b'Real-time Non-equilibriumInnovative transmission electron microscope modification Studies for Nuclearleads to faster and cheaper nuclear fuel qualification.Materials PerformanceT his project developed and tested a new device that can replicate the thermal gradients experienced in sodium-cooled fast reactors in a transmission electron microscope. Such capability is not commercially available. This device can provide insights into thermally driven phenomena that govern the microstructural evolution of nuclear materials and enable evaluation of the microstructure and phase evolution in real time. These studies can reduce the time and cost of experiments associated with testing and qualification of new PROJECT NUMBER:nuclear materials and fuel. Indeed, the proposed device can reduce irradiation 21A1055-003 campaign by down-selecting materials based on their thermal behavior before TOTAL APPROVED AMOUNT:irradiation testing is conducted.$125,000 over 1 year In this project, the feasibility of obtaining a prototypical thermal gradient on the PRINCIPAL INVESTIGATOR:order of 10 C/m was confirmed. The temperature was measured via the sublimation Fidelma Di Lemma of silver nanocubes. Moreover, the desired sample configuration for the experiments was optimized. This included engineering a sublayer to minimize sample interaction CO-INVESTIGATORS: with the heating element. Testing of this capability on nuclear fuel, such as uranium-Lingfeng He, INL zirconium and uranium-molybdenum alloys, was performed and provided scientific Joerg Jinschek, The Ohio State University insight into phase and microstructure transition under thermal gradients. Phase Sriram Vijayan, The Ohio State University segregation varied across the thermal gradient and grain nucleation was observed to start in the hot region of the thermal gradient preferably at grain boundary triple junctions. The setup was also applied to study rare earth behavior in metallic fuel. The experiment highlighted the capability of the device to monitor elemental redistribution. As rare earth elements were found to redistribute from the hot region to the cold region.TALENT PIPELINE:Sriram Vijayan, postdoc at The Ohio State UniversityKaustubh K. Bawane, postdoc at INL, converted to staff Left: The modified micro electromechanical system heater and the mounted sample. Right: The thermal gradient across the sample is monitored via sublimation of silver nanocubes. 33'