Evaluation of a Continuous Air Monitoring System on an Unmanned Aerial Vehicle for Measurement of Airborne Radioactive Material

The release of airborne radioactive material presents a health risk hazard to many individuals, emergency responders and public. It is necessary to characterize the unknown radioactive dangers produced in the event of these incidents. Advantages to utilizing unmanned aerial systems in this effort are personnel risk reduction and quick attainment of data points in a plume. By pairing a continuous air monitor and detector with a drone, radioactive material concentration can be quantified, and thus the extent of potential doses can be estimated. A small, low-flow air sampler with a Geiger-Mueller counter was characterized using measurements of sources representing a cloud of material and modelled using MCNP to find the usefulness of the system for detection of nuclides of concern. The flying time and payload weight capacity limit the minimum detectable activity concentration possible over the window of operation of the system. It was found that activity concentrations corresponding to external and internal doses of concern can be detected through use of this system with certainty for 90Sr and 137Cs in a plume, while those corresponding to 241Am and 238Pu are more difficult to detect. This technical basis supports use of this system after nuclear power accidents, where fission and activation products may be released, but shows the limitation for application of detection of airborne special nuclear material