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{{Adams
#REDIRECT [[05000315/LER-1998-029]]
| number = ML17326A077
| issue date = 08/04/1999
| title = LER 98-029-01:on 980422,noted That Fuel Handling Area Ventilation Sys Was Inoperable.Caused by Original Design Deficiency.Radiological Analysis for Spent Fuel Handling Accidents in Auxiliary Bldg Will Be Redone by 990830
| author name = BERRY L R
| author affiliation = INDIANA MICHIGAN POWER CO.
| addressee name =
| addressee affiliation =
| docket = 05000315
| license number =
| contact person =
| document report number = LER-98-029, NUDOCS 9908100140
| package number = ML17326A076
| document type = LICENSEE EVENT REPORT (SEE ALSO AO,RO), TEXT-SAFETY REPORT
| page count = 6
}}
 
=Text=
{{#Wiki_filter:NRCFORM366U.S.NUCLEARREGUYCOMMISSION (6-1996)LICENSEEEVENTREPORT(LER){Seereverseforrequirednumberofdigits/characters foreachblock)APPROYOMBNO.3150-0104 EXPIRES06/30/2001 Estimated burdenperresponsetocomplywiththismandatory information collection request:50hrs.Reportedlessonslearnedareincorporated intothelicensing processandfedbacktoindustry.
Forwardcommentsregarding burdenestimatetotheRecordsManagement Branch(TAF33).U.S.NuclearRegulatory Commission.
Washington.
DC205550001, andtothePaperwork Reduction Project(3t500104).
05ceofManagement andBudget,Washington.
DC20503.Ifaninformation collection doesnotdisplayacurrently validOMBcontrolnumber.theNRCmaynotconductorsponsor,andapersonisnotrequiredtorespondto,theinformation collection.
FACILITYNAME(1)CookNuclearPlantUnit1DOCKETNUMBER(2)05000-315 PAOE(3)1OF4TITlEI4IFuelHandlingAreaVentilation SystemInoperable DuetoOriginalDesignDeficiency EVENTDATE{5)LERNUMBER{6)REPORTDATE{7)OTHERFACILITIES INVOLVED{6)MONTHDAYYEARYEAR1998SEQUENTIAL NUMBERREVISIONNUMBERMONTHDAY199FACILITYNAMECookNuclearPlantUnit2FACILllYNAMEDOCKETNUMBER05000-316 DOCKETIIUMBEROPERATING MODE(9)POWERLEVEL(10)20.2201(b) 20.2203(a)(1) 20.2203(a)
(2)(i)20.2203(a)
(2)(ii)20.2203(a)(2)(iii) 20.2203(a)(2)
(iv)20.2203(a)(2)(v) 20.2203(a)(3)(i) 20.2203(a)(3)(ii) 20.2203(a)(4) 50.36(c)(1) 50.36(c)(2)50.73(a)(2)(i) 50.73(a){2)(ii)50.73(a)(2)(iii) 50.73(a){2)(iv)50.73(a)(2)(v) 50.73(a)(2)(vii)
DPURSUANTTOTHEREOUTHISREPORTISSUBMITTEIREMENTSOF10CFRE:(Checkonoormore)(11)50.73(a)(2)(viii) 50.73(a)(2)
(x)73.71OTHERSpecifyinAbstractbeloworinNRCForm366ANAMELICENSEECONTACTFORTHISLERLyleR.Be(Ty,Compliance Engineer{12)TELEPHONE NUMBERIIndudeAreaCode)(616)465-5901x1623COMPLETEONELINEFOREACHCOMPONENT FAILUREDESCRIBEDINTHISREPORT{13)CAUSESYSTEMCOMPONENT MANUFACTURER REPORTABLE "ToEPIXCAUSESYSTEMCOMPONENT MANUFACTURER REPORTABLE ToEPIXSUPPLEMENTAL REPORTEXPECTED14YES{Ifyes,completeEXPECTEDSUBMISSION DATE).XNOEXPECTEDMONTHDAYYEARABSTRACT(Limitto1400spaces,i.o.,approximately 15single-spaced typewritten lines)(16)OnApril22,1998,duringpreparation oftheRadiation Monitoring SystemDesignBasisDocument(DBD),itwasidentified thattheresponsetimeoftheFuelHandlingAreaVentilation System,fortransition fromthenormaltotheemergency filtration mode,maynotbeadequatetopreventanunfiltered releasefromarefueling accidentoutsidecontainment.
Currentoff-sitedosecalculations assumefiltration foranaccidentintheAuxiliary Building.
Thisconcernwasidentified bycontractor personnel reviewing astatement madeinresponsetoNRCQuestion9.4fortheSAR.Thisquestionrequested designdetailstodemonstrate thattheresponsetimeofthecharcoaladsorberbypassdamperwasadequatetopreventapotential "puffrelease"totheenvironment afterahighradiation signalwasreceived.
Afterresearching existingdocumentation andperforming ascopingcalculation, itwasdetermined thattheresponsetimeofthebypassdamperdescribed inreplytotheSARquestionwasinadequate topreventanunfiltered release.Areleasefromarefueling accident(droppedfuelbundle)intheSpentFuelPoolwascalculated toreachthebypassdamperbeforeinitiation ofcharcoalfiltration.
Consequently, sincetheFuelHandlingAreaVentilation Systemhadbeendetermined tobeincapable ofperforming itsspecified
: function, itwasdeclaredinoperable.
Sincethiscondition waspreviously unknown,nocompensatory actionshadbeenhistorically taken.TheFuelHandlingAreaVentilation Systemiscommontobothunits.OnMay27,1998,thiscondition wasdetermined tobereportable pursuanttotherequirements of10CFR50.73(a)(2)(i)(B),
asoperation orcondition prohibited bytheplant'sTechnical Specifications.
Therootcauseofthiscondition isadesigndeficiency, whichhasbeenpresentsinceplantconstruction.
Evaluation ofthiscondition hasdetermined thatevenwithoutthecharcoalbedinservice,theconsequences ofapostulated fuelhandlingaccidentarewellwithin10CFR100limits.Baseduponthisinformation, thiseventhadminimalimpactonthehealthandsafetyofthepublic.9908iOOi40 990804PP"ADCICK0500/13i5
 
NRCFORM366AU.S.NUCLEARADULATORY COMMISSION 16-1998)LICENSEEEVENTREPORT(LER)TEXTCONTINUATION FACIUTYNAMEI1)DocKETI2)LERNUMBERI6)PAGEI3)CookNuclearPlantUnit105000-315 YEARSEQUENTIAL NUMBER2OF4NUMBER199802901TEXT/Ifmorespacoisreriuired, usoadditional copiesofNRCRearm366AII17)Conditions PriortoEventUnit1Mode5,ColdShutdownUnit2Mode5,ColdShutdownDescritionoftheEventOnApril22,1998,duringpreparation oftheRadiation Monitoring SystemDesignBasisDocument(DBD),itwasidentified thattheresponsetimeoftheFuelHandlingAreaVentilation System(EIIS:VG),
fortransition fromthenormaltotheemergency filtration mode,maynotbeadequatetopreventanunfiltered releasefromarefueling accidentoutsidecontainment.
Currentoff-sitedosecalculations assumefiltration intheAuxiliary Building.
Thisconcernwasidentified bycontractor personnel reviewing astatement madeinresponsetoNRCQuestion9.4(Amendment 20,March,1972)fortheSAR.Thisquestionrequested designdetailstodemonstrate thattheresponsetimeofthecharcoaladsorberbypassdamper(EIIS:VG/CDMP) wasadequatetopreventapotential "puffrelease"totheenvironment afterahighradiation signalwasreceived.
TheresponsetoSARQuestion9.4wasasfollows:"Exhausted airfromthespentfuelpitwillreachthecharcoalfilterbypassdampersin4seconds(basedontheshortestpath).Thetimeelapsedfromreceiving ahighradiation signalattheradiation monitortothefullshutpositionofthecarbonfilterbypassdamperislessthan3seconds.Theinvestigation revealedthatthereislittle'existing documentation onthisoriginaldesignfeature.Afteranextensive search,itwasdetermined thatnoinformation couldbelocatedwhichsupported, orprovidedabasisfor,thestatement intheSARQuestion9.4response.
Ascopingcalculation wasperformed forthetimeexpectedforareleasefromtheSpentFuelPooltoreachthedampers.Thiscalculation indicated thattheairtransittimewasfessthan1second,whichislessthanthe3secondresponsetimeforthecombination ofradiation monitoractuation andbypassdampermovement.
Sincenotestdatacouldbelocatedtodemonstrate thatthetransition totheemergency filtration modewasrapidenoughtopreventarelease,thesystemwasconsidered tobeinoperable.
TheFuelHandlingAreaVentilation Systemiscommontobothunits.CauseofEventThiscondition isattributed toadeficiency intheoriginaldesign.Asnodocumentation oftheoriginalpostulated airtransport timeversustimefordamperoperation couldbelocated,itwasnotpossibletoreconstruct thedesignbasisforradiation monitoractuation oftheemergency filtration modeforthesystem'.AnalsisofEventOnMay27,1998,withbothUnit1andUnit2inMode5,itwasconcluded thatthiseventwasreportable under10CFR50.73(a)(2)(i)(B),
asanoperation orcondition prohibited bytheplantTechnical Specifications.
Thisconclusion wasreachedbecausetheFuelHandlingAreaVentilation systemwasinoperable fromtimeofplantstartupandhasremainedinoperable.
Technical Specification 3.9.12,.which prohibits fuelmovementwiththesysteminoperable, wasviolatedwheneverfuelwasmovedwithoutthecharcoalfilterbeinginservice.Theoriginaldelayindetermining thereportability ofthiscondition wasprimarily duetothescarcityofinformation pertaining tothisdesignfeature.NRCFORM366AI6-1996)
NRCFORM366AU.S.NUCLEARREGULATORY COMMISSION (6.1999)LlCENSEEEVENTREPORT(LER)TEXTCONTINUATION FACILITYNAME(1)CookNuclearPlantUnit1DOCKET(2)05000-315 YEARLERNUMBER(6)PAGE(3)SEQUENTIAL REVISION3QF4NUMBERNUMBER199802901TEXTiifmorespaceisrequired, useadditiorIal copiesofIVRCForm366AJ(17)Nodocumentation or.calculation couldbefoundtosupporttheresponsetimeandairtransittimesreportedintheresponsetoQuestion9.4oftheSAR.Apreliminary determination originally concluded thatthecondition wasnotreportable becausetherewasnocommitment orsurveillance totimedampertravel.Thefinaldetermination ofreportability wasmadewhentheresultsofthecalculation wereprovidedandprovedtobelessconservative thanthevaluereportedinresponsetoQuestion9.4oftheSAR.TheFuelHandlingAreaVentilation System(EIIS:VG) isoneofthesubsystems oftheAuxiliary BuildingVentilation System(EIIS:VF).
Thefuelhandlingareaissharedbetweenunitsanditsventilation systemistherefore asharedfacilityconsisting ofanexhaustsystemandasupplysystem.Thesupplyportionofthesystemconsistsoffoursupplyairhandlingunitsandassociated ductwork.
Normallyallfoursupplyairhandlingunitsoperatedrawingoutsideairthroughintakelouversanddischarge itintothefuelhandlingarea.Thecombinedcapacityofthefoursupplyairhandlingunitsislessthanthatofasingleexhaustfan;thusthefuelhandlingareaisnormallymaintained ataslightlynegativepressure.
Thefuelhandlingareaexhaustsystemiscomprised oftwo30,000cfmfans,withanormalconfiguration ofoneoperating fanandoneinstandby.TheexhaustfansdrawairthroughacommoninletplenumandfilterassemblyfromacrossthesurfaceoftheSpentFuelPoolviainletgrillesarrangedalongthenorthsideofthepool.Thefansdischarge theexhaustairtotheoutsideatmosphere viatheAuxiliary BuildingVentstack.TheFuelHandlingAreaVentilation Systemexhaustfilterassemblyiscomposedofrollmediaroughingfilters,highefficiency particulate airfiltersandcharcoalfilters.Thereisanormallyopenbypassdamperandnormallyclosedoutletdamperonthecharcoalfilter.Uponreceiptofahighradiation signalfromtheSpentFuelPoolarearadiation monitor,thebypassdamperclosesandthecharcoalfilteroutletdamperopenstopermitexhaustairflowtopassthroughthecharcoalbedandfiltertheairbeforebeingexhausted uptheplantvent.Thebasicfunctionoftheairfilterassemblyistoremoveparticulate matteraswellasradioactive elemental, iodinefromthefuelhandlingarea,afterreceiptofahighradiation signal,bypassingexhaustairthroughHEPAandcharcoalfilterspnortodischarge totheplantvent.Associated withtheFuelHandlingAreaVentilation Systemairfiltration unit,arepneumatically operatedfaceandbypassdampers,whosebasicfunctionistodirectairfloweitherthroughoraroundthecharcoaladsorbers.
Therearesixnormallyopen,fail-closed dampers(twosetsofthreedampersmountedinseries)inthebypassandtwonormallyclosed,fail-open dampers(onesetoftwoparalleldampers)onthedischarge sideofthecharcoaladsorber.
TheFuelHandlingAreaVentilation Systemisdesignedtolimitoffsitereleasesfollowing afuelhandlingaccident.
Ahighradiation signaIfromthefuelhandlingareawillcausethesystemtoshifttotheemergency filtration modeofoperation.
Thesupplyfanswilltrip,thefiltration unitcharcoaladsorberbypassdamperswillcloseandthedampersdownstream ofthecharcoaladsorberwillopen,thusdiverting exhaustthroughthecharcoalfilters.Asdiscussed above,theresponsetimeoftheFuelHandlingAreaVentilation System,fortransition fromthenormaltotheemergency filtration mode,maynotbeadequatetopreventanunfiltered releasefromaSpentFuelPoolaccident.
However,,evaluation ofthiscondition hasrevealedthatevenwithoutthebenefitsofcharcoaladsorption, theconsequences ofsuchanaccidentarewellwithin10CFR100limits.Asdocumented intheSafetyEvaluation Report(SER)forUnit1Amendment No.124andUnit2Amendment No.211,datedMay19,1989,theNRCperformed anindependent analysisoftheconseq'uences ofafuelhandlingaccidentintheAuxiliary Building.
Inthisanalysis, nocreditwasgivenforremovalofradioiodine bythecharcoalfilters.NRCFORM366A(6-1998)
V NRCFORM366AU.S.NUCLEARREGULATORY COMMISSION (6-1999)LlCENSEEEVENTREPORT(LER)TEXTCONTINUATION
~FACILITYNAME(1)CookNuclearPlantUnit1DOCKET(2)05000-315 YEARLERNUMBER(6)SEQUENTIAL REVISIONNUMBERNUMBERPAGE(3)4OF4199802901TEXT/Ifmorespaceisrequired, useadditional copiesof/I/RCForm368A/(17)Basedupontheanalysis, thestaffconcluded thatthesiteboundarythyroiddose,withoutcreditforcharcoalfiltration orcontainment, meetstheintentofStandardReviewPlan(SRP)section15.7.4,"Radiological Consequences ofFuelHandlingAccidents,"
acceptance criteriaof"wellwithin"the10CFR100exposureguideline values.Basedupontheaboveinformation, thiseventhadminimalimpactonthehealthandsafetyofthepublic.CORRECTIVE ACTIONSTheFuelHandlingAreaVentilation Systemwasdeclaredinoperable withTechnical Specification actionstatement 3.9.12ineffectonApril22,1998.Aradiological calculation wascompleted July3,1999,whichaddresses afuelhandlingaccidentoutsidecontainment withtheexistingfuelsources,specifictothecurrently plannedoffload/reload forUnits1&2.Thiscalculation demonstrates thatevenwithoutFuelhandlingAreaexhaustfiltration, theradiation exposuretopersonnel intheControlRoomwouldbewellwithintheGDC-19limits.Althoughthecalculation isspecifictoControlRoomdoses,conservative assumptions usedinthecalculation provideadditional assurance thatafuelhandlingaccidentwouldresultinoffsitedosesmuchlowerthan10CFR100.Inaccordance withtheguidanceofGenericLetter91-18,anoperability evaluation wascompleted July19,1999,toaddresstheidentified condition.
Thisevaluation concluded thattheFuelHandlingAreaVentilation Systemisoperable, butdegraded.
Ascompensatory action,duringtheupcomingUnit1andUnit2coreONoadandsubsequent reload,foroperations involving movementoffuelwithinthestoragepoolorcraneoperation withloadsoverthestoragepool,thesystemwillbeoperatedcontinuously intheemergency filtration mode.Theappropriate operating andsurveillance procedures havebeenrevisedtosupportthismodeofoperation.'EP:NRC:1260GH, Enforcement Actions98-150,98-151,98-152and98-186ReplytoNoticeOfViolation October13,1998",datedMarch19,1999,responded toidentified programmatic weaknesses intheplantDesignandLicensing Basis.AspartoftheRestarteffort,SystemandProgrammatic assessments intheExpandedSystemReadiness ReviewsandLicensing BasisReviewsarereestablishing anddocumenting theplant'sDesignandLicensing Basis.Theradiological analysisfortheSpentFuelHandlingAccidents intheAuxiliary Buildingisbeingredoneandisscheduled tobecompleted byAugust30,1999.SIMILAREVENTS315/99-013-00 315/99-018-00 315/99-012-00 315/99-011-00 315/99-010-00 NRCFORM366A(6-1998)}}

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