Belgian Nuclear Center Tests Drone Radiation Mapping in Olen
Belgium’s nuclear research center SCK CEN is conducting field measurements with drones above the former bed of the Bankloop stream in Olen, testing advanced technology to map soil radioactivity more precisely and efficiently. The two-day exercise, which began on August 18, involves drones measuring radiation at various altitudes while researchers deploy ground-based equipment to calibrate the results, according to VRT NWS.
Why Olen Was Chosen
Olen was deliberately selected as the test site because its soil has been extensively studied due to historical radium contamination, providing a reliable reference for validating the new measurement methods. From 1922 until the late 1970s, Union Minière (now Umicore) operated a radium and uranium production facility in the town, becoming the world’s largest radium producer until the 1930s. Liquid effluents from the factory were discharged into the Bankloop stream, contaminating its sediments and banks with radium and other metals.
The Federal Agency for Nuclear Control (FANC) confirms that while significant volumes of radium-containing soils remain, there is no direct danger to the public—the D1 landfill site is fenced and inaccessible. The Bankloop stream itself was remediated in 2007, and Umicore states that all storage facilities are under control and pose no risk to human health or the environment.
“Due to historical radium production in the region, certain parts of Olen became lightly or more heavily contaminated,” said Johan Camps, radiation expert at SCK CEN. “Much remediation work has already been done and the Bankloop site has been extensively studied. We know that environment very well.”
Advancing Radiation Detection Technology
The drone program represents the culmination of years of development by SCK CEN in collaboration with Belgian aeronautical firm Sabca. The BUDDAWAK project, funded by the Energy Transition Fund of the FPS Economy, has been developing two types of radiation-detection drones since 2021: fixed-wing drones capable of staying airborne for hours to map large areas, and multicopter drones that can carry heavier detectors for localized measurements, as reported by SCK CEN.
The drones are equipped with scintillation detectors that measure radioactivity by counting light flashes caused by incoming ionizing radiation. Unlike traditional soil sampling, which requires bringing samples to a laboratory, drone-based measurements can cover larger areas much faster and transmit data in real time.
“It is a way to map radioactivity in the soil of a larger area faster,” Camps explained. “A sample can be a small pot of soil that can be examined very precisely in the lab. It takes much more time to map a terrain using that method.”
The technology’s potential was demonstrated in December 2022, when an X-8 multicopter drone successfully mapped radiation levels over the decommissioned BR3 reactor site in Mol, as World Nuclear News reported. The test flight identified the radioactive source, qualified and quantified the radiation, and produced a detailed visualization of contamination.
Overcoming Environmental Challenges
Field measurements present unique challenges compared to laboratory analysis. Environmental factors such as soil moisture can influence readings, and the drones must sometimes fly at varying altitudes due to obstacles like trees, which also affects results.
“The measurement is influenced by environmental factors, such as soil moisture,” Camps noted. “We sometimes have to fly higher because there are obstacles, sometimes even trees, and then you have to go to 20 to 25 meters altitude. Those different heights also affect the results.”
SCK CEN researchers are working to understand these environmental influences so that data can be correctly interpreted. The knowledge gained will be applied to other locations in Belgium and abroad where potential radium contamination exists.
Safety and Public Reassurance
SCK CEN has emphasized that the measurements are completely safe and purely scientific in nature. The drones do not collect photographic material, and the exercise does not alter the safety situation in any way.
“People absolutely should not worry,” Camps said. “We are only doing scientific research. We also do not collect photographic material, so nothing is filmed while we take our measurements.”
Broader Implications
The drone-based technology has significant implications beyond the Olen test site. As Belgium moves forward with the decommissioning of its nuclear power plants at Doel and Tihange, drone-based monitoring will be crucial for safely assessing radiation levels during dismantling operations. The technology could also be deployed internationally at other contaminated sites, and EOS Wetenschap noted that drones could serve as unmanned aerial support during nuclear emergencies, protecting public health without risking human exposure.
“Above all, there is no longer any need for human intervention in high-risk areas, so you protect yourself at all times while being able to measure much longer, cheaper and better,” said Geert Olyslaegers, SCK CEN researcher and drone pilot, as reported in SCK CEN’s 2021 annual report.
The project also builds on earlier milestones, including the March 2021 presentation of the first radiation-detection drone and the May 2021 official launch of the BUDDAWAK program, which was attended by Interior Minister Annelies Verlinden. At the time, Verlinden expressed full support for the initiative, stating that “innovative projects for better protection of the population, the environment and employees enjoy my full support,” as reported by VRT NWS.
What’s Next
The Olen measurements represent a significant step from laboratory testing to real-world field deployment at an actual contaminated site. The results will be compared against decades of soil sampling data from the area, providing a rigorous validation of the drone technology.
As SCK CEN continues to refine its measurement methods, the technology’s potential applications are expanding—from routine environmental monitoring to emergency response and nuclear facility decommissioning. The knowledge gained in Olen will help determine whether drone-based radiation mapping becomes a standard tool for environmental monitoring in Belgium and beyond.
While specific results from the Olen measurements have not yet been published, the exercise marks an important milestone in demonstrating that drone technology can deliver the precision and reliability needed for regulatory-grade environmental monitoring.