Experience from Level 2 Site Risk Analysis for Nordic Power Plants

Jan-Erik Holmberg, Stefan Authén, Ola Bäckström, He Xuhong, Salvatore Massaiu, Tero Tyrväinen

    Research output: Chapter in Book/Report/Conference proceedingConference article in proceedingsScientificpeer-review

    Abstract

    The objective with the SITRON (SITe Risk On Nuclear installations) project has been to search for practical approaches for Nordic utilities to assess the site level risk. This paper presents the findings from the performance of level 2 PSA, i.e., the assessment of radioactive release risk from multiple units. Qualitatively, a multi-unit level 1 and 2 PSA are similar in terms of identifying dependencies. Level 2 PSA may bring some additional dependencies that are not relevant for level 1 PSA. Quantitatively, the difference in the used risk metrics can have some practical implications. In level 1 PSA, risk metrics are the frequencies of combinations of core damages (one, two, ..., all units). In level 2 PSA, risk metric is the frequency of a certain release category (small, large, early, late), which is determined by the aggregated release rather than number of releases. The need to quantify various accident sequences is thus much dependent on the applied safety goal for level 2 PSA. Further, pilot studies indicate that inter-unit dependencies in level 2 safety functions have less influence on results than inter-unit dependencies in level 1 safety functions.
    Original languageEnglish
    Title of host publicationProceedings of the 29th European Safety and Reliability Conference
    EditorsMichael Beer, Enrico Zio
    Place of PublicationSingapore
    PublisherResearch publishing services
    Pages3790-3797
    Number of pages8
    ISBN (Electronic)978-981-11-2724-3
    Publication statusPublished - Sep 2019
    MoE publication typeA4 Article in a conference publication
    Event29th European Safety and Reliability Conference - Welfenschloss, Hannover, Germany
    Duration: 22 Sep 201926 Sep 2019
    Conference number: 29
    https://esrel2019.org/#/

    Conference

    Conference29th European Safety and Reliability Conference
    Abbreviated titleESREL 2019
    CountryGermany
    CityHannover
    Period22/09/1926/09/19
    Internet address

    Fingerprint

    Risk analysis
    Power plants
    Accidents

    Keywords

    • site risk analysis
    • nuclear power plant
    • level 2 PSA
    • probabilistic safety assessment
    • probabilistic risk analysis
    • multi-unit
    • severe accident
    • risk metrics
    • human reliability analysis

    Cite this

    Holmberg, J-E., Authén, S., Bäckström, O., Xuhong, H., Massaiu, S., & Tyrväinen, T. (2019). Experience from Level 2 Site Risk Analysis for Nordic Power Plants. In M. Beer, & E. Zio (Eds.), Proceedings of the 29th European Safety and Reliability Conference (pp. 3790-3797). [0276] Singapore: Research publishing services.
    Holmberg, Jan-Erik ; Authén, Stefan ; Bäckström, Ola ; Xuhong, He ; Massaiu, Salvatore ; Tyrväinen, Tero. / Experience from Level 2 Site Risk Analysis for Nordic Power Plants. Proceedings of the 29th European Safety and Reliability Conference. editor / Michael Beer ; Enrico Zio. Singapore : Research publishing services, 2019. pp. 3790-3797
    @inproceedings{59d67f889d33428786dc6190e14bf97a,
    title = "Experience from Level 2 Site Risk Analysis for Nordic Power Plants",
    abstract = "The objective with the SITRON (SITe Risk On Nuclear installations) project has been to search for practical approaches for Nordic utilities to assess the site level risk. This paper presents the findings from the performance of level 2 PSA, i.e., the assessment of radioactive release risk from multiple units. Qualitatively, a multi-unit level 1 and 2 PSA are similar in terms of identifying dependencies. Level 2 PSA may bring some additional dependencies that are not relevant for level 1 PSA. Quantitatively, the difference in the used risk metrics can have some practical implications. In level 1 PSA, risk metrics are the frequencies of combinations of core damages (one, two, ..., all units). In level 2 PSA, risk metric is the frequency of a certain release category (small, large, early, late), which is determined by the aggregated release rather than number of releases. The need to quantify various accident sequences is thus much dependent on the applied safety goal for level 2 PSA. Further, pilot studies indicate that inter-unit dependencies in level 2 safety functions have less influence on results than inter-unit dependencies in level 1 safety functions.",
    keywords = "site risk analysis, nuclear power plant, level 2 PSA, probabilistic safety assessment, probabilistic risk analysis, multi-unit, severe accident, risk metrics, human reliability analysis",
    author = "Jan-Erik Holmberg and Stefan Auth{\'e}n and Ola B{\"a}ckstr{\"o}m and He Xuhong and Salvatore Massaiu and Tero Tyrv{\"a}inen",
    year = "2019",
    month = "9",
    language = "English",
    pages = "3790--3797",
    editor = "Michael Beer and Enrico Zio",
    booktitle = "Proceedings of the 29th European Safety and Reliability Conference",
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    Holmberg, J-E, Authén, S, Bäckström, O, Xuhong, H, Massaiu, S & Tyrväinen, T 2019, Experience from Level 2 Site Risk Analysis for Nordic Power Plants. in M Beer & E Zio (eds), Proceedings of the 29th European Safety and Reliability Conference., 0276, Research publishing services, Singapore, pp. 3790-3797, 29th European Safety and Reliability Conference, Hannover, Germany, 22/09/19.

    Experience from Level 2 Site Risk Analysis for Nordic Power Plants. / Holmberg, Jan-Erik; Authén, Stefan; Bäckström, Ola; Xuhong, He; Massaiu, Salvatore; Tyrväinen, Tero.

    Proceedings of the 29th European Safety and Reliability Conference. ed. / Michael Beer; Enrico Zio. Singapore : Research publishing services, 2019. p. 3790-3797 0276.

    Research output: Chapter in Book/Report/Conference proceedingConference article in proceedingsScientificpeer-review

    TY - GEN

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    AU - Holmberg, Jan-Erik

    AU - Authén, Stefan

    AU - Bäckström, Ola

    AU - Xuhong, He

    AU - Massaiu, Salvatore

    AU - Tyrväinen, Tero

    PY - 2019/9

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    N2 - The objective with the SITRON (SITe Risk On Nuclear installations) project has been to search for practical approaches for Nordic utilities to assess the site level risk. This paper presents the findings from the performance of level 2 PSA, i.e., the assessment of radioactive release risk from multiple units. Qualitatively, a multi-unit level 1 and 2 PSA are similar in terms of identifying dependencies. Level 2 PSA may bring some additional dependencies that are not relevant for level 1 PSA. Quantitatively, the difference in the used risk metrics can have some practical implications. In level 1 PSA, risk metrics are the frequencies of combinations of core damages (one, two, ..., all units). In level 2 PSA, risk metric is the frequency of a certain release category (small, large, early, late), which is determined by the aggregated release rather than number of releases. The need to quantify various accident sequences is thus much dependent on the applied safety goal for level 2 PSA. Further, pilot studies indicate that inter-unit dependencies in level 2 safety functions have less influence on results than inter-unit dependencies in level 1 safety functions.

    AB - The objective with the SITRON (SITe Risk On Nuclear installations) project has been to search for practical approaches for Nordic utilities to assess the site level risk. This paper presents the findings from the performance of level 2 PSA, i.e., the assessment of radioactive release risk from multiple units. Qualitatively, a multi-unit level 1 and 2 PSA are similar in terms of identifying dependencies. Level 2 PSA may bring some additional dependencies that are not relevant for level 1 PSA. Quantitatively, the difference in the used risk metrics can have some practical implications. In level 1 PSA, risk metrics are the frequencies of combinations of core damages (one, two, ..., all units). In level 2 PSA, risk metric is the frequency of a certain release category (small, large, early, late), which is determined by the aggregated release rather than number of releases. The need to quantify various accident sequences is thus much dependent on the applied safety goal for level 2 PSA. Further, pilot studies indicate that inter-unit dependencies in level 2 safety functions have less influence on results than inter-unit dependencies in level 1 safety functions.

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    KW - severe accident

    KW - risk metrics

    KW - human reliability analysis

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    Holmberg J-E, Authén S, Bäckström O, Xuhong H, Massaiu S, Tyrväinen T. Experience from Level 2 Site Risk Analysis for Nordic Power Plants. In Beer M, Zio E, editors, Proceedings of the 29th European Safety and Reliability Conference. Singapore: Research publishing services. 2019. p. 3790-3797. 0276