Analysis Recommendations for Steel-Composite (SC) Walls of Safety-Related Nuclear Facilities

Steel-plate composite (SC) walls are of significant interest for designing containment internal structures for third generation nuclear power plants. As part of containment internal structures, these walls may be exposed to seismic loading and combined thermal and mechanical loading in the event of a postulated accident scenario. Experimental and analytical evaluations indicate that SC walls subjected to accident thermal loading develop nonlinear temperature gradients through the wall thickness and undergo concrete cracking. This concrete cracking significantly reduces the stiffness of the SC walls, and thus the thermally induced forces and moments. The paper includes recommendations for: (i) estimating the structural stiffness of SC walls subjected to accident thermal loading, (ii) estimating the maximum moments induced due to thermal gradients, and (iii) developing linear elastic finite element (LEFE) models of SC walls for conducting dynamic seismic analysis.