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Sample records for burnup extension

  1. Performance limitations for PWR fuel burnup extensions and high burnup complex loading patterns; Esquemas de recarga de combustible de alto quemado y limitaciones asociadas

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    Ahnert, C.; Aragones, J. M.; Cabellos, O.; Garcia Herranz, N. [Universidad Politecnica de Madrid (Spain)

    2000-07-01

    The analysis, design and on-line surveillance of pressurized water reactors require extensive and detailed 3D core calculations. The development and the improvement of codes are required due to the increasing heterogeneity in PWR (new type of fuel assemblies, complex loading patterns and safety and reliability requirements of nuclear reactor operation). The SEANAP system has been extensively validated and this system has been used to analyze high burnup fuel specifications and several types of long cycles. Some Programs (with Spanish participation) have been developed to study limitations for fuel burnup extensions: Robust Fuel Program, Segmented Rods Program and gain regulatory acceptance of fuel design and operation to higher burnup levels. (Author)

  2. MOX fuel characterization for burnup credit application: Extension of nondestructive method qualified for LEU fuels

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    Riffard, C.; Vidal, J.M. [Commissariat a l' Energie Atomique CEA/DEN/CAD, Building 230 Centre d tudes de Cadarache, 13108 St. Paul Lez Durance (France); Toubon, H. [COGEMA, 78 141 Velizy cedex (France); Pelletter, S. [Canberra-Eurisys, 78067 St. Quentin en Yvelines cedex (France); Batifol, M. [COGEMA La Hague, 50444 Beaumont Hague cedex (France)

    2006-07-01

    Before the reprocessing of low-enriched uranium (LEU) fuels at La. Hague plant, the assemblies are characterized with a nondestructive assay based on neutron emission (NE) and gamma-ray emission combined with the CESAR depletion code, giving the burnup (BU) with a good accuracy ({+-} 5% within a batch of fuels from one of COGEMA-La Hague's clients). The measurements confirm the hypothesis of the safety-criticality analysis of the process, in the context of the BU credit allowance. There is a need to extend the allowance of the reprocessing plants to the case of more highly enriched LEU fuels and to the case of mixed-oxide (MOX) fuels. The aim is to propose an upgraded method, valid for both LEU and MOX fuels, giving the average BU with an uncertainty lower than {+-} 15% for MOX fuels (without any modification of the current acceptance criteria for UO{sub 2} fuel, i.e. {+-} 15%), with a complementary module checking the operator data using the gamma-ray emission and the CESAR depletion code. In particular, the NE was interpreted with depletion calculations in the case of MOX fuels, which is the principal aim of this paper. This allows the BU determination of MOX fuels, which has been qualified during a measurement campaign in La Hague with 20 MOX assemblies. The mean BU of pressurized water reactor MOX assemblies has been determined for the first time with a maximum discrepancy of {+-} 5% compared to the declared value. (authors)

  3. Fuel burnup measurements in FFTF

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    Rawlins, J.A.; Wootan, D.W.; Dobbin, K.D.

    1984-08-01

    Fuel burnup and isotopic fission rates were measured in FFTF during acceptance testing in an 8.6 day full power irradiation. Results were compared with three-dimensional diffusion theory calculations based on ENDF/B-V cross sections. A bias of about 3% exists between burnup and fission rate data, although measured axial and radial profiles are in good agreement. The calculated and measured radial power distributions are in disagreement by 6 to 10% from core center to the outer row of fuel. At core center, calculation/experiment (C/E) for isotopic fission rates is generally 1.01 while C/E for burnup is 1.04. Overall measurement uncertainties are 3% and 2% for fission rate and burnup experiments, respectively. Application of the results to a long-range goal of calculating burnup to 1% accuracy is discussed.

  4. Burnup Credit of Erbia Super-High-Burnup Fuel

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    Sugimura, Naoki; Imamura, Michitaka; Mori, Masaaki [Nuclear Engineering, Ltd., Osaka (Japan); Yamasaki, Masatoshi [Nuclear Fuel Industries, Ltd., Osaka (Japan)

    2008-07-01

    Based on the concept of the Erbia bearing Super High-Burnup (Er-SHB) fuel, the initial erbia contents to guarantee the lower reactivity than that of the conventional 5.0 wt% enriched UO{sub 2} fuels during burnup and cooling are studied. According to the results, the feasibility of the commercial PWR cores using Er-SHB fuels is verified. As the results, it is verified that the long life core operation using Er-SHB fuel are feasible and approximately 20% of feed fuel assemblies can be saved by using Er-SHB fuel. (authors)

  5. Detailed description and user`s manual of high burnup fuel analysis code EXBURN-I

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

    1997-11-01

    EXBURN-I has been developed for the analysis of LWR high burnup fuel behavior in normal operation and power transient conditions. In the high burnup region, phenomena occur which are different in quality from those expected for the extension of behaviors in the mid-burnup region. To analyze these phenomena, EXBURN-I has been formed by the incorporation of such new models as pellet thermal conductivity change, burnup-dependent FP gas release rate, and cladding oxide layer growth to the basic structure of low- and mid-burnup fuel analysis code FEMAXI-IV. The present report describes in detail the whole structure of the code, models, and materials properties. Also, it includes a detailed input manual and sample output, etc. (author). 55 refs.

  6. French investigations of high burnup effect on LOCA thermomecanical behavior. Part two. Oxidation and quenching experiments under simulated LOCA conditions with high burnup clad material

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    GrandJean, C. [IPSN, Cadarache (France); Cauvin, R.; Lebuffe, C. [EDF/SCMI, Chinon (France)] [and others

    1997-01-01

    In the frame of the high burnup fuel studies to support a possible extension of the current discharge burnup limit, experimental programs have been undertaken, jointly by EDF and IPSN in order to study the thermal-shock behavior of high burnup fuel claddings under typical LOCA conditions. The TAGUS program used unirradiated cladding samples, bare or bearing a pre-corrosion state simulating the end-of-life state of high burnup fuel claddings: the TAGCIR program used actually irradiated cladding samples taken from high burnup rods irradiated over 5 cycles in a commercial EDF PWR and having reached a rod burnup close to 60 GWd/tU. The thermal-shock failure tests consisted in oxidizing the cladding samples under steam flow, on both inner and outer faces or on the outer face alone, and subjecting them to a final water quench. The heating was provided by an inductive furnace the power of which being regulated through monitoring of the sample surface temperature with use of a single-wave optical pyrometer. Analysis of the irradiated tests (TAGCIR series) evidenced an increased oxidation rate as compared to similar tests on unirradiated samples. Results of the quenching tests series on unirradiated and irradiated samples are plotted under the usual presentation of failure maps relative to the oxidation parameters ECR (equivalent cladding reacted) or e{sub {beta}} (thickness of the remaining beta phase layer) as a function of the oxidation temperature. Comparison of the failure limits for irradiated specimens to those for unirradiated specimens indicates a lower brittleness under two side oxidation and possibly the opposite under one-side oxidation. The tentative analysis of the oxidation and quenching tests results on irradiated samples reveals the important role played by the hydrogen charged during in-reactor corrosion on the oxidation kinetics and the failure bearing capability of the cladding under LOCA transient conditions.

  7. Technical Data to Justify Full Burnup Credit in Criticality Safety Licensing Analysis

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    Enercon Services, Inc.

    2011-03-14

    Enercon Services, Inc. (ENERCON) was requested under Task Order No.2 to identify scientific and technical data needed to benchmark and justify Full Burnup Credit, which adds 16 fission products and 4 minor actinides1 to Actinide-Only burnup credit. The historical perspective for Full Burnup Credit is discussed, and interviews of organizations participating in burnup credit activities are summarized as a basis for identifying additional data needs and making recommendation. Input from burnup credit participants representing two segments of the commercial nuclear industry is provided. First, the Electric Power Research Institute (EPRI) has been very active in the development of Full Burnup Credit, representing the interests of nuclear utilities in achieving capacity gains for storage and transport casks. EPRI and its utility customers are interested in a swift resolution of the validation issues that are delaying the implementation of Full Burnup Credit [EPRI 2010b]. Second, used nuclear fuel storage and transportation Cask Vendors favor improving burnup credit beyond Actinide-Only burnup credit, although their discussion of specific burnup credit achievements and data needs was limited citing business sensitive and technical proprietary concerns. While Cask Vendor proprietary items are not specifically identified in this report, the needs of all nuclear industry participants are reflected in the conclusions and recommendations of this report. In addition, Oak Ridge National Laboratory (ORNL) and Sandia National Laboratory (SNL) were interviewed for their input into additional data needs to achieve Full Burnup Credit. ORNL was very open to discussions of Full Burnup Credit, with several telecoms and a visit by ENERCON to ORNL. For many years, ORNL has provided extensive support to the NRC regarding burnup credit in all of its forms. Discussions with ORNL focused on potential resolutions to the validation issues for the use of fission products. SNL was helpful in

  8. Alloy development for high burnup cladding (PWR)

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    Hahn, R. [Kraftwerk Union AG, Mulheim (Germany); Jeong, Y.H.; Baek, K.H.; Kim, S.J.; Choi, B.K.; Kim, J.M. [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1999-04-01

    An overview on current alloy development for high burnup PWR fuel cladding is given. It is mainly based on literature data. First, the reasons for an increase of the current mean discharge burnup from 35 MWd / kg(U) to 70 MWd / kg(U) are outlined. From the material data, it is shown that a batch average burnup of 60-70 MWd / kg(U), as aimed by many fuel vendors, can not be achieved with stand (=ASTM-) Zry-4 cladding tubes without violating accepted design criteria. Specifically criteria which limit maximum oxide scale thickness and maximum hydrogen content, and to a less degree, maximum creep and growth rate, can not be achieved. The development potential of standard Zry-4 is shown. Even when taking advantage of this potential, it is shown that an 'improved' Zry-4 is reaching its limits when it achieves the target burnup. The behavior of some Zr alloys outside the ASTM range is shown, and the advantages and disadvantages of the 3 alloy groups (ZrSn+transition metals, ZrNb, ZrSnNb+transition metals) which are currently considered to have the development potential for high burnup cladding materials are depicted. Finally, conclusions are drawn. (author). 14 refs., 11 tabs., 82 figs.

  9. Effect of Control Blade History, and Axial Coolant Density and Burnup Profiles on BWR Burnup Credit

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    Marshall, William BJ J [ORNL

    2016-01-01

    A technical basis for peak reactivity boiling water reactor (BWR) burnup credit (BUC) methods was recently generated, and the technical basis for extended BWR BUC is now being developed. In this paper, a number of effects related to extended BWR BUC are analyzed, including three major operational effects in BWRs: the coolant density axial distribution, the use of control blades during operation, and the axial burnup profile. Specifically, uniform axial moderator density profiles are analyzed and compared to previous results and an additional temporal fidelity study combing moderator density profiles for three different fuel assemblies is presented. Realistic control blade histories and cask criticality results are compared to previously generated constructed control blade histories. Finally, a preliminary study of the axial burnup profile is provided.

  10. Investigation of burnup credit allowance in the criticality safety evaluation of spent fuel casks

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    Lake, W.H. (USDOE, Washington, DC (USA)); Sanders, T.L. (Sandia National Labs., Albuquerque, NM (USA)); Parks, C.V. (Oak Ridge National Lab., TN (USA))

    1990-01-01

    This presentation discusses work in progress on criticality analysis verification for designs which take account of the burnup and age of transported fuel. The work includes verification of cross section data, correlation with experiments, proper extension of the methods into regimes not covered by experiments, establishing adequate reactivity margins, and complete documentation of the project. Recommendations for safe operational procedures are included, as well as a discussion of the economic and safety benefits of such designs.

  11. The burnup dependence of light water reactor spent fuel oxidation

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    Hanson, B.D.

    1998-07-01

    Over the temperature range of interest for dry storage or for placement of spent fuel in a permanent repository under the conditions now being considered, UO{sub 2} is thermodynamically unstable with respect to oxidation to higher oxides. The multiple valence states of uranium allow for the accommodation of interstitial oxygen atoms in the fuel matrix. A variety of stoichiometric and nonstoichiometric phases is therefore possible as the fuel oxidizers from UO{sub 2} to higher oxides. The oxidation of UO{sub 2} has been studied extensively for over 40 years. It has been shown that spent fuel and unirradiated UO{sub 2} oxidize via different mechanisms and at different rates. The oxidation of LWR spent fuel from UO{sub 2} to UO{sub 2.4} was studied previously and is reasonably well understood. The study presented here was initiated to determine the mechanism and rate of oxidation from UO{sub 2.4} to higher oxides. During the early stages of this work, a large variability in the oxidation behavior of samples oxidized under nearly identical conditions was found. Based on previous work on the effect of dopants on UO{sub 2} oxidation and this initial variability, it was hypothesized that the substitution of fission product and actinide impurities for uranium atoms in the spent fuel matrix was the cause of the variable oxidation behavior. Since the impurity concentration is roughly proportional to the burnup of a specimen, the oxidation behavior of spent fuel was expected to be a function of both temperature and burnup. This report (1) summarizes the previous oxidation work for both unirradiated UO{sub 2} and spent fuel (Section 2.2) and presents the theoretical basis for the burnup (i.e., impurity concentration) dependence of the rate of oxidation (Sections 2.3, 2.4, and 2.5), (2) describes the experimental approach (Section 3) and results (Section 4) for the current oxidation tests on spent fuel, and (3) establishes a simple model to determine the activation energies

  12. Investigation and basic evaluation for ultra-high burnup fuel cladding material

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    Ioka, Ikuo; Nagase, Fumihisa; Futakawa, Masatoshi; Kiuchi, Kiyoshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Suga, Masataka [Kokan Keisoku Co., Kawasaki, Kanagawa (Japan)

    2001-03-01

    In ultra-high burnup of the power reactor, it is an essential problem to develop the cladding with excellent durability. First, development history and approach of the safety assessment of Zircaloy for the high burnup fuel were summarized in the report. Second, the basic evaluation and investigation were carried out on the material with high practicability in order to select the candidate materials for the ultra-high burnup fuel. In addition, the basic research on modification technology of the cladding surface was carried out from the viewpoint of the addition of safety margin as a cladding. From the development history of the zirconium alloy including the Zircaloy, it is hard to estimate the results of in-pile test from those of the conventional corrosion test (out-pile test). Therefore, the development of the new testing technology that can simulate the actual environment and the elucidation of the corrosion-controlling factor of the cladding are desired. In cases of RIA (Reactivity Initiated Accident) and LOCA (Loss of Coolant Accident), it seems that the loss of ductility in zirconium alloys under heavy irradiation and boiling of high temperature water restricts the extension of fuel burnup. From preliminary evaluation on the high corrosion-resistance materials (austenitic stainless steel, iron or nickel base superalloys, titanium alloy, niobium alloy, vanadium alloy and ferritic stainless steel), stabilized austenitic stainless steels with a capability of future improvement and high-purity niobium alloys with a expectation of the good corrosion resistance were selected as candidate materials of ultra-high burnup cladding. (author)

  13. High Burnup Fuel Performance and Safety Research

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    Bang, Je Keun; Lee, Chan Bok; Kim, Dae Ho (and others)

    2007-03-15

    The worldwide trend of nuclear fuel development is to develop a high burnup and high performance nuclear fuel with high economies and safety. Because the fuel performance evaluation code, INFRA, has a patent, and the superiority for prediction of fuel performance was proven through the IAEA CRP FUMEX-II program, the INFRA code can be utilized with commercial purpose in the industry. The INFRA code was provided and utilized usefully in the universities and relevant institutes domesticallly and it has been used as a reference code in the industry for the development of the intrinsic fuel rod design code.

  14. Effect of Control Blade History, and Axial Coolant Density and Burnup Profiles on BWR Burnup Credit

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    Ade, Brian J [ORNL; Marshall, William BJ J [ORNL; Martinez-Gonzalez, Jesus S [ORNL

    2015-05-01

    Oak Ridge National Laboratory (ORNL) and the US Nuclear Regulatory Commission (NRC) have initiated a multiyear project to investigate the application of burnup credit (BUC) for boiling water reactor (BWR) fuel in storage and transportation systems (often referred to as casks) and spent fuel pools (SFPs). This work is divided into two main phases. The first phase investigated the applicability of peak reactivity methods currently used in SFPs to transportation and storage casks and the validation of reactivity calculations and spent fuel compositions within these methods. The second phase focuses on extending BUC beyond peak reactivity. This paper documents the analysis of the effects of control blade insertion history, and moderator density and burnup axial profiles for extended BWR BUC.

  15. SOURCE OF BURNUP VALUES FOR COMMERCIAL SPENT NUCLEAR FUEL ASSEMBLIES

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    BSC

    2004-12-01

    Waste packages are loaded with commercial spent nuclear fuel (SNF) that satisfies the minimum burnup requirements of a criticality loading curve. The burnup value assigned by the originating nuclear utility to each SNF assembly (assigned burnup) is used to load waste packages in compliance with a criticality loading curve. The burnup provided by a nuclear utility has uncertainties, so conservative calculation methods are used to characterize those uncertainties for incorporation into the criticality loading curves. Procedural safety controls ensure that the correct assembly is loaded into each waste package to prevent a misload that could create a condition affecting the safety margins. Probabilistic analyses show that procedural safety controls can minimize the chance of a misload but can not completely eliminate the possibility. Physical measurements of burnup with instrumentation in the surface facility are not necessary due to the conservative calculation methods used to produce the criticality loading curves. The reactor records assigned burnup of a commercial SNF assembly contains about two percent uncertainty, which is increased to five-percent to ensure conservatism. This five-percent uncertainty is accommodated by adjusting the criticality loading curve. Also, the record keeping methods of nuclear utilities are not uniform and the level of detail required by the NRC has varied over the last several decades. Thus, some SNF assemblies may have assigned burnups that are averages for a batch of assemblies with similar characteristics. Utilities typically have access to more detailed core-follow records that allow the batch average burnup to be changed to an assembly specific burnup. Alternatively, an additional safety margin is incorporated into the criticality loading curve to accommodate SNF assemblies with batch average burnups or greater uncertainties due to the methodology used by the nuclear utility. The utility records provide the assembly identifier

  16. Analysis of Experimental Data for High Burnup PWR Spent Fuel Isotopic Validation - Vandellos II Reactor

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    Ilas, Germina [ORNL; Gauld, Ian C [ORNL

    2011-01-01

    This report is one of the several recent NUREG/CR reports documenting benchmark-quality radiochemical assay data and the use of the data to validate computer code predictions of isotopic composition for spent nuclear fuel, to establish the uncertainty and bias associated with code predictions. The experimental data analyzed in the current report were acquired from a high-burnup fuel program coordinated by Spanish organizations. The measurements included extensive actinide and fission product data of importance to spent fuel safety applications, including burnup credit, decay heat, and radiation source terms. Six unique spent fuel samples from three uranium oxide fuel rods were analyzed. The fuel rods had a 4.5 wt % {sup 235}U initial enrichment and were irradiated in the Vandellos II pressurized water reactor operated in Spain. The burnups of the fuel samples range from 42 to 78 GWd/MTU. The measurements were used to validate the two-dimensional depletion sequence TRITON in the SCALE computer code system.

  17. Conservative approach for PWR MOX Burnup Credit implementation

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    Jutier, Ludyvine; Checiak, Benoit; Raby, Jerome; Aguiar, Luis; Le Bars, Igor [IRSN, Fontenay-aux-Roses (France)

    2008-07-01

    Burnup Credit allows considering the reactivity decrease due to fuel irradiation in criticality studies for the nuclear fuel cycle. Its implementation requires to carefully analyze the validity of the assumption made to: define the axial profile of the burnup, determine the composition of the irradiated fuel and compute the criticality simulation. In the framework of Burnup Credit implementation for PWR mixed oxide fuels (MOX), this paper focus on the determination of a conservative inventory of the irradiated fuel. The studies presented in this paper concern: the influence of irradiation conditions and of the MOX fuel initial composition on the irradiated MOX fuel reactivity. Criticality calculations are also performed for PWR MOX fuel industrial applications in order to get Burnup Credit gain estimations. (authors)

  18. Influence of FIMA burnup on actinides concentrations in PWR reactors

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    Oettingen Mikołaj

    2016-01-01

    Full Text Available In the paper we present the study on the dependence of actinides concentrations in the spent nuclear fuel on FIMA burnup. The concentrations of uranium, plutonium, americium and curium isotopes obtained in numerical simulation are compared with the result of the post irradiation assay of two spent fuel samples. The samples were cut from the fuel rod irradiated during two reactor cycles in the Japanese Ohi-2 Pressurized Water Reactor. The performed comparative analysis assesses the reliability of the developed numerical set-up, especially in terms of the system normalization to the measured FIMA burnup. The numerical simulations were preformed using the burnup and radiation transport mode of the Monte Carlo Continuous Energy Burnup Code – MCB, developed at the Department of Nuclear Energy, Faculty of Energy and Fuels of AGH University of Science and Technology.

  19. A guide introducing burnup credit, preliminary version. Contract research

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    NONE

    2001-07-01

    It is examined to take burnup credit into account for criticality safety control of facility treating spent fuel. This work is a collection of current technical status of predicting isotopic composition and criticality of spent fuel, points to be specially considered for safety evaluation, and current status of legal affairs for the purpose of applying burnup credit to the criticality safety evaluation of the facility treating spent fuel in Japan. (author)

  20. Designing Critical Experiments in Support of Full Burnup Credit

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    Mueller, Don [ORNL; Roberts, Jeremy A [ORNL

    2008-01-01

    Burnup credit is the process of accounting for the negative reactivity due to fuel burnup and generation of parasitic absorbers over fuel assembly lifetime. For years, the fresh fuel assumption was used as a simple bound in criticality work for used fuel storage and transportation. More recently, major actinides have been included [1]. However, even this yields a highly conservative estimate in criticality calculations. Because of the numerous economical benefits including all available negative reactivity (i.e., full burnup credit) could provide [2], it is advantageous to work toward full burnup credit. Unfortunately, comparatively little work has been done to include non-major actinides and other fission products (FP) in burnup credit analyses due in part to insufficient experimental data for validation of codes and nuclear data. The Burnup Credit Criticality Experiment (BUCCX) at Sandia National Laboratory was a set of experiments with {sup 103}Rh that have relevance for burnup credit [3]. This work uses TSUNAMI-3D to investigate and adjust a BUCCX model to match isotope-specific, energy-dependent k{sub eff} sensitivity profiles to those of a representative high-capacity cask model (GBC-32) [4] for each FP of interest. The isotopes considered are {sup 149}Sm, {sup 143}Nd, {sup 103}Rh, {sup 133}Cs, {sup 155}Gd, {sup 152}Sm, {sup 99}Tc, {sup 145}Nd, {sup 153}Eu, {sup 147}Sm, {sup 109}Ag, {sup 95}Mo, {sup 150}Sm, {sup 101}Ru, and {sup 151}Eu. The goal is to understand the biases and bias uncertainties inherent in nuclear data, and ultimately, to apply these in support of full burnup credit.

  1. Analysis of high burnup pressurized water reactor fuel using uranium, plutonium, neodymium, and cesium isotope correlations with burnup

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    Jung Suk Kim

    2015-12-01

    Full Text Available The correlation of the isotopic composition of uranium, plutonium, neodymium, and cesium with the burnup for high burnup pressurized water reactor fuels irradiated in nuclear power reactors has been experimentally investigated. The total burnup was determined by Nd-148 and the fractional 235U burnup was determined by U and Pu mass spectrometric methods. The isotopic compositions of U, Pu, Nd, and Cs after their separation from the irradiated fuel samples were measured using thermal ionization mass spectrometry. The contents of these elements in the irradiated fuel were determined through an isotope dilution mass spectrometric method using 233U, 242Pu, 150Nd, and 133Cs as spikes. The activity ratios of Cs isotopes in the fuel samples were determined using gamma-ray spectrometry. The content of each element and its isotopic compositions in the irradiated fuel were expressed by their correlation with the total and fractional burnup, burnup parameters, and the isotopic compositions of different elements. The results obtained from the experimental methods were compared with those calculated using the ORIGEN-S code.

  2. Effects of Lower Drying-Storage Temperature on the Ductility of High-Burnup PWR Cladding

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    Billone, M. C. [Argonne National Lab. (ANL), Argonne, IL (United States); Burtseva, T. A. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-08-30

    The purpose of this research effort is to determine the effects of canister and/or cask drying and storage on radial hydride precipitation in, and potential embrittlement of, high-burnup (HBU) pressurized water reactor (PWR) cladding alloys during cooling for a range of peak drying-storage temperatures (PCT) and hoop stresses. Extensive precipitation of radial hydrides could lower the failure hoop stresses and strains, relative to limits established for as-irradiated cladding from discharged fuel rods stored in pools, at temperatures below the ductile-to-brittle transition temperature (DBTT).

  3. The interest of burnup increase in a context of recycling

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    Druenne, Hubert [GDF SUEZ-TRACTEBEL, Avenue Ariane 7 - B-1200 Brussels (Belgium)

    2009-06-15

    The current trend is to increase the fuel discharge burnup. In the framework of a recycling policy (closed cycle) higher burnup also affects the quality of the fissile material coming back from the reprocessing. It has the following consequences: - the lower quality of the reprocessed material requires either higher ERU enrichment and/or higher plutonium content in MOX fuel; - should some limits be reached (manufacture limits, maximum {sup 235}U enrichment or Pu content), the energy equivalence could no longer be maintained between recycled fuel assemblies (ERU or MOX) and ENU ones; - in turn, the loss of energy equivalence would request larger feed size, and hence would limit the burnup increase. Consequently, the question is whether an increase in burnup could hamper a recycling policy. In a closed cycle, and considering only the 2. or 3. generation PWR, does the increase in burnup still make it possible to reduce the need for fissile material? Is there an economic optimum? This paper attempts to answer these questions. In conclusions: A. Reprocessing and recycling processes: The present industrial processes technical limits do not hinder reprocessing and recycling of highly burned assemblies (at least in the assumed limit of roughly 65 GWd/t - assembly average). But taking into account the present limitations in terms of initial enrichment, enrichment technology, fuel fabrication and fresh fuel transportation, the additional costs may limit or even over-compensate the benefits resulting from higher discharge burnups. These costs must be known to conclude on the economy of high burnup in a closed cycle policy. B. In-core fuel management: In 18-month cycle, the present 5% enrichment limit is a strong constraint for 'auto-recycling': even with the shortest reprocessing delays as possible, it restricts the achievable batch average discharge burnup to about 56 GWd/t. The economy of high burnup should be analysed in a multi nuclear unit fuel management, with

  4. Advances in Metallic Fuels for High Burnup and Actinide Transmutation

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    Hayes, S. L.; Harp, J. M.; Chichester, H. J. M.; Fielding, R. S.; Mariani, R. D.; Carmack, W. J.

    2016-10-01

    Research and development activities on metallic fuels in the US are focused on their potential use for actinide transmutation in future sodium fast reactors. As part of this application, there is a desire to demonstrate a multifold increase in burnup potential. A number of metallic fuel design innovations are under investigation with a view toward significantly increasing the burnup potential of metallic fuels, since higher discharge burnups equate to lower potential actinide losses during recycle. Promising innovations under investigation include: 1) lowering the fuel smeared density in order to accommodate the additional swelling expected as burnups increase, 2) utilizing an annular fuel geometry for better geometrical stability at low smeared densities, as well as the potential to eliminate the need for a sodium bond, and 3) minor alloy additions to immobilize lanthanide fission products inside the metallic fuel matrix and prevent their transport to the cladding resulting in fuel-cladding chemical interaction. This paper presents results from these efforts to advance metallic fuel technology in support of high burnup and actinide transmutation objectives. Highlights include examples of fabrication of low smeared density annular metallic fuels, experiments to identify alloy additions effective in immobilizing lanthanide fission products, and early postirradiation examinations of annular metallic fuels having low smeared densities and palladium additions for fission product immobilization.

  5. Automated system for determining the burnup of spent nuclear fuel

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    Mokritskii V. A.

    2014-12-01

    Full Text Available The authors analyze their experience in application of semi-conductor detectors and development of a breadboard model of the monitoring system for spent nuclear fuel (SNF. Such system should use CdZnTe-detectors in which one-charging gathering conditions are realized. The proposed technique of real time SNF control during reloading technological operations is based on the obtained research results. Methods for determining the burnup of spent nuclear fuel based on measuring the characteristics of intrinsic radiation are covered in many papers, but those metods do not usually take into account that the nuclear fuel used during the operation has varying degrees of initial enrichment, or a new kind of fuel may be used. Besides, the known methods often do not fit well into the existing technology of fuel loading operations and are not suitable for operational control. Nuclear fuel monitoring (including burnup determination system in this research is based on the measurement of the spectrum of natural gamma-radiation of irradiated fuel assemblies (IFA, as from the point of view of minimizing the time spent, the measurement of IFA gamma spectra directly during fuel loading is optimal. It is the overload time that is regulated rather strictly, and burnup control operations should be coordinated with the schedule of the fuel loading. Therefore, the real time working capacity of the system should be chosen as the basic criterion when constructing the structure of such burnup control systems.

  6. Dependence of control rod worth on fuel burnup

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    Savva, P., E-mail: savvapan@ipta.demokritos.g [NCSR ' DEMOKRITOS' , PoB 60228, 15310 Aghia Paraskevi (Greece); Varvayanni, M., E-mail: melina@ipta.demokritos.g [NCSR ' DEMOKRITOS' , PoB 60228, 15310 Aghia Paraskevi (Greece); Catsaros, N., E-mail: nicos@ipta.demokritos.g [NCSR ' DEMOKRITOS' , PoB 60228, 15310 Aghia Paraskevi (Greece)

    2011-02-15

    Research highlights: Diffusion and MC calculations for rod worth dependence on burnup and Xe in reactors. One-step rod withdrawal/insertion are used for rod worth estimation. The study showed that when Xe is present the rods worth is significantly reduced. Rod worth variation with burnup depends on rod position in core. Rod worth obtained with MC code is higher than that obtained from deterministic. - Abstract: One important parameter in the design and the analysis of a nuclear reactor core is the reactivity worth of the control rods, i.e. their efficiency to absorb excess reactivity. The control rod worth is affected by parameters such as the fuel burnup in the rod vicinity, the Xe concentration in the core, the operational time of the rod and its position in the core. In the present work, two different computational approaches, a deterministic and a stochastic one, were used for the determination of the rods worth dependence on the fuel burnup level and the Xe concentration level in a conceptual, symmetric reactor core, based on the MTR fuel assemblies used in the Greek Research Reactor (GRR-1). For the deterministic approach the neutronics code system composed by the SCALE modules NITAWL and XSDRN and the diffusion code CITATION was used, while for the stochastic one the Monte Carlo code TRIPOLI was applied. The study showed that when Xe is present in the core, the rods worth is significantly reduced, while the rod worth variation with increasing burnup depends on the rods position in the core grid. The rod worth obtained with the use of the Monte Carlo code is higher than the one obtained from the deterministic code.

  7. Burnup calculations using serpent code in accelerator driven thorium reactors

    Energy Technology Data Exchange (ETDEWEB)

    Korkmaz, M.E.; Agar, O. [Karamanoglu Mehmetbey Univ., Karaman (Turkey). Physics Dept.; Yigit, M. [Aksaray Univ. (Turkey). Physics Dept.

    2013-07-15

    In this study, burnup calculations have been performed for a sodium cooled Accelerator Driven Thorium Reactor (ADTR) using the Serpent 1.1.16 Monte Carlo code. The ADTR has been designed for burning minor actinides, mixed {sup 232}Th and mixed {sup 233}U fuels. A solid Pb-Bi spallation target in the center of the core is used and sodium as coolant. The system is designed for a heating power of 2 000 MW and for an operation time of 600 days. For burnup calculations the Advanced Matrix Exponential Method CRAM (Chebyshev Rational Approximation Method) and different nuclear data libraries (ENDF7, JEF2.2, JEFF3.1.1) were used. The effective multiplication factor change from 0.93 to 0.97 for different nuclear data libraries during the reactor operation period. (orig.)

  8. Modelling of fission gas swelling in the high burnup UO{sub 2} fuel

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dae Ho; Lee, Chan Bock; Bang, Je Gun; Jung, Yeon Ho

    1999-06-01

    Discharge burnup of the fuel in LWR has been increased to improve the fuel economy, and currently the high burnup fuel of over 70 MWd/kg U-rod avg. is being developed by the fuel vendors worldwide. At high burnup, thermal / mechanical properties of the fuel is known to change and new phenomenon could arise. This report describes the model development on fission gas swelling in high burnup UO{sub 2} fuel. For the low burnup fuel, swelling only by the solid fission products has been considered in the fuel performance analysis. However, at high burnup fuel, swelling by fission gas bubbles can not be neglected anymore. Therefore, fission gas swelling model which can predictbubble swelling of the high burnup UO{sub 2} fuel during the steady-state and the transient conditions in LWR was developed. Based on the bubble growth model, the empirical fission gas swelling model was developed as function of burnup, time and temperature. The model showed that fuel bubble swelling would be proportional to the burnup by the power of 1.157 and to the time by the power of 0.157. Comparison of the model prediction with the measured fission gas swelling data under the various burnup and temperature conditions showed that the model would predict the measured data reasonably well. (author). 20 refs., 8 tabs., 17 figs.

  9. New burnup calculation of TRIGA IPR-R1 reactor

    Energy Technology Data Exchange (ETDEWEB)

    Meireles, Sincler P. de; Campolina, Daniel de A.M.; Santos, Andre A. Campagnole dos; Menezes, Maria A.B.C.; Mesquita, Amir Z., E-mail: sinclercdtn@hotmail.com.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2015-07-01

    The IPR-R1 TRIGA Mark I research reactor, located at the Nuclear Technology Development Center - CDTN, Belo Horizonte, Brazil, operates since 1960.The reactor is operating for more than fifty years and has a long history of operation. Determining the current composition of the fuel is very important to calculate various parameters. The reactor burnup calculation has been performed before, however, new techniques, methods, software and increase of the processing capacity of the new computers motivates new investigations to be performed. This work presents the evolution of effective multiplication constant and the results of burnup. This new model has a more detailed geometry with the introduction of the new devices, like the control rods and the samarium discs. This increase of materials in the simulation in burnup calculation was very important for results. For these series of simulations a more recently cross section library, ENDF/B-VII, was used. To perform the calculations two Monte Carlo particle transport code were used: Serpent and MCNPX. The results obtained from two codes are presented and compared with previous studies in the literature. (author)

  10. Burnup Credit Approach Used in the Yucca Mountain License Application

    Energy Technology Data Exchange (ETDEWEB)

    Scaglione, John M [ORNL; Wagner, John C [ORNL

    2010-01-01

    The United States Department of Energy has submitted a license application (LA) for construction authorization of a deep geologic repository at Yucca Mountain, Nevada. The license application is currently under review by the United States Nuclear Regulatory Commission (NRC). This paper will describe the methodology and approach used in the LA to address the issue of criticality and the role of burnup credit during the postclosure period. The most significant and effective measures for prevention of criticality in the repository include multiple redundant barriers that act to isolate fissionable material from water (which can act as a moderator, corrosive agent, and transporter of fissile material); inherent geometry of waste package internals and waste forms; presence of fixed neutron absorbers in waste package internals; and fuel burnup for commercial spent nuclear fuel. A probabilistic approach has been used to screen criticality from the total system performance assessment. Within the probabilistic approach, criticality is considered an event, and the total probability of a criticality event occurring within 10,000 years of disposal is calculated and compared against the regulatory criterion. The total probability of criticality includes contributions associated with both internal (within waste packages) and external (external to waste packages) criticality for each of the initiating events that could lead to waste package breach. The occurrence of and conditions necessary for criticality in the repository have been thoroughly evaluated using a comprehensive range of parameter distributions. A simplified design-basis modeling approach has been used to evaluate the probability of criticality by using numerous significant and conservative assumptions. Burnup credit is used only for evaluations of in-package configurations and uses a combination of conservative and bounding modeling approximations to ensure conservatism. This paper will review the NRC regulatory

  11. Models for fuel rod behaviour at high burnup

    Energy Technology Data Exchange (ETDEWEB)

    Jernkvist, Lars O.; Massih, Ali R. [Quantum Technologies AB, Uppsala Science Park, Uppsala (Sweden)

    2004-12-01

    This report deals with release of fission product gases and irradiation-induced restructuring in uranium dioxide nuclear fuel. Waterside corrosion of zirconium alloy clad tubes to light water reactor fuel rods is also discussed. Computational models, suitable for implementation in the FRAPCON-3.2 computer code, are proposed for these potentially life-limiting phenomena. Hence, an integrated model for the calculation or thermal fission gas release by intragranular diffusion, gas trapping in grain boundaries, irradiation-induced re-solution, grain boundary saturation, and grain boundary sweeping in UO{sub 2} fuel, under time varying temperature loads, is formulated. After a brief review of the status of thermal fission gas release modelling, we delineate the governing equations for the aforementioned processes. Grain growth kinetic modelling is briefly reviewed and pertinent data on grain growth of high burnup fuel obtained during power ramps in the Third Risoe Fission Gas Release Project are evaluated. Sample computations are performed, which clearly show the connection between fission gas release and gram growth as a function of time at different isotherms. Models are also proposed for the restructuring of uranium dioxide fuel at high burnup, the so-called rim formation, and its effect on fuel porosity build-up, fuel thermal conductivity and fission gas release. These models are assessed by use of recent experimental data from the High Burnup Rim Project, as well as from post irradiation examinations of high-burnup fuel, irradiated in power reactors. Moreover, models for clad oxide growth and hydrogen pickup in PWRs, applicable to Zircaloy-4, ZIRLO or M5 cladding, are formulated, based on recent in-reactor corrosion data for high-burnup fuel rods. Our evaluation of these data indicates that the oxidation rate of ZIRLO-type materials is about 20% lower than for standard Zircaloy-4 cladding under typical PWR conditions. Likewise, the oxidation rate of M5 seems to be

  12. Corrosion studies with high burnup light water reactor fuel. Release of nuclides into simulated groundwater during accumulated contact time of up to two years

    Energy Technology Data Exchange (ETDEWEB)

    Zwicky, Hans-Urs (Zwicky Consulting GmbH, Remigen (Switzerland)); Low, Jeanett; Ekeroth, Ella (Studsvik Nuclear AB, Nykoeping (Sweden))

    2011-03-15

    pellet surface than the bulk of the pellet in leaching experiments. Thus, formation of oxidising species and radicals by radiolysis is expected to be disproportionately high as well. Therefore, when discussing high burnup fuel dissolution, the effect of the increased radiation field with burnup, as well as of the influence of the smaller grain size and increased porosity at the rim are mentioned as factors which contribute to increased dissolution rates. A third factor, increased fission product and actinide doping with burnup, has been discussed extensively in connection with increased resistance to air oxidation of the fuel. Samples from four different fuel rods, all operated in Pressurised Water Reactors (PWR), are used in the new series of corrosion experiments. They cover a burnup range from 58 to 75 MWd/kgU. The nuclide inventory of all four samples was determined by means of a combination of experimental nuclide analysis and sample specific modelling calculations. More than 40 different nuclides were analysed by isotope dilution analysis using Inductively Coupled Plasma Mass Spectrometry (ICP-MS), as well as other ICP-MS and gamma spectrometric methods. The content of roughly all fission products and actinides was also calculated separately for each sample. The experiments are performed under oxidising conditions in synthetic groundwater at ambient temperature. In order to make results as comparable as possible to those of the Series 11 experiments, the same procedure and the same leachant is used. At least nine consecutive contact periods of one and three weeks and two, three, six and twelve months are planned. The present report covers the first five contact periods up to a cumulative contact time of one year for all four samples and in addition the sixth period up to a cumulative contact time of two years for two of the samples. The samples, kept in position by a platinum wire spiral, are exposed to synthetic groundwater in a Pyrex flask. After the contact

  13. Review of Technical Studies in the United States in Support of Burnup Credit Regulatory Guidance

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, John C [ORNL; Parks, Cecil V [ORNL; Mueller, Don [ORNL; Gauld, Ian C [ORNL

    2010-01-01

    Taking credit for the reduction in reactivity associated with fuel depletion can enable more cost-effective, higher-density storage, transport, disposal, and reprocessing of spent nuclear fuel (SNF) while maintaining sufficient subcritical margin to establish an adequate safety basis. Consequently, there continues to be considerable interest in the United States (U.S.), as well as internationally, in the increased use of burnup credit in SNF operations, particularly related to storage, transport, and disposal of commercial SNF. This interest has motivated numerous technical studies related to the application of burnup credit, both domestically and internationally, as well as the design of SNF storage, transport and disposal systems that rely on burnup credit for maintaining subcriticality. Responding to industry requests and needs, the U.S. Nuclear Regulatory Commission (NRC) initiated a burnup credit research program in 1999, with support from the Oak Ridge National Laboratory (ORNL), to develop regulatory guidance and the supporting technical bases for allowing and expanding the use of burnup credit in pressurized-water reactor SNF storage and transport applications. Although this NRC research program has not been continuous since its inception, considerable progress has been achieved in many key areas in terms of increased understanding of relevant phenomena and issues, availability of relevant information and data, and subsequently updated regulatory guidance for expanded use of burnup credit. This paper reviews technical studies performed by ORNL for the U.S. NRC burnup credit research program. Examples of topics include reactivity effects associated with reactor operating characteristics, fuel assembly characteristics, burnable absorbers, control rods, spatial burnup distributions, cooling time, and assembly misloading; methods and data for validation of isotopic composition predictions; methods and data for validation of criticality calculations; and

  14. Criticality Evaluation of GBC-32 Cask with HBN No.3 Fuels in PWR Burnup Credit

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Do-Yeon; Yoon, Hyoungju; Park, Kwangheon; Hong, Ser Gi [Kyung Hee Univ., Yongin (Korea, Republic of)

    2015-10-15

    An application of burnup credit is able to increase the capacity in casks. In this paper, the criticality evaluation for burnup credit was performed for the GBC-32 cask with the fuel assemblies discharged after HBN No.3 Cycle 6 by SCALE6.1/STARBUCS and MCNP6 with the axial burnup distributions and average discharge burnups evaluated using DeCART and MASTER codes. The criticality evaluation for burnup credit was performed for the GBC-32 cask with the fuel assemblies discharged after HBN No.3 Cycle 6 by STARBUCS and MCNP6 codes with the axial burnup distributions and average discharge burnups evaluated using DeCART and MASTER codes. k{sub eff} values and end effects were calculated for 3 cooling times of 0, 20, and 30 years. From the results calculated in these conditions, the following conclusions are drawn. (1) 12 discharged fuel assemblies for the cooling time of 0 year were not allowed to be stored in the cask because the estimated k{sub eff} values exceeds 0.9146. (2) Most of the discharged fuel assemblies except for 3 discharged fuel assemblies were allowed to be stored for the cooling times of 20 and 30 years. (3) The end effects increased as the cooling time increases, within the maximums of 834.93 pcm for the cooling time of 0 year, 1684.45 pcm for 20 years, and 2178.92 pcm for 30 years.

  15. Mechanical Fatigue Testing of High Burnup Fuel for Transportation Applications

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jy-An John [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Wang, Hong [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-05-01

    This report describes testing designed to determine the ability of high burnup (HBU) (>45 GWd/MTU) spent fuel to maintain its integrity under normal conditions of transportation. An innovative system, Cyclic Integrated Reversible-bending Fatigue Tester (CIRFT), has been developed at Oak Ridge National Laboratory (ORNL) to test and evaluate the mechanical behavior of spent nuclear fuel (SNF) under conditions relevant to storage and transportation. The CIRFT system is composed of a U-frame equipped with load cells for imposing the pure bending loads on the SNF rod test specimen and measuring the in-situ curvature of the fuel rod during bending using a set up with three linear variable differential transformers (LVDTs).

  16. Simulation of triton burn-up in JET plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Loughlin, M.J.; Balet, B.; Jarvis, O.N.; Stubberfield, P.M. [Commission of the European Communities, Abingdon (United Kingdom). JET Joint Undertaking

    1994-07-01

    This paper presents the first triton burn-up calculations for JET plasmas using the transport code TRANSP. Four hot ion H-mode deuterium plasmas are studied. For these discharges, the 2.5 MeV emission rises rapidly and then collapses abruptly. This phenomenon is not fully understood but in each case the collapse phase is associated with a large impurity influx known as the ``carbon bloom``. The peak 14 MeV emission occurs at this time, somewhat later than that of the 2.5 MeV neutron peak. The present results give a clear indication that there are no significant departures from classical slowing down and spatial diffusion for tritons in JET plasmas. (authors). 7 refs., 3 figs., 1 tab.

  17. Manufacturing Data Uncertainties Propagation Method in Burn-Up Problems

    Directory of Open Access Journals (Sweden)

    Thomas Frosio

    2017-01-01

    Full Text Available A nuclear data-based uncertainty propagation methodology is extended to enable propagation of manufacturing/technological data (TD uncertainties in a burn-up calculation problem, taking into account correlation terms between Boltzmann and Bateman terms. The methodology is applied to reactivity and power distributions in a Material Testing Reactor benchmark. Due to the inherent statistical behavior of manufacturing tolerances, Monte Carlo sampling method is used for determining output perturbations on integral quantities. A global sensitivity analysis (GSA is performed for each manufacturing parameter and allows identifying and ranking the influential parameters whose tolerances need to be better controlled. We show that the overall impact of some TD uncertainties, such as uranium enrichment, or fuel plate thickness, on the reactivity is negligible because the different core areas induce compensating effects on the global quantity. However, local quantities, such as power distributions, are strongly impacted by TD uncertainty propagations. For isotopic concentrations, no clear trends appear on the results.

  18. Thermal behavior analysis of PWR fuel during RIA at various fuel burnups using modified theatre code

    Directory of Open Access Journals (Sweden)

    Nawaz Amjad

    2016-01-01

    Full Text Available The fuel irradiation and burnup causes geometrical and dimensional changes in the fuel rod which affects its thermal resistance and ultimately affects the fuel rod behavior during steady-state and transient conditions. The consistent analysis of fuel rod thermal performance is essential for precise evaluation of reactor safety in operational transients and accidents. In this work, analysis of PWR fuel rod thermal performance is carried out under steady-state and transient conditions at different fuel burnups. The analysis is performed by using thermal hydraulic code, THEATRe. The code is modified by adding burnup dependent fuel rod behavior models. The original code uses as-fabricated fuel rod dimensions during steady-state and transient conditions which can be modified to perform more consistent reactor safety analysis. AP1000 reactor is considered as a reference reactor for this analysis. The effect of burnup on steady-state fuel rod parameters has been investigated. For transient analysis, hypothetical reactivity initiated accident was simulated by considering a triangular power pulse of variable pulse height (relative to the full power reactor operating conditions and pulse width at different fuel burnups which corresponds to fresh fuel, low and medium burnup fuels. The effect of power pulse height, pulse width and fuel burnup on fuel rod temperatures has been investigated. The results of reactivity initiated accident analysis show that the fuel failure mechanisms are different for fresh fuel and fuel at different burnup levels. The fuel failure in fresh fuel is expected due to fuel melting as fuel temperature increases with increase in pulse energy (pulse height. However, at relatively higher burnups, the fuel failure is expected due to cladding failure caused by strong pellet clad mechanical interaction, where, the contact pressure increases beyond the cladding yield strength.

  19. Burnup measurements on spent fuel elements of the RP-10 research reactor

    Energy Technology Data Exchange (ETDEWEB)

    Vela Mora, Mariano; Gallardo Padilla, Alberto; Palomino, Jose Luis Castro, E-mail: mvela@ipen.gob.p [Instituto Peruano de Energia Nuclear (IPEN/Peru), Lima (Peru). Grupo de Calculo, Analisis y Seguridad de Reactores; Terremoto, Luis Antonio Albiac, E-mail: laaterre@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    This work describes the measurement, using nondestructive gamma-ray spectroscopy, of the average burnup attained by Material Testing Reactor (MTR) fuel elements irradiated in the RP-10 research reactor. Measurements were performed at the reactor storage pool area using {sup 137}Cs as the only burnup monitor, even for spent fuel elements with cooling times much shorter than two years. The experimental apparatus was previously calibrated in efficiency to obtain absolute average burnup values, which were compared against corresponding ones furnished by reactor physics calculations. The mean deviation between both values amounts to 6%. (author)

  20. Actinide-only and full burn-up credit in criticality assessment of RBMK-1500 spent nuclear fuel storage cask using axial burn-up profile

    Energy Technology Data Exchange (ETDEWEB)

    Barkauskas, V., E-mail: vytenis.barkauskas@ftmc.lt; Plukiene, R., E-mail: rita.plukiene@ftmc.lt; Plukis, A., E-mail: arturas.plukis@ftmc.lt

    2016-10-15

    Highlights: • RBMK-1500 fuel burn-up impact on k{sub eff} in the SNF cask was calculated using SCALE 6.1. • Positive end effect was noticed at certain burn-up for the RBMK-1500 spent nuclear fuel. • The non-uniform uranium depletion is responsible for the end effect in RBMK-1500 SNF. • k{sub eff} in the SNF cask does not exceed a value of 0.95 which is set in the safety requirements. - Abstract: Safe long-term storage of spent nuclear fuel (SNF) is one of the main issues in the field of nuclear safety. Burn-up credit application in criticality analysis of SNF reduces conservatism of usually used fresh fuel assumption and implies a positive economic impact for the SNF storage. Criticality calculations of spent nuclear fuel in the CONSTOR® RBMK-1500/M2 cask were performed using pre-generated ORIGEN-ARP spent nuclear fuel composition libraries, and the results of the RBMK-1500 burn-up credit impact on the effective neutron multiplication factor (k{sub eff}) have been obtained and are presented in the paper. SCALE 6.1 code package with the STARBUCKS burn-up credit evaluation tool was used for modeling. Pre-generated ARP (Automatic Rapid Processing) crosssection libraries based on ENDF/B-VII cross section library were used for fast burn-up inventory modeling. Different conditions in the SNF cask were modeled: 2.0% and 2.8% initial enrichment fuel of various burn-up and water density inside cavities of the SNF cask. The fuel composition for the criticality analysis was chosen taking into account main actinides and most important fission products used in burn-up calculations. A significant positive end effect is noticed from 15 GWd/tU burn-up for 2.8% enrichment fuel and from 9 GWd/tU for 2.0% enrichment fuel applying the actinide-only approach. The obtained results may be applied in further evaluations of the RBMK type reactor SNF storage as well as help to optimize the SNF storage volume inside the CONSTOR® RBMK-1500/M2 cask without compromising criticality

  1. Development of Technical Basis for Burnup Credit Regulatory Guidance in the United States

    Energy Technology Data Exchange (ETDEWEB)

    Parks, Cecil V [ORNL; Wagner, John C [ORNL; Mueller, Don [ORNL; Gauld, Ian C [ORNL

    2011-01-01

    In the United States (U.S.) there has been and continues to be considerable interest in the increased use of burnup credit as part of the safety basis for SNF systems and this interest has motivated numerous technical studies related to the application of burnup credit for maintaining subcriticality. Responding to industry requests and needs, the U.S. Nuclear Regulatory Commission initiated a burnup credit research program, with support from the Oak Ridge National Laboratory, to develop regulatory guidance and the supporting technical basis for allowing and expanding the use of burnup credit in pressurized-water reactor SNF storage and transport applications. The objective of this paper is to summarize the work and significant accomplishments, with references to the technical reports and publications for complete details.

  2. Technical Development on Burn-up Credit for Spent LWR Fuel

    Energy Technology Data Exchange (ETDEWEB)

    Gauld, I.C.

    2001-12-26

    Technical development on burn-up credit for spent LWR fuels had been performed at JAERI since 1990 under the contract with Science and Technology Agency of Japan entitled ''Technical Development on Criticality Safety Management for Spent LWR Fuels.'' Main purposes of this work are to obtain the experimental data on criticality properties and isotopic compositions of spent LWR fuels and to verify burnup and criticality calculation codes. In this work three major experiments of exponential experiments for spent fuel assemblies to obtain criticality data, non-destructive gamma-ray measurement of spent fuel rods for evaluating axial burn-up profiles, and destructive analyses of spent fuel samples for determining precise burn-up and isotopic compositions were carried out. The measured data obtained were used for validating calculation codes as well as an examination of criticality safety analyses. Details of the work are described in this report.

  3. Topical Report on Actinide-Only Burnup Credit for PWR Spent Nuclear Fuel Packages. Revision 2

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    1998-09-01

    The objective of this topical report is to present to the NRC for review and acceptance a methodology for using burnup credit in the design of criticality control systems for PWR spent fuel transportation packages, while maintaining the criticality safety margins and related requirements of 10 CFR Part 71 and 72. The proposed methodology consists of five major steps as summarized below: (1) Validate a computer code system to calculate isotopic concentrations in SNF created during burnup in the reactor core and subsequent decay. (2) Validate a computer code system to predict the subcritical multiplication factor, keff, of a spent nuclear fuel package. (3) Establish bounding conditions for the isotopic concentration and criticality calculations. (4) Use the validated codes and bounding conditions to generate package loading criteria (burnup credit loading curves). and (5) Verify that SNF assemblies meet the package loading criteria and confirm proper fuel assembly selection prior to loading. (This step is required but the details are outside the scope of this topical report.) When reviewed and accepted by the NRC, this topical report will serve as a criterion document for criticality control analysts and will provide steps for the use of actinide-only burnup credit in the design of criticality control systems. The NRC-accepted burnup credit methodology will be used by commercial SNF storage and transportation package designers. Design-specific burnup credit criticality analyses will be defined, developed, and documented in the Safety Analysis Report (SAR) for each specific storage or transportation package that uses burnup credit. These SARs will then be submitted to the NRC for review and approval. This topical report is expected to be referenced in a number of storage and transportation cask applications to be submitted by commercial cask and canister designers to the NRC. Therefore, NRC acceptance of this topical report will result in increased efficiency of the

  4. A Criticality Evaluation of the GBC-32 Dry Storage Cask in PWR Burnup Credit

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Hyoungju; Park, Kwangheon; Hong, Ser Gi [Kyung Hee Univ., Yongin (Korea, Republic of)

    2015-05-15

    The current criticality safety evaluation assumes the only unirradiated fresh fuels with the maximum enrichment in a dry storage cask (DSC) for conservatism without consideration of the depletion of fissile nuclides and the generation of neutron-absorbing fission products. However, the large conservatism leads to the significant increase of the storage casks required. Thus, the application of burnup credit which takes credit for the reduction of reactivity resulted from fuel depletion can increase the capacity in storage casks. On the other hand, the burnup credit application introduces lots of complexity into a criticality safety analysis such as the accurate estimation of the isotopic inventories and the burnup of UNFs and the validation of the criticality calculation. The criticality evaluation with an effect of burnup credit was performed for the DSC of GBC-32 by using SCALE 6.1/STARBUCS. keff values were calculated as a function of burnup and cooling time for four initial enrichments of 2, 3, 4, and 5 wt. % 235U. The values were calculated for the burnup range of 0 to 60,000 MWD/MTU, in increments of 10,000 MWD/MTU, and for five cooling times of 0, 5, 10, 20, and 40 years.

  5. French investigations of high burnup effect on LOCA thermomechanical behavior: Part 1. Experimental programmes in support of LOCA design methodologies

    Energy Technology Data Exchange (ETDEWEB)

    Waeckel, N. [EDF/SEPTEN Villeurbanne (France); GrandJean, C. [IPSN, Cadarache (France); Cauvin, R.; Lebuffe, C. [EDF/SCMI, Chinon (France)

    1997-01-01

    Within the framework of Burn-Up extension request, EDF, FRAMATOME, CEA and IPSN have carried out experimental programmes in order to provide the design of fuel rods under LOCA conditions with relevant data. The design methods used in France for LOCA are based on standard Appendix K methodology updated to take into account some penalties related to the actual conditions of the Nuclear Power Plant. Best-Estimate assessments are used as well. Experimental programmes concern plastic deformation and burst behavior of advanced claddings (EDGAR) and thermal shock quenching behavior of highly irradiated claddings (TAGCIR). The former reveals the important role played by the {alpha}/{beta} transformation kinetics related to advanced alloys (Niobium alloys) and the latter the significative impact of hydrogen charged during in-reactor corrosion on oxidation kinetics and failure behavior in terms of cooling rates.

  6. High Burn-Up Spent Nuclear Fuel Vibration Integrity Study

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jy-An John [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Wang, Hong [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Jiang, Hao [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Bevard, Bruce Balkcom [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Howard, Rob L [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Scaglione, John M [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-01-01

    The Oak Ridge National Laboratory (ORNL) has developed the cyclic integrated reversible-bending fatigue tester (CIRFT) approach to successfully demonstrate the controllable fatigue fracture on high burnup (HBU) spent nuclear fuel (SNF) in a normal vibration mode. CIRFT enables examination of the underlying mechanisms of SNF system dynamic performance. Due to the inhomogeneous composite structure of the SNF system, the detailed mechanisms of the pellet-pellet and pellet-clad interactions and the stress concentration effects at the pellet-pellet interface cannot be readily obtained from a CIRFT system measurement. Therefore, finite element analyses (FEAs) are used to translate the global moment-curvature measurement into local stress-strain profiles for further investigation. The major findings of CIRFT on the HBU SNF are as follows: SNF system interface bonding plays an important role in SNF vibration performance. Fuel structure contributes to SNF system stiffness. There are significant variations in stress and curvature of SNF systems during vibration cycles resulting from segment pellets and clad interactions. SNF failure initiates at the pellet-pellet interface region and appears to be spontaneous.

  7. Tritium release from EXOTIC-7 orthosilicate pebbles. Effect of burnup and contact with beryllium during irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Scaffidi-Argentina, F.; Werle, H. [Forschungszentrum Karlsruhe GmbH Technik und Umwelt (Germany). Inst. fuer Neutronenphysik und Reaktortechnik

    1998-03-01

    EXOTIC-7 was the first in-pile test with {sup 6}Li-enriched (50%) lithium orthosilicate (Li{sub 4}SiO{sub 4}) pebbles and with DEMO representative Li-burnup. Post irradiation examinations of the Li{sub 4}SiO{sub 4} have been performed at the Forschungszentrum Karlsruhe (FZK), mainly to investigate the tritium release kinetics as well as the effect of Li-burnup and/or contact with beryllium during irradiation. The release rate of Li{sub 4}SiO{sub 4} from pure Li{sub 4}SiO{sub 4} bed of capsule 28.1-1 is characterized by a broad main peak at about 400degC and by a smaller peak at about 800degC, and that from the mixed beds of capsule 28.2 and 26.2-1 shows again these two peaks, but most of the tritium is now released from the 800degC peak. This shift of release from low to high temperature may be due to the higher Li-burnup and/or due to contact with Be during irradiation. Due to the very difficult interpretation of the in-situ tritium release data, residence times have been estimated on the basis of the out-of-pile tests. The residence time for Li{sub 4}SiO{sub 4} from caps. 28.1-1 irradiated at 10% Li-burnup agrees quite well with that of the same material irradiated at Li-burnup lower than 3% in the EXOTIC-6 experiment. In spite of the observed shift in the release peaks from low to high temperature, also the residence time for Li{sub 4}SiO{sub 4} from caps. 26.2-1 irradiated at 13% Li-burnup agrees quite well with the data from EXOTIC-6 experiment. On the other hand, the residence time for Li{sub 4}SiO{sub 4} from caps. 28.2 (Li-burnup 18%) is about a factor 1.7-3.8 higher than that for caps. 26.2-1. Based on these data on can conclude that up to 13% Li-burnup neither the contact with beryllium nor the Li-burnup have a detrimental effect on the tritium release of Li{sub 4}SiO{sub 4} pebbles, but at 18% Li-burnup the residence time is increased by about a factor three. (J.P.N.)

  8. Topical report on actinide-only burnup credit for PWR spent nuclear fuel packages. Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    1997-04-01

    A methodology for performing and applying nuclear criticality safety calculations, for PWR spent nuclear fuel (SNF) packages with actinide-only burnup credit, is described. The changes in the U-234, U-235, U-236, U-238, Pu-238, Pu-239, Pu-240, Pu-241, Pu-242, and Am-241 concentration with burnup are used in burnup credit criticality analyses. No credit for fission product neutron absorbers is taken. The methodology consists of five major steps. (1) Validate a computer code system to calculate isotopic concentrations of SNF created during burnup in the reactor core and subsequent decay. A set of chemical assay benchmarks is presented for this purpose as well as a method for assessing the calculational bias and uncertainty, and conservative correction factors for each isotope. (2) Validate a computer code system to predict the subcritical multiplication factor, k{sub eff}, of a spent nuclear fuel package. Fifty-seven UO{sub 2}, UO{sub 2}/Gd{sub 2}O{sub 3}, and UO{sub 2}/PuO{sub 2} critical experiments have been selected to cover anticipated conditions of SNF. The method uses an upper safety limit on k{sub eff} (which can be a function of the trending parameters) such that the biased k{sub eff}, when increased for the uncertainty is less than 0.95. (3) Establish bounding conditions for the isotopic concentration and criticality calculations. Three bounding axial profiles have been established to assure the ''end effect'' is accounted for conservatively. (4) Use the validated codes and bounding conditions to generate package loading criteria (burnup credit loading curves). Burnup credit loading curves show the minimum burnup required for a given initial enrichment. The utility burnup record is compared to this requirement after the utility accounts for the uncertainty in its record. Separate curves may be generated for each assembly design, various minimum cooling times and burnable absorber histories. (5) Verify that SNF assemblies meet the package

  9. Summary of high burnup fuel issues and NRC`s plan of action

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, R.O.

    1997-01-01

    For the past two years the Office of Nuclear Regulatory Research has concentrated mostly on the so-called reactivity-initiated accidents -- the RIAs -- in this session of the Water Reactor Safety Information Meeting, but this year there is a more varied agenda. RIAs are, of course, not the only events of interest for reactor safety that are affected by extended burnup operation. Their has now been enough time to consider a range of technical issues that arise at high burnup, and a list of such issues being addressed in their research program is given here. (1) High burnup capability of the steady-state code (FRAPCON) used for licensing audit calculations. (2) General capability (including high burnup) of the transient code (FRAPTRAN) used for special studies. (3) Adequacy at high burnup of fuel damage criteria used in regulation for reactivity accidents. (4) Adequacy at high burnup of models and fuel related criteria used in regulation for loss-of-coolant accidents (LOCAs). (5) Effect of high burnup on fuel system damage during normal operation, including control rod insertion problems. A distinction is made between technical issues, which may or may not have direct licensing impacts, and licensing issues. The RIAs became a licensing issue when the French test in CABRI showed that cladding failures could occur at fuel enthalpies much lower than a value currently used in licensing. Fuel assembly distortion became a licensing issue when control rod insertion was affected in some operating plants. In this presentation, these technical issues will be described and the NRC`s plan of action to address them will be discussed.

  10. A simple gamma spectrometry method for evaluating the burnup of MTR-type HEU fuel elements

    Energy Technology Data Exchange (ETDEWEB)

    Makmal, T. [The Unit of Nuclear Engineering, Ben-Gurion University of The Negev, Beer-Sheva 84105 (Israel); Nuclear Physics and Engineering Division, Soreq Nuclear Research Center, Yavne 81800 (Israel); Aviv, O. [Radiation Safety Division, Soreq Nuclear Research Center, Yavne 81800 (Israel); Gilad, E., E-mail: gilade@bgu.ac.il [The Unit of Nuclear Engineering, Ben-Gurion University of The Negev, Beer-Sheva 84105 (Israel)

    2016-10-21

    A simple method for the evaluation of the burnup of a materials testing reactor (MTR) fuel element by gamma spectrometry is presented. The method was applied to a highly enriched uranium MTR nuclear fuel element that was irradiated in a 5 MW pool-type research reactor for a total period of 34 years. The experimental approach is based on in-situ measurements of the MTR fuel element in the reactor pool by a portable high-purity germanium detector located in a gamma cell. To corroborate the method, analytical calculations (based on the irradiation history of the fuel element) and computer simulations using a dedicated fuel cycle burnup code ORIGEN2 were performed. The burnup of the MTR fuel element was found to be 52.4±8.8%, which is in good agreement with the analytical calculations and the computer simulations. The method presented here is suitable for research reactors with either a regular or an irregular irradiation regime and for reactors with limited infrastructure and/or resources. In addition, its simplicity and the enhanced safety it confers may render this method suitable for IAEA inspectors in fuel element burnup assessments during on-site inspections. - Highlights: • Simple, inexpensive, safe and flexible experimental setup that can be quickly deployed. • Experimental results are thoroughly corroborated against ORIGEN2 burnup code. • Experimental uncertainty of 9% and 5% deviation between measurements and simulations. • Very high burnup MTR fuel element is examined, with 60% depletion of {sup 235}U. • Impact of highly irregular irradiation regime on burnup evaluation is studied.

  11. A Simple Formula for Local Burnup and Isotope Distributions Based on Approximately Constant Relative Reaction Rate

    Directory of Open Access Journals (Sweden)

    Cenxi Yuan

    2016-01-01

    Full Text Available A simple and analytical formula is suggested to solve the problems of the local burnup and the isotope distributions. The present method considers two extreme conditions of neutrons penetrating the fuel rod. Based on these considerations, the formula is obtained to calculate the reaction rates of 235U, 238U, and 239Pu and straightforward the local burnup and the isotope distributions. Starting from an initial burnup level, the parameters of the formula are fitted to the reaction rates given by a Monte Carlo (MC calculation. Then the present formula independently gives very similar results to the MC calculation from the starting to high burnup level but takes just a few minutes. The relative reaction rates are found to be almost independent of the radius (except (n,γ of  238U and the burnup, providing a solid background for the present formula. A more realistic examination is also performed when the fuel rods locate in an assembly. A combination of the present formula and the MC calculation is expected to have a nice balance between the numerical accuracy and time consumption.

  12. Spent fuel pool storage calculations using the ISOCRIT burnup credit tool

    Energy Technology Data Exchange (ETDEWEB)

    Kucukboyaci, Vefa [Westinghouse Electric Company, Cranberry Township, PA; Marshall, William BJ J [ORNL

    2012-01-01

    In order to conservatively apply burnup credit in spent fuel pool criticality safety analyses, Westinghouse has developed a software tool, ISOCRIT, for generating depletion isotopics. This tool is used to create isotopics data based on specific reactor input parameters, such as design basis assembly type; bounding power/burnup profiles; reactor specific moderator temperature profiles; pellet percent theoretical density; burnable absorbers, axial blanket regions, and bounding ppm boron concentration. ISOCRIT generates burnup dependent isotopics using PARAGON; Westinghouse's state-of-the-art and licensed lattice physics code. Generation of isotopics and passing the data to the subsequent 3D KENO calculations are performed in an automated fashion, thus reducing the chance for human error. Furthermore, ISOCRIT provides the means for responding to any customer request regarding re-analysis due to changed parameters (e.g., power uprate, exit temperature changes, etc.) with a quick turnaround.

  13. Burn-up dependent steady-state thermal hydraulic analysis of Pakistan research reactor-1

    Directory of Open Access Journals (Sweden)

    Muhammad Atta

    2011-01-01

    Full Text Available The burn-up dependent steady-state thermal hydraulic analysis of Pakistan research reactor-1, reference operating core, has been carried out utilizing standard computer codes WIMS/D4, CITATION, and RELAP5/MOD3.4. Reactor codes WIMS/D4 and CITATION have been used for the calculations of neutronic parameters including peaking factors and power profiles at different burn-up considering a xenon free core and also the equilibrium xenon values. RELAP5/MOD3.4 code was utilized for the determination of peak fuel centerline, clad and coolant temperatures to ensure the safety of the reactor throughout the cycle. The calculations reveal that the reactor is safe and no nucleate boiling will commence at any part of the core throughout the cycle and that the safety margin increases with burnup as peaking factors decrease.

  14. EPRI/DOE High-Burnup Fuel Sister Rod Test Plan Simplification and Visualization

    Energy Technology Data Exchange (ETDEWEB)

    Saltzstein, Sylvia J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Sorenson, Ken B. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hanson, B. D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Shimskey, R. W. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Klymyshyn, N. A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Webster, R. A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Jensen, P. J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); MacFarlan, P. J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Billone, Mike [Argonne National Lab. (ANL), Argonne, IL (United States); Scaglione, John [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Montgomery, Rose [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Bevard, Bruce [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-09-15

    The EPRI/DOE High-Burnup Confirmatory Data Project (herein called the “Demo”) is a multi-year, multi-entity test with the purpose of providing quantitative and qualitative data to show if high-burnup fuel mechanical properties change in dry storage over a ten-year period. The Demo involves obtaining 32 assemblies of high-burnup PWR fuel of common cladding alloys from the North Anna Nuclear Power Plant, loading them in an NRC-licensed TN-32B cask, drying them according to standard plant procedures, and then storing them on the North Anna dry storage pad for ten years. After the ten-year storage time, the cask will be opened and the mechanical properties of the rods will be tested and analyzed.

  15. An iterative approach for TRIGA fuel burn-up determination using nondestructive gamma-ray spectrometry.

    Science.gov (United States)

    Wang, T K; Peir, J J

    2000-01-01

    The purpose of this work is to establish a method for evaluating the burn-up values of the rod-type TRIGA spent fuel by using gamma-ray spectrometry of the short-lived fission products 97Zr/97Nb, 132I, and 140La. Fuel irradiation history is not needed in this method. Short-lived fission-product activities were established by reirradiating the spent fuels in a nuclear reactor. Based on the measured activities, 235U burn-up values can be deduced by iterative calculations. The complication caused by 239Pu production and fission is also discussed in detail. The burn-up values obtained by this method are in good agreement with those deduced from the conventional method based on long-lived fission products 137Cs, 134Cs/137Cs ratio and 106Ru/137Cs ratio.

  16. Addressing Fission Product Validation in MCNP Burnup Credit Criticality Calculations

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, Don [ORNL; Bowen, Douglas G [ORNL; Marshall, William BJ J [ORNL

    2015-01-01

    The US Nuclear Regulatory Commission (NRC) Division of Spent Fuel Storage and Transportation issued Interim Staff Guidance (ISG) 8, Revision 3 in September 2012. This ISG provides guidance for NRC staff members’ review of burnup credit (BUC) analyses supporting transport and dry storage of pressurized water reactor spent nuclear fuel (SNF) in casks. The ISG includes guidance for addressing validation of criticality (keff) calculations crediting the presence of a limited set of fission products and minor actinides (FP&MAs). Based on previous work documented in NRC Regulatory Guide (NUREG) Contractor Report (CR)-7109, the ISG recommends that NRC staff members accept the use of either 1.5 or 3% of the FP&MA worth—in addition to bias and bias uncertainty resulting from validation of keff calculations for the major actinides in SNF—to conservatively account for the bias and bias uncertainty associated with the specified unvalidated FP&MAs. The ISG recommends (1) use of 1.5% of the FP&MA worth if a modern version of SCALE and its nuclear data are used and (2) 3% of the FP&MA worth for well qualified, industry standard code systems other than SCALE with the Evaluated Nuclear Data Files, Part B (ENDF/B),-V, ENDF/B-VI, or ENDF/B-VII cross sections libraries. The work presented in this paper provides a basis for extending the use of the 1.5% of the FP&MA worth bias to BUC criticality calculations performed using the Monte Carlo N-Particle (MCNP) code. The extended use of the 1.5% FP&MA worth bias is shown to be acceptable by comparison of FP&MA worths calculated using SCALE and MCNP with ENDF/B-V, -VI, and -VII–based nuclear data. The comparison supports use of the 1.5% FP&MA worth bias when the MCNP code is used for criticality calculations, provided that the cask design is similar to the hypothetical generic BUC-32 cask model and that the credited FP&MA worth is no more than 0.1 Δkeff (ISG-8, Rev. 3, Recommendation 4).

  17. Impact investigation of reactor fuel operating parameters on reactivity for use in burnup credit applications

    Science.gov (United States)

    Sloma, Tanya Noel

    When representing the behavior of commercial spent nuclear fuel (SNF), credit is sought for the reduced reactivity associated with the net depletion of fissile isotopes and the creation of neutron-absorbing isotopes, a process that begins when a commercial nuclear reactor is first operated at power. Burnup credit accounts for the reduced reactivity potential of a fuel assembly and varies with the fuel burnup, cooling time, and the initial enrichment of fissile material in the fuel. With regard to long-term SNF disposal and transportation, tremendous benefits, such as increased capacity, flexibility of design and system operations, and reduced overall costs, provide an incentive to seek burnup credit for criticality safety evaluations. The Nuclear Regulatory Commission issued Interim Staff Guidance 8, Revision 2 in 2002, endorsing burnup credit of actinide composition changes only; credit due to actinides encompasses approximately 30% of exiting pressurized water reactor SNF inventory and could potentially be increased to 90% if fission product credit were accepted. However, one significant issue for utilizing full burnup credit, compensating for actinide and fission product composition changes, is establishing a set of depletion parameters that produce an adequately conservative representation of the fuel's isotopic inventory. Depletion parameters can have a significant effect on the isotopic inventory of the fuel, and thus the residual reactivity. This research seeks to quantify the reactivity impact on a system from dominant depletion parameters (i.e., fuel temperature, moderator density, burnable poison rod, burnable poison rod history, and soluble boron concentration). Bounding depletion parameters were developed by statistical evaluation of a database containing reactor operating histories. The database was generated from summary reports of commercial reactor criticality data. Through depletion calculations, utilizing the SCALE 6 code package, several light

  18. Fission Product Inventory and Burnup Evaluation of the AGR-2 Irradiation by Gamma Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Harp, Jason Michael [Idaho National Lab. (INL), Idaho Falls, ID (United States); Stempien, John Dennis [Idaho National Lab. (INL), Idaho Falls, ID (United States); Demkowicz, Paul Andrew [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-09-01

    Gamma spectrometry has been used to evaluate the burnup and fission product inventory of different components from the US Advanced Gas Reactor Fuel Development and Qualification Program's second TRISO-coated particle fuel irradiation test (AGR-2). TRISO fuel in this irradiation included both uranium carbide / uranium oxide (UCO) kernels and uranium oxide (UO2) kernels. Four of the 6 capsules contained fuel from the US Advanced Gas Reactor program, and only those capsules will be discussed in this work. The inventories of gamma-emitting fission products from the fuel compacts, graphite compact holders, graphite spacers and test capsule shell were evaluated. These data were used to measure the fractional release of fission products such as Cs-137, Cs-134, Eu-154, Ce-144, and Ag-110m from the compacts. The fraction of Ag-110m retained in the compacts ranged from 1.8% to full retention. Additionally, the activities of the radioactive cesium isotopes (Cs-134 and Cs-137) have been used to evaluate the burnup of all US TRISO fuel compacts in the irradiation. The experimental burnup evaluations compare favorably with burnups predicted from physics simulations. Predicted burnups for UCO compacts range from 7.26 to 13.15 % fission per initial metal atom (FIMA) and 9.01 to 10.69 % FIMA for UO2 compacts. Measured burnup ranged from 7.3 to 13.1 % FIMA for UCO compacts and 8.5 to 10.6 % FIMA for UO2 compacts. Results from gamma emission computed tomography performed on compacts and graphite holders that reveal the distribution of different fission products in a component will also be discussed. Gamma tomography of graphite holders was also used to locate the position of TRISO fuel particles suspected of having silicon carbide layer failures that lead to in-pile cesium release.

  19. Study on core physics characteristics of high burn-up full MOX PWR core. 2

    Energy Technology Data Exchange (ETDEWEB)

    Kugo, Teruhiko; Okubo, Tsutomu; Shimada, Syoichiro [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1999-09-01

    As one of options for future light water reactors, we have been studying a new concept of a high burn-up full MOX PWR core with a discharge burn-up of 100 GWd/t and a 3-year operation cycle being based on the existing light water reactor technology. We have already confirmed the feasibility of the core, in which a moderator to fuel volume ratio(Vm/Vf) is increased to 2.6 with the same fuel pin diameter of 9.5 mm as in the current PWR but with the enlarged fuel pin pitch of 13.8 mm. In this report, to improve the neutronics and thermal hydraulic performance of the high burn-up core, we subsequently propose a 600 MWe core ensuring discharge burn-up of 100 GWd/t by increasing Vm/Vf to 3.0 with the same fuel pin pitch of 12.6 mm as in the current PWR and the smaller fuel rod diameter of 8.3 mm instead of 9.5 mm. We have investigated its core characteristics in neutronics and confirmed its feasibility. The core neutronics performance is compared between Vm/Vf = 2.6 and 3.0. From the comparison, it is found that the proposed core with Vm/Vf 3.0 has more promising characteristics than with Vm/Vf = 2.6 such as saving of a fissile plutonium content of 0.3wt%, improvement in a departure from nucleate boiling ratio (DNBR) and so on, except for a shortened cycle length by 9%. In addition, we have investigated a low-leakage refueling scheme for both types of high burn-up cores. Without modification to fuel material such as addition of burnable poison and/or transuranium isotopes, it can not be expected to improve the burn-up efficiency by the low-leakage refueling scheme. (author)

  20. Fission Product Inventory and Burnup Evaluation of the AGR-2 Irradiation by Gamma Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Harp, Jason M.; Demkowicz, Paul A.; Stempien, John D.

    2016-11-01

    Gamma spectrometry has been used to evaluate the burnup and fission product inventory of different components from the US Advanced Gas Reactor Fuel Development and Qualification Program's second TRISO-coated particle fuel irradiation test (AGR-2). TRISO fuel in this irradiation included both uranium carbide / uranium oxide (UCO) kernels and uranium oxide (UO2) kernels. Four of the 6 capsules contained fuel from the US Advanced Gas Reactor program, and only those capsules will be discussed in this work. The inventories of gamma-emitting fission products from the fuel compacts, graphite compact holders, graphite spacers and test capsule shell were evaluated. These data were used to measure the fractional release of fission products such as Cs-137, Cs-134, Eu-154, Ce-144, and Ag-110m from the compacts. The fraction of Ag-110m retained in the compacts ranged from 1.8% to full retention. Additionally, the activities of the radioactive cesium isotopes (Cs-134 and Cs-137) have been used to evaluate the burnup of all US TRISO fuel compacts in the irradiation. The experimental burnup evaluations compare favorably with burnups predicted from physics simulations. Predicted burnups for UCO compacts range from 7.26 to 13.15 % fission per initial metal atom (FIMA) and 9.01 to 10.69 % FIMA for UO2 compacts. Measured burnup ranged from 7.3 to 13.1 % FIMA for UCO compacts and 8.5 to 10.6 % FIMA for UO2 compacts. Results from gamma emission computed tomography performed on compacts and graphite holders that reveal the distribution of different fission products in a component will also be discussed. Gamma tomography of graphite holders was also used to locate the position of TRISO fuel particles suspected of having silicon carbide layer failures that lead to in-pile cesium release.

  1. NUCLEAR DATA UNCERTAINTY PROPAGATION FOR A TYPICAL PWR FUEL ASSEMBLY WITH BURNUP

    Directory of Open Access Journals (Sweden)

    D. ROCHMAN

    2014-06-01

    Full Text Available The effects of nuclear data uncertainties are studied on a typical PWR fuel assembly model in the framework of the OECD Nuclear Energy Agency UAM (Uncertainty Analysis in Modeling expert working group. The “Fast Total Monte Carlo” method is applied on a model for the Monte Carlo transport and burnup code SERPENT. Uncertainties on k∞, reaction rates, two-group cross sections, inventory and local pin power density during burnup are obtained, due to transport cross sections for the actinides and fission products, fission yields and thermal scattering data.

  2. Fuel burnup calculation of Ghana MNSR using ORIGEN2 and REBUS3 codes.

    Science.gov (United States)

    Abrefah, R G; Nyarko, B J B; Fletcher, J J; Akaho, E H K

    2013-10-01

    Ghana Research Reactor-1 core is to be converted from HEU fuel to LEU fuel in the near future and managing the spent nuclear fuel is very important. A fuel depletion analysis of the GHARR-1 core was performed using ORIGEN2 and REBUS3 codes to estimate the isotopic inventory at end-of-cycle in order to help in the design of an appropriate spent fuel cask. The results obtained for both codes were consistent for U-235 burnup weight percent and Pu-239 build up as a result of burnup. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. Nuclear Energy Research Initiative. Development of a Stabilized Light Water Reactor Fuel Matrix for Extended Burnup

    Energy Technology Data Exchange (ETDEWEB)

    BD Hanson; J Abrefah; SC Marschman; SG Prussin

    2000-09-08

    The main objective of this project is to develop an advanced fuel matrix capable of achieving extended burnup while improving safety margins and reliability for present operations. In the course of this project, the authors improve understanding of the mechanism for high burnup structure (HBS) formation and attempt to design a fuel to minimize its formation. The use of soluble dopants in the UO{sub 2} matrix to stabilize the matrix and minimize fuel-side corrosion of the cladding is the main focus.

  4. Progress of the RIA experiments with high burnup fuels and their evaluation in JAERI

    Energy Technology Data Exchange (ETDEWEB)

    Ishijima, Kiyomi; Fuketa, Toyoshi [Japan Atomic Energy Research Institute, Ibaraki-ken (Japan)

    1997-01-01

    Recent results obtained in the NSRR power burst experiments with high burnup PWR fuel rods are described and discussed in this paper. Data concerning test condition, transient records during pulse irradiation and post irradiation examination are described. Another high burnup PWR fuel rod failed in the test HBO-5 at the slightly higher energy deposition than that in the test HBO-1. The failure mechanism of the test HBO-5 is the same as that of the test HBO-1, that is, hydride-assisted PCMI. Some influence of the thermocouples welding on the failure behavior of the HBO-5 rod was observed.

  5. Post Irradiation Examination Plan for High-Burnup Demonstration Project Sister Rods

    Energy Technology Data Exchange (ETDEWEB)

    Scaglione, John M [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Montgomery, Rose [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Bevard, Bruce Balkcom [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-04-01

    This test plan describes the experimental work to be implemented by the U.S. Department of Energy (DOE) Office of Nuclear Energy (NE) to characterize high burnup (HBU) spent nuclear fuel (SNF) in conjunction with the High Burnup Dry Storage Cask Research and Development Project and serves to coordinate and integrate the multi-year experimental program to collect and develop data regarding the continued storage and eventual transport of HBU (i.e., >45 GWd/MTU) SNF. The work scope involves the development, performance, technical integration, and oversight of measurements and collection of relevant data, guided by analyses and demonstration of need.

  6. Temperature and Burnup Correlated FCCI in U-10Zr Metallic Fuel

    Energy Technology Data Exchange (ETDEWEB)

    William J. Carmack

    2012-05-01

    Metallic fuels are proposed for use in advanced sodium cooled fast reactors. The experience basis for metallic fuels is extensive and includes development and qualification of fuels for the Experimental Breeder Reactor I, the Experimental Breeder Reactor II, FERMI-I, and the Fast Flux Test Facility (FFTF) reactors. Metallic fuels provide a number of advantages over other fuel types in terms of fabricability, performance, recyclability, and safety. Key to the performance of all nuclear fuel systems is the resistance to “breach” and subsequent release of fission products and fuel constituents to the primary coolant system of the nuclear power plant. In metallic fuel, the experience is that significant fuel-cladding chemical (FCCI) interaction occurs and becomes prevalent at high power-high temperature operation and ultimately leads to fuel pin breach and failure. Empirical relationships for metallic fuel pin failure have been developed from a large body of in-pile and out of pile research, development, and experimentation. It has been found that significant in-pile acceleration of the FCCI rate is experienced over similar condition out-of-pile experiments. The study of FCCI in metallic fuels has led to the quantification of in-pile failure rates to establish an empirical time and temperature dependent failure limit for fuel elements. Up until now the understanding of FCCI layer formation has been limited to data generated in EBR-II experiments. This dissertation provides new FCCI data extracted from the MFF-series of metallic fuel irradiations performed in the FFTF. These fuel assemblies contain valuable information on the formation of FCCI in metallic fuels at a variety of temperature and burnup conditions and in fuel with axial fuel height three times longer than EBR-II experiments. The longer fuel column in the FFTF and the fuel pins examined have significantly different flux, power, temperature, and FCCI profiles than that found in similar tests conducted in

  7. The Gd-isotopic fuel for high burnup in PWR's

    Energy Technology Data Exchange (ETDEWEB)

    Dias, Marcio Soares; Mattos, João Roberto L. de; Andrade, Edison Pereira de, E-mail: marciod@cdtn.br, E-mail: jrmattos@cdtn.br, E-mail: epa@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2017-07-01

    Today, the discussion about the high burnup fuel is beyond the current fuel enrichment licensing and burnup limits. Licensing issues and material/design developments are again key features in further development of the LWR fuel design. Nevertheless, technological and economical solutions are already available or will be available in a short time. In order to prevent the growth of the technological gap, Brazil's nuclear sector needs to invest in the training of new human resources, in the access to international databases, and in the upgrading existing infrastructure. Experimental database and R&D infrastructure are essential components to support the autonomous development of Brazilian Nuclear Reactors, promoting the development of national technologies. The (U,Gd)O{sub 2} isotopic fuel proposed by the CDTN's staff solve two main issues in the high burnup fuel, which are (1) the peak of reactivity resulting from the Gd-157 fast burnup, and (2) the peak of temperature in the (U,Gd)O{sub 2} nuclear fuel resulting from detrimental effects in the thermal properties for gadolinia additions higher than 2%. A sustainable future can be envisaged for the nuclear energy. (author)

  8. About a fuel for burnup reactor of periodical pulsed nuclear pumped laser

    Energy Technology Data Exchange (ETDEWEB)

    Volkov, A.I.; Lukin, A.V.; Magda, L.E.; Magda, E.P.; Pogrebov, I.S.; Putnikov, I.S.; Khmelnitsky, D.V.; Scherbakov, A.P. [Russian Federal Nuclear Center, Snezhinsk (Russian Federation)

    1998-07-01

    A physical scheme of burnup reactor for a Periodic Pulsed Nuclear Pumped Laser was supposed. Calculations of its neutron physical parameters were made. The general layout and construction of basic elements of the reactor are discussed. The requirements for the fuel and fuel elements are established. (author)

  9. Modeling of Pore Coarsening in the Rim Region of High Burn-up UO2 Fuel

    Directory of Open Access Journals (Sweden)

    Hongxing Xiao

    2016-08-01

    Full Text Available An understanding of the coarsening process of the large fission gas pores in the high burn-up structure (HBS of irradiated UO2 fuel is very necessary for analyzing the safety and reliability of fuel rods in a reactor. A numerical model for the description of pore coarsening in the HBS based on the Ostwald ripening mechanism, which has successfully explained the coarsening process of precipitates in solids is developed. In this model, the fission gas atoms are treated as the special precipitates in the irradiated UO2 fuel matrix. The calculated results indicate that the significant pore coarsening and mean pore density decrease in the HBS occur upon surpassing a local burn-up of 100 GWd/tM. The capability of this model is successfully validated against irradiation experiments of UO2 fuel, in which the average pore radius, pore density, and porosity are directly measured as functions of local burn-up. Comparisons with experimental data show that, when the local burn-up exceeds 100 GWd/tM, the calculated results agree well with the measured data.

  10. Dependence of heavy metal burnup on nuclear data libraries for fast reactors

    CERN Document Server

    Ohki, S

    2003-01-01

    Japan Nuclear Cycle Development Institute (JNC) is considering the highly burnt fuel as well as the recycling of minor actinide (MA) in the development of commercialized fast reactor cycle systems. Higher accuracy in burnup calculation is going to be required for higher mass plutonium isotopes ( sup 2 sup 4 sup 0 Pu, etc.) and MA nuclides. In the framework of research and development aiming at the validation and necessary improvements of fast reactor burnup calculation, we investigated the differences among the burnup calculation results with the major nuclear data libraries: JEF-2.2, ENDF/B-VI Release 5, JENDL-3.2, and JENDL-3.3. We focused on the heavy metal nuclides such as plutonium and MA in the central core region of a conventional sodium-cooled fast reactor. For main heavy metal nuclides ( sup 2 sup 3 sup 5 U, sup 2 sup 3 sup 8 U, sup 2 sup 3 sup 9 Pu, sup 2 sup 4 sup 0 Pu, and sup 2 sup 4 sup 1 Pu), number densities after 1-cycle burnup did not change over one or two percent. Library dependence was re...

  11. Depletion of gadolinium burnable poison in a PWR assembly with high burnup fuel

    Energy Technology Data Exchange (ETDEWEB)

    Refeat, Riham Mahmoud [Nuclear and Radiological Regulatory Authority (NRRA), Cairo (Egypt). Safety Engineering Dept.

    2015-12-15

    A tendency to increase the discharge burnup of nuclear fuel for Advanced Pressurized Water Reactors (PWR) has been a characteristic of its operation for many years. It will be able to burn at very high burnup of about 70 GWd/t with UO{sub 2} fuels. The U-235 enrichment must be higher than 5 %, which leads to the necessity of using an extremely efficient burnable poison like Gadolinium oxide. Using gadolinium isotope is significant due to its particular depletion behavior (''Onion-Skin'' effect). In this paper, the MCNPX2.7 code is used to calculate the important neutronic parameters of the next generation fuels of PWR. K-infinity, local peaking factor and fission rate distributions are calculated for a PWR assembly which burn at very high burnup reaching 70 GWd/t. The calculations are performed using the recently released evaluated Gadolinium cross section data. The results obtained are close to those of a LWR next generation fuel benchmark problem. This demonstrates that the calculation scheme used is able to accurately model a PWR assembly that operates at high burnup values.

  12. A complete NUHOMS {sup registered} solution for storage and transport of high burnup spent fuel

    Energy Technology Data Exchange (ETDEWEB)

    Bondre, J. [Transnuclear, Inc. (AREVA Group), Fremont, CA (United States)

    2004-07-01

    The discharge burnups of spent fuel from nuclear power plants keep increasing with plants discharging or planning to discharge fuel with burnups in excess of 60,000 MWD/MTU. Due to limited capacity of spent fuel pools, transfer of older cooler spent fuel from fuel pool to dry storage, and very limited options for transport of spent fuel, there is a critical need for dry storage of high burnup, higher heat load spent fuel so that plants could maintain their full core offload reserve capability. A typical NUHOMS {sup registered} solution for dry spent fuel storage is shown in the Figure 1. Transnuclear, Inc. offers two advanced NUHOMS {sup registered} solutions for the storage and transportation of high burnup fuel. One includes the NUHOMS {sup registered} 24PTH system for plants with 90.7 Metric Ton (MT) crane capacity; the other offers the higher capacity NUHOMS {sup registered} 32PTH system for higher crane capacity. These systems include NUHOMS {sup registered} - 24PTH and -32PTH Transportable Canisters stored in a concrete storage overpack (HSM-H). These canisters are designed to meet all the requirements of both storage and transport regulations. They are designed to be transported off-site either directly from the spent fuel pool or from the storage overpack in a suitable transport cask.

  13. Radiochemical Assays of Irradiated VVER-440 Fuel for Use in Spent Fuel Burnup Credit Activities

    Energy Technology Data Exchange (ETDEWEB)

    Jardine, L J

    2005-04-25

    The objective of this spent fuel burnup credit work was to study and describe a VVER-440 reactor spent fuel assembly (FA) initial state before irradiation, its operational irradiation history and the resulting radionuclide distribution in the fuel assembly after irradiation. This work includes the following stages: (1) to pick out and select a specific spent (irradiated) FA for examination; (2) to describe the FA initial state before irradiation; (3) to describe the irradiation history, including thermal calculations; (4) to examine the burnup distribution of select radionuclides along the FA height and cross-section; (5) to examine the radionuclide distributions; (6) to determine the Kr-85 release into the plenum; (7) to select and prepare FA rod specimens for destructive examinations; (8) to determine the radionuclide compositions, isotope masses and burnup in the rod specimens; and (9) to analyze, document and process the results. The specific workscope included the destructive assay (DA) of spent fuel assembly rod segments with an {approx}38.5 MWd/KgU burnup from a single VVER-440 fuel assembly from the Novovorenezh reactor in Russia. Based on irradiation history criteria, four rods from the fuel assembly were selected and removed from the assembly for examination. Next, 8 sections were cut from the four rods and sent for destructive analysis of radionuclides by radiochemical analyses. The results were documented in a series of seven reports over a period of {approx}1 1/2 years.

  14. Benefits of the delta K of depletion benchmarks for burnup credit validation

    Energy Technology Data Exchange (ETDEWEB)

    Lancaster, D. [NuclearConsultants.com, 187 Faith Circle, Boalsburg, PA 16827 (United States); Machiels, A. [Electric Power Research Inst., Inc., 3420 Hillview Avenue, Palo Alto, CA 94304 (United States)

    2012-07-01

    Pressurized Water Reactor (PWR) burnup credit validation is demonstrated using the benchmarks for quantifying fuel reactivity decrements, published as 'Benchmarks for Quantifying Fuel Reactivity Depletion Uncertainty,' EPRI Report 1022909 (August 2011). This demonstration uses the depletion module TRITON available in the SCALE 6.1 code system followed by criticality calculations using KENO-Va. The difference between the predicted depletion reactivity and the benchmark's depletion reactivity is a bias for the criticality calculations. The uncertainty in the benchmarks is the depletion reactivity uncertainty. This depletion bias and uncertainty is used with the bias and uncertainty from fresh UO{sub 2} critical experiments to determine the criticality safety limits on the neutron multiplication factor, k{sub eff}. The analysis shows that SCALE 6.1 with the ENDF/B-VII 238-group cross section library supports the use of a depletion bias of only 0.0015 in delta k if cooling is ignored and 0.0025 if cooling is credited. The uncertainty in the depletion bias is 0.0064. Reliance on the ENDF/B V cross section library produces much larger disagreement with the benchmarks. The analysis covers numerous combinations of depletion and criticality options. In all cases, the historical uncertainty of 5% of the delta k of depletion ('Kopp memo') was shown to be conservative for fuel with more than 30 GWD/MTU burnup. Since this historically assumed burnup uncertainty is not a function of burnup, the Kopp memo's recommended bias and uncertainty may be exceeded at low burnups, but its absolute magnitude is small. (authors)

  15. Propagation of statistical and nuclear data uncertainties in Monte Carlo burn-up calculations

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Herranz, Nuria [Departamento de Ingenieria Nuclear, Universidad Politecnica de Madrid, UPM (Spain)], E-mail: nuria@din.upm.es; Cabellos, Oscar [Departamento de Ingenieria Nuclear, Universidad Politecnica de Madrid, UPM (Spain); Sanz, Javier [Departamento de Ingenieria Energetica, Universidad Nacional de Educacion a Distancia, UNED (Spain); Juan, Jesus [Laboratorio de Estadistica, Universidad Politecnica de Madrid, UPM (Spain); Kuijper, Jim C. [NRG - Fuels, Actinides and Isotopes Group, Petten (Netherlands)

    2008-04-15

    Two methodologies to propagate the uncertainties on the nuclide inventory in combined Monte Carlo-spectrum and burn-up calculations are presented, based on sensitivity/uncertainty and random sampling techniques (uncertainty Monte Carlo method). Both enable the assessment of the impact of uncertainties in the nuclear data as well as uncertainties due to the statistical nature of the Monte Carlo neutron transport calculation. The methodologies are implemented in our MCNP-ACAB system, which combines the neutron transport code MCNP-4C and the inventory code ACAB. A high burn-up benchmark problem is used to test the MCNP-ACAB performance in inventory predictions, with no uncertainties. A good agreement is found with the results of other participants. This benchmark problem is also used to assess the impact of nuclear data uncertainties and statistical flux errors in high burn-up applications. A detailed calculation is performed to evaluate the effect of cross-section uncertainties in the inventory prediction, taking into account the temporal evolution of the neutron flux level and spectrum. Very large uncertainties are found at the unusually high burn-up of this exercise (800 MWd/kgHM). To compare the impact of the statistical errors in the calculated flux with respect to the cross uncertainties, a simplified problem is considered, taking a constant neutron flux level and spectrum. It is shown that, provided that the flux statistical deviations in the Monte Carlo transport calculation do not exceed a given value, the effect of the flux errors in the calculated isotopic inventory are negligible (even at very high burn-up) compared to the effect of the large cross-section uncertainties available at present in the data files.

  16. Application of Genetic Algorithm methodologies in fuel bundle burnup optimization of Pressurized Heavy Water Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Jayalal, M.L., E-mail: jayalal@igcar.gov.in [Electronics, Instrumentation and Radiological Safety Group (EIRSG), Indira Gandhi Centre for Atomic Research (IGCAR), Kalpakkam, Tamil Nadu (India); Ramachandran, Suja [Electronics, Instrumentation and Radiological Safety Group (EIRSG), Indira Gandhi Centre for Atomic Research (IGCAR), Kalpakkam, Tamil Nadu (India); Rathakrishnan, S. [Reactor Physics Section, Madras Atomic Power Station (MAPS), Kalpakkam, Tamil Nadu (India); Satya Murty, S.A.V. [Electronics, Instrumentation and Radiological Safety Group (EIRSG), Indira Gandhi Centre for Atomic Research (IGCAR), Kalpakkam, Tamil Nadu (India); Sai Baba, M. [Resources Management Group (RMG), Indira Gandhi Centre for Atomic Research (IGCAR), Kalpakkam, Tamil Nadu (India)

    2015-01-15

    Highlights: • We study and compare Genetic Algorithms (GA) in the fuel bundle burnup optimization of an Indian Pressurized Heavy Water Reactor (PHWR) of 220 MWe. • Two Genetic Algorithm methodologies namely, Penalty Functions based GA and Multi Objective GA are considered. • For the selected problem, Multi Objective GA performs better than Penalty Functions based GA. • In the present study, Multi Objective GA outperforms Penalty Functions based GA in convergence speed and better diversity in solutions. - Abstract: The work carried out as a part of application and comparison of GA techniques in nuclear reactor environment is presented in the study. The nuclear fuel management optimization problem selected for the study aims at arriving appropriate reference discharge burnup values for the two burnup zones of 220 MWe Pressurized Heavy Water Reactor (PHWR) core. Two Genetic Algorithm methodologies namely, Penalty Functions based GA and Multi Objective GA are applied in this study. The study reveals, for the selected problem of PHWR fuel bundle burnup optimization, Multi Objective GA is more suitable than Penalty Functions based GA in the two aspects considered: by way of producing diverse feasible solutions and the convergence speed being better, i.e. it is capable of generating more number of feasible solutions, from earlier generations. It is observed that for the selected problem, the Multi Objective GA is 25.0% faster than Penalty Functions based GA with respect to CPU time, for generating 80% of the population with feasible solutions. When average computational time of fixed generations are considered, Penalty Functions based GA is 44.5% faster than Multi Objective GA. In the overall performance, the convergence speed of Multi Objective GA surpasses the computational time advantage of Penalty Functions based GA. The ability of Multi Objective GA in producing more diverse feasible solutions is a desired feature of the problem selected, that helps the

  17. OECD/NEA burnup credit calculational criticality benchmark Phase I-B results

    Energy Technology Data Exchange (ETDEWEB)

    DeHart, M.D.; Parks, C.V. [Oak Ridge National Lab., TN (United States); Brady, M.C. [Sandia National Labs., Las Vegas, NV (United States)

    1996-06-01

    In most countries, criticality analysis of LWR fuel stored in racks and casks has assumed that the fuel is fresh with the maximum allowable initial enrichment. This assumption has led to the design of widely spaced and/or highly poisoned storage and transport arrays. If credit is assumed for fuel burnup, initial enrichment limitations can be raised in existing systems, and more compact and economical arrays can be designed. Such reliance on the reduced reactivity of spent fuel for criticality control is referred to as burnup credit. The Burnup Credit Working Group, formed under the auspices of the Nuclear Energy Agency of the Organization for Economic Cooperation and Development, has established a set of well-defined calculational benchmarks designed to study significant aspects of burnup credit computational methods. These benchmarks are intended to provide a means for the intercomparison of computer codes, methods, and data applied in spent fuel analysis. The benchmarks have been divided into multiple phases, each phase focusing on a particular feature of burnup credit analysis. This report summarizes the results and findings of the Phase I-B benchmark, which was proposed to provide a comparison of the ability of different code systems and data libraries to perform depletion analysis for the prediction of spent fuel isotopic concentrations. Results included here represent 21 different sets of calculations submitted by 16 different organizations worldwide and are based on a limited set of nuclides determined to have the most important effect on the neutron multiplication factor of light-water-reactor spent fuel. A comparison of all sets of results demonstrates that most methods agree to within 10% in the ability to estimate the spent fuel concentrations of most actinides. All methods agree within 11% about the average for all fission products studied. Most deviations are less than 10%, and many are less than 5%. The exceptions are Sm 149, Sm 151, and Gd 155.

  18. High Burnup Dry Storage Cask Research and Development Project, Final Test Plan

    Energy Technology Data Exchange (ETDEWEB)

    None

    2014-02-27

    EPRI is leading a project team to develop and implement the first five years of a Test Plan to collect data from a SNF dry storage system containing high burnup fuel.12 The Test Plan defined in this document outlines the data to be collected, and the storage system design, procedures, and licensing necessary to implement the Test Plan.13 The main goals of the proposed test are to provide confirmatory data14 for models, future SNF dry storage cask design, and to support license renewals and new licenses for ISFSIs. To provide data that is most relevant to high burnup fuel in dry storage, the design of the test storage system must mimic real conditions that high burnup SNF experiences during all stages of dry storage: loading, cask drying, inert gas backfilling, and transfer to the ISFSI for multi-year storage.15 Along with other optional modeling, SETs, and SSTs, the data collected in this Test Plan can be used to evaluate the integrity of dry storage systems and the high burnup fuel contained therein over many decades. It should be noted that the Test Plan described in this document discusses essential activities that go beyond the first five years of Test Plan implementation.16 The first five years of the Test Plan include activities up through loading the cask, initiating the data collection, and beginning the long-term storage period at the ISFSI. The Test Plan encompasses the overall project that includes activities that may not be completed until 15 or more years from now, including continued data collection, shipment of the Research Project Cask to a Fuel Examination Facility, opening the cask at the Fuel Examination Facility, and examining the high burnup fuel after the initial storage period.

  19. Technical Basis for Peak Reactivity Burnup Credit for BWR Spent Nuclear Fuel in Storage and Transportation Systems

    Energy Technology Data Exchange (ETDEWEB)

    Marshall, William BJ J [ORNL; Ade, Brian J [ORNL; Bowman, Stephen M [ORNL; Gauld, Ian C [ORNL; Ilas, Germina [ORNL; Mertyurek, Ugur [ORNL; Radulescu, Georgeta [ORNL

    2015-01-01

    Oak Ridge National Laboratory and the United States Nuclear Regulatory Commission have initiated a multiyear project to investigate application of burnup credit for boiling-water reactor (BWR) fuel in storage and transportation casks. This project includes two phases. The first phase (1) investigates applicability of peak reactivity methods currently used in spent fuel pools (SFPs) to storage and transportation systems and (2) evaluates validation of both reactivity (keff) calculations and burnup credit nuclide concentrations within these methods. The second phase will focus on extending burnup credit beyond peak reactivity. This paper documents the first phase, including an analysis of lattice design parameters and depletion effects, as well as both validation components. Initial efforts related to extended burnup credit are discussed in a companion paper. Peak reactivity analyses have been used in criticality analyses for licensing of BWR fuel in SFPs over the last 20 years. These analyses typically combine credit for the gadolinium burnable absorber present in the fuel with a modest amount of burnup credit. Gadolinium burnable absorbers are used in BWR assemblies to control core reactivity. The burnable absorber significantly reduces assembly reactivity at beginning of life, potentially leading to significant increases in assembly reactivity for burnups less than 15–20 GWd/MTU. The reactivity of each fuel lattice is dependent on gadolinium loading. The number of gadolinium-bearing fuel pins lowers initial lattice reactivity, but it has a small impact on the burnup and reactivity of the peak. The gadolinium concentration in each pin has a small impact on initial lattice reactivity but a significant effect on the reactivity of the peak and the burnup at which the peak occurs. The importance of the lattice parameters and depletion conditions are primarily determined by their impact on the gadolinium depletion. Criticality code validation for BWR burnup

  20. Group Constants Generation of the Pseudo Fission Products for Fast Reactor Burnup Calculations

    Science.gov (United States)

    Gil, Choong-Sup; Kim, Do Heon; Chang, Jonghwa

    2005-05-01

    The pseudo fission products for the burnup calculations of the liquid metal fast reactor were generated. The cross-section data and fission product yield data of ENDF/B-VI were used for the pseudo fission product data of U-235, U-238, Pu-239, Pu-240, Pu-241, and Pu-242. The pseudo fission product data can be used with the KAFAX-F22 or -E66, which are the MATXS-format libraries for analyses of the liquid metal fast reactor at KAERI and were distributed through the OECD/NEA. The 80-group MATXS-format libraries of the 172 fission products were generated and the burnup chains for generation of the pseudo fission products were prepared.

  1. Draft evaluation of the frequency for gas sampling for the high burnup confirmatory data project

    Energy Technology Data Exchange (ETDEWEB)

    Stockman, Christine T. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Alsaed, Halim A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Bryan, Charles R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-03-26

    This report fulfills the M3 milestone M3FT-15SN0802041, “Draft Evaluation of the Frequency for Gas Sampling for the High Burn-up Storage Demonstration Project” under Work Package FT-15SN080204, “ST Field Demonstration Support – SNL”. This report provides a technically based gas sampling frequency strategy for the High Burnup (HBU) Confirmatory Data Project. The evaluation of: 1) the types and magnitudes of gases that could be present in the project cask and, 2) the degradation mechanisms that could change gas compositions culminates in an adaptive gas sampling frequency strategy. This adaptive strategy is compared against the sampling frequency that has been developed based on operational considerations. Gas sampling will provide information on the presence of residual water (and byproducts associated with its reactions and decomposition) and breach of cladding, which could inform the decision of when to open the project cask.

  2. Analysis of simulated high burnup nuclear fuel by laser induced breakdown spectroscopy

    Science.gov (United States)

    Singh, Manjeet; Sarkar, Arnab; Banerjee, Joydipta; Bhagat, R. K.

    2017-06-01

    Advanced Heavy Water Reactor (AHWR) grade (Th-U)O2 fuel sample and Simulated High Burn-Up Nuclear Fuels (SIMFUEL) samples mimicking the 28 and 43 GWd/Te irradiated burn-up fuel were studied using laser-induced breakdown spectroscopy (LIBS) setup in a simulated hot-cell environment from a distance of > 1.5 m. Resolution of 60 emission lines of fission products was identified. Among them only a few emission lines were found to generate calibration curves. The study demonstrates the possibility to investigate impurities at concentrations around hundreds of ppm, rapidly at atmospheric pressure without any sample preparation. The results of Ba and Mo showed the advantage of LIBS analysis over traditional methods involving sample dissolution, which introduces possible elemental loss. Limits of detections (LOD) under Ar atmosphere shows significant improvement, which is shown to be due to the formation of stable plasma.

  3. Experience with incomplete control rod insertion in fuel with burnup exceeding approximately 40 GWD/MTU

    Energy Technology Data Exchange (ETDEWEB)

    Kee, E. [Houston Lighting & Power Co., Wadworth, TX (United States)

    1997-01-01

    Analysis and measurement experience with fuel assemblies having incomplete control rod insertion at burnups of approximately 40 GWD/MTU is presented. Control rod motion dynamics and simplified structural analyses are presented and compared to measurement data. Fuel assembly growth measurements taken with the plant Refueling Machine Z-Tape are described and presented. Bow measurements (including plug gauging) are described and potential improvements are suggested. The measurements described and analysis performed show that sufficient guide tube bow (either from creep or yield buckling) is present in some high burnup assemblies to stop the control rods before they reach their full limit of travel. Recommendations are made that, if implemented, could improve cost performance related to testing and analysis activities.

  4. The Impact of Operating Parameters and Correlated Parameters for Extended BWR Burnup Credit

    Energy Technology Data Exchange (ETDEWEB)

    Ade, Brian J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Marshall, William B. J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Ilas, Germina [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Betzler, Benjamin R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Bowman, Stephen M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-06-01

    Applicants for certificates of compliance for spent nuclear fuel (SNF) transportation and dry storage systems perform analyses to demonstrate that these systems are adequately subcritical per the requirements of Title 10 of the Code of Federal Regulations (10 CFR) Parts 71 and 72. For pressurized water reactor (PWR) SNF, these analyses may credit the reduction in assembly reactivity caused by depletion of fissile nuclides and buildup of neutron-absorbing nuclides during power operation. This credit for reactivity reduction during depletion is commonly referred to as burnup credit (BUC). US Nuclear Regulatory Commission (NRC) staff review BUC analyses according to the guidance in the Division of Spent Fuel Storage and Transportation Interim Staff Guidance (ISG) 8, Revision 3, Burnup Credit in the Criticality Safety Analyses of PWR Spent Fuel in Transportation and Storage Casks.

  5. EPRI/DOE High Burnup Fuel Sister Pin Test Plan Simplification and Visualization

    Energy Technology Data Exchange (ETDEWEB)

    Saltzstein, Sylvia J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Sorenson, Ken B. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hanson, Brady [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Billone, Mike [Argonne National Lab. (ANL), Argonne, IL (United States); Scaglione, John [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Montgomery, Rose [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Bevard, Bruce [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-07-01

    The EPRI/DOE High Burnup Confirmatory Data Project (herein called the "Demo") is a multi-year, multi-entity confirmation demonstration test with the purpose of providing quantitative and qualitative data to show how high-burnup fuel ages in dry storage over a ten-year period. The Demo involves obtaining 32 assemblies of high-burnup PWR fuel of four common cladding alloys from the North Anna Nuclear Power Plant, drying them according to standard plant procedures, and then storing them in an NRC-licensed TN-3 2B cask on the North Anna dry storage pad for ten years. After the ten-year storage time, the cask will be opened and the rods will be examined for signs of aging. Twenty-five rods from assemblies of similar claddings, in-reactor placement, and burnup histories (herein called "sister rods") have been shipped from the North Anna Nuclear Power Plant and are currently being nondestructively tested at Oak Ridge National Laboratory. After the non-destructive testing has been completed for each of the twenty-five rods, destructive analysis will be performed at ORNL, PNNL, and ANL to obtain mechanical data. Opinions gathered from the expert interviews, ORNL and PNNL Sister Rod Test Plans, and numerous meetings has resulted in the Simplified Test Plan described in this document. Some of the opinions and discussions leading to the simplified test plan are included here. Detailed descriptions and background are in the ORNL and PNNL plans in the appendices . After the testing described in this simplified test plan h as been completed , the community will review all the collected data and determine if additional testing is needed.

  6. Burn-up credit in criticality safety of PWR spent fuel

    Energy Technology Data Exchange (ETDEWEB)

    Mahmoud, Rowayda F., E-mail: Rowayda_mahmoud@yahoo.com [Metallurgy Department, Nuclear Research Center, Atomic Energy Authority (Egypt); Shaat, Mohamed K. [Nuclear Engineering, Reactors Department, Nuclear Research Center, Atomic Energy Authority (Egypt); Nagy, M.E.; Agamy, S.A. [Professor of Nuclear Engineering, Nuclear and Radiation Department, Alexandria University (Egypt); Abdelrahman, Adel A. [Metallurgy Department, Nuclear Research Center, Atomic Energy Authority (Egypt)

    2014-12-15

    Highlights: • Designing spent fuel wet storage using WIMS-5D and MCNP-5 code. • Studying fresh and burned fuel with/out absorber like “B{sub 4}C and Ag–In–Cd” in racks. • Sub-criticality was confirmed for fresh and burned fuel under specific cases. • Studies for BU credit recommend increasing fuel burn-up to 60.0 GWD/MTU. • Those studies require new core structure materials, fuel composition and cladding. - Abstract: The criticality safety calculations were performed for a proposed design of a wet spent fuel storage pool. This pool will be used for the storage of spent fuel discharged from a typical pressurized water reactor (PWR). The mathematical model based on the international validated codes, WIMS-5 and MCNP-5 were used for calculating the effective multiplication factor, k{sub eff}, for the spent fuel stored in the pool. The data library for the multi-group neutron microscopic cross-sections was used for the cell calculations. The k{sub eff} was calculated for several changes in water density, water level, assembly pitch and burn-up with different initial fuel enrichment and new types and amounts of fixed absorbers. Also, k{sub eff} was calculated for the conservative fresh fuel case. The results of the calculations confirmed that the effective multiplication factor for the spent fuel storage is sub-critical for all normal and abnormal states. The future strategy for the burn-up credit recommends increasing the fuel burn-up to a value >60.0 GWD/MTU, which requires new fuel composition and new fuel cladding material with the assessment of the effects of negative reactivity build up.

  7. Evaluation of Fission Product Critical Experiments and Associated Biases for Burnup Credit Validation

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, Don [ORNL; Rearden, Bradley T [ORNL; Reed, Davis Allan [ORNL

    2010-01-01

    One of the challenges associated with implementation of burnup credit is the validation of criticality calculations used in the safety evaluation; in particular the availability and use of applicable critical experiment data. The purpose of the validation is to quantify the relationship between reality and calculated results. Validation and determination of bias and bias uncertainty require the identification of sets of critical experiments that are similar to the criticality safety models. A principal challenge for crediting fission products (FP) in a burnup credit safety evaluation is the limited availability of relevant FP critical experiments for bias and bias uncertainty determination. This paper provides an evaluation of the available critical experiments that include FPs, along with bounding, burnup-dependent estimates of FP biases generated by combining energy dependent sensitivity data for a typical burnup credit application with the nuclear data uncertainty information distributed with SCALE 6. A method for determining separate bias and bias uncertainty values for individual FPs and illustrative results is presented. Finally, a FP bias calculation method based on data adjustment techniques and reactivity sensitivity coefficients calculated with the SCALE sensitivity/uncertainty tools and some typical results is presented. Using the methods described in this paper, the cross-section bias for a representative high-capacity spent fuel cask associated with the ENDF/B-VII nuclear data for 16 most important stable or near stable FPs is predicted to be no greater than 2% of the total worth of the 16 FPs, or less than 0.13 % k/k.

  8. Evaluation of the Frequency for Gas Sampling for the High Burnup Confirmatory Data Project

    Energy Technology Data Exchange (ETDEWEB)

    Stockman, Christine T. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Alsaed, Halim A. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Bryan, Charles R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Marschman, Steven C. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Scaglione, John M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-05-01

    This report provides a technically based gas sampling frequency strategy for the High Burnup (HBU) Confirmatory Data Project. The evaluation of: 1) the types and magnitudes of gases that could be present in the project cask and, 2) the degradation mechanisms that could change gas compositions culminates in an adaptive gas sampling frequency strategy. This adaptive strategy is compared against the sampling frequency that has been developed based on operational considerations.

  9. Analysis of the effect of UO{sub 2} high burnup microstructure on fission gas release

    Energy Technology Data Exchange (ETDEWEB)

    Jernkvist, Lars Olof; Massih, Ali [Quantum Technologies AB, Uppsala Science Park (Sweden)

    2002-10-01

    This report deals with high-burnup phenomena with relevance to fission gas release from UO{sub 2} nuclear fuel. In particular, we study how the fission gas release is affected by local buildup of fissile plutonium isotopes and fission products at the fuel pellet periphery, with subsequent formation of a characteristic high-burnup rim zone micro-structure. An important aspect of these high-burnup effects is the degradation of fuel thermal conductivity, for which prevalent models are analysed and compared with respect to their theoretical bases and supporting experimental data. Moreover, the Halden IFA-429/519.9 high-burnup experiment is analysed by use of the FRAPCON3 computer code, into which modified and extended models for fission gas release are introduced. These models account for the change in Xe/Kr-ratio of produced and released fission gas with respect to time and space. In addition, several alternative correlations for fuel thermal conductivity are implemented, and their impact on calculated fission gas release is studied. The calculated fission gas release fraction in IFA-429/519.9 strongly depends on what correlation is used for the fuel thermal conductivity, since thermal release dominates over athermal release in this particular experiment. The conducted calculations show that athermal release processes account for less than 10% of the total gas release. However, athermal release from the fuel pellet rim zone is presumably underestimated by our models. This conclusion is corroborated by comparisons between measured and calculated Xe/Kr-ratios of the released fission gas.

  10. Advanced Corrosion-Resistant Zr Alloys for High Burnup and Generation IV Applications

    Energy Technology Data Exchange (ETDEWEB)

    Arthur Motta; Yong Hwan Jeong; R.J. Comstock; G.S. Was; Y.S. Kim

    2006-10-31

    The objective of this collaboration between four institutions in the US and Korea is to demonstrate a technical basis for the improvement of the corrosion resistance of zirconium-based alloys in more extreme operating environments (such as those present in severe fuel duty,cycles (high burnup, boiling, aggressive chemistry) andto investigate the feasibility (from the point of view of corrosion rate) of using advanced zirconium-based alloys in a supercritical water environment.

  11. Investigation of very high burnup UO{sub 2} fuels in Light Water Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Cappia, Fabiola

    2017-03-27

    Historically, the average discharge burnup of Light Water Reactor (LWR) fuel has increased almost continuously. On one side, increase in the average discharge burnup is attractive because it contributes to decrease part of the fuel cycle costs. On the other side, it raises the practical problem of predicting the performance, longevity and properties of reactor fuel elements upon accumulation of irradiation damage and fission products both during in-reactor operation and after discharge. Performance of the fuel and structural components of the core is one of the critical areas on which the economic viability and public acceptance of nuclear energy production hinges. Along the pellet radius, the fuel matrix is subjected to extremely heterogeneous alteration and damage, as a result of temperature and burnup gradients. In particular, in the peripheral region of LWR UO{sub 2} fuel pellets, when the local burnup exceeds 50-70 GWd/tHM, a microstructural transformation starts to take place, as a consequence of enhanced accumulation of radiation damage, fission products and limited thermal recovery. The newly formed structure is commonly named High Burnup Structure (HBS). The HBS is characterised by three main features: (a) formation of submicrometric grains from the original grains, (b) depletion of fission gas from the fuel matrix, (c) steep increase in the porosity, which retains most of the gas depleted from the fuel matrix. The last two aspects rose significant attention because of the important impact of the fission gas behaviour on integral fuel performance. The porosity increase controls the gas-driven swelling, worsening the cladding loading once the fuel-cladding gap is closed. Another concern is that the large retention of fission gas within the HBS could lead to significant release at high burnups through the degradation of thermal conductivity or contribute to fuel pulverisation during accidental conditions. Need of more experimental investigations about the

  12. Estimation of the Fuel Depletion Code Bias and Uncertainty in Burnup-Credit Criticality Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jong Woon; Cho, Nam Zin [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of); Lee, Sang Jin; Bae, Chang Yeal [Nuclear Environment Technology Institute, Taejon (Korea, Republic of)

    2006-07-01

    In the past, criticality safety analyses for commercial light-water-reactor (LWR) spent nuclear fuel (SNF) storage and transportation canisters assumed the spent fuel to be fresh (unirradiated) fuel with uniform isotopic compositions. This fresh-fuel assumption provides a well-defined, bounding approach to the criticality safety analysis that eliminates concerns related to the fuel operating history, and thus considerably simplifies the safety analysis. However, because this assumption ignores the inherent decrease in reactivity as a result of irradiation, it is very conservative. The concept of taking credit for the reduction in reactivity due to fuel burnup is commonly referred to as burnup credit. Implementation of burnup credit requires the computational prediction of the nuclide inventories (compositions) for the dominant fissile and absorbing nuclide species in spent fuel. In addition to that, the bias and uncertainty in the predicted concentration of all nuclides used in the analysis be established by comparisons of calculated and measured radiochemical assay data. In this paper, three methods for considering the bias and uncertainty will be reviewed. The estimated bias and uncertainty that the results of 3rd method are presented.

  13. Criticality Uncertainty Analysis of Spent Fuel Transport Cask applying Burnup Credit

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Gang Ug; Park, Jae Ho; Kim, Do Hyun [Korea Nuclear Engineering and Service Corp, Daejeon (Korea, Republic of); Kim, Tae Man; Yoon, Jeong Hyun [Korea Radioactive Waste Management Corporation, Daejeon (Korea, Republic of)

    2011-09-15

    In general, conventional criticality analyses for spent fuel transport/dry storage systems have been performed based on assumption of fresh fuel concerning the potential uncertainties from number density calculation of Transuranic and Fission Products in spent fuel. However, because of economic loss due to the excessive criticality margin, recently the design of transport/dry storage systems with Burnup Credit(BUC) application has been actively developed. The uncertainties in criticality analyses on transport/storage systems with BUC technique show strong dependence upon initial enrichment and burnup rate, whereas those in the conventional criticality evaluation based on fresh fuel assumption do not show such a dependence. In this study, regulatory-required uncertainties of the criticality analyses for BK 26 Cask, which is conceptually designed spent fuel transport cask with BUC corresponding to the limiting circumstances on nuclear power plants in Korea, are evaluated as a function of initial enrichment and burnup rate. Results of this study will be used as basic data for spent fuel loading curve of BK 26 Cask.

  14. AREVA NP burnup credit investigation on irradiated MOX fuel within the REBUS BWR programme

    Energy Technology Data Exchange (ETDEWEB)

    Alander, Alexandra; Misu, Stefan; Timm, Wolf [AREVA, AREVA NP, Erlangen (Germany); Thareau, Sebastien [AREVA, AREVA NP, Paris (France)

    2008-07-01

    The present paper summarizes a criticality and burnup credit investigation carried out using the 2D spectral codes CASMO-4 and APOLLO2-A. Fission rate distributions and multiplication factors, for UOX and MOX configurations, are calculated as well as the reactivity effect caused by burnup on a selection of irradiated MOX fuel assemblies. 3D core criticality calculations were carried out with the Monte Carlo transport code MOCA and the deterministic transport code VARIANT (a nodal code developed by ANL) using CASMO-4 generated cross section libraries. Calculations were compared to experimental data from the critical facility VENUS in the context of the REBUS BWR Programme. The results confirm that the spectral codes CASMO-4 and APOLLO2-A are well suited to calculate fission rates, multiplication factors and reactivity effects. It is also found that the calculated burnup reactivity effect, using CASMO-4 generated cross sections and the best 3D method (MOCA), is underestimated by merely 7% compared to the experimental value, which can mainly be attributed to the simplifications done in order to model the critical configurations with reasonable efforts. (authors)

  15. High burnup fuel onset conditions in dry storage. Prediction of EOL rod internal pressure

    Energy Technology Data Exchange (ETDEWEB)

    Feria, F.; Herranz, L.E.

    2015-07-01

    During dry storage, cladding resistance to failure can be affected by several degrading mechanisms like creep or hydrides radial reorientation. The driving force of these effects is the stress at which the cladding is submitted. The maximum stress in the cladding is determined by the end-of-reactor-life (EOL) rod internal pressure, PEOL, at the maximum temperature attained during dry storage. Thus, PEOL sets the initial conditions of storage for potential time-dependent changes in the cladding. Based on FRAPCON-3.5 calculations, the aim of this work is to analyse the PEOL of a PWR fuel rod irradiated to burnups greater than 60 GWd/tU, where limited information is available. In order to be conservative, demanding irradiation histories have been used with a peak linear power of 44 kW/m. FRAPCON-3.5 results show an increasing exponential trend of PEOL with burnup, from which a simple correlation has been derived. The comparison with experimental data found in the literature confirms the enveloping nature of the predicted curve. Based on that, a conservative prediction of cladding stress in dry storage has been obtained. The comparison with a critical stress threshold related to hydrides embrittlement seems to point out that this issue should not be a concern at burnups below 65 GWd/tU. (Author)

  16. Burnup simulations of different fuel grades using the MCNPX Monte Carlo code

    Directory of Open Access Journals (Sweden)

    Asah-Opoku Fiifi

    2014-01-01

    Full Text Available Global energy problems range from the increasing cost of fuel to the unequal distribution of energy resources and the potential climate change resulting from the burning of fossil fuels. A sustainable nuclear energy would augment the current world energy supply and serve as a reliable future energy source. This research focuses on Monte Carlo simulations of pressurized water reactor systems. Three different fuel grades - mixed oxide fuel (MOX, uranium oxide fuel (UOX, and commercially enriched uranium or uranium metal (CEU - are used in this simulation and their impact on the effective multiplication factor (Keff and, hence, criticality and total radioactivity of the reactor core after fuel burnup analyzed. The effect of different clad materials on Keff is also studied. Burnup calculation results indicate a buildup of plutonium isotopes in UOX and CEU, as opposed to a decline in plutonium radioisotopes for MOX fuel burnup time. For MOX fuel, a decrease of 31.9% of the fissile plutonium isotope is observed, while for UOX and CEU, fissile plutonium isotopes increased by 82.3% and 83.8%, respectively. Keff results show zircaloy as a much more effective clad material in comparison to zirconium and stainless steel.

  17. Preparation of higher-actinide burnup and cross section samples. [LMFBR

    Energy Technology Data Exchange (ETDEWEB)

    Adair, H.L.; Kobisk, E.H.; Quinby, T.C.; Thomas, D.K.; Dailey, J.M.

    1981-01-01

    A joint research program involving the United States and the United Kingdom was instigated about four years ago for the purpose of studying burnup of higher actinides using in-core irradiation in the fast reactor at Dounreay, Scotland. Simultaneously, determination of cross sections of a wide variety of higher actinide isotopes was proposed. Coincidental neutron flux and energy spectral measurements were to be made using vanadium encapsulated dosimetry materials in the immediate region of the burnup and cross section samples. The higher actinide samples chosen for the burnup study were /sup 241/Am and /sup 244/Cm in the forms of Am/sub 2/O/sub 3/, Cm/sub 2/O/sub 3/, and Am/sub 6/ Cm(RE)/sub 7/O/sub 21/, where (RE) represents a mixture of lanthanide sesquioxides. It is the purpose of this paper to describe technology development and its application in the preparation of the fuel specimens and the cross section specimens that are being used in this cooperative program.

  18. Needs of reliable nuclear data and covariance matrices for Burnup Credit in JEFF-3 library

    Directory of Open Access Journals (Sweden)

    Lecarpentier D.

    2013-03-01

    Full Text Available Burnup Credit (BUC is the concept which consists in taking into account credit for the reduction of nuclear spent fuel reactivity due to its burnup. In the case of PWR-MOx spent fuel, studies pointed out that the contribution of the 15 most absorbing, stable and non-volatile fission products selected to the credit is as important as the one of the actinides. In order to get a “best estimate” value of the keff, biases of their inventory calculation and individual reactivity worth should be considered in criticality safety studies. This paper enhances the most penalizing bias towards criticality and highlights possible improvements of nuclear data for the 15 FPs of PWRMOx BUC. Concerning the fuel inventory, trends in function of the burnup can be derived from experimental validation of the DARWIN-2.3 package (using the JEFF-3.1.1/SHEM library. Thanks to the BUC oscillation programme of separated FPs in the MINERVE reactor and fully validated scheme PIMS, calculation over experiment ratios can be accurately transposed to tendencies on the FPs integral cross sections.

  19. Study on nuclear physics of high burn-up full MOX-BWR core

    Energy Technology Data Exchange (ETDEWEB)

    Shirakawa, Toshihisa; Okubo, Tsutomu; Ochiai, Masa-aki [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1998-08-01

    In this report, neutronics study of full Mixed-oxide (MOX) high burn-up BWR core is presented. Our design goals are about 3-year cycle length, four-batch refueling scheme and more than 100GWd/t fuel discharge burn-up. Base core configuration is 1,350MWe US version of ABWR with 9 x 9 type fuel assembly. Investigation of the reactor core has been carried out by arranging Gd{sub 2}O{sub 3} contents in fuel rods and changing water to fuel volume ratio (V{sub m}/V{sub f}) through the number of water rods or adjustment of fuel clad diameter. JAERI`s general purpose neutronics code system SRAC95 was used for two dimensional XY fuel assembly cell neutronics calculations. Calculated cases are for a comparatively high moderated fuel assembly with 9 water rods, a fuel assembly without water rods and a comparatively low moderated fuel assembly without water rods and with larger fuel clad diameter. All these 3 cases seem to achieve our design goals mentioned above. For the last case, three dimensional core burn-up calculation was performed by this code system. This case seems to attain a low linear power density and the operation with all control rod out. (author)

  20. Study on nuclear physics of high burnup full MOX PWR core

    Energy Technology Data Exchange (ETDEWEB)

    Kugo, Teruhiko; Shimada, Syoichiro; Okubo, Tsutomu; Ochiai, Masaaki [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1998-10-01

    As one of options for future light water reactors, we have been studying a new concept of a high burnup full MOX PWR core. We have proposed a core of 600 MWe to ensure discharged burnup of 100 GWd/t by increasing a moderator to fuel volume ratio to 2.6 with enlarged fuel pin pitch of 13.8 mm, and have investigated its feasibility in neutronics. A plutonium fissile content of 12% is needed for this core. A soluble boric acid with B-10 enrichment of 40% is able to control burnup reactivity without increasing a capacity of boron tanks. A control rod cluster with use of natural boron carbide (B{sub 4}C) per three fuel assemblies ensures a shutdown margin of more than 2%dk/kk`. A moderator temperature and void coefficients are negative through an operating cycle. Although the use of burnable poisons like Gd{sub 2}O{sub 3} and Er{sub 2}O{sub 3} is not necessary to reduce an excess reactivity, it can lower a radial power peaking factor by about 0.1. (author)

  1. High burnup performance of Mg, Mg-Nb and Ti doped UO{sub 2} fuels

    Energy Technology Data Exchange (ETDEWEB)

    Shiratori, Tetsuo; Serizawa, Hiroyuki; Fukuda, Kousaku [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Fujino, Takeo; Sato, Nobuaki; Yamada, Kohta [Institute for Advanced Materials Processing, Tohoku Univ., Sendai, Miyagi (Japan)

    2000-09-01

    In order to control irradiation performance of fuel swelling and FP gas release etc. at high burnups of light water reactor fuels, doped UO{sub 2} pellet fuels were prepared and their irradiation behavior was examined. The UO{sub 2} pellets doped 2.5 to 15mol%Mg, 5mol%Mg - 5mol%Nb, and 3.5mol%Ti and undoped UO{sub 2} pellets as a reference fuel were loaded together in a capsule and irradiated to the maximum burnups of 94GWd/t(U) below temperature of 1000degC in the JRR-3M reactor of JAERI. As results of post-irradiation examinations such as visual inspection, dimensional and density change measurements, thermal diffusivity and ceramography with optical microscope and EPMA, no difference was observed between the doped and the reference UO{sub 2} fuels. And valuable results were obtained on high burnup properties for swelling rates, thermal conductivities, structure changes and so on. (author)

  2. Thermal Hydraulic Analysis of 3 MW TRIGA Research Reactor of Bangladesh Considering Different Cycles of Burnup

    Directory of Open Access Journals (Sweden)

    M.H. Altaf

    2014-12-01

    Full Text Available Burnup dependent steady state thermal hydraulic analysis of TRIGA Mark-II research reactor has been carried out utilizing coupled point kinetics, neutronics and thermal hydraulics code EUREKA-2/RR. From the previous calculations of neutronics parameters including percentage burnup of individual fuel elements performed so far for 700 MWD burnt core of TRIGA reactor showed that the fuel rod predicted as hottest at the beginning of cycle (fresh core was found to remain as the hottest until 200 MWD of burn, but, with the progress of core burn, the hottest rod was found to be shifted and another rod in the core became the hottest. The present study intends to evaluate the thermal hydraulic parameters of these hottest fuel rods at different cycles of burnup, from beginning to 700 MWD core burnt considering reactor operates under steady state condition. Peak fuel centerline temperature, maximum cladding and coolant temperatures of the hottest channels were calculated. It revealed that maximum temperature reported for fuel clad and fuel centerline found to lie below their melting points which indicate that there is no chance of burnout on the fuel cladding surface and no blister in the fuel meat throughout the considered cycles of core burnt.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-06-01

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

  4. Underestimation of nuclear fuel burnup – theory, demonstration and solution in numerical models

    Directory of Open Access Journals (Sweden)

    Gajda Paweł

    2016-01-01

    Full Text Available Monte Carlo methodology provides reference statistical solution of neutron transport criticality problems of nuclear systems. Estimated reaction rates can be applied as an input to Bateman equations that govern isotopic evolution of reactor materials. Because statistical solution of Boltzmann equation is computationally expensive, it is in practice applied to time steps of limited length. In this paper we show that simple staircase step model leads to underprediction of numerical fuel burnup (Fissions per Initial Metal Atom – FIMA. Theoretical considerations indicates that this error is inversely proportional to the length of the time step and origins from the variation of heating per source neutron. The bias can be diminished by application of predictor-corrector step model. A set of burnup simulations with various step length and coupling schemes has been performed. SERPENT code version 1.17 has been applied to the model of a typical fuel assembly from Pressurized Water Reactor. In reference case FIMA reaches 6.24% that is equivalent to about 60 GWD/tHM of industrial burnup. The discrepancies up to 1% have been observed depending on time step model and theoretical predictions are consistent with numerical results. Conclusions presented in this paper are important for research and development concerning nuclear fuel cycle also in the context of Gen4 systems.

  5. OECD/NEA burnup credit criticality benchmark. Result of phase IIA

    Energy Technology Data Exchange (ETDEWEB)

    Takano, Makoto; Okuno, Hiroshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1996-02-01

    The report describes the final result of the Phase IIA of the Burnup Credit Criticality Benchmark conducted by OECD/NEA. In the Phase IIA benchmark problems, the effect of an axial burnup profile of PWR spent fuels on criticality (end effect) has been studied. The axial profiles at 10, 30 and 50 GWd/t burnup have been considered. In total, 22 results from 18 institutes of 10 countries have been submitted. The calculated multiplication factors from the participants have lain within the band of {+-} 1% {Delta}k. For the irradiation up to 30 GWd/t, the end effect has been found to be less than 1.0% {Delta}k. But, for the 50 GWd/t case, the effect is more than 4.0% {Delta}k when both actinides and FPs are taken into account, whereas it remains less than 1.0% {Delta}k when only actinides are considered. The fission density data have indicated the importance end regions have in the criticality safety analysis of spent fuel systems. (author).

  6. Preliminary 3D burn-up analysis of the HPLWR core

    Energy Technology Data Exchange (ETDEWEB)

    Monti, Lanfranco; Gabrielli, Fabrizio; Schulenberg, Thomas [Forschungszentrum Karlsruhe (Germany). Inst. for Nuclear and Energy Technologies

    2009-07-01

    The High Performance Light Water Reactor (HPLWR) is an innovative reactor concept cooled and moderated with water at supercritical pressure (25 MPa) whose feasibility is analyzed within a European framework [1]. The pronounced variation in water density, which takes place inside the core, is due to the coolant heat up from 550 K to 800 K and is supposed to generate pronounced 3D effects during reactor operation because the different core regions have different flux amplitude and neutron spectrum. Open questions are how k{sub eff} and the power-map will change during the burn-up and require a 3D multi-zone burn-up analysis of the core. This goal is achieved using the ERANOS system [2, 3], which is a deterministic tool for neutronic core analyses. The starting condition is taken from a neutronic/thermal-hydraulic coupled solution of the whole core [4], which does not yet include any fuel enrichment optimization nor reactivity control systems, i.e. control rods or burnable poisons. Uranium dioxide enriched to 5wt% in {sup 235}U is used as starting fuel while typical LWRs evolution chains for actinides and fission products have been selected. The core nodalization used in the coupled system is also adopted for multi-zone burn-up analysis: there are 462 zones with different material composition, 21 in axial direction and 22 in the horizontal plane. A burn-up period of 200 days ({approx_equal}6400 MWd/tHM) is considered here and has been divided into two different smaller time steps: 1) an inner time step at which macroscopic cross-sections (XSs) and the flux normalization are calculated according to the change in fuel isotopic composition; 2) an outer time step at which whole core flux calculations are performed to evaluate the region-wise neutron flux distribution. The length of the flux calculation time step has to be short enough to avoid unphysical power-shape oscillations, as underlined by Reiss et al. [5] with a different computational approach. The 40 groups

  7. Microhardness and Young's modulus of high burn-up UO{sub 2} fuel

    Energy Technology Data Exchange (ETDEWEB)

    Cappia, F. [European Commission, Joint Research Centre, Institute for Transuranium Elements, P.O. Box 2340, 76125, Karlsruhe (Germany); Technische Universität München, Faculty of Mechanical Engineering, Department of Nuclear Engineering, D-85748, Garching bei München (Germany); Pizzocri, D. [European Commission, Joint Research Centre, Institute for Transuranium Elements, P.O. Box 2340, 76125, Karlsruhe (Germany); Politecnico di Milano, Department of Energy, Nuclear Engineering Division, 20156, Milano (Italy); Marchetti, M. [European Commission, Joint Research Centre, Institute for Transuranium Elements, P.O. Box 2340, 76125, Karlsruhe (Germany); Université Montpellier 2, Institut d’Electronique du Sud UMR CNRS 5214, 34095, Montpellier (France); Schubert, A.; Van Uffelen, P. [European Commission, Joint Research Centre, Institute for Transuranium Elements, P.O. Box 2340, 76125, Karlsruhe (Germany); Luzzi, L. [Politecnico di Milano, Department of Energy, Nuclear Engineering Division, 20156, Milano (Italy); Papaioannou, D. [European Commission, Joint Research Centre, Institute for Transuranium Elements, P.O. Box 2340, 76125, Karlsruhe (Germany); Macián-Juan, R. [Technische Universität München, Faculty of Mechanical Engineering, Department of Nuclear Engineering, D-85748, Garching bei München (Germany); Rondinella, V.V., E-mail: Vincenzo.RONDINELLA@ec.europa.eu [European Commission, Joint Research Centre, Institute for Transuranium Elements, P.O. Box 2340, 76125, Karlsruhe (Germany)

    2016-10-15

    Vickers microhardness (HV{sub 0.1}) and Young's modulus (E) measurements of LWR UO{sub 2} fuel at burn-up ≥60 GWd/tHM are presented. Their ratio HV{sub 0.1}/E was found constant in the range 60–110 GWd/tHM. From the ratio and the microhardness values vs porosity, the Young's modulus dependence on porosity was derived and extended to the full radial profile, including the high burn-up structure (HBS). The dependence is well represented by a linear correlation. The data were compared to fuel performance codes correlations. A burn-up dependent factor was introduced in the Young's modulus expression. The modifications extend the experimental validation range of the TRANSURANUS correlation from un-irradiated to irradiated UO{sub 2} and up to 20% porosity. First simulations of LWR fuel rod irradiations were performed in order to illustrate the impact on fuel performance. In the specific cases selected, the simulations suggest a limited effect of the Young's modulus decrease due to burn-up on integral fuel performance. - Highlights: • Vickers microhardness and Young's modulus data of high burnup fuels are presented. • The data are compared to fuel performance codes' correlations. • A burn-up dependent factor is introduced for the Young's modulus of irradiated fuel. • The modification extends ranges of experimental validation of the code correlation. • The new burn-up dependent factor has limited effect on integral fuel performance.

  8. A criticality analysis of the GBC-32 dry storage cask with Hanbit nuclear power plant unit 3 fuel assemblies from the viewpoint of burnup credit

    Energy Technology Data Exchange (ETDEWEB)

    Yun, Hyung Ju; Kim, Do Yeon; Park, Kwang Heon; Hong, Ser Gi [Dept. of Nuclear Engineering, Kyung Hee University, Seoul (Korea, Republic of)

    2016-06-15

    Nuclear criticality safety analyses (NCSAs) considering burnup credit were performed for the GBC-32 cask. The used nuclear fuel assemblies (UNFAs) discharged from Hanbit Nuclear Power Plant Unit 3 Cycle 6 were loaded into the cask. Their axial burnup distributions and average discharge burnups were evaluated using the DeCART and Multi-purpose Analyzer for Static and Transient Effects of Reactors (MASTER) codes, and NCSAs were performed using SCALE 6.1/STandardized Analysis of Reactivity for Burnup Credit using SCALE (STARBUCS) and Monte Carlo N-Particle transport code, version 6 (MCNP 6). The axial burnup distributions were determined for 20 UNFAs with various initial enrichments and burnups, which were applied to the criticality analysis for the cask system. The UNFAs for 20- and 30-year cooling times were assumed to be stored in the cask. The criticality analyses indicated that keff values for UNFAs with nonuniform axial burnup distributions were larger than those with a uniform distribution, that is, the end effects were positive but much smaller than those with the reference distribution. The axial burnup distributions for 20 UNFAs had shapes that were more symmetrical with a less steep gradient in the upper region than the reference ones of the United States Department of Energy. These differences in the axial burnup distributions resulted in a significant reduction in end effects compared with the reference.

  9. Compound effects of operating parameters on burnup credit criticality analysis in boiling water reactor spent fuel assemblies

    Directory of Open Access Journals (Sweden)

    Shang-Chien Wu

    2018-02-01

    Full Text Available This study proposes a new method of analyzing the burnup credit in boiling water reactor spent fuel assemblies against various operating parameters. The operating parameters under investigation include fuel temperature, axial burnup profile, axial moderator density profile, and control blade usage. In particular, the effects of variations in one and two operating parameters on the curve of effective multiplication factor (keff versus burnup (B are, respectively, the so-called single and compound effects. All the calculations were performed using SCALE 6.1 together with the Evaluated Nuclear Data Files, part B (ENDF/B-VII238-neutron energy group data library. Furthermore, two geometrical models were established based on the General Electric (GE14 10 × 10 boiling water reactor fuel assembly and the Generic Burnup-Credit (GBC-68 storage cask. The results revealed that the curves of keff versus B, due to single and compound effects, can be approximated using a first degree polynomial of B. However, the reactivity deviation (or changes of keff,Δk in some compound effects was not a summation of the all Δk resulting from the two associated single effects. This phenomenon is undesirable because it may to some extent affect the precise assessment of burnup credit. In this study, a general formula was thus proposed to express the curves of keff versus B for both single and compound effects.

  10. SENSITIVITY AND UNCERTAINTY ANALYSIS OF COMMERCIAL REACTOR CRITICALS FOR BURNUP CREDIT

    Energy Technology Data Exchange (ETDEWEB)

    Radulescu, Georgeta [ORNL; Mueller, Don [ORNL; Wagner, John C [ORNL

    2009-01-01

    The purpose of this study is to provide insights into the neutronic similarities that may exist between a generic cask containing typical spent nuclear fuel assemblies and commercial reactor critical (CRC) state-points. Forty CRC state-points from five pressurized-water reactors were selected for the study and the type of CRC state-points that may be applicable for validation of burnup credit criticality safety calculations for spent fuel transport/storage/disposal systems are identified. The study employed cross-section sensitivity and uncertainty analysis methods developed at Oak Ridge National Laboratory and the TSUNAMI set of tools in the SCALE code system as a means to investigate system similarity on an integral and nuclide-reaction specific level. The results indicate that, except for the fresh fuel core configuration, all analyzed CRC state-points are either highly similar, similar, or marginally similar to a generic cask containing spent nuclear fuel assemblies with burnups ranging from 10 to 60 GWd/MTU. Based on the integral system parameter, C{sub k}, approximately 30 of the 40 CRC state-points are applicable to validation of burnup credit in the generic cask containing typical spent fuel assemblies with burnups ranging from 10 to 60 GWd/MTU. The state-points providing the highest similarity (C{sub k} > 0.95) were attained at or near the end of a reactor cycle. The C{sub k} values are dominated by neutron reactions with major actinides and hydrogen, as the sensitivities of these reactions are much higher than those of the minor actinides and fission products. On a nuclide-reaction specific level, the CRC state-points provide significant similarity for most of the actinides and fission products relevant to burnup credit. A comparison of energy-dependent sensitivity profiles shows a slight shift of the CRC K{sub eff} sensitivity profiles toward higher energies in the thermal region as compared to the K{sub eff} sensitivity profile of the generic cask

  11. A VVER-1000 LEU and MOX assembly computational benchmark analysis using the lattice burnup code EXCEL

    Energy Technology Data Exchange (ETDEWEB)

    Thilagam, L. [AERB-Safety Research Institute, Kalpakkam, Tamilnadu 603 102 (India)], E-mail: thilagam@igcar.gov.in; Sunil Sunny, C. [AERB-Safety Research Institute, Kalpakkam, Tamilnadu 603 102 (India); Jagannathan, V. [Light Water Reactor Physics Section, Reactor Physics Design Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India)], E-mail: v_jagan1952@rediffmail.com; Subbaiah, K.V. [AERB-Safety Research Institute, Kalpakkam, Tamilnadu 603 102 (India)

    2009-05-01

    Utilization of Mixed Uranium-Plutonium Oxide (MOX) fuel in VVER-1000 reactors envisages the core physics analysis using computational methods and validation of the related computer codes. Towards this objective, an international experts group has been established at OECD/NEA. The experts group facilitates sharing of existing information on physics parameters and fuel behaviour. Several benchmark exercises have been proposed by them with intent to investigate the core physics behaviour of a VVER-1000 reactor loaded with 2/3rd of low enriched uranium (LEU) fuel assemblies (FA) and 1/3rd of weapons grade mixed oxide (MOX) FA. In the present study an attempt is made to analyse 'AVVER-1000LEUandMOXAssemblyComputationalBenchmark' and predict the neutronics behaviour at the lattice level. The lattice burnup code EXCEL, developed at Light Water Reactor Physics Section, BARC is employed for this task. The EXCEL code uses the 172 energy group 'JEFF31GX' cross-section library in WIMS-D format. Assembly level fuel depletion calculations are performed up to a burnup of 40 MWD/kg of heavy metal (HM). Studies are made for the parametric variations of fuel and moderator temperatures, coolant density and boron content in the coolant. Both operational and off-normal states are analysed to determine the corresponding infinite neutron multiplication factor (k{sub {infinity}}). Pin wise isotopic compositions are computed as a function of burnup. Isotopic compositions in different annular regions of Uranium-Gadolinium (UGD) pin, fission rate distributions in UGD, UO{sub 2} and MOX pin cells are also computed. The predicted results are compared with the benchmark mean results.

  12. Criticality Analysis of Assembly Misload in a PWR Burnup Credit Cask

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, J. C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2008-01-31

    The Interim Staff Guidance on bumup credit (ISG-8) for spent fuel in storage and transportation casks, issued by the Nuclear Regulatory Commission's Spent Fuel Project Office, recommends a bumup measurement for each assembly to confirm the reactor record and compliance with the assembly bumup value used for loading acceptance. This recommendation is intended to prevent unauthorized loading (misloading) of assemblies due to inaccuracies in reactor burnup records and/or improper assembly identification, thereby ensuring that the appropriate subcritical margin is maintained. This report presents a computational criticality safety analysis of the consequences of misloading fuel assemblies in a highcapacity cask that relies on burnup credit for criticality safety. The purpose of this report is to provide a quantitative understanding of the effects of fuel misloading events on safety margins. A wide variety of fuel-misloading configurations are investigated and results are provided for informational purposes. This report does not address the likelihood of occurrence for any of the misload configurations considered. For representative, qualified bumup-enrichment combinations, with and without fission products included, misloading two assemblies that are underburned by 75% results in an increase in keff of 0.025-0.045, while misloading four assemblies that are underburned by 50% also results in an increase in keff of 0.025-0.045. For the cask and conditions considered, a reduction in bumup of 20% in all assemblies results in an increase in kff of less than 0.035. Misloading a single fresh assembly with 3, 4, or 5 wt% 235U enrichment results in an increase in keffof--0.02, 0.04, or 0.06, respectively. The report concludes with a summary of these and other important findings, as well as a discussion of relevant issues that should be considered when assessing the appropriate role of burnup measurements.

  13. Validation of depletion codes for burnup credit evaluation of LWR assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Ranta-aho, A. [Technical Research Centre of Finland VTT, POB 1000, 02044-VTT (Finland)

    2006-07-01

    This paper reports the comparison of the CASMO-4E predictions with the radiochemical assay data from assemblies irradiated in Takahama-3 PWR and Fukushima-Daini-2 BWR, and the most recently reported spent fuel data from the VVER-440 assembly irradiated in Novovoronezh 4. Some of the calculations were repeated with the ABURN burnup code, which is a combination of the MCNP4C Monte Carlo code and the ORIGEN2 depletion code. The cross section libraries applied were based on the ENDF/B-VI and the JEF-2.2 data. (authors)

  14. Thermal diffusivity of homogeneous SBR MOX fuel with a burn-up of 35 MWd/kgHM

    Science.gov (United States)

    Cozzo, C.; Staicu, D.; Pagliosa, G.; Papaioannou, D.; Rondinella, V. V.; Konings, R. J. M.; Walker, C. T.; Barker, M. A.; Hervé, P.

    2010-05-01

    The effect of burn-up on the thermal conductivity of homogeneous SBR MOX fuel is investigated and compared with standard UO 2 LWR fuel. New thermal diffusivity results obtained on SBR MOX fuel with a pellet burn-up of 35 MWd/kgHM are reported. The thermal diffusivity measurements were carried out at three radial positions using a shielded "laser-flash" device and show that the thermal diffusivity increases from the pellet periphery to the centre. The fuel thermal conductivity was found to be in the same range as for UO 2 of similar burn-up. The annealing behaviour was characterized in order to identify the degradation due to the out-of-pile auto-irradiation.

  15. Thermal diffusivity of homogeneous SBR MOX fuel with a burn-up of 35 MWd/kgHM

    Energy Technology Data Exchange (ETDEWEB)

    Cozzo, C. [European Commission, Joint Research Centre, Institute for Transuranium Element, P.O. Box 2340, D-76125 Karlsruhe (Germany); Staicu, D., E-mail: dragos.staicu@ec.europa.e [European Commission, Joint Research Centre, Institute for Transuranium Element, P.O. Box 2340, D-76125 Karlsruhe (Germany); Pagliosa, G.; Papaioannou, D.; Rondinella, V.V.; Konings, R.J.M.; Walker, C.T. [European Commission, Joint Research Centre, Institute for Transuranium Element, P.O. Box 2340, D-76125 Karlsruhe (Germany); Barker, M.A. [The UK' s National Nuclear Laboratory Ltd., Central Laboratory, Sellafield, Seascale, Cumbria CA20 1PG (United Kingdom); Herve, P. [LEEE, University Paris X, 1 Chemin Desvalliere, 92410 Ville d' Avray (France)

    2010-05-31

    The effect of burn-up on the thermal conductivity of homogeneous SBR MOX fuel is investigated and compared with standard UO{sub 2} LWR fuel. New thermal diffusivity results obtained on SBR MOX fuel with a pellet burn-up of 35 MWd/kgHM are reported. The thermal diffusivity measurements were carried out at three radial positions using a shielded 'laser-flash' device and show that the thermal diffusivity increases from the pellet periphery to the centre. The fuel thermal conductivity was found to be in the same range as for UO{sub 2} of similar burn-up. The annealing behaviour was characterized in order to identify the degradation due to the out-of-pile auto-irradiation.

  16. Uncertainty Propagation Analysis for PWR Burnup Pin-Cell Benchmark by Monte Carlo Code McCARD

    Directory of Open Access Journals (Sweden)

    Ho Jin Park

    2012-01-01

    Full Text Available In the Monte Carlo (MC burnup analyses, the uncertainty of a tally estimate at a burnup step may be induced from four sources: the statistical uncertainty caused by a finite number of simulations, the nuclear covariance data, uncertainties of number densities, and cross-correlations between the nuclear data and the number densities. In this paper, the uncertainties of kinf, reaction rates, and number densities for a PWR pin-cell benchmark problem are quantified by an uncertainty propagation formulation in the MC burnup calculations. The required sensitivities of tallied parameters to the microscopic cross-sections and the number densities are estimated by the MC differential operator sampling method accompanied by the fission source perturbation. The uncertainty propagation analyses are conducted with two nuclear covariance data—ENDF/B-VII.1 and SCALE6.1/COVA libraries—and the numerical results are compared with each other.

  17. Used Fuel Disposition Campaign - Baseline Studies for Ring Compression Testing of High-Burnup Fuel Cladding

    Energy Technology Data Exchange (ETDEWEB)

    Billone, M. C. [Argonne National Lab. (ANL), Argonne, IL (United States); Burtseva, T. A. [Argonne National Lab. (ANL), Argonne, IL (United States); Liu, Y. Y. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2012-11-23

    Structural analyses of high-burnup fuel require cladding mechanical properties and failure limits to assess fuel behavior during long-term dry cask storage and transportation. Pre-storage drying-transfer operations and early stage storage subject cladding to higher temperatures and much higher pressure-induced tensile hoop stresses relative to in-reactor operation and pool storage. Under these conditions, radial hydrides may precipitate during slow cooling and provide an additional embrittlement mechanism as the cladding temperature decreases below the ductile-to-brittle transition temperature (DBTT). On the basis of previous test results, susceptibility to radial-hydride precipitation depends on cladding material, microstructure, and pre-drying distribution of hydrides across the cladding wall, as well as peak hoop stresses and temperatures during drying operations and storage. Susceptibility to embrittlement depends on the extent of radial-hydride precipitation and the thickness of the outer-surface hydride rim. These results highlight the importance of determining the DBTT for high-burnup cladding as a function of peak drying-storage temperatures and stresses and including the relevant mechanical properties in cask structural analyses. Additional testing is needed at lower (and perhaps more realistic) peak drying-storage temperatures and stresses, for which the DBTT is expected to decrease.

  18. A multi-platform linking code for fuel burnup and radiotoxicity analysis

    Science.gov (United States)

    Cunha, R.; Pereira, C.; Veloso, M. A. F.; Cardoso, F.; Costa, A. L.

    2014-02-01

    A linking code between ORIGEN2.1 and MCNP has been developed at the Departamento de Engenharia Nuclear/UFMG to calculate coupled neutronic/isotopic results for nuclear systems and to produce a large number of criticality, burnup and radiotoxicity results. In its previous version, it evaluated the isotopic composition evolution in a Heat Pipe Power System model as well as the radiotoxicity and radioactivity during lifetime cycles. In the new version, the code presents features such as multi-platform execution and automatic results analysis. Improvements made in the code allow it to perform simulations in a simpler and faster way without compromising accuracy. Initially, the code generates a new input for MCNP based on the decisions of the user. After that, MCNP is run and data, such as recoverable energy per prompt fission neutron, reaction rates and keff, are automatically extracted from the output and used to calculate neutron flux and cross sections. These data are then used to construct new ORIGEN inputs, one for each cell in the core. Each new input is run on ORIGEN and generates outputs that represent the complete isotopic composition of the core on that time step. The results show good agreement between GB (Coupled Neutronic/Isotopic code) and Monteburns (Automated, Multi-Step Monte Carlo Burnup Code System), developed by the Los Alamos National Laboratory.

  19. Fuel burnup analysis for IRIS reactor using MCNPX and WIMS-D5 codes

    Science.gov (United States)

    Amin, E. A.; Bashter, I. I.; Hassan, Nabil M.; Mustafa, S. S.

    2017-02-01

    International Reactor Innovative and Secure (IRIS) reactor is a compact power reactor designed with especial features. It contains Integral Fuel Burnable Absorber (IFBA). The core is heterogeneous both axially and radially. This work provides the full core burn up analysis for IRIS reactor using MCNPX and WIMDS-D5 codes. Criticality calculations, radial and axial power distributions and nuclear peaking factor at the different stages of burnup were studied. Effective multiplication factor values for the core were estimated by coupling MCNPX code with WIMS-D5 code and compared with SAS2H/KENO-V code values at different stages of burnup. The two calculation codes show good agreement and correlation. The values of radial and axial powers for the full core were also compared with published results given by SAS2H/KENO-V code (at the beginning and end of reactor operation). The behavior of both radial and axial power distribution is quiet similar to the other data published by SAS2H/KENO-V code. The peaking factor values estimated in the present work are close to its values calculated by SAS2H/KENO-V code.

  20. Assessment of Fission Product Cross-Section Data for Burnup Credit Applications

    Energy Technology Data Exchange (ETDEWEB)

    Leal, Luiz C [ORNL; Derrien, Herve [ORNL; Dunn, Michael E [ORNL; Mueller, Don [ORNL

    2007-12-01

    Past efforts by the Department of Energy (DOE), the Electric Power Research Institute (EPRI), the Nuclear Regulatory Commission (NRC), and others have provided sufficient technical information to enable the NRC to issue regulatory guidance for implementation of pressurized-water reactor (PWR) burnup credit; however, consideration of only the reactivity change due to the major actinides is recommended in the guidance. Moreover, DOE, NRC, and EPRI have noted the need for additional scientific and technical data to justify expanding PWR burnup credit to include fission product (FP) nuclides and enable burnup credit implementation for boiling-water reactor (BWR) spent nuclear fuel (SNF). The criticality safety assessment needed for burnup credit applications will utilize computational analyses of packages containing SNF with FP nuclides. Over the years, significant efforts have been devoted to the nuclear data evaluation of major isotopes pertinent to reactor applications (i.e., uranium, plutonium, etc.); however, efforts to evaluate FP cross-section data in the resonance region have been less thorough relative to actinide data. In particular, resonance region cross-section measurements with corresponding R-matrix resonance analyses have not been performed for FP nuclides. Therefore, the objective of this work is to assess the status and performance of existing FP cross-section and cross-section uncertainty data in the resonance region for use in burnup credit analyses. Recommendations for new cross-section measurements and/or evaluations are made based on the data assessment. The assessment focuses on seven primary FP isotopes (103Rh, 133Cs, 143Nd, 149Sm, 151Sm, 152Sm, and 155Gd) that impact reactivity analyses of transportation packages and two FP isotopes (153Eu and 155Eu) that impact prediction of 155Gd concentrations. Much of the assessment work was completed in 2005, and the assessment focused on the latest FP cross-section evaluations available in the

  1. Modeling of pore coarsening in the rim region of high burn-up UO{sub 2} fuel

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Hongxing; Long, Chong Sheng [Science and Technology on Reactor Fuel and Materials Laboratory, Nuclear Power Institute of China, Chengdu (China)

    2016-08-15

    An understanding of the coarsening process of the large fission gas pores in the high burn-up structure (HBS) of irradiated UO{sub 2} fuel is very necessary for analyzing the safety and reliability of fuel rods in a reactor. A numerical model for the description of pore coarsening in the HBS based on the Ostwald ripening mechanism, which has successfully explained the coarsening process of precipitates in solids is developed. In this model, the fission gas atoms are treated as the special precipitates in the irradiated UO{sub 2} fuel matrix. The calculated results indicate that the significant pore coarsening and mean pore density decrease in the HBS occur upon surpassing a local burn-up of 100 GWd/tM. The capability of this model is successfully validated against irradiation experiments of UO{sub 2} fuel, in which the average pore radius, pore density, and porosity are directly measured as functions of local burn-up. Comparisons with experimental data show that, when the local burn-up exceeds 100 GWd/tM, the calculated results agree well with the measured data.

  2. Critical assessment of the pore size distribution in the rim region of high burnup UO{sub 2} fuels

    Energy Technology Data Exchange (ETDEWEB)

    Cappia, F. [European Commission, Joint Research Centre, Institute for Transuranium Elements, P.O. Box 2340, 76125 Karlsruhe (Germany); Department of Nuclear Engineering, Faculty of Mechanical Engineering, Technische Universität München, D-85748 Garching bei München (Germany); Pizzocri, D. [European Commission, Joint Research Centre, Institute for Transuranium Elements, P.O. Box 2340, 76125 Karlsruhe (Germany); Nuclear Engineering Division, Energy Department, Politecnico di Milano, 20156 Milano (Italy); Schubert, A.; Van Uffelen, P.; Paperini, G.; Pellottiero, D. [European Commission, Joint Research Centre, Institute for Transuranium Elements, P.O. Box 2340, 76125 Karlsruhe (Germany); Macián-Juan, R. [Department of Nuclear Engineering, Faculty of Mechanical Engineering, Technische Universität München, D-85748 Garching bei München (Germany); Rondinella, V.V., E-mail: Vincenzo.RONDINELLA@ec.europa.eu [European Commission, Joint Research Centre, Institute for Transuranium Elements, P.O. Box 2340, 76125 Karlsruhe (Germany)

    2016-11-15

    A new methodology is introduced to analyse porosity data in the high burnup structure. Image analysis is coupled with the adaptive kernel density estimator to obtain a detailed characterisation of the pore size distribution, without a-priori assumption on the functional form of the distribution. Subsequently, stereological analysis is carried out. The method shows advantages compared to the classical approach based on the histogram in terms of detail in the description and accuracy within the experimental limits. Results are compared to the approximation of a log-normal distribution. In the investigated local burnup range (80–200 GWd/tHM), the agreement of the two approaches is satisfactory. From the obtained total pore density and mean pore diameter as a function of local burnup, pore coarsening is observed starting from ≈100 GWd/tHM, in agreement with a previous investigation. - Highlights: • A new methodology to analyse porosity is introduced. • The method shows advantages compared to the histogram. • Pore density and mean diameter data vs. burnup are presented. • Pore coarsening is observed starting from ≈100 GWd/tHM.

  3. 78 FR 67348 - Invitation for Public Comment on Draft Test Plan for the High Burnup Dry Storage Cask Research...

    Science.gov (United States)

    2013-11-12

    ... Invitation for Public Comment on Draft Test Plan for the High Burnup Dry Storage Cask Research and Development Project (CDP) AGENCY: Fuel Cycle Technologies, Office of Nuclear Energy, Department of Energy... multiple entities while comments are resolved. Dated: November 5, 2013. Jay Jones, Office of Fuel Cycle...

  4. Applicability of the MCNP-ACAB system to inventory prediction in high-burnup fuels: sensitivity/uncertainty estimates

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Herranz, N.; Cabellos, O. [Madrid Polytechnic Univ., Dept. of Nuclear Engineering (Spain); Cabellos, O.; Sanz, J. [Madrid Polytechnic Univ., 2 Instituto de Fusion Nuclear (Spain); Sanz, J. [Univ. Nacional Educacion a Distancia, Dept. of Power Engineering, Madrid (Spain)

    2005-07-01

    We present a new code system which combines the Monte Carlo neutron transport code MCNP-4C and the inventory code ACAB as a suitable tool for high burnup calculations. Our main goal is to show that the system, by means of ACAB capabilities, enables us to assess the impact of neutron cross section uncertainties on the inventory and other inventory-related responses in high burnup applications. The potential impact of nuclear data uncertainties on some response parameters may be large, but only very few codes exist which can treat this effect. In fact, some of the most reported effective code systems in dealing with high burnup problems, such as CASMO-4, MCODE and MONTEBURNS, lack this capability. As first step, the potential of our system, ruling out the uncertainty capability, has been compared with that of those code systems, using a well referenced high burnup pin-cell benchmark exercise. It is proved that the inclusion of ACAB in the system allows to obtain results at least as reliable as those obtained using other inventory codes, such as ORIGEN2. Later on, the uncertainty analysis methodology implemented in ACAB, including both the sensitivity-uncertainty method and the uncertainty analysis by the Monte Carlo technique, is applied to this benchmark problem. We estimate the errors due to activation cross section uncertainties in the prediction of the isotopic content up to the high-burnup spent fuel regime. The most relevant uncertainties are remarked, and some of the most contributing cross sections to those uncertainties are identified. For instance, the most critical reaction for Am{sup 242m} is Am{sup 241}(n,{gamma}-m). At 100 MWd/kg, the cross-section uncertainty of this reaction induces an error of 6.63% on the Am{sup 242m} concentration.The uncertainties in the inventory of fission products reach up to 30%.

  5. Hydrides reorientation investigation of high burn-up PWR fuel cladding

    Science.gov (United States)

    Valance, Stéphane; Bertsch, Johannes

    2015-09-01

    The direction of formation of hydride in fuel cladding tube is a major issue for the assessment of the cladding remaining ductility after service. This behavior is quite well known for fresh material, but few results exist for irradiated material. The reorientation behavior of a Zircaloy-4 fuel cladding (AREVA duplex DX-D4) at a burn-up of around 72 GWd t-1 is investigated here. The increase of the fraction of reoriented hydrides through repeated thermo-mechanical loading is inspected; as well, the possibility to recover a state with a minimized quantity of reoriented hydrides is tested using pure thermal loading cycles. The study is completed by a qualitative assessment of the hydrogen density in the duplex layer, where a dependence of the hydrides density on the hoop stress state is observed.

  6. Monte Carlo calculations of the REBUS critical experiment for validation of burn-up credit

    Energy Technology Data Exchange (ETDEWEB)

    Hennebach, M.; Kuhl, H. [WTI GmbH, Julich (Germany)

    2008-07-01

    The REBUS experiment is a valuable benchmark for the validation of Monte Carlo criticality codes within the context of burn-up credit. It investigates the difference in reactivity worth of unirradiated fuel rods and of fuel rods irradiated in a PWR. This paper presents results of criticality calculations for this experiment with the Monte Carlo codes MCNP and SCALE/KENO. The results show that even the comparatively small reactivity loss of about 2000 pcm measured in this experiment can be calculated within an accuracy of 6 per cent. A detailed comparison of measured and calculated core characteristics (fission rate and flux distributions) shows good agreement, which indicates an adequately detailed model geometry for criticality calculations. The slight underestimation (500 pcm) of absolute k(eff) values is not out of the typical range for criticality benchmark experiments.

  7. Impact of Reactor Operating Parameters on Cask Reactivity in BWR Burnup Credit

    Energy Technology Data Exchange (ETDEWEB)

    Ilas, Germina [ORNL; Betzler, Benjamin R [ORNL; Ade, Brian J [ORNL

    2017-01-01

    This paper discusses the effect of reactor operating parameters used in fuel depletion calculations on spent fuel cask reactivity, with relevance for boiling-water reactor (BWR) burnup credit (BUC) applications. Assessments that used generic BWR fuel assembly and spent fuel cask configurations are presented. The considered operating parameters, which were independently varied in the depletion simulations for the assembly, included fuel temperature, bypass water density, specific power, and operating history. Different operating history scenarios were considered for the assembly depletion to determine the effect of relative power distribution during the irradiation cycles, as well as the downtime between cycles. Depletion, decay, and criticality simulations were performed using computer codes and associated nuclear data within the SCALE code system. Results quantifying the dependence of cask reactivity on the assembly depletion parameters are presented herein.

  8. Fuel modeling at high burn-up: recent development of the GERMINAL code

    Science.gov (United States)

    Melis, J.-C.; Piron, J.-P.; Roche, L.

    1993-09-01

    In the frame of research and development on fast breeder reactors fuels, CEA/DEC is developing the computer code GERMINAL to study fuel pin thermal and mechanical behaviour during steady-state and accidental conditions. The development of the GERMINAL 1 code is foreseen in two steps: (1) The GERMINAL 1-1 version which is presently delivered fully documented with a physical qualification guaranteed up to 8 at%. (2) The GERMINAL 1-2 version which, in addition to what is presently treated in GERMINAL 1-1, includes the treatment of high burn-up effects on the the fission gas release and the fuel-clad interface (called JOG). The validation of GERMINAL 1-2 is presently in progress and will include specific experiments (JOG tests) performed in the CABRI reactor.

  9. Accident source terms for boiling water reactors with high burnup cores.

    Energy Technology Data Exchange (ETDEWEB)

    Gauntt, Randall O.; Powers, Dana Auburn; Leonard, Mark Thomas

    2007-11-01

    The primary objective of this report is to provide the technical basis for development of recommendations for updates to the NUREG-1465 Source Term for BWRs that will extend its applicability to accidents involving high burnup (HBU) cores. However, a secondary objective is to re-examine the fundamental characteristics of the prescription for fission product release to containment described by NUREG-1465. This secondary objective is motivated by an interest to understand the extent to which research into the release and behaviors of radionuclides under accident conditions has altered best-estimate calculations of the integral response of BWRs to severe core damage sequences and the resulting radiological source terms to containment. This report, therefore, documents specific results of fission product source term analyses that will form the basis for the HBU supplement to NUREG-1465. However, commentary is also provided on observed differences between the composite results of the source term calculations performed here and those reflected NUREG-1465 itself.

  10. Mechanical Fatigue Testing of High-Burnup Fuel for Transportation Applications

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jy-An John [ORNL; Wang, Hong [ORNL

    2015-05-01

    This report describes testing designed to determine the ability of high burnup (HBU) (>45 GWd/MTU) spent fuel to maintain its integrity under normal conditions of transportation. An innovative system, Cyclic Integrated Reversible-bending Fatigue Tester (CIRFT), has been developed at Oak Ridge National Laboratory (ORNL) to test and evaluate the mechanical behavior of spent nuclear fuel (SNF) under conditions relevant to storage and transportation. The CIRFT system is composed of a U-frame equipped with load cells for imposing the pure bending loads on the SNF rod test specimen and measuring the in-situ curvature of the fuel rod during bending using a set up with three linear variable differential transformers (LVDTs).

  11. Advanced Corrosion-Resistant Zr Alloys for High Burnup and Generation IV Application

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Y. H.; Park, S. Y.; Lee, M. H.; Choi, B. K.; Baek, J. H.; Park, J. Y.; Kim, J. H.; Kim, H. G.; Jung, Y. H.; Bang, B. G

    2006-08-15

    The systematic study was performed to develop the advanced corrosion-resistant Zr alloys for high burnup and Gen IV application. The corrosion behavior was significantly changed with the alloy composition and the corrosion environment. In general, the model alloys with a higher alloying elements showed a higher corrosion resistance. Among the model alloys tested in this study, Zr-10Cr-0.2Fe showed the best corrosion resistance regardless of the corrosion condition. The oxide on the higher corrosion-resistant alloy such as Zr-1.0Cr-0.2Fe consisted of mainly columnar grains, and it have a higher tetragonal phase stability. In comparison with other alloys being considered for the SCWR, the Zr alloys showed a lower corrosion rate than ferritic-martensitic steels. The results of this study imply that, at least from a corrosion standpoint, Zr alloys deserve consideration as potential cladding or structural materials in supercritical water cooled reactors.

  12. Development of burnup dependent fuel rod model in COBRA-TF

    Science.gov (United States)

    Yilmaz, Mine Ozdemir

    The purpose of this research was to develop a burnup dependent fuel thermal conductivity model within Pennsylvania State University, Reactor Dynamics and Fuel Management Group (RDFMG) version of the subchannel thermal-hydraulics code COBRA-TF (CTF). The model takes into account first, the degradation of fuel thermal conductivity with high burnup; and second, the fuel thermal conductivity dependence on the Gadolinium content for both UO2 and MOX fuel rods. The modified Nuclear Fuel Industries (NFI) model for UO2 fuel rods and Duriez/Modified NFI Model for MOX fuel rods were incorporated into CTF and fuel centerline predictions were compared against Halden experimental test data and FRAPCON-3.4 predictions to validate the burnup dependent fuel thermal conductivity model in CTF. Experimental test cases from Halden reactor fuel rods for UO2 fuel rods at Beginning of Life (BOL), through lifetime without Gd2O3 and through lifetime with Gd 2O3 and a MOX fuel rod were simulated with CTF. Since test fuel rod and FRAPCON-3.4 results were based on single rod measurements, CTF was run for a single fuel rod surrounded with a single channel configuration. Input decks for CTF were developed for one fuel rod located at the center of a subchannel (rod-centered subchannel approach). Fuel centerline temperatures predicted by CTF were compared against the measurements from Halden experimental test data and the predictions from FRAPCON-3.4. After implementing the new fuel thermal conductivity model in CTF and validating the model with experimental data, CTF model was applied to steady state and transient calculations. 4x4 PWR fuel bundle configuration from Purdue MOX benchmark was used to apply the new model for steady state and transient calculations. First, one of each high burnup UO2 and MOX fuel rods from 4x4 matrix were selected to carry out single fuel rod calculations and fuel centerline temperatures predicted by CTF/TORT-TD were compared against CTF /TORT-TD /FRAPTRAN

  13. Data Mining Techniques to Estimate Plutonium, Initial Enrichment, Burnup, and Cooling Time in Spent Fuel Assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Trellue, Holly Renee [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Fugate, Michael Lynn [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Tobin, Stephen Joesph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-03-19

    The Next Generation Safeguards Initiative (NGSI), Office of Nonproliferation and Arms Control (NPAC), National Nuclear Security Administration (NNSA) of the U.S. Department of Energy (DOE) has sponsored a multi-laboratory, university, international partner collaboration to (1) detect replaced or missing pins from spent fuel assemblies (SFA) to confirm item integrity and deter diversion, (2) determine plutonium mass and related plutonium and uranium fissile mass parameters in SFAs, and (3) verify initial enrichment (IE), burnup (BU), and cooling time (CT) of facility declaration for SFAs. A wide variety of nondestructive assay (NDA) techniques were researched to achieve these goals [Veal, 2010 and Humphrey, 2012]. In addition, the project includes two related activities with facility-specific benefits: (1) determination of heat content and (2) determination of reactivity (multiplication). In this research, a subset of 11 integrated NDA techniques was researched using data mining solutions at Los Alamos National Laboratory (LANL) for their ability to achieve the above goals.

  14. Triton burnup study using scintillating fiber detector on JT-60U

    Energy Technology Data Exchange (ETDEWEB)

    Harano, Hideki [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment

    1997-09-01

    The DT fusion reactor cannot be realized without knowing how the fusion-produced 3.5 MeV {alpha} particles behave. The {alpha} particles` behavior can be simulated using the 1 MeV triton. To investigate the 1 MeV triton`s behavior, a new type of directional 14 MeV neutron detector, scintillating fiber (Sci-Fi) detector has been developed and installed on JT-60U in the cooperation with LANL as part of a US-Japan collaboration. The most remarkable feature of the Sci-Fi detector is that the plastic scintillating fibers are employed for the neutron sensor head. The Sci-Fi detector measures and extracts the DT neutrons from the fusion radiation field in high time resolution (10 ms) and wide dynamic range (3 decades). Triton burnup analysis code TBURN has been made in order to analyze the time evolution of DT neutron emission rate obtained by the Sci-Fi detector. The TBURN calculations reproduced the measurements fairly well, and the validity of the calculation model that the slowing down of the 1 MeV triton was classical was confirmed. The Sci-Fi detector`s directionality indicated the tendency that the DT neutron emission profile became more and more peaked with the time progress. In this study, in order to examine the effect of the toroidal field ripple on the triton burnup, R{sub p}-scan and n{sub e}-scan experiments have been performed. The R{sub p}-scan experiment indicates that the triton`s transport was increased as the ripple amplitude over the triton became larger. In the n{sub e}-scan experiment, the DT neutron emission showed the characteristic changes after the gas puffing injection. It was theoretically confirmed that the gas puffing was effective for the collisionality scan. (J.P.N.) 127 refs.

  15. Neutron transport-burnup code MCORGS and its application in fusion fission hybrid blanket conceptual research

    Science.gov (United States)

    Shi, Xue-Ming; Peng, Xian-Jue

    2016-09-01

    Fusion science and technology has made progress in the last decades. However, commercialization of fusion reactors still faces challenges relating to higher fusion energy gain, irradiation-resistant material, and tritium self-sufficiency. Fusion Fission Hybrid Reactors (FFHR) can be introduced to accelerate the early application of fusion energy. Traditionally, FFHRs have been classified as either breeders or transmuters. Both need partition of plutonium from spent fuel, which will pose nuclear proliferation risks. A conceptual design of a Fusion Fission Hybrid Reactor for Energy (FFHR-E), which can make full use of natural uranium with lower nuclear proliferation risk, is presented. The fusion core parameters are similar to those of the International Thermonuclear Experimental Reactor. An alloy of natural uranium and zirconium is adopted in the fission blanket, which is cooled by light water. In order to model blanket burnup problems, a linkage code MCORGS, which couples MCNP4B and ORIGEN-S, is developed and validated through several typical benchmarks. The average blanket energy Multiplication and Tritium Breeding Ratio can be maintained at 10 and 1.15 respectively over tens of years of continuous irradiation. If simple reprocessing without separation of plutonium from uranium is adopted every few years, FFHR-E can achieve better neutronic performance. MCORGS has also been used to analyze the ultra-deep burnup model of Laser Inertial Confinement Fusion Fission Energy (LIFE) from LLNL, and a new blanket design that uses Pb instead of Be as the neutron multiplier is proposed. In addition, MCORGS has been used to simulate the fluid transmuter model of the In-Zinerater from Sandia. A brief comparison of LIFE, In-Zinerater, and FFHR-E will be given.

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

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Hao, E-mail: jiangh@ornl.gov; Wang, Jy-An John; Wang, Hong

    2016-12-01

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

  17. An Approach for Validating Actinide and Fission Product Burnup Credit Criticality Safety Analyses-Isotopic Composition Predictions

    Energy Technology Data Exchange (ETDEWEB)

    Radulescu, Georgeta [ORNL; Gauld, Ian C [ORNL; Ilas, Germina [ORNL; Wagner, John C [ORNL

    2011-01-01

    The expanded use of burnup credit in the United States (U.S.) for storage and transport casks, particularly in the acceptance of credit for fission products, has been constrained by the availability of experimental fission product data to support code validation. The U.S. Nuclear Regulatory Commission (NRC) staff has noted that the rationale for restricting the Interim Staff Guidance on burnup credit for storage and transportation casks (ISG-8) to actinide-only is based largely on the lack of clear, definitive experiments that can be used to estimate the bias and uncertainty for computational analyses associated with using burnup credit. To address the issues of burnup credit criticality validation, the NRC initiated a project with the Oak Ridge National Laboratory to (1) develop and establish a technically sound validation approach for commercial spent nuclear fuel (SNF) criticality safety evaluations based on best-available data and methods and (2) apply the approach for representative SNF storage and transport configurations/conditions to demonstrate its usage and applicability, as well as to provide reference bias results. The purpose of this paper is to describe the isotopic composition (depletion) validation approach and resulting observations and recommendations. Validation of the criticality calculations is addressed in a companion paper at this conference. For isotopic composition validation, the approach is to determine burnup-dependent bias and uncertainty in the effective neutron multiplication factor (keff) due to bias and uncertainty in isotopic predictions, via comparisons of isotopic composition predictions (calculated) and measured isotopic compositions from destructive radiochemical assay utilizing as much assay data as is available, and a best-estimate Monte Carlo based method. This paper (1) provides a detailed description of the burnup credit isotopic validation approach and its technical bases, (2) describes the application of the approach for

  18. THE INVESTIGATION OF BURNUP CHARACTERISTICS USING THE SERPENT MONTE CARLO CODE FOR A SODIUM COOLED FAST REACTOR

    Directory of Open Access Journals (Sweden)

    MEHMET E. KORKMAZ

    2014-06-01

    Full Text Available In this research, we investigated the burnup characteristics and the conversion of fertile 232Th into fissile 233U in the core of a Sodium-Cooled Fast Reactor (SFR. The SFR fuel assemblies were designed for burning 232Th fuel (fuel pin 1 and 233U fuel (fuel pin 2 and include mixed minor actinide compositions. Monte Carlo simulations were performed using Serpent Code1.1.19 to compare with CRAM (Chebyshev Rational Approximation Method and TTA (Transmutation Trajectory Analysis method in the burnup calculation mode. The total heating power generated in the system was assumed to be 2000 MWth. During the reactor operation period of 600 days, the effective multiplication factor (keff was between 0.964 and 0.954 and peaking factor is 1.88867.

  19. Analysis of the behavior under irradiation of high burnup nuclear fuels with the computer programs FRAPCON and FRAPTRAN

    Energy Technology Data Exchange (ETDEWEB)

    Reis, Regis; Silva, Antonio Teixeira e, E-mail: teixeira@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2017-11-01

    The objective of this paper is to verify the validity and accuracy of the results provided by computer programs FRAPCON-3.4a and FRAPTRAN-1.4, used in the simulation process of the irradiation behavior of Pressurized Water Reactors (PWR) fuel rods, in steady-state and transient operational conditions at high burnup. To achieve this goal, the results provided by these computer simulations are compared with experimental data available in the database FUMEX III. Through the results, it was found that the computer programs used have a good ability to predict the operational behavior of PWR fuel rods in high burnup steady-state conditions and under the influence of Reactivity Initiated Accident (RIA). (author)

  20. Coolant Density and Control Blade History Effects in Extended BWR Burnup Credit

    Energy Technology Data Exchange (ETDEWEB)

    Ade, Brian J [ORNL; Marshall, William BJ J [ORNL; Bowman, Stephen M [ORNL; Gauld, Ian C [ORNL; Ilas, Germina [ORNL; Martinez-Gonzalez, Jesus S [ORNL

    2015-01-01

    Oak Ridge National Laboratory and the US Nuclear Regulatory Commission have initiated a multiyear project to investigate the application of burnup credit (BUC) for boiling water reactor (BWR) fuel in storage and transportation casks. This project includes two phases. The first phase investigates the applicability of peak reactivity methods currently used for spent fuel pools to spent fuel storage and transportation casks and the validation of reactivity (keff) calculations and predicted spent fuel compositions. The second phase focuses on extending BUC beyond peak reactivity. This paper documents work performed to date investigating some aspects of extended BUC. (The technical basis for application of peak reactivity methods to BWR fuel in storage and transportation systems is presented in a companion paper.) Two reactor operating parameters are being evaluated to establish an adequate basis for extended BWR BUC: (1) the effect of axial void profile and (2) the effect of control blade utilization during operation. A detailed analysis of core simulator data for one cycle of a modern operating BWR plant was performed to determine the range of void profiles and the variability of the profile experienced during irradiation. Although a single cycle does not provide complete data, the data obtained are sufficient to determine the primary effects and to identify conservative modeling approaches. These data were used in a study of the effect of axial void profile. The first stage of the study was determination of the necessary moderator density temporal fidelity in depletion modeling. After the required temporal fidelity was established, multiple void profiles were used to examine the effect on cask reactivity. The results of these studies are being used to develop recommendations for conservatively modeling the void profile effects for BWR depletion calculations. The second operational parameter studied was control blade history. Control blades are inserted in

  1. Extended Burnup Credit for BWR Spent Nuclear Fuel in Storage and Transportation Systems

    Energy Technology Data Exchange (ETDEWEB)

    Ade, Brian J [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Bowman, Stephen M [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Gauld, Ian C [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Ilas, Germina [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Martinez, J. S. [Univ. Politecnica de Madrid (Spain). Dept. of Nuclear Engineering

    2015-01-01

    [Full Text] Oak Ridge National Laboratory and the United States Nuclear Regulatory Commission have initiated a multiyear project to investigate the application of burnup credit (BUC) for boiling-water reactor (BWR) fuel in storage and transportation casks. This project includes two phases. The first phase investigates the applicability of peak reactivity methods currently used for spent fuel pools to spent fuel storage and transportation casks and the validation of reactivity (keff) calculations and depleted fuel compositions. The second phase focuses on extending BUC beyond peak reactivity. This paper documents work performed to date, investigating some aspects of extended BUC, and it also describes the plan to complete the evaluations. The technical basis for application of peak reactivity methods to BWR fuel in storage and transportation systems is presented in a companion paper. Two reactor operating parameters are being evaluated to establish an adequate basis for extended BWR BUC, including investigation of the axial void profile effect and the effect of control blade utilization during operation. A detailed analysis of core simulator data for one cycle of an operating BWR plant was performed to determine the range of void profiles and the variability of the profile experienced during irradiation. While a single cycle does not provide complete data, the data obtained are sufficient to use to determine the primary effects and identify conservative modeling approaches. Using data resulting from a single cycle, the axial void profile is studied by first determining the temporal fidelity necessary in depletion modeling, and then using multiple void profiles to examine the effect of the void profile on cask reactivity. The results of these studies are being used to develop recommendations for conservatively modeling the void profile effects for BWR depletion calculations. The second operational parameter studied is control blade exposure. Control blades

  2. Quantification of the computational accuracy of code systems on the burn-up credit using experimental re-calculations; Quantifizierung der Rechengenauigkeit von Codesystemen zum Abbrandkredit durch Experimentnachrechnungen

    Energy Technology Data Exchange (ETDEWEB)

    Behler, Matthias; Hannstein, Volker; Kilger, Robert; Moser, Franz-Eberhard; Pfeiffer, Arndt; Stuke, Maik

    2014-06-15

    In order to account for the reactivity-reducing effect of burn-up in the criticality safety analysis for systems with irradiated nuclear fuel (''burnup credit''), numerical methods to determine the enrichment and burnup dependent nuclide inventory (''burnup code'') and its resulting multiplication factor k{sub eff} (''criticality code'') are applied. To allow for reliable conclusions, for both calculation systems the systematic deviations of the calculation results from the respective true values, the bias and its uncertainty, are being quantified by calculation and analysis of a sufficient number of suitable experiments. This quantification is specific for the application case under scope and is also called validation. GRS has developed a methodology to validate a calculation system for the application of burnup credit in the criticality safety analysis for irradiated fuel assemblies from pressurized water reactors. This methodology was demonstrated by applying the GRS home-built KENOREST burnup code and the criticality calculation sequence CSAS5 from SCALE code package. It comprises a bounding approach and alternatively a stochastic, which both have been exemplarily demonstrated by use of a generic spent fuel pool rack and a generic dry storage cask, respectively. Based on publicly available post irradiation examination and criticality experiments, currently the isotopes of uranium and plutonium elements can be regarded for.

  3. Simulation of Low-Enriched Uranium (LEU) Burnup in Russian VVER Reactors with the HELIOS Code Package

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, B.D.; Kravchenko, J.; Lazarenko, A.; Pavlovitchev, A.; Sidorenko, V.; Chetverikov, A.

    2000-03-01

    The HELIOS reactor-physics computer program system was used to simulate the burnup of UO{sub 2} fuel in three VVER reactors. The manner in which HELIOS was used in these simulations is described. Predictions of concentrations for actinides up to {sup 244}Cm and for isotopes of neodymium were compared with laboratory-measured values. Reasonable agreement between calculated and measured values was seen for experimental samples from a fuel rod in the interior of an assembly.

  4. In Comparative Analysis for Fuel Burnup of Fuel Assembly Designs for the 300 kW Small Medical Reactor

    Science.gov (United States)

    Sambuu, Odmaa; Nanzad, Norov

    2009-03-01

    A 300 kW small medical reactor was designed to be used for boron neutron capture therapy (BNCT) at KAIST in 1996 [1]. In this paper, analysis for the core life cycle of the original design of the BNCT facility and modifications of the fuel assembly configuration and enrichment to get a proper life cycle were performed and a criticality, neutron flux distribution and fuel burnup calculations were carried out.

  5. OECD/NEA burnup credit criticality benchmarks phase IIIA: Criticality calculations of BWR spent fuel assemblies in storage and transport

    Energy Technology Data Exchange (ETDEWEB)

    Okuno, Hiroshi; Naito, Yoshitaka [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Ando, Yoshihira [Toshiba Corp., Kawasaki, Kanagawa (Japan)

    2000-09-01

    The report describes the final results of Phase IIIA Benchmarks conducted by the Burnup Credit Criticality Calculation Working Group under the auspices of the Nuclear Energy Agency of the Organization for Economic Cooperation and Development (OECD/NEA). The benchmarks are intended to confirm the predictive capability of the current computer code and data library combinations for the neutron multiplication factor (k{sub eff}) of a layer of irradiated BWR fuel assembly array model. In total 22 benchmark problems are proposed for calculations of k{sub eff}. The effects of following parameters are investigated: cooling time, inclusion/exclusion of FP nuclides and axial burnup profile, and inclusion of axial profile of void fraction or constant void fractions during burnup. Axial profiles of fractional fission rates are further requested for five cases out of the 22 problems. Twenty-one sets of results are presented, contributed by 17 institutes from 9 countries. The relative dispersion of k{sub eff} values calculated by the participants from the mean value is almost within the band of {+-}1%{delta}k/k. The deviations from the averaged calculated fission rate profiles are found to be within {+-}5% for most cases. (author)

  6. Effects of microstructural constraints on the transport of fission products in uranium dioxide at low burnups

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Harn Chyi; Rudman, Karin; Krishnan, Kapil; McDonald, Robert [Arizona State University, Tempe, AZ (United States); Dickerson, Patricia [Los Alamos National Lab, Los Alamos, NM (United States); Gong, Bowen [Arizona State University, Tempe, AZ (United States); Peralta, Pedro, E-mail: pperalta@asu.edu [Arizona State University, Tempe, AZ (United States)

    2016-08-15

    Diffusion of fission gases in UO{sub 2} is studied at low burnups, before bubble growth and coalescence along grain boundaries (GBs) become dominant, using a 3-D finite element model that incorporates actual UO{sub 2} microstructures. Grain boundary diffusivities are assigned based on crystallography with lattice and GB diffusion coupled with temperature to account for temperature gradients. Heterogeneity of GB properties and connectivity can induce regions where concentration is locally higher than without GB diffusion. These regions are produced by “bottlenecks” in the GB network because of lack of connectivity among high diffusivity GBs due to crystallographic constraints, and they can lead to localized swelling. Effective diffusivities were calculated assuming a uniform distribution of high diffusivity among GBs. Results indicate an increase over the bulk diffusivity with a clear grain size effect and that connectivity and properties of different GBs become important factors on the variability of fission product concentration at the microscale. - Highlights: • Microstructure models are developed to study fission gas transport in oxide fuels. • Crystallographic and temperature dependent material properties are applied. • Fission product concentration is affected by grain boundary distribution. • High concentration regions can form as controlled by the grain boundary connectivity.

  7. Burnup simulations and spent fuel characteristics of ZrO 2 based inert matrix fuels

    Science.gov (United States)

    Schneider, E. A.; Deinert, M. R.; Herring, S. T.; Cady, K. B.

    2007-03-01

    Reducing the inventory of long lived isotopes that are contained in spent nuclear fuel is essential for maximizing repository capacity and extending the lifetime of related storage. Because of their non-fertile matrices, inert matrix fuels (IMF's) could be an ideal vehicle for using light-water reactors to help decrease the inventory of plutonium and other transuranics (neptunium, americium, curium) that are contained within spent uranium oxide fuel (UOX). Quantifying the characteristics of spent IMF is therefore of fundamental importance to determining its effect on repository design and capacity. We consider six ZrO 2 based IMF formulations with different transuranic loadings in a 1-8 IMF to UOX pin-cell arrangement. Burnup calculations are performed using a collision probability model where transport of neutrons through space is modeled using fuel to moderator transport and escape probabilities. The lethargy dependent neutron flux is treated with a high resolution multigroup thermalization method. The results of the reactor physics model are compared to a benchmark case performed with Montebruns and indicate that the approach yields reliable results applicable to high-level analyses of spent fuel isotopics. The data generated show that a fourfold reduction in the radiological and integrated thermal output is achievable in single recycle using IMF, as compared to direct disposal of an energy equivalent spent UOX.

  8. TEM Characterization of High Burn-up Microstructure of U-7Mo Alloy

    Energy Technology Data Exchange (ETDEWEB)

    Jian Gan; Brandon Miller; Dennis Keiser; Adam Robinson; James Madden; Pavel Medvedev; Daniel Wachs

    2014-04-01

    As an essential part of global nuclear non-proliferation effort, the RERTR program is developing low enriched U-Mo fuels (< 20% U-235) for use in research and test reactors that currently employ highly enriched uranium fuels. One type of fuel being developed is a dispersion fuel plate comprised of U-7Mo particles dispersed in Al alloy matrix. Recent TEM characterizations of the ATR irradiated U-7Mo dispersion fuel plates include the samples with a local fission densities of 4.5, 5.2, 5.6 and 6.3 E+21 fissions/cm3 and irradiation temperatures of 101-136?C. The development of the irradiated microstructure of the U-7Mo fuel particles consists of fission gas bubble superlattice, large gas bubbles, solid fission product precipitates and their association to the large gas bubbles, grain subdivision to tens or hundreds of nanometer size, collapse of bubble superlattice, and amorphisation. This presentation will describe the observed microstructures specifically focusing on the U-7Mo fuel particles. The impact of the observed microstructure on the fuel performance and the comparison of the relevant features with that of the high burn-up UO2 fuels will be discussed.

  9. Chemical burnup determination based on spectrophotometric measurement of total rare earth fission products, uranium, and plutonium

    Energy Technology Data Exchange (ETDEWEB)

    Marsh, S.F.; Ortiz, M.R.; Rein, J.E.

    1975-10-01

    A chemical burnup procedure incorporates the ion-exchange separation of uranium, plutonium, and total rare earth fission products (as the fission monitor) followed by the spectrophotometric determination of each. The separation involves retaining uranyl and plutonyl chloride complexes on a macroporous anion exchange column from 12 M HCl, whereas the rare earths and most fission products pass through. Subsequently, plutonium is eluted with 0.1 M HI-12 M HCl and uranium with 0.1 M HCl. From the initial effluent of the first column, the rare earth group is separated on a second column of either (1) macroporous anion exchange resin from HNO/sub 3/-CH/sub 3/OH, or (2) pellicular cation exchange particles from HCl-C/sub 2/H/sub 5/OH. The HNO/sub 3/--CH/sub 3/OH system normally is used to separate the rare earth group from fuel cladding elements and other fission products. The HCl--C/sub 2/H/sub 5/OH system additionally separates the rare earth group from americium. Arsenazo III is the chromogenic agent for the spectrophotometric determination of the separated uranium, plutonium, and rare earth fractions.

  10. Propagation of Nuclear Data Uncertainties for ELECTRA Burn-up Calculations

    Science.gov (United States)

    Sjöstrand, H.; Alhassan, E.; Duan, J.; Gustavsson, C.; Koning, A. J.; Pomp, S.; Rochman, D.; Österlund, M.

    2014-04-01

    The European Lead-Cooled Training Reactor (ELECTRA) has been proposed as a training reactor for fast systems within the Swedish nuclear program. It is a low-power fast reactor cooled by pure liquid lead. In this work, we propagate the uncertainties in 239Pu transport data to uncertainties in the fuel inventory of ELECTRA during the reactor lifetime using the Total Monte Carlo approach (TMC). Within the TENDL project, nuclear models input parameters were randomized within their uncertainties and 740 239Pu nuclear data libraries were generated. These libraries are used as inputs to reactor codes, in our case SERPENT, to perform uncertainty analysis of nuclear reactor inventory during burn-up. The uncertainty in the inventory determines uncertainties in: the long-term radio-toxicity, the decay heat, the evolution of reactivity parameters, gas pressure and volatile fission product content. In this work, a methodology called fast TMC is utilized, which reduces the overall calculation time. The uncertainty of some minor actinides were observed to be rather large and therefore their impact on multiple recycling should be investigated further. It was also found that, criticality benchmarks can be used to reduce inventory uncertainties due to nuclear data. Further studies are needed to include fission yield uncertainties, more isotopes, and a larger set of benchmarks.

  11. SEM Characterization of the High Burn-up Microstructure of U-7Mo Alloy

    Energy Technology Data Exchange (ETDEWEB)

    Dennis D. Keiser, Jr.; Jan-Fong Jue; Jian Gan; Brandon Miller; Adam Robinson; Pavel Medvedev; James Madden; Dan Wachs; M. Teague

    2014-04-01

    During irradiation, the microstructure of U-7Mo evolves until at a fission density near 5x1021 f/cm3 a high-burnup microstructure exists that is very different than what was observed at lower fission densities. This microstructure is dominated by randomly distributed, relatively large, homogeneous fission gas bubbles. The bubble superlattice has collapsed in many microstructural regions, and the fuel grain sizes, in many areas, become sub-micron in diameter with both amorphous fuel and crystalline fuel present. Solid fission product precipitates can be found inside the fission gas bubbles. To generate more information about the characteristics of the high-fission density microstructure, three samples irradiated in the RERTR-7 experiment have been characterized using a scanning electron microscope equipped with a focused ion beam. The FIB was used to generate samples for SEM imaging and to perform 3D reconstruction of the microstructure, which can be used to look for evidence of possible fission gas bubble interlinkage.

  12. Thermal property change of MOX and UO{sub 2} irradiated up to high burnup of 74 GWd/t

    Energy Technology Data Exchange (ETDEWEB)

    Nakae, Nobuo, E-mail: nakae-nobuo@jnes.go.jp [Japan Nuclear Energy Safety Organization (JNES), Toranomon Towers Office, 4-1-28, Toranomon, Minato-ku, Tokyo 105-0001 (Japan); Akiyama, Hidetoshi; Miura, Hiromichi; Baba, Toshikazu; Kamimura, Katsuichiro [Japan Nuclear Energy Safety Organization (JNES), Toranomon Towers Office, 4-1-28, Toranomon, Minato-ku, Tokyo 105-0001 (Japan); Kurematsu, Shigeru; Kosaka, Yuji [Nuclear Development Corporation (NDC), 622-12, Funaishikawa, Tokai-mura, Ibaraki 319-1111 (Japan); Yoshino, Aya; Kitagawa, Takaaki [Mitsubishi Nuclear Fuel Co., LTD. (MNF), 12-1, Yurakucho 1-Chome, Chiyoda-ku, Tokyo 100-0006 (Japan)

    2013-09-15

    Thermal property is important because it controls fuel behavior under irradiation. The thermal property change at high burnup of more than 70 GWd/t is examined. Two kinds of MOX fuel rods, which were fabricated by MIMAS and SBR methods, and one referenced UO{sub 2} fuel rod were used in the experiment. These rods were taken from the pre-irradiated rods (IFA 609/626, of which irradiation test were carried out by Japanese PWR group) and re-fabricated and re-irradiated in HBWR as IFA 702 by JNES. The specification of fuel corresponds to that of 17 × 17 PWR type fuel and the axially averaged linear heat rates (LHR) of MOX rods are 25 kW/m (BOL of IFA 702) and 20 kW/m (EOL of IFA 702). The axial peak burnups achieved are about 74 GWd/t for both of MOX and UO{sub 2}. Centerline temperature and plenum gas pressure were measured in situ during irradiation. The measured centerline temperature is plotted against LHR at the position where thermocouples are fixed. The slopes of MOX are corresponded to each other, but that of UO{sub 2} is higher than those of MOX. This implies that the thermal conductivity of MOX is higher than that of UO{sub 2} at high burnup under the condition that the pellet–cladding gap is closed during irradiation. Gap closure is confirmed by the metallography of the postirradiation examinations. It is understood that thermal conductivity of MOX is lower than that of UO{sub 2} before irradiation since phonon scattering with plutonium in MOX becomes remarkable. A phonon scattering with plutonium decreases in MOX when burnup proceeds. Thus, thermal conductivity of MOX becomes close to that of UO{sub 2}. A reverse phenomenon is observed at high burnup region. The phonon scattering with fission products such as Nd and Zr causes a degradation of thermal conductivity of burnt fuel. It might be speculated that this scattering effect causes the phenomenon and the mechanism is discussed here.

  13. A feasibility and optimization study to determine cooling time and burnup of advanced test reactor fuels using a nondestructive technique

    Energy Technology Data Exchange (ETDEWEB)

    Navarro, Jorge [Univ. of Utah, Salt Lake City, UT (United States)

    2013-12-01

    The goal of this study presented is to determine the best available non-destructive technique necessary to collect validation data as well as to determine burn-up and cooling time of the fuel elements onsite at the Advanced Test Reactor (ATR) canal. This study makes a recommendation of the viability of implementing a permanent fuel scanning system at the ATR canal and leads3 to the full design of a permanent fuel scan system. The study consisted at first in determining if it was possible and which equipment was necessary to collect useful spectra from ATR fuel elements at the canal adjacent to the reactor. Once it was establish that useful spectra can be obtained at the ATR canal the next step was to determine which detector and which configuration was better suited to predict burnup and cooling time of fuel elements non-destructively. Three different detectors of High Purity Germanium (HPGe), Lanthanum Bromide (LaBr3), and High Pressure Xenon (HPXe) in two system configurations of above and below the water pool were used during the study. The data collected and analyzed was used to create burnup and cooling time calibration prediction curves for ATR fuel. The next stage of the study was to determine which of the three detectors tested was better suited for the permanent system. From spectra taken and the calibration curves obtained, it was determined that although the HPGe detector yielded better results, a detector that could better withstand the harsh environment of the ATR canal was needed. The in-situ nature of the measurements required a rugged fuel scanning system, low in maintenance and easy to control system. Based on the ATR canal feasibility measurements and calibration results it was determined that the LaBr3 detector was the best alternative for canal in-situ measurements; however in order to enhance the quality of the spectra collected using this scintillator a deconvolution method was developed. Following the development of the deconvolution method

  14. FY14 Status Report: CIRFT Testing Results on High Burnup UNF

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-09-01

    The objective of this project is to perform a systematic study of SNF/UNF (spent nuclear fuel/or used nuclear fuel) integrity under simulated transportation environments by using hot cell testing technology developed recently at Oak Ridge National Laboratory (ORNL), CIRFT (Cyclic Integrated Reversible-Bending Fatigue Tester). Under Nuclear Regulatory Commission (NRC) sponsorship, ORNL completed four benchmarking tests, four static tests, and twelve dynamic or cycle tests on H. B. Robinson (HBR) high burn-up (HBU) fuel. With support from the US Department of Energy and the NRC, CIRFT testing has been continued. The CIRFT testing was conducted on three HBR rods (R3, R4, and R5), with two specimens failed and one specimen un-failed. The total number of cycles in the test of un-failed specimens went over 2.23 107; the test was stopped as because the specimen did not show any sign of failure. The data analysis on all the HBR SNF rods demonstrated that it is necessary to characterize the fatigue life of used fuel rods in terms of both the curvature amplitude and the maximum of absolute of curvature extremes. The latter is significant because the maxima of extremes signify the maximum of tensile stress of the outer fiber of the bending rod. So far, a large variety of hydrogen contents has been covered in the CIRFT testing on HBR rods. It has been shown that the load amplitude is the dominant factor that controls the lifetime of bending rods, but the hydrogen content also has an important effect on the lifetime attained, according to the load range tested.

  15. Flexible modified candle burnup scheme based long life Pb-Bi cooled fast reactor with natural uranium as fuel cycle input employing coupled core

    Energy Technology Data Exchange (ETDEWEB)

    Su' ud, Zaki; SNM, Rida [Physics Dept., ITB, Jl. Ganesha 10, Bandung, West Java 40132 (Indonesia); Sekimoto, Hiroshi [Tokyo Inst. of Technology (Japan)

    2009-06-15

    Nuclear fuel enrichment and nuclear fuel reprocessing are two very sensitive issues related to the nuclear nonproliferation in the world especially when it is carried out in the developing countries. However without these two processes (at least one of them) the optimal nuclear energy utilization is difficult to be achieved. In this study, conceptual design of long life Pb-Bi cooled fast reactors which can be continuously operated by only supplying natural uranium without fuel enrichment plant or fuel reprocessing plant is performed. Therefore using this type of nuclear power plants optimum nuclear energy utilization including in developing countries can be easily conducted without the problem of nuclear proliferation. In this study conceptual design study of Pb-Bi cooled fast reactors which fuel cycle need only natural uranium input has been performed. In this case CANDLE1-2 burn-up strategy is slightly modified by introducing discreet regions. In this design the reactor cores are subdivided into several parts with the same volume in the axial directions. The natural uranium is initially put in region 1, after one cycle of 10 years of burn-up it is shifted to region 2 and the region 1 is filled by fresh natural uranium fuel. This concept is basically applied to all regions, i.e. shifted the core of I'th region into I+1 region after the end of 10 years burn-up cycle. To increase the criticality we adopt tandem of dual modified CANDLE cores and coupled them together. The calculation is performed using SRAC code system (SRAC-CITATION system). At the beginning we assume the power density level in each region and then we perform the burn-up calculation using the assumed data. The burn-up calculation is performed using cell burn-up in SRAC code which then give eight energy group macroscopic cross section data to be used in two dimensional R-Z geometry multi groups diffusion calculation. The average power density in each region resulted from the diffusion

  16. Monte Carlo burnup code acceleration with the correlated sampling method. Preliminary test on an UOX cell with TRIPOLI-4{sup R}

    Energy Technology Data Exchange (ETDEWEB)

    Dieudonne, C.; Dumonteil, E.; Malvagi, F.; Diop, C. M. [Commissariat a l' Energie Atomique et aux Energies Alternatives CEA, Service d' Etude des Reacteurs et de Mathematiques Appliquees, DEN/DANS/DM2S/SERMA/LTSD, F91191 Gif-sur-Yvette cedex (France)

    2013-07-01

    For several years, Monte Carlo burnup/depletion codes have appeared, which couple a Monte Carlo code to simulate the neutron transport to a deterministic method that computes the medium depletion due to the neutron flux. Solving Boltzmann and Bateman equations in such a way allows to track fine 3 dimensional effects and to get rid of multi-group hypotheses done by deterministic solvers. The counterpart is the prohibitive calculation time due to the time-expensive Monte Carlo solver called at each time step. Therefore, great improvements in term of calculation time could be expected if one could get rid of Monte Carlo transport sequences. For example, it may seem interesting to run an initial Monte Carlo simulation only once, for the first time/burnup step, and then to use the concentration perturbation capability of the Monte Carlo code to replace the other time/burnup steps (the different burnup steps are seen like perturbations of the concentrations of the initial burnup step). This paper presents some advantages and limitations of this technique and preliminary results in terms of speed up and figure of merit. Finally, we will detail different possible calculation scheme based on that method. (authors)

  17. Reactivity loss validation of high burn-up PWR fuels with pile-oscillation experiments in MINERVE

    Energy Technology Data Exchange (ETDEWEB)

    Leconte, P.; Vaglio-Gaudard, C.; Eschbach, R.; Di-Salvo, J.; Antony, M.; Pepino, A. [CEA, DEN, DER, Cadarache, F-13108 Saint-Paul-Lez-Durance (France)

    2012-07-01

    The ALIX experimental program relies on the experimental validation of the spent fuel inventory, by chemical analysis of samples irradiated in a PWR between 5 and 7 cycles, and also on the experimental validation of the spent fuel reactivity loss with bum-up, obtained by pile-oscillation measurements in the MINERVE reactor. These latter experiments provide an overall validation of both the fuel inventory and of the nuclear data responsible for the reactivity loss. This program offers also unique experimental data for fuels with a burn-up reaching 85 GWd/t, as spent fuels in French PWRs never exceeds 70 GWd/t up to now. The analysis of these experiments is done in two steps with the APOLLO2/SHEM-MOC/CEA2005v4 package. In the first one, the fuel inventory of each sample is obtained by assembly calculations. The calculation route consists in the self-shielding of cross sections on the 281 energy group SHEM mesh, followed by the flux calculation by the Method Of Characteristics in a 2D-exact heterogeneous geometry of the assembly, and finally a depletion calculation by an iterative resolution of the Bateman equations. In the second step, the fuel inventory is used in the analysis of pile-oscillation experiments in which the reactivity of the ALIX spent fuel samples is compared to the reactivity of fresh fuel samples. The comparison between Experiment and Calculation shows satisfactory results with the JEFF3.1.1 library which predicts the reactivity loss within 2% for burn-up of {approx}75 GWd/t and within 4% for burn-up of {approx}85 GWd/t. (authors)

  18. Development of Monteburns: A Code That Links MCNP and ORIGEN2 in an Automated Fashion for Burnup Calculations

    Energy Technology Data Exchange (ETDEWEB)

    Holly R. Trellue

    1998-12-01

    Monteburns is a fully automated tool that links the Monte Carlo transport code MCNP with the radioactive decay and burnup code 0RIGEN2. Monteburns produces many criticality and burnup computational parameters based on material feed/removal specifications, power(s), and time intervals. This code processes input from the user indicating the system geometry, initial material compositions, feed/removal, and other code-specific parameters. Results from MCNP, 0RIGEN2, and other calculations are then output successively as the code runs. The principle function of monteburns is to first transfer one-group cross sections and fluxes from MCNP to 0RIGEN2, and then transfer the resulting material compositions (after irradiation and/or decay) from 0RIGEN2 back to MCNP in a repeated, cyclic fashion. The main requirement of the code is that the user have a working MCNP input file and other input parameters; all interaction with 0RIGEN2 and other calculations are performed by monteburns. This report presents the results obtained from the benchmarking of monteburns to measured and previously obtained data from traditional Light Water Reactor systems. The majority of the differences seen between the two were less than five percent. These were primarily a result of variances in cross sections between MCNP, cross section libraries used by other codes, and observed values. With this understanding, this code can now be used with confidence for burnup calculations in three-dimensional systems. It was designed for use in the Accelerator Transmutation of Waste project at Los Alamos National Laboratory but is also being applied to the analysis of isotopic production/destruction of transuranic actinides in a reactor system. The code has now been shown to sufficiently support these calculations.

  19. Effect of fuel burnup and cross sections on modular HTGR (High-Temperature Gas-cooled Reactor) reactivity coefficients

    Science.gov (United States)

    Lefler, W.; Baxter, A.; Mathews, D.

    1987-12-01

    The temperature dependence of the reactivity coefficient in a prismatic block Modular High-Temperature Gas-Cooled Reactor (MHTGR) design is examined and found to be large and negative. Temperature coefficient results obtained with the ENDF/B-V data library were almost the same as results obtained with the earlier versions of the ENDF/B data library usually used at GA Technologies Inc., in spite of a significant eigenvalue increase with the ENDF/B-V data. The effects of fuel burnup and arbitrarily assumed cross section variations were examined and tabulated.

  20. Accident source terms for pressurized water reactors with high-burnup cores calculated using MELCOR 1.8.5.

    Energy Technology Data Exchange (ETDEWEB)

    Gauntt, Randall O.; Powers, Dana Auburn; Ashbaugh, Scott G.; Leonard, Mark Thomas; Longmire, Pamela

    2010-04-01

    In this study, risk-significant pressurized-water reactor severe accident sequences are examined using MELCOR 1.8.5 to explore the range of fission product releases to the reactor containment building. Advances in the understanding of fission product release and transport behavior and severe accident progression are used to render best estimate analyses of selected accident sequences. Particular emphasis is placed on estimating the effects of high fuel burnup in contrast with low burnup on fission product releases to the containment. Supporting this emphasis, recent data available on fission product release from high-burnup (HBU) fuel from the French VERCOR project are used in this study. The results of these analyses are treated as samples from a population of accident sequences in order to employ approximate order statistics characterization of the results. These trends and tendencies are then compared to the NUREG-1465 alternative source term prescription used today for regulatory applications. In general, greater differences are observed between the state-of-the-art calculations for either HBU or low-burnup (LBU) fuel and the NUREG-1465 containment release fractions than exist between HBU and LBU release fractions. Current analyses suggest that retention of fission products within the vessel and the reactor coolant system (RCS) are greater than contemplated in the NUREG-1465 prescription, and that, overall, release fractions to the containment are therefore lower across the board in the present analyses than suggested in NUREG-1465. The decreased volatility of Cs2MoO4 compared to CsI or CsOH increases the predicted RCS retention of cesium, and as a result, cesium and iodine do not follow identical behaviors with respect to distribution among vessel, RCS, and containment. With respect to the regulatory alternative source term, greater differences are observed between the NUREG-1465 prescription and both HBU and LBU predictions than exist between HBU and LBU

  1. Study of the triton-burnup process in different JET scenarios using neutron monitor based on CVD diamond

    Energy Technology Data Exchange (ETDEWEB)

    Nemtsev, G., E-mail: g.nemtsev@iterrf.ru; Amosov, V.; Meshchaninov, S.; Rodionov, R. [Institution “Project center ITER,” Moscow (Russian Federation); Popovichev, S. [CCFE, Culham Science Centre, Abingdon OX14 3DB (United Kingdom); Collaboration: EUROfusion Consortium, JET, Culham Science Centre, Abingdon OX14 3DB (United Kingdom)

    2016-11-15

    We present the results of analysis of triton burn-up process using the data from diamond detector. Neutron monitor based on CVD diamond was installed in JET torus hall close to the plasma center. We measure the part of 14 MeV neutrons in scenarios where plasma current varies in a range of 1-3 MA. In this experiment diamond neutron monitor was also able to detect strong gamma bursts produced by runaway electrons arising during the disruptions. We can conclude that CVD diamond detector will contribute to the study of fast particles confinement and help predict the disruption events in future tokamaks.

  2. Bias estimates used in lieu of validation of fission products and minor actinides in MCNP Keff calculations for PWR burnup credit casks

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, Don [ORNL; Marshall, William BJ J [ORNL; Wagner, John C [ORNL; Bowen, Douglas G [ORNL

    2015-09-01

    The U.S. Nuclear Regulatory Commission (NRC) Division of Spent Fuel Storage and Transportation recently issued Interim Staff Guidance (ISG) 8, Revision 3. This ISG provides guidance for burnup credit (BUC) analyses supporting transport and storage of PWR pressurized water reactor (PWR) fuel in casks. Revision 3 includes guidance for addressing validation of criticality (keff) calculations crediting the presence of a limited set of fission products and minor actinides (FP&MA). Based on previous work documented in NUREG/CR-7109, recommendation 4 of ISG-8, Rev. 3, includes a recommendation to use 1.5 or 3% of the FP&MA worth to conservatively cover the bias due to the specified FP&MAs. This bias is supplementary to the bias and bias uncertainty resulting from validation of keff calculations for the major actinides in SNF and does not address extension to actinides and fission products beyond those identified herein. The work described in this report involves comparison of FP&MA worths calculated using SCALE and MCNP with ENDF/B-V, -VI, and -VII based nuclear data and supports use of the 1.5% FP&MA worth bias when either SCALE or MCNP codes are used for criticality calculations, provided the other conditions of the recommendation 4 are met. The method used in this report may also be applied to demonstrate the applicability of the 1.5% FP&MA worth bias to other codes using ENDF/B V, VI or VII based nuclear data. The method involves use of the applicant s computational method to generate FP&MA worths for a reference SNF cask model using specified spent fuel compositions. The applicant s FP&MA worths are then compared to reference values provided in this report. The applicants FP&MA worths should not exceed the reference results by more than 1.5% of the reference FP&MA worths.

  3. Instant release of fission products in leaching experiments with high burn-up nuclear fuels in the framework of the Euratom project FIRST- Nuclides

    Science.gov (United States)

    Lemmens, K.; González-Robles, E.; Kienzler, B.; Curti, E.; Serrano-Purroy, D.; Sureda, R.; Martínez-Torrents, A.; Roth, O.; Slonszki, E.; Mennecart, T.; Günther-Leopold, I.; Hózer, Z.

    2017-02-01

    The instant release of fission products from high burn-up UO2 fuels and one MOX fuel was investigated by means of leach tests. The samples covered PWR and BWR fuels at average rod burn-up in the range of 45-63 GWd/tHM and included clad fuel segments, fuel segments with opened cladding, fuel fragments and fuel powder. The tests were performed with sodium chloride - bicarbonate solutions under oxidizing conditions and, for one test, in reducing Ar/H2 atmosphere. The iodine and cesium release could be partially explained by the differences in sample preparation, leading to different sizes and properties of the exposed surface areas. Iodine and cesium releases tend to correlate with FGR and linear power rating, but the scatter of the data is significant. Although the gap between the fuel and the cladding was closed in some high burn-up samples, fissures still provide possible preferential transport pathways.

  4. High-Burnup-Structure (HBS): Model Development in MARMOT for HBS Formation and Stability Under Radiation and High Temperature

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, K. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Bai, X. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Zhang, Y. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Biner, B. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-09-01

    A detailed phase field model for the formation of High Burnup Structure (HBS) was developed and implemented in MARMOT. The model treats the HBS formation as an irradiation-induced recrystallization. The model takes into consideration the stored energy associated with dislocations formed under irradiation. The accumulation of radiation damage, hence, increases the system free energy and triggers recrystallization. The increase in the free energy due to the formation of new grain boundaries is offset by the reduction in the free energy by creating dislocation-free grains at the expense of the deformed grains. The model was first used to study the growth of recrystallized flat and circular grains. The model reults were shown to agree well with theorrtical predictions. The case of HBS formation in UO2 was then investigated. It was found that a threshold dislocation density of (or equivalently a threshold burn-up of 33-40 GWd/t) is required for HBS formation at 1200K, which is in good agrrement with theory and experiments. In future studies, the presence of gas bubbles and their effect on the formation and evolution of HBS will be considered.

  5. Decay heat power of spent nuclear fuel of power reactors with high burnup at long-term storage

    Science.gov (United States)

    Ternovykh, Mikhail; Tikhomirov, Georgy; Saldikov, Ivan; Gerasimov, Alexander

    2017-09-01

    Decay heat power of actinides and fission products from spent nuclear fuel of power VVER-1000 type reactors at long-term storage is calculated. Two modes of storage are considered: mode in which single portion of actinides or fission products is loaded in storage facility, and mode in which actinides or fission products from spent fuel of one VVER reactor are added every year in storage facility during 30 years and then accumulated nuclides are stored without addition new nuclides. Two values of fuel burnup 40 and 70 MW·d/kg are considered for the mode of storage of single fuel unloading. For the mode of accumulation of spent fuel with subsequent storage, one value of burnup of 70 MW·d/kg is considered. Very long time of storage 105 years accepted in calculations allows to simulate final geological disposal of radioactive wastes. Heat power of fission products decreases quickly after 50-100 years of storage. The power of actinides decreases very slow. In passing from 40 to 70 MW·d/kg, power of actinides increases due to accumulation of higher fraction of 244Cm. These data are important in the back end of fuel cycle when improved cooling system of the storage facility will be required along with stronger radiation protection during storage, transportation and processing.

  6. Accident source terms for light-water nuclear power plants using high-burnup or MOX fuel.

    Energy Technology Data Exchange (ETDEWEB)

    Salay, Michael (U.S. Nuclear Regulatory Commission, Washington, D.C.); Gauntt, Randall O.; Lee, Richard Y. (U.S. Nuclear Regulatory Commission, Washington, D.C.); Powers, Dana Auburn; Leonard, Mark Thomas

    2011-01-01

    Representative accident source terms patterned after the NUREG-1465 Source Term have been developed for high burnup fuel in BWRs and PWRs and for MOX fuel in a PWR with an ice-condenser containment. These source terms have been derived using nonparametric order statistics to develop distributions for the timing of radionuclide release during four accident phases and for release fractions of nine chemical classes of radionuclides as calculated with the MELCOR 1.8.5 accident analysis computer code. The accident phases are those defined in the NUREG-1465 Source Term - gap release, in-vessel release, ex-vessel release, and late in-vessel release. Important differences among the accident source terms derived here and the NUREG-1465 Source Term are not attributable to either fuel burnup or use of MOX fuel. Rather, differences among the source terms are due predominantly to improved understanding of the physics of core meltdown accidents. Heat losses from the degrading reactor core prolong the process of in-vessel release of radionuclides. Improved understanding of the chemistries of tellurium and cesium under reactor accidents changes the predicted behavior characteristics of these radioactive elements relative to what was assumed in the derivation of the NUREG-1465 Source Term. An additional radionuclide chemical class has been defined to account for release of cesium as cesium molybdate which enhances molybdenum release relative to other metallic fission products.

  7. Decay heat power of spent nuclear fuel of power reactors with high burnup at long-term storage

    Directory of Open Access Journals (Sweden)

    Ternovykh Mikhail

    2017-01-01

    Full Text Available Decay heat power of actinides and fission products from spent nuclear fuel of power VVER-1000 type reactors at long-term storage is calculated. Two modes of storage are considered: mode in which single portion of actinides or fission products is loaded in storage facility, and mode in which actinides or fission products from spent fuel of one VVER reactor are added every year in storage facility during 30 years and then accumulated nuclides are stored without addition new nuclides. Two values of fuel burnup 40 and 70 MW·d/kg are considered for the mode of storage of single fuel unloading. For the mode of accumulation of spent fuel with subsequent storage, one value of burnup of 70 MW·d/kg is considered. Very long time of storage 105 years accepted in calculations allows to simulate final geological disposal of radioactive wastes. Heat power of fission products decreases quickly after 50-100 years of storage. The power of actinides decreases very slow. In passing from 40 to 70 MW·d/kg, power of actinides increases due to accumulation of higher fraction of 244Cm. These data are important in the back end of fuel cycle when improved cooling system of the storage facility will be required along with stronger radiation protection during storage, transportation and processing.

  8. Shutdown-induced tensile stress in monolithic miniplates as a possible cause of plate pillowing at very high burnup

    Energy Technology Data Exchange (ETDEWEB)

    Medvedev, Pavel G [Idaho National Laboratory; Ozaltun, Hakan [Idaho National Laboratory; Robinson, Adam Brady [Idaho National Laboratory; Rabin, Barry H [Idaho National Laboratory

    2014-04-01

    Post-irradiation examination of Reduced Enrichment for Research and Test Reactors (RERTR)-12 miniplates showed that in-reactor pillowing occurred in at least 4 plates, rendering performance of these plates unacceptable. To address in-reactor failures, efforts are underway to define the mechanisms responsible for in-reactor pillowing, and to suggest improvements to the fuel plate design and operational conditions. To achieve these objectives, the mechanical response of monolithic fuel to fission and thermally-induced stresses was modeled using a commercial finite element analysis code. Calculations of stresses and deformations in monolithic miniplates during irradiation and after the shutdown revealed that the tensile stress generated in the fuel increased from 2 MPa to 100 MPa at shutdown. The increase in tensile stress at shutdown possibly explains in-reactor pillowing of several RERTR-12 miniplates irradiated to the peak local burnup of up to 1.11x1022 fissions/cm3 . This paper presents the modeling approach and calculation results, and compares results with post-irradiation examinations and mechanical testing of irradiated fuel. The implications for the safe use of the monolithic fuel in research reactors are discussed, including the influence of fuel burnup and power on the magnitude of the shutdown-induced tensile stress.

  9. Benchmark calculation of SCALE-PC 4.3 CSAS6 module and burnup credit criticality analysis

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Hee Sung; Ro, Seong Gy; Shin, Young Joon; Kim, Ik Soo [Korea Atomic Energy Research Institute, Taejon (Korea)

    1998-12-01

    Calculation biases of SCALE-PC CSAS6 module for PWR spent fuel, metallized spent fuel and solution of nuclear materials have been determined on the basis of the benchmark to be 0.01100, 0.02650 and 0.00997, respectively. With the aid of the code system, nuclear criticality safety analysis for the spent fuel storage pool has been carried out to determine the minimum burnup of spent fuel required for safe storage. The criticality safety analysis is performed using three types of isotopic composition of spent fuel: ORIGEN2-calculated isotopic compositions; the conservative inventory obtained from the multiplication of ORIGEN2-calculated isotopic compositions by isotopic correction factors; the conservative inventory of only U, Pu and {sup 241}Am. The results show that the minimum burnup for three cases are 990,6190 and 7270 MWd/tU, respectively in the case of 5.0 wt% initial enriched spent fuel. (author). 74 refs., 68 figs., 35 tabs.

  10. Development of a method for xenon determination in the microstructure of high burn-up nuclear fuel[Dissertation 17527

    Energy Technology Data Exchange (ETDEWEB)

    Horvath, M. I

    2008-07-01

    In nuclear fuel, in approximately one quarter of the fissions, one of the two formed fission products is gaseous. These are mainly the noble gases xenon and krypton with isotopes of xenon contributing up to 90% of the product gases. These noble fission gases do not combine with other species, and have a low solubility in the normally used uranium oxide matrix. They can be dissolved in the fuel matrix or precipitate in nanometer-sized bubbles within the fuel grain, in micrometer-sized bubbles at the grain boundaries, and a fraction also precipitates in fuel pores, coming from fuel fabrication. A fraction of the gas can also be released into the plenum of the fuel rod. With increasing fission, and therefore burn-up, the ceramic fuel material experiences a transformation of its structure in the 'cooler' rim region of the fuel. A subdivision occurs of the original fuel grains of few microns size into thousands of small grains of sub-micron sizes. Additionally, larger pores are formed, which also leads into an increasing porosity in the fuel rim, called high burn-up structure. In this structure, only a small fraction of the fission gas remains in the matrix, the major quantity is said to accumulate in these pores. Because of this accumulation, the knowledge of the quantities of gas within these pores is of major interest in consideration to burn-up, fuel performance and especially for safety issues. In case of design based accidents, i.e. rapidly increasing temperature transients, the behavior of the fuel has to be estimated. Various analytical techniques have been used to determine the Xe concentration in nuclear fuel samples. The capabilities of EPMA (Electron Probe Micro-Analyser) and SIMS (Secondary Ion Mass Spectrometry) have been studied and provided some qualitative information, which has been used for determining Xe-matrix concentrations. First approaches combining these two techniques to estimate pore pressures have been recently reported. However

  11. Burn-up calculation of different thorium-based fuel matrixes in a thermal research reactor using MCNPX 2.6 code

    Directory of Open Access Journals (Sweden)

    Gholamzadeh Zohreh

    2014-12-01

    Full Text Available Decrease of the economically accessible uranium resources and the inherent proliferation resistance of thorium fuel motivate its application in nuclear power systems. Estimation of the nuclear reactor’s neutronic parameters during different operational situations is of key importance for the safe operation of nuclear reactors. In the present research, thorium oxide fuel burn-up calculations for a demonstrative model of a heavy water- -cooled reactor have been performed using MCNPX 2.6 code. Neutronic parameters for three different thorium fuel matrices loaded separately in the modelled thermal core have been investigated. 233U, 235U and 239Pu isotopes have been used as fissile element in the thorium oxide fuel, separately. Burn-up of three different fuels has been calculated at 1 MW constant power. 135X and 149Sm concentration variations have been studied in the modelled core during 165 days burn-up. Burn-up of thorium oxide enriched with 233U resulted in the least 149Sm and 135Xe productions and net fissile production of 233U after 165 days. The negative fuel, coolant and void reactivity of the used fuel assures safe operation of the modelled thermal core containing (233U-Th O2 matrix. Furthermore, utilisation of thorium breeder fuel demonstrates several advantages, such as good neutronic economy, 233U production and less production of long-lived α emitter high radiotoxic wastes in biological internal exposure point of view

  12. Estimate of fuel burnup spatial a multipurpose reactor in computer simulation; Estimativa da queima espacial do combustivel de um reator multiproposito por simulacao computacional

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Nadia Rodrigues dos, E-mail: nadia.santos@ifrj.edu.br [Instituto Federal de Educacao, Ciencia e Tecnologia do Rio de Janeiro (IFRJ), Paracambi, RJ (Brazil); Lima, Zelmo Rodrigues de; Moreira, Maria de Lourdes, E-mail: malu@ien.gov.br, E-mail: zrlima@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2015-07-01

    In previous research, which aimed, through computer simulation, estimate the spatial fuel burnup for the research reactor benchmark, material test research - International Atomic Energy Agency (MTR/IAEA), it was found that the use of the code in FORTRAN language, based on the diffusion theory of neutrons and WIMSD-5B, which makes cell calculation, bespoke be valid to estimate the spatial burnup other nuclear research reactors. That said, this paper aims to present the results of computer simulation to estimate the space fuel burnup of a typical multipurpose reactor, plate type and dispersion. the results were considered satisfactory, being in line with those presented in the literature. for future work is suggested simulations with other core configurations. are also suggested comparisons of WIMSD-5B results with programs often employed in burnup calculations and also test different methods of interpolation values obtained by FORTRAN. Another proposal is to estimate the burning fuel, taking into account the thermohydraulics parameters and the appearance of xenon. (author)

  13. Extended burnup core management for once-through uranium fuel cycles in LWRS. First annual report for the period 1 July 1979-30 June 1980

    Energy Technology Data Exchange (ETDEWEB)

    Sesonske, A.

    1980-08-01

    Detailed core management arrangements are developed requiring four operating cycles for the transition from present three-batch loading to an extended burnup four-batch plan for Zion-1. The ARMP code EPRI-NODE-P was used for core modeling. Although this work is preliminary, uranium and economic savings during the transition cycles appear of the order of 6 percent.

  14. Impacts of burnup-dependent swelling of metallic fuel on the performance of a compact breed-and-burn fast reactor

    Energy Technology Data Exchange (ETDEWEB)

    Hartanto, Donny; Heo, Woong; Kim, Chi Hyung; Kim, Yong Hee [Dept. of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon (Korea, Republic of)

    2016-04-15

    The U-Zr or U-TRU-Zr cylindrical metallic fuel slug used in fast reactors is known to swell significantly and to grow during irradiation. In neutronics simulations of metallic-fueled fast reactors, it is assumed that the slug has swollen and contacted cladding, and the bonding sodium has been removed from the fuel region. In this research, a realistic burnup-dependent fuel-swelling simulation was performed using Monte Carlo code McCARD for a single-batch compact sodium-cooled breed-and-burn reactor by considering the fuel-swelling behavior reported from the irradiation test results in EBR-II. The impacts of the realistic burnup-dependent fuel swelling are identified in terms of the reactor neutronics performance, such as core lifetime, conversion ratio, axial power distribution, and local burnup distributions. It was found that axial fuel growth significantly deteriorated the neutron economy of a breed-and-burn reactor and consequently impaired its neutronics performance. The bonding sodium also impaired neutron economy, because it stayed longer in the blanket region until the fuel slug reached 2% burnup.

  15. An Approach for Validating Actinide and Fission Product Burnup Credit Criticality Safety Analyses--Criticality (keff) Predictions

    Energy Technology Data Exchange (ETDEWEB)

    Scaglione, John M [ORNL; Mueller, Don [ORNL; Wagner, John C [ORNL

    2011-01-01

    One of the most significant remaining challenges associated with expanded implementation of burnup credit in the United States is the validation of depletion and criticality calculations used in the safety evaluation - in particular, the availability and use of applicable measured data to support validation, especially for fission products. Applicants and regulatory reviewers have been constrained by both a scarcity of data and a lack of clear technical basis or approach for use of the data. U.S. Nuclear Regulatory Commission (NRC) staff have noted that the rationale for restricting their Interim Staff Guidance on burnup credit (ISG-8) to actinide-only is based largely on the lack of clear, definitive experiments that can be used to estimate the bias and uncertainty for computational analyses associated with using burnup credit. To address the issue of validation, the NRC initiated a project with the Oak Ridge National Laboratory to (1) develop and establish a technically sound validation approach (both depletion and criticality) for commercial spent nuclear fuel (SNF) criticality safety evaluations based on best-available data and methods and (2) apply the approach for representative SNF storage and transport configurations/conditions to demonstrate its usage and applicability, as well as to provide reference bias results. The purpose of this paper is to describe the criticality (k{sub eff}) validation approach, and resulting observations and recommendations. Validation of the isotopic composition (depletion) calculations is addressed in a companion paper at this conference. For criticality validation, the approach is to utilize (1) available laboratory critical experiment (LCE) data from the International Handbook of Evaluated Criticality Safety Benchmark Experiments and the French Haut Taux de Combustion (HTC) program to support validation of the principal actinides and (2) calculated sensitivities, nuclear data uncertainties, and the limited available fission

  16. A Feasibility Study to Determine Cooling Time and Burnup of ATR Fuel Using a Nondestructive Technique and Three Types of Gamma-ray Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Jorge Navarro; Rahmat Aryaeinejad,; David W. Nigg

    2011-05-01

    A Feasibility Study to Determine Cooling Time and Burnup of ATR Fuel Using a Nondestructive Technique1 Rahmat Aryaeinejad, Jorge Navarro, and David W Nigg Idaho National Laboratory Abstract Effective and efficient Advanced Test Reactor (ATR) fuel management require state of the art core modeling tools. These new tools will need isotopic and burnup validation data before they are put into production. To create isotopic, burn up validation libraries and to determine the setup for permanent fuel scanner system a feasibility study was perform. The study consisted in measuring short and long cooling time fuel elements at the ATR canal. Three gamma spectroscopy detectors (HPGe, LaBr3, and HPXe) and two system configurations (above and under water) were used in the feasibility study. The first stage of the study was to investigate which detector and system configuration would be better suited for different scenarios. The second stage of the feasibility study was to create burnup and cooling time calibrations using experimental isotopic data collected and ORIGEN 2.2 burnup data. The results of the study establish that a better spectra resolution is achieve with an above the water configuration and that three detectors can be used in the permanent fuel scanner system for different situations. In addition it was conclude that a number of isotopic ratios and absolute measurements could be used to predict ATR fuel burnup and cooling times. 1This work was supported by the U.S. Depart¬ment of Energy (DOE) under Battelle Energy Alliance, LLC Contract No. DE-AC07-05ID14517.

  17. Analysis of Corrosion Residues Collected from the Aluminum Basket Rails of the High-Burnup Demonstration Cask.

    Energy Technology Data Exchange (ETDEWEB)

    Bryan, Charles R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-03-01

    On September, 2015, an inspection was performed on the TN-32B cask that will be used for the high-burnup demonstration project. During the survey, wooden cribbing that had been placed within the cask eleven years earlier to prevent shifting of the basket during transport was removed, revealing two areas of residue on the aluminum basket rails, where they had contacted the cribbing. The residue appeared to be a corrosion product, and concerns were raised that similar attack could exist at more difficult-to-inspect locations in the canister. Accordingly, when the canister was reopened, samples of the residue were collected for analysis. This report presents the results of that assessment, which determined that the corrosion was due to the presence of the cribbing. The corrosion was associated with fungal material, and fungal activity likely contributed to an aggressive chemical environment. Once the cask has been cleaned, there will be no risk of further corrosion.

  18. Estimating NIRR-1 burn-up and core life time expectancy using the codes WIMS and CITATION

    Science.gov (United States)

    Yahaya, B.; Ahmed, Y. A.; Balogun, G. I.; Agbo, S. A.

    The Nigeria Research Reactor-1 (NIRR-1) is a low power miniature neutron source reactor (MNSR) located at the Centre for Energy Research and Training, Ahmadu Bello University, Zaria Nigeria. The reactor went critical with initial core excess reactivity of 3.77 mk. The NIRR-1 cold excess reactivity measured at the time of commissioning was determined to be 4.97 mk, which is more than the licensed range of 3.5-4 mk. Hence some cadmium poison worth -1.2 mk was inserted into one of the inner irradiation sites which act as reactivity regulating device in order to reduce the core excess reactivity to 3.77 mk, which is within recommended licensed range of 3.5 mk and 4.0 mk. In this present study, the burn-up calculations of the NIRR-1 fuel and the estimation of the core life time expectancy after 10 years (the reactor core expected cycle) have been conducted using the codes WIMS and CITATION. The burn-up analyses carried out indicated that the excess reactivity of NIRR-1 follows a linear decreasing trend having 216 Effective Full Power Days (EFPD) operations. The reactivity worth of top beryllium shim data plates was calculated to be 19.072 mk. The result of depletion analysis for NIRR-1 core shows that (7.9947 ± 0.0008) g of U-235 was consumed for the period of 12 years of operating time. The production of the build-up of Pu-239 was found to be (0.0347 ± 0.0043) g. The core life time estimated in this research was found to be 30.33 years. This is in good agreement with the literature

  19. Journal of Agricultural Extension

    African Journals Online (AJOL)

    Mission Statement The mission of the "Journal of Agricultural Extension" is to publish conceptual papers and empirical research that tests, extends, or builds agricultural extension theory and contributes to the practice of extension worldwide. Scope of journal The Journal of Agricultural Extension" is devoted to the ...

  20. On the condition of UO2 nuclear fuel irradiated in a PWR to a burn-up in excess of 110 MWd/kgHM

    Science.gov (United States)

    Restani, R.; Horvath, M.; Goll, W.; Bertsch, J.; Gavillet, D.; Hermann, A.; Martin, M.; Walker, C. T.

    2016-12-01

    Post-irradiation examination results are presented for UO2 fuel from a PWR fuel rod that had been irradiated to an average burn-up of 105 MWd/kgHM and showed high fission gas release of 42%. The radial distribution of xenon and the partitioning of fission gas between bubbles and the fuel matrix was investigated using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) and electron probe microanalysis. It is concluded that release from the fuel at intermediate radial positions was mainly responsible for the high fission gas release. In this region thermal release had occurred from the high burn-up structure (HBS) at some point after the sixth irradiation cycle. The LA-ICP-MS results indicate that gas release had also occurred from the HBS in the vicinity of the pellet periphery. It is shown that the gas pressure in the HBS pores is well below the pressure that the fuel can sustain.

  1. PLUTON: Three-group neutronic code for burnup analysis of isotope generation and depletion in highly irradiated LWR fuel rods

    Energy Technology Data Exchange (ETDEWEB)

    Lemehov, Sergei E; Suzuki, Motoe [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2001-08-01

    PLUTON is a three-group neutronic code analyzing, as functions of time and burnup, the change of radial profiles, together with average values, of power density, burnup, concentration of trans-uranium elements, plutonium buildup, depletion of fissile elements, and fission product generation in water reactor fuel rod with standard UO{sub 2}, UO{sub 2}-Gd{sub 2}O{sub 3}, inhomogeneous MOX, and UO{sub 2}-ThO{sub 2}. The PLUTON code, which has been designed to be run on Windows PC, has adopted a theoretical shape function of neutron attenuation in pellet, which enables users to perform a very fast and accurate calculation easily. The present code includes the irradiation conditions of the Halden Reactor which gives verification data for the code. The total list of trans-uranium elements included in the calculations consists of {sub 92}U{sup 233-239}, {sub 93}Np{sup 237-239}, {sub 94}Pu{sup 238-243}, {sub 95}Am{sup 241-244} (including isomers), and {sub 96}Cm{sup 242-245}. Poisoning fission products are represented by {sub 54}Xe{sup 131,133,135}, {sub 48}Cd{sup 113}, {sub 62}Sm{sup 149,151,152}, {sub 64}Gd{sup 154-160}, {sub 63}Eu{sup 153,155}, {sub 36}Kr{sup 83,85}, {sub 42}Mo{sup 95}, {sub 43}Tc{sup 99}, {sub 45}Rh{sup 103}, {sub 47}Ag{sup 109}, {sub 53}I{sup 127,129,131}, {sub 55}Cs{sup 133}, {sub 57}La{sup 139}, {sub 59}Pr{sup 141}, {sub 60}Nd{sup 143-150}, {sub 61}Pm{sup 147}. Fission gases and volatiles included in the code are {sub 36}Kr{sup 83-86}, {sub 54}Xe{sup 129-136}, {sub 52}Te{sup 125-130}, {sub 53}I{sup 127-131}, {sub 55}Cs{sup 133-137}, and {sub 56}Ba{sup 135-140}. Verification has been performed up to 83 GWd/tU, and a satisfactory agreement has been obtained. (author)

  2. Determination of uranium concentration and burn-up of irradiated reactor fuel in contaminated areas in Belarus using uranium isotopic ratios in soil samples

    OpenAIRE

    Mironov, V. P.; Matusevich, J. L.; Kudrjashov, V. P.; Ananich, P. I.; Zhuravkov, V. V.; Boulyga, S. F.; Becker, J. S.

    2005-01-01

    An analytical method is described for the estimation of uranium concentrations, of U-235/U-238 and U-236/U-238 isotope ratios and burn-up of irradiated reactor uranium in contaminated soil samples by inductively coupled plasma mass spectrometry. Experimental results obtained at 12 sampling sites situated on northern and western radioactive fallout tails 4 to 53 km distant from Chernobyl nuclear power plant (NPP) are presented. Concentrations of irradiated uranium in the upper 0-10cm soil laye...

  3. Development of external coupling for calculation of the control rod worth in terms of burn-up for a WWER-1000 nuclear reactor

    Energy Technology Data Exchange (ETDEWEB)

    Noori-Kalkhoran, Omid, E-mail: o_noori@yahoo.com [Reactor Research School, Nuclear Science and Technology Research Institute (NSTRI), Tehran (Iran, Islamic Republic of); Yarizadeh-Beneh, Mehdi [Faculty of Engineering, Shahid Beheshti University, Tehran (Iran, Islamic Republic of); Ahangari, Rohollah [Reactor Research School, Nuclear Science and Technology Research Institute (NSTRI), Tehran (Iran, Islamic Republic of)

    2016-08-15

    Highlights: • Calculation of control rod worth in term of burn-up. • Calculation of differential and integral control rod worth. • Developing an external couple. • Modification of thermal-hydraulic profiles in calculations. - Abstract: One of the main problems relating to operation of a nuclear reactor is its safety and controlling system. The most widely used control systems for thermal reactors are neutron absorbent rods. In this study a code based method has been developed for calculation of integral and differential control rod worth in terms of burn-up for a WWER-1000 nuclear reactor. External coupling of WIMSD-5B, PARCS V2.7 and COBRA-EN has been used for this purpose. WIMSD-5B has been used for cell calculation and handling burn-up of the core in various days. PARCS V2.7 has been used for neutronic calculation of core and critical boron concentration search. Thermal-hydraulic calculation has been performed by COBRA-EN. An external coupling algorithm has been developed by MATLAB to couple and transfer suitable data between these codes in each step. Steady-State Power Picking Factors (PPFs) of the core and control rod worth for different control rod groups have been calculated from Beginning Of Cycle (BOC) to 289.7 Effective Full Power Days (EFPDs) in some steps. Results have been compared with the results of Bushehr Nuclear Power Plant (BNPP) Final Safety Analysis Report (FSAR). The results show a good agreement and confirm the ability of developed coupling in calculation of control rod worth in terms of burn-up.

  4. Rapid aqueous release of fission products from high burn-up LWR fuel: Experimental results and correlations with fission gas release

    Science.gov (United States)

    Johnson, L.; Günther-Leopold, I.; Kobler Waldis, J.; Linder, H. P.; Low, J.; Cui, D.; Ekeroth, E.; Spahiu, K.; Evins, L. Z.

    2012-01-01

    Studies of the rapid aqueous release of fission products from UO 2 and MOX fuel are of interest for the assessment of the safety of geological disposal of spent fuel, because of the associated potential contribution to dose in radiological safety assessment. Studies have shown that correlations between fission gas release (FGR) and the fraction rapidly leached of various long-lived fission products can provide a useful method to obtain some of this information. Previously, these studies have been limited largely to fuel with burn-up values below 50 MWd/kg U. Collaborative studies involving SKB, Studsvik, Nagra and PSI have provided new data on short-term release of 137Cs and 129I for a number of fuels irradiated to burn-ups of 50-75 MWd/kgU. In addition a method for analysis of leaching solutions for 79Se was developed. The results of the studies show that the fractional release of 137Cs is usually much lower than the FGR covering the entire range of burn-ups studied. Fractional 129I releases are somewhat larger, but only in cases in which the fuel was forcibly extracted from the cladding. Despite the expected high degree of segregation of fission gas (and by association 137Cs and 129I) in the high burn-up rim, no evidence was found for a significant contribution to release from the rim region. The method for 79Se analysis developed did not permit its detection. Nonetheless, based on the detection limit, the results suggest that 79Se is not preferentially leached from spent fuel.

  5. Isotopic analyses and calculation by use of JENDL-3.2 for high burn-up UO{sub 2} and MOX spent fuels

    Energy Technology Data Exchange (ETDEWEB)

    Sasahara, Akihiro; Matsumura, Tetsuo [Central Research Inst. of Electric Power Industry, Komae, Tokyo (Japan). Komae Research Lab.; Nicolaou, G.; Betti, M.; Walker, C.T.

    1997-03-01

    The post irradiation examinations (PIE) were carried out for high burn-up UO{sub 2} spent fuel (3.8%U235, average burn-up:60GWd/t) and mixed oxide (MOX) spent fuel (5.07%Pu, average burn-up:45GWd/t). The PIE includes, (a) isotopic analysis, (b) electron probe microanalysis (EPMA) in pellet cross section and so on. The results of isotopic analyses and EPMA were compared with ORIGEN2/82 and VIM-BURN calculation results. In VIM-BURN calculation, the nuclear data of actinides were proceeded from new data file, JENDL-3.2. The sensitivities of power history and moderator density to nuclides composition were investigated by VIM-BURN calculation and consequently power history mainly effected on Am241 and Am242m and moderator density effected on fissile nuclides. From EPMA results of U and Pu distribution in pellet, VIM-BURN calculation showed reasonable distribution in pellet cross section. (author)

  6. Burnup calculations using the OREST computer code for uranium dioxide fuel elements of boiling water reactors. Abbrandberechnung mit OREST fuer Urandioxid-Siedewasserreaktor-Brennelemente

    Energy Technology Data Exchange (ETDEWEB)

    Hesse, U.

    1991-01-01

    There are plans to also use plutonium containing fuel elements (mixed oxide fuel) in the BWR type reactors, with a proportion of up to one third of the entire fuel core. The new concept uses complete MOX fuel elements, as are used in the PWR type reactors. The OREST computer code has been designed for burnup calculations in PWRs. The situation in BWRs is different, as in these reactor types, fuel elements are heterogenous in design, and burnup calculations have to take into account the axial variations of the void fraction, so that multi-dimensional effects have to be calculated. The report explains that the one-dimensional OREST code can be enhanced by supplementing calculations, performed with the Monte-Carlo type KENO code in this case, and is thus suitable without restrictions for performing burnup calculations for MOX fuel elements in BWRs. The calculation method and performance is illustrated by the example of a UO{sub 2} fuel element of the Wuergassen reactor. The model calculations predict a relatively high residual activity in the upper part of the fuel element, and a distinct curium buildup in the lower third of the BWR fuel element. (orig./HP).

  7. Evaluation of the elastic constants of the high burnup nuclear fuel (U{sub 1-y},Gd{sub y})O{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Leite, Luciana T.; Dias, Marcio S., E-mail: ltl@cdtn.b, E-mail: marciod@cdtn.b [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2011-07-01

    Nuclear fuels with burnable poisons are applications in the scope of the nuclear energy for electricity generation. The discharge burnups of this type of fuel are higher than the discharge burnups of pure UO{sub 2} fuels with same enrichment of the fissile element. In conditions of high burnups and moderate transients, the fuel rods can be subject to the pellet/cladding mechanical interactions (PCMI). Elastic constants of the fuel and cladding are used in the thermo-mechanical evaluation of the PCMI. The fuel elastic constants are usually expressed as a function of temperature, composition and porosity. Data survey and modeling of elastic constants for the (U{sub 1-y},Gd{sub y})O{sub 2} fuel are developed in this paper. Due to small amount of the available measurements for the (U{sub 1-y},Gd{sub y})O{sub 2}, the modeling taken into account the data from UO{sub 2} and Gd{sub 2}O{sub 3} measurements. Available measurements of the Al{sub 2}O{sub 3} were also used in the model validation. The elastic constants of these materials have been fitted by an analytic equation, which depicts the whole range the dependences. (author)

  8. Development of a parallel processing couple for calculations of control rod worth in terms of burn-up in a WWER-1000 reactor

    Energy Technology Data Exchange (ETDEWEB)

    Noori-Kalkhoran, Omid; Ahangari, R. [Nuclear Science and Technology Research Institute (NSTRI), Tehran (Iran, Islamic Republic of). Reactor Research school; Shirani, A.S. [Shahid Beheshti Univ., Tehran (Iran, Islamic Republic of). Faculty of Engineering

    2017-03-15

    In this study a code based method has been developed for calculation of integral and differential control rod worth in terms of burn-up for a WWER-1000 reactor. Parallel processing of WIMSD-5B, PARCS V2.7 and COBRA-EN has been used for this purpose. WIMSD-5B has been used for cell calculation and handling burn-up of core at different days. PARCS V2.7?has been used for neutronic calculation of core and critical boron concentration search. Thermal-hydraulic calculation has been performed by COBRA-EN. A Parallel processing algorithm has been developed by MATLAB to couple and transfer suitable data between these codes in each step. Steady-State Power Picking Factors (PPFs) of the core and Control rod worth have been calculated from Beginning Of Cycle (BOC) to 289.7 Effective full Power Days (EFPDs) in some steps. Results have been compared with Bushehr Nuclear Power Plant (BNPP) Final Safety Analysis Report (FSAR) results. The results show great similarity and confirm the ability of developed coupling in calculation of control rod worth in terms of burn-up.

  9. Relationship between changes in the crystal lattice strain and thermal conductivity of high burnup UO{sub 2} pellets

    Energy Technology Data Exchange (ETDEWEB)

    Amaya, Masaki, E-mail: amaya.masaki@jaea.go.j [Fuel Safety Research Group, Nuclear Safety Research Center, Japan Atomic Energy Agency, Tokai-mura, Naka-gun, Ibaraki 319-1195 (Japan); Nakamura, Jinichi; Fuketa, Toyoshi [Fuel Safety Research Group, Nuclear Safety Research Center, Japan Atomic Energy Agency, Tokai-mura, Naka-gun, Ibaraki 319-1195 (Japan); Kosaka, Yuji [Nuclear Development Corporation, 622-12, Funaishikawa, Tokai-mura, Naka-gun, Ibaraki 319-1111 (Japan)

    2010-01-01

    Two kinds of disk-shaped UO{sub 2} samples (4 mm in diameter and 1 mm in thickness) were irradiated in a test reactor up to about 60 and 130 GWd/t, respectively. The microstructures of the samples were investigated by means of optical microscopy, scanning electron microscopy/ electron probe micro-analysis (SEM/EPMA) and micro-X-ray diffractometry. The measured lattice parameters tended to be considerably smaller than the reported values, and the typical cauliflower structure which is often observed in high burnup fuel pellet is hardly seen in these samples. Thermal diffusivities of the samples were also measured by using a laser flash method, and their thermal conductivities were evaluated by multiplying the heat capacity of unirradiated UO{sub 2} and sample densities. While the thermal conductivities of sample 2 showed recovery after being annealed at 1500 K, those of sample 4 were not clearly observed even after being annealed at 1500 K. These trends suggest that the amount of accumulated irradiation-induced defects depends on the irradiation condition of each sample. From the comparison of the changes in the lattice parameter and strain energy density before and after the thermal diffusivity measurements, it is likely that the thermal conductivity recovery in the temperature region from 1200 to 1500 K is related to the migration of dislocation.

  10. Analysis of burnup of Angra 2 PWR nuclear with addition of thorium dioxide fuel using ORIGEN-ARP

    Energy Technology Data Exchange (ETDEWEB)

    Goncalves, Isadora C.; Wichrowski, Caio C.; Oliveira, Claudio L. de; Vellozo, Sergio O.; Baptista, Camila O., E-mail: isadora.goncalves@ime.eb.br, E-mail: wichrowski@ime.eb.br, E-mail: d7luiz@yahoo.com.br, E-mail: vellozo@ime.eb.br, E-mail: camila.oliv.baptista@gmail.com [Instituto Militar de Engenharia (IME), Rio de Janeiro, RJ (Brazil). Secao de Engenharia Nuclear

    2017-11-01

    It is known that isotope {sup 232}thorium is a fertile nuclide with the ability to convert into {sup 233}uranium, a potentially fissile isotope, after absorbing a neutron. As there is a large stock of available thorium in the world, this element shows great promise in mitigate the world energy crisis, more particularly in the problem of uranium scarcity, besides being an alternative nuclear fuel for those currently used in reactors, and yet presenting advantages as an option for the non-proliferation movement, among others. In this study, the analysis of the remaining nuclides of burnup was carried out for the core configuration of a PWR (pressurized water reactor) reactor, specifically the Angra 2 reactor, using only uranium dioxide, its current configuration, and in different configurations including a mixed oxide of uranium and thorium in three concentrations, allowing a preliminary assessment of the feasibility of the modification of the fuel, the resulting production of {sup 233}uranium, the emergence of {sup 231}protactinium (an isotope that only occurs as a fission product of {sup 232}Th) resulting from burning. The study was carried out using data obtained from FSAR (Final Safety Analysis Report) of Angra 2, using the SCALE 6.1, a modeling and simulation nuclear code, especially its ORIGEN-ARP module, which analyzes the depletion of isotopes presents in a reactor. (author)

  11. A Concise Design for the Irradiation of U–10Zr Metallic Fuel at a Very Low Burnup

    Directory of Open Access Journals (Sweden)

    Haibing Guo

    2017-06-01

    Full Text Available In order to investigate the swelling behavior and fuel–cladding interaction mechanism of U–10Zr alloy metallic fuel at very low burnup, an irradiation experiment was concisely designed and conducted on the China Mianyang Research Reactor. Two types of irradiation samples were designed for studying free swelling without restraint and the fuel–cladding interaction mechanism. A new bonding material, namely, pure aluminum powder, was used to fill the gap between the fuel slug and sample shell for reducing thermal resistance and allowing the expansion of the fuel slug. In this paper, the concise irradiation rig design is introduced, and the neutronic and thermal–hydraulic analyses, which were carried out mainly using MCNP (Monte Carlo N-Particle and FLUENT codes, are presented. Out-of-pile tests were conducted prior to irradiation to verify the manufacturing quality and hydraulic performance of the rig. Nondestructive postirradiation examinations using cold neutron radiography technology were conducted to check fuel cladding integrity and swelling behavior. The results of the preliminary examinations confirmed the safety and effectiveness of the design.

  12. A concise design o the irradiation of U-10Zr metallic fuel at a very low burnup

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Hai Bing; Zhou, Wei; Sun, Yong; Qian, Dazhi; Ma, Jimin; Leng, Jun; Huo, Hyoung; Wang, Shaohua [Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang (China)

    2017-06-15

    In order to investigate the swelling behavior and fuel–cladding interaction mechanism of U–10Zr alloy metallic fuel at very low burnup, an irradiation experiment was concisely designed and conducted on the China Mianyang Research Reactor. Two types of irradiation samples were designed for studying free swelling without restraint and the fuel–cladding interaction mechanism. A new bonding material, namely, pure aluminum powder, was used to fill the gap between the fuel slug and sample shell for reducing thermal resistance and allowing the expansion of the fuel slug. In this paper, the concise irradiation rig design is introduced, and the neutronic and thermal–hydraulic analyses, which were carried out mainly using MCNP (Monte Carlo N-Particle) and FLUENT codes, are presented. Out-of-pile tests were conducted prior to irradiation to verify the manufacturing quality and hydraulic performance of the rig. Nondestructive postirradiation examinations using cold neutron radiography technology were conducted to check fuel cladding integrity and swelling behavior. The results of the preliminary examinations confirmed the safety and effectiveness of the design.

  13. Reactors as a Source of Antineutrinos: Effects of Fuel Loading and Burnup for Mixed-Oxide Fuels

    Science.gov (United States)

    Bernstein, Adam; Bowden, Nathaniel S.; Erickson, Anna S.

    2018-01-01

    In a conventional light-water reactor loaded with a range of uranium and plutonium-based fuel mixtures, the variation in antineutrino production over the cycle reflects both the initial core fissile inventory and its evolution. Under an assumption of constant thermal power, we calculate the rate at which antineutrinos are emitted from variously fueled cores, and the evolution of that rate as measured by a representative ton-scale antineutrino detector. We find that antineutrino flux decreases with burnup for low-enriched uranium cores, increases for full mixed-oxide (MOX) cores, and does not appreciably change for cores with a MOX fraction of approximately 75%. Accounting for uncertainties in the fission yields in the emitted antineutrino spectra and the detector response function, we show that the difference in corewide MOX fractions at least as small as 8% can be distinguished using a hypothesis test. The test compares the evolution of the antineutrino rate relative to an initial value over part or all of the cycle. The use of relative rates reduces the sensitivity of the test to an independent thermal power measurement, making the result more robust against possible countermeasures. This rate-only approach also offers the potential advantage of reducing the cost and complexity of the antineutrino detectors used to verify the diversion, compared to methods that depend on the use of the antineutrino spectrum. A possible application is the verification of the disposition of surplus plutonium in nuclear reactors.

  14. Marketing Extension Needs for Sustainable Extension Practices ...

    African Journals Online (AJOL)

    The study investigated the marketing extension needs of cassava farmers in Surulere Local Government Area of Oyo State. Multistage sampling technique was used to select one hundred and five respondents from the list of contact farmers obtained from the state Agricultural Development Programme (ADP). Interview ...

  15. Less extensive surgery compared to extensive surgery

    DEFF Research Database (Denmark)

    Lauszus, Finn F; Petersen, Astrid C; Neumann, Gudrun

    2014-01-01

    OBJECTIVE: To describe the outcome of adult granulosa cell tumor (AGCT) with respect to initial clinical findings, methods of surgery, and perioperative treatment. STUDY DESIGN: Retrospective follow-up study. Setting: All hospitals in Jutland. Sample: 163 women diagnosed with AGCT. Methods: Follo...... with similar survival compared to extensive surgery, but with advancing age conservative surgery increased the risk of relapse and death....

  16. Reducing the fuel temperature for pressure-tube supercritical-water-cooled reactors and the effect of fuel burnup

    Energy Technology Data Exchange (ETDEWEB)

    Nichita, E., E-mail: eleodor.nichita@uoit.ca; Kovaltchouk, V., E-mail: vitali.kovaltchouk@uoit.ca

    2015-12-15

    Highlights: • Typical PT-SCWR fuel uses single-region pins consisting of a homogeneous mixture of ThO{sub 2} and PuO{sub 2}. • Using two regions (central for the ThO{sub 2} and peripheral for the PuO{sub 2}) reduces the fuel temperature. • Single-region-pin melting-to-average power ratio is 2.5 at 0.0 MW d/kg and 2.3 at 40 MW d/kg. • Two-region-pin melting-to-average power ratio is 36 at 0.0 MW d/kg and 10.5 at 40 MW d/kg. • Two-region-pin performance drops with burnup due to fissile-element buildup in the ThO{sub 2} region. - Abstract: The Pressure-Tube Supercritical-Water-Cooled Reactor (PT-SCWR) is one of the concepts under investigation by the Generation IV International Forum for its promise to deliver higher thermal efficiency than nuclear reactors currently in operation. The high coolant temperature (>625 K) and high linear power density employed by the PT-SCWR cause the fuel temperature to be fairly high, leading to a reduced margin to fuel melting, thus increasing the risk of actual melting during accident scenarios. It is therefore desirable to come up with a fuel design that lowers the fuel temperature while preserving the high linear power ratio and high coolant temperature. One possible solution is to separate the fertile (ThO{sub 2}) and fissile (PuO{sub 2}) fuel materials into different radial regions in each fuel pin. Previously-reported work found that by locating the fertile material at the centre and the fissile material at the periphery of the fuel pin, the fuel centreline temperature can be reduced by ∼650 K for fresh fuel compared to the case of a homogeneous (Th–Pu)O{sub 2} mixture for the same coolant temperature and linear power density. This work provides a justification for the observed reduction in fuel centreline temperature and suggests a systematic approach to lower the fuel temperature. It also extends the analysis to the dependence of the radial temperature profile on fuel burnup. The radial temperature profile is

  17. Separation of metallic residues from the dissolution of a high-burnup BWR fuel using nitrogen trifluoride

    Energy Technology Data Exchange (ETDEWEB)

    McNamara, Bruce K. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Buck, Edgar C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Soderquist, Chuck Z. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Smith, Frances N. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Mausolf, Edward J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Scheele, Randall D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2014-03-23

    Nitrogen trifluoride (NF3) was used to fluorinate the metallic residue from the dissolution of a high burnup, boiling water reactor fuel (~70 MWd/kgU). The metallic residue included the noble metal phase (containing ruthenium, rhodium, palladium, technetium, and molybdenum), and smaller amounts of zirconium, selenium, tellurium, and silver. Exposing the noble metal phase to 10% NF3 in argon between 400 and 550°C, removed molybdenum and technetium near 400°C as their volatile fluorides, and ruthenium near 500C as its volatile fluoride. The events were thermally and temporally distinct and the conditions specified are a recipe to separate these transition metals from each other and from the noble metal phase nonvolatile residue. Depletion of the volatile fluorides resulted in substantial exothermicity. Thermal excursion behavior was recorded under non-adiabatic, isothermal conditions that typically minimize heat release. Physical characterization of the metallic noble phase and its thermal behavior are consistent with high kinetic velocity reactions encouraged by the nanoparticulate phase or perhaps catalytic influences of the mixed platinum metals with nearly pure phase structure. Post-fluorination, only two phases were present in the residual nonvolatile fraction. These were identified as a nano-crystalline, metallic palladium cubic phase and a hexagonal rhodium trifluoride (RhF3) phase. The two phases were distinct as the sub-µm crystallites of metallic palladium were in contrast to the RhF3 phase, which grew from the parent nano-crystalline noble-metal phase during fluorination, to acicular crystals exceeding 20-µm in length.

  18. Determination of Fission Gas Inclusion Pressures in High Burnup Nuclear Fuel using Laser Ablation ICP-MS combined with SEM/EPMA and Optical Microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Horvath, Matthias I.; Guenther-Leopold, Ines; Kivel, Niko; Restani, Renato [Laboratory for Materials Behavior, Nuclear Energy and Safety, Paul Scherrer Institut, Villigen, CH-5232 (Switzerland); Guillong, Marcel [Institute for Isotope Geology/Mineralogic Elements, ETH Zuerich, CH-8092 (Switzerland); Izmer, Andrei [Environmental and Resource Studies, Trent University, Peterborough, K9J 7B8 (Canada); Hellwig, Christian [Nuclear Technology Department, Nordostschweizerische Kraftwerke AG (NOK), Baden, CH-5401 (Switzerland); Guenther, Detlef [Laboratory for Inorganic Chemistry, Trace Elements and Microanalysis Group, ETH Zuerich, CH-8093 (Switzerland)

    2008-07-01

    In approximately 20% of all fissions at least one of the fission products is gaseous. These are mainly xenon and krypton isotopes contributing up to 90% by the xenon isotopes. Upon reaching a burn-up of 60 - 75 GWd/tHM a so called High Burnup Structure (HBS) is formed in the cooler rim of the fuel. In this region a depletion of the noble fission gases (FG) in the matrix and an enrichment of FG in {mu}m-sized pores can be observed. Recent calculations show that in these pores the pressure at room temperature can be as large as 30 MPa. The knowledge of the FG pressure in pores is important to understand the high burn-up fuel behavior under accident conditions (i.e. RIA or LOCA). With analytical methods routinely used for the characterization of solid samples, i.e. Electron Probe Micro Analysis (EPMA), Secondary Ion Mass Spectrometry (SIMS), the quantification of gaseous inclusions is very difficult to almost impossible. The combination of a laser ablation system (LA) with an inductively coupled plasma mass spectrometer (ICP-MS) offers a powerful tool for quantification of the gaseous pore inventory. This method offers the advantages of high spatial resolution with laser spot sizes down to 10 {mu}m and low detection limits. By coupling with scanning electron microscopy (SEM) for the pore size distribution, EPMA for the FG inventory in the fuel matrix and optical microscopy for the LA-crater sizes, the pressures in the pores and porosity was calculated. As a first application of this calibration technique for gases, measurements were performed on pressurized water reactor (PWR) fuel with a rod average of 105 GWd/tHM to determine the local FG pressure distribution. (authors)

  19. Kentucky's Urban Extension Focus

    Science.gov (United States)

    Young, Jeffery; Vavrina, Charles

    2014-01-01

    Defining the success of Urban Extension units is sometimes challenging. For those Extension agents, specialists, administrators, and others who have worked to bring solid, research-based programming to urban communities, it is no surprise that working in these communities brings its own unique and sometimes difficult challenges. Kentucky's Urban…

  20. Priorities for Extension.

    Science.gov (United States)

    Hayward, J. A.

    Agricultural extension is one component in an array including research, training, education, marketing, international trade, etc. which develop together to bring about growth, and sustained growth determines the priorities for extension. These priorities depend inevitably on the stage of development of a country or region, and on the current…

  1. University Extension Before 1915

    Science.gov (United States)

    Eklund, Lowell R.

    1976-01-01

    The author traces university extension from its elite English roots to evolving forces toward democratization of educational opportunities and the simultaneous emergence of similar American programs such as library-related night schools, the Lyceum movement, Chataqua, the Philadelphia Society for Extension of University Teaching, and the…

  2. Experiment Safety Assurance Package for the 40- to 52-GWd/MT Burnup Phase of Mixed Oxide Fuel Irradiation in Small I-hole Positions in the Advanced Test Reactor

    Energy Technology Data Exchange (ETDEWEB)

    S. T. Khericha; R. C. Pedersen

    2003-09-01

    This experiment safety assurance package (ESAP) is a revision of the last mixed uranium and plutonium oxide (MOX) ESAP issued in June 2002). The purpose of this revision is to provide a basis to continue irradiation up to 52 GWd/MT burnup [as predicted by MCNP (Monte Carlo N-Particle) transport code The last ESAP provided basis for irradiation, at a linear heat generation rate (LHGR) no greater than 9 kW/ft, of the highest burnup capsule assembly to 50 GWd/MT. This ESAP extends the basis for irradiation, at a LHGR no greater than 5 kW/ft, of the highest burnup capsule assembly from 50 to 52 GWd/MT.

  3. Algebraic extensions of fields

    CERN Document Server

    McCarthy, Paul J

    1991-01-01

    ""...clear, unsophisticated and direct..."" - MathThis textbook is intended to prepare graduate students for the further study of fields, especially algebraic number theory and class field theory. It presumes some familiarity with topology and a solid background in abstract algebra. Chapter 1 contains the basic results concerning algebraic extensions. In addition to separable and inseparable extensions and normal extensions, there are sections on finite fields, algebraically closed fields, primitive elements, and norms and traces. Chapter 2 is devoted to Galois theory. Besides the fundamenta

  4. Dettol: Managing Brand Extensions

    OpenAIRE

    Anand Kumar Jaiswal; Arpita Srivastav; Dhwani Kothari

    2009-01-01

    This case is about evolution of a parent brand and its subsequent extensions into different product categories. Dettol as a brand has immense trust and loyalty from the consumers. Since the 1930s when Dettol was introduced in India, it has occupied a distinct position in the mind of its consumers. To achieve fast growth and leverage the strong brand equity of Dettol, Reckitt Benckiser India Limited (RBIL) rolled out a number of brand extensions. Some of these extensions such as Dettol soap an...

  5. Modeling of PWR fuel at extended burnup; Estudo de modelos para o comportamento a altas queimas de varetas combustiveis de reatores a agua leve pressurizada

    Energy Technology Data Exchange (ETDEWEB)

    Dias, Raphael Mejias

    2016-11-01

    This work studies the modifications implemented over successive versions in the empirical models of the computer program FRAPCON used to simulate the steady state irradiation performance of Pressurized Water Reactor (PWR) fuel rods under high burnup condition. In the study, the empirical models present in FRAPCON official documentation were analyzed. A literature study was conducted on the effects of high burnup in nuclear fuels and to improve the understanding of the models used by FRAPCON program in these conditions. A steady state fuel performance analysis was conducted for a typical PWR fuel rod using FRAPCON program versions 3.3, 3.4, and 3.5. The results presented by the different versions of the program were compared in order to verify the impact of model changes in the output parameters of the program. It was observed that the changes brought significant differences in the results of the fuel rod thermal and mechanical parameters, especially when they evolved from FRAPCON-3.3 version to FRAPCON-3.5 version. Lower temperatures, lower cladding stress and strain, lower cladding oxide layer thickness were obtained in the fuel rod analyzed with the FRAPCON-3.5 version. (author)

  6. Type extension trees

    DEFF Research Database (Denmark)

    Jaeger, Manfred

    2006-01-01

    We introduce type extension trees as a formal representation language for complex combinatorial features of relational data. Based on a very simple syntax this language provides a unified framework for expressing features as diverse as embedded subgraphs on the one hand, and marginal counts of at...... of attribute values on the other. We show by various examples how many existing relational data mining techniques can be expressed as the problem of constructing a type extension tree and a discriminant function....

  7. Timed Extensions for SDL

    OpenAIRE

    Bozga, Marius; Graf, Susanne; Mounier, Laurent; Ober, Iulian; Roux, Jean-Luc; Vincent, Daniel

    2001-01-01

    International audience; In this paper we propose some extensions necessary to enable the specification and description language SDL to become an appropriate formalism for the design of real-time and embedded systems. The extensions we envisage concern both roles of SDL: First, in order to make SDL a real-time specification language, allowing to correctly simulate and verify real-time specifications, we propose a set of annotations to express in a flexible way assumptions and assertions on tim...

  8. Gamut extension for cinema

    OpenAIRE

    Zamir, Syed Waqas,; Vazquez-Corral, Javier; Bertalmío, Marcelo

    2017-01-01

    Emerging display technologies are able to produce images with a much wider color gamut than those of conventional distribution gamuts for cinema and TV, creating an opportunity for the development of gamut extension algorithms (GEAs) that exploit the full color potential of these new systems. In this paper, we present a novel GEA, implemented as a PDE-based optimization procedure related to visual perception models, that performs gamut extension (GE) by taking into account the analysis of dis...

  9. Android Access Control Extension

    Directory of Open Access Journals (Sweden)

    Anton Baláž

    2015-12-01

    Full Text Available The main objective of this work is to analyze and extend security model of mobile devices running on Android OS. Provided security extension is a Linux kernel security module that allows the system administrator to restrict program's capabilities with per-program profiles. Profiles can allow capabilities like network access, raw socket access, and the permission to read, write, or execute files on matching paths. Module supplements the traditional Android capability access control model by providing mandatory access control (MAC based on path. This extension increases security of access to system objects in a device and allows creating security sandboxes per application.

  10. The Non-Destructive Determination of Burn-Up by Means of the Pr{sup l44} 2.18 M Gamma Activity

    Energy Technology Data Exchange (ETDEWEB)

    Forsyth, R.S.; Blackadder, W.H.

    1965-05-15

    In recent years, gamma scanning has been used at several establishments for the determination of the burn-up profile along irradiated fuel elements, the 0.75 MeV gamma from Zr-95/Nb-95 being most often employed as the monitored radiation. Difficulties in establishing the geometry and the self-absorption of the gamma activity in the fuel have tended to prevent the application of the method to quantitative burn-up determination, which has usually been carried out by dissolution of selected portions of the fuel followed by conventional fission product separation or by uranium depletion methods. The present paper describes experiments carried out to calibrate a gamma scanner for quantitative measurements by counting the 2.18 MeV gamma activity due to Pr-144, the short-lived daughter of Ce-144 (t{sub 1/2} = 285 days) from selected pellets in several UO{sub 2} fuel specimens. Accurate burn-up values were then determined by dissolution and application of the isotopic dilution method, using stable molybdenum fission products. The elements, which were rotated about their longitudinal axes to minimize asymmetry effects, were viewed by a sodium iodide crystal and a multichannel analyser through a suitable collimator. Correction for attenuation of the gamma activity (much less than for 0.75 MeV) in the fuel elements which were of different diameters (12.6 to 15.04 mm) was made by applying relative attenuation factors and the effective geometry factor of the instrument was determined. In order to check the corrections applied, the counter factor was also calculated, for the 0.75 MeV activity from Zr-95/Nb-95 and in certain cases for the 0.66 MeV activity from Cs-137. The results obtained, demonstrate that at least over the range of diameters and cooling times used the method is suitable for quantitative determinations. Preliminary experiments to explore the possibility of using the high energy gammas (2.35, 2.65 MeV) from Rh-106 as a method for estimating the fraction of

  11. Analyses of PWR spent fuel composition using SCALE and SWAT code systems to find correction factors for criticality safety applications adopting burnup credit

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Hee Sung; Suyama, Kenya; Mochizuki, Hiroki; Okuno, Hiroshi; Nomura, Yasushi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2001-01-01

    The isotopic composition calculations were performed for 26 spent fuel samples from the Obrigheim PWR reactor and 55 spent fuel samples from 7 PWR reactors using the SAS2H module of the SCALE4.4 code system with 27, 44 and 238 group cross-section libraries and the SWAT code system with the 107 group cross-section library. For the analyses of samples from the Obrigheim PWR reactor, geometrical models were constructed for each of SCALE4.4/SAS2H and SWAT. For the analyses of samples from 7 PWR reactors, the geometrical model already adopted in the SCALE/SAS2H was directly converted to the model of SWAT. The four kinds of calculation results were compared with the measured data. For convenience, the ratio of the measured to calculated values was used as a parameter. When the ratio is less than unity, the calculation overestimates the measurement, and the ratio becomes closer to unity, they have a better agreement. For many important nuclides for burnup credit criticality safety evaluation, the four methods applied in this study showed good coincidence with measurements in general. More precise observations showed, however: (1) Less unity ratios were found for Pu-239 and -241 for selected 16 samples out of the 26 samples from the Obrigheim reactor (10 samples were deselected because their burnups were measured with Cs-137 non-destructive method, less reliable than Nd-148 method the rest 16 samples were measured with); (2) Larger than unity ratios were found for Am-241 and Cm-242 for both the 16 and 55 samples; (3) Larger than unity ratios were found for Sm-149 for the 55 samples; (4) SWAT was generally accompanied by larger ratios than those of SAS2H with some exceptions. Based on the measured-to-calculated ratios for 71 samples of a combined set in which 16 selected samples and 55 samples were included, the correction factors that should be multiplied to the calculated isotopic compositions were generated for a conservative estimate of the neutron multiplication factor

  12. Mobile Applications for Extension

    Science.gov (United States)

    Drill, Sabrina L.

    2012-01-01

    Mobile computing devices (smart phones, tablets, etc.) are rapidly becoming the dominant means of communication worldwide and are increasingly being used for scientific investigation. This technology can further our Extension mission by increasing our power for data collection, information dissemination, and informed decision-making. Mobile…

  13. Selecting Extensive Reading Materials

    Science.gov (United States)

    Jacobs, George M.

    2014-01-01

    This article offers guidance to teachers and students in selecting materials for extensive reading (ER). First, the article explains characteristics of ER and reviews some of the potential gains for students who do ER. Second, the article considers criteria for teachers to bear in mind when selecting ER materials. Third, the article then suggests…

  14. Preliminary Content Evaluation of the North Anna High Burn-Up Sister Fuel Rod Segments for Transportation in the 10-160B and NAC-LWT

    Energy Technology Data Exchange (ETDEWEB)

    Ketusky, E. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-08-09

    The U.S. Department of Energy’s (DOE’s) Used Fuel Disposition Campaign (UFDC) Program has transported high-burnup nuclear sister fuel rods from a commercial nuclear power plant for purposes of evaluation and testing. The evaluation and testing of high-burnup used nuclear fuel is integral to DOE initiatives to collect information useful in determining the integrity of fuel cladding for future safe transportation of the fuel, and for determining the effects of aging, on the integrity of UNF subjected to extended storage and subsequent transportation. The UFDC Program, in collaboration with the U.S. Nuclear Regulatory Commission and the commercial nuclear industry, has obtained individual used nuclear fuel rods for testing. The rods have been received at Oak Ridge National Laboratory (ORNL) for both separate effects testing (SET) and small-scale testing (SST). To meet the research objectives, testing on multiple 6 inch fuel rod pins cut from the rods at ORNL will be performed at Pacific Northwest National Laboratory (PNNL). Up to 10 rod equivalents will be shipped. Options were evaluated for multiple shipments using the 10-160B (based on 4.5 rod equivalents) and a single shipment using the NAC-LWT. Based on the original INL/Virginia Power transfer agreement, the rods are assumed to 152 inches in length with a 0.374-inch diameter. This report provides a preliminary content evaluation for use of the 10-160B and NAC-LWT for transporting those fuel rod pins from ORNL to PNNL. This report documents the acceptability of using these packagings to transport the fuel segments from ORNL to PNNL based on the following evaluations: enrichment, A2 evaluation, Pu-239 FGE evaluation, heat load, shielding (both gamma and neutron), and content weight/structural evaluation.

  15. Gamut Extension for Cinema.

    Science.gov (United States)

    Zamir, Syed Waqas; Vazquez-Corral, Javier; Bertalmio, Marcelo

    2017-04-01

    Emerging display technologies are able to produce images with a much wider color gamut than those of conventional distribution gamuts for cinema and TV, creating an opportunity for the development of gamut extension algorithms (GEAs) that exploit the full color potential of these new systems. In this paper, we present a novel GEA, implemented as a PDE-based optimization procedure related to visual perception models, that performs gamut extension (GE) by taking into account the analysis of distortions in hue, chroma, and saturation. User studies performed using a digital cinema projector under cinematic (low ambient light, large screen) conditions show that the proposed algorithm outperforms the state of the art, producing gamut extended images that are perceptually more faithful to the wide-gamut ground truth, as well as free of color artifacts and hue shifts. We also show how currently available image quality metrics, when applied to the GE problem, provide results that do not correlate with users' choices.

  16. attitude of extension personnel to training and visit extension system ...

    African Journals Online (AJOL)

    ISAAC E. ILEVBAOJE. ABSTRACT. This study was undertaken to find out the attitudes of extension workers to the training and visit (T&V) extension system as a complimentary step to specify if this extension approach is on course in Nigeria. Results obtained indicate that about 10. 8, 65.8 and 23.3% of the extension ...

  17. Impact of neutron thermal scattering laws on the burn-up analysis of supercritical LWR's fuel assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Conti, Andrea

    2011-10-15

    . The third, most naive option is called the ''free gas approximation''. It is the goal of this work to make an estimate of the criticality calculations' inaccuracy due to the inadequate employed physical model and to determine which one of the available models can be the best replacement. The accuracy of criticality calculations referring to the HPLWR is a problem that had already been raised by Waata in 2006. In her Ph.D. thesis Waata reports having carried out MCNP runs referring to an HPLWR fuel element employing the free gas approximation. In her thesis Waata explicitly sifts through the factors that can affect her MCNP runs' accuracy, but leaves the inappropriate thermal treatment completely out. In this work, the inaccuracy of the criticality calculations has been investigated carrying out sets of similar burn-up calculations differing from each other only in the applied thermal cross section sets. The widest discrepancies were detected between the results obtained applying the free gas model and those obtained applying the molecular models. This, in conjunction with the fact that the free gas model does not even keep in count the molecular structure of H{sub 2}O suggest to discard it and to focus the investigation on the vapour and liquid models. Dr. J. Marti, from the Universitat Politecnica de Catalunya, Barcelona, Spain registered the generalized frequency distributions obtained from the molecular dynamics simulations of 216 molecules of H{sub 2}O in 10 simulated supercritical states and published in an article (1999) the frequencies of the three characteristic distribution peaks for each simulated state, in numerical format. A confrontation with the corresponding peaks from Bernnat's available frequency distributions for liquid water and vapour revealed the peaks of the latter to be closest to the supercritical water ones in nearly all cases. Hence the inference that thermal cross section sets for vapour are for the time

  18. Selecting Extensive Reading Materials

    Directory of Open Access Journals (Sweden)

    George M Jacobs

    2014-05-01

    Full Text Available This article offers guidance to teachers and students in selecting materials for extensive reading (ER. First, the article explains characteristics of ER and reviews some of the potential gains for students who do ER. Second, the article considers criteria for teachers to bear in mind when selecting ER materials. Third, the article then suggests ways that teachers and students can find ER materials. Fourth, guidance is provided to students for when they select what to read from among the ER materials available to them. Finally, advice is given on integrating ER with course textbooks.

  19. Open Extension Topology

    Directory of Open Access Journals (Sweden)

    Вячеслав Бабич

    2015-10-01

    Full Text Available The paper contains the results which describe the properties of such general topological construction as open extension topology. In particular, we prove that this topology is not transitive. We find the base of the least cardinality for the topology and local one for the neighborhood system of every point. We calculate the interior, the closure, and the sets of isolated and limit points of any set. Also we prove that this space is path connected and is not metrizable, and investigate its cardinal invariants and separation axioms.

  20. Extensive air showers

    CERN Document Server

    Rao, M V S

    1997-01-01

    Ultrahigh energy cosmic rays carry information about their sources and the intervening medium apart from providing a beam of particles for studying certain features of high energy interactions currently inaccessible at man-made accelerators. They can at present be studied only via the extensive air showers (EAS's) they generate while passing through the Earth's atmosphere, since their fluxes are too low for the experiments of limited capability flown in balloons and satellites. The EAS is generated by a series of interactions of the primary cosmic ray and its progeny with the atmospheric nucle

  1. Attitude Of Extension Personnel To Training And Visit Extension ...

    African Journals Online (AJOL)

    In order to make the attitudes of extension workers more affirmative, the paper recommended, inter alia, staff motivation, minimizing political and administrative interference in staff work and a reasonable reduction in the work load of extension staff. Key words: attitude, extension personnel, training and visit. Journal of ...

  2. The effect of dissolved hydrogen on the dissolution of {sup 233}U doped UO{sub 2}(s) high burn-up spent fuel and MOX fuel

    Energy Technology Data Exchange (ETDEWEB)

    Carbol, P. [Inst. for Transuranium Elements, Karlsruhe (Germany); Spahiu, K. (ed.) [and others

    2005-03-01

    In this report the results of the experimental work carried out in a large EU-research project (SFS, 2001-2004) on spent fuel stability in the presence of various amounts of near field hydrogen are presented. Studies of the dissolution of {sup 233}U doped UO{sub 2}(s) simulating 'old' spent fuel were carried out as static leaching tests, autoclave tests with various hydrogen concentrations and electrochemical tests. The results of the leaching behaviour of a high burn-up spent fuel pellet in 5 M NaCl solutions in the presence of 3.2 bar H{sub 2} pressure and of MOX fuel in dilute synthetic groundwater under 53 bar H{sub 2} pressure are also presented. In all the experimental studies carried out in this project, a considerable effect of hydrogen in the dissolution rates of radioactive materials was observed. The experimental results obtained in this project with a-doped UO{sub 2}, high burn-up spent fuel and MOX fuel together with literature data give a reliable background to use fractional alteration/dissolution rates for spent fuel of the order of 10{sup -6}/yr - 10{sup -8}/yr with a recommended value of 4x10{sup -7}/yr for dissolved hydrogen concentrations above 10{sup -3} M and Fe(II) concentrations typical for European repository concepts. Finally, based on a review of the experimental data and available literature data, potential mechanisms of the hydrogen effect are also discussed. The work reported in this document was performed as part of the Project SFS of the European Commission 5th Framework Programme under contract no FIKW-CT-2001-20192 SFS. It represents the deliverable D10 of the experimental work package 'Key experiments using a-doped UO{sub 2} and real spent fuel', coordinated by SKB with the participation of ITU, FZK-INE, ENRESA, CIEMAT, ARMINES-SUBATECH and SKB.

  3. Studies on validation possibilities for computational codes for criticality and burnup calculations of boiling water reactor fuel; Untersuchungen zu Validierungsmoeglichkeiten von Rechencodes fuer Kritikalitaets- und Abbrandrechnungen von Siedewasserreaktor-Brennstoff

    Energy Technology Data Exchange (ETDEWEB)

    Behler, Matthais; Hannstein, Volker; Kilger, Robert; Sommer, Fabian; Stuke, Maik

    2017-06-15

    The Application of the method of Burn-up Credit on Boiling Water Reactor fuel is much more complex than in the case of Pressurized Water Reactors due to the increased heterogeneity and complexity of the fuel assemblies. Strongly varying enrichments, complex fuel assembly geometries, partial length fuel rods, and strong axial variations of the moderator density make the verification of conservative irradiation conditions difficult. In this Report, it was investigated whether it is possible to take into account the burn-up in criticality analyses for systems with irradiated Boiling Water Reactor fuel on the basis of freely available experimental data and by additionally applying stochastic methods. In order to achieve this goal, existing methods for stochastic analysis were adapted and further developed in order to being applicable to the specific conditions needed in Boiling Water Reactor analysis. The aim was to gain first insight whether a workable scheme for using burn-up credit in Boiling Water Reactor applications can be derived. Due to the fact that the different relevant quantities, like e.g. moderator density and the axial power profile, are strongly correlated, the GRS-tool SUnCISTT for Monte-Carlo uncertainty quantification was used in the analysis. This tool was coupled to a simplified, consistent model for the irradiation conditions. In contrast to conventional methods, this approach allows to simultaneously analyze all involved effects.

  4. Heterogeneous UO{sub 2} fuel irradiated up to a high burn-up: Investigation of the HBS and of fission product releases

    Energy Technology Data Exchange (ETDEWEB)

    Noirot, J., E-mail: jean.noirot@cea.fr [CEA, DEN, DEC, Cadarache, F-13108 St. Paul Lez Durance (France); Lamontagne, J. [CEA, DEN, DEC, Cadarache, F-13108 St. Paul Lez Durance (France); Nakae, N. [JNES, Toranomon Towers Office, 4-1-28, Toranomon, Minato-ku, Tokyo 105-0001 (Japan); Kitagawa, T. [MNF, 622-1 Funaishikawa, Tokai-mura, Naka-gun, Ibaraki 319-1197 (Japan); Kosaka, Y. [NDC, 622-12 Funaishikawa, Tokai-mura, Ibaraki 319-1111 (Japan); Tverberg, T. [IFE, P.O. Box 173, NO-1751 Halden (Norway)

    2013-11-15

    A UO{sub 2} fuel with a heterogeneous distribution of {sup 235}U was irradiated up to a high burn-up in the Halden Boiling Water Reactor (HBWR). The last 100 days of irradiation were performed with an increased level of linear power. The effect of the heterogeneous fissile isotope distribution on the formation of the HBS was studied free of the possible influence of Pu which exists in heterogeneous MOX fuels. The HBS formed in {sup 235}U-rich agglomerates and its main characteristics were very similar to those of the HBS formed in Pu-rich agglomerates of heterogeneous MOX fuels. The maximum local contents of Nd and Xe before HBS formation were studied in this fuel. In addition to a Pu effect that promotes the HBS phenomenon, comparison with previous results for heterogeneous MOX fuels showed that the local fission product concentration was not the only parameter that has to be taken into consideration. It appears that the local actinide depletion by fission and/or the energy locally deposited through electronic interactions in the fission fragment recoils also have an effect on the HBS formation threshold. Moreover, a major release of fission gases from the peripheral {sup 235}U-rich agglomerates of HBS bubbles and a Cs radial movement are also evidenced in this heterogeneous UO{sub 2}. Cs deposits on the peripheral grain boundaries, including the HBS grain boundaries, are considered to reveal the release paths.

  5. A Study on the Radiation Source Effect to the Radiation Shielding Analysis for a Spent-Fuel Cask Design with Burnup-Credit

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Soon Young; Kim, Kyung O [RADCORE Co., Ltd., Daejeon (Korea, Republic of); Ko, Jae Hoon; Lee, Gang Gu [Korea Nuclear Engineering and Service Corp., Daejeon (Korea, Republic of); Kim, Tae Man; Yoon, Jeong Hyun [Korea Raioactive waste Management Corp., Daejeon (Korea, Republic of)

    2011-06-15

    The radiation shielding analysis for a Burnup-credit (BUC) cask designed under the management of Korea Radioactive Waste Management Corporation (KRMC) was performed to examine the contribution of each radiation source affecting dose rate distribution around the cask. Various radiation sources, which contain neutron and gamma-ray sources placed in active fuel region and the activation source, and imaginary nuclear fuel were all considered in the MCNP calculation model to realistically simulate the actual situations. It was found that the maximum external and surface dose rates of the spent fuel cask were satisfied with the domestic standards both in normal and accident conditions. In normal condition, the radiation dose rate distribution around the cask was mainly influenced by activation source (60 Co radioisotope); in another case, the neutron emitted in active fuel region contributed about 90% to external dose rate at 1m distance from side surface of the cask. Besides, the contribution level of activation source was dramatically increased to the dose rates in top and bottom regions of the cask. From this study, it was recognized that the detailed investigation on the radiation sources should be performed conservatively and accurately in the process of radiation shielding analysis for a BUC cask.

  6. Direct Measurement of Initial Enrichment and Burn-up of Spent Fuel Assembly with a Differential Die-Away Technique Based Instrument

    Energy Technology Data Exchange (ETDEWEB)

    Henzl, Vladimir [Los Alamos National Laboratory; Swinhoe, Martyn T. [Los Alamos National Laboratory; Tobin, Stephen J. [Los Alamos National Laboratory

    2012-07-16

    A key objective of the Next Generation Safeguards Initiative (NGSI) is to utilize non-destructive assay (NDA) techniques to determine the elemental plutonium (Pu) content in a commercial-grade nuclear spent fuel assembly (SFA). In the third year of the NGSI Spent Fuel NDA project, the research focus is on the integration of a few NDA techniques. One of the reoccurring challenges to the accurate determination of Pu content has been the explicit dependence of the measured signal on the presence of neutron absorbers which build up in the assembly in accordance with its operating and irradiation history. The history of any SFA is often summarized by the parameters of burn-up (BU), initial enrichment (IE) and cooling time (CT). While such parameters can typically be provided by the operator, the ability to directly measure and verify them would significantly enhance the autonomy of the IAEA inspectorate. Within this paper, we demonstrate that an instrument based on a Differential Die-Away technique is in principle capable of direct measurement of IE and, should the CT be known, also the BU.

  7. attitude of extension personnel to training and visit extension system ...

    African Journals Online (AJOL)

    the training and visit (T&V) extension system as a complimentary step to specify if this extension approach is ... at 5 percent level of probability, the mean score for the project headquarters staff (106.25) was highest while ... which offered them the opportunity to use their knowledge and skills. Asiabiaka (1991) studied women ...

  8. Robotic hand with modular extensions

    Energy Technology Data Exchange (ETDEWEB)

    Salisbury, Curt Michael; Quigley, Morgan

    2015-01-20

    A robotic device is described herein. The robotic device includes a frame that comprises a plurality of receiving regions that are configured to receive a respective plurality of modular robotic extensions. The modular robotic extensions are removably attachable to the frame at the respective receiving regions by way of respective mechanical fuses. Each mechanical fuse is configured to trip when a respective modular robotic extension experiences a predefined load condition, such that the respective modular robotic extension detaches from the frame when the load condition is met.

  9. Think - Baltic Extension / Kalle Kask

    Index Scriptorium Estoniae

    Kask, Kalle

    2002-01-01

    Tallinna TÜ Rehabilitatsiooni tehnoloogia keskus korraldas pressikonverentsi, kus tutvustati osalemist EL V raamprogrammis Think - Baltic Extension, mis on suunatud puuetega inimeste tööhõive tagamisele

  10. Extensive Reading Coursebooks in China

    Science.gov (United States)

    Renandya, Willy A.; Hu, Guangwei; Xiang, Yu

    2015-01-01

    This article reports on a principle-based evaluation of eight dedicated extensive reading coursebooks published in mainland China and used in many universities across the country. The aim is to determine the extent to which these coursebooks reflect a core set of nine second language acquisition and extensive reading principles. Our analysis shows…

  11. Fuzzy extended preferences: fuzzified extension

    OpenAIRE

    Montero, Javier

    1988-01-01

    This paper deals with decision-making problems where a fuzzy preference relation with no unfuzzy nondominated alternatives has been defined. While in the first part randomized extension was considered in order to get a solution, in this second part an aggregative approach to fuzzified extension will be developed.

  12. Frames and extension problems I

    DEFF Research Database (Denmark)

    Christensen, Ole

    2014-01-01

    In this article we present a short survey of frame theory in Hilbert spaces. We discuss Gabor frames and wavelet frames and set the stage for a discussion of various extension principles; this will be presented in the article Frames and extension problems II (joint with H.O. Kim and R.Y. Kim)....

  13. Research-extension-farmer linkages

    African Journals Online (AJOL)

    charged with the role of articulating the most appropriate research and extension systems for Uganda. Following the recommendations of these working groups, national agricultural research and extension strategies and plans were adopted ..... meetings at institutes have been taking place regularly since 1994. These take ...

  14. Homomorphisms between C∗ -algebra extensions

    Indian Academy of Sciences (India)

    -algebra extensions. CHANGGUO WEI. School of Mathematical Sciences, Ocean University of China, Qingdao 266071, ... into the other in general, so we have to consider properties of extension homomorphisms before studying the ..... Theory (Dalhousie Univ., Halifax, N.S., 1973) Lecture Notes in Math. (Berlin: Springer).

  15. EXTENSION WORKERS' OPINIONS REGARDING THE ...

    African Journals Online (AJOL)

    The primary purpose of the study was to determine extension worker's opinions regarding the influence of the National Maize Competition (NAMCOM) on the farmers' agricultural practices and experiences in the Manzini region. A census population of front-line extension workers in charge of the participating areas in ...

  16. Repeat Customer Success in Extension

    Science.gov (United States)

    Bess, Melissa M.; Traub, Sarah M.

    2013-01-01

    Four multi-session research-based programs were offered by two Extension specialist in one rural Missouri county. Eleven participants who came to multiple Extension programs could be called "repeat customers." Based on the total number of participants for all four programs, 25% could be deemed as repeat customers. Repeat customers had…

  17. Journal of Agricultural Extension submitted to Agricultural Extension ...

    African Journals Online (AJOL)

    PROF. MADUKWE

    followed by lack of contact with extension agents (71.7%) and gender ... As women typically confront narrower range of labour markets than men, and lower wage ..... gap in accessibility to productive resources between male and female heads ...

  18. Extensions of the Poincare group

    CERN Document Server

    Antoniadis, Ignatios; Savvidy, George

    2011-01-01

    We construct an extension of the Poincare group which involves a mixture of internal and space-time supersymmetries. The resulting group is an extension of the superPoincare group with infinitely many generators which carry internal and space-time indices. It is a closed algebra since all Jacobi identities are satisfied and it has therefore explicit matrix representations. We investigate the massless case and construct the irreducible representations of the extended symmetry. They are divided into two sets, longitudinal and transversal representations. The transversal representations involve an infinite series of integer and half-integer helicities. Finally we suggest an extension of the conformal group along the same line.

  19. Programming Reactive Extensions and LINQ

    CERN Document Server

    Liberty, Jesse

    2011-01-01

    Pro Reactive Extensions and LINQ is a deep dive into the next important technology for .NET developers: Reactive Extensions. This in-depth tutorial goes beyond what is available anywhere else to teach how to write WPF, Silverlight, and Windows Phone applications using the Reactive Extensions (Rx) to handle events and asynchronous method calls. Reactive programming allows you to turn those aspects of your code that are currently imperative into something much more event-driven and flexible. For this reason, it's sometimes referred to as LINQ for Events. Reactive programming hinges on the concep

  20. Learning Joomla! 3 extension development

    CERN Document Server

    Plummer, Tim

    2013-01-01

    A practical guide with step-by-step examples that build on each other so you can learn by doing and get hands-on knowledge about creating your plugins, modules, and components in Joomla.""Learning Joomla! 3 Extension Development, Third Edition"" is for developers who want to create their own Joomla extensions. It is assumed you will have some basic PHP, HTML, and CSS knowledge, but you don't need any prior Joomla programming experience. This book will also be useful to people who just want to make minor customizations to existing Joomla extensions and build on the work of others in the open so

  1. Horizontal Brand Extension and Customer perception

    OpenAIRE

    Khan, Khalid; Janthimapornkij, Rattanawilai

    2011-01-01

    Company use different method for extended their business to different market and to different segment. They use different method; brand extension is one of popular strategy for extension of business. Brand extension does not become successful for every brand, it is very risky. The purpose of this thesis is to study horizontal brand extension and customer perception. We will discuss horizontal brand extension and its two main types franchise brand extension and line extension. Brand extension ...

  2. Boiler-turbine life extension

    Energy Technology Data Exchange (ETDEWEB)

    Natzkov, S. [TOTEMA, Ltd., Sofia (Bulgaria); Nikolov, M. [CERB, Sofia (Bulgaria)

    1995-12-01

    The design life of the main power equipment-boilers and turbines is about 105 working hours. The possibilities for life extension are after normatively regulated control tests. The diagnostics and methodology for Boilers and Turbines Elements Remaining Life Assessment using up to date computer programs, destructive and nondestructive control of metal of key elements of units equipment, metal creep and low cycle fatigue calculations. As well as data for most common damages and some technical decisions for elements life extension are presented.

  3. Frames and extension problems II

    DEFF Research Database (Denmark)

    Christensen, Ole; Kim, Hong Oh; Kim, Rae Young

    2014-01-01

    This article is a follow-up on the article Frames and Extension Problems I. Here we will go into more recent progress on the topic and also present some open problems.......This article is a follow-up on the article Frames and Extension Problems I. Here we will go into more recent progress on the topic and also present some open problems....

  4. Agricultural extension and mass media.

    Science.gov (United States)

    Perraton, H

    1983-12-01

    To learn more about the use of the mass media for agricultural extension, the World Bank has considered the efforts of 2 units: INADES-formation in West Africa and the Extension Aids Branch of Malawi. The INADES-formation study focuses on Cameroon but also considers work in Rwanda and the Ivory Coast. Some general conclusions emerge from a comparison of the 2 organizations. Malawi operates an extension service which reaches farmers through extension agents, through farmer training centers, and through mass media. The Extension Aids Branch (EAB) has responsibility for its media work and broadcasts 4 1/2 hours of radio each week. Its 6 regular radio programs include a general program which interviews farmers, a music request program in which the music is interspersed with farming advice, a farming family serial, and a daily broadcast of agricultural news and information. The 17 cinema vans show some agricultural films, made by EAB, some entertainment films, and some government information films from departments other than the ministry of agriculture. EAB also has a well-developed program of research and evaluation of its own work. INADES-formation, the training section of INADES, works towards social and economic development of the population. It teaches peasant farmers and extension agents and does this through running face-to-face seminars, by publishing a magazine, "Agripromo," and through correspondence courses. In 1978-79 INADES-formation enrolled some 4500 farmers and extension agents as students. Both of these organizations work to teach farmers better agriculture techniques, and both were created in response to the fact that agricultural extension agents cannot meet all the farmers in their area. Despite the similarity of objective, there are differences in methods and philosophy. The EAB works in a single country and uses a variety of mass media, with print playing a minor role. INADES-formation is an international and nongovernmental organization and its

  5. Development and demonstration of an advanced extended-burnup fuel-assembly design incorporating urania-gadolinia. Second semi-annual progress report, October 1981-March 1982

    Energy Technology Data Exchange (ETDEWEB)

    Newman, L W; Rombough, C T; Thornton, T A

    1982-08-01

    The Babcock and Wilcox Company, Duke Power Company, and the US Department of Energy are participating in an extended-burnup program for pressurized water reactors that will demonstrate an advanced fuel assembly design. This advanced fuel assembly will use a UO/sub 2/-Gd/sub 2/O/sub 3/ burnable-poison fuel mixture along with other state-of-the-art fuel performance and uranium utilization-enhancing design features that include annular pellets, annealed guide tubes, Zircaloy intermediate grids, and removable upper end fittings. Comparisons of the thermal properties of UO/sub 2/-Gd/sub 2/O/sub 3/ specimens containing 2.98, 5.66, and 8.50 wt % Gd/sub 2/O/sub 3/ with UO/sub 2/ specimens showed that thermal conductivity is the only thermal parameter significantly affected by the addition of Gd/sub 2/O/sub 3/. The milling steps used to prepare UO/sub 2/-Gd/sub 2/O/sub 3/ powder result in a powder that is more active than standard UO/sub 2/ powder. As a result, UO/sub 2/-Gd/sub 2/O/sub 3/ fuel has shown more variability than UO/sub 2/ fuel in as-sintered theoretical density and densification behavior. However, a poreforming material, added to the UO/sub 2/-Gd/sub 2/O/sub 3/ powder mixture before sintering, can be used to achieve the desired density. Measured results from critical experiments were compared with predicted data and confirmed the accuracy of the standard two-group diffusion theory model for predicting global and discrete UO/sub 2/-Gd/sub 2/O/sub 3/ effects when cross-section input is appropriately adjusted. The preliminary first two fuel cycles for lead test assemblies of the advanced design were developed. Irradiation of the lead test assemblies is scheduled to begin in 1983 in Duke Power Company's Oconee Unit 1. An intercalibrated movable incore detector system will be used to monitor the performance of the test assemblies during irradiation.

  6. RURAL EXTENSION EPISTEMOLOGY AND THE TIME OF TOTAL EXTENSION

    Directory of Open Access Journals (Sweden)

    Silvio Calgaro Neto

    2016-09-01

    Full Text Available This article is dedicated to explore the field of knowledge related to rural extension. In general, a three complementary perspective is used as theoretical strategy to present this epistemological study. The first perspective, seeks to accomplish a brief archeology of rural extension, identifying the remarkable historical passages. At the second, we look to some theoretical models through the modern epistemological platform. Finally, the third perspective, aims to present a methodological proposal that contemplate this epistemic characteristics, relating with the contemporary transformations observed in the knowledge construction and technological transference for a rural development. Keywords: Total institutions. University.

  7. African Journal of Livestock Extension

    African Journals Online (AJOL)

    African Journal of Livestock Extension aims to bring to the fore the role and significance of livestock in maintaining rural, peri-urban and urban households, vis-à-vis its impact on poverty alleviation, household nutritional status, economic coping strategy and provision of employment. The focus of the journal relates to all ...

  8. Longest common extensions in trees

    DEFF Research Database (Denmark)

    Bille, Philip; Gawrychowski, Pawel; Gørtz, Inge Li

    2016-01-01

    The longest common extension (LCE) of two indices in a string is the length of the longest identical substrings starting at these two indices. The LCE problem asks to preprocess a string into a compact data structure that supports fast LCE queries. In this paper we generalize the LCE problem to t...

  9. Dept. of Agricultural Economics & Extension

    African Journals Online (AJOL)

    duce poverty include education, credit, durable assets, living in the forest belt and in the south of the country. .... underscores the importance of education and extension services in the technology adoption/diffusion process. Poverty is a ...... Detwerminantes de la Pobreza de los hogares, México. Revista Mexicana de ...

  10. Extension Resources for International Trade

    Science.gov (United States)

    Seal, Susan D.

    2016-01-01

    With the opening of additional trade partnerships, the reduction of global transportation and communication costs, and the increase in demand for U.S. agricultural products and services, international trade is an area of great importance to more and more Extension clients and stakeholders. This article provides information about the primary…

  11. Symmetrical Extensions of Dirichlet Operators

    CERN Document Server

    Us, A G

    1997-01-01

    There is constructed and considered the extension of classical Diriclet operator corresponding to uniformly log-concave measure in the space of symmetric differential forms. Sufficient conditions for its essential self-adjointness in one-dimensional case as well as for the same of its "sypersymmetric" part in general situations are given.

  12. Extensiveness of Farmers' Buying Process

    NARCIS (Netherlands)

    Kool, M.; Meulenberg, M.T.G.; Broens, D.F.

    1997-01-01

    In this article we study farmers' buying processes, in particular the selection of a supplier for a given farm input. Extensiveness of farmers' buying processes is defined as the degree information acquisition and alternative evaluation effort carried out to prepare that selection. Hypotheses,

  13. Poincare Algebra Extension with Tensor Generator

    OpenAIRE

    Soroka, Dmitrij V.; Soroka, Vyacheslav A.

    2005-01-01

    A tensor extension of the Poincar\\'e algebra is proposed for the arbitrary dimensions. Casimir operators of the extension are constructed. A possible supersymmetric generalization of this extension is also found in the dimensions $D=2,3,4$.

  14. Tensor extension of the Poincare algebra

    Energy Technology Data Exchange (ETDEWEB)

    Soroka, Dmitrij V. [Kharkov Institute of Physics and Technology, 61108 Kharkov (Ukraine)]. E-mail: dsoroka@kipt.kharkov.ua; Soroka, Vyacheslav A. [Kharkov Institute of Physics and Technology, 61108 Kharkov (Ukraine)]. E-mail: vsoroka@kipt.kharkov.ua

    2005-02-10

    A tensor extension of the Poincare algebra is proposed for the arbitrary dimensions. Casimir operators of the extension are constructed. A possible supersymmetric generalization of this extension is also found in the dimensions D=2,3,4.

  15. Linear programming foundations and extensions

    CERN Document Server

    Vanderbei, Robert J

    2001-01-01

    Linear Programming: Foundations and Extensions is an introduction to the field of optimization. The book emphasizes constrained optimization, beginning with a substantial treatment of linear programming, and proceeding to convex analysis, network flows, integer programming, quadratic programming, and convex optimization. The book is carefully written. Specific examples and concrete algorithms precede more abstract topics. Topics are clearly developed with a large number of numerical examples worked out in detail. Moreover, Linear Programming: Foundations and Extensions underscores the purpose of optimization: to solve practical problems on a computer. Accordingly, the book is coordinated with free efficient C programs that implement the major algorithms studied: -The two-phase simplex method; -The primal-dual simplex method; -The path-following interior-point method; -The homogeneous self-dual methods. In addition, there are online JAVA applets that illustrate various pivot rules and variants of the simplex m...

  16. Extension agents and conflict narratives

    DEFF Research Database (Denmark)

    Bond, Jennifer Lauren

    2016-01-01

    Purpose: This work investigated the narratives of development extensionists in relation to natural resource conflict, in order to understand the competing discourses surrounding the wicked problems of natural resource management in Laikipia County, Kenya. Methodology: Q methodology was used...... to elicit the conflict narratives present among extension professionals. A concourse of 221 statements were devised from interviews and group discussions with key informants and a final sample of 49 statements was used for the sorting. Thirteen Q-sorts were undertaken with among rural extension...... professionals from government, non-government, faith-based and private organizations. Findings: Four factors were elicited from the data, labelled—A: ‘Improved Leadership’; B: ‘Resource-centred conflict’; C: ‘Improved Governance’; and D: ‘Improved Management’. Practical Implications: Narratives of neo...

  17. Rosacea with extensive extrafacial lesions

    OpenAIRE

    Pereira, TM; Vieira, AP; Sousa-Basto, A

    2008-01-01

    Rosacea is a very common skin disorder in the clinical practice that primarily affects the convex areas of the face. Extrafacial rosacea lesions have occasionally been described, but extensive involvement is exceptional. In the absence of its typical clinical or histological features, the diagnosis of extrafacial rosacea may be problematic. We describe an unusual case of rosacea with very exuberant extrafacial lesions, when compared with the limited involvement of the face.

  18. An Extension for ESO Headquarters

    Science.gov (United States)

    Fischer, Robert; Walsh, Jeremy

    2009-03-01

    The ESO Headquarters was completed in 1980, but is now too small to house all the ESO staff and currently only about 50% reside in the original building. A decision was taken to seek an extension to the Headquarters building in close proximity to the current one and a competition was launched for architectural designs. Three designs were shortlisted and the process of selection for the final design is described. Construction will begin in 2010 and is due for completion in 2012.

  19. Determining initial enrichment, burnup, and cooling time of pressurized-water-reactor spent fuel assemblies by analyzing passive gamma spectra measured at the Clab interim-fuel storage facility in Sweden

    Science.gov (United States)

    Favalli, A.; Vo, D.; Grogan, B.; Jansson, P.; Liljenfeldt, H.; Mozin, V.; Schwalbach, P.; Sjöland, A.; Tobin, S. J.; Trellue, H.; Vaccaro, S.

    2016-06-01

    The purpose of the Next Generation Safeguards Initiative (NGSI)-Spent Fuel (SF) project is to strengthen the technical toolkit of safeguards inspectors and/or other interested parties. The NGSI-SF team is working to achieve the following technical goals more easily and efficiently than in the past using nondestructive assay measurements of spent fuel assemblies: (1) verify the initial enrichment, burnup, and cooling time of facility declaration; (2) detect the diversion or replacement of pins; (3) estimate the plutonium mass [which is also a function of the variables in (1)]; (4) estimate the decay heat; and (5) determine the reactivity of spent fuel assemblies. Since August 2013, a set of measurement campaigns has been conducted at the Central Interim Storage Facility for Spent Nuclear Fuel (Clab), in collaboration with Swedish Nuclear Fuel and Waste Management Company (SKB). One purpose of the measurement campaigns was to acquire passive gamma spectra with high-purity germanium and lanthanum bromide scintillation detectors from Pressurized Water Reactor and Boiling Water Reactor spent fuel assemblies. The absolute 137Cs count rate and the 154Eu/137Cs, 134Cs/137Cs, 106Ru/137Cs, and 144Ce/137Cs isotopic ratios were extracted; these values were used to construct corresponding model functions (which describe each measured quantity's behavior over various combinations of burnup, cooling time, and initial enrichment) and then were used to determine those same quantities in each measured spent fuel assembly. The results obtained in comparison with the operator declared values, as well as the methodology developed, are discussed in detail in the paper.

  20. Determining initial enrichment, burnup, and cooling time of pressurized-water-reactor spent fuel assemblies by analyzing passive gamma spectra measured at the Clab interim-fuel storage facility in Sweden

    Energy Technology Data Exchange (ETDEWEB)

    Favalli, A., E-mail: afavalli@lanl.gov [Los Alamos National Laboratory, Los Alamos, NM (United States); Vo, D. [Los Alamos National Laboratory, Los Alamos, NM (United States); Grogan, B. [Oak Ridge National Laboratory, Oak Ridge, TN (United States); Jansson, P. [Uppsala University, Uppsala (Sweden); Liljenfeldt, H. [Oak Ridge National Laboratory, Oak Ridge, TN (United States); Mozin, V. [Lawrence Livermore National Laboratory, Livermore, CA (United States); Schwalbach, P. [European Commission, DG Energy, Euratom Safeguards Luxemburg, Luxemburg (Luxembourg); Sjöland, A. [Swedish Nuclear Fuel and Waste Management Company, Stockholm (Sweden); Tobin, S.J.; Trellue, H. [Los Alamos National Laboratory, Los Alamos, NM (United States); Vaccaro, S. [European Commission, DG Energy, Euratom Safeguards Luxemburg, Luxemburg (Luxembourg)

    2016-06-01

    The purpose of the Next Generation Safeguards Initiative (NGSI)–Spent Fuel (SF) project is to strengthen the technical toolkit of safeguards inspectors and/or other interested parties. The NGSI–SF team is working to achieve the following technical goals more easily and efficiently than in the past using nondestructive assay measurements of spent fuel assemblies: (1) verify the initial enrichment, burnup, and cooling time of facility declaration; (2) detect the diversion or replacement of pins; (3) estimate the plutonium mass [which is also a function of the variables in (1)]; (4) estimate the decay heat; and (5) determine the reactivity of spent fuel assemblies. Since August 2013, a set of measurement campaigns has been conducted at the Central Interim Storage Facility for Spent Nuclear Fuel (Clab), in collaboration with Swedish Nuclear Fuel and Waste Management Company (SKB). One purpose of the measurement campaigns was to acquire passive gamma spectra with high-purity germanium and lanthanum bromide scintillation detectors from Pressurized Water Reactor and Boiling Water Reactor spent fuel assemblies. The absolute {sup 137}Cs count rate and the {sup 154}Eu/{sup 137}Cs, {sup 134}Cs/{sup 137}Cs, {sup 106}Ru/{sup 137}Cs, and {sup 144}Ce/{sup 137}Cs isotopic ratios were extracted; these values were used to construct corresponding model functions (which describe each measured quantity’s behavior over various combinations of burnup, cooling time, and initial enrichment) and then were used to determine those same quantities in each measured spent fuel assembly. The results obtained in comparison with the operator declared values, as well as the methodology developed, are discussed in detail in the paper.

  1. Coal Combustion Products Extension Program

    Energy Technology Data Exchange (ETDEWEB)

    Tarunjit S. Butalia; William E. Wolfe

    2006-01-11

    This final project report presents the activities and accomplishments of the ''Coal Combustion Products Extension Program'' conducted at The Ohio State University from August 1, 2000 to June 30, 2005 to advance the beneficial uses of coal combustion products (CCPs) in highway and construction, mine reclamation, agricultural, and manufacturing sectors. The objective of this technology transfer/research program at The Ohio State University was to promote the increased use of Ohio CCPs (fly ash, FGD material, bottom ash, and boiler slag) in applications that are technically sound, environmentally benign, and commercially competitive. The project objective was accomplished by housing the CCP Extension Program within The Ohio State University College of Engineering with support from the university Extension Service and The Ohio State University Research Foundation. Dr. Tarunjit S. Butalia, an internationally reputed CCP expert and registered professional engineer, was the program coordinator. The program coordinator acted as liaison among CCP stakeholders in the state, produced information sheets, provided expertise in the field to those who desired it, sponsored and co-sponsored seminars, meetings, and speaking at these events, and generally worked to promote knowledge about the productive and proper application of CCPs as useful raw materials. The major accomplishments of the program were: (1) Increase in FGD material utilization rate from 8% in 1997 to more than 20% in 2005, and an increase in overall CCP utilization rate of 21% in 1997 to just under 30% in 2005 for the State of Ohio. (2) Recognition as a ''voice of trust'' among Ohio and national CCP stakeholders (particularly regulatory agencies). (3) Establishment of a national and international reputation, especially for the use of FGD materials and fly ash in construction applications. It is recommended that to increase Ohio's CCP utilization rate from 30% in 2005 to

  2. EXTENSION OPERATOR AND NEURON NETWORK

    OpenAIRE

    LUIZ CARLOS C PEDROZA

    1997-01-01

    Na tese se desenvolve a teoria do Operador de extensão (OPEX) e utiliza-se desta para compreender melhor algumas questões relativas a teoria de Redes Neurais(RN). A abordagem de Redes Neurais pela ótica do Operador de Extensão possibilita também um melhoramento no algoritmo de retropropagação de erro usado no treinamento supervisionado das Redes Neurais. In this thesis, theory of Extension Operator is developed and used to understand some questions related to ...

  3. Combined Dietotherapy after Extensive Hepatectomies

    Directory of Open Access Journals (Sweden)

    V. V. Kiselev

    2007-01-01

    Full Text Available Objective: to compare the time course of nutritional changes in relation to the components of nutritive support in the early postoperative period after extensive hepatectomies.Subjects and methods. Beginning with the 1st postoperative day, 12 patients had parenteral feeding comprising 20% glucose, fat emulsions, and specialized amino acid solutions (Group 1. Beginning with the same day, 14 patients were given the parenteral formula Oliclinomel (Group 2. Starting from the 2nd postoperative day, both groups additionally received a balanced feeding formula by sipping.Results. Postoperatively, first-to-second degree encephalopathy was recorded in both groups. Positive changes as consciousness recovery were found in both Group 1 in which the patients used branched-chain amino acid-enriched solutions and Group 2 (parenteral Oliclinomel feeding. The patients under examination were not given albumin solutions and fresh frozen plasma in the postoperative period. Moreover, by postoperative day 7, there were significant increases in the levels of albumin and total protein in Groups 1 and 2, in those of cholinesterase and the absolute count of lymphocytes, and a reduction in the concentration of C-reactive protein.Conclusion. Combined parenteral and enteral feedings are effective in patients after extensive hepatectomies. The parenteral feeding formula Oliclinomel may be used in this group of patients. 

  4. An Expressive Extension of TLC

    DEFF Research Database (Denmark)

    Henriksen, Jesper Gulmann

    2002-01-01

    A temporal logic of causality (TLC) was introduced by Alur, Penczek and Peled in [1]. It is basically a linear time temporal logic interpreted over Mazurkiewicz traces which allows quantification over causal chains. Through this device one can directly formulate causality properties of distributed...... systems. In this paper we consider an extension of TLC by strengthening the chain quantification operators. We show that our logic TLC* adds to the expressive power of TLC. We do so by defining an Ehrenfeucht-Fraïssé game to capture the expressive power of TLC. We then exhibit a property and by means...... of this game prove that the chosen property is not definable in TLC. We then show that the same property is definable in TLC*. We prove in fact the stronger result that TLC* is expressively stronger than TLC exactly when the dependency relation associated with the underlying trace alphabet is not transitive....

  5. Fluorescein-related extensive jaundice.

    Science.gov (United States)

    Kalkan, Asim; Turedi, Suleyman; Aydin, Ibrahim

    2015-03-01

    Fluorescein is a chemical dye frequently used in eye diseases to assess blood flow in the retina, choroid tissue, and iris. Although it has many known adverse effects, it has not previously been reported to lead to jaundice. The purpose of this case report was to emphasize that for patients presenting at the emergency department with jaundice symptoms, it should not be forgotten by emergency physicians that jaundice can develop after fluorescein angiography. Case: A 65-year-old woman presented at the emergency department with extensive jaundice that had developed on her entire body a few hours after fluorescein angiography applied because of vision impairment. The test results for all the diseases considered to cause jaundice were normal,and fluorescein-related jaundice was diagnosed. Conclusion: A detailed anamnesis should be taken when jaundice is seen in patients who have undergone fluorescein angiography, and it should not be forgotten that fluorescein dye is a rare cause of jaundice.

  6. Competency Modeling in Extension Education: Integrating an Academic Extension Education Model with an Extension Human Resource Management Model

    Science.gov (United States)

    Scheer, Scott D.; Cochran, Graham R.; Harder, Amy; Place, Nick T.

    2011-01-01

    The purpose of this study was to compare and contrast an academic extension education model with an Extension human resource management model. The academic model of 19 competencies was similar across the 22 competencies of the Extension human resource management model. There were seven unique competencies for the human resource management model.…

  7. Extension contact and professional competencies needed by ...

    African Journals Online (AJOL)

    Extension contact and professional competencies needed by extension agents in the Central Region of Ghana for effective transfer of fish-processing technologies to small-scale women in fish processing - Provisional Communication.

  8. 7 CFR 15b.27 - Extension education.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 1 2010-01-01 2010-01-01 false Extension education. 15b.27 Section 15b.27 Agriculture... Education § 15b.27 Extension education. (a) General. A recipient to which this subpart applies that provides extension education may not, on the basis of handicap, exclude qualified handicapped persons. A recipient...

  9. Improving the Extension Facilities in C+

    Energy Technology Data Exchange (ETDEWEB)

    Dubois, P F; Scott, B A

    1999-09-24

    CXX is a facility for extending Python using C++. Recently, the authors have substantially revised and improved the way in which you create extension objects and extension modules in C++. The method is now much more natural and has much less overhead, both in the code generated and in the effort needed to create the objects and extensions.

  10. Effectiveness Of Communication Outreach Strategies Of Extension ...

    African Journals Online (AJOL)

    Communication is a major component of agricultural extension and extension agents utilize various methods to deliver messages to their clienteles. The paper focused on the effectiveness of communication outreach strategies of extension agents in Imo State, Nigeria. Data for the study was collected with the aid of ...

  11. Agricultural Extension training needs of the Nongovernment ...

    African Journals Online (AJOL)

    Extension practitioners from the private sector are highly trained in the Natural Science. Some shortfalls in their Extension Science training have been identified. Perceived training needs in the Extension Science within this sector have been privatised. A number of possible training inputs and options are suggested. Options ...

  12. Extensive Reading and the Effect of Shadowing

    Science.gov (United States)

    Nakanishi, Takayuki; Ueda, Atsuko

    2011-01-01

    The aim of this study is to investigate the effects of extensive reading (ER) and shadowing on performance on reading comprehension tests. This study addressed the following research questions: (a) Can extensive reading improve students' reading comprehension? and (b) can shadowing enhance the effects of extensive reading? The participants in the…

  13. Rural Extension Services. Policy Research Working Paper.

    Science.gov (United States)

    Anderson, Jock R.; Feder, Gershon

    This paper analyzes the considerations that lead policy makers to undertake extension investments as a key public responsibility, as well as the complex set of factors and intra-agency incentives that explain variations in performance between different extension systems. The goals of extension include transferring knowledge from researchers to…

  14. Logic regression and its extensions.

    Science.gov (United States)

    Schwender, Holger; Ruczinski, Ingo

    2010-01-01

    Logic regression is an adaptive classification and regression procedure, initially developed to reveal interacting single nucleotide polymorphisms (SNPs) in genetic association studies. In general, this approach can be used in any setting with binary predictors, when the interaction of these covariates is of primary interest. Logic regression searches for Boolean (logic) combinations of binary variables that best explain the variability in the outcome variable, and thus, reveals variables and interactions that are associated with the response and/or have predictive capabilities. The logic expressions are embedded in a generalized linear regression framework, and thus, logic regression can handle a variety of outcome types, such as binary responses in case-control studies, numeric responses, and time-to-event data. In this chapter, we provide an introduction to the logic regression methodology, list some applications in public health and medicine, and summarize some of the direct extensions and modifications of logic regression that have been proposed in the literature. Copyright © 2010 Elsevier Inc. All rights reserved.

  15. Extensions of cutting problems: setups

    Directory of Open Access Journals (Sweden)

    Sebastian Henn

    2013-08-01

    Full Text Available Even though the body of literature in the area of cutting and packing is growing rapidly, research seems to focus on standard problems in the first place, while practical aspects are less frequently dealt with. This is particularly true for setup processes which arise in industrial cutting processes whenever a new cutting pattern is started (i.e. a pattern is different from its predecessor and the cutting equipment has to be prepared in order to meet the technological requirements of the new pattern. Setups involve the consumption of resources and the loss of production time capacity. Therefore, consequences of this kind must explicitly be taken into account for the planning and control of industrial cutting processes. This results in extensions to traditional models which will be reviewed here. We show how setups can be represented in such models, and we report on the algorithms which have been suggested for the determination of solutions of the respective models. We discuss the value of these approaches and finally point out potential directions of future research.

  16. [Extensively drug-resistant tuberculosis].

    Science.gov (United States)

    Lange, C; Grobusch, M P; Wagner, D

    2008-02-01

    Recently an increasing number of antibiotic-resistant MYCOBACTERIUM TUBERCULOSIS (MTB) strains have been described worldwide. The term XDR- (extensively drug-resistant) tuberculosis (TB) has been introduced by the World Health Organisation (WHO) to characterize multi-drug-resistant MTB strains that are in vitro resistant against fluorochinolones and one of the injectible substances amikacin, capreomycin or kanamycin in addition to isoniazid and rifampin. Strains of XDR-MTB are currently increasingly seen in HIV-seropositive individuals with tuberculosis in southern Africa, where these strains are passed by person-to person contact. XDR-TB has become a serious problem for the health administrations in this region. In contrast, cases of XDR-TB are only rarely seen in Germany so far, mainly among the population of pre-treated migrants from eastern Europe. The development of rapid diagnostic tests for resistance testing and new drugs for the treatment of tuberculosis has lacked support for several decades. The sudden emergence of XDR-MTB strains now warrants immediate action for the development of such tests and new classes of antibiotics to give all patients with TB a chance for a successful treatment.

  17. XPL the Extensible Presentation Language

    Directory of Open Access Journals (Sweden)

    A. Santangelo

    2009-01-01

    Full Text Available The last decade has witnessed a growing interest in the development of web interfaces enabling both multiple ways to access contents and, at the same time, fruition by multiple modalities of interaction (point-and-click, contents reading, voice commands, gestures, etc.. In this paper we describe a framework aimed at streamlining the design process of multi-channel, multimodal interfaces enabling full reuse of software components. This framework is called the eXtensible Presentation architecture and Language (XPL, a presentation language based on design pattern paradigm that keeps separated the presentation layer from the underlying programming logic. The language supplies a methodology to expedite multimodal interface development and to reduce the effort to implement interfaces for multiple access devices, by means of using the same code. This paper describes a methodology approach based on Visual Design Pattern (ViDP and Verbal Design Pattern (VeDP, offering examples of multimodal and multichannel interfaces created with the XPL Editor.

  18. Extension of platelet concentrate storage.

    Science.gov (United States)

    Simon, T L; Nelson, E J; Carmen, R; Murphy, S

    1983-01-01

    Extension of the storage time of platelet concentrates in a satellite bag which is part of a new blood bag system was studied by reinfusing autologous 51Cr-labeled platelets into normal volunteers, and measuring postinfusion platelet counts and bleeding times in patients requiring platelet transfusions. This satellite bag, made of polyvinylchloride plasticized with a new agent, was found to protect platelet concentrates against fall of pH better than other containers studied. This protection was felt to be due to the greater gas permeability of the new plastic. Mean in vivo recovery and half-life (greater than 31% and 3.3 days, respectively) of autologous reinfused platelets were satisfactory following 5 days of storage. Following 7 days of storage, mean recovery was 41 percent and half-life was 2.8 days. Peripheral platelet count increments in patients following platelet transfusions with concentrates stored 4 to 7 days in the new plastic were comparable to increments following transfusion of platelets stored 2 to 3 days in the other plastics studied. Bleeding times shortened in three of four patients receiving platelet concentrates stored from 4 to 6 days in the new plastic. Platelet concentrates stored in the new bag at 20 to 24 degrees C with flat-bed or elliptical agitation could be transfused for up to 5 days following phlebotomy with acceptable clinical results. The new plastic container is promising for storage of platelet concentrates for up to 7 days. Due to the higher pH of 50-ml platelet concentrates stored in bags made with the new plastic, the concentrates were superior at any storage interval to those stored in bags made of the other plastics studied.

  19. Extension systems in Southern African countries: A review | Oladele ...

    African Journals Online (AJOL)

    Global Approaches to Extension Practice: A Journal of Agricultural Extension ... programmes to improve rural areas, extensive grassroots coverage, use of ICT, high involvement of farmers in extension planning, potential for effective programme implementation, and effective setting of extension administration units.

  20. Extension of Mittag-Leffler function

    OpenAIRE

    Rahman, G.; K.S. Nisar; Mubeen, S; Arshad, M.

    2017-01-01

    In this paper, we present an extension of Mittag-Leffler function by using the extension of beta functions (\\"{O}zergin et al. in J. Comput. Appl. Math. 235 (2011), 4601-4610) and obtain some integral representation of this newly defined function. Also, we present the Mellin transform of this function in terms of Wright hypergeometric function. Furthermore, we show that the extended fractional derivative of the usual Mittag-Leffler function gives the extension of Mittag-Leffler function.

  1. Towards professionalism in agricultural extension: The professional ...

    African Journals Online (AJOL)

    Towards professionalism in agricultural extension: The professional registration of Extensionists in South Africa – A dream or a reality? The role of the South African Society of Extensionists in South Africa – A dream or a reality? The role of the South African Society of Agricultural Extension (SASAE)

  2. Effective Use of Facebook for Extension Professionals

    Science.gov (United States)

    Mains, Mark; Jenkins-Howard, Brooke; Stephenson, Laura

    2013-01-01

    As the use of social media increases, Extension is challenged to stay relevant with cliental by using digital tools. This article illustrates how Facebook can be part of Extension's repertoire of methods for communication, program implementation, education, and marketing. This allows professionals to build social networking capacity with…

  3. Job satisfaction of extension agents towards innovation ...

    African Journals Online (AJOL)

    The study assessed job satisfaction of extension agents towards innovation dissemination to fish farmers in Lagos State, Nigeria. A simple random sampling technique was used to select 44 extension officers from which data were collected. A structured questionnaire consisting of 6 personal characteristics, 23 management ...

  4. Plagiarism within Extension: Origin and Current Effects

    Science.gov (United States)

    Rollins, Dora

    2011-01-01

    Extension publication editors from around the United States are finding cases of plagiarism within manuscripts that Extension educators submit as new public education materials. When editors confront such educators with the problem, some don't understand it as such, rationalizing that reproducing published information for a new purpose qualifies…

  5. Extension Sustainability Camp: Design, Implementation, and Evaluation

    Science.gov (United States)

    Brain, Roslynn; Upton, Sally; Tingey, Brett

    2015-01-01

    Sustainability Camps provide an opportunity for Extension educators to be in the forefront of sustainability outreach and to meet the growing demand for sustainability education. This article shares development, implementation, and evaluation of an Extension Sustainability Camp for youth, grades 4-6. Camp impact was measured via daily pre-and…

  6. Sound Type-Dependent Syntactic Language Extension

    NARCIS (Netherlands)

    Lorenzen, Florian; Erdweg, S.T.

    2016-01-01

    Syntactic language extensions can introduce new facilities into a programming language while requiring little implementation effort and modest changes to the compiler. It is typical to desugar language extensions in a distinguished compiler phase after parsing or type checking, not affecting any of

  7. Implementing socially responsive forestry extension programmes ...

    African Journals Online (AJOL)

    Following a literature review which pays particular attention to southern African references, a socially responsive forestry extension model is outlined. It is contended that the initial establishment of sustainable extension programmes rest upon the nature of the relations between the central-level office, the extensionist and ...

  8. Agricultural extension officers' perceptions of integrated pest ...

    African Journals Online (AJOL)

    The extension officers further believed that IPM has the potential to contribute effectively in pest management by the majority of small scale farmers in Kenya. The extension officers viewed crop rotation, a cultural practice, to be of priority use in pest management. Most of the other IPM practices were considered practical in ...

  9. Communication for Strengthening Agricultural Extension and Rural ...

    African Journals Online (AJOL)

    chrischisoni

    communication theories, methods, technologies and strategies. Yet they feel inadequately trained in these areas. Extension workers' views on decentralization. The government's policies on decentralization and pluralistic and demand-driven extension were introduced in 2000. This study was conducted almost a decade ...

  10. Farmer Experience of Pluralistic Agricultural Extension, Malawi

    Science.gov (United States)

    Chowa, Clodina; Garforth, Chris; Cardey, Sarah

    2013-01-01

    Purpose: Malawi's current extension policy supports pluralism and advocates responsiveness to farmer demand. We investigate whether smallholder farmers' experience supports the assumption that access to multiple service providers leads to extension and advisory services that respond to the needs of farmers. Design/methodology/approach: Within a…

  11. Subintegrality, invertible modules and Laurent polynomial extensions

    Indian Academy of Sciences (India)

    Let ⊆ be a commutative ring extension. Let I(, ) be the multiplicative group of invertible -submodules of . In this article, we extend a result of Sadhu and Singh by finding a necessary and sufficient condition on an integral birational extension ⊆ of integral domains with dim ≤ 1, so that the natural map I(, ...

  12. Perception of Commercialization of Agricultural Extension Service ...

    African Journals Online (AJOL)

    Public extension service delivery system has been unable to satisfactorily respond to the challenges of agricultural development, poverty eradication and rural transformation in Nigeria, resulting in continued calls for alternative systems, including commercialization of extension service. Because of their strategically ...

  13. Agricultural extension, research, and development for increased ...

    African Journals Online (AJOL)

    Analysis of the data collected revealed that the improvement of agricultural production, with the goal of sustainable food security, in South Africa, might not be achieved without an effective agricultural extension service that is strongly linked to research. It was also found that public sector extension work is a necessity for the ...

  14. Extension Learners' Use of Electronic Technology

    Science.gov (United States)

    Guenthner, Joseph F.; Swan, Benjamin G.

    2011-01-01

    Extension clientele use electronic technology for entertainment, communication, and business. Educational programs that use electronic technology can enhance learning. To learn more about use of electronic technology among Extension clientele, we surveyed 80 university students and 135 potato farmers. We found that the farmers were likely to use…

  15. Livestock extension practice and competency among agricultural ...

    African Journals Online (AJOL)

    The challenge of meeting the ever-increasing demand for animal products in Nigeria has become keen over the years. A major factor is low technology input by the bulk of animal producers. Because Extension has a crucial role to play, the purpose of this study was to investigate livestock extension (LE) activities and ...

  16. Job satisfaction amongst agricultural extension personnel in ...

    African Journals Online (AJOL)

    Job satisfaction broadly is considered to be as attitude of a person reflecting the degree to which his/her important needs are satisfied by this job. To study the job satisfaction level and factors associated with job satisfaction of Extension personnel, a sample of 74 extension personnel from Kurdistan province of Iran were ...

  17. Declarative language extensions for Prolog courses

    NARCIS (Netherlands)

    Neumerkel, U.; Triska, M.; Wielemaker, J.

    2008-01-01

    In this paper we present several extensions to support a more declarative view of programming in Prolog. These extensions enable introductory Prolog courses to concentrate on the pure parts of Prolog for longer periods than without. Even quite complex programs can now be written free of any

  18. Extensive Reading in Enhancing Lexical Chunks Acquisition

    Science.gov (United States)

    Pereyra, Nilsa

    2015-01-01

    The purpose of this action research was to investigate the effect of extensive reading and related activities on the acquisition of lexical chunks in EFL students. Seven adult EFL learners with an Intermediate level volunteered to take part in the 16 week project following Extensive Reading principles combined with tasks based on the Lexical…

  19. Extensive Reading Materials Produced by Learning Communities

    Science.gov (United States)

    Jacobs, G. M.

    2013-01-01

    This article advocates that students and teachers create some of their own extensive reading materials. Learning communities act as a means of motivating and sustaining student and teacher production of extensive reading materials. The article begins by explaining learning communities. The bulk of the article has two parts. The first part focuses…

  20. Extensive Reading: Students' Performance and Perception

    Science.gov (United States)

    Fernandez de Morgado, Nelly

    2009-01-01

    Reading is thought to be a crucial skill in the EFL learning process, and Extensive Reading a very useful strategy. However, very few teachers implement it on a regular basis. The process of introducing Extensive Reading (ER) is considered far too expensive, complicated, and time-consuming. One way to encourage its use would be to more deeply…

  1. Creating Teams Increases Extension Educator Productivity

    Science.gov (United States)

    Chalker-Scott, Linda; Daniels, Catherine H.; Martini, Nicole

    2016-01-01

    The Garden Team at Washington State University is a transdisciplinary group of faculty, staff, and students with expertise in applied plant and soil sciences and an interest in Extension education. The team's primary mission is to create current, relevant, and peer-reviewed materials as Extension publications for home gardeners. The average yearly…

  2. 77 FR 16022 - Agency Information Collection Extension

    Science.gov (United States)

    2012-03-19

    ... 1995. The information collection requests a three-year extension of its Better Buildings, Better Plants... and Regulatory Affairs, Office of Management and Budget, New Executive Office Building, Room 10102... of Energy Efficiency and Renewable Energy Agency Information Collection Extension AGENCY: Office of...

  3. User contributions and public extension delivery modes ...

    African Journals Online (AJOL)

    This study examined a number of extension communication channels through which farmers received farm management services/information from the public extension agent. The idea was, first, to find out the dominant channel(s) through which information/services were received and, second, to assess the willingness of ...

  4. Bilateral Wilms Tumor With Ureteral Extension.

    Science.gov (United States)

    Lockwood, Gina; Ferrer, Fernando; Makari, John

    2017-04-01

    Wilms tumor is the most common renal tumor in children. However, tumor extension into the ureter is exceedingly rare. We present a case of bilateral Wilms tumor with unilateral ureteral extension into the bladder. This case illustrates the importance of thoughtful diagnostic evaluation and surgical planning to obtain a good oncologic outcome while preserving renal function. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. assessment of extension agents' communication methods

    African Journals Online (AJOL)

    USER

    ABSTRACT. The need to improve aquaculture production through enhanced technology transfer necessitated this study to assess extension agents' use of communication methods and its impact on linkage. A structured questionnaire was administered to 44 extension agents who were randomly selected from Lagos State ...

  6. Revitalizing Agricultural Extension Curriculum for Effective ...

    African Journals Online (AJOL)

    The authors argue that African agricultural universities and colleges must strengthen their capacities to develop and deliver responsive extension training programs in order to train extension staff to become critical thinkers and reflective practitioners. A framework is proposed to guide universities and colleges interested in ...

  7. Extension Service Delivery Of Agricultural Development ...

    African Journals Online (AJOL)

    The study was conducted to assess the extension service delivery within the Agricultural Development Programmes of Southwest Nigeria after the cessation of the World Bank funding between 1996 and 2013. Primary data were collected from 201 extension agents across 50% of the states in the area of study using ...

  8. Controleum - an independently extensible control system

    DEFF Research Database (Denmark)

    Jensen, Martin Lykke Rytter

    2014-01-01

    challenging kind of system to design for independent extension. This thesis presents two new software technologies that improve the extensibility of control systems: First, the concept of dynamic links is introduced and Decouplink – an implementation of dynamic links for Java - is presented. Dynamic links......While the extensibility of many software systems has been greatly improved during the past two decades, nontrivial control systems remain to be a category of software systems that are remarkably difficult for independent parties to extend. Support for independent extension is the ability...... is introduced, and an implementation is presented. The extensible controller is a component framework designed to automatically resolve conflicts among mutually unaware components in a control system. The solution is based on the idea that independent components implement different kinds of control concerns...

  9. A New Extension Model: The Memorial Middle School Agricultural Extension and Education Center

    Science.gov (United States)

    Skelton, Peter; Seevers, Brenda

    2010-01-01

    The Memorial Middle School Agricultural Extension and Education Center is a new model for Extension. The center applies the Cooperative Extension Service System philosophy and mission to developing public education-based programs. Programming primarily serves middle school students and teachers through agricultural and natural resource science…

  10. Extension Approach for an Effective Fisheries and Aquaculture Extension Service in India

    Science.gov (United States)

    Kumaran, M.; Vimala, D. Deboral; Chandrasekaran, V. S.; Alagappan, M.; Raja, S.

    2012-01-01

    Purpose: Public-funded fisheries extension services have been blamed as poor and responsible for the slow pace of aquaculture development in India. The present investigation aimed to find concrete interventions to streamline the extension service by understanding the research-extension-farmer linkage indirectly in terms of information sources of…

  11. Extension versus Bending for Continuum Robots

    Directory of Open Access Journals (Sweden)

    George Grimes

    2008-11-01

    Full Text Available In this paper, we analyze the capabilities of a novel class of continuous-backbone ("continuum" robots. These robots are inspired by biological "trunks, and tentacles". However, the capabilities of established continuum robot designs, which feature controlled bending but not extension, fall short of those of their biological counterparts. In this paper, we argue that the addition of controlled extension provides dual and complementary functionality, and correspondingly enhanced performance, in continuum robots. We present an interval-based analysis to show how the inclusion of controllable extension significantly enhances the workspace and capabilities of continuum robots.

  12. abc: An Extensible AspectJ Compiler

    DEFF Research Database (Denmark)

    Avgustinov, Pavel; Christensen, Aske Simon; Hendren, Laurie J.

    2006-01-01

    checking and code generation, as well as data flow and control flow analyses. The AspectBench Compiler (abc) is an implementation of such a workbench. The base version of abc implements the full AspectJ language. Its front end is built using the Polyglot framework, as a modular extension of the Java...... overview of how to use abc to implement an extension. We illustrate the extension mechanisms of abc through a number of small, but nontrivial, examples. We then proceed to contrast the design goals of abc with those of the original AspectJ compiler, and how these different goals have led to different...

  13. Generalized extensions and blocking factors for FITS

    Science.gov (United States)

    Grosbol, P.; Harten, R. H.; Greisen, E. W.; Wells, D. C.

    1988-06-01

    A general design for extending the Flexible Image Transport System (FITS) tape format is proposed. The present design is shown to preserve compatibility with existing FITS tapes and software (including the 'random groups'), while being general enough to permit a wide variety of new extension files to be designed in the future. Rules are given for the blocking of FITS logical records. The rules for the generalized extension of FITS ensure that extensions can be located and decoded by standard routines without interfering with each other.

  14. 77 FR 58364 - Agency Information Collection Extension

    Science.gov (United States)

    2012-09-20

    ... Information Administration Agency Information Collection Extension AGENCY: Energy Information Administration... sent to Colleen Blessing, EI-40, Energy Information Administration, Department of Energy, 1000.... Both quantitative and qualitative studies are developed by EIA. Quantitative studies classify and count...

  15. Veld management: a challenge to agricultural extension ...

    African Journals Online (AJOL)

    Keywords: Adaptive research; Agricultural extension; agriculture; communication; Farmers; Knowledge diffusion; Knowledge generation; management; National Grazing Strategy; On-farm adaptive research; research; south africa; strategies; technology; Veld management. Journal of the Grassland Society of Southern Africa.

  16. Youth Development Agents' Needs: Challenges for Extension ...

    African Journals Online (AJOL)

    ... the areas of competencies. Regular training was therefore recommended for youth development agents to enable them update, improve and learn new strategies in the application of their competencies for extension service delivery. Keywords: Youth, Development, Agents' needs, Volunteer management, Competencies.

  17. Offshore extension of Gomati river, Dwarka

    Digital Repository Service at National Institute of Oceanography (India)

    Vora, K.H.; Naik, D.K.; Ganesan, P.; Moraes, C.

    information. Attempts have been made to identify the submerged extension of Gomati River by diving inspection and based on the results obtained such as findings like stone and iron anchors, circular bastions, etc. While many features reported earlier...

  18. ERP extension - Supply Chain Management (SCM

    Directory of Open Access Journals (Sweden)

    Vasile LUPSE

    2006-01-01

    Full Text Available This article presents an extension of a ERP (Enterprise Resource Planning, more precisely the Supply Chain Management (SCM, together with some personal considerations and contributions of the authors, regarding the presented concepts.

  19. Integrated Composite Rocket Nozzle Extension Project

    Data.gov (United States)

    National Aeronautics and Space Administration — ORBITEC proposes to develop and demonstrate an Integrated Composite Rocket Nozzle Extension (ICRNE) for use in rocket thrust chambers. The ICRNE will utilize an...

  20. 78 FR 13333 - Agency Information Collection Extension

    Science.gov (United States)

    2013-02-27

    ... energy resource reserves, production, demand, technology, and related economic and statistical... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY U.S. Energy Information Administration Agency Information Collection Extension AGENCY: U.S. Energy Information...

  1. Bandwidth extension of speech using perceptual criteria

    CERN Document Server

    Berisha, Visar; Liss, Julie

    2013-01-01

    Bandwidth extension of speech is used in the International Telecommunication Union G.729.1 standard in which the narrowband bitstream is combined with quantized high-band parameters. Although this system produces high-quality wideband speech, the additional bits used to represent the high band can be further reduced. In addition to the algorithm used in the G.729.1 standard, bandwidth extension methods based on spectrum prediction have also been proposed. Although these algorithms do not require additional bits, they perform poorly when the correlation between the low and the high band is weak. In this book, two wideband speech coding algorithms that rely on bandwidth extension are developed. The algorithms operate as wrappers around existing narrowband compression schemes. More specifically, in these algorithms, the low band is encoded using an existing toll-quality narrowband system, whereas the high band is generated using the proposed extension techniques. The first method relies only on transmitted high-...

  2. 77 FR 46750 - Agency Information Collection Extension

    Science.gov (United States)

    2012-08-06

    ... information collection, EIA-882T, ``Generic Clearance for Questionnaire Testing, Evaluation, and Research...: Generic Clearance for Questionnaire Testing, Evaluation, and Research; (3) Type of Request: Extension... questionnaires and validate EIA survey forms data quality, including conducting pretest ] surveys, pilot surveys...

  3. Generalized module extension Banach algebras: Derivations and ...

    African Journals Online (AJOL)

    Let A and X be Banach algebras and let X be an algebraic Banach A-module. Then the ℓ-1direct sum A x X equipped with the multiplication (a; x)(b; y) = (ab; ay + xb + xy) (a; b ∈ A; x; y ∈ X) is a Banach algebra, denoted by A ⋈ X, which will be called "a generalized module extension Banach algebra". Module extension ...

  4. Cooperative Extension as a Framework for Health Extension: The Michigan State University Model.

    Science.gov (United States)

    Dwyer, Jeffrey W; Contreras, Dawn; Eschbach, Cheryl L; Tiret, Holly; Newkirk, Cathy; Carter, Erin; Cronk, Linda

    2017-10-01

    The Affordable Care Act charged the Agency for Healthcare Research and Quality to create the Primary Care Extension Program, but did not fund this effort. The idea to work through health extension agents to support health care delivery systems was based on the nationally known Cooperative Extension System (CES). Instead of creating new infrastructure in health care, the CES is an ideal vehicle for increasing health-related research and primary care delivery. The CES, a long-standing component of the land-grant university system, features a sustained infrastructure for providing education to communities. The Michigan State University (MSU) Model of Health Extension offers another means of developing a National Primary Care Extension Program that is replicable in part because of the presence of the CES throughout the United States. A partnership between the MSU College of Human Medicine and MSU Extension formed in 2014, emphasizing the promotion and support of human health research. The MSU Model of Health Extension includes the following strategies: building partnerships, preparing MSU Extension educators for participation in research, increasing primary care patient referrals and enrollment in health programs, and exploring innovative funding. Since the formation of the MSU Model of Health Extension, researchers and extension professionals have made 200+ connections, and grants have afforded savings in salary costs. The MSU College of Human Medicine and MSU Extension partnership can serve as a model to promote health partnerships nationwide between CES services within land-grant universities and academic health centers or community-based medical schools.

  5. Initiation of diapirism by regional extension

    Energy Technology Data Exchange (ETDEWEB)

    Jackson, M.P.A.; Vendeville, B.C. (Univ. of Texas, Austin, TX (United States). Bureau of Economic Geology)

    1992-01-01

    Initiation of diapirism is one of the least understood aspects of salt tectonics. Sedimentary differential loading is a favorite explanation, but special conditions such as focused sedimentation are needed to trigger diapirism by differential loading. Compilation of published data from 18 of the world's salt-diapir provinces shows that salt upwelling is consistently linked in time with regional extension, whether thin-skinned or thick-skinned. Extended salt basins typically develop salt structures, whereas nonextended basins typically do not. In some basins containing thick salt (SW Iran), diapirism was delayed as long as 400 Ma until the basin was regionally extended. In other salt provinces (Maritime Alps), episodic growth of salt diapirs correlates with episodic regional extension during opening of the Neo-Tethys and Atlantic Oceans. Once initiated, salt diapirism can continue after regional extension is succeeded by contraction or quiescence. Thus even in salt basins overprinted by inversion or orogenic contraction (Morocco, Lusitania, Basque-Cantabrian, North Sea), the diapirs were initiated during extension on divergent continental margins or in intracontinental rifts. This observed temporal link between extension and diapirism is consistent with physical and numerical modeling, which demonstrates that extensional faulting of the overburden directly causes diapirism whether the salt was deposited before, during, or after rifting. Where the overburden is thinned by extension, pressurized salt wells up in response to the shifting positions of fault blocks.

  6. An Educational Extension Service in India

    Science.gov (United States)

    Krichevsky, M. I.

    2001-12-01

    A strength of US education is interaction with the public under the Land Grant University program. The public benefits from outreach through extension services which evolved for communication with end users, e.g., farmers, homemakers, public health providers, schoolchildren and entrepreneurs i.e., the public with problems and the extension agents who advise on solutions. Further, the agents can seek specialized advice from university faculty. No such system exists in India. The University of Pune (UP), Bionomics International (BI), and WorldSpace Foundation (WSF) will use digital radio broadcasts to facilitate educational extension services. The UP (350,000 students, 250 campuses, among dispersed communities) is a useful institutional setting to demonstrate the value of an outreach system in India. The UP will coordinate development of the broadcast content and the teaching faculty. The campuses will be focal points for outreach. BI will consult on development of the extension structure. WSF will provide the facilities and technical expertise for use of the digital system under the terms of an agreement with Bionomics International. Digital radios (&$slash75-150 each) and PCs will be at each campus and community. The major components of the Extension Service are broadcast of 1) University lecture and examination material in many disciplines; 2) outreach to the general population with of "canned" presentations and talks, skits, songs, games. The steps are: 1) Enhance communication among the campuses by use of satellite digital audio and multimedia broadcasts with feedback by telephone, mail, fax, etc. 2) Develop course material for training of extension personnel. 3) Train extension personnel to interface between the faculty of the University and the local population. 4) Extend digital radio services to population centers for communication of locally useful information. 5) Utilize extension personnel for system maintenance, motivating use of the broadcast

  7. Timeability in Extensive-Form Games

    DEFF Research Database (Denmark)

    Jakobsen, Sune K.; Sørensen, Troels Bjerre; Conitzer, Vincent

    2016-01-01

    Extensive-form games constitute the standard representation scheme for games with a temporal component. But do all extensive-form games correspond to protocols that we can implement in the real world? We often rule out games with imperfect recall, which prescribe that an agent forget something...... that she knew before. In this paper, we show that even some games with perfect recall can be problematic to implement. Specifically, we show that if the agents have a sense of time passing (say, access to a clock), then some extensive-form games can no longer be implemented; no matter how we attempt...... to time the game, some information will leak to the agents that they are not supposed to have. We say such a game is not exactly timeable. We provide easy-to-check necessary and sufficient conditions for a game to be exactly timeable. Most of the technical depth of the paper concerns how to approximately...

  8. Mathematics for common entrance three (extension) answers

    CERN Document Server

    Alexander, Serena

    2015-01-01

    This book contains answers to all exercises featured in the accompanying textbook Mathematics for Common Entrance Three (Extension) , which provides essential preparation for Level 3 of the ISEB 13+ Mathematics exam, as well as for CASE and other scholarship exams. - Clean, clear layout for easy marking. - Includes examples of high-scoring answers with diagrams and workings. Also available to purchase from the Galore Park website www.galorepark.co.uk :. - Mathematics for Common Entrance Three (Extension). - Mathematics for Common Entrance One. - Mathematics for Common Entrance One Answers. - M

  9. Graded junction termination extensions for electronic devices

    Science.gov (United States)

    Merrett, J. Neil (Inventor); Isaacs-Smith, Tamara (Inventor); Sheridan, David C. (Inventor); Williams, John R. (Inventor)

    2007-01-01

    A graded junction termination extension in a silicon carbide (SiC) semiconductor device and method of its fabrication using ion implementation techniques is provided for high power devices. The properties of silicon carbide (SiC) make this wide band gap semiconductor a promising material for high power devices. This potential is demonstrated in various devices such as p-n diodes, Schottky diodes, bipolar junction transistors, thyristors, etc. These devices require adequate and affordable termination techniques to reduce leakage current and increase breakdown voltage in order to maximize power handling capabilities. The graded junction termination extension disclosed is effective, self-aligned, and simplifies the implementation process.

  10. Extensive keloidal healing of pemphigus vulgaris

    Directory of Open Access Journals (Sweden)

    Khanna Neena

    1997-01-01

    Full Text Available Bullae of pemphigus vulgaris heal without scarring. We here report a patient of pemphigus vulgaris whose lesions healed with a one-month history of extensive flaccid bullae and uninfected erosions on the trunk and extremities along with superficial erosions in the oral mucosa. The clinical suspicion of pemphigus vulgaris was confirmed by histopathological and immunohistological examination. Pulse therapy with monthly parenteral dexamethasone and cyclophosphamide pulse was instituted. The cutaneous lesions on healing formed extensive keloidal scars despite high dose of monthly corticosteroid therapy.

  11. Switchings, extensions, and reductions in central digraphs

    DEFF Research Database (Denmark)

    Kündgen, André; Leander, Gregor; Thomassen, Carsten

    2011-01-01

    A directed graph is called central if its adjacency matrix A satisfies the equation A2=J, where J is the matrix with a 1 in each entry. It has been conjectured that every central directed graph can be obtained from a standard example by a sequence of simple operations called switchings, and also ...... that it can be obtained from a smaller one by an extension. We disprove these conjectures and present a general extension result which, in particular, shows that each counterexample extends to an infinite family....

  12. Algomaster Platform Extension for Improved Usability

    Directory of Open Access Journals (Sweden)

    BENEJ Martin

    2017-05-01

    Full Text Available Visualizations of algorithms and data structures can be effectively used for supporting the teaching process. However, such visualization must be comprehensive for students and still semantically correct. Algomaster visualization platform offers effective visualization and simple extensibility. In this paper we describe major platform extensions we have implemented, including support for visualization of complex algorithms, features for real-time student testing and the tool for simplified development of new Algomaster plugins. These complex algorithms comprise visualization of operations with self-balancing trees and hashing algorithm. To enable the real-time student testing we have created a database and a separate tool for its management.

  13. Non-destructive determination of the burn-up of a nuclear fuel using {gamma} spectrometry; Determination non destructive du taux de combustion d'un combustible nucleaire par spectrometrie {gamma}

    Energy Technology Data Exchange (ETDEWEB)

    Engelman, Ch.; Petit, J.F. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-07-01

    A non-destructive method has been developed for measuring the burn-up of a nuclear fuel. The principle of the method is based on the quantitative determination of a fission product using {gamma} spectrometry. For fuel elements containing uranium 235, the measurements concern the photoelectric peak at 2.18 MeV of {sup 144}Ce which has a half-life of 290 days. The same method could be applied under certain conditions: a) to the measurement of the number of fissions due to {sup 239}Pu, by dosing the {sup 106}Rh deriving from the {sup 106}Ru and having a half-life of 370 days. b) and therefore possibly to the non-destructive determination of the quantity of {sup 239}Pu present in a fuel element. If the operational programme of the reactor is known as a function of time, the possible field of application of the method is extended to times of irradiation of from two to three years. (authors) [French] Nous avons mis au point une methode de mesure non destructive du taux de combustion d'un combustible nucleaire. Son principe repose sur la determination quantitative d'un produit de fission par spectrometrie {gamma}. Pour les elements combustibles utilisant l'uranium 235, les mesures portent sur le pic photoelectrique a 2,18 MeV du {sup 144}Pr fils du {sup 144}Ce de periode 290 jours. La meme methode pourrait etre appliquee sous certaines conditions : a) a la mesure du nombre de fissions dues au {sup 239}Pu en faisant le dosage du {sup 106}Rh fils du {sup 106}Ru de periode 370 jours. b) donc eventuellement a la determination non destructive de la quantite du {sup 239}Pu contenue dans un element combustible. Si le programme de fonctionnement dans le temps du reacteur est connu, le domaine d'application de la methode s'etend a des durees d'irradiation pouvant atteindre deux a trois ans. (auteurs)

  14. Confidence of Extension Staff in Akwa Ibom State Agricultural ...

    African Journals Online (AJOL)

    the extension agents (EAs), block extension agents (BEAs), block extension supervisors (BESs), and zonal extension officers (ZEOs) were sometimes satisfied with AKADEP as their organization. Age, household size, and years of extension experience of EAs were strong indicators of organizational confidence. Age, level of ...

  15. Expanding Agricultural and Rural Extension Roles for Sustainable ...

    African Journals Online (AJOL)

    Expanding Agricultural and Rural Extension Roles for Sustainable Extension Practice in Nigeria. ... The expanded scope could include marketing extension, non-farm rural micro enterprise development, service to farmers' associations, technical extension service and urban extension. These services should be provided at ...

  16. Global Approaches to Extension Practice: A Journal of Agricultural ...

    African Journals Online (AJOL)

    Global Approaches to Extension Practice (GAEP), A publication of the Department of Agricultural Extension, Federal University of Technology, Owerri, Imo State, Nigeria is an international journal which considers articles from all areas of Agricultural Extension: rural sociology, environmental extension, extension ...

  17. Particle Swarm Optimisation with Spatial Particle Extension

    DEFF Research Database (Denmark)

    Krink, Thiemo; Vesterstrøm, Jakob Svaneborg; Riget, Jacques

    2002-01-01

    In this paper, we introduce spatial extension to particles in the PSO model in order to overcome premature convergence in iterative optimisation. The standard PSO and the new model (SEPSO) are compared w.r.t. performance on well-studied benchmark problems. We show that the SEPSO indeed managed...... to keep diversity in the search space and yielded superior results....

  18. Longest Common Extensions in Sublinear Space

    DEFF Research Database (Denmark)

    Bille, Philip; Gørtz, Inge Li; Knudsen, Mathias Bæk Tejs

    2015-01-01

    The longest common extension problem (LCE problem) is to construct a data structure for an input string T of length n that supports LCE(i,j) queries. Such a query returns the length of the longest common prefix of the suffixes starting at positions i and j in T. This classic problem has a well...

  19. ANTLR Tree Grammar Generator and Extensions

    Science.gov (United States)

    Craymer, Loring

    2005-01-01

    A computer program implements two extensions of ANTLR (Another Tool for Language Recognition), which is a set of software tools for translating source codes between different computing languages. ANTLR supports predicated- LL(k) lexer and parser grammars, a notation for annotating parser grammars to direct tree construction, and predicated tree grammars. [ LL(k) signifies left-right, leftmost derivation with k tokens of look-ahead, referring to certain characteristics of a grammar.] One of the extensions is a syntax for tree transformations. The other extension is the generation of tree grammars from annotated parser or input tree grammars. These extensions can simplify the process of generating source-to-source language translators and they make possible an approach, called "polyphase parsing," to translation between computing languages. The typical approach to translator development is to identify high-level semantic constructs such as "expressions," "declarations," and "definitions" as fundamental building blocks in the grammar specification used for language recognition. The polyphase approach is to lump ambiguous syntactic constructs during parsing and then disambiguate the alternatives in subsequent tree transformation passes. Polyphase parsing is believed to be useful for generating efficient recognizers for C++ and other languages that, like C++, have significant ambiguities.

  20. Communication for Rural Innovation : rethinking agricultural extension

    NARCIS (Netherlands)

    Leeuwis, C.; Ban, van den A.W.

    2004-01-01

    This important book is the re-titled third edition of the extremely well received and widely used Agricultural Extension (van den Ban & Hawkins, 1988, 1996). Building on the previous editions, Communication for Rural Innovation maintains and adapts the insights and conceptual models of value

  1. Banana Algebra: Compositional Syntactic Language Extension

    DEFF Research Database (Denmark)

    Andersen, Jacob; Brabrand, Claus; Christiansen, David Raymond

    2013-01-01

    We propose an algebra of languages and transformations as a means of compositional syntactic language extension. The algebra provides a layer of high-level abstractions built on top of languages (captured by context-free grammars) and transformations (captured by constructive catamorphisms). The ...

  2. Equivalence relations of AF-algebra extensions

    Indian Academy of Sciences (India)

    In this paper, we consider equivalence relations of *-algebra extensions and describe the relationship between the isomorphism equivalence and the unitary equivalence. We also show that a certain group homomorphism is the obstruction for these equivalence relations to be the same.

  3. 78 FR 31885 - Patent Term Extension

    Science.gov (United States)

    2013-05-28

    ... Intellectual Property and Communications Omnibus Reform Act of 1999, require the USPTO to notify the applicant... 1995, Public Law 104-13 (44 U.S.C. 3506(c)(2)(A)). DATES: Written comments must be submitted on or... the extension provisions of 35 U.S.C. 156, the USPTO may in some cases extend the term of an original...

  4. Semi extensive methods - two main systems are

    African Journals Online (AJOL)

    next litter readily within a few days after weaning. It has long been ... terms of early growth and overall efficiency of conversion of ... 21-day Weaning. Semi extensive methods - two main systems are adopted, the first using arks with outside runs on pasture and the second using similar arks but fitted with slatted or weld mesh ...

  5. Seroprevalence Study Of Bovine Brucellosis In Extensive ...

    African Journals Online (AJOL)

    The prevalence of bovine brucellosis was measured in cross sectional study in Jimma zone, Western Ethiopia using Rose Bengal Plate Test (RBT) and CFT from October 2003 to April 2004. The study animals consisted of 1305 local breed found in extensive system in five districts of in the zone. The overall individual animal ...

  6. Stress: Professional Development Needs of Extension Faculty.

    Science.gov (United States)

    Place, Nick T.; Jacob, Steve

    2001-01-01

    Responses from 314 of 422 extension faculty showed a variety of levels of job stress, primarily from time pressures and overcommitment. Those who used formal planning and time management techniques had lower stress scores. Time with family was a common coping mechanism. (Contains 19 references.) (SK)

  7. Tools for Creating Mobile Applications for Extension

    Science.gov (United States)

    Drill, Sabrina L.

    2012-01-01

    Considerations and tools for developing mobile applications for Extension include evaluating the topic, purpose, and audience. Different computing platforms may be used, and apps designed as modified Web pages or implicitly programmed for a particular platform. User privacy is another important consideration, especially for data collection apps.…

  8. South African Journal of Agricultural Extension

    African Journals Online (AJOL)

    The South African Journal of Agricultural Extensionaims to: * advance and apply the science of extension and of rural development as scientific discipline by stimulating thought, study, research, discussion and the publication and exchange of knowledge both nationally and internationally. * promote the professionalism ...

  9. A Graph Library Extension of SVG

    DEFF Research Database (Denmark)

    Nørmark, Kurt

    2007-01-01

    be aggregated as a single node, and an entire graph can be embedded in a single node. In addition, a number of different graph animations are described. The starting point of the SVG extension is a library that provides an exact of mirror of SVG 1.1 in the functional programming language Scheme. Each element...

  10. On Touchard's continued fraction and extensions: combinatorices ...

    African Journals Online (AJOL)

    We give a direct and simple proof of Touchard's continued fraction, provide an extension of it, and transform it into similar expansions related to Motzkin and Schroder numbers. Another proof is then given that uses only induction. We use this machinery on two examples that appear in recent papers of Josuat-Verges; with an ...

  11. Emergency Food Programs: Untapped Opportunities for Extension?

    Science.gov (United States)

    Mobley, Amy R.

    2012-01-01

    This article reports results from a questionnaire that assessed the frequency and type of nutrition questions asked at emergency food programs to determine if Extension professionals need to increase direct outreach efforts. Emergency food program workers (n = 460) were recruited via mail to complete a self-administered survey. More than one-third…

  12. Equivalence relations of AF-algebra extensions

    Indian Academy of Sciences (India)

    Introduction. Brown, Douglas and Fillmore [3] gave the famous BDF theory to study essentially normal operators on an infinite dimensional Hilbert space and extensions of C∗. -algebra C(X) by. K in the 1970's, where X is a compact metric space and K is the C*-algebra of compact operators on an infinite dimensional ...

  13. Measuring Florida Extension Faculty's Agricultural Paradigmatic Preferences

    Science.gov (United States)

    Warner, Laura A.; Murphrey, Theresa Pesl; Lawver, David E.; Baker, Matt; Lindner, James R.

    2014-01-01

    The demand for sustainable agriculture has increased, and many institutions, including the University of Florida, have adopted agricultural sustainability as a major goal. Extension has been identified as a critical information source, important in disseminating sustainable agricultural growing techniques. However, research has demonstrated that…

  14. Assessment Of Shell Petroleum Development Company Extension ...

    African Journals Online (AJOL)

    The study assessed Shell Petroleum Development Company Extension Services in Etche Local Government Area of Rivers State, Nigeria. Data were gathered form four categories of respondents drawn from the Company\\'s staff and the communities. A total of 180 respondents participated in the study. means scores and ...

  15. assessment of shell petroleum development company extension ...

    African Journals Online (AJOL)

    ABSTRACT. The study assessed Shell Petroleum DeVelopment Company Extension. Services in Etche Local Government Area of Rivers State, Nigeria. Data were gathered form four categories of respondents drawn from the. Company's staff and the communities. A total of 180 respondents participated in the study. means ...

  16. Effectively Communicating Science to Extension Audiences

    Science.gov (United States)

    Robinson, Patrick

    2013-01-01

    This article discusses the concept of "framing" within the context of relevant communication and psychological research and considers its potential applicability to Extension science communication. Examples of research-based support for the framing of scientific issues are presented, along with a literature-based discussion of the…

  17. Matching Extension Service With Farmers' Needs: Towards ...

    African Journals Online (AJOL)

    of the farming family and the farm can better target its programs to meet farmers' needs. In this study 305 farm households, from two districts of northcentral Ethiopia are used as a case study, to examine key socio-economic and ecological indicators that affect effective use of extension services. Data was collected using the ...

  18. Improving Generation Y Volunteerism in Extension Programs

    Science.gov (United States)

    Andrews, Kevin B.; Lockett, Landry L.

    2013-01-01

    Members of Generation Y have many positive attributes that make them attractive to Extension volunteer administrators as a potential source of labor. However, they think differently, have unique needs, require new management styles, and have less tolerance for unpleasant working conditions than previous generations. Additionally, they are engaged…

  19. Need for Methamphetamine Programming in Extension Education

    Science.gov (United States)

    Beaudreault, Amy R.; Miller, Larry E.

    2011-01-01

    The study reported sought to identify the prevention education needs involving methamphetamine through survey methodology. The study focused on a random sample of U.S. states and the Extension Directors within each state, resulting in a 70% response rate (n = 134). Findings revealed that 11% reported they had received methamphetamine user…

  20. Integrating Reading and Writing through Extensive Reading

    Science.gov (United States)

    Park, Jeongyeon

    2016-01-01

    This study explores whether an extensive reading (ER) approach can enhance L2 learners' writing performance in an English for Academic Purposes context. Two classes were compared in terms of writing improvement after one semester: a 'traditional' writing class primarily focused on writing practice and grammar instruction, and an ER class in which…

  1. Does Extensive Reading Promote Reading Speed?

    Science.gov (United States)

    He, Mu

    2014-01-01

    Research has shown a wide range of learning benefits accruing from extensive reading. Not only is there improvement in reading, but also in a wide range of language uses and areas of language knowledge. However, few research studies have examined reading speed. The existing literature on reading speed focused on students' reading speed without…

  2. Definable maximal discrete sets in forcing extensions

    DEFF Research Database (Denmark)

    Törnquist, Asger Dag; Schrittesser, David

    2017-01-01

    that in the Sacks and Miller extensions there is a Π11 maximal orthogonal family ("mof") of Borel probability measures on Cantor space. A similar result is also obtained for Π11 mad families. By contrast, we show that if there is a Mathias real over L then there are no Σ12 mofs....

  3. 75 FR 9403 - Agency Information Collection Extension

    Science.gov (United States)

    2010-03-02

    ... Management and Budget (OMB) review; comment request. SUMMARY: The Department of Energy (DOE) has submitted an... 1995. The information collection requests a three-year extension of its Exchange/Sale Report, Excess... and Budget. DATES: Comments regarding this collection must be received on or before April 1, 2010. If...

  4. 78 FR 38305 - Agency Information Collection Extension

    Science.gov (United States)

    2013-06-26

    ... Budget (OMB) review; comment request. SUMMARY: The Department of Energy (DOE) has submitted an... 1995. The information collection requests a three-year extension of its Exchange/Sale Report, Excess... Management and Budget. DATES: Comments regarding this collection must be received on or before July 26, 2013...

  5. Catastrophic failure of polymer melts during extension

    DEFF Research Database (Denmark)

    Rasmussen, Henrik K.

    2013-01-01

    Numerical flow modeling has been applied to study the break of monodisperse polymer melts during extension. These continuum mechanical based computations are within the ideas of the microstructural ’interchain pressure’ theory. Calculated breaks, a result of small initial sample imperfections, ag...

  6. On an extension of a combinatorial identity

    Indian Academy of Sciences (India)

    On an extension of a combinatorial identity. M RANA and A K AGARWAL. Center for Advanced Study in Mathematics, Panjab University, Chandigarh 160 014,. India. E-mail: aka@pu.ac.in. MS received 22 August 2007. Abstract. Using Frobenius partitions we extend the main results of [4]. This leads to an infinite family of ...

  7. Entrepreneurial Extension Conducted via Social Media

    Science.gov (United States)

    Cornelisse, Sarah; Hyde, Jeffrey; Raines, Christopher; Kelley, Kathleen; Ollendyke, Dana; Remcheck, James

    2011-01-01

    The widespread availability of and access to the Internet have led to the development of new forms of communication. Collectively termed "social media," these new communication tools have created vast opportunities for Extension professionals in how they perform their work and how businesses interact with consumers. This article outlines currently…

  8. Newspapers' agricultural agenda setting and extension agents ...

    African Journals Online (AJOL)

    Newspapers content were analyzed from January to June 2002 for agricultural issues raised in them. Data were analyzed using frequencies, percentages, and Spearman rho correlation coefficient. The results revealed that extension agents ranked storage problems as most important (4.24) and investment in agriculture ...

  9. Extension of a theorem due to Ramanujan

    Directory of Open Access Journals (Sweden)

    Medhat A. Rakha

    2014-12-01

    Full Text Available The aim of this research paper is to establish an extension of a theorem due to Ramanujan. The result is obtained with the help of two terminating results for the series $_3F_{2}$ very recently obtained by Rakha et al. A few interesting special cases are also given.

  10. Livestock extension programmes participation and impact on ...

    African Journals Online (AJOL)

    In rural South Africa, the sustainability of cattle-based livelihoods is threatened by the competition for natural resources such as land and water. The central and provincial governments continue to invest funds in agricultural extension in order to uplift the productivity and safeguard the multifunctionality of cattle farming.

  11. Trials and Triumphs of Expanded Extension Programs.

    Science.gov (United States)

    Leavengood, Scott; Love, Bob

    1998-01-01

    Oregon extension faced challenges in presenting programs in the wood products industry. Several traditional tactics, revised to suit a new audience, have proved successful: personal coaching, building partnerships, and providing a high level of service. Newer methods, such as database marketing and distance learning, are also proving to be…

  12. Forestry Extension: An Indispensable Service for Sustainable ...

    African Journals Online (AJOL)

    Unfortunately human activities have depleted the forest through, uncontrolled lumbering, bush burning, charcoal production just to mention a few. ... is the premise on which the challenges facing effective forestry extension delivery in Nigeria and suggested solutions to the highlighted challenges is the focus of this write up.

  13. Rural Development And Agricultural Extension Administration In ...

    African Journals Online (AJOL)

    This paper reviewed the wide range of policies and approaches formulated and implemented to effect agricultural and rural development in Nigeria. The paper reveals that the common feature of all the strategies is the use of institutionalized agricultural extension service, devoted principally to augment smallholder ...

  14. Developing Students' Reading Ability through Extensive Reading

    Science.gov (United States)

    Meng, Fanshao

    2009-01-01

    A good reading competence is a necessity for those studying English for academic and occupational purposes. Based on the results of previous research, theory and practice on L2 Extensive Reading, this paper analyses current situation for teaching and learning reading in our Chinese universities and proposes practical applications of extensive…

  15. Making Extensive Reading Even More Student Centered

    Science.gov (United States)

    Jacobs, George M.; Renandya, Willy A.

    2015-01-01

    This article begins by explaining the student centered learning paradigm. Next, the article explains various features of a student centered approach to education and how extensive reading (ER), as it is most often practiced, fits with those features. The bulk of the article suggests how ER might be implemented to make it even more learner centered.

  16. MAKING EXTENSIVE READING EVEN MORE STUDENT CENTERED

    Directory of Open Access Journals (Sweden)

    George Jacobs

    2015-01-01

    Full Text Available Abstract: This article begins by explaining the student centered learning paradigm.  Next, the article explains various features of a student centered approach to education and how extensive reading (ER, as it is most often practiced, fits with those features.  The bulk of the article suggests how ER might be implemented to make it even more learner centered.

  17. Some extensions and applications of Eisenstein Irreducibility ...

    Indian Academy of Sciences (India)

    Some extensions and applications of Eisenstein Irreducibility. Criterion. Sudesh Kaur Khanduja. Department of ... Suppose that there exists a prime number p such that. • a0 is not divisible by p,. • ai is divisible by p for .... + fn(xn) with complex coefficients is ir- reducible provided the degrees of f1. (x1. ), ..., fn(xn) have greatest ...

  18. Rhinoscleroma with orbital extension: CT and MRI

    Energy Technology Data Exchange (ETDEWEB)

    Le Hir, P. [Department of Radiology, CHU Saint-Antoine, 184 Rue du Faubourg Saint-Antoine, F-75012 Paris (France); Marsot-Dupuch, K. [Department of Radiology, CHU Saint-Antoine, 184 Rue du Faubourg Saint-Antoine, F-75012 Paris (France); Bigel, P. [Department of Pathology, CHU Saint-Antoine, Paris (France); Elbigourmie, T.M. [Department of Radiology, CHU Saint-Antoine, 184 Rue du Faubourg Saint-Antoine, F-75012 Paris (France); Jacquier, I. [ENT Department, CHU Saint-Antoine, Paris (France); Brunereau, L. [Department of Radiology, CHU Saint-Antoine, 184 Rue du Faubourg Saint-Antoine, F-75012 Paris (France); Tubiana, J.M. [Department of Radiology, CHU Saint-Antoine, 184 Rue du Faubourg Saint-Antoine, F-75012 Paris (France)

    1996-02-01

    We describe the MRI features of a rhinoscleroma with orbital extension. This benign bacterial and granulomatous lesion of the paranasal sinuses gave homogeneous low intensity on T2-weighted images and enhanced with gadolinium. It could simulate a malignant sinonasal tumour or a fungal sinusitis; the diagnosis must be considered in patients from endemic areas. (orig.). With 3 figs.

  19. 75 FR 20561 - Patent Term Extension

    Science.gov (United States)

    2010-04-20

    ... Patent and Trademark Office Patent Term Extension ACTION: Proposed collection; comment request. SUMMARY: The United States Patent and Trademark Office (USPTO), as part of its continuing effort to reduce... the Chief Information Officer, United States Patent and Trademark Office, P.O. Box 1450, Alexandria...

  20. Transforming agriculture through contracted extension service ...

    African Journals Online (AJOL)

    Transformation of small holder agriculture from subsistence farming to agribusiness focused systems, is paramount towards attainment of Kenya's vision 2030 and the Millennium Development Goals. This requires extension service delivery systems that focus on addressing challenges within agricultural product value ...

  1. Extensive Actinomyces naeslundii infection in a child.

    OpenAIRE

    Dobson, S R; Edwards, M. S.

    1987-01-01

    A case of extensive Actinomyces naeslundii infection in a globally retarded patient is reported. To our knowledge, this uncommon Actinomyces species has not previously been described as a cause of widespread disease. Mental retardation and thoracic scoliosis were identified as features predisposing to infection.

  2. abc: An extensible AspectJ compiler

    DEFF Research Database (Denmark)

    Avgustinov, Pavel; Christensen, Aske Simon; Hendren, Laurie

    2005-01-01

    checking and code generation, as well as data flow and control flow analyses. The AspectBench Compiler (abc) is an implementation of such a workbench. The base version of abc implements the full AspectJ language. Its frontend is built, using the Polyglot framework, as a modular extension of the Java...

  3. Transmural intrathoracic lipoma with intraspinal extension.

    Science.gov (United States)

    Jain, Vishesh; Singal, Arbinder K; Gupta, Arun K; Bhatnagar, Veereshwar

    2007-12-01

    A rare case of transmural dumbbell intrathoracic lipoma with intraspinal extension is reported. Preoperative diagnosis was possible with a computed tomographic scan and fine-needle aspiration cytology. Complete excision was curative. The chest wall defect was repaired with Prolene mesh. Only one similar case has been previously reported in the English literature.

  4. Professional extension support: A prerequisite for sustainable ...

    African Journals Online (AJOL)

    professionalism and reflects on the general perceptions for professional extension support in irrigation management perceived by small- scale and commercial irrigation farmers. It also portrays the findings on the assessment of the technical competence and knowledge of irrigation extensionists. Possible barriers why ...

  5. An Effective Aquaculture Extension System from Farmers ...

    African Journals Online (AJOL)

    Regionally, government extension system and reading materials also played a significant role in the diffusion of aquaculture information to peri-urban farmers, and were considered to be of high quality and very accessible. This study recommends that the aquaculture division should identify the institutional mechanism ...

  6. Communication for strengthening agricultural extension and rural ...

    African Journals Online (AJOL)

    This paper argues that extension workers need training in Communication for Development (C4D), an emerging body of knowledge for addressing problems, such as participation, integration and capacity building for them to relate more effectively with development partners. Thus, this paper proposes a C4D framework for ...

  7. Extension Procedures for Confirmatory Factor Analysis

    Science.gov (United States)

    Nagy, Gabriel; Brunner, Martin; Lüdtke, Oliver; Greiff, Samuel

    2017-01-01

    We present factor extension procedures for confirmatory factor analysis that provide estimates of the relations of common and unique factors with external variables that do not undergo factor analysis. We present identification strategies that build upon restrictions of the pattern of correlations between unique factors and external variables. The…

  8. Dialogic Reading Aloud to Promote Extensive Reading

    Science.gov (United States)

    Jacobs, George M.

    2016-01-01

    How can teachers motivate students to read extensively in a second language? One strategy is for teachers to read aloud to students to promote the joys of reading generally, to build students' language skills and to introduce students to specific authors, book series, genres, websites, etc. This article begins by discussing why teachers might want…

  9. Testing Extension Services through AKAP Models

    Science.gov (United States)

    De Rosa, Marcello; Bartoli, Luca; La Rocca, Giuseppe

    2014-01-01

    Purpose: The aim of the paper is to analyse the attitude of Italian farms in gaining access to agricultural extension services (AES). Design/methodology/approach: The ways Italian farms use AES are described through the AKAP (Awareness, Knowledge, Adoption, Product) sequence. This article investigated the AKAP sequence by submitting a…

  10. Journal of Environmental Extension: Editorial Policies

    African Journals Online (AJOL)

    Focus and Scope. Journal of Environmental Extension is to be published annually to generate ideas on formulation, packaging, dissemination and consequential impacts of ideas/policies relating to the quality and sustainability of the environment. Focus of the Journal is on: Health Agriculture Technology Waste ...

  11. Women Empowerment And Agricultural Extension Policy: The ...

    African Journals Online (AJOL)

    This paper examined the role and challenges of extension agents in empowering women in a bid to revamp the agricultural sector. The activities of women in agricultural production are reviewed against the backdrop of global shift to gender sensitivity, particularly the emphasis on the role of women in agriculture. The paper ...

  12. Ethics and morals in the extension work

    Directory of Open Access Journals (Sweden)

    Fátima Lourdes Morales Intriago

    2017-05-01

    Full Text Available One of the main discussions about agents that provide rural extension is the lack of adequate proposals for the reality of farmers. The exyensionists work according to ethics and morals. Was carried out a theoretical search by made analyzing concepts about these terms and that are applied by extension agents. In This paper discusses how agents act with respect to the aforementioned notions and the conflicts they can cause with rural communities. It was found that the extensionist’s behavior is based on its values, norms and sanctions formation that can be object, which determines the changes that occur in the communities served. On the other hand, farmers do not receive appropriate attention by organisms that facilitate the Rural Extension, ignoring their interests and priorities. In addition, agents, as servants of institutions that provide assistance and extension, lose autonomy during the contact with communities. It was concluded that agents act correctly according to morality, as well as what concerns to ethics, since lowing the rules of the institution to which they belong, which does not always match with what rural people pursued.

  13. Home Food Preservation Training for Extension Educators

    Science.gov (United States)

    Goard, Linnette Mizer; Hill, Melinda; Shumaker, Katharine; Warrix, Marisa

    2013-01-01

    During times of economic downturn, there has been an increased interest in home food preservation. As the primary resource for current research-based recommendations, a team of Extension Family and Consumer Sciences educators with specialization in food safety and food preservation responded to this demand by developing a standardized food…

  14. FISHERIES EXTENSION SERVICES IN OGUN STATE | Olopade ...

    African Journals Online (AJOL)

    The study attempts to assess the current trends, impact and constraints of fisheries extension services to artisanal fishers in Ogun Waterside Local Government Area of Ogun State. The survey approach was used to generate the needed data using 120 structured questionnaires. Simple statistical techniques such as means ...

  15. Tampa Bay Extension Agents’ Views of Urban Extension: Philosophy and Program Strategies

    Directory of Open Access Journals (Sweden)

    Amy Harder

    2017-06-01

    Full Text Available The purpose of this article was to explore the concept of urban Extension as perceived by Extension agents within the Tampa Bay area, one of Florida’s fastest growing metropolitan areas. From a theoretical perspective, it is critical to understand Extension agents’ beliefs about urban Extension because behaviors are directly related to attitudes (Ajzen, 2012. In 2016, a qualitative investigation was undertaken to explore the perspectives of 23 agents working within the Tampa Bay area. Results showed the majority of agents believed that context and client needs are unique for urban Extension, and that to a lesser extent, unique agent expertise is required. Further, these beliefs impacted how agents reported their approach to programming, with an emphasis on providing convenience and seeking partnerships. Difficulties were identified related to identifying the role of Extension in a resource-rich environment of service providers, which contributed to the existence of a perceived disconnect between urban audiences and Extension. Opportunities exist for Extension leadership to provide strategic organizational support that will enhance agents’ abilities to succeed in the metropolitan environment.

  16. Extension Study Group Members View Their Clubs and Extension Home Economists. ANREI Publication No. 28.

    Science.gov (United States)

    Miller, Mason E.

    The data presented in this report were selected from a 1972 study of Michigan Extension Study Group (ESG) members. Included are data descriptive of the women themselves and their situation (area and type of home, age, income, ESG experience, and especially their attitudes toward their ESG and their Extension Home Economists). Selected findings are…

  17. 78 FR 65242 - Occupational Exposure to Crystalline Silica; Extension of Comment Period; Extension of Period To...

    Science.gov (United States)

    2013-10-31

    ... Exposure to Crystalline Silica; Extension of Comment Period; Extension of Period To Submit Notices of... Notice of Proposed Rulemaking (NPRM) on Occupational Exposure to Crystalline Silica for an additional 47... occupational exposure to respirable crystalline silica (78 FR 56274). This notice requested written comments by...

  18. Tensor extension of the Poincar\\'e algebra

    OpenAIRE

    Soroka, Dmitrij V.; Soroka, Vyacheslav A.

    2004-01-01

    A tensor extension of the Poincar\\'e algebra is proposed for the arbitrary dimensions. Casimir operators of the extension are constructed. A possible supersymmetric generalization of this extension is also found in the dimensions $D=2,3,4$.

  19. Extensive xanthogranulomatous cystitis mimicking bladder cancer

    Directory of Open Access Journals (Sweden)

    Amir M Ali

    2014-01-01

    Full Text Available Xanthogranulomatous cystitis (XC is a rare benign disease of unknown etiology. A 39-year-old female presented with 2 month history of urgency, dysuria, lower abdominal mass. On physical examination a hard hypogastric mass was present fixed to the rectus muscle. Computerized tomography (CT abdomen showed heterogeneous enhancing mass arising from the anterior bladder wall with infiltration of the overlying parietal wall. Cystoscopy revealed extensive growth involving the entire wall of the bladder. A biopsy showed cystitis with focal areas suggestive of urothelial neoplasia of unknown malignant potential. Suspecting bladder cancer, we proceeded with radical cystectomy with ileal conduit. Histopathology revealed cystitis cystica with XC of the entire bladder. This is, to our knowledge, the first time that a case has been found to be so extensive with infiltration of the parietal wall and second time that radical cystectomy has been performed for XC.

  20. Traumatic knee extension deficit (the locked knee)

    DEFF Research Database (Denmark)

    Helmark, I C; Neergaard, K; Krogsgaard, M R

    2007-01-01

    In the present study we investigated the validity of magnetic resonance imaging (MRI) and arthroscopy in knees with acute, traumatic extension deficit (the "locked knee"), and evaluated whether arthroscopy of knees with no mechanical pathology could be avoided by MRI evaluation. The study consisted...... of 50 patients who had an acute, traumatic extension deficit of the knee. All patients were submitted to MRI prior to arthroscopy. Following MRI and surgery, standardized forms were filled out, attempting to objectify the findings. The orthopaedic surgeon was not aware of the MRI result prior to surgery......, the following results were calculated for the overall appearance of a lesion able to cause locking: Positive predictive value = 0.85, negative predictive value = 0.77, sensitivity = 0.95, specificity = 0.53. Two knees were erroneously evaluated with no mechanical locking at MRI (one bucket-handle lesion and one...

  1. Army European Tour Extension: An Interdisciplinary Approach

    Science.gov (United States)

    1985-02-01

    Rollgleu Job -Family Enlisted Spousal Wellbeing Facilities Fit P.rceptin PerceptionCommunity of Familyr’. , Support Satisfacion Attend Religious...Extens+om Logit i model , . Family life -IFactor analysis) SIMOS .. . .% Economics Regressions, Job satisfaction."" ,. ,,~., ,l ’ .; " -C. 20. AUS ACT...amounts of the proposed extension bonuses as well as with increase in satis- Lam faction with job and family life. Smaller lump sum bonuses were (Continued

  2. Mathematical model of subscriber extension line

    OpenAIRE

    Petříková, Iva; Diviš, Zdeněk; Tesař, Zdeněk

    2012-01-01

    The paper focuses on measurement properties of metallic subscriber extension lines to build regression mathematical model for a symmetric pair cable. The regression model is compared with an analytical model based on a theoretical description of transfer parameters for this type of line. The output of the paper should demonstrate the impact of electromagnetic interference on the symmetric pair. The paper also describes the method to identify the interference sources and ...

  3. Extensions and degeneration of spectral triples

    DEFF Research Database (Denmark)

    Christensen, Erik; Ivan, Cristina

    2009-01-01

    To a compact non commutative metric space associated to a C*-algebra A and an extension E of A, we construct 2-parameter family of compact non commutative metric spaces associated to E. It is shown that under certain limits along paths in the parameter space the corresponding spaces converge...... in the quantum Gromov-Hausdorff metric towards either the given non commutative metric space or towards a compact non commutative metric space associated to the compact operators....

  4. Cauchy-Davenport theorem in group extensions

    CERN Document Server

    Karolyi, G

    2005-01-01

    Let A and B be nonempty subsets of a finite group G in which the order of the smallest nontrivial subgroup is not smaller than d=|A|+|B|-1. Then the product set AB has at least d elements. This extends a classical theorem of Cauchy and Davenport to noncommutative groups. We also generalize Vosper's inverse theorem in the same spirit, giving a complete description of the critical pairs. The proofs depend on the structure of group extensions.

  5. Stable Extensions with(out) Gravity

    DEFF Research Database (Denmark)

    Antipin, Oleg; Krog, Jens; Mojaza, Matin

    2014-01-01

    We investigate the vacuum stability as well as the gravitational corrections in extensions of the Standard Model featuring a new complex scalar, and two Dirac fermions for different choices of the hypercharge of the scalar and one of the two fermions. The neutral fermion acquires loop-induced mag...... and discover that the models can be compatible with the asymptotically safe gravity scenario at the price of a heavier Higgs and lighter top mass...

  6. Learning PrimeFaces extensions development

    CERN Document Server

    Jonna, Sudheer

    2014-01-01

    This book provides a step by step approach that explains the most important extension components and their features. All the major features are explained by using the JobHub application with supporting screenshots.If you are an intermediate to advanced level user (or developer) who already has a basic working knowledge of PrimeFaces, then this book is for you.The only thing you need to know is Java Server Faces(JSF).

  7. Deformed Fredkin spin chain with extensive entanglement

    Science.gov (United States)

    Salberger, Olof; Udagawa, Takuma; Zhang, Zhao; Katsura, Hosho; Klich, Israel; Korepin, Vladimir

    2017-06-01

    We introduce a new spin chain which is a deformation of the Fredkin spin chain and has a phase transition between bounded and extensive entanglement entropy scaling. In this chain, spins have a local interaction of three nearest neighbors. The Hamiltonian is frustration-free and its ground state can be described analytically as a weighted superposition of Dyck paths that depends on a deformation parameter t. In the purely spin 1/2 case, whenever t\

  8. Emergence of Extensively Drug Resistant Tuberculosis

    Centers for Disease Control (CDC) Podcasts

    2007-03-01

    Extensively drug-resistant tuberculosis (XDR TB) outbreaks have been reported in South Africa, and strains have been identified on 6 continents. Dr. Peter Cegielski, team leader for drug-resistant TB with the Division of Tuberculosis Elimination at CDC, comments on a multinational team's report on this emerging global public health threat.  Created: 3/1/2007 by Emerging Infectious Diseases.   Date Released: 3/26/2007.

  9. Extensive air showers in the classroom

    Science.gov (United States)

    Badalà, A.; Blanco, F.; La Rocca, P.; Pappalardo, G. S.; Pulvirenti, A.; Riggi, F.

    2007-09-01

    The basic properties of extensive air showers of particles produced in the interaction of a high-energy primary cosmic ray in the Earth's atmosphere are discussed in the context of educational cosmic ray projects involving undergraduate students and high-school teams. Simulation results produced by an air shower development code were made available on the Web by the use of ASCII files and EXCEL spreadsheets to allow people to carry out graphical and numerical analyses in cosmic ray physics.

  10. Conservative Intensional Extension of Tarski's Semantics

    Directory of Open Access Journals (Sweden)

    Zoran Majkić

    2013-01-01

    Full Text Available We considered an extension of the first-order logic (FOL by Bealer's intensional abstraction operator. Contemporary use of the term “intension” derives from the traditional logical Frege-Russell doctrine that an idea (logic formula has both an extension and an intension. Although there is divergence in formulation, it is accepted that the “extension” of an idea consists of the subjects to which the idea applies, and the “intension” consists of the attributes implied by the idea. From the Montague's point of view, the meaning of an idea can be considered as particular extensions in different possible worlds. In the case of standard FOL, we obtain a commutative homomorphic diagram, which is valid in each given possible world of an intensional FOL: from a free algebra of the FOL syntax, into its intensional algebra of concepts, and, successively, into an extensional relational algebra (different from Cylindric algebras. Then we show that this composition corresponds to the Tarski's interpretation of the standard extensional FOL in this possible world.

  11. LIMB Demonstration Project Extension and Coolside Demonstration

    Energy Technology Data Exchange (ETDEWEB)

    Goots, T.R.; DePero, M.J.; Nolan, P.S.

    1992-11-10

    This report presents results from the limestone Injection Multistage Burner (LIMB) Demonstration Project Extension. LIMB is a furnace sorbent injection technology designed for the reduction of sulfur dioxide (SO[sub 2]) and nitrogen oxides (NO[sub x]) emissions from coal-fired utility boilers. The testing was conducted on the 105 Mwe, coal-fired, Unit 4 boiler at Ohio Edison's Edgewater Station in Lorain, Ohio. In addition to the LIMB Extension activities, the overall project included demonstration of the Coolside process for S0[sub 2] removal for which a separate report has been issued. The primary purpose of the DOE LIMB Extension testing, was to demonstrate the generic applicability of LIMB technology. The program sought to characterize the S0[sub 2] emissions that result when various calcium-based sorbents are injected into the furnace, while burning coals having sulfur content ranging from 1.6 to 3.8 weight percent. The four sorbents used included calcitic limestone, dolomitic hydrated lime, calcitic hydrated lime, and calcitic hydrated lime with a small amount of added calcium lignosulfonate. The results include those obtained for the various coal/sorbent combinations and the effects of the LIMB process on boiler and plant operations.

  12. EXTENSION EDUCATION SYMPOSIUM: Getting the most out of your extension appointment and still having a life.

    Science.gov (United States)

    Powers, W; Cockett, N; Lardy, G

    2017-04-01

    Managing the demands of an academic appointment in extension can be a challenging task. Demands from constituent groups, expectations of supervisors, and rigors of promotion and tenure processes can create pressures that young faculty did not expect. Throw in spousal and family duties and you have created a situation that many will find hard to navigate. However, there are ways to cope and, even better news, there are ways to excel in meeting the demands of an academic appointment and enjoying life. Because many new extension faculty members do not have prior experience in extension, best practices in documenting programs and extension scholarship over the pretenure period are provided in this paper. Appointments that include both research and extension are quite common at many land grant universities. The advantages of joint appointments are numerous and include the fact that more and more grant agencies are seeking integrated research, teaching, and/or extension projects. However, the time demands of joint appointments can be challenging. Joint appointments can be designed to help faculty members conduct important translational research and have it be applied in a production setting. By seeking commonalities in research and extension efforts, joint appointments can be very synergistic. Development of highly successful programs requires planning on the front end with an emphasis on an in-depth needs assessment to determine stakeholder needs for both research and extension. Impact assessment should be part of this planning effort. Performing as a successful extension faculty member while maintaining relationships outside of work is challenging and requires deliberate effort on the part of employees and supervisors to realize there is more to life than work. Some authors have referred to this as work-life balance, but it may be more helpful to think of it as work-life effectiveness. To do this, one needs to 1) define what success looks like, 2) set boundaries and

  13. Supervisory skills of extension managers in Sekhukhune District of ...

    African Journals Online (AJOL)

    ... namely at the supervisory level (Sub-District Extension Coordinators) and the top extension management level (Extension Heads). These are the two management levels that can potentially have the biggest influence on the efficiency of extension delivery. Keywords: management, leadership skills, differential perception, ...

  14. Constraints in the implementation of crop protection extension ...

    African Journals Online (AJOL)

    ... management of research information; basing distribution of needed inputs on full time farming criterion, involving more crop protectionists in extension work, removal of non-extension function from extension, provision of logistic supports and periodic staff training on crop protection extension methodology, communication, ...

  15. Private Agricultural Extension System in Kenya: Practice and Policy Lessons

    Science.gov (United States)

    Muyanga, Milu; Jayne, T. S.

    2008-01-01

    Private extension system has been at the centre of a debate triggered by inefficient public agricultural extension. The debate is anchored on the premise that the private sector is more efficient in extension service delivery. This study evaluates the private extension system in Kenya. It employs qualitative and quantitative methods. The results…

  16. Journal of Agricultural Extension Vol.17 (2) December, 2013 ISSN ...

    African Journals Online (AJOL)

    ONIKOYI

    Turkey and offers a model for mainstreaming it in extension programming. Keywords. Agricultural extension in Turkey, Communication for extension Development. Introduction. Agricultural extension in Turkey started in 1931 .... Use social networking web sites a. Facebook b. Twitter c. LinkedIn d. Orkut. 90.8. 70.4. 3.1. 2.0.

  17. CT of perineural tumor extension: pterygopalatine fossa

    Energy Technology Data Exchange (ETDEWEB)

    Curtin, H.D.; Williams, R.; Johnson, J.

    1985-01-01

    Tumors of the oral cavity and paranasal sinuses can spread along nerves to areas apparently removed from the primary tumor. In tumors of the palate, sinuses, and face, this perineural spread usually involves the maxillary division of the trigeminal nerve. The pterygopalatine fossa is a pathway of the maxillary nerve and becomes a key landmark in the detection of neural metastasis by computed tomography (CT). Obliteration of the fat in the fossa suggests pathology. Case material illustrating neural extension is presented and the CT findings are described.

  18. Subintegrality, invertible modules and Laurent polynomial extensions

    Indian Academy of Sciences (India)

    N그(A,B): kernel of the map 그(A[X],B[X]) → 그(A,B) (Here the map is induced by the B-algebra homomorphism B[X] → B given by X ↦→ 0). Recall from §2 of [4] that for any commutative ring extension A ⊆ B, we have the exact sequence. 1 → U(A) → U(B) → 그(A,B) → Pic A → Pic B. Applying M, K we obtain the chain ...

  19. Analytic extension of the nuclear algebraic potential

    Energy Technology Data Exchange (ETDEWEB)

    Lichtenthaeler, R. (Departamento de Fisica Nuclear, Laboratorio do Pelletron, Universidade de Sao Paulo, Caixa Postal 20516, 01452-990 Sao Paulo, Sao Paulo (Brazil)); Gomes, L.C. (Grupo de Fisica Nuclear Teorica e Fenomenologia de Particulas Elementares Instituto de Fisica Universidade de Sao Paulo, Caixa Postal 20516, 01498-970 Sao Paulo, Sao Paulo (Brazil))

    1994-12-01

    An analytic extension of the nuclear algebraic potential in the complex energy and angular momentum planes is discussed and an approximation for the algebraic potential in agreement with the known analytic properties of the [ital S]-matrix is proposed. The invariance of the energy spectrum of the Coulomb part of the interaction is established. The results are applied to the Regge pole analysis of the [sup 12]C+[sup 24]Mg elastic collision at [ital E][sub [ital l][ital a][ital b

  20. A CART extension using Quadratic Decision Borders

    DEFF Research Database (Denmark)

    Hartelius, Karsten

    1999-01-01

    -space into subsets which are successively more class-homogeneous. Guided by the fact that class-distributions in feature-space are very often hyper-elliptical shaped, we give an extension to the original CART which also uses quadratic shaped decision borders which can be modelled by a mean-vector and a dispersion......In this article we put forward an extention to the hierarchical CART classification method which uses quadratic decision borders. The original CART applies univariate splits on individual variables as well as splits on combinations of variables to recursively partition the feature...

  1. Software extension and integration with type classes

    DEFF Research Database (Denmark)

    Lämmel, Ralf; Ostermann, Klaus

    2006-01-01

    expressiveness, by using the language concept of \\emph{type classes}, as it is available in the functional programming language Haskell. A detailed comparison with related work shows that type classes provide a powerful framework in which solutions to known software extension and integration problems can......The abilities to extend a software module and to integrate a software module into an existing software system without changing existing source code are fundamental challenges in software engineering and programming-language design. We reconsider these challenges at the level of language...... be provided. We also pinpoint several limitations of type classes in this context....

  2. Extensive Variation in Chromatin States Across Humans

    KAUST Repository

    Kasowski, M.

    2013-10-17

    The majority of disease-associated variants lie outside protein-coding regions, suggesting a link between variation in regulatory regions and disease predisposition. We studied differences in chromatin states using five histone modifications, cohesin, and CTCF in lymphoblastoid lines from 19 individuals of diverse ancestry. We found extensive signal variation in regulatory regions, which often switch between active and repressed states across individuals. Enhancer activity is particularly diverse among individuals, whereas gene expression remains relatively stable. Chromatin variability shows genetic inheritance in trios, correlates with genetic variation and population divergence, and is associated with disruptions of transcription factor binding motifs. Overall, our results provide insights into chromatin variation among humans.

  3. On Shor's Channel Extension and Constrained Channels

    Science.gov (United States)

    Holevo, A. S.; Shirokov, M. E.

    Several equivalent formulations of the additivity conjecture for constrained channels, which formally is substantially stronger than the unconstrained additivity, are given. To this end a characteristic property of the optimal ensemble for such a channel is derived, generalizing the maximal distance property. It is shown that the additivity conjecture for constrained channels holds true for certain nontrivial classes of channels. After giving an algebraic formulation for Shor's channel extension, its main asymptotic property is proved. It is then used to show that additivity for two constrained channels can be reduced to the same problem for unconstrained channels, and hence, ``global'' additivity for channels with arbitrary constraints is equivalent to additivity without constraints.

  4. Emergency Anaesthetic Management of Extensive Thoracic Trauma

    Directory of Open Access Journals (Sweden)

    H C Chandola

    2007-01-01

    Full Text Available High speed vehicles, drug abuse, alcohol and easy availability of handguns are the main reasons of increasing number of trauma especially thoracic trauma. Anaesthesiologist plays an important role in the management of extensive thoracic trauma. Thoracic trauma, penetrating or blunt, may cause damage to organs suspended in thorax viz. pleura, lungs, heart, great vessels, trachea and oesophagus. It may lead to pneumothorax, cardiac tamponade or life threatening haemorrhage. With aggressive care and management of these factors, majority of patients can survive and return to normal life.

  5. Radar reflection off extensive air showers

    Directory of Open Access Journals (Sweden)

    Werner F.

    2013-06-01

    Full Text Available We investigate the possibility of detecting extensive air showers by the radar technique. Considering a bistatic radar system and different shower geometries, we simulate reflection of radio waves off the static plasma produced by the shower in the air. Using the Thomson cross-section for radio wave reflection, we obtain the time evolution of the signal received by the antennas. The frequency upshift of the radar echo and the power received are studied to verify the feasibility of the radar detection technique.

  6. Brand Extension: a Case Study of Starbucks

    OpenAIRE

    Bokii, Artem

    2017-01-01

    The thesis investigates the topic of brand extension and its importance in the business practice of companies. The theoretical part of the research outlines the key theoretical aspects related to brand and brand extension. The practical part investigates the case study of Starbucks brand extension and compares it with other famous brand extension cases. The paper illustrates how Starbucks brand extension from coffee onto the ice cream market had been successful on the initial stage, and how i...

  7. A Case of Extensive polyostotic fibrous dysplasia

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Byung Do [Dept. of Oral and Maxillofacial Radiology, School of Dentistry, Wonkwang University, Iksan (Korea, Republic of); Hwang, Eui Hwan; Lee, Sang Rae [Dept. of Oral and Maxillofacial Radiology, School of Dentistry, Kyunghee University, Seoul (Korea, Republic of)

    2000-06-15

    Fibrous dysplasia is a benign disorder of bone consisting of intramedullary proliferation of fibrous tissue and irregularly distributed, poorly developed bone. The disease manifests itself in the monostotic form in which only one bone is involved and the polyostotic form in which multiple bones at different sites are affected. We reported a extensive case of polyostotic fibrous dysplasia with involvement of craniofacial bones, mandible, ribs, extremities. A 18-year-old man showed remarkable right facial swelling who had been treated on right femur 3 years ago with a bone graft for pathologic fracture and he recognized facial swelling 5 years ago. Extraoral radiograms and computed tomogram showed diffuse sclerosis with a ground glass appearance of the most calvarial bones, facial bones. The right mandibular lesion showed very expansible lesion with mottled appearance. Bone scans showed multifocal increased uptakes in craniofacial bones, right mandible, bilaterally in ribs, humerus, femur, tibia and characteristic various deformity of right femur (shepherd's crook deformity). This case showed exceptionally bilateral, extensive nature of bone lesion and didn't show any features of skin pigmentation and endocrine disturbances.

  8. Cmapanalysis: an extensible concept map analysis tool

    Directory of Open Access Journals (Sweden)

    Alberto J. Cañas

    2013-03-01

    Full Text Available Concept maps are used extensively as an assessment tool, and the literature is abundant with studies on the use of concept maps for assessment and on the assessment of concept maps. The assessment of concept maps can be an arduous process, in particular when assessing a large number of maps. CmapAnalysis is a software tool that facilitates performing various analysis measures on a collection of concept maps. A set of measures that consider size, quality and structure properties of the maps are included. The program is designed to be extensible, allowing users to add their own measures. The program is not intended to replace the individual evaluation of concept maps by teachers and instructors, as it does not capable of “understanding” the content of the maps. It is aimed at researchers who are looking for more general trends and measures across a large number of maps, and who can extend it with their own measures. The output of CmapAnalysis is an Excel spreadsheet that can be further analyzed.

  9. Sampling approaches for extensive surveys in nematology.

    Science.gov (United States)

    Prot, J C; Ferris, H

    1992-12-01

    Extensive surveys of the frequency and abundance of plant-parasitic nematodes over large geographic areas provide useful data of unknown reliability. Time, cost, and logistical constraints may limit the sampling intensity that can be invested at any survey site. We developed a computer program to evaluate the probability of detection and the reliability of population estimates obtained by different strategies for collecting one sample of 10 cores from a field. We used data from two fields that had been sampled systematically and extensively as the basis for our analyses. Our analyses indicate that, at least for those two fields, it is possible to have a high probability of detecting the presence of nematode species and to reliably estimate abundance, with a single 10-core soil sample from a field. When species were rare or not uniformly distributed in a field, the probability of detection and reliability of the population estimate were correlated with the distance between core removal sites. Increasing the prescribed distance between cores resulted in the composite sample representing a wider range of microenvironments in the field.

  10. Life extension by calorie restriction in humans.

    Science.gov (United States)

    Everitt, Arthur V; Le Couteur, David G

    2007-10-01

    Long-term reduction in energy intake in the diet (calorie restriction [CR]) extends the life of the laboratory rat by about 25%. However, in humans there are no life-long studies of CR, but only short-term trials which indicate that 20% CR acting over periods of 2-6 years is associated with reduced body weight, blood pressure, blood cholesterol, and blood glucose--risk factors for the major killer diseases of cardiovascular disease and diabetes. In addition, recent research has shown that CR for 6 months is able to improve biomarkers for longevity (deep body temperature and plasma insulin) and thus should increase life expectancy. The magnitude of the life-extension effect of CR in humans can only be estimated. The Okinawans, the longest-lived people on earth, consume 40% fewer calories than the Americans and live only 4 years longer. Similarly, women in United States consume 25% fewer calories than men and live 5 years longer. From the survival studies of overweight and obese people, it is estimated that long-term CR to prevent excessive weight gain could add only 3-13 years to life expectancy. Thus the effects of CR on human life extension are probably much smaller than those achieved by medical and public health interventions, which have extended life by about 30 years in developed countries in the 20th century, by greatly reducing deaths from infections, accidents, and cardiovascular disease.

  11. Improved Extension Neural Network and Its Applications

    Directory of Open Access Journals (Sweden)

    Yu Zhou

    2014-01-01

    Full Text Available Extension neural network (ENN is a new neural network that is a combination of extension theory and artificial neural network (ANN. The learning algorithm of ENN is based on supervised learning algorithm. One of important issues in the field of classification and recognition of ENN is how to achieve the best possible classifier with a small number of labeled training data. Training data selection is an effective approach to solve this issue. In this work, in order to improve the supervised learning performance and expand the engineering application range of ENN, we use a novel data selection method based on shadowed sets to refine the training data set of ENN. Firstly, we use clustering algorithm to label the data and induce shadowed sets. Then, in the framework of shadowed sets, the samples located around each cluster centers (core data and the borders between clusters (boundary data are selected as training data. Lastly, we use selected data to train ENN. Compared with traditional ENN, the proposed improved ENN (IENN has a better performance. Moreover, IENN is independent of the supervised learning algorithms and initial labeled data. Experimental results verify the effectiveness and applicability of our proposed work.

  12. Nasal dermoids without intracranial extension in teenagers.

    Science.gov (United States)

    Dolzal, P; Hanzelová, J

    2010-01-01

    Nasal dermoid cysts are benign, cystic midline masses. They contain mature tissues and often pocket hair, fat or sebum. Patients usually present with nasal enlargement or with a wide nasal dorsum with or without a fistula, causing an unacceptable cosmetic appearance. To define a reliable surgical approach and method of removing dermoid with no intracranial extension in adolescent age. We retrospectively present diagnostic and therapeutic procedures in three teenagers ages 15, 17 and 18. All patients underwent prior surgeries at different hospitals. In the first case, the incision and exstirpation of the fistula's opening, followed by the fistula's canal, was performed. In the other two patients, the nasal dermoids were removed via the open approach with the transcollumelar incision. In all patients, we performed rhinoplasty with osteotomies to achieve an improved cosmetic effect. The esthetic results are presented. The diagnosis of nasal swelling requires imaging. Total excision of the cyst is considered the casual treatment. The open rhinoplasty is an adequate method in patients with nasal dermoids without an intracranial extension. Experienced surgeons should manage the functional and esthetical aspects together during the same surgery.

  13. Extension of yeast chronological lifespan by methylamine.

    Directory of Open Access Journals (Sweden)

    Sanjeev Kumar

    Full Text Available BACKGROUND: Chronological aging of yeast cells is commonly used as a model for aging of human post-mitotic cells. The yeast Saccharomyces cerevisiae grown on glucose in the presence of ammonium sulphate is mainly used in yeast aging research. We have analyzed chronological aging of the yeast Hansenula polymorpha grown at conditions that require primary peroxisome metabolism for growth. METHODOLOGY/PRINCIPAL FINDINGS: The chronological lifespan of H. polymorpha is strongly enhanced when cells are grown on methanol or ethanol, metabolized by peroxisome enzymes, relative to growth on glucose that does not require peroxisomes. The short lifespan of H. polymorpha on glucose is mainly due to medium acidification, whereas most likely ROS do not play an important role. Growth of cells on methanol/methylamine instead of methanol/ammonium sulphate resulted in further lifespan enhancement. This was unrelated to medium acidification. We show that oxidation of methylamine by peroxisomal amine oxidase at carbon starvation conditions is responsible for lifespan extension. The methylamine oxidation product formaldehyde is further oxidized resulting in NADH generation, which contributes to increased ATP generation and reduction of ROS levels in the stationary phase. CONCLUSION/SIGNIFICANCE: We conclude that primary peroxisome metabolism enhanced chronological lifespan of H. polymorpha. Moreover, the possibility to generate NADH at carbon starvation conditions by an organic nitrogen source supports further extension of the lifespan of the cell. Consequently, the interpretation of CLS analyses in yeast should include possible effects on the energy status of the cell.

  14. Extensive Growth of an Anaplastic Meningioma

    Directory of Open Access Journals (Sweden)

    Hajrullah Ahmeti

    2013-01-01

    Full Text Available We present the case of a 30-year-old male patient with an almost complete destruction of the calvarial bone through an anaplastic meningioma diagnosed in line with dizziness. Neuroimaging revealed an extensive growing, contrast enhancing lesion expanding at the supra- and infratentorial convexity, infiltrating and destroying large parts of the skull, and infiltrating the skin. Due to progressive ataxia and dysarthria with proven tumor growth in the posterior fossa in the continuing course, parts of the tumor were resected. A surgical procedure with the aim of complete tumor resection in a curative manner was not possible. Six months after the first operation, due to a new tumor progression, most extensive tumor resection was performed. Due to the aggressive and destructive growth with a high rate of recurrence and tendency of metastases, anaplastic meningiomas can be termed as malignant tumors. The extrinsic growth masks the tumor until they reach a size, which makes these tumors almost unresectable. In the best case scenarios, the five-year survival is about 50%. With the presented case, we would like to show the aggressive behavior of anaplastic meningiomas in a very illustrative way. Chemotherapy, radiotherapy, and surgery reach their limits in this tumor entity.

  15. On Noisy Extensions of Nonholonomic Constraints

    Science.gov (United States)

    Gay-Balmaz, François; Putkaradze, Vakhtang

    2016-12-01

    We propose several stochastic extensions of nonholonomic constraints for mechanical systems and study the effects on the dynamics and on the conservation laws. Our approach relies on a stochastic extension of the Lagrange-d'Alembert framework. The mechanical system we focus on is the example of a Routh sphere, i.e., a rolling unbalanced ball on the plane. We interpret the noise in the constraint as either a stochastic motion of the plane, random slip or roughness of the surface. Without the noise, this system possesses three integrals of motion: energy, Jellet and Routh. Depending on the nature of noise in the constraint, we show that either energy, or Jellet, or both integrals can be conserved, with probability 1. We also present some exact solutions for particular types of motion in terms of stochastic integrals. Next, for an arbitrary nonholonomic system, we consider two different ways of including stochasticity in the constraints. We show that when the noise preserves the linearity of the constraints, then energy is preserved. For other types of noise in the constraint, e.g., in the case of an affine noise, the energy is not conserved. We study in detail a class of Lagrangian mechanical systems on semidirect products of Lie groups, with "rolling ball type" constraints. We conclude with numerical simulations illustrating our theories, and some pedagogical examples of noise in constraints for other nonholonomic systems popular in the literature, such as the nonholonomic particle, the rolling disk and the Chaplygin sleigh.

  16. Extensive hypertrophic lupus erythematosus: Atypical presentation

    Directory of Open Access Journals (Sweden)

    Tarun Narang

    2012-01-01

    Full Text Available Lupus erythematosus (LE is a disease with a wide spectrum of cutaneous and systemic manifestations. Clinical features of patients with LE show a great variation, and for this reason it is difficult to develop a unifying concept of this disease. Our objective is to present a case of hypertrophic LE with atypical morphology and extensive involvement, who responded favorably to isotretinoin. Diagnosis of hypertrophic lupus erythematosus (HLE was confirmed by characteristic histopathological findings. Combination therapy with isotretinoin and hydroxychloroquine resulted in flattening and repression of previously refractory skin lesions. Sometimes, HLE lesions may present a diagnostic and therapeutic dilemma. In long standing lesions, squamous cell carcinoma may arise. Therefore, HLE requires adequate therapy with clinical and histopathological follow up.

  17. BB-CLIPS: Blackboard extensions to CLIPS

    Science.gov (United States)

    Orchard, Robert A.; Diaz, Aurora C.

    1990-01-01

    This paper describes a set of extensions made to CLIPS version 4.3 that provide capabilities similar to the blackboard control architecture described by Hayes-Roth. There are three types of additions made to the CLIPS shell. The first extends the syntax to allow the specification of blackboard locations for CLIPS facts. The second implements changes in CLIPS rules and the agenda manager that provide some of the powerful features of the blackboard control architecture. These additions provide dynamic prioritization of rules on the agenda allowing control strategies to be implemented that respond to the changing goals of the system. The final category of changes support the needs of continuous systems, including the ability for CLIPS to continue execution with an empty agenda.

  18. An Extension of Gregus Fixed Point Theorem

    Directory of Open Access Journals (Sweden)

    J. O. Olaleru

    2007-03-01

    Full Text Available Let C be a closed convex subset of a complete metrizable topological vector space (X,d and T:C→C a mapping that satisfies d(Tx,Ty≤ad(x,y+bd(x,Tx+cd(y,Ty+ed(y,Tx+fd(x,Ty for all x,y∈C, where 0extension of the results of several authors, is proved in this paper. In addition, we use the Mann iteration to approximate the fixed point of T.

  19. Learning investment indicators through data extension

    Science.gov (United States)

    Dvořák, Marek

    2017-07-01

    Stock prices in the form of time series were analysed using single and multivariate statistical methods. After simple data preprocessing in the form of logarithmic differences, we augmented this single variate time series to a multivariate representation. This method makes use of sliding windows to calculate several dozen of new variables using simple statistic tools like first and second moments as well as more complicated statistic, like auto-regression coefficients and residual analysis, followed by an optional quadratic transformation that was further used for data extension. These were used as a explanatory variables in a regularized logistic LASSO regression which tried to estimate Buy-Sell Index (BSI) from real stock market data.

  20. Post-traumatic extensive knee ganglion cyst

    Directory of Open Access Journals (Sweden)

    Mehran Mahvash

    2011-08-01

    Full Text Available A rare case of a posttraumatic extensive ganglion cyst of the anterolateral thigh with connection to the knee joint is presented. A 54- year-old man presented a palpable mass in the anterolateral region of his right thigh with a 15 months existing sense of fullness and tightness. He had an accident with his bicycle 21 months ago. Magnetic resonance imaging (MRI was performed showing a cyst inside the quadriceps femoris muscle between vastus lateralis and intermedius with connection to recessus suprapatellaris and knee joint. In addition MRI detected a traumatic lesion in the quadriceps femoris tendon in the near of the knee joint. The ganglion cyst was 18 cm long and was excised completely. Intraope - ratively, the knee joint connection was confirmed and excised as well. The ganglion cyst was filled with a gelatinous and viscous fluid.

  1. Extensive IT outsourcing: advice from providers.

    Science.gov (United States)

    Smith, Mike; Whiting, Stacilee

    2007-01-01

    In summary, providers are reporting some benefits related to resources and knowledge, improved service levels/performance and stronger IT staff/leadership. Also, on average, providers are reporting satisfactory experiences with application support and CIO outsourcing. However, not all of their expectations are being met, and some providers have discontinued outsourcing due to unmet expectations. Clearly, outsourcing is an option one must research in depth--it is not for everyone. When one evaluates the results of extensive IT outsourcing, it becomes easier to see what outsourcing mix and firm may be a good match for your organization's needs and expected outcomes. As you decide upon the outsourcing mix and firm that is right for you, providers advise you to pay special attention to contractual arrangements. With adequate research and contractual provisions, organizations can find the outsourcing mix that is right for them.

  2. Supersymmetric Extension of Technicolor & Fermion Mass Generation

    DEFF Research Database (Denmark)

    Antola, Matti; Di Chiara, Stefano; Sannino, Francesco

    2012-01-01

    We provide a complete extension of Minimal Walking Technicolor able to account for the standard model fermion masses. The model is supersymmetric at energies greater or equal to the technicolor compositeness scale. We integrate out, at the supersymmetry breaking scale, the elementary Higgses. We...... use the resulting four-fermion operators to derive the low energy effective theory. We then determine the associated tree-level vacuum and low energy spectrum properties. Furthermore we investigate the phenomenological viability of the model by comparing its predictions with electroweak precision...... tests and experimental bounds on the mass spectrum. We then turn to the composite Higgs phenomenology at the LHC and show that current data are already constraining the parameter space of the model....

  3. Gemcitabine-Induced Extensive Skin Necrosis

    Directory of Open Access Journals (Sweden)

    Sara D'epiro

    2012-01-01

    Full Text Available An 82-year-old woman presented with oedema and extensive necrotic ulcerative lesions on the back side of her lower limbs, emerging after the second cycle of chemotherapy consisting of Gemcitabine for metastatic pancreatic cancer. The absence of any convincing argument in favor of cardiovascular or autoimmune disease led us to attribute the onset of skin necrosis to chemotherapy administration. Although skin ischemia has also been described as a paraneoplastic syndrome, in this case we could observe a temporal and causal relationship to Gemcitabine infusion. Recently, this drug has been associated with important vascular side effects; its vascular toxicity is in fact higher than previously estimated. To our knowledge, careful attention should be reserved to neoplastic patients candidated to Gemcitabine administration, especially if previously affected by arterial vascular disease, venous thromboembolism, or collagenoses.

  4. Extensive enactivism: why keep it all in?

    Science.gov (United States)

    Hutto, Daniel D; Kirchhoff, Michael D; Myin, Erik

    2014-01-01

    Radical enactive and embodied approaches to cognitive science oppose the received view in the sciences of the mind in denying that cognition fundamentally involves contentful mental representation. This paper argues that the fate of representationalism in cognitive science matters significantly to how best to understand the extent of cognition. It seeks to establish that any move away from representationalism toward pure, empirical functionalism fails to provide a substantive "mark of the cognitive" and is bereft of other adequate means for individuating cognitive activity. It also argues that giving proper attention to the way the folk use their psychological concepts requires questioning the legitimacy of commonsense functionalism. In place of extended functionalism-empirical or commonsensical-we promote the fortunes of extensive enactivism, clarifying in which ways it is distinct from notions of extended mind and distributed cognition.

  5. Extensive Enactivism: Why Keep it All in?

    Directory of Open Access Journals (Sweden)

    Daniel Douglas Hutto

    2014-09-01

    Full Text Available Radical enactive and embodied approaches to cognitive science oppose the received view in the sciences of the mind in denying that cognition fundamentally involves contentful mental representation. This paper argues that the fate of representationalism in cognitive science matters significantly to how best to understand the extent of cognition. It seeks to establish that any move away from representationalism towards pure, empirical functionalism fails to provide a substantive ‘mark of the cognitive’ and is bereft of other adequate means for individuating cognitive activity. It also argues that giving proper attention to the way the folk use their psychological concepts requires questioning the legitimacy of commonsense functionalism. In place of extended functionalism – empirical or commonsensical – we promote the fortunes of extensive enactivism, clarifying in which ways it is distinct from notions of extended mind and distributed cognition.

  6. Adaptive distributional extensions to DFR ranking

    DEFF Research Database (Denmark)

    Petersen, Casper; Simonsen, Jakob Grue; Järvelin, Kalervo

    2016-01-01

    Divergence From Randomness (DFR) ranking models assume that informative terms are distributed in a corpus differently than non-informative terms. Different statistical models (e.g. Poisson, geometric) are used to model the distribution of non-informative terms, producing different DFR models....... An informative term is then detected by measuring the divergence of its distribution from the distribution of non-informative terms. However, there is little empirical evidence that the distributions of non-informative terms used in DFR actually fit current datasets. Practically this risks providing a poor...... separation between informative and non-informative terms, thus compromising the discriminative power of the ranking model. We present a novel extension to DFR, which first detects the best-fitting distribution of non-informative terms in a collection, and then adapts the ranking computation to this best...

  7. A Moodle extension to book online labs

    Directory of Open Access Journals (Sweden)

    Antonio C. Cardoso

    2005-11-01

    Full Text Available The social constructivist philosophy of Moodle makes it an excellent choice to deliver e-learning contents that require collaborative activities, such as those that are associated with online labs. In the case of online labs that enable web access to real devices (remote workbenches, access time should be reserved beforehand. A booking tool will avoid access conflicts and at the same time will help the students to organise their time and activities. This paper presents a Moodle extension that was developed within the Leonardo da Vinci MARVEL project, with the objective of meeting this requirement. The booking tool presented enables resource sharing in general and may be used to organise access to any type of scarce resources, such as to online labs and to the videoconferencing rooms that are needed to support collaborative activities.

  8. Extension of association models to complex chemicals

    DEFF Research Database (Denmark)

    Avlund, Ane Søgaard

    Summary of “Extension of association models to complex chemicals”. Ph.D. thesis by Ane Søgaard Avlund The subject of this thesis is application of SAFT type equations of state (EoS). Accurate and predictive thermodynamic models are important in many industries including the petroleum industry....... The SAFT EoS was developed 20 years ago, and a large number of papers on the subject has been published since, but many issues still remain unsolved. These issues are both theoretical and practical. The SAFT theory does not account for intramolecular association, it can only treat flexible chains, and does...... functional groups. It is also tested whether increasing the number of sites for DEA (diethanolamine) improves the results. It can be shown from experimental data that intramolecular association is dominating compared to intermolecular association in certain systems, and that the intramolecular association...

  9. Estimating Extensive Form Games in R

    Directory of Open Access Journals (Sweden)

    Brenton Kenkel

    2014-01-01

    Full Text Available This article introduces new software, the games package, for estimating strategic statistical models in R. In these models, the probability distribution over outcomes corresponds to the equilibrium of an underlying game form. We review such models and provide derivations for one example, including discussion of alternative motivations for the stochastic component of the models. We introduce the basic functionality of the games package, such as how to estimate players utilities for outcomes as a function of covariates. The package implements maximum likelihood estimation for the most commonly used models of strategic choice, including three extensive form games and an ultimatum bargaining model. The software also includes functions for bootstrapping, plotting fitted values with their confidence intervals, performing non-nested model comparisons, and checking global convergence failures. We use the new software to replicate Leblangs (2003 analysis of speculative currency attacks.

  10. Energy Extension Service Program planning manual

    Energy Technology Data Exchange (ETDEWEB)

    Liersch, Judith M.

    1979-06-01

    The manual is the first revision of the EES Program Planning Manual. At the states' request, there have been a number of changes to the state EES contacts list, and an updated list is included in this package as the revised Appendix D. Part I, Introduction, presents: How to Use the State Program Planning Manual and The Energy Extension Service Program. Part II, Applying for an EES Grant, presents: The Annual State Application for Financial Assistance; State Financial Assistance and Associated Requirements; Preparing the State Plan. Part III, Operating a State EES, presents: Start-Up Considerations; State Program Reporting; Recordkeeping and Financial Management. Part IV, DOE's Role, presents DOE Functions and Responsibilities and Special Cases: Development and Implementation of a State Plan by the EES Director and Administrative Review.

  11. Production Flexibility in Extensive Beef Farming Systems

    Directory of Open Access Journals (Sweden)

    Laura Astigarraga

    2011-03-01

    Full Text Available The aim of this work is to assess the flexibility of production allowed by extensive production conditions faced with variations in the environment, i.e., market variations and climatic fluctuations, of Limousin beef systems. The study used a case-based methodology in which seven beef farms with less than 1 LU/ha were chosen. Data collection was based on three interviews using a semistructured questionnaire and on the analysis of productive and economic results over a 15-year period (1991-2005. The main evolution of these farms is related to a rise in work productivity associated with an increase in herd size. Herd increase was made possible by enlarging the area, the margin of intensification being limited in these regions. To take advantage of the enlarged land area, females were reared for fattening or for reproduction instead of selling them at weaning. The Limousin female provides a wide product mix because of its plasticity, as has been studied by several researchers. This mix flexibility is achieved by delaying product differentiation, a form of production flexibility that can reduce the risk of under-producing or over-producing varied product configurations. On the other hand, calves sold to the Italian market after weaning are generic products, associated with a flexible production process to overcome fluctuations in forage availability due to climatic variations. The introduction of maize silage for feeding acts as an alternative route, actual and potential, through the system to overcome unexpected forage shortage from natural grasslands as a result of droughts. The study shows that extensive farming systems have developed types of flexibility to match different factors of uncertainty from the environment. Finally, the issue of farm system performance is thus not so much a question of whether a farm is fit at a specific moment in time, but whether it transforms into a less or more sustainable orientation.

  12. A Needs Assessment of Aquaculture Extension Agents, Specialists, and Program Administrators in Extension Programming

    Science.gov (United States)

    Schwarz, Michael H.; Gibson, Jerry

    2010-01-01

    The study reported here identified continuing education and training needs of aquaculture Extension agents, specialists, and program administrators in 10 competency areas relating to the need for continuing education or training. Fourteen resources on the AquaNIC Web site were also evaluated, as was the efficacy of the AQUA-EXT listserv. Data were…

  13. Bibliography of U.S. Extension and Extension-related Publications on Nematodes.

    Science.gov (United States)

    1988-10-01

    A listing was compiled of hematology publications available through the Cooperative Extension Service and similar organizations in the United States. It provides a convenient reference to current articles addressing many of the more applied aspects of plant nematology and nematode management.

  14. Parallel Extension Tectonics (PET): Early Cretaceous tectonic extension of the Eastern Eurasian continent

    Science.gov (United States)

    Liu, Junlai; Ji, Mo; Ni, Jinlong; Guan, Huimei; Shen, Liang

    2017-04-01

    The present study reports progress of our recent studies on the extensional structures in eastern North China craton and contiguous areas. We focus on characterizing and timing the formation/exhumation of the extensional structures, the Liaonan metamorphic core complex (mcc) and the Dayingzi basin from the Liaodong peninsula, the Queshan mcc, the Wulian mcc and the Zhucheng basin from the Jiaodong peninsula, and the Dashan magmatic dome within the Sulu orogenic belt. Magmatic rocks (either volcanic or plutonic) are ubiquitous in association with the tectonic extension (both syn- and post-kinematic). Evidence for crustal-mantle magma mixing are popular in many syn-kinematic intrusions. Geochemical analysis reveals that basaltic, andesitic to rhyolitic magmas were generated during the tectonic extension. Sr-Nd isotopes of the syn-kinematic magmatic rocks suggest that they were dominantly originated from ancient or juvenile crust partly with mantle signatures. Post-kinematic mafic intrusions with ages from ca. 121 Ma to Cenozoic, however, are of characteristic oceanic island basalts (OIB)-like trace element distribution patterns and relatively depleted radiogenic Sr-Nd isotope compositions. Integrated studies on the extensional structures, geochemical signatures of syn-kinematic magmatic rocks (mostly of granitic) and the tectono-magmatic relationships suggest that extension of the crust and the mantle lithosphere triggered the magmatisms from both the crust and the mantle. The Early Cretaceous tectono-magmatic evolution of the eastern Eurasian continent is governed by the PET in which the tectonic processes is subdivided into two stages, i.e. an early stage of tectonic extension, and a late stage of collapse of the extended lithosphere and transformation of lithospheric mantle. During the early stage, tectonic extension of the lithosphere led to detachment faulting in both the crust and mantle, resulted in the loss of some of the subcontinental roots, gave rise to

  15. sources and use of extension information among maize farmers

    African Journals Online (AJOL)

    DR ADESOPE

    JOURNAL OF AGRICULTURE AND SOCIAL RESEARCH (JASR) Vol. ... extension information is sourced through extension worker, the mass media ..... Finally, farmers in general, and rural farmers in particular, should be encouraged to seek.

  16. Achieving Impact at Scale through ICT-Enabled Extension Services ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    CIFSRF Phase 2). In Africa, agricultural extension services have the potential to grow markets and enhance food security for smallholder farmers. Agricultural extension uses scientific research to educate farmers and improve agricultural ...

  17. Lightweight Nozzle Extension for Liquid Rocket Engines Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The ARES J-2X requires a large nozzle extension. Currently, a metallic nozzle extension is being considered with carbon-carbon composite as a backup. In Phase 1,...

  18. Journal of Agricultural Extension Vol.17 (2) December, 2013 ISSN ...

    African Journals Online (AJOL)

    ONIKOYI

    ). However, the experiences of farmers are fast changing. Traditional extension services linked with production objectives and blanket recommendations can no longer meet farmers' expectations. Therefore, extension practitioners need to ...

  19. The XML approach to implementing space link extension service management

    Science.gov (United States)

    Tai, W.; Welz, G. A.; Theis, G.; Yamada, T.

    2001-01-01

    A feasibility study has been conducted at JPL, ESOC, and ISAS to assess the possible applications of the eXtensible Mark-up Language (XML) capabilities to the implementation of the CCSDS Space Link Extension (SLE) Service Management function.

  20. Extensible automated dispersive liquid–liquid microextraction

    Energy Technology Data Exchange (ETDEWEB)

    Li, Songqing; Hu, Lu; Chen, Ketao; Gao, Haixiang, E-mail: hxgao@cau.edu.cn

    2015-05-04

    Highlights: • An extensible automated dispersive liquid–liquid microextraction was developed. • A fully automatic SPE workstation with a modified operation program was used. • Ionic liquid-based in situ DLLME was used as model method. • SPE columns packed with nonwoven polypropylene fiber was used for phase separation. • The approach was applied to the determination of benzoylurea insecticides in water. - Abstract: In this study, a convenient and extensible automated ionic liquid-based in situ dispersive liquid–liquid microextraction (automated IL-based in situ DLLME) was developed. 1-Octyl-3-methylimidazolium bis[(trifluoromethane)sulfonyl]imide ([C{sub 8}MIM]NTf{sub 2}) is formed through the reaction between [C{sub 8}MIM]Cl and lithium bis[(trifluoromethane)sulfonyl]imide (LiNTf{sub 2}) to extract the analytes. Using a fully automatic SPE workstation, special SPE columns packed with nonwoven polypropylene (NWPP) fiber, and a modified operation program, the procedures of the IL-based in situ DLLME, including the collection of a water sample, injection of an ion exchange solvent, phase separation of the emulsified solution, elution of the retained extraction phase, and collection of the eluent into vials, can be performed automatically. The developed approach, coupled with high-performance liquid chromatography–diode array detection (HPLC–DAD), was successfully applied to the detection and concentration determination of benzoylurea (BU) insecticides in water samples. Parameters affecting the extraction performance were investigated and optimized. Under the optimized conditions, the proposed method achieved extraction recoveries of 80% to 89% for water samples. The limits of detection (LODs) of the method were in the range of 0.16–0.45 ng mL{sup −1}. The intra-column and inter-column relative standard deviations (RSDs) were <8.6%. Good linearity (r > 0.9986) was obtained over the calibration range from 2 to 500 ng mL{sup −1}. The proposed

  1. Expanding the Reach of Extension through Social Media

    Science.gov (United States)

    Gharis, Lauri W.; Bardon, Robert E.; Evans, Jennifer L.; Hubbard, William G.; Taylor, Eric

    2014-01-01

    With increasing numbers of the public using social media applications, Extension professionals have the ability to apply these same tools to connect with their clients. This article demonstrates how a social media toolset can be employed by Extension professionals by identifying how Extension professionals are currently using social media,…

  2. Use of Internet for Innovation Management by Extension Agents in ...

    African Journals Online (AJOL)

    User

    agents' increases, the perception of the Internet uses for innovation management also increases in the same direction. The extension agent that uses Internet extensively is likely to have a favourable perception of its use in innovation management. Therefore, it is important to encourage extension agents in the use of.

  3. Evaluation of the agricultural extension programmes of Shell ...

    African Journals Online (AJOL)

    Evaluation of the agricultural extension programmes of Shell Petroleum Development Company in Rivers State, Nigeria. ... The effectiveness of field extension agents was limited by inadequate communication and transport facilities, non-repayment of soft loans and irregular attendance to scheduled extension meetings by ...

  4. Documentation of Extension Specialists' Involvement in Graduate Education.

    Science.gov (United States)

    Murdock, Edward C.; York, Alan C.

    1996-01-01

    Describes the changes in the roles of the Cooperative Extension Service and extension specialists affiliated with universities. Reports the results of survey research and concludes that extension specialists should actively pursue the opportunity to direct graduate students. Contains 16 references. (DDR)

  5. Stress coping strategies among agricultural extension agents in Oyo ...

    African Journals Online (AJOL)

    The study examined the coping strategies used by extension agents A total of seventy 72agricultural extension agents were randomly sampled out of 288 agricultural extension agents from the four zones (Saki, Oyo, Ogbomosho, and Ibadan) in the Oyo State Agricultural Development Programme (OYSADEP).

  6. The role of a pluralistic extension system in enhancing agriculture ...

    African Journals Online (AJOL)

    The role of a pluralistic extension system in enhancing agriculture productivity in Mozambique. ... This is unlike in the recent past when agricultural services were mainly delivered by the public sector. The 25 years ... The expansion of public extension services created new challenges for the delivering of extension services.

  7. Journal of Agricultural Extension Vol.17 (2) December, 2013 ISSN ...

    African Journals Online (AJOL)

    ONIKOYI

    Abstract. The study assessed the availability and dissemination of information to farmers using mobile phones by public extension agents in Delta state, Nigeria. Data were collected from 64 randomly selected public extension agents from the three agricultural zones in the state. Majority (98.4%) of the extension agents were ...

  8. Using Authentic Materials for Extensive Reading to Promote English Proficiency

    Science.gov (United States)

    Guo, Siao-cing

    2012-01-01

    Current literature points to the importance and benefits of extensive reading. Extensive reading provides contextualized clues for better reading comprehension (Krashen, 1982), and substantial linguistic input (Bell, 1998) needed for language development. Several studies have found a correlation between extensive reading and specific linguistic…

  9. Job burnout and coping strategies among extension agents in south ...

    African Journals Online (AJOL)

    The need to maintain a non-mineral dependent economy and daunting food import bills have been the drive for the provision of extension services, which is dependent on motivated extension work force.. Extension personnel will not stay motivated under circumstances where the risk of job burnout is high. A simple random ...

  10. Legislated Policy as the Basis for Effective Extension Delivery ...

    African Journals Online (AJOL)

    The paper compares the extension policies and programmes of Britain and Nigeria. Extension policy in Nigeria is characterized as stemming from ad hoc arrangements which are compounded by political instability and external locus of control. The United Kingdom in contrast has had focused extension policies supported ...

  11. Determinants of training needs of extension personnel of agricultural ...

    African Journals Online (AJOL)

    The dynamics experienced in agricultural practice has put extension service delivery on a new platform that requires regular updating of the extension staff knowledge for new competences, to meet the changing needs of the clientele they serve. This study therefore sought to determine the training needs of extension ...

  12. America’s Changing Urban Landscape: Positioning Extension for Success

    Directory of Open Access Journals (Sweden)

    Marie A. Ruemenapp

    2017-06-01

    Full Text Available For the Cooperative Extension Service (Extension to have a substantive urban presence and impact, it will be vital for local Extension staff, state Extension systems, and the national Extension system to understand how to position Extension for success in large metropolitan regions. To do this, Extension should examine its history of working in cities, work to overcome a number of internal barriers or challenges that are defined in Extension literature, and develop a deeper understanding of the unique and complex set of characteristics and features of urban environments. As Extension does this, it will be important for it to move forward in a manner that ensures it is relevant to local metropolitan residents while being responsive to the needs of communities statewide. It will also be imperative that Extension be recognized locally, statewide, and nationally for its work; however, Extension is not starting from scratch as it has more than a 60-year history of working in cities. Extension should learn from best practices within the numerous strong urban and suburban operational and educational models present in a number of states.

  13. Why and How Textbooks Should Encourage Extensive Reading

    Science.gov (United States)

    Brown, Dale

    2009-01-01

    Extensive reading is believed to have considerable benefits for learners both in terms of learning gains and motivation and seems to be becoming ever more popular in the ELT world. So far, however, there seems to be almost no integration of extensive reading and textbooks. This article argues that textbooks should be encouraging extensive reading,…

  14. Integrating Extensive Reading into an English for Academic Purposes Program

    Science.gov (United States)

    Macalister, John

    2008-01-01

    This paper reports on the inclusion of extensive reading in three separate 12-week courses taught by different teachers on an EAP programme at a New Zealand university. The inclusion of extensive reading was experimental and sought answers to two questions: would students respond positively to the extensive reading component, and how could…

  15. Constraints to agricultural extension work in Ethiopia: the insiders ...

    African Journals Online (AJOL)

    This paper examines principal obstacles to agricultural extension work in Ethiopia. The historical review reveals that extension programs and policies have been formulated without due consideration to the farmers' opinion, the various extension approaches have been biased against the livestock sub-sector, and research ...

  16. Evaluation of performance of extension workers in Lesotho | Mokone ...

    African Journals Online (AJOL)

    The extension service in Lesotho and other developing countries have been criticized for not being able to bring the necessary change in the farming populace, especially the rural and resource poor. Extension workers are faced with problems that need to be dealt with in order for them and extension as a whole to be ...

  17. Farmers and Extension Personnel View of Constraints to Effective ...

    African Journals Online (AJOL)

    This study examined farmers' and extension personnel's View of constraints to effectiveness of agricultural extension services in Oyo State, Nigeria. Simple random sampling technique was used to select 100 farmers and 20 extension personnel. Data subjected to descriptive and correlation analyses were collected using ...

  18. Public Sector Agricultural Extension System Reform and the Challenges Ahead

    Science.gov (United States)

    Rivera, William M.

    2011-01-01

    This paper is organized into two main sections. The first section examines extension as an engine for innovation and reviews the numerous priorities confronting extension systems. Section two highlights the current knowledge imperative and the critical connection of extension to post-secondary higher education and training, organizational…

  19. 34 CFR 101.42 - Extension of time or postponement.

    Science.gov (United States)

    2010-07-01

    ... 34 Education 1 2010-07-01 2010-07-01 false Extension of time or postponement. 101.42 Section 101.42 Education Regulations of the Offices of the Department of Education OFFICE FOR CIVIL RIGHTS... Extension of time or postponement. Requests for extension of time should be served on all parties and should...

  20. 38 CFR 18b.27 - Extension of time or postponement.

    Science.gov (United States)

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2010-07-01 2010-07-01 false Extension of time or postponement. 18b.27 Section 18b.27 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS... Time § 18b.27 Extension of time or postponement. Requests for extension of time should be served on all...

  1. evaluation of job performance of village extension agents in lagos ...

    African Journals Online (AJOL)

    AFINNI IMAM

    factors influencing dissemination of improved technology, age, education and gender were significant at 5% level of ... agricultural production and in marketing of their produce (Williams, 1989). On the other hand, ... extension agents often determines the success or failure of an extension programme. An extension agent ...

  2. Evaluating retail format extensions : The role of shopping goals

    NARCIS (Netherlands)

    Haans, A.J.

    2011-01-01

    Although retail extensions have become a common growth strategy, more than 50% fail to survive. The question what drives extension success, therefore remains a key issue. This research tests the hypothesis that expectations about the attributes of extensions, and as a result of their evaluations,

  3. Evaluation of extension agents effectiveness in transferring agro ...

    African Journals Online (AJOL)

    Evaluation of extension agents effectiveness in transferring agro-forestry technologies to farmers in Imo state, Nigeria. ... The paper recommended adequate motivation and training of the change agents to equip them more in their extension delivery. Keyword: Agroforestry technologies, conservation, extension agents, ...

  4. Facilitating protein solubility by use of peptide extensions

    Science.gov (United States)

    Freimuth, Paul I; Zhang, Yian-Biao; Howitt, Jason

    2013-09-17

    Expression vectors for expression of a protein or polypeptide of interest as a fusion product composed of the protein or polypeptide of interest fused at one terminus to a solubility enhancing peptide extension are provided. Sequences encoding the peptide extensions are provided. The invention further comprises antibodies which bind specifically to one or more of the solubility enhancing peptide extensions.

  5. Evaluation of the effectiveness of the Imo State fisheriers extension ...

    African Journals Online (AJOL)

    Evaluation of the effectiveness of the Imo State fisheriers extension programme. DO Ohajianya, DO Onu, JA Echetama. Abstract. This study evaluated the Imo State Ministry of Agriculture Fisheries Extension Programmes. Questionnaires were used to collect data from 15 randomly selected extension staff and 200 ...

  6. Perspective of agricultural extension in livestock production in ...

    African Journals Online (AJOL)

    The main source of extension services was the private sector and the services rendered were educational, health, technical, management and marketing. The extension communication methods used were visits, demonstration, workshop, training and excursion. The benefits of extension services were introduction of ...

  7. F--: A Parallel Extension to Cray Fortran

    Directory of Open Access Journals (Sweden)

    Robert W. Numrich

    1997-01-01

    Full Text Available F-- is a parallel extension to Cray Fortran 77 for distributed memory computers. It adds exactly one new symbol to the language, a vertical line that separates two sets of indices. The first set contains the coordinates for data in a local data grid. The second set contains the coordinates for processors in a global processor grid. A statement such as x(i,j=y(i,j| p,q generates a load from remote address y(i,j in the data grid on processor (p,q followed by a store to local address x(i,j in the local data grid. F-- syntax requires an explicit statement of the relationship between data layout and processor layout. It assumes that good performance on a distributed memory computer requires the programmer to understand and to exploit data locality. Programmers use the F-- syntax only when it is needed. 0therwise all data are local and all code is local. Compiler and library developers concentrate on generating well-optimized local code.

  8. Extension Large Colon Resection in 12 Horses

    Science.gov (United States)

    Arighi, Mimi; Ducharme, Norman G.; Horney, F. Donald.; Livesey, Michael A.

    1987-01-01

    Extensive resection (50-75%) of the large colon was performed in 12 horses. Indications for resection were: loss of viability due to large colon volvulus (seven), thromboembolic episode (three), impairment of flow of ingesta due to adhesions (one), or congenital abnormalities (one). The time required to correct the primary cause of abdominal pain and complete the resection ranged from 2.5 to 4.75 hours. Three horses had severe musculoskeletal problems postoperatively and were euthanized in the recovery stall. Four other horses were euthanized early in the postoperative period because of: further large colon infarction (two), ileus (one), or small intestinal problems (one). Five horses survived with no apparent nutritional or metabolic problems during two to three weeks of hospitalization. Clinical data were obtained from these horses from nine months to eighteen months postoperatively and revealed no clinical or clinicopathological abnormalities in four of them; the fifth horse exhibited diarrhea and weight loss four months postoperatively but responded to diet change. PMID:17422768

  9. Lateral Distribution Functions of Extensive Air Showers

    Science.gov (United States)

    Geranios, A.; Fokitis, E.; Maltezos, S.; Koutsokosta, D.; Antoniadou, I.; Malandraki, O.; Mastichiadis, A.; Antonopoulou, E.; Gika, V.; Dimitrakoudis, S.

    The energy is among the characteristics of Ultra High Energy Cosmic Rays (E>5 x 1019 eV) which could be estimated experimentally. The following paper attempts to estimate the energy of an UHECR proton by applying a Monte Carlo simulation code. A number of extensive air showers, vertical and inclined, is simulated to derive the Lateral Distribution Functions of the shower muons. The scenario of simulations is adopted to the Cerenkov surface detector of the P. AUGER Observatory. Due to the fact that the Lateral Distribution Functions show minimal fluctuations of the muon density at a distance larger than 800 m from the core of the showers, and due to the fact that at a distance of 900 m the distribution functions for inclined showers coincide (which means that it does not change with the zenith angle of the showers), we select the muon density at 900 m to derive the energy of the primary protons. (The project is co-funded by the European Social Fund and National Resources (EPEAEK II) PYTHAGORAS II.)

  10. Deformed Fredkin Spin Chain with Extensive Entanglement

    CERN Document Server

    Salberger, Olof; Zhang, Zhao; Katsura, Hosho; Klich, Israel; Korepin, Vladimir

    2016-01-01

    We introduce a new spin chain which is a deformation of the Fredkin spin chain and has a phase transition between bounded and extensive entanglement entropy scaling. In this chain, spins have a local interaction of three nearest neighbors. The Hamiltonian is frustration-free and its ground state can be described analytically as a weighted superposition of Dyck paths. In the purely spin $1/2$ case, the entanglement entropy obeys an area law: it is bounded from above by a constant, when the size of the block $n$ increases (and $t>1$). When a local color degree of freedom is introduced the entanglement entropy increases linearly with the size of the block (and $t>1$). The entanglement entropy of half of the chain is tightly bounded by ${ n}\\log s$ where $n$ is the size of the block, and $s$ is the number of colors. Our chain fosters a new example for a significant boost to entropy and for the existence of the associated critical rainbow phase where the entanglement entropy scales with volume that has recently be...

  11. Quaternionic (super) twistors extensions and general superspaces

    Science.gov (United States)

    Cirilo-Lombardo, Diego Julio; Pervushin, Victor N.

    2017-09-01

    In a attempt to treat a supergravity as a tensor representation, the four-dimensional N-extended quaternionic superspaces are constructed from the (diffeomorphyc) graded extension of the ordinary Penrose-twistor formulation, performed in a previous work of the authors [D. J. Cirilo-Lombardo and V. N. Pervushin, Int. J. Geom. Methods Mod. Phys., doi: http://dx.doi.org/10.1142/S0219887816501139.], with N = p + k. These quaternionic superspaces have 4 + k(N - k) even-quaternionic coordinates and 4N odd-quaternionic coordinates, where each coordinate is a quaternion composed by four ℂ-fields (bosons and fermions respectively). The fields content as the dimensionality (even and odd sectors) of these superspaces are given and exemplified by selected physical cases. In this case, the number of fields of the supergravity is determined by the number of components of the tensor representation of the four-dimensional N-extended quaternionic superspaces. The role of tensorial central charges for any N even USp(N) = Sp(N, ℍℂ) ∩ U(N, ℍℂ) is elucidated from this theoretical context.

  12. Extensive Air Showers with unusual structure

    Directory of Open Access Journals (Sweden)

    Beznosko Dmitriy

    2017-01-01

    Full Text Available A total of 23500 Extensive Air Showers (EAS with energies above ∼ 1016 eV have been detected during the ∼3500 hours of the Horizon-T (HT detectors system operations before Aug. 2016. Among these EAS, more than a thousand had an unusual spatial and temporary structure that showed pulses with several maxima (modals or modes from several detection points of the HT at the same time. These modes are separated in time from each other starting from tens to thousands of ns. These EAS have been called multi-modal. Analysis shows that the multi-modal EAS that have been detected by Horizon-T have the following properties: 1. Multi-modal EAS have energy above ∼1017 eV. 2. Pulses with several modes are located at large distances from the EAS axis. An overview of the collected data will be provided. General comments about the unusual structure of the multi-modal EAS will be presented.

  13. Computers make rig life extension an option

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-10-01

    The worldwide semisubmersible drilling rig fleet is approaching retirement. But replacement is not an attractive option even though dayrates are reaching record highs. In 1991, Schlumberger Sedco Forex managers decided that an alternative might exist if regulators and insurers could be convinced to extend rig life expectancy through restoration. Sedco Forex chose their No. 704 semisubmersible, an 18-year North Sea veteran, to test their process. The first step was to determine what required restoration, meaning fatigue life analysis of each weld on the huge vessel. If inspected, the task would be unacceptably time-consuming and of questionable accuracy. Instead a suite of computer programs modeled the stress seen by each weld, statistically estimated the sea states seen by the rig throughout its North Sea service and calibrated a beam-element model on which to run their computer simulations. The elastic stiffness of the structure and detailed stress analysis of each weld was performed with ANSYS, a commercially available finite-element analysis program. The use of computer codes to evaluate service life extension is described.

  14. Latest results of the Tunka Radio Extension

    Directory of Open Access Journals (Sweden)

    Kostunin D.

    2017-01-01

    Full Text Available The Tunka Radio Extension (Tunka-Rex is an antenna array consisting of 63 antennas at the location of the TAIGA facility (Tunka Advanced Instrument for cosmic ray physics and Gamma Astronomy in Eastern Siberia, nearby Lake Baikal. Tunka-Rex is triggered by the air-Cherenkov array Tunka-133 during clear and moonless winter nights and by the scintillator array Tunka-Grande during the remaining time. Tunka-Rex measures the radio emission from the same air-showers as Tunka-133 and Tunka-Grande, but with a higher threshold of about 100 PeV. During the first stages of its operation, Tunka-Rex has proven, that sparse radio arrays can measure air-showers with an energy resolution of better than 15% and the depth of the shower maximum with a resolution of better than 40 g/cm2. To improve and interpret our measurements as well as to study systematic uncertainties due to interaction models, we perform radio simulations with CORSIKA and CoREAS. In this overview we present the setup of Tunka-Rex, discuss the achieved results and the prospects of mass-composition studies with radio arrays.

  15. Multidrug and extensively drug-resistant tuberculosis.

    Science.gov (United States)

    Maitre, T; Aubry, A; Jarlier, V; Robert, J; Veziris, N

    2017-02-01

    The emergence of drug-resistant tuberculosis (TB) compromises global tuberculosis control. The incidence of multidrug-resistant strains (MDR) defined as resistant to the two main antituberculosis drugs, rifampicin and isoniazid, was raised in the 1990s. Ten percent of these strains have developed additional resistance to the main second-line antituberculosis drugs: fluoroquinolones and aminoglycosides. These strains are defined as extensively drug-resistant (XDR). The prognosis of MDR-TB and XDR-TB is poor due to limited therapeutic resources. However, many new innovations may lead to a radical change in this field. Genotypic testing is now able to detect drug resistance within a few hours. Genotypic diagnosis of rifampicin resistance is now recommended in France for each new case of TB. The currently recommended treatment for MDR-TB is long (18-24 months) and toxic. It is, however, on the verge of being replaced by a 9-month treatment. New antituberculosis drugs such as bedaquiline and delamanid should also improve the prognosis of MDR-TB and XDR-TB. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  16. Enzymes and other agents that enhance cell wall extensibility

    Science.gov (United States)

    Cosgrove, D. J.

    1999-01-01

    Polysaccharides and proteins are secreted to the inner surface of the growing cell wall, where they assemble into a network that is mechanically strong, yet remains extensible until the cells cease growth. This review focuses on the agents that directly or indirectly enhance the extensibility properties of growing walls. The properties of expansins, endoglucanases, and xyloglucan transglycosylases are reviewed and their postulated roles in modulating wall extensibility are evaluated. A summary model for wall extension is presented, in which expansin is a primary agent of wall extension, whereas endoglucanases, xyloglucan endotransglycosylase, and other enzymes that alter wall structure act secondarily to modulate expansin action.

  17. Seeking the boundary of boundary extension.

    Science.gov (United States)

    McDunn, Benjamin A; Siddiqui, Aisha P; Brown, James M

    2014-04-01

    Boundary extension (BE) is a remarkably consistent visual memory error in which participants remember seeing a more wide-angle image of a scene than was actually viewed (Intraub & Richardson, Journal of Experimental Psychology: Learning, Memory, and Cognition 15:179-187, 1989). Multiple stimulus factors are thought to contribute to the occurrence of BE, including object recognition, conceptual knowledge of scenes, and amodal perception at the view boundaries (Intraub, Wiley Interdisciplinary Reviews: Cognitive Science 3:117-127, 2012). In the present study, we used abstract scenes instead of images of the real world, in order to remove expectations based on semantic associations with objects and the schematic context of the view. Close-angle and wide-angle scenes were created using irregular geometric shapes rated by independent observers as lacking any easily recognizable structure. The abstract objects were tested on either a random-dot or a blank background in order to assess the influence of implied continuation of the image beyond its boundaries. The random-dot background conditions had background occlusion cues either present or absent at the image border, in order to test their influence on BE in the absence of high-level information about the scenes. The results indicate that high-level information about objects and schematic context is unnecessary for BE to occur, and that occlusion information at the image boundary also has little influence on BE. Contrary to previous studies, we also found clear BE for all conditions, despite using scenes depicting undetailed objects on a blank white background. The results highlighted the ubiquitous nature of BE and the adaptability of scene perception processes.

  18. SWOT Analysis of Extension Systems in Southern African Countries

    Directory of Open Access Journals (Sweden)

    Oladimeji Idowu Oladele

    2011-11-01

    Full Text Available This paper examined the strengths, weaknesses, opportunities and threats to extension systems in selected southern African countries of Malawi, Zambia, Swaziland, Mozambique, Lesotho and Botswana. This is predicated on the need for improved performance and reinvigoration of extension system for better services. Some of the strengths are development works to improve rural areas, extensive grassroots coverage, and use of committees for research and extension linkages, involvement of NGOs and private sector, and effective setting of extension administration units. On the other hand opportunities that can be explored are donor will fund well designed programme, expansion in the use of ICT, high involvement of farmers in extension planning, and potential for effective programme implementation. The threats to the extension systems are attempts to privatize extension services, weak feedback to research, and donor fatigue. The paper recommends that extension administrators, and policy makers should pay proper attention to the strengths, weaknesses, opportunities and threats to extension systems with a view of making extension services truly more responsive to local concerns and policy.

  19. Examining Extension's Capacity in Community Resource and Economic Development: Viewpoints of Extension Administrators on the Role of Community Resource and Economic Development in the Extension Portfolio

    Science.gov (United States)

    Urbanowitz, Seth C.; Wilcox, Michael D., Jr.

    2013-01-01

    The survey-based research reported here offers insights on community, resource, and economic development (CRED) Extension programming at the national and regional level. The results present a national picture of CRED programming, research, and potential future programming opportunities that Extension could capitalize on. The research shows that…

  20. Correlation between extension-block K-wire insertion angle and postoperative extension loss in mallet finger fracture.

    Science.gov (United States)

    Lee, S K; Kim, Y H; Moon, K H; Choy, W S

    2017-10-09

    Extension-block pinning represents a simple and reliable surgical technique. Although this procedure is commonly performed successfully, some patients develop postoperative extension loss. To date, the relationship between extension-block Kirschner wire (K-wire) insertion angle and postoperative extension loss in mallet finger fracture remains unclear. We aimed to clarify this relationship and further evaluate how various operative and non-operative factors affect postoperative extension loss after extension-block pinning for mallet finger fracture. A retrospective study was conducted to investigate a relationship between extension block K-wire insertion angle and postoperative extension loss. The inclusion criteria were: (1) a dorsal intra-articular fracture fragment involving 30% of the base of the distal phalanx with or without volar subluxation of the distal phalanx; and (2) angle and fixation angle of the distal interphalangeal (DIP) joint were assessed using lateral radiograph at immediate postoperative time. Postoperative extension loss was assessed by using lateral radiograph at latest follow-up. Extension-block K-wire insertion angle was defined as the acute angle between extension block K-wire and longitudinal axis of middle phalangeal head. DIP joint fixation angle was defined as the acute angle between the distal phalanx and middle phalanx longitudinal axes. Seventy-five patients were included. The correlation analysis revealed that extension-block K-wire insertion angle had a negative correlation with postoperative extension loss, whereas fracture size and time to operation had a positive correlation (correlation coefficient for extension block K-wire angle: -0.66, facture size: +0.67, time to operation: +0.60). When stratifying patients in terms of negative and positive fixation angle of the DIP joint, the independent t-test showed that mean postoperative extension loss is -3.67° and +4.54° (DIP joint fixation angles of angle (30°, 30°-40°, >40