Damage Prediction for an AP1000 Nuclear Island Subjected to a Contact Explosion

Abstract

The reinforced concrete (RC) shield building is an important defence layer of AP1000 nuclear islands, as it protects the steel containment vessel of the nuclear power plant. Therefore, the safety and integrity of the RC shield building must be ensured throughout the plant’s operational life under all conditions—especially the application of blast loading. This paper presents the prediction formulae for the volume and shape of damage to the RC shield buildings of AP1000 nuclear islands resulting from contact explosion. The coupled Euler–Lagrange (CEL) algorithm and the Riedel–Hiermaier–Thoma (RHT) concrete damage constitutive model were used to numerically simulate the fluid–structure interaction (FSI) between the explosives, the air and the AP1000 nuclear island. The limitations of empirical spall prediction and Unified Facilities Criteria (UFC) 3-340-02 curves for shell structures are discussed. A detailed analysis reveals the relation between the volume and shape of the damage caused to the AP1000 nuclear island and the mass of explosives and concrete strength. It is also found that the lateral stiffness and tensile stiffness are the main factors that affect the damage volume and damage shape resulting from contact explosion, respectively.