b'2.4 LWR FUEL SAFETY TESTINGResumption of Water-based RIA Testing in the U.S.Principal Investigator: Charles Folsom Team Members/ Collaborator: David Kamerman, Colby Jensen, Nicolas Woolstenhulme, Jason Schulthess, Leigh Ann AstleT he restart of the TransientA series of Reactor Test (TREAT) facility has renewed the capabilitycommissioning tests for for transient testing of nuclearwater-based reactivity-fuels in the United States. Thisinitiated accidents have capability is critical to support thebeen completed in TREAT mission of the Accident Tolerantto demonstrate the Fuels (ATF) campaign and the recentrenewed capability of RIA U.S. nuclear energy industriestesting to support U.S. interest to extend burnup beyondnuclear energy goals.the current limits of 62 GWd/t. Design basis accident testing in TREAT, such as reactivity-initiated accidents (RIA) and Loss of Coolantanalysis of the experiments (Figure 1). Accidents, can be performed inThe purpose of the ATF-RIA-1 test TREAT to support these efforts.campaign was to commission the The development of the StaticSERTTA capsule and instrumenta-Environment Rodlet Transient Testtion for RIA testing in a static waterApparatus (SERTTA) experimentenvironment in TREAT. Demon-capsule provides the capability tostrating and qualifying the capabilities test Light Water Reactor (LWR) fuelof the SERTTA capsule is required rods in a static water environmentfor planned follow-on testing of ATF under RIA conditions. A seriesas well as high burnup LWR fuels. of six commissioning tests wereTherefore, these tests are crucial for completed in the SERTTA capsule inmeeting industries needs to support TREAT to demonstrate the renewedlicensing these fuels.capability of RIA testing to supportFollowing the irradiations of these U.S. nuclear energy goals. Post- experiments in TREAT, post-transient characterization of thetransient examinations (PTE) of test specimens has been performedthe fuel rodlets were performed as to complete evaluation of thewell as post-test fuel performance specimen/test system performance. modeling predictions. PTE included Project Description: x-ray radiography of the capsules The SERTTA capsule provides a staticprior to disassembly, visualwater environment surrounding theinspections of the rodlets, high fuel rod with a suite of state-of-the- resolution optical profilometry, art and first-of-a-kind instrumentsoptical microscopy, and gamma to collect relevant data for post-test 82 2022|AFC ACCOMPLISHMENTS'