Sökning: "hypothetical severe accident"

Visar resultat 1 - 5 av 7 avhandlingar innehållade orden hypothetical severe accident.

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

   Författare :Chi Thanh Tran; Truc-Nam Dinh; Florian Fichot; KTH; []
   Nyckelord :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;

   Sammanfattning : 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. LÄS MER

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

   Författare :Chi Thanh Tran; Tomas Lefvert; Harri Tuomisto; KTH; []
   Nyckelord :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;

   Sammanfattning : 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. LÄS MER

4. 3. On Fuel Coolant Interactions and Debris Coolability in Light Water Reactors

   Författare :Sachin Thakre; Weimin Ma; Florian Fichot; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; severe accident; fuel-coolant interactions; melt jet fragmentation; steam explosion; debris bed coolability; uncertainty analysis; Energiteknik; Energy Technology;

   Sammanfattning : During the case of a hypothetical severe accident in a light water reactor, core damage may occur and molten fuel may interact with water resulting in explosive interactions. A Fuel-Coolant Interactions (FCI) consists of many complex phenomena whose characteristics determine the energetics of the interactions. LÄS MER

5. 4. 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

7. 5. Valuation and pricing of traffic safety

   Författare :Gunnar Lindberg; Lars Hultkrantz; Olof Johansson-Stenman; Örebro universitet; []
   Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; Value of statistical life; Marginal cost pricing; External cost; Risk elasticity; Pricing policies; Traffic accidents; Railway accidents; Heavy goods vehicle accidents; Economics; Nationalekonomi; Economics; Nationalekonomi;

   Sammanfattning : This thesis consists of six essays covering the topic of valuation and pricing of accidents. In the first essay a theory of the external marginal cost of accidents is presented. The external cost is dependent on the value of statistical life, the proportion internal cost and the so called risk elasticity, i.e. LÄS MER