Areva - Reference Document 2016

GLOSSARIES 1. Technical glossary

> Dosimeter The instrument for measuring radioactive doses received by an individual, or by certain of that individual’s organs (passive or operational dosimetry), or by the environment (site dosimetry). > Ecodesign Design of a product or an industrial installation that helps reduce the consumption of natural resources and limit releases likely to impact the environment. > Electrolyzer Electrochemical system (energy receptor) in which liquid water is separated into oxygen and hydrogen by an electrical current that passes between two electrodes. The ions produced by the oxidation-reduction reactions flow freely from one electrode to the other. The two electrodes (cathode: reduction reaction; anode: oxidation reaction) are linked by the electrolyte and the electric current generator. In the alkaline electrolyzer, the electrolyte is a potash solution that circulates or is immobilized in a retention matrix; in the membrane electrolyzer, the electrolyte is in the form of a proton conduction ion exchange membrane. > End-of-lifecycle operations All of the regulatory obligations for shutting down and dismantling nuclear facilities and managing radioactive waste. > Enriched uranium, depleted uranium Before it is used to fabricate fuel elements for reactor systems moderated and cooled with ordinary water, natural uranium is enriched in 235 U to a concentration of 3-5%. Natural uranium is used to produce uranium enriched in 235 U. The physical or chemical processes used to enrich uranium also produce uranium that has a lower concentration of 235 U than natural uranium (0.2 to 0.4%): this is known as depleted uranium. > Enrichment Process used to increase the abundance of fissile isotopes in a chemical element. Naturally occurring uranium essentially consists of 0.7% 235 U (fissile isotope) and 99.3% 238 U (non-fissile isotope), and must be enriched in 235 U for it to be used in a pressurized water reactor. The proportion of 235 U is brought to around 3 to 5%. > Environmentally regulated facility Installations and operations “listed in the nomenclature of regulated facilities that may represent hazards or drawbacks, whether for the convenience of the surrounding area, for health and safety, for agriculture, for the protection of nature, the environment and the countryside, or for the preservation of sites andmonuments as well aspects of an archeological nature.” > Environmental Management System (EMS) Part of the overall management system, which includes the organizational structure, planning activities, responsibilities, practices, procedures, processes and resources to develop, implement, carry out and maintain the environmental policy. > EPR reactor Generation III+ pressurized water reactor (PWR). It generates 1,650MWe of electric power and features a greater level of safety than generations II and III reactors and simplified operations and maintenance. It also has a projected service life of 60 years, compared with an initial service life of about 40 years for the reactors currently in operation around the world.

> ERU Fuel made with recycled uranium.

> Euratom Treaty signed in Rome on March 25, 1957, together with the treaty that founded the European Economic Community (EEC). It institutes the European Atomic Energy Community, which aims to establish “the conditions necessary for the formation and rapid growth of nuclear industries.” Its mission consists of contributing, through the development of nuclear energy, to the sharing of knowledge, infrastructure and financing and to ensuring the security of supply within the framework of centralized control. It brings together the 28 member states of the European Union. > Exposure Exposure of an organ or an organism to a source of radiation, characterized by the dose received. > Fertile Said of a nuclide that can be converted into a fissile nuclide via capture of a neutron, possibly followed by a series of disintegrations. > Final radioactive waste Radioactive waste that can no longer be treated, in particular by extracting its reusable content, under current technical and economic conditions. > Fissile Describes a nuclide capable of undergoing fission; the fission of atoms gives rise to several neutrons. > Fission The spontaneous or forced splitting of a heavy nucleus – generally after absorption of a neutron – into two or three smaller nuclei, or fission products, accompanied by the emission of neutrons and radiation and the release of a considerable amount of heat. The substantial energy released is the principle underlying nuclear power generation. > Fission products Fragments of heavy nuclei produced during nuclear fission or the subsequent radioactive decay of nuclides formed during that process. These fission fragments and their decay products are collectively referred to as “fission products”. > Fuel cell Electrochemical system that converts the chemical energy of the oxidation reaction of a fuel directly into electrical energy. In its simplest form, a fuel cell consists of two electrodes (anode and cathode) and is powered with oxidation-reduction couples likely to achieve a balance with the ions contained in the electrolyte. The oxidant in the fuel cells is either pure oxygen or the oxygen in air. The most commonly used reducing agents are gaseous (hydrogen or methanol), liquid (hydrocarbons or methanol) or solid (zinc, aluminum, etc.). Unlike accumulators, whose energy is dependent on the active matter incorporated into the electrodes, a fuel cell uses reactive chemical species froman external source (outside the cell), and the species formed are constantly eliminated, theoretically ensuring continuous operation.

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2016 AREVA REFERENCE DOCUMENT