Indoor UAV for Nuclear Investigation: Experimental Qualification and Field Feedback

ABSTRACT

Indoor Unmanned Aerial Vehicles (UAVs) have recently gained interest for inspection and investigation tasks in hazardous environments. In the nuclear field, indoor UAVs offer promising capabilities to reduce workers' exposure to ionizing radiation while accessing confined or elevated areas. However, their actual operational performance and limitations in nuclear facilities remain poorly documented in the peer‐reviewed literature. This field report documents operational experience from the deployment of an indoor UAV for nuclear investigation at CEA Marcoule (G2/G3 reactor buildings). A four‐level qualification workflow—laboratory functional tests, representative‐site trials, radiological characterization, and active‐facility campaigns—is described to support reproducible field deployment planning rather than to claim methodological novelty. Over approximately 100 flights, the platform inspected 2500 m ² of cladding in 6 half‐days (45 flights), identified 26 points of interest, and achieved photogrammetry accuracy error of about 1% on dimensional references; source‐search trials located a ¹³⁷ Cs test source in all four blind tests within two flights on average. The report concludes that indoor UAVs are operationally relevant for rapid visual investigation and qualitative radiological indication in moderate‐dose, low‐dust environments, but are unsuitable as universal investigation tools: battery life is 10 min (reduced by 10%–15% with the dose‐rate payload), dust resuspension can abort missions, transmission fails behind thick shielding, and commercial electronics require conservative cumulative‐dose management. Indoor UAVs should be positioned as complementary to ground robots (RICA, Vega) and wired inspection means, selected according to accessibility, dose, contamination, and acceptable equipment loss.