Integration of independent NDA techniques within a SLAM-based robotic system for improving safeguards standard routines: a review of the current status and possible future developments

Agencies devoted to safeguard and non-proliferation make large use of techniques based upon non-destructive assays (NDA) systems for ensuring the correctness of operator declarations about a facility inventory or for gathering data during inspections. The data ensemble to analyse consists of many aspects, but it is mainly focused on radiological data. De facto, systems used for NDA radiological characterization are optimized for precise goals in order to maximize their efficiency and ease of use, at the expense of versatility and more complete (although complex) results. Nevertheless, this approach may encounter several limitations due to the intrinsic properties of the techniques involved. For example, proper background estimation and subtraction in a gamma spectrometry are not always possible, either due to photons mean free path in matter or to the possible inability to suppress external contributions by placing the detector close to the item in object. A Concept of a modular, multi-sensor system is presented, where the results of radiological and non-radiological assays are automatically integrated in a 3-dimensional model created by means of novel results in robotics and optical sensors. This review paper reports and discuss the state-of-art in the implementation of systems similar to the Concept presented, as the idea behind the Concept has already been tested in recent years with promising results; nevertheless, technology develops fast in the field and new future implementations, improvements and applications in safeguards and non-proliferation are wor th to be envisaged, presented and discussed. For example, some of the Concept sensors can also be used as a stand-alone detector, with a natural gaining in the Concept versatility: a high-resolution gamma spectrometer can be used to measure Plutonium isotopic composition or Uranium enrichment. Moreover, results obtainable through the Concept can be used to create a digital twin of a generic component, system, or facility, complete with several radiological and non-radiological data, resulting in a dramatic step forward in the implementation of the Building Information Modelling (BIM) standards.