On 25 April 2017, the operator responsibilities for the Asse II mine as well as the Konrad and Morsleben repositories were transferred to the Federal Company for Radioactive Waste Disposal (Bundesgesellschaft für Endlagerung mbH, BGE). This website of the Federal Office for Radiation Protection (BfS) will therefore no longer be updated and displays the status as on 24 April 2017. You will find current information at the BGE: www.bge.de

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Englischsprachiges Glossar

Radar (radio detection and ranging)show / hide

The radar is a device which emits high-frequency electromagnetic fields (usually in the GHz range) and receives and evaluates the echoes thrown back. So objects in the room can be located and their distance can be determined.

Radiation show / hide

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

Radiation exposureshow / hide

Exposure denotes the totality of all environmental impacts (biological, chemical or physical) to which objects 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

  • whole-body exposure, where the whole body is exposed to radiation, and
  • partial-body exposure, where individual organs, tissues or body parts are exposed to radiation.

In the case of external radiation exposure, the radiation source is outside the body.

The term internal radiation exposure is used if radionuclides are incorporated through breathing (inhalation) through food or drinking water (ingestion) or through open wounds and hence represent a radiation source inside the body.

Radiation protectionshow / hide

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

radiation protection areasshow / hide

Spatially separated areas where persons can be exposed to ionising radiation above the limit value for the general national territory.

radioactive contaminationshow / hide

Pollution of work surfaces, devices, rooms, water, air etc. through radioactive substances.

radioactive radiationshow / hide

Radiation is a form of energy moving as electromagnetic wave – or as particle radiation - through space and matter.

Radioactive substancesshow / hide

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 legal excepted quantities 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 limits 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 limits mentioned.

radioactive wasteshow / hide

Radioactive substances as set out in the provisions of § 2 para. 1 AtG which must be methodically removed according to § 9a AtG.

Radioactivityshow / hide

Characteristic of certain atomic nuclei (radionuclides) to convert into other atomic nuclei without extraneous cause, emitting ionising radiation.

Measurand is "activity" i.e. the number of nuclear transformations of a radionuclide or radionuclide mixture occurring per time unit. The measurement is "Becquerel" (Bq), which corresponds to one nuclear transformation per second.

There are both radionuclides occurring in nature and artificial radionuclides produced by nuclear-physical processes. Characteristic for each radionuclide is its half-life.

Radioiodine show / hide

Radioactive iodine isotopes.

Radioisotopesshow / hide

"Radionuclides" with the same atomic number (i.e. same element and same number of protons in the nucleus) are also referred to as isotopes. Example: The two uranium isotopes U-235 and U-236 contain 92 protons each. The number of neutrons however is 143 or 144, respectively.

Radiolysisshow / hide

Modification in a chemical system due to the exposure to ionising radiation.

Radionuclide show / hide

A radionuclide is an instable nuclide which decays into another nuclide spontaneously without extraneous cause emitting energy-rich (ionising) radiation. Currently more than 3,300 different nuclides are known which distribute over 118 currently known elements. Of these nuclides more than 3,000 nuclides are instable and radioactive.

radionuclide inventoryshow / hide

Radionuclides and corresponding activities, e.g. contained in a waste package (unit of waste form and waste container to be disposed of) or in an emplacement chamber.

Radiosynoviorthesisshow / hide

Recovery or regeneration (orthesis) of the synovial membrane (synovial) with the help of irradiation (radatio). A method for the treatment of painful, mostly chronic inflammable arthropaties through local application of radioactive substances. This involves injecting radioactive medicament directly into the diseased joint.

It leads to a sclerosing of the synovial membrane and removes the inflammation process. From this results a considerable abatement of the pains as well as a clear improvement of mobility, in many cases patients are even free of symptoms.

Radiotoxicityshow / hide

The term radiotoxicity describes the adverse effects of incorporated substances (taken up into the body e.g. with food or breathing air) on health due to their radioactive property, as opposed e.g. to the chemical effects ("chemical toxicity"). In terms of a substance's radiotoxicity it is important to what extent the ionising radiation causes bodily harm. This depends on

  • the type and energy of radiation,
  • the incorporation path (path via which the substance enters the body (via food, breathing air, intact skin, open wounds or injection),
  • the organ concentration,
  • the radionuclide's half-life, and
  • the substance's retention period inside the body or, respectively, in the organs.

radonshow / hide

Radon is a noble gas which is colourless, odourless and flavourless, does not bind and escapes via cracks and gaps from the earth into the breathing air. Radon exists only as radioactive isotopes. Radon-222 is the isotope with the longest half-life. It is a natural decay product of the uranium-thorium series which exists all over the earth and contributes considerably to the natural environmental radioactivity. Through further decay further radioactive decay products are generated which enter the lung via the breathing air and emit there, among others, alpha radiation. This can damage the cells of the lung. These damages can favour the generation of cancer.

Radon-222show / hide

Radon-222 is a natural decay product of the uranium-radium series which exists everywhere on earth and significantly contributes to the environmental radioactivity. It is a rare gas which is colourless, odourless, and tasteless, does not combine and escapes from the soil via cracks and gaps into breathable air. Further decay results in radioactive decay products which get into the lung via respiratory ducts, where they emit, among others, alpha radiation. This can damage the lung’s cells. These damages can influence the risk of contracting cancer.

radon monitorshow / hide

Measuring device for determining the radon concentration in the air.

Radon potentialshow / hide

The amount of radon that penetrates into a building from the soil, possibly causing a high radon concentration, does not depend only on the extent to which rock particles in the soil release radon. The mobility of radon or other gases in the soil is also important. The greater this mobility, the greater the soil volume from which radon can penetrate into the building.

This means that, besides the radon concentration in the soil, the gas permeability of the soil must also be assessed in order to make statements about the risk of high radon concentrations in indoor spaces. The radon potential links both measurements into a single, useful assessment parameter.

In Germany, there are regions in which the probability of increased radon concentrations far exceeds the national average, for example

  • the Ore Mountains,
  • the Bavarian Forest,
  • the southern Black Forest,
  • along the northern edge of the Alps and
  • the mountainous upland regions.

To the topic

Rampshow / hide

Accessible, mainly straight-line connection between two levels.

Reaktor-Sicherheitskommission (RSK)show / hide

The "Reaktor-Sicherheitskommission" (RSK) was established by statute in 1958 to advise the BMUB on safety issues related to the generation of nuclear power, nuclear waste management and nuclear fuel fabrication.

The RSK develops recommendations and statements on general and overlapping nuclear safety topics. In additional, the RSK assesses issues raised by BMUB from its supervisory activities including conclusions drawn from incidents at foreign nuclear facilities and their applicability to German facilities.

Since its establishment, the RSK has been engaged in joint discussion of safety issues and exchange on approaches to safety concepts with counterpart organizations from other Countries.

A secretariat established at BfS supports RSK`s advisory work. The web site of the RSK provides information about RSK and its recommendations and statements.

To the topic

Receiving watersshow / hide

Natural (river, stream) or man-made possibility (canal, pumping station) to drain water.

Recruitment show / hide

Conscription, composition

Redox potential show / hide

The redox potential is an electrochemical expression. It is a measure of the tendency to transfer electrons from one chemical species to another. In redox reactions one of the species will be reduced (gains electrons) and the other will be oxidized (loses electrons).

Reference nuclide show / hide

For industrial residues with an elevated amount of natural radionuclides the decay chain generally consists of different specific activities for each nuclide. The radionuclide with the highest specific activity within a decay chain is called the reference nuclide.

Reflection seismicsshow / hide

Geophysical method to determine the depth and position of rock strata through waves artificially produced on the earth’s surface and reflecting from boundaries of underground strata.

Relative risk show / hide

Gives the factor through which the morbidity rate in an exposed group differs from that in a comparison group.

Release show / hide

Administrative act effecting the release of radioactive substances and movable objects, of buildings, surfaces, facilities or facility parts which are activated or contaminated with radioactive substances and which originate from activities according to § 2 para. 1 no. 1 letters a, c or d Atomic Energy Act, from the regulating area a) of the Atomic Energy Act and B) legal ordinances based on this as well as administrative decisions on the use, utilisation, removal, owning or their forwarding to third parties as non-radioactive substances.

Release of radioactive substances show / hide

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

Reportable eventsshow / hide

Events in nuclear facilities or installations fulfilling the reporting criteria of the Ordinance Relating to Nuclear Safety Officers and Reporting according to the Atomic Energy Act (AtSMV) and having to be reported to the competent supervising authorities.

Repositoryshow / hide

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

Reprocessingshow / hide

Combination of physical and chemical separating procedures through which the substances 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).

In the Federal Republic of Germany spent fuel elements were reprocessed for test purposes in a pilot plant from 1971 to 1990 (Karlsruhe reprocessing plant, WAK). Reprocessing operations were discontinued at the end of 1990 and the facility was decommissioned. It is presently being dismantled.

Reprocessing plantshow / hide

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.

Resonance frequencyshow / hide

In the high-frequency field: frequency at which the specific absorption rate (SAR) is the highest, referred to the same occurring high-frequency energy. Resonance frequency results when half of the wave length of the radiation approximately corresponds to the size of the irradiated object.

Retina show / hide

Retina of the eye - optical signals are transformed into nerve signals here.

Retreat workingshow / hide

The emplacement galleries are driven and filled with radioactive waste packages, starting at the back. Then the galleries are sealed.

Retrospective approach show / hide

An investigation approach where for a certain group of persons the exposure or the occurrence of diseases is enquired retrospectively for a certain period of time.

Reviews show / hide

Here: work colloquiums - have been established for the better coordination of the research projects in the fields of biology, dosimetry, epidemiology and risk communication within the scope of the mobile telecommunication research programme.

Risk show / hide

Qualitative and/or quantitative characterisation of a damage as to the possibility of its occurrence (occurrence probability) and the consequences of the damaging effect (extent of damage).

Risk communication show / hide

Interactive process of exchange of information and opinions about risks between scientific experts, risk managers (authorities) and the public (affected persons, stakeholders, etc.).

Risk perception show / hide

Process of subjective perception, processing and evaluation of risk-related information due to personal experience, perceived information and the communication with other individuals.

Risk Ratio/Relative Risk (RR)show / hide

Risk Ratio or Relative Risk: The ratio between the probability to fall ill in an exposed and a non-exposed group of persons who were examined in a cohort study.

  • With an RR of 1 there is no difference between the two groups.
  • With RR less than 1 the risk is lower in the exposed group, with RR higher than1 higher than in the non-exposed group.

By means of significance test it can be investigated how statistically significant this difference is.


Road headershow / hide

Tunneling machine for the driving of mine openings, working the working face in sections.

roadside packshow / hide

Construction, such as a wall, to tell apart cavities to be backfilled from mine openings to be kept open.

Rock-boltingshow / hide

Prefabricated rods made of steel or fibreglass-plastic which are placed into bore holes and fixed. They serve to hold rock layers together.

Rock mechanicsshow / hide

Science of mechanical behaviour of the rock in case of tectonic/technical force effects or deformations.

Rock salt show / hide

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

rock salt barriershow / hide

Salt rock between mine and water-bearing (aquiferous) overburden.

Roof show / hide

The mining term "roof" refers to a rock layer superposing a reference layer (rock underlying this).

Roof boltshow / hide

A roof bolt is a steel bar connecting rock layers to increase stability.

roof bolting worksshow / hide

Routine security works underground. Loosened (salt) surfaces are closely reconnected with the rock e.g. through a kind of nail = “roof bolt” and wire mesh.

roof cleftsshow / hide

Cavities on the roof level forming through settling processes of the backfill material when cavities have been backfilled with loose salt.

roof milling toolshow / hide

Vehicle used in the mine for removing loosened rock (= scaling works).

Room-and-pillar systemshow / hide

Mining method with constructions like chambers.

Round containersshow / hide

Waste packages in the form of a drum.

runsshow / hide

Ladders used in underground operation, e.g. in bore holes.

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