2018 | AFC ACCOMPLISHMENTS 143 Improved high-temperature mechanical properties were obtained through the new processing route (WQ-500 or 600°C) that combines a rapid quenching and a low degree of tempering. thin core components such as fuel cladding and fuel duct. In this effort, therefore, we planned to produce a quenched and tempered martensitic structure with ultrafine laths and precipitates by combining the rapid quenching and nontraditional tempering treatments.We planned to carry out basic characterization for the newly processed materials, including the basic Scanning Electron Microscopy (SEM) andTransmission Electron Microscopy (TEM) for selectedTMTs and uniaxial tensile testing over 22–600°C range for allTMT conditions. Finally, the fracture resistance (J-R) testing in the temperature range of 22–600°C was carried out for selectedTMT conditions to use the data as a primary selection criterion for improved processing. Comparing the test results should enable to propose a few non-traditionalTMTs after which the HT-9 steels demonstrate significantly improved mechanical properties. It is expected the main outcomes of this research will help produce high performance cladding samples for more in-depth characterization. Accomplishments: Design of thermomechanical processes for HT-9 steels and testing and evaluation of the processed samples were performed to determine new processing conditions that can produce optimized microstructures of HT-9 steels with improved mechanical properties. In designing thermomechanical processes it was considered that the proposed treatments, such as the rapid cooling and following tempering treatment, should be feasible for the practical