Sökning: "Severe accident scenario"

Visar resultat 1 - 5 av 8 avhandlingar innehållade orden Severe accident scenario.

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

   Författare :Hongdi Wang; Walter Villanueva; Sevostian Bechta; Weimin Ma; Artem Kulachenko; Michael Fitzpatrick; KTH; []
   Nyckelord :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;

   Sammanfattning : 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. LÄS MER

5. 4. 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

7. 5. Formation, partitioning and interactions of organic iodides under severe nuclear accident conditions

   Författare :Sabrina Tietze; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Epoxy paint; Methyl iodide; Iodine source term; Organic iodides; Severe nuclear accidents;

   Sammanfattning : During severe nuclear reactor accidents such as Chernobyl or Fukushima large amounts of radioactive iodine can be released in form of inorganic and organic iodine species into the environment. Volatile radioactive iodine species are harmful to human health when inhaled. LÄS MER