Statistical methods for the analysis of safety margins by BE + U codes

Statistical methods for the analysis of safety margins through BE+U codes: This paper presents tools for statistical analysis (PLS, PCS,Variance Decomposition) to understand the relationships between input variables (defined by parameters of the model thermal-hydraulics distribution functions) and output variable, e. g. the PCT variable. The objective is to identify the most important input variables in order to the effect on the output variables. In addition, it is possible to quantify the contribution of the uncertainty of each input variable in the uncertainly of results. the case of application develops a Large Break LOCA in PWR. (Author) 16 refs.