Analysis of 1:4 scale prestressed concrete containment vessel (PCCV) model subject to pressure and thermal loading

This paper describes the nonlinear analyses of a 1:4 scale model of a prestressed concrete containment vessel (PCCV) which incorporates both pressure and temperature effects. The analyses are performed using, the results of the heat transfer analyses provided as time and/or pressure dependent thermal gradients at representative cross-sections in the model. This paper is focused on the behavior of the NUPEC/NRC 1:4-scale prestressed concrete containment vessel under pressure and temperature loading beyond the design basis. In the nonlinear finite element analyses, the 1/4-scale PCCV including the axisymmetric cylindrical vessel, the spherical dome and the concrete base slab are idealized as an axisymmetric global model with axisymmetric solid elements and shell elements. The temperature-dependent degradation properties of concrete and steel are considered. Both geometric and material nonlinearities including thermal effects are also addressed in the analyses. Menetrey-Willam concrete constitutive model with non-associated flow potential is adopted for this study. This study includes the results of the predicted thermal and mechanical behaviors of the PCCV subject to high temperature loading and internal pressure simultaneously. In order to find the effect of accident high temperature on the ultimate capacity of each component, two kinds of analyses are performed; one for pressure only and the other for pressure with temperature. The results are compared with each other for the liner plate, reinforcement, prestressing tendon and concrete. The analysis results show that the temperature directly affects the behavior of the liner plate, but has a little impact on the ultimate pressure capacity of the PCCV. (authors)