The aim of this work was to determine the main characteristics of the passivation and surface oxidation of 08H18N10T, AISI304 and AISI316L stainless steels, which serve as structural materials of VVER and PWR nuclear reactors. With the help of electrochemical experiments these materials were ranked according to their resistance against uniform corrosion. The measurements were done as a function of temperature in the range between room temperature and 80 degrees C. A sample of 08H18N10T steel was irradiated in the Budapest research reactor. With cyclic voltammetry we found that AISI 304 exhibits a very large passivation peak as a classical example for passivation. The peak is much smaller for AISI 316L and it is very small for 08H18N10T. This implies that the native oxide layer on AISI 316L and 08H18N10T is more protective than on AISI 304. The 08H18N10T steel has the best protective passive oxide layer which forms already in air and it is very difficult to remove it even at negative potentials. By comparing impedance spectra of the various stainless steels results lead to the same conclusions we obtained from cyclic voltammetry. Our experimental results of the irradiated steel are in accord with the fact that neutron irradiation increases the number of defect sites within the oxide layer. We found that irradiation has no considerable effect on the active-to-passive transition process. The small variations in the alloy composition do not alter the transition process significantly, as well. (c) 2007 Elsevier Ltd. All rights reserved.