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Sample records for agr reactor windscale

  1. Windscale advanced gas-cooled reactor (WAGR) decommissioning project overview

    International Nuclear Information System (INIS)

    The current BNFL reactor decommissioning projects are presented. The projects concern power reactor sites at Berkely, Trawsfynydd, Hunterstone, Bradwell, Hinkley Point; UKAEA Windscale Pile 1; Research reactors within UK Scottish Universities at East Kilbride and ICI (both complete); WAGR. The BNFL environmental role include contract management; effective dismantling strategy development; implementation and operation; sentencing, encapsulation and transportation of waste. In addition for the own sites it includes strategy development; baseline decommissioning planning; site management and regulator interface. The project objectives for the Windscale Advanced Gas-Cooled Reactor (WAGR) are 1) Safe and efficient decommissioning; 2) Building of good relationships with customer; 3) Completion of reactor decommissioning in 2005. The completed WAGR decommissioning campaigns are: Operational Waste; Hot Box; Loop Tubes; Neutron Shield; Graphite Core and Restrain System; Thermal Shield. The current campaign is Lower Structures and the remaining are: Pressure vessel and Insulation; Thermal Columns and Outer Vault Membrane. An overview of each campaign is presented

  2. Reactor fault simulation at the closure of the Windscale advanced gas-cooled reactor: analysis of reactor transient tests

    International Nuclear Information System (INIS)

    The testing of fault transient analysis methods by direct simulation of fault sequences on a commercial reactor is clearly excluded on safety and economic grounds. The closure of the Windscale prototype advanced gas-cooled reactor (WAGR) therefore offered a unique opportunity to test fault study methods under extreme conditions relatively unfettered by economic constraints, although subject to appropriate safety regulations. One aspect of these important experiments was a series of reactor transient tests. The objective of these reactor transients was to increase confidence in the fault study computer models used for commercial AGR safety assessment by extending their range of validation to cover large amplitude and fast transients in temperature, power and flow, relevant to CAGR faults, and well beyond the conditions achievable experimentally on commercial reactors. A large number of tests have now been simulated with the fault study code KINAGRAX. Agreement with measurement is very good and sensitivity studies show that such discrepancies as exist may be due largely to input data errors. It is concluded that KINAGRAX is able to predict steady state conditions and transient amplitudes in both power and temperature to within a few percent. (author)

  3. Measurement of sulphur-35 in the coolant gas of the Windscale Advanced Gas-Cooled Reactor

    International Nuclear Information System (INIS)

    Sulphur is an important element in some food chains and the release of radioactive sulphur to the environment must be closely controlled if the chemical form is such that it is available or potentially available for entering food chains. The presence of sulphur-35 in the coolant gas of the Windscale Advanced Gas-Cooled Reactor warranted a study to assess the quantity and chemical form of the radioactive sulphur in order to estimate the magnitude of the potential environmental hazard which might arise from the release of coolant gas from Civil Advanced Gas-Cooled Reactors. A combination of gas chromatographic and radiochemical analyses revealed carbonyl sulphide to be the only sulphur-35 compound present in the coolant gas of the Windscale Reactor. The concentration of carbonyl sulphide was found to lie in the range 40 to 100 x 10-9 parts by volume and the sulphur-35 specific activity was about 20 mCi per gramme. The analytical techniques are described in detail. The sulphur-35 appears to be derived from the sulphur and chlorine impurities in the graphite. A method for the preparation of carbonyl sulphide labelled with sulphur-35 is described. (author)

  4. The Windscale inquiry

    International Nuclear Information System (INIS)

    The three questions posed by Mr. Justice Parker at the onset of the enquiry, namely, 1. Should oxide fuel from UK reactors be reprocessed in this country. 2. If yes, should it be at Windscale and 3. If yes, should the plant be used to process foreign fuels are discussed in relation to the findings of the enquiry. (UK)

  5. Description of the advanced gas cooled type of reactor (AGR)

    International Nuclear Information System (INIS)

    The present report comprises a technical description of the Advanced Gas cooled Reactor (AGR), a reactor type which has only been built in Great Britain. 14 AGR reactors have been built, located at 6 different sites and each station is supplied with twin-reactors. The Torness AGR plant on the Lothian coastline of Scotland, 60 km east of Edinburgh, has been chosen as the reference plant and is described in some detail. Data on the other 6 stations, Dungeness B, Hinkely Point B, Hunterston G, Hartlepool, Heysham I and Heysham II, are given only in tables with a summary of design data. Where specific data for Torness AGR has not been available, corresponding data from other AGR plans has been used, primarily from Heysham II, which belongs to the same generation of AGR reactors. The information presented is based on the open literature. The report is written as a part of the NKS/RAK-2 subproject 3: 'Reactors in Nordic Surroundings', which comprises a description of nuclear power plants neighbouring the Nordic countries. (au) 11 refs

  6. Methods of Control-Rod Calibration in the Windscale Advanced Gas-Cooled Reactor

    International Nuclear Information System (INIS)

    Different techniques were used to calibrate control rods and to measure individual rod worths during the commissioning of the WAGR. These methods are described and the results are presented. The methods described are: (a ) Air poisoning - Changes in air pressure allow axial movement of rods at the critical condition. Thus rod movement can be related to pressure variation which is equivalent to a reactivity change. Also, rod slope measurements can be made for different rod insertions. (b) Rod slopes - The rods are withdrawn to make the reactor supercritical; then later they are inserted to make the reactor subcritical. From a measurement of the doubling and halving times the change in reactivity between the super- and subcritical states can be determined.- (c ) Absorber addition and withdrawal - The number of fixed localized absorbers is varied to give a method similar to the use of uniform air poisoning. (d) Pulsatron - This technique is used to give subcritical measurements of rod worth. (e) Rod run-in - The reactor is initially critical, and then the rods are run into the core. Analysis of the flux response relates reactivity to rod movement. (author)

  7. The Windscale enquiry

    International Nuclear Information System (INIS)

    Comments are made on some of the recommendations in the inspector's report on the proposal to build a reprocessing plant for thermal oxide fuel at Windscale, and on some of the arguments put forward at the public inquiry. The subjects discussed are: safety and the assessment of risk; treatment of highly radioactive wastes; alternative energy sources and energy conservation by domestic thermal insulation; and the question whether processing for foreign countries at Windscale might increase the risks of nuclear weapons proliferation. The paper ends with comments on the press coverage of the public inquiry and on the standard of the inquiry itself. (U.K.)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-04-01

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

  9. The Windscale Fire, October 1957

    International Nuclear Information System (INIS)

    This report contains a review of the scientific literature relating to the Windscale reactor accident in 1957. In particular, dose calculations are examined. It is found that hitherto no computation of the collective dose has been published. The report finds that computation of collective doses according to internationally accepted models leads to the conclusion that the accident produced several late effects such as deaths from cancer. Included is a survey of official statistics including thyroid cancer mortality, other cancers, infant mortality and stillbirths. No significant deviation from the expected rates has been observed in those areas affected by the fall-out from the accident, and thus it can be concluded that the dose-effect models are not wildly inaccurate. It is concluded, however, that in view of the latent period for thyroid cancers, and of the low incidence of these diseases, a more detailed survey would present an opportunity to test the accuracy of the thyroid dose-effect model. (author)

  10. Penney's Windscale thoughts

    International Nuclear Information System (INIS)

    The paper concerns the official file on the nuclear fire at Windscale in October 1957, which was written by Sir William Penney. The file was based on a 10-day investigation, and describes the physical causes and consequences of the fire. The events of the accident are described, along with the political events of the time concerning the U.S.A. and nuclear weapons, attempts to put out the fire, iodine fall-out in the milk, and polonium 210 contamination. (UK)

  11. Society's response to Windscale

    International Nuclear Information System (INIS)

    In surveying public attitudes to the proposals for expansion at Windscale consideration is given to events leading to the public enquiry, comments on the inquiry itself, and the issues raised in discussions and demonstrations which followed. Some drawbacks are pointed out concerning alternative sources of energy which have been suggested. The question of risk and some recent estimations or risks involved in various industries and activities are discussed. The philosophy of protest is discussed and attention is paid to the suggestion for special procedures for public consultation as envisaged by the Secretary of State for the Environment. (U.K.)

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

    Energy Technology Data Exchange (ETDEWEB)

    Blaine Grover

    2012-10-01

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

  13. Irradiation performance of AGR-1 high temperature reactor fuel

    Energy Technology Data Exchange (ETDEWEB)

    Paul A. Demkowicz; John D. Hunn; Robert N. Morris; Charles A. Baldwin; Philip L. Winston; Jason M. Harp; Scott A. Ploger; Tyler Gerczak; Isabella J. van Rooyen; Fred C. Montgomery; Chinthaka M. Silva

    2014-10-01

    The AGR-1 experiment contained 72 low-enriched uranium oxide/uranium carbide TRISO-coated particle fuel compacts in six capsules irradiated to burnups of 11.2 to 19.5% FIMA, with zero TRISO coating failures detected during the irradiation. The irradiation performance of the fuel–including the extent of fission product release and the evolution of kernel and coating microstructures–was evaluated based on detailed examination of the irradiation capsules, the fuel compacts, and individual particles. Fractional release of 110mAg from the fuel compacts was often significant, with capsule-average values ranging from 0.01 to 0.38. Analysis of silver release from individual compacts indicated that it was primarily dependent on fuel temperature history. Europium and strontium were released in small amounts through intact coatings, but were found to be significantly retained in the outer pyrocrabon and compact matrix. The capsule-average fractional release from the compacts was 1×10 4 to 5×10 4 for 154Eu and 8×10 7 to 3×10 5 for 90Sr. The average 134Cs release from compacts was <3×10 6 when all particles maintained intact SiC. An estimated four particles out of 2.98×105 experienced partial cesium release due to SiC failure during the irradiation, driving 134Cs release in two capsules to approximately 10 5. Identification and characterization of these particles has provided unprecedented insight into the nature and causes of SiC coating failure in high-quality TRISO fuel. In general, changes in coating morphology were found to be dominated by the behavior of the buffer and inner pyrolytic carbon (IPyC), and infrequently observed SiC layer damage was usually related to cracks in the IPyC. Palladium attack of the SiC layer was relatively minor, except for the particles that released cesium during irradiation, where SiC corrosion was found adjacent to IPyC cracks. Palladium, silver, and uranium were found in the SiC layer of irradiated particles, and characterization

  14. The Windscale 1957 fire and the lessons gained

    International Nuclear Information System (INIS)

    In 1957 the Windscale-1 reactor (UK), devoted to military nuclear weapon research, was destroyed by fire during an operation of Wigner energy evacuation from the graphite core. This accident was the most serious known before the TMI event in 1979 and the radioactive releases in the atmosphere were highly greater. This paper gives a general description of the Windscale reactors principle with some details about the Wigner effect and the graphite annealing procedure developed to counterbalance this effect. Then, it describes the accident itself and the emergency procedure followed to extinguish the fire. Finally, as a consequence of the accident, several analyses and inquiries were carried out to study the details of the accident and to determine its environmental impact. These studies have led to the creation of the U.K. Nuclear Inspectorate. (J.S). 4 refs

  15. Decommissioning of Windscale pile 1

    International Nuclear Information System (INIS)

    The Windscale Piles were constructed in the late 1940's primarily for the production of plutonium in support of the British atomic weapons programme. In 1957 Pile 1 suffered a fire during the routine release of stored Wigner energy by nuclear heating. Following the fire as much material as possible was recovered, an inventory and status report prepared and the pile sealed and placed under surveillance and maintenance, the only practicable option at the time. Over the last decade in addition to general improvements in routine monitoring equipment there has been extensive investigative work carried out to better understand the damage caused by the fire and assess the options for further action. These studies concluded that the preferred option was for the Pile core to be removed, treated and packaged for intermediate storage prior to final disposal. The paper will describe the core investigations, the assessed conditions, and the options considered. It will also describe the tendering process to allow contractors to propose solutions against a cardinal point specification, the outline of the preferred solution and the progress of the work to date. (author)

  16. A UKAEA review of gas-cooled reactors in the United Kingdom

    International Nuclear Information System (INIS)

    The commercial use of nuclear power for electrical generation commenced in the UK in the 1950s with the Calder Hall reactors. Based on this concept, eighteen commercial reactor units, with two further units outside the UK, were constructed and have been in operation for periods ranging from 10 to 19 years. The paper reviews this experience mainly from the aspects of safety and the achieved costs, which compare favourably with current figures for fossil fired generation. The further development of the gas-cooled system in the UK commenced with the construction of the Windscale AGR, which came into operation in 1962. This led to the ordering of 14 large commercial AGR units, 4 of which have been in service since 1976, 6 are at an advanced stage of construction and 4 are at an early stage of construction. The paper reviews the main safety features of the AGR and considers the costs, taking achieved costs for the units which are in service and a combination of historical costs and projected costs for the units under construction. Again a clear advantage over fossil fuelled stations is shown. The paper also includes a preliminary account of the use of the prototype AGR at Windscale for the series of experiments concerning plateout, over-temperature in the fuel and simulated fault transients in the core which were carried out earlier in 1981. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

    Blaine Grover

    2012-10-01

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

  18. A review of irradiated fuel particle releases from the Windscale Piles, 1950-1957

    International Nuclear Information System (INIS)

    Radiological assessments have assumed that the mass of irradiated uranium oxide particles inadvertently released to the atmosphere from the Windscale Piles, two nuclear reactors at Windscale Works, Sellafield, England, during the 1950s was 20 kg. This paper re-examines the assumptions upon which this figure was based and concludes that the value is a realistically conservative estimate of the release, consistent with current radiological protection practice. The mass estimate is derived from a reanalysis of plant data produced at the time. The environmental data on which the initial estimates were based are reconfirmed, and additional support is provided by an interpretation of modelling studies of both the total deposition and milk concentrations resulting from that deposition. Milk-monitoring data from the time are shown to be consistent with the release assumptions used in the dispersion modelling exercise. Finally, the issue of statistical undersampling is addressed using the particle numbers and size distributions produced by the modelling exercise

  19. After Parker: A review of the Windscale inquiry and subsequent developments

    International Nuclear Information System (INIS)

    For 100 days in 1977, an Inquiry, conducted by Mr. Justice Parker, was held in Great Britain to look at the implications of building a plant at Windscale, on the Cumbrian coast, to reprocess oxide fuel from thermal nuclear reactors. The events, beginning with two public debates before the Inquiry and extending through two debates in the House of Commons after the publication of Mr. Justice Parker's report, and the decision by Parliament, on 15 May 1978 to proceed with the thermal oxide reprocessing plant (THORP) are briefly reviewed. The attitudes and published opinions of the organizations opposed to the plant construction, to the whole evaluation process are discussed

  20. The Windscale Inquiry: the public inquiry system on trial

    International Nuclear Information System (INIS)

    This thesis is concerned with the Windscale Inquiry of 1977 and its effect on the public inquiry system. It focusses both on the major influences of the Windscale Inquiry process, and on the participants, their aims, motivations, expectations and achievements. It provides the most detailed examination of the Inquiry to date and, as a result, uncovers aspects of the process while have not been explored previously. The central questions of the thesis are: Was the outcome of the Windscale Inquiry inevitable or could it have reached different conclusions? and did the Windscale Inquiry demonstrate that the public inquiry system could be used by a government to reach a decision which it favoured? The thesis argues that the outcome of the Windscale Inquiry was almost inevitable. In fact it was found that the Inspector had made up his mind in favour of oxide reprocessing before the Inquiry opened. However, this finding does not express fully the Inquiry's impact, because, as the thesis shows, the Inquiry became a mechanism which forced the nuclear industry and the government to explain, and substantially alter, some parts of their policies. The process of bringing the government and industry to account, did not alter the THORP decision, but it demonstrated that any subsequent inquiries could subject nuclear developments to searching criticism and investigation. Indeed it is suggested that the Windscale Inquiry made it impossible for subsequent Governments to proceed with nuclear expansion without subjecting them to the public inquiry process. Part I of the thesis examines the history and structure of the public Inquiry system and the relevant aspects of planning law. Part II describes the history of reprocessing and the themes which led to the public inquiry being established. Part III forms the most detailed part of the thesis and examines the Windscale Inquiry process focussing on the participants and the issues involved. (author)

  1. Performance of AGR-1 High-Temperature Reactor Fuel During Post-Irradiation Heating Tests

    Energy Technology Data Exchange (ETDEWEB)

    Morris, Robert Noel [ORNL; Baldwin, Charles A [ORNL; Hunn, John D [ORNL; Demkowicz, Paul [Idaho National Laboratory (INL); Reber, Edward [Idaho National Laboratory (INL)

    2014-01-01

    The fission product retention of irradiated low-enriched uranium oxide/uranium carbide TRISO fuel compacts from the AGR-1 experiment has been evaluated at temperatures of 1600 1800 C during post-irradiation safety tests. Fourteen compacts (a total of ~58,000 particles) with a burnup ranging from 13.4 to 19.1% FIMA have been tested using dedicated furnace systems at Idaho National Laboratory and Oak Ridge National Laboratory. The release of fission products 110mAg, 134Cs, 137Cs, 154Eu, 155Eu, 90Sr, and 85Kr was monitored while heating the fuel specimens in flowing helium. The behavior of silver, europium, and strontium appears to be dominated by inventory that was originally released through intact SiC coating layers during irradiation, but was retained in the compact at the end of irradiation and subsequently released during the safety tests. However, at a test temperature of 1800 C, the data suggest that release of these elements through intact coatings may become significant after ~100 h. Cesium was very well retained by intact SiC layers, with a fractional release <5 10-6 after 300 h at 1600 C or 100 h at 1800 C. However, it was rapidly released from individual particles if the SiC layer failed, and therefore the overall cesium release fraction was dominated by the SiC defect and failure fractions in the fuel compacts. No complete TRISO coating layer failures were observed after 300 h at 1600 or 1700 C, and 85Kr release was very low during the tests (particles with breached SiC, but intact outer pyrocarbon, retained most of their krypton). Krypton release from TRISO failures was only observed after ~210 h at 1800 C in one compact. Post-safety-test examination of fuel compacts and particles has focused on identifying specific particles from each compact with notable fission product release and detailed analysis of the coating layers to understand particle behavior.

  2. The DOE Advanced Gas Reactor (AGR) Fuel Development and Qualification Program

    Energy Technology Data Exchange (ETDEWEB)

    David Petti; Hans Gougar; Gary Bell

    2005-05-01

    The Department of Energy has established the Advanced Gas Reactor Fuel Development and Qualification Program to address the following overall goals: Provide a baseline fuel qualification data set in support of the licensing and operation of the Next Generation Nuclear Plant (NGNP). Gas-reactor fuel performance demonstration and qualification comprise the longest duration research and development (R&D) task for the NGNP feasibility. The baseline fuel form is to be demonstrated and qualified for a peak fuel centerline temperature of 1250°C. Support near-term deployment of an NGNP by reducing market entry risks posed by technical uncertainties associated with fuel production and qualification. Utilize international collaboration mechanisms to extend the value of DOE resources. The Advanced Gas Reactor Fuel Development and Qualification Program consists of five elements: fuel manufacture, fuel and materials irradiations, postirradiation examination (PIE) and safety testing, fuel performance modeling, and fission product transport and source term evaluation. An underlying theme for the fuel development work is the need to develop a more complete fundamental understanding of the relationship between the fuel fabrication process, key fuel properties, the irradiation performance of the fuel, and the release and transport of fission products in the NGNP primary coolant system. Fuel performance modeling and analysis of the fission product behavior in the primary circuit are important aspects of this work. The performance models are considered essential for several reasons, including guidance for the plant designer in establishing the core design and operating limits, and demonstration to the licensing authority that the applicant has a thorough understanding of the in-service behavior of the fuel system. The fission product behavior task will also provide primary source term data needed for licensing. An overview of the program and recent progress will be presented.

  3. AGR-1 Thermocouple Data Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Jeff Einerson

    2012-05-01

    This report documents an effort to analyze measured and simulated data obtained in the Advanced Gas Reactor (AGR) fuel irradiation test program conducted in the INL's Advanced Test Reactor (ATR) to support the Next Generation Nuclear Plant (NGNP) R&D program. The work follows up on a previous study (Pham and Einerson, 2010), in which statistical analysis methods were applied for AGR-1 thermocouple data qualification. The present work exercises the idea that, while recognizing uncertainties inherent in physics and thermal simulations of the AGR-1 test, results of the numerical simulations can be used in combination with the statistical analysis methods to further improve qualification of measured data. Additionally, the combined analysis of measured and simulation data can generate insights about simulation model uncertainty that can be useful for model improvement. This report also describes an experimental control procedure to maintain fuel target temperature in the future AGR tests using regression relationships that include simulation results. The report is organized into four chapters. Chapter 1 introduces the AGR Fuel Development and Qualification program, AGR-1 test configuration and test procedure, overview of AGR-1 measured data, and overview of physics and thermal simulation, including modeling assumptions and uncertainties. A brief summary of statistical analysis methods developed in (Pham and Einerson 2010) for AGR-1 measured data qualification within NGNP Data Management and Analysis System (NDMAS) is also included for completeness. Chapters 2-3 describe and discuss cases, in which the combined use of experimental and simulation data is realized. A set of issues associated with measurement and modeling uncertainties resulted from the combined analysis are identified. This includes demonstration that such a combined analysis led to important insights for reducing uncertainty in presentation of AGR-1 measured data (Chapter 2) and interpretation of

  4. Consequences of Windscale accident (October 1957) and study of the validity of the Sutton's mathematical model of atmospheric diffusion (1960)

    International Nuclear Information System (INIS)

    The reactor accident that happens at the number 1 pile of Windscale in 1957 was followed by a discharge of radioactive products into the atmosphere from the 1.X.1957 at 4.30 PM to the 12.X.1957 at 3.10 PM. On october the 11th it was possible to say that there was no more risk either of external irradiation or inhalation. But in adopting a M.A.C. of 0,1 μcurie of iodine 131 per litre of milk, the Authority had to control the milk delivery till november 23rd on a 500 km2 area. On the other hand, this exceptional accident permit to verify that Sutton's atmospheric diffusion model could give an easy means to foresee, with a sufficient approximation, the consequences of a dispersion of radioactive products into the atmosphere. (author)

  5. AGR-1, AGR-2 and AGR-3/4 Dimensional Change Data Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Herberger, Sarah E. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-02-01

    A series of Advanced Gas Reactor (AGR) experiments have been completed in the Advanced Test Reactor at Idaho National Laboratory in support of qualification and development of tristructural isotropic fuel. Each AGR test consists of multiple independently controlled and monitored capsules containing fuel compacts placed in a graphite cylinder. These capsules are instrumented with thermocouples embedded in the graphite, enabling temperature control. The fuel compacts are composed of fuel particles surrounded by a graphitic A3 matrix material. Dimensional change in AGR fuel compacts is vital because the swelling or shrinkage affects the size of the gas gaps that are used to control temperatures. Analysis of dimensional change in the AGR fuel compacts is needed to establish the variables directly relating to compact shrinkage. The variables initially identified for consideration were matrix density, compact density, fuel packing fraction, uranium loading, fuel particle diameter, cumulative fast neutron fluence, and volume average time average fuel temperature. In addition to the data available from the AGR experiments, the analysis included specimens formed from the same A3 matrix material used in Advanced Graphite Creep (AGC) experiments, which provide graphite creep data during irradiation for design and licensing purposes. The primary purpose of including the AGC specimens was to encompass dimensional behavior at zero packing fraction, zero uranium loading, and zero particle diameter. All possible combinations of first-order variable regressions were considered in the analysis. The study focused on identifying the best regression models for percent change in diameter, length, and volume. Bootstrap analysis was used to ensure the resulting regression models were robust and well-performing. The variables identified as very significant in predicting change in one or more dimensions (diameter, length, and volume) are volume average time average temperature, fast fluence

  6. AGR-1 Data Qualification Report

    Energy Technology Data Exchange (ETDEWEB)

    Michael Abbott

    2010-03-01

    ABSTRACT Projects for the very high temperature reactor (VHTR) Technology Development Office (TDO) program provide data in support of Nuclear Regulatory Commission licensing of the VHTR. Fuel and materials to be used in the reactor are tested and characterized to quantify performance in high temperature and high fluence environments. The VHTR program has established the NGNP Data Management and Analysis System (NDMAS) to ensure that VHTR data are (1) qualified for use, (2) stored in a readily accessible electronic form, and (3) analyzed to extract useful results. This document focuses on the first NDMAS objective. It describes the data streams associated with the first Advanced Gas Reactor experiment (AGR-1), the processing of these data within NDMAS, and reports the qualification status of the data. Data qualification activities within NDMAS for specific types of data are determined by the data qualification category assigned by the data generator. They include: (1) capture testing, to confirm that the data stored within NDMAS are identical to the raw data supplied, (2) accuracy testing, to confirm that the data are an accurate representation of the system or object being measured, and (3) documentation that the data were collected under an NQA-1 or equivalent quality assurance program. The NDMAS database processing and qualification status of the following five data streams is reported in this document: 1. Fuel fabrication data. All data have been processed into the NDMAS database and qualified (1,819 records). 2. Fuel irradiation data. Data from all 13 AGR-1 reactor cycles have been processed into the NDMAS database and tested. Of these, 85% have been qualified and 15% have failed NDMAS accuracy testing. 3. FPMS data. Reprocessed (January 2010) data from all 13 AGR-1 reactor cycles have been processed into the database and capture tested. Final qualification of these data will be recorded after QA approval of an Engineering Calculations and Analysis Report

  7. Safety testing of AGR-2 UO2 compacts 3-3-2 and 3-4-2

    Energy Technology Data Exchange (ETDEWEB)

    Hunn, John D. [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States); Morris, Robert Noel [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States); Baldwin, Charles A. [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States); Montgomery, Fred C. [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)

    2015-09-01

    Post-irradiation examination (PIE) is in progress on tristructural-isotropic (TRISO) coated-particle fuel compacts from the Advanced Gas Reactor (AGR) Fuel Development and Qualification Program second irradiation experiment (AGR-2) [Collin 2014]. The AGR-2 PIE will build upon new information and understanding acquired throughout the recently-concluded six-year AGR-1 PIE campaign [Demkowicz et al. 2015] and establish a database for the different AGR-2 fuel designs.

  8. The UK Windscale inquiry - towards the end of the nuclear debate

    International Nuclear Information System (INIS)

    In June, 1977 the Honourable Mr Justice Parker opened the Windscale Inquiry into an application by British Nuclear Fuels Limited for planning permission for 'a plant for reprocessing irradiated oxide nuclear fuels and support site services' at their Windscale and Calder works in Cumbria. The Report of the Inquiry, concluding in favour of the development, was presented in January, 1978. The consequent legislation authorising the construction of the plant was passed in the House of Commons in May, 1978 by 224 votes to 80. The author looks at the debate surrounding the enquiry

  9. AgrAbility Project

    Science.gov (United States)

    ... hours ago AgrAbility's 25 Years, 25 Stories Rosendo Ramirez is a farmworker in California, a job that ... Rosendo continues to work. www.agrability.org/25years/ramirez/ ... See More See Less Rosendo Ramirez: Ingenuity, perseverance, ...

  10. AGR-1 Safety Test Predictions using the PARFUME code

    Energy Technology Data Exchange (ETDEWEB)

    Blaise Collin

    2012-05-01

    The PARFUME modeling code was used to predict failure probability of TRISO-coated fuel particles and diffusion of fission products through these particles during safety tests following the first irradiation test of the Advanced Gas Reactor program (AGR-1). These calculations support the AGR-1 Safety Testing Experiment, which is part of the PIE effort on AGR-1. Modeling of the AGR-1 Safety Test Predictions includes a 620-day irradiation followed by a 300-hour heat-up phase of selected AGR-1 compacts. Results include fuel failure probability, palladium penetration, and fractional release of fission products. Results show that no particle failure is predicted during irradiation or heat-up, and that fractional release of fission products is limited during irradiation but that it significantly increases during heat-up.

  11. A comparison of the observed and the expected cancers of the haematopoietic and lymphatic systems among workers at Windscale

    International Nuclear Information System (INIS)

    Data are given about the cases of cancers of the haematopoietic and lymphatic systems among workers at Windscale Works, BNFL during the period 1950 to 1974. The number of cancers of these types expected to occur in the working population at Windscale has been estimated for the same period. For none of these types is the observed number of cancers significantly different at the 95% confidence level from that expected. (author)

  12. Uncertainty Quantification of Calculated Temperatures for the AGR-1 Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Binh T. Pham; Jeffrey J. Einerson; Grant L. Hawkes

    2013-03-01

    This report documents an effort to quantify the uncertainty of the calculated temperature data for the first Advanced Gas Reactor (AGR-1) fuel irradiation experiment conducted in the INL’s Advanced Test Reactor (ATR) in support of the Next Generation Nuclear Plant (NGNP) R&D program. Recognizing uncertainties inherent in physics and thermal simulations of the AGR-1 test, the results of the numerical simulations can be used in combination with the statistical analysis methods to improve qualification of measured data. Additionally, the temperature simulation data for AGR tests can be used for validation of the fuel transport and fuel performance simulation models. The crucial roles of the calculated fuel temperatures in ensuring achievement of the AGR experimental program objectives require accurate determination of the model temperature uncertainties. The report is organized into three chapters. Chapter 1 introduces the AGR Fuel Development and Qualification program and provides overviews of AGR-1 measured data, AGR-1 test configuration and test procedure, and thermal simulation. Chapters 2 describes the uncertainty quantification procedure for temperature simulation data of the AGR-1 experiment, namely, (i) identify and quantify uncertainty sources; (ii) perform sensitivity analysis for several thermal test conditions; (iii) use uncertainty propagation to quantify overall response temperature uncertainty. A set of issues associated with modeling uncertainties resulting from the expert assessments are identified. This also includes the experimental design to estimate the main effects and interactions of the important thermal model parameters. Chapter 3 presents the overall uncertainty results for the six AGR-1 capsules. This includes uncertainties for the daily volume-average and peak fuel temperatures, daily average temperatures at TC locations, and time-average volume-average and time-average peak fuel temperatures.

  13. Uncertainty Quantification of Calculated Temperatures for the AGR-1 Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Binh T. Pham; Jeffrey J. Einerson; Grant L. Hawkes

    2012-04-01

    This report documents an effort to quantify the uncertainty of the calculated temperature data for the first Advanced Gas Reactor (AGR-1) fuel irradiation experiment conducted in the INL's Advanced Test Reactor (ATR) in support of the Next Generation Nuclear Plant (NGNP) R&D program. Recognizing uncertainties inherent in physics and thermal simulations of the AGR-1 test, the results of the numerical simulations can be used in combination with the statistical analysis methods to improve qualification of measured data. Additionally, the temperature simulation data for AGR tests can be used for validation of the fuel transport and fuel performance simulation models. The crucial roles of the calculated fuel temperatures in ensuring achievement of the AGR experimental program objectives require accurate determination of the model temperature uncertainties. The report is organized into three chapters. Chapter 1 introduces the AGR Fuel Development and Qualification program and provides overviews of AGR-1 measured data, AGR-1 test configuration and test procedure, and thermal simulation. Chapters 2 describes the uncertainty quantification procedure for temperature simulation data of the AGR-1 experiment, namely, (i) identify and quantify uncertainty sources; (ii) perform sensitivity analysis for several thermal test conditions; (iii) use uncertainty propagation to quantify overall response temperature uncertainty. A set of issues associated with modeling uncertainties resulting from the expert assessments are identified. This also includes the experimental design to estimate the main effects and interactions of the important thermal model parameters. Chapter 3 presents the overall uncertainty results for the six AGR-1 capsules. This includes uncertainties for the daily volume-average and peak fuel temperatures, daily average temperatures at TC locations, and time-average volume-average and time-average peak fuel temperatures.

  14. AGR-2 AND AGR-3/4 RELEASE-TO-BIRTH RATIO DATA ANALYSIS

    Energy Technology Data Exchange (ETDEWEB)

    Pham, Binh T; Einerson, Jeffrey J; Scates, Dawn M; Maki, John T; Petti, David A

    2014-09-01

    A series of Advanced Gas Reactor (AGR) irradiation tests is being conducted in the Advanced Test Reactor at Idaho National Laboratory in support of development and qualification of tristructural isotropic (TRISO) low enriched fuel used in the High Temperature Gas-cooled Reactor (HTGR). Each AGR test consists of multiple independently controlled and monitored capsules containing fuel compacts placed in a graphite cylinder shrouded by a steel shell. These capsules are instrumented with thermocouples embedded in the graphite enabling temperature control. AGR configuration and irradiation conditions are based on prismatic HTGR technology distinguished primarily by the use of helium coolant, a low-power-density ceramic core capable of withstanding very high temperatures, and TRISO coated particle fuel. Thus, these tests provide valuable irradiation performance data to support fuel process development, qualify fuel for normal operating conditions, and support development and validation of fuel performance and fission product transport models and codes. The release-rate-to-birth-rate ratio (R/B) for each of fission product isotopes (i.e., krypton and xenon) is calculated from release rates in the sweep gas flow measured by the germanium detectors used in the AGR Fission Product Monitoring (FPM) System installed downstream from each irradiated capsule. Birth rates are calculated based on the fission power in the experiment and fission product generation models. Thus, this R/B is a measure of the ability of fuel kernel, particle coating layers, and compact matrix to retain fission gas atoms preventing their release into the sweep gas flow, especially in the event of particle coating failures that occurred during AGR-2 and AGR-3/4 irradiations. The major factors that govern gaseous radioactive decay, diffusion, and release processes are found to be material diffusion coefficient, temperature, and isotopic decay constant. For each of all AGR capsules, ABAQUS-based three

  15. AGR-2 Data Qualification Report for ATR Cycle 154B

    Energy Technology Data Exchange (ETDEWEB)

    Binh Pham; Jeff Einerson

    2014-01-01

    This report provides the data qualification status of Advanced Gas Reactor-2 (AGR-2) fuel irradiation experimental data from Advanced Test Reactor (ATR) Cycle 154B as recorded in the Nuclear Data Management and Analysis System (NDMAS). This is the last cycle of AGR-2 irradiation, as the test train was pulled from the ATR core during the outage portion of ATR Cycle 155A. The AGR-2 data streams addressed in this report include thermocouple (TC) temperatures, sweep gas data (flow rates including new Fission Product Monitoring (FPM) downstream flows from Fission Product Monitoring System (FPMS) detectors, pressure, and moisture content), and FPMS data (release rates and release-to-birth rate ratios [R/Bs]) for each of the six capsules in the AGR-2 experiment. The final data qualification status for these data streams is determined by a Data Review Committee (DRC) comprised of AGR technical leads, Sitewide Quality Assurance (QA), and NDMAS analysts. The Data Review Committee reviewed the data acquisition process, considered whether the data met the requirements for data collection as specified in QA-approved Very High Temperature Reactor (VHTR) data collection plans, examined the results of NDMAS data testing and statistical analyses, and confirmed the qualification status of the data as given in this report.

  16. AGR-1 Data Qualification Interim Report

    Energy Technology Data Exchange (ETDEWEB)

    Machael Abbott

    2009-08-01

    Projects for the very-high-temperature reactor (VHTR) program provide data in support of Nuclear Regulatory Commission licensing of the VHTR. Fuel and materials to be used in the reactor are tested and characterized to quantify performance in high temperature and high fluence environments. The VHTR Program has established the NGNP Data Management and Analysis System (NDMAS) to ensure that VHTR data are (1) qualified for use, (2) stored in a readily accessible electronic form, and (3) analyzed to extract useful results. This document focuses on the first NDMAS objective. It describes the data streams associated with the first Advanced Gas Reactor (AGR-1) experiment, the processing of these data within NDMAS, and reports the interim FY09 qualification status of the AGR-1 data to date. Data qualification activities within NDMAS for specific types of data are determined by the data qualification category, which is assigned by the data generator, and include: (1) capture testing, to confirm that the data stored within NDMAS are identical to the raw data supplied, (2) accuracy testing, to confirm that the data are an accurate representation of the system or object being measured, and (3) documentation that the data were collected under an NQA-1 or equivalent QA program. The interim qualification status of the following four data streams is reported in this document: (1) fuel fabrication data, (2) fuel irradiation data, (3) fission product monitoring system (FPMS) data, and (4) Advanced Test Reactor (ATR) operating conditions data. A final report giving the NDMAS qualification status of all AGR-1 data (including cycle 145A) is planned for February 2010.

  17. The Windscale inquiry and its impact on the national nuclear programme

    International Nuclear Information System (INIS)

    This lecture by the Director of Information Services, British Nuclear Fuels Ltd., endeavours to convey something of the flavour of the recent Windscale Inquiry that lasted for 100 days and the results of which encompassed about four million words. It is stated that in at least the short term nuclear power in this country will only expand at a rate that is acceptable to the general public, largely as influenced by members of parliament and the media, including the press. It probably will not expand at a rate acceptable to scientists or deemed necessary by them. The pressure that led to the inquiry will not lessen because the inquiry is over; if anything it will increase. Nevertheless, eventually the nuclear power industry must win and the public will be forced to learn to live with it since the alternative, a society short of energy, is intolerable. Unless the industry has a reasonably consistent work load and a reasonably consistent demand for its products it will become moribund. Comparisons are made with the history of the coal industry. It is believed that one of the main lessons to be learnt form the Windscale Inquiry is that the Nuclear Power Industry's immediate future lies largely in its own hands. An outline is included of the past and probable future work of British Nuclear Fuels Ltd. with emphasis on the reprocessing of irradiated oxide fuel. (author)

  18. Consequences of Windscale accident (October 1957) and study of the validity of the Sutton's mathematical model of atmospheric diffusion (1960); Etude des consequences de l'accident de Windscale (Octobre 1957) et de la validite du modele mathematique de diffusion atmospherique de Sutton (1960)

    Energy Technology Data Exchange (ETDEWEB)

    Doury, A. [Commissariat a l' Energie Atomique (S.C.R.G.R.) Saclay (France).Centre d' Etudes Nucleaires; Martin, J.J. [Electricite de France (EDF)(S.L.P.R.), 37 - Chinon (France)

    1960-07-01

    The reactor accident that happens at the number 1 pile of Windscale in 1957 was followed by a discharge of radioactive products into the atmosphere from the 1.X.1957 at 4.30 PM to the 12.X.1957 at 3.10 PM. On october the 11{sup th} it was possible to say that there was no more risk either of external irradiation or inhalation. But in adopting a M.A.C. of 0,1 {mu}curie of iodine 131 per litre of milk, the Authority had to control the milk delivery till november 23{sup rd} on a 500 km{sup 2} area. On the other hand, this exceptional accident permit to verify that Sutton's atmospheric diffusion model could give an easy means to foresee, with a sufficient approximation, the consequences of a dispersion of radioactive products into the atmosphere. (author) [French] L'accident survenu a la pile numero 1 de Windscale en 1957 a entraine l'emission de matieres radioactives dans l'atmosphere du 10 octobre a 16h30 au 12 octobre a 15h10. Le 11 octobre, on pouvait dire qu'il n'y avait plus de risque d'irradiation externe ni de danger par inhalation. Mais en adoptant une C.M.A. de 0,1 {mu}curie d'iode 131 par litre de lait, les autorites ont du reglementer la consommation du lait jusqu'au 23 novembre sur une etendue d'environ 500 km{sup 2}. D'autre part, cet accident exceptionnel a permis de verifier que le modele de diffusion atmospherique de Sutton pouvait fournir un moyen commode de prevoir avec une approximation suffisante les consequences d'une dispersion de produits radioactifs dans l'atmosphere. (auteur)

  19. Chemical cleaning of UK AGR boilers

    International Nuclear Information System (INIS)

    For a number of years, the waterside pressure drops across the advanced gas-cooled reactor (AGR) pod boilers have been increasing. The pressure drop increases have accelerated with time, which is the converse behaviour to that expected for rippled magnetite formation (rapid initial increase slowing down with time). Nonetheless, magnetite deposition remains the most likely cause for the increasing boiler resistances. A number of potential countermeasures have been considered in response to the boiler pressure drop increases. However, there was no detectable reduction in the rate of pressure drop increase. Chemical cleaning was therefore considered and a project to substantiate and then implement chemical cleaning was initiated. (authors)

  20. Dimethylamine as a replacement for ammonia dosing in the secondary circuit of an advanced gas-cooled reactor (AGR) power station

    Energy Technology Data Exchange (ETDEWEB)

    Armstrong, Chris; Mitchell, Malcolm S. [EDF Energy, Hartlepool Power Station, Hartlepool (United Kingdom); Bull, Andrew E.A.; Quirk, Graham P.; Rudge, Andy [EDF Energy Nuclear Generation, Barnwood, Gloucester (United Kingdom). Central Technical Organisation; Woolsey, Ian S.

    2012-06-15

    Increasing flow resistance observed over recent years within the helical once-through boilers in the four advanced gas-cooled reactors at Hartlepool and Heysham 1 Power Stations have reduced boiler performance, resulting in reductions in feedwater flow, steam temperatures, and power output and in the need to carry out periodic chemical cleaning. The root cause is believed to be the development of magnetite deposits with high flow impedance in the 9Cr1Mo evaporator section of the boiler tubing. To prevent continued increases in boiler flow resistance, dimethylamine is being trialled, in one of the four affected units, as a replacement to the conventional ammonia dosing. Dimethylamine increases the pH at temperature around the secondary circuit and, based on full scale boiler rig simulations, is expected to reduce iron transport and prevent flow resistance increases within the evaporator section of the boiler. The dimethylamine plant trial commenced in January 2011 and is ongoing. The feedwater concentration of dimethylamine has been increased progressively towards a final target value of 900 {mu}g . kg{sup -1} and its effect on iron transport and boiler pressure loss is being closely monitored. The high steam temperature (> 500 C) of the secondary circuit leads to some decomposition of dimethylamine, which is being carefully monitored at various locations around the circuit. The decomposition products identified with dimethylamine dosing include ammonia, methylamine, formic acid, carbon dioxide and, as yet, unidentified neutral organic species. The effect of dimethylamine dosing on iron transport and boiler pressure drops and its decomposition behaviour around the secondary circuit during the plant trial will be presented in this paper. (orig.)

  1. AGR-1 Post Irradiation Examination Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Demkowicz, Paul Andrew [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-08-01

    The post-irradiation examination (PIE) of the Advanced Gas Reactor (AGR)-1 experiment was a multi-year, collaborative effort between Idaho National Laboratory (INL) and Oak Ridge National Laboratory (ORNL) to study the performance of UCO (uranium carbide, uranium oxide) tristructural isotropic (TRISO) coated particle fuel fabricated in the U.S. and irradiated at the Advanced Test Reactor at INL to a peak burnup of 19.6% fissions per initial metal atom. This work involved a broad array of experiments and analyses to evaluate the level of fission product retention by the fuel particles and compacts (both during irradiation and during post-irradiation heating tests to simulate reactor accident conditions), investigate the kernel and coating layer morphology evolution and the causes of coating failure, and explore the migration of fission products through the coating layers. The results have generally confirmed the excellent performance of the AGR-1 fuel, first indicated during the irradiation by the observation of zero TRISO coated particle failures out of 298,000 particles in the experiment. Overall release of fission products was determined by PIE to have been relatively low during the irradiation. A significant finding was the extremely low levels of cesium released through intact coatings. This was true both during the irradiation and during post-irradiation heating tests to temperatures as high as 1800°C. Post-irradiation safety test fuel performance was generally excellent. Silver release from the particles and compacts during irradiation was often very high. Extensive microanalysis of fuel particles was performed after irradiation and after high-temperature safety testing. The results of particle microanalysis indicate that the UCO fuel is effective at controlling the oxygen partial pressure within the particle and limiting kernel migration. Post-irradiation examination has provided the final body of data that speaks to the quality of the AGR-1 fuel, building

  2. AGR-1 Post Irradiation Examination Final Report

    International Nuclear Information System (INIS)

    The post-irradiation examination (PIE) of the Advanced Gas Reactor (AGR)-1 experiment was a multi-year, collaborative effort between Idaho National Laboratory (INL) and Oak Ridge National Laboratory (ORNL) to study the performance of UCO (uranium carbide, uranium oxide) tristructural isotropic (TRISO) coated particle fuel fabricated in the U.S. and irradiated at the Advanced Test Reactor at INL to a peak burnup of 19.6% fissions per initial metal atom. This work involved a broad array of experiments and analyses to evaluate the level of fission product retention by the fuel particles and compacts (both during irradiation and during post-irradiation heating tests to simulate reactor accident conditions), investigate the kernel and coating layer morphology evolution and the causes of coating failure, and explore the migration of fission products through the coating layers. The results have generally confirmed the excellent performance of the AGR-1 fuel, first indicated during the irradiation by the observation of zero TRISO coated particle failures out of 298,000 particles in the experiment. Overall release of fission products was determined by PIE to have been relatively low during the irradiation. A significant finding was the extremely low levels of cesium released through intact coatings. This was true both during the irradiation and during post-irradiation heating tests to temperatures as high as 1800°C. Post-irradiation safety test fuel performance was generally excellent. Silver release from the particles and compacts during irradiation was often very high. Extensive microanalysis of fuel particles was performed after irradiation and after high-temperature safety testing. The results of particle microanalysis indicate that the UCO fuel is effective at controlling the oxygen partial pressure within the particle and limiting kernel migration. Post-irradiation examination has provided the final body of data that speaks to the quality of the AGR-1 fuel, building

  3. AGR-2 Irradiation Test Final As-Run Report

    Energy Technology Data Exchange (ETDEWEB)

    Collin, Blaise P. [Idaho National Lab. (INL), Idaho Falls, ID (United States). VHTR Program

    2014-08-01

    This document presents the as-run analysis of the AGR-2 irradiation experiment. AGR-2 is the second of the planned irradiations for the Advanced Gas Reactor (AGR) Fuel Development and Qualification Program. Funding for this program is provided by the U.S. Department of Energy as part of the Very High Temperature Reactor (VHTR) Technology Development Office (TDO) program. The objectives of the AGR-2 experiment are to: 1. Irradiate UCO (uranium oxycarbide) and UO2 (uranium dioxide) fuel produced in a large coater. Fuel attributes are based on results obtained from the AGR-1 test and other project activities. 2. Provide irradiated fuel samples for post-irradiation experiment (PIE) and safety testing. 3. Support the development of an understanding of the relationship between fuel fabrication processes, fuel product properties, and irradiation performance. The primary objective of the test was to irradiate both UCO and UO2 TRISO (tristructural isotropic) fuel produced from prototypic scale equipment to obtain normal operation and accident condition fuel performance data. The UCO compacts were subjected to a range of burnups and temperatures typical of anticipated prismatic reactor service conditions in three capsules. The test train also includes compacts containing UO2 particles produced independently by the United States, South Africa, and France in three separate capsules. The range of burnups and temperatures in these capsules were typical of anticipated pebble bed reactor service conditions. The results discussed in this report pertain only to U.S.-produced fuel.

  4. AGR-2 Irradiation Test Final As-Run Report

    Energy Technology Data Exchange (ETDEWEB)

    Collin, Blaise P. [Idaho National Lab. (INL), Idaho Falls, ID (United States). VHTR Program

    2014-08-01

    This document presents the as-run analysis of the AGR-2 irradiation experiment. AGR-2 is the second of the planned irradiations for the Advanced Gas Reactor (AGR) Fuel Development and Qualification Program. Funding for this program is provided by the U.S. Department of Energy as part of the Very High Temperature Reactor (VHTR) Technical Development Office (TDO) program. The objectives of the AGR-2 experiment are to: (a) Irradiate UCO (uranium oxycarbide) and UO2 (uranium dioxide) fuel produced in a large coater. Fuel attributes are based on results obtained from the AGR-1 test and other project activities. (b) Provide irradiated fuel samples for post-irradiation experiment (PIE) and safety testing. (c) Support the development of an understanding of the relationship between fuel fabrication processes, fuel product properties, and irradiation performance. The primary objective of the test was to irradiate both UCO and UO2 TRISO (tri-structural isotropic) fuel produced from prototypic scale equipment to obtain normal operation and accident condition fuel performance data. The UCO compacts were subjected to a range of burnups and temperatures typical of anticipated prismatic reactor service conditions in three capsules. The test train also includes compacts containing UO2 particles produced independently by the United States, South Africa, and France in three separate capsules. The range of burnups and temperatures in these capsules were typical of anticipated pebble bed reactor service conditions. The results discussed in this report pertain only to U.S. produced fuel.

  5. Emission of fission products and other activities during the accident to Windscale Pile no. 1 in October 1957

    International Nuclear Information System (INIS)

    Information on the release of activity from Windscale during the accident of October 1957 is reviewed, and some previously unpublished data are given. The activities of 131I released to atmosphere, retained on the pile filters and washed out of the pile are compared with the activity in the channels involved in the fire. The information on the physical form of the released activity is summarised. (author)

  6. The 1977-1979 geological and hydrogeological investigations at the Windscale Works, Sellafield, Cumbria

    International Nuclear Information System (INIS)

    In late 1976 an investigation was initiated to examine the geological and hydrogeological conditions beneath the Windscale Works, Sellafield, which is owned by British Nuclear Fuels Ltd. Sixty-two boreholes have been drilled, forming a grid of monitoring points. The geological succession comprises predominantly a sequence of gravels, sands, silts and clays which are very variable in thickness and lithology and which are overlain by up to 3m of Made Ground. These unconsolidated deposits of glacial and fluvioglacial origin overlie a fine-grained, well cemented Triassic sandstone, the St Bees Sandstone. The surface of the sandstone incorporates a channel which runs westwards across the site. The unconsolidated glacial deposits contain two types of groundwater bodies. Perched groundwater occurs in several areas but the main occurrence is in the deposits underlying the entire site at depths of between 3 and 15m below ground level. In the central section an extensive silty sand deposit divides the main groundwater body into an upper and lower aquifer. Water levels in the upper aquifer are at greater elevations than those in the lower. The St Bees Sandstone also contains groundwater which appears to be in hydraulic continuity with that in the glacial deposits. Groundwater flow in the main glacial and sandstone aquifers is westwards towards the coast. However the flow directions are complicated by two groundwater recharge mounds, one of natural origin and one which may be of partly artificial origin resulting from the industrialisation of the site. (author)

  7. Free release waste characterisation during the decommissioning of windscale Pile 2 Chimney

    Energy Technology Data Exchange (ETDEWEB)

    Frith, A.J. [NIRAS (United Kingdom); Dickson, E.D.; Hewetson, J.A.; McCormick, K. [BNFL (United Kingdom)

    2003-07-01

    The decommissioning of windscale Pile 2 Chimney resulted in the removal of one of most historically significant and prominent features of the Sellafield site. The project was the first large scale concrete ''free release'' operation to be undertaken on the Sellafield nuclear site, producing 4500 tons of concrete of which 3000 tons was demonstrated to be ''free release''. The paper describes the radiometric techniques employed in the characterisation and segregation of the concrete into low level waste (LLW), very low level waste (VLLW) and free release categories. It examines the robust solutions that were developed to meet the technical and regulatory challenges of the project, which included the definition of free release, the selection of averaging volumes, the testing and validation of the monitoring systems employed for ton quantities of concrete and the identification and removal of small numbers of fuel particles from the free release waste stream. As a result of interest shown by other BNFL and UKAEA decommissioning projects at Sellafield, the paper finishes by discussing ways in which the system may be developed to assay other waste streams. (orig.)

  8. AGR-2 IRRADIATION TEST FINAL AS-RUN REPORT

    Energy Technology Data Exchange (ETDEWEB)

    Blaise, Collin

    2014-07-01

    This document presents the as-run analysis of the AGR-2 irradiation experiment. AGR-2 is the second of the planned irradiations for the Advanced Gas Reactor (AGR) Fuel Development and Qualification Program. Funding for this program is provided by the U.S. Department of Energy as part of the Very High Temperature Reactor (VHTR) Technical Development Office (TDO) program. The objectives of the AGR-2 experiment are to: (a) Irradiate UCO (uranium oxycarbide) and UO2 (uranium dioxide) fuel produced in a large coater. Fuel attributes are based on results obtained from the AGR-1 test and other project activities. (b) Provide irradiated fuel samples for post-irradiation experiment (PIE) and safety testing. (c) Support the development of an understanding of the relationship between fuel fabrication processes, fuel product properties, and irradiation performance. The primary objective of the test was to irradiate both UCO and UO2 TRISO (tri-structural isotropic) fuel produced from prototypic scale equipment to obtain normal operation and accident condition fuel performance data. The UCO compacts were subjected to a range of burnups and temperatures typical of anticipated prismatic reactor service conditions in three capsules. The test train also includes compacts containing UO2 particles produced independently by the United States, South Africa, and France in three separate capsules. The range of burnups and temperatures in these capsules were typical of anticipated pebble bed reactor service conditions. The results discussed in this report pertain only to U.S. produced fuel. In order to achieve the test objectives, the AGR-2 experiment was irradiated in the B-12 position of the Advanced Test Reactor (ATR) at Idaho National Laboratory (INL) for a total irradiation duration of 559.2 effective full power days (EFPD). Irradiation began on June 22, 2010, and ended on October 16, 2013, spanning 12 ATR power cycles and approximately three and a half calendar years. The test

  9. Safety Testing of AGR-2 UCO Compacts 5-2-2, 2-2-2, and 5-4-1

    Energy Technology Data Exchange (ETDEWEB)

    Hunn, John D [ORNL; Morris, Robert Noel [ORNL; Baldwin, Charles A [ORNL; Montgomery, Fred C [ORNL

    2016-10-01

    Post-irradiation examination (PIE) is being performed on tristructural-isotropic (TRISO) coated-particle fuel compacts from the Advanced Gas Reactor (AGR) Fuel Development and Qualification Program second irradiation experiment (AGR-2) [Collin 2014]. This effort builds upon the understanding acquired throughout the AGR-1 PIE campaign [Demkowicz et al. 2015a] and is establishing a database for the different AGR-2 fuel designs. The AGR-2 irradiation experiment included TRISO fuel particles coated at BWX Technologies (BWXT) with a 150-mm-diameter engineering-scale coater. Two coating batches were tested in the AGR-2 irradiation experiment. Batch 93085 had 508-μm-diameter uranium dioxide (UO2) kernels. Batch 93073 had 427-μm-diameter UCO kernels, which is a kernel design where some of the uranium oxide is converted to uranium carbide during fabrication to provide a getter for oxygen liberated during fission and limit CO production. Fabrication and property data for the AGR-2 coating batches have been compiled [Barnes and Marshall 2009] and compared to AGR-1 [Phillips, Barnes, and Hunn 2010]. The AGR-2 TRISO coatings were most like the AGR-1 Variant 3 TRISO deposited in the 50-mm-diameter ORNL lab-scale coater [Hunn and Lowden 2006]. In both cases argon-dilution of the hydrogen and methyltrichlorosilane coating gas mixture employed to deposit the SiC was used to produce a finer-grain, more equiaxed SiC microstructure [Lowden 2006; Gerczak et al. 2016]. In addition to the fact that AGR-1 fuel had smaller, 350-μm-diameter UCO kernels, notable differences in the TRISO particle properties included the pyrocarbon anisotropy, which was slightly higher in the particles coated in the engineeringscale coater, and the exposed kernel defect fraction, which was higher for AGR-2 fuel due to the detected presence of particles with impact damage introduced during TRISO particle handling [Hunn 2010].

  10. Safety Testing of AGR-2 UCO Compacts 5-2-2, 2-2-2, and 5-4-1

    Energy Technology Data Exchange (ETDEWEB)

    Hunn, John D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Fusion and Materials for Nuclear Systems Division; Morris, Robert Noel [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Fusion and Materials for Nuclear Systems Division; Baldwin, Charles A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Fusion and Materials for Nuclear Systems Division; Montgomery, Fred C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Fusion and Materials for Nuclear Systems Division

    2016-08-01

    Post-irradiation examination (PIE) is being performed on tristructural-isotropic (TRISO) coated-particle fuel compacts from the Advanced Gas Reactor (AGR) Fuel Development and Qualification Program second irradiation experiment (AGR-2) [Collin 2014]. This effort builds upon the understanding acquired throughout the AGR-1 PIE campaign [Demkowicz et al. 2015a] and is establishing a database for the different AGR-2 fuel designs. The AGR-2 irradiation experiment included TRISO fuel particles coated at BWX Technologies (BWXT) with a 150-mm-diameter engineering-scale coater. Two coating batches were tested in the AGR-2 irradiation experiment. Batch 93085 had 508-μm-diameter uranium dioxide (UO2) kernels. Batch 93073 had 427-μm-diameter UCO kernels, which is a kernel design where some of the uranium oxide is converted to uranium carbide during fabrication to provide a getter for oxygen liberated during fission and limit CO production. Fabrication and property data for the AGR-2 coating batches have been compiled [Barnes and Marshall 2009] and compared to AGR-1 [Phillips, Barnes, and Hunn 2010]. The AGR-2 TRISO coatings were most like the AGR-1 Variant 3 TRISO deposited in the 50-mm-diameter ORNL lab-scale coater [Hunn and Lowden 2006]. In both cases argon-dilution of the hydrogen and methyltrichlorosilane coating gas mixture employed to deposit the SiC was used to produce a finer-grain, more equiaxed SiC microstructure [Lowden 2006; Gerczak et al. 2016]. In addition to the fact that AGR-1 fuel had smaller, 350-μm-diameter UCO kernels, notable differences in the TRISO particle properties included the pyrocarbon anisotropy, which was slightly higher in the particles coated in the engineeringscale coater, and the exposed kernel defect fraction, which was higher for AGR-2 fuel due to the detected presence of particles with impact damage introduced during TRISO particle handling [Hunn 2010].

  11. AGR-2 safety test predictions using the PARFUME code

    Energy Technology Data Exchange (ETDEWEB)

    Collin, Blaise P. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2014-09-01

    This report documents calculations performed to predict failure probability of TRISO-coated fuel particles and diffusion of fission products through these particles during safety tests following the second irradiation test of the Advanced Gas Reactor program (AGR-2). The calculations include the modeling of the AGR-2 irradiation that occurred from June 2010 to October 2013 in the Advanced Test Reactor (ATR) and the modeling of a safety testing phase to support safety tests planned at Oak Ridge National Laboratory and at Idaho National Laboratory (INL) for a selection of AGR-2 compacts. The heat-up of AGR-2 compacts is a critical component of the AGR-2 fuel performance evaluation, and its objectives are to identify the effect of accident test temperature, burnup, and irradiation temperature on the performance of the fuel at elevated temperature. Safety testing of compacts will be followed by detailed examinations of the fuel particles to further evaluate fission product retention and behavior of the kernel and coatings. The modeling was performed using the particle fuel model computer code PARFUME developed at INL. PARFUME is an advanced gas-cooled reactor fuel performance modeling and analysis code (Miller 2009). It has been developed as an integrated mechanistic code that evaluates the thermal, mechanical, and physico-chemical behavior of fuel particles during irradiation to determine the failure probability of a population of fuel particles given the particle-to-particle statistical variations in physical dimensions and material properties that arise from the fuel fabrication process, accounting for all viable mechanisms that can lead to particle failure. The code also determines the diffusion of fission products from the fuel through the particle coating layers, and through the fuel matrix to the coolant boundary. The subsequent release of fission products is calculated at the compact level (release of fission products from the compact). PARFUME calculates the

  12. Evidence to the Windscale Inquiry on the safety assessment of nuclear fuel reprocessing storage and ancillary activities

    International Nuclear Information System (INIS)

    The evidence falls under the following headings: proof of evidence - part 1; description of witness; nature of evidence; need for a safety analysis; general form of a safety analysis; THORP safety analysis; safety information provided to the inquiry; why has complete information not been provided (query); who should conduct the safety analysis (query); conclusions; proof of evidence - part 2; nature of this further evidence (details of some accident sequences and their consequences are presented for Windscale); hazard areas considered for accidents; HAW (high-active waste) tank release; SFS (spent fuel storage) pond release; determination of consequences; conclusions. (U.K.)

  13. SiC layer microstructure in AGR-1 and AGR-2 TRISO fuel particles and the influence of its variation on the effective diffusion of key fission products

    Science.gov (United States)

    Gerczak, Tyler J.; Hunn, John D.; Lowden, Richard A.; Allen, Todd R.

    2016-11-01

    Tristructural isotropic (TRISO) coated particle fuel is a promising fuel form for advanced reactor concepts such as high temperature gas-cooled reactors (HTGR) and is being developed domestically under the US Department of Energy's Nuclear Reactor Technologies Initiative in support of Advanced Reactor Technologies. The fuel development and qualification plan includes a series of fuel irradiations to demonstrate fuel performance from the laboratory to commercial scale. The first irradiation campaign, AGR-1, included four separate TRISO fuel variants composed of multiple, laboratory-scale coater batches. The second irradiation campaign, AGR-2, included TRISO fuel particles fabricated by BWX Technologies with a larger coater representative of an industrial-scale system. The SiC layers of as-fabricated particles from the AGR-1 and AGR-2 irradiation campaigns have been investigated by electron backscatter diffraction (EBSD) to provide key information about the microstructural features relevant to fuel performance. The results of a comprehensive study of multiple particles from all constituent batches are reported. The observations indicate that there were microstructural differences between variants and among constituent batches in a single variant. Insights on the influence of microstructure on the effective diffusivity of key fission products in the SiC layer are also discussed.

  14. Seminar on Comparative assessment of the environmental impact of radionuclides released during three major nuclear accidents: Kyshtym, Windscale, Chernobyl. Vol. 1

    International Nuclear Information System (INIS)

    These proceedings of seminar on comparative assessment of the environmental impact of radionuclides released during three major nuclear accidents (Kyshtym, Windscale, Chernobyl) are divided into 5 parts bearing on: part 1: accident source terms; part 2: atmospheric dispersion, resuspension, chemical and physical forms of contamination; part 3: environmental contamination and transfer; part 4: radiological implications for man and his environment; part 5: countermeasures

  15. Plant Measurement, Sampling and Analysis for Accountancy Purposes with Particular Reference to Separation Plants at Windscale

    International Nuclear Information System (INIS)

    All figures for special materials accountancy purposes contain one or more of three parameters, namely plant measurement, sampling and analysis. For plant measurements it is best to use weighings wherever possible, e.g. the plutonium in the feed to the New Separation Plant is based on the weight of uranium rods fed. Methods used for measuring volumes are discussed, e.g. (a) pneumercator, and (b) tracer method using radioactive caesium. Judged accuracies and precisions of each method are given. The sampling of solutions in a batch process is done by using evacuated tubes after thorough homogenization of the solution. For ''flowing'' streams, where high accuracy is required, a continuous sampler has been devised and is used on the feed to the New Separation Plant. Drilling of metal ingots is the normal sampling method at Windscale, whereas for other solids the method is to homogenize as far as possible (e.g. a Y cone blender is used for plutonium oxide) and then sample. For the chemical analysis, the precision required of the method depends on the number of determinations in each accounting period. Thus a large number of analyses are required for an accurate but imprecise method. It may be more economical to use fewer determinations with a more precise method. Methods for determining plutonium are discussed in detail, e.g. (a) radiochemistry, (b) colorimetrically using thoronol, (c) plutonium separation, complexing with EDTA and back titration of the excess EDTA, (d) titrimetry (e) isotope dilution followed by mass spectrometry and (f) differential spectrometry. Methods for determining uranium are outlined, e.g. (a) gravimetry as U3O8, (b) ether extraction followed by gravimetry or colorimetry, (c) titrimetry, (d) isotope dilution followed by mass spectrometry and (e) enrichment determination by mass spectrometry or line shift emission spectrography. With all accounting methods standards are used to give quality control and to show any inaccuracy which requires to be

  16. Data Compilation for AGR-1 Variant 3 Compact Lot LEU01-49T-Z

    Energy Technology Data Exchange (ETDEWEB)

    Hunn, John D [ORNL; Montgomery, Fred C [ORNL; Pappano, Peter J [ORNL

    2006-08-01

    This document is a compilation of characterization data for the AGR-1 vriant 3 fuel compact lot LEU01-49T-Z. The compacts were produced by ORNL for the Advanced Gas Reactor Fuel Development and Qualification (AGR) program for the first AGR irradiation test train (AGR-1). This compact lot was fabricated using particle composite LEU01-49T, which was a composite of three batches of TRISO-coated 350 {micro}m diameter 19.7% low enrichment uranium oxide/uranium carbide kernels (LEUCO). The AGR-1 TRISO-coated particles consist of a spherical kernel coated with an {approx} 50% dense carbon buffer layer (100 {micro}m nominal thickness), followed by a dense inner pyrocarbon layer (40 {micro}m nominal thickness), followed by a SiC layer (35 {micro}m nominal thickness), followed by another dense outer pyrocarbon layer (40 {micro}m nominal thickness). The kernels were obtained from BWXT and identified as composite G73D-20-69302. The BWXT kernel lot G73D-20-69302 was riffled into sublots for characterization and coating by ORNL and identified as LEU01-?? (where ?? is a series of integers beginning with 01). A data compilation for the AGR-1 variant 3 coated particle composite LEU01-49t CAN BE FOUND IN ornl/tm-2006/022.

  17. AGR-1 Irradiation Test Final As-Run Report

    Energy Technology Data Exchange (ETDEWEB)

    Blaise P. Collin

    2012-06-01

    This document presents the as-run analysis of the AGR-1 irradiation experiment. AGR-1 is the first of eight planned irradiations for the Advanced Gas Reactor (AGR) Fuel Development and Qualification Program. Funding for this program is provided by the US Department of Energy (DOE) as part of the Next-Generation Nuclear Plant (NGNP) project. The objectives of the AGR-1 experiment are: 1. To gain experience with multi-capsule test train design, fabrication, and operation with the intent to reduce the probability of capsule or test train failure in subsequent irradiation tests. 2. To irradiate fuel produced in conjunction with the AGR fuel process development effort. 3. To provide data that will support the development of an understanding of the relationship between fuel fabrication processes, fuel product properties, and irradiation performance. In order to achieve the test objectives, the AGR-1 experiment was irradiated in the B-10 position of the Advanced Test Reactor (ATR) at the Idaho National Laboratory (INL) for a total duration of 620 effective full power days of irradiation. Irradiation began on December 24, 2006 and ended on November 6, 2009 spanning 13 ATR cycles and approximately three calendar years. The test contained six independently controlled and monitored capsules. Each capsule contained 12 compacts of a single type, or variant, of the AGR coated fuel. No fuel particles failed during the AGR-1 irradiation. Final burnup values on a per compact basis ranged from 11.5 to 19.6 %FIMA, while fast fluence values ranged from 2.21 to 4.39 ?1025 n/m2 (E >0.18 MeV). We’ll say something here about temperatures once thermal recalc is done. Thermocouples performed well, failing at a lower rate than expected. At the end of the irradiation, nine of the originally-planned 19 TCs were considered functional. Fission product release-to-birth (R/B) ratios were quite low. In most capsules, R/B values at the end of the irradiation were at or below 10-7 with only one

  18. PIE on Safety-Tested AGR-1 Compact 5-1-1

    Energy Technology Data Exchange (ETDEWEB)

    Hunn, John D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Morris, Robert Noel [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Baldwin, Charles A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Montgomery, Fred C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Gerczak, Tyler J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-08-01

    Post-irradiation examination (PIE) is being performed in support of tristructural isotropic (TRISO) coated particle fuel development and qualification for High-Temperature Gas-cooled Reactors (HTGRs). AGR-1 was the first in a series of TRISO fuel irradiation experiments initiated in 2006 under the Advanced Gas Reactor (AGR) Fuel Development and Qualification Program; this work continues to be funded by the Department of Energy's Office of Nuclear Energy as part of the Advanced Reactor Technologies (ART) initiative. AGR-1 fuel compacts were fabricated at Oak Ridge National Laboratory (ORNL) in 2006 and irradiated for three years in the Idaho National Laboratory (INL) Advanced Test Reactor (ATR) to demonstrate and evaluate fuel performance under HTGR irradiation conditions. PIE is being performed at INL and ORNL to study how the fuel behaved during irradiation, and to examine fuel performance during exposure to elevated temperatures at or above temperatures that could occur during a depressurized conduction cooldown event. This report summarizes safety testing of irradiated AGR-1 Compact 5-1-1 in the ORNL Core Conduction Cooldown Test Facility (CCCTF) and post-safety testing PIE.

  19. AGR 3/4 Irradiation Test Final As Run Report

    Energy Technology Data Exchange (ETDEWEB)

    Collin, Blaise P. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-06-01

    Several fuel and material irradiation experiments have been planned for the Idaho National Laboratory Advanced Reactor Technologies Technology Development Office Advanced Gas Reactor Fuel Development and Qualification Program (referred to as the INL ART TDO/AGR fuel program hereafter), which supports the development and qualification of tristructural-isotropic (TRISO) coated particle fuel for use in HTGRs. The goals of these experiments are to provide irradiation performance data to support fuel process development, qualify fuel for normal operating conditions, support development and validation of fuel performance and fission product transport models and codes, and provide irradiated fuel and materials for post irradiation examination and safety testing (INL 05/2015). AGR-3/4 combined the third and fourth in this series of planned experiments to test TRISO coated low enriched uranium (LEU) oxycarbide fuel. This combined experiment was intended to support the refinement of fission product transport models and to assess the effects of sweep gas impurities on fuel performance and fission product transport by irradiating designed-to-fail fuel particles and by measuring subsequent fission metal transport in fuel-compact matrix material and fuel-element graphite. The AGR 3/4 fuel test was successful in irradiating the fuel compacts to the burnup and fast fluence target ranges, considering the experiment was terminated short of its initial 400 EFPD target (Collin 2015). Out of the 48 AGR-3/4 compacts, 42 achieved the specified burnup of at least 6% fissions per initial heavy-metal atom (FIMA). Three capsules had a maximum fuel compact average burnup < 10% FIMA, one more than originally specified, and the maximum fuel compact average burnup was <19% FIMA for the remaining capsules, as specified. Fast neutron fluence fell in the expected range of 1.0 to 5.5×1025 n/m2 (E >0.18 MeV) for all compacts. In addition, the AGR-3/4 experiment was globally successful in keeping the

  20. Uncertainty Quantification of Calculated Temperatures for the AGR 3/4 Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Pham, Binh Thi-Cam [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-09-01

    A series of Advanced Gas Reactor (AGR) irradiation experiments are being conducted within the Advanced Reactor Technology (ART) Fuel Development and Qualification Program. The main objectives of the fuel experimental campaign are to provide the necessary data on fuel performance to support fuel process development, qualify a fuel design and fabrication process for normal operation and accident conditions, and support development and validation of fuel performance and fission product transport models and codes (PLN 3636, “Technical Program Plan for INL Advanced Reactor Technologies Technology Development Office/Advanced Gas Reactor Fuel Development and Qualification Program”). The AGR 3/4 test was inserted in the Northeast Flux Trap position in the Advanced Test Reactor (ATR) core at Idaho National Laboratory (INL) in December 2011 and successfully completed irradiation in mid-April 2014, resulting in irradiation of the tristructural isotropic (TRISO) fuel for 369.1 effective full-power days (EFPDs) during approximately 2.4 calendar years. The AGR 3/4 data, including the irradiation data and calculated results, were qualified and stored in the Nuclear Data Management and Analysis System (NDMAS). To support the U.S. TRISO fuel performance assessment and to provide data for validation of fuel performance and fission product transport models and codes, the daily as run thermal analysis has been performed separately on each of twelve AGR 3/4 capsules for the entire irradiation as discussed in ECAR-2807, “AGR 3/4 Daily As Run Thermal Analyses”. The ABAQUS code’s finite element-based thermal model predicts the daily average volume average (VA) fuel temperature (FT), peak FT, and graphite matrix, sleeve, and sink temperature in each capsule. The JMOCUP simulation codes were also created to perform depletion calculations for the AGR 3/4 experiment (ECAR-2753, “JMOCUP As-Run Daily Physics Depletion Calculation for the AGR 3/4 TRISO Particle Experiment in ATR

  1. Uncertainty Quantification of Calculated Temperatures for the AGR 3/4 Experiment

    International Nuclear Information System (INIS)

    A series of Advanced Gas Reactor (AGR) irradiation experiments are being conducted within the Advanced Reactor Technology (ART) Fuel Development and Qualification Program. The main objectives of the fuel experimental campaign are to provide the necessary data on fuel performance to support fuel process development, qualify a fuel design and fabrication process for normal operation and accident conditions, and support development and validation of fuel performance and fission product transport models and codes (PLN 3636, 'Technical Program Plan for INL Advanced Reactor Technologies Technology Development Office/Advanced Gas Reactor Fuel Development and Qualification Program'). The AGR 3/4 test was inserted in the Northeast Flux Trap position in the Advanced Test Reactor (ATR) core at Idaho National Laboratory (INL) in December 2011 and successfully completed irradiation in mid-April 2014, resulting in irradiation of the tristructural isotropic (TRISO) fuel for 369.1 effective full-power days (EFPDs) during approximately 2.4 calendar years. The AGR 3/4 data, including the irradiation data and calculated results, were qualified and stored in the Nuclear Data Management and Analysis System (NDMAS). To support the U.S. TRISO fuel performance assessment and to provide data for validation of fuel performance and fission product transport models and codes, the daily as run thermal analysis has been performed separately on each of twelve AGR 3/4 capsules for the entire irradiation as discussed in ECAR-2807, 'AGR 3/4 Daily As Run Thermal Analyses'. The ABAQUS code's finite element-based thermal model predicts the daily average volume average (VA) fuel temperature (FT), peak FT, and graphite matrix, sleeve, and sink temperature in each capsule. The JMOCUP simulation codes were also created to perform depletion calculations for the AGR 3/4 experiment (ECAR-2753, 'JMOCUP As-Run Daily Physics Depletion Calculation for the AGR 3/4 TRISO Particle

  2. AGR-2 Data Qualification Report for ATR Cycles 147A, 148A, 148B, and 149A

    Energy Technology Data Exchange (ETDEWEB)

    Michael L. Abbott; Keith A. Daum

    2011-08-01

    This report presents the data qualification status of fuel irradiation data from the first four reactor cycles (147A, 148A, 148B, and 149A) of the on-going second Advanced Gas Reactor (AGR-2) experiment as recorded in the NGNP Data Management and Analysis System (NDMAS). This includes data received by NDMAS from the period June 22, 2010 through May 21, 2011. AGR-2 is the second in a series of eight planned irradiation experiments for the AGR Fuel Development and Qualification Program, which supports development of the very high temperature gas-cooled reactor (VHTR) under the Next Generation Nuclear Plant (NGNP) Project. Irradiation of the AGR-2 test train is being performed at the Advanced Test Reactor (ATR) at the Idaho National Laboratory (INL) and is planned for 600 effective full power days (approximately 2.75 calendar years) (PLN-3798). The experiment is intended to demonstrate the performance of UCO (uranium oxycarbide) and UO2 (uranium dioxide) fuel produced in a large coater. Data qualification status of the AGR-1 experiment was reported in INL/EXT-10-17943 (Abbott et al. 2010).

  3. Quantity of 135I Released from the AGR 1, AGR 2, and AGR 3/4 Experiments and Discovery of 131I at the FPMS Traps during the AGR-3/4 Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Dawn Scates

    2014-09-01

    A series of three Advanced Gas Reactor (AGR) experiments have been conducted in the Advanced Test Reactor (ATR) at Idaho National Laboratory (INL). From 2006 through 2014, these experiments supported the development and qualification of the new U.S. tristructural isotropic (TRISO) particle fuel for Very High Temperature Reactors (VHTR). Each AGR experiment consisted of multiple fueled capsules, each plumbed for independent temperature control using a mix of helium and neon gases. The gas leaving a capsule was routed to individual Fission Product Monitor (FPM) detectors. For intact fuel particles, the TRISO particle coatings provide a substantial barrier to fission product release. However, particles with failed coatings, whether because of a minute percentage of initially defective particles, those which fail during irradiation, or those designed to fail (DTF) particles, can release fission products to the flowing gas stream. Because reactive fission product elements like iodine and cesium quickly deposit on cooler capsule components and piping structures as the effluent gas leaves the reactor core, only the noble fission gas isotopes of Kr and Xe tend to reach FPM detectors. The FPM system utilizes High Purity Germanium (HPGe) detectors coupled with a thallium activated sodium iodide NaI(Tl) scintillator. The HPGe detector provides individual isotopic information, while the NaI(Tl) scintillator is used as a gross count rate meter. During irradiation, the 135mXe concentration reaching the FPM detectors is from both direct fission and by decay of the accumulated 135I. About 2.5 hours after irradiation (ten 15.3 minute 135mXe half lives) the directly produced 135mXe has decayed and only the longer lived 135I remains as a source. Decay systematics dictate that 135mXe will be in secular equilibrium with its 135I parent, such that its production rate very nearly equals the decay rate of the parent, and its concentration in the flowing gas stream will appear to decay

  4. Data Compilation for AGR-1 Baseline Compact Lot LEU01-46T-Z

    Energy Technology Data Exchange (ETDEWEB)

    Hunn, John D [ORNL; Montgomery, Fred C [ORNL; Pappano, Peter J [ORNL

    2006-08-01

    This document is a compilation of characterization data for the AGR-1 baseline compact lot LEU01-46T-Z. The compacts were produced by ORNL for the Advanced Gas Reactor Fuel Development and Qualification (AGR) program for the first AGR irradiation test train (AGR-1). This compact lot was fabricated using particle composite LEU01-46T, which was a composite of four batches of TRISO-coated 350 {micro}m diameter 19.7% low enrichment uranium oxide/uranium carbide kernels (LEUCO). The AGR-1 TRISO-coated particles consist of a spherical kernel coated with an {approx} 50% dense carbon buffer layer (100 {micro}m nominal thickness), followed by a dense inner pyrocarbon layer (40 {micro}m nominal thickness), followed by a SiC layer (35 {micro}m nominal thickness), followed by another dense outer pyrocarbon layer (40 {micro}m nominal thickness). The kernels were obtained from BWXT and identified as composite G73D-20-69302. The BWXT kernel lot G73D-20-69302 was riffled into sublots for characterization and coating by ORNL and identified as LEU01-?? (where ?? is a series of integers beginning with 01). A data compilation for the AGR-1 baseline coated particle composite LEU01-46T can be found in ORNL/TM-2006/019. The AGR-1 Fuel product Specification and Characterization Guidance (INL EDF-4380) provides the requirements necessary for acceptance of the fuel manufactured for the AGR-1 irradiation test. Section 6.2 of EDF-4380 provides the property requirements for the heat treated compacts. The Statistical Sampling Plan for AGR Fuel materials (INL EDF-4542) provides additional guidance regarding statistical methods for product acceptance and recommended sample sizes. The procedures for characterizing and qualifying the compacts are outlined in ORNL product inspection plan AGR-CHAR-PIP-05. the inspection report forms generated by this product inspection plan document the product acceptance for the property requirements listed in section 6.2 of EDF-4380.

  5. Data Compilation for AGR-1 Variant 2 Compact Lot LEU01-48T-Z

    Energy Technology Data Exchange (ETDEWEB)

    Hunn, John D [ORNL; Montgomery, Fred C [ORNL; Pappano, Peter J [ORNL

    2006-08-01

    This document is a compilation of characterization data for the AGR-1 variant 2 compact lot LEU01-48T-Z. The compacts were produced by ORNL for the Advanced Gas Reactor Fuel Development and Qualification (AGR) program for the first AGR irradiation test train (AGR-1). This compact lot was fabricated using particle composite LEU01-48T, which was a composite of three batches of TRISO-coated 350 {micro}m diameter 19.7% low enrichment uranium oxide/uranium carbide kernels (LEUCO). The AGR-1 TRISO-coated particles consist of a spherical kernel coated with an {approx} 50% dense carbon buffer layer (100 {micro}m nominal thickness), followed by a dense inner pyrocarbon layer (40 {micro}m nominal thickness), followed by a SiC layer (35 {micro}m nominal thickness), followed by another dense outer pyrocarbon layer (40 {micro}m nominal thickness). The kernels were obtained from BWXT and identified as composite G73D-20-69302. The BWXT kernel lot G73D-20-69302 was riffled into sublots for characterization and coating by ORNL and identified as LEU01-?? (where ?? is a series of integers beginning with 01). A data compilation for the AGR-1 variant 2 coated particle composite LEU01-48T can be found in ORNL/TM-2006/021. The AGR-1 Fuel Product Specification and Characterization Guidance (INL EDF-4380) provides the requirements necessary for acceptance of the fuel manufactured for the AGR-1 irradiation test. Section 6.2 of EDF-4380 provides the property requirements for the heat treated compacts. The Statistical Sampling Plan for AGR Fuel materials (INL EDF-4542) provides additional guidance regarding statistical methods for product acceptance and recommended sample sizes. The procedures for characterizing and qualifying the compacts are outlined in ORNL product inspection plan AGR-CHAR-PIP-05. The inspection report forms generated by this product inspection plan document the product acceptance for the property requirements listed in section 6.2 of EDF-4380.

  6. Data Compilation for AGR-1 Variant 1 Compact Lot LEU01-47T-Z

    Energy Technology Data Exchange (ETDEWEB)

    Hunn, John D [ORNL; Montgomery, Fred C [ORNL; Pappano, Peter J [ORNL

    2006-08-01

    This document is a compilation of characterization data for the AGR-1 variant 1 compact lot LEU01-47T-Z. The compacts were produced by ORNL for the ADvanced Gas Reactor Fuel Development and Qualification (AGR) program for the first AGR irradiation test train (AGR-1). This compact lot was fabricated using particle composite LEU01-47T, which was a composite of three batches of TRISO-coated 350 {micro}m diameter 19.7% low enrichment uranium oxide/uranium carbide kernels (LEUCO). The AGR-1 TRISO-coated particles consist of a spherical kernel coated with an {approx} 50% dense carbon buffer layer (100 {micro}m nominal thickness), followed by a dense inner pyrocarbon layer (40 {micro}m nominal thickness), followed by a SiC layer (35 {micro}m nominal thickness), followed by another dense outer pyrcoarbon layer (40 {micro}m nominal thickness). The kernels were obtained from BWXT and identified as composite G73D-20-69302. The BWXT kernel lot G73D-20-69302 was riffled into sublots for characterization and coating by ORNL and identified at LEU01-?? (where ?? is a series of integers beginning with 01). A data compilation for the AGR-1 variant 1 coated particle composite LEU01-47T can be found in ORNL/TM-2006/020. The AGR-1 Fuel Product Specification and Characterization Guidance (INL EDF-4380) provides the requirements necessary for acceptance of the fuel manufactured for the AGR-1 irradiation test. Section 6.2 of EDF-4380 provides the property requirements for the heat treated compacts. The Statistical Sampling Plan for AGR Fuel Materials (INL EDF-4542) provides additional guidance regarding statistical methods for product acceptance and recommended sample sizes. The procedures for characterizing and qualifying the compacts are outlined in ORNL product inspection plan AGR-CHAR-PIP-05. The inspection report forms generated by this product inspection plan document the product acceptance for the property requirements listed in section 6.2 of EDF-4380.

  7. ecotecnia agrícola

    Directory of Open Access Journals (Sweden)

    S. Orozco Cirilo

    2008-01-01

    Full Text Available Las Escuelas de Campo (EC son un método de extensión participativo que permite desarrollar capacidades analíticas, pensamiento crítico y, creatividad. La investigación se realizó en la región Mazateca de Oaxaca, la cual se caracteriza por su alto rezago tecnológico, porque resulta de relevancia científica, social y ecológica conocer, en este contexto, los alcances de metodologías alternativas de extensionismo sobre la adopción de ecotecniasagrícolas. Nuestro objetivo fue conocer la influencia del conocimiento otorgado en EC sobre el índice de adopción final de ecotecnia generada localmente, como alternativa a la enorme dependencia tecnológica. Las variables analizadas fueron: índice de adopción inicial, nivel inicial de conocimientos, número de cursos otorgados en EC, índice de adopción final y, nivel final de conocimientos. A una muestra de dos estratos participantes y un grupo testigo, fueron aplicados 135 cuestionarios. Para probar nuestras hipótesis los resultados de éstos se sometieron al análisis de varianza y correlación. Encontramos que solamente el índice de adopción final obtenido por los participantes experimentó incrementos estadísticamente significativos respecto a la condición inicial, debido a su participación en EC y al consecuente aumento en el conocimiento de la ecotecnia. Esto implica que la metodología propuesta incrementa la adopción de ecotecnias generadas localmente, consolidándose como un paradigmaalternativo en extensión agrícola.

  8. AGR-5/6/7 LEUCO Kernel Fabrication Readiness Review

    Energy Technology Data Exchange (ETDEWEB)

    Marshall, Douglas W. [Idaho National Lab. (INL), Idaho Falls, ID (United States). Fuel Design and Development; Bailey, Kirk W. [Idaho National Lab. (INL), Idaho Falls, ID (United States). ART Quality Assurance Engineer

    2015-02-01

    In preparation for forming low-enriched uranium carbide/oxide (LEUCO) fuel kernels for the Advanced Gas Reactor (AGR) fuel development and qualification program, Idaho National Laboratory conducted an operational readiness review of the Babcock & Wilcox Nuclear Operations Group – Lynchburg (B&W NOG-L) procedures, processes, and equipment from January 14 – January 16, 2015. The readiness review focused on requirements taken from the American Society Mechanical Engineers (ASME) Nuclear Quality Assurance Standard (NQA-1-2008, 1a-2009), a recent occurrence at the B&W NOG-L facility related to preparation of acid-deficient uranyl nitrate solution (ADUN), and a relook at concerns noted in a previous review. Topic areas open for the review were communicated to B&W NOG-L in advance of the on-site visit to facilitate the collection of objective evidences attesting to the state of readiness.

  9. Mortality and cancer registration experience of the Sellafield workers known to have been involved in the 1957 Windscale accident: 50 year follow-up

    Energy Technology Data Exchange (ETDEWEB)

    McGeoghegan, D; Whaley, S; Binks, K; Gillies, M; Thompson, K; McElvenny, D M, E-mail: Steve.Whaley@westlakes.ac.u [Epidemiology Group, Westlakes Research Institute, Westlakes Science and Technology Park, Moor Row, Cumbria CA24 3LN (United Kingdom)

    2010-09-15

    This paper studies the mortality and cancer morbidity of the 470 male workers involved in tackling the 1957 Sellafield Windscale fire or its subsequent clean-up. Workers were followed up for 50 years to 2007, extending the follow-up of a previously published cohort study on the Windscale fire by 10 years. The size of the study population is small, but the cohort is of interest because of the involvement of the workers in the accident. Significant excesses of deaths from diseases of the circulatory system (standardised mortality ratio (SMR) = 120, 95% CI = 103-138; 194 deaths) driven by ischaemic heart disease (IHD) (SMR = 133, 95% CI = 112-157, 141 deaths) were found when compared with the population of England and Wales but not when compared with the population of Northwest England (SMR = 105, 95% CI = 90-120 and SMR = 115, 95% CI = 97-136 respectively). When compared with those workers in post at the time of the fire but not directly involved in the fire the mortality rate from IHD among those involved in tackling the fire was raised but not statistically significantly (rate ratio (RR) = 1.11, 95% CI = 0.92-1.33). A RR of 1.11 is consistent with an excess relative risk of 0.65 Sv{sup -1} as reported in an earlier study of non-cancer mortality in the British Nuclear Fuels plc cohort of which these workers are a small but significant part. There was a statistically significant difference in lung cancer mortality (RR = 2.18, 95% CI = 1.05-4.52) rates between workers who had received higher recorded external doses during the fire and those who had received lower external doses. Comparison of the mortality rates of workers directly involved in the accident with workers in post, but not so involved, showed no significant differences overall. On the basis of the use of a propensity score the average effect of involvement in the Windscale fire on all causes of death was - 2.13% (se = 3.64%, p = 0.56) though this difference is not statistically significant. The average

  10. 15 CFR 740.18 - Agricultural commodities (AGR).

    Science.gov (United States)

    2010-01-01

    ... 15 Commerce and Foreign Trade 2 2010-01-01 2010-01-01 false Agricultural commodities (AGR). 740.18... EXCEPTIONS § 740.18 Agricultural commodities (AGR). (a) Eligibility requirements. License Exception AGR permits the export of agricultural commodities to Cuba, as well as the reexport of U.S....

  11. AGR-3/4 Final Data Qualification Report for ATR Cycles 151A through 155B-1

    Energy Technology Data Exchange (ETDEWEB)

    Pham, Binh T. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-03-01

    This report provides the qualification status of experimental data for the entire Advanced Gas Reactor 3/4 (AGR 3/4) fuel irradiation. AGR-3/4 is the third in a series of planned irradiation experiments conducted in the Advanced Test Reactor (ATR) at Idaho National Laboratory (INL) for the AGR Fuel Development and Qualification Program, which supports development of the advanced reactor technology under the INL ART Technology Development Office (TDO). The main objective of AGR-3/4 irradiation is to provide a known source of fission products for subsequent transport through compact matrix and structural graphite materials due to the presence of designed-to-fail fuel particles. Full power irradiation of the AGR 3/4 test began on December 14, 2011 (ATR Cycle 151A), and was completed on April 12, 2014 (end of ATR Cycle 155B) after 369.1 effective full power days of irradiation. The AGR-3/4 test was in the reactor core for eight of the ten ATR cycles between 151A and 155B. During the unplanned outage cycle, 153A, the experiment was removed from the ATR northeast flux trap (NEFT) location and stored in the ATR canal. This was to prevent overheating of fuel compacts due to higher than normal ATR power during the subsequent Powered Axial Locator Mechanism cycle, 153B. The AGR 3/4 test was inserted back into the ATR NEFT location during the outage of ATR Cycle 154A on April 26, 2013. Therefore, the AGR-3/4 irradiation data received during these 2 cycles (153A and 153B) are irrelevant and their qualification status isnot included in this report. Additionally, during ATR Cycle 152A the ATR core ran at low power for a short enough duration that the irradiation data are not used for physics and thermal calculations. However, the qualification status of irradiation data for this cycle is still covered in this report. As a result, this report includes data from 8 ATR Cycles: 151A, 151B, 152A, 152B, 154A, 154B, 155A, and 155B, as recorded in the Nuclear Data Management and

  12. Estudio de Salud Agrícola

    Science.gov (United States)

    En 1993, científicos del Instituto Nacional del Cáncer, Instituto Nacional de Ciencias Ambientales y la Agencia de Protección Ambiental de Estados Unidos iniciaron un estudio conocido como Estudio de Salud Agrícola (AHS).

  13. Mortality and cancer registration experience of the Sellafield employees known to have been involved in the 1957 Windscale accident

    International Nuclear Information System (INIS)

    The mortality and cancer morbidity experience of the 470 male Sellafield employees known to be involved in the 1957 Windscale accident is reported. All these employees are known to have been involved in dealing with the fire itself, or in the clean-up operation afterwards. The size of the study population is small, leading to predicted low power to reveal any effects, but the cohort is of interest because of the involvement of the workers in the accident. For 1957-97, using rates for England and Wales to calculate the expected numbers, the all causes standardised mortality ratio (SMR) is 100 (observed=258, expected=258.80), and the all malignant neoplasms SMR is 79 (observed=58, expected=73.12) which is not significantly different from 100. For 1971-91, the all malignant neoplasms standardised registration ratio (SRR) of 85 (observed=59, expected=69.23) is not significantly different from 100. Significant excesses of deaths from diseases of the circulatory system (SMR=121) and from ischaemic heart disease (SMR=128), and a significant deficit of deaths from cancer of the genito-urinary organs (SMR=31), were found. There were no significant differences in mortality rates between workers who had received high recorded external doses during the fire and those who had received low doses, though the power of this comparison was low. Comparison of the mortality rates of workers directly involved in the accident with workers in post, but not so involved, showed no significant differences. This study has been unable to detect any effect of the 1957 fire upon the mortality and cancer morbidity experience of those workers involved in it. (author)

  14. Windscale nuclear power development laboratories power ramp experience in the Winfrith SGHWR (UK)

    International Nuclear Information System (INIS)

    SGHWR fuel has sufficient power ramping capability to permit considerable latitude in fuel management schemes. However, beyond some limiting ramping conditions, there is risk of fuel defecting. Controlled ramp experiments were therefore carried out in the reactor in order to determine the defect mechanism and define the fuel operating limitations. Cladding cracks produced during these power ramps are considered to have been a consequence of fission product stress-corrosion attack. A critical stress level for cracking, based on laboratory stress corrosion tests, have been used successfully in conjunction with computer codes to calculate cladding stresses and strains in fuel rods. Initial analysis of the conditions under which a fuel element defected at 11.6 MWd/kgU suggests that the threshold stress for failure may be decreased compared with elements at lower burn-up (5-6 MWd/kgU)

  15. AGR-2 Irradiation Test Final As-Run Report, Rev 2

    Energy Technology Data Exchange (ETDEWEB)

    Collin, Blaise P. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2014-08-01

    This document presents the as-run analysis of the AGR-2 irradiation experiment. AGR-2 is the second of the planned irradiations for the Advanced Gas Reactor (AGR) Fuel Development and Qualification Program. Funding for this program is provided by the U.S. Department of Energy as part of the Very High Temperature Reactor (VHTR) Technical Development Office (TDO) program. The objectives of the AGR-2 experiment are to: (a) Irradiate UCO (uranium oxycarbide) and UO2 (uranium dioxide) fuel produced in a large coater. Fuel attributes are based on results obtained from the AGR-1 test and other project activities. (b) Provide irradiated fuel samples for post-irradiation experiment (PIE) and safety testing. (c) Support the development of an understanding of the relationship between fuel fabrication processes, fuel product properties, and irradiation performance. The primary objective of the test was to irradiate both UCO and UO2 TRISO (tri-structural isotropic) fuel produced from prototypic scale equipment to obtain normal operation and accident condition fuel performance data. The UCO compacts were subjected to a range of burnups and temperatures typical of anticipated prismatic reactor service conditions in three capsules. The test train also includes compacts containing UO2 particles produced independently by the United States, South Africa, and France in three separate capsules. The range of burnups and temperatures in these capsules were typical of anticipated pebble bed reactor service conditions. The results discussed in this report pertain only to U.S. produced fuel. In order to achieve the test objectives, the AGR-2 experiment was irradiated in the B-12 position of the Advanced Test Reactor (ATR) at Idaho National Laboratory (INL) for a total irradiation duration of 559.2 effective full power days (EFPD). Irradiation began on June 22, 2010, and ended on October 16, 2013, spanning 12 ATR power cycles and approximately three and a

  16. Large packages for reactor decommissioning waste

    International Nuclear Information System (INIS)

    This study was carried out jointly by the Atomic Energy Establishment at Winfrith (now called the Winfrith Technology Centre), Windscale Laboratory and Ove Arup and Partners. The work involved the investigation of the design of large transport containers for intermediate level reactor decommissioning waste, ie waste which requires shielding, and is aimed at European requirements (ie for both LWR and gas cooled reactors). It proposes a design methodology for such containers covering the whole lifetime of a waste disposal package. The design methodology presented takes account of various relevant constraints. Both large self shielded and returnable shielded concepts were developed. The work was generic, rather than specific; the results obtained, and the lessons learned, remain to be applied in practice

  17. Gas Reactor International Cooperative Program. Interim report. Construction and operating experience of selected European Gas-Cooled Reactors

    Energy Technology Data Exchange (ETDEWEB)

    1978-09-01

    The construction and operating experience of selected European Gas-Cooled Reactors is summarized along with technical descriptions of the plants. Included in the report are the AVR Experimental Pebble Bed Reactor, the Dragon Reactor, AGR Reactors, and the Thorium High Temperature Reactor (THTR). The study demonstrates that the European experience has been favorable and forms a good foundation for the development of Advanced High Temperature Reactors.

  18. Uncertainty Quantification of Calculated Temperatures for the U.S. Capsules in the AGR-2 Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Lybeck, Nancy [Idaho National Lab. (INL), Idaho Falls, ID (United States); Einerson, Jeffrey J. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Pham, Binh T. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Hawkes, Grant L. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-03-01

    A series of Advanced Gas Reactor (AGR) irradiation experiments are being conducted within the Advanced Reactor Technology (ART) Fuel Development and Qualification Program. The main objectives of the fuel experimental campaign are to provide the necessary data on fuel performance to support fuel process development, qualify a fuel design and fabrication process for normal operation and accident conditions, and support development and validation of fuel performance and fission product transport models and codes (PLN-3636). The AGR-2 test was inserted in the B-12 position in the Advanced Test Reactor (ATR) core at Idaho National Laboratory (INL) in June 2010 and successfully completed irradiation in October 2013, resulting in irradiation of the TRISO fuel for 559.2 effective full power days (EFPDs) during approximately 3.3 calendar years. The AGR-2 data, including the irradiation data and calculated results, were qualified and stored in the Nuclear Data Management and Analysis System (NDMAS) (Pham and Einerson 2014). To support the U.S. TRISO fuel performance assessment and to provide data for validation of fuel performance and fission product transport models and codes, the daily as-run thermal analysis has been performed separately on each of four AGR-2 U.S. capsules for the entire irradiation as discussed in (Hawkes 2014). The ABAQUS code’s finite element-based thermal model predicts the daily average volume-average fuel temperature and peak fuel temperature in each capsule. This thermal model involves complex physical mechanisms (e.g., graphite holder and fuel compact shrinkage) and properties (e.g., conductivity and density). Therefore, the thermal model predictions are affected by uncertainty in input parameters and by incomplete knowledge of the underlying physics leading to modeling assumptions. Therefore, alongside with the deterministic predictions from a set of input thermal conditions, information about prediction uncertainty is instrumental for the ART

  19. AGR-1 Irradiation Test Final As-Run Report, Rev. 3

    Energy Technology Data Exchange (ETDEWEB)

    Collin, Blaise P.

    2015-01-01

    This document presents the as-run analysis of the AGR-1 irradiation experiment. AGR-1 is the first of eight planned irradiations for the Advanced Gas Reactor (AGR) Fuel Development and Qualification Program. Funding for this program is provided by the US Department of Energy (DOE) as part of the Next-Generation Nuclear Plant (NGNP) project. The objectives of the AGR-1 experiment are: 1. To gain experience with multi-capsule test train design, fabrication, and operation with the intent to reduce the probability of capsule or test train failure in subsequent irradiation tests. 2. To irradiate fuel produced in conjunction with the AGR fuel process development effort. 3. To provide data that will support the development of an understanding of the relationship between fuel fabrication processes, fuel product properties, and irradiation performance. In order to achieve the test objectives, the AGR-1 experiment was irradiated in the B-10 position of the Advanced Test Reactor (ATR) at the Idaho National Laboratory (INL) for a total duration of 620 effective full power days of irradiation. Irradiation began on December 24, 2006 and ended on November 6, 2009 spanning 13 ATR cycles and approximately three calendar years. The test contained six independently controlled and monitored capsules. Each capsule contained 12 compacts of a single type, or variant, of the AGR coated fuel. No fuel particles failed during the AGR-1 irradiation. Final burnup values on a per compact basis ranged from 11.5 to 19.6 %FIMA, while fast fluence values ranged from 2.21 to 4.39 x 1025 n/m2 (E >0.18 MeV). We’ll say something here about temperatures once thermal recalc is done. Thermocouples performed well, failing at a lower rate than expected. At the end of the irradiation, nine of the originally-planned 19 TCs were considered functional. Fission product release-to-birth (R/B) ratios were quite low. In most capsules, R/B values at the end of the irradiation were at or below

  20. AGR-1 Irradiation Test Final As-Run Report, Rev. 3

    International Nuclear Information System (INIS)

    This document presents the as-run analysis of the AGR-1 irradiation experiment. AGR-1 is the first of eight planned irradiations for the Advanced Gas Reactor (AGR) Fuel Development and Qualification Program. Funding for this program is provided by the US Department of Energy (DOE) as part of the Next-Generation Nuclear Plant (NGNP) project. The objectives of the AGR-1 experiment are: 1. To gain experience with multi-capsule test train design, fabrication, and operation with the intent to reduce the probability of capsule or test train failure in subsequent irradiation tests. 2. To irradiate fuel produced in conjunction with the AGR fuel process development effort. 3. To provide data that will support the development of an understanding of the relationship between fuel fabrication processes, fuel product properties, and irradiation performance. In order to achieve the test objectives, the AGR-1 experiment was irradiated in the B-10 position of the Advanced Test Reactor (ATR) at the Idaho National Laboratory (INL) for a total duration of 620 effective full power days of irradiation. Irradiation began on December 24, 2006 and ended on November 6, 2009 spanning 13 ATR cycles and approximately three calendar years. The test contained six independently controlled and monitored capsules. Each capsule contained 12 compacts of a single type, or variant, of the AGR coated fuel. No fuel particles failed during the AGR-1 irradiation. Final burnup values on a per compact basis ranged from 11.5 to 19.6 %FIMA, while fast fluence values ranged from 2.21 to 4.39 x 1025 n/m2 (E >0.18 MeV). We'll say something here about temperatures once thermal recalc is done. Thermocouples performed well, failing at a lower rate than expected. At the end of the irradiation, nine of the originally-planned 19 TCs were considered functional. Fission product release-to-birth (R/B) ratios were quite low. In most capsules, R/B values at the end of the irradiation were at or below 10-7 with only one

  1. Identification of the agr Peptide of Listeria monocytogenes

    Science.gov (United States)

    Zetzmann, Marion; Sánchez-Kopper, Andrés; Waidmann, Mark S.; Blombach, Bastian; Riedel, Christian U.

    2016-01-01

    Listeria monocytogenes (Lm) is an important food-borne human pathogen that is able to strive under a wide range of environmental conditions. Its accessory gene regulator (agr) system was shown to impact on biofilm formation and virulence and has been proposed as one of the regulatory mechanisms involved in adaptation to these changing environments. The Lm agr operon is homologous to the Staphylococcus aureus system, which includes an agrD-encoded autoinducing peptide that stimulates expression of the agr genes via the AgrCA two-component system and is required for regulation of target genes. The aim of the present study was to identify the native autoinducing peptide (AIP) of Lm using a luciferase reporter system in wildtype and agrD deficient strains, rational design of synthetic peptides and mass spectrometry. Upon deletion of agrD, luciferase reporter activity driven by the PII promoter of the agr operon was completely abolished and this defect was restored by co-cultivation of the agrD-negative reporter strain with a producer strain. Based on the sequence and structures of known AIPs of other organisms, a set of potential Lm AIPs was designed and tested for PII-activation. This led to the identification of a cyclic pentapeptide that was able to induce PII-driven luciferase reporter activity and restore defective invasion of the agrD deletion mutant into Caco-2 cells. Analysis of supernatants of a recombinant Escherichia coli strain expressing AgrBD identified a peptide identical in mass and charge to the cyclic pentapeptide. The Lm agr system is specific for this pentapeptide since the AIP of Lactobacillus plantarum, which also is a pentapeptide yet with different amino acid sequence, did not induce PII activity. In summary, the presented results provide further evidence for the hypothesis that the agrD gene of Lm encodes a secreted AIP responsible for autoregulation of the agr system of Lm. Additionally, the structure of the native Lm AIP was identified.

  2. Identification of the agr Peptide of Listeria monocytogenes.

    Science.gov (United States)

    Zetzmann, Marion; Sánchez-Kopper, Andrés; Waidmann, Mark S; Blombach, Bastian; Riedel, Christian U

    2016-01-01

    Listeria monocytogenes (Lm) is an important food-borne human pathogen that is able to strive under a wide range of environmental conditions. Its accessory gene regulator (agr) system was shown to impact on biofilm formation and virulence and has been proposed as one of the regulatory mechanisms involved in adaptation to these changing environments. The Lm agr operon is homologous to the Staphylococcus aureus system, which includes an agrD-encoded autoinducing peptide that stimulates expression of the agr genes via the AgrCA two-component system and is required for regulation of target genes. The aim of the present study was to identify the native autoinducing peptide (AIP) of Lm using a luciferase reporter system in wildtype and agrD deficient strains, rational design of synthetic peptides and mass spectrometry. Upon deletion of agrD, luciferase reporter activity driven by the PII promoter of the agr operon was completely abolished and this defect was restored by co-cultivation of the agrD-negative reporter strain with a producer strain. Based on the sequence and structures of known AIPs of other organisms, a set of potential Lm AIPs was designed and tested for PII-activation. This led to the identification of a cyclic pentapeptide that was able to induce PII-driven luciferase reporter activity and restore defective invasion of the agrD deletion mutant into Caco-2 cells. Analysis of supernatants of a recombinant Escherichia coli strain expressing AgrBD identified a peptide identical in mass and charge to the cyclic pentapeptide. The Lm agr system is specific for this pentapeptide since the AIP of Lactobacillus plantarum, which also is a pentapeptide yet with different amino acid sequence, did not induce PII activity. In summary, the presented results provide further evidence for the hypothesis that the agrD gene of Lm encodes a secreted AIP responsible for autoregulation of the agr system of Lm. Additionally, the structure of the native Lm AIP was identified. PMID

  3. Validation of the Physics Analysis used to Characterize the AGR-1 TRISO Fuel Irradiation Test

    Energy Technology Data Exchange (ETDEWEB)

    Sterbentz, James W.; Harp, Jason M.; Demkowicz, Paul A.; Hawkes, Grant L.; Chang, Gray S.

    2015-05-01

    The results of a detailed physics depletion calculation used to characterize the AGR-1 TRISO-coated particle fuel test irradiated in the Advanced Test Reactor (ATR) at the Idaho National Laboratory are compared to measured data for the purpose of validation. The particle fuel was irradiated for 13 ATR power cycles over three calendar years. The physics analysis predicts compact burnups ranging from 11.30-19.56% FIMA and cumulative neutron fast fluence from 2.21?4.39E+25 n/m2 under simulated high-temperature gas-cooled reactor conditions in the ATR. The physics depletion calculation can provide a full characterization of all 72 irradiated TRISO-coated particle compacts during and post-irradiation, so validation of this physics calculation was a top priority. The validation of the physics analysis was done through comparisons with available measured experimental data which included: 1) high-resolution gamma scans for compact activity and burnup, 2) mass spectrometry for compact burnup, 3) flux wires for cumulative fast fluence, and 4) mass spectrometry for individual actinide and fission product concentrations. The measured data are generally in very good agreement with the calculated results, and therefore provide an adequate validation of the physics analysis and the results used to characterize the irradiated AGR-1 TRISO fuel.

  4. Determination of the Quantity of I-135 Released from the AGR Experiment Series

    Energy Technology Data Exchange (ETDEWEB)

    Scates, Dawn Marie [Idaho National Laboratory; Walter, John Bradley [Idaho National Laboratory; Reber, Edward Lawrence [Idaho National Laboratory; Sterbentz, James William [Idaho National Laboratory; Petti, David Andrew [Idaho National Laboratory

    2014-10-01

    A series of three Advanced Gas Reactor (AGR) experiments have been conducted in the Advanced Test Reactor (ATR) at Idaho National Laboratory (INL). From 2006 through 2014, these experiments supported the development and qualification of the new U.S. tri structural isotropic (TRISO) particle fuel for Very High Temperature Reactors (VHTR). Each AGR experiment consisted of multiple fueled capsules, each plumbed for independent temperature control using a mix of helium and neon gases. The gas leaving a capsule was routed to individual Fission Product Monitor (FPM) detectors. For intact fuel particles, the TRISO particle coatings provide a substantial barrier to fission product release. However, particles with failed coatings, whether because of a minute percentage of initially defective particles, those which fail during irradiation, or those designed to fail (DTF) particles, can release fission products to the flowing gas stream. Because reactive fission product elements like iodine and cesium quickly deposit on cooler capsule components and piping structures as the effluent gas leaves the reactor core, only the noble fission gas isotopes of Kr and Xe tend to reach FPM detectors. The FPM system utilizes High Purity Germanium (HPGe) detectors coupled with a thallium activated sodium iodide NaI(Tl) scintillator. The germanium detector provides individual isotopic information, while the NaI(Tl) scintillator is used as a gross count rate meter. During irradiation, the 135mXe concentration reaching the FPM detectors is from both direct fission and by decay of the accumulated 135I. About ~2.5 hours after irradiation (ten 15.3 minute 135mXe half lives) the directly produced 135mXe has decayed and only the longer lived 135I remains as a source. Decay systematics dictate that 135mXe will be in secular equilibrium with its 135I parent, such that it’s production rate very nearly equals the decay rate of the parent, and its concentration in the flowing gas stream will appear to

  5. Cloning of an agr homologue of Staphylococcus saprophyticus.

    Science.gov (United States)

    Sakinc, Türkan; Kulczak, Pawel; Henne, Karsten; Gatermann, Sören G

    2004-08-01

    An agr homologue of Staphylococcus saprophyticus was identified, cloned and sequenced. The gene locus shows homologies to other staphylococcal agr systems, especially to those of S. epidermidis and S. lugdunensis. A putative RNAIII was identified and found to be differentially expressed during the growth phases. In contrast to the RNAIII molecules of S. epidermidis and S. aureus it does not contain an open reading frame that codes for a protein with homologies to the delta-toxin. Using PCR, the agr was found to be present in clinical isolates of S. saprophyticus.

  6. Operational and reliability experience with reactor instrumentation

    International Nuclear Information System (INIS)

    In the last 15 years the CEGB has experienced progressive plant development, integration and changes in operating regime through nine nuclear (gas-cooled reactor) power stations with corresponding instrumentation advances leading towards more refined centralized control. Operation and reliability experience with reactor instrumentation is reported in this paper with reference to the progressive changes related to the early magnox, late magnox and AGR periods. Data on instrumentation reliability in terms of reactor forced outages are presented and show that the instrumentation contributions to loss of generating plant availability are small. Reactor safety circuits, neutron flux and temperature measurements, gas analysis and vibration monitoring are discussed. In reviewing the reactor instrumentation the emphasis is on reporting recent experience, particularly on AGR equipment, but overall performance and changes to magnox equipment are included so that some appreciation can be obtained of instrumentation requirements with respect to plant lifetimes. (author)

  7. AGR-2 Final Data Qualification Report for U.S. Capsules - ATR Cycles 147A Through 154B

    Energy Technology Data Exchange (ETDEWEB)

    Pham, Binh T. [Idaho National Lab. (INL), Idaho Falls, ID (United States). Very High-Temperature Reactor Technology Development Office; Einerson, Jeffrey J. [Idaho National Lab. (INL), Idaho Falls, ID (United States). Very High-Temperature Reactor Technology Development Office

    2014-07-01

    This report provides the data qualification status of AGR-2 fuel irradiation experimental data in four U.S. capsules from all 15 Advanced Test Reactor (ATR) Cycles 147A, 148A, 148B, 149A, 149B, 150A, 150B, 151A, 151B, 152A, 152B, 153A, 153B, 154A, and 154B, as recorded in the Nuclear Data Management and Analysis System (NDMAS). Thus, this report covers data qualification status for the entire AGR-2 irradiation and will replace four previously issued AGR-2 data qualification reports (e.g., INL/EXT-11-22798, INL/EXT-12-26184, INL/EXT-13-29701, and INL/EXT-13-30750). During AGR-2 irradiation, two cycles, 152A and 153A, occurred when the ATR core was briefly at low power, so AGR-2 irradiation data are not used for physics and thermal calculations. Also, two cycles, 150A and 153B, are Power Axial Locator Mechanism (PALM) cycles when the ATR power is higher than during normal cycles. During the first PALM cycle, 150A, the experiment was temporarily moved from the B-12 location to the ATR water canal and during the second PALM cycle, 153B, the experiment was temporarily moved from the B-12 location to the I-24 location to avoid being overheated. During the “Outage” cycle, 153A, seven flow meters were installed downstream from seven Fission Product Monitoring System (FPMS) monitors to measure flows from the monitors and these data are included in the NDMAS database.

  8. Processing and microstructural characterisation of a UO2-based ceramic for disposal studies on spent AGR fuel

    International Nuclear Information System (INIS)

    Preparation and characterisation of a Simulated Spent Nuclear Fuel (SIMFuel), which replicates the chemical state and microstructure of Spent Nuclear Fuel (SNF) discharged from a UK Advanced Gas-cooled Reactor (AGR) after a cooling time of 100 years is described. Given the relatively small differences in radionuclide inventory expected over longer time periods, the SIMFuel studied in this work is expected to be also representative of spent fuel after significantly longer periods (e.g. 1000 years). Thirteen stable elements were added to depleted UO2 and sintered to simulate the composition of fuel pellets after burn-ups of 25 and 43 GWd/tU and, as a reference, pure UO2 pellets were also investigated. The fission product distribution was calculated using the FISPIN code provided by the UK National Nuclear Laboratory. SIMFuel pellets were up to 92% dense and during the sintering process in H2 atmosphere Mo–Ru–Rh–Pd metallic precipitates and grey-phase ((Ba, Sr)(Zr, RE) O3 oxide precipitates) formed within the UO2 matrix. These secondary phases are present in real PWR and AGR SNF. Metallic precipitates are generally spherical and have submicron particle size (0.8 ± 0.7 μm). Spherical oxide precipitates in SIMFuel measured up to 30 μm in diameter, but no data were available in the public domain to compare this to AGR SNF. The grain size of actual AGR SNF (∼3–30 μm) is larger than that measured in AGR SIMFuel (∼2–5 μm)

  9. Nasal Carriage as a Source of agr-Defective Staphylococcus aureus Bacteremia

    OpenAIRE

    Smyth, Davida S.; Kafer, Jared M.; Wasserman, Gregory A.; Velickovic, Lili; Mathema, Barun; Robert S Holzman; Knipe, Tiffany A.; Becker, Karsten; von Eiff, Christof; Peters, Georg; Chen, Liang; Kreiswirth, Barry N.; Novick, Richard P.; Shopsin, Bo

    2012-01-01

    Inactivating mutations in the Staphylococcus aureus virulence regulator agr are associated with worse outcomes in bacteremic patients. However, whether agr dysfunction is primarily a cause or a consequence of early bacteremia is unknown. Analysis of 158 paired S. aureus clones from blood and nasal carriage sites in individual patients revealed that recovery of an agr-defective mutant from blood was usually predicted by the agr functionality of carriage isolates. Many agr-positive blood isolat...

  10. AGR2 Predicts Tamoxifen Resistance in Postmenopausal Breast Cancer Patients

    Directory of Open Access Journals (Sweden)

    Roman Hrstka

    2013-01-01

    Full Text Available Endocrine resistance is a significant problem in breast cancer treatment. Thus identification and validation of novel resistance determinants is important to improve treatment efficacy and patient outcome. In our work, AGR2 expression was determined by qRT-PCR in Tru-Cut needle biopsies from tamoxifen-treated postmenopausal breast cancer patients. Our results showed inversed association of AGR2 mRNA levels with primary treatment response (P=0.0011 and progression-free survival (P=0.0366 in 61 ER-positive breast carcinomas. As shown by our experimental and clinical evaluations, elevated AGR2 expression predicts decreased efficacy of tamoxifen treatment. From this perspective, AGR2 is a potential predictive biomarker enabling selection of an optimal algorithm for adjuvant hormonal therapy in postmenopausal ER-positive breast cancer patients.

  11. Zoning Districts, ag-res, Published in 2008, Duchesne County.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Zoning Districts dataset, was produced all or in part from Other information as of 2008. It is described as 'ag-res'. Data by this publisher are often provided...

  12. AGR2 Predicts Tamoxifen Resistance in Postmenopausal Breast Cancer Patients

    OpenAIRE

    Roman Hrstka; Veronika Brychtova; Pavel Fabian; Borivoj Vojtesek; Marek Svoboda

    2013-01-01

    Endocrine resistance is a significant problem in breast cancer treatment. Thus identification and validation of novel resistance determinants is important to improve treatment efficacy and patient outcome. In our work, AGR2 expression was determined by qRT-PCR in Tru-Cut needle biopsies from tamoxifen-treated postmenopausal breast cancer patients. Our results showed inversed association of AGR2 mRNA levels with primary treatment response (P = 0.0011) and progression-free survival (P = 0.0366)...

  13. The Windscale inquiry. Report by the Hon. Justice Parker, presented to the Secretary of State for the Environment on 26 January 1978

    International Nuclear Information System (INIS)

    This Volume I contains the official Report by the Inspector appointed to conduct a local enquiry for the purpose of hearing objections and representations relating to an application by British Nuclear Fuels Limited for planning permission for a plant for reprocessing irradiated oxide nuclear fuels and support services at their Windscale and Calder Works. The report falls under the following headings: introduction; essential background; history of the application; scope of the Inquiry; summary of contentions and structure of the report; the nuclear weapons proliferation question; terrorism and civil liberties; the need for reprocessing of oxide fuel and relationship to the FBR question; financial aspects; routine discharges - risks; risks - accidents; size of plant; public hostility; conventional planning issues; the Inquiry itself; overall conclusion and recommendation; summary of principal conclusions and recommendations; miscellaneous matters. The volume also contains three of the five Annexes to the Report: Annex 3 - somatic risk estimates; Annex 4 - genetic risk estimates; and Annex 5 - mean genetic dose to local population. (Annex 1 - list of appearances and Annex 2 - list of documents, are contained in Volume 2, and the Index to the Report is Volume 3). (U.K.)

  14. Fabrication and Comparison of Fuels for Advanced Gas Reactor Irradiation Tests

    Energy Technology Data Exchange (ETDEWEB)

    Jeffrey Phillips; Charles Barnes; John Hunn

    2010-10-01

    As part of the program to demonstrate TRISO-coated fuel for the Next Generation Nuclear Plant, a series of irradiation tests of Advanced Gas Reactor (AGR) fuel are being performed in the Advanced Test Reactor (ATR) at the Idaho National Laboratory. In the first test, called “AGR-1,” graphite compacts containing approximately 300,000 coated particles were irradiated from December 2006 until November 2009. Development of AGR-1 fuel sought to replicate the properties of German TRISO-coated particles. No particle failures were seen in the nearly 3-year irradiation to a burn up of 19%. The AGR-1 particles were coated in a two-inch diameter coater. Following fabrication of AGR-1 fuel, process improvements and changes were made in each of the fabrication processes. Changes in the kernel fabrication process included replacing the carbon black powder feed with a surface-modified carbon slurry and shortening the sintering schedule. AGR-2 TRISO particles were produced in a six-inch diameter coater using a change size about twenty-one times that of the two-inch diameter coater used to coat AGR-1 particles. Changes were also made in the compacting process, including increasing the temperature and pressure of pressing and using a different type of press. Irradiation of AGR-2 fuel began in late spring 2010. Properties of AGR-2 fuel compare favorably with AGR-1 and historic German fuel. Kernels are more homogeneous in shape, chemistry and density. TRISO-particle sphericity, layer thickness standard deviations, and defect fractions are also comparable. In a sample of 317,000 particles from deconsolidated AGR-2 compacts, 3 exposed kernels were found in a leach test. No SiC defects were found in a sample of 250,000 deconsolidated particles, and no IPyC defects in a sample of 64,000 particles. The primary difference in properties between AGR-1 and AGR-2 compacts is that AGR-2 compacts have a higher matrix density, 1.6 g/cm3 compared to about 1.3 g/cm3 for AGR-1 compacts. Based on

  15. Fabrication and Comparison of Fuels for Advanced Gas Reactor Irradiation Tests

    International Nuclear Information System (INIS)

    As part of the program to demonstrate TRISO-coated fuel for the Next Generation Nuclear Plant, a series of irradiation tests of Advanced Gas Reactor (AGR) fuel are being performed in the Advanced Test Reactor (ATR) at the Idaho National Laboratory. In the first test, called 'AGR-1,' graphite compacts containing approximately 300,000 coated particles were irradiated from December 2006 until November 2009. Development of AGR-1 fuel sought to replicate the properties of German TRISO-coated particles. No particle failures were seen in the nearly 3-year irradiation to a burn up of 19%. The AGR-1 particles were coated in a two-inch diameter coater. Following fabrication of AGR-1 fuel, process improvements and changes were made in each of the fabrication processes. Changes in the kernel fabrication process included replacing the carbon black powder feed with a surface-modified carbon slurry and shortening the sintering schedule. AGR-2 TRISO particles were produced in a six-inch diameter coater using a change size about twenty-one times that of the two-inch diameter coater used to coat AGR-1 particles. Changes were also made in the compacting process, including increasing the temperature and pressure of pressing and using a different type of press. Irradiation of AGR-2 fuel began in late spring 2010. Properties of AGR-2 fuel compare favorably with AGR-1 and historic German fuel. Kernels are more homogeneous in shape, chemistry and density. TRISO-particle sphericity, layer thickness standard deviations, and defect fractions are also comparable. In a sample of 317,000 particles from deconsolidated AGR-2 compacts, 3 exposed kernels were found in a leach test. No SiC defects were found in a sample of 250,000 deconsolidated particles, and no IPyC defects in a sample of 64,000 particles. The primary difference in properties between AGR-1 and AGR-2 compacts is that AGR-2 compacts have a higher matrix density, 1.6 g/cm3 compared to about 1.3 g/cm3 for AGR-1 compacts. Based on fuel

  16. Post-irradiation Examination of the AGR-1 Experiment: Plans and Preliminary Results

    Energy Technology Data Exchange (ETDEWEB)

    Paul Demkowicz

    2001-10-01

    Abstract – The AGR-1 irradiation experiment contains seventy-two individual cylindrical fuel compacts (25 mm long x 12.5 mm diameter) each containing approximately 4100 TRISO-coated uranium oxycarbide fuel particles. The experiment accumulated 620 effective full power days in the Advanced Test Reactor at the Idaho National Laboratory with peak burnups exceeding 19% FIMA. An extensive post-irradiation examination campaign will be performed on the AGR-1 fuel in order to characterize the irradiated fuel properties, assess the in-pile fuel performance in terms of coating integrity and fission metals release, and determine the fission product retention behavior during high temperature accident testing. PIE experiments will include dimensional measurements of fuel and irradiated graphite, burnup measurements, assessment of fission metals release during irradiation, evaluation of coating integrity using the leach-burn-leach technique, microscopic examination of kernel and coating microstructures, and accident testing of the fuel in helium at temperatures up to 1800°C. Activities completed to date include opening of the irradiated capsules, measurement of fuel dimensions, and gamma spectrometry of selected fuel compacts.

  17. AGR-3/4 Data Qualification Report for ATR Cycles 151A, 151B, 152A, 152B, 154A, and 154B

    Energy Technology Data Exchange (ETDEWEB)

    Binh T. Pham

    2014-02-01

    This data report provides the qualification status of Advanced Gas Reactor-3/4 (AGR-3/4) fuel irradiation experimental data from Advanced Test Reactor (ATR) Cycles 151A, 151B, 152A, 152B, 154A, and 154B, as recorded in the Nuclear Data Management and Analysis System (NDMAS). Of these cycles, ATR Cycle 152A is a low power cycle that occurred when the ATR core was briefly at low power. The irradiation data are not used for physics and thermal calculation, but the qualification status of these cycle data is still covered in this report. On the other hand, during ATR Cycles 153A (unplanned Outage cycle) and 153B (Power Axial Locator Mechanism [PALM] cycle), the AGR-3/4 was pulled out from the ATR core and stored in the canal to avoid being overheated. Therefore, qualification of the AGR-3/4 irradiation data from these 2 cycles was excluded in this report. By the end of ATR Cycle 154B, AGR-3/4 was irradiated for a total of 264.1 effective full power days. The AGR-3/4 data streams addressed in this report include thermocouple (TC) temperatures, sweep gas data (flow rates, pressure, and moisture content), and Fission Product Monitoring System (FPMS) data (release rates and release-to-birth rate ratios [R/Bs]) for each of the twelve capsules in the AGR-3/4 experiment. The final data qualification status for these data streams is determined by a Data Review Committee (DRC) composed of AGR technical leads, Sitewide Quality Assurance (QA), and NDMAS analysts. The DRC convened on February 12, 2014, reviewed the data acquisition process, and considered whether the data met the requirements for data collection as specified in QA-approved Very High Temperature Reactor (VHTR) Technology Development Office (TDO) data collection plans. The DRC also examined the results of NDMAS data testing and statistical analyses, and confirmed the qualification status of the data as given in this report.

  18. Lessons Learned From Gen I Carbon Dioxide Cooled Reactors

    Energy Technology Data Exchange (ETDEWEB)

    David E. Shropshire

    2004-04-01

    This paper provides a review of early gas cooled reactors including the Magnox reactors originating in the United Kingdom and the subsequent development of the Advanced Gas-cooled Reactors (AGR). These early gas cooled reactors shared a common coolant medium, namely carbon dioxide (CO2). A framework of information is provided about these early reactors and identifies unique problems/opportunities associated with use of CO2 as a coolant. Reactor designers successfully rose to these challenges. After years of successful use of the CO2 gas cooled reactors in Europe, the succeeding generation of reactors, called the High Temperature Gas Reactors (HTGR), were designed with Helium gas as the coolant. Again, in the 21st century, with the latest reactor designs under investigation in Generation IV, there is a revived interest in developing Gas Cooled Fast Reactors that use CO2 as the reactor coolant. This paper provides a historical perspective on the 52 CO2 reactors and the reactor programs that developed them. The Magnox and AGR design features and safety characteristics were reviewed, as well as the technologies associated with fuel storage, reprocessing, and disposal. Lessons-learned from these programs are noted to benefit the designs of future generations of gas cooled nuclear reactors.

  19. Analysis of Fission Products on the AGR-1 Capsule Components

    Energy Technology Data Exchange (ETDEWEB)

    Paul A. Demkowicz; Jason M. Harp; Philip L. Winston; Scott A. Ploger

    2013-03-01

    The components of the AGR-1 irradiation capsules were analyzed to determine the retained inventory of fission products in order to determine the extent of in-pile fission product release from the fuel compacts. This includes analysis of (i) the metal capsule components, (ii) the graphite fuel holders, (iii) the graphite spacers, and (iv) the gas exit lines. The fission products most prevalent in the components were Ag-110m, Cs 134, Cs 137, Eu-154, and Sr 90, and the most common location was the metal capsule components and the graphite fuel holders. Gamma scanning of the graphite fuel holders was also performed to determine spatial distribution of Ag-110m and radiocesium. Silver was released from the fuel components in significant fractions. The total Ag-110m inventory found in the capsules ranged from 1.2×10 2 (Capsule 3) to 3.8×10 1 (Capsule 6). Ag-110m was not distributed evenly in the graphite fuel holders, but tended to concentrate at the axial ends of the graphite holders in Capsules 1 and 6 (located at the top and bottom of the test train) and near the axial center in Capsules 2, 3, and 5 (in the center of the test train). The Ag-110m further tended to be concentrated around fuel stacks 1 and 3, the two stacks facing the ATR reactor core and location of higher burnup, neutron fluence, and temperatures compared with Stack 2. Detailed correlation of silver release with fuel type and irradiation temperatures is problematic at the capsule level due to the large range of temperatures experienced by individual fuel compacts in each capsule. A comprehensive Ag 110m mass balance for the capsules was performed using measured inventories of individual compacts and the inventory on the capsule components. For most capsules, the mass balance was within 11% of the predicted inventory. The Ag-110m release from individual compacts often exhibited a very large range within a particular capsule.

  20. New insight into transmembrane topology of Staphylococcus aureus histidine kinase AgrC.

    Science.gov (United States)

    Wang, Lina; Quan, Chunshan; Xiong, Wen; Qu, Xiaojing; Fan, Shengdi; Hu, Wenzhong

    2014-03-01

    Staphylococcus aureus accessory gene regulator (agr) locus controls the expression of virulence factors through a classical two-component signal transduction system that consists of a receptor histidine protein kinase AgrC and a cytoplasmic response regulator AgrA. An autoinducing peptide (AIP) encoded by agr locus activates AgrC, which transduces extracellular signals into the cytoplasm. Despite extensive investigations to identify AgrC-AIP interaction sites, precise signal recognition mechanisms remain unknown. This study aims to clarify the membrane topology of AgrC by applying the green fluorescent protein (GFP) fusion technique and the substituted cysteine accessibility method (SCAM). However, our findings were inconsistent with profile obtained previously by alkaline phosphatase. We report the topology of AgrC shows seven transmembrane segments, a periplasmic N-terminus, and a cytoplasmic C-terminus. PMID:24361366

  1. AGROCOOP Tienda Online Cooperativas Agrícolas

    OpenAIRE

    Segura Rama, José Ignacio

    2016-01-01

    El presente Trabajo Fin de Master versa sobre la elaboración, creación, programación, diseño y puesta en marcha de una tienda online AVANZADA para cooperativas agrícolas, queremos mostrar como poder crear una tienda e-comerce para cooperativas agrícolas de nuestro País. Con ello queremos así abrir el mercado de estas, ademas de mostrar como usar un gran compendio de tecnologías. Vamos a agrupar y poner en común, un conjunto amplio de distintas técnicas de programación web, que ...

  2. Producción agrícola controlada

    OpenAIRE

    Abraham Rojano A.; Raquel Salazar M.; Álvaro Llamas G.

    2004-01-01

    A diferencia de la producción de bienes industriales donde se puede trabajar día y noche y en diferentes lugares al mismo tiempo, la producción agrícola tiene componentes físicos y químicos en interacción con componentes vivos. Los factores físicos y químicos son factibles de trabajar con enfoques industriales de acuerdo a las reglas básicas del control; sin embargo, el componente vivo de la producción agrícola esta condicionado hasta la fecha por un proceso ineludible: la foto...

  3. El Ingeniero Agrícola en la Agroindustria

    Directory of Open Access Journals (Sweden)

    Ramos Sarria Ramiro

    1985-12-01

    Full Text Available En este artículo se da a conocer la capacidad técnica y administrativa que posee el Ingeniero Agrícola, para organizar un sistema coherente que logre definir, planificar y promover una política de desarrollo científico y tecnológico en la agroindustria.

  4. Need for USA high level waste (HLW) alternate geological repository (AGR) and for a different methodology to enhance its acceptance

    International Nuclear Information System (INIS)

    In early February 2010, the administration stopped work and withdrew the Department of Energy (DOE) application for a construction permit for the Yucca Mountain geological repository from the Nuclear Regulatory Commission (NRC). Also, a 'blue ribbon' Commission was appointed to explore alternatives for storage, processing, and disposal, including evaluation of advanced fuel cycles and to provide a final report in 24 months. That decision, however, failed to recognize that: (1) the U.S. will need an early alternate geological repository (AGR) for its HLW irrespective of the findings of the 'blue ribbon' Commission; (2) the once-through spent fuel inventory from commercial nuclear power reactors will continue to rise and so will the damages against the government for its failure to remove spent fuel from reactors sites, as specified in contracts; (3) there are prepackaged DOE and nuclear weapons HLW ready for shipment to a repository which must be taken into account because of government penalties for failure to do so; (4) the current Nuclear Waste Policy Act (NWPA) needs to be modified to allow the early search and approval of Alternate Geological Repository (AGR) and for an interim centralized HLW storage facility to reduce government liabilities; and (5) the methodology used to license Yucca Mountain needs to undergo serious modifications, including a different non-politicized management and siting credo. This paper reviews and discusses all the preceding shortcomings and proposes significant changes to pursue AGR as soon as possible and to get site approval by the NRC first under a formal, stepwise, well-structured risk-informed decision approach as recommended.

  5. Producción agrícola controlada

    Directory of Open Access Journals (Sweden)

    Abraham Rojano A.

    2004-01-01

    Full Text Available A diferencia de la producción de bienes industriales donde se puede trabajar día y noche y en diferentes lugares al mismo tiempo, la producción agrícola tiene componentes físicos y químicos en interacción con componentes vivos. Los factores físicos y químicos son factibles de trabajar con enfoques industriales de acuerdo a las reglas básicas del control; sin embargo, el componente vivo de la producción agrícola esta condicionado hasta la fecha por un proceso ineludible: la fotosíntesis. Esto es, una vez que el proceso agrícola inicia, se puede jugar un poco con las variables en el transcurso, sin embargo el final es inevitable como parte de una ley fundamental del ciclo natural, i.e., nacer, crecer, reproducir y morir. Por lo tanto, el proceso agrícola, a grandes rasgos presenta el reto de controlar: a variables físicas y químicas como función de espacio y tiempo tales como temperatura, humedad, luz, conductividad eléctrica, pH, concentraciones de CO2, relación de actividad fotosintética (PAR, entre otras; y b variables biológicas como el crecimiento, la producción de biomasa, y transpiración efectiva. Aun mas, el control de las variables mencionadas lleva consigo el desafió de mantener la producción agrícola dentro del campo de la ética y de las restricciones del mercado.

  6. Design of the Advanced Gas Reactor Fuel Experiments for Irradiation in the Advanced Test Reactor

    Energy Technology Data Exchange (ETDEWEB)

    S. Blaine Grover

    2005-10-01

    The United States Department of Energy’s Advanced Gas Reactor (AGR) Fuel Development and Qualification Program will be irradiating eight particle fuel tests in the Advanced Test Reactor (ATR) located at the newly formed Idaho National Laboratory (INL) to support development of the next generation Very High Temperature Reactor (VHTR) in the United States. The ATR has a long history of irradiation testing in support of reactor development and the INL has been designated as the new United States Department of Energy’s lead laboratory for nuclear energy development. These AGR fuel experiments will be irradiated over the next ten years to demonstrate and qualify new particle fuel for use in high temperature gas reactors. The experiments will be irradiated in an inert sweep gas atmosphere with on-line temperature monitoring and control combined with on-line fission product monitoring of the sweep gas. The final design phase has just been completed on the first experiment (AGR-1) in this series and the support systems and fission product monitoring system that will monitor and control the experiment during irradiation. This paper discusses the development of the experimental hardware and support system designs and the status of the experiment.

  7. An Assessment of ORNL PIE Capabilities for the AGR Program Capsule Post Irradiation Examination

    Energy Technology Data Exchange (ETDEWEB)

    Morris, Robert Noel [ORNL

    2006-09-01

    ORNL has facilities and experienced staff that can execute +the Advanced Gas Reactor (AGR) Post Irradiation Examination (PIE) task. While the specific PIE breakdown needs to be more formally defined, the basic outline is clear and the existing capabilities can be assessed within the needs of the tasks defined in the program plan. A one-to-one correspondence between the program plan tasks and the current ORNL PIE status was conducted and while some shortcomings were identified, the general capability is available. Specific upgrade needs were identified and reviewed. A path forward was formulated. Building 3525 is available for this work and this building is currently receiving renewed attention from management so that it will be in good working order prior to the expected PIE start date. This building is equipped with the tools necessary for PIEs of this nature, but the long hiatus in coated particle fuel work has left it with aging analysis tools. This report identified several of these tools and rough estimates of what would be required to update and replace them. In addition, other ORNL buildings are available to support Building 3525 in specialized tasks along with the normal laboratory infrastructure. Before the AGR management embarks on any equipment development effort, the PIE tasks should be updated against current program (modeling and data) needs and better defined so that the items to be measured, their measurement uncertainties, and thru-put needs can be reviewed. A Data Task Matrix (DTM) should be prepared so that the program data needs can be compared against the identified PIE tasks and what is practical in the hot cell environment to make sure nothing is overlooked. Finally, thought should be given to the development of standardized equipment designs between sites to avoid redundant design efforts and different measurement techniques. This is a potentially cost saving effort that can also avoid data inconsistencies.

  8. La Misión del Agrónomo

    Directory of Open Access Journals (Sweden)

    Caicedo A.

    1942-08-01

    Full Text Available La agronomía, como todas las profesiones que surgen en el plano de las necesidades sociales, estará sujeta en sus primeros años de existencia a un proceso riguroso de adaptación. La primera fuerza opositora que halla el agrónomo en su labor es la impreparación ciega y el empirismo secular del campesino, quien cree abarcar todos los conocimientos y dominar todos los aspectos de su oficio. Aparte de esta misión exclusivamente social y por demás larga y difícil, caracteriza al agrónomo su calidad de creador de riqueza nacional.

  9. The behaviour of defected AGR fuel pins during water storage

    International Nuclear Information System (INIS)

    Results are presented of measurements made on the release of radioactivity to simulated Board AGR pond water from irradiated CAGR fuel pins, which have suspected genuine or artificially induced clad defects. Six fuel pins have been examined, one having the top end cap removed, two having suspected end cap defects and three with a 1 mm hole pierced through the clad; two of these three latter pins were only partially immersed and had the end cap in the gas space removed. The work completes the first phase of a series of experiments carried out at AEE Winfrith to gain an understanding of the behaviour of defective AGR fuel pins during aqueous storage. Data are given on the release fractions found for Cs-137, Sr-90, Ru-106, Sb-125 and Ce-144. Analytical data from earlier experiments which have recently become available are also presented. (U.K.)

  10. 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.

  11. Trabajadores agrícolas y subjetividad en California

    Directory of Open Access Journals (Sweden)

    Florencio Posadas Segura

    2014-01-01

    Full Text Available En este trabajo se explora el problema de la subjetividad de los trabajadores agríco - las, partiendo de la hipótesis de que éstos consideran malas sus condiciones de vida y de trabajo. Mediante el trabajo de campo se demostraron sus conocimientos y opi - niones sobre su situación laboral y existencial en el Valle de San Joaquín California durante 2007 y 2008. Se descubrió que la visión del trabajador agrícola está basada en la subjetivación y reinterpretación de sus circunstancias objetivas de trabajo y de vida. Se concluyó que los trabajadores agrícolas opinan que sus condiciones son pé - simas porque sus derechos laborales, sociales y humanos no se reconocen o respetan, la crisis económica, social y política de Estados Unidos les perjudica y el Tratado de Libre Comercio entre México, Estados Unidos y Canadá ( TLCAN sólo podría beneficiarles con una reforma migratoria.

  12. XerC Contributes to Diverse Forms of Staphylococcus aureus Infection via agr-Dependent and agr-Independent Pathways.

    Science.gov (United States)

    Atwood, Danielle N; Beenken, Karen E; Loughran, Allister J; Meeker, Daniel G; Lantz, Tamara L; Graham, Justin W; Spencer, Horace J; Smeltzer, Mark S

    2016-04-01

    We demonstrate that mutation of xerC, which reportedly encodes a homologue of an Escherichia coli recombinase, limits biofilm formation in the methicillin-resistant Staphylococcus aureus strain LAC and the methicillin-sensitive strain UAMS-1. This was not due to the decreased production of the polysaccharide intracellular adhesin (PIA) in either strain because the amount of PIA was increased in a UAMS-1xerC mutant and undetectable in both LAC and its isogenic xerC mutant. Mutation of xerC also resulted in the increased production of extracellular proteases and nucleases in both LAC and UAMS-1, and limiting the production of either class of enzymes increased biofilm formation in the isogenic xerC mutants. More importantly, the limited capacity to form a biofilm was correlated with increased antibiotic susceptibility in both strains in the context of an established biofilm in vivo. Mutation of xerC also attenuated virulence in a murine bacteremia model, as assessed on the basis of the bacterial loads in internal organs and overall lethality. It also resulted in the decreased accumulation of alpha toxin and the increased accumulation of protein A. These findings suggest that xerC may impact the functional status of agr. This was confirmed by demonstrating the reduced accumulation of RNAIII and AgrA in LAC and UAMS-1xerC mutants. However, this cannot account for the biofilm-deficient phenotype of xerC mutants because mutation of agr did not limit biofilm formation in either strain. These results demonstrate that xerC contributes to biofilm-associated infections and acute bacteremia and that this is likely due to agr-independent and -dependent pathways, respectively.

  13. Neutronic of heterogenous gas cooled reactors

    International Nuclear Information System (INIS)

    At present, one of the main technical features of the advanced gas cooled reactor under development is its fuel element concept, which implies a neutronic homogeneous design, thus requiring higher enrichment compared with present commercial nuclear power plants.In this work a neutronic heterogeneous gas cooled reactor design is analyzed by studying the neutronic design of the Advanced Gas cooled Reactor (AGR), a low enrichment, gas cooled and graphite moderated nuclear power plant.A search of merit figures (some neutronic parameter, characteristic dimension, or a mixture of both) which are important and have been optimized during the reactor design stage is been done, to aim to comprise how a gas heterogeneous reactor is been design, given that semi-infinity arrangement criteria of rods in LWRs and clusters in HWRs can t be applied for a solid moderator and a gas refrigerator.The WIMS code for neutronic cell calculations is been utilized to model the AGR fuel cell and to calculate neutronic parameters such as the multiplication factor and the pick factor, as function of the fuel burnup.Also calculation is been done for various nucleus characteristic dimensions values (fuel pin radius, fuel channel pitch) and neutronic parameters (such as fuel enrichment), around the design established parameters values.A fuel cycle cost analysis is carried out according to the reactor in study, and the enrichment effect over it is been studied.Finally, a thermal stability analysis is been done, in subcritical condition and at power level, to study this reactor characteristic reactivity coefficients.Present results shows (considering the approximation used) a first set of neutronic design figures of merit consistent with the AGR design.

  14. Ceramographic Examinations of Irradiated AGR-1 Fuel Compacts

    Energy Technology Data Exchange (ETDEWEB)

    Paul Demkowicz; Scott Ploger; John Hunn

    2012-05-01

    The AGR 1 experiment involved irradiating 72 cylindrical fuel compacts containing tri-structural isotropic (TRISO)-coated particles to a peak burnup of 19.5% fissions per initial metal atom with no in-pile failures observed out of almost 300,000 particles. Five irradiated AGR 1 fuel compacts were selected for microscopy that span a range of irradiation conditions (temperature, burnup, and fast fluence). These five compacts also included all four TRISO coating variations irradiated in the AGR experiment. The five compacts were cross-sectioned both transversely and longitudinally, mounted, ground, and polished after development of careful techniques for preserving particle structures against preparation damage. Approximately 40 to 80 particles within each cross section were exposed near enough to mid-plane for optical microscopy of kernel, buffer, and coating behavior. The microstructural analysis focused on kernel swelling and porosity, buffer densification and fracture, debonding between the buffer and inner pyrolytic carbon (IPyC) layers, and fractures in the IPyC and SiC layers. Three basic particle morphologies were established according to the extent of bonding between the buffer and IPyC layers: complete debonding along the interface (Type A), no debonding along the interface (Type B), and partial debonding (Type AB). These basic morphologies were subdivided according to whether the buffer stayed intact or fractured. The resulting six characteristic morphologies were used to classify particles within each cross section, but no spatial patterns were clearly observed in any of the cross-sectional morphology maps. Although positions of particle types appeared random within compacts, examining a total of 830 classified particles allowed other relationships among morphological types to be established.

  15. Microscopic analysis of irradiated AGR-1 coated particle fuel compacts

    Energy Technology Data Exchange (ETDEWEB)

    Scott Ploger; Paul Demkowicz; John Hunn; Robert Morris

    2012-10-01

    The AGR-1 experiment involved irradiation of 72 TRISO-coated particle fuel compacts to a peak burnup of 19.5% FIMA with no in-pile failures observed out of 3×105 total particles. Irradiated AGR-1 fuel compacts have been cross-sectioned and analyzed with optical microscopy to characterize kernel, buffer, and coating behavior. Five compacts have been examined so far, spanning a range of irradiation conditions (burnup, fast fluence, and irradiation temperature) and including all four TRISO coating variations irradiated in the AGR-1 experiment. The cylindrical specimens were sectioned both transversely and longitudinally, then polished to expose between approximately 40-80 individual particles on each mount. The analysis focused primarily on kernel swelling and porosity, buffer densification and fracturing, buffer-IPyC debonding, and fractures in the IPyC and SiC layers. Characteristic morphologies have been identified, over 800 particles have been classified, and spatial distributions of particle types have been mapped. No significant spatial patterns were discovered in these cross sections. However, some trends were found between morphological types and certain behavioral aspects. Buffer fractures were found in approximately 23% of the particles, and these fractures often resulted in unconstrained kernel swelling into the open cavities. Fractured buffers and buffers that stayed bonded to IPyC layers appear related to larger pore size in kernels. Buffer-IPyC interface integrity evidently factored into initiation of rare IPyC fractures. Fractures through part of the SiC layer were found in only three particles, all in conjunction with IPyC-SiC debonding. Compiled results suggest that the deliberate coating fabrication variations influenced the frequencies of IPyC fractures, IPyC-SiC debonds, and SiC fractures.

  16. Ceramographic Examinations of Irradiated AGR-1 Fuel Compacts

    Energy Technology Data Exchange (ETDEWEB)

    Paul Demkowicz; Scott Ploger; John Hunn; Jay S. Kehn

    2012-09-01

    The AGR 1 experiment involved irradiating 72 cylindrical fuel compacts containing tri-structural isotropic (TRISO)-coated particles to a peak burnup of 19.5% fissions per initial metal atom with no in-pile failures observed out of almost 300,000 particles. Six irradiated AGR 1 fuel compacts were selected for microscopy that span a range of irradiation conditions (temperature, burnup, and fast fluence). These six compacts also included all four TRISO coating variations irradiated in the AGR experiment. The six compacts were cross-sectioned both transversely and longitudinally, mounted, ground, and polished after development of careful techniques for preserving particle structures against preparation damage. From 36 to 79 particles within each cross section were exposed near enough to midplane for optical microscopy of kernel, buffer, and coating behavior. The microstructural analysis focused on kernel swelling and porosity, buffer densification and fracture, debonding between the buffer and inner pyrolytic carbon (IPyC) layers, and fractures in the IPyC and SiC layers. Three basic particle morphologies were established according to the extent of bonding between the buffer and IPyC layers: complete debonding along the interface (Type A), no debonding along the interface (Type B), and partial debonding (Type AB). These basic morphologies were subdivided according to whether the buffer stayed intact or fractured. The resulting six characteristic morphologies were used to classify particles within each cross section, but no spatial patterns were clearly observed in any of the cross-sectional morphology maps. Although positions of particle types appeared random within compacts, examining a total of 931 classified particles allowed other relationships among morphological types to be established.

  17. El Título de Ingeniero Agrónomo

    Directory of Open Access Journals (Sweden)

    Universidad Nacional de Colombia Facultad de Agronomía

    1941-08-01

    Full Text Available Como es ocurrencia frecuente la controversia sobre la propiedad académica o el derecho que asiste a los profesionales que han cursado estudios superiores de Agronomía para usar el título de Ingenieros Agrónomos, es procedente aclarar este punto sobre todo hoy que en Colombia la carrera agronómica está ocupando destacada posición en el panorama social y económico del país.

  18. Rapid Staphylococcus aureus agr Type Determination by a Novel Multiplex Real-Time Quantitative PCR Assay

    OpenAIRE

    Francois, Patrice; Koessler, Thibaud; Huyghe, Antoine; Harbarth, Stephan; Bento, Manuela; Lew, Daniel; Etienne, Jérôme; Pittet, Didier; Schrenzel, Jacques

    2006-01-01

    The accessory gene regulator (agr) is a crucial regulatory component of Staphylococcus aureus involved in the control of bacterial virulence factor expression. We developed a real-time multiplex quantitative PCR assay for the rapid determination of S. aureus agr type. This assay represents a rapid and affordable alternative to sequence-based strategies for assessing relevant epidemiological information.

  19. Rapid Staphylococcus aureus agr type determination by a novel multiplex real-time quantitative PCR assay.

    Science.gov (United States)

    Francois, Patrice; Koessler, Thibaud; Huyghe, Antoine; Harbarth, Stephan; Bento, Manuela; Lew, Daniel; Etienne, Jérôme; Pittet, Didier; Schrenzel, Jacques

    2006-05-01

    The accessory gene regulator (agr) is a crucial regulatory component of Staphylococcus aureus involved in the control of bacterial virulence factor expression. We developed a real-time multiplex quantitative PCR assay for the rapid determination of S. aureus agr type. This assay represents a rapid and affordable alternative to sequence-based strategies for assessing relevant epidemiological information. PMID:16672433

  20. Rapid Staphylococcus aureus agr Type Determination by a Novel Multiplex Real-Time Quantitative PCR Assay

    Science.gov (United States)

    Francois, Patrice; Koessler, Thibaud; Huyghe, Antoine; Harbarth, Stephan; Bento, Manuela; Lew, Daniel; Etienne, Jérôme; Pittet, Didier; Schrenzel, Jacques

    2006-01-01

    The accessory gene regulator (agr) is a crucial regulatory component of Staphylococcus aureus involved in the control of bacterial virulence factor expression. We developed a real-time multiplex quantitative PCR assay for the rapid determination of S. aureus agr type. This assay represents a rapid and affordable alternative to sequence-based strategies for assessing relevant epidemiological information. PMID:16672433

  1. de cultivos agrícolas, en la agricultura urbana

    Directory of Open Access Journals (Sweden)

    Marcial A. Méndez F.

    2006-01-01

    Full Text Available El uso de las aguas residuales se presenta como una de las fuentes alternativas para el riego en la agricultura urbana. Esto entraña un conjunto de interrogantes en cuanto a su manejo y las posibles afectaciones que ellas puedan ocasionar a los frutos cosechados, al suelo y al medio ambiente. Las informaciones que se presentan, son solo los primeros resultados de los estudios introductorios hasta ahora realizados. Las aguas residuales del afluente Luyanó en el municipio Arroyo Naranjo, de acuerdo con los análisis realizados, se clasifican como aguas de baja contaminación (según los valores DBO5 y DQO obtenidos. Estas aguas, además, toxicológicamente no constituyen un riesgo de contaminación ni para el suelo ni para el medio ambiente, aunque no deben utilizarse sin tratamiento previo en cultivos de consumo directo, dada la carga microbiana que presentan. Las parcelas experimentales que se establecieron con cultivos de zanahoria, rábano y flor del Marigold, mostraron en las primeras cosechas que es posible alcanzar en ellas altos rendimientos agrícolas, dado el valor fertilizante de estas aguas residuales. Los resultados de la cosecha del rábano, según análisis bacteriológicos realizados, no mostraron ningún tipo de contaminación. El suelo y el entorno agrícola, tampoco presentaron afectaciones.

  2. AGR2 is associated with gastric cancer progression and poor survival

    Science.gov (United States)

    ZHANG, JUN; JIN, YONGMING; XU, SHAONAN; ZHENG, JIAYIN; ZHANG, QI; WANG, YUANYU; CHEN, JINPING; HUANG, YAZENG; HE, XUJUN; ZHAO, ZHONGSHENG

    2016-01-01

    Anterior gradient protein 2 (AGR2) has been reported as a novel biomarker with a potential oncogenic role. However, its association with the prognosis and survival rate of gastric cancer (GC) has not yet been determined. Therefore, the present study aimed to examine the expression and prognostic significance of AGR2 in patients with GC. Immunohistochemistry was used to analyze AGR2 and cathepsin D (CTSD) protein expression in 436 clinicopathologically characterized GC cases and 92 noncancerous tissue samples. AGR2 and CTSD expression were both elevated in GC lesions compared with noncancerous tissues. In 204/436 (46.8%) GC patients, high expression of AGR2 was positively correlated with the expression of CTSD (r=0.577, P<0.01). Furthermore, several clinicopathological parameters were significantly associated with AGR2 expression level, including tumor size, depth of invasion and TNM stage (P<0.05). Using Kaplan-Meier survival analysis, it was determined that the mean survival time of patients with low levels of AGR2 expression was significantly longer than those with high ARG2 expression (in stages I, II and III; P<0.05). For stage IV disease, no significant difference in survival time was identified. Multivariate survival analysis demonstrated that AGR2 was an independent prognostic factor and was associated in the progression of GC. The findings of the present study indicate that AGR2 expression is significantly associated with location and size of GC, depth of invasion, TNM stage, lymphatic metastasis, vessel invasion, distant metastasis, Lauren's classification, high CTSD expression and poor prognosis. Thus, AGR2 may be a novel GC marker and may present a potential therapeutic target for GC. PMID:26998125

  3. AGR-3/4 Irradiation Test Train Disassembly and Component Metrology First Look Report

    Energy Technology Data Exchange (ETDEWEB)

    Stempien, John Dennis [Idaho National Lab. (INL), Idaho Falls, ID (United States); Rice, Francine Joyce [Idaho National Lab. (INL), Idaho Falls, ID (United States); Harp, Jason Michael [Idaho National Lab. (INL), Idaho Falls, ID (United States); Winston, Philip Lon [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-03-01

    The AGR-3/4 experiment was designed to study fission product transport within graphitic matrix material and nuclear-grade graphite. To this end, this experiment consisted of 12 capsules, each fueled with 4 compacts containing UCO TRISO particles as driver fuel and 20 UCO designed-to-fail (DTF) fuel particles in each compact. The DTF fuel was fabricated with a thin pyrocarbon layer which was intended to fail during irradiation and provide a source of fission products. These fission products could then migrate through the compact and into the surrounding concentric rings of graphitic matrix material and/or nuclear graphite. Through post-irradiation examination (PIE) of the rings (including physical sampling and gamma scanning) fission product concentration profiles within the rings can be determined. These data can be used to elucidate fission product transport parameters (e.g. diffusion coefficients within the test materials) which will be used to inform and refine models of fission product transport. After irradiation in the Advanced Test Reactor (ATR) had been completed in April 2014, the AGR-3/4 experiment was shipped to the Hot Fuel Examination Facility (HFEF) at the Materials and Fuels Complex (MFC) for inspection, disassembly, and metrology. The AGR-3/4 test train was received at MFC in two separate shipments between February and April 2015. Visual examinations of the test train exterior did not indicate dimensional distortion, and only two small discolored areas were observed at the bottom of Capsules 8 and 9. No corresponding discoloration was found on the inside of these capsules, however. Prior to disassembly, the two test train sections were subject to analysis via the Precision Gamma Scanner (PGS), which did not indicate that any gross fuel relocation had occurred. A series of specialized tools (including clamps, cutters, and drills) had been designed and fabricated in order to carry out test train disassembly and recovery of capsule components (graphite

  4. A Survey of the Fuel Cycles Operated in the United Kingdom

    International Nuclear Information System (INIS)

    (a) The natural uranium/ magnox fuel cycle. The United Kingdom have chosen the natural uranium graphite-moderated gas-cooled reactor as the basis of their nuclear power programme. They have operated the reactors at Calder Hall and Chapelcross for seven years; the Berkeley and Bradwell reactors of the CEGB are now operating, and reactors at seven other sites are under construction or planned. The fuel for these reactors is designed and manufactured at the U.K.A.E.A. Springfields factory and then transported to the reactor site for loading. After irradiation and discharge the fuel is transported to the U.K.A.E.A. site at Windscale for separation of uranium and plutonium from fission products. The paper outlines the UK experience of design and manufacture of fuel, re actor operation, transport of irradiated fuel and subsequent processing of the fuel. Mention is made of the behaviour of fuel in a reactor and alternative charging and discharging programmes, the subject is further elaborated in another paper. (b) Reactors using enriched fuels. The UK are developing an advanced gas-cooled reactor (AGR), the prototype reactor of which came on power in 1963. The fuel is manufactured from enriched uranium oxide canned in stainless steel and it will be reprocessed through a ''head-end'' which will be added to the Windscale Magnox separation plant. The enriched uranium for the AGR is produced in the UK Diffusion Plant at Capenhurst. An alternative to enriched uranium oxide as a fuel is plutonium-enriched natural-uranium oxide. The paper outlines the experience in production of oxide fuel for AGR, the operating experience with the reactor so far and the plans for reprocessing the fuel. The alternative use of a plutonium fuel is considered and the effects of this on costs and the fuel cycle. Finally the paper outlines the place of Magnox and AGR reactors in the UK power programme. (author)

  5. Nacionalismos e reforma agrária nos anos 50

    Directory of Open Access Journals (Sweden)

    Moreira Vânia Maria Losada

    1998-01-01

    Full Text Available O artigo visa recuperar os elementos fundamentais do ideário nacionalista durante a década de 1950, destacando a centralidade do conceito de desenvolvimento auto-sustentado. A diversidade política e ideológica do movimento nacionalista é problematizada através da análise de duas correntes preponderantes do período em foco: o nacional-desenvolvimentismo, de caráter liberal, e o nacionalismo econômico, isto é, a vertente defendida pelas esquerdas. Finalmente, é focalizado a importância da reforma agrária dentro do projeto social defendido sobretudo pelos nacionalistas econômicos, enquanto fator indispensável a uma industrialização com cidadania.

  6. Planificación de Maquinaria Agrícola

    Directory of Open Access Journals (Sweden)

    Alvarez Cardona Alberto

    1979-06-01

    Full Text Available Se entiende por planificación agrícola el conjunto de técnicas que permiten ver con anticipación suficiente la cantidad de maquinaria, tanto fuentes de potencia como implementos que serán requeridos para realizar un trabajo específico en un tiempo determinado; ó la cantidad de trabajo específico que podrá realizar un equipo con características ya definidas a través de un tiempo determinado; se analizan también bajo este concepto de planificación aquellos sistemas que permiten evaluar, controlar y ajustar la planificación propuesta a las circunstancias reales una vez iniciada ésta.

  7. Comparison of fission product release predictions using PARFUME with results from the AGR-1 irradiation experiment

    Energy Technology Data Exchange (ETDEWEB)

    Blaise Collin

    2014-09-01

    This report documents comparisons between post-irradiation examination measurements and model predictions of silver (Ag), cesium (Cs), and strontium (Sr) release from selected tristructural isotropic (TRISO) fuel particles and compacts during the first irradiation test of the Advanced Gas Reactor program that occurred from December 2006 to November 2009 in the Advanced Test Reactor (ATR) at Idaho National Laboratory (INL). The modeling was performed using the particle fuel model computer code PARFUME (PARticle FUel ModEl) developed at INL. PARFUME is an advanced gas-cooled reactor fuel performance modeling and analysis code (Miller 2009). It has been developed as an integrated mechanistic code that evaluates the thermal, mechanical, and physico-chemical behavior of fuel particles during irradiation to determine the failure probability of a population of fuel particles given the particle-to-particle statistical variations in physical dimensions and material properties that arise from the fuel fabrication process, accounting for all viable mechanisms that can lead to particle failure. The code also determines the diffusion of fission products from the fuel through the particle coating layers, and through the fuel matrix to the coolant boundary. The subsequent release of fission products is calculated at the compact level (release of fission products from the compact) but it can be assessed at the particle level by adjusting the diffusivity in the fuel matrix to very high values. Furthermore, the diffusivity of each layer can be individually set to a high value (typically 10-6 m2/s) to simulate a failed layer with no capability of fission product retention. In this study, the comparison to PIE focused on fission product release and because of the lack of failure in the irradiation, the probability of particle failure was not calculated. During the AGR-1 irradiation campaign, the fuel kernel produced and released fission products, which migrated through the successive

  8. Radionuclide compositions of spent fuel and high level waste from commercial nuclear reactors

    International Nuclear Information System (INIS)

    This report provides information on radionuclide compositions of spent fuel and high level waste produced during reprocessing. The reactor types considered are Magnox, AGR, PWR and CFR. The activities of the radionuclides are calculated using the FISPIN code. The results are presented in a form suitable for radioactive waste management calculations. (author)

  9. HTR-2014 Paper Comparison of fission product release predictions using PARFUME with results from the AGR-1 irradiation experiment

    Energy Technology Data Exchange (ETDEWEB)

    Blaise Collin

    2001-10-01

    The PARFUME (PARticle FUel ModEl) code was used to predict fission product release from tristructural isotropic (TRISO) coated fuel particles and compacts during the first irradiation experiment (AGR-1) of the Advanced Gas Reactor Fuel Development and Qualification program. The PARFUME model for the AGR-1 experiment used the fuel compact volume average temperature for each of the 620 days of irradiation to calculate the release of fission products silver, cesium, and strontium from a representative particle for a select number of AGR-1 compacts. Post-irradiation examination (PIE) measurements provided data on release of fission products from fuel compacts and fuel particles, and retention of fission products in the compacts outside of the SiC layer. PARFUME-predicted fractional release of these fission products was determined and compared to the PIE measurements. Results show an overall over-prediction of the fractional release of cesium by PARFUME. For particles with failed silicon carbide (SiC) layers, the over-prediction is by a factor of about two, corresponding to an over-estimation of the diffusivity in uranium oxycarbide (UCO) by a factor of about 100. For intact particles, whose release is much lower, the over-prediction is by an average of about an order of magnitude, which could additionally be attributed to an over-estimated diffusivity in SiC by about 30%. The release of strontium from intact particles is also over-estimated by PARFUME, which also points towards an over-estimated diffusivity of strontium in either SiC or UCO, or possibly both. The measured strontium fractional release from intact particles varied considerably from compact to compact, making it difficult to assess the effective over-estimation of the diffusivities. Furthermore, the release of strontium from particles with failed SiC is difficult to observe experimentally due to the release from intact particles, preventing any conclusions to be made on the accuracy or validity of the

  10. Comparison of fission product release predictions using PARFUME with results from the AGR-1 safety tests

    Energy Technology Data Exchange (ETDEWEB)

    Blaise Collin

    2014-09-01

    Safety tests were conducted on fourteen fuel compacts from AGR-1, the first irradiation experiment of the Advanced Gas Reactor (AGR) Fuel Development and Qualification program, at temperatures ranging from 1600 to 1800°C to determine fission product release at temperatures that bound reactor accident conditions. The PARFUME (PARticle FUel ModEl) code was used to predict the release of fission products silver, cesium, strontium, and krypton from fuel compacts containing tristructural isotropic (TRISO) coated particles during the safety tests, and the predicted values were compared with experimental results. Preliminary comparisons between PARFUME predictions and post-irradiation examination (PIE) results of the safety tests show different trends in the prediction of the fractional release depending on the species, and it leads to different conclusions regarding the diffusivities used in the modeling of fission product transport in TRISO-coated particles: • For silver, the diffusivity in silicon carbide (SiC) might be over-estimated by a factor of at least 102 to 103 at 1600°C and 1700°C, and at least 10 to 102 at 1800°C. The diffusivity of silver in uranium oxy-carbide (UCO) might also be over-estimated, but the available data are insufficient to allow definitive conclusions to be drawn. • For cesium, the diffusivity in UCO might be over-estimated by a factor of at least 102 to 103 at 1600°C, 105 at 1700°C, and 103 at 1800°C. The diffusivity of cesium in SiC might also over-estimated, by a factor of 10 at 1600°C and 103 at 1700°C, based upon the comparisons between calculated and measured release fractions from intact particles. There is no available estimate at 1800°C since all the compacts heated up at 1800°C contain particles with failed SiC layers whose release dominates the release from intact particles. • For strontium, the diffusivity in SiC might be over-estimated by a factor of 10 to 102 at 1600 and 1700°C, and 102 to 103 at 1800°C. These

  11. a Dosimetry Assessment for the Core Restraint of AN Advanced Gas Cooled Reactor

    Science.gov (United States)

    Thornton, D. A.; Allen, D. A.; Tyrrell, R. J.; Meese, T. C.; Huggon, A. P.; Whiley, G. S.; Mossop, J. R.

    2009-08-01

    This paper describes calculations of neutron damage rates within the core restraint structures of Advanced Gas Cooled Reactors (AGRs). Using advanced features of the Monte Carlo radiation transport code MCBEND, and neutron source data from core follow calculations performed with the reactor physics code PANTHER, a detailed model of the reactor cores of two of British Energy's AGR power plants has been developed for this purpose. Because there are no relevant neutron fluence measurements directly supporting this assessment, results of benchmark comparisons and successful validation of MCBEND for Magnox reactors have been used to estimate systematic and random uncertainties on the predictions. In particular, it has been necessary to address the known under-prediction of lower energy fast neutron responses associated with the penetration of large thicknesses of graphite.

  12. AGR-2 Irradiated Test Train Preliminary Inspection and Disassembly First Look

    Energy Technology Data Exchange (ETDEWEB)

    Ploger, Scott [Idaho National Lab. (INL), Idaho Falls, ID (United States); Demkowciz, Paul [Idaho National Lab. (INL), Idaho Falls, ID (United States); Harp, Jason [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-05-01

    The AGR 2 irradiation experiment began in June 2010 and was completed in October 2013. The test train was shipped to the Materials and Fuels Complex in July 2014 for post-irradiation examination (PIE). The first PIE activities included nondestructive examination of the test train, followed by disassembly of the test train and individual capsules and detailed inspection of the capsule contents, including the fuel compacts and their graphite fuel holders. Dimensional metrology was then performed on the compacts, graphite holders, and steel capsule shells. AGR 2 disassembly and metrology were performed with the same equipment used successfully on AGR 1 test train components. Gamma spectrometry of the intact test train gave a preliminary look at the condition of the interior components. No evidence of damage to compacts or graphite components was evident from the isotopic and gross gamma scans. Disassembly of the AGR 2 test train and its capsules was conducted rapidly and efficiently by employing techniques refined during the AGR 1 disassembly campaign. Only one major difficulty was encountered while separating the test train into capsules when thermocouples (of larger diameter than used in AGR 1) and gas lines jammed inside the through tubes of the upper capsules, which required new tooling for extraction. Disassembly of individual capsules was straightforward with only a few minor complications. On the whole, AGR 2 capsule structural components appeared less embrittled than their AGR 1 counterparts. Compacts from AGR 2 Capsules 2, 3, 5, and 6 were in very good condition upon removal. Only relatively minor damage or markings were visible using high resolution photographic inspection. Compact dimensional measurements indicated radial shrinkage between 0.8 to 1.7%, with the greatest shrinkage observed on Capsule 2 compacts that were irradiated at higher temperature. Length shrinkage ranged from 0.1 to 0.9%, with by far the lowest axial shrinkage on Capsule 3 compacts

  13. Survival of Listeria monocytogenes in Soil Requires AgrA-Mediated Regulation.

    Science.gov (United States)

    Vivant, Anne-Laure; Garmyn, Dominique; Gal, Laurent; Hartmann, Alain; Piveteau, Pascal

    2015-08-01

    In a recent paper, we demonstrated that inactivation of the Agr system affects the patterns of survival of Listeria monocytogenes (A.-L. Vivant, D. Garmyn, L. Gal, and P. Piveteau, Front Cell Infect Microbiol 4:160, http://dx.doi.org/10.3389/fcimb.2014.00160). In this study, we investigated whether the Agr-mediated response is triggered during adaptation in soil, and we compared survival patterns in a set of 10 soils. The fate of the parental strain L. monocytogenes L9 (a rifampin-resistant mutant of L. monocytogenes EGD-e) and that of a ΔagrA deletion mutant were compared in a collection of 10 soil microcosms. The ΔagrA mutant displayed significantly reduced survival in these biotic soil microcosms, and differential transcriptome analyses showed large alterations of the transcriptome when AgrA was not functional, while the variations in the transcriptomes between the wild type and the ΔagrA deletion mutant were modest under abiotic conditions. Indeed, in biotic soil environments, 578 protein-coding genes and an extensive repertoire of noncoding RNAs (ncRNAs) were differentially transcribed. The transcription of genes coding for proteins involved in cell envelope and cellular processes, including the phosphotransferase system and ABC transporters, and proteins involved in resistance to antimicrobial peptides was affected. Under sterilized soil conditions, the differences were limited to 86 genes and 29 ncRNAs. These results suggest that the response regulator AgrA of the Agr communication system plays important roles during the saprophytic life of L. monocytogenes in soil. PMID:26002901

  14. Staphylococcus aureus interaction with phospholipid vesicles--a new method to accurately determine accessory gene regulator (agr activity.

    Directory of Open Access Journals (Sweden)

    Maisem Laabei

    Full Text Available The staphylococcal accessory gene regulatory (agr operon is a well-characterised global regulatory element that is important in the control of virulence gene expression for Staphylococcus aureus, a major human pathogen. Hence, accurate and sensitive measurement of Agr activity is central in understanding the virulence potential of Staphylococcus aureus, especially in the context of Agr dysfunction, which has been linked with persistent bacteraemia and reduced susceptibility to glycopeptide antibiotics. Agr function is typically measured using a synergistic haemolysis CAMP assay, which is believe to report on the level of expression of one of the translated products of the agr locus, delta toxin. In this study we develop a vesicle lysis test (VLT that is specific to small amphipathic peptides, most notably delta and Phenol Soluble Modulin (PSM toxins. To determine the accuracy of this VLT method in assaying Agr activity, we compared it to the CAMP assay using 89 clinical Staphylococcus aureus isolates. Of the 89 isolates, 16 were designated as having dysfunctional Agr systems by the CAMP assay, whereas only three were designated as such by VLT. Molecular analysis demonstrated that of these 16 isolates, the 13 designated as having a functional Agr system by VLT transcribed rnaIII and secreted delta toxin, demonstrating they have a functional Agr system despite the results of the CAMP assay. The agr locus of all 16 isolates was sequenced, and only the 3 designated as having a dysfunctional Agr system contained mutations, explaining their Agr dysfunction. Given the potentially important link between Agr dysfunction and clinical outcome, we have developed an assay that determines this more accurately than the conventional CAMP assay.

  15. N Reactor

    Data.gov (United States)

    Federal Laboratory Consortium — The last of Hanfordqaodmasdkwaspemas7ajkqlsmdqpakldnzsdflss nine plutonium production reactors to be built was the N Reactor.This reactor was called a dual purpose...

  16. The cefazolin inoculum effect in methicillin-susceptible Staphylococcus aureus blood isolates: their association with dysfunctional accessory gene regulator (agr).

    Science.gov (United States)

    Wi, Yu Mi; Park, Young Kyoung; Moon, Chisook; Ryu, Seong Yeol; Lee, Hyuck; Ki, Hyun Kyun; Cheong, Hae Suk; Son, Jun Seong; Lee, Jin Seo; Kwon, Ki Tae; Kim, June Myong; Ha, Young Eun; Kang, Cheol In; Ko, Kwan Soo; Chung, Doo Ryeon; Peck, Kyong Ran; Song, Jae-Hoon

    2015-11-01

    We evaluated the clinical significance of the cefazolin inoculum effect (CIE) in methicillin-susceptible Staphylococcus aureus (MSSA) isolates. In total, 146 isolates were recovered from patients with MSSA bacteremia at 9 hospitals in Korea. The CIE was observed in 16 MSSA isolates, and while type A was the only detected β-lactamase in MSSA isolates exhibiting the CIE, no strains expressing type B, C, or D β-lactamases exhibited this effect. The CIE was only observed in agr group III and I isolates and was significantly more common in isolates with agr dysfunction than in those with functional agr (P<0.001). Even among isolates producing type A β-lactamase, the CIE was also prevalent in isolates with dysfunctional agr than in isolates with functional agr (P=0.025). This study demonstrates an association between the CIE of MSSA isolates and agr dysfunction, in addition to those between the CIE and type A β-lactamase.

  17. INITIAL IRRADIATION OF THE FIRST ADVANCED GAS REACTOR FUEL DEVELOPMENT AND QUALIFICATION EXPERIMENT IN THE ADVANCED TEST REACTOR

    Energy Technology Data Exchange (ETDEWEB)

    S. Blaine Grover; David A. Petti

    2007-09-01

    The United States Department of Energy’s Advanced Gas Reactor (AGR) Fuel Development and Qualification Program will be irradiating eight separate tri-isotopic (TRISO) particle fuel (in compact form) experiments in the Advanced Test Reactor (ATR) located at the Idaho National Laboratory (INL). These irradiations and fuel development are being accomplished to support development of the next generation reactors in the United States. The ATR has a long history of irradiation testing in support of reactor development and the INL has been designated as the United States Department of Energy’s lead laboratory for nuclear energy development. The ATR is one of the world’s premiere test reactors for performing long term, high flux, and/or large volume irradiation test programs. These AGR fuel experiments will be irradiated over the next ten years to demonstrate and qualify new particle fuel for use in high temperature gas reactors. The experiments, which will each consist of six separate capsules, will be irradiated in an inert sweep gas atmosphere with individual on-line temperature monitoring and control for each capsule. The swept gas will also have on-line fission product monitoring to track performance of the fuel in each individual capsule during irradiation.

  18. Supercritical CO2 direct cycle Gas Fast Reactor (SC-GFR) concept.

    Energy Technology Data Exchange (ETDEWEB)

    Wright, Steven Alan; Parma, Edward J., Jr.; Suo-Anttila, Ahti Jorma (Computational Engineering Analysis, Albuquerque, NM); Al Rashdan, Ahmad (Texas A& M University, College Station, TX); Tsvetkov, Pavel Valeryevich (Texas A& M University, College Station, TX); Vernon, Milton E.; Fleming, Darryn D.; Rochau, Gary Eugene

    2011-05-01

    This report describes the supercritical carbon dioxide (S-CO{sub 2}) direct cycle gas fast reactor (SC-GFR) concept. The SC-GFR reactor concept was developed to determine the feasibility of a right size reactor (RSR) type concept using S-CO{sub 2} as the working fluid in a direct cycle fast reactor. Scoping analyses were performed for a 200 to 400 MWth reactor and an S-CO{sub 2} Brayton cycle. Although a significant amount of work is still required, this type of reactor concept maintains some potentially significant advantages over ideal gas-cooled systems and liquid metal-cooled systems. The analyses presented in this report show that a relatively small long-life reactor core could be developed that maintains decay heat removal by natural circulation. The concept is based largely on the Advanced Gas Reactor (AGR) commercial power plants operated in the United Kingdom and other GFR concepts.

  19. Qual o custo governamental do seguro agrícola?

    Directory of Open Access Journals (Sweden)

    Vitor Augusto Ozaki

    2013-03-01

    Full Text Available Para 2011, estavam previstos R$ 570 milhões ao Programa de Subvenção ao Prêmio do Seguro Rural (PSR, mas apenas R$ 253,4 milhões foram alocados ao Programa em função de contingenciamentos do governo. Apesar disso, foi possível segurar 5,6 milhões de hectares com uma importância segurada de R$ 7,3 bilhões. Mas qual deveria ser o volume de recursos direcionados ao PSR para que todo o crédito de custeio das lavouras pudesse ser coberto pelo mercado segurador? O estudo apresenta uma metodologia para calcular qual deve ser o valor orçamentário médio do PSR para cobrir cem por cento do custeio das lavouras. Para 2011, os resultados sugerem que o volume de recursos deveria ter sido quatro vezes maior do que o valor empenhado. Ademais, os resultados foram desagregados por estado e por culturas agrícolas. A importância do PSR para a massificação do seguro rural é indiscutível. Porém, além dos recursos do PSR estarem subdimensionados, outro problema ameaça a continuidade do Programa. Pelo terceiro ano consecutivo, o PSR tem sofrido graves contingenciamentos que têm impactado negativamente o mercado. Portanto, fica evidente a necessidade de maior esforço do governo federal em ampliar os recursos da subvenção e destiná-los única e integralmente ao PSR.

  20. Saúde e mercado de trabalho no Brasil: diferenciais entre ocupados agrícolas e não agrícolas

    Directory of Open Access Journals (Sweden)

    Alexandre Gori Maia

    2010-12-01

    Full Text Available Este trabalho analisa as diferenças no estado de saúde entre e dentro dos grupos de ocupados agrícolas e não agrícolas no Brasil, utilizando medidas de autoavaliação do estado de saúde captadas no suplemento da PNAD (Pesquisa Nacional por Amostra de Domicílios de 2008. As análises baseiam-se na composição socioeconômica dos ocupados agrícolas e não agrícolas e nas estimativas de equações simultâneas para captar as relações não lineares entre saúde, renda e jornada de trabalho. Um dos pressupostos do trabalho é que a baixa prevalência de saudáveis entre os ocupados agrícolas estaria associada, sobretudo, à composição socioeconômica desse grupo, e não à maior insalubridade a que os ocupados das atividades agrícolas estariam submetidos em condições socioeconômicas semelhantes às dos não agrícolas. Analogamente, a desigualdade no estado de saúde seria menor entre os ocupados agrícolas devido aos hábitos mais homogêneos, não só no que se refere ao tipo de atividade, mas também em relação à qualidade de vida e ao acesso a uma série de itens de consumo, típico das localidades menos desenvolvidas onde as atividades agrícolas prevalecem.This paper analyzes differences of health conditions between and within agricultural and non-agricultural workers in Brazil. Self-reported health measures of the Health Supplement of Pesquisa Nacional por Amostra de Domicílios (PNAD, from 2008, are used. Results are based on the description of the socioeconomic characteristics of each group of employees and on estimates of a simultaneous equation to measure non-linear relations between health conditions, income and work hours. The main hypothesis is that the lower prevalence of workers with good health among agricultural workers is mainly due to socioeconomic characteristics of this group and not necessarily to higher insalubrious conditions that such workers would be submitted to in equivalent socioeconomic conditions

  1. 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.

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

    International Nuclear Information System (INIS)

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

  3. Diseño de tractores agrícolas en México

    Directory of Open Access Journals (Sweden)

    Jaime Cuauhtémoc Negrete

    2012-01-01

    Full Text Available Este trabajo tiene por objetivo describir los antecedentes de diseño de los tractores agrícolas en México, ya que según varios autores es necesario que los países en desarrollo cuenten con fuentes de potencia agrícola adecuadas a la situación de su agricultura, razón por el cual es necesaria la revisión de literatura presente para que a partir de esta se pueda partir para un diseño de tractor que tenga en cuenta las características necesarias de potencia, facilidad de manejo y mantenimiento, precio accesible, durabilidad, entre otras características las cuales deben ser de acuerdo a las necesidades del agricultor en lo que respecta a sus propiedades promedio y sistemas de producción agrícola en el país.

  4. Biotecnología agrícola

    Directory of Open Access Journals (Sweden)

    Melgarejo, Paloma

    2014-08-01

    Full Text Available The domestication of plants can be considered as the first genetic manipulation of living organisms and it is associated with the origin of agriculture, and represents the major contribution of biotechnology to the development of mankind. The challenges the agricultural sector faces in the coming decades are population growth and the increasing demand for raw materials for food, feed, as well as the consumer preferences, environmental and legal aspects, and the overall globalisation of the economy. The agricultural biotechnology applications will undoubtedly play a role in meeting these challenges. Spain has competent scientific groups devoted to basic and applied research, with a wide knowledge on agricultural biotechnology. The transfer of the business sector needs to the scientific field, coordinating the R&D companies and research groups from universities and public research organisms is an objective to be attained in the future.La domesticación de plantas, primera manipulación genética de los organismos vivos y origen de la Agricultura, representa la mayor contribución de la biotecnología al desarrollo de la humanidad. Los retos a superar en las próximas décadas para el sector agrario están determinados por el aumento demográfico y la demanda de materias primas para alimentación humana y animal, por las preferencias en el consumo, por aspectos medioambientales y legales, y por la globalización de la economía. Las aplicaciones de la biotecnología agrícola van a jugar un papel incuestionable en el logro de estos retos. Nuestro país posee unos buenos grupos en investigación básica y aplicada, con amplios conocimientos de la agrobiotecnología. El traslado de las necesidades del sector empresarial a la investigación, coordinando los departamentos de I+D+I de las empresas y los grupos de investigación de las universidades y organismos públicos de investigación es una finalidad a conseguir en el futuro.

  5. Reactor safeguards

    CERN Document Server

    Russell, Charles R

    2013-01-01

    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

  6. 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

  7. AGR-1 Irradiated Test Train Preliminary Inspection and Disassembly First Look

    Energy Technology Data Exchange (ETDEWEB)

    Paul Demkowicz; Lance Cole; Scott Ploger; Philip Winston; Binh Pham; Michael Abbott

    2011-01-01

    The AGR-1 irradiation experiment ended on November 6, 2009, after 620 effective full power days in the Advanced Test Reactor, achieving a peak burnup of 19.6% FIMA. The test train was shipped to the Materials and Fuels Complex in March 2010 for post-irradiation examination. The first PIE activities included non-destructive examination of the test train, followed by disassembly of the test train and individual capsules and detailed inspection of the capsule contents, including the fuel compacts and the graphite fuel holders. Dimensional measurements of the compacts, graphite holders, and steel capsules shells were performed using a custom vision measurement system (for outer diameters and lengths) and conventional bore gauges (for inner diameters). Gamma spectrometry of the intact test train gave a preliminary look at the condition of the interior components. No evidence of damage to compacts or graphite components was evident from the isotopic and gross gamma scans. Neutron radiography of the intact Capsule 2 showed a high degree of detail of interior components and confirmed the observation that there was no major damage to the capsule. Disassembly of the capsules was initiated using procedures qualified during out-of-cell mockup testing. Difficulties were encountered during capsule disassembly due to irradiation-induced changes in some of the capsule components’ properties, including embrittled niobium and molybdenum parts that were susceptible to fracture and swelling of the graphite fuel holders that affected their removal from the capsule shells. This required various improvised modifications to the disassembly procedure to avoid damage to the fuel compacts. Ultimately the capsule disassembly was successful and only one compact from Capsule 4 (out of 72 total in the test train) sustained damage during the disassembly process, along with the associated graphite holder. The compacts were generally in very good condition upon removal. Only relatively minor

  8. Irradiation of the First Advanced Gas Reactor Fuel Development and Qualification Experiment in the Advanced Test Reactor

    Energy Technology Data Exchange (ETDEWEB)

    S. Blaine Grover; David A. Petti

    2008-10-01

    The United States Department of Energy’s Advanced Gas Reactor (AGR) Fuel Development and Qualification Program will be irradiating eight separate tri-isotopic (TRISO) particle fuel (in compact form) experiments in the Advanced Test Reactor (ATR) located at the Idaho National Laboratory (INL). These irradiations and fuel development are being accomplished to support development of the next generation reactors in the United States. The ATR has a long history of irradiation testing in support of reactor development and the INL has been designated as the United States Department of Energy’s lead laboratory for nuclear energy development. These AGR fuel experiments will be irradiated over the next ten years to demonstrate and qualify new particle fuel for use in high temperature gas reactors. The experiments, which will each consist of six separate capsules, will be irradiated in an inert sweep gas atmosphere with individual on-line temperature monitoring and control for each capsule. The swept gas will also have on-line fission product monitoring to track performance of the fuel in each individual capsule during irradiation. The design of the first experiment (designated AGR-1) was completed in 2005, and the fabrication and assembly of the test train as well as the support systems and fission product monitoring system that monitor and control the experiment during irradiation were completed in September 2006. The experiment was inserted in the ATR in December 2006, and is serving as a shakedown test of the multi-capsule experiment design that will be used in the subsequent irradiations as well as a test of the early variants of the fuel produced under this program. The experiment test train as well as the monitoring, control, and data collection systems are discussed and the status of the experiment is provided.

  9. Research reactors

    International Nuclear Information System (INIS)

    This article proposes an overview of research reactors, i.e. nuclear reactors of less than 100 MW. Generally, these reactors are used as neutron generators for basic research in matter sciences and for technological research as a support to power reactors. The author proposes an overview of the general design of research reactors in terms of core size, of number of fissions, of neutron flow, of neutron space distribution. He outlines that this design is a compromise between a compact enough core, a sufficient experiment volume, and high enough power densities without affecting neutron performance or its experimental use. The author evokes the safety framework (same regulations as for power reactors, more constraining measures after Fukushima, international bodies). He presents the main characteristics and operation of the two families which represent almost all research reactors; firstly, heavy water reactors (photos, drawings and figures illustrate different examples); and secondly light water moderated and cooled reactors with a distinction between open core pool reactors like Melusine and Triton, pool reactors with containment, experimental fast breeder reactors (Rapsodie, the Russian BOR 60, the Chinese CEFR). The author describes the main uses of research reactors: basic research, applied and technological research, safety tests, production of radio-isotopes for medicine and industry, analysis of elements present under the form of traces at very low concentrations, non destructive testing, doping of silicon mono-crystalline ingots. The author then discusses the relationship between research reactors and non proliferation, and finally evokes perspectives (decrease of the number of research reactors in the world, the Jules Horowitz project)

  10. Reactor physics and reactor computations

    International Nuclear Information System (INIS)

    Mathematical methods and computer calculations for nuclear and thermonuclear reactor kinetics, reactor physics, neutron transport theory, core lattice parameters, waste treatment by transmutation, breeding, nuclear and thermonuclear fuels are the main interests of the conference

  11. Colorado's AgrAbility Project's Effects on KASA and Practice Changes with Agricultural Producers and Professionals

    Science.gov (United States)

    Fetsch, Robert J.; Jackman, Danielle M.

    2015-01-01

    Disability rates resulting from work-related injuries remain steadily high among farmers and ranchers. To address the gap in services within this population, USDA implemented AgrAbility nationally. Using part of Bennett's hierarchical model, the current study evaluated the KASA and practice change levels of 401 farmers and ranchers and compared…

  12. FABRICATION PROCESS AND PRODUCT QUALITY IMPROVEMENTS IN ADVANCED GAS REACTOR UCO KERNELS

    Energy Technology Data Exchange (ETDEWEB)

    Charles M Barnes

    2008-09-01

    A major element of the Advanced Gas Reactor (AGR) program is developing fuel fabrication processes to produce high quality uranium-containing kernels, TRISO-coated particles and fuel compacts needed for planned irradiation tests. The goals of the AGR program also include developing the fabrication technology to mass produce this fuel at low cost. Kernels for the first AGR test (“AGR-1) consisted of uranium oxycarbide (UCO) microspheres that werre produced by an internal gelation process followed by high temperature steps tot convert the UO3 + C “green” microspheres to first UO2 + C and then UO2 + UCx. The high temperature steps also densified the kernels. Babcock and Wilcox (B&W) fabricated UCO kernels for the AGR-1 irradiation experiment, which went into the Advance Test Reactor (ATR) at Idaho National Laboratory in December 2006. An evaluation of the kernel process following AGR-1 kernel production led to several recommendations to improve the fabrication process. These recommendations included testing alternative methods of dispersing carbon during broth preparation, evaluating the method of broth mixing, optimizing the broth chemistry, optimizing sintering conditions, and demonstrating fabrication of larger diameter UCO kernels needed for the second AGR irradiation test. Based on these recommendations and requirements, a test program was defined and performed. Certain portions of the test program were performed by Oak Ridge National Laboratory (ORNL), while tests at larger scale were performed by B&W. The tests at B&W have demonstrated improvements in both kernel properties and process operation. Changes in the form of carbon black used and the method of mixing the carbon prior to forming kernels led to improvements in the phase distribution in the sintered kernels, greater consistency in kernel properties, a reduction in forming run time, and simplifications to the forming process. Process parameter variation tests in both forming and sintering steps led

  13. A review of control rod calibration methods for irradiated AGRs

    International Nuclear Information System (INIS)

    Methods of calibrating control rods with particular reference to irradiated CAGR are surveyed. Some systematic spatial effects are found and an estimate of their magnitude made. It is concluded that control rod oscillation provides a promising method of calibrating rods at power which is as yet untried on CAGR. Also the rod drop using inverse kinetics provides a rod calibration but spatial effects may be large and these would be difficult to correct theoretically. The pulsed neutron technique provides a calibration route with small errors due to spatial effects provided a suitable K-tube can be developed. The xenon transient method is shown to have statial effects which have not needed consideration in earlier reactors but which in CAGR would need very careful evaluation. (author)

  14. Modelling 3D crack propagation in ageing graphite bricks of Advanced Gas-Cooled Reactor Power Plant

    International Nuclear Information System (INIS)

    In this paper, crack propagation in Advanced Gas-cooled Reactor (AGR) graphite bricks with ageing properties is studied using the eXtended Finite Element Method (X-FEM). A parametric study for crack propagation, including the influence of different initial crack shapes and propagation criteria, is conducted. The results obtained in the benchmark study show that the crack paths from X-FEM are similar to the experimental ones. The accuracy of the strain energy release rate computation in a heterogeneous material is also evaluated using a finite difference approach. Planar and non-planar 3D crack growth simulations are presented to demonstrate the robustness and the versatility of the method utilized. Finally, this work contributes to the better understanding of crack propagation behaviour in AGR graphite bricks and so contributes to the extension of the AGR plant lifetimes in the UK by reducing uncertainties. (author)

  15. AGR3 in Breast Cancer: Prognostic Impact and Suitable Serum-Based Biomarker for Early Cancer Detection

    Science.gov (United States)

    Garczyk, Stefan; von Stillfried, Saskia; Antonopoulos, Wiebke; Hartmann, Arndt; Schrauder, Michael G.; Fasching, Peter A.; Anzeneder, Tobias; Tannapfel, Andrea; Ergönenc, Yavuz; Knüchel, Ruth

    2015-01-01

    Blood-based early detection of breast cancer has recently gained novel momentum, as liquid biopsy diagnostics is a fast emerging field. In this study, we aimed to identify secreted proteins which are up-regulated both in tumour tissue and serum samples of breast cancer patients compared to normal tissue and sera. Based on two independent tissue cohorts (n = 75 and n = 229) and one serum cohort (n = 80) of human breast cancer and healthy serum samples, we characterised AGR3 as a novel potential biomarker both for breast cancer prognosis and early breast cancer detection from blood. AGR3 expression in breast tumours is significantly associated with oestrogen receptor α (P<0.001) and lower tumour grade (P<0.01). Interestingly, AGR3 protein expression correlates with unfavourable outcome in low (G1) and intermediate (G2) grade breast tumours (multivariate hazard ratio: 2.186, 95% CI: 1.008-4.740, P<0.05) indicating an independent prognostic impact. In sera analysed by ELISA technique, AGR3 protein concentration was significantly (P<0.001) elevated in samples from breast cancer patients (n = 40, mainly low stage tumours) compared to healthy controls (n = 40). To develop a suitable biomarker panel for early breast cancer detection, we measured AGR2 protein in human serum samples in parallel. The combined AGR3/AGR2 biomarker panel achieved a sensitivity of 64.5% and a specificity of 89.5% as shown by receiver operating characteristic (ROC) curve statistics. Thus our data clearly show the potential usability of AGR3 and AGR2 as biomarkers for blood-based early detection of human breast cancer. PMID:25875093

  16. Aptitud relativa agrícola del municipio de Tuxpan, Nayarit, utilizando el modelo Almagra del Sistema MicroLEIS

    OpenAIRE

    José López García; Diego de la Rosa Acosta; José Irán Bojórquez Serrano

    2006-01-01

    Se realizó la evaluación de tierras para uso agrícola en la llanura fluviomarina dentro del municipio de Tuxpan, Nayarit, con base en un levantamiento de suelos semidetallado. Se evaluó la aptitud relativa agrícola, mediante la modificación del modelo Almagra del sistema MicroLEIS 4.1, el cual permite definir la aptitud relativa agrícola, de lo cual resulta el Almagra-Tuxpan, al crearse una base de datos con las condiciones específicas de esta región. Con base en el modelo Almagra...

  17. Reactor building

    International Nuclear Information System (INIS)

    The whole reactor building is accommodated in a shaft and is sealed level with the earth's surface by a building ceiling, which provides protection against penetration due to external effects. The building ceiling is supported on walls of the reactor building, which line the shaft and transfer the vertical components of forces to the foundations. The thickness of the walls is designed to withstand horizontal pressure waves in the floor. The building ceiling has an opening above the reactor, which must be closed by cover plates. Operating equipment for the reactor can be situated above the building ceiling. (orig./HP)

  18. Some aspects of the dynamics of AGR gas circulators

    International Nuclear Information System (INIS)

    The various types of vibration found on the gas circulators of an advanced gas-cooled reactor (Hinkley Point 'B' design) are categorized and described briefly. Those due to rotor unbalance or its lack of straightness are considered in detail where it is attempted to highlight certain aspects of the dynamic behaviour which are considered of particular importance to designers either because of the results themselves or the techniques used in obtaining them; for example, the practical utilization of the finite-element technique in the mathematical modelling process. One interesting aspect relates to the interaction between the circulator rotor modes of vibration and those of the over-hung impeller. Another deals with the condition of a permanent rotor bend near the impeller as the source of vibration excitation. Various states of rotor unbalance have also been simulated. The work led to general conclusions which were utilized in resolving specific questions related to the balancing of refurbished circulators; it also increased the understanding of their dynamic behaviour thus leading to more operational confidence. (author)

  19. A History of Dosimetry for the Advanced Gas-cooled Reactors

    OpenAIRE

    Shaw Simon; Thornton Dean

    2016-01-01

    This paper presents a summary of the methods used in the first ∼40 years of AGR neutron dosimetry and nuclear heating calculations, and the influence of the earlier Magnox reactor dosimetry programme. While the current state-of-the-art Monte Carlo methods are extremely powerful they still require very careful consideration of the quality of the input data, nuclear data validation and variance reduction techniques; in particular, this paper examines the difficulties in assuring the adequate co...

  20. AGR-2 Data Qualification Report for ATR Cycles 151B-2, 152A, 152B, 153A, 153B and 154A

    Energy Technology Data Exchange (ETDEWEB)

    Binh T. Pham; Jeffrey J. Einerson

    2013-09-01

    This report documents the data qualification status of AGR-2 fuel irradiation experimental data from Advanced Test Reactor (ATR) Cycles 152A, 152B, 153A, 153B, and 154A, as recorded in the Nuclear Data Management and Analysis System (NDMAS). The AGR-2 data streams addressed include thermocouple (TC) temperatures, sweep gas data (flow rate, pressure, and moisture content), and fission product monitoring system (FPMS) data for each of the six capsules in the experiment. A total of 13,400,520 every minute instantaneous TC and sweep gas data records were received and processed by NDMAS for this period. Of these data, 8,911,791 records (66.5% of the total) were determined to be Qualified based on NDMAS accuracy testing and data validity assessment. For temperature, there were 4,266,081 records (74% of the total TC data) that were Failed due to TC instrument failures. For sweep gas flows, there were 222,648 gas flow records (2.91% of the flow data) that were Failed. The inlet gas flow failures due to gas flow cross-talk and leakage problems that occurred after Cycle 150A were corrected by using the same gas mixture in all six capsules and the Leadout. For FPMS data, NDMAS received and processed preliminary release rate and release-to-birth rate ratio (R/B) data for three reactor cycles (Cycles 149B, 150B, and 151A) . This data consists of 45,983 release rate records and 45,235 R/B records for the 12 radionuclides reported. The qualification status of these FPMS data has been set to In Process until receipt of Quality Assurance-approved data generator reports. All of the above data have been processed and tested using a SAS®-based enterprise application software system, stored in a secure Structured Query Language database, made available on the NDMAS Web portal (http://ndmas.inl.gov), and approved by the INL STIM for release to both internal and appropriate external Very High Temperature Reactor Program participants.

  1. Corrosion studies of thermally sensitised AGR fuel element brace in pH7 and pH9.2 borate solutions

    International Nuclear Information System (INIS)

    Brace and cladding of AGR fuel elements sensitised in reactor are susceptible to intergranular and crevice corrosion, which may initiate in the pH7 borate pond storage environment of CEGB/SSEB stations. This report considers the benefit in corrosion control that is provided by raising the pond solution pH to 9.2, whilst maintaining the boron level at 1250 gm-3. The greater corrosion protection provided by pH9.2 solution compared to the pH7 borate solution is demonstrated by a series of tests with non-active laboratory sensitised brace samples exposed to solutions dosed with chloride or sulphate in order to promote localised corrosion. The corrosion tests undertaken consisted of 5000 hour immersions at 320C and shorter term electrochemically monitored experiments (rest potential, impedance, anodic current) generally conducted at 220C. The pH9.2 solution effectively inhibited the initiation of crevice and intergranular corrosion in the presence of low levels of chloride and sulphate, whereas the pH7 solution did not always do so. However, the pH9.2 solution, dosed with 40 gm-3 chloride, failed to suppress fully crevice corrosion initiated in unborated 40 gm-3 chloride solution at 220C. Fluoride is not deleterious at low levels ∼ 10 gm-3 in the borate solutions. The significant improvement in corrosion control demonstrated for the change from pH7 to pH9.2 borate solution on laboratory sensitised brace samples should ideally be confirmed using complete irradiated AGR fuel elements. (U.K.)

  2. La Ingeniería Agrícola en el País

    Directory of Open Access Journals (Sweden)

    Bustamante M. Hellodoro

    1985-12-01

    Full Text Available Es sumamente difícil situar en la historia, el origen de la Ingeniería Agrícola, aunque podría remontarse al propio origen de la tierra, de las plantas y de las aguas. La Ingeniería Agrícola está ocupando un campo de acción que se ha desarrollado a pesar de las limitaciones que le ofrece el mismo desarrollo del país y al escepticismo sin fundamento de algunos pregoneros del pesimismo nacional; le corresponde enfrentar además hoy al cáncer del desempleo y a la falta de oportunidad para demostrar al país que la inversión hecha por el estado en la formación de estos profesionales es productiva.

  3. Desempleo entre los jornaleros agrícolas, un fenómeno emergente

    Directory of Open Access Journals (Sweden)

    Antonieta Barrón

    2013-01-01

    Full Text Available Este artículo tiene como propósito presentar un fenómeno no planteado en el estudio de mercados de trabajo agrícolas y empleo rural, se cuestiona la definición de desem- pleo, y se plantea cómo esta definición, asumida por el inegi, se aplica en los mercados de trabajo formales pero no en los no formales, los agrícolas. Se hacen comparaciones entre los niveles nacional y rural para concluir con los estudios de caso que refuerzan la tesis inicial, el aumento del desempleo en los mercados de trabajo rurales. A lo largo del trabajo se resaltan las diferencias por sexo y se conlcuye que el desempleo rural afecta más a las mujeres que los hombres, fenómeno contrario al de nivel nacional.

  4. Diseño de un sistema de riego agrícola controlado a distancia

    OpenAIRE

    Monge Álvarez, Jesús

    2015-01-01

    En este TFM se plantea el diseño de un prototipo que constituya una innovación incremental de una de las tecnologías de riego agrícola más recientes: los pívots de regadío. Los dos objetivos que se pretenden conseguir con este prototipo son: un uso más eficiente del agua empleada en el regadío agrícola y evitar largos desplazamientos para la simple puesta en marcha o monitorización del pívot. Su parte hardware está basada en la placa computadora Raspberry Pi junto con la placa Custard Pi 2...

  5. Redescubriendo El suelo: Su importancia ecológica y agrícola

    Directory of Open Access Journals (Sweden)

    Noé Manuel Montaño

    2016-10-01

    Full Text Available Redescubriendo el suelo: su importancia ecológica y agrícola es un libro muy completo, actualizado y sin duda será de consulta obligada para quienes hacen investigación edafológica y como material elemental para los cursos de pre- y posgrado de suelo y materias afines, tanto en México como en América Latina.

  6. Estudio bibliométrico de la Revista Centro Agrícola, Cuba

    OpenAIRE

    Paz Enrique, Luis Ernesto; Peralta González, María Josefa; Hernández Alfonso, Eduardo Alejandro

    2016-01-01

    The analysis of references of serials publications are appropriate tools for making decisions to improve the quality of the journals. This article raises as objectives to examine the references of the articles published by the Centro Agrícola Journal of the Universidad Central ''Marta Abreu'' de Las Villas, Cuba. This article characterizes the publication and the references employed by the journal. Five unidimensionals indicators are applied: most referenced year, most referenced document typ...

  7. Vancomycin modifies the expression of the agr system in multidrug-resistant Staphylococcus aureus clinical isolates

    Directory of Open Access Journals (Sweden)

    Vicenta eCázares-Domínguez

    2015-05-01

    Full Text Available Staphylococcus aureus is an opportunistic pathogen that colonizes human hosts and causes a wide variety of diseases. Two interacting regulatory systems called agr (accessory gene regulator and sar (staphylococcal accessory regulator are involved in the regulation of virulence factors. The aim of this study was to evaluate the effect of vancomycin on hld and spa gene expression during the exponential and post-exponential growth phases in multidrug resistant (MDR S. aureus. Methods. Antibiotic susceptibility was evaluated by the standard microdilution method. The phylogenetic profile was obtained by pulsed-field gel electrophoresis. Polymorphisms of agr and SCCmec were analyzed by multiplex polymerase chain reaction. The expression levels of hld and spa were analyzed by reverse transcription-PCR. An enzyme-linked immunosorbent assay assay was performed to detect protein A, and biofilm formation was analyzed via crystal violet staining. Results. In total, 60.60% (20/33 of S. aureus clinical isolates were MDR. Half (10/20 of the MDR S. aureus isolates were distributed in subcluster 10, with > 90% similarity among them. In the isolates of this subcluster, a high prevalence (100% for the agrII and the cassette SCCmec II polymorphisms was found. Our data showed significant increases in hld expression during the post-exponential phase in the presence and absence of vancomycin. Significant increases in spa expression, protein A production and biofilm formation were observed during the post-exponential phase when the MDR S. aureus isolates were challenged with vancomycin. Conclusion. The polymorphism agrII, which is associated with nosocomial isolates, was the most prevalent polymorphism in MDR S. aureus. Additionally, under our study conditions, vancomycin modified hld and spa expression in these clinical isolates. Therefore, vancomycin may regulate alternative systems that jointly participate in the regulation of these virulence factors.

  8. Chitinase expression in Listeria monocytogenes is positively regulated by the Agr system

    DEFF Research Database (Denmark)

    Paspaliari, Dafni Katerina; Mollerup, Maria Storm; Kallipolitis, Birgitte H.;

    2014-01-01

    The food-borne pathogen Listeria monocytogenes encodes two chitinases, ChiA and ChiB, which allow the bacterium to hydrolyze chitin, the second most abundant polysaccharide in nature. Intriguingly, despite the absence of chitin in human and mammalian hosts, both of the chitinases have been deemed....... Our results highlight a previously unrecognized role of the agr system and suggest that autoinducer-based regulation of chitinolytic systems may be more commonplace than previously thought....

  9. Human oral isolate Lactobacillus fermentum AGR1487 reduces intestinal barrier integrity by increasing the turnover of microtubules in Caco-2 cells.

    Directory of Open Access Journals (Sweden)

    Rachel C Anderson

    Full Text Available Lactobacillus fermentum is found in fermented foods and thought to be harmless. In vivo and clinical studies indicate that some L. fermentum strains have beneficial properties, particularly for gastrointestinal health. However, L. fermentum AGR1487 decreases trans-epithelial electrical resistance (TEER, a measure of intestinal barrier integrity. The hypothesis was that L. fermentum AGR1487 decreases the expression of intestinal cell tight junction genes and proteins, thereby reducing barrier integrity. Transcriptomic and proteomic analyses of Caco-2 cells (model of human intestinal epithelial cells treated with L. fermentum AGR1487 were used to obtain a global view of the effect of the bacterium on intestinal epithelial cells. Specific functional characteristics by which L. fermentum AGR1487 reduces intestinal barrier integrity were examined using confocal microscopy, cell cycle progression and adherence bioassays. The effects of TEER-enhancing L. fermentum AGR1485 were investigated for comparison. L. fermentum AGR1487 did not alter the expression of Caco-2 cell tight junction genes (compared to L. fermentum AGR1485 and tight junction proteins were not able to be detected. However, L. fermentum AGR1487 increased the expression levels of seven tubulin genes and the abundance of three microtubule-associated proteins, which have been linked to tight junction disassembly. Additionally, Caco-2 cells treated with L. fermentum AGR1487 did not have defined and uniform borders of zona occludens 2 around each cell, unlike control or AGR1485 treated cells. L. fermentum AGR1487 cells were required for the negative effect on barrier integrity (bacterial supernatant did not cause a decrease in TEER, suggesting that a physical interaction may be necessary. Increased adherence of L. fermentum AGR1487 to Caco-2 cells (compared to L. fermentum AGR1485 was likely to facilitate this cell-to-cell interaction. These findings illustrate that bacterial strains of the

  10. Anterior Gradient 2 (AGR2) Induced Epidermal Growth Factor Receptor (EGFR) Signaling Is Essential for Murine Pancreatitis-Associated Tissue Regeneration

    Science.gov (United States)

    Wodziak, Dariusz; Dong, Aiwen; Basin, Michael F.; Lowe, Anson W.

    2016-01-01

    A recently published study identified Anterior Gradient 2 (AGR2) as a regulator of EGFR signaling by promoting receptor presentation from the endoplasmic reticulum to the cell surface. AGR2 also promotes tissue regeneration in amphibians and fish. Whether AGR2-induced EGFR signaling is essential for tissue regeneration in higher vertebrates was evaluated using a well-characterized murine model for pancreatitis. The impact of AGR2 expression and EGFR signaling on tissue regeneration was evaluated using the caerulein-induced pancreatitis mouse model. EGFR signaling and cell proliferation were examined in the context of the AGR2-/- null mouse or with the EGFR-specific tyrosine kinase inhibitor, AG1478. In addition, the Hippo signaling coactivator YAP1 was evaluated in the context of AGR2 expression during pancreatitis. Pancreatitis-induced AGR2 expression enabled EGFR translocation to the plasma membrane, the initiation of cell signaling, and cell proliferation. EGFR signaling and tissue regeneration were partially inhibited by the tyrosine kinase inhibitor AG1478, but absent in the AGR2-/- null mouse. AG1478-treated and AGR2-/- null mice with pancreatitis died whereas all wild-type controls recovered. YAP1 activation was also dependent on pancreatitis-induced AGR2 expression. AGR2-induced EGFR signaling was essential for tissue regeneration and recovery from pancreatitis. The results establish tissue regeneration as a major function of AGR2-induced EGFR signaling in adult higher vertebrates. Enhanced AGR2 expression and EGFR signaling are also universally present in human pancreatic cancer, which support a linkage between tissue injury, regeneration, and cancer pathogenesis. PMID:27764193

  11. Completing the Design of the Advanced Gas Reactor Fuel Development and Qualification Experiments for Irradiation in the Advanced Test Reactor

    Energy Technology Data Exchange (ETDEWEB)

    S. Blaine Grover

    2006-10-01

    The United States Department of Energy’s Advanced Gas Reactor (AGR) Fuel Development and Qualification Program will be irradiating eight separate low enriched uranium (LEU) oxycarbide (UCO) tri-isotopic (TRISO) particle fuel (in compact form) experiments in the Advanced Test Reactor (ATR) located at the newly formed Idaho National Laboratory (INL). These irradiations and fuel development are being accomplished to support development of the next generation reactors in the United States. The ATR has a long history of irradiation testing in support of reactor development and the INL has been designated as the new United States Department of Energy’s lead laboratory for nuclear energy development. The ATR is one of the world’s premiere test reactors for performing long term, high flux, and/or large volume irradiation test programs. These AGR fuel experiments will be irradiated over the next ten years to demonstrate and qualify new particle fuel for use in high temperature gas reactors. The goals of the irradiation experiments are to provide irradiation performance data to support fuel process development, to qualify fuel for normal operating conditions, to support development and validation of fuel performance and fission product transport models and codes, and to provide irradiated fuel and materials for post irradiation examination (PIE) and safety testing. The experiments, which will each consist of six separate capsules, will be irradiated in an inert sweep gas atmosphere with individual on-line temperature monitoring and control for each capsule. The swept gas will also have on-line fission product monitoring to track performance of the fuel in each individual capsule during irradiation.

  12. Desarrollo y perspectiva de la Ingeniería Agrícola

    Directory of Open Access Journals (Sweden)

    Julio E. Ospina Mejía

    2011-02-01

    Full Text Available La Ingeniería Agrícola es la rama de la ingeniería orientada a dar respuesta a los problemas que plantea la agricultura moderna, mediante la aplicación de principios de las ciencias naturales y las matemáticas, procurando la conservación y el aumento del potencial del suelo, la producción de alimentos de calidad, el mantenimiento del medio ambiente y la dignificación del hombre rural. El objetivo de la ingeniería agrícola es la generación y aplicación de conocimientos científicos y tecnológicos de la ingeniería a la producción agropecuaria y otros biosistemas orientados a las áreas de adecuación de tierras, maquinaria agrícola, manejo de recursos hídricos, construcciones rurales, manejo poscosecha y procesamiento de producto agropecuarios, con criterios de sostenibilidad y competitividad.

  13. Compact Reactor

    International Nuclear Information System (INIS)

    Weyl's Gauge Principle of 1929 has been used to establish Weyl's Quantum Principle (WQP) that requires that the Weyl scale factor should be unity. It has been shown that the WQP requires the following: quantum mechanics must be used to determine system states; the electrostatic potential must be non-singular and quantified; interactions between particles with different electric charges (i.e. electron and proton) do not obey Newton's Third Law at sub-nuclear separations, and nuclear particles may be much different than expected using the standard model. The above WQP requirements lead to a potential fusion reactor wherein deuterium nuclei are preferentially fused into helium nuclei. Because the deuterium nuclei are preferentially fused into helium nuclei at temperatures and energies lower than specified by the standard model there is no harmful radiation as a byproduct of this fusion process. Therefore, a reactor using this reaction does not need any shielding to contain such radiation. The energy released from each reaction and the absence of shielding makes the deuterium-plus-deuterium-to-helium (DDH) reactor very compact when compared to other reactors, both fission and fusion types. Moreover, the potential energy output per reactor weight and the absence of harmful radiation makes the DDH reactor an ideal candidate for space power. The logic is summarized by which the WQP requires the above conditions that make the prediction of DDH possible. The details of the DDH reaction will be presented along with the specifics of why the DDH reactor may be made to cause two deuterium nuclei to preferentially fuse to a helium nucleus. The presentation will also indicate the calculations needed to predict the reactor temperature as a function of fuel loading, reactor size, and desired output and will include the progress achieved to date

  14. Status of national gas cooled reactor programmes

    International Nuclear Information System (INIS)

    This report has been compiled as a central source of summary-level information on the present status of High Temperature Gas-Cooled Reactor (HTGR) programmes in the world and on future plans for the continued development and deployment of HTGRs. Most of the information concerns the programmes in the United States, Germany, Japan and the Soviet Union, countries that have had large programmes related to HTGR technology for several years. Summary-level information is also provided in the report on HTGR-related activities in several other countries who either have an increasing interest in the technology and/or who are performing some development efforts related to HTGR technology. The report contains a summary-level update on the MAGNOX and AGR programmes. This is the twelfth issue of the document, the first of which was issued in March, 1979. The report has been prepared in the IAEA Nuclear Power Technology Development Section. Figs and tabs

  15. NEUTRONIC REACTOR

    Science.gov (United States)

    Anderson, H.L.

    1960-09-20

    A nuclear reactor is described comprising fissionable material dispersed in graphite blocks, helium filling the voids of the blocks and the spaces therebetween, and means other than the helium in thermal conductive contact with the graphite for removing heat.

  16. 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.

  17. 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)

  18. NUCLEAR REACTOR

    Science.gov (United States)

    Anderson, C.R.

    1962-07-24

    A fluidized bed nuclear reactor and a method of operating such a reactor are described. In the design means are provided for flowing a liquid moderator upwardly through the center of a bed of pellets of a nentron-fissionable material at such a rate as to obtain particulate fluidization while constraining the lower pontion of the bed into a conical shape. A smooth circulation of particles rising in the center and falling at the outside of the bed is thereby established. (AEC)

  19. Nuclear reactor

    International Nuclear Information System (INIS)

    In order to reduce neutron embrittlement of the pressue vessel of an LWR, blanked off elements are fitted at the edge of the reactor core, with the same dimensions as the fuel elements. They are parallel to each other, and to the edge of the reactor taking the place of fuel rods, and are plates of neutron-absorbing material (stainless steel, boron steel, borated Al). (HP)

  20. Project WAGR: The UK demonstration project for power reactor decommissioning - removing the core and looking to completion

    Energy Technology Data Exchange (ETDEWEB)

    Benest, T. G. [United Kingdom Atomic Energy Authority, Headquarters, London (United Kingdom)

    2003-07-01

    The United Kingdom Atomic Energy Authority (UKAEA) has built and operated a wide range of nuclear facilities since the late 1940's. UKAEA's present mission is to restore the environment of these facilities in a safe and environmentally responsible manner. This restoration includes the decommissioning of a number of redundant research and power reactors, one of which is the Windscale Advanced Gas-cooled Reactor (WAGR). Following shut down, UKAEA decided to continue the prototype function of the reactor into the decommissioning phase to develop dismantling techniques and establish waste routes. The reactor core and pressure vessel are now being dismantled in a programme of 10 campaigns, seven of which have been completed since 1998. It is anticipated that the current programme will be completed by summer 2005. This paper outlines the history of the reactor, the operation of the waste-processing route, the installed dismantling equipment and the successful completion of the first seven campaigns. This earlier work has been described in a number of publications and conferences, so this paper concentrates on recent work to select and develop cutting equipment to dismantle the core support structures and the pressure vessel. The decommissioning of the Windscale Advance Gas-cooled reactor is being undertaken to demonstrate that a power reactor can be decommissioned shortly after shutdown. The removal of the core and pressure vessel has been broken down into a series of 10 campaigns associated with particular core components. The first 7 campaigns have been successfully completed and the 8., is expected to commence in September 2003 17 months earlier than planned. Dismantling methodologies and tools have been developed specifically for each of these campaigns. Full-scale mock-ups have been used to test the tools, train the operators and assess the duration of operations. However, despite successful trials, operational experience has shown that some of these tools

  1. Listeria monocytogenes differential transcriptome analysis reveals temperature-dependent Agr regulation and suggests overlaps with other regulons.

    Directory of Open Access Journals (Sweden)

    Dominique Garmyn

    Full Text Available Listeria monocytogenes is a ubiquitous, opportunistic pathogenic organism. Environmental adaptation requires constant regulation of gene expression. Among transcriptional regulators, AgrA is part of an auto-induction system. Temperature is an environmental cue critical for in vivo adaptation. In order to investigate how temperature may affect AgrA-dependent transcription, we compared the transcriptomes of the parental strain L. monocytogenes EGD-e and its ΔagrA mutant at the saprophytic temperature of 25°C and in vivo temperature of 37°C. Variations of transcriptome were higher at 37°C than at 25°C. Results suggested that AgrA may be involved in the regulation of nitrogen transport, amino acids, purine and pyrimidine biosynthetic pathways and phage-related functions. Deregulations resulted in a growth advantage at 37°C, but affected salt tolerance. Finally, our results suggest overlaps with PrfA, σB, σH and CodY regulons. These overlaps may suggest that through AgrA, Listeria monocytogenes integrates information on its biotic environment.

  2. Programa computacional para calcular a potência requerida de máquinas e implementos agrícolas

    Directory of Open Access Journals (Sweden)

    Pablo Pereira Corrêa Klaver

    2013-12-01

    Full Text Available O uso de programas computacionais no setor agrícola permite atingir objetivos específicos na área. Dentre esses, um dos mais complexos é a seleção adequada de máquinas e implementos agrícolas visando à otimização de operações agrícolas, devido, principalmente, à grande variedade de equipamentos existentes no mercado e a gama de tarefas e situações de trabalho que estas são submetidas no campo. O objetivo deste trabalho foi desenvolver um programa computacional para calcular a potência requerida de máquinas e implementos agrícolas normalmente utilizados na condução de operações de campo, desde o preparo do solo até as operações de implantação de culturas. Desenvolvido em linguagem PHP, o programa computacional baseia-se na norma ASAE D497.4 - Agricultural Machinery Management Data como referência para desenvolvimento de cálculos. A partir do programa desenvolvido, tornou-se possível a execução de tarefas para cálculos de avaliação da demanda de potência de máquinas e implementos agrícolas de forma simplificada pela internet.

  3. hidráulicos de las máquinas agrícolas

    Directory of Open Access Journals (Sweden)

    Luciano Pérez Sobrevilla

    2006-01-01

    Full Text Available Como parte de las investigaciones que se llevan a cabo en la Universidad Autónoma Chapingo de México, en el Departamento de Ingeniería Mecánica Agrícola (DIMA y en la Universidad Agraria de La Habana, en el Centro de Mecanización Agropecuaria (CEMA, dirigidas al estudio de la Oleohidráulica y fundamentados en los resultados de una investigación, se elaboran recomendaciones sobre la utilización de aceites recuperados y su explotación racional en los sistemas hidráulicos de las máquinas agrícolas, partiendo de que el aceite hidráulico recuperado mostró la misma susceptibilidad a la contaminación que el aceite hidráulico nuevo, durante todo el período de observación. De esta forma y con los resultados encontrados se debe mostrar al usuario los beneficios que pueden significar el uso de aceites reciclados, tanto para su economía como para la reducción de la contaminación del medio ambiente. De acuerdo con lo anterior se pretende: introducir el uso de un equipo de recuperación de aceites hidráulicos en el Laboratorio de Hidráulica y Neumática del DIMA (LAHNDI, para recuperar aceites hidráulicos residuales, mediante un proceso de centrifugación y filtración, para de esta forma reducir el costo de producción de los aceites hidráulicos utilizados en máquinas agrícolas e industriales.

  4. Sistemas de producción agrícola sostenible

    Directory of Open Access Journals (Sweden)

    Róger Martínez Castillo

    2009-01-01

    Full Text Available El desarrollo sostenible se fundamenta en principios éticos, como el respeto y armonía con la naturaleza; valores políticos, como la democracia participativa y equidad social; y normas morales, como racionalidad ambiental. El desarrollo sostenible es igualitario, descentralizado y autogestionario, capaz de satisfacer las necesidades básicas de la población, respetando la diversidad cultural y mejorando la calidad de vida. La agricultura y el desarrollo sostenible se refieren a la necesidad de minimizar la degradación de la tierra agrícola, maximizando a su vez la producción. Este considera el conjunto de las actividades agrícolas, como el manejo de suelos y aguas,el manejo de cultivos y la conservación de la biodiversidad; considerando a su vez el suministro de alimentos y materias primas. La sostenibilidad de los sistemas de producción agrícola se refiere a la capacidad del sistema para mantener su productividad a pesar de las perturbaciones económicas y naturales, externas o internas. La sostenibilidad es función de las características naturales del sistema y las presiones e intervenciones que sufre, así como aquellas intervenciones sociales, económicas y técnicas que se hacen para contrarrestar presiones negativas; destacándose la resiliencia del sistema.

  5. Readiness Review of BWXT for Fabrication of AGR-5/6/7 TRISO Particles

    Energy Technology Data Exchange (ETDEWEB)

    Marshall, Douglas William [Idaho National Lab. (INL), Idaho Falls, ID (United States); Sharp, Michelle Tracy [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-02-01

    INL readiness review assessment of BWXT readiness to commence fabrication of low-enriched TRISO coated fuel particles for the AGR-5/6/7 irradiation experiments. BWXT self-identified equipment issues preventing operation. INL identified two findings. The first was that disposition codes had not been assigned and documented on BWXT forms to ensure that off-specification materials could not be used in the fabrication of TRISO particles. The second was that chemical purity specifications were not reliably passed on to chemical suppliers, which resulted in the receipt of one acetylene cylinder with suspect impurity levels.

  6. Agroecologia: um caminho multidimensional para o desenvolvimento agrário do Litoral Paranaense.

    OpenAIRE

    Borsatto, Ricardo Serra

    2007-01-01

    Ao se estudar o meio agrário do litoral paranaense é fácil constatar as dificuldades que este enfrenta para encontrar um caminho que permita o seu desenvolvimento sustentável. A presente dissertação visa contribuir nas discussões e consequentemente na procura de soluções para este panorama, objetivando conhecer e discutir se o conhecimento gerado pela Agroecologia pode contribuir para o desenvolvimento sustentável do litoral paranaense. Para tanto é utilizada a teoria do pensamento complexo, ...

  7. The Relationship Between Antibiotic Resistance and Agr Type in Methicillin-Resistant Staphylococcus aureus (MRSA Isolated From Burn Wound of Hospitalized Patient in Tehran

    Directory of Open Access Journals (Sweden)

    Mohammad Sadegh Vaziri

    2015-12-01

    Full Text Available Introduction: Staphylococcus aureus is the major cause of hospital and community-acquired infections. This bacterium possesses an accessory gene regulator (agr that plays role in colonization, expression of virulence factors and antibiotic resistance. It’s four major polypeptide with variable sequences lead to at least four agr type in S. aureus.The aim of this study was to determine the relationship between the antibiogram patterns with agr type of clinical S. aureus.Methods: Detection of methicillin-resistant Staphylococcus aureus (MRSA from burn wounds was performed by phenotypic and genotypic profiles. The antibiotics resistance pattern was determined by disk agar diffusion (Tigecycline (TGC, Ciprofloxacin(CIP, Erythromycin(E, Cloxacillin(CX, Clindamycin(CD, Imipenem(IMI, Co-trimoxazole(SXT, Kanamycin(K, Teicoplanin(TEC, Gentamicin(GM, Mupirocin(MUP, Ceftriaxone (CTR. The agr typing by PCR-RFLP method using the Restriction endonuclease ScaI was performed and spss19 was used for data analysis.Results: The total of 76 MRSA isolates was studied. The agr type distribution was 75.6% Type I, 8.2% Type II, 5.4% Type III, 10.8% type IV. The most antibiotics resistant agr type belongs to the type I. There was no significance relationship between every agr type and antibiotics but only a statistically significant association exist between CX, E, CTR, SXT, GM, CIP antibiotics and all agr types (P<0.05.Conclusion: There was no significance relationship between every agr type and antibiotics but significant relationship observed between resistance to some antibiotics with all agr types could be related to the number and source of isolated bacteria or extra use of these antibiotics. By considering that agr locus belongs to upstream genes so it may use the Quorum Sensing (QS system to induce the most drug resistance.

  8. The Choice of thermal reactor systems. A report by the National Nuclear Corporation Limited

    International Nuclear Information System (INIS)

    The report to the Secretary of State in Great Britain by the National Nuclear Corporation following their assessment of the three thermal reactor systems, the AGR, PWR and SGHWR type reactors, which was performed in order to assist in the decision on the choice of thermal reactors for the U.K., is in three parts. Part I is an assessment of the three systems. It comprises: a description of the general method of assessment; a commentary in which are summarised discussions on the most important issues influencing reactor choice, i.e. safety, component failure, operational characteristics, development programme, construction programme; implications for the U.K. industry; costs; and reference design of each system. Part II consists of related questions and answers accompanied by commentaries on public acceptability and views from industry. Part III contains some conclusions including an analysis on the implications of the choices open and a summary of the main features of the assessment. (U.K.)

  9. Trabajadores agrícolas migrantes en Baja California. Vinculación con la migración internacional

    Directory of Open Access Journals (Sweden)

    Ma. Eugenia Anguiano Téllez

    1989-09-01

    Full Text Available En este ensayo los jornaleros agrícolas migrantes son clasificados en dos estratos: el primero, considera la migración internacional, es decir, aquéllos que se internan en Estados Unidos con el propósito de conseguir empleo; y el segundo, corresponde a la migración interna de los trabajadores agrícolas que permanecen en Baja California para laborar en los valles de Mexicali y San Quintín.En este trabajo se señalan las diferencias entre estos dos estratos, tanto de carácter económico como en los niveles de educación; asimismo, se comparan las características de los jornaleros agrícolas migrantes que cruzan a Estados Unidos por Mexicali y por Tijuana, según su actividad económica de procedencia y su expectativa de empleo en los Estados Unidos.

  10. 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.

  11. A Review of the UK Fast Reactor Programme: March 1980

    International Nuclear Information System (INIS)

    Towards the end of 1979 the Government announced a new programme of thermal reactor stations to be built over ten years (totalling 15GW), in addition to the two AGR stations at Torness and Heysham 'B' which had been approved by the previous Government. The first station of the new programme will be based on a Westinghouse PWR, subject to safety clearance and the outcome of a public inquiry, and it is envisaged that the remaining stations of the programme would be split between PWRs and AGRs. The AEA Chairman wrote formally to the Secretary of State for Energy in December 1979, putting forward on behalf of the Electricity Supply Authorities, NNC, BNFL and the AEA a recommended strategy for building the Commercial Demonstration Fast Reactor (CDFR), subject to normal licensing procedure and to public inquiry, so as to ensure that the key options for introducing commercial fast reactors, when required, should remain open. A Government statement is expected during the next few months. Meanwhile the level of effort on fast reactor research and development in the UK has been maintained, the fast reactor remaining the largest of the UKAEA's reactor development projects with expenditure totalling somewhat over £80M per annum. The main feature of the UK fast reactor programme has continued to be the operation of PFR (Sections 2 and 7) which is yielding a wealth of experience and of information relevant to the design of commercial fast reactors. Bum-up of standard driver fuel has reached 6-7% by heavy atoms, while specially enriched lead fuel pins have reached 11 % without failure. An extensive programme of work in the reactor and its associated steam plant was completed in March 1980 and the reactor then started its fifth power run. The fuel reprocessing plant at DNE is being commissioned and has reprocessed some of the spent fuel remaining from the DFR. It will start soon on reprocessing fuel discharged from the PFR. During the year improvements to the design of the future

  12. Staphylococcal superantigen-like genes, ssl5 and ssl8, are positively regulated by Sae and negatively by Agr in the Newman strain.

    Science.gov (United States)

    Pantrangi, Madhulatha; Singh, Vineet K; Wolz, Christiane; Shukla, Sanjay K

    2010-07-01

    Some of the staphylococcal superantigen-like (SSL) proteins SSL5, SSL7, SSL9, and SSL11 act as immunomodulatory proteins in Staphylococcus aureus. However, little is known about their regulatory mechanisms. We determined the expression levels of ssl5 and ssl8 in seven clinically important S. aureus strains and their regulatory mechanisms in the Newman strain, which had the highest ssl5 and ssl8 expression. Independent comparisons of ssl5 or ssl8 coding and upstream sequences in these strains identified multiple haplotypes that did not correlate with the differential expression of ssl5 and ssl8, suggesting the role of additional regulatory elements. Using knockout mutant strains of known S. aureus global regulators such as Agr, Sae, and SigB in the Newman strain, we showed that both ssl5 and ssl8 were induced by Sae and repressed by Agr, suggesting that Sae and Agr are the positive and the negative regulators, respectively, of these two ssl genes. Moreover, we observed upregulation of sae in the agr mutant and upregulation of agr in the sae mutant compared with the isogenic Newman strain, suggesting that the Agr and Sae may be inhibiting each other. The SigB mutation did not affect ssl5 and ssl8 expression, but they were downregulated in the agr/sigB double mutant, indicating that SigB probably acts synergistically with Agr in their upregulation.

  13. Green Fluorescent Protein (GFP-Based Overexpression Screening and Characterization of AgrC, a Receptor Protein of Quorum Sensing in Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Shengdi Fan

    2013-09-01

    Full Text Available Staphylococcus aureus AgrC is an important component of the agr quorum-sensing system. AgrC is a membrane-embedded histidine kinase that is thought to act as a sensor for the recognition of environmental signals and the transduction of signals into the cytoplasm. However, the difficulty of expressing and purifying functional membrane proteins has drastically hindered in-depth understanding of the molecular structures and physiological functions of these proteins. Here, we describe the high-yield expression and purification of AgrC, and analyze its kinase activity. A C-terminal green fluorescent protein (GFP fusion to AgrC served as a reporter for monitoring protein expression levels in real time. Protein expression levels were analyzed by the microscopic assessment of the whole-cell fluorescence. The expressed AgrC-GFP protein with a C-terminal His-tagged was purified using immobilized metal affinity chromatography (IMAC and size exclusion chromatography (SEC at yields of ≥10 mg/L, following optimization. We also assessed the effects of different detergents on membrane solubilization and AgrC kinase activity, and polyoxyethylene-(23-lauryl-ether (Brij-35 was identified as the most suitable detergent. Furthermore, the secondary structural stability of purified AgrC was analyzed using circular dichroism (CD spectroscopy. This study may serve as a general guide for improving the yields of other membrane protein preparations and selecting the appropriate detergent to stabilize membrane proteins for biophysical and biochemical analyses.

  14. Evaluación de residuos agrícolas para la producción del hongo Pleurotus ostreatus

    OpenAIRE

    María Bernarda Ruilova Cueva; Aldo Hernández Monzón

    2014-01-01

    Se caracterizaron los residuos agrícolas de la provincia de Bolívar, Ecuador, desde el punto de vista de su composición físico-química para su empleo en el cultivo del hongo Pleurotus ostreatus. Los residuos agrícolas utilizados fueron: maíz, trigo, cebada, lenteja, bagazo de caña de azúcar y cascarilla de arroz. Se realizaron análisis de: humedad, cenizas, extracto etéreo, proteína, fibra, extracto libre de nitrógeno, fibra detergente neutra, fibra detergente ácida, lignina, celulosa, hemice...

  15. La industria de maquinaria agrícola en Argentina frente a la estructura sectorial del mercado internacional

    OpenAIRE

    Langard, Federico

    2011-01-01

    En el marco de una continua reestructuración de las empresas trasnacionales productoras de maquinaria agrícola a nivel mundial, se observa una, significativa tendencia a la concentración de las mismas y a la oligopolización de la oferta mundial, situación que sin lugar a dudas impacta en nuestro país. El trabajo analiza la dinámica del comercio mundial de maquinaria agrícola, vinculada al desempeño del sector en Argentina. Para ello, se examina el comportamiento de las firmas nacionales y ext...

  16. Huella hídrica de productos agrícolas producidos en la sierra central y comercializados en Lima

    OpenAIRE

    Tito Mallma Capcha; Jesús Mejía Marcacuzco

    2015-01-01

    El objetivo ha sido determinar un modelo para obtener la huella hídrica de los principales productos agrícolas de la sierra central del Perú que son comercializados en los mercados de la ciudad de Lima, para ello se desarrolló un modelo conceptual que determine el requerimiento de agua de los cultivos que junto a los respectivos rendimientos han permitido establecer el contenido de agua virtual de cada producto agrícola expresado en l/kg; con este resultado y la cantidad de producto comercial...

  17. Existe convergência espacial da produtividade agrícola no Brasil?

    Directory of Open Access Journals (Sweden)

    Eduardo Simões de Almeida

    2008-03-01

    Full Text Available Este trabalho analisa a convergência espacial da produtividade agrícola da terra para as microrregiões brasileiras entre o período de 1991 a 2003. Tal análise avalia se há evidências para a existência de convergência beta da produtividade agrícola, controlando-se explicitamente para efeitos espaciais. Para tanto, conduziu-se preliminarmente uma análise exploratória de dados espaciais, que detectou a presença de autocorrelação espacial para a produtividade da terra. Numa etapa posterior, desenvolveram-se modelos econométricos espaciais para a análise da convergência.This work analyzes the convergence of land productivity for Brazilian regions from 1991 to 2003. It evaluates if there is or not beta convergence of the agricultural productivity, controlling explicitly for spatial effects. To do so, an exploratory spatial data analysis was previously implemented and the presence of spatial autocorrelation for the land productivity was detected. In addition, spatial econometric models were developed for the convergence analysis.

  18. Unidades integrales de servicios técnicos de maquinaria agrícola

    Directory of Open Access Journals (Sweden)

    José Suárez

    2011-01-01

    Full Text Available En cada municipio cubano se inició la creación de centros encargados de prestar servicios de mecanización agrícola y asistencia técnica a los productores. Para esto deben disponer de tractores, cosechadoras y otras máquinas e implementos propios, así como de talleres para la reparación y mantenimiento. Cada uno de estos centros será una Unidad Integral de Servicios Técnicos (UIST con el carácter de Unidad Empresarial de Base (UEB subordinada a la Empresa Agropecuaria Municipal. Para constituir estas Unidades fue necesario realizar un estudio de la disponibilidad de talleres, equipamiento, maquinaria y personal de mecanización en las empresas agrícolas y otras entidades productivas de todos los municipios del país, pues ellos constituirán el núcleo fundamental del nuevo sistema. Se ha conformado la propuesta del esquema de funcionamiento de las Unidades, especialmente en lo que respecta a áreas, funciones, equipamiento, modelo de gestión, contratación de servicios, planificación, organización, control, relaciones con otras entidades productivas y de dirección, etc. Estas Unidades se están creando en municipios seleccionados, con vistas a evaluar los resultados, y, teniendo en cuenta las experiencias obtenidas, conformar el programa para extender el sistema a todo el país.

  19. Three-component U-Pu-Th fuel for plutonium irradiation in heavy water reactors

    Directory of Open Access Journals (Sweden)

    Peel Ross

    2016-01-01

    Full Text Available This paper discusses concepts for three-component fuel bundles containing plutonium, uranium and thorium for use in pressurised heavy water reactors, and cases for and against implementation of such a nuclear energy system in the United Kingdom. Heavy water reactors are used extensively in Canada, and are deploying within India and China, whilst the UK is considering the use of heavy water reactors to manage its plutonium inventory of 140 tonnes. The UK heavy water reactor proposal uses a mixed oxide (MOX fuel of plutonium in depleted uranium, within the enhanced CANDU-6 (EC-6 reactor. This work proposes an alternative heterogeneous fuel concept based on the same reactor and CANFLEX fuel bundle, with eight large-diameter fuel elements loaded with natural thorium oxide and 35 small-diameter fuel elements loaded with a MOX of plutonium and reprocessed uranium stocks from UK MAGNOX and AGR reactors. Indicative neutronic calculations suggest that such a fuel would be neutronically feasible. A similar MOX may alternatively be fabricated from reprocessed <5% enriched light water reactor fuel, such as the fuel of the AREVA EPR reactor, to consume newly produced plutonium from reprocessing, similar to the DUPIC (direct use of PWR fuel in CANDU process.

  20. Una aproximación a las características actuales de la mano de obra agrícola en el valle de Mexicali

    Directory of Open Access Journals (Sweden)

    José Ascención Moreno Mena

    1994-07-01

    Full Text Available Este trabajo aborda, de manera sintética, algunas características de la estructura agraria, así como de productores agrícolas del valle de Mexicali. Se presenta un acercamiento a las condiciones en que se desarrolla la mano de obra actual en el sector agrícola del municipio de Mexicali. Para ello se toma como base información primaria obtenida de dos encuestas realizadas durante el periodo 1991-1994; laprimera producto de un muestreo no aleatorio por cuotas aplicada a 150 trabajadores agrícolas del algodón; y la segunda de carácter aleatoria aplicada en 499 viviendas de trabajadores agrícolas en el valle de Mexicali por el Instituto de investigaciones Sociales de la Universidad Autónoma de Baja California y el Programa Nacional de Solidaridad con Jornaleros Agrícolas.

  1. Reactor container

    International Nuclear Information System (INIS)

    A reactor container has a suppression chamber partitioned by concrete side walls, a reactor pedestal and a diaphragm floor. A plurality of partitioning walls are disposed in circumferential direction each at an interval inside the suppression chamber, so that independent chambers in a state being divided into plurality are formed inside the suppression chamber. The partition walls are formed from the bottom portion of the suppression chamber up to the diaphragm floor to isolate pool water in a divided state. Operation platforms are formed above the suppression chamber and connected to an access port. Upon conducting maintenance, inspection or repairing, a pump is disposed in the independent chamber to transfer pool water therein to one or a plurality of other independent chambers to make it vacant. (I.N.)

  2. NEUTRONIC REACTORS

    Science.gov (United States)

    Anderson, J.B.

    1960-01-01

    A reactor is described which comprises a tank, a plurality of coaxial steel sleeves in the tank, a mass of water in the tank, and wire grids in abutting relationship within a plurality of elongated parallel channels within the steel sleeves, the wire being provided with a plurality of bends in the same plane forming adjacent parallel sections between bends, and the sections of adjacent grids being normally disposed relative to each other.

  3. Storage of thermal reactor fuels – Implications for the back end of the fuel cycle in the UK

    OpenAIRE

    Hambley David

    2016-01-01

    Fuel from UK's Advanced Gas-Cooled Reactors (AGRs) is being reprocessed, however reprocessing will cease in 2018 and the strategy for fuel that has not been reprocessed is for it to be placed into wet storage until it can be consigned to a geological disposal facility in around 2080. Although reprocessing of LWR fuel has been undertaken in the UK, and this option is not precluded for current and future LWRs, all utilities planning to operate LWRs are intending to use At-Reactor storage pendin...

  4. The Anterior Gradient Homolog 3 (AGR3) Gene Is Associated with Differentiation and Survival in Ovarian Cancer

    Science.gov (United States)

    King, Erin R.; Tung, Celestine S.; Tsang, Yvonne T.M.; Zu, Zhifei; Lok, Gabriel T.M.; Deavers, Michael T.; Malpica, Anais; Wolf, Judith K.; Lu, Karen H.; Birrer, Michael J.; Mok, Samuel C.; Gershenson, David M.; Wong, Kwong-Kwok

    2011-01-01

    Low-grade serous ovarian carcinoma is believed to arise from serous borderline ovarian tumors, yet the progression from serous borderline tumors to low-grade serous ovarian carcinoma remains poorly understood. The purpose of this study was to identify differentially expressed genes between the two groups. Expression profiles were generated from 6 human ovarian surface epithelia (HOSE), 8 serous borderline ovarian tumors (SBOT), 13 low-grade serous ovarian carcinomas (LG), and 24 high-grade serous ovarian carcinomas (HG). The anterior gradient homolog 3 (AGR3) gene was found to be highly upregulated in serous borderline ovarian tumors; this finding was validated by real-time quantitative RT-PCR, Western blotting, and immunohistochemistry. Anti-AGR3 immunohistochemistry was performed on an additional 56 LG and 103 HG tissues and the results were correlated with clinical data. Expression profiling determined that 1254 genes were differentially expressed (P 10%) of AGR3 positively stained tumor cells were associated with improved longer median survival in both the LG (P = 0.013) and HG (P = 0.008) serous ovarian carcinoma groups. The progression of serous borderline ovarian tumors to low-grade serous ovarian carcinoma may involve the de-differentiation of ciliated cells. AGR3 could serve as a prognostic marker for survival in patients with low-grade and high-grade serous ovarian carcinomas. PMID:21451362

  5. Status of the Combined Third and Fourth NGNP Fuel Irradiations In the Advanced Test Reactor

    Energy Technology Data Exchange (ETDEWEB)

    S. Blaine Grover; David A. Petti; Michael E. Davenport

    2013-07-01

    The United States Department of Energy’s Next Generation Nuclear Plant (NGNP) Advanced Gas Reactor (AGR) Fuel Development and Qualification Program is irradiating up to seven low enriched uranium (LEU) tri-isotopic (TRISO) particle fuel (in compact form) experiments in the Advanced Test Reactor (ATR) located at the Idaho National Laboratory (INL). These irradiations and fuel development are being accomplished to support development of the next generation reactors in the United States. The experiments will be irradiated over the next several years to demonstrate and qualify new TRISO coated particle fuel for use in high temperature gas reactors. The goals of the experiments are to provide irradiation performance data to support fuel process development, to qualify fuel for normal operating conditions, to support development and validation of fuel performance and fission product transport models and codes, and to provide irradiated fuel and materials for post irradiation examination (PIE) and safety testing. The experiments, which will each consist of several independent capsules, will be irradiated in an inert sweep gas atmosphere with individual on-line temperature monitoring and control of each capsule. The sweep gas will also have on-line fission product monitoring on its effluent to track performance of the fuel in each individual capsule during irradiation. The first experiment (designated AGR-1) started irradiation in December 2006 and was completed in November 2009. The second experiment (AGR-2) started irradiation in June 2010 and is currently scheduled to be completed in September 2013. The third and fourth experiments have been combined into a single experiment designated (AGR-3/4), which started its irradiation in December 2011 and is currently scheduled to be completed in April 2014. Since the purpose of this combined experiment is to provide data on fission product migration and retention in the NGNP reactor, the design of this experiment is

  6. Modelo de Precificação de Capital: Segmento de Commodities Agrícola

    Directory of Open Access Journals (Sweden)

    TÁCITO AUGUSTO FARIAS

    2014-12-01

    Full Text Available O objetivo do artigo é a aplicação do modelo de precificação de ativos conhecido na literatura de economia financeira como CAPITAL ASSET PRICING MODEL – MODELO DE PRECIFICAÇÃO DE ATIVOS DE CAPITAL, utilizando como ferramentas os balanços patrimoniais das empresas selecionadas. Brasil Ecodiesel indústria e comercio de biocombustíveis e óleos vegetais s.a. (v-agro e SLC Agrícola s.a. no período relativo ao ano de 2009 e 2010. Resultado fundamental: ambas as empresas no período em estudo apresentaram um beta inferior a 1, ou seja, risco menor que o risco do mercado. Descrevemos alguns resultados estatísticos que mostram o comportamento de ambas as empresas do setor de frigorifico. 

  7. AGR-1 Compact 4-1-1 Post-Irradiation Examination Results

    Energy Technology Data Exchange (ETDEWEB)

    Demkowicz, Paul Andrew [Idaho National Lab. (INL), Idaho Falls, ID (United States); Harp, Jason M. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Winston, Philip L. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Ploger, Scott A. [Idaho National Lab. (INL), Idaho Falls, ID (United States); van Rooyen, Isabella J. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-02-01

    Destructive post-irradiation examination was performed on AGR-1 fuel Compact 4-1-1, which was irradiated to a final compact-average burnup of 19.4% FIMA (fissions per initial metal atom) and a time-average, volume-average temperature of 1072°C. The analysis of this compact focused on characterizing the extent of fission product release from the particles and examining particles to determine the condition of the kernels and coating layers. The work included deconsolidation of the compact and leach-burn-leach analysis, visual inspection and gamma counting of individual particles, metallurgical preparation of selected particles, and examination of particle cross-sections with optical microscopy, electron microscopy, and elemental analysis. Deconsolidation-leach-burn-leach (DLBL) analysis revealed no particles with failed TRISO or failed SiC layers (as indicated by very low uranium inventory in all of the leach solutions). The total fractions of the predicted compact inventories of fission products Ce-144, Cs-134, Cs-137, and Sr-90 that were present in the compact outside of the SiC layers were <2×10-6, based on DLBL data. The Ag-110m fraction in the compact outside the SiC layers was 3.3×10-2, indicating appreciable release of silver through the intact coatings and subsequent retention in the OPyC layers or matrix. The Eu-154 fraction was 2.4×10-4, which is equivalent to the inventory in one average particle, and indicates a small but measurable level of release from the intact coatings. Gamma counting of 61 individual particles indicated no particles with anomalously low fission product retention. The average ratio of measured inventory to calculated inventory was close to a value of 1.0 for several fission product isotopes (Ce-144, Cs-134, and Cs-137), indicating good retention and reasonably good agreement with the predicted inventories. Measured-to-calculated (M/C) activity ratios for fission products Eu-154, Eu-155, Ru-106, Sb

  8. Nuclear research reactors

    International Nuclear Information System (INIS)

    It's presented data about nuclear research reactors in the world, retrieved from the Sien (Nuclear and Energetic Information System) data bank. The information are organized in table forms as follows: research reactors by countries; research reactors by type; research reactors by fuel and research reactors by purpose. (E.G.)

  9. Nuclear reactor

    International Nuclear Information System (INIS)

    A nuclear reactor is described in which the core components, including fuel-rod assemblies, control-rod assemblies, fertile rod-assemblies, and removable shielding assemblies, are supported by a plurality of separate inlet modular units. These units are referred to as inlet module units to distinguish them from the modules of the upper internals of the reactor. The modular units are supported, each removable independently of the others, in liners in the supporting structure for the lower internals of the reactor. The core assemblies are removably supported in integral receptacles or sockets of the modular units. The liners, units, sockets and assemblies have inlet openings for entry of the fluid. The modular units are each removably mounted in the liners with fluid seals interposed between the opening in the liner and inlet module into which the fluid enters in the upper and lower portion of the liner. Each assembly is similarly mounted in a corresponding receptacle with fluid seals interposed between the openings where the fluid enters in the lower portion of the receptacle or fitting closely in these regions. As fluid flows along each core assembly a pressure drop is produced along the fluid so that the fluid which emerges from each core assembly is at a lower pressure than the fluid which enters the core assembly. However because of the seals interposed in the mountings of the units and assemblies the pressures above and below the units and assemblies are balanced and the units are held in the liners and the assemblies are held in the receptacles by their weights as they have a higher specific gravity than the fluid. The low-pressure spaces between each module and its liner and between each core assembly and its module is vented to the low-pressure regions of the vessel to assure that fluid which leaks through the seals does not accumulate and destroy the hydraulic balance

  10. Nuclear reactor physics course for reactor operators

    International Nuclear Information System (INIS)

    The education and training of nuclear reactor operators is important to guarantee the safe operation of present and future nuclear reactors. Therefore, a course on basic 'Nuclear reactor physics' in the initial and continuous training of reactor operators has proven to be indispensable. In most countries, such training also results from the direct request from the safety authorities to assure the high level of competence of the staff in nuclear reactors. The aim of the basic course on 'Nuclear Reactor Physics for reactor operators' is to provide the reactor operators with a basic understanding of the main concepts relevant to nuclear reactors. Seen the education level of the participants, mathematical derivations are simplified and reduced to a minimum, but not completely eliminated

  11. Metodología para evaluar el impacto de la maquinaria agrícola sobre los recursos naturales del medio ambiente

    Directory of Open Access Journals (Sweden)

    Norge Díaz Rodríguez

    2007-01-01

    Full Text Available Se realizó una propuesta de metodología para evaluar el impacto que ejerce la maquinaria agrícola sobre algunos de los recursos naturales del medio ambiente. Durante su explotación la maquinaria agrícola, como unidad energética para el trabajo agrícola, produce un conjunto de impactos negativos sobre el medio en tres direcciones fundamentales: suelo, aire, y agua. A pesar de existir conciencia sobre este problema, no se disponen de herramientas apropiadas para hacer una evaluación certera de la magnitud de estos impactos, lo cual no es una simple tarea.

  12. Contaminación difusa originada por la actividad agrícola de riego, a la escala de la cuenca hidrográfica

    OpenAIRE

    Duarte, António Francisco Canatário

    2006-01-01

    Tese de Doutoramento apresentada à Escuela Técnica Superior de Ingenieros Agrónomos y Montes da Universidad de Córdoba. La creciente preocupación por los problemas ambientales originados por la actividad agrícola, particularmente la contaminación del agua, motiva a repensar la gestión de los sistemas y a definir códigos de buenas practicas agrícolas. Además de la importancia de la monitorización y control de los medios acuáticos que reciben los contaminantes, los modelos de simula...

  13. 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.

  14. 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.

  15. The DOE Advanced Gas Reactor Fuel Development and Qualification Program

    International Nuclear Information System (INIS)

    The high outlet temperatures and high thermal-energy conversion efficiency of modular High Temperature Gas-cooled Reactors (HTGRs) enable an efficient and cost effective integration of the reactor system with non-electricity generation applications, such as process heat and/or hydrogen production, for the many petrochemical and other industrial processes that require temperatures between 300 C and 900 C. The Department of Energy (DOE) has selected the HTGR concept for the Next Generation Nuclear Plant (NGNP) Project as a transformative application of nuclear energy that will demonstrate emissions-free nuclear-assisted electricity, process heat, and hydrogen production, thereby reducing greenhouse-gas emissions and enhancing energy security. The objective of the DOE Advanced Gas Reactor (AGR) Fuel Development and Qualification program is to qualify tristructural isotropic (TRISO)-coated particle fuel for use in HTGRs. The Advanced Gas Reactor Fuel Development and Qualification Program consists of five elements: fuel manufacture, fuel and materials irradiations, post-irradiation examination (PIE) and safety testing, fuel performance modeling, and fission-product transport and source term evaluation. An underlying theme for the fuel development work is the need to develop a more complete, fundamental understanding of the relationship between the fuel fabrication process and key fuel properties, the irradiation and accident safety performance of the fuel, and the release and transport of fission products in the NGNP primary coolant system. An overview of the program and recent progress is presented.

  16. Steam generator materials constraints in UK design gas-cooled reactors

    International Nuclear Information System (INIS)

    A widely reported problem with Magnox-type reactors was the oxidation of carbon steel components in gas circuits and steam generators. The effects of temperature, pressure, gas composition and steel composition on oxidation kinetics have been determined, thus allowing the probabilities of failure of critical components to be predicted for a given set of operating conditions. This risk analysis, coupled with regular inspection of reactor and boiler internals, has allowed continued operation of all U.K. Magnox plant. The Advanced Gas Cooled Reactor (AGR) is a direct development of the Magnox design. The first four AGRs commenced operation in 1976, at Hinkley Point 'B' and at Hunterston 'B'. All known materials problems with the steam generators have been diagnosed and solved by the development of appropriate operational strategies, together with minor plant modifications. Materials constraints no longer impose any restrictions to full load performance from the steam generators throughout the predicted life of the plant. Problems discussed in detail are: 1. oxidation of the 9 Cr - 1 Mo superheater. 2. Stress corrosion of the austenitic superheater. 3. Creep of the transition joints between the 9 Cr - 1 Mo and austenitic sections. With the 9 Cr - 1 Mo oxidation maximum temperature restriction virtually removed and creep constraints properly quantified, boiler operation in now favourably placed. Stress corrosion research has allowed the risk of tube failure to be related to time, temperature, stress and chemistry. As a result, the rigorous 'no wetting' policy has been relaxed for the normally high quality AGR feedwater, and the superheat margin has been reduced to 23 deg. C. This has increased the size of the operating window and reduced the number of expensive, and potentially harmful, plant trips. (author)

  17. Final Assembly and Initial Irradiation of the First Advanced Gas Reactor Fuel Development and Qualification Experiment in the Advanced Test Reactor

    Energy Technology Data Exchange (ETDEWEB)

    S. B. Grover

    2007-05-01

    The United States Department of Energy’s Advanced Gas Reactor (AGR) Fuel Development and Qualification Program will be irradiating eight separate low enriched uranium (LEU) oxycarbide (UCO) tri-isotropic (TRISO) particle fuel (in compact form) experiments in the Advanced Test Reactor (ATR) located at the Idaho National Laboratory (INL). The ATR has a long history of irradiation testing in support of reactor development and the INL has been designated as the new United States Department of Energy’s lead laboratory for nuclear energy development. The ATR is one of the world’s premiere test reactors for performing long term, high flux, and/or large volume irradiation test programs. These irradiations and fuel development are being accomplished to support development of the next generation reactors in the United States. The AGR fuel experiments will be irradiated over the next ten years to demonstrate and qualify new particle fuel for use in high temperature gas reactors. The goals of the irradiation experiments are to provide irradiation performance data to support fuel process development, to qualify fuel for normal operating conditions, to support development and validation of fuel performance and fission product transport models and codes, and to provide irradiated fuel and materials for post irradiation examination (PIE) and safety testing.1,2 The experiments, which will each consist of six separate capsules, will be irradiated in an inert sweep gas atmosphere with individual on-line temperature monitoring and control of each capsule. The sweep gas will also have on-line fission product monitoring on its effluent to track performance of the fuel in each individual capsule during irradiation. The final design phase for the first experiment was completed in 2005, and the fabrication and assembly of the first experiment test train (designated AGR-1) as well as the support systems and fission product monitoring system that will monitor and control the experiment

  18. The siting of UK nuclear reactors

    International Nuclear Information System (INIS)

    Choosing a suitable site for a nuclear power station requires the consideration and balancing of several factors. Some ‘physical’ site characteristics, such as the local climate and the potential for seismic activity, will be generic to all reactors designs, while others, such as the availability of cooling water, the area of land required and geological conditions capable of sustaining the weight of the reactor and other buildings will to an extent be dependent on the particular design of reactor chosen (or alternatively the reactor design chosen may to an extent be dependent on the characteristics of an available site). However, one particularly interesting tension is a human and demographic one. On the one hand it is beneficial to place nuclear stations close to centres of population, to reduce transmission losses and other costs (including to the local environment) of transporting electricity over large distances from generator to consumer. On the other it is advantageous to place nuclear stations some distance away from such population centres in order to minimise the potential human consequences of a major release of radioactive materials in the (extremely unlikely) event of a major nuclear accident, not only in terms of direct exposure but also concerning the management of emergency planning, notably evacuation. This paper considers the emergence of policies aimed at managing this tension in the UK. In the first phase of nuclear development (roughly speaking 1945–1965) there was a highly cautious attitude, with installations being placed in remote rural locations with very low population density. The second phase (1965–1985) saw a more relaxed approach, allowing the development of AGR nuclear power stations (which with concrete pressure vessels were regarded as significantly safer) closer to population centres (in ‘semi-urban’ locations, notably at Hartlepool and Heysham). In the third phase (1985–2005) there was very little new nuclear

  19. The siting of UK nuclear reactors.

    Science.gov (United States)

    Grimston, Malcolm; Nuttall, William J; Vaughan, Geoff

    2014-06-01

    Choosing a suitable site for a nuclear power station requires the consideration and balancing of several factors. Some 'physical' site characteristics, such as the local climate and the potential for seismic activity, will be generic to all reactors designs, while others, such as the availability of cooling water, the area of land required and geological conditions capable of sustaining the weight of the reactor and other buildings will to an extent be dependent on the particular design of reactor chosen (or alternatively the reactor design chosen may to an extent be dependent on the characteristics of an available site). However, one particularly interesting tension is a human and demographic one. On the one hand it is beneficial to place nuclear stations close to centres of population, to reduce transmission losses and other costs (including to the local environment) of transporting electricity over large distances from generator to consumer. On the other it is advantageous to place nuclear stations some distance away from such population centres in order to minimise the potential human consequences of a major release of radioactive materials in the (extremely unlikely) event of a major nuclear accident, not only in terms of direct exposure but also concerning the management of emergency planning, notably evacuation.This paper considers the emergence of policies aimed at managing this tension in the UK. In the first phase of nuclear development (roughly speaking 1945-1965) there was a highly cautious attitude, with installations being placed in remote rural locations with very low population density. The second phase (1965-1985) saw a more relaxed approach, allowing the development of AGR nuclear power stations (which with concrete pressure vessels were regarded as significantly safer) closer to population centres (in 'semi-urban' locations, notably at Hartlepool and Heysham). In the third phase (1985-2005) there was very little new nuclear development, Sizewell

  20. Reactor container

    International Nuclear Information System (INIS)

    Purpose: To prevent shocks exerted on a vent head due to pool-swell caused within a pressure suppression chamber (disposed in a torus configuration around the dry well) upon loss of coolant accident in BWR type reactors. Constitution: The following relationship is established between the volume V (m3) of a dry well and the ruptured opening area A (m2) at the boundary expected upon loss of coolant accident: V >= 30340 (m) x A Then, the volume of the dry well is made larger than the ruptured open area, that is, the steam flow rate of leaking coolants upon loss of coolant accident to decrease the pressure rise in the dry well at the initial state where loss of coolant accident is resulted. Accordingly, the pressure of non-compressive gases jetted out from the lower end of the downcomer to the pool water is decreased to suppress the pool-swell. (Ikeda, J.)

  1. A History of Dosimetry for the Advanced Gas-cooled Reactors

    Directory of Open Access Journals (Sweden)

    Shaw Simon

    2016-01-01

    Full Text Available This paper presents a summary of the methods used in the first ∼40 years of AGR neutron dosimetry and nuclear heating calculations, and the influence of the earlier Magnox reactor dosimetry programme. While the current state-of-the-art Monte Carlo methods are extremely powerful they still require very careful consideration of the quality of the input data, nuclear data validation and variance reduction techniques; in particular, this paper examines the difficulties in assuring the adequate convergence of calculations when Monte Carlo acceleration is applied in the presence of significant streaming paths through attenuating or scattering media.

  2. A History of Dosimetry for the Advanced Gas-cooled Reactors

    Science.gov (United States)

    Shaw, Simon; Thornton, Dean

    2016-02-01

    This paper presents a summary of the methods used in the first ˜40 years of AGR neutron dosimetry and nuclear heating calculations, and the influence of the earlier Magnox reactor dosimetry programme. While the current state-of-the-art Monte Carlo methods are extremely powerful they still require very careful consideration of the quality of the input data, nuclear data validation and variance reduction techniques; in particular, this paper examines the difficulties in assuring the adequate convergence of calculations when Monte Carlo acceleration is applied in the presence of significant streaming paths through attenuating or scattering media.

  3. Valoración físico-química y fitotóxica de las aguas residuales depuradas/regeneradas destinadas al riego agrícola

    Directory of Open Access Journals (Sweden)

    J.A. Pérez Donato

    2015-01-01

    Full Text Available La aplicación más extendida de la reutilización de aguas residuales domésticas depuradas/regeneradas es el riego agrícol a. Las normativas comunes sobre calidad de aguas regeneradas para reutilización contemplan paráme tros físico-químicos y biológico s para minimizar riesgos sanitarios, pero pocas veces tienen en c uenta parámetros fitotóxicos que puede n ser limitantes para aplicacio nes agrícolas. Los parámetros físico-químicos y fitotóxicos cambian al avanzar en el grado de depuración/regeneración de las aguas residuales, por lo que resulta d e interés conocer que etapa de la instalación proporciona el agua a decuada para el riego. Este tr abajo presenta un estudio de correlaci ón de fitotoxicidad con parámet ros físico-químicos en agua de muestras tomadas al final de cada un a de las etapas de tratamiento conve ncional de aguas residuales domésticas, que incluye reactor b iológico de lodos activados y tratamiento terciario con filtración de arena, cloración, filtr ación en cartucho y desalinización por electrodiálisis reversible.En cad a muestra se midió: demanda química de oxígeno, pH, conductividad , carbono orgánico, fósforo total, proteínas solubles, y los ione s de Na, K, Ca, Mg, B, F y Cl. Los criter ios de fitotoxicidad se evaluar on mediante el biomarcador Lactuca sativa. Los resultados mostraron reducciones importantes de los pa rámetros físico-químicos en el proceso de electrodiálisis, mien tras que los efectos de fitotox icidad mostraron reducciones en los pro cesos anteriores a la etapa fin al de electrodiálisis. Se concluye que l os parámetros físico-químicos , conjuntamente con el marcador biológico, constituyen aspectos d e interés práctico que relaciona e l tipo de tratamiento con la ca lidad físico-química y la fitotoxicida d del agua depurada/regenerada obtenida y su idoneidad para aplicaciones de riego agrícola.

  4. A competitividade do regadio em Portugal no contexto da Nova Política Agrícola Comum: o caso de uma exploração agrícola no Alentejo

    Directory of Open Access Journals (Sweden)

    Rui Manuel Sousa Fragoso

    2007-03-01

    Full Text Available A Nova Reforma da Política Agrícola Comum (PAC aprovada em 2003 constitui um reforço dos principais objectivos das reformas anteriores de 1992 e de 2000, como a promoção da competitividade do sector agrícola, da multifuncionalidade dos espaços rurais e agrícolas e da exploração sustentável dos recursos. No essencial, substituem-se as ajudas diretas à produção previstas na maioria dos regulamentos das Organizações Comuns de Mercado, por um regime de pagamento único por exploração sujeito a normas de eco-condicionalidade e a limitações na reconversão dos sistemas de produção agrícola. Este artigo avalia os impactos da nova PAC na competitividade do regadio em Portugal nas explorações agrícolas do Alentejo, nomeadamente, dos efeitos do pagamento único na afetação e na retribuição dos recursos agrícolas, de modo a identificar as principais alterações nas orientações produtivas e nos rendimentos agrícolas. Também são avaliados alguns dos principais impactos sócio-econômicos e ambientais diretos decorrentes dos ajustamentos produzidos com a Nova PAC. A metodologia utilizada baseia-se no desenvolvimento de um modelo micro-econômico de programação matemática estocástica discreta de maximização do valor esperado e de minimização do risco, adaptado às características de uma empresa agrícola do Alentejo. O modelo é utilizado para avaliar prospectivamente o plano de produção e o rendimento no curto e no longo prazo, mediante os cenários da reforma da PAC de 2000 e da Nova Reforma da PAC de 2003.The 2003 Common Agricultural Policy (CAP reform constitutes a reinforcement of the main objectives of the previous reforms of 1992 and of 2000, namely the promotion of the agricultural competitiveness, the multiple functions of the rural and agricultural areas and the sustainable resource exploitation. The direct production aids in the most Common Market Organizations are replaced by an only payment for each

  5. Programa doctorado en mecanización agrícola un nuevo paso en el desarrollo científico de la ingeniería agrícola

    OpenAIRE

    Ciro E. Iglesias Coronel

    2006-01-01

    En el presente trabajo se brinda una panorámica del Programa Doctoral en Mecanización Agrícola, el cual se encuentra en estado de desarrollo en la actualidad, con el objetivo de darlo a conocer y recoger sugerencias para su mejora antes de su presentación a la Comisión Nacional de Grado Científico

  6. Analysis of the horizontal flow in the advanced gas-cooled reactor

    Energy Technology Data Exchange (ETDEWEB)

    Duan, Y. [Department of Mechanical Engineering, University of Sheffield, Sheffield S1 3JD (United Kingdom); He, S., E-mail: s.he@sheffield.ac.uk [Department of Mechanical Engineering, University of Sheffield, Sheffield S1 3JD (United Kingdom); Ganesan, P. [Department of Mechanical Engineering, University of Malaya, Kuala Lumpur 50603 (Malaysia); Gotts, J. [EDF Energy, Barnwood, Gloucester GL4 3RS (United Kingdom)

    2014-06-01

    Highlights: • CFD is used to assess the effect of horizontal flows in AGRs. • The horizontal flows can reduce the graphite brick temperature significantly. • Such effects are not taken into consideration in current engineering calculations. • There might be flow instabilities when the fuel channel flow is very low but horizontal flows reduce its possibility. - Abstract: The purpose of the paper is to report a computational investigation of horizontal flows in the UK advanced-gas-cooled reactor (AGR) by using computational fluid dynamics with ANSYS FLUENT. The study is relevant to practical issues encountered in some AGR stations currently in operation in the UK. It is carried out using a comparative approach based on the results of two contrasting models: one simulating the full effect of the cross flow, the other simulating the simplified approach currently employed by the industry which neglects the momentum of the horizontal cross flow. The study reveals that the horizontal cross flow plays a significant role in the cooling of the moderator brick, while the axial variation of the brick geometry also significantly changes the distribution of the temperature within the brick. It is also found that under some circumstances the so-called horizontal inter-brick leakage (HIBL) flow could influence the cooling performance in the narrow gaps, resulting in a local hot spot. Furthermore, there may be flow instabilities in the flows in AGR fuel channels due to the interactions between the flow in the main arrowhead flow passages and that in some narrow passages connected to it, but the influence on the brick temperature is negligible. Horizontal cross flow has an effect of reducing such instabilities.

  7. A "reforma agrária assistida pelo mercado" do Banco Mundial na Colômbia e no Brasil (1994-2002

    Directory of Open Access Journals (Sweden)

    João Márcio Mendes Pereira

    2015-01-01

    Full Text Available RESUMOO artigo analisa a implantação da "reforma agrária assistida pelo mercado" (RAAM do Banco Mundial na Colômbia e no Brasil. Mostra que a RAAM foi concebida e implementada como um modelo contrário às reformas agrárias redistributivas, baseadas na desapropriação de terras pelo Estado. Também analisa os resultados da RAAM nos dois países, argumentando que a sua função principal não foi econômica, mas sim política, ao ajustar a política agrária à agenda neoliberal e servir como instrumento para esvaziar a luta popular pela democratização da estrutura agrária em sociedades altamente desiguais.

  8. AGR-1 Compact 4-1-1 Post-Irradiation Examination Results

    Energy Technology Data Exchange (ETDEWEB)

    Demkowicz, Paul Andrew [Idaho National Lab. (INL), Idaho Falls, ID (United States); Harp, Jason M. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Winston, Philip L. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Ploger, Scott A. [Idaho National Lab. (INL), Idaho Falls, ID (United States); van Rooyen, Isabella J. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-02-01

    Destructive post-irradiation examination was performed on AGR-1 fuel Compact 4 1 1, which was irradiated to a final compact-average burnup of 19.4% FIMA (fissions per initial metal atom) and a time-average, volume-average temperature of 1072°C. The analysis of this compact focused on characterizing the extent of fission product release from the particles and examining particles to determine the condition of the kernels and coating layers. The work included deconsolidation of the compact and leach-burn-leach analysis, visual inspection and gamma counting of individual particles, metallurgical preparation of selected particles, and examination of particle cross-sections with optical microscopy, electron microscopy, and elemental analysis. Deconsolidation-leach-burn-leach (DLBL) analysis revealed no particles with failed TRISO or failed SiC layers (as indicated by very low uranium inventory in all of the leach solutions). The total fractions of the predicted compact inventories of fission products Ce-144, Cs-134, Cs-137, and Sr-90 that were present in the compact outside of the SiC layers were <2×10 6, based on DLBL data. The Ag-110m fraction in the compact outside the SiC layers was 3.3×10 2, indicating appreciable release of silver through the intact coatings and subsequent retention in the OPyC layers or matrix. The Eu-154 fraction was 2.4×10 4, which is equivalent to the inventory in one average particle, and indicates a small but measurable level of release from the intact coatings. Gamma counting of 61 individual particles indicated no particles with anomalously low fission product retention. The average ratio of measured inventory to calculated inventory was close to a value of 1.0 for several fission product isotopes (Ce-144, Cs-134, and Cs-137), indicating good retention and reasonably good agreement with the predicted inventories. Measured-to-calculated (M/C) activity ratios for fission products Eu-154, Eu-155, Ru-106, Sb-125, and Zr-95 were

  9. Aspectos constitucionais do direito agrário emenda constitucional N° 10/64

    Directory of Open Access Journals (Sweden)

    José Carlos Vieira

    1988-07-01

    Full Text Available This paper, presents a brief history of the constitutional work applied to property rights in Brazil, mainly to those regarding land property. lt also shows the development of agrarian rights as an independent branch of the juridical prescription up to its effective recognition. It slightly shows the important role of the social function of property in constitutional texts as to support governmental actions aiming at an agrarian reform, and any other tendency to alter the rural profile of the country. This work is aimed to show that, despite a set of laws related to the agrarian reality of this country, the facts and data make it clear that nothing has been done about it up to today. The research Our constitutional texts shows that some advances towards the effectiveness of the social function of property principles have been made; nevertheless, the constitution to be promulgated by the year 1988, surprisingly takes a step backwards as to this chapter for it decreases the scope that it had in former constitutions and even in the original ones by authoritarian governments.O presente trabalho contém um resumo histórico do tratamento constitucional reservado ao direito de propriedade no Brasil, especialmente à propriedade da terra, bem assim a evolução do direito agrário como ramo autônomo do ordenamento jurídico, até o seu efetivo reconhecimento como tal. Registra, mesmo que rapidamente, a importância que teve a adotação do princípio da "função social da propriedade" nos textos constitucionais, de forma a respaldar ações governamentais objetivando a realização da reforma agrária e outras medidas tendentes a alterar o perfil rural do país. O trabalho procura mostrar, também, que, malgrado dispor o pais de um rol de leis capazes de dar suporte a propostas destinadas a promover uma efetiva mudança na realidade agrária, os fatos demonstram claramente que isto não ocorreu até hoje. A pesquisa nos textos constitucionais mostra

  10. The inhibition of Staphylococcus aureus agrC binding peptides on biofilm%金黄色葡萄球菌agrC结合小肽对生物膜的抑制作用

    Institute of Scientific and Technical Information of China (English)

    李学军; 杨和平; 戴晓天

    2010-01-01

    目的:体外观察金黄色葡萄球菌附属基因调节子(Accessory gene regulator,agr)agrC的特异结合小肽对葡萄球菌生物膜形成的影响.方法:人工合成agrC结合小肽(命名为N1),微量板半定量和激光共聚焦显微镜观察其对生物膜形成的影响;RT-PCR及Western blot观察其对自溶血素(Autolysin E, altE)和icaA蛋白的转录与表达水平的影响.结果:N1在金葡菌的粘附聚集期能显著抑制生物膜的形成,并影响生物膜形成相关因子的转录与表达.结论:N1可用于预防和治疗早期金葡菌生物膜相关感染.

  11. Comparative analysis of agr groups and virulence genes among subclinical and clinical mastitis Staphylococcus aureus isolates from sheep flocks of the Northeast of Brazil

    OpenAIRE

    de Almeida, Lara M.; de Almeida, Mayra Zilta P.R.B.; Carla L. Mendonça; Mamizuka, Elsa M.

    2013-01-01

    Staphylococcus aureus is one of the most frequent mastitis causative agents in small ruminants. The expression of most virulence genes of S. aureus is controlled by an accessory gene regulator (agr) locus. This study aimed to ascertain the prevalence of the different agr groups and to evaluate the occurrence of encoding genes for cytotoxin, adhesins and toxins with superantigen activity in S. aureus isolates from milk of ewes with clinical and subclinical mastitis in sheep flocks raised for m...

  12. La prensa agrícola del porfiriato como Fuente para la historia económica. (Ensayo de Fuentes

    Directory of Open Access Journals (Sweden)

    Ma. Cecilia Zuleta

    1999-01-01

    Full Text Available Al llegar al poder el presidente de MCxico Porfirio DSaz, la &te política del país consideró que el principal problema de MCxico era el atraso económico, por lo que era indispensable impulsar.el "desarrollo económico", cuya actividad primordial, era la agricultura comercial. Por tanto, comenzó a producirse entre los sectores intelectuales, políticos y de negocios una revalorización de la importancia de la actividad agrícola y con ello, el surgimiento de publicaciones especializadas en asuntos agrícolas que son, en la actualidad, una fuente importante para reconstruir la historia econ6- mica del periodo.

  13. “O Montado Multifuncional e a Integração na Politica Agrícola Comum”

    OpenAIRE

    Pinto-Correia, Teresa

    2011-01-01

    Resumo do Seminário “As diferentes funcionalidades dos montados nas políticas europeias - Caso da Política Agrícola Comum (PAC)” : Os montados são sistemas agro-silvo-pastoris equilibrados e sustentáveis, que favorecem a conservação dos recursos naturais. Estes sistemas desempenham importantes funções ecológicas, económicas e paisagísticas nas regiões em que estão inseridos, por permitirem conciliar a exploração agrícola, pecuária e cinegética com a preservação de um ecossistema de el...

  14. Agrégation d'informations et alternative au krigeage en environnement aléatoire

    OpenAIRE

    Ribereau, Pierre; Rullière, Didier

    2011-01-01

    Nous définissons une notion d'information d'une variable aléatoire, qui permet en particulier de modéliser les erreurs d'estimation. Nous bâtissons un opérateur d'agrégation d'informations, qui reste cohérent avec la réduction des erreurs d'estimation lors de la réitération d'observations d'une même variable aléatoire. Nous évoquons alors les problèmes liés à l'usage du krigeage en environnement bruité, et proposons l'usage de l'opérateur d'agrégation comme alternative à la construction de su...

  15. Prospectiva tecnológica y consideraciones curriculares en Ingeniería Agrícola

    Directory of Open Access Journals (Sweden)

    Jaime Salazar Contreras

    2011-01-01

    Full Text Available Los nuevos modelos económicos centrados en un mayor número de productos de exportación con un alto valor agregado hace necesario que se generen grandes desarrollos tecnológicos, en los cuales el papel de la Ingeniería es trascendental; para el caso de Ingeniería Agrícola se debe lograr importantes tecnificaciones del Sector Agropecuario para poder atender las demandas de productos alimenticios, para consumo interno y excedentes para otros países. Con el presente escrito se mostrará una visión prospectiva a nivel nacional e internacional de la Ingeniería Agrícola y fmalrnente algunas consideraciones sobre su currículo, con el propósito de reflexionar, cómo sería una formación competitiva, en los albores del siglo XXI.

  16. The sealing and testing of high integrity containers for the long term storage of AGR spent fuel

    International Nuclear Information System (INIS)

    The CEGB are designing and developing a dry storage facility for spent AGR fuel elements. The Store would be a large central facility capable of receiving fuel from any AGR Station or Sellafield and would act as a buffer in the overall spent fuel management strategy. The storage period could be long term, up to 100 years, and the store itself must be modular in construction to allow an indeterminate quantity of fuel to be stored economically and with minimum operating costs. Natural convection cooling is preferred to remove decay heat from the fuel and the technique involves sealing of fuel in containers which are placed in concrete vaults with a stack induced once-through cooling system. The remote sealing and testing of the containers prior to storage is the main topic dealt with below. (author)

  17. Emisiones de gases de efecto invernadero en sistemas agrícolas de México

    Directory of Open Access Journals (Sweden)

    Vinisa Saynes Santillán

    2016-03-01

    Full Text Available La agricultura es el sustento para la alimentación de una población mundial creciente. La agricultura es la cuarta causa de emisiones de GEI, y emite grandes cantidades de los llamados “gases que no son CO2” incluyendo al N2O y el CH4 con un poder de calentamiento 265 y 28 veces, respectivamente, mayor en comparación con el CO2. En México la información de las emisiones de GEI se reporta en diversos foros y desde diferentes perspectivas. En este trabajo se recopiló información de las emisiones de GEI de las Comunicaciones Nacionales y el Primer Informe Bienal, de publicaciones arbitradas por pares y de la literatura gris. Las emisiones del sector agrícola reportadas en las diferentes Comunicaciones presentan inconsistencias debido a factores como falta de información y de acceso a esta en las primeras dos Comunicaciones y a cuestiones de tipo metodológico en las Comunicaciones subsecuentes. De acuerdo con las estimaciones más actuales (Informe Bienal, las actividades agropecuarias son la tercera causa de generación de emisiones de GEI con una contribución del 12% a las emisiones nacionales. Dentro de esta categoría la mayor parte de las emisiones se generan por la fermentación entérica, el manejo del estiércol y por el uso de fertilizantes en los suelos agrícolas. Los principales retos para mejorar las estimaciones y reducir su incertidumbre es la generación de factores de emisión nacionales para lo cual es esencial contar con mayor información de las fuentes clave. En este trabajo se encontró que existe información relevante que sería de utilidad pero se encuentra dispersa por lo que falta síntesis y organización de la información sobre todo de la que se encuentra en la literatura gris.

  18. AGR-1 Fuel Compact 6-3-2 Post-Irradiation Examination Results

    Energy Technology Data Exchange (ETDEWEB)

    Paul demkowicz; jason Harp; Scott Ploger

    2012-12-01

    Destructive post-irradiation examination was performed on fuel Compact 6-3-2, which was irradiated in the AGR-1 experiment to a final compact average burnup of 11.3% FIMA and a time-average, volume-average temperature of 1070°C. The analysis of this compact was focused on characterizing the extent of fission product release from the particles and examining particles to determine the condition of the kernels and coating layers. The work included deconsolidation of the compact and leach-burn-leach analysis, visual inspection and gamma counting of individual particles, measurement of fuel burnup by several methods, metallurgical preparation of selected particles, and examination of particle cross-sections with optical microscopy. A single particle with a defective SiC layer was identified during deconsolidation-leach-burn-leach analysis, which is in agreement with previous measurements showing elevated cesium in the Capsule 6 graphite fuel holder associated with this fuel compact. The fraction of the compact europium inventory released from the particles and retained in the matrix was relatively high (approximately 6E-3), indicating release from intact particle coatings. The Ag-110m inventory in individual particles exhibited a very broad distribution, with some particles retaining =80% of the predicted inventory and others retaining less than 25%. The average degree of Ag-110m retention in 60 gamma counted particles was approximately 50%. This elevated silver release is in agreement with analysis of silver on the Capsule 6 components, which indicated an average release of 38% of the Capsule 6 inventory from the fuel compacts. In spite of the relatively high degree of silver release from the particles, virtually none of the Ag-110m released was found in the compact matrix, and presumably migrated out of the compact and was deposited on the irradiation capsule components. Release of all other fission products from the particles appears to be less than a single

  19. Ensino agrícola e influência norte-americana no Brasil (1945-1961

    Directory of Open Access Journals (Sweden)

    Sonia Regina de Mendonça

    2010-12-01

    Full Text Available O artigo trata das redefinições sofridas pelo Ensino Agrícola no Brasil, a partir da conjuntura marcada pelo fim da II Guerra Mundial/Guerra Fria, quando inúmeros acordos de "cooperação técnica" seriam firmados entre os governos brasileiro e estadunidense, objetivando "recuperar" seu novo público-alvo: o trabalhador rural adulto e analfabeto.

  20. La Mola d'Agres (Alacant): aproximació a la indústria lítica

    OpenAIRE

    Pardo Gordó, Salvador; Peña Sánchez, José Luis; Grau Almero, Elena

    2009-01-01

    Desde su descubrimiento, las excavaciones sistemáticas han colocado la Mola d"Agres (Alicante) como yacimiento referencia en el estudio de la Edad del Bronce en tierras valencianas. La finalidad del presente trabajo es realizar una aproximación a la industria lítica tallada a partir de los materiales recuperados en las últimas campañas (2000-2007), así como valorar este conjunto dentro del contexto de la Edad del Bronce.

  1. La industria de maquinaria agrícola en Argentina frente a la estructura sectorial del mercado internacional

    Directory of Open Access Journals (Sweden)

    Federico Langard

    2011-01-01

    Full Text Available En el marco de una continua reestructuración de las empresas trasnacionales productoras de maquinaria agrícola a nivel mundial, se observa una, significativa tendencia a la concentración de las mismas y a la oligopolización de la oferta mundial, situación que sin lugar a dudas impacta en nuestro país. El trabajo analiza la dinámica del comercio mundial de maquinaria agrícola, vinculada al desempeño del sector en Argentina. Para ello, se examina el comportamiento de las firmas nacionales y extranjeras [radicadas y no radicadas en el país] a partir de su inserción internacional. Para mejorar el nivel de las observaciones, el amplio espectro del sector de maquinaria agrícola es dividido en diferentes subsectores según producto. Este diseño de investigación pone en evidencia las estrategias seguidas por el entramado de empresas locales y multinacionales, en el territorio local y regional, y se observan, de acuerdo a ello, variadas ventajas en los diferentes subsectores

  2. Influence of Sae-regulated and Agr-regulated factors on the escape of Staphylococcus aureus from human macrophages.

    Science.gov (United States)

    Münzenmayer, Lisa; Geiger, Tobias; Daiber, Ellen; Schulte, Berit; Autenrieth, Stella E; Fraunholz, Martin; Wolz, Christiane

    2016-08-01

    Although Staphylococcus aureus is not a classical intracellular pathogen, it can survive within phagocytes and many other cell types. However, the pathogen is also able to escape from cells by mechanisms that are only partially understood. We analysed a series of isogenic S. aureus mutants of the USA300 derivative JE2 for their capacity to destroy human macrophages from within. Intracellular S. aureus JE2 caused severe cell damage in human macrophages and could efficiently escape from within the cells. To obtain this full escape phenotype including an intermittent residency in the cytoplasm, the combined action of the regulatory systems Sae and Agr is required. Mutants in Sae or mutants deficient in the Sae target genes lukAB and pvl remained in high numbers within the macrophages causing reduced cell damage. Mutants in the regulatory system Agr or in the Agr target gene psmα were largely similar to wild-type bacteria concerning cell damage and escape efficiency. However, these strains were rarely detectable in the cytoplasm, emphasizing the role of phenol-soluble modulins (PSMs) for phagosomal escape. Thus, Sae-regulated toxins largely determine damage and escape from within macrophages, whereas PSMs are mainly responsible for the escape from the phagosome into the cytoplasm. Damage of macrophages induced by intracellular bacteria was linked neither to activation of apoptosis-related caspase 3, 7 or 8 nor to NLRP3-dependent inflammasome activation.

  3. Analysis of Gln223Agr polymorphism of Leptin Receptor Gene in type II diabetic mellitus subjects among Malaysians.

    Science.gov (United States)

    Etemad, Ali; Ramachandran, Vasudevan; Pishva, Seyyed Reza; Heidari, Farzad; Aziz, Ahmad Fazli Abdul; Yusof, Ahmad Khairuddin Mohamed; Pei, Chong Pei; Ismail, Patimah

    2013-01-01

    Leptin is known as the adipose peptide hormone. It plays an important role in the regulation of body fat and inhibits food intake by its action. Moreover, it is believed that leptin level deductions might be the cause of obesity and may play an important role in the development of Type 2 Diabetes Mellitus (T2DM), as well as in cardiovascular diseases (CVD). The Leptin Receptor (LEPR) gene and its polymorphisms have not been extensively studied in relation to the T2DM and its complications in various populations. In this study, we have determined the association of Gln223Agr loci of LEPR gene in three ethnic groups of Malaysia, namely: Malays, Chinese and Indians. A total of 284 T2DM subjects and 281 healthy individuals were recruited based on International Diabetes Federation (IDF) criteria. Genomic DNA was extracted from the buccal specimens of the subjects. The commercial polymerase chain reaction (PCR) method was carried out by proper restriction enzyme MSP I to both amplify and digest the Gln223Agr polymorphism. The p-value among the three studied races was 0.057, 0.011 and 0.095, respectively. The values such as age, WHR, FPG, HbA1C, LDL, HDL, Chol and Family History were significantly different among the subjects with Gln223Agr polymorphism of LEPR (p < 0.05). PMID:24051404

  4. Analysis of Gln223Agr Polymorphism of Leptin Receptor Gene in Type II Diabetic Mellitus Subjects among Malaysians

    Directory of Open Access Journals (Sweden)

    Chong Pei Pei

    2013-09-01

    Full Text Available Leptin is known as the adipose peptide hormone. It plays an important role in the regulation of body fat and inhibits food intake by its action. Moreover, it is believed that leptin level deductions might be the cause of obesity and may play an important role in the development of Type 2 Diabetes Mellitus (T2DM, as well as in cardiovascular diseases (CVD. The Leptin Receptor (LEPR gene and its polymorphisms have not been extensively studied in relation to the T2DM and its complications in various populations. In this study, we have determined the association of Gln223Agr loci of LEPR gene in three ethnic groups of Malaysia, namely: Malays, Chinese and Indians. A total of 284 T2DM subjects and 281 healthy individuals were recruited based on International Diabetes Federation (IDF criteria. Genomic DNA was extracted from the buccal specimens of the subjects. The commercial polymerase chain reaction (PCR method was carried out by proper restriction enzyme MSP I to both amplify and digest the Gln223Agr polymorphism. The p-value among the three studied races was 0.057, 0.011 and 0.095, respectively. The values such as age, WHR, FPG, HbA1C, LDL, HDL, Chol and Family History were significantly different among the subjects with Gln223Agr polymorphism of LEPR (p < 0.05.

  5. Use of an Immobilized Monoclonal Antibody to Examine Integrin &agr;5&bgr;1 Signaling Independent of Cell Spreading

    Directory of Open Access Journals (Sweden)

    Bao Wenjie

    2002-01-01

    Full Text Available Cell attachment to the extracellular matrix (ECM engages integrin signaling into the cell, but part of the signaling response also stem from cell spreading (3. To analyze specific integrin signaling-mediated responses independent of cell spreading, we developed a method engaging integrin signaling by use of an immobilized anti-integrin monoclonal antibody (mab directed against the fibronectin (FN receptor integrin &agr;5&bgr;1. ECV 304 cells were plated onto FN or immobilized mab JBS5 (anti-integrin &agr;5&bgr;1 or onto poly-L-lysin (P-L-L, which mediates integrin-independent attachment. Cells attached and spread on FN, while cells on JBS5 or P-L-L attached but did not spread. Importantly, plating onto FN or mab JBS5 gave rise to identical integrin-induced responses, including a down-regulation of the cyclin-dependent kinase (Cdk2 inhibitors p21CIP1 and p27KIP1, while attachment to P-L-L did not. We conclude that engagement of the FN-receptor integrin &agr;5&bgr;1 induces integrin signaling regulating the Cdk2-inhibitors independent of cell spreading and present a method for how integrin signaling can be analyzed separate from the effects of cell spreading.

  6. Lucienville's Agriculture Corp. Ltda. Cooperativa Agrícola Lucienville Ltda.

    Directory of Open Access Journals (Sweden)

    Patricia Boari

    2008-01-01

    Full Text Available Since the evolution of agriculture corporativism and through its memoirs and balance books the present study analyzes the development of Lucienville's Agriculture Corp. Ltda. during the historic peronism. On this stage the institution got a particular incidence on diverse economic activities of national agro (seed accumulation, its industrialization and commercialization, at the same time it strengthened its role as center of social services to the associates.A partir de la evolución del cooperativismo agrario argentino y a través de sus memorias y balances el presente estudio analiza el desenvolvimiento de la Cooperativa Agrícola Lucienville Ltda. durante el peronismo histórico. En esta etapa la institución adquiere particular incidencia en las diversas actividades económicas del agro regional (acopio de semillas, su industrialización y comercialización, al tiempo que refuerza su rol como centro de servicios sociales para los asociados.

  7. Preliminary results of post-irradiation examination of the AGR-1 TRISO fuel compacts

    Energy Technology Data Exchange (ETDEWEB)

    Paul Demkowicz; John Hunn; Robert Morris; Jason Harp; Philip Winston; Charles Baldwin; Fred Montgomery; Scott Ploger; Isabella van Rooyen

    2012-10-01

    Five irradiated fuel compacts from the AGR-1 experiment have been examined in detail in order to assess in-pile fission product release behavior. Compacts were electrolytically deconsolidated and analyzed using the leach-burn-leach technique to measure fission product inventory in the compact matrix and identify any particles with a defective SiC layer. Loose particles were then gamma counted to measure the fission product inventory. One particle with a defective SiC layer was found in the five compacts examined. The fractional release of Ag 110m from the particles was significant. The total fraction of silver released from all the particles within a compact ranged from 0-0.63 and individual particles within a single compact often exhibited a very wide range of silver release. The average fractional release of Eu-154 from all particles in a compact was 2.4×10-4—1.3×10-2, which is indicative of release through intact coatings. The fractional Cs-134 inventory in the compact matrix was <2×10-5 when all coatings remained intact, indicating good cesium retention. Approximately 1% of the palladium inventory was found in the compact matrix for two of the compacts, indicating significant release through intact coatings.

  8. Research Nuclear Reactors

    International Nuclear Information System (INIS)

    Published in English and in French, this large report first proposes an overview of the use and history of research nuclear reactors. It discusses their definition, and presents the various types of research reactors which can be either related to nuclear power (critical mock-ups, material test reactors, safety test reactors, training reactors, prototypes), or to research (basic research, industry, health), or to specific particle physics phenomena (neutron diffraction, isotope production, neutron activation, neutron radiography, semiconductor doping). It reports the history of the French research reactors by distinguishing the first atomic pile (ZOE), and the activities and achievements during the fifties, the sixties and the seventies. It also addresses the development of instrumentation for research reactors (neutron, thermal, mechanical and fission gas release measurements). The other parts of the report concern the validation of neutronics calculations for different reactors (the EOLE water critical mock-up, the MASURCA air critical mock-up dedicated to fast neutron reactor study, the MINERVE water critical mock-up, the CALIBAN pulsed research reactor), the testing of materials under irradiation (OSIRIS reactor, laboratories associated with research reactors, the Jules Horowitz reactor and its experimental programs and related devices, irradiation of materials with ion beams), the investigation of accident situations (on the CABRI, Phebus, Silene and Jules Horowitz reactors). The last part proposes a worldwide overview of research reactors

  9. The Next Generation Nuclear Plant/Advanced Gas Reactor Fuel Irradiation Experiments in the Advanced Test Reactor

    Energy Technology Data Exchange (ETDEWEB)

    S. Blaine Grover

    2009-09-01

    The United States Department of Energy’s Next Generation Nuclear Plant (NGNP) Program will be irradiating eight separate low enriched uranium (LEU) tri-isotopic (TRISO) particle fuel (in compact form) experiments in the Advanced Test Reactor (ATR) located at the Idaho National Laboratory (INL). The ATR has a long history of irradiation testing in support of reactor development and the INL has been designated as the new United States Department of Energy’s lead laboratory for nuclear energy development. The ATR is one of the world’s premiere test reactors for performing long term, high flux, and/or large volume irradiation test programs. These irradiations and fuel development are being accomplished to support development of the next generation reactors in the United States, and will be irradiated over the next ten years to demonstrate and qualify new particle fuel for use in high temperature gas reactors. The goals of the irradiation experiments are to provide irradiation performance data to support fuel process development, to qualify fuel for normal operating conditions, to support development and validation of fuel performance and fission product transport models and codes, and to provide irradiated fuel and materials for post irradiation examination (PIE) and safety testing. The experiments, which will each consist of at least six separate capsules, will be irradiated in an inert sweep gas atmosphere with individual on-line temperature monitoring and control of each capsule. The sweep gas will also have on-line fission product monitoring on its effluent to track performance of the fuel in each individual capsule during irradiation. The first experiment (designated AGR-1) started irradiation in December 2006, and the second experiment (AGR-2) is currently in the design phase. The design of test trains, as well as the support systems and fission product monitoring system that will monitor and control the experiment during irradiation will be discussed. In

  10. Reactor Physics Training

    International Nuclear Information System (INIS)

    University courses in nuclear reactor physics at the universities consist of a theoretical description of the physics and technology of nuclear reactors. In order to demonstrate the basic concepts in reactor physics, training exercises in nuclear reactor installations are also desirable. Since the number of reactor facilities is however strongly decreasing in Europe, it becomes difficult to offer to students a means for demonstrating the basic concepts in reactor physics by performing training exercises in nuclear installations. Universities do not generally possess the capabilities for performing training exercises. Therefore, SCK-CEN offers universities the possibility to perform (on a commercial basis) training exercises at its infrastructure consisting of two research reactors (BR1 and VENUS). Besides the organisation of training exercises in the framework of university courses, SCK-CEN also organizes theoretical courses in reactor physics for the education and training of nuclear reactor operators. It is indeed a very important subject to guarantee the safe operation of present and future nuclear reactors. In this framework, an understanding of the fundamental principles of nuclear reactor physics is also necessary for reactor operators. Therefore, the organisation of a basic Nuclear reactor physics course at the level of reactor operators in the initial and continuous training of reactor operators has proven to be indispensable. In most countries, such training also results from the direct request from the safety authorities to assure the high level of competence of the staff in nuclear reactors. The objectives this activity are: (1) to provide training and education activities in reactor physics for university students and (2) to organise courses in nuclear reactor physics for reactor operators

  11. Safeguarding research reactors

    International Nuclear Information System (INIS)

    The report is organized in four sections, including the introduction. The second section contains a discussion of the characteristics and attributes of research reactors important to safeguards. In this section, research reactors are described according to their power level, if greater than 25 thermal megawatts, or according to each fuel type. This descriptive discussion includes both reactor and reactor fuel information of a generic nature, according to the following categories. 1. Research reactors with more than 25 megawatts thermal power, 2. Plate fuelled reactors, 3. Assembly fuelled reactors. 4. Research reactors fuelled with individual rods. 5. Disk fuelled reactors, and 6. Research reactors fuelled with aqueous homogeneous fuel. The third section consists of a brief discussion of general IAEA safeguards as they apply to research reactors. This section is based on IAEA safeguards implementation documents and technical reports that are used to establish Agency-State agreements and facility attachments. The fourth and last section describes inspection activities at research reactors necessary to meet Agency objectives. The scope of the activities extends to both pre and post inspection as well as the on-site inspection and includes the examination of records and reports relative to reactor operation and to receipts, shipments and certain internal transfers, periodic verification of fresh fuel, spent fuel and core fuel, activities related to containment and surveillance, and other selected activities, depending on the reactor

  12. OECD NEA Benchmark Database of Spent Nuclear Fuel Isotopic Compositions for World Reactor Designs

    Energy Technology Data Exchange (ETDEWEB)

    Gauld, Ian C [ORNL; Sly, Nicholas C [ORNL; Michel-Sendis, Franco [OECD Nuclear Energy Agency

    2014-01-01

    Experimental data on the isotopic concentrations in irradiated nuclear fuel represent one of the primary methods for validating computational methods and nuclear data used for reactor and spent fuel depletion simulations that support nuclear fuel cycle safety and safeguards programs. Measurement data have previously not been available to users in a centralized or searchable format, and the majority of accessible information has been, for the most part, limited to light-water-reactor designs. This paper describes a recent initiative to compile spent fuel benchmark data for additional reactor designs used throughout the world that can be used to validate computer model simulations that support nuclear energy and nuclear safeguards missions. Experimental benchmark data have been expanded to include VVER-440, VVER-1000, RBMK, graphite moderated MAGNOX, gas cooled AGR, and several heavy-water moderated CANDU reactor designs. Additional experimental data for pressurized light water and boiling water reactor fuels has also been compiled for modern assembly designs and more extensive isotopic measurements. These data are being compiled and uploaded to a recently revised structured and searchable database, SFCOMPO, to provide the nuclear analysis community with a centrally-accessible resource of spent fuel compositions that can be used to benchmark computer codes, models, and nuclear data. The current version of SFCOMPO contains data for eight reactor designs, 20 fuel assembly designs, more than 550 spent fuel samples, and measured isotopic data for about 80 nuclides.

  13. Estudio de los métodos para la evaluación de los proveedores para una empresa de fabricación de maquinaria agrícola

    OpenAIRE

    Vilalta Martí, Josep M.

    2012-01-01

    El objeto de este proyecto es el estudio de los métodos para la evaluación de los proveedores para una empresa de fabricación de maquinaria agrícola y la implantación de la misma. Concretamente maquinaria agrícola pesada destinada al transporte de productos agrícolas. Dicha fábrica estará situada en la provincia de Lérida.

  14. The breeder reactor in electricity supply

    International Nuclear Information System (INIS)

    Forecasts are made of Britain's energy prospects in the year 2000. It is concluded that fossil fuels and renewable energy sources will leave an energy gap and that dependence on nuclear power will be substantial. There will, however have been a rapid depletion of readily available uranium ore reserves and a growing availability of plutonium from thermal reactors. Britain's resources of plutonium and depleted uranium which the fast breeder reactor can use - will equal many thousand million tonnes of coal. Our nuclear programme should therefore include one or two FBRs. Resources should be pooled internationally and plants built to prove alternative options and consolidate an already highly developed technology. In Britain our earliest nuclear (Magnox) stations have served as well. In Scotland, where next year an estimated 30% of electricity output will be nuclear, Hunterston 'B' AGR has had a splendid first year of operation, and pumped storage capacity in Scotland has extended the benefits of low-cost generation. The FBR has many very satisfactory engineering features and is eminently controllable and well behaved. It is compact, with relatively low cooling-water requirements and it could be built, one hopes, close to our load centres. There can be confidence that it will be proved safe. An order for an FBR, on the earliest timescale that fits in with evidence of successful operation of the Dounreay PFR and an agreed international programme, would serve the national interest and ensure the survival of our plant manufacturers, so badly hit by the effects of stagnation of the U.K. economy. (author)

  15. Mudanças na pauta das exportações agrícolas brasileiras

    Directory of Open Access Journals (Sweden)

    Maria Auxiliadora de Carvalho

    2008-03-01

    Full Text Available O trabalho visa contribuir para o debate sobre desindustrialização no Brasil, atribuída à apreciação cambial que, para vários autores, decorre do aumento das exportações agrícolas. Do emprego do método constant market share sobre informações de comércio exterior da FAO, para o período 1991-2003, chegou-se à conclusão que a exportação agrícola brasileira cresceu mais que o potencial, resultado de aumento expressivo da competitividade. Depois da mudança cambial, em 1999, parte da competitividade foi neutralizada pelo aumento da participação na pauta de produtos com demanda mundial em declínio. Da decomposição do valor exportado prevaleceu o efeito do aumento da quantidade, fato mais evidente depois da mudança cambial, porque o efeito preço foi negativo. Mesmo descontando o efeito da depreciação real do câmbio, a mudança nos preços internacionais foi desfavorável à agricultura brasileira. O efeito flexibilidade da pauta, negativo em todo o período, indica grande participação de produtos em desacordo com a lei geral da oferta, fato mais grave no período recente, quando a maior parte dos produtos com aumento do volume exportado estava com preço em baixa no mercado internacional. O declínio da exportação de manufaturados e o maior crescimento do comércio de produtos básicos indicam tendência à desindustrialização da agricultura.This paper aims to contribute to the Brazilian deindustrialization debate, attributed to exchange appreciation that, for several authors, is the agricultural export increase effect. Constant market share method applied on FAO export data, for the 1991 to 2003 period, indicates that Brazilian agricultural export increased more than the potential rate, due to expressive competitiveness gains. After the exchange regime change, in 1999, the competitiveness increase was partly neutralized by growth share of products whose world demand was in decline. Exports value decomposition showed

  16. Estudio bibliométrico de la Revista Centro Agrícola, Cuba

    Directory of Open Access Journals (Sweden)

    Luis Ernesto Paz Enrique

    2016-07-01

    Full Text Available Los análisis de referencias de las publicaciones seriadas constituyen herramientas oportunas para la toma de decisiones encaminadas a mejorar la calidad de las revistas. En este artículo se plantean como objetivos examinar las referencias de los artículos publicados por la Revista Centro Agrícola de la Universidad Central ''Marta Abreu'' de Las Villas, Cuba; e identificar aspectos necesarios para favorecer la indización de la publicación en bases de datos de prestigio internacional. En el estudio se caracteriza la publicación y las referencias que emplea la revista. Se aplican cinco indicadores unidimensionales: año más referenciado, tipología documental más referenciada, autores más referenciados, índice Price por años e índice Price total; esto posibilita identificar las debilidades de la publicación. Para la obtención de los resultados se crea una base de datos bibliográfica, siendo este producto uno de los resultados de la investigación. Se analizan las oportunidades que ofrece el Open Journal Systems para las publicaciones seriadas, la necesidad de utilizar referencias actualizadas y los aspectos negativos de la endogamia editorial. El análisis arriba a conclusiones y recomendaciones que contribuirán a mejorar la calidad de la revista, facilitando el posicionamiento e indización en bases de datos de prestigio

  17. Examining the Quality of Life of Farmers with Disabilities: The Ohio AgrAbility Study.

    Science.gov (United States)

    Windon, S R; Jepsen, S D; Scheer, S D

    2016-01-01

    Quality of life is a broad concept that presents a challenge to measure as a scientific category. Quality of life encompasses a broad range of variables based on an individual's expression of life satisfaction, perceptions, values, feelings of subjective well-being, and happiness. This study identified and examined factors that influenced the quality of life of Ohio farmers with disabilities who were enrolled in the Ohio AgrAbility Program (OAP) (n = 55) and participated in this study (60% response rate). A 34-item questionnaire was created. The sample of OAP farmers reported stress many days a week, had a negative outlook on life, and were less satisfied with their overall quality of life because of their health. The OAP participants reported external factors, such as cost of equipment, financial pressures, and input costs, as having a negative effect on their quality of life. The participants also reported that they were not satisfied with the amount of vacation time (60.6%), managing farm work and family life (54.6%), overall health (55%), and quality of life (27%). The results showed a significant difference between the OAP participants' overall quality of life and the following variables: gender, net cash income, outlook on life, health, stress, farm work, managing farm and family, social activities, and emotional support for farmers with disabilities. The findings of this exploratory study allowed farmers to identify factors that they perceived as important to their quality of life. Moreover, the results may be helpful for stakeholders to better understand the needs of farmers with disabilities and provide appropriate educational and other services to enhance their quality of life. PMID:27024989

  18. Examining the Quality of Life of Farmers with Disabilities: The Ohio AgrAbility Study.

    Science.gov (United States)

    Windon, S R; Jepsen, S D; Scheer, S D

    2016-01-01

    Quality of life is a broad concept that presents a challenge to measure as a scientific category. Quality of life encompasses a broad range of variables based on an individual's expression of life satisfaction, perceptions, values, feelings of subjective well-being, and happiness. This study identified and examined factors that influenced the quality of life of Ohio farmers with disabilities who were enrolled in the Ohio AgrAbility Program (OAP) (n = 55) and participated in this study (60% response rate). A 34-item questionnaire was created. The sample of OAP farmers reported stress many days a week, had a negative outlook on life, and were less satisfied with their overall quality of life because of their health. The OAP participants reported external factors, such as cost of equipment, financial pressures, and input costs, as having a negative effect on their quality of life. The participants also reported that they were not satisfied with the amount of vacation time (60.6%), managing farm work and family life (54.6%), overall health (55%), and quality of life (27%). The results showed a significant difference between the OAP participants' overall quality of life and the following variables: gender, net cash income, outlook on life, health, stress, farm work, managing farm and family, social activities, and emotional support for farmers with disabilities. The findings of this exploratory study allowed farmers to identify factors that they perceived as important to their quality of life. Moreover, the results may be helpful for stakeholders to better understand the needs of farmers with disabilities and provide appropriate educational and other services to enhance their quality of life.

  19. Centro de investigaciones agrícolas en Saint-Aubin - Fribourg – Suiza

    Directory of Open Access Journals (Sweden)

    Zweifel, J.

    1974-03-01

    Full Text Available This Centre is made up of different installations, such as: management building, plant protection station, research centre, veterinary station, fodder centre and auxiliary exploitation, farm area, insulation station, entrance and dwellings, mill, slaughterhouse, etc. All the buildings, except the fodder tower, have only one floor —of differing heights— so that all communications are horizontal. The prefabricated reinforced concrete pillars rest on pile foundations and act as a support for the roof parts, which are U-shaped, and achieve cenital lighting and the due stability, as well as providing a characteristic physionomy and distinctive appearance of the whole.Este complejo está constituido por diversas instalaciones, tales como: edificio de administración, estación de protección de plantas, centro de investigación, estación veterinaria, centro de forrajes y explotación auxiliar, zona agrícola, estación de aislamiento, entrada y viviendas, molino, matadero, etcétera. Todos los edificios, salvo la torre de forraje, tienen una sola planta —de diferentes alturas—, a fin de que todas las comunicaciones sean horizontales. Los pilares prefabricados de hormigón armado se apoyan sobre cimentación de pilotes y sirven de soporte a las piezas de cubierta, en forma de U, que procuran iluminación cenital y la debida estabilidad, además de ofrecer una fisonomía característica y distintiva al conjunto.

  20. 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.

  1. A Review of the United Kingdom Fast Reactor Programme, March 1987

    International Nuclear Information System (INIS)

    Nuclear power produced about 20% of the electricity supply in the United Kingdom in 1986, mostly from gas-cooled reactors, i.e. the 10 AGRs currently in operation and the 26 older MAGNOX reactors. Plans to increase the nuclear component of generating capacity by building the first PWR in the UK, Sizewell 'B', were strongly endorsed in the report by Sir Frank Layfield published on 26 January 1987. This resulted from the Public Inquiry into building Sizewell 'B', which was held between 11 January 1983 and 7 March 1985, the longest Public Inquiry ever held in the UK. The government gave the go-ahead for the building of Sizewell 'B' on 12 March 1987

  2. Calibration of dimensional change in finite element models using AGR moderator brick measurements

    Energy Technology Data Exchange (ETDEWEB)

    McNally, K., E-mail: kevin.mcnally@hsl.gsi.gov.uk [Health and Safety Laboratory, Harpur Hill, Buxton, Derbyshire SK17 9JN (United Kingdom); Hall, G. [NGRG, School of MACE, University of Manchester, Manchester M13 9PL (United Kingdom); Tan, E. [Health and Safety Laboratory, Harpur Hill, Buxton, Derbyshire SK17 9JN (United Kingdom); Marsden, B.J. [NGRG, School of MACE, University of Manchester, Manchester M13 9PL (United Kingdom); Warren, N. [Health and Safety Laboratory, Harpur Hill, Buxton, Derbyshire SK17 9JN (United Kingdom)

    2014-08-01

    Physically based models, resolved using the finite element (FE) method, are often used to model changes in geometry and the associated stress fields of graphite moderator bricks within a reactor. These models require inputs that describe the loading conditions (field variables), and coded relationships describing the behaviour of material properties. Historically, behaviour on material properties have been obtained from Materials Test Reactor (MTR) experiments, however data relating to samples trepanned from operating reactors are increasingly being used to improve models. Geometry measurements from operating reactors offer the potential for improving the coded relationship for dimensional change in FE models. A non-linear mixed-effect model is presented for calibrating the parameters of FE models that are sensitive to mid-brick diameter, using channel geometry measurements obtained from inspection campaigns. The work makes use of a novel technique: the development of a Bayesian emulator, which is a surrogate for the FE model. The use of an emulator allows the influence of the inputs to the finite element model to be evaluated, and delivers a substantial reduction in the computational burden of calibration.

  3. Ship propulsion reactors technology

    International Nuclear Information System (INIS)

    This paper takes the state of the art on ship propulsion reactors technology. The french research programs with the corresponding technological stakes, the reactors specifications and advantages are detailed. (A.L.B.)

  4. Undergraduate reactor control experiment

    International Nuclear Information System (INIS)

    A sequence of reactor and related experiments has been a central element of a senior-level laboratory course at Pennsylvania State University (Penn State) for more than 20 yr. A new experiment has been developed where the students program and operate a computer controller that manipulates the speed of a secondary control rod to regulate TRIGA reactor power. Elementary feedback control theory is introduced to explain the experiment, which emphasizes the nonlinear aspect of reactor control where power level changes are equivalent to a change in control loop gain. Digital control of nuclear reactors has become more visible at Penn State with the replacement of the original analog-based TRIGA reactor control console with a modern computer-based digital control console. Several TRIGA reactor dynamics experiments, which comprise half of the three-credit laboratory course, lead to the control experiment finale: (a) digital simulation, (b) control rod calibration, (c) reactor pulsing, (d) reactivity oscillator, and (e) reactor noise

  5. Reactor System Design

    International Nuclear Information System (INIS)

    SMART NPP(Nuclear Power Plant) has been developed for duel purpose, electricity generation and energy supply for seawater desalination. The objective of this project IS to design the reactor system of SMART pilot plant(SMART-P) which will be built and operated for the integrated technology verification of SMART. SMART-P is an integral reactor in which primary components of reactor coolant system are enclosed in single pressure vessel without connecting pipes. The major components installed within a vessel includes a core, twelve steam generator cassettes, a low-temperature self pressurizer, twelve control rod drives, and two main coolant pumps. SMART-P reactor system design was categorized to the reactor coe design, fluid system design, reactor mechanical design, major component design and MMIS design. Reactor safety -analysis and performance analysis were performed for developed SMART=P reactor system. Also, the preparation of safety analysis report, and the technical support for licensing acquisition are performed

  6. A point mutation in AgrC determines cytotoxic or colonizing properties associated with phenotypic variants of ST22 MRSA strains.

    Science.gov (United States)

    Mairpady Shambat, Srikanth; Siemens, Nikolai; Monk, Ian R; Mohan, Disha B; Mukundan, Santhosh; Krishnan, Karthickeyan Chella; Prabhakara, Sushma; Snäll, Johanna; Kearns, Angela; Vandenesch, Francois; Svensson, Mattias; Kotb, Malak; Gopal, Balasubramanian; Arakere, Gayathri; Norrby-Teglund, Anna

    2016-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is a major cause of skin and soft tissue infections. One of the highly successful and rapidly disseminating clones is MRSA ST22 commonly associated with skin tropism. Here we show that a naturally occurring single amino acid substitution (tyrosine to cysteine) at position 223 of AgrC determines starkly different ST22 S. aureus virulence phenotypes, e.g. cytotoxic or colonizing, as evident in both in vitro and in vivo skin infections. Y223C amino acid substitution destabilizes AgrC-AgrA interaction leading to a colonizing phenotype characterized by upregulation of bacterial surface proteins. The colonizing phenotype strains cause less severe skin tissue damage, show decreased susceptibility towards the antimicrobial LL-37 and induce autophagy. In contrast, cytotoxic strains with tyrosine at position 223 of AgrC cause infections characterized by inflammasome activation and severe skin tissue pathology. Taken together, the study demonstrates how a single amino acid substitution in the histidine kinase receptor AgrC of ST22 strains determines virulence properties and infection outcome. PMID:27511873

  7. 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.).

  8. Fossil nuclear reactors

    Energy Technology Data Exchange (ETDEWEB)

    Maurette, M.

    1976-01-01

    The discussion of fossil nuclear reactors (the Oklo phenomenon) covers the earth science background, neutron-induced isotopes and reactor operating conditions, radiation-damage studies, and reactor modeling. In conclusion possible future studies are suggested and the significance of the data obtained in past studies is summarized. (JSR)

  9. Del hogar agrícola a los maestros queseros. La escuela granja de Tandil (Argentina, 1915-1960

    Directory of Open Access Journals (Sweden)

    Talía Violeta Gutiérrez

    2015-01-01

    Full Text Available La formación de recursos humanos y la generación de conocimientos adaptados a las condiciones de explotación de las diversas produccio-nes regionales en la Argentina ocuparon la atención de los técnicos del Ministerio de Agricultura de la Nación, de las entidades agraristas y de sectores políticos y educativos diversos desde inicios del siglo XX. No escapó a ese interés la preocupación por la mujer y el “hogar agrícola”. En el presente artículo fueron analizadas, en ese contexto, las primeras décadas de la Escuela Granja “Ramón Santamarina” de Tandil, un esta-blecimiento con una rica historia institucional que albergó la primera es-cuela del hogar agrícola del país, transformada pronto en granja-escuela y especializada en industria láctea. El tránsito del “hogar agrícola” a la preparación de maestros queseros -en el marco de la orientación productivista de las escuelas en la pro-puesta educativa del Ministerio-, los sujetos sociales involucrados, la es-pecialización en quesería y sus resultados, son algunas de las cuestiones analizadas. Esto se inserta en el contexto de un proyecto educativo agra-rio pensado no solo como fuente de mano de obra, vinculado a determi-nadas industrias agrarias, sino también –y tal vez más que nada– como irradiador de ese tipo de enseñanzas hacia la comunidad.

  10. Huella hídrica de productos agrícolas producidos en la sierra central y comercializados en Lima

    Directory of Open Access Journals (Sweden)

    Tito Mallma Capcha

    2015-06-01

    Full Text Available El objetivo ha sido determinar un modelo para obtener la huella hídrica de los principales productos agrícolas de la sierra central del Perú que son comercializados en los mercados de la ciudad de Lima, para ello se desarrolló un modelo conceptual que determine el requerimiento de agua de los cultivos que junto a los respectivos rendimientos han permitido establecer el contenido de agua virtual de cada producto agrícola expresado en l/kg; con este resultado y la cantidad de producto comercializado, se han determinado el agua virtual (AV transferida hacia el mercado de Lima, correspondiente a los catorce productos agrícolas considerados. Se obtuvieron valores que indican que los volúmenes de agua virtual entre los productos varían por las cantidades comercializadas y están en función de la producción que a su vez depende de factores como el clima, la demanda del consumidor y de la tecnología empleada en la producción. Así, el consumo de un kg de papa en la ciudad de Lima implica la transferencia de 300,71 litros de “agua virtual” desde la región Junín, donde se produce el producto. El producto que transfiere la mayor cantidad de agua virtual es la papa con 78 069 926,37 m3, seguido de la arveja verde con 16 889 273,96 m3, y el producto que transfiere la menor cantidad es la cebolla con 10 336,59 m3, en tanto que el volumen total de agua virtual transferida es de 165 595 592,28 m3.

  11. Retrospectiva agroecológica a la interacción entre sistemas agrícolas tradicionales y modernos.

    Directory of Open Access Journals (Sweden)

    René Montalva

    2003-05-01

    Full Text Available En este trabajo se realiza un acercamiento desde la agroecología crítica a los orígenes y la expansión de la "agricultura moderna" y a su extensión hacia los sistemas agrícolas  tradicionales del tercer mundo. Asítambién, se analizan los efectos de esta transformación y de la adopción de las prácticas genéricas de la agricultura modema en los sistemas agrícolas familiares, principalmente campesinos e indígenas. Los antecedentes históricos recopilados ponen de manifisto que este proceso ha sido ampliamente desfavorable para los sistemas familiares, particulamente en aspectos económico -productivos, ambientales y sociales; encontrando el origen de gran parte de sus problemas actuales en la expansión de la "nueva agricultura" y en el modelo de desarrollo que hay tras ella. Con el respaldo de argumentos de tipo empírico y teóricos actuales, en este trabajo se concluye que, al igual que lo que ha ocurrido en otros lugares del planeta, la "rnodemización" de los sistemas agrícola familiares, con base tradicional, no dará solución al estado de pobreza material en la cual se encuentran campesinos e indígenas de los países del tercer mundo, sino que por el contrario producirá otros tipos de pobreza y problemas de diversa índole, muchos de ellos con efectos inciertos.

  12. Uso de plaguicidas en cultivos agrícolas como herramienta para el monitoreo de peligros en salud

    OpenAIRE

    Virya Bravo Durán; Elba de la Cruz Malavassi; Gustavo Herrera Ledezma; Fernando Ramírez Muñoz

    2013-01-01

    Costa Rica ha incrementado el uso de plaguicidas de mayor toxicidad, debido entre otras cosas al desarrollo de plagas más resistentes y la necesidad que tienen algunos productos agrícolas de exportación de mantener su posición en el mercado internacional. El ser humano al entrar en contacto con los plaguicidas puede experimentar efectos adversos en su salud desde agudos hasta crónicos que se manifiestan en diferentes grados. Para generar indicadores de peligro en salud en algunos cultivos por...

  13. Lluvia, escurrimiento y producción de sedimentos en una microcuenca agrícola del sistema de Tandilia

    OpenAIRE

    Ares, María Guadalupe

    2014-01-01

    La erosión hídrica es uno de los principales procesos de degradación que afectan a las tierras agrícolas a nivel mundial. Sus efectos tienen consecuencias en el sitio donde ocurre, al disminuir la capacidad productiva de las tierras. Al mismo tiempo ocasionan externalidades, debido a la sedimentación en canales y reservorios y a la contaminación que puede provocar. En Argentina, estadísticas del año 1990 indican que la erosión afecta 30 millones de hectáreas, y recientemente se ha establecido...

  14. Xi congreso nacional de ingeniería agrícola y áreas afines- conferencias magistrales

    OpenAIRE

    Facultad Nacional de Agronomía, Universidad Nacional de Colombia

    2013-01-01

    En este artículo podemos encontrar las conferencias magistrales de XI Congreso Nacional de Ingeniería Agrícola y Áreas Afines en el que se pueden encontrar las siguientes: Automatización en la industria azucarera de Brasil. Este texto presenta una historia resumida del desarrollo de la industria azucarera en Brasil, con énfasis en la producción de alcohol. Se muestra también, la composición de la matriz energética brasilera y la contribución de la energía proveniente de la biomasa, en especia...

  15. Perspectivas do uso de legislaçao na preservaçao do solo agrícola

    OpenAIRE

    Cavalet, Valdo José

    2012-01-01

    O processo de degradação dos recursos naturais e crescente em nosso planeta. Dentre os recursos naturais renováveis, o solo agrícola está perdendo a sua fertilidade num ritmo muito acelerado, sendo considerado o principal problema ambiental da atualidade. A causa mais direta da destruição do solo e o seu uso intensivo, desordenado e desprovido de um manejo adequado. Isto é resultante da prioridade dada pelos governantes a uma política que busca o crescimento econômico a qualquer custo, on...

  16. Segmentación automática de texturas en imágenes agrícolas

    OpenAIRE

    Riomoros Callejo, M. Isabel

    2010-01-01

    En los últimos años, ha aparecido el concepto de Agricultura de Precisión, gracias al desarrollo de las nuevas tecnologías. Esto ha hecho que los problemas surgidos con las prácticas agrícolas tradicionales, tal es el caso de la utilización de herbicidas o el abonado generalizado, se vayan solventando conforme avanzan las investigaciones. En la Agricultura de Precisión se hace especial hincapié en las técnicas orientadas a la aplicación selectiva de tratamientos, es decir, al uso de herbic...

  17. Funciones agua rendimiento para 14 cultivos agrícolas en condiciones del sur de La Habana

    OpenAIRE

    Felicita González Robaina; Julián Herrera Puebla; Teresa López Seijas; Greco Cid Lazo

    2013-01-01

    El estudio de las funciones agua rendimiento y su uso dentro de la planificación del uso del agua es una vía importante para trazar estrategias de manejo que contribuyan al incremento en la producción agrícola. Utilizando los datos de consumo de agua, agua aplicada por riego, precipitaciones y los rendimientos obtenidos en más de 100 experimentos de campo realizados fundamentalmente en suelo Ferralítico Rojo de la zona sur de La Habana y con ayuda de herramientas de análisis de regresión en e...

  18. Efectos del manejo agrícola sobre las aves paseriformes en el olivar mediterráneo

    OpenAIRE

    Castro Caro, Juan Carlos

    2016-01-01

    El olivar es uno de los usos predominantes de tierra en la cuenca mediterránea, donde 5 millones de hectáreas se dedican a este cultivo (la mitad de los cuales están en España), con significativas implicaciones sociales, ambientales y económicos. En las últimas décadas la intensificación agrícola ha llevado a una homogeneización y simplificación de los paisajes tierras de cultivo en toda Europa con consecuencias ambientales negativas. La contaminación del agua, la pérdida de bi...

  19. Nuclear reactor repairing device

    International Nuclear Information System (INIS)

    Purpose: To enable free repairing of an arbitrary position in an LMFBR reactor. Constitution: A laser light emitted from a laser oscillator installed out of a nuclear reactor is guided into a portion to be repaired in the reactor by using a reflecting mirror, thereby welding or cutting it. The guidance of the laser out of the reactor into the reactor is performed by an extension tube depending into a through hole of a rotary plug, and the guidance of the laser light into a portion to be repaired is performed by the transmitting and condensing action of the reflecting mirror. (Kamimura, M.)

  20. 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

  1. 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

  2. Reestructuración agrícola de las familias productoras de maíz: estudio en San Mateo Ayecac, Tlaxcala, 2000-2008.

    Directory of Open Access Journals (Sweden)

    Ma. Concepción Alvarado Méndez

    2011-01-01

    Full Text Available La investigación tiene por objetivo analizar el mecanismo de transformación agrícola expresado en los cambios de la fuerza de trabajo agrícola en términos de su estructura económica así como las principales consecuencias económicas en la comunidad de San Mateo Ayecac, municipio de Tepetitla en el estado de Tlaxcala. Los resultados muestran una transformación de las familias productoras de granos básicos, expresados en el proceso productivo, específicamente en la disminución de labores, fertilización, disminución del trabajo familiar y en el rendimiento. A pesar de ello no existe abandono de la actividad agrícola y sigue siendo la base de la alimentación familiar y un importante abastecedor de alimentos de los mercados locales.

  3. Entre a propriedade e o salário. Memórias dos trabalhos agrícolas em Alpiarça (anos 50/80

    Directory of Open Access Journals (Sweden)

    Dilce Freire

    2006-09-01

    Full Text Available Até aos anos 60 do século XX, Portugal foi um país essencialmente agrícola e rural. O rápido êxodo rural facilitou o abandono ou a transformação da agricultura. Apresenta-se aqui uma reflexão sobre os actuais processos de rememoração das práticas agrícolas numa vila do Ribatejo (Portugal e sobre a amnésia social verificada relativamente ao passado agrícola, que decorre das transformações ocorridas e dos valores sociais e culturais associados à reconstrução da identidade da vila de Alpiarça.

  4. Staphylococcus aureus but not Listeria monocytogenes adapt to triclosan and adaptation correlates with increased fabI expression and agr deficiency

    DEFF Research Database (Denmark)

    Nielsen, Lene Nørby; Larsen, Marianne Halberg; Skovgaard, Sissel;

    2013-01-01

    was initially 4 mg/L and remained unaltered by the exposure. The adapted S. aureus isolates retained normal colony size but displayed increased expression of fabI encoding an essential enzyme in bacterial fatty acid synthesis. Also, they displayed decreased or no expression of the virulence associated agr......C of the agr quorum sensing system. While most adapted strains of USA300 carried mutations in fabI, none of the adapted strains of 8325-4 did. Conclusions. Adaptability to triclosan varies substantially between Gram positive human pathogens. S. aureus displayed an intrinsically lower MIC for triclosan compared...... to L. monocytogenes but was easily adapted leading to the same MIC as L. monocytogenes. Even though all adapted S. aureus strains over-expressed fabI and eliminated expression of the agr quorum sensing system, adaptation in USA300 involved fabI mutations whereas this was not the case for 8325-4. Thus...

  5. Tractor Agrícola - Tomada de força e Serviço Externo do Sistema Hidráulico do Tractor

    OpenAIRE

    Peça, José

    2012-01-01

    Este trabalho destina-se a apoiar a aprendizagem de estudantes do ramo das ciências agrárias no que de relevante se refere ao serviço externo do sistema hidráulico do tractor agrícola. O tractor agrícola dispõe de uma fonte de potência para o exterior denominada tomada-de-força (tdf). É fundamental o conhecimento deste componente, das regulações que permite, dos aspectos de segurança, em particular na fase de ligação dos equipamentos. Será dado relevo aos comandos que na cabina do tractor...

  6. The agr Inhibitors Solonamide B and Analogues Alter Immune Responses to Staphylococccus aureus but Do Not Exhibit Adverse Effects on Immune Cell Functions

    DEFF Research Database (Denmark)

    Baldry, Mara; Kitir, Betül; Frøkiær, Hanne;

    2016-01-01

    Staphylococcus aureus infections are becoming increasingly difficult to treat due to antibiotic resistance with the community-associated methicillin-resistant S. aureus (CA-MRSA) strains such as USA300 being of particular concern. The inhibition of bacterial virulence has been proposed......-virulence candidacy, we report the chemical synthesis of solonamide analogues, investigation of structure-function relationships, and assessment of their potential to modulate immune cell functions. We found that structural differences between solonamide analogues confer significant differences in interference...... as an alternative approach to treat multi-drug resistant pathogens. One interesting anti-virulence target is the agr quorum-sensing system, which regulates virulence of CA-MRSA in response to agr-encoded autoinducing peptides. Agr regulation confines exotoxin production to the stationary growth phase...

  7. Regadíos agrícolas, territorio y desarrollo rural

    Directory of Open Access Journals (Sweden)

    Moyano Estrada, Eduardo

    2008-02-01

    Full Text Available This article analyses how the topics linked to water management have changed in social perception and political agenda in Spain. From a hydraulic and agricultural-oriented logic it has shifted toward other more integral and multifunctional one, where the Ministry of Environment is the most relevant player. In such a social and political context, the new orientations of rural development policies are analysed, particularly in relation to the sustainable management of water resources in farming sector and their implications on territory. The authors propose a typology of irrigable areas in Spain, and analyse the process of implementation of the new European Regulation on Rural Development (Reg. 1690/2005. The conclusion is that this new policy could be a useful tool to promote the environmental sustainability of these areas only if there was a good coordination between agricultural and environmental departments at the regional level.En este artículo se analiza la percepción social y política de los temas relacionados con la gestión del agua en España, mostrando cómo se ha pasado de una lógica hidráulica y sectorial (agraria, canalizada a través de los ministerios de Obras Públicas y Agricultura, a otra integral y multifuncional, en la que se valoran sus implicaciones territoriales y en la que asume protagonismo el ministerio de Medio Ambiente. En ese contexto, se analizan las nuevas orientaciones de las políticas de desarrollo rural, especialmente en lo relacionado con la gestión sostenible de los recursos hídricos en la agricultura y sus efectos sobre el territorio. La diversidad del regadío agrícola en España es analizada por los autores, proponiendo una tipología de zonas regables con problemas de eficiencia, y valorando en qué medida las acciones contempladas en el nuevo Reglamento europeo de Desarrollo Rural (FEADER pueden ser un instrumento útil para avanzar en la sostenibilidad ambiental de dichas áreas. La conclusi

  8. 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.

  9. Políticas de precios y subsidios agrícolas: impactos macroeconómico y sectorial: Perú 1985-1988.

    OpenAIRE

    Javier Escobal

    1989-01-01

    Este documento presenta y analiza las principales políticas aplicadas por el gobierno aprista para reactivar el agro peruano, evaluando su viabilidad financiera de corto y mediano plazo y sus efectos sobre el propio sector agrario y la economía en su conjunto. Describe y analiza la política de precios agrícolas, la política cambiaria y la política crediticia; evalúa los efectos de las políticas macroeconómicas descritas y de los subsidios agrícolas, en especial aquéllos que inciden sobre la i...

  10. Elementos de diseño de maquinaria agrícola: informe de año sabático

    OpenAIRE

    Álvarez Mejía, Fernando

    2007-01-01

    El texto que aquí se presenta se adapta al programa de la asignatura Mecanismos que actualmente viene impartiéndose en la formación de los Ingenieros Agrícolas y servirá de guía al estudio de las máquinas agrícolas para profesiones afines al sector agropecuario. Los estudiantes deberán haber adquirido un conjunto de herramientas de ingeniería que consisten esencialmente de matemáticas, geometría, física y varias de las ciencias básicas como la resistencia de los materiales. Estas herramientas...

  11. Actuaciones de un colector solar de aire para secado de productos agrícolas en países en vías de desarrollo

    OpenAIRE

    Esteban Biescas, Sandra

    2015-01-01

    El uso de secaderos solares para el secado de productos agrícolas es una de las tecnologías apropiadas en crecimiento en los países en vías de desarrollo. En el marco de las tecnologías apropiadas se define el presente Trabajo Fin de Grado para caracterizar el proceso de calentamiento de aire y la capacidad de secado de un secadero solar activo (de convección forzada) de tipo distribuido protegiendo así al máximo los productos agrícolas de los agentes externos. Este sistema se basa en el a...

  12. Sostenibilitat de dos projectes de cooperació al desenvolupament agrícola a Tape Iguapegui (Argentina) i a Celica (Ecuador)

    OpenAIRE

    Bastos Pirra, Ramiro; Simón Bueno, Óscar

    2007-01-01

    Les comunitats camperoles de Tape Iguapegui (Algarrobito en castellà) i Celica agrupen respectivament a 25 i 52 famílies participants en dos projectes de desenvolupament agrícola, “Desarrollo agrícola en Algarrobito”i “Huertas familiars y granges comunitàries en Celica”. L’objectiu d’aquests projectes és millorar els sistemes de maneig agropecuari d’ambdues comunitats, basats principalment en el blat de moro de “Tumba Roza y Quema”. L’objectiu del present treball era evaluar a priori...

  13. Desarrollo de herramientas computacionales para el manejo de bases de datos ambientales. Estudio de caso ecosistema agrícola urbano en el D.F.

    OpenAIRE

    Carreón Barrios, Claudia Evelia

    2015-01-01

    El manejo eficiente de la información ambiental es un tópico de creciente interés en las actividades agrícolas, especialmente en términos del gran volumen de datos que se manejan, la complejidad de los procesos agrícolas y la demandante tarea de adquisición de información. La Ciudad de México no cuenta con bases de datos o herramientas computacionales orientadas hacia el análisis de los sistemas de agricultura urbana y que sustenten la formulación de una mejor toma de decisiones. En este cont...

  14. 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.

  15. Mecanización agrícola ¿Deterioro o conservación del suelo?

    Directory of Open Access Journals (Sweden)

    Armando Alvarado Chaves

    2006-05-01

    Full Text Available “Mecanización agrícola; ¿Deterioro o conservación del suelo?” trata sobre el mito de que la mecanización o preparación de los suelos, en forma mecánica, es el detonante del deterioro de los suelos por erosión sobre todo por erosión hídrica y en menor grado por erosión eólica. La erosión de los suelos puede ser de poca o de gran magnitud, dependiendo de cuatro factores, los cuales se analizan como errores que se cometen en el momento de preparar los suelos. Estos errores son, en realidad, los causantes del deterioro de los suelos por erosión y no la mecanización, ya que esta, bien planificada y aplicada, puede incluso servir para la conservaciónde los suelos y el medio ambiente. También se describen los implementos agrícolas que pueden usarse para reducir la erosión de los suelos, citando su forma de trabajo y algunas de las ventajas del uso de esos implementos.

  16. Potencial de biodegradación de DDT y sus metabolitos en suelos agrícolas de Chinandega

    Directory of Open Access Journals (Sweden)

    Carlos E. Noguera Solís

    2008-04-01

    Full Text Available LA PRESENTE INVESTIGACIÓN EVALUÓ EL POTENCIAL DE BIODEGRADACIÓN DEL 1,1,1-Tricloro- 2,2-bis(4-clorofeniletano (DDT y sus metabolitos en suelos agrícolas pertenecientes a fincas del municipio de El Viejo, Chinandega, a través de dos ensayos: ensayo de biodegradación ex situ y ensayo de búsqueda e identificación de microorganismos capaces de biodegradar DDT. En el primer ensayo se determinó el porcentajede biodegradación, bajo condiciones idóneas, durante un período de 100 días en diferentes lotes de suelo con diferentes aditivos (cachaza y estiércol a través de la aplicación de cepas microbianas comerciales Environoc 201®. De ello se obtuvo como resultado un porcentaje de biodegradación mayor para el lote que no presentaba aditivos orgánicos, siendo éste de 23,92%. En el ensayo de búsqueda eidentificación de bacterias se lograron aislar e identificar cepas microbianas nativas de los suelos agrícolas objeto de estudio utilizando medios de cultivo con DDT como única fuente de carbono y energía. Como resultado se lograron identificar los siguientes microorganismos: Pseudomonas sp., Streptomyces sp., Phanerochaetechrysosporium y levaduras.

  17. Mecanización agrícola, empleo y migración en el norte de Tamaulipas

    Directory of Open Access Journals (Sweden)

    José Luis Contreras Valenzuela

    1986-05-01

    Full Text Available El objetivo del presente trabajo es analizar el modelo de desarrollo agrícola recientemente adoptado en los distritos de riego del norte de Tamaulipas, y los efectos sobre el empleo y la migración de la población rural. Dicho análisis se efectuará a partir de dos premisas fundamentales: una de ellas es la internacionalización del proceso productivo que se manifiesta con la presencia de una nueva división internacional del trabajo y lo que en este ensayo es llamada economía campesina, que fue la fuente primaria de la acumulación de capital de la agricultura mexicana, la cual jugará un papel importante para la acumulación de capital de la agricultura de los Estados Unidos de América, mediante la oferta de fuerza de trabajo agrícola barata, permitiendo el desarrollo de la agricultura comercial, modelo que ahora se ha volcado sobre la economía campesina condenándola a su desaparición como forma de subsistencia de la población rural, a quien expulsa de sus unidades de producción mediante el acaparamiento y el rentismo.

  18. La sucesión "mortis causa" en la explotación agrícola familiar

    Directory of Open Access Journals (Sweden)

    José Luis De Los Mozos

    2015-01-01

    Full Text Available Llevo nada menos que cuarenta años dando vueltas al tema de la sucesión mortis causa en el Derecho agrario y más concretamente, al de la sucesión en la explotación agrícola. Esto no constituye ningún mérito, naturalmente, no es más que una mera circunstancia que acredita, cuando mucho, la firmeza de una convicción. Durante este tiempo, con mayor o menor contacto con la realidad social, he seguido y sigo fiel a mis puntos de vista originarios; no es que nada haya cambiado en todos estos años, sino que ha cambiado casi todo.Pero es que las soluciones que me parecían entonces muy dudosas, ahora me parecen inadmisibles.La evolución económica y social, ha puesto de relieve que las ideas que se utilizaban hace medio siglo en la materia, actualmente han quedado obsoletas (...Contenido: Una distinción obligada y un recuerdo inevitable. El recurso a la atribución preferente. Las condicionantes de la atribución preferente. El concepto de explotación agrícola. La reforma del derecho sucesorio como recapitulación

  19. Convergencia espacial y concentración regional agrícola en México 1970-2003

    Directory of Open Access Journals (Sweden)

    Normand Eduardo Asuad Sanén

    2007-01-01

    Full Text Available El propósito de este trabajo es analizar la relación entre convergencia tradicional y espacial del ingreso según la concentración regional de la producción agrícola de México, destacando los efectos propiciados por el cambio del modelo de desarrollo y gestión, mediante la liberalización y privatización de la economía con su incorporación al TLCAN y su comparación con el periodo 1970-2004. Se identifican y delimitan las regiones agrícolas a las que se aplica la medición econométrica de las hipótesis de convergencia tradicional, espacial y de la concentración económica. Los resultados confirman la tendencia a la disparidad del ingreso de esas regiones y el papel de la concentración económica como determinante de su comportamiento, asociado a la política de apertura de la economía mexicana.

  20. Realidad y derecho sobre los conocimientos tradicionales: especial referencia al sector agrícola en Cuba

    Directory of Open Access Journals (Sweden)

    Yeney Acea Valdés

    2014-06-01

    Full Text Available Los conocimientos tradicionales agrícolas adolecen de los presupuestos teórico- legales que garanticen una protección específica en Cuba, lo que genera perjuicios morales y patrimoniales en la esfera social y en la de sus legítimos poseedores. De ahí que el objetivo haya sido establecer dichos presupuestos. Los métodos empleados fueron, el jurídico- comparado, el jurídico- analítico y el análisis bibliográfico de textos clásicos y modernos. Los resultados obtenidos fueron la comparación de los sistemas de protección existentes, el análisis de las ventajas y desventajas de las formas de protección existentes, los presupuestos teórico- legales a tener en cuenta en futuras regulaciones y un material bibliográfico de consulta. A partir de la metodología empleada asumimos el criterio de que una correcta delimitación conceptual permitirá la adecuación de las normas a fin de garantizar algún tipo de protección y con ello la revalorización del trabajo agrícola.

  1. Modernização da Agricultura em Moçambique: determinantes da renda agrícola

    Directory of Open Access Journals (Sweden)

    Carlos E. Guanziroli

    2015-03-01

    Full Text Available O objetivo deste trabalho é verificar até que ponto as tecnologias oriundas da revolução verde foram efetivamente adotadas na África Subsaariana e, nos casos em que foram adotadas, se tiveram sucesso em melhorar a renda e a produtividade da agricultura. Para este fim, o trabalho faz primeiramente um breve resumo do estado das artes da revolução verde na África, mostrando quais países avançaram mais e como se correlaciona a utilização de fertilizantes químicos com os aumentos de produtividade. Faz-se também uma discussão sobre as características do processo de intensificação num caso em particular, o de Moçambique. Finalmente, com base nos microdados do Tratado de Inquérito Agrícola (TIA, se testa um modelo econométrico de MQO que visa avaliar os determinantes da renda agrícola e, em particular, do uso de fertilizantes químicos.

  2. Ablation de ZnO par laser UV (193 nm) : nano-agrégats en phase gazeuse

    Science.gov (United States)

    Ozerov, I.; Bulgakov, A.; Nelson, D.; Castell, R.; Sentis, M.; Marine, W.

    2003-06-01

    La condensation de nano-agrégats d'oxyde de zinc en phase gazeuse est mise en évidence lors de l'ablation de ZnO massif par laser ArF pulsé. Nous comparons l'évolution spatio-temporelle de la forme du panache d'ablation (plume) de ZnO sous vide et sous atmosphère de gaz de couverture (oxygène et/ou hélium) à partir des images CCD et des résultats issus d'analyses spectroscopiques. L'expansion du plasma et la croissance des nano-clusters sont influencées par l'effet du confinement de la plume dû aux collisions entre les particules ablatées et les molécules de gaz ambiant ainsi que par les réactions chimiques dans le cas de l'oxygène. Le spectre de rayonnement du plasma est constitué principalement par l'émission d'atomes excités de Zn neutre. Nous avons observé la photoluminescence des nano-agrégats en suspension dans le gaz ainsi que leur décomposition par laser ArF.

  3. 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...

  4. Multipurpose research reactors

    International Nuclear Information System (INIS)

    The international symposium on the utilization of multipurpose research reactors and related international co-operation was organized by the IAEA to provide for information exchange on current uses of research reactors and international co-operative projects. The symposium was attended by about 140 participants from 36 countries and two international organizations. There were 49 oral presentations of papers and 24 poster presentations. The presentations were divided into 7 sessions devoted to the following topics: neutron beam research and applications of neutron scattering (6 papers and 1 poster), reactor engineering (6 papers and 5 posters), irradiation testing of fuel and material for fission and fusion reactors (6 papers and 10 posters), research reactor utilization programmes (13 papers and 4 posters), neutron capture therapy (4 papers), neutron activation analysis (3 papers and 4 posters), application of small reactors in research and training (11 papers). A separate abstract was prepared for each of these papers. Refs, figs and tabs

  5. State, Bank and Agricultural Credit in Sinaloa and Sonora: The Banco de Sinaloa and Banco Agrícola Sonorense, 1933-1976 Estado, banca y crédito agrícola en Sinaloa y Sonora: El Banco de Sinaloa y el Banco Agrícola Sonorense, 1933-1976

    Directory of Open Access Journals (Sweden)

    Gustavo Aguilar Aguilar

    2011-01-01

    Full Text Available In the Northwest of México the increase in the agricultural productivity in the years between 1940 and 1970, was due to the expansion of the farming lands, the use of improved seeds and fertilizer, mechanization, the greater availability of credit, the irrigation system and road improvement. The important intervention from the Mexican state to implement policies of investment with the support of internationally development agencies, and grant credit facilities for the development of agriculture trough the creation of official agricultural banks and the facilities to the constitution of private commercial banks. After the disarticulation of the bank in México due to the revolution, is advanced with steady steps in restructuring the banking system with the creation of a new banking law, the foundation of Banco de México and the Comision Nacional Bancaria in 1924; Banco Nacional de Credito Agricola (1926, the Banco Nacional de Credito Ejidal (1935, Banco Nacional de Comercio Exterior (1937 and the Banco Nacional Agropecuario (1965, which gave financial support to small farmers and ejidatarios (members of a cooperative. The main farmers of Sinaloa and Sonora in collaboration with the federal government through the Comision Monetaria and the Banco de México founded the Banco de Sinaloa and Banco Agricola Sonorense in 1933. Explain the impact these financial institutions had in the agricultural credit of Sinaloa and Sonora will be the central objective of this work.En el Noroeste de México el incremento en la productividad agrícola entre los años de 1940 y 1970, fue debido a la expansión de las tierras de cultivo, el uso de fertilizantes y semillas mejoradas, la mecanización, la mayor disponibilidad de créditos, a los sistemas de irrigación y el mejoramiento de las carreteras. Así como la importante intervención del Estado mexicano al implementar políticas de inversión con el apoyo de agencias internacionales de desarrollo, y otorgar

  6. Reactor BR2

    Energy Technology Data Exchange (ETDEWEB)

    Gubel, P

    2000-07-01

    The BR2 reactor is still SCK-CEN's most important nuclear facility. After an extensive refurbishment to compensate for the ageing of the installation, the reactor was restarted in April 1997. Various aspects concerning the operation of the BR2 Reactor, the utilisation of the CALLISTO loop and the irradiation programme, the BR2 R and D programme and the production of isotopes and of NTD-silicon are discussed. Progress and achievements in 1999 are reported.

  7. The Integral Fast Reactor

    International Nuclear Information System (INIS)

    The Integral Fast Reactor (IFR) is an innovative liquid metal reactor concept being developed at Argonne National Laboratory. It seeks to specifically exploit the inherent properties of liquid metal cooling and metallic fuel in a way that leads to substantial improvements in the characteristics of the complete reactor system. This paper describes the key features and potential advantages of the IFR concept, with emphasis on its safety characteristics. 3 refs., 4 figs., 1 tab

  8. Reactor Engineering Division annual report

    International Nuclear Information System (INIS)

    Research and development activities in the Division of Reactor Engineering in fiscal 1981 are described. The work of the Division is closely related to development of multipurpose Very High Temperature Gas Cooled Reactor and fusion reactor, and development of Liquid Metal Fast Breeder Reactor carried out by Power Reactor and Nuclear Fuel Development Corporation. Contents of the report are achievements in fields such as nuclear data and group constants, theoretical method and code development, integral experiment and analysis, shielding, reactor and nuclear instrumentation, reactor control and diagnosis, and fusion reactor technology, and activities of the Committee on Reactor Physics. (author)

  9. 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.)

  10. A user's guide to COMULIP (a program for determining brick movements in an AGR core)

    International Nuclear Information System (INIS)

    COMULIP (COre Movements Using LInear Programming) is a set of computer programs which allows the user to find the maximum movements of bricks in a layer of 16 sided polygonal bricks and 4 sided interstitial bricks, as in the core of the Hinkley 'B' Advanced Gas Cooled Reactor. The user supplies the dimensions of the bricks and keys, the boundary constraints and specifies the brick and direction for which the maximum movement is to be found. To facilitate data input, a standard set of dimensions is entered together with individual brick dimensions which differ. The linear programming method is used to maximise an objective function, which in this case is the movement of a specified brick in a given direction, subject to a set of linear constraints, which define the geometrical condition that no brick should overlap. The elasticity of the bricks is not taken into account, the effect of this being small compared with that of the clearances. The model analysed is a two dimensional horizontal cross-section through the core. This report forms the user's guide to the computer programs and gives details of the input data required and the output produced, as well as a brief description of the solution technique. The program may be used to study the effect of dimensional changes and brick or key damage, which occur during the lifetime of the reactor, on the movement of bricks. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-05-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-05-01

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

  13. Agravos respiratórios decorrentes da atividade agrícola Respiratory health hazards in agricultural activities

    Directory of Open Access Journals (Sweden)

    CARLOS A.A. VIEGAS

    2000-04-01

    Full Text Available As doenças respirat��rias são um importante problema crítico para trabalhadores rurais, uma vez constatada evidência de aumento significativo do risco de morbidade e mortalidade, por problemas respiratórios, em trabalhadores agrícolas. Este fato é de grande importância especialmente nos países em desenvolvimento, onde grande parte da população depende da agricultura como fonte de subsistência. Sabidamente, pessoas envolvidas em atividades agrícolas estão potencialmente expostas a vários agentes como poeira inorgânica do solo, poeira orgânica, gases tóxicos, pesticidas, etc. O aparelho respiratório pode reagir a estes insultos ao nível de vias aéreas superiores com rinite, sinusite e otite. As vias aéreas inferiores podem responder desencadeando ou agravando asma brônquica, com o quadro conhecido como síndrome asthma-like, com obstrução crônica e lesões causadas por poeira orgânica, pneumonite por hipersensibilidade e fibrose intersticial. Assim, se faz necessário uma identificação precisa dos possíveis agentes etiológicos e conseqüentes medidas profiláticas das doenças respiratórias decorrentes da atividade agrícola.Respiratory diseases are today an important clinical problem for agricultural workers since many studies have demonstrated a significantly increased risk of respiratory morbidity and mortality. This is also important as a public health problem, specially in many developing countries where over half of the work force is involved in agriculture. The rural workers have potential inhalatory exposure to a very wide range of agents like organic and inorganic dust, decomposition gases, pesticides, disinfectants, etc. The impact on the respiratory system varies considerably and may affect all the airways and the pulmonary interstitium and may be associated to rhinitis, asthma, asthma-like syndrome, chronic airway disease, organic dust toxic syndrome, hypersensitivity pneumonitis, and interstitial

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

    International Nuclear Information System (INIS)

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

  15. Structure of the Staphylococcus aureus AgrA LytTR Domain Bound to DNA Reveals a Beta Fold with an Unusual Mode of Binding

    Energy Technology Data Exchange (ETDEWEB)

    Sidote,D.; Barbieri, C.; Wu, T.; Stock, A.

    2008-01-01

    The LytTR domain is a DNA-binding motif found within the AlgR/AgrA/LytR family of transcription factors that regulate virulence factor and toxin gene expression in pathogenic bacteria. This previously uncharacterized domain lacks sequence similarity with proteins of known structure. The crystal structure of the DNA-binding domain of Staphylococcus aureus AgrA complexed with a DNA pentadecamer duplex has been determined at 1.6 Angstroms resolution. The structure establishes a 10-stranded {beta} fold for the LytTR domain and reveals its mode of interaction with DNA. Residues within loop regions of AgrA contact two successive major grooves and the intervening minor groove on one face of the oligonucleotide duplex, inducing a substantial bend in the DNA. Loss of DNA binding upon substitution of key interacting residues in AgrA supports the observed binding mode. This mode of protein-DNA interaction provides a potential target for future antimicrobial drug design.

  16. Comparative analysis of agr groups and virulence genes among subclinical and clinical mastitis Staphylococcus aureus isolates from sheep flocks of the Northeast of Brazil.

    Science.gov (United States)

    de Almeida, Lara M; de Almeida, Mayra Zilta P R B; de Mendonça, Carla L; Mamizuka, Elsa M

    2013-01-01

    Staphylococcus aureus is one of the most frequent mastitis causative agents in small ruminants. The expression of most virulence genes of S. aureus is controlled by an accessory gene regulator (agr) locus. This study aimed to ascertain the prevalence of the different agr groups and to evaluate the occurrence of encoding genes for cytotoxin, adhesins and toxins with superantigen activity in S. aureus isolates from milk of ewes with clinical and subclinical mastitis in sheep flocks raised for meat production The agr groups I and II were identified in both cases of clinical and subclinical mastitis. Neither the arg groups III and IV nor negative agr were found. The presence of cflA gene was identified in 100% of the isolates. The frequency of hla and lukE-D genes was high - 77.3 and 82.8%, respectively and all isolates from clinical mastitis presented these genes. The sec gene, either associated to tst gene or not, was identified only in isolates from subclinical mastitis. None of the following genes were identified: bbp, ebpS, cna, fnbB, icaA, icaD, bap, hlg, lukM-lukF-PV and se-a-b-d-e.

  17. Comparative analysis of agr groups and virulence genes among subclinical and clinical mastitis Staphylococcus aureus isolates from sheep flocks of the Northeast of Brazil.

    Science.gov (United States)

    de Almeida, Lara M; de Almeida, Mayra Zilta P R B; de Mendonça, Carla L; Mamizuka, Elsa M

    2013-01-01

    Staphylococcus aureus is one of the most frequent mastitis causative agents in small ruminants. The expression of most virulence genes of S. aureus is controlled by an accessory gene regulator (agr) locus. This study aimed to ascertain the prevalence of the different agr groups and to evaluate the occurrence of encoding genes for cytotoxin, adhesins and toxins with superantigen activity in S. aureus isolates from milk of ewes with clinical and subclinical mastitis in sheep flocks raised for meat production The agr groups I and II were identified in both cases of clinical and subclinical mastitis. Neither the arg groups III and IV nor negative agr were found. The presence of cflA gene was identified in 100% of the isolates. The frequency of hla and lukE-D genes was high - 77.3 and 82.8%, respectively and all isolates from clinical mastitis presented these genes. The sec gene, either associated to tst gene or not, was identified only in isolates from subclinical mastitis. None of the following genes were identified: bbp, ebpS, cna, fnbB, icaA, icaD, bap, hlg, lukM-lukF-PV and se-a-b-d-e. PMID:24294245

  18. Eficiência energética de um trator agrícola utilizando duas configurações de tomada de potência

    Directory of Open Access Journals (Sweden)

    Ulisses Giacomini Frantz

    2014-07-01

    Full Text Available A tomada de potência (TDP de um trator agrícola tem por principal finalidade transmitir a potência gerada no motor, para acionamento de órgãos ativos das máquinas agrícolas. Tendo em vista a necessidade de se aumentar a eficiência energética na agricultura, alguns fabricantes disponibilizam para os agricultores uma configuração de TDP que proporciona o acionamento dessas máquinas a um regime de rotação menor do motor do trator. Assim, a rotação da TDP é mantida podendo-se obter uma redução do consumo de combustível. Este trabalho objetivou quantificar o consumo de combustível de um trator agrícola, operando com duas configurações de TDP (normal e econômica em duas áreas agrícolas de relevo distinto. Como resultado, evidencia-se que, com a utilização da TDP econômica, tanto o consumo horário quanto o consumo operacional de combustível, em ambas as áreas trabalhadas, foi menor quando comparado à TDP normal.

  19. Medida do ângulo horizontal de ataque dos discos de grades agrícolas de dupla ação e aplicação a uma propriedade agrícola

    Directory of Open Access Journals (Sweden)

    Rubismar Stolf

    2010-01-01

    Full Text Available O conhecimento do ângulo de ataque de grades agrícolas é importante, pois o mesmo influencia a exigência em força de tração, a profundidade e a qualidade da gradagem. O objetivo deste trabalho foi desenvolver um método de medida do ângulo horizontal, de ataque, dos discos de grades de dupla ação com as seguintes características: rápido, de fácil medida e preciso, para aplicação no local de trabalho das grades. O princípio do método proposto baseia-se no fato de que é possível circunscrever grades de dupla ação em um trapézio isósceles e no teorema da trigonometria no qual ângulos com lados perpendiculares entre si formam ângulos iguais. Assim, o método desenvolvido pode ser enunciado como segue: "o seno do ângulo de ataque de uma grade de dupla ação é igual à diferença entre a base maior e a base menor dividida por duas vezes o lado do trapézio". Dessa forma, três medidas de comprimento realizadas com uma trena, ou seja, base maior, base menor e o lado do trapézio, permitem determinar o valor do seno e, consequentemente, o próprio ângulo de ataque da grade. Foram levantados os ângulos de ataque de onze grades agrícolas de propriedade da Destilaria Londra, de Itaí, estado de São Paulo, comprovando a rapidez e facilidade de utilização do método.

  20. Levels of alpha-toxin correlate with distinct phenotypic response profiles of blood mononuclear cells and with agr background of community-associated Staphylococcus aureus isolates.

    Science.gov (United States)

    Mairpady Shambat, Srikanth; Haggar, Axana; Vandenesch, Francois; Lina, Gerard; van Wamel, Willem J B; Arakere, Gayathri; Svensson, Mattias; Norrby-Teglund, Anna

    2014-01-01

    Epidemiological studies of Staphylococcus aureus have shown a relation between certain clones and the presence of specific virulence genes, but how this translates into virulence-associated functional responses is not fully elucidated. Here we addressed this issue by analyses of community-acquired S. aureus strains characterized with respect to antibiotic resistance, ST types, agr types, and virulence gene profiles. Supernatants containing exotoxins were prepared from overnight bacterial cultures, and tested in proliferation assays using human peripheral blood mononuclear cells (PBMC). The strains displayed stable phenotypic response profiles, defined by either a proliferative or cytotoxic response. Although, virtually all strains elicited superantigen-mediated proliferative responses, the strains with a cytotoxic profile induced proliferation only in cultures with the most diluted supernatants. This indicated that the superantigen-response was masked by a cytotoxic effect which was also confirmed by flow cytometry analysis. The cytotoxic supernatants contained significantly higher levels of α-toxin than did the proliferative supernatants. Addition of α-toxin to supernatants characterized as proliferative switched the response into cytotoxic profiles. In contrast, no effect of Panton Valentine Leukocidin, δ-toxin or phenol soluble modulin α-3 was noted in the proliferative assay. Furthermore, a significant association between agr type and phenotypic profile was found, where agrII and agrIII strains had predominantly a proliferative profile whereas agrI and IV strains had a predominantly cytotoxic profile. The differential response profiles associated with specific S. aureus strains with varying toxin production could possibly have an impact on disease manifestations, and as such may reflect specific pathotypes.

  1. Metodologías para establecer valores de referencia de metales pesados en suelos agrícolas: Perspectivas para Colombia

    Directory of Open Access Journals (Sweden)

    Rueda Saa Germán

    2011-09-01

    Full Text Available

    Los problemas ambientales de los metales pesados en los suelos están relacionados con su carácter tóxico cuando se acumulan o cuando interactüan con algunas propiedades especificas, se movilizan a  través del perfil a la cadena trófica mediante los cuerpos de agua o los cultivos y pueden llegar a afectar la salud humana. En países desarrollados el establecimiento de valores de referencia de estos metales ha permitido el mejoramiento de la planeación y la gestión ambiental del recurso suelo, y se ha convertido en un instrumento de control para las entidades ambientales que ha permitido evaluar el impacto en diferentes actividades agrícolas.

    En este artículo se analizan diferentes conceptos relacionados con los niveles de metales pesados en suelos agrícolas y la incidencia de las características edafológicas en su concentración. Se revisan, igualmente, algunas metodologias para derivar valores de referencia especificos aplicables a suelos agrícolas colombianos, y se plantean algunas perspectivas orientadas a la protección y recuperación de suelos en el país. En Colombia en la actualidad no se cuenta con criterios y estándares de calidad para metales pesados en suelos agrícolas; por esto se hace necesario gestionar el apoyo de entidades gubernamentales con el fin de iniciar y desarrollar investigaciones en diferentes sectores agricolas primarios, contribuyendo de esta forma a garantizar la producción agrícola y la sostenibilidad ambiental del recurso suelo.

  2. Metodologías para establecer valores de referencia de metales pesados en suelos agrícolas: perspectivas para Colombia

    Directory of Open Access Journals (Sweden)

    Germán Rueda Saa

    2011-07-01

    Full Text Available Los impactos ambientales de los metales pesados en los suelos están relacionados con su carácter tóxico cuando se acumulan o interactúan con algunas propiedades específicas, se movilizan a través del perfil a la cadena trófica mediante los cuerpos de agua o los cultivos y pueden llegar a afectar la salud humana. En países desarrollados el establecimiento de valores de referencia de estos metales ha permitido el mejoramiento de la planeación y la gestión ambiental del recurso suelo, y se ha convertido en un instrumento de control para las entidades ambientales que ha permitido evaluar el impacto en diferentes actividades agrícolas. En este artículo se analizan diversos conceptos relacionados con los niveles de metales pesados en suelos agrícolas y la incidencia de las características edafológicas en su concentración. Se revisan, igualmente, algunas metodologías para derivar valores de referencia específicos aplicables a suelos agrícolas colombianos, y se plantean algunas perspectivas orientadas a la protección y recuperación de suelos en el país. En Colombia en la actualidad no se cuenta con criterios y estándares de calidad para medir la contaminación por metales pesados en suelos agrícolas; por esto se hace necesario gestionar el apoyo de entidades gubernamentales con el fin de iniciar y desarrollar investigaciones en diferentes sectores agrícolas primarios, contribuyendo de esta forma a garantizar una producción más limpia y la sostenibilidad ambiental del recurso suelo.

  3. One piece reactor removal

    International Nuclear Information System (INIS)

    Japan Research Reactor No.3 (JRR-3) was the first reactor consisting of 'Japanese-made' components alone except for fuel and heavy water. After reaching its initial critical state in September 1962, JRR-3 had been in operation for 21 years until March 1983. It was decided that the reactor be removed en-bloc in view of the work schedule, cost and management of the reactor following the removal. In the special method developed jointly by the Japanese Atomic Energy Research Institute and Shimizu Construction Co., Ltd., the reactor main unit was cut off from the building by continuous core boring, with its major components bound in the block with biological shield material (heavy concrete), and then conveyed and stored in a large waste store building constructed near the reactor building. Major work processes described in this report include the cutting off, lifting, horizontal conveyance and lowering of the reactor main unit. The removal of the JRR-3 reactor main unit was successfully carried out safely and quickly by the en-block removal method with radiation exposure dose of the workers being kept at a minimum. Thus the high performance of the en-bloc removal method was demonstrated and, in addition, valuable knowhow and other data were obtained from the work. (Nogami, K.)

  4. 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)

  5. 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.

  6. Mecanización agrícola ¿Deterioro o conservación del suelo?

    OpenAIRE

    Armando Alvarado Chaves

    2006-01-01

    “Mecanización agrícola; ¿Deterioro o conservación del suelo?” trata sobre el mito de que la mecanización o preparación de los suelos, en forma mecánica, es el detonante del deterioro de los suelos por erosión sobre todo por erosión hídrica y en menor grado por erosión eólica. La erosión de los suelos puede ser de poca o de gran magnitud, dependiendo de cuatro factores, los cuales se analizan como errores que se cometen en el momento de preparar los suelos. Estos errores son, en realidad, los ...

  7. Plano de marketing Casa Agrícola Condes de Seia, S.A. 2012-2013

    OpenAIRE

    Manoel, Carolina Maria Santiago D'Orey

    2012-01-01

    Mestrado em Marketing O plano de marketing apresentado neste trabalho refere-se à Casa Agrícola Condes de Seia, S.A.. Tem como principais objectivos o aumento de vendas bem como a manuten-ção de relacionamentos duradouros, mutuamente vantajosos, com associações de produ-tores e com clientes que operam nesta área. O plano contém uma breve descrição da empresa, seguida da análise da situação. Esta inclui as análises interna e externa, missão, objectivos, ramos de actividade, análise SWOT,...

  8. Fuentes de crecimiento del empleo en el sector agrícola del norte de México

    Directory of Open Access Journals (Sweden)

    José Alberto Salazar García

    2001-01-01

    Full Text Available El desempleo de mano de obra es uno de los problemas más agudos que actualmente enfrentan las zonas rurales de México. Con la finalidad de determinar cómo el cambio en la estructura productiva del sector agrícola del norte de México ha afectado el empleo rural de la región, se calculan las fuentes de crecimiento del empleo de mano de obra de 1991 a 1998. Los resultados indican que en Baja California, Chihuahua y Sonora el cambio en la estructura productiva fue positivo al empleo, mientras que en Coahuila, Sinaloa y Tamaulipas fue negativo. A nivel regional el cambio en la estructura productiva fue desfavorable al empleo; sin embargo, de 1991 a 1998 éste creció en 7.5 millones de jornadas a causa de un aumento en la superficie cosechada en 382 mil hectáreas.

  9. Staphylococcus epidermidis recovered from indwelling catheters exhibit enhanced biofilm dispersal and "self-renewal" through downregulation of agr

    DEFF Research Database (Denmark)

    Dai, Lu; Yang, Liang; Parsons, Chris;

    2012-01-01

    Background: In recent years, Staphylococcus epidermidis (Se) has become a major nosocomial pathogen and the most common cause of infections of implanted prostheses and other indwelling devices. This is due in part to avid biofilm formation by Se on device surfaces. However, it still remains unknown...... that how the process of Se biofilm development is associated with relapsed infection in such patients.Results: We have identified clinical Se isolates displaying enhanced biofilm dispersal and self-renewal relative to reference strain. These isolates also exhibit enhanced initial cell attachment...... these features.Conclusions: Collectively, these data reveal the role of agr system in long-term biofilm development and pathogenesis during Se caused indwelling devices-related relapsed infection....

  10. Centre d’Investigació i Capacitació Agrària al Clot del Moro

    OpenAIRE

    Torras Montfort, Marc

    2012-01-01

    CICA neix amb la intenció de reanimar el Clot del Moro (Castella de n'Hug), partint d’una forta re-programació i seguint amb una proposta arquitectònica atrevida. La reprogramació del lloc mitjançant l’Escola de Capacitació Agrària i el Centre de Recerca, és clau per a la reanimació del lloc, ja que a part de ser viable pel lloc, aporten vida al llarg de tot el any al Centre. L’escola juntament amb la residència, ofereixen un ús diari del centre, compatible al mateix temps amb l’ús d...

  11. Pertinencia social, evaluación y acreditación del agrónomo mexicano

    OpenAIRE

    Liberio Vicorino Ramírez; Gisela Judith Flores Leyva

    2004-01-01

    El objetivo del presente artículo es hacer una contribución a las propuestas sobre la formación de los profesionales de la agronomía, así como destacar el papel que en ellas juegan las diferentes vertientes que se conocen sobre la formación profesional del ingeniero agrónomo en México, en el contexto de la globalización y su consecuente pertinencia social. De manera complementaria, el propósito de este trabajo también es destacar la importancia de los procesos de evaluación y acreditación en ...

  12. Máquinas Agrícolas Automotrizes - Máquinas automotrizes na colheita da uva e da azeitona

    OpenAIRE

    Peça, José

    2012-01-01

    Este trabalho é destinado a apoiar a aprendizagem de estudantes do ramo das ciências agrárias no que de relevante se refere à máquina automotriz de vindimar. O começo da mecanização da vindima data dos anos 70 do século XX. A grande divulgação desta tecnologia é sinónimo de um processo que não afecta a qualidade do produto final. A reduzida incidência enológica da colheita mecânica é largamente compensada pela grande liberdade na escolha de datas de colheita e horários de trabalho, em sum...

  13. Evaluación de residuos agrícolas para la producción del hongo Pleurotus ostreatus

    Directory of Open Access Journals (Sweden)

    María Bernarda Ruilova Cueva

    2014-01-01

    Full Text Available Se caracterizaron los residuos agrícolas de la provincia de Bolívar, Ecuador, desde el punto de vista de su composición físico-química para su empleo en el cultivo del hongo Pleurotus ostreatus. Los residuos agrícolas utilizados fueron: maíz, trigo, cebada, lenteja, bagazo de caña de azúcar y cascarilla de arroz. Se realizaron análisis de: humedad, cenizas, extracto etéreo, proteína, fibra, extracto libre de nitrógeno, fibra detergente neutra, fibra detergente ácida, lignina, celulosa, hemicelulosa y minerales. Los residuos presentaron valores de humedad entre 9,12 y 13,91 %, después de dos meses de almacenamiento. Por su naturaleza leñosa son ricos en fibra, celulosa, lignina y hemicelulosa. El contenido de carbono fluctuó entre 50,12 y 56,55 %, y es la fuente directa de energía para su metabolismo. El contenido de nitrógeno fue variable 0,38-1,29 %. Se cultivó el hongo en los sustratos analizados y en la producción obtenida se valoró la eficiencia biológica y proteína. Se obtuvo en la mayoría de los casos una relación directa entre el contenido de nitrógeno con la eficiencia biológica y la proteína en el hongo.

  14. Cooperativa-escola nas Escolas Técnicas Agrícolas Cooperative-school at the Agricultural Technical Schools

    Directory of Open Access Journals (Sweden)

    P.V. Marques

    1993-12-01

    Full Text Available A dificuldade de gerenciar recursos e proporcionar melhores condições de ensino para os estudantes são algumas das deficiência das Escolas Técnicas Agrícolas (ETAs brasileiras, problemas parcialmente superados por algumas escolas que adotaram a chamada Cooperativa-Escola. Neste trabalho, procura-se discutir alguns aspectos filosóficos referentes às ETAs e como a Cooperativa-Escola pode ajudar a solucionar seus principais problemas educativos e administrativos; um estudo de caso utilizando-se a técnica de auditoria administrativa foi desenvolvido numa ETA cuja Cooperativa-Escola é considerada um modelo de bom funcionamento e alguns procedimentos foram descritos, objetivando-se estender a prática de Cooperativa-Escola para outras escolas técnicas agrícolas brasileiras.Some of the problems with the Brazilian public Agricultural Technical School systems (ETAs are related to resource management and the need to improve teaching and learning conditions. Those deficiencies were partially corrected after setting up Cooperative-Schools that allow the ETAs to raise and to administrate funds. Administrative procedures of the ETAs and how the Cooperative-School could help solving their main educational and adminsitrative problems are discussed in this research. A case study using the management audit technique was developed in one ETA with a well known Cooperative-School. Some observed procedures are described with the intention of extending the practice of Cooperative-Schools to other Brazilian Agricultural Technical Schools.

  15. Detecção de áreas agrícolas em tempo quase real com imagens Modis

    Directory of Open Access Journals (Sweden)

    Isaque Daniel Rocha Eberhardt

    2015-07-01

    Full Text Available Resumo: O objetivo deste trabalho foi desenvolver um método para identificação e monitoramento, em tempo quase real, de áreas agrícolas cultivadas com lavouras temporárias de verão, com uso de imagens orbitais Modis, no Estado do Rio Grande do Sul. A metodologia foi denominada detecção de áreas agrícolas em tempo quase real (DATQuaR e utiliza imagens do sensor Modis referentes aos índices de vegetação (IVs EVI e NDVI, disponibilizadas em composições de 16 dias. Foram utilizadas quatro métricas para agregar os valores de IVs por pixel, dentro dos períodos bimensais avaliados: média, máximo, mínimo e mediana. Para gerar as imagens (ImDATQuaR, a imagem agregada para o período imediatamente anterior foi subtraída da imagem agregada para o período em monitoramento. Essas imagens foram classificadas por meio de fatiamento e comparadas às classes de referência obtidas pela interpretação visual de pixels aleatorizados em imagens Landsat. Cada ImDATQuaR gerou dois mapas DATQuaR: um com filtragem de moda com janela 3x3 pixels e outro sem filtragem. O melhor mapa DATQuaR é produzido com uso de imagens EVI e filtragem - ao se subtrair a imagem de mínimo valor para o período anterior da imagem de máximo valor para o período monitorado - e atinge concordâncias com a referência superiores a 81%.

  16. Influencia de cuatro distancias de trasplante sobre el rendimiento agrícola del cultivar de arroz Amistad-82.

    Directory of Open Access Journals (Sweden)

    Alexander Calero Hurtado

    2012-04-01

    Full Text Available El trabajo consistió en comparar cuatro distancias de trasplante sobre el rendimiento agrícola del cultivar de arroz Amistad-82, durante la siembra de primavera de 2012, el trasplante se realizó de forma manual, sobre un suelo pardo sialítico carbonatado en la finca “La Rosita” perteneciente a la CCS “Heriberto Orellane”, en la provincia de Sancti Spíritus, se utilizó un diseño de bloques al azar, se tomaron posturas jóvenes de 18 días de germinadas, cuatro distancias de plantación 10x15, 15x15, 20x15 y 20x20 cm y una postura por sitio. Se evaluaron los indicadores productivos como el número de tallos, panículas por metro cuadrado, longitud de la panícula, granos por panículas, granos llenos y vanos por panículas, peso de 1000 granos, el rendimiento, así como las ganancias y los costos de producción. Los mejores resultados sobre el rendimiento agrícola del cultivar de arroz Amistad-82 lo alcanzaron las distancias de trasplante 10x15 y 20x15 cm, porque lograron rendimientos superiores a las distancias 15x15 y 20x20 cm, mayor cantidad de granos por panículas y mayores porcentajes de granos llenos por panículas y superaron también el peso en 1000 granos y las ganancias.

  17. Análisis conceptual del uso agrícola del suelo: Su incidencia en la sostenibilidad

    Directory of Open Access Journals (Sweden)

    Maldané Cuello Espinosa

    2013-05-01

    Full Text Available El tema del desarrollo sostenible ha sido muy discutido y analizado en las últimas décadas; no obstante, aún no se ha desarrollado satisfactoriamente; se inició en el año de 1987 con el informe Brundtland denominado Nuestro futuro común, de la Comisión Mundial para el Medio Ambiente. En el informe se puntualiza y se define concretamente al desarrollo sostenible como: “Satisfacer las necesidades del presente sin comprometer la capacidad de satisfacer las futuras generaciones”. En la actualidad, casi todas las personas coinciden con tan importante definición; sin embargo, no se ha plasmado a los niveles que se requiere para deshacer los trances que se exhiben en ese sentido a escala mundial, fruto de los ambiciosos intereses particulares.  El suelo es uno de los recursos que, en condiciones ambientalmente normales, bien puede llenar las expectativas de poder llevar a la praxis tan anhelada descripción, integrando con perspectiva de sistema agrícola los tres elementos claves que la componen: el elemento social, el económico y el ambiental.  El desarrollo de los sistemas agrícolas y sus aplicaciones e implicaciones en el proceso de la sostenibilidad, trae consigo cambios considerables en términos social, económico y ambiental, que, indudablemente, contribuye a tan anhelado proceso, en el sentido de poder lograr un cambio en el entorno común, alcanzando a armonizar la naturaleza, los beneficios económicos y las necesidades de la población.

  18. Funciones agua rendimiento para 14 cultivos agrícolas en condiciones del sur de La Habana

    Directory of Open Access Journals (Sweden)

    Felicita González Robaina

    2013-01-01

    Full Text Available El estudio de las funciones agua rendimiento y su uso dentro de la planificación del uso del agua es una vía importante para trazar estrategias de manejo que contribuyan al incremento en la producción agrícola. Utilizando los datos de consumo de agua, agua aplicada por riego, precipitaciones y los rendimientos obtenidos en más de 100 experimentos de campo realizados fundamentalmente en suelo Ferralítico Rojo de la zona sur de La Habana y con ayuda de herramientas de análisis de regresión en este trabajo se estiman las funciones rendimientos versus agua aplicada para 14 cultivos agrícolas. Respuestas de tipo lineal fueron encontradas para los cultivos de frijol, sorgo, ajo, cebolla, boniato, malanga y piña al relacionar el rendimiento con el agua aplicada por riego. Para los cultivos soya, pimiento, tomate, papa, plátano y banano esta relación se explica mejor a través de funciones cuadráticas. Para el caso particular del maíz, se propone la función por partes con un punto de ruptura alrededor de los 185 mm como mejor opción para explicar la respuesta al riego. Las funciones obtenidas pueden servir como herramientas para alcanzar los rendimientos potenciales de los cultivos estudiados y en la toma de decisiones cuando el recurso agua está limitado.

  19. Research reactor DHRUVA

    International Nuclear Information System (INIS)

    DHRUVA, a 100 MWt research reactor located at the Bhabha Atomic Research Centre, Bombay, attained first criticality during August, 1985. The reactor is fuelled with natural uranium and is cooled, moderated and reflected by heavy water. Maximum thermal neutron flux obtained in the reactor is 1.8 X 1014 n/cm2/sec. Some of the salient design features of the reactor are discussed in this paper. Some important features of the reactor coolant system, regulation and protection systems and experimental facilities are presented. A short account of the engineered safety features is provided. Some of the problems that were faced during commissioning and the initial phase of power operation are also dealt upon

  20. TRIGA research reactors

    International Nuclear Information System (INIS)

    TRIGA (Training, Research, Isotope production, General-Atomic) has become the most used research reactor in the world with 65 units operating in 24 countries. The original patent for TRIGA reactors was registered in 1958. The success of this reactor is due to its inherent level of safety that results from a prompt negative temperature coefficient. Most of the neutron moderation occurs in the nuclear fuel (UZrH) because of the presence of hydrogen atoms, so in case of an increase of fuel temperature, the neutron spectrum becomes harder and neutrons are less likely to fission uranium nuclei and as a consequence the power released decreases. This inherent level of safety has made this reactor fit for training tool in university laboratories. Some recent versions of TRIGA reactors have been designed for medicine and industrial isotope production, for neutron therapy of cancers and for providing a neutron source. (A.C.)

  1. Mirror reactor surface study

    International Nuclear Information System (INIS)

    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

  2. Iris reactor conceptual design

    Energy Technology Data Exchange (ETDEWEB)

    Carelli, M.D.; Conway, L.E.; Petrovic, B.; Paramonov, D.V. [Westinghouse Electric Comp., Pittsburgh, PA (United States); Galvin, M.; Todreas, N.E. [Massachusetts Inst. of Tech., Cambridge, MA (United States); Lombardi, C.V.; Maldari, F.; Ricotti, M.E. [Politecnico di Milano, Milan (Italy); Cinotti, L. [Ansaldo SpA, Genoa (Italy)

    2001-07-01

    IRIS (International Reactor Innovative and Secure) is a modular, integral, light water cooled, low-to-medium power (100-350 MWe) reactor which addresses the requirements defined by the US DOE for Generation IV reactors, i.e., proliferation resistance, enhanced safety, improved economics and fuel cycle sustainability. It relies on the proven technology of light water reactors and features innovative engineering, but it does not require new technology development. This paper discusses the current reference IRIS design, which features a 1000 MWt thermal core with proven 5%-enriched uranium oxide fuel and five-year long straight burn fuel cycle, integral reactor vessel housing helical tube steam generators and immersed spool pumps. Other major contributors to the high level of safety and economic attractiveness are the safety by design and optimized maintenance approaches, which allow elimination of some classes of accidents, lower capital cost, long operating cycle, and high capacity factors. (author)

  3. 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.

  4. Compact torsatron reactors

    International Nuclear Information System (INIS)

    Low-aspect-ratio torsatron configurations could lead to compact stellarator reactors with R0 = 8--11m, roughly one-half to one-third the size of more conventional stellarator reactor designs. Minimum-size torsatron reactors are found using various assumptions. Their size is relatively insensitive to the choice of the conductor parameters and depends mostly on geometrical constraints. The smallest size is obtained by eliminating the tritium breeding blanket under the helical winding on the inboard side and by reducing the radial depth of the superconducting coil. Engineering design issues and reactor performance are examined for three examples to illustrate the feasibility of this approach for compact reactors and for a medium-size (R0 ≅ 4 m,/bar a/ /approx lt/ 1 m) copper-coil ignition experiment. 26 refs., 11 figs., 7 tabs

  5. 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.

  6. The calculation of methane profiles in AGR graphite structures. Part I: cylindrical geometry

    International Nuclear Information System (INIS)

    A mathematical model has been developed to simulate the diffusion, permeable flow and radiolytic destruction of methane in graphite specimens utilised in the Advanced Gas Cooled Reactor development programme. The integration of the diffusion equations governing the rate of mass transport is carried out by the Harwell FACSIMILE program and in its simple form the model has shown good agreement with analytical solutions. The model has been extended to take into account the changes in water and carbon monoxide concentrations resulting from radiolytic reactions within the system and the magnitude of these effects has been assessed. A simple method for the introduction of the effect of water production arising directly from the methane destruction process has been derived and a technique for calculating the gas-in-gas diffusion coefficients for the migrating species from the molecular theory of gases is outlined. (author)

  7. Fatigue crack growth and endurance data on 9% Cr 1% Mo steels for AGR applications

    International Nuclear Information System (INIS)

    Experimental investigations have been carried out on 9%Cr 1%Mo steels to examine: (1) The significance of carburisation on the fatigue endurance of plain and welded boiler tubes, and tube spacer strip; (2) the high cycle fatigue endurance of spacer strip and spacer weld metal; (3) fatigue crack growth rates in spacer strip and spacer weld metal. This report summarises the results of these investigations and where necessary compares the data to that in current data sheets. The effects of carburisation are variable depending on the structure and type of carburisation. The fatigue endurance properties of spacer strip and spacer weld metal are also similar and need not be considered separately for assessment or design purposes. Fatigue crack growth rates in spacer strip and space weld metal are similar and are influenced by both stress ratio and temperature. A design curve from a fast reactor data sheet may be used as an upper bound to these fatigue crack growth results. (author)

  8. Reactor Engineering Division annual report

    International Nuclear Information System (INIS)

    Research activities in the Division of Reactor Engineering in fiscal 1977 are described. Works of the Division are development of multi-purpose Very High Temperature Gas Cooled Reactor, fusion reactor engineering, and development of Liquid Metal Fast Breeder Reactor for Power Reactor and Nuclear Fuel Development Corporation. Contents of the report are nuclear data and group constants, theoretical method and code development, integral experiment and analysis, shielding, heat transfer and fluid dynamics, reactor and nuclear instrumentation, dynamics analysis and control method development, fusion reactor technology, and Committee on Reactor Physics. (Author)

  9. Reactor Engineering Department annual report

    International Nuclear Information System (INIS)

    Research and development activities in the Department of Reactor Engineering in fiscal 1983 are described. The work of the Department is closely related to development of multipurpose Very High Temperature Gas Cooled Reactor and Fusion Reactor, and development of Liquid Metal Fast Breeder Reactor carried out by Power Reactor and Nuclear Fuel Development Corporation. Contents of the report are achievements in fields such as nuclear data and group constants, theoretical method and code development, integral experiment and analysis, fusion neutronics, shielding, reactor and nuclear instrumentation, reactor control and diagnosis, and safeguards technology, and activities of the Committee on Reactor Physics. (author)

  10. Reactor Engineering Division annual report

    International Nuclear Information System (INIS)

    Research activities conducted in Reactor Engineering Division in fiscal 1975 are summarized in this report. Works in the division are closely related to the development of multi-purpose High-temperature Gas Cooled Reactor, the development of Liquid Metal Fast Breeder Reactor by Power Reactor and Nuclear Fuel Development Corporation, and engineering research of thermonuclear fusion reactor. Many achievements are described concerning nuclear data and group constants, theoretical method and code development, integral experiment and analysis, shielding, heat transfer and fluid dynamics, reactor and nuclear instrumentation, dynamics analysis and control method development, fusion reactor technology and activities of the Committee on Reactor Physics. (auth.)

  11. Reactor performance calculations for water reactors

    International Nuclear Information System (INIS)

    The principles of nuclear, thermal and hydraulic performance calculations for water cooled reactors are discussed. The principles are illustrated by describing their implementation in the UKAEA PATRIARCH scheme of computer codes. This material was originally delivered as a course of lectures at the Technical University of Helsinki in Summer of 1969.

  12. Simulación fluido-térmica de un reactor de gasificación de lecho fijo descendente

    OpenAIRE

    Felisart Serlavóss, Bernat

    2013-01-01

    El proyecto consta de un estudio preliminar de las tecnologías de gasificación existentes y un posterior análisis de los procesos de gasificación en los reactores de lecho fijo con flujo descendente a equicorriente (downdraft) como son la pirolisis, oxidación del combustible y reducción de los gases creados. Se estudian las fuentes renovables posibles como combustible para su uso en la gasificación, se centra en los residuos agrícolas provenientes del maíz como son su coronta y sus cañas, ...

  13. Safety of research reactors

    International Nuclear Information System (INIS)

    The number of research reactors that have been constructed worldwide for civilian applications is about 651. Of the reactors constructed, 284 are currently in operation, 258 are shut down and 109 have been decommissioned. More than half of all operating research reactors worldwide are over thirty years old. During this long period of time national priorities have changed. Facility ageing, if not properly managed, has a natural degrading effect. Many research reactors face concerns with the obsolescence of equipment, lack of experimental programmes, lack of funding for operation and maintenance and loss of expertise through ageing and retirement of the staff. Other reactors of the same vintage maintain effective ageing management programmes, conduct active research programmes, develop and retain high calibre personnel and make important contributions to society. Many countries that operate research reactors neither operate nor plan to operate power reactors. In most of these countries there is a tendency not to create a formal regulatory body. A safety committee, not always independent of the operating organization, may be responsible for regulatory oversight. Even in countries with nuclear power plants, a regulatory regime differing from the one used for the power plants may exist. Concern is therefore focused on one tail of a continuous spectrum of operational performance. The IAEA has been sending missions to review the safety of research reactors in Member States since 1972. Some of the reviews have been conducted pursuant to the IAEA' functions and responsibilities regarding research reactors that are operated within the framework of Project and Supply Agreements between Member States and the IAEA. Other reviews have been conducted upon request. All these reviews are conducted following procedures for Integrated Safety Assessment of Research Reactors (INSARR) missions. The prime objective of these missions has been to conduct a comprehensive operational safety

  14. Modelagem matemática para seleção de conjuntos mecanizados agrícolas pelo menor custo operacional Mathematical modeling to select mechanized agricultural systems by the lowest operational cost

    OpenAIRE

    Fábio H.R. Baio; Andrew D. Rodrigues; Gilson S. dos Santos; Simone P. da Silva

    2013-01-01

    A seleção de uma máquina agrícola pode tornar-se uma tarefa árdua, pois há diversas variáveis que devem ser consideradas. A escolha do equipamento mais adequado para uma propriedade agrícola é uma das etapas mais importantes do processo produtivo. O objetivo deste trabalho foi desenvolver um modelo de computador por programação linear em plataforma web para seleção automatizada de conjuntos mecanizados agrícolas, baseados no menor custo operacional. O programa, desenvolvido em linguagem ASP.N...

  15. Reactor Engineering Department annual report

    International Nuclear Information System (INIS)

    This report summarizes the research and development activities in the Department of Reactor Engineering during the fiscal year of 1992 (April 1, 1992-March 31, 1993). The major Department's programs promoted in the year are the assessment of the high conversion light water reactor, the design activities of advanced reactor system and development of a high energy proton linear accelerator for the engineering applications including TRU incineration. Other major tasks of the Department are various basic researches on the nuclear data and group constants, the developments of theoretical methods and codes, the reactor physics experiments and their analyses, fusion neutronics, radiation shielding, reactor instrumentation, reactor control/diagnosis, thermohydraulics and technology developments related to the reactor physics facilities. The cooperative works to JAERI's major projects such as the high temperature gas cooled reactor or the fusion reactor and to PNC's fast reactor project were also progressed. The activities of the Research Committee on Reactor Physics are also summarized. (author)

  16. Reactor engineering department annual report

    International Nuclear Information System (INIS)

    This report summarizes the research and development activities in the Department of Reactor Engineering during the fiscal year of 1989 (April 1, 1989 - March 31, 1990). One of major Department's programs is the assessment of the high conversion light water reactor and the design activities of advanced reactor system. Development of a high energy proton linear accelerator for the nuclear engineering including is also TRU incineration promoted. Other major tasks of the Department are various basic researches on nuclear data and group constants, theoretical methods and code development, on reactor physics experiments and analyses, fusion neutronics, radiation shielding, reactor instrumentation, reactor control/diagnosis, thermohydraulics, technology assessment of nuclear energy and technology developments related to the reactor physics facilities. The cooperative works to JAERI's major projects such as the high temperature gas cooled reactor or the fusion reactor and to PNC's fast reactor project also progressed. The activities of the Research Committee on Reactor Physics are also summarized. (author)

  17. Geografia da riqueza, fome e meio ambiente: pequena contribuição crítica ao atual modelo agrário/agrícola de uso dos recursos naturais

    Wealth geography, environment and hunger: small critic contribution to the current agrarian/agricultural model of the natural resources usage

    OpenAIRE

    Carlos Walter Porto Gonçalves

    2004-01-01

    PortuguesO texto discute a questão geopolítica implicada no debate sobre a fome e o meio ambiente. Critica o atual modelo agrário/agrícola de uso dos recursos naturais, afirma ser este um modelo de desenvolvimento econômico das regiões temperadas que tem sido imposto com um alto custo ecológico, cultural e político para o mundo todo. Este modelo tem se colocado em confronto com o conhecimento patrimonial, coletivo e comunitário característico de populações com racionalidades distintas da raci...

  18. 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.

  19. Test reactor technology

    International Nuclear Information System (INIS)

    The Reactor Development Program created a need for engineering testing of fuels and materials. The Engineering Test Reactors were developed around the world in response to this demand. The design of the test reactors proved to be different from that of power reactors, carrying the fuel elements closer to the threshold of failure, requiring more responsive instrumentation, more rapid control element action, and inherent self-limiting behavior under accident conditions. The design of the experimental facilities to exploit these reactors evolved a new, specialized, branch of engineering, requiring a very high-lvel scientific and engineering team, established a meticulous concern with reliability, the provision for recovery from their own failures, and detailed attention to possible interactions with the test reactors. This paper presents this technology commencing with the Materials Testing Reactor (MTR) through the Fast Flux Test Facility, some of the unique experimental facilities developed to exploit them, but discusses only cursorily the experiments performed, since sample preparation and sample analyses were, and to some extent still are, either classified or proprietary. The Nuclear Engineering literature is filled with this information

  20. Necesidades educacionales sobre riesgo de plaguicidas en el contexto socio-ambiental de las comunidades agrícolas de Sonora

    Directory of Open Access Journals (Sweden)

    M.I. Silveira Gramont

    2016-01-01

    Full Text Available Para proponer estrategias de educación y comunicación sobre plaguicidas en las comunidades agrícolas de Sonora, se requiere situar la problemática de la exposición a plaguicidas en el contexto socio-cultural y ambiental de las comunidades afectadas, tomando en cuenta los factores que contribuyen al mayor riesgo de exposición de los trabajadores agrícolas y de sus familias. Este estudio examina los factores poblacionales, educacionales, culturales y de trabajo de habitantes y trabajadores agrícolas de dichas comunidades, así como las limitaciones de infraestructura comunitaria y de condiciones de vivienda en relación al riesgo de contaminación por plaguicidas. Sobre la base de este análisis se proponen posibles alternativas educacionales orientadas a mitigar tal riesgo en el contexto socio-cultural de dichas comunidades. Método De los estudios reportados sobre la presencia de residuos de plaguicidas en productos agrícolas y acuícolas, en suelos, agua, medio ambiente y en líquidos corporales de niños y adultos de Sonora, se puede concluir que tanto los trabajadores agrícolas como la población que reside cerca de las zonas agrícolas, están sujetos a un mayor riesgo de contaminación por plaguicidas. Para la realización del presente estudio se seleccionaron cinco comunidades localizadas en los valles agrícolas más productivos de Sonora, en las cuales se han llevado a cabo investigaciones relacionadas con plaguicidas. Básicamente, se analizó la información obtenida de encuestas aplicadas a residentes y trabajadores agrícolas de dichas comunidades, para explorar su conocimiento sobre uso y manejo de plaguicidas, percepción del riesgo que tales sustancias representan y las prácticas de protección personal que llevan a cabo para la prevención de dichos riesgos (en el hogar y trabajo. También se describe la infraestructura de los poblados y las viviendas de sus habitantes en relación al potencial de riesgo de contaminaci

  1. Fast Breeder Reactor studies

    International Nuclear Information System (INIS)

    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. 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.

  3. Licensed operating reactors

    International Nuclear Information System (INIS)

    The Operating Units Status Report --- Licensed Operating Reactors provides data on the operation of nuclear units as timely and accurately as possible. This information is collected by the Office of Information Resources Management from the Headquarters staff on NRC's Office of Enforcement (OE), from NRC's Regional Offices, and from utilities. The three sections of the report are: monthly highlights and statistics for commercial operating units, and errata from previously reported data; a compilation of detailed information on each unit, provided by NRC's Regional Offices, OE Headquarters and the utilities; and an appendix for miscellaneous information such as spent fuel storage capability, reactor-years of experience and non- power reactors in the US

  4. nuclear reactor design calculations

    International Nuclear Information System (INIS)

    In this work , the sensitivity of different reactor calculation methods, and the effect of different assumptions and/or approximation are evaluated . A new concept named error map is developed to determine the relative importance of different factors affecting the accuracy of calculations. To achieve this goal a generalized, multigroup, multi dimension code UAR-DEPLETION is developed to calculate the spatial distribution of neutron flux, effective multiplication factor and the spatial composition of a reactor core for a period of time and for specified reactor operating conditions. The code also investigates the fuel management strategies and policies for the entire fuel cycle to meet the constraints of material and operating limitations

  5. Course on reactor physics

    International Nuclear Information System (INIS)

    In Germany only few students graduate in nuclear technology, therefore the NPP operating companies are forced to develop their own education and training concepts. AREVA NP has started together with the Technical University of Dresden a one-week course ''reactor physics'' that includes the know-how of the nuclear power plant construction company. The Technical University of Dresden has the training reactor AKR-2 that is retrofitted by modern digital instrumentation and control technology that allows the practical training of reactor control.

  6. PWR type reactor

    International Nuclear Information System (INIS)

    From a PWR with a primary circuit, consisting of a reactor pressure vessel, a steam generator and a reactor coolant pump, hot coolant is removed by means of an auxiliary system containing h.p. pumps for feeding water into the primary circuit and being connected with a pipe, originating at the upper part, which has got at least one isolating value. This is done by opening an outlet in a part of the auxiliary system that has got a lower pressure than the reactor vessel. Preferably a water jet pump is used for mixing with the water of the auxiliary system. (orig.)

  7. Microfluidic electrochemical reactors

    Science.gov (United States)

    Nuzzo, Ralph G.; Mitrovski, Svetlana M.

    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.

  8. Histórico e os limites da reforma agrária na contemporaneidade brasileira History and limits of the agrarian reform in the Brazilian contemporary time

    Directory of Open Access Journals (Sweden)

    Paulo Nakatani

    2012-06-01

    Full Text Available Objetiva-se reconstituir a trajetória da questão fundiária (e agrária na experiência de maior concentração de riqueza e recursos vivenciada no âmbito do sistema capitalista, partindo-se da premissa de que a crescente desigualdade do modelo brasileiro passa necessariamente pela questão agrária. Num segundo momento, procede-se à análise dos limites atualmente colocados a qualquer possibilidade de uma Reforma Agrária ampla e estrutural, dados pelo avanço do agronegócio nos últimos dez anos, pela desmobilização política de parcela significativa da sociedade no que se refere a esta questão e pelos próprios limites estruturais da economia brasileira nos quadros da globalização financeira. O texto será dividido em seis sessões: a colonização e origens do latifúndio; b O modelo agroexportador e a ruptura incompleta; c a questão agrária e a industrialização brasileira; d a questão agrária e o agronegócio; e os limites da reforma agrária na contemporaneidade; f considerações finais.This paper aims at reconstructing the history of the land (agrarian issue considering the greatest concentration of wealth and resources in the capitalist system. The standpoint is that the growing inequality of the Brazilian model is related to the agrarian issue. Secondly, we analyze the limits ­currently placed on any possibility of a comprehensive and structural agrarian reform, due to the advancement of the agribusiness over the last ten years, the political demobilization of a significant portion of society that put this issue aside, and the limits of the Brazilian economy in the context of the financial globalization. The paper is divided into six parts: a colonization and origins of the large landed estates; b the agro-export model and the incomplete rupture; c the agrarian issue and the Brazilian industrialization; d the agrarian issue and the agribusiness; e the limits of the agrarian reform in the contemporary time; f final

  9. Reactor BR2. Introduction

    International Nuclear Information System (INIS)

    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

  10. NEUTRONIC REACTOR FUEL COMPOSITION

    Science.gov (United States)

    Thurber, W.C.

    1961-01-10

    Uranium-aluminum alloys in which boron is homogeneously dispersed by adding it as a nickel boride are described. These compositions have particular utility as fuels for neutronic reactors, boron being present as a burnable poison.

  11. Pulsed fusion reactors

    International Nuclear Information System (INIS)

    This summer school specialized in examining specific fusion center systems. Papers on scientific feasibility are first presented: confinement of high-beta plasma, liners, plasma focus, compression and heating and the use of high power electron beams for thermonuclear reactors. As for technological feasibility, lectures were on the theta-pinch toroidal reactors, toroidal diffuse pinch, electrical engineering problems in pulsed magnetically confined reactors, neutral gas layer for heat removal, the conceptual design of a series of laser fusion power plants with ''Saturn'', implosion experiments and the problem of the targets, the high brightness lasers for plasma generation, and topping and bottoming cycles. Some problems common to pulsed reactors were examined: energy storage and transfer, thermomechanical and erosion effects in the first wall and blanket, the problems of tritium production, radiation damage and neutron activation in blankets, and the magnetic and inertial confinement

  12. Reactor BR2. Introduction

    Energy Technology Data Exchange (ETDEWEB)

    Gubel, P

    2002-04-01

    The BR2 materials testing reactor is one of SCK-CEN's most important nuclear facilities. After an extensive refurbishment to compensate for the ageing of the installation, the reactor was restarted in April 1997. In 2001, the reactor was operated for a total of 123 days at a mean power of 59 MW in order to satisfy the irradiation conditions of the internal and external programmes using mainly the CALLISTO PWR loop. The mean consumption of fresh fuel elements was 5.26 per 1000 MWd. Main achievements in 2001 included the development of a three-dimensional full-scale model of the BR2 reactor for simulation and prediction of irradiation conditions for various experiments; the construction of the FUTURE-MT device designed for the irradiation of fuel plates under representative conditions of geometry, neutron spectrum, heat flux and thermal-hydraulic conditions and the development of in-pile instrumentation and a data acquisition system.

  13. 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.

  14. 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.

  15. Experience with Kamini reactor

    International Nuclear Information System (INIS)

    Kamini is a 233U fuelled, 30 kW(th) research reactor. It is one of the best neutron source facility with a core average flux of 1012 n/cm2/s in IGCAR used for neutron radiography of active and nonradioactive objects, activation analysis and radiation physics research. The core consists of nine plate type fuel elements with a total fuel inventory of 590 g of 233U. Two safety control plates made of cadmium are used for start up and shutdown of the reactor. Three beam tubes, two-thimble irradiation site outside reflector and one irradiation site nearer to the core constitute the testing facilities of Kamini. Kamini attained first criticality on 29th October 96 and nominal power of 30 kW in September 1997. This paper covers the design features of the reactor, irradiation facilities and their utilities and operating experience of the reactor. (author)

  16. Reactor pressure boundary materials

    International Nuclear Information System (INIS)

    With a long-term operation of nuclear power plants, the component materials are degraded under severe reactor conditions such as neutron irradiation, high temperature, high pressure and corrosive environment. It is necessary to establish the reliable and practical technologies for improving and developing the component materials and for evaluating the mechanical properties. Especially, it is very important to investigate the technologies for reactor pressure boundary materials such as reactor vessel and pipings in accordance with their critical roles. Therefore, this study was focused on developing and advancing the microstructural/micro-mechanical evaluation technologies, and on evaluating the neutron irradiation characteristics and radiation effects analysis technology of the reactor pressure boundary materials, and also on establishing a basis of nuclear material property database

  17. 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.

  18. 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).

  19. Special lecture on nuclear reactor

    International Nuclear Information System (INIS)

    This book gives a special lecture on nuclear reactor, which is divided into two parts. The first part has explanation on nuclear design of nuclear reactor and analysis of core with theories of integral transports, diffusion Nodal, transports Nodal and Monte Carlo skill parallel computer and nuclear calculation and speciality of transmutation reactor. The second part deals with speciality of nuclear reactor and control with nonlinear stabilization of nuclear reactor, nonlinear control of nuclear reactor, neural network and control of nuclear reactor, control theory of observer and analysis method of Adomian.

  20. Jet-Stirred Reactors

    OpenAIRE

    Herbinet, Olivier; Guillaume, Dayma

    2013-01-01

    The jet-stirred reactor is a type of ideal continuously stirred-tank reactor which is well suited for gas phase kinetic studies. It is mainly used to study the oxidation and the pyrolysis of hydrocarbon and oxygenated fuels. These studies consist in recording the evolution of the conversion of the reactants and of the mole fractions of reaction products as a function of different parameters such as reaction temperature, residence time, pressure and composition of the inlet gas. Gas chromatogr...

  1. Generation IV reactors: economics

    International Nuclear Information System (INIS)

    The operating nuclear reactors were built over a short period: no more than 10 years and today their average age rounds 18 years. EDF (French electricity company) plans to renew its reactor park over a far longer period : 30 years from 2020 to 2050. According to EDF this objective implies 3 constraints: 1) a service life of 50 to 60 years for a significant part of the present operating reactors, 2) to be ready to built a generation 3+ unit in 2020 which infers the third constraint: 3) to launch the construction of an EPR (European pressurized reactor) prototype as soon as possible in order to have it operating in 2010. In this scheme, generation 4 reactor will benefit the feedback experience of generation 3 and will take over in 2030. Economic analysis is an important tool that has been used by the generation 4 international forum to select the likely future reactor systems. This analysis is based on 4 independent criteria: the basic construction cost, the construction time, the operation and maintenance costs and the fuel cycle cost. This analysis leads to the evaluation of the global cost of electricity generation and of the total investment required for each of the reactor system. The former defines the economic competitiveness in a de-regulated energy market while the latter is linked to the financial risk taken by the investor. It appears, within the limits of the assumptions and models used, that generation 4 reactors will be characterized by a better competitiveness and an equivalent financial risk when compared with the previous generation. (A.C.)

  2. OECD Halden reactor project

    International Nuclear Information System (INIS)

    This report summarizes the activities of the OECD Halden Reactor Project for the year 1976. The main items reported on are: a) the process supervision and control which have focused on core monitoring and control, and operator-process communication; b) the fuel performance and safety behavior which have provided data and analytical descriptions of the thermal, mechanical and chemical behavior of fuel under various operating conditions; c) the reactor operations and d) the administration and finance

  3. Nuclear reactor fuel elements

    International Nuclear Information System (INIS)

    A nuclear reactor fuel element comprising a column of vibration compacted fuel which is retained in consolidated condition by a thimble shaped plug. The plug is wedged into gripping engagement with the wall of the sheath by a wedge. The wedge material has a lower coefficient of expansion than the sheath material so that at reactor operating temperature the retainer can relax sufficient to accommodate thermal expansion of the column of fuel. (author)

  4. 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....

  5. 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.

  6. BWR type nuclear reactor

    International Nuclear Information System (INIS)

    Purpose: To simplify the structure of an emergency core cooling system while suppressing the flow out of coolants upon rapture accidents in a coolant recycling device of BWR type reactors. Constitution: Recirculation pumps are located at a position higher than the reactor core in a pressure vessel, and the lower plenum is bisected vertically by a partition plate. Further, a gas-liquid separator is surrounded with a wall and the water level at the outer side of the wall is made higher than the water level in the inside of the wall. In this structure, coolants are introduced from the upper chamber in the lower plenum into the reactor core, and the steams generated in the reactor core are separated in the gas-liquid separator, whereby the separated liquid is introduced as coolants by way of the inner chamber into the lower chamber of the lower plenum and further sent by way of the outer chamber into the reactor core. Consequently, idle rotation of the recycling pumps due to the flow-in of saturated water is prevented and loss of coolants in the reactor core can also be prevented upon raptures in the pipeway and the driving section of the pump connected to the pressure vessel and in the bottom of the pressure vessel. (Horiuchi, T.)

  7. OECD Halden reactor project

    International Nuclear Information System (INIS)

    This is the nineteenth annual Report on the OECD Halden Reactor Project, describing activities at the Project during 1978, the last year of the 1976-1978 Halden Agreement. Work continued in two main fields: test fuel irradiation and fuel research, and computer-based process supervision and control. Project research on water reactor fuel focusses on various aspects of fuel behavior under normal, and off-normal transient conditions. In 1978, participating organisations continued to submit test fuel for irradiation in the Halden boiling heavy-water reactor, in instrumented test assemblies designed and manufactured by the Project. Work included analysis of the impact of fuel design and reactor operating conditions on fuel cladding behavior. Fuel performance modelling included characterization of thermal and mechanical behavior at high burn-up, of fuel failure modes, and improvement of data qualification procedures to reduce and quantify error bands on in-reactor measurements. Instrument development yielded new or improved designs for measuring rod temperature, internal pressure, axial neutron flux shape determination, and for detecting cladding defects. Work on computer-based methods of reactor supervision and control included continued development of a system for predictive core surveillance, and of special mathematical methods for core power distribution control

  8. The discovery by Gh. Benga of the first water channel protein in 1985 in Cluj-Napoca, Romania, A few years before P. Agre (2003 Nobel Prize in Chemistry).

    Science.gov (United States)

    Cucuianu, M

    2006-01-01

    The first water channel protein, now called aquaporin 1, was identified or "seen" in situ in the human red blood cell membrane by Benga's group in 1985. It was again "seen" when it was by chance purified by Agre'group in 1988 and was again identified when its main feature, the water transport property, was found by Agre's group in 1992. Consequently, the omission of Gh. Benga from the 2003 Nobel Prize in Chemistry (half of which was awarded to P. Agre "for the discovery of the water channels") is a new mistake in the award of Nobel Prizes. The growing recognition of the priority of Gh. Benga over P. Agre in the discovery of water channels is documented in this paper.

  9. PRAPRAG: software para planejamento racional de máquinas agrícolas PRAPRAG: software for rational planning of agricultural machines

    OpenAIRE

    Erivelto Mercante; Eduardo G. de Souza; Jerry A. Johann; Antonio Gabriel Filho; Miguel A. Uribe-Opazo

    2010-01-01

    O software PRAPRAG é uma ferramenta de escolha de máquinas e implementos agrícolas que apresentam o menor custo por área ou por quantidade produzida, bem como, faz o planejamento de aquisição das máquinas para a propriedade agrícola, do ponto de vista técnico e econômico. Foi utilizada a linguagem de programação Borland Delphi 3.0 e, a partir de prospectos das máquinas e implementos, criou-se um banco de dados onde o usuário pode cadastrar e modificar suas características de uso. O software m...

  10. Zonificación del Municipio Gibara, útil de trabajo para el comienzo de las actividades extensión agrícola.

    OpenAIRE

    Raciel Ojeda Fernández; Severo Aranda Aranda; Daimarelis Rodríguez Leyva

    2003-01-01

    Se expone la zonificación del municipio Gibara fundamentado en un análisis sistémico del medio donde se desarrolla la producción agropecuaria. Para conseguir este resultado se comenzó con la búsqueda de informaciones del medio físico, socioeconómico y agrícola del municipio. Posteriormente se confeccionaron mapas de hidrología, suelos, temperatura, vías de comunicación terrestres, pluviometría y prácticas agrícolas; a continuación se analizó la información contenida en cada mapa superponiéndo...

  11. Assentamentos rurais na Amazônia: contradições entre a política agrária e a política ambiental

    OpenAIRE

    François-Michel Le Tourneau; Marcel Bursztyn

    2010-01-01

    A ação do INCRA na Amazônia revela um paradoxo: por mais que a ocupação humana daquela região fosse uma estratégia dos governos militares, é na fase democrática recente que a reforma agrária brasileira intensifica a instalação de agricultores em assentamentos. A institucionalização de políticas de proteção do meio ambiente se revela contraditória com as práticas de proteção social que têm, na Amazônia, um foco de destaque num modelo de reforma agrária que provoca inevitáveis consequências amb...

  12. O Comportamento do Preço da Terra Agrícola: um modelo de painel de dados espaciais

    Directory of Open Access Journals (Sweden)

    Regina Lúcia Sanches Malassise

    2015-12-01

    Full Text Available Resumo: O presente artigo analisou o comportamento do preço da terra agrícola nos municípios do Paraná no período de 1999-2011. Partindo da revisão bibliográfica dos principais estudos nacionais sobre o tema, foi possível identificar os determinantes do preço da terra e os métodos utilizados. Neste sentido, optou­-se por estimar um modelo para o preço da terra via painel de dados espaciais. As estimativas indicaram que o valor bruto da produção agropecuária, a valorização patrimonial, o financiamento total à agropecuária, a relação investimento-receita municipal, o percentual da área plantada do município com soja e a incorporação da dependência espacial do preço da terra são variáveis que explicam o preço da terra no estado do Paraná. Estas explicariam 84% dos preços e indicaram que há maior ajuste intrapainel, sendo os efeitos espaciais mais intensos no próprio município e em relação ao todo. Em especial, o modelo proposto avançou em termos estruturais, com a incorporação de variáveis coletadas para todos os 399 municípios do Paraná, e em termos metodológicos, ao estimar via painéis de dados a influência dos efeitos de espacialidade sobre o preço da terra agrícola, destacando a importância da localização e da vizinhança na determinação de tal preço.

  13. Tratamiento térmico con láser de cuchillas de acero para uso agrícola

    Directory of Open Access Journals (Sweden)

    Muñiz, G.

    2003-12-01

    Full Text Available The present paper focuses on the laser surface treatment of mild steels with different %wt of carbon to be used as cutting blades in agricultural applications. The results are discussed in function of the metallographic study, hardness profiles, wear resistance and corrosion testing. Special attention is paid to the results of the results obtained with the experimental steel with carbon 0.33 %wt because it is a new promising material specifically developed to be applied in such agricultural uses. Metallographic studies showed three well defined regions: the laser treated zone, where solid state phase transformation occurs, the heat affected zone (HAZ with partial transformations and finally the bulk metal with the original microstructure. Surface hardness was in all cases higher than the base steel in a depth range 600 μm. Wear resistance is notably improved with laser heat treatment while no detrimental effects were induced in their specific corrosion resistance.

    En el presente trabajo se muestran los resultados obtenidos en el temple superficial mediante láser, sobre aceros con distintos contenidos en carbono susceptibles de empleo en la producción de cuchillas de corte para aplicaciones agrícolas. Se comparan los resultados de los distintos aceros en función de su estudio metalográfico, perfiles de dureza y ensayos de resistencia al desgaste y a la corrosión. Destacan los resultados obtenidos con el acero de 0,33 % de carbono, por tratarse de un acero experimental de producción reciente para su empleo en cuchillas de uso agrícola. Tras el estudio metalográfico, se aprecia, en la capa superficial del metal tratado, la existencia de tres zonas bien definidas: la zona tratada en la que ocurren las transformaciones de fase típicas del temple, una zona de transición, que podemos considerar como la zona afectada térmicamente (ZAT, con transformaciones parciales y, por último, el metal base con su microestructura de origen. Las

  14. Transmissões presentes em tratores agrícolas no Brasil Transmissions present in agricultural tractors in Brazil

    Directory of Open Access Journals (Sweden)

    Rodrigo Lampert Ribas

    2010-10-01

    Full Text Available O sistema de transmissão de um trator agrícola tem por principal finalidade transmitir a potência gerada no motor ao sistema hidráulico, à tomada de potência e às rodas motrizes. A caixa de câmbio é formada por uma série de engrenagens que permitem a correta seleção da velocidade e do torque mais adequados a uma determinada operação. Assim, as transmissões podem ser classificadas, basicamente, em três categorias: mecânicas, hidrostáticas e hidrodinâmicas, sendo as transmissões mecânicas subdivididas em engrenagens deslizantes e sincronizadas. Este trabalho objetivou analisar os diferentes tipos de transmissões disponibilizados em 169 modelos de tratores fabricados no Brasil, com a finalidade de avaliar a real distribuição nas diferentes faixas de potência e estabelecer possíveis relações entre esses parâmetros. Como resultado, evidencia-se uma forte tendência de tratores agrícolas com potência menor que 111,8kW possuírem transmissão do tipo mecânica, e tratores acima de 111,8kW, do tipo hidrostática.The transmission system of an agricultural tractor has a main purpose to transmit the power generated in the hydraulic motor, the power take off and the drive wheels. The gearshift consists of a series of gears that allows the correct selection of speed and torque more appropriate to a particular operation. Then, the transmissions can be classified, basically, in three categories: mechanical, hydrostatic and hydrodynamic, being the mechanical transmissions subdivided in sliding gear and synchronized. Then, the objective of this research was to analyze the different types of transmissions available in 169 models of tractors made in Brazil in order to evaluate the real distribution of them in different power ranges and establish possible correlations. As a result, it was shown a strong tendency for agricultural tractors with power less than 111.8kW possessing mechanical transmission and tractors above 111.8k

  15. Economía de Producción Agrícola en Colombia: Capitulo 1. Regiones Geográficas y Agrícolas de Colombia

    Directory of Open Access Journals (Sweden)

    Beltrán G. Gregorio

    1953-09-01

    y en su parte sur vuelve a ser plana. La cría del ganado parece ser la ocupación principal; se concentra en los alrededores de Villavicencio. Se han hecho varios intentos espontáneos para colonizar parte de esta región pero sin resultados definitivos. Al tratar sobre la agricultura de un país se hace necesario tomar en cuenta la distribución de sus recursos humanos. La población de Colombia es de unos 10 habitantes por kilometro cuadrado, pero esta cifra global no da ni siquiera una idea aproximada de cómo está poblado el país, ya que más del 98 por ciento de su población vive en el tercio occidental de la nación aun dentro de esta zona la fluctuación por departamentos es bastante grande. Por otro lado están las zonas agrícolas pues hemos visto distintas clasificaciones del país en zonas fitogeográficas y de elevación. Sin embargo éstas no tienen un valor económico inmediato. Dentro de ellas existen regiones más pequeñas pero más homogéneas en cuanto al clima, régimen de lluvias, suelos y organización que se especializan en la producción de uno o más agrícolas. Estas regiones deberán servir en el futuro como núcleo de los estudios de economía de producción agrícola, por tener todas ellas sistemas de agricultura más o menos conocidos pero cuya verdadera organización económica se desconoce. Como en el país no se han hecho todavía estudios serios de geografía económica y las publicaciones de la Contraloría General de la República en este campo se han limitado a una recopilación de los pocos datos estadísticos que se disponen los departamentos, se dan las siguientes descripciones de las zonas agrícolas para que se tenga una idea aproximada de sus principales características.

  16. Metodologia para estimar o número de dias trabalháveis com máquinas agrícolas

    Directory of Open Access Journals (Sweden)

    Javier Solis Estrada

    2015-08-01

    Full Text Available No atual modelo de agricultura, é indispensável que o produtor conheça a real disponibilidade de tempo para a execução das operações agrícolas ao longo do ciclo das culturas. Este é o primeiro passo para se planejar e se obter maior eficiência na execução dessas operações, que estão sujeitas às variações do clima. As variáveis meteorológicas de uma determinada região influenciam diretamente no número de dias disponíveis para trabalhar com máquinas agrícolas. O objetivo deste trabalho foi estimar as probabilidades de ocorrência de dias favoráveis para o trabalho mecanizado, utilizando-se informações meteorológicas do município de Santa Maria, RS, Brasil. As condições para se considerar o dia como favorável para o trabalho com máquinas foram a precipitação < 5 mm e o armazenamento de água no solo (ARM entre 40 e 90% da capacidade de água disponível (CAD. O método da cadeia de Markov de primeira ordem foi utilizado para estimar as probabilidades condicionais de dias favoráveis ao trabalho com máquinas. Os resultados indicam que a metodologia aplicada para estimar as probabilidades de dias favoráveis ao uso de máquinas agrícolas foi viável, evidenciando as épocas mais apropriadas à execução de operações agrícolas mecanizadas no campo, para o município de Santa Maria, RS.

  17. Logística reversa de defensivos agrícolas: fatores que influenciam na consciência ambiental de agricultores gaúchos e mineiros

    Directory of Open Access Journals (Sweden)

    Wagner Junior Ladeira

    2012-03-01

    Full Text Available Nos últimos anos, observa-se um aumento das pressões legais e sociais em favor de uma maior preocupação com o meio ambiente em vários países, incluindo o Brasil. Se antes o foco era indústrias poluidoras, agora, também o setor agrícola sofre essas pressões. Considerando este cenário, o presente estudo tem como objetivo verificar quais são os principais fatores que levam produtores rurais a realizarem a logística reversa de embalagens de defensivos agrícolas. Para isso, foram aplicados questionários a 398 agricultores (residentes no Rio Grande do Sul e em Minas Gerais, produtores de soja, café, fumo, feijão e morango. Analisaram-se tanto as questões ambientais quanto as questões legais incluídas nesse processo. A fim de se atingir o objetivo proposto, foi adotada uma abordagem quantitativa, através da análise de regressão múltipla. No modelo de regressão estimado, observou-se que, dentro do processo de recolhimento de embalagens, três questões foram relacionadas à consciência ambiental: i manuseio de defensivos agrícolas e a legislação atual; ii adoção de tecnologia e de novas práticas e iii riscos a saúde humana. Nos achados empíricos a consciência ambiental recebe fortes interferências de fatores relacionados ao manuseio de defensivos agrícolas e da legislação atual.

  18. Reactor physics and economic aspects of the CANDU reactor system

    International Nuclear Information System (INIS)

    A history of the development of the CANDU system is given along with a fairly detailed description of the 600 MW(e) CANDU reactor. Reactor physics calculation methods are described, as well as comparisons between calculated reactor physics parameters and those measured in research and power reactors. An examination of the economics of CANDU in the Ontario Hydro system and a comparison between fossil fuelled and light water reactors is presented. Some physics, economics and resources aspects are given for both low enriched uranium and thorium-fuelled CANDU reactors. Finally the RβD program in Advanced Fuel Cycles is briefly described

  19. 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.

  20. Comparative analysis of agr groups and virulence genes among subclinical and clinical mastitis Staphylococcus aureus isolates from sheep flocks of the Northeast of Brazil

    Directory of Open Access Journals (Sweden)

    Lara M. de Almeida

    2013-01-01

    Full Text Available Staphylococcus aureus is one of the most frequent mastitis causative agents in small ruminants. The expression of most virulence genes of S. aureus is controlled by an accessory gene regulator (agrlocus. This study aimed to ascertain the prevalence of the different agr groups and to evaluate the occurrence of encoding genes for cytotoxin, adhesins and toxins with superantigen activity in S. aureus isolates from milk of ewes with clinical and subclinical mastitis in sheep flocks raised for meat production The agr groups I and II were identified in both cases of clinical and subclinical mastitis. Neither the arg groups III and IV nor negative agr were found. The presence of cflA gene was identified in 100% of the isolates. The frequency of hla and lukE-D genes was high -77.3 and 82.8%, respectively and all isolates from clinical mastitis presented these genes. The sec gene, either associated to tst gene or not, was identified only in isolates from subclinical mastitis. None of the following genes were identified: bbp, ebpS, cna, fnbB, icaA, icaD, bap, hlg, lukM-lukF-PV and se-a-b-d-e.

  1. Retos del crédito agrícola: estudio de caso de la intermediación financiera en el sur de Sonora, México

    Directory of Open Access Journals (Sweden)

    Mario Alberto Camiro Pérez

    2009-01-01

    Full Text Available En años recientes, la política agrícola oficial ha orientado sus esfuerzos para construir el sistema financiero rural sustentado en un arreglo institucional nuevo. En consecuencia, el Estado mexicano impulsó la creación de la Financiera Rural como banca de desarrollo, y así encaminar sus actividades en torno al crédito agrícola como servicio fundamental del sistema. Asimismo, con el fin de facilitar su transición como banca de segundo piso, se estableció un programa de apoyo a los intermediarios financieros rurales, para mejorar el servicio del crédito agrícola a los productores nacionales. En este contexto, el presente estudio analiza el papel de la Financiera Rural y los retos de la intermediación financiera, con base en un estudio de caso en el valle del Yaqui, Sonora, donde, a pesar de su potencial, las organizaciones de agricultores enfrentan restricciones importantes para acceder a servicios financieros e integrarlos a sus estrategias de desarrollo.

  2. Formação para o ensino agrícola nos Centros de treinamento de Professores e de auxiliares rurais (1952-1963

    Directory of Open Access Journals (Sweden)

    Iraíde Marques de Freitas Barreiro

    2013-01-01

    Full Text Available Este artículo analiza la enseñanza agrícola propuesta y desarrollada por la Campaña Nacional de Educación Rural (1952-1963 en los Centros de Entrenamientos de Profesores y Auxiliares Rurales. Se analizan los programas de enseñanza de esos cursos publicados en el volumen espacial, número 10, editado por la Campaña en 1961/1962. La enseñanza agrícola componía la educación rural y tenía como objetivo formar profesoras rurales y ampliar conocimientos del hombre del campo para estabilizarlo en su medio. Esa formación buscó suplir la falta de profesores rurales, de conocimientos agrícolas, higiene rural, fuertemente orientada por la “educación de las costumbres”, de como portarse a la mesa y la valoración del ocio racional, así como campañas de registro civil y casamientos, campaña de los árboles, incentivo para elegir representantes de los directorios como forma de educación para la ciudadanía. La ausencia de profesoras rurales y los bajos sueldos denunciados desnudan las prácticas de desvalorización docente de nuestros gobernantes.

  3. Fast breeder reactor research

    International Nuclear Information System (INIS)

    Full text: The meeting was attended by 15 participants from seven countries and two international organizations. The Eighth Annual Meeting of the International Working Group on Fast Reactors (IWGFR) was attended by representatives from France, Fed. Rep. Germany, Italy, Japan, United Kingdom, Union of Soviet Socialist Republics and the United States of America - countries that have made significant progress in developing the technology and physics of sodium cooled fast reactors and have extensive national programmes in this field - as well as by representatives of the Commission of the European Communities and the IAEA. The design of fast-reactor power plants is a more difficult task than developing facilities with thermal reactors. Different reactor kinetics and dynamics, a hard neutron spectrum, larger integral doses of fuel and structural material irradiation, higher core temperatures, the use of an essentially novel coolant, and, as a result of all these factors, the additional reliability and safety requirements that are imposed on the planning and operation of sodium cooled fast reactors - all these factors pose problems that can be solved comprehensively only by countries with a high level of scientific and technical development. The exchange of experience between these countries and their combined efforts in solving the fundamental problems that arise in planning, constructing and operating fast reactors are promoting technical progress and reducing the relative expenditure required for various studies on developing and introducing commercial fast reactors. For this reason, the meeting concentrated on reviewing and discussing national fast reactor programmes. The situation with regard to planning, constructing and operating fast experimental and demonstration reactors in the countries concerned, the experience accumulated in operating them, the difficulties arising during operation and ways of over-coming them, the search for optimal designs for the power

  4. BR2 Reactor: Introduction

    International Nuclear Information System (INIS)

    The irradiations in the BR2 reactor are in collaboration with or at the request of third parties such as the European Commission, the IAEA, research centres and utilities, reactor vendors or fuel manufacturers. The reactor also contributes significantly to the production of radioisotopes for medical and industrial applications, to neutron silicon doping for the semiconductor industry and to scientific irradiations for universities. Along the ongoing programmes on fuel and materials development, several new irradiation devices are in use or in design. Amongst others a loop providing enhanced cooling for novel materials testing reactor fuel, a device for high temperature gas cooled fuel as well as a rig for the irradiation of metallurgical samples in a Pb-Bi environment. A full scale 3-D heterogeneous model of BR2 is available. The model describes the real hyperbolic arrangement of the reactor and includes the detailed 3-D space dependent distribution of the isotopic fuel depletion in the fuel elements. The model is validated on the reactivity measurements of several tens of BR2 operation cycles. The accurate calculations of the axial and radial distributions of the poisoning of the beryllium matrix by 3He, 6Li and 3T are verified on the measured reactivity losses used to predict the reactivity behavior for the coming decades. The model calculates the main functionals in reactor physics like: conventional thermal and equivalent fission neutron fluxes, number of displacements per atom, fission rate, thermal power characteristics as heat flux and linear power density, neutron/gamma heating, determination of the fission energy deposited in fuel plates/rods, neutron multiplication factor and fuel burn-up. For each reactor irradiation project, a detailed geometry model of the experimental device and of its neighborhood is developed. Neutron fluxes are predicted within approximately 10 percent in comparison with the dosimetry measurements. Fission rate, heat flux and

  5. 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...

  6. 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.).

  7. Reactor coolant cleanup facility

    International Nuclear Information System (INIS)

    A depressurization device is disposed in pipelines upstream of recycling pumps of a reactor coolant cleanup facility to reduce a pressure between the pressurization device and the recycling pump at the downstream, thereby enabling high pressure coolant injection from other systems by way of the recycling pumps. Upon emergency, the recycling pumps of the coolant cleanup facility can be used in common to an emergency reactor core cooling facility and a reactor shutdown facility. Since existent pumps of the emergency reactor core cooling facility and the reactor shutdown facility which are usually in a stand-by state can be removed, operation confirmation test and maintenance for equipments in both of facilities can be saved, so that maintenance and reliability of the plant are improved and burdens on operators can also be mitigated. Moreover, low pressure design can be adopted for a non-regenerative heat exchanger and recycling coolant pumps, which enables to improve the reliability and economical property due to reduction of possibility of leakage. (N.H.)

  8. EBT reactor analysis

    International Nuclear Information System (INIS)

    This report summarizes the results of a recent ELMO Bumpy Torus (EBT) reactor study that includes ring and core plasma properties with consistent treatment of coupled ring-core stability criteria and power balance requirements. The principal finding is that constraints imposed by these coupling and other physics and technology considerations permit a broad operating window for reactor design optimization. Within this operating window, physics and engineering systems analysis and cost sensitivity studies indicate that reactors with approx. 6 to 10%, P approx. 1200 to 1700 MW(e), wall loading approx. 1.0 to 2.5 MW/m2, and recirculating power fraction (including ring-sustaining power and all other reactors auxiliaries) approx. 10 to 15% are possible. A number of concept improvements are also proposed that are found to offer the potential for further improvement of the reactor size and parameters. These include, but are not limited to, the use of: (1) supplementary coils or noncircular mirror coils to improve magnetic geometry and reduce size, (2) energetic ion rings to improve ring power requirements, (3) positive potential to enhance confinement and reduce size, and (4) profile control to improve stability and overall fusion power density

  9. Generalities about nuclear reactors

    International Nuclear Information System (INIS)

    From Zoe, the first nuclear reactor, till the current EPR, the French nuclear industry has always advanced by profiting from the feedback from dozens of years of experience and operations, in particular by drawing lessons from the most significant events in its history, such as the Fukushima accident. The new generations of reactors must improve safety and economic performance so that the industry maintain its legitimacy and its share in the production of electricity. This article draws the history of nuclear power in France, gives a brief description of the pressurized water reactor design, lists the technical features of the different versions of PWR that operate in France and compares them with other types of reactors. The feedback experience concerning safety, learnt from the major nuclear accidents Three Miles Island (1979), Chernobyl (1986) and Fukushima (2011) is also detailed. Today there are 26 third generation reactors being built in the world: 4 EPR (1 in Finland, 1 in France and 2 in China); 2 VVER-1200 in Russia, 8 AP-1000 (4 in China and 4 in the Usa), 8 APR-1400 (4 in Korea and 4 in UAE), and 4 ABWR (2 in Japan and 2 in Taiwan)

  10. Violencia laboral contra jornaleras agrícolas en tres comunidades del noroeste de México

    Directory of Open Access Journals (Sweden)

    Ma. del Carmen Arellano Gálvez

    2014-01-01

    Full Text Available El objetivo de este artículo es analizar las formas de violencia laboral contra mujeres jornaleras agrícolas en tres comunidades de Sinaloa, Sonora y Baja California, para lo que se utilizó una metodología cualitativa, a través de entrevistas grupales que se les hicieron a ellas. Los resultados señalan que las trabajadoras reconocen la violación a sus derechos laborales, como no contar con servicios médicos para ellas y sus hijos, ni ingresos por faltar al trabajo cuando éstos enferman y menos opciones laborales durante el embarazo. A diario viven el acoso y el hostigamiento ejercido por hombres posicionados en distintas jerarquías laborales, pero no son pasivas ante la violencia, ya que diseñan estrategias de autocuidado. Otras se organizan para brindar asesoría a mujeres sobre sus derechos laborales y las acompañan en los procesos de denuncia y búsqueda de justicia.

  11. Biodegradación de diesel mexicano por un consorcio de bacterias de un suelo agrícola

    Directory of Open Access Journals (Sweden)

    Santiago Cardona

    2003-01-01

    Full Text Available Se realiza la biodegradación de diesel presente en agua por medio de microorganismos de un suelo agrícola. Se determina la cinética de biotransformación y adsorción del diesel para su aplicación en los proyectos de saneamiento de suelos y acuíferos contaminados con diesel. Se presenta la metodología y los resultados de la biodegradación y la adsorción del diesel contenido en agua sintética así como la caracterización del suelo de cultivo seleccionado para el estudio. La degradación se realiza utilizando los microorganismos nativos del suelo de cultivo seleccionado, al cual se le suministra nitrógeno como nutriente y sin él. El peróxido de hidrógeno se suministra como fuente de oxígeno. Por último se presentan los análisis de las cinéticas que determinan la volatilización del diesel. Con los resultados obtenidos se determinan las ecuaciones cinéticas de degradación, adsorción y se calcularon las constantes de velocidad.

  12. La producción agrícola fronteriza 1977-1981: un análisis estructural

    Directory of Open Access Journals (Sweden)

    Arturo Ranfla González

    1986-01-01

    Full Text Available Este trabajo constituye un intento por estudiar la estructura de la producción agrícola regional y un ensayo por medir la sensibilidad de los estados fronterizos con respecto al mercado externo e interno utilizando modelos del análisis regional, tratando de ir más allá de la pura descripción, buscando inferir a través de un estudio descriptivo, una explicación más general sobre los mecanismos intervinientes. De acuerdo a los resultados de este análisis en el Estado de Baja California, se sugiere un alto grado de integración con respecto al exterior, lo cual se manifiesta en menor proporción en la agricultura de riego de las entidades de Tamaulipas y Nuevo León, lo que nos lleva a sugerir la importancia que tiene analizar en una secuencia similar los distritos de riego fronterizos.

  13. Aerodinámica de la corriente de aire de un pulverizador agrícola con ventilador centrifugo

    Directory of Open Access Journals (Sweden)

    Mario Ignacio Herrera Prat

    2009-01-01

    Full Text Available Las contaminaciones medioambientales debido a que las gotas del pesticida no alcanzan el blanco y el creciente aumento en las aplicaciones se han vuelto un problema de salud medioambiental. En la aplicación de defensivos agrícolas a los frutales los pulverizadores más utilizados son los que se auxilian de corriente de aire para el traslado de la gota al árbol. Los ventiladores axiales con salida radial es el esquema más extendido, aunque con éxito también se emplean los ventiladores centrífugos en la construcción de los pulverizadores. La aerodinámica de la corriente de aire es la que decide en la calidad de la aplicación y el régimen de trabajo en este equipo. En el trabajo se estudia la aerodinámica de la corriente de aire del pulverizador "MARTIGNANI"5 que utiliza el ventilador centrífugo "MAJOR"5 que distribuye el aire en cuatro salidas. En el estudio se determinara la velocidad del aire, su uniformidad, caudal en las salidas y se analiza la corriente de aire aplicando modelos matemáticos. Se caracteriza la aerodinámica del pulverizador para fundamentar regimenes de trabajo racionales.

  14. Hongos de importancia agrícola presentes en moscas de la fruta del valle de Ica, Perú

    Directory of Open Access Journals (Sweden)

    Carlos E. Tipismana

    2013-05-01

    Full Text Available El objetivo del presente trabajo fue aislar e identificar hongos de especímenes de moscas de la fruta de los géneros Ceratitis (Macleay y Anastrepha (Schiner, del valle de Ica, Perú. Se aislaron hongos pertenecientes a los géneros Alternaria, Aspergillus, Cladosporium, Mucor, Penicillium, Rhizoctonia, Rhizopus y Trichoderma;así como levaduras y micelios estériles. Los recuentos de hongos presentaron rangos entre 8x103 a 8x104 UFC/g para el género Ceratitis; y 7x103 a 7x104 UFC/g para el género Anastrepha. El IVI% (Índice de Valor de Importancia demostró que Cladosporium es el género con mayor valor ecológico con un 78,05%. El Índice de Similitud de especies de hongos entre ambos géneros de mosca de la fruta analizados fue 0,5. Los resultados obtenidos confirman la presencia de hongos en moscas de la fruta; y se deduce el posible impacto de estos dípteros en el área agrícola como potenciales agentes vectores de enfermedades fúngicas para los cultivos locales de importancia económica.

  15. Impactos Ambientais das Atividades Agrícolas em Roraima. = Environmental Impacts of Agriculture Activity in Roraima State.

    Directory of Open Access Journals (Sweden)

    Valdinar Ferreira Melo

    2008-07-01

    Full Text Available A agricultura foi a grande responsável pelo processo de colonização do Brasil. No entanto, estas atividades se desenvolveram ás expensas de ações negativamente impactantes ao meio ambiente. Este trabalho tem com objetivo abordar os impactos ambientais causados pela atividade agrícola no estado de Roraima, despertando o interesse da comunidade para o uso de uma agricultura fundamentada no conceito de sustentabilidade. A prática agropecuária no Brasil, inicialmente de forma empírica, sem muito conhecimento e preocupação com seus efeitos no ambiente, causou a dizimação de grande parte das florestas e a biodiversidade, mas, também, possibilitou a ocupação da terra e a definição dos limites territoriais brasileiros, definindo-se como de grande importância para a sustentação da economia, imprimindo ao Brasil sua vocação agrícola. A atividade nos anos 60 foi concebida para a validação de pacotes tecnológicos importados, contribuiu para a execução de práticas socialmente excludentes e ambientalmente danosas, com reflexos positivos na produção agrícola e comércio de insumos, à custa da implantação de sistemas monoculturais, com motomecanização, irrigação e emprego intensivo de fertilizantes químicos e pesticidas. A impropriedade ambiental deste modelo originou movimentos que culminaram com a conscientização para estas questões, tendo como respostas a elaboração de instrumentos técnicos e jurídicos, e formulação de propostas para avaliar e mitigar os impactos ambientais e modificar as ações humanas, tornando-as mais condizentes com novos paradigmas da sociedade. Em Roraima, esta atividade sofre uma nova mudança, onde as técnicas primitivas de exploração agrícola começam a ser substituídas por atividades tecnificadas com o uso intensivo de tecnologias, com risco de improbidade ambiental que pode culminar com a degradação do meio, caso não haja uma perícia profunda das caracter

  16. Los Objetos de Aprendizaje en la carrera de Ingeniería Agrícola: modalidad semipresencial

    Directory of Open Access Journals (Sweden)

    Nelson Nápoles Hernández

    2011-01-01

    Full Text Available De las innovaciones tecnológicas más significativas de los últimos años, sin duda Internet tiene el potencial de producir un cambio de paradigma en el modo en el que las personas se educan. Por ello, repercute en el modo en que se deben, preparar los materiales educativos para ponerlos a disposición en la comunidad universitaria. En la actualidad se comienza a vislumbrar que los Objetos de Aprendizajes (OA son especialmente atractivos para el mundo digital y por ende para la educación virtual. De ahí su importancia en las carreras agropecuarias cubanas especialmente en la de Ingeniería Agrícola, teniendo en cuenta los nuevos retos de la Nueva Universidad Cubana. Las exigencias en la elaboración de OA , permitirá que los contenidos que se elaboren para dicha carrera puedan soportarse correctamente en correspondencia con los estándares establecidos internacionalmente y estos puedan ser catalogados, clasificados e indizados sin dificultad alguna.

  17. Uso de plaguicidas en cultivos agrícolas como herramienta para el monitoreo de peligros en salud

    Directory of Open Access Journals (Sweden)

    Virya Bravo Durán

    2013-03-01

    Full Text Available Costa Rica ha incrementado el uso de plaguicidas de mayor toxicidad, debido entre otras cosas al desarrollo de plagas más resistentes y la necesidad que tienen algunos productos agrícolas de exportación de mantener su posición en el mercado internacional. El ser humano al entrar en contacto con los plaguicidas puede experimentar efectos adversos en su salud desde agudos hasta crónicos que se manifiestan en diferentes grados. Para generar indicadores de peligro en salud en algunos cultivos por el uso de estas sustancias, se utilizaron la cantidad de plaguicidas aplicada y su toxicidad. Los datos de uso se recopilan directamente de los productores, a través de un cuestionario, los ingredientes activos identificados se caracterizaron por su toxicidad y se clasificaron por la manifestación de los efectos. Se calculó como indicador la cantidad de plaguicidas aplicada (kg ia/ha/año por las clases de toxicidad consideradas más peligrosas: 1. Efectos de toxicidad aguda en grado de alto a extremo y 2. Tres o más efectos crónicos positivos. Se recomienda vigilar el uso de bromuro de metilo, metam sodio, terbufos, etoprofos, endosulfan, MCPA y carbofuran por toxicidad aguda de alta a extrema y mancozeb, paraquat, diazinon, 2,4-D y carbofuran por efectos crónicos.  

  18. 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.

  19. Mimic of OSU research reactor

    International Nuclear Information System (INIS)

    The Ohio State University research reactor (OSURR) is undergoing improvements in its research and educational capabilities. A computer-based digital data acquisition system, including a reactor system mimic, will be installed as part of these improvements. The system will monitor the reactor system parameters available to the reactor operator either in digital parameters available to the reactor operator either in digital or analog form. The system includes two computers. All the signals are sent to computer 1, which processes the data and sends the data through a serial port to computer 2 with a video graphics array VGA monitor, which is utilized to display the mimic system of the reactor

  20. Methanation assembly using multiple reactors

    Science.gov (United States)

    Jahnke, Fred C.; Parab, Sanjay C.

    2007-07-24

    A methanation assembly for use with a water supply and a gas supply containing gas to be methanated in which a reactor assembly has a plurality of methanation reactors each for methanating gas input to the assembly and a gas delivery and cooling assembly adapted to deliver gas from the gas supply to each of said methanation reactors and to combine water from the water supply with the output of each methanation reactor being conveyed to a next methanation reactor and carry the mixture to such next methanation reactor.

  1. MINT research reactor safety program

    Energy Technology Data Exchange (ETDEWEB)

    Mohamad Idris bin Taib [Division of Special Project, Malaysian Institute for Nuclear Technology Research (MINT), Bangi (Malaysia)

    2000-11-01

    Malaysian Institute for Nuclear Technology Research (MINT) Research Reactor Safety Program has been done along with Reactor Power Upgrading Project, Reactor Safety Upgrading Project and Development of Expert System for On-Line Nuclear Process Control Project. From 1993 up to date, Neutronic and Thermal-hydraulics analysis, Probabilistic Safety Assessment as well as installation of New 2 MW Secondary Cooling System were done. Installations of New Reactor Building Ventilation System, Reactor Monitoring System, Updating of Safety Analysis Report and Upgrading Primary Cooling System are in progress. For future activities, Reactor Modeling will be included to add present activities. (author)

  2. 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.

  3. International Thermonuclear Experimental Reactor

    International Nuclear Information System (INIS)

    An international design team comprised of members from Canada, Europe, Japan, the Soviet Union, and the United States of America, are designing an experimental fusion test reactor. The engineering and testing objectives of this International Thermonuclear Experimental Reactor (ITER) are to validate the design and to demonstrate controlled ignition, extended burn of a deuterium and tritium plasma, and achieve steady state using technology expected to be available by 1990. The concept maximizes flexibility while allowing for a variety of plasma configurations and operating scenarios. During physics phase operation, the machine produces a 22 MA plasma current. In the technology phase, the machine can be reconfigured with a thicker shield and a breeding blanket to operate with an 18 MA plasma current at a major radius of 5.5 meters. Canada's involvement in the areas of safety, facility design, reactor configuration and maintenance builds on our internationally recognized design and operational expertise in developing tritium processes and CANDU related technologies

  4. Licensed operating reactors

    International Nuclear Information System (INIS)

    The US Nuclear Regulatory Commission's monthly Licensed Operating Reactors Status Summary Report provides data on the operation of nuclear units as timely and accurately as possible. This information is collected by the Office of Information Resources Management, from the Headquarters Staff of NRC's Office of Inspection and Enforcement, from NRC's Regional Offices, and from utilities. This report is divided into three sections: the first contains monthly highlights and statistics for commercial operating units, and errata from previously reported data; the second is a compilation of detailed information on each unit, provided by NRC Regional Offices, IE Headquarters and the Utilities; and the third section is an appendix for miscellaneous information such as spent fuel storage capability, reactor years of experience and non-power reactors in the United States

  5. Licensed operating reactors

    International Nuclear Information System (INIS)

    THE OPERATING UNITS STATUS REPORT - LICENSED OPERATING REACTORS provides data on the operation of nuclear units as timely and accurately as possible. This information is collected by the Office of Information Resources Management from the Headquarters staff of NRC's Office of Enforcement (OE), from NRC's Regional Offices, and from utilities. The three sections of the report are: monthly highlights and statistics for commercial operating units, and errata from previously reported data; a compilation of detailed information on each unit, provided by NRC's Regional Offices, OE Headquarters and the utilities; and an appendix for miscellaneous information such as spent fuel storage capability, reactor-years of experience and non-power reactors in the US

  6. Licensed operating reactors

    International Nuclear Information System (INIS)

    The US Nuclear Regulatory Commission's monthly LICENSED OPERATING REACTORS Status Summary Report provides data on the operation of nuclear units as timely and accurately as possible. This information is collected by the Office of Information Resources Management, from the Headquarters Staff of NRC's Office of Inspection and Enforcement, from NRC's Regional Offices, and from utilities. This report is divided into three sections: the first contains monthly highlights and statistics for commercial operating units, and errata from previously reported data; the second is a compilation of detailed information on each unit, provided by NRC Regional Offices, IE Headquarters and the Utilities; and the third section is an appendix for miscellaneous information such as spent fuel storage capability, reactor years of experience and non-power reactors in the United States

  7. Reactor safety equipments

    International Nuclear Information System (INIS)

    Purpose: To positively recover radioactive substances discharged in a dry well at the time of failure of a reactor. Constitution: In addition to the emergency gas treating system fitted to a reactor building, a purification system connected through a pipeline to the dry well is arranged in the reactor building. This purification system is connected through pipes fitted to the dry well to forced circulation device, heat exchanger, and purification device. The atmosphere of high pressure steam gases in the dry well is derived to the heat exchanger for cooling, and then radioactive substances which are contained in the gases are removed by filter sets charged with the HEPA filters and the HECA filters. At last, there gases are returned to dry well by circulation pump, repeat this process. (Kamimura, M.)

  8. Licensed operating reactors

    International Nuclear Information System (INIS)

    The US Nuclear Regulatory Commission's monthly LICENSED OPERATING REACTORS Status Summary Report provides data on the operation of nuclear units as timely and accurately as possible. This information is collected by the Office of Information Resources Management, from the Headquarters Staff of NRC's Office of Inspection and Enforcement, from NRC's Regional Offices, and from utilities. This report is divided into three sections: the first contains monthly highlights and statistics for commercial operating units, and errata from previously reported data; the second is a compilation of detailed information on each unit, provided by NRC Regional Offices, IE Headquarters and the utilities; and the third section is an appendix for miscellaneous information such as spent fuel storage capability, reactor years of experience and non-power reactors in the United States

  9. Welding and reactor safety

    International Nuclear Information System (INIS)

    The high safety requirements which must be demanded of the quality of the welded joints in reactor technique have so far not been fulfilled in all cases. The errors occuring have caused considerable loss of availability and high material costs. They were not, however, so serious that one need have feared any immediate danger to the personnel or to the environment. The safety devices of reactor plants were only called upon in a few cases and to these they responded perfectly. The intensive efforts to complete and improve the specifications are to contribute to that in future, the reactor plants can be counted even more so as one of the safest technical plants ever. (orig./LH)

  10. Backfitting swimming pool reactors

    International Nuclear Information System (INIS)

    Calculations based on measurements in a critical assembly, and experiments to disclose fuel element surface temperatures in case of accidents like stopping of primary coolant flow during full power operation, have shown that the power of the swimming pool type research reactor FRG-2 (15 MW, operating since 1967) might be raised to 21 MW within the present rules of science and technology, without major alterations of the pool buildings and the cooling systems. A backfitting program is carried through to adjust the reactor control systems of FRG-2 and FRG-1 (5 MW, housed in the same reactor hall) to the present safety rules and recommendations, to ensure FRG-2 operation at 21 MW for the next decade. (author)

  11. Reactor operation experience

    International Nuclear Information System (INIS)

    Since the TRIGA Users Conference in Helsinki 1970 the TRIGA reactor Vienna was in operation without any larger undesired shutdown. The integrated thermal power production by August 15 1972 accumulated to 110 MWd. The TRIGA reactor is manly used for training of students, for scientific courses and research work. Cooperation with industry increased in the last two years either in form of research or in performing training courses. Close cooperation is also maintained with the IAEA, samples are irradiated and courses on various fields are arranged. Maintenance work was performed on the heat exchanger and to replace the shim rod magnet. With the view on the future power upgrading nine fuel elements type 110 have been ordered recently. Experiments, performed currently on the reactor are presented in details

  12. The MNSR reactor

    International Nuclear Information System (INIS)

    This tank-in-pool reactor is based on the same design concept as the Canadian Slowpoke. The core is a right circular cylinder, 24 cm diameter by 25 cm long, containing 411 fuel pin positions. The pins are HEU-Aluminium alloy, 0.5 cm in diameter. Critical mass is about 900 g. The reactor has a single cadmium control rod. The back-up shutdown system is the insertion of a cadmium capsule in a core position. Excess reactivity is limited to 3.5mk. In both the MNSR and Slowpoke, the insertion of the maximum excess reactivity results in a power transient limited by the coolant/moderator temperature to safe values, independent of any operator action. This reactor is used primarily in training and neutron activation analysis. Up to 64 elements have been analyzed in a great variety of different disciplines. (author)

  13. 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.

  14. Fusion reactor materials

    International Nuclear Information System (INIS)

    This is the fifteenth in a series of semiannual technical progress reports on fusion reactor materials. This report combines research and development activities which were previously reported separately in the following progress reports: Alloy Development for Irradiation Performance; Damage Analysis and Fundamental Studies; Special purpose Materials. These activities are concerned principally with the effects of the neutronic and chemical environment on the properties and performance of reactor materials; together they form one element of the overall materials programs being conducted in support of the Magnetic Fusion Energy Program of the U.S. Department of Energy. The Fusion Reactor Materials Program is a national effort involving several national laboratories, universities, and industries. The purpose of this series of reports is to provide a working technical record for the use of the program participants, and to provide a means of communicating the efforts of materials scientists to the rest of the fusion community, both nationally and worldwide

  15. Safety systems of heavy water reactors and small power reactors

    International Nuclear Information System (INIS)

    After introductional descriptions of heavy water reactors and natural circulation boiling water reactors the safety philosophy and safety systems like ECCS, residual heat removal, protection systems etc., are described. (RW)

  16. Practical decommissioning experience with nuclear installations in the European Community

    International Nuclear Information System (INIS)

    Initiated by the Commission of the European Communities (CEC), this seminar was jointly organized by the AEA, BNFL and the CEC at Windermere and the sites of Windscale/Sellafield, where the former Windscale advanced gas-cooled reactor and the Windscale piles are currently being dismantled. The meeting aimed at gathering a limited number of European experts for the presentation and discussion of operations, results and conclusions on techniques and procedures currently applied in the dismantling of large scale nuclear installations in the European Community

  17. Frequency and distribution of leakages in steam generators of gas-cooled reactors

    International Nuclear Information System (INIS)

    In gas cooled reactors with graphitic primary circuit structures - such as HTR, AGR or Magnox - the water ingress is an event of great safety concern. Water or steam entering the primary circuit react with the hot graphite and carbon-oxide and hydrogen are produced. As the most important initiating event a leak in a steam generator must be taken into account. From the safety point of view as well as for availability reasons it is necessary to construct reliable boilers. Thus the occurrence of a boiler leak should be a rare event. In the context of a probabilistic safety study for an HTR-Project much effort was invested to get information about the frequency and the size distribution of tube failures in steam generators of gas cooled reactors. The main data base was the boiler tube failure statistics of United Kingdom gas cooled reactors. The data were selected and applied to a modern HTR steam generator design. A review of the data showed that the failure frequency is not connected with the load level (pressures, temperatures) or with the geometric size of the heating surface of the boiler. Design, construction, fabrication, examination and operation conditions have the greatest influence an the failure frequency but they are practically not to be quantified. The typical leak develops from smallest size. By erosion effects of the entering water or steam it is enlarged to perhaps some mm2, then usually it is detected by moisture monitors. Sudden tube breaks were not reported in the investigated period. As a rule boiler leaks in gas cooled reactors are much more, rare then leaks in steam generators of light water reactors and fossil fired boilers. (author)

  18. AREVA's nuclear reactors portfolio

    International Nuclear Information System (INIS)

    A reasonable assumption for the estimated new build market for the next 25 years is over 340 GWe net. The number of prospect countries is growing almost each day. To address this new build market, AREVA is developing a comprehensive portfolio of reactors intended to meet a wide range of power requirements and of technology choices. The EPR reactor is the flagship of the fleet. Intended for large power requirements, the four first EPRs are being built in Finland, France and China. Other countries and customers are in view, citing just two examples: the Usa where the U.S. EPR has been selected as the technology of choice by several U.S utilities; and the United Kingdom where the Generic Design Acceptance process of the EPR design submitted by AREVA and EDF is well under way, and where there is a strong will to have a plant on line in 2017. For medium power ranges, the AREVA portfolio includes a boiling water reactor and a pressurized water reactor which both offer all of the advantages of an advanced plant design, with excellent safety performance and competitive power generation cost: -) KERENA (1250+ MWe), developed in collaboration with several European utilities, and in particular with Eon; -) ATMEA 1 (1100+ MWe), a 3-loop evolutionary PWR which is being developed by AREVA and Mitsubishi. AREVA is also preparing the future and is deeply involved into Gen IV concepts. It has developed the ANTARES modular HTR reactor (pre-conceptual design completed) and is building upon its vast Sodium Fast Reactor experience to take part into the development of the next prototype. (author)

  19. 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.

  20. Reactor Materials Research

    International Nuclear Information System (INIS)

    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

  1. Nuclear reactor simulator

    International Nuclear Information System (INIS)

    The Nuclear Reactor Simulator was projected to help the basic training in the formation of the Nuclear Power Plants operators. It gives the trainee the opportunity to see the nuclear reactor dynamics. It's specially indicated to be used as the support tool to NPPT (Nuclear Power Preparatory Training) from NUS Corporation. The software was developed to Intel platform (80 x 86, Pentium and compatible ones) working under the Windows operational system from Microsoft. The program language used in development was Object Pascal and the compiler used was Delphi from Borland. During the development, computer algorithms were used, based in numeric methods, to the resolution of the differential equations involved in the process. (author)

  2. Diagnostics for hybrid reactors

    International Nuclear Information System (INIS)

    The Hybrid Reactor(HR) can be considered an attractive actinide-burner or a fusion assisted transmutation for destruction of transuranic(TRU) nuclear waste. The hybrid reactor has two important subsystems: the tokamak neutron source and the blanket which includes a fuel zone where the TRU are placed and a tritium breeding zone. The diagnostic system for a HR must be as simple and robust as possible to monitor and control the plasma scenario, guarantee the protection of the machine and monitor the transmutation.

  3. Small mirror fusion reactors

    International Nuclear Information System (INIS)

    Basic requirements for the pilot plants are that they produce a net product and that they have a potential for commercial upgrade. We have investigated a small standard mirror fusion-fission hybrid, a two-component tandem mirror hybrid, and two versions of a field-reversed mirror fusion reactor--one a steady state, single cell reactor with a neutral beam-sustained plasma, the other a moving ring field-reversed mirror where the plasma passes through a reaction chamber with no energy addition

  4. Reactor neutron dosimetry

    International Nuclear Information System (INIS)

    An analysis of requirements and possibilities for experimental neutron spectrum determination during the reactor pressure vessel surveil lance programme is given. Fast neutron spectrum and neutron dose rate were measured in the Fast neutron irradiation facility of our TRIGA reactor. It was shown that the facility can be used for calibration of neutron dosimeters and for irradiation of samples sensitive to neutron radiation. The investigation of the unfolding algorithm ITER was continued. Based on this investigations are two specialized unfolding program packages ITERAD and ITERGS written this year. They are able to unfold data from activation detectors and NaI(T1) gamma spectrometer respectively

  5. Perspectives on reactor safety

    International Nuclear Information System (INIS)

    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

  6. 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.

  7. Nuclear reactor constructions

    International Nuclear Information System (INIS)

    A nuclear reactor construction comprising a reactor core submerged in a pool of liquid metal coolant in a primary vessel which is suspended from the roof structure of a containment vault. Control rods supported from the roof structure are insertable in the core which is carried on a support structure from the wall of the primary vessel. To prevent excessive relaxation of the support structure whereby the control rods would be displaced relative to the core, the support structure incorporates a normally inactive secondary structure designed to become effective in bracing the primary structure against further relaxation beyond a predetermined limit. (author)

  8. 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.

  9. Reactor gamma spectrometry: status

    International Nuclear Information System (INIS)

    Current work is described for Compton Recoil Gamma-Ray Spectrometry including developments in experimental technique as well as recent reactor spectrometry measurements. The current status of the method is described concerning gamma spectromoetry probe design and response characteristics. Emphasis is given to gamma spectrometry work in US LWR and BR programs. Gamma spectrometry in BR environments are outlined by focussing on start-up plans for the Fast Test Reactor (FTR). Gamma spectrometry results are presented for a LWR pressure vessel mockup in the Poolside Critical Assembly (PCA) at Oak Ridge National Laboratory

  10. 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.

  11. Precaución, riesgo y sostenibilidad en los organismos agrícolas modificados genéticamente Precaución, riesgo y sostenibilidad en los organismos agrícolas modificados genéticamente

    Directory of Open Access Journals (Sweden)

    J. David Tábara

    2003-01-01

    Full Text Available El cultivo y la comercialización de Organismos Agrícolas Modificados Genéticamente (0MG es origen de multitud de importantes polémicas sociales, económicos y ecológicas, en cuya resolución a menudo se reclama la incorporación del principio y de prácticas de precaución. Este artículo introduce y analiza algunas de estas discusiones a partir de la perspectiva aportada por el proyecto europeo Precautionary Expertise for GM Crops (PEG sobre la aplicación de la precaución en el desarrollo y la comercialización de OMG agrícolas. A partir del material recogido en el caso español, los autores argumentan que gran parte de los desacuerdos que surgen de en la interpretación y aplicación de la precaución con relación a los OMG derivan de la adopción de una perspectiva más o menos reduccionista, o más o menos sistémica, tanto en la evaluación y regulación de los riesgos como en la bondad, los costes o los beneficios de su utilización. Por ello es posible detectar analíticamente, paro el caso español, una clara oposición entre aquellas interpretaciones de la precaución caso por caso, de aquellas que sostienen la necesidad de aplicar prácticas de evaluación y de gestión basadas en una precaución sistémica, más cercano a los principios y los postulados políticos de la sostenibilidad.The debate over GMO crops and their commercialisation becomes the source of a large number of conflicts with important social, economic and ecologic consequences the resolution of which often calls for the application of a precautionary approach and of the precautionary principle. This article introduces and analyses such discussions, and does so within the framework provided by the EU project Precautionary Expertise for GM (PEG. Based on first material gathered for the Spanish case study, the authors argue that a large majority of the disagreements around practical application of precaution over agricultural GMO in Spain come from a conception

  12. Risk prevention during reactor shutdown

    International Nuclear Information System (INIS)

    During reactor shutdown potential risks are issued of a number of maintenance operations. In this text we analyse these operations and give the modifications of technical specifications to ameliorate the reactor safety. 4 figs

  13. Power calibrations for TRIGA reactors

    International Nuclear Information System (INIS)

    The purpose of this paper is to establish a framework for the calorimetric power calibration of TRIGA reactors so that reliable results can be obtained with a precision better than ± 5%. Careful application of the same procedures has produced power calibration results that have been reproducible to ± 1.5%. The procedures are equally applicable to the Mark I, Mark II and Mark III reactors as well as to reactors having much larger reactor tanks and to TRIGA reactors capable of forced cooling up to 3 MW in some cases and 15 MW in another case. In the case of forced cooled TRIGA reactors, the calorimetric power calibration is applicable in the natural convection mode for these reactors using exactly the same procedures as are discussed below for the smaller TRIGA reactors (< 2 MW)

  14. Reactor Engineering Department annual report

    International Nuclear Information System (INIS)

    Research and development activities in the Department of Reactor Engineering in fiscal 1982 are described. The work of the Department is closely related to development of multipurpose Very High Temperature Gas Cooled Reactor and Fusion Reactor, and development of Liquid Metal Fast Breeder Reactor carried out by Power Reactor and Nuclear Fuel Development Corporation. Since fiscal 1982, Systematic research and development work on safeguards technology has been added to the activities of the Department. Contents of the report are achievements in fields such as nuclear data and group constants, theoretical method and code development, integral experiment and analysis, fusion neutronics, shielding, reactor and nuclear instrumentation, reactor control and diagnosis, and safeguards technology, and activities of the Committee on Reactor Physics. (author)

  15. Operating reactors licensing actions summary

    International Nuclear Information System (INIS)

    The Operating Reactors Licensing Actions Summary is designed to provide the management of the Nuclear Regulatory Commission (NRC) with an overview of licensing actions dealing with operating power and nonpower reactors

  16. 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.

  17. 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...

  18. 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)

  19. Reactor safety in Eastern Europe

    International Nuclear Information System (INIS)

    The papers presented to the GRS colloquium refer to the cooperative activities for reactor accident analysis and modification of the GRS computer codes for their application to reactors of the Russian design types of WWER or RBMK. Another topic is the safety of RBMK reactors in particular, and the current status of investigations and studies addressing the containment of unit 4 of the Chernobyl reactor station. All papers are indexed separately in report GRS--117. (HP)

  20. Fast reactor programme

    International Nuclear Information System (INIS)

    This progress report summarizes the fast reactor research carried out by ECN during the period covering the year 1980. This research is mainly concerned with the cores of sodium-cooled breeders, in particular the SNR-300, and its related safety aspects. It comprises six items: A programme to determine relevant nuclear data of fission- and corrosion-products; A fuel performance programme comprising in-pile cladding failure experiments and a study of the consequences of loss-of-cooling and overpower; Basic research on fuel; Investigation of the changes in the mechanical properties of austenitic stainless steel DIN 1.4948 due to fast neutron doses, this material has been used in the manufacture of the reactor vessel and its internal components; Study of aerosols which could be formed at the time of a fast reactor accident and their progressive behaviour on leaking through cracks in the concrete containment; Studies on heat transfer in a sodium-cooled fast reactor core. As fast breeders operate at high power densities, an accurate knowledge of the heat transfer phenomena under single-phase and two-phase conditions is sought. (Auth.)

  1. Thermal Reactor Safety

    International Nuclear Information System (INIS)

    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. NEUTRONIC REACTOR FUEL ELEMENT

    Science.gov (United States)

    Picklesimer, M.L.; Thurber, W.C.

    1961-01-01

    A chemically nonreactive fuel composition for incorporation in aluminum- clad, plate type fuel elements for neutronic reactors is described. The composition comprises a mixture of aluminum and uranium carbide particles, the uranium carbide particles containing at least 80 wt.% UC/sub 2/.

  3. Stabilized Spheromak Fusion Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Fowler, T

    2007-04-03

    The U.S. fusion energy program is focused on research with the potential for studying plasmas at thermonuclear temperatures, currently epitomized by the tokamak-based International Thermonuclear Experimental Reactor (ITER) but also continuing exploratory work on other plasma confinement concepts. Among the latter is the spheromak pursued on the SSPX facility at LLNL. Experiments in SSPX using electrostatic current drive by coaxial guns have now demonstrated stable spheromaks with good heat confinement, if the plasma is maintained near a Taylor state, but the anticipated high current amplification by gun injection has not yet been achieved. In future experiments and reactors, creating and maintaining a stable spheromak configuration at high magnetic field strength may require auxiliary current drive using neutral beams or RF power. Here we show that neutral beam current drive soon to be explored on SSPX could yield a compact spheromak reactor with current drive efficiency comparable to that of steady state tokamaks. Thus, while more will be learned about electrostatic current drive in coming months, results already achieved in SSPX could point to a productive parallel development path pursuing auxiliary current drive, consistent with plans to install neutral beams on SSPX in the near future. Among possible outcomes, spheromak research could also yield pulsed fusion reactors at lower capital cost than any fusion concept yet proposed.

  4. Reactors. Nuclear propulsion ships

    International Nuclear Information System (INIS)

    This article has for object the development of nuclear-powered ships and the conception of the nuclear-powered ship. The technology of the naval propulsion P.W.R. type reactor is described in the article B.N.3 141 'Nuclear Boilers ships'. (N.C.)

  5. Pressure tube type reactor

    International Nuclear Information System (INIS)

    Heretofore, a pressure tube type reactor has a problem in that the evaluation for the reactor core performance is complicate and no sufficient consideration is made for the economical property, to increase the size of a calandria tank and make the cost expensive. Then, in the present invention, the inner diameter of a pressure tube is set to greater than 50% of the lattice gap in a square lattice like arrangement, and the difference between the inner and the outer diameters of the calandria tube is set smaller than 20% of the lattice gap. Further, the inner diameter of the pressure tube is set to greater than 40% and the difference between the inner and the outer diameters of the calandria tube is set smaller than 30% of the lattice gap in a triangle lattice arrangement. Then, heavy water-to-fuel volume ratio can be determined appropriately and the value for the coolant void coefficient is made more negative side, to improve the self controllability inherent to the reactor. In particular, when 72 to 90 fuel rods are arranged per one pressure tube, the power density per one fuel rod is can be increased by about twice. Accordingly, the number of the pressure tubes can be reduced about to one-half, thereby enabling to remarkably decrease the diameter of the reactor core and to reduce the size of the calandria, which is economical. (N.H.)

  6. Fusion reactor materials

    International Nuclear Information System (INIS)

    At the Belgian Nuclear Research Centre SCK-CEN, activities related to fusion focus on environmental tolerance of opto-electronic components. The objective of this program is to contribute to the knowledge on the behaviour, during and after neutron irradiation, of fusion-reactor materials and components. The main scientific activities for 1997 are summarized

  7. Integral Fast Reactor Program

    International Nuclear Information System (INIS)

    This report summarizes highlights of the technical progress made in the Integral Fast Reactor (IFR) Program in FY 1992. Technical accomplishments are presented in the following areas of the IFR technology development activities: (1) metal fuel performance, (2) pyroprocess development, (3) safety experiments and analyses, (4) core design development, (5) fuel cycle demonstration, and (6) LMR technology R ampersand D

  8. Nuclear reactor building

    Science.gov (United States)

    Gou, Perng-Fei; Townsend, Harold E.; Barbanti, Giancarlo

    1994-01-01

    A reactor building for enclosing a nuclear reactor includes a containment vessel having a wetwell disposed therein. The wetwell includes inner and outer walls, a floor, and a roof defining a wetwell pool and a suppression chamber disposed thereabove. The wetwell and containment vessel define a drywell surrounding the reactor. A plurality of vents are disposed in the wetwell pool in flow communication with the drywell for channeling into the wetwell pool steam released in the drywell from the reactor during a LOCA for example, for condensing the steam. A shell is disposed inside the wetwell and extends into the wetwell pool to define a dry gap devoid of wetwell water and disposed in flow communication with the suppression chamber. In a preferred embodiment, the wetwell roof is in the form of a slab disposed on spaced apart support beams which define therebetween an auxiliary chamber. The dry gap, and additionally the auxiliary chamber, provide increased volume to the suppression chamber for improving pressure margin.

  9. Studies on reactor physics

    International Nuclear Information System (INIS)

    Most of the peaceful applications of atomic energy are inherently dependent on advances in the science and technology of nuclear reactors, and aspects of this development are part of a major programme of the International Atomic Energy Agency. The most useful role that the Agency can play is as a co-ordinating body or central forum where the trends can be reviewed and the results assessed. Some of the basic studies are carried out by members of the Agency's own scientific staff. The Agency also convenes groups of experts from different countries to examine a particular problem in detail and make any necessary recommendations. Some of the important subjects are discussed at international scientific meetings held by the Agency. One of the subjects covered by such studies is the physics of nuclear reactors and a specific topic recently discussed was Codes for Reactor Computations, on which a seminar was held in Vienna in April this year. Another The members of the Panel described the development of heavy water reactors, the equipment and methods of research currently used, and plans for further development in their respective countries meeting of Panel of Experts on Heavy Water Lattices was held in Vienna in August 1959

  10. Nuclear power reactor physics

    International Nuclear Information System (INIS)

    The purpose of this book is to explain the physical working conditions of nuclear reactors for the benefit of non-specialized engineers and engineering students. One of the leading ideas of this course is to distinguish between two fundamentally different concepts: - a science which could be called neutrodynamics (as distinct from neutron physics which covers the knowledge of the neutron considered as an elementary particle and the study of its interactions with nuclei); the aim of this science is to study the interaction of the neutron gas with real material media; the introduction will however be restricted to its simplified expression, the theory and equation of diffusion; - a special application: reactor physics, which is introduced when the diffusing and absorbing material medium is also multiplying. For this reason the chapter on fission is used to introduce this section. In practice the section on reactor physics is much longer than that devoted to neutrodynamics and it is developed in what seemed to be the most relevant direction: nuclear power reactors. Every effort was made to meet the following three requirements: to define the physical bases of neutron interaction with different materials, to give a correct mathematical treatment within the limit of necessary simplifying hypotheses clearly explained; to propose, whenever possible, numerical applications in order to fix orders of magnitude

  11. Cermet fuel reactors

    Energy Technology Data Exchange (ETDEWEB)

    Cowan, C.L.; Palmer, R.S.; Van Hoomissen, J.E.; Bhattacharyya, S.K.; Barner, J.O.

    1987-09-01

    Cermet fueled nuclear reactors are attractive candidates for high performance space power systems. The cermet fuel consists of tungsten-urania hexagonal fuel blocks characterized by high strength at elevated temperatures, a high thermal conductivity and resultant high thermal shock resistance. Key features of the cermet fueled reactor design are (1) the ability to achieve very high coolant exit temperatures, and (2) thermal shock resistance during rapid power changes, and (3) two barriers to fission product release - the cermet matrix and the fuel element cladding. Additionally, thre is a potential for achieving a long operating life because of (1) the neutronic insensitivity of the fast-spectrum core to the buildup of fission products and (2) the utilization of a high strength refractory metal matrix and structural materials. These materials also provide resistance against compression forces that potentially might compact and/or reconfigure the core. In addition, the neutronic properties of the refractory materials assure that the reactor remains substantially subcritical under conditions of water immersion. It is concluded that cermet fueled reactors can be utilized to meet the power requirements for a broad range of advanced space applications. 4 refs., 4 figs., 3 tabs.

  12. Cermet fuel reactors

    International Nuclear Information System (INIS)

    Cermet fueled nuclear reactors are attractive candidates for high performance space power systems. The cermet fuel consists of tungsten-urania hexagonal fuel blocks characterized by high strength at elevated temperatures, a high thermal conductivity and resultant high thermal shock resistance. Key features of the cermet fueled reactor design are (1) the ability to achieve very high coolant exit temperatures, and (2) thermal shock resistance during rapid power changes, and (3) two barriers to fission product release - the cermet matrix and the fuel element cladding. Additionally, thre is a potential for achieving a long operating life because of (1) the neutronic insensitivity of the fast-spectrum core to the buildup of fission products and (2) the utilization of a high strength refractory metal matrix and structural materials. These materials also provide resistance against compression forces that potentially might compact and/or reconfigure the core. In addition, the neutronic properties of the refractory materials assure that the reactor remains substantially subcritical under conditions of water immersion. It is concluded that cermet fueled reactors can be utilized to meet the power requirements for a broad range of advanced space applications. 4 refs., 4 figs., 3 tabs

  13. The Chernobyl reactor accident

    International Nuclear Information System (INIS)

    The documentation abstracted contains a complete survey of the broadcasts transmitted by the Russian wire service of the Deutsche Welle radio station between April 28 and Mai 15, 1986 on the occasion of the Chernobyl reactor accident. Access is given to extracts of the remarkable eastern and western echoes on the broadcasts of the Deutsche Welle. (HP)

  14. SRP reactor safety evolution

    International Nuclear Information System (INIS)

    The Savannah River Plant reactors have operated for over 100 reactor years without an incident of significant consequence to on or off-site personnel. The reactor safety posture incorporates a conservative, failure-tolerant design; extensive administrative controls carried out through detailed operating and emergency written procedures; and multiple engineered safety systems backed by comprehensive safety analyses, adapting through the years as operating experience, changes in reactor operational modes, equipment modernization, and experience in the nuclear power industry suggested. Independent technical reviews and audits as well as a strong organizational structure also contribute to the defense-in-depth safety posture. A complete review of safety history would discuss all of the above contributors and the interplay of roles. This report, however, is limited to evolution of the engineered safety features and some of the supporting analyses. The discussion of safety history is divided into finite periods of operating history for preservation of historical perspective and ease of understanding by the reader. Programs in progress are also included. The accident at Three Mile Island was assessed for its safety implications to SRP operation. Resulting recommendations and their current status are discussed separately at the end of the report. 16 refs., 3 figs

  15. Fusion reactor materials

    International Nuclear Information System (INIS)

    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

  16. 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.

  17. Department of reactor technology

    International Nuclear Information System (INIS)

    The activities of the Department of Reactor Technology at Risoe during 1980 are described. The work is presented in three chapters: General Information on the Department, Summary of the Department's Development during 1980, and Activities of the Department. Lists of staff, publications, computer programs, and test facilities are included. (author)

  18. The AP1000 reactor

    International Nuclear Information System (INIS)

    The design of the AP1000 reactor began 20 years ago when Westinghouse launched the AP600 reactor project. In fact by re-assessing AP600's safety margins Westinghouse realized that the its power output could be raised without putting at risk its safety standard. The AP1000 was born, it yields 1100 MWe. The main AP1000's design features is its passive safety (particularly after the Fukushima accident) and its modularity. The passive safety of the AP1000 implies: -) no humane intervention needed for 72 hours at least after the incident; -) no necessity for redundant complex safety systems. The modularity means that the plant, the reactor and other buildings are constructed from a choice of 300 modular units. These units can be built off-site and fit together on site. The modularity allows more construction activities to be led simultaneously and more chances to cope with the construction schedule. The NRC has approved the operation license for 30 years of the first AP1000 being built in the Usa (Vogtle plant in Georgia). 4 AP1000 are being built in China (Sanmen and Haiyang sites) and 6 others are planned in the Usa. Westinghouse is convinced that the AP1000's passive safety makes it more attractive. Let us not forget that Westinghouse was at the origin of the concept of pressurized water reactors, an idea adopted for half the nuclear power stations in the world and for all the plants now active in France. (A.C.)

  19. Fast reactor programme

    International Nuclear Information System (INIS)

    This progress report summarises the fast reactor research carried out at the Netherlands Energy Research Centre during the year 1981. The neutron and fission product cross sections of various isotopes have been evaluated. In the fuel performance programme, some preliminary results are given and irradiation facilities described. Creep experiments on various stainless steel components are reported

  20. Nuclear rocket engine reactor

    Energy Technology Data Exchange (ETDEWEB)

    Lanin, Anatoly

    2013-07-01

    Covers a new technology of nuclear reactors and the related materials aspects. Integrates physics, materials science and engineering Serves as a basic book for nuclear engineers and nuclear physicists. 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.

  1. 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.

  2. 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.

  3. Operating reactors licensing actions summary

    International Nuclear Information System (INIS)

    The operating reactors licensing actions summary is designed to provide the management of the Nuclear Regulatory Commission (NRC) with an overview of licensing actions dealing with operating power and nonpower reactors. These reports utilize data collected from the Division of Licensing in the Office of Nuclear Reactor Regulation and are prepared by the Office of Management and Program Analysis

  4. Fast reactors: potential for power

    International Nuclear Information System (INIS)

    The subject is discussed as follows: basic facts about conventional and fast reactors; uranium economy; plutonium and fast reactors; cooling systems; sodium coolant; safety engineering; handling and recycling plutonium; safeguards; development of fast reactors in Britain and abroad; future progress. (U.K.)

  5. Reactor physics problems on HCPWR

    International Nuclear Information System (INIS)

    Reactor physics problems on high conversion pressurized water reactors (HCPWRs) are discussed. Described in this report are outline of the HCPWR, expected accuracy for the various reactor physical qualities, and method for K-effective calculation in the resonance energy area. And requested further research problems are shown. The target value of the conversion ratio are also discussed. (author)

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

    Science.gov (United States)

    Mella, R.; Wenman, M. R.

    2013-06-01

    Thermo-mechanical contributions to pellet-clad interaction (PCI) in advanced gas-cooled reactors (AGRs) are modelled in the ABAQUS finite element (FE) code. User supplied sub-routines permit the modelling of the non-linear behaviour of AGR fuel through life. Through utilisation of ABAQUS's well-developed pre- and post-processing ability, the behaviour of the axially constrained steel clad fuel was modelled. The 2D axisymmetric model includes thermo-mechanical behaviour of the fuel with time and condition dependent material properties. Pellet cladding gap dynamics and thermal behaviour are also modelled. The model treats heat up as a fully coupled temperature-displacement study. Dwell time and direct power cycling was applied to model the impact of online refuelling, a key feature of the AGR. The model includes the visco-plastic behaviour of the fuel under the stress and irradiation conditions within an AGR core and a non-linear heat transfer model. A multiscale fission gas release model is applied to compute pin pressure; this model is coupled to the PCI gap model through an explicit fission gas inventory code. Whole pin, whole life, models are able to show the impact of the fuel on all segments of cladding including weld end caps and cladding pellet locking mechanisms (unique to AGR fuel). The development of this model in a commercial FE package shows that the development of a potentially verified and future-proof fuel performance code can be created and used. The usability of a FE based fuel performance code would be an enhancement over past codes. Pre- and post-processors have lowered the entry barrier for the development of a fuel performance model to permit the ability to model complicated systems. Typical runtimes for a 5 year axisymmetric model takes less than one hour on a single core workstation. The current model has implemented: Non-linear fuel thermal behaviour, including a complex description of heat flow in the fuel. Coupled with a variety of

  7. Vantagem comparativa dinâmica e crescimento numa economia com dois setores: agrícola e industrial

    Directory of Open Access Journals (Sweden)

    Emerson Marinho

    2007-12-01

    Full Text Available Este artigo analisa os efeitos dos ganhos de produtividade na agricultura sobre o processo de industrialização e, conseqüentemente, sobre o crescimento de longo prazo da economia. Supõe-se no modelo que a produtividade na agricultura é endógena e que a experiência acumulada na indústria exerça impacto positivo sobre a produtividade agrícola. Uma condição necessária para o declínio do emprego industrial é que, devido à vantagem comparativa na agricultura, a economia do resto do mundo apresente baixa integração agricultura/indústria Mostra-se ainda sob que condições intervenções de política podem reverter o padrão de especialização induzido pela vantagem comparativa inicial e ainda assim obter ganhos de bem estar.This paper analyses the effects of agricultural productivity gains on the industrialization process and on the long run growth rate of the economy. The model allows endogenous gains in agricultural productivity and, besides that, it is assumed that accumulated experience in the manufacture sector exerts a positive impact on agricultural productivity. The model shown that a necessary condition to the decline of industrial employment, due to comparative advantage in agriculture, is that the economy of the rest of world has poor industry/ agriculture integration. Finally, it is also shown that interventionist can reverse specialization induced by initial comparative advantages.

  8. Las técnicas geomáticas aplicadas en la agricultura: El catastro agrícola

    Directory of Open Access Journals (Sweden)

    Dámaso R. Ponvert Delisles

    2012-01-01

    Full Text Available Las técnicas Geomáticas, Geoinformáticas o de Geoinformación, como se prefiera nombrarlas, son un conjunto de tecnologías geoespaciales así como programas informáticos especializados para el análisis de los datos y su representación espacial. Entre las más importantes, destacan la Teledetección, los Sistemas de Información Geográfica (SIG, los Sistemas de Posicionamiento Global (GPS y la Cartografía, así como software para el procesamiento digital y representación CAD entre otros. Hoy en día sería casi imposible gestionar los procesos agrarios sin recurrir al empleo de alguna de estas técnicas. Una de las herramientas cartográficas temáticas fundamentales son los mapas catastrales, definidos como documentos cartográficos que representan los bienes inmuebles de un área agrícola con suficiente detalle espacial para facilitar la gestión a nivel de parcelas, sub-parcelas e incluso a escala intraparcelaria. Precisamente el trabajo tiene como objetivo demostrar la necesidad e importancia del empleo de las herramientas catastrales para lograr una gestión agraria y territorial eficiente. Para ello se hace analiza el avance del catastro como sistema en Cuba, llegando a la concepción contemporánea y se particulariza en los catastros especializados para el sector, mostrando un ejemplo concreto que permite a los directivos y especialistas de las PyMES apreciar sus bondades.

  9. First high temperature safety tests of AGR-1 TRISO fuel with the Fuel Accident Condition Simulator (FACS) furnace

    International Nuclear Information System (INIS)

    Three TRISO fuel compacts from the AGR-1 irradiation experiment were subjected to safety tests at 1600 and 1800 °C for approximately 300 h to evaluate the fission product retention characteristics. Silver behavior was dominated by rapid release of an appreciable fraction of the compact inventory (3—34%) at the beginning of the tests, believed to be from inventory residing in the compact matrix and outer pyrocarbon (OPyC) prior to the safety test. Measurable release of silver from intact particles appears to become apparent only after ~60 h at 1800 °C. The release rate for europium and strontium was nearly constant for 300 h at 1600 °C (reaching maximum values of approximately 2x10-3 and 8x10-4 respectively), and at this temperature the release may be mostly limited to inventory in the compact matrix and OPyC prior to the safety test. The release rate for both elements increased after approximately 120 h at 1800 °C, possibly indicating additional measurable release through the intact particle coatings. Cesium fractional release from particles with intact coatings was <10-6 after 300 h at 1600 °C or 100 h at 1800 °C, but release from the rare particles that experienced SiC failure during the test could be significant. However, Kr release was still very low for 300 h 1600 °C (<2x10-6). At 1800 °C, krypton release increased noticeably after SiC failure, reflecting transport through the intact outer pyrocarbon layer. Nonetheless, the krypton and cesium release fractions remained less than approximately 10-3 after 277 h at 1800 °C.

  10. First high temperature safety tests of AGR-1 TRISO fuel with the Fuel Accident Condition Simulator (FACS) furnace

    Energy Technology Data Exchange (ETDEWEB)

    Demkowicz, Paul A. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Reber, Edward L. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Scates, Dawn M. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Scott, Les [Idaho National Lab. (INL), Idaho Falls, ID (United States); Collin, Blaise P. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-09-01

    Three TRISO fuel compacts from the AGR-1 irradiation experiment were subjected to safety tests at 1600 and 1800 °C for approximately 300 h to evaluate the fission product retention characteristics. Silver behavior was dominated by rapid release of an appreciable fraction of the compact inventory (3–34%) at the beginning of the tests, believed to be from inventory residing in the compact matrix and outer pyrocarbon (OPyC) prior to the safety test. Measurable release of silver from intact particles appears to become apparent only after ~60 h at 1800 °C. The release rate for europium and strontium was nearly constant for 300 h at 1600 °C (reaching maximum values of approximately 2×10⁻³ and 8×10⁻⁴ respectively), and at this temperature the release may be mostly limited to inventory in the compact matrix and OPyC prior to the safety test. The release rate for both elements increased after approximately 120 h at 1800 °C, possibly indicating additional measurable release through the intact particle coatings. Cesium fractional release from particles with intact coatings was <10⁻⁶ after 300 h at 1600 °C or 100 h at 1800 °C, but release from the rare particles that experienced SiC failure during the test could be significant. However, Kr release was still very low for 300 h 1600 °C (<2 × 10⁻⁶). At 1800 °C, krypton release increased noticeably after SiC failure, reflecting transport through the intact outer pyrocarbon layer. Nonetheless, the krypton and cesium release fractions remained less than approximately 10⁻³ after 277 h at 1800 °C.

  11. First high temperature safety tests of AGR-1 TRISO fuel with the Fuel Accident Condition Simulator (FACS) furnace

    Science.gov (United States)

    Demkowicz, Paul A.; Reber, Edward L.; Scates, Dawn M.; Scott, Les; Collin, Blaise P.

    2015-09-01

    Three TRISO fuel compacts from the AGR-1 irradiation experiment were subjected to safety tests at 1600 and 1800 °C for approximately 300 h to evaluate the fission product retention characteristics. Silver behavior was dominated by rapid release of an appreciable fraction of the compact inventory (3-34%) at the beginning of the tests, believed to be from inventory residing in the compact matrix and outer pyrocarbon (OPyC) prior to the safety test. Measurable release of silver from intact particles appears to become apparent only after ∼60 h at 1800 °C. The release rate for europium and strontium was nearly constant for 300 h at 1600 °C (reaching maximum values of approximately 2 × 10-3 and 8 × 10-4 respectively), and at this temperature the release may be mostly limited to inventory in the compact matrix and OPyC prior to the safety test. The release rate for both elements increased after approximately 120 h at 1800 °C, possibly indicating additional measurable release through the intact particle coatings. Cesium fractional release from particles with intact coatings was release from the rare particles that experienced SiC failure during the test could be significant. However, Kr release was still very low for 300 h 1600 °C (release increased noticeably after SiC failure, reflecting transport through the intact outer pyrocarbon layer. Nonetheless, the krypton and cesium release fractions remained less than approximately 10-3 after 277 h at 1800 °C.

  12. 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.

  13. 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.

  14. 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.

  15. Reactor physics activities in Japan

    International Nuclear Information System (INIS)

    This report reviews the research activity in reactor physics field in Japan during July, 1992 - July, 1993. The review was performed in the following fields : nuclear data evaluation, calculational method development, fast reactor physics, thermal reactor physics, advanced core design, fusion reactor neutronics, nuclear criticality safety, shielding, incineration of radioactive nuclear wastes, noise analysis and control and national programs. The main references were taken from journals and reports published during this period. The research committee of reactor physics is responsible for the review work. (author)

  16. Advanced reactor experimental facilities

    International Nuclear Information System (INIS)

    For many years, the NEA has been examining advanced reactor issues and disseminating information of use to regulators, designers and researchers on safety issues and research needed. Following the recommendation of participants at an NEA workshop, a Task Group on Advanced Reactor Experimental Facilities (TAREF) was initiated with the aim of providing an overview of facilities suitable for carrying out the safety research considered necessary for gas-cooled reactors (GCRs) and sodium fast reactors (SFRs), with other reactor systems possibly being considered in a subsequent phase. The TAREF was thus created in 2008 with the following participating countries: Canada, the Czech Republic, Finland, France, Germany, Hungary, Italy, Japan, Korea and the United States. In a second stage, India provided valuable information on its experimental facilities related to SFR safety research. The study method adopted entailed first identifying high-priority safety issues that require research and then categorizing the available facilities in terms of their ability to address the safety issues. For each of the technical areas, the task members agreed on a set of safety issues requiring research and established a ranking with regard to safety relevance (high, medium, low) and the status of knowledge based on the following scale relative to full knowledge: high (100%-75%), medium (75 - 25%) and low (25-0%). Only the issues identified as being of high safety relevance and for which the state of knowledge is low or medium were included in the discussion, as these issues would likely warrant further study. For each of the safety issues, the TAREF members identified appropriate facilities, providing relevant information such as operating conditions (in- or out-of reactor), operating range, description of the test section, type of testing, instrumentation, current status and availability, and uniqueness. Based on the information collected, the task members assessed prospects and priorities

  17. Capítulo 5. Instituciones que Podrían Cooperar en los Programas de Investigación de Economía de Producción Agrícola.

    Directory of Open Access Journals (Sweden)

    Beltrán G. Gregorio

    1953-09-01

    Full Text Available Los distintos gobernantes del país siempre han demostrado interés por la agricultura y buena prueba de ello es la copiosa legislación existente, gran parte de la cual nunca se ha llevado a efecto. Poco antes de 1930 se le dio un impulso a la política agrícola al comenzar a fomentar la agricultura por medio de instituciones oficiales y semi-oficiales. Hoy día hay tal vez una excesiva proliferación de instituciones, a tiempo que la estructura agrícola está desorganizada por cuanto hay una confusión de funciones entre ellas. Esto está en desacuerdo con las tendencias modernas de fomento agrícola. Se mencionan las instituciones más importantes dedicadas al fomento de la agricultura que se catalogan en seis diferentes grupos: Institutos Oficiales, Institutos Semi-oficiales, Instituciones Departamentales y Municipales, Cooperativas Agrícolas, Instituciones privadas, Monopolios de Productos Agrícolas, entre otros.

  18. Reactor simulator development. Workshop material

    International Nuclear Information System (INIS)

    The International Atomic Energy Agency (IAEA) has established a programme in nuclear reactor simulation computer programs to assist its Member States in education and training. The objective is to provide, for a variety of advanced reactor types, insight and practice in reactor operational characteristics and their response to perturbations and accident situations. To achieve this, the IAEA arranges for the supply or development of simulation programs and training material, sponsors training courses and workshops, and distributes documentation and computer programs. This publication consists of course material for workshops on development of such reactor simulators. Participants in the workshops are provided with instruction and practice in the development of reactor simulation computer codes using a model development system that assembles integrated codes from a selection of pre-programmed and tested sub-components. This provides insight and understanding into the construction and assumptions of the codes that model the design and operational characteristics of various power reactor systems. The main objective is to demonstrate simple nuclear reactor dynamics with hands-on simulation experience. Using one of the modular development systems, CASSIMtm , a simple point kinetic reactor model is developed, followed by a model that simulates the Xenon/Iodine concentration on changes in reactor power. Lastly, an absorber and adjuster control rod, and a liquid zone model are developed to control reactivity. The built model is used to demonstrate reactor behavior in sub-critical, critical and supercritical states, and to observe the impact of malfunctions of various reactivity control mechanisms on reactor dynamics. Using a PHWR simulator, participants practice typical procedures for a reactor startup and approach to criticality. This workshop material consists of an introduction to systems used for developing reactor simulators, an overview of the dynamic simulation

  19. Reactor water spontaneous circulation structure in reactor pressure vessel

    International Nuclear Information System (INIS)

    The gap between the inner wall of a reactor pressure vessel of a BWR type reactor and a reactor core shroud forms a down comer in which reactor water flows downwardly. A feedwater jacket to which feedwater at low temperature is supplied is disposed at the outer circumference of the pressure vessel just below a gas/water separator. The reactor water at the outer circumferential portion just below the air/water separator is cooled by the feedwater jacket, and the feedwater after cooling is supplied to the feedwater entrance disposed below the feedwater jacket by way of a feedwater introduction line to supply the feedwater to the lower portion of the down comer. This can cool the reactor water in the down comer to increase the reactor water density in the down comer thereby forming strong downward flows and promote the recycling of the reactor water as a whole. With such procedures, the reactor water can be recycled stably only by the difference of the specific gravity of the reactor water without using an internal pump. In addition, the increase of the height of the pressure vessel can be suppressed. (I.N.)

  20. PRAPRAG: software para planejamento racional de máquinas agrícolas PRAPRAG: software for rational planning of agricultural machines

    Directory of Open Access Journals (Sweden)

    Erivelto Mercante

    2010-04-01

    Full Text Available O software PRAPRAG é uma ferramenta de escolha de máquinas e implementos agrícolas que apresentam o menor custo por área ou por quantidade produzida, bem como, faz o planejamento de aquisição das máquinas para a propriedade agrícola, do ponto de vista técnico e econômico. Foi utilizada a linguagem de programação Borland Delphi 3.0 e, a partir de prospectos das máquinas e implementos, criou-se um banco de dados onde o usuário pode cadastrar e modificar suas características de uso. O software mostrou-se uma ferramenta útil e uso amigável. O software proporciona maior rapidez, segurança e confiabilidade ao processo produtivo e econômico das propriedades, na seleção e aquisição de conjuntos mecanizados agrícolas, e na determinação de custos com a mão de obra utilizada.The software PRAPRAG is a tool used for choosing agricultural machines and implements that present the lowest cost per area or produced amount, as well as, to it makes the machines acquisition planning for the agricultural property, from both technical and economical points of view. It was used the programming language Borland Delphi 3.0. From the machine and implement handouts, it was created a database where the user can register and modify their characteristics of use. The software showed to be a useful and friendly tool. The software provides high speed, safety and reliability for the productive and economical process of the properties, at the selection and acquisition of agricultural systems, as well as for the determination of costs with the used labor.