Monte Carlo simulation of non-destructive testing of nuclear fuel based on gamma imaging

Fuel assemblies represent the fundamental structural elements within nuclear reactors, and their operational safety is of paramount importance for ensuring overall reactor reliability. Under complex service conditions, including elevated temperatures, high pressures, and intense neutron radiation environments, fuel pellets housed within rod assemblies are susceptible to deformation, swelling, and potential cladding failure, all of which pose significant safety risks. Accurate characterization of the spatial distribution uniformity of uranium within the fuel matrix is essential for assessing nuclear fuel integrity and enhancing safety margins. This study conducts a computational analysis of uranium distribu tion uniformity in nuclear fuel using gamma imaging methodologies. A dedicated nuclear fuel inspection platform employing gamma imaging techniques was established, with detailed physical models developed and implemented in the MCNP simulation environment. The approach simulates and quantifies uranium distribution through gamma-ray absorption analysis. Scanning gamma imaging simulations were performed, effectively differentiating regions with uniform and non-uniform uranium distributions. These results offer a robust foundation for optimizing detection system configurations and advancing nuclear fuel inspection technologies.