Numerical Prediction of Molten Corium and Study of Basemat Ablation during Molten Corium Concrete Interaction (MCCI)

Abstract

The purpose of this research project is to understand and validate CORUENCH, a numerical model to study the concrete ablation in the reactor cavity during MCCI, molten corium concrete interaction. Additionally, a simulation of MCCI under postulated severe accident of APR1400 nuclear reactor. CORQUENCH Code consists of an enthalpy-porosity approach in the solution framework which captures melting/solidification processes as well as turbulent natural convection. Validation analysis was completed using actual experiments such as CCI-2 & CCI3, part of Wet Cavity OECD/MCCI, and comparing them to CORQUENCH predicted values. It was found that the code predicted acceptable values to the experimental ones and showed a weakness in predicting ablation in both directions (radial/axial). Thus, allowing for a modification in the source code to improve this weakness. In this study, APR1400 geometry and characteristics were used to predict a scenario of MCCI to determine the outcomes of the model and the amount of concrete ablation. Which was considered acceptable after comparing its results with MELCOR values.

Date of Award	Dec 2022
Original language	American English
Supervisor	Yacine Addad (Supervisor)