Measuring campaign in Germany in 2009

In order to enhance the cooperation between measuring teams from France, Switzerland and Germany, an aero measuring campaign was performed in the Munich area in 2009. Measurements focused on the following tasks:

• Finding radioactive sources placed in vehicles that were driven over a specific distance within a specific period of time;
• Finding hidden radioactive sources;
• Large-scale mapping of natural radiation anomalies.

Spatial distribution of the mass-related activities of thorium-232 in the survey area near the town of Neunburg vorm Wald (German team)

An area covering 90 square kilometres near the town of Neunburg vorm Wald was examined for the third task and a map was created showing the radionuclides thorium-232, bismuth-214, potassium-40 and the gamma dose rate. The teams had to meet the following requirements: 3 hours operation time in the survey area, flying at a height of 100 metres and keeping a distance of 370 metres between flight paths.

Comparison of the averaged mass-related activities of potassium-40, bismuth-214, thorium-232 and the gamma dose rate, determined by the three teams

The teams transmitted the measured data to the operation centre in Munich soon after they had completed the measuring flights in the relevant areas. The measured data was combined with geographical maps, as illustrated in the figure on the left-hand side. The figure on the right-hand side shows the averaged mass-related activity concentrations for the radionuclides to be measured in the survey area. The measured results are comparable and in good agreement, taking the methodological uncertainty into account.

According to the participating experts and observers, in particular this part of the exercise has shown that helicopter-based measuring systems are extremely powerful in identifying and localizing large-scale environmental contamination.

Measuring campaign in Switzerland in 2007

In August 2007, the tri-national measuring campaign “ARM07” was conducted in the area of Zurich and Basel. This measuring exercise was focused on:

• Radiological mapping of the areas surrounding the nuclear installations of Gösgen and Mühleberg (comparison measurements);
• Vehicle- and helicopter-based search for several radioactive sources placed on the premises of the freight terminal of Basel railway station in Muttenz; and
• Joint radiological mapping ("composite mapping") of the border triangle near Basel.

The survey area chosen for the radiological mapping activities comprised three measuring areas (with roughly the same dimensions) situated on the territories of the three participating states, as can be seen in the figure on the left-hand side (F is for France, D for Germany and CH for Switzerland). The spatial distribution of the gamma dose rate is shown in the figure on the right-hand side.

Measuring areas for composite mapping around Basel Source: Measuring flights 2007, 27 - 30 August (National Emergency Operations Centre, Switzerland)

Terrestrial portion of the gamma dose rate Source: Measuring flights 2007, 27 - 30 August (National Emergency Operations Centre, Switzerland)