly on the energy flux of hot electrons; as a result, the attenuation of this flux by the electrostatic shielding and plasma shielding has little effect on the ablation rate. This justifies the use of the neutral gas shielding model to estimate the ablation rate (to within a factor of about 2) over a wide range of parameters of the pellet and the background plasma.

  4. Dangerous (toxic) atmospheres in UK wood pellet and wood chip fuel storage.

    PubMed

    Simpson, Andrew T; Hemingway, Michael A; Seymour, Cliff

    2016-09-01

    There is growing use of wood pellet and wood chip boilers in the UK. Elsewhere fatalities have been reported, caused by carbon monoxide poisoning following entry into wood pellet storage areas. The aim of this work was to obtain information on how safely these two fuels are being stored in the UK. Site visits were made to six small-scale boiler systems and one large-scale pellet warehouse, to assess storage practice, risk management systems and controls, user knowledge, and potential for exposure to dangerous atmospheres. Real time measurements were made of gases in the store rooms and during laboratory tests on pellets and chips. Volatile organic compounds (VOCs) emitted and the microbiological content of the fuel was also determined. Knowledge of the hazards associated with these fuels, including confined space entry, was found to be limited at the smaller sites, but greater at the large pellet warehouse. There has been limited risk communication between companies supplying and maintaining boilers, those manufacturing and supplying fuel, and users. Risk is controlled by restricting access to the store rooms with locked entries; some store rooms have warning signs and carbon monoxide alarms. Nevertheless, some store rooms are accessed for inspection and maintenance. Laboratory tests showed that potentially dangerous atmospheres of carbon monoxide and carbon dioxide, with depleted levels of oxygen may be generated by these fuels, but this was not observed at the sites visited. Unplanned ventilation within store rooms was thought to be reducing the build-up of dangerous atmospheres. Microbiological contamination was confined to wood chips.

  5. Dangerous (toxic) atmospheres in UK wood pellet and wood chip fuel storage

    PubMed Central

    Simpson, Andrew T.; Hemingway, Michael A.; Seymour, Cliff

    2016-01-01

    ABSTRACT There is growing use of wood pellet and wood chip boilers in the UK. Elsewhere fatalities have been reported, caused by carbon monoxide poisoning following entry into wood pellet storage areas. The aim of this work was to obtain information on how safely these two fuels are being stored in the UK. Site visits were made to six small-scale boiler systems and one large-scale pellet warehouse, to assess storage practice, risk management systems and controls, user knowledge, and potential for exposure to dangerous atmospheres. Real time measurements were made of gases in the store rooms and during laboratory tests on pellets and chips. Volatile organic compounds (VOCs) emitted and the microbiological content of the fuel was also determined. Knowledge of the hazards associated with these fuels, including confined space entry, was found to be limited at the smaller sites, but greater at the large pellet warehouse. There has been limited risk communication between companies supplying and maintaining boilers, those manufacturing and supplying fuel, and users. Risk is controlled by restricting access to the store rooms with locked entries; some store rooms have warning signs and carbon monoxide alarms. Nevertheless, some store rooms are accessed for inspection and maintenance. Laboratory tests showed that potentially dangerous atmospheres of carbon monoxide and carbon dioxide, with depleted levels of oxygen may be generated by these fuels, but this was not observed at the sites visited. Unplanned ventilation within store rooms was thought to be reducing the build-up of dangerous atmospheres. Microbiological contamination was confined to wood chips. PMID:27030057

  6. A Gyrotron-Powered Pellet Accelerator for Tokamak Fueling

    NASA Astrophysics Data System (ADS)

    Parks, P. B.; Perkins, F. W.

    2006-04-01

    A novel pellet acceleration concept [1] using microwave power from MW gyrotron sources has been developed that could pave the way for high-speed >3 km/s inner-wall pellet injection on ITER-class tokamaks. The concept is based on the principal of a gun, where a high-pressure propellant gas drives the projectile down the barrel. In the proposed concept, the high gas pressure is created by evaporative explosion of a composite ``pusher'' medium attached behind the DT fuel pellet. The pusher consists of micron-sized conducting particles, (Li, Be, C) embedded uniformly in a D2 ice slug with <5% volume concentration, thus facilitating microwave energy absorption by dissipation of eddy currents flowing within the conducting particles only. Microwave power is delivered to the pusher along a waveguide, which also serves as the pellet launch tube. A scaling law predicts that a pellet of mass M accelerated over a distance L reaches a velocity v (PL/M)^1/3, where P is the gyrotron power.pard[1] P. Parks & F. Perkins, US patent application ``Microwave-Powered Pellet Accelerator,'' No. 11/256/662, October 21, 2005.

  7. Particle transport in pellet fueled JET (Jet European Torus) plasmas

    SciTech Connect

    Baylor, L.R.

    1990-01-01

    Pellet fueling experiments have been carried out on the Joint European Torus (JET) tokamak with a multi-pellet injector. The pellets are injected at speeds approaching 1400 m/s and penetrate deep into the JET plasma. Highly peaked electron density profiles are achieved when penetration of the pellets approaches or goes beyond the magnetic axis, and these peaked profiles persist for more than two seconds in ohmic discharges and over one second in ICRF heated discharges. In this dissertation, analysis of electron particle transport in multi-pellet fueled JET limiter plasmas under a variety of heating conditions is described. The analysis is carried out with a one and one-half dimensional radial particle transport code to model the experimental density evolution with various particle transport coefficients. These analyses are carried out in plasmas with ohmic heating, ICRF heating, and neural beam heating, in limiter configurations. Peaked density profile cases are generally characterized by diffusion coefficients with a central (r/a < 0.5) diffusivity {approximately}0.1 m{sup 2}/s that increases rapidly to {approximately}0.3 m{sup 2}/s at r/a = 0.6 and then increases out to the plasma edge as (r/a){sup 2}. These discharges can be satisfactorily modeled without any anomalous convective (pinch) flux. 79 refs., 60 figs.

  8. Nuclear fuel pellet sintering boat unloading apparatus and method

    SciTech Connect

    Huggins, T.B.; Widener, W.H.; Klapper, K.K.

    1990-05-22

    This patent describes a method for unloading nuclear fuel pellets from a sintering boat having an open top. It comprises: pivoting a transfer housing loaded with the boat filled with nuclear fuel pellets about a generally horizontal axis from an upright position remote from a pellet deposit surface to an inverted position adjacent to the deposit surface to move the boat from an upright to inverted orientation with the pellets retained within the boat by a latched lid in a closed condition on the housing; unlatching the lid of the housing as the housing reaches its inverted position but engaging the unlatched lid with the deposit surface to retain it in its closed condition; and reverse pivoting the housing from its inverted position back toward its upright position to permit the unlatched lid to pivot from the closed condition to an opened condition thereby allowing pellets to slide out of the open top of the inverted boat and down the opened lid of the housing to the deposit site.

  9. Mechanical modeling of porous oxide fuel pellet A Test Problem

    SciTech Connect

    Nukala, Phani K; Barai, Pallab; Simunovic, Srdjan; Ott, Larry J

    2009-10-01

    A poro-elasto-plastic material model has been developed to capture the response of oxide fuels inside the nuclear reactors under operating conditions. Behavior of the oxide fuel and variation in void volume fraction under mechanical loading as predicted by the developed model has been reported in this article. The significant effect of void volume fraction on the overall stress distribution of the fuel pellet has also been described. An important oxide fuel issue that can have significant impact on the fuel performance is the mechanical response of oxide fuel pellet and clad system. Specifically, modeling the thermo-mechanical response of the fuel pellet in terms of its thermal expansion, mechanical deformation, swelling due to void formation and evolution, and the eventual contact of the fuel with the clad is of significant interest in understanding the fuel-clad mechanical interaction (FCMI). These phenomena are nonlinear and coupled since reduction in the fuel-clad gap affects thermal conductivity of the gap, which in turn affects temperature distribution within the fuel and the material properties of the fuel. Consequently, in order to accurately capture fuel-clad gap closure, we need to account for fuel swelling due to generation, retention, and evolution of fission gas in addition to the usual thermal expansion and mechanical deformation. Both fuel chemistry and microstructure also have a significant effect on the nucleation and growth of fission gas bubbles. Fuel-clad gap closure leading to eventual contact of the fuel with the clad introduces significant stresses in the clad, which makes thermo-mechanical response of the clad even more relevant. The overall aim of this test problem is to incorporate the above features in order to accurately capture fuel-clad mechanical interaction. Because of the complex nature of the problem, a series of test problems with increasing multi-physics coupling features, modeling accuracy, and complexity are defined with the

  10. Microwave Processing of Simulated Advanced Nuclear Fuel Pellets

    SciTech Connect

    D.E. Clark; D.C. Folz

    2010-08-29

    Throughout the three-year project funded by the Department of Energy (DOE) and lead by Virginia Tech (VT), project tasks were modified by consensus to fit the changing needs of the DOE with respect to developing new inert matrix fuel processing techniques. The focus throughout the project was on the use of microwave energy to sinter fully stabilized zirconia pellets using microwave energy and to evaluate the effectiveness of techniques that were developed. Additionally, the research team was to propose fundamental concepts as to processing radioactive fuels based on the effectiveness of the microwave process in sintering the simulated matrix material.

  11. MRT fuel element inspection at Dounreay

    SciTech Connect

    Gibson, J.

    1997-08-01

    To ensure that their production and inspection processes are performed in an acceptable manner, ie. auditable and traceable, the MTR Fuel Element Fabrication Plant at Dounreay operates to a documented quality system. This quality system, together with the fuel element manufacturing and inspection operations, has been independently certified to ISO9002-1987, EN29002-1987 and BS5750:Pt2:1987 by Lloyd`s Register Quality Assurance Limited (LRQA). This certification also provides dual accreditation to the relevant German, Dutch and Australian certification bodies. This paper briefly describes the quality system, together with the various inspection stages involved in the manufacture of MTR fuel elements at Dounreay.

  12. Compaction of AWBA fuel pellets without binders (AWBA Development Program)

    SciTech Connect

    Johnson, R.G.R.

    1982-08-01

    Highly active oxide fuel powders, composed of UO/sub 2/, UO/sub 2/-ThO/sub 2/, or ThO/sub 2/, were compacted into ultra-high density pellets without the use of binders. The objective of the study was to select the optimum die lubricant for compacting these powders into pellets in preparation for sintering to densities in excess of 97% Theoretical Density. The results showed that sintered density was a function of both the lubricant bulk density and concentration with the lowest bulk density lubricant giving the highest sintered densities with a lubricant concentration of 0.1 weight percent. Five calcium and zinc stearates were evaluated with a calcium stearate with a 15 lb/ft/sup 3/ bulk density being the best lubricant.

  13. Used Pallets as a Source of Pellet Fuel: Current Industry Status

    Treesearch

    P.B. Aruna; Jan G. Laarman; Philip A. Araman; Edward Coulter; Frederick Cubbage

    1997-01-01

    U.S. companies discard approximately 4 billion board feet per year of wood pallets and containers. Manufacturing fuel pellets from this wasted wood may be an alternative to disposal. This study traces the development of biomass energy and the wood pellet industry in the United States and considers the production aspects of making pellets from used pallets. In addition...

  14. Apparatus for unloading nuclear fuel pellets from a sintering boat

    SciTech Connect

    Bucher, G.D.; Raymond, T.E.

    1987-02-10

    An apparatus is described for unloading nuclear fuel pellets from a loaded sintering boat having an open top, comprising: (a) means for receiving the boat in an upright position with the pellets contained therein, the boat receiving means including a platform for supporting the loaded boat in the upright position, the boat supporting platform having first and second portions; (b) means for clamping the boat including a pair of plates disposed at lateral sides of the boat and being movable in a first direction relative to one another for applying clamping forces to the boat on the platform and in a second direction relative to one another for releasing the clamping forces from the boat. The pair of plates have inner surfaces facing toward one another, the first and second platform portions of the boat supporting platform being mounted to the plates on the respective facing surfaces thereof and disposed in a common plane. One of the plates and one of the platform portions mounted thereto are disposed in a stationary position and the other of the plates and the other of the platform portions mounted thereto are movable relative thereto in the first and second directions for applying and releasing clamping forces to and from the boat while the boat is supported in the upright position by the platform portions; (c) means for transferring the clamped boat from the upright position to an inverted position and then back to the upright position; and (d) means of receiving the pellets from the clamped boat as the boat is being transferred from the upright position to the inverted position.

  15. Dry Bag Isostatic Pressing for Improved Green Strength of Nuclear Fuel Pellets

    SciTech Connect

    G. W. Egeland; L. D. Zuck; W. R. Cannon; P. A. Lessing; P. G. Medvedev

    2010-11-01

    Dry bag isostatic pressing is proposed for mass production of nuclear fuel pellets. Dry bag isostatically pressed rods of a fuel surrogate (95% CeO2-5% HfO2) 200 mm long by 8 mm diameter were cut into pellets using a wire saw. Four different binder and two different CeO2 powder sources were investigated. The strength of the isostatically pressed pellets for all binder systems measured by diametral compression was about 50% higher than pellets produced by uniaxial dry pressing at the same pressure. It was proposed that the less uniform density of uniaxially pressed pellets accounted for the lower strength. The strength of pellets containing CeO2 powder with significantly higher moisture content was five times higher than pellets containing CeO2 powder with a low moisture content. Capillary pressure of the moisture was thought to supply the added binding strength.

  16. Probing RFP Density Limits and the Interaction of Pellet Fueling and NBI Heating on MST

    NASA Astrophysics Data System (ADS)

    Caspary, K. J.; Chapman, B. E.; Anderson, J. K.; Limbach, S. T.; Oliva, S. P.; Sarff, J. S.; Waksman, J.; Combs, S. K.; Foust, C. R.

    2013-10-01

    Pellet fueling on MST has previously achieved Greenwald fractions of up to 1.5 in 200 kA improved confinement discharges. Additionally, pellet fueling to densities above the Greenwald limit in 200 kA standard discharges resulted in early termination of the plasma, but pellet size was insufficient to exceed the limit for higher current discharges. To this end, the pellet injector on MST has been upgraded to increase the maximum fueling capability by increasing the size of the pellet guide tubes, which constrain the lateral motion of the pellet in flight, to accommodate pellets of up to 4.0 mm in diameter. These 4.0 mm pellets are capable of triggering density limit terminations for MST's peak current of 600 kA. An unexpected improvement in the pellet speed and mass control was also observed compared to the smaller diameter pellets. Exploring the effect of increased density on NBI particle and heat deposition shows that for MST's 1 MW tangential NBI, core deposition of 25 keV neutrals is optimized for densities of 2-3 × 1019 m-3. This is key for beta limit studies in pellet fueled discharges with improved confinement where maximum NBI heating is desired. An observed toroidal deflection of pellets injected into NBI heated discharges is consistent with asymmetric ablation due to the fast ion population. In 200 kA improved confinement plasmas with NBI heating, pellet fueling has achieved a Greenwald fraction of 2.0. Work supported by US DoE.

  17. Processing of surrogate nuclear fuel pellets for better dimensional control with dry bag isostatic pressing

    SciTech Connect

    Hoggan, Rita E.; Zuck, Larry D.; Cannon, W. Roger; Lessing, Paul A.

    2016-05-26

    A study of improved methods of processing fuel pellets was undertaken using ceria and zirconia/yttria/alumina as surrogates. Through proper granulation and vertical vibration (tapping) of the parts bag prior to dry bag isostatic pressing (DBIP), reproducibility of diameter profiles among multiple pellets of ceria was improved by almost an order of magnitude. Reproducibility of sintered pellets was sufficiently good to possibly avoid grinding. Deviation from the mean diameter along the length of multiple pellets, as well as, deviation from roundness, decreased after sintering. This is not generally observed with dry pressed pellets. Thus it is possible to machine to tolerance before sintering if grinding is necessary.

  18. Processing of surrogate nuclear fuel pellets for better dimensional control with dry bag isostatic pressing

    SciTech Connect

    Hoggan, Rita E.; Zuck, Larry D.; Cannon, W. Roger; Lessing, Paul A.

    2016-12-01

    A study of improved methods of processing fuel pellets was undertaken using ceria and zirconia/yttria/alumina as surrogates. Through proper granulation and vertical vibration (tapping) of the parts bag prior to dry bag isostatic pressing (DBIP), reproducibility of diameter profiles among multiple pellets of ceria was improved by almost an order of magnitude. Reproducibility of sintered pellets was sufficiently good to possibly avoid grinding. Deviation from the mean diameter along the length of multiple pellets, as well as, deviation from roundness, decreased after sintering. This is not generally observed with dry pressed pellets. Thus it is possible to machine to tolerance before sintering if grinding is necessary.

  19. Combustion and emissions characterization of pelletized coal fuels. Technical report, December 1, 1992--February 28, 1993

    SciTech Connect

    Rajan, S.

    1993-05-01

    The aim of this project is to demonstrate that sorbent-containing coal pellets made from low grade coal or coal wastes are viable clean burning fuels, and to compare their performance with that of standard run-of-mine coal. Fuels to be investigated are: (a) carbonated pellets containing calcium hydroxide sorbent, (b) coal fines-limestone pellets with cornstarch as binder, (c) pellets made from preparation plant recovered coal containing limestone sorbent and gasification tar as binder, and (d) a standard run-of-mine Illinois seam coal. The fuels will be tested in a laboratory scale 411 diameter circulating fluidized bed combustor. Progress this quarter has centered on the development of a hydraulic press based pellet mill capable of the high compaction pressures necessary to produce the gasification tar containing pellets outlined in (c) above. Limited quantities of the pellets have been made, and the process is being fine tuned before proceeding into the production mode. Tests show that the moisture content of the coal is an important parameter that needs to be fixed within narrow limits for a given coal and binder combination to produce acceptable pellets. Combustion tests with these pellet fuels and the standard coal are scheduled for the next quarter.

  20. Nuclear fuel pellets fabricated from gel-derived microspheres

    NASA Astrophysics Data System (ADS)

    Matthews, R. B.; Hart, P. E.

    1980-09-01

    UO2 pellets were fabricated from UO3 gel microspheres by a combined gel-sphere/pellet fabrication process. Desirable sphere properties were established; calcining cycles, pressing conditions, and sintering cycles sufficient to fabricate UO2 pellets with densities up to 96% TD were determined. The stoichoimetry, activity, density, size and deformability of the spheres had to be within specific ranges for fabrication of high density, crack-free pellets. Preliminary attempts to fabricate ThO2 and ThO2 -UO2 pellets are also described.

  1. Combustion and emissions characterization of pelletized coal fuels. [Quarterly] technical report, March 1--May 31, 1993

    SciTech Connect

    Rajan, S.

    1993-09-01

    Pelletization of coal offers a means of utilizing coal fines which otherwise would be difficult to use. Other advantages of coal pelletization include: (a) utilization of low grade fuels such as preparation plant waste, (b) impregnation of pellets with calcium carbonate or calcium hydroxide sorbent for efficient sulfur removal, and (c) utilization of coal fines of low quality in combination with different types of binders. The objective of this project is to investigate the carbon conversion efficiency and SO{sub 2} and NO{sub x} emissions from combusting pelletized coal fuels made from preparation plant waste streams using both limestone and calcium hydroxide as sorbent and cornstarch and gasification tar as binders. The combustion performance of these pelletized fuels is compared with equivalent data from a reference run-of-mine coal. Six different samples of coal pellets have been secured from ISGS researchers. Combustion and emissions characterization of these pellets in the laboratory scale 4-inch diameter circulating fluidized bed have been performed on some of the pellet samples. The pellets burn readily, and provide good bed temperature control. Preliminary results show good carbon conversion efficiencies. Oxides of nitrogen emissions are quite low and sulfur dioxide emissions are as good as or lower than those from a representative run-of-mine coal.

  2. A Comparison of Fueling with Deuterium Pellet Injection from Different Locations on the DIII-D Tokamak

    SciTech Connect

    Baylor, L.R.; Combs, S.K.; Gohil, P.; Houlberg, W.A.; Hsieh, C.; Jernigan, T.C.; Parks, P.B.

    1999-06-14

    Initial pellet injection experiments on DIII-D with high field side (HFS) injection have demonstrated that deeper pellet fuel deposition is possible even with HFS injected pellets that are significantly slower than pellets injected from the low field side (LFS) (outer midplane) location. A radial displacement of the pellet mass shortly after or during the ablation process is consistent with the observed mass deposition profiles measured shortly after injection. Vertical injection inside the magnetic axis shows some improvement in fueling efficiency over LFS injection and may provide an optimal injection location for fueling with high speed pellets.

  3. Fluidized bed combustion of pelletized biomass and waste-derived fuels

    SciTech Connect

    Chirone, R.; Scala, F.; Solimene, R.; Salatino, P.; Urciuolo, M.

    2008-10-15

    The fluidized bed combustion of three pelletized biogenic fuels (sewage sludge, wood, and straw) has been investigated with a combination of experimental techniques. The fuels have been characterized from the standpoints of patterns and rates of fuel devolatilization and char burnout, extent of attrition and fragmentation, and their relevance to the fuel particle size distribution and the amount and size distribution of primary ash particles. Results highlight differences and similarities among the three fuels tested. The fuels were all characterized by limited primary fragmentation and relatively long devolatilization times, as compared with the time scale of particle dispersion away from the fuel feeding ports in practical FBC. Both features are favorable to effective lateral distribution of volatile matter across the combustor cross section. The three fuels exhibited distinctively different char conversion patterns. The high-ash pelletized sludge burned according to the shrinking core conversion pattern with negligible occurrence of secondary fragmentation. The low-ash pelletized wood burned according to the shrinking particle conversion pattern with extensive occurrence of secondary fragmentation. The medium-ash pelletized straw yielded char particles with a hollow structure, resembling big cenospheres, characterized by a coherent inorganic outer layer strong enough to prevent particle fragmentation. Inert bed particles were permanently attached to the hollow pellets as they were incorporated into ash melts. Carbon elutriation rates were very small for all the fuels tested. For pelletized sludge and straw, this was mostly due to the shielding effect of the coherent ash skeleton. For the wood pellet, carbon attrition was extensive, but was largely counterbalanced by effective afterburning due to the large intrinsic reactivity of attrited char fines. The impact of carbon attrition on combustion efficiency was negligible for all the fuels tested. The size

  4. Shock and vibration tests of uranium mononitride fuel pellets for a space power nuclear reactor

    NASA Technical Reports Server (NTRS)

    Adams, D. W.

    1972-01-01

    Shock and vibration tests were conducted on cylindrically shaped, depleted, uranium mononitride (UN) fuel pellets. The structural capabilities of the pellets were determined under exposure to shock and vibration loading which a nuclear reactor may encounter during launching into space. Various combinations of diametral and axial clearances between the pellets and their enclosing structures were tested. The results of these tests indicate that for present fabrication of UN pellets, a diametral clearance of 0.254 millimeter and an axial clearance of 0.025 millimeter are tolerable when subjected to launch-induced loads.

  5. Development of an integrated, unattended assay system for LWR-MOX fuel pellet trays

    SciTech Connect

    Stewart, J.E.; Hatcher, C.R.; Pollat, L.L.

    1994-08-01

    Four identical unattended plutonium assay systems have been developed for use at the new light-water-reactor mixed oxide (LWR-MOX) fuel fabrication facility at Hanau, Germany. The systems provide quantitative plutonium verification for all MOX pellet trays entering or leaving a large, intermediate store. Pellet-tray transport and storage systems are highly automated. Data from the ``I-Point`` (information point) assay systems will be shared by the Euratom and International Atomic Energy Agency (IAEA) Inspectorates. The I-Point system integrates, for the first time, passive neutron coincidence counting (NCC) with electro-mechanical sensing (EMS) in unattended mode. Also, provisions have been made for adding high-resolution gamma spectroscopy. The system accumulates data for every tray entering or leaving the store between inspector visits. During an inspection, data are analyzed and compared with operator declarations for the previous inspection period, nominally one month. Specification of the I-point system resulted from a collaboration between the IAEA, Euratom, Siemens, and Los Alamos. Hardware was developed by Siemens and Los Alamos through a bilateral agreement between the German Federal Ministry of Research and Technology (BMFT) and the US DOE. Siemens also provided the EMS subsystem, including software. Through the USSupport Program to the IAEA, Los Alamos developed the NCC software (NCC COLLECT) and also the software for merging and reviewing the EMS and NCC data (MERGE/REVIEW). This paper describes the overall I-Point system, but emphasizes the NCC subsystem, along with the NCC COLLECT and MERGE/REVIEW codes. We also summarize comprehensive testing results that define the quality of assay performance.

  6. Fabrication of very high density fuel pellets of thorium dioxide

    NASA Astrophysics Data System (ADS)

    Shiratori, Tetsuo; Fukuda, Kosaku

    1993-06-01

    Very high density ThO 2 pellets were prepared without binders and lubricants from the ThO 2 powder originated by the thorium oxalate, which was aimed to simplify the fabrication process by skipping a preheat treatment. The as-received ThO 2 powder with a surface area of 4.56 m 2/g was ball-milled up to about 9 m 2/g in order to increase the green pellet density as high as possible. Both of the single-sided and the double-sided pressing were tested in the range from 2 to 5 t/cm 2 in the green pellet formation. Sintering temperature was such low as 1550°C. The pellet prepared in this experiment had a very high density in the range from about 96 to 98% TD without any cracks, in which a difference of the pellet density was not recognized in the single-sided pressing methods.

  7. Inspection procedures for experimental fuel production

    NASA Astrophysics Data System (ADS)

    Campsie, I. C.; Rattray, H. D.

    1988-04-01

    This paper describes the inspection procedures used in the development and manufacture of experimental fuel elements and their components. The examples quoted mainly apply to the PFR experimental fuel programme, although for well over a quarter of a century the procedures and techniques have been progressively developed and applied to the Magnox, SGHW, AGR, HTR, PFR and PWR fuel development programmes undertaken at the UKAEA's Springfields and Windscale Nuclear Power Development Laboratories. In contrast to production runs involving large numbers of standard components, experimental fuel is often assembled from components which, while they may look alike, may have design and material variations. Thus in addition to normal batching and bonding operations, great emphasis has to be placed on dimensional inspection, material testing and the individual identification of all items, thus maintaining traceability throughout all operations. The quality and performance of experimental items are often evaluated comparing pre- and post-test dimensional or NDT measurements. In the case of irradiation tests, several years can elapse between the measurements, therefore it is essential to ensure the reproducibility and compatibility of pre- and post-test measuring techniques and the traceability of all measured data and standards.

  8. Inspection of irradiated P-7 fuel tubes

    SciTech Connect

    Peacock, H.B.; Sturcken, E.F.

    1980-08-20

    Mark 16 U-A1 alloy production fuel tubes and six special U{sub 3}O{sub 8}-A1 powder metallurgy (PM) test assemblies were successfully irradiated in P-7 reactor charge beginning December 1976. A year after irradiation, the outer surfaces were inspected under water in P-Area basin. Inspection showed that a black'' oxide had formed on the bottom {sup {approximately}}2/3 and flaked off in some areas for both the production and PM tubes. A small cladding defect was also observed on one PM outer tube near the bottom. Sections were cut from the tubes and metallographically examined in the SRL High Level Caves (HLC). This report gives results of the examinations. 8 refs., 9 figs., 1 tab.

  9. Inspection of Used Fuel Dry Storage Casks

    SciTech Connect

    Dennis C. Kunerth; Tim McJunkin; Mark McKay; Sasan Bakhtiari

    2012-09-01

    ABSTRACT The U.S. Nuclear Regulatory Commission (NRC) regulates the storage of used nuclear fuel, which is now and will be increasingly placed in dry storage systems. Since a final disposition pathway is not defined, the fuel is expected to be maintained in dry storage well beyond the time frame originally intended. Due to knowledge gaps regarding the viability of current dry storage systems for long term use, efforts are underway to acquire the technical knowledge and tools required to understand the issues and verify the integrity of the dry storage system components. This report summarizes the initial efforts performed by researchers at Idaho National Laboratory and Argonne National Laboratory to identify and evaluate approaches to in-situ inspection dry storage casks. This task is complicated by the design of the current storage systems that severely restrict access to the casks.

  10. Processing of surrogate nuclear fuel pellets for better dimensional control with dry bag isostatic pressing

    DOE PAGES

    Hoggan, Rita E.; Zuck, Larry D.; Cannon, W. Roger; ...

    2016-05-26

    A study of improved methods of processing fuel pellets was undertaken using ceria and zirconia/yttria/alumina as surrogates. Through proper granulation and vertical vibration (tapping) of the parts bag prior to dry bag isostatic pressing (DBIP), reproducibility of diameter profiles among multiple pellets of ceria was improved by almost an order of magnitude. Reproducibility of sintered pellets was sufficiently good to possibly avoid grinding. Deviation from the mean diameter along the length of multiple pellets, as well as, deviation from roundness, decreased after sintering. This is not generally observed with dry pressed pellets. Thus it is possible to machine to tolerancemore » before sintering if grinding is necessary.« less

  11. Advanced Ultrasonic Inspection Techniques for General Purpose Heat Source Fueled Clad Closure Welds

    SciTech Connect

    Moyer, M.W.

    2001-01-11

    A radioisotope thermoelectric generator is used to provide a power source for long-term deep space missions. This General Purpose Heat Source (GPHS) is fabricated using iridium clad vent sets to contain the plutonium oxide fuel pellets. Integrity of the closure weld is essential to ensure containment of the plutonium. The Oak Ridge Y-12 Plant took the lead role in developing the ultrasonic inspection for the closure weld and transferring the inspection to Los Alamos National Laboratory for use in fueled clad inspection for the Cassini mission. Initially only amplitude and time-of-flight data were recorded. However, a number of benign geometric conditions produced signals that were larger than the acceptance threshold. To identify these conditions, a B-scan inspection was developed that acquired full ultrasonic waveforms. Using a test protocol the B-scan inspection was able to identify benign conditions such as weld shield fusion and internal mismatch. Tangential radiography was used to confirm the ultrasonic results. All but two of 29 fueled clads for which ultrasonic B-scan data was evaluated appeared to have signals that could be attributed to benign geometric conditions. This report describes the ultrasonic inspection developed at Y-12 for the Cassini mission.

  12. Alternative methods for Inspection for Fuel Cleanliness Test Plan

    SciTech Connect

    STEGEN, G.E.

    2002-10-31

    The current fuel cleanliness inspection process and has been a bottleneck that has frequently resulted in process delays and loss of production capacity. The current inspection process is based on a rolling lot inspection process wherein individual fuel assemblies are inspected by using the manipulators to handle the assembly during the process and then loading the assembly into a fuel basket. This process is slow, depends on the operability of one of the least reliable systems of the process, and has resulted in several delays in the fuel production process. Preliminary discussions and analysis have identified alternative methods of inspection that would move the inspections away from the manipulators, resulting in improved reliability of the process. This test plan defines investigations and testing of the identified alternative inspection methods.

  13. Characterization of (Th,U)O 2 fuel pellets made by impregnation technique

    NASA Astrophysics Data System (ADS)

    Kutty, T. R. G.; Nair, M. R.; Sengupta, P.; Basak, U.; Kumar, Arun; Kamath, H. S.

    2008-02-01

    Impregnation technique is an attractive alternative for manufacturing highly radiotoxic 233U bearing thoria based mixed oxide fuel pellets, which are remotely treated in hot cell or shielded glove-box facilities. This technique is being investigated to fabricate the fuel for the forthcoming Indian Advanced Heavy Water Reactor (AHWR). In the impregnation process, porous ThO 2 pellets are prepared in an unshielded facility which are then impregnated with 1.5 molar uranyl nitrate solution in a shielded facility. The resulting composites are dried and denitrated at 500 °C and then sintered in reducing/oxidizing atmosphere to obtain high density (Th,U)O 2 pellets. In this work, the densification behaviour of ThO 2-2% UO 2 and ThO 2-4% UO 2 pellets was studied in reducing and oxidizing atmospheres using a high temperature dilatometer. Densification was found to be larger in air than in Ar-8% H 2. The characterization of the sintered pellets was made by optical microscopy, scanning electron microscopy (SEM) and electron probe microanalysis (EPMA). The grain structure of ThO 2-2% UO 2 and ThO 2-4% UO 2 pellets was uniform. The EPMA data confirmed that the uranium concentration was slightly higher at the periphery of the pellet than that at the centre.

  14. SGMP — an advanced method for fabrication of UO 2 and mox fuel pellets

    NASA Astrophysics Data System (ADS)

    Zimmer, E.; Ganguly, C.; Borchardt, J.; Langen, H.

    1988-05-01

    The External Gelation of Uranium (EGU) process, though originally developed for preparation of fuel particles for High-Temperature Reactors (HTR), was also found to be attractive for Sol-Gel Microsphere Pelletization (SGMP) of UO 2 and mixed oxide (MOX) fuel. No major changes of the process were necessary. However, for producing "porous microsphere" carbon black was added to the broth and later burnt out from the gel micropheres. Both "porous" and "non-porous" microspheres have been easily pelletized and sintered to high densities (≥ 95% TD) at relatively low temperatures (≤ 1500 ° C) in CO 2 atmosphere. The "porous" microspheres led to sintered pellets having closed pores in the diameter range of 2-5 μm. Such pellets are good for retention of fission gases and are hence recommended for water-cooled reactor fuel pins. The pellets prepared from "non-porous" microspheres had "open pores" and are suitable for LMFBR fuel pins. UO 2—5% CeO 2 and UO 2-30% CeO 2 were chosen to simulate MOX fuels for thermal and fast reactors, respectively.

  15. Processing of surrogate nuclear fuel pellets for better dimensional control with dry bag isostatic pressing

    NASA Astrophysics Data System (ADS)

    Hoggan, Rita E.; Zuck, Larry D.; Cannon, W. Roger; Lessing, Paul A.

    2016-12-01

    A study of improved methods of processing fuel pellets was undertaken using ceria and zirconia/yttria/alumina as surrogates. Through proper granulation, elimination of fines and vertical vibration (tapping) of the parts bag prior to dry bag isostatic pressing (DBIP), reproducibility of diameter profiles among multiple pellets of ceria was improved by almost an order of magnitude. Reproducibility of sintered pellets in these studies was sufficient to allow pellets to be introduced into the cladding with a gap between the pellet and cladding on the order of 50 μm to 100 μm but not a uniform gap with tolerance of ±12 μm as is currently required. Deviation from the mean diameter along the length of multiple pellets, and deviation from roundness, decreased after sintering. This is not generally observed with dry pressed pellets. Sintered shrinkage was uniform to ±0.05% and thus, as an alternative, pellets may be machined to tolerance before sintering, thus avoiding the waste associated with post-sinter grinding.

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

    NASA Astrophysics Data System (ADS)

    Drera, Saleem S.; Björk, Klara Insulander; Sobieska, Matylda

    2016-10-01

    Thorium dioxide (thoria) has potential to assist in niche roles as fuel for light water reactors (LWRs). One such application for thoria is its use as the fertile component to burn plutonium in a mixed oxide fuel (MOX). Thor Energy and an international consortium are currently irradiating plutonia-thoria (Th-MOX) fuel in an effort to produce data for its licensing basis. During fuel-manufacturing research and development (R&D), surrogate materials were utilized to highlight procedures and build experience. Cerium dioxide (ceria) provides a good surrogate platform to replicate the chemical nature of plutonium dioxide. The project's fuel manufacturing R&D focused on powder metallurgical techniques to ensure manufacturability with the current commercial MOX fuel production infrastructure. The following paper highlights basics of the ceria-thoria fuel production including powder milling, pellet pressing and pellet sintering. Green pellets and sintered pellets were manufactured with average densities of 67.0% and 95.5% that of theoretical density respectively.

  17. Uranium silicide pellet fabrication by powder metallurgy for accident tolerant fuel evaluation and irradiation

    SciTech Connect

    Harp, Jason Michael; Lessing, Paul Alan; Hoggan, Rita Elaine

    2015-06-21

    In collaboration with industry, Idaho National Laboratory is investigating uranium silicide for use in future light water reactor fuels as a more accident resistant alternative to uranium oxide base fuels. Specifically this project was focused on producing uranium silicide (U3Si2) pellets by conventional powder metallurgy with a density greater than 94% of the theoretical density. This work has produced a process to consistently produce pellets with the desired density through careful optimization of the process. Milling of the U3Si2 has been optimized and high phase purity U3Si2 has been successfully produced. Results are presented from sintering studies and microstructural examinations that illustrate the need for a finely ground reproducible particle size distribution in the source powder. The optimized process was used to produce pellets for the Accident Tolerant Fuel-1 irradiation experiment. The average density of these pellets was 11.54 ±0.06 g/cm3. Additional characterization of the pellets by scaning electron microscopy and X-ray diffraction has also been performed. As a result, pellets produced in this work have been encapsulated for irradiation, and irradiation in the Advanced Test Reactor is expected soon.

  18. Uranium silicide pellet fabrication by powder metallurgy for accident tolerant fuel evaluation and irradiation

    DOE PAGES

    Harp, Jason Michael; Lessing, Paul Alan; Hoggan, Rita Elaine

    2015-06-21

    In collaboration with industry, Idaho National Laboratory is investigating uranium silicide for use in future light water reactor fuels as a more accident resistant alternative to uranium oxide base fuels. Specifically this project was focused on producing uranium silicide (U3Si2) pellets by conventional powder metallurgy with a density greater than 94% of the theoretical density. This work has produced a process to consistently produce pellets with the desired density through careful optimization of the process. Milling of the U3Si2 has been optimized and high phase purity U3Si2 has been successfully produced. Results are presented from sintering studies and microstructural examinationsmore » that illustrate the need for a finely ground reproducible particle size distribution in the source powder. The optimized process was used to produce pellets for the Accident Tolerant Fuel-1 irradiation experiment. The average density of these pellets was 11.54 ±0.06 g/cm3. Additional characterization of the pellets by scaning electron microscopy and X-ray diffraction has also been performed. As a result, pellets produced in this work have been encapsulated for irradiation, and irradiation in the Advanced Test Reactor is expected soon.« less

  19. Uranium silicide pellet fabrication by powder metallurgy for accident tolerant fuel evaluation and irradiation

    NASA Astrophysics Data System (ADS)

    Harp, Jason M.; Lessing, Paul A.; Hoggan, Rita E.

    2015-11-01

    In collaboration with industry, Idaho National Laboratory is investigating uranium silicide for use in future light water reactor fuels as a more accident resistant alternative to uranium oxide base fuels. Specifically this project was focused on producing uranium silicide (U3Si2) pellets by conventional powder metallurgy with a density greater than 94% of the theoretical density. This work has produced a process to consistently produce pellets with the desired density through careful optimization of the process. Milling of the U3Si2 has been optimized and high phase purity U3Si2 has been successfully produced. Results are presented from sintering studies and microstructural examinations that illustrate the need for a finely ground reproducible particle size distribution in the source powder. The optimized process was used to produce pellets for the Accident Tolerant Fuel-1 irradiation experiment. The average density of these pellets was 11.54 ± 0.06 g/cm3. Additional characterization of the pellets by scanning electron microscopy and X-ray diffraction has also been performed. Pellets produced in this work have been encapsulated for irradiation, and irradiation in the Advanced Test Reactor is expected soon.

  20. Zooplankton fecal pellets link fossil fuel and phosphate deposits

    SciTech Connect

    Porter, K.G.; Robbins, E.I.

    1981-05-22

    Fossil zooplankton fecal pellets found in thinly bedded marine and lacustrine black shales associated with phosphate, oil, and coal deposits, link the deposition of organic matter and biologically associated minerals with planktonic ecosystems. The black shales were probably formed in the anoxic basins of coastal marine waters, inland seas, and rift valley lakes where high productivity was supported by runoff, upwelling, and outwelling.

  1. Zooplankton fecal pellets link fossil fuel and phosphate deposits.

    PubMed

    Porter, K G; Robbins, E I

    1981-05-22

    Fossil zooplankton fecal pellets found in thinly bedded marine and lacustrine black shales associated with phosphate, oil, and coal deposits, link the deposition of organic matter and biologically associated minerals with planktonic ecosystems. The black shales were probably formed in the anoxic basins of coastal marine waters, inland seas, and rift valley lakes where high productivity was supported by runoff, upwelling, and outwelling.

  2. 3D Simulation of Missing Pellet Surface Defects in Light Water Reactor Fuel Rods

    SciTech Connect

    B.W. Spencer; J.D. Hales; S.R. Novascone; R.L. Williamson

    2012-09-01

    The cladding on light water reactor (LWR) fuel rods provides a stable enclosure for fuel pellets and serves as a first barrier against fission product release. Consequently, it is important to design fuel to prevent cladding failure due to mechanical interactions with fuel pellets. Cladding stresses can be effectively limited by controlling power increase rates. However, it has been shown that local geometric irregularities caused by manufacturing defects known as missing pellet surfaces (MPS) in fuel pellets can lead to elevated cladding stresses that are sufficiently high to cause cladding failure. Accurate modeling of these defects can help prevent these types of failures. Nuclear fuel performance codes commonly use a 1.5D (axisymmetric, axially-stacked, one-dimensional radial) or 2D axisymmetric representation of the fuel rod. To study the effects of MPS defects, results from 1.5D or 2D fuel performance analyses are typically mapped to thermo-mechanical models that consist of a 2D plane-strain slice or a full 3D representation of the geometry of the pellet and clad in the region of the defect. The BISON fuel performance code developed at Idaho National Laboratory employs either a 2D axisymmetric or 3D representation of the full fuel rod. This allows for a computational model of the full fuel rod to include local defects. A 3D thermo-mechanical model is used to simulate the global fuel rod behavior, and includes effects on the thermal and mechanical behavior of the fuel due to accumulation of fission products, fission gas production and release, and the effects of fission gas accumulation on thermal conductivity across the fuel-clad gap. Local defects can be modeled simply by including them in the 3D fuel rod model, without the need for mapping between two separate models. This allows for the complete set of physics used in a fuel performance analysis to be included naturally in the computational representation of the local defect, and for the effects of the

  3. Effects of Beryllium and Compaction Pressure on the Thermal Diffusivity of Uranium Dioxide Fuel Pellets

    NASA Astrophysics Data System (ADS)

    Camarano, D. M.; Mansur, F. A.; Santos, A. M. M.; Ferraz, W. B.; Ferreira, R. A. N.

    2017-09-01

    In nuclear reactors, the performance of uranium dioxide (UO2) fuel is strongly dependent on the thermal conductivity, which directly affects the fuel pellet temperature, the fission gas release and the fuel rod mechanical behavior during reactor operation. The use of additives to improve UO2 fuel performance has been investigated, and beryllium oxide (BeO) appears as a suitable additive because of its high thermal conductivity and excellent chemical compatibility with UO2. In this paper, UO2-BeO pellets were manufactured by mechanical mixing, pressing and sintering processes varying the BeO contents and compaction pressures. Pellets with BeO contents of 2 wt%, 3 wt%, 5 wt% and 7 wt% BeO were pressed at 400 MPa, 500 MPa and 600 MPa. The laser flash method was applied to determine the thermal diffusivity, and the results showed that the thermal diffusivity tends to increase with BeO content. Comparing thermal diffusivity results of UO2 with UO2-BeO pellets, it was observed that there was an increase in thermal diffusivity of at least 18 % for the UO2-2 wt% BeO pellet pressed at 400 MPa. The maximum relative expanded uncertainty (coverage factor k = 2) of the thermal diffusivity measurements was estimated to be 9 %.

  4. Preparation, characterisation and out-of-pile property evaluation of (U,Pu)N fuel pellets

    NASA Astrophysics Data System (ADS)

    Ganguly, C.; Hegde, P. V.; Sengupta, A. K.

    1991-02-01

    (U 0.45Pu 0.55)N and (U 0.8Pu 0.2)N are being considered in India as advanced alternative fuels for the operating fast breeder test reactor (FBTR) and the forthcoming prototype fast breeder reactor (PFBR). Mixed nitride fuel pellets containing <0.1 wt% each of oxygen and carbon impurities were fabricated by the conventional "powder-pellet" (POP) and the advanced "sol-gel microsphere pelletisation" (SGMP) processes, involving two major steps. First, carbothermic reduction of an oxide-graphite powder mixture (in the form of tablets) or gel-microspheres at 1773-1823 K in N 2 followed by N2 + H2 and Ar+ H2 atmospheres. The nitride microspheres could be directly pelletised and sintered to pellets of relatively low density (≤ 85% TD) with an "open" pore structure desirable for LMFBR application. Thermal conductivity and hot hardness of nitride pellets were evaluated up to 1800 and 1500 K respectively. The out-of-pile chemical compatibility experiments of mixed nitride fuel pellets for FBTR with SS 316 cladding at 973 K for 1000 h did not reveal any significant fuel-cladding chemical interaction.

  5. Transport and micro-instability analysis of JET H-mode plasma during pellet fueling

    NASA Astrophysics Data System (ADS)

    Klaywittaphat, P.; Onjun, T.

    2017-02-01

    Transport and micro-instability analysis in a JET H-mode plasma discharge 53212 during the pellet fueling operation is carried out using the BALDUR integrated predictive modeling code with a combination of the NCLASS neoclassical transport model and an anomalous core transport model (either Mixed B/gB or MMM95 model). In this work, the evolution of plasma current, plasma density and temperature profiles is carried out and, consequently, the plasma’s behaviors during the pellet operation can be observed. The NGS pellet model with the Grad-B drift effect included is used to describe pellet ablation and its behaviors when a pellet is launched into hot plasma. The simulation shows that after each pellet enters the plasma, there is a strong perturbation on the plasma causing a sudden change of both thermal and particle profiles, as well as the thermal and particle transports. For the simulation using MMM95 transport model, the change of both thermal and particle transports during pellet injection are found to be dominated by the transport due to the resistive ballooning modes due to the increase of collisionality and resistivity near the plasma edge. For the simulation based on mixed B/gB transport model, it is found that the change of transport during the pellet injection is dominated by the Bohm term. Micro-instability analysis of the plasma during the time of pellet operation is also carried out for the simulations based on MMM95 transport model. It is found that the ion temperature gradient mode is destabilized due to an increase of temperature gradient in the pellet effective region, while the trapped electron mode is stabilized due to an increase of collisionality in that region.

  6. 14 CFR 91.1507 - Fuel tank system inspection program.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 2 2014-01-01 2014-01-01 false Fuel tank system inspection program. 91.1507 Section 91.1507 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... Airworthiness and Safety Improvements § 91.1507 Fuel tank system inspection program. (a) Except as provided...

  7. 14 CFR 91.1507 - Fuel tank system inspection program.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 2 2013-01-01 2013-01-01 false Fuel tank system inspection program. 91.1507 Section 91.1507 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... Airworthiness and Safety Improvements § 91.1507 Fuel tank system inspection program. (a) Except as provided...

  8. 14 CFR 125.507 - Fuel tank system inspection program.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Fuel tank system inspection program. 125.507 Section 125.507 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... Airworthiness and Safety Improvements § 125.507 Fuel tank system inspection program. (a) Except as provided...

  9. Zooplankton fecal pellets link fossil fuel and phosphate deposits

    USGS Publications Warehouse

    Porter, K.G.; Robbins, E.I.

    1981-01-01

    Fossil zooplankton fecal pellets found in thinly bedded marine and lacustrine black shales associated with phosphate, oil, and coal deposits, link the deposition of organic matter and biologically associated minerals with planktonic ecosystems. The black shales were probably formed in the anoxic basins of coastal marine waters, inland seas, and rift valley lakes where high productivity was supported by runoff, upwelling, and outwelling. Copyright ?? 1981 AAAS.

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

    NASA Astrophysics Data System (ADS)

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

    2014-07-01

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

  11. High-speed repetitive pellet injector for plasma fueling of magnetic confinement fusion devices

    SciTech Connect

    Combs, S.K.; Baylor, L.R.; Foust, C.R.

    1993-11-01

    The projected fueling requirements of future magnetic confinement devices for controlled thermonuclear research [e.g., the International Thermonuclear Experimental Reactor (ITER)] indicate that a flexible plasma fueling capability is required. This includes a mix of traditional gas puffing and low- and high-velocity deuterium-tritium pellets. Conventional pellet injectors (based on light gas guns or centrifugal accelerators) can reliably provide frozen hydrogen pellets (1- to 6-mm-diam sizes tested) up to {approximately}1.3-km/s velocity at the appropriate pellet fueling rates (1 to 10 Hz or greater). For long-pulse operation in a higher velocity regime (>2 km/s), an experiment in collaboration between Oak Ridge National Laboratory (ORNL) and ENEA Frascati is under way. This activity will be carried out in the framework of a collaborative agreement between the US Department of Energy and European Atomic Energy Community -- ENEA Association. In this experiment, an existing ORNL hydrogen extruder (equipped with a pellet chambering mechanism/gun barrel assembly) and a Frascati two-stage light gas gun driver have been combined on a test facility at ORNL. Initial testing has been carried out with single deuterium pellets accelerated up to 2.05 km/s with the two-stage driver; in addition, some preliminary repetitive testing (to commission the diagnostics) was performed at reduced speeds, including sequences at 0.5 to 1 Hz and 10 to 30 pellets. The primary objective of this study is to demonstrate repetitive operation (up to {approximately}1 Hz) with speeds in the 2- to 3-km/s range. In addition, the strength of extruded hydrogen ice as opposed to that produced in situ by direct condensation in pipe guns can be investigated. The equipment and initial experimental results are described.

  12. 3D modeling of missing pellet surface defects in BWR fuel

    SciTech Connect

    Spencer, B. W.; Williamson, R. L.; Stafford, D. S.; Novascone, S. R.; Hales, J. D.; Pastore, G.

    2016-10-01

    Maintaining integrity of the cladding in light water reactor fuel rods is essential for ensuring that it fulfills its role of preventing fission product release. Local geometric irregularities in fuel pellets caused by manufacturing defects known as missing pellet surfaces (MPS) can in some circumstances lead to elevated cladding stresses that are sufficiently high to cause cladding failure. Accurate modeling of these defects can help prevent these types of failures. The BISON fuel performance code developed at Idaho National Laboratory is capable of modeling fuel in either 2D or 3D, and can be used to simulate the global thermo-mechanical fuel rod behavior, including evolution of the thermal and mechanical properties of the fuel as it undergoes fission, fission gas production and release, and the effect of the released gas on the thermal conductivity across the fuel-clad gap. Local defects can be modeled by directly including them in the 3D fuel rod model. This allows for the complete set of physics used in a fuel performance analysis to be included naturally in the computational representation of the local defect, and for the effects of the local defect to be coupled with the global fuel rod model. This approach for modeling fuel with MPS defects is demonstrated and the benefits of this approach are highlighted. The effects of varying parameters of the MPS defect are studied using this technique and presented here.

  13. Zirconium carbonitride pellets by internal sol gel and spark plasma sintering as inert matrix fuel material

    NASA Astrophysics Data System (ADS)

    Hedberg, Marcus; Cologna, Marco; Cambriani, Andrea; Somers, Joseph; Ekberg, Christian

    2016-10-01

    Inert matrix fuel is a fuel type where the fissile material is blended with a solid diluent material. In this work zirconium carbonitride microspheres have been produced by internal sol gel technique, followed by carbothermal reduction. Material nitride purities in the produced materials ranged from Zr(N0.45C0.55) to Zr(N0.74C0.26) as determined by X-ray diffraction and application of Vegard's law. The zirconium carbonitride microspheres have been pelletized by spark plasma sintering (SPS) and by conventional cold pressing and sintering. In all SPS experiments cohesive pellets were formed. Maximum final density reached by SPS at 1700 °C was 87% theoretical density (TD) compared to 53% TD in conventional sintering at 1700 °C. Pore sizes in all the produced pellets were in the μm scale and no density gradients could be observed by computer tomography.

  14. Validation of the BISON 3D Fuel Performance Code: Temperature Comparisons for Concentrically and Eccentrically Located Fuel Pellets

    SciTech Connect

    J. D. Hales; D. M. Perez; R. L. Williamson; S. R. Novascone; B. W. Spencer

    2013-03-01

    BISON is a modern finite-element based nuclear fuel performance code that has been under development at the Idaho National Laboratory (USA) since 2009. The code is applicable to both steady and transient fuel behaviour and is used to analyse either 2D axisymmetric or 3D geometries. BISON has been applied to a variety of fuel forms including LWR fuel rods, TRISO-coated fuel particles, and metallic fuel in both rod and plate geometries. Code validation is currently in progress, principally by comparison to instrumented LWR fuel rods. Halden IFA experiments constitute a large percentage of the current BISON validation base. The validation emphasis here is centreline temperatures at the beginning of fuel life, with comparisons made to seven rods from the IFA-431 and 432 assemblies. The principal focus is IFA-431 Rod 4, which included concentric and eccentrically located fuel pellets. This experiment provides an opportunity to explore 3D thermomechanical behaviour and assess the 3D simulation capabilities of BISON. Analysis results agree with experimental results showing lower fuel centreline temperatures for eccentric fuel with the peak temperature shifted from the centreline. The comparison confirms with modern 3D analysis tools that the measured temperature difference between concentric and eccentric pellets is not an artefact and provides a quantitative explanation for the difference.

  15. Sensitivity analysis of a dry-processed Candu fuel pellet's design parameters

    SciTech Connect

    Choi, Hangbok; Ryu, Ho Jin

    2007-07-01

    Sensitivity analysis was carried out in order to investigate the effect of a fuel pellet's design parameters on the performance of a dry-processed Canada deuterium uranium (CANDU) fuel and to suggest the optimum design modifications. Under a normal operating condition, a dry-processed fuel has a higher internal pressure and plastic strain due to a higher fuel centerline temperature when compared with a standard natural uranium CANDU fuel. Under a condition that the fuel bundle dimensions do not change, sensitivity calculations were performed on a fuel's design parameters such as the axial gap, dish depth, gap clearance and plenum volume. The results showed that the internal pressure and plastic strain of the cladding were most effectively reduced if a fuel's element plenum volume was increased. More specifically, the internal pressure and plastic strain of the dry-processed fuel satisfied the design limits of a standard CANDU fuel when the plenum volume was increased by one half a pellet, 0.5 mm{sup 3}/K. (authors)

  16. Pellet-cladding interaction of LMFBR fuel elements at unsteady state. [ISUNE-5 code

    SciTech Connect

    Ma, B.M.

    1981-10-01

    The fuel pellet-cladding interaction (PCI) of liquid-metal fast breeder reactor (LMFBR) fuel elements or fuel rods at unsteady state is analyzed based on experimental results. The heat generation, fuel restructuring, temperature distribution, gap conductance, irradiation swelling, irradiation creep, fuel burnup, fission gas release, fuel pellet cracking, crack healing, cladding cracking, yield failure and fracture failure of the fuel elements are taken into consideration. To improve the sintered (U,Pu)O/sub 2/ fuel performance and reactor core safety at high temperature and fuel burnup, it is desirable to (a) increase and maintain the ductility of cladding material, (b) provide sufficient gap thickness and plenum space for accommodating fission gas release, (c) keep ramps-power increase rate slow and gentle, and (d) reduce the intensity and frequency of transient PCI in order to avoid intense stress fatigue cracking (SFC) and stress corrosion cracking (SCC) due to fission product compounds CsI, CdI/sub 2/, Cs/sub 2/Te, etc. at the inner cladding surface of the fuel elements during PCI. 10 refs.

  17. 3D modeling of missing pellet surface defects in BWR fuel

    SciTech Connect

    Spencer, B. W.; Williamson, R. L.; Stafford, D. S.; Novascone, S. R.; Hales, J. D.; Pastore, G.

    2016-07-26

    One of the important roles of cladding in light water reactor fuel rods is to prevent the release of fission products. To that end, it is essential that the cladding maintain its integrity under a variety of thermal and mechanical loading conditions. Local geometric irregularities in fuel pellets caused by manufacturing defects known as missing pellet surfaces (MPS) can in some circumstances lead to elevated cladding stresses that are sufficiently high to cause cladding failure. Accurate modeling of these defects can help prevent these types of failures. The BISON nuclear fuel performance code developed at Idaho National Laboratory can be used to simulate the global thermo-mechanical fuel rod behavior, as well as the local response of regions of interest, in either 2D or 3D. In either case, a full set of models to represent the thermal and mechanical properties of the fuel, cladding and plenum gas is employed. A procedure for coupling 2D full-length fuel rod models to detailed 3D models of the region of the rod containing a MPS defect is detailed in this paper. The global and local model each contain appropriate physics and behavior models for nuclear fuel. This procedure is demonstrated on a simulation of a boiling water reactor (BWR) fuel rod containing a pellet with an MPS defect, subjected to a variety of transient events, including a control blade withdrawal and a ramp to high power. The importance of modeling the local defect using a 3D model is highlighted by comparing 3D and 2D representations of the defective pellet region. Finally, parametric studies demonstrate the effects of the choice of gaseous swelling model and of the depth and geometry of the MPS defect on the response of the cladding adjacent to the defect.

  18. 3D modeling of missing pellet surface defects in BWR fuel

    DOE PAGES

    Spencer, B. W.; Williamson, R. L.; Stafford, D. S.; ...

    2016-07-26

    One of the important roles of cladding in light water reactor fuel rods is to prevent the release of fission products. To that end, it is essential that the cladding maintain its integrity under a variety of thermal and mechanical loading conditions. Local geometric irregularities in fuel pellets caused by manufacturing defects known as missing pellet surfaces (MPS) can in some circumstances lead to elevated cladding stresses that are sufficiently high to cause cladding failure. Accurate modeling of these defects can help prevent these types of failures. The BISON nuclear fuel performance code developed at Idaho National Laboratory can bemore » used to simulate the global thermo-mechanical fuel rod behavior, as well as the local response of regions of interest, in either 2D or 3D. In either case, a full set of models to represent the thermal and mechanical properties of the fuel, cladding and plenum gas is employed. A procedure for coupling 2D full-length fuel rod models to detailed 3D models of the region of the rod containing a MPS defect is detailed in this paper. The global and local model each contain appropriate physics and behavior models for nuclear fuel. This procedure is demonstrated on a simulation of a boiling water reactor (BWR) fuel rod containing a pellet with an MPS defect, subjected to a variety of transient events, including a control blade withdrawal and a ramp to high power. The importance of modeling the local defect using a 3D model is highlighted by comparing 3D and 2D representations of the defective pellet region. Finally, parametric studies demonstrate the effects of the choice of gaseous swelling model and of the depth and geometry of the MPS defect on the response of the cladding adjacent to the defect.« less

  19. Nuclear fuel element with axially aligned fuel pellets and fuel microspheres therein

    DOEpatents

    Sease, J.D.; Harrington, F.E.

    1973-12-11

    Elongated single- and multi-region fuel elements are prepared by replacing within a cladding container a coarse fraction of fuel material which includes plutonium and uranium in the appropriate regions of the fuel element and then infiltrating with vibration a fine-sized fraction of uranium-containing microspheres throughout all interstices in the coarse material in a single loading. The fine, rigid material defines a thin annular layer between the coarse fraction and the cladding to reduce adverse mechanical and chemical interactions. (Official Gazette)

  20. Method for producing sintered ceramic, layered, circular fuel pellets

    DOEpatents

    Harlow, John L.

    1983-01-01

    A compacting die wherein the improvement comprises providing a screen in the die cavity, the screen being positioned parallel to the side walls of said die and dividing the die cavity into center and annular compartments. In addition, the use of this die in a method for producing an annular clad ceramic fuel material is disclosed.

  1. Cradle-to-Gate Life-Cycle Inventory and Impact Assessment of Wood Fuel Pellet Manufacturing from Hardwood Flooring Residues in the Southeastern United States

    Treesearch

    Daniel Reed; Richard Bergman; Jae-Woo Kim; Adam Tayler; David Harper; David Jones; Chris Knowles; Maureen E. Puettmann

    2012-01-01

    In this article, we present cradle-to-gate life-cycle inventory (LCI) data for wood fuel pellets manufactured in the Southeast United States. We surveyed commercial pellet manufacturers in 2010, collecting annual production data for 2009. Weighted-average inputs to, and emissions from, the pelletization process were determined. The pellet making unit process was...

  2. Use of solid fuel in the production of pellets with Venezuelan iron ore

    SciTech Connect

    Rodriguez, A.; Ionescu, D.; Reyes, N.; Carrasquel, A.; Murati, C.; Guzman, J.L. )

    1993-01-01

    The pellet plant of Sidor consists of a dry grinding process for the iron ore and an induration process which takes place in a travelling grate furnace. The technical personnel considered the necessity of increasing the actual levels of productivity of 417 t/h and the abrasion index of 6%. To obtain this target, the technicians developed a series of pilot tests using solid fuel in the pelletizing mixture which gave positive results in the production of fluxed pellets using Venezuelan hematitic ore. At the industrial level the results were more successful than at pilot level; the productivity and the quality of pellets improved above the design values. The amount of coke used in the mixture was 0.7% and it required a significant change in the thermal profile of the furnace. The productivity increased 22.5% the abrasion index improved by 17.0%. The energy consumption was reduced to 25%. After this successful campaign there are plans for increasing the coke addition more than 1% which will allow abrasion levels between 4.0 and 4.5%, the compression strength between 320 and 330 Kg/pellet and also increase the productivity of the plant.

  3. Techniques for chamfer and taper grinding of oxide fuel pellets (LWBR Development Program)

    SciTech Connect

    Johnson, R.G.R.; Allison, J.W.

    1981-10-01

    Floor mounted centerless grinding machines were adapted for shaping the edges of cylindrical oxide fuel pellets for the Light Water Breeder Reactor (LWBR) by plunge grinding. Edge configurations consisted of chamfers, either 0.015 inch x 45/sup 0/ or 0.006 inch x 45/sup 0/, or tapers 0.150 inch long x .0025 inch deep. Grinding was done by plunging the pellet against a shaped grinding wheel which ground both the diameter to the required size and shaped the edges of the pellet. Two plunges per pellet were required to complete the operation. Separate wheels were needed for grinding either a chamfer or a taper, the set up was adjustable to vary the size of the chamfer or taper as needed. The set up also had the flexibility to accommodate the multiple pellet lengths and diameters required by the LWBR design. Tight manufacturing tolerances in the chamfer and taper dimensions required the use of dimensional control charts and statistical sampling plans as process controls.

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

    PubMed Central

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

    2014-01-01

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

  5. Non destructive examination of UN / U-Si fuel pellets using neutrons (preliminary assessment)

    SciTech Connect

    Bourke, Mark Andrew; Vogel, Sven C.; Voit, Stewart Lancaster; Mcclellan, Kenneth James; Losko, Adrian S.; Tremsin, Anton

    2016-03-31

    Tomographic imaging and diffraction measurements were performed on nine pellets; four UN/ U Si composite formulations (two enrichment levels), three pure U3Si5 reference formulations (two enrichment levels) and two reject pellets with visible flaws (to qualify the technique). The U-235 enrichments ranged from 0.2 to 8.8 wt.%. The nitride/silicide composites are candidate compositions for use as Accident Tolerant Fuel (ATF). The monophase U3Si5 material was included as a reference. Pellets from the same fabrication batches will be inserted in the Advanced Test Reactor at Idaho during 2016. The goal of the Advanced Non-destructive Fuel Examination work package is the development and application of non-destructive neutron imaging and scattering techniques to ceramic and metallic nuclear fuels. Data reported in this report were collected in the LANSCE run cycle that started in September 2015 and ended in March 2016. Data analysis is ongoing; thus, this report provides a preliminary review of the measurements and provides an overview of the characterized samples.

  6. General-purpose heat source: Research and development program. Process evaluation, fuel pellet GF-47

    SciTech Connect

    Reimus, M.A.H.; George, T.G.

    1995-12-01

    The general-purpose heat source (GPHS) provides power for space missions by transmitting the heat of {sup 238}Pu decay to an array of thermoelectric elements. Because the potential for a launch abort or return from orbit exists for any space mission, the heat source must be designed and constructed to survive credible accident environments. Previous testing conducted in support of the Galileo and Ulysses missions has documented the response of the GPHS heat source to a variety of fragment-impact, aging, atmospheric reentry, and Earth-impact conditions. Although heat sources for previous missions were fabricated by the Westinghouse Savannah River Company (WSRC), GPHS fueled-clads required for the Cassini mission to Saturn will be fabricated by Los Alamos National Laboratory (LANL). This evaluation is part of an ongoing program to determine the similarity of GPHS fueled clads and fuel pellets fabricated at LANL to those fabricated at WSRC. Pellet GF-47, which was fabricated at LANL in late 1994, was submitted for chemical and ceramographic analysis. The results indicated that the pellet had a chemical makeup and microstructure within the range of material fabricated at WSRC in the early 1980s.

  7. FY04 Inspection Results for Wet Uruguay Fuel in L-Basin

    SciTech Connect

    VORMELKER, PHILIP

    2005-09-01

    The 2004 visual inspection of four Uruguay nuclear fuel assemblies stored in L-Basin was completed. This was the third inspection of this wet stored fuel since its arrival in the summer of 1998. Visual inspection photographs of the fuel from the previous and the recent inspections were compared and no evidence of significant corrosion was found on the individual fuel plate photographs. Fuel plates that showed areas of pitting in the cladding during the original receipt inspection were also identified during the 2004 inspection. However, a few pits were found on the non-fuel aluminum clamping plates that were not visible during the original and 2001 inspections.

  8. Advanced Pellet Cladding Interaction Modeling Using the US DOE CASL Fuel Performance Code: Peregrine

    SciTech Connect

    Jason Hales; Various

    2014-06-01

    The US DOE’s Consortium for Advanced Simulation of LWRs (CASL) program has undertaken an effort to enhance and develop modeling and simulation tools for a virtual reactor application, including high fidelity neutronics, fluid flow/thermal hydraulics, and fuel and material behavior. The fuel performance analysis efforts aim to provide 3-dimensional capabilities for single and multiple rods to assess safety margins and the impact of plant operation and fuel rod design on the fuel thermomechanical- chemical behavior, including Pellet-Cladding Interaction (PCI) failures and CRUD-Induced Localized Corrosion (CILC) failures in PWRs. [1-3] The CASL fuel performance code, Peregrine, is an engineering scale code that is built upon the MOOSE/ELK/FOX computational FEM framework, which is also common to the fuel modeling framework, BISON [4,5]. Peregrine uses both 2-D and 3-D geometric fuel rod representations and contains a materials properties and fuel behavior model library for the UO2 and Zircaloy system common to PWR fuel derived from both open literature sources and the FALCON code [6]. The primary purpose of Peregrine is to accurately calculate the thermal, mechanical, and chemical processes active throughout a single fuel rod during operation in a reactor, for both steady state and off-normal conditions.

  9. Advanced Pellet-Cladding Interaction Modeling using the US DOE CASL Fuel Performance Code: Peregrine

    SciTech Connect

    Montgomery, Robert O.; Capps, Nathan A.; Sunderland, Dion J.; Liu, Wenfeng; Hales, Jason; Stanek, Chris; Wirth, Brian D.

    2014-06-15

    The US DOE’s Consortium for Advanced Simulation of LWRs (CASL) program has undertaken an effort to enhance and develop modeling and simulation tools for a virtual reactor application, including high fidelity neutronics, fluid flow/thermal hydraulics, and fuel and material behavior. The fuel performance analysis efforts aim to provide 3-dimensional capabilities for single and multiple rods to assess safety margins and the impact of plant operation and fuel rod design on the fuel thermo-mechanical-chemical behavior, including Pellet-Cladding Interaction (PCI) failures and CRUD-Induced Localized Corrosion (CILC) failures in PWRs. [1-3] The CASL fuel performance code, Peregrine, is an engineering scale code that is built upon the MOOSE/ELK/FOX computational FEM framework, which is also common to the fuel modeling framework, BISON [4,5]. Peregrine uses both 2-D and 3-D geometric fuel rod representations and contains a materials properties and fuel behavior model library for the UO2 and Zircaloy system common to PWR fuel derived from both open literature sources and the FALCON code [6]. The primary purpose of Peregrine is to accurately calculate the thermal, mechanical, and chemical processes active throughout a single fuel rod during operation in a reactor, for both steady state and off-normal conditions.

  10. Pellet cladding mechanical interactions of ceramic claddings fuels under light water reactor conditions

    NASA Astrophysics Data System (ADS)

    Li, Bo-Shiuan

    Ceramic materials such as silicon carbide (SiC) are promising candidate materials for nuclear fuel cladding and are of interest as part of a potential accident tolerant fuel design due to its high temperature strength, dimensional stability under irradiation, corrosion resistance, and lower neutron absorption cross-section. It also offers drastically lower hydrogen generation in loss of coolant accidents such as that experienced at Fukushima. With the implementation of SiC material properties to the fuel performance code, FRAPCON, performances of the SiC-clad fuel are compared with the conventional Zircaloy-clad fuel. Due to negligible creep and high stiffness, SiC-clad fuel allows gap closure at higher burnup and insignificant cladding dimensional change. However, severe degradation of SiC thermal conductivity with neutron irradiation will lead to higher fuel temperature with larger fission gas release. High stiffness of SiC has a drawback of accumulating large interfacial pressure upon pellet-cladding mechanical interactions (PCMI). This large stress will eventually reach the flexural strength of SiC, causing failure of SiC cladding instantly in a brittle manner instead of the graceful failure of ductile metallic cladding. The large interfacial pressure causes phenomena that were previously of only marginal significance and thus ignored (such as creep of the fuel) to now have an important role in PCMI. Consideration of the fuel pellet creep and elastic deformation in PCMI models in FRAPCON provide for an improved understanding of the magnitude of accumulated interfacial pressure. Outward swelling of the pellet is retarded by the inward irradiation-induced creep, which then reduces the rate of interfacial pressure buildup. Effect of PCMI can also be reduced and by increasing gap width and cladding thickness. However, increasing gap width and cladding thickness also increases the overall thermal resistance which leads to higher fuel temperature and larger fission

  11. WHIST transport analysis of high neutron production, ICRH heated, pellet fueled jet plasmas

    SciTech Connect

    Houlberg, W.A.; Milora, S.L.; Tolliver, J.S.; Phillips, C.K.

    1988-01-01

    The WHIST 1-1/2-D predictive transport code is used to model the particle and energy transport of JET pellet-fueled, ICRH-heated plasmas. Pellet injection during the current rise phase was used to produce strong central peaking of the particle density followed by central ICRH heating and led to transient period of enhanced confinement. The evolution of the density profile as well as the electron and ion temperature profiles and strong ICRH heating conditions are examined during this period of enhanced confinement in the context of models for particle and energy transport. Because WHIST is a predictive transport code, it requires models for particle and energy sources and transport coefficients. The analysis procedure thus consists of modeling the particle source terms (pellets, gas, and recycled neutrals), energy source terms (ohmic and ICRH heating), and energy loss terms (primarily radiation), and varying the transport models until the best qualitative and quantitative agreement is obtained between calculated and observed quantities. We find that plasma behavior is well described during the first second of ICRH heating following pellet injection by the same transport coefficients that describe the ohmic plasma. The distinction between electron and ion thermal losses depends on the relative heating rates of electrons and ions as determined by the ICRH model, as well as the radiation losses. 10 refs., 4 figs.

  12. Pelletization and encapsulation of general purpose heat source (GPHS) fueled clads for future space missions

    NASA Astrophysics Data System (ADS)

    Barklay, Chadwick D.; Miller, Roger G.; Malikh, Y.; Kalinovsky, A.; Aldoshin, A.

    1996-03-01

    Mankind must continue to explore the universe in order to gain a better understanding of how we relate to it and how we can best use its resources to our benefit. Because of the significant costs of this type of exploration, it can more effectively be accomplished through an international team effort. This unified effort must include the design, planning, and execution phases of future space missions, extending down to such activities as the processing, pelletization, and encapsulation of the fuel that will be used to support the spacecraft electrical power generation systems. Over the last 30 years, radioisotopes have provided heat from which electrical power is generated. For space missions, the isotope of choice has generally been 238PuO2, its long half-life making it ideal for supplying power to remote satellites and spacecraft like the Voyager, Pioneer, and Viking missions, as well as the recently launched Galileo and Ulysses missions, and the presently planned Cassini mission. Electric power for future space missions will be provided by either radioisotopic thermoelectric generators (RTG), radioisotope thermophotovoltaic systems (RTPV), radioisotope Stirling systems or a combination of these. However, all of the aforementioned systems will be thermally driven by General-Purpose Heat Source (GPHS) fueled clads in some configuration. Each GPHS fueled clad contains a 150-gram pellet of 238PuO2, and each pellet is encapsulated within an iridium-alloy shell. Historically, the fabrication of the iridium-alloy shells has been performed at EG&G Mound, and Oak Ridge National Laboratory, and the girth welding of the GPHS capsules has been performed at Westinghouse Savannah River Corporation, and Los Alamos National Laboratory. This paper describes a cost effective alternative method for the production of GPHS capsules. Fundamental considerations such as the potential production options, the associated support activities, and the methodology to transport the welded

  13. Pelletization and encapsulation of general purpose heat source (GPHS) fueled clads for future space missions

    SciTech Connect

    Barklay, C.D.; Miller, R.G.; Malikh, Y.; Kalinovsky, A.; Aldoshin, A.

    1996-03-01

    Because of the significant costs of space exploration, it can more effectively be accomplished through an international team effort. This unified effort must include the design, planning, and execution phases of future space missions, extending down to such activities as the processing, pelletization, and encapsulation of the fuel that will be used to support the spacecraft electrical power generation systems. Over the last 30 years, radioisotopes have provided heat from which electrical power is generated. For space missions, the isotope of choice has generally been {sup 238}PuO{sub 2}, its long half-life making it ideal for supplying power to remote satellites and spacecraft like the Voyager, Pioneer, and Viking missions, as well as the recently launched Galileo and Ulysses missions, and the presently planned Cassini mission. Electric power for future space missions will be provided by either radioisotopic thermoelectric generators (RTG), radioisotope thermophotovoltaic systems (RTPV), radioisotope Stirling systems or a combination of these. However, all of the aforementioned systems will be thermally driven by General-Purpose Heat Source (GPHS) fueled clads in some configuration. Each GPHS fueled clad contains a 150-gram pellet of {sup 238}PuO{sub 2}, and each pellet is encapsulated within an iridium-alloy shell. Historically, the fabrication of the iridium-alloy shells has been performed at EG&G Mound, and Oak Ridge National Laboratory, and the girth welding of the GPHS capsules has been performed at Westinghouse Savannah River Corporation, and Los Alamos National Laboratory. This paper describes a cost effective alternative method for the production of GPHS capsules. Fundamental considerations such as the potential production options, the associated support activities, and the methodology to transport the welded fueled clads are discussed. (Abstract Truncated)

  14. Nondestructive inspection of General Purpose Heat Source (GPHS) fueled clad girth welds

    SciTech Connect

    Reimus, M. A. H.; George, T. G.; Lynch, C.; Padilla, M.; Moniz, P.; Guerrero, A.; Moyer, M. W.; Placr, A.

    1998-01-15

    The General-Purpose Heat Source (GPHS) provides power for space missions by transmitting the heat of {sup 238}Pu decay to an array of thermoelectric elements. The GPHS is fabricated using an iridium-alloy to contain the {sup 238}PuO{sub 2} fuel pellet. GPHS capsules will be utilized in the upcoming Cassini mission to explore Saturn and its moons. The physical integrity of the girth weld is important to mission safety and performance. Because past experience had revealed a potential for initiation of small cracks in the girth weld overlap zone, a nondestructive inspection of each capsule weld is required. An ultrasonic method was used to inspect the welds of capsules fabricated for the Galileo mission. The instrument, transducer, and method used were state of the art at the time (early 1980s). The ultrasonic instrumentation and methods used to inspect the Cassini GPHSs was significantly upgraded from those used for the Galileo mission. GPHSs that had ultrasonic reflectors in excess of the reject specification level were subsequently inspected with radiography to provide additional engineering data used to accept/reject the heat source. This paper describes the Galileo-era ultrasonic instrumentation and methods and the subsequent upgrades made to support testing of Cassini GPHSs. Also discussed is the data obtained from radiographic examination and correlation to ultrasonic examination results.

  15. Remote inspection of the IFSF spent fuel storage rack

    SciTech Connect

    Uldrich, E.D.

    1996-05-01

    The Irradiated Fuel Storage Facility (IFSF) is a dry storage facility for spent nuclear fuels located at the Idaho Chemical Processing Plant; it was constructed in the 1970`s specifically for the Fort Saint Vrain spent reactor fuels. Currently, it is being used for various spent fuels. It was not known if IFSF would met current DOE seismic criteria, so re-analysis was started, with the rack being analyzed first. The rack was inspected to determine the as-built condition. LazrLyne and VideoRuler were used in lieu of using a tape measure with the camera. It was concluded that when a visual inspection shows widely varying weld sizes, the engineer has to use all resources available to determine the most probable specified weld sizes.

  16. LIBS Spectral Data for a Mixed Actinide Fuel Pellet Containing Uranium, Plutonium, Neptunium and Americium

    SciTech Connect

    Judge, Elizabeth J.; Berg, John M.; Le, Loan A.; Lopez, Leon N.; Barefield, James E.

    2012-06-18

    Laser-induced breakdown spectroscopy (LIBS) was used to analyze a mixed actinide fuel pellet containing 75% UO{sub 2}/20% PuO{sub 2}/3% AmO{sub 2}/2% NpO{sub 2}. The preliminary data shown here is the first report of LIBS analysis of a mixed actinide fuel pellet, to the authors knowledge. The LIBS spectral data was acquired in a plutonium facility at Los Alamos National Laboratory where the sample was contained within a glove box. The initial installation of the glove box was not intended for complete ultraviolet (UV), visible (VIS) and near infrared (NIR) transmission, therefore the LIBS spectrum is truncated in the UV and NIR regions due to the optical transmission of the window port and filters that were installed. The optical collection of the emission from the LIBS plasma will be optimized in the future. However, the preliminary LIBS data acquired is worth reporting due to the uniqueness of the sample and spectral data. The analysis of several actinides in the presence of each other is an important feature of this analysis since traditional methods must chemically separate uranium, plutonium, neptunium, and americium prior to analysis. Due to the historic nature of the sample fuel pellet analyzed, the provided sample composition of 75% UO{sub 2}/20% PuO{sub 2}/3% AmO{sub 2}/2% NpO{sub 2} cannot be confirm without further analytical processing. Uranium, plutonium, and americium emission lines were abundant and easily assigned while neptunium was more difficult to identify. There may be several reasons for this observation, other than knowing the exact sample composition of the fuel pellet. First, the atomic emission wavelength resources for neptunium are limited and such techniques as hollow cathode discharge lamp have different dynamics than the plasma used in LIBS which results in different emission spectra. Secondly, due to the complex sample of four actinide elements, which all have very dense electronic energy levels, there may be reactions and

  17. 14 CFR 91.1507 - Fuel tank system inspection program.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Airworthiness and Safety Improvements § 91.1507 Fuel tank system inspection program. (a) Except as provided in... later increase in capacity, have— (1) A maximum type-certificated passenger capacity of 30 or more, or...) Illyushin Aviation IL 96T (6) Bristol Aircraft Britannia 305 (7) Handley Page Herald Type 300 (8) Avions...

  18. 14 CFR 125.507 - Fuel tank system inspection program.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... CAPACITY OF 6,000 POUNDS OR MORE; AND RULES GOVERNING PERSONS ON BOARD SUCH AIRCRAFT Continued Airworthiness and Safety Improvements § 125.507 Fuel tank system inspection program. (a) Except as provided in... later increase in capacity, have— (1) A maximum type-certificated passenger capacity of 30 or more, or...

  19. 14 CFR 125.507 - Fuel tank system inspection program.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... CAPACITY OF 6,000 POUNDS OR MORE; AND RULES GOVERNING PERSONS ON BOARD SUCH AIRCRAFT Continued Airworthiness and Safety Improvements § 125.507 Fuel tank system inspection program. (a) Except as provided in... later increase in capacity, have— (1) A maximum type-certificated passenger capacity of 30 or more, or...

  20. 14 CFR 91.1507 - Fuel tank system inspection program.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Airworthiness and Safety Improvements § 91.1507 Fuel tank system inspection program. (a) Except as provided in... later increase in capacity, have— (1) A maximum type-certificated passenger capacity of 30 or more, or...) Illyushin Aviation IL 96T (6) Bristol Aircraft Britannia 305 (7) Handley Page Herald Type 300 (8) Avions...

  1. Production of a pellet fuel from Illinois coal fines. Technical report, March 1--May 31, 1995

    SciTech Connect

    Rapp, D.; Lytle, J.

    1995-12-31

    The primary goal of this research is to produce a pellet fuel from low-sulfur Illinois coal fines which could burn with emissions of less than 1.8 lbs SO{sub 2}/10{sup 6} Btu in stoker-fired boilers. The significance of 1.8 lbs SO{sub 2}/10{sup 6} Btu is that in the Chicago (9 counties) and St. Louis (2 counties) metropolitan areas, industrial users of coal currently must comply with this level of emissions. For this effort, we will be investigating the use of fines from two Illinois mines which currently mine relatively low-sulfur reserves and that discard their fines fraction (minus 100 mesh). The research will involve investigation of multiple unit operations including column flotation, filtration and pellet production. The end result of the effort will allow for an evaluation of the commercial viability of the approach. Previously it has been decided that corn starch would be used as binder and a roller-and-die mill would be used for pellet manufacture. A quality starch binder has been identified and tested. To potentially lower binder costs, a starch that costs about 50% of the high quality starch was tested. Results indicate that the lower cost starch will not lower binder cost because more is required to produce a comparable quality pellet. Also, a petroleum in water emulsion was evaluated as a potential binder. The compound seemed to have adhesive properties but was found to be a poor binder. Arrangements have been made to collect a waste slurry from the mine previously described.

  2. Effect of fuel zinc content on toxicological responses of particulate matter from pellet combustion in vitro.

    PubMed

    Uski, O; Jalava, P I; Happo, M S; Torvela, T; Leskinen, J; Mäki-Paakkanen, J; Tissari, J; Sippula, O; Lamberg, H; Jokiniemi, J; Hirvonen, M-R

    2015-04-01

    Significant amounts of transition metals such as zinc, cadmium and copper can become enriched in the fine particle fraction during biomass combustion with Zn being one of the most abundant transition metals in wood combustion. These metals may have an important role in the toxicological properties of particulate matter (PM). Indeed, many epidemiological studies have found associations between mortality and PM Zn content. The role of Zn toxicity on combustion PM was investigated. Pellets enriched with 170, 480 and 2300 mg Zn/kg of fuel were manufactured. Emission samples were generated using a pellet boiler and the four types of PM samples; native, Zn-low, Zn-medium and Zn-high were collected with an impactor from diluted flue gas. The RAW 264.7 macrophage cell line was exposed for 24h to different doses (15, 50,150 and 300 μg ml(-1)) of the emission samples to investigate their ability to cause cytotoxicity, to generate reactive oxygen species (ROS), to altering the cell cycle and to trigger genotoxicity as well as to promote inflammation. Zn enriched pellets combusted in a pellet boiler produced emission PM containing ZnO. Even the Zn-low sample caused extensive cell cycle arrest and there was massive cell death of RAW 264.7 macrophages at the two highest PM doses. Moreover, only the Zn-enriched emission samples induced a dose dependent ROS response in the exposed cells. Inflammatory responses were at a low level but macrophage inflammatory protein 2 reached a statistically significant level after exposure of RAW 264.7 macrophages to ZnO containing emission particles. ZnO content of the samples was associated with significant toxicity in almost all measured endpoints. Thus, ZnO may be a key component producing toxicological responses in the PM emissions from efficient wood combustion. Zn as well as the other transition metals, may contribute a significant amount to the ROS responses evoked by ambient PM.

  3. Development and evaluation of lime enhanced refuse-derived fuel (RDF) pellets

    SciTech Connect

    Ohlsson, O.O.

    1996-12-31

    The disposal of municipal solid waste (MSW) is of increasing concern for municipalities and state governments throughout the US. There are two technologies currently in use for the combustion of MSW: (1) mass burning in which unprocessed MSW is burned in a heat recovery furnace, and (2) a refuse-derived fuel (RDF) product, which consists of the organic (combustible) fraction of MSW which has been processed to produce a more homogeneous fuel product than raw MSW. The RDF is either marketed to outside users or combusted on-site in a dedicated or existing furnace. In an attempt to alleviate the problems encountered with RDF as a feedstock, Argonne National Laboratory (ANL) and the University of North Texas (UNT) under the sponsorship of the US Department of Energy (DOE) began a multi-phase research study to investigate the development of a low-cost binder that would improve the quality of RDF pellets.

  4. Synthesis and Analysis of Alpha Silicon Carbide Components for Encapsulation of Fuel Rods and Pellets

    SciTech Connect

    Kevin M. McHugh; John E. Garnier; George W. Griffith

    2011-09-01

    The chemical, mechanical and thermal properties of silicon carbide (SiC) along with its low neutron activation and stability in a radiation field make it an attractive material for encapsulating fuel rods and fuel pellets. The alpha phase (6H) is particularly stable. Unfortunately, it requires very high temperature processing and is not readily available in fibers or near-net shapes. This paper describes an investigation to fabricate a-SiC as thin films, fibers and near-net-shape products by direct conversion of carbon using silicon monoxide vapor at temperatures less than 1700 C. In addition, experiments to nucleate the alpha phase during pyrolysis of polysilazane, are also described. Structure and composition were characterized using scanning electron microscopy, energy dispersive spectroscopy and X-ray diffraction. Preliminary tensile property analysis of fibers was also performed.

  5. Simulating Dynamic Fracture in Oxide Fuel Pellets Using Cohesive Zone Models

    SciTech Connect

    R. L. Williamson

    2009-08-01

    It is well known that oxide fuels crack during the first rise to power, with continued fracture occurring during steady operation and especially during power ramps or accidental transients. Fractures have a very strong influence on the stress state in the fuel which, in turn, drives critical phenomena such as fission gas release, fuel creep, and eventual fuel/clad mechanical interaction. Recently, interest has been expressed in discrete fracture methods, such as the cohesive zone approach. Such models are attractive from a mechanistic and physical standpoint, since they reflect the localized nature of cracking. The precise locations where fractures initiate, as well as the crack evolution characteristics, are determined as part of the solution. This paper explores the use of finite element cohesive zone concepts to predict dynamic crack behavior in oxide fuel pellets during power-up, steady operation, and power ramping. The aim of this work is first to provide an assessment of cohesive zone models for application to fuel cracking and explore important numerical issues associated with this fracture approach. A further objective is to provide basic insight into where and when cracks form, how they interact, and how cracking effects the stress field in a fuel pellet. The ABAQUS commercial finite element code, which includes powerful cohesive zone capabilities, was used for this study. Fully-coupled thermo-mechanical behavior is employed, including the effects of thermal expansion, swelling due to solid and gaseous fission products, and thermal creep. Crack initiation is determined by a temperature-dependent maximum stress criterion, based on measured fracture strengths for UO2. Damage evolution is governed by a traction-separation relation, calibrated to data from temperature and burn-up dependent fracture toughness measurements. Numerical models are first developed in 2D based on both axisymmetric (to explore axial cracking) and plane strain (to explore radial

  6. Bending testing and characterization of surrogate nuclear fuel rods made of Zircaloy-4 cladding and aluminum oxide pellets

    NASA Astrophysics Data System (ADS)

    Wang, Hong; Wang, Jy-An John

    2016-10-01

    Behavior of surrogate nuclear fuel rods made of Zircaloy-4 (Zry-4) cladding with alumina pellets under reversed cyclic bending was studied. Tests were performed under load or moment control at 5 Hz. The surrogate rods fractured under moment amplitudes greater than 10.16 Nm with fatigue lives between 2.4 × 103 and 2.2 × 106 cycles. Fatigue response of Zry-4 cladding was characterized by using flexural rigidity. Degradation of flexural rigidity was shown to depend on the moment and the prefatigue condition of specimens. Pellet-to-pellet interface (PPI), pellet-to-cladding interface (PCI), and pellet condition affect surrogate rod failure. Both debonding of PPI/PCI and pellet fracturing contribute to surrogate rod bending fatigue. The effect of sensor spacing on curvature measurement using three-point deflections was studied; the method based on effective gauge length is effective in sensor spacing correction. The database developed and the understanding gained in this study can serve as input to analysis of SNF (spent nuclear fuel) vibration integrity.

  7. Enhanced thermal conductivity of uranium dioxide-silicon carbide composite fuel pellets prepared by Spark Plasma Sintering (SPS)

    NASA Astrophysics Data System (ADS)

    Yeo, S.; Mckenna, E.; Baney, R.; Subhash, G.; Tulenko, J.

    2013-02-01

    Uranium dioxide (UO2)-10 vol% silicon carbide (SiC) composite fuel pellets were produced by oxidative sintering and Spark Plasma Sintering (SPS) at a range of temperatures from 1400 to 1600 °C. Both SiC whiskers and SiC powder particles were utilized. Oxidative sintering was employed over 4 h and the SPS sintering was employed only for 5 min at the highest hold temperature. It was noted that composite pellets sintered by SPS process revealed smaller grain size, reduced formation of chemical products, higher density, and enhanced interfacial contact compared to the pellets made by oxidative sintering. For given volume of SiC, the pellets with powder particles yielded a smaller grain size than pellets with SiC whiskers. Finally thermal conductivity measurements at 100 °C, 500 °C, and 900 °C revealed that SPS sintered UO2-SiC composites exhibited an increase of up to 62% in thermal conductivity compared to UO2 pellets, while the oxidative sintered composite pellets revealed significantly inferior thermal conductivity values. The current study points to the improved processing capabilities of SPS compared to oxidative sintering of UO2-SiC composites.

  8. 26 CFR 48.4082-3 - Diesel fuel and kerosene; visual inspection devices. [Reserved

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 16 2010-04-01 2010-04-01 true Diesel fuel and kerosene; visual inspection devices. 48.4082-3 Section 48.4082-3 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY..., Tread Rubber, and Taxable Fuel Taxable Fuel § 48.4082-3 Diesel fuel and kerosene; visual inspection...

  9. Emissions of carbon monoxide and carbon dioxide from uncompressed and pelletized biomass fuel burning in typical household stoves in China

    NASA Astrophysics Data System (ADS)

    Wei, Wen; Zhang, Wei; Hu, Dan; Ou, Langbo; Tong, Yindong; Shen, Guofeng; Shen, Huizhong; Wang, Xuejun

    2012-09-01

    Carbon dioxide (CO2) and carbon monoxide (CO) impact climate change and human health. The uncertainties in emissions inventories of CO2 and CO are primarily due to the large variation in measured emissions factors (EFs), especially to the lack of EFs from developing countries. China's goals of reducing CO2 emissions require a maximum utilization of biomass fuels. Pelletized biomass fuels are well suited for the residential biomass market, providing possibilities of more automated and optimized systems with higher modified combustion efficiency (MCE) and less products from incomplete combustion. However, EFs of CO2 and CO from pellet biomass fuels are seldom reported, and a comparison to conventional uncompressed biomass fuels has never been conducted. Therefore, the objectives of this study were to experimentally determine the CO2 and CO EFs from uncompressed biomass (i.e., firewood and crop residues) and biomass pellets (i.e., pine wood pellet and corn straw pellet) under real residential applications and to compare the influences of fuel properties and combustion conditions on CO2 and CO emissions from the two types of biomass fuels. For the uncompressed biomass examples, the CO2 and CO EFs were 1649.4 ± 35.2 g kg-1 and 47.8 ± 8.9 g kg-1, respectively, for firewood and 1503.2 ± 148.5 g kg-1 and 52.0 ± 14.2 g kg-1, respectively, for crop residues. For the pellet biomass fuel examples, the CO2 and CO EFs were 1708.0 ± 3.8 g kg-1 and 4.4 ± 2.4 g kg-1, respectively, for pellet pine and 1552.1 ± 16.3 g kg-1 and 17.9 ± 10.2 g kg-1, respectively, for pellet corn. In rural China areas during 2007, firewood and crop residue burning produced 721.7 and 23.4 million tons of CO2 and CO, respectively.

  10. Demonstration of fuel resistant to pellet-cladding interaction: Phase 2. Second semiannual report, July-December 1979

    SciTech Connect

    Rosenbaum, H.S.

    1980-03-01

    This program has as its ultimate objective the demonstration of an advanced fuel design that is resistant to the failure mechanism known as fuel pellet-cladding interaction (PCI). Two fuel concepts are being developed for possible demonstration within this program: (a) Cu-barrier fuel and (b) Zr-liner fuel. In the current report period the nuclear design of the demonstration was begun. The design calls for 132 bundles of barrier fuel to be inserted into the core of Quad Cities Unit 2 at the beginning of Cycle 6. Laboratory and in-reactor tests were started to evaluate the stability of Zr-liner fuel which remains in service after a defect has occurred which allows water to enter the rod. Results to date on intentionally defected fuel indicate that the Zr-liner fuel is not rapidly degraded despite ingress of water.

  11. Production of a pellet fuel from Illinois coal mines. Quarterly report, 1 December 1994--28 February 1995

    SciTech Connect

    Rapp, D.; Lytle, J.; Berger, R.; Ho, Ken

    1995-12-31

    The goal of this research is to produce a pellet fuel from low-sulfur Illinois coal fines which could burn with emissions of less than 1.8 lbs SO{sub 2}/10{sup 6} Btu in stoker-fired boilers. The significance of 1.8 lbs SO{sub 2}/10{sup 6} Btu is that in the Chicago (9 counties) and St. Louis (2 counties) metropolitan areas, industrial users of coal currently must comply with this level of emissions. Stokers are an attractive market for pellets because pellets are well-suited for this application and because western coal is not a competitor in the stoker market. Compliance stoker fuels come from locations such as Kentucky and West Virginia and the price for fuels from these locations is high relative to the current price of Illinois coal. This market offers the most attractive near-term economic environment for commercialization of pelletization technology. For this effort, we will be investigating the use of fines from two Illinois mines which currently mine relatively low-sulfur reserves and that discard their fines fraction (minus 100 mesh). The research will involve investigation of multiple unit operations including column flotation, filtration and pellet production. The end result of the effort will allow for an evaluation of the commercial viability of the approach.

  12. Evaluation of micro-homogeneity in plutonium based nuclear reactor fuel pellets by alpha-autoradiography technique

    NASA Astrophysics Data System (ADS)

    Baghra, Chetan; Sathe, D. B.; Sharma, Jitender; Walinjkar, Nilima; Behere, P. G.; Afzal, Mohd; Kumar, Arun

    2015-12-01

    Alpha-autoradiography is a fast and non-destructive technique which is used at Advanced Fuel Fabrication Facility (India) to evaluate micro-homogeneity of plutonium in uranium and plutonium mixed oxide (U-Pu)O2 fuel pellets fabricated for both thermal and fast breeder reactors. In this study, various theoretical calculations to understand effect of alpha autoradiography process parameters and limiting conditions for measuring micro-homogeneity of plutonium in the pellets having different concentrations of plutonium were reported. Experiments were carried out to establish the procedure to evaluate micro-homogeneity of plutonium in (U-x%Pu)O2 pellets where x varies from 0.4 to 44% and to measure the size of agglomerates, if any, present in the pellet. An attempt had been made to measure plutonium content in the agglomerate using alpha-autoradiography. This study can also be useful for carrying out alpha-autoradiography of spent fuel pellets during post-irradiation examination.

  13. Inspection Head Design for the In-Service Inspection of Fuel Channels of Pressurized Heavy Water Reactors

    SciTech Connect

    Haruray, Amit Kumar; Veerapur, R.D.; Puri, R.K.; Singh, Manjit

    2006-07-01

    This paper discusses the challenges associated with the mechanical design of Inspection Head for the in-service inspection (ISI) of fuel channels of Indian Pressurized Heavy Water Reactors (PHWRs). ISI is carried out during shut down period in the reactor. Non Destructive Examination (NDE) of fuel channels is a mandatory requirement to acquire knowledge about the structural condition. A typical 220 MWe Reactor-core consists of 306 horizontal fuel channel assemblies (tubular in shape). There are typical design challenges due to their horizontal nature, long length (each assembly is around 9 meters long), and high radiation. Because of combined effect of above mentioned factors, these fuel channels develop permanent downward sag during service. This sag has to be negotiated by the Inspection Head. The Inspection Head houses all the NDE sensors and is deployed in the fuel channel with the help of reactor fuelling machine. It is driven inside the fuel channel by a separate external drive-system, which is capable of linearly advancing, retracting as well as rotating it all-round to achieve full-volumetric inspection. The paper also discusses an important design feature in the Inspection Head, which helps in maintaining a fixed distance between NDE sensors and the internal surface (ID) of the fuel channel, to enable us to obtain reliable and consistent inspection results. This objective is achieved with the help of two specially designed leaf-spring loaded roller modules, which are assembled in the Inspection Head at its front and rear, with NDE Sensor Module sandwiched between them. Another very important design feature in the Inspection Head helps the Spring-Loaded Roller Modules in carrying out their intended function of maintaining fixed distance despite the weight of the long drive extension links attached at the rear of Inspection Head or deviations due to any other reason. There are multiple drive extension links attached at the rear of the Inspection Head as the

  14. Handbook for Small-Scale Densified Biomass Fuel (Pellets) Manufacturing for Local Markets.

    SciTech Connect

    Folk, Richard L.; Govett, Robert L.

    1992-07-01

    Wood pellet manufacturing in the Intermountain West is a recently founded and rapidly expanding energy industry for small-scale producers. Within a three-year period, the total number of manufacturers in the region has increased from seven to twelve (Folk et al., 1988). Small-scale industry development is evolving because a supply of raw materials from small and some medium-sized primary and secondary wood processors that has been largely unused. For the residue producer considering pellet fuel manufacturing, the wastewood generated from primary products often carries a cost associated with residue disposal when methods at-e stockpiling, landfilling or incinerating. Regional processors use these methods for a variety of reasons, including the relatively small amounts of residue produced, residue form, mixed residue types, high transportation costs and lack of a local market, convenience and absence of regulation. Direct costs associated with residue disposal include the expenses required to own and operate residue handling equipment, costs for operating and maintaining a combustor and tipping fees charged to accept wood waste at public landfills. Economic and social costs related to environmental concerns may also be incurred to include local air and water quality degradation from open-air combustion and leachate movement into streams and drinking water.

  15. Detection of hydrogen gas-producing anaerobes in refuse-derived fuel (RDF) pellets.

    PubMed

    Sakka, Makiko; Kimura, Tetsuya; Ohmiya, Kunio; Sakka, Kazuo

    2005-11-01

    Recently, we reported that refuse-derived fuel (RDF) pellets contain a relatively high number of viable bacterial cells and that these bacteria generate heat and hydrogen gas during fermentation under wet conditions. In this study we analyzed bacterial cell numbers of RDF samples manufactured with different concentrations of calcium hydroxide, which is usually added to waste materials for the prevention of rotting of food wastes and the acceleration of drying of solid wastes, and determined the amount of hydrogen gas produced by them under wet conditions. Furthermore, we analyzed microflora of the RDF samples before and during fermentation by denaturing gradient gel electrophoresis of 16S rDNA followed by sequencing. We found that the RDF samples contained various kinds of clostridia capable of producing hydrogen gas.

  16. Cradle-to-Gate Life Cycle Assessment of Switchgrass Fuel Pellets Manufactured in the Southeastern United States

    Treesearch

    R. D. Bergman; D. L. Reed; A. M. Taylor; D. P. Harper; D. G. Hodges

    2015-01-01

    Developing renewable energy sources with low environmental impacts is becoming increasingly important as concerns about consuming fossil fuel sources grow. Cultivating, harvesting, drying, and densifying raw biomass feedstocks into pellets for easy handling and transport is one step forward in this endeavor. However, the corresponding environmental performances must be...

  17. Evaluation of Gas, Oil and Wood Pellet Fueled Residential Heating System Emissions Characteristics

    SciTech Connect

    McDonald, R.

    2009-12-01

    This study has measured the emissions from a wide range of heating equipment burning different fuels including several liquid fuel options, utility supplied natural gas and wood pellet resources. The major effort was placed on generating a database for the mass emission rate of fine particulates (PM 2.5) for the various fuel types studied. The fine particulates or PM 2.5 (less than 2.5 microns in size) were measured using a dilution tunnel technique following the method described in US EPA CTM-039. The PM 2.5 emission results are expressed in several units for the benefit of scientists, engineers and administrators. The measurements of gaseous emissions of O{sub 2}, CO{sub 2}, CO, NO{sub x} and SO{sub 2} were made using a combustion analyzer based on electrochemical cells These measurements are presented for each of the residential heating systems tested. This analyzer also provides a steady state efficiency based on stack gas and temperature measurements and these values are included in the report. The gaseous results are within the ranges expected from prior emission studies with the enhancement of expanding these measurements to fuels not available to earlier researchers. Based on measured excess air levels and ultimate analysis of the fuel's chemical composition the gaseous emission results are as expected and fall within the range provided for emission factors contained in the US-EPA AP 42, Emission Factors Volume I, Fifth Edition. Since there were no unexpected findings in these gaseous measurements, the bulk of the report is centered on the emissions of fine particulates, or PM 2.5. The fine particulate (PM 2.5) results for the liquid fuel fired heating systems indicate a very strong linear relationship between the fine particulate emissions and the sulfur content of the liquid fuels being studied. This is illustrated by the plot contained in the first figure on the next page which clearly illustrates the linear relationship between the measured mass of fine

  18. Bending testing and characterization of surrogate nuclear fuel rods made of Zircaloy-4 cladding and aluminum oxide pellets

    SciTech Connect

    Wang, Hong; Wang, Jy-An John

    2016-07-20

    We studied behavior of surrogate nuclear fuel rods made of Zircaloy-4 (Zry-4) cladding with alumina pellets under reversed cyclic bending. Tests were performed under load or moment control at 5 Hz, and an empirical correlation was established between rod fatigue life and amplitude of the applied moment. Fatigue response of Zry-4 cladding was further characterized by using flexural rigidity. Degradation of flexural rigidity was shown to depend on the moment applied and the prefatigue condition of specimens. Pellet-to-pellet interface (PPI), pellet-to-cladding interface (PCI), and pellet condition all affect surrogate rod failure. Bonding/debonding of PPI/PCI and pellet fracturing contribute to surrogate rod bending fatigue. Also, the effect of sensor spacing on curvature measurement using three-point deflections was studied; the method based on effective specimen gauge length is effective in sensor spacing correction. Finally, we developed the database and gained understanding in this study such that it will serve as input to analysis of SNF vibration integrity.

  19. Bending testing and characterization of surrogate nuclear fuel rods made of Zircaloy-4 cladding and aluminum oxide pellets

    DOE PAGES

    Wang, Hong; Wang, Jy-An John

    2016-07-20

    We studied behavior of surrogate nuclear fuel rods made of Zircaloy-4 (Zry-4) cladding with alumina pellets under reversed cyclic bending. Tests were performed under load or moment control at 5 Hz, and an empirical correlation was established between rod fatigue life and amplitude of the applied moment. Fatigue response of Zry-4 cladding was further characterized by using flexural rigidity. Degradation of flexural rigidity was shown to depend on the moment applied and the prefatigue condition of specimens. Pellet-to-pellet interface (PPI), pellet-to-cladding interface (PCI), and pellet condition all affect surrogate rod failure. Bonding/debonding of PPI/PCI and pellet fracturing contribute to surrogatemore » rod bending fatigue. Also, the effect of sensor spacing on curvature measurement using three-point deflections was studied; the method based on effective specimen gauge length is effective in sensor spacing correction. Finally, we developed the database and gained understanding in this study such that it will serve as input to analysis of SNF vibration integrity.« less

  20. Bending testing and characterization of surrogate nuclear fuel rods made of Zircaloy-4 cladding and aluminum oxide pellets

    SciTech Connect

    Wang, Hong; Wang, Jy-An John

    2016-07-20

    We studied behavior of surrogate nuclear fuel rods made of Zircaloy-4 (Zry-4) cladding with alumina pellets under reversed cyclic bending. Tests were performed under load or moment control at 5 Hz, and an empirical correlation was established between rod fatigue life and amplitude of the applied moment. Fatigue response of Zry-4 cladding was further characterized by using flexural rigidity. Degradation of flexural rigidity was shown to depend on the moment applied and the prefatigue condition of specimens. Pellet-to-pellet interface (PPI), pellet-to-cladding interface (PCI), and pellet condition all affect surrogate rod failure. Bonding/debonding of PPI/PCI and pellet fracturing contribute to surrogate rod bending fatigue. Also, the effect of sensor spacing on curvature measurement using three-point deflections was studied; the method based on effective specimen gauge length is effective in sensor spacing correction. Finally, we developed the database and gained understanding in this study such that it will serve as input to analysis of SNF vibration integrity.

  1. Effect of fusion reaction products heating on the volume ignition of DT and D3He fuel pellets

    NASA Astrophysics Data System (ADS)

    Khoda-Bakhsh, R.

    1996-05-01

    Laser fusion simulations are carried out for the DT and D-3He pellets by using a hydrodynamic code including heating from all charged reaction products and neutron. It is shown that, the inclusion of the side reactions and heating from all reactions products in the fuel pellets has an appreciable affect on the plasma temperature, the ICF drive energy requirement, fusion gain and the ignition conditions. The total input energy is decreased, the burn efficiency and total gain are increased compared to the results of simple volume ignition calculations.

  2. Ultrasonic inspection of rocket fuel model using laminated transducer and multi-channel step pulser

    NASA Astrophysics Data System (ADS)

    Mihara, T.; Hamajima, T.; Tashiro, H.; Sato, A.

    2013-01-01

    For the ultrasonic inspection for the packing of solid fuel in a rocket booster, an industrial inspection is difficult. Because the signal to noise ratio in ultrasonic inspection of rocket fuel become worse due to the large attenuation even using lower frequency ultrasound. For the improvement of this problem, we tried to applied the two techniques in ultrasonic inspection, one was the step function pulser system with the super wideband frequency properties and the other was the laminated element transducer. By combining these two techniques, we developed the new ultrasonic measurement system and demonstrated the advantages in ultrasonic inspection of rocket fuel model specimen.

  3. Smart Onboard Inspection of High Pressure Gas Fuel Cylinders

    SciTech Connect

    Beshears, D.L.; Starbuck, J.M.

    1999-09-27

    The use of natural gas as an alternative fuel in automotive applications is not widespread primarily because of the high cost and durability of the composite storage tanks. Tanks manufactured using carbon fiber are desirable in weight critical passenger vehicles because of the low density of carbon fiber. The high strength of carbon fiber also translates to a weight reduction because thinner wall designs are possible to withstand the internal pressure loads. However, carbon fiber composites are prone to impact damage that over the life of the storage tank may lead to an unsafe condition for the vehicle operator. A technique that potentially may be a reliable indication of developing hazardous conditions in composite fuel tanks is imbedded fiber optics. The applicability of this technique to onboard inspection is discussed and results from preliminary lab testing indicate that fiber optic sensors can reliably detect impact damage.

  4. Planning Document for Spent Nuclear Fuel (SNF) Cleanliness Inspection Process (OCRWM)

    SciTech Connect

    PITNER, A.L.

    2000-02-14

    The Fuel Retrieval System (FRS) Process Validation Procedure (Shen 1999) requires that a specified quantity of fuel processed through the Primary Cleaning Machine (PCM) be inspected for cleanliness during initial operational and process validation testing. Specifically, these inspections are performed to confirm that the PCM adequately cleans the fuel elements of canister sludge. The results of these inspections will be used to demonstrate that residual quantities of canister particulate on fuel elements loaded into Multi-Canister Overpacks (MCOs) are within projected levels used to establish safety basis limits (Sloughter 1998). The fuel inspections performed as part of the validation process will be conducted during the Hot Operations portion of the Phased Startup Initiative (PSI) of the Fuel Retrieval and Integrated Water Treatment Systems (Pajunen 1999). Hot Operations testing constitutes Phases 3 and 4 of the PSI. The fuel assemblies in all candidate canisters will be thoroughly inspected during these test phases (highly degraded fuel assemblies are exempt from inspection). During subsequent production operation of the FRS, only periodic (every tenth canister) inspections for cleanliness will be performed and documented. This document describes the specific processes and techniques that will be applied in performing the cleanliness inspections, and the methodology used to verify that the documented inspection results conform to Office of Civilian Radioactive Waste Management (OCRWM) requirements. The procedures and processes presented here are in conformance with the Quality Assurance Program Plan for Implementation of the OCRWM Quality Assurance Requirements and Description (QARD) for the Spent Nuclear Fuel Project (QAPP-OCRWM-001).

  5. Planning Document for Spent Nuclear Fuel (SNF) Cleanliness Inspection Process (OCRWM)

    SciTech Connect

    PITNER, A.L.

    2000-06-26

    The Fuel Retrieval System (FRS) Process Validation Procedure (Stegen 2000) requires that a specified quantity of fuel processed through the Primary Cleaning Machine (PCM) be inspected for cleanliness during initial operational and process validation testing. Specifically these inspections are performed to confirm that the PCM adequately cleans the fuel elements of canister sludge. The results of these inspections will be used to demonstrate that residual quantities of canister particulate on fuel elements loaded into Multi-Canister Overpacks (MCOs) are within projected levels used to establish safety basis limits (Sloughter 2000). The fuel inspections performed as part of the validation process will be conducted during the Hot Operations portion of the Phased Startup Initiative (PSI) of the Fuel Retrieval and Integrated Water Treatment Systems (Pajunen 2000). Hot Operations testing constitutes Phases 3 and 4 of PSI. The fuel assemblies in all candidate canisters will be thoroughly inspected during these test phases (highly degraded fuel assemblies that qualify as scrap are exempt from inspection). During subsequent production operation of the FRS, only periodic inspections for cleanliness will be performed and documented. This document describes the specific processes and techniques that will be applied in performing the cleanliness inspections, and the methodology used to verify that the documented inspection results conform to Office of Civilian Radioactive Waste Management (OCRWM) requirements. The procedures and processes presented here are in conformance with the Quality Assurance Program Plan for Implementation of the OCRWM Quality Assurance Requirements and Description (QARD) for the Spent Nuclear Fuel Project (QAPP-OCRWM-001).

  6. Modeling of Selected Ceramic Processing Parameters Employed in the Fabrication of 238PuO 2 Fuel Pellets

    NASA Astrophysics Data System (ADS)

    Brockman, R. A.; Kramer, D. P.; Barklay, C. D.; Cairns-Gallimore, D.; Brown, J. L.; Huling, J. C.; Van Pelt, C. E.

    Recent deep space missions utilize the thermal output of the radioisotope plutonium-238 as the fuel in the thermal to electrical power system. Since the application of plutonium in its elemental state has several disadvantages, the fuel employed in these deep space power systems is typically in the oxide form such as plutonium-238 dioxide (238PuO2). As an oxide, the processing of the plutonium dioxide into fuel pellets is performed via "classical" ceramic processing unit operations such as sieving of the powder, pressing, sintering, etc. Modeling of these unit operations can be beneficial in the understanding and control of processing parameters with the goal of further enhancing the desired characteristics of the 238PuO2 fuel pellets. A finite element model has been used to help identify the time-temperature-stress profile within a pellet during a furnace operation taking into account that 238PuO2 itself has a significant thermal output. Results of the modeling efforts will be discussed.

  7. Modeling of selected ceramic processing parameters employed in the fabrication of 238PuO2 fuel pellets

    DOE PAGES

    Brockman, R. A.; Kramer, D. P.; Barklay, C. D.; ...

    2011-10-01

    Recent deep space missions utilize the thermal output of the radioisotope plutonium-238 as the fuel in the thermal to electrical power system. Since the application of plutonium in its elemental state has several disadvantages, the fuel employed in these deep space power systems is typically in the oxide form such as plutonium-238 dioxide (238PuO2). As an oxide, the processing of the plutonium dioxide into fuel pellets is performed via ''classical'' ceramic processing unit operations such as sieving of the powder, pressing, sintering, etc. Modeling of these unit operations can be beneficial in the understanding and control of processing parameters withmore » the goal of further enhancing the desired characteristics of the 238PuO2 fuel pellets. A finite element model has been used to help identify the time-temperature-stress profile within a pellet during a furnace operation taking into account that 238PuO2 itself has a significant thermal output. The results of the modeling efforts will be discussed.« less

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

    NASA Astrophysics Data System (ADS)

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

    2017-08-01

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

  9. Development of Innovative Accident Tolerant High Thermal Conductivity UO2-Diamond Composite Fuel Pellets

    SciTech Connect

    Tulenko, James; Subhash, Ghatu

    2016-01-01

    The University of Florida (UF) evaluated a composite fuel consisting of UO2 powder mixed with diamond micro particles as a candidate as an accident-tolerant fuel (ATF). The research group had previous extensive experience researching with diamond micro particles as an addition to reactor coolant for improved plant thermal performance. The purpose of this research work was to utilize diamond micro particles to develop UO2-Diamond composite fuel pellets with significantly enhanced thermal properties, beyond that already being measured in the previous UF research projects of UO2 – SiC and UO2 – Carbon Nanotube fuel pins. UF is proving with the current research results that the addition of diamond micro particles to UO2 may greatly enhanced the thermal conductivity of the UO2 pellets producing an accident-tolerant fuel. The Beginning of life benefits have been proven and fuel samples are being irradiated in the ATR reactor to confirm that the thermal conductivity improvements are still present under irradiation.

  10. Application of railgun principle to high-velocity hydrogen pellet injection for magnetic fusion reactor fueling

    SciTech Connect

    Kim, K.; Zhang, J.

    1992-01-01

    Three separate papers are included which report research progress during this period: (1) A new railgun configuration with perforated sidewalls, (2) development of a fuseless small-bore railgun for injection of high-speed hydrogen pellets into magnetically confined plasmas, and (3) controls and diagnostics on a fuseless railgun for solid hydrogen pellet injection.

  11. Effects of pellet microstructure on irradiation behavior of UO 2 fuel

    NASA Astrophysics Data System (ADS)

    Yuda, R.; Harada, H.; Hirai, M.; Hosokawa, T.; Une, K.; Kashibe, S.; Shimizu, S.; Kubo, T.

    1997-09-01

    In-reactor tests and post-irradiation examinations (PIEs) were performed for standard and large-grained pellets with and without additives being soluble in a matrix and/or precipitated in a grain boundary, to confirm the effects of large grain structure on decreasing fission gas release (FGR) and swelling and to evaluate the influence of the additives in the matrix/grain boundary on them. The standard and large-grained pellets were loaded into small-diameter rods equipped with a pressure gauge. These rods were irradiated to about 60 GWd/t U at a linear heat rate of about 30-40 kW/m in the Halden reactor and then subjected to PIEs. Large-grained pellets showed a smaller FGR compared with standard pellets. Post-irradiation annealing tests suggested that swelling during transient power was decreased for large-grained pellets, except for those with additive enhancing cation diffusion.

  12. Reductions in emissions of carbonaceous particulate matter and polycyclic aromatic hydrocarbons from combustion of biomass pellets in comparison with raw fuel burning.

    PubMed

    Shen, Guofeng; Tao, Shu; Wei, Siye; Zhang, Yanyan; Wang, Rong; Wang, Bin; Li, Wei; Shen, Huizhong; Huang, Ye; Chen, Yuanchen; Chen, Han; Yang, Yifeng; Wang, Wei; Wei, Wen; Wang, Xilong; Liu, Wenxing; Wang, Xuejun; Masse Simonich, Staci L y

    2012-06-05

    Biomass pellets are emerging as a cleaner alternative to traditional biomass fuels. The potential benefits of using biomass pellets include improving energy utilization efficiency and reducing emissions of air pollutants. To assess the environmental, climate, and health significance of replacing traditional fuels with biomass pellets, it is critical to measure the emission factors (EFs) of various pollutants from pellet burning. However, only a few field measurements have been conducted on the emissions of carbon monoxide (CO), particulate matter (PM), and polycyclic aromatic hydrocarbons (PAHs) from the combustion of pellets. In this study, pine wood and corn straw pellets were burned in a pellet burner (2.6 kW), and the EFs of CO, organic carbon, elemental carbon, PM, and PAHs (EF(CO), EF(OC), EF(EC), EF(PM), and EF(PAH)) were determined. The average EF(CO), EF(OC), EF(EC), and EF(PM) were 1520 ± 1170, 8.68 ± 11.4, 11.2 ± 8.7, and 188 ± 87 mg/MJ for corn straw pellets and 266 ± 137, 5.74 ± 7.17, 2.02 ± 1.57, and 71.0 ± 54.0 mg/MJ for pine wood pellets, respectively. Total carbonaceous carbon constituted 8 to 14% of the PM mass emitted. The measured values of EF(PAH) for the two pellets were 1.02 ± 0.64 and 0.506 ± 0.360 mg/MJ, respectively. The secondary side air supply in the pellet burner did not change the EFs of most pollutants significantly (p > 0.05). The only exceptions were EF(OC) and EF(PM) for pine wood pellets because of reduced combustion temperatures with the increased air supply. In comparison with EFs for the raw pine wood and corn straw, EF(CO), EF(OC), EF(EC), and EF(PM) for pellets were significantly lower than those for raw fuels (p < 0.05). However, the differences in EF(PAH) were not significant (p > 0.05). Based on the measured EFs and thermal efficiencies, it was estimated that 95, 98, 98, 88, and 71% reductions in the total emissions of CO, OC, EC, PM, and PAHs could be achieved by replacing the raw biomass fuels combusted in

  13. Reductions in Emissions of Carbonaceous Particulate Matter and Polycyclic Aromatic Hydrocarbons from Combustion of Biomass Pellets in Comparisonwith Raw Fuel Burning

    PubMed Central

    SHEN, Guofeng; TAO, Shu; WEI, Siye; ZHANG, Yanyan; WANG, Rong; WANG, Bin; LI, Wei; SHEN, Huizhong; HUANG, Ye; CHEN, Yuanchen; CHEN, Han; YANG, Yifeng; WANG, Wei; WEI, Wen; WANG, Xilong; LIU, Wenxing; WANG, Xuejun; SIMONICH, Staci L. Massey

    2012-01-01

    Biomass pellets are emerging as a cleaner alternative to traditional biomass fuels. The potential benefits of using biomass pellets include improving energy utilization efficiency and reducing emissions of air pollutants. To assess the environmental, climate, and health significance of replacing traditional fuels with biomass pellets, it is critical to measure the emission factors (EFs) of various pollutants from pellet burning. However, only a few field measurements have been conducted on the emissions of carbon monoxide (CO), particulate matter (PM), and polycyclic aromatic hydrocarbons (PAHs) from the combustion of pellets. In this study, pine wood and corn straw pellets were burned in a pellet burner (2.6 kW) and the EFs of CO, organic carbon, elemental carbon, PM, and PAHs (EFCO, EFOC, EFEC, EFPM, and EFPAH) were determined. The average EFCO, EFOC, EFEC, and EFPM were 1520±1170, 8.68±11.4, 11.2±8.7, and 188±87 mg/MJ for corn straw pellets, and 266±137, 5.74±7.17, 2.02±1.57, and 71.0±54.0 mg/MJ for pine wood pellets, respectively. Total carbonaceous carbon constituted 8 to 14% of the PM mass emitted. The measured values of EFPAH for the two pellets were 1.02±0.64 and 0.506±0.360 mg/MJ, respectively. The secondary side air supply in the pellet burner did not change the EFs of most pollutants significantly (p > 0.05). The only exceptions were EFOC and EFPM for pine wood pellets because of reduced combustion temperatures with the increased air supply. In comparison with EFs for the raw pine wood and corn straw, EFCO, EFOC, EFEC, and EFPM for pellets were significantly lower than those for raw fuels (p < 0.05). However, the differences in EFPAH were not significant (p > 0.05). Based on the measured EFs and thermal efficiencies, it was estimated that 95, 98, 98, 88, and 71% reductions in the total emissions of CO, OC, EC, PM, and PAHs could be achieved by replacing the raw biomass fuels combusted in traditional cooking stoves with pellets burned in modern

  14. Non-destructive studies of fuel pellets by neutron resonance absorption radiography and thermal neutron radiography

    NASA Astrophysics Data System (ADS)

    Tremsin, A. S.; Vogel, S. C.; Mocko, M.; Bourke, M. A. M.; Yuan, V.; Nelson, R. O.; Brown, D. W.; Feller, W. B.

    2013-09-01

    fuel assemblies with intentionally introduced defects was investigated. The maps of elemental composition of pellets containing urania and tungsten were obtained simultaneously by resonance absorption imaging with spatial resolution better than ˜200 μm, while the voids and cracks were revealed by the transmission images obtained with thermal and cold neutrons. Our proof-of-principle experiments demonstrate that simultaneous acquisition of resonance and Bragg edge spectra enables concurrent mapping of isotope distributions, imaging of cracks and voids as well as measurements of some crystallographic parameters of fuel assemblies and their cladding. A detailed study of energy-dependent neutron statistics achievable at FP5 with our present detection system is also presented for a wide range of neutron energies.

  15. Demonstration of fuel resistant to pellet-cladding interaction: Phase 2. Fourth semiannual report, July-December 1980. [BWR

    SciTech Connect

    Rosenbaum, H.S.

    1981-03-01

    This program has as its ultimate objective the demonstration of an advanced fuel design that is resistant to the failure mechanism known as fuel pellet-cladding interaction (PCI). Two fuel concepts have been developed for possible demonstration: (a) Cu-barrier fuel and (b) Zr-liner fuel. These advanced fuels (known collectively as barrier fuels) have special fuel cladding designed to avoid the harmful effects of localized stress and reactive fission products during reactor service. Within the scope of this program one of these concepts had to be selected for a large-scale demonstration in a commercial power reactor. The selection was made to demonstrate Zr-liner fuel and to include bundles which have liners prepared from either low oxygen sponge zirconium or of crystal bar zirconium. The demonstration is intended to include a total of 132 barrier bundles in the reload for Quad Cities Unit 2, Cycle 6. In the current report period changes in the nuclear design were made to respond to changes in the Energy Utilization Plan for Quad Cities Unit 2. Bundle designs were completed, and were licensed for use in a BWR/3. The core specific licensing will be done as part of the reload license for Quad Cities Unit 2, Cycle 6.

  16. Analysis of pellet cladding interaction and creep of U 3SIi2 fuel for use in light water reactors

    NASA Astrophysics Data System (ADS)

    Metzger, Kathryn E.

    Following the accident at the Fukushima plant, enhancing the accident tolerance of the light water reactor (LWR) fleet became a topic of serious discussion. Under the direction of congress, the DOE office of Nuclear Energy added accident tolerant fuel development as a primary component to the existing Advanced Fuels Program. The DOE defines accident tolerant fuels as fuels that "in comparison with the standard UO2- Zircaloy system currently used by the nuclear industry, can tolerate loss of active cooling in the reactor core for a considerably longer time period (depending on the LWR system and accident scenario) while maintaining or improving the fuel performance during normal operations, operational transients, as well as design-basis and beyond design-basis events." To be economically viable, proposed accident tolerant fuels and claddings should be backward compatible with LWR designs, provide significant operating cost improvements such as power uprates, increased fuel burnup, or increased cycle length. In terms of safety, an alternative fuel pellet must have resistance to water corrosion comparable to UO2, thermal conductivity equal to or larger than that of UO2, and a melting temperature that allows the material to remain solid under power reactor conditions. Among the candidates, U3Si2 has a number of advantageous thermophysical properties, including; high density, high thermal conductivity at room temperature, and a high melting temperature. These properties support its use as an accident tolerant fuel while its high uranium density is capable of supporting uprates to the LWR fleet. This research characterizes U3Si2 pellets and analyzes U3Si2 under light water reactor conditions using the fuel performance code BISON. While some thermophysical properties for U3Si2 have been found in the literature, the irradiation behavior is sparse and limited to experience with dispersion fuels. Accordingly, the creep behavior for U3Si2 has been unknown, making it

  17. Densification of uranium dioxide fuel pellets prepared by spark plasma sintering (SPS)

    NASA Astrophysics Data System (ADS)

    Ge, Lihao; Subhash, Ghatu; Baney, Ronald H.; Tulenko, James S.; McKenna, Edward

    2013-04-01

    An investigation into the influence of processing parameters on densification of UO2 powder during spark plasma sintering (SPS) is presented. A broad range of sintering temperatures, hold time and heating rates have been systematically varied to investigate their influence on the sintered pellet densification process, grain growth, hardness, and Young's modulus. The results revealed that up to 96% theoretical density (TD) pellets can be obtained at a sintering temperature of 1050 °C for 30 s hold time and a total run time of only 10 min. The resulting UO2 pellets had an average Vickers hardness of 6.4 ± 0.4 GPa and Young's modulus of 204 ± 18 GPa, which are in excellent agreement with values reported in literature for UO2 processed by other methods.

  18. Analysis of an arc-driven railgun for fusion fuel pellet injection

    SciTech Connect

    Azzerboni, B. ); Cardelli, E.; Raugi, M.; Tellini, A. )

    1990-11-01

    In this paper the behavior of an arc-driven railgun for hydrogen pellet injection is examined. Launch of saboted and unsaboted pellets is considered, and the arc mass influence on the behavior of the accelerating system is analyzed in both cases. The characteristic quantities of the hydrogen plasma armature are evaluated by means of an a dimensional model. The efficiency of the system is investigated as to whether or not the recovery of the energy remaining in the railgun at the time of launch is performed.

  19. Advances in the Use of Thermography to Inspect Composite Tanks for Liquid Fuel Propulsion Systems

    NASA Technical Reports Server (NTRS)

    Lansing, Matthew D.; Russell, Samuel S.; Walker, James L.; Jones, Clyde S. (Technical Monitor)

    2001-01-01

    This viewgraph presentation gives an overview of advances in the use of thermography to inspect composite tanks for liquid fuel propulsion systems. Details are given on the thermographic inspection system, thermographic analysis method (includes scan and defect map, method of inspection, and inclusions, ply wrinkle, and delamination defects), graphite composite cryogenic feedline (including method, image map, and deep/shallow inclusions and resin rich area defects), and material degradation nondestructive evaluation.

  20. Important properties of bamboo pellets to be used as commercial solid fuel in China

    Treesearch

    Zhijia Liu; Benhua Fei; Zehui Jiang; Zhiyong Cai; Xing' e Liu

    2014-01-01

    Bamboo is a type of biomass material and has great potential as a bioenergy resource of the future in China. Some properties of bamboo pellets, length, diameter, moisture content (MC), particle density, bulk density, durability, fine content, ash, gross calorific value, combustion rate and heat release rate, were determined and the effects of MC and particle size (PS)...

  1. Microwave based oxidation process for recycling the off-specification (U,Pu)O2 fuel pellets

    NASA Astrophysics Data System (ADS)

    Singh, G.; Khot, P. M.; Kumar, Pradeep; Bhatt, R. B.; Behere, P. G.; Afzal, Mohd

    2017-02-01

    This paper reports development of a process named MicroWave Direct Oxidation (MWDO) for recycling the off-specification (U,Pu)O2 mixed oxide (MOX) fuel pellets generated during fabrication of typical fast reactor fuels. MWDO is a two-stage, single-cycle process based on oxidative pulverisation of pellets using 2450 MHz microwave. The powder sinterability was evaluated by bulk density and BET specific surface area. The oxidised powders were analyzed for phases using XRD and stoichiometry by thermogravimetry. The sinterability was significantly enhanced by carrying out oxidation in higher oxygen partial pressure and by subjecting MOX to multiple micronisation-oxidation cycles. After three cycles, the recycled powder from (U,28%Pu)O2 resulted surface area >3 m2/g and 100% re-used for MOX fabrication. The flow sheet was developed for maximum utilization of recycled powder describable by a parameter called Scrap Recycling Ratio (SRR). The process demonstrates smaller processing cycle, better powder properties and higher oxidative pulverisation over conventional method.

  2. Effects of fuel particle size and fission-fragment-enhanced irradiation creep on the in-pile behavior in CERCER composite pellets

    NASA Astrophysics Data System (ADS)

    Zhao, Yunmei; Ding, Shurong; Zhang, Xunchao; Wang, Canglong; Yang, Lei

    2016-12-01

    The micro-scale finite element models for CERCER pellets with different-sized fuel particles are developed. With consideration of a grain-scale mechanistic irradiation swelling model in the fuel particles and the irradiation creep in the matrix, numerical simulations are performed to explore the effects of the particle size and the fission-fragment-enhanced irradiation creep on the thermo-mechanical behavior of CERCER pellets. The enhanced irradiation creep effect is applied in the 10 μm-thick fission fragment damage matrix layer surrounding the fuel particles. The obtained results indicate that (1) lower maximum temperature occurs in the cases with smaller-sized particles, and the effects of particle size on the mechanical behavior in pellets are intricate; (2) the first principal stress and radial axial stress remain compressive in the fission fragment damage layer at higher burnup, thus the mechanism of radial cracking found in the experiment can be better explained.

  3. 76 FR 67765 - Notice of Availability of Uranium Enrichment Fuel Cycle Facility's Inspection Reports Regarding...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-02

    ... COMMISSION Notice of Availability of Uranium Enrichment Fuel Cycle Facility's Inspection Reports Regarding... CONTACT: Gregory Chapman, Project Manager, Uranium Enrichment Branch, Division of Fuel Cycle Safety and... Energy Act of 1954, as amended. The introduction of uranium hexafluoride into any module of the...

  4. 77 FR 65729 - Uranium Enrichment Fuel Cycle Facility Inspection Reports Regarding Louisiana Energy Services LLC...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-30

    ... COMMISSION Uranium Enrichment Fuel Cycle Facility Inspection Reports Regarding Louisiana Energy Services LLC... Act of 1954, as amended. The introduction of uranium hexafluoride into any module of the National... Regulatory Commission Brian W. Smith, Chief, Uranium Enrichment Branch, Division of Fuel Cycle Safety...

  5. Detailed Reaction Kinetics for CFD Modeling of Nuclear Fuel Pellet Coating for High Temperature Gas-Cooled Reactors

    SciTech Connect

    Battaglia, Francine

    2008-11-29

    The research project was related to the Advanced Fuel Cycle Initiative and was in direct alignment with advancing knowledge in the area of Nuclear Fuel Development related to the use of TRISO fuels for high-temperature reactors. The importance of properly coating nuclear fuel pellets received a renewed interest for the safe production of nuclear power to help meet the energy requirements of the United States. High-temperature gas-cooled nuclear reactors use fuel in the form of coated uranium particles, and it is the coating process that was of importance to this project. The coating process requires four coating layers to retain radioactive fission products from escaping into the environment. The first layer consists of porous carbon and serves as a buffer layer to attenuate the fission and accommodate the fuel kernel swelling. The second (inner) layer is of pyrocarbon and provides protection from fission products and supports the third layer, which is silicon carbide. The final (outer) layer is also pyrocarbon and provides a bonding surface and protective barrier for the entire pellet. The coating procedures for the silicon carbide and the outer pyrocarbon layers require knowledge of the detailed kinetics of the reaction processes in the gas phase and at the surfaces where the particles interact with the reactor walls. The intent of this project was to acquire detailed information on the reaction kinetics for the chemical vapor deposition (CVD) of carbon and silicon carbine on uranium fuel pellets, including the location of transition state structures, evaluation of the associated activation energies, and the use of these activation energies in the prediction of reaction rate constants. After the detailed reaction kinetics were determined, the reactions were implemented and tested in a computational fluid dynamics model, MFIX. The intention was to find a reduced mechanism set to reduce the computational time for a simulation, while still providing accurate results

  6. Simulation with DIONISIO 1.0 of thermal and mechanical pellet-cladding interaction in nuclear fuel rods

    NASA Astrophysics Data System (ADS)

    Soba, Alejandro; Denis, Alicia

    2008-02-01

    The code DIONISIO 1.0 describes most of the main phenomena occurring in a fuel rod throughout its life under normal operation conditions of a nuclear thermal reactor. Starting from the power history, DIONISIO predicts the temperature distribution in the domain, elastic and plastic stress and strain, creep, swelling and densification, release of fission gases, caesium and iodine to the rod free volume, gas mixing, pressure increase, restructuring and grain growth in the UO 2 pellet, irradiation growth of the Zircaloy cladding, oxide layer growth on its surface, hydrogen uptake and the effects of a corrosive atmosphere either internal or external. In particular, the models of thermal conductance of the gap and of pellet-cladding mechanical interaction incorporated to the code constitute two realistic tools. The possibility of gap closure (including partial contact between rough surfaces) and reopening during burnup is allowed. The non-linear differential equations are integrated by the finite element method in two-dimensions assuming cylindrical symmetry. Good results are obtained for the simulation of several irradiation tests.

  7. Preparation of carbide-type, advanced LMFBR fuel pellets for irradiation testing

    SciTech Connect

    Gutierrez, R.L.; Herbst, R.J.

    1980-06-01

    A carbothermic reduction process was established to fabricate single- and two-phase uranium-plutonium carbide fuel on a production basis. Sintering temperatures of 1550 and 1800/sup 0/C were used to prepare fuel densities of 98, 87, and 81% of theoretical.

  8. Application of Digital Radiography to Weld Inspection for the Space Shuttle External Fuel Tank

    NASA Technical Reports Server (NTRS)

    Ussery, Warren

    2009-01-01

    This slide presentation reviews NASA's use of digital radiography to inspect the welds of the external tanks used to hold the cryogenic fuels for the Space Shuttle Main Engines. NASA has had a goal of replacing a significant portion of film used to inspect the welds, with digital radiography. The presentation reviews the objectives for converting to a digital system from film, the characteristics of the digital system, the Probability of detection study, the qualification and implementation of the system.

  9. Plutonium release from pressed plutonium oxide fuel pellets in aquatic environments

    SciTech Connect

    Patterson, J.H.; Steinkruger, F.J.; Matlack, G.M.; Heaton, R.C.; Coffelt, K.P.; Herrera, B.

    1983-12-01

    Plutonium oxide pellets (80% /sup 238/Pu, 40 g each) were exposed to fresh water and sea water at two temperatures for 3 y in enclosed glass chambers. The concentrations of plutonium observed in the waters increased linearly with time throughout the experiment. However, the observed release rates were inversely dependent on temperature and salinity, ranging from 160 ..mu..Ci/day for cold fresh water to 1.4 ..mu..Ci/day for warm sea water. The total releases, including the chamber residues, showed similar dependencies. A major portion (typically greater than 50%) of the released plutonium passed through a 0.1-..mu..m filter, with even larger fractions (greater than 80%) for the fresh water systems.

  10. The Experimental Determination of the Spectral Indices 28{rho} and 25{delta} inside of the Fuel Pellet of the IPEN/MB-01 Reactor

    SciTech Connect

    D'Utra Bitelli, Ulysses; Santos, Adimir dos; Siqueira, Paulo D.; Jerez, Rogerio; Fanaro, Leda C.C.B.; Cacuri, Rosangela R.

    2005-05-24

    This work presents the measurements of the spectral indices 28{rho} and 25{delta} inside of the fuel pellet. To reach this goal an appropriate gamma-counting system based on a cylindrical collimator to shield the gammas arising from the outermost ring is employed. The proposed system is shown to be adequate and in principle can be used to measure these spectral indices across the pellet radius. The theory comparison of the spectral indices shows that the currently released library ENDF/B-VI.8 agrees reasonably well with the measurements.

  11. INL Review of Fueling Machine Inspection Tool Development Proposal

    SciTech Connect

    Griffith, George

    2015-03-01

    A review of a technical proposal for James Fischer Nuclear. The document describes an inspection tool to examine the graphite moderator in an AGR reactor. The system is an optical system to look at the graphite blocks for cracks. INL reviews the document for technical value.

  12. ATR WG-MOX Fuel Pellet Burnup Measurement by Monte Carlo - Mass Spectrometric Method

    SciTech Connect

    Chang, Gray Sen I

    2002-10-01

    This paper presents a new method for calculating the burnup of nuclear reactor fuel, the MCWO-MS method, and describes its application to an experiment currently in progress to assess the suitability for use in light-water reactors of Mixed-OXide (MOX) fuel that contains plutonium derived from excess nuclear weapons material. To demonstrate that the available experience base with Reactor-Grade Mixed uranium-plutonium OXide (RGMOX) can be applied to Weapons-Grade (WG)-MOX in light water reactors, and to support potential licensing of MOX fuel made from weapons-grade plutonium and depleted uranium for use in United States reactors, an experiment containing WG-MOX fuel is being irradiated in the Advanced Test Reactor (ATR) at the Idaho National Engineering and Environmental Laboratory. Fuel burnup is an important parameter needed for fuel performance evaluation. For the irradiated MOX fuel’s Post-Irradiation Examination, the 148Nd method is used to measure the burnup. The fission product 148Nd is an ideal burnup indicator, when appropriate correction factors are applied. In the ATR test environment, the spectrum-dependent and burnup-dependent correction factors (see Section 5 for detailed discussion) can be substantial in high fuel burnup. The validated Monte Carlo depletion tool (MCWO) used in this study can provide a burnup-dependent correction factor for the reactor parameters, such as capture-to-fission ratios, isotopic concentrations and compositions, fission power, and spectrum in a straightforward fashion. Furthermore, the correlation curve generated by MCWO can be coupled with the 239Pu/Pu ratio measured by a Mass Spectrometer (in the new MCWO-MS method) to obtain a best-estimate MOX fuel burnup. A Monte Carlo - MCWO method can eliminate the generation of few-group cross sections. The MCWO depletion tool can analyze the detailed spatial and spectral self-shielding effects in UO2, WG-MOX, and reactor-grade mixed oxide (RG-MOX) fuel pins. The MCWO-MS tool only

  13. Simulation of the irradiation-induced micro-thermo-mechanical behaviors evolution in ADS nuclear fuel pellets

    NASA Astrophysics Data System (ADS)

    Ding, Shurong; Zhao, Yunmei; Wan, Jibo; Gong, Xin; Wang, Canglong; Yang, Lei; Huo, Yongzhong

    2013-11-01

    An Accelerator Driven System (ADS) is dedicated to Minor Actinides (MA) transmutation. The fuels for ADS are highly innovative, which are composite fuel pellets with the fuel particles containing MA phases dispersed in a MgO or Mo matrix. Assuming that the fuel particles are distributed periodically in the MgO matrix, a three-dimensional finite element model is developed. The three-dimensional incremental large-deformation constitutive relations for the fuel particles and matrix are separately built, and a method is accordingly constructed to implement simulation of the micro-thermo-mechanical behaviors evolution. Evolutions of the temperature and mechanical fields are given and discussed. With irradiation creep included in the MgO matrix constitutive relation, the conclusions can be drawn as that (1) irradiation creep has a remarkable effect on the mechanical behaviors evolution in the matrix; (2) irradiation creep plays an important role in the damage mechanism interpretation of ceramic matrix fuel pellets. Thermal conductivity The thermal conductivity model is adopted as KUO2 = K0·FD·FP·FM·FR, which was proposed by Lucuta et al. [10] to adapt to the high burnup conditions with consideration of the effects of temperature, burnup, porosity and fission products. K0 is the thermal conductivity of fully dense un-irradiated UO2, as Eq. (1) in W/m K; FD, FP are the adjust factors reflecting the effects of dissolved and precipitated fission products; FM and FR are factors due to porosity and irradiation effects. The adopted thermal conductivity varies with temperature and burnup, which expresses its degradation with burnup, with the terms as k0={1}/{0.0375+2.165×10-4T}+{4.715×109}/{T2}exp-{16361}/{T} FD={1.09}/{B3.265}+{0.0643}/{√{B}}√{T}artan{1}/{1.09/B3.265}+{0.0643}/{√{B}}√{T} FP=1+0.019B/3-0.019B{1}/{1+exp(1200-T100)} FM={1-P}/{1+(s-1)P} FR=1-{0.2}/{1+expT-90080} Thermal expansion The engineering strain of thermal expansion [11] is given as {ΔL}/{L0

  14. Laser-prearc railgun: Development for the application to a fuel pellet injector of a nuclear fusion reactor

    NASA Astrophysics Data System (ADS)

    Tamura, H.; Sawaoka, A. B.; Oda, Y.; Onozuka, M.; Kuribayashi, S.; Shimizu, K.

    1992-05-01

    The laser-prearc railgun, that utilizes the phenomenon of laser-induced arc formation, was constructed and tested with plastic pellet projectiles. We envision our railgun as especially well suited as a solid hydrogen pellet injector for magnetic confinement fusion. The system consisted of a gas gun for preacceleration of a pellet and a railgun for its primary acceleration. A Q-switched ruby laser was used to induce electrical breakdown of propellant helium gas behind a dielectric pellet in the railgun. The present railgun was shown to accelerate a plastic pellet up to a velocity of 2.4 km/s.

  15. Performance evaluation and post-irradiation examination of a novel LWR fuel composed of U0.17ZrH1.6 fuel pellets bonded to Zircaloy-2 cladding by lead bismuth eutectic

    NASA Astrophysics Data System (ADS)

    Balooch, Mehdi; Olander, Donald R.; Terrani, Kurt A.; Hosemann, Peter; Casella, Andrew M.; Senor, David J.; Buck, Edgar C.

    2017-04-01

    A novel light water reactor fuel has been designed and fabricated at the University of California, Berkeley; irradiated at the Massachusetts Institute of Technology Reactor; and examined within the Radiochemical Processing Laboratory at the Pacific Northwest National Laboratory. This fuel consists of U0.17ZrH1.6 fuel pellets core-drilled from TRIGA reactor fuel elements that are clad in Zircaloy-2 and bonded with lead-bismuth eutectic. The performance evaluation and post irradiation examination of this fuel are presented here.

  16. Grain growth and pore coarsening in dense nano-crystalline UO2+x fuel pellets

    DOE PAGES

    Yao, Tiankai; Mo, Kun; Yun, Di; ...

    2017-03-25

    Dense nano-sized UO2+x pellets are synthesized by spark plasma sintering with controlled stoichiometries (UO2.03 and UO2.11) and grain sizes (~100 nm), and subsequently isothermally annealed to study their effects on grain growth kinetics and microstructure stability. The grain growth kinetics is determined and analyzed focusing on the interaction between grain boundary migration, pore growth and coalescence. Grains grow much bigger in nano-sized UO2.11 than UO2.03 upon thermal annealing, consistent with the fact that hyper-stoichiometric UO2+x is beneficial for sintering due to enhanced U ion diffusion from excessive O ion interstitials. The activation energies of the grain growth for UO2.03 andmore » UO2.11 are determined as ~1.0 and 1.3~2.0 eV, respectively. As compared with the micron-sized UO2 in which volumetric diffusion dominates the grain coarsening with an activation energy of ~3.0 eV, the enhanced grain growth kinetics in nano-sized UO2+x suggests that grain boundary diffusion controls grain growth. Lastly, the higher activation energy of more hyper-stoichiometric nano-sized UO2.11 may be attributed to the excessive O interstitials pinning grain boundary migration.« less

  17. Looking Northeast Along Hallway between Pellet Plant and Oxide Building, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Looking Northeast Along Hallway between Pellet Plant and Oxide Building, including Virgin Hopper Bins - Hematite Fuel Fabrication Facility, Pellet Plant, 3300 State Road P, Festus, Jefferson County, MO

  18. Modeling of selected ceramic processing parameters employed in the fabrication of 238PuO2 fuel pellets

    SciTech Connect

    Brockman, R. A.; Kramer, D. P.; Barklay, C. D.; Cairns-Gallimore, D.; Brown, J. L.; Huling, J. C.; Van Pelt, C. E.

    2011-10-01

    Recent deep space missions utilize the thermal output of the radioisotope plutonium-238 as the fuel in the thermal to electrical power system. Since the application of plutonium in its elemental state has several disadvantages, the fuel employed in these deep space power systems is typically in the oxide form such as plutonium-238 dioxide (238PuO2). As an oxide, the processing of the plutonium dioxide into fuel pellets is performed via ''classical'' ceramic processing unit operations such as sieving of the powder, pressing, sintering, etc. Modeling of these unit operations can be beneficial in the understanding and control of processing parameters with the goal of further enhancing the desired characteristics of the 238PuO2 fuel pellets. A finite element model has been used to help identify the time-temperature-stress profile within a pellet during a furnace operation taking into account that 238PuO2 itself has a significant thermal output. The results of the modeling efforts will be discussed.

  19. 77 FR 18272 - Uranium Enrichment Fuel Cycle Facility Inspection Reports Regarding Louisiana Energy Services LLC...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-27

    ... well as autoclave one of the facility have been constructed in accordance with the requirements of the... number 1.5, 1.6, 1.7, 1.8, 2.1, and 2.4 as well as autoclave one of the facility have been constructed in... COMMISSION Uranium Enrichment Fuel Cycle Facility Inspection Reports Regarding Louisiana Energy Services LLC...

  20. Portable instrument for inspecting irradiated nuclear fuel assemblies

    DOEpatents

    Nicholson, Nicholas; Dowdy, Edward J.; Holt, David M.; Stump, Jr., Charles J.

    1985-01-01

    A portable instrument for measuring induced Cerenkov radiation associated with irradiated nuclear fuel assemblies in a water-filled storage pond is disclosed. The instrument includes a photomultiplier tube and an image intensifier which are operable in parallel and simultaneously by means of a field lens assembly and an associated beam splitter. The image intensifier permits an operator to aim and focus the apparatus on a submerged fuel assembly. Once the instrument is aimed and focused, an illumination reading can be obtained with the photomultiplier tube. The instrument includes a lens cap with a carbon-14/phosphor light source for calibrating the apparatus in the field.

  1. Magnetically suspended pellet for laser fusion scheme as a basis of fueling

    NASA Astrophysics Data System (ADS)

    Shimamura, Aki; Sato, Akihisa; Yoshida, Hiroki; Sakagami, Yukio

    2000-01-01

    In our laboratory, Magnetically Suspended Pellet (MSP), which is a Ni-coated Glass Micro Balloon (Ni-GMB) suspended in non-contact fashion in a vacuum chamber, has been studied. Three items are described in this paper. The first section presents the development of Magnetically Suspension System (MSS). The second is given about the method of horizontal damping of MSP using optical forces or electrical force. Optical forces are assumed to be the radiometric force and the photon force. The photon force is larger than the radiometric one at pressure below 28mPa. We want to develop another method using electric force. We can ascertain that the MSP is charged and moved in the electric field.In the third section, we propose novel methods to measure the specific susceptibility of a Ni-GMB and the thickness of a Ni thin film. The specific susceptibility of Ni-GMB Km is measured by observing the trajectory of Ni- GMB immersed in an oil bath. It is found that the Km is 9.75 at room temperature. The other method has been developed for the measurement of thickness of a Ni thin film. The method is that a base plane is made on the Ni thin film by pulsed laser ablation first, and next the thickness is measured referred to this base plane by multiple beam interferometry. Our proposed method can effectively give the thickness corresponding to that obtained from the quartz crystal monitor within measurement error with the inferred uniformity less than 5 percent.

  2. Prevention and cure of diseased fuel rod simulators, from conception to death, by timely and proper inspection. [PWR

    SciTech Connect

    Snyder, S.D.

    1980-01-01

    The major inspection methods - electrical, radiographic, and infrared - employed during the development, fabrication, and use of fuel rod simulators are described. Principal emphasis is placed on the infrared scanning inspection system and interpretation of test results. The role of liquid penetrant inspection and helium mass spectrograph testing is mentioned. Correlation and feed-back of information from all inspections during the development and fabrication steps are detailed.

  3. Thermal Properties of Lignocellulose Pellets

    NASA Astrophysics Data System (ADS)

    Wachter, Igor; Hirle, Siegfried; Balog, Karol

    2017-06-01

    This article deals with the characterization of biomass pellets using Differential Scanning Calorimetry. We used three types of industrially produced and commercially available pellets as samples: wood pellets containing grass, wood pellet containing bark and wood pellets without bark. Each of the samples were examined using the DSC method. Based on the measurements in atmosphere of air and nitrogen temperature, the changes caused by thermal degradation of various kinds of test fuels were observed. Subsequently, limits of exothermic processes, reaction enthalpy changes and the temperature at which exothermic reactions reached peaks were determined.

  4. Looking West at Line Two Pelletizing Line, Centering Furnaces and ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Looking West at Line Two Pelletizing Line, Centering Furnaces and Dewaxers of First Floor of Pellet Plant - Hematite Fuel Fabrication Facility, Pellet Plant, 3300 State Road P, Festus, Jefferson County, MO

  5. Intermediate pyrolysis of biomass energy pellets for producing sustainable liquid, gaseous and solid fuels.

    PubMed

    Yang, Y; Brammer, J G; Mahmood, A S N; Hornung, A

    2014-10-01

    This work describes the use of intermediate pyrolysis system to produce liquid, gaseous and solid fuels from pelletised wood and barley straw feedstock. Experiments were conducted in a pilot-scale system and all products were collected and analysed. The liquid products were separated into an aqueous phase and an organic phase (pyrolysis oil) under gravity. The oil yields were 34.1 wt.% and 12.0 wt.% for wood and barley straw, respectively. Analysis found that both oils were rich in heterocyclic and phenolic compounds and have heating values over 24 MJ/kg. The yields of char for both feedstocks were found to be about 30 wt.%, with heating values similar to that of typical sub-bituminous class coal. Gas yields were calculated to be approximately 20 wt.%. Studies showed that both gases had heating values similar to that of downdraft gasification producer gas. Analysis on product energy yields indicated the process efficiency was about 75%.

  6. AC-3-irradiation test of sphere-pac and pellet (U,Pu)C fuel in the US Fast Flux Test Facility

    NASA Astrophysics Data System (ADS)

    Bart, G.; Botta, F. B.; Hoth, C. W.; Ledergerber, G.; Mason, R. E.; Stratton, R. W.

    2008-05-01

    The objective of the AC-3 bundle experiment in the Fast Flux Test Facility (FFTF) was to evaluate a fuel fabrication method by 'direct conversion' of nitrate solutions into spherical uranium-plutonium carbide particles and to compare the irradiation performance of 'sphere-pac' fuel pins prepared at Paul Scherrer Institute (PSI) with standard pellet fuel pins fabricated at Los Alamos National Laboratory (LANL). The irradiation and post test examination results show that mixed carbide pellet fuel produced by powder methods and sphere-pac particle fuel developed by internal gelation techniques are both valuable advanced fuel candidates for liquid metal reactors. The PSI fabrication process with direct conversion of actinide nitrate solutions into various sizes of fuel spheres by internal gelation and direct filling of spheres into cladding tubes is seen as more easily transferable to remote operation, showing a significant reduction of process steps. The process is also adaptable for the fabrication of carbonitrides and nitrides (still based on a uranium matrix), as well as for actinides diluted in a (uranium-free) yttrium stabilized zirconium oxide matrix. The AC-3 fuel bundle was irradiated in the Fast Flux Test Facility (FFTF) during the years 1986-1988 for 630 full power days to a peak burn up of ˜8 at.% fissile material. All of the pins, irradiated at linear powers of up to 84 kW/m, with cladding outer temperatures of 465 °C appeared to be in good condition when removed from the assembly. The rebirth of interest for fast reactor systems motivated the earlier teams to report about the excellent, still perfectly relevant results reached; this paper focusing on the sphere-pac fuel behaviour.

  7. Premium Fuel Production From Mining and Timber Waste Using Advanced Separation and Pelletizing Technologies

    SciTech Connect

    Honaker, R. Q.; Taulbee, D.; Parekh, B. K.; Tao, D.

    2005-12-05

    The Commonwealth of Kentucky is one of the leading states in the production of both coal and timber. As a result of mining and processing coal, an estimated 3 million tons of fine coal are disposed annually to waste-slurry impoundments with an additional 500 million tons stored at a number of disposal sites around the state due to past practices. Likewise, the Kentucky timber industry discards nearly 35,000 tons of sawdust on the production site due to unfavorable economics of transporting the material to industrial boilers for use as a fuel. With an average heating value of 6,700 Btu/lb, the monetary value of the energy disposed in the form of sawdust is approximately $490,000 annually. Since the two industries are typically in close proximity, one promising avenue is to selectively recover and dewater the fine-coal particles and then briquette them with sawdust to produce a high-value fuel. The benefits are i) a premium fuel product that is low in moisture and can be handled, transported, and utilized in existing infrastructure, thereby avoiding significant additional capital investment and ii) a reduction in the amount of fine-waste material produced by the two industries that must now be disposed at a significant financial and environmental price. As such, the goal of this project was to evaluate the feasibility of producing a premium fuel with a heating value greater than 10,000 Btu/lb from waste materials generated by the coal and timber industries. Laboratory and pilot-scale testing of the briquetting process indicated that the goal was successfully achieved. Low-ash briquettes containing 5% to 10% sawdust were produced with energy values that were well in excess of 12,000 Btu/lb. A major economic hurdle associated with commercially briquetting coal is binder cost. Approximately fifty binder formulations, both with and without lime, were subjected to an extensive laboratory evaluation to assess their relative technical and economical effectiveness as binding

  8. Complementary effects of torrefaction and co-pelletization: Energy consumption and characteristics of pellets.

    PubMed

    Cao, Liang; Yuan, Xingzhong; Li, Hui; Li, Changzhu; Xiao, Zhihua; Jiang, Longbo; Huang, Binbin; Xiao, Zhihong; Chen, Xiaohong; Wang, Hou; Zeng, Guangming

    2015-06-01

    In this study, complementary of torrefaction and co-pelletization for biomass pellets production was investigated. Two kinds of biomass materials were torrefied and mixed with oil cake for co-pelletization. The energy consumption during pelletization and pellet characteristics including moisture absorption, pellet density, pellet strength and combustion characteristic, were evaluated. It was shown that torrefaction improved the characteristics of pellets with high heating values, low moisture absorption and well combustion characteristic. Furthermore, co-pelletization between torrefied biomass and cater bean cake can reduce several negative effects of torrefaction such as high energy consumption, low pellet density and strength. The optimal conditions for energy consumption and pellet strength were torrefied at 270°C and a blending with 15% castor bean cake for both biomass materials. The present study indicated that compelmentary performances of the torrefaction and co-pelletization with castor bean cake provide a promising alternative for fuel production from biomass and oil cake.

  9. Effect of Al(OH)3 on the sintering of UO2-Gd2O3 fuel pellets with addition of U3O8 from recycle

    NASA Astrophysics Data System (ADS)

    dos Santos, Lauro Roberto; Durazzo, Michelangelo; Urano de Carvalho, Elita Fontenele; Riella, Humberto Gracher

    2017-09-01

    The incorporation of gadolinium as burnable poison directly into nuclear fuel is important for reactivity compensation, which enables longer fuel cycles. The function of the burnable poison fuel is to control the neutron population in the reactor core during its startup and the beginning of the fuel burning cycle to extend the use of the fuel. The implementation of UO2-Gd2O3 poisoned fuel in Brazil has been proposed according to the future requirements established for the Angra-2 nuclear power plant. The UO2 powder used is produced from the Ammonium Uranyl Carbonate (AUC). The incorporation of Gd2O3 powder directly into the AUC-derived UO2 powder by dry mechanical blending is the most attractive process, because of its simplicity. Nevertheless, processing by this method leads to difficulties while obtaining sintered pellets with the minimum required density. The cause of the low densities is the bad sintering behavior of the UO2-Gd2O3 mixed fuel, which shows a blockage in the sintering process that hinders the densification. This effect has been overcome by microdoping of the fuel with small quantities of aluminum. The process for manufacturing the fuel inevitably generates uranium-rich scraps from various sources. This residue is reincorporated into the production process in the form of U3O8 powder additions. The addition of U3O8 also hinders densification in sintering. This study was carried out to investigate the influence of both aluminum and U3O8 additives on the density of fuel pellets after sintering. As the effects of these additives are counterposed, this work studied the combined effect thereof, seeking to find an applicable composition for the production process. The experimental results demonstrated the effectiveness of aluminum, in the form of Al(OH)3, as an additive to promote increase in the densification of the (U,Gd)O2 pellets during sintering, even with high additions of U3O8 recycled from the manufacturing process.

  10. Experimental Studies on the Self-Shielding Effect in Fissile Fuel Breeding Measurement in Thorium Oxide Pellets Irradiated with 14 MeV Neutrons

    NASA Astrophysics Data System (ADS)

    Mitul, Abhangi; Nupur, Jain; Rajnikant, Makwana; Sudhirsinh, Vala; Shrichand, Jakhar; K. Basu, T.; V. S. Rao, C.

    2013-02-01

    The 14 MeV neutrons produced in the D-T fusion reactions have the potential of breeding Uranium-233 fissile fuel from fertile material Thorium-232. In order to estimate the amount of U-233 produced, experiments are carried out by irradiating thorium dioxide pellets with neutrons produced from a 14 MeV neutron generator. The objective of the present work is to measure the reaction rates of 232Th + 1n → 233Th → 233Pa → 233U in different pellet thicknesses to study the self-shielding effects and adopt a procedure for correction. An appropriate assembly consisting of high-density polyethylene is designed and fabricated to slow down the high-energy neutrons, in which Thorium pellets are irradiated. The amount of fissile fuel (233U) produced is estimated by measuring the 312 keV gammas emitted by Protactinium-233 (half-life of 27 days). A calibrated High Purity Germanium (HPGe) detector is used to measure the gamma ray spectrum. The amount of 233U produced by Th232 (n, γ) is calculated using MCNP code. The self-shielding effect is evaluated by calculating the reaction rates for different foil thickness. MCNP calculation results are compared with the experimental values and appropriate correction factors are estimated for self-shielding of neutrons and absorption of gamma rays.

  11. How the user can influence particulate emissions from residential wood and pellet stoves: Emission factors for different fuels and burning conditions

    NASA Astrophysics Data System (ADS)

    Fachinger, Friederike; Drewnick, Frank; Gieré, Reto; Borrmann, Stephan

    2017-06-01

    For a common household wood stove and a pellet stove we investigated the dependence of emission factors for various gaseous and particulate pollutants on burning phase, burning condition, and fuel. Ideal and non-ideal burning conditions (dried wood, under- and overload, small logs, logs with bark, excess air) were used. We tested 11 hardwood species (apple, ash, bangkirai, birch, beech, cherry, hickory, oak, olive, plum, sugar maple), 4 softwood species (Douglas fir, pine, spruce, spruce/fir), treated softwood, beech and oak wood briquettes, paper briquettes, brown coal, wood chips, and herbaceous species (miscanthus, Chinese silver grass) as fuel. Particle composition (black carbon, non-refractory, and some semi-refractory species) was measured continuously. Repeatability was shown to be better for the pellet stove than for the wood stove. It was shown that the user has a strong influence on wood stove emission behavior both by selection of the fuel and of the burning conditions: Combustion efficiency was found to be low at both very low and very high burn rates, and influenced particle properties such as particle number, mass, and organic content in a complex way. No marked differences were found for the emissions from different wood species. For non-woody fuels, much higher emission factors could be observed (up to five-fold increase). Strongest enhancement of emission factors was found for burning of small or dried logs (up to six-fold), and usage of excess air (two- to three-fold). Real world pellet stove emissions can be expected to be much closer to laboratory-derived emission factors than wood stove emissions, due to lower dependence on user operation.

  12. Pelletizing properties of torrefied spruce

    Treesearch

    Wolfgang Stelte; Craig Clemons; Jens K. Holm; Anand R. Sanadi; Jesper Ahrenfeldt; Lei Shang; Ulrik B. Henriksen

    2011-01-01

    Torrefaction is a thermo-chemical conversion process improving the handling, storage and combustion properties of wood. To save storage space and transportation costs, it can be compressed into fuel pellets of high physical and energetic density. The resulting pellets are relatively resistant to moisture uptake, microbiological decay and easy to comminute into small...

  13. An evaluation of UO2-CNT composites made by SPS as an accident tolerant nuclear fuel pellet and the feasibility of SPS as an economical fabrication process for the nuclear fuel cycle

    NASA Astrophysics Data System (ADS)

    Cartas, Andrew R.

    The innovative and advanced purpose of this study is to understand and establish proper sintering procedures for Spark Plasma Sintering process in order to fabricate high density, high thermal conductivity UO2 -CNT pellets. Mixing quality and chemical reactions have been investigated by field emission scanning electron microscopy (FESEM), wavelength dispersive spectroscopy (WDS), and X-ray diffraction (XRD). The effect of various types of CNTs on the mixing and sintering quality of UO2-CNT pellets with SPS processing have been examined. The Archimedes Immersion Method, laser flash method, and FE-SEM will be used to investigate the density, thermal conductivity, grain size, pinning effects, and CNT dispersion of fabricated UO2-CNT pellets. Pre-fabricated CNT's were added to UO 2 powder and dispersed via sonication and/or ball milling and then made into composite nuclear pellets. An investigation of the economic impact of SPS on the nuclear fuel cycle for producing pure and composite UO2 fuels was conducted.

  14. Engineering Work Plan for Development of Sludge Pickup Adapter for Fuel Cleanliness Inspections

    SciTech Connect

    PITNER, A.L.

    2000-01-06

    The plan for developing an adapter to suction up sludge into a calibrated tube for fuel cleanliness inspection activities is described. A primary assessment of fuel cleanliness to be performed after processing through the Primary Cleaning Machine is whether the volume of any remaining canister sludge in or on a fuel assembly exceeds the allowable 14 cm{sup 3} limit. It is anticipated that a general visual inspection of the sludge inventory after fuel assembly separation will usually suffice in making this assessment, but occasions may arise where there is some question as to whether or not the observed quantity of sludge exceeds this limit. Therefore a quantitative method of collecting and measuring the sludge volume is needed for these borderline situations. It is proposed to develop an adapter that fits on the end of the secondary cleaning station vacuum wand that will suction the material from the sludge collection tray into a chamber marked with the limiting volume to permit a direct go/no-go assessment of the sludge quantity.

  15. Owl Pellets.

    ERIC Educational Resources Information Center

    Thompson, Craig D.

    1987-01-01

    Provides complete Project WILD lesson plans for 20-45-minute experiential science learning activity for grades 3-7 students. Describes how students construct a simple food chain through examination of owl pellets. Includes lesson objective, method, background information, materials, procedure, evaluation, and sources of owl pellets and posters.…

  16. Owl Pellets.

    ERIC Educational Resources Information Center

    Thompson, Craig D.

    1987-01-01

    Provides complete Project WILD lesson plans for 20-45-minute experiential science learning activity for grades 3-7 students. Describes how students construct a simple food chain through examination of owl pellets. Includes lesson objective, method, background information, materials, procedure, evaluation, and sources of owl pellets and posters.…

  17. Method for reporting in-use vehicle fuel consumption and carbon dioxide emissions from a fast-pass transient inspection.

    PubMed

    Stewart, Steve

    2004-05-01

    A method has been developed that allows reporting of the fuel consumption and carbon dioxide (CO2) emissions for in-use vehicles from a fast-pass transient (IM240) inspection. The major technical obstacle to reporting CO2 emission rate and fuel consumption is that inspection and maintenance tests do not all use a standardized test duration or test method. The method is able to project full-duration fuel consumption from IM240 tests that actually fast-passed as early as just 30 sec from starting the test. It is based on basic considerations of the work done in driving the inspection cycle, with additional empirical adjustments. The initial application examined the differences between passing and failing inspections, and this did confirm that there are significant differences.

  18. Pelletizing lignite

    DOEpatents

    Goksel, Mehmet A.

    1983-11-01

    Lignite is formed into high strength pellets having a calorific value of at least 9,500 Btu/lb by blending a sufficient amount of an aqueous base bituminous emulsion with finely-divided raw lignite containing its inherent moisture to form a moistened green mixture containing at least 3 weight % of the bituminous material, based on the total dry weight of the solids, pelletizing the green mixture into discrete green pellets of a predetermined average diameter and drying the green pellets to a predetermined moisture content, preferrably no less than about 5 weight %. Lignite char and mixture of raw lignite and lignite char can be formed into high strength pellets in the same general manner.

  19. Oxidation of UO 2 fuel pellets in air at 503 and 543 K studied using X-ray photoelectron spectroscopy and X-ray diffraction

    NASA Astrophysics Data System (ADS)

    Tempest, P. A.; Tucker, P. M.; Tyler, J. W.

    1988-02-01

    An understanding of the low temperature oxidation behaviour of UO 2 pellets in air is important in the unlikely event of gas ingress to a fuel can during handling or storage. The main parameter of concern is the production time of U 3O 8 particulate as a function of temperature. Factors which affect the UO2 → U3O8 transformation have been investigated by sequentially oxidising UO 2 fuel pellets in air at 503 and 543 K and monitoring the growth of U 3O and U 3O 7 using X-ray photoelectron spectroscopy, X-ray diffraction and scanning electron microscopy. Initially oxidation proceeded at a linear rate by the inward diffusion of oxygen to form a complete layer of substoichiometric U 3O 7. This phase was tetragonal with a {c}/{a} ratio of 1.015, significantly less than the value of 1.03 measured on UO 2 powder when oxidised under identical conditions. This difference and the preferred orientation exhibited by surface grains were caused by growth stresses induced in the pellet surface. Both intergranular and transgranular cracking occurred and became nucleation sites for the growth of U 3O 8. The linear oxidation period associated with U 3O 7 growth was much shorter at 543 than at 503 K and U 3O 8 nucleated earlier. Spallation and the production of particulate were only observed during the formation of U 3O 8 when a 30% increase in volume arose from the U3O7 → U3O8 phase change.

  20. Pellet injection into ATF plasmas

    SciTech Connect

    Wilgen, J.B.; Bell, J.D.; England, A.C.; Fisher, P.W.; Howe, H.C.; Murakami, M.; Rasmussen, D.A.; Richards, R.K.; Uckan, T.; Wing, W.R. ); Bell, G.L. ); Qualls, A.L. ); Sudo, S. )

    1990-01-01

    Based on the favorable empirical scaling of stellarator confinement with increasing electron density, pellet fueling is expected to result in significant performance improvement of the ATF plasma. With gas-puff fueling, NBI heated plasmas in ATF are limited by a thermal collapse. Pellet fueling provides a potential means to delay this effect and gain access to the favorable high density confinement regime. To provide flexibility for optimization and physics studies, eight different pellet sizes are available. To date, line average densities of up to 4 {times} 10{sup 13} cm{sup {minus}3} have been achieved with a single pellet injected into a 0.7 MW NBI plasma at 0.95 T; the results from optimization studies with up to 1.5 MW of NBI power at 2 T will be presented.

  1. Production of zinc pellets

    SciTech Connect

    Cooper, J.F.

    1996-11-26

    Uniform zinc pellets are formed for use in batteries having a stationary or moving slurry zinc particle electrode. The process involves the cathodic deposition of zinc in a finely divided morphology from battery reaction product onto a non-adhering electrode substrate. The mossy zinc is removed from the electrode substrate by the action of gravity, entrainment in a flowing electrolyte, or by mechanical action. The finely divided zinc particles are collected and pressed into pellets by a mechanical device such as an extruder, a roller and chopper, or a punch and die. The pure zinc pellets are returned to the zinc battery in a pumped slurry and have uniform size, density and reactivity. Applications include zinc-air fuel batteries, zinc-ferricyanide storage batteries, and zinc-nickel-oxide secondary batteries. 6 figs.

  2. Production of zinc pellets

    DOEpatents

    Cooper, John F.

    1996-01-01

    Uniform zinc pellets are formed for use in batteries having a stationary or moving slurry zinc particle electrode. The process involves the cathodic deposition of zinc in a finely divided morphology from battery reaction product onto a non-adhering electrode substrate. The mossy zinc is removed from the electrode substrate by the action of gravity, entrainment in a flowing electrolyte, or by mechanical action. The finely divided zinc particles are collected and pressed into pellets by a mechanical device such as an extruder, a roller and chopper, or a punch and die. The pure zinc pellets are returned to the zinc battery in a pumped slurry and have uniform size, density and reactivity. Applications include zinc-air fuel batteries, zinc-ferricyanide storage batteries, and zinc-nickel-oxide secondary batteries.

  3. Production of zinc pellets

    DOEpatents

    Cooper, J.F.

    1996-11-26

    Uniform zinc pellets are formed for use in batteries having a stationary or moving slurry zinc particle electrode. The process involves the cathodic deposition of zinc in a finely divided morphology from battery reaction product onto a non-adhering electrode substrate. The mossy zinc is removed from the electrode substrate by the action of gravity, entrainment in a flowing electrolyte, or by mechanical action. The finely divided zinc particles are collected and pressed into pellets by a mechanical device such as an extruder, a roller and chopper, or a punch and die. The pure zinc pellets are returned to the zinc battery in a pumped slurry and have uniform size, density and reactivity. Applications include zinc-air fuel batteries, zinc-ferricyanide storage batteries, and zinc-nickel-oxide secondary batteries. 6 figs.

  4. Pellet Puzzlers.

    ERIC Educational Resources Information Center

    Hoots, R. A.

    1992-01-01

    Presents information on owl's taxonomy, characteristics, and influences on man. Describes owl pellets, which are digestive discards, and explains how they can be used to determine the owl's diet as a science activity. (PR)

  5. Pellet Puzzlers.

    ERIC Educational Resources Information Center

    Hoots, R. A.

    1992-01-01

    Presents information on owl's taxonomy, characteristics, and influences on man. Describes owl pellets, which are digestive discards, and explains how they can be used to determine the owl's diet as a science activity. (PR)

  6. Development of an Innovative High-Thermal Conductivity UO2 Ceramic Composites Fuel Pellets with Carbon Nano-Tubes Using Spark Plasma Sintering

    SciTech Connect

    Subhash, Ghatu; Wu, Kuang-Hsi; Tulenko, James

    2014-03-10

    Uranium dioxide (UO2) is the most common fuel material in commercial nuclear power reactors. Despite its numerous advantages such as high melting point, good high-temperature stability, good chemical compatibility with cladding and coolant, and resistance to radiation, it suffers from low thermal conductivity that can result in large temperature gradients within the UO2 fuel pellet, causing it to crack and release fission gases. Thermal swelling of the pellets also limits the lifetime of UO2 fuel in the reactor. To mitigate these problems, we propose to develop novel UO2 fuel with uniformly distributed carbon nanotubes (CNTs) that can provide high-conductivity thermal pathways and can eliminate fuel cracking and fission gas release due to high temperatures. CNTs have been investigated extensively for the past decade to explore their unique physical properties and many potential applications. CNTs have high thermal conductivity (6600 W/mK for an individual single- walled CNT and >3000 W/mK for an individual multi-walled CNT) and high temperature stability up to 2800°C in vacuum and about 750°C in air. These properties make them attractive candidates in preparing nano-composites with new functional properties. The objective of the proposed research is to develop high thermal conductivity of UO2–CNT composites without affecting the neutronic property of UO2 significantly. The concept of this goal is to utilize a rapid sintering method (5–15 min) called spark plasma sintering (SPS) in which a mixture of CNTs and UO2 powder are used to make composites with different volume fractions of CNTs. Incorporation of these nanoscale materials plays a fundamentally critical role in controlling the performance and stability of UO2 fuel. We will use a novel in situ growth process to grow CNTs on UO2 particles for rapid sintering and develop UO2-CNT composites. This method is expected to provide a uniform distribution of CNTs at various volume fractions so that a high

  7. Design and Development of a Robotic Crawler for CANDU Fuel Channel Inspection

    NASA Astrophysics Data System (ADS)

    Shukla, Shivam

    For the design of a new robotic crawler drive unit for CANDU fuel channel inspection, a complete design and screening process was done in order to fulfil the objective of this research. A brief explanation of CANDU reactors is provided along with a discussion of the inspection systems that are currently in use. A study of some existing inspection systems is presented which was used for the development of the new robotic crawler design. A number of concepts were generated which underwent a screening process with the help of two design tools. With the help of these tools, a concept was chosen as the final design and details of it are presented. To demonstrate a proof-of-concept, the physical prototype of the robotic crawler was manufactured and assembled. A speed controller was implemented in the final design of the robotic crawler. A set of test procedures were performed on the final design and the results are discussed. Some improvements that can be done on the final design of the robotic crawler are also discussed in the final section of this thesis.

  8. Comparative Properties of Bamboo and Rice Straw Pellets

    Treesearch

    Xianmiao Liu; Zhijia Liu; Benhua Fei; Zhiyong Cai; Zehui Jiang; Xing' e Liu

    2013-01-01

    Bamboo is a potential major bio-energy resource. Tests were carried out to compare and evaluate the property of bamboo and rice straw pellets, rice straw being the other main source of biomass solid fuel in China. All physical properties of untreated bamboo pellets (UBP), untreated rice straw pellets (URP), carbonized bamboo pellets (CBP), and carbonized rice straw...

  9. Demonstration of fuel resistant to pellet-cladding interaction: Phase 2. Third semiannual report, January-June 1980

    SciTech Connect

    Rosenbaum, H.S.

    1980-09-01

    Two fuel concepts are being developed for possible demonstration within this program: (a) Cu-barrier fuel and (b) Zr-liner fuel. These advanced fuels (known collectively as barrier fuels) have special fuel cladding designed to avoid the harmful effects of localized stress and reactive fission products during reactor service. Within the work scope of this program one of these concepts is to be selected for demonstration in a commercial power reactor. It was decided to demonstrate Zr-liner in 132 bundles which have liners of either crystal-bar zirconium or of low-oxygen sponge zirconium in the reload for Quad Cities Unit 2, Cycle 6. Irradiation testing or barrier fuel was continued, and the superior PCI resistance of Zr-liner fuel was further substantiated in the current report period. Furthermore, an irradiation experiment in which Zr-liner fuel, having a deliberately fabricated cladding perforation, was operated at a linear heat generation rate of 35 kW/m to a burnup of approx. 3 MWd/kg U showed no unusual signs of degradation compared with a similarly defected reference fuel rod. Four lead test assemblies of barrier fuel (two of Zr-liner and two of Cu-barrier), presently under irradiation in Quad Cities Unit 1, have achieved a burnup of 11 MWd/kg U.

  10. Pellet injector research at ORNL

    SciTech Connect

    Schuresko, D.D.; Milora, S.L.; Combs, S.K.; Foster, C.A.; Fisher, P.W.; Argo, B.E.; Barber, G.C.; Foust, C.R.; Gethers, F.E.; Gouge, M.J.

    1987-01-01

    Several advanced plasma fueling systems are under development at the Oak Ridge National Laboratory (ORNL) for present and future magnetic confinement devices. These include multishot and repeating pneumatic pellet injectors, centrifuge accelerators, electrothermal guns, a Tritium Proof-of-Principle experiment, and an ultrahigh velocity mass ablation driven accelerator. A new eight-shot pneumatic injector capable of delivering 3.0 mm, 3.5 mm, and 4.0 mm diameter pellets at speeds up to 1500 m/s into a single discharge has been commissioned recently on the Tokamak Fusion Test reactor. The so-called Deuterium Pellet Injector (DPI) is a prototype of a Tritium Pellet Injector (TPI) scheduled for use on TFTR in 1990. Construction of the TPI will be preceded by a test of tritium pellet fabrication and acceleration using a 4 mm bore ''pipe gun'' apparatus. A new repeating pneumatic pellet injector capable of 2.7 mm, 4 mm, and 6 mm operation is being installed on the Joint European Torus to be used in ORNL/JET collaborative pellet injection studies. A 1.5 m centrifuge injector is being developed for application on the Tore Supra experiment in 1988. The new device, which is a 50% upgrade of the prototype centrifuge used on D-III, features a pellet feed mechanism capable of producing variable-size pellets (1.5 to 3.0 mm diameter) optimally shaped to survive acceleration stresses. Accelerating pellets to velocities in excess of 2 km/s is being pursued through two new development undertakings. A hydrogen plasma electrothermal gun is operational at 2 km/s with 10 mg hydrogen pellets; this facility has recently been equipped with a pulsed power supply capable of delivering 1.7 kJ millisecond pulses to low impedence arc loads.

  11. 3D laser inspection of fuel assembly grid spacers for nuclear reactors based on diffractive optical elements

    NASA Astrophysics Data System (ADS)

    Finogenov, L. V.; Lemeshko, Yu A.; Zav'yalov, P. S.; Chugui, Yu V.

    2007-06-01

    Ensuring the safety and high operation reliability of nuclear reactors takes 100% inspection of geometrical parameters of fuel assemblies, which include the grid spacers performed as a cellular structure with fuel elements. The required grid spacer geometry of assembly in the transverse and longitudinal cross sections is extremely important for maintaining the necessary heat regime. A universal method for 3D grid spacer inspection using a diffractive optical element (DOE), which generates as the structural illumination a multiple-ring pattern on the inner surface of a grid spacer cell, is investigated. Using some DOEs one can inspect the nomenclature of all produced grids. A special objective has been developed for forming the inner surface cell image. The problems of diffractive elements synthesis, projecting optics calculation, adjusting methods as well as calibration of the experimental measuring system are considered. The algorithms for image processing for different constructive elements of grids (cell, channel hole, outer grid spacer rim) and the experimental results are presented.

  12. Looking Southeast from Second Floor Mezzanine of Pellet Plant to ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Looking Southeast from Second Floor Mezzanine of Pellet Plant to Erbia Mixing Area and Poreformer and Acrawax Mixing Station - Hematite Fuel Fabrication Facility, Pellet Plant, 3300 State Road P, Festus, Jefferson County, MO

  13. Looking East on Third Floor of Pellet Plant Including Tops ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Looking East on Third Floor of Pellet Plant Including Tops of Line One and Blenders One, Two, and Three - Hematite Fuel Fabrication Facility, Pellet Plant, 3300 State Road P, Festus, Jefferson County, MO

  14. Tritium pellet injector for TFTR

    SciTech Connect

    Gouge, M.J.; Baylor, L.R.; Cole, M.J.; Combs, S.K.; Dyer, G.R.; Fehling, D.T.; Fisher, P.W.; Foust, C.R.; Langley, R.A.; Milora, S.L.; Qualls, A.L.; Wilgen, J.B.; Schmidt, G.L.; Barnes, G.W.; Persing, R.G.

    1992-06-01

    The tritium pellet injector (TPI) for the Tokamak Fusion Test Reactor (TFTR) will provide a tritium pellet fueling capability with pellet speeds in the 1- to 3-km/s range for the TFTR deuterium-tritium (D-T) phase. The existing TFTR deuterium pellet injector (DPI) has been modified at Oak Ridge National Laboratory (ORNL) to provide a four-shot, tritium-compatible, pipe-gun configuration with three upgraded single-stage pneumatic guns and a two-stage light gas gun driver. The TPI was designed to provide pellets ranging from 3.3 to 4.5 mm in diameter in arbitrarily programmable firing sequences at speeds up to approximately 1.5 km/s for the three single-stage drivers and 2.5 to 3 km/s for the two-stage driver. Injector operation is controlled by a programmable logic controller. The new pipe-gun injector assembly was installed in the modified DPI guard vacuum box, and modifications were made to the internals of the DPI vacuum injection line, including a new pellet diagnostics package. Assembly of these modified parts with existing DPI components was then completed, and the TPI was tested at ORNL with deuterium pellet. Results of the limited testing program at ORNL are described. The TPI is being installed on TFTR to support the D-D run period in 1992. In 1993, the tritium pellet injector will be retrofitted with a D-T fuel manifold and secondary tritium containment systems and integrated into TFTR tritium processing systems to provide full tritium pellet capability.

  15. Tritium pellet injector for TFTR

    SciTech Connect

    Gouge, M.J.; Baylor, L.R.; Cole, M.J.; Combs, S.K.; Dyer, G.R.; Fehling, D.T.; Fisher, P.W.; Foust, C.R.; Langley, R.A.; Milora, S.L.; Qualls, A.L.; Wilgen, J.B. ); Schmidt, G.L.; Barnes, G.W.; Persing, R.G. . Plasma Physics Lab.)

    1992-01-01

    The tritium pellet injector (TPI) for the Tokamak Fusion Test Reactor (TFTR) will provide a tritium pellet fueling capability with pellet speeds in the 1- to 3-km/s range for the TFTR deuterium-tritium (D-T) phase. The existing TFTR deuterium pellet injector (DPI) has been modified at Oak Ridge National Laboratory (ORNL) to provide a four-shot, tritium-compatible, pipe-gun configuration with three upgraded single-stage pneumatic guns and a two-stage light gas gun driver. The TPI was designed to provide pellets ranging from 3.3 to 4.5 mm in diameter in arbitrarily programmable firing sequences at speeds up to approximately 1.5 km/s for the three single-stage drivers and 2.5 to 3 km/s for the two-stage driver. Injector operation is controlled by a programmable logic controller. The new pipe-gun injector assembly was installed in the modified DPI guard vacuum box, and modifications were made to the internals of the DPI vacuum injection line, including a new pellet diagnostics package. Assembly of these modified parts with existing DPI components was then completed, and the TPI was tested at ORNL with deuterium pellet. Results of the limited testing program at ORNL are described. The TPI is being installed on TFTR to support the D-D run period in 1992. In 1993, the tritium pellet injector will be retrofitted with a D-T fuel manifold and secondary tritium containment systems and integrated into TFTR tritium processing systems to provide full tritium pellet capability.

  16. Qualitative comparison of bremsstrahlung X-rays and 800 MeV protons for tomography of urania fuel pellets

    SciTech Connect

    Morris, C. L.; Bourke, M.; Byler, D. D.; Chen, C. F.; Hogan, G.; Hunter, J. F.; Kwiatkowski, K.; Mariam, F. G.; McClellan, K. J.; Merrill, F.; Morley, D. J.; Saunders, A.

    2013-02-15

    We present an assessment of x-rays and proton tomography as tools for studying the time dependence of the development of damage in fuel rods. We also show data taken with existing facilities at Los Alamos National Laboratory that support this assessment. Data on surrogate fuel rods have been taken using the 800 MeV proton radiography (pRad) facility at the Los Alamos Neutron Science Center (LANSCE), and with a 450 keV bremsstrahlung X-ray tomography facility. The proton radiography pRad facility at LANSCE can provide good position resolution (<70 {mu}m has been demonstrate, 20 {mu}m seems feasible with minor changes) for tomography on activated fuel rods. Bremsstrahlung x-rays may be able to provide better than 100 {mu}m resolution but further development of sources, collimation, and detectors is necessary for x-rays to deal with the background radiation for tomography of activated fuel rods.

  17. Qualitative comparison of bremsstrahlung X-rays and 800 MeV protons for tomography of urania fuel pellets.

    PubMed

    Morris, C L; Bourke, M; Byler, D D; Chen, C F; Hogan, G; Hunter, J F; Kwiatkowski, K; Mariam, F G; McClellan, K J; Merrill, F; Morley, D J; Saunders, A

    2013-02-01

    We present an assessment of x-rays and proton tomography as tools for studying the time dependence of the development of damage in fuel rods. We also show data taken with existing facilities at Los Alamos National Laboratory that support this assessment. Data on surrogate fuel rods have been taken using the 800 MeV proton radiography (pRad) facility at the Los Alamos Neutron Science Center (LANSCE), and with a 450 keV bremsstrahlung X-ray tomography facility. The proton radiography pRad facility at LANSCE can provide good position resolution (<70 μm has been demonstrate, 20 μm seems feasible with minor changes) for tomography on activated fuel rods. Bremsstrahlung x-rays may be able to provide better than 100 μm resolution but further development of sources, collimation, and detectors is necessary for x-rays to deal with the background radiation for tomography of activated fuel rods.

  18. Qualitative comparison of bremsstrahlung X-rays and 800 MeV protons for tomography of urania fuel pellets

    NASA Astrophysics Data System (ADS)

    Morris, C. L.; Bourke, M.; Byler, D. D.; Chen, C. F.; Hogan, G.; Hunter, J. F.; Kwiatkowski, K.; Mariam, F. G.; McClellan, K. J.; Merrill, F.; Morley, D. J.; Saunders, A.

    2013-02-01

    We present an assessment of x-rays and proton tomography as tools for studying the time dependence of the development of damage in fuel rods. We also show data taken with existing facilities at Los Alamos National Laboratory that support this assessment. Data on surrogate fuel rods have been taken using the 800 MeV proton radiography (pRad) facility at the Los Alamos Neutron Science Center (LANSCE), and with a 450 keV bremsstrahlung X-ray tomography facility. The proton radiography pRad facility at LANSCE can provide good position resolution (<70 μm has been demonstrate, 20 μm seems feasible with minor changes) for tomography on activated fuel rods. Bremsstrahlung x-rays may be able to provide better than 100 μm resolution but further development of sources, collimation, and detectors is necessary for x-rays to deal with the background radiation for tomography of activated fuel rods.

  19. Qualitative comparison of bremsstrahlung X-rays and 800 MeV protons for tomography of urania fuel pellets

    SciTech Connect

    Morris, Christopher L.; Bourke, Mark A.; Byler, Darrin D.; Chen, Ching-Fong; Hogan, Gary E.; Hunter, James F.; Kwiatkowski, Kris K.; Mariam, Fesseha G.; McClellan, Kenneth J.; Merrill, Frank E.; Morley, Deborah J.; Saunders, Alexander

    2013-02-11

    We present an assessment of x-rays and proton tomography as tools for studying the time dependence of the development of damage in fuel rods. Also, we show data taken with existing facilities at Los Alamos National Laboratory that support this assessment. Data on surrogate fuel rods has been taken using the 800 MeV proton radiography (pRad) facility at the Los Alamos Neutron Science Center (LANSCE), and with a 450 keV bremsstrahlung X-ray tomography facility. The proton radiography pRad facility at LANSCE can provide good position resolution (<70 μm has been demonstrate, 20 μm seems feasible with minor changes) for tomography on activated fuel rods. Bremsstrahlung x-rays may be able to provide better than 100 μm resolution but further development of sources, collimation and detectors is necessary for x-rays to deal with the background radiation for tomography of activated fuel rods.

  20. A two-dimensional, finite-difference model of the oxidation of a uranium carbide fuel pellet

    SciTech Connect

    Shepherd, James; Fairweather, Michael; Hanson, Bruce C.; Heggs, Peter J.

    2015-12-31

    The oxidation of spent uranium carbide fuel, a candidate fuel for Generation IV nuclear reactors, is an important process in its potential reprocessing cycle. However, the oxidation of uranium carbide in air is highly exothermic. A model has therefore been developed to predict the temperature rise, as well as other useful information such as reaction completion times, under different reaction conditions in order to help in deriving safe oxidation conditions. Finite difference-methods are used to model the heat and mass transfer processes occurring during the reaction in two dimensions and are coupled to kinetics found in the literature.

  1. Unreviewed Safety Question Determination for TOPAZ II uranium fuel pellet production at the Plutonium Handling Facility (PF-4), Technical Area 55, Los Alamos National Laboratory

    SciTech Connect

    Gordon, D.J.P.

    1993-09-29

    Enriched uranium oxide, nitride, and carbide fuel pellets have been produced at PF-4 since the facility became operational in the late 1970s. The TOPAZ II reactors require fuel enriched to 97% uranium-235. Approximately 75 kilograms (kgs) of uranium will be processed per year in support of this program. The amount of fuel processed per year at PF-4 will not be increased for these programs, but the batch size will be increased to approximately 3 kgs of uranium. The current DOE-approved Final Safety Analysis Report (FSAR) calls for batches containing 45 grams (gms) of plutonium-239 and 172 gms of uranium-235. The impact of increasing the uranium batch size on the facility authorization basis is analyzed in the attached Safety Evaluation Worksheet. In addition, the structural modification for the transformer and vacuum pump installation, required to support the operation, is evaluated. Based on the attached Safety Evaluation, it has been determined that the change in uranium batch size does not constitute an Unreviewed Safety Question (USQ), the increase in uranium batch size does not increase the probability or consequences of any accidents previously analyzed and does not create the possibility for a new type of accident or reduce the margin of safety in the Operational Safety Requirements (OSRs). Similarly, the structural modifications required for the transformer and vacuum pump installation do not increase the probability or consequence of any accident previously analyzed and do not create the possibility for a new type of accident or reduce any margin of safety in the OSRS.

  2. Qualitative comparison of bremsstrahlung X-rays and 800 MeV protons for tomography of urania fuel pellets

    DOE PAGES

    Morris, Christopher L.; Bourke, Mark A.; Byler, Darrin D.; ...

    2013-02-11

    We present an assessment of x-rays and proton tomography as tools for studying the time dependence of the development of damage in fuel rods. Also, we show data taken with existing facilities at Los Alamos National Laboratory that support this assessment. Data on surrogate fuel rods has been taken using the 800 MeV proton radiography (pRad) facility at the Los Alamos Neutron Science Center (LANSCE), and with a 450 keV bremsstrahlung X-ray tomography facility. The proton radiography pRad facility at LANSCE can provide good position resolution (<70 μm has been demonstrate, 20 μm seems feasible with minor changes) for tomographymore » on activated fuel rods. Bremsstrahlung x-rays may be able to provide better than 100 μm resolution but further development of sources, collimation and detectors is necessary for x-rays to deal with the background radiation for tomography of activated fuel rods.« less

  3. Pellet injector development and experiments at ORNL

    SciTech Connect

    Baylor, L.R.; Argo, B.E.; Barber, G.C.; Combs, S.K.; Cole, M.J.; Dyer, G.R.; Fehling, D.T.; Fisher, P.W.; Foster, C.A.; Foust, C.R.; Gouge, M.J.; Jernigan, T.C.; Langley, R.A.; Milora, S.L.; Qualls, A.L.; Schechter, D.E.; Sparks, D.O.; Tsai, C.C.; Wilgen, J.B.; Whealton, J.H.

    1993-11-01

    The development of pellet injectors for plasma fueling of magnetic confinement fusion experiments has been under way at Oak Ridge National Laboratory (ORNL) for the past 15 years. Recently, ORNL provided a tritium-compatible four-shot pneumatic injector for the Tokamak Fusion Test Reactor (TFTR) based on the in situ condensation technique that features three single-stage gas guns and an advanced two-stage light gas gun driver. In another application, ORNL supplied the Tore Supra tokamak with a centrifuge pellet injector in 1989 for pellet fueling experiments that has achieved record numbers of injected pellets into a discharge. Work is progressing on an upgrade to that injector to extend the number of pellets to 400 and improve pellet repeatability. In a new application, the ORNL three barrel repeating pneumatic injector has been returned from JET and is being readied for installation on the DIII-D device for fueling and enhanced plasma performance experiments. In addition to these experimental applications, ORNL is developing advanced injector technologies, including high-velocity pellet injectors, tritium pellet injectors, and long-pulse feed systems. The two-stage light gas gun and electron-beam-driven rocket are the acceleration techniques under investigation for achieving high velocity. A tritium proof-of-principle (TPOP) experiment has demonstrated the feasibility of tritium pellet production and acceleration. A new tritium-compatible, extruder-based, repeating pneumatic injector is being fabricated to replace the pipe gun in the TPOP experiment and will explore issues related to the extrudability of tritium and acceleration of large tritium pellets. The tritium pellet formation experiments and development of long-pulse pellet feed systems are especially relevant to the International Tokamak Engineering Reactor (ITER).

  4. Current generation by phased injection of pellets

    SciTech Connect

    Fisch, N.J.

    1983-08-01

    By phasing the injection of frozen pellets into a tokamak plasma, it is possible to generate current. The current occurs when the electron flux to individual members of an array of pellets is asymmetric with respect to the magnetic field. The utility of this method for tokamak reactors, however, is unclear; the current, even though free in a pellet-fueled reactor, may not be large enough to be worth the trouble. Uncertainty as to the utility of this method is, in part, due to uncertainty as to proper modeling of the one-pellet problem.

  5. FUEL ELEMENT FOR A NEUTRONIC REACTOR

    DOEpatents

    McGeary, R.K.; Winslow, F.R.

    1963-08-13

    A method of making fuel elements wherein several individual fuel pellets are positioned into a cladding tube and the tape stretched longitudinally until the cladding tube grips each pellet and, in addition, necks down between each pellet is described. (AEC)

  6. Large area quantitative X-ray mapping of (U,Pu)O 2 nuclear fuel pellets using wavelength dispersive electron probe microanalysis

    NASA Astrophysics Data System (ADS)

    Brémier, S.; Haas, D.; Somers, J.; Walker, C. T.

    2003-04-01

    The work presented is an example of how large area compositional mapping (≥1 mm 2) can be used to provide quantitative information on element distribution and specimen homogeneity. High-resolution was accomplished by producing a collage of X-ray maps acquired using classical conditions; magnification ×400, spatial resolution 256×256 pixels. The individual images, each measuring roughly 250×250 μm, were converted to quantitative maps using the HIMAX® software package and the XMAS® matrix correction from SAMx. The quantitative gray-level large area X-ray picture was pieced together using the 'Multiple Image Alignment' function of the ANALYSIS® image processing software. This software was also used to convert the gray-level pictures to false color images. The specimens investigated were transverse sections of MOX fuel pellets. Results are presented for the distribution of Pu by area fraction and cumulative area fraction, the size distribution of regions of high Pu concentration and average separation of these regions.

  7. Mitigation of divertor heat flux by high-frequency ELM pacing with non-fuel pellet injection in DIII-D

    DOE PAGES

    Bortolon, A.; Maingi, R.; Mansfield, D. K.; ...

    2017-03-23

    Experiments have been conducted on DIII-D investigating high repetition rate injection of non-fuel pellets as a tool for pacing Edge Localized Modes (ELMs) and mitigating their transient divertor heat loads. Effective ELM pacing was obtained with injection of Li granules in different H-mode scenarios, at frequencies 3–5 times larger than the natural ELM frequency, with subsequent reduction of strike-point heat flux. However, in scenarios with high pedestal density (~6 × 1019 m–3), the magnitude of granule triggered ELMs shows a broad distribution, in terms of stored energy loss and peak heat flux, challenging the effectiveness of ELM mitigation. Furthermore, transientmore » heat-flux deposition correlated with granule injections was observed far from the strike-points. As a result, field line tracing suggest this phenomenon to be consistent with particle loss into the mid-plane far scrape-off layer, at toroidal location of the granule injection.« less

  8. Solid deuterium centrifuge pellet injector

    SciTech Connect

    Foster, C.A.

    1982-01-01

    Pellet injectors are needed to fuel long pulse tokamak plasmas and other magnetic confinement devices. For this purpose, an apparatus has been developed that forms 1.3-mm-diam pellets of frozen deuterium at a rate of 40 pellets per second and accelerates them to a speed of 1 km/s. Pellets are formed by extruding a billet of solidified deuterium through a 1.3-mm-diam nozzle at a speed of 5 cm/s. The extruding deuterium is chopped with a razor knife, forming 1.3-mm right circular cylinders of solid deuterium. The pellets are accelerated by synchronously injecting them into a high speed rotating arbor containing a guide track, which carries them from a point near the center of rotation to the periphery. The pellets leave the wheel after 150/sup 0/ of rotation at double the tip speed. The centrifuge is formed in the shape of a centrifugal catenary and is constructed of high strength KEVLAR/epoxy composite. This arbon has been spin-tested to a tip speed of 1 km/s.

  9. Dielectric Properties of Peanut-hull Pellets at Microwave Frequencies

    USDA-ARS?s Scientific Manuscript database

    Peanut-hull pellets are obtained from a waste product, peanut-hulls, which after pelleting can have several uses, namely as a renewable fuel. Rapid and nondestructive characterization of peanut-hull pellets is important for industrial utilization of this resource. Properties such as water content an...

  10. Fabrication, inspection, and test plan for the Advanced Test Reactor (ATR) Mixed-Oxide (MOX) fuel irradiation project

    SciTech Connect

    Wachs, G.W.

    1997-11-01

    The Department of Energy (DOE) Fissile Materials Disposition Materials Disposition Program (FMDP) has announced that reactor irradiation of MOX fuel is one of the preferred alternatives for disposal of surplus weapons-usable plutonium (Pu). MOX fuel has been utilized domestically in test reactors and on an experimental basis in a number of Commercial Light Water Reactors (CLWRs). Most of this experience has been with Pu derived from spent low enriched uranium (LEU) fuel, known as reactor grade (RG) Pu. The MOX fuel test will be irradiated in the ATR to provide preliminary data to demonstrate that the unique properties of surplus weapons-derived or weapons-grade (WG) plutonium (Pu) do not compromise the applicability of this MOX experience base. In addition, the test will contribute experience with irradiation of gallium-containing fuel to the data base required for resolution of generic CLWR fuel design issues (ORNL/MD/LTR-76). This Fabrication, Inspection, and Test Plan (FITP) is a level 2 document as defined in the FMDP LWR MOX Fuel Irradiation Test Project Plan (ORNL/MD/LTR-78).

  11. Application of railgun principle to high-velocity hydrogen pellet injection for magnetic fusion reactor fueling. Progress report, August 16, 1991--September 30, 1992

    SciTech Connect

    Kim, K.; Zhang, J.

    1992-12-01

    Three separate papers are included which report research progress during this period: (1) A new railgun configuration with perforated sidewalls, (2) development of a fuseless small-bore railgun for injection of high-speed hydrogen pellets into magnetically confined plasmas, and (3) controls and diagnostics on a fuseless railgun for solid hydrogen pellet injection.

  12. A new fast neutron collar for safeguards inspection measurements of fresh low enriched uranium fuel assemblies containing burnable poison rods

    NASA Astrophysics Data System (ADS)

    Evans, Louise G.; Swinhoe, Martyn T.; Menlove, Howard O.; Schwalbach, Peter; Baere, Paul De; Browne, Michael C.

    2013-11-01

    Safeguards inspection measurements must be performed in a timely manner in order to detect the diversion of significant quantities of nuclear material. A shorter measurement time can increase the number of items that a nuclear safeguards inspector can reliably measure during a period of access to a nuclear facility. In turn, this improves the reliability of the acquired statistical sample, which is used to inform decisions regarding compliance. Safeguards inspection measurements should also maintain independence from facility operator declarations. Existing neutron collars employ thermal neutron interrogation for safeguards inspection measurements of fresh fuel assemblies. A new fast neutron collar has been developed for safeguards inspection measurements of fresh low-enriched uranium (LEU) fuel assemblies containing gadolinia (Gd2O3) burnable poison rods. The Euratom Fast Collar (EFC) was designed with high neutron detection efficiency to make a fast (Cd) mode measurement viable whilst meeting the high counting precision and short assay time requirements of the Euratom safeguards inspectorate. A fast mode measurement reduces the instrument sensitivity to burnable poison rod content and therefore reduces the applied poison correction, consequently reducing the dependence on the operator declaration of the poison content within an assembly. The EFC non-destructive assay (NDA) of typical modern European pressurized water reactor (PWR) fresh fuel assembly designs have been simulated using Monte Carlo N-particle extended transport code (MCNPX) simulations. Simulations predict that the EFC can achieve 2% relative statistical uncertainty on the doubles neutron counting rate for a fast mode measurement in an assay time of 600 s (10 min) with the available 241AmLi (α,n) interrogation source strength of 5.7×104 s-1. Furthermore, the calibration range of the new collar has been extended to verify 235U content in variable PWR fuel designs in the presence of up to 32

  13. Development of Inspection for Friction Stir Welds for Rocket Fuel Tanks

    NASA Technical Reports Server (NTRS)

    Russell, Samuel S.

    2012-01-01

    During development of the Ares I weld processes nondestructive and destructive testing were used to identify and characterize defects that occurred. These defects were named and character noted. This catalogue of defects and characteristics was then used to develop inspection methods for Self Reacting Friction Stir Welds (SR ]FSW) and Conventional Friction Stir Welds (C ]FSW). Dye penetrant, eddy current, x ]radiography, single element ultrasonic, and phased array ultrasonic (PAUT) inspection procedures were developed to target the expected defects. Once the method procedure was developed a comparison was performed to allow for selection of the best inspection method. Tests of the effectiveness of the inspection were performed on purposely fabricated flawed specimens and electrodischarge machined notches. The initial test results prompted a revisit of the PAUT procedure and a redesign of the inspection. Subsequent testing showed that a multi ]angle PAUT inspection resulted in better detection capability. A discussion of the most effective orientations of the PAUT transducer will be presented. Also, the implementation of the inspection on production hardware will be presented. In some cases the weld tool is used as the transducer manipulator and in some cases a portable scanner is used

  14. Large Scale Shearography Inspection of the Space Shuttle External Fuel Tank

    NASA Technical Reports Server (NTRS)

    Ussery, Warren; Scheurer, Phillip; Rivers, Joanna; Walker, James; Lovell, Donald

    2010-01-01

    Shearography was successfully used to inspect the damaged region of ET122 for nonvisible damage. The shearography inspection was extensive covering over 3100 square feet of foam and lasting 9 months. Most foam damage was visible and shearography results confirmed that foam damage in visibly impacted regions did not extend outside the area with visible damage. Of the 21 nonvisible defect indications detected with shearography, none were determined to be actual foam damage. Inspections were intentionally conservative since no experience base was available for debris damaged foam. Shearography results were used in conjunction with tactile and visual inspection to support the acceptance of the foam application allowing the tank to move forward for refurbishment.

  15. Modeling of a Hydrogenic Pellet Production System

    NASA Astrophysics Data System (ADS)

    Leachman, J. W.; Pfotenhauer, J. M.; Nellis, G. F.

    2010-04-01

    Solid hydrogenic pellets are used as fuel for fusion energy machines like the ITER device. This paper discusses the numerical modeling of a Pellet Production System (PPS) that is used to generate these pellets. The PPS utilizes a source of supercritical helium to provide the cooling that is necessary to precool, liquefy, and solidify hydrogenic material that is ultimately extruded and cut into fuel pellets. The specific components within the PPS include a pre-cooling heat exchanger, a liquefier, and a twin-screw solidifying extruder. This paper presents numerical models of each component. These numerical models are used as design tools to predict the performance of the respective devices. The performance of the PPS is dominated by the heat transfer coefficient and viscous dissipation associated with the solidifying hydrogenic fluid in the twin-screw extruder. This observation motivates experimental efforts aimed at precise measurement of these quantities.

  16. Pelletization process of postproduction plant waste

    NASA Astrophysics Data System (ADS)

    Obidziński, S.

    2012-07-01

    The results of investigations on the influence of material, process, and construction parameters on the densification process and density of pellets received from different mixtures of tobacco and fine-grained waste of lemon balm are presented. The conducted research makes it possible to conclude that postproduction waste eg tobacco and lemon balm wastes can be successfully pelletized and used as an ecological, solid fuels.

  17. Pneumatic pellet injector research at ORNL

    SciTech Connect

    Milora, S.L.; Combs, S.K.; Foster, C.A.; Schuresko, D.D.; Gouge, M.J.; Fisher, P.W.; Argo, B.E.; Barber, G.C.; Fehling, D.T.; Foust, C.R.

    1988-01-01

    Advanced pneumatic-injector-based pellet fueling systems are under development at Oak Ridge National Laboratory (ORNL) for fueling magnetically confined plasmas. The general approach is that of producing and accelerating frozen hydrogen isotope pellets at speeds in the range from 1 to 2 km/s and higher. Recently, ORNL provided pneumatic-based pellet fueling systems for the Tokamak Fusion Test Reactor (TFTR) and the Joint European Torus (JET), and a new simplified eight-shot injector has been developed for use on the Princeton Beta Experiment (PBX) and the Advanced Toroidal Facility (ATF). These long-pulse devices operate reliably at up to 1.5 km/s with pellet sizes ranging between 1 and 6 mm. In addition to these activities, ORNL is pursuing advanced technologies such as the electrothermal gun and the two-stage light-gas gun to achieve pellet velocities significantly in excess of 2 km/s and is carrying out a tritium proof-of-principle (TPOP) experiment in which the fabrication and acceleration of tritium pellets to 1.4 km/s were recently demonstrated. 27 refs., 10 figs.

  18. Planning Document for Spent Nuclear Fuel (SNF) Cleanliness Inspection Process (OCRWM)

    SciTech Connect

    PITNER, A.L.

    2000-12-06

    The Fuel Retrieval System (FRS) Process Validation Procedure (Stegen 2000) requires that a specified quantity of fuel processed through the Primary Cleaning Machine (PCM) be assessed for cleanliness during initial operational and process validation testing. Specifically, these assessments are visual examinations of the fuel, performed to confirm that the PCM adequately cleans the fuel elements of canister sludge. The results of these examinations will be used to demonstrate that residual quantities of canister particulate on fuel elements loaded into Multi-Canister Overpacks (MCOs) are within projected levels used to establish safety basis limits (Sloughter 2000). The fuel assessments, performed as part of the validation process, will be conducted during the Hot Operations portion of the Phased Startup Initiative (PSI) of the Fuel Retrieval and Integrated Water Treatment Systems (Pajunen 2000). Hot Operations testing constitutes Phases 3 and 4 of the PSI. The fuel assemblies in all candidate canisters will be thoroughly examined during these test phases (highly degraded fuel assemblies that qualify as scrap are exempt from evaluation). During subsequent production operation of the FRS, only periodic examinations for cleanliness will be performed and documented. This document describes the specific processes and techniques that will be applied in performing the cleanliness assessments, and the methodology used to verify that the documented assessment results conform to Office of Civilian Radioactive Waste Management (OCRWM) requirements. The procedures and processes presented here are in conformance with the Quality Assurance Program Plan for Implementation of the OCRWM Quality Assurance Requirements and Description (QARD) for the Spent Nuclear Fuel (SNF) Project (QAPP-OCRWM-001).

  19. Pellet ablation and temperature profile measurements in TFTR

    SciTech Connect

    Owens, D.K.; Schmidt, G.L.; Cavallo, A.; Grek, B.; Hulse, R.; Johnson, D.; Mansfield, D.; McNeill, D.; Park, H.; Taylor, G.

    1988-01-01

    Single and multiple deuterium pellets have been injected into a variety of TFTR plasmas, including ohmically heated plasmas with wide range of electron temperatures, neutral beam heated plasmas at several NBI powers and high T/sub e/, post NBI plasmas. Pellet penetration into these plasmas was determined by measuring the pellet speed and duration of the H/sub ..cap alpha..//D/sub ..cap alpha../ light emission during pellet ablation in the plasma. These penetration measurements are compared to the predicted penetration computed using the ablation model developed by Oak Ridge National Laboratory. The plasma density profiles before and after pellet injection are used to estimate the number of particles deposited in the plasma. The plasma particle increase compared to the estimated number of atoms in the pellet yields a measure of the fueling efficiency of pellets in TFTR. The ablation cloud parameters are discussed based on polychromater measurements of the H/sub ..cap alpha..//D/sub ..cap alpha../ line emission from the neutral cloud surrounding the pellet. The electron temperature profile evolution after pellet injection is examined for the case of multiple pellet injection into an ohmically heated plasma. The ORNL pellet ablation code was used to compare measured pellet penetration depths with a theoretical model. The measured input parameters to the model are the electron density and temperature profiles, the neutral beam heating profile, the neutral density profile, the pellet size, pellet speed and pellet composition. The free parameter in the model is the thickness of the neutral cloud surrounding the pellet. This parameter is adjusted to arrive at a reasonable agreement between measured and calculated pellet penetration depths. The output of the model which is directly comparable to experiment is the calculated ablation rate. It is assumed that the broad-band H/sub ..cap alpha..//D/sub ..cap alpha../ emission is proportional to the ablation rate.

  20. 75 FR 44817 - Notice of Availability of Uranium Enrichment Fuel Cycle Facility Inspection Reports Regarding...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-29

    ... reviews of how classified matter is protected at the facility as well as reviews of classified computer networks. These inspection reports have not been listed in this Notice because they are not available... to pdr.resource@nrc.gov . These documents may also be viewed electronically on the public computers...

  1. 78 FR 63518 - Uranium Enrichment Fuel Cycle Inspection Reports Regarding Louisiana Energy Services, National...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-24

    ..., and components designed to support safe operation of Autoclave 2 of the facility have been constructed... Enrichment Facility, Eunice, New Mexico, Prior to the Commencement of Operations AGENCY: Nuclear Regulatory... conducted inspections of the Louisiana Energy Services (LES), LLC, National Enrichment Facility in Eunice...

  2. Cryogenic pellet production developments for long-pulse plasma operation

    SciTech Connect

    Meitner, S. J.; Baylor, L. R.; Combs, S. K.; Fehling, D. T.; McGill, J. M.; Duckworth, R. C.; McGinnis, W. D.; Rasmussen, D. A.

    2014-01-29

    Long pulse plasma operation on large magnetic fusion devices require multiple forms of cryogenically formed pellets for plasma fueling, on-demand edge localized mode (ELM) triggering, radiative cooling of the divertor, and impurity transport studies. The solid deuterium fueling and ELM triggering pellets can be formed by extrusions created by helium cooled, twin-screw extruder based injection system that freezes deuterium in the screw section. A solenoid actuated cutter mechanism is activated to cut the pellets from the extrusion, inserting them into the barrel, and then fired by the pneumatic valve pulse of high pressure gas. Fuel pellets are injected at a rate up to 10 Hz, and ELM triggering pellets are injected at rates up to 20 Hz. The radiative cooling and impurity transport study pellets are produced by introducing impurity gas into a helium cooled section of a pipe gun where it deposits in-situ. A pneumatic valve is opened and propellant gas is released downstream where it encounters a passive punch which initially accelerates the pellet before the gas flow around the finishes the pellet acceleration. This paper discusses the various cryogenic pellet production techniques based on the twin-screw extruder, pipe gun, and pellet punch designs.

  3. Nuclear fuel element

    DOEpatents

    Zocher, Roy W.

    1991-01-01

    A nuclear fuel element and a method of manufacturing the element. The fuel element is comprised of a metal primary container and a fuel pellet which is located inside it and which is often fragmented. The primary container is subjected to elevated pressure and temperature to deform the container such that the container conforms to the fuel pellet, that is, such that the container is in substantial contact with the surface of the pellet. This conformance eliminates clearances which permit rubbing together of fuel pellet fragments and rubbing of fuel pellet fragments against the container, thus reducing the amount of dust inside the fuel container and the amount of dust which may escape in the event of container breach. Also, as a result of the inventive method, fuel pellet fragments tend to adhere to one another to form a coherent non-fragmented mass; this reduces the tendency of a fragment to pierce the container in the event of impact.

  4. Pelletization of fine coals. Final report

    SciTech Connect

    Sastry, K.V.S.

    1995-12-31

    Coal is one of the most abundant energy resources in the US with nearly 800 million tons of it being mined annually. Process and environmental demands for low-ash, low-sulfur coals and economic constraints for high productivity are leading the coal industry to use such modern mining methods as longwall mining and such newer coal processing techniques as froth flotation, oil agglomeration, chemical cleaning and synthetic fuel production. All these processes are faced with one common problem area--fine coals. Dealing effectively with these fine coals during handling, storage, transportation, and/or processing continues to be a challenge facing the industry. Agglomeration by the unit operation of pelletization consists of tumbling moist fines in drums or discs. Past experimental work and limited commercial practice have shown that pelletization can alleviate the problems associated with fine coals. However, it was recognized that there exists a serious need for delineating the fundamental principles of fine coal pelletization. Accordingly, a research program has been carried involving four specific topics: (i) experimental investigation of coal pelletization kinetics, (ii) understanding the surface principles of coal pelletization, (iii) modeling of coal pelletization processes, and (iv) simulation of fine coal pelletization circuits. This report summarizes the major findings and provides relevant details of the research effort.

  5. Pellet acceleration using an ablation-controlled electrothermal launcher

    SciTech Connect

    Kincaid, R.W.; Bourham, M.A.; Gilligan, J.G.

    1995-12-31

    The NCSU ablation-controlled electrothermal launcher SIRENS has been used to accelerate plastic (Lexan polycarbonate) pellets to investigate the possibility of using electrothermal launchers as frozen pellet injectors for tokamak fueling. Successful installation of such a device would include a protective shell (sabot) to shield the hydrogenic pellet from ablation and allow it to maintain its integrity throughout the acceleration. The SIRENS device has been modified to include specially designed barrel sections equipped with diagnostic ports.

  6. Tritium proof-of-principle pellet injector: Phase 2

    NASA Astrophysics Data System (ADS)

    Fisher, P. W.; Gouge, M. J.

    1995-03-01

    As part of the International Thermonuclear Engineering Reactor (ITER) plasma fueling development program, Oak Ridge National Laboratory (ORNL) has fabricated a pellet injection system to test the mechanical and thermal properties of extruded tritium. This repeating, single-stage, pneumatic injector, called the Tritium-Proof-of-Principle Phase-2 (TPOP-2) Pellet Injector, has a piston-driven mechanical extruder and is designed to extrude hydrogenic pellets sized for the ITER device. The TPOP-II program has the following development goals: evaluate the feasibility of extruding tritium and DT mixtures for use in future pellet injection systems; determine the mechanical and thermal properties of tritium and DT extrusions; integrate, test and evaluate the extruder in a repeating, single-stage light gas gun sized for the ITER application (pellet diameter approximately 7-8 mm); evaluate options for recycling propellant and extruder exhaust gas; evaluate operability and reliability of ITER prototypical fueling systems in an environment of significant tritium inventory requiring secondary and room containment systems. In initial tests with deuterium feed at ORNL, up to thirteen pellets have been extruded at rates up to 1 Hz and accelerated to speeds of order 1.0-1.1 km/s using hydrogen propellant gas at a supply pressure of 65 bar. The pellets are typically 7.4 mm in diameter and up to 11 mm in length and are the largest cryogenic pellets produced by the fusion program to date. These pellets represent about a 11% density perturbation to ITER. Hydrogenic pellets will be used in ITER to sustain the fusion power in the plasma core and may be crucial in reducing first wall tritium inventories by a process called isotopic fueling where tritium-rich pellets fuel the burning plasma core and deuterium gas fuels the edge.

  7. Deuterium pellet injector gun design

    SciTech Connect

    Lunsford, R.V.; Wysor, R.B.; Bryan, W.E.; Shipley, W.D.; Combs, S.K.; Foust, C.R.; Milora, S.L.; Fisher, P.W.

    1985-01-01

    The Deuterium Pellet Injector (DPI), an eight-pellet pneumatic injector, is being designed and fabricated for the Tokamak Fusion Test Reactor (TFTR). It will accelerate eight pellets, 4 by 4 mm maximum, to greater than 1500 m/s. It utilizes a unique pellet-forming mechanism, a cooled pellet storage wheel, and improved propellant gas scavenging.

  8. At a Glance – Pelleting of DDGS

    USDA-ARS?s Scientific Manuscript database

    NCARL is proud of its active partnership among industry, academic, and extension specialists, and we continue to pursue improved uses and values for distillers grain. We aim to augment both the livestock industry as well as fuel ethanol manufacturers with our research programs. Pelleting is one wa...

  9. Carbonaceous pellets and method of pelletizing

    SciTech Connect

    Dondelewski, M.A.

    1982-11-02

    A method is claimed for pelletizing carbonaceous materials including bonding coal fines and lignite coal with a polymeric hydrocarbon binder having reactive sites thereon. For example, with tall oil pitch and the like, in the case of coal, the binder is applied by slurrying the fine coal with the pitch. In the case of lignite, the binder is directly applied to the pulverized material. By action of rolling and tumbling, for example, large agglomerates are formed. With drying and heating, strong water-resistant pellets are formed which have the extremely desirable property of being easily repulverized.

  10. New Pellet Injection Schemes on DIII-D

    SciTech Connect

    Anderson, P.M.; Baylor, L.R.; Combs, S.K.; Foust, C.R.; Jernigan, T.C.; Robinson, J.I.

    1999-11-13

    The pellet fueling system on DIII-D has been modified for injection of deuterium pellets from two vertical ports and two inner wall locations on the magnetic high-field side (HFS) of the tokamak. The HFS pellet injection technique was first employed on ASDEX-Upgrade with significant improvements reported in both pellet penetration and fueling efficiency. The new pellet injection schemes on DIII-D required the installation of new guide tubes. These lines are {approx_equal}12.5 m in total length and are made up of complex bends and turns (''roller coaster'' like) to route pellets from the injector to the plasma, including sections inside the torus. The pellet speed at which intact pellets can survive through the curved guide tubes is limited ({approx_equal}200-300 m/s for HFS injection schemes). Thus, one of the three gas guns on the injector was modified to provide pellets in a lower speed regime than the original guns (normal speed range {approx_equal}500 to 1000 m/s). The guide tube installations and gun modifications are described along with the injector operating parameters, and the latest test results are highlighted.

  11. Reciprocating pellet press

    DOEpatents

    Jones, Charles W.

    1981-04-07

    A machine for pressing loose powder into pellets using a series of reciprocating motions has an interchangeable punch and die as its only accurately machines parts. The machine reciprocates horizontally between powder receiving and pressing positions. It reciprocates vertically to press, strip and release a pellet.

  12. Development of Impregnated Agglomerate Pelletization (IAP) process for fabrication of (Th,U)O 2 mixed oxide pellets

    NASA Astrophysics Data System (ADS)

    Khot, P. M.; Nehete, Y. G.; Fulzele, A. K.; Baghra, Chetan; Mishra, A. K.; Afzal, Mohd.; Panakkal, J. P.; Kamath, H. S.

    2012-01-01

    Impregnated Agglomerate Pelletization (IAP) technique has been developed at Advanced Fuel Fabrication Facility (AFFF), BARC, Tarapur, for manufacturing (Th, 233U)O 2 mixed oxide fuel pellets, which are remotely fabricated in hot cell or shielded glove box facilities to reduce man-rem problem associated with 232U daughter radionuclides. This technique is being investigated to fabricate the fuel for Indian Advanced Heavy Water Reactor (AHWR). In the IAP process, ThO 2 is converted to free flowing spheroids by powder extrusion route in an unshielded facility which are then coated with uranyl nitrate solution in a shielded facility. The dried coated agglomerate is finally compacted and then sintered in oxidizing/reducing atmosphere to obtain high density (Th,U)O 2 pellets. In this study, fabrication of (Th,U)O 2 mixed oxide pellets containing 3-5 wt.% UO 2 was carried out by IAP process. The pellets obtained were characterized using optical microscopy, XRD and alpha autoradiography. The results obtained were compared with the results for the pellets fabricated by other routes such as Coated Agglomerate Pelletization (CAP) and Powder Oxide Pelletization (POP) route.

  13. Inspection and Gamma-Ray Dose Rate Measurements of the Annulus of the VSC-17 Concrete Spent Nuclear Fuel Storage Cask

    SciTech Connect

    P. L. Winston

    2007-09-01

    The air cooling annulus of the Ventilated Storage Cask (VSC)-17 spent fuel storage cask was inspected using a Toshiba 7 mm (1/4”) CCD video camera. The dose rates observed in the annular space were measured to provide a reference for the activity to which the camera(s) being tested were being exposed. No gross degradation, pitting, or general corrosion was observed.

  14. Pellet plant energy simulator

    NASA Astrophysics Data System (ADS)

    Bordeasu, D.; Vasquez Pulido, T.; Nielsen, C.

    2016-02-01

    The Pellet Plant energy simulator is a software based on advanced algorithms which has the main purpose to see the response of a pellet plant regarding certain location conditions. It combines energy provided by a combined heat and power, and/or by a combustion chamber with the energy consumption of the pellet factory and information regarding weather conditions in order to predict the biomass consumption of the pellet factory together with the combined heat and power, and/or with the biomass consumption of the combustion chamber. The user of the software will not only be able to plan smart the biomass acquisition and estimate its cost, but also to plan smart the preventive maintenance (charcoal cleaning in case of a gasification plant) and use the pellet plant at the maximum output regarding weather conditions and biomass moisture. The software can also be used in order to execute a more precise feasibility study for a pellet plant in a certain location. The paper outlines the algorithm that supports the Pellet Plant Energy Simulator idea and presents preliminary tests results that supports the discussion and implementation of the system

  15. Lignite pellets and methods of agglomerating or pelletizing

    DOEpatents

    Baker, Albert F.; Blaustein, Eric W.; Deurbrouck, Albert W.; Garvin, John P.; McKeever, Robert E.

    1981-01-01

    The specification discloses lignite pellets which are relatively hard, dust resistant, of generally uniform size and free from spontaneous ignition and general degradation. Also disclosed are methods for making such pellets which involve crushing as mined lignite, mixing said lignite with a binder such as asphalt, forming the lignite binder mixture into pellets, and drying the pellets.

  16. Design of pellet surface grooves for fission gas plenum

    SciTech Connect

    Carter, T.J.; Jones, L.R.; Macici, N.; Miller, G.C.

    1986-01-01

    In the Canada deuterium uranium pressurized heavy water reactor, short (50-cm) Zircaloy-4 clad bundles are fueled on-power. Although internal void volume within the fuel rods is adequate for the present once-through natural uranium cycle, the authors have investigated methods for increasing the internal gas storage volume needed in high-power, high-burnup, experimental ceramic fuels. This present work sought to prove the methodology for design of gas storage volume within the fuel pellets - specifically the use of grooves pressed or machined into the relatively cool pellet/cladding interface. Preanalysis and design of pellet groove shape and volume was accomplished using the TRUMP heat transfer code. Postirradiation examination (PIE) was used to check the initial design and heat transfer assumptions. Fission gas release was found to be higher for the grooved pellet rods than for the comparison rods with hollow or unmodified pellets. This had been expected from the initial TRUMP thermal analyses. The ELESIM fuel modeling code was used to check in-reactor performance, but some modifications were necessary to accommodate the loss of heat transfer surface to the grooves. It was concluded that for plenum design purposes, circumferential pellet grooves could be adequately modeled by the codes TRUMP and ELESIM.

  17. ELM mitigation with pellet ELM triggering and implications for PFCs and plasma performance in ITER

    DOE PAGES

    Baylor, Larry R.; Lang, P. T.; Allen, Steve L.; ...

    2014-10-05

    The triggering of rapid small edge localized modes (ELMs) by high frequency pellet injection has been proposed as a method to prevent large naturally occurring ELMs that can erode the ITER plasma facing components. Deuterium pellet injection has been used to successfully demonstrate the on-demand triggering of edge localized modes (ELMs) at much higher rates and with much smaller intensity than natural ELMs. The proposed hypothesis for the triggering mechanism of ELMs by pellets is the local pressure perturbation resulting from reheating of the pellet cloud that can exceed the local high-n ballooning mode threshold where the pellet is injected.more » Nonlinear MHD simulations of the pellet ELM triggering show destabilization of high-n ballooning modes by such a local pressure perturbation. A review of the recent pellet ELM triggering results from ASDEX Upgrade (AUG), DIII-D, and JET reveals that a number of uncertainties about this ELM mitigation technique still remain. These include the heat flux impact pattern on the divertor and wall from pellet triggered and natural ELMs, the necessary pellet size and injection location to reliably trigger ELMs, and the level of fueling to be expected from ELM triggering pellets and synergy with larger fueling pellets. The implications of these issues for pellet ELM mitigation in ITER and its impact on the PFCs are presented along with the design features of the pellet injection system for ITER.« less

  18. ELM mitigation with pellet ELM triggering and implications for PFCs and plasma performance in ITER

    SciTech Connect

    Baylor, Larry R.; Lang, P. T.; Allen, Steve L.; Combs, S. K.; Commaux, N.; Evans, Todd E.; Fenstermacher, Max E.; Huijsmans, G.; Jernigan, T. C.; Lasnier, Charles J.; Leonard, Anthony W.; Loarte, Alberto; Maingi, Rajesh; Maruyama, S.; Meitner, S. J.; Moyer, Richard A.; Osborne, Thomas H.

    2014-10-05

    The triggering of rapid small edge localized modes (ELMs) by high frequency pellet injection has been proposed as a method to prevent large naturally occurring ELMs that can erode the ITER plasma facing components. Deuterium pellet injection has been used to successfully demonstrate the on-demand triggering of edge localized modes (ELMs) at much higher rates and with much smaller intensity than natural ELMs. The proposed hypothesis for the triggering mechanism of ELMs by pellets is the local pressure perturbation resulting from reheating of the pellet cloud that can exceed the local high-n ballooning mode threshold where the pellet is injected. Nonlinear MHD simulations of the pellet ELM triggering show destabilization of high-n ballooning modes by such a local pressure perturbation. A review of the recent pellet ELM triggering results from ASDEX Upgrade (AUG), DIII-D, and JET reveals that a number of uncertainties about this ELM mitigation technique still remain. These include the heat flux impact pattern on the divertor and wall from pellet triggered and natural ELMs, the necessary pellet size and injection location to reliably trigger ELMs, and the level of fueling to be expected from ELM triggering pellets and synergy with larger fueling pellets. The implications of these issues for pellet ELM mitigation in ITER and its impact on the PFCs are presented along with the design features of the pellet injection system for ITER.

  19. Mobile Biomass Pelletizing System

    SciTech Connect

    Thomas Mason

    2009-04-16

    This grant project examines multiple aspects of the pelletizing process to determine the feasibility of pelletizing biomass using a mobile form factor system. These aspects are: the automatic adjustment of the die height in a rotary-style pellet mill, the construction of the die head to allow the use of ceramic materials for extreme wear, integrating a heat exchanger network into the entire process from drying to cooling, the use of superheated steam for adjusting the moisture content to optimum, the economics of using diesel power to operate the system; a break-even analysis of estimated fixed operating costs vs. tons per hour capacity. Initial development work has created a viable mechanical model. The overall analysis of this model suggests that pelletizing can be economically done using a mobile platform.

  20. Radation shielding pellets

    DOEpatents

    Coomes, Edmund P.; Luksic, Andrzej T.

    1988-12-06

    Radiation pellets having an outer shell, preferably, of Mo, W or depleted U nd an inner filling of lithium hydride wherein the outer shell material has a greater melting point than does the inner filling material.

  1. Pneumatic Pellet-Transporting System

    NASA Technical Reports Server (NTRS)

    Wood, George; Pugsley, Robert A.

    1992-01-01

    Pneumatic system transports food pellets to confined animals. Flow of air into venturi assembly entrains round pellets, drawing them from reservoir into venturi for transport by airflow. Pneumatic pellet-transporting system includes venturi assembly, which creates flow of air that draws pellets into system.

  2. Pneumatic Pellet-Transporting System

    NASA Technical Reports Server (NTRS)

    Wood, George; Pugsley, Robert A.

    1992-01-01

    Pneumatic system transports food pellets to confined animals. Flow of air into venturi assembly entrains round pellets, drawing them from reservoir into venturi for transport by airflow. Pneumatic pellet-transporting system includes venturi assembly, which creates flow of air that draws pellets into system.

  3. Field test of short-notice random inspections for inventory-change verification at a low-enriched-uranium fuel-fabrication plant: Preliminary summary

    SciTech Connect

    Fishbone, L.G. |; Moussalli, G.; Naegele, G.; Ikonomou, P.; Hosoya, M.; Scott, P.; Fager, J.; Sanders, C.; Colwell, D.; Joyner, C.J.

    1994-04-01

    An approach of short-notice random inspections (SNRIs) for inventory-change verification can enhance the effectiveness and efficiency of international safeguards at natural or low-enriched uranium (LEU) fuel fabrication plants. According to this approach, the plant operator declares the contents of nuclear material items before knowing if an inspection will occur to verify them. Additionally, items about which declarations are newly made should remain available for verification for an agreed time. This report details a six-month field test of the feasibility of such SNRIs which took place at the Westinghouse Electric Corporation Commercial Nuclear Fuel Division. Westinghouse personnel made daily declarations about both feed and product items, uranium hexafluoride cylinders and finished fuel assemblies, using a custom-designed computer ``mailbox``. Safeguards inspectors from the IAEA conducted eight SNRIs to verify these declarations. Items from both strata were verified during the SNRIs by means of nondestructive assay equipment. The field test demonstrated the feasibility and practicality of key elements of the SNRI approach for a large LEU fuel fabrication plant.

  4. The Asian Wood Pellet Markets

    Treesearch

    Joseph A. Roos; Allen Brackley

    2012-01-01

    This study examines the three major wood pellet markets in Asia: China, Japan, and South Korea. In contrast to the United States, where most wood pellets are used for residential heating with pellet stoves, a majority of the wood pellets in Asia are used for co-firing at coal-fired power plants. Our analysis indicated that Japan is the largest importer of wood pellets...

  5. Overview of Recent Developments in Pellet Injection for ITER

    SciTech Connect

    Combs, Stephen Kirk; Baylor, Larry R; Meitner, Steven J; Caughman, John B; Rasmussen, David A; Maruyama, So

    2012-01-01

    Pellet injection is the primary fueling technique planned for core fueling of ITER burning plasmas. Also, the injection of relatively small pellets to purposely trigger rapid small edge localized modes (ELMs) has been proposed as a possible solution to the heat flux damage from larger natural ELMs likely to be an issue on the ITER divertor surfaces. The ITER pellet injection system is designed to inject pellets into the plasma through both inner and outer wall guide tubes. The inner wall guide tubes will provide high throughput pellet fueling while the outerwall guide tubes will be used primarily to trigger ELMs at a high frequency (>15 Hz). The pellet fueling rate ofeach injector is to be up to 120 Pa-m3/s, which will require the formation of solid D-T at a volumetric rate of ~1500 mm3/s. Two injectors are to be provided for ITER at the startup with a provision for up to six injectorsduring the D-T phase. The required throughput of each injector is greater than that of any injector built to date, and a novel twin-screw continuous extrusion system is being developed to meet the challenging design parameters. Status of the development activities will be presented, highlighting recent progress.

  6. Optical fiber inspection system

    DOEpatents

    Moore, Francis W.

    1987-01-01

    A remote optical inspection system including an inspection head. The inspection head has a passageway through which pellets or other objects are passed. A window is provided along the passageway through which light is beamed against the objects being inspected. A plurality of lens assemblies are arranged about the window so that reflected light can be gathered and transferred to a plurality of coherent optical fiber light guides. The light guides transfer the light images to a television or other image transducer which converts the optical images into a representative electronic signal. The electronic signal can then be displayed on a signal viewer such as a television monitor for inspection by a person. A staging means can be used to support the objects for viewing through the window. Routing means can be used to direct inspected objects into appropriate exit passages for accepted or rejected objects. The inspected objects are advantageously fed in a singular manner to the staging means and routing means. The inspection system is advantageously used in an enclosure when toxic or hazardous materials are being inspected.

  7. Optical fiber inspection system

    DOEpatents

    Moore, F.W.

    1985-04-05

    A remote optical inspection system including an inspection head. The inspection head has a passageway through which pellets or other objects are passed. A window is provided along the passageway through which light is beamed against the objects being inspected. A plurality of lens assemblies are arranged about the window so that reflected light can be gathered and transferred to a plurality of coherent optical fiber light guides. The light guides transfer the light images to a television or other image transducer which converts the optical images into a representative electronic signal. The electronic signal can then be displayed on a signal viewer such as a television monitor for inspection by a person. A staging means can be used to support the objects for viewing through the window. Routing means can be used to direct inspected objects into appropriate exit passages for accepted or rejected objects. The inspected objects are advantageously fed in a singular manner to the staging means and routing means. The inspection system is advantageously used in an enclosure when toxic or hazardous materials are being inspected. 10 figs.

  8. Fast breeder reactor fuel pins: Revision 1984

    SciTech Connect

    Not Available

    1984-01-01

    This standard establishes the requirements for fuel pins to be used in FBR fuel assemblies. Fuel pins consist of mixed uranium-plutonium oxide fuel pellets clad with Type 316 stainless steel or other purchaser specified alloy steel.

  9. Tritium pellet injector for the Tokamak Fusion Test Reactor

    SciTech Connect

    Gouge, M.J.; Baylor, L.R.; Combs, S.K.; Fisher, P.W.; Foust, C.R.; Milora, S.L.

    1992-01-01

    The tritium pellet injector (TPI) for the Tokamak Fusion Test Reactor (TFTR) will provide a tritium pellet fueling capability with pellet speeds in the 1- to 3-km/s range for the TFTR deuterium-tritium (D-T) plasma phase. An existing deuterium pellet injector (DPI) was modified at Oak Ridge National Laboratory (ORNL) to provide a four-shot, tritium-compatible, pipe-gun configuration with three upgraded single-stage pneumatic guns and a two-stage light gas gun driver. The TPI was designed for frozen pellets ranging in size from 3 to 4 mm in diameter in arbitrarily programmable firing sequences at tritium pellet speeds up to approximately 1.5 km/s for the three single-stage drivers and 2.5 to 3 km/s for the two-stage driver. Injector operation is controlled by a programmable logic controller (PLC). The new pipe-gun injector assembly was installed in the modified DPI guard vacuum box, and modifications were also made to the internals of the DPI vacuum injection line, including a new pellet diagnostics package. Assembly of these modified parts with existing DPI components was then completed and the TPI was tested at ORNL with deuterium pellets. Results of the testing program at ORNL are described. The TPI has been installed and operated on TFTR in support of the CY-92 deuterium plasma run period. In 1993, the tritium pellet injector will be retrofitted with a D-T fuel manifold and tritium gloveboxes and integrated into TFTR tritium processing systems to provide full tritium pellet capability.

  10. Tritium pellet injector for the Tokamak Fusion Test Reactor

    SciTech Connect

    Gouge, M.J.; Baylor, L.R.; Combs, S.K.; Fisher, P.W.; Foust, C.R.; Milora, S.L.

    1992-11-01

    The tritium pellet injector (TPI) for the Tokamak Fusion Test Reactor (TFTR) will provide a tritium pellet fueling capability with pellet speeds in the 1- to 3-km/s range for the TFTR deuterium-tritium (D-T) plasma phase. An existing deuterium pellet injector (DPI) was modified at Oak Ridge National Laboratory (ORNL) to provide a four-shot, tritium-compatible, pipe-gun configuration with three upgraded single-stage pneumatic guns and a two-stage light gas gun driver. The TPI was designed for frozen pellets ranging in size from 3 to 4 mm in diameter in arbitrarily programmable firing sequences at tritium pellet speeds up to approximately 1.5 km/s for the three single-stage drivers and 2.5 to 3 km/s for the two-stage driver. Injector operation is controlled by a programmable logic controller (PLC). The new pipe-gun injector assembly was installed in the modified DPI guard vacuum box, and modifications were also made to the internals of the DPI vacuum injection line, including a new pellet diagnostics package. Assembly of these modified parts with existing DPI components was then completed and the TPI was tested at ORNL with deuterium pellets. Results of the testing program at ORNL are described. The TPI has been installed and operated on TFTR in support of the CY-92 deuterium plasma run period. In 1993, the tritium pellet injector will be retrofitted with a D-T fuel manifold and tritium gloveboxes and integrated into TFTR tritium processing systems to provide full tritium pellet capability.

  11. Field test of short-notice random inspections for inventory-change verification at a low-enriched-uranium fuel-fabrication plant

    SciTech Connect

    Fishbone, L.G. |; Moussalli, G.; Naegele, G.

    1995-05-01

    An approach of short-notice random inspections (SNRIs) for inventory-change verification can enhance the effectiveness and efficiency of international safeguards at natural or low-enriched uranium (LEU) fuel fabrication plants. According to this approach, the plant operator declares the contents of nuclear material items before knowing if an inspection will occur to verify them. Additionally, items about which declarations are newly made should remain available for verification for an agreed time. Then a statistical inference can be made from verification results for items verified during SNRIs to the entire populations, i.e. the entire strata, even if inspectors were not present when many items were received or produced. A six-month field test of the feasibility of such SNRIs took place at the Westinghouse Electric Corporation Commercial Nuclear Fuel Division during 1993. Westinghouse personnel made daily declarations about both feed and product items, uranium hexafluoride cylinders and finished fuel assemblies, using a custom-designed computer ``mailbox``. Safeguards inspectors from the IAEA conducted eight SNRIs to verify these declarations. They arrived unannounced at the plant, in most cases immediately after travel from Canada, where the IAEA maintains a regional office. Items from both strata were verified during the SNRIs by meant of nondestructive assay equipment.

  12. Modeling pellet impact drilling process

    NASA Astrophysics Data System (ADS)

    Kovalyov, A. V.; Ryabchikov, S. Ya; Isaev, Ye D.; Ulyanova, O. S.

    2016-03-01

    The paper describes pellet impact drilling which could be used to increase the drilling speed and the rate of penetration when drilling hard rocks. Pellet impact drilling implies rock destruction by metal pellets with high kinetic energy in the immediate vicinity of the earth formation encountered. The pellets are circulated in the bottom hole by a high velocity fluid jet, which is the principle component of the ejector pellet impact drill bit. The experiments conducted has allowed modeling the process of pellet impact drilling, which creates the scientific and methodological basis for engineering design of drilling operations under different geo-technical conditions.

  13. Analytical chemistry methods for mixed oxide fuel, March 1985

    SciTech Connect

    Not Available

    1985-03-01

    This standard provides analytical chemistry methods for the analysis of materials used to produce mixed oxide fuel. These materials are ceramic fuel and insulator pellets and the plutonium and uranium oxides and nitrates used to fabricate these pellets.

  14. Modeling operation mode of pellet boilers for residential heating

    NASA Astrophysics Data System (ADS)

    Petrocelli, D.; Lezzi, A. M.

    2014-11-01

    In recent years the consumption of wood pellets as energy source for residential heating lias increased, not only as fuel for stoves, but also for small-scale residential boilers that, produce hot water used for both space heating and domestic hot water. Reduction of fuel consumption and pollutant emissions (CO, dust., HC) is an obvious target of wood pellet boiler manufacturers, however they are also quite interested in producing low- maintenance appliances. The need of frequent maintenance turns in higher operating costs and inconvenience for the user, and in lower boiler efficiency and higher emissions also. The aim of this paper is to present a theoretical model able to simulate the dynamic behavior of a pellet boiler. The model takes into account many features of real pellet boilers. Furthermore, with this model, it is possible to pay more attention to the influence of the boiler control strategy. Control strategy evaluation is based not only on pellet consumption and on total emissions, but also on critical operating conditions such as start-up and stop or prolonged operation at substantially reduced power level. Results are obtained for a residential heating system based on a wood pellet boiler coupled with a thermal energy storage. Results obtained so far show a weak dependence of performance in terms of fuel consumption and total emissions on control strategy, however some control strategies present some critical issues regarding maintenance frequency.

  15. Technique for controlling shrinkage distortion in cold-pressed annular pellets

    DOEpatents

    Johnson, R.G.R.; Burke, T.J.

    1982-06-28

    A process and apparatus are described for the production of annular fuel pellets comprising locating particulate fuel material in a compaction chamber having side walls, a moveable punch located opposite a fixed member and a frustoconical element having a taper of between about 0.010 to 0.015 inches/inch located in about the center of the chamber. The punch is moved toward the fixed surface to compact the particulate material. The compacted pellet is fired to produce sintered pellets having substantially straight inner side walls essentially parallel to the pellet axis.

  16. Pelletizing/reslurrying as a means of distributing and firing clean coal

    SciTech Connect

    Conkle, H.N.

    1992-06-09

    Work in this quarter focused on completing (1) the final batch of pilot-scale disk pellets, (2) storage, handling, and transportation evaluation, (3) pellet reslurrying and atomization studies, and (4) cost estimation for pellet and slurry production. Disk pelletization of Elkhorn coal was completed this quarter. Pellets were approximately 1/2- to 3/4-in. in diameter. Pellets, after thermal curing were strong and durable and exceeded the pellet acceptance criteria. Storage and handling tests indicate a strong, durable pellet can be prepared from all coals, and these pellets (with the appropriate binder) can withstand outdoor, exposed storage for at least 4 weeks. Pellets in unexposed storage show no deterioration in pellet properties. Real and simulated transportation tests indicate truck transportation should generate less than 5 percent fines during transport. Continuous reslurrying testing and subsequent atomization evaluation were performed this quarter in association with University of Alabama and Jim Walter Resources. Four different slurries of approximately 55-percent-solids with viscosities below 500 cP (at 100 sec{sup {minus}1}) were prepared. Both continuous pellet-to-slurry production and atomization testing was successfully demonstrated. Finally, an in depth evaluation of the cost to prepare pellets, transport, handle, store, and convert the pellet into Coal Water Fuel (CWF) slurries was completed. Cost of the pellet-CWF option are compared with the cost to directly convert clean coal filter cake into slurry and transport, handle and store it at the user site. Findings indicate that in many circumstances, the pellet-CWF option would be the preferred choice. The decision depends on the plant size and transportation distance, and to a lesser degree on the pelletization technique and the coal selected.

  17. Owl Pellet Paleontology

    ERIC Educational Resources Information Center

    McAlpine, Lisa K.

    2013-01-01

    In this activity for the beginning of a high school Biology 1 evolution unit, students are challenged to reconstruct organisms found in an owl pellet as a model for fossil reconstruction. They work in groups to develop hypotheses about what animal they have found, what environment it inhabited, and what niche it filled. At the end of the activity,…

  18. Owl Pellet Paleontology

    ERIC Educational Resources Information Center

    McAlpine, Lisa K.

    2013-01-01

    In this activity for the beginning of a high school Biology 1 evolution unit, students are challenged to reconstruct organisms found in an owl pellet as a model for fossil reconstruction. They work in groups to develop hypotheses about what animal they have found, what environment it inhabited, and what niche it filled. At the end of the activity,…

  19. Fabrication of micro-cell UO2-Mo pellet with enhanced thermal conductivity

    NASA Astrophysics Data System (ADS)

    Kim, Dong-Joo; Rhee, Young Woo; Kim, Jong Hun; Kim, Keon Sik; Oh, Jang Soo; Yang, Jae Ho; Koo, Yang-Hyun; Song, Kun-Woo

    2015-07-01

    As one of accident tolerant fuel pellets which should have features of good thermal conductivity and high fission product retention, a micro-cell UO2-Mo pellet has been studied in the aspect of fabrication and thermal property. It was intended to develop the compatible process with conventional UO2 pellet fabrication process. The effects of processing parameters such as the size and density of UO2 granule and the size of Mo powder have been studied to produce sound and dense pellet with completely connected uniform Mo cell-walls. The micro-cell UO2-Mo pellet consists of many Mo micro-cells and UO2 in them. The thermal conductivity of the micro-cell UO2-Mo pellet was measured and compared to those of the UO2 pellet and the UO2-Mo pellet with dispersed form of Mo particles. The thermal conductivity of the micro-cell UO2-Mo pellet was much enhanced and was found to be influenced by the Mo volumetric fraction and pellet integrity. A continuous Mo micro-cell works as a heat conducting channel in the pellet, greatly enhancing the thermal conductivity of the micro cell UO2-Mo pellet.

  20. Safety assessment of plutonium mixed oxide fuel irradiated up to 37.7 GW day tonne-1

    NASA Astrophysics Data System (ADS)

    Somers, J.; Papaioannou, D.; McGinley, J.; Sommer, D.

    2013-06-01

    In this irradiation test, the safety performance of (Th,Pu)O2 fuel was evaluated. The fuel pellets were synthesised from powders prepared using a sol gel method to give a product exhibiting an atomically homogeneous distribution of the elements. The fuel pellets, of conventional pressurised water reactor (PWR) dimensions, were encapsulated in zircaloy cladding, and irradiated during four reactor cycles, reaching a burnup of 37.7 GW day tonne-1 in the KWO pressurised water reactor at Obrigheim, Germany. The irradiation test was performed under representative conditions. Intermediate inspection of the fuel pin during reactor outages revealed a cladding creep down within the bounds observed for UO2 fuels under similar conditions. Hydriding of the cladding was found predominantly on the outer liner of the duplex cladding. Fission gas analysis revealed a release of about 0.5%, which is somewhat lower than U-MOX fuels at the same burnup, but the latter were operated at higher linear heating rate. The Xe/Kr ratio of 11 is much lower than (U,Pu)O2 fuel (typically 16), indicating significant 233U generation and fissioning thereof during the irradiation experiment. Examination of the microstructure indicates that the pellet - cladding gap is almost closed. The grain size remained similar to the fresh fuel (4 μm) and no intragranular porosity was observed.

  1. Evaluation of ANF fuel failures in oyster creek

    SciTech Connect

    Howe, T.M.; Van Swam, L.F.; Piascik, T.G.; Spence, P.A.

    1988-01-01

    During the refueling outrage following cycle-10 operations of Oyster Creek nuclear generating station, fuel sipping identified 47 failed Advance Nuclear Fuels (ANF) fuel assemblies. The failed fuel was an unpressurized 8 x 8 design manufactured by ANF prior to 1980. Subsequent inspection of 46 of these 47 assemblies with the ANF ULTRATEST ultrasonic testing system indicated 104 either failed of suspect fuel rods in 44 assemblies. Two of the assemblies were identified as being sound. Selected fuel rods were removed from three of the assemblies and inspected both visually and with an eddycurrent coil. An evaluation has been performed to determine the cause of the failures. The failures were primarily the result of pellet/cladding interaction (PCI). Detailed analyses of several of the failed fuel rods were performed with ANF's fuel rod modeling code RAMPX2. RAMPX2 includes several state-of-the-art models, including a model describing the formation of fission product deposits called coins on the inside surface of the cladding, a model that accounts for axial PCI, and a trapped fuel stack model. The analyses provided an explanation for the failures.

  2. Pellet imaging techniques on ASDEX

    SciTech Connect

    Wurden, G.A. ); Buechl, K.; Hofmann, J.; Lang, R.; Loch, R.; Rudyj, A.; Sandmann, W. )

    1990-01-01

    As part of a USDOE/ASDEX collaboration, a detailed examination of pellet ablation in ASDEX with a variety of diagnostics has allowed a better understanding of a number of features of hydrogen ice pellet ablation in a plasma. In particular, fast gated photos with an intensified Xybion CCD video camera allow in-situ velocity measurements of the pellet as it penetrates the plasma. With time resolution of typically 100 nanoseconds and exposures every 50 microseconds, the evolution of each pellet in a multi-pellet ASDEX tokamak plasma discharge can be followed. When the pellet cloud track has striations, the light intensity profile through the cloud is hollow (dark near the pellet), whereas at the beginning or near the end of the pellet trajectory the track is typically smooth (without striations) and has a gaussian-peaked light emission profile. New, single pellet Stark broadened D{sub {alpha}}D{sub {beta}}, and D{sub {gamma}} spectra, obtained with a tangentially viewing scanning mirror/spectrometer with Reticon array readout, are consistent with cloud densities of 2 {times} 10{sup 17}cm{sup {minus}3} or higher in the regions of strongest light emission. A spatially resolved array of D{sub {alpha}} detectors shows that the light variations during the pellet ablation are not caused solely by a modulation of the incoming energy flux as the pellet crosses rational q-surfaces, but instead are a result of a dynamic, non-stationary, ablation process. 20 refs., 4 figs.

  3. Development of a Tritium Extruder for ITER Pellet Injection

    SciTech Connect

    M.J. Gouge; P.W. Fisher

    1998-09-01

    As part of the International Thermonuclear Experimental Reactor (ITER) plasma fueling development program, Oak Ridge National Laboratory (ORNL) has fabricated a pellet injection system to test the mechanical and thermal properties of extruded tritium. Hydrogenic pellets will be used in ITER to sustain the fusion power in the plasma core and may be crucial in reducing first-wall tritium inventories by a process of "isotopic fueling" in which tritium-rich pellets fuel the burning plasma core and deuterium gas fuels the edge. This repeating single-stage pneumatic pellet injector, called the Tritium-Proof-of-Principle Phase II (TPOP-II) Pellet Injector, has a piston-driven mechanical extruder and is designed to extrude and accelerate hydrogenic pellets sized for the ITER device. The TPOP-II program has the following development goals: evaluate the feasibility of extruding tritium and deuterium-tritium (D-T) mixtures for use in future pellet injection systems; determine the mechanical and thermal properties of tritium and D-T extrusions; integrate, test, and evaluate the extruder in a repeating, single-stage light gas gun that is sized for the ITER application (pellet diameter -7 to 8 mm); evaluate options for recycling propellant and extruder exhaust gas; and evaluate operability and reliability of ITER prototypical fueling systems in an environment of significant tritium inventory that requires secondary and room containment systems. In tests with deuterium feed at ORNL, up to 13 pellets per extrusion have been extruded at rates up to 1 Hz and accelerated to speeds of 1.0 to 1.1 km/s, using hydrogen propellant gas at a supply pressure of 65 bar. Initially, deuterium pellets 7.5 mm in diameter and 11 mm in length were produced-the largest cryogenic pellets produced by the fusion program to date. These pellets represent about a 10% density perturbation to ITER. Subsequently, the extruder nozzle was modified to produce pellets that are almost 7.5-mm right circular

  4. End-of-life nondestructive examination of Light Water Breeder Reactor fuel rods (LWBR Development Program)

    SciTech Connect

    Gorscak, D.A.; Campbell, W.R.; Clayton, J.C.

    1987-10-01

    In-bundle and out-of-bundle (single rod) nondestructive examinations of Light Water Breeder Reactor fuel rods were performed. In-bundle examinations included visual examination and measurement of rod bow, rod-to-rod gaps, and rod removal forces. Out-of-bundle examinations included rod visuals and measurement of fuel rod length, diameter and ovality, cladding oxide and crud thickness, support grid induced cladding wear mark depth and volume, and fuel rod free hanging bow. The out-of-bundle examination also included ultrasonic inspection for cladding defects, neutron radiography for pellet integrity and plenum gap measurements, and gamma scans for instack axial gap screening and binary fuel stack length measurements. The measurements confirmed design predictions of fuel rod performance and provided evidence of excellent fuel rod performance for operation of Light Water Breeder Reactor to 29,047 effective full power hours (EFPH).

  5. Nondestructive inspection of General Purpose Heat Source (GPHS) girth welds

    SciTech Connect

    Reimus, M.A.H.; George, T.G.; Lynch, C.

    1998-12-31

    The General-Purpose Heat Source (GPHS) provides power for space missions by transmitting the heat of {sup 238}Pu decay to an array of thermoelectric elements. The GPHS is fabricated using iridium capsules, TIG welded, to contain the {sup 238}PuO{sub 2} fuel pellet. GPHS capsules will be utilized in the upcoming Cassini mission to explore Saturn and its moons. The physical integrity of the girth weld is important to mission safety and performance. Since experience in the past had revealed a potential for initiation of small cracks in the girth weld overlap zone, a nondestructive inspection of the capsule weld is required. A ultrasonic method was used to inspect the welds of capsules fabricated for the Galileo mission. The instrument, transducer, and method used were state of the art at the time (early 1980s). The ultrasonic instrumentation and methods used to inspect the Cassini GPHSs was significantly upgraded from those used for the Galileo mission. GPHSs that had ultrasonic reflectors that exceeded the reject specification level were subsequently inspected with radiography to provide additional engineering data used to accept/reject the heat source. This paper describes the Galileo-era ultrasonic instrumentation and methods and the subsequent upgrades made to support testing of Cassini GPHSs. Also discussed is the data obtained from radiographic examination and correlation to ultrasonic examination results.

  6. An Analysis of Wood Pellets For Export: A Case Study of Sweden as an Importer

    Treesearch

    P.B. Aruna; Jan G. Laarman; Philip A. Araman; Frederick Cubbage

    1997-01-01

    North America is a major producer of wood pellets, and the principal market for them is domestic residential wood heating. To date, the export market for wood pellets is small. On the other hand , several developments are occurring that may be increasing the foreign demand for biomass fuels. A few North American companies are considering Sweden as a potential export...

  7. Pellet interaction with runaway electrons

    SciTech Connect

    James, A. N.; Hollmann, E. M.; Yu, J.H.; Austin, M. E.; Commaux, Nicolas JC; Evans, T.E.; Humphrey, D. A.; Jernigan, T. C.; Parks, P. B.; Putvinski, S.; Strait, E. J.; Tynan, G. R.; Wesley, J. C.

    2011-01-01

    We describe results from recent experiments studying interaction of solid polystyrene pellets with a runaway electron current channel generated after cryogenic argon pellet rapid shutdown of DIII-D. Fast camera imaging shows the pellet trajectory and continuum emission from the subsequent explosion, with geometric calibration providing detailed explosion analysis and runaway energy. Electron cyclotron emission also occurs, associated with knock-on electrons broken free from the pellet by RE which then accelerate and runaway, and also with a short lived hot plasma blown off the pellet surface. In addition, we compare heating and explosion times from observations and a model of pellet heating and breakdown by runaway interaction. (C) 2011 Elsevier B.V. All rights reserved

  8. FUEL ELEMENT FOR NUCLEAR REACTORS

    DOEpatents

    Bassett, C.H.

    1961-11-21

    A fuel element is designed which is particularly adapted for reactors of high power density used to generate steam for the production of electricity. The fuel element consists of inner and outer concentric tubes forming an annular chamber within which is contained fissionable fuel pellet segments, wedge members interposed between the fuel segments, and a spring which, acting with wedge members, urges said fuel pellets radially into contact against the inner surface of the outer tube. The wedge members may be a fertile material convertible into fissionable fuel material by absorbing neutrons emitted from the fissionable fuel pellet segments. The costly grinding of cylindrical fuel pellets to close tolerances for snug engagement is reduced because the need to finish the exact size is eliminated. (AEC)

  9. Pellet feed system

    SciTech Connect

    Whitfield, O.J.

    1990-08-07

    This patent describes an improvement in a stoker assembly for a solid particulate fuel burning stove. The stove including a combustion chamber, at least one remote substantially airtight fuel storage bin and a conveyor system for transporting fuel from the fuel storage bin to the combustion chamber. The improvement comprises: a conduit separate from the conveyor system, the conduit communicating between the combustion chamber and the fuel storage bin for minimizing the pressure difference along the conveyor system, such that oxygen supplied to the conveyor system is insufficient to support combustion of fuel in the conveyor system, the conduit being positioned above the conveyor system, the conveyor system including an auger and a casing for the auger.

  10. The properties of pellets from mixing bamboo and rice straw

    Treesearch

    Zhijia Liu; Xing' e Liu; Benhua Fei; Zehui Jiang; Zhiyong Cai; Yan Yu

    2013-01-01

    Rice straw pellets are the main type of biomass solid fuel and have great potential as a bioenergy resource of the future in China. But it also showed important problems because of its high content of ashes and its low gross calorific value, reducing the possibility to be used in domestic heating. It was certified that mixing different types of biomass materials was...

  11. Rapid Inward Impurity Transport during Impurity Pellet Injection on the DIII-D Tokamak

    SciTech Connect

    Evans, T.E.; Hyatt, A.W.; Lee, R.L.; Kellman, A.G.; Parks, P.B.; Stockdale, R.; Taylor, P.L.; Whyte, D.G.; Jernigan, T.C.

    1998-11-01

    Neon killer pellets are injected into the DIII-D tokamak plasma in order to radiatively quench the plasma{close_quote}s stored energy and mitigate disruption effects. Inward radial transport on the time scale of the pellet ablation ({le}1 ms) results in central deposition of the neon inside the ablation penetration radius of the pellet, causing effective radiative energy dissipation. This result is in contrast to the radially outward deposition measured for fueling (hydrogenic) pellets. The observed magnitudes of magnetic fluctuations ({delta}B/B{approximately}0.2{percent}) are shown to be capable of causing the radial transport. {copyright} {ital 1998} {ital The American Physical Society }

  12. Pelletization of biomass waste with potato pulp content

    NASA Astrophysics Data System (ADS)

    Obidziński, Sławomir

    2014-03-01

    This paper presents the results of a research on the influence of potato pulp content in a mixture with oat bran on the power demand of the pelletization process and on the quality of the produced pellets, in the context of use thereof as a heating fuel. The tests of the densification of the pulp and bran mixture were carried out on a work stand whose main element was a P-300 pellet mill with the `flat matrix-densification rolls' system. 24 h after the pellets left the working system, their kinetic durability was established with the use of a Holmen tester. The research results obtained in this way allowed concluding that increasing the potato pulp content in a mixture with oat bran from 15 to 20% caused a reduction of the power demand of the pellet mill. It was also established that as the pulp content in a mixture with oat bran increases from 15 to 25%, the value of the kinetic durability of the pellets determined using Holmen and Pfost methods decreases.

  13. Results of hydrogen pellet injection into ISX-B

    SciTech Connect

    Milora, S.L.; Foster, C.A.; Thomas, C.E.

    1980-09-01

    High speed pellet fueling experiments have been performed on the ISX-B device in a new regime characterized by large global density rise in both ohmic and neutral beam heated discharges. Hydrogen pellets of 1 mm in diameter were injected in the plasma midplane at velocities exceeding 1 km/s. In low temperature ohmic discharges, pellets penetrate beyond the magnetic axis, and in such cases a sharp decrease in ablation is observed as the pellet passes the plasma center. Density increases of approx. 300% have been observed without degrading plasma stability or confinement. Energy confinement time increases in agreement with the empirical scaling tau/sub E/ approx. n/sub e/ and central ion temperature increases as a result of improved ion-electron coupling. Laser-Thomson scattering and radiometer measurements indicate that the pellet interaction with the plasma is adiabatic. Penetration to r/a approx. 0.15 is optimal, in which case large amplitude sawtooth oscillations are observed and the density remains elevated. Gross plasma stability is dependent roughly on the amount of pellet penetration and can be correlated with the expected temporal evolution of the current density profile.

  14. Development and validation of a railgun hydrogen pellet injector model

    SciTech Connect

    King, T.L.; Zhang, J.; Kim, K.

    1995-12-31

    A railgun hydrogen pellet injector model is presented and its predictions are compared with the experimental data. High-speed hydrogenic ice injection is the dominant refueling method for magnetically confined plasmas used in controlled thermonuclear fusion research. As experimental devices approach the scale of power-producing fusion reactors, the fueling requirements become increasingly more difficult to meet since, due to the large size and the high electron densities and temperatures of the plasma, hypervelocity pellets of a substantial size will need to be injected into the plasma continuously and at high repetition rates. Advanced technologies, such as the railgun pellet injector, are being developed to address this demand. Despite the apparent potential of electromagnetic launchers to produce hypervelocity projectiles, physical effects that were neither anticipated nor well understood have made it difficult to realize this potential. Therefore, it is essential to understand not only the theory behind railgun operation, but the primary loss mechanisms, as well. Analytic tools have been used by many researchers to design and optimize railguns and analyze their performance. This has led to a greater understanding of railgun behavior and opened the door for further improvement. A railgun hydrogen pellet injector model has been developed. The model is based upon a pellet equation of motion that accounts for the dominant loss mechanisms, inertial and viscous drag. The model has been validated using railgun pellet injectors developed by the Fusion Technology Research Laboratory at the University of Illinois at Urbana-Champaign.

  15. Pellet bed reactor for nuclear propelled vehicles: Part 1: Reactor technology

    NASA Technical Reports Server (NTRS)

    El-Genk, Mohamed S.

    1991-01-01

    The pellet bed reactor (PBR) for nuclear propelled vehicles is briefly discussed. Much of the information is given in viewgraph form. Viewgraphs include information on the layout for a Mars mission using a PBR nuclear thermal rocket, the rocket reactor layout, the fuel pellet design, materials compatibility, fuel microspheres, microsphere coating, melting points in quasibinary systems, stress analysis of microspheres, safety features, and advantages of the PBR concept.

  16. Advanced maintenance, inspection & repair technology for nuclear power plants

    SciTech Connect

    Hinton, B.M.

    1994-12-31

    Maintenance, inspection, and repair technology for nuclear power plants is outlined. The following topics are discussed: technology for reactor systems, reactor refueling bridge, fuel inspection system, fuel shuffling software, fuel reconstitution, CEA/RCCA/CRA inspection, vessel inspection capabilities, CRDM inspection and repair, reactor internals inspection and repair, stud tensioning system, stud/nut cleaning system, EDM machining technology, MI Cable systems, core exit T/C nozzle assemblies, technology for steam generators, genesis manipulator systems, ECT, UT penetrant inspections, steam generator repair and cleaning systems, technology for balance of plant, heat exchangers, piping and weld inspections, and turbogenerators.

  17. Owl Pellets and Crisis Management.

    ERIC Educational Resources Information Center

    Anderson, Tom

    2002-01-01

    Describes a press conference that was used as a "teachable moment" when owl pellets being used for instructional purposes were found to be contaminated with Salmonella. The incident highlighted the need for safe handling of owl pellets, having a crisis management plan, and the importance of conveying accurate information to concerned parents.…

  18. Owl Pellets and Crisis Management.

    ERIC Educational Resources Information Center

    Anderson, Tom

    2002-01-01

    Describes a press conference that was used as a "teachable moment" when owl pellets being used for instructional purposes were found to be contaminated with Salmonella. The incident highlighted the need for safe handling of owl pellets, having a crisis management plan, and the importance of conveying accurate information to concerned parents.…

  19. Initial NSTX Lithium Pellet Injection

    NASA Astrophysics Data System (ADS)

    Kugel, H. W.; Bell, M.; Bell, R.; Biewer, T.; Gates, D.; Jardin, S.; Kaita, R.; Leblanc, B.; Paul, S.; Samtaney, R.; Skinner, C. H.; Raman, R.; Bush, C.; Maingi, R.; Soukhanovskii, V.; Nishino, N.; Lee, K. C.; Stutman, D.

    2004-11-01

    A cartridge style Lithium Pellet Injector was installed on NSTX for midplane radial injection. Deuterium gas was used to propel a Li pellet-bearing cartridge down a barrel to a cartridge stop, and the pellet continued into the NSTX plasma at about 150 m/s. 16 lithium pellets, about 2 mg each were injected into LSN and DND, NBI-heated, H-mode plasmas, and into L-mode LSN Ohmic plasmas, and were observed with a Li I filtered Plasma-TV. Li pellets injected into NBI-heated LSN and DND plasmas appeared to ablate in the outer boundary. The pellets injected into OH plasmas exhibited good penetration to the HFS region. Lastly, a NBI preheat was added prior to pellet arrival, and the penetration depth was found to be very sensitive to the NBI turn-off time relative to pellet arrival. As this work progressed, Li luminosity started to be observed from the very initiation of discharges, due to depositions from preceding discharges. Initial modeling results will be presented.

  20. Operation and reliability of a pneumatic hydrogen pellet injection system on the Joint European Torus

    SciTech Connect

    Combs, S.K.; Jernigan, T.C.; Baylor, L.R.; Milora, S.L.; Foust, C.R.; Kupschus, P.; Gadeberg, M.; Bailey, W.; Commission of the European Communities, Abingdon . JET Joint Undertaking)

    1989-01-01

    A pneumatic-based, hydrogen isotope pellet injector that was developed at the Oak Ridge National Laboratory for the plasma fueling application on the Joint European Torus (JET) was described at the last Symposium on Fusion Engineering (1987). The injector was installed on JET during 1987 and has since been used in plasma fueling experiments. The injector consists of three independent machine-gun-like mechanisms (nominal pellet sizes of 2.7, 4.0, and 6.0 mm in diameter), and it features repetitive operation (1-5 Hz) for quasi-steady-state conditions (>10 s). An extensive set of injector diagnostics permits evaluation of parameters for each pellet shot, including speed, mass, and integrity. Pellet speeds can be varied but typically range from 1.0 to 1.5 km/s. Over 5000 pellets have been fired with the equipment at JET, including about 2000 pellets shot for plasma fueling experiments. In recent experiments, the system performance has been outstanding, including excellent reproducibility in pellet speed and mass and a reliability of >98% in delivery of pellets to the plasma. 7 refs., 5 figs.

  1. QUALITY OF WOOD PELLETS PRODUCED IN BRITISH COLUMBIA FOR EXPORT

    SciTech Connect

    Tumuluru, J.S.; Sokhansanj, Shahabaddine; Lim, C. Jim; Bi, X.T.; Lau, A.K.; Melin, Staffan; Oveisi, E.; Sowlati, T.

    2010-11-01

    Wood pellet production and its use for heat and power production are increasing worldwide. The quality of export pellets has to consistently meet certain specifications as stipulated by the larger buyers, such as power utilities or as specified by the standards used for the non-industrial bag market. No specific data is available regarding the quality of export pellets to Europe. To develop a set of baseline data, wood pellets were sampled at an export terminal in Vancouver, British Columbia, Canada. The sampling period was 18 months in 2007-2008 when pellets were transferred from storage bins to the ocean vessels. The sampling frequency was once every 1.5 to 2 months for a total of 9 loading/shipping events. The physical properties of the wood pellets measured were moisture content in the range of 3.5% to 6.5%, bulk density from 728 to 808 kg/m3, durability from 97% to 99%, fines content from 0.03% to 0.87%, calorific value as is from 17 to almost 18 MJ/kg, and ash content from 0.26% to 0.93%.The diameter and length were in the range of 6.4 to 6.5 mm and 14.0 to 19.0 mm, respectively. All of these values met the published non-industrial European grades (CEN) and the grades specified by the Pellet Fuel Institute for the United States for the bag market. The measured values for wood pellet properties were consistent except the ash content values decreased over the test period.

  2. Quality of Wood Pellets Produced in British Columbia for Export

    SciTech Connect

    J. S. Tumuluru; S. Sokhansanj; C. J. Lim; T. Bi; A. Lau; S. Melin; T. Sowlati; E. Oveisi

    2010-11-01

    Wood pellet production and its use for heat and power production are increasing worldwide. The quality of export pellets has to consistently meet certain specifications as stipulated by the larger buyers, such as power utilities or as specified by the standards used for the non-industrial bag market. No specific data is available regarding the quality of export pellets to Europe. To develop a set of baseline data, wood pellets were sampled at an export terminal in Vancouver, British Columbia, Canada. The sampling period was 18 months in 2007-2008 when pellets were transferred from storage bins to the ocean vessels. The sampling frequency was once every 1.5 to 2 months for a total of 9 loading/shipping events. The physical properties of the wood pellets measured were moisture content in the range of 3.5% to 6.5%, bulk density from 728 to 808 kg/m3, durability from 97% to 99%, fines content from 0.03% to 0.87%, calorific value as is from 17 to almost 18 MJ/kg, and ash content from 0.26% to 0.93%.The diameter and length were in the range of 6.4 to 6.5 mm and 14.0 to 19.0 mm, respectively. All of these values met the published non-industrial European grades (CEN) and the grades specified by the Pellet Fuel Institute for the United States for the bag market. The measured values for wood pellet properties were consistent except the ash content values decreased over the test period.

  3. Modifying ability of titanium-based pelleted master alloys

    NASA Astrophysics Data System (ADS)

    Bazhin, V. Yu.; Savchenkov, S. A.; Kosov, Ya. I.

    2017-05-01

    The problem of enhancing the quality of pressed titanium master alloys is discussed to increase the rate and degree of dissolution of their components and to ensure the formation of a fine-grained structure in aluminum alloys. A technology of producing a pelleted titanium master alloy for effective correction of the chemical composition of an aluminum alloy in casting is developed and tested. Incoming inspection of the component composition and the flux distribution in the volume of pressed pellets of various manufacturers is performed. The rate of dissolution of pressed powder master alloys in the aluminum melt is studied, and their modifying ability is estimated after studying the microstructures of cast blanks. Molasses is used as a binder in a pelleted master alloy. As a result, we achieved a uniform flux distribution over the pellet volume and the formation of uniform pores after annealing as compared pelleted master alloys of other manufacturers. The fabricated alloying briquettes have higher strength characteristics and their dissolution rate in the aluminum melt is higher than those of analogs by 15-20%.

  4. /sup 238/Pu fuel form processes. Bimonthly report, November-December 1979

    SciTech Connect

    Folger, R. L.

    1980-11-01

    Progress in the Savannah River Laboratory's /sup 238/Pu Fuel Form Program is summarized. Full-scale fabrication tests continued in the Plutonium Experimental Facility (PEF) with the successful fabrication of seven additional GPHS pellets. Three pellets (GPHS Pellets 14, 15, and 16) were fabricated at off-centerline conditions to help define process limits for production of GPHS fuel pellets in the Plutonium Fuel Fabrication (PuFF) Facility. Two additional limit-test pellets (GPHS Pellets 12 and 13) previously hot pressed underwent final heat treatment. Two pellets (GPHS Pellets 17 and 18) were fabricated at centerline conditions as part of the effort to have Savannah River Laboratory (SRL) GPHS pellets impact tested at LASL. All seven pellets remained integral and demonstrated excellent dimensional stability during final heat treatment. However, the quality of those pellets fabricated at centerline conditions was superior to those that were fabricated as part of the limit tests.

  5. Monitoring of carbon monoxide in residences with bulk wood pellet storage in the Northeast United States.

    PubMed

    Rossner, Alan; Jordan, Carolyn E; Wake, Cameron; Soto-Garcia, Lydia

    2017-10-01

    The interest in biomass fuel is continuing to expand globally and in the northeastern United States as wood pellets are becoming a primary source of fuel for residential and small commercial systems. Wood pellets for boilers are often stored in basement storage rooms or large bag-type containers. Due to the enclosed nature of these storage areas, the atmosphere may exhibit increased levels of carbon monoxide. Serious accidents in Europe have been reported over the last decade in which high concentrations of carbon monoxide (CO) have been found in or near bulk pellet storage containers. The aim of this study was to characterize the CO concentrations in areas with indoor storage of bulk wood pellets. Data was obtained over approximately 7 months (December 2013 to June 2014) at 25 sites in New Hampshire and Massachusetts: 16 homes using wood pellet boilers with indoor pellet storage containers greater than or equal to 3 ton capacity; 4 homes with wood pellet heating systems with outdoor pellet storage; 4 homes using other heating fuels; and a university laboratory site. CO monitors were set up in homes to collect concentrations of CO in the immediate vicinity of wood pellet storage containers, and data were then compared to those of homes using fossil fuel systems. The homes monitored in this study provided a diverse set of housing stock spanning two and a half centuries of construction, with homes built from 1774 to 2013, representing a range of air exchange rates. The CO concentration data from each home was averaged hourly and then compared to a threshold of 9 ppm. While concentrations of CO were generally low for the homes studied, the need to properly design storage locations for pellets is and will remain a necessary component of wood pellet heating systems to minimize the risk of CO exposure. This paper is an assessment of carbon monoxide (CO) exposure from bulk wood pellet storage in homes in New Hampshire and Massachusetts. Understanding the CO concentrations

  6. Automated fabrication, characterization and transport of ICF pellets. Final report, March 1, 1979-October 31, 1980

    SciTech Connect

    Clifford, D W; Boyd, B A; Lilienkamp, R H

    1980-12-01

    The near-term objectives of the contract were threefold: (1) evaluate techniques for the production of frozen hydrogen microspheres and demonstrate concepts for coating them; (2) develop and demonstrate an optical characterization system which could lead to automated pellet inspection; and (3) develop and demonstrate a preliminary electrostatic pellet transport control system. This report describes the equipment assembled for these experiments and the results obtained.

  7. Compliance characteristics of cracked UO/sub 2/ pellets. [PWR; BWR

    SciTech Connect

    Williford, R.E.; Mohr, C.L.; Lanning, D.D.

    1981-01-01

    The thermally induced cracking of UO/sub 2/ fuel pellets causes simultaneous reductions of the bulk (extrinsic) fuel thermal conductivity and elastic moduli to values significantly less than those for solid pellets. The magnitude of these bulk properly reductions was found to be primarily dependent on the amount of crack area in the transverse plane of the fuel. The model described herein uses a simple description of the crack geometry to couple the fuel rod thermal and mechanical behaviors by relating in-reactor data to Hooke's Law and a crack compliance model. Data from the NRC/PNL Halden experiment IFA-432 show that for a typical helium-filled BWR-design rod at 30 kW/m, the effective thermal conductivity and elastic moduli of the cracked fuel are 4/5 and 1/40 of that for solid pellets, respectively.

  8. Ultrasonic Inspection Of Thick Sections

    NASA Technical Reports Server (NTRS)

    Friant, C. L.; Djordjevic, B. B.; O'Keefe, C. V.; Ferrell, W.; Klutz, T.

    1993-01-01

    Ultrasonics used to inspect large, relatively thick vessels for hidden defects. Report based on experiments in through-the-thickness transmission of ultrasonic waves in both steel and filament-wound composite cases of solid-fuel rocket motors.

  9. Simulation of Pellet Ablation

    NASA Astrophysics Data System (ADS)

    Parks, P. B.; Ishizaki, Ryuichi

    2000-10-01

    In order to clarify the structure of the ablation flow, 2D simulation is carried out with a fluid code solving temporal evolution of MHD equations. The code includes electrostatic sheath effect at the cloud interface.(P.B. Parks et al.), Plasma Phys. Contr. Fusion 38, 571 (1996). An Eulerian cylindrical coordinate system (r,z) is used with z in a spherical pellet. The code uses the Cubic-Interpolated Psudoparticle (CIP) method(H. Takewaki and T. Yabe, J. Comput. Phys. 70), 355 (1987). that divides the fluid equations into non-advection and advection phases. The most essential element of the CIP method is in calculation of the advection phase. In this phase, a cubic interpolated spatial profile is shifted in space according to the total derivative equations, similarly to a particle scheme. Since the profile is interpolated by using the value and the spatial derivative value at each grid point, there is no numerical oscillation in space, that often appears in conventional spline interpolation. A free boundary condition is used in the code. The possibility of a stationary shock will also be shown in the presentation because the supersonic ablation flow across the magnetic field is impeded.

  10. Flexible Borescope For Inspecting Ducts

    NASA Technical Reports Server (NTRS)

    Shinozaki, Keith; Armstrong, Mike P.; Urquidi, Ron

    1995-01-01

    Borescope and associated equipment developed specifically for use in optical inspection of inside of flexible joints in rocket-engine fuel duct. Apparatus includes assembly, characterized as "mouse/canoe," at sensing end of 10-ft borescope cable. Borescope tip rides in mouse/canoe. The mouse/canoe made laterally compressible, to facilitate movement past constrictions and provides fixed distance from inspection point permitting accurate description in duct inspected.

  11. The design and performance of a twenty barrel hydrogen pellet injector for Alcator C-Mod

    SciTech Connect

    Urbahn, John A.

    1994-05-01

    A twenty barrel hydrogen pellet injector has been designed, built and tested both in the laboratory and on the Alcator C-Mod Tokamak at MIT. The injector functions by firing pellets of frozen hydrogen or deuterium deep into the plasma discharge for the purpose of fueling the plasma, modifying the density profile and increasing the global energy confinement time. The design goals of the injector are: (1) Operational flexibility, (2) High reliability, (3) Remote operation with minimal maintenance. These requirements have lead to a single stage, pipe gun design with twenty barrels. Pellets are formed by in- situ condensation of the fuel gas, thus avoiding moving parts at cryogenic temperatures. The injector is the first to dispense with the need for cryogenic fluids and instead uses a closed cycle refrigerator to cool the thermal system components. The twenty barrels of the injector produce pellets of four different size groups and allow for a high degree of flexibility in fueling experiments. Operation of the injector is under PLC control allowing for remote operation, interlocked safety features and automated pellet manufacturing. The injector has been extrusively tested and shown to produce pellets reliably with velocities up to 1400 m/sec. During the period from September to November of 1993, the injector was successfully used to fire pellets into over fifty plasma discharges. Experimental results include data on the pellet penetration into the plasma using an advanced pellet tracking diagnostic with improved time and spatial response. Data from the tracker indicates pellet penetrations were between 30 and 86 percent of the plasma minor radius.

  12. North America's wood pellet sector

    Treesearch

    Henry Spelter; Daniel Toth

    2009-01-01

    The North American wood pellet sector is profiled in this paper. A small pellet industry has existed since the 1930s, but its main growth occurred in the wake of the energy crisis in the 1970s. Its current spurt is even greater, growing from is set to reach 6.2 million in 2009. Most plants are small, relying on sawmill residues for fiber and thus are limited to 100,000...

  13. 46 CFR 148.325 - Wood chips; wood pellets; wood pulp pellets.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Wood chips; wood pellets; wood pulp pellets. 148.325... § 148.325 Wood chips; wood pellets; wood pulp pellets. (a) This part applies to wood chips and wood pulp... cargo hold. (b) No person may enter a cargo hold containing wood chips, wood pellets, or wood...

  14. 46 CFR 148.325 - Wood chips; wood pellets; wood pulp pellets.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Wood chips; wood pellets; wood pulp pellets. 148.325... § 148.325 Wood chips; wood pellets; wood pulp pellets. (a) This part applies to wood chips and wood pulp... cargo hold. (b) No person may enter a cargo hold containing wood chips, wood pellets, or wood...

  15. 46 CFR 148.325 - Wood chips; wood pellets; wood pulp pellets.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Wood chips; wood pellets; wood pulp pellets. 148.325... § 148.325 Wood chips; wood pellets; wood pulp pellets. (a) This part applies to wood chips and wood pulp... cargo hold. (b) No person may enter a cargo hold containing wood chips, wood pellets, or wood...

  16. 46 CFR 148.325 - Wood chips; wood pellets; wood pulp pellets.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Wood chips; wood pellets; wood pulp pellets. 148.325... § 148.325 Wood chips; wood pellets; wood pulp pellets. (a) This part applies to wood chips and wood pulp... cargo hold. (b) No person may enter a cargo hold containing wood chips, wood pellets, or wood...

  17. 46 CFR 148.04-21 - Coconut meal pellets (also known as copra pellets).

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Coconut meal pellets (also known as copra pellets). 148.04-21 Section 148.04-21 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) DANGEROUS... § 148.04-21 Coconut meal pellets (also known as copra pellets). (a) Coconut meal pellets; (1) Must...

  18. Interaction of Impurity (Li, Be, B and C) and Hydrogen Isotope Pellet Injection with Reactor-relevant Plasmas

    NASA Astrophysics Data System (ADS)

    Deng, Baiquan; J, P. Allain; Peng, Lilin; Wang, Xiaoyu; Chen, Zhi; Yan, Jiancheng

    2005-02-01

    Based on the two-dimensional kinetic ablation theory of the hydrogen pellet ablation developed by Kuteev [B.V. Kuteev, Nuclear Fusion, 35 (1995) 431], an algorithm of erosion speed and ablation rate calculations for Li, Be, and B impurity pellets in reactor-relevant plasma has been derived. Results show compatibilities of lithium pellet injection used in α-particle diagnostics are positive in comparison with other solid impurity pellets (e.g. Be, B and C). Using the 2-D Kuteev lentil model, including kinetic effects, we find that currently existing pellet injection techniques will not meet core-fueling requirements for ITER-FEAT. A pressure as high as 254 MPa must be applied to a pellet accelerator with a 200 cm-long single-stage pneumatic gun, in order to accelerate a pellet with a radius rp0 = 0.5 cm to a velocity of νp0, 24 × 105 cm/s penetrating 100 cm into the ITER plasma core. Comparisons of pellet velocity- and radius-dependent penetration depth between the Neutral Gas Shielding and the Kuteev's models are made. However, we find that the isotopic effects can lead to a 33% lower pellet speed for solid DT, compared to an identical H2 pellet penetrating the same length in ITER-FEAT plasma, and our calculations show that HFS injection will much improve core fueling efficiency.

  19. Safety characteristics of a suspended-pellet fission reactor system

    NASA Astrophysics Data System (ADS)

    Kingdon, David Ross

    A new fission reactor system with passive safety characteristics to eliminate the occurrence of loss-of-coolant accidents, reduce reactivity excursion effects, and which also provides for closure of the nuclear fuel cycle through on-site spent fuel management is examined. The concept uses multi-coated fuel pellets which are suspended by an upward moving coolant in vertical columns of the reactor core and electro-refining elemental separation to remove selected fission products prior to actinide recycling. The possibility of fuel melt following a loss-of-coolant is avoided as a decrease in coolant flow results in the removal of fuel from the core through the action of gravity alone. Average fluid velocities in the columns which are necessary to suspend the pellets are calculated and found to be consistent with the necessary heat extraction to yield ˜1--10 Wth per column. The total output power of such suspended pellet-type reactors is compared to the power necessary to provide the suspending fluid flow, yielding favourable ratios of ˜102--103. The reduction of reactivity excursion tendencies is envisaged through an ablative layer of material in the pellets which sublimates at temperatures above normal operating conditions. In the event of a power or temperature increase the particles fragment and thereby change their hydrodynamic drag characteristics, thus leading to fuel removal from the core by elutriation. Comparison of nuclear-to-thermal response times and elutriation rates for limiting power transients indicate that the present design assists in reactivity excursion mitigation. Closure of the nuclear fuel cycle is attained through a spent fuel management strategy which requires only on-site storage of a fraction of the fission products produced during reactor operation. Electro-refining separation of selected fission products combined with complete actinide recycling yields no isolation of plutonium or highly enriched uranium during the procedure. The out

  20. Carbonation as a binding mechanism for coal/calcium hydroxide pellets. Technical report, December 1, 1992--February 28, 1993

    SciTech Connect

    Rapp, D.; Lytle, J.; Hackley, K.; Dagamac, M.; Berger, R.; Schanche, G.

    1993-05-01

    Pelletization of fine coal with calcium hydroxide, a sulfur capturing sorbent, represents a method to produce a fuel which will burn in compliance with the recently passed Clean Air Act Amendments (CAAA`s). To harden the pellets, the reaction of carbon dioxide with calcium hydroxide, referred to as carbonation, is being studied. Carbonation forms a bonding matrix of calcium carbonate. This is a two-year research program. This report covers the second quarter of the second year. Research is indicating that 5 to 10 wt% calcium hydroxide pellets can be produced via a roller-and-die pellet mill and air cured to achieve sufficient quality for handling and transportation. This quarter, 1/2 inch-diameter pellets containing 10% calcium hydroxide were demonstrated to gradually react with atmospheric carbon dioxide (3 days) while air drying to achieve compressive strengths equivalent to those attained for fully dried pellets which had been carbonated for one-hour with 100% commercial grade carbon dioxide. It was also demonstrated that an organic, adhesive binder, corn starch, can be very effective at producing strong pellets but drying is required before appreciable pellet strength is attained. For pellets containing 2 wt% corn starch, it was determined that less than 50% of the ultimate strength was achieved as the pellets were dried from 20 wt% to 5 wt% moisture. Strength improved considerably as the pellet moisture content was reduced below 5 wt%.

  1. Potential of duplex fuel in prebreeder, breeder, and power reactor designs: tests and analyses (AWBA Development Program)

    SciTech Connect

    Chao, T.L.; Brennan, J.J.; Duncombe, E.; Schneider, M.J.; Johnson, R.G.R.

    1982-09-01

    Dual region fuel pellets, called duplex pellets, are comprised of an outer annular region of relatively high uranium fuel enrichment and a center pellet of fertile material with no enrichment. UO/sub 2/ and ThO/sub 2/ are the fissile and fertile materials of interest. Both prebreeders and breeders are discussed as are the performance advantages of duplex pellets over solid pellets in these two pressurized water reactor types. Advantages of duplex pellets for commercial reactor fuel rods are also discussed. Both irradiation test data and analytical results are used in comparisons. Manufacturing of duplex fuel is discussed.

  2. A mathematical model to predict the size of the pellets formed in freeze pelletization techniques: parameters affecting pellet size.

    PubMed

    Cheboyina, Sreekhar; O'Haver, John; Wyandt, Christy M

    2006-01-01

    A mathematical model was developed based on the theory of drop formation to predict the size of the pellets formed in the freeze pelletization process. Further the model was validated by studying the effect of various parameters on the pellet size such as viscosity of the pellet forming and column liquids, surface/interfacial tension, density difference between pellet forming and column liquids; size, shape, and material of construction of the needle tips and temperatures maintained in the columns. In this study, pellets were prepared from different matrices including polyethylene glycols and waxes. The column liquids studied were silicone oils and aqueous glycerol solutions. The surface/interfacial tension, density difference between pellet forming and column liquids and needle tip size were found to be the most important factors affecting pellet size. The viscosity of the column liquid was not found to significantly affect the size of the pellets. The size of the pellets was also not affected by the pellet forming liquids of low viscosities. An increase in the initial column temperature slightly decreased the pellet size. The mathematical model developed was found to successfully predict the size of the pellets with an average error of 3.32% for different matrices that were studied.

  3. U.S. Pellet Industry Analysis

    SciTech Connect

    Corrie I. Nichol; Jacob J. Jacobsen; Richard D. Boardman

    2011-06-01

    This report is a survey of the U.S. Pellet Industry, its current capacity, economic drivers, and projected demand for biomass pellets to meet future energy consumption needs. Energy consumption in the US is projected to require an ever increasing portion of renewable energy sources including biofuels, among which are wood, and agrictulrual biomass. Goals set by federal agencies will drive an ever increasing demand for biomass. The EIA projections estimate that renewable energy produced by 2035 will be roughly 10% of all US energy consumption. Further analysis of the biofuels consumption in the US shows that of the renewable energy sources excluding biofuels, nearly 30% are wood or biomass waste. This equates to roughly 2% of the total energy consumption in the US coming from biomass in 2009, and the projections for 2035 show a strong increase in this amount. As of 2009, biomass energy production equates to roughly 2-2.5 quadrillion Btu. The EIA projections also show coal as providing 21% of energy consumed. If biomass is blended at 20% to co-fire coal plants, this will result in an additional 4 quadrillion Btu of biomass consumption. The EISA goals aim to produce 16 billion gal/year of cellulosic biofuels, and the US military has set goals for biofuels production. The Air Force has proposed to replace 50% of its domestic fuel requirements with alternative fuels from renewable sources by 2016. The Navy has likewise set a goal to provide 50% of its energy requirements from alternative sources. The Department of Energy has set similarly ambitious goals. The DOE goal is to replace 40% of 2004 gasoline use with biofuels. This equates to roughly 60 billion gal/year, of which, 45 billion gal/year would be produced from lignocellulosic resources. This would require 530 million dry tons of herbaceous and woody lignocellulosic biomass per year.

  4. The impact of interface bonding efficiency on high-burnup spent nuclear fuel dynamic performance

    SciTech Connect

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

    2016-09-26

    Finite element analysis (FEA) was used to investigate the impact of interfacial bonding efficiency at pellet-pellet and pellet-clad interfaces of high-burnup (HBU) spent nuclear fuel (SNF) on system dynamic performance. Bending moments M were applied to FEA model to evaluate the system responses. From bending curvature, κ, flexural rigidity EI can be estimated as EI = M/κ. The FEA simulation results were benchmarked with experimental results from cyclic integrated reversal bending fatigue test (CIRFT) of HBR fuel rods. The consequence of interface debonding between fuel pellets and cladding is a redistribution of the loads carried by the fuel pellets to the clad, which results in a reduction in composite rod system flexural rigidity. Furthermore, the interface bonding efficiency at the pellet-pellet and pellet-clad interfaces can significantly dictate the SNF system dynamic performance. With the consideration of interface bonding efficiency, the HBU SNF fuel property was estimated with CIRFT test data.

  5. The impact of interface bonding efficiency on high-burnup spent nuclear fuel dynamic performance

    SciTech Connect

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

    2016-09-26

    Finite element analysis (FEA) was used to investigate the impact of interfacial bonding efficiency at pellet-pellet and pellet-clad interfaces of high-burnup (HBU) spent nuclear fuel (SNF) on system dynamic performance. Bending moments M were applied to FEA model to evaluate the system responses. From bending curvature, κ, flexural rigidity EI can be estimated as EI = M/κ. The FEA simulation results were benchmarked with experimental results from cyclic integrated reversal bending fatigue test (CIRFT) of HBR fuel rods. The consequence of interface debonding between fuel pellets and cladding is a redistribution of the loads carried by the fuel pellets to the clad, which results in a reduction in composite rod system flexural rigidity. Furthermore, the interface bonding efficiency at the pellet-pellet and pellet-clad interfaces can significantly dictate the SNF system dynamic performance. With the consideration of interface bonding efficiency, the HBU SNF fuel property was estimated with CIRFT test data.

  6. COMPARTMENTED REACTOR FUEL ELEMENT

    DOEpatents

    Cain, F.M. Jr.

    1962-09-11

    A method of making a nuclear reactor fuel element of the elongated red type is given wherein the fissionable fuel material is enclosed within a tubular metal cladding. The method comprises coating the metal cladding tube on its inside wall with a brazing alloy, inserting groups of cylindrical pellets of fissionable fuel material into the tube with spacing members between adjacent groups of pellets, sealing the ends of the tubes to leave a void space therewithin, heating the tube and its contents to an elevated temperature to melt the brazing alloy and to expand the pellets to their maximum dimensions under predetermined operating conditions thereby automatically positioning the spacing members along the tube, and finally cooling the tube to room temperature whereby the spacing disks become permanently fixed at their edges in the brazing alloy and define a hermetically sealed compartment for each fl group of fuel pellets. Upon cooling, the pellets contract thus leaving a space to accommodate thermal expansion of the pellets when in use in a reactor. The spacing members also provide lateral support for the tubular cladding to prevent collapse thereof when subjected to a reactor environment. (AEC)

  7. Bimodal, Low Power Pellet Bed Reactor System Design Concept

    NASA Astrophysics Data System (ADS)

    El-Genk, Mohamed S.; Liscum-Powell, Jennifer; Pelaccio, Dennis G.

    1994-07-01

    A conceptual design is presented of a bimodal system that employs a pellet bed reactor heat source, helium-xenon Closed Brayton Cycle (CBC) engines, UC fuel, super-alloy structure materials, and hydrogen for propulsion operation. In addition to incorporating state-of-the-art, low risk technologies, and as much off-the-shelf hardware as possible in order to meet a near-term flight demonstration date, the system offers unique design and safety features. These design features include: (a) modularity to support a wide range of electric power and thermal propulsion requirements, (b) sectored, annular reactor core and multiple CBC engines for redundancy and to eliminate a single point failure in the coolant loop, (c) efficient CBC engines, (d) low maximum fuel temperature (<1600 K) that is maintained almost constant during power and propulsion modes, (e) spherical fuel mini-spheres or pellets that provide full retention of fission products and scalability to higher power levels, (f) two independent reactor control systems with built-in redundancy, (h) passive decay heat removal from the reactor core, (g) ground testing of the fully assembled system using electric heaters and unfueled mini-spheres or pellets, (h) negative temperature reactivity feedback for improved reactor operation and safety, (i) high specific impulse (650s-750s) and specific power (11.0- 21.9 We/kg), at relatively low power levels (10-40 kWe).

  8. Carbonation as a binding mechanism for coal/calcium hydroxide pellets

    SciTech Connect

    Rapp, D.M.

    1991-01-01

    Current coal mining and processing procedures produce a significant quanity of fine coal that is difficult to handle and transport. The objective of this work is to determine if these fines can be economically pelletized with calcium hydroxide, a sulfur capturing sorbent, to produce a clean-burning fuel for fluidized-bed combustors or stoker boilers. To harden these pellets, carbonation, which is the reaction of calcium hydroxide with carbon dioxide to produce a cementitious matrix of calcium carbonate, is being investigated. Previous research indicated that carbonation significantly improved compressive strength, impact and attrition resistance and weatherproofed'' pellets formed with sufficient calcium hydroxide (5 to 10% for minus 28 mesh coal fines).

  9. A New Four-Barrel Pellet Injection System for the TJ-II Stellarator

    SciTech Connect

    Combs, Stephen Kirk; Foust, Charles R; McGill, James M; Baylor, Larry R; Caughman, John B; Fehling, Dan T; Harris, Jeffrey H; Meitner, Steven J; Rasmussen, David A; McCarthy, K. J.; Chamorro, M.; Garcia, R.; Hildago, C.; Medrano, M.; Unamuno, R.

    2011-01-01

    A new pellet injection system for the TJ-II stellarator has been developed/constructed as part of a collaboration between the Oak Ridge National Laboratory (ORNL) and the Centro de Investigaciones Energ ticas, Medioambientales y Tecnol gicas (CIEMAT). ORNL is providing most of the injector hardware and instrumentation, the pellet diagnostics, and the pellet transport tubes; CIEMAT is responsible for the injector stand/interface to the stellarator, cryogenic refrigerator, vacuum pumps/ballast volumes, gas manifolds, remote operations, plasma diagnostics, and data acquisition. The pellet injector design is an upgraded version of that used for the ORNL injector installed on the Madison Symmetric Torus (MST). It is a four-barrel system equipped with a cryogenic refrigerator for in situ hydrogen pellet formation and a combined mechanical punch/propellant valve system for pellet acceleration (speeds ~100 to 1000 m/s). On TJ-II, it will be used as an active diagnostic and for fueling. To accommodate the plasma experiments planned for TJ-II, pellet sizes significantly smaller than those typically used for the MST application are required. The system will initially be equipped with four different pellet sizes, with the gun barrel bores ranging between ~0.5 to 1.0 mm. The new system is almost complete and is described briefly here, highlighting the new features added since the original MST injector was constructed. Also, the future installation on TJ-II is reviewed.

  10. Pelletizing/reslurrying as a means of distributing and firing clean coal. Final quarterly technical progress report No. 7, January 1, 1992-- March 31, 1992

    SciTech Connect

    Conkle, H.N.

    1992-06-09

    Work in this quarter focused on completing (1) the final batch of pilot-scale disk pellets, (2) storage, handling, and transportation evaluation, (3) pellet reslurrying and atomization studies, and (4) cost estimation for pellet and slurry production. Disk pelletization of Elkhorn coal was completed this quarter. Pellets were approximately 1/2- to 3/4-in. in diameter. Pellets, after thermal curing were strong and durable and exceeded the pellet acceptance criteria. Storage and handling tests indicate a strong, durable pellet can be prepared from all coals, and these pellets (with the appropriate binder) can withstand outdoor, exposed storage for at least 4 weeks. Pellets in unexposed storage show no deterioration in pellet properties. Real and simulated transportation tests indicate truck transportation should generate less than 5 percent fines during transport. Continuous reslurrying testing and subsequent atomization evaluation were performed this quarter in association with University of Alabama and Jim Walter Resources. Four different slurries of approximately 55-percent-solids with viscosities below 500 cP (at 100 sec{sup {minus}1}) were prepared. Both continuous pellet-to-slurry production and atomization testing was successfully demonstrated. Finally, an in depth evaluation of the cost to prepare pellets, transport, handle, store, and convert the pellet into Coal Water Fuel (CWF) slurries was completed. Cost of the pellet-CWF option are compared with the cost to directly convert clean coal filter cake into slurry and transport, handle and store it at the user site. Findings indicate that in many circumstances, the pellet-CWF option would be the preferred choice. The decision depends on the plant size and transportation distance, and to a lesser degree on the pelletization technique and the coal selected.

  11. Electrothermal plasma gun as a pellet injector

    SciTech Connect

    Kincaid, R.W.; Bourham, M.A.

    1994-11-01

    The NCSU electrothermal plasma gun SIRENS has been used to accelerate plastic (Lexan polycarbonate) pellets, to determine the feasibility of the use of electrothermal guns as pellet injectors. The use of an electrothermal gun to inject frozen hydrogenic pellets requires a mechanism to provide protective shells (sabots) for shielding the pellet from ablation during acceleration into and through the barrel of the gun. The gun has been modified to accommodate acceleration of the plastic pellets using special acceleration barrels equipped with diagnostics for velocity and position of the pellet, and targets to absorb the pellet`s energy on impact. The length of the acceleration path could be varied between 15 and 45 cm. The discharge energy of the electrothermal gun ranged from 2 to 6 kJ. The pellet velocities have been measured via a set of break wires. Pellet masses were varied between 0.5 and 1.0 grams. Preliminary results on 0.5 and 1.0 g pellets show that the exit velocity reaches 0.9 km/s at 6 kJ input energy to the source. Higher velocities of 1.5 and 2.7 km/s have been achieved using 0.5 and 1.0 gm pellets in 30 cm long barrel, without cleaning the barrel between the shots.

  12. A Characterization and Evaluation of Coal Liquefaction Process Streams. Results of Inspection Tests on Nine Coal-Derived Distillation Cuts in the Jet Fuel Boiling Range

    SciTech Connect

    S. D. Brandes; R. A. Winschel

    1999-12-30

    This report describes the assessment of the physical and chemical properties of the jet fuel (180-300 C) distillation fraction of nine direct coal liquefaction products and compares those properties to the corresponding specifications for aviation turbine fuels. These crude coal liquids were compared with finished fuel specifications specifically to learn what the refining requirements for these crudes will be to make them into finished fuels. The properties of the jet fuel fractions were shown in this work to require extensive hydrotreating to meet Jet A-1 specifications. However, these materials have a number of desirable qualities as feedstocks for the production of high energy-density jet fuels.

  13. Results of combustion and emissions testing when co-firing blends of binder-enhanced densified refuse-derived fuel (b-dRDF) pellets and coal in a 440 MW{sub e} cyclone fired combustor. Volume 3: Appendices

    SciTech Connect

    Ohlsson, O.

    1994-07-01

    This report contains the data resulting from the co-firing of b-dRDF pellets and coal in a 440-MW{sub e} cyclone-fired combustor. These tests were conducted under a Collaborative Research and Development Agreement (CRADA). The CRADA partners included the U.S. Department of Energy (DOE), National Renewable Energy Laboratory (NREL), Argonne National Laboratory (ANL), Otter Tail Power Company, Green Isle Environmental, Inc., XL Recycling Corporation, and Marblehead Lime Company. The report is made up of three volumes. This volume contains other supporting information, along with quality assurance documentation and safety and test plans. With this multi-volume approach, readers can find information at the desired level of detail, depending on individual interest or need.

  14. A model for the effective thermal and mechanical properties of cracked UO/sub 2/ pellets

    SciTech Connect

    Williford, R.E.; Lanning, D.D.; Mohr, C.L.

    1982-02-01

    An alternate thermal-mechanical behavior model for cracked UO/sub 2/ pelletized fuel is presented. It is recognized that fuel cracking and relocation cause some of the initial pellet-cladding gap (the ''free area'') to be moved into the fuel in the form of cracks. The introduction of this free area into the fuel causes the fuel effective thermal conductivity and effective elastic moduli to be simultaneously reduced to values significantly less than laboratory data for solid pellets. Hooke's Law and a crack compliance model are used to deduce the effective fuel conductivity and moduli from simultaneous in-reactor measurements of rod power, fuel center temperature, and cladding elongation. The fuel-cladding ''gap'' is considered as another ''crack,'' and is also described by the crack compliance model, which predicts that there is always some finite amount of fuelcladding contact. The primary thermal mechanical feedback mechanism is found to be due to crack closure effects on fuel effective thermal conductivity, rather than gap closure effects on gap conductance.

  15. Speed limit of frozen pellets (H{sub 2}, D{sub 2}, and Ne) through single-loop and multiloop tubes and implications for fusion plasma research

    SciTech Connect

    Combs, S. K.; Griffith, A. E.; Foust, C. R.

    2001-01-01

    Frozen pellets (H{sub 2}, D{sub 2}, and Ne at 8 K) of nominal 2.7 mm diam were shot through a coiled tube (single loop of {approx}0.6 m diam and 8.5 mm bore), and the speed limit for survival was recorded for each pellet type. Intact H{sub 2} pellets were observed at speeds approaching 500 m/s; but neon pellets could not survive much more than 100 m/s. The speed limit for D{sub 2} pellets fell in the middle at {approx}300 m/s. Some D{sub 2} pellets were also shot through a 30 m coiled tube consisting of 11 loops (average loop diameter of {approx}0.8 m), and a speed limit of {approx}100 m/s was observed. Injection of frozen H{sub 2} or D{sub 2} pellets is commonly used for core fueling of magnetically confined plasmas, and frozen neon pellets are sometimes used for impurity transport studies in similar experiments. The results from these tests add to a pellet database for injection lines with single- and complex multiple-curved guide tubes. All of the information to date suggests that frozen pellets can be delivered reliably from a pellet source to any accessible plasma location on a fusion device via ''roller-coaster'' tubes as long as the pellet speed is maintained below a threshold limit.

  16. Binder enhanced refuse derived fuel

    DOEpatents

    Daugherty, Kenneth E.; Venables, Barney J.; Ohlsson, Oscar O.

    1996-01-01

    A refuse derived fuel (RDF) pellet having about 11% or more particulate calcium hydroxide which is utilized in a combustionable mixture. The pellets are used in a particulate fuel bring a mixture of 10% or more, on a heat equivalent basis, of the RDF pellet which contains calcium hydroxide as a binder, with 50% or more, on a heat equivalent basis, of a sulphur containing coal. Combustion of the mixture is effective to produce an effluent gas from the combustion zone having a reduced SO.sub.2 and polycyclic aromatic hydrocarbon content of effluent gas from similar combustion materials not containing the calcium hydroxide.

  17. Repeating pneumatic pipe-gun for plasma fueling

    NASA Astrophysics Data System (ADS)

    Viniar, I.; Sudo, S.

    1997-03-01

    A pellet injector of the repeating pneumatic pipe-gun type has been designed for plasma fueling applications. Its use reduces the time for pellet formation by an in situ technique from 2 to 3 min to 2-10 s. The basic idea of the proposed approach to pellet formation is to melt prefrozen solid fuel and to admit it through a porous unit into a barrel for refreezing. The injector provides for a continuous injection of an unlimited number of pellets. Over 250 hydrogen and deuterium pellets of 3 mm diameter and 3-10 mm in length were accelerated to 1.2 km/s at a rate of 1 pellet per 10-34 s by manually controlled injector operation. An automatically controlled multishot pellet injector (>10 barrels) is capable of providing a continuous and reliable fueling of large fusion devices such as the large helical device and the International Thermonuclear Experimental Reactor (ITER).

  18. Fabrication of thorium bearing carbide fuels

    DOEpatents

    Gutierrez, R.L.; Herbst, R.J.; Johnson, K.W.R.

    Thorium-uranium carbide and thorium-plutonium carbide fuel pellets have been fabricated by the carbothermic reduction process. Temperatures of 1750/sup 0/C and 2000/sup 0/C were used during the reduction cycle. Sintering temperatures of 1800/sup 0/C and 2000/sup 0/C were used to prepare fuel pellet densities of 87% and > 94% of theoretical, respectively. The process allows the fabrication of kilogram quantities of fuel with good reproductibility of chemical and phase composition.

  19. Model for pneumatic pellet injection

    SciTech Connect

    Hogan, J.T.; Milora, S.L.; Schuresko, D.D.

    1983-07-01

    A hydrodynamic code has been developed to model the performance of pneumatic pellet injection systems. The code describes one dimensional, unsteady compressible gas dynamics, including gas friction and heat transfer to the walls in a system with variable area. The mass, momentum, and energy equations are solved with an iterated Lax-Wendroff scheme with additional numerical viscosity. The code is described and comparisons with experimental data are presented.

  20. Numerical characterization of micro-cell UO2sbnd Mo pellet for enhanced thermal performance

    NASA Astrophysics Data System (ADS)

    Lee, Heung Soo; Kim, Dong-Joo; Kim, Sun Woo; Yang, Jae Ho; Koo, Yang-Hyun; Kim, Dong Rip

    2016-08-01

    Metallic micro-cell UO2 pellet with high thermal conductivity has received attention as a promising accident-tolerant fuel. Although experimental demonstrations have been successful, studies on the potency of current metallic micro-cell UO2 fuels for further enhancement of thermal performance are lacking. Here, we numerically investigated the thermal conductivities of micro-cell UO2sbnd Mo pellets in terms of the amount of Mo content, the unit cell size, and the aspect ratio of the micro-cells. The results showed good agreement with experimental measurements, and more importantly, indicated the importance of optimizing the unit cell geometries of the micro-cell pellets for greater increases in thermal conductivity. Consequently, the micro-cell UO2sbnd Mo pellets (5 vol% Mo) with modified geometries increased the thermal conductivity of the current UO2 pellets by about 2.5 times, and lowered the temperature gradient within the pellets by 62.9% under a linear heat generation rate of 200 W/cm.

  1. Pellet fabrication development using thermally denitrated UO sub 2 powder

    SciTech Connect

    Davis, N.C.; Griffin, C.W.

    1992-05-01

    Pacific Northwest Laboratory (PNL) has evaluted, on a laboratory scale, the characteristics and pellet fabrication properties of UO{sub 3} powder prepared by the thermal denitration process. Excellent quality, 96% TD (percent of theoretical density) pellets were produced from development lots of this powder. Apparently, the key to making this highly sinterable powder from uranyl nitrate is the addition of ammonium nitrate (NH{sub 4}NO{sub 3}) to the feed solution prior to thermal denitration. Powder lots were processed with and without the NH{sub 4}NO{sub 3} addition in the feed solution. The lots included samples from the ORNL laboratory rotary kiln and from a larger scale rotary kiln at National Lead of Ohio (NLO). In the PNL evaluation, samples of UO{sub 3} were calculated and reduced to UO{sub 2}, followed by conventional process procedures to compare the sinterability of the powder lots. The high density pellets made from the powder lots, which included the NH{sub 4}NO{sub 3} addition, were reduced to Fast Breeder Reactor (FBR) density range of 88 to 92% TD by the use of poreformers. The NH{sub 4}NO{sub 3} addition also improved the sinterability properties of uranium oxide powders that contain thorium and cerium. Thorium and cerium were used as stand-in'' for plutonium used in urania-plutonia FBR fuel pellets. A very preliminary examination of a single lot of thermally denitrated uranium-plutonium oxide powder was made. This powder lot was made with the NH{sub 3}NO{sub 3} addition and produced pellets just above the FBR density range.

  2. Analysis of Pelletizing of Granulometric Separation Powder from Cork Industries

    PubMed Central

    Montero, Irene; Miranda, Teresa; Sepúlveda, Francisco José; Arranz, José Ignacio; Nogales, Sergio

    2014-01-01

    Cork industries generate a considerable amount of solid waste during their processing. Its management implies a problem for companies that should reconsider its reuse for other purposes. In this work, an analysis of pelletizing of granulometric separation powder, which is one of the major wastes in cork industries and which presents suitable properties (as an raw material) for its thermal use, is studied. However, its characteristic heterogeneity, along with its low bulk density (which makes its storage and transportation difficult) are restrictive factors for its energy use. Therefore, its densified form is a real alternative in order to make the product uniform and guarantee its proper use in boiler systems. Thus, the cork pellets (from granulometric separation powder) in the study met, except for ash content specification, the specifications in standard European Norm EN-Plus (B) for its application as fuel for domestic use. PMID:28788207

  3. Snake perturbation during pellet injection in the EAST tokamak

    NASA Astrophysics Data System (ADS)

    Yao, Xingjia; Hu, Jiansheng; Xu, Liqing; Xu, Zong; Chen, Yue; Li, Changzheng; Liu, Haiqing; Zhao, Hailing; Duan, Yanmin; Shi, Tonghui; Shen, Wei; EAST Team

    2016-11-01

    The pellet-induced snake oscillation was observed by soft x-ray (SXR) diagnostic in EAST for the first time after a fueling-sized pellet penetrated the q  =  1 surface. The snake phenomenon has a long lifetime with a helicity of m  =  1 and n  =  1. Basic behaviors of the snake, including the triggering condition, interaction with the sawtooth and snake rotation frequency, were discussed in detail by multiple core diagnostics. The snake location was also analyzed through observation of the vertical SXR arrays and raw SXR brightness profiles. It is clear that the snake resided in a broad region between the magnetic axis and the q  =  1 surface derived from equilibrium reconstruction. This investigation is beneficial for the understanding of the snake formation for EAST and future devices, like ITER and DEMO.

  4. Twenty barrel in situ pipe gun type solid hydrogen pellet injector for the Large Helical Device.

    PubMed

    Sakamoto, Ryuichi; Motojima, Gen; Hayashi, Hiromi; Inoue, Tomoyuki; Ito, Yasuhiko; Ogawa, Hideki; Takami, Shigeyuki; Yokota, Mitsuhiro; Yamada, Hiroshi

    2013-08-01

    A 20 barrel solid hydrogen pellet injector, which is able to inject 20 cylindrical pellets with a diameter and length of between 3.0 and 3.8 mm at the velocity of 1200 m/s, has been developed for the purpose of direct core fueling in LHD (Large Helical Device). The in situ pipe gun concept with the use of compact cryo-coolers enables stable operation as a fundamental facility in plasma experiments. The combination of the two types of pellet injection timing control modes, i.e., pre-programing mode and real-time control mode, allows the build-up and sustainment of high density plasma around the density limit. The pellet injector has demonstrated stable operation characteristics during the past three years of LHD experiments.

  5. Direct alpha spectrometry for analysing leached ThO2 pellets

    NASA Astrophysics Data System (ADS)

    Myllykylä, E.; Koivula, L.; Tanhua-Tyrkkö, M.; Helariutta, K.; Lavonen, T.; Ollila, K.; Siitari-Kauppi, M.

    2017-09-01

    The next generation application of nuclear energy has shown an interest towards ThO2 or mixed oxides fuels. However, more knowledge is needed, for example, on the microstructural and matrix dissolution behaviour of ThO2. The objective of this study was to examine surface properties of thick ThO2 pellets by non-destructive alpha analysis method accompanied with Monte Carlo simulations before and after a leaching experiment. This study has been conducted to investigate the contents, and surface layer thickness of crystalline 232ThO2 pellet leached in aqueous solution with excess of 229Th tracer in the beginning of the experiment. The simulation results have suggested a maximum 0.1 μm concentrated layer of 229Th on the pellet surface. The presence of this layer suppresses further dissolution of the pellet.

  6. [Study on preparation of Qixian decoction pellets in tangential spray fluid bed].

    PubMed

    Luo, Xiaojian; Zhang, Guosong; Huang, Fengrong; Rao, Xiaoyong; He, Yan; Hu, Pengyi

    2009-03-01

    To prepare Qixian decoction pellets. The formulation and technological factors influencing the preparation of Qixian decoction were investigated in tangential spray fluid bed choosing the yield of pellets, particle diameter distribution, repose angle, bulk density as inspecting indexes. the technological parameters for the preparation of blank pellets were as follows: the ratio of starch and dextrin was 2:1, the adhesive agent was 70% syrup, the rotating speed was 200 r x min(-1), the air blow flow was 15 x 20 L x min(-1), the rate of air flow was 15 L x min(-1), the spay air pressure was 0.15 MPa, and the rotating rate of spray solution pump was 20-50 r x min(-1); The optimized technological parameters for the preparation of Qixian decoction were as follows: the relative density of the extract was 1.12-1.15 g x min(-1), the diluent was MCC and its quantity was 8%, the rotating rate of spray solution pump was 10-12 mL x min(-1), the frequency of the rotor disc was 18-20 Hz, the atomizing pressure was 0.2 MPa, the frequency of the fan was 22 Hz, and the spheronisation and drying time was 30 mins. the appearance of the Qixian decoction pellets prepared in tangential spray fluid bed are smoothing and round, the yield of pellets are high, and pellets of the particle size between 500-700 microm is 90.6%.

  7. Pelletizing/reslurrying as a means of distributing and firing clean coal

    SciTech Connect

    Conkle, H.N.

    1992-09-29

    Battelle-Columbus and Amax Research Development conducted a program to develop a process to transport, handle, store, and utilize ultra-fine, ultra-clean (UFUC) coals. The primary objective was to devise a cost-effective method, based on conventional pelletization techniques, to transform the sludge-like filter cake produced in advanced flotation cleaning processes into a product which could be used like lump coal. A secondary objective was the production of a pellet which could be readily converted into a coal water fuel (CWF) because the UFUC coal would ultimately be used as CWF. The resulting product would be a hard, waterproof pellet which could be easily reduced to small particle sizes and formulated with water into a liquid fuel.

  8. Pelletizing/reslurrying as a means of distributing and firing clean coal. Final report

    SciTech Connect

    Conkle, H.N.

    1992-09-29

    Battelle-Columbus and Amax Research & Development conducted a program to develop a process to transport, handle, store, and utilize ultra-fine, ultra-clean (UFUC) coals. The primary objective was to devise a cost-effective method, based on conventional pelletization techniques, to transform the sludge-like filter cake produced in advanced flotation cleaning processes into a product which could be used like lump coal. A secondary objective was the production of a pellet which could be readily converted into a coal water fuel (CWF) because the UFUC coal would ultimately be used as CWF. The resulting product would be a hard, waterproof pellet which could be easily reduced to small particle sizes and formulated with water into a liquid fuel.

  9. Upgrading of consumer characteristics of granulated solid fuel from mixture of low-grade coal and biomass

    NASA Astrophysics Data System (ADS)

    Kuzmina, J. S.; Milovanov, O. Yu; Sinelshchikov, V. A.; Sytchev, G. A.; Zaichenko, V. M.

    2015-11-01

    Effect of torrefaction on consumer characteristics of fuel pellets made of low-grade and agricultural waste is shown. Data on the volatile content, ash content, calorific value and hygroscopicity for initial pellets and pellets, heat-treated at various temperatures are presented. The experimental study of the combustion process of initial and heat-treated pellets showed that torrefaction of pellets leads to a decreasing of the ignition temperature and an increasing of the efficiency of boiler plant.

  10. Inspection and Short-Term Measurement of a National Park Service Photovoltaic/Fuel Cell Remote Hybrid Power System at Kirby Cove, California: Preprint

    SciTech Connect

    Walker, A.; Barker, G.; Christensen, J.; Rawlings, L.

    2002-02-01

    This paper reports short-term performance measurements of a hybrid photovoltaic/fuel cell power supply system at Kirby Cove Campground, Golden Gate National Recreation Area, California. The system operated reliably for two years from June 1999 to June 2001. A combination of solar power and power from the fuel cell supplied the campground host power load. In 2001, reports of power outages prompted an investigation. Data are reported for 13.5 days from September 2 to September 15, 2001. Over this time, the photovoltaic array delivered 42.82 kWh, the fuel cell delivered 1.34 kWh, and the net energy from the battery was 6.82 kWh. Photovoltaic efficiency was measured at 8.9%, and fuel cell efficiency at 42%, a typical value. But fuel cell power output was only 35 W, not 250 W, the rated power. Replacing a burnt fuse restored fuel cell power to 125 W, but several cells had low voltage, so the fuel cell was removed for repair or replacement. After the fuel cell failed, loads exceeding the solar capability discharged the batteries; the total for the eight power outages was 48 hours. This paper describes the system's daily operation, presents performance indicators, identifies some causes of performance degradation, and recommends improvements.

  11. Impurity pellet injection experiments at TFTR

    SciTech Connect

    Marmar, E.S.

    1992-01-01

    Impurity (Li and C) pellet injection experiments on TFTR have produced a number of new and significant results. (1) We observe reproducible improvements of TFTR supershots after wall-conditioning by Li pellet injection ( lithiumization'). (2) We have made accurate measurements of the pitch angle profiles of the internal magnetic field using two novel techniques. The first measures the internal field pitch from the polarization angles of Li[sup +] line emission from the pellet ablation cloud, while the second measures the pitch angle profiles by observing the tilt of the cigar-shaped Li[sup +] emission region of the ablation cloud. (3) Extensive measurements of impurity pellet penetration into plasmas with central temperatures ranging from [approximately]0.3 to [approximately]7 keV have been made and compared with available theoretical models. Other aspects of pellet cloud physics have been investigated. (4) Using pellets as a well defined perturbation has allowed study of transport phenomena. In the case of small pellet perturbations, the characteristics of the background plasmas are probed, while with large pellets, pellet induced effects are clearly observed. These main results are discussed in more detail in this paper.

  12. 25 years of pelletizing at CVRD

    SciTech Connect

    Bandeira de Mello, L.A.; Mourao, J.M.; Cunha, J.M.; Piccolo, A.L.; Klein, M.S.

    1996-12-31

    This paper presents the evolution of the iron ore pelletizing activities at Companhia Vale do Rio Doce (CVRD), since the start-up of the first plant in the Tubarao area (Brazil), in 1969. The main features of CVRD`s pelletizing activities are described, focusing on the development of different types of pellets for the blast furnace and direct reduction markets, on the actions taken to face the urging necessity of cutting down energetic costs and on the handling of several different types of raw material. The profile of process control, quality management and environmental control at CVRD`s pelletizing plants is also presented.

  13. L'Anse Warden Inspection April 2012

    EPA Pesticide Factsheets

    EPA Water enforcement program staff inspected both the L'Anse Warden Fuel Aggregation Facility and Plant on April 26-27, 2012. EPA issued an administrative order. L'Anse Warden submitted a revised stormwater pollution prevention plan.

  14. Plastic pellets as oviposition site and means of dispersal for the ocean-skater insect Halobates.

    PubMed

    Majer, A P; Vedolin, M C; Turra, A

    2012-06-01

    Microplastics are omnipresent in the oceans and generally have negative impacts on the biota. However, flotsam may increase the availability of hard substrates, which are considered a limiting resource for some oceanic species, e.g. as oviposition sites for the ocean insect Halobates. This study describes the use of plastic pellets as an oviposition site for Halobates micans and discusses possible effects on its abundance and dispersion. Inspection of egg masses on stranded particles on beaches revealed that a mean of 24% (from 0% to 62%) of the pellets bore eggs (mean of 5 and max. of 48 eggs per pellet). Most eggs (63%) contained embryos, while 37% were empty egg shells. This shows that even small plastic particles are used as oviposition site by H. micans, and that marine litter may have a positive effect over the abundance and dispersion of this species.

  15. Spent Nuclear Fuel Vibration Integrity Study

    SciTech Connect

    Wang, Jy-An John; Wang, Hong; Jiang, Hao; Yan, Yong; Bevard, Bruce Balkcom

    2016-01-01

    The objective of this research is to collect dynamic experimental data on spent nuclear fuel (SNF) under simulated transportation environments using the Cyclic Integrated Reversible-Bending Fatigue Tester (CIRFT), the hot-cell testing technology developed at Oak Ridge National Laboratory (ORNL). The collected CIRFT data will be utilized to support ongoing spent fuel modeling activities, and support SNF transportation related licensing issues. Recent testing to understand the effects of hydride reorientation on SNF vibration integrity is also being evaluated. CIRFT results have provided insight into the fuel/clad system response to transportation related loads. The major findings of CIRFT on the HBU SNF are as follows: SNF system interface bonding plays an important role in SNF vibration performance, Fuel structure contributes to the SNF system stiffness, There are significant variations in stress and curvature of SNF systems during vibration cycles resulting from segment pellets and clad interaction, and SNF failure initiates at the pellet-pellet interface region and appears to be spontaneous. Because of the non-homogeneous composite structure of the SNF system, finite element analyses (FEA) are needed to translate the global moment-curvature measurement into local stress-strain profiles. The detailed mechanisms of the pellet-pellet and pellet-clad interactions and the stress concentration effects at the pellet-pellet interface cannot be readily obtained directly from a CIRFT system measurement. Therefore, detailed FEA is used to understand the global test response, and that data will also be presented.

  16. Pelletizing/reslurrying as a means of distributing and firing clean coal

    SciTech Connect

    Conkle, H.N.; Raghavan, J.K.; Smit, F.J.; Jha, M.C.

    1991-09-20

    The objective of this study is to develop technology that permits the practical and economic preparation, storage, handling, and transportation of coal pellets, which can be formulated into Coal-Water Fuels (CWFs) suitable for firing in small- and medium-size commercial and industrial boilers, furnaces, and engines.

  17. Micromorphology of pelletized soil conditioners

    NASA Astrophysics Data System (ADS)

    Hirsch, Florian; Dietrich, Nils; Knoop, Christine; Raab, Thomas

    2017-04-01

    Soil conditioners produced by anaerobic digestion and subsequent composting of organic household waste, bear the potential to improve unproductive farmland together with a reduced input risk of unwanted pollutants into the soils. Within the VeNGA project (http://www.biogas-network.de/venga), soil conditioners from anaerobically digested organic household waste are tested for their potential to increase plant growth in glasshouse and field experiments. Because the production techniques of these soil conditioners may influence their physical and chemical behaviour in the soil, two different techniques for pelletizing the soil conditioners where applied. We present findings from a pot experiment with cereal that has been sampled after two months for micromorphological analyses. We visualize the decomposition and the physical behaviour of the soil conditioners. Pellets produced in an agglomeration mixer result in dense balls, that are only slightly decomposed after the trial. But the soil conditioners created under pressure in a screw extruder are rich in voids and have the potential of retaining more soil water.

  18. Carbonation as a binding mechanism for coal/calcium hydroxide pellets. Technical report, September 1, 1991--November 30, 1991

    SciTech Connect

    Rapp, D.M.

    1991-12-31

    Current coal mining and processing procedures produce a significant quanity of fine coal that is difficult to handle and transport. The objective of this work is to determine if these fines can be economically pelletized with calcium hydroxide, a sulfur capturing sorbent, to produce a clean-burning fuel for fluidized-bed combustors or stoker boilers. To harden these pellets, carbonation, which is the reaction of calcium hydroxide with carbon dioxide to produce a cementitious matrix of calcium carbonate, is being investigated. Previous research indicated that carbonation significantly improved compressive strength, impact and attrition resistance and ``weatherproofed`` pellets formed with sufficient calcium hydroxide (5 to 10% for minus 28 mesh coal fines).

  19. Carbonation as a binding mechanism for coal/calcium hydroxide pellets. Final technical report, September 1, 1991--August 31, 1992

    SciTech Connect

    Rapp, D.M.; Lytle, J.M.; Hackley, K.C.; Strickland, R.; Berger, R.; Schanche, G.

    1992-12-31

    In this project, the ISGS is investigating the pelletization of fine coal with calcium hydroxide, a sulfur-capturing sorbent. The objective is to produce a readily-transportable fuel which will burn in compliance with the recently passed Clean Air Act Amendment (CAAA). To improve the economics of pelletizing, carbonation, or, the reaction of carbon dioxide with calcium hydroxide, which produces a binding matrix of calcium carbonate, is being investigated as a method of hardening pelletized coal fines. This year, pellets were produced from 28 {times} 0 coal fines collected from an Illinois preparation plant using a laboratory version of a California Pellet Mill (CPM), a commercially available pellet machine. The CPM effectively pelletized coal fines at the moisture content they were dewatered to at the plant. Carbonation nearly doubled the strength of pellets containing 10 wt % calcium hydroxide. Other results from this year`s work indicate that inclusion of calcium hydroxide into pellets resulted in chlorine capture of approximately 20 wt % for combustion tests conducted at both 850 and 1100{degrees}C. Arsenic emissions were reduced from near 38 wt% at 850 C to essentially nil with inclusion of 10 wt % calcium hydroxide into the pellets. At 110{degrees}C, arsenic emissions were reduced from about 90 wt % to about 15 wt %. Sodium emissions, however, increased with the addition of calcium hydroxide. At 850{degrees}C, sodium capture dropped from about 98 wt % to 73 wt % for pellets containing 10 wt % calcium hydroxide; at 1100{degrees}C, capture dropped from about 92 wt % to about 20 wt %.

  20. Particulate and gaseous emissions from the combustion of different biofuels in a pellet stove

    NASA Astrophysics Data System (ADS)

    Vicente, E. D.; Duarte, M. A.; Tarelho, L. A. C.; Nunes, T. F.; Amato, F.; Querol, X.; Colombi, C.; Gianelle, V.; Alves, C. A.

    2015-11-01

    Seven fuels (four types of wood pellets and three agro-fuels) were tested in an automatic pellet stove (9.5 kWth) in order to determine emission factors (EFs) of gaseous compounds, such as carbon monoxide (CO), methane (CH4), formaldehyde (HCHO), and total organic carbon (TOC). Particulate matter (PM10) EFs and the corresponding chemical compositions for each fuel were also obtained. Samples were analysed for organic carbon (OC) and elemental carbon (EC), anhydrosugars and 57 chemical elements. The fuel type clearly affected the gaseous and particulate emissions. The CO EFs ranged from 90.9 ± 19.3 (pellets type IV) to 1480 ± 125 mg MJ-1 (olive pit). Wood pellets presented the lowest TOC emission factor among all fuels. HCHO and CH4 EFs ranged from 1.01 ± 0.11 to 36.9 ± 6.3 mg MJ-1 and from 0.23 ± 0.03 to 28.7 ± 5.7 mg MJ-1, respectively. Olive pit was the fuel with highest emissions of these volatile organic compounds. The PM10 EFs ranged from 26.6 ± 3.14 to 169 ± 23.6 mg MJ-1. The lowest PM10 emission factor was found for wood pellets type I (fuel with low ash content), whist the highest was observed during the combustion of an agricultural fuel (olive pit). The OC content of PM10 ranged from 8 wt.% (pellets type III) to 29 wt.% (olive pit). Variable EC particle mass fractions, ranging from 3 wt.% (olive pit) to 47 wt.% (shell of pine nuts), were also observed. The carbonaceous content of particulate matter was lower than that reported previously during the combustion of several wood fuels in traditional woodstoves and fireplaces. Levoglucosan was the most abundant anhydrosugar, comprising 0.02-3.03 wt.% of the particle mass. Mannosan and galactosan were not detected in almost all samples. Elements represented 11-32 wt.% of the PM10 mass emitted, showing great variability depending on the type of biofuel used.

  1. Operation of the repeating pneumatic injector on TFTR and design of an 8-shot deuterium pellet injector

    SciTech Connect

    Combs, S.K.; Milora, S.L.; Foust, C.R.; Baylor, L.R.; Burris, R.D.; Fisher, P.W.; Lunsford, R.V.; Sparks, D.O.; Stewart, K.A.; Wysor, R.B.

    1985-01-01

    The repeating pneumatic hydrogen pellet injector, which was developed at the Oak Ridge National Laboratory (ORNL), has been installed and operated on the Tokamak Fusion Test Reactor (TFTR). The injector combines high-speed extruder and pneumatic acceleration technologies to propel frozen hydrogen isotope pellets repetitively at high speeds. The pellets are transported to the plasma in an injection line that also serves to minimize the gas loading on the torus; the injection line incorporates a fast shutter valve and two stages of guide tubes with intermediate vacuum pumping stations. A remote, stand-alone control and data acquisition system is used for injector and vacuum system operation. In early pellet fueling experiments on TFTR, the injector has been used to deliver deuterium pellets at speeds ranging from 1.0 to 1.5 km/s into plasma discharges. First, single large (nominal 4-mm-dia) pellets provided high densities in TFTR (1.8 x 10/sup 14/ cm/sup -3/ on axis); after conversion to smaller (nominal 2.7-mm-dia) pellets, up to five pellets were injected at 0.25-s intervals into a plasma discharge, giving a line-averaged density of 1 x 10/sup 14/ cm/sup -3/. Operating characteristics and performance of the injector in initial tests on TFTR are presented.

  2. Experiments on torrefied wood pellet: study by gasification and characterization for waste biomass to energy applications

    PubMed Central

    Rollinson, Andrew N.; Williams, Orla

    2016-01-01

    Samples of torrefied wood pellet produced by low-temperature microwave pyrolysis were tested through a series of experiments relevant to present and near future waste to energy conversion technologies. Operational performance was assessed using a modern small-scale downdraft gasifier. Owing to the pellet's shape and surface hardness, excellent flow characteristics were observed. The torrefied pellet had a high energy density, and although a beneficial property, this highlighted the present inflexibility of downdraft gasifiers in respect of feedstock tolerance due to the inability to contain very high temperatures inside the reactor during operation. Analyses indicated that the torrefaction process had not significantly altered inherent kinetic properties to a great extent; however, both activation energy and pre-exponential factor were slightly higher than virgin biomass from which the pellet was derived. Thermogravimetric analysis-derived reaction kinetics (CO2 gasification), bomb calorimetry, proximate and ultimate analyses, and the Bond Work Index grindability test provided a more comprehensive characterization of the torrefied pellet's suitability as a fuel for gasification and also other combustion applications. It exhibited significant improvements in grindability energy demand and particle size control compared to other non-treated and thermally treated biomass pellets, along with a high calorific value, and excellent resistance to water. PMID:27293776

  3. Cryogenic pellet launcher adapted for controlling of tokamak plasma edge instabilities.

    PubMed

    Lang, P T; Cierpka, P; Harhausen, J; Neuhauser, J; Wittmann, C; Gál, K; Kálvin, S; Kocsis, G; Sárközi, J; Szepesi, T; Dorner, C; Kauke, G

    2007-02-01

    One of the main challenges posed recently on pellet launcher systems in fusion-oriented plasma physics is the control of the plasma edge region. Strong energy bursts ejected from the plasma due to edge localized modes (ELMs) can form a severe threat for in-vessel components but can be mitigated by sufficiently frequent triggering of the underlying instabilities using hydrogen isotope pellet injection. However, pellet injection systems developed mainly for the task of ELM control, keeping the unwanted pellet fueling minimized, are still missing. Here, we report on a novel system developed under the premise of its suitability for control and mitigation of plasma edge instabilities. The system is based on the blower gun principle and is capable of combining high repetition rates up to 143 Hz with low pellet velocities. Thus, the flexibility of the accessible injection geometry can be maximized and the pellet size kept low. As a result the new system allows for an enhancement in the tokamak operation as well as for more sophisticated experiments investigating the underlying physics of the plasma edge instabilities. This article reports on the design of the new system, its main operational characteristics as determined in extensive test bed runs, and also its first test at the tokamak experiment ASDEX Upgrade.

  4. Experiments on torrefied wood pellet: study by gasification and characterization for waste biomass to energy applications.

    PubMed

    Rollinson, Andrew N; Williams, Orla

    2016-05-01

    Samples of torrefied wood pellet produced by low-temperature microwave pyrolysis were tested through a series of experiments relevant to present and near future waste to energy conversion technologies. Operational performance was assessed using a modern small-scale downdraft gasifier. Owing to the pellet's shape and surface hardness, excellent flow characteristics were observed. The torrefied pellet had a high energy density, and although a beneficial property, this highlighted the present inflexibility of downdraft gasifiers in respect of feedstock tolerance due to the inability to contain very high temperatures inside the reactor during operation. Analyses indicated that the torrefaction process had not significantly altered inherent kinetic properties to a great extent; however, both activation energy and pre-exponential factor were slightly higher than virgin biomass from which the pellet was derived. Thermogravimetric analysis-derived reaction kinetics (CO2 gasification), bomb calorimetry, proximate and ultimate analyses, and the Bond Work Index grindability test provided a more comprehensive characterization of the torrefied pellet's suitability as a fuel for gasification and also other combustion applications. It exhibited significant improvements in grindability energy demand and particle size control compared to other non-treated and thermally treated biomass pellets, along with a high calorific value, and excellent resistance to water.

  5. Experiments on torrefied wood pellet: study by gasification and characterization for waste biomass to energy applications

    NASA Astrophysics Data System (ADS)

    Rollinson, Andrew N.; Williams, Orla

    2016-05-01

    Samples of torrefied wood pellet produced by low-temperature microwave pyrolysis were tested through a series of experiments relevant to present and near future waste to energy conversion technologies. Operational performance was assessed using a modern small-scale downdraft gasifier. Owing to the pellet's shape and surface hardness, excellent flow characteristics were observed. The torrefied pellet had a high energy density, and although a beneficial property, this highlighted the present inflexibility of downdraft gasifiers in respect of feedstock tolerance due to the inability to contain very high temperatures inside the reactor during operation. Analyses indicated that the torrefaction process had not significantly altered inherent kinetic properties to a great extent; however, both activation energy and pre-exponential factor were slightly higher than virgin biomass from which the pellet was derived. Thermogravimetric analysis-derived reaction kinetics (CO2 gasification), bomb calorimetry, proximate and ultimate analyses, and the Bond Work Index grindability test provided a more comprehensive characterization of the torrefied pellet's suitability as a fuel for gasification and also other combustion applications. It exhibited significant improvements in grindability energy demand and particle size control compared to other non-treated and thermally treated biomass pellets, along with a high calorific value, and excellent resistance to water.

  6. A Bichromator for High Time Resolution Measurements of Stark Broadened Pellet Ablation Light

    NASA Astrophysics Data System (ADS)

    Schmidt, G. L.; Baylor, L. R.; Fehling, D. T.; Jernigan, T. C.; Brooks, N. H.; Parks, P. B.

    2004-11-01

    Details of the pellet/plasma interaction are important for modeling of local pellet source rates and cross field transport of pellet mass. Understanding these processes is critical for projection of current fueling experiments to future devices such as ITER. Measurement of the Stark broadened deuterium emission lines provides the electron density and temperature of the pellet cloud for comparison with modeling details. Stark broadening measurements on JET for low field launch pellets at moderate time resolution indicate a slow variation in the cloud parameters. Observations of ablation light suggest changes in cloud parameters may occur on faster time scales. We report on the possible application of a multiple interference filter technique[1]to allow monitoring of cloud parameters at time resolution sufficient to study both the slow and rapid variations in cloud parameters. Application of the bichromator to line widths and temporal evolution typical of DIII-D pellet injection cases will be discussed.[1]McNeill,D.H.,RSI 73 (2002) 3193.

  7. Combustion Gases And Heat Release Analysis During Flame And Flameless Combustion Of Wood Pellets

    NASA Astrophysics Data System (ADS)

    Horváth, Jozef; Wachter, Igor; Balog, Karol

    2015-06-01

    With the growing prices of fossil fuels, alternative fuels produced of biomass come to the fore. They are made of waste materials derived from the processing of wood and wood materials. The main objective of this study was to analyse the fire-technical characteristics of wood pellets. The study analysed three dust samples acquired from wood pellets made of various types of wood biomass. Wood pellet dust is produced when manipulating with pellets. During this process a potentially hazardous situations may occur. Biomass is chemically composed mostly of hemicellulose, cellulose and lignin. During straining of the biomass by heat flux, combustion initiation occurs. Also, there was a change in the composition of material throughout combustion gases production, and the amount of heat generated by a flame or flameless combustion. Measurement of fire characteristics was conducted according to ISO 5660-1 standard using a cone calorimeter. Two samples of wood pellet dust were tested under the heat flux of 35 kW.m-2 and 50 kW.m-2. The process of combustion, the time to ignition, the carbon monoxide concentration and the amount of released heat were observed.

  8. Estimating shot distance from limited pellets pattern.

    PubMed

    Plebe, Alessio; Compagnini, Domenico

    2012-10-10

    Several methods are available for shooting range estimation based on pellets pattern on the target that have a remarkable degree of accuracy. The task is usually approached working under the assumption that the entire distribution of pellets is available for examination. These methods fail, however, when the victim has been hit by a portion of the pattern only. The problem can be solved with reasonable accuracy when there are areas of void in the victim that are adjacent to the area struck by pellets. This study presents a method that can be used in precisely this type of situation, allowing the estimation of shot distance in cases of partial pellet patterns. It is based on collecting distributions in test shots at several distances, and taking samples in the targets, constrained by the shape of the void and the pellet hit areas. Statistical descriptors of patterns are extracted from such samples, and fed into a neural network classifier, estimating shot ranges of distance.

  9. Plasma fuelling with cryogenic pellets in the stellarator TJ-II

    NASA Astrophysics Data System (ADS)

    McCarthy, K. J.; Panadero, N.; Velasco, J. L.; Combs, S. K.; Caughman, J. B. O.; Fontdecaba, J. M.; Foust, C.; García, R.; Hernández Sánchez, J.; Navarro, M.; Pastor, I.; Soleto, A.; the TJ-II Team

    2017-05-01

    Cryogenic pellet injection is a widely used technique for delivering fuel to the core of magnetically confined plasmas. Indeed, such systems are currently functioning on many tokamak, reversed field pinch and stellarator devices. A pipe-gun-type pellet injector is now operated on the TJ-II, a low-magnetic shear stellarator of the heliac type. Cryogenic hydrogen pellets, containing between 3  ×  1018 and 4  ×  1019 atoms, are injected at velocities between 800 and 1200 m s-1 from its low-field side into plasmas created and/or maintained in this device by electron cyclotron resonance and/or neutral beam injection heating. In this paper, the first systematic study of pellet ablation, particle deposition and fuelling efficiency is presented for TJ-II. From this, light-emission profiles from ablating pellets are found to be in reasonable agreement with simulated pellet ablation profiles (created using a neutral gas shielding-based code) for both heating scenarios. In addition, radial offsets between recorded light-emission profiles and particle deposition profiles provide evidence for rapid outward drifting of ablated material that leads to pellet particle loss from the plasma. Finally, fuelling efficiencies are documented for a range of target plasma densities (~4  ×  1018-  ~2  ×  1019 m-3). These range from ~20%-  ~85% and are determined to be sensitive to pellet penetration depth. Additional observations, such as enhanced core ablation, are discussed and planned future work is outlined.

  10. Fabrication, Inspection, and Test Plan for the Advanced Test Reactor (ATR) High-Power Mixed-Oxide (MOX) Fuel Irradiation Project

    SciTech Connect

    Wachs, G. W.

    1998-09-01

    The Department of Energy (DOE) Fissile Disposition Program (FMDP) has announced that reactor irradiation of Mixed-Oxide (MOX) fuel is one of the preferred alternatives for disposal of surplus weapons-usable plutonium (Pu). MOX fuel has been utilized domestically in test reactors and on an experimental basis in a number of Commercial Light Water Reactors (CLWRs). Most of this experience has been with Pu derived from spent low enriched uranium (LEU) fuel, known as reactor grade (RG) Pu. The High-Power MOX fuel test will be irradiated in the Advanced Test Reactor (ATR) to provide preliminary data to demonstrate that the unique properties of surplus weapons-derived or weapons-grade (WG) plutonium (Pu) do not compromise the applicability of this MOX experience base. The purpose of the high-power experiment, in conjunction with the currently ongoing average-power experiment at the ATR, is to contribute new information concerning the response of WG plutonium under more severe irradiation conditions typical of the peak power locations in commercial reactors. In addition, the high-power test will contribute experience with irradiation of gallium-containing fuel to the database required for resolution of generic CLWR fuel design issues. The distinction between "high-power" and "average-power" relates to the position within the nominal CLWR core. The high-power test project is subject to a number of requirements, as discussed in the Fissile Materials Disposition Program Light Water Reactor Mixed Oxide Fuel Irradiation High-Power Test Project Plan (ORNL/MD/LTR-125).

  11. Bilateral shotgun pellet pulmonary emboli

    PubMed Central

    Huebner, Stephen; Ali, Sayed

    2012-01-01

    Intravascular migration of bullets and other foreign bodies is a rare but known complication of penetrating trauma. Missile embolization can represent a diagnostic challenge because it may present in various and unexpected ways. We present the case of a 54-year-old female who sustained shotgun pellet emboli to the pulmonary arteries following a left upper extremity gunshot wound and related vascular surgery. The case illustrates bilateral embolization, and the embolic events occurred following surgery. Embolization should be considered in evaluating patients with gunshot wounds, particularly if there are anomalous symptoms or the projectile is not found in the original, or expected, location. Close attention to the location of the foreign bodies on serial radiographs may reveal the diagnosis of intravascular embolization. PMID:22690290

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

    SciTech Connect

    Fuketa, Toyoshi; Ishijima, Kiyomi; Mori, Yukihide

    1996-03-01

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

  13. Nuclear fuel element

    DOEpatents

    Meadowcroft, Ronald Ross; Bain, Alastair Stewart

    1977-01-01

    A nuclear fuel element wherein a tubular cladding of zirconium or a zirconium alloy has a fission gas plenum chamber which is held against collapse by the loops of a spacer in the form of a tube which has been deformed inwardly at three equally spaced, circumferential positions to provide three loops. A heat resistant disc of, say, graphite separates nuclear fuel pellets within the cladding from the plenum chamber. The spacer is of zirconium or a zirconium alloy.

  14. Steam reforming of n-hexane on pellet and monolithic catalyst beds. A comparative study on improvements due to heat transfer

    NASA Astrophysics Data System (ADS)

    1981-10-01

    Monolithic catalysts with higher available active surface areas and better thermal conductivity than conventional pellets beds, making possible the steam reforming of fuels heavier than naphtha, were examined. Performance comparisons were made between conventional pellet beds and honeycomb monolith catalysts using n-hexane as the fuel. Metal-supported monoliths were examined. These offer higher structural stability and higher thermal conductivity than ceramic supports. Data from two metal monoliths of different nickel catalyst loadings were compared to pellets under the same operating conditions. Improved heat transfer and better conversion efficiencies were obtained with the monolith having higher catalyst loading. Surface-gas interaction was observed throughout the length of the monoliths.

  15. Steam reforming of n-hexane on pellet and monolithic catalyst beds. A comparative study on improvements due to heat transfer

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Monolithic catalysts with higher available active surface areas and better thermal conductivity than conventional pellets beds, making possible the steam reforming of fuels heavier than naphtha, were examined. Performance comparisons were made between conventional pellet beds and honeycomb monolith catalysts using n-hexane as the fuel. Metal-supported monoliths were examined. These offer higher structural stability and higher thermal conductivity than ceramic supports. Data from two metal monoliths of different nickel catalyst loadings were compared to pellets under the same operating conditions. Improved heat transfer and better conversion efficiencies were obtained with the monolith having higher catalyst loading. Surface-gas interaction was observed throughout the length of the monoliths.

  16. Steam reforming of n-hexane on pellet and monolithic catalyst beds. A comparative study on improvements due to heat transfer

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Monolithic catalysts with higher available active surface areas and better thermal conductivity than conventional pellets beds, making possible the steam reforming of fuels heavier than naphtha, were examined. Performance comparisons were made between conventional pellet beds and honeycomb monolith catalysts using n-hexane as the fuel. Metal-supported monoliths were examined. These offer higher structural stability and higher thermal conductivity than ceramic supports. Data from two metal monoliths of different nickel catalyst loadings were compared to pellets under the same operating conditions. Improved heat transfer and better conversion efficiencies were obtained with the monolith having higher catalyst loading. Surface-gas interaction was observed throughout the length of the monoliths.

  17. Ofsted Inspected

    ERIC Educational Resources Information Center

    Coffield, Frank

    2009-01-01

    One of the most radical actions one can take is to describe, without exaggeration or bias, exactly what is happening. The author has been reading the "Handbook for the inspection of further education and skills from September 2009." The Office for Standards in Education, Children's Services and Skills' (Ofsted's) new handbook promises a "fresh…

  18. OSHA Inspections

    DTIC Science & Technology

    2000-01-01

    Under the Occupational Safety and Health Act of 1970 (the Act), the Occupational Safety and Health Administration (OSHA) is authorized to conduct... occupational safety and health field and who are trained in OSHA standards and in the recognition of safety and health hazards. Similarly, states with...their own occupational safety and health programs conduct inspection using qualified state compliance safety and health officers.

  19. Portable instrument for inspecting irradiated nuclear-fuel assemblies in a water-filled storage pond by measurement of induced Cerenkov radiation

    DOEpatents

    Nicholson, N.; Dowdy, E.J.; Holt, D.M.; Stump, C.J. Jr.

    1982-05-13

    A portable instrument for measuring induced Cerenkov radiation associated with irradiated nuclear fuel assemblies in a water-filled storage pond is disclosed. The instrument includes a photomultiplier tube and an image intensifier which are operable in parallel and simultaneously by means of a field lens assembly and an associated beam splitter. The image intensifier permits an operator to aim and focus the apparatus on a submerged fuel assembly. Once the instrument is aimed and focused, an illumination reading can be obtained with the photomultiplier tube. The instrument includes a lens cap with a carbon-14/phosphor light source for calibrating the apparatus in the field.

  20. Short Communication: Emission of Oxygenated Polycyclic Aromatic Hydrocarbons from Biomass Pellet Burning in a Modern Burner for Cooking in China

    PubMed Central

    Shen, Guofeng; Wei, Siye; Zhang, Yanyan; Wang, Rong; Wang, Bin; Li, Wei; Shen, Huizhong; Huang, Ye; Chen, Yuanchen; Chen, Han; Wei, Wen; Tao, Shu

    2015-01-01

    Biomass pellets are undergoing fast deployment widely in the world, including China. To this stage, there were limited studies on the emissions of various organic pollutants from the burning of those pellets. In addition to parent polycyclic aromatic hydrocarbons, oxygenated PAHs (oPAHs) have been received increased concerns. In this study, emission factors of oPAHs (EFoPAHs) were measured for two types of pellets made from corn straw and pine wood, respectively. Two combustion modes with (mode II) and without (mode I) secondary side air supply in a modern pellet burner were investigated. For the purpose of comparison, EFoPAHs for raw fuels combusted in a traditional cooking stove were also measured. EFoPAHs were 348±305 and 396±387 µg/kg in the combustion mode II for pine wood and corn straw pellets, respectively. In mode I, measured EFoPAHs were 77.7±49.4 and 189±118 µg/kg, respectively. EFs in mode II were higher (2–5 times) than those in mode I mainly due to the decreased combustion temperature under more excess air. Compared to EFoPAHs for raw corn straw and pine wood burned in a traditional cooking stove, total EFoPAHs for the pellets in mode I were significantly lower (p < 0.05), likely due to increased combustion efficiencies and change in fuel properties. However, the difference between raw biomass fuels and the pellets burned in mode II was not statistically significant. Taking both the increased thermal efficiencies and decreased EFs into consideration, substantial reduction in oPAH emission can be expected if the biomass pellets can be extensively used by rural residents. PMID:25678836

  1. 46 CFR 122.726 - Annual inspections.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... emptying and cleaning of each fuel tank, and refilling it with fresh fuel. (b) Each davit, winch, fall and... inspection and repair if the expiration date has passed. (d) Each battery used in an item of lifesaving... expiration date of the battery has passed. The expiration date of the battery may be marked on the battery...

  2. Study of fueling requirements for the Engineering Test Reactor

    SciTech Connect

    Ho, S.K.; Perkins, L.J.

    1987-10-16

    An assessment of the fueling requirement for the TIBER Engineering Test Reactor is studied. The neutral shielding pellet ablation model with the inclusion of the effects of the alpha particles is used for our study. The high electron temperature in a reactor-grade plasma makes pellet penetration very difficult. The launch length has to be very large (several tens of meters) in order to avoid pellet breakage due to the low inertial strength of DT ''ice.'' The minimum repetition rate corresponding to the largest allowable pellet, is found to be about 1 Hz. A brief survey is done on the various operational and conceptual pellet injection schemes for plasma fueling. The underlying conclusion is that an alternative fueling scheme of coaxial compact-toroid plasma gun is very likely needed for effective central fueling of reactor-grade plasmas. 16 refs.

  3. A centrifuge CO2 pellet cleaning system

    NASA Astrophysics Data System (ADS)

    Foster, C. A.; Fisher, P. W.; Nelson, W. D.; Schechter, D. E.

    1995-03-01

    An advanced turbine/CO2 pellet accelerator is being evaluated as a depaint technology at Oak Ridge National Laboratory (ORNL). The program, sponsored by Warner Robins Air Logistics Center (ALC), Robins Air Force Base, Georgia, has developed a robot-compatible apparatus that efficiently accelerates pellets of dry ice with a high-speed rotating wheel. In comparison to the more conventional compressed air 'sandblast' pellet accelerators, the turbine system can achieve higher pellet speeds, has precise speed control, and is more than ten times as efficient. A preliminary study of the apparatus as a depaint technology has been undertaken. Depaint rates of military epoxy/urethane paint systems on 2024 and 7075 aluminum panels as a function of pellet speed and throughput have been measured. In addition, methods of enhancing the strip rate by combining infra-red heat lamps with pellet blasting and by combining the use of environmentally benign solvents with the pellet blasting have also been studied. The design and operation of the apparatus will be discussed along with data obtained from the depaint studies.

  4. A centrifuge CO2 pellet cleaning system

    NASA Technical Reports Server (NTRS)

    Foster, C. A.; Fisher, P. W.; Nelson, W. D.; Schechter, D. E.

    1995-01-01

    An advanced turbine/CO2 pellet accelerator is being evaluated as a depaint technology at Oak Ridge National Laboratory (ORNL). The program, sponsored by Warner Robins Air Logistics Center (ALC), Robins Air Force Base, Georgia, has developed a robot-compatible apparatus that efficiently accelerates pellets of dry ice with a high-speed rotating wheel. In comparison to the more conventional compressed air 'sandblast' pellet accelerators, the turbine system can achieve higher pellet speeds, has precise speed control, and is more than ten times as efficient. A preliminary study of the apparatus as a depaint technology has been undertaken. Depaint rates of military epoxy/urethane paint systems on 2024 and 7075 aluminum panels as a function of pellet speed and throughput have been measured. In addition, methods of enhancing the strip rate by combining infra-red heat lamps with pellet blasting and by combining the use of environmentally benign solvents with the pellet blasting have also been studied. The design and operation of the apparatus will be discussed along with data obtained from the depaint studies.

  5. A Review of Pellets from Different Sources

    PubMed Central

    Miranda, Teresa; Montero, Irene; Sepúlveda, Francisco José; Arranz, José Ignacio; Rojas, Carmen Victoria; Nogales, Sergio

    2015-01-01

    The rise in pellet consumption has resulted in a wider variety of materials for pellet manufacture. Thus, pellet industry has started looking for alternative products, such as wastes from agricultural activities, forestry and related industries, along with the combination thereof, obtaining a broad range of these products. In addition, the entry into force of EN ISO 17225 standard makes wood pellet market (among other types) possible for industry and household purposes. Therefore, wastes that are suitable for biomass use have recently increased. In this study, the main characteristics of ten kinds of laboratory-made pellets from different raw materials were analyzed. Thus, we have focused on the most limiting factors of quality standards that determine the suitability for biomass market, depending on the kind of pellet. The results showed considerable differences among the analyzed pellets, exceeding the limits established by the standard in almost all cases, especially concerning ash content and N and S composition. The requirements of the studied standard, very demanding for certain factors, disable the entry of these densified wastes in greater added value markets. PMID:28788009

  6. A Review of Pellets from Different Sources.

    PubMed

    Miranda, Teresa; Montero, Irene; Sepúlveda, Francisco José; Arranz, José Ignacio; Rojas, Carmen Victoria; Nogales, Sergio

    2015-03-27

    The rise in pellet consumption has resulted in a wider variety of materials for pellet manufacture. Thus, pellet industry has started looking for alternative products, such as wastes from agricultural activities, forestry and related industries, along with the combination thereof, obtaining a broad range of these products. In addition, the entry into force of EN ISO 17225 standard makes wood pellet market (among other types) possible for industry and household purposes. Therefore, wastes that are suitable for biomass use have recently increased. In this study, the main characteristics of ten kinds of laboratory-made pellets from different raw materials were analyzed. Thus, we have focused on the most limiting factors of quality standards that determine the suitability for biomass market, depending on the kind of pellet. The results showed considerable differences among the analyzed pellets, exceeding the limits established by the standard in almost all cases, especially concerning ash content and N and S composition. The requirements of the studied standard, very demanding for certain factors, disable the entry of these densified wastes in greater added value markets.

  7. Microbiological survey of birds of prey pellets.

    PubMed

    Dipineto, Ludovico; Bossa, Luigi Maria De Luca; Pace, Antonino; Russo, Tamara Pasqualina; Gargiulo, Antonio; Ciccarelli, Francesca; Raia, Pasquale; Caputo, Vincenzo; Fioretti, Alessandro

    2015-08-01

    A microbiological survey of 73 pellets collected from different birds of prey species housed at the Wildlife Rescue and Rehabilitation Center of Napoli (southern Italy) was performed. Pellets were analyzed by culture and biochemical methods as well as by serotyping and polymerase chain reaction. We isolated a wide range of bacteria some of them also pathogens for humans (i.e. Salmonella enterica serotype Typhimurium, Campylobacter coli, Escherichia coli O serogroups). This study highlights the potential role of birds of prey as asymptomatic carriers of pathogenic bacteria which could be disseminated in the environment not only through the birds of prey feces but also through their pellets.

  8. FUEL ELEMENT FOR NUCLEAR REACTORS

    DOEpatents

    Bassett, C.H.

    1961-05-16

    A fuel element particularly adapted for use in nuclear reactors of high power density is offered. It has fissionable fuel pellet segments mounted in a tubular housing and defining a central passage in the fuel element. A burnable poison element extends through the central passage, which is designed to contain more poison material at the median portion than at the end portions thereby providing a more uniform hurnup and longer reactivity life.

  9. Synthesis of dense yttrium-stabilised hafnia pellets for nuclear applications by spark plasma sintering

    NASA Astrophysics Data System (ADS)

    Tyrpekl, Vaclav; Holzhäuser, Michael; Hein, Herwin; Vigier, Jean-Francois; Somers, Joseph; Svora, Petr

    2014-11-01

    Dense yttrium-stabilised hafnia pellets (91.35 wt.% HfO2 and 8.65 wt.% Y2O3) were prepared by spark plasma sintering consolidation of micro-beads synthesised by the “external gelation” sol-gel technique. This technique allows a preparation of HfO2-Y2O3 beads with homogenous yttria-hafnia solid solution. A sintering time of 5 min at 1600 °C was sufficient to produce high density pellets (over 90% of the theoretical density) with significant reproducibility. The pellets have been machined in a lathe to the correct dimensions for use as neutron absorbers in an experimental test irradiation in the High Flux Reactor (HFR) in Petten, Holland, in order to investigate the safety of americium based nuclear fuels.

  10. The Ignitor Fast Pellet Injector

    NASA Astrophysics Data System (ADS)

    Frattolillo, A.; Migliori, S.; Bombarda, F.; Milora, S. L.; Baylor, L. R.; Combs, S. K.

    2004-11-01

    A collaboration between the ENEA Laboratory at Frascati and the Fusion Technology Group of Oak Ridge for the development of a fast pellet injector for the Ignitor ignition experiment has been established. The program aims at the construction of a 4 barrel, double stage gun able to reach speeds up to 4 km/s and thus penetrate to the core of the plasma column. The compact size of the Ignitor machine favors the injection from the low field side, for which very positive results have been obtained on the FTU machine [1], in terms of density profile peaking and good energy confinement. The ongoing activities include the procurement of all the hardware for the criocooler, diagnostics and control electronics, from the ORNL side, and the design and construction of the gun by ENEA. A new fast valve has been developed that considerably reduces the requirements on the expansion volumes necessary to prevent the propulsion gas to reach the plasma chamber. [1] D. Frigione, et al., Nuclear Fusion 41, 1613 (2001).

  11. Hydrogen Uptake of DPB Getter Pellets

    SciTech Connect

    Dinh, L N; Schildbach, M A; Herberg, J L; Saab, A P; Weigle, J; Chinn, S C; Maxwell, R S; McLean II, W

    2008-05-30

    The physical and chemical properties of 1,4-diphenylbutadiyne (DPB) blended with carbon-supported Pd (DPB-Pd/C) in the form of pellets during hydrogenation were investigated. A thermogravimetric analyzer (TGA) was employed to measure the kinetics of the hydrogen uptake by the DPB getter pellets. The kinetics obtained were then used to develop a semi-empirical model, based on gas diffusion into solids, to predict the performance of the getter pellets under various conditions. The accuracy of the prediction model was established by comparing the prediction models with independent experimental data on hydrogen pressure buildup in sealed systems containing DPB getter pellets and subjected to known rates of hydrogen input. The volatility of the hydrogenated DPB products and its effects on the hydrogen uptake kinetics were also analyzed.

  12. Plasma gun pellet acceleration modeling and experiment

    SciTech Connect

    Kincaid, R.W.; Bourham, M.A.; Gilligan, J.G.

    1996-12-31

    Modifications to the electrothermal plasma gun SIRENS have been completed to allow for acceleration experiments using plastic pellets. Modifications have been implemented to the 1-D, time dependent code ODIN to include pellet friction, momentum, and kinetic energy with options of variable barrel length. The code results in the new version, POSEIDON, compare favorably with experimental data and with code results from ODIN. Predicted values show an increased pellet velocity along the barrel length, achieving 2 km/s exit velocity. Measured velocity, at three locations along the barrel length, showed good correlation with predicted values. The code has also been used to investigate the effectiveness of longer pulse length on pellet velocity using simulated ramp up and down currents with flat top, and triangular current pulses with early and late peaking. 16 refs., 5 figs.

  13. Tritium recovery from lithium oxide pellets

    SciTech Connect

    Bertone, P.C.; Jassby, D.L.

    1984-01-01

    The TFTR Lithium Blanket Module is an assembly containing 650 kg of lithium oxide that will be used to test the ability of neutronics codes to model the tritium breeding characteristics of limited-coverage breeding zones in a tokamak. It is required that tritium concentrations as low as 0.1 nCi/g bred in both metallic lithium samples and lithium oxide pellets be measured with an uncertainty not exceeding +- 6%. A tritium assay technique for the metallic samples which meets this criterion has been developed. Two assay techniques for the lithium oxide pellets are being investigated. In one, the pellets are heated in a flowing stream of hydrogen, while in the other, the pellets are dissolved in 12 M hydrochloric acid.

  14. The effect of polycarbophil on the gastric emptying of pellets.

    PubMed

    Khosla, R; Davis, S S

    1987-01-01

    The influence of the putative bioadhesive, polycarbophil, on the gastric emptying of a pellet formulation, has been investigated in three fasted subjects. The pellets were radiolabelled with technetium-99m. Gastric emptying was measured using the technique of gamma scintigraphy. The pellets emptied from the stomach rapidly and in an exponential manner. Polycarbophil did not retard the gastric emptying of the pellets.

  15. Ciliates expel environmental Legionella-laden pellets to stockpile food.

    PubMed

    Hojo, Fuhito; Sato, Daisuke; Matsuo, Junji; Miyake, Masaki; Nakamura, Shinji; Kunichika, Miyuki; Hayashi, Yasuhiro; Yoshida, Mitsutaka; Takahashi, Kaori; Takemura, Hiromu; Kamiya, Shigeru; Yamaguchi, Hiroyuki

    2012-08-01

    When Tetrahymena ciliates are cultured with Legionella pneumophila, the ciliates expel bacteria packaged in free spherical pellets. Why the ciliates expel these pellets remains unclear. Hence, we determined the optimal conditions for pellet expulsion and assessed whether pellet expulsion contributes to the maintenance of growth and the survival of ciliates. When incubated with environmental L. pneumophila, the ciliates expelled the pellets maximally at 2 days after infection. Heat-killed bacteria failed to produce pellets from ciliates, and there was no obvious difference in pellet production among the ciliates or bacterial strains. Morphological studies assessing lipid accumulation showed that pellets contained tightly packed bacteria with rapid lipid accumulation and were composed of the layers of membranes; bacterial culturability in the pellets rapidly decreased, in contrast to what was seen in ciliate-free culture, although the bacteria maintained membrane integrity in the pellets. Furthermore, ciliates newly cultured with pellets were maintained and grew vigorously compared with those without pellets. In contrast, a human L. pneumophila isolate killed ciliates 7 days postinfection in a Dot/Icm-dependent manner, and pellets harboring this strain did not support ciliate growth. Also, pellets harboring the human isolate were resuscitated by coculturing with amoebae, depending on Dot/Icm expression. Thus, while ciliates expel pellet-packaged environmental L. pneumophila for stockpiling food, the pellets packaging the human isolate are harmful to ciliate survival, which may be of clinical significance.

  16. Single pellet crush strength testing of catalysts

    SciTech Connect

    Brienza, P.K. )

    1988-09-01

    ASTM D-32 Committee on Catalysts has developed a standard test method for single pellet crush strength for formed catalyst shapes. This standard was issued under the fixed designation D 4179. The method is applicable to regular catalyst shapes such as tablets and spheres. Extrudates, granular materials, and other irregular shapes are excluded. The committee continues to work on the development of a method for the single pellet crush testing of extrudates.

  17. Fueling of magnetic-confinement devices

    SciTech Connect

    Milora, S.L.

    1981-01-01

    A general overview of the fueling of magnetic confinement devices is presented, with particular emphasis on recent experimental results. Various practical fueling mechanisms are considered, such as cold gas inlet (or plasma edge fueling), neutral beam injection, and injection of high speed cryogenic hydrogen pellets. The central role played by charged particle transport and recycle of plasma particles from material surfaces in contact with the plasma is discussed briefly. The various aspects of hydrogen pellet injection are treated in detail, including applications to the production of high purity startup plasmas for stellarators and other devices, refueling of tokamak plasmas, pellet ablation theory, and the technology and performance characteristics of low and high speed pellet injectors.

  18. Chemical methods in the development of eco-efficient wood-based pellet production and technology.

    PubMed

    Kuokkanen, Matti; Kuokkanen, Toivo; Stoor, Tuomas; Niinimäki, Jouko; Pohjonen, Veli

    2009-09-01

    Up to 20 million tons of waste wood biomass per year is left unused in Finland, mainly in the forests during forestry operations, because supply and demand does not meet. As a consequence of high heat energy prices, the looming threat of climate change, the greenhouse effect, and due to global as well as national demands to considerably increase the proportion of renewable energy, there is currently tremendous enthusiasm in Finland to substantially increase pellet production. As part of this European objective to increase the eco- and cost-efficient utilization of bio-energy from the European forest belt, the aim of our research group is - by means of multidisciplinary research, especially through chemical methods - to promote the development of Nordic wood-based pellet production in both the qualitative and the quantitative sense. Wood-based pellets are classified as an emission-neutral fuel, which means that they are free from emission trading in the European Union. The main fields of pellet research and the chemical toolbox that has been developed for these studies, which includes a new specific staining and optical microscope method designed to determine the cross-linking of pellets in the presence of various binding compounds, are described in this paper. As model examples illustrating the benefits of this toolbox, experimental data is presented concerning Finnish wood pellets and corresponding wood-based pellets that include the use of starch-containing waste potato peel residue and commercial lignosulfonate as binding materials. The initial results concerning the use of the developed and optimized specific staining and microscopic method using starch-containing potato peel residue as binding material are presented.

  19. An economical and market analysis of Canadian wood pellets.

    SciTech Connect

    Peng, J.

    2010-08-01

    This study systematically examined the current and future wood pellet market, estimated the cost of Canadian torrefied pellets, and compared the torrefied pellets with the conventional pellets based on literature and industrial data. The results showed that the wood pellet industry has been gaining significant momentum due to the European bioenergy incentives and the rising oil and natural gas prices. With the new bioenergy incentives in USA, the future pellets market may shift to North America, and Canada can potentially become the largest pellet production centre, supported by the abundant wood residues and mountain pine beetle (MPB) infested trees.

  20. Gas adsorption capacity of wood pellets

    DOE PAGES

    Yazdanpanah, F.; Sokhansanj, Shahabaddine; Lim, C. Jim; ...

    2016-02-03

    In this paper, temperature-programmed desorption (TPD) analysis was used to measure and analyze the adsorption of off-gases and oxygen by wood pellets during storage. Such information on how these gases interact with the material helps in the understanding of the purging/stripping behavior of off-gases to develop effective ventilation strategies for wood pellets. Steam-exploded pellets showed the lowest carbon dioxide (CO2) uptake compared to the regular and torrefied pellets. The high CO2 adsorption capacity of the torrefied pellets could be attributed to their porous structure and therefore greater available surface area. Quantifying the uptake of carbon monoxide by pellets was challengingmore » due to chemical adsorption, which formed a strong bond between the material and carbon monoxide. The estimated energy of desorption for CO (97.8 kJ/mol) was very high relative to that for CO2 (7.24 kJ/mol), demonstrating the mechanism of chemical adsorption and physical adsorption for CO and CO2, respectively. As for oxygen, the strong bonds that formed between the material and oxygen verified the existence of chemical adsorption and formation of an intermediate material.« less

  1. [Pellet guns: a persistent threat to eyes].

    PubMed

    Assaf, E; Emadisson, H; Bendeddouche, K; Forestier, F; Salvanet-Bouccara, A

    2003-11-01

    Following a recent case of bilateral perforating ocular trauma by multiple pellets, the authors reviewed pellet traumatisms treated in the Emergency Department and operated on in the Ophthalmology Department of the Villeneuve-St-Georges Hospital over the past 15 years. At close range, pellet weapon shootings can generate lid, conjunctiva, and powder cornea tattoos; in these cases, the lesions are often unilateral. Shooting at longer range does not result in corneodermic tattoos, but because pellets scatter, binocular lesions frequently occur. The different lesions caused by these nonmagnetic foreign bodies are often very serious. An early, even very early, traumatic cataract is sometimes very difficult to treat in these polytraumatized eyes. The visual prognosis is more reserved, as the impact zones often involve the posterior pole and the macular area. The best recovered visual acuity is 30-35/20, with visual field alterations, but the injury to the eyeball by multiple pellets can generate globe atrophy. The authors stress the gravity of these ocular traumas, fortunately rarer but not completely eradicated since the law of May 6, 1995, which restricted the possession of these pellet guns.

  2. Gas adsorption capacity of wood pellets

    SciTech Connect

    Yazdanpanah, F.; Sokhansanj, Shahabaddine; Lim, C. Jim; Lau, A.; Bi, X. T.

    2016-02-03

    In this paper, temperature-programmed desorption (TPD) analysis was used to measure and analyze the adsorption of off-gases and oxygen by wood pellets during storage. Such information on how these gases interact with the material helps in the understanding of the purging/stripping behavior of off-gases to develop effective ventilation strategies for wood pellets. Steam-exploded pellets showed the lowest carbon dioxide (CO2) uptake compared to the regular and torrefied pellets. The high CO2 adsorption capacity of the torrefied pellets could be attributed to their porous structure and therefore greater available surface area. Quantifying the uptake of carbon monoxide by pellets was challenging due to chemical adsorption, which formed a strong bond between the material and carbon monoxide. The estimated energy of desorption for CO (97.8 kJ/mol) was very high relative to that for CO2 (7.24 kJ/mol), demonstrating the mechanism of chemical adsorption and physical adsorption for CO and CO2, respectively. As for oxygen, the strong bonds that formed between the material and oxygen verified the existence of chemical adsorption and formation of an intermediate material.

  3. LMFBR fuel assembly design for HCDA fuel dispersal

    DOEpatents

    Lacko, Robert E.; Tilbrook, Roger W.

    1984-01-01

    A fuel assembly for a liquid metal fast breeder reactor having an upper axial blanket region disposed in a plurality of zones within the fuel assembly. The characterization of a zone is dependent on the height of the axial blanket region with respect to the active fuel region. The net effect of having a plurality of zones is to establish a dispersal flow path for the molten materials resulting during a core meltdown accident. Upward flowing molten material can escape from the core region and/or fuel assembly without solidifying on the surface of fuel rods due to the heat sink represented by blanket region pellets.

  4. Post irradiation examination of thermal reactor fuels

    NASA Astrophysics Data System (ADS)

    Sah, D. N.; Viswanathan, U. K.; Ramadasan, E.; Unnikrishnan, K.; Anantharaman, S.

    2008-12-01

    The post irradiation examination (PIE) facility at the Bhabha Atomic Research Centre (BARC) has been in operation for more than three decades. Over these years this facility has been utilized for examination of experimental fuel pins and fuels from commercial power reactors operating in India. In a program to assess the performance of (U,Pu)O 2 MOX fuel prior to its introduction in commercial reactors, three experimental MOX fuel clusters irradiated in the pressurized water loop (PWL) of CIRUS up to burnup of 16 000 MWd/tU were examined. Fission gas release from these pins was measured by puncture test. Some of these fuel pins in the cluster contained controlled porosity pellets, low temperature sintered (LTS) pellets, large grain size pellets and annular pellets. PIE has also been carried out on natural UO 2 fuel bundles from Indian PHWRs, which included two high burnup (˜15 000 MWd/tU) bundles. Salient investigations carried out consisted of visual examination, leak testing, axial gamma scanning, fission gas analysis, microstructural examination of fuel and cladding, β, γ autoradiography of the fuel cross-section and fuel central temperature estimation from restructuring. A ThO 2 fuel bundle irradiated in Kakrapar Atomic Power Station (KAPS) up to a nominal fuel burnup of ˜11 000 MWd/tTh was also examined to evaluate its in-pile performance. The performance of the BWR fuel pins of Tarapur Atomic Power Stations (TAPS) was earlier assessed by carrying out PIE on 18 fuel elements selected from eight fuel assemblies irradiated in the two reactors. The burnup of these fuel elements varied from 5000 to 29 000 MWd/tU. This paper provides a brief review of some of the fuels examined and the results obtained on the performance of natural UO 2, enriched UO 2, MOX, and ThO 2 fuels.

  5. Emission factors from small scale appliances burning wood and pellets

    NASA Astrophysics Data System (ADS)

    Ozgen, Senem; Caserini, Stefano; Galante, Silvia; Giugliano, Michele; Angelino, Elisabetta; Marongiu, Alessandro; Hugony, Francesca; Migliavacca, Gabriele; Morreale, Carmen

    2014-09-01

    Four manually fed (6-11 kW) firewood burning and two automatic wood pellets (8.8-25 kW) residential heating appliances were tested under real-world operating conditions in order to determine emission factors (EFs) of macropollutants, i.e., carbon monoxide (CO), nitrogen oxides (NOx), non-methane hydrocarbons (NMHC), particulate matter (PM) and trace pollutants such as polycyclic aromatic hydrocarbons (PAH) and dioxins. The results were examined for the influence of different factors (i.e., type of wood, appliance and combustion cycle). The experimental EFs were also compared with the values proposed by the European emission inventory guidebook used in the local inventory in order to evaluate their representativeness of real world emissions. The composite macropollutant EFs for manually fed appliances were: for CO 5858 g GJ-1, for NOx 122 g GJ-1, NMHC 542 g GJ-1, PM 254 g GJ-1, whereas emissions were much lower for automatic pellets appliances: CO 219 g GJ-1, for NOx 66 g GJ-1, NMHC 5 g GJ-1, PM 85 g GJ-1. The highest emissions were generally observed for the open fireplace, however traditional and advanced stoves have the highest overall CO EFs. Especially for the advanced stove real-world emissions are far worse than those measured under cycles used for type testing of residential solid fuel appliances. No great difference is observed for different firewood types in batch working appliances, diversely the quality of the pellets is observed to influence directly the emission performance of the automatic appliances. Benzo(b)fluoranthene is the PAH with the highest contribution (110 mg GJ-1 for manual appliances and 2 mg GJ-1 for automatic devices) followed by benzo(a)pyrene (77 mg GJ-1 for manual appliances and 0.8 mg GJ-1 for automatic devices).

  6. Annual Post-Closure Inspection and Monitoring Report for Corrective Action Unit 329: Area 22 Desert Rock Airstrip Fuel Spill, Nevada Test Site, Nevada, Rev. No.: 0

    SciTech Connect

    Alfred Wickline

    2006-09-01

    This report presents the data collected during field activities and quarterly soil-gas sampling activities conducted from May 9, 2005, through May 20, 2006, at Corrective Action Unit (CAU) 329, Area 22 Desert Rock Airstrip (DRA) Fuel Spill; Corrective Action Site (CAS) 22-44-01, Fuel Spill. The CAU is located at the DRA, which is located approximately two miles southwest of Mercury, Nevada, as shown in Figure 1-1. Field activities were conducted in accordance with the revised sampling approach outlined in the Addendum to the Closure Report (CR) for CAU 329 (NNSA/NSO, 2005) to support data collection requirements. The previous annual monitoring program for CAU 329 was initiated in August 2000 using soil-gas samples collected from three specific intervals at the DRA-0 and DRA-3 monitoring wells. Results of four sampling events from 2000 through 2003 indicated there is uncertainty in the approach to establish a rate of natural attenuation as specified in ''Streamlined Approach for Environmental Restoration (SAFER) Work Plan for Corrective Action Unit 329: Area 22 Desert Rock Airstrip Fuel Spill, Nevada Test Site, Nevada'' (DOE/NV, 1999). As a result, the Addendum to the CR (NNSA/NSO, 2005) was completed to address this uncertainty by modifying the previous approach. A risk evaluation was added to the scope of the project to determine if the residual concentration of the hazardous constituents of JP4 pose an unacceptable risk to human health or the environment and if a corrective action was required at the site, because the current quarterly monitoring program is not expected to yield a rate constant that could be used effectively to determine a biodegradation rate for total petroleum hydrocarbons (TPH) in less than the initial five years outlined in the CR. Additionally, remediation to the Tier 1 action level for TPH is not practical or technically feasible due to the depth of contamination.

  7. Properties of melt extruded enteric matrix pellets.

    PubMed

    Schilling, Sandra U; Shah, Navnit H; Waseem Malick, A; McGinity, James W

    2010-02-01

    The objective of this study was to investigate the properties of enteric matrix pellets that were prepared by hot-melt extrusion in a one-step, continuous process. Five polymers (Eudragit) L100-55, L100 and S100, Aqoat grades LF and HF) were investigated as possible matrix formers, and pellets prepared with Eudragit S100 demonstrated superior gastric protection and acceptable processibility. Extruded pellets containing Eudragit S100 and up to 40% theophylline released less than 10% drug over 2h in acid, however, the processibility and yields were compromised by the high amounts of the non-melting drug material in the formulation. Efficient plasticization of Eudragit S100 was necessary to reduce the polymer's glass transition temperature and melt viscosity. Five compounds including triethyl citrate, methylparaben, polyethylene glycol 8000, citric acid monohydrate and acetyltributyl citrate were investigated in terms of plasticization efficiency and preservation of the delayed drug release properties. The aqueous solubility of the plasticizer and its plasticization efficiency impacted the drug release rate from the matrix pellets. The use of water-soluble plasticizers resulted in a loss of gastric protection, whereas low drug release rates in acid were found for pellets containing insoluble plasticizers or no plasticizer, independent of the extent of Eudragit S100 plasticization. The release rate of theophylline in buffer pH 7.4 was faster for pellets that were prepared with efficient plasticizers. The microstructure and solid-state properties of plasticized pellets were further investigated by scanning electron microscopy and powder X-ray diffraction. Pellets prepared with efficient plasticizers (TEC, methylparaben, PEG 8000) exhibited matrices of low porosity, and the drug was homogeneously dispersed in its original polymorphic form. Pellets containing ATBC or citric acid monohydrate had to be extruded at elevated temperature and showed physical instabilities in

  8. Thermophysical properties and modeling of a hydrogenic pellet production system

    NASA Astrophysics Data System (ADS)

    Leachman, Jacob William

    A fusion energy experiment that is under construction, the ITER machine, has the mission to be the first device to demonstrate the technological feasibility of fusion energy and serve as the primary step towards commercialization of fusion reactors. The ITER machine and future fusion energy machines will require a continuous supply of hydrogenic fuel pellets for sustained operation. The purpose of this research is to provide the fundamental visco-plastic flow measurements as well as the numerical models that are necessary to design a hydrogenic pellet production system (PPS) to meet the ITER fueling specifications. A numerical model of a PPS for the ITER machine is presented and used to design a system that precools, liquefies, and solidifies hydrogenic material that is ultimately extruded and cut into fuel pellets. The specific components modeled within the PPS include a precooling heat exchanger, a liquefier, and a twin-screw solidifying extruder. Numerical models of these components are developed and used as design tools. The modeling results suggest that the performance of the PPS will be dictated by the heat transfer and viscous dissipation associated with the solid and solidifying hydrogen in the twin-screw extruder. This observation motivates experimental efforts that are aimed at precise measurement of these quantities. Steady-state measurements are presented of the dynamic shear stress and heat transfer during flow of solid hydrogen, deuterium, and neon in a Couette type viscometer cell. Thermal conductivity measurements in the stationary condition are compared with those reported in the literature. The measurements span a range of shear rates and extend from temperatures associated with the onset of solidification to sub-cooled solid states. The viscous dissipation is found to vary directly with the applied heat load from the onset of solidification to the point at which the solid begins to sub-cool. Flow of the sub-cooled solid exhibits behavior that is

  9. Divertor load footprint of ELMs in pellet triggering and pacing experiments at JET

    NASA Astrophysics Data System (ADS)

    Frigione, D.; Garzotti, L.; Lennholm, M.; Alper, B.; Artaserse, G.; Bennett, P.; Giovannozzi, E.; Eich, T.; Kocsis, G.; Lang, P. T.; Maddaluno, G.; Mooney, R.; Rack, M.; Sips, G.; Tvalashvili, G.; Viola, B.; Wilkes, D.

    2015-08-01

    An investigation of pellet pacing and triggering of Edge Localized Modes (ELMs) was carried out in the frame of ELM mitigation studies aimed at reducing their damaging effects on the plasma-facing components (PFCs). The divertor power load footprint of triggered ELMs was compared with gas puffing controlled ELMs. Small pellets, corresponding to a few per cent of the target plasma particle inventory, were used to minimize the fueling effect and the total particle throughput. There is no evidence that pellets can reduce the divertor power load with respect to gas fueling when operating at the same ELM frequency. The line average density and the energy confinement time remained constant when the gas was progressively substituted by pellets. The launch from the Vertical High Field Side (VHFS) confirmed to be more efficient in ELM triggering than from the Low Field Side (LFS) while the power load footprint remained the same both in time evolution and in spatial distribution when changing the injection geometry.

  10. Cost of non-renewable energy in production of wood pellets in China

    NASA Astrophysics Data System (ADS)

    Wang, Changbo; Zhang, Lixiao; Liu, Jie

    2013-06-01

    Assessing the extent to which all bio-fuels that are claimed to be renewable are in fact renewable is essential because producing such renewable fuels itself requires some amount of non-renewable energy (NE) and materials. Using hybrid life cycle analysis (LCA)—from raw material collection to delivery of pellets to end users—the energy cost of wood pellet production in China was estimated at 1.35 J/J, of which only 0.09 J was derived from NE, indicating that only 0.09 J of NE is required to deliver 1 J of renewable energy into society and showing that the process is truly renewable. Most of the NE was consumed during the conversion process (46.21%) and delivery of pellets to end users (40.69%), during which electricity and diesel are the two major forms of NE used, respectively. Sensitivity analysis showed that the distance over which the pellets are transported affects the cost of NE significantly. Therefore the location of the terminal market and the site where wood resources are available are crucial to saving diesel.

  11. Ultrasonic vibration-assisted (UV-A) pelleting of wheat straw: a constitutive model for pellet density.

    PubMed

    Song, Xiaoxu; Zhang, Meng; Pei, Z J; Wang, Donghai

    2015-07-01

    Ultrasonic vibration-assisted (UV-A) pelleting can increase cellulosic biomass density and reduce biomass handling and transportation costs in cellulosic biofuel manufacturing. Effects of input variables on pellet density in UV-A pelleting have been studied experimentally. However, there are no reports on modeling of pellet density in UV-A pelleting. Furthermore, in the literature, most reported density models in other pelleting methods of biomass are empirical. This paper presents a constitutive model to predict pellet density in UV-A pelleting. With the predictive model, relations between input variables (ultrasonic power and pelleting pressure) and pellet density are predicted. The predicted relations are compared with those determined experimentally in the literature. Model predictions agree well with reported experimental results.

  12. Manufacture of bonded-particle nuclear fuel composites

    DOEpatents

    Stradley, J.G.; Sease, J.D.

    1973-10-01

    A preselected volume of nuclear fuel particles are placed in a cylindrical mold cavity followed by a solid pellet of resin--carbon matrix material of preselected volume. The mold is heated to liquefy the pellet and the liquefied matrix forced throughout the interstices of the fuel particles by advancing a piston into the mold cavity. Excess matrix is permitted to escape through a vent hole in the end of the mold opposite to that end where the pellet was originally disposed. After the matrix is resolidified by cooling, the resultant fuel composite is removed from the mold and the resin component of the matrix carbonized. (Official Gazette)

  13. Issues and Potential Program on Denatured Fuel Utilization.

    DTIC Science & Technology

    1978-12-01

    to current U02 fuel performance codes. The parameters of interest include the following: 0 fuel densification; * pellet- clad interaction (ratcheting...Mechanical sorting used. Tube rolling Expands tube and crushes fuel in tube. fuel chrushing Fuel cladding Mechanical screen device separates fuel...separator from cladding pieces. Assumes tube shear and whole bundle shear are comparable in cost. Special dissolvers Constructed of material to contain

  14. A 400-pellet feed system for the ORNL centrifuge pellet injector

    SciTech Connect

    Foster, C.A.; Qualls, A.L.; Baylor, L.R.; Schechter, D.E.; Dyer, G.R.; Milora, S.L.

    1993-11-01

    An improved and extended pellet fabrication and feed mechanism is being developed for the Oak Ridge National Laboratory (ORNL) centrifuge pellet injector that is presently installed on Tore Supra. This upgrade will extend the number of pellets available for a single-plasma discharge from 100 to 400. In addition, a new pusher and delivery system is expected to improve the performance of the device. As in the original system, deuterium ice is deposited from the gas phase on a liquid-helium-cooled rotating disk, forming a rim of solid deuterium. The rim of ice is machined to a parabolic profile from which pellets are pushed. In the new device, a stack of four ice rims are formed simultaneously, thereby increasing the capacity from 100 to 400 pellets. An improved method of ice formation has also been developed that produces clear ice. The pellet pusher and delivery system utilizes a four-axis, brushless dc servo system to precisely cut and deliver the pellets from the ice rim to the entrance of the centrifuge wheel. Pellets can be formed with sizes ranging from 2.5- to 4-mm diam at a rate of up to 8 per second. The operation of the injector is fully automated by a computer control system. The design and test results of the device are reported.

  15. HETEROGENEOUS NUCLEAR REACTOR EMPLOYING SMALL UNCLAD BODIES OF FISSIONABLE MATERIAL AS FUEL

    DOEpatents

    Hyman, H.H.; Katz, J.J.

    1961-05-01

    A nuclear reactor in which fuel pellets are continuously dissolved in a moderator liquid is described. The fuel pellets are fed into the top of elongated baskets which are submerged in moderator liquid, and a portion of the moderator liquid is continuously withdrawn and processed to recove r reaction products.

  16. The ORNL plasma fueling program

    SciTech Connect

    Gouge, M.J.; Milora, S.L.; Foster, C.A.; Combs, S.K.; Fisher, P.W.; Tsai, C.C.; Argo, B.E.; Barber, G.C.; Baylor, L.R.; Fehling, D.T.; Foust, C.R.; Jernigan, T.C.; Qualls, A.L.; Schechter, D.E.; Simmons, D.W.; Sohns, C.W.; Sparks, D.O.

    1989-01-01

    The Oak Ridge National Laboratory (ORNL) has been developing pellet injectors for over ten years. These devices produce frozen hydrogen isotope pellets and then accelerate the projectiles to speeds in the km/s range by either pneumatic or mechanical techniques. A variety of designs have been developed, including single-shot guns, multiple-shot guns, machine guns, and centrifugal accelerators. These injectors have been used to inject hydrogen and deuterium pellets into plasmas on numerous tokamak experiments resulting in improved plasma performance. ORNL has recently provided pellet fueling systems for the Tokamak Fusion Test Reactor (TFTR), the Joint European Torus (JET), and the Tore Supra tokamak. This paper discusses developments on these injector designs. 10 refs.

  17. Fabrication of fuel pin assemblies, phase 3

    NASA Technical Reports Server (NTRS)

    Keeton, A. R.; Stemann, L. G.

    1972-01-01

    Five full size and eight reduced length fuel pins were fabricated for irradiation testing to evaluate design concepts for a fast spectrum lithium cooled compact space power reactor. These assemblies consisted of uranium mononitride fuel pellets encased in a T-111 (Ta-8W-2Hf) clad with a tungsten barrier separating fuel and clad. Fabrication procedures were fully qualified by process development and assembly qualification tests. Detailed specifications and procedures were written for the fabrication and assembly of prototype fuel pins.

  18. FUEL PERFORMANCE IMPROVEMENT PROGRAM Thermal Conductivity of Sphere-Pac Fuel

    SciTech Connect

    Ades, M. J.

    1981-07-01

    Progress in understanding the thermal conductivity of sphere-pac fuel beds has been made both at Oregon State University and Exxon Nuclear Company supported by the Fuel Performance Improvement Program (FPIP). FPIP is sponsored by the U. S. Department of Energy and is being performed by Consumers Power Company, Exxon Nuclear Company, and Pacific Northwest Laboratory. The purpose of the program is to test and demonstrate improved li9ht water reactor fuel concepts that are more resistant to failure from pellet-cladding interaction during power increases than standard pellet fuel.

  19. Development of repetitive railgun pellet accelerator and steady-state pellet supply system

    SciTech Connect

    Oda, Y.; Onozuka, M.; Azuma, K.; Kasai, S.; Hasegawa, K.

    1995-12-31

    A railgun system for repetitive high-speed pellet acceleration and steady-state pellet supply system has been developed and investigated. Using a 2m-long railgun system, the hydrogen pellet was accelerated to 2.6km/sec by the supplied energy of 1.7kJ. It is expected that the hydrogen pellet can be accelerated to 3km/sec using the present pneumatic pellet accelerator and a 2m-long augment railgun. Screw-driven hydrogen-isotope filament extruding system has been fabricated and will be tested to examine its applicability to the steady-state extrusion of the solid hydrogen-isotope filament.

  20. The enhanced ASDEX Upgrade pellet centrifuge launcher

    NASA Astrophysics Data System (ADS)

    Plöckl, B.; Lang, P. T.

    2013-10-01

    Pellets played an important role in the program of ASDEX Upgrade serving both for investigations on efficient particle fuelling and high density scenarios but also for pioneering work on Edge Localised Mode (ELM) pacing and mitigation. Initially designed for launching fuelling pellets from the magnetic low field side, the system was converted already some time ago to inject pellets from the magnetic high field side as much higher fuelling efficiency was found using this configuration. In operation for more than 20 years, the pellet launching system had to undergo a major revision and upgrading, in particular of its control system. Furthermore, the control system installed adjacent to the launcher had to be transferred to a more distant location enforcing a complete galvanic separation from torus potential and a fully remote control solution. Changing from a hybrid system consisting of PLC S5/S7 and some hard wired relay control to a state of the art PLC system allowed the introduction of several new operational options enabling more flexibility in the pellet experiments. This article describes the new system architecture of control hardware and software, the operating procedure, and the extended operational window. First successful applications for ELM pacing and triggering studies are presented as well as utilization for the development of high density scenarios.

  1. Lithium Pellet Injector Development for NSTX

    SciTech Connect

    G. Gettelfinger; J. Dong; R. Gernhardt; H. Kugel; P. Sichta; J. Timberlake

    2003-12-04

    A pellet injector suitable for the injection of lithium and other low-Z pellets of varying mass into plasmas at precise velocities from 5 to 500 m/s is being developed for use on NSTX (National Spherical Torus Experiment). The ability to inject low-Z impurities will significantly expand NSTX experimental capability for a broad range of diagnostic and operational applications. The architecture employs a pellet-carrying cartridge propelled through a guide tube by deuterium gas. Abrupt deceleration of the cartridge at the end of the guide tube results in the pellet continuing along its intended path, thereby giving controlled reproducible velocities for a variety of pellets materials and a reduced gas load to the torus. The planned injector assembly has four hundred guide tubes contained in a rotating magazine with eight tubes provided for injection into plasmas. A PC-based control system is being developed as well and will be described elsewhere in these Proceedings. The development path and mechanical performance of the injector will be described.

  2. The enhanced ASDEX Upgrade pellet centrifuge launcher.

    PubMed

    Plöckl, B; Lang, P T

    2013-10-01

    Pellets played an important role in the program of ASDEX Upgrade serving both for investigations on efficient particle fuelling and high density scenarios but also for pioneering work on Edge Localised Mode (ELM) pacing and mitigation. Initially designed for launching fuelling pellets from the magnetic low field side, the system was converted already some time ago to inject pellets from the magnetic high field side as much higher fuelling efficiency was found using this configuration. In operation for more than 20 years, the pellet launching system had to undergo a major revision and upgrading, in particular of its control system. Furthermore, the control system installed adjacent to the launcher had to be transferred to a more distant location enforcing a complete galvanic separation from torus potential and a fully remote control solution. Changing from a hybrid system consisting of PLC S5/S7 and some hard wired relay control to a state of the art PLC system allowed the introduction of several new operational options enabling more flexibility in the pellet experiments. This article describes the new system architecture of control hardware and software, the operating procedure, and the extended operational window. First successful applications for ELM pacing and triggering studies are presented as well as utilization for the development of high density scenarios.

  3. The enhanced ASDEX Upgrade pellet centrifuge launcher

    SciTech Connect

    Plöckl, B.; Lang, P. T.

    2013-10-15

    Pellets played an important role in the program of ASDEX Upgrade serving both for investigations on efficient particle fuelling and high density scenarios but also for pioneering work on Edge Localised Mode (ELM) pacing and mitigation. Initially designed for launching fuelling pellets from the magnetic low field side, the system was converted already some time ago to inject pellets from the magnetic high field side as much higher fuelling efficiency was found using this configuration. In operation for more than 20 years, the pellet launching system had to undergo a major revision and upgrading, in particular of its control system. Furthermore, the control system installed adjacent to the launcher had to be transferred to a more distant location enforcing a complete galvanic separation from torus potential and a fully remote control solution. Changing from a hybrid system consisting of PLC S5/S7 and some hard wired relay control to a state of the art PLC system allowed the introduction of several new operational options enabling more flexibility in the pellet experiments. This article describes the new system architecture of control hardware and software, the operating procedure, and the extended operational window. First successful applications for ELM pacing and triggering studies are presented as well as utilization for the development of high density scenarios.

  4. Modeling the effects of pelleting on the logistics of distillers grains shipping.

    PubMed

    Rosentrater, Kurt A; Kongar, Elif

    2009-12-01

    The energy security needs of energy importing nations continue to escalate. It is clear that biofuels can help meet some of the increasing need for energy. Theoretically, these can be produced from a variety of biological materials, including agricultural residues (such as corn stover and wheat straw), perennial grasses, legumes, algae, and other biological materials. Currently, however, the most heavily utilized material is corn starch. Industrial fuel ethanol production in the US primarily uses corn, because it is readily converted into fuel at a relatively low cost compared to other biomass sources. The production of corn-based ethanol in the US is dramatically increasing. As the industry continues to grow, the amount of byproducts and coproducts also increases. At the moment, the nonfermentable residues (which are dried and sold as distillers dried grains with solubles--DDGS) are utilized only as livestock feed. The sale of coproducts provides ethanol processors with a substantial revenue source and significantly increases the profitability of the production process. Even though these materials are used to feed animals in local markets, as the size and scope of the industry continues to grow, the need to ship large quantities of coproducts grows as well. This includes both domestic as well as international transportation. Value-added processing options offer the potential to increase the sustainability of each ethanol plant, and thus the industry overall. However, implementation of new technologies will be dependent upon how their costs interact with current processing costs and the logistics of coproduct deliveries. The objective of this study was to examine some of these issues by developing a computer model to determine potential cost ramifications of using various alternative technologies during ethanol processing. This paper focuses specifically on adding a densification unit operation (i.e., pelleting) to produce value-added DDGS at a fuel ethanol

  5. Fuel characteristics required for LWR fuel rod calculations

    NASA Astrophysics Data System (ADS)

    De Meulemeester, E.

    1982-04-01

    BELGONUCLEAIRE gradually increasing in-reactor experience has enabled to assess the relative importance of attributes defined in specifications and drawings for both UO 2 and MO 2 fuels. On the basis of that experience, design codes have been benchmarked and were thereafter applied to cover the range of parameters and irradiation histories to be encountered or evaluated. To illustrate the effects of fuel characteristics on fuel behaviour, sensitivity calculations were performed on the basis of actual fuel irradiated in BWR's (DODEWAARD, GARIGLANO and OYSTER CREEK) and PWR's (BR3, DOEL, SENA, TIHANGE and MAINE YANKEE). The major characteristics are : fuel structure, UO 2 versus mixed oxide fuel; fuel accomodation (depending on the fuel microstructure and chemical composition); fuel density and densification stability; open porosity; pellet end geometry; pellet L/D ratio, gap size. Although the influence of the various parameters is not additive, these examples enable to determine the relative influence of each characteristic and to conclude to what accuracy it should be measured (in demo fuel) or controlled (in production fuel).

  6. Options for enhanced performance of pellet bed reactor bimodal systems

    NASA Astrophysics Data System (ADS)

    Liscum-Powell, Jennifer; El-Genk, Mohamed S.

    1995-01-01

    Recently reported Bimodal Pellet Bed Reactor (BM-PeBR) system concepts utilize efficient Closed Brayton Cycle (CBC) engines and maintain the maximum fuel temperature almost constant below 1600 K during power and propulsion modes. Because the reactor thermal power is quite low, ranging from 44 kW to 176 kW for the 10 kWe and 40 kWe BM-PeBR, respectively, the propulsion performance parameters are modest: 3.5 and 16 N of thrust for these systems, respectively, at a specific impulse (Isp) of 750 s. This paper investigates the effect of increasing the reactor thermal power and maximum fuel temperature during the propulsion mode to improve the propulsion performance of these systems. Options considered include: (a) using ex-core heating versus in-core heating of the hydrogen propellant, and (b) ramping reactor thermal power in the propulsion mode versus operating at a constant thermal power level during both power and propulsion modes and radiating excess heat during power mode using a high temperature radiator. Results showed that with these options the 40 kWe BM-PeBR system can deliver 40 N to 212 N of thrust and corresponding Isp of 885 s and 760 s, respectively, when operating at a maximum fuel temperature of 2000 K. Similarly, the 10 kWe system can deliver a thrust of 2 N to 40 N at corresponding Isp of 860 and 740 s, respectively.

  7. Compact Multifunction Inspection Head

    NASA Technical Reports Server (NTRS)

    Volpe, Richard A.; Ivlev, Robert; Ohm, Timothy

    1995-01-01

    Multiple-sensor inspection head designed to be mounted at tip of robot arm for performing multiple automated and/or remotely controlled inspection functions. Inspection head houses optoelectronic sensors, electrochemical sensor, sources of illumination, and parallel-jaw gripper.

  8. Surface Modification of Fuel Cladding Materials with Integral Fuel BUrnable Absorber Boron

    SciTech Connect

    Dr. Kumar Sridharan; Dr. Todd Allen; Jesse Gudmundson; Benjamin Maier

    2008-11-03

    Integral fuel burnable absorgers (IFBA) are added to some rods in the fuel assembly to counteract excessive reactivity. These IFBA elements (usually boron or gadolinium) are presently incorporated in the U)2 pellets either by mixing in the pellets or as coatings on the pellet surface. In either case, the incorporation of ifba into the fuel has to be performed in a nuclear-regulated facility that is physically separated from the main plant. These operations tend to be costly and can add from 20 to 30% to the manufacturing cost of the fuel. The goal of this NEER research project was to develop an alternative approach that involves incorporation of IFBA element boron at the surface of the fuel cladding material.

  9. An innovative fuel design concept for improved light water reactor performance and safety. Final technical report

    SciTech Connect

    Tulenko, J.S.; Connell, R.G.

    1995-07-01

    Light water reactor (LWR) fuel performance is limited by thermal and mechanical constraints associated with the design, fabrication, and operation of fuel in a nuclear reactor. The purpose of this research was to explore a technique for extending fuel performance by thermally bonding LWR fuel with a non-alkaline liquid metal alloy. Current LWR fuel rod designs consist of enriched uranium oxide (UO{sub 2}) fuel pellets enclosed in a zirconium alloy cylindrical clad. The space between the pellets and the clad is filled by an inert gas. Due to the thermal conductivity of the gas, the gas space thermally insulates the fuel pellets from the reactor coolant outside the fuel rod, elevating the fuel temperatures. Filling the gap between the fuel and clad with a high conductivity liquid metal thermally bonds the fuel to the cladding, and eliminates the large temperature change across the gap, while preserving the expansion and pellet loading capabilities. The resultant lower fuel temperature directly impacts fuel performance limit margins and also core transient performance. The application of liquid bonding techniques to LWR fuel was explored for the purposes of increasing LWR fuel performance and safety. A modified version of the ESCORE fuel performance code (ESBOND) has been developed under the program to analyze the in-reactor performance of the liquid metal bonded fuel. An assessment of the technical feasibility of this concept for LWR fuel is presented, including the results of research into materials compatibility testing and the predicted lifetime performance of Liquid Metal Bonded LWR fuel.

  10. A Gyrotron-Powered Pellet Accelerator

    NASA Astrophysics Data System (ADS)

    Perkins, F. W.; Parks, P. B.

    2005-10-01

    Plans for fuelling ITER call for accelerated pellets which propagate in guide-tubes. The tubes undergo 90 bends so that the pellets can enter the plasma along the high field-side of the separatrix. Both theory and experiment find that for V>= 500m/s, centrifugal force in the bends will fracture the pellets and elongate the cloud of debris. This contribution outlines the design of a plasma accelerator sufficiently flexible so that 90 bends can be avoided for the high-speed portions of the trajectory. The key element is to recognize that the guide tubes can also serve as a waveguide for millimeter waves. Operation proceeds as follows: A pellet is introduced into a guide tube of diameter 5mm at low velocity ˜10m/s and propagates until the remaining trajectory is straight and normal to separatrix. At this point, a 1 MW gyrotron is energized and power propagates until it encounters the pellet. The pellet has a 4-region structure and acts as a gun. The rear region (5mm) is diamond which passes the millimeter waves and provides inertia. Next is a 2mm region of frozen D doped with lithium which adsorbs the millimeter waves and vaporizes. The third region is a thin lithium layer which is several skin depths in extent and reflects millimeter waves. The 5 mm front region is a frozen DT bullet accelerated by the vaporized absorbing layer. The bullet now has a straight trajectory. 1D simulations of the gun will be presented.

  11. Red Light-enhanced Phytochrome Pelletability

    PubMed Central

    Pratt, Lee H.; Marmé, Dieter

    1976-01-01

    Red light-enhanced pelletability of phytochrome was observed in extracts of all 11 plants tested: Avena sativa L., Secale cereale L., Zea mays L., Cucurbita pepo L., Sinapis alba L., Pisum sativum L., Helianthus anuus L., Raphanus sativus L., Glycine max (L.) Merr., Phaseolus vulgaris L., and Lupinus albus L. This enhanced pelletability was observed in all 11 plants following in situ irradiation (in vivo binding) but only in Sinapis and Cucurbita after irradiation of crude extracts (in vitro binding). In vivo binding was not strongly dependent upon pH and, with few exceptions, was not markedly sensitive to high salt concentration, whereas in vitro binding was completely reversed by both high pH and high salt concentration. However, both binding phenomena were observed only with a divalent cation in the extract buffer. In vivo binding was further characterized using Avena which showed an increase in pelletability from less than 10% in dark control extracts to more than 60% in extracts of red light-irradiated shoots. The half-life for binding was 40 seconds at 0.5 C and was strongly temperature-dependent, binding being complete within 5 to 10 sec at 22 C. If pelletable phytochrome in the far red-absorbing form was photoconverted back to the red-absorbing form in situ, phytochrome was released from the pelletable condition with a half-life of 25 minutes at 25 C and 100 minutes at both 13 C and 3 C. No cooperativity in red light-enhanced pelletability with respect to phytochrome-far red-absorbing form was observed. PMID:16659745

  12. Pellet ablation and ablation model development

    SciTech Connect

    Houlberg, W.A.

    1989-01-01

    A broad survey of pellet ablation is given, based primarily on information presented at this meeting. The implications of various experimental observations for ablation theory are derived from qualitative arguments of the physics involved. The major elements of a more complete ablation theory are then outlined in terms of these observations. This is followed by a few suggestions on improving the connections between theory and experimental results through examination of ablation data. Although this is a rather aggressive undertaking for such a brief (and undoubtedly incomplete) assessment, some of the discussion may help us advance the understanding of pellet ablation. 17 refs.

  13. International Trade of Wood Pellets (Brochure)

    SciTech Connect

    Not Available

    2013-05-01

    The production of wood pellets has increased dramatically in recent years due in large part to aggressive emissions policy in the European Union; the main markets that currently supply the European market are North America and Russia. However, current market circumstances and trade dynamics could change depending on the development of emerging markets, foreign exchange rates, and the evolution of carbon policies. This fact sheet outlines the existing and potential participants in the wood pellets market, along with historical data on production, trade, and prices.

  14. CO{sub 2} pellet blasting studies

    SciTech Connect

    Archibald, K.E.

    1997-01-01

    Initial tests with CO{sub 2} pellet blasting as a decontamination technique were completed in 1993 at the Idaho Chemical Processing Plant (ICPP) at the Idaho National Engineering Laboratory (INEL). During 1996, a number of additional CO{sub 2} pellet blasting studies with Alpheus Cleaning Technologies, Oak Ridge National Laboratory, and Pennsylvania State University were conducted. After the testing with Alpheus was complete, an SDI-5 shaved CO{sub 2} blasting unit was purchased by the ICPP to test and determine its capabilities before using in ICPP decontamination efforts. Results of the 1996 testing will be presented in this report.

  15. Pellet impact drilling operational parameters: experimental research

    NASA Astrophysics Data System (ADS)

    Kovalyov, A. V.; Ryabchikov, S. Ya; Isaev, Ye D.; Aliev, F. R.; Gorbenko, M. V.; Baranova, A. V.

    2015-02-01

    The article deals with the study of particle-impact drilling that is designed to enhance the rate-of-penetration function in hard and tough drilling environments. It contains the experimental results on relation between drilling parameters and drilling efficiency, the experiments being conducted by means of a specially designed laboratory model. To interpret the results properly a high-speed camera was used to capture the pellet motion. These results can be used to choose optimal parameters, as well as to develop enhanced design of ejector pellet impact drill bits.

  16. Valve for fuel pin loading system

    DOEpatents

    Christiansen, David W.

    1985-01-01

    A cyclone valve surrounds a wall opening through which cladding is projected. An axial valve inlet surrounds the cladding. Air is drawn through the inlet by a cyclone stream within the valve. An inflatable seal is included to physically engage a fuel pin subassembly during loading of fuel pellets.

  17. Valve for fuel pin loading system

    DOEpatents

    Christiansen, D.W.

    1984-01-01

    A cyclone valve surrounds a wall opening through which cladding is projected. An axial valve inlet surrounds the cladding. Air is drawn through the inlet by a cyclone stream within the valve. An inflatable seal is included to physically engage a fuel pin subassembly during loading of fuel pellets.

  18. Valve for fuel pin loading system

    SciTech Connect

    Christiansen, D.W.

    1984-01-01

    A cyclone valve surrounds a wall opening through which cladding is projected. An axial valve inlet surrounds the cladding. Air is drawn through the inlet by a cyclone stream within the valve. An inflatable seal is included to physically engage a fuel pin subassembly during loading of fuel pellets.

  19. Settling behaviour of pellet flocs in pelleting flocculation process: analysis through operational conditions.

    PubMed

    Gang, Zhang; Ting-lin, Huang; Chi, Tan; Zhan-peng, Li; Wen-jie, He; Hong-da, Han; Chen, Li

    2010-01-01

    Pellet flocs' settling velocity is an important parameter in the pelleting flocculation blanket (PFB) process, hence, it is necessary to investigate flocs' settling behaviour to achieve the optimum operation parameters of the process. To investigate the settling behaviour of pellets under different operational conditions, a dynamic experiment was carried out to concentrate ferric flocs sludge by pelleting flocculation blanket (PFB) process with the scale of 0.5-1.2 m3/h. Under different operating conditions such as raw water concentration, polyacrylamide (PAM) dosage, up-flow rate, and agitation speed, pellet particles were sampled from different locations of the blanket in various operating stages to analyze pellet size, setting velocity, and porosity. Experimental results indicated that, when the PAM dosage increased from 0.59 mg/L to 1.18 mg/L, pellets size would flocculated from 2.25 mm to 3.52 mm with the settling velocity accelerated from 3.28 mm/s to 7.37 mm/s, while under the same up-flow rate, agitation intensity and PAM dosage, accompany with the raw water concentration increased from 216 mg/L to 840 mg/L, pellets settling velocity would improved from 6.03 mm/s to 13.6 mm/s. Under the experimental condition, along with the up-flow rate increased from 13.3 m/h to 40 m/h, pellets settling velocity would decreased from 4.39 mm/s to 3.42 mm/s due to its lower density.

  20. Quality assurance inspections for shipping and storage containers

    SciTech Connect

    Stromberg, H.M.; Roberts, G.D.; Bryce, J.H.

    1996-04-01

    This is a guide for conducting quality assurance inspections of transportation packaging and dry spent fuel storage system suppliers. (Suppliers are defined as designers, fabricators, distributors, users or owners of those packaging and storage systems.) This guide may be used during inspection to determine regulatory compliance with 10 CFR, Part 71, Subpart H; 10 CFR, Part 72, Subpart G; 10 CFR, Part 21; and supplier`s quality assurance program commitments. It was developed to provide a structured, consistent approach to inspections. The guidance therein provides a framework for evaluation of transportation packaging and dry spent fuel storage systems quality assurance programs. Inspectors are provided with the flexibility to adapt the methods and concepts to meet inspection requirements for the particular facility. The method used in the guide treats each activity at a facility as a separate performance element and combines the activities within the framework of an ``inspection tree.``The method separates each performance element into several areas for inspection and identifies guidelines, based on regulatory requirements, to qualitatively evaluate each area. This guide also serves as a field manual to facilitate quality assurance inspection activities. This guide replaces an earlier one, NUREG/CR-5717 (Packing Supplier Inspection Guide). This replacement guide enhances the inspection activities for transportation packagings and adds the dry spent fuel storage system quality assurance inspection activities.

  1. Nuclear fuel pin scanner

    DOEpatents

    Bramblett, Richard L.; Preskitt, Charles A.

    1987-03-03

    Systems and methods for inspection of nuclear fuel pins to determine fiss loading and uniformity. The system includes infeed mechanisms which stockpile, identify and install nuclear fuel pins into an irradiator. The irradiator provides extended activation times using an approximately cylindrical arrangement of numerous fuel pins. The fuel pins can be arranged in a magazine which is rotated about a longitudinal axis of rotation. A source of activating radiation is positioned equidistant from the fuel pins along the longitudinal axis of rotation. The source of activating radiation is preferably oscillated along the axis to uniformly activate the fuel pins. A detector is provided downstream of the irradiator. The detector uses a plurality of detector elements arranged in an axial array. Each detector element inspects a segment of the fuel pin. The activated fuel pin being inspected in the detector is oscillated repeatedly over a distance equal to the spacing between adjacent detector elements, thereby multiplying the effective time available for detecting radiation emissions from the activated fuel pin.

  2. Development of a fuseless small-bore railgun for injection of high-speed hydrogen pellets into magnetically confined plasmas

    SciTech Connect

    Kim, K.; Zhang, J.; King, T.L.; Manns, W.C.; Haywood, R.G. )

    1993-01-01

    The most effective known way of refueling a tokamak fusion reactor is to inject high-speed pellets composed of fusion fuel (i.e., isotopes of hydrogen) at a controlled rate and velocity. To effect such a fueling scheme, in particular for contemporary and future large tokamaks, pellet speeds as high as 10 km/s and injection rates as high a 10 Hz may very well be required. Also, to prevent the onset of plasma instabilities pellet sizes need to be maintained below 3 to 4 mm in diameter. These requirements, plus the fact that the yield strength of frozen hydrogen is extremely low ([approximately]2 atmospheres) make the task of developing in ideal pellet injection scheme a challenge. In an attempt to meet this challenge, a fuseless small-bore railgun has been under development at the University of Illinois during the past several years. Some of the unique features of this railgun system are: (1) it is a two-stage accelerator with the first stage consisting of a combination of a hydrogen pellet generator and a gas gun, and the second stage a railgun, (2) it is a fuseless railgun in that the plasma armature is formed by electrically breaking down the propellant gas immediately behind the pellet, (3) it is a smallbore railgun with the bore size in the range of a few millimeters in diameter. This report presents a brief review of some of the existing hydrogen pellet acceleration techniques, an overview of the University of Illinois railgun program, the results to date, and the future plan.

  3. Effect of ingredients and processing parameters on pellet quality.

    PubMed

    Briggs, J L; Maier, D E; Watkins, B A; Behnke, K C

    1999-10-01

    Rations containing varying ratios of corn, high-oil corn, soybean meal, and mechanically expelled soybean meal were pelleted. The effects of ingredients, conditioning steam pressure, and mixing paddle configuration inside the conditioner on pellet quality were investigated. Ration ingredients strongly affected pellet quality. Increasing the protein content increased the pellet durability, whereas increasing the oil content above 7.5% greatly decreased pellet durability. High-oil corn and mechanically expelled soybean meal produced acceptable pellets when combined with soybean meal and regular corn, respectively. However, poor pellet quality resulted when rations containing high-oil corn and mechanically expelled soybean meal were processed. Increasing the residence time in the conditioner by changing mixing paddle pitch resulted in an average 4.5-point increase in pellet durability indices among 65:35 (wt) corn:soybean meal and 65:35 high-oil corn:soybean meal rations.

  4. 3. INTERIOR VIEW OF PELLETIZER BUILDING, BALLING DRUM (UPPER RIGHT) ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. INTERIOR VIEW OF PELLETIZER BUILDING, BALLING DRUM (UPPER RIGHT) AND FURNACE (LOWER LEFT), LOOKING EAST - Mesabi Iron Company, Magnetic Concentration Plant, Pelletizer Building, Babbitt, St. Louis County, MN

  5. Pure crystalline estradiol pellet implantation for contraception.

    PubMed

    Asch, R H; Greenblatt, R B; Mahesh, V B

    1978-01-01

    The subcutaneous implantation of estradiol pellets was found to be a simple and effective contraceptive method with good patient acceptance and minimal untoward effects. The pellets (25 mg each) were implanted through a Kearn's trocar into the abdominal wall, 2.5 to 5 cm above and parallel to Poupart's ligament. The regimen began with four pellets, and the dose was maintained or decreased by one pellet every 6 months (four, three, two, one). A potent progestogen was utilized monthly for induction of withdrawal bleeding. Altogether, 236 patients were followed for a total of 1,060 courses in 6,360 cycles (489,02 woman-years). Two pregnancies occurred during therapy. Pearl's index was 0.37. No significant alterations occurred in body weight and blood pressure. Glucose tolerance test, standard blood profiles, and Papanicolaou smears were normal during therapy. No cases of thrombophlebitis, blurred vision, headaches, gastric symptoms, or amenorrhea-galactorrhea were observed. The suppression of ovulation was confirmed by endometrial biopsies, basal body temperature, and serum follicle-stimulating hormone, luteinizing hormone, estradiol, and progesterone in a selected group of patients.

  6. Hardwood control using pelleted herbicides and burning

    Treesearch

    James H. Miller

    1982-01-01

    Treatments using combinations of pelletized herbicides with prescribe burning were tested for planting site preparation on steep terrain (>35% slopes) in the Alabama Piedmont. Mixed forests of southern pines, oaks, and hickories occupied areas before logging. Three burning treatments (no-burn, pre- and post-harvest) were applied randomly among three 4-acre major...

  7. The Manufacturing Process of Bamboo Pellets

    Treesearch

    Zhijia Liu; Zehui Jiang; Zhiyong Cai; Benhua Fei; Xing' e Liu

    2012-01-01

    Bamboo was a kind of biomass materials and had great potential as a bio-energy resource of the future in China. The physical and combustion properties of bamboo pellets were determined and the effects of moisture content (MC) and sizes of particle on these properties were investigated in this research. The results showed that MC and sizes of particle affected these...

  8. 10 CFR Appendix O to Part 110 - Illustrative List of Fuel Element Fabrication Plant Equipment and Components Under NRC's Export...

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... the integrity of completed fuel pins (or rods). This item typically includes equipment for: (i) X-ray... (iii) Gamma-ray scanning of the pins (or rods) to check for correct loading of the fuel pellets inside....

  9. 10 CFR Appendix O to Part 110 - Illustrative List of Fuel Element Fabrication Plant Equipment and Components Under NRC's Export...

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... (iii) Gamma-ray scanning of the pins (or rods) to check for correct loading of the fuel pellets inside. ... the integrity of completed fuel pins (or rods). This item typically includes equipment for: (i)...

  10. Inspection and Emotion

    ERIC Educational Resources Information Center

    Perryman, Jane

    2007-01-01

    In this paper I explore the emotional impact of inspection on the staff of a school in the two years between Ofsted inspections. Using data from one school undergoing inspection, I argue that the negative emotional impact of inspection of teachers goes beyond the oft-reported issues of stress and overwork. Teachers experience a loss of power and…

  11. Improvement of Plasma Performance Using Carbon Pellet Injection in Large Helical Device

    NASA Astrophysics Data System (ADS)

    Shigeru, Morita; Motoshi, Goto; Kenichi, Nagaoka; Chunfeng, Dong; Hangyu, Zhou; Zhengying, Cui; Yunbo, Dong; Xiang, Gao; Katsumi, Ida; Katsunori, Ikeda; Osamu, Kaneko; Shiyao, Lin; Haruhisa, Nakano; Masaki, Osakabe; Ryuichi, Sakamoto; Yasuhiko, Takeiri; Ang, Ti; Katsuyoshi, Tsumori; Mikiro, Yoshinuma; LHD experiment Group

    2011-06-01

    A cylindrical carbon pellet with a size of 1.2L × 1.2varphi mm to 1.8L × 1.8varphi mm and a velocity of 100 m/s to 300 m/s was injected into large helical device (LHD) for an efficient fueling based on its deeper deposition instead of hydrogen gas puffing and ice pellet injection. Electron density increment of Δne = 1014 cm-3 is successfully obtained by single carbon pellet injection without plasma collapse. Typical density and temperature of the ablation plasma of the carbon pellet, e.g., 6.5 × 1016 cm-3 and 2.5 eV for CII, are examined respectively by spectroscopic method. A confinement improvement up to 50% compared to ISS-95 stellarator scaling is clearly observed in a relatively low-density regime of ne = 2×1013 cm-3 to 4×1013 cm-3, and high ion temperature Ti(0) of about 6 keV is also observed with an internal transport barrier at ne = 1.2×1013 cm-3. In particular, the improvement in the ion temperature largely exceeds that observed in hydrogen gas-puffed discharges, which typically ranges below 3 keV.

  12. Owl Pellet Analysis--A Useful Tool in Field Studies

    ERIC Educational Resources Information Center

    Medlin, G. C.

    1977-01-01

    Describes a technique by which the density and hunting habits of owls can be inferred from their pellets. Owl pellets--usually small, cylindrical packages of undigested bone, hair, etc.--are regurgitated by a roosting bird. A series of activities based on owl pellets are provided. (CP)

  13. Effects of carbonization conditions on properties of bamboo pellets

    Treesearch

    Zhijia Liu; Zehui Jiang; Zhiyong Cai; Benhua Fei; Yan Yu; Xing' e Liu

    2013-01-01

    Bamboo is a biomass material and has great potential as a bio-energy resource of the future in China. Bamboo pellets were successfully manufactured using a laboratory pellet mill in preliminary work. This study was therefore carried out to investigate the effect of carbonization conditions (temperature and time) on properties of bamboo pellets and to evaluate product...

  14. Owl Pellet Analysis--A Useful Tool in Field Studies

    ERIC Educational Resources Information Center

    Medlin, G. C.

    1977-01-01

    Describes a technique by which the density and hunting habits of owls can be inferred from their pellets. Owl pellets--usually small, cylindrical packages of undigested bone, hair, etc.--are regurgitated by a roosting bird. A series of activities based on owl pellets are provided. (CP)

  15. Hydride fuel behavior in LWRs

    NASA Astrophysics Data System (ADS)

    Olander, Donald R.; Ng, Marowen

    2005-11-01

    The U-Zr hydride U 0.31ZrH 1.6 offers a number of advantages over oxide fuel for light-water reactors. Fission-gas release appears to be very small (release fraction ˜10 -4) up to 600 °C, which is close to the maximum fuel temperature. Initial irradiation-induced swelling can be as large as 5% for temperatures exceeding 650 °C. Hydrogen redistributes due to the non-uniform temperature in the fuel from the as-fabricated H/Zr of 1.6 to one that is higher at the pellet periphery than at the centerline. Radial redistribution produces 'hydrogen' stresses in the pellet which add to the usual thermal stresses. In a helium-bonded fuel rod, the total stresses are less than the fracture stress; in a liquid-metal-bonded fuel rod, the fracture stress is exceeded in the central portion of the pellet, but the surface remains in compression. Axial redistribution moves substantial quantities of hydrogen from the middle portion of the fuel stack to the ends. The neutronic effect of this displacement of the moderator is unknown.

  16. 46 CFR 169.236 - Inspection and testing required.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... boundaries of fuel tanks; or (2) To pipelines, heating coils, pumps, fittings, or other appurtenances... particular vessel. If the inspection indicates that the operations can be undertaken with safety,...

  17. 46 CFR 169.236 - Inspection and testing required.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... boundaries of fuel tanks; or (2) To pipelines, heating coils, pumps, fittings, or other appurtenances... particular vessel. If the inspection indicates that the operations can be undertaken with safety,...

  18. 10 CFR 72.168 - Inspection, test, and operating status.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... inspections and tests performed upon individual items of the ISFSI, MRS, or spent fuel storage cask. These... of the ISFSI or MRS, such as tagging valves and switches, to prevent inadvertent operation....

  19. 10 CFR 72.168 - Inspection, test, and operating status.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... inspections and tests performed upon individual items of the ISFSI, MRS, or spent fuel storage cask. These... of the ISFSI or MRS, such as tagging valves and switches, to prevent inadvertent operation....

  20. 10 CFR 72.168 - Inspection, test, and operating status.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... inspections and tests performed upon individual items of the ISFSI, MRS, or spent fuel storage cask. These... of the ISFSI or MRS, such as tagging valves and switches, to prevent inadvertent operation....

  1. 10 CFR 72.168 - Inspection, test, and operating status.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... inspections and tests performed upon individual items of the ISFSI, MRS, or spent fuel storage cask. These... of the ISFSI or MRS, such as tagging valves and switches, to prevent inadvertent operation....

  2. 10 CFR 72.168 - Inspection, test, and operating status.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... inspections and tests performed upon individual items of the ISFSI, MRS, or spent fuel storage cask. These... of the ISFSI or MRS, such as tagging valves and switches, to prevent inadvertent operation....

  3. Technical specification: Mixed-oxide pellets for the light-water reactor irradiation demonstration test

    SciTech Connect

    Cowell, B.S.

    1997-06-01

    This technical specification is a Level 2 Document as defined in the Fissile Materials Disposition Program Light-Water Reactor Mixed-oxide Fuel Irradiation Test Project Plan. It is patterned after the pellet specification that was prepared by Atomic Energy of Canada, Limited, for use by Los Alamos National Laboratory in fabrication of the test fuel for the Parallex Project, adjusted as necessary to reflect the differences between the Canadian uranium-deuterium reactor and light-water reactor fuels. This specification and the associated engineering drawing are to be utilized only for preparation of test fuel as outlined in the accompanying Request for Quotation and for additional testing as directed by Oak Ridge National Laboratory or the Department of Energy.

  4. Additive Manufacturing Infrared Inspection

    NASA Technical Reports Server (NTRS)

    Gaddy, Darrell; Nettles, Mindy

    2015-01-01

    The Additive Manufacturing Infrared Inspection Task started the development of a real-time dimensional inspection technique and digital quality record for the additive manufacturing process using infrared camera imaging and processing techniques. This project will benefit additive manufacturing by providing real-time inspection of internal geometry that is not currently possible and reduce the time and cost of additive manufactured parts with automated real-time dimensional inspections which deletes post-production inspections.

  5. Combustion of char-coal waste pellets for high efficiency and low NO{sub x}. Quarterly report, 1 December 1994--28 February 28, 1995

    SciTech Connect

    Rajan, S.

    1995-12-31

    High efficiencies can be obtained from combined cycle power plants where fuel gas produced in a carbonizer is used to power the topping cycle turbines, while the residual char is burnt to raise steam for the bottoming Rankine cycle plant. Illinois coals are excellent fuels for these high efficiency power plants as the sulfur in the fuel gas is removed in the carbonization process by adding dolomite, thus producing a clean burning fuel gas. The residual char has essentially no volatiles, and is of low density. Because of these characteristics the char requires a longer residence time for efficient combustion. This research is directed towards improving the residence time of the char by pelletizing it with a waste coal, while at the same time reducing the sulfur dioxide emissions from the char combustion. During this quarter, extensive experimentation has been performed to determine the char-gob waste proportions necessary for forming pellets with desirable compression strength for feeding into the circulating fluidized bed combustor. Carbonizer char-gob coal pellets have been made with 5, 10 and 15 weight percent of cornstarch binder. Based on the test data presented, it is concluded that 10--15% weight percent of binder will be required when pelletizing char-gob coal waste mixtures containing 30-40 percent by weight of gob coal. During the next quarter, these pellets will be made in larger quantities and their combustion and emissions properties will be evaluated in a bench scale 4-inch diameter circulating fluidized bed combustor.

  6. POTENTIAL IMPACT OF INTERFACIAL BONDING EFFICIENCY ON USED NUCLEAR FUEL VIBRATION INTEGRITY DURING NORMAL TRANSPORTATION

    SciTech Connect

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

    2014-01-01

    Finite element analysis (FEA) was used to investigate the impacts of interfacial bonding efficiency at pellet pellet and pellet clad interfaces on surrogate of used nuclear fuel (UNF) vibration integrity. The FEA simulation results were also validated and benchmarked with reversible bending fatigue test results on surrogate rods consisting of stainless steel (SS) tubes with alumina-pellet inserts. Bending moments (M) are applied to the FEA models to evaluate the system responses of the surrogate rods. From the induced curvature, , the flexural rigidity EI can be estimated as EI=M/ . The impacts of interfacial bonding efficiency include the moment carrying capacity distribution between pellets and clad and cohesion influence on the flexural rigidity of the surrogate rod system. The result also indicates that the immediate consequences of interfacial de-bonding are a load carrying capacity shift from the fuel pellets to the clad and a reduction of the composite rod flexural rigidity. Therefore, the flexural rigidity of the surrogate rod and the bending moment bearing capacity between the clad and fuel pellets are strongly dependent on the efficiency of interfacial bonding at the pellet pellet and pellet clad interfaces. FEA models will be further used to study UNF vibration integrity.

  7. Fuel-performance-improvement program. Semiannual progress report, October 1980-March 1981. [Sphere-pac and annular-coated-pressurized

    SciTech Connect

    Crouthamel, C E; Freshley, M D

    1981-04-01

    Progress on the Fuel Performance Improvement Program's fuel test and demonstration irradiations is reported for the period of October 1980-March 1981. The purpose of the program is to test and demonstrate improved light water reactor fuel concepts that are more resistant to failure from pellet-cladding interaction during power increases than standard pellet fuel. This would also offer extended burnup potential and, hence, improved uranium utilization.

  8. Lighting Studies for Fuelling Machine Deployed Visual Inspection Tool

    SciTech Connect

    Stoots, Carl; Griffith, George

    2015-04-01

    Under subcontract to James Fisher Nuclear, Ltd., INL has been reviewing advanced vision systems for inspection of graphite in high radiation, high temperature, and high pressure environments. INL has performed calculations and proof-of-principle measurements of optics and lighting techniques to be considered for visual inspection of graphite fuel channels in AGR reactors in UK.

  9. 10 CFR 72.232 - Inspection and tests.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 2 2011-01-01 2011-01-01 false Inspection and tests. 72.232 Section 72.232 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSING REQUIREMENTS FOR THE INDEPENDENT STORAGE OF SPENT NUCLEAR FUEL... Storage Casks § 72.232 Inspection and tests. (a) The certificate holder and applicant for a CoC...

  10. 10 CFR 72.232 - Inspection and tests.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 2 2010-01-01 2010-01-01 false Inspection and tests. 72.232 Section 72.232 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSING REQUIREMENTS FOR THE INDEPENDENT STORAGE OF SPENT NUCLEAR FUEL... Storage Casks § 72.232 Inspection and tests. (a) The certificate holder and applicant for a CoC...

  11. 10 CFR 72.232 - Inspection and tests.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 2 2013-01-01 2013-01-01 false Inspection and tests. 72.232 Section 72.232 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSING REQUIREMENTS FOR THE INDEPENDENT STORAGE OF SPENT NUCLEAR FUEL... Storage Casks § 72.232 Inspection and tests. (a) The certificate holder and applicant for a CoC shall...

  12. 10 CFR 72.232 - Inspection and tests.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 2 2014-01-01 2014-01-01 false Inspection and tests. 72.232 Section 72.232 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSING REQUIREMENTS FOR THE INDEPENDENT STORAGE OF SPENT NUCLEAR FUEL... Storage Casks § 72.232 Inspection and tests. (a) The certificate holder and applicant for a CoC shall...

  13. Modeling Dynamic Fracture of Cryogenic Pellets

    SciTech Connect

    Parks, Paul

    2016-06-30

    This work is part of an investigation with the long-range objective of predicting the size distribution function and velocity dispersion of shattered pellet fragments after a large cryogenic pellet impacts a solid surface at high velocity. The study is vitally important for the shattered pellet injection (SPI) technique, one of the leading technologies being implemented at ORNL for the mitigation of disruption damage on current tokamaks and ITER. The report contains three parts that are somewhat interwoven. In Part I we formulated a self-similar model for the expansion dynamics and velocity dispersion of the debris cloud following pellet impact against a thick (rigid) target plate. Also presented in Part I is an analytical fracture model that predicts the nominal or mean size of the fragments in the debris cloud and agrees well with known SPI data. The aim of Part II is to gain an understanding of the pellet fracturing process when a pellet is shattered inside a miter tube with a sharp bend. Because miter tubes have a thin stainless steel (SS) wall a permanent deformation (dishing) of the wall is produced at the site of the impact. A review of the literature indicates that most projectile impact on thin plates are those for which the target is deformed and the projectile is perfectly rigid. Such impacts result in “projectile embedding” where the projectile speed is reduced to zero during the interaction so that all the kinetic energy (KE) of the projectile goes into the energy stored in plastic deformation. Much of the literature deals with perforation of the target. The problem here is quite different; the softer pellet easily undergoes complete material failure causing only a small transfer of KE to stored energy of wall deformation. For the real miter tube, we derived a strain energy function for the wall deflection using a non-linear (plastic) stress-strain relation for 304 SS. Using a dishing profile identical to the linear Kirchkoff-Love profile (for lack

  14. Simulation of peeling-ballooning modes with pellet injection

    SciTech Connect

    Chen, S. Y.; Huang, J.; Sun, T. T.; Tang, C. J.; Wang, Z. H.

    2014-11-15

    The influence of pellet ablation on the evolution of peeling-ballooning (P-B) modes is studied with BOUT++ code. The atoms coming from pellet ablation can significantly reshape the plasma pressure profile, so the behaviors of P-B modes and edge localized mode (ELM) are modified dramatically. This paper shows that the energy loss associated with an ELM increases substantially over that without the pellet, if the pellet is deposited at the top of the pedestal. On the contrary, for pellet deposition in the middle of the pedestal region the ELM energy loss can be less.

  15. Aircraft Fuel Systems Career Ladder.

    DTIC Science & Technology

    1985-09-01

    type fittings remove and install fuel cells clean work areas inspect aircraft for safety pin installation purge tanks or cells using blow purge method...INSPECT AIRCRAFT FOR SAFETY PIN INSTALLATION 84 H254 PURGE TANKS OR CELLS USING BLOW PURGE METHOD 83 H227 CHECK AIRCRAFT FOR LIQUID OXYGEN (LOX...H243 INSPECT AIRCRAFT FOR SAFETY PIN INSTALLATION 52 M483 MIX SEALANTS BY HAND 48 K372 CONNECT OR DISCONNECT WIGGINS TYPE FITTINGS 48 H236 DISCONNECT

  16. Electromagnetic railgun hydrogen pellet injector: Progress and prospect

    SciTech Connect

    Kim, Kyekyoon

    1988-12-01

    A two-stage, fuseless, plasma-arc-driven electromagnetic railgun system suitable for hydrogen pellet acceleration has been developed and successfully tested. The first stage is a combination of a hydrogen pellet generator and a gas gun, which is responsible for injecting a medium-velocity hydrogen pellet into the second-stage railgun through a coupling piece. As the pellet enters the railgun, a specially designed arc-initiation scheme electrically breaks down the propellant gas which has followed the pellet from the gas gun into the railgun, thus forming a conducting plasma-arc armature immediately behind the pellet. This arc formation event coincides with the triggering of the main railgun current and allows the plasma-arc armature to subsequently propel the hydrogen pellet to a high velocity. Using this two-stage acceleration scheme with a 1-m-long railgun barrel, solid hydrogen pellet velocities in excess of 2.2 km/s have been achieved for a pellet 3.2 mm in diameter and 4 mm in length. The objectives of this paper are two-fold: first, a critical review of the achievements thus far on the railgun hydrogen-pellet injector and second, a description of the most recent technological developments and their implications for future work, in particular, the prospect of employing a railgun pellet injector for future large devices. 6 refs., 2 figs., 1 tab.

  17. On the possibility of using uranium-beryllium oxide fuel in a VVER reactor

    SciTech Connect

    Kovalishin, A. A.; Prosyolkov, V. N.; Sidorenko, V. D.; Stogov, Yu. V.

    2014-12-15

    The possibility of using UO{sub 2}-BeO fuel in a VVER reactor is considered with allowance for the thermophysical properties of this fuel. Neutron characteristics of VVER fuel assemblies with UO{sub 2}-BeO fuel pellets are estimated.

  18. The results of postirradiation examinations of VVER-1000 and VVER-440 fuel rods

    NASA Astrophysics Data System (ADS)

    Dubrovin, K. P.; Ivanov, E. G.; Strijov, P. N.; Yakovlev, V. V.

    1991-02-01

    The paper presents the results of postirradiation examination of the fuel rods having different fuel-cladding gaps, pellet densities, pellet inner diameters and so on. The fuel rods were irradiated in the material science reactor (MR) of the Kurchatov Institute of Atomic Energy and at 4 unit of the Novo-Voronezh nuclear powerplant. Some data on fission gas release and rod geometry and compared with computer code predictions.

  19. Energy properties of solid fossil fuels and solid biofuels

    SciTech Connect

    Holubcik, Michal Jandacka, Jozef

    2016-06-30

    The paper deals about the problematic of energy properties of solid biofuels in comparison with solid fossil fuels. Biofuels are alternative to fossil fuels and their properties are very similar. During the experiments were done in detail experiments to obtain various properties of spruce wood pellets and wheat straw pellets like biofuels in comparison with brown coal and black coal like fossil fuels. There were tested moisture content, volatile content, fixed carbon content, ash content, elementary analysis (C, H, N, S content) and ash fusion temperatures. The results show that biofuels have some advantages and also disadvantages in comparison with solid fossil fuels.

  20. Energy properties of solid fossil fuels and solid biofuels

    NASA Astrophysics Data System (ADS)

    Holubcik, Michal; Kolkova, Zuzana; Jandacka, Jozef

    2016-06-01

    The paper deals about the problematic of energy properties of solid biofuels in comparison with solid fossil fuels. Biofuels are alternative to fossil fuels and their properties are very similar. During the experiments were done in detail experiments to obtain various properties of spruce wood pellets and wheat straw pellets like biofuels in comparison with brown coal and black coal like fossil fuels. There were tested moisture content, volatile content, fixed carbon content, ash content, elementary analysis (C, H, N, S content) and ash fusion temperatures. The results show that biofuels have some advantages and also disadvantages in comparison with solid fossil fuels.

  1. High-rate behaviour of iron ore pellet

    NASA Astrophysics Data System (ADS)

    Gustafsson, Gustaf; Häggblad, Hans-Åke; Jonsén, Pär; Nishida, Masahiro

    2015-09-01

    Iron ore pellets are sintered, centimetre-sized spheres of ore with high iron content. Together with carbonized coal, iron ore pellets are used in the production of steel. In the transportation from the pelletizing plants to the customers, the iron ore pellets are exposed to different loading situations, resulting in degradation of strength and in some cases fragmentation. For future reliable numerical simulations of the handling and transportation of iron ore pellets, knowledge about their mechanical properties is needed. This paper describes the experimental work to investigate the dynamic mechanical properties of blast furnace iron ore pellets. To study the dynamic fracture of iron ore pellets a number of split Hopkinson pressure bar tests are carried out and analysed.

  2. Optimal allocation of International Atomic Energy Agency inspection resources

    SciTech Connect

    Markin, J.T.

    1987-12-01

    The Safeguards Department of the International Atomic Energy Agency (IAEA) conducts inspections to assure the peaceful use of a state's nuclear materials and facilities. Because of limited resources for conducting inspections, the careful disposition of inspection effort among these facilities is essential if the IAEA is to attain its safeguards goals. This report describes an optimization procedure for assigning an inspection effort to maximize attainment of IAEA goals. The procedure does not require quantitative estimates of safeguards effectiveness, material value, or facility importance. Instead, the optimization is based on qualitative, relative prioritizations of inspection activities and materials to be safeguarded. This allocation framework is applicable to an arbitrary group of facilities such as a state's fuel cycle, the facilities inspected by an operations division, or all of the facilities inspected by the IAEA.

  3. Americium-based oxides: Dense pellet fabrication from co-converted oxalates

    NASA Astrophysics Data System (ADS)

    Horlait, Denis; Lebreton, Florent; Gauthé, Aurélie; Caisso, Marie; Arab-Chapelet, Bénédicte; Picart, Sébastien; Delahaye, Thibaud

    2014-01-01

    Mixed oxides are used as nuclear fuels and are notably envisaged for future fuel cycles including plutonium and minor actinide recycling. In this context, processes are being developed for the fabrication of uranium-americium mixed-oxide compounds for transmutation. The purpose of these processes is not only the compliance with fuel specifications in terms of density and homogeneity, but also the simplification of the process for its industrialization as well as lowering dust generation. In this paper, the use of a U0.85Am0.15O2±δ powder synthesized by oxalate co-conversion as a precursor for dense fuel fabrications is assessed. This study notably focuses on sintering, which yielded pellets up to 96% of the theoretical density, taking advantage of the high reactivity and homogeneity of the powder. As-obtained pellets were further characterized to be compared to those obtained via processes based on the UMACS (Uranium Minor Actinide Conventional Sintering) process. This comparison highlights several advantages of co-converted powder as a precursor for simplified processes that generate little dust.

  4. Tritium pellet injection sequences for TFTR

    SciTech Connect

    Houlberg, W.A.; Milora, S.L.; Attenberger, S.E.; Singer, C.E.; Schmidt, G.L.

    1983-01-01

    Tritium pellet injection into neutral deuterium, beam heated deuterium plasmas in the Tokamak Fusion Test Reactor (TFTR) is shown to be an attractive means of (1) minimizing tritium use per tritium discharge and over a sequence of tritium discharges; (2) greatly reducing the tritium load in the walls, limiters, getters, and cryopanels; (3) maintaining or improving instantaneous neutron production (Q); (4) reducing or eliminating deuterium-tritium (D-T) neutron production in non-optimized discharges; and (5) generally adding flexibility to the experimental sequences leading to optimal Q operation. Transport analyses of both compression and full-bore TFTR plasmas are used to support the above observations and to provide the basis for a proposed eight-pellet gas gun injector for the 1986 tritium experiments.

  5. Production of sintered porous metal fluoride pellets

    DOEpatents

    Anderson, L.W.; Stephenson, M.J.

    1973-12-25

    Porous pellets characterized by a moderately reactive crust and a softer core of higher reactivity are produced by forming agglomerates containing a metal fluoride powder and a selected amount ofwater. The metal fluoride is selected to be sinterable and essentially non-reactive with gaseous fluorinating agents. The agglomerates are contacted with a gaseous fluorinating agent under controlled conditions whereby the heat generated by localized reaction of the agent and water is limited to values effccting bonding by localized sintering. Porous pellets composed of cryolite (Na/sub 3/AlF/sub 6/) can be used to selectively remove trace quantities of niobium pentafluoride from a feed gas consisting predominantly of uranium hexafluoride. (Official Gazette)

  6. Optimization of Porous Pellets for Phosphate Recovery ...

    EPA Pesticide Factsheets

    The poster presents the preliminary adsorption experiment showing that phosphate concentration is decreasing over time as well as presenting the kinetics models that best fit the data collected over 25 days. The purpose of this project is to find a better material for adsorption of phosphate from water treatment facilities. The material is made into pellets which allow for adsorption and are easier to remove from the system when capacity is reached.

  7. Pellet fabrication development using thermally denitrated UO{sub 2} powder

    SciTech Connect

    Davis, N.C.; Griffin, C.W.

    1992-05-01

    Pacific Northwest Laboratory (PNL) has evaluted, on a laboratory scale, the characteristics and pellet fabrication properties of UO{sub 3} powder prepared by the thermal denitration process. Excellent quality, 96% TD (percent of theoretical density) pellets were produced from development lots of this powder. Apparently, the key to making this highly sinterable powder from uranyl nitrate is the addition of ammonium nitrate (NH{sub 4}NO{sub 3}) to the feed solution prior to thermal denitration. Powder lots were processed with and without the NH{sub 4}NO{sub 3} addition in the feed solution. The lots included samples from the ORNL laboratory rotary kiln and from a larger scale rotary kiln at National Lead of Ohio (NLO). In the PNL evaluation, samples of UO{sub 3} were calculated and reduced to UO{sub 2}, followed by conventional process procedures to compare the sinterability of the powder lots. The high density pellets made from the powder lots, which included the NH{sub 4}NO{sub 3} addition, were reduced to Fast Breeder Reactor (FBR) density range of 88 to 92% TD by the use of poreformers. The NH{sub 4}NO{sub 3} addition also improved the sinterability properties of uranium oxide powders that contain thorium and cerium. Thorium and cerium were used as ``stand-in`` for plutonium used in urania-plutonia FBR fuel pellets. A very preliminary examination of a single lot of thermally denitrated uranium-plutonium oxide powder was made. This powder lot was made with the NH{sub 3}NO{sub 3} addition and produced pellets just above the FBR density range.

  8. Effects of headspace and oxygen level on off-gas emissions from wood pellets in storage.

    PubMed

    Kuang, Xingya; Shankar, Tumuluru Jaya; Sokhansanj, Shahab; Lim, C Jim; Bi, Xiaotao T; Melin, Staffan

    2009-11-01

    Few papers have been published in the open literature on the emissions from biomass fuels, including wood pellets, during the storage and transportation and their potential health impacts. The purpose of this study is to provide data on the concentrations, emission factors, and emission rate factors of CO(2), CO, and CH(4) from wood pellets stored with different headspace to container volume ratios with different initial oxygen levels, in order to develop methods to reduce the toxic off-gas emissions and accumulation in storage spaces. Metal containers (45 l, 305 mm diameter by 610 mm long) were used to study the effect of headspace and oxygen levels on the off-gas emissions from wood pellets. Concentrations of CO(2), CO, and CH(4) in the headspace were measured using a gas chromatograph as a function of storage time. The results showed that the ratio of the headspace ratios and initial oxygen levels in the storage space significantly affected the off-gas emissions from wood pellets stored in a sealed container. Higher peak emission factors and higher emission rates are associated with higher headspace ratios. Lower emissions of CO(2) and CO were generated at room temperature under lower oxygen levels, whereas CH(4) emission is insensitive to the oxygen level. Replacing oxygen with inert gases in the storage space is thus a potentially effective method to reduce the biomass degradation and toxic off-gas emissions. The proper ventilation of the storage space can also be used to maintain a high oxygen level and low concentrations of toxic off-gassing compounds in the storage space, which is especially useful during the loading and unloading operations to control the hazards associated with the storage and transportation of wood pellets.

  9. Effects of Headspace and Oxygen Level on Off-gas Emissions from Wood Pellets in Storage

    SciTech Connect

    Sokhansanj, Shahabaddine; Kuang, Xingya; Shankar, T.S.; Lim, C. Jim; Bi, X.T.; Melin, Staffan

    2009-10-01

    Few papers have been published in the open literature on the emissions from biomass fuels, including wood pellets, during the storage and transportation and their potential health impacts. The purpose of this study is to provide data on the concentrations, emission factors, and emission rate factors of CO2, CO, and CH4 from wood pellets stored with different headspace to container volume ratios with different initial oxygen levels, in order to develop methods to reduce the toxic off-gas emissions and accumulation in storage spaces. Metal containers (45 l, 305 mm diameter by 610 mm long) were used to study the effect of headspace and oxygen levels on the off-gas emissions from wood pellets. Concentrations of CO2, CO, and CH4 in the headspace were measured using a gas chromatograph as a function of storage time. The results showed that the ratio of the headspace ratios and initial oxygen levels in the storage space significantly affected the off-gas emissions from wood pellets stored in a sealed container. Higher peak emission factors and higher emission rates are associated with higher headspace ratios. Lower emissions of CO2 and CO were generated at room temperature under lower oxygen levels, whereas CH4 emission is insensitive to the oxygen level. Replacing oxygen with inert gases in the storage space is thus a potentially effective method to reduce the biomass degradation and toxic off-gas emissions. The proper ventilation of the storage space can also be used to maintain a high oxygen level and low concentrations of toxic off-gassing compounds in the storage space, which is especially useful during the loading and unloading operations to control the hazards associated with the storage and transportation of wood pellets.

  10. Pellets valorization of waste biomass harvested by coagulation of freshwater algae.

    PubMed

    Cancela, Ángeles; Sánchez, Ángel; Álvarez, Xana; Jiménez, Alejandro; Ortiz, Luis; Valero, Enrique; Varela, Paloma

    2016-03-01

    There is a comparison of different coagulants: calcium chloride (20, 60, 120 and 180 mg/L); sodium alginate (10 and 20 mg/L) and tannins of Eucalyptus globulus bark (10 and 20 mg/L) in order to make the most of each method. The results show that 20 mg/L of tannin achieved a recovery efficiency of 95.35±1.16, sodium alginate 90.49±0.53 and 84.04±2.29 for calcium chloride. Taking into account the economic side of the coagulants, obtaining tannins is a profitable process. Bark is waste biomass obtained in the forestry process; therefore it does not involve extra costs. Finally, the feasibility of making pellets from harvested algae was studied, and the results suggest that waste biomass pellets may be used as fuel in boilers in a mixture <54% with other waste sources as Eucalyptus g. branches.

  11. Pelletizing/reslurrying as a means of distributing and firing clean coal

    SciTech Connect

    Conkle, H.N.; Raghavan, J.K.; Smit, F.J.; Jha, M.C.

    1991-11-21

    The objective of this study is to develop technology that permits the practical and economic preparation, storage, handling, and transportation of coal pellets, which can be reslurried into Coal water fuels (CWF) suitable for firing in small- and medium-size commercial and industrial boilers, furnaces, and engines. The project includes preparing coal pellets and capsules from wet filter cake that can be economically stored, handled, transported, and reslurried into a CWF that can be suitably atomized and fired at the user site. The wet cakes studied were prepared from ultra-fine (95% -325 mesh) coal beneficiated by advanced froth-flotation techniques. The coals studied included two eastern bituminous coals, one from Virginia (Elkhorn) and one from Illinois (Illinois No. 6) and one western bituminous coal from Utah (Sky Line coal).

  12. Pelletizing/reslurrying as a means of distributing and firing clean coal

    SciTech Connect

    Conkle, H.N.

    1992-03-17

    The objective of this study is to develop technology that permits the practical and economic preparation, storage, handling, and transportation of coal pellets, which can be reslurried into Coal water fuels (CWF) suitable for firing in small- and medium-size commercial and industrial boilers, furnaces, and engines. The project includes preparing coal pellets and capsules from wet filter cake that can be economically stored, handled, transported, and reslurried into a CWF that can be suitably atomized and fired at the user site. The wet cakes studied were prepared from ultra-fine (95% -325 mesh) coal beneficiated by advanced froth-flotation techniques. The coals studied included two eastern bituminous coals, one from Virginia (Elkhorn) and one from Illinois (Illinois No. 6) and one western bituminous coal from Utah (Sky Line coal).

  13. Surface properties of beached plastic pellets.

    PubMed

    Fotopoulou, Kalliopi N; Karapanagioti, Hrissi K

    2012-10-01

    The presence of pollutants on plastic debris is an emerging environmental hot topic. Understanding the surface alteration of plastics while in the marine environment increases our understanding of the pollutant-plastic debris interaction. Plastic pellets are widely distributed throughout the world oceans. Eroded and virgin polyethylene (PE) and polypropylene (PP) pellets were studied for their surface properties to better understand the interaction between plastic and compounds in marine environment. Surface properties such as point of zero charge, surface area and pore volume, surface topography, functional groups and acid-base behavior are important factors which affect sorption. Virgin plastic pellets had homogeneous smooth surfaces that do not have any acid-base behavior. Eroded PE demonstrates an altered surface that at seawater pH acquires a negative charge due to ketone groups. The uneven surface and possible functional groups could have been formed from the erosion processes while floating at the sea surface and might explain the interaction of eroded plastics with microbes and metals. Copyright © 2012 Elsevier Ltd. All rights reserved.

  14. Stochastic modelling of power reactor fuel behavior

    NASA Astrophysics Data System (ADS)

    Mirza, Shahid Nawaz

    An understanding of the in-reactor behavior of nuclear fuel is essential to the safe and economic operation of a nuclear power plant. It is no longer possible to achieve this without computer code calculations. A state of art computer code, FRODO, for Fuel ROD Operation, has been developed to model the steady state behavior of fuel pins in a light water reactor and to do sensitivity analysis. FRODO concentrates on the thermal performance, fission product release and pellet-clad interaction and can be used to predict the fuel failure under the prevailing conditions. FRODO incorporates the numerous uncertainties involved in fuel behavior modeling, using statistical methods, to ascertain fuel failures and their causes. Sensitivity of fuel failure to different fuel parameters and reactor conditions can be easily evaluated. FRODO has been used to analyze the sensitivities of fuel failures to coolant flow reductions. It is found that the uncertainties have pronounced effects on conclusions about fuel failures and their causes.

  15. The impact of interface bonding efficiency on high-burnup spent nuclear fuel dynamic performance

    DOE PAGES

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

    2016-09-26

    Finite element analysis (FEA) was used to investigate the impact of interfacial bonding efficiency at pellet-pellet and pellet-clad interfaces of high-burnup (HBU) spent nuclear fuel (SNF) on system dynamic performance. Bending moments M were applied to FEA model to evaluate the system responses. From bending curvature, κ, flexural rigidity EI can be estimated as EI = M/κ. The FEA simulation results were benchmarked with experimental results from cyclic integrated reversal bending fatigue test (CIRFT) of HBR fuel rods. The consequence of interface debonding between fuel pellets and cladding is a redistribution of the loads carried by the fuel pellets tomore » the clad, which results in a reduction in composite rod system flexural rigidity. Furthermore, the interface bonding efficiency at the pellet-pellet and pellet-clad interfaces can significantly dictate the SNF system dynamic performance. With the consideration of interface bonding efficiency, the HBU SNF fuel property was estimated with CIRFT test data.« less

  16. Fuel flexible fuel injector

    DOEpatents

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

    2015-02-03

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

  17. Effects of pellet characteristics on L-lactic acid fermentation by R. oryzae: pellet morphology, diameter, density, and interior structure.

    PubMed

    Fu, Yong-Qian; Yin, Long-Fei; Zhu, Hua-Yue; Jiang, Ru; Li, Shuang; Xu, Qing

    2014-11-01

    The effects of pellet morphology, diameter, density, and interior structure on L-lactic acid fermentation by Rhizopus oryzae were characterized for different inoculum sizes and concentrations of peptone and CaCO3. Inoculum size was the most important factor determining pellet formation and diameter. The diameter decreased with increasing inoculum size, and larger pellets were observed for lower inoculum sizes. Peptone concentration had the greatest effect on pellet density, which increased with increasing peptone concentration. L-lactic acid production depended heavily on pellet density but not on pellet diameter. Low-density pellets formed easily under conditions of low peptone concentration and often had a relatively hollow structure, with a thin condensed layer surrounding the pellet and an extraordinarily loose biomass or hollow center. As expected, this structure greatly decreased production. The production of L-lactic acid increased until the density reached a certain level (50-60 kg/m(3)), in which the compact part was distributed homogeneously in the thick outer layer of the pellet and loose in the central layer. Homogeneously structured, denser pellets had limited mass transfer, causing a lower overall turnover rate. However, the interior structure remained nearly constant throughout all fermentation phases for pellets with the same density. CaCO3 concentration only had a slight influence on pellet diameter and density, probably because it increases spore germination and filamentous hypha extension. This work also provides a new analysis method to quantify the interior structure of pellets, thus giving insight into pellet structure and its relationship with productivity.

  18. A MULTIDIMENSIONAL AND MULTIPHYSICS APPROACH TO NUCLEAR FUEL BEHAVIOR SIMULATION

    SciTech Connect

    R. L. Williamson; J. D. Hales; S. R. Novascone; M. R. Tonks; D. R. Gaston; C. J. Permann; D. Andrs; R. C. Martineau

    2012-04-01

    Important aspects of fuel rod behavior, for example pellet-clad mechanical interaction (PCMI), fuel fracture, oxide formation, non-axisymmetric cooling, and response to fuel manufacturing defects, are inherently multidimensional in addition to being complicated multiphysics problems. Many current modeling tools are strictly 2D axisymmetric or even 1.5D. This paper outlines the capabilities of a new fuel modeling tool able to analyze either 2D axisymmetric or fully 3D models. These capabilities include temperature-dependent thermal conductivity of fuel; swelling and densification; fuel creep; pellet fracture; fission gas release; cladding creep; irradiation growth; and gap mechanics (contact and gap heat transfer). The need for multiphysics, multidimensional modeling is then demonstrated through a discussion of results for a set of example problems. The first, a 10-pellet rodlet, demonstrates the viability of the solution method employed. This example highlights the effect of our smeared cracking model and also shows the multidimensional nature of discrete fuel pellet modeling. The second example relies on our the multidimensional, multiphysics approach to analyze a missing pellet surface problem. As a final example, we show a lower-length-scale simulation coupled to a continuum-scale simulation.

  19. 26 CFR 48.4083-1 - Taxable fuel; administrative authority.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 16 2011-04-01 2011-04-01 false Taxable fuel; administrative authority. 48.4083..., and Taxable Fuel Taxable Fuel § 48.4083-1 Taxable fuel; administrative authority. (a) In general—(1... entered. (b) Place of inspection—(1) In general. Inspections may be at any place at which taxable fuel...

  20. 26 CFR 48.4083-1 - Taxable fuel; administrative authority.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 26 Internal Revenue 16 2013-04-01 2013-04-01 false Taxable fuel; administrative authority. 48.4083..., and Taxable Fuel Taxable Fuel § 48.4083-1 Taxable fuel; administrative authority. (a) In general—(1... entered. (b) Place of inspection—(1) In general. Inspections may be at any place at which taxable fuel...

  1. 26 CFR 48.4083-1 - Taxable fuel; administrative authority.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 26 Internal Revenue 16 2012-04-01 2012-04-01 false Taxable fuel; administrative authority. 48.4083..., and Taxable Fuel Taxable Fuel § 48.4083-1 Taxable fuel; administrative authority. (a) In general—(1... entered. (b) Place of inspection—(1) In general. Inspections may be at any place at which taxable fuel...

  2. Piping inspection instrument carriage

    SciTech Connect

    Zollinger, W.T.; Treanor, R.C.

    1993-09-20

    This invention is comprised of a pipe inspection instrument carriage for use with a pipe crawler or other locomotion means for performing internal inspections of piping surfaces. The carriage has a front leg assembly, a rear leg assembly and a central support connecting the two assemblies and for mounting an instrument arm having inspection instruments. The instrument arm has means mounted distally thereon for axially aligning the inspection instrumentation and means for extending the inspection instruments radially outward to operably position the inspection instruments on the piping interior. Also, the carriage has means for rotating the central support and the front leg assembly with respect to the rear leg assembly so that the inspection instruments azimuthally scan the piping interior. The instrument carriage allows performance of all piping inspection operations with a minimum of moving parts, thus decreasing the likelihood of performance failure.

  3. Permeability of wood pellets in the presence of fines.

    PubMed

    Yazdanpanah, F; Sokhansanj, S; Lau, A K; Lim, C J; Bi, X; Melin, S; Afzal, M

    2010-07-01

    Broken pellets and fines are produced when pellets are handled. The resistance to air flow was measured for clean pellets and for pellets mixed with 1-20% broken pellets (fines). A pellet diameter was 6mm. The lengths ranged from 6 to 12 mm. Clean pellets were defined as particles that remained on a 4mm screen. A typical sieve analysis showed 30% of the mass of particles that passed through the 4mm screen was smaller than 1mm. The airflow rates used in the experiment ranged from 0.004 to 0.357 ms(-1). The corresponding pressure drop ranged from 1.9 to 271 Pam(-1) for clean pellets, from 4.8 to 1100 Pam(-1) for 10% fines content, and from 7.9 to 1800 Pam(-1) for 20% fines content. Coefficients of Hukill and Ives' equation were estimated for clean pellets and a multiplier was defined to calculate pressure drop for pellets mixed with fines.

  4. Influences on particle shape in underwater pelletizing processes

    SciTech Connect

    Kast, O. E-mail: matthias.musialek@ikt.uni-stuttgart.de E-mail: christian.bonten@ikt.uni-stuttgart.de; Musialek, M. E-mail: matthias.musialek@ikt.uni-stuttgart.de E-mail: christian.bonten@ikt.uni-stuttgart.de; Geiger, K. E-mail: matthias.musialek@ikt.uni-stuttgart.de E-mail: christian.bonten@ikt.uni-stuttgart.de; Bonten, C. E-mail: matthias.musialek@ikt.uni-stuttgart.de E-mail: christian.bonten@ikt.uni-stuttgart.de

    2014-05-15

    Underwater pelletizing has gained high importance within the last years among the different pelletizing technologies, due to its advantages in terms of throughput, automation, pellet quality and applicability to a large variety of thermoplastics. The resulting shape and quality of pellets, however, differ widely, depending on material characteristics and effects not fully understood yet. In an experimental set-up, pellets of different volumes and shapes were produced and the medium pellet mass, the pellet surface and the bulk density were analyzed in order to identify the influence of material properties and process parameters. Additionally, the shaping kinetics at the die opening were watched with a specially developed camera system. It was found that rheological material properties correlate with process parameters and resulting particle form in a complex way. Higher cutting speeds were shown to have a deforming influence on the pellets, leading to less spherical s and lower bulk densities. More viscous materials, however, showed a better resistance against this. Generally, the viscous properties of polypropylene proofed to be dominant over the elastic ones in regard to their influence on pellet shape. It was also shown that the shapes filmed at the die opening and the actual form of the pellets after a cooling track do not always correlate, indicating a significant influence of thermodynamic properties during the cooling.

  5. High Burn-Up Spent Nuclear Fuel Vibration Integrity Study

    SciTech Connect

    Wang, Jy-An John; Wang, Hong; Jiang, Hao; Bevard, Bruce Balkcom; Howard, Rob L; Scaglione, John M

    2015-01-01

    The Oak Ridge National Laboratory (ORNL) has developed the cyclic integrated reversible-bending fatigue tester (CIRFT) approach to successfully demonstrate the controllable fatigue fracture on high burnup (HBU) spent nuclear fuel (SNF) in a normal vibration mode. CIRFT enables examination of the underlying mechanisms of SNF system dynamic performance. Due to the inhomogeneous composite structure of the SNF system, the detailed mechanisms of the pellet-pellet and pellet-clad interactions and the stress concentration effects at the pellet-pellet interface cannot be readily obtained from a CIRFT system measurement. Therefore, finite element analyses (FEAs) are used to translate the global moment-curvature measurement into local stress-strain profiles for further investigation. The major findings of CIRFT on the HBU SNF are as follows: SNF system interface bonding plays an important role in SNF vibration performance. Fuel structure contributes to SNF system stiffness. There are significant variations in stress and curvature of SNF systems during vibration cycles resulting from segment pellets and clad interactions. SNF failure initiates at the pellet-pellet interface region and appears to be spontaneous.

  6. Novel-shaped catalyst pellets for packed-bed reactors

    SciTech Connect

    Punuru, A.R.

    1987-01-01

    The effect of the shape of a catalyst pellet, on the performance of a packed bed reactor, is determined by evaluating the effectiveness factor and dimensionless overall rates of the catalyst pellet. Depending upon the values of Thiele modulus and Prater number the use of Novel-shaped catalyst pellets, such as Lessing ring type pellets or partition ring type pellets or spoked wheel type pellets, which improve the overall rate of the pellet, were suggested. The novel-shaped pellets were sectioned into a hollow cylinder and slabs. The dimensionless rates and effectiveness factors were determined for hollow cylinders and slabs separately and the total dimensionless overall rate for the pellet is obtained by adding, the individual rates for slabs and hollow cylinder. The catalyst shape effects were studied on the steam-methane reformer. It was found that using traditional catalyst, a hollow cylindrical pellet with R/sub i//R/sub p/ ratio of 0.39, the dimensionless overall rate decreased from 0.75 at the top, to 0.27 at the bottom of the reformer. Upon using Lessing rings at the top, partition rings at the center, and spoked wheel pellets at the bottom of the reformer, the reaction rate can be improved to 0.9 at the top and to 0.73 at the bottom of the reformer. Though benzene-hydrogenation is exothermic reaction, use of solid cylindrical pellet was suggested, because of the low Thiele modulus. Two-dimensional pseudo homogeneous and heterogeneous reactor models were solved for a first order nonisothermal reaction, considering isothermal pellets. The inclusion of nonisothermal effectiveness factor that consider shape effects was left for future work.

  7. Advancements in Underwater Inspection

    DTIC Science & Technology

    1989-05-01

    Guard. For example, the Underwater Survey in Lieu of Dry Dock program, mobile offshore drilling unit (MODU) underwater hull inspection, tension leg...could be used to perform various types of underwater inspection on tension leg platform (TLP) tendons and templates. Understanding inspection...intervention (Ref. 6). This technique has application to the inspection of the mooring chains and terminations on floating facilities, and tension leg

  8. Model of U3Si2 Fuel System using BISON Fuel Code

    SciTech Connect

    K. E. Metzger; T. W. Knight; R. L. Williamson

    2014-04-01

    This research considers the proposed advanced fuel system: U3Si2 combined with an advanced cladding. U3Si2 has a number of advantageous thermophysical properties, which motivate its use as an accident tolerant fuel. This preliminary model evaluates the behavior of U3Si2 using available thermophysical data to predict the cladding-fuel pellet temperature and stress using the fuel performance code: BISON. The preliminary results obtained from the U3Si2 fuel model describe the mechanism of Pellet-Clad Mechanical Interaction for this system while more extensive testing including creep testing of U3Si2 is planned for improved understanding of thermophysical properties for predicting fuel performance.

  9. Detection probabilities for random inspection in variable flow situations

    SciTech Connect

    Lu, Ming-Shih

    1994-03-01

    Improvements in the efficiency and effectiveness of inventory-change verification are necessary at certain nuclear facilities, of which one example is low-enriched uranium fuel fabrication facilities. The Safeguards Criteria suggested carrying out interim inventory-change verifications with randomized inspections. This paper describes randomized inspection schemes for inventory change verifications and evaluates the achievable detection probabilities for realistic plant receipt and shipment schedules and stratum residence times as a. function of the inspection frequency and effort and compares these with the existing inspection strategies.

  10. An Innovative High Thermal Conductivity Fuel Design

    SciTech Connect

    PI: James S. Tulenko; Co-PI: Ronald H. Baney,

    2007-10-14

    Uranium dioxide (UO2) is the most common fuel material in commercial nuclear power reactors. UO2 has the advantages of a high melting point, good high-temperature stability, good chemical compatibility with cladding and coolant, and resistance to radiation. The main disadvantage of UO2 is its low thermal conductivity. During a reactor’s operation, because the thermal conductivity of UO2 is very low, for example, about 2.8 W/m-K at 1000 oC [1], there is a large temperature gradient in the UO2 fuel pellet, causing a very high centerline temperature, and introducing thermal stresses, which lead to extensive fuel pellet cracking. These cracks will add to the release of fission product gases after high burnup. The high fuel operating temperature also increases the rate of fission gas release and the fuel pellet swelling caused by fission gases bubbles. The amount of fission gas release and fuel swelling limits the life time of UO2 fuel in reactor. In addition, the high centerline temperature and large temperature gradient in the fuel pellet, leading to a large amount of stored heat, increase the Zircaloy cladding temperature in a lost of coolant accident (LOCA). The rate of Zircaloy-water reaction becomes significant at the temperature above 1200 oC [2]. The ZrO2 layer generated on the surface of the Zircaloy cladding will affect the heat conduction, and will cause a Zircaloy cladding rupture. The objective of this research is to increase the thermal conductivity of UO2, while not affecting the neutronic property of UO2 significantly. The concept to accomplish this goal is to incorporate another material with high thermal conductivity into the UO2 pellet. Silicon carbide (SiC) is a good candidate, because the thermal conductivity of single crystal SiC is 60 times higher than that of UO2 at room temperature and 30 times higher at 800 oC [3]. Silicon carbide also has the properties of low thermal neutron absorption cross section, high melting point, good chemical

  11. Electronic Inspection of Beef

    NASA Technical Reports Server (NTRS)

    Anselmo, Victor J.; Gammell, Paul M.; Clark, Jerry

    1987-01-01

    Two proposed methods for grading beef quality based on inspection by electronic equipment: one method uses television camera to generate image of a cut of beef as customer sees it; other uses ultrasonics to inspect live animal or unsliced carcasses. Both methods show promise for automated meat inspection.

  12. Software Formal Inspections Guidebook

    NASA Technical Reports Server (NTRS)

    1993-01-01

    The Software Formal Inspections Guidebook is designed to support the inspection process of software developed by and for NASA. This document provides information on how to implement a recommended and proven method for conducting formal inspections of NASA software. This Guidebook is a companion document to NASA Standard 2202-93, Software Formal Inspections Standard, approved April 1993, which provides the rules, procedures, and specific requirements for conducting software formal inspections. Application of the Formal Inspections Standard is optional to NASA program or project management. In cases where program or project management decide to use the formal inspections method, this Guidebook provides additional information on how to establish and implement the process. The goal of the formal inspections process as documented in the above-mentioned Standard and this Guidebook is to provide a framework and model for an inspection process that will enable the detection and elimination of defects as early as possible in the software life cycle. An ancillary aspect of the formal inspection process incorporates the collection and analysis of inspection data to effect continual improvement in the inspection process and the quality of the software subjected to the process.

  13. Electronic Inspection of Beef

    NASA Technical Reports Server (NTRS)

    Anselmo, Victor J.; Gammell, Paul M.; Clark, Jerry

    1987-01-01

    Two proposed methods for grading beef quality based on inspection by electronic equipment: one method uses television camera to generate image of a cut of beef as customer sees it; other uses ultrasonics to inspect live animal or unsliced carcasses. Both methods show promise for automated meat inspection.

  14. Mixed oxide fuel development

    SciTech Connect

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

    1987-05-08

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

  15. FUEL ELEMENT FOR NUCLEAR REACTORS

    DOEpatents

    Dickson, J.J.

    1963-09-24

    A method is described whereby fuel tubes or pins are cut, loaded with fuel pellets and a heat transfer medium, sealed at each end with slotted fittings, and assembled into a rectangular tube bundle to form a fuel element. The tubes comprising the fuel element are laterally connected between their ends by clips and tabs to form a linear group of spaced parallel tubes, which receive their vertical support by resting on a grid. The advantages of this method are that it permits elimination of structural material (e.g., fuel-element cans) within the reactor core, and removal of at least one fuel pin from an element and replacement thereof so that a burnable poison may be utilized during the core lifetime. (AEC)

  16. Multidimensional multiphysics simulation of nuclear fuel behavior

    NASA Astrophysics Data System (ADS)

    Williamson, R. L.; Hales, J. D.; Novascone, S. R.; Tonks, M. R.; Gaston, D. R.; Permann, C. J.; Andrs, D.; Martineau, R. C.

    2012-04-01

    Nuclear fuel operates in an environment that induces complex multiphysics phenomena, occurring over distances ranging from inter-atomic spacing to meters, and times scales ranging from microseconds to years. This multiphysics behavior is often tightly coupled and many important aspects are inherently multidimensional. Most current fuel modeling codes employ loose multiphysics coupling and are restricted to 2D axisymmetric or 1.5D approximations. This paper describes a new modeling tool able to simulate coupled multiphysics and multiscale fuel behavior, for either 2D axisymmetric or 3D geometries. Specific fuel analysis capabilities currently implemented in this tool are described, followed by a set of demonstration problems which include a 10-pellet light water reactor fuel rodlet, three-dimensional analysis of pellet clad mechanical interaction in the vicinity of a defective fuel pellet, coupled heat transfer and fission product diffusion in a TRISO-coated fuel particle, a demonstration of the ability to couple to lower-length scale models to account for material property variation with microstructural evolution, and a demonstration of the tool's ability to efficiently solve very large and complex problems using massively-parallel computing. A final section describes an early validation exercise, comparing simulation results to a light water reactor fuel rod experiment.

  17. Biomass gasification for liquid fuel production

    NASA Astrophysics Data System (ADS)

    Najser, Jan; Peer, Václav; Vantuch, Martin

    2014-08-01

    In our old fix-bed autothermal gasifier we tested wood chips and wood pellets. We make experiments for Czech company producing agro pellets - pellets made from agricultural waste and fastrenewable natural resources. We tested pellets from wheat and rice straw and hay. These materials can be very perspective, because they dońt compete with food production, they were formed in sufficient quantity and in the place of their treatment. New installation is composed of allothermal biomass fixed bed gasifier with conditioning and using produced syngas for Fischer - Tropsch synthesis. As a gasifying agent will be used steam. Gas purification will have two parts - separation of dust particles using a hot filter and dolomite reactor for decomposition of tars. In next steps, gas will be cooled, compressed and removed of sulphur and chlorine compounds and carbon dioxide. This syngas will be used for liquid fuel synthesis.

  18. Biomass gasification for liquid fuel production

    SciTech Connect

    Najser, Jan E-mail: vaclav.peer@vsb.cz; Peer, Václav E-mail: vaclav.peer@vsb.cz

    2014-08-06

    In our old fix-bed autothermal gasifier we tested wood chips and wood pellets. We make experiments for Czech company producing agro pellets - pellets made from agricultural waste and fastrenewable natural resources. We tested pellets from wheat and rice straw and hay. These materials can be very perspective, because they dońt compete with food production, they were formed in sufficient quantity and in the place of their treatment. New installation is composed of allothermal biomass fixed bed gasifier with conditioning and using produced syngas for Fischer - Tropsch synthesis. As a gasifying agent will be used steam. Gas purification will have two parts - separation of dust particles using a hot filter and dolomite reactor for decomposition of tars. In next steps, gas will be cooled, compressed and removed of sulphur and chlorine compounds and carbon dioxide. This syngas will be used for liquid fuel synthesis.

  19. An Implicit Solution Framework for Reactor Fuel Performance Simulation

    SciTech Connect

    Glen Hansen; Chris Newman; Derek Gaston; Cody Permann

    2009-08-01

    The simulation of nuclear reactor fuel performance involves complex thermomechanical processes between fuel pellets, made of fissile material, and the protective cladding that surrounds the pellets. An important design goal for a fuel is to maximize the life of the cladding thereby allowing the fuel to remain in the reactor for a longer period of time to achieve higher degrees of burnup. This presentation presents an initial approach for modeling the thermomechanical response of reactor fuel, and details of the solution method employed within INL's fuel performance code, BISON. The code employs advanced methods for solving coupled partial differential equation systems that describe multidimensional fuel thermomechanics, heat generation, and oxygen transport within the fuel. This discussion explores the effectiveness of a JFNK-based solution of a problem involving three dimensional fully coupled, nonlinear transient heat conduction and that includes pellet displacement and oxygen diffusion effects. These equations are closed using empirical data that is a function of temperature, density, and oxygen hyperstoichiometry. The method appears quite effective for the fuel pellet / cladding configurations examined, with excellent nonlinear convergence properties exhibited on the combined system. In closing, fully coupled solutions of three dimensional thermomechanics coupled with oxygen diffusion appear quite attractive using the JFNK approach described here, at least for configurations similar to those examined in this report.

  20. A curious pellet from a great horned owl (Bubo virginianus)

    USGS Publications Warehouse

    Woodman, N.; Dove, C.J.; Peurach, S.C.

    2005-01-01

    One of the traditional methods of determining the dietary preferences of owls relies upon the identification of bony remains of prey contained in regurgitated pellets. Discovery of a pellet containing a large, complete primary feather from an adult, male Ring-necked Pheasant (Phasianus colchicus) prompted us to examine in detail a small sample of pellets from a Great Horned Owl (Bubo virginianus). Our analyses of feather and hair remains in these pellets documented the presence of three species of birds and two species of mammals, whereas bones in the pellets represented only mammals. This finding indicates an important bias that challenges the reliability of owl pellet studies making use of only osteological remains.