Areva - Reference Document 2016

GLOSSARIES 1. Technical glossary

> UO 2

powder

> Waste packaging Radioactive waste packaging: operation consisting of packaging waste in a form suited to radioactive materials containment, enabling its shipment, storage and final disposal. p Very low level radioactive waste such as vinyl or cleaning rags is packaged in drums, in special “big bags”, or in very large bins. Very low level radioactive rubble is placed loose inside special big bags. p Low level andmedium level waste is first reduced in volume as much as possible, then packaged in specific ways (immobilized or embedded in a special concrete, bitumen or resin matrix). The immobilizing or embedding matrix keeps the toxic and radiotoxic substances contained within the waste package. p High level waste is vitrified and poured into stainless steel canisters. > Wind tower Used to place the rotor at a sufficient height to reach higher wind velocities and facilitate its movement; in other words, to extract a much higher energy capacity. The tower houses certain electrical and electronic components, such as the air treatment system, the transformer station and the converter. > Wind turbine Device that converts kinetic energy from the wind into mechanical energy. This energy is usually converted into electrical energy. > Zircaloy Type 2 or 4 zirconium-based alloys containing tin, copper, iron and nickel. Other alloys, to which only niobiumor vanadiumare added, do not bear the name zircaloy. > Zirconium Metal chosen for its mechanical strength and corrosion resistance in high- temperature water, combined with its very low thermal neutron absorption, to make the alloy used in the cladding of light water reactor fuel elements. Zirconium is highly resistant to corrosion at high temperature. It is therefore used in the form of an alloy to fabricate nuclear fuel assemblies, including spacer grids, rods, guide tubes, etc. > Yellowcake (uranium concentrates) “Cakes” of about 80% uranium concentrates.

UO 2 is the symbol for uranium oxide. which comes in powder or pellet form. It is the constituent component of nuclear fuel. It is also the formula for pitchblende (natural uranium ore).

> Uraniferous material Material containing uranium.

> Uranium Uranium is a radioactive heavy metal. It is a chemical element with the atomic number 92 and the atomic symbol U, with three radioactive natural isotopes: 238 U (99.28% fertile), 235 U (0.71% fissile), and a very small quantity of 234 U. Uranium-234, which comes from the radioactive decay of uranium-238, is not fissile. > Uranium concentrate (yellowcake) Magnesium, sodium, ammoniumuranate or uraniumperoxide in solid form resulting from the mechanical and chemical treatment of uranium ore. This marketable concentrate contains about 80% uranium. > Used fuel storage pool Pools in which used fuel is stored for cooling after it is unloaded from a reactor. > Used nuclear fuel Fuel permanently removed from a reactor core after having been irradiated. > Vitrification Process used to incorporate concentrated solutions of final radioactive waste (fission products and minor actinides), which have been chemically separated from the used fuel, into a glass structure by mixing it with a glass matrix at high temperature.

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2016 AREVA REFERENCE DOCUMENT