Coolability of particulate beds in severe accidents: Status and remaining uncertainties

M. Bürger (Corresponding Author), M. Buck, S. Rahman, R. Kulenovic, F. Fichot, W.M. Ma, Jaakko Miettinen, Ilona Lindholm, K. Atkhen

    Research output: Contribution to journalArticleScientificpeer-review

    36 Citations (Scopus)

    Abstract

    Particulate debris beds may form during different stages of a severe accident; e.g. in the degrading hot core, due to thermal stresses during reflooding, in the lower plenum, by melt flow from the core into water in the lower head, and in the cavity by melt flow ou of a failing RPV into a wet cavity. Deep water pools in the cavity are used in Nordic BWRs as an accident management measure aiming at particulate debris formation and coolability. Data from experiments included in the SARNET network (DEBRIS at IKE and STYX at VTT) and earlier ones (e.g. POMECO at KTH) have been used to validate key constitutive laws in 2D code as WABE (IKE) and ICARE/CATHARE (IRSN), especially concerning flow friction and heat transfer. Major questions concern the need of the explicit use of interfacial friction to adequately treat the various flow situations in a unified approach, as well as the adequate characterization of realistic debris composed of irregularly shaped particles of different sizes. Joint work has been supported by transfer of WABE to KTH and VTT. The codes have been applied to reactor conditions for analyzing the potential for coolability in the different phases of a severe accident.Calculations have been performed with WABE(MEWA) implemented in ATHLET-CD and with ICARE/CATHARE for degraded cores and debris beds in the lower plenum, under reflooding and boil-off. Ex-vessel situations have also been analysed. Strong effects of lateral water inflow and cooling by steam in hot areas have been demonstrated. Melt pool formation or coolability of particulate debris is a major issue concerning melt retention in the core and the lower head. Experimental and analysis efforts and respective continued joint actions are discussed, which are needed to reach resolution of the coolability issue.
    Original languageEnglish
    Pages (from-to)61-75
    Number of pages15
    JournalProgress in Nuclear Energy
    Volume52
    Issue number1
    DOIs
    Publication statusPublished - 2010
    MoE publication typeA1 Journal article-refereed

    Fingerprint

    Debris
    accident
    Accidents
    melt
    cavity
    friction
    Friction
    bedform
    Water
    heat transfer
    inflow
    vessel
    deep water
    Thermal stress
    cooling
    Steam
    water
    Uncertainty
    Heat transfer
    Cooling

    Keywords

    • Severe accidents
    • debris coolability
    • reactor safety
    • quenching of hot debris

    Cite this

    Bürger, M., Buck, M., Rahman, S., Kulenovic, R., Fichot, F., Ma, W. M., ... Atkhen, K. (2010). Coolability of particulate beds in severe accidents: Status and remaining uncertainties. Progress in Nuclear Energy, 52(1), 61-75. https://doi.org/10.1016/j.pnucene.2009.09.015
    Bürger, M. ; Buck, M. ; Rahman, S. ; Kulenovic, R. ; Fichot, F. ; Ma, W.M. ; Miettinen, Jaakko ; Lindholm, Ilona ; Atkhen, K. / Coolability of particulate beds in severe accidents : Status and remaining uncertainties. In: Progress in Nuclear Energy. 2010 ; Vol. 52, No. 1. pp. 61-75.
    @article{a3a954aca3e94aee9b1d16050438b881,
    title = "Coolability of particulate beds in severe accidents: Status and remaining uncertainties",
    abstract = "Particulate debris beds may form during different stages of a severe accident; e.g. in the degrading hot core, due to thermal stresses during reflooding, in the lower plenum, by melt flow from the core into water in the lower head, and in the cavity by melt flow ou of a failing RPV into a wet cavity. Deep water pools in the cavity are used in Nordic BWRs as an accident management measure aiming at particulate debris formation and coolability. Data from experiments included in the SARNET network (DEBRIS at IKE and STYX at VTT) and earlier ones (e.g. POMECO at KTH) have been used to validate key constitutive laws in 2D code as WABE (IKE) and ICARE/CATHARE (IRSN), especially concerning flow friction and heat transfer. Major questions concern the need of the explicit use of interfacial friction to adequately treat the various flow situations in a unified approach, as well as the adequate characterization of realistic debris composed of irregularly shaped particles of different sizes. Joint work has been supported by transfer of WABE to KTH and VTT. The codes have been applied to reactor conditions for analyzing the potential for coolability in the different phases of a severe accident.Calculations have been performed with WABE(MEWA) implemented in ATHLET-CD and with ICARE/CATHARE for degraded cores and debris beds in the lower plenum, under reflooding and boil-off. Ex-vessel situations have also been analysed. Strong effects of lateral water inflow and cooling by steam in hot areas have been demonstrated. Melt pool formation or coolability of particulate debris is a major issue concerning melt retention in the core and the lower head. Experimental and analysis efforts and respective continued joint actions are discussed, which are needed to reach resolution of the coolability issue.",
    keywords = "Severe accidents, debris coolability, reactor safety, quenching of hot debris",
    author = "M. B{\"u}rger and M. Buck and S. Rahman and R. Kulenovic and F. Fichot and W.M. Ma and Jaakko Miettinen and Ilona Lindholm and K. Atkhen",
    note = "Project code: 222",
    year = "2010",
    doi = "10.1016/j.pnucene.2009.09.015",
    language = "English",
    volume = "52",
    pages = "61--75",
    journal = "Progress in Nuclear Energy",
    issn = "0149-1970",
    publisher = "Elsevier",
    number = "1",

    }

    Bürger, M, Buck, M, Rahman, S, Kulenovic, R, Fichot, F, Ma, WM, Miettinen, J, Lindholm, I & Atkhen, K 2010, 'Coolability of particulate beds in severe accidents: Status and remaining uncertainties', Progress in Nuclear Energy, vol. 52, no. 1, pp. 61-75. https://doi.org/10.1016/j.pnucene.2009.09.015

    Coolability of particulate beds in severe accidents : Status and remaining uncertainties. / Bürger, M. (Corresponding Author); Buck, M.; Rahman, S.; Kulenovic, R.; Fichot, F.; Ma, W.M.; Miettinen, Jaakko; Lindholm, Ilona; Atkhen, K.

    In: Progress in Nuclear Energy, Vol. 52, No. 1, 2010, p. 61-75.

    Research output: Contribution to journalArticleScientificpeer-review

    TY - JOUR

    T1 - Coolability of particulate beds in severe accidents

    T2 - Status and remaining uncertainties

    AU - Bürger, M.

    AU - Buck, M.

    AU - Rahman, S.

    AU - Kulenovic, R.

    AU - Fichot, F.

    AU - Ma, W.M.

    AU - Miettinen, Jaakko

    AU - Lindholm, Ilona

    AU - Atkhen, K.

    N1 - Project code: 222

    PY - 2010

    Y1 - 2010

    N2 - Particulate debris beds may form during different stages of a severe accident; e.g. in the degrading hot core, due to thermal stresses during reflooding, in the lower plenum, by melt flow from the core into water in the lower head, and in the cavity by melt flow ou of a failing RPV into a wet cavity. Deep water pools in the cavity are used in Nordic BWRs as an accident management measure aiming at particulate debris formation and coolability. Data from experiments included in the SARNET network (DEBRIS at IKE and STYX at VTT) and earlier ones (e.g. POMECO at KTH) have been used to validate key constitutive laws in 2D code as WABE (IKE) and ICARE/CATHARE (IRSN), especially concerning flow friction and heat transfer. Major questions concern the need of the explicit use of interfacial friction to adequately treat the various flow situations in a unified approach, as well as the adequate characterization of realistic debris composed of irregularly shaped particles of different sizes. Joint work has been supported by transfer of WABE to KTH and VTT. The codes have been applied to reactor conditions for analyzing the potential for coolability in the different phases of a severe accident.Calculations have been performed with WABE(MEWA) implemented in ATHLET-CD and with ICARE/CATHARE for degraded cores and debris beds in the lower plenum, under reflooding and boil-off. Ex-vessel situations have also been analysed. Strong effects of lateral water inflow and cooling by steam in hot areas have been demonstrated. Melt pool formation or coolability of particulate debris is a major issue concerning melt retention in the core and the lower head. Experimental and analysis efforts and respective continued joint actions are discussed, which are needed to reach resolution of the coolability issue.

    AB - Particulate debris beds may form during different stages of a severe accident; e.g. in the degrading hot core, due to thermal stresses during reflooding, in the lower plenum, by melt flow from the core into water in the lower head, and in the cavity by melt flow ou of a failing RPV into a wet cavity. Deep water pools in the cavity are used in Nordic BWRs as an accident management measure aiming at particulate debris formation and coolability. Data from experiments included in the SARNET network (DEBRIS at IKE and STYX at VTT) and earlier ones (e.g. POMECO at KTH) have been used to validate key constitutive laws in 2D code as WABE (IKE) and ICARE/CATHARE (IRSN), especially concerning flow friction and heat transfer. Major questions concern the need of the explicit use of interfacial friction to adequately treat the various flow situations in a unified approach, as well as the adequate characterization of realistic debris composed of irregularly shaped particles of different sizes. Joint work has been supported by transfer of WABE to KTH and VTT. The codes have been applied to reactor conditions for analyzing the potential for coolability in the different phases of a severe accident.Calculations have been performed with WABE(MEWA) implemented in ATHLET-CD and with ICARE/CATHARE for degraded cores and debris beds in the lower plenum, under reflooding and boil-off. Ex-vessel situations have also been analysed. Strong effects of lateral water inflow and cooling by steam in hot areas have been demonstrated. Melt pool formation or coolability of particulate debris is a major issue concerning melt retention in the core and the lower head. Experimental and analysis efforts and respective continued joint actions are discussed, which are needed to reach resolution of the coolability issue.

    KW - Severe accidents

    KW - debris coolability

    KW - reactor safety

    KW - quenching of hot debris

    U2 - 10.1016/j.pnucene.2009.09.015

    DO - 10.1016/j.pnucene.2009.09.015

    M3 - Article

    VL - 52

    SP - 61

    EP - 75

    JO - Progress in Nuclear Energy

    JF - Progress in Nuclear Energy

    SN - 0149-1970

    IS - 1

    ER -