Measuring radioactivity from helicopters: specialist training at Freiburg

Radioactivity measurements using a Federal Police helicopter

The Federal Office for Radiation Protection (BfS) and the Federal Police will carry out exercises in the vicinity of Freiburg from 4 to 6 July 2023 in order to train their personnel to measure radioactivity on the ground from helicopters. To do so, specialists from the BfS install their measurement technology in Federal Police helicopters. Joint measurement exercises are held on a regular basis in order to ensure smooth collaboration with pilots in the event of a real-world deployment.

If radioactive substances enter the environment, e.g. due to an accident at a nuclear power station, they can spread over large areas – including across borders. In such cases, the authorities need rapid access to reliable information regarding contamination on the ground surface in order to effectively protect the population.

This information can be provided by measurements taken from helicopters, allowing rapid determination of,

• whether and how badly an area is affected,
• what radioactive substances have accumulated on the ground and
• in what quantities.

Training flights detect naturally occurring radioactivity

Overview map of the measurement areas

During the exercise, the naturally occurring radioactivity on the ground will be recorded and mapped by systematically overflying a total of four measurement areas. One of the areas – centred around Breisach – runs directly along the Rhine. Three further areas lie to the north-east and south-east of Freiburg in the Black Forest. The measurement flights will depart from Freiburg Aerodrome.

Measurements will be taken between 9:00 am and 5:00 pm on all three days and will involve two Federal Police helicopters overflying the measurement areas at a height of approximately 90 metres. During the exercises, personnel will train to carry out various operating procedures. For example, the teams from the BfS and the Federal Police can analyse the measurement areas by following parallel or helical flight paths.

Collaboration between the BfS and the Federal Police

For many years, the BfS and the Federal Police have worked closely together on the helicopter-supported detection of radioactive substances on the ground: the Federal Police provides the helicopters and crews, while experts from the BfS carry out the measurements and ensure the radiation protection of all participants.

In a radiological emergency, an area of around 100 square kilometres can be flown over and mapped within approximately three hours. The measurement results are available shortly after landing.

Measurement areas in detail

Measurement area 1 (Denzlingen – Waldkirch – Elzach) lies to the north-east of Freiburg and measures around 20 x 20 kilometres. Within the area lie the municipalities of Freiamt to the north-west, Elzach to the north-east and Simonswald to the south-east. The area concludes in the south-west with Denzlingen and parts of Gundelfingen. Other towns and municipalities within the survey area include Waldkirch, Gutach im Breisgau and Winden im Elztal.

Measurement area 2 (Schauinsland) measures approximately 10 x 10 kilometres. Lying to the south-east of the Freiburg urban area, it encompasses the St. Lioba monastery to the north-west, Kirchzarten in the north-east, St. Wilhelm (Oberried) in the south-east and Freiburg's local mountain, the Schauinsland. It also includes Oberried and Horben.

Measurement area 3 (Breisach am Rhein) covers an area of some 10 x 20 kilometres running along the Rhine to the west of Freiburg. To the north, the area ends just beyond Vogtsburg im Kaiserstuhl. To the east, it is delimited by Bötzingen, Waltershofen and Mengen. At its south-eastern corner lies the town of Bad Krozingen. The survey area also takes in Breisach am Rhein, Ihringen, Merdingen and Hartheim am Rhein.

Measurement area 4 (Bernau im Schwarzwald) is located to the south-east of Freiburg between Todtnau in the north-west, the Schluchsee in the north-east and St. Blasien in the south-east, all of which lie just outside of the area. Within the approximately 10 x 8 kilometre area lie Bernau im Schwarzwald, Präg and Menzenschwand.