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Home > Glossary


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Ampere, measuring unit of electrical amperage

Absorbed dose
see “Dose”

Weakening of the intensity of a particle or a beam when passing matter. The energy of the irradiation is transformed into another form of energy (e. g. heat). The energy absorbed by biological tissues is the basis for the calculation of the dose absorbed by the organism.

Sequence of events which may result in an effective dose of more than 50 mSv for one or more persons.

Actinic keratodermas
Actinic or solar keratodermas are also referred to as sun calluses. They are disturbed hornifications of the skin caused by solar radiation (corneous or wart-like reddish-brown proliferations). They occur mostly from the age of 50 on and are particularly at places which had been exposed to solar radiation for decades.

Mainly fair-skinned persons with skin types I or II who get sunburn easily are affected by this. In dark-skinned persons actinic keratodermas are very rare. Besides men get them more frequently than women do. Actinic keratodermas occur more frequently in persons who as a result of their occupation often stay in the open. Actinic keratodermas are pre-stages of the spinalioma.

Activity concentration
Rate of activity of a radionuclide to the volume of the material in which the radionuclide is distributed.

Activity concentration of the air
The activity concentration of the air is given in the unit Becquerel per cubic metre (Bq/m³). The activity concentration of the air states which activity of a certain radionuclide is included in one cubic metre air.

Activity is the number of nuclear transformations occurring per time unit in a radioactive substance. The measuring unit of activity is Becquerel (short symbol: Bq) with which the number of radioactive nuclear transformations per second is given. As the radionuclides can be included in amounts of substance of different configuration, the activity is frequently also referred to them, e. g. Becquerel per gram (Bq/g) in solid substances, Becquerel per litre (Bq/l) in liquids or Becquerel per cubic metre (Bq/m³) in air. Solely stating the activity without knowing the radionuclides does not allow a statement on the radiation exposure.

Activity, specific
Rate of activity of a radionuclide to the mass of the material in which the radionuclide is distributed. In the case of solid radioactive substances the reference mass for the determination of the specific activity is the mass of the body or object to which the radioactivity is inseparably connected in an intended application. In the case of gaseous radioactive substances the reference mass is the mass of the gas or gas mixture.

Solid or liquid components of air (diameter: 10-3 to 10-8 cm). The major part of the natural and artificial radionuclides of the air is bound to aerosols.

There has been no repository for spent fuel elements from nuclear power plants and for high-radioactive waste from reprocessing world-wide. In Germany, the Gorleben salt dome was investigated since 1978 for its suitability as a repository for all types of radioactive waste. The Federal Government, however, doubts the Gorleben site's suitability. In consultation with the utilities it therefore interrupted the investigation on 1st October 2000 for a period of three to maximum ten years in order to clarify conceptual and safety-related questions (moratorium).

The federation does not see any alternative to disposal in deep geological formations for the long-term safe disposal of radioactive waste. Therefore the Federal Government will search further sites in different rock formations for disposal and investigate them for their suitability.

The question results how sites can be identified which are suitable for a safe disposal and are at the same time accepted by the general public.

Against this background the Federal Ministry for the Environment, Nature Conservation and Nuclear Safety (BMU) established the Working Group for the Selection of Repository Sites (AkEnd) in February 1999. The recommendations of the AkEnd serve to support the federation in the execution of its tasks to erect facilities for the disposal of radioactive waste according to § 9a para. 3 Atomic Energy Act (AtG).

The AkEnd is a scientific body working independently and free of directions and orders within the scope of the objectives aimed at. When appointing persons for the AkEnd, BMU observed a fair balance regarding persons and institutions, so that a wide spectrum of opinions on the issue of disposal existing among experts is represented.

The members of AkEnd are experts in the fields of geosciences, social sciences, chemistry, physics, mathematics, mining, disposal technology, engineering, and public relations.

The AkEnd has the task to develop a comprehensible procedure for searching and selecting sites for the disposal of all types of radioactive waste in Germany. The procedure should in an appropriate form provide for involvement of the public and include well-founded criteria. The development should be made on a scientific basis in a way that is oriented towards facts, unprejudiced and without excluding relevant aspects, taking into account the procedures and experiences made in other countries. The AkEnd should discuss its considerations already in the process of their development with national and international experts and the interested public.

AKR mice
A special inbreeding clade showing a high spontaneous leukaemia rate. It is an acknowledged animal model for human leukaemias used in cancer research.

Abbreviation of "as low as reasonably achievable". Principle of radiation protection in the case of ionising radiation according to which all reasonable and sensible measures must be taken to keep radiation exposure to man as low as possible, even below the limits.

Alpha radiation, alpha particles
Particle radiation in the form of alpha particles. Positive-charged particle emitted in the nuclear disintegration of certain radionuclides. It consists of two neutrons and two protons and is identical with the nucleus of the helium atom. Alpha particles are already absorbed by a few centimetres of air and can neither penetrate a sheet of paper nor human skin. Alpha particles can only have effects on the organism if the substance emitting alpha radiation is inhaled or ingested or enters the body via open wounds. Generally, alpha disintegration is accompanied by gamma radiation – cf. beta radiation, gamma radiation.

Amplitude modulation

Ambient dose equivalent H*(10)
Dose equivalent at a point in a radiation field, that would be produced by the corresponding expanded and aligned field in the ICRU sphere at a depth of 10 mm on the radius vector opposing the direction of the aligned field. The unit of H*(10) is J/kg with the special name Sievert (Sv).

Ambient dose rate
Ambient dose equivalent per time interval.

Arzneimittelgesetz, Medical Preparations Act

Maximum move of a vibration or a wave

Doctrine of the blood and lymphatic vessels; one of the emphases of internal medicine

Influenced, caused by man

Atomgesetz, Atomic Energy Act

Athermal effects
A number of different effects under exposure to high-frequency electromagnetic fields occurring independently of a heating of the tissue.

An atom is the smallest particle of an element and chemically not separable. An atom consists of a very dense nucleus and an atomic shell. The main mass of the atom is concentrated in the nucleus in the form of protons (electrically positively charged particles) and neutrons (electrically neutral elementary particles). The atomic shell consists of negatively charged electrons orbiting the nucleus. Atoms are electrically neutral as the number of protons in the nucleus and the number of electrons in the shell is identical.

A component of a safety-related system is available, if it is ready in all cases of required operation it has been designed for, e.g. to control design basis accidents, to prevent impermissible plant conditions or impermissible loads of components and systems, and if its functionality has been demonstrated by periodic inspections (cf. definition "periodic inspections").

Non-availabilites of components or systems, which are induced temporarily and in a planned manner by procedures as specified in the operating manual, are not reportable if this is also considered in the safety specification of the operating manual.

Allgemeine Verwaltungsvorschrift, General Administrative Provisions

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Symbol of magnetic flux density

Backfill is both the procedure and the material (filling material) for the backfilling of the still existing cavities or residual cavities during the final sealing phase in the post-closure phase of a repository mine.

Bundesanstalt für Milchforschung, Federal Dairy Research Centre

Barriers, radiological
The radioactive inventory of a nuclear facility is safely enclosed with the help of the multi-barrier system, i. e. in order to be released, radioactive substances have to pass several different barriers one after the other. The radiological barriers of a nuclear reactor consist of: 1. the retention of the fission products in the nuclear fuel itself, 2. the enclosure of the nuclear fuel in hull pipes, 3. the enclosure of the fuel elements in the reactor pressure vessel, and 4. the gas-tight containment around the reactor pressure vessel.

Bundesanstalt für Arbeitsschutz und Arbeitsmedizin, Federal Office for Safety at Work and Occupational Medicine

Bundesanstalt für den Digitalfunk der Behörden und Organisationen mit Sicherheitsaufgaben, Federal Agency for Digital Radio of Security Authorities and Organisations

Becquerel (Bq)
The Becquerel (short form: Bq) is the measuring unit of the "activity" of a radioactive substance and indicates how many nuclear disintegrations per second occur.

Bed separators
Bed separators are pieces of rock separating from the roof of a mine opening which may fall down or have already fallen down.

Verordnung über das Nachweisverfahren zur Begrenzung elektromagnetischer Felder, Ordinance Relating to the Detection Procedure to limit electromagnetic fields

BEMS (Bioelectromagnetic Society)
The BEMS was founded in 1978 as an organisation of scientists of the fields of biology, physics, medicine and engineering, who are interested in the interactions of electromagnetic fields with biological systems. The BEMS is an international organisation consisting currently of about 626 persons from 38 countries. It publishes the scientific professional journal "Bioelectromagnetics".

Beta radiation
Particle radiation consisting of electrons which are emitted by atomic nuclei during radioactive decay. The energy distribution of the beta particles is continuous (beta spectrum) and has a sharp upper limit (so-called end energy).

Beta radiation, beta particles
Particle radiation in the form of electrons (beta particles). Electron with positive or negative charge which is emitted by an atomic nucleus or elementary particle during beta decay. The penetration capacity of beta particles is some centimetres to metres in air, in soft part tissue or plastic some millimetres to centimetres. Generally beta decay is accompanied by the emission of gamma radiation – cf. alpha radiation, gamma radiation.

Beta submersion
Radiation exposure through beta radiation of radioactive substances in the atmosphere.

Bundesforschungsanstalt für Fischerei, Federal Research Centre for Fisheries

Bundesinstitut für Arzneimittel und Medizinprodukte, Federal Institute for Drugs and Medical Devices

Bundesforschungsanstalt für Ernährung, Federal Research Centre for Nutrition

Bundesanstalt für Gewässerkunde, Federal Institute of Hydrology

Bundesamt für Strahlenschutz, Federal Office for Radiation Protection

Bundesgesetzblatt, Federal Law Gazette

Bundesanstalt für Geowissenschaften und Rohstoffe, Federal Institute for Geosciences and Natural Resources

Biological effects
Influences on living material (organisms, tissues, cells)

Totality of the part of the earth which is filled with life

Verordnungen zur Durchführung des Bundes-Immissionsschutzgesetzes, Ordinances Relating to the Implementation of the Federal Immission Protection Act

Blood-brain barrier
The blood-brain barrier is a selectively permeable barrier between blood and cerebral matter. It actively controls the substance exchange between blood and central nervous system. It keeps away damaging substances from the neurons. The blood-brain barrier is formed by the inner cell layer of the small blood vessels in the brain (capillary endothelial cells and the surrounding auxiliary cells, the astrocytes.

British Nuclear Fuels Ltd., former State-owned enterprise in the UK, operated among others the reprocessing plant in Sellafield. BNFL have ceased their activities since May 2009.

Body dose
Collective term (used in Germany) for equivalent dose and effective dose. The body dose for a reference period (e. g. calendar year, month) is the sum of the dose received by external radiation exposure during this reference period and the committed dose received by internal radiation exposure which is due to an activity intake during this reference period. The unit of the body dose is J/kg with the special name Sievert (Sv).

Behörden und Organisationen mit Sicherheitsaufgaben, Security Authorities and Organisations

Treatment of diseases through radiation sources brought into the body or put onto the body, respectively.

Bronchial carcinoma
Cancer of the bronchi, lung cancer

Bundesamt für Seeschifffahrt und Hydrographie, Federal Office for Maritime Shipping and Hydrography

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Instable isotope of caesium; physical half-life ca. 30.2 years.

Cap rock
Rock generating above salt rocks when in contact with (salt) unsaturated water. When salt ascends in the course of salt dome generation it can reach and enter groundwater-bearing layers. If it gets into contact with groundwater, the salt components are dissolved. What remains are the water-insoluble components, in particular gypsum. They form the cap rock above the top of salt dome (uppermost, mostly horizontal boundary surface of a salt dome).

is the property of substances to cause cancer (malignant tumours).

Section of internal medicine or pediatrics dealing with the diseases and changes of the heart and their treatment

Case-control study
In a case-control study it is investigated if persons with a certain disease (so-called cases) have been exposed more or less frequently than comparable persons without this disease (so-called controls).

Case-control studies, nested
Frequently a certain disease is examined in more detail within the scope of a cohort study. All persons with this disease (so-called cases) are selected from the cohort as well as an accidental part of persons from the cohort without this disease (so-called controls) are selected. Subsequently further interrogations or polls are carried out for this subgroup. This type of study is referred to as nested case-control study since the case-control study is nested into a cohort study.

Dullness of the eye lense.

Causal correlation

Cavitation, acoustic
Acoustic cavitation is the sound-induced formation and the mechanic activity of cavities and vapour locks. Cavitation only occurs when a certain threshold value of the negative peak pressure is exceeded and can then trigger off a wide spectrum of physical, chemical and biological effects in the tissue. Acoustic cavitation consists of transient and stable cavitation. Transient cavitation is a short-term expansion of existing vapour locks to larger cavities during the subpressure phase of a sound wave with subsequent collapse in the following pressure phase. Stable cavitation is the resonance vibration of existing vapour locks in the exposed material over a longer period of time without collapse.

Strongly inclined or vertical mine opening of low square or round cross-cut for the downwards haulage of material which rolls down due to gravity. Chutes can also be used for ventilation and man haulage.

Clearance measurements
Clearance measurements are made of radioactive waste when its "radioactivity" is so low that it can be assigned to other waste types and can then be treated or deposited correspondingly. Clearance measurements can possibly require a previous interim storage period, so that waste with short "half-lives" can loose its activity during interim storage – also referred to as decay time.

Part of the inner ear; acoustic signals (tones) are converted into nerve signals.

Compagnie Générale des Matières Nucléaires, today AREVA NC, French group of companies for nuclear fuel supply and waste management; operates among others the reprocessing plant in La Hague.

Cohort study
An investigation in which a group of persons (cohort) with known exposure conditions are observed over a longer period of time and the various exposures are associated with the occurrence of diseases.

Computer tomography (CT)
X-ray examination with relatively high radiation exposure but very high diagnostic significance due to the fact that it is represented as cross-sectional image which is free of overshadowing

Conditioning is the treatment and packaging of radioactive waste suitable for interim storage and/or disposal. The most important sections of conditioning are the solidification of liquid waste and packaging suitable for handling, taking into account the necessary radiation protection for the personnel in the interim storage facilities and repositories who have to handle the waste later on.

Within the scope of risk communication "confidence" means "to be able to rely" on the availability of competence (knowledge, ability), ensuring of fairness (openness, equality of opportunity) and the performance of social responsibility (e. g. to personnel, clients, neighbours, general public).

Such a variable "disturbs" the correlation between influencing variable and event investigated in a study, i. e. cause of disease or death. A disease investigated in correlation with ionising radiation is generally not only caused by radiation but also by other influencing parameters. Taking such confounders into consideration is therefore an essential point in the planning and carrying out of an epidemiological study. If this is not done, a correlation that does not exist in reality can be pretended or an existing correlation can be blurred. If the influence of such additional factors that have not been taken into consideration pretends a correlation that does not exist in reality, this is referred to as "positive confounding", but if it overlaps the real correlation, this is referred to as "negative confounding". Frequently a narrow correlation between the disease frequency and the influencing variable is suggested which does not exist in reality since both are connected with a joint third variable.

Falsification of risk assessment through confounders that have not been taken into consideration, which correlate with both the disease and the risk factor investigated.

Pollution of work spaces, devices, rooms, water, air etc. due to radioactive substances.

  • Surface contamination:
    Pollution of a surface with radioactive substances, comprising non-adhesive, adhesive activity and that having entered via the surface. The unit of the measuring quantity of surface contamination is the surface-related activity in Becquerel per square centimetre.
  • Surface contamination, non-adhesive:
    Pollution of a surface with radioactive substances, where a further distribution of the radioactive substances cannot be excluded.


Control group
A group of cells, animals or test persons being exposed to the best possible identical conditions as the exposed individuals, with the exception that the effect to be investigated is not administered.

Natural process of volume reduction of underground cavities as a result of deformation or loosening due to rock pressure.

Cooling pond
Pond filled with water, where fuel elements – after having been used in the reactor – are stored until activity and heat generation have reduced to the desired level.

Cosmic radiation
Natural process of volume reduction of underground cavities as a result of deformation or loosening due to rock pressure.

COST 281
COST is short for "European Cooperation in the Field of Scientific and Technical Research". COST does not support single research projects but the coordination of international research. COST 281 refers to a subgroup focussing on telecommunication. The main objective is the improvement of the information situation on possible health effects of new communication and information technologies associated with the exposure to electromagnetic fields. Presently 23 European countries participate in this campaign.

The state of a nuclear reactor where a self-perpetuating chain reaction is taking place. Undercriticality is the state where no chain reaction can be sustained.

Comprehensive Nuclear-Test-Ban Treaty Organization

Cytogenetics deals with the representation and analysis of chromosomes. Chromosomes are carriers of the dispositions and can be represented in the light-optical microscope. They are in the cell nucleus.

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Negatively evaluated result of an event or an action.

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

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

Decay heat
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% of the output before shut-down.

Decimal places
Decimal places – how to convert:
Multiple Combining form mark
103 = 1 000 Thousand k = Kilo
106 = 1 000 000 Million M = Mega
109 = 1 000 000 000 Milliard (br.), billion (am.) G = Giga
Fractional amount Combining form mark
10-3 = 0,001 1 thousandth m = Milli
10-6 = 0,000 001 1 millionth µ = Mikro
10-9 = 0,000 000 001 1 millardth, 1 billionth n = Nano


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

Removal or reduction of radioactive contamination

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

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
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.

The mining term depth refers to the depth below earth surface

Deterministic radiation damages are characterised by the fact that the level of damage increases with dose and that there is generally a threshold value, e. g. erythema, dullness of the eye lense.

Two-way communication between two parties

Digital subtraction angiography
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
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.

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

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 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
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.

Deutsches Krebsforschungszentrum, German Cancer Research Centre

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

Dose is a measure for radiation effects.

  • Absorbed dose:
    Absorbed dose is the energy imparted by ionising radiation to a volume element of any matter with a certain mass, divided by this mass. The unit of the absorbed dose is J/kg with the special name Gray (short form: Gy).
  • Organ dose:
    Mean absorbed dose in an organ or tissue. The unit of the organ dose is J/kg with the special name Gray (Gy).
  • Equivalent dose:
    Equivalent dose considers the relative biological effectiveness of different types of ionising radiation. The equivalent dose is the product of the mean absorbed dose in a tissue or organ and the radiation weighting factor. If several types of radiation are involved the total equivalent dose is the sum of the respective components. The unit of the equivalent dose is J/kg with the special name Sievert (Sv).
  • Effective dose:
    TEffective dose considers the different sensitivity of organs and tissues forstochastic radiation effects. For this purpose the equivalent doses are weighted by tissue weighting factors. The weighting factors represent the relative contributions of the single organs and tissues to the total health detriment resulting from uniform irradiation of the whole body.The effective dose is sum of the the tissue-weighted equivalent doses in all specified organs and tissues of the body. It is weighted such that the sum of the tissue weighting factors is unity. The unit of effective dose is J/kg with the special name Sievert (Sv).
    In radiation protection practice usually fractions of the unit dose are used, e. g. Millisievert (mSv), Microsievert (µSv).


Dose equivalent
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-response relationship
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).

Dosimeter (non-ionising radiation)
Here: personal dosimeter; a measuring instrument to determine the individual radiation exposure due to electromagnetic fields.

Dosimetry (non-ionising radiation)
Quantitative registration of exposure due to electromagnetic fields.

Double blind test
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.

Deutscher Wetterdienst, German Meteorologial Service

Pressurised water reactor. Power reactor where the heat is discharged from inside the reactor (so-called reactor core) via water which is under high pressure (about 160 bar). Thus boiling is avoided inside the reactor core and simultaneously a high water temperature is achieved in the reactor circuit (so-called primary coolant circuit). The coolant of the primary coolant circuit gives off its heat in a steam generator to the water of the secondary coolant circuit. The steam generated in this way drives the turbine and the generator to generate electrical current.

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Symbol of electric field strength

Eddy current
Electric current generated by induction in a conductible body.

Electroencephalogram; a method to measure cerebral currents.

Effective dose
see “Dose”

equivalent isotropic radiated power
EIRP characterizes the properties of a transmitter; it is based on the transmitter power and the antenna gain. It indicates the total power that would be needed for a (hypothetical) isotropic antenna if it were to produce the same power density as a beam antenna.

Electric charge
Feature of bodies consisting in the existence of a weight between the charged bodies. At random one distinguishes between positive and negative electric charges. Charges with the same sign repel mutually, those with unequal signs attract each other. The measure is Coulomb (C).

Electric current
The electric charge flowing through the cross-section of a conductor, referring to time. The measure is Volt (V).

Electric field
see field

Electric field strength
Measure for the strength and direction of an electric field. The measure is Volt per meter (V/m).

Elementary particle with a negative electric elementary charge. Electrons orbit the positively charged atomic nucleus. Their number determines the chemical behaviour of the atom.

Special sensibility to low- and high-frequency electromagnetic waves; affected persons perceive e. g. electric currents clearly at lower intensities than the average population.

Description of a subjectively perceived special sensitivity to low- and high-frequency electromagnetic fields. Electromagnetic fields are considered to be the cause of various unspecific symptoms such as headaches, rheumatic pains, insomnia, dizziness, lack of concentration or listlessness. No scientific proof for a causal correlation between the health complaints and the effects of low-frequency or high-frequency electromagnetic fields could be established yet.

Electrostatic field
Temporally unchanged electric field (cf. Field)

Embedded case-control study
In a cohort study it may be necessary to use additional information for a certain problem which is not available to all of the cohort or which cannot be gathered for all members of the cohort for economical reasons. In this case "cases" and controls are selected from the cohort, for which then – embedded in the cohort-study – further data is collected within the scope of a case-control study, e. g. by interrogations.

Environmental Impact Assessment (EIA) (Umweltverträglichkeitsprüfung, UVP)
Within the scope of the "plan-approval (licensing) procedure" the EIA comprises the identification, description and evaluation of the effects of a project on man, animals, plants, soil, water, air , climate and landscape, including the respective interactions and on cultural assets and real assets.

Sector of science dealing with the distribution of transferable and non-transferable diseases and their physical, chemical, mental and social determinants and consequences in the population.

Epidemiological investigations
Epidemiology deals with the investigation of disease distribution in the population and with the risk factors on which this distribution is based. The most frequent study types to investigate the correlation between diseases and risk factors on which they are based are case-control studies, cross-sectional studies and cohort studies.

European Union

European Atomic Energy Community

Exemption levels
Values of activity and specific activity of radioactive substances according to Annex III Table 1 Columns 2 and 3 Radiation Protection Ordinance. When these values are exceeded, activities with these radioactive substances are subject to monitoring under this ordinance.

Exposure pathway
Pathway of radioactive substances, starting from the discharge from a facility or installation via a dispersion or transport process to radiation exposure of man

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Symbol of frequency

Totality of features of a sediment rock such as petrologic structure or fossil content.

Radioactive material from the atmosphere having reached the earth in the form of smallest particles and deposited through precipitation and sedimentation of aerosols, having for instance originated in nuclear tests.

Food and Agriculture Organisation of the United Nations

Far field
From a certain distance to a radiation source on, the electromagnetic field is termed far field. In the far field the electric and magnetic field are closely coupled to each other and can be converted into each other using a constant factor.

Feasibility study
In a feasibility study it is investigated if and under which conditions a planned elaborate investigation can be successful.

Federal Network Agency

Federal Network Agency for Electricity, Gas, Telecommunications, Post and Railways. In July 2005 the regulatory authority for telecommunications and post (RegTP) was renamed to „Federal Network Agency for Electricity, Gas, Telecommunications, Post and Railways“. At the samt time its scope of duties was extended.

The tasks in the area of telecommunications include e. g. the granting of site certific-ates for mobile phone base stations on the basis of the Ordinance concerning the Controls for the Limitation of Electromagnetic Fields (BEMFV). The Federal Network Agency carries out test series to control compliance with limit values as well as, in individual cases, controls of stationary amateur radio installations. Data of the site certificates of mobile phone base stations can be found in the EMF data base.

Federal order
The Laender execute federal laws by order of the Federal Government (Bundesauftragsverwaltung, federal executive administration). When judging and deciding a situation differently, the Federal Government can give a federal order to the Land relating to the decision. The responsibility for the decision made according to the order is then with the Federal Government.

Federal state collecting depot
Federal state (or Laender) collecting depots are the interim storage facilities of the Laender erected for the waste produced in the areas of medicine, technology and research. Federal state collecting depots do not accept waste produced in connection with energy supply and reprocessing.

Sexual reproduction

Fischereiforschungsschiff, Fisheries Research Vessel

State of space in which each space point can be assigned to the value of a physical quantity, e. g. electric or magnetic field strength.

  • Electric field:
    Force field forming between electrically charged bodies. According to the size of its electric charge a force acts on a body in the electric field. The measure for strength and direction of this force is the electric field strength E given in Volt per metre (V/m).
  • Magnetic field:
    Force field caused among others by moved electric charges. Magnetic fields occur in the vicinity of conductors flown through by current and permanent magnets. In the case of permanent magnets fluxes inside the atom of the moving electrons are the cause of the magnetic field. The magnetic field strength H marks strength and direction of the magnetic field, its measure is Ampere per metre (A/m). Besides the magnetic field strength also the magnetic flux density B describes the strength of the magnetic field, the measure is Tesla (T). 1 T = 1 Vs/m², the measure Microtesla (µT) is common. The following applies to the conversion of magnetic flux density into magnetic field intensity in the air or in biological tissue: 1 µT corresponds to 0.8 A/m.
  • Electromagnetic field:
    One talks about an electromagnetic field if temporally changeable electric and magnetic fields are non-detachably connected with each other at high frequencies.


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

Feuchtmasse, wet weight

In the follow-up one determines for each person of the cohort study whether they have fallen ill by an appointed date (incidence follow-up) or if they have died (mortality follow-up). For the incidence follow-up one enquires at the cancer register of the former GDR for all persons of the cohort study if they have at any time suffered from cancer. For dead persons one enquires the cause and date of death at the health authorities.

Number of oscillations in a time unit; the measure of frequency is Hertz (Hz): 1 Hz = 1 oscillation per second = 1/s. Frequency and wave length are connected to each other. The wave length is the distance of neighbouring oscillation states of the same phase in the direction of propagation, e. g. between two wave crests following upon each other.

Fuel element
Arrangement in which a multitude of fuel rods has been combined to form a construction unit with which the nuclear fuel is brought into the reactor.

Fuel rod
Geometrical shape in which nuclear fuel, coated with hull material, is brought into a reactor. Mostly several fuel rods are combined to form a fuel element (Brennelement, BE). In the case of the Krümmel nuclear power plant with a boiling water reactor 72 fuel rods form a fuel element, in the case of the pressurised water reactor of the Emsland nuclear power plant 300 fuel rods have been combined to form one fuel element.

Forschungszentrum, Research centre

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A gallery is a horizontal or nearly horizontal mine opening for material transport, men-haulage and ventilation, which is long in proportion to the cross-cut.

Gamma dose rate
The gamma dose rate is the radiation exposure which effects man from outside. It is given as dose equivalent, measured at a certain place per hour. The gamma dose rate is generally given in Microsievert per hour (µSv/h).

Gamma radiation
Electromagnetic wave radiation emitted by an atomic nucleus. Gamma radiation of the same physical nature as visible light, however with considerably more energy and high penetration capacity in matter. Heavy materials such as lead or concrete must therefore be used for shielding from gamma radiation. Apart from the type of generation gamma radiation can be compared to X-radiation – cf. alpha radiation, beta radiation.

Gamma submersion
Radiation exposure through gamma radiation of radioactive aerosols and gases in the atmosphere.

Special area of internal medicine dealing with the diseases of the gastro-intestinal tract and adjacent organs.

Geosphere is the space where the earth's crust, water and air hull touch and penetrate each other.

A measure usual in geodesics of the even angle, defined as the hundredth part of the right angle ( 1 Gon = 0,9°).

SI-measure of the energy dose, 1 Gray (Gy) = 1 joule per kilogram

Former Forschungszentrum für Umwelt und Gesundheit, Research Centre for Environment and Health, today Helmholtz Zentrum München- German Research Center for Environmental Health (HMGU)

Global System for Mobile Communications. International standard for mobile communications operations. The transmission frequencies are at 900 MHz (e. g. D-network) and 1800 MHz (e. g. E-network). The data transmission rate is 9.6 kbit/s. The signal is pulsed with 217 Hz.

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Symbol of the magnetic field

Time interval in which half of the nuclei of a radioactive nuclide have decayed. Short half-lives lead to a high radiation activity and long half-lives lead have a low radiation activity. The biological half-life is the time in which a biological system, e. g. a human being or an animal, excretes in a natural way half of the amount of a certain substance taken up from the body or a certain organ. The effective half-life is the time in which in a biological system the amount of a radionuclide reduces by half, namely in coaction of radioactive decay and excretion as a result of natural processes.

Healthy Worker Effect
In epidemiological cohort studies a low frequency of falling ill often occurs in occupationally exposed groups of persons, compared to non-exposed persons of the general population, as for some professions a certain health constitution is a prerequisite. Not employed persons are usually "more ill" than employed persons. A reduced risk of falling ill based on the unilateral selection of healthier occupationally exposed persons is referred to as Healthy Worker Effect.

Abbreviation of the term "High-frequency"

High-frequency electromagnetic fields. Here defined as frequencies between100 kHz and 300 GHz (cf. non-ionising radiation).

Helmholtz Zentrum München- German Research Center for Environmental Health

Horizontal pillar
The horizontal pillar is the mining term for the remaining rock between superposing mine openings.

Hot cell
Strongly shielded, tight housing where radioactive materials of high activity are handled by remote control with the help of manipulators and where work processes can be observed through leaded windows, thus not involving risks for the staff.

Hot spots
Spatially limited areas with particularly high absorption of electromagnetic fields.

Household panel
Representative selection of households where interviews have been carried out in intervals.

Hertz (unit of frequency)

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International Atomic Energy Agency: International organisation founded in 1957 for the support of the peaceful application and use of nuclear energy; registered office in Vienna. The IAEA is an independent organisation within the UN.

The IARC (International Agency for Research on Cancer) developed a five-tier classification scheme for carcinogenicity, that is the risk to develop cancer, referring to 935 agents at present (IARC Monographs, Volume 1-100, as of 30 August 2010):

Number of agents
carcinogenic for humans
2A probably carcinogenic for humans
possibly carcinogenic for humans 149
not classifiable as to carcinogenicity for humans
probably carcinogenic for humans

International Commission on Non-Ionizing Radiation Protection. International body in the field of non-ionising radiation, founded in 1992.

International Commission on Radiological Protection. International body in the field of radiation protection. The International Commission on Radiological Protection consists of a chairperson, twelve other members and the secretary. The members are elected through the ICRP of nominations submitted by the national delegations of the International Congress and by their own members. The members of the ICRP are selected on the basis of their acknowledged performance in the fields medical radiology, radiation protection, physics, medical physics, biology, genetics, biochemistry, and biophysics. The ICRP was founded in 1928, then named "International X-ray and Radium Protection Committee", upon decision of the 2nd International Congress for Radiology. In 1950 it was restructured and renamed. The Commission works in close co-operation with the International Commission on Radiological Units and Measurements (ICRU) and has official connections to the World Health Organisation (WHO).

Internationale Kommission für Strahleneinheiten und Messverfahren, International Commission on Radiological Units and Measurements

IMIS is the abbreviation of "Integrated Measuring and Information System for the Monitoring of Environmental Radioactivity". IMIS is a nation-wide comprehensive measuring system which permanently monitors the radioactivity in all important environmental media in the whole area of the Federal Republic of Germany. Federation and Laender share in this task: federal authorities monitor the large-area transport of radioactive substances and their distribution in air and water; Laender authorities monitor radioactivity where radioactive substances deposit and can possibly enter the food chain of man. IMIS comprises more than 2000 stationary measuring stations for the monitoring the gamma dose rate and the activity concentration in air, precipitation and watercourses. Additionally, radioactivity is permanently measured in food, feedstuffs, drinking water but also in residues and waste waters. All measuring institutions at federation and Laender are connected through a computer-aided data monitoring system to the Central Federal Agency at the Federal Office for Radiation Protection.

In vitro
In the test tube (observed or performed).

In vivo
At the living object (observed or performed).

Incidence rate
In a cohort study the incidence rate is the ratio of the incidences to the totality of persons in a cohort observed during a certain period.

Generally: uptake into the body; especially: uptake of radioactive substances into the human body.

Process in which electric current (eddy current) is generated in a conductor when the magnetic flux within this conductor is changed.

Process in which a redistribution of charge occurs through an outer electric field, so that a surplus of positive and negative electric charges occur locally at the surface of this body.

Generally: uptake of food; especially: uptake of radioactive substances with food

Generally: breathing in of gases; especially: uptake of radioactive substances with breathed air

Interim storage
Temporally limited storage of spent fuel elements or radioactive waste prior to their disposal. Spent fuel elements are to be stored in decentralised interim storage facilities on the sites of the nuclear power plants, in fact until they have been conditioned suitably for disposal in a repository.

Interim storage facilities on the NPP site
Facilities where spent fuel elements can be stored in appropriate transport and storage containers on the site of a nuclear power plant until their conditioning suitable for disposal in a repository. Storage time is planned to be 40 years at maximum, starting at loading of the first container.

Nerve cells which serve to control excitation and to process information by switching other nerve cells inhibitorily or excitingly.

Intervention in order to get influence on existing exposure pathways with the objective to effect a reduction in exposure even when parties involved are exposed more during the time of intervention.

Interventional radiology
Procedure in which healing measures – mainly the stretching of narrowed or locked blood vessels are performed under fluoroscopic control.

Discharge or uptake of electrons through atoms or molecules which are converted into an electrically charged state through this.

Ionising radiation
Each type of radiation generating directly or indirectly electrically charged atomic or molecular particles, so-called ions, by taking up or discharging electrons from neutral atoms or molecules and is thus in a position to effect ionisation processes at atoms and molecules in the matter penetrated by it.

  • Alpha radiation:
    Particle radiation in the form of nuclei of the helium element (alpha particles)
  • Beta radiation:
    Particle radiation in the form of electrons (beta particles)
  • Gamma radiation:
    High-energetic, short-wave electromagnetic radiation being emitted at the radioactive decay of a nuclide from the atomic nucleus. It occurs frequently together with alpha and beta radiation
  • Neutron radiation:
    Radiation in the form of electrically neutral elementary particles (neutrons)
  • X-radiation:
    High-energetic, short-wave electromagnetic radiation being generated with the help of technical equipment (X-ray tube). X-radiation and gamma radiation are identical in the basic physical nature.


Atoms of one and the same chemical elements with the same number of protons (same atomic number but different nuclear number) and electrons but different number of neutrons. Isotopes have the same chemical but different nucleonic characteristics.

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Jahresaktivitätszufuhr, Annual Intake of Activity

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Kernforschungsanlage, Nuclear Research Facility

Kernforschungszentrum, Nuclear Research Centre

Electron tube in which high-frequency electromagnetic waves are generated and increased through the energy exchange between an electron beam and standing electric fields.

Kerntechnischer Ausschuss, Nuclear Safety Standards Committee

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Latency period
Time elapsed between exposure to a causative agent (for example radiation exposure) and the appearance of a delayed response in terms of effect (for example clinically manifest cancer).

Linear energy transfer

Cancer of white blood cells; cause widely unknown; incidence frequency 40 – 50 cases per 1 million inhabitants. There are several types with different course of disease and different probability of recovery.

A level is understood to be either the lower boundary layer (floor) of a mine opening or the totality of the mine openings mined on a level.

Lifetime risk
Lifetime risk is a concept of epidemiology meaning the probability of developing a disorder over the course of a usual lifetime.

Literature review
Comprehensive evaluation of scientific publications on a given topic

Liver cell carcinoma
Cancer of the liver cells

Loosely-ionising / lowLET
Loosely-ionising or densely-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.

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Magnetic field
State of the space which manifests itself in force action on magnetic dipoles (magnetic needles).

Magnetic field strength
Measure of the strength and direction of the magnetic field. The measure is Ampere per metre (A/m).

Magnetic flux density
Quantity describing the induction effect of the magnetic field; the measure is Tesla (T). Magnetic flux density and magnetic field strength are connected through permeability µ (a material constant).

Magnetic induction
Magnetic flux density; measure of the number of magnetic field lines per area. The measure is Tesla (T). 1 T = 1 Vs/m² (Volt second per square metre).

Mean value
The mean value (arithmetical) corresponds to the sum of all values of a variable X divided by the number n of the values.

The median is the value which divides the distribution of a variable X exactly in two halves, therefore also the alternative term central value.

Meta studies
Studies where the results of different investigations on a certain topic are compared, summarised and evaluated according to certain parameters.

mikro (µ)
µ = Mikro

Millimeter waves
Millimeter waves belong to the extremely high frequency band of electromagnetic radiation with frequencies from 30 to 300 gigahertz (GHz) and wavelengths between 10 millimeter and 1 millimeter.

In a nuclear reactor, a moderator serves to slow free neutrons produced in the reactor core during the fission process. Similar to billiard balls, neutrons collide with the nuclei of the moderator and thus give off part of their kinetic energy. Since the largest energy transfers occur in the elastic collisions of two equally heavy particles, light atoms such as hydrogen (in the form of water or polyethylene) and carbon (in the form of graphite) are mostly used as moderator. The slowed neutrons are better suitable for both continuing the fission in the reactor core and carrying out scientific experiments in a research reactor.

Change of one or more parameters of a high-frequency carrier wave for the transmittance of information. E. g. in radio programmes (carrier in the MHz range) language (kHz-range) is transmitted by frequency modulation by changing the frequency of the carrier wave in the rhythm of the language signal. Other procedures are amplitude (medium wave) modulation, frequency (UKW) modulation or phase (beam radio) modulation.

Molecular biology
Molecular biology is an interdisciplinary science dealing with the molecular structures and functions in living organisms.

Chemical substance

Monomers are in the strict sense single molecules.

The organic chemist understands monomers to be molecules with a reactive double bond or with functional groups. These can react with each other to long chain molecules, the polymers.

In the case of proteins (white of egg) the term "monomer" means the existence of a single subunit. Some proteins are composed of several monomers.

Incidence, number of diseases within a population

Death rate

Mixed Oxide (Fuel): Nuclear fuel made from a mixture of uranium and plutonium oxide.

Magnetic Resonance Tomography

Broadcast engineering: abbreviation of medium wave
Physics: abbreviation of Megawatt (1 million Watt)

Nuclear medical examination of the heart (Myocardium = heart muscle) for the evaluation of the myocardial circulation and ventricular function of the heart.

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Nuclear Energy Agency

Near field
The calculation of the electric and magnetic field intensities and the power flux density is considerably more complicated in the near field than in the far field. In this area the energy flux pulses away from the source and back to the source.

Near field exposure
Spatial area of the electromagnetic field between the radiation source and its far field (electromagnetic field in the immediate vicinity of the radiation source).

Morphologic changes of cells or tissues following local cell or tissue death, occurring in the living organism.

Net frequencies
For the transmission of electric energy different frequencies are used; in Germany these are 50 Hz for household electricity and 16 2/3 Hz for railway electricity.

Science dealing with the function of the central and peripheral nervous system.

Electrically neutral elementary particle. Neutrons are modules of the atomic nucleus and are released with nuclear fission.

Neutron activation analysis
The neutron activation analysis (NAA) is a highly sensitive method to identify and quantify the (trace) elements in various materials. For this purpose a sample is irradiated with thermal neutrons. The irradiated nuclei can catch a neutron, thus they become activated, i.e. transforming it into a radioactive nuclide. When this nuclide decays, gamma radiation occurs, which has a specific energy for each radionuclide. This gamma radiation can then be allocated to a certain (trace) element, similar to a finger print of a specific person.

Neutron radiation
Neutrons are electrically neutral elementary particles. They are particularly released with nuclear fission, a special form of nuclear transformation. Nuclear fission is only characteristic of heavy atomic nuclei such as the element uranium. As gamma radiation, neutron radiation has a high penetration capacity and requires also an increased use of shielding materials.

Non-ionising radiation
Electromagnetic fields which cannot trigger off ionisation processes at atoms or molecules are referred to as non-ionising. Non-ionising radiation is divided into

  • Static electric and magnetic fields
    (frequency range 0 Hz) e. g. earth's magnetic field
  • Low-frequency electric and magnetic fields
    (frequency range < 100 kHz), e. g. in the case of technical AC
  • High-frequency electromagnetic fields
    (frequency range 100 kHz - 300 GHz), e. g. radio and microwaves
  • Optical radiation
    (wave length range 1 mm - 100 nm), e. g. infrared radiation, visible light, UV radiation


Noxa (from lat. noxa, „damage“)
denotes in medicine a detrimental health effect (like e.g. an injury or radiation) or a substance (like e.g. infectuous or poisonous agents).

Nuclear Power Plant

Nuclear facility/nuclear installation
Facilities for the fission of nuclear fuels and facilities and installations for nuclear fuel supply and waste management.

Nuclear fission
Fission of heavy atomic nuclei by bombardment with neutrons, thus releasing large amounts of energy. With nuclear fission two nuclei of the same size are generated, the radioactive fission products. Besides new neutrons are released which can trigger further nuclear fissions. Nuclear fission can also occur spontaneously, i. E. without excitation from outside.

Nuclear fuel cycle facilities (nuclear fuel supply and waste management facilities)
Facilities in operation and decommissioned for uranium enrichment, fuel element production, reprocessing and conditioning of spent fuel elements. This includes also facilities for the storage of containers with spent fuel elements (temporary storage facilities, interim storage facilities) and of containers with solidified high-radioactive fission product solutions (interim storage facilities) with the objective of later disposal.

Nuclear fuel fission facilities
Among the facilities for nuclear fuel fission are also nuclear power plants and research reactors. Subject to the obligation to report according to the Nuclear Safety Officers and Reporting according to the Atomic Energy Act (AtSMV) are facilities whose maximum output exceeds 50 kW of thermal permanent output (cf. "reportable events").

Nuclear fuels
Fissile materials in the form of uranium as metal, alloy or chemical compound (including natural uranium), plutonium as metal, alloy or chemical compound.

Nuclear medicine
Application of radioactive substances in man for diagnostic and therapeutic purposes.

Nuclear transports
Transport of nuclear fuels or other radioactive substances on public traffic routes and those that can be accessed by the public.

Type of atom characterised by proton number (atomic number) and nuclear number.

Nachweisgrenze, detection limit

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Ortsdosisleistung, ambient dose rate

Organisation for Economic Co-operation and Development

Open radioactive substances
All radioactive substances with the exception of the sealed radioactive substances.

Operation for keeping the mine open
Operation for keeping the mine open is the operation of a repository without emplacement taking place, maintaining all arrangements for radiation protection and mining safety.

Owner of a licence for the operation of a nuclear facility or installation.

Odds Ratio: gives the radio with which "cases" are exposed relatively to controls. With an OR of 1 the part of exposed persons in both groups has been equal. With OR < 1 the part of exposed persons under the cases was less, with OR > 1 more than under the controls. By means of a significance test one can check how statistically important this difference is. For rare diseases the OR can be set equal to the RR.

Organ dose
see “Dose”

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Alleviating the ailments of a disease but not antagonising its cause.

Periodic inspections
Periodic inspections are inspections that are performed periodically at fixed times due to legal regulations, obligations by the authority or other stipulations.

Apart from the necessary regular testing of the material of the pressure retaining boundary of the reactor cooling system and other safety-related pipe systems and containments, the purpose of the periodic inspections is also the regular proof of functional reliability of components of the safety system which are in operational readiness. This is to prevent a failing of components and systems in case of demand to the best possible extent (cf. definition "availability").

Statistical value kept by a certain percentage of the measured results of a random sample (e. g. 95 % percentile is the value which is only exceeded by 5 % of the random sample).

Permeability e. g. of membranes

Personal dosimeter (non-ionising radiation)
Measuring device for the determination of the level of exposure to low-frequency or high-frequency electromagnetic fields on a single person.

Positronen-Emissions-Tomography: Positron Emission Tomography

Spatial distance of equal conditions of vibration of two harmonic vibrations.

Physiology deals with the physical and biochemical functions of cells, organs and the whole body of creatures.

Pilot study
siehe feasibility study

Plan-approval (licensing) decision
The plan-approval (licensing) decision is an administrative act with which the admissibility of a project is determined, including all other necessary licences, permits, etc..

94. element in the periodic system; the isotope Pu-239 (half-life 24,110 years) is of special importance because it is a fissile material. Plutonium is produced by neutron capture from uranium-238 and two following beta decays. Only very small amounts of plutonium occur naturally.

Potash salts
Easily soluble salt minerals (carnallite, kainite, sylvine and others) which are of special interest in salt mining due to their value and their different possibilities of economic use. Due to their high crystal water content potash salt areas are to be avoided in the disposal of radioactive waste.

Potential danger
Inherent suitability of a procedure, condition or state to trigger off a damage.

Power flux density
In the area of high-frequency radiation the power flux density is the measure of the strength of the radiation in the far field; its measuring unit is Watt per square metre (W/m²). It characterises the energy flowing per time unit through an area vertical to the distribution direction of the radiation. If the high-frequency radiation is emitted by an antenna, the following applies: The greater the distance from the antenna the less the power flux density.

Frequency of a disease at an appointed date.

Principle of Precaution
Dictum of action stating that preventive measures have to be taken to avoid damage in case of lacking of scientific certainty as to the extent and the consequences of a danger of man and environment (e. g. due to a new technology). In the case of mobile telecommunication the preventive measures concern in particular the informing of the public, the intensification of research and the reduction of exposure.

Profile study
Profile studies comprise a selection of persons from a target population at a certain date (appointed date). For the selected persons the disease state and the present or earlier exposure are queried simultaneously.

Proof of long-term safety
The proof of long-term safety has to furnish proof within the scope of the plan-approval (licensing) procedure that it is guaranteed that the emplaced radioactive waste remains safe over the necessary period of time – cf. disposal.

Prospective approach
An investigation approach where a defined group of persons is observed anticipatorily over a certain period of time in the future.

Electrically positively charged particle, together with neutrons it forms the atomic nucleus.

The Federal Institute of Physics and Metrology (Physikalisch-Technische Bundesanstalt, PTB) Braunschweig and Berlin is a scientific and engineering state institute and technical superior authority of the Federal Republic of Germany for metrology and physical safety technology. It is the successor of the Physikalisch-Technische Reichsanstalt founded in 1887 in Berlin. The PTB belongs to the portfolio of the Federal Ministry of Economy and Technology. It has about 1650 members of whom about 1300 work in Braunschweig. The tasks and activities of PTB can be divided in four areas:

  • Principles of metrology,

  • Metrology for the legally regulated area,

  • Metrology for the industry,

  • International cooperation.


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For the whole range of a variable X it can be estimated with the help of the cumulative frequency distribution which part of all investigation units shows a value x at maximum. This value is termed quantile or when using percentages, percentile.

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Radar (radio detection and ranging)
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 is a form of energy dispersing as electromagnetic wave - or as particle radiation - through room and matter.

Radiation exposure
The term radiation exposure is used for the effects of radiation on the human body. In the case of external radiation the radiation has an external effect on the body. The term internal radiation exposure is used for the internal effects of radiation caused by radionuclides incorporated with the breathing air (inhalation) and with food (ingestion).

Radioactive substances
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.

Characteristic of certain atomic nuclei (radionuclides) to convert into other atomic nuclei without extraneous cause, emitting ionising radiation. Measuring unit is "activity" i. e. the number of nuclear transformations of a radionuclide or radionuclide mixture occurring per time unit. The measure 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.

Radioactive iodine isotopes.

"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.

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.

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.

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. 

Radon 222 is a natural decay product of the uranium-thorium series which exists all over the earth and contributes considerably to the natural environmental radioactivity. It 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. Through further decay again 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.

Conscription, composition

Redox potential
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).

An example is the combustion of carbon to carbon dioxide:
C C4+ + 4 e-
(loss of electrons)
O2 + 4 e- 2 O2- (gain of electrons)
in total: C + O2 CO2

Reference nuclide
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.

Regulatory Authority for Telecommunication and Post (Regulierungsbehörde für Telekommunikation und Post)

Guideline Relating to Emission and Immission Monitoring of Nuclear Facilities (Richtlinie zur Emissions- und Immissionsüberwachung kerntechnischer Anlagen)

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

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

Reportable events
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.

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.

Resonance frequency
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 of the eye; optical signals are transformed into nerve signals here.

Retrospective approach
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.

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.

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

Rock salt
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.

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

Röntgenverordnung, X-ray Ordinance

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 < 1 the risk is lower in the exposed group, with RR > 1 higher than in the non-exposed group. By means of significance test it can be investigated how statistically significant this difference is.

The "Reaktor-Sicherheitskommission" (RSK) was established by statute in 1958 to advise the BMU 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 BMU 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.

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Symbol of power flux density

Safety assessment
Within the scope of a safety assessment possible radiological consequences of a repository in normal operation, in the post-closure phase and in case of incidents are assessed and evaluated with the help of calculations and investigations.

Safety specifications
The safety specifications contain all plant regulations, that are necessary for the safety of the plant and its operation, and all information and measures required to control events and design basis accidents.

The purpose of the safety specifications is to provide the plant personnel with the important data, limit values and measures necessary for the safety of the nuclear power plant and its operation including the necessary indications to safety-related basic design conditions.

Salt grit
Fine-grained salt rock material

Specific absorption rate

Deposits in pipelines are called scales. For instance, in geothermal facilities this term is used as well for fouling at heat exchangers.

Imaging diagnosis method, where radioactive substances (drugs) are brought into the body of the patient. This nuclear-medical examination provides statements on the function of different organ systems with regard to general disorders of the metabolism and to locally described foci in single organs.

Voluntary self-commitment of the mobile network operators towards the Federal Government of 6th December 2001 with the objective to further improve precaution in the area of mobile telecommunication. Central contents: improvement of the information of authorities in situ, common use of antennae sites, alternative site inspection at kindergartens and schools, improvement of consumer protection, marking of mobile phones and enhancement of research. Furthermore the mobile network operators propose to set up a measuring network for the continuous monitoring of electromagnetic fields.

SI unit of the dose equivalent and of the effective dose 1 Sievert (Sv) = 100 Rem, 1 Sievert = 1,000 Millisievert (mSv) = 1,000,000 Mikrosievert (µSv).

One talks about statistical significance if the observation of a population group clearly deviates from the expected value. To be able to evaluate this statistical methods are applied which compare the number of diseases observed in an examined population group with the number of the cases expected in this group, if the diseases in the observed group occurred with equal frequency – referred to the considered number of persons – as in the comparison group. As these are random samples, one cannot just say these are more or less, but for this statement one has to state an error probability. It has been agreed that a deviation between observed and expected case numbers is considered to be significant if this error probability is less than 5 %.

Sinking means vertical working into the rock with different procedures, such as e. g. drilling and blasting work. A shaft is sunk.

Standardised Incidence Ratio / Standardised Mortality Ratio) : The ratio between the probability of falling ill in a cohort and in a comparison group (mostly the total population). With an SIR/SMR of 1 there is no difference between the two groups. With SIR/SMR < 1 the risk in the cohort is smaller, with SIR/SMR > 1 larger than in the comparison population. By means of a significance test it can be checked how statistically significant this difference is.

Units of the International System of Units (SI). The application of the units in radiation protection measurements is regulated by the Ausführungsverordnung zum Gesetz über Einheiten im Messwesen of 13th December 1985 (BGBl. I p. 2272).

Interrelation between the valid SI-units and the units in radiation protection no more permitted officially since 1985:
  SI-unit old unit Relation
Activity Becquerel (Bq);
1 Bq = 1/s
Curie (Ci) 1 Ci =
3,7 · 1010 Bq
1 Bq ~ 2,7 · 10-11 Ci
Energy dose Gray (Gy);
1 Gy = 1 J/kg
Rad (rd) 1 rd = 0,01 Gy 1 Gy = 100 rd
Dose equivalent
Effective dose
Sievert (Sv);
1 Sv = 1 J/kg
Rem (rem) 1 rem = 0,01 Sv 1 Sv = 100 rem
Ion dose Coulomb pro kilogram (C/kg) Röntgen (R) 1 R =
2,58 · 10-4 C/kg
1 C/kg ~ 3876 R


Physical phenomenon: suppression of the alternating current to the surface of the conductor with increasing frequency

Specific absorption rate
The specific absorption rate (SAR) describes the energy taken up by the body in the high-frequency field per kilogram body weight in a certain time and which is mainly transformed into heat; its measure is Watt per kilogram (W/kg). The SAR is averaged over 6 minutes time of affect; then a balance has formed through heat regulation of the body between heat input and heat output. Prior to this the increase in body temperature is only determined by the energy taken up. By averaging over different mass areas it is differentiated between affects on the whole body and affects on smaller tissue areas. For example, when averaging over 10 g of body tissue – which corresponds to the mass of the eye – the inhomogeneous energy distribution in the near field area of antennae is taken into account (e. g. when using mobile phones).

Single-Photon-Emissionscomputertomographie, Single Photon Emission Computed Tomography

Commission on Radiological Protection; According to the statute of the Commission on Radiological Protection (SSK) of 22nd December 1998 the SSK have the task to advise the Federal Ministry for the Environment, Nature Conservation and Nuclear Safety in issues relating to the protection against the danger of ionising and non-ionising radiation. In detail the tasks of SSK comprise the following:

  • Statements and recommendations for the evaluation of biological radiation effects and on dose-effect relations
  • Elaboration of proposals for dose limit values and limit values derived from them
  • Observation of the development of radiation exposure of the total population, special population groups and occupationally exposed persons
  • Proposal of and advisory service relating to the elaboration of guidelines and special measures for the protection from dangers of ionising and non-ionising radiation
  • Advisory service relating to the elaboration of recommendations on emergency management and in the planning of measures to reduce radiation exposure in nuclear facilities


Part of the population who are organised as a group and who represent their joint interests

Radom; stochastic radiation damages are damages whose probability of occurrence but not its seriousness depends on the dose.

Strahlenschutzverordnung, Radiation Protection Ordinance

Strahlenschutzvorsorgegesetz, Precautionary Radiation Protection Act

Study populations
Random sample of a basic collectivity of persons at whom the investigation is carried out.

Dissolving (leaching off) occurring under the earth's surface of deasily dissolvable rocks, in particular salts, through groundwater. Such underground leaching off can result in a sinking of the overlying rock section so that a depression forms at the earth's surface (subrosion depression).

Boiling water reactor. Power reactor at which – in contrast to the pressurised water reactor (DWR) – a part of the cooling water boils inside the reactor and the heat is discharged as steam. The wet steam or saturated steam generated in this way is directly used for driving the turbine and the generator to produce electric current.

Joint of two nerve cells serving to transfer impulses.

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Treatment of diseases by irradiation of the body from outside.

Nuclear power plant in the South Bohemian Temelin, Czech Republic. The existence of the NPP is questionable from the point of view of safety and economy and is accompanied by a transboundary environmental impact assessment (EIA).

Temporary storage facility
Installations where spent fuel elements are stored so long on the site of a nuclear power plant in suitable transport and storage containers until a decentralised interim storage facility is available, at maximum for 6 to 8 years, however.

Damaging the fruit; causes deformities of the seedling due to chemical and physical agents.

Terminal points (hard, weak)
Types of diseases investigated in epidemiological studies. Among the "hard" terminal points are e. g. overall mortality rate, selected causes of death, cancer diseases, etc. while "weak" terminal points are diseases such as headaches, sensitivities disturbances, etc..

Terrestrial radiation
Radiation emanating from natural radionuclides and their decay products available in the soils and rocks of the earth's crust.

Tesla (T)
Tesla is the unit of magnetic flux density.

Terrestrial Trunked Radio. European radio standard. TETRA is used for the Digital Radio of Security Authorities and Organisations at frequencies between 380 and 395 MHz.

Thermoluminescence dosimeter
Thermoluminescence dosimeters (TLD) can be used to detect ionising radiation (radioactivity). Thermoluminescence describes the capability of a material to emit the previously stored energy in the form of light when the material is heated. The level of ionising radiation is determined by evaluating the quantity of emitted light. This is directly proportional to the energy taken up originally.

Threshold value
Damage occurs only when a minimum dose is exceeded.

Gas-filled switch duct similar to an amplifier duct (triode) whose main discharge is initiated by a grid-like electrode. These ducts are used for the impulse modulation of magnetrons and other oscillators and as quick electronic switches. Larger structural forms serve for engine management systems, controlled rectifiers or to handle more efficient switches.

Time Division Multiple Access (TDMA)
Procedure which enables within the scope of digital telecommunication to transfer several calls simultaneously on one transmitting frequency. Each call is assigned one time division in which the temporally distributed transmitting signals (digitised and compressed language "packages") are transmitted. In the GSM system, for instance, 8 time divisions of 577 µs each are used to transmit up to 8 talks simultaneously.

Top of salt dome
Top of salt dome is a horizontal surface above salt deposits or salt domes generated by "leaching". Mostly a so-called cap rock is situated on the top of salt dome consisting of the hardly soluble components of the leached off salt.

Transmitting power
Electrical power emitted from an antenna.

Transport licenses
With respect to nuclear transports, transport licences are granted by the Federal Office for Radiation Protection if the legal prerequisites are complied with, in particular the precaution against damage according to the state-of-the-art of science and technology.

Radioactive isotope of hydrogen with 2 neutrons and 1 proton in the nucleus, forming the decay products helium-3 and emitting beta radiation during decay; physical half-life ca. 12.3 years; effective half-life when taken up once ca. 10 days. Tritium can replace hydrogen in all metabolic processes; no enrichment over the food chain.

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The need for research resulting from the departmental tasks of the Federal Ministry for the Environment, Nature Conservation and Nuclear Safety is annually determined in an environmental research plan (Umweltforschungsplan, UFOPLAN).

Universal Mobile Telecommunication System; mobile telecommunication system of the so-called "third generation" which, in addition to language transmissions, admits image and video transmission due to high transmission rates. From 2003 on, UMTS is supposed to use frequencies between 1920 and 1980 MHz and between 2110 and 2170 MHz.

United Nation's Scientific Committee on the Effects on Atomic Radiation. UNSCEAR regularly elaborates reports for the UN plenary meeting on radiation exposure and the effects of ionising radiation.

Natural radioactive element. Naturally occurring isotopes are the fissile uranium-235, uranium-238 which cannot be split with thermal neutrons, and uranium-234.

Uranium enrichment
Physical procedure with which the percentage of the fissile isotope Uranium-235 (U-235) can be increased beyond the content of 0.72 % of natural uranium. In the Federal Republic of Germany a uranium enrichment plant is operated for this purpose by URENCO Deutschland GmbH in Gronau where uranium – in the form of the volatile chemical compound uranium hexafluoride (UF6) – is enriched with the help of a gas centrifugal system on a large technical scale.

Uranium ore mining
Right after the end of World War II the Wismut company started to win uranium in Saxony and Thuringia. Uranium mining which had in particular in the initial years been carried out regardless of man and the environment has led to massive damage caused to the environment.

UV index
The UV index describes the daily peak value of the sunburn effective UV radiation expected at the ground. The population has thus the possibility to ask for information relating to the danger of solar UV radiation at the Federal Office for Radiation Protection.

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Volt (unit of electric voltage)

Ventilation is the planned supply of the mine with fresh air.

Vitrified waste canister
In nuclear energy a term for a melted, vitrified block of high-level radioactive waste including its metal housing made from corrosion-resistant steel which is welded gas-tight.

Verordnung über die Gewährleistung von Atomsicherheit und Strahlenschutz der ehemaligen DDR, Ordinance on the Guarantee of Nuclear Safety and Radiation Protection of the former GDR

Measure of the labour required for bringing a charge in an electric field from one point to another, divided by the charge. The unit is Volt (V).

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Watt (unit of power)

Wiederaufarbeitungsanlage, reprocessing plant

Wash bottle
Wash bottles are laboratory devices that are included in a gas flow (e.g. in the branch of an exhaust air flow from a mine). Through an immersion tube (similar to a straw dipped into a liquid) the gas is forced to run through a liquid contained in the bottle before it leaves the bottle again. Thus it is possible to examine the composition of gases: Gases soluble in the liquid and entrapped airborne particles (aerosols) remain in the liquid and can be determined subsequently.

Wave length
Distance covered by a wave during one period

Weltgesundheitsorganisation, World Health Organisation

Whole-body counter
Measuring instrument for the detection of the activity of radionuclides in the whole human body. Only radionuclides emitting gamma radiation can be measured.

A whole-body counter mostly consists of

  • a couch or a chair the person to be examined is lying or sitting on during the measurement,
  • one or several detectors to measure the gamma radiation emanating the measured person’s body during the measurement, and
  • a suitable shielding of the measuring instrument against environmental radiation.

Older devices use sodium iodide detectors. Instead of these, highpure germanium detectors are used increasingly, the latter having a significantly higher energy resolution (the higher the energy resolution, the better the various measured radionuclides can be distinguished from each other).

Whole-body dose
Product of the mean absorbed dose of the whole body and the radiation weighting factor. If several types of radiation are involved the total whole-body dose is the sum of the respective components. The unit of the whole-body dose is J/kg with the special name Sievert (Sv).

Working Level Month

The unit Working Level Month (WLM) is frequently used in the risk assessment of occupational radon exposure instead of a calculated dose in Millisievert. The advantage is, that the concentration can be measured directly. No further assumptions for the dose distribution in the body are necessary.

To calculate the cumulative exposure to radon in WLM, the measured alpha energy concentration (unit: Working Level (WL)) in one litre air is multiplied by the time the miner has worked in this surrounding.

1 WLM equals an exposure of 1 WL (1,3 * 105 Megaelectron-volt (MeV) potential alpha energy per litre air) over 170 working hours (monthly working time), or a half WL over 2 months (340 working hours), respectively.

Worst-case scenarios
The worst case; corresponds to the concurrence of the most unfavourable conditions occurring in reality.

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X-ray Ordinance
The X-ray Ordinance (Röntgenverordnung, RöV) regulates the operation of X-ray devices. It additionally deals with the technical equipment in which as a side effect X-radiation is generated by the acceleration of electrons.

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Zentralstelle des Bundes, Central Federal Agency for the Surveillance of Radioactivity

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