For many reinforced concrete structures corrosion of the reinforcement is an important problem since it can result in expensive maintenance and repair actions. Further, a significant reduction of the load-bearing capacity can occur. One mode of corrosion initiation occurs when the chloride content around the reinforcement exceeds a critical threshold value. In the present paper FERM (the Finite Element Reliability Method) is employed for obtaining the probability of exceeding a critical chloride concentration level at the reinforcement bars using MCS (Monte Carlo Simulation). The chloride ingress is modeled by a 2-dimensional diffusion process by FEM (Finite Element Method) and the diffusion coefficient, surface chloride concentration and reinforcement cover depth are modeled by multidimensional stochastic fields, which are discretized using the EOLE (Expansion Optimum Linear Estimation) approach. As an example a bridge pier in a marine environment is considered and the results are given in terms of the distribution of the time for initialization of corrosion.