A framework for assessment of severe accident management effectiveness in Nordic BWR plants
2014 (English)Conference paper (Refereed)
In the case of severe accident in Nordic boiling water reactors (BWR), core melt is poured into a deep pool of water located under the reactor. The severe accident management (SAM) strategy involves complex and coupled physical phenomena of melt-coolant-structure interactions sensitive to the transient accident scenarios. Success of the strategy is contingent upon melt release conditions from the vessel which determine (i) if corium debris bed is coolable, and (ii) potential for energetic steam explosion. The goal of this work is to develop a risk-oriented accident analysis framework for quantifying conditional threats to containment integrity for a Nordic-type BWR. The focus is on the process of refining the treatment and components of the framework to achieve (i) completeness, (ii) consistency, and (iii) transparency in the review of the analysis and its results. A two-level coarse-fine iterative refinement process is proposed. First, fine-resolution but computationally expensive methods are used in order to develop computationally efficient surrogate models. Second, coupled modular framework is developed connecting initial plant damage states with respective containment failure modes. Systematic statistical analysis is carried out to identify the needs for refinement of detailed methods, surrogate models, data and structure of the framework to reduce the uncertainty, and increase confidence and transparency in the risk assessment results.
Place, publisher, year, edition, pages
Other Engineering and Technologies not elsewhere specified
IdentifiersURN: urn:nbn:se:kth:diva-164083ScopusID: 2-s2.0-84925071190OAI: oai:DiVA.org:kth-164083DiVA: diva2:803394
12th International Probabilistic Safety Assessment and Management Conference, PSAM 2014; Sheraton WaikikiHonolulu; United States; 22 June 2014 - 27 June 2014
QC 201504162015-04-132015-04-132015-04-16Bibliographically approved