The effect of different sizes and shapes of 304 Stainless Steels on the oxide removal by electrochemical decontamination

Abstract

Electrochemical decontamination is one of the commonly adopted techniques during decontamination of radioactive wastes. The efficiency of electrochemical decontamination on Type 304 Stainless Steel (304SS) samples with different sizes and shapes was studied in this experiment through weight loss, specific weight loss, and thickness change. Two-layer oxide films on the samples were prepared, with an inner layer simulating oxides formed in boiling water reactor environments, and an outer layer simulating foreign corrosion product deposition. Decontamination processes were carried out by electrolysis in phosphoric acid through a DC power supply. The positive electrode of the DC power supply was connected to the sample as the anode, and the negative electrode of the DC power supply was connected to platinum mesh as the cathode. A constant direct current of 10 amperes was applied to the system at 30°C.

The results showed that when the area of the sample increased, the weight loss also increased. In the meantime, the specific weight loss decreased and the thickness change also decreased. And when the shape of the sample was changed from a flat disk to a sectioned tube, the weight loss, specific weight loss, and thickness change all decreased.