Helicopter exercise: Detection of airborne radiation by Federal Office for Radiation Protection and Federal Police

Within the scope of a joint exercise in Schleswig-Holstein and Lower Saxony, the Federal Office for Radiation Protection (BfS) and the Federal Police (BPOL) are going to practise the helicopter-launched detection of environmental radioactivity from 24 to 28 September 2012. The exercise is a precautionary measure: Based on this detection procedure, BfS and BPOL will be able to assess the distribution of radioactive substances in the environment rapidly and over a wide area, if necessary. This could, for example, be required in the case of an accident in a nuclear power plant (NPP) associated with releases of radioactive substances.

Objective of the exercise

The annual detection exercises serve to optimize the detection and evaluation procedures and to inspect their readiness for use. In addition, the co-operation between the task forces from the Federal Police and the scientific-technical staff of the Federal Office for Radiation Protection is practised and improved.

Subsequent to the exercise, the data collected will be made available to the competent authorities in Schleswig-Holstein and Lower Saxony. The areas for this exercise were determined by the Federal Office for Radiation Protection, covering particularly the areas around the nuclear facilities in Schleswig-Holstein. In the previous year, the surroundings of the nuclear facilities in Baden-Wurttemberg were overflown within the scope of the exercise.

Course of exercise

Within the course of the exercise, test flights are expected to be performed on 24 September from 2 to 5 p.m. near Stade. From 25 to 27 September measurements will be made from 8 a.m. to 5 p.m. in the surroundings of the nuclear power plants Brunsbüttel, Brokdorf, Krümmel and the former NPP Stade. The exercise is weather-dependent, and the detection flights therefore might be continued up to 28 September. For metrological reasons, the flight altitude will be about 100 metres as a general rule.

For the purpose of the exercise, two helicopters of the Federal Police will be equipped with specialized measuring instruments to detect gamma radiation. In addition to the measurement data, the geographic coordinates will be recorded as well, so that the spatial distribution of the radioactive substances detected can be diagrammed immediately after conclusion of each detection flight.

Detection of airborne radiation

Airborne radiation detection, also referred to as aerogammaspectrometry, enables detection of radioactive sources and rapid measurement of a large area for potential radioactive contaminations. Thereby, an area of 70 square kilometres can be explored within three hours. Rapid decision-making on required emergency protection measures of the public can thus be supported and the necessity of more detailed examinations on the ground justified.

According to the Precautionary Radiation Protection Act, the Federal Office for Radiation Protection is responsible for rapid and large-area determination of airborne radioactivity at ground surface. The Act was passed in the aftermath of the Chernobyl reactor accident in order to keep radiation exposure of the general public as low as possible in the case of events involving considerable radiological consequences. In order to realise this task, the Federal Office for Radiation Protection has a total of four measurement systems at the offices Munich and Berlin available. These systems can be mounted in the helicopter of the Federal Police within half an hour and subsequently be moved to an area under investigation.