AnadvancedseismicanalysisofanNPPpowerfulturbogeneratoronanisolationpedestalOriginalResearchArticle

Thispaperpresentsadetailedseismicanalysisofapowerfulhigh-speedRussianturbinewithinaNuclearPowerPlant.Althoughdozensoftheseturbineshaveworkedreliablysincethe1970sworldwide,untilthelastdecade,onlysimplifiedstructuralanalyseswereavailableduetotheturbines’complicatedoverallstructureandinternaldesign.Thecurrentanalysisconsidersthedetailedgeometryoftheturbineitselfandthevibrationandseismicisolationsystemwithintheturbineʹspedestalandthefullrangeofoperational,accidentandseismicloadslikehighpressure,outsideloadsinducedbypipelinesandsoon. Tosolvetheproblemoftheturbineseismicqualification,thefollowingstepshavebeentaken.Thefirststepwastocreatedetailedfiniteelementmodelsoftheturbineʹshighandlowpressurepartsandrotorsystemwithbearings.Usingsuchmodels,correspondingsimplifiedmodelsweredevelopedtobeincludedintothecoupledmodelofthesystem:“Building–VibroisolationPedestal–Turbine”(BVT).Thesecondstepwastheanalysisofthatcoupledsystem.Soil–structureinteractionwasconsideredusingactualsoilconditions.Threecomponentsoftimehistoryaccelerationwereusedtodefineseismicexcitation.AstheresultofBVTsystemanalysis,afullpictureoftimehistorydisplacementsandloadswasdetermined.Atthesametime,aproblemofrotorgapswassolved.Inthefinalstep,determinedloadswereappliedtothedetailedmodelsoftheturbineʹspartsforseismicqualificationofthewholestructure.