123 research outputs found
Shorted operators: An application in potential theory
AbstractOn nested fractals a “Laplacian” can be constructed as a scaled limit of difference operators. The appropriate scaling and starting configuration are given by a nonlinear, finite dimensional eigenvalue problem. We study it as a fixed point problem using Hilbert's projective metric on cones, a nonlinear generalization of the Perron-Frobenius theory of nonnegative matrices. The nonlinearity arises from a map Φ known as the shorted operator. Potential theoretic notions and results apply to it, since it acts on a cone of discrete “Laplacians” or difference operators. Usually, Φ is considered on the larger cone of positive semidefinite operators. We are able to take advantage of the more specific structure of the reduced domain because several properties of Φ are local. Results are possible with respect to continuity, concavity, the Fréchet derivative, invariant subcones, the geometry of these cones, and the contraction of Hilbert's metric
Monte-Carlo based investigation of individual dosimetry in deep geological repository for high-level nuclear waste with consideration of realistic body postures
Final Workshop Proceedings of the Collaborative Project "Fast / Instant Release of Safety Relevant Radionuclides from Spent Nuclear Fuel" (7th EC FP CP FIRST-Nuclides), Karlsruhe 01 - 02 September 2014 (KIT Scientific Reports ; 7716)
The EURATOM FP7 Collaborative Project “Fast / Instant Release of Safety Relevant Radionuclides from Spent Nuclear Fuel (CP FIRST-Nuclides)” improved significantly the understanding of the mobilization of dose-dominating radionuclides from high burnup spent nuclear UO₂ fuels. The data are decisive for safety analysis for deep geological nuclear waste repositories
Radionuclide Source Term for Irradiated Fuel from Prototype, Research and Education Reactors, for Waste Forms with Negligible Heat Generation and for Uranium Tails (KIT Scientific Reports ; 7635)
Radionuclide source terms are derived for different disposal options of a potential final repository in the salt dome Gorleben. The geochemical conditions are analyzed under the precondition that NaCl, MgCl2- or CaCl2-rich solutions are present. Kinetic and thermodynamic mobilization/retention and the influence of temperatures are discussed. Upper limit concentrations for the radionuclides Am, Th, U, Np, Pu, Tc, Zr and rare earth elements are derived for the simplified scenarios
2nd Annual Workshop Proceedings of the Collaborative Project "Fast / Instant Release of Safety Relevant Radionuclides from Spent Nuclear Fuel" (7th EC FP CP FIRST-Nuclides), Antwerp 05 - 07 November 2013 (KIT Scientific Reports ; 7676)
This proceedings document the 2nd Annual Workshop of the EURATOM FP7 Collaborative Project FIRST-Nuclides (Fast / Instant Release of Safety Relevant Radionuclides from Spent Nuclear Fuel). 10 beneficiaries and 11 associated groups participated in the 2nd Annual Workshop, as well as interested externals. The key purpose of the proceedings is documenting the scientific outcome of the FIRST-Nuclides project. This is covered by scientific/technical contributions of the partners. It includes reports by the Associated Groups and the Topical Session
1st Annual Workshop Proceedings of the Collaborative Project "Fast / Instant Release of Safety Relevant Radionuclides from Spent Nuclear Fuel" (7th EC FP CP FIRST-Nuclides), Budapest 09 - 11 October 2012 (KIT Scientific Reports ; 7639)
These proceedings document the scientific-technical progress of the 1st year of the European project FIRST-Nuclides. The project is established with the overall objective to provide for improved understanding of the fast / instantly released radionuclides from high burn-up spent nuclear fuel (HBU-SNF) under conditions of geological disposal. 14 HBU-SNF samples, discharged from various European and US American light water reactors, are characterized and prepared for experimental investigations
Volatile activation and fission products 36Cl and 129I present in fuel-cladding interfaces of spent UO2 fuel - separation method and first results
Solid-liquid equilibria of Sorel phases and Mg (OH)₂ in the system Na-Mg-Cl-OH-H₂O. Part I: experimental determination of OH⁻ and H⁺ equilibrium concentrations and solubility constants at 25°C, 40°C, and 60°C
Sorel phases are the binder phases of the magnesia building material (Sorel cement/concrete) and of special concern for the construction of long-term stable geotechnical barriers in repositories for radioactive waste in rock salt, as potentially occurring brines are expected to contain MgCl2. Sorel phases, in addition to Mg(OH)2, are equally important as pH buffers to minimize solubility and potential mobilization of radionuclides in brine systems. In order to obtain a detailed database of the relevant solid-liquid equilibria and the related pHm values of the equilibrium solutions, extensive experimental investigations were carried out. Solid phase formation was studied by suspending MgO and Mg(OH)2 in NaCl saturated MgCl2-solutions at 25°C. Mg(OH)2 and the 3-1-8 Sorel phase were identified as the stable solid phases, while the 5-1-8 Sorel phase is metastable. Equilibration at 40°C did not lead to any solid phase changes. Both OH− and H+ equilibrium concentrations were analyzed as a function of MgCl2 concentration at 25°C and 40°C. In addition to our already published solid-liquid equilibria for the ternary system Mg-Cl-OH-H2O (25°C–120°C), the equilibrium H+ concentrations (pHm) determined at 25°C, 40°C and 60°C are now reported. Analyzing these data together with known ion-interaction Pitzer coefficients, the solubility constants for Mg(OH)2 and the 3-1-8 phase at these three temperatures, for the metastable 5-1-8 phase at 25°C and for the 2-1-4 phase at 60°C have been consistently calculated
Bilanz der Treffen des Europäischen Rats sowie der Maßnahmen gegen den Terrorismus seit dem 11. September
Der vorliegende Beitrag gibt einen Überblick über die Treffen des Europäischen Rates seit dem 11. September 2001 unter besonderer Berücksichtigung der Maßnahmen gegen den Terrorismus. Bereits am 21. September 2001 kamen die Staats- und Regierungschefs der EU zu einer außerordentlichen Tagung zusammen und verabschiedeten einen Aktionsplan zur Bekämpfung von Terrorismus, der auch von den Beitrittskandidaten unterstützt wird. Am 19. Oktober 2001 fand ein informelles Ratstreffen in Gent statt. Ursprünglich war geplant, das in der Mitte der belgischen Ratspräsidentschaft stattfindende Treffen in Gent einem freien Meinungsaustausch über die Zukunft Europas zu widmen. Aus gegebenem Anlass war dies allerdings nur eines der Themen der Zusammenkunft. Diese stand weitgehend im Zeichen der Anschläge in den USA und der am 7. Oktober 2001 begonnenen Militäraktionen der Vereinigten Staaten in Afghanistan. Am 20. Oktober 2001 fand die erweitere Europa-Konferenz in Brüssel statt. Neben den 15 EU-Mitgliedstaaten und den 13 Beitrittskandidaten sowie der Schweiz, Norwegen und Island nahmen aus aktuellem Anlass auch Russland, die Ukraine und Moldowa teil. Die Teilnehmer bekannten sich zum Aktionsplan der EU zur Bekämpfung des Terrorismus und versicherten, im Kampf gegen den Terrorismus die Menschenrechte und rechtsstaatliche Prinzipien zu achten. In der Folge des Aktionsplanes vom 21. September 2001 wurden durch die Kommission, die Fachräte, den Allgemeinen Rat und den Europäischen Rat etwa 80 Einzelmaßnahmen in den Bereichen Justiz und Inneres, Zivilschutz, Verkehr und Flugsicherheit, Finanzen/Wirtschaft, Gemeinsame Außen- und Sicherheitspolitik und Humanitäre Hilfe auf den Weg gebracht. (ICD
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