Chimney Walls Behavior When Submitted to an Internal Explosion

The nuclear fuel reprocessing or fabrication and power plants must be assessed for a set of various normal and accidental situations including explosions due to either operation hazards or malevolent acts. In order to evaluate the consequences of such an aggression in terms of damage to the plants and of radiological release in the environment, IRSN has launched a program including experiments and development of numerical models concerning the behavior concrete walls which are parts of plants. The purpose of this document is to present numerical simulations of chimney wall behavior when submitted to an internal explosion. The simulation uses a three dimensional model with a finite element code. The wave propagation is estimated including the reflection on the wall (the combination between the incident wave and the reflected waves, the attenuation). The detonation simulation is done in considering the walls at rest. The dynamic response of the structure is an estimation relating the time sequence in which the pressure is applied on the surrounding walls. The concrete and iron reinforcements have been taken into account. The stresses, strains and the percentage of cracks in wall are estimated.