[en] Various electrochemical methods (corrosion potential monitoring, AC impedance analysis and electrochemical noise monitoring) were used in the investigation of UO₂ samples: natural and doped with two different levels of ²³⁸Pu (0.1 and 10 wt%) simulating the increasing α-intensities seen with time in the repository. The results were compared and were able to show the intense, but also the very local nature of the radiolysis and to demonstrate that corrosion rates were proportional to α-radiolysis and hence the ²³⁸Pu content; the corrosion rates were in accordance with earlier work at ITU. By contrast it was seen that the redox potentials only gave information as to the bulk solution that did not reflect the true conditions at the electrode interface that were driving the corrosion processes of UO₂ dissolution in groundwaters. The study shows how electrochemical techniques can provide vital information on the corrosion mechanism at the UO₂/solution interface