14 Platform one Createc has used a robot dog and a mesh radio network to create a real-time map of a radioactive power plant, writes Nick Flaherty. The N-Visage Explore (NV-X) system has a sensitive gamma radiation camera mounted on a robot dog for real-time radiation mapping. A multi-floor, nuclear-material processing cell at Dounreay in Scotland remained sealed for over 25 years in a non-operational state. Lack of information on the contamination and dose rates within the cell presented an obstacle to the nuclear decommissioning process, requiring a comprehensive understanding of the cell’s condition before any work could commence. While estimated to be in singular mSv/h, the exact radiation levels could not be confirmed, so remotely operated robotic surveys were necessary before human operators could enter safely. Restricted access between the levels, narrow walkways and inadequate lighting posed additional challenges. To reach areas beyond the ground floor relied on An ad-hoc Rajant Kinetic Mesh was set up by using another OSE product, the Smart PoE Powerbank, which was designed for this application to power and link the mesh relay nodes. ES1 radio nodes were mounted on the Smart PoE Powerbanks, and another Spot, this time with a manipulator arm, was used to carry them into place. The Powerbanks have onboard computers, which allow them to report the battery state back to the user, as well as additional sensor data, and they last for up to four days. The Spot with the arm conducted swab sample return missions, inspected objects with the PTZ camera and retrieved the Rajant Kinetic Mesh radios at the end of the deployment. The Spot with NV-X conducted 3D laser scans and radiometric survey missions throughout the four floors of the cell, which were combined into a single model of the cell in post-processing. The NVisage radiation-mapping algorithms produced a 3D reconstruction of the radiation sources and dose planes for the cell, which have proven valuable for decommissioning planning. Robots Mapping a power plant staircases within the cell that were not easily accessible by ground-based robots. The concrete walls and metal structures made wireless communications difficult, posing the challenge of remotely operating the robots with conventional radio. The NV-X system was mounted on a Boston Dynamics Spot robot, which can move upstairs and across debris. It was equipped with a custom lighting unit and contamination control suit. This prevented the robots from ingesting contamination that would prevent them being released from the Dounreay site. Integral to Spot’s onboard equipment was Rajant Kinetic Mesh ES1 BreadCrumb radio for robotics operations beyond visual line-of-sight (BVLOS), using a dual-radio setup with high-gain antennas and a small form factor. It was linked to Spot using a Robot PoE Switch, designed and made by Createc spin-out company, OSE. The switch provides power regulation from Spot’s payload power bus (48-72 V), networking with Spot via a four-port Ethernet switch, power to the Rajant ES1 via passive PoE, and a PoE+ port for additional sensors. June/July 2024 | Uncrewed Systems Technology Radioactive monitoring by a four-legged robot (Image courtesy of Createc)
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