| 1. |
- Galusin, Sergey, 1985-, et al.
(författare)
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An approach to joint application of integrated deterministic-probabilistic safety analysis and PSA Level 2 to severe accident issues in Nordic BWRs
- 2016
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Ingår i: PSAM 2016 - 13th International Conference on Probabilistic Safety Assessment and Management2017. - : International Association for Probabilistic Safety Assessment and Management (IAPSAM).
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Konferensbidrag (refereegranskat)abstract
- In this paper we outline a conceptual approach for combined use of Probabilistic Safety Assessment (PSA) and Integrated Deterministic-Probabilistic Safety Assessment (IDPSA), considering Nordic Boiling Water Reactor (BWR) severe accident issues (specifically ex-vessel steam explosion and debris bed coolability) for illustration.We describe a conceptual approach based on post processing of the results generated by IDPSA to update the “static” Boolean structures in the standard PSA representation. The challenge in the evaluation is to retain the failure combinations from the PSA to allow for component importance evaluation, to be able to perform the calculations in a reasonable time frame and to use all relevant information from the IDPSA results.We discuss the approaches for determination of the event space (for IDPSA analysis) which is consistent with PSA damage states from PSA-L1 and L2. We also discuss application of post processing approach for analysis of huge amount of data generated in the process of uncertainty space exploration, which is difficult to use directly in decision making process including incorporation of such data into PSA framework, to update structures of “static” Boolean structures in standard PSA. Using data post processing approach we can significantly reduce amount of information which represents results from IDPSA analysis.
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| 2. |
- Krcal, Jan, et al.
(författare)
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Scalable Analysis of Fault Trees with Dynamic Features
- 2015
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Ingår i: 2015 45Th Annual IEEE/IFIP International Conference On Dependable Systems And Networks. - 9781479986293 ; , s. 89-100
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Konferensbidrag (refereegranskat)abstract
- Fault trees constitute one of the essential formalisms for static safety analysis of various industrial systems. Dynamic fault trees (DFT) enrich the formalism by time-dependent behavior, e.g., repairs or functional dependencies. Analysis of DFT is so far limited to substantially smaller models than those required for, e.g., nuclear power plants. We propose a fault tree formalism that combines both static and dynamic features, called SD fault trees. It gives the user the freedom to express each equipment failure either statically, without modeling temporal information, or dynamically, allowing repairs and other timed interdependencies. We introduce an analysis algorithm for an important subclass of SD fault trees. The algorithm (1) scales similarly to static algorithms and (2) allows for a more realistic analysis compared to static algorithms as it takes into account temporal interdependencies. Finally, we demonstrate the applicability of the method by an experimental evaluation on fault trees of nuclear power plants.
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