Toward the development of a three-step coupled modeling for the assessment of air leakage ratio through cracked reinforced concrete walls

Every ten years, the containment buildings of nuclear reactors are tested through a 4-bar relative pressure loading with dry air in order to characterize the leakage ratio through the walls. The experimental and numerical studies (MAEVA, VERCORS, etc.) have shown that both leakages through cracks and through porosity play a significant role in global leakage. In particular, the flow of fluids through these cracks is impacted by their opening variations, their tortuosity, their roughness as well as the presence of occlusions, branches or crossings between cracks. The developments toward a three-step chained model based on weak coupling between Finite Element-Discrete Element-Computational Fluid Dynamic are presented. The aim is to predict the leakage ratio of dry air through a thick cracked RC wall. This estimation will allow the prediction of the air-vapour leakage knowing the leakage of air.