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Media center : Glossary

  • semiconductor

    to obtain electrical current in a solid, its free electrons must be able to move about. If there are many electrons in the conduction band, the material is a conductor. If the electrons are stationary, they remain in the valence band and the material is an insulator. The basic difference is that insulators have larger band, gaps and require more energy to free up electron flow. To mobilize the free electrons in semiconductors, heat, light, etc., is applied. This gives the electrons the energy they need to leap the band gap, passing from the valence band to the conduction band.

  • separation - transmutation

    the purpose of separation is to recover fission products and minor actinides. The latter are radioactive elements named after actinium, a heavy metal with relatively similar chemical properties. Transmutation occurs when the heavy nuclei of minor actinides are bombarded with neutrons and split, or fission, into lighter nuclei.

  • spot market

    an open daily market trading in raw materials and energy, as opposed to the medium and long-term contractual arrangements between governments. Rotterdam is the hydrocarbon spot trading marketplace.

  • superconducting inductance

    circulation of an electrical current in a "torus", a metal conductor wound around an inner tube-shaped structure. This assembly is cooled to below a certain critical temperature at which the conductor's resistance becomes practically zero. The current can then circulate for a theoretically infinite time.

  • superconductor

    material (alloy or metal) whose electrical resistance becomes practically zero below a certain temperature.

  • sustainable development

    the definition was given by the Brundtland Commission in 1987 and was used again at the Rio summit five years later "Development that satisfies the needs of the present without compromising the ability of future generations to satisfy their needs". Therefore this approach reconciles economic development, social equilibrium and respect of the environment.

  • Sv: SIEVERT (1 Sv = 1000 mSv)

    the biological effects of radiation on the exposed body are measured in sieverts. This is a radiation shielding unit. It is expressed as a dose equivalent and takes account of the radiation characteristics and the irradiated organ.

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True/False

Electric power plants using biomass do not release greenhouse gases