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Sample records for reactor pbmr basado

  1. Conceptual design of a nucleo electric simulator with PBMR reactor based in Reduced order models; Diseno conceptual de un simulador de nucleo electrica con reactor PBMR basado en modelos de orden reducido

    Energy Technology Data Exchange (ETDEWEB)

    Valle H, J.; Morales S, J.B. [UNAM, DEPFI, Campus Morelos, en IMTA Jiutepec, Morelos (Mexico)]. e-mail: jms0620@yahoo.com

    2005-07-01

    This project has as purpose to know to depth the operation of a PBMR nucleo electric type (Pebble Bed Modular Reactor), which has a reactor of moderate graphite spheres and fuel of uranium dioxide cooled with Helium and Brayton thermodynamic cycle. The simulator seeks to describe the dynamics of the one process of energy generation in the nuclear fuel, the process of transport toward the coolant one and the conversion to mechanical energy in the turbo-generators as well as in the heat exchangers indispensable for the process. The dynamics of reload of the fuel elements it is not modeled in detail but their effects are represented in the parameters of the pattern. They are modeled also the turbo-compressors of the primary circuit of the work fluid. The control of the power of the nuclear reactor is modeled by means of reactivity functions specified in the simulation platform. The proposed mathematical models will be settled in the platform of simulation of Simulink-Mat Lab. The proposed control panels for this simulator can be designed and to implement using the box of tools of Simulink that facilitates this process. The work presents the mathematical models more important used for their future implementation in Simulink. (Author)

  2. Nuclear reactor PBMR and cogeneration; Reactor nuclear PBMR y cogeneracion

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez S, J. R.; Alonso V, G., E-mail: ramon.ramirez@inin.gob.mx [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2013-10-15

    In recent years the nuclear reactor designs for the electricity generation have increased their costs, so that at the moment costs are managed of around the 5000 US D for installed kw, reason for which a big nuclear plant requires of investments of the order of billions of dollars, the designed reactors as modular of low power seek to lighten the initial investment of a big reactor dividing the power in parts and dividing in modules the components to lower the production costs, this way it can begin to build a module and finished this to build other, differing the long term investment, getting less risk therefore in the investment. On the other hand the reactors of low power can be very useful in regions where is difficult to have access to the electric net being able to take advantage of the thermal energy of the reactor to feed other processes like the water desalination or the vapor generation for the processes industry like the petrochemical, or even more the possible hydrogen production to be used as fuel. In this work the possibility to generate vapor of high quality for the petrochemical industry is described using a spheres bed reactor of high temperature. (Author)

  3. Ion beam analysis of materials in the PBMR reactor

    Science.gov (United States)

    Malherbe, Johan B.; Friedland, E.; van der Berg, N. G.

    2008-04-01

    South Africa is developing a new type of high temperature nuclear reactor, the so-called pebble bed modular reactor (PBMR). The planned reactor outlet temperature of this gas-cooled reactor is approximately 900 °C. This high temperature places some severe restrictions on materials, which can be used. The name of the reactor is derived from the form of the fuel elements, which are in the form of pebbles, each with a diameter of 60 mm. Each pebble is composed of several thousands of coated fuel particles. The coated particle consists of a nucleus of UO2 surrounded by several layers of different carbons and SiC. The diameter of the fuel particles is 0.92 mm. A brief review will be given of the advantages of this nuclear reactor, of the materials in the fuel elements and their analysis using ion beam techniques.

  4. Nuclear Safeguards Considerations For The Pebble Bed Modular Reactor (PBMR)

    Energy Technology Data Exchange (ETDEWEB)

    Phillip Casey Durst; David Beddingfield; Brian Boyer; Robert Bean; Michael Collins; Michael Ehinger; David Hanks; David L. Moses; Lee Refalo

    2009-10-01

    High temperature reactors (HTRs) have been considered since the 1940s, and have been constructed and demonstrated in the United Kingdom (Dragon), United States (Peach Bottom and Fort Saint Vrain), Japan (HTTR), Germany (AVR and THTR-300), and have been the subject of conceptual studies in Russia (VGM). The attraction to these reactors is that they can use a variety of reactor fuels, including abundant thorium, which upon reprocessing of the spent fuel can produce fissile U-233. Hence, they could extend the stocks of available uranium, provided the fuel is reprocessed. Another attractive attribute is that HTRs typically operate at a much higher temperature than conventional light water reactors (LWRs), because of the use of pyrolytic carbon and silicon carbide coated (TRISO) fuel particles embedded in ceramic graphite. Rather than simply discharge most of the unused heat from the working fluid in the power plant to the environment, engineers have been designing reactors for 40 years to recover this heat and make it available for district heating or chemical conversion plants. Demonstrating high-temperature nuclear energy conversion was the purpose behind Fort Saint Vrain in the United States, THTR-300 in Germany, HTTR in Japan, and HTR-10 and HTR-PM, being built in China. This resulted in nuclear reactors at least 30% or more thermodynamically efficient than conventional LWRs, especially if the waste heat can be effectively utilized in chemical processing plants. A modern variant of high temperature reactors is the Pebble Bed Modular Reactor (PBMR). Originally developed in the United States and Germany, it is now being redesigned and marketed by the Republic of South Africa and China. The team examined historical high temperature and high temperature gas reactors (HTR and HTGR) and reviewed safeguards considerations for this reactor. The following is a preliminary report on this topic prepared under the ASA-100 Advanced Safeguards Project in support of the NNSA Next

  5. The Operator Training Simulator System for the Pebble Bed Modular Reactor (PBMR) Plant

    Energy Technology Data Exchange (ETDEWEB)

    Dudley, Trevor [Pebble Bed Modular Reactor (Proprietary) Limited, Pebble House, Centurion (South Africa)], E-mail: trevor.dudley@pbmr.co.za; Villiers, Piet de; Bouwer, Werner [Pebble Bed Modular Reactor (Proprietary) Limited, Pebble House, Centurion (South Africa); Luh, Robert [GSE Systems, Inc., 7133 Rutherford Suite 200, Baltimore, MD 21244 (United States)

    2008-11-15

    The Pebble Bed Modular Reactor (PBMR) is a First of a Kind Engineering with respect to the over 200 new innovations used in the design. The PBMR technical design is an inherited modified design from an earlier design such as the German 15 MWe AVR (Arbeitsgemeinschaft Versuchs Reaktor) and the THTR-300 MWe Thorium High Temperature Reactor (THTR), which ran in Germany as a test and research facility for 20 years. This paper discusses the Operator Training Simulator System for the PBMR Demonstration Power Plant. The Operator Training Simulator System will be used for operator training and licensing of plant operators. Included in the discussion is an overview of the major elements of the Operator Training Simulator System, including some of the main functional areas.

  6. DESAIN TERAS PLTN JENIS PEBBLE BED MODULAR REACTOR (PBMR) MENGGUNAKAN PAKET PROGRAM MCNP-5 PADA KONDISI BEGINNING OF LIFE

    OpenAIRE

    Ralind Re Marla; Yohannes Sardjono; Supardi Supardi

    2015-01-01

    Telah dilakukan desain teras Pembangkit Listrik Tenaga Nuklir (PLTN) untuk jenis Pebble Bed Modular Reactor (PBMR) dengan daya 70 MWe untuk keperluan proses smelter pada keadaan beginning of life (BOL). Analisis ini bertujuan untuk mengetahui persen pengkayaan, distribusi suhu dan nilai keselamatan dengan koefisien reaktivitas teras yang negatif pada reaktor jenis PBMR apabila daya reaktor 70 MWe. Analisis menggunakan program Monte Carlo N-Particle-5 (MCNP5) dan dari hasil analisis ini dihara...

  7. DESAIN TERAS PLTN JENIS PEBBLE BED MODULAR REACTOR (PBMR MENGGUNAKAN PAKET PROGRAM MCNP-5 PADA KONDISI BEGINNING OF LIFE

    Directory of Open Access Journals (Sweden)

    Ralind Re Marla

    2015-03-01

    Full Text Available Telah dilakukan desain teras Pembangkit Listrik Tenaga Nuklir (PLTN untuk jenis Pebble Bed Modular Reactor (PBMR dengan daya 70 MWe untuk keperluan proses smelter pada keadaan beginning of life (BOL. Analisis ini bertujuan untuk mengetahui persen pengkayaan, distribusi suhu dan nilai keselamatan dengan koefisien reaktivitas teras yang negatif pada reaktor jenis PBMR apabila daya reaktor 70 MWe. Analisis menggunakan program Monte Carlo N-Particle-5 (MCNP5 dan dari hasil analisis ini diharapkan dapat memenuhi syarat dalam mendukung program percepatan pembangunan kelistrikan batubara 10.000 MWe khususnya untuk proses smelter, yang tersebar merata di wilayah Indonesia. Hasil penelitian menunjukkan bahwa, faktor perlipatan efektif (k-eff Reaktor jenis PBMR daya 70 MWe mengalami kondisi kritis pada pengkayaan 5,626 % dengan nilai faktor perlipatan efektif 1,00031±0,00087 dan nilai koefisien reaktivitas suhu pada -10,0006 pcm/K. Dari hasil analisis daat disimpulkan bahwa reaktor jenis PBMR daya 70 MWe adalah aman.   ABSTRACT The core design of Nuclear Power Plant for Pebble Bed Modular Reactor (PBMR type with 70 MWe capacity power in Beginning of Life (BOL has been performed. The aim of this analysis, to know percent enrichment, temperature distribution and safety value by negative temperature coefficient at type PBMR if reactor power become lower equal to 70 MWe. This analysis was expected become one part of overview project development the power plant with 10.000 MWe of total capacity, spread evenly in territory of Indonesia especially to support of smelter industries. The results showed that, effective multiplication factor (keff with power 70 MWe critical condition at enrichment 5,626 %is 1,00031±0,00087, based on enrichment result, a value of the temperature coefficient reactivity is - 10,0006 pcm/K. Based on the results of these studies, it can beconcluded that the PBMR 70 MWe design is theoritically safe.

  8. Simulation of the irradiation behaviour of the PBMR fuel in the SAFARI-1 reactor / B.M. Makgopa

    OpenAIRE

    2009-01-01

    Irradiation experiments for the pebble bed modular reactor PBMR fuel (coated fuel particles and pebble fuel) are planned at the South African First Atomic Reactor Installation (SAFARI-1). The experiments are conducted to investigate the behavior of the fuel under normal operating and accelerated/accident simulating conditions because the safe operation of the reactor relies on the integrity of the fuel for retention of radioactivity. For fuel irradiation experiments, the accura...

  9. DESAIN TERAS DAN BAHAN BAKAR PLTN JENIS PEBBLE BED MODULAR REACTOR (PBMR DENGAN MENGGUNAKAN PROGRAM SRAC

    Directory of Open Access Journals (Sweden)

    Sungkowo Wahyu Santoso

    2015-03-01

    entered to criticality core and safety aspects of nuclear reactor with the parameters are multiplication factor (keff and fuel temperature coefficient, moderator temperature coefficient and coolant temperature coefficient. Core PBMR-HTR finite cylindrical with a hole in the middle which contains 334,000 pebble fuel bed. That consist of UO2 fuel, graphite moderator and helium coolant. Down scale the design model performed on the half core represent the whole core. The study was conducted by varying the fuel enrichment of 8%; 8.5%; 9%; 9.5% and 10%, while variation burnable poison enrichment at 5 ppm, 7 ppm, 9 ppm, 11 ppm and 15 ppm. The variation of coolant flow rate of 60%, 80%, 100%, 120% and 140% from its original value at 17.118 kg/s while the variation of coolant temperature input at 673.15 K; 723.15 K; 773.15 K; 823.15 K and 873.15 K. In this research, value of keff without Gd2O3 are 1.026213 (BOL and 1.004173 (EOL with excess reactivity of 2.55% with 9% U235 enrichment. While keff on BOL by using 7 ppm Gd2O3 of 1.006968 and 1.004198 for EOL with excess reactivity of 0.69%. Fuel temperature reactivity coefficient, moderator and coolant in a row for -8.597317E-05/K; -2.595284E-05 /K and 1.1496E-06/K. Temperature reactivity coefficient is negative. This indicates inherent safety characteristic have been met. Increasing the input temperature and coolant flow rate reduction lowers the value of keff core, and it will contribute to negative reactivity coefficient. Keywords : PBMR-HTR, criticality, reactivity, down scale, burnable poison

  10. The Thermal-Hydraulic model for the pebble bed modular reactor (PBMR) plant operator training simulator system

    Energy Technology Data Exchange (ETDEWEB)

    Dudley, Trevor [Pebble Bed Modular Reactor (Proprietary) Limited, Die Anker Building, Centurion 0046 (South Africa)], E-mail: trevor.dudley@pbmr.co.za; Bouwer, Werner; Villiers, Piet de [Pebble Bed Modular Reactor (Proprietary) Limited, Die Anker Building, Centurion 0046 (South Africa); Wang Zen [GSE Systems, Inc., 7133 Rutherford Suite 200, Baltimore, MD 21244 (United States)

    2008-11-15

    This paper provides a discussion of the model development status and verification efforts for the Reactor Core Thermal-Hydraulic model developed for the full-scope plant Operator Training Simulator System of the Pebble Bed Modular Reactor (PBMR). Due to the First of a Kind Engineering nature and lack of reference plant data, model verification has mainly been focused on benchmarking the model configurations against test cases performed by PBMR design analysis codes, i.e. TINTE, VSOP and FLOWNEX. As a first step, due to the symmetrical physical nature of the PBMR core, a two-dimensional (2D) model configuration in radial and axial directions (axial-symmetry) was developed. The design was subsequently extended to a three-dimensional (3D) configuration. Through the use of cross-flow and cross-conduction links, three nearly identical 2D configurations were glued together to form this 3D model configuration. To date, the 3D configuration represents the most comprehensive model to simulate the PBMR core thermo-hydraulics. This paper concludes with the verification of thermodynamic and heat-transfer properties of two steady state (100% and 40% power) conditions between the 3D Reactor Core Thermal-Hydraulic model and the available FLOWNEX and TINTE design code analysis. The transient operations between these two power levels are also discussed.

  11. Characteristics of a different fuel cycle in a PBMR-400 for burning reactor grade plutonium

    Energy Technology Data Exchange (ETDEWEB)

    Mulder, Eben [M-TECH Industrial (Pty) Ltd., PO Box 54620, Wierdapark 0149 (South Africa)], E-mail: ejm@mtechindustrial.com; Teuchert, Eberhard [M-TECH Industrial (Pty) Ltd., PO Box 54620, Wierdapark 0149 (South Africa)

    2008-11-15

    An outstanding feature of the high temperature, gas-cooled, version of a Generation IV type reactor is its versatility in application. Apart from the capacity in high temperature gas-cooled reactors to generate electricity it could desalinate (multi-effect distillation [MED] by deploying excess heat or reverse osmosis by deploying excess electricity), produce hydrogen (by deploying excess electricity), whereas this article showcases the on-line fuelling characteristics of a pebble bed reactor concept for the incineration of reactor grade plutonium, whilst producing electricity. The VSOP-A system of codes is employed to demonstrate by calculation how the standard PBMR-400 commercial reactor design offers similar inherent safety characteristics with a Pu-Th/U advanced fuel cycle. This implies that no significant design changes are necessary to implement such a fuel cycle. Furthermore, the flexibility of the pebble fuel concept is deployed to house the fertile material in one type of pebble, whilst a second type will contain the fissile or driver material.

  12. Supplemental Report on Nuclear Safeguards Considerations for the Pebble Bed Modular Reactor (PBMR)

    Energy Technology Data Exchange (ETDEWEB)

    Moses, David Lewis [ORNL; Ehinger, Michael H [ORNL

    2010-05-01

    Recent reports by Department of Energy National Laboratories have discussed safeguards considerations for the low enriched uranium (LEU) fueled Pebble Bed Modular Reactor (PBMR) and the need for bulk accountancy of the plutonium in used fuel. These reports fail to account effectively for the degree of plutonium dilution in the graphitized-carbon pebbles that is sufficient to meet the International Atomic Energy Agency's (IAEA's) 'provisional' guidelines for termination of safeguards on 'measured discards.' The thrust of this finding is not to terminate safeguards but to limit the need for specific accountancy of plutonium in stored used fuel. While the residual uranium in the used fuel may not be judged sufficiently diluted to meet the IAEA provisional guidelines for termination of safeguards, the estimated quantities of {sup 232}U and {sup 236}U in the used fuel at the target burn-up of {approx}91 GWD/MT exceed specification limits for reprocessed uranium (ASTM C787) and will require extensive blending with either natural uranium or uranium enrichment tails to dilute the {sup 236}U content to fall within specification thus making the PBMR used fuel less desirable for commercial reprocessing and reuse than that from light water reactors. Also the PBMR specific activity of reprocessed uranium isotopic mixture and its A{sub 2} values for effective dose limit if released in a dispersible form during a transportation accident are more limiting than the equivalent values for light water reactor spent fuel at 55 GWD/MT without accounting for the presence of the principal carry-over fission product ({sup 99}Tc) and any possible plutonium contamination that may be present from attempted covert reprocessing. Thus, the potentially recoverable uranium from PBMR used fuel carries reactivity penalties and radiological penalties likely greater than those for reprocessed uranium from light water reactors. These factors impact the economics of

  13. Optimisation of deep burn incineration of reactor waste plutonium in a PBMR DPP-400 core

    Energy Technology Data Exchange (ETDEWEB)

    Serfontein, Dawid E., E-mail: Dawid.Serfontein@nwu.ac.za [School for Mechanical and Nuclear Engineering, North West University, PUK-Campus, Private Bag X6001, Internal Post Box 360, Potchefstroom 2520 (South Africa); Mulder, Eben J. [School for Mechanical and Nuclear Engineering, North West University (South Africa); Reitsma, Frederik [Calvera Consultants (South Africa)

    2014-05-01

    In this article an original set of coupled neutronics and thermo-hydraulic simulation results for the VSOP 99/05 diffusion code are presented for advanced fuel cycles for the incineration of weapons-grade plutonium, reactor-grade plutonium and reactor-grade plutonium with its associated Minor Actinides in the 400 MW{sub th} Pebble Bed Modular Reactor Demonstration Power Plant. These results are also compared to those of the standard 9.6 wt% enriched 9 g/fuel sphere U/Pu fuel cycle. The weapons-grade and reactor-grade plutonium fuel cycles produced good burn-ups. However, the addition of the Minor Actinides to the reactor-grade plutonium caused a large decrease in the burn-up and thus an unacceptable increase in the heavy metal (HM) content in the spent fuel, which was intended for direct disposal in a deep geological repository, without chemical reprocessing. All the plutonium fuel cycles failed the adopted safety limits used in the PBMR400 in that either the maximum fuel temperature of 1130 °C during normal operation, or the maximum power density of 4.5 kW/sphere was exceeded. All the plutonium fuel cycles also produced positive uniform temperature reactivity coefficients, i.e. the reactivity coefficient where the temperatures of the fuel and the graphite moderator in the fuel spheres were varied together. These unacceptable positive coefficients were experienced at low temperatures, typically below 700 °C. This was due to the influence of the thermal fission cross-section resonances of {sup 239}Pu and {sup 241}Pu. Weapons-grade plutonium produced the worst safety performance. The safety performance of the reactor-grade plutonium also deteriorated when the HM loading was reduced from 3 g/sphere to 2 g or 1 g.

  14. Experimental investigation of pebble flow dynamics using radioactive particle tracking technique in a scaled-down Pebble Bed Modular Reactor (PBMR)

    Energy Technology Data Exchange (ETDEWEB)

    Khane, Vaibhav; Said, I.A.; Al-Dahhan, Muthanna H., E-mail: aldahhanm@mst.edu

    2016-06-15

    Highlights: • Pebble Flow fields at Pebble Bed Modular Reactor was investigated. • Radioactive Particle Tracking (RPT) technique has been used. • Plug flow type velocity profile is suggested at upper cylindrical region. - Abstract: The Pebble Bed Modular Reactor (PBMR) is a type of very-high-temperature reactor (VHTR) that is conceptually very similar to moving bed reactors used in the chemical and petrochemical industries. In a PBMR core, nuclear fuel is in the form of pebbles and moves slowly under the influence of gravity. In this work, an integrated experimental and computational study of granular flow in a scaled-down cold flow PBMR was performed. A continuous pebble re-circulation experimental set-up, mimicking the flow of pebbles in a PBMR was designed and developed. An experimental investigation of pebble flow dynamics in a scaled down test reactor was carried out using a non-invasive radioactive particle tracking (RPT) technique that used a cobalt-60 based tracer to mimic pebbles in terms of shape, size and density. A cross-correlation based position reconstruction algorithm and RPT calibration data were used to obtain results about Lagrangian trajectories, the velocity field, and residence time distributions. The RPT technique results a serve as a benchmark data for assessing contact force models used in the discrete element method (DEM) simulations.

  15. Development of a neutronic model for the fuel of a high temperature gas reactor type PBMR; Desarrollo de un modelo neutronico para el combustible de un reactor de gas de alta temperatura tipo PBMR

    Energy Technology Data Exchange (ETDEWEB)

    Oropeza C, I.; Carmona H, R.; Francois L, J. L. [UNAM, Facultad de Ingenieria, Departamento de Sistemas Energeticos, Paseo Cuauhnahuac 8532, Jiutepec, Morelos 62550 (Mexico)]. e-mail: ivonucci@prodigy.net.mx

    2008-07-01

    In this work was developed the neutronic model of a fuel sphere of a nuclear reactor of gas of high temperature to modulate of bed of spheres (PBMR), using the Monte Carlo method with the MCNPx code. In order to be able to verify the fuel model constructed in this investigation, it is used a case of reference, based on an international exercise {sup b}enchmark{sup .} The benchmark report contains the results sent by different international participants for five phases with respect to the high temperature gas reactor (HTR), fed with uranium, plutonium and thorium. In particular, in first stage of benchmark an infinite adjustment of uranium compound fuel spheres is considered unique, with which our results were compared. This first stage considers two cases: cell calculations with spherical external frontier and cell calculations with cubic external frontier. The objective is to identify any increase in the uncertainty, related to the uranium fuel, that is associated with the plutonium and thorium fuels. In order to validate our results, the values of the neutron multiplication factor were taken in account, in cold and in the heat of the moment from the participants who sent their results obtained with Monte Carlo and deterministic calculations. The model of the fuel sphere developed in this work considers a regular distribution of 15000 Triso particles, in a cubic mesh centered within the sphere. For it was necessary to define the step firstly or {sup p}itch{sup o}f the cubic mesh. Generally, the results obtained by the participants of benchmark and those of this investigation present good agreement, nevertheless, appear some discrepancies, attributed to factors like different libraries of cross sections used, the nature of the solution: Monte Carlo or deterministic, and the difficulty of some participants to model the external frontier condition of reflection. (Author)

  16. Container concept for the PBMR fuel plant

    Energy Technology Data Exchange (ETDEWEB)

    Braehler, G.; Kelly, M.; Sauer, L.; Welbers, P. [NUKEM Technologies GmbH (Germany)

    2009-07-01

    This presentation describes the types and the characteristics of the containers uniquely designed for and used in the PBMR Fuel Plant in Pelindaba, South Africa. The PBMR Fuel Plant is designed to manufacture so called Fuel Spheres for the High Temperature Reactor which shall be built in Koeberg near Cape Town. The PBMR fuel is based on a proven, high quality German fuel design consisting of 10% enriched Uranium triple-coated isotropic (LEU-TRISO) particles contained in a moulded graphite sphere. A coated particle comprises a kernel of Uranium dioxide surrounded by different layers. A fuel sphere consists of 9 g of Uranium (some 15 000 particles) and has a diameter of 60 mm; the total mass of a fuel sphere is 210 g. During normal operation the PBMR core contains a load of 456,000 fuel spheres. The PBMR Fuel plant is designed to produce 270,000 fuel spheres a year with the option to doubling the throughput. Two basic types of containers are foreseen for the plant, i.e. the Safe Geometry Containers for transportation and storage of Uranium bearing material and Containers in non restricted geometry for solid raw and auxiliary materials required by the different processes. Unlike other concepts in fuel element plants, the Safe Geometry Containers are allowed to be stored, from a criticality point of view, everywhere in the plant. Special identification measures, physical and IT based, prevent wrong material being processed. The sub-critical configuration is still maintained after the specified fire scenario for the PBMR Fuel Plant. (orig.)

  17. Validation of the point kinetic neutronic model of the PBMR / Deon Marais

    OpenAIRE

    Marais, Deon

    2007-01-01

    This study introduces a new method for the validation of the point kinetic neutronic model of the PBMR. In this study the diffusion equation solution, as implemented in the TlNTE PBMR 268 MW reactor model, replaces the point kinetic model, as implemented in the Flownex V502 PBMR plant model. An indirect coupling method is devised and implemented in an external program called Flownex-Tinte-Interface (FTI) to facilitate the data exchange between these two codes. The validation...

  18. Application of MCBEND to PBMR shielding analysis.

    Science.gov (United States)

    Wright, G A; Wall, S J

    2005-01-01

    Shielding analysis of an early design of Pebble Bed Modular Reactor (PBMR) has been carried out by using the Monte Carlo code MCBEND. The issues of concern were damage to the core barrel and the reactor pressure vessel (RPV), activation of the core barrel, RPV, top plate and bottom plate, and also burn-up of boron in the control layer underneath the core. The analysis below the core was complicated due to the presence of the de-fuelling chute, which meant that multiplication had to be taken into account. The analysis of boron burn-up was particularly challenging and was tackled using a combination of MCBEND and the criticality code MONK in the depletion mode. The application of MCBEND to the shielding analysis of the PBMR is described, with particular attention being paid to the regions below the core.

  19. The PBMR electric power generation plant; La planta de generacion de energia electrica PBMR

    Energy Technology Data Exchange (ETDEWEB)

    Perez S, G.; Santacruz I, I.; Martin del Campo M, C. [FI-UNAM, 04500 Mexico D.F. (Mexico)] e-mail: gabriela_perez@engineer.com

    2003-07-01

    This work has as purpose to diffuse in a general way the technology of the one modulate reactor of pebble bed. Because our country is in developing ways, the electric power demand goes in increase with that which it is presented the great challenge of satisfying this necessity, not only being in charge of the one fact per se, but also involving the environmental aspect and of security. Both factors are covered by the PBMR technology, which we approach in their basic aspects with the purpose that the public opinion knows it and was familiarized with this type of reactors that well could represent a solution for our growing electricity demand. We will treat this reactor visualizing it like part of a generation plant defining in first place to the itself reactor. We will see because that the system PBMR consists of 2 main sections: the reactor and the unit of energy conversion, highlighting that the principle of the PBMR reactor operation is based on the thermodynamic Brayton cycle cooled by helium and that, in turn, it transmits the energy in form of heat toward a gas turbine. In what concerns to the fuel, it peculiar design due to its spherical geometry is described, aspect that make to this reactor different from the traditional ones that use fuel rods. In fact in the fuel spheres of the PBMR it is where it resides great part of it inherent security since each particle of fuel, consistent in uranium dioxide, is lined one with coal and silicon carbide those which form an impenetrable barrier containing to the fuel and those radioactive products that result of the nuclear reactions. Such particles are encapsulated in graphite to form the sphere or 'pebble', of here born the name of this innovative technology. (Author)

  20. Fission product transport during pipebreaks in a PBMR confinement / Mathhew Sanyasi

    OpenAIRE

    Sanyasi, Mathhew

    2010-01-01

    The Pebble Bed Modular Reactor (PBMR) (Pty) Ltd Company intends to develop a demonstration power plant to be operated by the South African state owned utility Eskom. This demonstration plant will be a high temperature gas cooled reactor (HTGR) that will be graphite moderated and helium cooled. In the event of a pipe break within the helium pressure boundary (HPB) of a PBMR module, the circulating helium coolant is released into the confinement building and if the resulting pres...

  1. Neutronic characteristics of an OTTO refueling PBMR

    Energy Technology Data Exchange (ETDEWEB)

    Tran, Hoai Nam, E-mail: nam@nephy.chalmers.se [Chalmers University of Technology, Department of Applied Physics, Division of Nuclear Engineering, SE-412 96 Gothenburg (Sweden); Hoang, Van Khanh [Institute for Nuclear Science and Technology, 179 Hoang Quoc Viet str., Hanoi (Viet Nam)

    2012-12-15

    Highlights: Black-Right-Pointing-Pointer Neutronic characteristics were analyzed for an OTTO refueling PBMR. Black-Right-Pointing-Pointer The core uses newly designed fuel pebbles with Gd{sub 2}O{sub 3} as burnable poison. Black-Right-Pointing-Pointer The neutronic characteristics are comparable with a reference multi-pass scheme. Black-Right-Pointing-Pointer The average discharged burnup is 21% lower than that of the multi-pass scheme. - Abstract: Neutronic characteristics were investigated for a once-through-then-out (OTTO) refueling scheme based on the 400 MWt pebble bed modular reactor (PBMR) and compared with that of a reference multi-pass scheme. The core was loaded with new fuel pebbles which were designed with Gd{sub 2}O{sub 3} particles to flatten the axial power profile. The Gd{sub 2}O{sub 3} design was considered in a multi-parameter optimization to maximize the average discharged burnup while maintaining a limited power peak and ensuring core criticality. The results show that the OTTO scheme using the new fuel pebbles can achieve the maximum average discharged burnup of about 75 GWd/t, at which the core neutronic characteristics are comparable with that of the reference multi-pass scheme. This means that the efficiency of fuel utilization of the OTTO scheme is about 21% less than that of the multi-pass scheme (95 GWd/t).

  2. Method for the thermo-hydraulic analysis of the test facility for the PBMR reserve shutdown system / Petrus Gerhardus van der Merwe

    OpenAIRE

    2004-01-01

    The Pebble Bed Modular Reactor (PBMR) is a revolutionary small, compact and safe nuclear power plant. It operates on a direct closed Brayton cycle. One of the unique features of this concept is its load following capability enabled by extracting or injecting of the working fluid (in the PBMR's case Helium) from or to the system during operation. The Reserve Shutdown System (RSS) is one of the essential subsystems of the PBMR. The RSS is used as a maintenance and secondary shutd...

  3. Support to design and construction of the PBMR plant; Apoyo al diseno y construccion de la planta piloto PBMR

    Energy Technology Data Exchange (ETDEWEB)

    Cazorla, F.; Moron, P.; Gonzalez, J. I.

    2010-07-01

    Developing the new reactor design to a licensable state for constructing a pilot plant is a tough task require specific resources, concerning knowledge and previous experience, which trespassing the pure scientific or technologic knowledge linked to the reactor conceptual design. Taking into consideration the experience derived from the collaboration between the South African company PBMR (PTY) Ltd.; the Pebble Bed Modular Reactor Designer, and Tecnatom SA, the article presents some of the aspects in which the companies or organization in charge of the design can demand external support to license and construct the pilot plants with guaranteed success. (Author)

  4. PBMR fuel sphere production facility project Pelindaba, South Africa

    Energy Technology Data Exchange (ETDEWEB)

    Braehler, G.; Buettner, K.; Froschauer, K.; Kress, W. [NUKEM GmbH, Alzenau (Germany)

    2006-11-15

    Due to the dramatically continuous increasing world wide demand on energy and the efforts in reducing CO{sub 2} emissions nuclear power is again being taken more and more under serious consideration. Here the HTR technology is especially considered due to its unique safety features, based on the modular design and the relatively small reactor core. The high temperature level opens the opportunity to produce hydrogen and to substitute fossil fuels for process heat generation. The development of the modular HTR technology in Germany started in the late 1970ies. Besides the modular reactor design and the small dimensioned reactor core design itself, the major safety features of the HTR technology are based on the fuel element as such. The development of the HTR fuel element in Germany has been systematically performed by NUKEM. Nowadays this technology is again being specially considered and new activities are being undertaken in the further development of this technology in numerous countries, especially in the PBMR project in South Africa. The first criticality of the South African pebble bed modular reactor is planned for 2013. In order to achieve this milestone the following time schedule for the pilot fuel plant in Pelindaba has been established. NUKEM has been involved in the PBMR PFP project form the very beginning. (orig.)

  5. Separate effects tests to determine the effective thermal conductivityin the PBMR HTTU test facility

    OpenAIRE

    2014-01-01

    Thermal-fluid simulations are used extensively to predict the maximum fuel temperatures, flows, pressure drops and thermal capacitance of pebble bed gas cooled reactors in support of the reactor safety case. The PBMR company developed the HTTU non-nuclear test facility in cooperation with M-Tech Industrial (Pty) Ltd. and the North-West University in South Africa to conduct comprehensive separate effects tests as well as integrated effects tests to study the different thermal-fluid phenomena. ...

  6. Verification of Serpent code for the fuel analysis of a PBMR; Verificacion del codigo SERPENT para el analisis de combustible para un PBMR

    Energy Technology Data Exchange (ETDEWEB)

    Bastida O, G. E.; Francois L, J. L., E-mail: gbo729@yahoo.com.mx [UNAM, Facultad de Ingenieria, Departamento de Sistemas Energeticos, Ciudad Universitaria, 04510 Ciudad de Mexico (Mexico)

    2015-09-15

    In this paper the models and simulations with the Monte Carlo code Serpent are presented, as well as the obtained results of the different analyzed cases in order to verify the suitability or reliability of the use of this code to ensure favorable results in the realization of a neutronic analysis of fuel for a Pebble Bed Modular Reactor (PBMR). Comparisons were made with the results reported in a report by the OECD/Nea relative to a high temperature reactor of spheres bed with plutonium reactor grade as fuel. The results show that the use of Serpent is appropriate, as these results are comparable with those reported in the report. (Author)

  7. Preliminary safety analysis of a PBMR supplying process heat to a co-located ethylene production plant

    Energy Technology Data Exchange (ETDEWEB)

    Scarlat, Raluca O., E-mail: rscarlat@nuc.berkeley.edu [University of California Berkeley, Nuclear Engineering, 4118 Etcheverry Hall, Berkeley, CA 94720 (United States); Cisneros, Anselmo T. [University of California Berkeley, Nuclear Engineering, 4118 Etcheverry Hall, Berkeley, CA 94720 (United States); Koutchesfahani, Tawni [University of California, Chemical and Biomolecular Engineering, 201 Gilman Hall, Berkeley, CA 94720 (United States); Hong, Rada; Peterson, Per F. [University of California Berkeley, Nuclear Engineering, 4118 Etcheverry Hall, Berkeley, CA 94720 (United States)

    2012-10-15

    This paper considers the safety analysis and licensing approach for co-locating a pebble bed modular reactor (PBMR) to provide process heat to an ethylene production unit. The PBMR is an advanced nuclear reactor design that provides 400 MW of thermal energy. Ethylene production is an energy intensive process that utilizes large gas furnaces to provide the heat for the process. Coupling a PBMR with an ethylene production plant would open a new market for nuclear power, and would provide the chemical industry with a cleaner power source, helping to achieve the Clean Air Act standards, and eliminating the 0.5 ton of CO{sub 2} emissions per ton of produced ethylene. Our analysis uses the Chevron Phillips chemical plant in Sweeney, TX as a prototypical site. The plant has four ethylene production trains, with a total power consumption of 2.4 GW, for an ethylene output of 3.7 million tons per year, 4% of the global ethylene production capacity. This paper proposes replacement of the gas furnaces by low-emission PBMR modules, and presents the safety concerns and risk mitigation and management options for this coupled system. Two coupling design options are proposed, and the necessary changes to the design basis events and severe accidents for the PBMR licensing application are discussed. A joint effort between the chemical and the nuclear entities to optimize the coupling design, establish preventive maintenance procedures, and develop emergency response plans for both of the units is recommended.

  8. Design Optimization of Inlet Plenum of PBMR Using Kriging Modeling Technique

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kwang Yong; Lee, Sang Moon [Mechanical Engineering Department, INHA Univ, Incheon (Korea, Republic of)

    2009-05-15

    In pebble-bed modular reactor (PBMR), the combination of coated particle fuel, inert helium gas as coolant and graphite moderated reactor makes it possible to operate at high temperature yielding a high efficiency. In cooling system of PBMR, Helium gas as the coolant enters the reactor through inlet plenum, i.e., ring channel at the bottom of the reactor, goes up through several rising channels to upper plenum, enters the core at a temperature of about 540 .deg. C and at a pressure of about 7 MPa, and then leaves the reactor through lower plenum at a temperature of about 900 .deg. C under normal operating conditions. Ahmad et al. performed a parametric study on inlet plenum geometry of PBMR with Reynolds-averaged Navier-Stokes (RANS) analysis, and suggested that the flow uniformity in rising channels as well as the pressure drop is found to increase as the channel diameter is decreased. The flow distribution in the rising channels is independent of Reynolds number. Increase in the angle between the inlet ports and aspect ratio is found to increase the uniformity in flow distribution. However, there has not been a trial to introduce systematic optimization techniques in the design of cooling passages of HTGR to find the geometry which maximizes the performance. In this work, shape optimization of inlet plenum and rising channels in PBMR has been performed based on three-dimensional RANS analysis. Kriging model is used as a surrogate model for optimization. The objectives of the design are to maximize the uniformity in the flow distribution in rising channels and to minimize the pressure drop.

  9. Design criteria of integrated reactors based on transients; Criterios de diseno de reactores integrados basados en transitorios

    Energy Technology Data Exchange (ETDEWEB)

    Zanocco, P.; Gimenez, M.; Delmastro, D. [Comision Nacional de Energia Atomica, San Carlos de Bariloche (Argentina). Centro Atomico Bariloche

    1999-11-01

    A new tendency in integrated reactors conceptual design is to include safety criteria through accident analysis. In this work, the effect of design parameters in a Loss of Heat Sink transient using design maps is analyzed. Particularly, geometry related parameters and reactivity coefficients are studied. Also the effect of primary relief/safety valve during the transient is evaluated. A design map for valve area vs. coolant density reactivity coefficient is obtained. A computer code (HUARPE) is developed in order to simulate these transients. Coolant, steam dome, pressure vessel structures and core models are implemented. This code is checked against TRAC with satisfactory results. (author) 5 refs., 13 figs.

  10. STUDI MODEL ALIRAN FLUIDA DAN PERPINDAHAN PANAS PADA PBMR.

    Directory of Open Access Journals (Sweden)

    Achmad Fatich Al-Qodri

    2013-11-01

    Full Text Available Reaktor tipe Pebble bed merupakan opsi yang menjanjikan untuk teknologi reaktor generasi mendatang dan memiliki potensi untuk memberikan pembangkitan listrik dengan efisiensi tinggi dan murah.Perpindahan panas reaktor ini menghadapi kendala akibat kompleksitas yang berkaitan dengan desain aliran panas.Dengan demikian, untuk mensimulasikan secara baik aliran dan perpindahan panas reaktor modular pebble bed ini memerlukan suatu model perpindahan panas yang berhubungan dengan radiasi serta konveksi dan konduksi panas.Dalam studi ini, suatu model dengan kemampuan untuk mensimulasikan aliran fluida dan perpindahan panas dalam teras reaktor modular pebble bed telah dikembangkan.Model ini diterapkan pada suatu personal computer (PC yang menggunakan program komputer Matlab r2008a Versi 7.1.Beberapa parameter penting aliran fluida dan perpindahan panas telah dipelajari, termasuk penurunan tekanan (pressure drop di teras reaktor, koefisien perpindahan panas, bilangan Nusselt, dan konduktivitas panas efektif pebble bahan bakar. Hasil yang diperoleh dari percobaan simulasi menunjukkan adanya suatu tekanan yang merata pada arah radial untuk suatu rasio diameter teras terhadap elemen bakar (D/d > 20 dan koefisien perpindahan panas meningkat seiring dengan peningkatan temperatur dan laju alir massa pendingin. Model ini dapat menjelaskan secara memadai fenomena aliran panas dan perpindahan panas dan kehilangan tekanan melalui friksi dalam PBMR tipe pebble bed.Kata kunci: Aliran fluida, perpindahan panas, PBMR, packed bed, penurunan tekananAbstractThe pebble bed type high temperature gas cooled nuclear reactor is a promising option for next generation reactor technology and has the potential to provide high efficiency and cost effective electricity generation. The reactor unit heat transfer poses a challenge due to the complexity associated with the thermalflow design. Therefore to reliably simulate the flow and heat transport of the pebble bed modular reactor

  11. A study on the design concepts of the PBMR and the GT-MHR

    Energy Technology Data Exchange (ETDEWEB)

    Park, Won Seok; Chang, Jong Hwa; Park, Chang Kue

    2004-05-01

    The major application of the nuclear power in the energy sector has been to produce the electricity. However, a growing concern on the environment and the expected shortage of the fossil energy resources is demanding the expansion of nuclear energy's role in the energy sectors. The High Temperature Gas cooled Reactor (HTGR) has been expected to expand the role of nuclear energy because of its high temperature capability. Especially, the interest on the HTGR has been sharply increased recently related with the production of the hydrogen. About 5 HTGRs had been operated by the end of 1980s. However, all of them had been terminated permanently at the end of 1980s because of their poor system economy and frequent technical troubles. A new concept called MHTGR (Modular High Temperature Gas cooled Reactor) emerged in early of 1990s. Two MHTGR concepts on commercial basis have been developed since then; one is the PBMR (Pebble Bed Modular Reactor) developed by Eskom in South Africa and another is GT-MHR (Gas Turbine Modular High-temperature Reactor) developed by both GA in USA and OKBM in Russia. In this report, the design concepts for the PBMR and GT-MHR were reviewed.

  12. Development of a novel nitriding plant for the pressure vessel of the PBMR core unloading device / Ryno Willem Nell.

    OpenAIRE

    Nell, Ryno Willem

    2010-01-01

    The Pebble Bed Modular Reactor (PBMR) is one of the most technologically advanced developments in South Africa. In order to build a commercially viable demonstration power plant, all the specifically and uniquely designed equipment must first be qualified. All the prototype equipment is tested at the Helium Test Facility (HTF) at Pelindaba. One of the largest components that are tested is the Core Unloading Device (CUD). The main function of the CUD is to unload fuel from the bottom of the...

  13. PBMR radionuclide source term analysis validation based on AVR operating experience

    Energy Technology Data Exchange (ETDEWEB)

    Stoker, C.C. [PBMR, Lake Buena Vista Building, 1267 Gordon Hood Avenue, Centurion 0046 (South Africa); Olivier, L.D. [Independent Nuclear Consultants, Grahamstown (South Africa); Stassen, E.; Reitsma, F. [PBMR, Lake Buena Vista Building, 1267 Gordon Hood Avenue, Centurion 0046 (South Africa); Merwe, J.J. van der, E-mail: hanno.vdmerwe@pbmr.co.z [PBMR, Lake Buena Vista Building, 1267 Gordon Hood Avenue, Centurion 0046 (South Africa)

    2010-10-15

    The determination of radionuclide source terms is vital for any reactor design and licensing safety evaluation. This paper provides an overview of the PBMR analysis tools with specific focus on the modelling of mobile and deposited radionuclide source terms within the pressure boundary of a typical pebble-bed high temperature reactor (HTR). The main focus is on the Dust and Activity Migration and Distribution (DAMD) software code system that models the activation, migration and time-dependent distribution of dust and atomic particles in an HTR such as the AVR and PBMR. Since DAMD provides a time-dependent systems integrated model of HTR designs, most of the obvious physical phenomena relevant to source terms are at play. These include the neutron flux, activation cross-sections, radioactive decay, dust production rates, dust impurity levels, dust filter capabilities, dust particle size distributions, thermal-hydraulic parameters influencing the migration and distribution of particles throughout the main power system and subsystems, and helium coolant leakage and make-up rates. At this stage the DAMD calibration and validation is mainly based on the operational data, experiments and measurements made during 21 years of operating life of the AVR. The comparisons of the DAMD results with various AVR measurements provide confidence in the use of DAMD for the PBMR design and safety evaluations. In addition, sensitivity analyses are performed with DAMD to determine the bounding system parameters that drive the migration and distribution of radionuclides. The use of DAMD to evaluate design configurations, e.g. the effect of the introduction and placement of filters on the radionuclide distribution, is also shown. In conclusion, the importance of a systems modelling approach for radionuclide transport and distribution within the pressure boundary of a typical HTR system, is demonstrated. Since the DAMD code system is calibrated and validated against the AVR measurements it

  14. Separate effects tests to determine the effective thermal conductivity in the PBMR HTTU test facility

    Energy Technology Data Exchange (ETDEWEB)

    Rousseau, P.G., E-mail: pgr@mtechindustrial.com [School of Mechanical and Nuclear Engineering, North-West University, Private Bag X6001, Potchefstroom 2520 (South Africa); Toit, C.G. du; Antwerpen, W. van [School of Mechanical and Nuclear Engineering, North-West University, Private Bag X6001, Potchefstroom 2520 (South Africa); Antwerpen, H.J. van [M-Tech Industrial (Pty) Ltd., PO Box 19855, Noordbrug 2522 (South Africa)

    2014-05-01

    Thermal-fluid simulations are used extensively to predict the maximum fuel temperatures, flows, pressure drops and thermal capacitance of pebble bed gas cooled reactors in support of the reactor safety case. The PBMR company developed the HTTU non-nuclear test facility in cooperation with M-Tech Industrial (Pty) Ltd. and the North-West University in South Africa to conduct comprehensive separate effects tests as well as integrated effects tests to study the different thermal-fluid phenomena. This paper describes the separate effects tests that were conducted to determine the effective thermal conductivity through the pebble bed under near-vacuum conditions and temperatures up to 1200 °C. It also presents the measured temperature distributions and the methodology applied in the data analysis to derive the resultant values of effective thermal conductivity and its associated uncertainty.

  15. Evaluation of the Strategic Value of Fully Burnt PBMR Spent Fuel - A Report to ISPO in Response to IAEA Letter Request (2004-08-30)

    Energy Technology Data Exchange (ETDEWEB)

    A. M. Ougouag; H. D. Gougar; T. A. Todd

    2006-05-01

    The IAEA needs to determine the value of imposing safeguards on the spent fuel storage at the Pebble Bed Modular Reactor (PBMR) planned for construction in the Republic of South Africa. The PBMR will use hundreds of thousands of fuel elements in the shape of small spheres (6 cm in diameter). The PBMR plant design calls for the storage on site of all the spent fuel generated during the whole life of the reactor, expected to span 40 years. The spent fuel storage system is designed (or to be designed) for a functional life of 80 years. If it is determined that the spent fuel contains materials of interest to a would-be proliferant, then safeguards would have to be imposed and maintained until the spent fuel elements are processed into a form and composition that no longer requires safeguards. The problem addressed in this report is the determination of the strategic value of the spent fuel to such a would-be proliferant.

  16. Separate effects tests to determine the thermal dispersion in structured pebble beds in the PBMR HPTU test facility

    Energy Technology Data Exchange (ETDEWEB)

    Toit, C.G. du, E-mail: jat.dutoit@nwu.ac.za; Rousseau, P.G.; Kgame, T.L.

    2014-05-01

    Thermal-fluid simulations are used extensively to predict the maximum fuel temperatures, flows, pressure drops and thermal capacitance of pebble bed gas cooled reactors in support of the reactor safety case. The PBMR company developed the HTTF test facility in cooperation with M-Tech Industrial (Pty) Ltd. and the North-West University in South Africa to conduct comprehensive separate effects tests as well as integrated effects tests to study the different thermal-fluid phenomena. This paper describes the separate effects tests that were conducted to determine the effect of the porous structure on the fluid effective thermal conductivity due to the thermal dispersion. It also presents the methodology applied in the data analysis to derive the resultant values of the effective thermal conductivity and its associated uncertainty.

  17. Design and simulation of a process of seawater desalination (MED) using the residual heat of a PBMR nuclear power plant; Diseno y simulacion de un proceso de desalinizacion de agua de mar (MED) utilizando el calor residual de una planta nucleoelectrica PBMR

    Energy Technology Data Exchange (ETDEWEB)

    Valle H, Julio; Morales S, J.B. [UNAM, DEPFI Campus Morelos, Jiutepec, Morelos (Mexico)]. e-mail: jms0620@yahoo.com

    2008-07-01

    In the present work it is demonstrated as the thermodynamic recuperative Brayton cycle with which operates a nuclear power plant type PBMR (Pebble Bed Modular Reactor) it allows to use the residual heat, removed in the coolers of the compression stage of the system, to produce vapor and to desalt seawater. The desalination process selected, starting from its operation characteristics and the derived advantages of them using nuclear heat, it the one of Multi-Effect Distillation, MED for its abbreviations in English, which described and it is justified to detail. This distillation process widely studied, allows us to use water vapor pressurized to temperatures between 70 and 110 C like energy source to evaporate the seawater in the first stage or effect of the process. The relatively low temperatures with which the vapor takes place of feeding to the process is it makes to the plant PBMR ideal for desalination of seawater, since does not require majors modifications to its design its operation, and on the contrary it allows to use the heat that previously was rejected, to produce the vapor. In this work an unit MED of six effects is designed, which undergoes a successive fall of pressure in each of them. Once obtained the agreed design to the conditions of operation of PBMR plant, it was model mathematically the MED process, including the coupling stage with the reactor coolers. The mathematical model was obtained by means of differential equations of mass balance and energy in the system, and with this it was implemented in SIMULINK a model equivalent to the MED process which is interconnected to the simulator coolers of the PBMR plant, constructed previously. One ran the program being obtained the results that are reported at the end of this article. (Author)

  18. Pebble bed modular reactor safeguards: developing new approaches and implementing safeguards by design

    Energy Technology Data Exchange (ETDEWEB)

    Beyer, Brian David [Los Alamos National Laboratory; Beddingfield, David H [Los Alamos National Laboratory; Durst, Philip [INL; Bean, Robert [INL

    2010-01-01

    The design of the Pebble Bed Modular Reactor (PBMR) does not fit or seem appropriate to the IAEA safeguards approach under the categories of light water reactor (LWR), on-load refueled reactor (OLR, i.e. CANDU), or Other (prismatic HTGR) because the fuel is in a bulk form, rather than discrete items. Because the nuclear fuel is a collection of nuclear material inserted in tennis-ball sized spheres containing structural and moderating material and a PBMR core will contain a bulk load on the order of 500,000 spheres, it could be classified as a 'Bulk-Fuel Reactor.' Hence, the IAEA should develop unique safeguards criteria. In a multi-lab DOE study, it was found that an optimized blend of: (i) developing techniques to verify the plutonium content in spent fuel pebbles, (ii) improving burn-up computer codes for PBMR spent fuel to provide better understanding of the core and spent fuel makeup, and (iii) utilizing bulk verification techniques for PBMR spent fuel storage bins should be combined with the historic IAEA and South African approaches of containment and surveillance to verify and maintain continuity of knowledge of PBMR fuel. For all of these techniques to work the design of the reactor will need to accommodate safeguards and material accountancy measures to a far greater extent than has thus far been the case. The implementation of Safeguards-by-Design as the PBMR design progresses provides an approach to meets these safeguards and accountancy needs.

  19. Fuel analysis of a PBMR; Analisis de combustible de un PBMR

    Energy Technology Data Exchange (ETDEWEB)

    Bastida O, G. E.; Francois L, J. L., E-mail: gbo729@yahoo.com.mx [UNAM, Facultad de Ingenieria, Departamento de Sistemas Energeticos, Ciudad Universitaria, 04510 Ciudad de Mexico (Mexico)

    2015-09-15

    In this paper a neutronic analysis of fuel for a Pebble Bed Modular Reactor is presented, based on their composition and geometric distribution, having as main objective the use and utilization of thorium for the production of fuel for the operation of this reactor. For the study of these characteristics is necessary to use a code capable of carry out a reliable calculation of the main parameters of the fuel. Using the Monte Carlo method is suitable for simulating the neutron transport in the reactor core, which is the basis of Serpent code, with which the calculations for the analysis will be made. The results show the desirability of the use of thorium, since presents good conversion levels of fertile material to fissile, to produce U{sup 233} by neutron capture, taking as a very important factor the distribution of materials in the core, which in this work had better results based on the neutron multiplication effective factor, formed by three right circular cylinders circumscribed, making that the core has three areas constituted by a mixture of plutonium oxide in the central and external areas, and thorium oxide in the intermediate area. (Author)

  20. Optimisation of a storage facility used to effect power control in the PBMR power cycle

    OpenAIRE

    Mathews, Edward A; Pelzer, Ruaan; Matimba, A

    2008-01-01

    This article presents the optimization of a gas storage facility used to effect power control in South Africa's PBMR power cycle. It was shown in the article, a multitank storage facility to affect power control in the PBMR power cyclel, that a multi tank design with heat capacitance improves storage effictiveness, which could make the system cheaper. This storage facility is known as the Inventory Control System (ICS). The focus in this article is to determine an optimum numbe...

  1. Reactors

    CERN Document Server

    International Electrotechnical Commission. Geneva

    1988-01-01

    This standard applies to the following types of reactors: shunt reactors, current-limiting reactors including neutral-earthing reactors, damping reactors, tuning (filter) reactors, earthing transformers (neutral couplers), arc-suppression reactors, smoothing reactors, with the exception of the following reactors: small reactors with a rating generally less than 2 kvar single-phase and 10 kvar three-phase, reactors for special purposes such as high-frequency line traps or reactors mounted on rolling stock.

  2. STUDI MODEL ALIRAN FLUIDA DAN PERPINDAHAN PANAS PADA PBMR.

    Directory of Open Access Journals (Sweden)

    Achmad Fatich Al-Qodri

    2016-11-01

    Full Text Available Reaktor tipe Pebble bed merupakan opsi yang menjanjikan untuk teknologi reaktor generasi mendatang dan memiliki potensi untuk memberikan pembangkitan listrik dengan efisiensi tinggi dan murah.Perpindahan panas reaktor ini menghadapi kendala akibat kompleksitas yang berkaitan dengan desain aliran panas.Dengan demikian, untuk mensimulasikan secara baik aliran dan perpindahan panas reaktor modular pebble bed ini memerlukan suatu model perpindahan panas yang berhubungan dengan radiasi serta konveksi dan konduksi panas.Dalam studi ini, suatu model dengan kemampuan untuk mensimulasikan aliran fluida dan perpindahan panas dalam teras reaktor modular pebble bed telah dikembangkan.Model ini diterapkan pada suatu personal computer (PC yang menggunakan program komputer Matlab r2008a Versi 7.1.Beberapa parameter penting aliran fluida dan perpindahan panas telah dipelajari, termasuk penurunan tekanan (pressure drop di teras reaktor, koefisien perpindahan panas, bilangan Nusselt, dan konduktivitas panas efektif pebble bahan bakar. Hasil yang diperoleh dari percobaan simulasi menunjukkan adanya suatu tekanan yang merata pada arah radial untuk suatu rasio diameter teras terhadap elemen bakar (D/d > 20 dan koefisien perpindahan panas meningkat seiring dengan peningkatan temperatur dan laju alir massa pendingin. Model ini dapat menjelaskan secara memadai fenomena aliran panas dan perpindahan panas dan kehilangan tekanan melalui friksi dalam PBMR tipe pebble bed.

  3. The analysis of the OECD/NEA/NSC PBMR-400 benchmark problem using PARCS-DIREKT

    Energy Technology Data Exchange (ETDEWEB)

    Seker, V.; Downar, T. J. [Purdue Univ., 400 Central Drive, West Lafayette, IN 47907 (United States)

    2006-07-01

    The OECD/NEA/NSC PBMR-400 benchmark problem was developed to support the validation and verification efforts for the PBMR design. This paper describes the analysis of this problem using the PARCS-DIREKT coupled code system. The benchmark problem involved the use of two different cross-section libraries, one which was generated from a VSOP equilibrium core calculation and has no dependence on core conditions. The second library provides for dependence on five state parameters and was designed for transient analysis. The paper here reports the steady-state cases using the VSOP set of cross-sections. The results are shown to be in good agreement with those of VSOP. Also reported here are the results of the steady-state thermal-hydraulic DIRECKT solution with a given power profile obtained from VSOP equilibrium core calculation. This analysis provides some insight as to the most important parameters in the design of PBMR-400. (authors)

  4. Simulation of the automatic depressurization system (Ads) for a boiling water reactor (BWR) based on RELAP; Simulacion del sistema de despresurizacion automatica (ADS) para un reactor de agua en ebullicion (BWR) basado en RELAP

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez G, C.; Chavez M, C., E-mail: ces.raga@gmail.com [UNAM, Facultad de Ingenieria, Circuito Interior, Ciudad Universitaria, 04510 Mexico D. F. (Mexico)

    2012-10-15

    The automatic depressurization system (Ads) of the boiling water reactor (BWR) like part of the emergency cooling systems is designed to liberate the vapor pressure of the reactor vessel, as well as the main vapor lines. At the present time in the Engineering Faculty, UNAM personnel works in the simulation of the Laguna Verde reactor based on the nuclear code RELAP/SCADAP and in the incorporation to the same of the emergency cooling systems. The simulation of the emergency cooling systems began with the inclusion of two hydrodynamic volumes, one source and another drain, and the incorporation of the initiation logic for each emergency system. In this work is defined and designed a simplified model of Ads of the reactor, considering a detail level based on the main elements that compose it. As tool to implement the proposed model, the RELAP code was used. The simulated main functions of Ads are centered in the quick depressurization of the reactor by means of the vapor discharge through the relief/safety valves to the suppression pool, and, in the event of break of the main vapor line, the reduction of the vessel pressure operates for that the cooling systems of the core to low pressure (Lpcs and Lpci) they can begin their operation. (Author)

  5. Aprendizaje basado en juegos

    Directory of Open Access Journals (Sweden)

    Marco A. Gómez-Martín

    2012-04-01

    Full Text Available Gracias al incremento de potencia de los ordenadores, gran cantidad de personas dedican horas y horas a aprovechar su aspecto más lúdico, los videojuegos. Por otro lado, existen programas educativos que aprovechan la infinita paciencia de los ordenadores que les hacen capaces de explicar conceptos una y otra vez hasta que los alumnos lo entiendan. En este artículo mostramos qué cosas pueden aportar las aplicaciones de enseñanza a los videojuegos y viceversa. Terminamos describiendo JV2M, como un ejemplo de sistema de aprendizaje basado en juegos.

  6. Design of an equilibrium nucleus of a BWR type reactor based in a Thorium-Uranium fuel; Diseno de un nucleo de equilibrio de un reactor tipo BWR basado en un combustible de Torio-Uranio

    Energy Technology Data Exchange (ETDEWEB)

    Francois, J.L.; Nunez C, A. [Laboratorio de Analisis en Ingenieria de Reactores Nucleares, Facultad de Ingenieria-UNAM, Paseo Cuauhnahuac 8532, Jiutepec, Morelos (Mexico)

    2003-07-01

    In this work the design of the reactor nucleus of boiling water using fuel of thorium-uranium is presented. Starting from an integral concept based in a type cover-seed assemble is carried out the design of an equilibrium reload for the nucleus of a reactor like that of the Laguna Verde Central and its are analyzed some of the main design variables like the cycle length, the reload fraction, the burnt fuel, the vacuum distribution, the generation of lineal heat, the margin of shutdown, as well as a first estimation of the fuel cost. The results show that it is feasible to obtain an equilibrium reload, comparable to those that are carried out in the Laguna Verde reactors, with a good behavior of those analyzed variables. The cost of the equilibrium reload designed with the thorium-uranium fuel is approximately 2% high that the uranium reload producing the same energy. It is concluded that it is convenient to include burnable poisons, type gadolinium, in the fuel with the end of improving the reload design, the fuel costs and the margin of shutdown. (Author)

  7. The Effects of Laterite and Associated Terrain Components on PBMR Response in HAPEX-Sahel

    Science.gov (United States)

    Teng, William L.; Choudhury, Bhaskar J.; Wang, James R.

    1997-01-01

    Terrain characteristics such as roughness and vegetation have been shown to significantly affect the interpretation of microwave brightness temperatures (T(B)s) for mapping soil moisture. This study, a part of the 1992 HAPEX-Sahel experiment (Hydrologic Atmospheric Pilot Experiment in the Sahel), aimed to determine the effects of laterite and associated terrain components (i.e. vegetation, soil, and exposed water bodies) on the T(B) response of the Pushbroom Microwave Radiometer (PBMR, L-band, 21 cm wavelength), using the NS001 Thematic Mapper Simulator data as a surrogate for ground data. Coincident PBMR and NS001 data acquired from the high altitude (about 1500 m) long transect flights were processed to obtain TBs and radiances, respectively. The transects covered a range of moisture conditions. For this preliminary evaluation, no atmospheric corrections were applied, and the data sets were aligned by matching the acquisition times of the data records. NS001 pixels (about 4 m) were averaged to approximate the resolution of the PBMR (about 450 m), before their flight line data were compared. The laterite plateaux were found to have a surprisingly strong effect on the PBMR T(B) response. T(B) variations along the flight line could largely be explained by a combination of density and dielectric properties of laterite. The effect of surface moisture was distinguishable from the laterite effect, with the distinction apparently related to the occurrence of ephemeral pools of water after rainfall. Model simulated T(B)s agreed reasonably well with the observed T(B)s.

  8. The Pebble Bed Modular Reactor: An obituary

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, Steve, E-mail: stephen.thomas@gre.ac.u [Public Services International Research Unit (PSIRU), Business School, University of Greenwich, 30 Park Row, London SE10 9LS (United Kingdom)

    2011-05-15

    The High Temperature Gas-cooled Reactor (HTGR) has exerted a peculiar attraction over nuclear engineers. Despite many unsuccessful attempts over half a century to develop it as a commercial power reactor, there is still a strong belief amongst many nuclear advocates that a highly successful HTGR technology will emerge. The most recent attempt to commercialize an HTGR design, the Pebble Bed Modular Reactor (PBMR), was abandoned in 2010 after 12 years of effort and the expenditure of a large amount of South African public money. This article reviews this latest attempt to commercialize an HTGR design and attempts to identify which issues have led to its failure and what lessons can be learnt from this experience. It concludes that any further attempts to develop HTGRs using Pebble Bed technology should only be undertaken if there is a clear understanding of why earlier attempts have failed and a high level of confidence that earlier problems have been overcome. It argues that the PBMR project has exposed serious weaknesses in accountability mechanisms for the expenditure of South African public money. - Research highlights: {yields} In this study we examine the reasons behind the failure of the South African PBMR programme. {yields} The study reviews the technical issues that have arisen and lessons for future reactor developments. {yields} The study also identifies weaknesses in the accountability mechanisms for public spending.

  9. Multiphysics methods development for high temperature gas reactor analysis

    Science.gov (United States)

    Seker, Volkan

    Multiphysics computational methods were developed to perform design and safety analysis of the next generation Pebble Bed High Temperature Gas Cooled Reactors. A suite of code modules was developed to solve the coupled thermal-hydraulics and neutronics field equations. The thermal-hydraulics module is based on the three dimensional solution of the mass, momentum and energy equations in cylindrical coordinates within the framework of the porous media method. The neutronics module is a part of the PARCS (Purdue Advanced Reactor Core Simulator) code and provides a fine mesh finite difference solution of the neutron diffusion equation in three dimensional cylindrical coordinates. Coupling of the two modules was performed by mapping the solution variables from one module to the other. Mapping is performed automatically in the code system by the use of a common material mesh in both modules. The standalone validation of the thermal-hydraulics module was performed with several cases of the SANA experiment and the standalone thermal-hydraulics exercise of the PBMR-400 benchmark problem. The standalone neutronics module was validated by performing the relevant exercises of the PBMR-268 and PBMR-400 benchmark problems. Additionally, the validation of the coupled code system was performed by analyzing several steady state and transient cases of the OECD/NEA PBMR-400 benchmark problem.

  10. PEBBED Uncertainty and Sensitivity Analysis of the CRP-5 PBMR DLOFC Transient Benchmark with the SUSA Code

    Energy Technology Data Exchange (ETDEWEB)

    Gerhard Strydom

    2011-01-01

    The need for a defendable and systematic uncertainty and sensitivity approach that conforms to the Code Scaling, Applicability, and Uncertainty (CSAU) process, and that could be used for a wide variety of software codes, was defined in 2008. The GRS (Gesellschaft für Anlagen und Reaktorsicherheit) company of Germany has developed one type of CSAU approach that is particularly well suited for legacy coupled core analysis codes, and a trial version of their commercial software product SUSA (Software for Uncertainty and Sensitivity Analyses) was acquired on May 12, 2010. This report summarized the results of the initial investigations performed with SUSA, utilizing a typical High Temperature Reactor benchmark (the IAEA CRP-5 PBMR 400MW Exercise 2) and the PEBBED-THERMIX suite of codes. The following steps were performed as part of the uncertainty and sensitivity analysis: 1. Eight PEBBED-THERMIX model input parameters were selected for inclusion in the uncertainty study: the total reactor power, inlet gas temperature, decay heat, and the specific heat capability and thermal conductivity of the fuel, pebble bed and reflector graphite. 2. The input parameters variations and probability density functions were specified, and a total of 800 PEBBED-THERMIX model calculations were performed, divided into 4 sets of 100 and 2 sets of 200 Steady State and Depressurized Loss of Forced Cooling (DLOFC) transient calculations each. 3. The steady state and DLOFC maximum fuel temperature, as well as the daily pebble fuel load rate data, were supplied to SUSA as model output parameters of interest. The 6 data sets were statistically analyzed to determine the 5% and 95% percentile values for each of the 3 output parameters with a 95% confidence level, and typical statistical indictors were also generated (e.g. Kendall, Pearson and Spearman coefficients). 4. A SUSA sensitivity study was performed to obtain correlation data between the input and output parameters, and to identify the

  11. Oxygen distribution in packed bed membrane reactors for partial oxidation systems and the effect on the product selectivity

    NARCIS (Netherlands)

    Kürten, U.; Sint Annaland, van Martin; Kuipers, J.A.M.

    2004-01-01

    Packed bed membrane reactors (PBMRs) are currently considered for the distributive addition of oxygen in partial oxidation systems. Among other advantages the decreased oxygen concentrations in the PBMR can result in improved product selectivities for reaction systems in which the oxygen dependency

  12. From field to factory-Taking advantage of shop manufacturing for the pebble bed modular reactor

    Energy Technology Data Exchange (ETDEWEB)

    Wallace, Edward [PBMR Pty. Ltd. (South Africa)]. E-mail: edward.wallace@pbmr.co.za; Matzie, Regis [Westinghouse Electric Company LLC (United States); Heiderd, Roger [Sargent and Lundy LLC (United States); Maddalena, John [PBMR Pty. Ltd. (South Africa)

    2006-03-15

    The move of nuclear plant construction from the field to the factory for small, advanced pebble bed modular reactor (PBMR) designs has significant benefits compared to traditional light water reactor (LWR) field oriented designs. The use of modular factory construction techniques has a growing economic benefit over time through well-established process learning applications. This paper addresses the basic PBMR design objectives and commercialization model that drive this approach; provides a brief technical description of the PBMR design and layout with representative CAD views and discusses derived figures of merit highlighting the relative simplicity of PBMR compared to a modern LWR. The discussion emphasizes that more of PBMR can be built in the factory due to the simple design of a direct helium Brayton cycle compared to an indirect LWR steam cycle with its associated equipment. For the PBMR design there are fewer and less cumbersome auxiliary and safety systems with their attendant support requirements. Additionally, the labor force economic efficiency for nuclear projects is better in the factory than in the field, including consideration of labor costs and nuclear quality programs. Industrial learning is better in the factory because of the more controlled environment, mechanization optimization opportunities and because of the more stable labor force compared to the field. Supply chain benefits are more readily achievable with strategic contracts for module suppliers. Although building a nuclear power plant is not a typical high volume manufacturing process, for the PBMR-type of plant, with its high degree of standardization and relatively small, simplified design, the shift to factory work has a significant impact on overall project cost due to earlier identification and better coordination of parallel construction paths. This is in stark contrast to the construction of a large LWR in the past. Finally, the PBMR modular plant concept continues at the

  13. Reactor

    Science.gov (United States)

    Evans, Robert M.

    1976-10-05

    1. A neutronic reactor having a moderator, coolant tubes traversing the moderator from an inlet end to an outlet end, bodies of material fissionable by neutrons of thermal energy disposed within the coolant tubes, and means for circulating water through said coolant tubes characterized by the improved construction wherein the coolant tubes are constructed of aluminum having an outer diameter of 1.729 inches and a wall thickness of 0.059 inch, and the means for circulating a liquid coolant through the tubes includes a source of water at a pressure of approximately 350 pounds per square inch connected to the inlet end of the tubes, and said construction including a pressure reducing orifice disposed at the inlet ends of the tubes reducing the pressure of the water by approximately 150 pounds per square inch.

  14. Analysis of the light-current relationships in the optimized planar buried mesa ridge (PBMR) InGaAsP laser

    Science.gov (United States)

    Procházková, O.; Novotný, J.; Šrobár, F.

    1992-05-01

    Inclusion of the optimized composite waveguide concept in the InGaAsP/InP PBMR laser construction resulted in an improvement of the differential quantum efficiency value by more than ten per cent. Analysis of the kinetic equations for the carrier and photon populations was used to evaluate various contributions (radiative recombination, Auger processes, electron drift and parasitic leakage currents) to the threshold current in the optimized PBMR geometry.

  15. Costos basados en la actividad

    OpenAIRE

    Delicio, Fabián A.

    1998-01-01

    La metodología de Costos Basados en la Actividad (ABC) significa un importante cambio en la asignación de los costos de los productos. Su originalidad parte de relacionar la base de asignación para los costos indirectos con las actividades desarrolladas en cada uno de los departamentos o centros de costos. Introduce el concepto de Inductor de Costos, para la asignación de los costos, para la asignación de los costos y gastos fijos, que está determinado por las actividades que se realizan en e...

  16. Design and energy analysis of a electrolytic hydrogen production process by means of a high temperature nuclear reactor; Diseno y analisis energetico de un proceso de produccion de hidrogeno electrolitico por medio de un reactor nuclear de alta temperatura

    Energy Technology Data Exchange (ETDEWEB)

    Valle H, J.; Morales S, J. B. [UNAM, DEPFI Campus Morelos, Jiutepec, Morelos (Mexico)]. e-mail: julfi_jg@yahoo.com.mx

    2008-07-01

    In this work an energy analysis to a process of production of hydrogen by means of electrolysis of high temperature is realized. This electrolysis type, unlike conventional electrolysis allows us to reach efficiencies of up to 60% because when increasing the temperature of the water, providing to its thermal energy, diminishes the demand of electrical energy required to separate the molecule of the water. Nevertheless, to obtain these efficiencies it is needed to have superheated aqueous vapor to but of 850 centigrade degrees, temperatures that can be reached about high temperature reactor; HTGR. In the present work it is mentioned to introduction way the importance of the hydrogen like energy vector and the advantages of obtaining it by means of nuclear energy. The electrolysis process of high temperature is described and a design is realized of this from its coupling to a nuclear power plant PBMR. The technological advances on which it counts the PBMR; efficiencies of 48% for optimized plants, their modular design and the thermodynamic cycle recuperative Brayton where upon operate; make the short term ideal candidate for the production of hydrogen. The thermodynamic analysis of optimized plant PBMR appears in another work, here the results of the balance of mass and energy involved in the process appear of hydrogen generation and the complete analysis of this. The result is a complete model of generation of hydrogen by electrolysis of high temperature coupled to an optimized plant PBMR that will be implemented for its dynamic simulation later. (Author)

  17. Optimization of coupled multiphysics methodology for safety analysis of pebble bed modular reactor

    Science.gov (United States)

    Mkhabela, Peter Tshepo

    The research conducted within the framework of this PhD thesis is devoted to the high-fidelity multi-physics (based on neutronics/thermal-hydraulics coupling) analysis of Pebble Bed Modular Reactor (PBMR), which is a High Temperature Reactor (HTR). The Next Generation Nuclear Plant (NGNP) will be a HTR design. The core design and safety analysis methods are considerably less developed and mature for HTR analysis than those currently used for Light Water Reactors (LWRs). Compared to LWRs, the HTR transient analysis is more demanding since it requires proper treatment of both slower and much longer transients (of time scale in hours and days) and fast and short transients (of time scale in minutes and seconds). There is limited operation and experimental data available for HTRs for validation of coupled multi-physics methodologies. This PhD work developed and verified reliable high fidelity coupled multi-physics models subsequently implemented in robust, efficient, and accurate computational tools to analyse the neutronics and thermal-hydraulic behaviour for design optimization and safety evaluation of PBMR concept The study provided a contribution to a greater accuracy of neutronics calculations by including the feedback from thermal hydraulics driven temperature calculation and various multi-physics effects that can influence it. Consideration of the feedback due to the influence of leakage was taken into account by development and implementation of improved buckling feedback models. Modifications were made in the calculation procedure to ensure that the xenon depletion models were accurate for proper interpolation from cross section tables. To achieve this, the NEM/THERMIX coupled code system was developed to create the system that is efficient and stable over the duration of transient calculations that last over several tens of hours. Another achievement of the PhD thesis was development and demonstration of full-physics, three-dimensional safety analysis

  18. The Application of the PEBBED Code Suite to the PBMR-400 Coupled Code Benchmark - FY 2006 Annual Report

    Energy Technology Data Exchange (ETDEWEB)

    2006-09-01

    This document describes the recent developments of the PEBBED code suite and its application to the PBMR-400 Coupled Code Benchmark. This report addresses an FY2006 Level 2 milestone under the NGNP Design and Evaluation Methods Work Package. The milestone states "Complete a report describing the results of the application of the integrated PEBBED code package to the PBMR-400 coupled code benchmark". The report describes the current state of the PEBBED code suite, provides an overview of the Benchmark problems to which it was applied, discusses the code developments achieved in the past year, and states some of the results attained. Results of the steady state problems generated by the PEBBED fuel management code compare favorably to the preliminary results generated by codes from other participating institutions and to similar non-Benchmark analyses. Partial transient analysis capability has been achieved through the acquisition of the NEM-THERMIX code from Penn State University. Phase I of the task has been achieved through the development of a self-consistent set of tools for generating cross sections for design and transient analysis and in the successful execution of the steady state benchmark exercises.

  19. Process heat cogeneration using a high temperature reactor

    Energy Technology Data Exchange (ETDEWEB)

    Alonso, Gustavo, E-mail: gustavoalonso3@gmail.com [Instituto Nacional de Investigaciones Nucleares, Carretera Mexico-Toluca s/n, Ocoyoacac, Edo. De Mexico 52750 (Mexico); Instituto Politécnico Nacional, Unidad Profesional Adolfo Lopez Mateos, Ed. 9, Lindavista, D.F. 07300 (Mexico); Ramirez, Ramon [Instituto Nacional de Investigaciones Nucleares, Carretera Mexico-Toluca s/n, Ocoyoacac, Edo. De Mexico 52750 (Mexico); Valle, Edmundo del [Instituto Politécnico Nacional, Unidad Profesional Adolfo Lopez Mateos, Ed. 9, Lindavista, D.F. 07300 (Mexico); Castillo, Rogelio [Instituto Nacional de Investigaciones Nucleares, Carretera Mexico-Toluca s/n, Ocoyoacac, Edo. De Mexico 52750 (Mexico)

    2014-12-15

    Highlights: • HTR feasibility for process heat cogeneration is assessed. • A cogeneration coupling for HTR is proposed and process heat cost is evaluated. • A CCGT process heat cogeneration set up is also assessed. • Technical comparison between both sources of cogeneration is performed. • Economical competitiveness of the HTR for process heat cogeneration is analyzed. - Abstract: High temperature nuclear reactors offer the possibility to generate process heat that could be used in the oil industry, particularly in refineries for gasoline production. These technologies are still under development and none of them has shown how this can be possible and what will be the penalty in electricity generation to have this additional product and if the cost of this subproduct will be competitive with other alternatives. The current study assesses the likeliness of generating process heat from Pebble Bed Modular Reactor to be used for a refinery showing different plant balances and alternatives to produce and use that process heat. An actual practical example is presented to demonstrate the cogeneration viability using the fact that the PBMR is a modular small reactor where the cycle configuration to transport the heat of the reactor to the process plant plays an important role in the cycle efficiency and in the plant economics. The results of this study show that the PBMR would be most competitive when capital discount rates are low (5%), carbon prices are high (>30 US$/ton), and competing natural gas prices are at least 8 US$/mmBTU.

  20. Membrane reactor for water detritiation: a parametric study on operating parameters

    Energy Technology Data Exchange (ETDEWEB)

    Mascarade, J.; Liger, K.; Troulay, M.; Perrais, C. [CEA, DEN, DTN/STPA/LIPC, Centre de Cadarache, Saint-Paul-lez-Durance (France); Joulia, X.; Meyer, X.M. [Universite de Toulouse, INPT, UPS, Laboratoire de Genie Chimique, Toulouse (France); CNRS, Laboratoire de Genie Chimique, Toulouse (France)

    2015-03-15

    This paper presents the results of a parametric study done on a single stage finger-type packed-bed membrane reactor (PBMR) used for heavy water vapor de-deuteration. Parametric studies have been done on 3 operating parameters which are: the membrane temperature, the total feed flow rate and the feed composition through D{sub 2}O content variations. Thanks to mass spectrometer analysis of streams leaving the PBMR, speciation of deuterated species was achieved. Measurement of the amounts of each molecular component allowed the calculation of reaction quotient at the packed-bed outlet. While temperature variation mainly influences permeation efficiency, feed flow rate perturbation reveals dependence of conversion and permeation properties to contact time between catalyst and reacting mixture. The study shows that isotopic exchange reactions occurring on the catalyst particles surface are not thermodynamically balanced. Moreover, the variation of the heavy water content in the feed exhibits competition between permeation and conversion kinetics.

  1. Simulation of the aspersion system of the core low pressure (LPCS) for a boiling water reactor (BWR) based on RELAP; Simulacion del sistema de aspersion del nucleo a baja presion (LPCS) para un reactor de agua en ebullicion (BWR) basado en RELAP

    Energy Technology Data Exchange (ETDEWEB)

    Membrillo G, O. E.; Chavez M, C., E-mail: garzo1012@gmail.com [UNAM, Facultad de Ingenieria, Circuito Interior, Ciudad Universitaria, 04510 Mexico D. F. (Mexico)

    2012-10-15

    The present work presents the modeling and simulation of the aspersion system to low pressure of reactor of the nuclear power plant of Laguna Verde using the nuclear code RELAP/SCDAP. The objective of the emergency systems inside a nuclear reactor is the cooling of the core, nor caring the performance of any other emergency system in the case of an accident design base for coolant loss. To obtain a simulation of the system is necessary to have a model based on their main components, pipes, pumps, valves, etc. This article describes the model for the simulation of the main line and the test line for the HPCS. At the moment we have the simulation of the reactor vessel and their systems associated to the nuclear power plant of Laguna Verde, this work will allow to associate the emergency system model LPCS to the vessel model. The simulation of the vessel and the emergency systems will allow knowing the behavior of the reactor in the stage of the coolant loos, giving the possibility to analyze diverse scenarios. The general model will provide an auxiliary tool for the training in classroom and at distance in the operation of nuclear power plants. (Author)

  2. RETOS DEL APRENDIZAJE BASADO EN PROBLEMAS

    National Research Council Canada - National Science Library

    Carlos Antonio Poot-Delgado

    2013-01-01

    Se realiza una breve descripción de la viabilidad y retos de llevar a la práctica docente el aprendizaje basado en problemas, con una estructura organizada, donde se plasman ideas bien fundamentadas con claridad y precisión...

  3. Development of a system based in a digital signal processor (DSP) for a simulator of power regulation in a reactor: first stage; Desarrollo de un sistema basado en un DSP para un simulador de regulacion de potencia en un reactor: 1. etapa

    Energy Technology Data Exchange (ETDEWEB)

    Benitez R, J.S.; Perez C, B. [Instituto Nacional de Investigaciones Nucleares, Km. 36.5 Carretera Mexico-Toluca, Municipio de Ocoyoacac, 52045 Estado de Mexico (Mexico)

    2002-07-01

    The first stage of the development of a digital system based on a DSP is presented which forms part of an hybrid simulator for the power regulation in am model of the punctual kinetics of a TRIGA reactor type. The DSP performs the regulation, using a Mandami type algorithm of diffuse control. In the algorithm, the universe of the output variable is discretized for performing in an unique stage the aggregation functions and dis-diffusization. (Author)

  4. Material Control and Accounting Design Considerations for High-Temperature Gas Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Trond Bjornard; John Hockert

    2011-08-01

    The subject of this report is domestic safeguards and security by design (2SBD) for high-temperature gas reactors, focusing on material control and accountability (MC&A). The motivation for the report is to provide 2SBD support to the Next Generation Nuclear Plant (NGNP) project, which was launched by Congress in 2005. This introductory section will provide some background on the NGNP project and an overview of the 2SBD concept. The remaining chapters focus specifically on design aspects of the candidate high-temperature gas reactors (HTGRs) relevant to MC&A, Nuclear Regulatory Commission (NRC) requirements, and proposed MC&A approaches for the two major HTGR reactor types: pebble bed and prismatic. Of the prismatic type, two candidates are under consideration: (1) GA's GT-MHR (Gas Turbine-Modular Helium Reactor), and (2) the Modular High-Temperature Reactor (M-HTR), a derivative of Areva's Antares reactor. The future of the pebble-bed modular reactor (PBMR) for NGNP is uncertain, as the PBMR consortium partners (Westinghouse, PBMR [Pty] and The Shaw Group) were unable to agree on the path forward for NGNP during 2010. However, during the technology assessment of the conceptual design phase (Phase 1) of the NGNP project, AREVA provided design information and technology assessment of their pebble bed fueled plant design called the HTR-Module concept. AREVA does not intend to pursue this design for NGNP, preferring instead a modular reactor based on the prismatic Antares concept. Since MC&A relevant design information is available for both pebble concepts, the pebble-bed HTGRs considered in this report are: (1) Westinghouse PBMR; and (2) AREVA HTR-Module. The DOE Office of Nuclear Energy (DOE-NE) sponsors the Fuel Cycle Research and Development program (FCR&D), which contains an element specifically focused on the domestic (or state) aspects of SBD. This Material Protection, Control and Accountancy Technology (MPACT) program supports the present work

  5. Generation IV Nuclear Energy Systems Construction Cost Reductions through the Use of Virtual Environments - Task 5 Report: Generation IV Reactor Virtual Mockup Proof-of-Principle Study

    Energy Technology Data Exchange (ETDEWEB)

    Timothy Shaw; Anthony Baratta; Vaughn Whisker

    2005-02-28

    Task 5 report is part of a 3 year DOE NERI-sponsored effort evaluating immersive virtual reality (CAVE) technology for design review, construction planning, and maintenance planning and training for next generation nuclear power plants. Program covers development of full-scale virtual mockups generated from 3D CAD data presented in a CAVE visualization facility. Created a virtual mockup of PBMR reactor cavity and discussed applications of virtual mockup technology to improve Gen IV design review, construction planning, and maintenance planning.

  6. PBMR 400 Coupled Code Benchmark: Challenges and Successes with NEM-THERMIX

    Energy Technology Data Exchange (ETDEWEB)

    Javier Ortensi

    2006-06-01

    Presented are preliminary results of a sensitivity study on mesh sizing and diffusion coefficient on a the core multiplication factor in a pebble bed reactor core simulation. Nonphysical behavior is observed for ranges of mesh size and diffusion coefficients. A guideline was established for avoiding this problem in subsequent models.

  7. Simulation of the aspersion system of the core at high pressure (HPCS) for a boiling water reactor (BWR) based on RELAP; Simulacion del sistema de aspersion del nucleo alta presion (HPCS) para un reactor de agua en ebullicion (BWR) basado en RELAP

    Energy Technology Data Exchange (ETDEWEB)

    Vargas O, D.; Chavez M, C., E-mail: danmirnyi@gmail.com [UNAM, Facultad de Ingenieria, Circuito Interior, Ciudad Universitaria, 04510 Mexico D. F. (Mexico)

    2012-10-15

    A high-priority topic for the nuclear industry is the safety, consequently a nuclear power plant should have the emergency systems of cooling of the core (ECCS), designed exclusively to enter in operation in the event of an accident with coolant loss, including the design base accident. The objective of the aspersion system of the core at high pressure (HPCS) is to provide in an autonomous way the cooling to the core maintaining for if same the coolant inventory even when a small break is presented that does not allow the depressurization of the reactor and also avoiding excessive temperatures that affect the shielding of the fuel. The present work describes the development of the model and the simulation of the HPCS using the RELAP/SCDAP code. During the process simulation, for the setting in march of the system HPCS in an accident with coolant loss is necessary to implement the main components of the system taking into account what unites them, the main pump, the filled pump, the suction and injection valves, pipes and its water sources that can be condensed storage tanks and the suppression pool. The simulation of this system will complement the model with which counts the Analysis Laboratory in Nuclear Reactors Engineering of the UNAM regarding to the nuclear power plant of Laguna Verde which does not have a detailed simulation of the emergency cooling systems. (Author)

  8. y el de aprendizaje basado en problemas

    Directory of Open Access Journals (Sweden)

    Aixa Lanett Powell Franco

    2006-01-01

    Full Text Available Las técnicas didácticas de aprendizaje basado en problemas y el método de casos han sido empleadas en destacadas instituciones de todo el mundo para la enseñanza de varias disciplinas. El objetivo general de esta investigación fue identificar si hay diferencias significativas en el desempeño de los alumnos que toman el curso de Psicología en el idioma inglés mediante el aprendizaje basado en problemas y el método de casos, ambos combinados con el aprendizaje colaborativo. Participaron 61 alumnos, de los cuales 23 llevaron el curso con el primer método y 38 con el segundo, no hallándose diferencias significativas entre ambos grupos.

  9. Research on high temperature reactors cooled gas: CIEMAT contribution to the analysis of safety containment; Investigacion en reactores de alta temperatura refrigerados por gas: contribucion de Ciemat al analisis de seguridad del confirnamiento

    Energy Technology Data Exchange (ETDEWEB)

    Herranz, L. E.; Fontanet, J.

    2010-07-01

    CIEMAT has collaborated with PBMR Limited in the confinement safety studies of the potentially first commercial scale HTR (High Temperature Reactor) reactor. Framed within one of the most controversial areas brought up by the HTR technology, the containment-confinement dilemma, CIEMAT has carried out analyses of postulated accident scenarios considered in the licensing basis report. By characterizing thermal-hydraulic responses and radioactivity retention efficiency of the several confinement designs explored, CIEMAT has highlighted the stability and the outstanding filtration capability of the filtered venting proposed in the base design, which could be even enhanced by a coupling in series of wet and high-efficient dry filtration devices. (Author) 27 refs.

  10. Simulation of the injection system of cooling water to low pressure (Lpci) for a boiling water reactor (BWR) based on RELAP; Simulacion del sistema de inyeccion de agua de refrigeracion a baja presion (LPCI) para un reactor de agua en ebullicion (BWR) basado en RELAP

    Energy Technology Data Exchange (ETDEWEB)

    Delgado C, R. A.; Lopez S, E.; Chavez M, C., E-mail: renedelgado2015@hotmail.com [UNAM, Facultad de Ingenieria, Circuito Interior, Ciudad Universitaria, 04510 Mexico D. F. (Mexico)

    2012-10-15

    The present article describes the modeling and simulation of the Injection System of Cooling Water to Low Pressure (Lpci) for the nuclear power plant of Laguna Verde. Is very important to be able to predict the behavior of the nuclear plant in the case of an emergency stop, and while nearer to the reality are the results of a simulation, better is the safety protocol that can be devised. In the Engineering Faculty of the UNAM at the present is had logical models of the safety systems, but due to the nature of the same, these simulations do not provide of the quantity of enough information to be able to reproduce with more accuracy the behavior of the Lpci in the case of a severe accident. For this reason, the RELAP code was used for the flows modeling, components and structures of heat transfers in relation to the system Lpci. The modeling of the components is carried out with base on technical information of the nuclear plant and the results will be corroborated with information in reference documents as the Rasp (the Reactor analysis support package) and the Fsar (Final safety analysis report) for the nuclear power plant of Laguna Verde. (Author)

  11. 燃烧反应堆级钚的PBMR-400不同燃料循环特性

    Institute of Scientific and Technical Information of China (English)

    Eben Mulder; Eberhard Teuchert; 刘金华(译); 霍松岷(校)

    2011-01-01

    第四代堆型高温气冷堆最显著的特点是应用上的多功能性。高温气冷堆除具有发电功能外,还可淡化海水(多效蒸馏配置额外热或反渗透配置额外电流)和生产氢气(配置额外电流)。本文展示了球床堆概念的在线燃料特性,该反应堆燃烧反应堆级钚,并同时发电。利用VSOP-A法规系统,通过计算,阐明了采用Pu-Th/U先进燃料循环的标准PBMR-400商用反应堆设计如何提供类似的固有安全性特点。这意味着为实现这种燃料循环,设计上不必有重大的改变。此外,球形燃料概念的灵活性在于一种类型球中装载易裂变物质,而另一种类型容纳了可裂变或可转换物质。

  12. Nuclear Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Hogerton, John

    1964-01-01

    This pamphlet describes how reactors work; discusses reactor design; describes research, teaching, and materials testing reactors; production reactors; reactors for electric power generation; reactors for supply heat; reactors for propulsion; reactors for space; reactor safety; and reactors of tomorrow. The appendix discusses characteristics of U.S. civilian power reactor concepts and lists some of the U.S. reactor power projects, with location, type, capacity, owner, and startup date.

  13. Core Optimization of a Deep-Burn Pebble Bed Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Brian Boer; Abderrafi M. Ougouag

    2010-06-01

    Achieving a high fuel burnup in the Deep-Burn (DB) pebble bed reactor design, while remaining within the limits for fuel temperature, power peaking and temperature reactivity feedback, is challenging. The high content of Pu and Minor Actinides in the Deep-Burn fuel significantly impacts the thermal neutron energy spectrum as compared to a ’standard’ UO2 fueled core. This can result in power and temperature peaking in the pebble bed core in locally thermalized regions near the graphite reflectors. Furthermore, the interplay of the Pu resonances of the neutron absorption cross sections at low-lying energies can lead to a positive temperature reactivity coefficient for the graphite moderator at certain operating conditions. The DB concept focuses on the destruction of spent fuel transuranics in TRISO coated particle fueled gas-cooled reactors with the aim of a fractional fuel burnup of 60-70% in fissions per initial metal atom (FIMA), using a single-pass, multi in-core fuel (re)cycling scheme. In principle, the DB pebble bed concept employs the same reactor designs as the present low enriched uranium core designs, i.e. the 400 MWth Pebble Bed Modular Reactor (PBMR-400). A Pu and Minor Actinide fueled PBMR-400 design serves as the starting point for a core optimization study. The fuel temperature, power peak, temperature reactivity coefficients, and burnup capabilities of the modified designs are analyzed with the PEBBED code. A code-to-code coupling with the PASTA code allows for the analysis of the TRISO fuel performance for both normal and Loss Of Forced Cooling conditions. An improved core design is sought, maximizing the fuel discharge burnup, while retaining negative temperature reactivity feedback coefficients for the entire temperature range and avoiding high fuel temperatures (fuel failure probabilities).

  14. RETOS DEL APRENDIZAJE BASADO EN PROBLEMAS

    Directory of Open Access Journals (Sweden)

    Carlos Antonio Poot-Delgado

    2013-01-01

    Full Text Available Se realiza una breve descripción de la viabilidad y retos de llevar a la práctica docente el aprendizaje basado en problemas, con una estructura organizada, donde se plasman ideas bien fundamentadas con claridad y precisión. Asimismo, se plantean reflexiones pertinentes, mediante ejercicios alusivos y ubicados en la práctica docente. Es decir, una forma de trabajo que puede ser usada por el edu- cador en una parte de su curso, combinado con otras técnicas didácticas y de- limitando los objetivos de aprendizaje que desea cubrir. Este tipo de aprendizaje estimula ciertas habilidades cognitivas que son incitadas en menor grado me- diante métodos tradicionales, permitiendo promover aprendizajes, tales como pensamiento crítico, creatividad, toma de decisiones en situaciones nuevas y habilidades comunicativas.

  15. Sistemas basados en conocimiento usando Prolog

    Directory of Open Access Journals (Sweden)

    Zenaida García Valdivia

    2011-10-01

    Full Text Available Se exponen algunos de los resultados alcanzados en la Universidad Central "Marta Abreu" de Las Villas en cuanto al uso de un lenguaje de Programación Lógica (Prolog en la elaboración de Sistemas Basados en Conocimiento para diferentes áreas del saber como son la medicina, soldadura, educación, sistemas eléctricos de potencia, entre otros. Todos los sistemas elaborados utilizan el paradigma de la programación lógica para la representación del conocimiento de los expertos en los temas en cuestión y además hacen uso de entornos agradables a los usuarios a través interfaces visuales elaboradas en ambientes de programación para súper lenguajes ó utilizan un conjunto de herramientas para la elaboración de sistemas sobre la Web

  16. Fuel development for gas-cooled fast reactors

    Science.gov (United States)

    Meyer, M. K.; Fielding, R.; Gan, J.

    2007-09-01

    The Generation IV Gas-cooled Fast Reactor (GFR) concept is proposed to combine the advantages of high-temperature gas-cooled reactors (such as efficient direct conversion with a gas turbine and the potential for application of high-temperature process heat), with the sustainability advantages that are possible with a fast-spectrum reactor. The latter include the ability to fission all transuranics and the potential for breeding. The GFR is part of a consistent set of gas-cooled reactors that includes a medium-term Pebble Bed Modular Reactor (PBMR)-like concept, or concepts based on the Gas Turbine Modular Helium Reactor (GT-MHR), and specialized concepts such as the Very High-Temperature Reactor (VHTR), as well as actinide burning concepts [A Technology Roadmap for Generation IV Nuclear Energy Systems, US DOE Nuclear Energy Research Advisory Committee and the Generation IV International Forum, December 2002]. To achieve the necessary high power density and the ability to retain fission gas at high temperature, the primary fuel concept proposed for testing in the United States is dispersion coated fuel particles in a ceramic matrix. Alternative fuel concepts considered in the US and internationally include coated particle beds, ceramic clad fuel pins, and novel ceramic 'honeycomb' structures. Both mixed carbide and mixed nitride-based solid solutions are considered as fuel phases.

  17. STUDI DESAIN DOWN SCALE TERAS REAKTOR DAN BAHAN BAKAR PLTN JENIS PEBBLE BED MODULAR REACTOR – HTR 100 MWe

    Directory of Open Access Journals (Sweden)

    Slamet Parmanto

    2015-04-01

    Full Text Available Telah dilakukan penelitian terhadap teras reaktor Pebble Bed Modular Reactor (PBMR dengan daya 100 Mwe berbahan bakar UO2. Reaktor ini menggunakan moderator grafit dan helium sebagai pendingin. Studi down scale dilakukan tanpa mengubah geometri teras maupun geometri bahan bakar. Parameter yang dianalisis adalah kritikalitas teras, reaktivitas lebih, koefisien reaktivitas temperatur bahan bakar, moderator dan pendingin serta nilai ekonomis bahan bakar. Dari penelitian ini diharapkan diperoleh desain bahan bakar yang bernilai ekonomis dan memiliki fitur keselamatan melekat. Penelitian dilakukan dengan menggunakan program SRAC 2003. Hasil yang diperoleh adalah desain bahan bakar UO2 berbentuk pebble dengan pengkayaan 10% U235 dan 90 ppm racun dapat bakar Gd2O3. Nilai faktor multipilkasi effektif keff pada beginning of life (BOL adalah 1,01115 dan menjadi 1,00588 setelah 2658 hari operasi reaktor (EOL. Koefisien reaktivitas temperatur total diperoleh sebesar - 3,25900E-05 ∆k/k/K saat BOL dan -1,10615E-04 ∆k/k/K saat end of life (EOL. Reaktor ini memenuhi karakteristik keselamatan melekat ditandai dengan nilai koefisien reaktivitas temperatur yang negatif. Kata kunci: PBMR, desain bahan bakar, faktor multipilkasi effektif, reaktivitas lebih, koefisien reaktivitas temperatur.   Research of Pebble Bed Modular Reactor (PBMR 100 MWe which used UO2 fuel has been done. This reactor uses graphite as moderator and helium as coolant. Down scale studies performed without changing the core and fuel geometry. The parameter being analyzed were core criticality, excess reactivity, fuel, moderator, coolant temperature reactivity coefficient, and fuel economy. This research is expected to obtain the design that has fuel economy and inherent safety features. In this research, we have employed SRAC 2003 code. The calculation show that the UO2 pebble fuel design with 10% enrichment of U235 and 90 ppm burnable poison of Gd2O3 results in the effective multiplication

  18. An overview of the FZJ-tools for HTR core design and reactor dynamics, the past, present and future

    Energy Technology Data Exchange (ETDEWEB)

    Reitsma, F. [Nuclear Engineering Analysis (NEA), PBMR (Pty Ltd), cennturion (South Africa); Rutten, H.J.; Scherer, W. [Forschungzentrum Julich GmbH, Institute for Safety Research and Reactor Technology, Julich (Germany)

    2005-07-01

    The development of the pebble-bed type high-temperature reactor in Germany was actively supported by the research centre Juelich (FZJ, former KFA) i.e. with the development of theoretical methods and computational tools to perform core neutronics design, reactor operation simulation and transient analysis. The tools, developed as the outcome of research activities, made huge contributions not only to the understanding of the technology and its physical behaviour but were also used in support of licensing of German HTR projects. Today these codes are used in the design and licensing of current commercial projects such as the Pebble Bed Modular Reactor (PBMR) but is also used to design the upcoming Gen IV reactors of HTR pebble-bed type. The renewed interest in these codes especially with respect to the pebble-bed designs is due to their unique features such as the fuel management algorithms, the simultaneous treatment of nuclear, thermal-hydraulic and fluid-dynamic problems and the description of fast and long-term transients. The paper provides an overview of the codes VSOP and TINTE, provides an update of recent developments in the codes and gives specific examples of applications such as the PBMR 400 MW running-in phase, a comparison with the SANA pebble bed effective thermal conductivity experiment and very recent results obtained simulating the corrosion due to an air ingress event simulated in the NACOK facility. Finally some ideas on the future development of these codes are discussed. (authors)

  19. An earthquake transient method for pebble-bed reactors and a fuel temperature model for TRISO fueled reactors

    Science.gov (United States)

    Ortensi, Javier

    This investigation is divided into two general topics: (1) a new method for analyzing the safe shutdown earthquake event in a pebble bed reactor core, and (2) the development of an explicit tristructural-isotropic fuel model for high temperature reactors. The safe shutdown earthquake event is one of the design basis accidents for the pebble bed reactor. The new method captures the dynamic geometric compaction of the pebble bed core. The neutronic and thermal-fluids grids are dynamically re-meshed to simulate the re-arrangement of the pebbles in the reactor during the earthquake. Results are shown for the PBMR-400 assuming it is subjected to the Idaho National Laboratory's design basis earthquake. The study concludes that the PBMR-400 can safely withstand the reactivity insertions induced by the slumping of the core and the resulting relative withdrawal of the control rods. This characteristic stems from the large negative Doppler feedback of the fuel. This Doppler feedback mechanism is a major contributor to the passive safety of gas-cooled, graphite-moderated, high-temperature reactors that use fuel based on TRISO particles. The correct prediction of the magnitude and time-dependence of this feedback effect is essential to the conduct of safety analyses for these reactors. An explicit TRISO fuel temperature model named THETRIS has been developed in this work and incorporated in the CYNOD-THERMIX-KONVEK suite of coupled codes. The new model yields similar results to those obtained with more complex methods, requiring multi-TRISO calculations within one control volume. The performance of the code during fast and moderately-slow transients is verified. These analyses show how explicit TRISO models improve the predictions of the fuel temperature, and consequently, of the power escalation. In addition, a brief study of the potential effects on the transient behavior of high-temperature reactors due to the presence of a gap inside the TRISO particles is included

  20. El articulador: aprendizaje basado en integraciones (ABI

    Directory of Open Access Journals (Sweden)

    Gilberto Hernández Zinzún

    2010-03-01

    Full Text Available Se analiza la emergencia del concepto de “articulador” dentro de la estrategia pedagógica del aprendizaje basado en problemas (ABP. A través de esta los miembros de un grupo de trabajo recuperan información que les permite examinar un problema desde distintos puntos de vista. Mediante la experiencia de trabajo entre profesores, entre estudiantes y entre ambos, el articulador funciona como eje de integración de conocimientos que responden a aspectos particulares del problema, que son definidos y reflexionados por el grupo. Abstract The article of analyzes the emergence of the concept ≪articulator≫ in the pedagogical strategy of problem-based learning (ABP. Through this strategy the members of a working group recover information that allows them to examine a problem from different points of view. Through the experience of work between professors, between students and between them, the articulator works like axis of integration of knowledge that respond to particular aspects of the problem, which are defined and reflected by the group.

  1. Improved Prediction of the Temperature Feedback in TRISO-Fueled Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Javier Ortensi; Abderrafi M. Ougouag

    2009-08-01

    The Doppler feedback mechanism is a major contributor to the passive safety of gas-cooled, graphite-moderated high temperature reactors that use fuel based on Tristructural-Isotropic coated particles. It follows that the correct prediction of the magnitude and time-dependence of this feedback effect is essential to the conduct of safety analyses for these reactors. We present a fuel conduction model for obtaining better estimates of the temperature feedback during moderate and fast transients. The fuel model has been incorporated in the CYNOD-THERMIX-KONVEK suite of coupled codes as a single TRISO particle within each calculation cell. The heat generation rate is scaled down from the neutronic solution and a Dirichlet boundary condition is imposed as the bulk graphite temperature from the thermal-hydraulic solution. This simplified approach yields similar results to those obtained with more complex methods, requiring multi-TRISO calculations within one control volume, but with much less computational effort. An analysis of the hypothetical total control ejection in the PBMR-400 design verifies the performance of the code during fast transients. In addition, the analysis of the earthquake-initiated event in the PBMR-400 design verifies the performance of the code during slow transients. These events clearly depict the improvement in the predictions of the fuel temperature, and consequently, of the power escalations. In addition, a brief study of the potential effects of particle layer de-bonding on the transient behavior of high temperature reactors is included. Although the formation of a gap occurs under special conditions its consequences on the dynamic behavior of the reactor should be analyzed. The presence of a gap in the fuel can cause some unusual reactor behavior during fast transients, but still the reactor shuts down due to the strong feedback effects.

  2. APRENDIZAJE BASADO EN PROBLEMAS Y RAZONAMIENTO BASADO EN CASOS EN LA ENSEÑANZA

    Directory of Open Access Journals (Sweden)

    Juan Pedro Febles Rodríguez

    2002-05-01

    Full Text Available

    El el trabajo se hace una valoración sobre la utilización del Razonamiento Basado en Caso, como eficaz complemento en la formación profesional del alumno de Medicina, ya que este tipo de sistema utiliza un mecanismo de razonamiento por analogías o asociaciones de forma automática, muy similar a como lo realiza el humano. Esto permitirá que ante la presentación de un problema (teniendo en cuenta los principales aspectos destacados sobre el Aprendizaje Basado en Problemas, PBL, en las distintas bases de conocimientos que se conformen y que estarán constituidas por casos reales o supuestos, prototipos y excepcionales, en número suficiente y aportadas por los profesores, quienes fungirán como expertos, los educandos busquen respuestas a sus inquietudes.

  3. Sistema de inferencia difusa basado en relaciones Booleanas

    Directory of Open Access Journals (Sweden)

    Helbert Eduardo Espitia Cuchango

    2010-09-01

    Full Text Available Este documento describe la estructura de un sistema de inferencia difusa basado en relaciones booleanas. La teoría relacionada con lógica y conjuntos booleanos es una buena herramienta para el diseño de automatismos y sistemas digitales. Una variación con la cual se busca mejorar los sistemas basados en automatismos consiste en emplear conjuntos difusos en lugar de booleanos. Lo anterior se realiza con el objetivo de tener una acción continua en el actuador del automatismo. Al realizar esta variación y al aplicar la metodología de diseño de los sistemas de automatismos, aparecen los sistemas de inferencia difusa basados en relaciones booleanas.Aunque inicialmente esta propuesta se realizó considerando sistemas de automatismos, se observa que es posible extenderla a sistemas de inferencia difusa.

  4. Control predictivo basado en predictores borrosos

    Directory of Open Access Journals (Sweden)

    MIGUEL ANGEL RODRIGUEZ BORROTO

    2007-01-01

    Full Text Available En el presente artículo se expone un algoritmo para aplicar las técnicas de control predictivo lineal basadas en el modelo (MPC al caso de procesos no lineales utilizando un predictor borroso (fuzzy, en base a la estructura Takagi_Sugeno_Kang_dinámica y bajo el principio de utilización de modelos lineales locales por tramos. Ello conduce inherentemente, a un proceso de adaptación de la matriz dinámica del sistema en cada periodo de muestreo, lo cual se considera novedoso en relación al MPC clásico. Se exponen los resultados de su aplicación al caso de un control de posición que utiliza un servo-motor de corriente continua con zona muerta y a un reactor continuo de tanque con agitador con reacción exotérmica. Los resultados son satisfactorios

  5. H Reactor

    Data.gov (United States)

    Federal Laboratory Consortium — The H Reactor was the first reactor to be built at Hanford after World War II.It became operational in October of 1949, and represented the fourth nuclear reactor on...

  6. Preliminary materials selection issues for the next generation nuclear plant reactor pressure vessel.

    Energy Technology Data Exchange (ETDEWEB)

    Natesan, K.; Majumdar, S.; Shankar, P. S.; Shah, V. N.; Nuclear Engineering Division

    2007-03-21

    In the coming decades, the United States and the entire world will need energy supplies to meet the growing demands due to population increase and increase in consumption due to global industrialization. One of the reactor system concepts, the Very High Temperature Reactor (VHTR), with helium as the coolant, has been identified as uniquely suited for producing hydrogen without consumption of fossil fuels or the emission of greenhouse gases [Generation IV 2002]. The U.S. Department of Energy (DOE) has selected this system for the Next Generation Nuclear Plant (NGNP) Project, to demonstrate emissions-free nuclear-assisted electricity and hydrogen production within the next 15 years. The NGNP reference concepts are helium-cooled, graphite-moderated, thermal neutron spectrum reactors with a design goal outlet helium temperature of {approx}1000 C [MacDonald et al. 2004]. The reactor core could be either a prismatic graphite block type core or a pebble bed core. The use of molten salt coolant, especially for the transfer of heat to hydrogen production, is also being considered. The NGNP is expected to produce both electricity and hydrogen. The process heat for hydrogen production will be transferred to the hydrogen plant through an intermediate heat exchanger (IHX). The basic technology for the NGNP has been established in the former high temperature gas reactor (HTGR) and demonstration plants (DRAGON, Peach Bottom, AVR, Fort St. Vrain, and THTR). In addition, the technologies for the NGNP are being advanced in the Gas Turbine-Modular Helium Reactor (GT-MHR) project, and the South African state utility ESKOM-sponsored project to develop the Pebble Bed Modular Reactor (PBMR). Furthermore, the Japanese HTTR and Chinese HTR-10 test reactors are demonstrating the feasibility of some of the planned components and materials. The proposed high operating temperatures in the VHTR place significant constraints on the choice of material selected for the reactor pressure vessel for

  7. The L-band PBMR measurements of surface soil moisture in FIFE. [First International satellite land surface climatology project Field Experiment

    Science.gov (United States)

    Wang, James R.; Shiue, James C.; Schmugge, Thomas J.; Engman, Edwin T.

    1990-01-01

    The NASA Langley Research Center's L-band pushbroom microwave radiometer (PBMR) aboard the NASA C-130 aircraft was used to map surface soil moisture at and around the Konza Prairie Natural Research Area in Kansas during the four intensive field campaigns of FIFE in May-October 1987. There was a total of 11 measurements was made when soils were known to be saturated. This measurement was used for the calibration of the vegetation effect on the microwave absorption. Based on this calibration, the data from other measurements on other days were inverted to generate the soil moisture maps. Good agreement was found when the estimated soil moisture values were compared to those independently measured on the ground at a number of widely separated locations. There was a slight bias between the estimated and measured values, the estimated soil moisture on the average being lower by about 1.8 percent. This small bias, however, was accounted for by the difference in time of the radiometric measurements and the soil moisture ground sampling.

  8. South Africa’s Technology Sector

    Science.gov (United States)

    2007-08-01

    Nuclear Energy Set to Increase,” Republic of South Africa, Pebble Bed Modular Reactor ( PBMR ), March 9, 2007, http://www.pbmr.co.za/. 38 David...Foresees Massive Expansion,” Republic of South Africa, Pebble Bed Modular Reactor ( PBMR ), March 5, 2007, http://www.pbmr.co.za/. 41 Sven Lunsche

  9. MAPA CONCEPTUAL PARA EL APRENDIZAJE BASADO EN PROBLEMAS

    OpenAIRE

    YURI GORBANEFF; ALEJANDRA CANCINO

    2009-01-01

    Se presentan los resultados del experimento sobre el uso de mapas conceptuales en el contexto del aprendizaje basado en problemas (ABP). El experimento fue realizado en la Universidad Javeriana (Bogotá, Colombia) en el pregrado de administración. Se encontró que el mapa conceptual mejora el aprendizaje pero no afecta la percepción de los alumnos del método de ABP. Se recomienda incluir mapas conceptuales en los ejercicios de ABP.

  10. MAPA CONCEPTUAL PARA EL APRENDIZAJE BASADO EN PROBLEMAS

    Directory of Open Access Journals (Sweden)

    YURI GORBANEFF

    2009-01-01

    Full Text Available Se presentan los resultados del experimento sobre el uso de mapas conceptuales en el contexto del aprendizaje basado en problemas (ABP. El experimento fue realizado en la Universidad Javeriana (Bogotá, Colombia en el pregrado de administración. Se encontró que el mapa conceptual mejora el aprendizaje pero no afecta la percepción de los alumnos del método de ABP. Se recomienda incluir mapas conceptuales en los ejercicios de ABP.

  11. Reactor Physics

    Energy Technology Data Exchange (ETDEWEB)

    Ait Abderrahim, A

    2001-04-01

    The Reactor Physics and MYRRHA Department of SCK-CEN offers expertise in various areas of reactor physics, in particular in neutronics calculations, reactor dosimetry, reactor operation, reactor safety and control and non-destructive analysis of reactor fuel. This expertise is applied in the Department's own research projects in the VENUS critical facility, in the BR1 reactor and in the MYRRHA project (this project aims at designing a prototype Accelerator Driven System). Available expertise is also used in programmes external to the Department such as the reactor pressure steel vessel programme, the BR2 reactor dosimetry, and the preparation and interpretation of irradiation experiments by means of neutron and gamma calculations. The activities of the Fuzzy Logic and Intelligent Technologies in Nuclear Science programme cover several domains outside the department. Progress and achievements in these topical areas in 2000 are summarised.

  12. Reactor safeguards

    CERN Document Server

    Russell, Charles R

    1962-01-01

    Reactor Safeguards provides information for all who are interested in the subject of reactor safeguards. Much of the material is descriptive although some sections are written for the engineer or physicist directly concerned with hazards analysis or site selection problems. The book opens with an introductory chapter on radiation hazards, the construction of nuclear reactors, safety issues, and the operation of nuclear reactors. This is followed by separate chapters that discuss radioactive materials, reactor kinetics, control and safety systems, containment, safety features for water reactor

  13. Reactor operation

    CERN Document Server

    Shaw, J

    2013-01-01

    Reactor Operation covers the theoretical aspects and design information of nuclear reactors. This book is composed of nine chapters that also consider their control, calibration, and experimentation.The opening chapters present the general problems of reactor operation and the principles of reactor control and operation. The succeeding chapters deal with the instrumentation, start-up, pre-commissioning, and physical experiments of nuclear reactors. The remaining chapters are devoted to the control rod calibrations and temperature coefficient measurements in the reactor. These chapters also exp

  14. Evaluating the control rod modelling approach used in the South African PBMR: comparison of VSOP calculations with ASTRA experiments

    Energy Technology Data Exchange (ETDEWEB)

    Reitsma, F. E-mail: reitsma@aec.co.za; Naidoo, D

    2003-06-01

    The problem of modelling a highly absorbing region in a diffusion calculation is well known and many methods have been developed to accommodate the transport effects in diffusion theory. In this work the use of the equivalent cross-sections method for pebble bed type reactors is evaluated by applying it to calculations of control rod (CR) experiments performed at the ASTRA Critical Facility at the Russian Research Centre, Kurchatov Institute in Moscow. The measured reactivity worths of the CRs situated in the side reflector are compared with the calculated values making use of equivalent diffusion parameters in VSOP. Results obtained were favourable for CRs situated within the first ring of reflector blocks, with larger errors obtained for CRs situated further from the core. An additional method that was investigated is the use of equivalent boron concentrations (EBCs) to represent the absorber region. This is shown to be useful if applied correctly and with care especially in the case of differential CR worth. Practical difficulties exist with both approaches, which makes the investigation of an alternative method, which should remove these shortcomings, attractive.

  15. Development of computational methods for the safety assessment of gas-cooled high-temperature and supercritical light-water reactors. Final report; Rechenmethoden zur Bewertung der Sicherheit von gasgekuehlten Hochtemperaturreaktoren und superkritischen Leichtwasserreaktoren. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Buchholz, S.; Cron, D. von der; Hristov, H.; Lerchl, G.; Papukchiev, A.; Seubert, A.; Sureda, A.; Weis, J.; Weyermann, F.

    2012-12-15

    This report documents developments and results in the frame of the project RS1191 ''Development of computational methods for the safety assessment of gas-cooled high temperature and supercritical light-water reactors''. The report is structured according to the five work packages: 1. Reactor physics modeling of gas-cooled high temperature reactors; 2. Coupling of reactor physics and 3-D thermal hydraulics for the core barrel; 3. Extension of ATHLET models for application to supercritical reactors (HPLWR); 4. Further development of ATHLET for application to HTR; 5. Further development and validation of ANSYS CFX for application to alternative reactor concepts. Chapter 4 describes the extensions made in TORT-TD related to the simulation of pebble-bed HTR, e.g. spectral zone buckling, Iodine-Xenon dynamics, nuclear decay heat calculation and extension of the cross section interpolation algorithms to higher dimensions. For fast running scoping calculations, a time-dependent 3-D diffusion solver has been implemented in TORT-TD. For the PBMR-268 and PBMR-400 as well as for the HTR-10 reactor, appropriate TORT-TD models have been developed. Few-group nuclear cross sections have been generated using the spectral codes MICROX- 2 and DRAGON4. For verification and validation of nuclear cross sections and deterministic reactor models, MCNP models of reactor core and control rod of the HTR-10 have been developed. Comparisons with experimental data have been performed for the HTR-10 first criticality and control rod worth. The development of the coupled 3-D neutron kinetics and thermal hydraulics code system TORT-TD/ATTICA3D is documented in chapter 5. Similar to the couplings with ATHLET and COBRA-TF, the ''internal'' coupling approach has been implemented. Regarding the review of experiments and benchmarks relevant to HTR for validation of the coupled code system, the PBMR-400 benchmarks and the HTR-10 test reactor have been selected

  16. Reactor Neutrinos

    OpenAIRE

    Soo-Bong Kim; Thierry Lasserre; Yifang Wang

    2013-01-01

    We review the status and the results of reactor neutrino experiments. Short-baseline experiments have provided the measurement of the reactor neutrino spectrum, and their interest has been recently revived by the discovery of the reactor antineutrino anomaly, a discrepancy between the reactor neutrino flux state of the art prediction and the measurements at baselines shorter than one kilometer. Middle and long-baseline oscillation experiments at Daya Bay, Double Chooz, and RENO provided very ...

  17. BOILING REACTORS

    Science.gov (United States)

    Untermyer, S.

    1962-04-10

    A boiling reactor having a reactivity which is reduced by an increase in the volume of vaporized coolant therein is described. In this system unvaporized liquid coolant is extracted from the reactor, heat is extracted therefrom, and it is returned to the reactor as sub-cooled liquid coolant. This reduces a portion of the coolant which includes vaporized coolant within the core assembly thereby enhancing the power output of the assembly and rendering the reactor substantially self-regulating. (AEC)

  18. SICOMPC: SIMULADOR PARA CONTROL PREDICTIVO BASADO EN MODELOS

    Directory of Open Access Journals (Sweden)

    ROBIN SALCEDO

    2008-01-01

    Full Text Available En este artículo se describe la herramienta computacional SICOMPC desarrollada con el fin de poder disponer de un programa para simulación de control predictivo basado en modelos. Si bien existen en el mercado algunos programas dedicados al control predictivo, ellos son en su mayoría costosos y de estructuracerrada. SICOMPC de otro lado tiene una estructura modular e incluye además ventanas donde se puede simular las estrategias clásicas de control, con el fin de compararlas bajo criterios de estabilidad y robustez en diversos modelos de plantas de procesos.

  19. Aprendizaje basado en problemas en ingeniería

    DEFF Research Database (Denmark)

    El aprendizaje basado en problemas y proyectos (PBL) ha ganado popularidad alrededor del mundo como una práctica educativa efectiva para desarrollar habilidades y competencias en los estudiantes. El PBL tiene modelos y prácticas diversas que se fundamentan en teorías de aprendizaje. En este libro...... aprendizaje con diferentes necesidades sociales y culturales. Este libro será una lectura clave para los académicos e investigadores que diseñan, implementan y ponen en práctica el PBL en cualquier sistema educativo. Descargar libro electrónico aquí...

  20. Métodos reactivos basados en campos potenciales para UAVs

    OpenAIRE

    Mera Prieto, Carmen

    2015-01-01

    Este trabajo presenta un método reactivo para evitar colisiones de vehículos aéreos no tripulados (Unmanned Aerial Vehicles, UAVs, en inglés) mofificando la trayectoria. El método reactivo implementado está basado en campos potenciales. El objetivo es que cualquier vehículo aéreo no tripulado (UAV) alcance las posiciones deseadas desde una posición de inicio y siguiendo un plan de vuelo, evitando las posibles colisiones con el entorno que se detecten durante el vuelo. Se ha rea...

  1. Deterministic and risk-informed approaches for safety analysis of advanced reactors: Part II, Risk-informed approaches

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Inn Seock, E-mail: innseockkim@gmail.co [ISSA Technology, 21318 Seneca Crossing Drive, Germantown, MD 20876 (United States); Ahn, Sang Kyu; Oh, Kyu Myung [Korea Institute of Nuclear Safety, 19 Kusong-dong, Yuseong-gu, Daejeon 305-338 (Korea, Republic of)

    2010-05-15

    Technical insights and findings from a critical review of deterministic approaches typically applied to ensure design safety of nuclear power plants were presented in the companion paper of Part I included in this issue. In this paper we discuss the risk-informed approaches that have been proposed to make a safety case for advanced reactors including Generation-IV reactors such as Modular High-Temperature Gas-cooled Reactor (MHTGR), Pebble Bed Modular Reactor (PBMR), or Sodium-cooled Fast Reactor (SFR). Also considered herein are a risk-informed safety analysis approach suggested by Westinghouse as a means to improve the conventional accident analysis, together with the Technology Neutral Framework recently developed by the US Nuclear Regulatory Commission as a high-level regulatory infrastructure for safety evaluation of any type of reactor design. The insights from a comparative review of various deterministic and risk-informed approaches could be usefully used in developing a new licensing architecture for enhanced safety of evolutionary or advanced plants.

  2. Membrane reactor. Membrane reactor

    Energy Technology Data Exchange (ETDEWEB)

    Shindo, Y.; Wakabayashi, K. (National Chemical Laboratory for Industry, Tsukuba (Japan))

    1990-08-05

    Many reaction examples were introduced of membrane reactor, to be on the point of forming a new region in the field of chemical technology. It is a reactor to exhibit excellent function, by its being installed with membrane therein, and is generally classified into catalyst function type and reaction promotion type. What firstly belongs to the former is stabilized zirconia, where oxygen, supplied to the cathodic side of membrane with voltage, impressed thereon, becomes O {sup 2 {minus}} to be diffused through the membrane and supplied, as variously activated oxygenous species, on the anodic side. Examples with many advantages can be given such as methane coupling, propylene oxidation, methanating reaction of carbon dioxide, etc. Apart, palladium film and naphion film also belong to the former. While examples of the latter comprise, among others, decomposition of hydrogen sulfide by porous glass film and dehydrogenation of cyclohexane or palladium alloy film, which are expected to be developed and materialized in the industry. 33 refs., 8 figs.

  3. Itinerarios de aprendizaje flexibles basados en mapas conceptuales

    Directory of Open Access Journals (Sweden)

    Olga Lucía Agudelo

    2015-07-01

    Full Text Available Se estudia el uso de itinerarios de aprendizaje  basados en mapas conceptuales como una propuesta para un diseño instruccional más flexible que potencie el aprendizaje y se centre en el estudiante, generando procesos no lineales, caracterizando sus elementos, estableciendo relaciones entre ellos y configurando un modelo general con especificaciones para  cada nivel de educación. Mediante una metodología construida sobre el modelo SAM (Successive Aproximation Model, se ha estudiado el proceso de diseño, implementación y evaluación de itinerarios de aprendizaje, en los que se representan en mapas conceptuales y de manera organizada y no lineal, conjuntos de actividades  que permiten el desarrollo de las competencias que deben comprenderse, dominarse y demostrarse. Los resultados obtenidos muestran la adecuación del itinerario de aprendizaje basado en mapas conceptuales a las características de los sujetos, resolviendo situaciones de la realidad mediante la construcción y creación de nuevos esquemas y formas de gestión del conocimiento, al mismo tiempo que aporta reflexión sobre los principios del diseño curricular utilizando TIC y genera autonomía en el proceso de aprendizaje.

  4. CFD Analysis of the Fuel Temperature in High Temperature Gas-Cooled Reactors

    Energy Technology Data Exchange (ETDEWEB)

    In, W. K.; Chun, T. H.; Lee, W. J.; Chang, J. H. [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    2005-07-01

    High temperature gas-cooled reactors (HTGR) have received a renewed interest as potential sources for future energy needs, particularly for a hydrogen production. Among the HTGRs, the pebble bed reactor (PBR) and a prismatic modular reactor (PMR) are considered as the nuclear heat source in Korea's nuclear hydrogen development and demonstration project. PBR uses coated fuel particles embedded in spherical graphite fuel pebbles. The fuel pebbles flow down through the core during an operation. PMR uses graphite fuel blocks which contain cylindrical fuel compacts consisting of the fuel particles. The fuel blocks also contain coolant passages and locations for absorber and control material. The maximum fuel temperature in the core hot spot is one of the important design parameters for both PBR and PMR. The objective of this study is to predict the fuel temperature distributions in PBR and PMR using a computational fluid dynamics(CFD) code, CFX-5. The reference reactor designs used in this analysis are PBMR400 and GT-MHR600.

  5. Multifunctional reactors

    NARCIS (Netherlands)

    Westerterp, K.R.

    1992-01-01

    Multifunctional reactors are single pieces of equipment in which, besides the reaction, other functions are carried out simultaneously. The other functions can be a heat, mass or momentum transfer operation and even another reaction. Multifunctional reactors are not new, but they have received much

  6. Energy Trends and Their Implications for U.S. Army Installations

    Science.gov (United States)

    2005-09-01

    Modular Reactor ( PBMR ) design. Gen- eral Atomics (GA) is moving forward with the GA Gas Turbine-Modular Helium Re- actor (GT-MHR) and Westinghouse is...working on the International Reactor Inher- ently Safe (IRIS) reactor design. The PBMR and GT-MHR are graphite-moderated, helium-cooled reactors with...load segment capacity may be better met by the smaller, modu- lar designs such as the GT-MHR or the PBMR . Assuming the PBMR design, pre- liminary

  7. Pebble bed reactor fuel cycle optimization using particle swarm algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Tavron, Barak, E-mail: btavron@bgu.ac.il [Planning, Development and Technology Division, Israel Electric Corporation Ltd., P.O. Box 10, Haifa 31000 (Israel); Shwageraus, Eugene, E-mail: es607@cam.ac.uk [Department of Engineering, University of Cambridge, Trumpington Street, Cambridge CB2 1PZ (United Kingdom)

    2016-10-15

    Highlights: • Particle swarm method has been developed for fuel cycle optimization of PBR reactor. • Results show uranium utilization low sensitivity to fuel and core design parameters. • Multi-zone fuel loading pattern leads to a small improvement in uranium utilization. • Thorium mixes with highly enriched uranium yields the best uranium utilization. - Abstract: Pebble bed reactors (PBR) features, such as robust thermo-mechanical fuel design and on-line continuous fueling, facilitate wide range of fuel cycle alternatives. A range off fuel pebble types, containing different amounts of fertile or fissile fuel material, may be loaded into the reactor core. Several fuel loading zones may be used since radial mixing of the pebbles was shown to be limited. This radial separation suggests the possibility to implement the “seed-blanket” concept for the utilization of fertile fuels such as thorium, and for enhancing reactor fuel utilization. In this study, the particle-swarm meta-heuristic evolutionary optimization method (PSO) has been used to find optimal fuel cycle design which yields the highest natural uranium utilization. The PSO method is known for solving efficiently complex problems with non-linear objective function, continuous or discrete parameters and complex constrains. The VSOP system of codes has been used for PBR fuel utilization calculations and MATLAB script has been used to implement the PSO algorithm. Optimization of PBR natural uranium utilization (NUU) has been carried out for 3000 MWth High Temperature Reactor design (HTR) operating on the Once Trough Then Out (OTTO) fuel management scheme, and for 400 MWth Pebble Bed Modular Reactor (PBMR) operating on the multi-pass (MEDUL) fuel management scheme. Results showed only a modest improvement in the NUU (<5%) over reference designs. Investigation of thorium fuel cases showed that the use of HEU in combination with thorium results in the most favorable reactor performance in terms of

  8. Reactor vessel

    OpenAIRE

    Makkee, M.; Kapteijn, F.; Moulijn, J.A

    1999-01-01

    A reactor vessel (1) comprises a reactor body (2) through which channels (3) are provided whose surface comprises longitudinal inwardly directed parts (4) and is provided with a catalyst (6), as well as buffer bodies (8, 12) connected to the channels (3) on both sides of the reactor body (2) and comprising connections for supplying (9, 10, 11) and discharging (13, 14, 15) via the channels (3) gases and/or liquids entering into a reaction with each other and substances formed upon this reactio...

  9. Very High Temperature Reactor (VHTR) Deep Burn Core and Fuel Analysis -- Complete Design Selection for the Pebble Bed Reactor

    Energy Technology Data Exchange (ETDEWEB)

    B. Boer; A. M. Ougouag

    2010-09-01

    The Deep-Burn (DB) concept focuses on the destruction of transuranic nuclides from used light water reactor fuel. These transuranic nuclides are incorporated into TRISO coated fuel particles and used in gas-cooled reactors with the aim of a fractional fuel burnup of 60 to 70% in fissions per initial metal atom (FIMA). This high performance is expected through the use of multiple recirculation passes of the fuel in pebble form without any physical or chemical changes between passes. In particular, the concept does not call for reprocessing of the fuel between passes. In principle, the DB pebble bed concept employs the same reactor designs as the presently envisioned low-enriched uranium core designs, such as the 400 MWth Pebble Bed Modular Reactor (PBMR-400). Although it has been shown in the previous Fiscal Year (2009) that a PuO2 fueled pebble bed reactor concept is viable, achieving a high fuel burnup, while remaining within safety-imposed prescribed operational limits for fuel temperature, power peaking and temperature reactivity feedback coefficients for the entire temperature range, is challenging. The presence of the isotopes 239-Pu, 240-Pu and 241-Pu that have resonances in the thermal energy range significantly modifies the neutron thermal energy spectrum as compared to a ”standard,” UO2-fueled core. Therefore, the DB pebble bed core exhibits a relatively hard neutron energy spectrum. However, regions within the pebble bed that are near the graphite reflectors experience a locally softer spectrum. This can lead to power and temperature peaking in these regions. Furthermore, a shift of the thermal energy spectrum with increasing temperature can lead to increased absorption in the resonances of the fissile Pu isotopes. This can lead to a positive temperature reactivity coefficient for the graphite moderator under certain operating conditions. The effort of this task in FY 2010 has focused on the optimization of the core to maximize the pebble discharge

  10. Chemical Reactors.

    Science.gov (United States)

    Kenney, C. N.

    1980-01-01

    Describes a course, including content, reading list, and presentation on chemical reactors at Cambridge University, England. A brief comparison of chemical engineering education between the United States and England is also given. (JN)

  11. Reactor Neutrinos

    Directory of Open Access Journals (Sweden)

    Soo-Bong Kim

    2013-01-01

    Full Text Available We review the status and the results of reactor neutrino experiments. Short-baseline experiments have provided the measurement of the reactor neutrino spectrum, and their interest has been recently revived by the discovery of the reactor antineutrino anomaly, a discrepancy between the reactor neutrino flux state of the art prediction and the measurements at baselines shorter than one kilometer. Middle and long-baseline oscillation experiments at Daya Bay, Double Chooz, and RENO provided very recently the most precise determination of the neutrino mixing angle θ13. This paper provides an overview of the upcoming experiments and of the projects under development, including the determination of the neutrino mass hierarchy and the possible use of neutrinos for society, for nonproliferation of nuclear materials, and geophysics.

  12. NUCLEAR REACTOR

    Science.gov (United States)

    Miller, H.I.; Smith, R.C.

    1958-01-21

    This patent relates to nuclear reactors of the type which use a liquid fuel, such as a solution of uranyl sulfate in ordinary water which acts as the moderator. The reactor is comprised of a spherical vessel having a diameter of about 12 inches substantially surrounded by a reflector of beryllium oxide. Conventionnl control rods and safety rods are operated in slots in the reflector outside the vessel to control the operation of the reactor. An additional means for increasing the safety factor of the reactor by raising the ratio of delayed neutrons to prompt neutrons, is provided and consists of a soluble sulfate salt of beryllium dissolved in the liquid fuel in the proper proportion to obtain the result desired.

  13. Reactor Engineering

    Science.gov (United States)

    Lema, Juan M.; López, Carmen; Eibes, Gemma; Taboada-Puig, Roberto; Moreira, M. Teresa; Feijoo, Gumersindo

    In this chapter, the engineering aspects of processes catalyzed by peroxidases will be presented. In particular, a discussion of the existing technologies that utilize peroxidases for different purposes, such as the removal of recalcitrant compounds or the synthesis of polymers, is analyzed. In the first section, the essential variables controlling the process will be investigated, not only those that are common in any enzymatic system but also those specific to peroxidative reactions. Next, different reactor configurations and operational modes will be proposed, emphasizing their suitability and unsuitability for different systems. Finally, two specific reactors will be described in detail: enzymatic membrane reactors and biphasic reactors. These configurations are especially valuable for the treatment of xenobiotics with high and poor water solubility, respectively.

  14. Reactor Neutrinos

    OpenAIRE

    Lasserre, T.; Sobel, H.W.

    2005-01-01

    We review the status and the results of reactor neutrino experiments, that toe the cutting edge of neutrino research. Short baseline experiments have provided the measurement of the reactor neutrino spectrum, and are still searching for important phenomena such as the neutrino magnetic moment. They could open the door to the measurement of coherent neutrino scattering in a near future. Middle and long baseline oscillation experiments at Chooz and KamLAND have played a relevant role in neutrin...

  15. Three-Dimensional Analysis of the Hot-Spot Fuel Temperature in Pebble Bed and Prismatic Modular Reactors

    Energy Technology Data Exchange (ETDEWEB)

    In, W. K.; Lee, S. W.; Lim, H. S.; Lee, W. J. [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    2006-07-01

    High temperature gas-cooled reactors(HTGR) have been reviewed as potential sources for future energy needs, particularly for a hydrogen production. Among the HTGRs, the pebble bed reactor(PBR) and a prismatic modular reactor(PMR) are considered as the nuclear heat source in Korea's nuclear hydrogen development and demonstration project. PBR uses coated fuel particles embedded in spherical graphite fuel pebbles. The fuel pebbles flow down through the core during an operation. PMR uses graphite fuel blocks which contain cylindrical fuel compacts consisting of the fuel particles. The fuel blocks also contain coolant passages and locations for absorber and control material. The maximum fuel temperature in the core hot spot is one of the important design parameters for both a PBR and a PMR. The objective of this study is to predict the hot-spot fuel temperature distributions in a PBR and a PMR at a steady state. The computational fluid dynamics(CFD) code, CFX-10 is used to perform the three-dimensional analysis. The latest design data was used here based on the reference reactor designs, PBMR400 and GTMHR60.

  16. hipermedia adaptativos educativos basados en estilos de aprendizaje

    Directory of Open Access Journals (Sweden)

    Helmut Leighton Álvarez

    2005-01-01

    Full Text Available Este trabajo es una propuesta metodológica para determinar atributos y métricas de calidad en sistemas hipermedia adaptativos educativos basados en estilos de aprendizaje, específicamente en los estilos activo, reflexivo, teórico y pragmático. Estos atributos y métricas están referidos únicamente a la interacción del usuario-estudiante con el sistema, es decir, desde la óptica puramente educativa y no desde el punto de vista de la herramienta informática como tal. Para ello comienza su análisis desde las características del estilo de aprendizaje y a partir de ellas se procede al establecimiento de los atributos de acuerdo a las estrategias instruccionales que le correspondan. Finalmente, se definen las métricas necesarias para cada uno de los atributos, estableciendo el o los tipos de variables que involucran, sus unidades de medida y escalas. De esta manera se desarrolla una metodología de cascada de determinación de atributos y métricas

  17. Aprendizaje basado en problemas aplicado a las lenguas de especialidad

    Directory of Open Access Journals (Sweden)

    Mª Ángeles Andreu-Andrés

    2010-04-01

    Full Text Available El ámbito universitario es un campo propicio para implementar el aprendizaje activo y el trabajo en equipo de los estudiantes de ingeniería, de modo que su práctica fomente la adquisición de destrezas y competencias que les sean útiles académica y profesionalmente. Una de estas técnicas de aprendizaje activo es el “Aprendizaje Basado en Problemas” (ABP. Si bien su uso se centra mayoritariamente en asignaturas de ciencias, este trabajo presenta parte de los resultados de una experiencia llevada a cabo dentro de una asignatura de inglés para fines académicos y profesionales. En ella, el ABP, el trabajo en equipo y la lengua de especialidad se entremezclan de manera natural con el pensamiento crítico, las presentaciones orales y la evaluación de la participación de cada miembro de los equipos a lo largo de las tareas que lo conforman. Los resultados que aquí se presentan ofrecen el producto diseñado y consensuado por los once grupos participantes para evaluar una presentación oral así como para autoevaluar y evaluar la participación de cada miembro de los equipos durante el proceso.

  18. APRENDIZAJE BASADO EN PROBLEMAS (ABP: UNA EXPERIENCIA PEDAGOGICA EN MEDICINA

    Directory of Open Access Journals (Sweden)

    Claudio Lermanda S.

    2007-01-01

    Full Text Available La enseñanza tradicional de la Medicina ha sido cuestionada por el avance tecnológico y el exponencial aumento de información médica accesible, obligando a reformular los curricula médicos bajo la mirada de las reformas educacionales que a escala global vienen desarrollándose desde el Proceso de Bolonia. Una propuesta curricular nueva señalada por Harden (1984 y conocida como modelo SPICES permite incorporar una metodología didáctica más apropiada para el proceso de enseñanza - aprendizaje formativo e integrador que demanda la sociedad actual. En este nuevo escenario, muchas Facultades de Medicina han incorporado el Aprendizaje Basado en Problemas (ABP como herramienta de aproximación al modelo señalado, por su carácter integrador de conocimientos, destrezas y actitudes que facilitan la adquisición de las competencias clínicas necesarias para el ejercicio profesional futuro. Este trabajo resume las consideraciones y sugerencias relativas al modelo y a la metodología tras una experiencia de dos años de ABP en la Facultad de Medicina de la Universidad Católica de la Santísima Concepción.

  19. DISEÑO DE SOFTWARE EDUCATIVO BASADO EN COMPETENCIAS

    Directory of Open Access Journals (Sweden)

    Manuel Fernando Caro Piñeres

    2009-01-01

    Full Text Available El presente artículo describe un modelo de diseño de software educativo basado en competencias, el cual presenta una visión integral del desarrollo de estas aplicaciones mediante la combinación de componentes pedagógicos, didácticos, multimediales y de ingeniería de software. El modelo sugerido se compone de cinco fases que detallan paso a paso los aspectos que se deben tener en cuenta para la creación de softwareeducativo. La fase inicial constituye la descripción del diseño educativo, en la cual se analiza la necesidad educativa, se plantean los objetivos de aprendizaje y se describen las competencias que se pretenden desarrollar con la aplicación; del diseño de éstas resultan las siguientes subfases: diseño de contenidos, diseño pedagógico y diseño de aprendizaje. Las competencias son el aspecto fundamental que abarca el desarrollo de este modelo, las cuales son primordiales para la realización de las fases a seguir conformadas por el diseño computacional y el diseño multimedial, estas se encargan del análisis y modelado del software, y del sistema de comunicación hombre-máquina. En la fase de producción se ensamblan los componentes elaborados o recolectados, según el caso. La última fase es la de aplicación, donde se hacen las pruebas de rigor para evaluar el desempeño del software en los contextos para los que fue desarrollado.

  20. Bioconversion reactor

    Science.gov (United States)

    McCarty, Perry L.; Bachmann, Andre

    1992-01-01

    A bioconversion reactor for the anaerobic fermentation of organic material. The bioconversion reactor comprises a shell enclosing a predetermined volume, an inlet port through which a liquid stream containing organic materials enters the shell, and an outlet port through which the stream exits the shell. A series of vertical and spaced-apart baffles are positioned within the shell to force the stream to flow under and over them as it passes from the inlet to the outlet port. The baffles present a barrier to the microorganisms within the shell causing them to rise and fall within the reactor but to move horizontally at a very slow rate. Treatment detention times of one day or less are possible.

  1. Preliminary Reactor Physics Assessment of the HTR Module with 14% Enriched UCO Fuel

    Energy Technology Data Exchange (ETDEWEB)

    Gerhard Strydom; Hans D. Gougar

    2013-03-01

    The high temperature reactor (HTR) Module (Lohnert, 1990) is a graphite-moderated, helium cooled pebble bed design that has been extensively used as a reference template for the former South African (Matzner, 2004) and current Chinese (Zhang et al., 2009) HTR programs. This design utilizes spherical fuel elements packed into a dynamic pebble bed, consisting of tri-structural isotropic (TRISO) coated uranium oxide (UO2) 500 µm fuel kernels with a U-235 enrichment of 7.8% and a heavy metal loading of 7 g per pebble. This fuel type was previously qualified for use in Germany for pebble bed HTRs, as well as undergoing re-qualification in South Africa for the PBMR project. It is also the fuel type being tested for use in the high temperature reactor (HTR-PM) under construction in China. In the United States, however, a different TRISO fuel form is the subject of a qualification program. The U.S. experience with HTRs has been focused upon the batch-fueled prismatic reactor in which TRISO particles are embedded in cylindrical compacts and stacked inside the graphite blocks which comprise the core. Under this type of operating regime, a smaller TRISO with a different composition and enrichment performs better than the fuel historically used in PBRs. Fuel kernels and compacting techniques more suited to prismatic core duty are currently being developed and qualified under the U.S. Department of Energy's Advanced Gas Reactor (AGR) fuel development program and in support of the Next Generation Nuclear Plant project. Interest in the pebble bed concept remains high, however, and a study was undertaken by the authors to assess the viability of using AGR fuel in a pebble bed reactor. Using the German HTR Module as the reference plant, key neutronic and thermal-hydraulic parameters were compared between the nominal design and one fueled with the fuel that is the focus of the AGR program.

  2. Sonochemical Reactors.

    Science.gov (United States)

    Gogate, Parag R; Patil, Pankaj N

    2016-10-01

    Sonochemical reactors are based on the generation of cavitational events using ultrasound and offer immense potential for the intensification of physical and chemical processing applications. The present work presents a critical analysis of the underlying mechanisms for intensification, available reactor configurations and overview of the different applications exploited successfully, though mostly at laboratory scales. Guidelines have also been presented for optimum selection of the important operating parameters (frequency and intensity of irradiation, temperature and liquid physicochemical properties) as well as the geometric parameters (type of reactor configuration and the number/position of the transducers) so as to maximize the process intensification benefits. The key areas for future work so as to transform the successful technique at laboratory/pilot scale into commercial technology have also been discussed. Overall, it has been established that there is immense potential for sonochemical reactors for process intensification leading to greener processing and economic benefits. Combined efforts from a wide range of disciplines such as material science, physics, chemistry and chemical engineers are required to harness the benefits at commercial scale operation.

  3. Extension of the reactor dynamics code MGT-3D for pebblebed and blocktype high-temperature-reactors

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Dunfu

    2015-07-01

    The High Temperature Gas cooled Reactor (HTGR) is an improved, gas cooled nuclear reactor. It was chosen as one of the candidates of generation IV nuclear plants [1]. The reactor can be shut down automatically because of the negative reactivity feedback due to the temperature's increasing in designed accidents. It is graphite moderated and Helium cooled. The residual heat can be transferred out of the reactor core by inactive ways as conduction, convection, and thermal radiation during the accident. In such a way, a fuel temperature does not go beyond a limit at which major fission product release begins. In this thesis, the coupled neutronics and fluid mechanics code MGT-3D used for the steady state and time-dependent simulation of HTGRs, is enhanced and validated [2]. The fluid mechanics part is validated by SANA experiments in steady state cases as well as transient cases. The fuel temperature calculation is optimized by solving the heat conduction equation of the coated particles. It is applied in the steady state and transient simulation of PBMR, and the results are compared to the simulation with the old overheating model. New approaches to calculate the temperature profile of the fuel element of block-type HTGRs, and the calculation of the homogeneous conductivity of composite materials are introduced. With these new developments, MGT-3D is able to simulate block-type HTGRs as well. This extended MGT-3D is used to simulate a cuboid ceramic block heating experiment in the NACOK-II facility. The extended MGT-3D is also applied to LOFC and DLOFC simulation of GT-MHR. It is a fluid mechanics calculation with a given heat source. This calculation result of MGT-3D is verified with the calculation results of other codes. The design of the Japanese HTTR is introduced. The deterministic simulation of the LOFC experiment of HTTR is conducted with the Monte-Carlo code Serpent and MGT-3D, which is the LOFC Project organized by OECD/NEA [3]. With Serpent the burnup

  4. PaRSys: Un nuevo modelo deformable interactivo basado en sistemas de partículas.

    OpenAIRE

    LÓPEZ ESCOBAR, ÓSCAR

    2008-01-01

    En esta tesis se ha presentado un nuevo modelo deformable (ParSys) que, al igual que otros modelos deformables, permite, de forma simple, la incorporación de elasticidad a los modelos geométricos sintéticos 3D. Este modelo, basado en volúmenes ligados, se ha centrado principalmente en la velocidad por encima de la precisión, aunque no se ha dejado de lado el comportamiento realista basado en parámetros físicos reales. ParSys ha intentado unir las ventajas de cada uno de los ...

  5. Sharp reduction in maximum fuel temperatures during loss of coolant accidents in a PBMR DPP-400 core, by means of optimised placement of neutron poisons

    Energy Technology Data Exchange (ETDEWEB)

    Serfontein, Dawid E., E-mail: Dawid.Serfontein@nwu.ac.za

    2014-05-01

    In a preceding study, coupled neutronics and thermo-hydraulic simulations were performed with the VSOP-A diffusion code for the standard 9.6 wt% enriched 9 g uranium fuel spheres in the 400 MWth Pebble Bed Modular Reactor Demonstration Power Plant. The axial power profile peaked at about a third from the top of the fuel core and the radial profile peaked directly adjacent to the central graphite reflector. The maximum temperature during a Depressurised Loss of Coolant (DLOFC) incident was 1581.0 °C, which is close to the limit of 1600 °C above which the leakage of radioactive fission products through the TRISO coatings around the fuel kernels may become unacceptable. This may present licensing challenges and also limits the total power output of the reactor. In this article the results of an optimisation study of the axial and radial power profiles for this reactor are reported. The main aim was to minimise the maximum DLOFC temperature. Reducing the maximum equilibrium temperature during normal operation was a lesser aim. Minimising the maximum DLOFC temperature was achieved by placing an optimised distribution of {sup 10}B neutron poison in the central reflector. The standard power profiles are sub-optimal with respect to the passive leakage of decay heat during a DLOFC. Since the radial power profile peaks directly adjacent to the central reflector, the distance that the decay heat needs to be conducted toward the outside of the reactor and the ultimate heat sink is at a maximum. The sharp axial power profile peak means that most of the decay power is concentrated in a small part of the core volume, thereby sharply increasing the required outward heat flux in this hotspot region. Both these features sharply increase the maximum DLOFC temperatures in this hotspot. Therefore the axial distribution of the neutron poisons in the central reflector was optimised so as to push the equilibrium power density profile radially outward and to suppress the axial power peak

  6. Control predictivo basado en modelo de un campo de colectores solares tipo acurex

    OpenAIRE

    Flor Unda, Omar Cristóbal

    2013-01-01

    El presente trabajo, presenta los resultados del control de un sistema de colectores solares tipo ACUREX, aplicando control predictivo basado en modelo como una técnica que aporta criterios para su estudio y mejoramiento. Se ha empleado el simulador creado para entorno Simulink, trabajo de (Camacho, et al., 1997).

  7. Hybrid adsorptive membrane reactor

    Science.gov (United States)

    Tsotsis, Theodore T. (Inventor); Sahimi, Muhammad (Inventor); Fayyaz-Najafi, Babak (Inventor); Harale, Aadesh (Inventor); Park, Byoung-Gi (Inventor); Liu, Paul K. T. (Inventor)

    2011-01-01

    A hybrid adsorbent-membrane reactor in which the chemical reaction, membrane separation, and product adsorption are coupled. Also disclosed are a dual-reactor apparatus and a process using the reactor or the apparatus.

  8. D and DR Reactors

    Data.gov (United States)

    Federal Laboratory Consortium — The world's second full-scale nuclear reactor was the D Reactor at Hanford which was built in the early 1940's and went operational in December of 1944.D Reactor ran...

  9. Hybrid adsorptive membrane reactor

    Science.gov (United States)

    Tsotsis, Theodore T.; Sahimi, Muhammad; Fayyaz-Najafi, Babak; Harale, Aadesh; Park, Byoung-Gi; Liu, Paul K. T.

    2011-03-01

    A hybrid adsorbent-membrane reactor in which the chemical reaction, membrane separation, and product adsorption are coupled. Also disclosed are a dual-reactor apparatus and a process using the reactor or the apparatus.

  10. Nuclear reactor neutron shielding

    Energy Technology Data Exchange (ETDEWEB)

    Speaker, Daniel P; Neeley, Gary W; Inman, James B

    2017-09-12

    A nuclear reactor includes a reactor pressure vessel and a nuclear reactor core comprising fissile material disposed in a lower portion of the reactor pressure vessel. The lower portion of the reactor pressure vessel is disposed in a reactor cavity. An annular neutron stop is located at an elevation above the uppermost elevation of the nuclear reactor core. The annular neutron stop comprises neutron absorbing material filling an annular gap between the reactor pressure vessel and the wall of the reactor cavity. The annular neutron stop may comprise an outer neutron stop ring attached to the wall of the reactor cavity, and an inner neutron stop ring attached to the reactor pressure vessel. An excore instrument guide tube penetrates through the annular neutron stop, and a neutron plug comprising neutron absorbing material is disposed in the tube at the penetration through the neutron stop.

  11. Reactor and method of operation

    Science.gov (United States)

    Wheeler, John A.

    1976-08-10

    A nuclear reactor having a flattened reactor activity curve across the reactor includes fuel extending over a lesser portion of the fuel channels in the central portion of the reactor than in the remainder of the reactor.

  12. Stress Analysis of Coated Particle Fuel in the Deep-Burn Pebble Bed Reactor Design

    Energy Technology Data Exchange (ETDEWEB)

    B. Boer; A. M. Ougouag

    2010-05-01

    High fuel temperatures and resulting fuel particle coating stresses can be expected in a Pu and minor actinide fueled Pebble Bed Modular Reactor (400 MWth) design as compared to the ’standard’ UO2 fueled core. The high discharge burnup aimed for in this Deep-Burn design results in increased power and temperature peaking in the pebble bed near the inner and outer reflector. Furthermore, the pebble power in a multi-pass in-core pebble recycling scheme is relatively high for pebbles that make their first core pass. This might result in an increase of the mechanical failure of the coatings, which serve as the containment of radioactive fission products in the PBMR design. To investigate the integrity of the particle fuel coatings as a function of the irradiation time (i.e. burnup), core position and during a Loss Of Forced Cooling (LOFC) incident the PArticle STress Analysis code (PASTA) has been coupled to the PEBBED code for neutronics, thermal-hydraulics and depletion analysis of the core. Two deep burn fuel types (Pu with or without initial MA fuel content) have been investigated with the new code system for normal and transient conditions including the effect of the statistical variation of thickness of the coating layers.

  13. Evaluacion del impacto del aprendizaje basado en proyectos en cursos de ingenieria utilizando analisis de correspondencias multiples

    National Research Council Canada - National Science Library

    Fernandez-Samaca, Liliana; Ramirez, Jose M; Vasquez, Jesus E

    2013-01-01

    Este articulo presenta una experiencia sobre la evaluacion del impacto del aprendizaje basado en proyectos en cursos de ingenieria mediante el uso de analisis de correspondencias multiples y agrupacion jerarquica...

  14. Modelo de Sistema Basado en Conocimiento en el Dominio de la Seguridad de Aplicaciones

    Directory of Open Access Journals (Sweden)

    María Victoria Bajarlía

    2013-12-01

    Full Text Available El objetivo es proponer un modelo de un sistema basado en conocimiento (SBC aplicado al análisis de seguridad de aplicaciones de gestión. El modelo se fundamenta en un sistema basado en conocimiento (SBC que cuenta con un componente cognitivo que le permite incorporar conocimiento. En virtud de que las amenazas y los ataques informáticos representan un problema constante y creciente se puede suponer que el SBC, a través del aprendizaje dinámico que lo mantendrá actualizado, podrá asistir a los especialistas en Seguridad de la Información, en el área de competencia, a la elaboración de Especificación de Requerimientos.

  15. Opiniones de los estudiantes de enfermería sobre el aprendizaje basado en problemas

    OpenAIRE

    Guerra Martín, María Dolores

    2009-01-01

    Desde el curso 2005/2006 el Departamento de Enfermería (Universidad de Sevilla) ha fomentado la implantación de la estrategia de Aprendizaje Basado en Problemas (ABP), en la Diplomatura de Enfermería. En este trabajo presentamos la experiencia del ABP, en la asignatura de Administración de Servicios de Enfermería, en la Unidad Docente Valme, durante el curso 2007/2008.

  16. La centración en problemas de probabilidad basados en el razonamiento proporcional

    OpenAIRE

    Ramírez, Greivin; Ballestero, Esteban

    2007-01-01

    Este documento reporta los resultados de un estudio exploratorio aplicado a estudiantes de secundaria que presentan problemas de equiprobabilidad y centración en ejercicios de probabilidad basados en el razonamiento proporcional. Los problemas propuestos a los estudiantes han sido analizados por Green, Papinni, Fischbein y Gazit en investigaciones previas, de esta manera, nuestro aporte consiste en proponer una extensión a los resultados obtenidos por estos autores a partir de marco conceptua...

  17. Estado actual y perspectivas del enfoque basados en competencias dentro de las ciencias de la salud

    OpenAIRE

    2009-01-01

    El presente texto establece una aproximación teórica alrededor del enfoque basado en competencias (EBC) dentro de la formación de los profesionales en ciencias de la salud y su posibilidad de mejoramiento en sus procesos de enseñanza y aprendizaje. Así mismo, permite reconocer los avances y las experiencias en la implementación del modelo educativo por competencias.

  18. Reactor Physics Programme

    Energy Technology Data Exchange (ETDEWEB)

    De Raedt, C

    2000-07-01

    The Reactor Physics and Department of SCK-CEN offers expertise in various areas of reactor physics, in particular in neutronics calculations, reactor dosimetry, reactor operation, reactor safety and control and non-destructive analysis on reactor fuel. This expertise is applied within the Reactor Physics and MYRRHA Research Department's own research projects in the VENUS critical facility, in the BR1 reactor and in the MYRRHA project (this project aims at designing a prototype Accelerator Driven System). Available expertise is also used in programmes external to the Department such as the reactor pressure steel vessel programme, the BR2 reactor dosimetry, and the preparation and interpretation of irradiation experiments. Progress and achievements in 1999 in the following areas are reported on: (1) investigations on the use of military plutonium in commercial power reactors; (2) neutron and gamma calculations performed for BR-2 and for other reactors; (3) the updating of neutron and gamma cross-section libraries; (4) the implementation of reactor codes; (6) the management of the UNIX workstations; and (6) fuel cycle studies.

  19. Attrition reactor system

    Science.gov (United States)

    Scott, Charles D.; Davison, Brian H.

    1993-01-01

    A reactor vessel for reacting a solid particulate with a liquid reactant has a centrifugal pump in circulatory flow communication with the reactor vessel for providing particulate attrition, resulting in additional fresh surface where the reaction can occur.

  20. LMFBR type reactor

    Energy Technology Data Exchange (ETDEWEB)

    Kawakami, Hiroto

    1995-02-07

    A reactor container of the present invention has a structure that the reactor container is entirely at the same temperature as that at the inlet of the reactor and, a hot pool is incorporated therein, and the reactor container has is entirely at the same temperature and has substantially uniform temperature follow-up property transiently. Namely, if the temperature at the inlet of the reactor core changes, the temperature of the entire reactor container changes following this change, but no great temperature gradient is caused in the axial direction and no great heat stresses due to axial temperature distribution is caused. Occurrence of thermal stresses caused by the axial temperature distribution can be suppressed to improve the reliability of the reactor container. In addition, since the laying of the reactor inlet pipelines over the inside of the reactor is eliminated, the reactor container is made compact and the heat shielding structures above the reactor and a protection structure of container walls are simplified. Further, secondary coolants are filled to the outside of the reactor container to simplify the shieldings. The combined effects described above can improve economical property and reliability. (N.H.).

  1. Modelo integral de sistemas de sujeción basados en pinzas expansibles

    OpenAIRE

    2012-01-01

    El dispositivo de amarre de propósito general más versátil es el porta-pinzas, muy frecuentemente utilizado en fresado, torneado, taladrado e inspección. Los porta-pinzas deben alcanzar elevadas velocidades de rotación, manteniendo, simultáneamente, una alta precisión rotacional. El porta-pinzas, básicamente, es un mecanismo basado en el efecto cuña, donde la mayoría de ellos emplean anillos, con ranuras finas, hechos de acero templado y rectificado con altos grados de precisión, denominados ...

  2. Análisis de encuestas basado en diseño y modelos muestrales

    OpenAIRE

    Liseras, Natacha

    2003-01-01

    En el presente trabajo se comparan dos métodos de análisis de encuestas: inferencia basada en diseño muestral (inferencia clásica) e inferencia basada en modelos, para el caso específico de datos binarios correlacionados. Se propone la formulación de modelos marginales y de modelos mixtos basados en la función de verosimilitud completa. Se efectúa una aplicación concreta a un estudio de corte transversal en el cual la dependencia entre las observaciones se debe al submuestreo de unidades prim...

  3. Planeamiento estrategico basado en tecnologia orientada a objetos con aplicacion a ingenieria de informacion

    OpenAIRE

    2001-01-01

    Hoy en día las empresas observan como cuatro paradigmas impactan el negocio, estos paradigmas son: el nuevo ambiente de negocio, la nueva empresa, el nuevo orden geopolítico y la nueva tecnología, es por ello, que es necesario contar con un método que permita establecer la dirección estratégica de negocio integrado a los sistemas de información y la cultura organizacional, obteniendo como beneficio una empresa basado en el conocimiento. En el mercado se encuentran métodos de planeamiento ...

  4. Compuestos cruciformes y polímeros dendronizados basados en bitiofeno y fenilenvinileno

    OpenAIRE

    García Rodríguez, Eva Amaranda

    2013-01-01

    En esta Tesis Doctoral se presenta la síntesis y caracterización de compuestos cruciformes (primera parte) y polímeros dendronizados (segunda parte), basados en bitiofeno y fenilenvinileno, así como el estudio de las propiedades optoelectrónicas de algunos de ellos. Dentro de los compuestos orgánicos con un alto grado de conjugación destacan los compuestos con estructura cruciforme, los cuales ofrecen la posibilidad de situar sus orbitales frontera HOMO y LUMO en distintas zonas de la mol...

  5. Detección de fraude con modelos basados en agentes: las elecciones mexicanas de 2006

    OpenAIRE

    Gonzalo Castañeda; Ignacio Ibarra

    2010-01-01

    En este artículo se desarrolla una técnica novedosa para la detección de fraudes electorales a partir del análisis estadístico de los resultados. Con este fin se describe un modelo computacional basado en agentes en el que la dinámica de una campaña electoral condiciona las preferencias partidistas de los individuos. El modelo se construye suponiendo que en un proceso limpio los resultados oficiales dependen, esencialmente, de preferencias partidistas que han sido sujetas a la interacción soc...

  6. Modelos basados en el individuo y la plataforma NetLogo

    OpenAIRE

    Ginovart Gisbert, Marta; Portell Canal, Xavier; Ferrer-Closas, Pol; Blanco Abellán, Mónica

    2011-01-01

    El objetivo general de este trabajo se enmarca en el deseo de dar a conocer la metodología de la modelización basada en el individuo y sus posibilidades para ser utilizada, entre otras metodologías, en la adquisición de la competencia de modelización en docencia. Para ello se presenta: i) una descripción de los elementos que permiten identificar, describir, comunicar e implementar los modelos basados en el individuo (IBMs), y como obtener resultados de simulación; y ii) un ejemplo-mu...

  7. Un modelo de recuperación de información basado en SVMs

    Directory of Open Access Journals (Sweden)

    M. Fernanda Maldonado

    2004-01-01

    Full Text Available Los clasificadores como los SVMs (Support Vector Machines se usaron para la clasificación de documentos de manera muy eficiente, pero su utilidad no ha sido comprobada para la recuperación de información (RI en el momento de jerarquerizar los documentos. En este artículo proponemos una transformación que asocia el proceso de la RI a un nuevo espacio vectorial en el que un clasificador basado en SVMs se entrena para aprender el concepto de similitud frente a los documentos.

  8. Mantenimiento industrial basado en la gestión del conocimiento

    OpenAIRE

    Cárcel Carrasco, Francisco Javier

    2014-01-01

    El mantenimiento industrial requiere de conocimientos técnicos muy específicos, normalmente almacenados de manera tácita entre el personal que opera en estas áreas. Mediante la reseña sobre dos libros de investigación, en este artículo se muestra el nivel estratégico que para las empresas con activos físicos supone una adecuada gestión del conocimiento en la ingeniería del mantenimiento industrial. Cárcel Carrasco, FJ. (2014). Mantenimiento industrial basado en la gestión del conocimiento....

  9. Open Ensis FSM : Aparato señalador de esgrima basado en LPC1769

    OpenAIRE

    2013-01-01

    Este proyecto desarrolla un aparato señalizador de esgrima o FSM (un dispositivo electrónico capaz de determinar si el arma de un esgrimista ha tocado la superficie válida del otro deportista en las condiciones de tiempo preestablecidas por el reglamento de esgrima), basado en la placa LPC1769 que permite la integración con un software de control remoto mediante un módulo WiFly RN-XV. Aquest projecte desenvolupa un aparell senyalitzador d'esgrima o FSM (un dispositiu electrònic capaç de de...

  10. Control predictivo basado en modelo no lineal por modo dual viable

    OpenAIRE

    Ramírez Pérez, Kelly

    2011-01-01

    En esta investigación se propone un Control Predictivo Basado en Modelo no Lineal(NMPC) por modo dual con estabilidad garantizada, el cual usa un controlador PI dentrode la región terminal. En la formulación de esta estrategia de control, para el cálculo de la región terminal (Ω) y del dominio de atracción se usa la teoría de conjuntos invariantes y un algoritmo aleatorizado del tipo Montecarlo. En la estrategia de conmutación NMPC al PI se restringen los elementos finales de control suavi...

  11. Aprendizaje basado en problemas: Metodología de aprendizaje centrada en el estudiante

    OpenAIRE

    V. Tórtora

    2013-01-01

    8vas Jornadas de la Sociedad de Bioquímica y Biología Molecular. 12 y 13 de setiembre 2013. SIMPOSIO VI: “Educación en Ciencias” Coordinadores: María Noel Álvarez, Andrea MedeirosLa reforma del plan de estudios de la carrera de Doctor en Medicina implicó, entre outras modificaciones, la incorporación de nuevas metodologías de enseñanza y aprendizaje. Una de ellas es la de “aprendizaje basado en problemas” (ABP), que se caracteriza por colocar al estudiante en el centro del proceso de aprendi...

  12. Gobernanza de las organizaciones de salud basados en atención primaria de salud

    OpenAIRE

    Báscolo, Ernesto

    2012-01-01

    Se desarrolla un marco analítico para explicar las condiciones de efectividad de diferentes estrategias que promueven sistemas integrados de servicios de salud basados en atención primaria de la salud (APS) en América Latina. Con una pers­pectiva de economía política, se caracterizan diferentes modos de gobernanza (clan, incentivos y jerárquicos) para representar alternativas formas de regulación que  promueven innovaciones en organización de la provisión de los servicios. Se presentan condic...

  13. El enfoque educativo basado en competencias, un reto que enfrenta la Universidad Veracruzana

    OpenAIRE

    2012-01-01

    Este artículo tiene como propósito compartir la experiencia que ha tenido la Universidad Veracruzana en la promoción e implementación del enfoque educativo basado en competencias. La incorporación obedece a la demanda internacional de formar profesionistas competentes en los ámbitos profesional, personal y social.Una de las acciones relevantes ha sido la capacitación de su personal docente y la implementación de una estrategia denominada Proyecto Aula. Este proyecto va dirigido a sistematizar...

  14. Modelo basado en competencias en la educación superior. Reflexiones e interrogantes

    OpenAIRE

    2014-01-01

    Este trabajo presenta algunas reflexiones surgidas en torno al modelo educativo basado en competencias en el marco del CAI+D 2009 denominado Educación y trabajo. El caso de los alumnos que abandonan los estudios superiores. A tales efectos se indaga acerca de los orígenes históricos y culturales de la utilización de este enfoque en el ámbito de la educación superior, partiendo de la Declaración de Bolonia del año 1999, y del análisis de los modos en que este enfoque se operativizó (Proyecto T...

  15. Control de inventarios aplicado a empresas comerciales basado en el Coso Erm

    OpenAIRE

    Alvear Zamora, Gladys Elizabeth

    2014-01-01

    Esta investigación tiene como objetivo realizar el control de inventarios de tres empresas comerciales de tipo familiar basado en el COSO ERM, esta es una herramienta que nos ayudará a detectar riesgos de fraude, robo y pedidos excesivos de productos. A su vez, se analizará la eficiencia del manejo del control de inventarios, por medio de los métodos o procedimientos para la toma de los mismos, sus saldos de inventarios (valores máximos y mínimos), porcentajes de ventas, ratios financieros qu...

  16. Sistema de apoyo para el aprendizaje de las matemáticas basado en Web

    OpenAIRE

    Santiago-Acosta, Rubén D.; Delgado-Cepeda, Francisco; Quezada-Batalla, Lourdes

    2013-01-01

    En este trabajo se presenta el desarrollo, construcción e implementación de un sistema de apoyo para el aprendizaje de las matemáticas basado en Web. El sistema se construyó utilizando los paquetes Mathematica, MatJax y LaTeX mediante pequeños programas modulares que permiten elaborar tutoriales, prácticas y tareas. Se utiliza Google-Drive como base de un sistema de evaluación en línea permitiendo que el profesor realice análisis estadísticos sobre los resultados de los estudiantes. Las unida...

  17. Control predictivo basado en modelo no lineal por modo dual viable

    OpenAIRE

    Ramírez Pérez, Kelly

    2011-01-01

    En esta investigación se propone un Control Predictivo Basado en Modelo no Lineal(NMPC) por modo dual con estabilidad garantizada, el cual usa un controlador PI dentrode la región terminal. En la formulación de esta estrategia de control, para el cálculo de la región terminal (Ω) y del dominio de atracción se usa la teoría de conjuntos invariantes y un algoritmo aleatorizado del tipo Montecarlo. En la estrategia de conmutación NMPC al PI se restringen los elementos finales de control suavi...

  18. Enfoque basado en distancias de algunos métodos estadísticos multivariantes

    OpenAIRE

    Fortiana Gregori, Josep

    2001-01-01

    1) IntroducciónUna de las aplicaciones estadísticas de la Geometría Métrica es la representación de conjuntos, consistente en determinar puntos en un espacio de métrica conocida (frecuentemente euclídea) cuyas distancias reproduzcan exacta o aproximadamente las observadas.Los Métodos de Regresión y Discriminación basados en Distancias, propuestos por Cuadras, proporcionan predicciones estadísticas aplicando propiedades geométricas de una representación euclídea. Tienen la ventaja de permitir ...

  19. Mantenimiento industrial basado en la gestión del conocimiento

    OpenAIRE

    Cárcel Carrasco, Francisco Javier

    2014-01-01

    El mantenimiento industrial requiere de conocimientos técnicos muy específicos, normalmente almacenados de manera tácita entre el personal que opera en estas áreas. Mediante la reseña sobre dos libros de investigación, en este artículo se muestra el nivel estratégico que para las empresas con activos físicos supone una adecuada gestión del conocimiento en la ingeniería del mantenimiento industrial. Cárcel Carrasco, FJ. (2014). Mantenimiento industrial basado en la gestión del conocimiento....

  20. Materiales moleculares basados en calcogenuros clúster de metales del grupo 6 con especies electroactivas

    OpenAIRE

    Triguero Bascuñán, Sonia

    2008-01-01

    Esta tesis presenta el uso de nuevos complejos [Mo3S7L3]2-, en el que L es un ligando electroquímicamente activo (ditioleno, diselenoleno o dioxoleno), como precursores para la preparación de semiconductores multifuncionales unimoleculares basados en unidades clúster magnéticas. Se han investigado las propiedades redox de estos clústeres dianiónicos y se han determinado sus estructuras cristalinas mediante difracción de rayos x en monocristal, así como calculado sus estructuras electrónicas ...

  1. Open Ensis FSM : Aparato señalador de esgrima basado en LPC1769

    OpenAIRE

    Fortis Urbano, Julio

    2013-01-01

    Este proyecto desarrolla un aparato señalizador de esgrima o FSM (un dispositivo electrónico capaz de determinar si el arma de un esgrimista ha tocado la superficie válida del otro deportista en las condiciones de tiempo preestablecidas por el reglamento de esgrima), basado en la placa LPC1769 que permite la integración con un software de control remoto mediante un módulo WiFly RN-XV. Aquest projecte desenvolupa un aparell senyalitzador d'esgrima o FSM (un dispositiu electrònic capaç de de...

  2. Vectores recombinantes basados en el virus Vaccinia modificado de Ankara (MVA) como vacunas contra la leishmaniasis

    OpenAIRE

    Pérez Jiménez, Eva; Larraga, Vicente; Esteban, Mariano

    2005-01-01

    Vectores recombinantes basados en el virus vaccinia modificado de Ankara (MVA) como vacunas contra la leishmaniasis. Los vectores de la invención contienen secuencias codificantes de la proteína LACK, preferentemente insertadas en el locus de hemaglutinina del virus y bajo el control de un promotor que permite su expresión a lo largo del ciclo de infección del virus. Son vectores seguros, estables, que dan lugar a una potente respuesta inmune que confiere protección frente a la leishmaniasis,...

  3. Una experiencia de aprendizaje basado en proyecto en una asignatura de robótica

    OpenAIRE

    2006-01-01

    En este trabajo se presenta una experiencia concreta de introducción de la metodología de aprendizaje basado en proyecto (ABP) en una asignatura de robótica de quinto curso de la titulación de Ingeniero en informática de la UEM. La introducción del ABP ha sido de forma parcial y solo afecta a la parte práctica de la asignatura. Nuestro enfoque se apoya en la propuesta de un solo proyecto para toda la clase, donde los objetivos marcados no se limitan al desarrollo técnico del pr...

  4. Light water reactor safety

    CERN Document Server

    Pershagen, B

    2013-01-01

    This book describes the principles and practices of reactor safety as applied to the design, regulation and operation of light water reactors, combining a historical approach with an up-to-date account of the safety, technology and operating experience of both pressurized water reactors and boiling water reactors. The introductory chapters set out the basic facts upon which the safety of light water reactors depend. The central section is devoted to the methods and results of safety analysis. The accidents at Three Mile Island and Chernobyl are reviewed and their implications for light wate

  5. Nuclear reactor physics

    CERN Document Server

    Stacey, Weston M

    2010-01-01

    Nuclear reactor physics is the core discipline of nuclear engineering. Nuclear reactors now account for a significant portion of the electrical power generated worldwide, and new power reactors with improved fuel cycles are being developed. At the same time, the past few decades have seen an ever-increasing number of industrial, medical, military, and research applications for nuclear reactors. The second edition of this successful comprehensive textbook and reference on basic and advanced nuclear reactor physics has been completely updated, revised and enlarged to include the latest developme

  6. Army Logistician. Volume 33, Issue 5, September-October 2001

    Science.gov (United States)

    2001-10-01

    envisioned for the energy depot. One proposed design is the pebble bed modular reactor ( PBMR ) being developed by Eskom in South Africa. Westinghouse...uplink. The technology of both the PBMR and the RS–MHR features small, modular, helium-cooled reactors pow- ered by ceramic-coated fuel particles that...reactors. The PBMR , coupled with a direct-cycle gas turbine generator, would have a ther- mal efficiency of about 42 to 45 percent and would pro- duce

  7. Spinning fluids reactor

    Science.gov (United States)

    Miller, Jan D; Hupka, Jan; Aranowski, Robert

    2012-11-20

    A spinning fluids reactor, includes a reactor body (24) having a circular cross-section and a fluid contactor screen (26) within the reactor body (24). The fluid contactor screen (26) having a plurality of apertures and a circular cross-section concentric with the reactor body (24) for a length thus forming an inner volume (28) bound by the fluid contactor screen (26) and an outer volume (30) bound by the reactor body (24) and the fluid contactor screen (26). A primary inlet (20) can be operatively connected to the reactor body (24) and can be configured to produce flow-through first spinning flow of a first fluid within the inner volume (28). A secondary inlet (22) can similarly be operatively connected to the reactor body (24) and can be configured to produce a second flow of a second fluid within the outer volume (30) which is optionally spinning.

  8. Simulacion borrosa de un reactor con reaccion exotermica no lineal

    Directory of Open Access Journals (Sweden)

    MIGUEL ANGEL RODRIGUEZ BORROTO

    2007-01-01

    Full Text Available En el presente trabajo se desarrolla un modelo difuso basado en la estructura Takagi-Sugeno-Kang dinámica para un reactor continuo de tanque con agitador (RCTA con reacción química de primer orden exotérmico. A partir de datos experimentales obtenidos mediante simulación del proceso real, se obtiene la base de datos de las variables de entrada y salida del proceso y a partir de la misma se elaboran los archivos de datos de entrenamiento y de verificación del modelo borroso el cual es obtenido mediante la herramienta anfis de MATLAB. El modelo obtenido permite predecir la salida del sistema con errores de predicción muy bajos, por lo que el mismo sienta las bases para el diseño de un controlador predictivo no lineal del mismo en próximas etapas de la investigación

  9. Reactor Vessel Surveillance Program for Advanced Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Kyeong-Hoon; Kim, Tae-Wan; Lee, Gyu-Mahn; Kim, Jong-Wook; Park, Keun-Bae; Kim, Keung-Koo

    2008-10-15

    This report provides the design requirements of an integral type reactor vessel surveillance program for an integral type reactor in accordance with the requirements of Korean MEST (Ministry of Education, Science and Technology Development) Notice 2008-18. This report covers the requirements for the design of surveillance capsule assemblies including their test specimens, test block materials, handling tools, and monitors of the surveillance capsule neutron fluence and temperature. In addition, this report provides design requirements for the program for irradiation surveillance of reactor vessel materials, a layout of specimens and monitors in the surveillance capsule, procedures of installation and retrieval of the surveillance capsule assemblies, and the layout of the surveillance capsule assemblies in the reactor.

  10. MODELO CONCEPTUAL DE UN PROYECTO DE SOFTWARE UTILIZANDO EL RAZONAMIENTO BASADO EN CASOS

    Directory of Open Access Journals (Sweden)

    Martha Delgado Dapena

    2002-10-01

    Full Text Available

    Este trabajo tiene por objetivo aprovechar el conocimiento acumulado por los diseñadores (proyectistas de software en nuevos proyectos, utilizando el razonamiento basado en casos (RBC, para obtener un modelo conceptual de UML (lenguaje de modelación unificado partiendo de una lista de requerimientos candidatos definidos por los analistas. Con esta información, de carácter preliminar, los grupos de desarrollo pueden simplificar de manera notable algunos aspectos de las fases de modelación iniciales que permitan aprovechar el trabajo y las experiencias previas y aceleren por vías probadas el proceso total de elaboración de software. En este trabajo se describen las características generales del funcionamiento de un sistema que se desarrolla en el Centro de Estudios de Ingeniería de Sistemas (CEIS, que aborda estos temas de la ingeniería de software, utilizando la técnica de inteligencia artificial de razonamiento basado en casos.

  11. ¿Qué pueden ofrecer los modelos basados en agentes vivos en el contexto docente?

    Directory of Open Access Journals (Sweden)

    Marta Ginovart Gisbert

    2015-07-01

    Full Text Available Los sistemas biológicos o sistemas formados por entidades vivas (individuos son sistemas complejos, tanto por la “complejidad” que cada individuo o agente vivo tiene, como por las posibles relaciones que se pueden establecer entre ellos, así como por las posibles relaciones con el entorno o medioambiente en el que estos individuos se desarrollan, viven, compiten y mueren, y que por tanto, modifican como resultado de sus acciones. Este trabajo se basa en la experiencia acumulada en los últimos años en el uso de modelos basados en agentes en el ámbito de los biosistemas en la Universidad Politècnica de Catalunya. El objetivo es ofrecer elementos de estudio y discusión para poder responder a las siguientes preguntas: 1 ¿Qué son los modelos basados en agentes vivos?, 2 ¿Cómo se puede trabajar con estos modelos computacionales en el aula?, y 3 ¿Qué pueden ofrecer estos modelos en un entorno educativo? Asimismo, se proporciona información y referencias específicas para facilitar la incorporación de este tipo de modelo en planes de estudios con diferentes niveles de instrucción matemática y biológica, como complemento a otras metodologías de modelización.

  12. SNTP program reactor design

    Science.gov (United States)

    Walton, Lewis A.; Sapyta, Joseph J.

    1993-06-01

    The Space Nuclear Thermal Propulsion (SNTP) program is evaluating the feasibility of a particle bed reactor for a high-performance nuclear thermal rocket engine. Reactors operating between 500 MW and 2,000 MW will produce engine thrusts ranging from 20,000 pounds to 80,000 pounds. The optimum reactor arrangement depends on the power level desired and the intended application. The key components of the reactor have been developed and are being tested. Flow-to-power matching considerations dominate the thermal-hydraulic design of the reactor. Optimal propellant management during decay heat cooling requires a three-pronged approach. Adequate computational methods exist to perform the neutronics analysis of the reactor core. These methods have been benchmarked to critical experiment data.

  13. Hybrid reactors. [Fuel cycle

    Energy Technology Data Exchange (ETDEWEB)

    Moir, R.W.

    1980-09-09

    The rationale for hybrid fusion-fission reactors is the production of fissile fuel for fission reactors. A new class of reactor, the fission-suppressed hybrid promises unusually good safety features as well as the ability to support 25 light-water reactors of the same nuclear power rating, or even more high-conversion-ratio reactors such as the heavy-water type. One 4000-MW nuclear hybrid can produce 7200 kg of /sup 233/U per year. To obtain good economics, injector efficiency times plasma gain (eta/sub i/Q) should be greater than 2, the wall load should be greater than 1 MW.m/sup -2/, and the hybrid should cost less than 6 times the cost of a light-water reactor. Introduction rates for the fission-suppressed hybrid are usually rapid.

  14. Fast Spectrum Reactors

    CERN Document Server

    Todd, Donald; Tsvetkov, Pavel

    2012-01-01

    Fast Spectrum Reactors presents a detailed overview of world-wide technology contributing to the development of fast spectrum reactors. With a unique focus on the capabilities of fast spectrum reactors to address nuclear waste transmutation issues, in addition to the well-known capabilities of breeding new fuel, this volume describes how fast spectrum reactors contribute to the wide application of nuclear power systems to serve the global nuclear renaissance while minimizing nuclear proliferation concerns. Readers will find an introduction to the sustainable development of nuclear energy and the role of fast reactors, in addition to an economic analysis of nuclear reactors. A section devoted to neutronics offers the current trends in nuclear design, such as performance parameters and the optimization of advanced power systems. The latest findings on fuel management, partitioning and transmutation include the physics, efficiency and strategies of transmutation, homogeneous and heterogeneous recycling, in addit...

  15. LMFBR type reactor

    Energy Technology Data Exchange (ETDEWEB)

    Kanbe, Mitsuru

    1997-04-04

    An LMFBR type reactor comprises a plurality of reactor cores in a reactor container. Namely, a plurality of pot containing vessels are disposed in the reactor vessel and a plurality of reactor cores are formed in a state where an integrated-type fuel assembly is each inserted to a pot, and a coolant pipeline is connected to each of the pot containing-vessel to cool the reactor core respectively. When fuels are exchanged, the integrated-type fuel assembly is taken out together with the pot from the reactor vessel in a state where the integrated-type fuel assembly is immersed in the coolants in the pot as it is. Accordingly, coolants are supplied to each of the pot containing-vessel connected with the coolant pipeline and circulate while cooling the integrated-type fuel assembly for every pot. Then, when the fuels are exchanged, the integrated type fuel assembly is taken out to the outside of the reactor together with the pot by taking up the pot from the pot-containing vessel. Then, neutron economy is improved to thereby improve reactor power and the breeding ratio. (N.H.)

  16. INVAP's Research Reactor Designs

    Directory of Open Access Journals (Sweden)

    Eduardo Villarino

    2011-01-01

    Full Text Available INVAP, an Argentine company founded more than three decades ago, is today recognized as one of the leaders within the research reactor industry. INVAP has participated in several projects covering a wide range of facilities, designed in accordance with the requirements of our different clients. For complying with these requirements, INVAP developed special skills and capabilities to deal with different fuel assemblies, different core cooling systems, and different reactor layouts. This paper summarizes the general features and utilization of several INVAP research reactor designs, from subcritical and critical assemblies to high-power reactors.

  17. Multi purpose research reactor

    Energy Technology Data Exchange (ETDEWEB)

    Raina, V.K. [Research Reactor Design and Projects Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)]. E-mail: vkrain@magnum.barc.ernet.in; Sasidharan, K. [Research Reactor Design and Projects Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Sengupta, Samiran [Research Reactor Design and Projects Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Singh, Tej [Research Reactor Services Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)

    2006-04-15

    At present Dhruva and Cirus reactors provide the majority of research reactor based facilities to cater to the various needs of a vast pool of researchers in the field of material sciences, physics, chemistry, bio sciences, research and development work for nuclear power plants and production of radio isotopes. With a view to further consolidate and expand the scope of research and development in nuclear and allied sciences, a new 20 MWt multi purpose research reactor is being designed. This paper describes some of the design features and safety aspects of this reactor.

  18. Solucionando dificultades en el aula: una estrategia usando el aprendizaje basado en problemas

    Directory of Open Access Journals (Sweden)

    Mery Luz Valderrama Sanabria

    2017-09-01

    Full Text Available Introducción: Se utiliza el proyecto de investigación en el aula con énfasis en el Aprendizaje Basado en Problemas, el cual promueve el aprendizaje activo y significativo, permitiendo solucionar situaciones reales de conocimiento en torno a una temática específica. Implementa los principios de la investigación formativa, como herramienta para generar nuevas alternativas en la apropiación del conocimiento. Este estudio tuvo como objetivo conocer la percepción de los estudiantes del programa Regencia de Farmacia frente a la utilización del aprendizaje basado en problemas con el fin de realizar aportes al currículo. Materiales y Métodos: Estudio descriptivo y transversal realizado con una muestra no probabilística, por conveniencia, conformada por 109 estudiantes de segundo a sexto semestre. Se elaboró un cuestionario con escala tipo Likert, sometido a valoración por expertos. Resultados: En general, los estudiantes están de acuerdo con la estrategia porque ha permitido acercarse a la investigación, fortaleciendo el pensamiento crítico; generando autonomía y responsabilidad frente al aprendizaje. A medida que avanzan los semestres, le ven mayor utilidad. Sin embargo, falta claridad en el uso de la metodología y capacitación por parte de algunos docentes para desarrollarla eficazmente. Discusión: La coordinación docente es fundamental, se debe fortalecer este aspecto para dar claridad al uso de la metodología. Implementar procesos de evaluación para determinar los avances desarrollados por los estudiantes y el impacto generado. Conclusiones: Los estudiantes consideran que adquieren conocimientos y competencias que les ayudarán en la práctica profesional.  Cómo citar este artículo: Valderrama ML, Castaño GA. Solucionando dificultades en el aula: una estrategia usando el aprendizaje basado en problemas. Rev Cuid. 2017; 8(3: 1907-18. http://dx.doi.org/10.15649/cuidarte.v8i3.456

  19. Modelo de control de gestión para la empresa SERVIFACONZA basados en indicadores financieros y no financieros

    OpenAIRE

    Llerena Sevilla, Paúl Damián

    2011-01-01

    En la realización del presente trabajo de plan de tesis sobre el tema: “Modelo de Control de Gestión para la empresa SERVIFACONZA, basado en indicadores financieros y no financieros”, mi persona se ha propuesto analizar los principales aspectos (indicadores financieros y no financieros) y componentes (perspectivas) de la herramienta de gestión.

  20. Mantenimiento Correctivo Aplicado a un Sitio Basado en Joomla. Una Propuesta Centrada en la Accesibilidad

    Directory of Open Access Journals (Sweden)

    Daiana E. Casaro Pedro L. Alfonzo

    2015-05-01

    Full Text Available Se presenta una experiencia de personalización de un sitio basado en un sistema gestor de contenidos de libre distribución o CMS, atendiendo su amplia aplicabilidad en la Industria del Software y el Sector de Servicios Informáticos. Dado que un CMS puede ser mejorado por la comunidad de desarrolladores, se considera al mantenimiento correctivo como parte integral del ciclo de vida de desarrollo del software. En este trabajo, se abordan los estándares propuestos por el Consorcio W3C que permiten el acceso a los contenidos web y la verificación del cumplimiento de las pautas WCAG 2.0, durante el proceso de desarrollo del sitio web.

  1. Perfiles de personas con diferencia mental basados en las funciones motrices gruesas

    Directory of Open Access Journals (Sweden)

    Isabel Ma. Ferrándiz Vindel

    2002-01-01

    Full Text Available El propósito de este estudio ha sido identificar posibles subtipos de alumnos con Deficiencia Mental basados en funciones motrices gruesas. Se seleccionó un grupo de alumnos de un centro específico de Deficiencia Mental, que no presentaron deficiencias motóricas asociadas, y se les administraron los subtests de motricidad gruesa del «Test Bruininks-Ozeretsky para medir la eficacia motriz»- Los cuatro subtipos resultantes mostraron diferentes perfiles de desarrollo motor A partir de estos resultados, se recomienda diseñar programas específicos que intenten paliar los trastornos motrices gruesos, analizados para cada uno de los subtipos hallados, y realizar adaptaciones curriculares pertinentes, teniendo en cuenta los perfiles motrices estudiados

  2. CONTROL BASADO EN OPTIMIZACIÓN DE UN SECADOR ROTATORIO DIRECTO

    Directory of Open Access Journals (Sweden)

    HÉCTOR VALDÉS-GONZÁLEZ

    2012-01-01

    Full Text Available Este trabajo presenta el control de un secador rotatorio directo basado en optimización no lineal. Esta metodología permite auto-sintonizar dinámicamente un controlador PI o PID, mejorando claramente el control del proceso respecto de la sintonización clásica. El control del proceso se realiza a través de simulación computacional vía Matlab y su verificación a través de un proceso piloto, lo que permite apreciar la potencialidad de la sintonía dinámica que se propone. Los resultados, tiempo de respuesta y dinámica de control posibilitan que investigación futura pueda escalar esta propuesta desde el laboratorio a procesos industriales.

  3. Modelado del indice de precios al consumidor usando un modelo hibrido basado en redes neuronales artificiales

    Directory of Open Access Journals (Sweden)

    JUAN DAVID VELÁSQUEZ HENAO

    2005-01-01

    Full Text Available Un nuevo modelo híbrido es propuesto para pronosticar el índice colombiano de precios al consumidor. Este es basado en una descomposición estructural de la serie temporal con el objetivo de remover cualquier patrón fácilmente detectable en los datos, y en el uso de un perceptron multicapa para modelar las relaciones ocultas en la serie de tiempo. Los resultados superan las aproximaciones clásicas basadas en la aproximación de Box y Jenkins, y los modelos convencionales de Redes Neuronales, e incentivan el estudio de este tipo de aproximación híbrida para modelar otras series temporales.

  4. Aprendizaje basado en problemas y proyectos en espacios híbridos: Nomadas y Artesanos

    DEFF Research Database (Denmark)

    Ryberg, Thomas; Davidsen, Jacob; Hodgson, Vivien

    2017-01-01

    grupal a largo plazo, basado en problemas y proyectos. A partir de entrevistas, talleres y observaciones de las prácticas grupales reales de los estudiantes dentro de espacios abiertos, compartidos y flexibles en la Universidad de Aalborg (AAU), identificaremos y discutiremos cómo los estudiantes...... diferentes lugares y artefactos a lo largo del tiempo. Por lo tanto, sostenemos que ”la creación de lugar" es una práctica importante en relación con ’las acciones de aprendizaje en red" de los estudiantes, que impacta sobre el tipo y la naturaleza de la colaboración que se lleva a cabo...

  5. Modelos de Requisitos Basados en I* para Detectar Proactividad en Dashboards

    Directory of Open Access Journals (Sweden)

    Alain Pérez-Acosta

    2014-06-01

    Full Text Available El objetivo del trabajo es presentar modelos para la captura de los requisitos de un dashboard para detectar un comportamiento proactivo. Estos modelos siguen un enfoque orientado hacia metas y fueron creados con el marco de trabajo i*, que toma como base las premisas del modelado social. Para detectar el comportamiento proactivo se usaron patrones basados en modelos de i* para detectar proactividad en la etapa de requisitos de un sistema de software. Los modelos que se obtienen como resultado del trabajo tienen representados los actores, metas, intenciones, tareas y recursos que se necesitan para modelar los requisitos de un dashboard con un comportamiento proactivo y pueden, además, ser utilizados en distintos contextos de negocio.

  6. Valoración del profesorado de magisterio sobre el aprendizaje basado en competencias implantado

    Directory of Open Access Journals (Sweden)

    Aurelio Villa

    2013-01-01

    Full Text Available A partir del curso académico 2010 - 11 se ha iniciado en Europa de modo oficial el Espacio Europeo de Educación Superior (EEES, y con él la puesta en marcha de las denominadas titulaciones Bolonia bajo la etiqueta del crédito europeo (European Credit Transf er System, ECTS. Este artículo trata de presentar el nivel de desarrollo del aprendizaje basado en competencias de las titulaciones de magisterio en España. A través de una metodología denominada Análisis Importancia - Realización (AIR (Martilla, J.A. y J ames, J.L., 1977 con la que se pretende dibujar la valoración que el profesorado y responsables académicos de magisterio realizan sobre el aprendizaje basado en competencias (ABC, y extraer las principales conclusiones del estudio empírico llevado a cabo en una muestra de 145 personas (profesores y gestores. Se presentan los resultados de un análisis factorial con cinco factores que describen el proceso de enseñanza - aprendizaje: planificación de competencias, gestión pedagógica, coordinación docente, tut oría y evaluación, y finalmente, revisión y mejora. Estos factores se correlacionaron con la formación recibida para iniciar el EEES y con el uso de la lección magistral. Obteniendo ambas variables correlaciones significativas. Este artículo se enriquece con otro artículo complementario que recoge la perspectiva cualitativa del profesorado sobre su visión de la implementación del proceso europeo y sus dificultades.

  7. Aprendizaje basado en la resolución de problemas: una experiencia práctica

    Directory of Open Access Journals (Sweden)

    E. González-López

    Full Text Available El aprendizaje basado en la resolución de problemas incorpora herramientas metodológicas capaces de facilitar la consecución de los objetivos propuestos para la formación de los futuros médicos dentro del marco de la docencia universitaria en el Espacio Europeo de Educación Superior. Promueve una formación más activa, flexible y práctica, que concede mayor protagonismo al trabajo personal tutorizado (aprendizaje autodirigido, en detrimento de las clásicas clases teóricas, eminentemente expositivas, en las que el papel del estudiante es, en general, más pasivo. La Unidad de Medicina de Familia de la Universidad Autónoma de Madrid incorporó el aprendizaje basado en la resolución de problemas en el desarrollo de la asignatura optativa 'Atención Primaria y Medicina de Familia', ofertada como optativa a los alumnos de segundo ciclo de licenciatura (cursos 4.º a 6.º desde el curso 2005-2006. Intentamos con ella promover la formación de médicos capaces de aprender y mantener su competencia durante toda su vida profesional, no sólo en lo referido a la adquisición/integración de conocimientos científicos suficientes, sino también en cuanto al desarrollo de las habilidades necesarias para su adecuada aplicación práctica considerando a cada paciente de modo integral como realidad biopsicosocial, en un contexto sanitario definido, sin olvidar los aspectos bioéticos implícitos al quehacer del médico (respeto hacia el paciente y compromiso social. Revisamos en este artículo el diseño práctico de la asignatura.

  8. SELECCIÓN DE NUEVOS GENOTIPOS DE ARROZ BASADOS EN LA PROBABILIDAD DE SUPERAR AL TESTIGO

    Directory of Open Access Journals (Sweden)

    Ismael Camargo-Buitrago

    2014-01-01

    Full Text Available El objetivo de este trabajo fue validar una metodología estadística para estimar la confiabilidad o respuesta normalizada (RN i y la esta - bilidad de cuatro genotipos elite de arroz, en comparación con el testigo IDIAP 145-05. Se utilizó la base de datos del proyecto de mejoramiento genético de arroz del IDIAP, proveniente de los experimentos realizados entre el 2009 y 2011, en 31 ambientes bajo condiciones de secano. Los resultados del estudio permitieron verificar que los nuevos genotipos superaron significativamente (P<0,05 en rendi - miento al testigo. Los cuatro genotipos IDIAP FL 106-11, IDIAP FL 137-11, IDIAP FL 155, e IDIAP FL 156 presen - taron una confiablidad promedio de 0,79; 0,75; 0,75 y 0,74, respectivamente. La probabilidad normalizada del IDIAP FL 106-11 representó una respuesta diferencial en rendimiento mayor que cero con respecto al IDIAP 145-05, en ocho de cada diez casos. La confiabilidad estuvo relacionada con los parámetros de estabilidad basados en modelos de regresión (b i y S 2 di . El modelo multivariado AMMI, considerando el PCA1, identificó el genotipo IDIAP FL 156, como el más estable. El modelo Biplot GGE, basado en el PCA2, indicó que el genotipo IDIAP FL 155, tuvo mayor estabilidad. La confiabilidad o respuesta normalizada, puede ser útil para hacer recomendaciones más precisas para la utilización de los nuevos genotipos a nivel comercial

  9. El currículo basado en competencias profesionales integradas en la universidad ecuatoriana

    Directory of Open Access Journals (Sweden)

    Floralba del Rocío Aguilar Gordón

    2017-01-01

    Full Text Available El artículo reflexiona acerca del currículo basado en competencias profesionales integradas en las carreras de educación de la universidad ecuatoriana, analiza los principios y fundamentos que orientan al quehacer educativo representado por una diversidad de concepciones ideológicas, antropológicas, sociológicas, epistemológicas, pedagógicas y psicológicas en las que se concretizan. Consta de cuatro partes: En la primera parte, presenta los antecedentes del tema desarrollado; aborda los principales problemas, necesidades de los contextos y objetivos; determina las tendencias de desarrollo local y regional incluidas en los campos de estudio; plantea los principales requerimientos de la sociedad ecuatoriana. En la segunda parte, analiza los principios generales que rigen el currículo en base a competencias profesionales, se refiere a los campos de formación del currículo; a los niveles de organización curricular; a los núcleos básicos de las disciplinas que sustentan la profesión. En la tercera parte, reflexiona acerca de la planificación curricular por competencias; revisa las orientaciones del conocimiento y los saberes que tiene en cuenta la construcción del objeto de estudio de la profesión. En la cuarta parte, presenta algunas contribuciones del currículo basado en competencias profesionales integradas para la formación profesional y para la formación del talento humano.

  10. Reactor Materials Research

    Energy Technology Data Exchange (ETDEWEB)

    Van Walle, E

    2001-04-01

    The activities of the Reactor Materials Research Department of the Belgian Nuclear Research Centre SCK-CEN in 2000 are summarised. The programmes within the department are focussed on studies concerning (1) fusion, in particular mechanical testing; (2) Irradiation Assisted Stress Corrosion Cracking (IASCC); (3) nuclear fuel; and (4) Reactor Pressure Vessel Steel (RPVS)

  11. Space Nuclear Reactor Engineering

    Energy Technology Data Exchange (ETDEWEB)

    Poston, David Irvin [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-03-06

    We needed to find a space reactor concept that could be attractive to NASA for flight and proven with a rapid turnaround, low-cost nuclear test. Heat-pipe-cooled reactors coupled to Stirling engines long identified as the easiest path to near-term, low-cost concept.

  12. Light water reactor program

    Energy Technology Data Exchange (ETDEWEB)

    Franks, S.M.

    1994-12-31

    The US Department of Energy`s Light Water Reactor Program is outlined. The scope of the program consists of: design certification of evolutionary plants; design, development, and design certification of simplified passive plants; first-of-a-kind engineering to achieve commercial standardization; plant lifetime improvement; and advanced reactor severe accident program. These program activities of the Office of Nuclear Energy are discussed.

  13. Status of French reactors

    Energy Technology Data Exchange (ETDEWEB)

    Ballagny, A. [Commissariat a l`Energie Atomique, Saclay (France)

    1997-08-01

    The status of French reactors is reviewed. The ORPHEE and RHF reactors can not be operated with a LEU fuel which would be limited to 4.8 g U/cm{sup 3}. The OSIRIS reactor has already been converted to LEU. It will use U{sub 3}Si{sub 2} as soon as its present stock of UO{sub 2} fuel is used up, at the end of 1994. The decision to close down the SILOE reactor in the near future is not propitious for the start of a conversion process. The REX 2000 reactor, which is expected to be commissioned in 2005, will use LEU (except if the fast neutrons core option is selected). Concerning the end of the HEU fuel cycle, the best option is reprocessing followed by conversion of the reprocessed uranium to LEU.

  14. Nuclear reactor design

    CERN Document Server

    2014-01-01

    This book focuses on core design and methods for design and analysis. It is based on advances made in nuclear power utilization and computational methods over the past 40 years, covering core design of boiling water reactors and pressurized water reactors, as well as fast reactors and high-temperature gas-cooled reactors. The objectives of this book are to help graduate and advanced undergraduate students to understand core design and analysis, and to serve as a background reference for engineers actively working in light water reactors. Methodologies for core design and analysis, together with physical descriptions, are emphasized. The book also covers coupled thermal hydraulic core calculations, plant dynamics, and safety analysis, allowing readers to understand core design in relation to plant control and safety.

  15. Mirror reactor surface study

    Energy Technology Data Exchange (ETDEWEB)

    Hunt, A. L.; Damm, C. C.; Futch, A. H.; Hiskes, J. R.; Meisenheimer, R. G.; Moir, R. W.; Simonen, T. C.; Stallard, B. W.; Taylor, C. E.

    1976-09-01

    A general survey is presented of surface-related phenomena associated with the following mirror reactor elements: plasma first wall, ion sources, neutral beams, director converters, vacuum systems, and plasma diagnostics. A discussion of surface phenomena in possible abnormal reactor operation is included. Several studies which appear to merit immediate attention and which are essential to the development of mirror reactors are abstracted from the list of recommended areas for surface work. The appendix contains a discussion of the fundamentals of particle/surface interactions. The interactions surveyed are backscattering, thermal desorption, sputtering, diffusion, particle ranges in solids, and surface spectroscopic methods. A bibliography lists references in a number of categories pertinent to mirror reactors. Several complete published and unpublished reports on surface aspects of current mirror plasma experiments and reactor developments are also included.

  16. Study of indicators aggregation techniques for the selection of a new nuclear reactor for Mexico; Estudio de tecnicas de agregacion de indicadores para la seleccion de un nuevo reactor nuclear para Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Barragan M, A.M.; Martin del Campo M, C. [UNAM, Facultad de Ingenieria, 04510 Mexico D.F. (Mexico)]. e-mail: ale_bar_m@yahoo.com.mx

    2007-07-01

    A study on several aggregation techniques that can be used as multi criteria analysis methods, like important part of the methodology developed for the selection of a nuclear reactor for Mexico is described. In an arbitrary way three reactors were selected to be compared, these they are the AP1000 (Advance Passive from 1000 MWe), the PBMR (Pebble Bed Modular Reactor) and the GT-MHR (Gas Turbine Modular Helium). The evaluation approaches were classified in three categories: Economic, Socio-political and of safety and environment. In each category they were defined the more important evaluation indicators and then it was built a matrix with those values of each reactor. The four studied aggregation methods are described: Normalization, Linear deliberation, Fuzzy Logic and AHP (Analytic Hierarchy Process). The well-known aggregation mechanisms are those that are obtained of the lineal deliberation and of the normalization, which have demonstrated to give good results before the simplicity of their use. The fuzzy logic has the advantage that it allows to manage qualitative and quantitative information simultaneously without the aggregation problems that are presented since in a conventional system the semantic pattern on that is based, it is provided by the theory of the diffuse groups that has demonstrated in other areas of the knowledge a better approach to the reality, when admitting that the nature has shades and that the decisions take in function of a wide range of possibilities and of approaches in contradictory occasions or in conflict, all equally worth. The Analytic Hierarchical Process (AHP) that consists in formalizing the intuitive understanding of a multi criteria complex problem, by means of the construction of a hierarchical model that allows the decision agent to structure the problem in visual form, giving him the form of a hierarchy of attributes (global objective of the problem, approaches and alternative). Finally, using the matrix of initiators

  17. The IAEA Coordinated Research Program on HTGR Reactor Physics, Thermal-hydraulics and Depletion Uncertainty Analysis: Description of the Benchmark Test Cases and Phases

    Energy Technology Data Exchange (ETDEWEB)

    Frederik Reitsma; Gerhard Strydom; Bismark Tyobeka; Kostadin Ivanov

    2012-10-01

    The continued development of High Temperature Gas Cooled Reactors (HTGRs) requires verification of design and safety features with reliable high fidelity physics models and robust, efficient, and accurate codes. The uncertainties in the HTR analysis tools are today typically assessed with sensitivity analysis and then a few important input uncertainties (typically based on a PIRT process) are varied in the analysis to find a spread in the parameter of importance. However, one wish to apply a more fundamental approach to determine the predictive capability and accuracies of coupled neutronics/thermal-hydraulics and depletion simulations used for reactor design and safety assessment. Today there is a broader acceptance of the use of uncertainty analysis even in safety studies and it has been accepted by regulators in some cases to replace the traditional conservative analysis. Finally, there is also a renewed focus in supplying reliable covariance data (nuclear data uncertainties) that can then be used in uncertainty methods. Uncertainty and sensitivity studies are therefore becoming an essential component of any significant effort in data and simulation improvement. In order to address uncertainty in analysis and methods in the HTGR community the IAEA launched a Coordinated Research Project (CRP) on the HTGR Uncertainty Analysis in Modelling early in 2012. The project is built on the experience of the OECD/NEA Light Water Reactor (LWR) Uncertainty Analysis in Best-Estimate Modelling (UAM) benchmark activity, but focuses specifically on the peculiarities of HTGR designs and its simulation requirements. Two benchmark problems were defined with the prismatic type design represented by the MHTGR-350 design from General Atomics (GA) while a 250 MW modular pebble bed design, similar to the INET (China) and indirect-cycle PBMR (South Africa) designs are also included. In the paper more detail on the benchmark cases, the different specific phases and tasks and the latest

  18. Reactivity considerations for the on-line refuelling of a pebble bed modular reactor-Illustrating safety for the most reactive core fuel load

    Energy Technology Data Exchange (ETDEWEB)

    Reitsma, Frederik, E-mail: Frederik.Reitsma@pbmr.co.za [Pebble Bed Modular Reactor (Pty) Ltd., PO Box 9396, Centurion 0043 (South Africa)

    2012-10-15

    In the multi-pass fuel management scheme employed for the pebble bed modular reactor the fuel pebbles are re-circulated until they reach the target burn-up. The rate at which fresh fuel is loaded and burned fuel is discharged is a result of the core neutronics cycle analysis but in practice (on the plant) this has to be controlled and managed by the fuel handling and storage system and use of the burnup measurement system. The excess reactivity is the additional reactivity available in the core during operating conditions that is the result of loading a fuel mixture in the core that is more reactive (less burned) than what is required to keep the reactor critical at full power operational conditions. The excess reactivity is balanced by the insertion of the control rods to keep the reactor critical. The excess reactivity allows flexibility in operations, for example to overcome the xenon build up when power is decreased as part of load follow. In order to limit reactivity excursions and to ensure safe shutdown the excess reactivity and thus the insertion depth of the control rods at normal operating conditions has to be managed. One way to do this is by operational procedures. The reactivity effect of long-term operation with the control rods inserted deeper than the design point is investigated and a control rod insertion limit is proposed that will not limit normal operations. The effects of other phenomena that can increase the power defect, such as higher-than-expected fuel temperatures, are also introduced. All of these cases are then evaluated by ensuring cold shutdown is still achievable and where appropriate by reactivity insertion accident analysis. These aspects are investigated on the PBMR 400 MW design.

  19. Slurry reactor design studies

    Energy Technology Data Exchange (ETDEWEB)

    Fox, J.M.; Degen, B.D.; Cady, G.; Deslate, F.D.; Summers, R.L. (Bechtel Group, Inc., San Francisco, CA (USA)); Akgerman, A. (Texas A and M Univ., College Station, TX (USA)); Smith, J.M. (California Univ., Davis, CA (USA))

    1990-06-01

    The objective of these studies was to perform a realistic evaluation of the relative costs of tublar-fixed-bed and slurry reactors for methanol, mixed alcohols and Fischer-Tropsch syntheses under conditions where they would realistically be expected to operate. The slurry Fischer-Tropsch reactor was, therefore, operated at low H{sub 2}/CO ratio on gas directly from a Shell gasifier. The fixed-bed reactor was operated on 2.0 H{sub 2}/CO ratio gas after adjustment by shift and CO{sub 2} removal. Every attempt was made to give each reactor the benefit of its optimum design condition and correlations were developed to extend the models beyond the range of the experimental pilot plant data. For the methanol design, comparisons were made for a recycle plant with high methanol yield, this being the standard design condition. It is recognized that this is not necessarily the optimum application for the slurry reactor, which is being proposed for a once-through operation, coproducing methanol and power. Consideration is also given to the applicability of the slurry reactor to mixed alcohols, based on conditions provided by Lurgi for an Octamix{trademark} plant using their standard tubular-fixed reactor technology. 7 figs., 26 tabs.

  20. Una adaptación del Proceso Unificado de Desarrollo para la creación de portales basados en Joomla

    Directory of Open Access Journals (Sweden)

    Enrique José Leyva Miranda

    2006-01-01

    Full Text Available Presenta una adaptación del Proceso Unificado (UP para la creación de portales basados en Joomla, un sistema de gestión de contenidos (CMS de código libre con características de plataforma para desarrollo de portales basado en componentes. En la modelación del proceso se ha empleado SPEM, un estándar basado en UML propuesto por el "Object Management Group" (OMG. Se proponen y describen cinco disciplinas e igual número de roles que se consideran adecuados a las características de este tipo de proyecto.

  1. Fast Breeder Reactor studies

    Energy Technology Data Exchange (ETDEWEB)

    Till, C.E.; Chang, Y.I.; Kittel, J.H.; Fauske, H.K.; Lineberry, M.J.; Stevenson, M.G.; Amundson, P.I.; Dance, K.D.

    1980-07-01

    This report is a compilation of Fast Breeder Reactor (FBR) resource documents prepared to provide the technical basis for the US contribution to the International Nuclear Fuel Cycle Evaluation. The eight separate parts deal with the alternative fast breeder reactor fuel cycles in terms of energy demand, resource base, technical potential and current status, safety, proliferation resistance, deployment, and nuclear safeguards. An Annex compares the cost of decommissioning light-water and fast breeder reactors. Separate abstracts are included for each of the parts.

  2. Gas cooled fast reactor

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1972-06-01

    Although most of the development work on fast breeder reactors has been devoted to the use of liquid metal cooling, interest has been expressed for a number of years in alternative breeder concepts using other coolants. One of a number of concepts in which interest has been retained is the Gas-Cooled Fast Reactor (GCFR). As presently envisioned, it would operate on the uranium-plutonium mixed oxide fuel cycle, similar to that used in the Liquid Metal Fast Breeder Reactor (LMFBR), and would use helium gas as the coolant.

  3. Microfluidic electrochemical reactors

    Science.gov (United States)

    Nuzzo, Ralph G [Champaign, IL; Mitrovski, Svetlana M [Urbana, IL

    2011-03-22

    A microfluidic electrochemical reactor includes an electrode and one or more microfluidic channels on the electrode, where the microfluidic channels are covered with a membrane containing a gas permeable polymer. The distance between the electrode and the membrane is less than 500 micrometers. The microfluidic electrochemical reactor can provide for increased reaction rates in electrochemical reactions using a gaseous reactant, as compared to conventional electrochemical cells. Microfluidic electrochemical reactors can be incorporated into devices for applications such as fuel cells, electrochemical analysis, microfluidic actuation, pH gradient formation.

  4. Fusion Reactor Materials

    Energy Technology Data Exchange (ETDEWEB)

    Decreton, M

    2002-04-01

    The objective of SCK-CEN's programme on fusion reactor materials is to contribute to the knowledge on the radiation-induced behaviour of fusion reactor materials and components as well as to help the international community in building the scientific and technical basis needed for the construction of the future reactor. Ongoing projects include: the study of the mechanical and chemical (corrosion) behaviour of structural materials under neutron irradiation and water coolant environment; the investigation of the characteristics of irradiated first wall material such as beryllium; investigations on the management of materials resulting from the dismantling of fusion reactors including waste disposal. Progress and achievements in these areas in 2001 are discussed.

  5. New reactor type proposed

    CERN Multimedia

    2003-01-01

    "Russian scientists at the Research Institute of Nuclear Power Engineering in Moscow are hoping to develop a new reactor that will use lead and bismuth as fuel instead of uranium and plutonium" (1/2 page).

  6. Reactor Neutrino Spectra

    CERN Document Server

    Hayes, A C

    2016-01-01

    We present a review of the antineutrino spectra emitted from reactors. Knowledge of these and their associated uncertainties are crucial for neutrino oscillation studies. The spectra used to-date have been determined by either conversion of measured electron spectra to antineutrino spectra or by summing over all of the thousands of transitions that makeup the spectra using modern databases as input. The uncertainties in the subdominant corrections to beta-decay plague both methods, and we provide estimates of these uncertainties. Improving on current knowledge of the antineutrino spectra from reactors will require new experiments. Such experiments would also address the so-called reactor neutrino anomaly and the possible origin of the shoulder observed in the antineutrino spectra measured in recent high-statistics reactor neutrino experiments.

  7. Reactor BR2. Introduction

    Energy Technology Data Exchange (ETDEWEB)

    Gubel, P

    2001-04-01

    The BR2 is a materials testing reactor and is still one of SCK-CEN's important nuclear facilities. After an extensive refurbishment to compensate for the ageing of the installation, the reactor was restarted in April 1997. During the last three years, the availability of the installation was maintained at an average level of 97.6 percent. In the year 2000, the reactor was operated for a total of 104 days at a mean power of 56 MW. In 2000, most irradiation experiments were performed in the CALLISTO PWR loop. The report describes irradiations achieved or under preparation in 2000, including the development of advanced facilities and concept studies for new programmes. An overview of the scientific irradiation programmes as well as of the R and D programme of the BR2 reactor in 2000 is given.

  8. Future Reactor Experiments

    OpenAIRE

    He, Miao

    2013-01-01

    The measurement of the neutrino mixing angle $\\theta_{13}$ opens a gateway for the next generation experiments to measure the neutrino mass hierarchy and the leptonic CP-violating phase. Future reactor experiments will focus on mass hierarchy determination and the precision measurement of mixing parameters. Mass hierarchy can be determined from the disappearance of reactor electron antineutrinos based on the interference effect of two separated oscillation modes. Relative and absolute measure...

  9. Reactor Neutrino Experiments

    OpenAIRE

    Cao, Jun

    2007-01-01

    Precisely measuring $\\theta_{13}$ is one of the highest priority in neutrino oscillation study. Reactor experiments can cleanly determine $\\theta_{13}$. Past reactor neutrino experiments are reviewed and status of next precision $\\theta_{13}$ experiments are presented. Daya Bay is designed to measure $\\sin^22\\theta_{13}$ to better than 0.01 and Double Chooz and RENO are designed to measure it to 0.02-0.03. All are heading to full operation in 2010. Recent improvements in neutrino moment measu...

  10. Department of Reactor Technology

    DEFF Research Database (Denmark)

    Risø National Laboratory, Roskilde

    The general development of the Department of Reactor Technology at Risø during 1981 is presented, and the activities within the major subject fields are described in some detail. Lists of staff, publications, and computer programs are included.......The general development of the Department of Reactor Technology at Risø during 1981 is presented, and the activities within the major subject fields are described in some detail. Lists of staff, publications, and computer programs are included....

  11. Helias reactor studies

    Energy Technology Data Exchange (ETDEWEB)

    Beidler, C.D. [Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); Grieger, G. [Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); Harmeyer, E. [Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); Kisslinger, J. [Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); Karulin, N. [Nuclear Fusion Institute, Moscow (Russian Federation); Maurer, W. [Forschungszentrum Karlsruhe GmbH Technik und Umwelt (Germany); Nuehrenberg, J. [Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); Rau, F. [Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); Sapper, J. [Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); Wobig, H. [Max-Planck-Institut fuer Plasmaphysik, Garching (Germany)

    1995-10-01

    The present status of Helias reactor studies is characterised by the identification and investigation of specific issues which result from the particular properties of this type of stellarator. On the technical side these are issues related to the coil system, while physics studies have concentrated on confinement, alpha-particle behaviour and ignition conditions. The usual assumptions have been made in those fields which are common to all toroidal fusion reactors: blanket and shield, refuelling and exhaust, safety and economic aspects. For blanket and shield sufficient space has been provided, a detailed concept will be developed in future. To date more emphasis has been placed on scoping and parameter studies as opposed to fixing a specific set of parameters and providing a detailed point study. One result of the Helias reactor studies is that physical dimensions are on the same order as those of tokamak reactors. However, it should be noticed that this comparison is difficult in view of the large spectrum of tokamak reactors ranging from a small reactor like Aries, to a large device such as SEAFP. The notion that the large aspect ratio of 10 or more in Helias configurations also leads to large reactors is misleading, since the large major radius of 22 m is compensated by the average plasma radius of 1.8 m and the average coil radius of 5 m. The plasma volume of 1400 m{sup 3} is about the same as the ITER reactor and the magnetic energy of the coil system is about the same or even slightly smaller than envisaged in ITER. (orig.)

  12. INVAP's Research Reactor Designs

    OpenAIRE

    Eduardo Villarino; Alicia Doval

    2011-01-01

    INVAP, an Argentine company founded more than three decades ago, is today recognized as one of the leaders within the research reactor industry. INVAP has participated in several projects covering a wide range of facilities, designed in accordance with the requirements of our different clients. For complying with these requirements, INVAP developed special skills and capabilities to deal with different fuel assemblies, different core cooling systems, and different reactor layouts. This paper ...

  13. Aprendizaje basado en programación. Alimento transdisciplinar para el pensamiento creativo

    Directory of Open Access Journals (Sweden)

    Alberto Domingo Galán

    2013-11-01

    Full Text Available Este trabajo describe una actividad de aprendizaje transdisciplinar destinado a impulsar la creatividad y fomentar actitudes innovadoras. Combina biología molecular con programación de computadoras, pero más que el caso concreto, es un ejemplo de abordaje dirigido a impulsar la capacidad de innovación en el proceso educativo. Se basa en la convicción de que un conocimiento amplio y multidisciplinar es el sustrato más eficiente para transformar la creatividad individual en innovación práctica. Esta actividad, ya aplicada en más de seis cursos, utiliza una metodología de aprendizaje activo inscrita en el marco del Aprendizaje Basado en Proyectos y se diseñó inicialmente para las clases prácticas de laboratorio de una asignatura de Biología Molecular. Los participantes tienen que desarrollar una herramienta de software real, capaz de realizar un análisis de secuencias de ácidos nucleicos, incluyendo una interfaz de usuario interactiva. Comienzan a escribir el código real y a aprender los rudimentos de un la programación directamente aplicándolos a resolver un problema. Se trata de un “aprendizaje basado en programación” ya que la escritura del programa no es la finalidad, sino el medio para crear un entorno en el que los alumnos tienen que repensar y entender realmente la lógica detrás de muchos conceptos biológicos fundamentales ya aprendidos, pero que en esta actividad tienen que enfrentar en un contexto diferente y con un nuevo lenguaje y objetivos prácticos. En lugar de descripciones teóricas, el proceso de aprendizaje involucra a los participantes en un reto divertido y motivador, una meta exigente pero estimulante de crear su propia solución para un problema auténtico, que se reconoce como difícil, pero también como comprensible y realizable. Es una actividad realmente transdisciplinar que también trata de dar a los estudiantes una visión de un nuevo campo, ampliando su mente y motivándoles a explorar y

  14. Propiedades mecánicas de cermets basados en diboruro de titanio

    Directory of Open Access Journals (Sweden)

    Sánchez, J. M.

    2000-06-01

    Full Text Available Mechanical properties of titanium diboride (TiB2 cermets critically depend on the composition of the binder phase. Both, fracture toughness and hardness, are substantially increased by avoiding the formation of extremely brittle secondary borides formed during sintering by chemical reactions between TiB2 and the metallic additives. Fractographic observations of TiB2 cermets without secondary borides show the presence of ductile ligaments of the binder phase bridging the advancing crack tip. The powder metallurgy processing route applied to these materials allows modification of the binder phase structure from the ferritic iron-aluminium phase to Fe-Ni-Al austenite by changing the aluminium content of the powder mixtures. The highest toughness values have been obtained for the TiB2 cermets with an austenitic binder phase. X-ray diffraction analyses of the fracture surfaces of such samples show that the binder phase is metastable exhibiting stress induced martensitic transformation during fracture. This new family of materials presents an outstanding combination of hardness and toughness, comparable to those obtained with commercial grades of tungsten carbide (WC hardmetals.

    Las propiedades mecánicas de los cermets basados en diboruro de titanio (TiB2 dependen críticamente de la composición de la fase ligante. Se ha comprobado que tanto la tenacidad como la dureza aumentan significativamente si se evita la formación de boruros secundarios durante la sinterización en fase líquida. Las observaciones fractográficas realizadas en cermets basados en TiB2 sin boruros secundarios confirman el comportamiento plástico de la fase ligante durante la fractura. La ruta pulvimetalúrgica aplicada a estos materiales permite la modificación intencionada de la estructura de la fase ligante desde ferrita a austenita mediante adiciones de aluminio a las mezclas de polvos. Los valores de tenacidad más elevados se han obtenido para los cermets con

  15. The reactor antineutrino anomalies

    Energy Technology Data Exchange (ETDEWEB)

    Haser, Julia; Buck, Christian; Lindner, Manfred [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany)

    2016-07-01

    Major discoveries were made in the past few years in the field of neutrino flavour oscillation. Nuclear reactors produce a clean and intense flux of electron antineutrinos and are thus an essential neutrino source for the determination of oscillation parameters. Most currently the reactor antineutrino experiments Double Chooz, Daya Bay and RENO have accomplished to measure θ{sub 13}, the smallest of the three-flavour mixing angles. In the course of these experiments two anomalies emerged: (1) the reanalysis of the reactor predictions revealed a deficit in experimentally observed antineutrino flux, known as the ''reactor antineutrino anomaly''. (2) The high precision of the latest generation of neutrino experiments resolved a spectral shape distortion relative to the expected energy spectra. Both puzzles are yet to be solved and triggered new experimental as well as theoretical studies, with the search for light sterile neutrinos as most popular explanation for the flux anomaly. This talk outlines the two reactor antineutrino anomalies. Discussing possible explanations for their occurrence, recent and upcoming efforts to solve the reactor puzzles are highlighted.

  16. Moon base reactor system

    Science.gov (United States)

    Chavez, H.; Flores, J.; Nguyen, M.; Carsen, K.

    1989-01-01

    The objective of our reactor design is to supply a lunar-based research facility with 20 MW(e). The fundamental layout of this lunar-based system includes the reactor, power conversion devices, and a radiator. The additional aim of this reactor is a longevity of 12 to 15 years. The reactor is a liquid metal fast breeder that has a breeding ratio very close to 1.0. The geometry of the core is cylindrical. The metallic fuel rods are of beryllium oxide enriched with varying degrees of uranium, with a beryllium core reflector. The liquid metal coolant chosen was natural lithium. After the liquid metal coolant leaves the reactor, it goes directly into the power conversion devices. The power conversion devices are Stirling engines. The heated coolant acts as a hot reservoir to the device. It then enters the radiator to be cooled and reenters the Stirling engine acting as a cold reservoir. The engines' operating fluid is helium, a highly conductive gas. These Stirling engines are hermetically sealed. Although natural lithium produces a lower breeding ratio, it does have a larger temperature range than sodium. It is also corrosive to steel. This is why the container material must be carefully chosen. One option is to use an expensive alloy of cerbium and zirconium. The radiator must be made of a highly conductive material whose melting point temperature is not exceeded in the reactor and whose structural strength can withstand meteor showers.

  17. Profesionalización de promotores de lectura con el aprendizaje basado en proyectos mediado por TIC

    Directory of Open Access Journals (Sweden)

    Mario Miguel Ojeda-Ramírez

    2017-01-01

    Full Text Available Se revisa brevemente e l aprendizaje basado en proyectos (ABP mediado por TIC con el fin de motivar el contexto adecuado y los fundamentos para presentar el plan de estudios y las estrategias de aprendizaje utilizadas en la Especialización en Promoción de la Lectura (EPL, un programa de posgrado de la Universidad Veracruzana. Se describe e l uso de EMINUS, un entorno virtual de aprendizaje institucional , bajo un enfoque bimodal o blended learning; destacando el uso de la bitácora y los resultados asociados con el diseño, la ejecución y el reporte de los proyectos de promoción de la lectura. Se discuten los resultados de las dos primeras generaciones; p or último, se identifican las áreas de oportunidad de mejora de este sistema de entrenamiento basado en un esquema de aprendizaje personalizado med iado por TIC.

  18. Administración de proyectos de capacitación basados en tecnología

    OpenAIRE

    Gómez Zermeño, Marcela Georgina; Alemán de la Garza, Lorena

    2012-01-01

    Este eBook posee información relevante y actualizada sobre el tema  de administración de proyectos de capacitación basados en tecnología. Esta publicación tiene como características sobresalientes su estructura  concisa, actividades prácticas, autoevaluaciones de aprendizaje, ligas de interés, formato atractivo, fácil lectura, navegación sencilla.

  19. Utilidad de los recursos basados en la evidencia en la consulta del médico de familia

    OpenAIRE

    2014-01-01

    DESCRIPTORES Bases de Datos como Asunto, Medicina Basada en la Evidencia, Medicina Familiar y Comunitaria. OBJETIVOS 1) Comparar características de diferentes recursos basados en la evidencia disponibles en el punto de cuidado (POC). 2) Describir sus características formales. 3) Analizar su utilidad para contestar dudas de médicos de familia (MF). METODOLOGÍA Evaluación realizada desde dos enfoques independientes: a) Formal: valorada por expertos en estas fuentes de do...

  20. Herramienta para programar un controlador lógico programable basado en hardware reconfigurable

    Directory of Open Access Journals (Sweden)

    Valery Moreno Vega

    2011-09-01

    Full Text Available Normal 0 21 false false false MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabla normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-ansi-language:#0400; mso-fareast-language:#0400; mso-bidi-language:#0400;} El presente trabajo se basa en el desarrollo de una herramienta que permita programar un controlador lógico programable (PLC basado en hardware reconfigurable. El desarrollo de la aplicación está  sustentado por una de las metodologías ágiles descrita por XP, utilizando las técnicas de modelación establecidas por el Lenguaje Unificado de Modelado (UML y haciendo uso de una potente herramienta de programación y diseño de interfaces gráficas como es Qt. La programación del PLC se realiza mediante el lenguaje de escalera, atendiendo la norma IEC 61131-3.

  1. Cuidados basados en narrativas: redefiniendo la jerarquía de la evidencia

    Directory of Open Access Journals (Sweden)

    Lorenzo Mariano Juárez

    2013-06-01

    Full Text Available Desde finales de los noventa proliferan trabajos que, aglutinados como Narrative Based Medicine (NBM, persiguen redefinir la práctica clínica orientándola hacia el paciente y su narrativa. Emergidos como un discurso eminentemente crítico y contestatario sobre la ortodoxia de la Evidence Based Medicine (EBM, actualmente persiguen perspectivas integracionistas que pretenden incluir sendos movimientos en un modelo de atención que reconstruya las nociones y jerarquía de la "evidencia". Ideológicamente, la NBM propone una redefinición de la ethos de la práctica médica resituando la experiencia del paciente como evidencia de primer orden. Sin embargo, el impacto de este movimiento en los cuidados enfermeros ha sido prácticamente nulo. Este artículo, primero de una serie, explora las bases teóricas y principios de la NBM sugiriendo un marco de trabajo que cimiente unos cuidados de Enfermería Basados en Narrativas, incluyendo una revisión de los estudios enmarcados en esta orientación y una reflexión sobre su carácter "vanguardista".

  2. USO DEL RAZONAMIENTO BASADO EN CASOS PARA LA ENSEÑANZA DE TEMAS MÉDICOS

    Directory of Open Access Journals (Sweden)

    Vivian Estrada Sentí

    2002-05-01

    Full Text Available

    Dentro de las técnicas de inteligencia artificial, el Razonamiento Basado en Casos (RBC ocupa un importante lugar ya que facilita el uso de la experiencia acumulada para la toma de decisiones sobre las nuevas situaciones que se presenten. Los autores afirman que el RBC es una importante herramienta de apoyo a la enseñanza de temas médicos, basándose en los resultados de las investigaciones realizadas, y exponen una de las bases de casos utilizadas con estos fines, por su eficiencia para el diagnostico, el pronóstico y la conducta médica.

    Abstract

    In particular, the introduction of artificial intelligence methods and its application in medicine constitute an interesting and perspective scientific field. Specially, Case Based Reasoning (CBR plays an important role in medical science. CBR methods and techniques have been used with success in complex medical decision making. Paper's authors argued CBR represents a very important tool in medical learning and teaching.

  3. Estudio multinivel basado em PISA 2009: determinantes del rendimiento educativo em Uruguay

    Directory of Open Access Journals (Sweden)

    Vivian Tatiane Rodrigues Yuane

    2015-12-01

    Full Text Available Los resultados de PISA 2009 manifiestan que el nivel educativo de los estudiantes Uruguayos se sitúa en una posición por debajo del promedio de los países de la OCDE, además, el promedio de los mismos discrepa entre las regiones del país. Frente a eso, este ensayo se propone a analizar los determinantes del desempeño estudiantil basado en los factores que tradicionalmente la literatura ha identificado como determinantes de la eficacia escolar. Dichos factores están relacionados con el propio alumno, con el centro educativo al que pertenece, su familia y su situación socioeconómica. Este ensayo además, procura controlar los aspectos regionales, para ello, la metodología empleada en este estudio es la regresión multinivel con la que es posible considerar la estructura jerárquica de las variables, el modelo incluye tres niveles: alumno, escuelas y regiones. Los resultados muestran que el nivel educativo de los padres, la calificación de los profesores y el nivel socioeconómico de los alumnos que concurren a la misma escuela, cuanto mayor sean sus valores correspondientes, mayor es el resultado esperado en el rendimiento de los alumnos en el área de comprensión lectora.

  4. Predictor Basado en Prototipos Difusos y Clasificación No-supervisada

    Directory of Open Access Journals (Sweden)

    Aníbal Vásquez

    2015-07-01

    Full Text Available La construcción de prototipos difusos es un método que permite describir a los elementos más representativos de un clúster, a través de su tipicidad. Los prototipos, como los datos más representativos de cada clúster, pueden ser usados en un proceso de clasificación como datos de entrenamiento. Estos prototipos y los clusters pueden ser construidos mediante algoritmos de clustering difuso; los clusters representados por los prototipos poseen variables descriptivas y atributos que pueden ser asociados a nuevos datos. El siguiente trabajo propone una arquitectura que utiliza herramientas de clustering y prototipado difuso, para clasificación no-supervisada y predicción a través de la extracción de variables descriptivas. El desarrollo de un caso de estudio permitió validar el modelo de clasificación para predecir el riesgo de falla en el rendimiento académico de estudiantes, basado en su carga semestral y rendimiento académico, en la selección de cursos antes de registrarse, con un porcentaje de certeza significativo.

  5. COROTIPOS PRELIMINARES DE PERÚ BASADOS EN LA DISTRIBUCIÓN DE LA FAMILIA ASTERACEAE

    Directory of Open Access Journals (Sweden)

    Berni Britto

    2014-01-01

    Full Text Available El presente estudio se basa en el concepto de categorías corológicas o corotipos para formular una nueva hipótesis de clasificación biogeográfica del Perú basado en la distribución de la familia Astera - ceae. La información recabada dio como resultado que existen 1669 especies de Asteraceae registradas en Perú (hasta el año 2008, distribuidas en 255 géneros. El territorio peruano se dividió en 218 Distritos de Reporte que representan a los 24 departamentos divididos en franjas de 500 m de altitud. La base de datos biogeográficos de Asteraceae se obtuvo cruzando los registros de distribución actualizados con los Distritos de Reporte, expresándose en una matriz de presencia-ausencia. El análisis de datos dio como resultado un total de 14 corotipos preliminares para el Perú: Abiseo, Amotape, Andino, Apurímac-Huan - cavelica, Chachapoyas-Huánuco, Huancabamba, Huascarán, Ica, Lima-Piura, Loreto-Ucayali, Manu, Pasco, Sandia y Tacna.

  6. Emulación en hardware de circuitos cuánticos basados en compuertas Toffoli

    Directory of Open Access Journals (Sweden)

    Jorge E. Duarte-Sánchez

    2014-01-01

    Full Text Available Este trabajo presenta el diseño de una arquitectura hardware para emular circuitos cuánticos basados en compuertas tipo Toffoli con la cual se pueden emular circuitos de más de 50 qubits. El estado del sistema se obtiene procesando independientemente cada estado base mediante las funciones determinadas por las compuertas cuánticas para cada qubit; el tiempo requerido para la emulación crece exponencialmente en función del número de qubits que se usan solamente para generar una superposición de estados, y no en función de la cantidad total de qubits del sistema como ocurre cuando se usa la representación matricial convencional. Adicionalmente, se diseñó un arreglo de unidades de procesamiento para disminuir el tiempo de ejecución. Los resultados de síntesis permiten concluir que se requieren 9,35 segundos para emular la exponenciación modular de 8 bits, la cual utiliza 48 qubits, 155.312 compuertas cuánticas y requiere procesar 131.072 estados base. Estos resultados también permiten estimar que se pueden implementar 256 unidades de procesamiento de 52 qubits en el FPGA EP3C120F780I7.

  7. Las TIC: propuesta para el aprendizaje de enfermería basado en problemas

    Directory of Open Access Journals (Sweden)

    Óscar Boude-Figueredo

    2008-01-01

    Full Text Available Este artículo presenta el análisis de un proceso de investigación cuyo objetivo fue identificar las competencias sobre redes de computadores que alcanzan los estudiantes de enfermería a través del trabajo independiente, en un ambiente de aprendizaje (AA que hace uso de un material educativo digital basado en problemas. En el estudio participaron 22 estudiantes de enfermería de la Universidad de La Sabana, que cursaron la materia telemática durante el segundo semestre de 2007. Se recurrió al estudio de caso, ya que éste permite ver un AA desde todas sus aristas, así como comprender las prácticas y los imaginarios de los actores que intervienen, sus relaciones, tensiones y transformaciones. El 27% de los estudiantes superaron los niveles esperados en el desarrollo de las competencias planteadas, el 63% alcanzó los niveles esperados, y el 14% sólo llegó a los niveles mínimos. Estos logros estuvieron relacionados con las metodologías desarrolladas por cada pareja para solucionar los casos, y con factores tales como el intercambio de saberes con pares, los esquemas de pensamiento propios, la disposición y la actitud de los estudiantes.

  8. El enfoque educativo basado en competencias, un reto que enfrenta la Universidad Veracruzana

    Directory of Open Access Journals (Sweden)

    Adoración Barrales Villegas

    2012-12-01

    Full Text Available Este artículo tiene como propósito compartir la experiencia que ha tenido la Universidad Veracruzana en la promoción e implementación del enfoque educativo basado en competencias. La incorporación obedece a la demanda internacional de formar profesionistas competentes en los ámbitos profesional, personal y social.Una de las acciones relevantes ha sido la capacitación de su personal docente y la implementación de una estrategia denominada Proyecto Aula. Este proyecto va dirigido a sistematizar la práctica docente a partir de la elaboración, aplicación y evaluación de un diseño instruccional para cada una de las experiencias educativas (asignaturas que se imparten al interior de sus programas educativos. Esta es la razón de que se revisen conceptos como competencia, tipos, enfoques, metodología y evaluación por competencias enfatizando los retos y aciertos de nuestra institución.

  9. Codificador RS(n,k basado en LFCS: caso de estudio RS(7,3

    Directory of Open Access Journals (Sweden)

    Cecilia Sandoval-Ruiz

    2012-01-01

    Full Text Available El presente artículo presenta el diseño de un codi® cador Reed Solomon basado en un circuito concurrente, LFCS - Linear Feedback Concurrent Structure- que permite la generación de los símbolos de redundancia del código de forma paralela, siempre que se le suministren los k símbolos de información a codificar de forma simultánea, el codifi cador ofrece a su salida los símbolos de redundancia correspondientes. Para lograr este desarrollo se generalizó el modelo matemáticos para la descripción del comportamiento del codificador, se realizó la configuración en lenguaje descriptor de hardware VHDL de un codificador Reed Solomon, tomando como caso de estudio el RS(7,3, se simuló el diseño propuesto validando así su funcionamiento, para finalmente realizar la comparación de la implementación del codifi cador entre la versión secuencial y la versión basada en LFCS, obteniendo una reducción de componentes hardware y optimizando la velocidad de respuesta y consumo de potencia. Concluyendo, que el diseño del codi® cador propuesto valida el modelo concurrente generalizado a partir de la correspondencia con la arquitectura del LFCS.

  10. Experiencia docente mediante la Metodología de Aprendizaje Basado en Problemas

    Directory of Open Access Journals (Sweden)

    José Manuel López-Guede

    2015-07-01

    Full Text Available En este artículo se describe una experiencia docente de implantación de Aprendizaje Basado en Problemas (ABP llevada a cabo en la Escuela Universitaria de Ingeniería de Vitoria-Gasteiz, de la Universidad del País Vasco (UPV/EHU. La asignatura objeto de la implantación ha sido Arquitectura de Computadores, del Grado en Ingeniería Informática de Gestión y Sistemas de Información. En el artículo se recogen los elementos principales a considerar en toda implantación como son las competencias específicas y transversales a adquirir por el alumnado, por lo que se recoge el temario y los resultados del aprendizaje a lograr y evaluar. Se detalla el problema estructurante diseñado y su división en subproblemas, así como los logros alcanzados, siendo estos altamente satisfactorios tanto para el alumnado en general como para el profesorado.

  11. EL LENGUAJE ORDINARIO: LA CLAVE PARA EL APRENDIZAJE DE LAS MATEMÁTICAS BASADO EN PROBLEMAS

    Directory of Open Access Journals (Sweden)

    José Ángel García Retana

    2015-01-01

    Full Text Available En el año 2012 el Ministerio de Educación Pública de Costa Rica, planteó una nueva propuesta de educación matemática para responder a las exigencias sociales y económicas actuales. Esta propuesta se fundamenta en el aprendizaje basado en problemas (ABP como estrategia metodológica. En el caso del aprendizaje de las matemáticas, tal propuesta demanda considerar la relación que existe entre el lenguaje ordinario y el lenguaje matemático, por cuanto el primero es central en el proceso educativo. Este tipo de aprendizaje se debe conceptualizar en su doble función de herramienta, es decir, para resolver problemas, y como disciplina, dado que el lenguaje matemático permite representar los conceptos que trata, al menos de dos maneras diferentes, la semántica y la gráfico-visual, los cuales en gran medida son determinados por el lenguaje ordinario. Así, el lenguaje ordinario y su campo semántico constituyen el eje transversal para el aprendizaje de esta estrategia metodológica.

  12. Reactor Safety Planning for Prometheus Project, for Naval Reactors Information

    Energy Technology Data Exchange (ETDEWEB)

    P. Delmolino

    2005-05-06

    The purpose of this letter is to submit to Naval Reactors the initial plan for the Prometheus project Reactor Safety work. The Prometheus project is currently developing plans for cold physics experiments and reactor prototype tests. These tests and facilities may require safety analysis and siting support. In addition to the ground facilities, the flight reactor units will require unique analyses to evaluate the risk to the public from normal operations and credible accident conditions. This letter outlines major safety documents that will be submitted with estimated deliverable dates. Included in this planning is the reactor servicing documentation and shipping analysis that will be submitted to Naval Reactors.

  13. REACTOR GROUT THERMAL PROPERTIES

    Energy Technology Data Exchange (ETDEWEB)

    Steimke, J.; Qureshi, Z.; Restivo, M.; Guerrero, H.

    2011-01-28

    Savannah River Site has five dormant nuclear production reactors. Long term disposition will require filling some reactor buildings with grout up to ground level. Portland cement based grout will be used to fill the buildings with the exception of some reactor tanks. Some reactor tanks contain significant quantities of aluminum which could react with Portland cement based grout to form hydrogen. Hydrogen production is a safety concern and gas generation could also compromise the structural integrity of the grout pour. Therefore, it was necessary to develop a non-Portland cement grout to fill reactors that contain significant quantities of aluminum. Grouts generate heat when they set, so the potential exists for large temperature increases in a large pour, which could compromise the integrity of the pour. The primary purpose of the testing reported here was to measure heat of hydration, specific heat, thermal conductivity and density of various reactor grouts under consideration so that these properties could be used to model transient heat transfer for different pouring strategies. A secondary purpose was to make qualitative judgments of grout pourability and hardened strength. Some reactor grout formulations were unacceptable because they generated too much heat, or started setting too fast, or required too long to harden or were too weak. The formulation called 102H had the best combination of characteristics. It is a Calcium Alumino-Sulfate grout that contains Ciment Fondu (calcium aluminate cement), Plaster of Paris (calcium sulfate hemihydrate), sand, Class F fly ash, boric acid and small quantities of additives. This composition afforded about ten hours of working time. Heat release began at 12 hours and was complete by 24 hours. The adiabatic temperature rise was 54 C which was within specification. The final product was hard and displayed no visible segregation. The density and maximum particle size were within specification.

  14. Scaleable, High Efficiency Microchannel Sabatier Reactor Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A Microchannel Sabatier Reactor System (MSRS) consisting of cross connected arrays of isothermal or graded temperature reactors is proposed. The reactor array...

  15. LMFBR type reactor

    Energy Technology Data Exchange (ETDEWEB)

    Shimizu, Takeshi; Iida, Masaaki; Moriki, Yasuyuki

    1994-10-18

    A reactor core is divided into a plurality of coolants flowrate regions, and electromagnetic pumps exclusively used for each of the flowrate regions are disposed to distribute coolants flowrates in the reactor core. Further, the flowrate of each of the electromagnetic pumps is automatically controlled depending on signals from a temperature detector disposed at the exit of the reactor core, so that the flowrate of the region can be controlled optimally depending on the burning of reactor core fuels. Then, the electromagnetic pumps disposed for every divided region are controlled respectively, so that the coolants flowrate distribution suitable to each of the regions can be attained. Margin for fuel design is decreased, fuels are used effectively, as well as an operation efficiency can be improved. Moreover, since the electromagnetic pump has less flow resistance compared with a mechanical type pump, and flow resistance of the reactor core flowrate control mechanism is eliminated, greater circulating flowrate can be ensured after occurrence of accident in a natural convection using a buoyancy of coolants utilizable for after-heat removal as a driving force. (N.H.).

  16. Reactor Structural Materials: Reactor Pressure Vessel Steels

    Energy Technology Data Exchange (ETDEWEB)

    Chaouadi, R

    2000-07-01

    The objectives of SCK-CEN's R and D programme on Rector Pressure Vessel (RPV) Steels are:(1) to complete the fracture toughness data bank of various reactor pressure vessel steels by using precracked Charpy specimens that were tested statically as well as dynamically; (2) to implement the enhanced surveillance approach in a user-friendly software; (3) to improve the existing reconstitution technology by reducing the input energy (short cycle welding) and modifying the stud geometry. Progress and achievements in 1999 are reported.

  17. Operation of Reactor

    Institute of Scientific and Technical Information of China (English)

    1996-01-01

    3.1 Annual Report of SPR Operation Chu Shaochu Having overseen by National Nuclear Safety Administration and specialists, the reactor restarted up successfully after Safety renovation on April 16, 1996. In August 1996 the normal operation of SPR was approved by the authorities of Naitonal Nuclear Safety Administration. 1 Operation status In 1996, the reactor operated safely for 40 d and the energy released was about 137.3 MW·d. The operation status of SPR is shown in table 1. The reactor started up to higher power (power more than 1 MW) and lower power (for physics experiments) 4 times and 14 times respectively. Measurement of control rod efficiency and other measurement tasks were 2 times and 5 times respectively.

  18. Nuclear Rocket Engine Reactor

    CERN Document Server

    Lanin, Anatoly

    2013-01-01

    The development of a nuclear rocket engine reactor (NRER ) is presented in this book. The working capacity of an active zone NRER under mechanical and thermal load, intensive neutron fluxes, high energy generation (up to 30 MBT/l) in a working medium (hydrogen) at temperatures up to 3100 K is displayed. Design principles and bearing capacity of reactors area discussed on the basis of simulation experiments and test data of a prototype reactor. Property data of dense constructional, porous thermal insulating and fuel materials like carbide and uranium carbide compounds in the temperatures interval 300 - 3000 K are presented. Technological aspects of strength and thermal strength resistance of materials are considered. The design procedure of possible emergency processes in the NRER is developed and risks for their origination are evaluated. Prospects of the NRER development for pilotless space devices and piloted interplanetary ships are viewed.

  19. Thermionic Reactor Design Studies

    Energy Technology Data Exchange (ETDEWEB)

    Schock, Alfred

    1994-08-01

    Paper presented at the 29th IECEC in Monterey, CA in August 1994. The present paper describes some of the author's conceptual designs and their rationale, and the special analytical techniques developed to analyze their (thermionic reactor) performance. The basic designs, first published in 1963, are based on single-cell converters, either double-ended diodes extending over the full height of the reactor core or single-ended diodes extending over half the core height. In that respect they are similar to the thermionic fuel elements employed in the Topaz-2 reactor subsequently developed in the Soviet Union, copies of which were recently imported by the U.S. As in the Topaz-2 case, electrically heated steady-state performance tests of the converters are possible before fueling.

  20. An Overview of Reactor Concepts, a Survey of Reactor Designs.

    Science.gov (United States)

    1985-02-01

    Public Affairs Office and is releasaole to the National Technical Information Services (NTIS). At NTIS, it will be available to the general public...Reactors that use deu- terium (heavy water) as a coolant can use natural uranium as a fuel. The * Canadian reactor, CANDU , utilizes this concept...reactor core at the top and discharged at the Dotton while the reactor is in operation. The discharged fuel can then b inspected to see if it can De used

  1. Oscillatory flow chemical reactors

    Directory of Open Access Journals (Sweden)

    Slavnić Danijela S.

    2014-01-01

    Full Text Available Global market competition, increase in energy and other production costs, demands for high quality products and reduction of waste are forcing pharmaceutical, fine chemicals and biochemical industries, to search for radical solutions. One of the most effective ways to improve the overall production (cost reduction and better control of reactions is a transition from batch to continuous processes. However, the reactions of interests for the mentioned industry sectors are often slow, thus continuous tubular reactors would be impractically long for flow regimes which provide sufficient heat and mass transfer and narrow residence time distribution. The oscillatory flow reactors (OFR are newer type of tube reactors which can offer solution by providing continuous operation with approximately plug flow pattern, low shear stress rates and enhanced mass and heat transfer. These benefits are the result of very good mixing in OFR achieved by vortex generation. OFR consists of cylindrical tube containing equally spaced orifice baffles. Fluid oscillations are superimposed on a net (laminar flow. Eddies are generated when oscillating fluid collides with baffles and passes through orifices. Generation and propagation of vortices create uniform mixing in each reactor cavity (between baffles, providing an overall flow pattern which is close to plug flow. Oscillations can be created by direct action of a piston or a diaphragm on fluid (or alternatively on baffles. This article provides an overview of oscillatory flow reactor technology, its operating principles and basic design and scale - up characteristics. Further, the article reviews the key research findings in heat and mass transfer, shear stress, residence time distribution in OFR, presenting their advantages over the conventional reactors. Finally, relevant process intensification examples from pharmaceutical, polymer and biofuels industries are presented.

  2. Perspectives on reactor safety

    Energy Technology Data Exchange (ETDEWEB)

    Haskin, F.E. [New Mexico Univ., Albuquerque, NM (United States). Dept. of Chemical and Nuclear Engineering; Camp, A.L. [Sandia National Labs., Albuquerque, NM (United States)

    1994-03-01

    The US Nuclear Regulatory Commission (NRC) maintains a technical training center at Chattanooga, Tennessee to provide appropriate training to both new and experienced NRC employees. This document describes a one-week course in reactor, safety concepts. The course consists of five modules: (1) historical perspective; (2) accident sequences; (3) accident progression in the reactor vessel; (4) containment characteristics and design bases; and (5) source terms and offsite consequences. The course text is accompanied by slides and videos during the actual presentation of the course.

  3. Reactor Materials Research

    Energy Technology Data Exchange (ETDEWEB)

    Van Walle, E

    2002-04-01

    The activities of SCK-CEN's Reactor Materials Research Department for 2001 are summarised. The objectives of the department are: (1) to evaluate the integrity and behaviour of structural materials used in nuclear power industry; (2) to conduct research to unravel and understand the parameters that determine the material behaviour under or after irradiation; (3) to contribute to the interpretation, the modelling of the material behaviour and to develop and assess strategies for optimum life management of nuclear power plant components. The programmes within the department are focussed on studies concerning (1) Irradiation Assisted Stress Corrosion Cracking (IASCC); (2) nuclear fuel; and (3) Reactor Pressure Vessel Steel.

  4. Fusion Reactor Materials

    Energy Technology Data Exchange (ETDEWEB)

    Decreton, M

    2000-07-01

    SCK-CEN's research and development programme on fusion reactor materials includes: (1) the study of the mechanical behaviour of structural materials under neutron irradiation (including steels, inconel, molybdenum, chromium); (2) the determination and modelling of the characteristics of irradiated first wall materials such as beryllium; (3) the detection of abrupt electrical degradation of insulating ceramics under high temperature and neutron irradiation; (4) the study of the dismantling and waste disposal strategy for fusion reactors.; (5) a feasibility study for the testing of blanket modules under neutron radiation. Main achievements in these topical areas in the year 1999 are summarised.

  5. QUÉ SE PUEDE APRENDER DE LA LITERATURA SOBRE EL APRENDIZAJE BASADO EN PROBLEMAS

    Directory of Open Access Journals (Sweden)

    YURI GORBANEFF

    2010-01-01

    Full Text Available El trabajo es una revisión de la literatura sobre la aplicabilidad del aprendizaje basado en problemas (ABP en la enseñanza de la administración. El método de ABP se fundamenta en el constructivismo y teorías derivadas del constructivismo, como la de aprendizaje signifi cativo, las teorías socio cultural, dinámica y cognoscitiva de aprendizaje. El ABP fue aplicado con éxito en la enseñanza de derecho y medicina. Los investigadores que estudian su aplicación en la enseñanza de administración, están de acuerdo en que el ABP contribuye a mejorar la comprensión de lectura, la actitud deliberativa, refl exiva y critica de los alumnos, genera las habilidades de liderazgo, trabajo en equipo, emprendimiento y de aprendizaje autónomo, contribuye a la motivación del alumno por la carrera de administración. Existen los obstáculos para el ABP, la naturaleza del saber administrativo que se apoya sobre la experiencia e intuición, el modesto lugar que la solución de problemas ocupa en la práctica del recién egresado de administración, la ausencia del material didáctico apropiado. Las bondades del ABP ameritan futura investigación para remover los obstáculos que difi cultan su aplicación.

  6. MIDDIS: ARQUITECTURA DE REFERENCIA PARA LA INTERACCIÓN DE SERVICIOS BASADOS EN SOA E IMS

    Directory of Open Access Journals (Sweden)

    Ximena Velasco Melo

    2010-01-01

    Full Text Available En telecomunicaciones la tendencia actual está dirigida hacia una búsqueda de la convergencia de redes fijas y móviles, y por lo tanto, las redes que se diseñan son más complejas. Así mismo, se presentan nuevos retos en el campo de la interconexión e integración de servicios a través de múltiples redes, tecnologías y áreas de negocio, lo cual hace imprescindible interoperar los servicios de las Tecnologías de Información (Information Technologies, IT , con los de telecomunicaciones. Para aportar en la solución de estos retos y debido además, a la ausencia de un entorno de telecomunicaciones convergente y completamente adecuado para la prestación de servicios tradicionales y nuevos, en este artículo se presenta una arquitectura de referencia que permite la habilitación y entrega rápida de servicios convergentes para el mundo IT y el mundo de las Telecomunicaciones, con la mediación en la interacción de servicios basados en la Arquitectura Orientada a Servicios (Service Oriented Architecture, SOA, y el Subsistema Multimedia IP (IP Multimedia Subsystem, IMS . La característica esencial del middleware, implementado en un Entorno de Ejecución de Lógica de Servicio (Service Logic Execution Environment, SLEE, consiste en que IMS utiliza a SOA para integrar sus propios elementos software con componentes externos y de esta manera, se logra la combinación de las facilidades de la Web y de IMS para exponer un conjunto de servicios enriquecidos para ambos mundos.

  7. Propuesta de esquemas de tratamiento antituberculosis basados en la susceptibilidad A isoniacida y rifampicina

    Directory of Open Access Journals (Sweden)

    Alberto Mendoza-Ticona

    Full Text Available Objetivo. Elaborar esquemas de tratamiento para tuberculosis de acuerdo con sus perfiles de susceptibilidad a isoniacida (H y rifampicina (R. Materiales y métodos. Un total de 12 311 aislamientos de M. tuberculosis (Instituto Nacional de Salud, 2007-2009 se clasificaron en cuatro grupos de acuerdo con su susceptibilidad a H y R. En cada grupo se analizó la sensibilidad a etambutol (E, pirazinamida (Z, estreptomicina (S, kanamicina (Km, capreomicina (Cm, ciprofloxacina (Cfx, etionamida (Eto, cicloserina (Cs y ácido p-amino salicílico (PAS. En base a los perfiles de resistencia, principios de terapéutica de la Organización Mundial de la Salud y costos en el país, se elaboraron los esquemas más adecuados para cada grupo. Se definió la eficacia potencial (EP como la proporción de cepas sensibles a tres o cuatro drogas del esquema evaluado. Resultados. Los esquemas con el menor costo y la mayor EP a tres y cuatro drogas para tuberculosis sensible a H y R fueron: HRZ (EP=99,5%, HREZ (EP=99,1%; REZCfx (EP=98,9% y para tuberculosis resistente a H: REZCfxKm (EP=97,7%. Para tuberculosis resistente a R: HEZCfx (EP=96,8% y HEZCfxKm (EP=95,4%; el esquema con mejor eficacia potencial para tuberculosis multidrogorresistente fue EZCfxKmEtoCs (EP=82,9%. Conclusión. Basados en la resistencia a H y R se han elaborado y seleccionado esquemas de tratamiento con la más alta probabilidad de eficacia. Esta propuesta es una alternativa viable para hacer frente a la tuberculosis en Perú donde el acceso a pruebas de sensibilidad rápida a H y R se viene expandiendo.

  8. Sistema basado en casos para apoyar el proceso de clasificación penitenciaria

    Directory of Open Access Journals (Sweden)

    Yadira Benavides Zaila

    2012-12-01

    Full Text Available Los sistemas de clasificación del régimen de severidad, se consideran el cerebro de la gestión de un Sistema Penitenciario ya que son esenciales para proyectar las necesidades de recursos en el futuro. Un correcto funcionamiento del sistema de clasificación permite la toma de decisiones en relación a la construcción de espacios para la reclusión, contratación y capacitación del personal, establecimiento de programas de educación y rehabilitación, de acuerdo a las necesidades de los internos. El presente trabajo tiene como objetivo el desarrollo de un sistema inteligente que permita insertarse en el proceso de calificación en los sistemas penitenciarios. El diseño del sistema estará enfocado en la técnica de Razonamiento Basado en Casos que permita utilizar la experiencia de expertos en el campo de la clasificación del nivel de severidad dadas las características de un sujeto. A partir del análisis de sistemas de clasificación utilizados en varios países, y la validación de expertos, se proponen los rasgos para conformar los casos de la Base de Casos del sistema y la relevancia de cada una de ellos. La utilización del sistema propuesto contribuirá a acelerar el proceso de clasificación y evitar o disminuir errores durante su ejecución.

  9. Sistema Inteligente de Supervisión de Alarmas Basado en Microcontroladores PIC, SISAP

    Directory of Open Access Journals (Sweden)

    Ioslán Sánchez Martínez

    2010-09-01

    Full Text Available Normal 0 21 false false false MicrosoftInternetExplorer4 st1:*{behavior:url(#ieooui } /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabla normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-ansi-language:#0400; mso-fareast-language:#0400; mso-bidi-language:#0400;} En este artículo se describe hasta la etapa presente de desarrollo del prototipo SISAP (Sistema Inteligente de Supervisión de Alarmas basado en Microcontroladores PICs desarrollado a partir de una propuesta de la Dirección Territorial de ETECSA de Sancti Spíritus con el fin de incrementar las prestaciones de los sistemas instalados para la supervisión de alarmas tecnológicas en centros no atendidos del territorio.  El dispositivo SISAP se encuentra en la versión de desarrollo 0.5 en estado “no concluido”. Hasta este punto es capaz de manejar hasta 40 eventos, que pueden ser on/off o nivele de voltaje y transmitirlos a través de una interfaz telefónica utilizando un protocolo de tonos DTMF. Palabras Clave: Alarmas, Microcontrolador PIC, Voltajes, Eventos on/off, Tonos DTMF.

  10. Sistema de costos basado en actividades en hoteles cuatro estrellas del estado Mérida, Venezuela

    Directory of Open Access Journals (Sweden)

    Marysela Coromoto Morillo Moreno

    2017-03-01

    Full Text Available Las empresas actualmente demandan sistemas de costos que reporten un mayor detalle en la información generada, con el propósito de orientar la aplicación de estrategias que conduzcan a captar y apropiarse de mayores espacios de mercado, sobre todo cuando la competitividad es elevada; por ello, se formuló un sistema de costos basado en actividades, conocido por sus siglas en inglés como abc (Activity-Based Costing, aplicado a los hoteles de turismo de cuatro estrellas de Mérida, en Venezuela, para el control y reducción de costos en los servicios prestados. A partir de una investigación de carácter exploratorio, con un diseño de campo y con apoyo documental, se halló que el sector hotelero encuentra en el abc una oportunidad para afinar controles sobre los altos y variados costos en los que incurre a partir del conocimiento profundo de actividades consumidas, con sus medidas y frecuencia. De esta manera, se obtiene el costo real de los distintos servicios al vincularlos con las actividades desarrolladas para su obtención; finalmente, se sugiere un conjunto de variables que pudieran fungir como generadoras de valor e indicadoras de eficiencia. Se concluye que el abc representa una herramienta de gestión que orienta las decisiones estratégicas y el control de los costos con la consecuente reducción de los mismos para la maximización de beneficios.

  11. High Flux Isotope Reactor (HFIR)

    Data.gov (United States)

    Federal Laboratory Consortium — The HFIR at Oak Ridge National Laboratory is a light-water cooled and moderated reactor that is the United States’ highest flux reactor-based neutron source. HFIR...

  12. Reactor operation environmental information document

    Energy Technology Data Exchange (ETDEWEB)

    Haselow, J.S.; Price, V.; Stephenson, D.E.; Bledsoe, H.W.; Looney, B.B.

    1989-12-01

    The Savannah River Site (SRS) produces nuclear materials, primarily plutonium and tritium, to meet the requirements of the Department of Defense. These products have been formed in nuclear reactors that were built during 1950--1955 at the SRS. K, L, and P reactors are three of five reactors that have been used in the past to produce the nuclear materials. All three of these reactors discontinued operation in 1988. Currently, intense efforts are being extended to prepare these three reactors for restart in a manner that protects human health and the environment. To document that restarting the reactors will have minimal impacts to human health and the environment, a three-volume Reactor Operations Environmental Impact Document has been prepared. The document focuses on the impacts of restarting the K, L, and P reactors on both the SRS and surrounding areas. This volume discusses the geology, seismology, and subsurface hydrology. 195 refs., 101 figs., 16 tabs.

  13. Reactor operation safety information document

    Energy Technology Data Exchange (ETDEWEB)

    1990-01-01

    The report contains a reactor facility description which includes K, P, and L reactor sites, structures, operating systems, engineered safety systems, support systems, and process and effluent monitoring systems; an accident analysis section which includes cooling system anomalies, radioactive materials releases, and anticipated transients without scram; a summary of onsite doses from design basis accidents; severe accident analysis (reactor core disruption); a description of operating contractor organization and emergency planning; and a summary of reactor safety evolution. (MB)

  14. REACTOR FUEL ELEMENTS TESTING CONTAINER

    Science.gov (United States)

    Whitham, G.K.; Smith, R.R.

    1963-01-15

    This patent shows a method for detecting leaks in jacketed fuel elements. The element is placed in a sealed tank within a nuclear reactor, and, while the reactor operates, the element is sparged with gas. The gas is then led outside the reactor and monitored for radioactive Xe or Kr. (AEC)

  15. Nuclear Reactors and Technology

    Energy Technology Data Exchange (ETDEWEB)

    Cason, D.L.; Hicks, S.C. [eds.

    1992-01-01

    This publication Nuclear Reactors and Technology (NRT) announces on a monthly basis the current worldwide information available from the open literature on nuclear reactors and technology, including all aspects of power reactors, components and accessories, fuel elements, control systems, and materials. This publication contains the abstracts of DOE reports, journal articles, conference papers, patents, theses, and monographs added to the Energy Science and Technology Database during the past month. Also included are US information obtained through acquisition programs or interagency agreements and international information obtained through the International Energy Agency`s Energy Technology Data Exchange or government-to-government agreements. The digests in NRT and other citations to information on nuclear reactors back to 1948 are available for online searching and retrieval on the Energy Science and Technology Database and Nuclear Science Abstracts (NSA) database. Current information, added daily to the Energy Science and Technology Database, is available to DOE and its contractors through the DOE Integrated Technical Information System. Customized profiles can be developed to provide current information to meet each user`s needs.

  16. WATER BOILER REACTOR

    Science.gov (United States)

    King, L.D.P.

    1960-11-22

    As its name implies, this reactor utilizes an aqueous solution of a fissionable element salt, and is also conventional in that it contains a heat exchanger cooling coil immersed in the fuel. Its novelty lies in the utilization of a cylindrical reactor vessel to provide a critical region having a large and constant interface with a supernatant vapor region, and the use of a hollow sleeve coolant member suspended from the cover assembly in coaxial relation with the reactor vessel. Cool water is circulated inside this hollow coolant member, and a gap between its outer wall and the reactor vessel is used to carry off radiolytic gases for recombination in an external catalyst chamber. The central passage of the coolant member defines a reflux condenser passage into which the externally recombined gases are returned and condensed. The large and constant interface between fuel solution and vapor region prevents the formation of large bubbles and minimizes the amount of fuel salt carried off by water vapor, thus making possible higher flux densities, specific powers and power densities.

  17. MULTISTAGE FLUIDIZED BED REACTOR

    Science.gov (United States)

    Jonke, A.A.; Graae, J.E.A.; Levitz, N.M.

    1959-11-01

    A multistage fluidized bed reactor is described in which each of a number of stages is arranged with respect to an associated baffle so that a fluidizing gas flows upward and a granular solid downward through the stages and baffles, whereas the granular solid stopsflowing downward when the flow of fluidizing gas is shut off.

  18. Fusion reactor materials

    Energy Technology Data Exchange (ETDEWEB)

    none,

    1989-01-01

    This paper discuses the following topics on fusion reactor materials: irradiation, facilities, test matrices, and experimental methods; dosimetry, damage parameters, and activation calculations; materials engineering and design requirements; fundamental mechanical behavior; radiation effects; development of structural alloys; solid breeding materials; and ceramics.

  19. Integral Fast Reactor concept

    Energy Technology Data Exchange (ETDEWEB)

    Till, C.E.; Chang, Y.I.

    1986-01-01

    The Integral Fast Reactor (IFR) is an innovative LMR concept, being developed at Argonne National Laboratory, that fully exploits the inherent properties of liquid metal cooling and metallic fuel to achieve breakthroughs in economics and inherent safety. This paper describes key features and potential advantages of the IFR concept, technology development status, fuel cycle economics potential, and future development path.

  20. The First Reactor.

    Science.gov (United States)

    Department of Energy, Washington, DC.

    On December 2, 1942, in a racquet court underneath the West Stands of Stagg Field at the University of Chicago, a team of scientists led by Enrico Fermi created the first controlled, self-sustaining nuclear chain reaction. This updated and revised story of the first reactor (or "pile") is based on postwar interviews (as told to Corbin…

  1. Thermal Reactor Safety

    Energy Technology Data Exchange (ETDEWEB)

    1980-06-01

    Information is presented concerning fire risk and protection; transient thermal-hydraulic analysis and experiments; class 9 accidents and containment; diagnostics and in-service inspection; risk and cost comparison of alternative electric energy sources; fuel behavior and experiments on core cooling in LOCAs; reactor event reporting analysis; equipment qualification; post facts analysis of the TMI-2 accident; and computational methods.

  2. Chromatographic and Related Reactors.

    Science.gov (United States)

    1988-01-07

    special information about effects of surface heteroge- neity in the methanation reaction. Studies of an efficient multicolumn assembly for measuring...of organic basic catalysts such as pyridine and 4-methylpicoline. It was demonstrated that the chromatographic reactor gave special information about...Programmed Reaction to obtain special information about surface heterogeneity in the methanation reaction. Advantages of stopped flow over steady state

  3. New concepts for shaftless recycle reactors

    Energy Technology Data Exchange (ETDEWEB)

    Berty, J.M.; Berty, I.J.

    1987-01-01

    Berty Reaction Engineers, Ltd. (BREL) is developing two new laboratory recycle reactors, the ROTOBERTY and the TURBOBERTY. These new reactors are basically improved versions of the original Berty reactor. To understand why the reactors have the features that they do, it is first necessary to briefly review laboratory reactors in general and specifically the original Berty reactor.

  4. Brazilian multipurpose reactor

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2014-07-01

    The Brazilian Multipurpose Reactor (RMB) Project is an action of the Federal Government, through the Ministry of Science Technology and Innovation (MCTI) and has its execution under the responsibility of the Brazilian National Nuclear Energy Commission (CNEN). Within the CNEN, the project is coordinated by the Research and Development Directorate (DPD) and developed through research units of this board: Institute of Nuclear Energy Research (IPEN); Nuclear Engineering Institute (IEN); Centre for Development of Nuclear Technology (CDTN); Regional Center of Nuclear Sciences (CRCN-NE); and Institute of Radiation Protection and Dosimetry (IRD). The Navy Technological Center in Sao Paulo (CTMSP) and also the participation of other research centers, universities, laboratories and companies in the nuclear sector are important and strategic partnerships. The conceptual design and the safety analysis of the reactor and main facilities, related to nuclear and environmental licensing, are performed by technicians of the research units of DPD / CNEN. The basic design was contracted to engineering companies as INTERTHECNE from Brazil and INVAP from Argentine. The research units from DPD/CNEN are also responsible for the design verification on all engineering documents developed by the contracted companies. The construction and installation should be performed by specific national companies and international partnerships. The Nuclear Reactor RMB will be a open pool type reactor with maximum power of 30 MW and have the OPAL nuclear reactor of 20 MW, built in Australia and designed by INVAP, as reference. The RMB reactor core will have a 5x5 configuration, consisting of 23 elements fuels (EC) of U{sub 3}Si{sub 2} dispersion-type Al having a density of up to 3.5 gU/cm{sup 3} and enrichment of 19.75% by weight of {sup 23{sup 5}}U. Two positions will be available in the core for materials irradiation devices. The main objectives of the RMB Reactor and the other nuclear and radioactive

  5. Modeling Chemical Reactors I: Quiescent Reactors

    CERN Document Server

    Michoski, C E; Schmitz, P G

    2010-01-01

    We introduce a fully generalized quiescent chemical reactor system in arbitrary space $\\vdim =1,2$ or 3, with $n\\in\\mathbb{N}$ chemical constituents $\\alpha_{i}$, where the character of the numerical solution is strongly determined by the relative scaling between the local reactivity of species $\\alpha_{i}$ and the local functional diffusivity $\\mathscr{D}_{ij}(\\alpha)$ of the reaction mixture. We develop an operator time-splitting predictor multi-corrector RK--LDG scheme, and utilize $hp$-adaptivity relying only on the entropy $\\mathscr{S}_{\\mathfrak{R}}$ of the reactive system $\\mathfrak{R}$. This condition preserves these bounded nonlinear entropy functionals as a necessarily enforced stability condition on the coupled system. We apply this scheme to a number of application problems in chemical kinetics; including a difficult classical problem arising in nonequilibrium thermodynamics known as the Belousov-Zhabotinskii reaction where we utilize a concentration-dependent diffusivity tensor $\\mathscr{D}_{ij}(...

  6. Alternative approaches to fusion. [reactor design and reactor physics for Tokamak fusion reactors

    Science.gov (United States)

    Roth, R. J.

    1976-01-01

    The limitations of the Tokamak fusion reactor concept are discussed and various other fusion reactor concepts are considered that employ the containment of thermonuclear plasmas by magnetic fields (i.e., stellarators). Progress made in the containment of plasmas in toroidal devices is reported. Reactor design concepts are illustrated. The possibility of using fusion reactors as a power source in interplanetary space travel and electric power plants is briefly examined.

  7. Reactor monitoring using antineutrino detectors

    Science.gov (United States)

    Bowden, N. S.

    2011-08-01

    Nuclear reactors have served as the antineutrino source for many fundamental physics experiments. The techniques developed by these experiments make it possible to use these weakly interacting particles for a practical purpose. The large flux of antineutrinos that leaves a reactor carries information about two quantities of interest for safeguards: the reactor power and fissile inventory. Measurements made with antineutrino detectors could therefore offer an alternative means for verifying the power history and fissile inventory of a reactor as part of International Atomic Energy Agency (IAEA) and/or other reactor safeguards regimes. Several efforts to develop this monitoring technique are underway worldwide.

  8. Reactor vessel support system. [LMFBR

    Science.gov (United States)

    Golden, M.P.; Holley, J.C.

    1980-05-09

    A reactor vessel support system includes a support ring at the reactor top supported through a box ring on a ledge of the reactor containment. The box ring includes an annular space in the center of its cross-section to reduce heat flow and is keyed to the support ledge to transmit seismic forces from the reactor vessel to the containment structure. A coolant channel is provided at the outside circumference of the support ring to supply coolant gas through the keyways to channels between the reactor vessel and support ledge into the containment space.

  9. Modelos flexibles de selección de personal basados en la valoración de competencias.

    Directory of Open Access Journals (Sweden)

    Liern Carrión, Vicente

    2008-01-01

    Full Text Available Las decisiones que toman los directivos respecto a la selección de personalcondicionan fuertemente el éxito de la empresa, pues si los empleados son elegidoscorrectamente suponen una fuente de ventaja competitiva. En este trabajo presentamosalgunos modelos fuzzy de selección de personal basados en la gestión por competencias.y la comparación con las valoraciones que la empresa considera óptimas en cadacompetencia (candidato ideal. Presentamos un algoritmo que permiten establecer unaordenación, incluso cuando el candidato ideal sólo ha sido valorado parcialmente.

  10. Aprendizaje Basado en Problemas tutorizado en asignaturas de Grado y Máster en Ingenierías Industriales

    OpenAIRE

    Lucas Yagüe, Susana; García Cubero, María Teresa; Coca Sanz, Mónica; González Benito, Gerardo; Garrido Casado, Asunción; Cartón López, Ángel; Urueña Alonso, Miguel Ángel; Villaverde Gómez, Santiago

    2017-01-01

    Una nueva metodología docente que combina el aprendizaje basado en problemas (ABP) y la tutoría colectiva ha sido aplicada con éxito a nivel de grado en la asignatura de Introducción a la Ingeniería Química y a nivel de máster en la asignatura Formación Complementaria en Ingeniería Química y Termofluidos. Ambas asignaturas comparten como competencia específica los conocimientos sobre los balances de materia y energía de procesos químicos industriales. Los estudiantes resuelven de forma pautad...

  11. Sistema de evaluación en Aprendizaje Basado en Problemas (ABP) de estudiantes de nutrición

    OpenAIRE

    Ruiz Cerrillo, Salvador

    2017-01-01

    El presente artículo tiene como objetivo proponer un sistema de evaluación para el ABP en alumnos de Nutrición, el cual se concluye que debe ser de tipo integral, incluyendo a los actores del fenómeno educativo, una diversidad de instrumentos y enfoques interpretativos, tratándose no sólo de una evaluación formal sino también de una con un carácter informal.Palabras Clave: Aprendizaje Basado en Problemas (ABP), Evaluación, Nutrición, Evaluación formal.Problem-Based Learning Assessment (PBL) o...

  12. MÉTODO DE DISEÑO SÍSMICO BASADO EN DESPLAZAMIENTOS PARA MARCOS DE CONCRETO REFORZADO

    OpenAIRE

    2013-01-01

    Se presenta un método novedoso de diseño sísmico basado en desplazamientos para marcos de concreto reforzado. Su formulación se sustenta en el concepto de sistema de referencia, el cual radica en la caracterización de la respuesta estructural mediante las propiedades elásticas e inelásticas del modo fundamental. El método propuesto consiste en la construcción de una curva bilineal de seudoaceleracion vs desplazamientos espectrales, denominada curva de comportamiento; el desplazamiento de flue...

  13. Software basado en el método de elementos finitos para la enseñanza de electromagnetismo

    OpenAIRE

    Sánchez-Repila, Diego; García Castillo, Luís E.

    2005-01-01

    Se presenta una herramienta software para la enseñanza de electromagnetismo. Ésta, permite analizar una gran variedad de fenómenos electromagnéticos en las bandas de microondas y ondas milimétricas. Dos aspectos muy cuidados en el desarrollo han sido la portabilidad y la difusión, estando disponible para sistemas operativos Linux y Windows y en diferentes idiomas. El interfaz gráfico, está basado en un pre-post procesador de propósito general para análisis computaci...

  14. Aprendizaje basado en proyectos en Diseño y Construcción de Sistemas Digitales

    OpenAIRE

    Ibarra Lasa, Amaya; Amuchastegui Uriarte, Carlos; Arruti Illarramendi, Andoni; Etxeberria Uztarroz, Izaskun

    2013-01-01

    Duración (en horas): Más de 50 horas. Destinatario: Estudiante y Docente Presentamos una aplicación de la metodología de Aprendizaje Basado en Proyectos (ABP-PBL Project Based Learning) a la asignatura de Diseño y Construcción de Sistemas Digitales. Esta metodología se aplica al curso completo y consiste en proponer a los estudiantes un concurso en el que tienen que presentar el diseño de un sistema digital para una aplicación real de complejidad media-alta que han de construir y verifi...

  15. Desarrollo de algoritmos de procesamiento de imágenes basados en "Operadores de Ventana" sobre una FPGA

    OpenAIRE

    Quijano, Antonio Adrián; Rapallini, José Antonio; Aróztegui, Walter J.; Osio, Jorge R.

    2011-01-01

    Con el avance de la tecnología las FPGAs se han convertido en una herramienta indispensable en el diseño rápido y eficiente de proyectos que requieren procesamiento digital y lógica programable. Es por eso que se ha convertido en la principal herramienta para la implementación de los algoritmos de procesamiento Digital de imágenes presentados en este trabajo [1]. Debido a la gran cantidad de algoritmos para procesamiento de imágenes basados en los Operadores de Ventana, se llega a la necesida...

  16. Benidorm Tierra Adentro: un nuevo producto turístico basado en las dinámicas de complementariedad territorial

    OpenAIRE

    Díez Santo, Daniel

    2008-01-01

    Propuesta enviada al concurso de ideas del XII Foro Internacional de Turismo de Benidorm. RETAR AL FUTURO: LA REINVENCIÓN DE LOS DESTINOS TURÍSTICOS (23-24 de octubre de 2008). Benidorm Tierra Adentro es una propuesta para el desarrollo de un nuevo producto turístico basado en las dinámicas de complementariedad territorial litoral-interior. La movilización de flujos turísticos establece relaciones simbióticas entre Benidorm y los municipios del interior provincial, aportando beneficios dir...

  17. PROCEDIMIENTO DE DISEÑO SISMICO MULTINIVEL BASADO EN DESPLAZAMIENTO PARA ESTRUCTURAS A BASE DE MARCOS DE CONCRETO REFORZADO

    OpenAIRE

    José E. Barradas Hernández; A. Gustavo Ayala Milián

    2014-01-01

    Se propone un procedimiento de diseño sísmico multinivel basado en desplazamientos, aplicable a estructuras conformadas por marcos de concreto reforzado. Mediante la aplicación de este procedimiento se satisfacen simultáneamente los requisitos de rigidez para el estado límite de servicio, de resistencia para un estado límite auxiliar, denominado de fluencia incipiente, y la capacidad de deformación inelástica para el estado límite de prevención del colapso. El procedimiento se fundamenta en c...

  18. Beneficios del tratamiento basado en la kinesioterapia para el síndrome femóro-patelar

    OpenAIRE

    Roselli, Roberto

    2015-01-01

    Introducción: Las alteraciones femororrotulianas son una de las más frecuentes en traumatología, provocando dolor anterior en la rodilla y disminución funcional. Su tratamiento, es una cuestión compleja y en constante evolución hasta nuestros días. Durante mucho tiempo, los tratamientos recomendados se basaban en experiencias personales o tradiciones. Resulta determinante establecer un protocolo de rehabilitación adecuado, basado en los hallazgos de una completa anamnesis y una...

  19. ALGORITMO PARA EL APRENDIZAJE DE REGLAS DE CLASIFICACION BASADO EN LA TEORÍA DE LOS CONJUNTOS APROXIMADOS EXTENDIDA

    Directory of Open Access Journals (Sweden)

    YAIMA FILIBERTO

    2011-01-01

    Full Text Available Los conjuntos aproximados han demostrado ser efectivos para desarrollar técnicas de aprendizaje automático, entre ellos métodos para el descubrimiento de reglas de clasificación. En este trabajo se presenta un algoritmo para generar reglas de clasificación basado en relaciones de similaridad, lo que permite que sea aplicable en casos donde los rasgos tienen dominio discreto o continuo. Los resultados experimentales muestran un desempeño satisfactorio en comparación con otros algoritmos conocidos como C4.5 y MODLEM.

  20. Aplicación del 'aprendizaje basado en problemas'en los estudio de Grado en Enfermería

    OpenAIRE

    2013-01-01

    Con el fin de mejorar la calidad docente universitaria, en esta investigación, se propuso utilizar metodologías activas como el Aprendizaje Basado en Problemas en la formación de los estudiantes de Grado en Enfermería. Este trabajo constituye un nuevo paso, mi planteamiento abordó una innovación educativa desde un ángulo nuevo, realizando las prácticas de aula de los estudiantes para agregar conocimiento sobre su utilidad en el proceso de enseñanza y aprendizaje en Enfermería. Se utilizó una ...

  1. Semiconductores orgánicos pi-conjugados basados en tiofeno. Un estudio teórico

    OpenAIRE

    García-Moreno, Gregorio

    2013-01-01

    En esta memoria se expone un estudio predictivo de propiedades de transporte de carga a nivel molecular para una serie de semiconductores orgánicos basados en anillos de tiofeno (derivados del politiofeno, poli(ariletinil-tienoacenos y sistemas discóticos) haciendo uso de una metodología mecanocuántica (cálculos ab initio, DFT y semiempíricos). Los resultados aquí expuestos nos ayudarán a entender la relación estructura­ propiedad y proponer modificaciones de ...

  2. Diseño y construcción de un detector de metales basado en un microcontrolador.

    OpenAIRE

    Martínez Cantón, Carlos

    2016-01-01

    En el proyecto se diseñará y construirá un detector de metales basado en un microcontrolador de la familia PIC del fabricante Microchip. La detección del campo magnético se realizará en base a un sensor del tipo MPU6050. La comunicación entre el usuario y el dispositivo se realizará a través de un teléfono móvil android mediante tecnología bluetooth.

  3. DESARROLLO DEL PENSAMIENTO CRÍTICO EN AMBIENTES DE APRENDIZAJE BASADO EN PROBLEMAS EN ESTUDIANTES DE EDUCACIÓN SUPERIOR

    OpenAIRE

    Silvia Lizett Olivares Olivares; Yolanda Heredia Escorza

    2012-01-01

    El Aprendizaje Basado en Problemas (abp) es una técnica didáctica que busca promover el pensamiento crítico. El presente estudio consistió en comparar los niveles de pensamiento crítico obtenidos con el Test California de Destrezas de Pensamiento Crítico (cctst-2000) de Facione (2000) por estudiantes de salud formados con abp con alumnos de la misma escuela que no fueron expuestos a esta técnica didáctica. Se compararon los resultados entre estudiantes de primer ingreso y candidatos a graduac...

  4. Software basado en el método de elementos finitos para la enseñanza de electromagnetismo

    OpenAIRE

    Sánchez-Repila, Diego; García Castillo, Luís E.

    2005-01-01

    Se presenta una herramienta software para la enseñanza de electromagnetismo. Ésta, permite analizar una gran variedad de fenómenos electromagnéticos en las bandas de microondas y ondas milimétricas. Dos aspectos muy cuidados en el desarrollo han sido la portabilidad y la difusión, estando disponible para sistemas operativos Linux y Windows y en diferentes idiomas. El interfaz gráfico, está basado en un pre-post procesador de propósito general para análisis computaci...

  5. Simulación de sistemas Multi-Agente mediante un esquema Monte Carlo basado en ecuaciones diferenciales ordinarias

    OpenAIRE

    Zulueta Guerrero, Ekaitz; González González, Asier; Lopez Guede, José Manuel; Calvo Gordillo, Isidro

    2011-01-01

    [ES] En este trabajo se expone una metodología para modelar un sistema Multi-Agente (SMA), para que sea equivalente a un sistema de Ecuaciones Diferenciales Ordinarias (EDO), mediante un esquema basado en el método de Monte Carlo. Se muestra que el SMA puede describir con mayor riqueza modelos de sistemas dinámicos con variables cuantificadas discretas. Estos sistemas son muy acordes con los sistemas biológicos y fisiológicos, como el modelado de poblaciones o el modelado de enfermedades epid...

  6. Programas preventivos basados en fluoruros en preescolares de riesgo social con altos índices de caries

    OpenAIRE

    Fernández, Claudia Nélida

    2011-01-01

    En Mendoza se realizó un estudio clínico de intervención, prospectivo de dos años, dirigido a preescolares en riesgo social con alto índice de caries con el objetivo de evaluar la eficacia y efectividad de un programa preventivo basado en fluoruros. El programa preventivo se basó en acciones de educación para la salud, enseñanza de técnicas de higiene bucal y aplicación tópica de flúor fosfato acidulado realizadas dos veces durante e...

  7. Modelo director no paramétrico de amortiguador magneto-reológico basado en redes neuronales

    OpenAIRE

    Muñoz Águila, Felipe Borja

    2012-01-01

    El objetivo de este Proyecto Fin de Carrera es el de desarrollar un modelo de amortiguador magneto-reológico basado en redes neuronales que prediga su comportamiento no lineal e hiterético. Se pretende encontrar el algoritmo adecuado para relacionar amplitud, frecuencia y corriente con la fuerza; para ello se dispone de una serie de datos de partida con los que se procederá de la siguiente forma: · Análisis de los datos obtenidos en los ensayos experimentales. · Diseño de la red neuronal arti...

  8. MD2 : sistema de búsqueda y composición de contenidos basados en IMS QTI

    OpenAIRE

    2009-01-01

    Los contenidos educativos en formato digital, son una parte fundamental dentro de los nuevos modelos de enseñanza basados en e-learning. El concepto de e-learning se define de muchas formas diferentes fundamentalmente debido a que los actores que de él hacen uso son muy diversos, cada uno con su idiosincrasia y su ámbito de aplicación. Desde la perspectiva de su concepción y desarrollo como herramienta formativa, los sistemas de e-learning tienen una dualidad pedagógica y tecnológica. Pedagóg...

  9. Methanogenesis in Thermophilic Biogas Reactors

    DEFF Research Database (Denmark)

    Ahring, Birgitte Kiær

    1995-01-01

    Methanogenesis in thermophilic biogas reactors fed with different wastes is examined. The specific methanogenic activity with acetate or hydrogen as substrate reflected the organic loading of the specific reactor examined. Increasing the loading of thermophilic reactors stabilized the process...... as indicated by a lower concentration of volatile fatty acids in the effluent from the reactors. The specific methanogenic activity in a thermophilic pilot-plant biogas reactor fed with a mixture of cow and pig manure reflected the stability of the reactor. The numbers of methanogens counted by the most...... against Methanothrix soehngenii or Methanothrix CALS-I in any of the thermophilic biogas reactors examined. Studies using 2-14C-labeled acetate showed that at high concentrations (more than approx. 1 mM) acetate was metabolized via the aceticlastic pathway, transforming the methyl-group of acetate...

  10. Perfiles de personas con deficiencia mental basados en las funciones motrices gruesas

    Directory of Open Access Journals (Sweden)

    Isabel María FERRÁNDIZ VINDEL

    2009-11-01

    Full Text Available RESUMEN: El propósito de este estudio ha sido identificar posibles subtipos de alumnos con Deficiencia Mental basados en funciones motrices gmesas. Se seleccionó un grupo de alumnos, de un centro específico de Deficiencia Mental, que no presentaron deficiencias motóricas asociadas y se les administraron los subtests de motricidad gruesa del «Test Bruininks-Ozeretsky para medir la eficacia motriz». Los cuatro subtipos resultantes mostraron diferentes perfiles de desarrollo motor. A partir de estos resultados, se recomienda diseñar programas específicos que intenten paliar los trastornos motrices gruesos, analizados para cada uno de los subtipos hallados, y realizar adaptaciones curriculares pertinentes, teniendo en cuenta los perfiles motrices estudiados.ABSTRACT: The goal of this work was to identify some different cathegories of mental retarded people, depending on their gross motor functioning. A group of mental retarded people was selected from a special education school. None of theese students presented any associated motor deficiency. The gross motor subtests from the Bruininks-Ozeretsky test were administered in order to evaluate the motor eficiency of these mental retarded people. The resulting four cathegories showed different motor development profiles. From theese results it's recommended to design curricula-based intended to amiliorate the specific gross motor deficits of each group and making didactical schedules taking into account the motor profiles studied.RESUME: Le propos de cette étude est identifier possibles subtypes d'élèves avec déficience mental basses en fonctions motrices grosses. On a selectioné un groupe d'élèves dans un centre especifique d'insuffisance mental qui ne présentent pas insuffisance motoriques associés, on les a passé les subtests de motricité grosse du test Bruininks-Ozeretsky pour mesurer l'efficacité motrice. Les quattre subtypes resultants montrent des différents profils du

  11. Aprendizaje basado en proyectos aplicados al entorno del laboratorio de inmunología

    Directory of Open Access Journals (Sweden)

    Javier Jiménez Jiménez

    2013-11-01

    Full Text Available En la aplicación de metodologías participativas en el entorno de laboratorio, son muchos los recursos educativos que han mostrado su utilidad para la adquisición de competencias, tanto genéricas (trabajo colaborativo, autoaprendizaje como específicas (razonamiento clínico, reconocimiento de mecanismos relacionados con fundamentos científicos. En este contexto, en la asignatura “Estructura y función de la sangre y del sistema inmunitario” de segundo curso del Grado en Medicina de la UIC se ha introducido una estrategia de aprendizaje basada en proyectos (ABP, que ha permitido dar sentido a la adquisición de conocimientos y habilidades con el fin específico de solucionar un caso clínico. Para ello, los estudiantes, en grupos de tres, se enfrentan al caso debiendo analizar, orientar y seleccionar una prueba de laboratorio que permita confirmar un diagnóstico. El alumno dispone de conexión a internet para la obtención de la base teórica del caso planteado y el apoyo de un tutor para orientar su investigación. Una vez decidida la prueba a realizar dispone de la muestra biológica del paciente, de los kits diagnósticos apropiados y de los protocolos necesarios para llevarlos a cabo. El alumno, con ayuda del tutor, realiza el test diagnóstico que ha seleccionado, obtiene los resultados, los interpreta y con la información obtenida emite un diagnóstico del caso clínico propuesto. Posteriormente los grupos de alumnos exponen cada caso clínico al resto de sus compañeros. En la presente comunicación se muestra con más detalle la realización de este tipo de “Aprendizaje Basado en Proyecto”, y se discute la aceptación que ha tenido por parte de los alumnos, los resultados académicos obtenidos y el grado de adquisición de las competencias trabajadas.

  12. Modelo del Costo Basado en la Actividad aplicado a consultas por trazadores de enfermedades cardiovasculares

    Directory of Open Access Journals (Sweden)

    Marteau Silvia A.

    2001-01-01

    Full Text Available OBJETIVO: Hacer un análisis de costos, de la atención médica en consultas externas, mediante la metodología del Costo Basado en la Actividad (ABC, por sus siglas en inglés y en relación con eventos trazadores de enfermedades cardiovasculares de origen isquémico en las instituciones del sector público. MATERIAL Y MÉTODOS: El estudio se basó en consultas por enfermedades o eventos trazadores (n=290 y no trazadores (n=1 710, de una muestra de 2 000 consultas de primera vez de un hospital zonal general de agudos (San Roque de Gonnet, de la provincia de Buenos Aires, Argentina, y se realizó de abril a octubre de 1998. El costo se evaluó con la metodología del ABC. RESULTADOS: El mejoramiento de las actividades de atención en el servicio de Clínica Médica conllevaría un ahorro sustancial en los costos indirectos, equivalente a un porcentaje promedio de 7.11 sobre los productos definidos como consultas por hipertensión arterial (HTA, dislipidemia y diabetes. El ahorro total en el costo unitario por producto que se produciría si se eliminaran las actividades mencionadas, estaría en el orden de 11.78% para el producto HTA, de 13.96% para dislipidemia, de 19.05% para diabetes y de 11.45% para las enfermedades no trazadores. Se asignó o se gastó ineficientemente 66.26% de los costos totales indirectos correspondientes al producto dislipidemia y 61.80% de los correspondientes a diabetes. El costo unitario total de las consultas en el servicio de Clínica Médica, según el método tradicional, es de $22.98, valor que en algunos casos está muy por debajo del costo obtenido a partir del método ABC aplicado en este estudio. CONCLUSIONES: Es necesario trabajar en el rediseño del proceso de atención para evaluar las actividades que no agreguen valor al mismo; éstas únicamente generan molestias y demoras al paciente y provocan ineficiencias en el sistema, dado que se asignan recursos a actividades que no optimizan la gestión y, como

  13. Aprendizaje basado en problemas: Metodología de aprendizaje centrada en el estudiante

    Directory of Open Access Journals (Sweden)

    V. Tórtora

    2013-11-01

    Full Text Available 8vas Jornadas de la Sociedad de Bioquímica y Biología Molecular. 12 y 13 de setiembre 2013. SIMPOSIO VI: “Educación en Ciencias” Coordinadores: María Noel Álvarez, Andrea MedeirosLa reforma del plan de estudios de la carrera de Doctor en Medicina implicó, entre outras modificaciones, la incorporación de nuevas metodologías de enseñanza y aprendizaje. Una de ellas es la de “aprendizaje basado en problemas” (ABP, que se caracteriza por colocar al estudiante en el centro del proceso de aprendizaje, promoviendo que este sea significativo, además de desarrollar habilidades y competencias indispensables en el ejercicio profesional. El ABP se realiza en grupos de aproximadamente 20 estudiantes, en dos instancias. El problema es diseñado por un equipo docente interdisciplinario, en función a los objetivos del curso. En la primera instancia se presenta el problema y los estudiantes discuten en función de sus conocimientos previos, identificando las áreas de saber y de no saber sobre el problema, e intentan plantear hipótesis explicativas sobre las dificultades identificadas. Lugo deben determinar qué competencias y nuevos conocimientos necesitan para comprobarlas. Este proceso es realizado de manera autónoma por los estudiantes, bajo la dirección de un docente tutor que actúa como facilitador del aprendizaje. Entre una instancia y otra buscan la información necesaria para lograr los objetivos de estudio definidos por el grupo, y regresan al problema en la segunda instancia. La información encontrada es compartida entre los integrantes del grupo, mediante discusión en foros en la plataforma de aprendizaje virtual (EVA y durante las clases presenciales, haciendo que el aprendizaje sea además cooperativo. En esta presentación se expondrá esta metodología de trabajo junto con un ejemplo de un problema específico con objetivos de bioquímica.En esta presentación se expondrá esta metodología de trabajo junto con un ejemplo

  14. TRANSFORMACIÓN DE ESQUEMAS RELACIONALES ORIENTADOS A OBJETOS: UN ENFOQUE BASADO EN EL OBJETO

    Directory of Open Access Journals (Sweden)

    Roberto Sepúlveda Lima

    2007-05-01

    Full Text Available

     

    Las innovaciones en la industria de las bases de datos son permanentes. Entre las más recientes , se tienen las bases de datos distribuidas, el paradigma orientado a objetos (OO, y la tecnología XML*. Todas tienen un objetivo común, mejorar la calidad de los servicios. Por otro lado se observa que la inmensa mayoría de los sistemas de bases de datos (BD actuales tienen una estructura relacional y aún siguen almacenando voluminosas informaciones de sumo valor para las organizaciones. La transformación de los esquemas de bases de datos permanecen siendo un campo de investigación de primordial importancia, ya que se observan numerosas aplicaciones sometidas hoy en día a procesos de reingeniería. Aunque la industria de software ya ofrece algunas herramientas para automatizar este proceso, aún queda mucho por hacer. Y en este contexto, la comprensión del formalismo matemático y de la orientación de los enfoques propuestos no solo podría permitir una mejor comprensión de estos, sino también apoyar a la realización de trabajos futuros en este campo. El presente artículo describe un enfoque de transformación basado en el objeto y en cómo refinarlo mediante traducción de consultas SQL en código C++.

  15. Influencia del Saniamiento en Projectos Basados en el Complimiento de Criterios de Desenpeño.

    Directory of Open Access Journals (Sweden)

    Ana Júlia Ferreira Rocha

    2005-01-01

    Full Text Available Este artículo destaca la necesidad de estudios de Saneamiento del Medio, específicamente, acerca de la cuestión que se refiere al suelo, debido a la emigración de substancias poluentes provenientes de residuos sólidos urbanos a través del mismo. El estudio del saneamiento ambiental pretende satisfacer tanto la definición aceptada por la OMS (Organización mundial de la Salud, que plantea: "Es el control de los factores del medio físico del hombre que ejercen o pueden ejercer un efecto nocivo sobre su bienestar físico, mental y social", cuando la definición expresada por la Fundación Internacional, que establece: "Modo de vivir, calidad de vida expresada en condiciones de salubridad, con casa limpia, hacienda limpia, comercio limpio, industria limpia. Siendo un modo de vida, por el bien del pueblo, ser alimentado por el saber y crecer en las relaciones humanas, no solo como ideal, sino como obligación". Los resultados obtenidos en este estudio pueden ser adicionados al desarrollo de proyectos basados en la atención a criterios de desempeño, ya que todo proyecto, donde se hace notar la presencia de obras de Ingeniaría de Suelos e cujo objetivo sea el destino final de residuos sólidos urbanos, han demostrado que: en la Ingeniaría Civil, en su curso de graduación, adquiere conocimientos de saneamiento básico, pero no de Saneamiento del Medio, por eso, surge la necesidad de conocimientos de otros profesionales, entre ellos, los microbiólogos, que no han sido capaces de trasmitir para los ingenieros lo necesario; e los ingenieros, por outro lado, han sido incapaces de interpretar la función de los microbiólogos en los proyectos prácticos. Es aqui que el proyecto cumplirá tanto las exigencias de la Ingeniería de Suelos cuanto las exigencias de Saneamiento del Medio, llevando en consideración que en la actualidad, para que un proyecto sea considerado completo, deberá satisfacer los estudios de viabilidad técnica, econ

  16. El aprendizaje basado en problemas: De herejía artificial a res popularis

    Directory of Open Access Journals (Sweden)

    L.A. Branda

    Full Text Available La extensa implementación del aprendizaje basado en problemas (ABP en el proceso enseñanza-aprendizaje ha resultado en su transformación de herejía artificial a res popularis con la consecuente proliferación de publicaciones, libros y congresos sobre el tema. A menudo, esta avalancha de información, ha creado una confusión en la comprensión de qué es el ABP como estrategia de aprendizaje. Este artículo presenta al lector una definición de lo que se consideró que era el ABP y su extensión, además de incluir la resolución de problemas. Se indica la importancia de los objetivos de aprendizaje (resultados del aprendizaje y se presentan algunos pasos que se deben seguir en la preparación de situaciones/escenarios/problemas/casos. De forma general, se describen la evaluación de los estudiantes fundamentalmente formativa, basada en las observaciones hechas en las sesiones de tutoría, y la evaluación de carácter sumativo. La descripción de las etapas más comunes en el ABP tiene el propósito de indicar lo que los estudiantes pueden hacer y no que deben hacer. Si se consideran las limitaciones de recursos que tienen la mayoría de las instituciones que desean implementar el ABP, se describe la aplicación de esta estrategia en grupos grandes. Se discute el rol del tutor facilitador y se indican las características de sus intervenciones en un continuo que va desde jerárquica a facilitadora de la autonomía del estudiante en su aprendizaje. Este artículo finaliza con una reflexión sobre el aprendizaje autodirigido y su relación con el aprendizaje autorregulado.

  17. Compact fusion reactors

    CERN Document Server

    CERN. Geneva

    2015-01-01

    Fusion research is currently to a large extent focused on tokamak (ITER) and inertial confinement (NIF) research. In addition to these large international or national efforts there are private companies performing fusion research using much smaller devices than ITER or NIF. The attempt to achieve fusion energy production through relatively small and compact devices compared to tokamaks decreases the costs and building time of the reactors and this has allowed some private companies to enter the field, like EMC2, General Fusion, Helion Energy, Lawrenceville Plasma Physics and Lockheed Martin. Some of these companies are trying to demonstrate net energy production within the next few years. If they are successful their next step is to attempt to commercialize their technology. In this presentation an overview of compact fusion reactor concepts is given.

  18. MEANS FOR COOLING REACTORS

    Science.gov (United States)

    Wheeler, J.A.

    1957-11-01

    A design of a reactor is presented in which the fuel elements may be immersed in a liquid coolant when desired without the necessity of removing them from the reactor structure. The fuel elements, containing the fissionable material are in plate form and are disposed within spaced slots in a moderator material, such as graphite to form the core. Adjacent the core is a tank containing the liquid coolant. The fuel elements are mounted in spaced relationship on a rotatable shaft which is located between the core and the tank so that by rotation of the shaft the fuel elements may be either inserted in the slots in the core to sustain a chain reaction or immersed in the coolant.

  19. Integrated Microfluidic Reactors.

    Science.gov (United States)

    Lin, Wei-Yu; Wang, Yanju; Wang, Shutao; Tseng, Hsian-Rong

    2009-12-01

    Microfluidic reactors exhibit intrinsic advantages of reduced chemical consumption, safety, high surface-area-to-volume ratios, and improved control over mass and heat transfer superior to the macroscopic reaction setting. In contract to a continuous-flow microfluidic system composed of only a microchannel network, an integrated microfluidic system represents a scalable integration of a microchannel network with functional microfluidic modules, thus enabling the execution and automation of complicated chemical reactions in a single device. In this review, we summarize recent progresses on the development of integrated microfluidics-based chemical reactors for (i) parallel screening of in situ click chemistry libraries, (ii) multistep synthesis of radiolabeled imaging probes for positron emission tomography (PET), (iii) sequential preparation of individually addressable conducting polymer nanowire (CPNW), and (iv) solid-phase synthesis of DNA oligonucleotides. These proof-of-principle demonstrations validate the feasibility and set a solid foundation for exploring a broad application of the integrated microfluidic system.

  20. Reactor Neutrino Spectra

    OpenAIRE

    Hayes, A. C.; Vogel, Petr

    2016-01-01

    We present a review of the antineutrino spectra emitted from reactors. Knowledge of these spectra and their associated uncertainties is crucial for neutrino oscillation studies. The spectra used to date have been determined either by converting measured electron spectra to antineutrino spectra or by summing over all of the thousands of transitions that make up the spectra, using modern databases as input. The uncertainties in the subdominant corrections to β-decay plague both methods, and we ...

  1. REACTOR MODERATOR STRUCTURE

    Science.gov (United States)

    Greenstreet, B.L.

    1963-12-31

    A system for maintaining the alignment of moderator block structures in reactors is presented. Integral restraining grids are placed between each layer of blocks in the moderator structure, at the top of the uppermost layer, and at the bottom of the lowermost layer. Slots are provided in the top and bottom surfaces of the moderator blocks so as to provide a keying action with the grids. The grids are maintained in alignment by vertical guiding members disposed about their peripheries. (AEC)

  2. BOILER-SUPERHEATED REACTOR

    Science.gov (United States)

    Heckman, T.P.

    1961-05-01

    A nuclear power reactor of the type in which a liquid moderator-coolant is transformed by nuclear heating into a vapor that may be used to drive a turbo- generator is described. The core of this reactor comprises a plurality of freely suspended tubular fuel elements, called fuel element trains, within which nonboiling pressurized liquid moderator-coolant is preheated and sprayed through orifices in the walls of the trains against the outer walls thereof to be converted into vapor. Passage of the vapor ovcr other unwetted portions of the outside of the fuel elements causes the steam to be superheated. The moderatorcoolant within the fuel elements remains in the liqUid state, and that between the fuel elements remains substantiaily in the vapor state. A unique liquid neutron-absorber control system is used. Advantages expected from the reactor design include reduced fuel element failure, increased stability of operation, direct response to power demand, and circulation of a minimum amount of liquid moderatorcoolant. (A.G.W.)

  3. The OPAL reactor

    Energy Technology Data Exchange (ETDEWEB)

    Miller, R.; Irwin, T. [Australian Nuclear Science and Technology Organisation, Sydney (Australia); Ordonez, J.P. [INVAP SE, Bariloche (Argentina)

    2007-07-01

    The project to provide a replacement for Australia's HIFAR reactor began with governmental approval in September 1997 and reached its latest milestone with the achievement of the first full power operation of the OPAL reactor in November 2006. OPAL is a pool-type reactor with a thermal power of 20 MW and a fuel enrichment maximum of 20 per cent. This has been a successful project for both ANSTO (Australian Nuclear Science and Technology Organisation) and the contractor INVAP SE. This project was characterised by extensive interaction with the project's stake-holders during project definition and the use of a performance-based turnkey contract which gave the contractor the maximum opportunity to optimise the design to achieve performance and cost effectiveness. The contactor provided significant in-house resources as well as capacity to manage an international team of suppliers and sub-contractors. A key contributor to the project's successful outcomes has been the development and maintenance of an excellent working relationship between ANSTO and INVAP project teams. Commissioning was undertaken in accordance with the IAEA recommended stages. This paper presents the approaches used to define the project requirements, to choose the supplier and to deliver the project. The main results of hot commissioning are reviewed and the problems encountered examined. Operational experience since hot commissioning is also reviewed.

  4. Nuclear research reactors in Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Cota, Anna Paula Leite; Mesquita, Amir Zacarias, E-mail: aplc@cdtn.b, E-mail: amir@cdtn.b [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2011-07-01

    The rising concerns about global warming and energy security have spurred a revival of interest in nuclear energy, giving birth to a 'nuclear power renaissance' in several countries in the world. Particularly in Brazil, in the recent years, the nuclear power renaissance can be seen in the actions that comprise its nuclear program, summarily the increase of the investments in nuclear research institutes and the government target to design and build the Brazilian Multipurpose research Reactor (BMR). In the last 50 years, Brazilian research reactors have been used for training, for producing radioisotopes to meet demands in industry and nuclear medicine, for miscellaneous irradiation services and for academic research. Moreover, the research reactors are used as laboratories to develop technologies in power reactors, which are evaluated today at around 450 worldwide. In this application, those reactors become more viable in relation to power reactors by the lowest cost, by the operation at low temperatures and, furthermore, by lower demand for nuclear fuel. In Brazil, four research reactors were installed: the IEA-R1 and the MB-01 reactors, both at the Instituto de Pesquisas Energeticas Nucleares (IPEN, Sao Paulo); the Argonauta, at the Instituto de Engenharia Nuclear (IEN, Rio de Janeiro) and the IPR-R1 TRIGA reactor, at the Centro de Desenvolvimento da Tecnologia Nuclear (CDTN, Belo Horizonte). The present paper intends to enumerate the characteristics of these reactors, their utilization and current academic research. Therefore, through this paper, we intend to collaborate on the BMR project. (author)

  5. Nuclear research reactors in Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Cota, Anna Paula Leite; Mesquita, Amir Zacarias, E-mail: aplc@cdtn.b, E-mail: amir@cdtn.b [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2011-07-01

    The rising concerns about global warming and energy security have spurred a revival of interest in nuclear energy, giving birth to a 'nuclear power renaissance' in several countries in the world. Particularly in Brazil, in the recent years, the nuclear power renaissance can be seen in the actions that comprise its nuclear program, summarily the increase of the investments in nuclear research institutes and the government target to design and build the Brazilian Multipurpose research Reactor (BMR). In the last 50 years, Brazilian research reactors have been used for training, for producing radioisotopes to meet demands in industry and nuclear medicine, for miscellaneous irradiation services and for academic research. Moreover, the research reactors are used as laboratories to develop technologies in power reactors, which are evaluated today at around 450 worldwide. In this application, those reactors become more viable in relation to power reactors by the lowest cost, by the operation at low temperatures and, furthermore, by lower demand for nuclear fuel. In Brazil, four research reactors were installed: the IEA-R1 and the MB-01 reactors, both at the Instituto de Pesquisas Energeticas Nucleares (IPEN, Sao Paulo); the Argonauta, at the Instituto de Engenharia Nuclear (IEN, Rio de Janeiro) and the IPR-R1 TRIGA reactor, at the Centro de Desenvolvimento da Tecnologia Nuclear (CDTN, Belo Horizonte). The present paper intends to enumerate the characteristics of these reactors, their utilization and current academic research. Therefore, through this paper, we intend to collaborate on the BMR project. (author)

  6. Modelo de Awareness Basado en Topologías de Interacción para Espacios Virtuales de Trabajo Colaborativo

    Directory of Open Access Journals (Sweden)

    Edwin Alexander Herrera Saavedra

    2014-08-01

    Full Text Available En un sistema de trabajo colaborativo un grupo de usuarios puede realizar actividades combinando sus capacidades y trabajo para conseguir un determinado objetivo, para esto los miembros del grupo tienen que estar al tanto sobre el estado, cambios y las acciones que otros miembros del grupo están realizando, este tipo de información se conoce como “Información Awareness”. Estos procesos de colaboración han demostrado ser complejos de soportar y desarrollar. Dado esto se han creado varios tipos de awareness tratando de responder como soportar particularidades dentro de los sistemas, pero no existe un modelo general basado en la posibles formas grupales de interacción que sirva como guía en la construcción de awareness. En ese contexto esta investigación propone un modelo de awareness basado en interacciones grupales en los CSCW asociando la información de awareness adecuada para cada topología de interacción. Esto permitirá dar un mejor soporte a la información de tipo awareness en aplicaciones colaborativas.

  7. Reasoning based in cases applied to diagnosis of electric generators; Razonamiento basado en casos aplicado al diagnostico de generadores electricos

    Energy Technology Data Exchange (ETDEWEB)

    De la Torre Vega, H. Octavio; Garcia Tevillo, Arturo; Campuzano Martinez, Roberto [Instituto de Investigaciones Electricas, Temixco, Morelos (Mexico); Lopez Azamar, Ernesto [Comision Federal de Electricidad (Mexico)

    2000-07-01

    The development of a system for the diagnosis of electrical generators that apply techniques of artificial intelligence, is presented, as it is the reasoning based on cases, to support the work of the diagnosis engineer. This system is part of a system called CADIS, dedicated to the diagnosis of electrical generators out of line and reason of previous articles. In this occasion the characteristics of the reasoning module based on experiences (SirBE) are emphasized, indicating how to make a diagnosis using similar cases and how to edit the system base of experience, using the interactive editor of cases. It is included, in addition, a summarized example which represents a case for SirBE and how the system helps to make a diagnosis. [Spanish] Se presenta el desarrollo de un sistema de diagnostico de generadores electricos que aplica tecnicas de inteligencia artificial, como es el razonamiento basado en casos, para apoyar la labor del ingeniero de diagnostico. Este sistema es parte de un sistema denominado CADIS, dedicado al diagnostico de generadores electricos fuera de linea y motivo de articulos anteriores. En esta ocasion se resaltan las caracteristicas del modulo de razonamiento basado en experiencias (SirBE), indicando como realizar un diagnostico utilizando casos similares y como editar la base de experiencia del sistema utilizando el editor interactivo de casos. Se incluye, ademas, un ejemplo resumido de lo que representa un caso para SiRBE y como el sistema ayuda a realizar un diagnostico.

  8. Prototipado rápido de sistemas de procesado de vídeo basados en el VFBC de Xilinx

    Directory of Open Access Journals (Sweden)

    Luis Manuel Garcés Socarrás

    2013-04-01

    Full Text Available El presente trabajo desarrolla módulos hardware para el prototipado rápido de sistemas de procesado de vídeo basados en el controlador de memoria para fotogramas de vídeo (VFBC de Xilinx. Esta implementación permite el almacenamiento de los fotogramas en memoria externa al dispositivo programable, así como su correcto manejo para el diseño de sistemas de procesado espacio-temporales utilizando el flujo de diseño basado en modelos de Xilinx System Generator. Los módulos hardware son los encargados de la configuración y control de las interfaces de escritura y lectura del VFBC, además de la manipulación de las señales de sincronismo de vídeo para la interconexión de periféricos de entrada y salida.El artículo incluye además la descripción de los módulos elaborados así como el análisis de los resultados del empleo de los mismos en el desarrollo de un demostrador de procesado temporal de vídeo utilizando un detector de movimiento simple sobre una placa Spartan-6 SP605 Evaluation Platform.

  9. Modelo de gestión para el suministro de materiales e insumos basado en la demanda

    Directory of Open Access Journals (Sweden)

    Isabel Cristina Arango Palacio

    2014-12-01

    Full Text Available Este artículo hace referencia a la gestión de la cadena de abastecimiento, la cual requiere la sincronización de actividades que incluyen el flujo de información e inventarios. Una gestión exitosa depende de la óptima integración y sincronización de las actividades e inventarios requeridos para satisfacer la demanda. A partir de la investigación realizada en una empresa de cosméticos de venta directa, se analizan las estrategias para mejorar la gestión del suministro enfocado a la demanda, de modo que se pueda responder al mercado y, al mismo tiempo, controlar los inventarios y evitar los agotados. En esta investigación se toman en consideración que el suministro basado en el consumo diario, con entregas frecuentes y lotes pequeños flexibiliza el abastecimiento con los cambios de la demanda, y el stock de seguridad en cada empresa de la cadena de abastecimiento se convierte en un amortiguador para proteger la variabilidad. La metodología comienza con la identificación del problema, las posibles causas y las relaciones con los efectos encontrados con el fin de obtener un modelo de gestión del abastecimiento basado en la demanda, para responder rápidamente a la sobredemanda sin generar agotados y, a la vez, reaccionar a la subdemanda sin exceso de inventario.

  10. Final Report on Utilization of TRU TRISO Fuel as Applied to HTR Systems Part I: Pebble Bed Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Brian Boer; Abderrafi M. Ougouag

    2011-03-01

    The Deep-Burn (DB) concept [ ] focuses on the destruction of transuranic nuclides from used light water reactor (LWR) fuel. These transuranic nuclides are incorporated into tri-isotopic (TRISO) coated fuel particles and used in gas-cooled reactors with the aim of a fractional fuel burnup of 60 to 70% in fissions per initial metal atom (FIMA). This high performance is expected through the use of multiple recirculation passes of the fuel in pebble form without any physical or chemical changes between passes. In particular, the concept does not call for reprocessing of the fuel between passes. In principle, the DB pebble bed concept employs the same reactor designs as the presently envisioned low-enriched uranium core designs, such as the 400 MWth Pebble Bed Modular Reactor (PBMR-400) [ ]. Although it has been shown in the previous Fiscal Year (FY) (2009) that a PuO2 fueled pebble bed reactor concept is viable, achieving a high fuel burnup while remaining within safety-imposed prescribed operational limits for fuel temperature, power peaking, and temperature reactivity feedback coefficients for the entire temperature range, is challenging. The presence of the isotopes 239Pu, 240Pu, and 241Pu that have resonances in the thermal energy range significantly modifies the neutron thermal energy spectrum as compared to a standard, UO2-fueled core. Therefore, the DB pebble bed core exhibits a relatively hard neutron energy spectrum. However, regions within the pebble bed that are near the graphite reflectors experience a locally softer spectrum. This can lead to power and temperature peaking in these regions. Furthermore, a shift of the thermal energy spectrum with increasing temperature can lead to increased absorption in the resonances of the fissile Pu isotopes. This can lead to a positive temperature reactivity coefficient for the graphite moderator under certain operating conditions. Regarding the coated particle performance, the FY 2009 investigations showed that no

  11. Thermionic Reactor Design Studies

    Energy Technology Data Exchange (ETDEWEB)

    Schock, Alfred

    1994-06-01

    During the 1960's and early 70's the author performed extensive design studies, analyses, and tests aimed at thermionic reactor concepts that differed significantly from those pursued by other investigators. Those studies, like most others under Atomic Energy Commission (AEC and DOE) and the National Aeronautics and Space Administration (NASA) sponsorship, were terminated in the early 1970's. Some of this work was previously published, but much of it was never made available in the open literature. U.S. interest in thermionic reactors resumed in the early 80's, and was greatly intensified by reports about Soviet ground and flight tests in the late 80's. This recent interest resulted in renewed U.S. thermionic reactor development programs, primarily under Department of Defense (DOD) and Department of Energy (DOE) sponsorship. Since most current investigators have not had an opportunity to study all of the author's previous work, a review of the highlights of that work may be of value to them. The present paper describes some of the author's conceptual designs and their rationale, and the special analytical techniques developed to analyze their performance. The basic designs, first published in 1963, are based on single-cell converters, either double-ended diodes extending over the full height of the reactor core or single-ended diodes extending over half the core height. In that respect they are similar to the thermionic fuel elements employed in the Topaz-2 reactor subsequently developed in the Soviet Union, copies of which were recently imported by the U.S. As in the Topaz-2 case, electrically heated steady-state performance tests of the converters are possible before fueling. Where the author's concepts differed from the later Topaz-2 design was in the relative location of the emitter and the collector. Placing the fueled emitter on the outside of the cylindrical diodes permits much higher axial conductances to reduce ohmic

  12. Nuevo métodos químico-analíticos basados en procesos de agregación molecular competitiva

    OpenAIRE

    Pedraza Vela, Ana María

    2011-01-01

    Los trabajos de investigación realizados en la Tesis Doctoral titulada"NUEVOS MÉTODOS QUÍMICO-ANALÍTICOS BASADOS EN PROCESOS DE AGREGACIÓN COMPETITIVA" han permitido consolidar la metodología de grado de enlace tensioactivo-colorante como una ventajosa alternativa para la determinación de diferentes tipos de analitos en una amplia variedad de matrices. Esta novedosa metodología se encuadra dentro de los métodos basados en la medida de parámetros de agregación y se fundamenta en la competencia...

  13. Aprendizaje de la agroecología basado en los fenómenos: un prerrequisito para la transdisciplinariedad y la acción responsable

    OpenAIRE

    Francis, Charles; Arvid Breland, Tor; Østergaard, Edvin; Lieblein, Geir; Morse, Suzanne

    2013-01-01

    El aprendizaje de la agroecología basado en los fenómenos proporciona una lógica y una plataforma para crear puentes entre la academia y la sociedad. El aprendizaje basado en experiencias reflexivas en granjas y en comunidades ha proporcionado el fundamento y el núcleo de un curso de agroecología en Noruega desde el año 2000 en la Universidad Noruega de las Ciencias de la Vida (NMBU). Los equipos de estudiantes trabajan con profesores de la Universidad y con las personas intere...

  14. New reactors for laboratory studies

    Energy Technology Data Exchange (ETDEWEB)

    Berty, J.M.

    1978-02-01

    Recent developments in design of laboratory and bench-scale reactors reflect mostly the developments in reaction engineering; that is the improved understanding of physical and chemical rate limiting processes, their interactions, and their effects on commercial-scale reactor performance. Whether a laboratory reactor is used to study the fundamentals of a commercial process or for pure scientific interest, it is important to know what physical or chemical process is limiting or influencing the rate and selectivity. To clarify this, a definition is required of the regime where physical influences exist, and study the intrinsic kinetics at conditions where physical processes do not affect the rate. Reactors are illustrated whose design was influenced by the above considerations. These reactors produce results which are independent of the reactors in which they were measured, and which can be scaled up with up-to-date reaction engineering techniques.

  15. Screening of Gas-Cooled Reactor Thermal-Hydraulic and Safety Analysis Tools and Experimental Database

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Won Jae; Kim, Min Hwan; Lee, Seung Wook (and others)

    2007-08-15

    This report is a final report of I-NERI Project, 'Screening of Gas-cooled Reactor Thermal Hydraulic and Safety Analysis Tools and Experimental Database 'jointly carried out by KAERI, ANL and INL. In this study, we developed the basic technologies required to develop and validate the VHTR TH/safety analysis tools and evaluated the TH/safety database information. The research tasks consist of; 1) code qualification methodology (INL), 2) high-level PIRTs for major nucleus set of events (KAERI, ANL, INL), 3) initial scaling and scoping analysis (ANL, KAERI, INL), 4) filtering of TH/safety tools (KAERI, INL), 5) evaluation of TH/safety database information (KAERI, INL, ANL) and 6) key scoping analysis (KAERI). The code qualification methodology identifies the role of PIRTs in the R and D process and the bottom-up and top-down code validation methods. Since the design of VHTR is still evolving, we generated the high-level PIRTs referencing 600MWth block-type GT-MHR and 400MWth pebble-type PBMR. Nucleus set of events that represents the VHTR safety and operational transients consists of the enveloping scenarios of HPCC (high pressure conduction cooling: loss of primary flow), LPCC/Air-Ingress (low pressure conduction cooling: loss of coolant), LC (load changes: power maneuvering), ATWS (anticipated transients without scram: reactivity insertion), WS (water ingress: water-interfacing system break) and HU (hydrogen-side upset: loss of heat sink). The initial scaling analysis defines dimensionless parameters that need to be reflected in mixed convection modeling and the initial scoping analysis provided the reference system transients used in the PIRTs generation. For the PIRTs phenomena, we evaluated the modeling capability of the candidate TH/safety tools and derived a model improvement need. By surveying and evaluating the TH/safety database information, a tools V and V matrix has been developed. Through the key scoping analysis using available database, the

  16. Spiral-shaped disinfection reactors

    KAUST Repository

    Ghaffour, Noreddine

    2015-08-20

    This disclosure includes disinfection reactors and processes for the disinfection of water. Some disinfection reactors include a body that defines an inlet, an outlet, and a spiral flow path between the inlet and the outlet, in which the body is configured to receive water and a disinfectant at the inlet such that the water is exposed to the disinfectant as the water flows through the spiral flow path. Also disclosed are processes for disinfecting water in such disinfection reactors.

  17. Turning points in reactor design

    Energy Technology Data Exchange (ETDEWEB)

    Beckjord, E.S.

    1995-09-01

    This article provides some historical aspects on nuclear reactor design, beginning with PWR development for Naval Propulsion and the first commercial application at Yankee Rowe. Five turning points in reactor design and some safety problems associated with them are reviewed: (1) stability of Dresden-1, (2) ECCS, (3) PRA, (4) TMI-2, and (5) advanced passive LWR designs. While the emphasis is on the thermal-hydraulic aspects, the discussion is also about reactor systems.

  18. Acceptability of reactors in space

    Energy Technology Data Exchange (ETDEWEB)

    Buden, D.

    1981-04-01

    Reactors are the key to our future expansion into space. However, there has been some confusion in the public as to whether they are a safe and acceptable technology for use in space. The answer to these questions is explored. The US position is that when reactors are the preferred technical choice, that they can be used safely. In fact, it dies not appear that reactors add measurably to the risk associated with the Space Transportation System.

  19. Hydrogen Production in Fusion Reactors

    OpenAIRE

    Sudo, S.; Tomita, Y.; Yamaguchi, S.; Iiyoshi, A.; Momota, H; Motojima, O.; Okamoto, M.; Ohnishi, M.; Onozuka, M; Uenosono, C.

    1993-01-01

    As one of methods of innovative energy production in fusion reactors without having a conventional turbine-type generator, an efficient use of radiation produced in a fusion reactor with utilizing semiconductor and supplying clean fuel in a form of hydrogen gas are studied. Taking the candidates of reactors such as a toroidal system and an open system for application of the new concepts, the expected efficiency and a concept of plant system are investigated.

  20. Fast reactor programme in India

    Indian Academy of Sciences (India)

    P Chellapandi; P R Vasudeva Rao; Prabhat Kumar

    2015-09-01

    Role of fast breeder reactor (FBR) in the Indian context has been discussed with appropriate justification. The FBR programme since 1985 till 2030 is highlighted focussing on the current status and future direction of fast breeder test reactor (FBTR), prototype fast breeder reactor (PFBR) and FBR-1 and 2. Design and technological challenges of PFBR and design and safety targets with means to achieve the same are the major highlights of this paper.

  1. Neutrino Oscillation Studies with Reactors

    CERN Document Server

    Vogel, Petr; Zhang, Chao

    2015-01-01

    Nuclear reactors are one of the most intense, pure, controllable, cost-effective, and well-understood sources of neutrinos. Reactors have played a major role in the study of neutrino oscillations, a phenomenon that indicates that neutrinos have mass and that neutrino flavors are quantum mechanical mixtures. Over the past several decades reactors were used in the discovery of neutrinos, were crucial in solving the solar neutrino puzzle, and allowed the determination of the smallest mixing angle $\\theta_{13}$. In the near future, reactors will help to determine the neutrino mass hierarchy and to solve the puzzling issue of sterile neutrinos.

  2. Accelerator based fusion reactor

    Science.gov (United States)

    Liu, Keh-Fei; Chao, Alexander Wu

    2017-08-01

    A feasibility study of fusion reactors based on accelerators is carried out. We consider a novel scheme where a beam from the accelerator hits the target plasma on the resonance of the fusion reaction and establish characteristic criteria for a workable reactor. We consider the reactions d+t\\to n+α,d+{{}3}{{H}\\text{e}}\\to p+α , and p+{{}11}B\\to 3α in this study. The critical temperature of the plasma is determined from overcoming the stopping power of the beam with the fusion energy gain. The needed plasma lifetime is determined from the width of the resonance, the beam velocity and the plasma density. We estimate the critical beam flux by balancing the energy of fusion production against the plasma thermo-energy and the loss due to stopping power for the case of an inert plasma. The product of critical flux and plasma lifetime is independent of plasma density and has a weak dependence on temperature. Even though the critical temperatures for these reactions are lower than those for the thermonuclear reactors, the critical flux is in the range of {{10}22}-{{10}24}~\\text{c}{{\\text{m}}-2}~{{\\text{s}}-1} for the plasma density {ρt}={{10}15}~\\text{c}{{\\text{m}}-3} in the case of an inert plasma. Several approaches to control the growth of the two-stream instability are discussed. We have also considered several scenarios for practical implementation which will require further studies. Finally, we consider the case where the injected beam at the resonance energy maintains the plasma temperature and prolongs its lifetime to reach a steady state. The equations for power balance and particle number conservation are given for this case.

  3. Emerging Energy Requirements for Future C4ISR

    Science.gov (United States)

    2002-09-01

    fulfill the role once envisioned for the military energy depot. One proposed design is the pebble bed modular reactor ( PBMR ) under development by...designs. The PBMR and GT-MHR, coupled with a direct-cycle gas turbine generator, would have a thermal efficiency of about 42-45 percent and would produce

  4. Biparticle fluidized bed reactor

    Science.gov (United States)

    Scott, C.D.

    1993-12-14

    A fluidized bed reactor system which utilizes a fluid phase, a retained fluidized primary particulate phase, and a migratory second particulate phase is described. The primary particulate phase is a particle such as a gel bead containing an immobilized biocatalyst. The secondary particulate phase, continuously introduced and removed in either cocurrent or countercurrent mode, acts in a secondary role such as a sorbent to continuously remove a product or by-product constituent from the fluid phase. Introduction and removal of the sorbent phase is accomplished through the use of feed screw mechanisms and multivane slurry valves. 3 figures.

  5. FAST NEUTRONIC REACTOR

    Science.gov (United States)

    Snell, A.H.

    1957-12-01

    This patent relates to a reactor and process for carrying out a controlled fast neutron chain reaction. A cubical reactive mass, weighing at least 920 metric tons, of uranium metal containing predominantly U/sup 238/ and having a U/sup 235/ content of at least 7.63% is assembled and the maximum neutron reproduction ratio is limited to not substantially over 1.01 by insertion and removal of a varying amount of boron, the reactive mass being substantially freed of moderator.

  6. Licensed reactor nuclear safety criteria applicable to DOE reactors

    Energy Technology Data Exchange (ETDEWEB)

    1991-04-01

    The Department of Energy (DOE) Order DOE 5480.6, Safety of Department of Energy-Owned Nuclear Reactors, establishes reactor safety requirements to assure that reactors are sited, designed, constructed, modified, operated, maintained, and decommissioned in a manner that adequately protects health and safety and is in accordance with uniform standards, guides, and codes which are consistent with those applied to comparable licensed reactors. This document identifies nuclear safety criteria applied to NRC (Nuclear Regulatory Commission) licensed reactors. The titles of the chapters and sections of USNRC Regulatory Guide 1.70, Standard Format and Content of Safety Analysis Reports for Nuclear Power Plants, Rev. 3, are used as the format for compiling the NRC criteria applied to the various areas of nuclear safety addressed in a safety analysis report for a nuclear reactor. In each section the criteria are compiled in four groups: (1) Code of Federal Regulations, (2) US NRC Regulatory Guides, SRP Branch Technical Positions and Appendices, (3) Codes and Standards, and (4) Supplemental Information. The degree of application of these criteria to a DOE-owned reactor, consistent with their application to comparable licensed reactors, must be determined by the DOE and DOE contractor.

  7. Fast Reactor Fuel Type and Reactor Safety Performance

    Energy Technology Data Exchange (ETDEWEB)

    R. Wigeland; J. Cahalan

    2009-09-01

    Fast Reactor Fuel Type and Reactor Safety Performance R. Wigeland , Idaho National Laboratory J. Cahalan, Argonne National Laboratory The sodium-cooled fast neutron reactor is currently being evaluated for the efficient transmutation of the highly-hazardous, long-lived, transuranic elements that are present in spent nuclear fuel. One of the fundamental choices that will be made is the selection of the fuel type for the fast reactor, whether oxide, metal, carbide, nitride, etc. It is likely that a decision on the fuel type will need to be made before many of the related technologies and facilities can be selected, from fuel fabrication to spent fuel reprocessing. A decision on fuel type should consider all impacts on the fast reactor system, including safety. Past work has demonstrated that the choice of fuel type may have a significant impact on the severity of consequences arising from accidents, especially for severe accidents of low probability. In this paper, the response of sodium-cooled fast reactors is discussed for both oxide and metal fuel types, highlighting the similarities and differences in reactor response and accident consequences. Any fast reactor facility must be designed to be able to successfully prevent, mitigate, or accommodate all consequences of potential events, including accidents. This is typically accomplished by using multiple barriers to the release of radiation, including the cladding on the fuel, the intact primary cooling system, and most visibly the reactor containment building. More recently, this has also included the use of ‘inherent safety’ concepts to reduce or eliminate the potential for serious damage in some cases. Past experience with oxide and metal fuel has demonstrated that both fuel types are suitable for use as fuel in a sodium-cooled fast reactor. However, safety analyses for these two fuel types have also shown that there can be substantial differences in accident consequences due to the neutronic and

  8. Reactor Physics Analysis Models for a CANDU Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Hang Bok

    2007-10-15

    Canada deuterium uranium (CANDU) reactor physics analysis is typically performed in three steps. At first, macroscopic cross-sections of the reference lattice is produced by modeling the reference fuel channel. Secondly macroscopic cross-sections of reactivity devices in the reactor are generated. The macroscopic cross-sections of a reactivity device are calculated as incremental cross-sections by subtracting macroscopic cross-sections of a three-dimensional lattice without reactivity device from those of a three-dimensional lattice with a reactivity device. Using the macroscopic cross-sections of the reference lattice and incremental cross-sections of the reactivity devices, reactor physics calculations are performed. This report summarizes input data of typical CANDU reactor physics codes, which can be utilized for the future CANDU reactor physics analysis.

  9. Reactor Physics Analysis Models for a CANDU Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Hang Bok

    2007-10-15

    Canada deuterium uranium (CANDU) reactor physics analysis is typically performed in three steps. At first, macroscopic cross-sections of the reference lattice is produced by modeling the reference fuel channel. Secondly macroscopic cross-sections of reactivity devices in the reactor are generated. The macroscopic cross-sections of a reactivity device are calculated as incremental cross-sections by subtracting macroscopic cross-sections of a three-dimensional lattice without reactivity device from those of a three-dimensional lattice with a reactivity device. Using the macroscopic cross-sections of the reference lattice and incremental cross-sections of the reactivity devices, reactor physics calculations are performed. This report summarizes input data of typical CANDU reactor physics codes, which can be utilized for the future CANDU reactor physics analysis.

  10. Diseño de un Banco del Tiempo Escolar basado en la metodología Peer Tutoring (Tutoría entre iguales)

    OpenAIRE

    Rodríguez Suárez, Vanesa

    2015-01-01

    Reflexión sobre las prácticas, programación didáctica e innovación consistente en el diseño de un banco del tiempo llevado al ámbito escolar y basado en la metodología Peer Tutoring (Tutoría entre iguales).

  11. Enlace Oferta-Demanda de Consumidor a Consumidor en Comercio Electrónico basado en Agentes Inteligentes-Única

    OpenAIRE

    Silva Palacios, Beatriz Eugenia

    1999-01-01

    Notas del catalogo: Dado el desarrollo del Comercio Electrónico basado en la extensa cobertura mundial de Internet, los consumidores tienen la oportunidad de contactar a muchos vendedores buscando cubrir sus necesidades al menor costo y mayor satisfacci.... Bibliografía: h. 107-109. Desc. física: x, 110 h. : il. ; 28 cm

  12. Presentación del artículo “Mirando hacia el futuro: Ecosistemas tecnológicos de aprendizaje basados en servicios”

    OpenAIRE

    Francisco José GARCÍA-PEÑALVO; Fidalgo-Blanco, Ángel; Llorens-Largo, Faraón; Hernández García, Ángel; Sein-Echaluce, María Luisa; Santiago IGLESIAS-PRADAS; Conde González, Miguel Ángel

    2015-01-01

    [ES]Esta es la presentación del artículo “Mirando hacia el futuro: Ecosistemas tecnológicos de aprendizaje basados en servicios” realizada en el CINAIC 2015 celebrado en Madrid (España) los días 14-16 de octubre de 2015.

  13. Apero para la roturación y surcado basado en el principio de la herramienta brocha mecánica

    National Research Council Canada - National Science Library

    Roberto Amado Albóniga Gil

    2015-01-01

    La presente investigación fundamenta teórica y experimentalmente los parámetros de diseño de un apero basados en los principios de trabajo de la herramienta denominada brocha mecánica. La experimentación se realizó...

  14. Chemical-vapor-deposition reactor

    Science.gov (United States)

    Chern, S.

    1979-01-01

    Reactor utilizes multiple stacked trays compactly arranged in paths of horizontally channeled reactant gas streams. Design allows faster and more efficient deposits of film on substrates, and reduces gas and energy consumption. Lack of dead spots that trap reactive gases reduces reactor purge time.

  15. Thermochemical reactor systems and methods

    Energy Technology Data Exchange (ETDEWEB)

    Lipinski, Wojciech; Davidson, Jane Holloway; Chase, Thomas Richard

    2016-11-29

    Thermochemical reactor systems that may be used to produce a fuel, and methods of using the thermochemical reactor systems, utilizing a reactive cylindrical element, an optional energy transfer cylindrical element, an inlet gas management system, and an outlet gas management system.

  16. Test reactor risk assessment methodology

    Energy Technology Data Exchange (ETDEWEB)

    Jennings, R.H.; Rawlins, J.K.; Stewart, M.E.

    1976-04-01

    A methodology has been developed for the identification of accident initiating events and the fault modeling of systems, including common mode identification, as these methods are applied in overall test reactor risk assessment. The methods are exemplified by a determination of risks to a loss of primary coolant flow in the Engineering Test Reactor.

  17. Studies on a membrane reactor

    Energy Technology Data Exchange (ETDEWEB)

    Mohan, K.; Govind, R.

    1988-10-01

    Simulation is used to evaluate the performance of a catalytic reactor with permeable wall (membrane reactor) in shifting the equilibrium of three reversible reactions (cyclohexane dehydrogenation, hydrogen iodide decomposition, and propylene disproportionation). It is found that the preferred choice of cocurrernt or countercurrent operation is dependent on the physical properties and operating conditions. Methods of enhancing conversion are suggested and temperature effects are discussed.

  18. Thermochemical reactor systems and methods

    Science.gov (United States)

    Lipinski, Wojciech; Davidson, Jane Holloway; Chase, Thomas Richard

    2016-11-29

    Thermochemical reactor systems that may be used to produce a fuel, and methods of using the thermochemical reactor systems, utilizing a reactive cylindrical element, an optional energy transfer cylindrical element, an inlet gas management system, and an outlet gas management system.

  19. Brookhaven leak reactor to close

    CERN Multimedia

    MacIlwain, C

    1999-01-01

    The DOE has announced that the High Flux Beam Reactor at Brookhaven is to close for good. Though the news was not unexpected researchers were angry the decision had been taken before the review to assess the impact of reopening the reactor had been concluded (1 page).

  20. Modelos borrosos de optimización para la selección de carteras basados en intervalos de medias

    Directory of Open Access Journals (Sweden)

    José D. Bermúdez

    2007-01-01

    Full Text Available Se presentan dos modelos borrosos de selección de carteras basados en la utilización de intervalos de medias para el cálculo del rendimiento y del riesgo de la cartera. Los rendimientos de los activos financieros se aproximan mediante números borrosos de tipo LR con funciones de referencia de la misma forma y se analiza la relación entre dos definiciones diferentes de intervalos de medias. Para números borrosos trapezoidales se realiza la comparación de los modelos propuestos, que permiten seleccionar una cartera mediante la resolución de un problema de optimización lineal

  1. Proceso de Identificación de Comportamiento de Comunidades Educativas Basado en Resultados Académicos

    Directory of Open Access Journals (Sweden)

    Pablo Cigliuti

    2014-12-01

    Full Text Available Los procesos de explotación de información se incorporan al ámbito educativo para ayudar a entender y mejorar tanto la enseñanza de los docentes como el aprendizaje de los alumnos. Entre estas cuestiones se destaca el análisis del comportamiento de comunidades educativas de forma tal de proveer al docente herramientas que ayuden a mejorar la enseñanza/aprendizaje. En este contexto, el presente trabajo tiene como objetivo proponer, estudiar y validar un proceso de explotación de información que permita identificar el comportamiento de comunidades educativas basado en resultados académicos.

  2. Un enfoque basado en la resolución de problemas para la enseñanza de la POO

    OpenAIRE

    Rueda, Sonia Vivian; Señas, Perla

    2008-01-01

    La enseñanza de la programación en las materias iniciales de las carreras de Ciencias de la Computación ha sido siempre un desafío importante. En los nuevos planes de estudio de Licenciatura en Ciencias de la Computación e Ingeniería en Sistemas de Computación hemos adoptado desde el primer año el paradigma de programación orientada a objetos con un enfoque basado en la resolución de problemas. El objetivo de la asignatura Introducción a la Programación Orientada a Objetos es que los alumnos ...

  3. Efecto del ejercicio físico basado en el juego en la leucemia linfocítica aguda

    OpenAIRE

    González García, Laura Ximena; Escobar Zabala, Paola Andrea

    2012-01-01

    Objetivo: Establecer el efecto de un programa de ejercicio físico (EF) basado en el juego sobre el Síndrome de Desacondicionamiento Físico (SDF) de niños con Leucemia Linfocítica Aguda (LLA) entre 5-12 años. Materiales y Métodos: Se realizó un estudio cuasi-experimental con la participación de siete niños tratados por LLA en el Instituto Nacional de Cancerología (INC). Se hizo una evaluación inicial de los determinantes de la condición física (capacidad aeróbica, fuerza muscular, flexibil...

  4. Metallic fuels for advanced reactors

    Science.gov (United States)

    Carmack, W. J.; Porter, D. L.; Chang, Y. I.; Hayes, S. L.; Meyer, M. K.; Burkes, D. E.; Lee, C. B.; Mizuno, T.; Delage, F.; Somers, J.

    2009-07-01

    In the framework of the Generation IV Sodium Fast Reactor Program, the Advanced Fuel Project has conducted an evaluation of the available fuel systems supporting future sodium cooled fast reactors. This paper presents an evaluation of metallic alloy fuels. Early US fast reactor developers originally favored metal alloy fuel due to its high fissile density and compatibility with sodium. The goal of fast reactor fuel development programs is to develop and qualify a nuclear fuel system that performs all of the functions of a conventional fast spectrum nuclear fuel while destroying recycled actinides. This will provide a mechanism for closure of the nuclear fuel cycle. Metal fuels are candidates for this application, based on documented performance of metallic fast reactor fuels and the early results of tests currently being conducted in US and international transmutation fuel development programs.

  5. A model of reactor kinetics

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, A.S.; Thompson, B.R.

    1988-09-01

    The analytical model of nuclear reactor transients, incorporating both mechanical and nuclear effects, simulates reactor kinetics. Linear analysis shows the stability borderline for small power perturbations. In a stable system, initial power disturbances die out with time. With an unstable combination of nuclear and mechanical characteristics, initial disturbances persist and may increase with time. With large instability, oscillations of great magnitude occur. Stability requirements set limits on the power density at which particular reactors can operate. The limiting power density depends largely on the product of two terms: the fraction of delayed neutrons and the frictional damping of vibratory motion in reactor core components. As the fraction of delayed neutrons is essentially fixed, mechanical damping largely determines the maximum power density. A computer program, based on the analytical model, calculates and plots reactor power as a nonlinear function of time in response to assigned values of mechanical and nuclear characteristics.

  6. Engineering reactors for catalytic reactions

    Indian Academy of Sciences (India)

    Vivek V Ranade

    2014-03-01

    Catalytic reactions are ubiquitous in chemical and allied industries. A homogeneous or heterogeneous catalyst which provides an alternative route of reaction with lower activation energy and better control on selectivity can make substantial impact on process viability and economics. Extensive studies have been conducted to establish sound basis for design and engineering of reactors for practising such catalytic reactions and for realizing improvements in reactor performance. In this article, application of recent (and not so recent) developments in engineering reactors for catalytic reactions is discussed. Some examples where performance enhancement was realized by catalyst design, appropriate choice of reactor, better injection and dispersion strategies and recent advances in process intensification/ multifunctional reactors are discussed to illustrate the approach.

  7. Unsteady processes in catalytic reactors

    Energy Technology Data Exchange (ETDEWEB)

    Matros, Yu.Sh.

    1985-01-01

    In recent years a realization has occurred that reaction and reactor dynamics must be considered when designing and operating catalytic reactors. In this book, the author has focussed on both the processes occurring on individual porous-catalyst particles as well as the phenomena displayed by collections of these particles in fixed-bed reactors. The major topics discussed include the effects of unsteady-state heat and mass transfer, the influence of inhomogeneities and stagnant regions in fixed beds, and reactor operation during forced cycling of operating conditions. Despite the title of the book, attention is also paid to the determination of the number and stability of fixed-bed steady states, with the aim of describing the possibility of controlling reactors at unstable steady states. However, this development is somewhat dated, given the recent literature on multiplicity phenomena and process control.

  8. Antineutrino Monitoring of Thorium Reactors

    CERN Document Server

    Akindele, Oluwatomi A; Norman, Eric B

    2015-01-01

    Various groups have demonstrated that antineutrino monitoring can be successful in assessing the plutonium content in water-cooled nuclear reactors for nonproliferation applications. New reactor designs and concepts incorporate nontraditional fuels types and chemistry. Understanding how these properties affect the antineutrino emission from a reactor can extend the applicability of antineutrino monitoring.Thorium molten salt reactors (MSR) breed U-233, that if diverted constitute an IAEA direct use material. The antineutrino spectrum from the fission of U-233 has been determined, the feasibility of detecting the diversion of a significant quantity, 8 kg of U-233, within the IAEA timeliness goal of 30 days has been evaluated. The antineutrino emission from a thorium reactor operating under normal conditions is compared to a diversion scenario at a 25 meter standoff by evaluating the daily antineutrino count rate and the energy spectrum of the detected antineutrinos. It was found that the diversion of a signifi...

  9. ENSEÑAR BIOÉTICA A ESTUDIANTES DE MEDICINA MEDIANTE EL APRENDIZAJE BASADO EN PROBLEMAS (ABP

    Directory of Open Access Journals (Sweden)

    JOAQUIM BOSCH-BARRERA

    2015-01-01

    Full Text Available Se describe la implantación de la asignatura de Bioética en una Facultad de Medicina con el objetivo de dotar a los 73 alumnos de quinto curso de competencias para manejar conflictos éticos en su práctica profesional. El método docente utilizado principalmente fue el aprendizaje basado en problemas. Se describen las competencias y objetivos docentes marcados. El diseño de la asignatura consistió en un seminario teórico (2 horas, un taller práctico (2 horas, cuatro casos de aprendizaje basado en problemas (ABP (24 horas en total y un taller de dramatizaciones (Role Playing (2 horas. El seminario se orientó a la adquisición de conocimientos teóricos básicos sobre bioética. Los casos ABP facilitaron la valoración crítica, la obtención de conocimiento, y su aplicación. Los Role Playing se encaminaron a la demostración práctica de las competencias adquiridas en un entorno simulado. Se realizó una evaluación continuada de los alumnos durante su trabajo en los casos ABP (40% de la nota, y una evaluación final de la asignatura mediante un examen (60% de la nota. Los alumnos evaluaron la asignatura y al profesorado de forma anónima, siendo los resultados positivos (8,5/10.

  10. Modeling of packed bed membrane reactors: impact of oxygen distribution on conversion and selectivity in partial oxidation systems

    NARCIS (Netherlands)

    Kürten, Ulrich

    2003-01-01

    In this thesis the focus is on the effect of the oxygen distribution on the performance of the PBMR in terms of conversion and selectivities. A detailed description of the oxygen transport through the membrane is not considered in this work. Here, the membrane is considered as an ideal distributor w

  11. Licensed reactor nuclear safety criteria applicable to DOE reactors

    Energy Technology Data Exchange (ETDEWEB)

    1993-11-01

    This document is a compilation and source list of nuclear safety criteria that the Nuclear Regulatory Commission (NRC) applies to licensed reactors; it can be used by DOE and DOE contractors to identify NRC criteria to be evaluated for application to the DOE reactors under their cognizance. The criteria listed are those that are applied to the areas of nuclear safety addressed in the safety analysis report of a licensed reactor. They are derived from federal regulations, USNRC regulatory guides, Standard Review Plan (SRP) branch technical positions and appendices, and industry codes and standards.

  12. University Reactor Conversion Lessons Learned Workshop for Purdue University Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Eric C. Woolstenhulme; Dana M. Hewit

    2008-09-01

    The Department of Energy’s Idaho National Laboratory, under its programmatic responsibility for managing the University Research Reactor Conversions, has completed the conversion of the reactor at Purdue University Reactor. With this work completed and in anticipation of other impending conversion projects, the INL convened and engaged the project participants in a structured discussion to capture the lessons learned. The lessons learned process has allowed us to capture gaps, opportunities, and good practices, drawing from the project team’s experiences. These lessons will be used to raise the standard of excellence, effectiveness, and efficiency in all future conversion projects.

  13. Neutronic Reactor Shield

    Science.gov (United States)

    Fermi, Enrico; Zinn, Walter H.

    The argument of the present Patent is a radiation shield suitable for protection of personnel from both gamma rays and neutrons. Such a shield from dangerous radiations is achieved to the best by the combined action of a neutron slowing material (a moderator) and a neutron absorbing material. Hydrogen is particularly effective for this shield since it is a good absorber of slow neutrons and a good moderator of fast neutrons. The neutrons slowed down by hydrogen may, then, be absorbed by other materials such as boron, cadmium, gadolinium, samarium or steel. Steel is particularly convenient for the purpose, given its effectiveness in absorbing also the gamma rays from the reactor (both primary gamma rays and secondary ones produced by the moderation of neutrons). In particular, in the present Patent a shield is described, made of alternate layers of steel and Masonite (an hydrolized ligno-cellulose material). The object of the present Patent is not discussed in any other published paper.

  14. Neutrino Experiments at Reactors

    Science.gov (United States)

    Reines, F.; Gurr, H. S.; Jenkins, T. L.; Munsee, J. H.

    1968-09-09

    A description is given of the electron-antineutrino program using a large fission reactor. A search has been made for a neutral weak interaction via the reaction (electron antineutrino + d .> p + n + electron antineutrino), the reaction (electron antineutrino + d .> n + n + e{sup +}) has now been detected, and an effort is underway to observe the elastic scattering reaction (electron antineutrino + e{sup -} .> electron antineutrino + e{sup -}) as well as to measure more precisely the reaction (electron antineutrino + p .> n + e{sup+}). The upper limit on the elastic scattering reaction which we have obtained with our large composite NaI, plastic, liquid scintillation detector is now about 50 times the predicted value.

  15. Reactor service life extension program

    Energy Technology Data Exchange (ETDEWEB)

    Caskey, G.R.; Sindelar, R.L.; Ondrejcin, R.S.; Baumann, E.W.

    1990-12-31

    A review of the Savannah River Site production reactor systems was initiated in 1980 and led to implementation of the Reactor Materials Program in 1984 to assess reactor safety and reactor service life. The program evaluated performance of the reactor tanks, primary coolant piping, and thermal shields, components of welded construction that were fabricated from Type 304 stainless steel. The structural integrity analysis of the primary coolant system has shown that the pressure boundary is not susceptible to gross rupture, including a double ended guillotine break or equivalent large area bank. Residual service life is potentially limited by two material degradation modes, irradiation damage and intergranular stress corrosion cracking. Analysis of the structural integrity of the tanks and piping has shown that continued safe operation of the reactors for several additional decades is not limited by the material performance of the primary coolant system. Although irradiation damage has not degraded material behavior to an unacceptable level, past experience has revealed serious difficulties with repair welding on irradiated stainless steel. Stress corrosion can be mitigated by newly identified limits on impurity concentrations in the coolant water and by stress mitigation of weld residual stresses. Work continues in several areas: the effects of helium on mechanical behavior of irradiated stainless steel; improved weld methods for piping and the reactor tanks; and a surveillance program to track irradiation effects on the tank walls.

  16. Reactor service life extension program

    Energy Technology Data Exchange (ETDEWEB)

    Caskey, G.R.; Sindelar, R.L.; Ondrejcin, R.S.; Baumann, E.W.

    1990-01-01

    A review of the Savannah River Site production reactor systems was initiated in 1980 and led to implementation of the Reactor Materials Program in 1984 to assess reactor safety and reactor service life. The program evaluated performance of the reactor tanks, primary coolant piping, and thermal shields, components of welded construction that were fabricated from Type 304 stainless steel. The structural integrity analysis of the primary coolant system has shown that the pressure boundary is not susceptible to gross rupture, including a double ended guillotine break or equivalent large area bank. Residual service life is potentially limited by two material degradation modes, irradiation damage and intergranular stress corrosion cracking. Analysis of the structural integrity of the tanks and piping has shown that continued safe operation of the reactors for several additional decades is not limited by the material performance of the primary coolant system. Although irradiation damage has not degraded material behavior to an unacceptable level, past experience has revealed serious difficulties with repair welding on irradiated stainless steel. Stress corrosion can be mitigated by newly identified limits on impurity concentrations in the coolant water and by stress mitigation of weld residual stresses. Work continues in several areas: the effects of helium on mechanical behavior of irradiated stainless steel; improved weld methods for piping and the reactor tanks; and a surveillance program to track irradiation effects on the tank walls.

  17. Assessment of torsatrons as reactors

    Energy Technology Data Exchange (ETDEWEB)

    Lyon, J.F. (Oak Ridge National Lab., TN (United States)); Painter, S.L. (Australian National Univ., Canberra, ACT (Australia))

    1992-12-01

    Stellarators have significant operational advantages over tokamaks as ignited steady-state reactors because stellarators have no dangerous disruptions and no need for continuous current drive or power recirculated to the plasma, both easing the first wall, blanket, and shield design; less severe constraints on the plasma parameters and profiles; and better access for maintenance. This study shows that a reactor based on the torsatron configuration (a stellarator variant) could also have up to double the mass utilization efficiency (MUE) and a significantly lower cost of electricity (COE) than a conventional tokamak reactor (ARIES-I) for a range of assumptions. Torsatron reactors can have much smaller coil systems than tokamak reactors because the coils are closer to the plasma and they have a smaller cross section (higher average current density because of the lower magnetic field). The reactor optimization approach and the costing and component models are those used in the current stage of the ARIES-I tokamak reactor study. Typical reactor parameters for a 1-GW(e) Compact Torsatron reactor example are major radius R[sub 0] = 6.6-8.8 m, on-axis magnetic field B[sup 0] = 4.8-7.5 T, B[sub max] (on coils) = 16 T, MUE 140-210 kW(e)/tonne, and COE (in constant 1990 dollars) = 67-79 mill/kW(e)h. The results are relatively sensitive to assumptions on the level of confinement improvement and the blanket thickness under the inboard half of the helical windings but relatively insensitive to other assumptions.

  18. Safety of VVER-440 reactors

    CERN Document Server

    Slugen, Vladimir

    2011-01-01

    Safety of VVER-440 Reactors endeavours to promote an increase in the safety of VVER-440 nuclear reactors via the improvement of fission products limitation systems and the implementation of special non-destructive spectroscopic methods for materials testing. All theoretical and experimental studies performed the by author over the last 25 years have been undertaken with the aim of improving VVER-440 defence in depth, which is one of the most important principle for ensuring safety in nuclear power plants. Safety of VVER-440 Reactors is focused on the barrier system through which the safety pri

  19. Random processes in nuclear reactors

    CERN Document Server

    Williams, M M R

    1974-01-01

    Random Processes in Nuclear Reactors describes the problems that a nuclear engineer may meet which involve random fluctuations and sets out in detail how they may be interpreted in terms of various models of the reactor system. Chapters set out to discuss topics on the origins of random processes and sources; the general technique to zero-power problems and bring out the basic effect of fission, and fluctuations in the lifetime of neutrons, on the measured response; the interpretation of power reactor noise; and associated problems connected with mechanical, hydraulic and thermal noise sources

  20. Reactor neutrons in nuclear astrophysics

    Science.gov (United States)

    Reifarth, René; Glorius, Jan; Göbel, Kathrin; Heftrich, Tanja; Jentschel, Michael; Jurado, Beatriz; Käppeler, Franz; Köster, Ulli; Langer, Christoph; Litvinov, Yuri A.; Weigand, Mario

    2017-09-01

    The huge neutron fluxes offer the possibility to use research reactors to produce isotopes of interest, which can be investigated afterwards. An example is the half-lives of long-lived isotopes like 129I. A direct usage of reactor neutrons in the astrophysical energy regime is only possible, if the corresponding ions are not at rest in the laboratory frame. The combination of an ion storage ring with a reactor and a neutron guide could open the path to direct measurements of neutron-induced cross sections on short-lived radioactive isotopes in the astrophysically interesting energy regime.

  1. Concept for LEU Burst Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Klein, Steven Karl [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Kimpland, Robert Herbert [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-03-07

    Design and performance of a proposed LEU burst reactor are sketched. Salient conclusions reached are the following: size would be ~1,500 kg or greater, depending on the size of the central cavity; internal stresses during burst require split rings for relief; the reactor would likely require multiple control and safety rods for fine control; the energy spectrum would be comparable to that of HEU machines; and burst yields and steady-state power levels will be significantly greater in an LEU reactor.

  2. Nuclear reactor downcomer flow deflector

    Energy Technology Data Exchange (ETDEWEB)

    Gilmore, Charles B. (Greensburg, PA); Altman, David A. (Pittsburgh, PA); Singleton, Norman R. (Murrysville, PA)

    2011-02-15

    A nuclear reactor having a coolant flow deflector secured to a reactor core barrel in line with a coolant inlet nozzle. The flow deflector redirects incoming coolant down an annulus between the core barrel and the reactor vessel. The deflector has a main body with a front side facing the fluid inlet nozzle and a rear side facing the core barrel. The rear side of the main body has at least one protrusion secured to the core barrel so that a gap exists between the rear side of the main body adjacent the protrusion and the core barrel. Preferably, the protrusion is a relief that circumscribes the rear side of the main body.

  3. Fuel Fabrication and Nuclear Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Karpius, Peter Joseph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-02-02

    The uranium from the enrichment plant is still in the form of UF6. UF6 is not suitable for use in a reactor due to its highly corrosive chemistry as well as its phase diagram. UF6 is converted into UO2 fuel pellets, which are in turn placed in fuel rods and assemblies. Reactor designs are variable in moderators, coolants, fuel, performance etc.The dream of energy ‘too-cheap to meter’ is no more, and now the nuclear power industry is pushing ahead with advanced reactor designs.

  4. Measurement channel of neutron flow based on software; Canal de medicion de flujo neutronico basado en software

    Energy Technology Data Exchange (ETDEWEB)

    Rivero G, T.; Benitez R, J. S. [ININ, 52750 La Marquesa, Estado de Mexico (Mexico)]. e-mail: trg@nuclear.inin.mx

    2008-07-01

    The measurement of the thermal power in nuclear reactors is based mainly on the measurement of the neutron flow. The presence of these in the reactor core is associated to neutrons released by the fission reaction of the uranium-235. Once moderate, these neutrons are precursors of new fissions. This process it is known like chain reaction. Thus, the power to which works a nuclear reactor, he is proportional to the number of produced fissions and as these depend on released neutrons, also the power is proportional to the number of present neutrons. The measurement of the thermal power in a reactor is realized with called instruments nuclear channels. To low power (level source), these channels measure the individual counts of detected neutrons, whereas to a medium and high power, they measure the electrical current or fluctuation of the same one that generate the fission neutrons in ionization chambers especially designed to detect neutrons. For the case of TRIGA reactors, the measurement channels of neutron flow use discreet digital electronic technology makes some decades already. Recently new technological tools have arisen that allow developing new versions of nuclear channels of simple form and compacts. The present work consists of the development of a nuclear channel for TRIGA reactors based on the use of the correlated signal of a fission chamber for ample interval. This new measurement channel uses a data acquisition card of high speed and the data processing by software that to the being installed in a computer is created a virtual instrument, with what spreads in real time, in graphic and understandable form for the operator, the power indication to which it operates the nuclear reactor. This system when being based on software, offers a major versatility to realize changes in the signal processing and power monitoring algorithms. The experimental tests of neutronic power measurement show a reliable performance through seven decades of power, with a

  5. Breeder Reactors, Understanding the Atom Series.

    Science.gov (United States)

    Mitchell, Walter, III; Turner, Stanley E.

    The theory of breeder reactors in relationship to a discussion of fission is presented. Different kinds of reactors are characterized by the cooling fluids used, such as liquid metal, gas, and molten salt. The historical development of breeder reactors over the past twenty-five years includes specific examples of reactors. The location and a brief…

  6. Evolution of the tandem mirror reactor concept

    Energy Technology Data Exchange (ETDEWEB)

    Carlson, G.A.; Logan, B.G.

    1982-03-09

    We discuss the evolution of the tandem mirror reactor concept from the original conceptual reactor design (1977) through the first application of the thermal barrier concept to a reactor design (1979) to the beginning of the Mirror Advanced Reactor Study (1982).

  7. FASTER Test Reactor Preconceptual Design Report

    Energy Technology Data Exchange (ETDEWEB)

    Grandy, C. [Argonne National Lab. (ANL), Argonne, IL (United States); Belch, H. [Argonne National Lab. (ANL), Argonne, IL (United States); Brunett, A. J. [Argonne National Lab. (ANL), Argonne, IL (United States); Heidet, F. [Argonne National Lab. (ANL), Argonne, IL (United States); Hill, R. [Argonne National Lab. (ANL), Argonne, IL (United States); Hoffman, E. [Argonne National Lab. (ANL), Argonne, IL (United States); Jin, E. [Argonne National Lab. (ANL), Argonne, IL (United States); Mohamed, W. [Argonne National Lab. (ANL), Argonne, IL (United States); Moisseytsev, A. [Argonne National Lab. (ANL), Argonne, IL (United States); Passerini, S. [Argonne National Lab. (ANL), Argonne, IL (United States); Sienicki, J. [Argonne National Lab. (ANL), Argonne, IL (United States); Sumner, T. [Argonne National Lab. (ANL), Argonne, IL (United States); Vilim, R. [Argonne National Lab. (ANL), Argonne, IL (United States); Hayes, S. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-03-31

    The FASTER test reactor plant is a sodium-cooled fast spectrum test reactor that provides high levels of fast and thermal neutron flux for scientific research and development. The 120MWe FASTER reactor plant has a superheated steam power conversion system which provides electrical power to a local grid allowing for recovery of operating costs for the reactor plant.

  8. FASTER test reactor preconceptual design report summary

    Energy Technology Data Exchange (ETDEWEB)

    Grandy, C. [Argonne National Lab. (ANL), Argonne, IL (United States); Belch, H. [Argonne National Lab. (ANL), Argonne, IL (United States); Brunett, A. [Argonne National Lab. (ANL), Argonne, IL (United States); Heidet, F. [Argonne National Lab. (ANL), Argonne, IL (United States); Hill, R. [Argonne National Lab. (ANL), Argonne, IL (United States); Hoffman, E. [Argonne National Lab. (ANL), Argonne, IL (United States); Jin, E. [Argonne National Lab. (ANL), Argonne, IL (United States); Mohamed, W. [Argonne National Lab. (ANL), Argonne, IL (United States); Moisseytsev, A. [Argonne National Lab. (ANL), Argonne, IL (United States); Passerini, S. [Argonne National Lab. (ANL), Argonne, IL (United States); Sienicki, J. [Argonne National Lab. (ANL), Argonne, IL (United States); Sumner, T. [Argonne National Lab. (ANL), Argonne, IL (United States); Vilim, R. [Argonne National Lab. (ANL), Argonne, IL (United States); Hayes, Steven [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-02-29

    The FASTER reactor plant is a sodium-cooled fast spectrum test reactor that provides high levels of fast and thermal neutron flux for scientific research and development. The 120MWe FASTER reactor plant has a superheated steam power conversion system which provides electrical power to a local grid allowing for recovery of operating costs for the reactor plant.

  9. ADAPTIVE CONTROL SYSTEM OF INDUSTRIAL REACTORS

    Directory of Open Access Journals (Sweden)

    Vyacheslav K. Mayevski

    2014-01-01

    Full Text Available This paper describes a mathematical model of an industrial chemical reactor for production of synthetic rubber. During reactor operation the model parameters vary considerably. To create a control algorithm performed transformation of mathematical model of the reactor in order to obtain a dependency that can be used to determine the model parameters are changing during reactor operation.

  10. Nuclear research reactors activities in INVAP

    Energy Technology Data Exchange (ETDEWEB)

    Ordonez, Juan Pablo [INVAP, Bariloche (Argentina)

    2013-07-01

    This presentation describes the different activities in the research reactor field that are being carried out by INVAP. INVAP is presently involved in the design of three new research reactors in three different countries. The RA-10 is a multipurpose reactor, in Argentina, planned as a replacement for the RA-3 reactor. INVAP was contracted by CNEA for carrying out the preliminary engineering for this reactor, and has recently been contracted by CNEA for the detailed engineering. CNEA groups are strongly involved in the design of this reactor. The RMB is a multipurpose reactor, planned by CNEN from Brazil. CNEN, through REDETEC, has contracted INVAP to carry out the preliminary engineering for this reactor. As the user requirements for RA-10 and RMB are very similar, an agreement was signed between Argentina and Brasil governments to cooperate in these two projects. The agreement included that both reactors would use the OPAL reactor in Australia, design and built by INVAP, as a reference reactor. INVAP has also designed the LPRR reactor for KACST in Saudi Arabia. The LPRR is a 30 kw reactor for educational purposes. KACST initially contracted INVAP for the engineering for this reactor and has recently signed the contract with INVAP for building the reactor. General details of these three reactors will be presented.

  11. Advanced multi-dimensional deterministic transport computational capability for safety analysis of pebble-bed reactors

    Science.gov (United States)

    Tyobeka, Bismark Mzubanzi

    A coupled neutron transport thermal-hydraulics code system with both diffusion and transport theory capabilities is presented. At the heart of the coupled code is a powerful neutronics solver, based on a neutron transport theory approach, powered by the time-dependent extension of the well known DORT code, DORT-TD. DORT-TD uses a fully implicit time integration scheme and is coupled via a general interface to the thermal-hydraulics code THERMIX-DIREKT, an HTR-specific two dimensional core thermal-hydraulics code. Feedback is accounted for by interpolating multigroup cross sections from pre-generated libraries which are structured for user specified discrete sets of thermal-hydraulic parameters e.g. fuel and moderator temperatures. The coupled code system is applied to two HTGR designs, the PBMR 400MW and the PBMR 268MW. Steady-state and several design basis transients are modeled in an effort to discern with the adequacy of using neutron diffusion theory as against the more accurate but yet computationally expensive neutron transport theory. It turns out that there are small but significant differences in the results from using either of the two theories. It is concluded that diffusion theory can be used with a higher degree of confidence in the PBMR as long as more than two energy groups are used and that the result must be checked against lower order transport solution, especially for safety analysis purposes. The end product of this thesis is a high fidelity, state-of-the-art computer code system, with multiple capabilities to analyze all PBMR safety related transients in an accurate and efficient manner.

  12. Advanced Carbothermal Electric Reactor Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The overall objective of the Phase 1 effort was to demonstrate the technical feasibility of the Advanced Carbothermal Electric (ACE) Reactor concept. Unlike...

  13. Thermal Analysis for Mobile Reactor

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>Mobile reactor design in the paper is consisted of two grades of thermal electric conversion. The first grade is the thermionic conversion inside the core and the second grade is thermocouple conversion

  14. Advanced Carbothermal Electric Reactor Project

    Data.gov (United States)

    National Aeronautics and Space Administration — ORBITEC proposes to develop the Advanced Carbothermal Electric (ACE) reactor to efficiently extract oxygen from lunar regolith. Unlike state-of-the-art carbothermal...

  15. Teaching About Nature's Nuclear Reactors

    CERN Document Server

    Herndon, J M

    2005-01-01

    Naturally occurring nuclear reactors existed in uranium deposits on Earth long before Enrico Fermi built the first man-made nuclear reactor beneath Staggs Field in 1942. In the story of their discovery, there are important lessons to be learned about scientific inquiry and scientific discovery. Now, there is evidence to suggest that the Earth's magnetic field and Jupiter's atmospheric turbulence are driven by planetary-scale nuclear reactors. The subject of planetocentric nuclear fission reactors can be a jumping off point for stimulating classroom discussions about the nature and implications of planetary energy sources and about the geomagnetic field. But more importantly, the subject can help to bring into focus the importance of discussing, debating, and challenging current thinking in a variety of areas.

  16. Reactor containment research and development

    Energy Technology Data Exchange (ETDEWEB)

    Weil, N. A.

    1963-06-15

    An outline is given of containment concepts, sources and release rates of energy, responses of containment structures, effects of projectiles, and leakage rates of radioisotopes, with particular regard to major reactor accidents. (T.F.H.)

  17. Reactor operation environmental information document

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, L.R.; Hayes, D.W.; Hunter, C.H.; Marter, W.L.; Moyer, R.A.

    1989-12-01

    This volume is a reactor operation environmental information document for the Savannah River Plant. Topics include meteorology, surface hydrology, transport, environmental impacts, and radiation effects. 48 figs., 56 tabs. (KD)

  18. Advanced Catalytic Hydrogenation Retrofit Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Reinaldo M. Machado

    2002-08-15

    Industrial hydrogenation is often performed using a slurry catalyst in large stirred-tank reactors. These systems are inherently problematic in a number of areas, including industrial hygiene, process safety, environmental contamination, waste production, process operability and productivity. This program proposed the development of a practical replacement for the slurry catalysts using a novel fixed-bed monolith catalyst reactor, which could be retrofitted onto an existing stirred-tank reactor and would mitigate many of the minitations and problems associated with slurry catalysts. The full retrofit monolith system, consisting of a recirculation pump, gas/liquid ejector and monolith catalyst, is described as a monolith loop reactor or MLR. The MLR technology can reduce waste and increase raw material efficiency, which reduces the overall energy required to produce specialty and fine chemicals.

  19. Unique features of space reactors

    Science.gov (United States)

    Buden, David

    Space reactors are designed to meet a unique set of requirements; they must be sufficiently compact to be launched in a rocket to their operational location, operate for many years without maintenance and servicing, operate in extreme environments, and reject heat by radiation to space. To meet these restrictions, operating temperatures are much greater than in terrestrial power plants, and the reactors tend to have a fast neutron spectrum. Currently, a new generation of space reactor power plants is being developed. The major effort is in the SP-100 program, where the power plant is being designed for seven years of full power, and no maintenance operation at a reactor outlet operating temperature of 1350 K.

  20. Jules Horowitz Reactor, basic design

    Energy Technology Data Exchange (ETDEWEB)

    Bergamaschi, Y.; Bouilloux, Y.; Chantoin, P.; Guigon, B.; Bravo, X.; Germain, C.; Rommens, M.; Tremodeux, P

    2003-07-01

    Since the shutdown of the SILOE reactor in 1997, the OSIRIS reactor has ensured the needs regarding technological irradiation at CEA including those of its industrial partners and customers. The Jules Horowitz Reactor will replace it. It has the ambition to provide the necessary nuclear data and maintain a fission research capacity in Europe after 2010. This capacity should be service-oriented. It will be established in Cadarache. The Jules Horowitz reactor will also: - represent a significant step in term of performances and experimental capabilities, - be designed with a high flexibility, in order to satisfy the current demand from European industry, research and be able to accommodate future requirements, - reach a high level of safety, according to the best current practice. This paper will present the main functionalities and the design options resulting from the 'preliminary design' studies. (authors)

  1. Solid State Reactor Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Mays, G.T.

    2004-03-10

    The Solid State Reactor (SSR) is an advanced reactor concept designed to take advantage of Oak Ridge National Laboratory's (ORNL's) recently developed graphite foam that has enhanced heat transfer characteristics and excellent high-temperature mechanical properties, to provide an inherently safe, self-regulated, source of heat for power and other potential applications. This work was funded by the U.S. Department of Energy's Nuclear Energy Research Initiative (NERI) program (Project No. 99-064) from August 1999 through September 30, 2002. The initial concept of utilizing the graphite foam as a basis for developing an advanced reactor concept envisioned that a suite of reactor configurations and power levels could be developed for several different applications. The initial focus was looking at the reactor as a heat source that was scalable, independent of any heat removal/power conversion process. These applications might include conventional power generation, isotope production and destruction (actinides), and hydrogen production. Having conducted the initial research on the graphite foam and having performed the scoping parametric analyses from neutronics and thermal-hydraulic perspectives, it was necessary to focus on a particular application that would (1) demonstrate the viability of the overall concept and (2) require a reasonably structured design analysis process that would synthesize those important parameters that influence the concept the most as part of a feasible, working reactor system. Thus, the application targeted for this concept was supplying power for remote/harsh environments and a design that was easily deployable, simplistic from an operational standpoint, and utilized the new graphite foam. Specifically, a 500-kW(t) reactor concept was pursued that is naturally load following, inherently safe, optimized via neutronic studies to achieve near-zero reactivity change with burnup, and proliferation resistant. These four major areas

  2. Reactor antineutrinos and nuclear physics

    Science.gov (United States)

    Balantekin, A. B.

    2016-11-01

    Short-baseline reactor neutrino experiments successfully measured the neutrino parameters they set out to measure, but they also identified a shape distortion in the 5-7 MeV range as well as a reduction from the predicted value of the flux. Nuclear physics input into the calculations of reactor antineutrino spectra needs to be better refined if this anomaly is to be interpreted as due to sterile neutrino states.

  3. Microchannel Reactors for ISRU Applications

    Science.gov (United States)

    Carranza, Susana; Makel, Darby B.; Blizman, Brandon; Ward, Benjamin J.

    2005-02-01

    Affordable planning and execution of prolonged manned space missions depend upon the utilization of local resources and the waste products which are formed in manned spacecraft and surface bases. Successful in-situ resources utilization (ISRU) will require component technologies which provide optimal size, weight, volume, and power efficiency. Microchannel reactors enable the efficient chemical processing of in situ resources. The reactors can be designed for the processes that generate the most benefit for each mission. For instance, propellants (methane) can be produced from carbon dioxide from the Mars atmosphere using the Sabatier reaction and ethylene can be produced from the partial oxidation of methane. A system that synthesizes ethylene could be the precursor for systems to synthesize ethanol and polyethylene. Ethanol can be used as a nutrient for Astrobiology experiments, as well as the production of nutrients for human crew (e.g. sugars). Polyethylene can be used in the construction of habitats, tools, and replacement parts. This paper will present recent developments in miniature chemical reactors using advanced Micro Electro Mechanical Systems (MEMS) and microchannel technology to support ISRU of Mars and lunar missions. Among other applications, the technology has been demonstrated for the Sabatier process and for the partial oxidation of methane. Microchannel reactors were developed based on ceramic substrates as well as metal substrates. In both types of reactors, multiple layers coated with catalytic material are bonded, forming a monolithic structure. Such reactors are readily scalable with the incorporation of extra layers. In addition, this reactor structure minimizes pressure drop and catalyst settling, which are common problems in conventional packed bed reactors.

  4. The resonance absorption controlled reactor

    Energy Technology Data Exchange (ETDEWEB)

    Caro, R.

    1977-07-01

    In this report a new method of reactor control based on tho isotopic moderator composition variation is studied, taking as a reference a D{sub 2}O/H{sub 2}O system. With this method an spectacular increment in the burn-up degree and a sensible reduction of the conventional control system is obtained. An important part of this work has been the detailed analysis of the parameters affecting the neutron spectrum in a heterogeneous reactor. (Author) 50 refs.

  5. Calculation of reactor antineutrino spectra in TEXONO

    CERN Document Server

    Chen Dong Liang; Mao Ze Pu; Wong, T H

    2002-01-01

    In the low energy reactor antineutrino physics experiments, either for the researches of antineutrino oscillation and antineutrino reactions, or for the measurement of abnormal magnetic moment of antineutrino, the flux and the spectra of reactor antineutrino must be described accurately. The method of calculation of reactor antineutrino spectra was discussed in detail. Furthermore, based on the actual circumstances of NP2 reactors and the arrangement of detectors, the flux and the spectra of reactor antineutrino in TEXONO were worked out

  6. LMFBR type reactor

    Energy Technology Data Exchange (ETDEWEB)

    Iwashige, Kengo

    1996-06-21

    In an LMFBR type reactor, partitions are disposed to a coolant channel at positions lower than the free liquid level, and the width of the partitions is adapted to have a predetermined condition. Namely, when low temperature fluid overflowing the wall of the coolant channel, flows down and collided against the free liquid surface in the coolant channel, since the dropping speed thereof is reduced abruptly, large pressure waves are caused by kinetic force of the low temperature fluid. However, if appropriate numbers of partitions having an appropriate shape are formed, the dropping speed of the low temperature fluid is moderated to reduce the pressure waves. In addition, since the pressure waves are dispersed to the circumferential and lateral directions of the coolant flow channel respectively, the propagation of the pressure waves can be prevented effectively. Further, when the flow of the low temperature fluid is changed to the circumferential direction, for example, by earthquakes, since the partitions act as members resisting against the circumferential change of the low temperature fluid, the change of the direction can be suppressed. (N.H.)

  7. Reactor Simulator Testing

    Science.gov (United States)

    Schoenfeld, Michael P.; Webster, Kenny L.; Pearson, Boise J.

    2013-01-01

    As part of the Nuclear Systems Office Fission Surface Power Technology Demonstration Unit (TDU) project, a reactor simulator test loop (RxSim) was design & built to perform integrated testing of the TDU components. In particular, the objectives of RxSim testing was to verify the operation of the core simulator, the instrumentation and control system, and the ground support gas and vacuum test equipment. In addition, it was decided to include a thermal test of a cold trap purification design and a pump performance test at pump voltages up to 150 V since the targeted mass flow rate of 1.75 kg/s was not obtained in the RxSim at the originally constrained voltage of 120 V. This paper summarizes RxSim testing. The gas and vacuum ground support test equipment performed effectively in NaK fill, loop pressurization, and NaK drain operations. The instrumentation and control system effectively controlled loop temperature and flow rates or pump voltage to targeted settings. The cold trap design was able to obtain the targeted cold temperature of 480 K. An outlet temperature of 636 K was obtained which was lower than the predicted 750 K but 156 K higher than the cold temperature indicating the design provided some heat regeneration. The annular linear induction pump (ALIP) tested was able to produce a maximum flow rate of 1.53 kg/s at 800 K when operated at 150 V and 53 Hz.

  8. Novel Catalytic Membrane Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Stuart Nemser, PhD

    2010-10-01

    There are many industrial catalytic organic reversible reactions with amines or alcohols that have water as one of the products. Many of these reactions are homogeneously catalyzed. In all cases removal of water facilitates the reaction and produces more of the desired chemical product. By shifting the reaction to right we produce more chemical product with little or no additional capital investment. Many of these reactions can also relate to bioprocesses. Given the large number of water-organic compound separations achievable and the ability of the Compact Membrane Systems, Inc. (CMS) perfluoro membranes to withstand these harsh operating conditions, this is an ideal demonstration system for the water-of-reaction removal using a membrane reactor. Enhanced reaction synthesis is consistent with the DOE objective to lower the energy intensity of U.S. industry 25% by 2017 in accord with the Energy Policy Act of 2005 and to improve the United States manufacturing competitiveness. The objective of this program is to develop the platform technology for enhancing homogeneous catalytic chemical syntheses.

  9. Tritium management in fusion reactors

    Energy Technology Data Exchange (ETDEWEB)

    Galloway, T.R.

    1978-05-01

    This is a review paper covering the key environmental and safety issues and how they have been handled in the various magnetic and inertial confinement concepts and reference designs. The issues treated include: tritium accident analyses, tritium process control, occupational safety, HTO formation rate from the gas-phase, disposal of tritium contaminated wastes, and environmental impact--each covering the Joint European Tokamak (J.E.T. experiment), Tokamak Fusion Test Reactor (TFTR), Russian T-20, The Next Step (TNS) designs by Westinghouse/ORNL and General Atomic/ANL, the ANL and ORNL EPR's, the G.A. Doublet Demonstration Reactor, the Italian Fintor-D and the ORNL Demo Studies. There are also the following full scale plant reference designs: UWMAK-III, LASL's Theta Pinch Reactor Design (RTPR), Mirror Fusion Reactor (MFR), Tandem Mirror Reactor (TMR), and the Mirror Hybrid Reactor (MHR). There are four laser device breakeven experiments, SHIVA-NOVA, LLL reference designs, ORNL Laser Fusion power plant, the German ''Saturn,'' and LLL's Laser Fusion EPR I and II.

  10. Materiales magnéticos moleculares: Diseño de imanes quirales basados en cianuros bimetálicos y de agentes de contraste en IRM basados en complejos metálicos con radicales libres.

    OpenAIRE

    2009-01-01

    RESUMEN El primer capítulo de esta Tesis trata del diseño de imanes quirales basados en cianuros bimetálicos. Se presenta la síntesis y caracterización de diez análogos del azul de Prusia del tipo Ni3Fe2 y Cu3Fe2 obtenidos con los ligandos trans-chxn, trans-(1S,2S)-chxn, trans-(1R,2R)-chxn y cis-chxn (chxn = ciclohexano-1,2-diamina): [Ni(trans-chxn)2]3[Fe(CN)6]22H2O (1), [Ni(cis-chxn)2]3[Fe(CN)6]22H2O (2), [Ni(trans-(1S,2S)-chxn)2]3[Fe(CN)6]22H2O (3), [Ni(trans-(1R,2R)-chxn)2]3[Fe(CN)6]22H...

  11. Proyecto y evaluación del comportamiento sísmico de estructuras de hormigón armado basado en desplazamientos

    OpenAIRE

    Huaman Cevalos, Victor Michael

    2010-01-01

    Esta tesina trata de aplicar el método directo de diseño sísmico basado en desplazamientos DDBD a un edificio de hormigón armado para evaluar y comparar los resultados con los obtenidos del método basado en fuerzas según el EHE. La estructura principal de análisis es un edificio de 6 plantas de oficinas de importancia especial y ubicada en una zona de alta sismicidad en España. Para la evaluación final de los diseños se emplea el análisis estático no lineal con el cual se obtienen...

  12. Evaluación de colecciones en bibliotecas universitarias (II). Métodos basados en el estudio de la colección.

    OpenAIRE

    Massísimo i Sánchez de Boado, Angels

    2004-01-01

    Como continuación del trabajo sobre métodos de evaluación basados en el estudio de la colección en sí misma, se presentan siete métodos alternativos de evaluación de la colección, basados esta vez en estudios sobre el uso de la colección. Se presenta en forma breve cada método y se describen sus ventajas e inconvenien-tes, así como la aplicabilidad de cada uno para diferentes tipos de colección. ABSTRACT: This is our second paper devoted to the collection evaluation in the university libra...

  13. Innovative hybrid biological reactors using membranes; Reactores biologico hibrido innovadores utilizando membranas

    Energy Technology Data Exchange (ETDEWEB)

    Diez, R.; Esteban-Garcia, A. L.; Florio, L. de; Rodriguez-Hernandez, L.; Tejero, I.

    2011-07-01

    In this paper we present two lines of research on hybrid reactors including the use of membranes, although with different functions: RBPM, biofilm reactors and membranes filtration RBSOM, supported biofilm reactors and oxygen membranes. (Author) 14 refs.

  14. Establishment of licensing process for development reactors

    Energy Technology Data Exchange (ETDEWEB)

    Jo, Jong Chull; Yune, Young Gill; Kim, Woong Sik (and others)

    2006-02-15

    A study on licensing processes for development reactors has been performed to prepare the licensing of development reactors developed in Korea. The contents and results of the study are summarized as follows. The licensing processes for nuclear reactors in Korea, U.S.A., Japan, France, U.K., Canada, and IAEA were surveyed and analyzed to obtain technical bases necessary for establishing licensing processes applicable to development reactors in Korea. Based on the technical bases obtained the above analysis, the purpose, power output, and design characteristics of development reactors were analyzed in detail. The analysis results suggested that development reactors should be classified as a new reactor category (called as 'development reactor') separated from the current reactor categories such as the research reactor and the power reactor. Therefore, it is proposed to establish a new reactor category classified as 'development reactor' for the development reactors. And licensing processes, including licensing technical requirements, licensing document requirements, and other regulatory requirements, were also proposed for the development reactors. In order to institutionalize the licensing processes developed in this study, it is necessary to revise the current laws. Therefore, draft provisions of Atomic Energy Act, Enforcement Decree of the Atomic Energy Act, and Enforcement Regulation of the Atomic Energy Act have been developed for the preparation of the future legalization of the licensing processes proposed for the development reactors. Conclusively, a proposal of licensing processes and draft provisions of laws have been developed for the development reactors. The results proposed in this study can be applied directly to the licensing of the future development reactors. Furthermore, they will also contribute to establishing successfully the licensing processes of the development reactors.

  15. Efecto de un programa de entrenamiento físico basado en la secuencia de desarrollo sobre el balance postural en futbolistas: ensayo controlado aleatorizado

    OpenAIRE

    Erica Mancera-Soto; Édgar Hernández-Álvarez; Fabián Hernández-Salinas; Laura Prieto-Mondragon; Leidy Quiroga-Díaz

    2014-01-01

    Antecedentes. En la actividad deportiva, el balance postural es requerido para mantener la estabilidad durante el juego. Por tanto, existe una necesidad de determinar si el aprendizaje motor desde posiciones funcionales, movimientos coordinados están implicados en los deportes. Objetivo. El objetivo de este estudio fue determinar el efecto de un entrenamiento físico basado en la secuencia de desarrollo sobre el balance postural en futbolistas de la selección de la Universidad Nacional de Colo...

  16. Sistema de evaluación para el Aprendizaje Basado en Problemas (ABP en estudiantes de la licenciatura en nutrición

    Directory of Open Access Journals (Sweden)

    Salvador Ruiz Cerrillo

    2016-03-01

    Full Text Available Según la literatura existente, una de las dificultades principales en la evaluación de actividades en el ABP es la definición de los instrumentos que pueden utilizarse para una evaluación formal. El presente artículo tiene como objetivo proponer un sistema de evaluación para el ABP en alumnos de la licenciatura en nutrición. Se trata de un estudio con un paradigma de tipo mixto, desde un modelo secuencial y exploratorio por etapas, donde se emplearon tres instrumentos de naturaleza mixta (cualitativa y cuantitativa para la recolección sistemática de los datos: cuestionario de evaluación del desempeño de los estudiantes durante las sesiones tutoriales del aprendizaje basado en problemas, escala de evaluación de elementos esenciales del desempeño de un tutor de aprendizaje basado en problemas (ABP y escala de autoevaluación para el alumno de diseño propio. En los resultados, la dimensión mejor evaluada por parte del tutor fue la interacción con el grupo, con un valor promedio de 34.68 de 36 puntos, en la escala de evaluación de elementos esenciales del desempeño de un tutor de Aprendizaje Basado en Problemas (ABP la media más alta fue de 3 (+/- 0 para el ítem número 1 que evalúa si el facilitador está bien informado acerca del proceso de aprendizaje basado en problemas; para el instrumento de autoevaluación del alumno se reportó que el valor promedio más alto fue el del ítem número 2 (4.41 +/- 0.57, el cual evalúa la claridad en la instrucción del tutor.

  17. Diseño de un modelo de evaluación de entornos virtuales de enseñanza y aprendizaje basado en la usabilidad

    Directory of Open Access Journals (Sweden)

    Ferreira Szpiniak, Ariel

    2013-06-01

    Full Text Available El aporte fundamental de la tesis se basa en una propuesta de evaluación de EVEA para medir características de usabilidad de los mismos. La hemos denominado MUsa, dado que se trata de un Modelo basado en la Usabilidad. El énfasis puesto en la usabilidad se debe fundamentalmente a su creciente importancia dentro de la calidad de los productos Web.

  18. Repairing liner of the reactor; Reparacion del liner del reactor

    Energy Technology Data Exchange (ETDEWEB)

    Aguilar H, F. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    2001-07-15

    Due to the corrosion problems of the aluminum coating of the reactor pool, a periodic inspections program by ultrasound to evaluate the advance grade and the corrosion speed was settled down. This inspections have shown the necessity to repair some areas, in those that the slimming is significant, of not making it can arrive to the water escape of the reactor pool. The objective of the repair is to place patches of plates of 1/4 inch aluminum thickness in the areas of the reactor 'liner', in those that it has been detected by ultrasound a smaller thickness or similar to 3 mm. To carry out this the fuels are move (of the core and those that are decaying) to a temporary storage, the structure of the core is confined in a tank that this placed inside the pool of the reactor, a shield is placed in the thermal column and it is completely extracted the water for to leave uncover the 'liner' of the reactor. (Author)

  19. Cynod: A Neutronics Code for Pebble Bed Modular Reactor Coupled Transient Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Hikaru Hiruta; Abderrafi M. Ougouag; Hans D. Gougar; Javier Ortensi

    2008-09-01

    The Pebble Bed Reactor (PBR) is one of the two concepts currently considered for development into the Next Generation Nuclear Plant (NGNP). This interest is due, in particular, to the concept’s inherent safety characteristics. In order to verify and confirm the design safety characteristics of the PBR computational tools must be developed that treat the range of phenomena that are expected to be important for this type of reactors. This paper presents a recently developed 2D R-Z cylindrical nodal kinetics code and shows some of its capabilities by applying it to a set of known and relevant benchmarks. The new code has been coupled to the thermal hydraulics code THERMIX/KONVEK[1] for application to the simulation of very fast transients in PBRs. The new code, CYNOD, has been written starting with a fixed source solver extracted from the nodal cylindrical geometry solver contained within the PEBBED code. The fixed source solver was then incorporated into a kinetic solver.. The new code inherits the spatial solver characteristics of the nodal solver within PEBBED. Thus, the time-dependent neutron diffusion equation expressed analytically in each node of the R-Z cylindrical geometry sub-domain (or node) is transformed into one-dimensional equations by means of the usual transverse integration procedure. The one-dimensional diffusion equations in each of the directions are then solved using the analytic Green’s function method. The resulting equations for the entire domain are then re-cast in the form of the Direct Coarse Mesh Finite Difference (D-CMFD) for convenience of solution. The implicit Euler method is used for the time variable discretization. In order to correctly treat the cusping effect for nodes that contain a partially inserted control rod a method is used that takes advantage of the Green’s function solution available in the intrinsic method. In this corrected treatment, the nodes are re-homogenized using axial flux shapes reconstructed based on the

  20. Reactor Simulator Testing

    Science.gov (United States)

    Schoenfeld, Michael P.; Webster, Kenny L.; Pearson, Boise Jon

    2013-01-01

    As part of the Nuclear Systems Office Fission Surface Power Technology Demonstration Unit (TDU) project, a reactor simulator test loop (RxSim) was design & built to perform integrated testing of the TDU components. In particular, the objectives of RxSim testing was to verify the operation of the core simulator, the instrumentation and control system, and the ground support gas and vacuum test equipment. In addition, it was decided to include a thermal test of a cold trap purification design and a pump performance test at pump voltages up to 150 V since the targeted mass flow rate of 1.75 kg/s was not obtained in the RxSim at the originally constrained voltage of 120 V. This paper summarizes RxSim testing. The gas and vacuum ground support test equipment performed effectively in NaK fill, loop pressurization, and NaK drain operations. The instrumentation and control system effectively controlled loop temperature and flow rates or pump voltage to targeted settings. The cold trap design was able to obtain the targeted cold temperature of 480 K. An outlet temperature of 636 K was obtained which was lower than the predicted 750 K but 156 K higher than the cold temperature indicating the design provided some heat regeneration. The annular linear induction pump (ALIP) tested was able to produce a maximum flow rate of 1.53 kg/s at 800 K when operated at 150 V and 53 Hz. Keywords: fission, space power, nuclear, liquid metal, NaK.

  1. Plutonium and Minor Actinide Management in Thermal High-Temperature Gas-Cooled Reactors. Publishable Final Activity Report

    Energy Technology Data Exchange (ETDEWEB)

    Kuijper, J.C., E-mail: kuijper@nrg.eu [Nuclear Research and Consultancy Group (NRG), Petten (Netherlands); Somers, J.; Van Den Durpel, L.; Chauvet, V.; Cerullo, N.; Cetnar, J.; Abram, T.; Bakker, K.; Bomboni, E.; Bernnat, W.; Domanska, J.G.; Girardi, E.; De Haas, J.B.M.; Hesketh, K.; Hiernaut, J.P.; Hossain, K.; Jonnet, J.; Kim, Y.; Kloosterman, J.L.; Kopec, M.; Murgatroyd, J.; Millington, D.; Lecarpentier, D.; Lomonaco, G.; McEachern, D.; Meier, A.; Mignanelli, M.; Nabielek, H.; Oppe, J.; Petrov, B.Y.; Pohl, C.; Ruetten, H.J.; Schihab, S.; Toury, G.; Trakas, C.; Venneri, F.; Verfondern, K.; Werner, H.; Wiss, T.; Zakova, J.

    2010-11-15

    The PUMA project -the acronym stands for 'Plutonium and Minor Actinide Management in Thermal High-Temperature Gas-Cooled Reactors'- was a Specific Targeted Research Project (STREP) within the EURATOM 6th Framework Program (EU FP6). The PUMA project ran from September 1, 2006, until August 31, 2009, and was executed by a consortium of 14 European partner organisations and one from the USA. This report serves 2 purposes. It is both the 'Publishable Final Activity Report' and the 'Final (Summary) Report', describing, per Work Package, the specific objectives, research activities, main conclusions, recommendations and supporting documents. PUMA's main objective was to investigate the possibilities for the utilisation and transmutation of plutonium and especially minor actinides in contemporary and future (high temperature) gas-cooled reactor designs, which are promising tools for improving the sustainability of the nuclear fuel cycle. This contributes to the reduction of Pu and MA stockpiles, and also to the development of safe and sustainable reactors for CO{sub 2}-free energy generation. The PUMA project has assessed the impact of the introduction of Pu/MA-burning HTRs at three levels: fuel and fuel performance (modelling), reactor (transmutation performance and safety) and reactor/fuel cycle facility park. Earlier projects already indicated favourable characteristics of HTRs with respect to Pu burning. So, core physics of Pu/MA fuel cycles for HTRs has been investigated to study the CP fuel and reactor characteristics and to assure nuclear stability of a Pu/MA HTR core, under both normal and abnormal operating conditions. The starting point of this investigation comprised the two main contemporary HTR designs, viz. the pebble-bed type HTR, represented by the South-African PBMR, and hexagonal block type HTR, represented by the GT-MHR. The results (once again) demonstrate the flexibility of the contemporary (and near future) HTR

  2. JMat - Herramienta remota de cálculo y multiusuario para el aprendizaje basado en problemas usando Matlab

    Directory of Open Access Journals (Sweden)

    Bladimir Bacca Cortes

    2011-01-01

    Full Text Available JMat es una herramienta de cálculo basada en JAVA y EJS (Easy Java Simulations, con un esquema cliente / servidor, soporte multi-usuario y acceso remoto a Matlab. La aplicación está orientada a brindar a los usuarios una interacción con Matlab usando tres interfaces: Consola de Comandos, donde se invocan remotamente comandos de texto compatibles con Matlab. Espacio de Trabajo y Graficación, donde se mantiene un registro automático de las variables de usuario y se grafican individualmente. Funciones de usuario y Transferencia de Archivos, donde el usuario crea sus funciones, envía y recibe datos hacia y desde el servidor. JMat requiere un acceso a Internet, un servidor remoto donde esté instalado Matlab y un cliente (Navegador WEB o aplicación. No se requiere Matlab en el cliente. JMat está siendo usada actualmente en la Universidad del Valle en los cursos de Control Automático de Procesos, Control Inteligente, Redes Neuronales Artificiales, Procesamiento de Señales y Tratamiento Digital de Imágenes como herramienta para el aprendizaje basado en problemas empleando la plataforma de eLearning de la Universidad del Valle.

  3. Enfoque “Aprendizaje Basado en Proyectos” para enseñar sistemas de potencia de gas y vapor

    Directory of Open Access Journals (Sweden)

    Asier Aranzábal

    2014-12-01

    Full Text Available El objetivo de este trabajo es presentar la experiencia y los resultados derivados de la aplicación del método Aprendizaje Basado en Proyectos (PBL en la asignatura Termotecnia de la Titulación de Ingeniería Química de la Universidad del País Vasco/Euskal Herriko Unibertsitatea, para aprender sistemas de potencia de gas y vapor. Tras un análisis crítico de los resultados académicos de los alumnos que aprenden estos sistemas, se observa que la estrategia de enseñanza-aprendizaje tradicional, basada en clases “magistrales + clases de aplicación en una lista de ejercicios (totalmente acotados y con una solución única, estaba fallando. Ante esta situación se plantea un enfoque constructivista centrado en el alumno para que él mismo construya su aprendizaje activa y cooperativamente, y no escuchando clases magistrales, ni memorizando.

  4. RECUPERACIÓN DE IMÁGENES EN LA WEB: SISTEMA PROTOTIPO BASADO EN CONTENIDO Y MANEJO DE CALIDAD

    Directory of Open Access Journals (Sweden)

    Bell Manrique Losada

    2007-01-01

    Full Text Available El presente artículo muestra una revisión de las investigaciones realizadas acerca de la recuperación de imágenes en colecciones digitales en la web, basado en su contenido y en el manejo de la calidad de la información. Teniendo en cuenta este estado del arte, se presenta una propuesta metodológica para el diseño e implementación de un prototipo de sistema de recuperación de imágenes que utilice estas dos técnicas de búsqueda: recuperación basada en contenido y recuperación manejando calidad de la información y, por último, se muestran los avances en el desarrollo de la propuesta.This article presents a compilation of the researches carried on the image recovery from web digital collections, based upon their contents and data quality management. Using this state-of-the-art study as a support, the article presents a methodological proposal to design and implement a system prototype in image recovery that uses these two search techniques; and finally the article presents the progress achieved in developing this proposal.

  5. CARACTERIZACIÓN DEL TALLO ACEPTOR DEL tRNA MEDIANTE DESCRIPTORES LOCALES BASADOS EN CARGAS PARCIALES

    Directory of Open Access Journals (Sweden)

    Ray Marín

    2009-04-01

    Full Text Available En este trabajo se caracteriza la distribución de carga del tallo aceptor del tRNA, considerando todas las posibles combinaciones de pares Watson-Crick. El estudio se realizó con 256 fragmentos moleculares de 10 nucleótidos que modelan los tres primeros pares del tallo aceptor, la base diferenciadora y el extremo CCA. Para caracterizar los nucleótidos se proponen dos descriptores locales basados en la distribución de carga de las base nitrogenada de cada nucleótido, los cuales se calculan a partir de las cargas parciales de Mulliken obtenidas de cálculos HF/6-31G. La caracterización y clasificación de los tallos según estos descriptores mostró como la base diferenciadora tiene un comportamiento particular respecto a los demás nucleótidos del tallo y una fuerte influencia sobre el extremo CCA. La clasificación de nueve variaciones del tallo aceptor del tRNAAla mostró una buena relación estructura-actividad que pone en evidencia la bondad de los descriptores propuestos para caracterizar de manera local la distribución de carga de estas biomoléculas. 

  6. Un enfoque basado en competencias de sistemas multiagentes para la enseñanza de Inteligencia Artificial

    Directory of Open Access Journals (Sweden)

    Cecchi, Laura

    2010-01-01

    Full Text Available En este trabajo se presenta un enfoque basado en competencias de sistemas multiagentes como fundamento de la enseñanza de tópicos avanzados en Inteligencia Artificial. La metodología fue implementada en la materia optativa Robótica Cognitiva con alumnos del 5to. año de la carrera Licenciatura en Ciencias de la Computación, de la Universidad Nacional del Comahue, en un dominio que es conocido y divertido: el fútbol. Los campeonatos que se realizan entre los diferentes equipos permiten que los estudiantes evalúen y comparen los resultados. La motivación que se logra es fundamental para despertar interés en el estudio de técnicas la Inteligencia Artificial y en la investigación en general. Se presentan la experiencia desarrollada, un análisis de la metodología y el impacto en el dominio académico y de investigación.

  7. Nuevo enfoque para desarrollar sistemas de enseñanza-aprendizaje inteligentes usando mapas conceptuales y razonamiento basado en casos

    Directory of Open Access Journals (Sweden)

    Zenaida García Valdivia

    2011-10-01

    Full Text Available El uso de métodos pedagógicos con tecnologías de la información y las comunicaciones produce una cualidad nueva que favorece la tarea de generar, transmitir y compartir el conocimiento. Tal es el caso de la fortaleza pedagógica del empleo de los Mapas Conceptuales, que constituyen una herramienta para la gestión del conocimiento, por la posibilidad que estos ofrecen de personalizar el aprendizaje, compartir conocimiento, y para aprender a aprender. En este trabajo se expone un nuevo enfoque para elaborar Sistemas de Enseñanza-Aprendizaje Inteligentes, donde se combinan las técnicas de diagramas conceptuales e Inteligencia Artificial, usando el Razonamiento Basado en Casos como marco teórico para el modelado del alumno. El modelo propuesto se ha implementado en el sistema computacional HESEI, el cual ha sido aplicado exitosamente en la toma de decisiones en tareas de enseñanza-aprendizaje, por personas no expertas en el campo informático.

  8. DESARROLLO DE UN SOFTWARE BASADO EN JAVA CAPAZ DE INTERPRETAR TRAZAS DE ARCHIVOS GENERADOS POR NS-2

    Directory of Open Access Journals (Sweden)

    Fredy Pachón Barbera

    2013-09-01

    Full Text Available En la simulación de una red de datos, se trata de evaluar, investigar y/o analizar su comportamiento  en un ambiente real, siempre buscando la optimización los recursos. El análisis de la información es un punto clave para conocer fortalezas y debilidades de la red simulada. El objetivo de este artículo es mostrar el desarrollo de una herramienta de interpretación de trazas generadas por NS-2 basado en el lenguaje de programación Java  y las variables estadísticas que se tuvieron en cuenta para la implementación, con el fin de facilitar el análisis de redes simuladas con la herramienta network simluator. Finalmente se logra la construcción del software, logrando determinar los cálculos de jitter, throughput y bytes enviados por cada nodo, a partir de las trazas generadas por NS-2.

  9. CUESTIONARIO DE EJERCICIO BASADO EN EL MODELO TRANSTEÓRICO DE LA CONDUCTA EN UNA MUESTRA MEXICANA

    Directory of Open Access Journals (Sweden)

    Óscar Armando Esparza del Villar

    2013-01-01

    Full Text Available Se elaboró un cuestionario de ejercicio basado en el modelo transteórico de cambio de la conducta propuesto por Prochaska y DiClemente. Este cuestionario fue diseñado para medir los cinco factores del modelo: precontemplación, contempla ción, preparación, acción y mantenimiento. Primero se elaboraron los reactivos para cada uno de los factores y después se llevó a cabo un análisis factorial exploratorio para analizar la estructura del cuestionario. La muestra fue de 951 participantes de cinco ciudades mexicanas, con una media de edad de 28.76 años. El análisis factorial exploratorio mostró una estructura compuesta de los cinco factores con pesos factoriales variables. Este cuestionario puede ser útil para identificar la etapa en la que una persona se encuentra en relación con hacer ejercicio, y saber qué técnicas usar en las posibles intervenciones.

  10. Esquema basado en Wavelet para la reducción de ruido online en señales industriales

    Directory of Open Access Journals (Sweden)

    Antonio Cedeño Pozo

    2014-07-01

    Full Text Available En este trabajo se propone un esquema para la reducción de ruido gaussiano online basado en wavelet con ventanas deslizantes para ser utilizado en señales industriales. Este tipo de técnicas se utilizan cuando la señal debe ser tratada a medida que se obtienen las muestras, funcionalidad necesaria en aplicaciones con requerimientos de tiempo real, por ejemplo en sistemas SCADA. El algoritmo introducido en el presente trabajo se diferencia de algoritmos similares en que: en primer término utiliza una selección adaptativa del umbral basada en NeighShrink; adicionalmente reutiliza en lo posible los coeficientes wavelet calculados en pasos anteriores para el procesamiento de cada punto; finalmente utiliza la wavelet Haar en lugar de otros filtros de mayor complejidad computacional. Para la comprobación experimental del nuevo esquema se utilizó un conjunto de señales sintéticas introducido por Donoho y Marron, complementadas por señales adquiridas en procesos reales de plantas industriales. Las pruebas realizadas revelan que el algoritmo propuesto mejora la reducción de ruido online respecto a esquemas similares reportados anteriormente y es computacionalmente menos complejo.

  11. Empleo del aprendizaje basado en problemas (abp. Una propuesta para acercarse a la química verde

    Directory of Open Access Journals (Sweden)

    Marina Lucía Morales Galicia

    2013-05-01

    Full Text Available Los profesores han reflexionado acerca de que la educación ambiental deberá ser formativa, por lo que es importante participar para cambiar esta situación dentro del contexto en la enseñanza de las Ciencias Naturales como parte de incrementar el conocimiento acerca del deterioro del medio ambiente. Este trabajo tiene el propósito de presentar la estrategia Aprendizaje Basado en Problemas (ABP. Para demostrar esta metodología, se presentan los resultados que con esta se obtuvieron gracias a la colaboración tanto de un grupo de alumnos mexicanos del nivel bachillerato, así como de profesores participantes chilenos del nivel secundaria (estudios equivalentes en México. El empleo de esta herramienta didáctica proporcionó un aprendizaje significativo en alumnos y profesores, quienes emplearon sus conocimientos previos para abordar un nuevo aprendizaje, quedando realmente impresionados al enterarse de que el problema propuesto sucedía en su país y de toda la secuela ambiental que generaría el que se siguiera sucediendo o se llevara a cabo. Se consiguió que los participantes aportaran ideas novedosas durante el desarrollo de su trabajo y que aceptaran con gusto la responsabilidad para hacer suyos problemas reales que son parte de su cotidianidad.

  12. Un Nuevo Modelo Basado en Funciones Exponenciales para un Sistema de Levitación Magnética Uniaxial

    Directory of Open Access Journals (Sweden)

    Juan E. Martínez

    2013-01-01

    Full Text Available En este trabajo un nuevo modelo dinámico para un sistema de levitación magnética uniaxial (el cual no se ha reportado en la literatura se desarrolla a partir de principios magnetostáticos. El sistema en mención está compuesto por dos bobinas, utilizadas como actuadores para el control de posición de dos imanes permanentes que deben deslizarse a través de un eje vertical, esta es una configuración muy utilizada en motores con suspensión magnética y en general por cualquier sistema con cojinetes o soportes magnéticos activos. Basados en el modelo amperiano y la ley de Biot-Savart para este sistema, se establecieron mediante cálculos numéricos las relaciones fuerza-distancia entre bobinas e imanes permanentes y entre ambos imanes. Con estas relaciones numéricamente definidas se realizaron ajustes de curva exponenciales para obtener el modelo dinámico no lineal del sistema de suspensión magnética. En este artículo adicionalmente se presenta un modelo linealizado generado a partir del modelo obtenido previamente, demostrando que éste representa correctamente la dinámica del sistema cerca al punto de operación.

  13. El lenguaje ordinario: La clave para el aprendizaje de las matemáticas basados en problemas

    Directory of Open Access Journals (Sweden)

    García Retana, José Ángel

    2015-01-01

    Full Text Available En el año 2012 el Ministerio de Educación Pública de Costa Rica, planteó una nueva propuesta de educación matemática para responder a las exigencias sociales y económicas actuales. Esta propuesta se fundamenta en el aprendizaje basado en problemas (ABP como estrategia metodológica. En el caso del aprendizaje de las matemáticas, tal propuesta demanda considerar la relación que existe entre el lenguaje ordinario y el lenguaje matemático, por cuanto el primero es central en el proceso educativo. Este tipo de aprendizaje se debe conceptualizar en su doble función de herramienta, es decir, para resolver problemas, y como disciplina, dado que el lenguaje matemático permite representar los conceptos que trata, al menos de dos maneras diferentes, la semántica y la gráfico-visual, los cuales en gran medida son determinados por el lenguaje ordinario. Así, el lenguaje ordinario y su campo semántico constituyen el eje transversal para el aprendizaje de esta estrategia metodológica

  14. Reactivity determination in accelerator driven reactors using reactor noise analysis

    Directory of Open Access Journals (Sweden)

    Kostić Ljiljana 1

    2002-01-01

    Full Text Available Feynman-alpha and Rossi-alpha methods are used in traditional nuclear reactors to determine the subcritical reactivity of a system. The methods are based on the measurement of the mean value, variance and the covariance of detector counts for different measurement times. Such methods attracted renewed attention recently with the advent of the so-called accelerator driven reactors (ADS proposed some time ago. The ADS systems, intended to be used either in energy generation or transuranium transmutation, will use a subcritical core with a strong spallation source. A spallation source has statistical properties that are different from those traditionally used by radioactive sources. In such reactors the monitoring of the subcritical reactivity is very important, and a statistical method, such as the Feynman-alpha method, is capable of resolving this problem.

  15. Thermonuclear Reflect AB-Reactor

    CERN Document Server

    Bolonkin, Alexander

    2008-01-01

    The author offers a new kind of thermonuclear reflect reactor. The remarkable feature of this new reactor is a three net AB reflector, which confines the high temperature plasma. The plasma loses part of its energy when it contacts with the net but this loss can be compensated by an additional permanent plasma heating. When the plasma is rarefied (has a small density), the heat flow to the AB reflector is not large and the temperature in the triple reflector net is lower than 2000 - 3000 K. This offered AB-reactor has significantly less power then the currently contemplated power reactors with magnetic or inertial confinement (hundreds-thousands of kW, not millions of kW). But it is enough for many vehicles and ships and particularly valuable for tunnelers, subs and space apparatus, where air to burn chemical fuel is at a premium or simply not available. The author has made a number of innovations in this reactor, researched its theory, developed methods of computation, made a sample computation of typical pr...

  16. Heterogeneous Transmutation Sodium Fast Reactor

    Energy Technology Data Exchange (ETDEWEB)

    S. E. Bays

    2007-09-01

    The threshold-fission (fertile) nature of Am-241 is used to destroy this minor actinide by capitalizing upon neutron capture instead of fission within a sodium fast reactor. This neutron-capture and its subsequent decay chain leads to the breeding of even neutron number plutonium isotopes. A slightly moderated target design is proposed for breeding plutonium in an axial blanket located above the active “fast reactor” driver fuel region. A parametric study on the core height and fuel pin diameter-to-pitch ratio is used to explore the reactor and fuel cycle aspects of this design. This study resulted in both non-flattened and flattened core geometries. Both of these designs demonstrated a high capacity for removing americium from the fuel cycle. A reactivity coefficient analysis revealed that this heterogeneous design will have comparable safety aspects to a homogeneous reactor of comparable size. A mass balance analysis revealed that the heterogeneous design may reduce the number of fast reactors needed to close the current once-through light water reactor fuel cycle.

  17. Entropy Production in Chemical Reactors

    Science.gov (United States)

    Kingston, Diego; Razzitte, Adrián C.

    2017-06-01

    We have analyzed entropy production in chemically reacting systems and extended previous results to the two limiting cases of ideal reactors, namely continuous stirred tank reactor (CSTR) and plug flow reactor (PFR). We have found upper and lower bounds for the entropy production in isothermal systems and given expressions for non-isothermal operation and analyzed the influence of pressure and temperature in entropy generation minimization in reactors with a fixed volume and production. We also give a graphical picture of entropy production in chemical reactions subject to constant volume, which allows us to easily assess different options. We show that by dividing a reactor into two smaller ones, operating at different temperatures, the entropy production is lowered, going as near as 48 % less in the case of a CSTR and PFR in series, and reaching 58 % with two CSTR. Finally, we study the optimal pressure and temperature for a single isothermal PFR, taking into account the irreversibility introduced by a compressor and a heat exchanger, decreasing the entropy generation by as much as 30 %.

  18. Simplifying Microbial Electrosynthesis Reactor Design

    Directory of Open Access Journals (Sweden)

    Cloelle G.S. Giddings

    2015-05-01

    Full Text Available Microbial electrosynthesis, an artificial form of photosynthesis, can efficiently convert carbon dioxide into organic commodities; however, this process has only previously been demonstrated in reactors that have features likely to be a barrier to scale-up. Therefore, the possibility of simplifying reactor design by both eliminating potentiostatic control of the cathode and removing the membrane separating the anode and cathode was investigated with biofilms of Sporomusa ovata, which reduces carbon dioxide to acetate. In traditional ‘H-cell’ reactors, where the anode and cathode chambers were separated with a proton-selective membrane, the rates and columbic efficiencies of microbial electrosynthesis remained high when electron delivery at the cathode was powered with a direct current power source rather than with a poteniostat-poised cathode utilized in previous studies. A membrane-less reactor with a direct-current power source with the cathode and anode positioned to avoid oxygen exposure at the cathode, retained high rates of acetate production as well as high columbic and energetic efficiencies. The finding that microbial electrosynthesis is feasible without a membrane separating the anode from the cathode, coupled with a direct current power source supplying the energy for electron delivery, is expected to greatly simplify future reactor design and lower construction costs.

  19. Hanford reactor and separations facility advantages

    Energy Technology Data Exchange (ETDEWEB)

    1963-06-27

    This document describes the advantages and limitations of Hanford production facilities. In addition to summarizing the technical parameters of the reactors and separations plants and their mechanical features, the unique aspects of these facilities to the production of special materials in which the Commission may be interested have been discussed. As the primary difference between the B-C-D-DR-F-H reactors and the K reactors and the K reactors is in the number and length of process channels. This report is addressed primarily to the 2000-tube reactors. K reactor characteristics are within the range of lattice and flexibility parameters described.

  20. Imaging Fukushima Daiichi reactors with muons

    Directory of Open Access Journals (Sweden)

    Haruo Miyadera

    2013-05-01

    Full Text Available A study of imaging the Fukushima Daiichi reactors with cosmic-ray muons to assess the damage to the reactors is presented. Muon scattering imaging has high sensitivity for detecting uranium fuel and debris even through thick concrete walls and a reactor pressure vessel. Technical demonstrations using a reactor mockup, detector radiation test at Fukushima Daiichi, and simulation studies have been carried out. These studies establish feasibility for the reactor imaging. A few months of measurement will reveal the spatial distribution of the reactor fuel. The muon scattering technique would be the best and probably the only way for Fukushima Daiichi to make this determination in the near future.

  1. Fast breeder reactors an engineering introduction

    CERN Document Server

    Judd, A M

    1981-01-01

    Fast Breeder Reactors: An Engineering Introduction is an introductory text to fast breeder reactors and covers topics ranging from reactor physics and design to engineering and safety considerations. Reactor fuels, coolant circuits, steam plants, and control systems are also discussed. This book is comprised of five chapters and opens with a brief summary of the history of fast reactors, with emphasis on international and the prospect of making accessible enormous reserves of energy. The next chapter deals with the physics of fast reactors and considers calculation methods, flux distribution,

  2. A tubular focused sonochemistry reactor

    Institute of Scientific and Technical Information of China (English)

    ZHOU GuangPing; LIANG ZhaoFeng; LI ZhengZhong; ZHANG YiHui

    2007-01-01

    This paper presents a new sonochemistry reactor, which consists of a cylindrical tube with a certain length and piezoelectric transducers at tube's end with the longitudinal vibration. The tube can effectively transform the longitudinal vibration into the radial vibration and thereby generates ultrasound. Furthermore, ultrasound can be focused to form high-intensity ultrasonic field inside tube. The reactor boasts of simple structure and its whole vessel wall can radiate ultrasound so that the electroacoustic transfer efficiency is high. The focused ultrasonic field provides good condition for sonochemical reaction. The length of the reactor can be up to 2 meters, and liquids can pass through it continuously, so it can be widely applied in liquid processing such as sonochemistry.

  3. A compact Tokamak transmutation reactor

    Institute of Scientific and Technical Information of China (English)

    QiuLi-Jian; XiaoBing-Jia

    1997-01-01

    The low aspect ration tokamak is proposed for the driver of a transmutation reactor.The main parameters of the reactor core,neutronic analysis of the blanket are given>the neutron wall loading can be lowered from the magnitude order of 1 MW/m2 to 0.5MW/m2 which is much easier to reach in the near future,and the transmutation efficiency (fission/absorption ratio)is raised further.The blanket power density is about 200MW/m3 which is not difficult to deal with.The key components such as diverter and center conductor post are also designed and compared with conventional TOkamak,Finally,by comparison with the other drivers such as FBR,PWR and accelerator,it can be anticipated that the low aspect ratio transmutation reactor would be one way of fusion energy applications in the near future.

  4. Plasma reactor waste management systems

    Science.gov (United States)

    Ness, Robert O., Jr.; Rindt, John R.; Ness, Sumitra R.

    1992-01-01

    The University of North Dakota is developing a plasma reactor system for use in closed-loop processing that includes biological, materials, manufacturing, and waste processing. Direct-current, high-frequency, or microwave discharges will be used to produce plasmas for the treatment of materials. The plasma reactors offer several advantages over other systems, including low operating temperatures, low operating pressures, mechanical simplicity, and relatively safe operation. Human fecal material, sunflowers, oats, soybeans, and plastic were oxidized in a batch plasma reactor. Over 98 percent of the organic material was converted to gaseous products. The solids were then analyzed and a large amount of water and acid-soluble materials were detected. These materials could possibly be used as nutrients for biological systems.

  5. Investigation of KW reactor incident

    Energy Technology Data Exchange (ETDEWEB)

    Sturges, D G [USAEC Hanford Operations Office, Richland, WA (United States); Hauff, T W; Greager, O H [General Electric Co., Richland, WA (United States). Hanford Atomic Products Operation

    1955-02-11

    The new KW reactor was placed in operation on January 4, 1955, and had been running at relatively low power levels for only 17 hours when it was shut down because of a process tube water leak which appeared to be associated with a slug rupture. After several days of unrewarding effort to remove the slugs and tube by customary methods, it developed that considerable melting of the tube and slugs had taken place. It was then evident that removal of the stuck mass and repairs to the damaged tube channel would require unusual measures that were certain to extend the reactor outage for several weeks. This report documents the work and findings of the Committee which investigated the KW reactor incident. Its content represents unanimous agreement among the three Committee members.

  6. Gaseous fuel nuclear reactor research

    Science.gov (United States)

    Schwenk, F. C.; Thom, K.

    1975-01-01

    Gaseous-fuel nuclear reactors are described; their distinguishing feature is the use of fissile fuels in a gaseous or plasma state, thereby breaking the barrier of temperature imposed by solid-fuel elements. This property creates a reactor heat source that may be able to heat the propellant of a rocket engine to 10,000 or 20,000 K. At this temperature level, gas-core reactors would provide the breakthrough in propulsion needed to open the entire solar system to manned and unmanned spacecraft. The possibility of fuel recycling makes possible efficiencies of up to 65% and nuclear safety at reduced cost, as well as high-thrust propulsion capabilities with specific impulse up to 5000 sec.

  7. Nuclear Reactor Engineering Analysis Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Carlos Chavez-Mercado; Jaime B. Morales-Sandoval; Benjamin E. Zayas-Perez

    1998-12-31

    The Nuclear Reactor Engineering Analysis Laboratory (NREAL) is a sophisticated computer system with state-of-the-art analytical tools and technology for analysis of light water reactors. Multiple application software tools can be activated to carry out different analyses and studies such as nuclear fuel reload evaluation, safety operation margin measurement, transient and severe accident analysis, nuclear reactor instability, operator training, normal and emergency procedures optimization, and human factors engineering studies. An advanced graphic interface, driven through touch-sensitive screens, provides the means to interact with specialized software and nuclear codes. The interface allows the visualization and control of all observable variables in a nuclear power plant (NPP), as well as a selected set of nonobservable or not directly controllable variables from conventional control panels.

  8. Utilisation of thorium in reactors

    Science.gov (United States)

    Anantharaman, K.; Shivakumar, V.; Saha, D.

    2008-12-01

    India's nuclear programme envisages a large-scale utilisation of thorium, as it has limited deposits of uranium but vast deposits of thorium. The large-scale utilisation of thorium requires the adoption of closed fuel cycle. The stable nature of thoria and the radiological issues associated with thoria poses challenges in the adoption of a closed fuel cycle. A thorium fuel based Advanced Heavy Water Reactor (AHWR) is being planned to provide impetus to development of technologies for the closed thorium fuel cycle. Thoria fuel has been loaded in Indian reactors and test irradiations have been carried out with (Th-Pu) MOX fuel. Irradiated thorium assemblies have been reprocessed and the separated 233U fuel has been used for test reactor KAMINI. The paper highlights the Indian experience with the use of thorium and brings out various issues associated with the thorium cycle.

  9. Utilización de Sistemas Basados en Reglas y en Casos para diseñar transmisiones por tornillo sinfín // Use of rules based systems and cases based systems for worm gear design

    Directory of Open Access Journals (Sweden)

    Jorge Laureano Moya‐Rodríguez

    2012-01-01

    Full Text Available Las técnicas de Inteligencia Artificial se aplican hoy en día a diferentes problemas de Ingeniería,especialmente los Sistemas Basados en el Conocimiento. Entre estos últimos los más comunes son losSistemas Basados en Patrones, los Sistemas Basados en Reglas, los Sistemas Basados en Casos y losSistemas Híbridos. Los Sistemas Basados en Casos parten de problemas resueltos en un dominio deaplicación y mediante un proceso de adaptación, encuentran la solución a un nuevo problema. Estossistemas pueden ser usados con éxito para el diseño de engranajes, particularmente para el diseño detransmisiones por tornillo sin fin, sin embargo ello constituye un campo de las aplicaciones de laInteligencia Artificial aún inexplorada. En el presente trabajo se hace una comparación del uso de losSistemas Basados en Regla y los Sistemas Basados en Casos para el diseño de transmisiones portornillo sin fin y se muestran los resultados de la aplicación de los sistemas basados en regla al diseñoparticular de una transmisión por tornillo sin fin.Palabras claves: tornillo sin fin, engranajes, sistemas basados en casos, sistemas basados en reglas,inteligencia artificial.____________________________________________________________________________AbstractNowadays Artificial Intelligence techniques are applied successfully to different engineering problems,especially the “Knowledge Based Systems”. Among them the most common are the “Frame basedSystems”, “Rules Based Systems”, “Case Based Systems” and "Hybrid Systems". The “Case BasedSystems” (CBS analyze solved problems in an application domain and by means of a process ofadaptation; they find the solution to a new problem. These systems can be used successfully for thedesign of gears, particularly for designing worm gears; nevertheless it constitutes a field of the applicationsof artificial intelligence even unexplored. A comparison of the use of “Rules Based System” and

  10. External fuel thermionic reactor system.

    Science.gov (United States)

    Mondt, J. F.; Peelgren, M. L.

    1971-01-01

    Thermionic reactors are prime candidates for nuclear electric propulsion. The national thermionic reactor effort is concentrated on the flashlight concept with the external-fuel concept as the backup. The external-fuel concept is very adaptable to a completely modular power subsystem which is attractive for highly reliable long-life applications. The 20- to 25-cm long, externally-fueled converters have been designed, fabricated, and successfully tested with many thermal cycles by electrical heating. However, difficulties have been encountered during encapsulation for nuclear heated tests and none have been started to date. These nuclear tests are required to demonstrate the concept feasibility.

  11. Analysis of Adiabatic Batch Reactor

    Directory of Open Access Journals (Sweden)

    Erald Gjonaj

    2016-05-01

    Full Text Available A mixture of acetic anhydride is reacted with excess water in an adiabatic batch reactor to form an exothermic reaction. The concentration of acetic anhydride and the temperature inside the adiabatic batch reactor are calculated with an initial temperature of 20°C, an initial temperature of 30°C, and with a cooling jacket maintaining the temperature at a constant of 20°C. The graphs of the three different scenarios show that the highest temperatures will cause the reaction to occur faster.

  12. PITR: Princeton Ignition Test Reactor

    Energy Technology Data Exchange (ETDEWEB)

    1978-12-01

    The principal objectives of the PITR - Princeton Ignition Test Reactor - are to demonstrate the attainment of thermonuclear ignition in deuterium-tritium, and to develop optimal start-up techniques for plasma heating and current induction, in order to determine the most favorable means of reducing the size and cost of tokamak power reactors. This report describes the status of the plasma and engineering design features of the PITR. The PITR geometry is chosen to provide the highest MHD-stable values of beta in a D-shaped plasma, as well as ease of access for remote handling and neutral-beam injection.

  13. Reactor shutdown delays medical procedures

    Science.gov (United States)

    Gwynne, Peter

    2008-01-01

    A longer-than-expected maintenance shutdown of the Canadian nuclear reactor that produces North America's entire supply of molybdenum-99 - from which the radioactive isotopes technetium-99 and iodine-131 are made - caused delays to the diagnosis and treatment of thousands of seriously ill patients last month. Technetium-99 is a key component of nuclear-medicine scans, while iodine-131 is used to treat cancer and other diseases of the thyroid. Production eventually resumed, but only after the Canadian government had overruled the Canadian Nuclear Safety Commission (CNSC), which was still concerned about the reactor's safety.

  14. Fundamentals of Nuclear Reactor Physics

    CERN Document Server

    Lewis, E E

    2008-01-01

    This new streamlined text offers a one-semester treatment of the essentials of how the fission nuclear reactor works, the various approaches to the design of reactors, and their safe and efficient operation. The book includes numerous worked-out examples and end-of-chapter questions to help reinforce the knowledge presented. This textbook offers an engineering-oriented introduction to nuclear physics, with a particular focus on how those physics are put to work in the service of generating nuclear-based power, particularly the importance of neutron reactions and neutron behavior. Engin

  15. Scaledown of a methanol reactor

    Energy Technology Data Exchange (ETDEWEB)

    Berty, J.M.

    1983-07-01

    This article shows how it is possible to define operating conditions for pilot plants and development labs by scaling down a commercial reactor. Points out that scaledown consideration and experiment planning can be done in a similar manner for the boiling water-cooled, Lurgi-type reactor. Explains that although the design of large, single-train plants to produce methanol for fuel use has different economic objectives, product specifications, and technical constraints from the traditional commercial methanol plants, the same fundamental laws of thermodynamics and reaction kinetics apply to both types of operation.

  16. Thermoelectric temperature control system for the pushbroom microwave radiometer (PBMR)

    Science.gov (United States)

    Dillon-Townes, L. A.; Averill, R. D.

    1984-06-01

    A closed loop thermoelectric temperature control system is developed for stabilizing sensitive RF integrated circuits within a microwave radiometer to an accuracy of + or - 0.1 C over a range of ambient conditions from -20 C to +45 C. The dual mode (heating and cooling) control concept utilizes partial thermal isolation of the RF units from an instrument deck which is thermally controlled by thermoelectric coolers and thin film heaters. The temperature control concept is simulated with a thermal analyzer program (MITAS) which consists of 37 nodes and 61 conductors. A full scale thermal mockup is tested in the laboratory at temperatures of 0 C, 21 C, and 45 C to confirm the validity of the control concept. A flight radiometer and temperature control system is successfully flight tested on the NASA Skyvan aircraft.

  17. Reactor Antineutrino Signals at Morton and Boulby

    CERN Document Server

    Dye, Steve

    2016-01-01

    Increasing the distance from which an antineutrino detector is capable of monitoring the operation of a registered reactor, or discovering a clandestine reactor, strengthens the Non-Proliferation of Nuclear Weapons Treaty. This report presents calculations of reactor antineutrino interactions, from quasi-elastic neutrino-proton scattering and elastic neutrino-electron scattering, in a water-based detector operated >10 km from a commercial power reactor. It separately calculates signal from the proximal reactor and background from all other registered reactors. The main results are interaction rates and kinetic energy distributions of charged leptons scattered from quasi-elastic and elastic processes. Comparing signal and background distributions evaluates reactor monitoring capability. Scaling the results to detectors of different sizes, target media, and standoff distances is straightforward. Calculations are for two examples of a commercial reactor (P_th~3 GW) operating nearby (L~20 km) an underground facil...

  18. Oregon State University TRIGA Reactor annual report

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, T.V.; Johnson, A.G.; Bennett, S.L.; Ringle, J.C.

    1979-08-31

    The use of the Oregon State University TRIGA Reactor during the year ending June 30, 1979, is summarized. Environmental and radiation protection data related to reactor operation and effluents are included.

  19. Request for Naval Reactors Comment on Proposed Prometheus Space Flight Nuclear Reactor High Tier Reactor Safety Requirements and for Naval Reactors Approval to Transmit These Requirements to JPL

    Energy Technology Data Exchange (ETDEWEB)

    D. Kokkinos

    2005-04-28

    The purpose of this letter is to request Naval Reactors comments on the nuclear reactor high tier requirements for the PROMETHEUS space flight reactor design, pre-launch operations, launch, ascent, operation, and disposal, and to request Naval Reactors approval to transmit these requirements to Jet Propulsion Laboratory to ensure consistency between the reactor safety requirements and the spacecraft safety requirements. The proposed PROMETHEUS nuclear reactor high tier safety requirements are consistent with the long standing safety culture of the Naval Reactors Program and its commitment to protecting the health and safety of the public and the environment. In addition, the philosophy on which these requirements are based is consistent with the Nuclear Safety Policy Working Group recommendations on space nuclear propulsion safety (Reference 1), DOE Nuclear Safety Criteria and Specifications for Space Nuclear Reactors (Reference 2), the Nuclear Space Power Safety and Facility Guidelines Study of the Applied Physics Laboratory.

  20. Tratamientos basados en la evidencia para adolescentes con trastornos por consumo de cannabis en el Sistema Público de Salud

    Directory of Open Access Journals (Sweden)

    Sergio Fernández Artamendi

    2014-01-01

    Full Text Available El objetivo de este estudio era describir la implementación de dos programas basados en la evidencia (PBE para adolescentes con trastornos por consumo de cannabis en el Sistema Público de Salud, y sus principales resultados. La Aproximación de Reforzamiento Comunitario para Adolescentes (A-CRA y el Control de Contingencias (MC fueron elegidos como los programas de intervención más eficaces para esta población. Un total de 26 adolescentes participaron en el estudio (91,7% chicos; edad media = 16,5 años en dos centros de carácter ambulatorio en España. Se utilizó un diseño cuasi-experimental, donde un grupo recibió A-CRA y el otro A-CRA+MC. La implementación de ambos programas resultó factible, con resultados clínicos positivos. El A-CRA ofreció buenas tasas de retención (81,3% y abstinencia (68,6%. Los resultados del grupo A-CRA+MC no fueron significativamente mejores que los del A-CRA en retención (100% o abstinencia (75,5%, aunque el limitado tamaño muestral no permite establecer conclusiones firmes. Los problemas asociados al cannabis y la sintomatología depresiva se redujeron durante el tratamiento. Varias limitaciones nos impiden determinar la eficacia clínica del A-CRA en este estudio. El proceso de traslación de los PBE al contexto clínico presentó múltiples dificultades que deben ser abordadas. Se discuten recomendaciones para futuros intentos de implementación de PBE en estos contextos.

  1. Sistema de información documental sobre desplazamiento forzado en Colombia basado en ontologías

    Directory of Open Access Journals (Sweden)

    Sandra Patricia Arenas Grisales

    2009-01-01

    Full Text Available Presenta el proceso de elaboración del Sistema de información documental sobre desplazamientoforzado en Colombia basado en ontologías. La investigación se planteó como objetivo general construiruna ontología que representa conceptualmente la terminología sobre el desplazamiento forzadoen Colombia, de manera que permita representar y recuperar la información referencial y en textocompleto de la documentación producida. Presenta una breve descripción de lo que son las ontologíasy su aplicación para la gestión y recuperación de información. En la construcción de la ontología hubotres momentos, en cada uno de los cuales se integraron y adaptaron diferentes metodologías propuestasdesde la terminología, la documentación y la ingeniería informática. Para la creación del árbol dedominio, la confección del tesauro y la estructuración de las relaciones jerárquicas se implementó lametodología propia de la terminología; en la creación de la ontología las metodologías propuestas porNoy y Macguines y la Universidad Politécnica de Madrid para la estructuración de ontologías y, laaplicación de diferentes lenguajes y herramientas informáticas. Finalmente se describe el sistema deinformación documental y la interfaz de consulta.

  2. Cinemática inversa de robot serial utilizando algoritmo genético basado en MCDS

    Directory of Open Access Journals (Sweden)

    Juan Jairo Vaca González

    2015-04-01

    Full Text Available Los robots manipuladores seriales son herramientas eficaces para realizar tareas repetitivas y de precisión en la industria, siempre que se comprenda la cinemática involucrada en el posicionamiento y orientación del efector final. Este artículo presenta una metodología para resolver el problema cinemático inverso de un robot serial (Melfa RV-2A utilizando un algoritmo genético (AG a partir del modelo cinemático directo Screws (MCDS. Para esto, se obtienen los parámetros Screw que modelan el robot, se calcula el espacio de trabajo asociado y se diseña el AG contemplando una función multi-objetivo de alcance de posición y orientación en que se sitúa el efector final, con respecto a una coordenada y orientación de un punto objetivo establecido. La validación del AG se realiza según la aptitud, el tiempo de convergencia y la cantidad de generaciones usadas por la función para alcanzar el objetivo. Por tanto, la implementación de un AG basado en un MCDS es una herramienta prometedora que podría utilizarse para calcular la cinemática inversa de robots seriales. Esta novedosa implementación permite establecer por primera vez la exposición matricial de un sistema cinemático directo para obtener la solución cinemática inversa de un robot serial. En consecuencia, se demuestra que esta es una metodología factible y eficiente para solucionar la cinemática inversa de cualquier tipo de robot manipulador.

  3. Sistema experto basado en lógica difusa tipo 1 para determinar el grado de riesgo de preeclampsia

    Directory of Open Access Journals (Sweden)

    Edna Rocio Núñez Flórez

    2014-01-01

    Full Text Available La preeclampsia es una enfermedad que pueden desarrollar las mujeres en estado de embarazo, y según el DANE es responsable del 35 % de las muertes maternas en Colombia. Ante esta situación, el objetivo de este artículo es presentar un sistema experto (SE basado en lógica difusa tipo I que permite identificar el nivel de riesgo de sufrir la enfermedad, y posibilita un diagnóstico precoz y la vigilancia estricta de la mujer gestante, aspectos fundamentales para prevenir las complicaciones asociadas a la preeclampsia. Para llevar a cabo la investigación se realizó la revisión bibliográfica para conocer los factores de riesgo que generan la enfermedad; con apoyo de un médico se establecieron los factores que se deben tener en cuenta (variables de entrada y la base de reglas, los cuales son los componentes principales del SE. Posteriormente se realiza la implementación del software con las herramientas MySql como base de datos y Java como lenguaje de programación. Para la validación de tomaron 30 historias clínicas suministradas por la Secretaría de Salud Departamental del Caquetá. El resultado del SE arrojó un 94.17 % de efectividad con un margen de error del 5.83 %, comparados con los resultados proporcionados por el especialista que analizó las historias clínicas.

  4. El aprendizaje basado en problemas como enfoque pedagógico en la educación en salud.

    Directory of Open Access Journals (Sweden)

    Víctor Hugo Dueñas

    2009-11-01

    Full Text Available Para asegurar la competencia y la calidad en la práctica profesional, la universidad a través de los procesos formativos debe proponer actividades que además de estimular la ejercitación repetida, desarrollen los procesos de pensamiento crítico. El pensamiento crítico se puede ilustrar como una habilidad adquirible que demanda competencias para evaluar, intuir, debatir, sustentar, opinar, decidir y discutir, entre otras. Estas competencias se pueden desarrollar -por lo menos en parte- en los espacios destinados a la socialización del conocimiento que se ofrecen en el enfoque de aprendizaje basado en problemas (ABP. El ABP es un enfoque pedagógico multi-metodológico y multi-didáctico, encaminado a facilitar el proceso de enseñanza-aprendizaje y de formación del estudiante. En este enfoque se privilegia el auto-aprendizaje y la auto-formación, procesos que son facilitados por la dinámica del enfoque y la concepción constructivista ecléctica del mismo. En el enfoque de ABP se fomenta la autonomía cognoscitiva, se enseña y se aprende a partir de problemas que tienen significado para los estudiantes, se utiliza el error como una oportunidad más para aprender y no para castigar y se le otorga un valor importante a la auto-evaluación y a la evaluación formativa, cualitativa e individualizada.

  5. El aprendizaje basado en problemas y su utilidad en el desarrollo curricular en las ciencias de la salud

    Directory of Open Access Journals (Sweden)

    Omar Santiago Ramírez-Montes

    2015-04-01

    Full Text Available ¿Qué enseñar? ¿Cuándo enseñar? ¿Cómo enseñar? ¿Qué, cómo y cuándo evaluar? Son preguntas que deben tener una reevaluación permanente. El aprendizaje basado en problemas (ABP es una herramienta metodológica que puede implementarse en los currículos de las áreas de la salud con el fin de que en las aulas se haga ciencia. Este aprendizaje también promueve un contexto de interdisciplinariedad y cuestiona la idea tradicional de que el conocimiento está dentro de marcos conceptuales totalmente acabados, los cuales no son susceptibles de transformarse en la práctica para bien de estudiantes y pacientes. Se debe anotar que el ABP requiere de infraestructuras y modelos pedagógicos diferentes-comenzando por la formación de los propios tutores-y, por ello, se pueden implementar estrategias para que, si bien no sea un recurso exclusivo de formación profesional, surja como alternativa en algunos de los componentes de fundamentación o profesionalización de los programas de la salud. Enseñar para la comprensión, alentar la intersubjetividad y aprender a aprender son acciones que forman parte de este proceso constructivista enseñanza-aprendizaje, en el que el protagonista debe ser el estudiante. Para ello hay que innovar de tal manera que este adquiera un compromiso para toda la vida y se convierta en un generador o constructor de conocimiento dentro del contexto social de la salud, con autonomía y autorregulación.

  6. APRENDIZAJE BASADO EN PROBLEMAS PARA DESARROLLAR ALFABETIZACIÓN CRÍTICA Y COMPETENCIAS CIUDADANAS EN EL NIVEL ELEMENTAL

    Directory of Open Access Journals (Sweden)

    Aura González Robles

    2016-01-01

    Full Text Available Este artículo presenta los hallazgos de una investigación-acción que se realizó en el tercer grado de una escuela pública en Puerto Rico en un curso que integra las disciplinas de Artes del Lenguaje, Ciencias y Estudios Sociales. Este estudio cualitativo exploró en qué medida el Aprendizaje Basado en Problemas (ABP facilita el desarrollo de la alfabetización crítica y las competencias ciudadanas. Las técnicas de recopilación de información consistieron en observaciones participativas y no-participativas, notas de campo, fotografías y materiales que desarrollaron los estudiantes. Teóricamente, este trabajo se fundamenta en el constructivismo social, en particular las ideas de Paulo Freire, así como en los conceptos de competencias ciudadanas y alfabetización ciudadana como fundamentos para el desarrollo humano integral. El análisis de los datos permite concluir que el ABP fomenta, a través de sus distintos pasos, el desarrollo inicial de los atributos de la alfabetización crítica y las competencias ciudadanas de las niñas y los niños de tercer grado. De acuerdo con los hallazgos se observó que el atributo de recursos personales y culturales, correspondiente a la competencia de alfabetización crítica se propició en todos los pasos de ABP. Asimismo, el atributo más frecuente relacionado a las competencias ciudadanas fue la capacidad de inquirir.

  7. Transmutation of actinides in power reactors.

    Science.gov (United States)

    Bergelson, B R; Gerasimov, A S; Tikhomirov, G V

    2005-01-01

    Power reactors can be used for partial short-term transmutation of radwaste. This transmutation is beneficial in terms of subsequent storage conditions for spent fuel in long-term storage facilities. CANDU-type reactors can transmute the main minor actinides from two or three reactors of the VVER-1000 type. A VVER-1000-type reactor can operate in a self-service mode with transmutation of its own actinides.

  8. Heavy Water Reactor; Reacteurs a eau lourde

    Energy Technology Data Exchange (ETDEWEB)

    Yu, St.; HOpwood, J.; Meneley, D. [Energie Atomique du Canada (Canada)

    2000-04-01

    This document deals with the Heavy Water Reactor (HWR) technology and especially the Candu (Canada Deuterium Uranium) reactor. This reactors type offers many advantages that promote them for the future. General concepts, a description of the Candu nuclear power plants, the safety systems, the fuel cycle and economical and environmental aspects are included. (A.L.B.)

  9. Heat-pipe thermionic reactor concept

    DEFF Research Database (Denmark)

    Storm Pedersen, E.

    1967-01-01

    Main components are reactor core, heat pipe, thermionic converter, secondary cooling system, and waste heat radiator; thermal power generated in reactor core is transported by heat pipes to thermionic converters located outside reactor core behind radiation shield; thermionic emitters are in direct...

  10. Some new viewpoints in reactor noise analysis

    Institute of Scientific and Technical Information of China (English)

    罗征培; 李富; 等

    1996-01-01

    It is propsed that the linearity criterion and order criterion via frequency spectrum features without any limitation of the model's phase can be used in reactor noise analysis.The time constant,natural frequency as well as the recovered transfer function of reactors can bhe obtained via the analyzable model based on reactor noise.

  11. Operating Modes Of Chemical Reactors Of Polymerization

    Directory of Open Access Journals (Sweden)

    Meruyert Berdieva

    2012-05-01

    Full Text Available In the work the issues of stable technological modes of operation of main devices of producing polysterol reactors have been researched as well as modes of stable operation of a chemical reactor have been presented, which enables to create optimum mode parameters of polymerization process, to prevent emergency situations of chemical reactor operation in industrial conditions.

  12. Laminar Entrained Flow Reactor (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    2014-02-01

    The Laminar Entrained Flow Reactor (LEFR) is a modular, lab scale, single-user reactor for the study of catalytic fast pyrolysis (CFP). This system can be employed to study a variety of reactor conditions for both in situ and ex situ CFP.

  13. Silica-Immobilized Enzyme Reactors

    Science.gov (United States)

    2007-08-01

    immobilized artificial membrane chromatography and lysophospholipid micellar electrokinetic chromatography . J. Chromatogr. A 1998, 810, 95-103. 50...Journal of Liquid Chromatography and Related Technologies. Air Force Research Laboratory Materials and Manufacturing Directorate Airbase...immobilized enzyme reactors (IMERs) can also be integrated directly to further analytical methods such as liquid chromatography or mass spectrometry.[6] In

  14. Nozzle for electric dispersion reactor

    Science.gov (United States)

    Sisson, Warren G.; Basaran, Osman A.; Harris, Michael T.

    1995-01-01

    A nozzle for an electric dispersion reactor includes two concentric electrodes, the inner one of the two delivering disperse phase fluid into a continuous phase fluid. A potential difference generated by a voltage source creates a dispersing electric field at the end of the inner electrode.

  15. A Simple Tubular Reactor Experiment.

    Science.gov (United States)

    Hudgins, Robert R.; Cayrol, Bertrand

    1981-01-01

    Using the hydrolysis of crystal violet dye by sodium hydroxide as an example, the theory, apparatus, and procedure for a laboratory demonstration of tubular reactor behavior are described. The reaction presented can occur at room temperature and features a color change to reinforce measured results. (WB)

  16. High temperature catalytic membrane reactors

    Energy Technology Data Exchange (ETDEWEB)

    1990-03-01

    Current state-of-the-art inorganic oxide membranes offer the potential of being modified to yield catalytic properties. The resulting modules may be configured to simultaneously induce catalytic reactions with product concentration and separation in a single processing step. Processes utilizing such catalytically active membrane reactors have the potential for dramatically increasing yield reactions which are currently limited by either thermodynamic equilibria, product inhibition, or kinetic selectivity. Examples of commercial interest include hydrogenation, dehydrogenation, partial and selective oxidation, hydrations, hydrocarbon cracking, olefin metathesis, hydroformylation, and olefin polymerization. A large portion of the most significant reactions fall into the category of high temperature, gas phase chemical and petrochemical processes. Microporous oxide membranes are well suited for these applications. A program is proposed to investigate selected model reactions of commercial interest (i.e. dehydrogenation of ethylbenzene to styrene and dehydrogenation of butane to butadiene) using a high temperature catalytic membrane reactor. Membranes will be developed, reaction dynamics characterized, and production processes developed, culminating in laboratory-scale demonstration of technical and economic feasibility. As a result, the anticipated increased yield per reactor pass economic incentives are envisioned. First, a large decrease in the temperature required to obtain high yield should be possible because of the reduced driving force requirement. Significantly higher conversion per pass implies a reduced recycle ratio, as well as reduced reactor size. Both factors result in reduced capital costs, as well as savings in cost of reactants and energy.

  17. Nuclear Reactors and Technology; (USA)

    Energy Technology Data Exchange (ETDEWEB)

    Cason, D.L.; Hicks, S.C. (eds.)

    1991-01-01

    Nuclear Reactors and Technology (NRT) announces on a monthly basis the current worldwide information available from the open literature on nuclear reactors and technology, including all aspects of power reactors, components and accessories, fuel elements, control systems, and materials. This publication contains the abstracts of DOE reports, journal articles, conference papers, patents, theses, and monographs added to the Energy Science and Technology Database (EDB) during the past month. Also included are US information obtained through acquisition programs or interagency agreements and international information obtained through the International Energy Agency's Energy Technology Data Exchange or government-to-government agreements. The digests in NRT and other citations to information on nuclear reactors back to 1948 are available for online searching and retrieval on EDB and Nuclear Science Abstracts (NSA) database. Current information, added daily to EDB, is available to DOE and its contractors through the DOE integrated Technical Information System. Customized profiles can be developed to provide current information to meet each user's needs.

  18. British high flux beam reactor.

    Science.gov (United States)

    Egelstaff, P A

    1970-10-24

    The neutron scattering technique has become an accepted method for the study of condensed matter. Because of the great scientific and technical value of neutron experiments and the growing body of users, several proposals have been made during the past decade for a nuclear reactor devoted primarily to this technique. This article reviews the reasons for and history behind these proposals.

  19. Nuclear reactors and fuel cycle

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2014-07-01

    The Nuclear Fuel Center (CCN) of IPEN produces nuclear fuel for the continuous operation of the IEA-R1 research reactor of IPEN. The serial production started in 1988, when the first nuclear fuel element was delivered for IEA-R1. In 2011, CCN proudly presents the 100{sup th} nuclear fuel element produced. Besides routine production, development of new technologies is also a permanent concern at CCN. In 2005, U{sub 3}O{sub 8} were replaced by U{sub 3}Si{sub 2}-based fuels, and the research of U Mo is currently under investigation. Additionally, the Brazilian Multipurpose Research Reactor (RMB), whose project will rely on the CCN for supplying fuel and uranium targets. Evolving from an annual production from 10 to 70 nuclear fuel elements, plus a thousand uranium targets, is a huge and challenging task. To accomplish it, a new and modern Nuclear Fuel Factory is being concluded, and it will provide not only structure for scaling up, but also a safer and greener production. The Nuclear Engineering Center has shown, along several years, expertise in the field of nuclear, energy systems and correlated areas. Due to the experience obtained during decades in research and technological development at Brazilian Nuclear Program, personnel has been trained and started to actively participate in design of the main system that will compose the Brazilian Multipurpose Reactor (RMB) which will make Brazil self-sufficient in production of radiopharmaceuticals. The institution has participated in the monitoring and technical support concerning the safety, licensing and modernization of the research reactors IPEN/MB-01 and IEA-R1. Along the last two decades, numerous specialized services of engineering for the Brazilian nuclear power plants Angra 1 and Angra 2 have been carried out. The contribution in service, research, training, and teaching in addition to the development of many related technologies applied to nuclear engineering and correlated areas enable the institution to

  20. A new MTR fuel for a new MTR reactor: UMo for the Jules Horowitz reactor

    Energy Technology Data Exchange (ETDEWEB)

    Guigon, B. [CEA Cadarache, F-13108 Saint Paul lez Durance (France); Vacelet, H. [CERCA, Romans (France); Dornbusch, D. [Technicatome, Aix en Provence (France)

    2000-07-01

    Within some years, the Jules Horowitz Reactor will be the only working experimental reactor (material and fuel testing reactor) in France. It will have to provide facilities for a wide range of needs from activation analysis to power reactor fuel qualification. In this paper the main characteristics of the Jules Horowitz Reactor are presented. Safety criteria are explained. Finally, merits and disadvantages of UMo compared to the standard U{sub 3}Si{sub 2} fuel are discussed. (author)

  1. Heterogeneous Recycling in Fast Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Forget, Benoit; Pope, Michael; Piet, Steven J.; Driscoll, Michael

    2012-07-30

    Current sodium fast reactor (SFR) designs have avoided the use of depleted uranium blankets over concerns of creating weapons grade plutonium. While reducing proliferation risks, this restrains the reactor design space considerably. This project will analyze various blanket and transmutation target configurations that could broaden the design space while still addressing the non-proliferation issues. The blanket designs will be assessed based on the transmutation efficiency of key minor actinide (MA) isotopes and also on mitigation of associated proliferation risks. This study will also evaluate SFR core performance under different scenarios in which depleted uranium blankets are modified to include minor actinides with or without moderators (e.g. BeO, MgO, B4C, and hydrides). This will be done in an effort to increase the sustainability of the reactor and increase its power density while still offering a proliferation resistant design with the capability of burning MA waste produced from light water reactors (LWRs). Researchers will also analyze the use of recycled (as opposed to depleted) uranium in the blankets. The various designs will compare MA transmutation efficiency, plutonium breeding characteristics, proliferation risk, shutdown margins and reactivity coefficients with a current reference sodium fast reactor design employing homogeneous recycling. The team will also evaluate the out-of-core accumulation and/or burn-down rates of MAs and plutonium isotopes on a cycle-by-cycle basis. This cycle-by-cycle information will be produced in a format readily usable by the fuel cycle systems analysis code, VISION, for assessment of the sustainability of the deployment scenarios.

  2. Reactor monitoring and safeguards using antineutrino detectors

    CERN Document Server

    Bowden, N S

    2008-01-01

    Nuclear reactors have served as the antineutrino source for many fundamental physics experiments. The techniques developed by these experiments make it possible to use these very weakly interacting particles for a practical purpose. The large flux of antineutrinos that leaves a reactor carries information about two quantities of interest for safeguards: the reactor power and fissile inventory. Measurements made with antineutrino detectors could therefore offer an alternative means for verifying the power history and fissile inventory of a reactors, as part of International Atomic Energy Agency (IAEA) and other reactor safeguards regimes. Several efforts to develop this monitoring technique are underway across the globe.

  3. Neutrino Mixing Discriminates Geo-reactor Models

    CERN Document Server

    Dye, S T

    2009-01-01

    Geo-reactor models suggest the existence of natural nuclear reactors at different deep-earth locations with loosely defined output power. Reactor fission products undergo beta decay with the emission of electron antineutrinos, which routinely escape the earth. Neutrino mixing distorts the energy spectrum of the electron antineutrinos. Characteristics of the distorted spectrum observed at the earth's surface could specify the location of a geo-reactor, discriminating the models and facilitating more precise power measurement. The existence of a geo-reactor with known position could enable a precision measurement of the neutrino oscillation parameter delta-mass-squared.

  4. Reactor assessments of advanced bumpy torus configurations

    Energy Technology Data Exchange (ETDEWEB)

    Uckan, N.A.; Owen, L.W.; Spong, D.A.; Miller, R.L.; Ard, W.B.; Pipkins, J.F.; Schmitt, R.J.

    1983-01-01

    Recently, several configurational approaches and concept improvement schemes were introduced for enhancing the performance of the basic ELMO Bumpy Torus (EBT) concept and for improving its reactor potential. These configurations include planar racetrack and square geometries, Andreoletti coil systems, and bumpy torus-stellarator hybrids (which include twisted racetrack and helical axis stellarator-snakey torus). Preliminary evaluations of reactor implications of each of these configurations have been carried out based on magnetics (vacuum) calculations, transport and scaling relationships, and stability properties. Results indicate favorable reactor projections with a significant reduction in reactor physical size as compared to conventional EBT reactor designs carried out in the past.

  5. Refurbishment of existing research reactors for BNCT

    Energy Technology Data Exchange (ETDEWEB)

    Jatuff, F.E.; Gessaghi, V. [INVAP S.E., de Bariloche (Argentina)

    1997-12-01

    Some research reactors have been selected for the development of boron neutron capture therapy (BNCT) in the United States like the Massachusetts Institute of Technology research reactor, the University of Missouri research reactor 2 or the Brookhaven Medical Research Reactor, among others. These reactors have received excellent analyses and designs to accommodate extremely optimized beam shaping assemblies (BSAs) for the proper tuning of neutron spectra and absorption of undesired particles such as photons and fast neutrons. Due to the importance of BNCT in these facilities, the physicists and engineers have used many degrees of freedom for the optimization process.

  6. Tandem Mirror Reactor Systems Code (Version I)

    Energy Technology Data Exchange (ETDEWEB)

    Reid, R.L.; Finn, P.A.; Gohar, M.Y.; Barrett, R.J.; Gorker, G.E.; Spampinaton, P.T.; Bulmer, R.H.; Dorn, D.W.; Perkins, L.J.; Ghose, S.

    1985-09-01

    A computer code was developed to model a Tandem Mirror Reactor. Ths is the first Tandem Mirror Reactor model to couple, in detail, the highly linked physics, magnetics, and neutronic analysis into a single code. This report describes the code architecture, provides a summary description of the modules comprising the code, and includes an example execution of the Tandem Mirror Reactor Systems Code. Results from this code for two sensitivity studies are also included. These studies are: (1) to determine the impact of center cell plasma radius, length, and ion temperature on reactor cost and performance at constant fusion power; and (2) to determine the impact of reactor power level on cost.

  7. Savannah River Site production reactor technical specifications. K Production Reactor

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-02-01

    These technical specifications are explicit restrictions on the operation of the Savannah River Site K Production Reactor. They are designed to preserve the validity of the plant safety analysis by ensuring that the plant is operated within the required conditions bounded by the analysis, and with the operable equipment that is assumed to mitigate the consequences of an accident. Technical specifications preserve the primary success path relied upon to detect and respond to accidents. This report describes requirements on thermal-hydraulic limits; limiting conditions for operation and surveillance for the reactor, power distribution control, instrumentation, process water system, emergency cooling and emergency shutdown systems, confinement systems, plant systems, electrical systems, components handling, and special test exceptions; design features; and administrative controls.

  8. Modelos basados en agentes: aportes epistemológicos y teóricos para la investigación social

    Directory of Open Access Journals (Sweden)

    Leonardo Gabriel Rodríguez Zoya

    2015-01-01

    Full Text Available Los modelos basados en agentes (MBA constituyen una nueva generación de métodos computacionales que permiten modelar la estructura de un sistema complejo y simular su evolución dinámica a lo largo deI tiempo. EI uso de los MBA constituye una tendencia metodológica en expansión en las ciencias sociales contemporáneas; sin embargo, continúan siendo poco conocidos y enseiíados en el campo sociológico, de modo que constituyen una alternativa metodológica minoritaria entre los investigadores sociales. EI propósito de este trabajo es introducir a los científicos sociales en las ideas centrales de los modelos basados en agentes a partir de su articulación con ciertos problemas teóricos y metodológicos cruciales de las ciencias sociales. La primera sección problematiza la relación entre los modelos basados en agentes y los sistemas complejos en una perspectiva epistemológica crítica. Posteriormente, se analizan los aportes de los MBA a la investigación social, y en la tercera sección se evalúa críticamente su aplicación en el marco de una disciplina particular: la ciencia política. Finalmente, se desarrolla un ejemplo práctico de una simulación basada en agentes a partir del trabajo clásico de Thomas Schelling sobre segregación racial.

  9. Efecto de un programa de entrenamiento físico basado en la secuencia de desarrollo sobre el balance postural en futbolistas: ensayo controlado aleatorizado

    Directory of Open Access Journals (Sweden)

    Erica Mancera-Soto

    2013-12-01

    Full Text Available Antecedentes. En la actividad deportiva, el balance postural es requerido para mantener la estabilidad durante el juego. Por tanto, existe una necesidad de determinar si el aprendizaje motor desde posiciones funcionales, movimientos coordinados están implicados en los deportes. Objetivo. El objetivo de este estudio fue determinar el efecto de un entrenamiento físico basado en la secuencia de desarrollo sobre el balance postural en futbolistas de la selección de la Universidad Nacional de Colombia, sede Bogotá. Materiales y métodos. Ensayo controlado aleatorizado de 19 hombres adultos jóvenes pertenecientes al equipo de futbol de la Universidad Nacional de Colombia, sede Bogotá. Los participantes fueron aleatorizados y asignados a dos grupos, un grupo intervención (n=11, en el cual se le aplicó un entrenamiento físico basado en la secuencia de desarrollo y un grupo control (n=8 el cual realizó un programa de entrenamiento convencional de futbol. Resultados. Existe homogeneidad entre los dos grupos, en el test de balance dinámico SEBT los valores obtenidos (P<0,5, demuestran una mejoría en todas las direcciones evaluadas tanto en el miembro inferior derecho como en el izquierdo. En el grupo de intervención, la relación intragrupal muestra una correlación 3:1 siendo una medida de protección. Conclusión. La aplicación de un programa de entrenamiento físico basado en la secuencia de desarrollo genera importantes mejoras en el balance estático y dinámico. Se demuestran mejoras en las distancias de excursión lo cual se puede relacionar con un aumento del control postural dinámico.

  10. CFD Simulation on Ethylene Furnace Reactor Tubes

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Different mathematical models for ethylene furnace reactor tubes were reviewed. On the basis of these models a new mathematical simulation approach for reactor tubes based on computational fluid dynamics (CFD) technique was presented. This approach took the flow, heat transfer, mass transfer and thermal cracking reactions in the reactor tubes into consideration. The coupled reactor model was solved with the SIMPLE algorithm. Some detailed information about the flow field, temperature field and concentration distribution in the reactor tubes was obtained, revealing the basic characteristics of the hydrodynamic phenomena and reaction behavior in the reactor tubes. The CFD approach provides the necessary information for conclusive decisions regarding the production optimization, the design and improvement of reactor tubes, and the new techniques implementation.

  11. Análisis bibliométrico de la Revista Mexicana de Sociología basado en indicadores de citación

    OpenAIRE

    2015-01-01

    Este trabajo tiene por objeto presen - tar de manera gráfica y sintética estadísticas e indicadores que permiten cuantificar el uso y el impacto de la Revista Mexicana de Socio - logía ( RMS ). Para tal efecto, se presentan las estadísticas de consulta por parte de los lectores de la versión electrónica de la revista disponible en la Colección SciELO-México y se enfatiza, en particular, en los datos e indicadores basados en la citación (citas recibidas) reportados por tres bases bib...

  12. Modelado y control basado en redes neuronales artificiales de una planta piloto de desalinización de agua de mar de ósmosis inversa

    OpenAIRE

    Carrasco Banda, Neil Neizer

    2016-01-01

    En este trabajo de tesis se parte de la hipótesis de que: es posible aumentar la eficiencia de las plantas desalinizadoras de agua de mar utilizando sistemas de control inteligente, conformados por controladores multivariables fundamentados en redes neuronales artificiales y modelos matemáticos multivariables basados en las leyes de conservación de la materia y energía. Se empieza describiendo las tecnologías empleadas a nivel industrial para la desalinización de agua, y se continúa con un...

  13. OASEARCH: Modelo de aplicación basado en web semántica para la búsqueda de objetos de aprendizaje mediante perfilado de consultas

    OpenAIRE

    Gómez Álvarez, Diego Fernando

    2014-01-01

    Uno de los aspectos que determina la calidad de un Sistema Educativo Basado en la Web es la manera en que este proporciona a los estudiantes los objetos de aprendizaje que mejor se adaptan a sus condiciones específicas -- Es por lo anterior que se hace necesario contar con mecanismos de búsqueda para estos objetos que puedan ser usados fácilmente por la aplicación o por los usuarios de la misma y que entreguen los resultados más relevantes posibles en un contexto determinado -- Múltiples meca...

  14. La interdisciplinariedad en el aprendizaje basado en problemas en las enseñanzas jurídicas: La necesidad de coordinación entre materias

    OpenAIRE

    Olmedo Peralta, Eugenio

    2011-01-01

    Producción Científica En el marco del Espacio Europeo de Educación Superior, la metodología a seguir en la enseñanza de disciplinas jurídicas debe fomentar la participación del alumno en su propio proceso de aprendizaje, mecanismo imprescindible para formar profesionales autónomos. Emplear técnicas docentes tales como la programación del aprendizaje basado en problemas o la construcción práctica de supuestos presenta las ventajas de conseguir captar el interés del alumno y ...

  15. Colgajo de pectoral mayor basado en perforantes internas inferiores: Doble plano invertido Pectoral muscle flap based on inferior-internal perforators: Inverted dual plane

    OpenAIRE

    V. O. Vassaro; A. H. Ali; D. M. Capponi

    2010-01-01

    El polo inferior de la mama en ocasiones puede estar afectado en su espesor por diferentes causas, como el simple paso del tiempo, resecciones oncológicas, extrusiones protésicas por infección, seromas, fístulas, etc. Describimos en este trabajo una alternativa quirúrgica para brindar una mayor cobertura al cuadrante ínferointerno de la glándula mamaria, utilizando un colgajo de músculo pectoral en su porción distal, basado en la irrigación de sus perforantes internas.Some times, the mammary ...

  16. Estructuración de códigos geotécnicos basados en el modelo de estados límite de diseño

    Directory of Open Access Journals (Sweden)

    Nayib Moreno

    2012-01-01

    Full Text Available En este artículo se ofrecen los principios de diseño y las reglas de aplicación propuestas para que sean consideradas en las revisiones de la Norma Sismo Resistente 2010 (NSR-10 y en el Código de Laderas del Distrito de Barranquilla, basados adecuadamente en el modelo de estados límite de diseño, donde a partir de principios de diseño asociados a reglas de aplicación determinísticas o probabilísticas, se pudiese dimensionar racionalmente las cimentaciones con niveles de seguridad apropiados.

  17. Empleo de aprendizaje basado en juegos y técnicas de gamificación en el ámbito universitario

    OpenAIRE

    Vera, Pablo Martín; Moreno, Edgardo J.; Rodríguez, Rocío Andrea; Narmona, Alejandro; Vázquez, M. Carina; Dogliotti, Mariano

    2015-01-01

    El aprendizaje basado en juegos puede ser utilizado también en el ámbito académico universitario, teniendo como enfoque principal la motivación de los alumnos. Pero también implica analizar cómo presentar los contenidos para que los alumnos puedan evaluar sus conocimientos por fuera del espacio del aula física. Por otra parte el concepto de gamificación plantea utilizar técnicas de juegos en ámbitos no lúdicos, lo que implica analizar mecanismos de implementación de desafíos, premios, niveles...

  18. Inclusión en Weka de filtros basados en conjuntos aproximados para bases desbalanceadas (Inclusion of filters in Weka based in rough sets for imbalanced bases)

    OpenAIRE

    Addel Arnaldo Goya Jorge; Deborah Galpert Cañizares; Felipe Antonio Enríquez Rodríguez

    2015-01-01

    Spanish abstract. El problema de desbalance en la clasificación se presenta en conjuntos de datos que tienen una cantidad grande de datos de cierto tipo (clase mayoritaria), mientras que el número de datos del tipo contrario es considerablemente menor (clase minoritaria). En este artículo se hace un breve resumen de la teoría de conjuntos aproximados basados en relaciones de similitud para su utilización en la implementación en Weka de tres filtros para tratar el problema de desbalance de cla...

  19. El método del aprendizaje basado en problemas como una herramienta para la enseñanza de las matemáticas

    Directory of Open Access Journals (Sweden)

    Víctor Castaño

    2015-05-01

    Full Text Available El Aprendizaje Basado en Problemas (ABP es una de las metodologías educativas que han tenido buena aceptación en instituciones universitarias en México. Es un proceso activo de aprendizaje que funciona mediante la solución de problemas relacionados con la interacción de los estudiantes y su entorno profesional. La esencia del ABP consiste en identificar, describir, analizar y resolver tales problemas, lo cual se logra con ayuda del docente, desempeñando así otro papel tanto el proceso de enseñanza-aprendizaje como los estudiantes

  20. Un nuevo conjunto de datos para la detección de roya en cultivos de café Colombianos basado en clasificadores

    OpenAIRE

    2014-01-01

    La producción de café es la principal actividad agrícola en Colombia. Más de 350.000 familias colombianas dependen de la cosecha de café. En este sentido, la roya fue reportada por primera vez en el país en 1983, y desde entonces estas familias han tenido que enfrentar graves consecuencias. Recientemente, diversos enfoques basados en aprendizaje automático han construido un conjunto de datos para el monitoreo de la incidencia de la roya del café, teniendo en cuenta las condiciones climáticas ...

  1. Diseño de un modelo de gestión basado en el cuadro de mando integral para una industria procesadora de acero

    OpenAIRE

    Freire Flores, Tannia Alejandra

    2015-01-01

    1. Introducción. --2.Planteamiento de la propuesta de trabajo. --3.Marco Teórico. --4.Metodología. --5.Resultados. --6. Conclusiones y recomendaciones La presente tesis tiene como finalidad mejorar los procesos internos de la empresa a través del diseño de un modelo de gestión basado en el cuadro de mando integral para una industria procesadora de acero, el mismo que inició con una investigación teórica que sirvió de sustento para su desarrollo, posteriormente se realizó un análisis del se...

  2. Programa de incentivo laboral basado en la innovación y creatividad del talento humano para la PUCE SEDE AMBATO

    OpenAIRE

    2015-01-01

    1. Introducción.-- 2. Planteamiento de la propuesta de trabajo.-- 3. Marco Teórico.-- 4. Metodología.-- 5. Resultados.-- 6. Conclusiones y Recomendaciones.-- La investigación tiene como objetivo diseñar un programa de incentivo laboral (PDI) basado en la innovación y creatividad del talento humano para la PUCESA. La investigación evidencia como problema más representativo: el nivel de absentismo laboral, y la falta de compromiso del personal con la institución. El estudio conceptual analiz...

  3. Modelos interactivos de aprendizaje basado en tecnología para la inclusión social de bajo costo y aplicaciones multi-usuarios

    OpenAIRE

    Castillo, Emilce Soledad; Fus, Cesar Daniel; Sosa Zitto, Rossana; Rapallini, Ulises Mario Alberto; Velazquez, Eduardo; Blanc, Rafael Luján; Lepratte, Leandro Omar

    2014-01-01

    El presente trabajo surge del Núcleo de Investigación en Tecnologías para la Inclusión Social de la Facultad de Ciencia y Tecnología de la Universidad Autónoma de Entre Ríos de la Sede Concepción del Uruguay. El mismo impulsa un proyecto sobre Modelos interactivos de aprendizajes basado en tecnologías para la inclusión social de bajo costo y aplicaciones multiusuarios. Se busca crear una solución práctica para la educación inclusiva, implementando Tics, destinada a personas con discapacida...

  4. Control adaptativo por modelo de referencia para un inversor basado en LCL con Síntesis de Controlador Mínima

    OpenAIRE

    Larco Barros, Ciro Mauricio; Costa Castelló, Ramon; Olm Miras, Josep Maria

    2016-01-01

    Un Control Adaptativo por Modelo de Referencia MRAC con Síntesis de Controlador Mínima MCS, es desarrollado con el objetivo de controlar un Inversor monofásico basado en un Filtro LCL conectado a la Red Eléctrica y adaptar el inductor de la red, que es un parámetro desconocido y que generá incertidumbre, manteniendo las prestaciones y la robustez del sistema. Para ello primero se revisarán los algoritmos de MRAC y MCS, y en función de estos se muestran todos los pasos a seguir y los co...

  5. Desarrollo y caracterización de electrodos catalíticos basados en polímeros conductores de polipirrol y polianilina sobre diferentes sustratos

    OpenAIRE

    Molina Puerto, Javier

    2011-01-01

    Durante los últimos años el desarrollo de tejidos con nuevas propiedades ha sido un campo muy activo. Por ejemplo se han creado tejidos con propiedades termorreguladoras a partir de microcápsulas con materiales que cambian de fase, tejidos autolimpiables, tejidos con acabados hidrófobos, etc. Otro de los campos que se ha estado explorando es el de los tejidos conductores de la electricidad; sobre el cual trata la presente tesis. Se han desarrollado productos basados en tejidos conductores de ...

  6. Plataforma experimental para el desarrollo y evaluación de sistemas de generación híbridos basados en pilas de combustible

    OpenAIRE

    Talpone, Juan Ignacio; Puleston, Pablo Federico; Moré, Jerónimo José; Griñó, Robert; Cendoya, Marcelo G.

    2013-01-01

    La creciente demanda de energía, la constante disminución de las fuentes de origen fósil y la preocupación por el deterioro del medio ambiente, han volcado la atención mundial a las tecnologías basadas en fuentes de energía alternativas. El perfeccionamiento de sistemas de generación eléctrica eficientes basados en energías alternativas, actualmente se ha convertido en un área de investigación y desarrollo de crucial importancia. En este contexto en constante expansión, las investigaciones en...

  7. Incorporación de la fase Zn7Sb2O12 previamente sintetizada en varistores cerámicos basados en ZnO

    OpenAIRE

    Peiteado, M.; Fernández Lozano, José Francisco; Caballero Cuesta, Amador

    2002-01-01

    [ES] Una de las reacciones que tiene lugar durante la sinterización de varistores cerámicos basados en el sistema ZnO-Bi2O3-Sb2O3 es la formación de la fase Zn7Sb2O12, de estructura tipo espinela, que ocurre en el intervalo de temperaturas comprendido entre 900 y 1100ºC, dependiendo de la composición específica del material. Esta fase es la responsable del control del crecimiento de grano y su distribución en el seno del material como una segunda fase dispersa en la matriz mayoritari...

  8. El Aprendizaje Basado en la Resolución de Problemas y su efectividad en el Desarrollo de la Metacognición

    OpenAIRE

    Ley Fuentes, Martha Georgina

    2014-01-01

    Esta investigación tuvo como propósito determinar la efectividad del aprendizaje basado en la resolución de problemas, en el desarrollo de la metacognición de estudiantes universitarios de una universidad virtual. Para determinar la efectividad de la estrategia de resolución de problemas en el desarrollo de la metacognición de los estudiantes, se implementó un diseño cuasi experimental, con pre y post test. En la investigación participaron 34 estudiantes, que ...

  9. Un modelo de migración humana: experimentos numéricos basados sobre los datos de las tres ciudades laguneras

    OpenAIRE

    Vyacheslav Kalashnikov; Nataliya Kalashnykova; Ramón Luévanos Rojas; Mario Méndez Muños; César Uranga; Arnulfo Luévanos Rojas

    2007-01-01

    Se aplica un modelo de migración humana al estudio de crecimiento de población en las tres ciudades aglomeradas en la región Lagunera de México. Se introducen tres tipos de funciones de utilidad para distintos grupos de población, y se investiga un equilibrio con variaciones conjeturales. Los experimentos numéricos basados en datos de las tres ciudades muestran la fuerte influencia de los coeficientes de variaciones conjeturales sobre la actividad migratoria esperada.

  10. Un modelo de migración humana: experimentos numéricos basados sobre los datos de las tres ciudades laguneras

    Directory of Open Access Journals (Sweden)

    Vyacheslav Kalashnikov

    2007-01-01

    Full Text Available Se aplica un modelo de migración humana al estudio de crecimiento de población en las tres ciudades aglomeradas en la región Lagunera de México. Se introducen tres tipos de funciones de utilidad para distintos grupos de población, y se investiga un equilibrio con variaciones conjeturales. Los experimentos numéricos basados en datos de las tres ciudades muestran la fuerte influencia de los coeficientes de variaciones conjeturales sobre la actividad migratoria esperada.

  11. Diseño de un modelo de gestion basado en el plan estrategico para agencias de viajes y operadoras de turismo

    OpenAIRE

    Pazmiño Lopez, Paulina Soledad

    2015-01-01

    1. Introducción. --2. Planteamiento de la Propuesta de Trabajo. --3. Marco Teórico. --4. Metodología. --5. Resultados. --6.Conclusiones y Recomendaciones El modelo de gestión basado en el plan estratégico que a continuación se presenta se enfoca en el mejoramiento continuo de las Agencias de Viajes y Operadoras de Turismo, las cuales requieren innovar constantemente sus procesos administrativos mediante la aplicación de estrategias corporativas, con el fin de fortalecer sus ventas y lograr...

  12. Diseño de un modelo de gestión basado en el cuadro de mando integral para una industria procesadora de acero

    OpenAIRE

    Freire Flores, Tannia Alejandra

    2015-01-01

    1. Introducción. --2.Planteamiento de la propuesta de trabajo. --3.Marco Teórico. --4.Metodología. --5.Resultados. --6. Conclusiones y recomendaciones La presente tesis tiene como finalidad mejorar los procesos internos de la empresa a través del diseño de un modelo de gestión basado en el cuadro de mando integral para una industria procesadora de acero, el mismo que inició con una investigación teórica que sirvió de sustento para su desarrollo, posteriormente se realizó un análisis del se...

  13. Programa de metodología didáctica para la mejora de la inteligencia emocional y el Aprendizaje Basado en Problemas (ABP)

    OpenAIRE

    Escribano González, Alicia; Bejarano Franco, Mª Teresa; Zúñiga Fernández, Mª Ángeles; Fernández Gijón, José Luis

    2010-01-01

    Esta investigación se centra en las inteligencias:”lógico-matemática”, “intrapersonal” e “interpersonal” formuladas por Gardner (2003) en su teoría de las inteligencias múltiples. Por una parte, se relacionó la inteligencia lógico matemática con el Aprendizaje Basado en Problemas (ABP) que constituye una metodología que impulsa el aprendizaje mediante el análisis y la solución de problemas. Por otra, se relacionó las inteligencias intrapersonal e interpersonal con la aplicac...

  14. Diseño y aplicación de sensores electroquímicos basados en moléculas orgánicas conductoras

    OpenAIRE

    Cano Luna, Manuel

    2011-01-01

    La presente Tesis Doctoral, titulada "Diseño y Aplicación de Sensores Electroquímicos basados en Moléculas Orgánicas Conductoras", pretende avanzar en el conocimiento de los materiales orgánicos conductores, y su potencial aplicación como electrodos de trabajo, sensores o biosensores electroquímicos, tanto en sistemas en continuo (FIA) como en discontinuo. La organización de los resultados experimentales se ha realizado de acuerdo con la modalidad establecida por la Comisión de Doctorado d...

  15. Cambios en las concesiones viales en Uruguay: un análisis basado en la teoría de subastas

    Directory of Open Access Journals (Sweden)

    Andrés Pereyra

    2010-06-01

    Full Text Available Este trabajo analiza el impacto de la privatización de un concesionario vial de propiedad estatal sobre el valor de las inversiones futuras, considerando que el gobierno puede manejar la asimetría de información con el concesionario. Mediante un modelo basado en la teoría de subastas se estima el impacto, para el gobierno, de privatizar al concesionario sin modificar el contrato vigente. Si se decidiera privatizar al concesionario, se requerían modificaciones significativas en el contrato, especialmente si no hay cambios institucionales que mejoren la capacidad de supervisión y control del gobierno.

  16. Modelo de negocio basado en CANVAS para un proyecto de implementación de un parque de diversiones infantiles en la ciudad de Cuenca

    OpenAIRE

    Vásquez Benavidez, Ana del Rocío

    2016-01-01

    En este trabajo se presenta un Modelo de Negocio basado en CANVAS para un proyecto de implementación de un parque de diversiones infantiles en la ciudad de Cuenca, el principal objetivo fue determinar la factibilidad tanto financiera como social del mismo. Lo cual se pudo demostrar mediante el uso de indicadores como el VAN y el TIR. This work is a business model based on CANVAS for an implementation project in the city of Cuenca children's amusement park, the main objective was to determi...

  17. Solución de ecuaciones de grado superior mediante estrategias de aprendizaje basado en problemas y el uso de objetos de aprendizaje

    OpenAIRE

    Ulloa, Ricardo; Estrada, Ana Luisa

    2007-01-01

    Con la investigación objeto de este reporte, se estudiaron los efectos que tiene una propuesta didáctica centrada en el enfoque de Aprendizaje Basado en Problemas (ABP) y con empleo de Objetos para el Aprendizaje (LO), sobre el aprendizaje del tema ecuaciones de grado superior, por parte de alumnos de segundo de la Licenciatura en Matemática Educativa (LME) de la Universidad Autónoma de Nayarit (UAN). La etapa de experimentación se llevó a cabo durante tres meses. Se empleó como marco teórico...

  18. Taller multidisciplinario dirigido a pacientes pediátricos con asma y sus padres, basado en la Guía Internacional para el Manejo del Asma (GINA)

    OpenAIRE

    Georgina E. Bazán Riverón; Mirna Patricia Paredes Rivera; Maricela Osorio Guzmán

    2007-01-01

    El presente estudio tiene como objetivo mejorar la calidad de vida de pacientes con asma, mediante un taller basado en la Guía Internacional para el Manejo del Asma (GINA). Participó un grupo de 10 pacientes con edades entre 1,5 y 6 años con sus padres; el estudio fue transversal, con un diseño preprueba-posprueba, e incluyó un grupo testigo. El taller multidisciplinario para padres e hijos con asma trató temas de adherencia, tratamiento de sostén y asistencia en crisis; su duración fue de ci...

  19. Diseño y construcción de un pedal de bicicleta basado en sensores piezorresistivos para determinar la fuerza resultante

    OpenAIRE

    Osorio-Valencia, J. S. (Juan Sebastián); Gómez-Cardona, S. (Sebastian); Restrepo-Mejía, S. (Sebastián)

    2007-01-01

    En el ciclismo colombiano, las pautas de entrenamiento se ajustan a partir de datos cualitativos basados en la observación directa al deportista. Esta investigación busca mejorar ese proceso por medio de la implementación de pedales instrumentados para obtener datos cuantitativos del rendimiento del ciclista. En este artículo se presenta el diseño y construcción de un prototipo de dispositivo dinamométrico que permite la captura de datos de fuerza en el pedal durante el gesto del pedaleo. El ...

  20. Diseño y desarrollo de un simulador de adquisición de entradas digitales y actuadores basado en microcontrolador PIC

    OpenAIRE

    Páez Espinosa, Alejandro Daniel

    2013-01-01

    El proyecto final de carrera consistirá en el diseño y desarrollo de un simulador de adquisición de entradas digitales gestionada mediante de comunicación puerto serie y Ethernet mediante protocolo UDP. El servicio UDP estará basado en microcontrolador PIC18F mediante el modulo ENC28J60. En este proyecto asimismo se realiza el diseño de un controlador (API) que emulará los drivers de la tarjeta basada en PIC18F y que abstraerá la lógica de bajo nivel, siendo posible su ut...