ML17261B015

Responds to Generic Ltr 89-19, Safety Implication of Control Sys in LWR Nuclear Plants (USI A-47). Overfill Protection Provided Through Trip Bistables in Reactor Protection Racks Powered from 120-volt Instrument Buses

ML17261B015
Person / Time
Site:	Ginna
Issue date:	03/19/1990
From:	MECREDY R C ROCHESTER GAS & ELECTRIC CORP.
To:	JOHNSON A R Office of Nuclear Reactor Regulation
References
REF-GTECI-A-47, REF-GTECI-SY, TASK-A-47, TASK-OR GL-89-19, NUDOCS 9003270120
Download: ML17261B015 (6)

Text

ACCELERATEDDISTBJBUTIONDEMONSTPA,TIONSYSHMIIREGULATORY-.INFORMATIONDISTRIBUTIONSYSTEM(RIDS)ACCESSION,,NBR:9003270120DOC.DATE:90/03/19NOTARIZED:YESFACIL:50-244RobertEmmetGinnaNuclearPlant,Unit1,RochesterAUTH.NAMEAUTHORAFFILIATIONMECREDY,R.C.RochesterGas6ElectricCorp.RECIP.NAMERECIPIENTAFFILIATIONJOHNSON,A.R.ProjectDirectorateI-3DOCKETG05000244R

SUBJECT:

RespondstoGenericLtr89-19,"SafetyImplicationofControlSysinLWRNuclearPlants."DISTRIBUTIONCODEA001DCOPIESRECEIVED:LTRENCLSIZE:TITLE:ORSubmittal:GeneralDistributionNOTES:LicenseExpdateinaccordancewith10CFR2,2.109(9/19/72).DS05000244RECIPIENTIDCODE/NAMEPD1-3LAJOHNSON,AINTERNAL:NRR/DET/ECMB9HNRR/DST8E2NRR/DST/SICB7ENUDOCS-ABSTRACTOGC/HDS2RES/DSIR/EIBEXTERNAL:LPDRNSICCOPIESLTTRENCL115511111111~.10111111RECIPIENTIDCODE/NAMEPD1-3PDNRR/DOEA/OTSB11NRR/DST/SELB8DNRR/DST/SRXB8E0NRCPDRCOPIESLTTRENCL11111111101111DD'DNOTETOALL"RIDS"RECIPIENTS:ADDPLEASEHELPUSTOREDUCEWASTEICONTACTTHE.DOCUMENTCONTROLDESK,ROOMPI-37(EXT.20079)TOELIMINATEYOURNAMEFROMDISIRIBUTIONLISTSFORDOCUMENTSYOUDON'TNEEDITOTALNUMBEROFCOPIESREQUIRED:LTTR21ENCL19 I'lÃlllll/f/EIFIEEIaI(hlaROCHESTERGASANDELECTRICCORPORATIONo89EASTAVENUE,ROCHESTER,NY.14649.0001March19,1990TELEPHONEAREACOOE715546.2700U.S.NuclearRegulatoryCommissionDocumentControlDeskAttn:Allen"R.JohnsonProjectDirectorateI-3Washington,D.C.20555

Subject:

GenericLetter89-19,"SafetyImplicationofControlSysteminLWRNuclearPowerPlants"(USIA-47)R.E.GinnaNuclearPowerPlantDocketNo.50-244

DearMr.Johnson:

GenericLetter89-19requiredlicenseestorespondwithin180daysoftheGenericLetterdetailingwhethertherecommendationsoftheletterwillbeimplementedandanimplementationscheduleifapplicable.TheGenericLetteraddressesconcernsabout.SteamGenerator(SG)overfillprotection.AtGinna,overfillprotectionisinitiatedonaSGhigh-water-levelsignalbasedona2-out-of-3initiatinglogi'c.Thisinstrumentationissafetygradebutoneofthethreechannelsisusedforbothcontrolandprotection.ThesystemisolatesMainFeedwater(MFW)byclosingthemainfeedwater.controlandbypassvalves.IntermsofUSIA-47,thisdesignisconcludedtobeacceptableif:A)TheFeedwaterControlSystemisnotpoweredfromthesamesourceasoverfillprotection.B)Overfillprotectionandfeedwatercontrolarenotlocatedwithinthesamecabinets.C)Overfillprotectionandfeedwatercontrolsignalsareroutedsuchthatafireisnotlikelytoaffectbothsystems.D)Plantproceduresand.TechnicalSpecificationsincluderequirementstoperiodicallyverifyoperabilityofoverfillprotection.ThefollowingaddresseachcriterioninthecontextoftheGinnadesign:5'003270i209003i9PDRADOCK05000244PDC001MjA)py4o$5~P Overfillprotectionisprovidedthroughtripbistablesinthereactorprotectionracks,whicharepoweredfromA,B,CandD120VACinstrumentbuses.Uponbistableactuation,the120VACprotectionrelays(normallypowered.bythebistable)arede-energized,andtherelaycontacts(configuredina2-out-of-3matrix)open,de-energizingtheventsolenoidsfromTrainAandTrainB125VDCpower,resultinginclosureofthemainfeedwatercontrolandbypassvalves.TheFeedwaterControlSystemreceivespowerfromtheAandC120VACinstrumentbuses.Separate-breakersareusedtoprovidepowertotheprotectionracksandthefeedwatercontrolsystemexceptFeedwaterLoopAandLevelLoop461shareacommoninstrumentBusAbreakerandacommonregulator(TWINCO-MQ400A).FailureofthecommonbreakerorregulatorwouldcausealossofLoopAfeedwatercontroland.makeupoftheLT-461portionofoverfillprotectionlogic.LossofanyotherbreakerorregulatorwouldonlyaffectitsassociatedlevelchannelorFeedwaterControlLoopB.Sinceoverfillprotectionisfailsafe,actuationofoverfillprotectionwillventthefeedwatercontrolvalvethusoverridinganyactionsoftheControlSystem.Thedesignofoverfillprotectionisconsideredtobeadequatebecauseofthefailsafedesignandactuationwilloverrideanyactionsofthefeedwatercontrolsystem.2.LocationOverfillprotectionandfeedwatercontrolarephysicallylocatedinseparatecabinets.3.Routin-OverfillProtectionTheSGleveltransmitters,arelocatedinside,.containment.LevelsignalsfromfourofthetransmittersexitcontainmentintheAuxiliaryBuildingIntermediateFloor(ABI).TwoofthelevelsignalsexitcontainmentintheIntermediateBuildingBasement(IBB).Thetripbistablesarelo'catedinprotectionracksintheControlRoom.ThebasicrelaycontactsforsolenoidactuationarelocatedintheSIA&SIBracksintheRelayRoom.RoutingfromthepenetrationtothevalveisillustratedonTable1.Routin-FeedwaterControlTheFeedwaterControlSystemislocatedinthefeedwaterrackintheRelayRoom.TheSGlevelsignalistakenfromLT-461and,LT-471channelsviaisolatorslocatedintheprotectionracksintheControlRoomandsuppliedtothefeedwaterrack.ThevalvecontrolsignalisroutedfromthefeedwaterracktothecontrolvalvesasillustratedonTable1.Overfillprotectionandfeedwatercontrolsharecommonfireareasbutarenotroutedinthesamecable.AreviewofGinna'ssafeshutdowncapabilityintheeventofanycrediblepostulatedfire(whichincludethecommonareas)wasdocumentedinourfireprotectionandAppendixRconformancereviews,andapprovedbytheNRCinSafetyEvaluationReportsdated02/14/79 (FireProtection)and02/27/85(AppendixR).Also,RG&Ehas~documentedcontingencyactionsintheeventoffiresinspecificareas(e.g.,SC-3.30seriesproceduresandotherplanscoveringfire-fightingstrategiesforsafety-relatedfireareas).Thus,itisconsideredthatallrequiredsituationsinvolvingsafeshutdownintheeventofafirehavebeenaddressed,andnoadditionalchangesarewarranted.4.TechnicalSecifications/SurveillanceTechnicalSpecification3.5.2requiresSGoverfillprotectiontobeoperableandspecifieslimitingconditionsforoperationshouldthesystemorportionsofthesystembecomeinoperable.TechnicalSpecificationTable4.1-1requiresSGlevelbetestedmonthly..There'fore,TechnicalSpecificationsrequireperiodicverificationofsystemoperability.ProceduresareinplacethatimplementtheTechnicalSpecificationrequirements.Also,functionallogictestsareperformedthatverifyvalveresponse.BaseduponTechnicalSpecificationsurveillancerequirements,powersupplyconfiguration,fail-safedesignofoverfillprotection,separatecabinetsandadequatecablerouting(fireshavebeenaddressed.-inAppendixRreviews),theGinnadesignprovidessufficientseparationtoensureautomaticSGoverfillprotectiontomitigateamainfeedwateroverfeedevent.NosystemmodificationsareplannedasaresultofthisGenericLetter.Vertrulyyours,RobertC.cdDivisionManagerNuclearProductionSubscribedandsworntobeforemeonthis19thdaofMarch,1990.g~l,HAUCK~~~&&aedNcYorkRWE/091MONROEcoU~Attachmentxc:Mr.AllenR.Johnson(MailStop14D1)ProjectDirectorateI-3Washington,D.C.20555U.S.NuclearRegulatoryCommissionRegionI475AllendaleRoadKingofPrussia,PA19406GinnaSeniorResidentInspector TABLE1CABLEROUTINGOVERFILLPROTECTIONLevelSicpalLT-4616LT-472LT-463GLT-471ContainmentPenetration(AE10)ABI(AEll)ABIR~outinABI,CT,CRABI,CT,CRProtectionRackLocationCRSIASIBLocationRR.Routine[RR,AHR,TB,ValveRR,AHR,TB,ValveLT-462&LT"473(CE4)IBBIBB,CRCRRR,AHR,TB,ValveFEEDWATERCONTROLSYSTEHLevelSicgialSignalPickupLocationFeedwaterRackLocation~RoutinLT-461LT-471CRCRRRRR,AHR,TB,ValveRR,AHR;'TB,Valve~Leenu:ABI-AuxiliaryBuildingIntermediateFloorIBB-IntermediateBuildingBasementCT-CableTunnelCR-ControlRoomRR-RelayRoomTB-TurbineBuilding V>g~/C.r