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  1. José Manuel Esteve : sus contribuciones al estudio de la profesión docente

    Directory of Open Access Journals (Sweden)

    Julio Vera

    2013-07-01

    Full Text Available Este artículo es un análisis de las contribuciones del profesor Esteve al estudio de la profesión docente. Para ello se hace un repaso a sus rasgos de personalidad, a los hitos más relevantes de su vida profesional y a algunas de sus publicaciones desde sus comienzos como profesor universitario en 1973 hasta su fallecimiento en el año 2010.This article analyzes the contributions of Professor Esteve around the teaching profession. His personality traits, the highlights of his career and some of his publications from his beginnings as a university professor in 1973 until his death in 2010 are the core of this study.

  2. Contribuciones al preprocesado, procesado y análisis en termografía infrarroja aplicados a ensayos no destructivos

    OpenAIRE

    Hidalgo-Gato García, Rafael

    2015-01-01

    RESUMEN: El empleo de las técnicas de medida mediante ensayos no destructivos por Termografía Infrarroja (TI) permite la evaluación y control de todo tipo de materiales y procesos de forma rápida, sencilla y sin contacto. Por ello, se estableció como objetivo general de este trabajo de tesis el desarrollo de contribuciones al conocimiento de las diferentes etapas del tratamiento digital de los termogramas, así como su aplicación a problemáticas reales y solución a las carencias detectadas. Es...

  3. A contribution to the analysis of the thermal behaviour of Fast Breeder fuel rods with UO{sub 2}-PuO{sub 2} fuel; Contribucion al analisis del comportamiento termico de las barras combustibles de UO{sub 2}-PuO{sub 2} de los reactores rapidos

    Energy Technology Data Exchange (ETDEWEB)

    Lopez Jimenez, J; Elbel, H

    1977-07-01

    The fuel of Fast Breeder Reactors which consists of Uranium and Plutonium dioxide is mainly characterized by the amount and distribution of void volume and Plutonium and the amount of oxygen. Irradiation experiments carried out with this fuel have shown that initial structure of the fuel pellet is subjected to large changes during operation. These are consequences of the radial and axial temperature gradients within the fuel rods. (Author) 54 refs.

  4. Algunas contribuciones al debate sobre la clínica de las psicosis

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    Juan Manuel Rodríguez

    Full Text Available La clínica de las psicosis plantea la necesidad de establecer una modalidad de tratamiento diferente al tratamiento de las neurosis. Esta practica implica un trabajo multidisciplinario cercano y frecuente en donde se establecen algunas coordenadas fundamentales en el devenir del tratamiento. Asimismo, en el interior del grupo de trabajo se presentan algunos fenómenos similares a la dinámica propia del paciente psicotico, por ello se hace necesario considerar la locura del grupo como un factor dinámico del tratamiento. En este sentido es fundamental partir de la singularidad del paciente para desarrollar el modelo único en cada caso, en el cual la intervención es un elemento que pretende sostener aquello que falla en la dimensión delirante del paciente.

  5. Contribuciones al conocimiento de las Magnoliácea de Colombia, V

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    Lozano Contreras Gustavo

    1978-12-01

    Full Text Available La consecución de material adicional de Magnoliaceae del sur de Colombia permite establecer dos nuevos taxa, ubicados en los géneros Dugandiodendron y Talauma, respectivamente.Al igual que Talauma dixonii Little y Dugandiodendron striatifolium (Little G. Lozano-c., conocidas de Esmeraldas, Ecuador, las nuevas especies reciben el nombre vernáculo de "Cucharillo". Como ocurre con otras magnoliáceas, la madera de estas especies es muy apreciada, por lo cual se les explota a pesar de la prohibición vigente en cuanto a tala; más aún, las especies que se describen están en peligro de extincion yes difícil obtener material completo de las mismas.  Los "cucharillos" han sido elementos importantes en la composición de la selva pluvial macrotérmica de la región tropical occidental ubicada en el Departamento de Nariño.

  6. Contribuciones de la modelización al desarrollo de las competencias básicas

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    Manel Sol

    2013-06-01

    Full Text Available For many years modelling activities have not been a common practice in the classroom despite having a wide recognition of their educational interest. Burkhardt i Pollack (2006 justify it by a lack of supporting materials and Antonius et al. (2007 indicate an insufficient guidance on teaching strategies. From this starting point some ideas are proposed to overcome these difficulties. The article is organized in three sections. In the first section shown relationship between modelling and curriculum. Moreover, the catalan curriculum is highlighted as it promotes mathematical projects, in the secondary education. In fact, project research (Projecte de recerca and Research work (Treball de recerca are two compulsory subjects in Catalonia which fit in with modelling activities. The second section, some activities are shown that can serve as an example to teachers. And also the teaching of skills in modelling activities. The last section shows the contributions of modelling activities to the development of basic competencies of current curriculum thus increasing their interest.

  7. Contribuciones al estudiode los anfibios y reptiles de Méxicodurante el siglo XVIII y la Ilustración

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    Gustavo Casas Andreu

    2008-01-01

    Full Text Available Las bases de la herpetología moderna en general se establecieron en el siglo XVIII,particularmente durante la Ilustración y quienes hicieron la mayor contribución fueronfundamentalmente los naturalistas franceses. No obstante, en México se hicieron varias publicacionesde cierto relieve, en especial por los misioneros jesuitas y otros estudiosos de la Nueva España. Esinteresante mencionar que aun con la trascendencia de Linneo para la biología moderna, algunoshistoriadores de los anfibios y los reptiles señalan que por lo menos para la herpetofauna de Méxicoexistió una importante regresión, ya que era mucho mayor el conocimiento que había dejadoFrancisco Hernández en el siglo XVI. Las contribuciones de los autores de la escuela francesa comoBuffon y quienes lo sucedieron como Lacepéde y Daudin, fueron los grandes pilares de laherpetología o estudios de los anfibios y los reptiles de la manera en que la conocemos en laactualidad. Las bases establecidas en el siglo XVIII sirvieron para que con la apertura de México almundo a partir de su independencia, se entrara en una de las etapas de mayor relevancia para laherpetología del país.

  8. Contribuciones al desarrollo de la investigación en enfermería: retos y perspectivas

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    Myriam Durán Parra

    2012-12-01

    Full Text Available Desde la etimología del término “investigación” la palabra proviene del latín in (en y vestigare (hallar, inquirir, indagar, seguir vestigios. De ahí el uso más elemental del término en el sentido de “averiguar o describir alguna cosa”. Desde el momento en que el hombre se enfrentó a problemas y frente a ellos empezó a interrogarse sobre el porqué, como y para que, con esta indagación sobre las cosas, de una manera embrionaria, comenzó lo que hoy llamamos investigación. Con el transcurso del tiempo el ser humano ha hecho un esfuerzo importante por sobrevivir y la mejor forma de lograrlo ha sido experimentando aportando al desarrollo del conocimiento científico.Donaldson y Bottorff (1978 expresan frente a la investigación en enfermería que “es la fuente de desarrollo de conocimiento que le da la característica de disciplina, que ha de estar presente tanto en la práctica clínica como en el desarrollo de la administración y la educación, que ha de dar respuesta a las necesidades sociales que están relacionadas con procesos de salud-enfermedad, condiciones y calidad de vida de las personas, familias y comunidades, en todos los grupos etarios” (1. Por su parte Borrero-Cabal (1994, afirma que “la disciplina conlleva al sentido de rigor, de dedicación, de entrenamiento y ejercicio de los hábitos científicos de la persona para elaborar, transmitir y aprender una ciencia” (2. En enfermería esto se traduce que para poder llevar el cuidado a los pacientes de una manera técnica, científica , analítica, debe tener unas bases como la dedicación, el amor por la profesión y el gusto por la investigación reconociendo que la enfermería avanza y se fortalece a medida que crece científicamente, mientras conoce la cultura, la riqueza de la naturaleza, forma parte del país y sobre todo del mundo como una profesión que demuestra su interés en la búsqueda de su propia identidad. 

  9. Contribution to swelling analysis in ceramic nuclear fuels; Contribucion al analisis del hinchamiento de combustibles nucleares ceramicos

    Energy Technology Data Exchange (ETDEWEB)

    Moreno Gonzalez, A

    1976-07-01

    In this work a swelling phenomenological model containing several experimental observation is presented. Observations such as dissolution and redi solution of gas atoms, bubble nucleations in defects, dislocations and grain boundary, bubbles migration and coalescence are included. The model gives a bubbles distribution according to their size and position the swelling rate is calculated through the bubble distribution changes. (Author) 17 refs.

  10. Contribuciones del Censo de Población y Viviendas 2012 al desarrollo socioeconómico del municipio Mayarí, Holguín, Cuba

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    Rafael Ángel Salazar Martínez

    2014-06-01

    Full Text Available El presente trabajo establece las coordenadas para la utilización eficiente de los resultados que arroje el Censo del Población y Viviendas del 2012, en función del desarrollo socioeconómico del municipio Mayarí, territorio que implementa desde ese mismo año un Programa Integral de Desarrollo Municipal (PIDM, cuya significación estratégica radica en el hecho de constituir la experiencia piloto a nivel nacional, para su generalización hacia otros municipios del país, respondiendo a los Lineamientos de la Política Económica y Social del Partido y la Revolución, en lo referente al desarrollo de proyectos locales. En este contexto, resulta de vital importancia el manejo y acceso a fuentes de información confiables y pertinentes, como las que ofrece el Censo de Población y Viviendas, que se traduzca luego en una mayor consistencia a la hora de tomar decisiones y gestionar todos los procesos que intervienen en la ejecución de este Programa.

  11. Contribuciones al conocimiento sobre la Ecología y distribución geográfica de Phrynops (Batrachemys Dahli; (Testudinata, Pleurodira, Chelidae Contribuciones al conocimiento sobre la Ecología y distribución geográfica de Phrynops (Batrachemys Dahli; (Testudinata, Pleurodira, Chelidae

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    Medem Federico

    1966-12-01

    Full Text Available 1. Data on Ecology, Behavior and Geographical Distribution of the chelid turtle, Phrynops (Batrachemys dahli, are reported. 2. The original habitat of the "carranchina" or "cabeza al lado" consisted in ponds and small brooks within the forests, a situation which has gradually changed; actually the entire area around the type locality is transformed into pastures. 3. It is principally carnivorous and feeds on snails, aquatic insects, tadpoles, frogs, small fishes, carrion, but also sometimes on vegetable matter. No endoparasites had been found. 4. A marked dimorphism exists between the two sexes (figs. 2, 4, 5. 5. The mating season takes place in June-July approximately. 6. From one to six white, hard-shelled, slightly ellipsoid eggs are laid mainly in September-October; they measure between 35.5 : 29.0 mm. and. 28.0 : 23.5 mm. (fig. 7. 7. In several females, captured in May 22, 1958, which died in June 1959, hard-shelled eggs and numerous ovules had been found. 8. A female, captured in September 24, 1963, laid October 22, 1963, four eggs in a shallow groove without covering them, possibly due to lack of time or the hard soil full of pebbles. Three of those eggs were apparently not fertilized and became dry within two months; the last one was finally opened in August 14, 1964; it measured 34.5 : 26.5 mm. and contained a Fetus almost ready to hatch (fig. 6; its Carapax measured 28.0 mm, (length and 22.5 mm. (width; the very protruding vitelline sack (12.0 : 11.0 mm. still covered the Plastron; an easy discernible Oviruptor was present. This does not necessarily mean that the incubation period normally lasts over ten months, but rather seems to indicate that the eggs are resistant enough to develop in spite of a prolonged dry season - common in the given area - without suffering lethal effects. 9. Taken from the great number of ovules in different state of development, together with hard-shelled eggs, it seems to indicate the possibility that the

  12. Mixing of Al into uranium silicides reactor fuels

    International Nuclear Information System (INIS)

    Ding, F.R.; Birtcher, R.C.; Kestel, B.J.; Baldo, P.M.

    1996-11-01

    SEM observations have shown that irradiation induced interaction of the aluminum cladding with uranium silicide reactor fuels strongly affects both fission gas and fuel swelling behaviors during fuel burn-up. The authors have used ion beam mixing, by 1.5 MeV Kr, to study this phenomena. RBS and the 27 Al(p, γ) 28 Si resonance nuclear reaction were used to measure radiation induced mixing of Al into U 3 Si and U 3 Si 2 after irradiation at 300 C. Initially U mixes into the Al layer and Al mixes into the U 3 Si. At a low dose, the Al layer is converted into UAl 4 type compound while near the interface the phase U(Al .93 Si .07 ) 3 grows. Under irradiation, Al diffuses out of the UAl 4 surface layer, and the lower density ternary, which is stable under irradiation, is the final product. Al mixing into U 3 Si 2 is slower than in U 3 Si, but after high dose irradiation the Al concentration extends much farther into the bulk. In both systems Al mixing and diffusion is controlled by phase formation and growth. The Al mixing rates into the two alloys are similar to that of Al into pure uranium where similar aluminide phases are formed

  13. Thermal behavior analysis of U-Mo/Al dispersion fuel

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, Ho Jin; Park, Jong Mang; Lee, Yoon Sang; Kim, Chang Kyu [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    2004-07-01

    According to the non-proliferation policy under the reduced enrichment for research and test reactors (RERTR) program, low enriched uranium(LEU) fuel such as uranium silicide dispersion fuels are being used in research reactors. Because of a lower enrichment higher uranium density fuels are required for some high performance research reactors. Some uranium alloys with a high uranium density such as U-Mo alloys have been considered as one of the most promising candidates for a dispersion fuel due to the good irradiation performance. An international qualification program to replace the uranium silicide dispersion fuel with U-Mo dispersion fuel is being carried out under the RERTR program. Although U-Mo powders are conventionally supplied by the mechanical comminuting of as-cast U-Mo alloys, KAERI developed a centrifugal atomization method in order to simplify the preparation process and improve the properties. The centrifugally atomized powders have a rapidly solidified gamma uranium structure and a spherical shape. During the in-reactor operation of a dispersion fuel, interdiffusion or chemical reactions between the fuel particles and the matrix occurr. Intermetallic compounds in the form of UAlx are formed as a result of the diffusional reaction. Because the intermetallic compounds are less dense than the combined reactants, the volume of the fuel element increases after the reaction. In addition to the effect on the swelling performance, the reaction layers between the U-Mo and the Al matrix induces a degradation of the thermal properties of the U-Mo/Al dispersion fuels. It is important to investigate the thermal behavior of U-Mo/Al dispersion fuel according to reaction between the fuel particles and the matrix with the burnup and linear power. In this study, a finite element analysis was used for the calculation of the temperature distribution of the U-Mo/Al dispersion fuel with a burnup and linear power. Kinetics data of the reaction layers such as the growth

  14. Thermal behavior analysis of U-Mo/Al dispersion fuel

    International Nuclear Information System (INIS)

    Ryu, Ho Jin; Park, Jong Mang; Lee, Yoon Sang; Kim, Chang Kyu

    2004-01-01

    According to the non-proliferation policy under the reduced enrichment for research and test reactors (RERTR) program, low enriched uranium(LEU) fuel such as uranium silicide dispersion fuels are being used in research reactors. Because of a lower enrichment higher uranium density fuels are required for some high performance research reactors. Some uranium alloys with a high uranium density such as U-Mo alloys have been considered as one of the most promising candidates for a dispersion fuel due to the good irradiation performance. An international qualification program to replace the uranium silicide dispersion fuel with U-Mo dispersion fuel is being carried out under the RERTR program. Although U-Mo powders are conventionally supplied by the mechanical comminuting of as-cast U-Mo alloys, KAERI developed a centrifugal atomization method in order to simplify the preparation process and improve the properties. The centrifugally atomized powders have a rapidly solidified gamma uranium structure and a spherical shape. During the in-reactor operation of a dispersion fuel, interdiffusion or chemical reactions between the fuel particles and the matrix occurr. Intermetallic compounds in the form of UAlx are formed as a result of the diffusional reaction. Because the intermetallic compounds are less dense than the combined reactants, the volume of the fuel element increases after the reaction. In addition to the effect on the swelling performance, the reaction layers between the U-Mo and the Al matrix induces a degradation of the thermal properties of the U-Mo/Al dispersion fuels. It is important to investigate the thermal behavior of U-Mo/Al dispersion fuel according to reaction between the fuel particles and the matrix with the burnup and linear power. In this study, a finite element analysis was used for the calculation of the temperature distribution of the U-Mo/Al dispersion fuel with a burnup and linear power. Kinetics data of the reaction layers such as the growth

  15. Rupture of Al matrix in U-Mo/Al dispersion fuel by fission induced creep

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Gwan Yoon; Sohn, Dong Seong [UNIST, Daejeon (Korea, Republic of); Kim, Yeon Soo [Argonne National Laboratory, Argonnge (United States); Lee, Kyu Hong [KAERI, Daejeon (Korea, Republic of)

    2016-05-15

    This phenomenon was found specifically in the dispersion fuel plate with Si addition in the Al matrix to suppress interaction layer (IL) formation between UMo and Al. It is known that the stresses induced by fission induced swelling in U-Mo fuel particles are relieved by creep deformation of the IL, surrounding the fuel particles, that has a much higher creep rate than the Al matrix. Thus, when IL growth is suppressed, the stress is instead exerted on the Al matrix. The observed rupture in the Al matrix is believed to be caused when the stress exceeded the rupture strength of the Al matrix. In this study, the possibility of creep rupture of the Al matrix between the neighboring U-Mo fuel particles was examined using the ABAQUS finite element analysis (FEA) tool. The predicted rupture time for a plate was much shorter than its irradiation life indicating a rupture during the irradiation. The higher stress leads Al matrix to early creep rupture in this plate for which the Al matrix with lower creep strain rate does not effectively relieve the stress caused by the swelling of the U-Mo fuel particles. For the other plate, no rupture was predicted for the given irradiation condition. The effect of creeping of the continuous phase on the state of stress is significant.

  16. Fission induced swelling of U–Mo/Al dispersion fuel

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yeon Soo, E-mail: yskim@anl.gov [Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 (United States); Jeong, G.Y. [Ulsan National Institute of Science and Technology, 50 UNIST-gil, Eonyang-eup, Uljoo-gun, Ulsan 689-798 (Korea, Republic of); Park, J.M. [Korea Atomic Energy Research Institute, 989-111 Daedeok-daero, Yuseong-gu, Daejeon 305-353 (Korea, Republic of); Robinson, A.B. [Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415-6188 (United States)

    2015-10-15

    Fission-induced swelling of U–Mo/Al dispersion fuel meat was measured using microscopy images obtained from post-irradiation examination. The data of reduced-size plate-type test samples and rod-type test samples were employed for this work. A model to predict the meat swelling of U–Mo/Al dispersion fuel was developed. This model is composed of several submodels including a model for interaction layer (IL) growth between U–Mo and Al matrix, a model for IL thickness to IL volume conversion, a correlation for the fission-induced swelling of U–Mo alloy particles, a correlation for the fission-induced swelling of IL, and models of U–Mo and Al consumption by IL growth. The model was validated using full-size plate data that were not included in the model development.

  17. Pore growth in U-Mo/Al dispersion fuel

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yeon Soo, E-mail: yskim@anl.gov [Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 (United States); Jeong, G.Y.; Sohn, D.-S. [Ulsan National Institute of Science and Technology, 50 UNIST-gil, Eonyang-eup, Ulju-gun, Ulsan, 689-798 (Korea, Republic of); Jamison, L.M. [Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 (United States)

    2016-09-15

    U-Mo/Al dispersion fuel is currently under development in the DOE’s Material Management and Minimization program to convert HEU-fueled research reactors to LEU-fueled reactors. In some demanding conditions in high-power and high-performance reactors, large pores form in the interaction layers between the U-Mo fuel particles and the Al matrix, which pose a potential to cause fuel failure. In this study, comprehension of the formation and growth of these pores was explored. As a product, a model to predict pore growth and porosity increase was developed. The model includes three major topics: fission gas release from the U-Mo and the IL to the pores, stress evolution in the fuel meat, and the effect of amorphous IL growth. Well-characterized in-pile data from reduced-size plates were used to fit the model parameters. A data set from full-sized plates, independent and distinctively different from those used to fit the model parameters, was used to examine the accuracy of the model. The model showed fair agreement with the measured data. The model suggested that the growth of the IL has a critical effect on pore growth, as both its material properties and energetics are favorable to pore formation. Therefore, one area of the current effort, focused on suppressing IL growth, appears to be on the right track to improve the performance of this fuel.

  18. INFLUENCE OF FUEL-MATRIX INTERACTION ON THE BREAKAWAY SWELLING OF U-MO DISPERSION FUEL IN AL

    OpenAIRE

    HO JIN RYU; YEON SOO KIM

    2014-01-01

    In order to advance understanding of the breakaway swelling behavior of U-Mo/Al dispersion fuel under a high-power irradiation condition, the effects of fuel-matrix interaction on the fuel performance of U-Mo/Al dispersion fuel were investigated. Fission gas release into large interfacial pores between interaction layers and the Al matrix was analyzed using both mechanistic models and observations of the post-irradiation examination results of U-Mo dispersion fuels. Using the model prediction...

  19. Mechanical analysis of UMo/Al dispersion fuel

    International Nuclear Information System (INIS)

    Jeong, Gwan Yoon; Kim, Yeon Soo; Sohn, Dong-Seong

    2015-01-01

    Deformation of fuel particles and mass transfer from the transverse end of fuel meat toward the meat center was observed. This caused plate thickness peaking at a location between the meat edge and the meat center. The underlying mechanism for this fuel volume transport is believed to be fission induced creep of the U–Mo/Al meat. Fuel meat swelling was measured using optical microscopy images of the cross sections of the irradiated test plates. The time-dependent meat swelling was modeled for use in numerical simulation. A distinctive discrepancy between the predicted and measured meat thickness was found at the meat ends, which was assumed to be due to creep-induced mass relocation from the meat end to the meat center region that was not considered in the meat swelling model. ABAQUS FEA simulation was performed to reproduce the observed phenomenon at the meat ends. Through the simulation, we obtained the effective creep rate constants for the interaction layers (IL) and aluminum matrix. In addition, we obtained the corresponding stress and strain analysis results that can be used to understand mechanical behavior of U–Mo/Al dispersion fuel.

  20. Mechanical analysis of UMo/Al dispersion fuel

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Gwan Yoon [Ulsan National Institute of Science and Technology, Department of Nuclear Engineering, 50 UNIST-gil, Eonyang-eup, Ulju-gun, Ulsan, 689-798 (Korea, Republic of); Kim, Yeon Soo [Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 (United States); Sohn, Dong-Seong, E-mail: dssohn@unist.ac.kr [Ulsan National Institute of Science and Technology, Department of Nuclear Engineering, 50 UNIST-gil, Eonyang-eup, Ulju-gun, Ulsan, 689-798 (Korea, Republic of)

    2015-11-15

    Deformation of fuel particles and mass transfer from the transverse end of fuel meat toward the meat center was observed. This caused plate thickness peaking at a location between the meat edge and the meat center. The underlying mechanism for this fuel volume transport is believed to be fission induced creep of the U–Mo/Al meat. Fuel meat swelling was measured using optical microscopy images of the cross sections of the irradiated test plates. The time-dependent meat swelling was modeled for use in numerical simulation. A distinctive discrepancy between the predicted and measured meat thickness was found at the meat ends, which was assumed to be due to creep-induced mass relocation from the meat end to the meat center region that was not considered in the meat swelling model. ABAQUS FEA simulation was performed to reproduce the observed phenomenon at the meat ends. Through the simulation, we obtained the effective creep rate constants for the interaction layers (IL) and aluminum matrix. In addition, we obtained the corresponding stress and strain analysis results that can be used to understand mechanical behavior of U–Mo/Al dispersion fuel.

  1. Influence of fuel-matrix interaction on the breakaway swelling of U-Mo dispersion fuel in Al

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, Ho Jin [Dept. of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of); Kim, Yeon Soo [Nuclear Engineering Division, Argonne National Laboratory, Arogonne (United States)

    2014-04-15

    In order to advance understanding of the breakaway swelling behavior of U-Mo/Al dispersion fuel under a high-power irradiation condition, the effects of fuel-matrix interaction on the fuel performance of U-Mo/Al dispersion fuel were investigated. Fission gas release into large interfacial pores between interaction layers and the Al matrix was analyzed using both mechanistic models and observations of the post-irradiation examination results of U-Mo dispersion fuels. Using the model predictions, advantageous fuel design parameters are recommended to prevent breakaway swelling.

  2. Properties of U3Si2-Al dispersion fuel element and its application

    International Nuclear Information System (INIS)

    Yin Changgeng

    2001-01-01

    The properties of U 3 Si 2 fuel and U 3 Si 2 -Al dispersion fuel element are introduced, which include U-loading; the banding quality, U-homogeneity and 'dog-bone' phenomenon, the minimum thickness of cladding and the corrosion performances. The fabrication technique of fuel elements, NDT for fuel plates, assemble technique of fuel elements and the application of U 3 Si 2 -Al dispersion fuel elements in the world are introduced

  3. Contribuciones al diseño e implementación de un sistema de alta resolución para tomografía por emisión

    OpenAIRE

    Guerra Gutiérrez, Pedro

    2011-01-01

    La tomografía por emisión combina biología, física y computación para dar lugar a imágenes del organismo que en última instancia se relacionan con el comportamiento celular, habiendo demostrado ser una técnica de gran interés en oncología, neurología y radiología, tanto en investigación como en rutina clínica. La técnica se fundamenta en la detección de la radiación gamma generada por un radiofármaco que previamente se ha inyectado al paciente, para lo cual el equipo de tomografía dispone un ...

  4. Contribuciones de la neurociencia cognitiva al diseño de políticas científicas y sociales para niños en situación de pobreza

    Directory of Open Access Journals (Sweden)

    Sebastián Javier Lipina

    2011-01-01

    Full Text Available Los procesos de globalización y sus demandas de competitividad incrementan en forma continua las presiones educativas y laborales, así como las demandas familiares en el cuidado de niños y ancianos. En países con mayor incidencia de pobreza, ello incrementa la probabilidad de que diferentes factores de riesgo a nivel de la salud física y del desarrollo social, cognitivo y afectivo, impacten sobre el capital mental de sus poblaciones. Un aspecto crítico para las políticas sociales y científicas es que dado que la pobreza tiende a replicarse de forma intergeneracional, parte de lo que se transmite de padres a hijos son carencias en la estimulación cognitiva y emocional. Durante la última década, la neurociencia cognitiva generó un cuerpo de información que propone contribuir al desarrollo de estrategias de intervención, orientadas a mejorar las oportunidades de desarrollo del capital mental de aquellas poblaciones en condiciones de riesgo social.

  5. Energy conservation and contribution to the sustained development through action in the bioclimate design; Ahorro de energia y contribucion al desarrollo sustentable a partir de acciones de diseno bioclimatico

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Chavez, J. R.; Dorantes Rodriguez, R. [Universidad Autonoma Metropolitana, Unidad Azcapotzalco, Mexico, D. F. (Mexico)

    1995-12-31

    , construction and monitoring of the functioning of cooling passive systems. The results obtained to date point out that the energy consumption has diminished and improved the environmental comfort conditions for the library building users. [Espanol] La crisis mundial de energia de 1973, ademas de los problemas de abastecimiento y elevacion de precios, propicio tambien diversos paises, una reaccion orientada al uso eficiente y conservacion de la energia, y a la aplicacion de una arquitectura con sentido comun: la ARQUITECTURA BIOCLIMATICA, misma que se basa en la utilizacion en las edificaciones de las energias alternativas, tales como la solar eolica, etc. Obtencion de condiciones de confort natural ambiental y ahorro y uso eficiente de la energia en los edificios, son los objetivos fundamentales de la ARQUITECTURA BIOCLIMATICA. Bajo estas consideraciones, se han planteado diversos sistemas pasivos para control termico de edificios, los cuales se han aplicado en diferentes regiones climaticas del planeta. En el presente trabajo, se presenta y analiza el potencial de medidas para ahorro de energia, tales como sistemas de iluminacion artificial de alta eficiencia y sistemas pasivos de enfriamiento para el control termico de un edificio educativo, la biblioteca central de la Universidad Autonoma Metropolitana, Unidad Azcapotzalco, ubicada en la ciudad de Mexico. El objetivo de este estudio se orienta a la reduccion del consumo de energia en la biblioteca, y a la obtencion de condiciones de confort ambiental higrotermico para sus ocupantes. Estudios realizados durante la primera etapa de investigacion, han permitido identificar un excesivo consumo de energia y condiciones de falta de confort higrotermico y de la necesaria calidad del aire interior en la biblioteca. Estas acciones se han enfocado en dos aspectos. El primero se refiere al mejoramiento de la operacion de la instalacion electrica y el alumbrado de la biblioteca. Estas acciones se basaron en la sustitucion de lamparas

  6. Energy conservation and contribution to the sustained development through action in the bioclimate design; Ahorro de energia y contribucion al desarrollo sustentable a partir de acciones de diseno bioclimatico

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Chavez, J R; Dorantes Rodriguez, R [Universidad Autonoma Metropolitana, Unidad Azcapotzalco, Mexico, D. F. (Mexico)

    1996-12-31

    , construction and monitoring of the functioning of cooling passive systems. The results obtained to date point out that the energy consumption has diminished and improved the environmental comfort conditions for the library building users. [Espanol] La crisis mundial de energia de 1973, ademas de los problemas de abastecimiento y elevacion de precios, propicio tambien diversos paises, una reaccion orientada al uso eficiente y conservacion de la energia, y a la aplicacion de una arquitectura con sentido comun: la ARQUITECTURA BIOCLIMATICA, misma que se basa en la utilizacion en las edificaciones de las energias alternativas, tales como la solar eolica, etc. Obtencion de condiciones de confort natural ambiental y ahorro y uso eficiente de la energia en los edificios, son los objetivos fundamentales de la ARQUITECTURA BIOCLIMATICA. Bajo estas consideraciones, se han planteado diversos sistemas pasivos para control termico de edificios, los cuales se han aplicado en diferentes regiones climaticas del planeta. En el presente trabajo, se presenta y analiza el potencial de medidas para ahorro de energia, tales como sistemas de iluminacion artificial de alta eficiencia y sistemas pasivos de enfriamiento para el control termico de un edificio educativo, la biblioteca central de la Universidad Autonoma Metropolitana, Unidad Azcapotzalco, ubicada en la ciudad de Mexico. El objetivo de este estudio se orienta a la reduccion del consumo de energia en la biblioteca, y a la obtencion de condiciones de confort ambiental higrotermico para sus ocupantes. Estudios realizados durante la primera etapa de investigacion, han permitido identificar un excesivo consumo de energia y condiciones de falta de confort higrotermico y de la necesaria calidad del aire interior en la biblioteca. Estas acciones se han enfocado en dos aspectos. El primero se refiere al mejoramiento de la operacion de la instalacion electrica y el alumbrado de la biblioteca. Estas acciones se basaron en la sustitucion de lamparas

  7. Contribuciones al conocimiento de la flora de navarra

    Directory of Open Access Journals (Sweden)

    BALDA, Angel

    2002-01-01

    Full Text Available Nuevos datos acerca de 58 táxones de plantas de interés, bien por su rareza en el terrirorio navarro o por la ampliación de área que suponen. De ellos, 12 se citan por primera vez para Navarra : Epilobium angustifolium, Fraxinus pennylvanica, Galinsoga quadriradiata, Gamochaeta falcata, Isatis tinctoria subsp. tinctoria, Ludwigia palustris, Lycopodeilla inundata, Pseudorchis albida, Ramonda myconi, Rynchospora alba, Rynchospora fusca y Spiranthes aestivalis

  8. Contribuciones de Sir Roland Fisher a la Estadística Genética

    Directory of Open Access Journals (Sweden)

    Jaime Cuadros

    2004-11-01

    Full Text Available Sir Ronald Fisher (18901962 fue profesor de genética y muchas de sus innovaciones estadísticas encontraron expresión en el desarrollo de metodología en estadística genética. Sin embargo, mientras sus contribuciones en estadística matemática son fácilmente identificadas, en genética de poblaciones compartió su supremacía con Sewall Wright (1889 1988 y J. S. S. Haldane (1892 1965. Este documento muestra algunas de las mejores contribuciones de Fisher a las bases de la estadística genética, y sus interacciones con Wright y Haldane, los cuales contribuyeron al desarrollo del tema. Con la tecnología moderna, tanto la metodología la estadística como la información genética están cambiando. No obstante, muchos de los trabajos de Fisher permanecen relevantes, y pueden aun servir como una base para investigaciones futuras en el análisis estadístico de datos de DNA. El trabajo de este autor refleja su visión del papel de Ia estadística en Ia inferencia científica expresada en 1949

  9. Tensile mechanical properties of U3Si2-Al fuel plate

    International Nuclear Information System (INIS)

    Xu Yong; Hu Huawei; Zhuang Hongquan; Wang Xishu

    2003-01-01

    The fuel plate made of fuel meat, with the U 3 Si 2 -Al dispersion fuel center, and 6061 Al alloy cladding, is a new kind of fuel used in research reactors. The mechanical property data of the fuel meat is the basic data in the design of fuel group, but the mechanical property of this fuel meat has not been studied all over the world till now. In this paper, the mechanical properties of U 3 Si 2 -Al fuel meats of different sizes used in research reactors are investigated and analyzed, and at the same time the carrying capacity of tensile in different directions are also compared. In order to get more knowledge about the mechanical properties of the fuel meat, the tensile experiment has been carried out repeatedly. Considering the lower ratio of elongation and the brittleness, the microscope has been used to examine the zone of fracture after tensile test. (authors)

  10. Modelling of U-Mo/Al Dispersion fuel fission induced swelling and creep

    International Nuclear Information System (INIS)

    Jeong, Gwan Yoon; Sohn, Dong Seong; Kim, Yeon Soo

    2014-01-01

    In a Dispersion fuel which U-Mo particles are dispersed in Al metal matrix, a similar phenomenon forming a bulge region was observed but it is difficult to quantify and construct a model for explaining creep and swelling because of its complex microstructure change during irradiation including interaction layer (IL) and porosity formation. In a Dispersion fuel meat, fission product induces fuel particles swelling and it has to be accommodated by the deformation of the Al matrix and newly formed IL during irradiation. Then, it is reasonable that stress from fuel swelling in the complex structure should be relaxed by local adjustments of particles, Al matrix, and IL. For analysis of U-Mo/Al Dispersion fuel creep, the creep of U-Mo particle, Al matrix, and IL should be considered. Moreover, not only fuel particle swelling and IL growth, but also fuel and Al matrix consumptions due to IL formation are accounted in terms of their volume fraction changes during irradiation. In this work, fuel particles, Al matrix and IL are treated in a way of homogenized constituents: Fuel particles, Al matrix and IL consist of an equivalent meat during irradiation. Meat volume swelling of two representative plates was measured: One (Plate A) was a pure Al matrix with 6g/cc uranium loading, the other (Plate B) a silicon added Al matrix with 8g/cc uranium loading. The meat swelling of calculated as a function of burnup. The meat swelling of calculation and measurement was compared and the creep rate coefficients for Al and IL were estimated by repetitions. Based on assumption that only the continuous phase of Al-IL combined matrix accommodated the stress from fuel particle swelling and it was allowed to have creep deformation, the homogenization modeling was performed. The meat swelling of two U-Mo/Al Dispersion fuel plates was modeled by using homogenization model

  11. Modelling of U-Mo/Al Dispersion fuel fission induced swelling and creep

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Gwan Yoon; Sohn, Dong Seong [Ulsan National Institute of Science and Technology, Ulsan (Korea, Republic of); Kim, Yeon Soo [Argonne National Laboratory, Argonne (United States)

    2014-05-15

    In a Dispersion fuel which U-Mo particles are dispersed in Al metal matrix, a similar phenomenon forming a bulge region was observed but it is difficult to quantify and construct a model for explaining creep and swelling because of its complex microstructure change during irradiation including interaction layer (IL) and porosity formation. In a Dispersion fuel meat, fission product induces fuel particles swelling and it has to be accommodated by the deformation of the Al matrix and newly formed IL during irradiation. Then, it is reasonable that stress from fuel swelling in the complex structure should be relaxed by local adjustments of particles, Al matrix, and IL. For analysis of U-Mo/Al Dispersion fuel creep, the creep of U-Mo particle, Al matrix, and IL should be considered. Moreover, not only fuel particle swelling and IL growth, but also fuel and Al matrix consumptions due to IL formation are accounted in terms of their volume fraction changes during irradiation. In this work, fuel particles, Al matrix and IL are treated in a way of homogenized constituents: Fuel particles, Al matrix and IL consist of an equivalent meat during irradiation. Meat volume swelling of two representative plates was measured: One (Plate A) was a pure Al matrix with 6g/cc uranium loading, the other (Plate B) a silicon added Al matrix with 8g/cc uranium loading. The meat swelling of calculated as a function of burnup. The meat swelling of calculation and measurement was compared and the creep rate coefficients for Al and IL were estimated by repetitions. Based on assumption that only the continuous phase of Al-IL combined matrix accommodated the stress from fuel particle swelling and it was allowed to have creep deformation, the homogenization modeling was performed. The meat swelling of two U-Mo/Al Dispersion fuel plates was modeled by using homogenization model.

  12. Study on the irradiation swelling of U3Si2-Al dispersion fuel

    International Nuclear Information System (INIS)

    Xing Zhonghu; Ying Shihao

    2001-01-01

    The dominant modeling mechanisms on irradiation swelling of U 3 Si 2 -Al dispersion fuel are introduced. The core of dispersion fuel is looked to as micro-fuel elements of continuous matrix. The formation processes of gas bubbles in the fuel phase are described through the behavior mechanisms of fission gases. The swelling in the fuel phase causes the interaction between fuel particles and metal matrix, and the metal matrix can restrain the irradiation swelling of fuel particles. The developed code can predict irradiation-swelling values according to the parameters of fuel elements and irradiation conditions, and the predicted values are in agreement with the measured results

  13. Status of U3Si2-Al fuel development in China

    International Nuclear Information System (INIS)

    Sun Rongxian; Huang Dechen; Yin Changgeng; Zhang Qindi; He Fengqi; Li Shuhua; Xiang Xingbi; Zhang Zhiyi; Wang Zhaoyue

    1995-01-01

    On the basis of the research and development work, a production line of U 3 Si 2 -Al dispersion fuel elements has been established and tens of the fuel elements have been produced. A lot of technical improvements and reliable inspection system ensure that all technical performance of the fuel elements meet International standards. (author)

  14. Corrosion and protection of spent Al-clad research reactor fuel during extended wet storage

    International Nuclear Information System (INIS)

    Ramanathan, Lalgudi V.

    2009-01-01

    A variety of spent research reactor fuel elements with different fuel meats, geometries and 235 U enrichments are presently stored under water in basins throughout the world. More than 90% of these fuels are clad in aluminum (Al) or its alloy and are susceptible to corrosion. This paper presents an overview of the influence of Al alloy composition, galvanic effects (Al alloy/stainless steel), crevice effects, water parameters and synergism between these parameters as well as settled solids on the corrosion of typical Al alloys used as fuel element cladding. Pitting is the main form of corrosion and is affected by water conductivity, chloride ion content, formation of galvanic couples with rack supports and settled solid particles. The extent to which these parameters influence Al corrosion varies. This paper also presents potential conversion coatings to protect the spent fuel cladding. (author)

  15. Modeling a failure criterion for U-Mo/Al dispersion fuel

    Science.gov (United States)

    Oh, Jae-Yong; Kim, Yeon Soo; Tahk, Young-Wook; Kim, Hyun-Jung; Kong, Eui-Hyun; Yim, Jeong-Sik

    2016-05-01

    The breakaway swelling in U-Mo/Al dispersion fuel is known to be caused by large pore formation enhanced by interaction layer (IL) growth between fuel particles and Al matrix. In this study, a critical IL thickness was defined as a criterion for the formation of a large pore in U-Mo/Al dispersion fuel. Specifically, the critical IL thickness is given when two neighboring fuel particles come into contact with each other in the developed IL. The model was verified using the irradiation data from the RERTR tests and KOMO-4 test. The model application to full-sized sample irradiations such as IRISs, FUTURE, E-FUTURE, and AFIP-1 tests resulted in conservative predictions. The parametric study revealed that the fuel particle size and the homogeneity of the fuel particle distribution are influential for fuel performance.

  16. Modeling a failure criterion for U–Mo/Al dispersion fuel

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Jae-Yong, E-mail: tylor@kaeri.re.kr [Korea Atomic Energy Research Institute, 111, Daedeok-Daero 989 Beon-Gil, Yuseong-Gu, Daejeon 305-353 (Korea, Republic of); Kim, Yeon Soo [Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 (United States); Tahk, Young-Wook; Kim, Hyun-Jung; Kong, Eui-Hyun; Yim, Jeong-Sik [Korea Atomic Energy Research Institute, 111, Daedeok-Daero 989 Beon-Gil, Yuseong-Gu, Daejeon 305-353 (Korea, Republic of)

    2016-05-15

    The breakaway swelling in U–Mo/Al dispersion fuel is known to be caused by large pore formation enhanced by interaction layer (IL) growth between fuel particles and Al matrix. In this study, a critical IL thickness was defined as a criterion for the formation of a large pore in U–Mo/Al dispersion fuel. Specifically, the critical IL thickness is given when two neighboring fuel particles come into contact with each other in the developed IL. The model was verified using the irradiation data from the RERTR tests and KOMO-4 test. The model application to full-sized sample irradiations such as IRISs, FUTURE, E-FUTURE, and AFIP-1 tests resulted in conservative predictions. The parametric study revealed that the fuel particle size and the homogeneity of the fuel particle distribution are influential for fuel performance.

  17. Scanning electron microscopy analysis of fuel/matrix interaction layers in highly-irradiated U-Mo dispersion fuel plates with Al and Al-Si alloy matrices

    Energy Technology Data Exchange (ETDEWEB)

    Keiser, Dennis D. Jr; Jue, Jan Fong; Miller, Brandon D.; Gan, Jian; Robinson, Adom B.; Medvedev, Pavel; Madden, James; Wachs, Dan; Meyer, Mitch [Nuclear Fuels and Materials Division, Idaho National Laboratory (United States)

    2014-04-15

    In order to investigate how the microstructure of fuel/matrix-interaction (FMI) layers change during irradiation, different U-7Mo dispersion fuel plates have been irradiated to high fission density and then characterized using scanning electron microscopy (SEM). Specifically, samples from irradiated U-7Mo dispersion fuel elements with pure Al, Al-2Si and AA4043 (-4.5 wt.%Si) matrices were SEM characterized using polished samples and samples that were prepared with a focused ion beam (FIB). Features not observable for the polished samples could be captured in SEM images taken of the FIB samples. For the Al matrix sample, a relatively large FMI layer develops, with enrichment of Xe at the FMI layer/Al matrix interface and evidence of debonding. Overall, a significant penetration of Si from the FMI layer into the U-7Mo fuel was observed for samples with Si in the Al matrix, which resulted in a change of the size (larger) and shape (round) of the fission gas bubbles. Additionally, solid fission product phases were observed to nucleate and grow within these bubbles. These changes in the localized regions of the microstructure of the U-7Mo may contribute to changes observed in the macroscopic swelling of fuel plates with Al-Si matrices.

  18. Study on characteristics of U-Mo/Al-Si interaction layers of dispersion fuel plates

    International Nuclear Information System (INIS)

    Liu Lijian; Yin Changgeng; Chen Jiangang; Sun Changlong; Liu Yunming

    2014-01-01

    In this paper, we analyzed the characteristics of U-Mo/Al-Si interaction layers of dispersion fuel plates. The results show that the interaction layers (IL) are with irregular morphology and uneven thickness, and are mainly formed in the internal micro cracks of the dispersion fuel particles or at the interface between the particles and the substrates. The diffusion mechanism of U-Mo/Al-Si is the vacancy diffusion, Al and Si are migrating elements, and the diffusion reaction is that Al and Si diffuse to U-Mo alloy. Inside the interaction layers, the Al content keeps constant basically, but the Si content gradually increases with the substrate-fuel direction, and the maximum content of Si appears interaction layers near the U-Mo side. Adding about 5 wt% Si into Al matrix can restrain the diffusion reaction, and improve the performance of dispersion fuel plates finally. (authors)

  19. Microstructure of the irradiated U 3Si 2/Al silicide dispersion fuel

    Science.gov (United States)

    Gan, J.; Keiser, D. D.; Miller, B. D.; Jue, J.-F.; Robinson, A. B.; Madden, J. W.; Medvedev, P. G.; Wachs, D. M.

    2011-12-01

    The silicide dispersion fuel of U 3Si 2/Al is recognized as the best performance fuel for many nuclear research and test reactors with up to 4.8 gU/cm 3 fuel loading. An irradiated U 3Si 2/Al dispersion fuel ( 235U ˜ 75%) from the high-flux side of a fuel plate (U0R040) from the Reduced Enrichment for Research and Test Reactors (RERTR)-8 test was characterized using transmission electron microscopy (TEM). The fuel was irradiated in the Advanced Test Reactor (ATR) for 105 days. The average irradiation temperature and fission density of the U 3Si 2 fuel particles for the TEM sample are estimated to be approximately 110 °C and 5.4 × 10 27 f/m 3. The characterization was performed using a 200-kV TEM. The U/Si ratio for the fuel particle and (Si + Al)/U for the fuel-matrix-interaction layer are approximately 1.1 and 4-10, respectively. The estimated average diameter, number density and volume fraction for small bubbles (<1 μm) in the fuel particle are ˜94 nm, 1.05 × 10 20 m -3 and ˜11%, respectively. The results and their implication on the performance of the U 3Si 2/Al silicide dispersion fuel are discussed.

  20. The Effect of Uncertainties on the Operating Temperature of U-Mo/Al Dispersion Fuel

    Energy Technology Data Exchange (ETDEWEB)

    Sweidana, Faris B.; Mistarihia, Qusai M.; Ryu Ho Jin [KAIST, Daejeon (Korea, Republic of); Yim, Jeong Sik [KAERI, Daejeon (Korea, Republic of)

    2016-05-15

    In this study, uncertainty and combined uncertainty studies have been carried out to evaluate the uncertainty of the parameters affecting the operational temperature of U-Mo/Al fuel. The uncertainties related to the thermal conductivity of fuel meat, which consists of the effects of thermal diffusivity, density and specific heat capacity, the interaction layer (IL) that forms between the dispersed fuel and the matrix, fuel plate dimensions, heat flux, heat transfer coefficient and the outer cladding temperature were considered. As the development of low-enriched uranium (LEU) fuels has been pursued for research reactors to replace the use of highly-enriched uranium (HEU) for the improvement of proliferation resistance of fuels and fuel cycle, U-Mo particles dispersed in an Al matrix (UMo/Al) is a promising fuel for conversion of the research reactors that currently use HEU fuels to LEUfueled reactors due to its high density and good irradiation stability. Several models have been developed for the estimation of the thermal conductivity of U–Mo fuel, mainly based on the best fit of the very few measured data without providing uncertainty ranges. The purpose of this study is to provide a reasonable estimation of the upper bounds and lower bounds of fuel temperatures with burnup through the evaluation of the uncertainties in the thermal conductivity of irradiated U-Mo/Al dispersion fuel. The combined uncertainty study using RSS method evaluated the effect of applying all the uncertainty values of all the parameters on the operational temperature of U-Mo/Al fuel. The overall influence on the value of the operational temperature is 16.58 .deg. C at the beginning of life and it increases as the burnup increases to reach 18.74 .deg. C at a fuel meat fission density of 3.50E+21 fission/cm{sup 3}. Further studies are needed to evaluate the behavior more accurately by including other parameters uncertainties such as the interaction layer thermal conductivity.

  1. The Fabrication Problem Of U3Si2-Al Fuel With Uranium High Loading

    International Nuclear Information System (INIS)

    Supardjo

    1996-01-01

    The quality of U 3 Si 2 -Al dispersion fuel product is the main aim for each fabricator. Low loading of uranium fuel element is easily fabricated, but with the increased, uranium loading, homogeneity of uranium distribution is difficult to achieve and it always formed white spots, blister, and dogboning in the fuel plates. The problem can be eliminated by the increasing treatment of the fuel/Al powder. The precise selection of fuel/Al particles diameter is needed indeed to make easier in the homogeneous process of powder and the porosities arrangement in the fuel plates. The increasing of uranium loading at constant meat thickness will increase the meat hardness, therefore to withdraw the dogboning forming, the use of harder cladding materials is necessity

  2. A review of microstructural analysis on U3Si2-Al plate-type fuel

    International Nuclear Information System (INIS)

    Ti Zhongxin; Guo Yibai

    1995-12-01

    The microstructure of U 3 Si 2 -Al plate-type fuel, that is the microstructure of fuel particles, compatibility of the fuel particles and Al matrix, fuel particles distribution, dogbone area morphology, clad and meat thickness, bone quality of clad/frame and clad/fuel core, and the effect of these factors on products quality were comprehensively investigated and analyzed by means of optical microscopy (OM), scanning electron microscopy (SEM), X-ray diffraction (XRD), energy dispersive X-ray spectrometry (EDX), image processing technique, etc.. The main results are as following: U-7.7%Si alloy contains two phases: primary U 3 Si 2 and small amount of USi (about 12%), free-uranium was not detected in fuel particles; the dogbone area is the key factor affecting fuel plate quality (1 ref., 16 figs., 4 tabs.)

  3. Transmission electron microscopy characterization of irradiated U-7Mo/Al-2Si dispersion fuel

    International Nuclear Information System (INIS)

    Gan, J.; Keiser, D.D.; Wachs, D.M.; Robinson, A.B.; Miller, B.D.; Allen, T.R.

    2010-01-01

    The plate-type dispersion fuels, with the atomized U(Mo) fuel particles dispersed in the Al or Al alloy matrix, are being developed for use in research and test reactors worldwide. It is found that the irradiation performance of a plate-type dispersion fuel depends on the radiation stability of the various phases in a fuel plate. Transmission electron microscopy was performed on a sample (peak fuel mid-plane temperature ∼109 deg. C and fission density ∼4.5 x 10 27 f m -3 ) taken from an irradiated U-7Mo dispersion fuel plate with Al-2Si alloy matrix to investigate the role of Si addition in the matrix on the radiation stability of the phase(s) in the U-7Mo fuel/matrix interaction layer. A similar interaction layer that forms in irradiated U-7Mo dispersion fuels with pure Al matrix has been found to exhibit poor irradiation stability, likely as a result of poor fission gas retention. The interaction layer for both U-7Mo/Al-2Si and U-7Mo/Al fuels is observed to be amorphous. However, unlike the latter, the amorphous layer for the former was found to effectively retain fission gases in areas with high Si concentration. When the Si concentration becomes relatively low, the fission gas bubbles agglomerate into fewer large pores. Within the U-7Mo fuel particles, a bubble superlattice ordered as fcc structure and oriented parallel to the bcc metal lattice was observed where the average bubble size and the superlattice constant are 3.5 nm and 11.5 nm, respectively. The estimated fission gas inventory in the bubble superlattice correlates well with the fission density in the fuel.

  4. Influence of Fuel Meat Porosity on Heat Capacities of Fuel Element Plate U3Si2-Al

    International Nuclear Information System (INIS)

    Ginting, Aslina Br.; Supardjo; Sutri Indaryati

    2007-01-01

    Analyze of heat capacities of Al powder, AIMg 2 cladding, U 3 Si 2 powder and PEB U 3 Si 2 -Al with the meat porosity of 4.9; 5.53 ; 6.25 ; 6.95 %; 7.90; 8.66% have been done. Analysis was conducted by using Differential Scanning Calorimeter (DSC) at temperature 30℃ to 450℃ with heating rate 1℃ /minute in Argon gas media. The purpose of analyze is to know the influence of increasing of fuel meat porosity on heat capacities because increasing of percentage of meat porosity will cause degradation the of heat capacities of PEB U 3 Si 2 -Al. Result of analysis showed that the heat capacities of Al powder, AIMg 2 cladding increase by temperature, while heat capacities of U 3 Si 2 powder was stable with increasing of temperature up to 450℃. Analysis of heat capacities toward PEB U 3 Si 2 -Al indicate that increasing of fuel meat porosity of caused degradation of the heat capacities of PEB U 3 Si 2 -Al. Data obtained were expected to serve the purpose of input to fabricator of research reactor fuel in for design of fuel element type silicide with high loading. (author)

  5. The improvement of technology for high-uranium-density Al-base dispersion fuel plates

    International Nuclear Information System (INIS)

    Shouhui, Dai; Rongxian, Sun; Hejian, Mao; Baosheng, Zhao; Changgen, Yin

    1987-01-01

    An improved rolling process was developed for manufacturing Al-base dispersion fuel plates. When the fuel content in the meat increased up to 50 vol%, the non-uniformity of uranium is not more than ± 7.2%, and the minimum cladding thickness is not less than 0.32 mm. (Author)

  6. High-uranium-loaded U3O8--Al fuel element development program

    International Nuclear Information System (INIS)

    Martin, M.M.

    1978-01-01

    The High-Uranium-Loaded U 3 O 8 --Al Fuel Development Program supports Argonne National Laboratory efforts to develop high-uranium-density research and test reactor fuel to accommodate use of low-uranium enrichment. The goal is to fuel most research and test reactors with uranium of less than 20% enrichment for the purpose of lowering the potential for diversion of highly-enriched material for nonpeaceful usages

  7. Predicted irradiation behavior of U3O8-Al dispersion fuels for production reactor applications

    International Nuclear Information System (INIS)

    Cronenberg, A.W.; Rest, J.

    1990-01-01

    Candidate fuels for the new heavy-water production reactor include uranium/aluminum alloy and U 3 O 8 -Al dispersion fuels. The U 3 O 8 -Al dispersion fuel would make possible higher uranium loadings and would facilitate uranium recycle. Research efforts on U 3 O 8 -Al fuel include in-pile irradiation studies and development of analytical tools to characterize the behavior of dispersion fuels at high-burnup. In this paper the irradiation performance of U 3 O 8 -Al is assessed using the mechanistic Dispersion Analysis Research Tool (DART) code. Predictions of fuel swelling and alteration of thermal conductivity are presented and compared with experimental data. Calculational results indicate good agreement with available data where the effects of as-fabricated porosity and U 3 O 8 -Al oxygen exchange reactions are shown to exert a controlling influence on irradiation behavior. The DART code is judged to be a useful tool for assessing U 3 O 8 -Al performance over a wide range of irradiation conditions

  8. Biomethane as a fuel. Quota transfer; Biomethan als Kraftstoff. Quotenuebertragung

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-07-15

    Biomethane from biomass replaces fossil natural gas. Just as natural gas, it can be easily used in the transport sector. The advantages of biomethane as a fuel are numerous: high contribution to climate protection, technically acceptable admixture, price advantage over gasoline, eligibility to the biofuel quota. This brochure provides information on: (a) Role of biomethane to meet the biofuel targets of the Federal Government; (b) Eligibility of biomethane to the biofuel quota; (c) Business models for marketing of biomethane as a fuel; (d) Benefits of bio-methane for various actors.

  9. Fuel Performance Calculations for FeCrAl Cladding in BWRs

    Energy Technology Data Exchange (ETDEWEB)

    George, Nathan [Univ. of Tennessee, Knoxville, TN (United States). Dept. of Nuclear Engineering; Sweet, Ryan [Univ. of Tennessee, Knoxville, TN (United States). Dept. of Nuclear Engineering; Maldonado, G. Ivan [Univ. of Tennessee, Knoxville, TN (United States). Dept. of Nuclear Engineering; Wirth, Brian D. [Univ. of Tennessee, Knoxville, TN (United States). Dept. of Nuclear Engineering; Powers, Jeffrey J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Worrall, Andrew [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-01-01

    This study expands upon previous neutronics analyses of the reactivity impact of alternate cladding concepts in boiling water reactor (BWR) cores and directs focus toward contrasting fuel performance characteristics of FeCrAl cladding against those of traditional Zircaloy. Using neutronics results from a modern version of the 3D nodal simulator NESTLE, linear power histories were generated and supplied to the BISON-CASL code for fuel performance evaluations. BISON-CASL (formerly Peregrine) expands on material libraries implemented in the BISON fuel performance code and the MOOSE framework by providing proprietary material data. By creating material libraries for Zircaloy and FeCrAl cladding, the thermomechanical behavior of the fuel rod (e.g., strains, centerline fuel temperature, and time to gap closure) were investigated and contrasted.

  10. FeCrAl/Zr dual layer fuel cladding for improved safety margin under accident scenario

    International Nuclear Information System (INIS)

    Park, D.J.; Park, J.H.; Jung, Y.I.; Kim, H.G.; Park, J.Y.; Koo, Y.H.

    2014-01-01

    For application of advanced steel as a cladding material in light water reactor (LWR), FeCrAl/Zr dual layer tube was manufactured by using a hot isostatic pressing (HIP) method. To optimize HIP condition for joining both FeCrAl and Zr alloys, HIP was carried out under various temperature conditions. Tensile test and 3-point bend test performed for measuring mechanical properties of HIPed sample. To better understand microstructural characteristics in interface region between two alloys, SEM and TEM study were conducted by using HIPed sample with different process conditions. Based on this optimization study and analyzed results, optimized HIP condition was determined and FeCrAl/Zr dual layer fuel cladding having same wall thickness with current LWR fuel cladding was manufactured. Simulated loss-of-coolant accident test was carried out using FeCrAl/Zr dual layer cladding sample and fuel integrity was measured by mechanical test. (authors)

  11. Manufacture of hypoeutectic Al-Si metal powders for dispersion matriz in nuclear fuels

    International Nuclear Information System (INIS)

    Raffaeli, H A; Harri, S; Acosta, M; Castillo Guerra, R; Rossi, G; Fabro, J O; Rubiolo, G H

    2012-01-01

    Within the framework of the development of low enriched nuclear fuels for research reactors, U.Mo/Al is the most promising option that has however to be optimized. Indeed at the U.Mo/Al interfaces between U.Mo particles and the Al matrix, an interaction layer grows under irradiation inducing an unacceptable fuel swelling. Adding silicon in limited content into the Al matrix has clearly improved the in-pile fuel behaviour. This breakthrough is attributed to an U.Mo/Al.Si protective layer around U.Mo particles appeared during fuel manufacturing. The present work deals with three techniques applied to produce metal powders of hypoeutectic Al-Si alloys: ball milling, centrifugal atomization and gas atomization. Size and microstructure of the particles are analyzed in the three techniques. The best result is found with the gas atomization system, flakes and rods morphology predominates in the produced powders, with particle sizes below 150 microns and the greater mass population (65%) is between 150 and 125 microns. The particle surface is smooth and the high solidification rate provides a good distribution of the α-Al primary and eutectic phase within each particle (author)

  12. BISON Fuel Performance Analysis of FeCrAl cladding with updated properties

    Energy Technology Data Exchange (ETDEWEB)

    Sweet, Ryan [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); George, Nathan M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Terrani, Kurt A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Wirth, Brian [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-08-30

    In order to improve the accident tolerance of light water reactor (LWR) fuel, alternative cladding materials have been proposed to replace zirconium (Zr)-based alloys. Of these materials, there is a particular focus on iron-chromium-aluminum (FeCrAl) alloys due to much slower oxidation kinetics in high-temperature steam than Zr-alloys. This should decrease the energy release due to oxidation and allow the cladding to remain integral longer in the presence of high temperature steam, making accident mitigation more likely. As a continuation of the development for these alloys, suitability for normal operation must also be demonstrated. This research is focused on modeling the integral thermo-mechanical performance of FeCrAl-cladded fuel during normal reactor operation. Preliminary analysis has been performed to assess FeCrAl alloys (namely Alkrothal 720 and APMT) as a suitable fuel cladding replacement for Zr-alloys, using the MOOSE-based, finite-element fuel performance code BISON and the best available thermal-mechanical and irradiation-induced constitutive properties. These simulations identify the effects of the mechanical-stress and irradiation response of FeCrAl, and provide a comparison with Zr-alloys. In comparing these clad materials, fuel rods have been simulated for normal reactor operation and simple steady-state operation. Normal reactor operating conditions target the cladding performance over the rod lifetime (~4 cycles) for the highest-power rod in the highest-power fuel assembly under reactor power maneuvering. The power histories and axial temperature profiles input into BISON were generated from a neutronics study on full-core reactivity equivalence for FeCrAl using the 3D full core simulator NESTLE. Evolution of the FeCrAl cladding behavior over time is evaluated by using steady-state operating conditions such as a simple axial power profile, a constant cladding surface temperature, and a constant fuel power history. The fuel rod designs and

  13. Irradiation behavior of U 6Mn-Al dispersion fuel elements

    Science.gov (United States)

    Meyer, M. K.; Wiencek, T. C.; Hayes, S. L.; Hofman, G. L.

    2000-02-01

    Irradiation testing of U 6Mn-Al dispersion fuel miniplates was conducted in the Oak Ridge Research Reactor (ORR). Post-irradiation examination showed that U 6Mn in an unrestrained plate configuration performs similarly to U 6Fe under irradiation, forming extensive and interlinked fission gas bubbles at a fission density of approximately 3×10 27 m-3. Fuel plate failure occurs by fission gas pressure driven `pillowing' on continued irradiation.

  14. Post-irradiation analysis of low enriched U-Mo/Al dispersions fuel miniplate tests, RERTR 4 and 5

    International Nuclear Information System (INIS)

    Hofman, G.L.; Finlay, M.R.; Kim, Y.S.

    2005-01-01

    Interpretation of the post irradiation data of U-Mo/Al dispersion fuel mini plates irradiated in the Advanced Test Reactor to a maximum U-235 burn up of 80% are presented. The analyses addresses fuel swelling and porosity formation as these fuel performance issues relate to fuel fabrication and irradiation parameters. Specifically, mechanisms involved in the formation of porosity observed in the U-Mo/Al interaction phase are discussed and, means of mitigating or eliminating this irradiation phenomenon are offered. (author)

  15. Irradiation behavior of low-enriched U/sub 6/Fe-Al dispersion fuel elements

    Energy Technology Data Exchange (ETDEWEB)

    Hofman, G.L.; Domagala, R.F.; Copeland, G.L.

    1987-10-01

    An irradiation test of miniature fuel plates containing low-enriched (20% /sup 235/U)U/sub 6/Fe dispersed and clad in Al was performed. The postirradiation examination shows U/sub 6/Fe to form extensive fission gas bubbles at burnups of only approx. = 20% of the original 20% fuel enrichment. Plate failure by fission gas-driven pillowing occurred at approx. = 40% burnup. This places U/sub 6/FE at the lowest burnup capability among low enriched dispersion fuels that have been tested for use in research and test reactors

  16. Corrosion surveillance programme for Latin American research reactor Al-clad spent fuel in water

    International Nuclear Information System (INIS)

    Ramanathan, L.V.; Haddad, R.; Ritchie, I.

    2002-01-01

    The objectives of the IAEA sponsored Regional Technical Co-operation Project for Latin America (Argentina, Brazil, Chile, Mexico, and Peru) are to provide the basic conditions to define a regional strategy for managing spent fuel and to provide solutions, taking into consideration the economic and technological realities of the countries involved. In particular, to determine the basic conditions for managing research reactor spent fuel during operation and interim storage as well as final disposal, and to establish forms of regional cooperation in the four main areas: spent fuel characterization, safety, regulation and public communication. This paper reports the corrosion surveillance activities of the Regional Project and these are based on the IAEA sponsored co-ordinated research project (CRP) on 'Corrosion of research reactor Al-clad spent fuel in water'. The overall test consists of exposing corrosion coupon racks at different spent fuel basins followed by evaluation. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-03-15

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

  18. An investigation on the irradiation behavior of atomized U-Mo/Al dispersion rod fuels

    International Nuclear Information System (INIS)

    Park, J.M.; Ryu, H.J.; Lee, Y.S.; Lee, D.B.; Oh, S.J.; Yoo, B.O.; Jung, Y.H.; Sohn, D.S.; Kim, C.K.

    2005-01-01

    The second irradiation fuel experiment, KOMO-2, for the qualification test of atomized U-Mo dispersion rod fuels with U-loadings of 4-4.5 gU/cc at KAERI was finished after an irradiation up to 70 at% U 235 peak burn-up and subjected to the IMEF (Irradiation material Examination Facility) for a post-irradiation analysis in order to understand the fuel irradiation performance of the U-Mo dispersion fuel. Current results for PIE of KOMO-2 revealed that the U-Mo/Al dispersion fuel rods exhibited a sound performance without any break-away swelling, but most of the fuel rods irradiated at a high linear power showed an extensive formation of the interaction phase between the U-Mo particle and the Al matrix. In this paper, the analysis of the PIE results, which focused on the diffusion related microstructures obtained from the optical and EPMA (Electron Probe Micro Analysis) observations, will be presented in detail. And a thermal modeling will be carried out to calculate the temperature of the fuel rod during an irradiation. (author)

  19. Parametric study of the deformation of U3Si2-Al dispersion fuel plates

    International Nuclear Information System (INIS)

    Vieira, Edeval

    2011-01-01

    The Nuclear and Energy Research Institute - IPEN-CNEN/SP produces routinely the nuclear fuel necessary for operating its research reactor, IEA-R1. This fuel consists of fuel plates containing U 3 Si 2 -Al composites as the meat, which are fabricated by rolling. The rolling process currently deployed was developed with base on information obtained from literature, which were used as premises for defining the current manufacturing procedures, according to a methodology with essentially empirical character. Despite the current rolling process to be perfectly stable and highly reproducible, it is not well characterized and therefore is not fully known. The objective of this work is to characterize the rolling process for producing fuel plates, specifically the evolution of dimensional parameters of the fuel plate as a function of its deformation in the rolling process. Results are presented in terms of the evolution of the thickness of the fuel meat and cladding of the fuel plate along the deformation, as well as the terminals defects, microstructure and porosity of the fuel meat. (author)

  20. Corrosion on the fuel plate nucleus based on U3 O8 - Al dispersions

    International Nuclear Information System (INIS)

    Durazzo, M.

    2005-01-01

    Samples of MTR type U 3 O 8 - Al dispersion fuel plates meats were corrosion tested in deionized water at different temperatures in the range 30 to 90 deg C. In the tests the cores were exposed to the deionized water by means of an artificially produced cladding defect. The results indicate that the meat corrosion is accompanied by hydrogen evolution. (author)

  1. High-Uranium-Loaded U3O8-Al fuel element development program. Part 1

    International Nuclear Information System (INIS)

    Martin, M.M.

    1993-01-01

    The High-Uranium-Loaded U 3 O 8 -Al Fuel Element Development Program supports Argonne National Laboratory efforts to develop high-uranium-density research and test reactor fuel to accommodate use of low-uranium enrichment. The goal is to fuel most research and test reactors with uranium of less than 20% enrichment for the purpose of lowering the potential for diversion of highly-enriched material for nonpeaceful usages. The specific objective of the program is to develop the technological and engineering data base for U 3 O 8 -Al plate-type fuel elements of maximal uranium content to the point of vendor qualification for full scale fabrication on a production basis. A program and management plan that details the organization, supporting objectives, schedule, and budget is in place and preparation for fuel and irradiation studies is under way. The current programming envisions a program of about four years duration for an estimated cost of about two million dollars. During the decades of the fifties and sixties, developments at Oak Ridge National Laboratory led to the use of U 3 O 8 -Al plate-type fuel elements in the High Flux Isotope Reactor, Oak Ridge Research Reactor, Puerto Rico Nuclear Center Reactor, and the High Flux Beam Reactor. Most of the developmental information however applies only up to a uranium concentration of about 55 wt % (about 35 vol % U 3 O 8 ). The technical issues that must be addressed to further increase the uranium loading beyond 55 wt % U involve plate fabrication phenomena of voids and dogboning, fuel behavior under long irradiation, and potential for the thermite reaction between U 3 O 8 and aluminum

  2. 2nd Gen FeCrAl ODS Alloy Development For Accident-Tolerant Fuel Cladding

    Energy Technology Data Exchange (ETDEWEB)

    Dryepondt, Sebastien N. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Massey, Caleb P. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Edmondson, Philip D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-08-01

    Extensive research at ORNL aims at developing advanced low-Cr high strength FeCrAl alloys for accident tolerant fuel cladding. One task focuses on the fabrication of new low Cr oxide dispersion strengthened (ODS) FeCrAl alloys. The first Fe-12Cr-5Al+Y2O3 (+ ZrO2 or TiO2) ODS alloys exhibited excellent tensile strength up to 800 C and good oxidation resistance in steam up to 1400 C, but very limited plastic deformation at temperature ranging from room to 800 C. To improve alloy ductility, several fabrication parameters were considered. New Fe-10-12Cr-6Al gas-atomized powders containing 0.15 to 0.5wt% Zr were procured and ball milled for 10h, 20h or 40h with Y2O3. The resulting powder was then extruded at temperature ranging from 900 to 1050 C. Decreasing the ball milling time or increasing the extrusion temperature changed the alloy grain size leading to lower strength but enhanced ductility. Small variations of the Cr, Zr, O and N content did not seem to significantly impact the alloy tensile properties, and, overall, the 2nd gen ODS FeCrAl alloys showed significantly better ductility than the 1st gen alloys. Tube fabrication needed for fuel cladding will require cold or warm working associated with softening heat treatments, work was therefore initiated to assess the effect of these fabrications steps on the alloy microstructure and properties. This report has been submitted as fulfillment of milestone M3FT 16OR020202091 titled, Report on 2nd Gen FeCrAl ODS Alloy Development for the Department of Energy Office of Nuclear Energy, Advanced Fuel Campaign of the Fuel Cycle R&D program.

  3. Performance of Nb protective diffusion coating on U-Mo/Al dispersion fuel

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ji-Hyeon; Sohn, Dong-Seong [Ulsan National Institute of Science and Technology, Ulsan (Korea, Republic of); Kim, Sunghwan; Nam, Ji Min; Lee, Kyu Hong; Park, Jong Man [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-10-15

    To achieve this aim, it is necessary to increase the volume fraction of fuel particles inside the meat. However, the technical limit is reached at approximately 55 vol.% of fuel particles in the aluminum matrix. As a solution, an uranium compound with an higher uranium density than existing U3Si2 fuel has to be selected. Also alloying the uranium must stabilize γ-phase of uranium at room temperature because adequate properties of the γ -phase of uranium showed a good irradiation behavior in the past. Hence, U-Mo alloys were selected as the best candidates. The formation of interaction phase is a critical problem to apply U-Mo alloys to the high performance research reactor. Different means have been proposed to reduce the interaction between U-Mo fuel and Al matrix. There are three means. : 1. Addition of a diffusion limiting element to the matrix 2. Insertion of a diffusion barrier at the interface between the U-Mo and the Al 3. Alloying of the U-Mo with a third element Here we present the effect of Nb coating as diffusion barrier on formation of interaction layers between UMo powders and Al matrix. We present the effect of Nb coating on formation of interaction layers between U-Mo powders and Al matrix. Centrifugally atomized U-7 wt.% Mo powders were used, and Nb was coated on the surface of U-7 wt.% Mo by sputtering. Subsequently, the Nb-coated U-7 wt.% Mo powders were mixed with pure Al powders, and were made into compacts. The compacts were annealed at 550 .deg. C for 1, 3, 5 hours, respectively, and the result showed that the Nb coating on U-7 wt.% Mo effectively suppressed the growth of interaction layers between U-7 wt.% Mo and Al matrix.

  4. Study of the U3O8-Al thermite reaction and strength of reactor fuel tubes

    International Nuclear Information System (INIS)

    Peacock, H.B.

    1983-08-01

    Heating tests using 53 wt % U 3 O 8 -Al pellets show that an exothermic reaction occurs between 875 and 1000 0 C and takes 10 to 20 seconds to reach maximum temperature. The maximum temperature is a function of particle size of the U 3 O 8 with large particles exhibiting lower peak temperatures. The calculated energy release was 123 cal/g of U 3 O 8 -aluminum fuel. Tests using aluminum clad outer fuel tube sections gave lower peak temperatures than for pellets. No violent reactions occurred. The results are reasonably consistent with recent reported data indicating that the exothermic U 3 O 8 -Al reaction is not an important energy source. The compressive and tensile strengths of U 3 O 8 tubes above 660 0 C are low. In compression, sections with 2 psi average axial stress failed at 917 0 C, while sections with 7 psi failed at 669 0 C. Tubes with U-Al alloy cores failed at about 670 0 C with no applied load. The stresses in fuel tubes during a reactor transient may range up to several hundred psi and are less than 7 psi only in the upper part of the fuel tube

  5. Effect of stress evolution on microstructural behavior in U-Mo/Al dispersion fuel

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, G.Y. [Department of Nuclear Engineering, Ulsan National Institute of Science and Technology, 50 UNIST-gil, Eonyang-eup, Ulju-gun, Ulsan 689-798 (Korea, Republic of); Kim, Yeon Soo; Jamison, L.M. [Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 (United States); Robinson, A.B. [Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415-6188 (United States); Lee, K.H. [Korea Atomic Energy Research Institute, 989-111 Daedeokdaero, Yuseong-gu, Daejeon 305-353 (Korea, Republic of); Sohn, Dong-Seong, E-mail: dssohn@unist.ac.kr [Department of Nuclear Engineering, Ulsan National Institute of Science and Technology, 50 UNIST-gil, Eonyang-eup, Ulju-gun, Ulsan 689-798 (Korea, Republic of)

    2017-04-15

    U-Mo/Al dispersion fuel irradiated to high burnup at high power (high fission rate) exhibited microstructural changes including deformation of the fuel particles, pore growth, and rupture of the Al matrix. The driving force for these microstructural changes was meat swelling resulting from a combination of fuel particle swelling and interaction layer (IL) growth. In some cases, pore growth in the interaction layers also contributed to meat swelling. The main objective of this work was to determine the stress distribution within the fuel meat that caused these phenomena. A mechanical equilibrium between the stress generated by fuel meat swelling and the stress relieved by fission-induced creep in the meat constituents (U-Mo particles, Al matrix, and IL) was considered. Test plates with well-recorded fabrication data and irradiation conditions were used, and their post-irradiation examination (PIE) data was obtained. ABAQUS finite element analysis (FEA) was utilized to simulate the microstructural evolution of the plates. The simulation results allowed for the determination of effective stress and hydrostatic stress exerted on the meat constituents. The effects of fabrication and irradiation parameters on the stress distribution that drives microstructural evolutions, such as pore growth in the IL and Al matrix rupture, were investigated. - Highlights: •Post-irradiation data for irradiated miniplates were analyzed by using their optical microscopy images. •ABAQUS finite element analysis (FEA) package was utilized to simulate the microstructural evolution of the selected plates. •Stresses were assessed to analyze their effects on microstructural changes during irradiation.

  6. Postirradiation examination of a low enriched U3Si2-Al fuel element manufactured and irradiated at Batan, Indonesia

    International Nuclear Information System (INIS)

    Suripto, A.; Sugondo, S.; Nasution, H.

    1994-01-01

    The first low-enriched U 3 Si 2 -Al dispersion plate-type fuel element produced at the Nuclear Fuel Element Center, BATAN, Indonesia, was irradiated to a peak 235 U burnup of 62%. Postirradiation examinations performed to data shows the irradiation behavior of this element to be similar to that of U 3 Si 2 -Al plate-type fuel produced and tested at other institutions. The main effect of irradiation on the fuel plates is a thickness increase of 30--40 μm (2.5-3.0%). This thickness increase is almost entirely due to the formation of a corrosion layer (Boehmite). The contribution of fuel swelling to the thickness increase is rather small (less than 10 μm) commensurate with the burnup of the fuel and the relatively moderate as-fabricated fuel volume fraction of 27% in the fuel meat

  7. Irradiation behavior of U{sub 6}Mn-Al dispersion fuel elements

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, M.K. E-mail: mitchell.meyer@anl.gov; Wiencek, T.C.; Hayes, S.L.; Hofman, G.L

    2000-04-01

    Irradiation testing of U{sub 6}Mn-Al dispersion fuel miniplates was conducted in the Oak Ridge Research Reactor (ORR). Post-irradiation examination showed that U{sub 6}Mn in an unrestrained plate configuration performs similarly to U{sub 6}Fe under irradiation, forming extensive and interlinked fission gas bubbles at a fission density of approximately 3x10{sup 27} m{sup -3}. Fuel plate failure occurs by fission gas pressure driven 'pillowing' on continued irradiation.

  8. Repository emplacement costs for Al-clad high enriched uranium spent fuel

    International Nuclear Information System (INIS)

    McDonell, W.R.; Parks, P.B.

    1994-01-01

    A range of strategies for treatment and packaging of Al-clad high-enriched uranium (HEU) spent fuels to prevent or delay the onset of criticality in a geologic repository was evaluated in terms of the number of canisters produced and associated repository costs incurred. The results indicated that strategies in which neutron poisons were added to consolidated forms of the U-Al alloy fuel generally produced the lowest number of canisters and associated repository costs. Chemical processing whereby the HEU was removed from the waste form was also a low cost option. The repository costs generally increased for isotopic dilution strategies, because of the substantial depleted uranium added. Chemical dissolution strategies without HEU removal were also penalized because of the inert constituents in the final waste glass form. Avoiding repository criticality by limiting the fissile mass content of each canister incurred the highest repository costs

  9. Irradiation tests of U3Si2-Al fuels up to very high fission densities

    International Nuclear Information System (INIS)

    Nuding, M.; Boening, K.

    2001-01-01

    The new research reactor of the Munich Technical University (TUM), the FRM-II, will have U 3 Si 2 -Al as the fuel. This fuel is considered qualified and optimally usable in the light of findings obtained in the RERTR program (Reduced Enrichment for Research and Test Reactors). The RERTR program was conducted to develop new fuel for the use of low enriched uranium (LEU) in research reactors. As the unique properties of the FRM-II in research and application are based also on achieving a very compact reactor core with highly enriched uranium (HEU), additional irradiation tests were performed on the basis of the RERTR program. They were run in close cooperation with the French Commissariat a l'Energie Atomique (CEA) in its SILOE and OSIRIS facilities, among others. After extensive evaluation, also of other studies, these tests confirm the RERTR findings about fuel swelling behavior and, consequently, the suitability of U 3 Si 2 -Al (HEU) for use in the compact core of the FRM-II. (orig.) [de

  10. Fuel effect on solution combustion synthesis of Co(Cr,Al)2O4 pigments

    International Nuclear Information System (INIS)

    Gilabert, J.; Palacios, M.D.; Sanz, V.; Mestre, S.

    2017-01-01

    The fuel effect on the synthesis of a ceramic pigment with a composition CoCr2−2ΨAl2ΨO4 (0≤Ψ≤1) by means of solution combustion synthesis process (SCS) has been studied. Three different fuels were selected to carry out the synthesis (urea, glycine and hexamethylentetramine (HMT)). Highly foamy pigments with very low density were obtained. Fd-3m spinel-type structure was obtained in all the experiments. Nevertheless, crystallinity and crystallite size of the spinels show significant differences with composition and fuel. The use of glycine along with the chromium-richest composition favours ion rearrangement to obtain the most ordered structure. Lattice parameter does not seem to be affected by fuel, although it evolves with Ψ according to Vegard's law. Colouring power in a transparent glaze shows important variations with composition. On the other hand, fuel effect presents a rather low influence since practically the same shades are obtained. However, it exerts certain effect on luminosity (L*). [es

  11. Reaction layer growth and reaction heat of U-Mo/Al dispersion fuels using centrifugally atomized powders

    International Nuclear Information System (INIS)

    Ryu, Ho Jin; Han, Young Soo; Park, Jong Man; Park, Soon Dal; Kim, Chang Kyu

    2003-01-01

    The growth behavior of reaction layers and heat generation during the reaction between U-Mo powders and the Al matrix in U-Mo/Al dispersion fuels were investigated. Annealing of 10 vol.% U-10Mo/Al dispersion fuels at temperatures from 500 to 550 deg. C was carried out for 10 min to 36 h to measure the growth rate and the activation energy for the growth of reaction layers. The concentration profiles of reaction layers between the U-10Mo vs. Al diffusion couples were measured and the integrated interdiffusion coefficients were calculated for the U and Al in the reaction layers. Heat generation of U-Mo/Al dispersion fuels with 10-50 vol.% of U-Mo fuel during the thermal cycle from room temperature to 700 deg. C was measured employing the differential scanning calorimetry. Exothermic heat from the reaction between U-Mo and the Al matrix is the largest when the volume fraction of U-Mo fuel is about 30 vol.%. The unreacted fraction in the U-Mo powders increases as the volume fraction of U-Mo fuel increases from 30 to 50 vol.%

  12. Solution combustion synthesis of strontium aluminate, SrAl2O4, powders: single-fuel versus fuel-mixture approach.

    Science.gov (United States)

    Ianoş, Robert; Istratie, Roxana; Păcurariu, Cornelia; Lazău, Radu

    2016-01-14

    The solution combustion synthesis of strontium aluminate, SrAl2O4, via the classic single-fuel approach and the modern fuel-mixture approach was investigated in relation to the synthesis conditions, powder properties and thermodynamic aspects. The single-fuel approach (urea or glycine) did not yield SrAl2O4 directly from the combustion reaction. The absence of SrAl2O4 was explained by the low amount of energy released during the combustion process, in spite of the highly negative values of the standard enthalpy of reaction and standard Gibbs free energy. In the case of single-fuel recipes, the maximum combustion temperatures measured by thermal imaging (482 °C - urea, 941 °C - glycine) were much lower than the calculated adiabatic temperatures (1864 °C - urea, 2147 °C - glycine). The fuel-mixture approach (urea and glycine) clearly represented a better option, since (α,β)-SrAl2O4 resulted directly from the combustion reaction. The maximum combustion temperature measured in the case of a urea and glycine fuel mixture was the highest one (1559 °C), which was relatively close to the calculated adiabatic temperature (1930 °C). The addition of a small amount of flux, such as H3BO3, enabled the formation of pure α-SrAl2O4 directly from the combustion reaction.

  13. Characterization of fuel miniplates fabricated with U(Mo) particles dispersed in Al-Si matrices

    International Nuclear Information System (INIS)

    Arico, S F; Mirandou, M I; Balart, S N; Fabro, J O

    2012-01-01

    In 2011 ECRI facility (Depto. ECRI, GCCN, CNEA) restarted the development for the fabrication of dispersion miniplates fuel elements in Al-Si matrix. This miniplates are fabricated with atomized U-7wt%Mo particles dispersed in a matrix formed by a mixture of pure Al and pure Si powders. The first results for an Al-4wt%Si matrix were presented at the AATN 2011 Annual Meeting. In this work, new results from the microstructural characterization of the meat in Al- 2wt%Si and pure Al miniplates are presented and compared with the previous ones. It is the intention to study the influence of the fabrication parameters as well as different Si concentration in the matrix, on the formation and characteristics of the interaction layer formed between the particles and the matrix at the end of the fabrication process. According to the results presented in this work an improvement can be observed on miniplates with Al-Si matrix respect to the one with pure Al. On the miniplates with Al- Si matrix, almost 100 % of the U(Mo) particles presented, at least in some fraction of its surface, an interaction layer composed by phases that contain Si. Moreover its morphological characteristics are independent of the crystallographic state of the U(Mo) particles. However, the oxide layer formed on the U(Mo) during the hot rolling acts as a barrier to the formation of the interaction layer. As a consequence, it is then mandatory to introduce some changes on the fabrication parameters to avoid, or at least minimize, this oxide layer (author)

  14. Development of ODS FeCrAl alloys for accident-tolerant fuel cladding

    Energy Technology Data Exchange (ETDEWEB)

    Dryepondt, Sebastien N. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Hoelzer, David T. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Pint, Bruce A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Unocic, Kinga A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-09-18

    FeCrAl alloys are prime candidates for accident-tolerant fuel cladding due to their excellent oxidation resistance up to 1400 C and good mechanical properties at intermediate temperature. Former commercial oxide dispersion strengthened (ODS) FeCrAl alloys such as PM2000 exhibit significantly better tensile strength than wrought FeCrAl alloys, which would alloy for the fabrication of a very thin (~250 m) ODS FeCrAl cladding and limit the neutronic penalty from the replacement of Zr-based alloys by Fe-based alloys. Several Fe-12-Cr-5Al ODS alloys where therefore fabricated by ball milling FeCrAl powders with Y2O3 and additional oxides such as TiO2 or ZrO2. The new Fe-12Cr-5Al ODS alloys showed excellent tensile strength up to 800 C but limited ductility. Good oxidation resistance in steam at 1200 and 1400 C was observed except for one ODS FeCrAl alloy containing Ti. Rolling trials were conducted at 300, 600 C and 800 C to simulate the fabrication of thin tube cladding and a plate thickness of ~0.6mm was reached before the formation of multiple edge cracks. Hardness measurements at different stages of the rolling process, before and after annealing for 1h at 1000 C, showed that a thinner plate thickness could likely be achieved by using a multi-step approach combining warm rolling and high temperature annealing. Finally, new Fe-10-12Cr-5.5-6Al-Z gas atomized powders have been purchased to fabricate the second generation of low-Cr ODS FeCrAl alloys. The main goals are to assess the effect of O, C, N and Zr contents on the ODS FeCrAl microstructure and mechanical properties, and to optimize the fabrication process to improve the ductility of the 2nd gen ODS FeCrAl while maintaining good mechanical strength and oxidation resistance.

  15. Corrosion of MTR type fuel plates containing U3O8-Al cermet cores

    International Nuclear Information System (INIS)

    Durazzo, M.

    1985-01-01

    The fuel plate samples containing U 3 O 8 -Al cermet cores with concentrations from 10 to 90% of U 3 O 8 weight were fabricated. Samples with 58% of U 3 O 8 eight were fabricated using compacts with densities from 75 to 95% of theoretical density. The influences of U 3 O 8 concentration and porosity of compacted core on porosity and uniformity of core thickness are discussed. The U 3 O 8 -Al cores were submitted to corrosion tests and exposed to deionized water at temperatures of 30, 50, 70 and 90 0 C by cladding deffect produced artificially. The results shown that core corrosion is accompanied by hydrogen release. The total volum of released hydrogen and the time interval to observe the initiation of hydrogen releasing (incubation time) are depending on core pososity and absolute temperature. A mechanism for U 3 O 8 -Al core corrosion process is proposed and discussed. The cladding of fuel plate samples was submitted to corrosion tests under similar conditons of the IAE-R1 reactor operating at 2, 5 and 10 MW. (Author) [pt

  16. XRD and neutron diffraction analyses of heat treated U-Mo/Al dispersion fuel

    Energy Technology Data Exchange (ETDEWEB)

    Nam, Ji Min; Kim, Woo Jeong; Ryu, Ho Jin; Lee, Kyu Hong; Park, Jong Man [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2012-10-15

    High density U Mo alloys are regarded as promising candidates for advanced research reactor fuel because they have shown stable irradiation performance when compared to other uranium alloys and compounds. However, interaction layer formation between the U Mo alloys and Al matrix degrades the irradiation performance of U Mo dispersion fuel. Therefore, addition of Ti in U Mo alloys, addition of Si in Al matrix and silicide or nitride coating on the surface of U Mo particles have been proposed in order to inhibit the interaction layer growth. In order to analyze the mechanisms of interaction layer growth inhibition by adding Ti in U Mo alloys or Si in Al matrix, accurate phase characterization of the interaction layers is required. While previous studies using X ray diffraction have been reported, laboratory X ray diffraction method has limitations such as low resolution and small measurement volume. Neutron diffraction method can be a more accurate analysis when compared with X ray diffraction method due to the large penetration depth of neutron. In this study, X ray diffraction and neutron diffraction experiments have been performed by using the laboratory X ray diffractometer and high resolution powder diffractometer (HRPD) of the HANARO research reactor in KAERI.

  17. Application of the FFTBM method and the power relative contribution to the discharge transitory of the recirculation pumps of a BWR; Aplicacion del metodo FFTBM y de la contribucion relativa de potencia al transitorio de disparo de las bombas de recirculacion de un BWR

    Energy Technology Data Exchange (ETDEWEB)

    Castillo D, R.; Ortiz V, J.; Fuentes M, L., E-mail: rogelio.castillo@inin.gob.mx [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2013-10-15

    In this work was realized the simulation of the discharge transitory of both recirculation pumps of a BWR with the Simulate-3K code. This type of transitory is used in the stability analyses for the licensing of the fuel reload. An analysis of the precision of the simulation is also presented, using the FFTBM method jointly with the power relative contribution. This way, instead of determining the total precision of the calculation, a weighed precision is obtained by the contribution of each relevant parameter of the transitory. The results show that the precision of the simulation is acceptable due to the small magnitude of the merit figure of the width total average. The error in the merit figure comes mainly from the parameters total flow in the core and temperature of the fuel in the core. (Author)

  18. Post-irradiation examination of prototype Al-64 wt% U3Si2 fuel rods from NRU

    International Nuclear Information System (INIS)

    Sears, D.F.; Primeau, M.F.; Buchanan, C.; Rose, D.

    1997-01-01

    Three prototype fuel rods containing Al-64 wt% U 3 Si 2 (3.15 gU/cm 3 ) have been irradiated to their design burnup in the NRU reactor without incident. The fuel was fabricated using production-scale equipment and processes previously developed for Al-U 3 Si fuel fabrication at Chalk River Laboratories, and special equipment developed for U 3 Si 2 powder production and handling. The rods were irradiated in NRU up to 87 at% U-235 burnup under typical driver fuel conditions; i.e., nominal coolant inlet temperature 37 degrees C, inlet pressure 654 kPa, mass flow 12.4 L/s, and element linear power ratings up to 73 kW/m. Post-irradiation examinations showed that the fuel elements survived the irradiation without defects. Fuel core diametral increases and volumetric swelling were significantly lower than that of Al-61 wt% U 3 Si fuel irradiated under similar conditions. This irradiation demonstrated that the fabrication techniques are adequate for full-scale fuel manufacture, and qualified the fuel for use in AECL's research reactors

  19. Improved performance of U-Mo dispersion fuel by Si addition in Al matrix.

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Y S; Hofman, G L [Nuclear Engineering Division

    2011-06-01

    The purpose of this report is to collect in one publication and fit together work fragments presented in many conferences in the multi-year time span starting 2002 to the present dealing with the problem of large pore formation in U-Mo/Al dispersion fuel plates first observed in 2002. Hence, this report summarizes the excerpts from papers and reports on how we interpreted the relevant results from out-of-pile and in-pile tests and how this problem was dealt with. This report also provides a refined view to explain in detail and in a quantitative manner the underlying mechanism of the role of silicon in improving the irradiation performance of U-Mo/Al.

  20. Thermal conductivity of U–Mo/Al dispersion fuel. Effects of particle shape and size, stereography, and heat generation

    International Nuclear Information System (INIS)

    Cho, Tae Won; Sohn, Dong-Seong; Kim, Yeon Soo

    2015-01-01

    This paper describes the effects of particle sphericity, interfacial thermal resistance, stereography, and heat generation on the thermal conductivity of U–Mo/Al dispersion fuel. The ABAQUS finite element method (FEM) tool was used to calculate the effective thermal conductivity of U–Mo/Al dispersion fuel by implementing fuel particles. For U–Mo/Al, the particle sphericity effect was insignificant. However, if the effect of the interfacial thermal resistance between the fuel particles and Al matrix was considered, the thermal conductivity of U–Mo/Al was increased as the particle size increases. To examine the effect of stereography, we compared the two-dimensional modeling and three-dimensional modeling. The results showed that the two-dimensional modeling predicted lower than the three-dimensional modeling. We also examined the effect of the presence of heat sources in the fuel particles and found a decrease in thermal conductivity of U–Mo/Al from that of the typical homogeneous heat generation modeling. (author)

  1. Recovery of UMo alloy from UMo/Al dispersion fuel plates by dissolution

    International Nuclear Information System (INIS)

    Ren Meng; Li Jia; Liu Jinhong; Zhu Changgui

    2011-01-01

    Methods for dissolving UMo/Al dispersion fuel plates in the compounded mixed basic aqueous (NaOH and NaNO 3 ) are studied on laboratory scale. After removing the clad and the matrix of the substandard UMo/Al dispersion fuel elements, the U loss ratios are calculated and the granularity distributions of the recovered UMo alloy powder are analyzed by the metallurgical microscope. Besides, the phase structure and the composition of the recovered UMo alloy powder are analyzed by the XRD. The results indicate that as the concentration of NaOH increases, uranium loss ratio increases; but as the concentration of NaNO 3 increases, U loss ration increases firstly and then decreases subsequently; generally, the U recovery ratios are more than 99.3%. The granularity of recovered UMo powders are very small and most parts of γ-U have been oxidated to UO 2 . Therefore, further study is required to determined whether the recovered UMo alloy could be returned to the product line. (authors)

  2. Mikrostruktur dan Karakterisasi Sifat Mekanik Lapisan Cr3C2-NiAl-Al2O3 Hasil Deposisi Dengan Menggunakan High Velocity Oxygen Fuel Thermal Spray Coating

    Directory of Open Access Journals (Sweden)

    Edy Riyanto

    2012-03-01

    Full Text Available Surface coating processing of industrial component with thermal spray coatings have been applied in many industrial fields. Ceramic matrix composite coating which consists of Cr3C2-Al2O3-NiAl had been carried out to obtain layers of material that has superior mechanical properties to enhance component performance. Deposition of CMC with High Velocity Oxygen Fuel (HVOF thermal spray coating has been employed. This study aims to determine the effect of powder particle size on the microstructure, surface roughness and hardness of the layer, by varying the NiAl powder particle size. Test results show NiAl powder particle size has an influence on the mechanical properties of CMC coating. Hardness of coating increases and surface roughness values of coating decrease with smaller NiAl particle size.  

  3. Thermophysical properties of heat-treated U-7Mo/Al dispersion fuel

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Tae Won; Kim, Yeon Soo; Park, Jong Man; Lee, Kyu Hong; Kim, Sunghwan; Lee, Chong Tak; Yang, Jae Ho; Oh, Jang Soo; Sohn, Dong-Seong

    2018-04-01

    In this study, the effects of interaction layer (IL) on thermophysical properties of U-7Mo/Al dispersion fuel were examined. Microstructural analyses revealed that ILs were formed uniformly on U-Mo particles during heating of U-7Mo/Al samples. The IL volume fraction was measured by applying image analysis methods. The uranium loadings of the samples were calculated based on the measured meat densities at 298 K. The density of the IL was estimated by using the measured density and IL volume fraction. Thermal diffusivity and heat capacity of the samples after the heat treatment were measured as a function of temperature and volume fractions of U-Mo and IL. The thermal conductivity of IL-formed U-7Mo/Al was derived by using the measured thermal diffusivity, heat capacity, and density. The thermal conductivity obtained in the present study was lower than that predicted by the modified Hashin–Shtrikman model due to the theoretical model’s inability to consider the thermal resistance at interfaces between the meat constituents.

  4. Thermophysical properties of heat-treated U-7Mo/Al dispersion fuel

    Science.gov (United States)

    Cho, Tae Won; Kim, Yeon Soo; Park, Jong Man; Lee, Kyu Hong; Kim, Sunghwan; Lee, Chong Tak; Yang, Jae Ho; Oh, Jang Soo; Sohn, Dong-Seong

    2018-04-01

    In this study, the effects of interaction layer (IL) on thermophysical properties of U-7Mo/Al dispersion fuel were examined. Microstructural analyses revealed that ILs were formed uniformly on U-Mo particles during heating of U-7Mo/Al samples. The IL volume fraction was measured by applying image analysis methods. The uranium loadings of the samples were calculated based on the measured meat densities at 298 K. The density of the IL was estimated by using the measured density and IL volume fraction. Thermal diffusivity and heat capacity of the samples after the heat treatment were measured as a function of temperature and volume fractions of U-Mo and IL. The thermal conductivity of IL-formed U-7Mo/Al was derived by using the measured thermal diffusivity, heat capacity, and density. The thermal conductivity obtained in the present study was lower than that predicted by the modified Hashin-Shtrikman model due to the theoretical model's inability to consider the thermal resistance at interfaces between the meat constituents.

  5. Natural gas as fuel - chances and risks; Erdgas als Kraftstoff-Chancen und Risiken.

    Energy Technology Data Exchange (ETDEWEB)

    Wackertapp, H.; Wember, G. [Ruhrgas AG, Essen (Germany)

    2001-11-01

    By reducing the tax payable on natural gas as part of the ecological tax reform, the German government has created the economic framework for the break-through of the automotive fuel, natural gas. Consequently, natural gas has since become much more popular for driving motor engines. The gas industry sees its main task as the development of a natural gas filling station network. There are currently about 200 filling stations with natural gas fuelling facilities in Germany. (orig.) [German] Die Bundesregierung hat mit der in der oekologischen Steuerreform verankerten Mineraloelsteuerbeguenstigung fuer Erdgas die wirtschaftlichen Voraussetzungen fuer einen Durchbruch des neuen Kraftstoffs ''Erdgas'' geschaffen. Demzufolge hat der mobile Einsatz von Erdgas deutlich an Bedeutung gewonnen. Die Gaswirtschaft sieht den Aufbau der Betankungsinfrastruktur als ihre Hauptaufgabe an. Aktuell kann an etwa 200 Tankstellen Erdgas getankt werden. (orig.)

  6. Irradiation behavior of the interaction product of U-Mo fuel particle dispersion in an Al matrix

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yeon Soo, E-mail: yskim@anl.gov [Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 (United States); Hofman, G.L. [Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 (United States)

    2012-06-15

    Highlights: Black-Right-Pointing-Pointer We in-pile tested U-Mo dispersion in Al matrix. Black-Right-Pointing-Pointer We observed interaction layer growth between U-Mo and Al and pore formation there. Black-Right-Pointing-Pointer Pores degrades thermal conductivity and structural integrity of the fueled zone. Black-Right-Pointing-Pointer The amorphous behavior of interaction layers is thought to be the main reason for unstable large pore growth. Black-Right-Pointing-Pointer A mechanism for pore formation and possible remedy to prevent it are proposed. - Abstract: Irradiation performance of U-Mo fuel particles dispersed in Al matrix is stable in terms of fuel swelling and is suitable for the conversion of research and test reactors from highly enriched uranium (HEU) to low enriched uranium (LEU). However, tests of the fuel at high temperatures and high burnups revealed obstacles caused by the interaction layers forming between the fuel particle and matrix. In some cases, fission gas filled pores grow and interconnect in the interdiffusion layer resulting in fuel plate failure. Postirradiation observations are made to examine the behavior of the interdiffusion layers. The interdiffusion layers show a fluid-like behavior characteristic of amorphous materials. In the amorphous interdiffusion layers, fission gas diffusivity is high and the material viscosity is low so that the fission gas pores readily form and grow. Based on the observations, a pore formation mechanism is proposed and potential remedies to suppress the pore growth are also introduced.

  7. New contributions to the study of Corixoidea: cytogenetic characterization of three species of Sigara from Argentina and the plausible mechanisms of karyotype evolution within Nepomorpha Nuevas contribuciones al estudio de Corixoidea: caracterización citogenética de tres especies de Sigara de Argentina y los posibles mecanismos de evolución del cariotipo en Nepomorpha

    Directory of Open Access Journals (Sweden)

    María José Bressa

    2007-12-01

    Full Text Available Cytogenetic studies in Heteroptera contribute to the analysis of evolutionary trends within the group. Heteroptera are characterized by the possession of holokinetic chromosomes, different sex chromosome mechanisms and a pair of m chromosomes in some species. In the present work, the male karyotype and meiosis in Sigara denseconscripta (Breddin, S. chrostowskii Jaczewski, and S. rubyae (Hungerford are described. The three species share a diploid chromosome number of 2n= 24 with a pair of m chromosomes and an XY/XX sex chromosome system. With this study the chromosome number of 30 species of Corixoidea are known and the modal karyotype is 2n= 20+2m+XY in males. The available cytogenetic information in Heteroptera led us to suggest that the presence of a pair of m chromosomes and an XY/XX sex chromosome system could be considered as plesiomorphic for Nepomorpha. The absence of m chromosomes in species of Ochteroidea and Nepoidea, and the sex chromosome systems X0 and Xn0 (male in species of Corixoidea, Naucoroidea, and Nepoidea should be considered as derived characters, which arose later in evolution.Los estudios citogenéticos en Heteroptera contribuyen al análisis de las tendencias evolutivas en el taxón. Los Heteroptera se caracterizan por poseer cromosomas holocinéticos, diferentes sistemas de cromosomas sexuales y un par de cromosomas m en algunas especies. En este trabajo describimos el cariotipo y la meiosis masculina de Sigara denseconscripta (Breddin, S. chrostowskii Jaczewski y S. rubyae (Hungerford. Las tres especies tienen un número diploide de 24, con un par de cromosomas m y un sistema de cromosomas sexuales XY/XX. Con estos resultados son 30 las especies de Corixoidea estudiadas citogenéticamente y el cariotipo modal de la superfamilia es 2n= 20+2m+XY en machos. La información citogenética disponible hasta el presente en Heteroptera nos permite sugerir que la presencia de cromosomas m y cromosomas sexuales XY/XX, ser

  8. Swelling of U-7Mo/Al-Si dispersion fuel plates under irradiation – Non-destructive analysis of the AFIP-1 fuel plates

    Energy Technology Data Exchange (ETDEWEB)

    Wachs, D.M., E-mail: daniel.wachs@inl.gov [Idaho National Laboratory, Nuclear Fuels and Materials Division, P.O. Box 1625, Idaho Falls, ID 83415-6188 (United States); Robinson, A.B.; Rice, F.J. [Idaho National Laboratory, Characterization and Advanced PIE Division, P.O. Box 1625, Idaho Falls, ID 83415-6188 (United States); Kraft, N.C.; Taylor, S.C. [Idaho National Laboratory, Nuclear Fuels and Materials Division, P.O. Box 1625, Idaho Falls, ID 83415-6188 (United States); Lillo, M. [Idaho National Laboratory, Nuclear Systems Design and Analysis Division, P.O. Box 1625, Idaho Falls, ID 83415-6188 (United States); Woolstenhulme, N.; Roth, G.A. [Idaho National Laboratory, Nuclear Fuels and Materials Division, P.O. Box 1625, Idaho Falls, ID 83415-6188 (United States)

    2016-08-01

    Extensive fuel-matrix interactions leading to plate pillowing have proven to be a significant impediment to the development of a suitable high density low-enriched uranium molybdenum alloy (U-Mo) based dispersion fuel for high power applications in research reactors. The addition of silicon to the aluminum matrix was previously demonstrated to reduce interaction layer growth in mini-plate experiments. The AFIP-1 project involved the irradiation, in-canal examination, and post-irradiation examination of two fuel plates. The irradiation of two distinct full size, flat fuel plates (one using an Al-2wt%Si matrix and the other an Al-4043 (∼4.8 wt% Si) matrix) was performed in the INL ATR reactor in 2008–2009. The irradiation conditions were: ∼250 W/cm{sup 2} peak Beginning Of Life (BOL) power, with a ∼3.5e21 f/cm{sup 3} peak burnup. The plates were successfully irradiated and did not show any pillowing at the end of the irradiation. This paper reports the results and interpretation of the in-canal and post-irradiation non-destructive examinations that were performed on these fuel plates. It further compares additional PIE results obtained on fuel plates irradiated in contemporary campaigns in order to allow a complete comparison with all results obtained under similar conditions. Except for a brief indication of accelerated swelling early in the irradiation of the Al-2Si plate, the fuel swelling is shown to evolve linearly with the fission density through the maximum burnup.

  9. Multilayer (TiN, TiAlN) ceramic coatings for nuclear fuel cladding

    Energy Technology Data Exchange (ETDEWEB)

    Alat, Ece, E-mail: exa179@psu.edu [Department of Materials Science and Engineering, The Pennsylvania State University, University Park, PA 16802 (United States); Motta, Arthur T. [Department of Materials Science and Engineering, The Pennsylvania State University, University Park, PA 16802 (United States); Department of Mechanical and Nuclear Engineering, The Pennsylvania State University, University Park, PA 16802 (United States); Comstock, Robert J.; Partezana, Jonna M. [Westinghouse Electric Co., Beulah Rd, Pittsburgh, PA 1332 (United States); Wolfe, Douglas E. [Department of Materials Science and Engineering, The Pennsylvania State University, University Park, PA 16802 (United States); Applied Research Laboratory, The Pennsylvania State University, 119 Materials Research Building, University Park, PA 16802 (United States)

    2016-09-15

    In an attempt to develop an accident-tolerant fuel (ATF) that can delay the deleterious consequences of loss-of-coolant-accidents (LOCA), multilayer coatings were deposited onto ZIRLO{sup ®} coupon substrates by cathodic arc physical vapor deposition (CA-PVD). Coatings were composed of alternating TiN (top) and Ti{sub 1-x}Al{sub x}N (2-layer, 4-layer, 8-layer and 16-layer) layers. The minimum TiN top coating thickness and coating architecture were optimized for good corrosion and oxidation resistance. Corrosion tests were performed in static pure water at 360 °C and 18.7 MPa for up to 90 days. The optimized coatings showed no spallation/delamination and had a maximum of 6 mg/dm{sup 2} weight gain, which is 6 times smaller than that of a control sample of uncoated ZIRLO{sup ®} which showed a weight gain of 40.2 mg/dm{sup 2}. The optimized architecture features a ∼1 μm TiN top layer to prevent boehmite phase formation during corrosion and a TiN/TiAlN 8-layer architecture which provides the best corrosion performance. - Highlights: • The first study on multilayer TiAlN and TiN ceramic coatings on ZIRLO{sup ®} coupons. • Corrosion tests were performed at 360°C and 18.7 MPa for up to 90 days. • Coatings adhered well to the substrate, and showed no spallation/delamination. • Weight gains were six times lower than those of uncoated ZIRLO{sup ®} samples. • Longer and higher temperature corrosion tests will be discussed in a further paper.

  10. In-pile test results of U-silicide or U-nitride coated U-7Mo particle dispersion fuel in Al

    Science.gov (United States)

    Kim, Yeon Soo; Park, J. M.; Lee, K. H.; Yoo, B. O.; Ryu, H. J.; Ye, B.

    2014-11-01

    U-silicide or U-nitride coated U-Mo particle dispersion fuel in Al (U-Mo/Al) was in-pile tested to examine the effectiveness of the coating as a diffusion barrier between the U-7Mo fuel kernels and Al matrix. This paper reports the PIE data and analyses focusing on the effectiveness of the coating in terms of interaction layer (IL) growth and general fuel performance. The U-silicide coating showed considerable success, but it also provided evidence for additional improvement for coating process. The U-nitride coated specimen showed largely inefficient results in reducing IL growth. From the test, important observations were also made that can be utilized to improve U-Mo/Al fuel performance. The heating process for coating turned out to be beneficial to suppress fuel swelling. The use of larger fuel particles confirmed favorable effects on fuel performance.

  11. In-pile test results of U-silicide or U-nitride coated U-7Mo particle dispersion fuel in Al

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yeon Soo, E-mail: yskim@anl.gov [Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 (United States); Park, J.M.; Lee, K.H.; Yoo, B.O. [Korea Atomic Energy Research Institute, 989-111 Daedeokdaero, Yuseong-gu, Daejeon 305-353 (Korea, Republic of); Ryu, H.J. [Dept. of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Ye, B. [Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 (United States)

    2014-11-15

    U-silicide or U-nitride coated U-Mo particle dispersion fuel in Al (U-Mo/Al) was in-pile tested to examine the effectiveness of the coating as a diffusion barrier between the U-7Mo fuel kernels and Al matrix. This paper reports the PIE data and analyses focusing on the effectiveness of the coating in terms of interaction layer (IL) growth and general fuel performance. The U-silicide coating showed considerable success, but it also provided evidence for additional improvement for coating process. The U-nitride coated specimen showed largely inefficient results in reducing IL growth. From the test, important observations were also made that can be utilized to improve U-Mo/Al fuel performance. The heating process for coating turned out to be beneficial to suppress fuel swelling. The use of larger fuel particles confirmed favorable effects on fuel performance.

  12. Overview of lower length scale model development for accident tolerant fuels regarding U3Si2 fuel and FeCrAl cladding

    International Nuclear Information System (INIS)

    Zhang, Yongfeng

    2016-01-01

    U3Si2 and FeCrAl have been proposed as fuel and cladding concepts, respectively, for accident tolerance fuels with higher tolerance to accident scenarios compared to UO2. However, a lot of key physics and material properties regarding their in-pile performance are yet to be explored. To accelerate the understanding and reduce the cost of experimental studies, multiscale modeling and simulation are used to develop physics-based materials models to assist engineering scale fuel performance modeling. In this report, the lower-length-scale efforts in method and material model development supported by the Accident Tolerance Fuel (ATF) high-impact-problem (HIP) under the NEAMS program are summarized. Significant progresses have been made regarding interatomic potential, phase field models for phase decomposition and gas bubble formation, and thermal conductivity for U3Si2 fuel, and precipitation in FeCrAl cladding. The accomplishments are very useful by providing atomistic and mesoscale tools, improving the current understanding, and delivering engineering scale models for these two ATF concepts.

  13. Overview of lower length scale model development for accident tolerant fuels regarding U3Si2 fuel and FeCrAl cladding

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yongfeng [Idaho National Laboratory

    2016-09-01

    U3Si2 and FeCrAl have been proposed as fuel and cladding concepts, respectively, for accident tolerance fuels with higher tolerance to accident scenarios compared to UO2. However, a lot of key physics and material properties regarding their in-pile performance are yet to be explored. To accelerate the understanding and reduce the cost of experimental studies, multiscale modeling and simulation are used to develop physics-based materials models to assist engineering scale fuel performance modeling. In this report, the lower-length-scale efforts in method and material model development supported by the Accident Tolerance Fuel (ATF) high-impact-problem (HIP) under the NEAMS program are summarized. Significant progresses have been made regarding interatomic potential, phase field models for phase decomposition and gas bubble formation, and thermal conductivity for U3Si2 fuel, and precipitation in FeCrAl cladding. The accomplishments are very useful by providing atomistic and mesoscale tools, improving the current understanding, and delivering engineering scale models for these two ATF concepts.

  14. Effect of the Zr elements with thermal properties changes of U-7Mo-xZr/Al dispersion fuel

    International Nuclear Information System (INIS)

    Supardjo; Agoeng Kadarjono; Boybul; Aslina Br Ginting

    2016-01-01

    Thermal properties data of nuclear fuel is required as input data to predict material properties change phenomenon during the fabrication process and irradiated in a nuclear reactor. Study the influence of Zr element in the U-7Mo-xZr/Al (x = 1%, 2% and 3%) fuel dispersion to changes in the thermal properties at various temperatures have been stiffened. Thermal analysis includes determining the melting temperature, enthalpy, and phase changes made using Differential Thermal Analysis (DTA) in the temperature range between 30 °C up to 1400 °C, while the heat capacity of U-7Mo-xZr alloy and U-7Mo-xZr/Al dispersion fuel using Differential Scanning Calorimeter (DSC) at room temperature up to 450 °C. Thermal analyst data DTA shows that Zr levels of all three compositions showed a similar phenomenon. At temperatures between 565.60 °C - 584.98 °C change becomes α + δ to α + γ phase and at 649.22 °C – 650.13 °C happen smelting Al matrix Occur followed by a reaction between Al matrix with U-7Mo-xZr on 670.38 °C - 673.38 °C form U (Al, Mo)x Zr. Furthermore a phase change α + β becomes β + γ Occurs at temperatures 762.08 °C - 776.33 °C and diffusion between the matrix by U-7Mo-xZr/Al on 853.55 °C - 875.20 °C. Every phenomenon that Occurs, enthalpy posed a relative stable. Consolidation of uranium Occur in 1052.42 °C - 1104.99 °C and decomposition reaction of U (Al, Mo)x and U (Al, Zr)_x becomes (UAl_4, UAl_3, UAl_2), U-Mo, and UZr on 1328,34 °C - 1332,06 °C , The existence of Zr in U-Mo alloy increases the heat capacity of the U-7Mo-xZr/Al, dispersion fuel and the higher heat capacity of Zr levels increased due to interactions between the atoms of Zr with Al matrix so that the heat absorbed by the fuel increase. (author)

  15. The technique for determination of surface contamination by uranium on U3Si2-Al plate-type fuel elements

    International Nuclear Information System (INIS)

    Li Shulan; He Fengqi; Wang Qingheng; Han Jingquan

    1993-04-01

    The NDT method for determining the surface contamination by uranium on U 3 Si 2 -Al plate-type fuel elements, the process of standard specimen preparation and the graduation curve are described. The measurement results of U 3 Si 2 -Al plate-type fuel elements show that the alpha counting method to measure the surface contamination by uranium on fuel plate is more reliable. The UB-1 type surface contamination meter, which was recently developed, has many advantages such as high sensitivity to determine the uranium pollution, short time in measuring, convenience for operation, and the minimum detectable amount of uranium is 5 x 10 -10 g/cm 2 . The measuring device is controlled by a microcomputer. Besides data acquisition and processing, it has functions of statistics, output data on terminal or to printer and alarm. The procedures of measurement are fully automatic. All of these will meet the measuring needs in batch process

  16. Annealing tests of in-pile irradiated oxide coated U-Mo/Al-Si dispersed nuclear fuel

    Science.gov (United States)

    Zweifel, T.; Valot, Ch.; Pontillon, Y.; Lamontagne, J.; Vermersch, A.; Barrallier, L.; Blay, T.; Petry, W.; Palancher, H.

    2014-09-01

    U-Mo/Al based nuclear fuels have been worldwide considered as a promising high density fuel for the conversion of high flux research reactors from highly enriched uranium to lower enrichment. In this paper, we present the annealing test up to 1800 °C of in-pile irradiated U-Mo/Al-Si fuel plate samples. More than 70% of the fission gases (FGs) are released during two major FG release peaks around 500 °C and 670 °C. Additional characterisations of the samples by XRD, EPMA and SEM suggest that up to 500 °C FGs are released from IDL/matrix interfaces. The second peak at 670 °C representing the main release of FGs originates from the interaction between U-Mo and matrix in the vicinity of the cladding.

  17. Irradiation performance of U-Mo-Ti and U-Mo-Zr dispersion fuels in Al-Si matrixes

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yeon Soo, E-mail: yskim@anl.gov [Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 (United States); Hofman, G.L. [Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 (United States); Robinson, A.B.; Wachs, D.M. [Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415-6188 (United States); Ryu, H.J.; Park, J.M.; Yang, J.H. [Korea Atomic Energy Research Institute, 150 Deokjin-dong, Yuseong-gu, Daejeon 305-353 (Korea, Republic of)

    2012-08-15

    Performance of U-7 wt.%Mo with 1 wt.%Ti, 1 wt.%Zr or 2 wt.%Zr, dispersed in an Al-5 wt.%Si alloy matrix, was investigated through irradiation tests in the ATR at INL and HANARO at KAERI. Post-irradiation metallographic features show that the addition of Ti or Zr suppresses interaction layer growth between the U-Mo and the Al-5 wt.%Si matrix. However, higher fission gas swelling was observed in the fuel with Zr addition, while no discernable effect was found in the fuel with Ti addition as compared to U-Mo without the addition. Known to have a destabilizing effect on the {gamma}-phase U-Mo, Zr, either as alloy addition or fission product, is ascribed for the disadvantageous result. Considering its benign effect on fuel swelling, with slight disadvantage from neutron economy point of view, Ti may be a better choice for this purpose.

  18. Contribuciones al conocimiento del género Phragmotheca cuatr. 1 (Bombacaceae-Quararibeae).

    OpenAIRE

    Fernández Alonso, José Luis

    1996-01-01

    Se comenta la posicidn sistemática de Phragmotheca en relacidn con la tribu Quararibeae y se incluye una clave para la separación de los géneros de bombacáceas de hoja entera o unifoliolada del norte de Suramdrica. Se revisa la utilidad'de algunos caracteres en la separación de las especies y se presenta una clave diagnbstica. Se describen e ilustran 4 nuevas especies y dos taxones infraespeclficos P. rubriflora, P. lemniscata, P. hydra, P. siderosa subsp. megacarpa, F! amazonl...

  19. Contribuciones al conocimiento de la flora del País Vasco, II

    Directory of Open Access Journals (Sweden)

    AIZPURU, I., APERRIBAY, J.A., ASEGINOLAZA, C., GARIN, F., VIVANT, J.

    1997-01-01

    Cuscuta scandens Brot. subsp. cesatiana (BERTOL. Soó, Fallopia sachalinensis (FRIEDERICH SCHMIDT PETROP. Ronse Decraene, Galium debile Desv., Geum hispidum Fries y Myosurus minimus L.; se combina, además, Apium graveolens L. subsp. butronensis (D. GOMEZ and G. MONTSERRAT I. AIZPURU, stat. nov.

  20. Contribuciones al estudio de la Parasitología en Colombia

    Directory of Open Access Journals (Sweden)

    Uribe-Piedrahita César

    1947-12-01

    Full Text Available 1- Myxobolidae parasito de la vesícula biliar de una Rana de los Llanos Orientales (Resumen: Se observó un Myxobolidae, Myxobolus pfeitteri, parásito de la vesícula biliar de Rana palmipes, habitante de los Llanos orientales de Colombia. Se destaca su papel patógeno.  Creemos que es el primer Myxobolidae descrito en Colombia. / 2- Observaciones sobre un Trichomonas sp. (Resumen: Aechmea bromeliaefolia / Greigia Danielii / Guzmania costaricensis / Guzmania diffusa / Guzmania glomerata / Guzmania minor Mez var / Flammea / Pitcairnia Bakeri / Pitcairnia Barrigae / Pitcairnia costata / Pitcairnia diffusa / Pitcairnia excerta / Pitcairnia lepidopetalon / Pitcairnia squarrosa / Pitcairnia squarrosa var. Colorata / Tillandsia hospitalis / Tillandsia pulchella / Vriesia Hodgei.

  1. Notes i contribucions al coneixement de la flora de Menorca (X). Notes florístiques

    OpenAIRE

    Fraga-Arguimbau, Pere

    2014-01-01

    Es donen a conèixer noves dades corològiques i observacions taxonòmiques per a la flora de Menorca referents a 50 tàxons. D'aquests 13 són novetat per a la flora de les Balears: Agrostis stolonifera subsp. gaditana (Boiss. & Reut.) Valdés & H. Scholz, Asteriscus pygmaeus (DC.) Coss. & Durieu, Callitriche obtnsangula Le Gall, Dactylis glomerata subsp. hackelii (Asch. & Graebn.) Cif. & Giacom., Daucus muricatus (L.) L., Ehrharta calycina J.E. Sm., Eleocharis palustris subsp. waltersii Bures & D...

  2. Contribuciones al conocimiento del género Phragmotheca Cuatr. (Bombacaceae-Quararibeae

    Directory of Open Access Journals (Sweden)

    Fernández Alonso José Luis

    1996-11-01

    Full Text Available The systematic position of Phragmotheca in the tribe quararibeae is discussed and a key for the Bombacaceae with simple or unifoliolate leaves occurring in northern South America is included. The diagnostic utility of some characters in the segregation of species in Phragmotheca, is reviewed and a diagnostic key is presented. Four new species and two new infraspecific taxa are described and illustrated: P.rubriflora, P.lemniscata, P.hydra, P.siderosa subsp. megacarpa and P. amazonica varo leticiana from Colombia and P.sidereotricha from Perú.Se comenta la posición sistemática de Phragmotheca en relación con la tribu Quararibeae y se incluye una clave para la separación de los géneros de bombacáceas de hoja entera o unifoliolada del norte de Suramérica. Se revisa la utilidad de algunos caracteres en la separación de las especies y se presenta una clave diagnóstica. Se describen e ilustran 4 nuevas especies y dos taxones infraespecíficos P. rubriflora, P. lemniscata, P. hydra, P. siderosa subsp. megacarpa, P. amazonica varo leticiana de Colombia y P. sidereotricha de Perú.

  3. High-uranium-loaded U3O8-Al fuel element development program [contributed by N.M. Martin, ORNL

    International Nuclear Information System (INIS)

    Martin, M.M.

    1993-01-01

    The High-Uranium-Loaded U 3 O 8 -Al Fuel Element Development Program supports Argonne National Laboratory efforts to develop high-uranium-density research and test reactor fuel to accommodate use of low-uranium enrichment. The goal is to fuel most research and test reactors with uranium of less than 20% enrichment for the purpose of lowering the potential for diversion of highly-enriched material for nonpeaceful usages. The specific objective of the program is to develop the technological and engineering data base for U 3 O 8 -Al plate-type fuel elements of maximal uranium content to the point of vendor qualification for full scale fabrication on a production basis. A program and management plan that details the organization, supporting objectives, schedule, and budget is in place and preparation for fuel and irradiation studies is under way. The current programming envisions a program of about four years duration for an estimated cost of about two million dollars. During the decades of the fifties and sixties, developments at Oak Ridge National Laboratory led to the use of U 3 O 8 -Al plate-type fuel elements in the High Flux Isotope Reactor, Oak Ridge Research Reactor, Puerto Rico Nuclear Center Reactor, and the High Flux Beam Reactor. Most of the developmental information however applies only up to a uranium concentration of about 55 wt % (about 35 vol % U 3 O 8 ). The technical issues that must be addressed to further increase the uranium loading beyond 55 wt % involve plate fabrication phenomena of voids and dogboning, fuel behavior under long irradiation, and potential for the thermite reaction between U 3 O 8 and aluminum. (author)

  4. Thermal Characteristic Of AIMg2 Cladding And Fuel Plates Of U3Si2-Al With Various Uranium Loading

    International Nuclear Information System (INIS)

    Aslina, Br. G.; Suparjo; Aggraini, D.; Hasbullah, N.

    1998-01-01

    Thermal characteristic analyzed in this paper included linear expansion value, coefficient expansion, and enthalpy of cladding material fuel core and fuel plate of U 3 Si 2 -AI. Before analyzing, the fresh cladding of AIMg2 (without treatment) and the rolled AIMg2 were annealed at temperature of 425 o C for 1 hour, and the fuel plates of U 3 Si 2 -AI was prepared for various uranium loading of 0.9 - 3.6 - 4.2 - 4.8 and 5.2 g/cm 3 . Linear expansion nominal value and expansion coefficient were analyzed by using Dilatometer whereas enthalpy determination used Differential Thermal Analysis (DTA). The linear expansion and expansion coefficient analysis was performed to study the dimension cladding and of fuel plates during their stay in the reactor core, whereas determination of enthalpy was carried out to estimate the energy absorbed and released by fuel meat of U 3 Si 2 -AI to the cooling water through AlMg2 as a cladding. The result showed that the linear expansion and expansion coefficient of fresh AIMg2 cladding, rolled AIMg2 and fuel plates of U 3 Si 2 -AI are increased with the increase of temperature as well as the increase of uranium loading. The enthalpy measure showed that the enthalpy of fresh AIMg2 is smaller than that of rolled AIMg2 but melting temperature of fresh AIMg2 is greater than that of rolled AIMg2. The enthalpy of fuel plates and meat of U 3 Si 2 -AI is less than that of plates of U 3 Si 2 -AI. The enthalpy of fuel platers and meat of U 3 Si 2 -AI decrease with the increase of uranium loading. It is concluded that the fuel meat more reactive than fuel plates of U 3 Si 2 -AI

  5. Study of the residual porosity in fuel plate cores based on U3O8 - Al dispersions

    International Nuclear Information System (INIS)

    Durazzo, M.

    2005-01-01

    The residual porosity in the meat of nuclear dispersion fuel plates, the fabrication voids, explains the corrosion behaviour of the meats when exposed to the water used as coolant and moderator of MTR type research reactors. The fabrication voids also explain variations in irradiation performance of many fuel dispersion for nuclear reactors. To obtain improved corrosion and irradiation performance, we must understand the fabrication factors that control the amount of void volume in fuel plate meats. The purpose of this study was to investigate the void content of aluminum-base dispersion-type U 3 O 8 -Al fuel plates depending on the characteristics of the starting fuel dispersion used to produce the fuel meat, which is fabricated by pressing. The void content depends on the U 3 O 8 concentration. For a particular U 3 O 8 content, the rolling process establishes a constant void concentration, which is called equilibrium porosity. The equilibrium quantity of voids is insensitive to the initial density of the fuel compact. (author)

  6. Nuclear Energy Advanced Modeling and Simulation (NEAMS) Accident Tolerant Fuels High Impact Problem: Coordinate Multiscale FeCrAl Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Gamble, K. A. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Hales, J. D. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Zhang, Y. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Andersson, D. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Capolungo, L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Wirth, B. D. [Univ. of Tennessee, Knoxville, TN (United States)

    2017-07-26

    Since the events at the Fukushima-Daiichi nuclear power plant in March 2011 significant research has unfolded at national laboratories, universities and other institutions into alternative materials that have potential enhanced ac- cident tolerance when compared to traditional UO2 fuel zircaloy clad fuel rods. One of the potential replacement claddings are iron-chromium-alunimum (FeCrAl) alloys due to their increased oxidation resistance [1–4] and higher strength [1, 2]. While the oxidation characteristics of FeCrAl are a benefit for accident tolerance, the thermal neu- tron absorption cross section of FeCrAl is about ten times that of Zircaloy. This neutronic penalty necessitates thinner cladding. This allows for slightly larger pellets to give the same cold gap width in the rod. However, the slight increase in pellet diameter is not sufficient to compensate for the neutronic penalty and enriching the fuel beyond the current 5% limit appears to be necessary [5]. Current estimates indicate that this neutronic penalty will impose an increase in fuel cost of 15-35% [1, 2]. In addition to the neutronic disadvantage, it is anticipated that tritium release to the coolant will be larger because the permeability of hydrogen in FeCrAl is about 100 times higher than in Zircaloy [6]. Also, radiation-induced hardening and embrittlement of FeCrAl need to be fully characterized experimentally [7]. Due to the aggressive development schedule for inserting some of the potential materials into lead test assemblies or rods by 2022 [8] multiscale multiphysics modeling approaches have been used to provide insight into these the use of FeCrAl as a cladding material. The purpose of this letter report is to highlight the multiscale modeling effort for iron-chromium-alunimum (FeCrAl) cladding alloys as part of the Nuclear Energy Advanced Modeling and Simulation (NEAMS) program through its Accident Tolerant Fuel (ATF) High Impact Problem (HIP). The approach taken throughout the HIP is to

  7. Fuel cells applied to transport; Celdas de combustible aplicadas al transporte

    Energy Technology Data Exchange (ETDEWEB)

    Vargas Gonzalez, Miguel [Comision Nacional para el Ahorro de Energia, Mexico, D.F. (Mexico)

    2001-07-01

    The future demand of energy as well as the preservation of the environment have generated, in several countries, the necessity of developing alternative means for the most efficient transformation of energy that causes minimum damages to the environment. The fuel cells technology is outlined as one of the alternating means to the traditional forms of transforming the energy for residential use as well as for the automotive vehicles. At present it is in a final stage of demonstration, reason why as of year 2003 the possibility will exist on automobiles and trucks circulating normally. [Spanish] La futura demanda de energeticos asi como la preservacion del medio ambiente ha generado, en varios paises, la necesidad de desarrollar medios alternos para la transformacion mas eficiente de la energia que cause minimos danos al ambiente. La tecnologia de celdas de combustible se perfila como uno de los medios alternos a la forma tradicional de transformar la energia tanto para uso residencial como para los vehiculos automotores. En la actualidad se encuentra en una etapa final de demostracion por lo que posiblemente a partir del ano 2003 se cuente con automoviles y camiones circulando normalmente.

  8. Prediction of U-Mo dispersion nuclear fuels with Al-Si alloy using artificial neural network

    International Nuclear Information System (INIS)

    Susmikanti, Mike; Sulistyo, Jos

    2014-01-01

    Dispersion nuclear fuels, consisting of U-Mo particles dispersed in an Al-Si matrix, are being developed as fuel for research reactors. The equilibrium relationship for a mixture component can be expressed in the phase diagram. It is important to analyze whether a mixture component is in equilibrium phase or another phase. The purpose of this research it is needed to built the model of the phase diagram, so the mixture component is in the stable or melting condition. Artificial neural network (ANN) is a modeling tool for processes involving multivariable non-linear relationships. The objective of the present work is to develop code based on artificial neural network models of system equilibrium relationship of U-Mo in Al-Si matrix. This model can be used for prediction of type of resulting mixture, and whether the point is on the equilibrium phase or in another phase region. The equilibrium model data for prediction and modeling generated from experimentally data. The artificial neural network with resilient backpropagation method was chosen to predict the dispersion of nuclear fuels U-Mo in Al-Si matrix. This developed code was built with some function in MATLAB. For simulations using ANN, the Levenberg-Marquardt method was also used for optimization. The artificial neural network is able to predict the equilibrium phase or in the phase region. The develop code based on artificial neural network models was built, for analyze equilibrium relationship of U-Mo in Al-Si matrix

  9. Influence of a doping by Al stainless steel on kinetics and character of interaction with the metallic nuclear fuel

    Science.gov (United States)

    Nikitin, S. N.; Shornikov, D. P.; Tarasov, B. A.; Baranov, V. G.

    2016-04-01

    Metallic nuclear fuel is a perspective kind of fuel for fast reactors. In this paper we conducted a study of the interaction between uranium-molybdenum alloy and ferritic- martensitic steels with additions of aluminum at a temperature of 700 ° C for 25 hours. The rate constants of the interaction layer growth at 700 °C is about 2.8.10-14 m2/s. It is established that doping Al stainless steel leads to decrease in interaction with uranium-molybdenum alloys. The phase composition of the interaction layer is determined.

  10. Atomistic modeling and simulation of the role of Be and Bi in Al diffusion in U-Mo fuel

    Science.gov (United States)

    Hofman, G. L.; Bozzolo, G.; Mosca, H. O.; Yacout, A. M.

    2011-07-01

    Within the RERTR program, previous experimental and modeling studies identified Si as the alloying addition to the Al cladding responsible for inhibiting Al interdiffusion in the UMo fuel. However, difficulties with reprocessing have rendered this choice inappropriate, leading to the need to study alternative elements. In this work, we discuss the results of an atomistic modeling effort which allows for the systematic study of several possible alloying additions. Based on the behavior observed in the phase diagrams, beryllium or bismuth additions suggest themselves as possible options to replace Si. The results of temperature-dependent simulations using the Bozzolo-Ferrante-Smith (BFS) method for the energetics for varying concentrations of either element are shown, indicating that Be could have a substantial effect in stopping Al interdiffusion, while Bi does not. Details of the calculations and the dependence of the role of each alloying addition as a function of temperature and concentration (of beryllium or bismuth in Al) are shown.

  11. Atomistic modeling and simulation of the role of Be and Bi in Al diffusion in U-Mo fuel

    Energy Technology Data Exchange (ETDEWEB)

    Hofman, G.L. [Argonne National Laboratory, 9700 S. Cass Ave., Argonne, IL 60439 (United States); Bozzolo, G., E-mail: guille_bozzolo@yahoo.com [Argonne National Laboratory, 9700 S. Cass Ave., Argonne, IL 60439 (United States); Mosca, H.O. [Gerencia de Investigaciones y Aplicaciones, CNEA, Av. Gral Paz 1499, B165KNA, San Martin, Buenos Aires (Argentina); Yacout, A.M. [Argonne National Laboratory, 9700 S. Cass Ave., Argonne, IL 60439 (United States)

    2011-07-15

    Within the RERTR program, previous experimental and modeling studies identified Si as the alloying addition to the Al cladding responsible for inhibiting Al interdiffusion in the UMo fuel. However, difficulties with reprocessing have rendered this choice inappropriate, leading to the need to study alternative elements. In this work, we discuss the results of an atomistic modeling effort which allows for the systematic study of several possible alloying additions. Based on the behavior observed in the phase diagrams, beryllium or bismuth additions suggest themselves as possible options to replace Si. The results of temperature-dependent simulations using the Bozzolo-Ferrante-Smith (BFS) method for the energetics for varying concentrations of either element are shown, indicating that Be could have a substantial effect in stopping Al interdiffusion, while Bi does not. Details of the calculations and the dependence of the role of each alloying addition as a function of temperature and concentration (of beryllium or bismuth in Al) are shown.

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

    Science.gov (United States)

    Greenhill, L. M.

    1990-01-01

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

  13. Post-irradiation examination of Al-61 wt% U3Si fuel rods from the NRU reactor

    International Nuclear Information System (INIS)

    Sears, D.F.; Wang, N.

    1997-01-01

    This paper describes the post-irradiation examination of 4 intact low enrichment uranium (LEU) fuel rods from the national research universal (NRU) reactor at the Chalk River Laboratories of AECL. The rods were irradiated during the period 1993 through 1995, under typical driver fuel operating conditions in NRU, i.e., nominal D 2 O coolant inlet temperature 37E C, inlet pressure 654 kPa and mass flow 12.4 L/s. Irradiation exposures ranged from 147 to 251 full-power days, corresponding to 40 to 84 atom % 235 U burnup. The maximum rod power was ∼2 MW, with element linear power ratings up to 68 kW/m. Post-irradiation examinations, conducted in 1997, focused on optical metallography to measure cladding oxide thickness and fuel core and cladding microstructural examinations. The cladding oxide was approximately 24 : m thick at the mid-plane of fuel rods irradiated to 251 full-power days, with small areas up to 34 : m thick on the fins. The cladding retained significant ductility after irradiation, and its microstructure appeared unchanged. Fuel core diametral increases were small (up to 4%) and within the range previously observed on Al-61 wt% U 3 Si fuel irradiated in the NRU reactor. (author)

  14. Development of MTR fuel plate with U-Al dispersion core constituents

    International Nuclear Information System (INIS)

    Bressiani, Jose Carlos

    1979-01-01

    This work is a contribution to the development of fuel plates for Research Nuclear Reaction Materials Test Reactors. The plates have the core constituted by dispersions of metallic uranium in aluminum. The main topics of this work are: 1) The preparation of uranium powder with particle sizes in the 53-105μm diameter range; 2) The mixture and cold-pressing of uranium and aluminum powders for different uranium concentrations; 3) The behavior of the dispersions in the roll milling conditions; 4) Blister, radiographic, metallographic and irradiation tests for quality control of the plates. The irradiation test was performed in the IEA-R1 swimming-pool reactor using a prototype with a dispersion of aluminum and natural uranium (45 w/o ), reaching an integrated neutron flux of 8.663 X 10 18 n/cm 2 , no visual changes being noticed after the completion of the experiment. The behavior of the uranium-aluminum reaction for dispersions with 45% w/o uranium also studied. X-ray diffraction experiments showed the formation of UAl 2 UAl 3 and UAl 4 , while energy dispersive analysis of X-rays(EDAX) demonstrated that the diffusion of aluminum in uranium is the mechanism responsible for that reaction. The activation energy for the U-Al reaction was determined by dilatometric experiments yielding 20.2 kcal/mol.The aluminum-uranium reaction reaches an end when extended to 96 h at 600 deg C, namely, when all the uranium is found in the UAl 4 composition. (author)

  15. Improving 6061-Al Grain Growth and Penetration across HIP-Bonded Clad Interfaces in Monolithic Fuel Plates: Initial Studies

    Energy Technology Data Exchange (ETDEWEB)

    Hackenberg, Robert E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); McCabe, Rodney J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Montalvo, Joel D. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Clarke, Kester D. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Dvornak, Matthew J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Edwards, Randall L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Crapps, Justin M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Trujillo, R. Ralph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Aikin, Beverly [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Vargas, Victor D. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Hollis, Kendall J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Lienert, Thomas J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Forsyth, Robert T. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Harada, Kiichi L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2013-05-06

    Grain penetration across aluminum-aluminum cladding interfaces in research reactor fuel plates is desirable and was obtained by a legacy roll-bonding process, which attained 20-80% grain penetration. Significant grain penetration in monolithic fuel plates produced by Hot Isostatic Press (HIP) fabrication processing is equally desirable but has yet to be attained. The goal of this study was to modify the 6061-Al in such a way as to promote a much greater extent of crossinterface grain penetration in monolithic fuel plates fabricated by the HIP process. This study documents the outcomes of several strategies attempted to attain this goal. The grain response was characterized using light optical microscopy (LOM) electron backscatter diffraction (EBSD) as a function of these prospective process modifications done to the aluminum prior to the HIP cycle. The strategies included (1) adding macroscopic gaps in the sandwiches to enhance Al flow, (2) adding engineering asperities to enhance Al flow, (3) adding stored energy (cold work), and (4) alternative cleaning and coating. Additionally, two aqueous cleaning methods were compared as baseline control conditions. The results of the preliminary scoping studies in all the categories are presented. In general, none of these approaches were able to obtain >10% grain penetration. Recommended future work includes further development of macroscopic grooving, transferred-arc cleaning, and combinations of these with one another and with other processes.

  16. Development of the Melt-Dilute Treatment Technology for Al-Based DOE Spent Nuclear Fuel

    International Nuclear Information System (INIS)

    Peacock, H.B.; Adams, T.M.; Iyer, N.C.

    1998-09-01

    Spent foreign and domestic research reactor fuel assemblies will be sent to Savannah River Site and prepared for interim and eventual geologic storage. Many of the fuel plates have been made with high enriched uranium, and during long term storage, the integrity of the fuel maybe effected if the canister is breached. To reduce the potential for criticality, proliferation, and reduce storage volume, a new treatment technology called melt-dilute is being developed at SRS. The technique will melt the spent fuel assemblies and will dilute the isotopic content to below 20%. The process is simple and versatile

  17. Study on the Applicability of Electron Beam Welding Methods to Assembly a Fuel Compact and Al Cover Plate of Research Reactor Plate Type Fuel

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hae In; Lee, Yoon Sang; Lee, Don Dae; Jeong, Yong Jin; Kwon, Sun Chil; Kim, Soo Sung; Park, Jong Man [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2012-05-15

    Among the research reactor plate type fuel fabrication processes, there is an assembly process between fuel meat compact and Al cover plates using a welding method prior to rolling process. The assembly process is such as the Al frame and Al cover plate should be welded properly as shown in Fig. 1. For welding, TIG(Tungsten Inert Gas) welding methods has been used conventionally, but in this study an electron beam welding(EB welding) technique which uses the electron beam of a high velocity for joining two materials is introduced to the assembly. The work pieces are melted as the kinetic energy of the electron beam is transformed into heat to join the two parts of the weld. The welding is often done in the conditions in a vacuum to prevent dispersion of the electron beam. The electron beam welding process has many ad-vantages such as contamination of the welds could be prevented, the penetration of the weld is deep, and also the strain of the welding area is less than other methods. In this study, to find optimal condition of the EB welding process, a welding speed, a beam current and an acceleration voltage were changed. To analyzing the welding results, the shape of the beads and defects of welding area was used. The width and depth of the beads were measured as well

  18. Study on the Applicability of Electron Beam Welding Methods to Assembly a Fuel Compact and Al Cover Plate of Research Reactor Plate Type Fuel

    International Nuclear Information System (INIS)

    Lee, Hae In; Lee, Yoon Sang; Lee, Don Dae; Jeong, Yong Jin; Kwon, Sun Chil; Kim, Soo Sung; Park, Jong Man

    2012-01-01

    Among the research reactor plate type fuel fabrication processes, there is an assembly process between fuel meat compact and Al cover plates using a welding method prior to rolling process. The assembly process is such as the Al frame and Al cover plate should be welded properly as shown in Fig. 1. For welding, TIG(Tungsten Inert Gas) welding methods has been used conventionally, but in this study an electron beam welding(EB welding) technique which uses the electron beam of a high velocity for joining two materials is introduced to the assembly. The work pieces are melted as the kinetic energy of the electron beam is transformed into heat to join the two parts of the weld. The welding is often done in the conditions in a vacuum to prevent dispersion of the electron beam. The electron beam welding process has many ad-vantages such as contamination of the welds could be prevented, the penetration of the weld is deep, and also the strain of the welding area is less than other methods. In this study, to find optimal condition of the EB welding process, a welding speed, a beam current and an acceleration voltage were changed. To analyzing the welding results, the shape of the beads and defects of welding area was used. The width and depth of the beads were measured as well

  19. Atomistic modelling of the interdiffusion of Al in the UMo based fuel

    International Nuclear Information System (INIS)

    Garces, Jorge E.; Marino, Armando C.; Bozzolo, Guillermo

    2002-01-01

    The analysis of the initial stages and trends in the process of interdiffusion of Al in the UMo solid solution as a function of Mo concentration is made using the BFS method for alloys. The approach presented in this work helps to understand the exchange mechanism between adatoms and substrate atoms in the binary systems, leading to the behavior observed in the ternary Al-U-Mo system. While in Al/U Al atoms show a noticeable tendency to interdiffusion in the bulk, in Al/Mo the same atoms show a tendency to layer-by-layer growth and the formation of structures in the overlayer. In the case of Al/U-Mo, the two competing behaviors observed for Al/Mo and Al/U, translate into the role of regions rich in Mo acting as interdiffusion barriers, in excellent agreement with experimental evidence. (author)

  20. Microstructure and Physical Metallurgy in Melt-Dilute Treatment Technology for Al-Based Spent Nuclear Fuel

    International Nuclear Information System (INIS)

    Adams, T.M.; Peacock, H.B.

    1998-09-01

    Major challenges associated with the direct disposal of research reactor fuel in a repository include nonproliferation and criticality control, both of which may be a concern for HEU Al-SNF. Consideration must be given to the potential desirability and/or regulatory necessity of diluting the HEU SNF to below 20 percent enrichment. The probability for a criticality event as well as the issue of proliferation are greatly decreased by reducing the enrichment. The melt-dilute technology development program is focused on the development and implementation of a treatment technology for diluting HEU Al-SNF to LEU levels and qualifying this LEU Al-SNF form for geologic repository storage. An attribute of the melt-dilute process is its applicability to various types of FRR and DRR SNF

  1. Polystyrene Plastic Waste Conversion into Liquid Fuel with Catalytic Cracking Process Using Al2O3 as Catalyst

    Directory of Open Access Journals (Sweden)

    Nurul Kholidah

    2018-01-01

    Full Text Available The increase in energy consumption and an increase in the plastic waste generation are two major problems that arise along with economic growth and the increase in population. Styrofoam is one type of polystyrene plastic waste that can be processed into liquid fuels by cracking process. In this study, the cracking process of polystyrene plastic waste into liquid fuel carried by the catalytic cracking process using Al2O3 as a catalyst. This study aimed to determine the effect of the catalyst weight, length of cracking time and range of temperature in the catalytic cracking process of polystyrene plastic waste into liquid fuel toward the mass and characteristics of liquid fuels produced and to determine the composition of liquid fuels produced. The catalytic cracking process of polystyrene plastic waste with catalyst was done in the fixed bed type reactor by heating the reactor with a heater, where the process took place at temperature of 150°C, 200°C, 250°C and 300°C and the length of the process was varied into 20, 40, and 60 minutes and the catalyst weight was also varied, which were 4%, 6% and 8%, while the styrofoam weight was 250 grams. From the research, the highest mass of liquid fuel derived from polystyrene catalytic cracking process was in the amount of 48.8 grams and liquid yield percentage of 19.5% at temperature of  250°C, cracking time of 60 minutes and weight of 8% catalyst, while the characteristics of liquid fuel that were approaching the characteristics of gasoline was at temperatures of 250°C, cracking time of 60 minutes and weight of 6% catalyst, in which each value of density of 0.763 g/ml, specific gravity of 0.778 and oAPI gravity of 50.2. While other liquid fuels obtained from the cracking of polystyrene were still within the tolerance range characteristic properties of gasoline. Liquid fuels produced from the catalytic cracking process was analyzed using a GC-MS, in which the analysis results indicated that liquid

  2. Study of the U3O8-Al thermite reaction and strength of reactor fuel tubes

    International Nuclear Information System (INIS)

    Peacock, H.B.

    1984-01-01

    Research and test reactors are presently operated with aluminum-clad fuel elements containing highly enriched uranium-aluminum alloy cores. To lower the enrichment and still maintain reactivity, the uranium content of the fuel element will need to be higher than currently achievable with alloy fuels. This will necessitate conversion to other forms such as U 3 O 8 -aluminum cermets. Above the aluminum melting point, U 3 O 8 and aluminum undergo an exothermic thermite reaction and cermet fuel cores tend to keep their original shape. Both factors could affect the course and consequences of a reactor accident, and therefore prompted an investigation of the behavior of cermet fuels at elevated temperatures. Tests were carried out using pellets and extruded tube sections with 53 wt % U 3 O 8 in aluminum. This content corresponds to a theoretical uranium density of 1.9 g/cc. Results indicate that the thermite reaction occurs at about 900 0 C in air without a violent effect. The heat of reaction was approximately 123 cal/g of U 3 O 8 -aluminum fuel. Tensile and compressive strength of the fuel tube section is low above 660 0 C. In tension, sections failed at about the aluminum melting point. In compression with 2 psi average axial stress, failure occurred at 917 0 C, while 7 psi average axial stress produced failure at 669 0 C. (author)

  3. Study of the U3O8-Al thermite reaction and strength of reactor fuel tubes

    International Nuclear Information System (INIS)

    Peacock, H.B.

    1983-01-01

    Research and test reactors are presently operated with aluminum-clad fuel elements containing highly enriched uranium-aluminum alloy cores. To lower the enrichment and still maintain reactivity, the uranium content of the fuel element will need to be higher than currently achievable with alloy fuels. This will necessitate conversion to other forms such as U 3 O 8 -aluminum cermets. Above the aluminum melting point, U 3 O 8 and aluminum undergo an exothermic thermite reaction and cermet fuel cores tend to keep their original shape. Both factors could affect the course and consequences of a reactor accident, and prompted an investigation of the behavior of cermet fuels at elevated temperatures. Tests were carried out using pellets and extruded tube-sections with 53 wt % U 3 O 8 in aluminum. This content corresponds to a theoretical uranium density of 1.9 g/cc. Results indicate that the thermite reaction occurs at about 900 0 C in air without a violent effect. The heat of reaction was approximately 123 cal/g of U 3 O 8 -aluminum fuel. Tensile and compressive strength of the fuel tube section is low above 660 0 C. In tension, sections failed at about the aluminum melting point. In compression with 2-psi average axial stress, failure occurred at 917 0 C, while 7 psi average axial stress produced failure at 669 0 C

  4. Cold spray deposition of Ti{sub 2}AlC coatings for improved nuclear fuel cladding

    Energy Technology Data Exchange (ETDEWEB)

    Maier, Benjamin R. [University of Wisconsin, Madison, WI (United States); Garcia-Diaz, Brenda L. [Savannah River National Laboratory, Aiken, SC (United States); Hauch, Benjamin [University of Wisconsin, Madison, WI (United States); Olson, Luke C.; Sindelar, Robert L. [Savannah River National Laboratory, Aiken, SC (United States); Sridharan, Kumar, E-mail: kumar@engr.wisc.edu [University of Wisconsin, Madison, WI (United States)

    2015-11-15

    Coatings of Ti{sub 2}AlC MAX phase compound have been successfully deposited on Zircaloy-4 (Zry-4) test flats, with the goal of enhancing the accident tolerance of LWR fuel cladding. Low temperature powder spray process, also known as cold spray, has been used to deposit coatings ∼90 μm in thickness using powder particles of <20 μm. X-ray diffraction analysis showed the phase-content of the deposited coatings to be identical to the powders indicating that no phase transformation or oxidation had occurred during the coating deposition process. The coating exhibited a high hardness of about 800 H{sub K} and pin-on-disk wear tests using abrasive ruby ball counter-surface showed the wear resistance of the coating to be significantly superior to the Zry-4 substrate. Scratch tests revealed the coatings to be well-adhered to the Zry-4 substrate. Such mechanical integrity is required for claddings from the standpoint of fretting wear resistance and resisting wear handling and insertion. Air oxidation tests at 700 °C and simulated LOCA tests at 1005 °C in steam environment showed the coatings to be significantly more oxidation resistant compared to Zry-4 suggesting that such coatings can potentially provide accident tolerance to nuclear fuel cladding. - Highlights: • Deposited Ti{sub 2}AlC coatings on Zircaloy-4 substrates with a low pressure powder spray process, also known as cold spray. • Coatings have high hardness and wear resistance for both damage resistance during rod insertion and fretting wear resistance. • The oxidation resistance of Ti{sub 2}AlC coated Zircaloy-4 at 700 °C and 1005 °C was significantly superior to uncoated Zircaloy. • Cold spray of Ti{sub 2}AlC demonstrates considerable promise as a near-term solution for accident tolerant Zr-alloy fuel claddings.

  5. The UMo Powder Production Process of UMo-Al Dispersion Fuel for Research Reactor has been Studied

    International Nuclear Information System (INIS)

    Supardjo

    2007-01-01

    Development of UMo-Al dispersion fuel with low enrichment uranium ( 3 ), a relatively large range of γ phase and easily reprocessed. Using UMo alloy as nuclear fuel, uranium density can be increased until 9.0 g/cm 3 , is higher than that of U 3 Si 2 -Al fuel that has only maximum Uranium density 6.0 g/cm 3 . Because of ductility of UMo alloy, thus exact and economic powder production method is needed. Some powder production methods are mechanical crushing (milling, grinding, etc), cryogenic mechanical crushing, atomization, and Hydride-Dehydride. The mechanical crushing and cryogenic mechanical crushing methods are difficult to be performed, time consuming and have high impurity products. However, atomization and hydride-dehydride methods are performed easily, fast and have low impurity products. The product of atomization process is spherical and uniform shape, but, another processes have irregular shape. The evaluation result of some methods showed that hydride-dehydride and atomization methods are more suitable for producing UMo powder than that of another methods. (author)

  6. Consideraciones sobre afectividad en las relaciones de enseñanza: las contribuciones de Vigotski

    Directory of Open Access Journals (Sweden)

    Raimundo Nonato de Oliveira Falabelo

    2015-10-01

    Full Text Available Este artigo tiene como objetivo presentar conclusiones de un estudio sobre la cuestión afectiva en una perspectiva inter-relacional con la cognición, como una misma unidad, que es la vida psíquica humana, lo que significa concebir que el afecto está presente y es constitutivo de toda y cualquier acción humana. Tiene como base teórica los estudios realizados por L. S. Vigotski. Echamos mano, aún, de las contribuciones de algunos de sus comentadores o interpretadores que tratan específicamente de este tema. El texto hace parte de los fundamentos teóricos de la Tesis de Doctorado sobre esta problemática, en contexto empírico, de clase, en un aula de educación de jóvenes y adultos.

  7. Contribuciones bibliográficas de la Facultad de Farmacia y Bioquímica

    OpenAIRE

    Bonilla Rivera, Pablo E.

    2014-01-01

    La contribución bibliográfica de la facultad de Farmacia y Bioquímica de San Marcos es muy importante, pero tal vez poco conocida en los claustros sanmarquinos. Por ello, a partir de este número, "Ciencia e Investigación" incluirá las listas de las contribuciones hechas por los docentes de la facultad y por los exalumnos a través de sus tesis de título y de grados académicos. La contribución bibliográfica de la facultad de Farmacia y Bioquímica de San Marcos es muy importante, pero tal vez...

  8. Examination of U3Si2-Al fuel elements from the Oak Ridge Research Reactor

    International Nuclear Information System (INIS)

    Copeland, G.L.; Snelgrove, J.L.; Hofman, G.L.

    1986-01-01

    The results of postirradiation examination of low-enriched U 3 Si 2 fuel elements from the Oak Ridge Research Reactor are presented. The elements replaced standard high-enriched elements and were handled routinely except that the burnup of half the elements was extended beyond normal limits up to about 98% peak. The elements were manufactured by commercial fuel suppliers. The performance was completely satisfactory for all the elements

  9. Development of PRIME for irradiation performance analysis of U-Mo/Al dispersion fuel

    Science.gov (United States)

    Jeong, Gwan Yoon; Kim, Yeon Soo; Jeong, Yong Jin; Park, Jong Man; Sohn, Dong-Seong

    2018-04-01

    A prediction code for the thermo-mechanical performance of research reactor fuel (PRIME) has been developed with the implementation of developed models to analyze the irradiation behavior of U-Mo dispersion fuel. The code is capable of predicting the two-dimensional thermal and mechanical performance of U-Mo dispersion fuel during irradiation. A finite element method was employed to solve the governing equations for thermal and mechanical equilibria. Temperature- and burnup-dependent material properties of the fuel meat constituents and cladding were used. The numerical solution schemes in PRIME were verified by benchmarking solutions obtained using a commercial finite element analysis program (ABAQUS). The code was validated using irradiation data from RERTR, HAMP-1, and E-FUTURE tests. The measured irradiation data used in the validation were IL thickness, volume fractions of fuel meat constituents for the thermal analysis, and profiles of the plate thickness changes and fuel meat swelling for the mechanical analysis. The prediction results were in good agreement with the measurement data for both thermal and mechanical analyses, confirming the validity of the code.

  10. Development of PRIME for irradiation performance analysis of U-Mo/Al dispersion fuel

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Gwan Yoon; Kim, Yeon Soo; Jeong, Yong Jin; Park, Jong Man; Sohn, Dong-Seong

    2018-04-01

    A prediction code for the thermo-mechanical performance of research reactor fuel (PRIME) has been developed with the implementation of developed models to analyze the irradiation behavior of U-Mo dispersion fuel. The code is capable of predicting the two-dimensional thermal and mechanical performance of U-Mo dispersion fuel during irradiation. A finite element method was employed to solve the governing equations for thermal and mechanical equilibria. Temperature-and burnup-dependent material properties of the fuel meat constituents and cladding were used. The numerical solution schemes in PRIME were verified by benchmarking solutions obtained using a commercial finite element analysis program (ABAQUS).The code was validated using irradiation data from RERTR, HAMP-1, and E-FUTURE tests. The measured irradiation data used in the validation were IL thickness, volume fractions of fuel meat constituents for the thermal analysis, and profiles of the plate thickness changes and fuel meat swelling for the mechanical analysis. The prediction results were in good agreement with the measurement data for both thermal and mechanical analyses, confirming the validity of the code. (c) 2018 Elsevier B.V. All rights reserved.

  11. Emerging methanol-tolerant AlN nanowire oxygen reduction electrocatalyst for alkaline direct methanol fuel cell.

    Science.gov (United States)

    Lei, M; Wang, J; Li, J R; Wang, Y G; Tang, H L; Wang, W J

    2014-08-11

    Replacing precious and nondurable Pt catalysts with cheap materials is a key issue for commercialization of fuel cells. In the case of oxygen reduction reaction (ORR) catalysts for direct methanol fuel cell (DMFC), the methanol tolerance is also an important concern. Here, we develop AlN nanowires with diameters of about 100-150 nm and the length up to 1 mm through crystal growth method. We find it is electrochemically stable in methanol-contained alkaline electrolyte. This novel material exhibits pronounced electrocatalytic activity with exchange current density of about 6.52 × 10(-8) A/cm(2). The single cell assembled with AlN nanowire cathodic electrode achieves a power density of 18.9 mW cm(-2). After being maintained at 100 mA cm(-2) for 48 h, the AlN nanowire-based single cell keeps 92.1% of the initial performance, which is in comparison with 54.5% for that assembled with Pt/C cathode. This discovery reveals a new type of metal nitride ORR catalyst that can be cheaply produced from crystal growth method.

  12. Post-irradiation examination of U3SIX-AL fuel element manufactured and irradiated in Argentina

    International Nuclear Information System (INIS)

    Ruggirello, Gabriel; Calabroni, Hector; Sanchez, Miguel; Hofman, Gerard

    2002-01-01

    As a part of CNEA's qualification program as a supplier of low enriched Al-U 3 Si 2 dispersion fuel elements for research reactors, a post irradiation examination (PIE) of the first prototype of this kind, called P-04, manufactured and irradiated in Argentina, was carried out. The main purpose of this work was to set up various standard PIE techniques in the hot cell, looking forward to the next steps of the qualification program, as well as to acquire experience on the behaviour of this nuclear material and on the control of the manufacturing process. After an appropriate cooling period, on May 2000 the P-04 was transported to the hot cell in Ezeiza Atomic Centre. Non destructive and destructive tests were performed following the PIE procedures developed in Argonne National Laboratory (ANL), this mainly included dimensional measurement, microstructural observations and chemical burn-up analyses. The methodology and results of which are outlined in this report. The results obtained show a behaviour consistent with that of other fuel elements of the same kind, tested previously. On the other hand the results of this PIE, specially those concerning burn-up analysis and stability and corrosion behaviour of the fuel plates, will be of use for the IAEA Regional Program on the characterization of MTR spent fuel. (author)

  13. Post-irradiation examination of prototype Al-64 wt% U{sub 3}Si{sub 2} fuel rods from NRU

    Energy Technology Data Exchange (ETDEWEB)

    Sears, D.F.; Primeau, M.F.; Buchanan, C.; Rose, D. [Chalk River Labs., Ontario (Canada)

    1997-08-01

    Three prototype fuel rods containing Al-64 wt% U{sub 3}Si{sub 2} (3.15 gU/cm{sup 3}) have been irradiated to their design burnup in the NRU reactor without incident. The fuel was fabricated using production-scale equipment and processes previously developed for Al-U{sub 3}Si fuel fabrication at Chalk River Laboratories, and special equipment developed for U{sub 3}Si{sub 2} powder production and handling. The rods were irradiated in NRU up to 87 at% U-235 burnup under typical driver fuel conditions; i.e., nominal coolant inlet temperature 37{degrees}C, inlet pressure 654 kPa, mass flow 12.4 L/s, and element linear power ratings up to 73 kW/m. Post-irradiation examinations showed that the fuel elements survived the irradiation without defects. Fuel core diametral increases and volumetric swelling were significantly lower than that of Al-61 wt% U{sub 3}Si fuel irradiated under similar conditions. This irradiation demonstrated that the fabrication techniques are adequate for full-scale fuel manufacture, and qualified the fuel for use in AECL`s research reactors.

  14. Evaluation of Metals (Al, Fe, Zn) in Alternative Fuels by Electrochemical Impedance Spectroscopy in Two Electrode Cell

    International Nuclear Information System (INIS)

    Song, Yon Kyun; Lim, Geun Woong; Kim, Hee San

    2010-01-01

    Many kinds of alternative fuels such as biodiesel, ethanol, methanol, and natural gas have been developed in order to overcome the limited deposits in fossil fuels. In some cases, the alternative fuels have been reported to cause degrade materials. The corrosion rates of metals were measured by immersion test, a kind of time consuming test because low conductivity of these fuels was not allowed to employ electrochemical tests. With twin two-electrode cell newly designed for the study, however, electrochemical impedance spectroscopy (EIS) test was successfully applied to evaluation of the corrosion resistance (R p ) of zinc, iron, aluminum, and its alloys in an oxidized biodiesel and gasoline/ethanol solutions and the corrosion resistance from EIS was compared with the corrosion rate from immersion test. In biodiesel, R p increased in the order of zinc, iron, and aluminum, which agreed with the corrosion resistance measured from immersion test. In addition, on aluminum showing the best corrosion resistance (R p ), the effect of magnesium as an alloying element was evaluated in gasoline/ethanol solutions as well as the oxidized biodiesel. R p increased with addition of magnesium in gasoline/ethanol solutions containing chloride and the oxidized biodiesel. In the mean while, in gasoline/ethanol solutions containing formic acid, Al-Mg alloy added 1% magnesium had the highest R p and the further addition of magnesium decreased R p . It can be explained with the fact that the addition of more than 1% magnesium increases the passive current density of Al-Mg alloys

  15. The Recovery of Uranium From The Rejected Fuel Plate Dispersion Type of U3O8-Al and U3Si2Al by NaOH

    International Nuclear Information System (INIS)

    Widodo, G; Aji, D

    1998-01-01

    The recovery of uranium from the rejected fuel plate dispersion type of U 3 O 8 -AI And U 3 Si 2 -AI with a dissolution has been performed.Each of 5 fragment of fuel plate dispersion of U 3 O 8 -AI or U 3 Si 2 Al of 1x4 cm size was put in the distilled glass content of 250 ml NaOH solution whit The concentration variation 10,15,20,25,and 30%,and than was heated at temperature of 102 o C and was stirred constantly by magnetic stirred.Uranium in the form of U 3 O 8 or U 3 Si 2 was separated by filtration and Either residu and filtrate was analyzed by potentiometry using modified Devies Gray method. From the experiment data it was found in the residu that presentation of uranium was 83.99-84.05% and 84.67-86.556% while in filtrate it was found 53.90 ppm and 69.3 ppm

  16. Pt/Al/sub 2/O/sub 3/- carbon nanocomposite as a catalyst for fuel cells

    International Nuclear Information System (INIS)

    Naeem, R.; Ahmed, R.; Ansari, M.S.

    2013-01-01

    Catalysts comprising platinum nanoparticles (Pt NPs) on carbon support are used in fuel cells for the hydrogen and electricity production by electrochemical oxidation of methanol. However, the catalyst is not the best in terms of its performance. Considering role of the support as significant towards efficiency and durability of the catalyst, there is need for introducing novel support materials to replace carbon alone. Deposition of various metallic NPs on ceramic-carbon (hybrid) supports has been reported to improve thermal, mechanical, electrical and chemical properties of different types of catalyst. In search of better performing catalysts for proton exchange membrane fuel cells (PEMFCs), hybrid supports having different ceramic materials should be synthesized. In this regard Pt/Al/sub 2/O/sub 3/-Carbon (nanocomposites) have been synthesized and applied as promising catalysts in the PEMFCs; results obtained for the nanocomposites were compared with Pt/carbon and Pt/Al/sub 2/O/sub 3/. Vulcan carbon was purified and functionalized prior to use; presence of oxygen containing functional groups on carbon was established from the FTIR spectrum, Hybrid support (1:8 by weight ratio of ceramic and carbon) were already prepared in aqueous 2-propanol employing sonication method on to which Pt NPs (10% by weight in all the cases) were deposited by simple chemical reduction of PtCl/sub 4/ by NaBH/sub 4/ under controlled conditions. The catalysts were subjected to various characterization techniques like TGA (for thermal stability), EDX (for chemical composition), SEM (for surface morphology) and XRD (for cell-shape and -volume, material density and average crystalline size). Catalysts efficiencies for the methanol oxidation were investigated through cyclic voltammetery (CV) by comparing electrochemical surface area, peak current, exchange current density and rate constant in the acidic and basic media. Pt/Al/sub 2/O/sub 3/-carbon exhibited better catalytic efficiencies

  17. Fission gas behaviour and interdiffusion layer growth in in-pile and out-of-pile irradiated U-Mo/Al nuclear fuels

    International Nuclear Information System (INIS)

    Zweifel, Tobias

    2014-01-01

    Worldwide, research and test reactors are to convert their fuel from highly towards lower enriched uranium, among them the FRM II. One prospective fuel is an alloy of uranium and molybdenum (abbr. U-Mo). Test irradiations showed an insufficient irradiation behavior of this new fuel due to the growth of an interdiffusion layer (abbr. IDL) between the U-Mo fuel and the surrounding Al matrix. Furthermore, this layer accumulates fission gases. In this work, heavy ion irradiated U-Mo/Al layer systems were studied and compared to in-reactor irradiated fuel to study the fission gas dynamics. It is demonstrated that the gas behavior is identical for both in-reactor and out-of-reactor approaches.

  18. Interaction of Al2O3xSiO2 alloyed uranium oxide with pyrocarbon coating of fuel particles under irradiation

    International Nuclear Information System (INIS)

    Chernikov, A.S.; Khromov, Yu.F.; Svistunov, D.E.; Chujko, E.E.

    1989-01-01

    Method of comparative data analysis for P O2 and P CO was used to consider interaction in fuel particle between pyrocarbon coating and fuel sample, alloyed with alumosilicate addition. Equations of interaction reactions for the case of hermetic and depressurized fuel particle are presented. Calculations of required xAl 2 O 3 XySiO 2 content, depending on oxide fuel burnup, were conducted. It was suggested to use silicon carbide for limitation of the upper level of CO pressure in fuel particle. Estimation of thermal stability of alumosilicates under conditions of uranium oxide burnup equals 1100 and 1500 deg C for Al/Si ratio in addition 1/1 and 4/1 respectively

  19. Corrosion of research reactor Al-clad spent fuel in water

    International Nuclear Information System (INIS)

    Bendereskaya, O.S.; De, P.K.; Haddad, R.; Howell, J.P.; Johnson, A.B. Jr.; Laoharojanaphand, S.; Luo, S.; Ramanathan, L.V.; Ritchie, I.; Hussain, N.; Vidowsky, I.; Yakovlev, V.

    2002-01-01

    A significant amount of aluminium-clad spent nuclear fuel from research and test reactors worldwide is currently being stored in water-filled basins while awaiting final disposition. As a result of corrosion issues, which developed from the long-term wet storage of aluminium-clad fuel, the International Atomic Energy Agency (IAEA) implemented a Co-ordinated Research Project (CRP) in 1996 on the 'Corrosion of Research Reactor Aluminium-Clad Spent Fuel in Water'. The investigations undertaken during the CRP involved ten institutes in nine different countries. The IAEA furnished corrosion surveillance racks with aluminium alloys generally used in the manufacture of the nuclear fuel cladding. The individual countries supplemented these racks with additional racks and coupons specific to materials in their storage basins. The racks were immersed in late 1996 in the storage basins with a wide range of water parameters, and the corrosion was monitored at periodic intervals. Results of these early observations were reported after 18 months at the second research co-ordination meeting (RCM) in Sao Paulo, Brazil. Pitting and crevice corrosion were the main forms of corrosion observed. Corrosion caused by deposition of iron and other particles on the coupon surfaces was also observed. Galvanic corrosion of stainless steel/aluminium coupled coupons and pitting corrosion caused by particle deposition was observed. Additional corrosion racks were provided to the CRP participants at the second RCM and were immersed in the individual basins by mid-1998. As in the first set of tests, water quality proved to be the key factor in controlling corrosion. The results from the second set of tests were presented at the third and final RCM held in Bangkok, Thailand in October 2000. An IAEA document giving details about this CRP and other guidelines for spent fuel storage is in pres. This paper presents some details about the CRP and the basis for its extension. (author)

  20. Application of laser ablation inductivly coupled plasma mass spectrometry for characterization of U-7Mo/Al-55i dispersion fuels

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jeong Mook; Park, Jai Il; Youn, Young Sang; Ha, Yeong Keong; Kim, Jong Yun [Nuclear Chemistry Research Division, Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2017-04-15

    This technical note demonstrates the feasibility of using laser ablation inductively coupled plasma mass spectrometry for the characterization of U–7Mo/Al–5Si dispersion fuel. Our measurements show 5.0% Relative Standard Deviation (RSD) for the reproducibility of measured {sup 98}Mo/{sup 238}U ratios in fuel particles from spot analysis, and 3.4% RSD for {sup 98}Mo/{sup 238}U ratios in a NIST-SRM 612 glass standard. Line scanning allows for the distinction of U–7Mo fuel particles from the Al–5Si matrix. Each mass spectrum peak indicates the presence of U–7Mo fuel particles, and the time width of each peak corresponds to the size of that fuel particle. The size of the fuel particles is estimated from the time width of the mass spectrum peak for {sup 98}Mo by considering the scan rate used during the line scan. This preliminary application clearly demonstrates that laser ablation inductively coupled plasma mass spectrometry can directly identify isotope ratios and sizes of the fuel particles in U–Mo/Al dispersion fuel. Once optimized further, this instrument will be a powerful tool for investigating irradiated dispersion fuels in terms of fission product distributions in fuel matrices, and the changes in fuel particle size or shape after irradiation.

  1. Special equipment support the fuel storage; Equipos especiales para apoyos al almacenamiento de combustible

    Energy Technology Data Exchange (ETDEWEB)

    Vega, M. E.

    2014-10-01

    In the current juncture one of the keys to any company that works in a market that is as demanding as the nuclear, is its ability to developed new technological products that they can adapt to the different special situations/needs of nuclear Power Plants during their operating life. As an example, below are some of the specialized equipment that ENSA has been developing for more than thirty years that has been doing work in the area of fuel storage. (Author)

  2. Analysis of hydrogen, carbon, sulfur and volatile compounds in (U3Si2 - Al) nuclear fuel

    International Nuclear Information System (INIS)

    Moura, Sergio C.; Redigolo, Marcelo M.; Amaral, Priscila O.; Leao, Claudio; Oliveira, Glaucia A.C. de; Bustillos, Oscar V.

    2015-01-01

    Uranium silicide U 3 Si 2 is used as nuclear fuel in the research nuclear reactor IEA-R1 at IPEN/CNEN, Sao Paulo, Brazil. The U 3 Si 2 is dispersed in aluminum reaching high densities of uranium in the nucleus of the fuel, up to 4.8 gU cm -3 . This nuclear fuel must comply with a quality control, which includes analysis of hydrogen, carbon and sulfur for the U 3 Si 2 and volatile compound for the aluminum. Hydrogen, carbon and sulfur are analyzed by the method of Radio Frequency gas extraction combustion coupled with Infrared detector. Volatile compounds are analyzed by the method of heated gas extraction coupled with gravimetric measurement. These methods are recommended by the American Society for Testing Materials (ASTM) for nuclear materials. The average carbon and sulfur measurements are 30 μg g -1 and 3 μg g -1 , respectively, and 40 μg g -1 for volatile compounds. The hydrogen analyzer is a TCHEN 600 LECO, carbon and sulfur analyzer is a CS 244 LECO and the volatile compounds analyzer is a home-made apparatus that use a resistant furnace, a gas pipe measurement and a glove-box with controlled atmosphere where an analytical balance has been installed, this analyzer was made at IPEN laboratory. (author)

  3. Fabrication of high-uranium-loaded U{sub 3}O{sub 8}-Al developmental fuel plates

    Energy Technology Data Exchange (ETDEWEB)

    Copeland, G L; Martin, M M [Oak Ridge National Laboratory, TN (United States)

    1983-08-01

    A common plate-type fuel for Research and Test Reactors (RERTR) is U{sub 3}0{sub 8} dispersed in aluminum and clad with an aluminum alloy. There is an impetus to reduce the {sup 235}U enrichment from above 90% to below 20% for these fuels to lessen the risk of diversion of the uranium for non-peaceful uses. Thus, the uranium content of the fuel plates has to be increased to maintain the performance of the reactors. This paper describes work at ORNL to determine the maximal uranium loading for these fuels that can be fabricated with commercially proven materials and techniques and that can be expected to perform satisfactorily in service. We fabricated developmental fuel plates with cores containing from 60 to 100 wt U{sub 3}0{sub 8} in aluminum encapsulated in 6061 aluminum alloy and evaluated them for aspects of fabricability, nondestructive testing, and expected performance. We recommend 75 wt U{sub 3}0{sub 8}-Al 3.1 Mg U/m{sup 3}) as the highest loading in the initial irradiation test. This upper limit is based on a qualitative assessment of the mechanical integrity of the core made by using current fabrication techniques and materials. As the oxide loading is increased beyond this point, planar areas and extensive stringers of oxide and voids develop, which leave little strength in the thickness direction. Fuel plates may then blister over these areas as fission gases collect during irradiation. Current size plates are easily fabricable to the 75 wt % U{sub 3}0{sub 8}-Al core loading by current fabrication techniques. Dogboning is a potential problem at this loading for some applications; however, this can be easily solved by using tapered compact ends. Current nondestructive radiography and transmission x-ray scanning are applicable to the highly loaded plates. Ultrasonic testing for non-bonds is marginal because of the abrupt change in conductance at the cladding-core interface. Plate thickness can be increased if desired; we fabricated 75 wt % plates with

  4. Development of low-Cr ODS FeCrAl alloys for accident-tolerant fuel cladding

    Science.gov (United States)

    Dryepondt, Sebastien; Unocic, Kinga A.; Hoelzer, David T.; Massey, Caleb P.; Pint, Bruce A.

    2018-04-01

    Low-Cr oxide dispersion strengthened (ODS) FeCrAl alloys were developed as accident tolerant fuel cladding because of their excellent oxidation resistance at very high temperature, high strength and improved radiation tolerance. Fe-12Cr-5Al wt.% gas atomized powder was ball milled with Y2O3+FeO, Y2O3+ZrO2 or Y2O3+TiO2, and the resulting powders were extruded at 950 °C. The resulting fine grain structure, particularly for the Ti and Zr containing alloys, led to very high strength but limited ductility. Comparison with variants of commercial PM2000 (Fe-20Cr-5Al) highlighted the significant impact of the powder consolidation step on the alloy grain size and, therefore, on the alloy mechanical properties at T < 500 °C. These low-Cr compositions exhibited good oxidation resistance at 1400 °C in air and steam for 4 h but could not form a protective alumina scale at 1450 °C, similar to observations for fine grained PM2000 alloys. The effect of alloy grain size, Zr and Ti additions, and impurities on the alloy mechanical and oxidation behaviors are discussed.

  5. High-Uranium-Loaded U3O8-Al fuel element development program. Part 2

    International Nuclear Information System (INIS)

    Knight, R.

    1993-01-01

    Texas Instruments is a product intensive company that manufactures very high volumes of different products, and because of this, their technique in manufacturing is what we call hard tooling. So all of the tools we use at this site whether it is for HFIR, ORR or HFBR are hard tooling. A fuel plate never sees a lathe, milling machine, or any other tool of that nature. I have just a few viewgraphs here that will illustrate some of the types of tooling we use to keep away from machining and get high production at as low as possible cost. Figure I shows weighing aluminum powder. It's done in a glove box more to keep air flow away from the balance than any other reason. The weighing of the U 3 O 8 is similar and the glove box is for personnel protection. Figure 2 shows our blender, and I won't try to explain why it works. This is the only one we have ever found that really blends our powder and does a good job. Figure 3 shows our powder die on the press, and you can see the rectangular compact being extracted. Here is the way we make our frames in a blanking die Figure 4. You will notice there are two holes in the frame. We start off with two cores in a frame. Our lot size is 24, but twelve billets go into the furnace for preheating, at the seventh pass, we cut the two cores apart and at that point they become individual fuel plates. Figure 5 shows the loading of the compacts into the frame. We use a loose fit. We can just drop the cores into the frame with, I think, about 2 mils side clearance and it works very satisfactorily. Figure 6 shows a forming die. Once you make the investment for the fuel plate blanking die shown in Figure 7, you can blank out a fuel plate on the order of about one per minute, to size and to the tolerances required. Figure 8 shows a unique tool developed at Oak Ridge. It's a Homogeneity Scanner. It works on the principal of x-ray attenuation going through an electronic analysis

  6. Investigation of electrorefining of metallic alloy fuel onto solid Al cathodes

    International Nuclear Information System (INIS)

    Cassayre, L.; Malmbeck, R.; Masset, P.; Rebizant, J.; Serp, J.; Soucek, P.; Glatz, J.-P.

    2007-01-01

    This work concerned the electrorefining of UZr and UPuZr alloys on a solid aluminium cathode, in the LiCl-KCl eutectic melt containing U 3+ , Pu 3+ , Np 3+ , Zr 2+ or Zr 4+ , Am 3+ , Nd 3+ , Y 3+ , Ce 3+ and Gd 3+ chlorides. During constant current electrolyses, the use of a cathodic cut-off potential (-1.25 V versus Ag/AgCl) allowed to selectively deposit actinides (mainly U), while lanthanides remained in the salt. The aim was to determine the maximal load achievable on a single aluminium electrode. The total exchange charge was 4300 C, which represents the deposition of 3.72 g of actinides in 4.17 g Al, yielding a composition of 44.6 wt% An in Al. It was shown that the melting of the cathode contributed to increase the total amount of actinides deposited on the aluminium

  7. Postirradiation Examination Of U3O8-AL Plate Type Dispersion Fuel Element

    International Nuclear Information System (INIS)

    Nasution-Hasbullah; Sugondo; Amin, D.L.; Siti-Amini

    1996-01-01

    Postirradiation examination of plate type spent fuel element RIE-01 has been carried out in order to observer its physical changes and performance under irradiation in the reactor. The irradiation has been time more than two years with a declared burnup of 51.04 %. The examination included visual and dimensional measurement, measurement of burn-up distribution, wipe test and metallographic analysis. The results showed that all fuel plates retained their integrity. The colour changes were occurred on most of the plates significant suggesting that it was generated from the oxide layer formation. From gamma-scanning examination it could be deducted that the highest burn-up distribution of the plate was at position of 30 cm from the bottom. A more homogeneous distribution was found in the middle plate of the bundle. The increased plate thickness, as revealed by dimensional measurements as in agreement with the burn-up distribution pattern. Despite the changes observed in could be concluded that all changes occurred were still within the allowable limits and therefore it can recommended that an increase of the burn-up level above 51,04 % is still quite possible

  8. Proporcionalidad y equidad en las contribuciones. El amparo fiscal en México, 1917-1968

    Directory of Open Access Journals (Sweden)

    Carlos de Jesús Becerril Hernández

    2015-01-01

    Full Text Available El juicio de amparo ha sido comúnmente identificado como parte del proceso de la modernización jurídica liberal de la segunda mitad del siglo XIX. No obstante, el amparo fiscal, que tiene que ver directamente con el reclamo por la proporcionalidad y equidad de las contribuciones contenidas en el artículo 31, fracción IV, de la Constitución Política de los Estados Unidos Mexicanos de 1917, no fue reconocido como jurisprudencia inmediatamente aplicable; el criterio del ministro Ignacio L. Vallarta (1830-1893 sobre la incapacidad de la Corte para conocer de este recurso fue vigente hasta bien entrado el siglo XX. El amplio arco temporal (1917-1968 cubierto por este ensayo tratará de explicar, a la luz del derecho constitucional y del desempeño económico, por qué la justicia federal se negó a amparar y proteger a los causantes, bajo el argumento de que la Corte no era juez ni órgano revisor de las leyes expedidas por el Congreso.

  9. Use of pyrolysis gas from coal as reburn fuel. Final report; Einsatz von kohlestaemmigem Pyrolysegas als Reduktionsbrennstoff. Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Greul, U.; Magel, C.; Moersch, O.; Ruediger, H.; Storm, C.; Schnell, U.; Spliethoff, H.; Hein, K.R.G.

    1996-12-31

    The research project`s aim was to reduce nitrogen emissions from pulverized-coal furnaces by fuel staging with pyrolysis gas from coal. The test fuels were 6 German and Australian coals. The aim achieved has been the statement that the described method is an adequate means to attain to and remain below emission values of 200 mg/m{sup 3}. The method of fuel staging using coal-original gases was investigated with tests focussing the most important process parameters such as coal type, devolatilization ratio, temperature, residence time, and stoichiometry. The relevant features determined with an entrained flow reactor and with a fluidized-bed reactor were the impact of devolatilization temperatures on carbonized residue and pyrolysis products, the distribution of fuel nitrogen, and the quality of gas and tar, including the respective effects on NO{sub x} formation and reduction in staged combustion. The validation of the mathematical model was done with the experimentally obtained data. The criteria considered fundamental for achieving the NO{sub x} reduction level are temperature, air ratio, and residence time in the reduction zone of the furnace. The pyrolysis tests manifested the strong influence of the coal type and the devolatilization conditions on the composition of the gases and the attainable NO{sub x} reduction. The tars in the pyrolysis gases, with their nitrogen compounds, improve the reducing effect of available nitrogen oxides. By using pyrolysis gases from coal as reburning fuel, NO{sub x} emissions of less than 200 mg/m{sup 3} can be obtained at air ratios around 0.95. (orig./SR) [Deutsch] Das Forschungsprojekt verfolgte das Ziel mit 6 deutschen und australischen Kohlen die Stickoxidemissionen aus Kohlestaubfeuerungen durch Brennstoffstufung mit Pyrolysegas als Reduktionsbrennstoff zu verringern. Das erreichte Ziel war der Nachweis, dass mit dem beschriebenen Verfahren NO{sub x}-Emissionswerte von 200 mg/m{sup 3} erreicht und unterschritten werden

  10. Analysis of transuranic isotopes in irradiated U3Si2-Al fuel by alpha spectrometry

    International Nuclear Information System (INIS)

    Dian Anggraini; Aslina B Ginting; Arif Nugroho

    2011-01-01

    Separation and analysis of transuranic isotopes (uranium and plutonium) in irradiated U 3 Si 2 -Al plate has been done. The analysis experiment includes sample preparation (i.e. cutting, dissolving, filtering, dilution), fission products separation from heavy elements, and analysis of transuranic isotopes content with alpha spectrometer. The separation of transuranic isotopes (U, Pu) was done by two methods, i.e. direct method and ion exchanger method with zeolite. Measurement of standard transuranic isotope (AMR 43) and standard U 3 O 8 was done in advance in order to determine percentage of 235 U recovery and detector efficiency. Recovery of 235 U isotope was obtained as much as 92,58%, which fulfills validation requirement, and the detector efficiency was 0.314. Based on the measured recovery and detector efficiency, the separation was done by direct electrodeposition method of 250 µL irradiated U 3 Si 2 -Al solution. The deposited sample was subsequently analyzed with alpha spectrometer. The separation with ion exchanger was done by mixing and shaking of 300 µL irradiated U 3 Si 2 -Al solution and 0.5 gram zeolite to separate the liquid phase from the solid phase. The liquid phase was electrodeposited and analyzed with alpha spectrometer. The analysis of transuranic isotopes (U, Pu) by both methods shows different results. Heavy element ( 238 U, 236 U, 234 U, 239 Pu) content obtained by direct method was 0.0525 g/g and 235 U= 0.0076 g/g, while the separation using zeolite ion exchanger resulted in Heavy element = 0.0253 g/g and 235 U = 0.0092 g/g. (author)

  11. Behavior of U3Si2 Fuel and FeCrAl Cladding under Normal Operating and Accident Reactor Conditions

    International Nuclear Information System (INIS)

    Gamble, Kyle Allan Lawrence; Hales, Jason Dean; Barani, Tommaso; Pizzocri, Davide; Pastore, Giovanni

    2016-01-01

    As part of the Department of Energy's Nuclear Energy Advanced Modeling and Simulation program, an Accident Tolerant Fuel High Impact Problem was initiated at the beginning of fiscal year 2015 to investigate the behavior of \\usi~fuel and iron-chromium-aluminum (FeCrAl) claddings under normal operating and accident reactor conditions. The High Impact Problem was created in response to the United States Department of Energy's renewed interest in accident tolerant materials after the events that occurred at the Fukushima Daiichi Nuclear Power Plant in 2011. The High Impact Problem is a multinational laboratory and university collaborative research effort between Idaho National Laboratory, Los Alamos National Laboratory, Argonne National Laboratory, and the University of Tennessee, Knoxville. This report primarily focuses on the engineering scale research in fiscal year 2016 with brief summaries of the lower length scale developments in the areas of density functional theory, cluster dynamics, rate theory, and phase field being presented.

  12. Examen de auditoría integral a las contribuciones de mejoras por el período comprendido entre el 1 de Enero y el 31 de diciembre del 2012, en el Gobierno Municipal del Cantón Morona

    OpenAIRE

    Valencia Zabala, Liliam Margot

    2014-01-01

    En el presente trabajo de investigación trata sobre una auditoría integral al Gobierno Municipal del Cantón Morona, se han diseñado capítulos que se relacionan con el desarrollo de una auditoría integral a las contribuciones de mejoras, que ha sido desarrollado con el aporte de los funcionarios auditados y se ha evaluado con los conocimientos adquiridos en esta maestría. Se han utilizado conceptos claves, que son parte fundamental de la auditoría integral como son: auditoría de gesti...

  13. Investigation of electrorefining of metallic alloy fuel onto solid Al cathodes

    Energy Technology Data Exchange (ETDEWEB)

    Cassayre, L. [European Commission, Joint Research Centre, Institute for Transuranium Elements, P.O. 2340, 76125 Karlsruhe (Germany); Malmbeck, R. [European Commission, Joint Research Centre, Institute for Transuranium Elements, P.O. 2340, 76125 Karlsruhe (Germany)]. E-mail: rikard.malmbeck@cec.eu.int; Masset, P. [European Commission, Joint Research Centre, Institute for Transuranium Elements, P.O. 2340, 76125 Karlsruhe (Germany); Rebizant, J. [European Commission, Joint Research Centre, Institute for Transuranium Elements, P.O. 2340, 76125 Karlsruhe (Germany); Serp, J. [European Commission, Joint Research Centre, Institute for Transuranium Elements, P.O. 2340, 76125 Karlsruhe (Germany); Soucek, P. [European Commission, Joint Research Centre, Institute for Transuranium Elements, P.O. 2340, 76125 Karlsruhe (Germany); Glatz, J.-P. [European Commission, Joint Research Centre, Institute for Transuranium Elements, P.O. 2340, 76125 Karlsruhe (Germany)

    2007-01-15

    This work concerned the electrorefining of UZr and UPuZr alloys on a solid aluminium cathode, in the LiCl-KCl eutectic melt containing U{sup 3+}, Pu{sup 3+}, Np{sup 3+}, Zr{sup 2+} or Zr{sup 4+}, Am{sup 3+}, Nd{sup 3+}, Y{sup 3+}, Ce{sup 3+} and Gd{sup 3+} chlorides. During constant current electrolyses, the use of a cathodic cut-off potential (-1.25 V versus Ag/AgCl) allowed to selectively deposit actinides (mainly U), while lanthanides remained in the salt. The aim was to determine the maximal load achievable on a single aluminium electrode. The total exchange charge was 4300 C, which represents the deposition of 3.72 g of actinides in 4.17 g Al, yielding a composition of 44.6 wt% An in Al. It was shown that the melting of the cathode contributed to increase the total amount of actinides deposited on the aluminium.

  14. Metallographic analysis of irradiated U3Si2/Al fuel element plate of 2.96 gU/cm3 density

    International Nuclear Information System (INIS)

    Maman Kartaman Ajiriyanto; Aslina Br Ginting; Junaedi

    2018-01-01

    Metallographic analysis of U 3 Si 2 /Al fuel element plate has been performed in hot cell. The purpose of metallographic analysis is to study changes in PEB U 3 Si 2 /Al microstructure and AlMg 2 cladding thickness after irradiation in reactor until burn up of 56 %. The fuel element plate of irradiated U 3 Si 2 /Al was cut in top, middle and bottom positions with each size around 5 x 5 x 1.37 mm. Metallographic preparation starts from sample cutting using cutting machine with low speed and sample mounting, grinding and polishing in hot cell 104–105. Sample mounting was done by using resin for more than 10 hours followed by grinding with sand papers up to grit size of 2400 and polishing with diamond paste of size 3 to 1 micron at a rotational speed of 150 rpm for 5 minutes. Microstructure observation was performed with optical microscope in hot cell 107 at 200 times magnification. Microstructure examination reveals U 3 Si 2 particles with inverse forms and sizes, Al matrix and AlMg 2 cladding were spread along the U 3 Si 2 /Al side. Microstructure observation of irradiated U 3 Si 2 /Al has not shown good result because only topography observation of U 3 Si 2 /Al meat, Al matrix and AlMg 2 cladding can be done due to limited capability of the optical microscope in hot cell, where maximum magnification can be attained only at 200 times so that the phenomenon of interaction layer and small gas bubble can not be observed. However, U 3 Si 2 /Al microstructure of 56 % burnup, if compared to the microstructure of U 3 Si 2 /Al fuel element plate of 60 % burnup from previous researcher, shows interaction between U 3 Si 2 meat with Al matrix and the existence of layers with a thickness about 5 up to 20 microns. Meanwhile, the observed thickness of AlMg 2 cladding is greater than 0.25 mm, which indicates that irradiation does not significantly change the thickness of AlMg 2 cladding so that the overall irradiated U 3 Si 2 -Al still has good integrity and stability. (author)

  15. Use of pyrolysis gases from biogenic fuels as reductionfuels in coal dust furnaces; Einsatz von Pyrolysegasen aus biogenen Brennstoffen als Reduktionsbrennstoff in Kohlestaubfeuerungen

    Energy Technology Data Exchange (ETDEWEB)

    Ruediger, H.; Greul, U.; Spliethoff, H.; Hein, K.R.G. [Stuttgart Univ. (Germany). Inst. fuer Verfahrenstechnik und Dampfkesselwesen (IVD)

    1996-12-31

    Co-combustion of refuse-derived fuels in the form of pyrolysis gases, with coal as primary fuel, has advantages in terms of fuel ash separation and nitric oxide emissions. Biomass or sewage sludge is degassed in a pyrolysis reactor, and the gas is used as secondary fuel in a coal dust furnace. The authors investigated the influence of reaction temperature, fuel moisture and reaction atmosphere in the pyrolysis stage on the product fractions gas, tar, and residual fuel, as well as the suitability of the resulting pyrolysis gas as secondary fuel in a coal dust furnace for the purpose of reducing nitric oxide emissions. (orig) [Deutsch] Ein am IVD betriebenes Konzept der Mitverbrennung von Brennstoffen in Form von Pyrolysegasen bietet Vorteile bezueglich der Trennung der Brennstoffaschen und Stickoxidemissionen bei der Feuerung des Primaerbrennstoffes Steinkohle. Biomasse oder Klaerschlamm wird hierbei in einem Pyrolysereaktor engast und gasfoermig als Sekundaerbrennstoff in einer Kohlenstaubfeuerung eingesetzt. Untersuchungsschwerpunkte in der Pyrolysestufe des Prozesses waren die Einfluesse von Reaktionstemperatur, Brennstofffeuchte und Reaktionsatmosphaere auf die Produktfraktionen Gas, Teer und Restbrennstoff sowie die Eignung des erzeugten Pyrolysegases als Sekundaerbrennstoff in einer Kohlenstaubfeuerung zur Senkung derKohlendioxidemissione. (orig)

  16. Use of pyrolysis gases from biogenic fuels as reductionfuels in coal dust furnaces; Einsatz von Pyrolysegasen aus biogenen Brennstoffen als Reduktionsbrennstoff in Kohlestaubfeuerungen

    Energy Technology Data Exchange (ETDEWEB)

    Ruediger, H; Greul, U; Spliethoff, H; Hein, K R.G. [Stuttgart Univ. (Germany). Inst. fuer Verfahrenstechnik und Dampfkesselwesen (IVD)

    1997-12-31

    Co-combustion of refuse-derived fuels in the form of pyrolysis gases, with coal as primary fuel, has advantages in terms of fuel ash separation and nitric oxide emissions. Biomass or sewage sludge is degassed in a pyrolysis reactor, and the gas is used as secondary fuel in a coal dust furnace. The authors investigated the influence of reaction temperature, fuel moisture and reaction atmosphere in the pyrolysis stage on the product fractions gas, tar, and residual fuel, as well as the suitability of the resulting pyrolysis gas as secondary fuel in a coal dust furnace for the purpose of reducing nitric oxide emissions. (orig) [Deutsch] Ein am IVD betriebenes Konzept der Mitverbrennung von Brennstoffen in Form von Pyrolysegasen bietet Vorteile bezueglich der Trennung der Brennstoffaschen und Stickoxidemissionen bei der Feuerung des Primaerbrennstoffes Steinkohle. Biomasse oder Klaerschlamm wird hierbei in einem Pyrolysereaktor engast und gasfoermig als Sekundaerbrennstoff in einer Kohlenstaubfeuerung eingesetzt. Untersuchungsschwerpunkte in der Pyrolysestufe des Prozesses waren die Einfluesse von Reaktionstemperatur, Brennstofffeuchte und Reaktionsatmosphaere auf die Produktfraktionen Gas, Teer und Restbrennstoff sowie die Eignung des erzeugten Pyrolysegases als Sekundaerbrennstoff in einer Kohlenstaubfeuerung zur Senkung derKohlendioxidemissione. (orig)

  17. Deformation behavior of laser welds in high temperature oxidation resistant Fe–Cr–Al alloys for fuel cladding applications

    Energy Technology Data Exchange (ETDEWEB)

    Field, Kevin G., E-mail: fieldkg@ornl.gov; Gussev, Maxim N., E-mail: gussevmn@ornl.gov; Yamamoto, Yukinori, E-mail: yamamotoy@ornl.gov; Snead, Lance L., E-mail: sneadll@ornl.gov

    2014-11-15

    Ferritic-structured Fe–Cr–Al alloys are being developed and show promise as oxidation resistant accident tolerant light water reactor fuel cladding. This study focuses on investigating the weldability and post-weld mechanical behavior of three model alloys in a range of Fe–(13–17.5)Cr–(3–4.4)Al (wt.%) with a minor addition of yttrium using modern laser-welding techniques. A detailed study on the mechanical performance of bead-on-plate welds using sub-sized, flat dog-bone tensile specimens and digital image correlation (DIC) has been carried out to determine the performance of welds as a function of alloy composition. Results indicated a reduction in the yield strength within the fusion zone compared to the base metal. Yield strength reduction was found to be primarily constrained to the fusion zone due to grain coarsening with a less severe reduction in the heat affected zone. For all proposed alloys, laser welding resulted in a defect free weld devoid of cracking or inclusions.

  18. Deformation behavior of laser welds in high temperature oxidation resistant Fe-Cr-Al alloys for fuel cladding applications

    Science.gov (United States)

    Field, Kevin G.; Gussev, Maxim N.; Yamamoto, Yukinori; Snead, Lance L.

    2014-11-01

    Ferritic-structured Fe-Cr-Al alloys are being developed and show promise as oxidation resistant accident tolerant light water reactor fuel cladding. This study focuses on investigating the weldability and post-weld mechanical behavior of three model alloys in a range of Fe-(13-17.5)Cr-(3-4.4)Al (wt.%) with a minor addition of yttrium using modern laser-welding techniques. A detailed study on the mechanical performance of bead-on-plate welds using sub-sized, flat dog-bone tensile specimens and digital image correlation (DIC) has been carried out to determine the performance of welds as a function of alloy composition. Results indicated a reduction in the yield strength within the fusion zone compared to the base metal. Yield strength reduction was found to be primarily constrained to the fusion zone due to grain coarsening with a less severe reduction in the heat affected zone. For all proposed alloys, laser welding resulted in a defect free weld devoid of cracking or inclusions.

  19. O sentido do ser-mãe-que-tem-a-possibilidade-de-tocar-o-filho-prematuro na unidade intensiva: contribuições para a enfermagem neonatal El significado de ser la madre-que-tiene-la-posibilidad-de-tocar-al-hijo-prematuro en la unidad de cuidados intensivos: contribuciones para la enfermería neonatal The meaning of being the mother-that-has-the-possibility-to-touch-the-premature-baby in the intensive unit: contributions for the neonatal nursing

    Directory of Open Access Journals (Sweden)

    Rita de Cássia de Jesus Melo

    2012-06-01

    Full Text Available Estudo na abordagem teórico-metodológica heideggeriana com o objetivo de desvelar o sentido do ser-mãe que tem a possibilidade de tocar o filho prematuro na UTIN. Após aprovação foi desenvolvida entrevista fenomenológica com nove mulheres-mães. A análise compreensiva constituiu oito unidades de significação, e a hermenêutica permitiu desvelar o movimento existencial do sermãe em sua cotidianidade, nos modos de ser da inautenticidade e impessoalidade, movida pelo falatório, ambiguidade e temor, modos de ocupação. Ao compreender como sua a possibilidade de ter um filho prematuro, toca-o cautelosamente e cuidadosamente, transita para um entendimento no qual não mais se ocupa, se preo-cupa. Ao pre-ocupar, o ser-mãe estabelece a possibilidade de ser-aí-com-o-filho. Foi possível entender este modo de ser mãe, no qual passa por estágios antes de ver o bebê como seu e confiar em si. Possibilitar que toque seu filho, compreendendo-a em sua individualidade, singularidade, mostrou-se como um cuidado ao RNP em sua complexidade como ser-aí.Estudio en el enfoque teórico-metodológico heideggeriana con el objetivo de revelar el sentido del ser la madre que tiene la possibilidad de tocar el hijo prematuro en una Unidad de Cuidados Intensivos Neonatal. Después de la aprobación, fue desarrollada una entrevista fenomenológica con nueve madres. El análisis comprehensivo constituyó ocho unidades de significación, la hermenéutica permitió revelar el movimiento existencial del ser madre en su cotidianidad, en los modos de ser de la falta de autenticidad e impersonalidad, movida por el chisme, la ambigüedad y miedo, modos de ocupación. Al comprender como de ella la posibilidad de tener un bebé prematuro, lo toca con cautela y cuidado, transita para un entendimiento en el cual no más se ocupa, se preocupa. Al preocuparse, el ser madre establece la posibilidad de ser-ahí-con-el-hijo. Fue posible entender este modo de ser madre, que

  20. A Contribution to the Study of the Oxidation of Uranium Monocarbide in Carbonic Anhydride at High Temperatures; Contribution a l'etude de l'oxydation du monocarbure d'uranium dans l'anhydride carbonique aux temperatures elevees; Vklad v izuchenie voprosa okisleniya monokarbida urana v ugol'nom angidride pri povyshennykh temperaturakh; Contribucion al estudio de la oxidacion del monocarburo de uranio en anhidrido carbonico a temperaturas elevadas

    Energy Technology Data Exchange (ETDEWEB)

    Desrues, R; Paidassi, J.; Darras, R. [Centre d' Etudes Nucleaires, Saclay (France)

    1963-11-15

    fragmentation progressive des echantillons. Les augmentations de poids trouvees sont d'ailleurs nettement plus faibles que celles publiees jusqu'a ce jour, ce qu'il faut tres vraisemblablement attribuer a une purete plus grande de l'anhydride carbonique mis en oeuvre et a une porosite particulierement faible du monocarbure d'uranium utilise. 2. La presence d'inclusions dans le monocarbure, qu'elles correspondent a de l'uranium ou a du dicarbure, diminue la resistance a.l'oxydation de ce materiau, ce qu'il faut surtout imputer au fait que celles-ci subissent une oxydation catastrophique, notamment par suite des contraintes mecaniques qu' elles introduisent. 3. Dans tous les cas, le processus d'oxydation peut etre caracterise par une energie d'activation egale a 29 000 cal/mole, valeur tres voisine de celle qui correspond a l'oxydation de l'uranium metallique dans le meme gaz, et a la diffusion de l'oxygene dans l'oxyde d'uranium (UO{sub 2}) forme. (author) [Spanish] Los autores tomaron muestras de monocarburo de uranio, obtenidas por dos procedimientos distintos, y de un cermet compuesto de 96,7% de U y 3,3% de C (en peso), las sometieron a la accion del anhidrido carbonico practicamente exento de oxigeno y vapor de agua, en un intervalo de temperaturas de 350 a 600 deg. C; observaron el progreso de la oxidacion por gravimetria (con una termobalanza de Eyraud) y por micrografia a la vez. Llegaron a las siguientes conclusiones: 1. Al principio, las graficas que representan los aumentos de peso en funcion del tiempo son sensiblemente rectilineas, pero luego su pendiente se acentua, lo que se explica sobre todo por la fragmentacion progresiva de las muestras. Por otra parte, los aumentos de peso verificados son netamente inferiores a los datos publicados hasta el presente, lo que cabe atribuir muy probablemente a la mayor pureza del anhidrido carbonico utilizado y a la porosidad particularmente baja del monocarburo de uranio empleado. 2. La presencia de inclusiones en el

  1. Deoxygenation of palm kernel oil to jet fuel-like hydrocarbons using Ni-MoS_2/γ-Al_2O_3 catalysts

    International Nuclear Information System (INIS)

    Itthibenchapong, Vorranutch; Srifa, Atthapon; Kaewmeesri, Rungnapa; Kidkhunthod, Pinit; Faungnawakij, Kajornsak

    2017-01-01

    Highlights: • The Ni-MoS_2/γ-Al_2O_3 catalysts synthesized using thiourea solution processing. • The Ni-MoS_2 showed semi-amorphous crystallinity with crystallite size of 5–10 nm. • The Ni K-edge XANES and EXAFS indicated the Ni substitution in MoS_2 structure. • A high yield of jet fuel-like hydrocarbon (>90%) from the palm kernel oil feedstock. • The HDO pathway was highly selective, while the DCO_2 and DCO pathways were minor. - Abstract: In the current study, palm kernel oil was used as a renewable feedstock for production of jet fuel-like hydrocarbons via the deoxygenation over the Ni-MoS_2/γ-Al_2O_3 catalyst. The dominant C12 fatty acid content in palm kernel oil makes it promising for jet fuel application. Synthesized by a liquid processing method with thiourea organosulfur agent, the catalyst revealed MoS_2 structure with low stacking, while Ni substitution in the MoS_2 structure and interaction with the Al_2O_3 support were determined based on the Ni K-edge XANES and EXAFS results. A high hydrodeoxygenation (HDO) activity, which as the major pathway in the deoxygenation, was observed upon application of a H_2 pressure of 30–50 bar over Ni-MoS_2/γ-Al_2O_3. The optimum product yield of approximately 92% was obtained mainly from the HDO pathway (∼60%) with 58% selectivity to C10–C12 jet fuel hydrocarbons. The flow property of the jet fuel-like hydrocarbons was more desirable than those obtained from palm olein oil-derived fuel.

  2. Representações de gênero nas relações estudante de enfermagem e cliente: contribuições ao processo de ensino-aprendizagem Representaciones de género en las relaciones estudiante de enfermería y cliente: contribuciones al proceso enseñanza-aprendizaje Gender representations in nursing student and client relations: contributions to the learning process

    Directory of Open Access Journals (Sweden)

    Renata de Lima Muroya

    2011-02-01

    Full Text Available O objetivo do estudo foi Identificar, conhecer e aprofundar o conhecimento sobre as relações de gênero entre estudantes e clientes na prática do cuidado de enfermagem. Estudo de abordagem qualitativa fundamentado nos pressupostos da representação social e analisado à luz dos referenciais teóricos de gênero. Utilizou-se a técnica Teoria do Núcleo Central. Os resultados foram organizados em uma árvore máxima a partir da qual emergiram como elementos periféricos dois eixos temáticos: "A tríade igualdade/diferença/desigualdade no cuidado de enfermagem" e "A falta de preparo: a lacuna no ensino". Os resultados expressam uma dificuldade por parte dos(as estudantes em prestar cuidado ao gênero que não é o seu; revelam um discurso ancorado na percepção das diferenças sexuais e na crença de uma heterossexualidade presumidaEl objetivo del estudio fue identificar, conocer y profundizar los conocimiento sobre las relaciones de género entre estudiantes y clientes en la práctica del cuidado de enfermería. Estudio de abordaje cualitativa fundamentado en los presupuestos de la representación social y analisado bajo la luz de los referenciales teóricos de género. Se utilizó la técnica Teoría del Núcleo Central. Los resultados fueron organizados en un árbol máxima a partir de la cual emergieron como elementos periféricos dos ejes temáticos: "La triade igualdad/diferencia/desigualdad en el cuidado de enfermería" y "La falta de preparación: la laguna en la enseñanza". Los resultados expresan una dificultad por parte de los (las estudiantes en prestar cuidado al género que no es el suyo; revelan un discurso basado en la percepción de las diferencias sexuales y el la creencia de una supuesta heterosexualidadThe purpose of the study was to identity, to know, and to improve the knowledge about the relationships of gender among the students and the clients in the practice of nursing care. That was a qualitative study, based in

  3. Effects of MnO-Al2O3 on the grain growth and high-temperature deformation strain of UO2 fuel pellets

    International Nuclear Information System (INIS)

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

    2010-01-01

    The fabrication and high-temperature deformation strain of MnO-Al 2 O 3 -doped UO 2 pellets were studied. The effects of additive composition and amount on the microstructure evolution of a UO 2 pellet were investigated. The compressive creep behaviors of MnO-Al 2 O 3 -doped UO 2 pellets were examined. The results indicated that a MnO-Al 2 O 3 binary additive can effectively promote the grain growth of UO 2 pellets. In addition, the high-temperature deformation strain of the UO 2 pellet can be improved significantly with 1,000 ppm 95MnO-5Al 2 O 3 (mol%). The developed MnO-Al 2 O 3 -additive-containing UO 2 pellets can be a potential candidate for a high-burn-up fuel and a pellet-cladding interaction (PCI) remedy. (author)

  4. Application of non-destructive methods for qualification of the U3O8-Al and U3Si2-Al dispersion fuels in the IEA-R1 Reactor

    International Nuclear Information System (INIS)

    Silva, Jose Eduardo Rosa da

    2011-01-01

    IPEN/CNEN-SP manufactures fuels to be used in its nuclear research reactor - the IEA-R1. To qualify those fuels, it is necessary to check if they have a good performance under irradiation. As Brazil doesn't have nuclear research reactors with high neutron fluxes, or suitable hot cells for carrying out post-irradiation examination of nuclear fuels, IPEN/CNEN-SP has conducted a fuel qualification program based on the use of uranium compounds, internationally tested and qualified to be used in research reactors, and has gotten experience in the technological development stages for the manufacturing of fuel plates, irradiation and non-destructive post-irradiation testing. Fuel elements containing low volume fractions of fuel in the dispersion were manufactured and irradiated successfully directly in the core of the IEA-R1. However, there are plans to increase the uranium density of these fuels. The objective of this thesis work was to study and to propose a set of non-destructive methods to qualify the dispersions fuels U 3 O 8 -Al e U 3 Si 2 -Al with high uranium density produced at IPEN/CNEN-SP. For that, the irradiation resources in the IEA-R1, and the application of non-destructive methods in the reactor pool available in the Institution were considered. The proposal is to specify, manufacture and irradiate fuel mini plates in IEA-R1 at the maximum densities, qualified internationally, and to monitor their general conditions during the period of irradiation, using non-destructive methods in the reactor pool. In addition to the non-destructive visual inspection and sipping methods, already used at the Institution, the infrastructure for dimensional sub-aquatic testing to evaluate the swelling of irradiated fuel mini plates was completed. The analyses of the results will provide means to assess and decide whether or not to continue with the irradiation of mini plates, until the desired burnup for the irradiation tests at IEA-R1 are reached. (author)

  5. Fe Al40, a new canning material for reactors using refractory fuels; Le Fe Al40, un nouveau materiau de gainage pour les reacteurs a combustibles refractaires

    Energy Technology Data Exchange (ETDEWEB)

    Sainfort, G; Cabane, G; Salesse, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-07-01

    Fe Al40, owing to its high aluminium content, is more suitable than stainless steels for nuclear applications; it has two advantages: its nuclear cross section is half that of 18-10 stainless steels, and its compatibility with fuel elements and heat extracting fluids is exceptionally good. Ferrous alloys with more than 16 per cent by weight of aluminium are reputed to be brittle because of their ordered lattice. But actually, most of the brittleness of these alloys is due to the presence of intergranular precipitates. The vacuum casting of pure iron and aluminium, together with additions of scavenging elements, gives a very clean alloy with sufficiently reduced brittleness at high temperatures as to allow transformation with a very good yield. Studies of smelting and transformation have enabled the optimum composition and the best industrial fabrication conditions to be established. The mechanical properties of extruded or rolled products are dependent, on the ferritic ordered structure of the alloys prepared as follows: Extension at room temperature between 8 and 11 p.100, continuous increase of the elongation at rupture with increase of temperature so that at 800 C it exceeds 100 p.100; yield strength stable at 30 kg/mm{sup 2} from 20 to 550 C; progressive decrease of impact strength as the temperature increases Creep strength at 650-700 C in the region of 10 kg/mm{sup 2} with a very high elongation because of the appearance of a fine grain recrystallization during the test. Welding of Fe Al40 is facilitated by the fact that this alloy remains ferritic up to its melting point (1350 C); however it. is sensitive to hot short cracking and grain swelling. Several welding processes have been successfully applied to this alloy, under conditions where the superficial alumina layer was removed. This very impervious oxide skin gives Fe Al 40 a unique resistance to corrosion: in carbon dioxide at 700 C, 60 atm, the weight gain after 3000 h is about one third of that of a

  6. Comparison of quartz tuning forks and AlN-based extensional microresonators for viscosity measurements in oil/fuel mixtures

    Science.gov (United States)

    Toledo, J.; Manzaneque, T.; Hernando-García, J.; Vazquez, J.; Ababneh, A.; Seidel, H.; Lapuerta, M.; Sánchez-Rojas, J. L.

    2013-05-01

    In-situ monitoring of the physical properties of liquids is of great interest in the automotive industry. For example, lubricants are subject to dilution with diesel fuel as a consequence of late-injection processes, which are necessary for regenerating diesel particulate filters. This dilution can be determined by tracking the viscosity and the density of the lubricant. Here we report the test of two in-plane movement based resonators to explore their capability to monitor oil dilution with diesel and biodiesel. One of the resonators is the commercially available millimeter-sized quartz tuning fork, working at 32.7 kHz. The second resonator is a state-of-the-art micron-sized AlN-based rectangular plate, actuated in the first extensional mode in the MHz range. Electrical impedance measurements were carried out to characterize the performance of the structures in various liquid media in a wide range of viscosities. These measurements were completed with the development of low-cost electronic circuits to track the resonance frequency and the quality factor automatically, these two parameters allow to obtain the viscosity of various fluids under investigation, as in the case of dilution of lubricant SAE 15W40 and biodiesel.

  7. A modelling study of the inter-diffusion layer formation in U-Mo/Al dispersion fuel plates at high power

    Energy Technology Data Exchange (ETDEWEB)

    Ye, B.; Hofman, G. L.; Leenaers, A.; Bergeron, A.; Kuzminov, V.; Van den Berghe, S.; Kim, Y. S.; Wallin, H.

    2018-02-01

    Post irradiation examinations of full-size U-Mo/Al dispersion fuel plates fabricated with ZrN- or Sicoated U-Mo particles revealed that the reaction rate of irradiation-induced U-Mo-Al inter-diffusion, an important microstructural change impacting the performance of this type of fuel, is temperature and fission-rate dependent. In order to simulate the U-Mo/Al inter-diffusion layer (IL) growth behavior in full-size dispersion fuel plates, the existing IL growth correlation was modified with a temperaturedependent multiplication factor that transits around a threshold fission rate. In-pile irradiation data from four tests in the BR2 reactors, including FUTURE, E-FUTURE, SELEMIUM, and SELEMIUM-1a, were utilized to determine and validate the updated IL growth correlation. Irradiation behavior of the plates was simulated with the DART-2D computational code. The general agreement between the calculated and measured fuel meat swelling and constituent volume fractions as a function of fission density demonstrated the plausibility of the updated IL growth correlation. The simulation results also suggested the temperature dependence of the IL growth rate, similar to the temperature dependence of the intermixing rate in ion-irradiated bi-layer systems.

  8. Study of the aqueous corrosion mechanisms and kinetics of the AlFeNi aluminium based alloy used for the fuel cladding in the Jules Horowitz research reactor

    International Nuclear Information System (INIS)

    Wintergerst, M.

    2009-05-01

    For the Jules Horowitz new material-testing reactor (JHR), an aluminium base alloy, called AlFeNi, will be used for the cladding of the fuel plates. This alloy (Al - 1% Fe - 1% Ni - 1 % Mg), which is already used as fuel cladding, was developed for its good corrosion resistance in water at high temperatures. However, few studies dealing with the alteration process in water and the relationships with irradiation effects have been performed on this alloy. The conception of the JHR fuel requires a better knowledge of the corrosion mechanisms. Corrosion tests were performed in autoclaves at 70 C, 165 C and 250 C on AlFeNi plates representative of the fuel cladding. Several techniques were used to characterize the corrosion scale: SEM, TEM, EPMA, XRD, Raman spectroscopy. Our observations show that the corrosion scale is made of two main layers: a dense amorphous scale close to the metal and a porous crystalline scale in contact with the water. More than the morphology, the chemical compositions of both layers are different. This duplex structure results from a mixed growth mechanism: an anionic growth to develop the inner oxide and a cationic diffusion followed by a dissolution-precipitation process to form the outer one. Dynamic experiments at 70 C and corrosion kinetics measurements have demonstrated that the oxide growth process is controlled by a diffusion step associated to a dissolution/precipitation process. A corrosion mechanism of the AlFeNi alloy in aqueous media has been proposed. Then post-irradiation exams performed on irradiated fuel plates were used to investigate the effects of the irradiation on the corrosion behaviour in the reactor core. (author)

  9. A cellular automaton method to simulate the microstructure and evolution of low-enriched uranium (LEU) U–Mo/Al dispersion type fuel plates

    Energy Technology Data Exchange (ETDEWEB)

    Drera, Saleem S., E-mail: saleem.drera@gmail.com [Mechanical Engineering, Colorado School of Mines, Golden, CO 80401 (United States); Hofman, Gerard L. [Argonne National Laboratory, Chicago, IL 60439 (United States); Kee, Robert J. [Mechanical Engineering, Colorado School of Mines, Golden, CO 80401 (United States); King, Jeffrey C. [Metallurgical and Materials Engineering, Colorado School of Mines, Golden, CO 80401 (United States)

    2014-10-15

    Highlights: • This article presents a cellular automata (CA) algorithm to synthesize the growth of intermetallic interaction layers in U–Mo/Al dispersion fuel. • The method utilizes a 3D representation of the fuel, which is discretized into separate voxels that can change identy based on derived CA rules. • The CA model is compared to ILT measurements for RERTR experimental data. • The primary objective of the model is to synthesize three-dimensional microstructures that can be used in subsequent thermal and mechanical modeling. • The CA model can be used for predictive analysis. For example, it can be used to study the dependence of temperature on interaction layer growth. - Abstract: Low-enriched uranium (LEU) fuel plates for high power materials test reactors (MTR) are composed of nominally spherical uranium–molybdenum (U–Mo) particles within an aluminum matrix. Fresh U–Mo particles typically range between 10 and 100 μm in diameter, with particle volume fractions up to 50%. As the fuel ages, reaction–diffusion processes cause the formation and growth of interaction layers that surround the fuel particles. The growth rate depends upon the temperature and radiation environment. The cellular automaton algorithm described in this paper can synthesize realistic random fuel-particle structures and simulate the growth of the intermetallic interaction layers. Examples in the present paper pack approximately 1000 particles into three-dimensional rectangular fuel structures that are approximately 1 mm on each side. The computational approach is designed to yield synthetic microstructures consistent with images from actual fuel plates and is validated by comparison with empirical data on actual fuel plates.

  10. Contribution to the study of gaseous Carburization of Uranium; Contribucion al estudio de la Carburacion gaesosa del uranio

    Energy Technology Data Exchange (ETDEWEB)

    Esteban Hernandez, J A; Jimenez Moreno, J M; Villota Ruiz, P de

    1966-07-01

    Thermal decomposition of uranium hydride powder obtained by hydrogenation of uranium turnings is studied on the first part of this paper. Carburization of the uranium hydride or metallic uranium powder with methane is studied in the second part. A method of uranium monocarbide fabrication under static atmosphere is described. On this method hydrogen is removed by means of an uranium getter. (Author) 6 refs.

  11. Nuevas contribuciones en la fisioterapia del linfedema de miembro superior secundario al tratamiento del cáncer de mama

    OpenAIRE

    Canet Pérez, Cristina; Santandreu Mañó, Trinidad; Nácher Nebot, Rosa

    2011-01-01

    Resumen del póster presentado en las II Jornadas de Fisioterapia en Lesiones del Sistema Músculo-esquelético: miembro superior. Escuela Universitaria de Fisioterapia Universitat de València 28 y 29 abril de 2011 Introducción. El linfedema supone un importante problema en mujeres tratadas de cáncer de mama. Distintas revisiones han puesto...

  12. First commercial fuel cells in emergency power supplies; Erste kommerzielle Brennstoffzellen im Notstrombereich. Praxistest als USV fuer eine Mobilfunkbasisstation

    Energy Technology Data Exchange (ETDEWEB)

    Trachte, U.

    2008-07-01

    This article takes a look at the testing of a fuel-cell-based uninterruptible power supply for a cell-phone base station. The working principles of various types of fuel cell are examined and their areas of application are discussed. The use of polymer-electrolyte-membrane (PEM) fuel cells as a back-up power supply for a cell-phone base station was examined by the University of Applied Sciences in Lucerne, Switzerland. Several designs and models of fuel cells were examined. The installation of the cell-phone station is described and experience gained from the use of fuel cells in practice is presented and discussed.

  13. Estudios etnográficos sobre el desarrollo infantil en comunidades indígenas de América Latina: contribuciones, omisiones y desafíos

    Directory of Open Access Journals (Sweden)

    Carolina Remorini

    2013-09-01

    Full Text Available DOI: http://dx.doi.org/10.5007/2175-795X.2013v31n3p811 En las últimas décadas, ha habido un progreso sustancial en el estudio del Desarrollo Infantil Temprano (DIT desde perspectivas interdisciplinarias e transculturales. Varios autores reconocen la contribución de la antropología al debate sobre la primera infancia, en diálogo con la psicología, las neurociencias, la educación y la medicina. Estos estudios subrayan la importancia de los contextos ecológicos en lo que se refi ere al crecimiento físico, las trayectorias de desarrollo y los efectos sobre la salud a mediano y largo plazo. La Antropología hace hincapié en la noción de que el desarrollo de los niños depende de las interacciones que éstos entablan con su entorno inmediato y las actividades en las que participan. La importancia dada al ambiente desde una perspectiva ecológica reconoce el valor heurístico de los estudios etnográfi cos. En este trabajo caracterizamos, algunos ejes y modos de abordaje que se destacan en la producción etnográfi ca sobre infancia y desarrollo infantil en Latinoamérica, especialmente, sobre comunidades indígenas. En segundo lugar, analizamos y discutimos las posibilidades de interface entre la etnografía y las disciplinas que tradicionalmente se han ocupado del desarrollo infantil y refl exionamos sobre sus contribuciones en términos metodológicos a la comprensión de un proceso de carácter multidimensional, evitando los reduccionismos propios de cada mirada disciplinar. En relación a ello, discutimos los desafíos que la etnografía presenta en el contexto de la investigación inter y transdisciplinaria del DIT. Para concluir, reflexionamos sobre la necesidad de recuperar el DIT como objeto de estudio etnográfi co, como lo fue en los inicios de la disciplina.

  14. MARTINS: A foam/film flow model for molten material relocation in HWRs with U-Al-fueled multi-tube assemblies

    International Nuclear Information System (INIS)

    Kalimullah.

    1994-01-01

    Some special purpose heavy-water reactors (EM) are made of assemblies consisting of a number of coaxial aluminum-clad U-Al alloy fuel tubes and an outer Al sleeve surrounding the fuel tubes. The heavy water coolant flows in the annular gaps between the circular tubes. Analysis of severe accidents in such reactors requires a model for predicting the behavior of the fuel tubes as they melt and disrupt. This paper describes a detailed, mechanistic model for fuel tube heatup, melting, freezing, and molten material relocation, called MARTINS (Melting and Relocation of Tubes in Nuclear subassembly). The paper presents the modeling of the phenomena in MARTINS, and an application of the model to analysis of a reactivity insertion accident. Some models are being developed to compute gradual downward relocation of molten material at decay-heat power levels via candling along intact tubes, neglecting coolant vapor hydrodynamic forces on molten material. These models are inadequate for high power accident sequences involving significant hydrodynamic forces. These forces are included in MARTINS

  15. A Prediction Study on Oxidation of Aluminum Alloy Cladding of U{sub 3}Si{sub 2}-Al Fuel Plate

    Energy Technology Data Exchange (ETDEWEB)

    Tahk, Y.W.; Lee, B.H.; Oh, J.Y.; Park, J.H.; Yim, J.S. [Research Reactor Design and Engineering Div., Korea Atomic Energy Research Institute, 1045 Daedeokdaero, Yuseong, Daejeon 305-353 (Korea, Republic of)

    2011-07-01

    U{sub 3}Si{sub 2}-Al dispersion fuel with aluminum alloy cladding will be used for the Jordan Research and Training Reactor (JRTR). Aluminum alloy cladding undergoes corrosion at slow rates under operational status. This causes thinning of the cladding walls and impairs heat transfer to the coolant. Predictions of the aluminum oxide thickness of the fuel cladding and the maximum temperature difference across the oxide film are needed for reliability evaluation based on the design criteria and limits which prohibit spallation of oxide film. In this work, several oxide thickness prediction models were compared with the measured data of in-pile test results from RERTR program. Moreover, specific parametric studies and a preliminary prediction of the aluminum alloy oxidation using the latest model were performed for JRTR fuel. According to the current JRTR fuel management scheme and operation strategy for 5 MW power, fresh fuel is discharged after 900 effective full power days (EFPD), which is too long a span to predict oxidation properly without an elaborate model. The latest model developed by Kim et al. is in good agreement with the recent in-pile test data as well as with the out-of-pile test data available in the literature, and is one of the best predictors for the oxidation of aluminum alloy cladding in various operating condition. Accordingly, this model was chosen for estimating the oxide film thickness. Through the preliminarily evaluation, water pH level is to be controlled lower than 6.2 for the conservativeness in the case of including the effect of anticipated operational occurrences and the spent fuel residence time in the storage rack after discharging. (author)

  16. High temperature steam oxidation of Al3Ti-based alloys for the oxidation-resistant surface layer on Zr fuel claddings

    International Nuclear Information System (INIS)

    Park, Jeong-Yong; Kim, Il-Hyun; Jung, Yang-Il; Kim, Hyun-Gil; Park, Dong-Jun; Choi, Byung-Kwon

    2013-01-01

    We investigated the feasibility to apply Al 3 Ti-based alloys as the surface layer for improving the oxidation resistance of Zr fuel claddings under accident conditions. Two types of Al 3 Ti-based alloys with the compositions of Al–25Ti–10Cr and Al–21Ti–23Cr in atomic percent were prepared by arc-melting followed by homogenization annealing at 1423 K for 48 h. Al–25Ti–10Cr alloy showed an L1 2 quasi-single phase microstructure with a lot of needle-shaped minor phase and pores. Al–21Ti–23Cr alloy consisted of an L1 2 matrix and Cr 2 Al as the second phase. Al 3 Ti-based alloys showed an extremely low oxidation rate in a 1473 K steam for up to 7200 s when compared to Zircaloy-4. Both alloys exhibited almost the same oxidation rate in the early stage of oxidation, but Al–25Ti–10Cr showed a little lower oxidation rate after 4000 s than Al–21Ti–23Cr. The difference in the oxidation rate between two types of Al 3 Ti-based alloys was too marginal to distinguish the oxidation behavior of each alloy. The resultant oxide exhibited almost the same characteristics in both alloys even though the microstructure was explicitly distinguished from each other. The crystal structure of the oxide formed up to 2000 s was identified as Al 2 O 3 in both alloys. The oxide morphology consisted of columnar grains whose length was almost identical to the average oxide thickness. On the basis of the results obtained, it is considered that Al 3 Ti-based alloy is one of the promising candidates for the oxidation-resistant surface layer on Zr fuel claddings

  17. La relación entre creatividad y expertise: contribuciones teóricas y empíricas

    Directory of Open Access Journals (Sweden)

    Afonso C. T. Galvao

    2009-06-01

    Full Text Available La creatividad y el expertise son temas que están recibiendo mayor atención de los inves­tigadores en distintos campos del conocimiento. Atributos personales asociados a la alta producción creativa, factores que favorecen el desarrollo, la expresión de la creatividad y el expertise, así como los procesos implicados en el desarrollo de la alta competencia y la creatividad, son temas que han sido objeto de numerosos estudios. El presente estudio pre­senta contribuciones teóricas y estudios empíricos acerca de la creatividad y el expertise. Se describen los elementos comunes para el desarrollo de la creatividad y el expertise, así como las características de los ambientes educativos que los promueven, los modelos teóricos y estudios empíricos.

  18. Interaction between uranium oxide alloyed with Al2O3·SiO2 and pyrocarbon coating during irradiation of micro fuel elements

    International Nuclear Information System (INIS)

    Chernikov, A.S.; Khromov, Y.F.; Svistunov, D.E.; Chuiko, E.E.

    1989-01-01

    The thermodynamics of the interaction between uranium oxide and carbon was previously studied in the presence of Al 2 O 3 ·SiO 2 , SiC, and UC 1.86 ; in this case, the quantity of the reacting substances does not have any effect on the attainment of the equilibrium state. Based on the obtained results, it is interesting to study the characteristic features of the interaction between the alloyed UO x cores (kernels) with the PyC-coating under the conditions involving irradiation of the micro fuel elements with thermal neutrons and the formation of solid fission products. The data concerning the characteristics of a micro fuel element (the weight of the core, its composition, etc.) are useful for carrying out a quantitative evaluation of the additives required for fixing the alkali-earth fission products by obtaining stable compounds of aluminosilicates with Ba, Sr, Rb, and Cs at different levels of depletion (burnup) of the oxide fuel. An analysis of the interaction processes in such a complex system as the irradiated alloyed uranium oxide fuel located in a micro fuel element is carried out by comparing the chemical potential of oxygen (RT ln P O 2 ) for the competing constituents of the system

  19. Status report on the irradiation testing and post-irradiation examination of low-enriched U3O8-Al and UAlsub(x)-Al fuel element by the Netherlands Energy Research Foundation (ECN)

    International Nuclear Information System (INIS)

    Pruimboom, H.; Lijbrink, E.; Otterdijk, K. von; Swanenburg de Veye, R.J.

    1984-01-01

    Within the framework of the RERTR-programme four low-enriched (20%) MTR-type fuel elements have been irradiated in the High Flux Reactor at Petten (The Netherlands) and are presently subjected to postirradiation examination. Two of the elements contain UAlsub(x)-Al and two contain U 3 O 8 -Al fuel. The test irradiation has been completed up to the target burn-up values of 50% and 75% respectively. An extensive surveillance programme carried out during the test period has confirmed the excellent in-reactor behaviour of both types. Post-irradiation examination of the 50% burn-up test elements, comprising of dimensional measurements, burn-up determination, fuel metallography and blister testing, has sofar confirmed the irradiation experiences. Good agreement between calculated and measured power and burn-up characteristics has been found. A survey of the test element characteristics, their irradiation history, the irradiation tests and the preliminary PIE results is given in the paper. (author)

  20. Pembuatan Fuel dari Liquid Hasil Pirolisis Plastik Polipropilen Melalui Proses Reforming Dengan Katalis NiO/γ-Al2O3

    Directory of Open Access Journals (Sweden)

    Mahendra Fajri Nugraha

    2013-09-01

    Full Text Available Estimasi jumlah timbulan sampah di Indonesia pada tahun 2008 mencapai 38,5 juta ton/tahun. Melihat dari sifat penyusun plastik yang tersusun dari komponen hidrokarbon minyak bumi, maka limbah plastik sangat berpotensi untuk dikonversi menjadi BBM. Tujuan penelitian ini Mempelajari proses konversi limbah plastik khususnya jenis polipropilen (PP menjadi fuel serta pengaruh berbagai macam komposisi katalis NiO/γ-Al2O3, temperatur, laju alir reaktan pada reactor reforming terhadap kualitas fuel (yield aromatis yang dihasilkan. Pada penelitian ini bahan baku yang digunakan merupakan plastik jenis Polipropilen (PP. Pada penelitian ini minyak yang telah dihasilkan pada proses pirolisis selanjutnya akan di reforming. Pada penelitian ini digunakan logam NiO dengan penyangga γ-Al2O3 (NiO/γ-Al2O3 sebagai katalis untuk proses reforming minyak hasil pirolisis plastik polipropilen. Variabel penelitian meliputi Loading Ni (% massa : 6; 10; 14, Laju alir (ml/jam : 2I7; 500; 690, Suhu reaksi (oC : 400; 450; 500. Berdasarkan hasil penelitian dan analisa diketahui bahwa % yield aromatis terbesar pada proses reforming minyak hasil pirolisis plastik polipropilen dihasilkan dengan kondisi operasi 14 % loading Ni pada katalis, temperatur reforming 500oC serta laju reaktan sebesar 217 mL/jam. Dengan kata lain dapat disimpulkan bahwa pada penelitian ini, hasil terbaik didapat pada variabel flowlaju terendah dan variabel suhu tertinggi. Kondisi operasi efektif dalam pembuatan fuel pada proses reforming diperoleh saat loading Ni pada katalis NiO/γ-Al2O3 14 %, temperatur reforming 400oC serta laju reaktan 500 mL/jam.

  1. Study of the Ni-NiAl{sub 2}O{sub 4}-YSZ cermet for its possible application as an anode in solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Reyes-Rojas, A [Centro de Investigacion en Materiales Avanzados SC, Miguel de Cervantes 120, Complejo Industrial Chihuahua, Chihuahua (Mexico); Universidad Autonoma del Estado de Mexico, Facultad de Quimica, Toluca (Mexico); Esparza-Ponce, H E [Centro de Investigacion en Materiales Avanzados SC, Miguel de Cervantes 120, Complejo Industrial Chihuahua, Chihuahua (Mexico); Reyes-Gasga, J [Universidad Nacional Autonoma de Mexico, Instituto de Fisica, Mexico DF (Mexico)

    2006-05-17

    Nanocrystalline Ni-NiAl{sub 2}O{sub 4}-YSZ cermet with a possible application as anode in solid oxide fuel cells (SOFCs) has been developed. The powders were prepared by using an alternative solid-state method that includes the use of nickel acetylacetonate as an inorganic precursor to obtain a highly porous material after sintering at 1400 {sup o}C and oxide reduction (NiO -Al{sub 2}O{sub 3}-YSZ {yields} Ni-NiAl{sub 2}O{sub 4}-YSZ) at 800 {sup o}C for 8 h in a tubular reactor furnace using 10% H{sub 2}/N{sub 2}. Eight samples with 45% Ni and 55% Al{sub 2}O{sub 3}-YSZ in concentrations of Al{sub 2}O{sub 3} oxides from 10 to 80 wt% of were mixed to obtain the cermets. The obtained material was compressed using unidirectional axial pressing and calcinations from room temperature to 800 {sup o}C. Good results were registered using a heating rate of 1 {sup o}C min{sup -1} and a special ramp to avoid anode cracking. Thermal expansion, electrical conductivity, and structural characterization by thermo-mechanical analyser (TMA) techniques/methods, the four-point probe method for conductivity, scanning electron microscopy (SEM), x-ray energy dispersive spectroscopy (EDS), x-ray diffraction (XRD), and the Rietveld method were carried out. Cermets in the range 5.5 to 11% Al{sub 2}O{sub 3} present a crystal size around 200 nm. An inversion degree (I) in the NiAl{sub 2}O{sub 4} spinel structure of the cermets Ni-NiAl{sub 2}O{sub 4}-YSZ was found after the sintering and reduction processes. Good electrical conductivity and thermal expansion coefficient were obtained for the cermet with 12 wt% of spinel structure formation.

  2. A modelling study of the inter-diffusion layer formation in U-Mo/Al dispersion fuel plates at high power

    Science.gov (United States)

    Ye, B.; Hofman, G. L.; Leenaers, A.; Bergeron, A.; Kuzminov, V.; Van den Berghe, S.; Kim, Y. S.; Wallin, H.

    2018-02-01

    Post irradiation examinations of full-size U-Mo/Al dispersion fuel plates fabricated with ZrN- or Si- coated U-Mo particles revealed that the reaction rate of irradiation-induced U-Mo-Al inter-diffusion, an important microstructural change impacting the performance of this type of fuel, transited at a threshold temperature/fission rate. The existing inter-diffusion layer (IL) growth correlation, which does not describe the transition behavior of IL growth, was modified by applying a temperature-dependent multiplication factor that transits around a threshold fission rate. In-pile irradiation data from four tests in the BR2 reactors, including FUTURE, E-FUTURE, SELEMIUM, and SELEMIUM-1a, were utilized to determine and validate the updated IL growth correlation. Irradiation behavior of the plates was simulated with the DART-2D computational code. The general agreement between the calculated and measured fuel meat swelling and constituent volume fractions as a function of fission density demonstrated the plausibility of the updated IL growth correlation. The simulation results also suggested the temperature dependence of the IL growth rate, similar to the temperature dependence of the inter-mixing rate in ion-irradiated bi-layer systems.

  3. Development of a treatment technology for diluting highly enriched AL-based DOE spent nuclear fuel: principles and practices

    International Nuclear Information System (INIS)

    Adams, T.M.; Duncan, A.J.; Peacock, H.B.; Fisher, D.L.

    2001-01-01

    The Savannah River Site is the U.S. Department of Energy's preferred site for return and treatment of all aluminum-base, spent, research and test reactor fuel assemblies. There are over 20,000 spent fuel assemblies now stored in different countries around the world, and by 2035 many will be returned to SRS for treatment and interim storage. Interim storage canisters at SRS will be sent to a Mined Geologic Repository for long-term geologic storage. Laboratory and plant layout of a full-scale process for irradiated fuel has been completed. Tests of the off gas absorption system have been initiated using both surrogate and irradiated RERTR mini fuel plates. An pilot-scale L-Area Experimental Facility (LEF) is planned to validate induction furnace operations, remote handling, and the off gas system for trapping volatile elements under plant operating conditions. (authors)

  4. Fabrication of high-uranium-loaded U/sub 3/O/sub 8/-Al developmental fuel plates

    Energy Technology Data Exchange (ETDEWEB)

    Copeland, G.L.; Martin, M.M.

    1980-12-01

    A common plate-type fuel for research and test reactors is U/sub 3/O/sub 8/ dispersed in aluminum and clad with an aluminum alloy. There is an impetus to reduce the /sup 235/U enrichment from above 90% to below 20% for these fuels to lessen the risk of diversion of the uranium for nonpeaceful uses. Thus, the uranium content of the fuel plates has to be increased to maintain the performance of the reactors. This paper describes work at ORNL to determine the maximal uranium loading for these fuels that can be fabricated with commercially proven materials and techniques and that can be expected to perform satisfactorily in service.

  5. Furfural and other furane-derivates as diesel fuel additives. Furfural und andere Furanderivate als Zusatz zum Dieselkraftstoff

    Energy Technology Data Exchange (ETDEWEB)

    Nemling, O.

    1982-01-01

    Alternative energies such as fuel additives or fuel-substitutes are on their way upwards as they may help to reduce the dependency on crude and crude-based fuels. A number of solutions has already been indicated for carburettor engines whereas a lot more of research and development is needed to find a safe alternative to diesel fuels. Possibilities of using furfural, furfuralcohol and furan-2-carbonic acid-methylester as additives to diesel or as a substitute were investigated. A survey on the characteristic properties of these substances is given, then several tests are set up in order to describe the properties of diesel additive mixtures at low temperatures. Based on these tests two mixtures are proposed both with a furfural/butanole mixture. Furfural is suitable as diesel additive, a solubilizer is needed though.

  6. Facile and rapid auto-combustion synthesis of nano-porous γ-Al2O3 by application of hexamethylenetetramine in fuel composition

    Science.gov (United States)

    Salem, Shiva; Salem, Amin; Parni, Mohammad Hosein; Jafarizad, Abbas

    2018-06-01

    In this article, urea, glycine and hexamethylenetetramine were blended in accordance with the mixture design algorithm to prepare γ-Al2O3 by auto-combustion technique. Aluminum nitrate was then mixed with the stoichiometric contents of prepared fuel solutions to obtain gel systems. The gels exhibited a typical self-propagating combustion behavior at low temperature, directly resulting amorphous materials. The precursors were calcined at various temperatures ranging from 700 to 900 °C. The treated powders were evaluated by determining the methylene blue (MB) adsorption efficiency. The production condition to obtain γ-Al2O3 with maximum surface area depends on fuel composition and calcination temperature. The alumina powder fabricated by this procedure was uniformly distributed and contains nano-sized secondary particles with diameter about 10-30 nm in which the average pore size is 3.2 nm induced large surface area, 240 m2g-1. The employment of hexamethylenetetramine provides a potential for synthesis of γ-Al2O3 at lower temperature, 700 °C, with maximum MB removal efficiency.

  7. TiO2 and Al2O3 promoted Pt/C nanocomposites as low temperature fuel cell catalysts for electro oxidation of methanol in acidic media

    International Nuclear Information System (INIS)

    Naeem, Rabia; Ahmed, Riaz; Ansari, Muhammad Shahid

    2014-01-01

    Carbon corrosion and platinum dissolution are the two major catalyst layer degradation problems in polymer electrolyte membrane fuel cells (PEMFC). Ceramic addition can reduce the corrosion of carbon and increase the stability of catalysts. Pt/TiO 2 , Pt/TiO 2 -C, Pt/Al 2 O 3 and Pt/Al 2 O 3 -C catalysts were synthesized and characterized. Electrochemical surface area of Pt/TiO 2 -C and Pt/Al 2 O 3 -C nanocomposite catalysts was much higher than the Pt/TiO 2 and Pt/Al 2 O 3 catalysts. Peak current, specific activity and mass activity of the catalysts was also determined by cyclic voltammetry and were much higher for the carbon nanocomposites. Exchange current densities were determined from Tafel plots. Heterogeneous rates of reaction of electro oxidation of methanol were determined for all the catalysts and were substantially higher for titania catalysts as compared to alumina added catalysts. Mass activity of Pt/TiO 2 -C was much higher than mass activity of Pt/Al 2 O 3 -C. Stability studies showed that addition of ceramics have increased the catalytic activity and durability of the catalysts considerably

  8. Partial oxidation of jet fuels over Rh/Al_2O_3. Design and reaction kinetics of sulfur-containing surrogates

    International Nuclear Information System (INIS)

    Baer, Julian Nicolaas

    2016-01-01

    The conversion of logistic fuels via catalytic partial oxidation (CPOX) on Rh/Al_2O_3 at short contact times is an efficient method for generating hydrogen-rich synthesis gas. Depending on the inlet conditions, fuel, and catalyst, high syngas yields, low by-product formation, and rates of high fuel conversion can be achieved. CPOX is relevant for mobile hydrogen generation, e.g., on board of airplanes in order to increase the fuel efficiency via fuel cell-based auxiliary power units. Jet fuels contain hundreds of different hydrocarbons and a significant amount of sulfur. The hydrocarbon composition and sulfur content of a jet fuel vary depending on distributor, origin, and refinement of the crude oil. Little is known about the influence of the various compounds on the synthesis-gas yield and the impact of sulfur on the product yield. In this work, the influence of three main chemical compounds of a jet fuel (aromatics, alkanes, and sulfur compounds) on syngas selectivity, the catalyst deactivation process, and reaction sequence is unraveled. As representative components of alkanes and aromatics, n-dodecane and 1,2,4-trimethylbenzene were chosen for ex-situ and in-situ investigations on the CPOX over Rh/Al_2O_3, respectively. Additionally, for a fixed paraffin-to-aromatics ratio, benzothiophene or dibenzothiophene were added as a sulfur component in three different concentrations. The knowledge gained about the catalytic partial oxidation of jet fuels and their surrogates is used to identify requirements for jet fuels in mobile applications based on CPOX and to optimize the overall system efficiency. The results show an influence of the surrogate composition on syngas selectivity. The tendency for syngas formation increases with higher paraffin contents. A growing tendency for by-product formation can be observed with increasing aromatics contents in the fuel. The impact of sulfur on the reaction system shows an immediate change in the product distribution. An

  9. Partial oxidation of jet fuels over Rh/Al{sub 2}O{sub 3}. Design and reaction kinetics of sulfur-containing surrogates

    Energy Technology Data Exchange (ETDEWEB)

    Baer, Julian Nicolaas

    2016-07-01

    The conversion of logistic fuels via catalytic partial oxidation (CPOX) on Rh/Al{sub 2}O{sub 3} at short contact times is an efficient method for generating hydrogen-rich synthesis gas. Depending on the inlet conditions, fuel, and catalyst, high syngas yields, low by-product formation, and rates of high fuel conversion can be achieved. CPOX is relevant for mobile hydrogen generation, e.g., on board of airplanes in order to increase the fuel efficiency via fuel cell-based auxiliary power units. Jet fuels contain hundreds of different hydrocarbons and a significant amount of sulfur. The hydrocarbon composition and sulfur content of a jet fuel vary depending on distributor, origin, and refinement of the crude oil. Little is known about the influence of the various compounds on the synthesis-gas yield and the impact of sulfur on the product yield. In this work, the influence of three main chemical compounds of a jet fuel (aromatics, alkanes, and sulfur compounds) on syngas selectivity, the catalyst deactivation process, and reaction sequence is unraveled. As representative components of alkanes and aromatics, n-dodecane and 1,2,4-trimethylbenzene were chosen for ex-situ and in-situ investigations on the CPOX over Rh/Al{sub 2}O{sub 3}, respectively. Additionally, for a fixed paraffin-to-aromatics ratio, benzothiophene or dibenzothiophene were added as a sulfur component in three different concentrations. The knowledge gained about the catalytic partial oxidation of jet fuels and their surrogates is used to identify requirements for jet fuels in mobile applications based on CPOX and to optimize the overall system efficiency. The results show an influence of the surrogate composition on syngas selectivity. The tendency for syngas formation increases with higher paraffin contents. A growing tendency for by-product formation can be observed with increasing aromatics contents in the fuel. The impact of sulfur on the reaction system shows an immediate change in the product

  10. Corrosion behavior of Fe-Si metallic coatings added with NiCrAlY in an environment of fuel oil ashes at 700 C

    Energy Technology Data Exchange (ETDEWEB)

    Salinas-Bravo, V.M.; Porcayo-Calderon, J.; Romero-Castanon, T. [Instituto de Investigaciones Electricas, Gerencia de Procesos Termicos., Av. Reforma 113, C.P. 62490 Col. Palmira. Temixco. Morelos (Mexico); Dominguez-Patino, G.; Gonzalez-Rodriguez, J.G. [U.A.E.M. Centro de Investigaciones en Ingenieria y Ciencias Aplicadas., Av. Universidad 1001, C.P. 62210, Col. Chamilpa. Cuernavaca, Morelos (Mexico)

    2005-07-01

    Electrochemical potentiodynamic polarization curves and immersion tests for 300 h at 700 C in a furnace have been used to evaluate the corrosion resistance of Fe-Si metallic coatings added with up to 50 wt.% of NiCrAIY. The corrosive environment was fuel oil ashes from a steam generator. The composition of fuel oil ashes includes high content of vanadium, sodium and sulfur. The results obtained show that only the addition of 20 wt.% NiCrAlY to the Fe-Si coating improves its corrosion resistance. The behavior of all tested coatings is explained by the results obtained from the analysis of every coating using electron microscopy and energy dispersive X-ray analysis. (Abstract Copyright [2005], Wiley Periodicals, Inc.)

  11. Properties and efficiency of a Pt/Al2O3 catalyst applied in a solid fuel thermo-accumulating furnace

    Directory of Open Access Journals (Sweden)

    SRDJAN BELOSEVIC

    2007-08-01

    Full Text Available A prototype of a solid fuel thermo-accumulating furnace has been developed. In order to achieve a higher combustion efficiency, a Pt/Al2O3 catalyst in the form of 3 ± 0.3 mm spheres was applied, which enabled further combustion of flue gases within the furnace. Experimental investigation of the influence of the catalyst on the conversion of CO has been done for different operation regimes and positions of the catalyst. Paper presents selected results regarding CO emission during wood and coal combustion. Investigations suggest a considerable effect of the catalyst and a strong influence of the catalyst position to CO emission reduction. The microstructure of the catalyst beads, characterized by selective chemisorption of CO, has shown the decrease of the number of Pt sites as a consequence of blockage by coke deposits formed during the combustion of solid fuel.

  12. The use of blunted Maya crude as alternating fuel to fuel oil; Uso de crudo Maya despuntado como combustiononble alterno al combustoleo

    Energy Technology Data Exchange (ETDEWEB)

    Salinas Bravo, Victor M.; Diego Marin, Antonio; Porcayo C; Jesus [Instituto de Investigaciones Electricas, Temixco, Morelos (Mexico)

    2001-07-01

    The Mexican fuel oil is characterized by its high viscosity and elevated contents of sulfur and vanadium. This particularity determines a problematic characteristic in the steam generators that use this fuel. Our country produces three types of crude petroleum: Olmeca, Istmo and Maya. The difference between these crudes remains in its density and the sulfur content. The Olmeca crude and the Istmo are classified as super-light and light, respectively; whereas the Maya crude is classified as a heavy crude, with a density of 1.0 to 0.92 g/cm and a minimum sulfur content of 3.3 %. For this reason the processing of the Maya crude is seen as an alternative. A table with the physicochemical analysis and properties of a fuel oil and the blunted Maya crude is given, and another one with the quantitative chemical analysis of some metals in fuel oil and in the blunted Maya crude. The stability tests of the fuel are studied giving a comparison of the effect of the aging time on the viscosity of a fuel oil and of the blunted Maya crude at 60 Celsius degrees. As well as a graph of thermograms obtained of a blunted Maya crude sample and of a typical fuel oil. Finally the corrosion tests are described that allow to know in real time the degradation process by corrosion of the materials. [Spanish] El combustoleo mexicano se caracteriza por su alta viscosidad y elevados contenidos de azufre y vanadio. Esta particularidad determina una problematica caracteristica en los generadores de vapor que utilizan este combustible. Nuestro pais produce tres tipos de petroleo crudo: Olmeca, Istmo y Maya. La diferencia entre estos crudos estriba en su densidad y el contenido de azufre. El crudo Olmeca y el Istmo estan clasificados como superligero y ligero, respectivamente; mientras que el crudo Maya esta clasificado como un crudo pesado, con una densidad de 1.0 a 0.92 g/cm y un contenido minimo de azufre de 3.3 %.Con el proposito se busca la alternativa de procesar el crudo Maya. Se da una tabla

  13. Part II: Oxidative Thermal Aging of Pd/Al2O3 and Pd/CexOy-ZrO2 in Automotive Three Way Catalysts: The Effects of Fuel Shutoff and Attempted Fuel Rich Regeneration

    Directory of Open Access Journals (Sweden)

    Qinghe Zheng

    2015-10-01

    Full Text Available The Pd component in the automotive three way catalyst (TWC experiences deactivation during fuel shutoff, a process employed by automobile companies for enhancing fuel economy when the vehicle is coasting downhill. The process exposes the TWC to a severe oxidative aging environment with the flow of hot (800 °C–1050 °C air. Simulated fuel shutoff aging at 1050 °C leads to Pd metal sintering, the main cause of irreversible deactivation of 3% Pd/Al2O3 and 3% Pd/CexOy-ZrO2 (CZO as model catalysts. The effect on the Rh component was presented in our companion paper Part I. Moderate support sintering and Pd-CexOy interactions were also experienced upon aging, but had a minimal effect on the catalyst activity losses. Cooling in air, following aging, was not able to reverse the metallic Pd sintering by re-dispersing to PdO. Unlike the aged Rh-TWCs (Part I, reduction via in situ steam reforming (SR of exhaust HCs was not effective in reversing the deactivation of aged Pd/Al2O3, but did show a slight recovery of the Pd activity when CZO was the carrier. The Pd+/Pd0 and Ce3+/Ce4+ couples in Pd/CZO are reported to promote the catalytic SR by improving the redox efficiency during the regeneration, while no such promoting effect was observed for Pd/Al2O3. A suggestion is made for improving the catalyst performance.

  14. Manufacturing of FeCrAl/Zr Dual Layer tube for its application to LWR Fuel cladding

    Energy Technology Data Exchange (ETDEWEB)

    Park, Dong Jun; Lim, Do Wan; Jung, Yang Il; Kim, Hyun Gil; Park, Jeong Yong [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2013-10-15

    Many advanced materials such as MAX phases, Mo, SiC, and Fe-based alloys are being considered a possible candidate to substitute the Zr-based alloy cladding has been used in light water reactors. Among the proposed candidate materials, Fe-based alloy is one of the most promising candidates owing to its excellent formability, very good high strength, and corrosion resistance at high temperature. However, neutron cross section of FeCrAl alloy is much higher than that of existing Zr-based alloys. In this study, FeCrAl/Zr dual layer tube was manufactured by using a hot isostatic pressing (HIP) method. The thickness of outer FeCrAl layer was varied from 50 to 250 μm but all the FeCrAl/Zr dual layer tube samples maintained its total thickness of 570 μm. For a detailed microstructural characterization of FeCrAl/Zr dual layer, polarized optical microscopy and scanning electron microscopy (SEM) study carried out and its mechanical property was measured by ring compression test. FeCrAl/Zr dual layer tube sample was successfully manufactured with good adhesion between both layers. Inter layer showing gradual element variation was observed at interface. Result obtained from simulated LOCA test indicates that FeCrAl/Zr dual layer tube may maintain its integrity during LOCA and its accident tolerance had greatly improved compared to that of Zr-based alloy.

  15. Effects of irradiation on the microstructure of U-7Mo dispersion fuel with Al-2Si matrix

    Science.gov (United States)

    Keiser, Dennis D.; Jue, Jan-Fong; Robinson, Adam B.; Medvedev, Pavel; Gan, Jian; Miller, Brandon D.; Wachs, Daniel M.; Moore, Glenn A.; Clark, Curtis R.; Meyer, Mitchell K.; Ross Finlay, M.

    2012-06-01

    The Reduced Enrichment for Research and Test Reactor (RERTR) program is developing low-enriched uranium U-Mo dispersion fuels for application in research and test reactors around the world. As part of this development, fuel plates have been irradiated in the Advanced Test Reactor and then characterized using optical metallography (OM) and scanning electron microscopy (SEM) to determine the as-irradiated microstructure. To demonstrate the irradiation performance of U-7Mo dispersion fuel plates with 2 wt.% Si added to the matrix, fuel plates were tested to moderate burnups at intermediate fission rates as part of the RERTR-6 experiment. Further testing was performed to higher fission rates as part of the RERTR-7A experiment, and very aggressive testing (high temperature, high fission density, and high fission rate) was performed in the RERTR-9A, RERTR-9B, and AFIP-1 experiments. As-irradiated microstructures were compared to those observed after fabrication to determine the effects of irradiation on the microstructure. Based on comparison of the microstructural characterization results for each irradiated sample, some general conclusions can be drawn about how the microstructure evolves during irradiation: there is growth during irradiation of the fuel/matrix interaction (FMI) layer created during fabrication; Si diffuses from the FMI layer to deeper depths in the U-7Mo particles as the irradiation conditions are made more aggressive; lowering of the Si content in the FMI layer results in an increase in the size of the fission gas bubbles; as the FMI layer grows during irradiation, more Si diffuses from the matrix to the FMI layer/matrix interface; and interlinking of fission gas bubbles in the fuel plate microstructure that may indicate breakaway swelling is not observed.

  16. Effects of irradiation on the microstructure of U-7Mo dispersion fuel with Al-2Si matrix

    Energy Technology Data Exchange (ETDEWEB)

    Keiser, Dennis D., E-mail: Dennis.Keiser@inl.gov [Nuclear Fuels and Materials Division, Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415-6188 (United States); Jue, Jan-Fong; Robinson, Adam B.; Medvedev, Pavel; Gan, Jian; Miller, Brandon D.; Wachs, Daniel M.; Moore, Glenn A.; Clark, Curtis R.; Meyer, Mitchell K. [Nuclear Fuels and Materials Division, Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415-6188 (United States); Ross Finlay, M. [Australian Nuclear Science and Technology Organization, PMB 1, Menai, NSW 2234 (Australia)

    2012-06-15

    The Reduced Enrichment for Research and Test Reactor (RERTR) program is developing low-enriched uranium U-Mo dispersion fuels for application in research and test reactors around the world. As part of this development, fuel plates have been irradiated in the Advanced Test Reactor and then characterized using optical metallography (OM) and scanning electron microscopy (SEM) to determine the as-irradiated microstructure. To demonstrate the irradiation performance of U-7Mo dispersion fuel plates with 2 wt.% Si added to the matrix, fuel plates were tested to moderate burnups at intermediate fission rates as part of the RERTR-6 experiment. Further testing was performed to higher fission rates as part of the RERTR-7A experiment, and very aggressive testing (high temperature, high fission density, and high fission rate) was performed in the RERTR-9A, RERTR-9B, and AFIP-1 experiments. As-irradiated microstructures were compared to those observed after fabrication to determine the effects of irradiation on the microstructure. Based on comparison of the microstructural characterization results for each irradiated sample, some general conclusions can be drawn about how the microstructure evolves during irradiation: there is growth during irradiation of the fuel/matrix interaction (FMI) layer created during fabrication; Si diffuses from the FMI layer to deeper depths in the U-7Mo particles as the irradiation conditions are made more aggressive; lowering of the Si content in the FMI layer results in an increase in the size of the fission gas bubbles; as the FMI layer grows during irradiation, more Si diffuses from the matrix to the FMI layer/matrix interface; and interlinking of fission gas bubbles in the fuel plate microstructure that may indicate breakaway swelling is not observed.

  17. The fuel index method as a new planning instrument in the erection and redevelopment of residential estates; Das Brennstoffkennzahl-Verfahren als neues Planungsinstrument fuer Neubau- und Sanierungsvorhaben

    Energy Technology Data Exchange (ETDEWEB)

    Elsenberger, U. [Industrie und Communal Consulting GmbH, Aachen (Germany); Boese, M.; Diefenbach, N.; Petersdorff, C.; Schultze, K. [Rheinisch-Westfaelische Technische Hochschule Aachen (Germany). 3. Physikalisches Inst. A

    1998-12-31

    The fuel index method aims at the largest possible exploitation of conservation potentials in residential thermal energy supply. The introduction of a thermal quality standard for thermal energy systems lays the foundation in process engineering terms for a competition between environment-friendly thermal energy supply and thermal insulation, with the aim to save energy and cost. Using higher-grade thermal energy at higher cost than current energy costs is approved of if its use involves an ambitious conservation aim. In this way, particularly rational energy techniques are promoted. (orig.) [Deutsch] Das Brennstoffkennzahl-Verfahren zielt auf eine effektive Erschliessung weitgehender Einsparziele bei der Waermeversorgung von Wohngebieten. Mit der Einfuehrung der Waermequalitaet als Guetemass eines Waermeversorgungssystems werden die verfahrenstechnischen Grundlagen fuer eine auf kostenguenstige Energieeinsparung ausgerichtete Konkurrenz zwischen umweltfreundlicher Waermeversorgung und Waermeschutz geschaffen. Waerme hoeherer Qualitaet darf bei Vorgabe eines ehrgeizigen Einsparziels teurer sein als heute ueblich. Damit wird der Einsatz besonders rationeller Energietechniken gefoerdert. (orig.)

  18. Inhibition of ammonia poisoning by addition of platinum to Ru/α-Al2 O3 for preferential CO oxidation in fuel cells.

    Science.gov (United States)

    Sato, Katsutoshi; Yagi, Sho; Zaitsu, Shuhei; Kitayama, Godai; Kayada, Yuto; Teramura, Kentaro; Takita, Yusaku; Nagaoka, Katsutoshi

    2014-12-01

    In polymer electrolyte fuel cell (PEFC) systems, small amounts of ammonia (NH3 ) present in the reformate gas deactivate the supported ruthenium catalysts used for preferential oxidation (PROX) of carbon monoxide (CO). In this study, we investigated how the addition of a small amount of platinum to a Ru/α-Al2 O3 catalyst (Pt/Ru=1:9 w/w) affected the catalyst's PROX activity in both the absence and the presence of NH3 (130 ppm) under conditions mimicking the reformate conditions during steam reforming of natural gas. The activity of undoped Ru/α-Al2 O3 decreased sharply upon addition of NH3 , whereas Pt/Ru/α-Al2 O3 exhibited excellent PROX activity even in the presence of NH3 . Ruthenium K-edge X-ray absorption near-edge structure (XANES) spectra indicated that in the presence of NH3 , some of the ruthenium in the undoped catalyst was oxidized in the presence of NH3 , whereas ruthenium oxidation was not observed with Pt/Ru/α-Al2 O3 . These results suggest that ruthenium oxidation is retarded by the platinum, so that the catalyst shows high activity even in the presence of NH3 . © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Improvement of performance in low temperature solid oxide fuel cells operated on ethanol and air mixtures using Cu-ZnO-Al2O3 catalyst layer

    Science.gov (United States)

    Morales, M.; Espiell, F.; Segarra, M.

    2015-10-01

    Anode-supported single-chamber solid oxide fuel cells with and without Cu-ZnO-Al2O3 catalyst layers deposited on the anode support have been operated on ethanol and air mixtures. The cells consist of gadolinia-doped ceria electrolyte, Ni-doped ceria anode, and La0.6Sr0.4CoO3-δ-doped ceria cathode. Catalyst layers with different Cu-ZnO-Al2O3 ratios are deposited and sintered at several temperatures. Since the performance of single-chamber fuel cells strongly depends on catalytic properties of electrodes for partial oxidation of ethanol, the cells are electrochemically characterized as a function of the temperature, ethanol-air molar ratio and gas flow rate. In addition, catalytic activities of supported anode, catalytic layer-supported anode and cathode for partial oxidation of ethanol are analysed. Afterwards, the effect of composition and sintering temperature of catalyst layer on the cell performance are determined. The results indicate that the cell performance can be significantly enhanced using catalyst layers of 30:35:35 and 40:30:30 wt.% Cu-ZnO-Al2O3 sintered at 1100 °C, achieving power densities above 50 mW cm-2 under 0.45 ethanol-air ratio at temperatures as low as 450 °C. After testing for 15 h, all cells present a gradual loss of power density, without carbon deposition, which is mainly attributed to the partial re-oxidation of Ni at the anode.

  20. La diversidad sexual: contribuciones para pensar el vínculo de pareja

    OpenAIRE

    Martínez, Ariel

    2009-01-01

    Objetivos: El presente trabajo, se propone: - Delimitar diferentes aproximaciones al estudio de la sexualidad - Deslindar el impacto de las categorías de género e identidad en el abordaje teórico de la diversidad sexual. Metodología: Se realiza un análisis cualitativo de contenido bibliográfico que incluye, entre otras actividades: identificación de fuentes bibliográficas (primarias 15 y secundarias), sistematización de los datos relevados y análisis de los resultados.

  1. Upgrading of the liquid fuel from fast pyrolysis of biomass over MoNi/γ-Al2O3 catalysts

    International Nuclear Information System (INIS)

    Xu, Ying; Wang, Tiejun; Ma, Longlong; Zhang, Qi; Liang, Wei

    2010-01-01

    The hydrotreatment of bio-oil, which obtained from fast pyrolysis of pine sawdust, was investigated over MoNi/γ-Al 2 O 3 catalyst under mild conditions (373 K, 3 MPa hydrogen pressure). Acetic acid was taken as a model compound to investigate the effects of Mo promoter contents and reducing temperatures of catalysts on the catalysts activity under the condition of 473 K and 3 MPa hydrogen pressure. X-ray diffraction and temperature programmed reduction showed that the addition of Mo promoter benefited the uniformity of nickel species and inhibited the formation of NiAl 2 O 4 spinel in the catalysts. The GC spectrum of liquid products showed the mechanism of the model reaction. The maximum conversion of acetic acid (33.20%) was attained over 0.06MoNi/γ-Al 2 O 3 catalysts being reduced at 873 K. This catalyst was chosen for the upgrading of raw bio-oil. After the upgrading process, the pH value of the bio-oil increased from 2.33 to 2.77. The water content increased from 35.52 wt.% to 41.55 wt.% and the gross calorific value increased from 13.96 MJ/kg to 14.17 MJ/kg. The hydrogen content in the bio-oil increased from 6.25 wt.% to 6.95 wt.%. The product properties of the upgraded bio-oil, particularly the hydrogen content and the acidity were considerably improved. The results of gas chromatography-mass spectrometry analysis showed that both hydrotreatment and esterification had happened over 0.06MoNi/γ-Al 2 O 3 (873) catalyst during the upgrading process.

  2. Hábeas Corpus: contribuciones a la causa del estado de derecho

    Directory of Open Access Journals (Sweden)

    Norma Bouyssou

    2016-09-01

    Full Text Available La garantía del hábeas corpus despliega, con total humildad, razones para la permanente expansión de la libertad o bien para su contínuo resguardo. Su bajo perfil, sin embargo, es confundido con indiferencia en orden a su compromiso con la causa de la ciencia del derecho; ello se explica, por un lado, debido a la generalizada creencia que su reconocimiento expreso como derecho positivo -en los más altos niveles normativos-, es anticuerpo suficiente para puestas en peligro o atentados directos contra la autonomía personal a manos del Estado y, por el otro, lógicamente anclado en el predio precedente, en una suerte de desubicación contemporánea frente a un punto de partida de contención teorético (y en desuso del abuso del poder político, al que no obstante se le exigen soluciones con mayor intervención fáctica (y menos frenos en las relaciones sociales, aunque necesariamente adecuadas al orden anterior. Corresponde exponer la disconformidad con los pies en claves propias a la ciencia jurídica, sin hacer a un lado lo pragmático, método dual que se aplicará sobre la excursión que sigue, a la que se invita.

  3. Improvement of the Oxidation Resistance of CoNiCrAlY Bond Coats Sprayed by High Velocity Oxygen-Fuel onto Nickel Superalloy Substrate

    Directory of Open Access Journals (Sweden)

    Alessio Fossati

    2010-11-01

    Full Text Available CoNiCrAlY powders with similar granulometry and chemical composition, but different starting reactivity toward oxygen, were sprayed onto superalloy substrates by High Velocity Oxygen-Fuel producing coatings of similar thicknesses. After spraying, samples were maintained at 1,273 K in air for different test periods of up to 5,000 hours. Morphological, microstructural, compositional and electrochemical analyses were performed on the coated samples in order to assess the high temperature oxidation resistance provided by the two different powders. The powder with higher starting reactivity towards oxygen improves the oxidation resistance of the coated samples by producing thinner and more adherent thermally grown oxide layers.

  4. Diversidad, música y competencia social y ciudadana: contribuciones de la experiencia musical

    Directory of Open Access Journals (Sweden)

    Bermell Corral, M.ª Ángeles

    2014-10-01

    Full Text Available Educational legislation is obliged to ensure the curriculum is adapted to enable the full development of the necessary basic skills. Teachers have to differentiate pupils’ curricula according to their cognitive, cultural and social constraints, so that each individual can develop into a socially competent citizen. This article describes how musical experience is affordable, effective and motivating for pupils included classed as requiring “attention to diversity,” and how it can contribute to this group’s acquisition of social and civic competences. In attention to diversity, music in has a vital role in primary schools, boosting self-esteem, independence, initiative, and contributing to the development of essential social and civic skills considered essential for sociocultural development.La legislación educativa tiene la obligación de garantizar las adaptaciones curriculares necesarias para desarrollar al máximo las Competencias Básicas. El profesorado debe diferenciar el currículo de los educandos en función de sus limitaciones cognitivas, culturales y sociales, para que todos puedan convertirse en ciudadanos competentes socialmente. Este artículo muestra cómo la experiencia musical es accesible, efectiva y motivadora para el alumnado incluido en la atención a la diversidad, y cómo debido a ello podrá contribuir a la adquisición de la competencia social y ciudadana por este colectivo. Entonces, la Música en la atención a la diversidad en Primaria tiene un papel vital, puesto que además de incrementar la autoestima, la autonomía, la iniciativa personal, contribuirá al desarrollo de la competencia social y ciudadana considerada imprescindible para un adecuado desarrollo sociocultural.

  5. Uruguay geology contributions no. 4; Contribuciones a la geologia del Uruguay no. 4

    Energy Technology Data Exchange (ETDEWEB)

    Preciozzi, F [Ministerio de Industria Energia y Mineria, Direccion Nacional de Mineria y Geologia, Montevideo (Uruguay)

    1989-07-01

    Sedimentary facies: the metasiltites and mela sandstones develop granoblastic textures. The present lepidoblastic textures in flexured bands of seri cite and/or chlorite, a fine qranoblastic matrix made by quartz-feldespaths. The carbonates develop mosaic textures with big crystals of calcites and dolomite, generally elongated following metamorphic foliation (seri cite/chlorite). The quartzites develop qranoblastic textures, with few minerals. Volcanics facies: the basic volcanics presents doleritic intersect al textural, that exist saussuritized plagioclase and albitic diabasa with diopside-augite beaches. Usually the pyroxenes develop poiquilitic textural. Present amphiboles of the acti note series and frequently sphene. Others basic rocks are microlitio porfiric, in intersect al or fluidal matrix, with albite microliters in epi dote-chlorite-acti note criploerislalline ground.The stability relationships of the diferents types of basic metavulcanites show low metamorphic facies, with temperatures under 530-550 grades C, being the most Irequenl association: albite+actinote+chlorite+epidote+opaques- opaques.The clastic faciest are integrated by monogenic breccia with elements of varied vulcanites and porfiric rnicrolitic texture. The matrix is made of line quartz and epidote aggregate. The basic volcanism present hyalo-porfiric textures with saussuritized plagiodase pheno crystals, and quartz in a micro lo criptocrystalline ground. Were also defined rocks with porfiric texture in a piromeritic ground as well as rocks with vacuolar microlitic texture.The clastic facies are made by breccias with sharp elements, with rare cement, integrated by pyroclastic products, The volcanics rocks present retrometamorphism of the phenocrystals and devitrification. The plagioclase are traslormated in fine aggregates of albite epidote. The regional metamorphism minerals are represented by the para genesis: quartz+albite+chlorite+epidote+(seri cite-actinole), subfacies quartz albite

  6. Behavior of U3Si2 Fuel and FeCrAl Cladding under Normal Operating and Accident Reactor Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Gamble, Kyle Allan Lawrence [Idaho National Lab. (INL), Idaho Falls, ID (United States); Hales, Jason Dean [Idaho National Lab. (INL), Idaho Falls, ID (United States); Barani, Tommaso [Idaho National Lab. (INL), Idaho Falls, ID (United States); Pizzocri, Davide [Idaho National Lab. (INL), Idaho Falls, ID (United States); Pastore, Giovanni [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-09-01

    As part of the Department of Energy's Nuclear Energy Advanced Modeling and Simulation program, an Accident Tolerant Fuel High Impact Problem was initiated at the beginning of fiscal year 2015 to investigate the behavior of \\usi~fuel and iron-chromium-aluminum (FeCrAl) claddings under normal operating and accident reactor conditions. The High Impact Problem was created in response to the United States Department of Energy's renewed interest in accident tolerant materials after the events that occurred at the Fukushima Daiichi Nuclear Power Plant in 2011. The High Impact Problem is a multinational laboratory and university collaborative research effort between Idaho National Laboratory, Los Alamos National Laboratory, Argonne National Laboratory, and the University of Tennessee, Knoxville. This report primarily focuses on the engineering scale research in fiscal year 2016 with brief summaries of the lower length scale developments in the areas of density functional theory, cluster dynamics, rate theory, and phase field being presented.

  7. Solar energy as fuel to move the world; La energia solar como combustible para mover al mundo

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, Arturo; Gamboa, Sergio [Centro de Investigacion en Energia (CIE) de la UNAM, Temixco, Morelos (Mexico)

    2010-07-01

    Among the technologies that can be used to take properly advantage of the Sun, we have the development of various solar devices, ranging from the solar collectors, equipment that convert the solar radiation into heat, until the solar cells that convert sunlight into electricity. The development and implementation of these devices in various countries of the world, has allowed us to evaluate the technical feasibility of the technologies associated with the development and use of Renewable Energies to solve the global energy problems, and, in this way, achieve the long-awaited energy independence to which aspire all the nations of the planet. [Spanish] Entre las tecnologias que se pueden utilizar para aprovechar de forma adecuada al Sol, tenemos el desarrollo de diversos dispositivos solares, los cuales van desde los captadores solares, equipos que convierten la radiacion solar en calor, hasta las celdas solares, que convierten la luz del Sol en electricidad. El desarrollo e implementacion de estos dispositivos en diversos paises del mundo, han permitido evaluar la factibilidad tecnica de las tecnologias asociadas al aprovechamiento y uso de las Energias Renovables para resolver los problemas energeticos globales, y, de esta forma, conseguir la tan ansiada independencia energetica a la que aspiran todas las naciones del planeta.

  8. Psicología comunitaria y expresiones psicosociales de la pobreza: contribuciones para la intervención en políticas públicas

    OpenAIRE

    Morais Ximenes, Verônica; Camurça Cidade, Elívia; Barbosa Nepomuceno, Bárbara

    2015-01-01

    El objetivo de este trabajo es analizar, desde la psicología comunitaria, las expresiones psicosociales de la pobreza y sus contribuciones para la intervención en políticas públicas. La psicología comunitaria critica los factores perpetuadores de aspectos materiales y simbólicos que interfieren en la constitución subjetiva de los pobres. La investigación exploratoria, de carácter cuantitativo y cualitativo, fue realizada con 417 sujetos adultos de dos comunidades de Brasil, una rural y otra u...

  9. Contribuciones del paradigma cultural latinoamericano a la comunicación para el desarrollo. Antecedentes, textos y contextos de una relación fecunda

    OpenAIRE

    Salazar Martínez, Rafael Ángel; Universidad de Holguín “Oscar Lucero Moya”,; Portal Moreno, Rayza; Universidad de La Habana; Fonseca Valido, Rafael Ángel; Universidad de Oriente

    2016-01-01

    Durante la década de 1980 se produce una ruptura en la investigación comunicológica latinoamericana, cuyo resultado fue el nacimiento de un nuevo paradigma que se apropia y hace uso de una concepción antropológica de la cultura, desde la cual comienzan a abordarse los procesos comunicativos. Las contribuciones de este paradigma a la comunicación para el desarrollo, campo que en América Latina ya contaba con una larga tradición, han resultado particularmente significativas. A examinar y discut...

  10. Detailed measurements of local thickness changes for U-7Mo dispersion fuel plates with Al-3.5Si matrix after irradiation at different powers in the RERTR-9B experiment

    Science.gov (United States)

    Keiser, Dennis D.; Williams, Walter; Robinson, Adam; Wachs, Dan; Moore, Glenn; Crawford, Doug

    2017-10-01

    The Materials Management and Minimization program is developing fuel designs to replace highly enriched fuel with fuels of low enrichment. Swelling is an important irradiation behavior that needs to be well understood. Data from high resolution thickness measurements performed on U-7Mo dispersion fuel plates with Al-Si alloy matrices that were irradiated at high power is sparse. This paper reports the results of detailed thickness measurements performed on two dispersion fuel plates that were irradiated at relatively high power to high fission densities in the Advanced Test Reactor in the same RERTR-9B experiment. Both plates were irradiated to similar fission densities, but one was irradiated at a higher power than the other. The goal of this work is to identify any differences in the swelling behavior when fuel plates are irradiated at different powers to the same fission densities. Based on the results of detailed thickness measurments, more swelling occurs when a U-7Mo dispersion fuel with Al-3.5Si matrix is irradiated to a high fission density at high power compared to one irradiated at a lower power to high fission density.

  11. Carbon nanotubes as electrode substrate material for PEM fuel cells; Kohlenstoff-Nanoroehrchen als Elektrodenmaterial fuer PEM-Brennstoffzellen

    Energy Technology Data Exchange (ETDEWEB)

    Soehn, Matthias

    2010-06-21

    This thesis reports an enhanced method to deposit nanoscaled noble metal catalysts (Pt/Ru) uniformly on carbon nanotubes based on wet chemical reduction of anorganic precursors via ethylene glycol. This well-known method is widely used to deposit noble metal catalyst particles on carbon black. Unfortunately, carbon nanotubes tend to agglomerate and therefore form bundles which cannot be penetrated by the precursor. Thus, effectiveness of the substrate is reduced. The new method prevents this by suspending the CNTs in butyl acetate by means of ultrasonic dispersion leading to a homogenous distribution. Because the butyl acetate is almost unpolar, it is nearly immiscible with the water-based ethylene glycol mixture. This problem has been solved by adding liquid Nafion {sup registered} which acts as an emulsifying agent. Thus an emulsion is created by ultrasonic treatment. This results in 30 {mu}m-sized droplets of butyl acetate with a layer of CNTs and Nafion {sup registered}. The large interface to the ethylene glycol phase yields a large surface for homogenous catalyst deposition. The prepared samples showed a narrow size distribution ({+-}0.5 nm) of small noble metal particles with loading up to 50% by weight and an average particle size of 3 nm. They are investigated using XRD, SEM, TEM, TGA-MS and CV. The added Nafion {sup registered} improves catalyst utilisation by establishing a proton conductive path to the catalyst particles. Furthermore, different manufacturing techniques for the CNT electrodes are evaluated. Thin layer Membrane-Electrode-Assemblies (MEAs) are prepared by the airbrush technique. Electrode thickness, composition and structure as well as membrane thickness is varied and the MEAs are tested in a single-cell hydrogen-oxygen-fed PEM fuel cell. The cells are characterised by cyclic IV curves which are recorded over an extended period of time, showing power densities up to 770mWcm-2 at a platinum loading of 0.3mgcm-2. Additionally, the MEAs are

  12. Evaluation of the interfacial shear strength and residual stress of TiAlN coating on ZIRLO™ fuel cladding using a modified shear-lag model approach

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Y., E-mail: troy.liu@manchester.ac.uk [Materials Performance Centre, School of Materials, The University of Manchester, M13 9PL (United Kingdom); Bhamji, I., E-mail: imran.bhamji@manchester.ac.uk [Materials Performance Centre, School of Materials, The University of Manchester, M13 9PL (United Kingdom); Withers, P.J., E-mail: p.j.withers@manchester.ac.uk [Materials Performance Centre, School of Materials, The University of Manchester, M13 9PL (United Kingdom); Wolfe, D.E., E-mail: dew125@arl.psu.edu [The Pennsylvania State University, University Park, State College, PA 16801 (United States); Motta, A.T., E-mail: atmnuc@engr.psu.edu [The Pennsylvania State University, University Park, State College, PA 16801 (United States); Preuss, M., E-mail: michael.preuss@manchester.ac.uk [Materials Performance Centre, School of Materials, The University of Manchester, M13 9PL (United Kingdom)

    2015-11-15

    This paper investigates the residual stresses and interfacial shear strength of a TiAlN coating on Zr–Nb–Sn–Fe alloy (ZIRLO™) substrate designed to improve corrosion resistance of fuel cladding used in water-cooled nuclear reactors, both during normal and exceptional conditions, e.g. a loss of coolant event (LOCA). The distribution and maximum value of the interfacial shear strength has been estimated using a modified shear-lag model. The parameters critical to this analysis were determined experimentally. From these input parameters the interfacial shear strength between the TiAlN coating and ZIRLO™ substrate was inferred to be around 120 MPa. It is worth noting that the apparent strength of the coating is high (∼3.4 GPa). However, this is predominantly due to the large compressive residuals stress (3 GPa in compression), which must be overcome for the coating to fail in tension, which happens at a load just 150 MPa in excess of this.

  13. Contribuciones a la técnica de la prostatectomía suprapúbica

    Directory of Open Access Journals (Sweden)

    Fabio Murillo Rivera

    1949-01-01

    Full Text Available En el panorama quirúrgico de la Urología domina el problema de la obstrucción prostática y hacia él se han dirigido la mayoría de las inquietudes de todo cirujano que transita en este delicado campo; su máxima aspiración es rodear al paciente de las mejores condiciones para realizar el acto operatorio, proporcionar la mayor seguridad para su vida durante aquél, empleando la técnica más apropiada a su caso particular, darle un período postoperatorio cómodo y rápido, y por sobre todo, alcanzar resultados finales satisfactorios desde el punto de vista funcional. Así vemos que en transcurso evolutivo de la cirugía prostática han aparecido diversidad de técnicas y preceptos para lograr esta finalidad, no de otra manera hubiéramos conocido las ventajas de los métodos transuretrales, la vía perineal, la clásica suprapúbica en uno o en dos tiempos y posteriormente la técnica de la prostatectomía retropúbica de Terence Millin con las modificaciones aconsejadas por Oswald Lowsley.

  14. SEM in situ MiniCantilever Beam Bending of U-10Mo/Zr/Al Fuel Elements

    Energy Technology Data Exchange (ETDEWEB)

    Mook, William [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Baldwin, Jon K. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Martinez, Ricardo M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Mara, Nathan A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-06-16

    In this work, the fracture behavior of Al/Zr and Zr/dU-10Mo interfaces was measured via the minicantilever bend technique. The energy dissipation rates were found to be approximately 3.7-5 mj/mm2 and 5.9 mj/mm2 for each interface, respectively. It was found that in order to test the Zr/U-10Mo interface, location of the hinge of the cantilever was a key parameter. While this test could be adapted to hot cell use through careful alignment fixturing and measurement of crack lengths with an optical microscope (as opposed to SEM, which was used here out of convenience), machining of the cantilevers via MiniMill in such a way as to locate the interfaces at the cantilever hinge, as well as proper placement of a femtosecond laser notch will continue to be key challenges in a hot cell environment.

  15. Urea-nitrate combustion synthesis of MgO/MgAl2O4 nanocatalyst used in biodiesel production from sunflower oil: Influence of fuel ratio on catalytic properties and performance

    International Nuclear Information System (INIS)

    Rahmani Vahid, Behgam; Haghighi, Mohammad

    2016-01-01

    Graphical abstract: As a base catalyst for biodiesel production, MgAl 2 O 4 spinel was successfully synthesized by combustion method with MgO, as the active phase, dispersed on the catalyst surface. The nanocatalysts were characterized by XRD, FESEM, EDX, BET-BJH, TGA and FTIR analyses, so as to optimize the concentration of urea (as fuel) in the combustion synthesis. Analyzing the effect of fuel ratio on the combustion synthesized MgAl 2 O 4 , it was revealed that the synthesized base catalyst with a fuel ratio of 1.5 was of the best specifications for biodiesel production process. Future researches may investigate the catalyst reusability and mild reaction conditions, so as to achieve more economical production of biodiesel. - Highlights: • Efficient synthesis of MgAl 2 O 4 spinel by solution combustion method. • Improvement of catalytic activity and stability by optimum ratio fuel. • Enhanced dispersion of MgO over MgAl 2 O 4 spinel. • Production of biodiesel over MgO/MgAl 2 O 4 at relatively mild reaction conditions. - Abstract: MgO/MgAl 2 O 4 nanocatalyst was synthesized by a simple, cost-effective and rapid method and used in biodiesel production from sunflower oil. MgAl 2 O 4 was synthesized by combustion method at different fuel ratios and then active phase of MgO was dispersed on the samples by impregnation method. The nanocatalysts were characterized by XRD, FESEM, EDX, BET-BJH, TGA and FTIR analyses, so as to optimize the concentration of urea (as fuel) in the combustion synthesis. The physicochemical properties of the nanocatalyst confirmed the sample synthesized with fuel ratio of 1.5 has high surface area, effective morphology and texture properties. Finally, in order to evaluate catalytic activity of the samples in biodiesel production, the transesterification reaction was performed. The results indicated the catalyst prepared by combustion synthesis with a fuel ratio of 1.5 was optimum specifications for biodiesel production. Using this

  16. Contribuciones tecnicas para la medida de la contaminacion electromagnetica de microondas. Estudio en diversas poblaciones

    Science.gov (United States)

    Segura Garcia, Jaume

    La contaminacion ambiental por campos electromagneticos ha resultado ser en estos ultimos anos uno de los problemas mas acuciantes del panorama tecnologico y de salud publica. En el primero de los casos porque las inversiones realizadas son enormes y en el segundo porque cada vez es mayor el numero de articulos, "technical reports" e informes medicos que afirman la existencia de una cierta causalidad, aunque sea debil, entre los campos electromagneticos y ciertos cuadros sintomatologicos. En nuestro caso, hemos dedicado bastantes esfuerzos a investigar el llamado "sindrome de radiofrecuencia / microondas", denominado asi en la literatura cientifica por presentarse en operarios de estaciones de radar y en trabajadores de potentes emisoras de radio y television. En esta memoria presentamos un resumen del trabajo realizado durante los ultimos anos en la medida de la contaminacion electromagnetica ambiental asociado a las comunicaciones inalambricas. En ella se recogen los fundamentos fisicos y propiedades de las ondas electromagneticas, la tecnologia empleada en los sistemas de telefonia celular y los antecedentes relativos a la investigacion de la interaccion de las ondas electromagneticas con organismos vivos. Se desarrolla un procedimiento de medida que ha conducido a la elaboracion de los primeros "mapas de radiofrecuencia" similares, en el aspecto descriptivo, a los mapas de ruido desarrollados en el area de la contaminacion acustica. Por ultimo, se analiza la respuesta subjetiva de los residentes, personas que viven en el entorno de cobertura de las estaciones base de telefonia movil y que se ven sometidos a determinados niveles de radiacion electromagnetica, con el fin de situar este fenomeno al nivel que le corresponde en el ambito de la respuesta subjetiva ciudadana.

  17. ARG (juegos de realidad alternativa. Contribuciones, limitaciones y potencialidades para la docencia universitaria

    Directory of Open Access Journals (Sweden)

    Teresa Piñeiro Otero

    2015-01-01

    Full Text Available La ludificación de la educación ha representado una oportunidad para fomentar la interacción, la motivación y la participación del alumnado. Los ARG (las siglas inglesas de juegos de realidad alternativa ofrecen una nueva herramienta altamente inmersiva que puede implementarse en el logro de los objetivos docentes. Uno de sus puntos fuertes consiste en la suma de esfuerzos y recursos (la llamada inteligencia colectiva aplicada a la resolución de problemas. A esto se añade su combinación de plataformas en los entornos online y offline, lo que favorece el «realismo» de la experiencia. En este sentido, el presente trabajo pretende condensar las potencialidades, limitaciones y retos de los ARG al servicio de la educación universitaria. Basándose, a nivel metodológico, en la elaboración de un corpus teórico relevante y adecuado, analiza el potencial educativo de esta herramienta que, en ámbitos como el marketing o la comunicación corporativa ya ha despegado con éxito, pero que en el área educativa todavía no había sido abordada en profundidad. Recopila, además, ejemplos satisfactorios que se han desarrollado en diversas disciplinas académicas en otros países y que no resultan fácilmente localizables. Se concluye que, dados los antecedentes, potencialidades y análisis expuesto, debe valorarse la posibilidad de incorporar los juegos de realidad alternativa a la práctica de la docencia universitaria en el marco de una estrategia educativa que determine sus objetivos y sistema de evaluación más adecuado.

  18. Contribuciones para el desarrollo de programas para talentosos dentro del centro educativo

    Directory of Open Access Journals (Sweden)

    Sheyla Blumen de Pardo

    2013-09-01

    Full Text Available Un gran número de alumnos en nuestros centros educativos posee habilidades de aprendizaje extraordinarias y talentos especiales en tal grado que sus necesidades educativas no logran ser totalmente cubiertas en los programas escolares regulares. Los programas educativos para niños talentosos son una parte lógica y esencial de cualquier programa escolar que reconozca y respete las diferencias individuales entre sus alumnos. La filosofía que guía esta propuesta se basa en que: (1 el niño es un ser humano único que posee habilidades y necesidades educativas individualizadas y (2 es responsabilidad de nuestros centros educativos primero identificar estas necesidades y habilidades y luego proveer el tipo de experiencias educativas que tiendan a satisfacer las necesidades individuales y desarrollar las habilidades de cada niño al máximo de sus potencialidades. A number of students in our schools possess learning abilities and specialized talents to such degree that their educational needs cannot be met in a regular school program. Special educational programs for the gifted and talented are an essential part of any school program which recognizes and respects individual differences among its pupils. The philosophy which guides our proposal is based on the belief that: (1 each child is a unique human being who possesses individual educational needs and abilities; and (2 it is the responsibility of our schools, first to identify those needs and abilities and then, to provide the educational experiences for meeting individual needs and developing each child's abilities to the fullest degree.

  19. Nuclear fuels

    International Nuclear Information System (INIS)

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

    2009-01-01

    fuel, Anticipated evolution of fuel in dry storage, Anticipated evolution of fuel in deep geological disposal); Boiling-water reactor fuel (Similarities, and differences with PWR fuel, Axial and radial zoning, Rod and channel box sizes, Poisoning and reactivity control, Cladding specific characteristics, Trends in fuel evolution); 3 - Liquid-metal-cooled fast reactor fuel: Fast-neutron irradiation damage in structural materials (Fast-neutron-induced damage in metals, What materials should be used?); Fuels and targets for fast-reactor transmutation (Fast reactors: reactors affording the ability to carry out effective actinide transmutation, Recycling: homogeneous, or heterogeneous?); 4 - gas-cooled reactor fuel: Particle fuel (From the initial concept to the advanced TRISO particle concept, Kernel fabrication processes, Particle coating by chemical vapor deposition, Fuel element fabrication: particle compaction, Characterization of fuel particles, and elements, From HTR fuel to VHTR and GFR fuels: the GAIA facility at CEA/Cadarache); Irradiation behavior of particle fuels (Particle fuel: a variety of failure modes for a high-strength object, The amoeba effect, Fission product behavior, and diffusion in particle fuels); Mechanical modeling of particle fuel; Very-high-temperature reactor (VHTR) fuel; Gas-cooled fast reactor (GFR) fuel (The specifications for GFR fuel, GFR fissile material, First containment baffler materials, GFR fuel element concepts); 5 - Research reactor fuels (A considerable feedback from experience, Conversion of French reactors to low-enriched (≤20% U-235)U 3 Si 2 fuel, Conversion of all reactors: R and D requirements for high-performance reactors, An 'advanced' research reactor fuel: UMo, The startup fuel for the Jules Horowitz Reactor (JHR) will still be U 3 Si 2 -Al; 6 - An instrument for future fuel research: the Jules Horowitz Reactor (JHR): Fuel irradiation experiments in JHR, JHR: a flexible instrument; 7 - Glossary-Index

  20. Nuclear fuels

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-07-01

    nature of spent nuclear fuel, Anticipated evolution of fuel in dry storage, Anticipated evolution of fuel in deep geological disposal); Boiling-water reactor fuel (Similarities, and differences with PWR fuel, Axial and radial zoning, Rod and channel box sizes, Poisoning and reactivity control, Cladding specific characteristics, Trends in fuel evolution); 3 - Liquid-metal-cooled fast reactor fuel: Fast-neutron irradiation damage in structural materials (Fast-neutron-induced damage in metals, What materials should be used?); Fuels and targets for fast-reactor transmutation (Fast reactors: reactors affording the ability to carry out effective actinide transmutation, Recycling: homogeneous, or heterogeneous?); 4 - gas-cooled reactor fuel: Particle fuel (From the initial concept to the advanced TRISO particle concept, Kernel fabrication processes, Particle coating by chemical vapor deposition, Fuel element fabrication: particle compaction, Characterization of fuel particles, and elements, From HTR fuel to VHTR and GFR fuels: the GAIA facility at CEA/Cadarache); Irradiation behavior of particle fuels (Particle fuel: a variety of failure modes for a high-strength object, The amoeba effect, Fission product behavior, and diffusion in particle fuels); Mechanical modeling of particle fuel; Very-high-temperature reactor (VHTR) fuel; Gas-cooled fast reactor (GFR) fuel (The specifications for GFR fuel, GFR fissile material, First containment baffler materials, GFR fuel element concepts); 5 - Research reactor fuels (A considerable feedback from experience, Conversion of French reactors to low-enriched ({<=}20% U-235)U{sub 3}Si{sub 2} fuel, Conversion of all reactors: R and D requirements for high-performance reactors, An 'advanced' research reactor fuel: UMo, The startup fuel for the Jules Horowitz Reactor (JHR) will still be U{sub 3}Si{sub 2}-Al; 6 - An instrument for future fuel research: the Jules Horowitz Reactor (JHR): Fuel irradiation experiments in JHR, JHR: a flexible

  1. On the oxidation and combustion of AlH{sub 3} a potential fuel for rocket propellants and gas generators

    Energy Technology Data Exchange (ETDEWEB)

    Weiser, Volker; Eisenreich, Norbert; Koleczko, Andreas; Roth, Evelin [Fraunhofer-Institut fuer Chemische Technologie (ICT), Joseph-von-Fraunhoferstrasse 7, 76327 Pfinztal (Germany)

    2007-06-15

    Aluminum hydride is a promising candidate for application in energetic materials and hydrogen storages. E.g. an AP/HTPB rocket propellant filled with alane was calculated for a 100 N s kg{sup -1} higher specific impulse compared to the same concentration of aluminum. Different investigations on {alpha}-AlH{sub 3} polyhedra using thermoanalytical methods and X-ray diffraction were performed to receive a better understanding of dehydration at about 450 K, passivation of the remaining porous aluminum particles and further oxidation. A modeling approach to describe these conversions including diffusion processes, Avrami-Erofeev mechanism and Arrhenius type reaction steps of n-th order were introduced. Results were discussed in comparison to experimental investigations under pressure with model propellants on the base of gelled pure nitromethane and also filled with alane or pure aluminum in concentrations of 5%, 10% and 15%. Both alane and aluminum increase the burning rate on a factor of two correlated with a temperature increase up to 500 K and more. A mesa burning effect at 6 to 10 MPa was indicated by the mixtures with alane. (Abstract Copyright [2007], Wiley Periodicals, Inc.)

  2. Fuel cells are gaining ground. Fuel cells as a key technology: future potential, state of the art, economic aspects, practical reports. Proceedings. Brennstoffzellen auf dem Vormarsch. Die Brennstoffzelle als Schluesseltechnologie. Zukunftspotentiale, Stand der Technik, Wirtschaftlichkeit und Praxisberichte. Tagungsband

    Energy Technology Data Exchange (ETDEWEB)

    1999-01-01

    This conference report comprises 16 papers on fuel cells. Subjects: Funds for fuel cell technology provided by the 4. programme for energy research and energy technologies; Funds provided by the European Commission for demonstration projects; Fuel cells: Stationary applications in power supply; Liberalisation of the energy markets - effects on fuel cell development; Fuel cell technology from a utility's point of view; PEMFC membrane fuel cells; PFC in domestic energy supply; Applications of PEMFC in stationary power generation; Development of a fuel cell drive; Comparative evaluations of passenger car drives with fuel cells and internal combustion engines; Economic aspects of PAFC fuel cells; Development of the carbonate fuel cell (MCFC); Demonstration plant at Santa Clara (MCFC); Development, demonstration and application of oxide ceramics fuel cells SOFC, Experience with SOFC. Four contributions are available as separate records in this database.

  3. LA PERSPECTIVA HISTÓRICO-CULTURAL Y LA EDUCACIÓN ESPECIAL: CONTRIBUCIONES INICIALES Y DESARROLLOS ACTUALES

    Directory of Open Access Journals (Sweden)

    Albertina Mitjáns Martínez

    2009-01-01

    Full Text Available El objetivo principal del artículo es destacar la significación de la perspectiva histórico-cultural del desarrollo humano para el diseño de estrategias educativas favorecedoras del aprendizaje escolar de niños y niñas con deficiencias. A partir de las contribuciones de Vygotsky, en ese campo, y de los aportes de la Teoría de la Subjetividad, elaborada a partir da la perspectiva histórico-cultural, se presentan principios que, en su configuración sistémica, pueden constituir una base sólida para la reestructuración de diversos aspectos del trabajo educativo en la Educación Especial. En la primera parte del artículo son discutidas algunas de las concepciones y conceptos desarrollados por Vygotsky en su obra "Fundamentos de Defectología". La fundamentación del carácter social de la deficiencia, los conceptos de defecto primario, defecto secundario y compensación, y la consideración del carácter creativo del aprendizaje y del desarrollo de las niñas y los niños deficientes. Se presentan las ideas centrales de la Teoría de la Subjetividad elaborada por González Rey, especialmente la concepción del aprendizaje escolar como un proceso de la subjetividad irreducible a habilidades y procesos intelectuales. Por último, se fundamentan tres implicaciones educacionales derivadas de la articulación de los dos sistemas conceptuales presentados: favorecer la creación de espacios comunicativos/relacionales que contribuyan a generar en el niño nuevas producciones de sentido sobre el aprendizaje y sobre la deficiencia, estimular en ellos el desarrollo de la condición de sujetos negada por las posiciones asistencialistas y paternalistas dominantes y el enfoque cualitativo, constructivo, singular, procesual e interactivo de los procesos de diagnóstico y de evaluación educacional.

  4. Investigation of neutronic and safety parameters variation in 5 MW research reactor due to U{sub 3}O{sub 8}Al fuel conversion to ThO{sub 2} + U{sub 3}O{sub 8}Al

    Energy Technology Data Exchange (ETDEWEB)

    Gholamzadeh, Zohreh; Alipoor, Zahra; Mirvakili, Seyed Mohammad [Nuclear Science and Technology Research Institute, Tehran (Iran, Islamic Republic of). Reactor Research School; Feghhi, Seyed Amir Hossein [Shahid Beheshti Univ., Tehran (Iran, Islamic Republic of). Dept. of Radiation Application; Vahedi, M.; Bagheri, H. [Univ. of Science and Technology, Tehran (Iran, Islamic Republic of). Energy Dept.; Tenreiro, Claudio [Talca Univ. (Chile). Energy Dept.

    2017-05-15

    Thorium-based fuels could comprise several advantages and are being investigated as a potentially competitive option with uranium-based fuels for research or power reactors. The present study investigates computationally the application of two different thorium-based fuels in a research reactor. Void and temperature reactivity coefficients, safety factor, power peaking factor, neutron generation time, effective delayed neutron fraction and {sup 135}Xe worth parameter were investigated for the fuel conversions. The results showed both the investigated fuels would not significantly disturb neutronic and safety parameters of the modeled core in comparison with its routine fuel loading. However, 235-enriched thorium based fuel concluded in noticeably reduction of High Level Waste (HLW) but 233-enriched type could be taken in attention because of its longer fuel cycle (∝15 %) and integrated neutron flux (∝23 %).

  5. MTBE experts' discussion: Environmental pollution from MTBE fuel additives. Proceedings; MTBE-Fachgespraech: Umweltbelastungen durch die Nutzung von MTBE (Methyl-tertiaer-butylether) als Kraftstoffzusatz. Tagungsband

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-07-01

    MTBE is a volatile, water-soluble, oxygen-containing liquid with a high octane rating. It hardly absorbs to the soil matrix, is hardly degradable by biological means, and moves in groundwater at practically the same speed as the groundwater itself. This makes it an important groundwater hazard. The main problem is the low taste and smell threshold concentration of MTBE, because of which contaminated water is unfit for drinking. MTBE has been used as a fuel additive in the USA since the seventies and in Germany since the eighties for a better antiknock rating. MTBE concentrations depend on the fuel quality, ranging from 0.3 percent in normal gasoline and 1.6 percent in super gasoline to 6-12 percent by volume in SuperPlus and Optimax fuels. At this conference, which comprised nine lectures and a round of detailed discussions, measured concentrations of MTBE in air, precipitations, surface water and groundwater were presented, and the possibilities of modelling were discussed. The attendants of the meeting agreed that in view of the available data and at the present state of knowledge concerning the sources and fate of MTBE in environmental media, MTBE cannot be excluded as a groundwater pollutant. (orig.) [German] MTBE ist eine leichtfluechtige, gut wasserloesliche, sauerstoffhaltige Fluessigkeit mit hoher Oktanzahl. Es sorbiert fast nicht an die Bodenmatrix, ist sehr schlecht biologisch abbaubar und bewegt sich im Grundwasser praktisch mit der gleichen Geschwindigkeit wie das Grundwasser selbst. Aufgrund dieser Eigenschaften stellt MTBE eine Gefahr fuer das Grundwasser dar. Problematisch aus Sicht der Wasserversorgung ist die niedrige Geruchs- und Geschmacksschwelle von MTBE, weshalb kontaminiertes Wasser nicht mehr als Trinkwasser brauchbar ist. MTBE wird seit Mitte der 70er Jahre in den USA und seit Anfang der 80er Jahre in Deutschland dem Benzin zugesetzt, um die Klopffestigkeit zu verbessern. Der MTBE-Gehalt haengt von der Benzin-Qualitaet ab: Waehrend

  6. Synthesis and Activity Test of Cu/ZnO/Al2O3 for the Methanol Steam Reforming as a Fuel Cell’s Hydrogen Supplier

    Directory of Open Access Journals (Sweden)

    IGBN Makertihartha

    2009-05-01

    Full Text Available The synthesis of hydrogen from hydrocarbons through the steam reforming of methanol on Cu/ZnO/Al2O3 catalyst has been investigated. This process is assigned to be one of the promising alternatives for fuel cell hydrogen process source. Hydrogen synthesis from methanol can be carried out by means of methanol steam reforming which is a gas phase catalytic reaction between methanol and water. In this research, the Cu/ZnO/Al2O3 catalyst prepared by the dry impregnation was used. The specific surface area of catalyst was 194.69 m2/gram.The methanol steam reforming (SRM reaction was carried out by means of the injection of gas mixture containing methanol and water with 1:1.2 mol ratio and 20-90 mL/minute feed flow rate to a fixed bed reactor loaded by 1 g of catalyst. The reaction temperature was 200-300 °C, and the reactor pressure was 1 atm. Preceding the reaction, catalyst was reduced in the H2/N2 mixture at 160 °C. This study shows that at 300 °C reaction temperature, methanol conversion reached 100% at 28 mL/minute gas flow rate. This conversion decreased significantly with the increase of gas flow rate. Meanwhile, the catalyst prepared for SRM was stable in 36 hours of operation at 260 °C. The catalyst exhibited a good stability although the reaction condition was shifted to a higher gas flow rate.

  7. Conversion of hot coke oven gas into light fuel gas over Ni/Al{sub 2}O{sub 3} catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Li, L.Y.; Morishita, K.; Takarada, T. [Gunma University, Gunma (Japan). Dept. of Biology & Chemical Engineering

    2006-04-15

    Conversion of hot coke oven gas (COG, containing tarry material) into light fuel gas over a Ni/Al{sub 2}O{sub 3} catalyst was studied. Laboratory scale tests were carried out in a two-stage fixed-bed reactor at ambient pressure. The nickel catalyst promoted the hydropyrolysis reaction of tarry materials. High yields of total product gas and methane were obtained at high hydrogen concentrations. If the hydrogen supply was adequate for hydropyrolysis of the tarry material, conversion of coal volatiles was high, at more than 95% on carbon balance, even with a gas residence time as short as 0.15 s in the catalyst bed. The product gas yield depended on catalytic temperature. At 923 K, the maximum conversion of coal volatiles into the light gas was achieved at 95.0% on carbon balance, with methane 86.7 vol% of the carbonaceous gas product. Although carbon deposits deactivated the catalyst after a long period of use, the catalyst could be regenerated by treatment with oxygen at 800 K, providing high activity in subsequent decomposition of tarry material. The influence of sulphide on the tarry material decomposition reaction was small even in a 2000 ppm H{sub 2}S atmosphere.

  8. The role of various fuels on microwave-enhanced combustion synthesis of CuO/ZnO/Al2O3 nanocatalyst used in hydrogen production via methanol steam reforming

    International Nuclear Information System (INIS)

    Ajamein, Hossein; Haghighi, Mohammad; Alaei, Shervin

    2017-01-01

    Graphical abstract: CuO/ZnO/Al 2 O 3 nanocatalysts were synthesized by the fast and simple microwave enhanced combustion method. Considering that the fuel type is one of the effective parameters on quality of the prepared nanocatalysts, different fuels such as sorbitol, propylene glycol, glycerol, diethylene glycol and ethylene glycol were used. XRD, FESEM, FTIR, EDX, and BET analyses were applied to determine the physicochemical properties of fabricated nanocatalysts. The catalytic experiments were performed in a fixed bed reactor in the temperature range of 160–300 °C. The characteristic and reactivity properties of fabricated nanocatalysts proved that ethylene glycol is the suitable fuel for preparation of CuO/ZnO/Al 2 O 3 nanocatalysts via microwave enhanced combustion method. - Highlights: • Microwave combustion synthesis of CuO/ZnO/Al 2 O 3 nanocatalysts by different fuels. • Enhancement of methanol conversion at low temperatures by selecting proper fuel. • Providing a large number of combustion pores by application of ethylene glycol as fuel. • Increase of CO selectivity in steam methanol reforming by Zn(0 0 2) crystallite facet. - Abstract: A series of CuO/ZnO/Al 2 O 3 nanocatalysts were synthesized by the microwave enhanced combustion method to evaluate the influence of fuel type. Sorbitol, propylene glycol, glycerol, diethylene glycol and ethylene glycol were used as fuel. XRD results revealed that application of ethylene glycol led to highly dispersed CuO and ZnO crystals. It was more highlighted about Cu(1 1 1) crystallite facet which known as the main active site of methanol steam reforming. Moreover, using ethylene glycol resulted homogeneous morphology and narrow particles size distribution (average surface particle size is about 265 nm). Due to the significant physicochemical properties, the catalytic experiments showed that the sample prepared by ethylene glycol achieved total conversion of methanol at 260 °C. Its carbon monoxide

  9. The fuel cell as a energy center. The chances of utilization of sewage gas; Die Brennstoffzelle als Energiezentrum. Die Chancen der Verwertung von Klaergas

    Energy Technology Data Exchange (ETDEWEB)

    Berger, P. [CFC Solutions GmbH, Muenchen (Germany)

    2008-07-01

    The basis of the fuel cell power station of the CFC Solutions GmbH (Munich, Federal Republic of Germany) is the carbonate fuel cell, with which arbitrary gaseous fuels can be used for power generation. The reformation of the methane containing gaseous fuel to hydrogen in the fuel cell requires heat energy, which is obtained as waste heat of the cell reaction. Apart from the electricity by the fuel cell power station heat energy is produced. Thus the fuel cell power station also can be used for the production of process steam and production of coldness by means of an absorption refrigeration system. A further advantage is that for the fuel cell power station no hydrogen have to be manufactured. In comparison to the motoric heat and power cogeneration or small gas turbines thee are further advantages for fuel cell power stations: a) high electrical efficiency within the kilowatt range; b) high temperature useful heat; c) efficient cooling; d) Flexibility with the fuel (natural gas, fermentation gas, sewage gas); e) good extent of utilization of the power station; f) flexible interpretation and operation according to user requirement; g) premium power and USV applications; g) smallest emission to exhaust gas and noises.

  10. Study of the aqueous corrosion mechanisms and kinetics of the AlFeNi aluminium based alloy used for the fuel cladding in the Jules Horowitz research reactor; Etude des mecanismes et des cinetiques de corrosion aqueuse de l'alliage d'aluminium AlFeNi utilise comme gainage du combustible nucleaire de reacteurs experimentaux

    Energy Technology Data Exchange (ETDEWEB)

    Wintergerst, M.

    2009-05-15

    For the Jules Horowitz new material-testing reactor (JHR), an aluminium base alloy, called AlFeNi, will be used for the cladding of the fuel plates. This alloy (Al - 1% Fe - 1% Ni - 1 % Mg), which is already used as fuel cladding, was developed for its good corrosion resistance in water at high temperatures. However, few studies dealing with the alteration process in water and the relationships with irradiation effects have been performed on this alloy. The conception of the JHR fuel requires a better knowledge of the corrosion mechanisms. Corrosion tests were performed in autoclaves at 70 C, 165 C and 250 C on AlFeNi plates representative of the fuel cladding. Several techniques were used to characterize the corrosion scale: SEM, TEM, EPMA, XRD, Raman spectroscopy. Our observations show that the corrosion scale is made of two main layers: a dense amorphous scale close to the metal and a porous crystalline scale in contact with the water. More than the morphology, the chemical compositions of both layers are different. This duplex structure results from a mixed growth mechanism: an anionic growth to develop the inner oxide and a cationic diffusion followed by a dissolution-precipitation process to form the outer one. Dynamic experiments at 70 C and corrosion kinetics measurements have demonstrated that the oxide growth process is controlled by a diffusion step associated to a dissolution/precipitation process. A corrosion mechanism of the AlFeNi alloy in aqueous media has been proposed. Then post-irradiation exams performed on irradiated fuel plates were used to investigate the effects of the irradiation on the corrosion behaviour in the reactor core. (author)

  11. FUNCIONES ORTOGONALES EMPÍRICAS (EOF APLICADAS A LAS CUENCAS OCEÁNICAS TROPICALES INDO-PACÍFICA Y ATLÁNTICA: CONTRIBUCIONES AL ANÁLISIS DE LAS CONDICIONES DE COBERTURA DE NUBES EN EL PARQUE NACIONAL NATURAL LOS NEVADOS FUNÇÕES ORTOGONAIS EMPÍRICAS (EOF APLICADAS ÀS BACIAS OCEÂNICAS TROPICAIS INDO-PACÍFICA E ATLÂNTICA: CONTRIBUIÇÕES PARA A ANÁLISE DAS CONDIÇÕES DA COBERTURA DE NUVENS NO PARQUE NACIONAL NATURAL LOS NEVADOS INDO-PACIFIC AND TROPICAL ATLANTIC EOF MODES: CONTRIBUTIONS TO THE ANALYSES OF CLOUD COVER CONDITIONS IN THE LOS NEVADOS NATURAL PARK

    Directory of Open Access Journals (Sweden)

    DANIEL RUIZ CARRASCAL

    2010-12-01

    explica el 32,0 % de la variabilidad espacio-temporal de las anomalías de las TSM en esta región oceánica y representa la estructura monopolar ecuatorial. Los análisis de correlación simple se llevan a cabo después para explorar los vínculos entre las anomalías de las TSM en Niño 3.4, el modo ENOS del Pacífico, la estructura monopolar ecuatorial del Atlántico y las condiciones de cobertura de nubes imperantes en los Andes septentrionales; 59 % de la variación de las condiciones de cobertura de nubes en el mes de enero sobre la zona de alta montaña seleccionada se explica por las anomalías de las TSM en la región Niño 3.4; 72 % y 71 % de esa variabilidad se explican por las primeras PC (PC1 de las anomalías de las TSM observadas en enero en los cinturones 30°S a 30°N y 15°S a 15°N de la región Índico-Pacífica, respectivamente; por último, el 28 % de esa variabilidad se explica por la PC1 de las anomalías de las TSM observadas en enero en la región 19°S a 29°N del Atlántico tropical. La PC1 de las anomalías de las TSM observadas en enero en el cinturón 30°S a 30°N de la región del Índico-Pacífico exhibe una tendencia estadísticamente significativa durante el período 1942-2007 que muestra más condiciones del tipo El Niño durante los últimos 28 años del período de observación. Ella también muestra un cambio estadísticamente significativo en la media, que coincide con el cambio de régimen ocurrido en el Pacífico tropical hacia 1976. Los análisis sugieren que es probable que haya una disminución de la cobertura neta de nubes en enero en la zona del macizo volcánico Ruiz-Tolima y sus alrededores durante los próximos 50 años. Una disminución en la cantidad de nubes de todo tipo del 6,8 %, relativa al período 1984-2001, es probable que ocurra alrededor del 2050 bajo condiciones "normales". Un evento fuerte de El Niño puede reducir esta cantidad media mensual de nubes desde un valor esperado de 68,7 % hasta un valor promedio

  12. State diagram of U-Al-Si as a basis for analysis of the processes in nuclear fuel compositions based on U(Al, Si)3 and U3Si compounds

    International Nuclear Information System (INIS)

    Chebotarev, N.T.; Konovalov, L.N.; Zhmak, V.A.; Chebotarev, Ya.N.

    1996-01-01

    Results of studies into the Al-UAl 3 -USi 3 -Si of the U-Al-Si ternary system are presented. It is established that phase equilibrium between the intermetallic compound U(Al, Si) 3 and the aluminium-silicon alloys may be presented in form of conodes on the isothermal cross-section of the state diagram. It is shown that the U(Al, Si) 3 intermetallic compound, containing up to 6.5 at.% silicon, interacts both with liquid and solid aluminium with the U(Al, Si) 4 phase formation [ru

  13. Daño al ADN en mujeres expuestas al humo de la leña en Chiapas, México DNA damage in women exposed to firewod fuel smoke , in Chiapas, México

    Directory of Open Access Journals (Sweden)

    Crispín Herrera-Portugal

    2009-12-01

    Full Text Available Actualmente alrededor de la cuarta parte de la población mexicana, entre 25 y 28 millones de habitantes, cocina con leña, Sin embargo, el humo de la leña contiene una amplia gama de sustancias tóxicas, entre ellas el monóxido de carbono (CO cuyo impacto en la salud de la población rural debe ser estudiado. Por esto, el potencial daño al ADN asociado con la exposición a CO de 30 mujeres que cocinaban con leña en Chiapas, México, fue evaluado por el ensayo cometa. Los resultados se compararon con 30 controles comparables en edad y condiciones socioeconómicas, quienes cocinaban con gas licuado de petróleo (GLP. Se obtuvieron muestras de sangre total para medir carboxihemoglobina (COHb y llevar a cabo el ensayo cometa. Se encontró diferencia significativa (PCurrently, about a quarter of the Mexican population, between 25 and 28 million people, cook with firewood. However, wood smoke contains a wide range of toxic substances, including carbon monoxide (CO whose impact on health of the rural population should be studied. Therefore, the potential DNA damage associated with the exposition to CO of 30 women who cooked with wood in Chiapas, Mexico, was assessed using Comet Assay. Results were compared with 30 controls of similar age and socioeconomic status, who cooked with liquefied petroleum gas (LPG. We obtained whole blood samples to measure carboxyhemoglobin (% COHb and perform the comet assay. There was a significant difference (P <0.001 in the percentages of COHb between women who cooked with wood (mean= 6.6% and those who did it with LPG (mean=1.8% being 3.6 times higher in the former compared with the latter. There was a significant difference in comet tail length between the two groups examined (mean 18.5 +/- 4.21 versus 5.97 +/- 1.0 μm, P <0.001 and tail moment (mean 4.55 +/- 1.5 versus 1.5 +/- 0.40, P <0.001. The results of this study strongly suggest that exposure to carbon monoxide and compounds present in wood smoke can cause

  14. CONTRIBUCIONES AL ESTUDIO DE LA FORMACIÓN ACADÉMICA DE LA UNIVERSIDAD DE COSTA RICA: SUS VÍNCULOS CON LOS PROBLEMAS SOCIALES Y LA POBREZA

    Directory of Open Access Journals (Sweden)

    Freddy Esquivel Corella

    2008-01-01

    Full Text Available El presente artículo, resultado parcial de un estudio más amplio, problematiza la importancia que adquieren los problemas sociales (y en especial la pobreza, en la formación académica de la Universidad de Costa Rica. Los datos se derivan de un total de 292 encuestas (mediante un muestreo por conveniencia, que se aplicaron a estudiantes de carreras de las facultades de Educación, Ciencias Sociales, Derecho y Ciencias Económicas, así como a 41 docentes de la misma universidad. Entre los principales hallazgos se encuentra que el tema de los problemas sociales, y en especial la pobreza, se constituye en un eje de interés para los y las estudiantes, aunque en sus planes de estudio parece no ser un contenido relevante. Tal situación puede no ser coherente con los fines y principios que orientan a la Universidad, sin diferencia del campo de conocimiento de cada carrera. A su vez, el contenido expuesto destaca la necesidad de establecer un programa, línea o núcleo de investigación que genere insumos sobre las relaciones entre la educación universitaria y la "cuestión social", como forma de articularse con los currículos de las diferentes carreras.

  15. Contribution to technological development in the reservoirs of hydrocarbons; Contribucion del progreso tecnologico al aumento de las reservas recuperables de hidrocarburos

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-07-01

    In this article, that reflects the intervention of the author in the graduation of the 174 promotion of the Madrid Mining Engineers Technical High School, it is overviewed the last technical advances befallen in the exploration and production stages in the oil and natural gas industry. (Author)

  16. Identification of the zirconium hydrides metallography in zircaloy-2; Contribucion al estudio por metalografia de los hidruros de circonio en Zircaloy-2

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Gonzalez, F

    1968-07-01

    Technique for the Identification of the zirconium hydrides in metallographic specimens have been developed. Microhardness, quantitative estimation and relative orientation of the present hydrides as well as grain size determination of the different Zircaloy-2 tube specimens have also been made. The specimens used were corrosion- tested in water during various periods of time at 300 degree castrating, prior to the metallographic examination. Reference specimens, as received, and heavily hydride specimens in a hydrogen atmosphere at 800 degree centigrees, have been used in the previous stages of the work. No difficulties have been met in this early stage of acquaintanceship with the zirconium hydrides. (Author) 5 refs.

  17. REFERENCIA TEMPORAL EN EL CEREBRO: UNA REVISIÓN CRÍTICA DE LAS CONTRIBUCIONES DE LA NEUROECONOMÍA AL ESTUDIO DE LA ELECCIÓN INTERTEMPORAL

    Directory of Open Access Journals (Sweden)

    René San Martín

    2012-01-01

    Full Text Available Las decisiones humanas suelen implicar costos y beneficios distribuidos en el tiempo. Este artículo revisa el estado actual de la investigación con neuroimagen acerca de la manera en que el cerebro produce decisiones intertemporales. Se propone que mientras resulta poco probable que la neurociencia sea el terreno adecuado para decidir entre los modelos formales propuestos por la economía conductual, los recientes avances en el estudio del cerebro ofrecen la posibilidad de enriquecer dichos modelos incorporando nuevos conocimientos respecto a cómo el cerebro representa magnitudes, atribuye valor, regula conductas orientadas a metas y genera pensamiento prospectivo.

  18. REFERENCIA TEMPORAL EN EL CEREBRO: UNA REVISIÓN CRÍTICA DE LAS CONTRIBUCIONES DE LA NEUROECONOMÍA AL ESTUDIO DE LA ELECCIÓN INTERTEMPORAL

    OpenAIRE

    René San Martín; Pablo Isla; Camilo Melis

    2012-01-01

    Resumen: Las decisiones humanas suelen implicar costos y beneficios distribuidos en el tiempo. Este artículo revisa el estado actual de la investigación con neuroimagen acerca de la manera en que el cerebro produce decisiones intertemporales. Se propone que mientras resulta poco probable que la neurociencia sea el terreno adecuado para decidir entre los modelos formales propuestos por la economía conductual, los recientes avances en el estudio del cerebro ofrecen la posibilidad de enriquecer ...

  19. The role of the soil in the treatment of urban waste water; Contribucion del suelo al proceso de depuracion de aguas residuales urbanas

    Energy Technology Data Exchange (ETDEWEB)

    Cruz Caravaca, M.T. de la; Crespo Alia, A.; Palomar, M.L.; Ramirez Perez, F.

    1995-12-31

    We study the soil influence on the depuration capacity of waste water in De la Torre stream (Northwest of Madrid, Spain) that collects the waste water of Torrelodones municipium. The land orography, the soils filtration capacity, humification and mineralization process and the increase of soils base saturation, are factors which have influenced in this natural depuration process. (Author) 10 refs.

  20. Al2O3 Disk Supported Si3N4 Hydrogen Purification Membrane for Low Temperature Polymer Electrolyte Membrane Fuel Cells

    Directory of Open Access Journals (Sweden)

    Xiaoteng Liu

    2013-12-01

    Full Text Available Reformate gas, a commonly employed fuel for polymer electrolyte membrane fuel cells (PEMFCs, contains carbon monoxide, which poisons Pt-containing anodes in such devices. A novel, low-cost mesoporous Si3N4 selective gas separation material was tested as a hydrogen clean-up membrane to remove CO from simulated feed gas to single-cell PEMFC, employing Nafion as the polymer electrolyte membrane. Polarization and power density measurements and gas chromatography showed a clear effect of separating the CO from the gas mixture; the performance and durability of the fuel cell was thereby significantly improved.

  1. Al2O3 Disk Supported Si3N4 Hydrogen Purification Membrane for Low Temperature Polymer Electrolyte Membrane Fuel Cells.

    Science.gov (United States)

    Liu, Xiaoteng; Christensen, Paul A; Kelly, Stephen M; Rocher, Vincent; Scott, Keith

    2013-12-05

    Reformate gas, a commonly employed fuel for polymer electrolyte membrane fuel cells (PEMFCs), contains carbon monoxide, which poisons Pt-containing anodes in such devices. A novel, low-cost mesoporous Si3N4 selective gas separation material was tested as a hydrogen clean-up membrane to remove CO from simulated feed gas to single-cell PEMFC, employing Nafion as the polymer electrolyte membrane. Polarization and power density measurements and gas chromatography showed a clear effect of separating the CO from the gas mixture; the performance and durability of the fuel cell was thereby significantly improved.

  2. Preparation of a Ni-MgO-Al2O3 catalyst with high activity and resistance to potassium poisoning during direct internal reforming of methane in molten carbonate fuel cells

    Science.gov (United States)

    Jang, Won-Jun; Jung, You-Shick; Shim, Jae-Oh; Roh, Hyun-Seog; Yoon, Wang Lai

    2018-02-01

    Steam reforming of methane (SRM) is conducted using a series of Ni-MgO-Al2O3 catalysts for direct internal reforming (DIR) in molten carbonate fuel cells (MCFCs). Ni-MgO-Al2O3 catalysts are prepared by the homogeneous precipitation method with a variety of MgO loading amounts ranging from 3 to 15 wt%. In addition, each precursor concentrations are systemically changed (Ni: 1.2-4.8 mol L-1; Mg: 0.3-1.2 mol L-1; Al: 0.4-1.6 mol L-1) at the optimized composition (10 wt% MgO). The effects of MgO loading and precursor concentration on the catalytic performance and resistance against poisoning of the catalyst by potassium (K) are investigated. The Ni-MgO-Al2O3 catalyst with 10 wt% MgO and the original precursor concentration (Ni: 1.2 mol L-1; Mg: 0.3 mol L-1; Al: 0.4 mol L-1) exhibits the highest CH4 conversion and resistance against K poisoning even at the extremely high gas space velocity (GHSV) of 1,512,000 h-1. Excellent SRM performance of the Ni-MgO-Al2O3 catalyst is attributed to strong metal (Ni) to alumina support interaction (SMSI) when magnesium oxide (MgO) is co-precipitated with the Ni-Al2O3. The enhanced interaction of the Ni with MgO-Al2O3 support is found to protect the active Ni species against K poisoning.

  3. Integrated information system MBS as a basis for fuel management in conventional power stations; Integriertes Informationssystem MBS als Basis fuer das Brennstoffmanagement in konventionellen Kraftwerken

    Energy Technology Data Exchange (ETDEWEB)

    Sasko, P.; Lindemann, H.; Kern, H.

    2000-07-01

    The fuel cost is a key factor in fossil-fuel power stations, and optimisation of fuel use is an urgent task. Modul Brennstoffe MBS supports all processes relevant for fuel supply and waste management, i.e. projecting, acquisition, optimisation of operation, billing, and evaluation. [German] Die gegenwaertige Situation in der Energiewirtschaft und im liberalisierten Energiemarkt hat zu einem nachhaltigen Kostendruck auf der Seite der Erzeugung gefuehrt. Die Brennstoffkosten in den fossil befeuerten Kraftwerken stellen eine wesentliche Komponente der Erzeugungskosten dar. Vor diesem Hintergrund hat die Optimierung des Brennstoffeinsatzes eine grundsaetzliche Bedeutung gewonnen. Modul Brennstoffe MBS unterstuetzt alle fuer die Brennstoffversorgung und fuer die Entsorgung von konventionellen Kraftwerken relevanten Geschaeftsprozesse. Es umfasst die Geschaeftsvorgaenge Planung, Beschaffung, Einsatzoptimierung, Abrechnung und Auswertung. Die Geschaeftsprozesse sind informationstechnisch im Modul Brennstoffe in einem integrierten System abgebildet. (orig.)

  4. Luis Agustín García Moreno, Esther Sánchez Medina (eds.), Del Nilo al Guadalquivir. II Estudios sobre las fuentes de la conqui

    OpenAIRE

    Meouak, Mohamed

    2015-01-01

    El libro que el lector tiene entre sus manos constituye una seria apuesta por sacar definitivamente de la obscuridad los estudios dedicados al Mediterráneo centro-occidental y el norte de África entre el final de la Antigüedad y la alta Edad Media dentro del ámbito académico español. Entre mundos distintos y culturas en contacto, dicho volumen ofrece contribuciones científicas de calidad, basadas en investigaciones relativas al norte de África que permiten aumentar y matizar considerablemente...

  5. ¿Siento, existo y luego? pienso?: contribuciones para la construcción del conocimiento científico

    OpenAIRE

    Perlo, Claudia; LOPEZ ROMORINI, Verónica

    2014-01-01

    Se trata de un trabajo teórico-metodológico, producto de más de 20 años de trabajos de investigación empírica en educación. El mismo presenta una reflexión onto-epistemológica sobre la construcción del conocimiento científico. En la introducción se desarrollan conceptos en torno al conocer y al vivir, sustentados en la teoría biológica del conocimiento. Luego se aborda un desarrollo histórico sobre el concepto de ...

  6. Las políticas sociales de dependencia en España: contribuciones y consecuencias para los ancianos y sus cuidadores informales

    Directory of Open Access Journals (Sweden)

    Bibiana Escuredo

    2007-01-01

    Full Text Available Se presenta la evolución de la protección social de la dependencia en España desde la década de los noventa hasta el momento actual y se plantean las consecuencias de la falta de acuerdo político respecto a las medidas a implementar. Se analizan los elementos en los que se basan las políticas de dependencia, resaltando sus aspectos positivos y negativos, así como las consecuencias para los ancianos y sus cuidadores informales. También se pone de manifiesto cómo, ante la posibilidad de quiebra del papel de la familia en el cuidado de los dependientes, se están implementando políticas que tienen como objetivo reforzar el rol cuidador de la familia y que se enmarcan dentro de la denominada "Conciliación de la Vida Familiar y Laboral". Estas políticas, más allá de sus contribuciones positivas, implican también importantes costes personales y de oportunidad para los cuidadores informales.

  7. Synthesis and characterization of sulfonate polystyrene-lignosulfonate-alumina (SPS-LS-Al{sub 2}O{sub 3}) polyblends as electrolyte membranes for fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Gonggo, Siang Tandi, E-mail: standigonggo@yahoo.com [Chemistry Research Groups, Faculty of Teacher Training and Educational Sciences, Tadulako University (Indonesia)

    2015-09-30

    The new type of electrolyte membrane materials has been prepared by blend sulfonated polystyrene (SPS), lignosulfonate (LS), and alumina (SPS-LS-Al{sub 2}O{sub 3}) by casting polymer solution. The resulting polymer electrolyte membranes were then characterized by functional groups analysis, mechanical properties, water uptake, ion exchange capacity, and proton conductivity. SPS-LS-Al{sub 2}O{sub 3} membranes with alumina composition various have been proven qualitatively by analysis of functional groups. Increasing the Al{sub 2}O{sub 3} ratio resulted in higher ion exchange capacity (IEC), mechanical strength and proton conductivity, but water uptake decreased. The SPS-LS-Al{sub 2}O{sub 3} blend showed higher proton conductivity than Nafion 117.

  8. Rambutan-like CNT-Al2O3 scaffolds for high-performance cathode catalyst layers of polymer electrolyte fuel cells

    Science.gov (United States)

    Chang, KwangHyun; Cho, Seonghun; Lim, Eun Ja; Park, Seok-Hee; Yim, Sung-Dae

    2018-03-01

    Rambutan-like CNT-Al2O3 scaffolds are introduced as a potential candidate for CNT-based catalyst supports to overcome the CNT issues, such as the easy bundling in catalyst ink and the poor pore structure of the CNT-based catalyst layers, and to achieve high MEA performance in PEFCs. Non-porous α-phase Al2O3 balls are introduced to enable the growth of multiwalled CNTs, and Pt nanoparticles are loaded onto the CNT surfaces. In a half-cell, the Pt/CNT-Al2O3 catalyst shows much higher durability than those of a commercial Pt/C catalyst even though it shows lower oxygen reduction reaction (ORR) activity than Pt/C. After using the decal process for MEA formation, the Pt/CNT-Al2O3 shows comparable initial performance characteristics to Pt/C, overcoming the lower ORR activity, mainly due to the facile oxygen transport in the cathode catalyst layers fabricated with the CNT-Al2O3 scaffolds. The Pt/CNT-Al2O3 also exhibits much higher durability against carbon corrosion than Pt/C owing to the durable characteristics of CNTs. Systematic analysis of single cell performance for both initial and after degradation is provided to understand the origin of the high initial performance and durable behavior of Pt/CNT-Al2O3-based catalyst layers. This will provide insights into the design of electrocatalysts for high-performance MEAs in PEFCs.

  9. Corrosion of non-irradiated UAl{sub x}-Al fuel in the presence of clay pore solution. A quantitative XRD secondary phase analysis applying the DDM method

    Energy Technology Data Exchange (ETDEWEB)

    Neumann, Andreas [Halle-Wittenberg Univ. (Germany). Dept. of Mineralogy and Geochemistry; RWTH Aachen Univ. (Germany). Inst. of Crystallography; Klinkenberg, Martina; Curtius, Hildegard [Forschungszentrum Juelich GmbH (Germany). Inst. of Energy and Climate Research, IEK-6 Nuclear Waste Management

    2017-04-01

    Corrosion experiments with non-irradiated metallic UAl{sub x}-Al research reactor fuel elements were carried out in autoclaves to identify and quantify the corrosion products. Such compounds, considering the long-term safety assessment of final repositories, can interact with the released inventory and this constitutes a sink for radionuclide migration in formation waters. Therefore, the metallic fuel sample was subjected to clay pore solution to investigate its process of disintegration by analyzing the resulting products and the remnants, i.e. the secondary phases. Due to the fast corrosion rate a full sample disintegration was observed within the experimental period of 1 year at 90 C. The obtained solids were subdivided into different grain size fractions and prepared for analysis. The elemental analysis of the suspension showed that, uranium and aluminum are concentrated in the solids, whereas iron was mainly dissolved. Non-ambient X-ray diffraction (XRD) combined with the derivative difference minimization (DDM) method was applied for the qualitative and quantitative phase analysis (QPA) of the secondary phases. Gypsum and hemihydrate (bassanite), residues of non-corroded nuclear fuel, hematite, and goethite were identified. The quantitative phase analysis showed that goethite is the major crystalline phase. The amorphous content exceeded 80 wt% and hosted the uranium. All other compounds were present to a minor content. The obtained results by XRD were well supported by complementary scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) analysis.

  10. From biomass to fuels: hydrotreating of oxygen-containing feeds on a CoMo/Al{sub 2}O{sub 3} hydrodesulfurization catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Viljava, T.-R.

    2001-07-01

    Biomass is a renewable alternative to fossil raw materials in the production of liquid fuels and chemicals. Liquefied biomass contains an abundance of oxygen-containing molecules that need to be removed to improve the stability of the liquids. A hydrotreating process, hydrodeoxygenation (HDO), is used for the purpose. Hydrodeoxygenation is similar to the hydrodesulfurization (HDS) process used in oil refining, relying upon a presulfided CoMo/{gamma}-Al{sub 2}O{sub 2}; catalyst. The stability of the sulfided catalyst is critical in HDO because biocrudes usually do not contain the sulfur compounds needed to maintain the sulfidation of the catalyst. The aim of this work was to examine the role of sulfur in maintaining the activity of the HDO catalyst. Sulfur was introduced as an organic sulfur-containing co-reactant or as a sulfur substituent in an oxygen-containing reactant molecule as a way of simulating mixed feeds composed of biocrudes and conventional crudes, or it was introduced as a low molecular weight sulfiding agent. In addition, the stability of the sulfided catalyst against changes in the feed composition was studied to find out whether the activity of the catalyst could be maintained by carrying out HDO alternately with HDS. Simultaneous HDO and HDS was studied in a batch reactor with model compounds having a sulfur-containing (inercapto or inethylmercapto) and an oxygen-containing (hydroxyl or inethoxy) substituent in the same molecule, and with binary mixtures of mono-substituted benzene compounds. In both cases, the reactions of the oxygencontaining substituents were strongly suppressed as long as a sulfur-containing functionality was present. HDS reactions of inercapto and inethylinercapto groups were either enhanced or retarded in the presence of oxygen-containing functionality. HDS was enhanced when the oxygen-containing substituent was located in Para-position to the sulfur substituent thereby increasing the electronegativity of the sulfur atom and

  11. Kinetic parameters of a material test research reactor fueled with various low enriched uranium dispersion fuels

    International Nuclear Information System (INIS)

    Muhammad, Farhan; Majid, Asad

    2009-01-01

    The effects of using different low enriched uranium fuels, having same uranium density, on the kinetic parameters of a material test research reactor were studied. For this purpose, the original aluminide fuel (UAl x -Al) containing 4.40 gU/cm 3 of an MTR was replaced with silicide (U 3 Si-Al and U 3 Si 2 -Al) and oxide (U 3 O 8 -Al) dispersion fuels having the same uranium density as of the original fuel. Simulations were carried out to calculate prompt neutron generation time, effective delayed-neutron fraction, core excess reactivity and neutron flux spectrum. Nuclear reactor analysis codes including WIMS-D4 and CITATION were used to carry out these calculations. It was observed that both the silicide fuels had the same prompt neutron generation time 0.02% more than that of the original aluminide fuel, while the oxide fuel had a prompt neutron generation time 0.05% less than that of the original aluminide fuel. The effective delayed-neutron fraction decreased for all the fuels; the decrease was maximum at 0.06% for U 3 Si 2 -Al followed by 0.03% for U 3 Si-Al, and 0.01% for U 3 O 8 -Al fuel. The U 3 O 8 -Al fueled reactor gave the maximum ρ excess at BOL which was 21.67% more than the original fuel followed by U 3 Si-Al which was 2.55% more, while that of U 3 Si 2 -Al was 2.50% more than the original UAl x -Al fuel. The neutron flux of all the fuels was more thermalized, than in the original fuel, in the active fuel region of the core. The thermalization was maximum for U 3 O 8 -Al followed by U 3 Si-Al and then U 3 Si 2 -Al fuel.

  12. Parameter Studies on High-Velocity Oxy-Fuel Spraying of CoNiCrAlY Coatings Used in the Aeronautical Industry

    Directory of Open Access Journals (Sweden)

    J. A. Cabral-Miramontes

    2014-01-01

    Full Text Available The thermal spraying process is a surface treatment which does not adversely affect the base metal on which it is performed. The coatings obtained by HVOF thermal spray are employed in aeronautics, aerospace, and power generation industries. Alloys and coatings designed to resist oxidizing environments at high temperatures should be able to develop a surface oxide layer, which is thermodynamically stable, slowly growing, and adherent. MCrAlY type (M = Co, Ni or combination of both coatings are used in wear and corrosion applications but also provide protection against high temperature oxidation and corrosion attack in molten salts. In this investigation, CoNiCrAlY coatings were produced employing a HVOF DJH 2700 gun. The work presented here focuses on the influences of process parameters of a gas-drive HVOF system on the microstructure, adherence, wear, and oxygen content of CoNiCrAlY. The results showed that spray distance significantly affects the properties of CoNiCrAlY coatings.

  13. Contribuciones de la biblioteca universitaria a la internacionalización del campus: análisis sistemático de la literatura

    Directory of Open Access Journals (Sweden)

    Nancy Sánchez-Tarragó

    Full Text Available RESUMEN Los procesos de internacionalización universitaria constituyen respuesta adaptativa a un contexto mundial signado por la globalización, que implica, grosso modo, mayor interrelación política, económica y social entre países y regiones. En este contexto, es válido preguntarse cuál es el papel y las contribuciones de la biblioteca universitaria en los procesos de internacionalización del campus, teniendo en cuenta que, históricamente, su razón de ser ha sido servir de apoyo a la universidad en el desarrollo de sus funciones. Para encontrar respuestas se realizó una revisión sistemática de la literatura publicada en Ciencia de la información entre el 2005 y el 2015 y un análisis bibliométrico de esa producción científica. Se constató un crecimiento continuo de la investigación publicada, liderada por bibliotecarios de Estados Unidos, China y Canadá, que abordan diferentes aristas del trabajo bibliotecario que apoyan tanto la educación transnacional como la internacionalización ‘en casa’: servicios bibliotecarios para apoyar estudiantes y programas en el exterior, programas de alfabetización informacional, estudios sobre la influencia de las diferencias culturales y lingüísticas en la comunicación y los servicios, desarrollo de colecciones, entre otras. Se identificaron recomendaciones para la práctica bibliotecaria relacionadas con estrategias administrativas, de servicios, infraestructura, formación e investigación.

  14. Synthesis and electrochemical characterization of Ti{sub x}Ta{sub y}Al{sub z}N{sub 1-δ}O{sub γ} for fuel cell catalyst supports

    Energy Technology Data Exchange (ETDEWEB)

    Wakabayashi, Ryo H.; Abruña, Héctor D., E-mail: hda1@cornell.edu; DiSalvo, Francis J., E-mail: fjd3@cornell.edu

    2017-02-15

    Quinary Ti{sub x}Ta{sub y}Al{sub z}N{sub 1-δ}O{sub γ} of various compositions have been prepared by a co-precipitation method followed by ammonolysis. The nitride samples were examined as potential catalyst supports in polymer electrolyte membrane fuel cells. The nitride products crystallized in the rock salt (NaCl) structure over a wide range of compositions. The addition of Ta and Al was highly beneficial towards improving the chemical and electrochemical stability of TiN, without a significant loss of electrical conductivity. Platinum particles were successfully deposited on the (oxy)nitride samples, and the composite samples at some compositions were found to be comparable to Pt/carbon in their stability and catalytic activity even without optimizing the Pt deposition and dispersion processes. - Graphical abstract: The effect of additions of Ta and Al into TiN structure. Shifts the lattice constant, and increases its chemical stability in acidic environment.

  15. Cold-starting portable microenergy system. Autonomous fuel cell system using sodium borohydride as an energy source; Kaltstartfaehiges portables Mikroenergiesystem. Autarkes BZ-System mit Natriumborhydrid als Energietraeger

    Energy Technology Data Exchange (ETDEWEB)

    Groos, Ulf; Koch, Wolfgang [Fraunhofer-Institut fuer Solare Energiesysteme (ISE), Freiburg im Breisgau (Germany)

    2012-10-15

    A project consortium led by Fraunhofer-Institut fuer Solare Energiesysteme ISE developed an autonomous micro energy system (AMES) with an output of 100 W{sub el} as a charging station for applications in emergency medicine. The system is designed for a wide temperature range of -15 to +50 degC during startup, operation, and shutoff. The cold starting fuel cell system is in accordance with current standards and is suited for serial production. It can be operated with common hydrogen stores, e.g. gas flasks or metal hydrides, or else with a specially developed hydrogen generator based on sodium borohydride. (orig.)

  16. Fuel effect on solution combustion synthesis of Co(Cr,Al)2O4 pigments; Efecto del combustible en la síntesis de pigmentos Co(Cr,Al)2O4 por combustión de una disolución

    Energy Technology Data Exchange (ETDEWEB)

    Gilabert, J.; Palacios, M.D.; Sanz, V.; Mestre, S.

    2017-11-01

    The fuel effect on the synthesis of a ceramic pigment with a composition CoCr2−2ΨAl2ΨO4 (0≤Ψ≤1) by means of solution combustion synthesis process (SCS) has been studied. Three different fuels were selected to carry out the synthesis (urea, glycine and hexamethylentetramine (HMT)). Highly foamy pigments with very low density were obtained. Fd-3m spinel-type structure was obtained in all the experiments. Nevertheless, crystallinity and crystallite size of the spinels show significant differences with composition and fuel. The use of glycine along with the chromium-richest composition favours ion rearrangement to obtain the most ordered structure. Lattice parameter does not seem to be affected by fuel, although it evolves with Ψ according to Vegard's law. Colouring power in a transparent glaze shows important variations with composition. On the other hand, fuel effect presents a rather low influence since practically the same shades are obtained. However, it exerts certain effect on luminosity (L*). [Spanish] Se ha estudiado el efecto del combustible en la síntesis de pigmentos cerámicos tipo CoCr2-2ΨAl2ΨO4 (0≤Ψ≤1), obtenidos mediante síntesis por combustión de una disolución. Se seleccionaron 3 tipos de combustible diferentes: urea, glicina y hexametilentetramina. Todos los pigmentos obtenidos presentaron una textura altamente esponjosa y con muy baja densidad. Las estructuras cristalinas desarrolladas en todos los casos fueron tipo espinela Fd-3m. Sin embargo, tanto la cristalinidad como el tamaño de cristalito presentaron diferencias significativas dependiendo de la composición y del combustible utilizado. El uso de glicina, junto con las composiciones más ricas en cromo, favorece la reorganización de los iones para obtener estructuras más ordenadas y con mayor cristalinidad. El parámetro de red no parece verse afectado por el combustible, aunque sí evoluciona con Ψ de acuerdo con la Ley de Vegard. El poder colorante desarrollado

  17. Novel Oxidative Desulfurization of a Model Fuel with H2O2 Catalyzed by AlPMo12O40 under Phase Transfer Catalyst-Free Conditions

    OpenAIRE

    José da Silva, Márcio; Faria dos Santos, Lidiane

    2013-01-01

    A novel process was developed for oxidative desulfurization (ODS) in the absence of a phase transfer catalyst (PTC) using only Keggin heteropolyacids and their aluminum salts as catalysts. Reactions were performed in biphasic mixtures of isooctane/acetonitrile, with dibenzothiophene (DBT) as a model sulfur compound and hydrogen peroxide as the oxidant. Remarkably, only the AlPMo12O40-catalyzed reactions resulted in complete oxidation of DBT into DBT sulfone, which was totally extracted by ace...

  18. Upgrading of the liquid fuel from fast pyrolysis of biomass over MoNi/{gamma}-Al{sub 2}O{sub 3} catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Ying; Liang, Wei [Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou, Guangdong (China); Graduate School of the Chinese Academy of Sciences, Beijing (China); Wang, Tiejun; Ma, Longlong; Zhang, Qi [Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou, Guangdong (China); Key Laboratory of Renewable Energy and Gas Hydrate, Chinese Academy of Sciences, Guangzhou, Guangdong (China)

    2010-09-15

    The hydrotreatment of bio-oil, which obtained from fast pyrolysis of pine sawdust, was investigated over MoNi/{gamma}-Al{sub 2}O{sub 3} catalyst under mild conditions (373 K, 3 MPa hydrogen pressure). Acetic acid was taken as a model compound to investigate the effects of Mo promoter contents and reducing temperatures of catalysts on the catalysts activity under the condition of 473 K and 3 MPa hydrogen pressure. X-ray diffraction and temperature programmed reduction showed that the addition of Mo promoter benefited the uniformity of nickel species and inhibited the formation of NiAl{sub 2}O{sub 4} spinel in the catalysts. The GC spectrum of liquid products showed the mechanism of the model reaction. The maximum conversion of acetic acid (33.20%) was attained over 0.06MoNi/{gamma}-Al{sub 2}O{sub 3} catalysts being reduced at 873 K. This catalyst was chosen for the upgrading of raw bio-oil. After the upgrading process, the pH value of the bio-oil increased from 2.33 to 2.77. The water content increased from 35.52 wt.% to 41.55 wt.% and the gross calorific value increased from 13.96 MJ/kg to 14.17 MJ/kg. The hydrogen content in the bio-oil increased from 6.25 wt.% to 6.95 wt.%. The product properties of the upgraded bio-oil, particularly the hydrogen content and the acidity were considerably improved. The results of gas chromatography-mass spectrometry analysis showed that both hydrotreatment and esterification had happened over 0.06MoNi/{gamma}-Al{sub 2}O{sub 3} (873) catalyst during the upgrading process. (author)

  19. Feasibility of biomass as a fuel for electric power generation in the Netherlands. Haalbaarheid van biomassa als brandstof voor elektriciteitsproduktie in Nederland

    Energy Technology Data Exchange (ETDEWEB)

    Bestebroer, S I [KEMA Milieu Services, Arnhem (Netherlands)

    1993-01-01

    Based on data from a study of the Netherlands Agency for Energy and the Environment (NOVEM) on the feasibility of biomass for the Dutch energy economy and on data from a literature study, a sensitivity analysis was carried out to determine the dependency of the energetic efficiency and the cost price on the starting points of the NOVEM study.Conclusions are drawn regarding the maximal capacity on the basis of biomass. Also attention is paid to the height of the carbon levy on the use of fossil fuels, by which the price of bio-electricity can be made competitive. It appears that electric power generation from biomass by means of an integrated biomass gasification combined cycle (IBGCC) is energetic efficient for the considered energy crops. However, the carbon levy on the use of fossil fuels must be 100% to make bio-energy competitive. It also must be taken into consideration that, next to the favourable characteristic of renewability, bio-energy bears a number of potential environmental loads

  20. Contribuciones de la producción en traspatio a los grupos domésticos campesinos

    Directory of Open Access Journals (Sweden)

    Floriberto González Ortiz

    2014-01-01

    Full Text Available El traspatio es considerado un agroecosiste - ma y ha sido incluido en programas guber - namentales con el fin de mejorar la seguri - dad alimentaria y contribuir a la reducción de la pobreza. Los objetivos fueron: analizar las características de los componentes es - tructurales del traspatio y precisar la contri - bución vegetal y animal a la mejora de la ali - mentación, salud e ingreso. Se utilizó la encuesta; la muestra fue de 63 Grupos Do - mésticos Campesinos ( GDC de un total de 444. Los resultados muestran que el traspa - tio está integrado por cuatro componentes: agrícola, pecuario, agua e infraestructura y equipo. Las características de los componen - tes permiten que los GDC cultiven diversas especies vegetales y críen varias especies ani - males. La producción vegetal y animal con - tribuye a la alimentación, la salud y al ingre - so familiar.

  1. Contribuciones del factor general y de los factores específicos en la relación entre inteligencia y rendimiento escolar Contributions of the general and the specific factors for the intelligence and school achievement relationship

    Directory of Open Access Journals (Sweden)

    Leandro S. Almeida

    2009-11-01

    Full Text Available

    En este artículo se pretende analizar en qué medida, factores más específicos de la cognición, asociados a contenido verbal, numérico o figurativo, complementan un factor más general de raciocinio en la predicción del rendimiento escolar de los alumnos, al inicio y final de la adolescencia. A una muestra de estudiantes portugueses (n=4.899 entre el 5º y el 12º año de escolaridad, se le aplicó una Batería de Pruebas de Raciocinio en sus tres versiones. El rendimiento escolar de los alumnos se estimó en base a sus clasificaciones en Lengua Portuguesa y Matemáticas. El modelo de ecuaciones estructurales mostró un mayor impacto del factor general (inteligencia fluida-inductiva asociado a todas las pruebas de la BPR en la predicción del rendimiento escolar, observándose que esa significación disminuía progresivamente a lo largo de la escolaridad. Por otro lado, elementos específicos de cada prueba entraron en un segundo modelo, especialmente, en el grupo de los alumnos más jóvenes (5º y 6º año. Entre el 7º y el 9º año las contribuciones específicas de las pruebas se refieren, sobre todo, a la prueba de raciocinio verbal (la prueba de raciocinio numérico aparece también en el 9º año. Así, aún reconociendo la relevancia del factor g en la explicación del rendimiento académico, componentes cognitivos específicos pueden también contribuir para asociar inteligencia y realización académica.

    Palabras clave: Inteligencia, factor g, factores específicos, Gf-Gc, rendimiento académico.

    This paper aims to analyse the extent to which factors more specific cognition, content associated with verbal, numerical or figurative, complement a reasoning general factor in predicting students´ academic achievement at the beginning and the end of adolescence. Taking a Portuguese students sample (n=4,899 from 5th to 12th grades, the reasoning tests battery (BPR – Bateria de Provas de Raciocínio was administrated

  2. Tunable thermodynamic activity of La x Sr1-x Mn y Al1-y O3-δ (0 ≤ x ≤ 1, 0 ≤ y ≤ 1) perovskites for solar thermochemical fuel synthesis.

    Science.gov (United States)

    Ezbiri, M; Takacs, M; Theiler, D; Michalsky, R; Steinfeld, A

    2017-02-28

    Nonstoichiometric metal oxides with variable valence are attractive redox materials for thermochemical and electrochemical fuel processing. To guide the design of advanced redox materials for solar-driven splitting of CO 2 and/or H 2 O to produce CO and/or H 2 (syngas), we investigate the equilibrium thermodynamics of the La x Sr 1- x Mn y Al 1- y O 3- δ perovskite family (0 ≤ x ≤ 1, 0 ≤ y ≤ 1) and La 0.6 Ca 0.4 Mn 0.8 Al 0.2 O 3- δ , and compare them to those of CeO 2 as the baseline. Oxygen nonstoichiometry measurements from 1573 to 1773 K and from 0.206 to 180 mbar O 2 show a tunable reduction extent, increasing with increasing Sr content. Maximal nonstoichiometry of 0.32 is established with La 0.2 Sr 0.8 Mn 0.8 Al 0.2 O 3- δ at 1773 K and 2.37 mbar O 2 . As a trend, we find that oxygen capacities are most sensitive to the A-cation composition. Partial molar enthalpy, entropy and Gibbs free energy changes for oxide reduction are extracted from the experimental data using defect models for Mn 4+ /Mn 3+ and Mn 3+ /Mn 2+ redox couples. We find that perovskites exhibit typically decreasing enthalpy changes with increasing nonstoichiometries. This desirable characteristic is most pronounced by La 0.6 Sr 0.4 Mn 0.4 Al 0.6 O 3- δ , rendering it attractive for CO 2 and H 2 O splitting. Generally, perovskites show lower enthalpy and entropy changes than ceria, resulting in more favorable reduction but less favorable oxidation equilibria. The energy penalties due to larger temperature swings and excess oxidants are discussed in particular. Using electronic structure theory, we conclude with a practical methodology estimating thermodynamic activity to rationally design perovskites with variable stoichiometry and valence.

  3. Fuel Exhaling Fuel Cell.

    Science.gov (United States)

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

    2018-01-18

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

  4. Liberalismo, fascismo y clase obrera: algunas contribuciones recientes a la historia comparada de la Europa de entreguerras

    Directory of Open Access Journals (Sweden)

    Julián CASANOVA RUIZ

    2010-02-01

    Full Text Available RESUMEN: En Liberalism, Fascism or Social Democracy, un amplio análisis del desarrollo político de Europa occidental desde finales del siglo XIX hasta la Segunda Guerra Mundial, Gregory M. Luebbert sostiene que la evolución que condujo a la mayoría de las naciones europeas occidentales a la democracia liberal, a la social democracia y al fascismo puede explicarse por el conjunto de alianzas de clases presente en cada una de esas sociedades. La primera parte del artículo presenta el argumento estructuralista de Luebbert y su búsqueda de las variables y conexiones causales que hagan comprensible las diferentes experiencias nacionales. En la segunda parte se intenta comprobar la validez de su argumento a la luz de otras investigaciones recientes. Se trata, en definitiva, de explicar las peculiaridades históricas y estructurales que distinguen los casos de ruptura con el liberalismo de aquéllos que permanecieron en la vía democrática.ABSTRACT:In Liberalism, Fascism or Social Democracy, a comprehensive analysis of the political development of Western Europe from the late nineteenth- century to the eve of World War II, Gregory M. Luebbert contends that the evolution of most Western European nations into liberal democracies, social democracies, or fascist regimes was attributable to a set of social class alliances within individual nations. The first part of this paper presents Luebbert' structuralist argument and his search for a handful of «master variables» and causal connexions that would explain the particular evolution of each nation. In the second part the paper attempts to evaluate the validity of this argument from other recent research. It seeks, therefore, to explain what structural and historical features distinguish the breakdown cases from those that remained democratic.

  5. Efficient oxidative desulfurization (ODS) of model fuel with H{sub 2}O{sub 2} catalyzed by MoO{sub 3}/{gamma}-Al{sub 2}O{sub 3} under mild and solvent free conditions

    Energy Technology Data Exchange (ETDEWEB)

    Jia, Yuhua; Li, Gang; Ning, Guiling [State Key Laboratory of Fine Chemicals, School of Chemical Engineering, Dalian University of Technology (China)

    2011-01-15

    An efficient process to remove organic sulfur compounds from model fuel has been explored. Dibenzothiophene (DBT) and 4, 6-dimethyldibenzothiophene (4, 6-DMDBT) can be completely oxidized into their corresponding sulfones by H{sub 2}O{sub 2} over 14 wt.% MoO{sub 3}/{gamma}-Al{sub 2}O{sub 3} catalyst under mild conditions in 15 min. The effects of solvent, initial sulfide concentration, loading of MoO{sub 3} and amount of catalyst on oxidative removal of DBT were studied. The employments of solvents have decreased the reaction rate of DBT, which can be attributed to the competitive adsorption between the sulfide and solvent. The oxidative reactivity increases in the order of thiophene (Th) < benzothiophene (BT) < DBT < 4, 6-DMDBT. The catalyst can be regenerated by methanol washing at 333 K. (author)

  6. ALS Association

    Science.gov (United States)

    ... toward a world without ALS! Walk to Defeat ALS® Walk to Defeat ALS® draws people of all ... We need your help. I Will Advocate National ALS Registry The National ALS Registry is a congressionally ...

  7. Aproximaciones teóricas a la relación naturaleza - cultura: algunas contribuciones entre 1980 – 2004

    Directory of Open Access Journals (Sweden)

    Ricardo Gómez

    2009-10-01

    Full Text Available El objetivo del presente artículo es mostrar algunas de las críticas más importantes dadas en el debate actual entre naturaleza y cultura. Busca reivindicar nuevos paradigmas de las ciencias dentro de la problemática del agotamiento de los recursos naturales del hogar que habitamos, la tierra, y el papel que juegan las comunidades locales contra el discurso predador del capitalismo global, a partir de su existencia cultural y social. Este trabajo se divide en tres partes que proponen por analogía, un símil entre los momentos de cambio de la noche al amanecer de un nuevo día; de la misma forma en que podríamos pasar de paradigmas “clásicos”, a procesos sociales recientes que incluyen los conocimientos locales. La primera, llamada “la noche”, expone brevísimamente los planteamientos más comunes que el capitalismo y las corrientes positivistas de la ciencia, mantienen frente a la naturaleza. La segunda, “el amanecer”, es una de las partes más importantes del presente escrito, ya que realiza una crítica a la oscuridad de la noche, a los planteamientos del capitalismo global desde el marxismo, el post-estructuralismo y el género. La tercera, “nuevo día”, concluye que a la luz de estas nuevas perspectivas de análisis podemos comprender mejor la relación entre los seres humanos y la tierra. Estos nuevos conocimientos políticos, culturales, ambientales y globales, desde el centro y la periferia, están atravesados por vínculos de poder que proponen una posición integradora entre conceptos aparentemente contradictorios y suponen susuperación a partir de la conciencia que autogeneran buscando orientar el tema político hacia estos nuevos conocimientos dentro de una agenda global.

  8. Determination of the agricultural and process-related boundary conditions for the use of rapeseed oil and its refinery products as motor fuel. Final report; Ermittlung der landwirtschaftlichen, prozesstechnischen und verfahrenstechnischen Rahmenbedingungen fuer die Verwendung von Rapsoel und seiner Umwandlungsprodukte als Kraftstoff. Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Schliephake, D; Hacker, C M

    1994-11-01

    The use of rapeseed oil as a motor fuel is viewed from various angles: Production aspects; environmental aspects; marketing aspects in agriculture; business management aspects in the Federal Republic of Germany; production and refining of rapeseed oil; use of rapeseed oil methyl ester as diesel fuel and in mineral oil processing plants; engine performance. (orig./SR) [Deutsch] In dem vorliegenden Bericht wird der Einsatz von Rapsoel als Kraftstoff aus verschiedenen Blickwinkeln betrachtet: Produktionsaspekte, Umweltaspekte, marktwirtschaftliche Aspekte in der Landwirtschaft; betriebswirtschaftliche Aspekte in der Bundesrepublik Deutschland; Herstellung und Raffination von Rapsoel; Einsatz von Rapsoelmethylester als Dieselkraftstoff und in Anlagen der Mineraloelverarbeitung; Motortechnische Untersuchungsergebnisse. (orig./SR)

  9. Familial ALS

    Science.gov (United States)

    Boylan, Kevin

    2015-01-01

    Synopsis Genes linked to ALS susceptibility are being identified at an increasing rate owing to advances in molecular genetic technology. Genetic mechanisms in ALS pathogenesis appear to exert major effects in ~10% of patients, but genetic factors at some level may be important components of disease risk in most ALS patients. Identification of gene variants associated with ALS has informed concepts of the pathogenesis of ALS, aided the identification of therapeutic targets, facilitated research to develop new ALS biomarkers, and supported the establishment of clinical diagnostic tests for ALS-linked genes. Translation of this knowledge to ALS therapy development is ongoing. PMID:26515623

  10. INTERACCIONES Y CONTRIBUCIONES. FORMA DE PARTICIPACIÓN DE ESTUDIANTES DE QUINTO GRADO EN AMBIENTES DE MODELACIÓN MATEMÁTICA

    Directory of Open Access Journals (Sweden)

    Mónica Marcela Parra-Zapata

    2016-01-01

    Full Text Available La literatura internacional llama la atención sobre la importancia de promover espacios de participación en ambientes de aprendizaje de la matemática escolar; sin embargo la cantidad de investigaciones que se ocupe de estudiarla en ambientes de modelación en educación primaria es insuficiente. En este sentido, se desarrolló una investigación en la cual se indagó las maneras cómo un grupo de estudiantes participó en ambientes que incluían algunas características de la perspectiva socio-crítica de la modelación matemática, entre ellas, la posibilidad de negociación, de discusión y el cuestionamiento del rol de las matemáticas en los fenómenos y en la sociedad. La investigación fue cualitativa y en ella participaron 27 estudiantes de quinto grado (9-11 años de una institución educativa de la Ciudad de Medellín. Para analizar la participación de los estudiantes se utilizaron entrevistas, observación participante y documentos. Se centró la atención en las manifestaciones orales y escritas, las acciones y las explicaciones de los estudiantes en dos (2 episodios ocurridos en ambientes de modelación matemática. Los resultados permitieron identificar que cuando los estudiantes se involucran en ambientes que promueven su participación, se comprometen con la descripción e interpretación de las situaciones a estudiar, la matematización de relaciones propias de la situación y la interpretación y el análisis de las soluciones propuestas. En consecuencia, se logró analizar y caracterizar las interacciones y las contribuciones como una forma de participación. Los resultados ofrecen una comprensión de la participación de los estudiantes en ambientes de modelación matemática, y por tanto, algunas nociones y aportes teóricos en Educación Matemática.

  11. Upgrading of liquid fuel from the vacuum pyrolysis of biomass over the Mo-Ni/{gamma}-Al{sub 2}O{sub 3} catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Ying; Wang, Lu [Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou Guangdong 510640 (China); Key Laboratory of Renewable Energy and Gas Hydrate, CAS, Guangzhou Guangdong 510640 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100039 (China); Wang, Tiejun; Ma, Longlong; Zhang, Qi [Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou Guangdong 510640 (China); Key Laboratory of Renewable Energy and Gas Hydrate, CAS, Guangzhou Guangdong 510640 (China)

    2009-08-15

    High amounts of acid compounds in bio-oil not only lead to the deleterious properties such as corrosiveness and high acidity, but also set up many obstacles to its wide applications. By hydrotreating the bio-oil under mild conditions, some carboxylic acid compounds could be converted to alcohols which would esterify with the unconverted acids in the bio-oil to produce esters. The properties of the bio-oil could be improved by this method. In the paper, the raw bio-oil was produced by vacuum pyrolysis of pine sawdust. The optimal production conditions were investigated. A series of nickel-based catalysts were prepared. Their catalytic activities were evaluated by upgrading of model compound (glacial acetic acid). Results showed that the reduced Mo-10Ni/{gamma}-Al{sub 2}O{sub 3} catalyst had the highest activity with the acetic acid conversion of 33.2%. Upgrading of the raw bio-oil was investigated over reduced Mo-10Ni/{gamma}-Al{sub 2}O{sub 3} catalyst. After the upgrading process, the pH value of the bio-oil increased from 2.16 to 2.84. The water content increased from 46.2 wt.% to 58.99 wt.%. The H element content in the bio-oil increased from 6.61 wt.% to 6.93 wt.%. The dynamic viscosity decreased a little. The results of GC-MS spectrometry analysis showed that the ester compounds in the upgraded bio-oil increased by 3 times. It is possible to improve the properties of bio-oil by hydrotreating and esterifying carboxyl group compounds in the bio-oil. (author)

  12. Radiological Risk Assessments for Occupational Exposure at Fuel Fabrication Facility in AlTuwaitha Site Baghdad – Iraq by using RESRAD Computer Code

    Science.gov (United States)

    Ibrahim, Ziadoon H.; Ibrahim, S. A.; Mohammed, M. K.; Shaban, A. H.

    2018-05-01

    The purpose of this study is to evaluate the radiological risks for workers for one year of their activities at Fuel Fabrication Facility (FFF) so as to make the necessary protection to prevent or minimize risks resulted from these activities this site now is under the Iraqi decommissioning program (40). Soil samples surface and subsurface were collected from different positions of this facility and analyzed by gamma rays spectroscopy technique High Purity Germanium detector (HPGe) was used. It was found out admixture of radioactive isotopes (232Th 40K 238U 235U137Cs) according to the laboratory results the highest values were (975758) for 238U (21203) for 235U (218) for 232Th (4046) for 40K and (129) for 137Cs in (Bqkg1) unit. The annual total radiation dose and risks were estimated by using RESRAD (onsite) 70 computer code. The highest total radiation dose was (5617μSv/year) in area that represented by soil sample (S7) and the radiological risks morbidity and mortality (118E02 8661E03) respectively in the same area

  13. Preparation and characterization of PVA/SSA membranes with Al{sub 2}O{sub 3} nanoparticles for fuel cell applications; Preparacao de caracterizacao de membranas de PVAL/SSA na presenca de nanoparticulas de Al{sub 2}O{sub 3} para aplicacao em celulas de combustivel

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Paula N.; Pires, Alfredo T.N. [Grupo de Estudo em Materiais Polimericos - POLIMAT - UFSC, Florianopolis, SC (Brazil); Catarino, Margarida; Brandao, Lucia; Tanaka, Alfredo; Mendes, Adelio [Faculdade de Engenharia da Universidade do Porto, Porto (Portugal)

    2011-07-01

    In the present study, PVA/SSA membranes were prepared with and without the addition of Al{sub 2}O{sub 3} nanoparticles. Sulfosuccinic acid (SSA) was used as the crosslinking agent. Membranes were prepared with different amounts of SSA (26, 43 and 55 wt.%) and with 5 and 10 wt.% of nanoparticles. Crosslinking was performed at 90 degree C during 1.5 h. Membranes were analyzed by infrared spectroscopy, thermal analysis, water absorption, ion exchange capacity (IEC) and proton conductivity. The results showed that control of the crosslinking conditions, IEC value, water absorption and polymer structure are of significant importance to obtain a set of properties suitable for application in proton exchange membrane fuel cells. (author)

  14. Contribuições de Vigotski para a educação de pessoas com deficiência visual Contribuciones de Vigotski para la educación de personas con deficiencia visual Vygotski's contributions for the education of visually disabled people

    Directory of Open Access Journals (Sweden)

    Adriano Henrique Nuernberg

    2008-06-01

    Full Text Available Entre as contribuições da psicologia histórico-cultural de Vigotski para a educação destacam-se aquelas que fazem referência às condições analisadas no contexto da defectologia. Esse artigo identifica algumas destas contribuições para a intervenção educacional junto a pessoas com deficiência. Para tanto, são revisados estudos fundamentados em Vigotski que apontam subsídios para a educação de pessoas com deficiência intelectual, surdez, surdocegueira, entre outras condições. Com vista a aprofundar os aportes vigotskianos para educação de pessoas com cegueira, analisa-se o conceito de sistemas psicológicos e seu valor para a reflexão sobre a intervenção educativa no contexto da deficiência visual. Conclui-se este estudo ressaltando-se que os aportes de Vigotski trazem à tona pistas concretas para a implementação de experiências educacionais que favoreçam a autonomia e a cidadania das pessoas com deficiência visual.Entre las contribuciones de la psicología histórico-cultural de Vigotski para la educación se destacan aquellas que hacen referencia a las condiciones analizadas en el contexto de la defectología. Ese artigo identifica algunas de estas contribuciones para la intervención educacional junto a personas con deficiencia. Para tanto, son revisados estudios fundamentados en Vigotski que apuntan subsidios para la educación de personas con deficiencia intelectual, sordez, sordo-ciego, entre otras condiciones. Con vista a profundizar los aportes vigotskianos para educación de personas con ceguera, se analiza el concepto de sistemas psicológicos y su valor para la reflexión sobre la intervención educativa en el contexto de la deficiencia visual. Se concluye este estudio resaltándose que los aportes de Vigotski traen al borde pistas concretas para la implementación de experiencias educacionales que favorezcan la autonomía y la ciudadanía de las personas con deficiencia visual.Among Vygotski

  15. Status of LEU fuel development and conversion of NRU

    International Nuclear Information System (INIS)

    Sears, D.F.; Herbert, L.N.; Vaillancourt, K.D.

    1991-01-01

    This paper reviews the status of the LEU conversion program and the progress made in the fuel development program over the last year. The results from post-irradiation examinations of prototype NRU fuel rods containing Al-U 3 Si dispersion fuel, and of mini-elements containing Al-U 3 Si 2 dispersion fuel, are presented. (orig.)

  16. DART model for irradiation-induced swelling of dispersion fuel elements including aluminum-fuel interaction

    International Nuclear Information System (INIS)

    Rest, J.; Hofman, G.L.

    1997-01-01

    The Dispersion Analysis Research Tool (DART) contains models for fission-gas-induced fuel swelling, interaction of fuel with the matrix aluminum, for the resultant reaction-product swelling, and for the calculation of the stress gradient within the fuel particle. The effects of an aluminide shell on fuel particle swelling are evaluated. Validation of the model is demonstrated by a comparison of DART calculations of fuel swelling of U 3 SiAl-Al and U 3 Si 2 -Al for various dispersion fuel element designs with the data

  17. Fuel assemblies

    International Nuclear Information System (INIS)

    Mukai, Hideyuki

    1987-01-01

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

  18. Effect of kinetic parameters on simultaneous ramp reactivity insertion plus beam tube flooding accident in a typical low enriched U{sub 3}Si{sub 2}-Al fuel-based material testing reactor-type research reactor

    Energy Technology Data Exchange (ETDEWEB)

    Nasir, Rubina; Mirza, Nasir M. [Dept. of, Physics, Air University, Islamabad (Pakistan); Mirza, Sikander M. [Dept. of, Physics and Applied Mathematics, Pakistan Institute of Engineering and Applied Sciences, Post Office Nilore, Islamabad (Pakistan)

    2017-06-15

    This work looks at the effect of changes in kinetic parameters on simultaneous reactivity insertions and beam tube flooding in a typical material testing reactor-type research reactor with low enriched high density (U{sub 3}Si{sub 2}-Al) fuel. Using a modified PARET code, various ramp reactivity insertions (from $0.1/0.5 s to $1.3/0.5 s) plus beam tube flooding ($0.5/0.25 s) accidents under uncontrolled conditions were analyzed to find their effects on peak power, net reactivity, and temperature. Then, the effects of changes in kinetic parameters including the Doppler coefficient, prompt neutron lifetime, and delayed neutron fractions on simultaneous reactivity insertion and beam tube flooding accidents were analyzed. Results show that the power peak values are significantly sensitive to the Doppler coefficient of the system in coupled accidents. The material testing reactor-type system under such a coupled accident is not very sensitive to changes in the prompt neutron life time; the core under such a coupled transient is not very sensitive to changes in the effective delayed neutron fraction.

  19. Further development of microparticle image velocimetry analysis for characterisation of gas streams as a novel method of fuel cell development. Final report; Weiterentwicklung des Mikro-Particle Image Velocimetry Analyseverfahrens zur Charakterisierung von Gasstroemungen als neuartige Entwicklungsmethodik fuer Brennstoffzellen. Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-07-01

    The project aimed at a better understanding of the complex fluid-mechanical processes in the small ducts of bipolar plates. So far, an appropriate technology for in-situ measurement was lacking. The project therefore focused on the further development of microparticle image velocimetry in order to enable analyses of the local velocity distribution of a gas stream in a microduct. Further, measurements were carried out in the microducts of a fuel cell in the more difficult conditions of actual operation. (orig./AKB) [German] Anlass des Forschungsvorhabens war die komplizierten stroemungsmechanischen Zusammenhaenge in den kleinen Kanaelen der Bipolarplatten zu verstehen. Bisher stand keine Messtechnik zur Verfuegung, dies es erlaubt, die stroemungsmechanischen Prozesse in den Mikrokanaelen unter Realbedingungen in situ zu vermessen und mit der instantanen Zellleistung zu korrelieren, Ziel des Projektes war es daher, die Methode der Mikro-Partikel-Image-Velocimetry in der Art weiterzuentwickeln, dass eine Analyse der lokalen Geschwindigkeitsverteilung einer Gasstroemung in einem Mikrokanal ermoeglicht wird. Darueber hinaus wird als zweites Ziel des Projekts eine solche Messung unter den erschwerten Bedingungen einer betriebenen Brennstoffzelle in Mikrokanaelen einer Zelle durchgefuehrt.

  20. Nuclear fuel elements

    International Nuclear Information System (INIS)

    Kawada, Toshiyuki; Hirayama, Satoshi; Yoneya, Katsutoshi.

    1980-01-01

    Purpose: To enable load-depending operation as well as moderation for the restriction of operation conditions in the present nuclear reactors, by specifying the essential ingredients and the total weight of the additives to UO 2 fuel substances. Constitution: Two or more additives selected from Al 2 O 3 , B 2 O, CaO, MgO, SiO 2 , Na 2 O and P 2 O 5 are added by the total weight of 2 - 5% to fuel substances consisting of UO 2 or a mixture of UO 2 and PuO 2 . When the mixture is sintered, the strength of the fuel elements is decreased and the fuel-cladding interactions due to the difference in the heat expansion coefficients between the ceramic fuel elements and the metal claddings are decreased to a substantially harmless degree. (Horiuchi, T.)

  1. The Caramel fuel in OSIRIS

    International Nuclear Information System (INIS)

    Cherruau, Francois.

    1980-11-01

    This paper presents the main characteristics of the caramel fuel, a description of OSIRIS transformations that were decided in line with its conversion and the results of its operation since then. The Caramel fuel is made from sintered UO 2 pellets contained in zircaloy clads forming the plates of the fuel assembly reducing the enrichment need to as little as 3 to 10% instead of 93% enriched U/Al in the previous fuel. The first year of experience shows the capacity under a statistic scale of the caramel fuel to fulfil the most severe operation requirements for use in low and medium power research reactors

  2. Application of a powder sintering-extrusion process to the fabrication of U-Al and UO{sub 2}-stainless steel dispersed fuel elements; Application de frittage-filage de poudres a la fabrication d'elements combustibles disperses U-Al et UO{sub 2} inox

    Energy Technology Data Exchange (ETDEWEB)

    Meny, L.; Buffet, J.; Sauve, Ch.

    1962-07-01

    Within the scope of an investigation of dispersion-type fuel elements, the fabrication by extrusion and sintering of cladded bars and tubes with core of either uranium-aluminum or uranium oxide-stainless steel fuel was investigated. The powder mixtures are first pre-densified in a 'pot', whereupon the sheathed compact is degassed and sealed in a vacuum by electron-beam welding. The subsequent co-extrusion is performed at low temperature and with slow pressure application in the case of U-Al dispersions; and at high temperature with rapid pressure application, using the Ugine-Sejournet process, in the case of UO{sub 2}-stainless steel dispersions. The procedure permits the production of practically fully dense bars and tubes more than 1 m. in length and 10-30 mm in diameter, the wall thickness of the tubes ranging from 2-5 mm. The physical and mechanical characteristics of the dispersion, as well as the mechanical characteristics of the cladded elements, were investigated as a function of the uranium content and the temperature. (authors) [French] Dans le cadre de l'etude des elements combustibles disperses, nous avons etudie la fabrication par frittage-filage de barreaux et de tubes gaines renfermant un noyau combustible soit en uranium-aluminium, soit en UO{sub 2}-inox. Les melanges de poudres sont comprimes dans un 'pot'. La billette composite ainsi obtenue est degazee, fermee et soudee sous vide par bombardement electronique. Le cofilage est ensuite effectue, a basse temperature et sur presse lente pour les disperses U-Al, a haute temperature et sur presse rapide par le procede Ugine-Sejournet pour les disperses UO{sub 2}-inox. Nous avons ainsi obtenu des barres et des tubes de porosite pratiquement nulle de plus de 1 metre de longueur et de 10 a 30 mm de diametre; les epaisseurs des tubes sont comprises entre 2 et 5 mm. Les proprietes physiques et mecaniques des disperses ainsi que les proprietes mecaniques des ensembles gaines, ont ete etudiees en fonction de

  3. Alternative Fuels

    Science.gov (United States)

    Alternative fuels include gaseous fuels such as hydrogen, natural gas, and propane; alcohols such as ethanol, methanol, and butanol; vegetable and waste-derived oils; and electricity. Overview of alternative fuels is here.

  4. Fuel assembly

    International Nuclear Information System (INIS)

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

    1998-01-01

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

  5. Fuel assembly

    International Nuclear Information System (INIS)

    Yamazaki, Hajime.

    1995-01-01

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

  6. Ti, Al

    Indian Academy of Sciences (India)

    In the present study, authors report on the effect that substrate bias voltage has on the microstructure and mechanical properties of (Ti, Al)N hard coatings deposited with cathodic arc evaporation (CAE) technique. The coatings were deposited from a Ti0.5Al0.5 powder metallurgical target in a reactive nitrogen atmosphere at ...

  7. Nuclear fuels

    International Nuclear Information System (INIS)

    Gangwani, Saloni; Chakrabortty, Sumita

    2011-01-01

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

  8. Fuel and nuclear fuel cycle

    International Nuclear Information System (INIS)

    Prunier, C.

    1998-01-01

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

  9. Effect of carbons (G and CFs), TM (Ni, Fe and Al) and oxides (Nb_2O_5 and V_2O_5) on hydrogen generation from ball milled Mg-based hydrolysis reaction for fuel cell

    International Nuclear Information System (INIS)

    Awad, A.S.; El-Asmar, E.; Tayeh, T.; Mauvy, F.; Nakhl, M.; Zakhour, M.; Bobet, J.-L.

    2016-01-01

    This paper dedicated to investigation the effect of carbons (graphite and carbon fibers), transition metals (TM = Ni, Fe and Al) and oxides (Nb_2O_5 and V_2O_5) on Mg–H hydrolysis reaction in aqueous media (3.5 wt% NaCl). Mg – 10 wt% X (X = C, TM and oxides) mixtures were prepared by mechanical milling (1, 3 and 5 h). Mg – 10 wt% G mixtures show the best hydrolysis performance (95% of theoretical hydrogen generation yield in almost 3 min) in comparison to Mg – oxide and Mg – TM mixtures. In addition to the presence of micro-galvanic cells, particle size, MgH_2 content, density defects, fractures and cracking have an important influence on the hydrolysis reaction. Synergetic effect of carbons and transition metals has been studied for Mg – 5 wt% G – 5 wt% Ni mixture. Activation energies were calculated using Avrami–Erofeev model. An activation energy of 14.34 kJ/mol was found for Mg/G/Ni mixture which demonstrates the best hydrolysis behavior (95% of theoretical hydrogen generation yield within 2 min). Hydrogen generated from Mg–H hydrolysis reaction was fed directly to a single Proton Exchange Membrane Fuel Cell (PEMFC). At 0.15 A, the cell voltage exhibited a stable value of approximately 0.52 V for roughly 35 min. - Highlights: • The presence of carbon and transition metals enhance the hydrolysis reaction of magnesium. • The synergetic effect of graphite and Ni leads to the best hydrolysis kinetics. • Cl"− ions replace OH"− ions to destabilize the Mg(OH)_2 passivation layer. • Production of electricity is feasible from hydrogen generated from Mg.

  10. Fuel assembly

    International Nuclear Information System (INIS)

    Sakuyama, Tadashi; Mukai, Hideyuki.

    1988-01-01

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

  11. Advanced Research Reactor Fuel Development

    Energy Technology Data Exchange (ETDEWEB)

    Kim, C. K.; Park, H. D.; Kim, K. H. (and others)

    2006-04-15

    RERTR program for non-proliferation has propelled to develop high-density U-Mo dispersion fuels, reprocessable and available as nuclear fuel for high performance research reactors in the world. As the centrifugal atomization technology, invented in KAERI, is optimum to fabricate high-density U-Mo fuel powders, it has a great possibility to be applied in commercialization if the atomized fuel shows an acceptable in-reactor performance in irradiation test for qualification. In addition, if rod-type U-Mo dispersion fuel is developed for qualification, it is a great possibility to export the HANARO technology and the U-Mo dispersion fuel to the research reactors supplied in foreign countries in future. In this project, reprocessable rod-type U-Mo test fuel was fabricated, and irradiated in HANARO. New U-Mo fuel to suppress the interaction between U-Mo and Al matrix was designed and evaluated for in-reactor irradiation test. The fabrication process of new U-Mo fuel developed, and the irradiation test fuel was fabricated. In-reactor irradiation data for practical use of U-Mo fuel was collected and evaluated. Application plan of atomized U-Mo powder to the commercialization of U-Mo fuel was investigated.

  12. Fuel processing

    International Nuclear Information System (INIS)

    Allardice, R.H.

    1990-01-01

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

  13. Fuel storage

    International Nuclear Information System (INIS)

    Palacios, C.; Alvarez-Miranda, A.

    2009-01-01

    ENSA is a well known manufacturer of multi-system primary components for the nuclear industry and is totally prepared to satisfy future market requirements in this industry. At the same time that ENSA has been gaining a reputation world wider for the supply of primary components, has been strengthening its commitment and experience in supplying spent fuel components, either pool racks or storage and transportation casks, and offers not only fabrication but also design capabilities for its products. ENSA has supplied Spent Fuel Pool Racks, in spain, Finland, Taiwan, Korea, China, and currently it is in the process of licensing its own rack design in the United States of America for the ESBWR along with Ge-Hitachi. ENSA has supplied racks for 20 pools and 22 different reactors and it has also manufactured racks under all available technologies and developed a design known as Interlock Cell Matrix whose main features are outlined in this article. Another ENSA achievement in rack technology is the use of remote control for re-racking activities instead of using divers, which improves the ALARA requirements. Regarding casks for storage and transportation, ENSA also has al leading worldwide position, with exports prevailing over the Spanish market where ENSA has supplied 16 storage and transportation casks to the Spanish nuclear power Trillo. In some cases, ENSA acts as subcontractor for other clients. Foreign markets are still a major challenge for ENSA. ENSA-is well known for its manufacturing capabilities in the nuclear industry, but has been always involved in design activities through its engineering division, which carries out different tasks: components Design; Tooling Design; Engineering and Documentation; Project Engineering; Calculations, Design and Development Engineering. (Author)

  14. Dispersion fuel for nuclear research facilities

    International Nuclear Information System (INIS)

    Kushtym, A.V.; Belash, M.M.; Zigunov, V.V.; Slabospitska, O.O.; Zuyok, V.A.

    2017-01-01

    Designs and process flow sheets for production of nuclear fuel rod elements and assemblies TVS-XD with dispersion composition UO_2+Al are presented. The results of fuel rod thermal calculation applied to Kharkiv subcritical assembly and Kyiv research reactor VVR-M, comparative characteristics of these fuel elements, the results of metallographic analyses and corrosion tests of fuel pellets are given in this paper

  15. Fuel assembly

    International Nuclear Information System (INIS)

    Fujibayashi, Toru.

    1970-01-01

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

  16. Nuclear fuel

    International Nuclear Information System (INIS)

    D Hondt, P.

    1998-01-01

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

  17. Reactivity feedbacks of a material test research reactor fueled with various low enriched uranium dispersion fuels

    International Nuclear Information System (INIS)

    Muhammad, Farhan; Majid, Asad

    2009-01-01

    The reactivity feedbacks of a material test research reactor using various low enriched uranium fuels, having same uranium density were calculated. For this purpose, the original aluminide fuel (UAl x -Al) containing 4.40 gU/cm 3 of an MTR was replaced with silicide (U 3 Si-Al and U 3 Si 2 -Al) and oxide (U 3 O 8 -Al) dispersion fuels having the same uranium density as of the original fuel. Calculations were carried out to find the fuel temperature reactivity feedback, moderator temperature reactivity feedback, moderator density reactivity feedback and moderator void reactivity feedback. Nuclear reactor analysis codes including WIMS-D4 and CITATION were employed to carry out these calculations. It was observed that the magnitudes all the respective reactivity feedbacks from 38 deg. C to 50 deg. C and 100 deg. C, at the beginning of life, of all the fuels were very close to each other. The fuel temperature reactivity feedback of the U 3 O 8 -Al was about 2% more than the original UAl x -Al fuel. The magnitudes of the moderator temperature, moderator density and moderator void reactivity feedbacks of all the fuels, showed very minor variations from the original aluminide fuel.

  18. Fuel management

    International Nuclear Information System (INIS)

    Schwarz, E.R.

    1975-01-01

    Description of the operation of power plants and the respective procurement of fuel to fulfil the needs of the grid. The operation of the plants shall be optimised with respect to the fuel cost. (orig./RW) [de

  19. Fuel gases

    International Nuclear Information System (INIS)

    Anon.

    1996-01-01

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

  20. Fuel cycles

    International Nuclear Information System (INIS)

    Hawley, N.J.

    1983-05-01

    AECL publications, from the open literature, on fuels and fuel cycles used in CANDU reactors are listed in this bibliography. The accompanying index is by subject. The bibliography will be brought up to date periodically

  1. Nuclear fuels

    International Nuclear Information System (INIS)

    2008-01-01

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

  2. Fuel pellet

    International Nuclear Information System (INIS)

    Hayashi, K.

    1980-01-01

    Fuel pellet for insertion into a cladding tube in order to form a fuel element or a fuel rod. The fuel pellet has got a belt-like projection around its essentially cylindrical lateral circumferential surface. The upper and lower edges in vertical direction of this belt-like projection are wave-shaped. The projection is made of the same material as the bulk pellet. Both are made in one piece. (orig.) [de

  3. Modelling Accident Tolerant Fuel Concepts

    Energy Technology Data Exchange (ETDEWEB)

    Hales, Jason Dean [Idaho National Laboratory; Gamble, Kyle Allan Lawrence [Idaho National Laboratory

    2016-05-01

    The catastrophic events that occurred at the Fukushima-Daiichi nuclear power plant in 2011 have led to widespread interest in research of alternative fuels and claddings that are proposed to be accident tolerant. The United States Department of Energy (DOE) through its Nuclear Energy Advanced Modeling and Simulation (NEAMS) program has funded an Accident Tolerant Fuel (ATF) High Impact Problem (HIP). The ATF HIP is a three-year project to perform research on two accident tolerant concepts. The final outcome of the ATF HIP will be an in-depth report to the DOE Advanced Fuels Campaign (AFC) giving a recommendation on whether either of the two concepts should be included in their lead test assembly scheduled for placement into a commercial reactor in 2022. The two ATF concepts under investigation in the HIP are uranium silicide fuel and iron-chromium-aluminum (FeCrAl) alloy cladding. Utilizing the expertise of three national laboratory participants (Idaho National Laboratory, Los Alamos National Laboratory, and Argonne National Laboratory), a comprehensive multiscale approach to modeling is being used that includes atomistic modeling, molecular dynamics, rate theory, phase-field, and fuel performance simulations. Model development and fuel performance analysis are critical since a full suite of experimental studies will not be complete before AFC must prioritize concepts for focused development. In this paper, we present simulations of the two proposed accident tolerance fuel systems: U3Si2 fuel with Zircaloy-4 cladding, and UO2 fuel with FeCrAl cladding. Sensitivity analyses are completed using Sandia National Laboratories’ Dakota software to determine which input parameters (e.g., fuel specific heat) have the greatest influence on the output metrics of interest (e.g., fuel centerline temperature). We also outline the multiscale modelling approach being employed. Considerable additional work is required prior to preparing the recommendation report for the Advanced

  4. Fossil Fuels.

    Science.gov (United States)

    Crank, Ron

    This instructional unit is one of 10 developed by students on various energy-related areas that deals specifically with fossil fuels. Some topics covered are historic facts, development of fuels, history of oil production, current and future trends of the oil industry, refining fossil fuels, and environmental problems. Material in each unit may…

  5. Fuel element

    International Nuclear Information System (INIS)

    1974-01-01

    A new fuel can with a loose bottom and head is described. The fuel bar is attached to the loose bottom and head with two grid poles keeping the distance between bottom and head. A bow-shaped handle is attached to the head so that the fuel bar can be lifted from the can

  6. Axial profiles of burned and fraction of holes for calculations of criticality with credit for BWR fuel burning; Perfiles axiales de quemado y fraccion de huecos para calculos de criticidad con credito al quemado para combustible BWR

    Energy Technology Data Exchange (ETDEWEB)

    Casado Sanchez, C.; Rubio Oviedo, P.

    2014-07-01

    This paper presents a method to define surround profiles of burning and fraction of holes suited for use in applications of credit to burning of BWR fuel from results obtained with the module STARBUCS of SCALE. (Author)

  7. Contribuciones al análisis del concepto de escala como instrumento clave en el contexto multiparadigmático de la Geografía contemporánea

    Directory of Open Access Journals (Sweden)

    Cristina Ofelia Valenzuela

    2012-02-01

    Full Text Available La determinación de las escalas espaciales más adecuadas para el estudio de un problema geográfico concreto es compleja. Significa básicamente la selección inicial de una escala por sobre las demás. Esto, a su vez, sugiere la consideración de dos cuestiones: cómo se define una escala y cuál es la “adecuada” para el estudio de la realidad, ya que lo que parece significativo o tiene sentido en una escala no tiene porqué registrarse en otra con la misma intensidad o importancia. El objetivo de este trabajo es contribuir a la discusión sobre el tema, subrayando la importancia de las conceptualizaciones sobre las escalas espaciales y su aplicación en las distintas corrientes de pensamiento geográfico contemporáneo.

  8. Radiochemical applications of insoluble sulfate columns. Analytical possibilities in the field of the fission product solutions; Aplicaciones radioquimica de las columnas de precipitados de sulfatos insolubles. Contribucion al estudio de las soluciones envejecidas de productos de fision

    Energy Technology Data Exchange (ETDEWEB)

    Barrachina, M; Sauvagnac, R

    1962-07-01

    In this paper we go on with our study of the heterogeneous ion-isotopic exchange in column. At present, we apply it to determine the radiochemical composition of the raw solutions used in the industrial recuperation of the long-lived fission products. The separation of the radioelements contained in these solutions is carried out mainly by making use of small columns, 1-3 cm height, of BaSO{sub 4} or SrSO{sub 4}, under selected experimental conditions. These columns behave like a special type of inorganic exchangers, working by absorption or by ion-isotopic exchange depending on the cases,a nd they provide the means for the selective separation of several important fission products employing very small volumes of fixing and eluting solutions. (Author) 11 refs.

  9. Nuevas contribuciones al estudio de Corixoidea: caracterización citogenética de tres especies de Sigara de Argentina y los posibles mecanismos de evolución del cariotipo en Nepomorpha

    OpenAIRE

    Bressa, María José; Papeschi, Alba Graciela

    2007-01-01

    Cytogenetic studies in Heteroptera contribute to the analysis of evolutionary trends within the group. Heteroptera are characterized by the possession of holokinetic chromosomes, different sex chromosome mechanisms and a pair of m chromosomes in some species. In the present work, the male karyotype and meiosis in Sigara denseconscripta (Breddin), S. chrostowskii Jaczewski, and S. rubyae (Hungerford) are described. The three species share a diploid chromosome number of 2n= 24 with a pair of m ...

  10. Contributions of the National Institute of Nuclear Research to the advance of Science and Technology in Mexico. Commemorative edition 2010; Contribuciones del Instituto Nacional de Investigaciones Nucleares al avance de la ciencia y la tecnologia en Mexico. Edicion conmemorativa 2010

    Energy Technology Data Exchange (ETDEWEB)

    Duque M, G.; Jimenez R, M.; Monroy G, F.; Romero H, S.; Serment G, J. (ed.) [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2010-07-01

    From the second decade of the X X century the applications of the nuclear energy have been important part of the scientific and technological patrimony in Mexico. Records exist with regard to the use of the radioisotopes and the radiations in our country in that time, and in a formal way until the year of 1950, in a process that culminates with the creation of the Comision Nacional de Energia Nuclear (CNEN. January 1, 1956). In January 12, 1972 were published the Organic Law that created to the Instituto Nacional de Energia Nuclear, being responsible for the works that the CNEN developed. The current Instituto Nacional de Investigaciones Nucleares (ININ) was constituted starting from the Regulation Law of the constitutional Article 27 in nuclear matter of January 26, 1979, abrogated and substituted by the Law in force of February 4, 1985. In this lapse they were undertaken multitude of projects with results and diverse achievements. From their creation, the mission of the ININ and the previous institutions has been to realize research in science and nuclear technology, to promote their peaceful uses and to diffuse the achieved advances, always searching for to link them to the economic, social, scientific and technological development of the country. In this occasion with the purpose of participating in the commemoration of the bicentennial of the independence and centennial of the Mexican revolution in our country, the ININ decided to publish this work, directed to a wide public, with the intention of providing a vision the most complete and appropriate possible of the activities in research and technology that it is carries out at the moment. This work also seeks to be a diffusion instrument of the tasks that they are carried out in the institute, in diverse subjects as: the basic research, the nuclear applications in the health, the agriculture and the industry, the studies on the contamination and the environment; the dosimetry; the radiological protection; as well as the diverse services that the ININ offer to the nuclear power plant of Laguna Verde, their reactors and facilities. (Author)

  11. Final disposition of MTR fuel

    International Nuclear Information System (INIS)

    Jonnson, Erik B.

    1996-01-01

    The final disposition of power reactor fuel has been investigated for a long time and some promising solutions to the problem have been shown. The research reactor fuels are normally not compatible with the zirkonium clad power reactor fuel and can thus not rely on the same disposal methods. The MTR fuels are typically Al-clad UAl x or U 3 Si 2 , HEU resp. LEU with essentially higher remaining enrichment than the corresponding power reactor fuel after full utilization of the uranium. The problems arising when evaluating the conditions at the final repository are the high corrosion rate of aluminum and uranium metal and the risk for secondary criticality due to the high content on fissionable material in the fully burnt MTR fuel. The newly adopted US policy to take back Foreign Research Reactor Spent Fuel of US origin for a period of ten years have given the research reactor society a reasonable time to evaluate different possibilities to solve the back end of the fuel cycle. The problem is, however, complicated and requires a solid engagement from the research reactor community. The task would be a suitable continuation of the RERTR program as it involves both the development of new fuel types and collecting data for the safe long-term disposal of the spent MTR fuel. (author)

  12. LPG fuel

    International Nuclear Information System (INIS)

    Dagnas, F.X.; Jeuland, N.; Fouquet, J.P.; Lauraire, S.; Coroller, P.

    2005-01-01

    LPG fuel has become frequently used through a distribution network with 2 000 service stations over the French territory. LPG fuel ranks number 3 world-wide given that it can be used on individual vehicles, professional fleets, or public transport. What is the environmental benefit of LPG fuel? What is the technology used for these engines? What is the current regulation? Government commitment and dedication on support to promote LPG fuel? Car makers projects? Actions to favour the use of LPG fuel? This article gathers 5 presentations about this topic given at the gas conference

  13. Desulphurization of middle distillates using Ni/Al{sub 2}O{sub 3} adsorbents for the use in fuel cell Systems; Entschwefelung von Mitteldestillaten ueber Ni/Al{sub 2}O{sub 3}-Adsorber fuer den Einsatz in Brennstoffzellensystemen. Reaktionsmechanismus und Einsatzgrenzen

    Energy Technology Data Exchange (ETDEWEB)

    Rheinberg, Oliver van [RWTH Aachen Univ., Herzogenrath (Germany). An-Institut OWI - Oel-Waerme-Institut GmbH

    2012-10-15

    An ultra deep desulphurisation of less than 1 mg/kg of sulphur is necessary for the use of commercial liquid fuels in modern fuel cell systems. To reach this goal, the adsorptive desulphurisation has been chosen in scope of the current investigations. By validation of influencing parameters and by determination of optimum operation conditions a deep understanding of the current processes such as the reaction mechanism has been established. As a result the process has been improved by adding hydrogen donators as additives in liquid fuels. Furthermore it has been shown, that polar and unsaturated compounds in liquid fuels have to be avoided and aromatics have to be reduced, as all of them influence the adsorptive desulphurisation in a negative way. Despite the achieved improvements a further increase of the adsorbens capacity is necessary. Not till then the overall volume of the adsorbent is as low as required in order to integrate such processes in mobile fuel cell systems. (orig.)

  14. Performance Evaluation of Metallic Dispersion Fuel for Advanced Research Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, Ho Jin; Park, Jong Man; Kim, Chang Kyu; Chae, Hee Taek; Song, Kee Chan [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Kim, Yeon Soo [Argonne National Laboratory, New York (United States)

    2007-07-01

    Uranium alloys with a high uranium density has been developed for high power research reactor fuel using low-enriched uranium (LEU). U-Mo alloys have been developed as candidate fuel material because of excellent irradiation behavior. Irradiation behavior of U-Mo/Al dispersion fuel has been investigated to develop high performance research reactor fuel as RERTR international research program. While plate-type and rod-type dispersion fuel elements are used for research reactors, HANARO uses rod-type dispersion fuel elements. PLATE code is developed by Argonne National Laboratory for the performance evaluation of plate-type dispersion fuel, but there is no counterpart for rod-type dispersion fuel. Especially, thermal conductivity of fuel meat decreases during the irradiation mainly because of interaction layer formation at the interface between the U-Mo fuel particle and Al matrix. The thermal conductivity of the interaction layer is not as high as the Al matrix. The growth of interaction layer is interactively affected by the temperature of fuel because it is associated with a diffusion reaction which is a thermally activated process. It is difficult to estimate the temperature profile during irradiation test due to the interdependency of fuel temperature and thermal conductivity changed by interaction layer growth. In this study, fuel performance of rod-type U-Mo/Al dispersion fuels during irradiation tests were estimated by considering the effect of interaction layer growth on the thermal conductivity of fuel meat.

  15. Performance Evaluation of Metallic Dispersion Fuel for Advanced Research Reactors

    International Nuclear Information System (INIS)

    Ryu, Ho Jin; Park, Jong Man; Kim, Chang Kyu; Chae, Hee Taek; Song, Kee Chan; Kim, Yeon Soo

    2007-01-01

    Uranium alloys with a high uranium density has been developed for high power research reactor fuel using low-enriched uranium (LEU). U-Mo alloys have been developed as candidate fuel material because of excellent irradiation behavior. Irradiation behavior of U-Mo/Al dispersion fuel has been investigated to develop high performance research reactor fuel as RERTR international research program. While plate-type and rod-type dispersion fuel elements are used for research reactors, HANARO uses rod-type dispersion fuel elements. PLATE code is developed by Argonne National Laboratory for the performance evaluation of plate-type dispersion fuel, but there is no counterpart for rod-type dispersion fuel. Especially, thermal conductivity of fuel meat decreases during the irradiation mainly because of interaction layer formation at the interface between the U-Mo fuel particle and Al matrix. The thermal conductivity of the interaction layer is not as high as the Al matrix. The growth of interaction layer is interactively affected by the temperature of fuel because it is associated with a diffusion reaction which is a thermally activated process. It is difficult to estimate the temperature profile during irradiation test due to the interdependency of fuel temperature and thermal conductivity changed by interaction layer growth. In this study, fuel performance of rod-type U-Mo/Al dispersion fuels during irradiation tests were estimated by considering the effect of interaction layer growth on the thermal conductivity of fuel meat

  16. Nuclear fuels for material test reactors

    International Nuclear Information System (INIS)

    Ramanathan, L.V.; Durazzo, M.; Freitas, C.T. de

    1982-01-01

    Experimental results related do the development of nuclear fuels for reactors cooled and moderated by water have been presented cylindrical and plate type fuels have been described in which the core consists of U compouns dispersed in an Al matrix and is clad with aluminium. Fabrication details involving rollmilling, swaging or hot pressing have been described. Corrosion and irradiation test results are also discussed. The performance of the different types of fuels indicates that it is possible to locally fabricate fuel plates with U 3 O 8 +Al cores (20% enriched U) for use in operating Brazilian research reactors. (Author) [pt

  17. Fuel assembly

    International Nuclear Information System (INIS)

    Ueda, Makoto; Ogiya, Shunsuke.

    1989-01-01

    For improving the economy of a BWR type reactor by making the operation cycle longer, the fuel enrichment degree has to be increased further. However, this makes the subcriticality shallower in the upper portion of the reactor core, to bring about a possibility that the reactor shutdown becomes impossible. In the present invention, a portion of fuel rod is constituted as partial length fuel rods (P-fuel rods) in which the entire stack length in the effective portion is made shorter by reducing the concentration of fissionable materials in the axial portion. A plurality of moderator rods are disposed at least on one diagonal line of a fuel assembly and P-fuel rods are arranged at a position put between the moderator rods. This makes it possible to reactor shutdown and makes the axial power distribution satisfactory even if the fuel enrichment degree is increased. (T.M.)

  18. Fuel Services

    International Nuclear Information System (INIS)

    Silberstein, A.

    1982-09-01

    FRAGEMA has developed most types of inspection equipments to work on irradiated fuel assemblies and on single fuel rods during reactor outages with an efficiency compatible with the utilities operating priorities. In order to illustrate this statement, two specific examples of inspection equipments are shortly described: the on-site removable fuel rod assembly examination stand, and the fuel assembly multiple examination device. FRAGEMA has developed techniques for the identifiction of the leaking fuel rods in the fuel assembly and the tooling necessary to perform the replacement of the faulted element. These examples of methods, techniques and equipments described and the experience accumulated through their use allow FRAGEMA to qualify for offering the supply of the corresponding software, hardware or both whenever an accurate understanding of the fuel behaviour is necessary and whenever direct intervention on the assembly and associated components is necessary due to safety, operating or economical reasons

  19. Fuel assembly

    International Nuclear Information System (INIS)

    Watanabe, Shoichi; Hirano, Yasushi.

    1998-01-01

    A one-half or more of entire fuel rods in a fuel assembly comprises MOX fuel rods containing less than 1wt% of burnable poisons, and at least a portion of the burnable poisons comprises gadolinium. Then, surplus reactivity at an initial stage of operation cycle is controlled to eliminate burnable poisons remained unburnt at a final stage, as well as increase thermal reactivity. In addition, the content of fission plutonium is determined to greater than the content of uranium 235, and fuel rods at corner portions are made not to incorporate burnable poisons. Fuel rods not containing burnable poisons are disposed at positions in adjacent with fuel rods facing to a water rod at one or two directions. Local power at radial center of the fuel assembly is increased to flatten the distortion of radial power distribution. (N.H.)

  20. Fuel gas production from renewable biomass in a circulating fluidized bed as a bases for zero-CO{sub 2} power generation in a combined-cycle power plant; Brenngaserzeugung aus nachwachsenden Biomassen in der zirkulierenden Wirbelschicht als Grundlage fuer eine CO{sub 2}-neutrale Stromerzeugung in einem GUD Kraftwerk

    Energy Technology Data Exchange (ETDEWEB)

    Albrecht, J.; Loeffler, J.; Hirschfelder, H. [Lurgi Energie und Umwelt GmbH, Frankfurt am Main (Germany)

    1996-12-31

    A pilot circulating fluidized bed plant in the range of 1.7 MW{sub th} has been operated successfully with fossil fuels, residues, wood bark and wood chips, reet grass and sorghum pellets. Depending on the specifications for product gas and fuel quality, air, oxygen-enriched air or oxygen/steam mixtures are used as gasification agents in the gas generator. (orig) [Deutsch] In einer ZWS-Pilotanlage mit ca. 1.7 MW thermischer Leistung wurden bisher ausser fossilen und Abfallbrennstoffen auch Rindenabfaelle, Holzschnitzel, Schilfgras und Sorghumpellets erfolgreich zur Brenngaserzeugung eingesetzt. Entsprechend den Anforderungen an das Produktgas und der Brennstoffqualitaet wird Luft, sauerstoffangereicherte Luft oder Sauerstoff/Dampfgemische als Vergasungsmittel im ZWS-Gaserzeuger eingesetzt. (orig)

  1. Fuel gas production from renewable biomass in a circulating fluidized bed as a bases for zero-CO{sub 2} power generation in a combined-cycle power plant; Brenngaserzeugung aus nachwachsenden Biomassen in der zirkulierenden Wirbelschicht als Grundlage fuer eine CO{sub 2}-neutrale Stromerzeugung in einem GUD Kraftwerk

    Energy Technology Data Exchange (ETDEWEB)

    Albrecht, J; Loeffler, J; Hirschfelder, H [Lurgi Energie und Umwelt GmbH, Frankfurt am Main (Germany)

    1997-12-31

    A pilot circulating fluidized bed plant in the range of 1.7 MW{sub th} has been operated successfully with fossil fuels, residues, wood bark and wood chips, reet grass and sorghum pellets. Depending on the specifications for product gas and fuel quality, air, oxygen-enriched air or oxygen/steam mixtures are used as gasification agents in the gas generator. (orig) [Deutsch] In einer ZWS-Pilotanlage mit ca. 1.7 MW thermischer Leistung wurden bisher ausser fossilen und Abfallbrennstoffen auch Rindenabfaelle, Holzschnitzel, Schilfgras und Sorghumpellets erfolgreich zur Brenngaserzeugung eingesetzt. Entsprechend den Anforderungen an das Produktgas und der Brennstoffqualitaet wird Luft, sauerstoffangereicherte Luft oder Sauerstoff/Dampfgemische als Vergasungsmittel im ZWS-Gaserzeuger eingesetzt. (orig)

  2. PIE Report on the KOMO-3 Irradiation Test Fuels

    International Nuclear Information System (INIS)

    Park, Jong Man; Ryu, H. J.; Yang, J. H.

    2009-04-01

    In the KOMO-3, in-reactor irradiation test had been performed for 12 kinds of dispersed U-Mo fuel rods, a multi wire fuel rod and a tube fuel rod. In this report we described the PIE results on the KOMO-3 irradiation test fuels. The interaction layer thickness between fuel particle and matrix could be reduced by using a large size U-Mo fuel particle or introducing Al-Si matrix or adding the third element in the U-Mo particle. Monolithic fuel rod of multi-wire or tube fuel was also effective in reducing the interaction layer thickness

  3. AL Amyloidosis

    Directory of Open Access Journals (Sweden)

    Desport Estelle

    2012-08-01

    Full Text Available Abstract Definition of the disease AL amyloidosis results from extra-cellular deposition of fibril-forming monoclonal immunoglobulin (Ig light chains (LC (most commonly of lambda isotype usually secreted by a small plasma cell clone. Most patients have evidence of isolated monoclonal gammopathy or smoldering myeloma, and the occurrence of AL amyloidosis in patients with symptomatic multiple myeloma or other B-cell lymphoproliferative disorders is unusual. The key event in the development of AL amyloidosis is the change in the secondary or tertiary structure of an abnormal monoclonal LC, which results in instable conformation. This conformational change is responsible for abnormal folding of the LC, rich in β leaves, which assemble into monomers that stack together to form amyloid fibrils. Epidemiology AL amyloidosis is the most common type of systemic amyloidois in developed countries with an estimated incidence of 9 cases/million inhabitant/year. The average age of diagnosed patients is 65 years and less than 10% of patients are under 50. Clinical description The clinical presentation is protean, because of the wide number of tissues or organs that may be affected. The most common presenting symptoms are asthenia and dyspnoea, which are poorly specific and may account for delayed diagnosis. Renal manifestations are the most frequent, affecting two thirds of patients at presentation. They are characterized by heavy proteinuria, with nephrotic syndrome and impaired renal function in half of the patients. Heart involvement, which is present at diagnosis in more than 50% of patients, leading to restrictive cardiopathy, is the most serious complication and engages prognosis. Diagnostic methods The diagnosis relies on pathological examination of an involved site showing Congo red-positive amyloid deposits, with typical apple-green birefringence under polarized light, that stain positive with an anti-LC antibody by immunohistochemistry and

  4. Fuel assembly

    International Nuclear Information System (INIS)

    Nakatsuka, Masafumi; Matsuzuka, Ryuji.

    1976-01-01

    Object: To provide a fuel assembly which can decrease pressure loss of coolant to uniform temperature. Structure: A sectional area of a flow passage in the vicinity of an inner peripheral surface of a wrapper tube is limited over the entire length to prevent the temperature of a fuel element in the outermost peripheral portion from being excessively decreased to thereby flatten temperature distribution. To this end, a plurality of pincture-frame-like sheet metals constituting a spacer for supporting a fuel assembly, which has a plurality of fuel elements planted lengthwise and in given spaced relation within the wrapper tube, is disposed in longitudinal grooves and in stacked fashion to form a substantially honeycomb-like space in cross section. The fuel elements are inserted and supported in the space to form a fuel assembly. (Kamimura, M.)

  5. Fuel assemblies

    International Nuclear Information System (INIS)

    Nagano, Mamoru; Yoshioka, Ritsuo

    1983-01-01

    Purpose: To effectively utilize nuclear fuels by increasing the reactivity of a fuel assembly and reduce the concentration at the central region thereof upon completion of the burning. Constitution: A fuel assembly is bisected into a central region and a peripheral region by disposing an inner channel box within a channel box. The flow rate of coolants passing through the central region is made greater than that in the peripheral region. The concentration of uranium 235 of the fuel rods in the central region is made higher. In such a structure, since the moderating effect in the central region is improved, the reactivity of the fuel assembly is increased and the uranium concentration in the central region upon completion of the burning can be reduced, fuel economy and effective utilization of uranium can be attained. (Kamimura, M.)

  6. Fuel assembly

    International Nuclear Information System (INIS)

    Bando, Masaru.

    1993-01-01

    As neutron irradiation progresses on a fuel assembly of an FBR type reactor, a strong force is exerted to cause ruptures if the arrangement of fuel elements is not displaced, whereas the fuel elements may be brought into direct contact with each other not by way of spacers to cause burning damages if the arrangement is displaced. In the present invention, the circumference of fuel elements arranged in a normal triangle lattice is surrounded by a wrapper tube having a hexagonal cross section, wire spacers are wound therearound, and deformable spacers are distributed to optional positions for fuel elements in the wrapper tube. Interaction between the fuel elements caused by irradiation is effectively absorbed, thereby enabling to delay the occurrence of the rupture and burning damages of the elements. (N.H.)

  7. Fuel assembly

    International Nuclear Information System (INIS)

    Yokota, Tokunobu.

    1990-01-01

    A fuel assembly used in a FBR type nuclear reactor comprises a plurality of fuel rods and a moderator guide member (water rod). A moderator exit opening/closing mechanism is formed at the upper portion of the moderator guide member for opening and closing a moderator exit. In the initial fuel charging operation cycle to the reactor, the moderator exit is closed by the moderator exit opening/closing mechanism. Then, voids are accumulated at the inner upper portion of the moderator guide member to harden spectrum and a great amount of plutonium is generated and accumulated in the fuel assembly. Further, in the fuel re-charging operation cycle, the moderator guide member is used having the moderator exit opened. In this case, voids are discharged from the moderator guide member to decrease the ratio, and the plutonium accumulated in the initial charging operation cycle is burnt. In this way, the fuel economy can be improved. (I.N.)

  8. Fuel spacer

    International Nuclear Information System (INIS)

    Nishida, Koji; Yokomizo, Osamu; Kanazawa, Toru; Kashiwai, Shin-ichi; Orii, Akihito.

    1992-01-01

    The present invention concerns a fuel spacer for a fuel assembly of a BWR type reactor and a PTR type reactor. Springs each having a vane are disposed on the side surface of a circular cell which supports a fuel rods. A vortex streams having a vertical component are formed by the vanes in the flowing direction of a flowing channel between adjacent cylindrical cells. Liquid droplets carried by streams are deposited on liquid membrane streams flowing along the fuel rod at the downstream of the spacer by the vortex streams. In view of the above, the liquid droplets can be deposited to the fuel rod without increasing the amount of metal of the spacer. Accordingly, the thermal margin of the fuel assembly can be improved without losing neutron economy. (I.N.)

  9. Fuels for Canadian research reactors

    International Nuclear Information System (INIS)

    Feraday, M.A.

    1993-01-01

    This paper includes some statements and remarks concerning the uranium silicide fuels for which there is significant fabrication in AECL, irradiation and defect performance experience; description of two Canadian high flux research reactors which use high enrichment uranium (HEU) and the fuels currently used in these reactors; limited fabrication work done on Al-U alloys to uranium contents as high as 40 wt%. The latter concerns work aimed at AECL fast neutron program. This experience in general terms is applied to the NRX and NRU designs of fuel

  10. The development of lower enrichment fuels for Canadian research reactors

    Energy Technology Data Exchange (ETDEWEB)

    Feraday, M A; Belanger, L; Grolway, C M [AECL, Atomic Energy of Canada Limited, Chalk River, ON (Canada); Foo, M T [CRNL, Combustion Engineering Superheater Ltd., Moncton, NB (Canada)

    1983-08-01

    As part of the world wide move to proliferation resistant fuels, new fuels which use reduced enrichment uranium are being developed for use in the NRX and NRU reactors. A fuel consisting of particles of a USiAl alloy dispersed in an Al matrix has been selected for development along with Al-37 wt% U alloy and Al-U{sub 3}O{sub 8} cermet as backup fuels. This report outlines the progress made in the development of the Al-USiAl and Al-37 wt% U. Results show that good quality extruded rods containing either fuel can be made with techniques similar to those used to fabricate the current NRX and NRU fuels. However, the new fuels will be more expensive to make. Although the oxidation behaviour of the Al-USiAl is not as good as that of the Al-U alloys, its corrosion behaviour in high temperature water does not seem much worse. The oxidation and aqueous corrosion of A-37 wt% U are not much different from those of the Al-U alloys currently used. (author)

  11. Fuel Cells

    DEFF Research Database (Denmark)

    Smith, Anders; Pedersen, Allan Schrøder

    2014-01-01

    Fuel cells have been the subject of intense research and development efforts for the past decades. Even so, the technology has not had its commercial breakthrough yet. This entry gives an overview of the technological challenges and status of fuel cells and discusses the most promising applications...... of the different types of fuel cells. Finally, their role in a future energy supply with a large share of fluctuating sustainable power sources, e.g., solar or wind, is surveyed....

  12. Fuel cycle

    International Nuclear Information System (INIS)

    Bahm, W.

    1989-01-01

    The situation of the nuclear fuel cycle for LWR type reactors in France and in the Federal Republic of Germany was presented in 14 lectures with the aim to compare the state-of-the-art in both countries. In addition to the momentarily changing fuilds of fuel element development and fueling strategies, the situation of reprocessing, made interesting by some recent developmnts, was portrayed and differences in ultimate waste disposal elucidated. (orig.) [de

  13. Nuclear fuel

    International Nuclear Information System (INIS)

    Azevedo, J.B.L. de.

    1980-01-01

    All stages of nuclear fuel cycle are analysed with respect to the present situation and future perspectives of supply and demand of services; the prices and the unitary cost estimation of these stages for the international fuel market are also mentioned. From the world resources and projections of uranium consumption, medium-and long term analyses are made of fuel availability for several strategies of use of different reactor types. Finally, the cost of nuclear fuel in the generation of electric energy is calculated to be used in the energetic planning of the electric sector. (M.A.) [pt

  14. Fuel assembly

    International Nuclear Information System (INIS)

    Nomata, Terumitsu.

    1993-01-01

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

  15. Fuel assembly

    International Nuclear Information System (INIS)

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

    1988-01-01

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

  16. Comparison of irradiation behavior of different uranium silicide dispersion fuel element designs

    International Nuclear Information System (INIS)

    Hofman, G.L.; Rest, J.; Snelgrove, J.L.

    1995-01-01

    Calculations of fuel swelling of U 3 SiAl-Al and U 3 Si 2 were performed for various dispersion fuel element designs. Breakaway swelling criteria in the form of critical fuel volume fractions were derived with data obtained from U 3 SiAl-Al plate irradiations. The results of the analysis show that rod-type elements remain well below the pillowing threshold. However, tubular fuel elements, which behave essentially like plates, will likely develop pillows or blisters at around 90% 235 U burnup. The U 3 Si 2 -Al compounds demonstrate stable swelling behavior throughout the entire burnup range for all fuel element designs

  17. Influence of Fuel-Matrix Interaction on the Deformation of U-Mo Dispersion Fuel

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, Ho Jin [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of); Kim, Yeon Soo [Argonne National Laboratory, Chicago (United States)

    2014-05-15

    In order to predict the fuel plate failure leading to breakaway swelling in the meat, an understanding of the effects of the fuel-matrix interaction behavior on the deformation of fuel meat is necessary. However, the effects of IL formation on the development of breakaway swelling have not been studied thoroughly. A mechanism that explains large pore growth that leads to breakaway swelling has not been included in the existing fuel performance models. In this study, the effect of the fuel-matrix interaction on large interfacial porosity development at the IL-Al interface is analyzed using both mechanistic correlations and observations from the post-irradiation examination results of U-Mo Dispersion fuels. The effects of fuel-matrix interaction on the fuel performance of U-Mo/Al Dispersion fuel were investigated. Fuel-matrix interaction bears the causes for breakaway swelling that can lead to a fuel failure under a high-power irradiation condition. Fission gas atoms are released from U-Mo particles to the interaction layer via diffusion and recoil. The fission gases released from the U-Mo and produced in the ILs are further released to the IL-Al interface by diffusion in the IL and recoil. Large pore formation at the IL-Al interface is attributed to the active diffusion of fission gas atoms in the ILs and coalescence between the small bubbles there. A model calculation showed that IL growth increases the probability of forming a breakaway swelling condition. ILs are connected to each other and the Al matrix decreases as ILs grow. When more ILs are interconnected, breakaway swelling can occur when the effective stress from the fission gas pressure in the IL-Al interfacial pore becomes larger than the yield strength of the Al matrix.

  18. Fuel element

    International Nuclear Information System (INIS)

    Kennedy, S.T.

    1982-01-01

    A nuclear reactor fuel element wherein a stack of nuclear fuel is prevented from displacement within its sheath by a retainer comprising a tube member which is radially expanded into frictional contact with the sheath by means of a captive ball within a tapered bore. (author)

  19. Nuclear fuel

    Energy Technology Data Exchange (ETDEWEB)

    Nakano, H [Power Reactor and Nuclear Fuel Development Corp., Tokyo (Japan)

    1976-10-01

    It is expected that nuclear power generation will reach 49 million kW in 1985 and 129 million kW in 1995, and the nuclear fuel having to be supplied and processed will increase in proportion to these values. The technical problems concerning nuclear fuel are presented on the basis of the balance between the benefit for human beings and the burden on the human beings. Recently, especially the downstream of nuclear fuel attracts public attention. Enriched uranium as the raw material for light water reactor fuel is almost monopolized by the U.S., and the technical information has not been published for fear of the diversion to nuclear weapons. In this paper, the present situations of uranium enrichment, fuel fabrication, transportation, reprocessing and waste disposal and the future problems are described according to the path of nuclear fuel cycle. The demand and supply of enriched uranium in Japan will be balanced up to about 1988, but afterwards, the supply must rely upon the early establishment of the domestic technology by centrifugal separation method. No problem remains in the fabrication of light water reactor fuel, but for the fabrication of mixed oxide fuel, the mechanization of the production facility and labor saving are necessary. The solution of the capital risk for the construction of the second reprocessing plant is the main problem. Japan must develop waste disposal techniques with all-out efforts.

  20. Fuel cells

    NARCIS (Netherlands)

    Veen, van J.A.R.; Janssen, F.J.J.G.; Santen, van R.A.

    1999-01-01

    The principles and present-day embodiments of fuel cells are discussed. Nearly all cells are hydrogen/oxygen ones, where the hydrogen fuel is usually obtained on-site from the reforming of methane or methanol. There exists a tension between the promise of high efficiency in the conversion of

  1. Fuel assembly

    International Nuclear Information System (INIS)

    Nakajima, Akiyoshi; Bessho, Yasunori; Aoyama, Motoo; Koyama, Jun-ichi; Hirakawa, Hiromasa; Yamashita, Jun-ichi; Hayashi, Tatsuo

    1998-01-01

    In a fuel assembly of a BWR type reactor in which a water rod of a large diameter is disposed at the central portion, the cross sectional area perpendicular to the axial direction comprises a region a of a fuel rod group facing to a wide gap water region to which a control rod is inserted, a region b of a fuel rod group disposed on the side of the wide gap water region other than the region a, a region d of a fuel rod group facing to a narrow gap water region and a region c of a fuel rod group disposed on the side of the narrow gap water region other than the region d. When comparing an amount of fission products contained in the four regions relative to that in the entire regions and average enrichment degrees of fuel rods for the four regions, the relative amount and the average enrichment degree of the fuel rod group of the region a is minimized, and the relative amount and the average enrichment degree of the fuel rod group in the region b is maximized. Then, reactor shut down margin during cold operation can be improved while flattening the power in the cross section perpendicular to the axial direction. (N.H.)

  2. Nuclear fuel

    International Nuclear Information System (INIS)

    Quinauk, J.P.

    1990-01-01

    Since 1985, Fragema has been marketing and selling the Advanced Fuel Assemby AFA whose main features are its zircaloy grids and removable top and bottom nozzles. It is this product, which exists for several different fuel assembly arrays and heights, that will be employed in the reactors at Daya Bay. Fragema employs gadolinium as the consumable poison to enable highperformance fuel management. More recently, the company has supplied fuel assemblies of the mixed-oxide(MOX) and enriched reprocessed uranium type. The reliability level of the fuel sold by Fragema is one of the highest in the world, thanks in particular to the excellence of the quality assurance and quality control programs that have been implemented at all stages of its design and manufacture

  3. Fuel assemblies

    International Nuclear Information System (INIS)

    Echigoya, Hironori; Nomata, Terumitsu.

    1983-01-01

    Purpose: To render the axial distribution relatively flat. Constitution: First nuclear element comprises a fuel can made of zircalloy i.e., the metal with less neutron absorption, which is filled with a plurality of UO 2 pellets and sealed by using a lower end plug, a plenum spring and an upper end plug by means of welding. Second fuel element is formed by substituting a part of the UO 2 pellets with a water tube which is sealed with water and has a space for allowing the heat expansion. The nuclear fuel assembly is constituted by using the first and second fuel elements together. In such a structure, since water reflects neutrons and decrease their leakage to increase the temperature, reactivity is added at the upper portion of the fuel assembly to thereby flatten the axial power distribution. Accordingly, stable operation is possible only by means of deep control rods while requiring no shallow control rods. (Sekiya, K.)

  4. La percepción de un grupo de hombres sobre la Diabetes Mellitus: contribuciones a la enfermería

    Directory of Open Access Journals (Sweden)

    Cleotilde García-Reza

    2014-12-01

    Full Text Available Comprender cómo los hombres perciben la enfermedad de la diabetes, del Estado de México. Estudio etnográfico a través de entrevistas a 15 hombres con diabetes de un programa de ejercicio, en un municipio mexiquense. El investigador principal permaneció en contacto con esta comunidad de hombres pertenecientes a un grupo de autoayuda por un periodo de 11 meses. Los datos se analizaron con la técnica del análisis de contenido para agruparse en categorías. Los hombres expresan en su cotidiano que, la enfermedad es una situación que libera sentimientos, fluctúan entre el miedo, inquietud, ira y tristeza. Dichas percepciones aproximan al profesional de enfermería a descubrir el mundo sociocultural constituido por creencias, actos e interacciones. El campo de enfermería necesita nuevos paradigmas a fin de incorporar una base epistémica para el cuidado de estos hombres que viven con diabetes Mellitus.

  5. Infancia, juegos y juguetes: contribuciones a un análisis histórico-cultural de la educación en Colombia (1930-1960)

    OpenAIRE

    Yeimy Cárdenas Palermo

    2013-01-01

    El artículo presenta avances y reflexiones acerca de la relación  entre  infancia,  juegos  y  juguetes  en  Colom-bia,  entre  los  años  treinta  y  sesenta  del  siglo  XX,  al considerarse  como  una  triada  paradigmática  para  el afianzamiento  de  las  nociones  modernas  de  infancia y  educación.  Desde  una  perspectiva  histórico-cultural, se  analiza  el  despliegue  de  discursos  que  deslindaron la relación juego-infancia como objeto particular de la educación  escolar  y  la ...

  6. Infancia, juegos y juguetes: contribuciones a un análisis histórico-cultural de la educación en Colombia (1930-1960

    Directory of Open Access Journals (Sweden)

    Yeimy Cárdenas Palermo

    2013-05-01

    Full Text Available El artículo presenta avances y reflexiones acerca de la relación  entre  infancia,  juegos  y  juguetes  en  Colom-bia,  entre  los  años  treinta  y  sesenta  del  siglo  XX,  al considerarse  como  una  triada  paradigmática  para  el afianzamiento  de  las  nociones  modernas  de  infancia y  educación.  Desde  una  perspectiva  histórico-cultural, se  analiza  el  despliegue  de  discursos  que  deslindaron la relación juego-infancia como objeto particular de la educación  escolar  y  la  relación  infancia-juguete  como objeto de sensibilización social frente a un ideal de vida infantil con profundas huellas de clase social. Palabras claveInfancia, juego, juguete, educación.

  7. Contribuciones de un dispositivo tangible para el aprendizaje de algunos conceptos de cinemática. Experiencia usando el Wiimote dentro del laboratorio de física

    Directory of Open Access Journals (Sweden)

    José Enrique Martínez Pérez

    2015-09-01

    Full Text Available http://dx.doi.org/10.5007/2175-7941.2015v32n3p870 Dado el avance de la tecnología tangible dentro del área de la interacción humano-computadora y lo costoso de adquirir y actualizar el equipamiento en los laboratorios de física de las instituciones de educación universitaria, en este trabajo se probó la factibilidad de usar un control de mando del juego de video de Wii llamado Wiimote, como dispositivo tangible, en una práctica de plano inclinado. Los resultados fueron satisfactorios y los estudiantes manifestaron que el diseño de la experiencia implantada contribuye al aprendizaje conceptual y procedimental relacionado con el plano inclinado. Los resultados parecen evidenciar la utilidad de la tecnología tangible en la construcción de representaciones más cercanas a los modelos de la ciencia y ayudar a los estudiantes a formarse imágenes mentales que pudieran ellos usar para nuevos retos. Se espera desarrollar este montaje con un diseño pedagógico.

  8. Contribuciones desde la interculturalidad a la educación de los pueblos originarios en Colombia: un ejemplo para la cultura Wayuu

    Directory of Open Access Journals (Sweden)

    Nadenka Beatriz Melo Brito

    2017-07-01

    Full Text Available La educación se enfrenta a la realidad de la heterogeneidad en las aulas de clase por múltiples razones y al ser Colombia un país que reconoce la diversidad cultural es necesario pensar en escenarios de educación intercultural donde se vaya más allá de reconocer la diversidad sino que se faciliten los espacios interculturales de interacción. Este artículo de reflexión toma como punto de partida el acervo bibliográfico del trabajo de tesis doctoral “Puentes entre conocimientos científicos y conocimientos ecológicos tradicionales: un estudio de aula en la comunidad wayuu” y da cuenta de las particularidades de los pueblos originarios como son el carácter local, su relación estrecha con la naturaleza de donde surgen los conocimientos ecológicos tradicionales; posteriormente enuncia algunas consideraciones del pueblo wayuu, asentado en la Península de La Guajira en cuanto a sus experiencias educativas. Finalmente se propone el diálogo intercultural como una prospectiva para que la educación ofrezca una respuesta a estos pueblos originarios.

  9. Violência contra a mulher: contribuições e limitações do sistema de informação Violencia contra la mujer: contribuciones y limitaciones del sistema de información Woman abuse: contribuitions and shortcomings of the information system

    Directory of Open Access Journals (Sweden)

    Irene Okabe

    2009-06-01

    Full Text Available O artigo tem por objetivo apresentar um breve panorama do sistema de informação em saúde, no monitoramento da violência contra a mulher, analisando em que medida cada fonte de dados pode contribuir para o real dimensionamento do evento e subsidiar o processo de tomada de decisão. Neste sentido, o texto apresenta os avanços e contribuições de cada base de dados oficial existente no setor de saúde, bem como as limitações que ainda persistem pela pouca sensibilidade e especificidade destes sistemas no monitoramento da violência contra a mulher. Discute-se também a necessidade de estudos para o aprofundamento da questão e uma política de informação à luz de gênero para análise e intervenção nos determinantes da violência contra a mulher, dada à magnitude e a gravidade do problema, não só para as mulheres, mas para a sociedade como um todo.El artículo tiene por objetivo presentar un breve panorama del sistema de información en salud en la actividad de monitoreo de la violencia contra la mujer, analizando de que forma cada medida y fuente de datos puede contribuir para el real dimensionamiento del evento y subsidiar el proceso de la toma de decisiones. En ese sentido, el texto presenta los avances y contribuciones de cada base de datos oficiales existentes en el sector de la salud, así como las limitaciones que todavía persisten por la poca sensibilidad y especificidad de estos sistemas en el monitoreo de la violencia contra la mujer. Se discute, también, la necesidad de realizar otros estudios para profundizar la cuestión y la elaboración de una política de información relacionada al género, para análisis e intervención en los determinantes de la violencia contra la mujer, dada la magnitud y la gravedad del problema no solo para las mujeres como para la sociedad como un todo.The purpose of this article is to present an overview of the health information system in monitoring woman abuse by analyzing the extent to

  10. Ambiente hospitalar saudável e sustentável na perspectiva ecossistêmica: contribuições da enfermagem Ambiente hospitalario saludable y sustentable en la perspectiva ecosistémica: contribuciones de la enfermería Healthy and sustainable clinical environment in the ecossystemic perspective: contributions of the nursing area

    Directory of Open Access Journals (Sweden)

    Jacqueline Sallete Dei Svaldi

    2010-09-01

    Full Text Available Este texto propõe uma discussão sobre o ambiente hospitalar saudável e sustentável destacando-se as contribuições da enfermagem nesse processo. As bases filosóficas encontram-se ancoradas na teoria ecossistêmica que analisa as sensibilidades necessárias para entender a natureza e os elementos estruturantes do ambiente/espaço hospitalar. Enfatiza-se a força aglutinadora das Unidades Produtivas que, de maneira interdependente e inter-relacionada, devem buscar o espaço sustentável e saudável através da cooperação, flexibilidade e parceria dos elementos constituintes. Reitera-se que a realimentação constante do conhecimento, envolvendo de forma sistêmica todas as Unidades Produtivas, pode facilitar as atualizações necessárias para acompanhar as modificações e transformações do espaço e, assim, do próprio cosmos. Compreende-se que o profissional de enfermagem, ao favorecer a construção de inter-relações em um processo de interconexões, pode ser o agente de transformação e representar os nós conectivos que tecem a rede viva da organização do ambiente hospitalar, levando-o à sustentabilidade e a ser mais saudável.Se propone una reflexión del ambiente hospitalario saludable y sustentable destacando las contribuciones de la enfermería en este proceso. Las bases filosóficas se encuentran arraigadas en la teoría ecosistémica que analiza las sensibilidades necesarias para entender la naturaleza y los elementos de estructura del ambiente/espacio hospitalario. Enfatiza la fuerza aglutinadora de las Unidades Productivas que, de manera dependiente y relacionada entre si, deben buscar el espacio sustentable y saludable a través de la cooperación, flexibilidad y unión. Reitera el feedback constante del conocimiento, envolviendo sistémicamente todas las Unidades Productivas, puede posibilitar las actualizaciones necesarias para acompañar las transformaciones del espacio/cosmos. El profesional de enfermería, al

  11. Infant mortality and prenatal care: contributions of the clinic in the light of Canguilhem and Foucault Mortalidad infantil y prenatal: contribuciones de la clínica bajo la perspectiva de Canguilhem y Foucault Mortalidade infantil e pré-natal: contribuições da clínica à luz de Canguilhem e Foucault

    Directory of Open Access Journals (Sweden)

    Paula Pereira de Figueiredo

    2012-02-01

    Full Text Available This review study aimed to verify how studies conducted in Brazil have related infant mortality to prenatal care and to present contributions of the clinic in the light of Canguilhem and Foucault for qualification of the care. An integrative literature review was conducted from searches in the databases SciELO, LILACS, MEDLINE and BDENF for the period 2000 to 2009. The relationship between infant mortality and prenatal care is related to the insufficient number of consultations or to the quality of the care provided. Even when the number of and routine consultations in the prenatal care were adequate, avoidable deaths were present. For the qualification of prenatal care, it is suggested that the clinical knowledge and other elements that comprise the process of human living are considered, in order that the clinical view is enlarged and articulated to the technologies available in the health system and, together, they are able to contribute to the reduction of infant mortality in Brazil.Este estudio de revisión tuvo por objetivo verificar cómo investigaciones realizadas en Brasil relacionan la mortalidad infantil y el prenatal, y presentar contribuciones de la clínica bajo el marco teórico de Canguilhem y Foucault para la calificación de la asistencia. Se realizó una revisión integradora de la literatura a partir de búsquedas en las bases de datos SciELO, LILACS, MEDLINE y BDENF, en el período de 2000 a 2009. La relación entre la mortalidad infantil y el prenatal se refiere al número insuficiente de consultas o a la calidad de la atención prestada. Mismo cuando el número y la rutina de consultas en el prenatal fueron adecuadas, las muertes evitables estuvieron presentes. Para la calificación de la asistencia ofrecida, se sugiere que sean considerados el conocimiento clínico y los demás elementos componentes del proceso del vivir humano, con la intención de que la perspectiva clínica sea ampliada y articulada a las tecnolog

  12. Evaluation of Test Methodologies for Dissolution and Corrosion of Al-SNF

    International Nuclear Information System (INIS)

    Wiersma, B.J.; Mickalonis, J.I.; Louthan, M.R.

    1998-09-01

    The performance of aluminum-based spent nuclear fuel (Al-SNF) in the repository will differ from that of the commercial nuclear fuels and the high level waste glasses. The program consists of evaluating three test methods

  13. Study of Irradiation Effect onto Uranium silicide Fuel

    International Nuclear Information System (INIS)

    Suparjo

    1998-01-01

    The irradiation effect onto the U 3 Si-Al and U 3 Si 2 -Al dispersion type of fuel element has been studied. The fuel material performs swelling during irradiation due to boehmite (Al 2 O 3 (H 2 O)) formation in which might occurs inside the meat and on the cladding surface, the interaction between the fuel and aluminium matrix that produce U(Al,Si) 3 phase, and the formation of fission gas bubble inside the fuel. At a constant fission density, the U 3 Si-Al fuel swelling is higher than that of U 3 Si 2 -Al fuel. The swellings of both fuels increase with the increasing of fission density. The difference of swelling behavior was caused by formation of large bubble gases generated from fission product of U 3 Si fuel and distributed non-uniformly over all of fuel zone. On the other hand, the U 3 Si 2 fission produced small bubble gases, and those were uniformly distributed. The growth rate of fission gas bubble in the U 3 Si fuel has shown high diffusivity, transformation into amorph material and thus decrease its mechanical strength

  14. High density dispersion fuel

    International Nuclear Information System (INIS)

    Hofman, G.L.

    1996-01-01

    A fuel development campaign that results in an aluminum plate-type fuel of unlimited LEU burnup capability with an uranium loading of 9 grams per cm 3 of meat should be considered an unqualified success. The current worldwide approved and accepted highest loading is 4.8 g cm -3 with U 3 Si 2 as fuel. High-density uranium compounds offer no real density advantage over U 3 Si 2 and have less desirable fabrication and performance characteristics as well. Of the higher-density compounds, U 3 Si has approximately a 30% higher uranium density but the density of the U 6 X compounds would yield the factor 1.5 needed to achieve 9 g cm -3 uranium loading. Unfortunately, irradiation tests proved these peritectic compounds have poor swelling behavior. It is for this reason that the authors are turning to uranium alloys. The reason pure uranium was not seriously considered as a dispersion fuel is mainly due to its high rate of growth and swelling at low temperatures. This problem was solved at least for relatively low burnup application in non-dispersion fuel elements with small additions of Si, Fe, and Al. This so called adjusted uranium has nearly the same density as pure α-uranium and it seems prudent to reconsider this alloy as a dispersant. Further modifications of uranium metal to achieve higher burnup swelling stability involve stabilization of the cubic γ phase at low temperatures where normally α phase exists. Several low neutron capture cross section elements such as Zr, Nb, Ti and Mo accomplish this in various degrees. The challenge is to produce a suitable form of fuel powder and develop a plate fabrication procedure, as well as obtain high burnup capability through irradiation testing

  15. Extended storage of spent fuel

    International Nuclear Information System (INIS)

    1992-10-01

    This document is the final report on the IAEA Co-ordinated Research Programme on the Behaviour of Spent Fuel and Storage Facility Components during Long Term Storage (BEFAST-II, 1986-1991). It contains the results on wet and dry spent fuel storage technologies obtained from 16 organizations representing 13 countries who participated in the co-ordinated research programme. Considerable quantities of spent fuel continue to arise and accumulate. Many countries are investigating the option of extended spent fuel storage prior to reprocessing or fuel disposal. Wet storage continues to predominate as an established technology with the construction of additional away-from-reactor storage pools. However, dry storage is increasingly used with most participants considering dry storage concepts for the longer term. Depending on the cladding type options of dry storage in air or inert gas are proposed. Dry storage is becoming widely used as a supplement to wet storage for zirconium alloy clad oxide fuels. Storage periods as long as under wet conditions appear to be feasible. Dry storage will also continue to be used for Al clad and Magnox type fuel. Enhancement of wet storage capacity will remain an important activity. Rod consolidation to increase wet storage capacity will continue in the UK and is being evaluated for LWR fuel in the USA, and may start in some other countries. High density storage racks have been successfully introduced in many existing pools and are planned for future facilities. For extremely long wet storage (≥50 years), there is a need to continue work on fuel integrity investigations and LWR fuel performance modelling. it might be that pool component performance in some cases could be more limiting than the FA storage performance. It is desirable to make concerted efforts in the field of corrosion monitoring and prediction of fuel cladding and poll component behaviour in order to maintain good experience of wet storage. Refs, figs and tabs

  16. Fuel cells:

    DEFF Research Database (Denmark)

    Sørensen, Bent

    2013-01-01

    A brief overview of the progress in fuel cell applications and basic technology development is presented, as a backdrop for discussing readiness for penetration into the marketplace as a solution to problems of depletion, safety, climate or environmental impact from currently used fossil and nucl......A brief overview of the progress in fuel cell applications and basic technology development is presented, as a backdrop for discussing readiness for penetration into the marketplace as a solution to problems of depletion, safety, climate or environmental impact from currently used fossil...... and nuclear fuel-based energy technologies....

  17. Fuel assemblies

    International Nuclear Information System (INIS)

    Nakatsuka, Masafumi.

    1979-01-01

    Purpose: To prevent scattering of gaseous fission products released from fuel assemblies stored in an fbr type reactor. Constitution; A cap provided with means capable of storing gas is adapted to amount to the assembly handling head, for example, by way of threading in a storage rack of spent fuel assemblies consisting of a bottom plate, a top plate and an assembly support mechanism. By previously eliminating the gas inside of the assembly and the cap in the storage rack, gaseous fission products upon loading, if released from fuel rods during storage, are stored in the cap and do not scatter in the storage rack. (Horiuchi, T.)

  18. Attempt to produce silicide fuel elements in Indonesia

    International Nuclear Information System (INIS)

    Soentono, S.; Suripto, A.

    1991-01-01

    After the successful experiment to produce U 3 Si 2 powder and U 3 Si 2 -Al fuel plates using depleted U and Si of semiconductor quality, silicide fuel was synthesized using x -Al available at the Fuel Element Production Installation (FEPI) at Serpong, Indonesia. Two full-size U 3 Si 2 -Al fuel elements, having similar specifications to the ones of U 3 O 8 -Al for the RSG-GAS (formerly known as MPR-30), have been produced at the FEPI. All quality controls required have been imposed to the feeds, intermediate, as well as final products throughout the production processes of the two fuel elements. The current results show that these fuel elements are qualified from fabrication point of view, therefore it is expected that they will be permitted to be tested in the RSG-GAS, sometime by the end of 1989, for normal (∝50%) and above normal burn-up. (orig.)

  19. Single step synthesis of GdAlO3 powder

    International Nuclear Information System (INIS)

    Sinha, Amit; Nair, S.R.; Sinha, P.K.

    2011-01-01

    Research highlights: → First report on direct formation of GdAlO 3 powder using a novel combustion process. → Study of combustion characteristics of Gd(NO 3 ) 3 and Al(NO 3 ) 3 towards three fuels. → Preparation of highly sinterable GdAlO 3 powders through fuel-mixture approach. → Significant reduction in energy consumption for production of GdAlO 3 sintered body. - Abstract: A novel method for preparation of nano-crystalline gadolinium aluminate (GdAlO 3 ) powder, based on combustion synthesis, is reported. It was observed that aluminium nitrate and gadolinium nitrate exhibit different combustion characteristics with respect to urea, glycine and β-alanine. While urea was proven to be a suitable fuel for direct formation of crystalline α-Al 2 O 3 from its nitrate, glycine and β-alanine are suitable fuels for gadolinium nitrate for preparation of its oxide after combustion reaction. Based on the observed chemical characteristics of gadolinium and aluminium nitrates with respect to above mentioned fuels for the combustion reaction, the fuel mixture composition could be predicted that could lead to phase pure perovskite GdAlO 3 directly after the combustion reaction without any subsequent calcination step. The use of single fuel, on the other hand, leads to formation of amorphous precursor powders that call for subsequent calcination for the formation of crystalline GdAlO 3 . The powders produced directly after combustion reactions using fuel mixtures were found to be highly sinterable. The sintering of the powders at 1550 o C for 4 h resulted in GdAlO 3 with sintered density of more than 95%. T.D.

  20. Fuel behaviour

    International Nuclear Information System (INIS)

    Fodor, M.; Matus, L.; Vigassy, J.

    1987-11-01

    A short summary of the main critical points in fuel performance of nuclear power reactors from chemical and mechanical point of view is given. A schedule for a limited research program is included. (author) 17 refs

  1. Fuel cells

    International Nuclear Information System (INIS)

    Niederdoeckl, J.

    2001-01-01

    Europe has at present big hopes on the fuel cells technology, in comparison with other energy conversion technologies, this technology has important advantages, for example: high efficiency, very low pollution and parallel use of electric and thermal energy. Preliminary works for fuel cells developing and its commercial exploitation are at full speed; until now the European Union has invested approx. 1.7 billion Schillings, 60 relevant projects are being executed. The Austrian industry is interested in applying this technique to drives, thermal power stations and the miniature fuel cells as replacement of batteries in electronic products (Notebooks, mobile telephones, etc.). A general description of the historic development of fuel cells including the main types is given as well as what is the situation in Austria. (nevyjel)

  2. Fuel assembly

    International Nuclear Information System (INIS)

    Ishibashi, Yoko; Aoyama, Motoo; Oyama, Jun-ichi.

    1995-01-01

    Burnable poison-incorporating fuel rods of a first group are disposed in a region in adjacent with a water rod having a large diameter (neutron moderator rod) disposed to the central portion of a fuel assembly. Burnable poison-incorporating fuel rods of a second group are disposed to a region other than peripheral zone in adjacent with a channel box and corners positioned at an inner zone, in adjacent with the channel box. The average concentration of burnable poisons of the burnable poison-incorporating fuel rods of the first group is made greater than that of the second group. With such a constitution, when the burnable poisons of the first group are burnt out, the burnable poisons of the second group are also burnt out at the same time. Accordingly, an amount of burnable poisons left unburnt at the final stage of the operation cycle is reduced, to improve the reactivity. This can improve the economical property. (I.N.)

  3. Irradiation behavior of uranium oxide - Aluminum dispersion fuel

    International Nuclear Information System (INIS)

    Hofman, Gerard L.; Rest, Jeffrey; Snelgrove, James L.

    1996-01-01

    An oxide version of the DART code has been generated in order to assess the irradiation behavior of UO 2 -Al dispersion fuel. The aluminum-fuel interaction models were developed based on U 3 O 8 -Al irradiation data. Deformation of the fuel element occurs due to fuel particle swelling driven by both solid and gaseous fission products and as a consequence of the interaction between the fuel particles and the aluminum matrix. The calculations show that, with the assumption that the correlations derived from U 3 O 8 are valid for UO 2 , the LEU UO 2 -Al with a 42% fuel volume loading (4 g U/cm 3 ) irradiated at fuel temperatures greater than 413 K should undergo breakaway swelling at core burnups greater than about 1.12 x 10 27 fissions m -3 (∼63% 235 U burnup). (author)

  4. Irradiation behavior of uranium oxide-aluminum dispersion fuel

    International Nuclear Information System (INIS)

    Hofman, G.L.; Rest, J.; Snelgrove, J.L.

    1996-01-01

    An oxide version of the DART code has been generated in order to assess the irradiation behavior of UO 2 -Al dispersion fuel. The aluminum-fuel interaction models were developed based on U 3 O 8 -Al irradiation data. Deformation of the fuel element occurs due to fuel particle swelling driven by both solid and gaseous fission products, as well as a consequence of the interaction between the fuel particles and the aluminum matrix. The calculations show, that with the assumption that the correlations derived from U 3 O 8 are valid for UO 2 , the LEU UO 2 -Al with a 42% fuel volume loading (4 gm/cc) irradiated at fuel temperatures greater than 413 K should undergo breakaway swelling at core burnups greater than about 1.12 x 10 27 fissions m -3 (∼ 63% 235 U burnup)

  5. Fuel element

    International Nuclear Information System (INIS)

    Armijo, J.S.

    1976-01-01

    A fuel element for nuclear reactors is proposed which has a higher corrosion resisting quality in reactor operations. The zirconium alloy coating around the fuel element (uranium or plutonium compound) has on its inside a protection layer of metal which is metallurgically bound to the substance of the coating. As materials are namned: Alluminium, copper, niobium, stainless steel, and iron. This protective metallic layer has another inner layer, also metallurgically bound to its surface, which consists usually of a zirconium alloy. (UWI) [de

  6. Study of fuel element characteristic of SM and SMP (SM-PRIMA) fuel assemblies

    International Nuclear Information System (INIS)

    Klinov, A.V.; Kuprienko, V.A.; Lebedev, V.A.; Makhin, V.M.; Tuchnin, L.M.; Tsykanov, V.A.

    1999-01-01

    The paper discusses the techniques and results of reactor tests and post-reactor investigations of the SM reactor fuel elements and fuel elements developed in the process of designing the specialized PRIMA test reactor with the SM reactor fuel elements used as a prototype and which are referred to as the SMP fuel elements. The behavior of fuel elements under normal operating conditions and under deviation from normal operating conditions was studied to verify the calculation techniques, to check the calculation results during preparation of the SM reactor safety substantiation report and to estimate the possibility of using such fuel elements in other projects. During tests of fuel rods under deviation from normal operating conditions their advantages were shown over fuel elements, the components of which were produced using the Al-based alloys. (author)

  7. Fuel assembly

    International Nuclear Information System (INIS)

    Ueda, Sei; Ando, Ryohei; Mitsutake, Toru.

    1995-01-01

    The present invention concerns a fuel assembly suitable to a BWR-type reactor and improved especially with the nuclear characteristic, heat performance, hydraulic performance, dismantling or assembling performance and economical property. A part of poison rods are formed as a large-diameter/multi-region poison rods having a larger diameter than a fuel rod. A large number of fuel rods are disposed surrounding a large diameter water rod and a group of the large-diameter/multi-region poison rods in adjacent with the water rod. The large-diameter water rod has a burnable poison at the tube wall portion. At least a portion of the large-diameter poison rods has a coolant circulation portion allowing coolants to circulate therethrough. Since the large-diameter poison rods are disposed at a position of high neutron fluxes, a large neutron multiplication factor suppression effect can be provided, thereby enabling to reduce the number of burnable poison rods relative to fuels. As a result, power peaking in the fuel assembly is moderated and a greater amount of plutonium can be loaded. In addition the flow of cooling water which tends to gather around the large diameter water rod can be controlled to improve cooling performance of fuels. (N.H.)

  8. Jane Austen y C. S. Lewis: de la literatura al cine. Análisis de transposición

    Directory of Open Access Journals (Sweden)

    Mercedes Sarapura Sarapura

    2016-11-01

    Full Text Available Esta es una propuesta de análisis de transposición de la literatura al cine de la novela Orgullo y Prejuicio, de Jane Austen, y del ensayo Una pena observada, de C. S. Lewis. El primer propósito en ambos casos es ahondar en los nuevos aportes de la última versión cinematográfica de la novela de Austen, así como en las características y cualidades de la versión fílmica del cuaderno de anotaciones de C. S. Lewis, a partir de las contribuciones teóricas de autores como Gerard Genette, Georffrey Wagner, Brian Mcfarlane, entre otros. El segundo objetivo se orienta al reconocimiento del intercambio entre el lenguaje cinematográfico y literario como un proceso representativo de la sociedad actual. El hecho de que las adaptaciones (históricamente vistas con gran escepticismo sean ahora continuamente realizadas y acogidas por el público, insta a una revisión y profundización de los estudios que se han hecho al respecto con el fin de conocer la situación actual de la relación existente entre cine y literatura, sus posibilidades creativas, las expectativas de las audiencias, los prejuicios y recelos de los expertos, etc.

  9. Analysis of UO{sub 2}-BeO fuel under transient using fuel performance code

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-11-01

    Recent research has appointed the need to replace the classic fuel concept, used in light water reactors. Uranium dioxide has a weak point due to the low thermal conductivity, that produce high temperatures on the fuel. The ceramic composite fuel formed of uranium dioxide (UO{sub 2}), with the addition of beryllium oxide (BeO), presents high thermal conductivity compared with UO{sub 2}. The oxidation of zirconium generates hydrogen gas that can create a detonation condition. One of the preferred options are the ferritic alloys formed of iron-chromium and aluminum (FeCrAl), that should avoid the hydrogen release due to oxidation. In general, the FeCrAl alloys containing 10 - 20Cr, 3 - 5Al, and 0 - 0.12Y in weight percent. The FeCrAl alloys should exhibit a slow oxidation kinetics due to chemical composition. Resistance to oxidation in the presence of steam is improved as a function of the content of chromium and aluminum. In this way, the thermal and mechanical properties of the UO{sub 2}-BeO-10%vol, composite fuel were coupled with FeCrAl alloys and added to the fuel codes. In this work, we examine the fuel rod behavior of UO{sub 2}-10%vol-BeO/FeCrAl, including a simulated transient of reactivity. The fuels behavior shown reduced temperature with UO{sub 2}-BeO/Zr, UO{sub 2}-BeO/FeCrAl also were compared with UO{sub 2}/Zr system. The case reactivity initiated accident analyzed, reproducing the fuel rod called VA-1 using UO{sub 2}/Zr alloys and compared with UO{sub 2}-BeO/FeCrAl. (author)

  10. Status of LEU fuel development and conversion of NRU

    International Nuclear Information System (INIS)

    Sears, D.F.; Herbert, L.N.; Vaillancourt, K.D.

    1989-11-01

    The status of the low-enrichment uranium (LEU) fuel development and NRU conversion program at Chalk River Nuclear Laboratories is reviewed. Construction of a new fuel fabrication facility is essentially completed and installation of LEW fuel manufacturing equipment has begun. The irradiation of 31 prototype Al-61 wt% U 3 Si dispersion fuel rods, approximately one third of a full NRU core, is continuing without incident. Recent post-irradiation examination of spent fuel rods revealed that the prototype LEU fuel achieved the design burnup (80 at%) in excellent condition, confirming that the Al-U 3 Si 2 dispersion fuel to complement out Al-U 3 Si capability. Three full-size NRU rods containing Al-U 3 Si 2 dispersion fuel have been fabricated for a qualification irradiation in NRU. Post-irradiation examinations of mini-elements containing Al-U 3 Si 2 fuel revealed that the U 3 Si 2 behaved similarly to U 3 Si 2 fuel revealed that the U 3 Si 2 particles and the aluminum matrix, and fission gas bubbles up to 10 μm in diameter, could be seen in the particles after 60 at% and 80 at% burnup. The mini-elements contained a variety of silicide particle sizes; however, no significant swelling dependence on particle size distribution was observed

  11. Development of the fabrication technology of the simulated DUPIC fuel

    International Nuclear Information System (INIS)

    Kang, Kweon Ho; Yang, M. S.; Bae, K. K. and others

    2000-06-01

    It is important to get basic data to analysis physical properties, behavior in reactor and performance of the DUPIC fuel because physical properties of the DUPIC fuel is different from the commercial UO 2 fuel. But what directly measures physical properties et al. of DUPIC fuel being resinterred simulated spent fuel through OREOX process is very difficult in laboratory owing to its high level radiation. Then fabrication of simulated DUPIC fuel is needed to measure its properties. In this study, processes on powder treatment, OREOX, compaction and sintering to fabricate simulated DUPIC fuel using simulated spent fuel are discribed. To fabricate simulated DUPIC fuel, the powder from 3 times OREOX and 5 times attrition milling simulated spent fuel is compacted with 1.3 ton/cm 2 . Pellets are sintered in 100% H 2 atmosphere over 10 h at 1800 deg C. Sintered densities of pellets are 10.2-10.5 g/cm 3

  12. Fuel rods

    International Nuclear Information System (INIS)

    Adachi, Hajime; Ueda, Makoto

    1985-01-01

    Purpose: To provide a structure capable of measuring, in a non-destructive manner, the releasing amount of nuclear gaseous fission products from spent fuels easily and at a high accuracy. Constitution: In order to confirm the integrity and the design feasibility of a nuclear fuel rod, it is important to accurately determine the amount of gaseous nuclear fission products released from nuclear pellets. In a structure where a plurality of fuel pellets are charged in a fuel cladding tube and retained by an inconel spring, a hollow and no-sealed type spacer tube made of zirconium or the alloy thereof, for example, not containing iron, cobalt, nickel or manganese is formed between the spring and the upper end plug. In the fuel rod of such a structure, by disposing a gamma ray collimator and a gamma ray detector on the extension of the spacer pipe, the gamma rays from the gaseous nuclear fission products accumulated in the spacer pipe can be detected while avoiding the interference with the induction radioactivity from inconel. (Kamimura, M.)

  13. Fuel rods

    International Nuclear Information System (INIS)

    Hattori, Shinji; Kajiwara, Koichi.

    1980-01-01

    Purpose: To ensure the safety for the fuel rod failures by adapting plenum springs to function when small forces such as during transportation of fuel rods is exerted and not to function the resilient force when a relatively great force is exerted. Constitution: Between an upper end plug and a plenum spring in a fuel rod, is disposed an insertion member to the lower portion of which is mounted a pin. This pin is kept upright and causes the plenum spring to function resiliently to the pellets against the loads due to accelerations and mechanical vibrations exerted during transportation of the fuel rods. While on the other hand, if a compression force of a relatively high level is exerted to the plenum spring during reactor operation, the pin of the insertion member is buckled and the insertion member is inserted to the inside of the plenum spring, whereby the pellets are allowed to expand freely and the failures in the fuel elements can be prevented. (Moriyama, K.)

  14. Fuel assembly

    International Nuclear Information System (INIS)

    Abe, Hideaki; Sakai, Takao; Ishida, Tomio; Yokota, Norikatsu.

    1992-01-01

    The lower ends of a plurality of plate-like shape memory alloys are secured at the periphery of the upper inside of the handling head of a fuel assembly. As the shape memory alloy, a Cu-Zn alloy, a Ti-Pd alloy or a Fe-Ni alloy is used. When high temperature coolants flow out to the handling head, the shape memory alloy deforms by warping to the outer side more greatly toward the upper portion thereof with the temperature increase of the coolants. As the result, the shape of the flow channel of the coolants is changed so as to enlarge at the exit of the upper end of the fuel assembly. Then, the pressure loss of the coolants in the fuel assembly is decreased by the enlargement. Accordingly, the flow rate of the coolants in the fuel assembly is increased to lower the temperature of the coolants. Further, high temperature coolants and low temperature coolants are mixed sufficiently just above the fuel assembly. This can suppress the temperature fluctuation of the mixed coolants in the upper portion of the reactor core, thereby enabling to decrease a fatigue and failures of the structural components in the upper portion of the reactor core. (I.N.)

  15. Fuel assembly

    International Nuclear Information System (INIS)

    Sano, Hiroki; Fushimi, Atsushi; Tominaga, Kenji; Aoyama, Motoo; Ishii, Kazuya.

    1997-01-01

    In burnable poison-incorporated uranium fuels of a BWR type reactor, the compositional ratio of isotopes of the burnable poisons is changed so as to increase the amount of those having a large neutron absorbing cross sectional area. For example, if the ratio of Gd-157 at the same burnable poison enrichment degree is made greater than the natural ratio, this gives the same effect as the increase of the enrichment degree per one fuel rod, thereby providing an effect of reducing a surplus reactivity. Gadolinium, hafnium and europium as burnable poisons have an absorbing cross sectional area being greater in odd numbered nuclei than in even numbered nuclei, on the contrary, boron has a cross section being greater in even numbered nucleus than odd numbered nuclei. Accordingly, if the ratio of isotopes having greater cross section at the same burnable poison enrichment degree is made greater than the natural ratio, surplus reactivity at the initial stage of the burning can be reduced without greatly increasing the amount of burnable poison-incorporated uranium fuels, fuel loading amount is not reduced and the fuel economy is not worsened. (N.H.)

  16. Canadian power reactor fuel

    International Nuclear Information System (INIS)

    Page, R.D.

    1976-03-01

    The following subjects are covered: the basic CANDU fuel design, the history of the bundle design, the significant differences between CANDU and LWR fuel, bundle manufacture, fissile and structural materials and coolants used in the CANDU fuel program, fuel and material behaviour, and performance under irradiation, fuel physics and management, booster rods and reactivity mechanisms, fuel procurement, organization and industry, and fuel costs. (author)

  17. CANDU fuel

    International Nuclear Information System (INIS)

    MacEwan, J.R.; Notley, M.J.F.; Wood, J.C.; Gacesa, M.

    1982-09-01

    The direction of CANDU fuel development was set in 1957 with the decision to build pressure tube reactors. Short - 50 cm long - rodded bundles of natural UO 2 clad in Zircaloy were adopted to facilitate on-power fuelling to improve uranium utilization. Progressive improvements were made during 25 years of development, involving 650 man years and 180 million dollars. Today's CANDU bundle is based on the knowledge gained from extensive irradiation testing and experience in power reactors. The main thrust of future development is to demonstrate that the present bundle is suitable, with minor modifications, for thorium fuels

  18. Comunes urbanos: de la gestión colectiva al derecho a la ciudad

    Directory of Open Access Journals (Sweden)

    Mauro Castro-Coma

    2016-01-01

    Full Text Available Existe un creciente interés y una emergente literatura académica en los estudios urbanos sobre los comunes y su aplicación. Por un lado, destacan aquellas aportaciones que aplican al ámbito urbano, los estudios de Elinor Ostrom sobre las formas de autogestión de los recursos naturales de uso común. Por el otro, la literatura crítica sobre el neoliberalismo, las nuevas formas de acumulación por desposesión y las resistencias a ellas en forma de movimientos sociales también han abordado los comunes en la ciudad desde diferentes perspectivas de origen marxista. En este trabajo se ordenan y se analizan las contribuciones de ambas aproximaciones, sus puntos críticos, así como sus posibles complementariedades, para avanzar hacia una mejor conceptualización y una futura agenda de investigación sobre los comunes urbanos.

  19. Alternate fuels; Combustibles alternos

    Energy Technology Data Exchange (ETDEWEB)

    Romero Paredes R, Hernando; Ambriz G, Juan Jose [Universidad Autonoma Metropolitana. Iztapalapa (Mexico)

    2003-07-01

    In the definition and description of alternate fuels we must center ourselves in those technological alternatives that allow to obtain compounds that differ from the traditional ones, in their forms to be obtained. In this article it is tried to give an overview of alternate fuels to the conventional derivatives of petroleum and that allow to have a clear idea on the tendencies of modern investigation and the technological developments that can be implemented in the short term. It is not pretended to include all the tendencies and developments of the present world, but those that can hit in a relatively short term, in accordance with agreed with the average life of conventional fuels. Nevertheless, most of the conversion principles are applicable to the spectrum of carbonaceous or cellulosic materials which are in nature, are cultivated or wastes of organic origin. Thus one will approach them in a successive way, the physical, chemical and biological conversions that can take place in a production process of an alternate fuel or the same direct use of the fuel such as burning the sweepings derived from the forests. [Spanish] En la definicion y descripcion de combustibles alternos nos debemos centrar en aquellas alternativas tecnologicas que permitan obtener compuestos que difieren de los tradicionales, al menos en sus formas de ser obtenidos. En este articulo se pretende dar un panorama de los combustibles alternos a los convencionales derivados del petroleo y que permita tener una idea clara sobre las tendencias de la investigacion moderna y los desarrollos tecnologicos que puedan ser implementados en el corto plazo. No se pretende abarcar todas las tendencias y desarrollos del mundo actual, sino aquellas que pueden impactar en un plazo relativamente corto, acordes con la vida media de los combustibles convencionales. Sin embargo, la mayor parte de los principios de conversion son aplicables al espectro de materiales carbonaceos o celulosicos los cuales se

  20. Fuel performance of rod-type research reactor fuel using a centrifugally atomized U-Mo powder

    International Nuclear Information System (INIS)

    Ryu, Ho Jin; Park, Jong Man; Lee, Yoon Sang; Kim, Chang Kyu

    2009-01-01

    A low enriched uranium nuclear fuel for research reactors has been developed in order to replace a highly enriched uranium fuel according to the non-proliferation policy under the reduced enrichment for research and test reactors (RERTR) program. In KAERI, a rod-type U 3 Si dispersion fuel has been developed for a localization of the HANARO fuel and a U 3 Si/Al dispersion fuel of 3.15 gU/cc has been used at HANARO as a driver fuel since 2005. Although uranium silicide dispersion fuels such as U 3 Si 2 /Al and U 3 Si/Al are being used widely, high uranium density dispersion fuels (8-9 g/cm 3 ) are required for some high performance research reactors. U-Mo alloys have been considered as one of the most promising uranium alloys for a dispersion fuel due to their good irradiation performance. An international qualification program on U-Mo fuel to replace a uranium silicide dispersion fuel with a U-Mo dispersion fuel has been carried out

  1. Effect of irradiation power and time on ultrasound assisted co-precipitation of nanostructured CuO–ZnO–Al2O3 over HZSM-5 used for direct conversion of syngas to DME as a green fuel

    International Nuclear Information System (INIS)

    Allahyari, Somaiyeh; Haghighi, Mohammad; Ebadi, Amanollah; Hosseinzadeh, Shahin

    2014-01-01

    Graphical abstract: Nanostructured CuO–ZnO–Al 2 O 3 /HZSM-5 catalyst has been prepared by an ultrasound-assisted co-precipitation hybrid method. Effect of power and irradiation time have been studied by changing the time (30–45–60 min) and power of sonication (50–100–150 W) during the synthesis which lead to different physiochemical properties of the catalyst. The XRD, FESEM, EDX, FTIR and BET analyses exhibited smaller particles with higher surface area and less population of particle aggregates at longer and highly irradiated catalysts. Study on the performance of investigated catalysts in direct synthesis of DME from syngas showed ultrasound-assisted co-precipitated synthesized catalysts have superior reactivity and stability compared with non-sonicated catalyst. Among sonicated catalysts, with increasing power and time of irradiation, the catalyst represents higher activity and DME selectivity. - Highlights: • Synthesis of CuO–ZnO–Al 2 O 3 /HZSM-5 by ultrasound assisted co-precipitation method. • Significant changes in morphology and surface area after ultrasound irradiations. • Smaller dispersed particle aggregates in longer and more intense irradiated catalysts. • Improvement in reactivity and stability of the longer and more intense ultrasound irradiated CZAZ catalyst. - Abstract: Nanostructured CuO–ZnO–Al 2 O 3 /HZSM-5 catalyst has been prepared by an ultrasound-assisted co-precipitation hybrid method. The effect of irradiation power and irradiation time have been studied by changing time (30, 45, 60 min) and power of the sonication (50, 100, 150 W) during the synthesis which led to different physiochemical properties of the nanocatalyst. The XRD, FESEM, EDX, FTIR and BET analyses exhibited smaller particles with higher surface area and less population of particle aggregates at longer and highly irradiated nanocatalysts. The nanocatalyst irradiated at 150 W for 60 min (the longest irradiation time and the most intense power

  2. Performance evaluation of large U-Mo particle dispersed fuel irradiated in HANARO

    International Nuclear Information System (INIS)

    Ryu, Ho Jin; Park, Jong Man; Oh, Seok Jin; Jang, Se Jung; Yu, Byung Ok; Lee, Choong Seong; Seo, Chul Gyo; Chae, Hee Taek; Kim, Chang Kyu

    2008-01-01

    U-Mo/Al dispersion fuel is being developed as advanced fuel for research reactors. Irradiation behavior of U-Mo/Al dispersion fuel has been studied to evaluate its fuel performance. One of the performance limiting factors is a chemical interaction between the U-Mo particle and the Al matrix because the thermal conductivity of fuel meat is decreased with the interaction layer growth. In order to overcome the interaction problem, large-sized U-Mo particles were fabricated by controlling the centrifugal atomization conditions. The fuel performance behavior of U-Mo/Al dispersion fuel was estimated by using empirical models formulated based on the microstructural analyses of the post-irradiation examination (PIE) on U-Mo/Al dispersion fuel irradiated in HANARO reactor. Temperature histories of U-Mo/Al dispersion fuel during irradiation tests were estimated by considering the effect of an interaction layer growth on the thermal conductivity of the fuel meat. When the fuel performances of the dispersion fuel rods containing U-Mo particles with various sizes were compared, fuel temperature was decreased as the average U-Mo particle size was increases. It was found that the dispersion of a larger U-Mo particle was effective for mitigating the thermal degradation which is associated with an interaction layer growth. (author)

  3. Fuels characterization studies. [jet fuels

    Science.gov (United States)

    Seng, G. T.; Antoine, A. C.; Flores, F. J.

    1980-01-01

    Current analytical techniques used in the characterization of broadened properties fuels are briefly described. Included are liquid chromatography, gas chromatography, and nuclear magnetic resonance spectroscopy. High performance liquid chromatographic ground-type methods development is being approached from several directions, including aromatic fraction standards development and the elimination of standards through removal or partial removal of the alkene and aromatic fractions or through the use of whole fuel refractive index values. More sensitive methods for alkene determinations using an ultraviolet-visible detector are also being pursued. Some of the more successful gas chromatographic physical property determinations for petroleum derived fuels are the distillation curve (simulated distillation), heat of combustion, hydrogen content, API gravity, viscosity, flash point, and (to a lesser extent) freezing point.

  4. Alternative Fuels Data Center: Ethanol Fueling Stations

    Science.gov (United States)

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

  5. Alternative Fuels Data Center: Biodiesel Fueling Stations

    Science.gov (United States)

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

  6. Fuels processing for transportation fuel cell systems

    Science.gov (United States)

    Kumar, R.; Ahmed, S.

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

  7. Fuel assembly

    International Nuclear Information System (INIS)

    Kurihara, Kunitoshi; Azekura, Kazuo.

    1992-01-01

    In a reactor core of a heavy water moderated light water cooled pressure tube type reactor, no sufficient effects have been obtained for the transfer width to a negative side of void reactivity change in a region of a great void coefficient. Then, a moderation region divided into upper and lower two regions is disposed at the central portion of a fuel assembly. Coolants flown into the lower region can be discharged to the cooling region from an opening disposed at the upper end portion of the lower region. Light water flows from the lower region of the moderator region to the cooling region of the reactor core upper portion, to lower the void coefficient. As a result, the reactivity performance at low void coefficient, i.e., a void reaction rate is transferred to the negative side. Thus, this flattens the power distribution in the fuel assembly, increases the thermal margin and enables rapid operaiton and control of the reactor core, as well as contributes to the increase of fuel burnup ratio and reduction of the fuel cycle cost. (N.H.)

  8. Fuel assembly

    International Nuclear Information System (INIS)

    Fushimi, Atsushi; Shimada, Hidemitsu; Aoyama, Motoo; Nakajima, Junjiro

    1998-01-01

    In a fuel assembly for an n x n lattice-like BWR type reactor, n is determined to 9 or greater, and the enrichment degree of plutonium is determined to 4.4% by weight or less. Alternatively, n is determined to 10 or greater, and the enrichment degree of plutonium is determined to 5.2% by weight or less. An average take-out burnup degree is determined to 39GWd/t or less, and the matrix is determined to 9 x 9 or more, or the average take-out burnup degree is determined to 51GWd/t, and the matrix is determined to 10 x 10 or more and the increase of the margin of the maximum power density obtained thereby is utilized for the compensation of the increase of distortion of power distribution due to decrease of the kinds of plutonium enrichment degree, thereby enabling to reduce the kind of the enrichment degree of MOX fuel rods to one. As a result, the manufacturing step for fuel pellets can be simplified to reduce the manufacturing cost for MOX fuel assemblies. (N.H.)

  9. Fuel rods

    International Nuclear Information System (INIS)

    Fukushima, Kimichika.

    1984-01-01

    Purpose: To reduce the size of the reactor core upper mechanisms and the reactor container, as well as decrease the nuclear power plant construction costs in reactors using liquid metals as the coolants. Constitution: Isotope capturing devices comprising a plurality of pipes are disposed to the gas plenum portion of a nuclear fuel rod main body at the most downstream end in the flowing direction of the coolants. Each of the capturing devices is made of nickel, nickel alloys, stainless steel applied with nickel plating on the surface, nickel alloys applied with nickel plating on the surface or the like. Thus, radioactive nuclides incorporated in the coolants are surely captured by the capturing devices disposed at the most downstream end of the nuclear fuel main body as the coolants flow along the nuclear fuel main body. Accordingly, since discharging of radioactive nuclides to the intermediate fuel exchange system can be prevented, the maintenance or reparing work for the system can be facilitated. (Moriyama, K.)

  10. Transport fuel

    DEFF Research Database (Denmark)

    Ronsse, Frederik; Jørgensen, Henning; Schüßler, Ingmar

    2014-01-01

    Worldwide, the use of transport fuel derived from biomass increased four-fold between 2003 and 2012. Mainly based on food resources, these conventional biofuels did not achieve the expected emission savings and contributed to higher prices for food commod - ities, especially maize and oilseeds...

  11. All About ALS

    Science.gov (United States)

    ... Subscribe August 2015 Print this issue All About ALS Understanding a Devastating Disorder En español Send us ... Sports Concussions Wise Choices How Can I Help ALS Research? If you have ALS, join the National ...

  12. BISON Fuel Performance Analysis of IFA-796 Rod 3 & 4 and Investigation of the Impact of Fuel Creep

    Energy Technology Data Exchange (ETDEWEB)

    Wirth, Brian [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Terrani, Kurt A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Sweet, Ryan T. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-08-01

    In order to improve the accident tolerance of light water reactor (LWR) fuel, alternative cladding materials have been proposed to replace the currently used zirconium (Zr)-based alloys. Of these materials, there is a particular focus on iron-chromiumaluminum (FeCrAl) alloys because they exhibit slower oxidation kinetics in high-temperature steam than Zr-alloys. This should decrease the energy release due to oxidation and slow cladding consumption in the presence of high temperature steam. These alloys should also exhibit increased “coping time” in the event of an accident scenario by improving the mechanical performance at high temperatures, allowing greater flexibility to achieve core cooling. As a continuation of the development of these alloys, in-reactor irradiation testing of FeCrAl cladded fuel rods has started. In order to provide insight on the possible behavior of these fuel rods as they undergo irradiation in the Halden Boiling Water Reactor, engineering analysis has been performed using FeCrAl material models implemented into the BISON fuel performance code. This milestone report provides an update on the ongoing development of modeling capability to predict FeCrAl cladding fuel performance and to provide an early look at the possible behavior of planned in-reactor FeCrAl cladding experiments. In particular, this report consists of two separate analyses. The first analysis consists of fuel performance simulations of IFA-796 rod 4 and two segments of rod 3. These simulations utilize previously implemented material models for the C35M FeCrAl alloy and UO2 to provide a bounding behavior analysis corresponding to variation of the initial fuel cladding gap thickness within the fuel rod. The second analysis is an assessment of the fuel and cladding stress states after modification of the fuel creep model that is currently implemented in the BISON fuel performance code. Effects from modifying the fuel creep model were identified for the BISON simulations

  13. Alternative fuels in domestic heating markets. Experimental testing of n-butanol as component in domestic heating oil; Alternative fluessige Energietraeger im Raumwaermemarkt. Experimentelle Ueberpruefung von n-Butanol als Beimischung zu Heizoel EL

    Energy Technology Data Exchange (ETDEWEB)

    Hoffmann, H.; Dohn, N.; Rheinberg, O. van [RWTH Aachen (Germany). OWI Oel-Waerme-Inst. GmbH

    2012-02-15

    N-butanol has already been tested successfully as partial substitute for diesel fuel. However, to date there are no corresponding studies available regarding the use of n-butanol as bio-component in domestic heating oil. Thus, physical and chemical norm parameters of n-butanol/heating oil blends and their combustion specific characteristics in steady operation were examined. The combustion of blends of domestic heating oil and butanol (up to 20 % (v/v)) in a common yellow burner did not indicate negative influence and did not yield a significant change in emissions of carbon monoxide, nitrogen oxides or soot. All tests were conducted without any modifications of the burner to the use of n-butanol. The flash point drops below the limit of 55 C with 1 % (v/v) butanol already and is therefore a flammable liquid. Its use as a substitute for heating oil is therefore limited by safety regulations. Practical applications of n-butanol as bio-component could be its utilization in low concentrations or in facilities providing suitable storage capabilities. (orig.)

  14. Thorium fuel cycle management

    International Nuclear Information System (INIS)

    Zajac, R.; Darilek, P.; Breza, J.; Necas, V.

    2010-01-01

    In this presentation author deals with the thorium fuel cycle management. Description of the thorium fuels and thorium fuel cycle benefits and challenges as well as thorium fuel calculations performed by the computer code HELIOS are presented.

  15. Sinterability and conductivity of barium doped aluminium lanthanum oxyapatite La{sub 9.5}Ba{sub 0.5}Si{sub 5.5}Al{sub 0.5}O{sub 26.5} electrolyte of solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Cao Xiaoguo [Faculty of Materials and Energy, Guangdong University of Technology, Guangzhou 510006, Guangdong (China); Jiang Sanping, E-mail: s.jiang@curtin.edu.au [Fuels and Energy Technology Institute and Department of Chemical Engineering, Curtin University, Perth, WA 6102 (Australia)

    2012-05-15

    Highlights: Black-Right-Pointing-Pointer Ba doping enhances the sintering and densification properties of aluminium lanthanum apatite. Black-Right-Pointing-Pointer Ba doping improves the oxide conductivity of aluminium lanthanum apatite. Black-Right-Pointing-Pointer The enhancement of Ba doping is mainly due to the significantly reduced grain boundary resistance of the aluminium lanthanum apatite. - Abstract: Apatite ceramics are interesting alternative solid oxide fuel cells (SOFCs) electrolytes because of their open structure for the transportation of oxide ions and their good chemical stability. This study reports the influence of barium doping on the microstructure, sinterability and oxide conductivity properties of the aluminium lanthanum oxyapatite La{sub 9.5}Ba{sub 0.5}Si{sub 5.5}Al{sub 0.5}O{sub 26.5}. SEM results show that lanthanum substitution with barium improves the sinterability of apatite ceramics. The barium doping also enhances the conductivity of the aluminium lanthanum silicates. The oxygen ion conductivity of La{sub 9.5}Ba{sub 0.5}Si{sub 5.5}Al{sub 0.5}O{sub 26.5} sintered at 1600 Degree-Sign C is 2.21 Multiplication-Sign 10{sup -2} S cm{sup -1} at 800 Degree-Sign C, higher than 9.81 Multiplication-Sign 10{sup -3} S cm{sup -1} of La{sub 10}Si{sub 5}AlO{sub 26.5} sample prepared under the same conditions. The results in the present study demonstrate that doping Ba on the La site for aluminium lanthanum oxyapatite reduces the sintering temperature and improves the ion conductivity. The enhancement of Ba dopant is mainly on the improvement of the densification and thus substantially reduced grain boundary resistance of aluminium lanthanum oxyapatite particularly at low temperatures.

  16. Repairing fuel for reinsertion

    International Nuclear Information System (INIS)

    Krukshenk, A.

    1986-01-01

    Eqiupment for nuclear reactor fuel assembly repairing produced by Westinghouse and Brawn Bovery companies is described. Repair of failed fuel assemblies replacement of defect fuel elements gives a noticeable economical effect. Thus if the cost of a new fuel assembly is 450-500 thousand dollars, the replacement of one fuel element in it costs approximately 40-60 thousand dollars. In simple cases repairing includes either removal of failed fuel elements from a fuel assembly and its reinsertion with the rest of fuel elements into the reactor core (reactor refueling), or replacement of unfailed fuel elements from one fuel assembly to a new one (fuel assembly overhaul and reconditioning)

  17. U-Mo/Al-Si interaction: Influence of Si concentration

    International Nuclear Information System (INIS)

    Allenou, J.; Palancher, H.; Iltis, X.; Cornen, M.; Tougait, O.; Tucoulou, R.; Welcomme, E.; Martin, Ph.; Valot, C.; Charollais, F.; Anselmet, M.C.; Lemoine, P.

    2010-01-01

    Within the framework of the development of low enriched nuclear fuels for research reactors, U-Mo/Al is the most promising option that has however to be optimised. Indeed at the U-Mo/Al interfaces between U-Mo particles and the Al matrix, an interaction layer grows under irradiation inducing an unacceptable fuel swelling. Adding silicon in limited content into the Al matrix has clearly improved the in-pile fuel behaviour. This breakthrough is attributed to an U-Mo/Al-Si protective layer around U-Mo particles appeared during fuel manufacturing. In this work, the evolution of the microstructure and composition of this protective layer with increasing Si concentrations in the Al matrix has been investigated. Conclusions are based on the characterization at the micrometer scale (X-ray diffraction and energy dispersive spectroscopy) of U-Mo7/Al-Si diffusion couples obtained by thermal annealing at 450 deg. C. Two types of interaction layers have been evidenced depending on the Si content in the Al-Si alloy: the threshold value is found at about 5 wt.% but obviously evolves with temperature. It has been shown that for Si concentrations ranging from 2 to 10 wt.%, the U-Mo7/Al-Si interaction is bi-layered and the Si-rich part is located close to the Al-Si for low Si concentrations (below 5 wt.%) and close to the U-Mo for higher Si concentrations. For Si weight fraction in the Al alloy lower than 5 wt.%, the Si-rich sub-layer (close to Al-Si) consists of U(Al, Si) 3 + UMo 2 Al 20 , when the other sub-layer (close to U-Mo) is silicon free and made of UAl 3 and U 6 Mo 4 Al 43 . For Si weight concentrations above 5 wt.%, the Si-rich part becomes U 3 (Si, Al) 5 + U(Al, Si) 3 (close to U-Mo) and the other sub-layer (close to Al-Si) consists of U(Al, Si) 3 + UMo 2 Al 20 . On the basis of these results and of a literature survey, a scheme is proposed to explain the formation of different types of ILs between U-Mo and Al-Si alloys (i.e. different protective layers).

  18. Nuclear power fuel cycle

    International Nuclear Information System (INIS)

    Havelka, S.; Jakesova, L.

    1982-01-01

    Economic problems are discussed of the fuel cycle (cost of the individual parts of the fuel cycle and the share of the fuel cycle in the price of 1 kWh), the technological problems of the fuel cycle (uranium ore mining and processing, uranium isotope enrichment, the manufacture of fuel elements, the building of long-term storage sites for spent fuel, spent fuel reprocessing, liquid and gaseous waste processing), and the ecologic aspects of the fuel cycle. (H.S.)

  19. Status of high-density fuel plate fabrication

    International Nuclear Information System (INIS)

    Wiencek, T.C.; Domagala, R.F.; Thresh, H.R.

    1991-01-01

    Progress has continued on the fabrication of fuel plates with equivalent fuel zone loadings approaching 9 gU/cm 3 . Through hot isostatic pressing (HIP), successful diffusion bonds have been made with 1100 Al and 6061 Al alloys. Although additional study is necessary to optimize the procedure, these bonds demonstrated the most critical processing step for proof-of-concept hardware. Two types of prototype highly loaded fuel plates have been fabricated. The first is a fuel plate in which 0.030-in. (0.76-mm) uranium compound wires are bonded within an aluminum cladding; the second, a dispersion fuel plate with uniform cladding and fuel zone thickness. The successful fabrication of these fuel plates derives from the unique ability of the HIP process to produce diffusion bonds with minimal deformation. (orig.)

  20. Fuels for research and test reactors, status review: July 1982

    International Nuclear Information System (INIS)

    Stahl, D.

    1982-12-01

    A thorough review is provided on nuclear fuels for steady-state thermal research and test reactors. The review was conducted to provide a documented data base in support of recent advances in research and test reactor fuel development, manufacture, and demonstration in response to current US policy on availability of enriched uranium. The review covers current fabrication practice, fabrication development efforts, irradiation performance, and properties affecting fuel utilization, including thermal conductivity, specific heat, density, thermal expansion, corrosion, phase stability, mechanical properties, and fission-product release. The emphasis is on US activities, but major work in Europe and elsewhere is included. The standard fuel types discussed are the U-Al alloy, UZrH/sub x/, and UO 2 rod fuels. Among new fuels, those given major emphasis include H 3 Si-Al dispersion and UO 2 caramel plate fuels

  1. La perspectiva histórico-cultural y la educación especial: contribuciones iniciales y desarrollos actuales ( HISTORICAL – CULTURAL PERSPECTIVE AND THE SPECIAL EDUCATION: EARLY CONTRIBUTIONS AND CURRENT DEVELOPMENTS

    Directory of Open Access Journals (Sweden)

    Mitjáns Martínez Albertina

    2009-11-01

    Full Text Available Resumen:El objetivo principal del artículo es destacar la significación de la perspectiva histórico-cultural del desarrollo humano para el diseño de estrategias educativas favorecedoras del aprendizaje escolar de niños y niñas con deficiencias. A partir de las contribuciones de Vygotsky, en ese campo, y de los aportes de la Teoría de la Subjetividad, elaborada a partir da la perspectiva histórico-cultural, se presentan principios que, en su configuración sistémica, pueden constituir una base sólida para la reestructuración de diversos aspectos del trabajo educativo en la Educación Especial. En la primera parte del artículo son discutidas algunas de las concepciones y conceptos desarrollados por Vygotsky en su obra “Fundamentos de Defectología”. La fundamentación del carácter social de la deficiencia, los conceptos de defecto primario, defecto secundario y compensación, y la consideración del carácter creativo del aprendizaje y del desarrollo de las niñas y los niños deficientes. Se presentan las ideas centrales de la Teoría de la Subjetividad elaborada por González Rey, especialmente la concepción del aprendizaje escolar como un proceso de la subjetividad irreducible a habilidades y procesos intelectuales. Por último, se fundamentan tres implicaciones educacionales derivadas de la articulación de los dos sistemas conceptuales presentados: favorecer la creación de espacios comunicativos/relacionales que contribuyan a generar en el niño nuevas producciones de sentido sobre el aprendizaje y sobre la deficiencia, estimular en ellos el desarrollo de la condición de sujetos negada por las posiciones asistencialistas y paternalistas dominantes y el enfoque cualitativo, constructivo, singular, procesual e interactivo de los procesos de diagnóstico y de evaluación educacional.Abstract:The main proposal of this paper is to discuss the significance of historical–cultural approach in human development for the designing

  2. Community contributions to a FHU team work Las contribuciones de la comunidad para el trabajo del equipo de un PSF As contribuições da comunidade para o trabalho da equipe de um PSF

    Directory of Open Access Journals (Sweden)

    Maria José Sanches Marin

    2007-12-01

    Full Text Available Considering the importance of people participating in the construction of new health models, this study aimed to characterize and analyze contributions brought by community to health actions carried out in a Family Health Unit. It is a documentary analysis based on the records of 24 monthly meetings between the team and community. After reading the records, subject was divided into four themes: material and human resources, availability to secondary level health services, community adherence to the unit activities, health promotion and disease prevention. Discussions opened a wide perspective on health and stimulated co-responsibility, stronger links and information exchanging. Nevertheless, there is a need to improve community effective participation in the co-management of the health system.Considerando la relevancia de la participación de la población en la construcción de nuevos modelos de salud, el presente estudio propone caracterizar y analizar las contribuciones de la participación de la comunidad en las acciones de salud de una Unidad de Salud de la Familia. Se trata de un estudio de análisis documentario, basado en actas de 24 reuniones mensuales del equipo con la comunidad. Después de la lectura de los registros, los asuntos fueran clasificados en cuatro temáticas: recursos materiales y humanos, accesos a los servicios de salud de nivel secundario, adherencia de la comunidad a las actividades ofrecidas por la unidad y promoción de la salud y prevención de enfermedades. Verificó-se que las discusiones destacaron una visión íntegra de la salud e hicieron posible la co-responsabilidad, fortalecimiento del vínculo y cambio de información. Todavía es necesario avanzar para obtener la efectiva participación de la comunidad en la co-gestión del sistema de salud.Considerando a relevância da participação popular na construção de novos modelos de saúde, o presente estudo propõe-se a verificar as contribuições dessa

  3. Interdiffusion between U-Mo alloys and Al

    International Nuclear Information System (INIS)

    Mirandou, M.I.; Balart, S.N.; Ortiz, M.; Granovsky, M.S.; Hofman, G.L.

    2002-01-01

    During the fabrication and/or irradiation of the dispersion fuel elements, the fuel particles react with the surrounding Al matrix. This reaction results in the formation of a zone consisting of intermetallic compounds. The low thermal conductivity of these compounds has a major effect on the fuel temperature as well as on the swelling of the fuel. Interdiffusion between U-Mo/Al is being investigated using chemical diffusion couples. In this paper the first results obtained with optical and scanning electron microscope, electron microprobe and X-Ray diffraction are presented. Investigation of the effect on the formation of the interdiffusion zone of small additions of Mg to Al is the primary purpose of this study. (author)

  4. Growth of the interaction layer around fuel particles in dispersion fuel

    International Nuclear Information System (INIS)

    Olander, D.

    2009-01-01

    Corrosion of uranium particles in dispersion fuel by the aluminum matrix produces interaction layers (an intermetallic-compound corrosion product) around the shrinking fuel spheres. The rate of this process was modeled as series resistances due to Al diffusion through the interaction layer and reaction of aluminum with uranium in the fuel particle to produce UAl x . The overall kinetics are governed by the relative rates of these two steps, the slowest of which is reaction at the interface between Al in the interaction layer and U in the fuel particle. The substantial volume change as uranium is transferred from the fuel to the interaction layer was accounted for. The model was compared to literature data on in-reactor growth of the interaction layer and the Al/U gradient in this layer, the latter measured in ex-reactor experiments. The rate constant of the Al-U interface reaction and the diffusivity of Al in the interaction layer were obtained from this fitting procedure. The second feature of the corrosion process is the transfer of fission products from the fuel particle to the interaction layer due to the reaction. It is commonly assumed that the observed swelling of irradiated fuel elements of this type is due to release of fission gas in the interaction layer to form large bubbles. This hypothesis was tested by using the model to compute the quantity of fission gas available from this source and comparing the pressure of the resulting gas with the observed swelling of fuel plates. It was determined that the gas pressure so generated is too small to account for the observed delamination of the fuel

  5. Alcohol fuels program technical review

    Energy Technology Data Exchange (ETDEWEB)

    None

    1981-07-01

    The last issue of the Alcohol Fuels Process R/D Newsletter contained a work breakdown structure (WBS) of the SERI Alcohol Fuels Program that stressed the subcontracted portion of the program and discussed the SERI biotechnology in-house program. This issue shows the WBS for the in-house programs and contains highlights for the remaining in-house tasks, that is, methanol production research, alcohol utilization research, and membrane research. The methanol production research activity consists of two elements: development of a pressurized oxygen gasifier and synthesis of catalytic materials to more efficiently convert synthesis gas to methanol and higher alcohols. A report is included (Finegold et al. 1981) that details the experimental apparatus and recent results obtained from the gasifier. The catalysis research is principally directed toward producing novel organometallic compounds for use as a homogeneous catalyst. The utilization research is directed toward the development of novel engine systems that use pure alcohol for fuel. Reforming methanol and ethanol catalytically to produce H/sub 2/ and CO gas for use as a fuel offers performance and efficiency advantages over burning alcohol directly as fuel in an engine. An application of this approach is also detailed at the end of this section. Another area of utilization is the use of fuel cells in transportation. In-house researchers investigating alternate electrolyte systems are exploring the direct and indirect use of alcohols in fuel cells. A workshop is being organized to explore potential applications of fuel cells in the transportation sector. The membrane research group is equipping to evaluate alcohol/water separation membranes and is also establishing cost estimation and energy utilization figures for use in alcohol plant design.

  6. Fuel trading

    International Nuclear Information System (INIS)

    2015-01-01

    A first part of this report proposes an overview of trends and predictions. After a synthesis on the sector changes and trends, it indicates and comments the most recent predictions for the consumption of refined oil products and for the turnover of the fuel wholesale market, reports the main highlights concerning the sector's life, and gives a dashboard of the sector activity. The second part proposes the annual report on trends and competition. It presents the main operator profiles and fuel categories, the main determining factors of the activity, the evolution of the sector context between 2005 and 2015 (consumptions, prices, temperature evolution). It analyses the evolution of the sector activity and indicators (sales, turnovers, prices, imports). Financial performances of enterprises are presented. The economic structure of the sector is described (evolution of the economic fabric, structural characteristics, French foreign trade). Actors are then presented and ranked in terms of turnover, of added value, and of result

  7. Fuel assembly

    International Nuclear Information System (INIS)

    Ueda, Makoto.

    1991-01-01

    In a fuel assembly in which spectral shift type moderator guide members are arranged, the moderator guide member has a flow channel resistance member, that provides flow resistance against the moderators, in the upstream of a moderator flowing channel, by which the ratio of removing coolants is set greater at the upstream than downstream. With such a constitution, the void distribution increasing upward in the channel box except for the portion of the moderator guide member is moderated by the increase of the area of the void region that expands downward in the guide member. Accordingly, the axial power distribution is flattened throughout the operation cycle and excess distortion is eliminated to improve the fuel integrity. (T.M.)

  8. Fuel element

    International Nuclear Information System (INIS)

    Hirose, Yasuo.

    1982-01-01

    Purpose: To increase the plenum space in a fuel element used for a liquid metal cooled reactor. Constitution: A fuel pellet is secured at one end with an end plug and at the other with a coil spring in a tubular container. A mechanism for fixing the coil spring composed of a tubular unit is mounted by friction with the inner surface of the tubular container. Accordingly, the recoiling force of the coil spring can be retained by fixing mechanism with a small volume, and since a large amount of plenum space can be obtained, the internal pressure rise in the cladding tube can be suppressed even if large quantities of fission products are discharged. (Kamimura, M.)

  9. Fuel assembly

    International Nuclear Information System (INIS)

    Kawai, Mitsuo.

    1988-01-01

    Purpose: To reduce the corrosion rate and suppress the increase of radioactive corrosion products in reactor water of nuclear fuel assemblies for use in BWR type reactors having spacer springs made of nickel based deposition reinforced type alloys. Constitution: Spacer rings made of nickel based deposition reinforced type alloy are incorporated and used as fuel assemblies after applying treatment of dipping and maintaining at high temperature water followed by heating in steams. Since this can remove the nickel leaching into reactor water at the initial stage, Co-58 as the radioactive corrosion products in the reactor water can be reduced, and the operation at in-service inspection or repairement can be facilitated to improve the working efficiency of the nuclear power plant. The dipping time is desirably more than 10 hours and more desirably more than 30 hours. (Horiuchi, T. )

  10. Fuel assemblies

    International Nuclear Information System (INIS)

    Yoshioka, Ritsuo.

    1983-01-01

    Purpose: To improve the operation performance of a BWR type reactor by improving the distribution of the uranium enrichment and the incorporation amount of burnable poisons in fuel assemblies. Constitution: The average enrichment of uranium 235 is increased in the upper portion as compared with that in the lower portion, while the incorporation amount of burnable poisons is increased in an upper portion as compared with that in the lower portion. The difference in the incorporation amount of the burnable poisons between the upper and lower portions is attained by charging two kinds of fuel rods; the ones incorporated with the burnable poisons over the entire length and the others incorporated with the burnable poisons only in the upper portions. (Seki, T.)

  11. Predicting Argentine Jet Fuel Prices

    Science.gov (United States)

    2007-03-01

    economics, engineering, and the social and biological sciences (Kutner, 2005:2), but successful application of this method requires not only a deep...situations that affected the country. This crisis had politic, economic and social implications. Five presidents governed in a two month period. The...Scheimberg Sebastian. “Comentario al trabajo de German Coloma: Analisys of the behavior of the Argentine fuel market”. Political Economy Asociation

  12. Fuel assembly

    International Nuclear Information System (INIS)

    Hirukawa, Koji; Sakurada, Koichi.

    1992-01-01

    In a fuel assembly for a BWR type reactor, water rods or water crosses are disposed between fuel rods, and a value with a spring is disposed at the top of the coolant flow channel thereof, which opens a discharge port when pressure is increased to greater than a predetermined value. Further, a control element for the amount of coolant flow rate is inserted retractable to a control element guide tube formed at the lower portion of the water rod or the water cross. When the amount of control elements inserted to the control element guide tube is small and the inflown coolant flow rate is great, the void coefficient at the inside of the water rod is less than 5%. On the other hand, when the control elements are inserted, the flow resistance is increased, so that the void coefficient in the water rod is greater than 80%. When the pressure in the water rod is increased, the valve with the spring is raised to escape water or steams. Then, since the variation range of the change of the void coefficient can be controlled reliably by the amount of the control elements inserted, and nuclear fuel materials can be utilized effectively. (N.H.)

  13. SOBRE CORPORALIDADE E ESCOLARIZAÇÃO: CONTRIBUIÇÕES PARA A REORIENTAÇÃO DAS PRÁTICAS ESCOLARES DA DISCIPLINA DE EDUCAÇÃO FÍSICA ON CORPORALITY AND SCHOOLING: CONTRIBUTIONS FOR A REORIENTATION OF SCHOOL PRACTICES IN PHYSICAL EDUCATION SOBRE CORPORALIDAD Y ESCOLARIZACIÓN:CONTRIBUCIONES PARA LA REORIENTACIÓN DE LAS PRACTICAS ESCOLARES DE LA DISCIPLINA EDUCACIÓN FÍSICA

    Directory of Open Access Journals (Sweden)

    2008-12-01

    understanding of the corporal practices that considers elements beyond the corporal movement. Este artículo reúne contribuciones al debate sobre la constitución de directrices curriculares para lo enseño de Educación Física en la provincia de Paraná, Brasil. Después de presentado el contexto en lo cual se generó el texto – que resultó también de debates con profesores escolares de la provincia – si discute una concepción para la disciplina Educación Física en la escuela, espacio pedagógico en lo cual el cuerpo es protagonista. Se presenta entonces una serie de conceptos y argumentos en favor de la corporalidad con centro articulador de las clases de Educación Física que, por su vez, pueden ser organizadas en cuatro ejes: el cuerpo que brinca y aprende, potencial expresivo del cuerpo, desarrollo corporal y construcción de la salud, relación del cuerpo con el mundo del trabajo. Se argumenta, en correspondencia con el concepto de corporalidad presentado, por una comprensión más ancha de las practicas corporales que considere elementos mas allá del movimiento corporal.

  14. O modelo bioecológico: desvendando contribuições para a práxis da enfermagem diante da violência doméstica El modelo bioecológico: contribuciones a la divulgación de la praxis de enfermería relacionados con la violencia doméstica Bioecological model: unveiling contributions to the nursing practice within domestic violence

    Directory of Open Access Journals (Sweden)

    Janete Maria da Silva Batista

    2013-03-01

    Full Text Available Trata-se de um artigo de reflexão que teve o objetivo de discutir sobre os elementos do Modelo Bioecológico do Desenvolvimento Humano de Bronfenbrenner com a expectativa de encontrar contribuições para o conhecimento de enfermagem e sua práxis na interface com a violência doméstica. Compreender a complexidade do ser humano na perspectiva bioecológica possibilita o desenvolvimento de uma práxis transformadora no contexto da atuação da enfermeira diante da demanda de cuidados à pessoa que vivencia este tipo de violência. Considera-se que esta teoria sobre o desenvolvimento humano traz em sua estrutura elementos constituintes das inter-relações da pessoa e o ambiente ao seu entorno, como fatores determinantes na formação do indivíduo. Assim, ao se apropriar deste modelo, a enfermagem amplia o seu olhar sobre a multidimensionalidade humana, o que pode refletir no cuidado perante as situações de violência doméstica.Este es un artículo de reflexión que tuvo el propósito de discutir los elementos del modelo Bioecológico de Desarrollo Humano Bronfenbrenner, esperando encontrar las contribuciones al conocimiento y práctica de enfermería en su interface con la violencia doméstica. Comprender la complejidad de los seres humanos en la perspectiva bioecológica permite el desarrollo de una praxis transformadora en el marco de las acciones del enfermo frente a la demanda de atención a la persona que experimenta este tipo de violencia. Se considera que esta teoría sobre el desarrollo humano trae en su estructura elementos de relaciones interpersonales y el ambiente con su entorno, tales como factores determinantes en la formación del individuo. Así, la enfermería al apropiarse de este modelo amplía su mirada en el ser humano multidimensional, que puede reflexionar sobre su práctica frente a las situaciones de violencia doméstica.It is a reflection paper which objectified to discuss the elements of Bronfenbrenner

  15. Solid TRU fuels and fuel cycle technology

    International Nuclear Information System (INIS)

    Ogawa, Toru; Suzuki, Yasufumi

    1997-01-01

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

  16. Fuel Performance Modeling of U-Mo Dispersion Fuel: The thermal conductivity of the interaction layers of the irradiated U-Mo dispersion fuel

    Energy Technology Data Exchange (ETDEWEB)

    Mistarhi, Qusai M.; Ryu, Ho Jin [KAIST, Daejeon (Korea, Republic of)

    2016-05-15

    U-Mo/Al dispersion fuel performed well at a low burn-up. However, higher burn-up and higher fission rate irradiation testing showed enhanced fuel meat swelling which was caused by high interaction layer growth and pore formation. The performance of the dispersion type fuel in the irradiation and un-irradiation environment is very important. During the fabrication of the dispersion type fuel an Interaction Layer (IL) is formed due to the inter-diffusion between the U-Mo fuel particles and the Al matrix which is an intermetallic compound (U,Mo)Alx. During irradiation, the IL becomes amorphous causing a further decrease in the thermal conductivity and an increase in the centerline temperature of the fuel meat. Several analytical models and numerical methods were developed to study the performance of the unirradiated U-Mo/Al dispersion fuel. Two analytical models were developed to study the performance of the irradiated U-Mo/Al dispersion fuel. In these models, the thermal conductivity of the IL was assumed to be constant. The properties of the irradiated U-Mo dispersion fuel have been investigated recently by Huber et al. The objective of this study is to develop a correlation for IL thermal conductivity during irradiation as a function of the temperature and fission density from the experimentally measured thermal conductivity of the irradiated U-Mo/Al dispersion fuel. The thermal conductivity of IL during irradiation was calculated from the experimentally measured data and a correlation was developed from the thermal conductivity of IL as a function of T and fission density.

  17. Used fuel packing plant for CANDU fuel

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-07-01

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

  18. Nuclear fuel preheating system

    International Nuclear Information System (INIS)

    Andrea, C.

    1975-01-01

    A nuclear reactor new fuel handling system which conveys new fuel from a fuel preparation room into the reactor containment boundary is described. The handling system is provided with a fuel preheating station which is adaptd to heat the new fuel to reactor refueling temperatures in such a way that the fuel is heated from the top down so that fuel element cladding failure due to thermal expansions is avoided. (U.S.)

  19. Fuel element loading system

    International Nuclear Information System (INIS)

    Arya, S.P; s.

    1978-01-01

    A nuclear fuel element loading system is described which conveys a plurality of fuel rods to longitudinal passages in fuel elements. Conveyor means successively position the fuel rods above the longitudinal passages in axial alignment therewith and adapter means guide the fuel rods from the conveyor means into the longitudinal passages. The fuel elements are vibrated to cause the fuel rods to fall into the longitudinal passages through the adapter means

  20. Artificial fuel

    Energy Technology Data Exchange (ETDEWEB)

    Hamon, L L.W.

    1918-08-20

    Lignite, peat, sud, leaf-mold, or shale, or two or more of these raw carbonaceous materials are mixed with cellulose material, such as sawdust, silica, alkali, and tar or pitch, or residues from tar or pitch, or residues from the distillation of oils, and the mixture is molded into blocks. Other carbonaceous materials, such as graphite, anthracite, or coal-dust, coke, breeze, or culm, and mineral substances, such as iron and manganese ores, may be added. A smokeless fuel can be obtained by coking the blocks in the usual way in retorts.

  1. Modeling RERTR experimental fuel plates using the PLATE code

    International Nuclear Information System (INIS)

    Hayes, S.L.; Meyer, M.K.; Hofman, G.L.; Snelgrove, J.L.; Brazener, R.A.

    2003-01-01

    Modeling results using the PLATE dispersion fuel performance code are presented for the U-Mo/Al experimental fuel plates from the RERTR-1, -2, -3 and -5 irradiation tests. Agreement of the calculations with experimental data obtained in post-irradiation examinations of these fuels, where available, is shown to be good. Use of the code to perform a series of parametric evaluations highlights the sensitivity of U-Mo dispersion fuel performance to fabrication variables, especially fuel particle shape and size distributions. (author)

  2. Irradiation experience of IPEN fuel at IEA-R1 research reactor

    International Nuclear Information System (INIS)

    Perrotta, Jose A.; Neto, Adolfo; Durazzo, Michelangelo; Souza, Jose A.B. de; Frajndlich, Roberto

    1998-01-01

    IPEN/CNEN-SP produces, for its IEA-R1 Research Reactor, MTR fuel assemblies based on U 3 O 8 -Al dispersion fuel type. Since 1985 a qualification program on these fuel assemblies has been performed. Average 235 U burnup of 30% and peak burnup of 50% was already achieved by these fuel assemblies. This paper presents some results acquire, by these fuel assemblies, under irradiation at IEA-R1 Research Reactor. (author)

  3. Irradiation performance of U-Mo monolithic fuel

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, M. K.; Gan, J.; Jue, J. F.; Keiser, D. D.; Perez, E.; Robinson, A.; Wachs, D. M.; Woolstenhulme, N. [Idaho National Laboratory, Idaho (Korea, Republic of); Kim, Y.S.; Hofman, G. L. [Argonne National Laboratory, Lemont (United States)

    2014-04-15

    High-performance research reactors require fuel that operates at high specific power to high fission density, but at relatively low temperatures. Research reactor fuels are designed for efficient heat rejection, and are composed of assemblies of thin-plates clad in aluminum alloy. The development of low-enriched fuels to replace high-enriched fuels for these reactors requires a substantially increased uranium density in the fuel to offset the decrease in enrichment. Very few fuel phases have been identified that have the required combination of very-high uranium density and stable fuel behavior at high burnup. U-Mo alloys represent the best known tradeoff in these properties. Testing of aluminum matrix U-Mo aluminum matrix dispersion fuel revealed a pattern of breakaway swelling behavior at intermediate burnup, related to the formation of a molybdenum stabilized high aluminum intermetallic phase that forms during irradiation. In the case of monolithic fuel, this issue was addressed by eliminating, as much as possible, the interfacial area between U-Mo and aluminum. Based on scoping irradiation test data, a fuel plate system composed of solid U-10Mo fuel meat, a zirconium diffusion barrier, and Al6061 cladding was selected for development. Developmental testing of this fuel system indicates that it meets core criteria for fuel qualification, including stable and predictable swelling behavior, mechanical integrity to high burnup, and geometric stability. In addition, the fuel exhibits robust behavior during power-cooling mismatch events under irradiation at high power.

  4. IRRADIATION PERFORMANCE OF U-Mo MONOLITHIC FUEL

    Directory of Open Access Journals (Sweden)

    M.K. MEYER

    2014-04-01

    Full Text Available High-performance research reactors require fuel that operates at high specific power to high fission density, but at relatively low temperatures. Research reactor fuels are designed for efficient heat rejection, and are composed of assemblies of thin-plates clad in aluminum alloy. The development of low-enriched fuels to replace high-enriched fuels for these reactors requires a substantially increased uranium density in the fuel to offset the decrease in enrichment. Very few fuel phases have been identified that have the required combination of very-high uranium density and stable fuel behavior at high burnup. UMo alloys represent the best known tradeoff in these properties. Testing of aluminum matrix U-Mo aluminum matrix dispersion fuel revealed a pattern of breakaway swelling behavior at intermediate burnup, related to the formation of a molybdenum stabilized high aluminum intermetallic phase that forms during irradiation. In the case of monolithic fuel, this issue was addressed by eliminating, as much as possible, the interfacial area between U-Mo and aluminum. Based on scoping irradiation test data, a fuel plate system composed of solid U-10Mo fuel meat, a zirconium diffusion barrier, and Al6061 cladding was selected for development. Developmental testing of this fuel system indicates that it meets core criteria for fuel qualification, including stable and predictable swelling behavior, mechanical integrity to high burnup, and geometric stability. In addition, the fuel exhibits robust behavior during power-cooling mismatch events under irradiation at high power.

  5. Radionuclide release from research reactor spent fuel

    Energy Technology Data Exchange (ETDEWEB)

    Curtius, H., E-mail: h.curtius@fz-juelich.de [Forschungszentrum Juelich, Institut fuer Energieforschung, IEF-6 Sicherheitsforschung und Reaktortechnik, Geb. 05.3, D-52425 Juelich (Germany); Kaiser, G.; Mueller, E.; Bosbach, D. [Forschungszentrum Juelich, Institut fuer Energieforschung, IEF-6 Sicherheitsforschung und Reaktortechnik, Geb. 05.3, D-52425 Juelich (Germany)

    2011-09-01

    Numerous investigations with respect to LWR fuel under non oxidizing repository relevant conditions were performed. The results obtained indicate slow corrosion rates for the UO{sub 2} fuel matrix. Special fuel-types (mostly dispersed fuels, high enriched in {sup 235}U, cladded with aluminium) are used in German research reactors, whereas in German nuclear power plants, UO{sub 2}-fuel (LWR fuel, enrichment in {sup 235}U up to 5%, zircaloy as cladding) is used. Irradiated research reactor fuels contribute less than 1% to the total waste volume. In Germany, the state is responsible for fuel operation and for fuel back-end options. The institute for energy research (IEF-6) at the Research Center Juelich performs investigation with irradiated research reactor spent fuels under repository relevant conditions. In the study, the corrosion of research reactor spent fuel has been investigated in MgCl{sub 2}-rich salt brine and the radionuclide release fractions have been determined. Leaching experiments in brine with two different research reactor fuel-types were performed in a hot cell facility in order to determine the corrosion behaviour and the radionuclide release fractions. The corrosion of two dispersed research reactor fuel-types (UAl{sub x}-Al and U{sub 3}Si{sub 2}-Al) was studied in 400 mL MgCl{sub 2}-rich salt brine in the presence of Fe{sup 2+} under static and initially anoxic conditions. Within these experimental parameters, both fuel types corroded in the experimental time period of 3.5 years completely, and secondary alteration phases were formed. After complete corrosion of the used research reactor fuel samples, the inventories of Cs and Sr were quantitatively detected in solution. Solution concentrations of Am and Eu were lower than the solubility of Am(OH){sub 3}(s) and Eu(OH){sub 3}(s) solid phases respectively, and may be controlled by sorption processes. Pu concentrations may be controlled by Pu(IV) polymer species, but the presence of Pu(V) and Pu

  6. Nuclear Fuel elements

    International Nuclear Information System (INIS)

    Hirakawa, Hiromasa.

    1979-01-01

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

  7. Development of the fabrication technology of the simulated fuel-I, 15,000MWd/tU

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Kweon Ho; Kim, D. J.; Kim, H. S.; Lee, J. W.; Yang, M. S

    2001-04-01

    It is important to get basic data to analysis physical properties, behavior in reactor and performance of the DUPIC fuel because physical properties, fission gas release, grain growth and et al. of the DUPIC fuel is different from the commercial UO2 fuel. But what directly measures physical properties et al. of DUPIC fuel being resinterred simulated spent fuel through OREOX process is very difficult in laboratory owing to its high level radiation. Then fabrication of simulated DUPIC fuel is needed to measure its properties. In this study, the sintering characterization of wet milled powder for 24 hours to fabricate 15,000MWd/tU equivalent burnup simulated fuel.

  8. Pesquisa acadêmica sobre humanização do parto no Brasil: tendências e contribuições Investigaciones académicas sobre Humanización del Parto en Brasil: tendencias y contribuciones Academic research studies on humanization of childbirth in Brazil: trends and contributions

    Directory of Open Access Journals (Sweden)

    Adriana Lenho de Figueiredo Pereira

    2007-06-01

    Full Text Available OBJETIVOS: Realizamos um levantamento das pesquisas acadêmicas brasileiras dos programas de pós-graduação stricto sensu acerca da humanização do parto e nascimento, de forma a identificar a distribuição temporal, regional, por abordagem metodológica e área de conhecimento, e analisar as contribuições desta produção acadêmica para a prática assistencial. MÉTODOS: Pesquisa exploratória e descritiva. Os dados foram coletados através dos resumos de teses e dissertações disponíveis em bases de dados de bibliotecas virtuais, BIREME e CAPES. RESULTADOS: Foram encontradas 26 dissertações e 4 teses no período de 1987 a 2004. A maioria (20; 66,7% foi desenvolvida em programas de pós-graduação da região Sudeste. Mais da metade (16; 53,3% do total foi realizada em programas de pós-graduação de enfermagem. A metodologia qualitativa foi a mais utilizada (25; 80%. Os aspectos ético-políticos da assistência predominaram (20; 66,7% sobre os aspectos técnicos nas sínteses dos resultados e conclusões das pesquisas estudadas. CONCLUSÃO: As pesquisas de pós-graduação propõem mudança de paradigma técnico-científico, na formação profissional, na atitude profissional frente aos direitos humanos e sociais, e uma redefinição de papeis profissionais das enfermeiras e parteiras.OBJETIVOS: Fue realizado un levantamiento de las investigaciones académicas brasileñas de los programas de postgrado stricto sensu respecto a la humanización del parto y nacimiento, de forma a identificar la distribución temporal, regional, por abordaje metodológico y área del conocimiento, y analizar las contribuciones de esta producción académica para la práctica asistencial. MÉTODOS: Se trata de uma investigación exploratória y descriptiva. Los datos fueron recolectados a través de los resúmenes de tesis de maestría y de doctorado disponibles en las bases de datos de bibliotecas virtuales, BIREME y CAPES. RESULTADOS: Fueron

  9. CONTAINMENT EVALUATION OF BREACHED AL-SNF FOR CASK TRANSPORT

    International Nuclear Information System (INIS)

    Vinson, D. W.; Sindelar, R. L.; Iyer, N. C.

    2005-01-01

    Aluminum-based spent nuclear fuel (Al-SNF) from foreign and domestic research reactors (FRR/DRR) is being shipped to the Savannah River Site. To enter the U.S., the cask with loaded fuel must be certified to comply with the requirements in the Title 10 of the U.S. Code of Federal Regulations, Part 71. The requirements include demonstration of containment of the cask with its contents under normal and accident conditions. Al-SNF is subject to corrosion degradation in water storage, and many of the fuel assemblies are ''failed'' or have through-clad damage. A methodology has been developed with technical bases to show that Al-SNF with cladding breaches can be directly transported in standard casks and maintained within the allowable release rates. The approach to evaluate the limiting allowable leakage rate, L R , for a cask with breached Al-SNF for comparison to its test leakage rate could be extended to other nuclear material systems. The approach for containment analysis of Al-SNF follows calculations for commercial spent fuel as provided in NUREG/CR-6487 that adopts ANSI N14.5 as a methodology for containment analysis. The material-specific features and characteristics of damaged Al-SNF (fuel materials, fabrication techniques, microstructure, radionuclide inventory, and vapor corrosion rates) that were derived from literature sources and/or developed in laboratory testing are applied to generate the four containment source terms that yield four separate cask cavity activity densities; namely, those from fines; gaseous fission product species; volatile fission product species; and fuel assembly crud. The activity values, A 2 , are developed per the guidance of 10CFR71. The analysis is performed parametrically to evaluate maximum number of breached assemblies and exposed fuel area for a proposed shipment in a cask with a test leakage rate

  10. Fuel assembly

    International Nuclear Information System (INIS)

    Hiraiwa, Koji; Ueda, Makoto

    1989-01-01

    In a fuel assembly used for a light water cooled reactor such as a BWR type reactor, a water rod is divided axially into an upper outer tube and a lower outer tube by means of a plug disposed from the lower end of a water rod to a position 1/4 - 1/2 of the entire length for the water rod. Inlet apertures and exit apertures for moderators are respectively perforated for the divided outer tube and upper and lower portions. Further, an upper inner tube with less neutron irradiation growing amount than the outer tube is perforated on the plug in the outer tube, while a lower inner tube with greater neutron irradiation growing amount than the outer tube is suspended from the lower surface of the plug in the outer tube. Then, the opening area for the exit apertures disposed to the upper outer tube and the lower outer tube is controlled depending on the difference of the neutron irradiation growing amount between the upper inner tube and the upper outer tube, and the difference of the neutron irradiation growing amount between the lower inner tube and the lower outer tube. This enables effective spectral shift operation and improve the fuel economy. (T.M.)

  11. Fuel Burn Estimation Model

    Science.gov (United States)

    Chatterji, Gano

    2011-01-01

    Conclusions: Validated the fuel estimation procedure using flight test data. A good fuel model can be created if weight and fuel data are available. Error in assumed takeoff weight results in similar amount of error in the fuel estimate. Fuel estimation error bounds can be determined.

  12. /Cu-Al System

    Science.gov (United States)

    Kish, Orel; Froumin, Natalya; Aizenshtein, Michael; Frage, Nachum

    2014-05-01

    Wettability and interfacial interaction of the Ta2O5/Cu-Al system were studied. Pure Cu does not wet the Ta2O5 substrate, and improved spreading is achieved when relatively a high fraction of the active element (~40 at.% Al) was added. The Al2O3 and AlTaO4 phases were observed at the Ta2O5/Cu-Al interface. A thermodynamic evaluation allowed us to suggest that the lack of wetting bellow 40 at.% Al is due to the presence of a native oxide, which covers the drop. The conditions of the native oxide decomposition and the formation of the volatile Al2O suboxide strongly depend on the vacuum level during sessile drop experiments and the composition of the Cu-Al alloy. In our case, Al contents greater than 40% provides thermodynamic conditions for the formation of Al2O (as a result of Al reaction with Al2O3) and the drop spreading. It was suggested that the final contact angle in the Ta2O5/Cu-Al system (50°) is determined by Ta adsorption on the newly formed alumina interlayer.

  13. Fuel assembly storing rack

    International Nuclear Information System (INIS)

    Kajimura, Haruhiko; Nakamura, Masaaki.

    1997-01-01

    In a nuclear fuel storage rack comprising a plurality of square-shaped rack cells arranged vertically in a lattice-like configuration, the square rack cell comprises a stainless steel having a boron content of 0.75% or less and a boron equivalent with respect to calculated thermal neutron absorbing performance of 1.0 or more, and a distance between each of the gap of the square rack cells in adjacent with each other satisfies a predetermined condition. One example of the content is that B is from 0.05 to 0.75%, Gd is from 0.05 to 1.50%, C is 0.03% or less, Si is 1.0% or less, Mn is from 0.1 to 2.0%, P is 0.03% or less, S is 0.01% or less, Cr is from 18 to 26%, Ni is from 7 to 22% and Al is 0.1% or less. The distance between the rack cells can be reduced by using a material improved with thermal neutron absorbing performance by determining the boron equivalent to a predetermined value or more and with less B-content and good fabricability. In addition, the size of the rack cell itself can be reduced. This can greatly reduce the nuclear fuel storage area. (I.S.)

  14. Constant strength fuel-fuel cell

    International Nuclear Information System (INIS)

    Vaseen, V.A.

    1980-01-01

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

  15. Reproduction of the RA reactor fuel element fabrication

    International Nuclear Information System (INIS)

    Novakovic, M.

    1961-12-01

    This document includes the following nine reports: Final report on task 08/12 - testing the Ra reactor fuel element; design concept for fabrication of RA reactor fuel element; investigation of the microstructure of the Ra reactor fuel element; Final report on task 08/13 producing binary alloys with Al, Mo, Zr, Nb and B additions; fabrication of U-Al alloy; final report on tasks 08/14 and 08/16; final report on task 08/32 diffusion bond between the fuel and the cladding of the Ra reactor fuel element; Final report on task 08/33, fabrication of the RA reactor fuel element cladding; and final report on task 08/36, diffusion of solid state metals [sr

  16. Evolution of dispersion fuel meat structure caused by interface reaction

    International Nuclear Information System (INIS)

    Xing Zhonghu; Ying Shihao

    2000-01-01

    In reactor operation, the resultant layers are formed by interdiffusion at the fuel particle-matrix interfaces of U 3 Si 2 -Al dispersion fuel. This results in the evolution of meat structure. On the basis of Monte-Carlo method, the author developed simulation method of fuel meat, and simulated the stochastic space locations of spherical fuel particles in the meat. The fuel volume fraction is 43%, and the particles are in definite size distribution. For the 13551 simulated particle samples, the evolution of meat structure is calculated with layer thickness ranging from 0 to 16 μm. The parameters of meat structure include the U 3 Si 2 fuel volume fraction, resultant layer volume fraction, Al matrix volume fraction, particle contact probability and overlap degree as functions of layer thickness

  17. Bankole et al (2)

    African Journals Online (AJOL)

    DELL

    Relationships of Clay-filled Channels on the Delta Flanks (Modified after Doust and Omatsola, 1990 and Lawrence et al., 2002). ... and in the Indo-Malaysian area (Germeraad et al.,. 1968). The genus ..... Upper Cretaceous of British Guiana.

  18. Lou Gehrig's Disease (ALS)

    Science.gov (United States)

    ... disease. Who Gets ALS? Although this disease can strike anyone, ALS is extremely rare in kids. According ... home to provide care that the family cannot handle alone. Living With Lou Gehrig's Disease Living with ...

  19. Aussprache als motorische Fertigkeit

    DEFF Research Database (Denmark)

    Bonner, Maria

    2013-01-01

    Authentische Aussprache gilt im Fremdsprachenunterricht als schwer erreichbares Ziel, fremdsprachlicher Akzent wird als nahezu unvermeidbar gesehen. Weder die Hypothese einer kritischen Periode für den Erwerb einer authentischen Aussprache noch das Konzept der Fossilierung im Sprachlernprozess...

  20. DESIGN OF A LOW POWER SYSTEM BASED ON FUEL CELLS DISEÑO DE UN SISTEMA DE BAJA POTENCIA BASADO EN CELDAS DE COMBUSTIBLE DESENHO DE UM SISTEMA DE BAIXA POTÊNCIA BASEADO EM CÉLULAS DE COMBUSTÍVEL

    Directory of Open Access Journals (Sweden)

    Verónica Álvarez

    2012-06-01

    Full Text Available The design of a low power system based on a fuel cell and the series interconnection topology is proposed in this paper. The detailed design of the power electronics devices, the small signal and dynamic modeling of the system, and the associated control structures specification, design, and analysis are presented. The converters are designed to protect the fuel cell from current harmonics and high frequency transients, and to provide regulated voltage to the load, which could exhibits both steady state and transient current profiles. The proposed design procedure is applicable to any power system based on fuel cells, and it is illustrated with an experimental H-30 fuel cell prototype, providing satisfactory detailed PSIM simulation and experimental results that validate the paper contributions.Este artículo presenta el diseño de un sistema de baja potencia basado en pilas de combustible y la topología de interconexión en serie. El artículo incluye el diseño detallado de los dispositivos de electrónica de potencia, el modelado dinámico y de pequeña señal del sistema y la especificación, diseño y análisis de las estructuras de control de los convertidores, que son diseñados para proteger la pila de combustible de los armónicos de corriente y los transitorios de alta frecuencia, además para garantizar un voltaje regulado en la carga, el cual puede exhibir perfiles de corriente de estado estable y transitorios. El diseño propuesto es aplicable a cualquier sistema de potencia basado en pilas de combustible y es ilustrado con la pila de combustible H-30, que muestra resultados satisfactorios en un ambiente de simulación con el software PSIM y en el prototipo experimental, los cuales validan las contribuciones del artículo.Este artigo apresenta o desenho de um sistema de baixa potência baseado em pilhas de combustível e a topologia de interconexão em série. O artigo inclui o desenho detalhado dos dispositivos de eletrônica de

  1. Amyotrophic lateral sclerosis (ALS)

    Science.gov (United States)

    Lou Gehrig disease; ALS; Upper and lower motor neuron disease; Motor neuron disease ... One out of 10 cases of ALS is due to a genetic defect. The cause is unknown in most other cases. In ALS, motor nerve cells (neurons) waste away ...

  2. KMRR fuel design

    International Nuclear Information System (INIS)

    Son, D.S.; Sim, B.S.; Kim, T.R.; Hwang, W.; Kim, B.G.; Ku, Y.H.; Lee, C.B.; Lim, I.C.

    1992-06-01

    KMRR fuel rod design criteria on fuel swelling, blistering and oxide spallation have been reexamined. Fuel centerline temperature limit of 250deg C in normal operation condition and fuel swelling limit of 12 % at the end of life have been proposed to prevent fuel failure due to excessive fuel swelling. Fuel temperature limit of 485deg C has been proposed to exclude the possibility of fuel failures during transients or under accident condition. Further analyses are needed to decide the fuel cladding temperature limit to preclude the oxide spallation. Design changes in fuel assembly structure and their effects on related systems have been reviewed from a structural integrity viewpoint. The remained works in fuel mechanical design area have been identified and further efforts of fuel design group will be focused on these aspects. (Author)

  3. Fuel Property Blend Model

    Energy Technology Data Exchange (ETDEWEB)

    Pitz, William J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Mehl, Marco [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Wagnon, Scott J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Zhang, Kuiwen [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Kukkadapu, Goutham [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Westbrook, Charles K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-01-12

    The object of this project is to develop chemical models and associated correlations to predict the blending behavior of bio-derived fuels when mixed with conventional fuels like gasoline and diesel fuels.

  4. Logistic Fuel Processor Development

    National Research Council Canada - National Science Library

    Salavani, Reza

    2004-01-01

    The Air Base Technologies Division of the Air Force Research Laboratory has developed a logistic fuel processor that removes the sulfur content of the fuel and in the process converts logistic fuel...

  5. Fuel pellet loading apparatus

    International Nuclear Information System (INIS)

    1980-01-01

    Apparatus is described for loading a predetermined amount of nuclear fuel pellets into nuclear fuel elements and particularly for the automatic loading of fuel pellets from within a sealed compartment. (author)

  6. Fuel assembly

    International Nuclear Information System (INIS)

    Wataumi, Kazutoshi; Tajiri, Hiroshi.

    1992-01-01

    In a fuel assembly of a BWR type reactor, a pellet to be loaded comprises an external layer of fissile materials containing burnable poisons and an internal layer of fissile materials not containing burnable poison. For example, there is provided a dual type pellet comprising an external layer made of UO 2 incorporated with Gd 2 O 3 at a predetermined concentration as the burnable poisons and an internal layer made of UO 2 not containing Gd 2 O 3 . The amount of the burnable poisons required for predetermined places is controlled by the thickness of the ring of the external layer. This can dissipate an unnecessary poisoning effect at the final stage of the combustion cycle. Further, since only one or a few kinds of powder mixture of the burnable poisons and the fissile materials is necessary, production and product control can be facilitated. (I.N.)

  7. Nuclear fuel replacement device

    International Nuclear Information System (INIS)

    Ritz, W.C.; Robey, R.M.; Wett, J.F.

    1984-01-01

    A fuel handling arrangement for a liquid metal cooled nuclear reactor having a single rotating plug eccentric to the fuel core and a fuel handling machine radially movable along a slot in the plug with a transfer station disposed outside the fuel core but covered by the eccentric plug and within range of movement of said fuel handling machine to permit transfer of fuel assemblies between the core and the transfer station. (author)

  8. CANDU fuel performance

    International Nuclear Information System (INIS)

    Ivanoff, N.V.; Bazeley, E.G.; Hastings, I.J.

    1982-01-01

    CANDU fuel has operated successfully in Ontario Hydro's power reactors since 1962. In the 19 years of experience, about 99.9% of all fuel bundles have performed as designed. Most defects occurred before 1979 and subsequent changes in fuel design, fuel management, reactor control, and manufacturing quality control have reduced the current defect rate to near zero. Loss of power production due to defective fuel has been negligible. The outstanding performance continues while maintaining a low unit energy cost for fuel

  9. Fuels Combustion Research: Supercritical Fuel Pyrolysis

    National Research Council Canada - National Science Library

    Glassman, Irvin

    2001-01-01

    .... The focus during the subject period was directed to understanding the pyrolysis and combustion of endothermic fuels under subcritical conditions and the pyrolysis of these fuels under supercritical conditions...

  10. Fuels Combustion Research: Supercritical Fuel Pyrolysis

    National Research Council Canada - National Science Library

    Glassman, Irvin

    2000-01-01

    .... The focus during the subject period was directed to understanding the pyrolysis and combustion of endothermic fuels under subcritical conditions and the pyrolysis of these fuels under supercritical conditions...

  11. GSPEL - Fuel Cell Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The Fuel Cell Lab (FCL)Established to investigate, integrate, testand verifyperformance and technology readiness offuel cell systems and fuel reformers for use with...

  12. Fuel performance experience

    International Nuclear Information System (INIS)

    Sofer, G.A.

    1986-01-01

    The history of LWR fuel supply has been characterized by a wide range of design developments and fuel cycle cost improvements. Exxon Nuclear Company, Inc. has pursued an aggressive fuel research and development program aimed at improved fuel performance. Exxon Nuclear has introduced many design innovations which have improved fuel cycle economics and operating flexibility while fuel failures remain at very low levels. The removable upper tie plate feature of Exxon Nuclear assemblies has helped accelerate this development, enabling repeated inspections during successive plant outages. Also, this design feature has made it possible to repair damaged fuel assemblies during refueling outages, thereby minimizing the economic impact of fuel failure from all causes

  13. Catalytic Fuel Conversion Facility

    Data.gov (United States)

    Federal Laboratory Consortium — This facility enables unique catalysis research related to power and energy applications using military jet fuels and alternative fuels. It is equipped with research...

  14. HTGR fuel reprocessing technology

    International Nuclear Information System (INIS)

    Brooks, L.H.; Heath, C.A.; Shefcik, J.J.

    1976-01-01

    The following aspects of HTGR reprocessing technology are discussed: characteristics of HTGR fuels, criteria for a fuel reprocessing flowsheet; selection of a reference reprocessing flowsheet, and waste treatment

  15. Thermal conductivity of fresh and irradiated U-Mo fuels

    Science.gov (United States)

    Huber, Tanja K.; Breitkreutz, Harald; Burkes, Douglas E.; Casella, Amanda J.; Casella, Andrew M.; Elgeti, Stefan; Reiter, Christian; Robinson, Adam. B.; Smith, Frances. N.; Wachs, Daniel. M.; Petry, Winfried

    2018-05-01

    The thermal conductivity of fresh and irradiated U-Mo dispersion and monolithic fuel has been investigated experimentally and compared to theoretical models. During in-pile irradiation, thermal conductivity of fresh dispersion fuel at a temperature of 150 °C decreased from 59 W/m·K to 18 W/m·K at a burn-up of 4.9·1021 f/cc and further to 9 W/m·K at a burn-up of 6.1·1021 f/cc. Fresh monolithic fuel has a considerably lower thermal conductivity of 15 W/m·K at a temperature of 150 °C and consequently its decrease during in-pile irradiation is less steep than for dispersion fuel. For a burn-up of 3.5·1021 f/cc of monolithic fuel, a thermal conductivity of 11 W/m·K at a temperature of 150 °C has been measured by Burkes et al. (2015). The difference of decrease for both fuels originates from effects in the matrix that occur during irradiation, like for dispersion fuel the gradual disappearance of the Al matrix with increased burn-up and the subsequent growth of an interaction layer (IDL) between the U-Mo fuel particle and Al matrix and subsequent matrix hardening. The growth of fission gas bubbles and the decomposition of the U-Mo crystal lattice also affect both dispersion and monolithic fuel.

  16. Production of jet fuel from alternative source

    Energy Technology Data Exchange (ETDEWEB)

    Eller, Zoltan; Papp, Anita; Hancsok, Jenoe [Pannonia Univ., Veszprem (Hungary). MOL Dept. of Hydrocarbon and Coal Processing

    2013-06-01

    Recent demands for low aromatic content jet fuels have shown significant increase in the last 20 years. This was generated by the growing of aviation. Furthermore, the quality requirements have become more aggravated for jet fuels. Nowadays reduced aromatic hydrocarbon fractions are necessary for the production of jet fuels with good burning properties, which contribute to less harmful material emission. In the recent past the properties of gasolines and diesel gas oils were continuously severed, and the properties of jet fuels will be more severe, too. Furthermore, it can become obligatory to blend alternative components into jet fuels. With the aromatic content reduction there is a possibility to produce high energy content jet fuels with the desirable properties. One of the possibilities is the blending of biocomponents from catalytic hydrogenation of triglycerides. Our aim was to study the possibilities of producing low sulphur and aromatic content jet fuels in a catalytic way. On a CoMo/Al{sub 2}O{sub 3} catalyst we studied the possibilities of quality improving of a kerosene fraction and coconut oil mixture depending on the change of the process parameters (temperature, pressure, liquid hourly space velocity, volume ratio). Based on the quality parameters of the liquid products we found that we made from the feedstock in the adequate technological conditions products which have a high smoke point (> 35 mm) and which have reduced aromatic content and high paraffin content (90%), so these are excellent jet fuels, and their stack gases damage the environment less. (orig.)

  17. Stability Study of the RERTR Fuel Microstructure

    Energy Technology Data Exchange (ETDEWEB)

    Jian Gan; Dennis Keiser; Brandon Miller; Daniel Wachs

    2014-04-01

    The irradiation stability of the interaction phases at the interface of fuel and Al alloy matrix as well as the stability of the fission gas bubble superlattice is believed to be very important to the U-Mo fuel performance. In this paper the recent result from TEM characterization of Kr ion irradiated U-10Mo-5Zr alloy will be discussed. The focus will be on the phase stability of Mo2-Zr, a dominated second phase developed at the interface of U-10Mo and the Zr barrier in a monolithic fuel plate from fuel fabrication. The Kr ion irradiations were conducted at a temperature of 200 degrees C to an ion fluence of 2.0E+16 ions/cm2. To investigate the thermal stability of the fission gas bubble superlattice, a key microstructural feature in both irradiated dispersion U-7Mo fuel and monolithic U-10Mo fuel, a FIB-TEM sample of the irradiated U-10Mo fuel (3.53E+21 fission/cm3) was used for a TEM in-situ heating experiment. The preliminary result showed extraordinary thermal stability of the fission gas bubble superlattice. The implication of the TEM observation from these two experiments on the fuel microstructural evolution under irradiation will be discussed.

  18. Thermally induced dispersion mechanisms for aluminum-based plate-type fuels under rapid transient energy deposition

    International Nuclear Information System (INIS)

    Georgevich, V.; Taleyarkham, R.P.; Navarro-Valenti, S.; Kim, S.H.

    1995-01-01

    A thermally induced dispersion model was developed to analyze for dispersive potential and determine onset of fuel plate dispersion for Al-based research and test reactor fuels. Effect of rapid energy deposition in a fuel plate was simulated. Several data types for Al-based fuels tested in the Nuclear Safety Research Reactor in Japan and in the Transient Reactor Test in Idaho were reviewed. Analyses of experiments show that onset of fuel dispersion is linked to a sharp rise in predicted strain rate, which futher coincides with onset of Al vaporization. Analysis also shows that Al oxidation and exothermal chemical reaction between the fuel and Al can significantly affect the energy deposition characteristics, and therefore dispersion onset connected with Al vaporization, and affect onset of vaporization

  19. The Microstructure of Multi-wire U-Mo Monolithic Fuel

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Yoon Sang; Park, Eun Kee; Cho, Woo Hyoung; Park, Jong Man [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2010-10-15

    In order to use low-enriched uranium (LEU) instead of highly enriched uranium (HEU) for high performance research reactors, the reduced enrichment for research and test reactors (RERTR) program is developing high uranium density fuel such as U-Mo/Al dispersion fuel. U-Mo alloys have an excellent irradiation performance when compared to other uranium alloys or compounds. But the results from the post-irradiation examination of the U-Mo/Al dispersion fuels indicate that an interaction between the U-Mo alloy fuel and the Al matrix phases occurs readily during an irradiation and it is sensitively dependent on the temperature. In order to lessen these severe interactions, a concept of a multi-wire type fuel was proposed. The fuel configuration is that three to six U-Mo fuel wires (1.5 mm {approx} 2 mm in diameter) are symmetrically arranged at the periphery side in the Al matrix as shown. This multi-wire fuels showed very good fuel performance during the KOMO-3 irradiation test. At the KOMO-3 test, the specimen of the multi-wire fuels were U-7Mo/Al and U-7Mo-1Si/Al. In this study we investigate the microstructure change of the U-7Mo and U-7Mo-1Ti with some variation of annealing conditions. In addition to this, we want to check the effect of adding Ti element to U-7Mo on the gamma phase stability

  20. Study of fuel control strategy based on an fuel behavior model for starting conditions; Nenryo kyodo model ni motozuita shidoji no nenryo hosei hosho ni tsuite no kosatsu

    Energy Technology Data Exchange (ETDEWEB)

    Nakajima, Y; Uchida, M; Iwano, H; Oba, H [Nissan Motor Co. Ltd., Tokyo (Japan)

    1997-10-01

    We have applied a fuel behavior model to a fuel injection system which we call SOFIS (Sophisticated and Optimized Fuel Injection System) so that we get air/fuel ratio control accuracy and good driveability. However the fuel behavior under starting conditions is still not clear. To meet low emission rules and to get better driveability under starting conditions, better air/fuel ratio control is necessary. Now we have understood the ignition timing, injection timing, and injection pulse width required in such conditions. In former days, we analyzed the state of the air/fuel mixture under cold conditions and made a new fuel behavior model which considered fuel loss such as hydrocarbons and dissolution into oil and so on. Al this time, we have applied this idea to starting. We confirm this new model offers improved air/fuel ratio control. 6 refs., 9 figs., 3 tabs.

  1. Nuclear fuel production

    International Nuclear Information System (INIS)

    Randol, A.G.

    1985-01-01

    The production of new fuel for a power plant reactor and its disposition following discharge from the power plant is usually referred to as the ''nuclear fuel cycle.'' The processing of fuel is cyclic in nature since sometime during a power plant's operation old or ''depleted'' fuel must be removed and new fuel inserted. For light water reactors this step typically occurs once every 12-18 months. Since the time required for mining of the raw ore to recovery of reusable fuel materials from discharged materials can span up to 8 years, the management of fuel to assure continuous power plant operation requires simultaneous handling of various aspects of several fuel cycles, for example, material is being mined for fuel to be inserted in a power plant 2 years into the future at the same time fuel is being reprocessed from a discharge 5 years prior. Important aspects of each step in the fuel production process are discussed

  2. Evaluation of practicability of aluminosilicate additive fuel. Influence of aluminosilicate for reprocessing and corrosion of pellet

    International Nuclear Information System (INIS)

    Matsunaga, Junji; Kashibe, Shinji; Kinoshita, Mika; Ishimoto, Shinji; Harada, Kenichi

    2014-01-01

    Al-Si-O additive fuel is a modified pellet to improve the pellet-cladding interaction (PCI) resistance. This practicability assessment concerns the effect of Al-Si-O addition on the reprocessing and steam corrosion behavior. To address these concerns, a fuel dissolution test in nitric acid and a pellet corrosion test in humidified gas were carried out using the irradiated Al-Si-O additive fuel. Regardless of the Al-Si-O concentration, the dissolution rates of all Al-Si-O additive fuels were faster than that of the standard fuel. The morphology of the insoluble residue obtained from the irradiated Al-Si-O additive fuel could be considered as acceptable for retrieval by the clarification process using a conventional precipitation model. The corrosion resistance of the irradiated Al-Si-O additive fuel to high-temperature (at 1273 K) humidified gas was comparable to or better than that of the standard fuel. The result was interpreted as being due to a large grain size effect by Al-Si-O addition. (author)

  3. Fuel manufacturing and utilization

    International Nuclear Information System (INIS)

    2005-01-01

    The efficient utilisation of nuclear fuel requires manufacturing facilities capable of making advanced fuel types, with appropriate quality control. Once made, the use of such fuels requires a proper understanding of their behaviour in the reactor environment, so that safe operation for the design life can be achieved. The International Atomic Energy Agency supports Member States to improve in-pile fuel performance and management of materials; and to develop advanced fuel technologies for ensuring reliability and economic efficiency of the nuclear fuel cycle. It provides assistance to Member States to support fuel-manufacturing capability, including quality assurance techniques, optimization of manufacturing parameters and radiation protection. The IAEA supports the development fuel modelling expertise in Member States, covering both normal operation and postulated and severe accident conditions. It provides information and support for the operation of Nuclear Power Plant to ensure that the environment and water chemistry is appropriate for fuel operation. The IAEA supports fuel failure investigations, including equipment for failed fuel detection and for post-irradiation examination and inspection, as well as fuel repair, it provides information and support research into the basic properties of fuel materials, including UO 2 , MOX and zirconium alloys. It further offers guidance on the relationship with back-end requirement (interim storage, transport, reprocessing, disposal), fuel utilization and management, MOX fuels, alternative fuels and advanced fuel technology

  4. Ethanol from sugar cane bagasse. Contribution to atmospheric CO[sub 2] decrease. El etanol de bagazo como combustible. Contribucion a la reduccion del CO[sub 2] atmosferico

    Energy Technology Data Exchange (ETDEWEB)

    Cardenas, G.J. (Estacion Experimental Agroindustrial Obispo Colombres. Tucuman (Argentina))

    1993-03-01

    The current problem related to the increasing concentration of atmospheric CO[sub 2] produced by the industrial use of fossil fuels is reviewed. An analysis of the contribution that the use of ethanol from sugar cane bagasse might have on CO[sub 2] decrease is described. (Author)

  5. 143 - 148_Makeri et al.

    African Journals Online (AJOL)

    USER

    2015-06-01

    Jun 1, 2015 ... Yuan et al., 2003), antimicrobial activity (Sundarrao et al., 1993; Betancur-Galvis et al., 1999; Takashi et al., 2006), anti-parasitic, anti-malarial activities (Alali et al., 1998; Jaramillo et al., 2000; Luna et al.,. 2005). This study evaluates the antibacterial activity of extract of stem –bark and leaf extracts of Annona.

  6. LOS APORTES DEL TRABAJO SOCIAL AL TEMA DE FAMILIA

    Directory of Open Access Journals (Sweden)

    Angela María Quintero Velásquez

    2012-08-01

    Full Text Available El artículo presenta las contribuciones del Trabajo Social en los procesos familiares del continente. Refiere modalidades de la acción tales como: economapa. formas alternativas de enfrentar los conflictos socio-familiares, grupos psicoeducativos, redes. Precisa algunos elementos de la intervención: constructivismo, enfoque de convergencia (interinstitucionalidad, intersectorialidad, interdisciplinariedad, cibernética, relaciones ecosistemicas. la familia como sistema social.

  7. Instrumentation of fuel elements and fuel plates

    International Nuclear Information System (INIS)

    Durand, J.P.; Fanjas, Y.

    1993-01-01

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

  8. Instrumentation of fuel elements and fuel plates

    International Nuclear Information System (INIS)

    Durand, J.P.; Fanjas, Y.

    1994-01-01

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

  9. Abu al-Layth al-Libi

    Science.gov (United States)

    2015-02-01

    success. As an Arab participant acknowledged very early on, “the situation was really harsh. All the brothers were tired,” as they lacked food and... glorious battles that occurred during the early Islamic period.133 He stressed the importance of the battlefield as the path to achieve honor and dignity...diaspora in Waziristan. In the words of Walid Othmani, a French jihadi trained by al-Qa`ida in Waziristan in 2008, “[Al-Libi] was someone well-known and

  10. Sipping test on a failed MTR fuel element

    International Nuclear Information System (INIS)

    Terremoto, Luis Antonio Albiac; Zeituni, Carlos Alberto; Silva, Antonio Teixeira e; Perrotta, Jose Augusto; Silva, Jose Eduardo Rosa da

    2002-01-01

    This work describes sipping tests performed on MTR fuel elements of the IEA-R1 research reactor, in order to determinate which one failed in the core during a routine operation of the reactor. radioactive iodine isotopes 131 I and 133 I, employed as failure indicators, were detected in samples corresponding to the fuel element IEA-156. The specific activity of each sample, as well as the average leaking rate, were measured for 137 Cs. The nuclear fuels U 3 O 8 - Al dispersion and U - Al alloy were compared concerning their measured average leaking rates of 137 Cs. (author)

  11. Full core operation in JRR-3 with LEU fuels

    International Nuclear Information System (INIS)

    Murayama, Y.; Issiki, M.

    1995-01-01

    The new JRR-3 a 20MWT swimming pool type research reactor, is made up of plate type LEU fuel elements with U-Al x fuel at 2.2 gU/cm 3 . Reconstruction work for the new JR-3 was a good success, and common operation started in November 1990, and 7 cycles (26 days operation/cycle) have passed. We have no experience in using such a high uranium density fuel element with aluminide fuel. So we plan to examine the condition of the irradiated fuel elements with three methods, that is, measurement of the value of FFD in operation, observation of external view of the fuels in refueling work and postirradiation examination after maximum burn-up will be established. In the results of the first two methods, the fuel elements of JRR-3 is burned up normally and have no evidence of failure. (author)

  12. HTGR fuel and fuel cycle technology

    International Nuclear Information System (INIS)

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

    1976-08-01

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

  13. Onojeghuo et al (16)

    African Journals Online (AJOL)

    USER

    COMMUNITY PARTICIPATION IN FOREST MANAGEMENT ACROSS. PROTECTED AREAS ... With the right training on appropriate methods of .... Science Handbook (Irish, 2000). In order to .... resources for fuel wood, stake pole production,.

  14. Waste Not, Want Not: Lactate Oxidation Fuels the TCA Cycle.

    Science.gov (United States)

    Martínez-Reyes, Inmaculada; Chandel, Navdeep S

    2017-12-05

    Previous studies have demonstrated that mitochondrial respiration is essential for tumorigenesis. Hui et al. (2017) and Faubert et al. (2017) demonstrate that lactate, traditionally viewed as a waste product of anaerobic and aerobic glycolysis, is a major carbon source to fuel the mitochondrial TCA cycle in normal tissue and in tumors. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. HTGR fuel and fuel cycle technology

    International Nuclear Information System (INIS)

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

    1977-01-01

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

  16. Treat upgrade fuel fabrication

    International Nuclear Information System (INIS)

    Davidson, K.V.; Schell, D.H.

    1979-01-01

    An extrusion and thermal treatment process was developed to produce graphite fuel rods containing a dispersion of enriched UO 2 . These rods will be used in an upgraded version of the Transient Reactor Test Facility (TREAT). The improved fuel provides a higher graphite matrix density, better fuel dispersion and higher thermal capabilities than the existing fuel

  17. Integrated fuel processor development

    International Nuclear Information System (INIS)

    Ahmed, S.; Pereira, C.; Lee, S. H. D.; Krumpelt, M.

    2001-01-01

    The Department of Energy's Office of Advanced Automotive Technologies has been supporting the development of fuel-flexible fuel processors at Argonne National Laboratory. These fuel processors will enable fuel cell vehicles to operate on fuels available through the existing infrastructure. The constraints of on-board space and weight require that these fuel processors be designed to be compact and lightweight, while meeting the performance targets for efficiency and gas quality needed for the fuel cell. This paper discusses the performance of a prototype fuel processor that has been designed and fabricated to operate with liquid fuels, such as gasoline, ethanol, methanol, etc. Rated for a capacity of 10 kWe (one-fifth of that needed for a car), the prototype fuel processor integrates the unit operations (vaporization, heat exchange, etc.) and processes (reforming, water-gas shift, preferential oxidation reactions, etc.) necessary to produce the hydrogen-rich gas (reformate) that will fuel the polymer electrolyte fuel cell stacks. The fuel processor work is being complemented by analytical and fundamental research. With the ultimate objective of meeting on-board fuel processor goals, these studies include: modeling fuel cell systems to identify design and operating features; evaluating alternative fuel processing options; and developing appropriate catalysts and materials. Issues and outstanding challenges that need to be overcome in order to develop practical, on-board devices are discussed

  18. Methanol Fuel Cell

    Science.gov (United States)

    Voecks, G. E.

    1985-01-01

    In proposed fuel-cell system, methanol converted to hydrogen in two places. External fuel processor converts only part of methanol. Remaining methanol converted in fuel cell itself, in reaction at anode. As result, size of fuel processor reduced, system efficiency increased, and cost lowered.

  19. Pornographie als Metapher

    Directory of Open Access Journals (Sweden)

    Caroline Schubarth

    2010-02-01

    Full Text Available In diesem Artikel werden unterschiedliche metaphorische Verwendungen des Pornografiebegriffs und deren Implikationen untersucht. Während die Existenz von Pornografie der feministischen Anti-Porno-Bewegung als Erklärung für die anhaltende Diskriminierung von Frauen in westlichen Gesellschaften dient, nutzen rechtskonservative Kräfte den Pornografievorwurf als Rechtfertigung für die Zensur von als deviant empfundenen Identitäten und sexuellen Praktiken.

  20. Tribological Properties of Ti(Al,O)/Al2O3 Composite Coating by Thermal Spraying

    Science.gov (United States)

    Salman, Asma; Gabbitas, Brian; Cao, Peng; Zhang, Deliang

    The use of thermal spray coatings provides protection to the surfaces operating in severe environments. The main goal of the current work is to investigate the possibility of using a high velocity air fuel (HVAF) thermally sprayed wear resistant Ti(Al,O)/Al2O3 coating on tool steel (H13) which is used for making dies for aluminium high pressure die casting and dummy blocks aluminium extrusion. A feedstock of Ti(Al,O)/Al2O3 composite powder was produced from a mixture of Al and TiO2 powders by high energy mechanical milling, followed by a thermal reaction process. The feedstock was then thermally sprayed using a high velocity air-fuel (HVAF) technique onto H13 steel substrates to produce a composite coating. The present study describes and compares the tribological properties such as friction and sliding wear rate of the coating both at room and high temperature (700°C). The wear resistance of the coating was investigated by a tribometer using a spherical ended alumina pin as a counter body under dry and lubricating conditions. The results showed that composite coating has lower wear rate at high temperature than at room temperature without using lubricant. The composite coating was characterized using scanning electron microscopy (SEM), optical microscopy and X-ray diffractometry (XRD). This paper reports the experimental observations and discusses the wear resistance performance of the coatings at room and high temperatures.

  1. Reactor fueling system

    International Nuclear Information System (INIS)

    Hattori, Noriaki; Hirano, Haruyoshi.

    1983-01-01

    Purpose: To optimally position a fuel catcher by mounting a television camera to a fuel catching portion and judging video images by the use of a computer or the like. Constitution: A television camera is mounted to the lower end of a fuel catching mechanism for handling nuclear fuels and a fuel assembly disposed within a reactor core or a fuel storage pool is observed directly from above to judge the position for the fuel assembly by means of video signals. Then, the relative deviation between the actual position of the fuel catcher and that set in a memory device is determined and the positional correction is carried out automatically so as to reduce the determined deviation to zero. This enables to catch the fuel assembly without failure and improves the efficiency for the fuel exchange operation. (Moriyama, K.)

  2. Nuclear fuel elements

    International Nuclear Information System (INIS)

    Nakai, Keiichi

    1983-01-01

    Purpose: To decrease the tensile stresses resulted in a fuel can as well as prevent decladding of fuel pellets into the bore holes by decreasing the inner pressure within the nuclear fuel element. Constitution: A fuel can is filled with hollow fuel pellets, inserted with a spring for retaining the hollow fuel pellets with an appropriate force and, thereafter, closely sealed at the both ends with end plugs. A cylindrical body is disposed into the bore holes of the hollow fuel pellets. Since initial sealing gases and/or gaseous nuclear fission products can thus be excluded from the bore holes where the temperature is at the highest level, the inner pressure of the nuclear fuel element can be reduced to decrease the tensile strength resulted to the fuel can. Furthermore, decladding of fuel pellets into the bore holes can be prevented. (Moriyama, K.)

  3. Failed fuel rod detector

    Energy Technology Data Exchange (ETDEWEB)

    Uchida, Katsuya; Matsuda, Yasuhiko

    1984-05-02

    The purpose of the project is to enable failed fuel rod detection simply with no requirement for dismantling the fuel assembly. A gamma-ray detection section is arranged so as to attend on the optional fuel rods in the fuel assembly. The fuel assembly is adapted such that a gamma-ray shielding plate is detachably inserted into optional gaps of the fuel rods or, alternatively, the fuel assembly can detachably be inserted to the gamma-ray shielding plate. In this way, amount of gaseous fission products accumulated in all of the plenum portions in the fuel rods as the object of the measurement can be determined without dismantling the fuel assembly. Accordingly, by comparing the amounts of the gaseous fission products, the failed fuel rod can be detected.

  4. 77 FR 13009 - Regulation of Fuels and Fuel Additives: Identification of Additional Qualifying Renewable Fuel...

    Science.gov (United States)

    2012-03-05

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

  5. Possíveis contribuições de Husserl e Heidegger para a clínica fenomenológica Possibles contribuciones de Husserl y Heidegger para la clínica fenomenológica Husserl´s and Heidegger´s possible contributions to clinical phenomenology

    Directory of Open Access Journals (Sweden)

    Virginia Moreira

    2010-12-01

    Full Text Available Este artigo tem como objetivo descrever as possíveis contribuições das filosofias de Edmund Husserl e Martin Heidegger para o desenvolvimento de uma clínica fenomenológica. Reconhece-se que Husserl, com sua Psicologia Fenomenológica, inaugura uma psicologia da subjetividade que pode servir de base para a clínica fenomenológica. O artigo também discute as contribuições e possíveis limitações das propostas clínicas de Ludwig Binswanger e Medard Boss, que procuram fundamentar-se na Analítica do Dasein de Heidegger, e propõe a fenomenologia existencial de Merleau-Ponty, que retoma o último pensamento de Husserl tendo como fio condutor o conceito de Lebenswelt, como um caminho fecundo para a clínica fenomenológica.Este artículo tiene como objetivo describir las posibles contribuciones de las filosofías de Edmund Husserl y Martin Heidegger para el desarrollo de una clínica fenomenológica. Reconoce que Husserl, con su Psicología Fenomenológica, inaugura una psicología de la subjetividad, que puede servir de base para la clínica fenomenológica. Discute las contribuciones y posibles limitaciones de las propuestas clínicas de Ludwig Binswanger y Medard Boss, que se proponen a tener como fundamentó la Analítica del Dasein de Heidegger. Sugiere la fenomenología existencial de Merleau-Ponty, que retoma el pensamiento del último Husserl teniendo como hilo conductor el concepto de Lebenswelt, como un camino fecundo para la clínica fenomenológica.This article aims to describe the possible contributions of Edmund Husserl´s and Martin Heidegger´s philosophies to the development of a phenomenological clinic. It recognizes that Husserl, with his Phenomenological Psychology, inaugurates a psychology of subjective, which may serve as basis to the phenomenological clinic. It discusses the contributions and possible limitations of Ludwig Binswanger´s and Medard Boss’s clinical proposals, which aim to be funded on Heidegger

  6. Irradiation performance of uranium-molybdenum alloy dispersion fuels

    International Nuclear Information System (INIS)

    Almeida, Cirila Tacconi de

    2005-01-01

    The U-Mo-Al dispersion fuels of Material Test Reactors (MTR) are analyzed in terms of their irradiation performance. The irradiation performance aspects are associated to the neutronic and thermal hydraulics aspects to propose a new core configuration to the IEA-R1 reactor of IPEN-CNEN/SP using U-Mo-Al fuels. Core configurations using U-10Mo-Al fuels with uranium densities variable from 3 to 8 gU/cm 3 were analyzed with the computational programs Citation and MTRCR-IEA R1. Core configurations for fuels with uranium densities variable from 3 to 5 gU/cm 3 showed to be adequate to use in IEA-R1 reactor e should present a stable in reactor performance even at high burn-up. (author)

  7. Hydrogen permeation in FeCrAl alloys for LWR cladding application

    Science.gov (United States)

    Hu, Xunxiang; Terrani, Kurt A.; Wirth, Brian D.; Snead, Lance L.

    2015-06-01

    FeCrAl, an advanced oxidation-resistant iron-based alloy class, is a highly prevalent candidate as an accident-tolerant fuel cladding material. Compared with traditional zirconium alloy fuel cladding, increased tritium permeation through FeCrAl fuel cladding to the primary coolant is expected, raising potential safety concerns. In this study, the hydrogen permeability of several FeCrAl alloys was obtained using a static permeation test station, which was calibrated and validated using 304 stainless steel. The high hydrogen permeability of FeCrAl alloys leads to concerns with respect to potentially significant tritium release when used for fuel cladding in LWRs. The total tritium inventory inside the primary coolant of a light water reactor was quantified by applying a 1-dimensional steady state tritium diffusion model to demonstrate the dependence of tritium inventory on fuel cladding type. Furthermore, potential mitigation strategies for tritium release from FeCrAl fuel cladding were discussed and indicate the potential for application of an alumina layer on the inner clad surface to serve as a tritium barrier. More effort is required to develop a robust, economical mitigation strategy for tritium permeation in reactors using FeCrAl clad fuel assemblies.

  8. Materials for fuel cells

    OpenAIRE

    Haile, Sossina M

    2003-01-01

    Because of their potential to reduce the environmental impact and geopolitical consequences of the use of fossil fuels, fuel cells have emerged as tantalizing alternatives to combustion engines. Like a combustion engine, a fuel cell uses some sort of chemical fuel as its energy source but, like a battery, the chemical energy is directly converted to electrical energy, without an often messy and relatively inefficient combustion step. In addition to high efficiency and low emissions, fuel cell...

  9. Advanced fuels safety comparisons

    International Nuclear Information System (INIS)

    Grolmes, M.A.

    1977-01-01

    The safety considerations of advanced fuels are described relative to the present understanding of the safety of oxide fueled Liquid Metal Fast Breeder Reactors (LMFBR). Safety considerations important for the successful implementation of advanced fueled reactors must early on focus on the accident energetics issues of fuel coolant interactions and recriticality associated with core disruptive accidents. It is in these areas where the thermal physical property differences of the advanced fuel have the greatest significance

  10. Neutronics analysis on mini test fuel in the RSG-GAS core

    International Nuclear Information System (INIS)

    Tukiran S; Tagor M Sembiring

    2016-01-01

    Research on UMo fuel for research reactor has been developed. The fuel of research reactor is uranium molybdenum low enrichment with high density. For supporting the development of fuel fabrication, an neutronic analysis of mini fuel plates in the RSG-GAS core was performed. The aim of analysis is to determine the numbers of fuel cycles in the core to know the maximum fuel burn-up. The mini fuel plates of U_7Mo-Al and U_6Zr-Al with densities of 7.0 gU/cc and 5.2 gU/cc, respectively, will be irradiated in the RSG-GAS core. The size of both fuels, namely 630 x 70.75 x 1.30 mm were inserted to the 3 plates of dummy fuel. Before the fuel will be irradiated in the core, a calculation for safety analysis from neutronics and thermal-hydraulics aspects were required. However, in this paper, it will be discussed safety analysis of the U_7Mo-Al and U_6Zr-Al mini fuels from neutronic point of view. The calculation was done using WIMSD-5B and Batan-3DIFF codes. The result showed that both of the mini fuels could be irradiated in the RSG-GAS core with burn up less than 70 % within 12 cycles of operation without over limiting the safety margin. If it is compared, the power density of U_7Mo-Al mini fuel is bigger than U_6Zr-Al fuel. (author)

  11. Use of plate fuel elements for the RA3 reactor

    International Nuclear Information System (INIS)

    Parodi, C.; Parkanski, D.; Higa, M.; Marajofsky, A.

    1992-01-01

    The RA3 reactor is a pool reactor, redesigned for 5 MW dissipation. Nineteen plates are used in each fuel element. The utilization of 20% enriched U, gives the possibility of the development of rod type fuel with Al/U 3 O 8 cermets. The thermohydraulic and neutronic conditions are studied in this work in order to satisfy the stipulated power. In addition, the fabrication conditions of Al/U 3 O 8 and Al/U 3 O 8 /Zr H 2 cermets with densities within the limits imposed by the thermohydraulics and neutronics conditions are studied. (author)

  12. Reduced enrichment fuels for Canadian research reactors - Fabrication and performance

    Energy Technology Data Exchange (ETDEWEB)

    Wood, J C; Foo, M T; Berthiaume, L C; Herbert, L N; Schaefer, J D; Hawley, D [Atomic Energy of Canada Limited, Chalk River Nuclear Laboratories, Chalk River, ON KOJ 1JO (Canada)

    1985-07-01

    Our facilities have been upgraded to manufacture fuel rods comprising dispersions of U{sub 3}Si in aluminum, to complement the dispersions of U{sub 3}Si alloyed with 1.5 and 3.0 wt% Al fabricated and tested previously. Further advances have been made in process optimization particularly in core extrusion where production rate has been doubled while maintaining high quality standards. Our mini-element irradiations of Al-61.5 wt% (U,3.5 wt% Si, 1.5 wt% Al) and Al-62.4 wt% (U,3.2 wt% Si, 30 wt% Al) have been completed successfully up to the terminal burnup of 93 atomic percent. Fuel core swelling remained marginally below 1% per 10 atomic percent burnup over the whole irradiation. Also mini-elements containing Al-72.4 wt% USiAl and Al-73.4 wt% USi*Al have been irradiated to 82 atomic percent burnup, their swelling rate marginally exceeding 1% per 10 atomic percent burnup. Three full-size 12-element NRU assemblies containing Al-62.4 wt% USi*Al have been fabricated and installed in the NRU reactor where they have performed normally without problems. The cores for four more full-size 12-element NRU assemblies containing Al-61.0 wt% U{sub 3}Si have been manufactured. (author)

  13. Reduced enrichment fuels for Canadian research reactors - Fabrication and performance

    International Nuclear Information System (INIS)

    Wood, J.C.; Foo, M.T.; Berthiaume, L.C.; Herbert, L.N.; Schaefer, J.D.; Hawley, D.

    1985-01-01

    Our facilities have been upgraded to manufacture fuel rods comprising dispersions of U 3 Si in aluminum, to complement the dispersions of U 3 Si alloyed with 1.5 and 3.0 wt% Al fabricated and tested previously. Further advances have been made in process optimization particularly in core extrusion where production rate has been doubled while maintaining high quality standards. Our mini-element irradiations of Al-61.5 wt% (U,3.5 wt% Si, 1.5 wt% Al) and Al-62.4 wt% (U,3.2 wt% Si, 30 wt% Al) have been completed successfully up to the terminal burnup of 93 atomic percent. Fuel core swelling remained marginally below 1% per 10 atomic percent burnup over the whole irradiation. Also mini-elements containing Al-72.4 wt% USiAl and Al-73.4 wt% USi*Al have been irradiated to 82 atomic percent burnup, their swelling rate marginally exceeding 1% per 10 atomic percent burnup. Three full-size 12-element NRU assemblies containing Al-62.4 wt% USi*Al have been fabricated and installed in the NRU reactor where they have performed normally without problems. The cores for four more full-size 12-element NRU assemblies containing Al-61.0 wt% U 3 Si have been manufactured. (author)

  14. Nuclear fuel storage facility

    International Nuclear Information System (INIS)

    Matsumoto, Takashi; Isaka, Shinji.

    1987-01-01

    Purpose: To increase the spent fuel storage capacity and reduce the installation cost in a nuclear fuel storage facility. Constitution: Fuels handled in the nuclear fuel storage device of the present invention include the following four types: (1) fresh fuels, (2) 100 % reactor core charged fuels, (3) spent fuels just after taking out and (4) fuels after a certain period (for example one half-year) from taking out of the reactor. Reactivity is high for the fuels (1), and some of fuels (2), while low in the fuels (3) (4), Source intensity is strong for the fuels (3) and some of the fuels (2), while it is low for the fuels (1) and (4). Taking notice of the fact that the reactivity, radioactive source intensity and generated after heat are different in the respective fuels, the size of the pool and the storage capacity are increased by the divided storage control. While on the other hand, since the division is made in one identical pool, the control method becomes important, and the working range is restricted by means of a template, interlock, etc., the operation mode of the handling machine is divided into four, etc. for preventing errors. (Kamimura, M.)

  15. Fuel pattern recognition device

    International Nuclear Information System (INIS)

    Sato, Tomomi.

    1995-01-01

    The device of the present invention monitors normal fuel exchange upon fuel exchanging operation carried out in a reactor of a nuclear power plant. Namely, a fuel exchanger is movably disposed to the upper portion of the reactor and exchanges fuels. An exclusive computer receives operation signals of the fuel exchanger during operation as inputs, and outputs reactor core fuel pattern information signals to a fuel arrangement diagnosis device. An underwater television camera outputs image signals of a fuel pattern in the reactor core to an image processing device. If there is any change in the image signals for the fuel pattern as a result of the fuel exchange operation of the fuel exchanger, the image processing device outputs the change as image signals to the fuel pattern diagnosis device. The fuel pattern diagnosis device compares the pattern information signals from the exclusive computer with the image signals from the image processing device, to diagnose the result of the fuel exchange operation performed by the fuel exchanger and inform the diagnosis by means of an image display. (I.S.)

  16. Numerical studies of spray combustion processes of palm oil biodiesel and diesel fuels using reduced chemical kinetic mechanisms

    KAUST Repository

    Kuti, Olawole; Sarathy, Mani; Nishida, Keiya; Roberts, William L.

    2014-01-01

    Spray combustion processes of palm oil biodiesel (PO) and conventional diesel fuels were simulated using the CONVERGE CFD code. Thermochemical and reaction kinetic data (115 species and 460 reactions) by Luo et al. (2012) and Lu et al. (2009) (68

  17. Improving performance with accident tolerant-fuels

    International Nuclear Information System (INIS)

    Gomes, Daniel S.; Muniz, Rafael O.R.; Giovedi, Claudia; Universidade de São Paulo

    2017-01-01

    After the Fukushima reactor accident, efforts to improve risk management in nuclear operations have included the intensification of research on accident-tolerant fuels (ATFs). In this investigation, the physical properties of recently developed ATFs were compared with those of the current standard fuel, UO 2 - Zr. The goals for innovative fuel design include a rigorous characterization of the thermal, mechanical, and chemical considerations. The intentions are to lengthen the burnup cycle, raise the power density, and improve safety. Fuels must have a high uranium density - above that supported by UO 2 - and possess a coating that exhibits better oxidation resistance than Zircaloys. ATFs such as U 3 Si 2 , UN, and UC contain a higher uranium density and thermal conductivity than UO 2 , providing significant benefits. The ideal combination of fuel and cladding must increase performance in a loss-of-coolant accident. However, U 3 Si 2 , UN, and UC have a disadvantage; their respective swelling rates are higher than that of UO 2 . These ATFs also have thermal conductivities approximately four times higher than that of UO 2 . A study was conducted investigating the hydrogen generated by the oxidation of zirconium alloys in contact with steam using cladding options such as Fe-Cr-Al and silicon carbide. It was confirmed that ferritic alloys offer a better response under severe conditions, because of their mechanical properties as creep rate. The findings of this study indicate that advanced fuels should replace UO 2 - Zr as the fuel system of choice. (author)

  18. An XRD technique for quantitative phase analysis of Al-U-Zr alloy

    International Nuclear Information System (INIS)

    Khan, K.B.; Kulkarni, N.K.; Jain, G.C.

    2003-01-01

    In several nuclear research reactors all over the world, Al-U alloy is used as fuel. To stabilise less brittle phase UAl 3 in Al-U alloy, a small amount of Zr (1 to 3 wt% ) is added. A rapid, non destructive and simple x-ray diffraction technique has been developed for quantitative phase analysis Al-U-Zr alloy system containing UAl 4 , UAl 3 and Al. (author)

  19. Alles is al uitgevonden

    NARCIS (Netherlands)

    J.G.M. van Marrewijk (Charles)

    1996-01-01

    textabstractDe voordelen van vrijhandel zijn zeer beperkt, al-thans als we de empirische schattingen van vooraanstaande economen en internationale organisaties mogen geloven. Zo worden de voordelen van liberalisatie voor de Europese Unie geraamd op ongeveer 0,5% van het bnp 1. De door het IMF

  20. Lukman et al. (5)

    African Journals Online (AJOL)

    DELL

    1 Civil Engineering Department, Obafemi Awolowo University, Ile-Ife- Nigeria and Corresponding author. 2Department of Water Resources and Environmental Engineering, Ahmadu Bello University, Samaru, Zaria- Nigeria s Department of Civil Engineering, University of Hafr Al-Batin, Hafr Al-Batin, Saudi Arabia.