Intergranular corrosion simulation of stainless steel considering nitric acid solution condition

Igarashi, Takahiro  ; Irisawa, Eriko ; Kato, Chiaki   ; Ueno, Fumiyoshi  ; Abe, Hitoshi 

Nuclear fuel reprocessing plants contain high-temperature condensed nitric acid solution for dissolution of spent nuclear fuel, and austenitic stainless steels are used as a main material for spent nuclear reprocessing systems. In such a highly oxidizing environment, stainless steel shows the morphology of an intergranular corrosion surface. It is known that grain dropping occurs with intergranular corrosion progress, accelerating the corrosion rate. To keep maintain the safety of the system, it is important to understand the intergranular corrosion behaviour. For understanding the mechanism, we constructed three-dimensional intergranular corrosion computational model of stainless steel considering nitric acid solution condition. Using the model, we showed that increase of face area and grain dropping affect acceleration behavior of total corrosion rate.