This article concerns an uncertainty and sensitivity investigation of certain parameters in the molten corium concrete interaction (MCCI) test case for VVER1000. It has been used the MEDICIS/ASTECv2.1.1.6 severe accident computer code to describe the basic parameters behaviour and the main phenomena arising during the MCCI in VVER1000 reactor design. The uncertainties in some parameters in the deterministic calculations requires additional investigations. An opportunity for an uncertainty and sensitivity analyses gives SUNSET computational tool which is a part of ASTEC computer code. In this article it have been investigated an influence of eight input parameters on two basic output parameters. It was found out to what extent each one of the eight input parameters affect on the studied output parameters. There also have been collected two groups of input parameters determining the maximal and minimal ranges of the output parameters uncertainties.
Keywords: Molten Corium Concrete Interaction, Severe accident, VVER-1000, ASTEC v2.1.1.6 computer code, SUNSET tool