b'ence and coating quality. Currently,lutionary performance improve- Figure 1. Fractography analysis on the lead test rods with BWR coatingments. The objective is to develop athe 15GWd/MtU mechanical testing segments are being irradiated insystem which does not suffer fromspecimens with a) post-failure ring tensile test specimen; b) close-up Monticello reactor and 1st cycle hotthe same rapid oxidation kineticson a fracture surface; c) high-strain cell post-irradiation examinationof zirconium-based cladding whilearea near the fracture surface (PIE) was planned in 2023. having attractive operating featuresdemonstrating cracks in the coating such as reduced neutron absorptiondo not propagate into the substrate Framatomes E-ATF pellet develop- (credit: INL)ment is also focused on improvingcross-section and higher mechanical thermal-mechanical properties,strength at accident temperatures. especially thermal conductivity.Currently, Framatome fabricated test Variants of Cr-doped UO 2fuel pelletsrodlets made of SiC-based composite have been developed and out-of-pilefor irradiation in Massachusetts testing showed a significant increaseInstitute of Technology (MIT) and in thermal conductivity compared toAdvanced Test Reactor (ATR) test UO 2 . As part of the proof-of-concept,reactors. The MIT irradiation has investigation has been focused onstarted late 2022. The ATR irradia-understanding evolution of thermaltion is scheduled to start in 2024.conductivity and microstructureFramatomes innovative SiC-based under irradiation. Framatome fabri- cladding design solves critical feasi-cated and shipped rodlets containingbility issues and NRC concerns such chromium variant pellets for testingas hydrothermal corrosion, fission in ATF-1 experiment, which startedgas retention and end plug sealing.in 2023. Accomplishments:Framatome is also developing aA significant amount of data composite cladding comprisingfrom irradiation campaigns in a silicon carbide fiber in a siliconboth commercial and test reac-carbide matrix (SiCf/SiC) for revo- tors was generated. At INL, the 2023|AFC ACCOMPLISHMENTS 137'