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{{#Wiki_filter:ACCELERATEDDTRIBUTIONDEMONSTIONSYSTEMREGULATORYINFORMATIONDISTRIBUTIONSYSTEM(RIDS)ACCESSIONNBR:9202120022DOC.DATE:92/02/03NOTARIZED:YESDOCKETFACIL:50-244RobertEmmetGinnaNuclearPlant,Unit1,RochesterG05000244AUTH.NAMEAUTHORAFFILIATIONMECREDY,R.C.RochesterGas6ElectricCorp.RECIP.NAMERECIPIENTAFFILIATIONJOHNSON,A.R.ProjectDirectorateI-3
{{#Wiki_filter:ACCELERATED DTRIBUTION DEMONSTIONSYSTEMREGULATORY INFORMATION DISTRIBUTION SYSTEM(RIDS)ACCESSION NBR:9202120022 DOC.DATE:
92/02/03NOTARIZED:
YESDOCKETFACIL:50-244 RobertEmmetGinnaNuclearPlant,Unit1,Rochester G05000244AUTH.NAMEAUTHORAFFILIATION MECREDY,R.C.
Rochester Gas6ElectricCorp.RECIP.NAME RECIPIENT AFFILIATION JOHNSON,A.R.
ProjectDirectorate I-3


==SUBJECT:==
==SUBJECT:==
ForwardsresponsestoGenericLtr91-11,"ResolutionofGenericIssues48'LCOsforClass1EVitalInstrumentBuses649'Interlocks&LCOsforClass1ETieBreakers.'"DISTRIBUTIONCODE:A027DCOPIESRECEIVED:LTRENCLSIZE:TITLE:GenericLtr91-11-ResolutionsofGenericIssues48649DNOTES:LicenseExpdateinaccordancewith10CFR2,2.109(9/19/72).05000244ARECIPIENTIDCODE/NAMEPDl-3LAJOHNSON,AINTERNAL:NRRCHOPRA,ONRR/DET/ECMB7DNRR/DOEA/OTSB11NRR/DST/SELB7ENRR/DST/SRXB8EOC/EPIRGFILE01EXTERNAL:NRC'PDRCOPIESLTTRENCL11221111111111101111RECIPIENTIDCODE/NAMEPD1-3PDNRRHOFFMAN,SNRR/DET/ESGBNRR/DST8E2NRR/DST/SICB8H7NUDOCS-ABSTRACTOGC/HDS1RES/DSIR/EIBNSICCOPIESLTTRENCL111111111111101111DD(gas7~1/0~RDNOTETOALL"RIDS"RECIPIENTS:DDPLEASEHELPUSTOREDUCEWASTE!CONTACTTHEDOCUMENTCONTROLDESK,ROOMPl-37(EXT.20079)TOELIMINATEYOURNAMEFROMDISTRIBUTIONLISTSFORDOCUMENTSYOUDON'TNEED!TOTALNUMBEROFCOPIESREQUIRED:LTTR20ENCL18pt' I
Forwardsresponses toGenericLtr91-11,"Resolution ofGenericIssues48'LCOsforClass1EVitalInstrument Buses649'Interlocks
0zzzzzizIIIItIISr@(ZZROCHESTERGASANDELECTRICCORPORATION0e9EASTAVENUE,ROCHESTERN.Y.14649-0001ROBERT&MECREQYVicePreiidentCtnneNucteerProductionU.S.NuclearRegulatoryCommissionDocumentControlDeskAttn:AllenR.JohnsonProject,DirectorateI-3Washington,D.C.20555TELEPHONEFebruary3,1992AREAoooETte546-2700
&LCOsforClass1ETieBreakers.'"
DISTRIBUTION CODE:A027DCOPIESRECEIVED:LTR ENCLSIZE:TITLE:GenericLtr91-11-Resolutions ofGenericIssues48649DNOTES:License Expdateinaccordance with10CFR2,2.109(9/19/72).
05000244ARECIPIENT IDCODE/NAME PDl-3LAJOHNSON,A INTERNAL:
NRRCHOPRA,ONRR/DET/ECMB 7DNRR/DOEA/OTSB11 NRR/DST/SELB 7ENRR/DST/SRXB 8EOC/EPIRGFILE01EXTERNAL:
NRC'PDRCOPIESLTTRENCL11221111111111101111RECIPIENT IDCODE/NAME PD1-3PDNRRHOFFMAN,S NRR/DET/ESGB NRR/DST8E2NRR/DST/SICB8H7 NUDOCS-ABSTRACT OGC/HDS1RES/DSIR/EIB NSICCOPIESLTTRENCL111111111111101111DD(gas7~1/0~RDNOTETOALL"RIDS"RECIPIENTS:
DDPLEASEHELPUSTOREDUCEWASTE!CONTACTTHEDOCUMENTCONTROLDESK,ROOMPl-37(EXT.20079)TOELIMINATE YOURNAMEFROMDISTRIBUTION LISTSFORDOCUMENTS YOUDON'TNEED!TOTALNUMBEROFCOPIESREQUIRED:
LTTR20ENCL18pt' I
0zzzzzizIIIItIISr@(ZZROCHESTER GASANDELECTRICCORPORATION 0e9EASTAVENUE,ROCHESTER N.Y.14649-0001 ROBERT&MECREQYVicePreiident CtnneNucteerProduction U.S.NuclearRegulatory Commission DocumentControlDeskAttn:AllenR.JohnsonProject,Directorate I-3Washington, D.C.20555TELEPHONE February3,1992AREAoooETte546-2700


==Subject:==
==Subject:==
ResolutionofGenericIssues48,"LCO'sforVitalBuses",and49,"InterlocksandLCO's1ETieBreakers"Pursuantto10CFR50.54(f)Letter91-11)datedJuly18,1991R.F..GinnaNuclearPowerPlantDocketNo.50-244Class1EforClass(Generic
Resolution ofGenericIssues48,"LCO'sforVitalBuses",and49,"Interlocks andLCO's1ETieBreakers" Pursuantto10CFR50.54(f)Letter91-11)datedJuly18,1991R.F..GinnaNuclearPowerPlantDocketNo.50-244Class1EforClass(Generic


==DearMr.Johnson:==
==DearMr.Johnson:==
GenericLetter91-11requestedawrittenresponsewithin180daystocertifythatproceduresconformtoGL91-11guidanceandcanresolveGenericIssues48"LCO'sforClasslEVitalInstrumentBuses",and49,"InterlocksandLCO'sforClass1ETieBreakers"pursuantto10CFR50.54(f).TheattachedreportdescribeshowGinnaStationmeetstheguidanceoftheGenericLetter.Asaresultofthereviewperformedinrespondingtotheseissues,someplantprocedureswererevisedatGinnaStationasanadditionalmeasuretoensurethattheGenericLetterconcernsareaddressed.Verytrulyyours,AttachmentRobertC.MecredyPJAIAOOQ-010OOGIW00Cd&N&OOOQGI&GlOEt:ETtlAQQ.Q-Subscribedandsworntobeforemeonthis3rddayofFebruary,1992*'RACYPAYbrF.thddP<<54InLur~rdI'MYotItMGiQOECGUIiTI'c:.AllnR.Johnson(MailStop14D1)ProjectDirectorateI-3Washington,D.C.20555U.S.NuclearRegulatoryCommissionRegionI475AllendaleRoadKingofPrussia,PA19406GinnaSeniorResidentInspectoraGigj5~,IP IIIIIt AttachmentIResonsetoGenericLetter91-11ThisattachmentisinresponsetoGenericLetter91-11whichwasissuedtoresolveGenericIssues48,"LCO'sforClass1EVitalnstrumentBuses",and-49,"InterlocksandLCO'sforClass1ETieBreakers".Theintentofthisreviewistoensurethatplantproceduresincludetimelimitationsandsurveillancerequirementsforthefollowing:1.Vitalinstrumentbuses2.Invertersandotheronsitepowersourcesforthevitalinstrumentbuses,and3.Tiebreakersandorfusesthatcanconnectredundantclass1Ebuses(Bothacand.dc).Thisevaluationrequiredareviewoftheexistingsystemconfiguration,operatingprocedures,andTechnicalSpecificationrequirements.Asaresultofthisevaluation,adequatejustificationshallbeprovidedthatGinnaStationfulfillsthefollowingrequirements:2.LimitthetimethatGinnaStationisinpossibleviolationofthesinglefailurecriterioninregardtotheClass1Evitalinstrumentbusesandtiebreakers,Requiresurveillanceofthesecomponents,and3.Ensurethat,exceptforthetimescoveredinItem(1),theplantisoperatinginanelectricalconfigurationconsistentwiththeregulationsanditsdesignbasis.VitalInstrumentBusesSystemConfiguration:Genericletter91-11definesvitalinstrumentbusesasthe120VACbusesthatprovidepowerfortheinstrumentationandcontrolsoftheengineeredsafetyfeatures(ESF)systemsandthereactorprotectionsystem(RPS)andaredesignedtoprovidecontinuouspowerduringpostulatedeventsincludingthelossofnormaloff-sitepowertocriticalequipment.TheresolutionofGI-48requiresthatGinnaStationhasadministrativecontrolsgoverningoperationalrestrictionsforthevitalinstrumentbusesandassociatedinverters.1  
GenericLetter91-11requested awrittenresponsewithin180daystocertifythatprocedures conformtoGL91-11guidanceandcanresolveGenericIssues48"LCO'sforClasslEVitalInstrument Buses",and49,"Interlocks andLCO'sforClass1ETieBreakers" pursuantto10CFR50.54(f).Theattachedreportdescribes howGinnaStationmeetstheguidanceoftheGenericLetter.Asaresultofthereviewperformed inresponding totheseissues,someplantprocedures wererevisedatGinnaStationasanadditional measuretoensurethattheGenericLetterconcernsareaddressed.
'The120VACinstrumentsupplyatGinnaStationissplitintofourbuses(A,B,CandD)whicharecapableofbeingsuppliedbymultiplesources.Aseparateinverter,MQ-483,alsoprovidespowertocriticalinstrumentation.TheinstrumentbusessupplyinstrumentchannelsA,B,CandD.Powersourcesforeachinstrumentbusissummarizedasfollows:InstrumentBusA:NormallysuppliedbyinverterAfromDCBatteryA(TrainA).Thisbusremainscontinuouslyenergizedduringalossofoff-sitepower.InstrumentBusAalsohasanautomatictransfer(staticswitch)toasafetyrelatedconstantvoltagetransformerfedfrom480VACmotorcontrolcenterC(TrainA).InstrumentBusB:Thisbusisnormallysuppliedfrom480VACBus14viaMCC-C(TrainA)throughaconstantvoltagetransformer.1nstrumentBusBwillde-energizeonalossofoff-sitepowerandisrestoredwhentheEmergencyDieselGeneratorclosesinonBus14.InstrumentBusC:InstrumentBusD:NormallysuppliedbyinverterCfromDCBatteryB(TrainB).Thisbusremainscontinuouslyenergizedduringalossofoff-sitepower.InstrumentBusCalsohasanautomatictransfer(staticswitch)toasafetyrelatedconstantvoltagetransformerfedfrom480VACmotorcontrolcenterD(TrainB).Thisbusisnormallysuppliedfrom480VACBus15viaMCC-B(nonsafetyrelated)throughaconstantvoltagetransformer.InstrumentBusDwillde-energizeonalossofoff-sitepower.Thisbuswillre-energizewhenpowerisrestored.tonon-class1EBus15.InverterMQ-483:Athirdinverter,MQ-483,poweredfromBatteryA(TrainA)providespowertocriticalchannelDinstrumentstoassuretheavailabilityofsafetyrelatedsystemsandtopreventactuationsduringalossofoffsitepower.Thisinverterdoesnothaveabackupsupply.Areviewofthepowersourcesfortheinstrumentbusesindicatesthatduringalossofoffsitepower,InstrumentChannelsAandCandMQ-483willremaincontinuouslyenergized.ThesebusesmeettheGenericLetter91-11definitionforvitalinstrumentbuses.AtGinnaStationbusesA,B,C'andMQ-483areconsideredsafetyrelatedsupplies.BusDisconsiderednon-safetyrelated.
Verytrulyyours,Attachment RobertC.MecredyPJAIAOOQ-010OOGIW00Cd&N&OOOQGI&GlOEt:ETtlAQQ.Q-Subscribed andsworntobeforemeonthis3rddayofFebruary, 1992*'RACYPAYbrF.thddP<<54InLur~rdI'MYotItMGiQOECGUIiTI'c:.AllnR.Johnson(MailStop14D1)ProjectDirectorate I-3Washington, D.C.20555U.S.NuclearRegulatory Commission RegionI475Allendale RoadKingofPrussia,PA19406GinnaSeniorResidentInspector aGigj5~,IP IIIIIt Attachment IResonsetoGenericLetter91-11Thisattachment isinresponsetoGenericLetter91-11whichwasissuedtoresolveGenericIssues48,"LCO'sforClass1EVitalnstrument Buses",and-49,"Interlocks andLCO'sforClass1ETieBreakers".
InstrumentbusesA,B,CandDhaveamaintenancesupplyfromnon-class1Ebus13MCC-Aviaaconstantvoltagetransformer.Theconnectiontothemaintenancesupplyisperformedbymanuallyswitchingapairofmechanicallyinterlockedbreakers.Thebreakersareconfiguredsuchthatparallelingofredundantsourcesisprevented..Operatingwiththeinstrumentbusesbeingfedfromtheirbackupsuppliescouldresultintheplantnotsatisfyingthesinglefailurecriterion.TimeConstraints:AreviewwasperformedofexistingoperatingproceduresandTechnicalSpecificationrequirementsforconstraintsthatlimitthetime~thataninstrumentbuscouldbepowered.fromthealternatesupply.Noprocedureswereidentifiedthatlimitedthistime.Althoughnospecifictimeconstraintscouldbeidentified,theoperatingpracticeofGinnaStationhasbeentolimitthedurationtheplantoperateswithaninstrumentbusfedfromitsalternatesupply.Requirementshavebeenaddedtoexistingplantproceduresthatwilllimitthetimedurationthatthesafetyrelatedinstrumentbusescanbefedfrompowersourcesotherthantheirnormalsupplies.SurveillanceRequirements:Areviewwasperformedoftheexistingsystemconfigurationand.operatingprocedurestoassureadequatesurveillancerequirementsexisttoensureproperalignmentoftheinstrumentbussupplies.TheexistingdesignissuchthatcontinuousmonitoringoftheinverterssupplyingvitalinstrumentbusesAandCisprovidedbycontrolroomannunciation.Xfthesupplytothesevitalinstrumentbusestransfersfromtheinverterstothealternatesupplythereisannunciationinthecontrolroomandindicationontheinverters.Existingoperatingproceduresrequirethatinvertersbeinspectedonceeveryshifttoverifytheyarealignedcorrectly.Themaintenancesupplybreakersfortheinstrumentbusesareadministrativelycontrolled.Whenevertheinstrumentbusesarealignedtothemaintenancesupply,proceduresensuretheyarerealignedtotheirnormalsupplyfollowingcompletionofthemaintenanceactivity.Theinstrumentbuspanelsareinthecontrolroom.Theyarelockedandaccessiscontrolledbytheshiftsupervisor.Thesecontrolsensurethattheinstrumentbuseswillnotbealignedinadvertentlytothemaintenancesupplyduringnormaloperatingconditions.
Theintentofthisreviewistoensurethatplantprocedures includetimelimitations andsurveillance requirements forthefollowing:
Theexistingsurveillancerequirements,operatingprocedurestogetherwithouradministrati've'ontrolsprovidesufficientassurancethattheplantoperatesinanelectricalconfigurationconsistentwithitsdesignbasis.TieBreakersfortheClass1EACBusesSystemConfiguration:Thevital480VACsystemisdividedintofourclass1Ebuses,Buses14,16,17and18.EmergencypowertoBus14and18isprovidedbyEmergencyDieselGenerator1Aandtobuses16and17arebyEmergencyDieselGenerator1B.TiebreakersexistbetweenBuses14and16andBuses17and18.ThetiebetweenBuses14and16consistsofabreakerineachbus,onemanuallyoperatedandtheotherelectricallyoperated.Thetiebetweenbuses17and18consistsofasingleelectricallyoperatedbreaker.ThecontrolschemeforthetiebetweenBuses14and16consistsofthefollowing:1.Theelectricallyoperatedbustiebreakercanbeclosedonlyifeitherbus14or16isdeenergizedfromitsnormalandemergencysources,thuspreventinginadvertentclosure.2.Thedieselgeneratorandnormalsupplybreakersonbuses14and16willnotcloseiftheelectricallyoperatedtiebreakerisclosed.3.Theelectricallyoperatedbustiebreakerisautomaticallytrippedonsafetyinjectionand/orundervoltageconditions.ThetiebreakerforBuses17and18ismaintainedinthetestposition(whichpreventsclosureelectricallyandmechanically)abovecoldshutdown.Whenthebreakerisrackedin(belowcoldshutdown),thecontrolschemeconsistsofthefollowing:Thebustiebreakercanonlybeclosed,ifeitherbus17or18isdeenergizedfromitsnormalandemergencysources,thuspreventinginadvertentclosureofthebreaker.2.Thedieselgeneratorandnormalsupplybreakersonbuses17and18willnotcloseifthetiebreakerisclosed.3.Thetiebreakerisautomaticallytrippedonsafetyinjectionand/orundervoltageconditions.
1.Vitalinstrument buses2.Inverters andotheronsitepowersourcesforthevitalinstrument buses,and3.Tiebreakersandorfusesthatcanconnectredundant class1Ebuses(Bothacand.dc).Thisevaluation requiredareviewoftheexistingsystemconfiguration, operating procedures, andTechnical Specification requirements.
TimeConstraints:Areviewwasperformedof,existingoperatingrestrictionsandTechnicalSpecificationrequirementstoassurethatconstraintse..isted.thatlimitedtheclosureofthetiebreakers.ExistingTechnicalSpecificationrequirementsspecifythetiebreakersbetweenBuses14and16andBuses17and18remainopenwhentheplantisabovecoldshutdownconditions(Above200F).SurveillanceRequirements:Areviewwasperformedoftheexistingsystemconfigurationandoperatingprocedurestoassurethatadequatesurveillancerequirementsexisttoassurethatbustiebreakersareopen.ThesystemdesignissuchthatclosureofeithertheelectricallyoperatedtiebreakerbetweenBusses14and16andthebreakerbetween17and18areannunciatedinthecontrolroom.Thereforecontinuousmonitoringofthebreakerstatusismaintained.Inaddition,existingoperatingproceduresrequiredailyverificationthatthetiebreakersareopen.The.TechnicalSpecificationrequiressurveillanceof,thetiebreakersatleastonceevery7days.IntertiesBetweentheClass1EDCTrainsSystemConfiguration:The125VDCsystemisdividedintotwoclass1Etrains(AandB)andonenon-class1Esystem.Theonlycommontiebetweenthetwoclass1Edctrainsisviaanintertiewiththenon-safetyrelatedTechnicalSupportCenterdcsystem.Theintertieisdesignedsothateitherclass1Ebatterytraincanberemovedfromservice.Thisintertieisutilizedonlyduringmaintenance,testingorabnormalplantcondition.Theintertieisalsoconfiguredsobothclass1EbatterysystemscanbeparalleledsimultaneouslythroughtheTechnicalSupportBattery.ExistingprocedurespermitthisconditiononlyduringspecificAppendixRconditionsinwhichsomeprocessinstrumentationfrombothtrainsrequiredforlongtermcooldown.Parallelingbothsafetyrelateddctrainsisrestrictedbytwoseparatekeylocksonthethrowoverswitchesandseparatelockeddisconnectswitchesineachbatteryroom.Keystotheseswitchesarecontrolledbytheshiftsupervisor.
Asaresultofthisevaluation, adequatejustification shallbeprovidedthatGinnaStationfulfillsthefollowing requirements:
Y9TimeConstraints:AreviewwasperformedofexistingoperatingproceduresandTechnicalSpecificationrequirementstoassureexistingconstraintsrestricttheconnectionofbothclass1EDCtrainssimultaneously.ExistingTechnicalSpecificationrequirementsspecifybothclass1Ebatteriesanddcsystemtrainsbeoperablewhentheplantisabovecoldshutdown(Above200P).Existingproceduresdonotallowtheconnectionofeitherclass1Etraintothetechnicalsupportcenterundernormaloperatingconditions.SurveillanceRequirements:Areviewwasperformedoftheexistingsystemconfigurationandoperatingproceduresforadequatesurveillancerequirementstoassurethatclass1EDCtrainsarenottied.together.Existingproceduresprovidespecificseparationstepsatthecompletionoftestingormaintenancewhenintertiesbetweenaclass1Edcsystemandthetechnicalsupportcenterdcsystemoccur.Theintertiesanddisconnectswitchesarelockedopenandthekeysarecontrolledbytheshiftsupervisor.Therearenoproceduresthatallowtheintertieofeitherclass1Edcsystemwiththetechnicalsupportcenterdcsystemundernormaloperatingconditions.Conclusion:Thereviewofexistingsystemconfigurations,procedures,andTechnicalSpecificationrequirementsidentifiedconcernsinregardstothetimelimitsestablishedforthevitalinstrumentbuses.AsaresultoftheseconcernsplantprocedureshavebeenrevisedwhichwillprovideassurancethattheelectricalconfigurationisconsistentwiththeGinnaStationdesignbasis.TherevisedproceduresandthesystemdesignprovideadequateassurancethatthefollowingGenericLetterconcernshavebeenaddressed:LimitthetimethatGinnaStationisinpossibleviolationofthesinglefailurecriterioninregardtotheClass1Evitalinstrumentbusesandtiebreakers,2.3.Requiresurveillanceofthesecomponents,andEnsurethat,exceptforthetimescoveredinItem(1),theplantisoperatinginanelectricalconfigurationconsistentwiththeregulationsanditsdesignbasis.}}
2.LimitthetimethatGinnaStationisinpossibleviolation ofthesinglefailurecriterion inregardtotheClass1Evitalinstrument busesandtiebreakers, Requiresurveillance ofthesecomponents, and3.Ensurethat,exceptforthetimescoveredinItem(1),theplantisoperating inanelectrical configuration consistent withtheregulations anditsdesignbasis.VitalInstrument BusesSystemConfiguration:
Genericletter91-11definesvitalinstrument busesasthe120VACbusesthatprovidepowerfortheinstrumentation andcontrolsoftheengineered safetyfeatures(ESF)systemsandthereactorprotection system(RPS)andaredesignedtoprovidecontinuous powerduringpostulated eventsincluding thelossofnormaloff-sitepowertocriticalequipment.
Theresolution ofGI-48requiresthatGinnaStationhasadministrative controlsgoverning operational restrictions forthevitalinstrument busesandassociated inverters.
1  
'The120VACinstrument supplyatGinnaStationissplitintofourbuses(A,B,CandD)whicharecapableofbeingsuppliedbymultiplesources.Aseparateinverter, MQ-483,alsoprovidespowertocriticalinstrumentation.
Theinstrument busessupplyinstrument channelsA,B,CandD.Powersourcesforeachinstrument busissummarized asfollows:Instrument BusA:NormallysuppliedbyinverterAfromDCBatteryA(TrainA).Thisbusremainscontinuously energized duringalossofoff-sitepower.Instrument BusAalsohasanautomatic transfer(staticswitch)toasafetyrelatedconstantvoltagetransformer fedfrom480VACmotorcontrolcenterC(TrainA).Instrument BusB:Thisbusisnormallysuppliedfrom480VACBus14viaMCC-C(TrainA)throughaconstantvoltagetransformer.
1nstrument BusBwillde-energize onalossofoff-sitepowerandisrestoredwhentheEmergency DieselGenerator closesinonBus14.Instrument BusC:Instrument BusD:NormallysuppliedbyinverterCfromDCBatteryB(TrainB).Thisbusremainscontinuously energized duringalossofoff-sitepower.Instrument BusCalsohasanautomatic transfer(staticswitch)toasafetyrelatedconstantvoltagetransformer fedfrom480VACmotorcontrolcenterD(TrainB).Thisbusisnormallysuppliedfrom480VACBus15viaMCC-B(nonsafetyrelated)throughaconstantvoltagetransformer.
Instrument BusDwillde-energize onalossofoff-sitepower.Thisbuswillre-energize whenpowerisrestored.
tonon-class 1EBus15.InverterMQ-483:Athirdinverter, MQ-483,poweredfromBatteryA(TrainA)providespowertocriticalchannelDinstruments toassuretheavailability ofsafetyrelatedsystemsandtopreventactuations duringalossofoffsitepower.Thisinverterdoesnothaveabackupsupply.Areviewofthepowersourcesfortheinstrument busesindicates thatduringalossofoffsitepower,Instrument ChannelsAandCandMQ-483willremaincontinuously energized.
ThesebusesmeettheGenericLetter91-11definition forvitalinstrument buses.AtGinnaStationbusesA,B,C'andMQ-483areconsidered safetyrelatedsupplies.
BusDisconsidered non-safety related.
Instrument busesA,B,CandDhaveamaintenance supplyfromnon-class1Ebus13MCC-Aviaaconstantvoltagetransformer.
Theconnection tothemaintenance supplyisperformed bymanuallyswitching apairofmechanically interlocked breakers.
Thebreakersareconfigured suchthatparalleling ofredundant sourcesisprevented..
Operating withtheinstrument busesbeingfedfromtheirbackupsuppliescouldresultintheplantnotsatisfying thesinglefailurecriterion.
TimeConstraints:
Areviewwasperformed ofexistingoperating procedures andTechnical Specification requirements forconstraints thatlimitthetime~thataninstrument buscouldbepowered.fromthealternate supply.Noprocedures wereidentified thatlimitedthistime.Althoughnospecifictimeconstraints couldbeidentified, theoperating practiceofGinnaStationhasbeentolimitthedurationtheplantoperateswithaninstrument busfedfromitsalternate supply.Requirements havebeenaddedtoexistingplantprocedures thatwilllimitthetimedurationthatthesafetyrelatedinstrument busescanbefedfrompowersourcesotherthantheirnormalsupplies.
Surveillance Requirements:
Areviewwasperformed oftheexistingsystemconfiguration and.operating procedures toassureadequatesurveillance requirements existtoensureproperalignment oftheinstrument bussupplies.
Theexistingdesignissuchthatcontinuous monitoring oftheinverters supplying vitalinstrument busesAandCisprovidedbycontrolroomannunciation.
Xfthesupplytothesevitalinstrument busestransfers fromtheinverters tothealternate supplythereisannunciation inthecontrolroomandindication ontheinverters.
Existingoperating procedures requirethatinverters beinspected onceeveryshifttoverifytheyarealignedcorrectly.
Themaintenance supplybreakersfortheinstrument busesareadministratively controlled.
Whenevertheinstrument busesarealignedtothemaintenance supply,procedures ensuretheyarerealigned totheirnormalsupplyfollowing completion ofthemaintenance activity.
Theinstrument buspanelsareinthecontrolroom.Theyarelockedandaccessiscontrolled bytheshiftsupervisor.
Thesecontrolsensurethattheinstrument buseswillnotbealignedinadvertently tothemaintenance supplyduringnormaloperating conditions.
Theexistingsurveillance requirements, operating procedures togetherwithouradministrati've
'ontrolsprovidesufficient assurance thattheplantoperatesinanelectrical configuration consistent withitsdesignbasis.TieBreakersfortheClass1EACBusesSystemConfiguration:
Thevital480VACsystemisdividedintofourclass1Ebuses,Buses14,16,17and18.Emergency powertoBus14and18isprovidedbyEmergency DieselGenerator 1Aandtobuses16and17arebyEmergency DieselGenerator 1B.TiebreakersexistbetweenBuses14and16andBuses17and18.ThetiebetweenBuses14and16consistsofabreakerineachbus,onemanuallyoperatedandtheotherelectrically operated.
Thetiebetweenbuses17and18consistsofasingleelectrically operatedbreaker.ThecontrolschemeforthetiebetweenBuses14and16consistsofthefollowing:
1.Theelectrically operatedbustiebreakercanbeclosedonlyifeitherbus14or16isdeenergized fromitsnormalandemergency sources,thuspreventing inadvertent closure.2.Thedieselgenerator andnormalsupplybreakersonbuses14and16willnotcloseiftheelectrically operatedtiebreakerisclosed.3.Theelectrically operatedbustiebreakerisautomatically trippedonsafetyinjection and/orundervoltage conditions.
ThetiebreakerforBuses17and18ismaintained inthetestposition(whichpreventsclosureelectrically andmechanically) abovecoldshutdown.
Whenthebreakerisrackedin(belowcoldshutdown),
thecontrolschemeconsistsofthefollowing:
Thebustiebreakercanonlybeclosed,ifeitherbus17or18isdeenergized fromitsnormalandemergency sources,thuspreventing inadvertent closureofthebreaker.2.Thedieselgenerator andnormalsupplybreakersonbuses17and18willnotcloseifthetiebreakerisclosed.3.Thetiebreakerisautomatically trippedonsafetyinjection and/orundervoltage conditions.
TimeConstraints:
Areviewwasperformed of,existing operating restrictions andTechnical Specification requirements toassurethatconstraints e..isted.
thatlimitedtheclosureofthetiebreakers.
ExistingTechnical Specification requirements specifythetiebreakersbetweenBuses14and16andBuses17and18remainopenwhentheplantisabovecoldshutdownconditions (Above200F).Surveillance Requirements:
Areviewwasperformed oftheexistingsystemconfiguration andoperating procedures toassurethatadequatesurveillance requirements existtoassurethatbustiebreakersareopen.Thesystemdesignissuchthatclosureofeithertheelectrically operatedtiebreakerbetweenBusses14and16andthebreakerbetween17and18areannunciated inthecontrolroom.Therefore continuous monitoring ofthebreakerstatusismaintained.
Inaddition, existingoperating procedures requiredailyverification thatthetiebreakersareopen.The.Technical Specification requiressurveillance of,thetiebreakersatleastonceevery7days.Interties BetweentheClass1EDCTrainsSystemConfiguration:
The125VDCsystemisdividedintotwoclass1Etrains(AandB)andonenon-class 1Esystem.Theonlycommontiebetweenthetwoclass1Edctrainsisviaanintertiewiththenon-safety relatedTechnical SupportCenterdcsystem.Theintertieisdesignedsothateitherclass1Ebatterytraincanberemovedfromservice.Thisintertieisutilizedonlyduringmaintenance, testingorabnormalplantcondition
.Theintertieisalsoconfigured sobothclass1Ebatterysystemscanbeparalleled simultaneously throughtheTechnical SupportBattery.Existingprocedures permitthiscondition onlyduringspecificAppendixRconditions inwhichsomeprocessinstrumentation frombothtrainsrequiredforlongtermcooldown.
Paralleling bothsafetyrelateddctrainsisrestricted bytwoseparatekeylocksonthethrowover switchesandseparatelockeddisconnect switchesineachbatteryroom.Keystotheseswitchesarecontrolled bytheshiftsupervisor.
Y9TimeConstraints:
Areviewwasperformed ofexistingoperating procedures andTechnical Specification requirements toassureexistingconstraints restricttheconnection ofbothclass1EDCtrainssimultaneously.
ExistingTechnical Specification requirements specifybothclass1Ebatteries anddcsystemtrainsbeoperablewhentheplantisabovecoldshutdown(Above200P).Existingprocedures donotallowtheconnection ofeitherclass1Etraintothetechnical supportcenterundernormaloperating conditions.
Surveillance Requirements:
Areviewwasperformed oftheexistingsystemconfiguration andoperating procedures foradequatesurveillance requirements toassurethatclass1EDCtrainsarenottied.together.
Existingprocedures providespecificseparation stepsatthecompletion oftestingormaintenance wheninterties betweenaclass1Edcsystemandthetechnical supportcenterdcsystemoccur.Theinterties anddisconnect switchesarelockedopenandthekeysarecontrolled bytheshiftsupervisor.
Therearenoprocedures thatallowtheintertieofeitherclass1Edcsystemwiththetechnical supportcenterdcsystemundernormaloperating conditions.
 
==
Conclusion:==
 
Thereviewofexistingsystemconfigurations, procedures, andTechnical Specification requirements identified concernsinregardstothetimelimitsestablished forthevitalinstrument buses.Asaresultoftheseconcernsplantprocedures havebeenrevisedwhichwillprovideassurance thattheelectrical configuration isconsistent withtheGinnaStationdesignbasis.Therevisedprocedures andthesystemdesignprovideadequateassurance thatthefollowing GenericLetterconcernshavebeenaddressed:
LimitthetimethatGinnaStationisinpossibleviolation ofthesinglefailurecriterion inregardtotheClass1Evitalinstrument busesandtiebreakers, 2.3.Requiresurveillance ofthesecomponents, andEnsurethat,exceptforthetimescoveredinItem(1),theplantisoperating inanelectrical configuration consistent withtheregulations anditsdesignbasis.}}

Revision as of 12:09, 29 June 2018

Forwards Responses to Generic Ltr 91-11, Resolution of Generic Issues 48, 'Lcos for Class 1E Vital Instrument Buses & 49, 'Interlocks & LCOs for Class 1E Tie Breakers.'
ML17262A742
Person / Time
Site: Ginna 
Issue date: 02/03/1992
From: MECREDY R C
ROCHESTER GAS & ELECTRIC CORP.
To: JOHNSON A R
NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM), Office of Nuclear Reactor Regulation
References
REF-GTECI-048, REF-GTECI-049, REF-GTECI-NI, TASK-A-48, TASK-A-49, TASK-OR GL-91-11, NUDOCS 9202120022
Download: ML17262A742 (10)
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Text

ACCELERATED DTRIBUTION DEMONSTIONSYSTEMREGULATORY INFORMATION DISTRIBUTION SYSTEM(RIDS)ACCESSION NBR:9202120022 DOC.DATE:

92/02/03NOTARIZED:

YESDOCKETFACIL:50-244 RobertEmmetGinnaNuclearPlant,Unit1,Rochester G05000244AUTH.NAMEAUTHORAFFILIATION MECREDY,R.C.

Rochester Gas6ElectricCorp.RECIP.NAME RECIPIENT AFFILIATION JOHNSON,A.R.

ProjectDirectorate I-3

SUBJECT:

Forwardsresponses toGenericLtr91-11,"Resolution ofGenericIssues48'LCOsforClass1EVitalInstrument Buses649'Interlocks

&LCOsforClass1ETieBreakers.'"

DISTRIBUTION CODE:A027DCOPIESRECEIVED:LTR ENCLSIZE:TITLE:GenericLtr91-11-Resolutions ofGenericIssues48649DNOTES:License Expdateinaccordance with10CFR2,2.109(9/19/72).

05000244ARECIPIENT IDCODE/NAME PDl-3LAJOHNSON,A INTERNAL:

NRRCHOPRA,ONRR/DET/ECMB 7DNRR/DOEA/OTSB11 NRR/DST/SELB 7ENRR/DST/SRXB 8EOC/EPIRGFILE01EXTERNAL:

NRC'PDRCOPIESLTTRENCL11221111111111101111RECIPIENT IDCODE/NAME PD1-3PDNRRHOFFMAN,S NRR/DET/ESGB NRR/DST8E2NRR/DST/SICB8H7 NUDOCS-ABSTRACT OGC/HDS1RES/DSIR/EIB NSICCOPIESLTTRENCL111111111111101111DD(gas7~1/0~RDNOTETOALL"RIDS"RECIPIENTS:

DDPLEASEHELPUSTOREDUCEWASTE!CONTACTTHEDOCUMENTCONTROLDESK,ROOMPl-37(EXT.20079)TOELIMINATE YOURNAMEFROMDISTRIBUTION LISTSFORDOCUMENTS YOUDON'TNEED!TOTALNUMBEROFCOPIESREQUIRED:

LTTR20ENCL18pt' I

0zzzzzizIIIItIISr@(ZZROCHESTER GASANDELECTRICCORPORATION 0e9EASTAVENUE,ROCHESTER N.Y.14649-0001 ROBERT&MECREQYVicePreiident CtnneNucteerProduction U.S.NuclearRegulatory Commission DocumentControlDeskAttn:AllenR.JohnsonProject,Directorate I-3Washington, D.C.20555TELEPHONE February3,1992AREAoooETte546-2700

Subject:

Resolution ofGenericIssues48,"LCO'sforVitalBuses",and49,"Interlocks andLCO's1ETieBreakers" Pursuantto10CFR50.54(f)Letter91-11)datedJuly18,1991R.F..GinnaNuclearPowerPlantDocketNo.50-244Class1EforClass(Generic

DearMr.Johnson:

GenericLetter91-11requested awrittenresponsewithin180daystocertifythatprocedures conformtoGL91-11guidanceandcanresolveGenericIssues48"LCO'sforClasslEVitalInstrument Buses",and49,"Interlocks andLCO'sforClass1ETieBreakers" pursuantto10CFR50.54(f).Theattachedreportdescribes howGinnaStationmeetstheguidanceoftheGenericLetter.Asaresultofthereviewperformed inresponding totheseissues,someplantprocedures wererevisedatGinnaStationasanadditional measuretoensurethattheGenericLetterconcernsareaddressed.

Verytrulyyours,Attachment RobertC.MecredyPJAIAOOQ-010OOGIW00Cd&N&OOOQGI&GlOEt:ETtlAQQ.Q-Subscribed andsworntobeforemeonthis3rddayofFebruary, 1992*'RACYPAYbrF.thddP<<54InLur~rdI'MYotItMGiQOECGUIiTI'c:.AllnR.Johnson(MailStop14D1)ProjectDirectorate I-3Washington, D.C.20555U.S.NuclearRegulatory Commission RegionI475Allendale RoadKingofPrussia,PA19406GinnaSeniorResidentInspector aGigj5~,IP IIIIIt Attachment IResonsetoGenericLetter91-11Thisattachment isinresponsetoGenericLetter91-11whichwasissuedtoresolveGenericIssues48,"LCO'sforClass1EVitalnstrument Buses",and-49,"Interlocks andLCO'sforClass1ETieBreakers".

Theintentofthisreviewistoensurethatplantprocedures includetimelimitations andsurveillance requirements forthefollowing:

1.Vitalinstrument buses2.Inverters andotheronsitepowersourcesforthevitalinstrument buses,and3.Tiebreakersandorfusesthatcanconnectredundant class1Ebuses(Bothacand.dc).Thisevaluation requiredareviewoftheexistingsystemconfiguration, operating procedures, andTechnical Specification requirements.

Asaresultofthisevaluation, adequatejustification shallbeprovidedthatGinnaStationfulfillsthefollowing requirements:

2.LimitthetimethatGinnaStationisinpossibleviolation ofthesinglefailurecriterion inregardtotheClass1Evitalinstrument busesandtiebreakers, Requiresurveillance ofthesecomponents, and3.Ensurethat,exceptforthetimescoveredinItem(1),theplantisoperating inanelectrical configuration consistent withtheregulations anditsdesignbasis.VitalInstrument BusesSystemConfiguration:

Genericletter91-11definesvitalinstrument busesasthe120VACbusesthatprovidepowerfortheinstrumentation andcontrolsoftheengineered safetyfeatures(ESF)systemsandthereactorprotection system(RPS)andaredesignedtoprovidecontinuous powerduringpostulated eventsincluding thelossofnormaloff-sitepowertocriticalequipment.

Theresolution ofGI-48requiresthatGinnaStationhasadministrative controlsgoverning operational restrictions forthevitalinstrument busesandassociated inverters.

1

'The120VACinstrument supplyatGinnaStationissplitintofourbuses(A,B,CandD)whicharecapableofbeingsuppliedbymultiplesources.Aseparateinverter, MQ-483,alsoprovidespowertocriticalinstrumentation.

Theinstrument busessupplyinstrument channelsA,B,CandD.Powersourcesforeachinstrument busissummarized asfollows:Instrument BusA:NormallysuppliedbyinverterAfromDCBatteryA(TrainA).Thisbusremainscontinuously energized duringalossofoff-sitepower.Instrument BusAalsohasanautomatic transfer(staticswitch)toasafetyrelatedconstantvoltagetransformer fedfrom480VACmotorcontrolcenterC(TrainA).Instrument BusB:Thisbusisnormallysuppliedfrom480VACBus14viaMCC-C(TrainA)throughaconstantvoltagetransformer.

1nstrument BusBwillde-energize onalossofoff-sitepowerandisrestoredwhentheEmergency DieselGenerator closesinonBus14.Instrument BusC:Instrument BusD:NormallysuppliedbyinverterCfromDCBatteryB(TrainB).Thisbusremainscontinuously energized duringalossofoff-sitepower.Instrument BusCalsohasanautomatic transfer(staticswitch)toasafetyrelatedconstantvoltagetransformer fedfrom480VACmotorcontrolcenterD(TrainB).Thisbusisnormallysuppliedfrom480VACBus15viaMCC-B(nonsafetyrelated)throughaconstantvoltagetransformer.

Instrument BusDwillde-energize onalossofoff-sitepower.Thisbuswillre-energize whenpowerisrestored.

tonon-class 1EBus15.InverterMQ-483:Athirdinverter, MQ-483,poweredfromBatteryA(TrainA)providespowertocriticalchannelDinstruments toassuretheavailability ofsafetyrelatedsystemsandtopreventactuations duringalossofoffsitepower.Thisinverterdoesnothaveabackupsupply.Areviewofthepowersourcesfortheinstrument busesindicates thatduringalossofoffsitepower,Instrument ChannelsAandCandMQ-483willremaincontinuously energized.

ThesebusesmeettheGenericLetter91-11definition forvitalinstrument buses.AtGinnaStationbusesA,B,C'andMQ-483areconsidered safetyrelatedsupplies.

BusDisconsidered non-safety related.

Instrument busesA,B,CandDhaveamaintenance supplyfromnon-class1Ebus13MCC-Aviaaconstantvoltagetransformer.

Theconnection tothemaintenance supplyisperformed bymanuallyswitching apairofmechanically interlocked breakers.

Thebreakersareconfigured suchthatparalleling ofredundant sourcesisprevented..

Operating withtheinstrument busesbeingfedfromtheirbackupsuppliescouldresultintheplantnotsatisfying thesinglefailurecriterion.

TimeConstraints:

Areviewwasperformed ofexistingoperating procedures andTechnical Specification requirements forconstraints thatlimitthetime~thataninstrument buscouldbepowered.fromthealternate supply.Noprocedures wereidentified thatlimitedthistime.Althoughnospecifictimeconstraints couldbeidentified, theoperating practiceofGinnaStationhasbeentolimitthedurationtheplantoperateswithaninstrument busfedfromitsalternate supply.Requirements havebeenaddedtoexistingplantprocedures thatwilllimitthetimedurationthatthesafetyrelatedinstrument busescanbefedfrompowersourcesotherthantheirnormalsupplies.

Surveillance Requirements:

Areviewwasperformed oftheexistingsystemconfiguration and.operating procedures toassureadequatesurveillance requirements existtoensureproperalignment oftheinstrument bussupplies.

Theexistingdesignissuchthatcontinuous monitoring oftheinverters supplying vitalinstrument busesAandCisprovidedbycontrolroomannunciation.

Xfthesupplytothesevitalinstrument busestransfers fromtheinverters tothealternate supplythereisannunciation inthecontrolroomandindication ontheinverters.

Existingoperating procedures requirethatinverters beinspected onceeveryshifttoverifytheyarealignedcorrectly.

Themaintenance supplybreakersfortheinstrument busesareadministratively controlled.

Whenevertheinstrument busesarealignedtothemaintenance supply,procedures ensuretheyarerealigned totheirnormalsupplyfollowing completion ofthemaintenance activity.

Theinstrument buspanelsareinthecontrolroom.Theyarelockedandaccessiscontrolled bytheshiftsupervisor.

Thesecontrolsensurethattheinstrument buseswillnotbealignedinadvertently tothemaintenance supplyduringnormaloperating conditions.

Theexistingsurveillance requirements, operating procedures togetherwithouradministrati've

'ontrolsprovidesufficient assurance thattheplantoperatesinanelectrical configuration consistent withitsdesignbasis.TieBreakersfortheClass1EACBusesSystemConfiguration:

Thevital480VACsystemisdividedintofourclass1Ebuses,Buses14,16,17and18.Emergency powertoBus14and18isprovidedbyEmergency DieselGenerator 1Aandtobuses16and17arebyEmergency DieselGenerator 1B.TiebreakersexistbetweenBuses14and16andBuses17and18.ThetiebetweenBuses14and16consistsofabreakerineachbus,onemanuallyoperatedandtheotherelectrically operated.

Thetiebetweenbuses17and18consistsofasingleelectrically operatedbreaker.ThecontrolschemeforthetiebetweenBuses14and16consistsofthefollowing:

1.Theelectrically operatedbustiebreakercanbeclosedonlyifeitherbus14or16isdeenergized fromitsnormalandemergency sources,thuspreventing inadvertent closure.2.Thedieselgenerator andnormalsupplybreakersonbuses14and16willnotcloseiftheelectrically operatedtiebreakerisclosed.3.Theelectrically operatedbustiebreakerisautomatically trippedonsafetyinjection and/orundervoltage conditions.

ThetiebreakerforBuses17and18ismaintained inthetestposition(whichpreventsclosureelectrically andmechanically) abovecoldshutdown.

Whenthebreakerisrackedin(belowcoldshutdown),

thecontrolschemeconsistsofthefollowing:

Thebustiebreakercanonlybeclosed,ifeitherbus17or18isdeenergized fromitsnormalandemergency sources,thuspreventing inadvertent closureofthebreaker.2.Thedieselgenerator andnormalsupplybreakersonbuses17and18willnotcloseifthetiebreakerisclosed.3.Thetiebreakerisautomatically trippedonsafetyinjection and/orundervoltage conditions.

TimeConstraints:

Areviewwasperformed of,existing operating restrictions andTechnical Specification requirements toassurethatconstraints e..isted.

thatlimitedtheclosureofthetiebreakers.

ExistingTechnical Specification requirements specifythetiebreakersbetweenBuses14and16andBuses17and18remainopenwhentheplantisabovecoldshutdownconditions (Above200F).Surveillance Requirements:

Areviewwasperformed oftheexistingsystemconfiguration andoperating procedures toassurethatadequatesurveillance requirements existtoassurethatbustiebreakersareopen.Thesystemdesignissuchthatclosureofeithertheelectrically operatedtiebreakerbetweenBusses14and16andthebreakerbetween17and18areannunciated inthecontrolroom.Therefore continuous monitoring ofthebreakerstatusismaintained.

Inaddition, existingoperating procedures requiredailyverification thatthetiebreakersareopen.The.Technical Specification requiressurveillance of,thetiebreakersatleastonceevery7days.Interties BetweentheClass1EDCTrainsSystemConfiguration:

The125VDCsystemisdividedintotwoclass1Etrains(AandB)andonenon-class 1Esystem.Theonlycommontiebetweenthetwoclass1Edctrainsisviaanintertiewiththenon-safety relatedTechnical SupportCenterdcsystem.Theintertieisdesignedsothateitherclass1Ebatterytraincanberemovedfromservice.Thisintertieisutilizedonlyduringmaintenance, testingorabnormalplantcondition

.Theintertieisalsoconfigured sobothclass1Ebatterysystemscanbeparalleled simultaneously throughtheTechnical SupportBattery.Existingprocedures permitthiscondition onlyduringspecificAppendixRconditions inwhichsomeprocessinstrumentation frombothtrainsrequiredforlongtermcooldown.

Paralleling bothsafetyrelateddctrainsisrestricted bytwoseparatekeylocksonthethrowover switchesandseparatelockeddisconnect switchesineachbatteryroom.Keystotheseswitchesarecontrolled bytheshiftsupervisor.

Y9TimeConstraints:

Areviewwasperformed ofexistingoperating procedures andTechnical Specification requirements toassureexistingconstraints restricttheconnection ofbothclass1EDCtrainssimultaneously.

ExistingTechnical Specification requirements specifybothclass1Ebatteries anddcsystemtrainsbeoperablewhentheplantisabovecoldshutdown(Above200P).Existingprocedures donotallowtheconnection ofeitherclass1Etraintothetechnical supportcenterundernormaloperating conditions.

Surveillance Requirements:

Areviewwasperformed oftheexistingsystemconfiguration andoperating procedures foradequatesurveillance requirements toassurethatclass1EDCtrainsarenottied.together.

Existingprocedures providespecificseparation stepsatthecompletion oftestingormaintenance wheninterties betweenaclass1Edcsystemandthetechnical supportcenterdcsystemoccur.Theinterties anddisconnect switchesarelockedopenandthekeysarecontrolled bytheshiftsupervisor.

Therearenoprocedures thatallowtheintertieofeitherclass1Edcsystemwiththetechnical supportcenterdcsystemundernormaloperating conditions.

==

Conclusion:==

Thereviewofexistingsystemconfigurations, procedures, andTechnical Specification requirements identified concernsinregardstothetimelimitsestablished forthevitalinstrument buses.Asaresultoftheseconcernsplantprocedures havebeenrevisedwhichwillprovideassurance thattheelectrical configuration isconsistent withtheGinnaStationdesignbasis.Therevisedprocedures andthesystemdesignprovideadequateassurance thatthefollowing GenericLetterconcernshavebeenaddressed:

LimitthetimethatGinnaStationisinpossibleviolation ofthesinglefailurecriterion inregardtotheClass1Evitalinstrument busesandtiebreakers, 2.3.Requiresurveillance ofthesecomponents, andEnsurethat,exceptforthetimescoveredinItem(1),theplantisoperating inanelectrical configuration consistent withtheregulations anditsdesignbasis.

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