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Ionising radiation

Environmental Radioactivity - Medicine - Occupational Radiation Protection - Nuclear Hazards Defence

Ionisierende Strahlung

Industrial residues (NORM)

Here you will find information on residues from industrial processes with enhanced natural radioactivity (NORM).

What are NORM residues?

Radionuclides of the naturally occurring decay chains of uranium-238, uranium-235 and thorium-232 are present in traces in all rocks and mineral ores. So when using raw materials like rocks and mineral ores, natural radionuclides are generally introduced unintentionally into industrial processes. In some branches of industry, natural radionuclides can accumulate in parts of the material flux. In specialist literature, these residues are often referred to as "naturally occurring radioactive materials" ("NORM" for short).

Iron slurrySource: © Bavarian Federal Office for the Environment

Residues from water treatment facilities

In water treatment facilities, radionuclides previously dissolved in untreated water can accumulate as an undesired side effect in treatment residues. Depending on the treatment process and on the untreated water composition, residues can arise with an enhanced natural radionuclide content. These arise primarily in the processing of groundwater. For current recycling options, the Federal Office for Radiation Protection (BfS) has estimated the radiation exposure for workers and the general public.

ScalesSource: Source: Verein für Kernverfahrenstechnik und Analytik

Residues from deep geothermal energy

When extracting deep water for energy production, natural radionuclides dissolved in water reach the surface. Depending on water composition and plant control, residues may precipitate inside the plant. The radionuclide content (specific activity) of these residues exceeds the natural background of soils many times. Such residues result primarily from the use of deep water with a high salinity of up to 300 grams salt per litre of water.

NORM: Further information for specialists

Compared to the natural background content of soils, NORM show an enhanced content of naturally occurring radionuclides. Here, we offer assistance to estimate the radiation exposure of workers in relevant industrial sectors involving NORM as well as in recycling or disposal facilities in Germany. Depending on the recycling option, a dose estimation for members of the public has to be taken into account.

© Bundesamt für Strahlenschutz