Analyse de la fragmentation thermique en tant que processus d'initiation de l'explosion de vapeur

Titre du congrès :ICAPP seventh International Conference on Advances in Nuclear Power Plants Ville du congrès :Nice Date du congrès :13/05/2007

We propose a theoretical study of the film behaviour and its stability during the phenomenon of drop thermal fragmentation. We discuss the role of the various possible influences on the film collapse and instability processes. We firstly discuss the possibility of simple fuel/coolant contacts as a mechanism for the drop instability. Under this assumption, we then describe and test our model on Nelson & Duda explosivity maps, with a particular emphasis on the description of the film evolution. The reasonable agreement obtained allows us to analyse the effect of various parameters as the ambient pressure, subcooling and trigger pulse shape on the film behaviour in Nelson & Duda experiments. The perspectives of this work are then shortly discussed including extrapolation to more prototypic situations and the role of thermal fragmentation itself.