Uncertainty and Sensitivity Analysis of Severe Accidents Simulations at VVER in the Framework of the IAEA CRP I31033

The International Atomic Energy Agency (IAEA) launched in 2019 the Cooperative Research Project (CRP) I31033 entitled "Advancing the State-of-Practice in Uncertainty and Sensitivity Methodologies for Severe Accident Analysis in Water-Cooled Reactors". The main goal is to advance the understanding and characterization of sources of uncertainty and investigate their effects on the key figure-of-merits (FOMs) of the severe accident codes predictions in water cooled reactors (WCRs). Having this in mind, within the five-year duration of the CRP, 22 organizations representing 18 Member States have been developing and evaluating calculation platforms based on the currently available severe accident codes and relevant uncertainty tools for uncertainty and sensitivity (U&S) analyses of severe accident scenarios in different WCRs, i.e. PWR, BWR, CANDU, VVER, and SMR. In the CRP framework, the U&S analysis of the QUENCH-06 experiment has also been performed to give relevant insights.