Search for dissertations about: "corium flow"

Showing result 6 - 10 of 10 swedish dissertations containing the words corium flow.

2. 6. Particulate Debris Spreading and Coolability

   Author : Simone Basso; Pavel Kudinov; Florian Fichot; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Self-leveling; debris bed; spreading; coolability; severe accident; probabilistic framework; Monte Carlo; uncertainty; sensitivity; Fysik; Physics;

   Abstract : In Nordic design of boiling water reactors, a deep water pool under the reactor vessel is employed for the core melt fragmentation and the long term cooling of decay heated corium debris in case of a severe accident. To assess the effectiveness of such accident management strategy the Risk-Oriented Accident Analysis Methodology has been proposed. READ MORE

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

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

   Abstract : 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. READ MORE

5. 8. Phenomenological and mechanistic modeling of melt-structure-water interactions in a light water reactor (LWR) severe accident

   Author : Anh Bui Viet; KTH; []
   Keywords : ;

   Abstract : Severe accidents in light water reactors have been the fotalpoint of much research, performed in the last two decades,aimed at understarrding the inherent physical phenomena and toevaluate proposed accident management schemes for mitigatingthe consequences of such accidents. Severe accident progressionand consequences, av the reactor core overheats and melts, areintimately related to the interactions of the melt with coolant(water) and structures. READ MORE

6. 9. Investigations of passive safety systems in LWRs : melt coolability with bottom coolant injection, light gas effects on a passive containment cooling system

   Author : Domenico Paladdino; KTH; []
   Keywords : ;

   Abstract : The key objectives in introducing passive features in thesafety systems for Light Water Reactor (LWR) are to increasetheir reliability, to simplify the design of the plants and toimprove performance and economics. Component and integralsystem tests in scaled facilities are required for optimizingthe design and for certification of these safety systems. READ MORE

7. 10. The Effective Convectivity Model for Simulation and Analysis of Melt Pool Heat Transfer in a Light Water Reactor Pressure Vessel Lower Head

   Author : Chi Thanh Tran; Tomas Lefvert; Harri Tuomisto; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; light water reactor; hypothetical severe accident; accident progression; accident scenario; core melt pool; heat transfer; turbulent natural convection; heat transfer coefficient; phase change; mushy zone; crust; lower plenum; analytical model; effective convectivity model; CFD simulation; Thermal energy engineering; Termisk energiteknik;

   Abstract : Severe accidents in a Light Water Reactor (LWR) have been a subject of intense research for the last three decades. The research in this area aims to reach understanding of the inherent physical phenomena and reduce the uncertainties in their quantification, with the ultimate goal of developing models that can be applied to safety analysis of nuclear reactors, and to evaluation of the proposed accident management schemes for mitigating the consequences of severe accidents. READ MORE