b'fission gas release. The performance of this fuel has been extensively studied in out-of-pile and in-pileFramatome has aggressively pushed the implementation test programs. Chromia-doped fuelschedule for the DOE EATF project by inserting the first full topical report for PWR application islength fueled coated EATF LTRs into a commercial reactor currently under Nuclear RegulatoryVogtle in Spring 2019 and followed that with full length Commission (NRC) review.coated LTRs in ANO in Fall 2019 and a full EATF lead test assembly of coated rods at Calvert Cliffs in Spring 2021 on Framatomes EATF pellet develop- its journey to full batch implementation.ment is also focused on improving thermal-mechanical properties, especially thermal conductivity. Variants of Cr-doped UO 2fuel pellets have been developed and out-of-pile testing showed a significant increase in thermal conductivity compared to UO 2 . As part of the proof-of-concept, investigation has been focused on understanding evolution of thermal conductivity and microstructure under irradiation. Framatome fabri-cated and shipped rodlets containing chromium variant pellets for testing in ATF-1 experiments. Framatome is also developing a composite cladding comprising a silicon carbide fiber in a silicon carbide matrix (SiCf/SiCm) forrevolutionary performance improve- for irradiation in the MassachusettsFigure 2. Cr-coated fuel rods after two ments. The objective is to develop aInstitute of Technology Reactorcycles in Vogtle (left and right corner (MITR) and Advanced Test rods were coated with chromium) system which does not suffer from the same rapid oxidation kineticsReactor (ATR). of zirconium-based cladding whileFramatomes innovative SiC-based having attractive operating featurescladding design solves critical feasi-such as reduced neutron absorptionbility issues and NRC concerns such cross-section and higher mechanicalas hydrothermal corrosion, fission strength at accident temperatures.gas retention and end plug sealing.Currently, Framatome fabricated test rodlets made of SiC-based composite 2022|AFC ACCOMPLISHMENTS 111'