Numerical models applicable to catastrophic failures of PWR reactors

Cooperation with the French CEA on development of models underlying software codes written to predict consequences of catastrophic failures in nuclear power plants will be highlighted.

The "Numerical modelling of heat/flow processes occurring in metallic layers of a molten PWR core after a catastrophic failure of the reactor" first lecture will cover behaviour of a metallic layer formed on surface of the pool of destroyed PWR core materials. Basic issues of modelling such situations, including possible configurations of the created pool and applicability of various models will be presented.

The "Numerical heat/structural modelling of a PWR core supporting slab at conditions of a catastrophic failure of the reactor" second lecture will be focussed on the PWR core supporting slab. During a catastrophic failure of the reactor leading to melt down of its core, strength of the supporting slab decreases as its temperature rises, with a possible change of the slab geometry in consequence. The developed model purpose is to accurately represent such phenomena. Stress tests helped to identify the most significant parameters from the point of view of bursting the reactor safety containment.