SIMULATION OF WATER RADIOLYSIS BY SONOCHEMISTRY: EFFECTS ON THE ELECTROCHEMICAL BEHAVIOR OF A STAINLESS STEEL

In this study, water radiolysis occurring in nuclear power plants was simulated by sonochemistry. Generated hydroxyl radicals can recombine in others species such as H2O2 and H-2. It is shown that solution conductivity is an important parameter on the evolution of open circuit potential due to the thickness variation of the diffusion layer which may contain sonolysed species (OH center dot, H-2, H2O2) in different concentrations. Current densities increase under ultrasonic irradiation due to an increase of mass transport and charge transfer and to the presence of sonolysed species. The oxide film formed under ultrasonic for 1 h at a passive potential of +0.2 V-SCE shows early stage of passivation and higher disordered state which imply a great decrease of the corrosion resistance behavior of the sample. The polarisation resistance R-p, of the stainless steel is divided by a value of 4.5 under ultrasonic irradiation.