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

34 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
Event3rd European Review Meeting on Severe Accident Research, ERMSAR 2008 - Nesseber, Bulgaria
Duration: 1 Sep 2008 → …

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.
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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 -