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Conference papers
Hybrid lumped/distributed parameter model for treating the vessel lower head ablation by corium during a LWR severe accident
Abstract : Within the context of Severe Accident for Light Water Reactors, the studies of in-vessel
corium behavior and associated risk of vessel failure are matters of prime interest. The corium
heat flux at the pool interface can lead to the ablation of the steel vessel wall. The ablation
kinetics is of prime interest when considering the possible formation of a “thin” metal phase on
the top of the pool and the potential vessel failure at that point due to heat flux concentration,
in particular when evaluating the chances of success of in-vessel retention (IVR) strategy. In
the framework of so-called severe accident codes where fast-running models are used, standard
models based on a 2D meshing of the wall can become impractical in particular when a too
thin metal phase appears. Thus, this paper is focused on a simplified yet accurate modelling
of the wall heating and ablation. It is based on a 1D axial meshing of the wall. For each wall
mesh, radial heat fluxes at the wall internal and external boundaries are calculated following
a lumped parameter modelling approach while the axial heat fluxes are approximated by a
first-order finite difference formula. This model is validated against reference 2D solutions
of the heat equation on pure conduction cases starting from a typical in-vessel configuration
and constructed from nondimensionalization considerations. Finally, this model is applied to
in-vessel corium transient calculations under IVR conditions.
Cited literature [10 references]
https://hal-cea.archives-ouvertes.fr/cea-02338717
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Submitted on : Monday, February 24, 2020 - 3:36:18 PM
Last modification on : Tuesday, April 28, 2020 - 11:28:13 AM
Long-term archiving on: : Monday, May 25, 2020 - 6:45:09 PM
Contributor : Bibliothèque Cadarache Connect in order to contact the contributor
Submitted on : Monday, February 24, 2020 - 3:36:18 PM
Last modification on : Tuesday, April 28, 2020 - 11:28:13 AM
Long-term archiving on: : Monday, May 25, 2020 - 6:45:09 PM
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201800003255.pdf
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