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Englischsprachiges Glossar

Near fieldshow / hide

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 show / hide

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

Necroses show / hide

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

Negligible heat generationshow / hide

Radionuclides cause a raise in temperature as a result of the heat produced during radioactive decay. For waste with negligible heat generation, the rise in temperature in the surrounding iron ore must not exceed three degrees Celsius (three degrees Kelvin).


Net frequenciesshow / hide

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.

Neurophysiology show / hide

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

Neutron show / hide

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

Neutron activation analysisshow / hide

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 radiationshow / hide

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 radiationshow / hide

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,
  • 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.

Normal Operationshow / hide

Operational processes the facility is designed and appropriate for in operational condition of the systems (undisturbed condition); also operational processes running with malfunctions of plan/facility components or systems (disturbed condition), as long as safety-related reasons are not opposed to the operation continuing (abnormal operation); maintenance processes (inspection, machine care, repair).

Noxa (from lat. noxa, "damage") show / hide

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 facility/nuclear installation show / hide

Facilities for the fission of nuclear fuels and facilities and installations for nuclear fuel supply and waste management.

Nuclear fission show / hide

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 fuelshow / hide

Fissile materials: uranium-based as a metal, alloy or chemical compound (including natural uranium) or plutonium-based as a metal, alloy or chemical compound.

Nuclear fuel cycle facilities (nuclear fuel supply and waste management facilities) show / hide

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 facilitiesshow / hide

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 show / hide

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 show / hide

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

Nuclear transports show / hide

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

Nuclide show / hide

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

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