Areva - Reference Document 2016
GLOSSARIES 1. Technical glossary
> Storage Temporary storage of radioactive materials or waste in a facility that is specifically designed for that purpose, pending their removal. > STUK Counterpart to the Autorité de sûreté nucléaire (French nuclear safety authority ASN). Field of jurisdiction: nuclear safety and radiation protection. > SWU (separative work unit) An enrichment plant’s production is expressed in SWU. This unit is proportionate to the quantity of uranium processed and is a measure of the work required to separate the fissile isotope. > TDG order French modal order of May 29, 2009 on the transport of dangerous goods (“TDG order”). The order applies to the national or international carriage of dangerous goods by road, rail and inland navigation in France, including loading and unloading operations, intermodal transfers and halts required by transportation circumstances. The order stems from international and European Community laws and applies in particular to the carriage of radioactive materials (class 7 carriage). > Ten-year inspection Every ten years, nuclear reactors are inspected thoroughly, including a detailed inspection of its principal components: the reactor vessel, the primary cooling system, and the reactor containment. > Thermonuclear fusion The energy from the stars, such as the sun, is produced by the nuclear process of fusion of light atoms, such as hydrogen. Fusion is the opposite of fission, for it corresponds to the merging (rather than the splitting) of atomic nuclei. > Thorium Natural radioelement (232 isotope) that can produce the fissile uranium isotope of uranium, 233 U, through neutron capture. > Tokamak Acronym from the Russian expression toroidalnaya kamera magnitaya katushka , whichmeans “toroidal chamber andmagnetic coil”. The International Thermonuclear Experimental Reactor (ITER) aims to study hot plasmas in this configuration. > Torrefaction Torrefaction (or depolymerization) of biomass is a mild form of thermo-chemical treatment (from200 to 320 ) used to eliminate water and change part of the organic material used in biomass to break down its fibers. During the torrefaction process, light organics are removed and the structure of the biomass is depolymerized and changed, causing the fibers to break. Torrefied biomass, also called biocoal, is a high-quality solid fuel that is ideal for certain types of industrial applications, both general and specific, including electricity generation, heat production, cogeneration and central heating. This new fuel opens up newpossibilities for renewable energies.
> Trading Commercial transactions in the natural uranium market not directly connected to the group’s mining operations, in the form of the purchase, sale, exchange, lease or loan of uranium. > Transportation emergency response and management plan Instantly activated in the event of a transportation incident involving radioactive materials. It covers the phases of alert, situational analysis and response in the field following an incident or accident involving the transportation of radioactive materials. It makes available specialized human resources and special equipment to the competent authorities. The entire plan is tested on the national scale once a year on average with the leading players, and in particular the competent authorities. > Transuranic elements Chemical elements in which the nucleus contains more protons than uranium, which has 92. The first transuranic elements are, in increasing order, neptunium, plutonium, americium and curium. > Tritium Isotope of hydrogen whose nucleus consists of one proton and two neutrons. It emits beta rays and is present in the natural state in the air and in effluents from light water reactors. Tritium and deuterium are the two reagents chosen for controlled fusion projects. > Turbine Device used to convert the energy contained in a fluid (water, steam, gas, etc.) into a rotary motion. The turbine is also used to drive the rotation of a current generator in units that generate electrical energy. > UF 4 Uranium tetrafluoride. > UF 6 Uranium hexafluoride. > Unit, nuclear unit Unit for power generation consisting of a nuclear steam supply system, including the reactor, and a turbogenerator. Nuclear power plants generally have several units on one site. p Becquerel (Bq): international unit of measurement of activity (1 Bq = one atomic particle disintegration per second). The becquerel is a very small unit. Previously, nuclear activity was measured in Curies (one curie = 37,000,000,000 Bq, corresponding to the activity of one gram of natural radium). p Sievert (Sv): legal unit of dose equivalent, used to determine the biological effects produced by a given absorbed dose on a living organism. Dose equivalent is not a measurable physical quantity; rather, it is calculated. It is determined by multiplying the absorbed dose (expressed in grays, where 1 gray = 1 joule per kg) by two coefficient factors which depend on the type of radiation and the type of tissue affected. The millisievert (mSv), which represents a thousandth of a sievert, and the microsievert (μSv), which represents a millionth of a sievert, are used for low doses. By way of example, the average annual natural radioactivity per person in France is 2.4 mSv, a chest x-ray represents about 0.1 mSv, and a round trip by air between Paris and New York is from 50 to 150 μSv. > Units of measurement
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2016 AREVA REFERENCE DOCUMENT
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