Sökning: "reactor pressure vessel"

Visar resultat 6 - 10 av 14 avhandlingar innehållade orden reactor pressure vessel.

  1. 6. Multiscale modeling of atomic transport phenomena in ferritic steels

    Författare :Luca Messina; Pär Olsson; Nils Sandberg; Pål Efsing; Pascal Bellon; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; diffusion; impurities; iron; metals; kinetic Monte Carlo; ab initio; mean field; defects; embrittlement; reactor pressure vessel; neural networks; Fysik; Physics;

    Sammanfattning : Defect-driven transport of impurities plays a key role in the microstructure evolution of alloys, and has a great impact on the mechanical properties at the macroscopic scale. This phenomenon is greatly enhanced in irradiated materials because of the large amount of radiation-induced crystal defects (vacancies and interstitials). LÄS MER

  3. 7. CFD Study of Molten Pool Convection in a Reactor Vessel during a Severe Accident

    Författare :Boshen Bian; Walter Villanueva; Sevostian Bechta; Weimin Ma; Shuisheng He; KTH; []
    Nyckelord :Severe accident; Corium; Natural convection; Turbulence; Scalability; Direct numerical simulation DNS .; Svåra haverier; härdsmälta; naturlig konvektion; turbulens; skalbarhet; direkt numerisk simulering DNS .; Physics; Fysik;

    Sammanfattning : During severe accidents in nuclear reactors, the core and internal structures can melt down and relocate into the reactor pressure vessel (RPV) lower head (LH) forming there a stratified molten corium pool. The pool generally consists of superheated oxidic and metallic liquid layers imposing thermo-mechanical loads on the RPV wall. LÄS MER

  4. 8. Analysis methodology for RBMK-1500 core safety and investigations on corium coolabiblty during a LWR sever accidnet

    Författare :Audrius Jasiulevicius; KTH; []
    Nyckelord :RBMK. Light water reactor. Core analysis; transient analysis; reactor dynamics;

    Sammanfattning : This thesis presents the work involving two broad aspectswithin the field of nuclear reactor analysis and safety. Theseare: - development of a fully independent reactor dynamics andsafety analysis methodology of the RBMK-1500 core transientaccidents and - experiments on the enhancement of coolabilityof a particulate bed or a melt pool due to heat removal throughthe control rod guide tubes. LÄS MER

  5. 9. MELCOR Capability Development for Simulation of Debris Bed Coolability

    Författare :Yangli Chen; Weimin Ma; Michael Buck; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Severe accident; coolability; MELCOR; COCOMO; surrogate modeling; coupling codes; uncertainty analysis.; Kärnenergiteknik; Nuclear Engineering;

    Sammanfattning : The severe accident management (SAM) strategy for a Nordic boiling water reactor (BWR) employs cavity flooding prior to vessel failure, so that the core melt (corium) discharged from the vessel could fragment and form a particulate debris bed. The key to the success of this SAM strategy is the coolability of ex-vessel debris beds. LÄS MER

  7. 10. Pedestal structure and stability in JET-ILW and comparison with JET-C

    Författare :Estera Stefanikova; Lorenzo Frassinetti; Per Brunsell; Joelle Mailloux; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; JET; Thomson scattering; pedestal; pedestal position; pedestal stability; Europed modelling; Physics; Fysik;

    Sammanfattning : Controlled thermonuclear fusion offers a promising concept for safe and sustainable production of electrical energy. However, there are still many issues to be investigated on the way to a commercial fusion reactor. An important point for detailed studies is connected to wall materials surrounding hot thermonuclear plasma. LÄS MER