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Ionising radiation

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

Ionisierende Strahlung


The reactor disaster in Chernobyl in the Ukraine occurred on 26 April 1986. Large amounts of radioactive material were released which distributed over the northern hemisphere. The radioactive contamination in the affected areas resulting from this varied considerably, depending on the occurrence and level of precipitation during the drifting of the radioactive air masses. As a result of the Chernobyl accident many countries have updated their programmes for the protection of the population from radioactive radiation.

Handheld measuring device used to determine the ambient dose rate in front of the Chernobyl reactor. The display shows a value of 3.04 microsievert per hour.

The Chernobyl accident

The accident occured in unit 4 of the Chernobyl nuclear power plant - a reactor type of Soviet design. The reactor was in the phase of slow shutdown. At the same time an experiment was planned for checking various safety features. Basic design failures of the plant in combination with failures and offences in operational management led to the reactor desaster.

View onto Dnepr

Health consequences in former Soviet Union

After the Chernobyl reactor accident, the emergency forces as well as the local population were exposed to high levels of radiation. Especially plant personnel, firefighters, rescue forces and clean-up workers (so-called liquidators) received high radiation doses. Considerable radiation exposures to the population were recorded particularly in the areas of present-day Russia, Belarus and Ukraine. The resulting health consequences are still being investigated to this day.

Contamination Probe

Accident management: Consequences for Germany

If there is an accident in a nuclear power plant there are required disaster protection measures in Germany. The "Basic Recommendations for civil protection in the vicinity of nuclear facilities" and the "Radiological basis for decisions on measures to protect the population against Accidental Releases of radionuclides" regulate these measures. For the implementation of these measures, such as evacuations, the federal states ("Länder"), the counties and independent cities are primarily responsible. The Federal Office for Radiation Protection (BfS) assists the federal states in evaluating the radioactive release.

Wild Boar

Environmental consequences

Radioactive caesium (caesium-137 and caesium-134) and iodine (iodine-131) were particularly significant for the radiation exposure of the population as a consequence of the reactor disaster of Chernobyl. Today virtually only the long-lived caesium-137 is significant for Central Europe. Due to its half-life of about 30 years this radionuclide has only decayed by about half from 1986 until now.

Landscape with oak

Health consequences in Europe

After the Chernobyl reactor accident areas outside the former Soviet Union especially in Central Europe, South East Europe and parts of Scandinavia were affected by the reactor accident. To date, there is no evidence that the reactor accident has caused adverse radiation health effects in Germany.

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