Sökning: "Severe nuclear accident"

Visar resultat 6 - 10 av 30 avhandlingar innehållade orden Severe nuclear accident.

  1. 6. CFD Study of Molten Pool Convection in a Reactor Vessel during a Severe Accident

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

    Sammanfattning : 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. LÄS MER

  3. 7. 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

  4. 8. Informing Severe Accident Management Guidelines for a Pressurized Water Reactor with MELCOR Simulations

    Författare :Nan Zhao; Sevostian Bechta; Jinho Song; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Severe accident management guidelines SAMG ; SAMG verification validation; numerical simulation; SAMG entry condition; SAMG actions; primary-side bleed feed.; Kärnenergiteknik; Nuclear Engineering;

    Sammanfattning : Severe accident management guidelines (SAMGs) play an important role in the hierarchical structure of the defense-in-depth (DiD) principle of reactor safety. Among different methods to verify and validate the effectiveness of SAMG on mitigating severe accident consequences, the approach of numerical simulations using best-estimate computer codes was extensively applied to evaluate the SAMG and SAM actions. LÄS MER

  5. 9. 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

  7. 10. Tellurium Behavior and Management in the Liquid Phases in the Containment During a Severe Nuclear Reactor Accident

    Författare :Anna-Elina Pasi; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; severe nuclear reactor accident; fission product; source term; tellurium;

    Sammanfattning : No industry is immune to accidents; however, the consequences and the probability are the parameters to consider when assessing the risks. When considering nuclear power, two of the highest-level accidents have occurred during the course of the commercial use of nuclear energy. LÄS MER