Accident Tolerance Cladding Thermal Hydraulic Simulation and Oxidation Kinetic Sensitivity Analysis

Abstract

Since the Fukushima accident, an increasing number of studies have considered Accident Tolerant Fuels and cladding properties that can improve the safety performance during an accident in a nuclear reactor. In a research project funded by the US Department of Energy, a group at the University of Wisconsin-Madison focused on modeling the fuel performance for beyond design basis accident conditions. The MELCOR 1.8.6-YR program was used to model the SURRY power station for Zircaloy compared to FeCrAl alloy cladding. The model used an oxidation model for FeCrAl developed by Oak Ridge National Lab (ORNL). The ORNL oxidation model was also used to analyze the fuels’ performance, and these results were compared with the results obtained with the Idaho National Lab (INL) oxidation model for FeCrAl. Results showed that the ORNL model predicted a larger amount of hydrogen generated than the INL model. More experimental data may be needed to better understand the FeCrAl oxidation kinetic mechanisms and perfect oxidation models for this alloy.