Corrosion of Copper Lightning Conductor Plates

One method proposed for the long-term storage of nuclear waste material is to place it in copper canisters buried deep underground. To give some information on the long term stability of copper in these circumstances, the corrosion of three copper plates, used as earth electrodes for lightning conductors, was studied in relation to the geochemical properties of the ambient soil. The plates had been buried for more than 50 years in three separate locations. Two of the plates were affected by pitting corrosion with a pitting factor of 5, while the third plate showed no pitting corrosion.The experience from this investigation stresses the importance of careful sampling from a mechanical as well as a chemical point of view.