Electrochemical noise (EN) monitoring of 304L stainless steel (SS) and sensitized 304 SS in 3 N nitric acid and nuclear near-high level waste (HLW) solution was carried out using a three nominally identical electrode configuration under open circuit conditions. EN signals characteristics of passivation process was obtained for 304L SS in 3 N nitric acid throughout the measurement period, while in near-HLW solution, features of passivation and depassivation were observed. Potentiodynamic polarization of 304L SS in 3 N nitric acid and near-HLW showed spontaneous passivation. Noise resistance was evaluated from EN time record and this parameter was used in the present investigation to qualitatively assess the corrosion behavior during the immersion period. The average noise resistance was found to be lower in near-HLW solution when compared to 3 N nitric acid. The results of the investigation are presented in this article.