Volume 7, Issue 6 (June 2010)
Performance of Zirconium Alloys in Light Water Reactors with a Review of Nodular Corrosion
This paper provides historical context and future direction on selected contributions to understanding zirconium-alloy deformation and corrosion in light water reactors. More detailed discussion of the relative importance of electrochemical potential and hydrogen pickup on nodular corrosion is provided. Since nodular corrosion was observed about 50 years ago, several explanations have been proposed. None have explained all the observations, especially the sharp transition between nodular-free and nodular-covered regions of some fuel rods, with the transition being reversed between high- and low-power regions. However, the effect of electrochemical potential dominates any effects of hydrogen, other than the effect of hydrogen on electrochemical potential.