The paper presents different aspects of reinforcement corrosion by analyzing 17 year-old beams kept in a chloride environment under their service load: the corrosion process in relation to cracks, the characterization of initiation and propagation phases and the mechanical behavior in relation to corrosion intensity. The first one concerns the long term behavior of cracked reinforced concrete members exposed in chloride environment. Despite the fact that crack opening is largely superior to the threshold value that affects the ability of chloride ions to diffuse along a crack, results show no correlation with the initial presence of cracks and the intensity of long-term corrosion along the reinforcement. The second one concerns the comparison between the duration of initiation and propagation phase in relation to the covercrete. The third concerns a model of the mechanical behaviour of corroded reinforced concrete members subjected to bending. It is possible to take into account the effect of reinforcement corrosion on the bond between the steel and concrete by increasing the transfer length as a function of the intensity of corrosion. It is possible to forecast a residual mechanical property to help owners to justify that nuclear power plants will kept their serviceability at a given time.