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.

Material used to backfill the cavities resulting from mining or that are still open after radioactive waste has been emplaced.

Filling debris of a special grain size into filled emplacement chambers and other mine openings with the objective to minimise remaining cavities.

Filling up residual cavities between the roofs of the mining districts (cavity where no radioactive waste has been emplaced) and the salt backfill.

Identification and activity determination of radionuclides or radionuclide groups and their comparison with the respective authorised limits.

Rock layer limited by (layer) joint.

Intact state of barriers in which they fulfil their function.

Geological conditions or technical/geotechnical measures to impede or prevent the release of harmful substances from the waste into the biosphere.

Geological conditions to prevent inadmissible releases of radioactive materials (such as repository formation, adjoining rock or overburden).

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.

Technical measures to prevent inadmissible releases of radioactive materials (such as waste product, package, stowage or shaft sealing).

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

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.

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).

Particles produced through radioactive decay, consisting of electrons or respectively positrons.

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

Inclined or vertical connection of mine openings that were e.g. driven in the period of salt production in the Asse mine, to mine salt by using gravity.

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".

Influences on living material (organisms, tissues, cells).

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

Chemical element with the symbol Bi and the atomic number 83; Bismuth was considered the heaviest stable chemical element until the radioactivity of the isotope ²⁰⁹Bi was discovered in 2003. The naturally occurring Bismuth consists entirely of ²⁰⁹Bi, which has a very long half-life (about 19 quintillion years). Therefore, its specific activity is very low and cannot be detected with normal measuring devices. It decays via alpha decay to the stable Thallium isotope ²⁰⁵Tl. The Bismuth isotopes ²¹⁰Bi, ²¹¹Bi, ²¹²Bi and ²¹⁴Bi are members of the three natural decay chains (so-called radiogenic radionuclides) and therefore always exist in traces in the environment.

Immobilisation of radioactive waste in a bitumen matrix.

Vertical mine opening (shaft) not connected to the surface.

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.

Cable carrier of a hoisting machine for the sinking of shafts; it uses a flat rope as conveyor cable. The flat rope generates no spin and can be wound one on top of the other.

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).

Transition zone from shaft to mine.

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

Management of liquids existing in the mine, e.g. collection and transport of influent saline solutions.

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.

Cancer of the bronchi, lung cancer.

Magnesium containing mineral contained in the magnesium depot, Mg(OH)2.

Storage hall in which waste packages can be deposited in exceptional circumstances in order to ensure fault-free operation of the storage process.

Passage way between the transfer hall and the shaft hall, used to park the flatbed rail wagons.

Facility for the production of building materials (such as Sorel concrete).