Evaluation of corrosion on the fuel performance of stainless steel cladding

Abstract

The use of iron-based alloys as cladding material presents some advantages related to the mechanical and corrosion resistance with the main advantage associated with the reduction of the probability of the violent oxidation reaction that occurs with zirconium-based alloys at high temperatures as it was observed in the Fukushima Daiichi accident. In this sense, iron-based alloys appear as an important alternative in the research effort aiming to develop accident tolerant fuels (ATF). However, the computationally available tools to analyze the fuel rod performance under irradiation do not allow us to assess iron-based alloys as cladding material. This paper addresses the iron-based alloy behavior related to corrosion in a modified fuel performance code in order to evaluate its effect on the global fuel performance. Then, data from the literature concerning to iron-based alloys corrosion were implemented in the specific code subroutines, and the obtained results were compared to those of zirconium-based alloys under the same power history. The results have shown that the effects of corrosion on iron- based alloys are much different from those of zirconium-based alloys. The thickness of the oxide layer formed on the iron-based alloys surface is considerable lower than those presented on the zirconium-based alloys. As a consequence of this, the global fuel performance of iron-based alloys under irradiation is less affected by the corrosion.