Federal Coordinating Office for questions of monitoring of the radioactivity at enhanced natural radioactivity (ENORM)

Natural radionuclides are ubiquitously in small quantities and contribute to the environmental radioactivity at working places and in the environment. The different geological conditions in Germany (coastal lowlands, low mountain ranges, Alpine foothills, Alps) result in different levels of natural radionuclides. The extraction and processing of raw materials (ores, building materials, oil or gas) can lead to enhanced specific activities of the natural radionuclides.

As part of the nationwide monitoring of the environmental radioactivity, the legislative authority established the Federal Coordinating Office for questions of monitoring of the radioactivity at enhanced natural radioactivity (ENORM) at the Federal Office for Radiation Protection (BfS) in 2002.

Sample preparation centre

At the sample preparation centre, the incoming materials are initially documented in a data base.

Among others, the following is treated:

• Soils and sediments,
• Food and feed,
• Drinking water and groundwater,
• Surface water, seepage and waste water,
• Sludge, deposits, dusts and similar materials from the industry as well as
• building materials.

The materials are treated in compliance with the requirements of the following measurement methods. They are, e.g., dried, sifted, crushed, incinerated, and/or aliquoted, i.e. portioned and split into the amounts to be examined.

The centre is especially equipped for the treatment of samples that are subsequently examined with the help of gamma spectrometric analyses.

Gamma spectrometry laboratory

High-purity germanium detector with automatic sample changer

In the gamma spectrometry laboratory, gamma radiation is measured with high-resolution germanium detectors. The laboratory equipment and the measurement technology allows to detect even very low activities of natural radionuclides in the samples (low-level-measurement laboratory).

Gammaspectometry analysis enables the identification of individual radionuclides in the sample material (gamma emitters) and to determine their respective specific activities.

Radon calibrating laboratory

To ensure the quality of devices measuring radon and radon decay products, the Federal Office for Radiation Protection (BfS) maintains an accredited calibration service laboratory for the measurands

• activity concentration of radon-222 in air and
• potential alpha-energy concentration of short-lived radon-222 progenies.

The calibration of the measuring devices is traced back to national primary standards provided by the Physikalisch-Technische Bundesanstalt (PTB).

Accreditation is granted by the German Accreditation Body.

Service centre dosimetry

Measuring devices, especially those for gamma dose rate, are used to determine the radiation dose rate in many different spheres of life. Reliable and verifiable measurements can only be granted if function and calibration are examined on a regular basis. This is done by the service centre dosimetry of the BfS in Berlin.

The examinations serve internal quality assurance purposes and are carried out to the calibration of the devices according to the German Weights and Measures Act. The devices used by the BfS are calibrated on a regular basis and in compliance with the provisions for official measurements.