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Showing result 1 - 5 of 10 swedish dissertations matching the above criteria.

2. 1. Computation of convective two- and three-dimensional flow patterns with phase change

   Author : George Fileas; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; nuclear reactor safety; corium flow; finite-difference principle; 3-D computations; solidification; long-term heat storage;

   Abstract : .... READ MORE

4. 2. CFD Study of Molten Pool Convection in a Reactor Vessel during a Severe Accident

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

   Abstract : 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. READ MORE

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

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

   Abstract : 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. READ MORE

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

   Author : Viet-Anh Phung; Pavel Kudinov; Cristophe Demaziere; KTH; []
   Keywords : 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;

   Abstract : 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. READ MORE

7. 5. Study on Metallic Melt Coolant Interactions and Debris Bed Formation in a Water Pool

   Author : Yan Xiang; Weimin Ma; Sevostian Bechta; Andrei A. Komlev; Michael Buck; KTH; []
   Keywords : 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;

   Abstract : 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. READ MORE