The effect of lateral flooding on the coolability of irregular core debris beds

Eveliina Takasuo (Corresponding Author), Stefan Holmström, Tuomo Kinnunen, Pekka Pankakoski, E. Hosio, Ilona Lindholm

    Research output: Contribution to journalArticleScientificpeer-review

    12 Citations (Scopus)

    Abstract

    The coolability of ex-vessel core debris is an important issue in the severe accident management strategy of, e.g. the Nordic boiling water reactors. In a core melt accident, the molten core material is expected to discharge into the containment and form a porous debris bed on the pedestal floor of a flooded lower drywell. The debris bed generates decay heat which must be removed by boiling in order to stabilize the debris bed and to prevent local dryout and possible re-melting of the material. The STYX test facility which consists of a cylindrical bed of irregular alumina particles has been used to investigate the effect of lateral coolant inflow on the dryout heat flux of the particle bed. The lateral flow was achieved by downcomers attached on the sides of the test rig. The downcomers provide coolant into the lower region of the bed by natural circulation. Both homogenous and stratified bed configurations have been examined. It was observed that the dryout heat flux is increased by 22–25% for the homogenous test bed compared to the case with no lateral flooding. For the stratified configuration with a fine particle layer on top of the bed, no significant increase in the dryout heat flux was observed. The experiments have been analyzed by using the MEWA-2D code. Models which include explicit consideration of gas–liquid friction were used in the calculations in order to realistically capture the lateral flow configuration.
    Original languageEnglish
    Pages (from-to)1196-1205
    Number of pages10
    JournalNuclear Engineering and Design
    Volume241
    Issue number4
    DOIs
    Publication statusPublished - 2011
    MoE publication typeA1 Journal article-refereed
    Event18th International Conference Nuclear Energy for New Europe 2009 - Bled, Slovenia
    Duration: 14 Sep 200917 Sep 2009

    Fingerprint

    debris
    Debris
    heat flux
    beds
    flooding
    Heat flux
    accident
    Coolants
    Accidents
    containment
    aluminum oxide
    Boiling water reactors
    Aluminum Oxide
    coolants
    inflow
    vessel
    friction
    accidents
    melting
    Test facilities

    Cite this

    Takasuo, Eveliina ; Holmström, Stefan ; Kinnunen, Tuomo ; Pankakoski, Pekka ; Hosio, E. ; Lindholm, Ilona. / The effect of lateral flooding on the coolability of irregular core debris beds. In: Nuclear Engineering and Design. 2011 ; Vol. 241, No. 4. pp. 1196-1205.
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    abstract = "The coolability of ex-vessel core debris is an important issue in the severe accident management strategy of, e.g. the Nordic boiling water reactors. In a core melt accident, the molten core material is expected to discharge into the containment and form a porous debris bed on the pedestal floor of a flooded lower drywell. The debris bed generates decay heat which must be removed by boiling in order to stabilize the debris bed and to prevent local dryout and possible re-melting of the material. The STYX test facility which consists of a cylindrical bed of irregular alumina particles has been used to investigate the effect of lateral coolant inflow on the dryout heat flux of the particle bed. The lateral flow was achieved by downcomers attached on the sides of the test rig. The downcomers provide coolant into the lower region of the bed by natural circulation. Both homogenous and stratified bed configurations have been examined. It was observed that the dryout heat flux is increased by 22–25{\%} for the homogenous test bed compared to the case with no lateral flooding. For the stratified configuration with a fine particle layer on top of the bed, no significant increase in the dryout heat flux was observed. The experiments have been analyzed by using the MEWA-2D code. Models which include explicit consideration of gas–liquid friction were used in the calculations in order to realistically capture the lateral flow configuration.",
    author = "Eveliina Takasuo and Stefan Holmstr{\"o}m and Tuomo Kinnunen and Pekka Pankakoski and E. Hosio and Ilona Lindholm",
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    The effect of lateral flooding on the coolability of irregular core debris beds. / Takasuo, Eveliina (Corresponding Author); Holmström, Stefan; Kinnunen, Tuomo; Pankakoski, Pekka; Hosio, E.; Lindholm, Ilona.

    In: Nuclear Engineering and Design, Vol. 241, No. 4, 2011, p. 1196-1205.

    Research output: Contribution to journalArticleScientificpeer-review

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    AU - Takasuo, Eveliina

    AU - Holmström, Stefan

    AU - Kinnunen, Tuomo

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    AU - Hosio, E.

    AU - Lindholm, Ilona

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    AB - The coolability of ex-vessel core debris is an important issue in the severe accident management strategy of, e.g. the Nordic boiling water reactors. In a core melt accident, the molten core material is expected to discharge into the containment and form a porous debris bed on the pedestal floor of a flooded lower drywell. The debris bed generates decay heat which must be removed by boiling in order to stabilize the debris bed and to prevent local dryout and possible re-melting of the material. The STYX test facility which consists of a cylindrical bed of irregular alumina particles has been used to investigate the effect of lateral coolant inflow on the dryout heat flux of the particle bed. The lateral flow was achieved by downcomers attached on the sides of the test rig. The downcomers provide coolant into the lower region of the bed by natural circulation. Both homogenous and stratified bed configurations have been examined. It was observed that the dryout heat flux is increased by 22–25% for the homogenous test bed compared to the case with no lateral flooding. For the stratified configuration with a fine particle layer on top of the bed, no significant increase in the dryout heat flux was observed. The experiments have been analyzed by using the MEWA-2D code. Models which include explicit consideration of gas–liquid friction were used in the calculations in order to realistically capture the lateral flow configuration.

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