The major concern in the deep geological disposal of spent nuclear fuels include sulfide-induced corrosion and stress corrosion cracking of copper canisters. Sulfur diffusion into copper canisters may induce copper embrittlement by causing Cu2S particle formation along grain boundaries; these sulfide particles can act as crack initiation sites and eventually cause embrittlement. To prevent the formation of Cu2S along grain boundaries and sulfur-induced copper embrittlement, copper alloys are designed in this study. Alloying elements that can act as chemical anchors to suppress sulfur diffusion and the formation of Cu2S along grain boundaries are investigated based on the understanding of the microscopic mechanism of sulfur diffusion and Cu2S precipitation along grain boundaries. Copper alloy ingots are experimentally manufactured to validate the alloying elements. Microstructural analysis using scanning electron microscopy with energy dispersive spectroscopy demonstrates that Cu2S particles are not formed at grain boundaries but randomly distributed within grains in all the vacuum arc-melted Cu alloys (Cu-Si, Cu-Ag, and Cu-Zr). Further studies will be conducted to evaluate the mechanical and corrosion properties of the developed Cu alloys.

1. Introduction
2. Copper Alloy Design
3. Experimental
4. Conclusions
Acknowledgements
REFERENCES

• Minkyu Ahn(Myongji University)
• Jinwoo Park(Myongji University)
• Gyeongsik Yu(Myongji University)
• Jinhyuk Kim(Myongji University)
• Sangeun Kim(Myongji University)
• Dong-Keun Cho(Korea Atomic Energy Research Institute)
• Chansun Shin(Myongji University) Corresponding author