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{{Adams
#REDIRECT [[05000259/LER-2017-003]]
| number = ML17177A576
| issue date = 06/26/2017
| title = LER 17-003-00 for Browns Ferry, Unit 1, Regarding Unanalyzed Condition for Tornado Missiles Striking the Emergency Diesel Generator Fuel Oil Vent Lines
| author name = Bono S M
| author affiliation = Tennessee Valley Authority
| addressee name =
| addressee affiliation = NRC/Document Control Desk, NRC/NRR
| docket = 05000259, 05000260, 05000296
| license number = DPR-033, DPR-052, DPR-068
| contact person =
| document report number = LER 17-003-00
| document type = Letter, Licensee Event Report (LER)
| page count = 8
}}
 
=Text=
{{#Wiki_filter:Tennessee ValleyAuthority, PostOfficeBox2000,Decatur,Alabama35609-2000 June26,2017ATTN:DocumentControlDeskU.S.NuclearRegulatory Commission Washington, D.C.20555-0001 10CFR50.73BrownsFerryNuclearPlant,Units1,2,and3RenewedFacilityOperating LicenseNos.DPR-33,DPR-52,andDPR-68NRCDocketNos.50-259,50-260,and50-296
 
==Subject:==
LicenseeEventReport50-259/2017-003-00 TheenclosedLicenseeEventReport(LER)providesdetailsofanunanalyzed condition fortornadomissilesstrikingtheEmergency DieselGenerator FuelOilVentLines.TheTennessee ValleyAuthority (TVA)issubmitting thisreportinaccordance withTitle10oftheCodeofFederalRegulations (CFR)10CFR50.73(a)(2)(ii)(B),
asanyeventorcondition thatresultedinthenuclearpowerplantbeinginanunanalyzed condition thatsignificantly degradedplantsafety;and10CFR50.73(a)(2)(v)(A)I(B)/(D),
asanyeventorcondition thatcouldhaveprevented thefulfillment ofthesafetyfunctionofstructures orsystemsthatareneededtoshutdownthereactorandmaintainitinasafeshutdowncondition, removeresidualheat,ormitigatetheconsequences ofanaccident.
Furtherevaluation isunderwaytodetermine iftheBrownsFerryNuclearPlantissusceptible toadditional tornadomissileeffects.Atthistime,WAanticipates theneedtosupplement thisLERwiththeresultsofthatevaluation.
Therearenonewregulatory commitments contained inthisletter.Shouldyouhaveanyquestions concerning thissubmittal, pleasecontactJ.L.Paul,NuclearSiteLicensing Manager,at(256)729-2636.
Respectfully, S.M.BonoSiteVicePresident
 
==Enclosure:==
 
LicenseeEventReport50-259/2017-003-00
-Unanalyzed Condition forTornadoMissilesStrikingtheEmergency DieselGenerator FuelOilVentLines U.S.NuclearRegulatory Commission Page2June26,2017cc(wiEnclosure):
NRCRegionalAdministrator
-RegionIINRCSeniorResidentInspector
-BrownsFerryNuclearPlant ENCLOSURE BrownsFerryNuclearPlantUnit1,2,and3LicenseeEventReport50-259/2017-003-00 Unanalyzed Condition forTornadoMissilesStrikingtheEmergency DieselGenerator FuelOilVentLinesSeeEnclosed NRCFORM366U.S.NUCLEARREGULATORY COMMISSION APPROVEDBY0MB:NO.3150.0104 EXPIRES:03/3112020 (04-2017)
Estimated burdenperresponsetocomplywiththismandatory collection request:80hours.,.'."Reportedlessonslearnedareincorporated intothelicensing processandfedbacktoindustry.
Sendcommentsregarding burdenestimatetotheInformation ServicesBranch(1-2F43),U.S.NuclearRegulatory Commission, Washington, DC20555-0001, orbye-mailtoInfocollects.
Resource@nrc.gov, andtotheDeskOfficer,OfficeofInformation andRegulatory Affairs,NEOB-10202,(3150-0104),
OffceofManagement andBudget,Washington, DC20503.Ifameansusedtoimposeaninformation collection doesnotdisplayacurrently valid0MBcontrolnumber,theNRCmaynotconductorsponsor,andapersonisnotrequiredtorespondto,theinformation collection.
1.FACILITYNAME2.DOCKETNUMBER3.PAGEBrownsFerryNuclearPlant,Unit1050002591OF54.TITLEUnanalyzed Condition forTornadoMissilesStrikingtheEmergency DieselGenerator FuelOilVentLines5.EVENTDATE6.LERNUMBER7.REPORTDATE8.OTHERFACILITIES INVOLVEDSEQUENTIAL FACILITYNAMEDOCKETNUMBERMONTHDAYYEARYEARNUMBERMONTHDAYYEARBrownsFerryNuclear,Unit205000260042520172017-003-0006262017FACILITYNAMEDOCKETNUMBERBrownsFerryNuclear,Unit305000296_________________
9.OPERATING MODE__________________
__________
_____11.THISREPORTISSUBM11EDPURSUANTTOTHEREQUIREMENTS OF10CFR:(Checkallthatapply)El20.2201(b) 020.2203(a)(3)(i) 05073(a)(2)(ii)(A) 050.73(a)(2)(viii)(A) 1020.2201(d) 020.2203(a)(3)(ii) 50.73(a)(2)(ii)(B) 050.73(a)(2)(viii)(B) o20.2203(a)(1)
El20.2203(a)(4)
El50.73(a)(2)(iii) 050.73(a)(2)(ix)(A) o20.2203(a)(2)(i) 050.36(c)(1)(i)(A) 050.73(a)(2)(iv)(A)
El50.73(a)(2)(x)
____________________
10.POWERLEVEL020.2203(a)(2)(ii)
El50.36(c)(1)(ii)(A) 50.73(a)(2)(v)(A) 073.71(a)(4) o202203(a)(2)(iii)
El50.36(c)(2) 50.73(a)(2)(v)(B)
El73.71(a)(5) 100020.2203(a)(2)(iv) 050.46(a)(3)(ii)
El50.73(a)(2)(v)(C)
El73.77(a)(1)
El202203(a)(2)(v)
El50.73(a)(2)(i)(A)
Z50.73(a)(2)(v)(D) 073.77(a)(2)(i)
El202203(a)(2)(vi)
El50.73(a)(2)(i)(B)
El50.73(a)(2)(vii) 073.77(a)(2)(ii) 050.73(a)(2)(i)(C) 0OTHERSpecifyinAbstractbeloworinNRCForm366A12.LICENSEECONTACTFORTHISLERLICENSEECONTACTTELEPHONE NUMBER(IncludeAreaCode)RyanCoons,Licensing Engineer56-729-2070 13.COMPLETEONEUNEFOREACHCOMPONENT FJLUREDESCRIBED INTHISREPORTCAUSESYSTEMCOMPONENT FACTURERREPORTABLE CAUSESYSTEMCOMPONENT FACTURERREPORTABLE N/AN/AN/AN/AN/AN/AN/AN/AN/AN/A14.SUPPLEMENTAL REPORTEXPECTED15.EXPECTEDMONTHDAYYEARYES(Ifyes,complete15.EXPECTEDSUBMISSION DATE)LINOSUBMISSION 08252017BSTRACT(Limitto1400spaces,i.e.,approximately 15single-spaced typewritten fines)Inaccordance withNRCRegulatory IssueSummary(RIS)2015-06,TornadoMissileProtection, adesignandlicensing basisreviewwasperformed toevaluatetheeffectsofexposingsafetyrelatedfeaturestotornadowindloads,depressurization loads,andstrikesfromtornadogenerated missiles.
OnApril25,2017,itwasdiscovered thatatornadomissilestrikecouldpotentially damagetheexposedandunprotected portionoftheD,3A,3B,3C,and3DEmergency DieselGenerator (EDG)fueloilventlines.Thiscouldpotentially fullycrimptheventline,anddisablethetank'svacuumprevention feature.Developing avacuuminthefueloilsystemwouldlimitthefueloilpump'sabilitytotransferfueloilfromthe7daytanktothedaytank,restricting oreliminating thefueloilflowtotheaffectedEDG,whichwouldpreventtheEDGfromfunctioning.
Thedevelopment ofavacuummayalsodamagethe7daytank.Thiscondition isanoriginalplantdesignlegacyissue.Duetothehistorical natureofthisvulnerability, aspecificcausewasnotidentified.
Ihecompensatory measuresimplemented providealternate fueltankventingassoonasatornadowarninghasbeendeclared.
Thisisimplemented byremovingasamplingplugfromeachof7dayfueltankmanholecoversinsidetheD,3A,3B,3C,and3DEDGrooms.NRCFORM366(04-2017)
NRCFORM366AU.S.NUCLEARREGULATORY COMMISSION APPROVEDBY0MB:NO.3150-0104 EXPIRES:3/3112020 (04-2017)
Estimated burdenperresponsetocomplywiththismandatory collection request:80hours.Reportedlessonslearnedareincorporated intothelicensing processandfedbacktoindustry.
SendLICENSEEEVENTREPORT(LER)commentsregarding burdenestimatetotheInformation ServicesBranch(T-2F43),U.S.NuclearCONTINUATION SHEETRegulatory Commission, Washington, DC20555-0001, orbye-mailtolnfocollects.Resoercenrc.gov, andtotheDeskOfficer,OfficeofInformation andRegulatory Affairs,NEOB-10202,(3150-0104),
OfficeofManagement andBedget,Washington, DC20503.Ifameansusedtoimposeaninformation collection doesnotdisplayacurrently valid0MBcontrolnumber,theNRCmaynotconductorsponsor,andapersonisnotrequiredtorespondto,theinformation collection.
1.FACILITYNAME2.DOCKETNUMBER3.LERNUMBER YEARSEQUENTIAL REVNUMBERINO.BrownsFerryNuclearPlant,Unit105000-259 2017-003-00NARRATIVE I.PlantOperating Conditions BeforetheEventAtthetimeofdiscovery, BrownsFerryNuclearPlant(BFN),Units1,2,and3,wereinMode1at100percentpower.ILDescription ofEventA.EventSummaryInaccordance withNRCRegulatory IssueSummary(RIS)2015-06,TornadoMissileProtection (TMP),adesignandlicensing basisreviewwasperformed toevaluatetheeffectsofexposingsafetyrelatedfeaturestotornadowindloads,depressurization loads,andstrikesfromtornadogenerated missiles.
OnApril25,2017,itwasdiscovered duringthisevaluation thatdamagetotheexposedandunprotected portionoftheD,3A,3B,3C,and3DEmergency DieselGenerator (EDG)[DC]fueloilventlines[VLR]byatornadomissilestrikehasthepotential tofullycrimptheventline,whichwouldrenderthevacuumprevention featureineffective.
Developing avacuuminthefueloilsystem[DE]wouldlimittheabilityofthefueloilpumps[P]totransferfueloilfromthe7daytank[TK]tothedaytank.Thiswouldrestrictoreliminate theflowoffueloiltotheaffectedEDG,whichwouldpreventtheEDGfromfunctioning.
Adevelopment ofavacuummayalsodamagethe7daytank.B.Statusofstructures, components, orsystemsthatwereinoperable atthestartoftheeventandthatcontributed totheeventTherewerenostructures, systems,orcomponents whoseinoperability contributed tothiscondition.
C.Datesandapproximate timesofoccurrences Dates&Approximate TimesOccurrence April25,2017,TheD,3A,3B,3C,and3DEDGsweredeclaredat1630CDTinoperable following anengineering evaluation ofTMP,whichfoundthattheEDG7daytankventpipingissubjecttopotential damage.April25,2017,Inaccordance withNRCEnforcement Guideat1631CDTMemorandum (EGM)15-002,Revision1,Enforcement Discretion forTornado-Generated MissileProtection Non-Compliance, initialcompensatory measureswereimplemented whichprovideadditional protection andlessentornadomissileeffects.NRCFORM366A(04-2017)
Page2of5 NRCFORM366AU.S.NUCLEARREGULATORY COMMISSION APPROVEDBY0MB:NO.3150-0104 EXPIRES:313112020 (04-2017)
Estimated burdenperresponsetocomplywiththismandatory collection request:80hours.Reportedlessonslearnedareincorporated intothelicensing processandfedbacktoindustry.
SendLICENSEEEVENTREPORT(LER)commentsregarding burdenestimatetotheInformation ServicesBranch(T-2F43),U.S.NuclearCONTINUATION SHEETRegulatory Commission, Washington, DC20555-0001, orbye-mailtolnfocollects.Resource@nrc.gov, andtotheDeskOfficer,OfficeofInformation andRegulatory Affairs,NEOB-10202,(3150-0104),
OfficeofManagement andBudget,Washington, DC20503.Ifameansusedtoimposeaninformation collection doesnotdisplayacurrently valid0MBcontrolnumber,theNRCmaynotconductorsponsor,andapersonisnotrequiredtorespondto,theinformation collection.
1.FACILITYNAMEI2.DOCKETNUMBERI3.LERNUNIBER YEARSEQUENTIAL REVNUMBERNO.BrownsFerryNuclearPlant,Unit105000-259 2017-003-00Dates&Approximate TimesOccurrence April25,2017,TheD,3A,3B,3C,and3DEDGsweredeclaredat1647CDTOperableatthistime.April25,2017,TheNRCwasnotifiedoftheunanalyzed condition thatat1653CDTsignificantly degradedplantsafety.D.Manufacturer andmodelnumberofeachcomponent thatfailedduringtheeventThiscondition didnotinvolveanyequipment failure.E.Othersystemsorsecondary functions affectedNoothersystemsorsecondary functions wereaffectedbythiscondition.
F.Methodofdiscovery ofeachcomponent orsystemfailureorprocedural errorThiseventdidnotinvolvetheactualfailureofplantequipment.
However,anunanticipated potential forfailurewasdiscovered onApril25,2017,aspartofadesignandlicensing basisreviewtoevaluatetheeffectsoftornadosandtornadomissilesonsafetyrelatedfeatures, inaccordance withRIS2015-06.G.Thefailuremode,mechanism, andeffectofeachfailedcomponent Thiscondition didnotinvolvetheactualfailureofplantequipment.
H.OperatoractionsTherewerenooperatoractionsassociated withthiscondition.
I.Automatically andmanuallyinitiated safetysystemresponses Therewerenoautomatic ormanualsafetysystemresponses associated withthiscondition.
Ill.CauseoftheeventA.Causeofeachcomponent orsystemfailureorpersonnel errorThiscondition isanoriginalplantdesignlegacyissue.Duetothehistorical natureofthisvulnerability, aspecificcausewasnotidentified.
B.Cause(s)andcircumstances foreachhumanperlormance relatedrootcauseTherewerenohumanperformance relatedrootcausesforthiscondition.
NRCFORM366A(04-2017)
Page3of5 NRCFORM366AU.S.NUCLEARREGULATORY COMMISSION APPROVEDBY0MB:NO.3150-0104 EXPIRES:3/31/2020 (04-2017)
Estimated burdenperresponsetocomplywiththismandatory collection request:80hours.Reportedlessonslearnedareincorporated intothelicensing processandfedbacktoindustry.
SendLICENSEEEVENTREPORT(LER)commentsregarding burdenestimatetotheInformation ServicesBranch(T-2F43),U.S.NuclearCONTINUATION SHEETRegulatory Commission, Washington, DC20555-0001, orbye-mailtolnfocollects.Resourcenrc.gov, andtotheDeskOfficer,OfficeofInformation andRegulatory Affairs,NEOB-10202,(3150-0104),
OfficeofManagement andBudget,Washington, DC20503.Ifameansusedtoimposeaninformation collection doesnotdisplayacurrently valid0MBcontrolnumber,theNRCmaynotconductorsponsor,andapersonisnotrequiredtorespondto,theinformation collection.
1.FACILITYNAMEI2.DOCKETNUMBERI3.LERNUMBER YEARSEQUENTIAL REVINUMBERINO.BrownsFerryNuclearPlant,Unit105000-259 2017-003-00IV.AnalysisoftheeventTheTennessee ValleyAuthority (TVA)issubmitting thisreportinaccordance withTitle10oftheCodeofFederalRegulations (CFR)50.73(a)(2)(ii)(B),
asanyeventorcondition thatresultedinthenuclearpowerplantbeinginanunanalyzed condition thatsignificantly degradedplantsafety;and10CFR50.73(a)(2)(v)(A)/(B)/(D),
asanyeventorcondition thatcouldhaveprevented thefulfillment ofthesafetyfunctionofstructures orsystemsthatareneededtoshutdownthereactorandmaintainitinasafeshutdowncondition, removeresidualheat,ormitigatetheconsequences ofanaccident.
Thecondition wasdiscovered onApril25,2017,at1630CDT,whenanengineering evaluation ofTMPdetermined thatthe7daytankventpipingissubjecttopotential damagefortheD,3A,3B,3C,and3DEDGsrendering theEDGsinoperable forpotential tornadomissileprotection.
Anactualtornadomissileeventcouldhavecausedasafetysystemfunctional failureduetotheinoperability ofmultipleEDGs.However,compensatory measureswereestablished toprovideadditional protection foralleviating tornadomissileeffects,inaccordance withEGM15-002,Revision1.Theseinitialcompensatory measuresallowedtheaffectedEDGstobeconsidered Operablebutnonconforming.
Furtherevaluation isunderwaytodetermine ifBFNissusceptible toadditional tornadomissileeffects.Atthistime,WAanticipates theneedtosupplement thisLERwiththeresultsofthatevaluation.
V.Assessment ofSafetyConsequences TheexposedportionofthefueloilventlinesfortheD,3A,3B,3Cand3DEDGsarenotprotected fromatornadogenerated missilestrike.Anexposedportionofafueloilventlinecouldexperience crimpingdamagesuchthatitcannotperformitsfunctiontopreventthedevelopment ofavacuuminthefueloilsystem.Thedevelopment ofavacuuminthefueloilsystemwouldrenderthefueloiltransfersystemfromthe7daytanktothedaytankineffective.
TheaffectedEDG(s)wouldbeunabletofunctionduetolackoffueloil.TopreventtornadomissileinducedEDGinoperability, BFNOperations personnel arenowprocedurally requiredtoopenanalternate ventilation pathontheEDG7dayfueltanksfollowing thedeclaration ofatornadowarning.Thiscondition hadnoactualsafetyconsequences impacting plantorpublicsafetybecauseBFNdidnotexperience anactualtornadomissileevent;however,thecompensatory actionsthathavebeenimplemented intheSevereWeatherprocedure willmanagethiscondition's risktothehealthandsafetyofthepublic.A.Availability ofsystemsorcomponents thatcouldhaveperformed thesamefunctionasthecomponents andsystemsthatfailedduringtheeventThiscondition didnotresultinanyactualsystemorcomponent failures.
NRCFORM366A(04-2017)
Page4of5 NRCFORM366AU.S.NUCLEARREGULATORY COMMISSION APPROVEDBY0MB:NO.3150-0104 EXPIRES:3/3112020 (04-2017)
Estimated burdenperresponsetocomplywiththismandatory collection request:80hours.Reportedlessonslearnedareincorporated intothelicensing processandfedbacktoindustry.
SendLICENSEEEVENTREPORT(LER)commentsregarding burdenestimatetotheInformation ServicesBranch(T-2F43),U.S.NuclearCONTINUATION SHEETRegulatory Commission, Washington, DC20555-0001, orbye-mailtolnfocollects.Resourcenrc.gov, andtotheDeskOfficer,OfficeofInformation andRegulatory Affairs,NEOB-10202,(3150-0104),
OfficeofManagement andBudget,Washington, DC20503.Ifameansusedtoimposeaninformation collection doesnotdisplayacurrently valid0MBcontrolnumber,theNRCmaynotconductorsponsor,andapersonisnotrequiredtorespondto,theinformation collection.
1.FACILITYNAMEI2.DOCKETNUMBERI3.LERNUMBER YEARISEQUENTIAL REVNUMBERINO.BrownsFerryNuclearPlant,Unit105000-259 2017-003-00B.Foreventsthatoccurredwhenthereactorwasshutdown,availability ofsystemsorcomponents neededtoshutdownthereactorandmaintainsafeshutdownconditions, removeresidualheat,controlthereleaseofradioactive
: material, ormitigatetheconsequences ofanaccidentThiscondition didnotoccurduringashutdown.
C.Forfailurethatrenderedatrainofasafetysysteminoperable, estimateoftheelapsedtimefromdiscovery ofthefailureuntilthetrainwasreturnedtoserviceThiscondition isanoriginalplantdesignlegacyissue.Duetothehistorical natureofthisvulnerability, aspecificcausewasnotidentified.
Initialcompensatory measurestorestoreoperability wereimplemented within17minutesofdiscovering thecondition.
VI.Corrective ActionsCorrective ActionsarebeingmanagedbyTVA'scorrective actionprogramunderCondition Report(CR)1288222.A.Immediate Corrective ActionsAnoperatorworkaround wasimplemented toprovideanalternate fueltankventingassoonaspossiblefollowing atornadoevent.B.Corrective ActionstoPreventRecurrence ortoreducetheprobability ofsimilareventsoccurring inthefutureThecomprehensive compensatory measuresincludedrevisingtheSevereWeatherprocedure toincluderemovingasamplingplugoneachoftheEDG7dayfueloiltankstoprovideanalternate ventilation pathwhenatornadowarninghasbeendeclared.
Thesecomprehensive compensatory measureswillremaininplaceuntilthevulnerability ispermanently resolved.
VII.PreviousSimilarEventsattheSameSiteAsearchoftheBFNCorrective ActionProgramidentified nosimilarconditions thathaveoccurredatBFN.VIII.Additional Information Thereisnoadditional information.
IX.Commitments Therearenonewcommitments.
NRCFORM366A(04-2017)
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