Uncertainty and Sensitivity Analysis of the ASTEC Source Term Results of a MBLOCA Scenario with the Activation of Severe Accident Management Actions in a Generic Konvoi Plant

This paper summarizes the joint contribution of Karlsruhe Institute of Technology (KIT)/Framatome GmbH to the HORIZON 2020 MUSA (Management and Uncertainties of Severe Accidents) project, along with additional simulations conducted outside the project focusing on the uncertainty and sensitivity analysis of the Accident Source Term Evaluation Code (ASTEC) results for a medium-break loss-of-coolant accident scenario. This scenario included the activation of severe accident management actions in a generic KONVOI nuclear power plant. The calculation platform used for these analyses is based on the ASTEC code, developed by Autorité de sûreté nucléaire et de radioprotection (ANSR, formerly IRSN) for severe accident simulations, and the KATUSA (KArlsruhe Tool for Uncertainty and Sensitivity Analysis) tool, developed by KIT as part of the KIT/Framatome WAME project. The release of Xe, I, Cs, and Ba to both the containment and the environment was considered as a key figure of merit in the study. The results for the simple statistics, as well as the Spearman correlations between the figure of merit and the selected uncertain input parameters, are presented and discussed. Additionally, an investigation into the failed simulations is provided, along with the option of using a relative timescale.