b'PIE of Coated Cladding rods from ATF-2Principal Investigator: Fabiola Cappia (INL)Collaborators: Kiran Nimishakavi (Framatome), Russ Fawcett (Global Nuclear Fuel) and Luke Olson (Westinghouse)C oated zirconium alloy fuelare needed to confirm and complete cladding concepts are beingthe former. The goal of the PIE on the pursued by several U.S. fuelcoated rods is to verify the perfor-vendors as part of the U.S. Departmentmance of these ATF concepts with of Energys Accident Tolerant Fuelfocus being on corrosion behavior, (ATF) program. Coated zirconiumirradiation-induced microstructural alloys are near-term evolutionaryevolution and mechanical properties concepts with potential of allowingof the cladding. The data gathered are longer coping times during accidentof fundamental importance to validate scenarios while maintaining ormaterial models, to confirm the improving cladding performanceimproved performance anticipated by during normal operation and opera- out-of-pile testing and to build the PIE tional transients. database that can support qualification Project Description: and licensing of the new concepts. Better performance of the clad- Each of the industry partner is ding and mitigation of detrimentalpursuing a coated cladding ATF candi-phenomena such as oxidation anddate. Westinghouse and Framatome hydrogen pick up can result in bothare focusing on Cr-coating of their increased safety margin and longercommercial pressurized water reactor exposure times without operational(PWR) cladding concepts, specifically penalty. For instance, out-of-pileM5 and Zirlo, while Global Nuclear testing of coated cladding have shownFuel (GNF) is pursuing ARMORTM-that the coating provides enhancedcoated Zircaloy-2 cladding. The protection of the fuel rod against wearrodlets were inserted for irradiation and fretting and improved oxida- in the Advanced Test Reactor (ATR) tion resistance, both during normalpressurized loop starting in 2018. operation and during accidents [13].The first rodlets completed irradia-While tests on non-irradiated materialtion at the end of 2019 and PIE have are fundamental for value assess- been conducted on these first rodlets ment of the ATF candidates, in-pilethroughout the fiscal year.tests under prototypical Light WaterAccomplishments:Reactor (LWR) conditions such thoseThe PIE took place in the Hot Fuel of the ATF-2 loop and subsequentExamination Facility (HFEF) at Idaho post irradiation examination (PIE) 92 2020|AFC ACCOMPLISHMENTS'