Radiation is a form of energy dispersing as electromagnetic wave - or as particle radiation - through room and matter.

Exposure refers to the totality of all environmental impacts (biological, chemical or physical) to which items or living organisms, especially humans, are exposed. If the impact is radiation, it is called radiation exposure.

In the case of humans, a distinction is made between

• external radiation exposure, if the radiation source is outside the body, and
• internal radiation exposure, if the radiation source, e.g radionuclides, is incorporated through breathing (inhalation), through food or drinking water (ingestion) or through open wounds.

Prerequisites and measures to protect humans against the effect of harmful ionizing and non-ionizing radiation.

Radiation is a form of energy that propagates as electromagnetic waves – or as particle radiation - through space and matter.

In the definition given in the Atomic Energy Act (AtG), those substances are termed "radioactive substances" whose content of radionuclides cannot be disregarded. Values occurring below legally specified exemption levels can be disregarded as defined by the AtG. One differentiates between nuclear fuels and other radioactive substances.

The scale for the classification "radioactive" is the exceeding of the exemption levels according to the provisions of the Radiation Protection Ordinance. All substances containing radionuclides must be classified as "radioactive" if their activity (that is, the number of nuclear transformations of a radionuclide or radionuclide mixture occurring per time unit) exceeds the exemption levels mentioned.

Radioactive substances in the sense of Section 2 Para. 1 of the Atomic Energy Act, which have to be properly disposed of according to Section 9a of the Act.

The property of particular atom nuclei (radionuclides) to transmute into other atomic nuclei without any external influence and emit ionising radiation in the process. The measured quantity is the activity, i.e. the number of nuclear decay processes in a radionuclide or a mixture of radionuclides during a particular time. The unit is the becquerel (Bq), which corresponds to one nuclear decay process per second. There are both natural radionuclides in the natural world and artificial radionuclides formed by nuclear physical processes. Each radionuclide has a half life.

The Reactor Safety Commission (Reaktor-Sicherheitskommission - RSK) was established by statute in 1958. The Commission advises the Federal Ministry responsible for nuclear safety and radiation protection (BMUV) in safety-related matters and thus matters concerning the physical protection of nuclear installations and radioactive waste management. Since the establishment of the Nuclear Waste Management Commission (Entsorgungskommission - ESK) in 2008, radioactive waste management has become a topic of consultations of the ESK.

As result of their meetings, the RSK passes technical-scientific recommendations or statements that are submitted to the BMUV. In principle, the RSK assesses issues raised by BMUV, but the Commission may also address topics for advice on its own.

The way of working of the RSK is regulated by a Statute. A secretariat established at BASE supports RSK`s advisory work. The web site of the RSK provides information about RSK and its recommendations and statements.

Once the high-level radioactive waste has been put into a disposal site, all the shafts and access points at the site will be filled and sealed. According to the Site Selection Act, it should be possible to recover the waste from the disposal site, access it and bring it to the surface again during the next 500 years. It is therefore necessary to know the precise location and properties of the waste. The casks must therefore be suitable for retrieval and still be intact after the stipulated period.

Escape of radioactive substances from the planned enclosures into the facility or the environment.

Site for the safe and maintenance-free storage for an unlimited period of time of hazardous materials in deep geological formations.

Combination of physical and chemical separating procedures through which uranium and plutonium (in the form of chemical compounds) are retrieved from spent fuel elements and the high-radioactive waste is separated. On a large technical scale mainly the so-called PUREX method is used for reprocessing (Plutonium Uranium Reduction Extraction Method).

Between 1971 and 1990, in Germany,spent fuel elements were reprocessed for test purposes in a pilot plant (Karlsruhe reprocessing plant, WAK). Reprocessing operations were discontinued at the end of 1990. The facility was decommissioned andis presently being dismantled.

Plant for the chemical treatment of spent reactor fuel after its use in a nuclear power station to separate the remaining uranium and the newly created plutonium from the fission products, i.e. the radioactive waste.

Disposing of all the containers with high-level radioactive waste and gradually backfilling the disposal area will take several decades. The Site Selection Act states that it must be possible to retrieve the waste containers from the disposal site during this operational phase. Measures have to be adopted to enable the waste containers to be retrieved, but without compromising safety.

Rock salt is a mineral (chem. sodium chloride) which in a pure state is colourless, otherwise coloured by pollution. In a refined form it is also referred to as common salt.

Rock transmissivity describes how permeable the subsoil is for certain fluids (e.g. groundwater). If the rock is very permeable, groundwater can flow more easily into the subsoil.