b'Evaluating ThermalFirst-of-a-kind analysis tool enables accurate measurement of multiple Properties ofthermophysical properties of specimens with asymmetric geometries.Advanced Materials T hermal conductivity, thermal contact conductance, specific heat, and total hemispherical emissivity are critical for predicting the fuel temperature during normal and off-normal reactor operation. Knowledge of these properties is imperative to licensing existing and novel fuel and cladding materials. Prior to this research, only thermal diffusivity was measured via the laser flash technique at INL, which measures the temperature TOTAL APPROVED AMOUNT:increase on the rear side of a specimen induced by a laser pulse (flash) on the $304,680 over 3 years front side of the specimen. The conventional method uses sample thickness and the time instant at which the measured temperature is at half of its maximum PROJECT NUMBER:value to determine thermal diffusivity.19P43-009This project enhanced this technique and its capabilities by developing a novel data PRINCIPAL INVESTIGATOR:analysis tool and applying it to new, advanced materials. This was accomplished Tsvetoslav Pavlov by further developing a machine learning-based tool, as well as modifying the COLLABORATOR: laser flash setup. The tool consists of a finite element model (FEM), a least-squares Rensselaer Polytechnic Institute fitting algorithm and experimental data treatment algorithms. Model data is fit to experimental data by using specific thermophysical properties as optimization parameters. The new tool is based on the most recent studies in the field and will allow the determination of multiple thermophysical properties (e.g., thermal conductivity, specific heat, thermal diffusivity, thermal contact resistance, total emissivity) from a single laser flash measurement.The project consisted of three main stages: (1) adapting the tool for measurement of asymmetric specimenfuel fragments and curved cladding specimen; (2) modifying the laser flash facilities in a cost-efficient manner to harvest the full potential of the advanced toolmodifying laser flash components such sample holders and crucibles; and (3) applying the new methodology to various materials of interest. Furthermore, the tool is unique as it can be quickly modified for different specimen, such as encapsulation of liquid specimen for molten salt reactors. Representation of the contact conductance FEM, which simulates the contact between tungsten (blue) and zirconium nitride (brown) via a contact conductance boundary condition at thickness z= z int . The red arrows indicate the direction of the 36 laser beam and heat flow.'