| Abstract Scope |
Even after drying, residual water can remain inside dry casks. This study aims to investigate the long-term uniform corrosion of internal structures caused by radiolysis products generated by radiation through corrosion modeling. COMSOL Multiphysics software was applied to simulate corrosion in SS17-4 and AA6061, both commonly used in cask internals. Corrosion modeling was supported by electrochemical tests under varying pH and H₂O₂ concentrations, as well as thermal analysis. The pH range of 4–6 reflects Korean spent fuel pool conditions, while H₂O₂ (10⁻⁶–10⁻⁴ M) levels were estimated through diffusion–reaction modeling. The thermal model incorporated conduction, convection, and radiation. Results show that SS17-4 and AA6061 maintain good resistance after 50 years, with predicted corrosion depths of 353 µm and 388 µm, respectively, under their most vulnerable conditions. The dual role of H₂O₂ either promoting passivation or inducing depassivation was confirmed to affect the alloys differently.
Acknowledgements: This research was supported by the Korea Radioactive Waste Agency and Korea Institute of Energy Technology Evaluation and Planning (KETEP) and the Ministry of Trade, Industry & Energy (MOTIE) of the Republic of Korea (No. 20224000000120). |