Neutron Flux Profiling as a Benchmark for the Applicability of Neutron Activation Analysis in Nuclear Safeguards at a Training Reactor

Neutron Activation Analysis (NAA) is a non-destructive and highly sensitive technique with potential applications in nuclear safeguards verification. This study evaluates the suitability of a training reactor for safeguards-focused NAA through experimental neutron flux profiling. Gold and dysprosium activation foils and wires were irradiated at the BME Training Reactor, and gamma-ray spectrometry was used to quantify induced activity. Results showed a peak thermal neutron flux of approximately 2.5×10¹¹ n/cm²/s, an axial flux profile consistent with diffusion theory, and reflector savings of 5.5–7 cm. These findings confirm that the reactor provides a well-moderated thermal neutron field exceeding IAEA thresholds for safeguards-relevant NAA. The results establish benchmark flux data for training reactor environments and demonstrate their capacity to support safeguards verification by enabling detection of sub-milligram quantities of U-235 and Pu-239.