Nuclear Regulatory Commission (NRC)Washington DC 20555Copper (Cu) is a candidate waste container material for high-level radioactive waste geologic disposal systems located in the saturated zone because of its thermodynamic stability in anoxic water. However chemical species in the groundwater could change its stability and electrochemical properties especially corrosion resistance. This study investigated the role of chloride (Cl–) in Cu corrosion in solutions containing sulfate (SO42–) and Cl– with residual oxygen (O2) concentrations of about 0.1–0.2 ppb at 20 °C and 50 °C. SO42– concentration was kept constant at 2000 ppm while Cl– concentration was varied from 0 to 1000 10000 and 100000 ppm. Electrochemical methods including corrosion potential (Ecorr) monitoring potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) were used to study the electrochemical properties of Cu affecting corrosion resistance.All the results obtained from different methods consistently demonstrate that Cl– and temperature play significant roles in enhancing corrosion of Cu when O2 concentration is extremely low. Ecorr decreased with increasing Cl− concentration and was lower at 50 °C than at 20 °C. During both forward and reverse potentiodynamic polarization scans Ecorr consistently decreased and the current density increased with increasing Cl− concentration. Tafel slopes from the forward scan regions decreased and the exchange current density increased with increasing Cl− concentration. The EIS data differed in solutions with different Cl− concentration levels and they became more complex at elevated temperatures. A layered film structure was inferred from the EIS data. Polarization resistance derived by fitting to the EIS data was lowest at the highest Cl− concentration which is consistent with increasing corrosion rates with increasing Cl− concentration. The detailed results will be discussed in thepaper.This abstract is an independent product of the CNWRA and does not necessarily reflect the views or regulatory position of NRC. The NRC staff views expressed herein are preliminary and do not constitute a final judgment or determination of the matters addressed or of the acceptability of any licensing action that may be under consideration at NRC.

The US Navy has used copper alloys for decades for a wide range of applications. This paper seeks to provide insight into some of the applications and the historical corrosion issues faced. The role of the environment will be highlighted. Additionally the key issue of knowledge management with these issues and use of copper alloys will be discussed.

In the Netherlands, a large drinking water distribution system exists which composes of a complex network of underground pipes owned by several water companies. Part of the drinking water distributions pipes consist of cast iron pipes of which some have been installed more than 80 years ago.¹ To prevent leaks, it is desirable to have insight into the condition of these pipes and the risk of leakages or even pipe bursts. During local replacements and maintenance work, corrosion is regularly found in the pipes and previous research⁷ has indicated that Microbiologically Influenced Corrosion (MIC) may be involved in this corrosion that is found in the pipes.