Sökning: "MELCOR"

Visar resultat 1 - 5 av 6 avhandlingar innehållade ordet MELCOR.

  1. 1. 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

  3. 2. Development and Application of Uncertainty Analysis Approaches for MELCOR Simulations of Severe Accidents

    Författare :Wanhong Wang; Weimin Ma; Florian Fichot; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Severe accident; MELCOR; uncertainty analysis; Wilks’ method; Bootstrapped artificial neural network; deterministic sampling method; 95 95 tolerance limit.; Svåra haverier; MELCOR; osäkerhetsanalys; Wilks’ metod; artificiella neuronnät; deterministiska urvalsmetoder; 95 95-toleransgränser.;

    Sammanfattning : The contemporary needs in advancing safety analysis methods and the increasing stringency in light water reactor (LWR) safety in the post-Fukushima era require more advanced and systematical approaches for severe accident analyses. The best estimate plus uncertainty (BEPU) methods are among such approaches and have been widely used for deterministic safety analysis (DSA) of design basis accidents (DBAs). 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

  5. 4. Informing Severe Accident Management Guidelines for a Pressurized Water Reactor with MELCOR Simulations

    Författare :Nan Zhao; Sevostian Bechta; Jinho Song; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Severe accident management guidelines SAMG ; SAMG verification validation; numerical simulation; SAMG entry condition; SAMG actions; primary-side bleed feed.; Kärnenergiteknik; Nuclear Engineering;

    Sammanfattning : Severe accident management guidelines (SAMGs) play an important role in the hierarchical structure of the defense-in-depth (DiD) principle of reactor safety. Among different methods to verify and validate the effectiveness of SAMG on mitigating severe accident consequences, the approach of numerical simulations using best-estimate computer codes was extensively applied to evaluate the SAMG and SAM actions. LÄS MER

  7. 5. Input Calibration, Code Validation and Surrogate Model Development for Analysis of Two-phase Circulation Instability and Core Relocation Phenomena

    Författare :Viet-Anh Phung; Pavel Kudinov; Cristophe Demaziere; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Reactor system code; input calibration; code validation; surrogate model; two-phase circulation flow instability; in-vessel core relocation; genetic algorithm; artificial neural network; Reaktorsystemkod; indata kalibrering; kodvalidering; surrogatmodell; två-fas cirkulationsflöde; instabilitet; härdrelokering i reaktortanken; genetisk algoritm; artificiella neurala nätverk; Fysik; Physics;

    Sammanfattning : Code validation and uncertainty quantification are important tasks in nuclear reactor safety analysis. Code users have to deal with large number of uncertain parameters, complex multi-physics, multi-dimensional and multi-scale phenomena. LÄS MER