A new method to study hydriding processes from the inner surfaces of fuel claddings

In this paper, a new method that allows the study of the hydriding process of fuel claddings from the inner surfaces is presented. The hydriding is performed by heating the cladding in an ultra-high vacuum chamber while hydrogen flows inside the tube. The external H2 partial pressure, the tube electrical resistance and the power dissipated by the reaction are measured throughout the process. These measurements at different hydriding stages are complemented with an optical microscopy analysis of the claddings give insight into the main physical processes. As a consequence a description of the hydriding first stages is provided. The method allows the measurement of the incubation and failure times and the total energy dissipated by the hydriding reaction.