Study of the behaviour of containment buildings of PWR-type reactors, until complete failure in case of LOCA

This paper presents the results of the nonlinear axisymetric analysis of the behaviour of containment buildings (PWR 900 MWe with metallic skin and PWR 1300 MWe without any skin), under LOCA pressure and temperature loadings. The evolutions of pressure and temperature from the accident are the following: increase of pressure 0.3 bar/hour and increase of temperature 20C/hour. This thermomechanical study has been made with the Finite Element Method, and the CEASEMT system code has been used. The objectives of this study have been obtained: - the pressure of the first of concrete - the pressure of trough fracture of concrete - the ruin modes of the containment building However, the spatial discretization of the structure used in this Finite Element analysis induces limitations to the quantitative evaluation of the fracture of concrete, because the informations about fractures are known only on discrete points. From this analysis, we are not able to show up phenomeneon like strain localizations. (orig./HP)