The mining term for above ground, above the earth‘s surface. Underground is the opposite of above ground and describes areas not reached by daylight. Drill holes, which explore areas from the earth’s surface, are above ground. If, however, the exploration work is performed from a mine, it is underground.

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.

Process used to make a material radioactive by bombarding it with neutrons, protons or other particles.

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.

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

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.

Brattice to direct air flows underground (ventilation).

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.

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.

Particles produced through radioactive decay, consisting of two neutron and two protons.

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.

The law governing the peaceful use of nuclear energy and protecting against its risks dating back to 1959; fundamentally amended in 2002 to legally settle the nuclear phaseout. Following the Kalkar decision by the Federal Constitutional Court in 1978, parliament is responsible for the fundamental normative decision in favour of or against using nuclear energy.

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.