Effect of Pickling and Anodizingon Corrosion Behavior of VVER Fuel Clads

Recently, it has been declared that fuel rods do not need to be anodized for the usage in VVER reactors. In this regard, some studies were planned to investigate the effects of pickling and anodizing treatments on corrosion behaviour of the fuel clads produced by Sooreh company. For this purpose, different surface treated samples of as-received, grinded, pickled, grinded and anodized, and pickled and anodized were prepared. The reference fuel clads in some equal conditions were also employed for comparisons. The results revealed that the corrosion behaviour is completely affected by the surface treatment, and microstructure properties have shown less impact. The oxidation type in the pickled, and pickled and anodized samples are absolutely different from the grinded samples. The anodizing treatment after pickling nearly increases the corrosion resistance by factor of two in comparison to the just pickled ones. The presence of grey oxide layer on the grinded samples are attributed to Monoclinic zirconia which has less corrosion resistance to Tetragonal zirconia.