Applying state‐of‐the‐art microscopy techniques to understand the degradation of copper for nuclear waste canisters

The metallurgy, mechanical properties, and corrosion of Cu, proposed as the barrier for Canadian used fuel containers (UFCs) use in a deep geological repository (DGR), have been studied decades. Bulk properties reported, knowledge applied to strengthen performance Cu produced by electrodeposition cold spray. Despite this success, many degradation mechanisms are unclear from bulk testing, which cannot capture nanoscale phenomena driving degradation. This study provides examples using state-of-the-art microscopy understand degradation, specifically UFCs. Subtle changes electrodeposited microstructure due oxygen segregation observed atom probe tomography (APT). In aggressive sulfide-containing environments, cold-sprayed occurs along particle–particle interfaces, likely inherent manufacturing process. Microscale tensile testing at interfaces confirms brittle cracking Cu. Although experiments not consistent with DGR conditions, results do warrant further on particular.