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Ionising radiation

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

Ionisierende Strahlung

Monitoring the emission of radioactive materials from nuclear facilities

  • The discharges of radioactive materials from nuclear facilities (emission) through exhaust air and waste water are regularly and permanently monitored and assessed.
  • The activity discharges calculated within the framework of the "exhaust air" and "waste water" emissions monitoring are communicated according to legal provisions to the Federal Environment Ministry and to the European Commission.
  • In addition, the reported activity discharges are documented in the BMU annual report "Umweltradioaktivität und Strahlenbelastung" (Environmental radioactivity and radiation exposure).

The discharges of radioactive materials from nuclear facilities (emission) through exhaust air and waste water are regularly and permanently monitored and assessed. The resultant radiation exposure of the population is deduced from this. In addition, the atomic licensing authorities stipulate maximum values for the discharges from nuclear facilities.

The operator of the nuclear facility is thus obliged

  • to minimise the discharges and
  • to determine, document and asess all discharged radioactive materials by type and activity (known as "self-monitoring").

The required measurements are documented and a report is submitted to the relevant supervisory authority.

Diagram of sampling equipment in a German nuclear facility Sampling equipment for emissions monitoringDiagram of sampling equipment in a German nuclear facility

Radioactivity discharges in exhaust air

Radioactive materials are carried into the environment by exhaust air via the stacks of nuclear facilities.

A representative proportion of the exhaust air is continually directed through collection equipment for assessment (see adjacent diagram).

After previously determined periods, the activities of the radionuclides that have settled during this time in the collection medium are determined and the resultant activity concentrations of these radionuclides in the exhaust air are calculated. As this type of sample collection is known as an "integrated procedure", short term emissions are also recorded reliably.

In addition, so-called "Online Monitoring Equipment" continually monitors radionuclides emitting gamma radiation (for example cobalt-60) and iodine isotopes. These measurements enable the prompt recognition of increases in activity discharges and furthermore ensure the recording of short-life radionuclides such as iodine-133.

Radioactive noble gases can only with great effort be deposited on collection media. In order to record them, a representative proportion of the stack exhaust air is directed continuously through a measurement chamber. In this way, activity discharges of these noble gases can be continually calculated and assessed.

Activity discharges in waste water

In contrast to exhaust air, all radioactive waste water must be collected in collection containers. Only when an arbitration measurement has indicated that previously set permission values are not exceeded can it be directed into the environment through an outlet channel.

The operator determines the activities in the waste water of

  • alpha emitting,
  • beta emitting and
  • gamma emitting radionuclides.

The discharged radioactive materials are assessed.

Activity discharges of individual radionuclides and radionuclide groups in exhaust air and waste water 1962 - 2015 Activity discharges of individual radionuclides and/or radionuclide groups to 2015Activity discharges of individual radionuclides and radionuclide groups in exhaust air and waste water 1962 - 2015, summarised annually across all German nuclear power stations under the scope of Atomic Law

Overview of activity discharges from nuclear facilities in Germany

Since the 1960s, assessment has taken place of radioactive materials in exhaust air and waste water. Excepting the discharge of tritium (H-3) in the waste water and carbon 14 (C-14) in the exhaust air, all other radionuclide groups have been in decline since the 1970s.

This has been induced on the one hand by the shut down of nuclear power stations – in 1993, 20 nuclear power stations were in operation, in 2015 only seven – and on the other hand, facilities have been retrofitted with retaining equipment for radioactive materials in the exhaust air (known as "full filtration").

Report submission is a legal requirement

The activity discharges calculated within the framework of the "exhaust air" and "waste water" emissions monitoring are communicated according to legal provisions to the Federal Ministry for the Environment, Nature Conservation and Nuclear Safety (BMU) and to the European Commission.

In addition, the reported activity discharges are documented in the BMU annual report "Umweltradioaktivität und Strahlenbelastung" (Environmental radioactivity and radiation exposure).

Environmental radioactivity and radiation exposure: Annual reports (in German only)

State of 2017.05.09

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