Corrosion studies of material of construction used in ozonisation process of alkaline radioactive liquid waste

DBP-bearing aqueous intermediate level radioactive waste is generated during carbonate washing of PUREX solvent for reuse. DBP forms very complex, sticky, difficult precipitate with uranyl ion under acidic conditions, during the carbonate destruction step of the treatment process. Hence studies were carried out to introduce a pretreatment step in the process for the degradation of DBP using ozone at room temperature so as to make the waste amenable for conventional treatment. These studies were further complemented by finding the corrosion aspects of the possible materials of construction. The materials of construction used for testing were coupons of stainless steel joints, aluminum, carbon steel, Teflon, neoprene and rubber etc. Coupons were tested in simulated alkaline waste solution, at interphase and in ozone atmosphere up to 100 hours. Weight loss based corrosion rates, roughness and physical, microscopic observations of the material coupons were carried out. The paper describes the collective results of the corrosion of different materials of constructions. (author)