The materials that make up nuclear fuel assemblies, including zirconium alloys, are exposed to the reactor's primary environment, pressurised water at high temperature (around 150 bar, 300°C), neutron bombardment and ionising radiation (gamma, alpha in particular). The combination of these external factors leads to the degradation of materials through corrosion and the formation of irradiation defects. The latter have been shown to have a significant effect on the corrosion and hydrogen absorption kinetics of zirconium alloys. However, the impact of irradiation is material-dependent. The corrosion rate of Zircaloy-4 increases after irradiation of the metal and/or oxide, while the corrosion resistance of the M5 alloy is significantly improved under irradiation. The presence of niobium in the alloy undeniably plays a positive role under irradiation. However, its effect and the associated mechanism remain to be elucidated. Given the short lifetime of the transient radiolytic species and the interplay of the various phenomena mentioned above, in situ measurements are becoming mandatory. The PhD student will work on using and upgrading a unique existing device, co-developed with Framatome, to monitor online the effects of water radiolysis and irradiation on the corrosion and hydrogenation kinetics of various zirconium alloys in contact with a medium representative of the primary medium of pressurised water nuclear reactors. Understanding the mechanisms involved will enable a model to be developed and the first-order parameters to be determined. The thesis work will be promoted through publications and participation in - national and internation - conférences.