Nuclear waste management requires the packaging of several kinds of metal wastes for long-term storage. These wastes, which can be very reactive metals, are prone to corrosion and commonly immobilised into containers with hydraulic binders as embedding matrices. Innovative binders (low carbon cements, alkali activated materials) are thus developed to increase the packaging performances. The main objective of the European project STREAM (in the frame of the Eurad-2 program) is to evaluate the interactions between these metal wastes and the selected cement matrices. The PhD thesis purpose is to investigate the reactive metal corrosion in the selected binder with electrochemical techniques. A generic experimental protocol will be developed in order to determine the impact of the corrosion products growth at the metal/binder interface on the global mechanical behaviour of the binder-waste composite and possible micro-cracks occurrence. A post-mortem characterisation will be performed on the metal/binder microstructure with mechanical properties measurements of the materials at the interface, especially the corrosion products. Afterwards, these results will feed a simplified Hydro-Chemo-Mechanical (HCM) model aiming the simulation of corrosion consequences on the composite material behaviour. Subsequently, this model will be used for long-term simulation at the waste package scale.
This research project is aimed at a PhD student wishing to improve his/her skills in materials science both in the experimental field and in the modelling/simulation of coupled physicochemical phenomena.