Enhanced search methods for finding and identifying radioactive material for on-site inspection deployment

The CTBTO verification system comprises an On-Site Inspection (OSI) to verify the suspicion of a banned nuclear test. An OSI comprises different methods of verification, one of them being the radiological survey of the inspection area. The radiological survey is done by airborne survey, carborne survey, and environmental sampling, thereby narrowing the inspected area with each step. Our institute operates a measurement car DeGeN (German acronym for Detection of Gamma and Neutrons) with highly sensitive neutron and gamma detection systems. In the present study we investigated the influence of the human factor by investigating measurement results obtained by a larger group of test persons operating our measurement car DeGeN.