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Sample records for alternative leu design

  1. An alternative LEU design for the FRM-II

    International Nuclear Information System (INIS)

    Hanan, N.A.; Mo, S.C.; Smith, R.S.; Matos, J.E.

    1997-02-01

    The Alternative LEU Design for the FRM-II proposed by the RERTR Program at Argonne National Laboratory (ANL) has a compact core consisting of a single fuel element that uses LEU silicide fuel with a uranium density of 4.5 g/cm[sup 3] and has a power level of 32 MW. Both the HEU design by the Technical University of Munich (TUM) and the alternative LEU design by ANL have the same fuel lifetime (50 days) and the same neutron flux performance (8 x 10[sup 14] n/cm[sup 2]/s in the reflector). LEU silicide fuel with 4.5 g/cm[sup 3] has been thoroughly tested and is fully-qualified, licensable, and available now for use in a high flux reactor such as the FRM-II. Computer models for the HEU and LEU designs have been exchanged between TUM and ANL and discrepancies have been resolved. The following issues are addressed: qualification of HEU and LEU silicide fuels, stability of the fuel plates, gamma heating in the heavy water reflector, a hypothetical accident involving the configuration of the reflector, a loss of primary coolant flow transient due to an interrupted power supply, the radiological consequences of larger fission product and plutonium inventories in the LEU core, and cost and schedule. Calculations were also done to address the possibility that new high density LEU fuels could be developed that would allow conversion of the TUM HEU design to LEU fuel. Based on the excellent results for the Alternative LEU Design that were obtained in these analyses, the RERTR Program concludes that all of the major technical issues regarding use of LEU fuel instead of HEU fuel in the FRM-II have been successfully resolved and that it is definitely feasible to use LEU fuel in the FRM-II without compromising the safety or performance of the facility

  2. An alternative LEU design for the FRM-II

    International Nuclear Information System (INIS)

    Hanan, N.A.; Mo, S.C.; Smith, R.S.; Matos, J.E.

    1996-01-01

    The Alternative LEU Design for the FRM-II proposed by the RERTR Program at Argonne National Laboratory (ANL) has a compact core consisting of a single fuel element that uses LEU silicide fuel with a uranium density of 4.5 g/cm 3 and has a power level of 32 MW. Both the HEU design by the Technical University of Munich (TUM) and the alternative LEU design by ANL have the same fuel lifetime (50 days) and the same neutron flux performance. LEU silicide fuel with 4.5 g/cm 3 has been thoroughly tested and is fully-qualified, licensable, and available now for use in a high flux reactor such as the FRM-II. The following issues raised by TUM were addressed in Ref. 1: qualification of HEU and LEU silicide fuels, gamma heating in the heavy water reflector, radiological consequences of larger fission product and plutonium inventories in the LEU core, and cost and schedule. The conclusions of these analyses are summarized below. This paper addresses three additional safety issues that were raised by TUM in Ref. 2: stability of the involute fuel plates, a hypothetical accident involving the configuration of the reflector, and a loss of primary coolant flow transient due to an interrupted power supply. Based on the excellent results for the Alternative LEU Design that were obtained in these analyses, the RERTR Program concludes that all of the major technical issues regarding use of LEU fuel instead of HEU fuel in the FRM-II have been successfully resolved and that it is definitely feasible to use LEU fuel in the FRM-II without compromising the safety or performance of the facility

  3. Comparison of the FRM-II HEU design with an alternative LEU design

    International Nuclear Information System (INIS)

    Mo, S.C.; Hanan, N.A.; Matos, J.E.

    2004-01-01

    The FRM-II reactor design of the Technical University of Munich has a compact core that utilizes fuel plates containing highly-enriched uranium (HEU, 93%). This paper presents an alternative core design utilizing low-enriched uranium (LEU, 3 that provides nearly the same neutron flux for experiments as the HEU design, but has a less favourable fuel cycle economy. If an LEU fuel with a uranium density of 6.0 - 6.5 g/cm 3 . were developed, the alternative design would provide the same neutron flux and use the same number of cores per year as the HEU design. The results of this study show that there are attractive possibilities for using LEU fuel instead of HEU fuel in the FRM-II. Further optimization of the LEU design and near-term availability of LEU fuel with a uranium density greater than 4.8 g/cm 3 would enhance the performance of the LEU core. The REKIR Program is ready to exchange information with the Technical University of Munich to resolve any differences that may exist and to identify design modifications that would optimize reactor performance utilizing LEU fuel. (author)

  4. Comparison of the FRM-II HEU design with an alternative LEU design. Attachment

    International Nuclear Information System (INIS)

    Hanan, N.A.; Mo, S.C.; Smith, R.S.; Matos, J.E.

    2004-01-01

    After presentation of the foregoing paper by Dr. Nelson Hanan of Argonne National Laboratory (ANL) proposing an alternative LEU core with one fuel ring and a power level of 33 MW, a presentation was made by Dr. Klaus Boning of the Technical University of Munich comparing the FRM-II HEU design with an LEU design by Tlm that had two fuel rings and a power level of 40 MW. Dr. Boning raised the following issues concerning the use of LEU fuel in FRM-H reactor designs: (1) qualification of HEU and LEU silicide fuels, (2) gamma heating in the heavy water reflector, (3) the radiological consequences of hypothetical accidents, and (4) cost and schedule. These issues are addressed in this Attachment. In his presentation, Dr. Hanan mentioned that ANL was also investigating other LEU designs. This work led to a second alternative LEU design that has the same neutron flux performance (8 x 10 14 n/cm 2 /s peak neutron flux in the reflector) and the same fuel lifetime (50 full power days) as the HEU design, but uses LEU silicide fuel with a uranium density of only 4.5 g/cm 3 . This design was achieved by using a fuel plate that has a fuel meat thickness of 0.76 mm, a cladding thickness of 0.38 mm, and a water channel gap of 2.2 mm. A comparison is shown of the main characteristics of this second alternative LEU design with those of the FRM-II HEU design. The ANL core again has one fuel ring with the same dimensions. With this LEU design, a two stage process is no longer necessary because LEU silicide fuel with a uranium density of 4.5 g/cm 3 is fully qualified, licensable, and available now for use in a high flux reactor such as the FRM-II

  5. Greenfield Alternative Study LEU-Mo Fuel Fabrication Facility

    Energy Technology Data Exchange (ETDEWEB)

    Washington Division of URS

    2008-07-01

    This report provides the initial “first look” of the design of the Greenfield Alternative of the Fuel Fabrication Capability (FFC); a facility to be built at a Greenfield DOE National Laboratory site. The FFC is designed to fabricate LEU-Mo monolithic fuel for the 5 US High Performance Research Reactors (HPRRs). This report provides a pre-conceptual design of the site, facility, process and equipment systems of the FFC; along with a preliminary hazards evaluation, risk assessment as well as the ROM cost and schedule estimate.

  6. Fluxes at experiment facilities in HEU and LEU designs for the FRM-II

    International Nuclear Information System (INIS)

    Hanan, N. A.

    1998-01-01

    An Alternative LEU Design for the FRM-II proposed by the RERTR Program at Argonne National Laboratory (ANL) has a compact core consisting of a single fuel element that uses LEU silicide fuel with a uranium density of 4.5 g/cm 3 and has a power level of 32 MW. Both the HEU design by the Technical University of Munich (TUM) and the alternative LEU design by ANL have the same fuel lifetime(50 days) and the same neutron flux performance (8 x 10 14 n/cm 2 -s in the reflector). LEU silicide fuel with 4.5 g/cm 3 has been thoroughly tested and is fully-qualified, licensable, and available now for use in a high flux reactor such as the FRM-II. Several issues that were raised by TUM have been addressed in Refs. 1-3. The conclusions of these analyses are summarized below. This paper addresses four additional issues that have been raised in several forums, including Ref 4: heat generation in the cold neutron source (CNS), the gamma and fast neutron fluxes which are components of the reactor noise in neutron scattering experiments in the experiment hall of the reactor, a fuel cycle length difference, and the reactivity worth of the beam tubes and other experiment facilities. The results show that: (a) for the same thermal neutron flux, the neutron and gamma heating in the CNS is smaller in the LEU design than in the HEU design, and cold neutron fluxes as good or better than those of the HEU design can be obtained with the LEU design; (b) the gamma and fast neutron components of the reactor noise in the experiment hall are about the same in both designs; (c) the fuel cycle length is 50 days for both designs; and (d) the absolute value of the reactivity worth of the beam tubes and other experiment facilities is smaller in the LEU design, allowing its fuel cycle length to be increased to 53 or 54 days. Based on the excellent results for the Alternative LEU Design that were obtained in all analyses, the RERTR Program reiterates its conclusion that there are no major technical

  7. Comment on the contribution of S.C. Mo, N.A. Hanan and J.E. Matos: 'Comparison of the FRM-II HEU design with an alternative LEU design'

    International Nuclear Information System (INIS)

    Boening, K.

    2004-01-01

    The results of the reference paper, which came to our attention for the first time during this RERTR Meeting, are more or less consistent with neutronic data we have obtained earlier within the FRM-II project (i.e. with own calculations and extrapolations). However, a realistic comparison of the HEU design of the FR.M-II (HEU = highly enriched uranium, 93 % U-235) with an alternative LEU design (LEU = low enriched uranium, 20 % U-235) is only possible on the basis of identical assumptions on the input parameters and has to consider more than neutronic data only. Serious scientists and experts should not confuse the politicians with academic studies touching some aspects of the full story only. The comparison has shown that the performance and reliability of the FRM-II design, which uses HEU fuel, is so advantageous that it can not - not even approximately - be met by an alternative design using LEU fuel. A change of the FRM-II design from HEU to LEU fuel with the results as shown above - i.e. less performance, higher costs, more nuclear waste and higher risk potential, and all of this with a delay of at least 5 years this could never be justified. If a future development of more advanced fuels should allow us to achieve our scientific goals at the conditions as identified above also with uranium of reduced enrichment - there would be no objection to a corresponding later conversion. Activities to realize a new neutron source in Germany go back to the late 70's with the project of a new middle flux beam reactor (MSR), which was abandoned shortly later in favour of an ambitious new spallation neutron source (SNQ). After this project also having been terminated around 1985 because of too high costs and technological risks, the hopes of the German community of neutron scientists focussed on the FRM-II. If non-technical pressure would damage this project this would equally provide irreversible damage to the large and still prospering field of neutron research in Germany

  8. Analysis of the TREAT LEU Conceptual Design

    Energy Technology Data Exchange (ETDEWEB)

    Connaway, H. M. [Argonne National Lab. (ANL), Argonne, IL (United States); Kontogeorgakos, D. C. [Argonne National Lab. (ANL), Argonne, IL (United States); Papadias, D. D. [Argonne National Lab. (ANL), Argonne, IL (United States); Brunett, A. J. [Argonne National Lab. (ANL), Argonne, IL (United States); Mo, K. [Argonne National Lab. (ANL), Argonne, IL (United States); Strons, P. S. [Argonne National Lab. (ANL), Argonne, IL (United States); Fei, T. [Argonne National Lab. (ANL), Argonne, IL (United States); Wright, A. E. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-03-01

    Analyses were performed to evaluate the performance of the low enriched uranium (LEU) conceptual design fuel for the conversion of the Transient Reactor Test Facility (TREAT) from its current highly enriched uranium (HEU) fuel. TREAT is an experimental nuclear reactor designed to produce high neutron flux transients for the testing of reactor fuels and other materials. TREAT is currently in non-operational standby, but is being restarted under the U.S. Department of Energy’s Resumption of Transient Testing Program. The conversion of TREAT is being pursued in keeping with the mission of the Department of Energy National Nuclear Security Administration’s Material Management and Minimization (M3) Reactor Conversion Program. The focus of this study was to demonstrate that the converted LEU core is capable of maintaining the performance of the existing HEU core, while continuing to operate safely. Neutronic and thermal hydraulic simulations have been performed to evaluate the performance of the LEU conceptual-design core under both steady-state and transient conditions, for both normal operation and reactivity insertion accident scenarios. In addition, ancillary safety analyses which were performed for previous LEU design concepts have been reviewed and updated as-needed, in order to evaluate if the converted LEU core will function safely with all existing facility systems. Simulations were also performed to evaluate the detailed behavior of the UO2-graphite fuel, to support future fuel manufacturing decisions regarding particle size specifications. The results of these analyses will be used in conjunction with work being performed at Idaho National Laboratory and Los Alamos National Laboratory, in order to develop the Conceptual Design Report project deliverable.

  9. Conceptual designs parameters for MURR LEU U-Mo fuel conversion design demonstration experiment. Revision 1

    International Nuclear Information System (INIS)

    Stillman, J.; Feldman, E.; Stevens, J.

    2013-01-01

    The design parameters for the conceptual design of a fuel assembly containing U-10Mo fuel foils with low-enriched uranium (LEU) for the University of Missouri Research Reactor (MURR) are described. The Design Demonstration Experiment (MURR-DDE) will use a prototypic MURR-LEU element manufactured according to the parameters specified here. Also provided are calculated performance parameters for the LEU element in the MURR, and a set of goals for the MURR-DDE related to those parameters. The conversion objectives are to develop a fuel element design that will ensure safe reactor operations, as well as maintaining existing performance. The element was designed by staff members of the Global Threat Reduction Initiative (GTRI) Reactor Conversion Program at the Argonne National Laboratory (ANL) and the MURR Facility. A set of manufacturing assumptions were provided by the Fuel Development (FD) and Fuel Fabrication Capability (FFC) pillars of the GTRI Reduced Enrichment for Research and Test Reactors (RERTR) program to reliably manufacture the fuel plates. The proposed LEU fuel element has an overall design and exterior dimensions that are similar to those of the current highly-enriched uranium (HEU) fuel elements. There are 23 fuel plates in the LEU design. The overall thickness of each plate is 44 mil, except for the exterior plate that is furthest from the center flux trap (plate 23), which is 49 mil thick. The proposed LEU fuel plates have U-10Mo monolithic fuel foils with a 235U enrichment of 19.75% varying from 9 mil to 20 mil thick, and clad with Al-6061 aluminum. A thin layer of zirconium exists between the fuel foils and the aluminum as a diffusion barrier. The thinnest nominal combined zirconium and aluminum clad thickness on each side of the fuel plates is 12 mil. The LEU U-10Mo monolithic fuel is not yet qualified as driver fuel in research reactors, but is under intense development under the auspices of the GTRI FD and FFC programs.

  10. Preliminary design study for a carbide LEU-nuclear thermal rocket

    International Nuclear Information System (INIS)

    Venneri, P.F.; Kim, Y.

    2014-01-01

    Nuclear space propulsion is a requirement for the successful exploration of the solar system. It offers the possibility of having both a high specific impulse and a relatively high thrust, allowing rapid transit times with a minimum usage of fuel. This paper proposes a nuclear thermal rocket design based on heritage NERVA rockets that makes use of Low Enriched Uranium (LEU) fuel. The Carbide LEU Nuclear Thermal Rocket (C-LEU-NTR) is designed to fulfill the rocket requirements as set forth in the NASA 2009 Mars Mission Design Reference Architecture 5.0, that is provide 25,000 lbf of thrust, operate at full power condition for at least two hours, and have a specific impulse close to 900 s. The neutronics analysis was done using MCNP5 with the ENDF/B-VII.1 neutron library. The thermal hydraulic calculations and size optimization were completed with a finite difference code being developed at the Center for Space Nuclear Research. (authors)

  11. Alternating access mechanisms of LeuT-fold transporters: trailblazing towards the promised energy landscapes.

    Science.gov (United States)

    Kazmier, Kelli; Claxton, Derek P; Mchaourab, Hassane S

    2017-08-01

    Secondary active transporters couple the uphill translocation of substrates to electrochemical ion gradients. Transporter conformational motion, generically referred to as alternating access, enables a central ligand binding site to change its orientation relative to the membrane. Here we review themes of alternating access and the transduction of ion gradient energy to power this process in the LeuT-fold class of transporters where crystallographic, computational and spectroscopic approaches have converged to yield detailed models of transport cycles. Specifically, we compare findings for the Na + -coupled amino acid transporter LeuT and the Na + -coupled hydantoin transporter Mhp1. Although these studies have illuminated multiple aspects of transporter structures and dynamics, a number of questions remain unresolved that so far hinder understanding transport mechanisms in an energy landscape perspective. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. HEU to LEU conversion and blending facility: UNH blending alternative to produce LEU oxide for disposal

    International Nuclear Information System (INIS)

    1995-09-01

    The United States Department of Energy (DOE) is examining options for the disposition of surplus weapons-usable fissile materials and storage of all weapons-usable fissile materials. Disposition is a process of use or disposal of material that results in the material being converted to a form that is substantially and inherently more proliferation-resistant than is the original form. Examining options for increasing the proliferation resistance of highly enriched uranium (HEU) is part of this effort. This report provides data to be used in the environmental impact analysis for the uranyl nitrate hexahydrate blending option to produce oxide for disposal. This the Conversion and Blending Facility (CBF) alternative will have two missions (1) convert HEU materials into HEU uranyl nitrate (UNH) and (2) blend the HEU uranyl nitrate with depleted and natural assay uranyl nitrate to produce an oxide that can be stored until an acceptable disposal approach is available. The primary emphasis of this blending operation will be to destroy the weapons capability of large, surplus stockpiles of HEU. The blended LEU product can only be made weapons capable again by the uranium enrichment process. The blended LEU will be produced as a waste suitable for storage or disposal

  13. HEU to LEU conversion and blending facility: UNH blending alternative to produce LEU oxide for disposal

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-09-01

    The United States Department of Energy (DOE) is examining options for the disposition of surplus weapons-usable fissile materials and storage of all weapons-usable fissile materials. Disposition is a process of use or disposal of material that results in the material being converted to a form that is substantially and inherently more proliferation-resistant than is the original form. Examining options for increasing the proliferation resistance of highly enriched uranium (HEU) is part of this effort. This report provides data to be used in the environmental impact analysis for the uranyl nitrate hexahydrate blending option to produce oxide for disposal. This the Conversion and Blending Facility (CBF) alternative will have two missions (1) convert HEU materials into HEU uranyl nitrate (UNH) and (2) blend the HEU uranyl nitrate with depleted and natural assay uranyl nitrate to produce an oxide that can be stored until an acceptable disposal approach is available. The primary emphasis of this blending operation will be to destroy the weapons capability of large, surplus stockpiles of HEU. The blended LEU product can only be made weapons capable again by the uranium enrichment process. The blended LEU will be produced as a waste suitable for storage or disposal.

  14. Neutronic and thermo-hydraulic design of LEU core for Japan Research Reactor 4

    International Nuclear Information System (INIS)

    Arigane, Kenji; Watanabe, Shukichi; Tsuruta, Harumichi

    1988-04-01

    As a part of the Reduced Enrichment Research and Test Reactor (RERTR) program in JAERI, the enrichment reduction for Japan Research Reactor 4 (JRR-4) is in progress. A fuel element using a 19.75 % enriched UAlx-Al dispersion type with a uranium density of 2.2 g/cm 3 was designed as the LEU fuel and the neutronic and thermo-hydraulic performances of the LEU core were compared with those of the current HEU core. The results of the neutronic design are as follows: (1) the excess reactivity of the LEU core becomes about 1 % Δk/k less, (2) the thermal neutron flux in the fuel region decreases about 25 % on the average, (3) the thermal neutron fluxes in the irradiation pipes are almost the same and (4) the core burnup lifetime becomes about 20 % longer. The thermo-hydraulic design also shows that: (1) the fuel plate surface temperature decreases about 10 deg C due to the increase of the number of fuel plates and (2) the temperature margin with respect to the ONB temperature increases. Therefore, it is confirmed that the same utilization performance as the HEU core is attainable with the LEU core. (author)

  15. Irradiation experiment conceptual design parameters for MURR LEU U-Mo fuel conversion

    International Nuclear Information System (INIS)

    Stillman, J.; Feldman, E.; Stevens, J.; Wilson, E.

    2013-03-01

    This report contains the results of reactor design and performance calculations for conversion of the University of Missouri Research Reactor (MURR) from the use of highly-enriched uranium (HEU) fuel to the use of low-enriched uranium (LEU) fuel. The analyses were performed by staff members of the Global Threat Reduction Initiative (GTRI) Reactor Conversion Program at the Argonne National Laboratory (ANL) and the MURR Facility. The core conversion to LEU is being performed with financial support from the U. S. government. In the framework of its non-proliferation policies, the international community presently aims to minimize the amount of nuclear material available that could be used for nuclear weapons. In this geopolitical context most research and test reactors, both domestic and international, have started a program of conversion to the use of LEU fuel. A new type of LEU fuel based on an alloy of uranium and molybdenum (U-Mo) is expected to allow the conversion of U.S. domestic high performance reactors like MURR. This report presents the nominal steady-state irradiation conditions of a key set of plates containing peak irradiation parameters found in MURR cores fueled with the LEU monolithic U-Mo alloy fuel with 10 wt% Mo.

  16. Performance and Fabrication Status of TREAT LEU Conversion Conceptual Design Concepts

    Energy Technology Data Exchange (ETDEWEB)

    IJ van Rooyen; SR Morrell; AE Wright; E. P Luther; K Jamison; AL Crawford; HT III Hartman

    2014-10-01

    Resumption of transient testing at the TREAT facility was approved in February 2014 to meet U.S. Department of Energy (DOE) objectives. The National Nuclear Security Administration’s Global Threat Reduction Initiative Convert Program is evaluating conversion of TREAT from its existing highly enriched uranium (HEU) core to a new core containing low enriched uranium (LEU). This paper describes briefly the initial pre-conceptual designs screening decisions with more detailed discussions on current feasibility, qualification and fabrication approaches. Feasible fabrication will be shown for a LEU fuel element assembly that can meet TREAT design, performance, and safety requirements. The statement of feasibility recognizes that further development, analysis, and testing must be completed to refine the conceptual design. Engineering challenges such as cladding oxidation, high temperature material properties, and fuel block fabrication along with neutronics performance, will be highlighted. Preliminary engineering and supply chain evaluation provided confidence that the conceptual designs can be achieved.

  17. HEU to LEU conversion and blending facility: Metal blending alternative to produce LEU oxide for disposal

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-09-01

    US DOE is examining options for disposing of surplus weapons-usable fissile materials and storage of all weapons-usable fissile materials. The nuclear material is converted to a form more proliferation- resistant than the original form. Blending HEU (highly enriched uranium) with less-enriched uranium to form LEU has been proposed as a disposition option. Five technologies are being assessed for blending HEU. This document provides data to be used in environmental impact analysis for the HEU-LEU disposition option that uses metal blending with an oxide waste product. It is divided into: mission and assumptions, conversion and blending facility descriptions, process descriptions and requirements, resource needs, employment needs, waste and emissions from plant, hazards discussion, and intersite transportation.

  18. HEU to LEU conversion and blending facility: Metal blending alternative to produce LEU oxide for disposal

    International Nuclear Information System (INIS)

    1995-09-01

    US DOE is examining options for disposing of surplus weapons-usable fissile materials and storage of all weapons-usable fissile materials. The nuclear material is converted to a form more proliferation- resistant than the original form. Blending HEU (highly enriched uranium) with less-enriched uranium to form LEU has been proposed as a disposition option. Five technologies are being assessed for blending HEU. This document provides data to be used in environmental impact analysis for the HEU-LEU disposition option that uses metal blending with an oxide waste product. It is divided into: mission and assumptions, conversion and blending facility descriptions, process descriptions and requirements, resource needs, employment needs, waste and emissions from plant, hazards discussion, and intersite transportation

  19. A neutronic feasibility study for LEU conversion of the High Flux Beam Reactor (HFBR)

    International Nuclear Information System (INIS)

    Pond, R.B.; Hanan, N.A.; Matos, J.E.

    1997-01-01

    A neutronic feasibility study for converting the High Flux Beam Reactor at Brookhaven National Laboratory from HEU to LEU fuel was performed at Argonne National Laboratory. The purpose of this study is to determine what LEU fuel density would be needed to provide fuel lifetime and neutron flux performance similar to the current HEU fuel. The results indicate that it is not possible to convert the HFBR to LEU fuel with the current reactor core configuration. To use LEU fuel, either the core needs to be reconfigured to increase the neutron thermalization or a new LEU reactor design needs to be considered. This paper presents results of reactor calculations for a reference 28-assembly HEU-fuel core configuration and for an alternative 18-assembly LEU-fuel core configuration with increased neutron thermalization. Neutronic studies show that similar in-core and ex-core neutron fluxes, and fuel cycle length can be achieved using high-density LEU fuel with about 6.1 gU/cm 3 in an altered reactor core configuration. However, hydraulic and safety analyses of the altered HFBR core configuration needs to be performed in order to establish the feasibility of this concept. (author)

  20. Nuclear Thermal Rocket Design Using LEU Tungsten Fuel

    International Nuclear Information System (INIS)

    Venneri, Paolo; Kim, Yonghee; Husemeyer, Peter and others

    2013-01-01

    This would then open the possibility for the commercial development and implementation of an NTR. The result was a design for a 114.66 kN thrust rocket engine, with an optimized specific impulse of 801 second, and a thrust-to-weight ratio 5.08. The development and analysis of the reactor was done using an integrated neutronics and thermal hydraulics code that combines MCNP5 using ENDF-B/VI cross sections with a purpose-built thermal hydraulics code. A proof of concept has been proposed for W LEU-NTR design. The current design is built upon traditional NTR design work and implements many of the proven design characteristics and materials from previous designs. Despite the current reactor design being preliminary, it already shows promise in being able to have similar, if not better performance characteristics than current and previous NTR designs. Future work will involve the flattening of radial power profile, optimization of the axial power profile, researching methods to address the full water immersion accident scenario, and further studies regarding the breeding potential in the reactor

  1. Nuclear Thermal Rocket Design Using LEU Tungsten Fuel

    Energy Technology Data Exchange (ETDEWEB)

    Venneri, Paolo; Kim, Yonghee; Husemeyer, Peter and others

    2013-10-15

    This would then open the possibility for the commercial development and implementation of an NTR. The result was a design for a 114.66 kN thrust rocket engine, with an optimized specific impulse of 801 second, and a thrust-to-weight ratio 5.08. The development and analysis of the reactor was done using an integrated neutronics and thermal hydraulics code that combines MCNP5 using ENDF-B/VI cross sections with a purpose-built thermal hydraulics code. A proof of concept has been proposed for W LEU-NTR design. The current design is built upon traditional NTR design work and implements many of the proven design characteristics and materials from previous designs. Despite the current reactor design being preliminary, it already shows promise in being able to have similar, if not better performance characteristics than current and previous NTR designs. Future work will involve the flattening of radial power profile, optimization of the axial power profile, researching methods to address the full water immersion accident scenario, and further studies regarding the breeding potential in the reactor.

  2. Followup calculations for the UVAR LEU conversion

    International Nuclear Information System (INIS)

    Rydin, R.; Hosticka, B.; Burns, T; Hubbard, T.; Mulder, R

    2004-01-01

    The UVAR reactor was successfully converted to LEU fuel in April 1994. Void coefficient measurements were made on the 4- by-4 fully-graphite-reflected LEU-1 core configuration, and an isothermal temperature coefficient measurement was made on the operational 4-by-5 partially-graphite-reflected LEU-2 core configuration. Both of these experiments have now been modeled in their critical configurations using the 3DBUM code. The LEU cores were also modeled using the Monte Carlo code MCNP in order to obtain a neutron/gamma source for BNCT filter design calculations. Advanced BNCT filters have been evaluated using both MCNP and the discrete ordinates code DORT. The results indicate that the UVAR would be an ideal source for the BNCT treatment of brain tumors. (author)

  3. Followup calculations for the UVAR LEU conversion

    International Nuclear Information System (INIS)

    Rydin, R.A.; Hosticka, B.; Burns, T.

    1995-01-01

    The UVAR reactor was successfully converted to LEU fuel in April 1994. Void coefficient measurements were made on the 4-by-4 fully-graphite-reflected LEU-1 core configuration, and an isothermal temperature coefficient measurement was made on the operational 4-by-5 partially-graphite-reflected LEU-2 core configuration. Both of these experiments have now been modeled in their critical configurations using the 3DBUM code. The LEU cores were also modeled using the Monte Carlo code MCNP in order to obtain a neutron/gamma source for BNCT filter design calculations. Advanced BNCT filters have been evaluated using both MCNP and the discrete ordinates code DORT. The results indicate that the UVAR would be an ideal source for the BNCT treatment of brain tumors

  4. Accelerating the design and testing of LEU fuel assemblies for conversion of Russian-designed research reactors outside Russia

    International Nuclear Information System (INIS)

    Matos, J.E

    2003-01-01

    This paper identifies proposed geometries and loading specifications of LEU tube-type and pin-type test assemblies that would be suitable for accelerating the conversion of Russian-designed research reactors outside of Russia if these fuels are manufactured, qualified by irradiation testing, and made commercially available in Russia. (author)

  5. RERTR progress in Mo-99 production from LEU

    Energy Technology Data Exchange (ETDEWEB)

    Vandegrift, G.F.; Conner, C.; Aase, S.; Bakel, A.; Bowers, D.; Freiberg, E.; Gelis, A.; Quigley, K.J.; Snelgrove, J.L. [Argonne National Laboratory 9700 S. Cass Avenue, Argonne, IL (United States)

    2002-07-01

    The ANL RERTR program is performing R and D supporting conversion of {sup 99}Mo production from HEU to LEU targets. Irradiation and processing of LEU targets were demonstrated at the Argentine Ezeiza Atomic Center. Target irradiation and disassembly were flawless, but the processing is not fully developed. In addition to preparing for, assisting in, and analyzing results of the demonstration, we performed other R and D related to LEU conversion: (1) designing a prototype production dissolver for digesting irradiated LEU foils in alkaline solutions and developing means to simplify digestion, (2) modifying ion-exchange columns used in the CNEA recovery and purification of {sup 99}Mo to deal with the lower volumes generated from LEU-foil digestion, (3) measuring the performance of new inorganic sorbents that outperform alumina for recovering Mo(VI) from nitric acid solutions containing high concentrations of uranium nitrate, and (4) developing means to facilitate the concentration and calcination of waste nitric-acid/LEU-nitrate solutions from {sup 99} Mo production. (author)

  6. LEU fuel cycle analyses for the Belgian BR2 Research Reactor

    International Nuclear Information System (INIS)

    Deen, J.R.; Snelgrove, J.L.

    1988-01-01

    Equilibrium fuel cycle characteristics were calculated for reference HEU and two proposed LEU fuel cycles using an 11-group diffusion-theory neutron flux solution in hexagonal-Z geometry. The diffusion theory model was benchmarked with a detailed Monte Carlo core model. The two proposed LEU fuel designs increased the 235 U loading 20% and the fuel meat volume 51%. The first LEU design used 10 B as a burnable absorber. Either proposed LEU fuel element would provide equilibrium fuel cycle characteristics similar to those of the HEU fuel cycle. Irradiation rates of Co control followers and Ir disks in the center of the core were reduced 6 ± 1% in the LEU equilibrium core compared to reference HEU core. 11 refs., 4 figs., 5 tabs

  7. Development of production of {sup 99}Mo from LEU target

    Energy Technology Data Exchange (ETDEWEB)

    Adang, H G; Mutalib, A; Lubis, H [Radioisotope Production Centre, National Atomic Energy Agency, Kawasan Puspiptek, Serpong (Indonesia); and others

    1998-10-01

    {sup 99}TC, the most popular radioisotope in nuclear medicine, is daughter of {sup 99}Mo. {sup 99}Mo is produced in research reactor by irradiating of high enriched uranium (HEU). However, in recent year, strict regulation that has been implemented by USA DOE and NPT has led to the difficulty in getting HEU. Therefore, BATAN has tried to develop the production of {sup 99}Mo by using low enriched uranium (LEU). The research involves the use of LEU in the production of {sup 99}Mo. This research was started in 1994 by joint-research between BATAN and Argonne National Laboratory USA. This program is divided into three research groups. The first group emphasizes its research on fabrication of LEU foil that is going to be irradiated. The second group studies the irradiation`s aspects and physical characteristic of irradiated LEU foils. The third group studies the radiochemical separation process of fission product {sup 99}Mo from solution of irradiated LEU foils. There are five steps that are carried out in studying of radiochemical separation of {sup 99}Mo from irradiated LEU. First is designing a dissolver that is going to be used in dissolving of LEU foil and testing its reliability. Second is dissolving LEU in the new design dissolver. Third is evaluation the modified of Cintichem`s radiochemical separation process of {sup 99}Mo from LEU. Forth is modifying the Cintichem`s radiochemical separation process of {sup 99}Mo from the solution of irradiated LEU. And fifth is using the modified of Cintichem`s radiochemical separation process for separation {sup 99}Mo from solution of irradiated LEU. The first through the forth steps of experiments were already carried out and will be reported in this workshop, whereas the fifth step of experiment is going to be conducted in February 1998. (author)

  8. Preliminary Results of Ancillary Safety Analyses Supporting TREAT LEU Conversion Activities

    Energy Technology Data Exchange (ETDEWEB)

    Brunett, A. J. [Argonne National Lab. (ANL), Argonne, IL (United States); Fei, T. [Argonne National Lab. (ANL), Argonne, IL (United States); Strons, P. S. [Argonne National Lab. (ANL), Argonne, IL (United States); Papadias, D. D. [Argonne National Lab. (ANL), Argonne, IL (United States); Hoffman, E. A. [Argonne National Lab. (ANL), Argonne, IL (United States); Kontogeorgakos, D. C. [Argonne National Lab. (ANL), Argonne, IL (United States); Connaway, H. M. [Argonne National Lab. (ANL), Argonne, IL (United States); Wright, A. E. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2015-10-01

    The Transient Reactor Test Facility (TREAT), located at Idaho National Laboratory (INL), is a test facility designed to evaluate the performance of reactor fuels and materials under transient accident conditions. The facility, an air-cooled, graphite-moderated reactor designed to utilize fuel containing high-enriched uranium (HEU), has been in non-operational standby status since 1994. Currently, in support of the missions of the Department of Energy (DOE) National Nuclear Security Administration (NNSA) Material Management and Minimization (M3) Reactor Conversion Program, a new core design is being developed for TREAT that will utilize low-enriched uranium (LEU). The primary objective of this conversion effort is to design an LEU core that is capable of meeting the performance characteristics of the existing HEU core. Minimal, if any, changes are anticipated for the supporting systems (e.g. reactor trip system, filtration/cooling system, etc.); therefore, the LEU core must also be able to function with the existing supporting systems, and must also satisfy acceptable safety limits. In support of the LEU conversion effort, a range of ancillary safety analyses are required to evaluate the LEU core operation relative to that of the existing facility. These analyses cover neutronics, shielding, and thermal hydraulic topics that have been identified as having the potential to have reduced safety margins due to conversion to LEU fuel, or are required to support the required safety analyses documentation. The majority of these ancillary tasks have been identified in [1] and [2]. The purpose of this report is to document the ancillary safety analyses that have been performed at Argonne National Laboratory during the early stages of the LEU design effort, and to describe ongoing and anticipated analyses. For all analyses presented in this report, methodologies are utilized that are consistent with, or improved from, those used in analyses for the HEU Final Safety Analysis

  9. Future U.S. supply of Mo-99 production through fission based LEU/LEU technology

    International Nuclear Information System (INIS)

    James Welsh; Bigles, C.I.; Alejandro Valderrabano

    2015-01-01

    Coqui RadioPharmaceuticals Corp. (Coqui) has the goal of establishing a medical isotope production facility for securing a continuous domestic supply of the radioisotope molybdenum-99 for U.S. citizens. Coqui will use an LEU/LEU proven and implemented open pool, light-water, 10 MW, reactor design. The facility is being designed with twin reactors for reliability an on-site hot lab chemical processing and a waste conditioning area and a possible generator producing radio-chemistry lab. Coqui identified a 25 acre site adjacent to an existing industrial park in northern central Florida. This land was gifted and transferred to Coqui by the University of Florida Foundation. We are in the process of developing licensing documents related to the facility. The construction permit application for submission to the U.S. Nuclear Regulatory Commission is currently being prepared. Submission is scheduled for mid to late 2015. Community reaction to the proposed development has been positive. We expect to create 220 permanent jobs and we have an anticipated to be operational by 2020. (author)

  10. Future U.S. supply of Mo-99 production through fission based LEU/LEU technology.

    Science.gov (United States)

    Welsh, James; Bigles, Carmen I; Valderrabano, Alejandro

    Coquí RadioPharmaceuticals Corp. (Coquí) has the goal of establishing a medical isotope production facility for securing a continuous domestic supply of the radioisotope molybdenum-99 for U.S. citizens. Coquí will use an LEU/LEU proven and implemented open pool, light-water, 10 MW, reactor design. The facility is being designed with twin reactors for reliability an on-site hot lab chemical processing and a waste conditioning area and a possible generator producing radio-chemistry lab. Coquí identified a 25 acre site adjacent to an existing industrial park in northern central Florida. This land was gifted and transferred to Coquí by the University of Florida Foundation. We are in the process of developing licensing documents related to the facility. The construction permit application for submission to the U.S. Nuclear Regulatory Commission is currently being prepared. Submission is scheduled for mid to late 2015. Community reaction to the proposed development has been positive. We expect to create 220 permanent jobs and we have an anticipated to be operational by 2020.

  11. The global threat reduction initiative and conversion of isotope production to LEU targets

    International Nuclear Information System (INIS)

    Kuperman, A. J.

    2005-01-01

    The U.S. Global Threat Reduction Initiative (GTRI) has given a decisive impetus to the RERTR program's longstanding goal of converting worldwide production of medical radioisotopes from reliance on bomb-grade, highly enriched uranium (HEU) to low-enriched uranium (LEU) unsuitable for weapons. Although the four major; isotope producers continue to resist calls for conversion, they face mounting pressure from a variety of fronts including: (1) GTRI; (2) a related, multilateral U.S. initiative to forge agreement on conversion among the states that are home to the major producers; (3) an IAEA effort to provide technical assistance that will facilitate large-scale production of medical isotopes using LEU by producers who seek to do so; (4) planned production in the United States of substantial quantities of medical isotopes using LEU; and (5) pending U.S. legislation that would prohibit the export of HEU for production of isotopes as soon as alternative, LEU-produced isotopes are available. Accordingly, it now appears inevitable that worldwide isotope production will be converted from reliance on HEU to LEU. The only remaining question is which producers will be the first to reliably deliver sizeable quantities of LEU-produced isotopes and thereby capture global market share from the others. (author)

  12. Comparison of the parameters of the IR-8 reactor with different fuel assembly designs with LEU fuel

    International Nuclear Information System (INIS)

    Vatulin, A.; Stetsky, Y.; Dobrikova, I.

    1999-01-01

    The estimation of neutron-physical, heat and hydraulic parameters of the IR-8 research reactor with low enriched uranium (LEU) fuel was performed. Two fuel assembly (FA) designs were reviewed: IRT-4M with the tubular type fuel elements and IRT-MR with the rod type fuel elements. UO 2 -Al dispersion 19.75% enrichment fuel is used in both cases. The results of the calculations were compared with main parameters of the reactor, using the current IRT-3M FA with 90% high enriched uranium (HEU) fuel. The results of these comparisons showed that during the LEU conversion of the reactor the cycle length, excess reactivity and peak power of the IRT-MR type FA are higher than for the IRT-3M type FA and IRT-4M type FA. (author)

  13. LEU fuel fabrication in Argentina

    International Nuclear Information System (INIS)

    Giorsetti, D.R.; Gomez, J.O.; Marajofsky, A.; Kohut, C.

    1985-01-01

    As an Institution, aiming to meet with its own needs, CNEA has been intensively developing reduced enriched fuel to use in its own research and test reactors. Development of the fabrication technology as well as the design, installation and operation of the manufacturing plant, have been carried out with its own funds. Irradiation and post-irradiation of test miniplates have been taking place within the framework of the RERTR program. During the last years, CNEA has developed three LEU fuel types. In the previous RERTR meetings, we presented the technological results obtained with these fuel types. This paper focuses on CNEA LEU fuel element manufacturing status and the trained personnel we can offer in design and manufacture fuel capability. CNEA has its own fuel manufacturing technology; the necessary facilities to start the fuel fabrication; qualified technicians and professionals for: fuel design and behaviour analysis; fuel manufacturing and QA; international recognition of its fuel development and manufacturing capability through its ORR miniplate irradiation; its own natural uranium and the future possibility to enrich up to 20% U 235 ; the probability to offer a competitive fuel manufacturing cost in the international market; the disposition to cooperate with all countries that wish to take part and aim to reach an self-sufficiency in their own fuel supply needs

  14. Neutronic feasibility studies for LEU conversion of the HFR Petten reactor

    International Nuclear Information System (INIS)

    Hanan, N.A.; Deen, J.R.; Matos, J.E.; Hendriks, J.A.; Thijssen, P.J.M.; Wijtsma, F.J.

    2000-01-01

    Design and safety analyses to determine an optimum LEU fuel assembly design using U 3 Si 2 -Al fuel with up to 4.8 g/cm 3 for conversion of the HFR Petten reactor were performed by the RERTR program in cooperation with the Joint Research Centre and NRG. Credibility of the calculational methods and models were established by comparing calculations with recent measurements by NRG for a core configuration set up for this purpose. This model and methodology were then used to study various LEU fissile loading and burnable poison options that would satisfy specific design criteria. (author)

  15. HEU/LEU-conversion of BER II successfully finished

    International Nuclear Information System (INIS)

    Haas, K.; Fischer, C.-O.; Krohn, H.

    2000-01-01

    The BER II (Berliner Experimental Reactor) research reactor is a swimming pool type reactor located in Berlin, Germany. The reactor operates with a thermal power of 10 MW and is primarily used to produce neutrons for neutron scattering experiments. The conversion from HEU- to LEU-fuel elements began in August, 1997. At the last RERTR Meeting 1999 in Budapest, Hungary, Hahn-Meitner-Institut (HMI) presented a 'Status Report' on the conversion of 10 HEU/LEU mixed cores. In February 2000, HMI finished the HEU/LEU-conversion. Hereby, the first pure LEU-standard-core went into operation. Our second LEU-core just ends its operation at the end of July. The third LEU-core will be built up in the beginning of August. The average burn-up rate was improved from 50 - 55% (HEU) to 60 - 65% (LEU). Therefore, only 14 elements/year are now used instead of 28/year. The following report describes our first steps in building pure LEU-cores from mixed HEU/LEU-cores, as well as our initial experience using the pure LEU-cores. (author)

  16. Innovative nuclear thermal rocket concept utilizing LEU fuel for space application

    International Nuclear Information System (INIS)

    Nam, Seung Hyun; Venneri, Paolo; Choi, Jae Young; Jeong, Yong Hoon; Chang, Soon Heung

    2015-01-01

    Space is one of the best places for humanity to turn to keep learning and exploiting. A Nuclear Thermal Rocket (NTR) is a viable and more efficient option for human space exploration than the existing Chemical Rockets (CRs) which are highly inefficient for long-term manned missions such as to Mars and its satellites. NERVA derived NTR engines have been studied for the human missions as a mainstream in the United States of America (USA). Actually, the NERVA technology has already been developed and successfully tested since 1950s. The state-of-the-art technology is based on a Hydrogen gas (H_2) cooled high temperature reactor with solid core utilizing High-Enriched Uranium (HEU) fuel to reduce heavy metal mass and to use fast or epithermal neutron spectrums enabling simple core designs. However, even though the NTR designs utilizing HEU is the best option in terms of rocket performance, they inevitably provoke nuclear proliferation obstacles on all Research and Development (R and D) activities by civilians and non-nuclear weapon states, and its eventual commercialization. To surmount the security issue to use HEU fuel for a NTR, a concept of the innovative NTR engine, Korea Advanced NUclear Thermal Engine Rocket utilizing Low-Enriched Uranium fuel (KANUTER-LEU) is presented in this paper. The design goal of KANUTER-LEU is to make use of a LEU fuel for its compact reactor, but does not sacrifice the rocket performance relative to the traditional NTRs utilizing HEU. KANUTER-LEU mainly consists of a fission reactor utilizing H_2 propellant, a propulsion system and an optional Electricity Generation System as a bimodal engine. To implement LEU fuel for the reactor, the innovative engine adopts W-UO_2 CERMET fuel to drastically increase uranium density and thermal neutron spectrum to improve neutron economy in the core. The moderator and structural material selections also consider neutronic and thermo-physical characteristics to reduce non-fission neutron loss and

  17. The conversion of NRU from HEU to LEU fuel

    International Nuclear Information System (INIS)

    Sears, D.F.; Atfield, M.D.; Kennedy, I.C.

    1990-01-01

    The program at Chalk River Nuclear Laboratories (CRNL) to develop and test low-enriched uranium fuel (LEU, 3 Si, USiAl, USi Al and U 3 Si 2 (U-3.96 wt% Si; U-3.5 wt% Si-1.5 wt% AL; U-3.2 wt%; Si-3 wt% Al; U-7.3 wt% Si, respectively). Fuel elements were fabricated with uranium loadings suitable for NRU, 3.15 gU/cm 3 , and for NRX, 4.5 gU/cm 3 , and were irradiated under normal fuel-operating conditions. Eight experimental irradiations involving 100 mini-elements and 84 full-length elements (7X12-element rods) were completed to qualify the LEU fuel and the fabrication technology. Post irradiation examinations confirmed that the performance of the LEU fuel, and that of a medium enrichment uranium (MEU, 45% U-235) alloy fuel tested as a back-up, was comparable to the HEU fuel. The uranium silicide dispersion fuel swelling was approximately linear up to burnups exceeding NRU's design terminal burnup (80 at%). NRU was partially converted to LEU fuel when the first 31 prototype fuel rods manufactured with industrial scale production equipment were installed in the reactor. The rods were loaded in NRU at a fuelling rate of about two rods per week over the period 1988 September to December. This partial LEU core (one third of a full NRU core) has allowed the reactor engineers and physicists to evaluate the bulk effects of the LEU conversion on NRU operations. As expected, the irradiation is proceeding without incident

  18. A neutronic feasibility study for LEU conversion of the SAFARI-1 reactor

    International Nuclear Information System (INIS)

    Pond, R.B.; Hanan, N.A.; Matos, J.E.; Ball, G.

    2000-01-01

    A neutronic feasibility study to convert the SAFARI-1 reactor from HEU to LEU fuel was performed at Argonne National Laboratory in cooperation with NECSA. Comparisons were made of the reactor performance with the current 90% enriched HEU fuel type (UAl) and two 19.75% enriched LEU fuel types (U 3 Si 2 and U7Mo). The thermal fluxes with the LEU fuels were 3 - 9% lower than with the current HEU fuel. For the same fuel assembly design, a uranium density of approximately 4.5 g/cm 3 was required with U 3 Si 2 -Al fuel and a uranium density of about 4.6 g/cm 3 was required with U7Mo-Al fuel to match the 24.6-day cycle of the UAl-alloy fuel with 0.92 gU/cm 3 . The selection of a suitable LEU fuel and the decision to convert SAFARI-1 will be an economic matter that depends upon the fuel type, fuel assembly design, experiment performance and fuel cycle costs. (author)

  19. The University of Missouri Research Reactor HEU to LEU conversion project status

    Energy Technology Data Exchange (ETDEWEB)

    McKibben, James C; Kutikkad, Kiratadas; Foyto, Leslie P; Peters, Nickie J; Solbrekken, Gary L; Kennedy, John [University of Missouri Research Reactor, Missouri (United States); Stillman, John A; Feldman, Earl E; Tzanos, Constantine P; Stevens, John G [Argonne National Laboratory, Argonne, Illinois (United States)

    2012-03-15

    The University of Missouri Research Reactor (MURR) is one of five U.S. high performance research and test reactors that are actively collaborating with the U.S. Department of Energy (DOE) to find a suitable low-enriched uranium (LEU) fuel replacement for the currently required highly-enriched uranium (HEU) fuel. A conversion feasibility study based on U-10Mo monolithic LEU fuel was completed in 2009. It was concluded that the proposed LEU fuel assembly design, in conjunction with an increase in power level from 10 to 12 MWth, will (1) maintain safety margins during operation, (2) allow operating fuel cycle lengths to be maintained for efficient and effective use of the facility, and (3) preserve an acceptable level and spectrum of key neutron fluxes to meet the scientific mission of the facility. The MURR and Argonne National Laboratory (ANL) team is continuing to work toward realization of the conversion. The 'Preliminary Safety Analysis Report Methodologies and Scenarios for LEU Conversion of MURR' was completed in June 2011. This report documents design parameter values critical to the Fuel Development (FD), Fuel Fabrication Capability (FFC) and Hydromechanical Fuel Test Facility (HMFTF) projects. The report also provides a preliminary evaluation of safety analysis techniques and data that will be needed to complete the fuel conversion Safety Analysis Report (SAR), especially those related to the U-10Mo monolithic LEU fuel. Specific studies are underway to validate the proposed path to an LEU fuel conversion. Coupled fluid-structure simulations and experiments are being conducted to understand the hydrodynamic plate deformation risk for 0.965 mm (38 mil) thick fuel plates. Methodologies that were recently developed to answer the U.S. Nuclear Regulatory Commission (NRC) Request for Additional Information (RAI) regarding the MURR 2006 relicensing submittal will be used in the LEU conversion effort. Transition LEU fuel elements that will have a minimal impact on

  20. Production of MO-99 from LEU targets - Acid-side processing

    International Nuclear Information System (INIS)

    Conner, C.; Sedlet, J.; Wiencek, T.C.

    2000-01-01

    During 2000, additional targets of the new annular design containing low enriched uranium (LEU) foils were irradiated in the Indonesian RSG-GAS reactor. This new design significantly decreases the target fabrication cost. This irradiation allowed us to compare the irradiation performance of several batches of LEU foil. We also processed one of the irradiated foils to recover 99 Mo using a slightly modified Cintichem process. Finally, we measured some important physical properties of uranyl nitrate solutions (i.e., density and solubility), which will be useful in future efforts to further increase the amount of uranium that can be processed by the Cintichem process. (author)

  1. Core thermohydraulic design with LEU fuels for upgraded research reactor, JRR-3

    Energy Technology Data Exchange (ETDEWEB)

    Sudo, Y; Ando, H; Ikawa, H; Ohnishi, N [Department of Research Reactor Operation, Japan Atomic Energy Research Institute (JAERI), 319-11 Tokai-Mura, Ibaraki-Ken (Japan)

    1985-07-01

    This paper presents the outline of core thermohydraulic design and analysis of the research reactor, JRR-3, which is to be upgraded to a 20 MWt pool-type, light water-cooled reactor with 20% LEU plate-type fuels. The major feature of core thermohydraulics of the upgraded JRR-3 is that core flow is a downflow at the condition of normal operation, with which fuel plates are exposed to a severer condition than with an upflow in case of operational transients and accidents. The core thermo-hydraulic design was, therefore, done for the condition of normal operation so that fuel plates may have enough safety margin both against the onset of nucleate boiling not to allow the nucleate boiling anywhere in the core and against the initiation of DNB, and the safety margin for these were evaluated. The core velocity thus designed is at the optimum condition where fuel plates have the maximum margin against the onset of nucleate boiling. The core thermohydraulic characteristics were also clarified for the natural circulation cooling mode. (author)

  2. Study on Al-alloy or silicide LEU for DR3 in Denmark

    Energy Technology Data Exchange (ETDEWEB)

    Haack, Karsten [Riso National Laboratory, DK 4000 Roskilde (Germany)

    1985-07-01

    The 10 MW D{sub 2}0-moderated and -cooled research reactor DR3 has at present HEU fuel available for continued operation till early 19. This report presents the status of a feasibility study prepared for selection of the best suited candidate LEU fuel type for DR3 at a potential conversion in 1988. At the moment two alternatives are evaluated: UAl-alloy with modified geometry and U{sub 3}Si{sub 2} with unchanged geometry. A decision on the type selected for further investigation is expected late 1984. The investigation should comprise development, in- and out-of-pile--testing and licensing activities on the potential LEU option. (author)

  3. What the difference to use LEU and HEU fuel elements separately or together in a research reactor

    International Nuclear Information System (INIS)

    Kaya, S.; Uestuen, G.

    2005-01-01

    Concerning of nuclear material safety, most of the research reactors are advised to shift from HEU (high enriched-%93 U-235) to LEU (low enriched-%20 U-235) fuel elements. When LEU and HEU fuel elements are to be used together in a research reactor, some design and safety problems are encountered. According to use of the reactor, some research reactors such as MTR type may not show any considerable difference for HEU or LEU fuel elements, but the efficiency of radioisotope production generated by thermal neutron interaction may decrease about twenty-thirty percent when LEU fuel elements are used. Here, fine mesh-sized 3D neutronic analysis of TR-2 research reactor is presented to indicate the arising problem when LEU end HEU fuel elements are used together in a research reactor. Partial thermohydraulic analysis of the reactor is also given to show the betterness of the LEU fuel element design. However, there might be some points that should be noticed for safer operation of plate type fuelled research reactors. (author)

  4. HEU to LEU fuel conversion. Final report

    International Nuclear Information System (INIS)

    Mulder, R.U.

    1994-10-01

    The Nuclear Regulatory Commission issued a ruling, effective March 27, 1986, that all U.S. non-power reactors convert from HEU fuel to LEU fuel. A Reduced Enrichment for Research and Test Reactors Program was conducted by the Department of Energy at Argonne National Laboratory to coordinate the development of the high density LEU fuel and assist in the development of Safety Analysis Reports for the smaller non-power reactors. Several meetings were held at Argonne in 1987 with the non-power reactor community to discuss the conversion and to set up a conversion schedule for university reactors. EG ampersand G at Idaho was assigned the coordination of the fuel element redesigns. The fuel elements were manufactured by the Babcock ampersand Wilcox Company in Lynchburg, Virginia. The University of Virginia was awarded a grant by the DOE Idaho Operations Office in 1988 to perform safety analysis studies for the LEU conversion for its 2 MW UVAR and 100 Watt CAVALIER reactors. The University subsequently decided to shut down the CAVALIER reactor. A preliminary SAR on the UVAR, along with Technical Specification changes, was submitted to the NRC in November, 1990. An updated SAR was approved by the NRC in January, 1991. In September, 1992, representatives from the fuel manufacturer (B ampersand W) and the fuel designer (EG ampersand G, Idaho) came to the UVAR facility to observe trial fittings of new 22 plate LEU mock fuel elements. B ampersand W fabricated two non-fuel bearing elements, a regular 22 plate element and a control rod element. The elements were checked against the drawings and test fitted in the UVAR grid plate. The dimensions were acceptable and the elements fit in the grid plate with no problems. The staff made several suggestions for minor construction changes to the end pieces on the elements, which were incorporated into the final design of the actual fuel elements. Selected papers are indexed separately for inclusion in the Energy Science and Technology

  5. HEU to LEU fuel conversion. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Mulder, R.U.

    1994-10-01

    The Nuclear Regulatory Commission issued a ruling, effective March 27, 1986, that all U.S. non-power reactors convert from HEU fuel to LEU fuel. A Reduced Enrichment for Research and Test Reactors Program was conducted by the Department of Energy at Argonne National Laboratory to coordinate the development of the high density LEU fuel and assist in the development of Safety Analysis Reports for the smaller non-power reactors. Several meetings were held at Argonne in 1987 with the non-power reactor community to discuss the conversion and to set up a conversion schedule for university reactors. EG&G at Idaho was assigned the coordination of the fuel element redesigns. The fuel elements were manufactured by the Babcock & Wilcox Company in Lynchburg, Virginia. The University of Virginia was awarded a grant by the DOE Idaho Operations Office in 1988 to perform safety analysis studies for the LEU conversion for its 2 MW UVAR and 100 Watt CAVALIER reactors. The University subsequently decided to shut down the CAVALIER reactor. A preliminary SAR on the UVAR, along with Technical Specification changes, was submitted to the NRC in November, 1990. An updated SAR was approved by the NRC in January, 1991. In September, 1992, representatives from the fuel manufacturer (B&W) and the fuel designer (EG&G, Idaho) came to the UVAR facility to observe trial fittings of new 22 plate LEU mock fuel elements. B&W fabricated two non-fuel bearing elements, a regular 22 plate element and a control rod element. The elements were checked against the drawings and test fitted in the UVAR grid plate. The dimensions were acceptable and the elements fit in the grid plate with no problems. The staff made several suggestions for minor construction changes to the end pieces on the elements, which were incorporated into the final design of the actual fuel elements. Selected papers are indexed separately for inclusion in the Energy Science and Technology Database.

  6. Distinguishing Isomeric Peptides: The Unimolecular Reactivity and Structures of (LeuPro)M+ and (ProLeu)M+ (M = Alkali Metal).

    Science.gov (United States)

    Jami-Alahmadi, Yasaman; Linford, Bryan D; Fridgen, Travis D

    2016-12-29

    The unimolecular chemistries and structures of gas-phase (ProLeu)M + and (LeuPro)M + complexes when M = Li, Na, Rb, and Cs have been explored using a combination of SORI-CID, IRMPD spectroscopy, and computational methods. CID of both (LeuPro)M + and (ProLeu)M + showed identical fragmentation pathways and could not be differentiated. Two of the fragmentation routes of both peptides produced ions at the same nominal mass as (Pro)M + and (Leu)M + , respectively. For the litiated peptides, experiments revealed identical IRMPD spectra for each of the m/z 122 and 138 ions coming from both peptides. Comparison with computed IR spectra identified them as the (Pro)Li + and (Leu)Li + , and it is concluded that both zwitterionic and canonical forms of (Pro)Li + exist in the ion population from CID of both (ProLeu)Li + and (LeuPro)Li + . The two isomeric peptide complexes could be distinguished using IRMPD spectroscopy in both the fingerprint and the CH/NH/OH regions. The computed IR spectra for the lowest energy structures of each charge solvated complexes are consistent with the IRMPD spectra in both regions for all metal cation complexes. Through comparison between the experimental spectra, it was determined that in lithiated and sodiated ProLeu, metal cation is bound to both carbonyl oxygens and the amine nitrogen. In contrast, the larger metal cations are bound to the two carbonyls, while the amine nitrogen is hydrogen bonded to the amide hydrogen. In the lithiated and sodiated LeuPro complexes, the metal cation is bound to the amide carbonyl and the amine nitrogen while the amine nitrogen is hydrogen bonded to the carboxylic acid carbonyl. However, there is no hydrogen bond in the rubidiated and cesiated complexes; the metal cation is bound to both carbonyl oxygens and the amine nitrogen. Details of the position of the carboxylic acid C═O stretch were especially informative in the spectroscopic confirmation of the lowest energy computed structures.

  7. LEU WWR-M2 fuel assemblies burnable test

    International Nuclear Information System (INIS)

    Kirsanov, G.A.; Konoplev, K.A.; Pikulik, R.G.; Sajkov, Yu. P.; Tchmshkyan, D.V.; Tedoradze, L.V.; Zakharov, A.S.

    2000-01-01

    The results of in-pile irradiation tests of LEU WWR-M2 fuel assemblies with reduced enrichment of fuel are submitted in the report. The tests are made according to the Russian Program on Reduced Enrichment for Research and Test Reactors (RERTR). United States Department of Energy and the Ministry of Atomic Energy of Russian Federation jointly fund this Program. The irradiation tests of 5 WWR-M2 experimental assemblies are carried out at WWR-M reactor of the Petersburg Nuclear Physics Institute (PNPI). The information on assembly design and technique of irradiation tests is presented. In the irradiation tests the integrity of fuel assemblies is periodically measured. The report presents the data for the integrity maintained during the burnup of 5 fuel assemblies up to 45%. These results demonstrate the high reliability of the experimental fuel assemblies within the guaranteed burnup limits specified by the manufacturer. The tests are still in progress; it is planned to test and analyze the change in integrity for burnup of up to 70% - 75% or more. LEU WWR-M2 fuel assemblies are to be offered for export by their Novosibirsk manufacturer. Currently, HEU WWR-M2 fuel assemblies are used in Hungary, Ukraine and Vietnam. LEU WWR-M2 fuel assemblies were designed as a possible replacement for the HEU WWR-M2 fuel assemblies in those countries, but their use can be extended to other research reactors. (author)

  8. Status of core conversion with LEU silicide fuel in JRR-4

    Energy Technology Data Exchange (ETDEWEB)

    Nakajima, Teruo; Ohnishi, Nobuaki; Shirai, Eiji [Japan Atomic Energy Research Institute, Ibaraki-ken (Japan)

    1997-08-01

    Japan Research Reactor No.4 (JRR-4) is a light water moderated and cooled, 93% enriched uranium ETR-type fuel used and swimming pool type reactor with thermal output of 3.5MW. Since the first criticality was achieved on January 28, 1965, JRR-4 has been used for shielding experiments, radioisotope production, neutron activation analyses, training for reactor engineers and so on for about 30 years. Within the framework of the RERTR Program, the works for conversion to LEU fuel are now under way, and neutronic and thermal-hydraulic calculations emphasizing on safety and performance aspects are being carried out. The design and evaluation for the core conversion are based on the Guides for Safety Design and Evaluation of research and testing reactor facilities in Japan. These results show that the JRR-4 will be able to convert to use LEU fuel without any major design change of core and size of fuel element. LEU silicide fuel (19.75%) will be used and maximum neutron flux in irradiation hole would be slightly decreased from present neutron flux value of 7x10{sup 13}(n/cm{sup 2}/s). The conversion works are scheduled to complete in 1998, including with upgrade of the reactor building and utilization facilities.

  9. Status of core conversion with LEU silicide fuel in JRR-4

    International Nuclear Information System (INIS)

    Nakajima, Teruo; Ohnishi, Nobuaki; Shirai, Eiji

    1997-01-01

    Japan Research Reactor No.4 (JRR-4) is a light water moderated and cooled, 93% enriched uranium ETR-type fuel used and swimming pool type reactor with thermal output of 3.5MW. Since the first criticality was achieved on January 28, 1965, JRR-4 has been used for shielding experiments, radioisotope production, neutron activation analyses, training for reactor engineers and so on for about 30 years. Within the framework of the RERTR Program, the works for conversion to LEU fuel are now under way, and neutronic and thermal-hydraulic calculations emphasizing on safety and performance aspects are being carried out. The design and evaluation for the core conversion are based on the Guides for Safety Design and Evaluation of research and testing reactor facilities in Japan. These results show that the JRR-4 will be able to convert to use LEU fuel without any major design change of core and size of fuel element. LEU silicide fuel (19.75%) will be used and maximum neutron flux in irradiation hole would be slightly decreased from present neutron flux value of 7x10 13 (n/cm 2 /s). The conversion works are scheduled to complete in 1998, including with upgrade of the reactor building and utilization facilities

  10. Thermal hydraulic analysis of the JMTR improved LEU-core

    Energy Technology Data Exchange (ETDEWEB)

    Tabata, Toshio; Nagao, Yoshiharu; Komukai, Bunsaku; Naka, Michihiro; Fujiki, Kazuo [Japan Atomic Energy Research Inst., Oarai, Ibaraki (Japan). Oarai Research Establishment; Takeda, Takashi [Radioactive Waste Management and Nuclear Facility Decommissioning Technology Center, Tokai, Ibaraki (Japan)

    2003-01-01

    After the investigation of the new core arrangement for the JMTR reactor in order to enhance the fuel burn-up and consequently extend the operation period, the ''improved LEU core'' that utilized 2 additional fuel elements instead of formerly installed reflector elements, was adopted. This report describes the results of the thermal-hydraulic analysis of the improved LEU core as a part of safety analysis for the licensing. The analysis covers steady state, abnormal operational transients and accidents, which were described in the annexes of the licensing documents as design bases events. Calculation conditions for the computer codes were conservatively determined based on the neutronic analysis results and others. The results of the analysis, that revealed the safety criteria were satisfied on the fuel temperature, DNBR and primary coolant temperature, were used in the licensing. The operation license of the JMTR with the improved LEU core was granted in March 2001, and the reactor operation with new core started in November 2001 as 142nd operation cycle. (author)

  11. Fuel cycle flexibility in Advanced Heavy Water Reactor (AHWR) with the use of Th-LEU fuel

    International Nuclear Information System (INIS)

    Thakur, A.; Singh, B.; Pushpam, N.P.; Bharti, V.; Kannan, U.; Krishnani, P.D.; Sinha, R.K.

    2011-01-01

    The Advanced Heavy Water Reactor (AHWR) is being designed for large scale commercial utilization of thorium (Th) and integrated technological demonstration of the thorium cycle in India. The AHWR is a 920 MW(th), vertical pressure tube type cooled by boiling light water and moderated by heavy water. Heat removal through natural circulation and on-line fuelling are some of the salient features of AHWR design. The physics design of AHWR offers considerable flexibility to accommodate different kinds of fuel cycles. Our recent efforts have been directed towards a case study for the use of Th-LEU fuel cycle in a once-through mode. The discharged Uranium from Th-LEU cycle has proliferation resistant characteristics. This paper gives the initial core, fuel cycle characteristics and online refueling strategy of Th-LEU fuel in AHWR. (author)

  12. Application of the successive linear programming technique to the optimum design of a high flux reactor using LEU fuel

    International Nuclear Information System (INIS)

    Mo, S.C.

    1991-01-01

    The successive linear programming technique is applied to obtain the optimum thermal flux in the reflector region of a high flux reactor using LEU fuel. The design variables are the reactor power, core radius and coolant channel thickness. The constraints are the cycle length, average heat flux and peak/average power density ratio. The characteristics of the optimum solutions with various constraints are discussed

  13. LEU fuel powder technology at Babcock and Wilcox (USA)

    International Nuclear Information System (INIS)

    Bogacik, K.E.

    1984-01-01

    This paper traces BandW involvement in HEU fuel manufacturing to the current work directed at LEU reactor technology. Past work at BandW in areas such as alloying, fuel handling and core manufacturing has been of significant benefit to the current LEU fuel processing requirements. Recent investigations and process developments for production of LEU aluminide and silicide fuels are discussed. Techniques for alloying by vacuum are melting, followed by comminution methods after alloying, are presented for both the LEU aluminide and silicide fuel powders. Powder processing discussions include compacting techniques used by BandW for these alloys. This overview of BandW's LEU i nvolvement provides details of specific modifications and process developments in powdered fuels. Product attributes such as powder chemistry, size, and other physical properties of each LEU fuel are presented. (author)

  14. Preliminary Evaluation of Alternate Designs for HFIR Low-Enriched Uranium Fuel

    Energy Technology Data Exchange (ETDEWEB)

    Renfro, David [ORNL; Chandler, David [ORNL; Cook, David [ORNL; Ilas, Germina [ORNL; Jain, Prashant [ORNL; Valentine, Jennifer [ORNL

    2014-10-30

    Engineering design studies of the feasibility of conversion of the High Flux Isotope Reactor (HFIR) from high-enriched uranium (HEU) to low-enriched uranium (LEU) fuel are ongoing at Oak Ridge National Laboratory (ORNL) as part of an effort sponsored by the U.S. Department of Energy’s Global Threat Reduction Initiative (GTRI)/Reduced Enrichment for Research and Test Reactors (RERTR) program. The fuel type selected by the program for the conversion of the five high-power research reactors in the U.S. that still use HEU fuel is a new U-Mo monolithic fuel. Studies by ORNL have previously indicated that HFIR can be successfully converted using the new fuel provided (1) the reactor power can be increased from 85 MW to 100 MW and (2) the fuel can be fabricated to a specific reference design. Fabrication techniques for the new fuel are under development by the program but are still immature, especially for the “complex” aspects of the HFIR fuel design. In FY 2012, the program underwent a major shift in focus to emphasize developing and qualifying processes for the fabrication of reliable and affordable LEU fuel. In support of this new focus and in an effort to ensure that the HFIR fuel design is as suitable for reliable fabrication as possible, ORNL undertook the present study to propose and evaluate several alternative design features. These features include (1) eliminating the fuel zone axial contouring in the previous reference design by substituting a permanent neutron absorber in the lower unfueled region of all of the fuel plates, (2) relocating the burnable neutron absorber from the fuel plates of the inner fuel element to the side plates of the inner fuel element (the fuel plates of the outer fuel element do not contain a burnable absorber), (3) relocating the fuel zone inside the fuel plate to be centered on the centerline of the depth of the plate, and (4) reshaping the radial contour of the relocated fuel zone to be symmetric about this centerline. The

  15. Preliminary Evaluation of Alternate Designs for HFIR Low-Enriched Uranium Fuel

    Energy Technology Data Exchange (ETDEWEB)

    Renfro, David G [ORNL; Chandler, David [ORNL; Cook, David Howard [ORNL; Ilas, Germina [ORNL; Jain, Prashant K [ORNL; Valentine, Jennifer R [ORNL

    2014-11-01

    Engineering design studies of the feasibility of conversion of the High Flux Isotope Reactor (HFIR) from high-enriched uranium (HEU) to low-enriched uranium (LEU) fuel are ongoing at Oak Ridge National Laboratory (ORNL) as part of an effort sponsored by the U.S. Department of Energy s Global Threat Reduction Initiative (GTRI)/Reduced Enrichment for Research and Test Reactors (RERTR) program. The fuel type selected by the program for the conversion of the five high-power research reactors in the U.S. that still use HEU fuel is a new U-Mo monolithic fuel. Studies by ORNL have previously indicated that HFIR can be successfully converted using the new fuel provided (1) the reactor power can be increased from 85 MW to 100 MW and (2) the fuel can be fabricated to a specific reference design. Fabrication techniques for the new fuel are under development by the program but are still immature, especially for the complex aspects of the HFIR fuel design. In FY 2012, the program underwent a major shift in focus to emphasize developing and qualifying processes for the fabrication of reliable and affordable LEU fuel. In support of this new focus and in an effort to ensure that the HFIR fuel design is as suitable for reliable fabrication as possible, ORNL undertook the present study to propose and evaluate several alternative design features. These features include (1) eliminating the fuel zone axial contouring in the previous reference design by substituting a permanent neutron absorber in the lower unfueled region of all of the fuel plates, (2) relocating the burnable neutron absorber from the fuel plates of the inner fuel element to the side plates of the inner fuel element (the fuel plates of the outer fuel element do not contain a burnable absorber), (3) relocating the fuel zone inside the fuel plate to be centered on the centerline of the depth of the plate, and (4) reshaping the radial contour of the relocated fuel zone to be symmetric about this centerline. The present

  16. ANL progress in developing an LEU target and process for Mo-99 production: Cooperation with CNEA

    International Nuclear Information System (INIS)

    Gelis, A.V.; Vandegrift, G.F.; Aase, S.B.; Bakel, A.J.; Falkenberg, J.R.; Regalbuto, M.C.; Quigley, K.J.

    2003-01-01

    The primary mission of the Reduced Enrichment in Research and Test Reactors (RERTR) Program is to facilitate the conversion of research and test-reactor fuel and targets from high-enriched uranium (HEU) to low-enriched uranium (LEU). One of the current goals at Argonne National Laboratory (ANL) is to assist the Argentine Comision Nacional de Energia Atomica (CNEA) in developing an LEU foil target and a process for 99 Mo production. Specifically addressed in this paper is ANL R and D related to this conversion: (1) designing a prototype production vessel for digesting irradiated LEU foils in alkaline solutions and (2) developing a new digestion method to address all issues related to HEU to LEU conversion. (author)

  17. Neutronic design of a LEU [low enriched uranium] core for the Ohio State University research reactor

    International Nuclear Information System (INIS)

    Seshadri, M.D.; Aybar, H.S.; Aldemir, T.

    1987-01-01

    The 10 kw HEU fuelled Ohio State University Reactor (OSURR) will be upgraded to operate at 500 kW with standardized 125 g 235 U LEU U 3 Si 2 fuel plates. An earlier scoping study based on two-dimensional diffusion calculations has identified the potential LEU core configurations for the conversion/upgrade of OSURR using the standardized plates in a 16-plate (+ 2 dummy plates) standard and 10-scoping study is improved for a more precise determination of the excess reactivities and safety rod worths for these potential configurations. Comparison of the results obtained by the improved model to experimental results and to the results of full-core Monte Carlo simulations shows excellent agreement. The results also indicate that the conversion/upgrade of OSURR can be realized with three possible LEU core configurations while maintaining a cold, clean shutdown margin of 1.57-1.91 % Δ k/k, depending on the configuration used. (Author)

  18. Status of HEU-LEU conversion of FRJ-2

    International Nuclear Information System (INIS)

    Damm, G.; Nabbi, R.

    2002-01-01

    The operator of the German FRJ-2 research reactor, 'Research Center Juelich', has participated from the beginning in the RERTR programme and made comprehensive contributions to the test and use of LEU fuel for HEU-LEU-conversion measures. The originally planned time scale for the conversion of FRJ-2 was significantly delayed because of a change of the manufacturer of the LEU fuel elements and a 4 years shutdown of the reactor for refurbishment purposes. In the meantime the new LEU fuel elements are qualified and tested in the reactor. In the moment calculations for the safety report are made and it is planned to apply for the license of FRJ-2 operation with LEU fuel at the beginning of 2003. In order to get most reliable results a sophisticated computational method based on a MCNP model coupled with the depletion code BURN was developed for reactor physical calculations, core conversion studies and fuel element performance analysis and applied to the mixed and LEU core. The licensing schedule and results of latest calculations for the conversion study will be presented. The simulations shows that the thermal flux in the LEU core is about 19% resulting in a lower burnup rate. But in the reflector area around the core and in the center of the cold n source the neutron flux reduction remains limited to 6%. Due to a harder neutron spectrum in the LEU core the kinetic and safety related parameters are slightly reduced. Using the ORIGEN code it could be shown that the increase of the total fission products inventory amounts to about 6% compared to a HEU core. As a consequence of the high amount of U-238, the amount of U-235 in the LEU core has to be about 27% higher than in the HEU core but the U-235 burnup is approx. 5% lower due to the contribution of fissile plutonium. (author)

  19. Reprocessing of LEU silicide fuel at Dounreay

    International Nuclear Information System (INIS)

    Cartwright, P.

    1996-01-01

    UKAEA have recently reprocessed two LEU silicide fuel elements in their MTR fuel reprocessing plant at Dounreay. The reprocessing was undertaken to demonstrate UKAEA's commitment to the world-wide research reactor communities future needs. Reprocessing of LEU silicide fuel is seen as a waste treatment process, resulting in the production of a liquid feed suitable for conditioning in a stable form of disposal. The uranium product from the reprocessing can be used as a blending feed with the HEU to produce LEU for use in the MTR cycle. (author)

  20. Preliminary Thermohydraulic Analysis of a New Moderated Reactor Utilizing an LEU-Fuel for Space Nuclear Thermal Propulsion

    International Nuclear Information System (INIS)

    Nam, Seung Hyun; Choi, Jae Young; Venneria, Paolo F.; Jeong, Yong Hoon; Chang, Soon Heung

    2015-01-01

    The Korea Advanced NUclear Thermal Engine Rocket utilizing an LEU fuel (KANUTER-LEU) is a non-proliferative and comparably efficient NTR engine with relatively low thrust levels of 40 - 50 kN for in-space transportation. The small modular engine can expand mission versatility, when flexibly used in a clustered engine arrangement, so that it can perform various scale missions from low-thrust robotic science missions to high-thrust manned missions. In addition, the clustered engine system can enhance engine redundancy and ensuing crew safety as well as the thrust. The propulsion system is an energy conversion system to transform the thermal energy of the reactor into the kinetic energy of the propellant to produce the powers for thrust, propellant feeding and electricity. It is mainly made up of a propellant Feeding System (PFS) comprising a Turbo-Pump Assembly (TPA), a Regenerative Nozzle Assembly (RNA), etc. For this core design study, an expander cycle is assumed to be the propulsion system. The EGS converts the thermal energy of the EHTGR in the idle operation (only 350 kW th power) to electric power during the electric power mode. This paper presents a preliminary thermohydraulic design analysis to explore the design space for the new reactor and to estimate the referential engine performance. The new non-proliferative NTR engine concept, KANUTER-LEU, is under designing to surmount the nuclear proliferation obstacles on allR and Dactivities and eventual commercialization for future generations. To efficiently implement a heavy LEU fuel for the NTR engine, its reactor design innovatively possesses the key characteristics of the high U density fuel with high heating and H 2 corrosion resistances, the thermal neutron spectrum core and also minimizing non-fission neutron loss, and the compact reactor design with protectively cooling capability. To investigate feasible design space for the moderated EHTGR-LEU and resultant engine performance, the preliminary design

  1. Development of LEU targets for 99Mo production and their chemical processing status 1989

    International Nuclear Information System (INIS)

    Vandegrift, G.F.; Kwok, J.D.; Chamberlain, D.B.; Hoh, J.C.; Streets, E.W.; Vogler, S.; Thresh, H.R.; Domagala, R.F.; Wiencek, T.C.; Matos, J.E.

    1991-01-01

    Most of the world's supply of Tc-99m for medical purposes is currently produced from Mo-99 derived from the fissioning of high enriched uranium (HEU). Substitution of low enriched uranium (LEU) silicide fuel for the HEU alloy and aluminide fuels used in current target designs will allow equivalent Mo-99 yields with no change in target geometries. Substitution of uranium metal will also allow the substitution of LEU for HEU. Efforts performed in 1989 focused on (1) fabrication of a uranium metal target by Hot Isostatic Pressing uranium metal foil to zirconium, (2) experimental investigation of the dissolution step for U 3 Si 2 targets, allowing us to present a conceptual design for the dissolution process and equipment, and (3) investigation of the procedures used to reclaim irradiated uranium from Mo-production targets, allowing us to further analyze the waste and by-product problems associated with the substitution of LEU for HEU. (orig.)

  2. ANL progress in developing a target and process for converting CNEA Mo-99 production to LEU

    International Nuclear Information System (INIS)

    Vandegrift, G.F.; Gelis, A.; Aase, S.; Bakel, A.; Freiberg, E.; Conner, C.

    2002-01-01

    The primary mission of the Reduced Enrichment in Research and Test Reactors (RERTR) Program is to facilitate the conversion of research and test reactor fuel and targets from high-enriched uranium (HEU) to low-enriched uranium (LEU). One of the current goals at Argonne National Laboratory (ANL) is to convert 99 Mo production at Argentine Commission Nacional de Energia Atomica (CNEA) from HEU to LEU targets. Specifically addressed in this paper is ANL R and D related to this conversion: (1) designing a prototype production vessel for digesting irradiated LEU foils in alkaline solutions, (2) developing means to improve digestion efficiency, and (3) modifying ion-exchange processes used in the CNEA recovery and purification of 99 Mo to deal with the lower volumes generated from LEU-foil digestion. (author)

  3. A neutronics study of LEU fuel options for the HFR-Petten

    International Nuclear Information System (INIS)

    Deen, J.R.; Snelgrove, J.L.

    1985-01-01

    The standard HEU fuel cycle characteristics are compared with those of several different LEU fuel cycles in the new vessel configuration. The primary design goals were to provide similar reactivity performance and neutron flux profiles with a minimal increase in 235 U loading. The fuel cycle advantages of Cd burnable absorbers over 10 B are presented. The LEU fuel cycle requirements were calculated also for an extended 32-day cycle and for a reload batch size reduction from six to five standard elements for the standard 26-day cycle. The effects of typical in-core experiments upon neutron flux profiles and fuel loading requirements are also presented. (author)

  4. No association of the neuropeptide Y (Leu7Pro) and ghrelin gene (Arg51Gln, Leu72Met, Gln90Leu) single nucleotide polymorphisms with eating disorders.

    Science.gov (United States)

    Kindler, Jochen; Bailer, Ursula; de Zwaan, Martina; Fuchs, Karoline; Leisch, Friedrich; Grün, Bettina; Strnad, Alexandra; Stojanovic, Mirjana; Windisch, Julia; Lennkh-Wolfsberg, Claudia; El-Giamal, Nadja; Sieghart, Werner; Kasper, Siegfried; Aschauer, Harald

    2011-06-01

    Genetic factors likely contribute to the biological vulnerability of eating disorders. Case-control association study on one neuropeptide Y gene (Leu7Pro) polymorphism and three ghrelin gene (Arg51Gln, Leu72Met and Gln90Leu) polymorphisms. 114 eating disorder patients (46 with anorexia nervosa, 30 with bulimia nervosa, 38 with binge eating disorder) and 164 healthy controls were genotyped. No differences were detected between patients and controls for any of the four polymorphisms in allele frequency and genotype distribution (P > 0.05). Allele frequencies and genotypes had no significant influence on body mass index (P > 0.05) in eating disorder patients. Positive findings of former case-control studies of associations between ghrelin gene polymorphisms and eating disorders could not be replicated. Neuropeptide Y gene polymorphisms have not been investigated in eating disorders before.

  5. Peptide (Lys-Leu) and amino acids (Lys and Leu) supplementations improve physiological activity and fermentation performance of brewer's yeast during very high-gravity (VHG) wort fermentation.

    Science.gov (United States)

    Yang, Huirong; Zong, Xuyan; Cui, Chun; Mu, Lixia; Zhao, Haifeng

    2017-12-22

    Lys and Leu were generally considered as the key amino acids for brewer's yeast during beer brewing. In the present study, peptide Lys-Leu and a free amino acid (FAA) mixture of Lys and Leu (Lys + Leu) were supplemented in 24 °P wort to examine their effects on physiological activity and fermentation performance of brewer's yeast during very high-gravity (VHG) wort fermentation. Results showed that although both peptide Lys-Leu and their FAA mixture supplementations could increase the growth and viability, intracellular trehalose and glycerol content, wort fermentability, and ethanol content for brewer's yeast during VHG wort fermentation, and peptide was better than their FAA mixture at promoting growth and fermentation for brewer's yeast when the same dose was kept. Moreover, peptide Lys-Leu supplementation significantly increased the assimilation of Asp, but decreased the assimilation of Gly, Ala, Val, (Cys)2, Ile, Leu, Tyr, Phe, Lys, Arg, and Pro. However, the FAA mixture supplementation only promoted the assimilation of Lys and Leu, while reduced the absorption of total amino acids to a greater extent. Thus, the peptide Lys-Leu was more effective than their FAA mixture on the improvement of physiological activity, fermentation performance, and nitrogen metabolism of brewer's yeast during VHG wort fermentation. © 2017 International Union of Biochemistry and Molecular Biology, Inc.

  6. Preliminary Thermohydraulic Analysis of a New Moderated Reactor Utilizing an LEU-Fuel for Space Nuclear Thermal Propulsion

    Energy Technology Data Exchange (ETDEWEB)

    Nam, Seung Hyun; Choi, Jae Young; Venneria, Paolo F.; Jeong, Yong Hoon; Chang, Soon Heung [KAIST, Daejeon (Korea, Republic of)

    2015-10-15

    The Korea Advanced NUclear Thermal Engine Rocket utilizing an LEU fuel (KANUTER-LEU) is a non-proliferative and comparably efficient NTR engine with relatively low thrust levels of 40 - 50 kN for in-space transportation. The small modular engine can expand mission versatility, when flexibly used in a clustered engine arrangement, so that it can perform various scale missions from low-thrust robotic science missions to high-thrust manned missions. In addition, the clustered engine system can enhance engine redundancy and ensuing crew safety as well as the thrust. The propulsion system is an energy conversion system to transform the thermal energy of the reactor into the kinetic energy of the propellant to produce the powers for thrust, propellant feeding and electricity. It is mainly made up of a propellant Feeding System (PFS) comprising a Turbo-Pump Assembly (TPA), a Regenerative Nozzle Assembly (RNA), etc. For this core design study, an expander cycle is assumed to be the propulsion system. The EGS converts the thermal energy of the EHTGR in the idle operation (only 350 kW{sub th} power) to electric power during the electric power mode. This paper presents a preliminary thermohydraulic design analysis to explore the design space for the new reactor and to estimate the referential engine performance. The new non-proliferative NTR engine concept, KANUTER-LEU, is under designing to surmount the nuclear proliferation obstacles on allR and Dactivities and eventual commercialization for future generations. To efficiently implement a heavy LEU fuel for the NTR engine, its reactor design innovatively possesses the key characteristics of the high U density fuel with high heating and H{sub 2} corrosion resistances, the thermal neutron spectrum core and also minimizing non-fission neutron loss, and the compact reactor design with protectively cooling capability. To investigate feasible design space for the moderated EHTGR-LEU and resultant engine performance, the

  7. Feasibility study for LEU conversion of the WWR-K reactor at the Institute of Nuclear Physics in Kazakhstan using a 5-tube fuel assembly

    International Nuclear Information System (INIS)

    Hanan, N.A.; Liaw, J.R.; Matos, J.E.

    2005-01-01

    A feasibility study by the RERTR program for possible LEU conversion of the 6 MW WWR-K reactor concludes that conversion is feasible using an LEU 5-tube Russian fuel assembly design. This 5-tube design is one of several LEU fuel assembly designs being studied (Ref. 1) for possible use in this reactor. The 5-tube assembly contains 200 g 235 U with an enrichment of 19.7% in four cylindrical inner tubes and an outer hexagonal tube with the same external dimensions as the current HEU (36%) 5-tube fuel assembly, which contains 112.5 g 235 U. The fuel meat material, LEU UO 2 -Al dispersion fuel with ∼ 2.5 g U/cm 3 , has been extensively irradiation tested in a number of reactors with uranium enrichments of 36% and 19.7%. Since the 235 U loading of the LEU assemblies is much larger than the HEU assemblies, a smaller LEU core with five rows of fuel assemblies is possible (instead of six rows of fuel assemblies in the HEU core). This smaller LEU core would consume about 60% as many fuel assemblies per year as the current HEU core and provide thermal neutron fluxes in the inner irradiation channels that are ∼ 17% larger than with the present HEU core. The current 21 day cycle length would be maintained and the average discharge burnup would be ∼ 42%. Neutron fluxes in the five outer irradiation channels would be smaller in the LEU core unless these channels can be moved closer to the LEU fuel assemblies. Results show that the smaller LEU core would meet the reactor's shutdown margin requirements and would have an adequate thermal-hydraulic safety margin to onset of nucleate boiling. (author)

  8. Synthesis of high specific active tritiated Leu-enkephalin in the leucine residue

    Energy Technology Data Exchange (ETDEWEB)

    Baba, S.; Hasegawa, H.; Shinohara, Y. (Tokyo Coll. of Pharmacy (Japan))

    1989-12-01

    Leu-enkephalin labelled with tritium in the Leu residue has been prepared. Synthesis of the precursor peptide, (4,5-dehydroLeu{sup 5}-)Leu-enkephalin, was carried out by solid phase synthesis using Fmoc amino acid derivatives. The peptide was tritiated catalytically yielding {sup 3}H-Leu-enkephalin with a specific radioactivity of 4.39 TBq/mmol. The distribution of tritium label was investigated by reversed-phase high performance liquid chromatography with a synchronized accumulating radioisotope detector following acidic and enzymatic hydrolysis, which confirmed that the tritium label was entirely located at the Leu residue. (author).

  9. Induction of CD4 suppressor T cells with anti-Leu-8 antibody

    International Nuclear Information System (INIS)

    Kanof, M.E.; Strober, W.; James, S.P.

    1987-01-01

    To characterize the conditions under which CD4 T cells suppress polyclonal immunoglobulin synthesis, we investigated the capacity of CD4 T cells that coexpress the surface antigen recognized by the monoclonal antibody anti-Leu-8 to mediate suppression. In an in vitro system devoid of CD8 T cells, CD4, Leu-8+ T cells suppressed pokeweed mitogen-induced immunoglobulin synthesis. Similarly, suppressor function was induced in unfractionated CD4 T cell populations after incubation with anti-Leu-8 antibody under cross-linking conditions. This induction of suppressor function by anti-Leu-8 antibody was not due to expansion of the CD4, Leu-8+ T cell population because CD4 T cells did not proliferate in response to anti-Leu-8 antibody. However, CD4, Leu-8+ T cell-mediated suppression was radiosensitive. Finally, CD4, Leu-8+ T cells do not inhibit immunoglobulin synthesis when T cell lymphokines were used in place of helper CD4 T cells (CD4, Leu-8- T cells), suggesting that CD4 T cell-mediated suppression occurs at the T cell level. We conclude that CD4 T cells can be induced to suppress immunoglobulin synthesis by modulation of the membrane antigen recognized by anti-Leu-8 antibody

  10. Development of Fission Mo-99 Process for LEU Dispersion Target

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seung Kon; Lee, Su Seung; Hong, Soon Bog; Jang, Kyung Duk; Park, Ul Jae; Lee, Jun Sig [KAERI, Daejeon (Korea, Republic of)

    2016-05-15

    KAERI (Korea Atomic Energy Research Institute) is developing LEU-based fission {sup 99}Mo production process which is connected to the new research reactor (Kijang New Research Reactor, KJRR), which is being constructed in Gijang, Busan, Korea. Historically, the most fission {sup 99}Mo producers have been used highly enriched uranium (HEU) targets so far. However, to reduce the use of HEU in private sector for non-proliferation, {sup 99}Mo producers are forced to convert their HEU-based process to use low enriched uranium (LEU) targets. Economic impact of a target conversion from HEU to LEU is significant. Overall cost for the production of the fission {sup 99}Mo increases significantly with the conversion of fission {sup 99}Mo targets from HEU to LEU. It is not only because the yield of LEU is only 50% of HEU, but also because radioactive waste production increases 200%. On the basis, worldwide efforts on the development of {sup 99}Mo production process that is optimized for the LEU target become an important issue. In this study, fission {sup 99}Mo process with non-irradiated LEU targets was presented except separation and purification steps. Pre- and post-irradiation tests of the fission {sup 99}Mo target will be done in 4th quarter of 2016.

  11. The whole-core LEU silicide fuel demonstration in the JMTR

    Energy Technology Data Exchange (ETDEWEB)

    Aso, Tomokazu; Akashi, Kazutomo; Nagao, Yoshiharu [Japan Atomic Energy Research Institute, Ibaraki-ken (Japan)] [and others

    1997-08-01

    The JMTR was fully converted to LEU silicide (U{sub 3}Si{sub 2}) fuel with cadmium wires as burnable absorber in January, 1994. The reduced enrichment program for the JMTR was initiated in 1979, and the conversion to MEU (enrichment ; 45%) aluminide fuel was carried out in 1986 as the first step of the program. The final goal of the program was terminated by the present LEU conversion. This paper describes the results of core physics measurement through the conversion phase from MEU fuel core to LEU fuel core. Measured excess reactivities of the LEU fuel cores are mostly in good agreement with predicted values. Reactivity effect and burnup of cadmium wires, therefore, were proved to be well predicted. Control rod worth in the LEU fuel core is mostly less than that in the MEU fuel core. Shutdown margin was verified to be within the safety limit. There is no significant difference in temperature coefficient of reactivity between the MEU and LEU fuel cores. These results verified that the JMTR was successfully and safely converted to LEU fuel. Extension of the operating cycle period was achieved and reduction of spend fuel elements is expected by using the fuel with high uranium density.

  12. Development of Fission Mo-99 Process for LEU Dispersion Target

    International Nuclear Information System (INIS)

    Lee, Seung Kon; Lee, Su Seung; Hong, Soon Bog; Jang, Kyung Duk; Park, Ul Jae; Lee, Jun Sig

    2016-01-01

    KAERI (Korea Atomic Energy Research Institute) is developing LEU-based fission 99 Mo production process which is connected to the new research reactor (Kijang New Research Reactor, KJRR), which is being constructed in Gijang, Busan, Korea. Historically, the most fission 99 Mo producers have been used highly enriched uranium (HEU) targets so far. However, to reduce the use of HEU in private sector for non-proliferation, 99 Mo producers are forced to convert their HEU-based process to use low enriched uranium (LEU) targets. Economic impact of a target conversion from HEU to LEU is significant. Overall cost for the production of the fission 99 Mo increases significantly with the conversion of fission 99 Mo targets from HEU to LEU. It is not only because the yield of LEU is only 50% of HEU, but also because radioactive waste production increases 200%. On the basis, worldwide efforts on the development of 99 Mo production process that is optimized for the LEU target become an important issue. In this study, fission 99 Mo process with non-irradiated LEU targets was presented except separation and purification steps. Pre- and post-irradiation tests of the fission 99 Mo target will be done in 4th quarter of 2016

  13. [Leu31, Pro34]neuropeptide Y

    DEFF Research Database (Denmark)

    Fuhlendorff, J; Gether, U; Aakerlund, L

    1990-01-01

    Two types of binding sites have previously been described for 36-amino acid neuropeptide Y (NPY), called Y1 and Y2 receptors. Y2 receptors can bind long C-terminal fragments of NPY-e.g., NPY-(13-36)-peptide. In contrast, Y1 receptors have until now only been characterized as NPY receptors that do...... not bind such fragments. In the present study an NPY analog is presented, [Leu31, Pro34]NPY, which in a series of human neuroblastoma cell lines and on rat PC-12 cells can displace radiolabeled NPY only from cells that express Y1 receptors and not from those expressing Y2 receptors. The radiolabeled analog......, [125I-Tyr36] monoiodo-[Leu31, Pro34]NPY, also binds specifically only to cells with Y1 receptors. The binding of this analog to Y1 receptors on human neuroblastoma cells is associated with a transient increase in cytoplasmic free calcium concentrations similar to the response observed with NPY. [Leu31...

  14. Main results and status of the development of LEU fuel for Russian research reactors

    International Nuclear Information System (INIS)

    Vatulin, A.; Morozov, A.; Suprun, V.; Dobrikova, I.

    2005-01-01

    VNIINM develops low enrichment uranium (LEU) fuel on base U-Mo alloys and a novel design of pin-type fuel elements. The development is carried out both for existing reactors, and for new advanced designs of reactors. The work is carried on the following main directions: - irradiate LEU U-Mo dispersion fuel (the uranium density up to 6,0 g/cm 3 ) in two Russian research reactors: MIR (RIAR, Dimitrovgrad) as pin type fuel mini-elements and in WWR-M (PINP, Gatchina) within full-scaled fuel assembly (FA) with pin type fuel elements; - finalize development of design and fabrication process of IRT type FA with pin type fuel elements; - develop methods of reducing of U-Mo fuel --Al matrix interaction under irradiation; - develop fabricating methods of fuel elements on base of monolithic U-Mo fuel. The paper generally reviews the results of calculation, design and technology investigations accomplished by now. (author)

  15. 31 CFR 540.308 - Low Enriched Uranium (LEU).

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Low Enriched Uranium (LEU). 540.308... OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY HIGHLY ENRICHED URANIUM (HEU) AGREEMENT ASSETS CONTROL REGULATIONS General Definitions § 540.308 Low Enriched Uranium (LEU). The term low enriched...

  16. Radiological consequence analysis with HEU and LEU fuels

    Energy Technology Data Exchange (ETDEWEB)

    Woodruff, W.L.; Warinner, D.K.; Matos, J.E.

    1984-01-01

    A model for estimating the radiological consequences from a hypothetical accident in HEU and LEU fueled research and test reactors is presented. Simple hand calculations based on fission product yield table inventories and non-site specific dispersion data may be adequate in many cases. However, more detailed inventories and site specific data on meteorological conditions and release rates and heights can result in substantial reductions in the dose estimates. LEU fuel gives essentially the same doses as HEU fuel. The plutonium buildup in the LEU fuel does not significantly increase the radiological consequences. The dose to the thyroid is the limiting dose. 10 references, 3 figures, 7 tables.

  17. Radiological consequence analysis with HEU and LEU fuels

    International Nuclear Information System (INIS)

    Woodruff, W.L.; Warinner, D.K.; Matos, J.E.

    1984-01-01

    A model for estimating the radiological consequences from a hypothetical accident in HEU and LEU fueled research and test reactors is presented. Simple hand calculations based on fission product yield table inventories and non-site specific dispersion data may be adequate in many cases. However, more detailed inventories and site specific data on meteorological conditions and release rates and heights can result in substantial reductions in the dose estimates. LEU fuel gives essentially the same doses as HEU fuel. The plutonium buildup in the LEU fuel does not significantly increase the radiological consequences. The dose to the thyroid is the limiting dose. 10 references, 3 figures, 7 tables

  18. Design of ET(B) receptor agonists: NMR spectroscopic and conformational studies of ET7-21[Leu7, Aib11, Cys(Acm)15].

    Science.gov (United States)

    Hewage, Chandralal M; Jiang, Lu; Parkinson, John A; Ramage, Robert; Sadler, Ian H

    2002-03-01

    In a previous report we have shown that the endothelin-B receptor-selective linear endothelin peptide, ET-1[Cys (Acm)1,15, Ala3, Leu7, Aib11], folds into an alpha-helical conformation in a methanol-d3/water co-solvent [Hewage et al. (1998) FEBS Lett., 425, 234-238]. To study the requirements for the structure-activity relationships, truncated analogues of this peptide were subjected to further studies. Here we report the solution conformation of ET7-21[Leu7, Aib11, Cys(Acm)15], in a methanol-d3/water co-solvent at pH 3.6, by NMR spectroscopic and molecular modelling studies. Further truncation of this short peptide results in it displaying poor agonist activity. The modelled structure shows that the peptide folds into an alpha-helical conformation between residues Lys9-His16, whereas the C-terminus prefers no fixed conformation. This truncated linear endothelin analogue is pivotal for designing endothelin-B receptor agonists.

  19. A neutronic feasibility study for LEU conversion of the IR-8 research reactor

    International Nuclear Information System (INIS)

    Deen, J.R.; Hanan, N.A.; Matos, J.E.; Egorenkov, P.M.; Nasonov, V.A.

    1998-01-01

    Equilibrium fuel cycle comparisons for the IR-8 research reactor were made for HEU (90%), HEU (36%), and LEU (19.75%) fuel assembly (FA) designs using three dimensional multi-group diffusion theory models benchmarked to detailed Monte Carlo models of the reactor. Comparisons were made of changes in reactivity, cycle length, average 235 U discharge burnup, thermal neutron flux, and control rod worths for the 90% and 36% enriched IRT-3M fuel assembly and the 19.75% enriched IRT-4M fuel assembly with the same fuel management strategy. The results of these comparisons showed that a uranium density of 3.5 g/cm 3 in the fuel meat would be required in the LEU IRT-4M fuel assembly to match the cycle length of the HEU (90%) IRT-3M FA and an LEU density of 3.7 g/cm 3 is needed to match the cycle length of the HEU (36%) IRT-3M FA. (author)

  20. Production of MO-99 from LEU targets-base-side processing

    International Nuclear Information System (INIS)

    Vandegrift, George F.; Koma, Yoshikazu; Cols, Hector; Conner, Cliff; Aase, Scott; Peter, Magdalin; Walker, David; Leonard, Ralph A.; Snelgrove, James L.

    2000-01-01

    Argonne National Laboratory (ANL) is cooperating with the Argentine Comision Nacional de Energia Atomica (CNEA) to convert their 99 Mo production process, which uses high enriched uranium (HEU), to low-enriched uranium (LEU). Progress discussed in this year's paper includes optimization of (1) the digestion of LEU foil by sodium hydroxide solution and (2) the primary recovery of molybdenum by anion exchange. Also discussed are ANL/CNEA plans for demonstrating the irradiation and digestion of LEU-foil targets and recovering 99 Mo in Argentina later this year. Our results show that, up to this point in our study, conversion of the CNEA process to LEU appears viable. (author)

  1. The ORR Whole-Core LEU Fuel Demonstration

    International Nuclear Information System (INIS)

    Bretscher, M.M.; Snelgrove, J.L.

    1990-01-01

    The ORR Whole-Core LEU Fuel Demonstration, conducted as part of the US Reduced Enrichment Research and Test Reactor Program, has been successfully completed. Using commercially-fabricated U 3 Si 2 -Al 20%-enriched fuel elements (4.8 g U/cc) and fuel followers (3.5 g U/cc), the 30-MW Oak Ridge Research Reactor was safely converted from an all-HEU core, through a series of HEU/LEU mixed transition cores, to an all-LEU core. There were no fuel element failures and average discharge burnups were measured to be as high as 50% for the standard elements and 75% for the fuel followers. Experimental results for burnup-dependent critical configurations, cycle-averaged fuel element powers, and fuel-element-averaged 235 U burnups validated predictions based on three-dimensional depletion calculations. Calculated values for plutonium production and isotopic mass ratios as functions of 235 U burnup support the corresponding measured quantities. In general, calculations for reaction rate distributions, control rod worths, prompt neutron decay constants, and isothermal temperature coefficients were found to agree with corresponding measured values. Experimentally determined critical configurations for fresh HEU and LEU cores radially reflected with water and with beryllium are well-predicted by both Monte Carlo and diffusion calculations. 17 refs

  2. Oral delivery of [D-Leu-4]-OB3 and MA-[D-Leu-4]-OB3, synthetic peptide leptin mimetics: Immunofluorescent localization in the mouse hypothalamus.

    Science.gov (United States)

    Anderson, Brian M; Jacobson, Lauren; Novakovic, Zachary M; Grasso, Patricia

    2017-06-01

    This study describes the localization of [D-Leu-4]-OB3 and MA-[D-Leu-4]-OB3, synthetic peptide leptin mimetics, in the hypothalamus of Swiss Webster and C57BL/6J wild-type mice, leptin-deficient ob/ob mice, and leptin-resistant diet-induced obese (DIO) mice. The mice were given [D-Leu-4]-OB3 or MA-[D-Leu-4]-OB3 in 0.3% dodecyl maltoside by oral gavage. Once peak serum concentrations were reached, the mice received a lethal dose of pentobarbital and were subjected to intracardiac perfusion fixation. The brains were excised, post-fixed in paraformaldehyde, and cryo-protected in sucrose. Free-floating frozen coronal sections were cut at 25-µm and processed for imaging by immunofluorescence microscopy. In all four strains of mice, dense staining was concentrated in the area of the median eminence, at the base and/or along the inner wall of the third ventricle, and in the brain parenchyma at the level of the arcuate nucleus. These results indicate that [D-Leu-4]-OB3 and MA-[D-Leu-4]-OB3 cross the blood-brain barrier and concentrate in an area of the hypothalamus known to regulate energy balance and glucose homeostasis. Most noteworthy is the localization of [D-Leu-4]-OB3 immunoreactivity within the hypothalamus of DIO mice via a conduit that is closed to leptin in this rodent model, and in most cases of human obesity. Together with our previous studies describing the effects of [D-Leu-4]-OB3 and MA-[D-Leu-4]-OB3 on energy balance, glucose regulation, and signal transduction pathway activation, these findings are consistent with a central mechanism of action for these synthetic peptide leptin mimetics, and suggest their potential usefulness in the management of leptin-resistant obesity and type 2 diabetes in humans. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Whole-core LEU fuel demonstration in the ORR

    International Nuclear Information System (INIS)

    Snelgrove, J.L.; Bretscher, M.M.; Cornella, R.J.; Hobbs, R.W.

    1985-01-01

    A whole-core demonstration of LEU fuel in the ORR is expected to begin during November 1985. Fuel elements will contain U 3 Si 2 at 4.8 Mg U/m 3 and shim rod fuel followers will contain U 3 Si 2 at 3.5 Mg U/m 3 . Fuel fabrication is underway at B and W, CERCA, and NUKEM, with shipments scheduled to commence in October. The primary objectives of the demonstration are to provide data for validation of LEU and mixed-core fuel cycle calculations and to provide a large-scale demonstration of the acceptable performance of production-line U 3 Si 2 fuel elements. It is planned to approach the full LEU core through a series of mixed cores. Measurements to be made include flux distribution, reactivity swing, control rod worths, cycle length, fuel discharge burnup, gamma heating rates, β/sub eff/l, and isothermal temperature coefficient. Measurements will also be made on fresh LEU and fresh HEU critical configurations. Preliminary safety approval has been received and the final safety assessment is being reviewed

  4. Continuing investigations for technology assessment of 99Mo production from LEU [low enriched uranium] targets

    International Nuclear Information System (INIS)

    Vandegrift, G.F.; Kwok, J.D.; Marshall, S.L.; Vissers, D.R.; Matos, J.E.

    1987-01-01

    Currently much of the world's supply of 99m Tc for medical purposes is produced from 99 Mo derived from the fissioning of high enriched uranium (HEU). This paper presents the results of our continuing studies on the effects of substituting low enriched uranium (LEU) for HEU in targets for the production of fission product 99 Mo. Improvements in the electrodeposition of thin films of uranium metal continue to increase the appeal for the substitution of LEU metal for HEU oxide films in cylindrical targets. The process is effective for targets fabricated from stainless steel or zircaloy. Included is a cost estimate for setting up the necessary equipment to electrodeposit uranium metal on cylindrical targets. Further investigations on the effect of LEU substitution on processing of these targets are also reported. Substitution of uranium silicides for the uranium-aluminium alloy or uranium aluminide dispersed fuel used in current target designs will allow the substitution of LEU for HEU in these targets with equivalent 99 Mo-yield per target and no change in target geometries. However, this substitution will require modifications in current processing steps due to 1) the insolubility of uranium silicides in alkaline solutions and 2) the presence of significant quantities of silicate in solution. Results to date suggest that substitution of LEU for HEU can be achieved. (Author)

  5. Neutronics Study on LEU Nuclear Thermal Rocket Fuel Options

    Energy Technology Data Exchange (ETDEWEB)

    Venneri, Paolo; Kim, Yong Hee [KAIST, Daejeon (Korea, Republic of); Howe, Steven [CSNR, Idaho (United States)

    2014-10-15

    This has resulted in a non-trivial simplification of the tasks needed to develop such an engine and the quick initial development of the concept. There are, however, a series of key core-design choices that are currently under scrutiny in the field that have to be resolved in order for the LEU-NTR to be fully developed. The most important of these is the choice of fuel: carbide composite or tungsten cermet. This study presents a first comparison of the two fuel types specifically in the neutronic application to the LEU-NTR, keeping in mind the unique neutronic environment and the system requirements of the system. The scope of the study itself is limited to a neutronics study of the two fuels and only a cursory overview of the material properties of the fuels themselves... The results of this study have led to two major conclusions. First of all is that the carbide composite fuel is, from a neutronics standpoint, a much better fuel. It has a low absorption cross-section, is inherently a strong moderator, is able to achieve a higher reactivity using smaller amounts of fissile material, and can potentially enable a smaller reactor. Second is that despite its neutronic difficulties (high absorption, inferior moderating abilities, and lower k-infinity values) the tungsten cermet fuel is still able to perform satisfactorily in an LEU-NTR, largely due to its ability to have an extremely high fuel loading.

  6. HEU to LEU conversion experience at the UMass-Lowell research reactor

    International Nuclear Information System (INIS)

    White, John R.; Bobek, Leo M.

    2005-01-01

    The UMass-Lowell Research Reactor (UMLRR) operated safely with high-enriched uranium (HEU) fuel for over 25 years. Having reached the end of core lifetime and due to proliferation concerns, the reactor was recently converted to low-enriched uranium silicide (LEU) fuel. The actual process for converting the UMLRR from HEU to LEU fuel covered a period of over 15 years. The conversion effort - from the initial conceptual design studies in the late 1980s to the final offsite shipment of the spent HEU fuel in August 2004 - was a unique experience for the faculty and staff of a small university research reactor. This paper gives a historical view of the process and it highlights several key milestones along the road to successful completion of this project. (author)

  7. Supply of low enriched (LEU) and highly enriched uranium (HEU) for research reactors

    International Nuclear Information System (INIS)

    Mueller, H.

    1997-01-01

    Enriched uranium for research reactors in the form of LEU /= low enriched uranium at 19.75% U-235) and HEU (= highly enriched uranium at 90 to 93% U-235) was and is - due to its high U-235 enrichment - a political fuel other than enriched uranium for power reactors. The sufficient availability of LEU and HEU is a vital question for research reactors, especially in Europe, in order to perform their peaceful research reactor programs. In the past the USA were in the Western hemisphere sole supplier of LEU and HEU. Today the USA have de facto stopped the supply of LEU and HEU, for HEU mainly due to political reasons. This paper deals, among others, with the present availability of LEU and HEU for European research reactors and touches the following topics: - historical US supplies, - influence of the RERTR-program, - characteristics of LEU and HEU, - military HEU enters the civil market, -what is the supply situation for LEU and HEU today? - outlook for safe supplies of LEU and HEU. (author)

  8. A radiological consequence analysis with HEU and LEU fuels

    International Nuclear Information System (INIS)

    Woodruff, W.L.; Warinner, D.K.; Matos, J.E.

    1985-01-01

    A model for estimating the radiological consequences from a hypothetical accident in HEU and LEU fueled research and test reactors is presented. Simple hand calculations based on fission product yield table inventories and nonsite specific dispersion data may be adequate in many cases. However, more detailed inventories and site specific data on meteorological conditions and release rates and heights can result in substantial reductions in the dose estimates. LEU fuel gives essentially the same doses as HEU fuel. The plutonium buildup in the LEU fuel does not significantly increase the radiological consequences. The dose to the thyroid is the limiting dose. (author)

  9. Fuel Management Strategies for a Possible Future LEU Core of a TRIGA Mark II Vienna

    Energy Technology Data Exchange (ETDEWEB)

    Khan, R.; Villa, M.; Steinhauser, G.; Boeck, H. [Vienna University of Technology-Atominstitut (Austria)

    2011-07-01

    The Vienna University of Technology/Atominstitut (VUT/ATI) operates a TRIGA Mark II research reactor. It is operated with a completely mixed core of three different types of fuel. Due to the US fuel return program, the ATI have to return its High Enriched Uranium (HEU) fuel latest by 2019. As an alternate, the Low Enrich Uranium (LEU) fuel is under consideration. The detailed results of the core conversion study are presented at the RRFM 2011 conference. This paper describes the burn up calculations of the new fuel to predict the future burn up behavior and core life time. It also develops an effective and optimized fuel management strategy for a possible future operation of the TRIGA Mark II with a LEU core. This work is performed by the combination of MCNP5 and diffusion based neutronics code TRIGLAV. (author)

  10. [D-Leu-4]-OB3 and MA-[D-Leu-4]-OB3, small molecule synthetic peptide leptin mimetics, improve glycemic control in diet-induced obese (DIO) mice.

    Science.gov (United States)

    Wang, Anke; Anderson, Brian M; Novakovic, Zachary M; Grasso, Patricia

    2018-03-01

    We have previously shown that following oral delivery in dodecyl maltoside (DDM), [D-Leu-4]-OB3 and its myristic acid conjugate, MA-[D-Leu-4]-OB3, improved energy balance and glucose homeostasis in genetically obese/diabetic mouse models. More recently, we have provided immunohistochemical evidence indicating that these synthetic peptide leptin mimetics cross the blood-brain barrier and concentrate in the area of the arcuate nucleus of the hypothalamus in normal C57BL/6J and Swiss Webster mice, in genetically obese ob/ob mice, and in diet-induced obese (DIO) mice. In the present study, we describe the effects of oral delivery of [D-Leu-4]-OB3 and MA-[D-Leu-4]-OB3 on glycemic control in diet-induced (DIO) mice, a non-genetic rodent model of obesity and its associated insulin resistance, which more closely recapitulates common obesity and diabetes in humans. Male C57BL/6J and DIO mice, 17, 20, and 28 weeks of age, were maintained on a low-fat or high-fat diet and given vehicle (DDM) alone or [D-Leu-4]-OB3 or MA-[D-Leu-4]-OB3 in DDM by oral gavage for 12 or 14 days. Body weight gain, food and water intake, fasting blood glucose, oral glucose tolerance, and serum insulin levels were measured. Our data indicate that (1) [D-Leu-4]-OB3 and MA-[D-Leu-4]-OB3 restore glucose tolerance in male DIO mice maintained on a high-fat diet to levels comparable to those of non-obese C57BL/6J wild-type mice of the same age and sex maintained on a low-fat diet; and (2) the influence of [D-Leu-4]-OB3 and MA-[D-Leu-4]-OB3 on glycemic control appears to be independent of their effects on energy balance. These results suggest that [D-Leu-4]-OB3 and/or MA-[D-Leu-4]-OB3 may have application to the management of the majority of cases of common obesity in humans, a state characterized at least in part, by leptin resistance resulting from a defect in leptin transport across the blood-brain barrier. They further suggest that these small molecule synthetic peptide leptin mimetics, through their

  11. Analysis of the Ford Nuclear Reactor LEU core

    Energy Technology Data Exchange (ETDEWEB)

    Rathkopf, J A; Drumm, C R; Martin, W R; Lee, J C [Department of Nuclear Engineering, University of Michigan, Ann Arbor, MI (United States)

    1983-09-01

    This paper has summarized the current status of the effort to analyze the FNR HEU/LEU cores and to compare the calculated results with measurements. In general, calculated predictions of experimental results are quite good, especially for global parameters such as reactivity, as seen in the single HEU/LEU element substitution experiment and the LEU full core critical loading. Shim rod worths are predicted well for two of the rods but too high for a third rod possibly due to inaccurate thermal flux distribution calculation. The calculated thermal flux maps show excellent agreement with experiment throughout the FNR core. In the heavy water tank, however, experimental values for the thermal flux obtained by different methods are inconsistent among themselves as well as with the calculated finding. Work is under.way to use our computational tools to correct the discrepancies between the various measurement techniques and to improve the computational results for flux distribution and the rod worth experiment. Although uncertainties exist in our analysis, as evidenced by the discrepancies mentioned above, we consider our present calculational package to be a useful, reasonably accurate, and efficient system for performing analyses of MTR LEU/HEU core configurations.

  12. Performance of PARR-1 with LEU Fuel

    International Nuclear Information System (INIS)

    Pervez, S.; Latif, M.; Bokhari, I.H.; Bakhtyar, S.

    2005-01-01

    Pakistan Research Reactor (PARR-1) went critical in 1965 with HEU fuel. The reactor core was converted to LEU fuel with power upgradation from 5 MW to 10 MW in 1992. The reactor has been operated with LEU fuel for about 10,000 hours and has produced about 66,000 MWh energy up to now. Average burn up of the irradiated fuel is about 42 %. The fuel performance during the last 12 years has been excellent. Post irradiation visual inspection of the fuel has revealed no abnormality. During operation there have been no signs of releases in the pool water establishing the full integrity of this fuel. The reactor has been mainly utilized for radioisotope production, beam tube experiments including neutron diffraction studies, neutron radiography etc. Studies have been completed to operate the reactor with a mixed core (HEU + LEU) to utilize the less burned HEU fuel elements. A major project of production of fission Moly using PARR-1 is in the final stages. (author)

  13. The LEU target development and conversion program for the MAPLE reactors and new processing facility

    International Nuclear Information System (INIS)

    Malkoske, G.R.

    2002-01-01

    Historically, the production of molybdenum-99 in the NRU research reactors at Chalk River, Canada has been extracted from reactor targets employing highly enriched uranium (HEU). A reliable supply of HEU metal from the United States used in the manufacture of targets for the NRU research reactor has been a key factor to enable MDS Nordion to develop a secure supply of medical isotopes for the international nuclear medicine community. The molybdenum extraction process from HEU targets provides predictable, consistent yields for our high-volume molybdenum production process. Each link of the isotope supply chain, from isotope production to ultimate use by the physician, has been established using this proven and established method of HEU target irradiation and processing to extract molybdenum-99. To ensure a continued reliable and timely supply of medical isotopes, MDS Nordion is completing the construction of two MAPLE reactors and a New Processing Facility. The design of the MAPLE facilities was based on an established process developed by Atomic Energy of Canada Ltd. (AECL) - extraction of isotopes from HEU target material. However, in concert with the global trend to utilize low enriched uranium (LEU) in research reactors, MDS Nordion has launched a three phase LEU Target Development and Conversion Program for the MAPLE facilities. Phase 1, the Initial Feasibility Study, which identified the technical issues to convert the MAPLE reactor targets from HEU to LEU for large scale commercial production was reported on at the RERTR- 2000 conference. The second phase of the LEU Target Development and Conversion Program was developed with extensive consultation and involvement of experts knowledgeable in target development, process system design, enriched uranium conversion chemistry and commercial scale reactor operations and molybdenum production. This paper will provide an overview of the Phase 2 Conversion Development Program, report on progress to date, and further

  14. Making of fission 99Mo from LEU silicide(s): A radiochemists' view

    International Nuclear Information System (INIS)

    Kolar, Z.I.; Wolterbeek, H.Th.

    2005-01-01

    The present-day industrial scale production of 99 Mo is fission based and involves thermal-neutron irradiation in research reactors of highly enriched uranium (HEU, > 20 % 235 U) containing targets, followed by radiochemical processing of the irradiated targets resulting in the final product: a 99 Mo containing chemical compound of molybdenum. In 1978 a program (RERTR) was started to develop a substitute for HEU reactor fuel i.e. a low enriched uranium (LEU, 235 U) one. In the wake of that program studies were undertaken to convert HEU into LEU based 99 Mo production. Both new targets and radiochemical treatments leading to 99 Mo compounds were proposed. One of these targets is based on LEU silicide, U 3 Si 2 . Present paper aims at comparing LEU U 3 Si 2 and LEU U 3 Si with another LEU target i.e. target material and arriving at some preferences pertaining to 99 Mo production. (author)

  15. Preproghrelin Leu72Met polymorphism in obese Korean children.

    Science.gov (United States)

    Jo, Dae-Sun; Kim, Se-Lim; Kim, Sun-Young; Hwang, Pyoung Han; Lee, Kee-Hyoung; Lee, Dae-Yeol

    2005-11-01

    Ghrelin is a novel gut-brain peptide that has somatotropic, orexigenic, and adipogenic effects. We examined the preproghrelin Leu72Met polymorphism in 222 obese Korean children to determine whether it is associated with obesity. The frequencies of the Leu72Met polymorphism were 29.3% in obese, 32.3% in overweight, and 32.5% in lean Korean children. No significant difference was found between Met72 carrier and non-carrier obese children with respect to BMI, total body fat, serum triglycerides, total cholesterol, or LDL-cholesterol levels. Our data suggest that the preproghrelin Leu72Met polymorphism is not associated with obesity in children.

  16. The whole-core LEU fuel demonstration in the ORR

    International Nuclear Information System (INIS)

    Snelgrove, J.L.; Bretscher, M.M.; Cornella, R.J.; Hobbs, R.W.

    1985-01-01

    A whole-core demonstration of LEU fuel in the ORR is expected to begin during November 1985. Fuel elements will contain U 3 Si 2 at 4.8 Mg U/m 3 and shim rod fuel followers will contain U 3 Si 2 at 3.5 Mg U/m 3 . Fuel fabrication is underway at B and W, CERCA, and NUKEM, with shipments scheduled to commence in October. The primary objectives of the demonstration are to provide data for validation of LEU and mixed-core fuel cycle calculations and to provide a large-scale demonstration of the acceptable performance of production-line U 3 Si 2 fuel elements. It is planned to approach the full LEU core through a series of mixed cores. Measurements to be made include flux distribution, reactivity swing, control rod worth, cycle length, fuel discharge burn-up, gamma heating rate, β eff /l, and isothermal temperature coefficient. Measurements will also be made on fresh LEU and fresh HEU critical configurations. Preliminary safety approval has been received and the final safety assessment is being reviewed. Key issues being addressed in the safety assessment are fuel performance, radiological consequences, margin to burnout and transient behavior. The LEU core is comparable in all safety aspects to the HEU core and the transition core is only marginally worse owing to higher power seeking factors. (author)

  17. Preliminary LEU fuel cycle analyses for the Belgian BR2 reactor

    International Nuclear Information System (INIS)

    Deen, J.R.; Snelgrove, J.L.

    1986-01-01

    Fuel cycle calculations have been performed with reference HEU fuel and LEU fuel using Cd wires or boron as burnable absorbers. The 235 U content in the LEU element has increased 20% to 480g compared to the reference HEU element. The number of fuel plates has remained unchanged while the fuel meat thickness has increased to 0.76 mm from 0.51 mm. The LEU meat density is 5.1 Mg U/m 3 . The reference fuel cycle was a 31 element core operating at 56 MW with a 19.8 day cycle length and eight fresh elements loaded per cycle. Comparable fuel cycle characteristics can be achieved using the proposed LEU fuel element with either Cd wires or boron burnable absorbers. The neutron flux for E/sub n/ > 1 eV changes very little (<5%) in LEU relative to HEU cores. Thermal flux reductions are 5 to 10% in non-fueled positions, and 20 to 30% in fuel elements

  18. Operating experience, measurements, and analysis of the LEU whole core demonstration at the FNR

    International Nuclear Information System (INIS)

    Weha, D.K.; Drumm, C.R.; King, J.S.; Martin, W.R.; Lee, J.C.

    1984-01-01

    The 2-MW Ford Nuclear Reactor at the University of Michigan is serving as the demonstration reactor for the MTR-type low enrichment (LEU) fuel for the Reduced Enrichment for Research and Test Reactor program. Operational experience gained through six months of LEU core operation and seven months of mixed HEU-LEU core operation is presented. Subcadmium flux measurements performed with rhodium self-powered neutron detectors and iron wire activations are compared with calculations. Measured reactivity parameters are compared for HEU and LEU cores. Finally, the benchmark calculations for several HEU, LEU, and mixed HEU-LEU FNR cores and the International Atomic Energy Agency (IAEA) benchmark problem are presented. (author)

  19. The manufacture of LEU fuel elements at Dounreay

    Energy Technology Data Exchange (ETDEWEB)

    Gibson, J.

    1997-08-01

    Two LEU test elements are being manufactured at Dounreay for test irradiation in the HFR at Petten, The Netherlands. This paper describes the installation of equipment and the development of the fabrication and inspection techniques necessary for the manufacture of LEU fuel plates. The author`s experience in overcoming the technical problems of stray fuel particles, dog-boning, uranium homogeneity and the measurement of uranium distribution is also described.

  20. Total synthesis of fully tritiated Leu-enkephalin by enzymatic coupling

    Energy Technology Data Exchange (ETDEWEB)

    Hellio, F.; Lecocq, G.; Morgat, J.L.; Gueguen, P. (CEA Centre d' Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France). Service de Biochimie)

    1990-09-01

    This paper describes the total enzymatic synthesis of Leu-enkephalin (Tyr-Gly-Gly-Phe-Leu) in which all residues were labelled with tritium. Carboxypeptidase Y from Saccharomyces cerevisiae was the coupling enzyme. ({sup 3}H)-Tyr-NH{sub 2}, ({sup 3}H)-Gly-Oet, ({sup 3}H)-Phe-NH{sub 2} and ({sup 3}H)-Leu-NH{sub 2} were prepared with specific radioactivities ranging between 20 and 60 Ci/mmol (740 to 2220 GBq/mmol). Using a microscale procedure, we obtained a fully tritiated hormone having a specific radioactivity equal to 139 Ci/mmol (5143 GBq/mmol), in agreement with the summation of the specific radioactivities of constituting residue. The radioactive hormone had antigenic properties identical to those of native Leu-enkephalin. It also bound to rat brain opiate receptors like the parental hormone. (author).

  1. Preproghrelin Leu72Met polymorphism in patients with type 2 diabetes mellitus.

    Science.gov (United States)

    Ukkola, O; Kesäniemi, Y A

    2003-10-01

    The association between the Leu72Met polymorphism of the preproghrelin gene and diabetic complications was examined in patients with type 2 diabetes mellitus. A total of 258 patients with type 2 diabetes mellitus and 522 control subjects were screened. Genotypes were determined by polymerase chain reaction technique. The diagnosis of coronary heart disease was based on clinical and ECG criteria. Laboratory analyses were carried out in the hospital laboratory. No differences in the genotype distributions and allele frequencies of the preproghrelin Leu72Met polymorphism were found between type 2 diabetes mellitus patients and controls. The polymorphism was not associated with macro- or micro-angiopathy or hypertension. However, Leu72Met polymorphism was associated with serum creatinine (P = 0.006) and lipoprotein(a) [Lp(a)] levels (P = 0.006) with Leu72Leu subjects showing the highest values. This association was observed only amongst diabetic group. The Leu72Met polymorphism of the preproghrelin gene was not related to cardiovascular disease in type 2 diabetes mellitus patients. Leu72Met polymorphism was, however, associated with serum creatinine and Lp(a) levels in diabetic patients. The mechanism might be associated with a possible change in ghrelin product and its somatotropic effect.

  2. Pressure effect on the conformational equilibrium of [Leu]{sup 5}-enkephalin in water

    Energy Technology Data Exchange (ETDEWEB)

    Shimizu, A [Department of Environmental Engineering for Symbiosis, Soka University, 1-326 Tangi-cho, Hachioji, Tokyo, 192-8577 (Japan); Takekiyo, T; Yoshimura, Y [Department of Applied Chemistry, National Defence Academy, 1-10-20 Hashirimizu, Yokosuka, Kanagawa, 239-8686 (Japan); Kato, M; Taniguchi, Y, E-mail: shimizu@soka.ac.j, E-mail: take214@nda.ac.j [Department of Applied Chemistry, Ritsumeikan University, 1-1-1, Nojihigashi, Kusatsu, Shiga, 525-8577 (Japan)

    2010-03-01

    The conformational stability of [Leu]{sup 5}-enkephalin,Tyr-Gly-Gly-Phe-Leu, in water have been investigated under high pressure by FTIR spectroscopy. Three peaks at 1638, 1650, and 1680 cm{sup -1} were determined by second derivative FTIR spectra in the amide I' region of [Leu]{sup 5}-enkephalin. The peaks at 1637 and 1680 cm{sup -1} are assigned to the {beta}-strand and turn structures, respectively. These peaks mean that [Leu]{sup 5}-enkephalin takes a {beta}-hairpin-like structure in water. Moreover, the absorbance at 1638 cm{sup -1} increases with increasing pressure, and this change shows a sigmoidal curve. Thus, we concluded that [Leu]{sup 5}-enkephalin has the {beta}-hairpin-like and disordered structures in water. From the FTIR profile at high pressures, the {beta}-hairpin-like structure of [Leu]{sup 5}-enkephalin is stabilized by a high pressures. Our result shows that the folded structures such as {alpha}-helix and {beta}-hairpin structures of short peptide such as [Leu]{sup 5}-enkephalin are stabilized at high pressures.

  3. The Environment Shapes the Inner Vestibule of LeuT

    DEFF Research Database (Denmark)

    Sohail, Azmat; Jayaraman, Kumaresan; Venkatesan, Santhoshkannan

    2016-01-01

    Human neurotransmitter transporters are found in the nervous system terminating synaptic signals by rapid removal of neurotransmitter molecules from the synaptic cleft. The homologous transporter LeuT, found in Aquifex aeolicus, was crystallized in different conformations. Here, we investigated t...... showed TM1A movements, consistent with the simulations, confirming a substantially different inward-open conformation in lipid bilayer from that inferred from the crystal structure....... the inward-open state of LeuT. We compared LeuT in membranes and micelles using molecular dynamics simulations and lanthanide-based resonance energy transfer (LRET). Simulations of micelle-solubilized LeuT revealed a stable and widely open inward-facing conformation. However, this conformation was unstable...... in a membrane environment. The helix dipole and the charged amino acid of the first transmembrane helix (TM1A) partitioned out of the hydrophobic membrane core. Free energy calculations showed that movement of TM1A by 0.30 nm was driven by a free energy difference of ~15 kJ/mol. Distance measurements by LRET...

  4. Neutronic study on conversion of SAFARI-1 to LEU silicide fuel

    International Nuclear Information System (INIS)

    Ball, G.; Pond, R.; Hanan, N.; Matos, J.

    1995-01-01

    This paper marks the initial study into the technical and economic feasibility of converting the SAFARI-1 reactor in South Africa to LEU silicide fuel. Several MTR assembly geometries and LEU uranium densities have been studied and compared with MEU and HEU fuels. Two factors of primary importance for conversion of SAFARI-1 to LEU fuel are the economy of the fuel cycle and the performance of the incore and excore irradiation positions

  5. Heat-transfer analysis of the existing HEU and proposed LEU cores of Pakistan research reactor

    International Nuclear Information System (INIS)

    Khan, L.A.; Nabbi, R.

    1987-02-01

    In connection with conversion of Pakistan Research Reactor (PARR) from the use of Highly Enriched Uranium (HEU) fuel to the use of Low Enriched Uranium (LEU) fuel, steady-state thermal hydraulic analysis of both existing HEU and proposed LEU cores has been carried out. Keeping in mind the possibility of power upgrading, the performance of proposed LEU core, under 10 MW operating conditions, has also been evaluated. Computer code HEATHYD has been used for this purpose. In order to verify the reliability of the code, IAEA benchmark 2 MW reactor was analyzed. The cooling parameters evaluated include: coolant velocity, critical velocity, pressure drop, temperature distribution in the core, heat fluxes at onset of nucleate boiling, flow instability and burnout and corresponding safety margins. From the results of the study it can be concluded that the conversion of the core to LEU fuel will result in higher safety margins, as compared to existing HEU core, mainly because the increased number of fuel plates in the proposed design will reduce the average heat flux significantly. Anyhow upgrading of the reactor power to 10 MW will need the flow rate to be adjusted between 850 to 900 m 3 /hr, to achieve reasonable safety margins, at least, comparable with the existing HEU core. (orig.)

  6. A conversion development program to LEU targets for medical isotope production in the MAPLE Facilities

    International Nuclear Information System (INIS)

    Malkoske, G.R.

    2000-01-01

    Historically, the production of molybdenum-99 in the NRU research reactors at Chalk River, Canada has been extracted from reactor targets employing highly enriched uranium (HEU). The molybdenum extraction process from the HEU targets provided predictable, consistent yields for our high-volume molybdenum production process. A reliable supply of HEU for the NRU research reactor targets has enabled MDS Nordion to develop a secure chain of medical isotope supply for the international nuclear medicine community. Each link of the isotope supply chain, from isotope production to patient application, has been established on a proven method of HEU target irradiation and processing. To ensure a continued reliable and timely supply of medical isotopes, the design of the MAPLE facilities was based on our established process - extraction of isotopes from HEU target material. However, in concert with the global trend to utilize low enriched uranium (LEU) in research reactors, MDS Nordion has launched a program to convert the MAPLE facilities to LEU targets. An initial feasibility study was initiated to identify the technical issues to convert the MAPLE targets from HEU to LEU. This paper will present the results of the feasibility study. It will also describe future challenges and opportunities in converting the MAPLE facilities to LEU targets for large scale, commercial medical isotope production. (author)

  7. Progress in chemical processing of LEU targets for 99Mo production - 1997

    International Nuclear Information System (INIS)

    Vandegrift, G.F.; Conner, C.; Sedlet, J.; Wygmans, D.G.; Wu, D.; Iskander, F.; Landsberger, S.

    1997-01-01

    Presented here are recent experimental results of our continuing development activities associated with converting current processes for producing fission-product 99 Mo from targets using high-enriched uranium (HEU) to low-enriched uranium (LEU). Studies were focused in four areas: (1) measuring the chemical behavior of iodine, rhodium, and silver in the LEU-modified Cintichem process, (2) performing experiments and calculations to assess the suitability of zinc fission barriers for LEU metal foil targets, (3) developing an actinide separations method for measuring alpha contamination of the purified 99 Mo product, and (4) developing a cooperation with Sandia National Laboratories and Los Alamos National Laboratory that will lead to approval by the U.S. Federal Drug Administration for production of 99 Mo from LEU targets. Experimental results continue to show the technical feasibility of converting current HEU processes to LEU. (author)

  8. An investigative approach to explore optimum assembly process design for annular targets carrying LEU foil

    Science.gov (United States)

    Hoyer, Annemarie

    Technetium-99m is the most widely used nuclear isotope in the medical field, with nearly 80 to 85% of all diagnostic imaging procedures. The daughter isotope of molybdenum-99 is currently produced using weapons-grade uranium. A suggested design for aluminum targets carrying low-enriched uranium (LEU) foil is presented for the fulfillment of eliminating highly enriched uranium (HEU) for medical isotope production. The assembly process that this research focuses on is the conventional draw-plug process which is currently used and lastly the sealing process. The research is unique in that it is a systematic approach to explore the optimal target assembly process to produce those targets with the required quality and integrity. Conducting 9 parametric experiments, aluminum tubes with a nickel foil fission-barrier and a surrogate stainless steel foil are assembled, welded and then examined to find defects, to determine residual stresses, and to find the best cost-effective target dimensions. The experimental design consists of 9 assembly combinations that were found through orthogonal arrays in order to explore the significance of each factor. Using probabilistic modeling, the parametric study is investigated using the Taguchi method of robust analysis. Depending on the situation, optimal conditions may be a nominal, a minimized or occasionally a maximized condition. The results will provide the best target design and will give optimal quality with little or no assembly defects.

  9. Continuing investigations for technology assessment of 99Mo production from LEU [low enriched Uranium] targets

    International Nuclear Information System (INIS)

    Vandergrift, G.F.; Kwok, J.D.; Marshall, S.L.; Vissers, D.R.; Matos, J.E.

    1987-01-01

    Currently much of the world's supply of /sup 99m/Tc for medical purposes is produced from 99 Mo derived from the fissioning of high enriched uranium (HEU). The need for /sup 99m/Tc is continuing to grow, especially in developing countries, where needs and national priorities call for internal production of 99 Mo. This paper presents the results of our continuing studies on the effects of substituting low enriched Uranium (LEU) for HEU in targets for the production of fission product 99 Mo. Improvements in the electrodeposition of thin films of uranium metal are reported. These improvements continue to increase the appeal for the substitution of LEU metal for HEU oxide films in cylindrical targets. The process is effective for targets fabricated from stainless steel or hastaloy. A cost estimate for setting up the necessary equipment to electrodeposit uranium metal on cylindrical targets is reported. Further investigations on the effect of LEU substitution on processing of these targets are also reported. Substitution of uranium silicides for the uranium-aluminum alloy or uranium aluminide dispersed fuel used in other current target designs will allow the substitution of LEU for HEU in these targets with equivalent 99 Mo-yield per target and no change in target geometries. However, this substitution will require modifications in current processing steps due to (1) the insolubility of uranium silicides in alkaline solutions and (2) the presence of significant quantities of silicate in solution. Results to date suggest that both concerns can be handled and that substitution of LEU for HEU can be achieved

  10. Preproghrelin Leu72Met polymorphism in Chinese subjects with coronary artery disease and controls.

    Science.gov (United States)

    Tang, Na-Ping; Wang, Lian-Sheng; Yang, Li; Gu, Hai-Juan; Zhu, Huai-Jun; Zhou, Bo; Sun, Qing-Min; Cong, Ri-Hong; Wang, Bin

    2008-01-01

    Ghrelin, a novel endogenous ligand for the growth hormone secretagogue receptor, is considered to exert a protective effect against atherosclerosis. The Leu72Met (+408C>A) polymorphic variant of the preproghrelin, the gene for the ghrelin precursor, has been linked to obesity, diabetes and metabolic syndrome. However, it is unclear whether this polymorphism is associated with coronary artery disease (CAD). We conducted a case-control study with 317 CAD patients and 323 controls to investigate the potential association of the Leu72Met polymorphism with the occurrence of CAD and CAD-related phenotypes in Chinese population. No significant difference in the Leu72Met genotype frequency was observed between CAD patients and controls (P=NS). The Leu72Met polymorphism was not associated with hypertension, diabetes, dyslipidemia, the number of diseased vessels, plasma total cholesterol, triglyceride, high density lipoprotein cholesterol, low density lipoprotein cholesterol or fasting glucose levels in CAD patients. However, among CAD patients, those with variant genotypes (Leu72Met and Met72Met) had lower BMI (24.4+/-0.3 kg/m(2)) than Leu72Leu carriers (25.4+/-0.2 kg/m(2), adjusted P=0.033). Our data indicate that the preproghrelin Leu72Met polymorphism is not associated with CAD in Chinese population. However, the Leu72Met variant is associated with BMI among CAD patients.

  11. A comparison of the radiological consequences of a HEU and LEU fueled research reactor

    International Nuclear Information System (INIS)

    Kollas, J.G.

    1985-01-01

    An analysis of the design basis accident radiological consequences of the HEU and LEU fueled Greek Research Reactor is presented. Doses and individual cancer risk from exposure to the passing radioactive cloud are estimated up to a distance of 20 km from the reactor site. Collective exposure and latent health effects are estimated for the total Athens area of 3081000 inhabitants. The results indicate that the plutonium isotopes buildup in the LEU fuel does not increase appreciably the consequences in respect to the HEU fueled reactor. The plutonium impact concerns mainly bone effects and secondly lung and whole body effects. The contribution to the limiting thyroid dose and the corresponding thyroid effects is insignificant. (author)

  12. Genetic interaction between the ero1-1 and leu2 mutations in Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    López-Mirabal, H Reynaldo; Winther, Jakob R; Kielland-Brandt, Morten C

    2007-01-01

    of the ero1-1 mutation were carried out in a leu2 mutant. The ero1-1 leu2 strain does not grow in standard synthetic complete medium at 30 degrees C, a defect that can be remedied by increasing the L-leucine concentration in the medium or by transforming the ero1-1 leu2 strain with the LEU2 wild-type allele...

  13. Fuel cycle cost study with HEU and LEU fuels

    International Nuclear Information System (INIS)

    Matos, J.E.; Freese, K.E.

    1984-01-01

    Fuel cycle costs are compared for a range of 235 U loadings with HEU and LEU fuels using the IAEA generic 10 MW reactor as an example. If LEU silicide fuels are successfully demonstrated and licensed, the results indicate that total fuel cycle costs can be about the same or lower than those with the HEU fuels that are currently used in most research reactors

  14. Substrate-modulated unwinding of transmembrane helices in the NSS transporter LeuT.

    Science.gov (United States)

    Merkle, Patrick S; Gotfryd, Kamil; Cuendet, Michel A; Leth-Espensen, Katrine Z; Gether, Ulrik; Loland, Claus J; Rand, Kasper D

    2018-05-01

    LeuT, a prokaryotic member of the neurotransmitter:sodium symporter (NSS) family, is an established structural model for mammalian NSS counterparts. We investigate the substrate translocation mechanism of LeuT by measuring the solution-phase structural dynamics of the transporter in distinct functional states by hydrogen/deuterium exchange mass spectrometry (HDX-MS). Our HDX-MS data pinpoint LeuT segments involved in substrate transport and reveal for the first time a comprehensive and detailed view of the dynamics associated with transition of the transporter between outward- and inward-facing configurations in a Na + - and K + -dependent manner. The results suggest that partial unwinding of transmembrane helices 1/5/6/7 drives LeuT from a substrate-bound, outward-facing occluded conformation toward an inward-facing open state. These hitherto unknown, large-scale conformational changes in functionally important transmembrane segments, observed for LeuT in detergent-solubilized form and when embedded in a native-like phospholipid bilayer, could be of physiological relevance for the translocation process.

  15. Progress on LEU very high density fuel and target development in Argentina

    International Nuclear Information System (INIS)

    Balart, S.; Cabot, P.; Calzetta, O.; Duran, A.; Garces, J.; Hermida, J.D.; Manzini, A.; Pasqualini, E.; Taboada, H.

    2006-01-01

    Since last RRFM meeting, CNEA has continued on new LEU fuel and target development activities. Main goals are the plan to convert our RA-6 reactor from HEU to a new LEU core, to get a comprehensive understanding of U-Mo/Al compounds phase formation in dispersed and monolithic fuels, to develop possible solutions to VHD dispersed and monolithic fuels technical problems, to optimize techniques to recover U from silicide scrap samples as cold test for radiowaste separation for final conditioning of silicide spent fuels. and to improve the diffusion of LEU target and radiochemical technology for radioisotope production. Future plans include: - Completion of the RA-6 reactor conversion to LEU; - Improvement on fuel development and production facilities to implement new technologies, including NDT techniques to assess bonding quality; - Irradiation of miniplates and full scale fuel assembly at RA-3 and plans to perform irradiation on higher power and temperature regime reactors; - Optimization of LEU target and radiochemical techniques for radioisotope production. (author)

  16. LEU-HTR critical experiment program for the PROTEUS facility in Switzerland

    International Nuclear Information System (INIS)

    Brogli, R.; Bucher, K.H.; Chawla, R.; Foskolos, K.; Luchsinger, H.; Mathews, D.; Sarlos, G.; Seiler, R.

    1990-01-01

    New critical experiments in the framework of an IAEA Coordinated Research Program on 'Validation of Safety Related Reactor Physics Calculations for Low Enriched HTRs' are planned at the PSI PROTEUS facility. The experiments are designed to supplement the experimental data base and reduce the design and licensing uncertainties for small- and medium-sized helium-cooled reactors using low-enriched uranium (LEU) and graphite high temperature fuel. The main objectives of the new experiments are to provide first-of-a-kind high quality experimental data on: 1) The criticality of simple, easy to interpret, single core region LEU HTR systems for several moderator-to-fuel ratios and several lattice geometries; 2) the changes in reactivity, neutron balance components and control rod effectiveness caused by water ingress into this type of reactor, and 3) the effects of the boron and/or hafnium absorbers that are used to modify the reactivity and the power distributions in typical HTR systems. Work on the design and licensing of the modified PROTEUS critical facility is now in progress with the HTR experiments scheduled to begin early in 1991. Several international partners will be involved in the planning, execution and analysis of these experiments in order to insure that they are relevant and cost effective with respect to the various gas cooled reactor national programs. (author)

  17. LEU-HTR critical experiment program for the PROTEUS facility in Switzerland

    Energy Technology Data Exchange (ETDEWEB)

    Brogli, R; Bucher, K H; Chawla, R; Foskolos, K; Luchsinger, H; Mathews, D; Sarlos, G; Seiler, R [Paul Scherrer Institute, Laboratory for Reactor Physics and System Technology Wuerenlingen and Villigen, Villigen PSI (Switzerland)

    1990-07-01

    New critical experiments in the framework of an IAEA Coordinated Research Program on 'Validation of Safety Related Reactor Physics Calculations for Low Enriched HTRs' are planned at the PSI PROTEUS facility. The experiments are designed to supplement the experimental data base and reduce the design and licensing uncertainties for small- and medium-sized helium-cooled reactors using low-enriched uranium (LEU) and graphite high temperature fuel. The main objectives of the new experiments are to provide first-of-a-kind high quality experimental data on: 1) The criticality of simple, easy to interpret, single core region LEU HTR systems for several moderator-to-fuel ratios and several lattice geometries; 2) the changes in reactivity, neutron balance components and control rod effectiveness caused by water ingress into this type of reactor, and 3) the effects of the boron and/or hafnium absorbers that are used to modify the reactivity and the power distributions in typical HTR systems. Work on the design and licensing of the modified PROTEUS critical facility is now in progress with the HTR experiments scheduled to begin early in 1991. Several international partners will be involved in the planning, execution and analysis of these experiments in order to insure that they are relevant and cost effective with respect to the various gas cooled reactor national programs. (author)

  18. TRIGA high wt -% LEU fuel development program. Final report

    International Nuclear Information System (INIS)

    West, G.B.

    1980-07-01

    The principal purpose of this work was to investigate the characteristics of TRIGA fuel where the contained U-235 was in a relatively high weight percent (wt %) of LEU (low enriched uranium - enrichment of less than 20%) rather than a relatively low weight percent of HEU (high enriched uranium). Fuel with up to 45 wt % U was fabricated and found to be acceptable after metallurgical examinations, fission product retention tests and physical property examinations. Design and safety analysis studies also indicated acceptable prompt negative temperature coefficient and core lifetime characteristics for these fuels

  19. The Pai-associated leuX specific tRNA5(Leu) affects type 1fimbriation in pathogenic Escherichia coli by control of FimB recombinase expression

    DEFF Research Database (Denmark)

    Ritter, A.; Gally, D.; Olsen, Peter Bjarke

    1997-01-01

    The uropathogenic Escherichia coli strain 536 (06:K15:H31) carries two large chromosomalpathogenicity islands (Pais). Both Pais are flanked by tRNA genes. Spontaneous deletion of Pai IIresults in truncation of the leuX tRNA5Leu gene. This tRNA is required for the expression of type 1fimbriae (Fim...

  20. Progress in chemical treatment of LEU targets by the modified Cintichem process

    International Nuclear Information System (INIS)

    Wu, D.; Landsberger, S.; Vandegrift, G.F.

    1996-01-01

    Presented here are recent experimental results on tests of a modified Cintichem process for producing 99 Mo from low enriched uranium (LEU). Studies were focused in three areas: (1) testing the effects on 99 Mo recovery and purity of dissolving LEU foil in nitric acid alone, rather than in the sulfuric/nitric acid mixture currently used, (2) measuring decontamination factors for radionuclide impurities in each purification step, and (3) testing the effects on processing of adding barrier materials to the LEU metal-foil target. The experimental results show that switching from dissolving the target in the sulfuric/nitric mixture to using nitric acid alone should cause no significant difference in 99 Mo product yield or purity. Further, the results show that overall decontamination factors for gamma emitters in the LEU-target processing are high enough to meet the purity requirements for the 99 Mo product. The results also show that the selected barrier materials, Cu, Fe, and Ni, do not interfere with 99 Mo recovery and can be removed during chemical processing of the LEU target

  1. Analyses for inserting fresh LEU fuel assemblies instead of fresh HEU fuel assemblies in the Dalat Nuclear Research Reactor in Vietnam

    International Nuclear Information System (INIS)

    Hanan, N. A.; Deen, J.R.; Matos, J.E.

    2005-01-01

    Analyses were performed by the RERTR Program to replace 36 burned HEU (36%) fuel assemblies in the Dalat Nuclear Research Reactor in Vietnam with either 36 fresh fuel assemblies currently on-hand at the reactor or with LEU fuel assemblies to be procured. The study concludes that the current HEU (36%) WWR-M2 fuel assemblies can be replaced with LEU WWR-M2 fuel assemblies that are fully-qualified and have been commercially available since 2001 from the Novosibirsk Chemical Concentrates Plant in Russia. The current reactor configuration using re-shuffled HEU fuel began in June 2004 and is expected to allow normal operation until around August 2006. If 36 HEU assemblies each with 40.2 g 235 U are inserted without fuel shuffling over the next five operating cycles, the core could operate for an additional 10 years until June 2016. Alternatively, inserting 36 LEU fuel assemblies each containing 49.7 g 235 U without fuel shuffling over five operating cycles would allow normal operation for about 14 years from August 2006 until October 2020. The main reason for the longer service life of the LEU fuel is that its 235 U content is higher than the 235 U content needed simply to match the service life of the HEU fuel. Fast neutron fluxes in the experiment regions would be very nearly the same in both the HEU and LEU cores. Thermal neutron fluxes in the experiment regions would be lower by 1-5%, depending on the experiment type and location. (author)

  2. Neutronic calculations in core conversion of the IAN-R1 research reactor from MTR HEU to TRIGA LEU fuel

    International Nuclear Information System (INIS)

    Sarta Fuentes, Jose A.; Castiblanco, L.A.

    2003-01-01

    With cooperation of the International Atomic Energy Agency (IAEA), neutronic calculations were carried out for conversion of the Ian-R1 Reactor from MTR-HEU fuel to TRIGA-LEU fuel. In order to establish a staff for neutronic calculation at the Instituto de Cancan's Nucleares y Energia s Alternatives (INEA) a program was established. This program included training, acquisition of hardware, software and calculation for the core with MTR-HEU fuel , enriched nominally to 93% and calculation for several arrangements with the TRIGA-LEU fuel, enriched to 19.7%. The results were verified and compared with several groups of calculation at the Instituto Nacional de Investigaciones Nucleares (ININ) in Mexico, and General Atomics (GA) in United States. As a result of this program, several technical reports have been wrote. (author)

  3. Status of LEU conversion program at CRNL

    International Nuclear Information System (INIS)

    Kennedy, I.C.

    1991-01-01

    After briefly reviewing the salient features of the NRU Reactor at Chalk River Nuclear Laboratories (CRNL), the progress of our LEU fuel development and testing program is described. The results (to date) of full-size prototype fuel-rod irradiations are reviewed, and the status of the new fuel-fabrication facility on the site is updated. Although development work is proceeding on U 3 Si 2 dispersions, all indications so far are that CRNL's U 3 Si fuel is fully acceptable for reactor operation. Fuel rods from the new fabrication shop will be installed in NRU in 1990, and the complete core conversion of NRU to LEU driver fuel is expected by 1991. (orig.)

  4. Progress in safety evaluation for the JMTR core conversion to LEU fuel

    International Nuclear Information System (INIS)

    Sakurai, F.; Komori, Y.; Saito, J.; Komukai, B.; Ando, H.; Nakata, H.; Sakakura, A.; Niiho, S.; Saito, M.; Futamura, Y.

    1991-01-01

    The JMTR (50 MWt) has been in steady operation with MEU fuel since July 1986. The effort is still continued to convert the core from MEU to LEU fuel. The LEU silicide fuel element at 4.8 gU/cm 3 with Cd wires as burnable absorbers has been selected in order to achieve upgraded fuel cycle performance of extended cycle length and reduced control rod movement operation. The neutronic calculation methods (diffusion theory model) developed for the LEU core with Cd wires was benchmarked with a detailed Monte Carlo model and verified experimentally using the critical facility, JMTRC. Hydraulic tests of the LEU silicide fuel element with Cd wires were completed with satisfactory results, and measurements of release/born (R/B) ratios of FPs of silicide fuel at high temperature are in progress. (orig.)

  5. Selection of LEU/Th reference fuel for the HTGR-SC/C lead plant

    International Nuclear Information System (INIS)

    Turner, R.F.; Neylan, A.J.; Baxter, A.M.; McEachern, D.W.; Stansfield, O.M.

    1983-05-01

    This paper describes the reference fuel materials for the high-temperature gas-cooled reactor (HTGR) plant for steam cycle/cogeneration (SC/C). A development and testing program carried out in 1978 through 1982 led to the selection of coated fuel particles of uranium-oxycarbide (UCO) for fissile materials and thorium oxide (ThO 2 ) for fertiel materials. Low-enriched uranium (LEU) is the enrichment basis for the HTGR-SC/C application. While UC 2 and UO 2 would also meet the essential criteria for fissile fuel, the UCO, alternative was selected on the basis of improved performance, economics, and process conditions

  6. Measurements of the HEU and LEU in-core spectra at the Ford Nuclear Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Wehe, D K [Oak Ridge National Laboratory, Oak Ridge, TN (United States); King, J S; Lee, J C; Martin, W R [Department of Nuclear Engineering, University of Michigan, Ann Arbor, MI (United States)

    1985-07-01

    The Ford Nuclear Reactor (FNR) at the University of Michigan has been serving as the test site for a low-enriched uranium (LEU) fuel whole-core demonstration. As part of the experimental program, the differential neutron spectrum has been measured in a high-enriched uranium (HEU) core and an LEU core. The HEU and LEU spectra were determined by unfolding the measured activities of foils that were irradiated in the reactor. When the HEU and LEU spectra are compared from meV to 10 MeV, significant differences between the two spectra are apparent below 10 eV. These are probably caused by the additional {sup 238}U resonance absorption in the LEU fuel. No measurable difference occurs in the shape of the spectra above MeV. (author)

  7. Mo-99 production on a LEU solution reactor

    International Nuclear Information System (INIS)

    Brown, R.W.; Thome, L.A.; Khvostionov, V.Y.

    2005-01-01

    A pilot homogenous reactor utilizing LEU has been developed by the Kurchatov Institute in Moscow along with their commercial partner TCI Medical. This solution reactor operates at levels up to 50 kilowatts and has successfully produced high quality Mo-99 and Sr-89. Radiochemical extraction of medical radionuclides from the reactor solution is performed by passing the solution across a series of inorganic sorbents. This reactor has commercial potential for medical radionuclide production using LEU UO 2 SO 4 fuel. Additional development work is needed to optimize multiple 50 kilowatt cores while at the same time, optimizing production efficiency and capital expenditure. (author)

  8. A fuel cycle cost study with HEU and LEU fuels

    International Nuclear Information System (INIS)

    Matos, J.E.; Freese, K.E.

    1985-01-01

    Fuel cycle costs are compared for a range of 235 U loadings with HEU and LEU fuels using the IAEA generic 10 MW reactor as an example. If LEU silicide fuels are successfully demonstrated and licensed, the results indicate that total fuel cycle costs can be about the same or lower than those with the HEU fuels that are currently used in most research reactors. (author)

  9. A fuel cycle cost study with HEU and LEU fuels

    Energy Technology Data Exchange (ETDEWEB)

    Matos, J E; Freese, K E [Argonne National Laboratory, Argonne, IL (United States)

    1985-07-01

    Fuel cycle costs are compared for a range of {sup 235}U loadings with HEU and LEU fuels using the IAEA generic 10 MW reactor as an example. If LEU silicide fuels are successfully demonstrated and licensed, the results indicate that total fuel cycle costs can be about the same or lower than those with the HEU fuels that are currently used in most research reactors. (author)

  10. Status of LEU fuel development and conversion of NRU

    International Nuclear Information System (INIS)

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

    1989-11-01

    The status of the low-enrichment uranium (LEU) fuel development and NRU conversion program at Chalk River Nuclear Laboratories is reviewed. Construction of a new fuel fabrication facility is essentially completed and installation of LEW fuel manufacturing equipment has begun. The irradiation of 31 prototype Al-61 wt% U 3 Si dispersion fuel rods, approximately one third of a full NRU core, is continuing without incident. Recent post-irradiation examination of spent fuel rods revealed that the prototype LEU fuel achieved the design burnup (80 at%) in excellent condition, confirming that the Al-U 3 Si 2 dispersion fuel to complement out Al-U 3 Si capability. Three full-size NRU rods containing Al-U 3 Si 2 dispersion fuel have been fabricated for a qualification irradiation in NRU. Post-irradiation examinations of mini-elements containing Al-U 3 Si 2 fuel revealed that the U 3 Si 2 behaved similarly to U 3 Si 2 fuel revealed that the U 3 Si 2 particles and the aluminum matrix, and fission gas bubbles up to 10 μm in diameter, could be seen in the particles after 60 at% and 80 at% burnup. The mini-elements contained a variety of silicide particle sizes; however, no significant swelling dependence on particle size distribution was observed

  11. Preproghrelin Leu72Met polymorphism is not associated with type 2 diabetes mellitus.

    Science.gov (United States)

    Kim, Sun-Young; Jo, Dae-Sun; Hwang, Pyoung Han; Park, Ji Hyun; Park, Sung Kwang; Yi, Ho Keun; Lee, Dae-Yeol

    2006-03-01

    Ghrelin is a novel gut-brain peptide, which exerts somatotropic, orexigenic, and adipogenic effects. Genetic variants of ghrelin have been associated with both obesity and insulin metabolism. In this study, we determined a role of preproghrelin Leu72Met polymorphism on type 2 diabetes mellitus and its relationship to variables studied. Genotypes were assessed by polymerase chain reaction. Frequencies of the Leu72Met polymorphism were found to be 35.4% in the type 2 diabetic patients and 32.5% in the normal controls. The Leu72Met polymorphism was not associated with hypertension, macroangiopathy, retinopathy, serum cholesterol, triglyceride, blood urea nitrogen, HbA(1c), lipoprotein (a), fasting insulin, or 24-hour urinary protein levels in the type 2 diabetic group. However, the Leu72Met polymorphism was clearly associated with serum creatinine levels in the diabetic group, as the Met72 carriers exhibited lower serum creatinine levels than the Met72 noncarriers. Our data indicate that the preproghrelin Leu72Met polymorphism is not associated with type 2 diabetes mellitus. However, the Leu72Met polymorphism is associated with serum creatinine levels. These data suggest that Met72 carrier status may be a predictable marker for diabetic nephropathy or renal impairment in type 2 diabetes mellitus.

  12. Reclamation and reuse of LEU silicide fuel from manufacturing scrap

    International Nuclear Information System (INIS)

    Gale, G.R.; Pace, B.W.; Evans, R.S.

    2004-01-01

    In order to provide an understanding of the organization which is the sole supplier of United States plate type research and test reactor fuel and LEU core conversions, a brief description of the structure and history is presented. Babcock and Wilcox (B and W) is a part of McDermott International, Inc. which is a large diversified corporation employing over 20,000 people primarily in engineering and construction for the off-shore oil and power generation industries throughout the world. B and W provides many energy related products requiring precision machining and high quality systems. This is accomplished by using state-of-the-art equipment, technology and highly skilled people. The RTRFE group within B and W has the ability to produce various complexly shaped fuel elements with a wide variety of fuels and enrichments. B and W RTRFE has fabricated over 200,000 plates since 1981 and gained the diversified experience necessary to satisfy many customer requirements. This accomplishment was possible with the support of McDermott International and all of its resources. B and W has always had a commitment to high quality and integrity. This is apparent by the success and longevity (125 years) of the company. A lower cost to convert cores to LEU provides direct support to RERTR and demonstrates Babcock and Wilcox's commitment to the program. As a supporter of RERTR reactor conversion from HEU to LEU, B and W has contributed a significant amount of R and D money to improve the silicide fuel process which ultimately lowers the LEU core costs. In the most recent R and D project, B and W is constructing a LEU silicide reclamation facility to re-use the unirradiated fuel scrap generated from the production process. Remanufacturing use of this fuel completes the fuel cycle and provides a contribution to LEU cores by reducing scrap inventory and handling costs, lowering initial purchase of fuel due to increasing the process yields, and lowering the replacement costs. This

  13. Leu-9 (CD 7) positivity in acute leukemias: a marker of T-cell lineage?

    Science.gov (United States)

    Ben-Ezra, J; Winberg, C D; Wu, A; Rappaport, H

    1987-01-01

    Monoclonal antibody Leu-9 (CD 7) has been reported to be a sensitive and specific marker for T-cell lineage in leukemic processes, since it is positive in patients whose leukemic cells fail to express other T-cell antigens. To test whether Leu-9 is indeed specific for T-cell leukemias, we examined in detail 10 cases of acute leukemia in which reactions were positive for Leu-9 and negative for other T-cell-associated markers including T-11, Leu-1, T-3, and E-rosettes. Morphologically and cytochemically, 2 of these 10 leukemias were classified as lymphoblastic, 4 as myeloblastic, 2 as monoblastic, 1 as megakaryoblastic, and 1 as undifferentiated. The case of acute megakaryoblastic leukemia is the first reported case to be Leu-9 positive. None of the 10 were TdT positive. Of six cases (two monoblastic, one lymphoblastic, one myeloblastic, one megakaryoblastic, and one undifferentiated) in which we evaluated for DNA gene rearrangements, only one, a peroxidase-positive leukemia, showed a novel band on study of the T-cell-receptor beta-chain gene. We therefore conclude that Leu-9 is not a specific marker to T-cell lineage and that, in the absence of other supporting data, Leu-9 positivity should not be used as the sole basis of classifying an acute leukemia as being T-cell derived.

  14. Enhanced Design Alternative I: Low Temperature Design

    International Nuclear Information System (INIS)

    MacNeil, K.

    1999-01-01

    The purpose of this document is to evaluate Enhanced Design Alternative (EDA) 1, the low temperature repository design concept (CRWMS M and O 1999a). This technical document will provide supporting information for Site Recommendation (SR) and License Application (LA). Preparation of this evaluation will be in accordance with the technical document preparation plan (TDPP), (CRWMS M and O 1999b). EDA 1, one of five EDAs, was evolved from evaluation of a series of design features and alternatives developed during the first phase of the License Application Design Selection (LADS) process. Low, medium, and high temperature concepts were developed from the design features and alternatives prepared during Phase 1 of the LADS effort (CRWMS M and O 1999a). EDA 1 will first be evaluated against a single Screening Criterion, outlined in CRWMS M and O 1999a, which addresses post-closure performance of the repository. The performance of the repository is defined quantitatively as the peak radiological dose rate to an average individual of a critical group at a distance of 20 km from the repository site within 10,000 years. To satisfy this criterion the peak dose rate must not exceed the anticipated regulatory level of 25 mrem/yr within 10,000 years. If the EDA meets the screening criterion, the EDA will be further evaluated against the LADS Phase 2 Evaluation Criteria contained in CRWMS M and O 1999a

  15. An update on the LEU target development and conversion program for the MAPLE reactors and new processing facility

    International Nuclear Information System (INIS)

    Malkoske, G.R.; Eng, B.Sc; Eng, P.

    2002-01-01

    Historically, the production of molybdenum-99 in the NRU research reactors at Chalk River, Canada, has been extracted from reactor targets employing highly enriched uranium (HEU). A reliable supply of HEU metal from the United States used in the manufacture of targets for the NRU research reactor has been a key factor to enable MDS Nordion to develop a secure supply of medical isotopes for the international nuclear medicine community. The molybdenum extraction process from HEU targets provides predictable, consistent yields for our high-volume molybdenum production process. Each link of the isotope supply chain, from isotope production to ultimate use by the physician, has been established using this proven and established method of HEU target irradiation and processing to extract molybdenum-99. To ensure a continued reliable and timely supply of medical isotopes, MDS Nordion is completing the construction of two MAPLE reactors and a New Processing Facility. The design of the MAPLE facilities was based on an established process developed by Atomic Energy of Canada Ltd. (AECL)-extraction of isotopes from HEU target material. However, in concert with the global trend to utilize low enriched uranium (LEU) in research reactors, MDS Nordion has launched a three phase LEU Target Development and Conversion Program for the MAPLE facilities. Phase 1, the Initial Feasibility Study, which identified the technical issues to convert the MAPLE reactor targets from HEU to LEU for large scale commercial production was reported on at the RERTR-2000 conference. The second phase of the LEU Target Development and Conversion Program was developed with extensive consultation and involvement of experts knowledgeable in target development, process system design, enriched uranium conversion chemistry and commercial scale reactor operations and molybdenum production. This paper will provide an overview of the Phase 2 Conversion Development Program, report on progress to date, and further

  16. Syntheses of deuterated leu-enkephalins and their use as internal standards for the quantification of leu-enkephalin by fast atom bombardment mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Benfenati, E. (Istituto di Ricerche Farmacologiche Mario Negri, Bergamo (Italy) Istituto di Ricerche Farmacologiche Mario Negri, Milan (Italy)); Icardi, G.; Chen, S. (Istituto di Ricerche Farmacologiche Mario Negri, Bergamo (Italy)); Fanelli, R. (Istituto di Ricerche Farmacologiche Mario Negri, Milan (Italy))

    1990-04-01

    We have developed a synthetic method for the preparation of di- and pentadeuterated leu-enkephalin (LE), Tyr-Gly-Gly-Phe-Leu, by proton-deuterium exchange using CF[sub 3]COOO[sup 2]H. Four to six deuterium atoms are introduced using a reaction temperature of 120[sup o]C and if 5% of [sup 2]H[sub 2]O is added the di-deuterated LE is obtained. These deuterated compounds are used as internal standards to plot calibration curves of LE using fast atom bombardment mass spectrometry. (author).

  17. A neutronic feasibility study for LEU conversion of the Brookhaven Medical Research Reactor (BMRR).

    Energy Technology Data Exchange (ETDEWEB)

    Hanan, N. A.

    1998-01-14

    A neutronic feasibility study for converting the Brookhaven Medical Research Reactor from HEU to LEU fuel was performed at Argonne National Laboratory in cooperation with Brookhaven National Laboratory. Two possible LEU cores were identified that would provide nearly the same neutron flux and spectrum as the present HEU core at irradiation facilities that are used for Boron Neutron Capture Therapy and for animal research. One core has 17 and the other has 18 LEU MTR-type fuel assemblies with uranium densities of 2.5g U/cm{sup 3} or less in the fuel meat. This LEU fuel is fully-qualified for routine use. Thermal hydraulics and safety analyses need to be performed to complete the feasibility study.

  18. Documentation Experiences for Jamaican SLOWPOKE-2 Conversion from HEU to LEU

    International Nuclear Information System (INIS)

    Warner, T.-A.; Dennis, H.; Antoine, J.

    2015-01-01

    The Jamaican SLOWPOKE–2 (JM–1) is a 20 kW research reactor manufactured by Atomic Energy of Canada Limited and has been operating since March 1984, in the department of the International Centre for Environmental and Nuclear Sciences (ICENS), at the University of the West Indies, Mona Campus in Kingston, Jamaica. The pool type reactor has been primarily used for Neutron Activation Analysis in environmental, agricultural, geochemical, health-related studies and mineral exploration. The University, assisted by the IAEA under the GTRI/RERTR program, is currently in the process of converting from HEU to LEU. Extensive documentation on policies, general requirements, elements of the conversion quality assurance (QA) system and conversion QA administrative procedures is required for the conversion. The core conversion activities are being carried out in accordance with current international standards and regulatory guidelines of the newly established Jamaican Radiation Safety Authority (RSA) with agreement between the RSA and IAEA or DOE related to Nuclear Safety and Control. The documentation structure has taken into consideration nuclear safety and licensing, LEU fuel design and conversion analysis, LEU fuel procurement and fabrication, removal of HEU fuel and reactor maintenance and conversion and commissioning, with the conversion QA manual at the apex of the structure. To a large extent, the documentation format will adhere to that of the IAEA applicable regulatory standards and guidance documents. The major challenge of the conversion activities, it is envisioned, will come from the absence of any previous regulatory framework in Jamaica; however, a timeline for the process, which includes training and equipping of regulators, will guide operation. (author)

  19. Standardization of specifications and inspection procedures for LEU plate-type research reactor fuels

    International Nuclear Information System (INIS)

    1988-06-01

    With the transition to high density uranium LEU fuel, fabrication costs of research reactor fuel elements have a tendency to increase because of two reasons. First, the amount of the powder of the uranium compound required increases by more than a factor of five. Second, fabrication requirements are in many cases nearer the fabrication limits. Therefore, it is important that measures be undertaken to eliminate or reduce unnecessary requirements in the specification or inspection procedures of research reactor fuel elements utilizing LEU. An additional stimulus for standardizing specifications and inspection procedures at this time is provided by the fact that most LEU conversions will occur within a short time span, and that nearly all of them will require preparation of new specifications and inspection procedures. In this sense, the LEU conversions offer an opportunity for improving the rationality and efficiency of the fuel fabrication and inspection processes. This report focuses on the standardization of specifications and inspection processes of high uranium density LEU fuels for research reactors. However, in many cases the results can also be extended directly to other research reactor fuels. 15 refs, 1 fig., 3 tabs

  20. The tetrapeptide Arg-Leu-Tyr-Glu inhibits VEGF-induced angiogenesis

    International Nuclear Information System (INIS)

    Baek, Yi-Yong; Lee, Dong-Keon; So, Ju-Hoon; Kim, Cheol-Hee; Jeoung, Dooil; Lee, Hansoo; Choe, Jongseon; Won, Moo-Ho; Ha, Kwon-Soo; Kwon, Young-Guen; Kim, Young-Myeong

    2015-01-01

    Kringle 5, derived from plasminogen, is highly capable of inhibiting angiogenesis. Here, we have designed and synthesized 10 tetrapeptides, based on the amino acid properties of the core tetrapeptide Lys-Leu-Tyr-Asp (KLYD) originating from anti-angiogenic kringle 5 of human plasminogen. Of these, Arg-Leu-Tyr-Glu (RLYE) effectively inhibited vascular endothelial growth factor (VEGF)-induced endothelial cell proliferation, migration and tube formation, with an IC 50 of 0.06–0.08 nM, which was about ten-fold lower than that of the control peptide KLYD (0.79 nM), as well as suppressed developmental angiogenesis in a zebrafish model. Furthermore, this peptide effectively inhibited the cellular events that precede angiogenesis, such as ERK and eNOS phosphorylation and nitric oxide production, in endothelial cells stimulated with VEGF. Collectively, these data demonstrate that RLYE is a potent anti-angiogenic peptide that targets the VEGF signaling pathway. - Highlights: • The tetrapeptide RLYE inhibited VEGF-induced angiogenesis in vitro. • RLYE also suppressed neovascularization in a zebrafish model. • Its effect was correlated with inhibition of VEGF-induced ERK and eNOS activation. • RLYE may be used as a therapeutic drug for angiogenesis-related diseases

  1. The tetrapeptide Arg-Leu-Tyr-Glu inhibits VEGF-induced angiogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Baek, Yi-Yong; Lee, Dong-Keon [Department of Molecular and Cellular Biochemistry, School of Medicine, Kangwon National University, Chuncheon, Gangwon-do, 200-702 (Korea, Republic of); So, Ju-Hoon; Kim, Cheol-Hee [Department of Biology, Chungnam National University, Daejeon, 305-764 (Korea, Republic of); Jeoung, Dooil [Department of Biochemistry, College of Natural Sciences, Kangwon National University, Chuncheon, Gangwon-do, 200-702 (Korea, Republic of); Lee, Hansoo [Department of Life Sciences, College of Natural Sciences, Kangwon National University, Chuncheon, Gangwon-do, 200-702 (Korea, Republic of); Choe, Jongseon [Department of Immunology, School of Medicine, Kangwon National University, Chuncheon, Gangwon-do, 200-702 (Korea, Republic of); Won, Moo-Ho [Department of Neurobiology, School of Medicine, Kangwon National University, Chuncheon, Gangwon-do, 200-702 (Korea, Republic of); Ha, Kwon-Soo [Department of Molecular and Cellular Biochemistry, School of Medicine, Kangwon National University, Chuncheon, Gangwon-do, 200-702 (Korea, Republic of); Kwon, Young-Guen [Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul, 120-752 (Korea, Republic of); Kim, Young-Myeong, E-mail: ymkim@kangwon.ac.kr [Department of Molecular and Cellular Biochemistry, School of Medicine, Kangwon National University, Chuncheon, Gangwon-do, 200-702 (Korea, Republic of)

    2015-08-07

    Kringle 5, derived from plasminogen, is highly capable of inhibiting angiogenesis. Here, we have designed and synthesized 10 tetrapeptides, based on the amino acid properties of the core tetrapeptide Lys-Leu-Tyr-Asp (KLYD) originating from anti-angiogenic kringle 5 of human plasminogen. Of these, Arg-Leu-Tyr-Glu (RLYE) effectively inhibited vascular endothelial growth factor (VEGF)-induced endothelial cell proliferation, migration and tube formation, with an IC{sub 50} of 0.06–0.08 nM, which was about ten-fold lower than that of the control peptide KLYD (0.79 nM), as well as suppressed developmental angiogenesis in a zebrafish model. Furthermore, this peptide effectively inhibited the cellular events that precede angiogenesis, such as ERK and eNOS phosphorylation and nitric oxide production, in endothelial cells stimulated with VEGF. Collectively, these data demonstrate that RLYE is a potent anti-angiogenic peptide that targets the VEGF signaling pathway. - Highlights: • The tetrapeptide RLYE inhibited VEGF-induced angiogenesis in vitro. • RLYE also suppressed neovascularization in a zebrafish model. • Its effect was correlated with inhibition of VEGF-induced ERK and eNOS activation. • RLYE may be used as a therapeutic drug for angiogenesis-related diseases.

  2. Safety analysis of JMTR LEU fuel core, (3)

    International Nuclear Information System (INIS)

    Tsuchida, Noboru; Shiraishi, Tadao; Takahashi, Yutaka; Inada, Seiji; Saito, Minoru; Futamura, Yoshiaki; Kitano, Kyoshiro.

    1992-10-01

    Dose analysis in the safety evaluation and the site evaluation were performed for the JMTR core conversion from MEU fuel to LEU fuel. In the safety evaluation, the effective dose equivalents for the public surrounding the site were estimated in fuel handling accident and flow blockage to coolant channel which were selected as the design basis accidents with release of radioactive fission products to the environment. In the site evaluation, the flow blockage to coolant channel was selected as siting basis events, since this accident had the possibility of spreading radioactive release. Maximum exposure doses for the public were estimated assuming large amounts of fission products to release. It was confirmed that risk of radiation exposure of the public is negligible and the siting is appropriate. (author)

  3. Seal design alternatives study

    International Nuclear Information System (INIS)

    Van Sambeek, L.L.; Luo, D.D.; Lin, M.S.; Ostrowski, W.; Oyenuga, D.

    1993-06-01

    This report presents the results from a study of various sealing alternatives for the WIPP sealing system. Overall, the sealing system has the purpose of reducing to the extent possible the potential for fluids (either gas or liquid) from entering or leaving the repository. The sealing system is divided into three subsystems: drift and panel seals within the repository horizon, shaft seals in each of the four shafts, and borehole seals. Alternatives to the baseline configuration for the WIPP seal system design included evaluating different geometries and schedules for seal component installations and the use of different materials for seal components. Order-of-magnitude costs for the various alternatives were prepared as part of the study. Firm recommendations are not presented, but the advantages and disadvantages of the alternatives are discussed. Technical information deficiencies are identified and studies are outlined which can provide required information

  4. Alternative Natural Energy Sources in Building Design.

    Science.gov (United States)

    Davis, Albert J.; Schubert, Robert P.

    This publication provides a discussion of various energy conserving building systems and design alternatives. The information presented here covers alternative space and water heating systems, and energy conserving building designs incorporating these systems and other energy conserving techniques. Besides water, wind, solar, and bio conversion…

  5. Development of technology of high density LEU dispersion fuel fabrication

    International Nuclear Information System (INIS)

    Wiencek, T.; Totev, T.

    2007-01-01

    Advanced Materials Fabrication Facilities at Argonne National Laboratory have been involved in development of LEU dispersion fuel for research and test reactors from the beginning of RERTR program. This paper presents development of technology of high density LEU dispersion fuel fabrication for full size plate type fuel elements. A brief description of Advanced Materials Fabrication Facilities where development of the technology was carried out is given. A flow diagram of the manufacturing process is presented. U-Mo powder was manufactured by the rotating electrode process. The atomization produced a U-Mo alloy powder with a relatively uniform size distribution and a nearly spherical shape. Test plates were fabricated using tungsten and depleted U-7 wt.% Mo alloy, 4043 Al and Al-2 wt% Si matrices with Al 6061 aluminum alloy for the cladding. During the development of the technology of manufacturing of full size high density LEU dispersion fuel plates special attention was paid to meet the required homogeneity, bonding, dimensions, fuel out of zone and other mechanical characteristics of the plates.

  6. The progesterone receptor Val660→Leu polymorphism and breast cancer risk

    International Nuclear Information System (INIS)

    De Vivo, Immaculata; Hankinson, Susan E; Colditz, Graham A; Hunter, David J

    2004-01-01

    Recent evidence suggests a role for progesterone in breast cancer development and tumorigenesis. Progesterone exerts its effect on target cells by interacting with its receptor; thus, genetic variations, which might cause alterations in the biological function in the progesterone receptor (PGR), can potentially contribute to an individual's susceptibility to breast cancer. It has been reported that the PROGINS allele, which is in complete linkage disequilibrium with a missense substitution in exon 4 (G/T, valine→leucine, at codon 660), is associated with a decreased risk for breast cancer. Using a nested case-control study design within the Nurses' Health Study cohort, we genotyped 1252 cases and 1660 matched controls with the use of the Taqman assay. We did not observe any association of breast cancer risk with carrying the G/T (Val660→Leu) polymorphism (odds ratio 1.10, 95% confidence interval 0.93–1.30). In addition, we did not observe an interaction between this allele and menopausal status and family history of breast cancer as reported previously. Overall, our study does not support an association between the Val660→Leu PROGINS polymorphism and breast cancer risk

  7. Association of ghrelin Leu72Met polymorphism with type 2 diabetes mellitus in Chinese population.

    Science.gov (United States)

    Liu, Jing; Liu, Jia; Tian, Li-min; Liu, Ju-xiang; Bing, Ya-jun; Zhang, Ji-ping; Wang, Yun-Fang; Zhang, Lu-yan

    2012-08-10

    Ghrelin, a novel endogenous ligand for the growth hormone secretagogue receptor, is considered to implicate the development of the type 2 diabetes mellitus (T2DM). The Leu72Met (+408C>A) polymorphism of the preproghrelin, has been linked to obesity, insulin resistance and diabetes. To investigate the distribution of ghrelin gene Leu72Met polymorphism and its association with the type 2 diabetes mellitus in Chinese population. We conducted a case-control study on 877 patients with T2DM and 864 controls, which were genotyped by the polymerase chain reaction (PCR) technique, denaturing high performance liquid chromatography (DHPLC) and DNA sequence analysis. Laboratory analyses were carried out in the hospital laboratory. No significant difference in the Leu72Met genotype distributions and allele frequency was observed between type 2 diabetes mellitus and controls (both P>0.05). The polymorphism was not associated with T2DM. However, among the T2DM group, the patients carrying Leu72Leu genotype had significantly increased levels of FPG and serum creatinine compared with variant genotypes (Leu72Met and Met72Met) (Ppolymorphism of the preproghrelin gene was not associated with T2DM in Chinese population. However, it may have some roles in the etiology of insulin resistance. Copyright © 2012 Elsevier B.V. All rights reserved.

  8. 40 CFR 60.4111 - Alternate Hg designated representative.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Alternate Hg designated representative... Times for Coal-Fired Electric Steam Generating Units Hg Designated Representative for Hg Budget Sources § 60.4111 Alternate Hg designated representative. (a) A certificate of representation under § 60.4113...

  9. Preparation and Evaluation at the Delta Opioid Receptor of a Series of Linear Leu-Enkephalin Analogues Obtained by Systematic Replacement of the Amides

    Science.gov (United States)

    2013-01-01

    Leu-enkephalin analogues, in which the amide bonds were sequentially and systematically replaced either by ester or N-methyl amide bonds, were prepared using classical organic chemistry as well as solid phase peptide synthesis (SPPS). The peptidomimetics were characterized using competition binding, ERK1/2 phosphorylation, receptor internalization, and contractility assays to evaluate their pharmacological profile over the delta opioid receptor (DOPr). The lipophilicity (LogD7.4) and plasma stability of the active analogues were also measured. Our results revealed that the last amide bond can be successfully replaced by either an ester or an N-methyl amide bond without significantly decreasing the biological activity of the corresponding analogues when compared to Leu-enkephalin. The peptidomimetics with an N-methyl amide function between residues Phe and Leu were found to be more lipophilic and more stable than Leu-enkephalin. Findings from the present study further revealed that the hydrogen-bond donor properties of the fourth amide of Leu-enkephalin are not important for its biological activity on DOPr. Our results show that the systematic replacement of amide bonds by isosteric functions represents an efficient way to design and synthesize novel peptide analogues with enhanced stability. Our findings further suggest that such a strategy can also be useful to study the biological roles of amide bonds. PMID:23650868

  10. How LeuT shapes our understanding of the mechanisms of sodium-coupled neurotransmitter transporters.

    Science.gov (United States)

    Penmatsa, Aravind; Gouaux, Eric

    2014-03-01

    Neurotransmitter transporters are ion-coupled symporters that drive the uptake of neurotransmitters from neural synapses. In the past decade, the structure of a bacterial amino acid transporter, leucine transporter (LeuT), has given valuable insights into the understanding of architecture and mechanism of mammalian neurotransmitter transporters. Different conformations of LeuT, including a substrate-free state, inward-open state, and competitive and non-competitive inhibitor-bound states, have revealed a mechanistic framework for the transport and transport inhibition of neurotransmitters. The current review integrates our understanding of the mechanistic and pharmacological properties of eukaryotic neurotransmitter transporters obtained through structural snapshots of LeuT.

  11. Preparation results for lifetime test of conversion LEU fuel in plutonium production reactors

    International Nuclear Information System (INIS)

    Vatulin, A.; Stetskiy, Yu.; Kukharkin, N.; Kalougin, A.; Gavrilov, P.; Ivanov, A.

    1999-01-01

    The program of converting Russian production reactors for the purpose to stop their plutonium fabrication is currently in progress. The program also provides for operation of these reactors under the conversion mode with using of low-enriched fuel (LEU). LEU fuel elements were developed and activities related to their preparation for reactor tests were carried out. (author)

  12. Neutronic analysis for core conversion (HEU–LEU of the low power research reactor using the MCNP4C code

    Directory of Open Access Journals (Sweden)

    Aldawahra Saadou

    2015-06-01

    Full Text Available Comparative studies for conversion of the fuel from HEU to LEU in the miniature neutron source reactor (MNSR have been performed using the MCNP4C code. The HEU fuel (UAl4-Al, 90% enriched with Al clad and LEU (UO2 12.6% enriched with zircaloy-4 alloy clad cores have been analyzed in this study. The existing HEU core of MNSR was analyzed to validate the neutronic model of reactor, while the LEU core was studied to prove the possibility of fuel conversion of the existing HEU core. The proposed LEU core contained the same number of fuel pins as the HEU core. All other structure materials and dimensions of HEU and LEU cores were the same except the increase in the radius of control rod material from 0.195 to 0.205 cm and keeping the outer diameter of the control rod unchanged in the LEU core. The effective multiplication factor (keff, excess reactivity (ρex, control rod worth (CRW, shutdown margin (SDM, safety reactivity factor (SRF, delayed neutron fraction (βeff and the neutron fluxes in the irradiation tubes for the existing and the potential LEU fuel were investigated. The results showed that the safety parameters and the neutron fluxes in the irradiation tubes of the LEU fuels were in good agreements with the HEU results. Therefore, the LEU fuel was validated to be a suitable choice for fuel conversion of the MNSR in the future.

  13. Early Site Permit Demonstration Program: Station design alternatives report

    International Nuclear Information System (INIS)

    1993-03-01

    This report provides the results of investigating the basis for including Station Design Alternatives (SDAs) in the regulatory guidance given for nuclear plant environmental reports (ERs), explains approaches or processes for evaluating SDAs at the early site permit (ESP) stage, and applies one of the processes to each of the ten systems or subsystems considered as SDAS. The key objective o this report s to demonstrate an adequate examination of alternatives can be performed without the extensive development f design data. The report discusses the Composite Suitability Approach and the Established Cutoff Approach in evaluating station design alternatives and selects one of these approaches to evaluate alternatives for each of the plant or station that were considered. Four types of ALWRs have been considered due to the availability of extensive plant data: System 80+, AP600, Advanced Boiling Reactor (ABWR), and Simplified Boiling Water Reactor (SBWR). This report demonstrates the feasibility of evaluating station design alternatives when reactor design detail has not been determined, quantitatively compares the potential ental impacts of alternatives, and focuses the ultimate selection of a alternative on cost and applicant-specific factors. The range of alternatives system is deliberately limited to a reasonable number to demonstrate the or to the three most commonly used at operating plants

  14. Design alternatives report for the cesium removal demonstration

    Energy Technology Data Exchange (ETDEWEB)

    Walker, J.F. Jr.; Youngblood, E.L.

    1995-09-01

    The Cesium Removal Demonstration (CRD) project will use liquid low-level waste (LLLW) stored in the Oak Ridge National Laboratory Melton Valley Storage Tanks to demonstrate cesium removal from sodium nitrate-based supernates. This report presents the results of a conceptual design study to scope the alternatives for conducting the demonstration at ORNL. Factors considered included (1) sorbent alternatives, (2) facility alternatives, (3) process alternatives, (4) process disposal alternatives, and (5) relative cost comparisons. Recommendations included (1) that design of the CRD system move forward based on information obtained to date from tests with Savannah River Resin, (2) that the CRD system be designed so it could use crystalline silicotitanates (CST) if an engineered form of CST becomes available prior to the CRD, (3) that the system be designed without the capability for resin regeneration, (4) that the LLLW solidification facility be used for the demonstration (5) that vitrification of the loaded resins from the CRD be demonstrated at the Savannah River Site, and (6) that permanent disposal of the loaded and/or vitrified resin at the Nevada Test Site be pursued.

  15. Design alternatives report for the cesium removal demonstration

    International Nuclear Information System (INIS)

    Walker, J.F. Jr.; Youngblood, E.L.

    1995-09-01

    The Cesium Removal Demonstration (CRD) project will use liquid low-level waste (LLLW) stored in the Oak Ridge National Laboratory Melton Valley Storage Tanks to demonstrate cesium removal from sodium nitrate-based supernates. This report presents the results of a conceptual design study to scope the alternatives for conducting the demonstration at ORNL. Factors considered included (1) sorbent alternatives, (2) facility alternatives, (3) process alternatives, (4) process disposal alternatives, and (5) relative cost comparisons. Recommendations included (1) that design of the CRD system move forward based on information obtained to date from tests with Savannah River Resin, (2) that the CRD system be designed so it could use crystalline silicotitanates (CST) if an engineered form of CST becomes available prior to the CRD, (3) that the system be designed without the capability for resin regeneration, (4) that the LLLW solidification facility be used for the demonstration (5) that vitrification of the loaded resins from the CRD be demonstrated at the Savannah River Site, and (6) that permanent disposal of the loaded and/or vitrified resin at the Nevada Test Site be pursued

  16. White Paper – Use of LEU for a Space Reactor

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-08-11

    Historically space reactors flown or designed for the U.S. and Russia used Highly Enriched Uranium (HEU) for fuel. HEU almost always produces a small and lighter reactor. Since mass increases launch costs or decreases science payloads, HEU was the natural choice. However in today’s environment, the proliferation of HEU has become a major concern for the U.S. government and hence a policy issue. In addition, launch costs are being reduced as the space community moves toward commercial launch vehicles. HEU also carries a heavy security cost to process, test, transport and launch. Together these issues have called for a re-investigation into space reactors the use Low Enriched Uranium (LEU) fuel.

  17. Calculation of mixed HEU-LEU cores for the HOR research reactor with the scale code system

    International Nuclear Information System (INIS)

    Leege, P.F.A. de; Gibcus, H.P.M.; Hoogenboom, J.E.; Vries, J.W. de

    1997-01-01

    The HOR reactor of Interfaculty Reactor Institute (IRI), Delft, The Netherlands, will be converted to use low enriched fuel (LEU) assemblies. As there are still many usable high enriched (HEU) fuel assemblies present, there will be a considerable reactor operation time with mixed cores with both HEU and LEU fuel assemblies. At IRI a comprehensive reactor physics code system and evaluated nuclear data is implemented for detailed core calculations. One of the backbones of the IRI code system is the well-known SCALE code system package. Full core calculations are performed with the diffusion theory code BOLD VENTURE, the nodal code SILWER, and the Monte Carlo code KENO Va. Results are displayed of a strategy from a HEU core to a mixed HEU-LEU core and eventually a LEU core. (author)

  18. State alternative route designations

    International Nuclear Information System (INIS)

    1989-07-01

    Pursuant to the Hazardous Materials Transportation Act (HMTA), the Department of Transportation (DOT) has promulgated a comprehensive set of regulations regarding the highway transportation of high-level radioactive materials. These regulations, under HM-164 and HM-164A, establish interstate highways as the preferred routes for the transportation of radioactive materials within and through the states. The regulations also provide a methodology by which a state may select alternative routes. First,the state must establish a ''state routing agency,'' defined as an entity authorized to use the state legal process to impose routing requirements on carriers of radioactive material (49 CFR 171.8). Once identified, the state routing agency must select routes in accordance with Large Quantity Shipments of Radioactive Materials or an equivalent routing analysis. Adjoining states and localities should be consulted on the impact of proposed alternative routes as a prerequisite of final route selection. Lastly, the states must provide written notice of DOT of any alternative route designation before the routes are deemed effective

  19. Preliminary Assessment of the Impact on Reactor Vessel dpa Rates Due to Installation of a Proposed Low Enriched Uranium (LEU) Core in the High Flux Isotope Reactor (HFIR)

    Energy Technology Data Exchange (ETDEWEB)

    Daily, Charles R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-10-01

    An assessment of the impact on the High Flux Isotope Reactor (HFIR) reactor vessel (RV) displacements-per-atom (dpa) rates due to operations with the proposed low enriched uranium (LEU) core described by Ilas and Primm has been performed and is presented herein. The analyses documented herein support the conclusion that conversion of HFIR to low-enriched uranium (LEU) core operations using the LEU core design of Ilas and Primm will have no negative impact on HFIR RV dpa rates. Since its inception, HFIR has been operated with highly enriched uranium (HEU) cores. As part of an effort sponsored by the National Nuclear Security Administration (NNSA), conversion to LEU cores is being considered for future HFIR operations. The HFIR LEU configurations analyzed are consistent with the LEU core models used by Ilas and Primm and the HEU balance-of-plant models used by Risner and Blakeman in the latest analyses performed to support the HFIR materials surveillance program. The Risner and Blakeman analyses, as well as the studies documented herein, are the first to apply the hybrid transport methods available in the Automated Variance reduction Generator (ADVANTG) code to HFIR RV dpa rate calculations. These calculations have been performed on the Oak Ridge National Laboratory (ORNL) Institutional Cluster (OIC) with version 1.60 of the Monte Carlo N-Particle 5 (MCNP5) computer code.

  20. Evaluating design alternatives using conjoint experiments in virual reality

    NARCIS (Netherlands)

    Dijkstra, J.; Leeuwen, van J.P.; Timmermans, H.J.P.

    2003-01-01

    In this paper the authors describe the design of an experiment based on conjoint measurement that explores the possibility of using the Internet to evaluate design alternatives. These design alternatives are presented as panoramic views, and preferences are measured by asking subjects which

  1. Neutronic performance of a 14 MW TRIGA reactor: LEU vs HEU fuel

    International Nuclear Information System (INIS)

    Bretscher, M.M.; Snelgrove, J.L.; Cornella, R.J.

    1983-01-01

    A primary objective of the US Reduced Enrichment Research and Test Reactor (RERTR) Program is to develop means for replacing, wherever possible, currently used highly-enriched uranium (HEU) fuel ( 235 U enrichment > 90%) with low-enriched uranium (LEU) fuel ( 235 U enrichment < 20%) without significantly degrading the performance of research and test reactors. The General Atomic Company has developed a low-enriched but high uranium content Er-U-ZrH/sub 1.6/ fuel to enable the conversion of TRIGA reactors (and others) from HEU to LEU. One possible application is to the water-moderated 14 MW TRIGA Steady State Reactor (SSR) at the Romanian Institute for Nuclear Power Reactors. The work reported here was undertaken for the purpose of comparing the neutronic performance of the SSR for HEU fuel with that for LEU fuel. In order to make these relative comparisons as valid as possible, identical methods and models were used for the neutronic calculations

  2. Alternative cover design

    International Nuclear Information System (INIS)

    1988-11-01

    The special study on Alternative Cover Designs is one of several studies initiated by the US Department of Energy (DOE) in response to the proposed US Environmental Protection Agency (EPA) groundwater standards. The objective of this study is to investigate the possibility of minimizing the infiltration of precipitation through stabilized tailings piles by altering the standard design of covers currently used on the Uranium Mill Tailings Remedial Action (UMTRA) Project. Prior. to the issuance of the proposed standards, UMTRA Project piles had common design elements to meet the required criteria, the most important of which were for radon diffusion, long-term stability, erosion protection, and groundwater protection. The standard pile covers consisted of three distinct layers. From top to bottom they were: rock for erosion protection; a sand bedding layer; and the radon barrier, usually consisting of a clayey sand material, which also functioned to limit infiltration into the tailings. The piles generally had topslopes from 2 to 4 percent and sideslopes of 20 percent

  3. Development of a chromosomally integrated metabolite-inducible Leu3p-alpha-IPM "off-on" gene switch.

    Directory of Open Access Journals (Sweden)

    Maria Poulou

    2010-08-01

    Full Text Available Present technology uses mostly chimeric proteins as regulators and hormones or antibiotics as signals to induce spatial and temporal gene expression.Here, we show that a chromosomally integrated yeast 'Leu3p-alpha-IotaRhoMu' system constitutes a ligand-inducible regulatory "off-on" genetic switch with an extensively dynamic action area. We find that Leu3p acts as an active transcriptional repressor in the absence and as an activator in the presence of alpha-isopropylmalate (alpha-IotaRhoMu in primary fibroblasts isolated from double transgenic mouse embryos bearing ubiquitously expressing Leu3p and a Leu3p regulated GFP reporter. In the absence of the branched amino acid biosynthetic pathway in animals, metabolically stable alpha-IPM presents an EC(50 equal to 0.8837 mM and fast "OFF-ON" kinetics (t(50ON = 43 min, t(50OFF = 2.18 h, it enters the cells via passive diffusion, while it is non-toxic to mammalian cells and to fertilized mouse eggs cultured ex vivo.Our results demonstrate that the 'Leu3p-alpha-IotaRhoMu' constitutes a simpler and safer system for inducible gene expression in biomedical applications.

  4. Design Alternative Evaluation No. 3: Post-Closure Ventilation

    International Nuclear Information System (INIS)

    Logan, R.C.

    1999-01-01

    The objective of this study is to provide input to the Enhanced Design Alternatives (EDA) for License Application Design Selection (LADS). Its purpose is to develop and evaluate conceptual designs for post-closure ventilation alternatives that enhance repository performance. Post-closure ventilation is expected to enhance repository performance by limiting the amount of water contacting the waste packages. Limiting the amount of water contacting the waste packages will reduce corrosion

  5. Neutronics analysis of the proposed 25-MW leu TRIGA Multipurpose Research Reactor

    International Nuclear Information System (INIS)

    Nurdin, M.; Bretscher, M.M.; Snelgrove, J.L.

    1982-01-01

    More than two years ago the government of Indonesia announced plans to purchase a research reactor for the Puspiptek Research Center in Serpong Indonesia to be used for isotope production, materials testing, neutron physics measurements, and reactor operator training. Reactors using low-enriched uranium (LEU) plate-type and rod-type fuel elements were considered. This paper deals with the neutronic evaluation of the rod-type 25-MW LEU TRIGA Multipurpose Research Reactor (MPRR) proposed by the General Atomic Company of the United States of America

  6. 31 CFR 0.104 - Designated Agency Ethics Official and Alternate Designated Agency Ethics Official.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 1 2010-07-01 2010-07-01 false Designated Agency Ethics Official and Alternate Designated Agency Ethics Official. 0.104 Section 0.104 Money and Finance: Treasury Office of the... Responsibilities § 0.104 Designated Agency Ethics Official and Alternate Designated Agency Ethics Official. The...

  7. Enhanced Access Design Alternative I Study

    International Nuclear Information System (INIS)

    Eble, G.B.

    1999-01-01

    The purpose of this document is to evaluate Enhanced Design Alternative (EDA) 1, the low temperature repository design concept (CRWMS M and O 1999a). This technical document will provide supporting information for Site Recommendation (SR) and License Application (LA). Preparation of this evaluation will be in accordance with the technical document preparation plan (TDPP), (CRWMS M and O 1999b). EDA 1, one of five EDAs, was evolved from evaluation of a series of design features and alternatives developed during the first phase of the License Application Design Selection (LADS) process. Low, medium, and high temperature concepts were developed from the design features and alternatives prepared during Phase 1 of the LADS effort (CRWMS M and O 1999a). EDA 1 will first be evaluated against a single Screening Criterion, outlined in CRWMS M and O 1999a, which addresses post-closure performance of the repository. The performance of the repository is defined quantitatively as the peak radiological dose rate to an average individual of a critical group at a distance of 20 km from the repository site within 10,000 years. To satisfy this criterion the peak dose rate must not exceed the anticipated regulatory level of 25 mrem/yr within 10,000 years. If the EDA meets the screening criterion, the EDA will be further evaluated against the LADS Phase 2 Evaluation Criteria contained in CRWMS M and O 1999a

  8. Progress in the neutronic core conversion (HEU-LEU) analysis of Ghana research reactor-1.

    Energy Technology Data Exchange (ETDEWEB)

    Anim-Sampong, S.; Maakuu, B. T.; Akaho, E. H. K.; Andam, A.; Liaw, J. J. R.; Matos, J. E.; Nuclear Engineering Division; Ghana Atomic Energy Commission; Kwame Nkrumah Univ. of Science and Technology

    2006-01-01

    The Ghana Research Reactor-1 (GHARR-1) is a commercial version of the Miniature Neutron Source Reactor (MNSR) and has operated at different power levels since its commissioning in March 1995. As required for all nuclear reactors, neutronic and thermal hydraulic analysis are being performed for the HEU-LEU core conversion studies of the Ghana Research Reactor-1 (GHARR-1) facility, which is a commercial version of the Miniature Neutron Source Reactor (MNSR). Stochastic Monte Carlo particle transport methods and tools (MCNP4c/MCNP5) were used to fine-tune a previously developed 3-D MCNP model of the GHARR-1 facility and perform neutronic analysis of the 90.2% HEU reference and candidate LEU (UO{sub 2}, U{sub 3}Si{sub 2}, U-9Mo) fresh cores with varying enrichments from 12.6%-19.75%. In this paper, the results of the progress made in the Monte Carlo neutronic analysis of the HEU reference and candidate LEU fuels are presented. In particular, a comparative performance assessment of the LEU with respect to neutron flux variations in the fission chamber and experimental irradiation channels are highlighted.

  9. Thermal analysis of LEU modified Cintichem target irradiated in TRIGA reactor

    International Nuclear Information System (INIS)

    Catana, A; Toma, C.

    2009-01-01

    Actions conceived during last years at international level for conversion of Molybdenum fabrication process from HEU to LEU targets utilization created opportunities for INR to get access to information and participating to international discussions under IAEA auspices. Concrete steps for developing fission Molybdenum technology were facilitated. Institute of Nuclear Research bringing together a number of conditions like suitable irradiation possibilities, direct communication between reactor and hot cell facility, handling capacity of high radioactive sources, and simultaneously the existence of an expanding internal market, decided to undertake the necessary steps in order to produce fission molybdenum. Over the course of last years of efforts in this direction we developed the steps for fission Molybdenum technology development based on modified Cintichem process in accordance with the Argonne National Laboratory proved methodology. Progress made by INR to heat transfer computations of annular target using is presented. An advanced thermal-hydraulic analysis was performed to estimate the heat removal capability for an enriched uranium (LEU) foil annular target irradiated in TRIGA reactor core. As a result, the present analysis provides an upper limit estimate of the LEU-foil and external target surface temperatures during irradiation in TRIGA 14 MW reactor. (authors)

  10. Mixed core conversion study with HEU and LEU fuels

    International Nuclear Information System (INIS)

    Matos, J.E.; Freese, K.E.

    1984-01-01

    The results of a mixed core study are presented for gradual replacement of HEU fuel with LEU fuel using the IAEA generic 10 MW reactor as an example. The key parameters show that the transition can be accomplished safely and economically

  11. 29 CFR 2703.2 - Designated agency ethics official and alternate designated agency ethics official.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 9 2010-07-01 2010-07-01 false Designated agency ethics official and alternate designated agency ethics official. 2703.2 Section 2703.2 Labor Regulations Relating to Labor (Continued) FEDERAL... agency ethics official and alternate designated agency ethics official. The Chairman shall appoint an...

  12. 2010 national progress report on R and D on LEU fuel and target technology in Argentina

    International Nuclear Information System (INIS)

    Balart, S.; Blaumann, H.; Cristini, P.; Gonzalez, A.G.; Gonzalez, R.; Hermida, J.D.; Lopez, M.; Mirandou, M.; Taboada, H.

    2010-01-01

    Since last RRFM meeting, CNEA has deployed several related tasks. The RA-6 MTR type reactor, converted its core from HEU to a new LEU silicide one is scaling up the power, according to a protocol requested by the national regulatory body, ARN. CNEA is deploying an intense R and D activity to fabricate both dispersed U-Mo (Al-Si matrix and Al cladding) and monolithic (Zry-4 cladding) miniplates to develop possible solutions to VHD dispersed and monolithic fuels technical problems. Some monolithic 58% enrichment U8%Mo and U10%Mo are being delivered to INL-DoE to be irradiated in ATR reactor core. A conscientious study on compound interphase formation in both cases is being carried out. CNEA, a worldwide leader on LEU technology for fission radioisotope production is providing Brazil with these radiopharmaceutical products and Egypt and Australia with the technology through INVAP SE. CNEA is also committed to improve the diffusion of LEU target and radiochemical technology for radioisotope production and target and process optimization. Future plans include: 1) Fabrication of a LEU dispersed U-Mo fuel prototype following the recommendations of the IAEA's Good Practices document, to be irradiated in a high flux reactor in the frame of the ARG/4/092 IAEA's Technical Cooperation project. 2) Development of LEU very high density monolithic and dispersed U-Mo fuel plates with Zry-4 or Al cladding as a part of the RERTR program. 3) Optimization of LEU target and radiochemical techniques for radioisotope production. (author)

  13. LAPTM4b recruits the LAT1-4F2hc Leu transporter to lysosomes and promotes mTORC1 activation.

    Science.gov (United States)

    Milkereit, Ruth; Persaud, Avinash; Vanoaica, Liviu; Guetg, Adriano; Verrey, Francois; Rotin, Daniela

    2015-05-22

    Mammalian target of rapamycin 1 (mTORC1), a master regulator of cellular growth, is activated downstream of growth factors, energy signalling and intracellular essential amino acids (EAAs) such as Leu. mTORC1 activation occurs at the lysosomal membrane, and involves V-ATPase stimulation by intra-lysosomal EAA (inside-out activation), leading to activation of the Ragulator, RagA/B-GTP and mTORC1 via Rheb-GTP. How Leu enters the lysosomes is unknown. Here we identified the lysosomal protein LAPTM4b as a binding partner for the Leu transporter, LAT1-4F2hc (SLC7A5-SLAC3A2). We show that LAPTM4b recruits LAT1-4F2hc to lysosomes, leading to uptake of Leu into lysosomes, and is required for mTORC1 activation via V-ATPase following EAA or Leu stimulation. These results demonstrate a functional Leu transporter at the lysosome, and help explain the inside-out lysosomal activation of mTORC1 by Leu/EAA.

  14. The LEU target development and conversion program for the MAPLE reactors and new processing facility

    International Nuclear Information System (INIS)

    Malkoske, G.R.

    2003-01-01

    The availability of isotope grade, Highly Enriched Uranium (HEU), from the United States for use in the manufacture of targets for molybdenum-99 production in AECL's NRU research reactor has been a key factor to enable MDS Nordion to develop a reliable, secure supply of medical isotopes for the international nuclear medicine community. The molybdenum extraction process from HEU targets is a proven and established method that has reliably produced medical isotopes for several decades. The HEU process provides predictable, consistent yields for our high-volume, molybdenum-99 production. Other medical isotopes such as I-131 and Xe-133, which play an important role in nuclear medicine applications, are also produced from irradiated HEU targets as a by-product of the molybdenum-99 process. To ensure a continued reliable and timely supply of medical isotopes, MDS Nordion is completing the commissioning of two MAPLE reactors and an associated isotope processing facility (the New Processing Facility). The new MAPLE facilities, which will be dedicated exclusively to medical isotope production, will provide an essential contribution to a secure, robust global healthcare system. Design and construction of these facilities has been based on a life cycle management philosophy for the isotope production process. This includes target irradiation, isotope extraction and waste management. The MAPLE reactors will operate with Low Enriched Uranium (LEU) fuel, a significant contribution to the objectives of the RERTR program. The design of the isotope production process in the MAPLE facilities is based on an established process - extraction of isotopes from HEU target material. This is a proven technology that has been demonstrated over more than three decades of operation. However, in support of the RERTR program and in compliance with U.S. legislation, MDS Nordion has undertaken a LEU Target Development and Conversion Program for the MAPLE facilities. This paper will provide an

  15. Preliminary investigations for technology assessment of 99Mo production from LEU [low enriched uranium] targets

    International Nuclear Information System (INIS)

    Vandegrift, G.F.; Chaiko, D.J.; Heinrich, R.R.; Kucera, E.T.; Jensen, K.J.; Poa, D.S.; Varma, R.; Vissers, D.R.

    1986-11-01

    This paper presents the results of preliminary studies on the effects of substituting low enriched uranium (LEU) for highly enriched uranium (HEU) in targets for the production of fission product 99 Mo. Issues that were addressed are: (1) purity and yield of the 99 Mo//sup 99m/Tc product, (2) fabrication of LEU targets and related concerns, and (3) radioactive waste. Laboratory experimentation was part of the efforts for issues (1) and (2); thus far, radioactive waste disposal has only been addressed in a paper study. Although the reported results are still preliminary, there is reason to be optimistic about the feasibility of utilizing LEU targets for 99 Mo production. 37 refs., 1 fig., 5 tabs

  16. Performance and economic penalties of some LEU [low enriched uranium] conversion options for the Australian Reactor HIFAR

    International Nuclear Information System (INIS)

    McCulloch, D.B.; Robinson, G.S.

    1987-01-01

    Performance calculations for the conversion of HIFAR to low enriched uranium (LEU) fuel have been extended to a wide range of 235 U loadings per fuel element. Using a simple approximate algorithm for the likely costs of LEU compared with highly enriched uranium (HEU) fuel elements, the increases in annual fuelling costs for LEU compared with HEU fuel are examined for a range of conversion options involving different performance penalties. No significant operational/safety problems were found for any of the options canvassed. (Author)

  17. Assessment of the effectiveness of the LEU Reform Rule and its implementation

    International Nuclear Information System (INIS)

    Moran, B.W.; Nations, J.O.; Hammond, G.A.

    1993-11-01

    The US Nuclear Regulatory Commission (NRC) amended its material control and accounting (MC ampersand A) requirements in 1985 for licensees possessing and using special nuclear material (SNM) of low strategic significance in quantities larger than one effective kilogram (kg). The goal of the Low-Enriched Uranium (LEU) Reform Rule (i.e., 10CFR 74.31) was to establish MC ampersand A requirements for the LEU licensees at a level consistent with the safeguards risk associated with the relatively low strategic importance of such material. The amended requirements were written in a performance-oriented manner, rather than a prescriptive one, in an effort to allow the licensees the opportunity to choose the most cost-effective means of satisfying the requirements. The LEU Reform Rule was implemented in January 1988 and the fuel cycle facilities have had sufficient experience in implementing the rule to allow a meaningful review of its effectiveness. This document provides technical analysis and recommendations to assist the NRC in making a determination if the rule is achieving its intended purpose, and if not, to make the necessary changes to accomplish this

  18. Tritium labelling of highly selective probes for. delta. -opioid receptors: ( sup 3 H)Tyr-D-Ser(O-t-Bu)-Gly-Phe-Leu-Thr(DSTBULET) and ( sup 3 H)Tyr-D-Ser(O-t-Bu)-Gly-Phe-Leu-Thr(O-t-Bu)(BUBU)

    Energy Technology Data Exchange (ETDEWEB)

    Fellion, E.; Gacel, G.; Roques, B.P. (Institut National de la Sante et de la Recherche Medicale (INSERM), 75 - Paris (France)); Roy, J.; Morgat, J.L. (CEA Centre d' Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France). Service de Biochimie)

    1990-08-01

    The introduction of bulky residue(s) in linear enkephalin-related hexapeptides represents a new approach in the design of selective probes for {delta}-opioid receptors, displaying the appropriate criteria to investigate biological and pharmacological properties of the assumed binding site ({delta}) of endogenous enkephalins. The selectivities and high affinities of Tyr-D-Ser(O-t-Bu)-Gly-Phe-Leu-Thr(DSTBULET) and especially Tyr-D-Ser(O-t-Bu)Gly-Phe-Leu-Thr(O-t-Bu) (BUBU) associated with a satisfactory resistance to peptidases, make them the most suitable {delta}-probes reported to date. In the present paper, we report the synthesis of DSTBULET and BUBU under tritiated forms with high specific radioactivities. These radio-labelled probes will enable extensive in vitro and in vivo investigations of {delta}-opioid receptors properties to be carried out. (author).

  19. Structures of LeuT in bicelles define conformation and substrate binding in a membrane-like context

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Hui; Elferich, Johannes; Gouaux, Eric (Oregon HSU)

    2012-02-13

    Neurotransmitter sodium symporters (NSSs) catalyze the uptake of neurotransmitters into cells, terminating neurotransmission at chemical synapses. Consistent with the role of NSSs in the central nervous system, they are implicated in multiple diseases and disorders. LeuT, from Aquifex aeolicus, is a prokaryotic ortholog of the NSS family and has contributed to our understanding of the structure, mechanism and pharmacology of NSSs. At present, however, the functional state of LeuT in crystals grown in the presence of n-octyl-{beta}-D-glucopyranoside ({beta}-OG) and the number of substrate binding sites are controversial issues. Here we present crystal structures of LeuT grown in DMPC-CHAPSO bicelles and demonstrate that the conformations of LeuT-substrate complexes in lipid bicelles and in {beta}-OG detergent micelles are nearly identical. Furthermore, using crystals grown in bicelles and the substrate leucine or the substrate analog selenomethionine, we find only a single substrate molecule in the primary binding site.

  20. Values-led Participatory Design as a pursuit of meaningful alternatives

    DEFF Research Database (Denmark)

    Leong, Tuck Wah; Iversen, Ole Sejer

    2015-01-01

    Participatory Design (PD) is inherently concerned with inquiring into and supporting human values when designing IT. We argue that a PD approach that is led by a focus upon participants' values can allow participants to discover meaningful alternatives -- alternative uses and alternative...... conceptualizations for IT that are particularly meaningful to them. However, how PD works with values in the design process has not been made explicit. In this paper, we aim to (i) explicate this values-led PD approach, (ii) illustrate how this approach can lead to outcomes that are meaningful alternatives, and (iii...

  1. 40 CFR 72.22 - Alternate designated representative.

    Science.gov (United States)

    2010-07-01

    ... designated representative is selected shall include a procedure for the owners and operators of the source and affected units at the source to authorize the alternate designated representative to act in lieu...) In the event of a conflict, any action taken by the designated representative shall take precedence...

  2. A neutronic feasibility study for LEU conversion of the WWR-M reactor at Gatchina

    International Nuclear Information System (INIS)

    Petrov, Yu. V.; Erykalov, A.N.; Onegin, M.S.

    2000-01-01

    In this report we present the results of computations of the full scale reactor core with HEU (90%), MEU (36%) and LEU (19.75%) fuel. The reactor computer model for the MCU RFFI Monte Carlo code includes all peculiarities of the core. Calculations show that a uranium density of 3.3gU/cm 3 of MEU (36%) fuel and 8/25gU/cm 3 of LEU (19.75%) in WWR-M5 fuel assembly (FA) geometry is required to match the fuel cycle length of the HEU (90%) case with the same end of cycle (EOEC) excess reactivity. For the equilibrium fuel cycle the fuel burnup and poisoning, the fast and thermal neutron fluxes, the reactivity worth of control rods were calculated for the reference case with HEU (90%) FA and for the MEU and LEU FA. The relative accuracy of this neutronic feasibility study of fuel enrichment reduction of the WWR-M reactor in Gatchina is sufficient to start the fabrication feasibility study of MEU (36%) WWR-M5 fuel assemblies. At the present stage of technology it seems hardly possible to manufacture LEU (19.75%) fuel elements in WWR-M5 geometry due to too high uranium density. Only a future R and D can solve the problem. (author)

  3. High plasma ghrelin protects from coronary heart disease and Leu72Leu polymorphism of ghrelin gene from cancer in healthy adults during the 19 years follow-up study.

    Science.gov (United States)

    Laurila, M; Santaniemi, M; Kesäniemi, Y A; Ukkola, O

    2014-11-01

    The aim of our investigation was to find out if ghrelin concentrations or polymorphisms predict the future risk for cardiovascular diseases and cancer in a population-based cohort initiated in 1991 (491 hypertensive and 513 control subjects). Total mortality and hospital events were followed up for 19 years. Fasting total ghrelin concentrations were determined and Arg51Gln, Leu72Met and -501 A > C polymorphisms identified. Cox regression analysis was performed. The mean value in the control cohort was 674 pg/ml whereas in the hypertensive cohort it was 661 pg/ml. The associations found suggest that in the controls the highest ghrelin quartile protected from CHD (coronary heart disease). The results were significant without or with adjustments for age, sex, smoking, systolic blood pressure and LDL cholesterol, BMI, type 2 diabetes or QUICK index. C/C variant of the promoter associated with the prevention of IHD (ischemic heart disease) in the hypertensive group (pghrelin concentration was related to protection from CHD and Leu72Leu genotype to prevention of cancer in healthy adults during the 19 years follow-up. C/C promoter protects from IHD in the hypertensive subjects. Copyright © 2014 Elsevier Inc. All rights reserved.

  4. DESIGN ALTERNATIVES ON THE LAMINATES

    Directory of Open Access Journals (Sweden)

    Gökay Nemli

    2004-04-01

    Full Text Available Wood based panel manufacturers use increasing volumes of laminates. Laminates are resistant to the water, humidity, scratch, abrasion, burning and chemicals. These products consist of printed decor papers that have been saturated with thermosetting resin. In this study, laminate types, composition form and design alternatives were investigated.

  5. The Leu72Met polymorphism of the GHRL gene prevents the development of diabetic nephropathy in Chinese patients with type 2 diabetes mellitus.

    Science.gov (United States)

    Zhuang, Langen; Li, Ming; Yu, Changhua; Li, Can; Zhao, Mingming; Lu, Ming; Zheng, Taishan; Zhang, Rong; Zhao, Weijing; Bao, Yuqian; Xiang, Kunsan; Jia, Weiping; Wang, Niansong; Liu, Limei

    2014-02-01

    The preproghrelin (GHRL) Leu72Met polymorphism (rs 696217) is associated with obesity, reduced glucose-induced insulin secretion in healthy or diabetic subjects, and reduced serum creatinine (Scr) levels in type 2 diabetes. We evaluated the association of the Leu72Met polymorphism with measures of insulin sensitivity in non-diabetic control individuals and type 2 diabetics, and whether this variation contributes to the development of diabetic nephropathy (DN) in type 2 diabetes. A case-control study was performed of 291 non-diabetic control subjects and 466 patients with type 2 diabetes, of whom 238 had DN with overt albuminuria (DN group; albuminuric excretion rate [AER] ≥ 300 mg/24 h) and 228 did not have DN, but had diabetes for more than 10 years (non-DN group). Genotyping was performed using a TaqMan PCR assay. The Leu/Leu, Leu/Met, and Met/Met genotype frequencies were significantly different between the non-DN and DN groups (p = 0.011). The frequency of the variant genotypes (Leu/Met, Met/Met) was significantly lower in the DN group than the non-DN group (23.5 vs. 36.0 %, p = 0.003). Met/Met non-diabetic control subjects had lower BMI and Scr levels and higher eGFR level than Leu/Leu or Leu/Met individuals (p GHRL Leu72Met polymorphism may help to maintain normal renal function and may protect against the development of DN by reducing albuminuria and improving renal function in Chinese patients with type 2 diabetes.

  6. SMOPY, a new NDA tool for safeguards of LEU and MOX spent fuel

    International Nuclear Information System (INIS)

    Lebrun, A.; Merelli, M.; Szabo, J.-L.; Huver, M.; Arenas-Carrasco, J.

    2001-01-01

    Upon IAEA request, the French support program to IAEA Safeguards has developed a new device for control of the irradiated LEU and MOX fuels. The Safeguards Mox Python (SMOPY) is the achievement of a 4 years R and D program supported by CEA and COGEMA in partnership with Eurisys Mesures. The SMOPY system is based on the combination of 2 NDA techniques (passive neutron and room temperature gamma spectrometry) and on line interpretation tools (automatic gamma spectrum interpretation, depletion code EVO). Through the measurement managing software, all this contributes to the fully automatic measurement, interpretation and characterization of any kind of spent fuel. The device is transportable (50 kg, 60 cm) and is composed of four parts: 1. the measurement head with one high efficiency fission chamber and a micro room temperature gamma spectrometric probe; 2. the carrier which carries the measurement head. The carrier bottom fits the racks for accurate positioning and its top fits operator's fuel moving tool; 3. the portable electronic cabinet which includes both neutron and gamma electronic cards; 4. the portable PC which gets inspectors data, controls the measurement, get measured values, interprets them and immediately provides the inspector with worthwhile info for appropriate on the field decisions. Main features of SMOPY are: Discrimination of MOX versus LEU irradiated fuels in any case (conservative case is one cycle MOX versus three cycles LEU after short cooling time); Full characterization of irradiated LEU (burnup, cooling time, Pu amounts ...); Partial Defect Test on LEU fuels. A first version of SMOPY has been tested in industrial condition during summer 2000. This tests shown a need of shielding improvement around the gamma detector. A new version has been build a will be qualified during a new field test and then the system will be ready for routine operation in IAEA and commercial delivery. After giving details about the system itself, this paper

  7. Radioactive Waste Issues related to Production of Fission-based Mo-99 by using Low Enriched Uranium (LEU)

    Energy Technology Data Exchange (ETDEWEB)

    Hassan, Muhmood ul; Ryu, Ho Jin [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2014-10-15

    In order to produce fission-based Mo-99 from research reactors, two types of targets are being used and they are highly enriched uranium (HEU) targets with {sup 235}U enrichment more than 90wt% of {sup 235}U and low enriched uranium (LEU) targets with {sup 235}U enrichment less than 20wt% of {sup 235}U. It is worth noting that medium enriched uranium i.e. 36wt% of {sup 235}U as being used in South Africa is also regarded as non-LEU from a nuclear security point of view. In order to cope with the proliferation issues, international nuclear security policy is promoting the use of LEU targets in order to minimize the civilian use of HEU. It is noteworthy that Mo-99 yield of the LEU target is less than 20% of the HEU target, which requires approximately five times more LEU targets to be irradiated and consequently results in increased volume of waste. The waste generated from fission Mo-99 production can be mainly due to: target fabrication, assembling of target, irradiation in reactor and processing of irradiated targets. During the fission of U-235 in a reactor, a large number of radionuclides with different chemical and physical properties are formed. The waste produced from these practices may be a combination of low level waste (LLW) and intermediate level waste (ILW) comprised of all three types, i.e., solid, liquid and gas. Handling and treatment of the generated waste are dependent on its form and activity. In case of the large production facility, waste storage facility should be constructed in order to limit the radiation exposures of the workers and the environment. In this study, we discuss and compare mainly the radioactive waste generated by alkaline digestion of both HEU and LEU targets to assist in planning and deciding the choice of the technology with better arrangements for proper handling and disposal of generated waste. With the use of the LEU targets in Mo-99 production facility, significant increase in liquid and solid waste has been expected.

  8. Comparison of thermohydraulic and nuclear aspects in a standard HEU core and a typical LEU core for the HFR Petten. A case study

    International Nuclear Information System (INIS)

    Pruimboom, H.; Tas, A.

    1985-01-01

    Within the framework of the RERTR program various HEU-LEU core calculations have been performed by ANL in a cooperative effort with ECN and JRC Petten. The main purpose of this work has been to gain competence in analysing HEU-LEU core conversion for high power Materials Testing Reactors and to assist in a possible HEU-LEU conversion of the HFR Petten. For reference purposes the present HFR standard core (HEU) in the 'old' vessel geometry was calculated at first. As a next step the new vessel geometry and the increased fuel weights were taken into account. Subsequently various LEU HFR core options have been analysed. Main parameters in the LEU study were the uranium loading in the meat, the fuel type, the thickness of the meat, the number of fuel plates per element and the type of burnable poison applied. Though the study has not yet been completed, one of its striking preliminary results concerns the increased power peaking in the LEU fuel elements as compared with the HEU situation. A preliminary analysis of the thermal characteristics of a typical LEU core as compared with a standard HEU core has been made and is presented in the paper. A short survey of the various HEU and LEU calculations is given. The thermal safety analysis procedure for the HFR, as based on the flow instability criterion, is clarified. Finally, the thermal comparison HEU versus LEU and the resulting conclusions are presented. (author)

  9. A mixed core conversion study with HEU and LEU fuels

    International Nuclear Information System (INIS)

    Matos, J.E.; Freese, K.E.

    1985-01-01

    The results of a mixed core study are presented for gradual replacement of HEU fuel with LEU fuel using the IAEA generic 10 MW reactor as an example. The key parameters show that the transition can be accomplished safely and economically. (author)

  10. Processing of LEU targets for 99Mo production--testing and modification of the Cintichem process

    International Nuclear Information System (INIS)

    Wu, D.; Landsberger, S.; Buchholz, B.

    1995-09-01

    Recent experimental results on testing and modification of the Cintichem process to allow substitution of low enriched uranium (LEU) for high enriched uranium (HEU) targets are presented in this report. The main focus is on 99 Mo recovery and purification by its precipitation with α-benzoin oxime. Parameters that were studied include concentrations of nitric and sulfuric acids, partial neutralization of the acids, molybdenum and uranium concentrations, and the ratio of α-benzoin oxime to molybdenum. Decontamination factors for uranium, neptunium, and various fission products were measured. Experiments with tracer levels of irradiated LEU were conducted for testing the 99 Mo recovery and purification during each step of the Cintichem process. Improving the process with additional processing steps was also attempted. The results indicate that the conversion of molybdenum chemical processing from HEU to LEU targets is possible

  11. Enhanced Design Alternative IV

    International Nuclear Information System (INIS)

    Kramer, N.E.

    1999-01-01

    This report evaluates Enhanced Design Alternative (EDA) IV as part of the second phase of the License Application Design Selection (LADS) effort. The EDA IV concept was compared to the VA reference design using criteria from the Design Input Request for LADS Phase II EDA Evaluations (CRWMS M and O 1999b) and (CRWMS M and O 1999f). Briefly, the EDA IV concept arranges the waste packages close together in an emplacement configuration known as line load. Continuous pre-closure ventilation keeps the waste packages from exceeding their 350 C cladding and 200 C (4.3.6) drift wall temperature limits. This EDA concept keeps relatively high, uniform emplacement drift temperatures (post-closure) to drive water away from the repository and thus dry out the pillars between emplacement drifts. The waste package is shielded to permit human access to emplacement drifts and includes an integral filler inside the package to reduce the amount of water that can contact the waste form. Closure of the repository is desired 50 years after first waste is emplaced. Both backfill and drip shields will be emplaced at closure to improve post-closure performance. The EDA IV concept includes more defense-in-depth layers than the VA reference design because of its backfill, drip shield, waste package shielding, and integral filler features. These features contribute to the low dose-rate to the public achieved during the first 10,000 years of repository life as shown in Figure 3. Investigation of the EDA IV concept has led to the following general conclusions: (1) The total life cycle cost for EDA IV is about $21.7 billion which equates to a $11.3 billion net present value (both figures rounded up). (2) The incidence of design basis events for EDA IV is similar to the VA reference design. (3) The emplacement of the waste packages in drifts will be similar to the VA reference design. However, heavier equipment may be required because the shielded waste package will be heavier. (4) The heavier

  12. Preproghrelin Leu72Met polymorphism predicts a lower rate of developing renal dysfunction in type 2 diabetic nephropathy.

    Science.gov (United States)

    Lee, Dae-Yeol; Kim, Sun-Young; Jo, Dae-Sun; Hwang, Pyoung Han; Kang, Kyung Pyo; Lee, Sik; Kim, Won; Park, Sung Kwang

    2006-07-01

    Ghrelin is a novel peptide hormone, which exerts somatotropic, orexigenic and adipogenic effects. Recent studies have shown that the preproghrelin Leu72Met polymorphism is associated with serum creatinine (Scr) concentration in type 2 diabetes; 72Met carriers exhibited lower Scr levels as compared with the 72Met non-carriers. We hypothesized that the preproghrelin Leu72Met polymorphism is associated with a lower rate of developing renal dysfunction in patients with type 2 diabetic nephropathy. The preproghrelin Leu72Met polymorphism was investigated using PCR techniques in 138 patients with diabetic nephropathy divided into two groups, one with normal renal function and the other with renal dysfunction. Determination of the frequency of the preproghrelin Leu72Met polymorphism was the main outcome measure. The frequency of the Leu72Met polymorphism in diabetic nephropathy was significantly lower in patients with renal dysfunction (15.9%, P polymorphism was also associated with serum total cholesterol levels in diabetic nephropathy patients with renal dysfunction; the 72Met carriers had lower total cholesterol levels than the 72Met non-carriers (P < 0.05). These data suggest that 72Met carrier status may be used as a marker predicting a lower chance of developing renal dysfunction in diabetic nephropathy.

  13. Status of LEU fuel development and conversion of NRU

    International Nuclear Information System (INIS)

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

    1991-01-01

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

  14. Criticality Calculations of Fresh LEU and MOX Assemblies for Transport and Storage at the Balakovo Nuclear Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Goluoglu, S.

    2001-01-11

    Transportation of low-enriched uranium (LEU) and mixed-oxide (MOX) assemblies to and within the VVER-1000-type Balakovo Nuclear Power Plant is investigated. Effective multiplication factors for fresh fuel assemblies on the railroad platform, fresh fuel assemblies in the fuel transportation vehicle, and fresh fuel assemblies in the spent fuel storage pool are calculated. If there is no absorber between the units, the configurations with all MOX assemblies result in higher effective multiplication factors than the configurations with all LEU assemblies when the system is dry. When the system is flooded, the configurations with all LEU assemblies result in higher effective multiplication factors. For normal operating conditions, effective multiplication factors for all configurations are below the presumed upper subcritical limit of 0.95. For an accident condition of a fully loaded fuel transportation vehicle that is flooded with low-density water (possibly from a fire suppression system), the presumed upper subcritical limit is exceeded by configurations containing LEU assemblies.

  15. Associations of Leu72Met Polymorphism of Preproghrelin with Ratios of Plasma Lipids Are Diversified by a High-Carbohydrate Diet in Healthy Chinese Adolescents.

    Science.gov (United States)

    Su, Mi; Qiu, Li; Wang, Qian; Jiang, Zhen; Liu, Xiao Juan; Lin, Jia; Fang, Ding Zhi

    2015-01-01

    The association of preproghrelin Leu72Met polymorphism with plasma lipids profile was inconsistently reported and needs more studies to be confirmed. Our study was to investigate the changes of plasma lipids ratios after a high-carbohydrate (high-CHO) diet in healthy Chinese adolescents with different genotypes of this polymorphism. Fifty-three healthy university students were given a washout diet of 54.1% carbohydrate for 7 days, followed by a high-CHO diet of 70.1% carbohydrate for 6 days. The anthropometric and biological parameters were analyzed at baseline and before and after the high-CHO diet. When compared with those before the high-CHO diet, body mass index (BMI) decreased in the male and female Met72 allele carriers. Decreased low-/high-density lipoprotein cholesterol (LDL-C/HDL-C) was observed in all participants except the female subjects with the Leu72Leu genotype. TG/HDL-C and log (TG/HDL-C) were increased only in the female subjects with the Leu72Leu genotype. These results suggest that the Met72 allele of preproghrelin Leu72Met polymorphism may be associated with decreased BMI induced by the high-CHO diet in male and female adolescents, while the Leu72 allele with increased TG/HDL-C and log (TG/HDL-C) in the female adolescents only. Furthermore, the decreasing effect of the high-CHO diet on LDL/HDL-C may be eliminated in the female Leu72Leu homozygotes. © 2015 S. Karger AG, Basel.

  16. Establishing a LEU MTR fuel manufacturing facility in South Africa

    International Nuclear Information System (INIS)

    Jamie, R.W.; Kocher, A.

    2010-01-01

    The South African MTR Fuel Manufacturing Facility was established in the 1970's to supply SAFARI-1 with Fuel Elements and Control Rods. South African capability was developed in parallel with the uranium enrichment program to meet the needs of the Reactor. Further to the July 2005 decision by the South African Governmnent to convert both SAFARI-1 and the Fuel Plant to LEU, the SAFARI-1 phase has been successfully completed and Necsa has commenced with the conversion of the MTR Fuel Manufacturing Facility. In order to establish, validate and qualify the facility, Necsa has entered into a co-operation and technology transfer agreement with AREVA CERCA, the French manufacturer of Research Reactor fuel elements. Past experiences, conversion challenges and the status of the MTR Fuel Facility Project are discussed. On-going co-operation with AREVA CERCA to implement the local manufacture of LEU fuel is explained and elaborated on. (author)

  17. Low-Enriched Uranium Fuel Design with Two-Dimensional Grading for the High Flux Isotope Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Ilas, Germina [ORNL; Primm, Trent [ORNL

    2011-05-01

    An engineering design study of the conversion of the High Flux Isotope Reactor (HFIR) from high-enriched uranium (HEU) to low-enriched uranium (LEU) fuel is ongoing at Oak Ridge National Laboratory. The computational models developed during fiscal year 2010 to search for an LEU fuel design that would meet the requirements for the conversion and the results obtained with these models are documented and discussed in this report. Estimates of relevant reactor performance parameters for the LEU fuel core are presented and compared with the corresponding data for the currently operating HEU fuel core. The results obtained indicate that the LEU fuel design would maintain the current performance of the HFIR with respect to the neutron flux to the central target region, reflector, and beam tube locations under the assumption that the operating power for the reactor fueled with LEU can be increased from the current value of 85 MW to 100 MW.

  18. Analytical analyses of startup measurements associated with the first use of LEU fuel in Romania's 14-MW TRIGA reactor

    International Nuclear Information System (INIS)

    Bretscher, M.M.; Snelgrove, J.L.; Ciocanescu, M.

    1992-01-01

    The 14-MW TRIGA steady state reactor (SSR) is located in Pitesti, Romania. Beginning with an HEU core (10 wt% U), the reactor first went critical in November 1979 but was shut down ten years later because of insufficient excess reactivity. Last November the Institute for Nuclear Research (INR), which operates the SSR, received from the ANL RERTR program a shipment of 125 LEU pins fabricated by General Atomics and of the same geometry as the original fuel but with an enrichment of 19.7% 235U and a loading of 45 wt% U. Using 100 of these pins, four LEU clusters, each containing a 5 x 5 square array of fuel rods, were assembled. These four LEU clusters replaced the four most highly burned HEU elements in the SSR. The reactor resumed operations last February with a 35-element mixed HEU/LEU core configuration. In preparation for full power operation of the SSR with this mixed HEU/LEU core, a number of measurements were made. These included control rod calibrations, excess reactivity determinations, worths of experiment facilities, reaction rate distributions, and themocouple measurements of fuel temperatures as a function of reactor power. This paper deals with a comparison of some of these measured reactor parameters with corresponding analytical calculations

  19. LEU-fueled SLOWPOKE-2 modelling with MCNP4A

    International Nuclear Information System (INIS)

    Pierre, J.R.M.; Bonin, H.W.J.

    1996-01-01

    Following the commissioning of the Low Enrichment Uranium (LEU) Fueled SLOWPOKE-2 research reactor at Royal Military College,excess reactivity measurements were conducted over a range of temperature and power. Given the advance in computer technology, the use of Monte Carlo N-Particle Transport Code System MCNP 4A appeared possible for the simulation of the LEU-fueled SLOWPOKE-2 reactor core, and this work demonstrates that this is indeed the case. MCNP 4A is a full three dimensional program allowing the user to enter a large amount of complexity. The limit on the geometry complexity is the computing time required to achieve a reasonable standard deviation. To this point several models of the SLOWPOKE-2 have been developed giving some insight on the sensitivity of the code. MCNP4A can use various cross section libraries. The aim of this work is to calculate accurately the reactivity of the core and reproduce The temperature trend of the reactivity. The model preserved as much as possible the details of the core and facility in order to allow further study in the flux mapping

  20. Greek research reactor performance characteristics after addition of beryllium reflector and LEU fuel

    International Nuclear Information System (INIS)

    Deen, J.R.; Snelgrove, J.L.; Papastergiou, C.

    1992-01-01

    The GRR-1 is a 5-MW pool-type, light-water-moderated and-cooled reactor fueled with MTR-type fuel elements. Recently received Be reflector blocks will soon be added to the core to add additional reactivity until fresh LEU fuel arrives. REBUS-3 xy fuel cycle analyses, using burnup dependent cross sections, were performed to assist in fuel management decisions for the water- and Be-reflected HEU nonequilibrium cores. Cross sections generated by EPRI-CELL have been benchmarked to identical VIM Monte Carlo models. The size of the Be-reflected LEU core has been reduced to 30 elements compared to 35 for the HEU water-reflected core, and an equilibrium cycle calculation has been performed

  1. Fuel element burnup determination in HEU-LEU mixed TRIGA research reactor core

    International Nuclear Information System (INIS)

    Zagar, Tomaz; Ravnik, Matjaz

    2000-01-01

    This paper presents the results of a burnup calculations and burnup measurements for TRIGA FLIP HEU fuel elements and standard TRIGA LEU fuel elements used simultaneously in small TRIGA Mark II research reactor in Ljubljana, Slovenija. The fuel element burnup for approximately 15 years of operation was calculated with two different in house computer codes TRIGAP and TRIGLAV (both codes are available at OECD NEA Data Bank). The calculation is performed in one-dimensional radial geometry in TRIGAP and in two-dimensional (r,φ) geometry in TRIGLAV. Inter-comparison of results shows important influence of in-core water gaps, irradiation channels and mixed rings on burnup calculation accuracy. Burnup of 5 HEU and 27 LEU fuel elements was also measured with reactivity method. Measured and calculated burnup values are inter-compared for these elements (author)

  2. Alternate design of ITER cryostat skirt support system

    International Nuclear Information System (INIS)

    Pandey, Manish Kumar; Gupta, Girish Kumar; Bhardwaj, Anil Kumar; Jha, Saroj Kumar

    2015-01-01

    The skirt support of ITER cryostat is a support system which takes all the load of cryostat cylinder and dome during normal and operational condition. The present design of skirt support has full penetration weld joints at the bottom (shell to horizontal plate joint). To fulfill the requirements of tolerances and control the welding distortions, we have proposed to change the full penetration weld into fillet weld. A detail calculation is done to check the feasibility and structural impact due to proposed design. The calculations provide the size requirements of fillet weld. To verify the structural integrity during most severe load case, finite element analysis (FEA) has been done in line with ASME section VIII division 2. By FEA 'Plastic Collapse' and 'Local Failure' modes has been assessed. 5° sector of skirt clamp has been modeled in CATIA V5 R21 and used in FEA. Fillet weld at shell to horizontal plate joint has been modeled and symmetry boundary condition at ± 2.5° applied. 'Elastic Plastic Analysis' has been performed for the most severe loading case i.e. Category IV loading. The alternate design of Cryostat Skirt support system has been found safe by analysis against Plastic collapse and Local Failure Modes with load proportionality factor 2.3. Alternate design of Cryostat skirt support system has been done and validated by FEA. As per alternate design, the proposal of fillet weld has been implemented in manufacturing. (author)

  3. Design analysis of engineered alternatives for the Waste Isolation Pilot Plant

    International Nuclear Information System (INIS)

    Myers, J.; Djordjevic, S.; Adams, M.; Spangler, L.; Valdez, J.; Vetter, D.; Drez, P.

    1991-01-01

    The effectiveness of several engineered alternatives, designed to enhance the performance of the Waste Isolation Pilot Plant (WIPP), were evaluated relative to the performance of the baseline design. This evaluation was performed using a computer program referred to as the Design Analysis Model which couples salt creep closure, brine inflow, gas generation and dissipation to realistically simulate these interrelated processes over a 10,000 year period following the decommissioning of the repository. Analyses of the baseline design and nine alternative designs were performed for the undisturbed repository conditions, as well as three human intrusion events. Improvements in repository performance of up to four orders of magnitude were predicted for various engineered alternative waste forms. 6 refs., 8 figs., 1 tab

  4. Waste Treatment of Acidic Solutions from the Dissolution of Irradiated LEU Targets for 99-Mo Production

    Energy Technology Data Exchange (ETDEWEB)

    Bakel, Allen J. [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Conner, Cliff [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Quigley, Kevin [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Vandegrift, George F. [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division

    2016-10-01

    One of the missions of the Reduced Enrichment for Research and Test Reactors (RERTR) program (and now the National Nuclear Security Administrations Material Management and Minimization program) is to facilitate the use of low enriched uranium (LEU) targets for 99Mo production. The conversion from highly enriched uranium (HEU) to LEU targets will require five to six times more uranium to produce an equivalent amount of 99Mo. The work discussed here addresses the technical challenges encountered in the treatment of uranyl nitrate hexahydrate (UNH)/nitric acid solutions remaining after the dissolution of LEU targets. Specifically, the focus of this work is the calcination of the uranium waste from 99Mo production using LEU foil targets and the Modified Cintichem Process. Work with our calciner system showed that high furnace temperature, a large vent tube, and a mechanical shield are beneficial for calciner operation. One- and two-step direct calcination processes were evaluated. The high-temperature one-step process led to contamination of the calciner system. The two-step direct calcination process operated stably and resulted in a relatively large amount of material in the calciner cup. Chemically assisted calcination using peroxide was rejected for further work due to the difficulty in handling the products. Chemically assisted calcination using formic acid was rejected due to unstable operation. Chemically assisted calcination using oxalic acid was recommended, although a better understanding of its chemistry is needed. Overall, this work showed that the two-step direct calcination and the in-cup oxalic acid processes are the best approaches for the treatment of the UNH/nitric acid waste solutions remaining from dissolution of LEU targets for 99Mo production.

  5. Highly efficient residue-selective labeling with isotope-labeled Ile, Leu, and Val using a new auxotrophic E. coli strain

    International Nuclear Information System (INIS)

    Miyanoiri, Yohei; Ishida, Yojiro; Takeda, Mitsuhiro; Terauchi, Tsutomu; Inouye, Masayori; Kainosho, Masatsune

    2016-01-01

    We recently developed a practical protocol for preparing proteins bearing stereo-selectively 13 C-methyl labeled leucines and valines, instead of the commonly used 13 C-methyl labeled precursors for these amino acids, by E. coli cellular expression. Using this protocol, proteins with any combinations of isotope-labeled or unlabeled Leu and Val residues were prepared, including some that could not be prepared by the precursor methods. However, there is still room for improvement in the labeling efficiencies for Val residues, using the methods with labeled precursors or Val itself. This is due to the fact that the biosynthesis of Val could not be sufficiently suppressed, even by the addition of large amounts of Val or its precursors. In this study, we completely solved this problem by using a mutant strain derived from E. coli BL21(DE3), in which the metabolic pathways depending on two enzymes, dihydroxy acid dehydratase and β-isopropylmalate dehydrogenase, are completely aborted by deleting the ilvD and leuB genes, which respectively encode these enzymes. The ΔilvD E. coli mutant terminates the conversion from α,β-dihydroxyisovalerate to α-ketoisovalerate, and the conversion from α,β-dihydroxy-α-methylvalerate to α-keto-β-methylvalerate, which produce the preceding precursors for Val and Ile, respectively. By the further deletion of the leuB gene, the conversion from Val to Leu was also fully terminated. Taking advantage of the double-deletion mutant, ΔilvDΔleuB E. coli BL21(DE3), an efficient and residue-selective labeling method with various isotope-labeled Ile, Leu, and Val residues was established.

  6. Highly efficient residue-selective labeling with isotope-labeled Ile, Leu, and Val using a new auxotrophic E. coli strain

    Energy Technology Data Exchange (ETDEWEB)

    Miyanoiri, Yohei [Nagoya University, Structural Biology Research Center, Graduate School of Science (Japan); Ishida, Yojiro [Rutgers University-Robert Wood Johnson Medical School, Center for Advanced Biotechnology and Medicine (United States); Takeda, Mitsuhiro [Nagoya University, Structural Biology Research Center, Graduate School of Science (Japan); Terauchi, Tsutomu [Tokyo Metropolitan University, Graduate School of Science and Engineering (Japan); Inouye, Masayori [Rutgers University-Robert Wood Johnson Medical School, Center for Advanced Biotechnology and Medicine (United States); Kainosho, Masatsune, E-mail: kainosho@tmu.ac.jp [Nagoya University, Structural Biology Research Center, Graduate School of Science (Japan)

    2016-06-15

    We recently developed a practical protocol for preparing proteins bearing stereo-selectively {sup 13}C-methyl labeled leucines and valines, instead of the commonly used {sup 13}C-methyl labeled precursors for these amino acids, by E. coli cellular expression. Using this protocol, proteins with any combinations of isotope-labeled or unlabeled Leu and Val residues were prepared, including some that could not be prepared by the precursor methods. However, there is still room for improvement in the labeling efficiencies for Val residues, using the methods with labeled precursors or Val itself. This is due to the fact that the biosynthesis of Val could not be sufficiently suppressed, even by the addition of large amounts of Val or its precursors. In this study, we completely solved this problem by using a mutant strain derived from E. coli BL21(DE3), in which the metabolic pathways depending on two enzymes, dihydroxy acid dehydratase and β-isopropylmalate dehydrogenase, are completely aborted by deleting the ilvD and leuB genes, which respectively encode these enzymes. The ΔilvD E. coli mutant terminates the conversion from α,β-dihydroxyisovalerate to α-ketoisovalerate, and the conversion from α,β-dihydroxy-α-methylvalerate to α-keto-β-methylvalerate, which produce the preceding precursors for Val and Ile, respectively. By the further deletion of the leuB gene, the conversion from Val to Leu was also fully terminated. Taking advantage of the double-deletion mutant, ΔilvDΔleuB E. coli BL21(DE3), an efficient and residue-selective labeling method with various isotope-labeled Ile, Leu, and Val residues was established.

  7. Facility safeguards at an LEU fuel fabrication facility in Japan

    International Nuclear Information System (INIS)

    Kuroi, H.; Osabe, T.

    1984-01-01

    A facility description of a Japanese LEU BWR-type fuel fabrication plant focusing on safeguards viewpoints is presented. Procedures and practices of MC and A plan, measurement program, inventory taking, and the report and record system are described. Procedures and practices of safeguards inspection are discussed and lessons learned from past experiences are reviewed

  8. Fission product release from TRIGA-LEU reactor fuels

    International Nuclear Information System (INIS)

    Baldwin, N.L.; Foushee, F.C.; Greenwood, J.S.

    1980-01-01

    Due to present international concerns over nuclear proliferation, TRIGA reactor fuels will utilize only low-enriched uranium (LEU) (enrichment <20%). This requires increased total uranium loading per unit volume of fuel in order to maintain the appropriate fissile loading. Tests were conducted to determine the fractional release of gaseous and metallic fission products from typical uranium-zirconium hydride TRIGA fuels containing up to 45 wt-% uranium. These tests, performed in late 1977 and early 1978, were similar to those conducted earlier on TRIGA fuels with 8.5 wt-% U. Fission gas release measurements were made on prototypic specimens from room temperature to 1100 deg. C in the TRIGA King Furnace Facility. The fuel specimens were irradiated in the TRIGA reactor at a low power level. The fractional releases of the gaseous nuclides of krypton and xenon were measured under steady-state operating conditions. Clean helium was used to sweep the fission gases released during irradiation from the furnace into a standard gas collection trap for gamma counting. The results of these tests on TRIGA-LEU fuel agree well with data from the similar, earlier tests on TRIGA fuel. The correlation used to calculate the release of fission products from 8.5 wt-% U TRIGA fuel applies equally well for U contents up to 45 wt-%. (author)

  9. Alternative design concept for the second Glass Waste Storage Building

    International Nuclear Information System (INIS)

    Rainisch, R.

    1992-10-01

    This document presents an alternative design concept for storing canisters filled with vitrified waste produced at the Defense Waste Processing Facility (DWPF). The existing Glass Waste Storage Building (GWSB1) has the capacity to store 2,262 canisters and is projected to be completely filled by the year 2000. Current plans for glass waste storage are based on constructing a second Glass Waste Storage Building (GWSB2) once the existing Glass Waste Storage Building (GWSB1) is filled to capacity. The GWSB2 project (Project S-2045) is to provide additional storage capacity for 2,262 canisters. This project was initiated with the issue of a basic data report on March 6, 1989. In response to the basic data report Bechtel National, Inc. (BNI) prepared a draft conceptual design report (CDR) for the GWSB2 project in April 1991. In May 1991 WSRC Systems Engineering issued a revised Functional Design Criteria (FDC), the Rev. I document has not yet been approved by DOE. This document proposes an alternative design for the conceptual design (CDR) completed in April 1991. In June 1992 Project Management Department authorized Systems Engineering to further develop the proposed alternative design. The proposed facility will have a storage capacity for 2,268 canisters and will meet DWPF interim storage requirements for a five-year period. This document contains: a description of the proposed facility; a cost estimate of the proposed design; a cost comparison between the proposed facility and the design outlined in the FDC/CDR; and an overall assessment of the alternative design as compared with the reference FDC/CDR design

  10. Reliability analysis of the Chinese version of the Functional Assessment of Cancer Therapy - Leukemia (FACT-Leu) scale based on multivariate generalizability theory.

    Science.gov (United States)

    Meng, Qiong; Yang, Zheng; Wu, Yang; Xiao, Yuanyuan; Gu, Xuezhong; Zhang, Meixia; Wan, Chonghua; Li, Xiaosong

    2017-05-04

    The Functional Assessment of Cancer Therapy-Leukemia (FACT-Leu) scale, a leukemia-specific instrument for determining the health-related quality of life (HRQOL) in patients with leukemia, had been developed and validated, but there have been no reports on the development of a simplified Chinese version of this scale. This is a new exploration to analyze the reliability of the HRQOL measurement using multivariate generalizability theory (MGT). This study aimed to develop a Chinese version of the FACT-Leu scale and evaluate its reliability using MGT to provide evidence to support the revision and improvement of this scale. The Chinese version of the FACT-Leu scale was developed by four steps: forward translation, backward translation, cultural adaptation and pilot-testing. The HRQOL was measured for eligible inpatients with leukemia using this scale to provide data. A single-facet multivariate Generalizability Study (G-study) design was demonstrated to estimate the variance-covariance components and then several Decision Studies (D-studies) with varying numbers of items were analyzed to obtain reliability coefficients and to understand how much the measurement reliability could be vary as the number of items in MGT changes. One-hundred and one eligible inpatients diagnosed with leukemia were recruited and completed the HRQOL measurement at the time of admission to the hospital. In the G-study, the variation component of the patient-item interaction was largest while the variation component of the item was the smallest for the four of five domains, except for the leukemia-specific (LEUS) domain. In the D-study, at the level of domain, the generalizability coefficients (G) and the indexes of dependability (Ф) for four of the five domains were approximately equal to or greater than 0.80 except for the Emotional Well-being (EWB) domain (>0.70 but number of items were obtained: one is a 37-item version while the other is a 45-item version. The Chinese version of the FACT-Leu

  11. Verification of maximum radial power peaking factor due to insertion of FPM-LEU target in the core of RSG-GAS reactor

    Energy Technology Data Exchange (ETDEWEB)

    Setyawan, Daddy, E-mail: d.setyawan@bapeten.go.id [Center for Assessment of Regulatory System and Technology for Nuclear Installations and Materials, Indonesian Nuclear Energy Regulatory Agency (BAPETEN), Jl. Gajah Mada No. 8 Jakarta 10120 (Indonesia); Rohman, Budi [Licensing Directorate for Nuclear Installations and Materials, Indonesian Nuclear Energy Regulatory Agency (BAPETEN), Jl. Gajah Mada No. 8 Jakarta 10120 (Indonesia)

    2014-09-30

    Verification of Maximum Radial Power Peaking Factor due to insertion of FPM-LEU target in the core of RSG-GAS Reactor. Radial Power Peaking Factor in RSG-GAS Reactor is a very important parameter for the safety of RSG-GAS reactor during operation. Data of radial power peaking factor due to the insertion of Fission Product Molybdenum with Low Enriched Uranium (FPM-LEU) was reported by PRSG to BAPETEN through the Safety Analysis Report RSG-GAS for FPM-LEU target irradiation. In order to support the evaluation of the Safety Analysis Report incorporated in the submission, the assessment unit of BAPETEN is carrying out independent assessment in order to verify safety related parameters in the SAR including neutronic aspect. The work includes verification to the maximum radial power peaking factor change due to the insertion of FPM-LEU target in RSG-GAS Reactor by computational method using MCNP5and ORIGEN2. From the results of calculations, the new maximum value of the radial power peaking factor due to the insertion of FPM-LEU target is 1.27. The results of calculations in this study showed a smaller value than 1.4 the limit allowed in the SAR.

  12. Conversion and start up of Tehran Research Reactor with LEU fuel

    International Nuclear Information System (INIS)

    Zaker, M.

    2004-01-01

    The MW Tehran Research Reactor, Highly Enriched Uranium (HEU) fuel has been converted to Low Enriched Uranium (LEU) fuel using U 3 0 8 -Al with less than 20% enriched uranium. Measured value of excess reactivity, control rod worth and other parameters indicate good agreement with computational predictions. (author)

  13. Key considerations in the conversion to LEU of a Mo-99 commercially producing reactor: SAFARI-1 of South Africa

    International Nuclear Information System (INIS)

    Stumpf, W.E.; Vermaak, A.P.; Ball, G.

    2000-01-01

    Apart from the technological demands and considerations associated with the conversion of a Mo-99 commercially producing reactor to LEU, a number of commercial challenges also need to be addressed. This is particularly the case when the reactor is primarily used as a source for the production, on an uninterrupted basis, of significant quantities of Mo-99 to satisfy long term commitments to a range of global customers. This paper highlights key business considerations which are applicable in the conversion process of firstly, reactor fuel to LEU and secondly target plates for Mo-99, also to LEU, using the SAFARI-1 reactor in South Africa as a typical example of such a commercially utilized reactor. (author)

  14. Key considerations in the conversion to LEU of a Mo-99 commercially producing reactor: SAFARI-1 of South Africa

    Energy Technology Data Exchange (ETDEWEB)

    Stumpf, W E; Vermaak, A P; Ball, G [NECSA, PO Box 582, Pretoria (South Africa)

    2000-10-01

    Apart from the technological demands and considerations associated with the conversion of a Mo-99 commercially producing reactor to LEU, a number of commercial challenges also need to be addressed. This is particularly the case when the reactor is primarily used as a source for the production, on an uninterrupted basis, of significant quantities of Mo-99 to satisfy long term commitments to a range of global customers. This paper highlights key business considerations which are applicable in the conversion process of firstly, reactor fuel to LEU and secondly target plates for Mo-99, also to LEU, using the SAFARI-1 reactor in South Africa as a typical example of such a commercially utilized reactor. (author)

  15. The Leu72Met polymorphism of the ghrelin gene is associated with a decreased risk for type 2 diabetes.

    Science.gov (United States)

    Berthold, Heiner K; Giannakidou, Eleni; Krone, Wilhelm; Mantzoros, Christos S; Gouni-Berthold, Ioanna

    2009-01-01

    Ghrelin is involved in several metabolic and cardiovascular processes. The Leu72Met polymorphism of its gene was associated with an increased risk of type 2 diabetes (DM2) in some, but not all studies. Its association with atherosclerosis is not known. We investigated 420 Caucasian subjects with DM2 and 430 controls without diabetes (56.6% male, age 62+/-10 years). The Leu72Leu genotype frequencies were 89.76/84.65%, the Leu72Met 9.52/15.12% and the Met72Met 0.71/0.23% (P=0.029) in the DM2 and controls groups, respectively. In subjects with Met72+ genotypes the risk of DM2 was significantly decreased (univariate OR 0.63, 95% CI 0.42-0.95, P=0.026). In a logistic regression model, body mass index, hypertension and a positive family history for diabetes were predictors of diabetes while the polymorphism remained negatively associated with the disease (OR 0.62, 95% CI 0.40-0.97, P=0.036). After adjusting for known risk factors for atherosclerosis, the Met72+ variant was not associated with atherosclerotic disease (OR 1.41, 95% CI 0.78-2.54, P=0.25). Ghrelin concentrations were not associated with the polymorphism, DM2 or atherosclerotic disease. The Leu72Met polymorphism of the ghrelin gene is associated with a decreased risk for DM2. There is no association between the variant and atherosclerotic disease or ghrelin concentrations.

  16. Lessons learned by southern states in designating alternative routes

    International Nuclear Information System (INIS)

    1989-08-01

    The purpose of this report is to discuss the ''lessons learned'' by the five states within the southem region that have designated alternative or preferred routes under the regulations of the Department of Transportation (DOT) established for the transportation of radioactive materials. The document was prepared by reviewing applicable federal laws and regulations, examining state reports and documents and contacting state officials and routing agencies involved in making routing decisions. In undertaking this project, the Southern States Energy Board hopes to reveal the process used by states that have designated alternative routes and thereby share their experiences (i.e., lessons learned) with other southern states that have yet to make designations. Under DOT regulations (49 CFR 177.826), carriers of highway route controlled quantities of radioactive materials (which include spent nuclear fuel and high-level waste) must use preferred routes selected to reduce time in transit. Such preferred routes consist of (1) an interstate system highway with use of an interstate system bypass or beltway around cities when available, and (2) alternate routes selected by a ''state routing agency.''

  17. Dysregulated autophagy in restrictive cardiomyopathy due to Pro209Leu mutation in BAG3.

    Science.gov (United States)

    Schänzer, A; Rupp, S; Gräf, S; Zengeler, D; Jux, C; Akintürk, H; Gulatz, L; Mazhari, N; Acker, T; Van Coster, R; Garvalov, B K; Hahn, A

    2018-03-01

    Myofibrillary myopathies (MFM) are hereditary myopathies histologically characterized by degeneration of myofibrils and aggregation of proteins in striated muscle. Cardiomyopathy is common in MFM but the pathophysiological mechanisms are not well understood. The BAG3-Pro209Leu mutation is associated with early onset MFM and severe restrictive cardiomyopathy (RCM), often necessitating heart transplantation during childhood. We report on a young male patient with a BAG3-Pro209Leu mutation who underwent heart transplantation at eight years of age. Detailed morphological analyses of the explanted heart tissue showed intracytoplasmic inclusions, aggregation of BAG3 and desmin, disintegration of myofibers and Z-disk alterations. The presence of undegraded autophagosomes, seen by electron microscopy, as well as increased levels of p62, LC3-I and WIPI1, detected by immunohistochemistry and western blot analyses, indicated a dysregulation of autophagy. Parkin and PINK1, proteins involved in mitophagy, were slightly increased whereas mitochondrial OXPHOS activities were not altered. These findings indicate that altered autophagy plays a role in the pathogenesis and rapid progression of RCM in MFM caused by the BAG3-Pro209Leu mutation, which could have implications for future therapeutic strategies. Copyright © 2018 Elsevier Inc. All rights reserved.

  18. 40 CFR 60.4112 - Changing Hg designated representative and alternate Hg designated representative; changes in...

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Changing Hg designated representative and alternate Hg designated representative; changes in owners and operators. 60.4112 Section 60.4112... Generating Units Hg Designated Representative for Hg Budget Sources § 60.4112 Changing Hg designated...

  19. Production of leu high density fuels at Babcock and Wilcox

    International Nuclear Information System (INIS)

    Freim, J.B.

    1983-01-01

    A large number of fuel elements of all types are produced for both international and domestic customers by Nuclear Fuel Division of Babcock and Wilcox. A brief history of the division, included previous and present research reactor fuel element fabrication experience is discussed. The manufacturing facilities are briefly described. The fabrication of LEU fuels and economic analysis of the production are included. (A.J.)

  20. Intercomparison of rod-worth measurement techniques in a LEU-HTR assembly

    International Nuclear Information System (INIS)

    Williams, T.; Chawla, R.

    1994-01-01

    The measurement of absorber-rod worths in the radial reflector of a LEU-HTR pebble bed system is described. Particular emphasis is placed on the choice of complementary measurement techniques to ensure that sensitivities to systematic errors in the calculated parameters used in the analysis are minimised. (author) 3 figs., 3 tabs., 8 refs

  1. WAG (water-alternating-gas) process design: an update review

    Energy Technology Data Exchange (ETDEWEB)

    Zahoor, M.K. [University of Engineering and Technology, Lahore (Pakistan). Dept. of Petroleum and Gas Engineering], e-mail: mkzahoor@uet.edu.pk; Derahman, M.N.; Yunan, M.H. [Universiti Teknologi Malaysia, Johor (Malaysia). Dept. of Petroleum Engineering

    2011-04-15

    The design and implementation of water-alternating-gas (WAG) process in an improved and cost-effective way are still under process. Due to the complexities involved in implementing the process and the lack of information regarding fluid and reservoir properties, the water-alternating-gas process has not yet been as successful as initially expected. This situation can be overcome by better understanding the fluid distribution and flow behavior within the reservoir. The ultimate purpose can be achieved with improved knowledge on wettability and its influence on fluid distribution, capillary pressure, relative permeability, and other design parameters. This paper gives an insight on the WAG process design and the recently developed correlations which are helpful in incorporating the effects of wettability variations on fluid dynamics within the reservoir. (author)

  2. Subsurface barrier design alternatives for confinement and controlled advection flow

    International Nuclear Information System (INIS)

    Phillips, S.J.; Stewart, W.E.; Alexander, R.G.; Cantrell, K.J.; McLaughlin, T.J.

    1994-02-01

    Various technologies and designs are being considered to serve as subsurface barriers to confine or control contaminant migration from underground waste storage or disposal structures containing radioactive and hazardous wastes. Alternatives including direct-coupled flood and controlled advection designs are described as preconceptual examples. Prototype geotechnical equipment for testing and demonstration of these alternative designs tested at the Hanford Geotechnical Development and Test Facility and the Hanford Small-Tube Lysimeter Facility include mobile high-pressure injectors and pumps, mobile transport and pumping units, vibratory and impact pile drivers, and mobile batching systems. Preliminary laboratory testing of barrier materials and additive sequestering agents have been completed and are described

  3. RIP INPUT TABLES FROM WAPDEG FOR LA DESIGN SELECTION: ENHANCED DESIGN ALTERNATIVE V

    International Nuclear Information System (INIS)

    K. Mon

    1999-01-01

    The purpose of this calculation is to document (1) the Waste Package Degradation (WAPDEG) version 3.09 (CRWMS M and O 1998b, Software Routine Report for WAPDEG (Version 3.09)) simulations used to analyze degradation and failure of 2-cm thick titanium grade 7 corrosion resistant material (CRM) drip shields (that are placed over waste packages composed of a 2-cm thick Alloy 22 corrosion resistant material (CRM) as the outer barrier and an unspecified material to provide structural support as the inner barrier) as well as degradation and failure of the waste packages themselves, and (2) post-processing of these results into tables of drip shield/waste package degradation time histories suitable for use as input into the Integrated Probabilistic Simulator for Environmental Systems (RIP) version 5.19.01 (Golder Associates 1998) computer code. Performance credit of the inner barrier material is not taken in this calculation. This calculation supports Performance Assessment analysis of the License Application Design Selection (LADS) Enhanced Design Alternative V. Additional details concerning the Enhanced Design Alternative V are provided in a Design Input Request (CRWMS M and O 1999e, Design Input Request for LADS Phase II EDA Evaluations, Item 3)

  4. Neutron flux measurement in the central channel (XC-1) of TRIGA 14 MW LEU core

    International Nuclear Information System (INIS)

    BARBOS, D.; BUSUIOC, P.; ROTH, Cs.; PAUNOIU, C.

    2008-01-01

    The TRIGA 14 MW reactor, operated by Institute for Nuclear Research Pitesti, Romania, is a pool type reactor, and has a rectangular shape which holds fuel bundles and is surrounded with beryllium reflectors. Each fuel bundle is composed of 25 nuclear fuel rods. The TRIGA 14 MW reactor was commissioned 28 years ago with HEU fuel rods. The conversion was gradually achieved, starting in February 1992 and completed in March 2006. The full conversion of the 14 MW TRIGA Research Reactor was completed in May 2006 and each step of the conversion was achieved by removal of HEU fuel, replaced by LEU fuel, accompanied by a large set of theoretical evaluation and physical measurements intended to confirm the performances of gradual conversion. After the core full conversion, a program of measurements and comparisons with previous results of core physics and measurements is underway, allowing data acquisition for normal operation, demonstration of safety and economics of the converted core. Neutron flux spectrum measurements in the XC in the XC-1 water 1 water-filled channel were performed using multi multi-foil activation techniques. The neutron spectra and flux are obtained by unfolding from measured reaction rates using SAND II computer code. The integral neutron flux value for LEU core is greater of 13% than for the standard HEU core. Also thermal neutron flux value for converted LEU core is smaller by 0.38% than for the standard HEU core. These differences appear because the foil activation detectors have been irradiated using a pneumatic rabbit having a diameter of 32 mm, whereas foil irradiations in standard HEU core has been performed with a pneumatic rabbit having a diameter of 14 mm, and therefore the neutron spectra in LEU core is less thermalized and the weight of fast neutron is greater

  5. The development of in-process inventory walk-through examination system in the process at borrowing inspection between LEU fuel fabrication plants

    International Nuclear Information System (INIS)

    Nakamura, Norihito; Namekawa, Masaru; Owada, Isao; Kikuchi, Masaru; Kodani, Yoshiki; Nozawa, Yukio

    2005-01-01

    Since the Nuclear Material Control Center (NMCC) was designed the safeguards inspection organization by Ministry of Education, Culture, Sports, Science and Technology (MEXT) in December 1999, the NMCC has been performing safeguards inspection for the Nuclear Facilities in Japan. The NMCC has carried out the safeguards inspections to LEU Fuel Fabrication Plants (FFPs) and the NMCC has improved the method of safeguards inspection as it has changed over to the integrated safeguards from the year of 2005. Concerning the Borrowing inspection between LEU FFPs, which is the precondition to change over to the integrated safeguards, it is needed to estimate the entire inventory in the facility within the limited time. Therefore, the NMCC has developed the system called IWES (In-process inventory Walk-through Examination System) to examine the inventory in process smoothly, quickly and correctly at borrowing inspection, check the entire inventory quantity and evaluate them. This report describes how IWES aiming at effective/efficient confirmation of in-process inventory has been developed and how it is applied to the borrowing inspection activities. (author)

  6. A Conserved Leucine Occupies the Empty Substrate Site of LeuT in the Na+-free Return State

    DEFF Research Database (Denmark)

    Malinauskaite, Lina; Said, Saida; Sahin, Caglanur

    2016-01-01

    Bacterial members of the neurotransmitter:sodium symporter (NSS) family perform Na+-dependent amino-acid uptake and extrude H+ in return. Previous NSS structures represent intermediates of Na+/substrate binding or intracellular release, but not the inward-to-outward return transition. Here we...... report crystal structures of Aquifex aeolicus LeuT in an outward-oriented, Na+- and substrate-free state likely to be H+-occluded. We find a remarkable rotation of the conserved Leu25 into the empty substrate-binding pocket and rearrangements of the empty Na+ sites. Mutational studies of the equivalent...

  7. Thermal-hydraulic analysis of research reactor core with different LEU fuel types using RELAP5

    Energy Technology Data Exchange (ETDEWEB)

    El-Sahlamy, Neama M. [Nuclear and Radiological Regulatory Authority, Cairo (Egypt)

    2017-11-15

    In the current work, comparisons between the core performances when using different LEU fuels are done. The fuels tested are UA1{sub X}-A1, U{sub 3}O{sub 8}-Al, and U{sub 3}Si{sub 2}-Al fuels with 19.7 % enrichment. Calculations are done using RELAP5 code to evaluate the thermal-hydraulic performance of the IAEA benchmark 10 MW reactor. First, a reassessment of the slow reactivity insertion transient with UA1{sub X}-A1 LEU fuel to compare the results with those reported in the IAEA TECDOC [1]. Then, comparisons between the thermal-hydraulic core performances when using the three LEU fuels are done. The assessment is performed at initial power of 1.0 W. The reactor power is calculated using the RELAP5 point kinetic model. The reactivity feedback, from changes in water density and fuel temperature, is considered for all cases. From the results it is noticed that U{sub 3}Si{sub 2}-Al fuel gives the best fuel performance since it has the minimum value of peak fuel temperature and the minimum peak clad surface temperature, as operating parameters. Also, it gives the maximum value of the Critical Heat Flux Ratio and the lowest tendency to flow instability occurrence.

  8. Computational issues in alternating projection algorithms for fixed-order control design

    DEFF Research Database (Denmark)

    Beran, Eric Bengt; Grigoriadis, K.

    1997-01-01

    Alternating projection algorithms have been introduced recently to solve fixed-order controller design problems described by linear matrix inequalities and non-convex coupling rank constraints. In this work, an extensive numerical experimentation using proposed benchmark fixed-order control design...... examples is used to indicate the computational efficiency of the method. These results indicate that the proposed alternating projections are effective in obtaining low-order controllers for small and medium order problems...

  9. Neutronic analysis of the JMTR with LEU fuel and burnable poison

    Energy Technology Data Exchange (ETDEWEB)

    Nagaoka, Yoshiharu; Oyamada, Rokuro [Japan Atomic Energy Research Institute, Oarai-machi Ibaraki-ken (Japan); Matos, J E; Woodruff, W L [Argonne National Laboratory, Argonne, IL (United States)

    1985-07-01

    The results of neutronics calculations are presented for the JMTR equilibrium core with LEU silicide fuel, boron and cadmium burnable poisons in the sideplates, and a cycle length of 24 days instead of 11 days with the current HEU fuel. The data indicate that several options are feasible provided that silicide fuels with high uranium densities are successfully demonstrated and licensed (author)

  10. Neutronic analysis of the JMTR with LEU fuel and burnable poison

    International Nuclear Information System (INIS)

    Nagaoka, Yoshiharu; Oyamada, Rokuro; Matos, J.E.; Woodruff, W.L.

    1985-01-01

    The results of neutronics calculations are presented for the JMTR equilibrium core with LEU silicide fuel, boron and cadmium burnable poisons in the sideplates, and a cycle length of 24 days instead of 11 days with the current HEU fuel. The data indicate that several options are feasible provided that silicide fuels with high uranium densities are successfully demonstrated and licensed (author)

  11. Matter of transformation : designing an alternative tomorrow inspired by phenomenology

    NARCIS (Netherlands)

    Hummels, C.C.M.; Lévy, P.D.

    2013-01-01

    In this month’s cover story, Caroline Hummels and Pierre Lévy propose an alternative, value-based vision for design: Can we create alternative ways to engage with the world based on trusting our senses? Where intuition is as valuable as logic? Where commitment and engagement are valuable assets for

  12. The Leu72Met polymorphism of the ghrelin gene is significantly associated with binge eating disorder.

    Science.gov (United States)

    Monteleone, Palmiero; Tortorella, Alfonso; Castaldo, Eloisa; Di Filippo, Carmela; Maj, Mario

    2007-02-01

    The pathophysiological mechanisms underlying binge eating disorder are poorly understood. Evidence exists for the fact that abnormalities in peptides involved in the regulation of appetite, including ghrelin, may play a role in binge eating behavior. Genes involved in the ghrelin physiology may therefore contribute to the biological vulnerability to binge eating disorder. We examined whether two polymorphisms of the ghrelin gene, the G152A (Arg51Gln) and C214A (Leu72Met), were associated with binge eating disorder. Ninety obese or nonobese women with binge eating disorder and 119 normal weight women were genotyped at the ghrelin gene. Statistical analyses showed that the Leu72Met ghrelin gene variant was significantly more frequent in binge eating disorder patients (chi2=5.940; d.f.=1, P=0.01) and was associated with a moderate, but significant risk to develop binge eating disorder (odds ratio=2.725, 95% confidence interval: 1.168-6.350). Although these data should be regarded as preliminary because of the small sample size, they suggest that the Leu72Met ghrelin gene variant may contribute to the genetic susceptibility to binge eating disorder.

  13. Association between the ghrelin Leu72Met polymorphism and type 2 diabetes risk: a meta-analysis.

    Science.gov (United States)

    Liao, Ning; Xie, Zi-Kang; Huang, Jian; Xie, Zheng-Fu

    2013-04-01

    Data on the association between the ghrelin Leu72Met polymorphism and type 2 diabetes are conflicting. A meta-analysis was performed on this topic. We searched for case-control studies using electronic databases (Medline and PubMed) and reference lists of studies. Odds ratios (OR) and 95% confidence intervals (CI) assuming dominant, recessive and homozygote comparison genetic models were calculated. Six case-control studies involving a total of 3417 cases and 3081 controls were included in this meta-analysis. No association was found between the ghrelin Leu72Met polymorphism and type 2 diabetes risk in the overall population in dominant, recessive and homozygote comparison models. However, in subgroup analyses stratified by ethnicity, we found that the risk for type 2 diabetes was decreased in subjects with Met72+ genotypes in Caucasians (OR=0.79, 95% CI: 0.64-0.98, P(z)=0.030). The ghrelin Leu72Met polymorphism was protective against type 2 diabetes in Caucasians. Future studies performed in larger sample size are needed to allow a more definitive conclusion. Copyright © 2012 Elsevier B.V. All rights reserved.

  14. Alternative Design of Boat Fenders

    DEFF Research Database (Denmark)

    Banke, Lars

    1996-01-01

    for the installation of the fender and perhaps for removing it if new oil-risers are to be initialled. The use of crane boats is expensive and weather-dependent.With these effect sin mind, a study of the energy absorption in the fender system, i.e. the fender itself and the frame, is needed for further development......On offshore platforms the purpose of fenders is to protect the oil-risers against minor accidental collisions with supply vessels. Normally, the fender is designed by use of thin-walled tubes. However, the tube itself is not capable of resisting the impact load of the boat. Therefore, alternative...... designs are searched for the fender.Today, an often used improvement of the fender is to fill it with grout or concrete. However, this improvement is not optimal since the fillings increase the weight of the fender beyond the crane capacity of the platform. Thus, crane boats are needed...

  15. DDE-MURR Status Report of Conceptual Design Activities

    Energy Technology Data Exchange (ETDEWEB)

    N.E. Woolstenhulme; R.B. Nielson; M.H. Sprenger; G.K. Housley

    2012-09-01

    The Design Demonstration Experiment for the University of Missouri Research Reactor (DDE-MURR) is intended to facilitate Low Enriched Uranium (LEU) conversion of the MURR by demonstrating the performance and fabrication of the LEU fuel element design through an irradiation test in a 200mm channel at the Belgium Reactor 2. At the time this report was prepared the resources for furthering DDE design work were expected to be postponed. As such, the conceptual design effort to date is summarized herein in order to provide the status of key objectives, notable results, and provisions for future design work. These demonstrate that the DDE-MURR design effort is well on the path to producing a suitable irradiation experiment, but also exhibits several challenges for which timely resolution is recommend in order to facilitate success of the irradiation campaign and ultimate conversion of the MURR.

  16. DDE-MITR Status Report of Conceptual Design Activities

    Energy Technology Data Exchange (ETDEWEB)

    N.E. Woolstenhulme; R.B. Nielson; J.D. Wiest; J.W. Nielsen; G.A. Roth; S.D. Snow

    2012-09-01

    The Design Demonstration Experiment for the Massachusetts Institute of Technology Reactor (DDE-MITR) is intended to facilitate Low Enriched Uranium (LEU) conversion of the MITR by demonstrating the performance and fabrication of the LEU fuel element design through an irradiation test in the Advanced Test Reactor center flux trap. At the time this report was prepared the resources for furthering DDE design work were expected to be postponed. As such, the conceptual design effort to date is summarized herein in order to provide the status of key objectives, notable results, and provisions for future design work. These demonstrate that the DDE-MITR design effort is well on the path to producing a suitable irradiation experiment, but also exhibits several challenges for which timely resolution is recommend in order to facilitate success of the irradiation campaign and ultimate conversion of the MITR.

  17. DDE-NBSR Status Report of Conceptual Design Activities

    Energy Technology Data Exchange (ETDEWEB)

    N.E. Woolstenhulme; R.B. Nielson; B.P. Durtschi; C.R. Glass; G.A. Roth; D.T. Clark

    2012-09-01

    The Design Demonstration Experiment for the National Bureau of Standard Reactor (DDE-NBSR) is intended to facilitate Low Enriched Uranium (LEU) conversion of the NBSR by demonstrating the performance and fabrication of the LEU fuel element design through an irradiation test in the Advanced Test Reactor center flux trap. At the time this report was prepared the resources for furthering DDE design work were expected to be postponed. As such, the conceptual design effort to date is summarized herein in order to provide the status of key objectives, notable results, and provisions for future design work. These demonstrate that the DDE-NBSR design effort is well on the path to producing a suitable irradiation experiment, but also exhibits several challenges for which timely resolution is recommend in order to facilitate success of the irradiation campaign and ultimate conversion of the NBSR.

  18. Fuel conversion of JRR-4 from HEU to LEU

    International Nuclear Information System (INIS)

    Ichikawa, Hiroki; Nakajima, Teruo

    1997-01-01

    Japanese JRR-4 (Japan Research Reactor No.4) is a pool type, light water moderated and cooled, ETR type fuel reactor used for Shielding experiments, isotope production, neutron activation analyses, Si doping, reactor students training. It acieved first criticality on January 28, 1965 with maximum thermal power 3.5MW. The standard core consistes of 20 Fuel elements, 7 control rods 5 Irradiation holes, neutron source, graphite reflectors. Available thermal flux is 7x1013 n/cm2/s. Within the RERTR program plans are made for core conversion from HEU to LEU

  19. Further data of silicide fuel for the LEU conversion of JMTR

    International Nuclear Information System (INIS)

    Saito, M.; Futamura, Y.; Nakata, H.; Ando, H.; Sakurai, F.; Ooka, N.; Sakakura, A.; Ugajin, M.; Shirai, E.

    1990-01-01

    Silicide fuel data for the safety assessment of the JMTR LEU fuel conversion are being measured. The data include fission product release, thermal properties, behaviour under accident conditions, and metallurgical characteristics. The methods used in the experiments are discussed. Results of fission products release at high temperature are described. The release of iodine from the silicide fuel is considerably lower than for U-Al alloy fuel

  20. Neutronic analysis of the JMTR with LEU fuel and burnable poison

    International Nuclear Information System (INIS)

    Nagaoka, Yoshiharu; Oyamada, Rokuro; Matos, J.E.; Woodruff, W.L.

    1984-01-01

    The results of neutronics calculations are presented for the JMTR equilibrium core with LEU silicide fuel, boron and cadmium burnable poisons in the sideplates, and a cycle length of 24 days instead of 11 days with the current HEU fuel. The data indicate that several options are feasible provided that silicide fuels with high uranium densities are successfully demonstrated and licensed. 2 refs., 10 figs., 5 tabs

  1. Core instrumentation and pre-operational procedures for core conversion HEU to LEU

    International Nuclear Information System (INIS)

    1984-02-01

    This report is intended for the reactor operator, to be used as a manual or checklist for general guidance on pre-startup activities that need to be addressed in preparation for conversion to Low Enriched Fuel (LEU). All nuclear, thermodynamic and safety calculations should have been performed prior to this stage of the core conversion process. During these calculations and certainly before ordering the new LEU fuel elements the reactor operator needs to very carefully consider additional important factors concerning the new fuel: fuel reliability, reliability of fuel fabricator, reprocessing contract or fuel element storage and disposal, economics of the new fuel cycle. At this stage, too, a preoperational experimental programme has to be developed and presented to the regulatory authorities for approval. This experimental programme could lead to additional requirements on: in-core instrumentation, out-of-core instrumentation or additional experimental devices. Detailed instructions on specific tests and measurements are not provided in this report since much information on the subject is available in the open literature

  2. Antidepressant Specificity of Serotonin Transporter Suggested by Three LeuT-SSRI Structures

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Z.; Zhen, J; Karpowich, N; Law, C; Reith, M; Wang, D

    2009-01-01

    Sertraline and fluoxetine are selective serotonin re-uptake inhibitors (SSRIs) that are widely prescribed to treat depression. They exert their effects by inhibiting the presynaptic plasma membrane serotonin transporter (SERT). All SSRIs possess halogen atoms at specific positions, which are key determinants for the drugs' specificity for SERT. For the SERT protein, however, the structural basis of its specificity for SSRIs is poorly understood. Here we report the crystal structures of LeuT, a bacterial SERT homolog, in complex with sertraline, R-fluoxetine or S-fluoxetine. The SSRI halogens all bind to exactly the same pocket within LeuT. Mutation at this halogen-binding pocket (HBP) in SERT markedly reduces the transporter's affinity for SSRIs but not for tricyclic antidepressants. Conversely, when the only nonconserved HBP residue in both norepinephrine and dopamine transporters is mutated into that found in SERT, their affinities for all the three SSRIs increase uniformly. Thus, the specificity of SERT for SSRIs is dependent largely on interaction of the drug halogens with the protein's HBP.

  3. Microcystis aeruginos strain [D-Leu1] Mcyst-LR producer, from Buenos Aires province, Argentina

    Directory of Open Access Journals (Sweden)

    Lorena Rosso

    2014-04-01

    Full Text Available Objective: To show the toxicological and phylogenetic characterization of a native Microcystis aeruginosa (M. aeruginosa strain (named CAAT 2005-3 isolated from a water body of Buenos Aires province, Argentine. Methods: A M. aeruginosa strain was isolated from the drainage canal of the sewage treatment in the town of Pila, Buenos Aires province, Argentina and acclimated to laboratory conditions. The amplification of cpcBA-IGS Phcocyanin (PC, intergenic spacer and flanking regions was carried out in order to build a phylogenetic tree. An exactive/orbitrap mass spectrometer equipped with an electrospray ionization source (Thermo Fisher Scientific, Bremen, Germany was used for the LC/ESI-HRMS microcystins analysis. The number of cell/mL and [D-Leu1] Mcyst-LR production obtained as a function of time was modelled using the Gompertz equation. Results: The phylogenetic analysis showed that the sequence clustered with others M. aeruginosa sequences obtained from NCBI. The first Argentinian strain of M. aeruginosa (CAAT 2005-3 growing under culture conditions maintains the typical colonial architecture of M. aeruginosa with profuse mucilage. M. aeruginosa CAAT 2005-3 expresses a toxin variant, that was identified by LC-HRMS/Orbitrapas as [D-Leu1] microcystin-LR ([M+H]+=1 037.8 m/z. Conclusions: [D-Leu1] microcystin-LR has been also detected in M. aeruginosa samples from Canada, Brazil and Argentina. This work provides the basis for technological development and production of analytical standards of toxins present in our region.

  4. Association of the Leu72Met polymorphism of the ghrelin gene with the risk of Type 2 diabetes in subjects with impaired glucose tolerance in the Finnish Diabetes Prevention Study.

    Science.gov (United States)

    Mager, U; Lindi, V; Lindström, J; Eriksson, J G; Valle, T T; Hämäläinen, H; Ilanne-Parikka, P; Keinänen-Kiukaanniemi, S; Tuomilehto, J; Laakso, M; Pulkkinen, L; Uusitupa, M

    2006-06-01

    Ghrelin is a gut-brain regulatory peptide stimulating appetite and controlling energy balance. In previous studies, the Leu72Met polymorphism of the ghrelin gene has been associated with obesity and impaired insulin secretion. We investigated whether the Leu72Met polymorphism is associated with the incidence of Type 2 diabetes in subjects with impaired glucose tolerance (IGT) participating in the Finnish Diabetes Prevention Study (DPS). DPS was a longitudinal intervention study carried out in five participating centres in Finland. A total of 522 subjects with IGT were randomized into either an intervention or a control group and DNA was available from 507 subjects. The Leu72Met polymorphism was screened by the restriction fragment length polymorphism method. There were no differences in clinical and anthropometric characteristics among the genotypes at baseline. IGT subjects with the Met72 allele were at higher risk of developing Type 2 diabetes than subjects with the Leu72Leu genotype (P = 0.046). Our data also demonstrated that IGT subjects with the common Leu72Leu genotype developed Type 2 diabetes less frequently under intervention circumstances than subjects with the Met72 allele (OR = 0.28, 95% CI 0.10-0.79; P = 0.016). Subjects with the Leu72Leu genotype had a lower risk for the development of Type 2 diabetes. This was observed particularly in the study subjects who underwent an intensive diet and exercise intervention. Defective first-phase insulin secretion related to the Met72 allele might be one factor contributing to the conversion to Type 2 diabetes.

  5. Foreign research reactor spent nuclear fuel inventories containing HEU and LEU of US-origin

    International Nuclear Information System (INIS)

    Matos, J.E.

    1995-01-01

    This paper provides estimates of the quantities and types of foreign research reactor spent nuclear fuel containing HEU and LEU of US-origin that are anticipated during the period beginning in January 1996 and extending for 10-15 years

  6. HEU and Leu FueL Shielding Comparative Study Applied for Spent Fuel Transport

    International Nuclear Information System (INIS)

    Margeanu, C.A.; Margeanu, S.; Barbos, D.

    2009-01-01

    INR Pitesti owns and operates a TRIGA dual-core Research Reactor for material testing, power reactor fuel and nuclear safety studies. The dual core concept involves the operation of a 14 MW TRIGA steady-state, high flux research and material testing reactor at one end of a large pool, and the independent operation of an annular-core pulsing reactor (TRIGA-ACPR) at the other end of the pool. The steady-state reactor is mostly used for long term testing of power reactor fuel components (pellets, pins, subassemblies and fuel assemblies) followed by post-irradiation examination. Following the general trend to replace the He fuel type (High Enriched Uranium) by Leu fuel type (Low Enriched Uranium), in the light of international agreements between IAEA and the states using He fuel in their nuclear reactors, Inr Past's have been accomplished the TRIGA research reactor core full conversion on May 2006. The He fuel repatriation in US in the frame of Foreign Research Reactor Spent Nuclear Fuel Return Programme effectively started in 1999, the final stage being achieved in summer of 2008. Taking into account for the possible impact on the human and environment, in all activities associated to nuclear fuel cycle, the spent fuel or radioactive waste characteristics must be well known. Shielding calculations basic tasks consist in radiation doses calculation, in order to prevent any risks both for personnel protection and impact on the environment during the spent fuel manipulation, transport and storage. The paper is a comparative study of Leu and He fuel utilization effects for the shielding analysis during spent fuel transport. A comparison against the measured data for He spent fuel, available from the last stage of the spent fuel repatriation, is presented. All the geometrical and material data related on the spent fuel shipping cask were considered according to the Nac-Lt Cask approved model. The shielding analysis estimates radiation doses to shipping cask wall surface

  7. Gas generation during waste treatment of acidic solutions from the dissolution of irradiated LEU targets for 99Mo production

    Energy Technology Data Exchange (ETDEWEB)

    Bakel, Allen J. [Argonne National Lab. (ANL), Argonne, IL (United States); Conner, Cliff [Argonne National Lab. (ANL), Argonne, IL (United States); Quigley, Kevin [Argonne National Lab. (ANL), Argonne, IL (United States); Vandegrift, George F. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2017-01-01

    The goal of the Reduced Enrichment for Research and Test Reactors Program is to limit the use of high-enriched uranium (HEU) in research and test reactors by substituting low-enriched uranium (LEU) wherever possible. The work reported here documents our work to develop the calcining technologies and processes that will be needed for 99Mo production using LEU foil targets and the Modified Cintichem Process. The primary concern with the conversion to LEU from HEU targets is that it would result in a five- to six-fold increase in the total uranium. This increase results in more liquid waste from the process. We have been working to minimize the increase in liquid waste and to minimize the impact of any change in liquid waste. Direct calcination of uranium-rich nitric acid solutions generates NO2 gas and UO3 solid. We have proposed two processes for treating the liquid waste from a Modified Cintichem Process with a LEU foil. One is an optimized direct calcination process that is similar to the process currently in use. The other is a uranyl oxalate precipitation process. The specific goal of the work reported here was to characterize and compare the chemical reactions that occur during these two processes. In particular, the amounts and compositions of the gaseous and solid products were of interest. A series of experiments was carried out to show the effects of temperature and the redox potential of the reaction atmosphere. The primary products of the direct calcination process were mixtures of U3O8 and UO3 solids and NO2 gas. The primary products of the oxalate precipitation process were mixtures of U3O8 and UO2 solid and CO2 gas. Higher temperature and a reducing atmosphere tended to favor quadrivalent over hexavalent uranium in the solid product. These data will help producers to decide between the two processes. In addition, the data can be used

  8. Review on JMTR safety design for LEU core conversion

    International Nuclear Information System (INIS)

    Komori, Yoshihiro; Yokokawa, Makoto; Saruta, Toru; Inada, Seiji; Sakurai, Fumio; Yamamoto, Katsumune; Oyamada, Rokuro; Saito, Minoru

    1993-12-01

    Safety of the JMTR was fully reviewed for the core conversion to low enriched uranium fuel. Fundamental policies for the JMTR safety design were reconsidered based on the examination guide for safety design of test and research reactors, and safety of the JMTR was confirmed. This report describes the safety design of the JMTR from the viewpoint of major functions for reactor safety. (author)

  9. The study, design and simulation of a free piston Stirling engine linear alternatorThe study, design and simulation of a free piston Stirling engine linear alternator

    Directory of Open Access Journals (Sweden)

    Teodora Susana Oros

    2014-12-01

    Full Text Available This paper presents a study, design and simulation of a Free Piston Stirling Engine Linear Alternator. There are presented the main steps of the magnetic and electric calculations for a permanent magnet linear alternator of fixed coil and moving magnets type. Finally, a detailed thermal, mechanical and electrical model for a Stirling engine linear alternator have been made in SIMULINK simulation program. The linear alternator simulation model uses a controllable DC voltage which simulates the linear alternator combined with a rectifier, a variable load and a DC-DC converter, which compensates for the variable nature of Stirling engine operation, and ensures a constant voltage output regardless of the load.

  10. N-AC-l-Leu-PEI-mediated miR-34a delivery improves osteogenic differentiation under orthodontic force.

    Science.gov (United States)

    Yu, Wenwen; Zheng, Yi; Yang, Zhujun; Fei, Hongbo; Wang, Yang; Hou, Xu; Sun, Xinhua; Shen, Yuqin

    2017-12-15

    Rare therapeutic genes or agents are reported to control orthodontic bone remodeling. MicroRNAs have recently been associated with bone metabolism. Here, we report the in vitro and in vivo effects of miR-34a on osteogenic differentiation under orthodontic force using an N -acetyl-L-leucine-modified polyethylenimine ( N -Ac-l-Leu-PEI) carrier. N -Ac-l-Leu-PEI exhibited low cytotoxicity and high miR-34a transfection efficiency in rat bone mineral stem cells and local alveolar bone tissue. After transfection, miR-34a enhanced the osteogenic differentiation of Runx2 and ColI , Runx2 and ColI protein levels, and early osteogenesis function under orthodontic strain in vitro . MiR-34a also enhanced alveolar bone remodeling under orthodontic force in vivo , as evidenced by elevated gene and protein expression, upregulated indices of alveolar bone anabolism, and diminished tooth movement. We determined that the mechanism miR-34a in osteogenesis under orthodontic force may be associated with GSK-3β. These results suggested that miR-34a delivered by N -Ac-l-Leu-PEI could be a potential therapeutic target for orthodontic treatment.

  11. Performance of Estimation of distribution algorithm for initial core loading optimization of AHWR-LEU

    International Nuclear Information System (INIS)

    Thakur, Amit; Singh, Baltej; Gupta, Anurag; Duggal, Vibhuti; Bhatt, Kislay; Krishnani, P.D.

    2016-01-01

    Highlights: • EDA has been applied to optimize initial core of AHWR-LEU. • Suitable value of weighing factor ‘α’ and population size in EDA was estimated. • The effect of varying initial distribution function on optimized solution was studied. • For comparison, Genetic algorithm was also applied. - Abstract: Population based evolutionary algorithms now form an integral part of fuel management in nuclear reactors and are frequently being used for fuel loading pattern optimization (LPO) problems. In this paper we have applied Estimation of distribution algorithm (EDA) to optimize initial core loading pattern (LP) of AHWR-LEU. In EDA, new solutions are generated by sampling the probability distribution model estimated from the selected best candidate solutions. The weighing factor ‘α’ decides the fraction of current best solution for updating the probability distribution function after each generation. A wider use of EDA warrants a comprehensive study on parameters like population size, weighing factor ‘α’ and initial probability distribution function. In the present study, we have done an extensive analysis on these parameters (population size, weighing factor ‘α’ and initial probability distribution function) in EDA. It is observed that choosing a very small value of ‘α’ may limit the search of optimized solutions in the near vicinity of initial probability distribution function and better loading patterns which are away from initial distribution function may not be considered with due weightage. It is also observed that increasing the population size improves the optimized loading pattern, however the algorithm still fails if the initial distribution function is not close to the expected optimized solution. We have tried to find out the suitable values for ‘α’ and population size to be considered for AHWR-LEU initial core loading pattern optimization problem. For sake of comparison and completeness, we have also addressed the

  12. Integrin beta3 Leu33Pro polymorphism and risk of hip fracture: 25 years follow-up of 9233 adults from the general population

    DEFF Research Database (Denmark)

    Tofteng, Charlotte L; Bach-Mortensen, Pernille; Bojesen, Stig E

    2007-01-01

    for the integrin beta3 Leu33Pro polymorphism have a two-fold risk of hip fracture, mainly confined to postmenopausal women. Integrin beta3 Leu33Pro homozygosity could prove a useful marker for risk of future hip fracture and may contribute to pharmacogenetic variation in effects of integrin alphavbeta3 antagonists....

  13. Developing Techniques for Small Scale Indigenous Molybdenum-99 Production Using LEU Fission at Tajoura Research Center-Libya [Country report: Libya

    International Nuclear Information System (INIS)

    Alwaer, Sami M.

    2015-01-01

    The object of this work was to assist the IAEA by providing the Libyan country report about the Coordination Research Project (CRP), on the subject of “Developing techniques for small scale indigenous Mo-99 production using LEU-foil” which took place over five years and four RCMs. A CRP on this subject was approved in early 2005. The objectives of this CRP are to: transfer know-how in the area of 99 Mo production using LEU targets based on reference technologies from leading laboratories in the field to the participating laboratories in the CRP; develop national work plans based on various stages of technical development and objectives in this field; establish the procedures and protocols to be employed, including quality control and assurance procedures; establish the coordinated activities and programme for preparation, irradiation, and processing of LEU targets [a]; and to compare results obtained in the implementation of the technique in order to provide follow up advice and assistance. Technetium-99m ( 99m Tc), the daughter product of molybdenum-99 ( 99 Mo), is the most commonly utilized medical radioisotope in the world, used for approximately 20-25 million medical diagnostic procedures annually, comprising some 80% of all diagnostic nuclear medicine procedures. National and international efforts are underway to shift the production of medical isotopes from highly enriched uranium (HEU) to low enriched uranium (LEU) targets. A small but growing amount of the current global 99 Mo production is derived from the irradiation of LEU targets. The IAEA became aware of the interest of a number of developing Member States that are seeking to become small scale, indigenous producers of 99 Mo to meet local nuclear medicine requirements. The IAEA initiated Coordinated Research Project (CRP) T.1.20.18 “Developing techniques for small-scale indigenous production of Mo-99 using LEU or neutron activation” in order to assist countries in this field. The more

  14. Role of Annular Lipids in the Functional Properties of Leucine Transporter LeuT Proteomicelles.

    Science.gov (United States)

    LeVine, Michael V; Khelashvili, George; Shi, Lei; Quick, Matthias; Javitch, Jonathan A; Weinstein, Harel

    2016-02-16

    Recent work has shown that the choice of the type and concentration of detergent used for the solubilization of membrane proteins can strongly influence the results of functional experiments. In particular, the amino acid transporter LeuT can bind two substrate molecules in low concentrations of n-dodecyl β-d-maltopyranoside (DDM), whereas high concentrations reduce the molar binding stoichiometry to 1:1. Subsequent molecular dynamics (MD) simulations of LeuT in DDM proteomicelles revealed that DDM can penetrate to the extracellular vestibule and make stable contacts in the functionally important secondary substrate binding site (S2), suggesting a potential competitive mechanism for the reduction in binding stoichiometry. Because annular lipids can be retained during solubilization, we performed MD simulations of LeuT proteomicelles at various stages of the solubilization process. We find that at low DDM concentrations, lipids are retained around the protein and penetration of detergent into the S2 site does not occur, whereas at high concentrations, lipids are displaced and the probability of DDM binding in the S2 site is increased. This behavior is dependent on the type of detergent, however, as we find in the simulations that the detergent lauryl maltose-neopentyl glycol, which is approximately twice the size of DDM and structurally more closely resembles lipids, does not penetrate the protein even at very high concentrations. We present functional studies that confirm the computational findings, emphasizing the need for careful consideration of experimental conditions, and for cautious interpretation of data in gathering mechanistic information about membrane proteins.

  15. Demonstration of risk-based decision analysis in remedial alternative selection and design

    International Nuclear Information System (INIS)

    Evans, E.K.; Duffield, G.M.; Massmann, J.W.; Freeze, R.A.; Stephenson, D.E.

    1993-01-01

    This study demonstrates the use of risk-based decision analysis (Massmann and Freeze 1987a, 1987b) in the selection and design of an engineering alternative for groundwater remediation at a waste site at the Savannah River Site, a US Department of Energy facility in South Carolina. The investigation focuses on the remediation and closure of the H-Area Seepage Basins, an inactive disposal site that formerly received effluent water from a nearby production facility. A previous study by Duffield et al. (1992), which used risk-based decision analysis to screen a number of ground-water remediation alternatives under consideration for this site, indicated that the most attractive remedial option is ground-water extraction by wells coupled with surface water discharge of treated effluent. The aim of the present study is to demonstrate the iterative use of risk-based decision analysis throughout the design of a particular remedial alternative. In this study, we consider the interaction between two episodes of aquifer testing over a 6-year period and the refinement of a remedial extraction well system design. Using a three-dimensional ground-water flow model, this study employs (1) geostatistics and Monte Carlo techniques to simulate hydraulic conductivity as a stochastic process and (2) Bayesian updating and conditional simulation to investigate multiple phases of aquifer testing. In our evaluation of a remedial alternative, we compute probabilistic costs associated with the failure of an alternative to completely capture a simulated contaminant plume. The results of this study demonstrate the utility of risk-based decision analysis as a tool for improving the design of a remedial alternative through the course of phased data collection at a remedial site

  16. Core management and reactor physics aspects of the conversion of the NRU reactor to LEU

    International Nuclear Information System (INIS)

    Atfield, M.D.

    1985-01-01

    Results of work done to assess the effects of converting the NRU reactor to LEU are presented. The effects are small, and the operational rules and safety analysis, appropriate to the HEU core, will still apply. (author)

  17. Neutronic calculations of PARR-1 cores using LEU silicide fuel

    International Nuclear Information System (INIS)

    Arshad, M.; Bakhtyar, S.; Hayat, T.; Salahuddin, A.

    1991-08-01

    Detailed neutronic calculations have been carried out for different PARR-1 cores utilizing low enriched uranium (LEU) silicide fuel and operating at an upgraded power of 9 MW. The calculations include the search for critical loadings in open and stall ends of the pool, neutronic analysis of the first full equilibrium core and calculations cores. The burnup study of inventory have also been carried out. Further, the reactivity coefficients of the first full power operation core are evaluated for use in the accident analysis. 14 figs. (author)

  18. A comparative and predictive study of the annual fuel cycle costs for HEU and LEU fuels in the High Flux Reactor, Petten, 1985-1993

    Energy Technology Data Exchange (ETDEWEB)

    Moss, R L; May, P

    1985-07-01

    The internationally agreed constraint on availability of supply of HEU fuels to Research and Test Reactors has necessitated that a cost analysis be carried out to determine the financial effect of converting the core of the HFR from HEU to LEU fuels. A computer program, written at Petten and based on information extracted from studies in Europe and the USA, identifies the major cost variables to be manufacturing, uranium, reprocessing and transport costs. Comparison between HEU and LEU cores have been carried out and includes the effects of inflation and exchange rate fluctuations. Conversion of the HFR core to LEU fuels is shown to be financially disadvantageous. (author)

  19. A comparative and predictive study of the annual fuel cycle costs for HEU and LEU fuels in the High Flux Reactor, Petten, 1985-1993

    International Nuclear Information System (INIS)

    Moss, R.L.; May, P.

    1985-01-01

    The internationally agreed constraint on availability of supply of HEU fuels to Research and Test Reactors has necessitated that a cost analysis be carried out to determine the financial effect of converting the core of the HFR from HEU to LEU fuels. A computer program, written at Petten and based on information extracted from studies in Europe and the USA, identifies the major cost variables to be manufacturing, uranium, reprocessing and transport costs. Comparison between HEU and LEU cores have been carried out and includes the effects of inflation and exchange rate fluctuations. Conversion of the HFR core to LEU fuels is shown to be financially disadvantageous. (author)

  20. Environmental comparison of a railway bridge with alternative designs

    DEFF Research Database (Denmark)

    Du, Guangli; Karoumi, Raid

    2012-01-01

    Railway bridges are complex structures that remain for a long life span and consume large amount of material and energy throughout the life span. All of those lead to considerable resource depletion and environmental burdens. Life Cycle Assessment (LCA) has proved to be a comprehensive tool...... for quantifying and assessing the environmental impacts of the products through its whole life cycle. This paper presents a comparative case study between two alternative designs of Banafjäl Bridge: ballast track design and fixed slab track design. The methodology of LCA is utilized as a supporting tool...

  1. Techno-economic study on conversion of SAFARI-1 to LEU silicide fuel

    International Nuclear Information System (INIS)

    Ball, G.; Malherbe, F.J.

    2004-01-01

    This paper marks the conclusion of the techno-economic study into the conversion of SAFARI-1 reactor in South Africa to LEU silicide fuel. Several different fuel types were studied and their characteristics compared to the current HEU fuel. The technical feasibility of operating SAFARI-1 with the different fuels as well as the overall economic impact of the fuels is discussed and conclusions drawn.(author)

  2. Determination of Dancoff correction thermal utilization and thermal disadvantage factors of HEU and LEU cores of an MNSR

    International Nuclear Information System (INIS)

    Ofori, Y. T.

    2013-07-01

    Ghana Research Reactor-1 (GHARR-1), an MNSR (Miniature Neutron Source Reactor) is to be converted from HEU (Highly Enriched Uranium) to LEU (Low Enriched Uranium) fuel, along with all current MNSRs in various other countries. The purpose of the conversion is to minimize the use of HEU for non-proliferation of high-grade nuclear fuel. In this research work, a comparative study has been performed for the determination of the Dancoff, thermal utilization and thermal disadvantage factors of highly enriched uranium (HEU) and potential low enriched uranium (LEU) cores of GHARR-1. A one group transport theory and collision probability based methodologies was used to develop mathematical formulations for thermal utilization factor and thermal disadvantage factor assuming isotropic scattering. This methodology was implemented in a FORTRAN 95 based computer program THERMCALC, which uses Bessell and BesselK as subroutines developed to calculate the modified Bessel functions I n and K n respectively using the polynomial approximation method. Furthermore, a Dancoff correction factor of 0.1519 thermal utilization factor of 0.9767 and a thermal disadvantage factor of 1.894 were obtained for the 90.2% highly enriched Uranium core of GHARR-1. The results compare favorably with literature. Thus THERMCALC can be used as a reliable tool for the calculation of Dancoff, thermal utilization and disadvantage factors of MNSR cores. Other potential LEU cores; UO 2 (with different fuel meat densities and enrichments) and U 3 Si 2 have also been analysed. UO 2 with 12.6% of Uranium-235 was chosen as the most potential LEU core for the GHARR-1. (au)

  3. Comparison of HEU and LEU neutron spectra in irradiation facilities at the Oregon State TRIGA® Reactor

    International Nuclear Information System (INIS)

    Schickler, R.A.; Marcum, W.R.; Reese, S.R.

    2013-01-01

    Highlights: • The Oregon State TRIGA ® Reactor neutron spectra is characterized herein. • Neutron spectra between highly enriched uranium and low enriched uranium cores are compared. • Discussion is given as to differences between HEU and LEU core spectra results and impact on experiments. -- Abstract: In 2008, the Oregon State TRIGA ® Reactor (OSTR) was converted from highly enriched uranium (HEU) fuel lifetime improvement plan (FLIP) fuel to low-enriched uranium (LEU) fuel. This effort was driven and supported by the Department of Energy's (DoE's) Reduced Enrichment for Research and Test Reactors (RERTR) program. The basis behind the RERTR program's ongoing conversion effort is to reduce the nuclear proliferation risk of civilian research and test reactors. The original intent of the HEU FLIP fuel was to provide fuel to research reactors that could be utilized for many years before a necessary refueling cycle. As a research reactor, the OSTR provides irradiation facilities for a variety of applications, such as activation analysis, fission-track dating, commercial isotope production, neutron radiography, prompt gamma characterization, and many others. In order to accurately perform these research functions, several studies had been conducted on the HEU FLIP fuel core to characterize the neutron spectra in various experimental facilities of the OSTR (Tiyapun, 1997; Ashbaker, 2005). As useful as these analyses were, they are no longer valid due to the change in fuel composition and the resulting alteration of core performance characteristics. Additionally, the core configuration (fuel reconfiguration) was altered between the HEU and LEU cores. This study characterizes the neutron spectra in various experimental facilities within and around the current LEU core. It also compares the spectra to that which was yielded in the HEU core through use of Monte Carlo n-Particle 5 (MCNP5) and experimental adjustment via a least-squares technique. The quantification of

  4. An Alternative View of Some FIA Sample Design and Analysis Issues

    Science.gov (United States)

    Paul C. Van Deusen

    2005-01-01

    Sample design and analysis decisions are the result of compromises and inputs from many sources. The end result would likely change if different individuals or groups were involved in the planning process. Discussed here are some alternatives to the procedures that are currently being used for the annual inventory. The purpose is to indicate that alternatives exist and...

  5. Infantile presentation of the mtDNA A3243G tRNA(Leu (UUR)) mutation.

    NARCIS (Netherlands)

    Okhuijsen-Kroes, E.J.; Trijbels, J.M.F.; Sengers, R.C.A.; Mariman, E.C.M.; Heuvel, L.P.W.J. van den; Wendel, U.A.H.; Koch, G.; Smeitink, J.A.M.

    2001-01-01

    Mitochondrial DNA (mtDNA) disorders are clinically very heterogeneous, ranging from single organ involvement to severe multisystem disease. One of the most frequently observed mtDNA mutations is the A-to-G transition at position 3243 of the tRNA(Leu (UUR)) gene. This mutation is often related to

  6. Providing training enhances the biomechanical improvements of an alternative computer mouse design

    NARCIS (Netherlands)

    Houwink, A.; Oude Hengel, K.M.; Odell, D.; Dennerlein, J.T.

    2009-01-01

    To determine if an alternative mouse promotes more neutral postures and decreases forearm muscle activity and if training enhances these biomechanical benefits is the purpose of the study. Computer mouse use is a risk factor for developing musculoskeletal disorders; alternative mouse designs can

  7. Immunoregulatory T cells in man. Histamine-induced suppressor T cells are derived from a Leu 2+ (T8+) subpopulation distinct from that which gives rise to cytotoxic T cells

    International Nuclear Information System (INIS)

    Sansoni, P.; Silverman, E.D.; Khan, M.M.; Melmon, K.L.; Engleman, E.G.

    1985-01-01

    One mechanism of histamine-mediated inhibition of the immune response in man is to activate T suppressor cells that bear the Leu 2 (OKT8) marker. The current study was undertaken to characterize the histamine-induced suppressor cell using a monoclonal antibody (9.3) shown previously to distinguish cytotoxic T cells from antigen-specific suppressor T cells. Leu 2+ cells isolated from peripheral blood were further separated with antibody 9.3 into Leu 2+, 9.3+, and Leu 2+, 9.3- subsets and each subset was incubated with different concentrations of histamine before determining their ability to suppress immune responses in vitro. The results indicate that the Leu 2+, 9.3- subpopulation includes all histamine-induced suppressor cells, that 10(-4) M histamine is the optimal concentration for suppressor cell induction, and that exposure of Leu 2+, 9.3- cells to histamine for 30 s is sufficient to initiate the induction process. After treatment with histamine these cells inhibit both phytohemagglutinin-induced T cell proliferation and pokeweed mitogen-induced B cell differentiation. The suppression of phytohemagglutinin-induced proliferation was resistant to x-irradiation with 1,200 rad, either before or after histamine exposure, suggesting that Leu 2+, 9.3- cells need not proliferate to become suppressor cells or exert suppression. Moreover, suppression by these cells was not due to altered kinetics of the response. Finally, a histamine type 2 receptor antagonist (cimetidine) but not a type 1 receptor antagonist (mepyramine) blocked the induction of suppressor cells. On the basis of these results and our previous studies of antigen specific suppressor cells, we conclude that Leu 2+ suppressor cells in man are derived from a precursor pool that is phenotypically distinct from cells that can differentiate into cytotoxic T cells

  8. Qualification status of LEU [low enriched uranium] fuels

    International Nuclear Information System (INIS)

    Snelgrove, J.L.

    1987-01-01

    Sufficient data has been obtained from tests of high-density, low-enriched fuels for research and test reactors to declare them qualified for use. These fuels include UZrH x (TRIGA fuel) and UO 2 (SPERT fuel) for rod-type reactors and UAl x , U 3 O 8 , U 3 Si 2 , and U 3 Si dispersed in aluminium for plate-type reactors. Except for U 3 Si, the allowable fission density for LEU applications is limited only by the available 235 U. Several reactors are now using these fuels, and additional conversions are in progress. The basic performance characteristics and limits, if any, of the qualified low-enriched (and medium-enriched) fuels are discussed. Continuing and planned work to qualify additional fuels is also discussed. (Author)

  9. Comparison of MCNP calculations against measurements in moderator temperature experiments with CANFLEX-LEU in ZED-2

    International Nuclear Information System (INIS)

    Watts, D.G.; Adams, F.P.; Zeller, M.B.; Bromley, B.P.

    2008-01-01

    This paper summarizes sample calculations of MCNP5 compared against measurements of moderator temperature coefficient experiments in the ZED-2 critical facility with CANFLEX-LEU fuel. MCNP5 is tested for key parameters associated with various reactor physics phenomena of interest for CANDU/ACR-1000) reactors, including reactivity changes with coolant density, moderator density, and moderator temperature, and also normalized flux distributions. The experimental data for these comparisons were obtained from critical experiments in AECL's ZED-2 critical facility using CANFLEX-LEU fuel in a 24-cm square lattice pitch. These comparisons establish biases/uncertainties in the calculation of k-eff, coolant void reactivity, and moderator temperature coefficient of reactivity. Results show very little bias in the moderator temperature coefficient of reactivity, and very good agreement in the calculation of normalized flux distributions. (author)

  10. Neutronic analysis for conversion of the Ghana Research Reactor-1 facility using Monte Carlo methods and UO{sub 2} LEU fuel

    Energy Technology Data Exchange (ETDEWEB)

    Anim-Sampong, S.; Akaho, E.H.K.; Maakuu, B.T.; Gbadago, J.K. [Ghana Research Reactor-1 Centre, Dept. of Nuclear Engineering and Materials Science, National Nuclear Research Institute, Ghana Atomic Energy Commission, Legon, Accra (Ghana); Andam, A. [Kwame Nkrumah Univ. of Science and Technology, Dept. of Physics (Ghana); Liaw, J.J.R.; Matos, J.E. [Argonne National Lab., RERTR Programme, Div. of Nuclear Engineering (United States)

    2007-07-01

    Monte Carlo particle transport methods and software (MCNP) have been applied to the modelling, simulation and neutronic analysis for the conversion of the HEU-fuelled (high enrichment uranium) core of the Ghana Research Reactor-1 (GHARR-1) facility. The results show that the MCNP model of the GHARR-1 facility, which is a commercial version of the Miniature Neutron Source Reactor (MNSR) is good as the simulated neutronic and other reactor physics parameters agree with very well with experimental and zero power results. Three UO{sub 2} LEU (low enrichment uranium) fuels with different enrichments (12.6% and 19.75%), core configurations, core loadings were utilized in the conversion studies. The nuclear criticality and kinetic parameters obtained from the Monte Carlo simulation and neutronic analysis using three UO{sub 2} LEU fuels are in close agreement with results obtained for the reference 90.2% U-Al HEU core. The neutron flux variation in the core, fission chamber and irradiation channels for the LEU UO{sub 2} fuels show the same trend as the HEU core as presented in the paper. The Monte Carlo model confirms a reduction (8% max) in the peak neutron fluxes simulated in the irradiation channels which are utilized for experimental and commercial activities. However, the reductions or 'losses' in the flux levels neither affects the criticality safety, reactor operations and safety nor utilization of the reactor. Employing careful core loading optimization techniques and fuel loadings and enrichment, it is possible to eliminate the apparent reductions or 'losses' in the neutron fluxes as suggested in this paper. Concerning neutronics, it can be concluded that all the 3 LEU fuels qualify as LEU candidates for core conversion of the GHARR-1 facility.

  11. Alternate design concept for the SSC dipole magnet cryogenic support post

    International Nuclear Information System (INIS)

    Lipski, A.; Nicol, T.H.; Richardson, R.

    1991-03-01

    New materials and developments in the field of advanced composites have created the opportunity to take a fresh look into the design of the cryogenic supports for SSC collider dipole cryostats. Although the present reentrant post design meets the structural and thermal requirements, its assembly requires precision and proficiency. The objective of the proposed alternate concept is to reduce the overall cost of the support post by means of simplifying and optimizing its component design and assembly process. The present shrink fitted tube assembly may potentially be replaced by injection molded parts. New resin systems with lower thermal conductivity and high strength properties enable the utilization of automated production techniques such as injection molding and filament winding. This paper will provide analysis and design information for the alternate support post concept and compare its test performance and cost to the present support post. 3 refs., 12 figs., 4 tabs

  12. Cell and stack design alternatives. Final report, August 1, 1978-December 31, 1979

    Energy Technology Data Exchange (ETDEWEB)

    Hoover, Jr., D. Q.; King, Robert B.

    1980-02-01

    The work described comprised the first phase of a planned six phase program to develop commercially viable phosphoric acid fuel cell (PAFC) driven on-site integrated energy systems (OS/IES). The Phase I effort was organized as three major technical tasks; (1) study of system design alternatives; (2) fuel cell design alternatives; and (3) methane conditioner study. It was decided that comprehensive modeling of one application would most effectively utilize the resources available for the study of systems design alternatives. A 48 unit apartment complex located in Albany, New York and built to HUD minimum standards was selected as being typical of the applications that will be served by the systems. The time varying space conditioning (HVAC) and electrical requirements including the effects of varying weather conditions, living habits and occupancy patterns were modeled. These requirements formed the basis for comparing the performance and cost of the alternative configurations with each other and with a conventional system. Five basic alternative OS/IES configurations plus four variations were selected from a preliminary list of 13 basic configurations for detailed performance nd cost evaluations. Study procedures and results are presented in detail. (WHK)

  13. Arizona Public Service - Alternative Fuel (Hydrogen) Pilot Plant Design Report

    Energy Technology Data Exchange (ETDEWEB)

    James E. Francfort

    2003-12-01

    Hydrogen has promise to be the fuel of the future. Its use as a chemical reagent and as a rocket propellant has grown to over eight million metric tons per year in the United States. Although use of hydrogen is abundant, it has not been used extensively as a transportation fuel. To assess the viability of hydrogen as a transportation fuel and the viability of producing hydrogen using off-peak electric energy, Pinnacle West Capital Corporation (PNW) and its electric utility subsidiary, Arizona Public Service (APS) designed, constructed, and operates a hydrogen and compressed natural gas fueling station—the APS Alternative Fuel Pilot Plant. This report summarizes the design of the APS Alternative Fuel Pilot Plant and presents lessons learned from its design and construction. Electric Transportation Applications prepared this report under contract to the U.S. Department of Energy’s Advanced Vehicle Testing Activity. The Idaho National Engineering and Environmental Laboratory manages these activities for the Advanced Vehicle Testing Activity.

  14. Molecular screening of the ghrelin gene in Italian obese children: the Leu72Met variant is associated with an earlier onset of obesity.

    Science.gov (United States)

    Miraglia del Giudice, E; Santoro, N; Cirillo, G; Raimondo, P; Grandone, A; D'Aniello, A; Di Nardo, M; Perrone, L

    2004-03-01

    To test whether ghrelin variants could play a role in modulating some aspects of the obese phenotype during childhood. We screened the ghrelin gene in 300 Italian obese children and adolescents (mean age 10.5+/-3.2 y; range 4-19 y) and 200 controls by using the single-strand conformation polymorphism and the restriction fragment length polymoprhism analysis. No mutations were detected with the exception of two previously described polymorphisms, Arg51Gln and Leu72Met. For both variations, allelic frequencies were similar between patients and controls. Interestingly, we showed that the Leu72Met polymorphism was associated with differences in the age at obesity onset. Patients with the Met72 allele became obese earlier than homozygous patients for the wild Leu72 allele. The logrank test comparing the plots of the complement of Kaplan-Meier estimates between the two groups of patients was statistically significant (Pghrelin variations cause the obesity due to single-gene mutations. The Leu72Met polymorphism of the ghrelin gene seems to play a role in anticipating the onset of obesity among children suggesting, therefore, that ghrelin may be involved in the pathophysiology of human adiposity.

  15. Vibrational absorption spectra, DFT and SCC-DFTB conformational study and analysis of [Leu]enkephalin

    DEFF Research Database (Denmark)

    Abdali, Salim; Niehaus, T.A.; Jalkanen, Karl J.

    2003-01-01

    . Ab initio (DFT at the B3LYP/6-31G* level of theory) and semi-empirical (SCC-DFTB) with and without dispersion correction were applied to simulate the VA spectra of [Leu] enkephalin. In these calculations structures taken from X-ray measurements for different conformers of the molecule were used...

  16. Natural convection cooling of LEU cores for Pakistan research reactor-1

    International Nuclear Information System (INIS)

    Khan, L.A.; Bokhari, I.H.; Akhtar, K.M.

    1991-08-01

    The first high power and equilibrium LEU cores of PARR-1 have been analysed to assess the maximum operating power based on natural convection cooling, need for forced cooling to remove the decay heat and to estimate safety margins that commensurate with the predetermined power limit. Computer code NATCON and standard correlations have been used for the analysis. The parameters studied includes coolant velocity, temperature distribution in the core, heat fluxes at onset of nucleate boiling, pulsed boiling and burnup. (author)

  17. Leu72Met408 Polymorphism of the Ghrelin Gene Is Associated With Early Phase of Gastric Emptying in the Patients With Functional Dyspepsia in Japan.

    Science.gov (United States)

    Yamawaki, Hiroshi; Futagami, Seiji; Shimpuku, Mayumi; Shindo, Tomotaka; Maruki, Yuuta; Nagoya, Hiroyuki; Kodaka, Yasuhiro; Sato, Hitomi; Gudis, Katya; Kawagoe, Tetsuro; Sakamoto, Choitsu

    2015-01-01

    There are no available data about the relationship between ghrelin gene genotypes and early phase of gastric emptying in functional dyspepsia (FD) as defined by Rome III classification. We enrolled 74 patients presenting with typical symptoms of FD and 64 healthy volunteers. Gastric motility was evaluated using the 13C-acetate breath test. We used Rome III criteria to evaluate upper abdominal symptoms and self-rating questionnaires for depression (SRQ-D) scores to determine status of depression. The Arg51Gln (346G->A), preproghrelin (3056T->C), Leu72Met (408C->A), Gln90Leu (3412T->A) and G-protein 3 (825C->T) polymorphisms were analyzed in the DNA from blood samples of enrolled subjects. Genotyping was performed by polymerase chain reaction. There was a significant relationship between the Gln90Leu3412 genotype and SRQ-D score in FD patients (P = 0.009). Area under the curve at 15 minutes (AUC15) value was significantly associated with the Leu72Met408 genotype (P = 0.015) but not with entire gastric emptying. The Leu72Met (408C->A) single nucleotide polymorphism was significantly associated with early phase of gastric emptying in FD patients. Further studies will be necessary to clarify the association between ghrelin gene single nucleotide polymorphisms and early phase of gastric emptying in FD patients.

  18. Analysis of manganese superoxide dismutase (MnSOD: Ala-9Val and glutathione peroxidase (GSH-Px: Pro 197 Leu gene polymorphisms in mood disorders.

    Directory of Open Access Journals (Sweden)

    Birgül Elbozan Cumurcu

    2013-05-01

    Full Text Available We investigated the etiopathogenetic role of manganese superoxide dismutase (MnSOD (Ala-9Val and glutathione peroxidase (GSH-Px (Pro 197 Leu gene polymorphisms in patients diagnosed with major depressive disorder (MDD and bipolar I disorder (BD. Eighty patients with MDD, 82 patients with BD (total 162 patients and 96 healthy controls were enrolled in this study and genotyped using a Real Time-Quantitative Polymer Chain Reaction (RT-qPCR-based method. The patients with BD and MDD and the controls had a similar distribution of the genotypes and alleles in the Ala-9Val MnSOD gene polymorphism. Comparison of the MDD group and control group regarding the Pro197 Leu GSH-Px gene polymorphism revealed similar genotype distribution but different allele distribution. The BD group and control group were similar both for genotypes and for alleles when compared regarding the Pro 197 Leu GSH-Px gene polymorphism. The combined analysis (MDD plus BD also failed to find any association between the Ala-9Val MnSOD and Pro 197 Leu GSH-Px gene polymorphism. Although small statistical power of the current study the significant difference between patients with depression and the control group for the Pro 197 Leu GSH-Px polymorphism indicates that the distribution of these alleles may have a contribution in the physiopathogenesis of depression. One of the limitation of the current study is that the sample size is too small. Understanding of the exact role of Pro 197 LeuGSH-Px polymorphism in the development of depression needs to further studies with more sample size and high statistical power.

  19. Energy levels and quantum states of [Leu]enkephalin conformations based on theoretical and experimental investigations

    DEFF Research Database (Denmark)

    Abdali, Salim; Jensen, Morten Østergaard; Bohr, Henrik

    2003-01-01

    This paper describes a theoretical and experimental study of [Leu]enkephalin conformations with respect to the quantum estates of the atomic structure of the peptide. Results from vibrational absorption measurements and quantum calculations are used to outline a quantum picture and to assign vibr...

  20. The French UMo group contribution to new LEU fuel development

    International Nuclear Information System (INIS)

    Hamy, J.M.; Lemoine, P.; Huet, F.; Jarousse, C.; Emin, J.L.

    2005-01-01

    The French UMo Group was based on a close collaboration between CEA and AREVA's companies strongly involved in the MTR field. The aim of this program was to deliver industrially a high performance LEU UMo fuel able to be reprocessed, and suitable for a wide range of Research Reactor, covering the expected needs for MTR next generation. Since 1999, the program has been focused on industrial aspects with the intention to deal with the whole fuel cycle: manufacturing, irradiation behaviour, fuel characterisation, code development and reprocessing validation. It has been based on the fabrication of full-sized U-7%Mo fuel plates with a density up to 8 gU/cm 3 . The dedicated and advanced R and D means provided by the CEA have been used intensively with the contribution of HFR and BR2 facilities in Europe. This paper presents a synthesis of the program and the corresponding significant results obtained. These results have played a major role as regards the UMo dispersion fuel qualification route by issuing, for the first time, evidence of severe performance limitations. Consequently, the global international effort to develop and qualify a high density LEU UMo fuel has been definitively re-routed and forced to overcome these discrepancies by exploring new technical solutions. A French extended program sustained by a CEA and CERCA collaboration has been launched in 2004 in order to develop a suitable UMo fuel solution. UMo dispersion and monolithic fuel are both investigated through three new full-sized plate irradiations planned in OSIRIS. (author)

  1. Neutronic design of an ADS

    International Nuclear Information System (INIS)

    Cintas, A; Lopasso, E.M; Marquez Damian, J.I

    2009-01-01

    We present a LEU-ADS design based on an existing Argentine experimental facility, the RA-8 pool type zero power reactor. The versatility of this reactor allows measurement of different core configurations using different fuel enrichment, burnable poison rods, water perturbations and different control rods types in critical or subcritical configurations with an external source. To assess the feasibility of the LEU-ADS, multiplication factors, kinetic parameters, spectra, and time flux evolution were computed. Two external sources were considered: an isotopic 252 C f source, and a D-D pulsed neutron source. Parameters for different core configurations were calculated, and the feasibility of using continuous and pulsed neutron sources was verified. [es

  2. Conformational determination of [Leu]enkephalin based on theoretical and experimental VA and VCD spectral analyses

    DEFF Research Database (Denmark)

    Abdali, Salim; Jalkanen, Karl J.; Cao, X.

    2004-01-01

    Conformational determination of [Leu]enkephalin in DMSO-d6 is carried out using VA and VCD spectral analyses. Conformational energies, vibrational frequencies and VA and VCD intensities are calculated using DFT at B3LYP/6-31G* level of theory. Comparison between the measured spectra...

  3. Multilateral nonproliferation cooperation: US - Led effort to remove HEU/LEU fresh and spent fuels from the Republic of Georgia to Dounreay, Scotland

    International Nuclear Information System (INIS)

    Shelton, Thomas A.; Viebrock, James M.; Riedy, Alexander W.; Moses, Stanley D.; Bird, Helen M.

    1998-01-01

    This paper presents the efforts led by United States for removing HEU/LEU fresh and spent fuel from dhe Republic of Georgia to Dounreay, Scotland. These efforts are resulted from a plan approved by the United States Government, in cooperation with the United Kingdom and Georgia Governments to rapidly retrieve and transport circa 4.3 kilograms of enriched uranium. This material consisted largely of highly enriched uranium (HEU) and a small amount of low enriched uranium (LEU) fresh fuel, as well as about 800 grams of HEU/LEU-based spent fuel from a shutdown IR T-M research reactor on the outskirts of Table's, Georgia. The technical team lead by DOE consisted of HEU handling, packaging and transportation experts from the Oak Ridge Y-12 plant, managed and operated by Lockheed Martin Energy Systems, and fuel handling and transportation experts from Nac International in Norcross, Georgia, United States

  4. A new variation in the promoter region, the -604 C>T, and the Leu72Met polymorphism of the ghrelin gene are associated with protection to insulin resistance.

    Science.gov (United States)

    Zavarella, S; Petrone, A; Zampetti, S; Gueorguiev, M; Spoletini, M; Mein, C A; Leto, G; Korbonits, M; Buzzetti, R

    2008-04-01

    Previous studies suggested that polymorphisms in the coding region of the preproghrelin were involved in the etiology of obesity and might modulate glucose-induced insulin secretion. We evaluated the association of a new variation, -604C>T, in the promoter region of the ghrelin gene, of Leu72Met (247C>A) and of Gln90Leu (265A>T), all haplotype-tagging single nucleotide polymorphisms (SNPs), with measures of insulin sensitivity in 1420 adult individuals. The three SNPs were genotyped using ABI PRISM 7900 HT Sequence Detection System. We used multiple linear regression analysis for quantitative traits and THESIAS software for haplotype analysis. We observed a protective effect exerted by Met72 variant of Leu72Met SNP on insulin resistance parameters; a significant decreasing trend from Leu/Leu to Leu/Met and to Met/Met homozygous subjects in triglycerides, fasting insulin levels and HOMA-IR index (P=0.02, 0.01 and 0.003, respectively), and, consistently, an increase in ghrelin levels (P=0.003) was found. A significant decrease from CC to TC and to TT genotypes in insulin levels and HOMA-IR index was also detected (P=0.00l for both), but only in subjects homozygous for Leu72, where the protective effect of Met72 was not present. The haplotype analysis results supported the data obtained by the evaluation of each single SNP, showing the highest value of insulin levels and HOMA-IR index in the -604(c)247(c) haplotype intermediate value in -604(T)247(C) and lowest value in -604(C)247(A). Our observations suggest a protective role of the Met72 variant and of -604 T allele in modulating insulin resistance. These SNPs or an unknown functional variant in linkage disequilibrium could increase ghrelin levels and probably insulin sensitivity.

  5. Stimulation of Escherichia coli F-18Col- Type-1 fimbriae synthesis by leuX

    DEFF Research Database (Denmark)

    Newman, Joseph V.; Burghoff, Robert L.; Pallesen, Lars

    1994-01-01

    Escherichia coli F-18, a normal human fecal isolate, is an excellent colonizer of the streptomycin-treated mouse large intestine. E. coli F-18Col-, a derivative of E. coli F-18 which no longer makes the E. coli F-18 colicin, colonizes the large intestine as well as E. coli F-18 when fed to mice...... alone but is eliminated when fed together with E. coli F-18. Recently we randomly cloned E. coli F-18 DNA into E. coli F-18Col- and let the mouse intestine select the best colonizer. In this way, we isolated a 6.5-kb E. coli F-18 DNA sequence that simultaneously stimulated synthesis of type 1 fimbriae...... and enhanced E. coli F-18Col- colonizing ability. In the present investigation we show that the gene responsible for stimulation of type 1 fimbriae synthesis appears to be leuX, which encodes a tRNA specific for the rare leucine codon UUG. Moreover, it appears that expression of leuX may be regulated by two...

  6. Direct assessment of substrate binding to the Neurotransmitter:Sodium Symporter LeuT by solid state NMR

    DEFF Research Database (Denmark)

    Erlendsson, Simon; Gotfryd, Kamil; Larsen, Flemming Hofmann

    2017-01-01

    The Neurotransmitter:Sodium Symporters (NSSs) represent an important class of proteins mediating sodium-dependent uptake of neurotransmitters from the extracellular space. The substrate binding stoichiometry of the bacterial NSS protein, LeuT, and thus the principal transport mechanism, has been...

  7. Total System Performance Assessment: Enhanced Design Alternative V

    International Nuclear Information System (INIS)

    N. Erb; S. Miller; V. Vallikat

    1999-01-01

    This calculation documents the total system performance assessment modeling of Enhanced Design Analysis (EDA) V. EDA V is based on the TSPA-VA base design which has been modified with higher thermal loading, a quartz sand invert, and line loading with 21 PWR waste packages that have 2-cm thick titanium grade 7 corrosion resistance material (CRM) drip shields placed over dual-layer waste packages composed of 'inside out' VA reference material (CRWMS M and O 1999a). This document details the changes and assumptions made to the VA reference Performance Assessment Model (CRWMS M and O 1998a) to incorporate the design changes detailed for EDA V. The performance measure for this evaluation is expected value dose-rate history. Time histories of dose rate are presented for EDA V and a Defense in Depth (DID) analysis base on EDA V. Additional details concerning the Enhanced Design Alternative II are provided in the 'LADS 3-12 Requests' interoffice correspondence (CRWMS M and O 1999a)

  8. Irradiation of MEU and LEU test fuel elements in DR 3

    International Nuclear Information System (INIS)

    Haack, K.

    1984-01-01

    Irradiation of three MEU and three LEU fuel elements in the Danish reactor DR 3. Thermal and fast neutron flux density scans of the core have been made and the results, related to the U235-content of each fuel element, are compared with the values from HEU fuel elements. The test elements were taken to burn-up percentages of 50-60%. Reactivity values of the test elements at charge and at discharge have been measured and the values are compared with those of HEU fuel elements. (author)

  9. Hb Nouakchott [α114(GH2)Pro→Leu; HBA1: c.344C>T], A Second and Third Case Described in Two Unrelated Dutch Families

    NARCIS (Netherlands)

    Pondman, Kirsten M.; Brinkman, Jacoline W.; van der Straaten, Hanneke M.; Stroobants, An K.; Harteveld, Cornelis L.

    2018-01-01

    We report two families, members of which are carriers of a hemoglobin (Hb) variant previously described as Hb Nouakchott [α114(GH2)Pro→Leu; HBA1: c.344C>T; p.Pro115Leu]. In the first family of Dutch origin, the proband, a 32-year-old male and his 65-year-old father, were both carriers of Hb

  10. The Alternative Design Features for Safety Enhancement in Shutdown Operation

    International Nuclear Information System (INIS)

    Oh, Hae Cheol; Kim, Myung Ki; Chung, Bag Soon; Seo, Mi Ro

    2009-01-01

    PSA can be used to confirm that the new plant design is complied with the applicable safety goals, and to select among the alternate design options. A shutdown PSA provides insight for outage planning schedule, outage management practices, and design modifications. Considering the results of both LPSD PSA studies and operating experiences for low power and shutdown, the improvements can be proposed to reduce the high risk contribution. The improvements/enhancements during shutdown operation may be divided into categories such as hardware, administrative management, and operational procedure. This paper presents on an example how the risk related to an accidental situation can be reduced, focusing the hardware design changes for the newly designed NPPs

  11. Expert System Approach For Generating And Evaluating Engine Design Alternatives

    Science.gov (United States)

    Shen, Stewart N. T.; Chew, Meng-Sang; Issa, Ghassan F.

    1989-03-01

    Artificial intelligence is becoming an increasingly important subject of study for computer scientists, engineering designers, as well as professionals in other fields. Even though AI technology is a relatively new discipline, many of its concepts have already found practical applications. Expert systems, in particular, have made significant contributions to technologies in such fields as business, medicine, engineering design, chemistry, and particle physics. This paper describes an expert system developed to aid the mechanical designer with the preliminary design of variable-stroke internal-combustion engines. The expert system accomplished its task by generating and evaluating a large number of design alternatives represented in the form of graphs. Through the application of structural and design rules directly to the graphs, optimal and near optimal preliminary design configurations of engines are deduced.

  12. Experience in producing LEU fuel elements for the RSG-GAS

    International Nuclear Information System (INIS)

    Suripto, A.; Soentono, S.

    1991-01-01

    To achieve a self-reliance in the operation of the 30 MW Multipurpose Research Reactor at Serpong (the RSG-GAS), a fuel element production facility has been constructed nearby. The main task of the facility is to produce MTR type fuel and control elements containing U 3 O 8 -Al dispersion LEU fuel for the RSG-GAS. The hot commissioning activity has started in early 1988 after completion of the cold commissioning using depleted uranium in 1987, marking the beginning of the real production activity. This paper briefly describes the main features of the fuel production facility, the production experience gained so far, and its current production activity. (orig.)

  13. Nuclear criticality assessment of LEU and HEU fuel element storage

    International Nuclear Information System (INIS)

    Pond, R.B.; Matos, J.E.

    1984-01-01

    Criticality aspects of storing LEU (20%) and HEU (93%) fuel elements have been evaluated as a function of 235 U loading, element geometry, and fuel type. Silicide, oxide, and aluminide fuel types have been evaluated ranging in 235 U loading from 180 to 620 g per element and from 16 to 23 plates per element. Storage geometry considerations have been evaluated for fuel element separations ranging from closely packed formations to spacings of several centimeters between elements. Data are presented in a form in which interpolations may be made to estimate the eigenvalue of any fuel element storage configuration that is within the range of the data. (author)

  14. Comparison of HEU and LEU neutron spectra in irradiation facilities at the Oregon State TRIGA{sup ®} Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Schickler, R.A., E-mail: robert.schickler@oregonstate.edu; Marcum, W.R., E-mail: wade.marcum@oregonstate.edu; Reese, S.R.

    2013-09-15

    Highlights: • The Oregon State TRIGA{sup ®} Reactor neutron spectra is characterized herein. • Neutron spectra between highly enriched uranium and low enriched uranium cores are compared. • Discussion is given as to differences between HEU and LEU core spectra results and impact on experiments. -- Abstract: In 2008, the Oregon State TRIGA{sup ®} Reactor (OSTR) was converted from highly enriched uranium (HEU) fuel lifetime improvement plan (FLIP) fuel to low-enriched uranium (LEU) fuel. This effort was driven and supported by the Department of Energy's (DoE's) Reduced Enrichment for Research and Test Reactors (RERTR) program. The basis behind the RERTR program's ongoing conversion effort is to reduce the nuclear proliferation risk of civilian research and test reactors. The original intent of the HEU FLIP fuel was to provide fuel to research reactors that could be utilized for many years before a necessary refueling cycle. As a research reactor, the OSTR provides irradiation facilities for a variety of applications, such as activation analysis, fission-track dating, commercial isotope production, neutron radiography, prompt gamma characterization, and many others. In order to accurately perform these research functions, several studies had been conducted on the HEU FLIP fuel core to characterize the neutron spectra in various experimental facilities of the OSTR (Tiyapun, 1997; Ashbaker, 2005). As useful as these analyses were, they are no longer valid due to the change in fuel composition and the resulting alteration of core performance characteristics. Additionally, the core configuration (fuel reconfiguration) was altered between the HEU and LEU cores. This study characterizes the neutron spectra in various experimental facilities within and around the current LEU core. It also compares the spectra to that which was yielded in the HEU core through use of Monte Carlo n-Particle 5 (MCNP5) and experimental adjustment via a least

  15. Neutronic analysis of the conversion of HEU to LEU fuel for a 5-MW MTR core

    International Nuclear Information System (INIS)

    Pazirandeh, A.; Bartsch, G.

    1987-01-01

    In recent years, due to cessation of highly enriched uranium (HEU) fuel supply, practical steps have been taken to substitute HEU fuel in almost all research reactors by medium-enriched uranium or low-enriched uranium (LEU) fuels. In this study, a neutronic calculation of a 5-MW research reactor core fueled with HEU (93% 235 U) is presented. In order to assess the performance of the core with the LEU ( 235 U loadings were examined. The core consists of 22 standard fuel elements (SFEs) and 6 control fuel elements (CFEs). Each fuel elements has 18 curved plates of which two end plates are dummies. Initial 235 U content is 195 g 235 U/SFE and 9.7 g 235 U/CFE or /PFE. In all calculations the permitted changes to the fuel elements are (a) 18 active plates per SFE, (b) fuel plates assumed to be flat, and (c) 8 or 9 active plates per CFE

  16. Process of establishing design requirements and selecting alternative configurations for conceptual design of a VLA

    Directory of Open Access Journals (Sweden)

    Bo-Young Bae

    2017-04-01

    Full Text Available In this study, a process for establishing design requirements and selecting alternative configurations for the conceptual phase of aircraft design has been proposed. The proposed process uses system-engineering-based requirement-analysis techniques such as objective tree, analytic hierarchy process, and quality function deployment to establish logical and quantitative standards. Moreover, in order to perform a logical selection of alternative aircraft configurations, it uses advanced decision-making methods such as morphological matrix and technique for order preference by similarity to the ideal solution. In addition, a preliminary sizing tool has been developed to check the feasibility of the established performance requirements and to evaluate the flight performance of the selected configurations. The present process has been applied for a two-seater very light aircraft (VLA, resulting in a set of tentative design requirements and two families of VLA configurations: a high-wing configuration and a low-wing configuration. The resulting set of design requirements consists of three categories: customer requirements, certification requirements, and performance requirements. The performance requirements include two mission requirements for the flight range and the endurance by reflecting the customer requirements. The flight performances of the two configuration families were evaluated using the sizing tool developed and the low-wing configuration with conventional tails was selected as the best baseline configuration for the VLA.

  17. DART-TM: A thermomechanical version of DART for LEU VHD dispersed and monolithic fuel analysis

    International Nuclear Information System (INIS)

    Saliba, Roberto; Taboada, Horacio; Moscarda, Ma.Virginia; Rest, Jeff

    2003-01-01

    A collaboration agreement between ANL/USDOE and CNEA Argentina, in the area of Low Enriched Uranium Advanced Fuels has been in place since October 16, 1997 under the 'Implementation Arrangement for Technical Exchange and Cooperation in the Area of Peaceful Uses of Nuclear Energy'. An annex concerning DART code optimization has been operative since February 8, 1999. Previously, as a part of this annex a visual thermal FASTDART version was developed that includes mechanistic models for the calculation of the fission-gas-bubble and fuel particle size distribution, reaction layer thickness, and meat thermal conductivity. FASTDART was presented at the last RERTR Meeting that included validation against RERTR 3 irradiation data. The thermal FASTDART version was assessed as an adequate tool for modeling the behavior of LEU U-Mo dispersed fuels under irradiation against PIE RERTR irradiation data. During this past year the development of a 3-D thermo-mechanical version of the code for modeling the irradiation behavior of LEU U-Mo monolithic and dispersion fuel was initiated. Some preliminary results of this work will be shown during RERTR-2003 meeting. (author)

  18. Factor XIII Val34Leu is a genetic factor involved in the etiology of venous thrombosis

    NARCIS (Netherlands)

    Franco, R. F.; Reitsma, P. H.; Lourenço, D.; Maffei, F. H.; Morelli, V.; Tavella, M. H.; Araújo, A. G.; Piccinato, C. E.; Zago, M. A.

    1999-01-01

    A mutation in the factor XIII gene (FXIII Val34Leu) gene was recently reported to confer protection against myocardial infarction, but its relationship with venous thrombosis is unknown. In addition, a mutation in the 5'-untranslated region of the FXII gene (46 C->T) was identified which is

  19. OTTO-PAP: An alternative option to the PBMR fuelling philosophy

    International Nuclear Information System (INIS)

    Mulder, E.; Teuchert, E.

    1997-01-01

    Once Through Then Out, Power Adjusted by Poison (OTTO-PAP) fuelling of a high temperature pebble-bed reactor offers a simple alternative to the MEDUL (Mehrfachdurchlauf = German for multi-pass) fuelling regime followed in pebble bed reactor designs to date. The prerequisite for a modular reactor unit of maximum power output, subject to observing passive safety characteristics is a sufficiently flat axial neutron flux profile. This is achieved by introducing B 4 C coated particles of pre-calculated size and packing density within the fuel spheres. In accordance with AVR operating practise the temperature profile is radially equalised by introducing a 2-zone core loading. Adding pure graphite spheres loosely into the centre column area of the core effectively reduced the maximum power in the middle. Increasing the reactor diameter is enabled by the introduction of noses. A 3-D geometric modeller developed in cylindrical co-ordinates enables a given flow description of the pebbles adjacent to the nose boundaries and in the vicinity of the shut down/control rods. After translation of the geometric data the neutronic behaviour of the reactor is followed in 3-D by the CITATION code. This study is aimed towards achieving an optimal core layout with a LEU (Low Enriched Uranium) fuel cycle. Physical properties of the OTTO-PAP, 150 MWt reference design is reported, while computations performed observe results obtained by the reference HTR-MODUL design. (author)

  20. Pilot plant production at Riso of LEU silicide fuel for the Danish reactor DR3

    International Nuclear Information System (INIS)

    Toft, P.; Borring, J.; Adolph, E.

    1988-01-01

    A pilot plant for fabricating LEU silicide fuel elements has been established at Riso National Laboratory. Three test elements for the Danish reactor DR3 have been fabricated, based on 19.88% enriched U 3 Si 2 powder that has been purchased elsewhere. The pilot plant has been set up and 3 test elements fabricated without any major difficulties

  1. Simple and effective procedure for conformational search of macromolecules. Application to Met- and Leu-Enkephalin

    Energy Technology Data Exchange (ETDEWEB)

    Meirovitch, H.; Meirovitch, E. (Florida State Univ., Tallahassee, FL (United States)); Michel, A.G. (Institut de Recherches Serrier, Suresnes (France)); Vasquez, M. (Protein Design Lab., Mountain View, CA (United States))

    1994-06-23

    A simple and efficient method for searching the conformational space of macromolecules is presented. With this method an initial set of relatively low-energy structures is generated, and their energies are further minimized with a procedure that enables escaping from local energy minima. Illustrative calculations are described for Met- and Leu-enkephalin. 37 refs., 1 tab.

  2. Agonist properties of a stable hexapeptide analog of neurotensin, N alpha MeArg-Lys-Pro-Trp-tLeu-Leu (NT1).

    Science.gov (United States)

    Akunne, H C; Demattos, S B; Whetzel, S Z; Wustrow, D J; Davis, D M; Wise, L D; Cody, W L; Pugsley, T A; Heffner, T G

    1995-04-18

    The major signal transduction pathway for neurotensin (NT) receptors is the G-protein-dependent stimulation of phospholipase C, leading to the mobilization of intracellular free Ca2+ ([Ca2+]i) and the stimulation of cyclic GMP. We investigated the functional actions of an analog of NT(8-13), N alpha MeArg-Lys-Pro-Trp-tLeu-Leu (NT1), and other NT related analogs by quantitative measurement of the cytosolic free Ca2+ concentration in HT-29 (human colonic adenocarcinoma) cells using the Ca(2+)-sensitive dye fura-2/AM and by effects on cyclic GMP levels in rat cerebellar slices. The NT receptor binding affinities for these analogs to HT-29 cell membranes and newborn (10-day-old) mouse brain membranes were also investigated. Data obtained from HT-29 cell and mouse brain membrane preparations showed saturable single high-affinity sites and binding densities (Bmax) of 130.2 and 87.5 fmol/mg protein, respectively. The respective KD values were 0.47 and 0.39 nM, and the Hill coefficients were 0.99 and 0.92. The low-affinity levocabastine-sensitive site was not present (K1 > 10,000) in either membrane preparation. Although the correlation of binding between HT-29 cell membranes and mouse brain membranes was quite significant (r = 0.92), some of the reference agents had lower binding affinities in the HT-29 cell membranes. The metabolically stable compound NT1 plus other NT analogs and related peptides [NT, NT(8-13), xenopsin, neuromedin N, NT(9-13), kinetensin and (D-Trp11)-NT] increased intracellular Ca2+ levels in HT-29 cells, indicating NT receptor agonist properties. The effect of NT1 in mobilizing [Ca2+]i blocked by SR 48692, a non-peptide NT antagonist. Receptor binding affinities of NT analogs to HT-29 cell membranes were positively correlated with potencies for mobilizing intracellular calcium in the same cells. In addition, NT1 increased cyclic GMP levels in rat cerebellar slices, confirming the latter findings of its NT agonist action. These results substantiate

  3. A leukocyte antigen, Leu-13, is involved in induction of resistance of human cells to x-ray cell killing by interferon-α

    International Nuclear Information System (INIS)

    Kita, Kazuko; Zhai, Ling; Sugaya, Shigeru; Suzuki, Nobuo

    2003-01-01

    We previously reported on human interferon (HuIFN)-induced resistance of human cells to X-ray and UV cell killing. In this study, we searched for the genes whose expression is responsible for the resistance, using a PCR-based mRNA differential display method and Northern blotting analysis. RSa cells were used for this analysis, because they show increased resistance to X-ray- and UV-caused cell killing by HuIFN-α treatment prior to irradiation. Messenger RNA expression levels for Leu-13, a leukocyte antigen, were markedly up-regulated in RSa cells after HuIFN-α treatment. Furthermore, pretreatment of RSa cells with antisense oligonucleotides for Leu-13 mRNA resulted in the suppression of the HuIFN-α-induced resistance of the cells to X-ray cell killing, but did not modulate HuIFN-α-induced resistance to UV cell killing. These results suggest that Leu-13 is involved in HuIFN-α-induced resistance of human cells to X-ray cell killing, but not to UV cell killing. (author)

  4. TRIGA Research Reactor Conversion to LEU and Modernization of Safety Related Systems

    Energy Technology Data Exchange (ETDEWEB)

    Sanda, R. M. [Institute for Nuclear Research Piteşti (SCN-Piteşti), Piteşti (Romania)

    2014-08-15

    The USA and IAEA proposed an international programme to reduce the enrichment of uranium in research reactors by converting nuclear fuel containing HEU into fuel containing 20% enriched uranium. The Government of Romania joined the programme and actively supported political, scientific, technical and economic actions that led to the conversion of the active area of the 14 MW TRIGA reactor at the Institute for Nuclear Research in Piteşti in May 2006. This confirmed the continuity of the Romanian Government’s non-proliferation policy and their active support of international cooperation. Conversion of the Piteşti research reactor was made possible by completion of milestones in the Research Agreement for Reactor Conversion, a contract signed with the US Department of Energy and Argonne National Laboratory. This agreement provided scientific and technical support and the possibility of delivery of all HEU TRIGA fuel to the United States. Additionally, about 65% of the fresh LEU fuel needed to start the conversion was delivered in the period 1992–1994. Furthermore, conversion was promoted through IAEA Technical Cooperation project ROM/4/024 project funded primarily by the United States that supported technical and scientific efforts and the delivery of the remaining required LEU nuclear fuel to complete the conversion. Nuclear fuel to complete the conversion was made by the French company CERCA with a tripartite contract among the IAEA, CERCA and Romania. The contract was funded by the US Department of Energy with a voluntary contribution by the Romanian Government. The contract stipulated manufacturing and delivery of LEU fuel by CERCA with compliance measures for quality, delivery schedule and safety requirements set by IAEA standards and Romanian legislation. The project was supported by the ongoing technical cooperation, safeguards, legal and procurement assistance of the IAEA, in particular its Department of Nuclear Safety. For Romanian research, the

  5. A Sordaria macrospora mutant lacking the leu1 gene shows a developmental arrest during fruiting body formation.

    Science.gov (United States)

    Kück, Ulrich

    2005-10-01

    Developmental mutants with defects in fruiting body formation are excellent resources for the identification of genetic components that control cellular differentiation processes in filamentous fungi. The mutant pro4 of the ascomycete Sordaria macrospora is characterized by a developmental arrest during the sexual life cycle. This mutant generates only pre-fruiting bodies (protoperithecia), and is unable to form ascospores. Besides being sterile, pro4 is auxotrophic for leucine. Ascospore analysis revealed that the two phenotypes are genetically linked. After isolation of the wild-type leu1 gene from S. macrospora, complementation experiments demonstrated that the gene was able to restore both prototrophy and fertility in pro4. To investigate the control of leu1 expression, other genes involved in leucine biosynthesis specifically and in the general control of amino acid biosynthesis ("cross-pathway control") have been analysed using Northern hybridization and quantitative RT-PCR. These analyses demonstrated that genes of leucine biosynthesis are transcribed at higher levels under conditions of amino acid starvation. In addition, the expression data for the cpc1 and cpc2 genes indicate that cross-pathway control is superimposed on leucine-specific regulation of fruiting body development in the leu1 mutant. This was further substantiated by growth experiments in which the wild-type strain was found to show a sterile phenotype when grown on a medium containing the amino acid analogue 5-methyl-tryptophan. Taken together, these data show that pro4 represents a novel mutant type in S. macrospora, in which amino acid starvation acts as a signal that interrupts the development of the fruiting body.

  6. Influence of extracellular HCO3- and pH on lysine (LYS) and leucine (LEU) uptake and metabolism in swine renal tubules

    International Nuclear Information System (INIS)

    Patience, J.F.; Esteve-Garcia, E.; Austic, R.E.

    1986-01-01

    Fragments of renal tubules prepared by collagenase treatment of renal cortex were suspended to Krebs-Henseleit buffers which were modified to contain 10, 25 and 35 mM HCO 3 - at pH 7.4, or 25 mM HCO 3 - at pH 7.1, 7.4 and 7.7. Buffers were oxygenated with O 2 -CO 2 gas mixtures varying in carbon dioxide concentration prior to incubation. Approximately 100 mg tubules were incubated with shaking at 37 0 C for 30 min in serum-stoppered 25 ml Erlenmeyer flasks in 3.0 ml of buffer containing 0.1% dialyzed bovine serum albumin, 5 mM D-glucose and 0.3 mM L-[U- 14 C]-lysine or L-[1- 14 C]-leucine. The incorporation of carbon-14 into CO 2 and into 10% sulfosalicylic acid (SSA)-soluble and SSA-insoluble fractions of the incubation mixture was determined. Low (10mM) bicarbonate reduced the incorporation of lys and leu into protein but did not substantially affect the recovery of 14 CO 2 from either amino acid. High pH (7.7) resulted in reduced incorporation of lys and leu into protein, and decreased the oxidation of lys but not leu. The specific activity of lys (leu was not determined) in the SSA-soluble fraction was unaffected by bicarbonate or pH. The authors conclude that variations in extracellular pH and HCO 3 - (or pCO 2 ) affect the metabolism of amino acids by renal tubules and that low extracellular HCO 3 - (or pCO 2 ) may depress the incorporation of amino acids into protein

  7. Transition from HEU to LEU fuel in Romania's 14-MW TRIGA reactor

    International Nuclear Information System (INIS)

    Bretscher, M.M.; Snelgrove, J.L.

    1995-01-01

    The 14-MW TRIGA steady state reactor (SSR) located in Pitesti, Romania, first went critical in the fall of 1979. Initially, the core configuration for full power operation used 29 fuel clusters each containing a 5 x 5 square array of HEU U (10 wt% - ZrH - Er 2.8 wt%) fuel-moderator rods (1.295 cm o.d.) clad in Incoloy. With a total inventory of 35 HEU fuel clusters, burnup, considerations required a gradual expansion of the core from 29 to 32 and finally to 35 clusters before the reactor was shut down because of insufficient excess reactivity. At this time each of the original 29 fuel clusters had an average 235 U burnup in the range from 50 to 62%. Because of the U.S. policy regarding the export of highly enriched uranium, fresh HEU TRIGA replacement fuel is not available. After a number of safety-related measurements, the SSR is expected to resume full power operation in the near future using a mixed core containing five LEU TRIGA clusters of the same geometry as the original fuel but with fuel-moderator rods containing 45 wt% U (19.7% 235 U enrichment) and 1.1 wt% Er. Rods for 14 additional LEU fuel clusters will be fabricated by General Atomics. In support of the SSR mixed core operation numerous neutronic calculations have been performed. This paper presents some of the results of those calculations. (author)

  8. DESIGN OF ALTERNATIVE ENERGY SOURCES

    Directory of Open Access Journals (Sweden)

    Popa Stefania

    2013-11-01

    Full Text Available By energy sources we understand technologies and materials used to obtain various forms of energy necessary for the development of society. These sources must be in adequate quantities and be conveniently exploited in terms of technical, economic and sustainable perspective. Alternative energy uses the inherent power of natural sources like wind, tides, the sun. Alternative energy is a term used for some energy sources and energy storage technologies. Generally it indicates energies that are nontraditional and have low impact to the environment. The alternative energy term is used in contrast with the term fossil fuel according to some sources, while other sources use it with the meaning of renewable energy purposes.

  9. Detailed design, fabrication and testing of an engineering prototype compensated pulsed alternator. Final report

    International Nuclear Information System (INIS)

    Bird, W.L. Jr.; Woodson, H.H.

    1980-03-01

    The design, fabrication, and test results of a prototype compensated pulsed alternator are discussed. The prototype compulsator is a vertical shaft single phase alternator with a rotating armature and salient pole stator. The machine is designed for low rep rate pulsed duty and is sized to drive a modified 10 cm Beta amplifier. The load consists of sixteen 15 mm x 20 mm x 112 cm long xenon flashlamps connected in parallel. The prototype compulsator generates an open circuit voltage of 6 kV, 180 Hz, at a maximum design speed of 5400 rpm. At maximum speed, the inertial energy stored in the compulsator rotor is 3.4 megajoules

  10. Integrating multi-omics analyses of Nonomuraea dietziae to reveal the role of soybean oil in [(4'-OH)MeLeu]4-CsA overproduction.

    Science.gov (United States)

    Liu, Huanhuan; Huang, Di; Jin, Lina; Wang, Cheng; Liang, Shaoxiong; Wen, Jianping

    2017-07-14

    Nonomuraea dietziae is a promising microorganism to mediate the region-specific monooxygenation reaction of cyclosporine A (CsA). The main product [(4'-OH)MeLeu] 4 -CsA possesses high anti-HIV/HCV and hair growth-stimulating activities while avoiding the immunosuppressive effect of CsA. However, the low conversion efficiency restricts the clinical application. In this study, the production of [(4'-OH)MeLeu] 4 -CsA was greatly improved by 55.6% from 182.8 to 284.4 mg/L when supplementing soybean oil into the production medium, which represented the highest production of [(4'-OH)MeLeu] 4 -CsA so far. To investigate the effect of soybean oil on CsA conversion, some other plant oils (corn oil and peanut oil) and the major hydrolysates of soybean oil were fed into the production medium, respectively. The results demonstrated that the plant oils, rather than the hydrolysates, could significantly improve the [(4'-OH)MeLeu] 4 -CsA production, suggesting that soybean oil might not play its role in the lipid metabolic pathway. To further unveil the mechanism of [(4'-OH)MeLeu] 4 -CsA overproduction under the soybean oil condition, a proteomic analysis based on the two-dimensional gel electrophoresis coupled with MALDI TOF/TOF mass spectrometry was implemented. The results showed that central carbon metabolism, genetic information processing and energy metabolism were significantly up-regulated under the soybean oil condition. Moreover, the gas chromatography-mass spectrometry-based metabolomic analysis indicated that soybean oil had a great effect on amino acid metabolism and tricarboxylic acid cycle. In addition, the transcription levels of cytochrome P450 hydroxylase (CYP) genes for CsA conversion were determined by RT-qPCR and the results showed that most of the CYP genes were up-regulated under the soybean oil condition. These findings indicate that soybean oil could strengthen the primary metabolism and the CYP system to enhance the mycelium growth and the

  11. TWTF design alternates

    International Nuclear Information System (INIS)

    Ayers, A.L. Sr.

    1982-03-01

    The Transuranic Waste Treatment Facility (TWTF) will process transuranic (TRU) waste in retrievable storage at the Idaho National Engineering Laboratory (INEL). The costs for a TWTF concept using a slagging pyrolysis incinerator were excessive. Alternate concepts using a slow speed shredder, a rotary kiln incinerator, and concrete immobilization should result in significant cost reductions. These will be included in future TWTF considerations

  12. The use of LeuT as a model in elucidating binding sites for substrates and inhibitors in neurotransmitter transporters

    DEFF Research Database (Denmark)

    Løland, Claus Juul

    2015-01-01

    Background: The mammalian neurotransmitter transporters are complex proteins playing a central role in synaptic transmission between neurons by rapid reuptake of neurotransmitters. The proteins which transport dopamine, noradrenaline and serotonin belong to the Neurotransmitter:Sodium Symporters...... (NSS). Due to their important role, dysfunctions are associated with several psychiatric and neurological diseases and they also serve as targets for a wide range of therapeutic and illicit drugs. Despite the central physiological and pharmacological importance, direct evidence on structure......–function relationships on mammalian NSS proteins has so far been unsuccessful. The crystal structure of the bacterial NSS protein, LeuT, has been a turning point in structural investigations. Scope of review: To provide an update on what is known about the binding sites for substrates and inhibitors in the Leu...

  13. Alternatives generation and analysis for phase I intermediate waste feed staging system design requirements

    Energy Technology Data Exchange (ETDEWEB)

    Britton, M.D.

    1996-10-02

    This document provides; a decision analysis summary; problem statement; constraints, requirements, and assumptions; decision criteria; intermediate waste feed staging system options and alternatives generation and screening; intermediate waste feed staging system design concepts; intermediate waste feed staging system alternative evaluation and analysis; and open issues and actions.

  14. Predicting the effectiveness of road safety campaigns through alternative research designs.

    Science.gov (United States)

    Adamos, Giannis; Nathanail, Eftihia

    2016-12-01

    A large number of road safety communication campaigns have been designed and implemented in the recent years; however their explicit impact on driving behavior and road accident rates has been estimated in a rather low proportion. Based on the findings of the evaluation of three road safety communication campaigns addressing the issues of drinking and driving, seat belt usage, and driving fatigue, this paper applies different types of research designs (i.e., experimental, quasi-experimental, and non-experimental designs), when estimating the effectiveness of road safety campaigns, implements a cross-design assessment, and conducts a cross-campaign evaluation. An integrated evaluation plan was developed, taking into account the structure of evaluation questions, the definition of measurable variables, the separation of the target audience into intervention (exposed to the campaign) and control (not exposed to the campaign) groups, the selection of alternative research designs, and the appropriate data collection methods and techniques. Evaluating the implementation of different research designs in estimating the effectiveness of road safety campaigns, results showed that the separate pre-post samples design demonstrated better predictability than other designs, especially in data obtained from the intervention group after the realization of the campaign. The more constructs that were added to the independent variables, the higher the values of the predictability were. The construct that most affects behavior is intention, whereas the rest of the constructs have a lower impact on behavior. This is particularly significant in the Health Belief Model (HBM). On the other hand, behavioral beliefs, normative beliefs, and descriptive norms, are significant parameters for predicting intention according to the Theory of Planned Behavior (TPB). The theoretical and applied implications of alternative research designs and their applicability in the evaluation of road safety

  15. Production of annular blanks for Mo-99 using natural uranium, LEU uranium, nickel and structural Al-3003 plates

    International Nuclear Information System (INIS)

    Lisboa, J.R.; Barrera, M.E.; Marin, J.

    2010-01-01

    The Tc-99m radioisotope for medical use is the one most used in nuclear medicine worldwide. In Chile the Tc-99m is applied in more than 90% of nuclear medicine studies. In order to supply the whole country with this radioisotope, in 2005-2007 the CCHEN developed its own production of Tc-99m generators from Mo-99 imported from Canada, which are prepared with the activity needed by the Chilean hospitals and clinics. As of 2007 Mo-99 was no longer imported, and since then the Tc-99m is produced only by neutron activation of the Mo. The present challenge is to produce Mo-99 by irradiating blanks that contain enriched uranium foils, with locally produced LEU. The annular blank consists of 2 concentric tubes of A1-3003 structural aluminum that, in an interior annular space, contain a LEU foil, covered on both sides by a nickel foil. This work presents the development of the production technology for annular blanks using natural uranium and U-325 enriched uranium. The structural components are made with A1-3003 aluminum alloy, the foils are 13 grams of uranium measuring 100 x 50 mm and 120-150 μ thick. The blank was assembled using a methodology to control, adapt and assemble the blank's different internal components. A foil of natural uranium and LEU uranium, and a nickel foil are included, used as a barrier for the escape of fission products. During the blank's expansion, for analysis alcohol as lubricant was used, allowing the expander to move smoothly through the inside of the blank. The blank was sealed by TIG welding with a pulsed AC current and a mixture of Ar-5% He gases. Two methods were used for the water tightness test; for high escape levels the temperature was used as a promoter of the ΔP provided by hot water and liquid nitrogen, for low escape levels high vacuum technology was used where the ΔP is provided by a high pressure helium atmosphere. The technology for the production of annular LEU blanks was achieved by applying innovations to technologies

  16. Ser80Ile mutation and a concurrent Pro25Leu variant of the VHL gene in an extended Hungarian von Hippel-Lindau family

    Directory of Open Access Journals (Sweden)

    Fazakas Ferenc

    2008-04-01

    Full Text Available Abstract Von Hippel-Lindau disease (VHL is a rare autosomal dominant disease characterized by development of cystic and tumorous lesions at multiple sites, including the brain, spinal cord, kidneys, adrenals, pancreas, epididymis and eyes. The clinical phenotype results from molecular abnormalities of the VHL tumor suppressor gene, mapped to human chromosome 3p25-26. The VHL gene encodes two functionally active VHL proteins due to the presence of two translational initiation sites separated by 53 codons. The majority of disease-causing mutations have been detected downstream of the second translational initiation site, but there are conflicting data as to whether few mutations located in the first 53 codons, such as the Pro25Leu could have a pathogenic role. In this paper we report a large Hungarian VHL type 2 family consisting of 32 members in whom a disease-causing AGT80AAT (Ser80Ile c.239G>A, p.Ser80Ile mutation, but not the concurrent CCT25CTT (Pro25Leu c.74C>T, p.Pro25Leu variant co-segregated with the disease. To our knowledge, the Ser80Ile mutation has not been previously described in VHL type 2 patients with high risk of pheochromocytoma and renal cell cancer. Therefore, this finding represents a novel genotype-phenotype association and VHL kindreds with Ser80Ile mutation will require careful surveillance for pheochromocytoma. We concluded that the Pro25Leu variant is a rare, neutral variant, but the presence such a rare gene variant may make genetic counseling difficult.

  17. Simultaneous extraction of. beta. -endorphin and leu- and met-enkephalins from human and rat plasma

    Energy Technology Data Exchange (ETDEWEB)

    Bhathena, S.J.; Smith, P.M.; Kennedy, B.W. (Dept. of Agriculture, Beltsville, MD (USA)); Voyles, N.R.; Recant, L. (Diabetes Research Laboratory, Washington, DC (USA))

    1989-01-01

    A simple, rapid and reliable procedure is described to simultaneously concentrated and purify {beta}-endorphin, leu-and met-enkephalins from small volumes of human and rat plasma before radioimmunoassay is performed. It uses C{sub 18} Sep-Pak reverse phase cartridges. The effectiveness of different protease inhibitors in preventing degradation of opiates by plasma and different solvent systems for eluting opiates is also evaluated.

  18. Age-related decreases in the concentration of Met- and Leu-enkephalin and neurotensin in the basal ganglia or rats

    International Nuclear Information System (INIS)

    Ceballos, M.L. de; Boyce, S.; Taylor, M.; Jenner, P.; Marsden, C.D.

    1987-01-01

    Previous studies using radioimmunoassay procedures have failed to show age-related changes in the concentration of Met-and Leu-enkephalin or neurotensin in rat basal ganglia. In contrast, using a combined high-pressure liquid chromatography (HLPC)- radioimmunoassay (RIA) technique we now report considerable decreases in the levels of these neuropeptides in areas of basal ganglia of 22 months-old compared to 3 months-old male Wistar rats. The concentration of Met-enkephalin was greatly reduced in the striatum and nucleus accumbens, but not in substantia nigra, of old compared to young animals. There was a similarly large decrease in Leu-enkephalin content in striatum of old rats with less marked decreases occurring in both the nucleus accumbens and substantia nigra. Neurotensin levels in the striatum and substantia nigra were greatly reduced in old rats, with a less marked decrease in the nucleus accumbens

  19. Age-related decreases in the concentration of Met- and Leu-enkephalin and neurotensin in the basal ganglia or rats

    Energy Technology Data Exchange (ETDEWEB)

    Ceballos, M.L. de; Boyce, S; Taylor, M; Jenner, P; Marsden, C D

    1987-03-20

    Previous studies using radioimmunoassay procedures have failed to show age-related changes in the concentration of Met-and Leu-enkephalin or neurotensin in rat basal ganglia. In contrast, using a combined high-pressure liquid chromatography (HLPC)- radioimmunoassay (RIA) technique we now report considerable decreases in the levels of these neuropeptides in areas of basal ganglia of 22 months-old compared to 3 months-old male Wistar rats. The concentration of Met-enkephalin was greatly reduced in the striatum and nucleus accumbens, but not in substantia nigra, of old compared to young animals. There was a similarly large decrease in Leu-enkephalin content in striatum of old rats with less marked decreases occurring in both the nucleus accumbens and substantia nigra. Neurotensin levels in the striatum and substantia nigra were greatly reduced in old rats, with a less marked decrease in the nucleus accumbens.

  20. Analysis of alternative light water reactor (LWR) fuel cycles

    International Nuclear Information System (INIS)

    Heeb, C.M.; Aaberg, R.L.; Boegel, A.J.; Jenquin, U.P.; Kottwitz, D.A.; Lewallen, M.A.; Merrill, E.T.; Nolan, A.M.

    1979-12-01

    Nine alternative LWR fuel cycles are analyzed in terms of the isotopic content of the fuel material, the relative amounts of primary and recycled material, the uranium and thorium requirements, the fuel cycle costs and the fraction of energy which must be generated at secured sites. The fuel materials include low-enriched uranium (LEU), plutonium-uranium (MOX), highly-enriched uranium-thorium (HEU-Th), denatured uranium-thorium (DU-Th) and plutonium-thorium (Pu-Th). The analysis is based on tracing the material requirements of a generic pressurized water reactor (PWR) for a 30-year period at constant annual energy output. During this time period all the created fissile material is recycled unless its reactivity worth is less than 0.2% uranium enrichment plant tails

  1. A Mixed-Oxide Assembly Design for Rapid Disposition of Weapons Plutonium in Pressurized Water Reactors

    International Nuclear Information System (INIS)

    Alonso, Gustavo; Adams, Marvin L.

    2002-01-01

    We have created a new mixed-oxide (MOX) fuel assembly design for standard pressurized water reactors (PWRs). Design goals were to maximize the plutonium throughput while introducing the lowest perturbation possible to the control and safety systems of the reactor. Our assembly design, which we call MIX-33, offers some advantages for the disposition of weapons-grade plutonium; it increases the disposition rate by 8% while increasing the worth of control material, compared to a previous Westinghouse design. The MIX-33 design is based upon two ideas: the use of both uranium and plutonium fuel pins in the same assembly, and the addition of water holes in the assembly. The main result of this paper is that both of these ideas are effective at increasing Pu throughput and increasing the worth of control material. With this new design, according to our analyses, we can transition smoothly from a full low-enriched-uranium (LEU) core to a full MIX-33 core while meeting the operational and safety requirements of a standard PWR. Given an interruption of the MOX supply, we can transition smoothly back to full LEU while meeting safety margins and using standard LEU assemblies with uniform pinwise enrichment distribution. If the MOX supply is interrupted for only one cycle, the transition back to a full MIX-33 core is not as smooth; high peaking could cause power to be derated by a few percent for a few weeks at the beginning of one transition cycle

  2. GPX1 Pro(198)Leu polymorphism, erythrocyte GPX activity, interaction with alcohol consumption and smoking, and risk of colorectal cancer

    DEFF Research Database (Denmark)

    Hansen, Rikke Dalgaard; Krath, Britta N.; Frederiksen, Kirsten

    2009-01-01

    polymorphism and several lifestyle factors predict GPX activity in erythrocytes. The present study was nested within the prospective “Diet, Cancer and Health” study of 57,053 Danes including 375 colorectal cancer cases and a comparison group of 779 individuals matched on gender. Biomaterial was sampled...... and information on lifestyle factors was obtained from questionnaires filled in at enrolment in 1993–1997. GPX1 Pro198Leu, hOGG1 Ser326Cys and erythrocyte GPX enzyme activity were not associated with risk of colorectal cancer. We observed a higher risk associated with alcohol consumption and smoking among......198Leu genotype, gender, smoking intensity, and intake of fruits and vegetables. Our results indicate that lifestyle-related oxidative stress may be a risk factor for colorectal cancer among subjects with a lowered defence....

  3. The beginning of the LEU fuel elements manufacturing in the Chilean Commission of Nuclear Energy

    International Nuclear Information System (INIS)

    Contreras, H.; Chavez, J.C.; Marin, J.; Lisboa, J.; Olivares, L.; Jimenez, O.

    1998-01-01

    The U 3 Si 2 LEU fuel fabrication program at CCHEN has started with the assembly of four leaders fuel elements for the RECH-1 reactor. This activity has involved a stage of fuel plates qualification, to evaluate fabrication procedures and quality controls and quality assurance. The qualification extent was 50% of the fuel plates, equivalent to the number of plates required for the assembly of two fuel elements. (author)

  4. Full core operation in JRR-3 with LEU fuels

    International Nuclear Information System (INIS)

    Murayama, Y.; Issiki, M.

    1995-01-01

    The new JRR-3 a 20MWT swimming pool type research reactor, is made up of plate type LEU fuel elements with U-Al x fuel at 2.2 gU/cm 3 . Reconstruction work for the new JR-3 was a good success, and common operation started in November 1990, and 7 cycles (26 days operation/cycle) have passed. We have no experience in using such a high uranium density fuel element with aluminide fuel. So we plan to examine the condition of the irradiated fuel elements with three methods, that is, measurement of the value of FFD in operation, observation of external view of the fuels in refueling work and postirradiation examination after maximum burn-up will be established. In the results of the first two methods, the fuel elements of JRR-3 is burned up normally and have no evidence of failure. (author)

  5. Single-Case Research Design: An Alternative Strategy for Evidence-Based Practice

    Science.gov (United States)

    Stapleton, Drue; Hawkins, Andrew

    2015-01-01

    Objective: The trend of utilizing evidence-based practice (EBP) in athletic training is now requiring clinicians, researchers, educators, and students to be equipped to both engage in and make judgments about research evidence. Single-case design (SCD) research may provide an alternative approach to develop such skills and inform clinical and…

  6. The Leu72Met Polymorphism of the Prepro-ghrelin Gene is Associated With Alcohol Consumption and Subjective Responses to Alcohol: Preliminary Findings.

    Science.gov (United States)

    Suchankova, Petra; Yan, Jia; Schwandt, Melanie L; Stangl, Bethany L; Jerlhag, Elisabet; Engel, Jörgen A; Hodgkinson, Colin A; Ramchandani, Vijay A; Leggio, Lorenzo

    2017-07-01

    The orexigenic peptide ghrelin may enhance the incentive value of food-, drug- and alcohol-related rewards. Consistent with preclinical findings, human studies indicate a role of ghrelin in alcohol use disorders (AUD). In the present study an a priori hypothesis-driven analysis was conducted to investigate whether a Leu72Met missense polymorphism (rs696217) in the prepro-ghrelin gene (GHRL), is associated with AUD, alcohol consumption and subjective responses to alcohol. Association analysis was performed using the National Institute on Alcohol Abuse and Alcoholism (NIAAA) clinical sample, comprising AUD individuals and controls (N = 1127). Then, a post-hoc analysis using data from a human laboratory study of intravenous alcohol self-administration (IV-ASA, N = 144) was performed to investigate the association of this SNP with subjective responses following a fixed dose of alcohol (priming phase) and alcohol self-administration (ad libitum phase). The case-control study revealed a trend association (N = 1127, OR = 0.665, CI = 0.44-1.01, P = 0.056) between AUD diagnosis and Leu72Met. In AUD subjects, the SNP was associated with significantly lower average drinks per day (n = 567, β = -2.49, 95% CI = -4.34 to -0.64, P = 0.008) and significantly fewer heavy drinking days (n = 567, β = -12.00, 95% CI = -19.10 to -4.89, P polymorphism in the prepro-ghrelin gene, is associated with alcohol use disorder, alcohol consumption and subjective responses to alcohol. Although preliminary, results suggest that the Leu72Leu genotype may lead to increased risk of alcohol use disorder possibly via mechanisms involving a lower response to alcohol. Medical Council on Alcohol and Oxford University Press 2017. This work is written by (a) US Government employee(s) and is in the public domain in the US.

  7. HEU benchmark calculations and LEU preliminary calculations for IRR-1

    International Nuclear Information System (INIS)

    Caner, M.; Shapira, M.; Bettan, M.; Nagler, A.; Gilat, J.

    2004-01-01

    We performed neutronics calculations for the Soreq Research Reactor, IRR-1. The calculations were done for the purpose of upgrading and benchmarking our codes and methods. The codes used were mainly WIMS-D/4 for cell calculations and the three dimensional diffusion code CITATION for full core calculations. The experimental flux was obtained by gold wire activation methods and compared with our calculated flux profile. The IRR-1 is loaded with highly enriched uranium fuel assemblies, of the plate type. In the framework of preparation for conversion to low enrichment fuel, additional calculations were done assuming the presence of LEU fresh fuel. In these preliminary calculations we investigated the effect on the criticality and flux distributions of the increase of U-238 loading, and the corresponding uranium density.(author)

  8. Structural optimization of an alternate design for the Space Shuttle solid rocket booster field joint

    Science.gov (United States)

    Barthelemy, Jean-Francois M.; Rogers, James L., Jr.; Chang, Kwan J.

    1987-01-01

    A structural optimization procedure is used to determine the shape of an alternate design for the Shuttle's solid rocket booster field joint. In contrast to the tang and clevis design of the existing joint, this alternate design consists of two flanges bolted together. Configurations with 150 studs of 1 1/8 in diameter and 135 studs of 1 3/16 in diameter are considered. Using a nonlinear programming procedure, the joint weight is minimized under constraints on either von Mises or maximum normal stresses, joint opening and geometry. The procedure solves the design problem by replacing it by a sequence of approximate (convex) subproblems; the pattern of contact between the joint halves is determined every few cycles by a nonlinear displacement analysis. The minimum weight design has 135 studs of 1 3/16 in diameter and is designed under constraints on normal stresses. It weighs 1144 lb per joint more than the current tang and clevis design.

  9. Detection of (Leu-7)-positive cells with NK activity in human gingival tissues from patients with periodontitis

    International Nuclear Information System (INIS)

    Komiyama, K.; Hirsch, H.Z.; Mestecky, J.; Moro, I.

    1986-01-01

    Natural killer (NK) cells have been identified in peripheral blood, lymphoid tissue and more recently in gut mucosa and may be involved in the regulation of immunoglobulin synthesis. They have assayed gingival tissues obtained from 25 periodontitis patients, for the presence and activity of NK cells. Routine histological techniques demonstrated an inflammatory infiltrate dominated by plasma cells and B lymphocytes. Indirect staining procedures with a biotin-labeled mouse anti-human, Leu-7 antibody revealed the presence of numerous positive cells accompanying the inflammatory cellular infiltrate in perivascular areas. Several specimens demonstrated positive-staining cells in the epithelium as well. Few cells were observed in histologically uninflammed areas. Single cell suspension obtained by collagenase digestion of 5 gingival samples were used in 51 Cr release cytotoxicity assay against K562 cells. Three of the five samples were positive in this assay. The finding of Leu-7-positive cells in areas of intense plasma cell foci but not in uninflammed areas, may support a role for these cells in the regulation of immunoglobulin synthesis in oral mucosal tissues

  10. Detection of (Leu-7)-positive cells with NK activity in human gingival tissues from patients with periodontitis

    Energy Technology Data Exchange (ETDEWEB)

    Komiyama, K.; Hirsch, H.Z.; Mestecky, J.; Moro, I.

    1986-03-05

    Natural killer (NK) cells have been identified in peripheral blood, lymphoid tissue and more recently in gut mucosa and may be involved in the regulation of immunoglobulin synthesis. They have assayed gingival tissues obtained from 25 periodontitis patients, for the presence and activity of NK cells. Routine histological techniques demonstrated an inflammatory infiltrate dominated by plasma cells and B lymphocytes. Indirect staining procedures with a biotin-labeled mouse anti-human, Leu-7 antibody revealed the presence of numerous positive cells accompanying the inflammatory cellular infiltrate in perivascular areas. Several specimens demonstrated positive-staining cells in the epithelium as well. Few cells were observed in histologically uninflammed areas. Single cell suspension obtained by collagenase digestion of 5 gingival samples were used in /sup 51/Cr release cytotoxicity assay against K562 cells. Three of the five samples were positive in this assay. The finding of Leu-7-positive cells in areas of intense plasma cell foci but not in uninflammed areas, may support a role for these cells in the regulation of immunoglobulin synthesis in oral mucosal tissues.

  11. Creating An Alternative Design for Asita Corporate Identity

    Directory of Open Access Journals (Sweden)

    Michelle Elise

    2015-10-01

    Full Text Available The objective of the study is to find the solution to the problem outlined, which is to create an alternative design for corporate identity of ASITA. ASITA is a non-profit organization to foster tours and travel agencies in Indonesia. The writer conducted interview to the ASITA Jakarta Chapter, which was appointed to represent ASITA in providing the data needed by the writer. The writer interviewed the advisor of the organization, which had once served as chairperson of ASITA. The result of the research is new corporate identity system of ASITA based on a concept that ASITA as an organization, serves as a compass that guides and assists in every direction. The writer found that corporate identity is an important element to define an organization as well as giving impact on its first impression. To create good corporate identity, several things such as elements of design, color, typography, etc need to be put into attention. 

  12. Fabrication, fabrication control and in-core follow up of 4 LEU leader fuel elements based on U3Si2 in RECH-1

    International Nuclear Information System (INIS)

    Chavez, J.C.; Barrera, M.; Olivares, L.; Lisboa, J.

    1999-01-01

    The RECH-1 MTR reactor has been converted from HEU to MEU (45% enrichment) and the decision to a LEU (20% enrichment) conversion was taken some years ago. This LEU conversion decision involved a local fuel development and fabrication based on U 3 Si 2 -Al dispersion fuel, and a fabrication qualification stage that resulted in four fuel elements fully complying with established fabrication standards for this type of fuel. This report-presents relevant points of these four leaders fuel elements fabrication, in particular a fuel plate core homogeneity control development. A summary of the intended in core follow-up studies for the leaders fuel elements is also presented here. (author)

  13. Retrofitting a spent fuel pool spray system for alternative cooling as a strategy for beyond design basis events

    Energy Technology Data Exchange (ETDEWEB)

    Hartmann, Christoph; Vujic, Zoran [Westinghouse Electric Germany GmbH, Mannheim (Germany)

    2017-06-15

    Due to requirements for nuclear power plants to withstand beyond design basis accidents, including events such as happened in 2011 in the Fukushima Daiichi Nuclear Power Plant in Japan, alternative cooling of spent fuel is needed. Alternative spent fuel cooling can be provided by a retrofitted spent fuel pool spray system based on the AP1000 plant design. As part of Krsko Nuclear Power Plant's Safety Upgrade Program, Krsko Nuclear Power Plant decided on, and Westinghouse successfully designed a retrofit of the AP1000 {sup registered} plant spent fuel pool spray system to provide alternative spent fuel cooling.

  14. GLUTATHIONE PEROXIDASE-1 PRO200LEU POLYMORPHISM (RS1050450) IS ASSOCIATED WITH MORBID OBESITY INDEPENDENTLY OF THE PRESENCE OF PREDIABETES OR DIABETES IN WOMEN FROM CENTRAL MEXICO.

    Science.gov (United States)

    Hernández Guerrero, César; Hernández Chávez, Paulina; Martínez Castro, Noemí; Parra Carriedo, Alicia; García Del Rio, Sandra; Pérez Lizaur, Ana

    2015-10-01

    obesity affects more than a third of Mexican population. Oxidative stress participates actively in the etiology of this phenomenon. Glutathione peroxidase-1 (GPX-1) plays a protective role against oxidative stress. The SNP Pro200Leu (rs10504050) has been reported to affect the activity of the enzyme. to determine the frequency of rs10504050 polymorphism in women with obesity and normal weight control, asses the concentration of peripheral TBARS and evaluate the consumption of pro and antioxidants. 104 women with obesity and 70 healthy controls (CG) were included in the study. Anthropometric, biochemical, clinical and dietary features were evaluated. GPx-1 rs10504050 was determined by PCR/RFLP method. TBARS was assayed spectrophotometrically in plasma. The subjects were stratified and compared by obesity grades and by subgroups of prediabetes and diabetes condition. Statistical analysis included ANOVA of Kruskal Wallis, Xi squared and Pearson correlation. for rs10504050 polymorphism there were differences (Xi2 = 6; p = 0.01) between frequency (0.61) of obese carriers (Pro/Leu plus Leu/Leu) and CG carriers (0.42), and between (Xi2 = 8; p = 0.004) morbid (IMC > 40) obesity (0.74) and CG carriers. The obese group (OB) showed a prevalence of 66% of prediabetes plus diabetes. There were no differences in frequencies of rs10504050 in OB with pre or diabetes versus CG, or versus obese participants without diabetes. TBARS concentration was greater in all the degrees of OB versus CG. GPx-1 Pro200Leu polymorphism was associated with obesity especially with morbid obesity, but not with obese participants with prediabetes or diabetes. Oxidative stress is present in all grades of obesity significantly. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

  15. No association of the Arg51Gln and Leu72Met polymorphisms of the ghrelin gene and polycystic ovary syndrome.

    Science.gov (United States)

    Wang, Kehua; Wang, Leiguang; Zhao, Yueran; Shi, Yuhua; Wang, Laicheng; Chen, Zi-Jiang

    2009-02-01

    Ghrelin plays a role in regulating glucose metabolism and energy balance. Polymorphisms in preproghrelin and ghrelin gene could be responsible for obesity, insulin resistance and low ghrelin levels observed in some individuals. The objective of this study was to evaluate the influence of two single-nucleotide polymorphisms (SNPs) of ghrelin gene on the clinical, the hormonal and metabolic features in women with polycystic ovary syndrome (PCOS) in a Chinese population. A large sample of Chinese PCOS (n = 271) women and a control group (n = 296) of healthy women matched for age were studied. Hormone and metabolic profiles were measured and blood samples were collected for genotype and allelic frequency analysis. Non-synonymous SNPs in the coding region (exon 2) of the preproghrelin gene (Arg51Gln (346 G>A) and Leu72Met (408 C>A) were studied using PCR and restriction fragment length polymorphism analysis. The polymorphism Arg51Gln was not found in the cohorts studied. The distribution of Leu72Met was similar in PCOS group and in healthy controls. There was no significant difference in age, BMI, waist-hip-ratio and levels of FSH, LH, estradiol, testosterone and prolactin between PCOS patients with different genotypes, and the level of plasma glucose and insulin was also similar. No association was found between Leu72Met and Arg51Gln polymorphisms in the ghrelin gene and PCOS in Chinese population.

  16. Alternative bipolar plates design and manufacturing for PEM fuel cell

    International Nuclear Information System (INIS)

    Lee Chang Chuan; Norhamidi Muhamad; Jaafar Sahari

    2006-01-01

    Bipolar plates is one of the important components in fuel cell stack, it comprise up to 80% of the stack volume. Traditionally, these plates have been fabricated from graphite, owing to its chemical nobility, and high electrical and thermal conductivity; but these plates are brittle and relatively thick. Therefore increasing the stack volume and size. Alternatives to graphite are carbon-carbon composite, carbon-polymer composite and metal (aluminum, stainless steel, titanium and nickel based alloy). The use of coated and uncoated metal bipolar plates has received attention recently due to the simplicity of plate manufacturing. The thin nature of the metal substrate allows for smaller stack design with reduced weight. Lightweight coated metals as alternative to graphite plate is being developed. Beside the traditional method of machining and slurry molding, metal foam for bipolar plates fabrication seems to be a good alternative. The plates will be produced with titanium powder by Powder Metallurgy method using space holders technique to produce the meal foam flow-field. This work intends to facilitate the materials and manufacturing process requirements to produce cost effective foamed bipolar plates for fuel cell

  17. Sustainable covers for uranium mill tailings, USA: alternative design, performance, and renovation - 16369

    International Nuclear Information System (INIS)

    Waugh, William J.; Benson, Craig H.; Albright, William H.

    2009-01-01

    The U.S. Department of Energy Office of Legacy Management is investigating alternatives to conventional cover designs for uranium mill tailings. A cover constructed in 2000 near Monticello, Utah, USA, was a redundant design with a conventional low-conductivity composite cover overlain with an alternative cover designed to mimic the natural soil water balance as measured in nearby undisturbed native soils and vegetation. To limit percolation, the alternative cover design relies on a 160-cm layer of sandy clay loam soil overlying a 40- cm sand capillary barrier for water storage, and a planting of native sagebrush steppe vegetation to seasonally release soil water through evapotranspiration (ET). Water balance monitoring within a 3.0-ha drainage lysimeter, embedded in the cover during construction, provided convincing evidence that the cover has performed well over a 9-year period (2000- 2009). The total cumulative percolation, 4.8 mm (approximately 0.5 mm yr -1 ), satisfied a regulatory goal of -1 . Most percolation can be attributed to the very wet winter and spring of 2004-2005, when soil water content exceeded the storage capacity of the cover. Diversity, percent cover, and leaf area of vegetation increased over the monitoring period. Field and laboratory evaluations several years after construction show that soil structural development, changes in soil hydraulic properties, and development of vegetation patterns have not adversely impacted cover performance. A new test facility was constructed in 2008 near Grand Junction, Colorado, USA, to evaluate low-cost methods for renovating or transforming conventional covers into more sustainable ET covers. (authors)

  18. Calculation of drift seepage for alternative emplacement designs

    International Nuclear Information System (INIS)

    Li, Guomin; Tsang, Chin-Fu; Birkholzer, Jens

    1999-01-01

    The calculations presented in this report are performed to obtain seepage rates into drift and boreholes for two alternative designs of drift and waste emplacement at Yucca Mountain. The two designs are defined according to the Scope of Work 14012021M1, activity 399621, drafted October 6, 1998, and further refined in a conference telephone call on October 13, 1998, between Mark Balady, Jim Blink, Rob Howard and Chin-Fu Tsang. The 2 designs considered are: (1) Design A--Horizontal boreholes 1.0 m in diameter on both sides of the drift, with each borehole 8 m long and inclined to the drift axis by 30 degrees. The pillar between boreholes, measured parallel to the drift axis, is 3.3 m. In the current calculations, a simplified model of an isolated horizontal borehole 8 m long will be simulated. The horizontal borehole will be located in a heterogeneous fracture continuum representing the repository layer. Three different realizations will be taken from the heterogeneous field, representing three different locations in the rock. Seepage for each realization is calculated as a function of the percolation flux. Design B--Vertical boreholes, 1.0 m in diameter and 8.0 m deep, drilled from the bottom of an excavated 8.0 m diameter drift. Again, the drift with the vertical borehole will be assumed to be located in a heterogeneous fracture continuum, representing the rock at the repository horizon. Two realizations are considered, and seepage is calculated for the 8-m drift with and without the vertical 1-m borehole at its bottom

  19. RIP Input From WAPDEG for LA Design Selection: Enhanced Design Alternative II

    International Nuclear Information System (INIS)

    B.E. Bullard

    1999-01-01

    The purpose of this analysis is to identify and analyze concepts for the acquisition of data in support of the Performance Confirmation (PC) program at the potential subsurface nuclear waste repository at Yucca Mountain. This analysis is being prepared to document an investigation of design concepts, current available technology, technology trends, and technical issues associated with data acquisition during the PC period. This analysis utilizes the ''Performance Confirmation Plan'' (CRWMS M and O 2000b) to help define the scope for the PC data acquisition system. The focus of this analysis is primarily on the PC period for a minimum of 30 years after emplacement of the last waste package. The design of the data acquisition system shall allow for a closure deferral up to 300 years from initiation of waste emplacement. (CRWMS M and O 2000h, page 5-1). This analysis is a revision to and supercedes analysis, ''Performance Confirmation Data Acquisition System'', DI No. BCAI00000-017 17-0200-00002 Rev 00 (CRWMS M and O 1997), and incorporates the latest repository design changes following the M and O and DOE evaluation of a series of Enhanced Design Alternatives (EDAs), as described in the ''Enhanced Design Alternatives II Report'' (CRWMS M and O 1999d). Significant design changes include: thermal line loading of the emplacement drifts, closer spacing of the waste packages (WPs), wider spacing and fewer emplacement drifts, continuous ventilation of all active emplacement drifts, thinner walled WP designs which will increase external radiation levels, a 50-year repository closure option, inclusion of a drip-shield, exclusion of backfill, and new conceptual designs for the waste emplacement vehicles and equipment (Stroupe 2000). The scope and primary objectives of this analysis are to: (1) Review the criteria for design as presented in the Performance Confirmation Data Acquisition/Monitoring System Description Document, by way of the Input Transmittal, ''Performance

  20. A comparison of alternative 60-mer probe designs in an in-situ synthesized oligonucleotide microarray

    Directory of Open Access Journals (Sweden)

    Fairbanks Benjamin D

    2006-04-01

    Full Text Available Abstract Background DNA microarrays have proven powerful for functional genomics studies. Several technologies exist for the generation of whole-genome arrays. It is well documented that 25mer probes directed against different regions of the same gene produce variable signal intensity values. However, the extent to which this is true for probes of greater length (60mers is not well characterized. Moreover, this information has not previously been reported for whole-genome arrays designed against bacteria, whose genomes may differ substantially in characteristics directly affecting microarray performance. Results We report here an analysis of alternative 60mer probe designs for an in-situ synthesized oligonucleotide array for the GC rich, β-proteobacterium Burkholderia cenocepacia. Probes were designed using the ArrayOligoSel3.5 software package and whole-genome microarrays synthesized by Agilent, Inc. using their in-situ, ink-jet technology platform. We first validated the quality of the microarrays as demonstrated by an average signal to noise ratio of >1000. Next, we determined that the variance of replicate probes (1178 total probes examined of identical sequence was 3.8% whereas the variance of alternative probes (558 total alternative probes examined designs was 9.5%. We determined that depending upon the definition, about 2.4% of replicate and 7.8% of alternative probes produced outlier conclusions. Finally, we determined none of the probe design subscores (GC content, internal repeat, binding energy and self annealment produced by ArrayOligoSel3.5 were predictive or probes that produced outlier signals. Conclusion Our analysis demonstrated that the use of multiple probes per target sequence is not essential for in-situ synthesized 60mer oligonucleotide arrays designed against bacteria. Although probes producing outlier signals were identified, the use of ratios results in less than 10% of such outlier conclusions. We also determined that

  1. Symptomatic type 1 protein C deficiency caused by a de novo Ser270Leu mutation in the catalytic domain

    DEFF Research Database (Denmark)

    Lind, B; Koefoed, P; Thorsen, S

    2001-01-01

    the intracellular content of mutant and wild-type protein was similar. Northern blot analysis of total mRNA from transfected cells showed no reduction of the mutant protein C mRNA compared with wild-type protein C mRNA. Collectively, these results indicate that the Ser270Leu mutation in the affected family caused......Heterozygosity for a C8524T transition in the protein C gene converting Ser270(TCG) to Leu(TTG) in the protease domain was identified in a family with venous thrombosis. The mutation was associated with parallel reduction in plasma levels of protein C anticoagulant activity and protein C antigen......, which is consistent with a type 1 deficiency. Transient expression of mutant protein C cDNA in human kidney 293 cells and analysis of protein C antigen in culture media and cell lysates showed that the secretion of mutant protein compared with wild-type protein was reduced by at least 97% while...

  2. Alternative routes for highway shipments of radioactive materials and lessons learned from state designations

    International Nuclear Information System (INIS)

    1990-07-01

    Pursuant to the Hazardous Materials Transportation Act (HMTA), the Department of Transportation (DOT) has promulgated a comprehensive set of regulations regarding the highway transportation of high-level radioactive materials. These regulations, under docket numbers HM-164 and HM-164A, establish interstate highways as the preferred routes for the transportation of radioactive materials within and through the states. The regulations also provide a methodology by which a state may select altemative routes. First, the state must establish a ''state routing agency'', defined as an entity authorized to use the state legal process to impose routing requirements on carriers of radioactive material (49 CFR 171.8). Once identified, the state routing agency must select routes in accordance with DOTs Guidelines for Selecting Preferred Highway Routes for Large Quantity Shipments of Radioactive Materials or an equivalent routing analysis. Adjoining states and localities should be consulted on the impact of proposed alternative routes as a prerequisite of final route selection. Lastly, the states must provide written notice to DOT of any alternative route designation before the routes are deemed effective. The purpose of this report is to discuss the ''lessons learned'' by the five states within the southern region that have designated alternative or preferred routes under the regulations of the Department of Transportation (DOT) established for the transportation of radioactive materials. The document was prepared by reviewing applicable federal laws and regulations, examining state reports and documents and contacting state officials and routing agencies involved in making routing decisions. In undertaking this project, the Southern States Energy Board hopes to reveal the process used by states that have designated alternative routes and thereby share their experiences (i.e., lessons learned) with other southern states that have yet to make designations

  3. RIP Input Tables From Wapdeg For LA Design Selection: Enhanced Design Alternative IIIb

    International Nuclear Information System (INIS)

    K.G. Mon; K.G. Mast; J.H. Lee

    1999-01-01

    The purpose of this calculation is to document the Waste Package Degradation (WAPDEG) version 3.09 (CRWMS M and O 1998b. 'Software Routine Report for WAPDEG' (Version 3.09)) simulations used to analyze degradation and failure of 2-cm thick titanium grade 7 corrosion resistant material (CRM) drip shields as well as degradation and failure of the waste packages over which they are placed. The waste packages are composed of two corrosion resistant materials (CRM) barriers. The outer barrier is composed of 2 cm of Alloy 22 and the inner barrier is composed of 1.5 cm of titanium grade 7. The WAPDEG simulation results are post-processed into tables of drip shield/waste package degradation time histories suitable for use as input into the Integrated Probabilistic Simulator for Environmental Systems (RIP) version 5.19.01 (Golder Associates 1998) computer code. This calculation supports Performance Assessment analysis of the License Application Design Selection (LADS) Enhanced Design Alternative IIIb

  4. A novel monolithic LEU foil target based on a PVD manufacturing process for 99Mo production via fission.

    Science.gov (United States)

    Hollmer, Tobias; Petry, Winfried

    2016-12-01

    99 Mo is the most widely used radioactive isotope in nuclear medicine. Its main production route is the fission of uranium. A major challenge for a reliable supply is the conversion from highly enriched uranium (HEU) to low enriched uranium (LEU). A promising candidate to realize this conversion is the cylindrical LEU irradiation target. The target consists of a uranium foil encapsulated between two coaxial aluminum cladding cylinders. This target allows a separate processing of the irradiated uranium foil and the cladding when recovering the 99 Mo. Thereby, both the costs and the volume of highly radioactive liquid waste are significantly reduced compared to conventional targets. The presented manufacturing process is based on the direct coating of the uranium on the inside of the outer cladding cylinder. This process was realized by a cylindrical magnetron enhanced physical vapor deposition (PVD) technique. The method features a highly automated process, a good quality of the resulting uranium foils and a high material utilization. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Present status of the use of LEU in aqueous reactors to produce Mo-99

    International Nuclear Information System (INIS)

    Ball, Russell M.; Pavshook, V.A.; Khvostionov, V.Ye.

    1998-01-01

    An operating aqueous homogeneous reactor, the ARGUS at Kurchatov Institute, has been used to produce fission product molybdenum-99 (Mo-99), widely used in nuclear medicine to produce technetium-99m (Tc-99m). The Mo-99 has been extracted from the sulfate solution using an organic sorbent after operation at 1 kW/liter. after purification, the material has been assayed and the result is well within required specification of the USPharmacopaeia. Operation calculation are presented to show the sources and quantity of alpha activity when LEU is used. (author)

  6. Review of the TREAT Conversion Conceptual Design and Fuel Qualification Plan

    Energy Technology Data Exchange (ETDEWEB)

    Diamond, David

    2017-12-29

    The U.S. Department of Energy (DOE) is preparing to re establish the capability to conduct transient testing of nuclear fuels at the Idaho National Laboratory (INL) Transient Reactor Test (TREAT) facility. The original TREAT core went critical in February 1959 and operated for more than 6,000 reactor startups before plant operations were suspended in 1994. DOE is now planning to restart the reactor using the plant's original high-enriched uranium (HEU) fuel. At the same time, the National Nuclear Security Administration (NNSA) Office of Material Management and Minimization Reactor Conversion Program is supporting analyses and fuel fabrication studies that will allow for reactor conversion to low-enriched uranium (LEU) fuel (i.e., fuel with less than 20% by weight 235U content) after plant restart. The TREAT Conversion Program's objectives are to perform the design work necessary to generate an LEU replacement core, to restore the capability to fabricate TREAT fuel element assemblies, and to implement the physical and operational changes required to convert the TREAT facility to use LEU fuel.

  7. Poliovirus Polymerase Leu420 Facilitates RNA Recombination and Ribavirin Resistance

    Science.gov (United States)

    Kempf, Brian J.; Peersen, Olve B.

    2016-01-01

    ABSTRACT RNA recombination is important in the formation of picornavirus species groups and the ongoing evolution of viruses within species groups. In this study, we examined the structure and function of poliovirus polymerase, 3Dpol, as it relates to RNA recombination. Recombination occurs when nascent RNA products exchange one viral RNA template for another during RNA replication. Because recombination is a natural aspect of picornavirus replication, we hypothesized that some features of 3Dpol may exist, in part, to facilitate RNA recombination. Furthermore, we reasoned that alanine substitution mutations that disrupt 3Dpol-RNA interactions within the polymerase elongation complex might increase and/or decrease the magnitudes of recombination. We found that an L420A mutation in 3Dpol decreased the frequency of RNA recombination, whereas alanine substitutions at other sites in 3Dpol increased the frequency of recombination. The 3Dpol Leu420 side chain interacts with a ribose in the nascent RNA product 3 nucleotides from the active site of the polymerase. Notably, the L420A mutation that reduced recombination also rendered the virus more susceptible to inhibition by ribavirin, coincident with the accumulation of ribavirin-induced G→A and C→U mutations in viral RNA. We conclude that 3Dpol Leu420 is critically important for RNA recombination and that RNA recombination contributes to ribavirin resistance. IMPORTANCE Recombination contributes to the formation of picornavirus species groups and the emergence of circulating vaccine-derived polioviruses (cVDPVs). The recombinant viruses that arise in nature are occasionally more fit than either parental strain, especially when the two partners in recombination are closely related, i.e., members of characteristic species groups, such as enterovirus species groups A to H or rhinovirus species groups A to C. Our study shows that RNA recombination requires conserved features of the viral polymerase. Furthermore, a

  8. A Ser29Leu substitution in the cytosine deaminase Fca1p is responsible for clade-specific flucytosine resistance in Candida dubliniensis.

    LENUS (Irish Health Repository)

    McManus, Brenda A

    2009-11-01

    The population structure of the opportunistic yeast pathogen Candida dubliniensis is composed of three main multilocus sequence typing clades (clades C1 to C3), and clade C3 predominantly consists of isolates from the Middle East that exhibit high-level resistance (MIC(50) > or = 128 microg\\/ml) to the fungicidal agent flucytosine (5FC). The close relative of C. dubliniensis, C. albicans, also exhibits clade-specific resistance to 5FC, and resistance is most commonly mediated by an Arg101Cys substitution in the FUR1 gene encoding uracil phosphoribosyltransferase. Broth microdilution assays with fluorouracil (5FU), the toxic deaminated form of 5FC, showed that both 5FC-resistant and 5FC-susceptible C. dubliniensis isolates exhibited similar 5FU MICs, suggesting that the C. dubliniensis cytosine deaminase (Fca1p) encoded by C. dubliniensis FCA1 (CdFCA1) may play a role in mediating C. dubliniensis clade-specific 5FC resistance. Amino acid sequence analysis of the CdFCA1 open reading frame (ORF) identified a homozygous Ser29Leu substitution in all 12 5FC-resistant isolates investigated which was not present in any of the 9 5FC-susceptible isolates examined. The tetracycline-inducible expression of the CdFCA1 ORF from a 5FC-susceptible C. dubliniensis isolate in two separate 5FC-resistant clade C3 isolates restored susceptibility to 5FC, demonstrating that the Ser29Leu substitution was responsible for the clade-specific 5FC resistance and that the 5FC resistance encoded by FCA1 genes with the Ser29Leu transition is recessive. Quantitative real-time PCR analysis showed no significant difference in CdFCA1 expression between 5FC-susceptible and 5FC-resistant isolates in either the presence or the absence of subinhibitory concentrations of 5FC, suggesting that the Ser29Leu substitution in the CdFCA1 ORF is the sole cause of 5FC resistance in clade C3 C. dubliniensis isolates.

  9. Alternative Shear Panel Configurations for Light Wood Construction. Development, Seismic Performance, and Design Guidance

    Science.gov (United States)

    Wilcoski, James; Fischer, Chad; Allison, Tim; Malach, Kelly Jo

    2002-04-01

    Shear panels are used in light wood construction to resist lateral loads resulting from earthquakes or strong winds. These panels are typically made of wooden sheathing nailed to building frame members, but this standard panel design interferes with the installation of sheet insulation. A non-insulated shear panel conducts heat between the building interior and exterior wasting considerable amounts of energy. Several alternative shear panel designs were developed to avoid this insulation-mounting problem and sample panels were tested according to standard cyclic test protocols. One of the alternative designs consisted of diagonal steel straps nailed directly to the structural framing. Several others consisted of sheathing nailed to 2 x 4 framing then set into a larger 2 x 6 structural frame in such a way that no sheathing protruded beyond the edge of the 2 x 6 members. Also samples of industry-standard shear panels were constructed and tested in order to establish a performance baseline. Analytical models were developed to size test panels and predict panel behavior. A procedure was developed for establishing design capacities based on both test data and established baseline panel design capacity. The behavior of each panel configuration is documented and recommended design capacities are presented.

  10. DDE-MURR Status Report of Conceptual Design Activities

    Energy Technology Data Exchange (ETDEWEB)

    N.E. Woolstenhulme; R.B. Nielson; M.H. Sprenger; G.K. Housley

    2013-09-01

    The Design Demonstration Experiment for the University of Missouri Research Reactor (DDE-MURR) is intended to facilitate Low Enriched Uranium (LEU) conversion of the MURR by demonstrating the performance and fabrication of the LEU fuel element design through an irradiation test in a 200mm channel at the Belgium Reactor 2 (BR2). Revision 0 of this report was prepared at the end of government fiscal year 2012 when most of the resources for furthering DDE design work were expected to be postponed. Hence, the conceptual design efforts were summarized to provide the status of key objectives, notable results, and provisions for future design work. Revision 1 of this report was prepared at the end of fiscal year 2013 in order to include results from a neutronic study performed by BR2, to incorporate further details that had been achieved in the engineering sketches of the irradiation devices, and to provide an update of the DDE-MURR campaign in relation to program objectives and opportunities for its eventual irradiation. These updates were purposed to bring the DDE-MURR conceptual design to level of maturity similar to that of the other two DDE efforts (DDE-MITR and DDE-NBSR). This report demonstrates that the DDE-MURR design effort is well on the path to producing a suitable irradiation experiment, but also puts forth several recommendations in order to facilitate success of the irradiation campaign.

  11. Double heterozygous mutations Gln100Leu and His348Gln of the F7 gene in a patient with factor VII deficiency.

    Science.gov (United States)

    Li, Min; Zheng, Fangxiu; Jin, Yanhui; Wang, Mingshan; Zhu, Liqing; Yang, Lihong

    2013-03-01

    A 25-year-old Chinese woman who had a history of easy bruising was admitted to hospital due to uncontrolled epistaxis. She showed factor VII activity level of 2% and factor VII antigen level of 4% of the normal value. We detected a novel missense mutation g.8355 A>T (p.Gln100Leu) in the second epidermal growth factor-like (EGF) domain and a g.11482 T>G (p.His348Gln) in the catalytic domain. Although the Gln100 residue is close to the junction of EGF-2 domain with the serine protease domain, we infer that the substitution of polar negatively charged Gln residue at the position 100 with introduction of nonpolar Leu residue may be likely to perturb proper folding, resulting in decreasing factor VII activity.

  12. IRT‑Sofia, HEU to LEU conversion: regulatory approval tasks solution overview

    International Nuclear Information System (INIS)

    Mitev, Mladen; Belousov, Sergey; Dimitrov, Dobromir

    2014-01-01

    The HEU to LEU conversion of the IRT–Sofia research reactor of the Institute for Nuclear Research and Nuclear Energy of the Bulgarian Academy of Sciences was jointly studied with the Argonne National Laboratory as a part of the RERTR Programme. The main purpose of the collaboration consisted in accomplishment of safety analyses and preparation of documents used for regulatory approval tasks solution. The main steps and results which are fundamental for the preparation of IRT–Sofia Safety Analyses Report including Operating Limits and Conditions are presented in this paper. The documents prepared by INRNE in accordance with the European nuclear safety requirements and IAEA recommendations were submitted for approval to the Bulgarian Nuclear Regulatory Agency at the end of 2010. Key words: research reactor, safety analyses report, Nuclear Regulatory Agency

  13. Lithography alternatives meet design style reality: How do they "line" up?

    Science.gov (United States)

    Smayling, Michael C.

    2016-03-01

    Optical lithography resolution scaling has stalled, giving innovative alternatives a window of opportunity. One important factor that impacts these lithographic approaches is the transition in design style from 2D to 1D for advanced CMOS logic. Just as the transition from 3D circuits to 2D fabrication 50 years ago created an opportunity for a new breed of electronics companies, the transition today presents exciting and challenging time for lithographers. Today, we are looking at a range of non-optical lithography processes. Those considered here can be broadly categorized: self-aligned lithography, self-assembled lithography, deposition lithography, nano-imprint lithography, pixelated e-beam lithography, shot-based e-beam lithography .Do any of these alternatives benefit from or take advantage of 1D layout? Yes, for example SAPD + CL (Self Aligned Pitch Division combined with Complementary Lithography). This is a widely adopted process for CMOS nodes at 22nm and below. Can there be additional design / process co-optimization? In spite of the simple-looking nature of 1D layout, the placement of "cut" in the lines and "holes" for interlayer connections can be tuned for a given process capability. Examples of such optimization have been presented at this conference, typically showing a reduction of at least one in the number of cut or hole patterns needed.[1,2] Can any of the alternatives complement each other or optical lithography? Yes.[3] For example, DSA (Directed Self Assembly) combines optical lithography with self-assembly. CEBL (Complementary e-Beam Lithography) combines optical lithography with SAPD for lines with shot-based e-beam lithography for cuts and holes. Does one (shrinking) size fit all? No, that's why we have many alternatives. For example NIL (Nano-imprint Lithography) has been introduced for NAND Flash patterning where the (trending lower) defectivity is acceptable for the product. Deposition lithography has been introduced in 3D NAND Flash to

  14. Refuge alternatives relief valve testing and design with updated test stand.

    Science.gov (United States)

    Lutz, T J; Bissert, P T; Homce, G T; Yonkey, J A

    2018-03-01

    Underground refuge alternatives require an air source to supply breathable air to the occupants. This requires pressure relief valves to prevent unsafe pressures from building up within the refuge alternative. The U.S. Mine Safety and Health Administration (MSHA) mandates that pressure relief valves prevent pressure from exceeding 1.25 kPa (0.18 psi), or as specified by the manufacturer, above mine atmospheric pressure when a fan or compressor is used for the air supply. The U.S. National Institute for Occupational Safety and Health (NIOSH) tested a variety of pressure relief valves using an instrumented test fixture consisting of data acquisition equipment, a centrifugal blower, ductwork and various sensors to determine if the subject pressure relief valves meet the MSHA requirement. Relief pressures and flow characteristics, including opening pressure and flow rate, were measured for five different pressure relief valves under a variety of conditions. The subject pressure relief valves included two off-the-shelf modified check valves, two check valves used in MSHA-approved built-in-place refuge alternatives, and a commercially available valve that was designed for a steel refuge alternative and is currently being used in some built-in-place refuge alternatives. The test results showed relief pressures ranging from 0.20 to 1.53 kPa (0.03 to 0.22 psi) and flow rates up to 19.3 m 3 /min (683 scfm). As tested, some of the pressure relief valves did not meet the 1.25 kPa (0.18 psi) relief specification.

  15. THE ALTERNATIVE CORELDRAWINGS AN IDEAL SOLUTION FOR DESIGNERS, IN EMBROIDERY

    Directory of Open Access Journals (Sweden)

    Marin Florea

    2013-01-01

    Full Text Available The machine beaded appearance coincides with the first sewing machine mechanical America sold out in the best-known company of sewing machines in the world: The singer Company in the year 1863. The first machine beaded computer-assisted has been constructed by Wilcom in 1980. After 1990, developments in microprocessors allowed that all types of mechanical machines beaded to turn to digital machines beaded. These machines use digital designs. Developments in digital beaded machines allowed customization industrial products made in series. The raw material that is most important is a digital drawing. List of most important brands is high. Taking into account the number of large editors for embroidery it is almost impossible for a designer to know CAD design for all text editors. This is a problem both for designers but also for producers. A practical solution for designers is CorelDrawings what offers the convenience of design specific vector graphic-designers. Automatic conversion of the vector, the library with textures, simulate embroideries and save specific formats great brands make CorelDrawings a practical alternative. Designer can focus on specific problems without using a large number of editors for each brand. We approached a drawing of the logo to demonstrate practical capabilities. Drawing digital was saved in a format and open industrial professional editor Wilcom Designer. Export to grid format may allow analysis and discussions with the customer before it has been transposed into production.

  16. Evaluation of alternative public transportation systems in Izmit urban transportation via axiomatic design method

    Directory of Open Access Journals (Sweden)

    Gülşen AKMAN

    2016-02-01

    Full Text Available In the world and in our country, most of urban transportation is performed by public transportation. Public transportation is a system which provides transportation easiness and opportunity to people, not to vehicles. Therefore, giving priority to public transportation system is necessary in organizing urban transportation. In this study, in order to reduce traffic intensity and to facilitate passenger transportation in Izmit urban transportation, It is tried to determine appropriate public transportation system. For this, firstly, alternatives which could be used for public transportation were determined. These alternatives are metro, metrobus, tram, light rail system and monorail. Afterwards, the variables affecting decision making about public transportation were determined. These variables are cost, transportation line features, vehicle characteristics, sensitivity to environment and customer satisfaction. Lastly, most appropriate public transportation system is proposed by using the axiomatic design method. As a result, light trail system and metrobus are determined as the most appropriate alternatives for Izmit public transportation system.Keywords: Urban transportation, Multi criteria decision making, Axiomatic design

  17. An alternate end design for SSC dipoles

    International Nuclear Information System (INIS)

    Peters, C.; Caspi, S.; Taylor, C.

    1989-02-01

    Experience in the SSC dipole program has shown that fabrication of cylindrical coil ends is difficult. Cable stiffness requires large forces to maintain the proper position of the conductors in the end during winding. After winding, the coil ends remain distorted nd significant motion of the need conductors is required to force the coil end into the molding cavity. Local mechanical stresses are high during this process and extra pieces of insulation are required to prevent turn-to-turn shorts from developing during the winding and molding steps. Prior to assembly the coil end is compressed in a mold cavity and injected with a filler material to correct surface irregularities and fill voids in the end. LBL has developed an alternate design which permits the conductors to be wound over the end using minimal force and technician coerosion. The conductors are placed on a conical surface where the largest diameter over the outer layer conductors is 10 cm. No coil end spaces or insulation pieces between turns are required. The conductor geometry was analytically optimized to meet SSC multipole requirements for the ends. The first 1-m dipole utilizing this end geometry has been constructed and successfully tested. Design and construction data are presented. Also model test results, including training and multipole measurements of the end are given. 1 ref., 12 figs., 3 tabs

  18. YibK is the 2'-O-methyltransferase TrmL that modifies the wobble nucleotide in Escherichia coli tRNA(Leu) isoacceptors

    DEFF Research Database (Denmark)

    Benítez-Páez, Alfonso; Villarroya, Magda; Douthwaite, Stephen Roger

    2010-01-01

    to uncover candidate E. coli genes for the missing enzyme(s). Transfer RNAs from null mutants for candidate genes were analyzed by mass spectrometry and revealed that inactivation of yibK leads to loss of 2'-O-methylation at position 34 in both tRNA(Leu)(CmAA) and tRNA(Leu)(cmnm5UmAA). Loss of Yib...... of the wobble nucleotide; YibK recognition of this target requires a pyridine at position 34 and N⁶-(isopentenyl)-2-methylthioadenosine at position 37. YibK is one of the last remaining E. coli tRNA modification enzymes to be identified and is now renamed TrmL.......Transfer RNAs are the most densely modified nucleic acid molecules in living cells. In Escherichia coli, more than 30 nucleoside modifications have been characterized, ranging from methylations and pseudouridylations to more complex additions that require multiple enzymatic steps. Most...

  19. Long-term strategies for flood risk management: scenario definition and strategic alternative design

    NARCIS (Netherlands)

    Bruijn, de K.; Klijn, F.; McGahey, C.; Mens, M.; Wolfert, H.P.

    2008-01-01

    This report reviews some mainstream existing methods of scenario development and use, as well as experiences with the design and assessment of strategic alternatives for flood risk management. Next, a procedure and methods are proposed and discussed. Thirdly, the procedure and methods are tried on

  20. Data Compilation for AGR-1 Baseline Coated Particle Composite LEU01-46T

    International Nuclear Information System (INIS)

    Hunn, John D.; Lowden, Richard Andrew

    2006-01-01

    This document is a compilation of characterization data for the AGR-1 baseline coated particle composite LEU01-46T, a composite of four batches of TRISO-coated 350 (micro)m 19.7% low enrichment uranium oxide/uranium carbide kernels (LEUCO). The AGR-1 TRISO-coated particles consist of a spherical kernel coated with a ∼ 50% dense carbon buffer layer (100 (micro)m nominal thickness) followed by a dense inner pyrocarbonlayer (40 (micro)m nominal thickness) followed by a SiC layer (35 (micro)m nominal thickness) followed by another dense outer pyrocarbon layer (40 (micro)m nominal thickness). The coated particles, were produced by ORNL for the Advanced Gas Reactor Fuel Development and Qualification (AGR) program to be put into compacts for insertion in the first irradiation test capsule, AGR-1. The kernels were obtained from BWXT and identified as composite (G73D-20-69302). The BWXT kernel lot G73D-20-69302 was riffled into sublots for characterization and coating by ORNL and identified as LEU01-?? (where ?? is a series of integers beginning with 01). Additional particle batches were coated with only buffer or buffer plus inner pyrocarbon (IPyC) layers using similar process conditions as used for the full TRISO batches comprising the LEU01-46T composite. These batches were fabricated in order to qualify that the process conditions used for buffer and IPyC would produce acceptable densities, as described in sections 8 and 9. These qualifying batches used 350 (micro)m natural uranium oxide/uranium carbide kernels (NUCO). The kernels were obtained from BWXT and identified as composite G73B-NU-69300. The use of NUCO surrogate kernels is not expected to significantly effect the densities of the buffer and IPyC coatings. Confirmatory batches using LEUCO kernels from G73D-20-69302 were coated and characterized to verify this assumption. The AGR-1 Fuel Product Specification and Characterization Guidance (INL EDF-4380, Rev. 6) provides the requirements necessary for acceptance

  1. Incorporating alternative design clinical trials in network meta-analyses

    Directory of Open Access Journals (Sweden)

    Thorlund K

    2014-12-01

    Full Text Available Kristian Thorlund,1–3 Eric Druyts,1,4 Kabirraaj Toor,1,5 Jeroen P Jansen,1,6 Edward J Mills1,3 1Redwood Outcomes, Vancouver, BC, 2Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, ON, Canada; 3Stanford Prevention Research Center, Stanford University, Stanford, CA, USA; 4Department of Medicine, Faculty of Medicine, 5School of Population and Public Health, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada; 6Department of Public Health and Community Medicine, Tufts University, Boston, MA, USA Introduction: Network meta-analysis (NMA is an extension of conventional pairwise meta-analysis that allows for simultaneous comparison of multiple interventions. Well-established drug class efficacies have become commonplace in many disease areas. Thus, for reasons of ethics and equipoise, it is not practical to randomize patients to placebo or older drug classes. Unique randomized clinical trial designs are an attempt to navigate these obstacles. These alternative designs, however, pose challenges when attempting to incorporate data into NMAs. Using ulcerative colitis as an example, we illustrate an example of a method where data provided by these trials are used to populate treatment networks. Methods: We present the methods used to convert data from the PURSUIT trial into a typical parallel design for inclusion in our NMA. Data were required for three arms: golimumab 100 mg; golimumab 50 mg; and placebo. Golimumab 100 mg induction data were available; however, data regarding those individuals who were nonresponders at induction and those who were responders at maintenance were not reported, and as such, had to be imputed using data from the rerandomization phase. Golimumab 50 mg data regarding responses at week 6 were not available. Existing relationships between the available components were used to impute the expected proportions in this missing subpopulation. Data for placebo maintenance

  2. Nuclear and radiological safety in the substitution process of the fuel HEU to LEU 30/20 in the Reactor TRIGA Mark III of the ININ

    International Nuclear Information System (INIS)

    Hernandez G, J.

    2012-10-01

    Inside the safety initiative in the international ambit, with the purpose of reducing the risks associated with the use of high enrichment nuclear fuels (HEU) for different proposes to the peaceful uses of the nuclear energy, Mexico contributes by means of the substitution of the high enrichment fuel HEU for low enrichment fuel LEU 30/20 in the TRIGA Mark III Reactor, belonging to Instituto Nacional de Investigaciones Nucleares (ININ). The conversion process was carried out by means of the following activities: analysis of the proposed core, reception and inspection of the fuel LEU 30/20, the discharge of the fuels of the mixed reactor core, shipment of the fuels HEU fresh and irradiated to the origin country, reload activities with the fuels LEU 30/20 and parameters measurement of the core operation. In order to maintaining the personnel's integrity and infrastructure associated to the Reactor, during the whole process the measurements of nuclear and radiological safety were controlled to detail, in execution with the license requirements of the installation. This work describes the covering activities and radiological inspections more relevant, as well as the measurements of radiological control implemented with base in the estimate of the equivalent dose of the substitution process. (Author)

  3. Irradiation Experiment Conceptual Design Parameters for NBSR Fuel Conversion

    Energy Technology Data Exchange (ETDEWEB)

    Brown, N. R. [Brookhaven National Lab. (BNL), Upton, NY (United States). Nuclear Science and Technology Dept.; Brown, N. R. [Brookhaven National Lab. (BNL), Upton, NY (United States). Nuclear Science and Technology Dept.; Baek, J. S [Brookhaven National Lab. (BNL), Upton, NY (United States). Nuclear Science and Technology Dept.; Hanson, A. L. [Brookhaven National Lab. (BNL), Upton, NY (United States). Nuclear Science and Technology Dept.; Cuadra, A. [Brookhaven National Lab. (BNL), Upton, NY (United States). Nuclear Science and Technology Dept.; Cheng, L. Y. [Brookhaven National Lab. (BNL), Upton, NY (United States). Nuclear Science and Technology Dept.; Diamond, D. J. [Brookhaven National Lab. (BNL), Upton, NY (United States). Nuclear Science and Technology Dept.

    2014-04-30

    It has been proposed to convert the National Institute of Standards and Technology (NIST) research reactor, known as the NBSR, from high-enriched uranium (HEU) fuel to low-Enriched uranium (LEU) fuel. The motivation to convert the NBSR to LEU fuel is to reduce the risk of proliferation of special nuclear material. This report is a compilation of relevant information from recent studies related to the proposed conversion using a metal alloy of LEU with 10 w/o molybdenum. The objective is to inform the design of the mini-plate and full-size-Plate irradiation experiments that are being planned. This report provides relevant dimensions of the fuel elements, and the following parameters at steady state: average and maximum fission rate density and fission density, fuel temperature distribution for the plate with maximum local temperature, and two-dimensional heat flux profiles of fuel plates with high power densities. The latter profiles are given for plates in both the inner and outer core zones and for cores with both fresh and depleted shim arms (reactivity control devices). A summary of the methodology to obtain these results is presented. Fuel element tolerance assumptions and hot channel factors used in the safety analysis are also given.

  4. Crafting decision options and alternatives for designing cultural observation system using general morphological modelling

    Directory of Open Access Journals (Sweden)

    Jaber Moghaddampour

    2018-09-01

    Full Text Available According to connoisseurs, cultural system is encountering a fully new space in future decades and cultural indicators will be exposed by some dangers; for the same reason, cultural observation activities in management dialogue of Iran are emphasized; the concept of “observation” in Iran is facing with challenges including being far from the concepts of futures studies and the focus on “cultural indicators monitoring” while cultural engineering needs foresight and identification of affecting progressive and deterring factors on the culture. The present study aims at providing alternatives to design an observation system by considering the monitoring and scanning simultaneously to bring out strategic and futurist vision for cultural organizations. To this end, the solution space and morphological field of observation (parameters and values by using MA/Carma Viewer software package is designed based on the literature review and forming a five-member expert group and specialized conversations. Upon Internal Consistency Assessment of parameters and by considering some values as drivers, Parameters Activity Check was conducted to study the reactions by other parameters and values. After sense-making and proper understanding of the model behavior, an Inference and “What-If” model were devised; some configurations were studied and provided in order to aware a part of proper alternatives for designing a cultural observation system (two scenarios. Scenario selection is different due to contingencies and conditions of executing the process as well as the users’ needs and goals in cultural observation system and cultural organizations can make decisions and design detailed observation systems by using morphological models, solution space and alternatives provided in the present study and depended on their goals and needs.

  5. RIP Input Tables from WAPDEG for LA Design Selection: Enhanced Design Alternative II-3

    International Nuclear Information System (INIS)

    A.M. Monib

    1999-01-01

    The purpose of this calculation is to document (1) the Waste Package Degradation (WAPDEG) version 3.09 (CRWMS M and O 1998b. ''Software Routine Report for WAPDEG'' (Version 3.09)) simulations used to analyze degradation and failure of 2-cm thick titanium grade 7 corrosion resistant material (CRM) drip shields (that are placed over waste packages composed of a 2-cm thick Alloy 22 corrosion resistant material (CRM) as the outer barrier and an unspecified material to provide structural support as the inner barrier) as well as degradation and failure of the waste packages themselves, and (2) post-processing of these results into tables of drip shield/waste package degradation time histories suitable for use as input into the Integrated Probabilistic Simulator for Environmental Systems (RIP) version 5.19.01 (Golder Associates 1998) computer code. This calculation supports Performance Assessment analysis of the License Application Design Selection (LADS) Enhanced Design Alternative (EDA) II-3. The aging period in the EDA II design (CRWMS M and O 1999f. ''Design Input Request for LADS Phase II EDA Evaluations'', Item 1 Row 9 Column 3) was replaced in the case of EDA II-3 with 25 years preclosure ventilation, leading to a total of 50 years preclosure ventilation. The waste packages are line loaded in the repository and no backfill is used

  6. Advanced Multiphysics Thermal-Hydraulics Models for the High Flux Isotope Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Jain, Prashant K [ORNL; Freels, James D [ORNL

    2015-01-01

    Engineering design studies to determine the feasibility of converting the High Flux Isotope Reactor (HFIR) from using highly enriched uranium (HEU) to low-enriched uranium (LEU) fuel are ongoing at Oak Ridge National Laboratory (ORNL). This work is part of an effort sponsored by the US Department of Energy (DOE) Reactor Conversion Program. HFIR is a very high flux pressurized light-water-cooled and moderated flux-trap type research reactor. HFIR s current missions are to support neutron scattering experiments, isotope production, and materials irradiation, including neutron activation analysis. Advanced three-dimensional multiphysics models of HFIR fuel were developed in COMSOL software for safety basis (worst case) operating conditions. Several types of physics including multilayer heat conduction, conjugate heat transfer, turbulent flows (RANS model) and structural mechanics were combined and solved for HFIR s inner and outer fuel elements. Alternate design features of the new LEU fuel were evaluated using these multiphysics models. This work led to a new, preliminary reference LEU design that combines a permanent absorber in the lower unfueled region of all of the fuel plates, a burnable absorber in the inner element side plates, and a relocated and reshaped (but still radially contoured) fuel zone. Preliminary results of estimated thermal safety margins are presented. Fuel design studies and model enhancement continue.

  7. Lawrence Livermore National Laboratory Decontamination and Waste Treatment Facility: Documentation of impact analysis for design alternatives presented in the Draft Environmental Impact Statement

    International Nuclear Information System (INIS)

    1988-05-01

    Lawrence Livermore National Laboratory (LLNL) is proposing to construct and operate a new Decontamination and Waste Treatment Facility (DWTF). The proposed DWTF would replace the existing Hazardous Waste Management (HWM) facilities at LLNL. The US Department of Energy (DOE) is preparing a Draft Environmental Impact Statement (DEIS) to assess the environmental consequences of the proposed DWTF and its alternatives. This report presents the assumptions, methodologies, and analyses used to estimate the waste flows, air emissions, ambient air quality impacts, and public health risks that are presented in the DEIS. Two DWTF design alternatives (Level I and Level II) have been designated as reasonable design alternatives considering available technologies, environmental regulations, and current and future LLNL waste generation. Both design alternatives would include new, separate radioactive and nonradioactive liquid waste treatment systems, a solidification unit, a new decontamination facility, storage and treatment facilities for reactive materials, a radioactive waste storage area, receiving and classification areas, and a uranium burn pan. The Level I design alternative would include a controlled-air incinerator system, while the Level II design alternative would include a rotary kiln incinerator system. 43 refs., 4 figs., 24 tabs

  8. Fuel element burnup measurements for the equilibrium LEU silicide RSG GAS (MPR-30) core under a new fuel management strategy

    International Nuclear Information System (INIS)

    Pinem, Surian; Liem, Peng Hong; Sembiring, Tagor Malem; Surbakti, Tukiran

    2016-01-01

    Highlights: • Burnup measurement of fuel elements comprising the new equilibrium LEU silicide core of RSG GAS. • The burnup measurement method is based on a linear relationship between reactivity and burnup. • Burnup verification was conducted using an in-house, in-core fuel management code BATAN-FUEL. • A good agreement between the measured and calculated burnup was confirmed. • The new fuel management strategy was confirmed and validated. - Abstract: After the equilibrium LEU silicide core of RSG GAS was achieved, there was a strong need to validate the new fuel management strategy by measuring burnup of fuel elements comprising the core. Since the regulatory body had a great concern on the safety limit of the silicide fuel element burnup, amongst the 35 burnt fuel elements we selected 22 fuel elements with high burnup classes i.e. from 20 to 53% loss of U-235 (declared values) for the present measurements. The burnup measurement method was based on a linear relationship between reactivity and burnup where the measurements were conducted under subcritical conditions using two fission counters of the reactor startup channel. The measurement results were compared with the declared burnup evaluated by an in-house in-core fuel management code, BATAN-FUEL. A good agreement between the measured burnup values and the calculated ones was found within 8% uncertainties. Possible major sources of differences were identified, i.e. large statistical errors (i.e. low fission counters’ count rates), variation of initial U-235 loading per fuel element and accuracy of control rod indicators. The measured burnup of the 22 fuel elements provided the confirmation of the core burnup distribution planned for the equilibrium LEU silicide core under the new fuel management strategy.

  9. Core physics analysis in support of the FNR HEU-LEU demonstration experiment

    Energy Technology Data Exchange (ETDEWEB)

    Losey, David C; Brown, Forrest B; Martin, William R; Lee, John C [Department of Nuclear Engineering, University of Michigan (United States)

    1983-08-01

    A core neutronics analysis has been undertaken to assess the impact of low-enrichment fuel on the performance and utilization of the FNR As part of this analytic effort a computer code system has been assembled which will be of general use in analyzing research reactors with MTR-type fuel. The code system has been extensively tested and verified in calculations for the present high enrichment core. The analysis presented here compares the high-and-low enrichment fuels in batch and equilibrium core configurations which model the actual FNR operating conditions. The two fuels are compared for cycle length, fuel burnup, and flux and power distributions, as well as for the reactivity effects which are important in assessing the impact of LEU fuel on reactor shutdown margin. (author)

  10. Core physics analysis in support of the FNR HEU-LEU demonstration experiment

    International Nuclear Information System (INIS)

    Losey, David C.; Brown, Forrest B.; Martin, William R.; Lee, John C.

    1983-01-01

    A core neutronics analysis has been undertaken to assess the impact of low-enrichment fuel on the performance and utilization of the FNR As part of this analytic effort a computer code system has been assembled which will be of general use in analyzing research reactors with MTR-type fuel. The code system has been extensively tested and verified in calculations for the present high enrichment core. The analysis presented here compares the high-and-low enrichment fuels in batch and equilibrium core configurations which model the actual FNR operating conditions. The two fuels are compared for cycle length, fuel burnup, and flux and power distributions, as well as for the reactivity effects which are important in assessing the impact of LEU fuel on reactor shutdown margin. (author)

  11. Comparison of MCNP and WIMS-AECL/RFSP calculations against critical heavy water experiments in ZED-2 with CANFLEX-LVRF and CANFLEX-LEU fuels

    International Nuclear Information System (INIS)

    Bromley, B. P.; Watts, D. G.; Pencer, J.; Zeller, M.; Dweiri, Y.

    2009-01-01

    This paper summarizes calculations of MCNP5 and WIMS-AECL/RFSP compared against measurements in coolant void substitution experiments in the ZED-2 critical facility with CANFLEX R-LEU/RU (Low Enriched Uranium, Recovered Uranium) reference fuels and CANFLEX-LVRF (Low Void Reactivity Fuel) test fuel, and H 2 O/air coolants. Both codes are tested for the prediction of the change in reactivity with complete voiding of all fuel channels, and that for a checkerboard voiding pattern. Understanding these phenomena is important for the ACR-1000 R reactor. Comparisons are also made for the prediction of the axial and radial neutron flux distributions, as measured by copper foil activation. The experimental data for these comparisons were obtained from critical mixed lattice / substitution experiments in AECL's ZED-2 critical facility using CANFLEX-LEU/RU and CANFLEX-LVRF fuel in a 24-cm square lattice pitch at 25 degrees C. Substitution analyses were performed to isolate the properties (buckling, bare critical lattice dimensions) of the CANFLEX-LVRF fuel. This data was then used to further test the lattice physics codes. These comparisons establish biases/uncertainties and errors in the calculation of k eff , coolant void reactivity, checkerboard coolant void reactivity, and flux distributions. Results show small to modest biases in void reactivity and very good agreement for flux distributions. The importance of boundary conditions and the modeling of un-moderated fuel in the critical experiments are demonstrated. This comparison study provides data that supports code validation and gives good confidence in the reactor physics tools used in the design and safety analysis of the ACR-1000 reactor. (authors)

  12. An Evaluation of Alternative Designs for a Grid Information Service

    Science.gov (United States)

    Smith, Warren; Waheed, Abdul; Meyers, David; Yan, Jerry; Kwak, Dochan (Technical Monitor)

    2001-01-01

    The Globus information service wasn't working well. There were many updates of data from Globus daemons which saturated the single server and users couldn't retrieve information. We created a second server for NASA and Alliance. Things were great on that server, but a bit slow on the other server. We needed to know exactly how the information service was being used. What were the best servers and configurations? This viewgraph presentation gives an overview of the evaluation of alternative designs for a Grid Information Service. Details are given on the workload characterization, methodology used, and the performance evaluation.

  13. Neutronic feasibility studies using U-Mo dispersion fuel (9 Wt % Mo, 5.0 gU/cm3) for LEU conversion of the MARIA (Poland), IR-8 (Russia), and WWR-SM (Uzbekistan) research reactors

    International Nuclear Information System (INIS)

    Bretscher, M.M.; Deen, J.R.; Hanan, N.A.; Matos, E.

    2000-01-01

    U-Mo alloys dispersed in an Al matrix offer the potential for high-density uranium fuels needed for the LEU conversion of many research reactors. On-going fuel qualification tests by the US RERTR Program show good irradiation properties of U-Mo alloy dispersion fuel containing 7-10 weight percent molybdenum. For the neutronic studies in this paper the alloy was assumed to contain 9 wt % Mo (U-9Mo) with a uranium density in the fuel meat of 5.00 gU/cm 3 which corresponds to 32.5 volume % U-9Mo. Fuels containing U-9Mo have been used in Russian reactors since the 1950's. For the three research reactors analyzed here, LEU fuel element thicknesses are the same as those for the Russian-fabricated HEU reference fuel elements. Relative to the reference fuels containing 80-90% enriched uranium, LEU U-9Mo Al-dispersion fuel with 5.00 gU/cm 3 doubles the cycle length of the MARIA reactor and increases the IR-8 cycle length by about 11%. For the WWR-SM reactor, the cycle length, and thus the number of fuel assemblies used per year, is nearly unchanged. To match the cycle length of the 36% enriched fuel currently used in the WWR-SM reactor will require a uranium density in the LEU U-9Mo Al-dispersion fuel of about 5.4 gU/cm 3 . The 5.00 gU/cm 3 LEU fuel causes thermal neutron fluxes in water holes near the edge of the core to decrease by (6-8)% for all three reactors. (author)

  14. Supplemental Thermal-Hydraulic Transient Analyses of BR2 in Support of Conversion to LEU Fuel

    Energy Technology Data Exchange (ETDEWEB)

    Licht, J. [Argonne National Lab. (ANL), Argonne, IL (United States); Dionne, B. [Argonne National Lab. (ANL), Argonne, IL (United States); Sikik, E. [Belgian Nuclear Research Center (SCK-CEN), Mol (Belgium); Van den Branden, G. [Belgian Nuclear Research Center (SCK-CEN), Mol (Belgium); Koonen, E. [Belgian Nuclear Research Center (SCK-CEN), Mol (Belgium)

    2016-01-01

    Belgian Reactor 2 (BR2) is a research and test reactor located in Mol, Belgium and is primarily used for radioisotope production and materials testing. The Materials Management and Minimization (M3) Reactor Conversion Program of the National Nuclear Security Administration (NNSA) is supporting the conversion of the BR2 reactor from Highly Enriched Uranium (HEU) fuel to Low Enriched Uranium (LEU) fuel. The RELAP5/Mod 3.3 code has been used to perform transient thermal-hydraulic safety analyses of the BR2 reactor to support reactor conversion. A RELAP5 model of BR2 has been validated against select transient BR2 reactor experiments performed in 1963 by showing agreement with measured cladding temperatures. Following the validation, the RELAP5 model was then updated to represent the current use of the reactor; taking into account core configuration, neutronic parameters, trip settings, component changes, etc. Simulations of the 1963 experiments were repeated with this updated model to re-evaluate the boiling risks associated with the currently allowed maximum heat flux limit of 470 W/cm2 and temporary heat flux limit of 600 W/cm2. This document provides analysis of additional transient simulations that are required as part of a modern BR2 safety analysis report (SAR). The additional simulations included in this report are effect of pool temperature, reduced steady-state flow rate, in-pool loss of coolant accidents, and loss of external cooling. The simulations described in this document have been performed for both an HEU- and LEU-fueled core.

  15. Low Enrichment Uranium (LEU)-fueled SLOWPOKE-2 nuclear reactor simulation with the Monte-Carlo based MCNP 4A code

    International Nuclear Information System (INIS)

    Pierre, J.R.M.

    1996-01-01

    Following the commissioning of the Low Enrichment Uranium (LEU) Fuelled SLOWPOKE-2 research reactor at the Royal Military College-College Militaire Royal (RMC-CMR), excess reactivity measurements were conducted over a range of temperature and power. The results showed a maximum excess reactivity of 3.37 mk at 33 o C. Several deterministic models using computer codes like WIMS-CRNL, CITATION, TRIVAC and DRAGON have been used to try to reproduce the excess reactivity and temperature trend of both the LEU and HEU SLOWPOKE-2 reactors. The best simulations had been obtained at Ecole Polytechnique de Montreal. They were able to reproduce the temperature trend of their HEU-fuelled reactor using TRIVAC calculations, but this model over-estimated the absolute value of the excess reactivity by 119 mk. Although calculations using DRAGON did not reproduce the temperature trend as well as TRIVAC, these calculations represented a significant improvement on the absolute value at 20 o C reducing the discrepancy to 13 mk. Given the advance in computer technology, a probabilistic approach was tried in this work, using the Monte-Carlo N-Particle Transport Code System MCNP 4A, to model the RMC-CMR SLOWPOKE-2 reactor.

  16. Association between ghrelin gene (Leu72Met) polymorphism and ghrelin serum level with coronary artery diseases.

    Science.gov (United States)

    Hedayatizadeh-Omran, Akbar; Rafiei, Alireza; Khajavi, Rezvan; Alizadeh-Navaei, Reza; Mokhberi, Vahid; Moradzadeh, Kambiz

    2014-02-01

    Research shows that ghrelin gene polymorphism has some association with coronary artery diseases (CAD). Due to genetic differences among nations and the high prevalence of CAD, we conducted this study to examine the possible association between the polymorphism of ghrelin gene Leu72Met and CAD among an Iranian population. This case-control study was undertaken with patients who were referred to referral heart center, in 2011, with chest pain or a positive exercise test. Patients with risk factors for heart disease or who were surgery candidates, who underwent angiography and echocardiography, were also included. DNA extractions were performed using a modified salting out method, and the ghrelin region was amplified using polymerase chain reaction. The presence of the Leu72Met polymorphism and the serum levels of ghrelin were determined using the restriction fragment length polymorphism method and the enzyme-linked immunosorbent assay, respectively. The results indicated that in CAD patients, the incidence of heart failure was significantly different between the groups with genotypes CC or AA+CA (p=0.041). Mean serum level of ghrelin in the CAD group was significantly higher than that in the control group (pghrelin genotypes and serum levels of ghrelin in both the CAD and control groups (ppolymorphism, as well as an increase in serum levels of ghrelin associated with genotype distribution such that ghrelin levels have an inverse relationship with the frequency of the CC genotype.

  17. Crossbar H-mode drift-tube linac design with alternative phase focusing for muon linac

    Science.gov (United States)

    Otani, M.; Futatsukawa, K.; Hasegawa, K.; Kitamura, R.; Kondo, Y.; Kurennoy, S.

    2017-07-01

    We have developed a Crossbar H-mode (CH) drift-tube linac (DTL) design with an alternative phase focusing (APF) scheme for a muon linac, in order to measure the anomalous magnetic moment and electric dipole moment (EDM) of muons at the Japan Proton Accelerator Research Complex (J-PARC). The CH-DTL accelerates muons from β = v/c = 0.08 to 0.28 at an operational frequency of 324 MHz. The design and results are described in this paper.

  18. A note on “An alternative multiple attribute decision making methodology for solving optimal facility layout design selection problems”

    OpenAIRE

    R. Venkata Rao

    2012-01-01

    A paper published by Maniya and Bhatt (2011) (An alternative multiple attribute decision making methodology for solving optimal facility layout design selection problems, Computers & Industrial Engineering, 61, 542-549) proposed an alternative multiple attribute decision making method named as “Preference Selection Index (PSI) method” for selection of an optimal facility layout design. The authors had claimed that the method was logical and more appropriate and the method gives directly the o...

  19. LEU fuel fabrication program for the RECH-1 reactor. Status report

    International Nuclear Information System (INIS)

    Chavez, J.C.; Barrera, M.; Jimenez, O.; Lisboa, J.; Marin, J.

    2000-01-01

    In 1995 a 50 LEU U 3 Si 2 fuel elements fabrication program for the RECH-1 research reactor was established at the Comision Chilena de Energia Nuclear, CCHEN. After a fabrication process qualification stage, in 1998, four elements were early delivered to the reactor in order to start an irradiation qualification stage. The irradiation has reached an estimated 10% burn-up and no fabrication problems have been detected up to this burn-up level. During 1999 and up to the first quarter of 2000, 19 fuel elements were produced and 7 fuel elements are expected for the end of 2000. This report presents an updated summary of the main results obtained in this fuel fabrication program. A summary of other activities generated by this program, such as in core follow-up of the four leader fuel elements, ISO 9001 implementation for the fabrication process and a fabrication and qualification optimization planning, is also presented here. (author)

  20. Associations between GPX1 Pro198Leu polymorphism, erythrocyte GPX activity, alcohol consumption and breast cancer risk in a prospective cohort study

    DEFF Research Database (Denmark)

    Ravn-Haren, Gitte; Olsen, A.; Tjonneland, A.

    2006-01-01

    Breast cancer may be related to oxidative stress. Breast cancer patients have been reported to have lower antioxidant enzyme activity than healthy controls and the polymorphism GPX1 Pro198Leu has been associated with risk of lung and breast cancer. The purpose of the present nested case...

  1. Novel isotopic N, N-Dimethyl Leucine (iDiLeu) Reagents Enable Absolute Quantification of Peptides and Proteins Using a Standard Curve Approach

    Science.gov (United States)

    Greer, Tyler; Lietz, Christopher B.; Xiang, Feng; Li, Lingjun

    2015-01-01

    Absolute quantification of protein targets using liquid chromatography-mass spectrometry (LC-MS) is a key component of candidate biomarker validation. One popular method combines multiple reaction monitoring (MRM) using a triple quadrupole instrument with stable isotope-labeled standards (SIS) for absolute quantification (AQUA). LC-MRM AQUA assays are sensitive and specific, but they are also expensive because of the cost of synthesizing stable isotope peptide standards. While the chemical modification approach using mass differential tags for relative and absolute quantification (mTRAQ) represents a more economical approach when quantifying large numbers of peptides, these reagents are costly and still suffer from lower throughput because only two concentration values per peptide can be obtained in a single LC-MS run. Here, we have developed and applied a set of five novel mass difference reagents, isotopic N, N-dimethyl leucine (iDiLeu). These labels contain an amine reactive group, triazine ester, are cost effective because of their synthetic simplicity, and have increased throughput compared with previous LC-MS quantification methods by allowing construction of a four-point standard curve in one run. iDiLeu-labeled peptides show remarkably similar retention time shifts, slightly lower energy thresholds for higher-energy collisional dissociation (HCD) fragmentation, and high quantification accuracy for trypsin-digested protein samples (median errors <15%). By spiking in an iDiLeu-labeled neuropeptide, allatostatin, into mouse urine matrix, two quantification methods are validated. The first uses one labeled peptide as an internal standard to normalize labeled peptide peak areas across runs (<19% error), whereas the second enables standard curve creation and analyte quantification in one run (<8% error).

  2. Alternative Ultrasound Gel for a Sustainable Ultrasound Program: Application of Human Centered Design.

    Directory of Open Access Journals (Sweden)

    Margaret Salmon

    Full Text Available This paper describes design of a low cost, ultrasound gel from local products applying aspects of Human Centered Design methodology. A multidisciplinary team worked with clinicians who use ultrasound where commercial gel is cost prohibitive and scarce. The team followed the format outlined in the Ideo Took Kit. Research began by defining the challenge "how to create locally available alternative ultrasound gel for a low-resourced environment? The "End-Users," were identified as clinicians who use ultrasound in Democratic Republic of the Congo and Ethiopia. An expert group was identified and queried for possible alternatives to commercial gel. Responses included shampoo, oils, water and cornstarch. Cornstarch, while a reasonable solution, was either not available or too expensive. We then sought deeper knowledge of locally sources materials from local experts, market vendors, to develop a similar product. Suggested solutions gleaned from these interviews were collected and used to create ultrasound gel accounting for cost, image quality, manufacturing capability. Initial prototypes used cassava root flour from Great Lakes Region (DRC, Rwanda, Uganda, Tanzania and West Africa, and bula from Ethiopia. Prototypes were tested in the field and resulting images evaluated by our user group. A final prototype was then selected. Cassava and bula at a 32 part water, 8 part flour and 4 part salt, heated, mixed then cooled was the product design of choice.

  3. Alternative Ultrasound Gel for a Sustainable Ultrasound Program: Application of Human Centered Design.

    Science.gov (United States)

    Salmon, Margaret; Salmon, Christian; Bissinger, Alexa; Muller, Mundenga Mutendi; Gebreyesus, Alegnta; Geremew, Haimanot; Wendel, Sarah K; Wendell, Sarah; Azaza, Aklilu; Salumu, Maurice; Benfield, Nerys

    2015-01-01

    This paper describes design of a low cost, ultrasound gel from local products applying aspects of Human Centered Design methodology. A multidisciplinary team worked with clinicians who use ultrasound where commercial gel is cost prohibitive and scarce. The team followed the format outlined in the Ideo Took Kit. Research began by defining the challenge "how to create locally available alternative ultrasound gel for a low-resourced environment? The "End-Users," were identified as clinicians who use ultrasound in Democratic Republic of the Congo and Ethiopia. An expert group was identified and queried for possible alternatives to commercial gel. Responses included shampoo, oils, water and cornstarch. Cornstarch, while a reasonable solution, was either not available or too expensive. We then sought deeper knowledge of locally sources materials from local experts, market vendors, to develop a similar product. Suggested solutions gleaned from these interviews were collected and used to create ultrasound gel accounting for cost, image quality, manufacturing capability. Initial prototypes used cassava root flour from Great Lakes Region (DRC, Rwanda, Uganda, Tanzania) and West Africa, and bula from Ethiopia. Prototypes were tested in the field and resulting images evaluated by our user group. A final prototype was then selected. Cassava and bula at a 32 part water, 8 part flour and 4 part salt, heated, mixed then cooled was the product design of choice.

  4. Human factors in design modifications: panel alternative stop in Almaraz

    International Nuclear Information System (INIS)

    Roman, Y.; Bote, J.

    2015-01-01

    Human Factors Engineering has acquired a crucial role in the development of any design modification (DM), where every aspect relative to any interaction with the human user has to be taken into account at any stage thereof. Considering this, during the last years, Almaraz Nuclear Powe Plants has developed a program of Human Factors Engineering in order to reach the internationally recognized standards or systematic collected on NUREG 0711 Human Factors Engineering Program Review Model (NRC). One of the most important projects of this program at Almaraz Nuclear Power Plant has been the implementation of the Alternative Stop Panel and their corresponding Transfer Panels. (Author)

  5. Highlights in KMRR nuclear design

    International Nuclear Information System (INIS)

    Kim, H.R.; Kim, B.G.; Kim, Y.J.; Lee, B.C.; Lee, J.T.; Lee, J.B.

    1990-01-01

    The Korea Advanced Energy Research Institute (KAERI) is constructing the KMRR (Korea Multi-purpose Research Reactor) to meet the requirements of the nationwide nuclear programs. The KMRR is an open-tank-in-pool type reactor which uses LEU U 3 Si-Al fuel and features an LWR/HWR hybrid configuration that has advantage of easily tailoring experimental facility layout to ensure supply of effective neutron quality. KAERI established the physics design system including the shielding design specifically for the KMRR. Based on the design analyse the reactor can be operated at a thermal power output of 30 MW to suit applications ranging from material/fuel testing to beam utilization, without violating the design limits concerning fuel integrity, and the radioactivity level in the access area is kept below the design criteria of 1.25 mrem/hr

  6. An alternative design for a metal image slicing IFU for EAGLE

    Science.gov (United States)

    Dubbeldam, Cornelis M.; Robertson, David J.; Rolt, Stephen; Talbot, R. Gordon

    2012-09-01

    The Centre for Advanced Instrumentation (CfAI) of Durham University (UK) has developed a conceptual design for the Integral Field Unit (IFU) for EAGLE based on diamond-machined monolithic multi-faceted metal-mirror arrays as an alternative to the glass IFU which is currently baselined. The CfAI has built up substantial expertise with the design, manufacture, integration, alignment and acceptance testing of such systems, through the successful development of IFUs for the Gemini Near-InfraRed Spectrograph (GNIRS) and JWST NIRSpec and 24 IFUs for ESO’s K-band Multi-Object Spectrometer (KMOS). The unprecedented performance of the KMOS IFUs (Strehl risks and cost. Through the timely completion of the KMOS IFUs, which required the fabrication of an unprecedented 1152 optical surfaces, the CfAI have demonstrated that they have the capacity to produce the required volume within reasonable schedule constraints. All the facilities (design, fabrication e.g. diamond machining, metrology, integration and test) required for the successful realisation of such systems are available in-house, thus minimising programmatic risks. This paper presents the opto-mechanical design and predicted performance (based on the actual measured performance of the KMOS IFUs) of the proposed metal IFU.

  7. DESIGN STUDY FOR A LOW-ENRICHED URANIUM CORE FOR THE HIGH FLUX ISOTOPE REACTOR, ANNUAL REPORT FOR FY 2010

    Energy Technology Data Exchange (ETDEWEB)

    Cook, David Howard [ORNL; Freels, James D [ORNL; Ilas, Germina [ORNL; Jolly, Brian C [ORNL; Miller, James Henry [ORNL; Primm, Trent [ORNL; Renfro, David G [ORNL; Sease, John D [ORNL; Pinkston, Daniel [ORNL

    2011-02-01

    This report documents progress made during FY 2010 in studies of converting the High Flux Isotope Reactor (HFIR) from high enriched uranium (HEU) fuel to low enriched uranium (LEU) fuel. Conversion from HEU to LEU will require a change in fuel form from uranium oxide to a uranium-molybdenum alloy. With axial and radial grading of the fuel foil and an increase in reactor power to 100 MW, calculations indicate that the HFIR can be operated with LEU fuel with no degradation in performance to users from the current level. Studies are reported of support to a thermal hydraulic test loop design, the implementation of finite element, thermal hydraulic analysis capability, and infrastructure tasks at HFIR to upgrade the facility for operation at 100 MW. A discussion of difficulties with preparing a fuel specification for the uranium-molybdenum alloy is provided. Continuing development in the definition of the fuel fabrication process is described.

  8. Designing a suitable alternative to oil-based mud

    International Nuclear Information System (INIS)

    Holgate, M.; Irwin, G.; Cousins, L.

    1991-01-01

    This paper reports on wireline logging problems which have plagued the reservoir section of development wells in Welton oil field in the East Midlands area of England. And resulting incomplete or poor-quality logging data spurred a look at ways of improving hole conditions. Oil-based muds often are seen as the ideal solution, but they are expensive. Their use also commits the operator to additional costs from safeguarding personnel and limiting environmental impact. Such expense was initiated to develop a cheaper, more environmentally friendly, water-based alternative. A wide-ranging review was carried out to determine the most cost-effective options to obtain reservoir information. This included an examination of lithology, casing design, bit selection, hydraulics, logging requirements and techniques, and development of a suitable water-based mud. This holistic approach was seen as the most effective method of avoiding use of oil-based mud. After successful experimentation, a water-based mud was used in subsequent wells at Welton. A high-salt mud system and the drilling principles discussed here produced significant improvement in hole conditions. Application of a holistic approach led to many operational improvements. For instance, the casing shoe was deepened to case off the most troublesome zone in the local Edlington formation. There also was a better awareness of alternative logging techniques, the commercial factors that influenced their use and their operational and technical limitations. Logging problems were reduced but not eliminated. Where there were problems, application of improved techniques minimized their impact. Last, but not least, there was an unexpected spin-off in that the bit chosen to reduce hole erosion also reduced the time taken to drill the section

  9. An alternative design of reference blocks during the ultrasonic of ferritic welded joints

    International Nuclear Information System (INIS)

    Rondon Torriente, S.; Galeano Alvarez, N.J.

    1996-01-01

    This paper describes an alternative design which can be used to construct the reference blocks required to make the sensibility adjustment during the ultrasonic control ferritic welded joints. The major possibilities of this design are seen when it's used together with the well known AVG method, however it can be properly used with the reference block technique. In addition, the most general facts to keep in mind during the construction of this means are outlined, and besides advantages and problems involved with the use of some basics reference reflectors of wide spread use. Also formulates are given that can be used to obtain the size of the disk shaped reflector corresponding to the basics reference reflectors that this design includes

  10. Introduction of water into the heme distal side by Leu65 mutations of an oxygen sensor, YddV, generates verdoheme and carbon monoxide, exerting the heme oxygenase reaction.

    Science.gov (United States)

    Stranava, Martin; Martínková, Markéta; Stiborová, Marie; Man, Petr; Kitanishi, Kenichi; Muchová, Lucie; Vítek, Libor; Martínek, Václav; Shimizu, Toru

    2014-11-01

    The globin-coupled oxygen sensor, YddV, is a heme-based oxygen sensor diguanylate cyclase. Oxygen binding to the heme Fe(II) complex in the N-terminal sensor domain of this enzyme substantially enhances its diguanylate cyclase activity which is conducted in the C-terminal functional domain. Leu65 is located on the heme distal side and is important for keeping the stability of the heme Fe(II)-O2 complex by preventing the entry of the water molecule to the heme complex. In the present study, it was found that (i) Escherichia coli-overexpressed and purified L65N mutant of the isolated heme-bound domain of YddV (YddV-heme) contained the verdoheme iron complex and other modified heme complexes as determined by optical absorption spectroscopy and mass spectrometry; (ii) CO was generated in the reconstituted system composed of heme-bound L65N and NADPH:cytochrome P450 reductase as confirmed by gas chromatography; (iii) CO generation of heme-bound L65N in the reconstituted system was inhibited by superoxide dismutase and catalase. In a concordance with the result, the reactive oxygen species increased the CO generation; (iv) the E. coli cells overexpressing the L65N protein of YddV-heme also formed significant amounts of CO compared to the cells overexpressing the wild type protein; (v) generation of verdoheme and CO was also observed for other mutants at Leu65 as well, but to a lesser extent. Since Leu65 mutations are assumed to introduce the water molecule into the heme distal side of YddV-heme, it is suggested that the water molecule would significantly contribute to facilitating heme oxygenase reactions for the Leu65 mutants. Copyright © 2014 Elsevier Inc. All rights reserved.

  11. Manufacturing and investigation of U-Mo LEU fuel granules by hydride-dehydride processing

    International Nuclear Information System (INIS)

    Stetskiy, Y.A.; Trifonov, Y.I.; Mitrofanov, A.V.; Samarin, V.I.

    2002-01-01

    Investigations of hydride-dehydride processing for comminution of U-Mo alloys with Mo content in the range 1.9/9.2% have been performed. Some regularities of the process as a function of Mo content have been determined as well as some parameters elaborated. Hydride-dehydride processing has been shown to provide necessary phase and chemical compositions of U-Mo fuel granules to be used in disperse fuel elements for research reactors. Pin type disperse mini-fuel elements for irradiation tests in the loop of 'MIR' reactor (Dmitrovgrad) have been fabricated using U-Mo LEU fuel granules obtained by hydride-dehydride processing. Irradiation tests of these mini-fuel elements loaded to 4 g U tot /cm 3 are planned to start by the end of this year. (author)

  12. A neutronics feasibility study for the LEU conversion of Poland's Maria research reactor

    International Nuclear Information System (INIS)

    Bretscher, M. M.

    1998-01-01

    The MARIA reactor is a high-flux multipurpose research reactor which is water-cooled and moderated with both beryllium and water. Standard HEU (80% 235 U)fuel assemblies consist of six concentric fuel tubes of a U-Al alloy clad in aluminum. Although the inventory of HEU (80%) fuel is nearly exhausted, a supply of highly-loaded 36%-enriched fuel assemblies is available at the reactor site. Neutronic equilibrium studies have been made to determine the relative performance of fuels with enrichments of 80%, 36% and 19.7%. These studies indicate that LEU (19.7%) densities of about 2.5 gU/cm 3 and 3.8 gU/cm 3 are required to match the performance of the MARIA reactor with 80%-enriched and with 36%-enriched fuels, respectively

  13. A Alternative Analog Circuit Design Methodology Employing Integrated Artificial Intelligence Techniques

    Science.gov (United States)

    Tuttle, Jeffery L.

    In consideration of the computer processing power now available to the designer, an alternative analog circuit design methodology is proposed. Computer memory capacities no longer require the reduction of the transistor operational characteristics to an imprecise formulation. Therefore, it is proposed that transistor modelling be abandoned in favor of fully characterized transistor data libraries. Secondly, availability of the transistor libraries would facilitate an automated selection of the most appropriate device(s) for the circuit being designed. More specifically, a preprocessor computer program to a more sophisticated circuit simulator (e.g. SPICE) is developed to assist the designer in developing the basic circuit topology and the selection of the most appropriate transistor. Once this is achieved, the circuit topology and selected transistor data library would be downloaded to the simulator for full circuit operational characterization and subsequent design modifications. It is recognized that the design process is enhanced by the use of heuristics as applied to iterative design results. Accordingly, an artificial intelligence (AI) interface is developed to assist the designer in applying the preprocessor results. To demonstrate the retrofitability of the AI interface to established programs, the interface is specifically designed to be as non-intrusive to the host code as possible. Implementation of the proposed methodology offers the potential to speed the design process, since the preprocessor both minimizes the required number of simulator runs and provides a higher acceptance potential of the initial and subsequent simulator runs. Secondly, part count reductions may be realizable since the circuit topologies are not as strongly driven by transistor limitations. Thirdly, the predicted results should more closely match actual circuit operations since the inadequacies of the transistor models have been virtually eliminated. Finally, the AI interface

  14. Evidence for an association between the Leu162Val polymorphism of the PPARalpha gene and decreased fasting serum triglyceride levels in glucose tolerant subjects

    DEFF Research Database (Denmark)

    Nielsen, Eva-Maria D; Hansen, Lars; Echwald, Søren Morgenthaler

    2003-01-01

    The aim of the study was to investigate whether genetic variation in the peroxisome proliferator-activated receptor-alpha (PPARalpha) is associated with type 2 diabetes and altered lipid or carbohydrate metabolism in glucose tolerant subjects. Mutation analyses of PPARalpha were performed in 56...... type 2 diabetic patients. Six variants were identified: IVS3 + 76T>C, IVS3-19C>T, IVS4 + 35C>T, Leu162Val, Arg178Gly and Ala268Val. In a case-control study comprising 738 type 2 diabetic patients and 524 glucose tolerant subjects, the three exon variants did not show any significant differences...... in allele frequencies between type 2 diabetic patients and control subjects. The functional Leu162Val polymorphism was further investigated in genotype-phenotype studies involving 340 young, healthy subjects and 502 middle-aged glucose tolerant subjects. The young, healthy subjects who were heterozygous...

  15. Critical appraisal of arguments for the delayed-start design proposed as alternative to the parallel-group randomized clinical trial design in the field of rare disease.

    Science.gov (United States)

    Spineli, Loukia M; Jenz, Eva; Großhennig, Anika; Koch, Armin

    2017-08-17

    A number of papers have proposed or evaluated the delayed-start design as an alternative to the standard two-arm parallel group randomized clinical trial (RCT) design in the field of rare disease. However the discussion is felt to lack a sufficient degree of consideration devoted to the true virtues of the delayed start design and the implications either in terms of required sample-size, overall information, or interpretation of the estimate in the context of small populations. To evaluate whether there are real advantages of the delayed-start design particularly in terms of overall efficacy and sample size requirements as a proposed alternative to the standard parallel group RCT in the field of rare disease. We used a real-life example to compare the delayed-start design with the standard RCT in terms of sample size requirements. Then, based on three scenarios regarding the development of the treatment effect over time, the advantages, limitations and potential costs of the delayed-start design are discussed. We clarify that delayed-start design is not suitable for drugs that establish an immediate treatment effect, but for drugs with effects developing over time, instead. In addition, the sample size will always increase as an implication for a reduced time on placebo resulting in a decreased treatment effect. A number of papers have repeated well-known arguments to justify the delayed-start design as appropriate alternative to the standard parallel group RCT in the field of rare disease and do not discuss the specific needs of research methodology in this field. The main point is that a limited time on placebo will result in an underestimated treatment effect and, in consequence, in larger sample size requirements compared to those expected under a standard parallel-group design. This also impacts on benefit-risk assessment.

  16. Reactor Physics Methods and Preconceptual Core Design Analyses for Conversion of the Advanced Test Reactor to Low-Enriched Uranium Fuel Annual Report for Fiscal Year 2012

    Energy Technology Data Exchange (ETDEWEB)

    David W. Nigg; Sean R. Morrell

    2012-09-01

    Under the current long-term DOE policy and planning scenario, both the ATR and the ATRC will be reconfigured at an appropriate time within the next several years to operate with low-enriched uranium (LEU) fuel. This will be accomplished under the auspices of the Reduced Enrichment Research and Test Reactor (RERTR) Program, administered by the DOE National Nuclear Security Administration (NNSA). At a minimum, the internal design and composition of the fuel element plates and support structure will change, to accommodate the need for low enrichment in a manner that maintains total core excess reactivity at a suitable level for anticipated operational needs throughout each cycle while respecting all control and shutdown margin requirements and power distribution limits. The complete engineering design and optimization of LEU cores for the ATR and the ATRC will require significant multi-year efforts in the areas of fuel design, development and testing, as well as a complete re-analysis of the relevant reactor physics parameters for a core composed of LEU fuel, with possible control system modifications. Ultimately, revalidation of the computational physics parameters per applicable national and international standards against data from experimental measurements for prototypes of the new ATR and ATRC core designs will also be required for Safety Analysis Report (SAR) changes to support routine operations with LEU. This report is focused on reactor physics analyses conducted during Fiscal Year (FY) 2012 to support the initial development of several potential preconceptual fuel element designs that are suitable candidates for further study and refinement during FY-2013 and beyond. In a separate, but related, effort in the general area of computational support for ATR operations, the Idaho National Laboratory (INL) is conducting a focused multiyear effort to introduce modern high-fidelity computational reactor physics software and associated validation protocols to replace

  17. Benchmarking the new JENDL-4.0 library on criticality experiments of a research reactor with oxide LEU (20 w/o) fuel, light water moderator and beryllium reflectors

    International Nuclear Information System (INIS)

    Liem, Peng Hong; Sembiring, Tagor Malem

    2012-01-01

    Highlights: ► Benchmark calculations of the new JENDL-4.0 library. ► Thermal research reactor with oxide LEU fuel, H 2 O moderator and Be reflector. ► JENDL-4.0 library shows better C/E values for criticality evaluations. - Abstract: Benchmark calculations of the new JENDL-4.0 library on the criticality experiments of a thermal research reactor with oxide low enriched uranium (LEU, 20 w/o) fuel, light water moderator and beryllium reflector (RSG GAS) have been conducted using a continuous energy Monte Carlo code, MVP-II. The JENDL-4.0 library shows better C/E values compared to the former library JENDL-3.3 and other world-widely used latest libraries (ENDF/B-VII.0 and JEFF-3.1).

  18. Large-scale studies of the Leu72Met polymorphism of the ghrelin gene in relation to the metabolic syndrome and associated quantitative traits

    DEFF Research Database (Denmark)

    Bing, C; Ambye, L; Fenger, M

    2005-01-01

    Recently, low-frequency polymorphisms in the coding region of the ghrelin gene were suggested to be involved in the aetiology of obesity and to modulate glucose-induced insulin secretion in different ethnic study groups. The objective of the present large study was to investigate whether the Leu7...

  19. Exploration of alternate catalytic mechanisms and optimization strategies for retroaldolase design.

    Science.gov (United States)

    Bjelic, Sinisa; Kipnis, Yakov; Wang, Ling; Pianowski, Zbigniew; Vorobiev, Sergey; Su, Min; Seetharaman, Jayaraman; Xiao, Rong; Kornhaber, Gregory; Hunt, John F; Tong, Liang; Hilvert, Donald; Baker, David

    2014-01-09

    Designed retroaldolases have utilized a nucleophilic lysine to promote carbon-carbon bond cleavage of β-hydroxy-ketones via a covalent Schiff base intermediate. Previous computational designs have incorporated a water molecule to facilitate formation and breakdown of the carbinolamine intermediate to give the Schiff base and to function as a general acid/base. Here we investigate an alternative active-site design in which the catalytic water molecule was replaced by the side chain of a glutamic acid. Five out of seven designs expressed solubly and exhibited catalytic efficiencies similar to previously designed retroaldolases for the conversion of 4-hydroxy-4-(6-methoxy-2-naphthyl)-2-butanone to 6-methoxy-2-naphthaldehyde and acetone. After one round of site-directed saturation mutagenesis, improved variants of the two best designs, RA114 and RA117, exhibited among the highest kcat (>10(-3)s(-1)) and kcat/KM (11-25M(-1)s(-1)) values observed for retroaldolase designs prior to comprehensive directed evolution. In both cases, the >10(5)-fold rate accelerations that were achieved are within 1-3 orders of magnitude of the rate enhancements reported for the best catalysts for related reactions, including catalytic antibodies (kcat/kuncat=10(6) to 10(8)) and an extensively evolved computational design (kcat/kuncat>10(7)). The catalytic sites, revealed by X-ray structures of optimized versions of the two active designs, are in close agreement with the design models except for the catalytic lysine in RA114. We further improved the variants by computational remodeling of the loops and yeast display selection for reactivity of the catalytic lysine with a diketone probe, obtaining an additional order of magnitude enhancement in activity with both approaches. © 2013.

  20. PDRD (SR13046) TRITIUM PRODUCTION FINAL REPORT

    Energy Technology Data Exchange (ETDEWEB)

    Smith, P.; Sheetz, S.

    2013-09-30

    Utilizing the results of Texas A&M University (TAMU) senior design projects on tritium production in four different small modular reactors (SMR), the Savannah River National Laboratory’s (SRNL) developed an optimization model evaluating tritium production versus uranium utilization under a FY2013 plant directed research development (PDRD) project. The model is a tool that can evaluate varying scenarios and various reactor designs to maximize the production of tritium per unit of unobligated United States (US) origin uranium that is in limited supply. The primary module in the model compares the consumption of uranium for various production reactors against the base case of Watts Bar I running a nominal load of 1,696 tritium producing burnable absorber rods (TPBARs) with an average refueling of 41,000 kg low enriched uranium (LEU) on an 18 month cycle. After inputting an initial year, starting inventory of unobligated uranium and tritium production forecast, the model will compare and contrast the depletion rate of the LEU between the entered alternatives. This is an annual tritium production rate of approximately 0.059 grams of tritium per kilogram of LEU (g-T/kg-LEU). To date, the Nuclear Regulatory Commission (NRC) license has not been amended to accept a full load of TPBARs so the nominal tritium production has not yet been achieved. The alternatives currently loaded into the model include the three light water SMRs evaluated in TAMU senior projects including, mPower, Holtec and NuScale designs. Initial evaluations of tritium production in light water reactor (LWR) based SMRs using optimized loads TPBARs is on the order 0.02-0.06 grams of tritium per kilogram of LEU used. The TAMU students also chose to model tritium production in the GE-Hitachi SPRISM, a pooltype sodium fast reactor (SFR) utilizing a modified TPBAR type target. The team was unable to complete their project so no data is available. In order to include results from a fast reactor, the SRNL

  1. Molecular cloning of Ly-1, a membrane glycoprotein of mouse T lymphocytes and a subset of B cells: molecular homology to its human counterpart Leu-1/T1 (CD5)

    International Nuclear Information System (INIS)

    Huang, H.J.S.; Jones, N.H.; Strominger, J.L.; Herzenberg, L.A.

    1987-01-01

    The authors report the isolation of cDNA clones of the mouse lymphocyte differentiation antigen Ly-1. One of these cDNA clones was confirmed to be full-length by DNA sequencing and by expression of Ly-1 by L cells transfected with this clone. Analysis of the predicted amino acid sequence indicated that the Ly-1 polypeptide is synthesized with a 23 amino acid leader and that the mature protein consists of an amino-terminal region of 347 amino acids, a transmembrane sequence of 30 residues, and a carboxyl-terminal region of 94 amino acids. The amino-terminal region appears to be divided into two subregions by a threonine- and proline-rich sequence of 23 amino acids that is highly conserved between Ly-1 and its human homologue Leu-1 (CD5) in position and amino acid composition. The first amino-terminal subregion of 111 amino acids is predicted to be arranged in a β-pleated sheet structure of six strands. The entire amino-terminal region is rich in cysteine, with all of its 22 cysteine residues conserved between Ly-1 and Leu-1. The carboxyl-terminal region has no cysteins. Ly-1 and Leu-1 are 63% identical, with a gradient of identical residues from 43% for the first amino-terminal to 58% for the second amino-terminal subregion and 90% for the carboxyl-terminal region. The predicted secondary structure of the first amino-terminal subregion and identities of certain conserved residues among most members of the immunoglobulin gene superfamily suggest that Ly-1 and Leu-1 are distant members of this family

  2. Alternate MIMO AF relaying networks with interference alignment: Spectral efficient protocol and linear filter design

    KAUST Repository

    Park, Kihong

    2013-02-01

    In this paper, we study a two-hop relaying network consisting of one source, one destination, and three amplify-and-forward (AF) relays with multiple antennas. To compensate for the capacity prelog factor loss of 1/2$ due to the half-duplex relaying, alternate transmission is performed among three relays, and the inter-relay interference due to the alternate relaying is aligned to make additional degrees of freedom. In addition, suboptimal linear filter designs at the nodes are proposed to maximize the achievable sum rate for different fading scenarios when the destination utilizes a minimum mean-square error filter. © 1967-2012 IEEE.

  3. Increasing spelling achievement: an analysis of treatment procedures utilizing an alternating treatments design.

    OpenAIRE

    Ollendick, T H; Matson, J L; Esveldt-Dawson, K; Shapiro, E S

    1980-01-01

    Two studies which examine the effectiveness of spelling remediation procedures are reported. In both studies, an alternating treatment design was employed. In the first study, positive practice overcorrection plus positive reinforcement was compared to positive practice alone and a no-remediation control condition. In the second study, positive practice plus positive reinforcement was compared to a traditional corrective procedure plus positive reinforcement and a traditional procedure when u...

  4. Methodology for assessing the impacts of alternative rate designs on industrial energy use. Draft report

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-01-11

    A task was undertaken to develop a method for analyzing industrial user responses to alternative rate designs. The method described considers the fuel switching and conservation responses of industrial users and the impact to a hypothetical utility regarding revenue stability, annual gas demand, and seasonal fluctuations. Twenty-seven hypothetical industrial plant types have been specified. For each combustor in the plant, the fuel consumption by season, initial fuel type, fuel switching costs, conservation costs, and amount of fuel conservable is provided. The decision making takes place at the plant level and is aggregated to determine the impact to the utility. Section 2 discusses the factors affecting an industrial user's response to alternative rate designs. Section 3 describes the methodology, includes an overview of the model and an example industrial user's response to a set of fuel prices. The data describing the 27 hypothetical firms is in an appendix.

  5. A fungal P450 (CYP5136A3 capable of oxidizing polycyclic aromatic hydrocarbons and endocrine disrupting alkylphenols: role of Trp(129 and Leu(324.

    Directory of Open Access Journals (Sweden)

    Khajamohiddin Syed

    Full Text Available The model white rot fungus Phanerochaete chrysosporium, which is known for its versatile pollutant-biodegradation ability, possesses an extraordinarily large repertoire of P450 monooxygenases in its genome. However, the majority of these P450s have hitherto unknown function. Our initial studies using a genome-wide gene induction strategy revealed multiple P450s responsive to individual classes of xenobiotics. Here we report functional characterization of a cytochrome P450 monooxygenase, CYP5136A3 that showed common responsiveness and catalytic versatility towards endocrine-disrupting alkylphenols (APs and mutagenic/carcinogenic polycyclic aromatic hydrocarbons (PAHs. Using recombinant CYP5136A3, we demonstrated its oxidation activity towards APs with varying alkyl side-chain length (C3-C9, in addition to PAHs (3-4 ring size. AP oxidation involves hydroxylation at the terminal carbon of the alkyl side-chain (ω-oxidation. Structure-activity analysis based on a 3D model indicated a potential role of Trp(129 and Leu(324 in the oxidation mechanism of CYP5136A3. Replacing Trp(129 with Leu (W129L and Phe (W129F significantly diminished oxidation of both PAHs and APs. The W129L mutation caused greater reduction in phenanthrene oxidation (80% as compared to W129F which caused greater reduction in pyrene oxidation (88%. Almost complete loss of oxidation of C3-C8 APs (83-90% was observed for the W129L mutation as compared to W129F (28-41%. However, the two mutations showed a comparable loss (60-67% in C9-AP oxidation. Replacement of Leu(324 with Gly (L324G caused 42% and 54% decrease in oxidation activity towards phenanthrene and pyrene, respectively. This mutation also caused loss of activity towards C3-C8 APs (20-58%, and complete loss of activity toward nonylphenol (C9-AP. Collectively, the results suggest that Trp(129 and Leu(324 are critical in substrate recognition and/or regio-selective oxidation of PAHs and APs. To our knowledge, this is the first

  6. NASA Alternative Orion Small Cell Battery Design Support

    Science.gov (United States)

    Haynes, Chuck

    2016-01-01

    and analysis were completed and reviewed for endorsement by NASA Engineering and Safety Center team members. All Key Test Objectives were met and the small cell design alternative was demonstrated and selected to be a feasible drop in replacement for the MPCV Orion CM Battery for EM2 mission.

  7. Preliminary radiological consequence estimate for a reference LEU core for PARR

    International Nuclear Information System (INIS)

    Younus, M.; Khan, L.A.; Akhtar, K.M.; Pervez, S.

    1988-07-01

    Radiological consequence analysis of a reference LEU core for Pakistan Research Reactor (PARR) has been carried out using mathematical models. Three modes of leakage from reactor building have been considered. These are exhaust through the normal ventilation system, through emergency ventilation system and leakage from the building. The whole body and thyroid does have been calculated for the duration of 2 hours and 30 days at the boundaries of exclusion zone at 450m and low population zone at 100m. For the releases at stack height through normal and emergency ventilation systems, does at both the boundaries remain within relevant emergency does limits of 300 rem for thyroid and 25 rem for whole body. However, in case of direct release from the containment building, limiting thyroid does of 300 rem, at 1000m, for 30 days exposure is achieved for a leak rate of 27% per day under Pasquill condition E. The results presented in this report are only preliminary estimates. A more accurate detailed analysis, for various burnups, will be carried using standard computer codes. (orig./A.B)

  8. Theoretical study on the interaction of pyrrolopyrimidine derivatives as LIMK2 inhibitors: insight into structure-based inhibitor design.

    Science.gov (United States)

    Shen, Mingyun; Zhou, Shunye; Li, Youyong; Li, Dan; Hou, Tingjun

    2013-10-01

    LIM kinases (LIMKs), downstream of Rho-associated protein kinases (ROCKs) and p21-activated protein kinases (PAKs), are shown to be promising targets for the treatment of cancers. In this study, the inhibition mechanism of 41 pyrrolopyrimidine derivatives as LIMK2 inhibitors was explored through a series of theoretical approaches. First, a model of LIMK2 was generated through molecular homology modeling, and the studied inhibitors were docked into the binding active site of LIMK2 by the docking protocol, taking into consideration the flexibility of the protein. The binding poses predicted by molecular docking for 17 selected inhibitors with different bioactivities complexed with LIMK2 underwent molecular dynamics (MD) simulations, and the binding free energies for the complexes were predicted by using the molecular mechanics/generalized born surface area (MM/GBSA) method. The predicted binding free energies correlated well with the experimental bioactivities (r(2) = 0.63 or 0.62). Next, the free energy decomposition analysis was utilized to highlight the following key structural features related to biological activity: (1) the important H-bond between Ile408 and pyrrolopyrimidine, (2) the H-bonds between the inhibitors and Asp469 and Gly471 which maintain the stability of the DFG-out conformation, and (3) the hydrophobic interactions between the inhibitors and several key residues (Leu337, Phe342, Ala345, Val358, Lys360, Leu389, Ile408, Leu458 and Leu472). Finally, a variety of LIMK2 inhibitors with a pyrrolopyrimidine scaffold were designed, some of which showed improved potency according to the predictions. Our studies suggest that the use of molecular docking with MD simulations and free energy calculations could be a powerful tool for understanding the binding mechanism of LIMK2 inhibitors and for the design of more potent LIMK2 inhibitors.

  9. Design of sustainable chemical processes: Systematic retrofit analysis, generation and evaluation alternatives

    DEFF Research Database (Denmark)

    Carvalho, Ana; Gani, Rafiqul; Matos, Henrique

    2008-01-01

    eliminating the need to identify trade-off-based solutions. These indicators are also able to reduce (where feasible) a set of safety indicators. An indicator sensitivity analysis algorithm has been added to the methodology to define design targets and to generate sustainable process alternatives. A computer-aided...... tool has been developed to facilitate the calculations needed for the application of the methodology. The application of the indicator-based methodology and the developed software are highlighted through a process flowsheet for the production of vinyl chlorine monomer (VCM)....

  10. Hb Nouakchott [α114(GH2)Pro→Leu; HBA1: c.344C>T], A Second and Third Case Described in Two Unrelated Dutch Families.

    Science.gov (United States)

    Pondman, Kirsten M; Brinkman, Jacoline W; van der Straaten, Hanneke M; Stroobants, An K; Harteveld, Cornelis L

    2018-01-01

    We report two families, members of which are carriers of a hemoglobin (Hb) variant previously described as Hb Nouakchott [α114(GH2)Pro→Leu; HBA1: c.344C>T; p.Pro115Leu]. In the first family of Dutch origin, the proband, a 32-year-old male and his 65-year-old father, were both carriers of Hb Nouakchott. Of the second family we tested, only the proband, a 56-year-old Dutch female was a Hb Nouakchott carrier. Hematological analyses of these cases showed the anomaly behaves as a silent Hb variant without clinical consequences. The Hb variant remained unnoticed using high performance liquid chromatography (HPLC), while an additional peak was detected by capillary electrophoresis (CE). These independent findings of Hb Nouakchott indicate that this Hb variant might not be very rare, but simply remains under diagnosed depending on the Hb separation technique used.

  11. TGFbeta1 (Leu10Pro), p53 (Arg72Pro) can predict for increased risk for breast cancer in south Indian women and TGFbeta1 Pro (Leu10Pro) allele predicts response to neo-adjuvant chemo-radiotherapy.

    Science.gov (United States)

    Rajkumar, Thangarajan; Samson, Mani; Rama, Ranganathan; Sridevi, Veluswami; Mahji, Urmila; Swaminathan, Rajaraman; Nancy, Nirmala K

    2008-11-01

    The breast cancer incidence has been increasing in the south Indian women. A case (n=250)-control (n=500) study was undertaken to investigate the role of Single Nucleotide Polymorphisms (SNP's) in GSTM1 (Present/Null); GSTP1 (Ile105Val), p53 (Arg72Pro), TGFbeta1 (Leu10Pro), c-erbB2 (Ile655Val), and GSTT1 (Null/Present) in breast cancer. In addition, the value of the SNP's in predicting primary tumor's pathologic response following neo-adjuvant chemo-radiotherapy was assessed. Genotyping was done using PCR (GSTM1, GSTT1), Taqman Allelic discrimination assay (GSTP1, c-erbB2) and PCR-CTPP (p53 and TGFbeta1). None of the gene SNP's studied were associated with a statistically significant increased risk for the breast cancer. However, combined analysis of the SNP's showed that p53 (Arg/Arg and Arg/Pro) with TGFbeta1 (Pro/Pro and Leu/Pro) were associated with greater than 2 fold increased risk for breast cancer in Univariate (P=0.01) and Multivariate (P=0.003) analysis. There was no statistically significant association for the GST family members with the breast cancer risk. TGFbeta1 (Pro/Pro) allele was found to predict complete pathologic response in the primary tumour following neo-adjuvant chemo-radiotherapy (OR=6.53 and 10.53 in Univariate and Multivariate analysis respectively) (P=0.004) and was independent of stage. This study suggests that SNP's can help predict breast cancer risk in south Indian women and that TGFbeta1 (Pro/Pro) allele is associated with a better pCR in the primary tumour.

  12. Fabrication and irradiation testing of LEU [low enriched uranium] fuels at CRNL status as of 1987 September

    International Nuclear Information System (INIS)

    Sears, D.F.; Berthiaume, L.C.; Herbert, L.N.

    1987-01-01

    The current status of Chalk River Nuclear Laboratories' (CRNL) program to develop and test low-enriched uranium (LEU), proliferation-resistant fuels for use in research reactors is reviewed. CRNL's fuel manufacturing process has been qualified by the successful demonstration irradiation of 7 full-size rods in the NRU reactor. Now industrial-scale production equipment has been commissioned, and a fuel-fabrication campaign for 30 NRU rods and a MAPLE-X core is underway. Excess capacity could be used for commercial fuel fabrication. In the irradiation testing program, mini-elements with deliberately included core surface defects performed well in-reactor, swelling by only 7 to 8 vol% at 93 atomic percent burnup of the original U-235. The additional restraint provided by the aluminium cladding which flowed into the defects during extrusion contributed to this good performance. Mini-elements containing a variety of particle size distributions were also successfully irradiated to 93 at% burnup in NRU, as part of a study to establish the optimum particle size distribution. Swelling was found to be proportional to the percentage of fines (<44μm particles) contained in the cores. The mini-elements containing the composition normally used at CRNL had swollen by 5.8 vol%, and mini-elements with a much higher percentage of fines had swollen by 6.8 vol%, at 93 at% burnup. Also, a program to develop LEU targets for Mo-99 production, via the technology developed to fabricate dispersed silicide fuel, has started, and preliminary scoping studies are underway. (Author)

  13. Feed-water heaters alternative design comparison; Comparacion de disenos alternativos de calentadores

    Energy Technology Data Exchange (ETDEWEB)

    Torres Toledano, Gerardo [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1988-12-31

    A procedure is presented for the alternative design comparison of feed water heaters, based in the failure records of damaged tubes during operation. The procedure is used for cases in which non-continuous or random inspections are made to the feed-water heaters. [Espanol] Se presenta un procedimiento para comparar disenos alternativos de calentadores, basandose en los registros de fallas de los tubos rotos acumuladas durante su operacion. El procedimiento se emplea para casos en los que se realizan inspecciones a los calentadores no continuas, ya sea periodicas o al azar.

  14. Interim Report on Mixing During the Casting of LEU-10Mo Plates in the Triple Plate Molds

    Energy Technology Data Exchange (ETDEWEB)

    Aikin, Jr., Robert M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-04-12

    LEU-10%Mo castings are commonly produced by down blending unalloyed HEU with a DU-12.7%Mo master-alloy. This work uses process modeling to provide insight into the mixing of the unalloyed uranium and U-Mo master alloy during melting and mold filling of a triple plate casting. Two different sets of situations are considered: (1) mixing during mold filling from a compositionally stratified crucible and (2) convective mixing of a compositionally stratified crucible during mold heating. The mold filling simulations are performed on the original Y-12 triple plate mold and the horizontal triple plate mold.

  15. The alternative library

    OpenAIRE

    Collinson, Timothy; Williams, A.

    2004-01-01

    Much time and effort has been devoted to designing and developing library Web sites that are easy to navigate by both new students and experienced researchers. In a review of the Southampton Institute Library it was decided that in addition to updating the existing homepage an alternative would be offered. Drawing on theory relating to user interface design, learning styles and creative thinking, an Alternative Library navigation system was added to the more traditional library homepage. The ...

  16. Photoreceptor Differentiation following Transplantation of Allogeneic Retinal Progenitor Cells to the Dystrophic Rhodopsin Pro347Leu Transgenic Pig

    DEFF Research Database (Denmark)

    Klassen, H; Kiilgaard, Jens Folke; Warfvinge, K

    2012-01-01

    Purpose. Transplantation of stem, progenitor, or precursor cells has resulted in photoreceptor replacement and evidence of functional efficacy in rodent models of retinal degeneration. Ongoing work has been directed toward the replication of these results in a large animal model, namely, the pig....... Methods. Retinal progenitor cells were derived from the neural retina of GFP-transgenic pigs and transplanted to the subretinal space of rhodopsin Pro347Leu-transgenic allorecipients, in the early stage of the degeneration and the absence of immune suppression. Results. Results confirm the survival...

  17. Accurate Determination of Leucine and Valine Side-chain Conformations using U-[15N/13C/2H]/[1H-(methine/methyl)-Leu/Val] Isotope Labeling, NOE Pattern Recognition, and Methine Cγ-Hγ/Cβ-Hβ Residual Dipolar Couplings

    International Nuclear Information System (INIS)

    Tang, Chun; Iwahara, Junji; Clore, G. Marius

    2005-01-01

    An isotope labeling scheme is described in which specific protonation of methine and methyl protons of leucine and valine is obtained on a 15 N/ 13 C labeled background with uniform deuteration of all other non-exchangeable protons. The presence of a protonated methine group has little effect on the favorable relaxation properties of the methyl protons of Leu and Val. This labeling scheme permits the rotameric state of leucine side-chains to be readily determined by simple inspection of the pattern of Hγ(i)-H N (i) and Hγ(i)-H N (i+1) NOEs in a 3D 15 N-separated NOE spectrum free of complications arising from spectral overlap and spin-diffusion. In addition, one-bond residual dipolar couplings for the methine 13 C- 1 H bond vectors of Leu and Val can be accurately determined from an intensity J-modulated constant-time HCCH-COSY experiment and used to accurately orient the side-chains of Leu and Val. Incorporation of these data into structure refinement improves the accuracy with which the conformations of Leu and Val side-chains can be established. This is important to ensure optimal packing both within the protein core and at intermolecular interfaces. The impact of the method on protein structure determination is illustrated by application to enzyme IIA Chitobiose , a 34 kDa homotrimeric phosphotransferase protein

  18. Assessment of alternative vessel and blanket design on ITER operation

    Energy Technology Data Exchange (ETDEWEB)

    Cavinato, M., E-mail: mario.cavinato@f4e.europa.e [FUSION FOR ENERGY Joint Undertaking, 08019 Barcelona (Spain); Portone, A.; Saibene, G.; Sartori, R. [FUSION FOR ENERGY Joint Undertaking, 08019 Barcelona (Spain); Albanese, R.; Ambrosino, G.; Ariola, M. [Associazione Euratom-ENEA-CREATE, DIMET, Universita degli Studi di Napoli (Italy); Artaserse, G. [Associazione Euratom-ENEA-CREATE, DIMET, Universita degli Studi di Reggio Calabria (Italy); Mattei, M. [Associazione Euratom-ENEA-CREATE, DIAM, Seconda Universita di Napoli, Via Roma 29, Aversa, CE 81031 Italy (Italy); Pironti, A. [Associazione Euratom-ENEA-CREATE, DIMET, Universita degli Studi di Napoli (Italy); Villone, F. [Associazione Euratom-ENEA-CREATE, DIMET, Universita degli Studi di Cassino (Italy)

    2010-12-15

    In the framework of the ITER project, an investigation has been conducted on an alternative vessel and blanket design, aimed at reducing cost and production risk. The modifications proposed have a strong impact on plasma control since they affect the main conducting structures surrounding the plasma column, providing passive stabilization but at the same time shielding the field generated by the active coils to control the plasma motion and shape. An extensive analysis was performed to assess the plasma vertical controllability and the modified requirements to the in-vessel vertical stability coils system as well as to the external Poloidal Field coils system. A similar analysis was aimed at assessing the performance of the shape control system in presence of the modified structures. The effect on plasma breakdown was also evaluated in terms of maximum initial loop voltage, quality of magnetic null and the flux loss related to the breakdown delay that was quantified under the same hypothesis employed by ITER for the baseline design. Furthermore, the modified design presents issues for the magnetic diagnostic system, related to the shielding of the probes by the eddy currents, which were analysed with a 3D model. The results of the analyses performed have some general interest in particular regarding the influence on plasma stability of 3D structures with close proximity to the plasma. The present paper aims at giving an overview of the analyses that have been carried out and a summary of the results in terms of impact of the modified design on plasma control and scenario, and in general an evaluation of the role of passive structure in plasma vertical stability and shape control.

  19. Helium-cooled pebble bed test blanket module alternative design and fabrication routes

    International Nuclear Information System (INIS)

    Lux, M.

    2007-01-01

    According to first results of the recently started European DEMO study, a new blanket integration philosophy was developed applying so-called multi-module segments. These consist of a number of blanket modules flexibly mounted onto a common vertical manifold structure that can be used for replacing all modules in one segment at one time through vertical remote-handling ports. This principle gives new freedom in the design choices applied to the blanket modules itself. Based on the alternative design options considered for DEMO also the ITER test blanket module was newly analyzed. As a result of these activities it was decided to keep the major principles of the reference design like stiffening grid, breeder unit concept and perpendicular arrangement of pebble beds related to the First Wall because of the very positive results of thermo-mechanical and neutronics studies. The present paper gives an overview on possible further design optimization and alternative fabrication routes. One of the most significant improvements in terms of the hydraulic performance of the Helium cooled reactor can be reached with a new First Wall concept. That concept is based on an internal heat transfer enhancement technique and allows drastically reducing the flow velocity in the FW cooling channels. Small ribs perpendicular to the flow direction (transverse-rib roughness) are arranged on the inner surface of the First Wall cooling channels at the plasma side. In the breeder units cooling plates which are mostly parallel but bent into U-shape at the plasma-side are considered. In this design all flow channels are parallel and straight with the flow entering on one side of the parallel plate sections and exiting on the other side. The ceramic pebble beds are embedded between two pairs of such type of cooling plates. Different modifications could possibly be combined, whereby the most relevant discussed in this paper are (i) rib-cooled First Wall channels, (ii) U-bent cooling plates for

  20. Relationships between the functional PPARalpha Leu162Val polymorphism and obesity, type 2 diabetes, dyslipidaemia, and related quantitative traits in studies of 5799 middle-aged white people

    DEFF Research Database (Denmark)

    Sparsø, Thomas; Hussain, Meena S; Andersen, Gitte

    2007-01-01

    Peroxisome proliferator-activated receptor-alpha (PPARalpha) is a nuclear receptor capable of regulating the expression of genes involved in peroxisomal and mitochondrial beta-oxidation pathways. The common Leu162Val polymorphism in the gene encoding PPARalpha has inconsistently shown association...

  1. A Modified Jonckheere Test Statistic for Ordered Alternatives in Repeated Measures Design

    Directory of Open Access Journals (Sweden)

    Hatice Tül Kübra AKDUR

    2016-09-01

    Full Text Available In this article, a new test based on Jonckheere test [1] for  randomized blocks which have dependent observations within block is presented. A weighted sum for each block statistic rather than the unweighted sum proposed by Jonckheereis included. For Jonckheere type statistics, the main assumption is independency of observations within block. In the case of repeated measures design, the assumption of independence is violated. The weighted Jonckheere type statistic for the situation of dependence for different variance-covariance structure and the situation based on ordered alternative hypothesis structure of each block on the design is used. Also, the proposed statistic is compared to the existing test based on Jonckheere in terms of type I error rates by performing Monte Carlo simulation. For the strong correlations, circular bootstrap version of the proposed Jonckheere test provides lower rates of type I error.

  2. Analysis of the critical and first full power operating cores for PARR using leu oxide fuel

    International Nuclear Information System (INIS)

    Khan, L.A.; Qazi, M.K.; Bokhari, I.H.; Fazal, R.

    1989-10-01

    This paper explains the analysis for determining the first full power operating core for PARR using LEU oxide fuel. The core configuration selected for this first full power operation contains about 6.13 kg of U-235 distributed in 19 standard and five control fuel elements. The neutron flux level is doubled when core is shifted from 5MW to 10 MW. Total nuclear power peaking factor of the core is 2.03. The analysis shows that the core can be operated safely at 5 MW with a flow rate of 520 meter cube per hour and at 10 MW with a flow rate of 900 meter cube per hour. (A.B.). 10 figs

  3. Non-destructive evaluation of the cladding thickness in LEU fuel plates by accurate ultrasonic scanning technique

    Energy Technology Data Exchange (ETDEWEB)

    Borring, J.; Gundtoft, H.E.; Borum, K.K.; Toft, P. [Riso National Lab. (Denmark)

    1997-08-01

    In an effort to improve their ultrasonic scanning technique for accurate determination of the cladding thickness in LEU fuel plates, new equipment and modifications to the existing hardware and software have been tested and evaluated. The authors are now able to measure an aluminium thickness down to 0.25 mm instead of the previous 0.35 mm. Furthermore, they have shown how the measuring sensitivity can be improved from 0.03 mm to 0.01 mm. It has now become possible to check their standard fuel plates for DR3 against the minimum cladding thickness requirements non-destructively. Such measurements open the possibility for the acceptance of a thinner nominal cladding than normally used today.

  4. Non-destructive evaluation of the cladding thickness in LEU fuel plates by accurate ultrasonic scanning technique

    International Nuclear Information System (INIS)

    Borring, J.; Gundtoft, H.E.; Borum, K.K.; Toft, P.

    1997-01-01

    In an effort to improve their ultrasonic scanning technique for accurate determination of the cladding thickness in LEU fuel plates, new equipment and modifications to the existing hardware and software have been tested and evaluated. The authors are now able to measure an aluminium thickness down to 0.25 mm instead of the previous 0.35 mm. Furthermore, they have shown how the measuring sensitivity can be improved from 0.03 mm to 0.01 mm. It has now become possible to check their standard fuel plates for DR3 against the minimum cladding thickness requirements non-destructively. Such measurements open the possibility for the acceptance of a thinner nominal cladding than normally used today

  5. Assessment of alternative disposal concepts

    Energy Technology Data Exchange (ETDEWEB)

    Autio, J.; Saanio, T.; Tolppanen, P. [Saanio and Riekkola Consulting Engineers, Helsinki (Finland); Raiko, H.; Vieno, T. [VTT Energy, Espoo (Finland); Salo, J.P. [Posiva Oy, Helsinki (Finland)

    1996-12-01

    Four alternative repository designs for the disposal of spent nuclear in the Finnish crystalline bedrock were assessed in the study. The alternatives were: (1) the basic KBS-3 design in which copper canisters are emplaced in vertical deposition holes bored in the floors of horizontal tunnels, (2) the KBS-3-2C design with two canisters in a deposition hole, (3) Short Horizontal Holes (SHH) in the side walls of the tunnels, and (4) the Medium Long Holes (MLH) concept in which approximately 25 canisters are emplaced in a horizontal deposition hole about 200 metres in length bored between central and side tunnels. In all the alternatives considered, the thickness of the layer of compacted bentonite between copper canister and bedrock is 35 cm. Two different copper canister designs were also assessed. Technical feasibility and flexibility, post-closure safety and repository cost were assessed for each of the alternative canister and repository designs. On the basis of this assessment it is recommended that further development and studies should focus on the vacuum- or inert gas-filled cast insert type copper canister and the basic KBS-3 type repository design with a single canister in a vertical deposition hole. The KBS-3 design is robust and flexible and provides excellent post-closure safety. The transfer, emplacement and sealing operations are technically uncomplicated. The alternative options assessed do not offer any significant benefits in safety or cost over the basic design, but they are technically more complex and also in some respects more vulnerable to malfunction during the emplacement of canisters and buffer, as well as common mode failures. (60 refs.).

  6. Assessment of alternative disposal concepts

    International Nuclear Information System (INIS)

    Autio, J.; Saanio, T.; Tolppanen, P.; Raiko, H.; Vieno, T.; Salo, J.P.

    1996-12-01

    Four alternative repository designs for the disposal of spent nuclear in the Finnish crystalline bedrock were assessed in the study. The alternatives were: (1) the basic KBS-3 design in which copper canisters are emplaced in vertical deposition holes bored in the floors of horizontal tunnels, (2) the KBS-3-2C design with two canisters in a deposition hole, (3) Short Horizontal Holes (SHH) in the side walls of the tunnels, and (4) the Medium Long Holes (MLH) concept in which approximately 25 canisters are emplaced in a horizontal deposition hole about 200 metres in length bored between central and side tunnels. In all the alternatives considered, the thickness of the layer of compacted bentonite between copper canister and bedrock is 35 cm. Two different copper canister designs were also assessed. Technical feasibility and flexibility, post-closure safety and repository cost were assessed for each of the alternative canister and repository designs. On the basis of this assessment it is recommended that further development and studies should focus on the vacuum- or inert gas-filled cast insert type copper canister and the basic KBS-3 type repository design with a single canister in a vertical deposition hole. The KBS-3 design is robust and flexible and provides excellent post-closure safety. The transfer, emplacement and sealing operations are technically uncomplicated. The alternative options assessed do not offer any significant benefits in safety or cost over the basic design, but they are technically more complex and also in some respects more vulnerable to malfunction during the emplacement of canisters and buffer, as well as common mode failures. (60 refs.)

  7. Treating Youths with Selective Mutism with an Alternating Design of Exposure-Based Practice and Contingency Management

    Science.gov (United States)

    Vecchio, Jennifer; Kearney, Christopher A.

    2009-01-01

    Selective mutism is a severe childhood disorder involving failure to speak in public situations in which speaking is expected. The present study examined 9 youths with selective mutism treated with child-focused, exposure-based practices and parent-focused contingency management via an alternating treatments design. Broadband measures of…

  8. Alternative pavement designs : Randolph park and ride.

    Science.gov (United States)

    2013-05-01

    Previous research on alternative pavement type bidding has proven that various treatments : are unique in terms of constructability, material characteristics, and associated performance. : While some treatments may have higher initial costs, it is im...

  9. Mutations Phe785Leu and Thr618Met in Na+, K+-ATPase, Associated with Familial Rapid-Onset Dystonia Parkinsonism, Interfere with Na+ Interaction by Distinct Mechanisms

    DEFF Research Database (Denmark)

    Schack, Vivien Rodacker; Toustrup-Jensen, Mads Schak; Vilsen, Bente

    The Na+, K+-ATPase plays key roles in brain function. Recently, missense mutations in the Na+, K+-ATPase were found associated with familial rapid-onset dystonia parkinsonism (FRDP). Here, we have characterized the functional consequences of FRDP mutations Phe785Leu and Thr618Met. Both mutations...... lead to functionally altered, but active, Na+, K+-pumps that display reduced apparent affinity for cytoplasmic Na+, but the underlying mechanism differs between the mutants. In Phe785Leu, the interaction of the E1 form with Na+ is defective, and the E1-E2 equilibrium is not displaced. In Thr618Met......, the Na+ affinity is reduced because of displacement of the conformational equilibrium in favor of the K+-occluded E2(K2) form. In both mutants, K+ interaction at the external activating sites of the E2P phosphoenzyme is normal. The change of cellular Na+ homeostasis is likely a major factor contributing...

  10. Mutations Phe785Leu and Thr618Met in Na+, K+-ATPase, Associated with Familial Rapid-Onset Dystonia Parkinsonism, Interfere with Na+ Interaction by Distinct Mechanisms

    DEFF Research Database (Denmark)

    Schack, Vivien Rodacker; Toustrup-Jensen, Mads Schak; Vilsen, Bente

    The Na+, K+-ATPase plays key roles in brain function. Recently, missense mutations in the Na+, K+-ATPase were found associated with familial rapid-onset dystonia parkinsonism (FRDP). We have characterized the functional consequences of FRDP mutations Phe785Leu and Thr618Met. Both mutations lead...... to functionally altered, but active, Na+, K+-pumps that display reduced apparent affinity for cytoplasmic Na+, but the underlying mechanism differs between the mutants. In Phe785Leu, the interaction of the E1 form with Na+ is defective, and the E1-E2 equilibrium is not displaced. In Thr618Met, the Na+ affinity...... is reduced because of displacement of the conformational equilibrium in favor of the K+-occluded E2(K2) form. In both mutants, K+ interaction at the external activating sites of the E2P phosphoenzyme is normal. The change of cellular Na+ homeostasis is likely a major factor contributing to the development...

  11. The status of HEU and LEU core conversion activities at the Jamaica SLOWPOKE

    Energy Technology Data Exchange (ETDEWEB)

    Preston, J.; Grant, C., E-mail: john.preston@uwimona.edu.jm [Univ. of the West Indies, Mona Campus, International Centre for Environmental and Nuclear Sciences, Kingston (Jamaica)

    2013-07-01

    The SLOWPOKE reactor in Jamaica has been operated by the International Centre for Environmental and Nuclear Sciences, University of the West Indies since 1984, mainly for the purpose of Neutron Activation Analysis. The HEU core with current utilization has another 14 years of operation, before the addition of a large beryllium annulus would be required to further extend the life-time by 15 years. However, in keeping with the spirit of the Reduced Enrichment for Research and Test Reactors (RERTR) program, the decision was taken in 2003 to convert the core from HEU to LEU, inline with those at the Ecole Polytechnic and RMC SLOWPOKE facilities. This paper reports on the current status of the conversion activities, including key fuel manufacture and regulatory issues, which have seen substantial progress during the last year. A timetable for the complete process is given, and provided that the fuel fabrication can be completed in the estimated 18 months, the core conversion should be accomplished by the end of 2014. (author)

  12. RERTR program activities related to the development and application of new LEU fuels

    International Nuclear Information System (INIS)

    Travelli, A.

    1983-01-01

    The statue of the U.S. Reduced Enrichment Research and Test Reactor (RERTR) Program is reviewed. After a brief outline of RERTR Program objectives and goals, program accomplishments are discussed with emphasis on the development, demonstration and application of new LEU fuels. Most program activities have proceeded as planned, and a combination of two silicide fuels (U 3 Si 2 -Al and U 3 Si-Al) holds excellent promise for achieving the long-term program goals. Current plans and schedules project the uranium density of qualified RERTR fuels for plate-type reactors to grow by approximately 1 g U/cm 3 each year, from the current 1.7 g U/cm 3 to the 7.0 g U/cm 3 which will be reached in late 1988. The technical needs of research and test reactors for HEU exports are also forecasted to undergo a gradual but dramatic decline in the coming years

  13. A virtual high-throughput screening approach to the discovery of novel inhibitors of the bacterial leucine transporter, LeuT

    DEFF Research Database (Denmark)

    Simmons, Katie J; Gotfryd, Kamil; Billesbølle, Christian B

    2013-01-01

    Abstract Membrane proteins are intrinsically involved in both human and pathogen physiology, and are the target of 60% of all marketed drugs. During the past decade, advances in the studies of membrane proteins using X-ray crystallography, electron microscopy and NMR-based techniques led to the e...... this is a virtual high-throughput screening (vHTS) technique initially developed for soluble proteins. This paper describes application of this technique to the discovery of inhibitors of the leucine transporter (LeuT), a member of the neurotransmitter:sodium symporter (NSS) family....

  14. Alternatives for implementing burnup credit in the design and operation of spent fuel transport casks

    International Nuclear Information System (INIS)

    Sanders, T.L.; Lake, W.H.

    1989-01-01

    It is possible to develop an optimal strategy for implementing burnup credit in spent fuel transport casks. For transport, the relative risk is rapidly reduced if additional pre-transport controls such as a cavity dryness verifications are conducted prior to transport. Some other operational and design features that could be incorporated into a burnup credit cask strategy are listed. These examples represent many of the system features and alternatives already available for use in developing a broadly based criticality safety strategy for implementing burnup credit in the design and operation of spent fuel transport casks. 4 refs., 1 tab

  15. The Political Construction of Alternative Dispute Resolution and Alternatives to Incarceration.

    Science.gov (United States)

    Palumbo, Dennis J.; And Others

    1994-01-01

    This discussion of evaluations of mediation programs at seven sites and of shock incarceration and home arrest focuses on the similarities in the interpretations of alternative dispute-resolution programs to interpretations of alternatives to incarceration programs. The political construction of the two approaches, which are both designed to…

  16. Design Study for a Low-Enriched Uranium Core for the High Flux Isotope Reactor, Annual Report for FY 2008

    Energy Technology Data Exchange (ETDEWEB)

    Primm, Trent [ORNL; Chandler, David [ORNL; Ilas, Germina [ORNL; Miller, James Henry [ORNL; Sease, John D [ORNL; Jolly, Brian C [ORNL

    2009-03-01

    This report documents progress made during FY 2008 in studies of converting the High Flux Isotope Reactor (HFIR) from highly enriched uranium (HEU) fuel to low-enriched uranium (LEU) fuel. Conversion from HEU to LEU will require a change in fuel form from uranium oxide to a uranium-molybdenum alloy. With axial and radial grading of the fuel foil and an increase in reactor power to 100 MW, calculations indicate that the HFIR can be operated with LEU fuel with no degradation in reactor performance from the current level. Results of selected benchmark studies imply that calculations of LEU performance are accurate. Scoping experiments with various manufacturing methods for forming the LEU alloy profile are presented.

  17. Optimum nuclear design of target fuel rod for Mo-99 production in HANARO

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Myung Hyun [Kyung Hee University, Seoul (Korea)

    1998-04-01

    Nuclear target design for Mo-99 production in HANARO was performed, KAERI proposed target design was analyzed and its feasibility was shown. Three commercial target designs of Cintichem, ANL and KAERI were tested for the HANARO irradiation an d they all satisfied with design specification. A parametric study was done for target design options and Mo-99 yields ratio and surface heat flux were compared. Tested parameters were target fuel thickness, irradiation location, target axial length, packing density of powder fuel, size of target radius, target geometry, fuel enrichment, fuel composition, and cladding material. Optimized target fuel was designed for both LEU and HEU options. (author). 17 refs., 33 figs., 42 tabs.

  18. US Progress on Property Characterization to Support LEU U-10 Mo Monolithic Fuel Development

    Energy Technology Data Exchange (ETDEWEB)

    Cole, James Irvin [Idaho National Laboratory; Rabin, Barry H [Idaho National Laboratory; Smith, James Arthur [Idaho National Laboratory; Scott, Clark Landon [Idaho National Laboratory; Benefiel, Bradley Curtis [Idaho National Laboratory; Larsen, Eric David [Idaho National Laboratory; Lind, Robert Paul [Idaho National Laboratory; Sell, David Alan [Idaho National Laboratory

    2016-03-01

    The US High Performance Research Reactor program is pursuing development and qualification of a new high density monolithic LEU fuel to facilitate conversion of five higher power research reactors located in the US (ATR, HFIR, NBSR, MIT and MURR). In order to support fabrication development and fuel performance evaluations, new testing capabilities are being developed to evaluate the properties of fuel specimens. Residual stress and fuel-cladding bond strength are two characteristics related to fuel performance that are being investigated. In this overview, new measurement capabilities being developed to assess these characteristics in both fresh and irradiated fuel are described. Progress on fresh fuel testing is summarized and on-going hot-cell implementation efforts to support future PIE campaigns are detailed. It is anticipated that benchmarking of as-fabricated fuel characteristics will be critical to establishing technical bases for specifications that optimize fuel fabrication and ensure acceptable in-reactor fuel performance.

  19. HEU to LEU conversion and blending facility: Oxide blending alternative to produce LEU oxide for commercial use

    International Nuclear Information System (INIS)

    1995-09-01

    The United States Department of Energy (DOE) is examining options for the disposition of surplus weapons-usable fissile materials and storage of all weapons-usable fissile materials. Disposition is a process of use or disposal of material that results in the material being converted to a form that is substantially and inherently more proliferation-resistant than the original form. Examining options for increasing the proliferation resistance of highly enriched uranium (HEU) is part of this effort. This document provides data to be used in the environmental impact analysis for the oxide blending HEU disposition option. This option provides for a yearly HEU throughput of 1 0 metric tons (MT) of uranium metal with an average U235 assay of 50% blended with 165 MT of natural assay triuranium octoxide (U 3 O 8 ) per year to produce 177 MT of 4% U235 assay U 3 O 8 , for LWR fuel. Since HEU exists in a variety of forms and not necessarily in the form to be blended, worst case scenarios for preprocessing prior to blending will be assumed for HEU feed streams

  20. HEU to LEU Conversion and Blending Facility: UNH blending alternative to produce LEU UNH for commercial use

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-09-01

    US DOE is examining options for disposing of surplus weapons-usable fissile materials and storage of all weapons-usable fissile materials. The nuclear material is converted to a form that is more proliferation-resistant than the original form. Examining options for increasing the proliferation resistance of highly enriched uranium (HEU) is part of this effort. Five technologies for blending HEU will be assessed. This document provides data to be used in the environmental impact analysis for the UNH blending HEU disposition option. Process requirements, resource needs, employment needs, waste/emissions from plant, hazards, accident scenarios, and intersite transportation are discussed.

  1. HEU to LEU conversion and blending facility: Oxide blending alternative to produce LEU oxide for commercial use

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-09-01

    The United States Department of Energy (DOE) is examining options for the disposition of surplus weapons-usable fissile materials and storage of all weapons-usable fissile materials. Disposition is a process of use or disposal of material that results in the material being converted to a form that is substantially and inherently more proliferation-resistant than the original form. Examining options for increasing the proliferation resistance of highly enriched uranium (HEU) is part of this effort. This document provides data to be used in the environmental impact analysis for the oxide blending HEU disposition option. This option provides for a yearly HEU throughput of 1 0 metric tons (MT) of uranium metal with an average U235 assay of 50% blended with 165 MT of natural assay triuranium octoxide (U{sub 3} O{sub 8}) per year to produce 177 MT of 4% U235 assay U{sub 3} O{sub 8}, for LWR fuel. Since HEU exists in a variety of forms and not necessarily in the form to be blended, worst case scenarios for preprocessing prior to blending will be assumed for HEU feed streams.

  2. Scalability of the LEU-Modified Cintichem Process: 3-MeV Van de Graaff and 35-MeV Electron Linear Accelerator Studies

    Energy Technology Data Exchange (ETDEWEB)

    Rotsch, David A. [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Brossard, Tom [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Roussin, Ethan [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Quigley, Kevin [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Chemerisov, Sergey [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Gromov, Roman [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Jonah, Charles [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Hafenrichter, Lohman [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Tkac, Peter [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Krebs, John [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Vandegrift, George F. [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division

    2016-10-31

    Molybdenum-99, the mother of Tc-99m, can be produced from fission of U-235 in nuclear reactors and purified from fission products by the Cintichem process, later modified for low-enriched uranium (LEU) targets. The key step in this process is the precipitation of Mo with α-benzoin oxime (ABO). The stability of this complex to radiation has been examined. Molybdenum-ABO was irradiated with 3 MeV electrons produced by a Van de Graaff generator and 35 MeV electrons produced by a 50 MeV/25 kW electron linear accelerator. Dose equivalents of 1.7–31.2 kCi of Mo-99 were administered to freshly prepared Mo-ABO. Irradiated samples of Mo-ABO were processed according to the LEU Modified-Cintichem process. The Van de Graaff data indicated good radiation stability of the Mo-ABO complex up to ~15 kCi dose equivalents of Mo-99 and nearly complete destruction at doses >24 kCi Mo-99. The linear accelerator data indicate that even at 6.2 kCi of Mo-99 equivalence of dose, the sample lost ~20% of Mo-99. The 20% loss of Mo-99 at this low dose may be attributed to thermal decomposition of the product from the heat deposited in the sample during irradiation.

  3. Mechanical Design of an Alternate Structure for LARP Nb$_{3}$Sn Quadrupole Magnets for LHC

    CERN Document Server

    Anerella, M; Kovach, P; Schmalzle, J; Wanderer, P; Ambrosio, G; Lamm, M J; Caspi, S; Felice, H; Ferracin, P; Sabbi, G L

    2011-01-01

    An alternative structure for the 120 mm Nb$_{3}$Sn quadrupole magnet is presently under development for use in the upgrade for LHC at CERN. The design aims to build existing technology developed in LARP with the LQ and HQ magnets and to further optimize the features required for operation in the accelerator. The structure includes features for maintaining mechanical alignment of the coils to achieve the required field quality. It also includes a helium containment vessel and provisions for cooling with 1.9 K helium. The development effort includes the assembly of a six inch model to verify required coil load is achieved. Status of the R&D effort and an update on the magnet design, including its incorporation into the design of a complete one meter cold mass is presented.

  4. Leu7Pro polymorphism of PreproNPY associated with an increased risk for type II diabetes in middle-aged subjects.

    Science.gov (United States)

    Ukkola, O; Kesäniemi, Y A

    2007-09-01

    Neuropeptide Y (NPY) plays a central in energy homeostasis and potentially in the development of obesity-related comorbidities, like type II diabetes. As the PreproNPY Leu7Pro polymorphism probably changes the intracellular processing of the synthesized preproNPY peptide, we assessed the hypothesis that PreproNPY Leu7Pro polymorphism is a risk factor for type II diabetes, impaired glucose tolerance and hypertension. Blood pressure recordings and oral glucose tolerance test were performed in the hypertensive (n=515) and control cohorts (n=525) of our well-defined Oulu Project Elucidating Risk of Atherosclerosis (OPERA) study. The prevalence of type II diabetes was 9% (n=93). The genotypes, insulin and glucose metabolism indexes and plasma ghrelin of the subjects were determined. Pro7 allele frequencies were 5.9, 5.3 and 11.3% in the total cohort, in subjects without and with type II diabetes, respectively. The PreproNPY Pro7 carrier status was a significant risk factor for type II diabetes, and the effect remained significant after adjustment for age, sex, waist circumference and study group (odds ratio=3.02, confidence interval: 1.67-5.44 and Pghrelin levels compared to non-carriers. The PreproNPY Pro7 allele is associated with an increased risk for type II diabetes. The risk seems to be associated with a higher insulin resistance among Pro7 carriers whereas low ghrelin concentrations in Pro7 carriers are possibly a consequence of high insulin levels.

  5. Randomized controlled trials and neuro-oncology: should alternative designs be considered?

    Science.gov (United States)

    Mansouri, Alireza; Shin, Samuel; Cooper, Benjamin; Srivastava, Archita; Bhandari, Mohit; Kondziolka, Douglas

    2015-09-01

    quality of design/reporting of RCTs in neuro-oncology persist. Quality improvement is necessary. Consideration of alternative strategies should be considered.

  6. Implementation of a Gadolinium Burnable Absorber in the Carbide LEU-NTR

    International Nuclear Information System (INIS)

    Venneria, Paolo; Kim, Yonghee

    2015-01-01

    Among the most crucial are the rapid reactivity depletion during full-power operation and the positive reactivity insertion during the full-submersion criticality accident. In previous work, it has been suggested that both challenges can be mitigated through the successful implementation of a burnable absorber in the active core. Of the poisons previously surveyed, one of the most promising is Gadolinium in the form of Gadolina (Gd2O4). This paper explores the possibility of different methods by which the Gadolinia can be implemented in the core and makes a preliminary study of its effect on the full submersion criticality accident and the reactivity depletion during operation. The application of a Gadolinium neutron absorber in the active core region of the LEU-NTR has been shown to be neutronically feasible. It can be introduced into the core in various locations without resulting in core performance loss. The utility of the poison in terms of mitigating the full-submersion reactivity accident and the rapid change in reactivity during full-power operation have been preliminarily shown and the first steps towards eventual implementation made. Future work will consist of determining the maximum poison content in the core and tailoring the self-shielding effect in order to determine a specific Gd depletion rate

  7. Selection of fuel design for conversion and upgradation of Pakistan Research Reactor (PARR-1)

    International Nuclear Information System (INIS)

    Arshad, M.

    1991-01-01

    The Pakistan Research Reactor (PARR-1) is being converted from the use of Highly Enriched Uranium (HEU) to Low Enriched Uranium (LEU) fuel and its power is also being upgraded. In order to select new fuel for the converted and upgraded core ten different fuel element designs were analyzed and their relative performance was compared. Results of this study were later used to select appropriate design of the new fuel for PARR-1. This paper describes the computational methodology utilized for the analysis of various fuel element designs. Criteria for selecting the new fuel element are discussed and guidelines forming the selection basis of the new fuel design are given. (author)

  8. Design and first measurements of an alternative calorimetry chamber for the HZB quadrupole resonator

    CERN Document Server

    Keckert, Sebastian; Knobloch, Jens; Kugeler, Oliver

    2015-01-01

    The systematic research on superconducting thin films requires dedicated testing equipment. The Quadrupole Resonator (QPR) is a specialized tool to characterize the superconducting RF properties of circular planar samples. A calorimetric measurement of the RF surface losses allows the surface resistance to be measured with sub nano-ohm resolution. This measurement can be performed over a wide temperature and magnetic field range, at frequencies of 433, 866 and 1300 MHz. The system at Helmholtz-Zentrum Berlin (HZB) is based on a resonator built at CERN and has been optimized to lower peak electric fields and an improved resolution. In this paper the design of an alternative calorimetry chamber is presented, providing flat samples for coating which are easy changeable. All parts are connected by screwing connections and no electron beam welding is required. Furthermore this design enables exchangeability of samples between the resonators at HZB and CERN. First measurements with the new design show ambiguous r...

  9. [D-Arg1,D-Phe5,D-Trp7,9,Leu11]substance P, a potent bombesin antagonist in murine Swiss 3T3 cells, inhibits the growth of human small cell lung cancer cells in vitro.

    OpenAIRE

    Woll, P J; Rozengurt, E

    1988-01-01

    In the search for a more potent bombesin antagonist, we found [D-Arg1,D-Phe5,D-Trp7,9,Leu11]substance P to be effective in mouse fibroblasts and to inhibit the growth of small cell lung cancer, a tumor that secretes bombesin-like peptides that may act as autocrine growth factors. In murine Swiss 3T3 cells, [D-Arg1,D-Phe5,D-Trp7,9,Leu11]substance P proved to be a bombesin antagonist as judged by the following criteria: (i) inhibition of DNA synthesis induced by gastrin-releasing peptide and ot...

  10. LEU-plate irradiation at FRJ-2 (DIDO) under the German AF-programme

    Energy Technology Data Exchange (ETDEWEB)

    Groos, E; Krug, W; Seferiadis, J; Thamm, G

    1985-07-01

    10 LEU fuel plates (8 with uranium silicides max. U-density 6.1 g/cm{sup 3}) have been irradiated at FRJ-2 (DIDO) of KFA-Juelich till end of October 1984 during 321 full power days up to max. burnup of 2.41x10{sup 27} fissions/m{sup 3} without major interruptions and troubles. PIE began recently in KFA hot cells. Visual inspections revealed no damage or greater deformation for the majority of the plates, but red/brown coloured layers (partially peeled off) on the cladding over the fuel. Aluminium (oxide) is the chief constituent of the layer with smaller portions of Ni and Fe the latter causing the red/brown colour. The major part of the layer ({approx}50 {mu}m) most probably has been formed during 20 h immediately after experiment start-up under abnormal conditions of the coolant water. Gamma scanning has been completed. Dimensional measurements are under way confirming first observations of severe swelling (pillowing) of 1 plate. Density and blister testing as well as metallography and burnup analysis remain to be accomplished end of 1985/beginning of 1986. (author)

  11. The status of HEU to LEU core conversion activities at the Jamaica SLOWPOKE

    Energy Technology Data Exchange (ETDEWEB)

    Preston, J.; Grant, C., E-mail: john.preston@uwimona.edu.jm [Univ. of the West Indies, Mona Campus, International Centre for Environmental and Nuclear Sciences, Mona (Jamaica)

    2012-12-15

    The SLOWPOKE reactor in Jamaica has been operated by the International Centre for Environmental and Nuclear Sciences, University of the West Indies since 1984, mainly for the purpose of Neutron Activation Analysis. The HEU core with current utilization has another 14 years of operation, before the addition of a large beryllium annulus would be required to further extend the life-time by 15 years. However, in keeping with the spirit of the Reduced Enrichment for Research and Test Reactors (RERTR) program, the decision was taken in 2003 to convert the core from HEU to LEU, in line with those at the Ecole Polytechnic and RMC SLOWPOKE facilities. This paper reports on the current status of the conversion activities, including key fuel manufacture and regulatory issues, which have seen substantial progress during the last year. A timetable for the complete process is given, and provided that the fuel fabrication can be completed in the estimated 18 months, the core conversion should be accomplished by the end of 2014. (author)

  12. TOLL-LIKE RECEPTOR 7 GENE Gln11Leu MISSENSEMUTATION AND SUSCEPTIBILITY TO PSORIASIS

    Directory of Open Access Journals (Sweden)

    E. S. Galimova

    2017-01-01

    Full Text Available Toll-like receptor (TLR are responsible for recognizing various molecular patterns associated with pathogens. Their expression have been detected in skin cells such as keratinocytes and melanocytes. Numerous experimental studies demonstrate the key role of TLRs in the pathogenesis of immune diseases, including psoriasis. The objective of this study is to analyze the associations of polymorphisms in TLR7 gene and the risk of psoriasis development. DNA samples were collected from 138 patients with psoriasis and 317 healthy controls. Genotyping of rs179003, rs179008, rs179020, rs850632, rs12013728 polymorphic loci in TLR7 gene was performed using the SNPlex™method (AB, USA. SNP in the TLR7 gene rs179008 (Gln11Leu was associated with psoriasis in entire psoriasis, late onset and sporadic subgroups (Рс = 0.0065, OR = 1.95; Рс = 0.0004, OR = 2.50; Рс = 0.0078, OR = 2.2, respectively. In conclusion, this study is the first to identify genetic variants of the TLR7 gene significantly associated with psoriasis. 

  13. TOLL-LIKE RECEPTOR 7 GENE Gln11Leu MISSENSEMUTATION AND SUSCEPTIBILITY TO PSORIASIS

    Directory of Open Access Journals (Sweden)

    E. S. Galimova

    2017-01-01

    Full Text Available Toll-like receptor (TLR are responsible for recognizing various molecular patterns associated with pathogens. Their expression have been detected in skin cells such as keratinocytes and melanocytes. Numerous experimental studies demonstrate the key role of TLRs in the pathogenesis of immune diseases, including psoriasis. The objective of this study is to analyze the associations of polymorphisms in TLR7 gene and the risk of psoriasis development. DNA samples were collected from 138 patients with psoriasis and 317 healthy controls. Genotyping of rs179003, rs179008, rs179020, rs850632, rs12013728 polymorphic loci in TLR7 gene was performed using the SNPlex™method (AB, USA. SNP in the TLR7 gene rs179008 (Gln11Leu was associated with psoriasis in entire psoriasis, late onset and sporadic subgroups (Рс = 0.0065, OR = 1.95; Рс = 0.0004, OR = 2.50; Рс = 0.0078, OR = 2.2, respectively. In conclusion, this study is the first to identify genetic variants of the TLR7 gene significantly associated with psoriasis.

  14. Alternatives for Jet Engine Control. Volume 1: Modelling and Control Design with Jet Engine Data

    Science.gov (United States)

    Sain, M. K.

    1985-01-01

    This document compiles a comprehensive list of publications supported by, or related to, National Aeronautics and Space Administration Grant NSG-3048, entitled "Alternatives for Jet Engine Control". Dr. Kurt Seldner was the original Technical Officer for the grant, at Lewis Research Center. Dr. Bruce Lehtinen was the final Technical Officer. At the University of Notre Dame, Drs. Michael K. Sain and R. Jeffrey Leake were the original Project Directors, with Dr. Sain becoming the final Project Director. Publications cover work over a ten-year period. The Final Report is divided into two parts. Volume i, "Modelling and Control Design with Jet Engine Data", follows in this report. Volume 2, "Modelling and Control Design with Tensors", has been bound separately.

  15. Preliminary Assessment of Two Alternative Core Design Concepts for the Special Purpose Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Sterbentz, James W. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Werner, James E. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Hummel, Andrew J. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Kennedy, John C. [Idaho National Lab. (INL), Idaho Falls, ID (United States); O' Brien, Robert C. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Dion, Axel M. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Wright, Richard N. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Ananth, Krishnan P. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2017-11-01

    The Special Purpose Reactor (SPR) is a small 5 MWt, heat pipe-cooled, fast reactor based on the Los Alamos National Laboratory (LANL) Mega-Power concept. The LANL concept features a stainless steel monolithic core structure with drilled channels for UO2 pellet stacks and evaporator sections of the heat pipes. Two alternative active core designs are presented here that replace the monolithic core structure with simpler and easier to manufacture fuel elements. The two new core designs are simply referred to as Design A and Design B. In addition to ease of manufacturability, the fuel elements for both Design A and Design B can be individually fabricated, assembled, inspected, tested, and qualified prior to their installation into the reactor core leading to greater reactor system reliability and safety. Design A fuel elements will require the development of a new hexagonally-shaped UO2 fuel pellet. The Design A configuration will consist of an array of hexagonally-shaped fuel elements with each fuel element having a central heat pipe. This hexagonal fuel element configuration results in four radial gaps or thermal resistances per element. Neither the fuel element development, nor the radial gap issue are deemed to be serious and should not impact an aggressive reactor deployment schedule. Design B uses embedded arrays of heat pipes and fuel pins in a double-wall tank filled with liquid metal sodium. Sodium is used to thermally bond the heat pipes to the fuel pins, but its usage may create reactor transportation and regulatory challenges. An independent panel of U.S. manufacturing experts has preliminarily assessed the three SPR core designs and views Design A as simplest to manufacture. Herein are the results of a preliminary neutronic, thermal, mechanical, material, and manufacturing assessment of both Design A and Design B along with comparisons to the LANL concept (monolithic core structure). Despite the active core differences, all three reactor concepts behave

  16. The Val{sup 192}Leu mutation in the {alpha}-subunit of {beta}-hexosaminidase A is not associated with the B1-variant form of Tay-Sachs disease

    Energy Technology Data Exchange (ETDEWEB)

    Hou, Y.; Vavougios, G.; Hinek, A. [Univ. of Toronto (Canada)] [and others

    1996-07-01

    Substitution mutations adversely affecting the {alpha}-subunit of {beta}-hexosaminidase A ({alpha}{beta}) (EC 3.2.1.52) result in Tay-Sachs disease. The majority affect the initial folding of the pro-{alpha} chain in the endoplasmic reticulum, resulting in its retention and degradation. A much less common occurrence is a mutation that specifically affects an {open_quotes}active-site{close_quotes} residue necessary for substrate binding and/or catalysis. In this case, hexosaminidase A is present in the lysosome, but it lacks all {alpha}-specific activity. This biochemical phenotype is referred to as the {open_quotes}B1-variant form{close_quotes} of Tay-Sachs disease. Kinetic analysis of suspected B1-variant mutations is complex because hexosaminidase A is heterodimeric and both subunits possess similar active sites. In this report, we examine a previously identified B1-variant mutation, {alpha}-Val{sup 192}Leu. Chinese hamster ovary cells were permanently cotransfected with an {alpha}-cDNA-construct encoding the substitution and a mutant {beta}-cDNA ({beta}-Arg{sup 211}Lys), encoding a {beta}-subunit that is inactive but normal in all other respects. We were surprised to find that the Val{sup 192}Leu substitution produced a pro-{alpha} chain that did not form {alpha}-{beta} dimers and was not transported to the lysosome. Finally, we reexamined the hexosaminidase activity and protein levels in the fibroblasts from the original patient. These data were also not consistent with the biochemical phenotype of the B1 variant of Tay-Sachs disease previously reported to be present. Thus, we conclude that the Val{sup 192}Leu substitution does not specifically affect the {alpha}-active site. 23 refs., 4 figs., 2 tabs.

  17. RHF RELAP5 model and preliminary loss-of-offsite-power simulation results for LEU conversion

    Energy Technology Data Exchange (ETDEWEB)

    Licht, J. R. [Argonne National Laboratory (ANL), Argonne, IL (United States). Nuclear Engineering Div.; Bergeron, A. [Argonne National Laboratory (ANL), Argonne, IL (United States). Nuclear Engineering Div.; Dionne, B. [Argonne National Laboratory (ANL), Argonne, IL (United States). Nuclear Engineering Div.; Thomas, F. [Institut Laue-Langevin (ILL), Grenoble (Switzerland). RHF Reactor Dept.

    2014-08-01

    The purpose of this document is to describe the current state of the RELAP5 model for the Institut Laue-Langevin High Flux Reactor (RHF) located in Grenoble, France, and provide an update to the key information required to complete, for example, simulations for a loss of offsite power (LOOP) accident. A previous status report identified a list of 22 items to be resolved in order to complete the RELAP5 model. Most of these items have been resolved by ANL and the RHF team. Enough information was available to perform preliminary safety analyses and define the key items that are still required. Section 2 of this document describes the RELAP5 model of RHF. The final part of this section briefly summarizes previous model issues and resolutions. Section 3 of this document describes preliminary LOOP simulations for both HEU and LEU fuel at beginning of cycle conditions.

  18. Analysis of the loss of coolant accident for LEU cores of Pakistan research reactor-1

    International Nuclear Information System (INIS)

    Khan, L.A.; Bokhari, I.H.; Raza, S.H.

    1993-12-01

    Response of LEU cores for PARR-1 to a Loss of Coolant Accident (LOCA) has been studied. It has been assumed that pool water drains out to double ended rupture of primary coolant pipe or complete shearing of an experimental beam tube. Results show that for an operating power level of 10 MW, both the first high power and equilibrium cores would enter into melting conditions if the pool drain time is less than 22 h and 11 h respectively. However, an Emergency Core Cooling System (ECCS) capable of spraying the core at flow rate of 8.3 m/sup 3/h, for the above mentioned duration, would keep the peak core temperature much below the critical value. Maximum operating power levels below which melting would not occur have been assessed to 3.4 MW and 4.8 MW, respectively, for the first high power and equilibrium cores. (author) 5 figs

  19. Parametric Optimization of Some Critical Operating System Functions--An Alternative Approach to the Study of Operating Systems Design

    Science.gov (United States)

    Sobh, Tarek M.; Tibrewal, Abhilasha

    2006-01-01

    Operating systems theory primarily concentrates on the optimal use of computing resources. This paper presents an alternative approach to teaching and studying operating systems design and concepts by way of parametrically optimizing critical operating system functions. Detailed examples of two critical operating systems functions using the…

  20. Towards for Analyzing Alternatives of Interaction Design Based on Verbal Decision Analysis of User Experience

    Directory of Open Access Journals (Sweden)

    Marília Soares Mendes

    2010-04-01

    Full Text Available In domains (as digital TV, smart home, and tangible interfaces that represent a new paradigm of interactivity, the decision of the most appropriate interaction design solution is a challenge. HCI researchers have promoted in their works the validation of design alternative solutions with users before producing the final solution. User experience with technology is a subject that has also gained ground in these works in order to analyze the appropriate solution(s. Following this concept, a study was accomplished under the objective of finding a better interaction solution for an application of mobile TV. Three executable applications of mobile TV prototypes were built. A Verbal Decision Analysis model was applied on the investigations for the favorite characteristics in each prototype based on the user’s experience and their intentions of use. This model led a performance of a qualitative analysis which objectified the design of a new prototype.

  1. The U.S. RERTR program status and progress

    International Nuclear Information System (INIS)

    Travelli, A.

    1998-01-01

    The progress of the Reduced Enrichment Research and Test Reactor (RERTR) Program since its inception in 1978 is described. A brief summary of the results which the RERTR Program had achieved by the end of 1996 in collaboration with its many international partners is followed by a detailed review of the major events, findings, and activities of 1997. Significant progress has been made during the past year. In the area of U.S. acceptance of spent fuel from foreign research reactors, several shipments have taken place and additional are being planned. Intense fuel development activities are in progress, including procurement of equipment, screening of candidate materials, and production of microplates. Irradiation of the first series of microplates began in August 1997 in the Advanced Test Reactor, in Idaho. Progress has been made in the Russian RERTR program, which aims to develop and demonstrate within five years the technical means needed to convert Russian-supplied research reactors to LEU fuels. The study of an alternative LEU core for the FRM-II design has been extended to address, with favorable results, controversial performance issues which were raised at last year's meeting. Progress was also made on several aspects of producing molybdenum-99 from fission targets utilizing LEU instead of HEU. Various types of targets and processes are being pursued, with FDA approval of an LEU process projected to occur within two years. The feasibility of LEU Fuel conversion for three important DOE research reactors (BMRR, HFBR, and HFIR) has been evaluated by the RERTR program. In spite of the many momentous events which have occurred during the intervening years, and the excellent progress achieved, the most important challenges that the RERTR program faces today are not very different in type from those that were faced during the first RERTR meeting. Now, as then, the most important task is to develop new LEU fuels satisfying requirements which cannot be satisfied by any

  2. The U.S. RERTR Program. Status and progress

    International Nuclear Information System (INIS)

    Travelli, A.

    1997-01-01

    The progress of the Reduced Enrichment Research and Test Reactor (RERTR) Program since its inception in 1978 is described. A brief summary of the results which the RERTR Program had achieved by the end of 1996 in collaboration with its many international partners is followed by a detailed review of the major events, findings, and activities of 1997. Significant progress has been made during the past year. In the area of U.S. acceptance of spent fuel from foreign research reactors, several shipments have taken place and additional are being planned. Intense fuel development activities are in progress, including procurement of equipment, screening of candidate materials, and production of microplates. Irradiation of the first series of microplates began in August 1997 in the Advanced Test Reactor, in Idaho. Progress has been made in the Russian RERTR program, which aims to develop and demonstrate within five years the technical means needed to convert Russian-supplied research reactors to LEU fuels. The study of an alternative LEU core for the FRM-II design has been extended to address, with favorable results, controversial performance issues which were raised at last year's meeting. Progress was also made on several aspects of producing molybdenum-99 from fission targets utilizing LEU instead of HEU. Various types of targets and processes are being pursued, with FDA approval of an LEU process projected to occur within two years. The feasibility of LEU fuel conversion for three important DOE research reactors (BMRR, HFBR, and HFIR) has been evaluated by the RERTR program. In spite of the many momentous events which have occurred during the intervening years, and the excellent progress achieved, the most important challenges that the RERTR program faces today are not very different in type from those that were faced during the first RERTR meeting. Now, as then, the most important task is to develop new LEU fuels satisfying requirements which cannot be satisfied by any

  3. Neutronic analysis of HEU to LEU conversion calculation for AEOI 5 MW pool-type MTR fuel research reactor core

    International Nuclear Information System (INIS)

    Pazirandeh, A.; Lutz, D.; Bartsch, G.

    1987-07-01

    The possibility of converting HEU(93%) fuel to LEU(20%) fuel without or with slight alteration to the fuel element geometry is discussed. The fuel density varies between 1.7 to 4.1 g U-235/cm. In cross section generation a unit cell with an extra zone to account for extra Al and water was considered. In burnup calculations a sequential shuffling pattern was assumed with fixed position control fuel elements. A cross section data set in 45 energy groups were generated using RSYST/CGM system using the cross section library JFET. Then for 2D-diffusion calculations homogenized and condensed 5 energy group cross sections were prepared. (orig./HP)

  4. Alternate technologies for MRS design

    International Nuclear Information System (INIS)

    Smith, R.I.; Triplett, M.B.; Ashton, W.B.; Kelly, W.S.

    1984-01-01

    This paper describes the process conducted by the Pacific Northwest Laboratory (PNL) to evaluate candidate MRS concepts and to recommend the two most preferred concepts. The eight concepts studied are: metal cask (stationary and transportable); concrete cask (silo); concrete cask-in-trench; field drywell; tunnel drywell; open cycle vault; closed cycle vault; and tunnel rack vault. To achieve a more equitable comparison of the concepts, conceptual design analyses were performed for the candidate concepts using a common set of specified design requirements selected with consideration of the MRS mission. Using this normalized conceptual design information, the MRS concepts were evaluated and compared on the basis of their relative performance on seven criteria: flexibility, concept maturity, cost, environmental impacts, safety and licensing, socioeconomic impacts, and siting requirements. These seven criteria were judged to form a reasonable and complete basis for the evaluation of MRS concepts' ability to satisfy the MRS mission requirements. 5 references, 8 figures, 1 table

  5. Nuclear safety analyses and core design calculations to convert the Texas A & M University Nuclear Science Center reactor to low enrichment uranium fuel. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Parish, T.A.

    1995-03-02

    This project involved performing the nuclear design and safety analyses needed to modify the license issued by the Nuclear Regulatory Commission to allow operation of the Texas A& M University Nuclear Science Center Reactor (NSCR) with a core containing low enrichment uranium (LEU) fuel. The specific type of LEU fuel to be considered was the TRIGA 20-20 fuel produced by General Atomic. Computer codes for the neutronic analyses were provided by Argonne National Laboratory (ANL) and the assistance of William Woodruff of ANL in helping the NSCR staff to learn the proper use of the codes is gratefully acknowledged. The codes applied in the LEU analyses were WIMSd4/m, DIF3D, NCTRIGA and PARET. These codes allowed full three dimensional, temperature and burnup dependent calculations modelling the NSCR core to be performed for the first time. In addition, temperature coefficients of reactivity and pulsing calculations were carried out in-house, whereas in the past this modelling had been performed at General Atomic. In order to benchmark the newly acquired codes, modelling of the current NSCR core with highly enriched uranium fuel was also carried out. Calculated results were compared to both earlier licensing calculations and experimental data and the new methods were found to achieve excellent agreement with both. Therefore, even if an LEU core is never loaded at the NSCR, this project has resulted in a significant improvement in the nuclear safety analysis capabilities established and maintained at the NSCR.

  6. Preliminary radiological consequence estimates for a reference LEU core for PARR

    International Nuclear Information System (INIS)

    Ali Khan, L.

    1990-01-01

    Radiological consequence analysis of a reference LEU core for Pakistan Research Reactor (PARR) has been carried out using mathematical models. It was assumed that 20% of the fuel, having an average burn-up of 50% achieved by continuously operating the reactor for 300 days at 10 MW, fails. It was further assumed that 100% of the noble gases and a fraction of iodine are released. Three modes of leakage from reactor building have been considered. These are exhaust through the normal ventilation system, through emergency ventilation system and leakage from the building. The whole body and thyroid doses have been calculated for 2 hours and 30 days at the boundaries of the exclusion zone at 450m and the low population zone at 1000m. For the releases at stack height through normal and emergency ventilation system, doses at both the boundaries remain within emergency dose limits of 300 rem for thyroid and 25 rem for the whole body. However, in the case of direct release from the containment building, the limiting thyroid dose of 300 rem, at 1000m, for 30 days exposure is achieved for a leak rate of 27% per day under Pasquill condition E. The results presented in this report are only preliminary estimates. A more accurate detailed analysis for various burnups will be carried out using standard computer codes

  7. Comparison of control rod effectiveness for thorium and low-enriched fuel cycles in the GA-1, 160 MW(e) design

    Energy Technology Data Exchange (ETDEWEB)

    Neef, Hans Joachim

    1974-03-15

    In an investigation of the properties of the Thorium-Uranium (Th) and the Low-Enriched Uranium (LEU) fuel cycles it is also necessary to compare the effectiveness of the control rods in a reactor system operating with these sorts of fuel. Furthermore, it is under consideration to start a reactor with LEU fuel and switch-over to a Th cycle. It is also of interest to look at the switch-over phase in respect to the control rod effectiveness. The various fuel cycles have been studied for the same fuel element and control rod design, namely the one of GA's commercially available 1,160 MW(e) reference power station. This paper gives the first results on the control rod calculations and is presented mainly in two parts. Part 1 describes spectral effects which have been investigated by cell calculations with a discrete ordinates transport code. The main result is the higher effectiveness of a rod in a Th-cycle compared with a LEU-cycle. Part 2 reports on reactor calculations with a diffusion code and shows that this advantage can partially disappear in the reactor because of the spatial flux distribution. This effect has to be studied in further investigations for a full understanding.

  8. Neutronic calculations for the conversion of the University of Florida Training Reactor from HEU to LEU fuel

    International Nuclear Information System (INIS)

    Dugan, E.T.; Diaz, N.J.; Kniedler, G.S.

    1983-01-01

    The University of Florida Training Reactor (UFTR) is located on the University of Florida campus in Gainesville, Florida. The reactor is the Argonaut type, heterogeneous in design and currently fueled with 93% enriched, uranium-aluminum alloy MTR plate-type fuel. Investigations are being performed to examine te feasibility of replacing the highly-enriched fuel of the current UFTR with 4.8% enriched, cylindrical pin SPERT fuel. The SPERT fuel is stainless steel clad and contains uranium dioxide (UO 2 ) pellets. On a broad spectrum, training reactor conversion from high enrichment uranium (HEU) to low enrichment uranium (LEU) fueled facilities has been a continuing concern in the International Atomic Energy Agency (IAEA) and significant work has been done in this area by the Argonne RERTR Program. The International Atomic Energy Agency cites three reasons for reactor conversion to low-enriched uranium. The main reason is the desire to reduce the proliferation potential of research reactor fuels. The second is to increase the assurance of continued fuel availability in the face of probable restrictions on the supply of highly-enriched uranium. The third reason is the possible reduction in requirements for physical security measures during fabrication, transportation, storage and use. This same IAEA report points out that the three reasons stated for the conversion of the fuel of research reactors are interrelated and cannot be considered individually. The concerns of the Nuclear Engineering Sciences Department at the University of Florida relating to the HEU fuel of the UFTR coincide with those of the International Atomic Energy Agency. The primary reason for going to low-enriched pin-type fuel is the concern with proliferation provoked by the highly-enriched plate fuel which has led to tighter security of nuclear facilities such as the UFTR. A second reason for changing to the pin-type fuel is because of difficulties that are being encountered in the supply of the

  9. Neutronic calculations for the conversion of the University of Florida Training Reactor from HEU to LEU fuel

    Energy Technology Data Exchange (ETDEWEB)

    Dugan, E T; Diaz, N J [Department of Nuclear Engineering Sciences, University of Florida, Gainesville, FL (United States); Kniedler, G S [Reactor Analysis Group, TVA, Chattanooga, TN (United States)

    1983-09-01

    The University of Florida Training Reactor (UFTR) is located on the University of Florida campus in Gainesville, Florida. The reactor is the Argonaut type, heterogeneous in design and currently fueled with 93% enriched, uranium-aluminum alloy MTR plate-type fuel. Investigations are being performed to examine te feasibility of replacing the highly-enriched fuel of the current UFTR with 4.8% enriched, cylindrical pin SPERT fuel. The SPERT fuel is stainless steel clad and contains uranium dioxide (UO{sub 2}) pellets. On a broad spectrum, training reactor conversion from high enrichment uranium (HEU) to low enrichment uranium (LEU) fueled facilities has been a continuing concern in the International Atomic Energy Agency (IAEA) and significant work has been done in this area by the Argonne RERTR Program. The International Atomic Energy Agency cites three reasons for reactor conversion to low-enriched uranium. The main reason is the desire to reduce the proliferation potential of research reactor fuels. The second is to increase the assurance of continued fuel availability in the face of probable restrictions on the supply of highly-enriched uranium. The third reason is the possible reduction in requirements for physical security measures during fabrication, transportation, storage and use. This same IAEA report points out that the three reasons stated for the conversion of the fuel of research reactors are interrelated and cannot be considered individually. The concerns of the Nuclear Engineering Sciences Department at the University of Florida relating to the HEU fuel of the UFTR coincide with those of the International Atomic Energy Agency. The primary reason for going to low-enriched pin-type fuel is the concern with proliferation provoked by the highly-enriched plate fuel which has led to tighter security of nuclear facilities such as the UFTR. A second reason for changing to the pin-type fuel is because of difficulties that are being encountered in the supply of

  10. User-Centered Design and Augmentative and Alternative Communication Apps for Children With Autism Spectrum Disorders

    Directory of Open Access Journals (Sweden)

    Margaret Lubas

    2014-05-01

    Full Text Available Communication difficulties are among the most frequent characteristics of children with autism spectrum disorders (ASD. Lack of communication can have a significant impact on the child’s life. Augmentative and alternative communication (AAC apps are a common form of AAC interventions that involve a combination of affordable technology with software that can be utilized to assist with communication. While AAC apps have been found to have some impact on improving the communication skills of children with ASD, current research exploring this topic is still limited. Focusing on the design process of AAC apps may provide better insight into improving clinical outcomes and user success. The user-centered design process incorporates a continuous cycle of user feedback to help inform and improve the functions and the capabilities of the technology, and it is an essential component in AAC app development. This article outlines how the user-centered design process could be adopted for the development of AAC apps for children with ASD.

  11. Flued head replacement alternatives

    International Nuclear Information System (INIS)

    Smetters, J.L.

    1987-01-01

    This paper discusses flued head replacement options. Section 2 discusses complete flued head replacement with a design that eliminates the inaccessible welds. Section 3 discusses alternate flued head support designs that can drastically reduce flued head installation costs. Section 4 describes partial flued head replacement designs. Finally, Section 5 discusses flued head analysis methods. (orig./GL)

  12. The Ford Nuclear Reactor demonstration project for the evaluation and analysis of low enrichment fuel

    International Nuclear Information System (INIS)

    Kerr, W.; King, J.S.; Lee, J.C.; Martin, W.R.; Wehe, D.K.

    1991-07-01

    The whole-core LEU fuel demonstration project at the University of Michigan was begun in 1979 as part of the Reduced Enrichment Research and Test Reactor (RERTR) Program at Argonne National Laboratory. An LEU fuel design was selected which would produce minimum perturbations in the neutronic, operations, and safety characteristics of the 2-MW Ford Nuclear Reactor (FNR). Initial criticality with a full LEU core on December 8, 1981, was followed by low- and full-power testing of the fresh LEU core, transitional operation with mixed HEU-LEU configurations, and establishment of full LEU equilibrium core operation. The transition from the HEU to the LEU configurations was achieved with negligible impact on experimental utilization and safe operation of the reactor. 78 refs., 74 figs., 84 tabs

  13. Up-Rating - An Alternative Approach to Meeting Future Power Demands - Exploitation of Design Margins

    Energy Technology Data Exchange (ETDEWEB)

    Bruce, Barnaby; Schwarz, Thomas [AREVA NP GmbH, Freyeslebenstr. 1, 91058 Erlangen (Germany)

    2008-07-01

    Up-rating is a world-wide implemented approach that takes advantage of increased calculation and analytic abilities developed since commissioning and applies them to old plants. In doing so, what would possibly be considered today as over-engineered design margins are exploited and plant performance is improved, without necessarily involving extensive modifications or replacement of hardware. It is therefore a short-term alternative, compared to new plants, with little change in environmental ramifications for power production capacity gained. Up-rating is also more accepted by the wider community and licensing authorities, thus complimenting the building of new plants. The 10% thermal up-rating of the nuclear power plant at Almaraz, Spain, requires a comprehensive reanalysis of all power components. This paper focuses on those measures required to ensure the performance of the steam generators at increased load as an example of design margin exploitation in such crucial components. (authors)

  14. Results of Microstructural Examinations of Irradiated LEU U-Mo Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Keiser, D.D. Jr.; Jue, J.F.; Robinson, A.B. [Idaho National Laboratory, P.O. Box 2528, Idaho Falls, ID 83415-6188 (United States); Finlay, M.R. [Australian Nuclear Science and Technology Organization (Australia)

    2009-06-15

    Introduction: The RERTR program is responsible for converting research reactors that use high-enriched uranium fuels to ones that use low-enriched uranium fuels [1]. As part of the development of LEU fuels, a variety of irradiation experiments are being conducted using the Advanced Test Reactor. Based on the results of initial fuel plate testing, adjustments have been made to the characteristics of fuel plates to improve the stability of the fuel microstructure. One improvement has been to add Si to the matrix of a dispersion fuel. This material is also being added at the fuel/cladding interface of a monolithic fuel. This paper will discuss the irradiation performance of these fuels, in terms of the stability of their microstructures during irradiation. Results and discussion: The post-irradiation examinations of fuel plates are performed at the Idaho National Laboratory. These examinations consist of visual examinations of fuel plates, gamma scanning, thickness measurements, oxide thickness measurements, and optical metallographic examinations of the fuel plate microstructures. Microstructural analysis is also performed using scanning electron microscopy. Overall, U-7Mo and U-10Mo alloy fuels have displayed the best irradiation performance, particularly, when a Si-containing Al alloy is used as the dispersion fuel matrix. The benefit of using this type of matrix is that the commonly observed fuel/cladding interaction that occurs during irradiation is reduced and the interaction layer that forms exhibit stable behavior during irradiation. Monolithic-type fuels, which consist of a U-Mo foil encased in Al alloy cladding, are also being developed. These types of fuels are also showing promise and will continue to be developed. One challenge with this type of fuel is in trying to maximize the bond strength at the foil/cladding interface. Fuel/cladding interactions can affect the quality of the boding at this interface. Si is being added to improve the characteristics

  15. Rapid Prototyping: An Alternative Instructional Design Strategy.

    Science.gov (United States)

    Tripp, Steven D.; Bichelmeyer, Barbara

    1990-01-01

    Discusses the nature of instructional design and describes rapid prototyping as a feasible model for instructional system design (ISD). The use of prototyping in software engineering is described, similarities between software design and instructional design are discussed, and an example is given which uses rapid prototyping in designing a…

  16. Neutronic analysis of a reference LEU core for Pakistan research reactor using oxide fuel

    International Nuclear Information System (INIS)

    Akhtar, K.M.; Qazi, M.K.; Bokhari, I.H.; Khan, L.A.; Pervez, S.

    1988-07-01

    Neutronic analysis of a 10 MW reference core for PARR, having 28 fresh LEU fuel elements arranged in a 6x5 configuration has been carried out using standard computer codes WIMS-D, EXTERMINATOR-II, and CITATION. Total nuclear power peaking of 3.2 has bee found to occur in the fuel plate adjacent to the water filled central flux trap at the depth of 43.8 cm from the top of the active core. Replacement of water in central flux trap with an aluminum block, having a 50 mm diameter water filled irradiation channel changes the flux profiles in fuel, core side flux trap and reflector. The thermal flux in the central flux trap decreases by about 53%. Therefore some of the fuel elements will have to be removed and the new configuration has to be analysed to determine the first operating core. However, after achieving some burn-up and confirmation from thermal hydraulic analysis, the core configuration analysed, will be the final working core. (orig./A.B.)

  17. DESIGN AND DEVELOPMENT OF AUGMENTATIVE AND ALTERNATIVE DIGITAL HOME CONTROL INTERFACE

    Directory of Open Access Journals (Sweden)

    Matteo Pastorino

    2013-05-01

    Full Text Available An inquiry of the National Statistics Institute of Spain shows that 74% of the Spanish population with disabilities suffers some kind of limitation performing Daily Basic Activities, while 1.39 million cannot perform them at all without the assistance of specialized personnel. Digital Home Systems could mitigate disabled people’s difficulties to carry out those activities, giving the opportunity to manage home appliances through a single control. Digital Home Systems have to provide specific and adapted control interfaces based on Augmentative and Alternative Communication languages in order to be an efficient solution to the problem and to allow most vulnerable groups of people with disabilities to reach the highest level of autonomy.  This paper describes a Digital Home Interface capable of adapting layouts, styles and contents to device capability, user preferences and appliances’ features; designed with a combination of web technologies, standard languages for abstract interface definition and AAC systems.

  18. Development of the Mo-99 process at CRNL

    International Nuclear Information System (INIS)

    Burrill, K.A.; Harrison, R.J.

    1987-11-01

    Highly enriched uranium (HEU) is used for Mo-99 production at CRNL. Dissolution of the targets and loading of the solution onto AI 2 0 3 columns is discussed. Development work continues to reduce processing time and overall product cost. A process for treating the fission product waste has been selected and a facility for processing is being designed. Low enriched uranium (LEU) is planned for targets eventually. Our experience with Si-based fuel for targets is poor, and alternatives are being sought

  19. Global Energy Issues and Alternate Fueling

    Science.gov (United States)

    Hendricks, Robert C.

    2007-01-01

    This viewgraph presentation describes world energy issues and alternate fueling effects on aircraft design. The contents include: 1) US Uses about 100 Quad/year (1 Q = 10(exp 15) Btu) World Energy Use: about 433 Q/yr; 2) US Renewable Energy about 6%; 3) Nuclear Could Grow: Has Legacy Problems; 4) Energy Sources Primarily NonRenewable Hydrocarbon; 5) Notes; 6) Alternate Fuels Effect Aircraft Design; 7) Conventional-Biomass Issue - Food or Fuel; 8) Alternate fuels must be environmentally benign; 9) World Carbon (CO2) Emissions Problem; 10) Jim Hansen s Global Warming Warnings; 11) Gas Hydrates (Clathrates), Solar & Biomass Locations; 12) Global Energy Sector Response; 13) Alternative Renewables; 14) Stratospheric Sulfur Injection Global Cooling Switch; 15) Potential Global Energy Sector Response; and 16) New Sealing and Fluid Flow Challenges.

  20. Effect of Leu-enkephalin and delta sleep inducing peptide (DSIP) on endogenous noradrenaline release by rat brain synaptosomes

    International Nuclear Information System (INIS)

    Lozhanets, V.V.; Anosov, A.K.

    1986-01-01

    The nonapeptide delta-sleep inducing peptide (DSIP) causes specific changes in the encephalogram of recipient animals: It prolongs the phase of long-wave or delta sleep. The cellular mechanism of action of DSIP has not yet been explained. To test the hyporhesis that this peptide or its degradation product may be presynaptic regulators of catecholamine release, the action of Leu-enkephaline, DSIP, and amino acids composing DSIP on release of endogenous noradrenalin (NA) from synaptosomes during depolarization was compared. Subcellular fractions from cerebral hemisphere of noninbred male albino rats were isolated. Lactate dehydrogenase activity was determined in the suspension of synaptosomes before and after addition of 0.5% Triton X-100. The results were subjected to statistical analysis, using the Wilcoxon-Mann-Whitney nonparametric test

  1. THE WIND DEFLATION FROM SAND AREAS AFFECTED BY ATMOSFERIC DRYNESS: LEU-ROTUNDA AND DĂBULENI FIELDS (OLTENIA PLAIN

    Directory of Open Access Journals (Sweden)

    ROȘCA FLORINA CRISTINA

    2014-03-01

    Full Text Available Leu-Rotunda and Dăbuleni Fields are characterized by substantial extension of sandy soils. The sands on the left of Jiu are poli-stratificated fluvial deposits eolian shaped as dunes and interdunes. During the reported period 1980-2007, it was found that the most exposed time of the year to the wind was during the spring, the months of March, April and May as in speed and frequency. According to the analyzed data, the dominant wind direction during spring season on the sandy soils from Dăbuleni is the western, with negative effects on crops who then begin their vegetation cycle. The shelterbelts have decreased, although lately there have been numerous programs which aimed afforestation of affected areas.

  2. Backbone and stereospecific (13)C methyl Ile (δ1), Leu and Val side-chain chemical shift assignments of Crc.

    Science.gov (United States)

    Sharma, Rakhi; Sahu, Bhubanananda; Ray, Malay K; Deshmukh, Mandar V

    2015-04-01

    Carbon catabolite repression (CCR) allows bacteria to selectively assimilate a preferred compound among a mixture of several potential carbon sources, thus boosting growth and economizing the cost of adaptability to variable nutrients in the environment. The RNA-binding catabolite repression control (Crc) protein acts as a global post-transcriptional regulator of CCR in Pseudomonas species. Crc triggers repression by inhibiting the expression of genes involved in transport and catabolism of non-preferred substrates, thus indirectly favoring assimilation of preferred one. We report here a nearly complete backbone and stereospecific (13)C methyl side-chain chemical shift assignments of Ile (δ1), Leu and Val of Crc (~ 31 kDa) from Pseudomonas syringae Lz4W.

  3. Alternative Fuels Data Center: Publications

    Science.gov (United States)

    Windstars; 14) and the use of alternative fuel vehicles at the Olympics. Alternative Fuels In Trucking, Vol and their economic and environmental benefits. This report is designed to share the experiences and National Academy of Engineering suggested that 'DOE might have its greatest impact by leading the private

  4. Design and hardware alternatives for a Safety-Parameter Display System

    International Nuclear Information System (INIS)

    Honeycutt, F.; Merten, W.T.; Roy, G.M.; Segraves, E.; Stone, G.P.

    1981-05-01

    The SPDS is a dedicated control room operator aid and is viewed as an important safety improvement within the context of other post-TMI fixes. Hardware configurations and components to implement the NSAC display format of a Safety Parameter Display System (SPDS) are evaluated. The evaluation was made on the basis of five alternative hardware configurations which use commercially available components. Four of the alternatives use computer/video display architecture. The fifth alternative is a simple hardwired system which uses strip chart recorders. SPDS regulatory requirements are defined by NUREG 0696. Overall feasibility of the NSAC concept was evaluated in terms of performance, reliability, cost, licensability, and flexibility. The flexibility evaluation relates to the ability to handle other display formats, the data acquisition needs of the other emergency facilities and the impact of expected future NRC requirements

  5. Results of developing and problems of further improvements for WWER-1000 FA of alternative design

    International Nuclear Information System (INIS)

    Molchanov, V.L.; Panyushkin, A.K.; Zheleznyak, V.M.; Samojlov, O.B.; Kuul', V.S.; Kurylev, V.I.

    2001-01-01

    A new fuel assembly of alternative design (FAA) is created for a WWER-1000 reactor which is characteristic of dimensional stability on operation. The FAA includes a frame of 15 alloy Eh-110 spacer grids spot welded to 6 alloy Eh-635 angle sections. In-core tests show that the FAA is stable to form changing. It is concluded that the FAA can serve as a basis for development of promising fuel cycle with high burnups, specifically, for a 4 year cycle with the use of uranium-gadolinium fuel [ru

  6. Accurate Determination of Leucine and Valine Side-chain Conformations using U-[{sup 15}N/{sup 13}C/{sup 2}H]/[{sup 1}H-(methine/methyl)-Leu/Val] Isotope Labeling, NOE Pattern Recognition, and Methine C{gamma}-H{gamma}/C{beta}-H{beta} Residual Dipolar Couplings

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Chun; Iwahara, Junji; Clore, G. Marius [National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Laboratory of Chemical Physics (United States)], E-mail: mariusc@intra.niddk.nih.gov

    2005-10-15

    An isotope labeling scheme is described in which specific protonation of methine and methyl protons of leucine and valine is obtained on a {sup 15}N/{sup 13}C labeled background with uniform deuteration of all other non-exchangeable protons. The presence of a protonated methine group has little effect on the favorable relaxation properties of the methyl protons of Leu and Val. This labeling scheme permits the rotameric state of leucine side-chains to be readily determined by simple inspection of the pattern of H{gamma}(i)-H{sub N}(i) and H{gamma}(i)-H{sub N}(i+1) NOEs in a 3D {sup 15}N-separated NOE spectrum free of complications arising from spectral overlap and spin-diffusion. In addition, one-bond residual dipolar couplings for the methine {sup 13}C-{sup 1}H bond vectors of Leu and Val can be accurately determined from an intensity J-modulated constant-time HCCH-COSY experiment and used to accurately orient the side-chains of Leu and Val. Incorporation of these data into structure refinement improves the accuracy with which the conformations of Leu and Val side-chains can be established. This is important to ensure optimal packing both within the protein core and at intermolecular interfaces. The impact of the method on protein structure determination is illustrated by application to enzyme IIA{sup Chitobiose}, a 34 kDa homotrimeric phosphotransferase protein.

  7. A comparative analysis for multiattribute selection among renewable energy alternatives using fuzzy axiomatic design and fuzzy analytic hierarchy process

    Energy Technology Data Exchange (ETDEWEB)

    Kahraman, Cengiz; Kaya, Ihsan; Cebi, Selcuk [Istanbul Technical University, Department of Industrial Engineering, 34367, Macka-Istanbul (Turkey)

    2009-10-15

    Renewable energy is the energy generated from natural resources such as sunlight, wind, rain, tides and geothermal heat which are renewable. Energy resources are very important in perspective of economics and politics for all countries. Hence, the selection of the best alternative for any country takes an important role for energy investments. Among decision-making methodologies, axiomatic design (AD) and analytic hierarchy process (AHP) are often used in the literature. The fuzzy set theory is a powerful tool to treat the uncertainty in case of incomplete or vague information. In this paper, fuzzy multicriteria decision- making methodologies are suggested for the selection among renewable energy alternatives. The first methodology is based on the AHP which allows the evaluation scores from experts to be linguistic expressions, crisp, or fuzzy numbers, while the second is based on AD principles under fuzziness which evaluates the alternatives under objective or subjective criteria with respect to the functional requirements obtained from experts. The originality of the paper comes from the fuzzy AD application to the selection of the best renewable energy alternative and the comparison with fuzzy AHP. In the application of the proposed methodologies the most appropriate renewable energy alternative is determined for Turkey. (author)

  8. Some Main Results of Commissioning of the Dalat Research Reactor with Low Enriched Fuel

    International Nuclear Information System (INIS)

    Nguyen Nhi Dien; Luong Ba Vien; Pham Van Lam; Le Vinh Vinh; Huynh Ton Nghiem

    2014-01-01

    After completion of design calculation of the Dalat Nuclear Research Reactor (DNRR) for conversion from high-enriched uranium fuel (HEU) to low-enriched uranium (LEU) fuel, the commissioning programme for DNRR with entire core loaded with LEU fuel was successfully carried out from 24 November 2011 to 13 January 2012. The experimental results obtained during the implementation of commissioning programme showed a good agreement with design calculations and affirmed that the DNRR with LEU core have met all safety and exploiting requirements. (author)

  9. SustainPro - A tool for systematic process analysis, generation and evaluation of sustainable design alternatives

    DEFF Research Database (Denmark)

    Carvalho, Ana; Matos, Henrique A.; Gani, Rafiqul

    2013-01-01

    the user through the necessary steps according to work-flow of the implemented methodology. At the end the design alternatives, are evaluated using environmental impact assessment tools and safety indices. The extended features of the methodology incorporate Life Cycle Assessment analysis and economic....... The software tool is based on the implementation of an extended systematic methodology for sustainable process design (Carvalho et al. 2008 and Carvalho et al. 2009). Using process information/data such as the process flowsheet, the associated mass / energy balance data and the cost data, SustainPro guides...... analysis. The application and the main features of SustainPro are illustrated through a case study of ß-Galactosidase production....

  10. Preliminary Multiphysics Analyses of HFIR LEU Fuel Conversion using COMSOL

    Energy Technology Data Exchange (ETDEWEB)

    Freels, James D [ORNL; Bodey, Isaac T [ORNL; Arimilli, Rao V [ORNL; Curtis, Franklin G [ORNL; Ekici, Kivanc [ORNL; Jain, Prashant K [ORNL

    2011-06-01

    4 of this report. The HFIR LEU conversion project has also obtained the services of Dr. Prashant K. Jain of the Reactor & Nuclear Systems Division (RNSD) of ORNL. Prashant has quickly adapted to the COMSOL tools and has been focusing on thermal-structure interaction (TSI) issues and development of alternative 3D model approaches that could yield faster-running solutions. Prashant is the primary contributor to Section 5 of the report. And finally, while incorporating findings from all members of the COMSOL team (i.e., the team) and contributing as the senior COMSOL leader and advocate, Dr. James D. Freels has focused on the 3D model development, cluster deployment, and has contributed primarily to Section 3 and overall integration of this report. The team has migrated to the current release of COMSOL at version 4.1 for all the work described in this report, except where stated otherwise. Just as in the performance of the research, each of the respective sections has been originally authored by the respective authors. Therefore, the reader will observe a contrast in writing style throughout this document.

  11. Modification Design of Petrol Engine for Alternative Fueling using Compressed Natural Gas

    Directory of Open Access Journals (Sweden)

    Eliezer Uchechukwu Okeke

    2013-04-01

    Full Text Available This paper is on the modification design of petrol engine for alternative fuelling using Compressed Natural Gas (CNG. It provides an analytical background in the modification design process. A petrol engine Honda CR-V 2.0 auto which has a compression ratio of 9.8 was selected as case study. In order for this petrol engine to run on CNG, its compression had to be increased. An optimal compression ratio of 11.97 was computed using the standard temperature-specific volume relationship for an isentropic compression process. This computation of compression ratio is based on an inlet air temperature of 30oC (representative of tropical ambient condition and pre-combustion temperature of 540oC (corresponding to the auto-ignition temperature of CNG. Using this value of compression ratio, a dimensional modification Quantity =1.803mm was obtained using simple geometric relationships. This value of 1.803mm is needed to increase the length of the connecting rod, the compression height of the piston or reducing the sealing plate’s thickness. After the modification process, a CNG engine of air standard efficiency 62.7% (this represents a 4.67% increase over the petrol engine, capable of a maximum power of 83.6kW at 6500rpm, was obtained.

  12. Alternative practices in curriculum design. Participation as a key factor and speaking out as right

    Directory of Open Access Journals (Sweden)

    Susana Barco

    2012-06-01

    Full Text Available During the 1990s, in the context of neo-liberal policies, curricular changes ocurred in Latin América which gave a leading role to technicians and experts in education, in the process of writing the curricular documents. Beyond the critiques these policies can receive, it is necessary to find alternative ways of elaborating curricular documents, based on democratic idea of teacher's real participation.In an action-research within the scope of a university and two experiences referred to in this work, different participative styles emerged, according to their particular circumstances. This work referred to these processes and its theoretical foundations, reporting alternative ways of curricular design based on teacher's participation and its different forms. The aim is to enhance how teachers as a social subject can 'stand up for themselves'and 'speak out' in the specific practice of writing curricular documents. Taking into account that teaching practices rewrite curricular documents, different dynamics in curricular change are possible, allowing adjusting and adapting realities in each institution, and propelling collaborative work.

  13. Core conversion anaylses for the Portuguese Research Reactor

    International Nuclear Information System (INIS)

    Matos, J.E.; Stevens, J.G.; Feldman, E.E.; Stillman, J.A.; Dunn, F.E.; Kalimullah, K.; Marques, J.G.; Barradas, N.P.; Ramos, A.R.; Kling, A.

    2006-01-01

    Design and safety analyses are presented for conversion of the Portuguese Research Reactor (RPI) from the use of HEU fuel to the use of LEU fuel. The analyses were performed jointly by the RERTR Program at the Argonne National Laboratory (ANL) and the Instituto Tecnologico e Nuclear (ITN). The LEU fuel assembly design uses U 3 Si 2 -Al dispersion fuel with 4.8 g U/cm 3 and is very similar to the HEU fuel design. The results of neutronic studies, steady-state thermal-hydraulic analyses, accident analyses, and revisions to the Operating Limits and Conditions demonstrate that the RPI reactor can be operated safely with the new LEU fuel assemblies. Delivery of the LEU fuel is expected around the end of 2006, with conversion in early 2007. The HEU fuel is planned to be returned to the US in 2008.

  14. Integrin beta3 Leu33Pro polymorphism and risk of hip fracture: 25 years follow-up of 9233 adults from the general population

    DEFF Research Database (Denmark)

    Tofteng, Charlotte L; Bach-Mortensen, Pernille; Bojesen, Stig E

    2007-01-01

    OBJECTIVE: Integrin alphavbeta3 is essential for mature osteoclast function and therefore important for the development of osteoporosis and osteoporotic fractures. Integrin alphavbeta3 antagonists have antiresorptive effects in bone. We tested the hypothesis that the Leu33Pro polymorphism...... in the integrin beta3-subunit associates with risk of hip fracture. METHODS: We included 9233 men and women selected at random to represent the Danish general population as participants in the Copenhagen City Heart Study. First-ever hip fractures (n=267) were registered during 25 years follow-up. Log...

  15. Development of Techniques for Small Scale Indigenous 99Mo Production Using LEU Targets at ICN Pitesti-Romania [Country report: Romania

    International Nuclear Information System (INIS)

    2015-01-01

    Initiation of the IAEA Coordinated Research Project (CRP) “Development Techniques for Small Scale Indigenous 99 Mo Production Using LEU Fission or Neutron Activation” during 2005 allowed Member States to participate through their research organization on contractor arrangement to accomplish the CRP objectives. Among these, the participating research organization Institute for Nuclear Research Pitesti Romania (ICN), was the beneficiary of financial support and Argonne National Laboratory assistance provided by US Department of Energy to the CRP for development of techniques for fission 99 Mo production based on LEU modified CINTICHEM process. The Agency’s role in this field was to assist in the transfer and adaptation of existing technology in order to disseminate a technique, which advances international non-proliferation objectives and promotes sustainable development needs, while also contributing to extend the production capacity for addressing supply shortages from the latest years. The Institute for Nuclear Research, considering the existing good conditions of infrastructure of the research reactor with suitable irradiation conditions for radioisotopes, a post irradiation laboratory with direct transfer of irradiated targets from the reactor and handling of high radioactive sources, and simultaneously the existence of an expanding internal market, decided to undertake the necessary steps in order to produce fission molybdenum. The Institute intends to develop the capability to respond to the domestic needs in cooperation with the IFINN–HH from Bucharest, which is able to perform the last step consisting in the loading of fission molybdenum on chromatography generators and dispensing to the final client. The primary scope of the project is the development of the necessary technological steps and chemical processing steps in order to be able to cover the entire process for fission molybdenum production at the required standard of purity

  16. Development of new ORIGEN2 data library sets for research reactors with light water cooled oxide and silicide LEU (20 w/o) fuels based on JENDL-3.3 nuclear data

    International Nuclear Information System (INIS)

    Liem, Peng Hong; Sembiring, Tagor Malem

    2013-01-01

    Highlights: • We developed new ORIGEN2 data library sets for research reactors based on JENDL-3.3. • The sets cover oxide and silicide LEU fuels with meat density up to 4.74 g U/cm 3 . • Two kinds of data library sets are available: fuel region and non-fuel regions. • We verified the new data library sets with other codes. • We validated the new data library against a non-destructive test. -- Abstract: New sets of ORIGEN2 data library dedicated to research/testing reactors with light water cooled oxide and silicide LEU fuel plates based on JENDL-3.3 nuclear data were developed, verified and validated. The new sets are considered to be an extension of the most recent release of ORIGEN2.2UPJ code, i.e. the ORLIBJ33 library sets. The newly generated ORIGEN2 data library sets cover both oxide and silicide LEU fuels with fuel meat density range from 2.96 to 4.74 g U/cm 3 used in the present and future operation of the Indonesian 30 MWth RSG GAS research reactor. The new sets are expected applicable also for other research/testing reactors which utilize similar fuels or have similar neutron spectral indices. In addition to the traditional ORIGEN2 library sets for fuel depletion analyses in fuel regions, in the new data library sets, new ORIGEN2 library sets for irradiation/activation analyses were also prepared which cover all representative non-fuel regions of RSG GAS such as reflector elements, irradiation facilities, etc. whose neutron spectra are significantly softer than fuel regions. Verification with other codes as well as validation with a non-destructive test result showed promising results where a good agreement was confirmed

  17. Course of pin fuel test In WWR-M reactor core

    International Nuclear Information System (INIS)

    Zakharov, A.S.; Kirsanov, G.A.; Konoplev, K.A.

    2005-01-01

    Pin type fuel element (FE) of square form with twisted ribs was developed in VNIINM as an alternative for tube type FE of research reactors. Two variants of full-scale fuel assemblies (FA) are under test in the core of PNPI WWR-M reactor. One FA contains FE with UO 2 LEU and other - UMo LEU. Both types of FE have an aluminum matrix. Results of the first stages of the test are presented. (author)

  18. Evaluation of the effectiveness and feasibility of the Waste Isolation Pilot Plant engineered alternatives: Final report of the Engineered Alternatives Task Force

    International Nuclear Information System (INIS)

    1991-07-01

    The Engineered Alternatives Task Force (EATF) was established by the United States Department of Energy (DOE) WIPP Project Office (WPO) in September 1989 (Hunt, A., 1990), to evaluate the relative effectiveness and feasibility of implementation of selected design enhancements (referred to as ''engineered alternatives'') for the Waste Isolation Pilot Plant (WIPP). These enhancements consist of modifications of existing waste forms and/or the WIPP facility, and other design variations such as passive marker systems. The purpose of this report is to summarize the methodologies and results of evaluation of the effectiveness of selected engineered alternatives relative to the existing repository design, and to discuss the feasibility of implementing these alternatives with respect to availability of technology, cost, schedule, and regulatory concerns. The EATF has concluded that a number of engineered alternatives could be implemented to improve repository performance if WIPP performance assessment determines that either gas generation or human intrusion presents a problem in demonstrating compliance. Within waste treatment, Level 3 treatments are the most effective in addressing multiple performance parameters, but tend to be the most expensive, the most difficult and time-consuming to implement, and have the greatest regulatory requirements. Level 2 treatments are less expensive, faster, require less extensive permitting, and utilize off- the-shelf technology, but are less effective in addressing multiple performance parameters. Depending upon the performance parameter, Level 1 alternatives such as alternative backfills, alternative waste containers, or modified repository design should be thoroughly evaluated and eliminated before any decision is made to treat the waste. The present uncertainty in the degree to which the baseline WIPP design complies with 40 CFR Part 191 and 40 CFR Part 268 precludes specific recommendations at this time. 130 refs., 21 figs., 37 tabs

  19. Two key residues in ephrinB3 are critical for its use as an alternative receptor for Nipah virus.

    Directory of Open Access Journals (Sweden)

    2006-02-01

    Full Text Available EphrinB2 was recently discovered as a functional receptor for Nipah virus (NiV, a lethal emerging paramyxovirus. Ephrins constitute a class of homologous ligands for the Eph class of receptor tyrosine kinases and exhibit overlapping expression patterns. Thus, we examined whether other ephrins might serve as alternative receptors for NiV. Here, we show that of all known ephrins (ephrinA1-A5 and ephrinB1-B3, only the soluble Fc-fusion proteins of ephrinB3, in addition to ephrinB2, bound to soluble NiV attachment protein G (NiV-G. Soluble NiV-G bound to cell surface ephrinB3 and B2 with subnanomolar affinities (Kd = 0.58 nM and 0.06 nM for ephrinB3 and B2, respectively. Surface plasmon resonance analysis indicated that the relatively lower affinity of NiV-G for ephrinB3 was largely due to a faster off-rate (K(off = 1.94 x 10(-3 s(-1 versus 1.06 x 10(-4 s(-1 for ephrinB3 and B2, respectively. EphrinB3 was sufficient to allow for viral entry of both pseudotype and live NiV. Soluble ephrinB2 and B3 were able to compete for NiV-envelope-mediated viral entry on both ephrinB2- and B3-expressing cells, suggesting that NiV-G interacts with both ephrinB2 and B3 via an overlapping site. Mutational analysis indicated that the Leu-Trp residues in the solvent exposed G-H loop of ephrinB2 and B3 were critical determinants of NiV binding and entry. Indeed, replacement of the Tyr-Met residues in the homologous positions in ephrinB1 with Leu-Trp conferred NiV receptor activity to ephrinB1. Thus, ephrinB3 is a bona fide alternate receptor for NiV entry, and two residues in the G-H loop of the ephrin B-class ligands are critical determinants of NiV receptor activity.

  20. HEU to LEU Conversion and Blending Facility: UF6 blending alternative to produce LEU UF6 for commercial use

    International Nuclear Information System (INIS)

    1995-09-01

    US DOE is examining options for disposing of surplus weapons-usable fissile materials and storage of all weapons-usable fissile materials; the nuclear material will be converted to a form more proliferation- resistant than the original form. Examining options for increasing the proliferation resistance of highly enriched uranium (HEU) is part of this effort. Five technologies for blending HEU will be assessed; blending as UF 6 to produce a UF 6 product for commercial use is one of them. This document provides data to be used in the environmental impact analysis for the UF 6 blending HEU disposition option. Resource needs, employment needs, waste and emissions from plant, hazards, accident scenarios, and intersite transportation are discussed