Corrosion behavior of pure copper as a material for high-level radioactive waste in simulated groundwater environments

With the increasing utilization of nuclear energy, the safe disposal of nuclear waste has become a major concern. This study investigates the corrosion behavior of two types of pure copper (Cu) with different processing states in simulated Beishan groundwater by electrochemical tests, mass change measurements, and micro morphology observations. The results show that the two types of copper differ in mechanical properties and microstructure due to their different processing histories. Polarization curves indicate similar corrosion resistance for both materials, with corrosion rates of 11.59×10 −3 mm/a for A-Cu and 12.03×10 −3 mm/a for B-Cu. Corrosion morphology analysis reveals that although both materials form a protective layer of corrosion products, B-Cu develops a more stable and protective film, while the film on A-Cu tends to locally detachment due to internal stress. EDS analysis shows that the inner layer of the corrosion products mainly consists of copper oxides, while the outer layer is rich in sulfur and chlorine. Raman spectroscopy further indicates that the corrosion products on both materials are similar, composed mainly of Cu 2 O, Cu 2 Cl(OH) 3 , Cu 4 (SO 4 )(OH) 6, and Cu 2 (CO 3 )(OH) 2 .