Evaluation of High-Temperature Oxidation Behavior of ATF Claddings During Severe Accidents in Nuclear Power Plants

Abstract

This work aims to evaluate the oxidation behavior and kinetics of ADSS B#51 in high-temperature air up to 1300°C and to investigate the effect of the T-ramping rate on the oxidation kinetics of ADSS B#51. Using Thermo-Gravimetric Analyzer (TGA), the high-temperature oxidation test was performed isothermally in air at 1000ᵒC (16 hours), 1150ᵒC (8 hours), and 1300ᵒC (2 hours) and for T-ramping tests at 1ᵒC/min, 4ᵒC/min, 40ᵒC/min. After which the surface characterization explored the structure of surface oxide and the morphology and compositions of surface oxide using SEM-EDS (scanning electron microscopy – energy dispersed spectroscopy). By utilizing the experimental knowledge, an estimation model for the T-ramping oxidation was developed and used to estimate the oxidation parameters of Tramping conditions. It was concluded the oxidation rates of the alloy during T-ramping were higher than those estimated by iso-thermal test results, and surface oxide characterization using SEM-EDS demonstrated the complicated surface oxide and unclear patterns of their surface oxide and oxide compositions. The findings showed that T-ramping oxidation kinetics parameters are in between the oxidation kinetics parameters of the steady-state region and transient region of isothermal oxidation, but closer to the transient region.

Date of Award	Apr 2023
Original language	American English
Supervisor	Daniel Choi (Supervisor)