• sodium cooled reactor
• vapor explosion

The explosion of superheated sodium is a phenomenon of interest in the analysis of automatic shutdown for negative reactivity occurred in the Phénix reactor.
This work aims at improving the understanding of vapor explosion initiated by the presence of a certain quantity of metastable superheated sodium. A particular configuration has been addressed, representative of the Phénix core and aiming at estimating the pressure loads on the fuel assemblies, occurring during an hypothetical event of a vapor explosion.
The case of vapor explosion initiated within the DAC assembly is addressed, since it is suspected to be at the origin of the Phénix AURNs. An analytical model is proposed, since no models are available for this particular phenomenon, basing on theoretic knowledge in physics and fluid-dynamics subjects. The system of equations proposed is then implemented in cast3m code making use of numerical schemes and computational methods.
The results of this analysis will be used as source terms for IFS investigation (fluid-structure interaction).