Granular media are commonly used for high temperature heat transfer, catalysis, food, and pharmaceutical applications. Understanding the kinetics of dense granular flow via a non-invasive method is essential to flow phenomena studies (e.g., Brazil nut effect, pattern formation, jamming transition, and local rearrangement, etc.) and heat transfer analysis. However, dynamic granular flow studies with a non-invasive method have been limited to radiographic studies due to the rate dependency in granular flow. Tomo-NeRF enables prediction of complex 3D microstructures from a limited number of radiographic images.