Using MELCOR with enhanced predictive capabilities via Thermochimica to model two severe accident cases of a generic BWR with Zry-2 and FeCrAl

Abstract

The primary goal of this work was to enhance MELCOR’s material modelling capabilities via one-way coupling of Thermochimica. MELCOR is a state-of-the-art code used to simulate the severe accident progression of a nuclear power plant. The first objective was developing the capabilities in Thermochimica to handle the Ionic Two-sublattice Liquid Model in order to leverage the Thermodynamics of Advanced Fuels – International Database (TAF-ID). Using empirically derived data from the TAF-ID allowed Thermochimica to reliably predict the stable phases of nuclear materials and their composition. Secondly, two test case scenarios were simulated in MELCOR using a generic boiling water reactor design that included Case I: Zircaloy-2 cladding, and Case II: FeCrAl cladding. The results from these two cases were analyzed using a one-way coupling approach with Thermochimica to demonstrate potential areas for the improvement o fMELCOR’s current material modelling capabilities.