Probability and Sensitivity Nonlinear Analysis of the Hermetic Cover of Main Shut-off Valve under Extreme Pressure and Temperature

This paper describes the probabilistic nonlinear analysis of the containment hermetic cover of main shut-off valve (MSV) under an extreme internal overpressure and temperature. The scenario of the hard accident in NPP and the methodology of the calculation of the fragility curve of the failure overpressure using the probabilistic safety assessment PSA 2 level are presented. The elasto-plastic behavior of steel material dependent on temperature was considered in software ANSYS. The method of central composite design sampling (CCD) of the response surface methodology (RSM) was used to probability and sensitivity analysis of the hermetic cover reliability.