28 research outputs found

    Investigation of decommissioned reactor pressure vessels of the nuclear power plant Greifswald

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    The investigation of reactor pressure vessel (RPV) material from the decommissioned Greifswald nuclear power plant representing the first generation of Russian-type WWER-440/V-230 reactors offers the opportunity to evaluate the real toughness response. The Greifswald RPVs of 4 units represent different material conditions as follows: ā€¢ Irradiated (Unit 4), ā€¢ irradiated and recovery annealed (Units 2 and 3), and ā€¢ irradiated, recovery annealed and re-irradiated (Unit1). The recovery annealing of the RPV was performed at a temperature of 475Ā° for about 152 hours and included a region covering Ā±0.70 m above and below the core beltline welding seam. Material samples of a diameter of 119 mm called trepans were extracted from the RPV walls. The research program is focused on the characterisation of the RPV steels (base and weld metal) across the thickness of the RPV wall. This report presents test results measured on the trepans from the beltline welding seam No. SN0.1.4. and forged base metal ring No. 0.3.1. of the Units 1 2 and 4 RPVs. The key part of the testing is focussed on the determination of the reference temperature T0 of the Master Curve (MC) approach following the ASTM standard E1921 to determine the facture toughness, and how it degrades under neutron irradiation and is recovered by thermal annealing. Other than that the mentioned test results include Charpy-V and tensile test results. Following results have been determined: ā€¢ The mitigation of the neutron embrittlement of the weld and base metal by recovery annealing could be confirmed. ā€¢ KJc values of the weld metals generally followed the course of the MC though with a large scatter. ā€¢ There was a large variation in the T0 values evaluated across the thickness of the multilayered welding seams. ā€¢ The T0 measured on T-S oriented SE(B) specimens from different thickness locations of the welding seams strongly depended on the intrinsic structure along the crack front. ā€¢ The reference temperature RT0 determined according to the ā€œUnified Procedure for Lifetime Assessment of Components and Piping in WWER NPPs - VERLIFEā€ and the fracture toughness lower bound curve based thereon are applicable on the investigated weld metals. ā€¢ A strong scatter of the fracture toughness KJc values of the recovery annealed and re-irradiated and the irradiated base metal of Unit 1 and 4, respectively is observed with clearly more than 2% of the values below the MC for 2% fracture probability. The application of the multimodal MC-based approach was more suitable and described the temperature dependence of the KJc values in a satisfactory manner. ā€¢ It was demonstrated that T0 evaluated according to the SINTAP MC extension represented the brittle fraction of the data sets and is therefore suitable for the nonhomogeneous base metal. ā€¢ The efficiency of the large-scale thermal annealing of the Greifswald WWER 440/V230 Unit 1 and 2 RPVs could be confirmed

    CAN IBEX IDENTIFY VARIATIONS IN THE GALACTIC ENVIRONMENT OF THE SUN USING ENERGETIC NEUTRAL ATOMS?

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    The Interstellar Boundary Explorer (IBEX) spacecraft is providing the first all-sky maps of the energetic neutral atoms (ENAs) produced by charge exchange between interstellar neutral Ho atoms and heliospheric solar wind and pickup ions in the heliosphere boundary regions. The "edge" of the interstellar cloud presently surrounding the heliosphere extends less than 0.1 pc in the upwind direction, terminating at an unknown distance, indicating that the outer boundary conditions of the heliosphere could change during the lifetime of the IBEX satellite. Using reasonable values for future outer heliosphere boundary conditions, ENA fluxes are predicted for one possible source of ENAs coming from outside of the heliopause. The ENA-production simulations use three-dimensional MHD plasma models of the heliosphere that include a kinetic description of neutrals and a Lorentzian distribution for ions. Based on this ENA-production model, it is then shown that the sensitivities of the IBEX 1.1 keV skymaps are sufficient to detect the variations in ENA fluxes that are expected to accompany the solar transition into the next upwind cloud. Approximately 20% of the IBEX 1.1 keV pixels appear capable of detecting the predicted model differences at the 3Ļƒ level, with these pixels concentrated in the Ribbon region. Regardless of the detailed ENA production model, the success of the modeled B centerdot R ~ 0 directions in reproducing the Ribbon locus, together with our results, indicates that the Ribbon phenomenon traces the variations in the heliosphere distortion caused by the relative pressures of the interstellar magnetic and gaseous components.United States. National Aeronautics and Space Administration (NASA IBEX mission, Explorer Program, grant NNX09AG63G

    Identification of regulatory variants associated with genetic susceptibility to meningococcal disease.

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    Non-coding genetic variants play an important role in driving susceptibility to complex diseases but their characterization remains challenging. Here, we employed a novel approach to interrogate the genetic risk of such polymorphisms in a more systematic way by targeting specific regulatory regions relevant for the phenotype studied. We applied this method to meningococcal disease susceptibility, using the DNA binding pattern of RELA - a NF-kB subunit, master regulator of the response to infection - under bacterial stimuli in nasopharyngeal epithelial cells. We designed a custom panel to cover these RELA binding sites and used it for targeted sequencing in cases and controls. Variant calling and association analysis were performed followed by validation of candidate polymorphisms by genotyping in three independent cohorts. We identified two new polymorphisms, rs4823231 and rs11913168, showing signs of association with meningococcal disease susceptibility. In addition, using our genomic data as well as publicly available resources, we found evidences for these SNPs to have potential regulatory effects on ATXN10 and LIF genes respectively. The variants and related candidate genes are relevant for infectious diseases and may have important contribution for meningococcal disease pathology. Finally, we described a novel genetic association approach that could be applied to other phenotypes

    Investigation of decommissioned reactor pressure vessels of the nuclear power plant Greifswald

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    The investigation of reactor pressure vessel (RPV) material from the decommissioned Greifswald nuclear power plant representing the first generation of Russian-type WWER-440/V-230 reactors offers the opportunity to evaluate the real toughness response. The Greifswald RPVs of 4 units represent different material conditions as follows: ā€¢ Irradiated (Unit 4), ā€¢ irradiated and recovery annealed (Units 2 and 3), and ā€¢ irradiated, recovery annealed and re-irradiated (Unit1). The recovery annealing of the RPV was performed at a temperature of 475Ā° for about 152 hours and included a region covering Ā±0.70 m above and below the core beltline welding seam. Material samples of a diameter of 119 mm called trepans were extracted from the RPV walls. The research program is focused on the characterisation of the RPV steels (base and weld metal) across the thickness of the RPV wall. This report presents test results measured on the trepans from the beltline welding seam No. SN0.1.4. and forged base metal ring No. 0.3.1. of the Units 1 2 and 4 RPVs. The key part of the testing is focussed on the determination of the reference temperature T0 of the Master Curve (MC) approach following the ASTM standard E1921 to determine the facture toughness, and how it degrades under neutron irradiation and is recovered by thermal annealing. Other than that the mentioned test results include Charpy-V and tensile test results. Following results have been determined: ā€¢ The mitigation of the neutron embrittlement of the weld and base metal by recovery annealing could be confirmed. ā€¢ KJc values of the weld metals generally followed the course of the MC though with a large scatter. ā€¢ There was a large variation in the T0 values evaluated across the thickness of the multilayered welding seams. ā€¢ The T0 measured on T-S oriented SE(B) specimens from different thickness locations of the welding seams strongly depended on the intrinsic structure along the crack front. ā€¢ The reference temperature RT0 determined according to the ā€œUnified Procedure for Lifetime Assessment of Components and Piping in WWER NPPs - VERLIFEā€ and the fracture toughness lower bound curve based thereon are applicable on the investigated weld metals. ā€¢ A strong scatter of the fracture toughness KJc values of the recovery annealed and re-irradiated and the irradiated base metal of Unit 1 and 4, respectively is observed with clearly more than 2% of the values below the MC for 2% fracture probability. The application of the multimodal MC-based approach was more suitable and described the temperature dependence of the KJc values in a satisfactory manner. ā€¢ It was demonstrated that T0 evaluated according to the SINTAP MC extension represented the brittle fraction of the data sets and is therefore suitable for the nonhomogeneous base metal. ā€¢ The efficiency of the large-scale thermal annealing of the Greifswald WWER 440/V230 Unit 1 and 2 RPVs could be confirmed

    Investigation of decommissioned reactor pressure vessels of the nuclear power plant Greifswald

    No full text
    The investigation of reactor pressure vessel (RPV) material from the decommissioned Greifswald nuclear power plant representing the first generation of Russian-type WWER-440/V-230 reactors offers the opportunity to evaluate the real toughness response. The Greifswald RPVs of 4 units represent different material conditions as follows: ā€¢ Irradiated (Unit 4), ā€¢ irradiated and recovery annealed (Units 2 and 3), and ā€¢ irradiated, recovery annealed and re-irradiated (Unit1). The recovery annealing of the RPV was performed at a temperature of 475Ā° for about 152 hours and included a region covering Ā±0.70 m above and below the core beltline welding seam. Material samples of a diameter of 119 mm called trepans were extracted from the RPV walls. The research program is focused on the characterisation of the RPV steels (base and weld metal) across the thickness of the RPV wall. This report presents test results measured on the trepans from the beltline welding seam No. SN0.1.4. and forged base metal ring No. 0.3.1. of the Units 1 2 and 4 RPVs. The key part of the testing is focussed on the determination of the reference temperature T0 of the Master Curve (MC) approach following the ASTM standard E1921 to determine the facture toughness, and how it degrades under neutron irradiation and is recovered by thermal annealing. Other than that the mentioned test results include Charpy-V and tensile test results. Following results have been determined: ā€¢ The mitigation of the neutron embrittlement of the weld and base metal by recovery annealing could be confirmed. ā€¢ KJc values of the weld metals generally followed the course of the MC though with a large scatter. ā€¢ There was a large variation in the T0 values evaluated across the thickness of the multilayered welding seams. ā€¢ The T0 measured on T-S oriented SE(B) specimens from different thickness locations of the welding seams strongly depended on the intrinsic structure along the crack front. ā€¢ The reference temperature RT0 determined according to the ā€œUnified Procedure for Lifetime Assessment of Components and Piping in WWER NPPs - VERLIFEā€ and the fracture toughness lower bound curve based thereon are applicable on the investigated weld metals. ā€¢ A strong scatter of the fracture toughness KJc values of the recovery annealed and re-irradiated and the irradiated base metal of Unit 1 and 4, respectively is observed with clearly more than 2% of the values below the MC for 2% fracture probability. The application of the multimodal MC-based approach was more suitable and described the temperature dependence of the KJc values in a satisfactory manner. ā€¢ It was demonstrated that T0 evaluated according to the SINTAP MC extension represented the brittle fraction of the data sets and is therefore suitable for the nonhomogeneous base metal. ā€¢ The efficiency of the large-scale thermal annealing of the Greifswald WWER 440/V230 Unit 1 and 2 RPVs could be confirmed

    Der Beitrag des IuK-Sektors zur Verbesserung der Innovations- und Wettbewerbsfaehigkeit der inlaendischen Produktion und Beschaeftigung Strukturberichterstattung 1996-1998; neue Informations- und Kommunikationstechnologien, Tertiarisierung und Globalisierung -Herausforderungen fuer den Strukturwandel

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    'Die neuen Informations- und Kommunikationstechnologien (IuK-Technologien) beeinflussen die Wirtschaft in vielfaeltiger Hinsicht. Das Ausmass der Wirkungen haengt zum einen von der Innovations- und Wettbewerbsfaehigkeit der Anbieter neuer Informationsund Kommunikationsprodukte sowie -dienstleistungen ab. Zum anderen werden sie bestimmt durch die Innovationsfaehigkeit aller Unternehmen, die IuK als Instrument zur Effizienzsteigerung und zur qualitativen Verbesserung ihres Angebotes einsetzen koennen. Durch die IuK-Technologien wird die Tertiarisierung in der Wirtschaft gefoerdert, gleichzeitig hat die Globalisierung durch die qualitativen und quantitativen Fortschritte der IuK-Technologie wichtige Impulse erhalten. Ziel des ersten Zwischenberichtes zur Strukturberichterstattung ist es, eine Bestandsaufnahme des IuK-Sektors durchzufuehren und dessen Beitrag zur Wettbewerbs- und Innovationsfaehigkeit der deutschen Wirtschaft herauszuarbeiten. Im ersten Teil wird die Entwicklung des direkten Beitrags des IuK-Sektors zu Produktion, Wertschoepfung und Beschaeftigung untersucht. Dabei wird auch die Frage der Wettbewerbsfaehigkeit der Einzelbereiche im Hinblick auf die Patentaktivitaet und den Aussenhandel analysiert. Der zweite Teil der Untersuchung behandelt den indirekten Einluss von IuK auf die Wettbewerbsfaehigkeit der Wirtschaft. Dabei wird ein Indikatorensystem erarbeitet, das den unterschiedlichen Einfluessen von IuK-Technologien Rechnung traegt.' (Autorenreferat)SIGLEAvailable from IAB-91-DL30..-20 BH 806 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman
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