Assessment of a NaIL detector performance for radiation monitoring applications

The European decommissioning and dismantling (D D) market of nuclear facilities is characterized by significant long-term growth. The EU-funded CLEANDEM project aims to develop a technological breakthrough for D D operations that will save time, reduce costs, and minimize human intervention while increasing safety. The project will deliver a cyber-physical system using an unmanned ground vehicle platform equipped with innovative radiological sensing probes. In the framework of the CLEANDEM project, the main goal of this work is to study an alternative solution, i.e., the NaIL detector, to upgrade and integrate the neutron/gamma detection capability to the platform for radiological survey applications. The study consists in characterizing a 2“ × 2” NaIL detector in terms of energy resolution, full-energy peak gamma efficiency, thermal neutron/gamma discrimination capability, neutron efficiency, and gamma rejection ratio (at high counting rate). Besides, the time resolution and the decay time components of the neutron and gamma-ray induced signals have been reported. Experiments were combined with Monte Carlo simulations, using GEANT4 v10.7, to complement the characterization. The Monte Carlo simulations are in good agreement with the experimental results. Finally, an online analysis software has been developed to perform a simple radiological survey in laboratory conditions.