This reference scenario describes an accident with a release of radioactive substances in a German nuclear power plant (before removal of fuel elements) whose radiological impact may require civil protection measures and radiation protection precautions.

This scenario would apply to serious accidents at those German nuclear power plants that are still in post-operation.

This reference scenario describes an accident at a foreign nuclear power plant situated near the German border, whose potential radiological impact may require civil protection measures and radiation protection precautions on German territory.

"Near the German border" means that the nuclear power plant is situated no further than 100 kilometres from German territory.

Locations of nuclear power plants in Europe | Data source: IAEA

This scenario would apply to the following nuclear power plants:

• Tihange (Belgium),
• Cattenom (France),
• Chooz (France),
• Leibstadt (Switzerland),
• Beznau (Switzerland),
• Gösgen (Switzerland) and
• Temelin (Czech Republic)

Small Modular Reactors (SMR)

There are efforts worldwide to develop and use so-called SMRs (Small Modular Reactors) for energy production in the future. SMRs are small, modular nuclear power plants. Various concepts for such small reactors are currently being developed in various countries.

The BfS is investigating the potential impact of a potential emergency on the surrounding area when it comes to the usage of SMRs. Initial assessments suggest that protective measures outside the actual facility may also be necessary. The BfS's investigations relate to a specific emergency procedure in a specific reactor type. Further specific investigations are necessary to obtain a plant-specific assessment of the hazard potential of SMRs. In general, the impact of emergencies in SMRs would likely be less than when it comes to the large nuclear power plants that are currently in operation.

Together with other national and international institutions, the BfS is monitoring current developments regarding SMRs. Emergency plans in Germany will be adjusted if further assessments indicate that protective measures in Germany may be necessary in the event of possible emergencies related to SMRs abroad (e.g. measures for agricultural products).

Background: For the large nuclear power plants that are currently in operation, the following protective measures could be necessary in the vicinity of the facility in the event of an emergency: evacuation, taking iodine tablets, and staying indoors. Precautions in the agricultural sector are also conceivable. The local civil protection authorities will decide whether and, if so, when these measures need to be taken and will provide information accordingly.

This reference scenario describes an accident leading to a significant release of radioactive substances at a nuclear power plant in Europe situated more than 100 kilometres from German borders.

The probability for civil protection measures and precautionary radiation protection measures to protect the population on German territory is lower due to the greater distance to German national territory, but not excluded. In particular, precautionary radiation protection measures in the agricultural sector may play a role, as shown by the example of the accident at the Chornobyl nuclear power plant in 1986, which occurred more than 1,000 km away from German territory.

Locations of nuclear power plants in Europe | Data source: IAEA

This emergency scenario would apply to nuclear power plants in the following countries:

• Belarus,
• Belgium (except Tihange),
• Bulgaria,
• Finland,
• France (except Cattenom),
• the Netherlands,
• the United Kingdom,
• Romania,
• Russia,
• Sweden,
• Slovakia,
• Slovenia,
• Spain,
• Czech Republic (except Temelin),
• Ukraine and
• Hungary.

Small Modular Reactors (SMR)

There are efforts worldwide to develop and use so-called SMRs (Small Modular Reactors) for energy production in the future. SMRs are small, modular nuclear power plants. Various concepts for such small reactors are currently being developed in various countries.

The BfS is investigating the potential impact of a potential emergency on the surrounding area when it comes to the usage of SMRs. Initial assessments suggest that protective measures outside the actual facility may also be necessary. The BfS's investigations relate to a specific emergency procedure in a specific reactor type. Further specific investigations are necessary to obtain a plant-specific assessment of the hazard potential of SMRs. In general, the impact of emergencies in SMRs would likely be less than when it comes to the large nuclear power plants that are currently in operation.

Together with other national and international institutions, the BfS is monitoring current developments regarding SMRs. Emergency plans in Germany will be adjusted if further assessments indicate that protective measures in Germany may be necessary in the event of possible emergencies related to SMRs abroad (e.g. measures for agricultural products).

Background: For the large nuclear power plants that are currently in operation, the following protective measures could be necessary in the vicinity of the facility in the event of an emergency: evacuation, taking iodine tablets, and staying indoors. Precautions in the agricultural sector are also conceivable. The local civil protection authorities will decide whether and, if so, when these measures need to be taken and will provide information accordingly.

This reference scenario describes an accident leading to a significant release of radioactive substances at a nuclear power plant outside Europe. Civil protection measures for the benefit of the population on German territory would not be necessary due to the long distance, and radiation protection precautions would not be required either.

However, contamination of vehicles (aircraft, ships, motor vehicles) as well as of persons and goods entering Germany cannot be excluded. Slight increases of the activity concentration in the air are also possible. German nationals in the country of the accident or its neighbouring states might also be affected so that it must be decided if travel warnings should be issued.

The following countries outside Europe operate a larger number of nuclear power plants:

• the USA,
• China,
• Russia,
• South Korea,
• India,
• Canada and
• Japan.

The International Atomic Energy Agency (IAEA) regularly publishes a list of the nuclear power reactors in operation worldwide.

This reference scenario describes an accident at a nuclear installation which is not a nuclear power plant in Germany or in other countries. These may be, for example,

• Research reactors,
• Uranium enrichment plants,
• Fuel element factories,
• Isotope production,
• Storage facilities for spent fuel elements or
• Nuclear power plants shut down after fuel-free operation.

The impact is limited to a much smaller scope than in the case of nuclear power plant accidents. Civil protection measures and radiation protection precautions may be necessary on a local scale.

The amount and composition of the radioactive substances released may differ significantly from those encountered in nuclear power plant accidents.

In Germany, this reference scenario would among others apply to

• the research reactors in Garching and Berlin,
• the Gronau uranium enrichment plant,
• various fuel element intermediate storage facilities (e.g. in Ahaus) and
• shut-down nuclear power plants after fuel-free operation (e.g. the Philippsburg NPP).

This reference scenario describes emergencies in which a deliberate (terrorist) crime or interference is committed against a stationary nuclear installation (nuclear power plants and other nuclear installations with an increased risk potential) and subsequent protective measures may be required.

The magnitude of the effects of a release of radioactive effluents within the meaning of this Reference Scenario may correspond to the potential effects of the scenarios described above in nuclear power plants and installations. The delimitation to these scenarios concerns in particular the terrorist background with the intention of harming persons, property or the environment.

This reference scenario describes an accident during the transportation of radioactive substances in which they are released (such as a road traffic accident). The consequences will probably be limited to a particular location.

Accidents can lead to the release of various radioactive substances, depending on the goods being transported, ranging from material needed for medical purposes to Castor transports of spent fuel elements. If a release occurs, it is likely to be rapid and of relatively short duration.

This referencence scenario describes a situation where an orphan (unregistered) radioactive source is discovered or where accidents occur during the handling of radioactive material.

The accidental melting of radioactive sources is also included in this emergency scenario.

The consequences of these events are limited to a very small scale. Typically, neither civil protection measures nor radiation protection precautions are necessary.

This reference scenario describes the crash of a satellite or spacecrafts containing nuclear or radiologically relevant material. There are currently almost 50 satellites of this description in Earth orbit. The radioactive substances are located in small nuclear reactors or in radioisotope batteries on board and serve to supply energy.

Although safety precautions are in place for satellites containing nuclear or radiologically relevant material, there have been isolated crashes in the past that resulted in contamination spreading over a relatively large area. A satellite crash over Germany is very unlikely. Modern satellites are usually deliberately brought down over the Pacific in areas with little ship traffic.

If a satellite crashes over land, it is unlikely that a large number of people will be exposed to increased radiation. Only persons remaining in the vicinity of particles from the reactor fuel or who are in direct physical contact with such particles would be exposed to increased external gamma and beta radiation from deposited radioactive material.

This reference scenario describes a situation where press releases or rumours indicate that a release may have occurred, for example subsequently to an accident at a nuclear installation, yet this is not confirmed.

This scenario includes, for example, the measurement of ruthenium-106 at numerous measuring points in Europe at the beginning of October 2017.

This reference scenario describes emergencies connected with the explosion of a nuclear weapon – especially in the case of accidental or deliberate incidents of a criminal or terrorist nature.

Nuclear weapons are weapons of mass destruction that use radioactive substances to produce a powerful explosion. In the event of such a blast, nuclear weapons can release not only radioactive substances and radiation but also a huge amount of energy as a result of nuclear fission or fusion processes. This energy is released in the form of an explosive effect consisting of a flash of light and a subsequent wave of pressure and heat, as well as a nuclear electromagnetic pulse that can disrupt or destroy electronic devices.

The distance at which a nuclear blast can have an effect depends above all on

• the blast yield of the nuclear weapon (TNT equivalent)
• the altitude of the explosion (on the ground or in the air).

The quantity and type of radioactive substances released in the blast can vary widely. In general, these substances are released very quickly and over a relatively short period of time (explosively). How far they can be dispersed in the environment following the blast also depends on current weather conditions (wind and precipitation).

As well as the consequences of the explosion itself, the radiological consequences for humans and the environment can also be devastating. In August 1945, nuclear weapons were used in Hiroshima and Nagasaki for the first and – so far – only time in a military conflict.