The Visual Dictionary of Science & Energy

99mud pitBasin that contains mud (a mixture of water, clay and chemical products) used mainly tocool and lubricate the bit and to remove debris.mud pumpDevice that circulates the mud in the drilling rig.engineDevice converting the combustion of fuel and air into mechanical energy.impervious rockLayer of impermeable rock that covers and protects the oil deposit; it prevents hydrocarbons frommigrating into other rocks.anticlineGeologic stratum that results from the convex folding of rock formations; large pools of oil oftenaccumulate in it.rotary systemDrilling device in which a kelly isattached to a rotary table; with the help ofpowerful motors, it transmits the rotativemovement to the kellys.kellySpecial square rod that is screwed to the top of the drill pipes and driven by the rotary table.rotary tableCircular table that is moved by powerful motors; it transmits its rotative movement to thedrill pipes by means of the kelly.oilGEOTHERMAL AND FOSSIL ENERGY

100derrickMetal structure erected over an oil well; tools for drilling through rock areraised and lowered through it.pontoonSubmerged floating caisson at the base of the hull column;seawater or oil are stored here to stabilize the platform.tubular memberSteel tube that connects the platform’s various hull columns to reinforce thestructure.anchor wiresThey anchor the pontoon securely to the ocean floor to ensure thestability of the platform.oil processing areaArea where crude oil is pretreated at the head of the well.helipadSite where helicopters land and take off.production/export riser systemVertical steel tubes that link the wellhead and the drilling platform; the system removes mud andoil.production platformFacility used to extract underwater oil deposits; theseparation and treatment of hydrocarbons are mainlydone here.oilGEOTHERMAL AND FOSSIL ENERGY

101flareDevice that draws off and burns in theair unmarketable gases collected in theseparator.oil/gas separatorDevice used to remove the gas from the crude oil from the well.radio mastMetal conductor used to send and receive radio waves; it provides communications mainly withcoastal stations and ships.lifeboatUnsinkable craft used to evacuate workers from the platform in an emergency.hull columnLarge steel tube that rises above the pontoon; it supports the production platformabove the surface of the water.craneMaterials-handling device fitted with arotating jib; a hook suspended from thejib is used to lift and move loads.gas lift moduleDevice used to introduce pressurized gas into the deposit to forceoil up in the well to increase production.oilGEOTHERMAL AND FOSSIL ENERGYChristmas treeGroup of devices at the head of the producing wellthat regulate the flow of oil being extracted fromthe deposit.manifoldAll the pipes and valves that carry crude oilfrom the well to preset points on theproduction platform.

102Christmas treeGroup of devices at the head of the producing well thatregulate the flow of oil being extracted from the deposit.master gate valveMain device that regulates the flow of oil; it cancompletely shut off the outflow.tubing headEquipment to which oil production and extractiontubes and devices (Christmas tree, tubing) areattached.tubingLast column of small steel tubes to be inserted in the well; theyare used to bring oil to the surface.casing first stringFirst column of large-diameter tubes that are inserted intothe producing well mainly to strengthen its walls.tubing valveDevice that regulates the flow of oilextracted from the well and carries it inflow lines, here toward an oil pipeline.pipelineSteel piping that carries oil from thewell to the refining facilities.flow beanCalibrated opening of a flow line through which oil flows;it is used to limit the flow from a producing well.pressure gaugeDevice that measures the oil pressure inside the producing well.oilGEOTHERMAL AND FOSSIL ENERGY

103oilGEOTHERMAL AND FOSSIL ENERGYpetrochemicalsChemical products derived frompetroleum-based products; they arefound in fertilizers, detergents, plasticsand other products.jet fuelAviation fuel used to power jet engines.stove oilFuel used mainly in home furnaces.gasolineMotor fuel that is used mainly by theautomotive industry to power internalcombustion engines.keroseneFuel used for lighting and heating.diesel oilFuel used mainly by the transportationindustry to power diesel engines.heating oilFuel used in home heating systemsand industrial installations requiringlittle energy.bunker oilFuel used in high-powered heatingsystems and electric power plants; it is alsoused to power large diesel engines.greasesPasty substances made of mineral oil and soap;they are used by industry to lubricatemechanical parts.lubricating oilsViscous substances that are usedmainly to reduce friction between twomoving surfaces.asphaltMixture of bitumen and othersubstances that is used mainly to paveroads.paraffinsWater-insoluble substances that have varioususes; these include candle making, packagingand pharmaceutical products.refinery productsRefining of crude oil yields hundreds of useful products.

104emergency support vesselFloating structure equipped with specialized equipment; itis used for rescue operations on drilling rigs.drill shipShip for drilling for oil in deep water (3,300 ft and more);it is more mobile but less stable than a semisubmersibleor jack-up platform.offshore drillingThere are various types of underwater oildrilling installations; the one used depends onthe location of the deposit and the depth of thewater.oilGEOTHERMAL AND FOSSIL ENERGYpierStructure that extends into the sea from aland-based installation; it is used for landdrilling extending offshore (about 10 ftdeep).

105jack-up platformMovable structure that is used in shallow water (between65 and 330 ft); it is raised above sea level on retractablepillars resting on the ocean floor.fixed platformStructure that is mainly used at moderatedepths (up to 1,300 ft); it rests on the seabedon pillars buried deep in the sea floor.oilGEOTHERMAL AND FOSSIL ENERGYsemisubmersible platformMovable structure that is anchored to the seabedand used at depths of 350 to 1,650 ft; it is mountedon pontoons submerged at about 100 ft to providestability.

106crude-oil pipelineContinuous underground, aboveground orunderwater oil pipeline that can be thousands ofmiles long (the Trans-Siberian pipeline is 3,800 milong).Christmas treeGroup of devices at the head of the producing well that regulate the flow of oil beingextracted from the deposit.refineryPlant in which crude oil is refined (separated and scrubbed) to obtain abroad range of finished products (including motor fuel and oils).terminalFacility located at the end of the pipeline that includes equipment such astanks and pumps; it receives the crude oil before it is refined.central pumping stationPowerful pumping station that maintains the pressure required to move the oil alongthe pipeline to the next pumping station.aboveground pipelineOil pipeline that rests on aboveground supports to protect it from frozen ground(e.g., the Alaska pipeline).buffer tankLarge container that stores crude oil temporarily before it is pumped back into thepipeline.offshore wellHole dug in the sea floor to extract oil deposits;equipment such as the Christmas tree rests on theseabed.derrickMetal structure erected over an oil well;tools for drilling through rock are raisedand lowered through it.oilGEOTHERMAL AND FOSSIL ENERGY

107production platformFacility used to extract underwater oildeposits; the separation and treatmentof hydrocarbons are mainly done here.submarine pipelinePipeline installed on the seabed that carries oil extracted from an underwater deposit to shore.pumping stationInstallation located at regular intervals along the pipeline that is fitted with motorized pumps; it ensuresthat the oil flows inside the pipeline.pipelineThe steel piping that carries oil from one treatment facility to another.intermediate booster stationBooster station that reinforces the action of the central station and maintains the flow ofoil in the pipeline network.tank farmAll the facilities (such as tanks and pumps) that store large quantities of crude oil to be sent later tothe refinery.oilGEOTHERMAL AND FOSSIL ENERGY

108fixed-roof tankFixed roof that keeps the tank sealed tightly; it is usedto store heavy products such as diesel fuel, keroseneand asphalt.bund wallCement wall around the tank thatprotects the environment in the event ofaccidental leakage.secondary inletSmall pipe through which liquids are introduced into the tank.automatic tank gaugeDevice used to measure the level of the liquid in the tank; the tank gaugefloat’s movement is transmitted to a magnet, which moves the hands on adial.tank gauge floatElement that floats on the surface of the stored liquid; it measures its level.breather valveMovable part that regulates the internal pressureof the tank; pressure fluctuates during emptyingand filling and with the temperature.spray nozzleDevice that sprays water onto the roofof the tank to cool it when thetemperature rises.main inletLarge pipe through which liquids are introduced into the tank.tanksLarge covered cylindrical containers that are usuallymade of steel; liquid or gaseous oil products are storedhere between the time they are refined and sold.oilGEOTHERMAL AND FOSSIL ENERGY

109laggingMaterial that covers the wall of the tank to keep it watertight and prevent corrosion.splash plateGutter used to collect water draining from the roof.manholeRound opening in the tank that is covered with a plate; workers can pass through it.spiral staircaseStaircase whose stairs wind around the wall of the tank to the roof.drain valveDevice for emptying the liquid from the tank.concrete drainSmall concrete trench used to drain off the productin the event of a spill or when the tank is emptied.manholeRound opening in the tank that is covered with a plate; workers can pass through it.manometerDevice that measures the pressure of the product inside the tank.oilGEOTHERMAL AND FOSSIL ENERGY

110manholeRound opening in the tank that is covered with a plate; workers canpass through it.floating roofMetal cover that rests on the surface of the storedliquid; it fluctuates with the level of the fluid andslides vertically inside the shell.shellVertical cylindrical wall of the tank.drain valveDevice for emptying the liquid from the tank.floating-roof tankTank whose floating roof rests directly on the surface of the liquid to minimizethe evaporation of hydrocarbons; it is used to store the most volatile products.oilGEOTHERMAL AND FOSSIL ENERGY

111sealing ringPart that fills the space between theroof and the shell to prevent anyhydrocarbons from evaporating andpolluting the atmosphere.top deckUpper part of the roof; the spacebetween the top and bottom decks isused to contain evaporatedhydrocarbons.ladderMovable device that consists of rungs(crossbars); it is used to climb up anddown.thermometerDevice that sets and controls thetemperature of the product inside thetank.filling inletOperation by which a liquid product isintroduced into the tank.bottom deckLower part of the roof; it rests directlyon the surface of the stored liquid.groundWire that connects the tank and its contentsto the ground to prevent static electricity fromaccumulating and avoid the risk of fire.stairsStructural element giving access to the roof of the tank.oilGEOTHERMAL AND FOSSIL ENERGY

112hydroelectric complexThe reservoir structures and installations that use water power to produce electricity.top of damUpper part of the dam; it rises abovethe water level of the reservoir byseveral yards.spillwayChannel that discharges excess water from thereservoir during flooding to avoid submerging thedam.log chuteStructure that allows floating wood to travelfrom upstream to downstream of the dam.spillway chuteInclined surface along which discharged water flowsout.training wallWall that separates the spillway chutes; it is used todirect the water flow.diversion tunnelUnderground conduit that diverts water duringconstruction.crest of spillwayCement crest over which the reservoir’s overflowdischarges when the spillway gates are opened.spillway gateMovable vertical panel; it is opened to allow thereservoir’s overflow to pass through.HYDROELECTRICITY

113hydroelectric complexpenstockChannel that carries water underpressure to the power plant’s turbines.headbayPart of the reservoir immediately in frontof the dam where the current originates.reservoirBasin formed by the construction of adam; it holds back a very large volume ofwater so that the flow rate can becontrolled.gantry craneHoisting device in the form of a bridge; itmoves along rails.control roomArea that contains the various controland monitoring devices required for theproduction of electricity.damBarrier built across a watercourse inorder to build up a supply of water foruse as an energy source.bushingDevice that allows the conductor to passthrough the wall of the transformer andseparates it from the latter.afterbayArea of the watercourse where water isdischarged after passing through theturbines.power plantPlant that uses an energy source, herewater, and converts it into electricity.machine hallArea that houses the generator units used to produceelectricity.HYDROELECTRICITY

114cross section of a hydroelectric power plantHydroelectric power plant: plant that produces electricityfrom energy generated by flowing water.gateMovable vertical panel that controls the volume of water in the penstock.gantry craneHoisting device in the form of a bridge;it moves along rails.transformerDevice used to alter the electric voltage; voltage is increased as the currentleaves the power plant so that it can be carried over long distances.circuit breakerMechanism automatically cutting off the power supply in the event ofoverload.busbarLarge aluminum conductor that transmits electric current from the alternatorto the transformer.penstockChannel that carries water under pressure to the power plant’s turbines.water intakeStructure that directs water from the headbay to the penstock to power theplant.reservoirBasin formed by the construction of a dam; it holds back a very large volumeof water so that the flow rate can be controlled.screenAssembly of bars placed in front of the water intake to hold back anythingthat could hinder the operation of the turbine.hydroelectric complexHYDROELECTRICITY

115bushingDevice that allows the conductor to passthrough the wall of the transformer andseparates it from the latter.lightning arresterDevice that protects the electric facilities from power surges caused by lightning.traveling craneHoisting device that travels along aboveground parallel rails; it is used to lift and carryheavy loads.machine hallArea that houses the generator units used to produceelectricity.access galleryUnderground passageway thatprovides access to various parts of thedam so that it can be inspected andmaintained.gantry craneHoisting device in the form of a bridge;it moves along rails.scroll caseDuct shaped like a spiral staircase thatis used to distribute water uniformlyaround the turbine to make it turnsmoothly.gateMovable vertical panel that controlsthe discharge of water to the tailrace.afterbayArea of the watercourse where water isdischarged after passing through theturbines.tailraceChannel that discharges water toward the afterbay inorder to return it to the watercourse.generator unitDevice with a turbine that transmits thewater’s mechanical energy to thegenerator’s rotor to make it turn toproduce electricity.draft tubeConduit at the base of the turbine thatincreases the runner’s output byreducing the pressure of the water as itexits.hydroelectric complexHYDROELECTRICITY

generator unitDevice with a turbine that transmits the water’s mechanical energy to the generator’s rotor to make it turn toproduce electricity.116wicket gateMovable panel that regulates the flowof water entering the turbine to ensurea constant rotational speed of therunner.rotorMovable part of the generator that is made up of electromagnets; its rotation induces an electric current inthe stator.thrust bearingUnit that bears the thrust of the turbine and the weight of the rotating parts of the generator unit.turbine headcoverStructure that covers the upper part of the turbine’s runner.spiral caseDuct shaped like a spiral staircase that is used todistribute water uniformly around the turbine tomake it turn smoothly.draft tubeConduit at the base of the turbine that increases the runner’soutput by reducing the pressure of the water as it exits.runnerMovable part of the turbine that transmits the movement ofthe water to the shaft to which it is attached to turn the rotor.hydraulic turbineMachine whose runner is powered by water; ittransmits mechanical energy to the rotor to makeit turn.HYDROELECTRICITY

117generator unitshaftCylindrical part that communicates themovement of the turbine’s runner to thegenerator’s rotor.stay ringSet of two rings linked together by thestay vanes.stay vane bladeFixed panel that receives pressurized water from the spiral case anddirects it over the wicket gates.exciterDevice that supplies electric current to the rotor’s electromagnets.gate operating ringMovable device that controls the opening and closing of the wicketgates.statorStationary part of the generator that consists of a coil of copperconductors, which collects the electric current produced by the rotor.draft tube linerCovering that is usually made of steel; it protects the draft tube from erosion.runner bladeStationary curved plate on the turbine’s runner; it receives the thrustof the water to turn the runner.generatorMachine that consists of a rotor and a stator; it produces an electriccurrent.bottom ringCircular part under the wicket gates that holds them in place.HYDROELECTRICITY

118Francis runnerMost common type of runner that is suited to average heights ofwater (usually between 100 and 1,000 ft).ringCircular part that supports the wicketgates.bladeStationary curved plate on the turbine’srunner; it receives the thrust of thewater to turn the runner.Kaplan runnerType of runner that is suited to lowheights of water (usually between30 and 200 ft) and variable flow rates.hubPart of the runner that holds the shaft;the runner blades are attached to it.Pelton runnerType of runner that is suited to highwater sources (usually over 1,000 ft)and low flow rates.hub coverCover for the lower cone-shaped partof the hub.bucketSmall bucket that is attached to theturbine’s runner; water enters it to turnthe wheel.bucket ringDisk housing all the turbine buckets that activates the runner.coupling boltElement made up of a nut and a boltthat attaches the runner to the shaftplate to transmit its movement to therunner.runner bladeMovable part that is fixed to the hub ofthe runner; it turns through the actionof water power on it.runnersMovable parts of the turbine that transmit the movement of the water to theshaft to which they are attached to turn the rotor.generator unitHYDROELECTRICITY

119buttress damUsed mainly in wide valleys, it consists of an impermeable wall, which isshored up by a series of buttresses to transmit the thrust of the water to thefoundation.cross section of a buttress dambuttressBlock of concrete reinforcing a wall that has to stand up tothe thrust of the water; it provides stability to the dam.foundation blockageBlock of concrete that anchors the foundation in the ground to preventmovement.foundationConcrete structure that supports theweight of the dam and transmits it tothe ground to provide stability to thedam.reservoirBasin formed by the construction of adam; it holds back a very large volumeof water so that the flow rate can becontrolled.examples of damsThere are masonry dams, concrete dams and embankment dams; the choice depends on criteria such as thenature of the ground, the shape of the valley and the materials available.HYDROELECTRICITY

120embankment damFormed of mounds of earth or rocks, it isused mainly when the subsoil does notallow for construction of a concrete dam.cross section of an embankment damtop of damUpper part of the dam; it rises abovethe water level of the reservoir byseveral yards.clay coreCentral portion of the dam that is usuallymade of compact clay to make it watertight.pitchingLayer of rock or concrete blocks thatcovers the upstream shoulder to preventerosion.wave wallSmall wall located at the top of the upstream shoulder thatprotects the dam against waves.reservoirBasin formed by the construction of adam; it holds back a very large volume ofwater so that the flow rate can becontrolled.upstream toeArea where the upstream shoulder and thefoundation of the dam meet.upstream shoulderSoil embankment located on the reservoir side; its mass Area of the foundation of the dam that isprovides stability to the dam.upstream blanketImpermeable layer that consists ofcompact clay; it rests on the bottom of thedam to prevent infiltration.cut-off trenchconnected to the core; it containsimpermeable materials to limit leakageand infiltration under the dam.sandGranular material that is inserted betweenthe core and the shoulder; it filters particlescarried by the water flow to prevent erosion.examples of damsHYDROELECTRICITY

121bermHorizontal ledge that stabilizes theupstream or downstream shoulder.downstream toeArea where the downstream shoulderand the foundation of the dam meet.drainage blanketLayer of permeable materials on the foundation of the dam; it collectsinfiltrated water and prevents erosion of the base of the dam.downstream shoulderSoil embankment that, together with the upstream shoulder, provides stability to the structure.foundation of damNatural terrain (such as rock, sand or clay) on which the dam is built.drainage layerLayer of permeable materials that is inserted into large-scale dams to collect infiltrated water.examples of damsHYDROELECTRICITY

122cross section of an arch damcantileverImaginary vertical element that is used to calculate the arch dam (usually by breaking itdown into horizontal arches and vertical cantilever elements).peripheral jointMaterial that fills the space between the dam and the pulvino over the entire lengthof the structure; it allows the structure to transmit the thrust of the water to its lateralsupports.afterbayArea of the watercourse where water isdischarged after passing through theturbines.soilNatural rocky ground in which the dam isanchored.reservoirBasin formed by the construction of a dam; it holds back a very large volume of waterso that the flow rate can be controlled.arch damIts curvature allows most of the water’s thrustto be transmitted to the usually narrow valleyslopes supporting it.pulvinoSupporting mass of the dam foundation that bears its weight and transmits it tothe ground.examples of damsHYDROELECTRICITY

123cross section of a gravity damtop of damUpper part of the dam that usuallycontains a roadway.upstream faceDam face on the reservoir side.downstream faceUsually sloping dam face on the afterbay side.afterbayArea of the watercourse where water isdischarged after passing through theturbines.reservoirBasin formed by the construction of adam; it holds back a very large volumeof water so that the flow rate can becontrolled.gravity damIts huge mass resists the thrust of the waterto prevent it from overturning or sliding; thistype of dam is usually used to hold backlarge volumes of water.cut-off trenchWatertight structure that extends the foundations of the dam into theground; it limits leakage and infiltration under the dam.examples of damsHYDROELECTRICITY

rotation of the turbineFlowing water applies pressure to theturbine’s blades to make it turn.transformation of mechanical work into electricityThe generator converts water power into electricity.124supply of waterBasin created by building a dam,which holds back a large volume ofwater.energy transmission at the generator voltageElectric power produced by the generator is transmitted to a transformer at the power plantoutlet.voltage increaseAt the outlet end of the power plant, the transformer increases the voltage; this reducesenergy losses during transmission over long distances.production of electricity by the generatorThe generator produces electricity through the movementof the rotor in the stator.water under pressureThe water takes on energy as it flowsdown the penstock and is carriedwith force to the turbine.head of waterThe dam raises the water level tocreate a vertical drop along the lengthof the penstock.steps in production of electricityIn a hydroelectric power plant, water is turned into electricity, which is carried to consumers along atransportation and distribution network.HYDROELECTRICITY

125energy integration to the transmission networkThe electricity produced is integrated into the network.high-tension electricity transmissionUsing high-voltage lines to transmit electricity over long distances reduces thestrength of the current and, as a result, energy losses.voltage decreaseBefore integrating the electricity into the distribution network, the voltage is progressively decreasedto 240 V.transmission to consumersThe electricity is carried to areas of consumption by low-voltagedistribution lines.steps in production of electricityHYDROELECTRICITY

126overhead connectionThe equipment and overhead conductorsthat connect a subscriber’s electric systemto the public distribution network.bushingInsulator and point where the current enters the medium-tension transformer.low-tension distribution lineOverhead line that distributes electricity up to avoltage of 750 V; its conductors are located underthe transformer.supply pointPlace where the customer’s serviceentrance is connected to the low-tension distribution line.insulatorPiece of nonconducting material thatconnects the distribution line conductorsto the support.transformerDevice that alters electric voltage; voltage is decreased before being distributedby low-tension lines to areas of consumption.terminalPart on which low-tension distributionline conductors are joined to thetransformers.electricity transmissionElectricity is carried by overhead and underground lines; due to high cost, underground lines are used mainly in cities.HYDROELECTRICITY

127insulatorPiece of nonconducting material thatconnects the distribution lineconductors to the support.hot line connectorLinking piece with a bolt, which is tightened to bring togethertwo conductors to establish an electric connection betweenthem.medium-tension distribution lineOverhead line that distributes electricity at a voltage between 750 and50,000 V; its conductors are located at the top of electricity poles.crossarmHorizontal element located at the top ofan electricity pole; insulators areattached to it.lightning arresterDevice that protects the electric facilities frompower surges caused by lightning.fuse holderElectric junction point where the fuse is attached and on which it articulates so the fuse can fallover.fuse cutoutUnit that consists of a fuse and a fuseholder.fuseProtection device for the electric circuit; itfalls from the fuse holder to cut the currentin the event of a surge.braceSlanted part that connects the pole to the crossarm tohold it in place horizontally.electricity transmissionHYDROELECTRICITY

128pylonMetal beam that supports the electric conductorsalong the overhead transportation lines.overhead ground wireConductor that is connected to the ground andattached above the bundles of the overhead lines of the pylon; it supports the bundles by means ofto protect them from lightning.pylon topUpper portion of the pylon where theinsulator strings and bundles areattached.pylon bodyPart of the pylon support between thetop and the foot.pylon footLower part of the pylon that is usuallyunderground; the legs are anchored toit.main legThe main tower legs of the pylon body;they support mainly vertical weights.horizontal memberHorizontal bar that connects the mainlegs to strengthen them.panelPart of the pylon between twohorizontal members.bundleConductor cables that are kept aconstant distance apart by spacers;they are used to transport current.suspension insulator stringInsulators that are assembled in avertical or oblique chain; the overheadline conductors hang from it.crossarmHorizontal element that protrudes on each sidesuspension insulator strings.electricity transmissionHYDROELECTRICITY

129network connectionSet of equipment and conductors allowing a customer’s electric installation to be connectedto the public grid.electricity transmissionconnection pointPlace where the customer’s electrichookup is connected to the electricgrid.medium-tension distribution lineOverhead electricity-distribution lines with tensionbetween 750 and 50,000 volts; its conductors arelocated at the top of the poles.low-tension distribution lineOverhead electricity-distribution line with a maximumtension of 750 volts; its conductors are located underthe transformer.ground wireMetal conductor inserted into the groundensuring that accidental electricleakages are conducted to the earth.electricity meter main switchDevice measuring the consumption of electricity by a dwelling. Mechanism allowing a dwelling’s current tobe cut off.distribution panelSet of devices forming the junction ofthe public electricity grid and theelectric circuits of a dwelling.HYDROELECTRICITY

130tidal power plantPlant that harnesses tidal power (the motion of the rising and falling tides) to produce electric power.seaVast body of saltwater at some distanceinland; it is not as deep as an ocean.lockStructure with doors and gates that is builtbetween the sea and the basin; it allowsboats to pass from one level to the other.power plantPart of the dam housing bulb units that arepowered by the rise and fall of the sea toproduce electricity.administrative buildingsubstationThe devices (such as transformers andchangeover switches) that increase thevoltage of the electricity and carry it to thenetwork.HYDROELECTRICITY

131tidal power plantoperating damStructure with gates that control the basinlevel in relation to the level of the sea.bankStrip of land bordering the sea.inactive dikePart of the dam made up mainly of rockymaterial; it is built between the plant and theoperating dam to separate the basin from thesea.basinArea in which water is stored at high tide; thebasin empties out through the penstocks atlow tide.gateMovable vertical panel that controls the rateof flow of the water between the sea and thebasin.HYDROELECTRICITY

132cross section of a power plantsea sideAt high tide, the sea is higher than thebasin and it fills up; at low tide, the actionis reversed.access shaftVertical shaft connecting the operatingfloor to the generator so that inspectionand maintenance can be carried out.bulb unitA turbine is connected by a horizontal axis to the rotor of a generator unit, which turnsunder the action of the tide.runner bladeMovable part that is fixed to the hub ofthe runner; it turns through the actionof water power on it.turbine runnerMovable part of the turbine that converts energy from the water it receives into mechanical energy, which is transmitted to thegenerator’s rotor.operating floorPart of the plant that houses the equipment needed to operate thebulb units (including maintenance and control devices).tidal power plantHYDROELECTRICITY

133penstockChannel that carries water to the plant turbines,from the sea to the basin or from the basin to thesea.top of damUpper part of the plant; it usually has an access road.basin sideAt low tide, the sea is lower than the basin and it emptiesout; at high tide, the action is reversed.tidal power plantHYDROELECTRICITY

134production of electricity from nuclear energyA nuclear fission chain reaction is started and controlled inside the reactor to produce electricity.moderatorSubstance (ordinary water, heavy water,graphite) that slows the fast-moving neutronsemitted during fission to increase theprobability of new collisions.fuelMatter placed in the core of the reactorthat contains heavy atoms (uranium,plutonium); energy is extracted from itby fission.sprinklersDevices that release water to condense radioactive steam.dousing water tankVat that contains water to cool the radioactive steam in the reactor in theevent of an accident; this prevents a rise in pressure.containment buildingConcrete building used to collect theradioactive steam from the reactor inthe event of an accident.NUCLEAR ENERGYcoolantLiquid or gas (including heavy water andcarbon dioxide) that circulates inside thereactor; it harnesses and transports the heatreleased during fission of the fuel.

135heat productionThe fission of atoms releases intenseheat (between 575°F and 925°F),which is transmitted to the coolant.fission of uranium fuelThe nuclei of the atoms break up; this freesneutrons and releases energy in the form of heat.safety valveDevice that lowers the pressure inside thereactor by discharging the radioactive steamto the containment building.reactorTightly sealed area where fission of the fuel iscarried out in a controlled manner to release heat.water turns into steamThe hot coolant heats the water of the generatorand brings it to the boiling point.hot coolantThe coolant extracts heat from the fuel and carries ittoward the steam generator.transfer of heat to waterThe coolant releases the heat given off by the fission of uranium to the steam generator.cold coolantAfter releasing its heat to the steam generator, the cold coolant returns to the reactor.production of electricity from nuclear energyNUCLEAR ENERGY

136steam pressure drives turbineSteam from the steam generator turns the turbine runner, which is connected to the generator.condensation of steam into waterAt the turbine outlet, the steam cools andcondenses into water.water cools the used steamCooling of the steam from the turbine is done with river or lake water.water is pumped back into the steam generatorAfter passing through the turbine, water produced by the condensation of thesteam returns to the steam generator.turbine shaft turns generatorThe rotational movement of the turbine is transmitted to the generator’s rotor.NUCLEAR ENERGYproduction of electricity from nuclear energy

137voltage increaseAt the outlet end of the power plant, the transformerincreases the voltage; this reduces energy lossesduring transmission over long distances.electricity transmissionUsing high-voltage lines to transmit electricityover long distances reduces the strength of thecurrent and, as a result, energy losses.production of electricity by the generatorThe generator produces electricity through the movement of the rotor in thestator.production of electricity from nuclear energyNUCLEAR ENERGY

138loading areaArea of the reactor building where new fuel is stored before beingused.fueling machineRemote-controlled device that inserts new fuel into thereactor.portTube used to insert fuel into the fueling machine.reactorTightly sealed area where fission of the fuel is carried out ina controlled manner to release heat.spent fuel portTube used to reclaim spent fuel from the accept machine.elevatorMechanical device used to put spentfuel into the discharge bay.discharge bayWater-filled basin that receives spent fuel as it exits the accept machine; the water acts as a protective barrier againstthe radiation emitted by the fuel.failed fuel canningFailed fuel bundles are covered with a watertight casing.accept machineRemote-controlled cylinder that removes the spent fuelfrom the reactor and carries it to the discharge bay.transfer canalWater-filled channel used to transferthe spent fuel mechanically from thereactor building to the service buildingfor storage.fuel handling sequenceUranium is made into pellets, which are pressed into fuel bundles to be used in the reactor and then stored incooling bays.NUCLEAR ENERGY

139storage trayTray on which spent fuel is stacked.service buildingEnclosure that contains the plant’sauxiliary systems such as storage and fueldecontamination equipment.new fuel storage roomEnclosure where new fuel is stored before being introducedinto the reactor building.equipment lockArea through which equipment and fuel pass between the service building and thereactor building.spent fuel storage bayWater-filled basin where the spent fuel is stored for several yearsbefore it can be disposed of safely.failed fuel bayWater-filled basin in which failed fuel is stored.canned failed fuelFailed fuel bundles are stored in a water-filled basin.reception bayWater-filled basin into which spent fuel from the dischargebay is carried.fuel handling sequenceNUCLEAR ENERGY

140pencilWatertight metal cladding in which fuel pelletsare loaded.fuel pelletSmall quantity of fuel that consists of powder pressed into asheathing tube and then inserted into the metal cladding of thepencil.end capCylindrical part soldered to the ends of Metal grille that is soldered to the ends of the pencils to keep them in place.the cladding of the pencil to make itwatertight.end plateMetal grille that is soldered to the endsof the pencils to keep them in place.pressure tubeTube that holds the fuel bundles and circulates thecoolant at a preset pressure.spacerPart that is soldered to the cladding ofthe pencils to maintain a presetdistance between them.pencilWatertight metal cladding in which fuel pellets are loaded.bearing padMetal part that is soldered to the pencils around the circumference of the bundle; it is used as a supportsurface as they are introduced into the pressure tube.end platefuel bundleFuel pencils that are grouped in parallel for introduction into the reactor.NUCLEAR ENERGY

141fuel pelletSmall quantity of fuel that consists of powder pressed into a sheathing tube and then inserted intothe metal cladding of the pencil.fuel bundleFuel pencils that are grouped in parallel for introduction into the reactor.containment buildingConcrete structure surrounding thereactor vessel; it is a protective barrieragainst radioactivity.spent fuel storage bayWater-filled basin where the spent fuel is stored for several years before it canbe disposed of safely.reactor vesselThe core of the nuclear reactor consists oftubular spaces where fission is produced andthe coolant and moderator circulate.pressure tubeTube that holds the fuel bundles andcirculates the coolant at a presetpressure.reactor buildingConcrete structure surrounding the reactorvessel; it is a protective barrier againstradioactivity.nuclear reactorTightly sealed area where fission of the fuel is carried out in a controlled manner to release heat.NUCLEAR ENERGY

142nuclear generating stationPlant that produces electricity from thermal energy generated by the fission of fuel atoms in a reactor.spent fuel discharge bayWater-filled basin that receives spent fuel as it exits the acceptmachine; the water acts as a protective barrier against the radiationemitted by the fuel.generatorTurbine-powered rotating machine that converts mechanical energy intoelectric energy to direct it toward a transmission network.turbineMachine in two sections whose steam-activated runner transmits mechanical energy tothe rotor shaft of the generator.transformerDevice used to alter the electric voltage; thevoltage is increased at the station outlet in orderto carry the current over long distances.condenserWater collected from the water table flows in acircuit to cool the steam from the turbine andcondense it into water.low-pressure steam inletHeated steam is reinjected into the turbine,where it releases its remaining energy.condenser water outletWater in the condenser returns to its originalsource.reheaterDevice used to increase thetemperature of the steam from thefirst section of the turbine to reinjectit into the second section.separatorDevice that removes any water from thesteam to prevent damage to theturbine’s runner.high-pressure steam inletSteam from the steam generators is carried to the first section of theturbine; here, it cools down and loses some of its energy.main steam headerDevice that collects and disperses steam from thesteam generators.NUCLEAR ENERGY

143nuclear generating stationspent fuel storage bayWater-filled basin where the spent fuel is stored for several years before itcan be disposed of safely.reactor building airlockSecure area where equipment and personnel can pass safely through thereactor building.control roomArea that houses the personnel and equipment used to operate andmonitor the power station.fueling machineRemote-controlled cylinder used to load andunload the reactor.calandriaSafety containment wall that separates the reactor from the rest of the building.reactorTightly sealed area where fission of the fuelis carried out in a controlled manner torelease heat.feeder headerLarge-diameter pipe that collects the coolant fluid at the reactor inlet andoutlet.heat transport pumpApparatus that circulates the coolant fluid between the reactor and thesteam generator.reactor buildingConcrete structure surrounding the reactor vessel; it is a protectivebarrier against radioactivity.dousing water tankVat that contains water to cool the radioactive steam in the reactor in theevent of an accident; this prevents a rise in pressure.steam generatorApparatus that turns water into steam, which in turn activates the turbine.NUCLEAR ENERGY

144carbon dioxide reactorDeveloped for the most part in Great Britain and France, it was replaced by the pressurized water reactor, whichperforms better and is less expensive.fueling machineRemote-controlled device that inserts new fuel into the reactor.concrete shieldingConcrete structure that holds back radioactive products in the event of anaccident.heat exchangerTubing system that is submerged in the hot carbon dioxide; here, water is turnedinto steam to power the turbine.steam outletWater that has been vaporized in the carbon dioxide is carried to the turbine toproduce electricity.feedwaterPiping carries water from the condenser to the heat exchanger, where it isturned into steam.carbon dioxide gas coolantCarbon dioxide that recovers the heat from the reactor core and transfers it to theheat exchanger.NUCLEAR ENERGY

145carbon dioxide reactorcontrol rodTube that contains a neutron-absorbingmaterial (boron, cadmium) that isintroduced into the reactor core to controlits power.reactor coreCenter section of the nuclear reactor wherefission reactions take place.blowerDevice that circulates carbon dioxide in the reactorcore.fuel: natural uraniumNatural uranium: fuel extracted from mines; itconsists of a mixture of three uranium isotopes(uranium-234, -235 and -238).moderator: graphiteModerator: medium that slows the speed of theneutrons to maintain a continuous chain reaction.coolant: carbon dioxideCarbon dioxide: gas that is heavier than air and isproduced by burning graphite.NUCLEAR ENERGY

146heavy-water reactorThe advantage of this type of reactor is that it does not require fuel enrichment; it is used mainly in Canada,Argentina and India.fuelMatter that is placed in the reactorcore; it contains heavy atoms(uranium, plutonium) from whichpower is extracted by fission.control rodTube that contains a neutron-absorbingmaterial (boron, cadmium) that isintroduced into the reactor core to controlits power.concrete shieldingConcrete structure that holds backradioactive products in the event of anaccident.fuel: natural uraniumNatural uranium: fuel extracted from mines; itconsists of a mixture of three uranium isotopes(uranium-234, -235 and -238).coolant: pressurized heavy waterHeavy water is kept at a set pressure to prevent itfrom boiling.moderator: heavy waterHeavy water: water consisting of heavy hydrogen(deuterium) and oxygen; it can slow down neutrons.NUCLEAR ENERGY

147heavy-water reactormoderator tankSteel tank that contains cold heavy water from the moderator.cold heavy waterA pumping system ensures that heavy water around the moderator tankcirculates, cools and is purified.safety tankTank where cold heavy water from the moderator flows to stop fission reactions inthe event of an emergency.pumpApparatus that circulates the coolant fluid between the reactor and the steamgenerator.fueling machineRemote-controlled device that inserts new fuel into the reactor.feedwaterPiping carries water from the condenser to the steam generator, where it is turnedinto steam.steam outletSteam from the generator is carried to the turbine and generator to produceelectricity.pressurizerDevice that keeps the coolant water at apreset temperature to prevent it fromboiling.steam generatorDevice that uses heat from the coolant to turn water into steam to activate theturbine.pressurized heavy waterHeavy water that is heated in the reactor core is kept under pressure to prevent itfrom boiling.NUCLEAR ENERGY

148pressurized-water reactorThe most common type of reactor in the world; water from the coolant is kept under heavy pressure to prevent itfrom vaporizing.pressurizerDevice that keeps the coolant water at a preset temperature toprevent it from boiling.control rodTube that contains a neutron-absorbing material (boron,cadmium) that is introduced into the reactor core to control itspower.reactor coreCenter section of the nuclear reactor where fission reactionstake place.pumpApparatus that circulates the coolant fluid between the reactorand the steam generator.NUCLEAR ENERGY