A prototype configuration of an Elios 3 indoor inspection drone, made by Flyability, comprising a lightweight light detection and ranging (LiDAR) system and a wide-range, electronic dosimeter was developed and tested to quickly measure radiation levels and collect three-dimensional (3D) spatial data from within a very high radiation nuclear waste storage facility at the U.S. Department of Energy−operated Idaho National Laboratory (INL) site.

The compact drone configuration was used for inspecting and collecting data from areas difficult or hazardous to access using conventional methods. Validation testing of the prototype drone configuration was performed, including maneuverability, radiation tolerance, dosimeter integration, and elevated ambient temperature testing. The drone configuration was shown to operate successfully in an ionizing radiation field as high as 100 Gy/h (10 000 rad/h), with an accumulated radiation dose of 40 Gy (4000 rad) and ambient air temperatures of 54°C (130°F).

On November 16, 2022, the LiDAR and dosimeter-equipped prototype drone was used to successfully collect 3D spatial data and radiation measurements from within a very high radiation nuclear waste storage facility at the INL site, where it encountered radiation levels up to 7 Gy/h (700 rad/h). The mission, which included three flights of the prototype drone configuration, represents the first-ever drone flight within a very high radiation nuclear waste storage facility. On the third flight into the storage facility, the drone was unable to produce adequate lift necessary to fly back out of the facility.

The lessons learned suggest the loss of adequate lift was due to the added weight of the dosimeter payload and the increasing temperature of the air inside the facility due to radioactive decay. Although the prototype drone was not retrievable, the drone’s wireless transmission system successfully transmitted the radiation measurements to engineers outside of the facility.