Sökning: "neutron irradiation"

Visar resultat 6 - 10 av 20 avhandlingar innehållade orden neutron irradiation.

  1. 6. First principles study of tungsten-based alloys: From defect thermodynamics to phase diagrams

    Författare :Leili Gharaee; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; structural materials; first-principles calculations.; point defects; tungsten alloys; irradiation;

    Sammanfattning : Nuclear fusion is a very attractive option for energy production as it is clean, safe and efficient. The major obstacle in construction of fusion power plants is the development of materials that can tolerate the extreme operational condition especially high-energy neutron flux. LÄS MER

  3. 7. Effects of Irradiation and Thermal Ageing on the Nanoscale Chemistry of Steel Welds

    Författare :Kristina Lindgren; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; spinodal decomposition; thermal ageing; low alloy steel; reactor pressure vessel; irradiation damage; atom probe tomography; core barrel; clustering;

    Sammanfattning : Structural materials of nuclear power plants degrade during operation due to thermal ageing and irradiation from the reactor core. Effects on the materials are an increase in hardness and tensile strength, and a decrease in ductility and fracture toughness, i. e. embrittlement. LÄS MER

  4. 8. 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

  5. 9. Transmutation of Americium in Fast Neutron Facilities

    Författare :Youpeng Zhang; Janne Wallenius; Sandra Dulla; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; americium; transmutation; fast reactor; Nuclear physics; Kärnfysik; TECHNOLOGY; TEKNIKVETENSKAP;

    Sammanfattning : In this thesis, the feasibility to use a medium sized sodium cooled fast reactor fully loaded with MOX fuel for efficient transmutation of americium is investigated by simulating the safety performance of a BN600-type fast reactor loaded with different fractions of americium in the fuel, using the safety parameters obtained with the SERPENT Monte Carlo code. The focus is on americium mainly due to its long-term contribution to the radiotoxicity of spent nuclear fuel and its deterioration on core's safety parameters. LÄS MER

  7. 10. Atomic Scale Degradation of Zirconium Alloys for Nuclear Applications

    Författare :Gustav Sundell; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Irradiation damage; Hydrogen microanalysis; Hydrogen pick-up; Zirconium alloys; Atom probe tomography; Corrosion;

    Sammanfattning : Due to their low thermal neutron capture cross-section, zirconium alloys are widely used in the nuclear industry as fuel cladding and for structural components. The lifetime of the fuel assemblies in the reactors is primarily dictated by the ability of the cladding to withstand oxidation and hydrogen pick-up from the coolant water and radiation damage induced by the neutron flux. LÄS MER