Sökning: "Grusbädd"

Hittade 3 avhandlingar innehållade ordet Grusbädd.

  1. 1. Numerical Investigations on Debris Bed Coolability and Mitigation Measures in Nordic Boiling Water Reactors

    Författare :Zheng Huang; Weimin Ma; Florian Fichot; KTH; []
    Nyckelord :Severe accident; Debris bed; Coolability; Quench; Oxidation; MEWA code; Coupled analysis; Svåra haverier; Grusbädd; Kylbarhet; Kylning; Oxidering; MEWA program; Kopplad analys; Physics; Fysik;

    Sammanfattning : This thesis is aiming at coolability assessment of particulate debris beds formed in hypothetical severe accidents of Nordic boiling water reactors (BWRs) which may employ either lower drywell flooding or control rod guide tubes (CRGT) cooling as severe accident management strategies. For this purpose, quench and cooling limit (dryout) of debris beds after their formation from fuel coolant interactions were investigated by numerical simulations using the MEWA code. LÄS MER

  3. 2. Study on Metallic Melt Coolant Interactions and Debris Bed Formation in a Water Pool

    Författare :Yan Xiang; Weimin Ma; Sevostian Bechta; Andrei A. Komlev; Michael Buck; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Severe accident; fuel coolant interactions; metallic melt; jet fragmentation; debris bed; CLSVOF.; Svåra haverier; interaktioner mellan bränsle och kylmedel; metallsmälta; jetfragmentering; grusbädd; CLSVOF; Kärnenergiteknik; Nuclear Engineering;

    Sammanfattning : To assess corium coolability during severe accidents of LWR, significant number of studies have been conducted previously to investigate the characteristics of debris beds formed from FCI due to fragmentation of molten corium and settlement of the fragments in a water pool. However, their focus has been placed on the oxidic component (UO2/ZrO2) of corium, while little attention has been paid to the debris bed formation due to FCI of the metallic component (Zr/Fe) of corium. LÄS MER

  4. 3. Development of Risk Oriented Accident Analysis Methodology for Assessment of Effectiveness of Severe Accident Management Strategy in Nordic BWR

    Författare :Sergey Galushin; Pavel Kudinov; Harri Tuomisto; KTH; []
    Nyckelord :Severe accident management; sensitivity; uncertainty; MELCOR; ROAAM; Svår haverihantering; känslighet och osäkerhetsanalys; MELCOR; ROAAM; Fysik; Physics;

    Sammanfattning : Nordic Boiling Water Reactor (BWR) design employs ex-vessel debris coolability as a severe accident management strategy (SAM). In case of a severe accident, the debris ejected from the vessel are expected to fragment, quench and form a debris bed, which is coolable by a natural circulation of water. LÄS MER