Analysis of studies and procedures of the management of aging due to stress corrosion action in a dry storage unit of irradiated fuels with a view to life extension

The use of UAS in Brazil is an alternative to increase the operation of the plants of the Central Nuclear Almirante Álvaro Alberto, with a proposal for decommissioning. Considering that austenitic stainless steels are widely used in UAS due to peculiar characteristics of mechanical and corrosion resistance, the emergence of stress corrosion cracking is a critical point to discuss the UAS's service life. It was found that stress corrosion, its occurrence was found in regions near the sea intensified from the heat coming from the welding process of the canister can opportunize its occurrence. The lack of definition of a final destination and aiming at prolonged operation subject to aggressive conditions can make the extension of the operating license of the UAS unfeasible. With a view to aging management, the study proposes to present a model of procedures in order to evaluate the development of stress corrosion in the canister and to qualify the useful life of the UAS through the application of a flow of inspections and predictive actions for the early identification of a adversity. (author)