Sökning: "plutonium"

Visar resultat 21 - 25 av 38 avhandlingar innehållade ordet plutonium.

  1. 21. On the Diluent and Solvent Effects in Liquid-Liquid Extraction Systems based on Bis-triazine-bipyridine (BTBP) ligands

    Författare :Elin Löfström Engdahl; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Solvent effects; Diluent effects; GANEX; Interfacial tension; Density;

    Sammanfattning : Used nuclear fuel is dangerous for mankind and her environment for a long time. If however, the minor actinides together with uranium and plutonium could be transmuted, i.e. transformed, into more shortlived or stable isotopes the volume of the waste could be significantly reduced together with a reduction in the radiotoxicity. LÄS MER

  3. 22. From the Electronic Structure of Point Defects to Functional Properties of Metals and Ceramics

    Författare :David Andersson; Börje Johansson; Pavel Korzhavyi; Benjamin Burton; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; first principles; ab initio; density functional theory; Calphad; point defects; diffusion; solid electrolytes; oxygen storage materials; Material physics with surface physics; Materialfysik med ytfysik;

    Sammanfattning : Point defects are an inherent part of crystalline materials and they influence important physical and chemical properties, such as diffusion, hardness, catalytic activity and phase stability. Increased understanding of point defects enables us to tailor the defect-related properties to the application at hand. LÄS MER

  4. 23. Neutronic and burnup studies of accelerator-driven systems dedicated to nuclear waste transmutation

    Författare :Kamil Tucek; Jan Wallenius; Massimo Salvatores; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physics; Fysik; Physics; Fysik;

    Sammanfattning : Partitioning and transmutation of plutonium, americium, and curium is inevitable if the radiotoxic inventory of spent nuclear fuel is to be reduced by more than a factor of 100. But, admixing minor actinides into the fuel severely degrades system safety parameters, particularly coolant void reactivity, Doppler effect, and (effective) delayed neutron fractions. LÄS MER

  5. 24. Why Faster is Better : On Minor Actinide Transmutation in Hard Neutron

    Författare :Daniel Westlén; Jan Wallenius; Marc Delpech; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; nuclear physics; nuclear engineering; Atomic physics; Atomfysik;

    Sammanfattning : In this thesis, options for efficient transmutation of transuranium elements are discussed. The focus is on plutonium, americium and curium mainly because of their long-term contribution to the radiotoxicity of spent nuclear fuel. Two innovative helium-cooled core designs are proposed, dedicated to the transmutation of actinides. LÄS MER

  7. 25. Generalised Campbell formulae for compound Poisson processes with applications in nuclear safeguards

    Författare :Lajos Nagy; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; passive non-destructive assay; fissile material assay; multiplicity counting;

    Sammanfattning : Multiplicity counting is a widely used non-destructive assay method for estimating unknown parameters (primarily the mass) of samples of spontaneously fissioning materials (e.g. plutonium). Traditionally, measurements are performed with thermal neutron detectors operating in pulse counting mode. LÄS MER