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Glossary

Englischsprachiges Glossar

Federal Radiological Situation Centre (RLZ)Show / Hide

The Federal Radiological Situation Centre (Radiologisches Lagezentrum- RLZ) is a special crisis team that is convened and managed only temporarily by the Federal Environment Ministry in the event of an emergency.

The establishment and tasks of the Federal Radiological Situation Centre are regulated in the Radiation Protection Act.

Radar (radio detection and ranging)Show / Hide

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

Radiation Show / Hide

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

Radiation exposureShow / Hide

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

In the case of humans, a distinction is made between

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

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

Radiation protectionShow / Hide

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

Radiation protection areasShow / Hide

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

Radiation Protection OrdinanceShow / Hide

The "Ordinance on protection against the harmful effects of ionising radiation" (Radiation Protection Ordinance) is part of radiation protection legislation in Germany. The "First Radiation Protection Ordinance" dates back to 1960. The radiation protection legislation has been amended several times since then to reflect the current state of science.

The Ordinance contains regulations on protection against ionising radiation at home, at work, or when visiting a doctor and sets out the requirements of the Radiation Protection Act in concrete terms.

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Radioactive contaminationShow / Hide

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

Radioactive equilibriumShow / Hide

With regard to a decay series, radioactive equilibrium refers to a condition in which the (activity) ratio between the parent nuclide and each of its radioactive decay products is constant.

This means that each daughter nuclide (decay product) is decaying at the same rate as it is being newly created. The activity ratios between the individual radionuclides of the decay series therefore remain constant.

A radioactive equilibrium can only come about if the following conditions are met:

  • The half-life of the parent nuclide is longer than the longest half-life of the decay products.
  • Sufficient time has passed for an equilibrium to develop.
  • There are no interfering factors that affect the radionuclides of a decay series in different ways.

Radioactive substancesShow / Hide

In the colloquial sense, a radioactive substance is any substance that contains one or more radionuclides.

In the legal sense, the term radioactive substance refers to any substance containing one or more radionuclides and whose activity or specific activity cannot be disregarded in the context of radiation protection and statutory regulations. Corresponding legal definitions are laid down in:

Alternative

Radioactive wasteShow / Hide

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

RadioactivityShow / Hide

Characteristic of certain atomic nuclei (radionuclides) to convert into other atomic nuclei or change from a high-energy (metastable) state to a lower-energy state without extraneous cause, emitting ionising radiation.

Measurand is the activity, i.e. the number of nuclear transformations of a radionuclide occurring per time unit. The unit of the activity is the 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. Each radionuclide is characterised by its half-life and the type and energy of the ionising radiation emitted.

Radioiodine Show / Hide

Radioactive iodine isotopes.

Radioisotope applicationShow / Hide

The term "radioisotope" is used as a synonym for "radionuclide". Special radionuclides are used for medical applications, for example in cancer therapy.

RadioisotopesShow / Hide

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

Radiological Situation Report (RLB)Show / Hide

In the event of a radiological emergency of supra-regional significance, the Federal Radiological Situation Centre assesses the radiological situation in the form of the "Radiological Situation Report". The Radiological Situation Report has several sections and contains information on the current radiological emergency prepared specifically for radiation protection experts and those responsible for civil protection.

The creation and contents of the Radiological Situation Report are regulated in the Radiation Protection Act.

RadiolysisShow / Hide

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

RadionuclideShow / Hide

A radionuclide is an instable nuclide which changes from a high-energy (metastable) state to a lower-energy state or decays into another nuclide spontaneously without extraneous cause emitting high-energy (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.

RadiosynoviorthesisShow / Hide

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

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

RadiotoxicityShow / Hide

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

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

RadiumShow / Hide

Radium is a chemical element with only radioactive isotopes.

The naturally occurring isotopes are formed during the radioactive decay of uranium (U-235, U-238) and thorium (Th-232), which are present in all soils and rocks. Naturally occurring radium isotopes that can contribute to a significant radiation dose to humans are

  • Radium-224 (physical half-life 3.66 days; alpha emitter),
  • Radium-226 (physical half-life 1600 years; alpha emitter) and
  • Radium-228 (physical half-life 5.75 years; beta emitter).

Alpha emitters are again among the daughter nuclides of these radium isotopes.

Radium is chemically similar to the mineral calcium. Most of the radium that enters the human body with food is excreted immediately. Only a small proportion is absorbed into the body via the gastrointestinal tract, where about a quarter to a third is initially stored in bones and then slowly released from bones. In the case of short-lived radium isotopes, the activity in the human body decreases rapidly due to radioactive decay corresponding to the physical half-life.

Radium-223 (physical half-life 11.4 days; alpha emitter) is produced artificially for medical purposes. This radium isotope is used to treat bone metastases.

RadonShow / Hide

Radon is a noble gas which is colourless, odorless and flavourless, does not bind and escapes via cracks and gaps from the earth into the breathing air. Radon exists only as radioactive isotopes. Radon-222 is the isotope with the longest half-life of almost 4 days. It is a natural decay product of the uranium-radium series which exists all over the earth and contributes considerably to the natural environmental radioactivity.

In addition, the short-lived radon-220, traditionally called "Thoron", is also found. Because of its short half-life of only 55 seconds, it cannot move far.

The decay of radon triggers a whole chain of further decays. Radon and the similarly radioactive decay products can enter the lungs via the air we breathe and emit i.a. alpha radiation. Alpha radiation can damage the cells of the lung. These damages can favour the generation of cancer.

Radon exhalationShow / Hide

Materials that contain radionuclides from the uranium/radon decay series can release radon into ambient air. This process is collectively described as radon exhalation.

radon monitorShow / Hide

Measuring device for determining the radon concentration in the air.

Radon potentialShow / Hide

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

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

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

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

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Reaktor-Sicherheitskommission (RSK)Show / Hide

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

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

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

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

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Receiving watersShow / Hide

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

RECIST guideline Show / Hide

The "response evaluation criteria in solid tumors" (RECIST) guideline defines criteria for evaluating how a solid tumour responds to treatment.

Recruitment Show / Hide

Conscription, composition

Red mudShow / Hide

Red mud is a waste product of aluminium production. The starting material for the production of aluminium is bauxite, which is digested using sodium hydroxide. This causes aluminium to be dissolved out of the ore.

Redox potential Show / Hide

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

Reference nuclide Show / Hide

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

Reflection seismicsShow / Hide

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

Relative risk Show / Hide

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

Release of radioactive substances Show / Hide

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

Reportable eventsShow / Hide

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

RepositoryShow / Hide

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

ReprocessingShow / Hide

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

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

Reprocessing plantShow / Hide

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

Resonance frequencyShow / Hide

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

Retina Show / Hide

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

Retrospective approach Show / Hide

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

Reviews Show / Hide

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

Risk Show / Hide

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

Risk communication Show / Hide

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

Risk perception Show / Hide

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

Risk Ratio/Relative Risk (RR)Show / Hide

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

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

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

Alternative

Rock mechanicsShow / Hide

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

Rock salt Show / Hide

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

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