Constriction Percolation Model for Coupled Diffusion-Reaction Corrosion of Zirconium in PWR

Abstract

We develop a new constriction-based percolation paradigm, using cellular automata to predict the transport of oxygen through a stochastically-cracked Zr oxide layer within a real-time coupled diffusion-reaction framework We simulate such branching trees by generating a series of porosity-controlled media. Furthermore, we develop an analytical criterion based on compressive yielding for bridging the transition state in corrosion regime, where the percolation threshold has been achieved. Consequently, our model predicts the arrival rate of oxygen ions at the oxide interface during the so-called post-transition regime, where the bulk diffusion is no longer the rate-limiting factor.