Experiences as an observer of the CTBT on-site-inspection exercise DE07 in Chernobyl

The directed exercise DE07 took place in the Chernobyl exclusion zone in the Ukraine from 4. June 2007 to 14. June 2007. The aim of the exercise was to train several aspects of an On-Site-Inspection (OSI) to provide evidence of a forbidden nuclear weapons test in the context of the preparation of the Comprehensive Test Ban Treaty (CTBT). I had the opportunity to join the exercise as an observer. 25 experts from 22 state parties took part in the exercise. In addition 4 observers from 4 countries participated. The aim of the directed exercise was to measure radioactivity levels in a simulated inspection area and to identify the nuclides. The following aspects of an OSI were trained: carbone and airbone gamma survey; environmental samplilng and analysis in a field laboratory; safety of work, personal protection and decontamination; communication and navigation in the field; data preparation and data handling.