This was the mission undertaken by Prof Tom Scott, with a team from Bristol University and the NCNR (National Centre for Nuclear Robotics). The NCNR is a UK nationwide consortium of research experts tasked with developing the next generation of technologies that can be used to clean up Britain’s 4.9-million tonnes of legacy nuclear waste. They are specialists in robotics, artificial intelligence (AI)/machine learning, sensors, electronics, and materials working across eight institutes, centred on a hub at the University of Birmingham.
A fixed winged solution
Fixed wing UAVs provide several advantages over rotary UAVs:
- Longer flights
- Faster flights
- Can typically carry a heavier payload
In this case, a fixed-wing drone was outfitted with two Kromek Sigma 50 radiation detectors. The Sigma 50 is a scintillation detector using CsI(Tl), thallium activated caesium iodide crystal. CsI(Tl) has a light output of 54 photons/keV and is one of the brightest scintillators known. The Sigma 50 itself is robust and can survive in the field and does not require any cooling. The team already had experience of using Sigma 50s in rotary UAV drones.
The fixed-wing drone proved itself up to the task. It gave the team longer flight durations at higher speeds, enabling larger survey areas per given flight. Therefore, these drones were first used to make a general radiation map. To do this, they flew at about 40mph (65km/h) just above the treetops, in a grid pattern, flying 50 missions over ten days. Subsequently, places of interest were then followed up with rotary-wing drones (UAVs). They allowed the radiation detectors to take more precise measurements by hovering over the area of interest and using their sensors to acquire high-resolution, 3D information.
Overall, the survey confirmed that the forest had the expected levels of radiation present. Due to the work of the group, this was now mapped in much more detail. Additionally, the new survey revealed several areas of high radiation levels.
You can hear Tom Scott talk about the mission with the BBC here: https://www.bbc.co.uk/news/science-environment-48193866
