b'Figure 2. Customized split-tube furnace on glide rails (left), and dual-camera images of speckled cladding gauges (right). The cameras are stacked one above the other with a stereo angle less than 20 degrees and focused through the windowadvantages and drawbacks of twoThe second key advantage of DIC-configurations, the dogbone whichbased RHTs is the ability to assess features a dogbone-shaped centralATF coating performance. With insert to support the two gaugesnear-term ATF concepts centered of a ring specimen, and the hemi,on applying chrome coatings on which uses full hemicylindricalexisting zircaloy-based claddings, mandrels to support a single gauge.evaluating the effect and behavior These configurations are shownof these coatings is critical. Full-field in Figure 1. Modeling showed thatdisplacements and strains produced the dogbone exhibits non-uniformfrom DIC measurement can be used stress due to bending, resulting into detect coating cracks as they underpredictions of the strengthdevelop during mechanical loading and significant sensitivity to uncon- of the cladding, helping to establish trollable parameters. Conversely,strain limits of specific coatings and finite element analysis showed theprovide understanding of coating hemi produces uniform stress in thefailure behavior. When paired gauge and overpredicts strengthswith load-displacement data, it can but can be corrected by accountingbecome a powerful tool for evalu-for ring friction. The hemi systemating coated cladding performance. was recently qualified for in-cell useTo realize these benefits, a DIC at INL, joining the dogbone configu- setup was deployed for out of cell ration, but neither had been charac- RHT experiments. Stereo DIC was terized using DIC. By deploying DIC,necessary to measure the curved full-field strain maps can be gener- outer surface of the cladding ated to validate modeling resultswhere coating exists, requiring and to interpret test outcomes. a dual camera system capable of 2023|AFC ACCOMPLISHMENTS 85'