Seismic Fragility Analysis on Nuclear Containment Structure considering the Material Degradation

Abstract

This study focuses on conducting fragility analysis and estimating the change in fragility curve and the structural capacity due to the alkali-silica reaction (ASR) by using nonlinear seismic analysis. The shell element and nonlinear concrete constitutive model of Opensees have been adopted to conduct the nonlinear seismic analysis. As a result, the HCLPF of the containment structure is estimated as 1.407 g, and it is comparatively higher than the value reported by previous researches which use a lumped mass model. In addition, the median capacity of the containment structure is about 2.704 g when it is under the effects of ASR corresponding to the median longitudinal expansion of 0.013 %. Consequently, the median capacity of the containment structure is decreased about 17.5 % with the aforementioned level of alkali-silica reaction.