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

Damage show / hide

Negatively evaluated result of an event or an action.

Danger show / hide

Process, circumstance or state of which with sufficient probability a damage can result to man, the environment or other assets to be protected.

Daughter radionuclideshow / hide

The nuclide generating during radioactive decay. It can be radioactive itself; it will then have its own characteristic radiation and half-life.

Debrisshow / hide

Rock removed from the structure of rock mass.

Debris, excavated material show / hide

Mineral or rock unhinged from the rock mass, consuming more space when loose than before.

Decay heat show / hide

Heat in a nuclear reactor produced after the reactor has been shut down, due to the decay of radioactive fission products. In the first seconds following a shut-down, the decay heat is still about 5 per cent of the output before shut-down.

Decommissioning show / hide

All measures following the final shut-down of a nuclear facility with the objective of the facility's safe enclosure or dismantling

Decontamination show / hide

Removal or reduction of radioactive contamination.

Demodulation show / hide

Retrieval of a signal-carrying information from a combination of carrier and signal frequencies generated through modulation (here: the mobile telecommunication signal).

Demography show / hide

Demography (Greek demos = people, graphein = write) is a science investigating the state and the development of the population on a statistical level. Demographic features are (objective) characteristics of persons of a social and economic kind, such as e. g. gender, age, profession, income, education, household size, social affiliation, religious affiliation, place of residence, size of the place of residence.

Densely-ionising / highLET show / hide

Densely-ionising or loosely-ionising radiation, respectively, differ from each other in the spatial distance of the ionisation processes. These are in the case of densely-ionising radiation (alpha radiation, neutrons) considerably narrower than in the case of loosely-ionising radiation (gamma radiation, X-radiation, beta radiation). A different biological effectiveness is associated with this different ionisation density.

Denudationshow / hide

Extensive ablation of the earth’s surface, e.g. by water or wind.

Depositshow / hide

Enrichment areas of mineral raw materials in the earth’s crust.

Depth show / hide

The mining term depth refers to the depth below earth surface.

designshow / hide

Implementation of safety-related requirements; if these requirements are complied with, the necessary state-of-the-art of science and technology precaution against damages resulting from the construction and operation of a nuclear facility has been taken (§ 7 para. 2 no. 3 AtG) in order to achieve the protection goals set out in concrete terms in the Atomic Energy Act, in the Radiation Protection Ordinance, and in 50 safety criteria and directives.

Design earthquakeshow / hide

Earthquake of the greatest possible intensity for the site that occurred in the past, taking into account the immediate vicinity of the site.

design-exceeding eventshow / hide

Design-exceeding courses of events are such processes that may develop from system or component failures which can no more be taken into account in the design of the nuclear facility. Within the scope of the fulfilling the regulations set out in § 3 of the Ordinance Concerning Procedures According to Atomic Energy Act (AtVfV), a statement of the provisions to be taken for compliance with § 7 para. 2 no. 3 AtG is required including an elaboration of the measures and tasks to exclude or restrict consequences of design-exceeding courses of events. These measures are described in the emergency manual.

Design incidentshow / hide

Incident in accordance with § 49 of the Radiation Protection Ordinance.

Deterministic radiation damageshow / hide

Deterministic radiation damage has a threshold dose value below which the effect does not occur. If the threshold dose is exceeded, the severity of the effect increases with increasing dose. Examples for deterministic effects are skin erythema and epilation.

Diagenesisshow / hide

Solidification of loose sediments to solid rocks, e.g. sand to sandstone.

Dialogue show / hide

Two-way communication between two parties.

Diapirismshow / hide

Rock masses penetrating the overlapping layers; this refers in particular to rock salt, given its higher plasticity and low density.

Diffusorshow / hide

Funnel-shaped pipe serving to gradually delay the flow velocity of the exhaust air, in order to prevent it from swirling and thus to prevent flow losses.

Digital subtraction angiography show / hide

X-ray representation of blood vessels by means of injections of contrast agents. A better representation of the blood vessels is achieved by the electronic subtraction of the plain radiograph prior to the contrast radiograph with simultaneous reduction of contrast agent.

Dipping technique show / hide

The dipping technique is used as an alternative to the stacking method when the waste packages slide or fall into a deeper emplacement cavity. The dipping technique may be preferred on the basis of the spatial conditions, however, it is sometimes also applied for radiation protection reasons.

Dip workingshow / hide

Mine opening below the lowest heading level connected to a shaft.

Discharge airshow / hide

Discharge of used air and harmful gases.

Discharge of radioactive substances show / hide

Discharge of liquid, aerosol bound and gaseous radioactive substances from facilities and installations via the intended pathways.

Discourse show / hide

Forums of communication oriented towards understanding, where in view of a joint gaining of findings or decision-making, arguments are investigated according to determined rules regarding their claim of importance and without credit to the person and his/her status.

Disposal show / hide

Disposal is the safe, temporally sufficient isolation of harmful substances from the biosphere. Within the scope of disposal of radioactive waste the radioactive substances have to be kept away from the "biosphere" by a multi-barrier system. The required time frame to be observed results from the "half-lives" of the waste to be disposed of and the resulting potential danger.

Disruptive factors show / hide

In epidemiological studies, in addition to the investigated exposure, other factors can influence the result. These must be taken into account when evaluating the data.

DNA show / hide

Deoxyribonucleic acid is a biomolecule occurring in all living organisms. It is the carrier of genetic information.

Documentationshow / hide

Systematic compilation of documents.

Dose show / hide

Dose is a measure for radiation effects. See also absorbed dose, organ dose, effective dose.


Dose equivalentshow / hide

Product of absorbed dose at a point in ICRU-soft tissue and the quality factor Q, considering the relative biological effectiveness of different types of radiation. The dose equivalent is the measured quantity for biological effects of ionising radiation on man. Its unit is J/kg with the special name Sievert (Sv). 1 µSv = Microsievert is the millionth part of Sievert. 1 mSv = Millisievert is the thousandth part of Sievert.

Dose rateshow / hide

Quotient of dose and time.

Dose rate measurementshow / hide

Measuring the absorption of radiation by matter or the human body per kilogramme per unit of time.

Dose-response relationship show / hide

In general, this is the functional relationship between the size of dose of a substance and the extent of the response to it. For example, with a linear dose-response relationship the dose and response are always in the same proportion, that is half the dose yields half the response, one tenth of dose yields one tenth of response et cetera. A linear dose-response relationship would mean, for example, that one per cent of radiation dose will cause one per cent of cases. However, it is quite possible that there is a threshold of dose below which body cells are able to repair radiation injuries except for extremely few mistakes. There would be practically no case that could occur below this dose threshold (threshold value).

dosimetershow / hide

dosimeter: Personal dosimeter; a measuring device to determine the individual radiation exposure due to ionising radiation or electromagnetic fields.

Dosimetry (non-ionising radiation) show / hide

Quantitative registration of exposure due to electromagnetic fields.

Double blind test show / hide

Execution of a test where both the test person and the attending personnel do not know if there is an exposure or not. This is to ensure that influencing by mental factors is excluded.

draw offshow / hide

Remove installations and supports from a decommissioned mine.

drilling jumboshow / hide

Machine used for producing bore holes.

driveshow / hide

Production of a horizontal or inclined gallery or another mine opening.

Drying plantshow / hide

Plant to dry delivery vehicles.

ductshow / hide

Tube, e.g. for transporting air.

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