This paper describes the modelling of the hydromechanical evolution of a nuclear waste canister with an initial defect. The waste canister in the Swedish concept consists of a corrosion- resistant copper shell that covers a cast iron insert that provides mechanical strength.

If there is an initial penetrating defect in the copper shell, water will be able to contact the insert. Ingress of water is a prerequisite for corrosion of the iron insert, which in turn gives rise to production of hydrogen gas. Water is also a prerequisite for corrosion of the fuel assembly's metal parts, fuel dissolution and radionuclide transport. Due to the fact that the corrosion processes both consume water and generate hydrogen, strong couplings exist between the chemical and the hydraulic evolution, which must therefore be described in a coupled context. Certain aspects of the mechanical evolution must also be dealt with in parallel with the hydrochemical processes.