The ROSSINI project: Development and Characterization of Compact Radiation Detectors for Robotic Inspection of Maritime Containers

The inspection of maritime cargo containers for illicit radioactive and nuclear materials is a critical task in nuclear security. Conventional port-monitoring systems, such as radiation portal monitors, provide efficient first-level screening but are limited by fixed installation points, short acquisition times, reduced spectroscopic capability, and the need to inspect containers through predefined transit lanes. This thesis investigates a complementary inspection strategy based on compact radiation detectors integrated with robotic platforms and supported by artificial-intelligence-based data analysis. The work was developed within the RAISE-ROSSINI framework, whose objective is to enable remotely operated radiological inspections of containers potentially transporting Special Nuclear Material. A multi-step inspection workflow is proposed, consisting of drone-based anomaly detection, external anomaly verification with ground robotic platforms, and detailed anomaly assessment only when the previous stages confirm the presence of a suspicious radiological signal. This strategy is intended to reduce inspection time, increase the number of containers that can be screened, and minimize direct human exposure. To support this multi-step inspection procedure, this thesis focuses on the development and testing of the detector, together with an analysis framework for assessing the severity of the detected anomaly. The goal is to provide an informed preliminary identification of the source and deliver the information needed by port authorities to manage the event appropriately.