This STP contains the 40 peer-reviewed papers – two papers were named Kroll winners – that were presented at the 17th International Symposium on Zirconium in the Nuclear Industry held in Hyderabad, Andhra Pradesh, India in 2013.

A dominant theme in these papers is the role of hydrogen on the performance of zirconium alloy components. Issues discussed in this volume where performance was dominated by hydrogen included the following:

• Failure of BWR fuel rods was attributed to the localization of hydrides following accelerated corrosion and subsequent cracking of the hydride lenses. Despite an extensive investigation, the cause of the accelerated corrosion was not definitively identified.

• The growth of beta-quenched Zircaloy-2 BWR channels was driven late in life by accelerated hydrogen pickup that coincided with the dissolution of second phase particles.

• As reorientation of hydrides plays an important role during dry storage, in-situ measurements were performed to gain new insights into the reorientation of hydrides in Zircaloy-4.

• Delayed hydride cracking (DHC) growth rate of in-service Zr-2.5Nb CANDU pressure tubes was controlled by thermal and irradiation effects on the microstructure (e.g, decomposition and reconstitution of the beta phase controlling hydrogen diffusion to the crack tip).

In addition to papers that highlight the impact of hydrogen, several papers focus on understanding the mechanisms of hydrogen ingress into the metal or understanding the interaction of hydrogen with point defects and dislocation loops in the matrix.