A SENSORISED LORA-BASED NETWORK FOR THE MONITORING AND IDENTIFICATION OF RADIOACTIVE WASTE DRUMS

A monitoring and surveillance system is a mandatory element to ensure that a radioactive waste disposal facility provides and meets the required level of safety during both its operational and closure periods. Thanks to the technological advancement that has taken place in recent years, it has become possible to implement distributed wireless networks of low-power and low-cost sensors to monitor parameters of interest in different scenarios that relate to sectors such as the civil, environmental, and industrial ones. In this study an innovative approach for the identification and monitoring of the structural integrity of stored radioactive drums is presented. It consists of a network of radio frequency nodes equipped with solid-state gamma-ray and thermal neutrons detectors developed at the University of Pisa within the European project PREDIS. The nodes provide a unique identifier to the waste drums, and at the same time they allow cyclic measurements of the emitted radioactivity with a frequency and duration established by the user. Since nodes must be battery powered, a high level of hardware and software optimization has been performed to guarantee several years of battery lifetime minimizing human operators' interaction. Data collected by the nodes are automatically transferred to radio gateways through LoRa technology for visualization, processing, and storage purposes. The proposed solution demonstrates the possibility of collecting data automatically and passively from radioactive waste drums at a great distance without the use of mobile and/or mechanical scanning systems, enabling a much greater storage capability compared to common identification solutions based on radio frequency identification or near field communication tags.