b'Figure 4. Measured reactor power pulse and the centerline temperature of uncoated Zircaloy-4 cladding sample during the transient imposed by the TREAT facilityand CS Cr-coated Zircaloy-4 tubes were delivered to the TREAT team at INL to assemble the test capsule,The result of prototypical called Static Environment RodletRIA experiments for Cr-Transient Testing Apparatuscoated Zr-alloy designs (SERTTA), for proposed RIA testsin TREAT facility will be (Figure 3). A total of five test vehiclesused for anticipated have been manufactured at INL andlicensing applications the test sample consists of a stackto the U.S. NRC, of ten pellets with eight UO 2pelletsthereby accelerating and a zirconia insulator pellet ondeployment of Cr-coated the top and bottom of the stack. TheATF concepts in U.S. top three pellets have their center- commercial LWR fleetslines drilled out to insert a high temperature type C thermocouple to measure the cladding centerline2023. Two RIA tests with uncoated, temperature during a transientreference Zircaloy-4 samples were experiment. The cladding encasingconducted in June 2023. Figure 4 the pellets has four bare wireshows the reactor power transient intrinsic junction thermocouplesand measured centerline tempera-spot welded to its surface at twoture of a fuel rod sample. The axial elevations. The test capsule isestimated energy deposition was ~ also equipped with two pyrometric- 1000 J/gUO 2and Full Width at Half based water pressure sensors, aMaximum pulse duration was ~ 90 pair of capacitive boiling detectors,ms. PIE will be performed in early and a rodlet pressure detector.2024 including visual inspection, The PVD Cr-coated cladding tube,ring compression test, SEM frac-currently under preparation bytography, and cross-sectional SEM. project collaborator UIUC, will haveThe rest of the four test capsules a test capsule manufactured in latewill be tested by early 2024.2023|AFC ACCOMPLISHMENTS 123'