Search for dissertations about: "accident scenario"

Showing result 1 - 5 of 14 swedish dissertations containing the words accident scenario.

2. 1. Development, validation and application of an effective convectivity model for simulation of melt pool heat transfer in a light water reactor lower head

   Author : Chi Thanh Tran; Truc-Nam Dinh; Florian Fichot; KTH; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; 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.; Other physics; Övrig fysik;

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

4. 2. 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

5. 3. Thermo-mechanical Assessment of Reactor Pressure Vessels of Light Water Reactors During Severe Accidents

   Author : Hongdi Wang; Walter Villanueva; Sevostian Bechta; Weimin Ma; Artem Kulachenko; Michael Fitzpatrick; KTH; []
   Keywords : Severe accident scenario; reactor pressure vessel; in-vessel melt retention; failure analysis; finite element analysis; validations; Scenario för svåra haverier; reaktortank; in-vessel retention; feleffektsanalys; Finite Element Analyser; validering; Physics; Fysik;

   Abstract : The reactor pressure vessel (RPV) is one of the crucial safety barriers designed to isolate the reactor core, safeguarding against potential radioactive releases into the environment during a severe accident. The assessment of RPV behaviour and its failure is necessary to predict the characteristics of melt release into the reactor pit and succeeding ex-vessel accident progression. READ MORE

6. 4. Post Impact Vehicle Path Control in Multiple Event Accidents

   Author : Derong Yang; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Accident Analysis; Multiple-Event Accidents; Post Impact; Collision Avoidance; Optimal Path Control.; Vehicle Dynamics;

   Abstract : Recent statistics show that multiple-event accidents (MEAs) possess an increasing fraction of all vehicle traffic accidents. They are characterized by having at least one vehicle subjected to more than one harmful event, such as collision with another vehicle. MEAs now comprise approximately 25% of all passenger vehicle accidents. READ MORE

7. 5. Development and Application of Uncertainty Analysis Approaches for MELCOR Simulations of Severe Accidents

   Author : Wanhong Wang; Weimin Ma; Florian Fichot; KTH; []
   Keywords : 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.;

   Abstract : 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). READ MORE