Probabilistic analysis of failure of the steam distribution device

The parameters used in structural integrity analyses are approximate and have distributions associated with their uncertainties. The material parameters, structural geometry and the applied loads (pressure, force, and temperatures) are all uncertain. These random effects should be incorporated into the analysis in order to have a more realistic estimation of the range of the structural response. The probabilistic analysis of failure of the steam distribution headers and their connections to the vertical vent pipes during a loss-of-coolant accident is the main subject of this paper. The codes ProFES and NEPTUNE are used for probabilistic analysis of failure of the steam distribution headers and their connections with the vertical vent pipes. ProFES is a probabilistic analysis system that allows designers to perform probabilistic finite element analysis (FEA) in a 3D environment that is similar to modern deterministic FEA. In this study ProFES is coupled to the deterministic finite element code NEPTUNE. The coupled code approach simplifies the modeling of uncertainties and evaluates the effect of these uncertainties on model and system reliability. Monte Carlo Simulation and Response Surface Methods were used for probabilistic analyses of the steam distribution headers and their connections with the vertical vent pipes. (authors)