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Englischsprachiges Glossar

Federal Institute of Physics and Metrology (Physikalisch-Technische Bundesanstalt, PTB) show / hide

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.

Packagingshow / hide

Entirety of non-reusable containers surrounding a waste package.

Palliativ show / hide

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

Parallel road(s)show / hide

Parallel access road(s) to the emplacement chambers.

Percentile show / hide

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).

Periodic inspections show / hide

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").


Permeability show / hide

Permeability e. g. of membranes

Petrography (science of stones)show / hide

Science dealing with the composition of rocks, their natural occurrence, their interrelation and their formation and transformation.

Phase show / hide

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

Physiology show / hide

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

Pillarshow / hide

Part of a mine remaining standing between mine openings/chambers that is not mined and ensures that the rock is connected.

Pit bankshow / hide

Place in the head frame at ground level, where the cage is loaded or unloaded.

Pit watershow / hide

Water flowing into the mine from various sources. Most of it is a by-product of the mine ventilation.

Plan-approval (licensing) decision show / hide

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.

Planning approval procedureshow / hide

Spatial projects are developed and implemented in a planning approval procedure.

Plutonium show / hide

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.

Pool palletshow / hide

Reusable device for the transport of cylindrical waste packages.

Porosityshow / hide

The total volume of a rock is composed of the volume of the solid components and the volume of the cavities or pores in the rock. The total porosity is defined as the ratio of the pore volume and the total volume of the rock. The effective porosity is defined as the ratio of the pore volume usable for the flow of groundwater and the total volume of the rock.

Portlanditeshow / hide

Mineral (Ca(OH)2), calcium hydroxide.

Post-closure phaseshow / hide

Period following the closure of a repository mine

Potashshow / hide

Potash (or potassium) salt: Rock or mining product from different salt minerals with a high portion of potassium compounds.

Potash salts show / hide

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 show / hide

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

Power flux densityshow / hide

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.

precipitationshow / hide

Separation of a dissolved substance from a solution.

Pressurised water reactorshow / hide

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.

(German: Druckwasserreaktor - DWR)


Prevalence show / hide

Frequency of a disease at an appointed date.

Preventershow / hide

A preventer is a device drillings are sealed with during the drilling process to prevent gases or liquids from escaping the bore hole.

Primary wasteshow / hide

Untreated radioactive waste.

Principle of Precaution show / hide

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 show / hide

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 show / hide

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.

Prospective approach show / hide

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

protection goalsshow / hide

Goals worth being protected in legal provisions.

Proton show / hide

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


provisionsshow / hide

In the licensing requirements for the storage of radioactive waste in a repository it is set out that the “necessary state-of-the-art of science and technology provisions against damages due to the construction and operation of the facility must be taken”. All measures taken as precautions to guarantee this requirement are referred to as provisions.

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