Iodine stress corrosion cracking and possible mitigation strategy for CANDU fuel

Iodine induced stress corrosion cracking, I-SCC, is a recognized factor in the operation of nuclear reactors requiring the implementation of mitigation measures. I-SCC is believed to depend on certain factors such as iodine concentration, oxide layer type and thickness on the fuel sheath, irradiation history, metallurgical parameters related to the sheath like texture and microstructure, and the mechanical properties of zirconium alloys. This work develops a fully mechanistic kinetic model accounting for the iodine chemistry and thermodynamics in the fuel-to-sheath gap. The governing transport equations are solved with a finite-element technique using the COMSOL Multiphysics® commercial software platform. This study also proposes potential remedies for I-SCC. (author)