Glossaire :Secondary containment structure [...] Sustainable development

Secondary containment structure (see the French definition ): The secondary containment structure is kept at negative pressure around a reservoir or tank and can contain any leak.
Secondary system (see the French definition ): A reactor in a nuclear power station has 3 circuits. The secondary system comes into operation when the heat that is captured by the primary circuit is transferred to the steam generator. The water then evaporates into steam which drives the turbine.
Sediments (see the French definition ): Particle deposits of varying sizes formed from the erosion of older rocks, residues of organic activity (e.g. mollusc shells, etc.) and chemical precipitation (some types of carbonates). Over time sediments are turned into sedimentary rock by natural compaction.
Seismic survey (see the French definition ): A seismic survey is a kind of underground ultrasound. Ground waves (vibrations) caused by an explosion or a mass falling on the ground are sent from a transmitter. These vibrations travel in all directions. When they reach a geological layer, some of the waves are reflected (as a mirror reflects light waves) and return towards the surface, while others are refracted and continue to go deeper into the ground, and so on. Analyzing the series of reflected waves is a way of recreating an underground image.
Seismograph (see the French definition ): A seismograph is used to make an accurate recording of the earth's movements. It is used to carry out vertical seismic profiles of a well.
Semi-conductor (see the French definition ): A semi-conductor is a material whose capacity to conduct electricity (conductivity), initially low, can rise depending on other factors such as temperature, luminosity, impurities, etc. The silicon used in the cells of photovoltaic panels is a semi-conductor: exposure to sunlight makes it a conductor of electricity.
Separation (see the French definition ): Separation is a refining technique which involves separating different types of products, from the heaviest to the lightest.
Seveso II (see the French definition ): “Seveso II” is a European Directive that was implemented in 1999. Its objective is to require the owners of facilities presenting industrial risks (classified as Seveso) to inform people of these risks. This duty is accompanied by national inspection programs.
Shale gas (see the French definition ): Shale gas is located in clayey sedimentary rocks buried deep underground which act both as the source rock and the reservoir for this gas. The low permeability of these rocks requires the adaptation of oil extraction techniques such as fracturing and horizontal wells.
Sievert (Sv) (see the French definition ): The unit of measurement for the effects of radioactive radiation on a living organism.
Solar panel (see the French definition ): A solar panel is a collection of photovoltaic cells connected by electric cables with an insulating plastic film which protects the cells in bad weather. The solar panel is the base unit of a solar power system: it captures the sun’s rays and converts them into electricity.
Solar photovoltaic energy (see the French definition ): Solar photovoltaic energy is produced by transforming sunlight into electricity.
Solar power tower (see the French definition ): In a solar power tower, swivelling reflectors are mounted close to the ground. They concentrate the energy released by the sun’s rays onto a boiler at the top of a tower.
Source rock (see the French definition ): The source rock is made up of a mixture of sediments and large quantities of organic matter that have settled on the sea bed over time. These residues remain intact for millions of years and gradually give way under the weight of the most recent sediments.
Spot market (see the French definition ): Spot markets are real international markets where traders buy and sell oil cargos. The cargos actually exist and are soon to be transported or already in transit.
Steam cracking (see the French definition ): Steam cracking is a refining technique which involves making hydrocarbons react with steam at high temperatures. This breaks down long molecules converting them into shorter ones.
Steam generator (see the French definition ): A steam generator converts water into steam. This drives a turbine to produce electricity. Steam generators are used in all kinds of thermal power plants, as well as in nuclear power plants (except in Boiling Water Reactors, where the steam is produced directly in the reactor core).
Stratigraphic trap (see the French definition ): Stratigraphic traps do not have a closed geometry. Migration is blocked by a horizontal variation in the quality of the reservoir which evolves into impermeable rock and therefore may lead to the formation of a hydrocarbon deposit.
Structural trap (see the French definition ): Structural traps are the most common. They have a closed geometry which is caused by deformed rocks. Anticline traps and fault traps are the most well-known kinds of structural trap.
Subsidence (see the French definition ): Over time the sediments that settle on the sea bed accumulate. Over millions and millions of years, these sediments gradually give way and are compressed under the weight of these accumulations. The gradual resulting subsidence leaves room for other sediments that continue to reach the sedimentary basin. This is what is known as subsidence.
Sustainable development (see the French definition ): This term was first defined in the 1987 Brundtland Report, where it is defined as “development which meets the needs of the present without compromising the ability of future generations to meet their own needs”.