Safety and reliability assessment of heterogeneous concrete components in nuclear structures

It is well accepted that risk analyses of nuclear facilities should be interpreted in the context of probabilistic methods. Nearly all of the current applications only focus on the simulation-based random variable (RV) uncertainty quantification, while the impacts of random fields (RF) are ignored. Since the concrete is a heterogeneous material in different length scales, this paper presents the results of a study that considers the spatial distribution of several concrete parameters in the context of the macro-scale RF theory. A series of probabilistic analyses are designed based on typical structural components of a nuclear facility, i.e., beams, columns, shear walls, and the containment building. Both the strength and vibration characteristics are quantified. The impacts of single/multiple RV(s), correlation length, and construction technique are discussed. The uncertainty and dispersion of the capacity points are determined in each component and compared with each other. Moreover, a model framework is proposed for calibrating large heterogeneous structures, and RF-dependent reliability analysis.