A large quantity of high-level radioactive waste is stored in underground carbon-steel storage tanks at the Hanford site. The waste chemistries are alkaline with pH between 12 and 14. Carbon steel is expected to become passive and undergo passive dissolution under the alkaline conditions. Nonetheless certain corrosive species in the waste chemistries such as chloride and nitrate could cause pitting corrosion and stress corrosion cracking (SCC). The risk of pitting corrosion and SCC increases when open-circuit potentials (OCPs) drift in anodic direction compared to the initial values. Therefore it is important to determine the extent of drift as a function of waste chemistry and metal surface characteristics. Electrochemical experiments were conducted to determine extent of drift in the OCPs. The tests were conducted with the following three surface characteristics: (i) surface with passive film developing in waste simulants (ii) surface will mill-scale (iii) surface with combination of mill-scale and passive film developing in waste simulants. A specialized in-situ scratching mechanism was used to obtain desired in-situ surface characteristics. The electrochemical experiments were conducted for approximately 4 months and OCP evolution was recorded. This paper will present the results of the electrochemical tests and provide quantification of the OCP evolution as a function of surface characteristics.