Electrochemical systems that could be employed with reversible functions have been developed: electric production in a solid oxide fuel cell (SOFC) mode and hydrogen production in a solid oxide electrolysis cell (SOEC). This paper proposes a model solution using the CFD-Ace software package to simulate the behaviour of a tubular SOEC. Modelling is based on solving conservation equations of mass, momentum, energy, species and electric current by using a finite volume approach on 3D grids of arbitrary topology. The electrochemical behaviour of porous electrode is described using Butler-Volmer equations at triple phase boundaries. The 3D layouts of the current densities, electronic and ionic potentials allow to analyze respective ohmic drops. Simulations indicate that the principal damaging risks at the electrolyte/ anode interface originate from high flux densities of oxygen and from the possible re-oxidation of cermet-based cathode