b'Demonstration of irradiation and non-destructive post-irradiation examinations using modern non-destructive techniques provides a baseline set of data on known materials and opens the door to performing extreme nuclear heated tests on advanced materials including accident tolerant fuel materials.Project Description: and high burnup standard fuels. In A series of experiments wasparallel, several new nondestructive conducted in the TREAT Facility aspost irradiation experimental systems part of commissioning for nuclearand processes have been developed fuel safety research to be continuedand were successfully demonstrated over the next several decades. TREATusing these samples. Five capsules was first constructed in the latewere irradiated with energy injec-1950s to support research on nucleartions and peak cladding temperatures fuel specimens under extremeof between ~212 and ~1312 J/gUO 2nuclear-heated conditions. Followingand ~561~2113C, respectively. a decades-long hiatus, reactor opera- These irradiations resulted in various tions were resumed at TREAT in 2017degrees of fuel damage that were to support the reemerging field ofcharacterized using advanced non-fuel-safety research. The first fueleddestructive examinations.The PIEs tests were performed on fresh light- highlighted that, in the most-ener-water reactor (LWR) type sub lengthgetic transient, zirconium breakout, specimens (4.9% enriched UO 2inalso referred to as candling, was zirconium-alloy cladding) in inertobserved as gross cladding melting gas capsules with the primary objec- and relocation.PIEs also confirmed tive to demonstrate new irradiationresults inferred from in situ instru-capabilities, including calculation ofmentation during irradiation and are energy-coupling factor (ECF), and toconsistent with previous results from provide a baseline reference for inter- other studies. pretation of future experiments on accident tolerant fuel (ATF) designs 2020|AFC ACCOMPLISHMENTS 113'