Internationally it has been concluded that the best way of storing radioactive waste from nuclear plants is by placing the waste in deep geological repositories. It is considered that an efficient and economically viable way to prevent the waste of coming in contact with the environment is by sealing it in copper canisters. In Sweden the main threat to the integrity of the copper canisters is sulfide-induced corrosion caused by a small concentration of sulfide-containing species present in the surrounding ground water. Furthermore, it has also been discussed in the literature that water can react with the copper surface forming H2 (which can be understood as the cathodic reactions in the electrochemical process). In this project we intend to study corrosive processes on copper from a theoretical point of view. In order to achieve this we have to take into account the conditions of the ambient medium in the nuclear waste repository, especially regarding to pH and corrosion potential. For this reason we plan to use the state-of-the-art methods developed by the group of Professor Jan Rossmeisl for understanding electrochemical processes using DFT calculations. The aim is to understand at an atomic scale the interaction of the species H2S, HS-, H2O, OH-, and H+ as well as the H2 reaction on the most reactive copper surface, the (110) facet. In this way we can obtain insights that are necessary for the design of a safe storage of nuclear waste.
1. King, F., C. Lilja, and M. Vahanen, Progress in the understanding of the long-term corrosion behaviour of copper canisters. Journal of Nuclear Materials, 2013. 438(1-3): p. 228-237.
2. Nielsen, M., et al., Towards first principles modeling of electrochemical electrode-electrolyte interfaces. Surface Science, 2015. 631: p. 2-7.