ML17265A469

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LER 98-003-01:on 980904,actuations of CR Emergency Air Treatment Systems (Creats) Occurred.Caused by Radon build-up During Temp Inversion.Creats Actuation Signal Was Reset & Normal Ventilation Was Restored to CR
ML17265A469
Person / Time
Site: Ginna Constellation icon.png
Issue date: 11/25/1998
From: ST MARTIN J
ROCHESTER GAS & ELECTRIC CORP.
To:
Shared Package
ML17265A468 List:
References
LER-98-003, LER-98-3, NUDOCS 9812070106
Download: ML17265A469 (17)


Text

NRCFORM366!5-1999)U.UCLEARREGULATORY COMMISSION LICENSEEEVENTREPORT(LER)(Seereverseforrequirednumberofdigits/characters foreachblock)APPROBYOMBNO.31RMRBC06/30/2001 Estimated burdenperresponsetocomplywiththismandatoInformation collection request:50hrs.Reportedlessonlearnedareincorporated intothelicensing processandfbacktoindustry.

Forwardcommentsregarding burdeestimatetotheRocordsManagement Branch(T4)F33),USNuclearRegulatory Commlsgon,

Washlfon, Dc20550001~andtothePapenvork Reduction Proect(31504104)

(ÃiooofManagement andBudget,Washington, DC20503.aninformation collection doesnotdisplayacurrently valiOMBcontrolnumber,theNRCmaynotconductorsponsor,FACILITYNAME11)R.E.GinnaPowerPlantTITLE(I)DOCKETNUMBER(2)05000244PAGEI3)IOF9RadonBuild-upDuringTemperature Inversion ResultsinActuations ofControlRoomEmergency AirTreatment SystemsF,ÃlfhBFRRFPORTDAF.OTHF.RFCIITFe)INVO.DMONDI09DAYYEAR041998SEOVENDAL REvISIONNIIMBERNDMBER1998-003-01MONIDAY11251998PACILBYNAMEPACILIIYNAME0500005000OPERATINC htoDE(9)POWERLEVEL(10)100THISFPOTISSlJBMITTRD 20.2201(b) 20.2203aI20.2203(a)(2)(i) 20.2203(a)(2)(v) 20.2203a3i20.2203(a)(3)(ii) 50.73(a)(2)(i) 50.73a2ii50.73(a)(2)(iii)

RS)ANTOIFFUIRFIFSO10P'U50.73(a)(

S0.73a73.7120.2203a2ii20.2203(a)(2)(iii) 20.2203(a)(2)(iv)

NAMEJohnSt.Martin

-Technical Assistant 20.2203a450.36(c)(l) 50.36(c)(2)

LICENSEECONTACTFORTHISLER(12)50.73a2iv50.73(a)(2)(v) 50.73(a)(2)(vii) 1ELEPHONE NUMBER(hetudeAreaCode)(716)771-3641 OTHERspecifyiaeaieaedeicer<<iaNacFsnsaeeaCOMPLETEONELINEFOREACHCOhIPONENT FAILUREDESCRIBED INTHISREPORT(13)cAusESYSTEhfCOMPONENT MANVPACIURER REPORTABLE TOEPIXSYSIEMCOMPONENT 0SUPPI,FMRNTAI RFPORTRXPI?CTFD 14YESgfyes,completeEXPECTEDSUBMISSION DATE).XNOEXPECTEDSUBMISSION DATE(15)ABSTRACT(Limitto1400spaces,i.e.,approximately 1Ssinaiospaced typcNTitten lines)(16)OnSeptember 4,1998,atapproximately 0740EDST,theplantwasinMode1atapproximately 100%steadystatereactorpower.ControlRoomRadiation Monitorsreachedtheiralarmsetpoints, andactuatedtheControlRoomEmergency AirTreatment SystemtoisolatetheControlRoomatmosphere toandfromoutsidea3.r.ThesameeventoccurredonSeptember 15,1998atapproximately 0051EDST,andSeptember 18,1998at0452EDST,and,October27,1998at0706EST.Onthesedates,anatmospheric temperature inversion waspresent,andanunusually highconcentration ofRadonbuiltupthatwastrappedduetotheinversion.

ControlRoomRadiation Monitorsalarmedduetothepresenceofthisunusually highconcentration ofnaturally occurring radioactive RadonandRadondecayproducts'mmediate actionwastakentodetermine thesourceofradiation.

Intheseevents,"air samplesweretakenwhichdetermined thatthesourceofradiation wasnaturally occurring RadonandRadondecayproducts.

Theseairsamplesconfirmed thatfissionproductactiv3.ty wasnotthecause.Noimmediate

'corrective actionswererequired.

ARootCauseAnalysiswasconducted.

TheresultsoftheRootCauseAnalysisareoutlinedinSectionIII.C.Corrective actiontopreventrecurrence isoutlinedinSectionV.B.'F812070106

'i)81i24PDRADQCK050002448PDR I1 NRCFORM366AI6-1999)LICENSEEEVENT.REPORT(LER)TEXTCONTINUATION U.S.NUCLEARREGULATORY COMMISSION R.E.GinnaNuclearPowerPlant50-244SEQUENTIAL REVISIONNUMBER'UMBER1998-oas-012OF9TEXTflfmorespeceisrequired, useedditionel copiesofNRCForm366AiI17)I.PRE-EVENT PLANTCONDITIONS:

OnSeptember 4,1998,atapproximately 0740EDST,theplantwasinMode1atapproximately 1009steadystatereactorpower.Unrelated toplantactivities, anatmospheric temperature inversion waspresent.Atemperature inversion limitsthedispersion ofmatterfromthegroundintotheupperatmosphere.

II.DESCRIPTION OFEVENT:A.DATESANDAPPROXIMATE TIMESOFMAJOROCCURRENCES:

000September 4,1998,0740EDST:Firsteventdateandtime.September 4,1998,0740EDST:Discovery dateandtime.September 15r1998r0051EDSTSecondeventdateandtime.September 15,1998,0051EDST:Discovery dateandtime.00September 18,1998,0452EDST:Thirdeventdateandtime.September 18,1998,0452EDST:Discovery dateandtime.00September 18,1998,1631EDST:Invalidactuation ofControlRoomEmergency AirTreatment System.October20,1998,0403EDST:,Invalid actuation ofControlRoomEmergency AirTreatment System.October27,1998,0706EST:Fourtheventdateandtime.0October27,1998,1050EST:Fourtheventdiscovery dateand,time.B.EVENTTheControlRoomRadiation MonitorsmonitoroutsideairinthevicinityoftheControlRoom.Ahighradiation signalononeofthesemonitorswillinitiatetheControlRoomEmergency AirTreatment System(CREATS)filtration trainandisolateeachairsupplypathtoandfromtheControlRoom.NRCFORM366AI6-1998)

NRCFORM366AI6-199BIOIU.S.NUCLEARREGULATORY COMMISSION LlCENSEEEVENTREPORT(LER)TEXTCONTINUATION R.E.GinnaNuclearPowerPlant50-244SEQUENTIAL REVISIONNUMBERNUMBER1998-oo3-013OF9TEXT/Ifmorespaceisrequired, useadditional copiesofNRCForm366A/I17IOnSeptember 4,1998,theplantwasinMode1atapproximately 1004steadystatereactorpower.Duetothetemperature inversion, therewasanunusually highconcentration ofnaturally occurring radioactive RadonandRadondecayproductsintheloweratmosphere.

Atapproximately 0740EDST,ControlRoomRadiation Monitorsreachedtheiralarmsetpoints.

TheCREATSactuatedandisolatedtheControlRoomatmosphere toandfromoutsideairuponreachingthesesetpoints.

Samplesweretakentodetermine theisotopiccontentoftheairintheControlRoom.Thesesamplesdetermined thattherewasanunusually highconcentration ofRadonandRadondecayproductsfromtheoutsideair,andindicated thatfissionproductactivitywasnotthecauseoftheincreaseinradioactivity.

OnSeptember 15,1998,atapproximately 0051EDST,ControlRoomRadiation Monitorsreachedtheiralarmsetpoints andtheCREATSisolatedtheControlRoomatmosphere toandfromoutsideair.Again,atemperature inversion waspresent,andsamplesdetermined thattherewasanunusually highconcentration ofRadonandRadondecayproductsfromtheoutsideair.OnSeptember 18,1998,atapproximately 0452EDST,ControlRoomRadiation Monitorsreachedtheiralarmsetpoints andtheCREATSisolatedtheControlRoomatmosphere toandfromoutsideair.Forathirdtime,atemperature inversion waspresent,andsamplesdetermined thattherewasanunusually highconcentration ofRadonandRadondecayproductsfromtheoutsideair.OnOctober27',1998,atapproximately 0706EST,ControlRoomRadiation Monitorsreachedtheiralarmsetpoints.

Priortothistime,theCREATShadbeenmanuallyisolatedfortroubleshooting oftheControlRoomRadiation Monitors.

Therefore, whentheradiation alarmsoccurred, noCREATSactuation orControlRoomalarmoccurred.

Laterthatmorning(atapproximately 1050EST),Instrument andControl(I&C)technicians observedtheradiation monitoralarmonalocalpaneloutsidetheControlRoom,andnotifiedControlRoomoperators ofthealarm.Anothertemperature inversion wasdetermined tobepresent.NRCFORM366AI6-1998)

NRCFORM366AI6.199BILICENSEEEVENTREPORT(LER)TEXTCONTINUATION U.S.NUCLEARREGULATORY COMMISSION R.E.GinnaNuclearPowerPlant50-244SEQUENTIAL REVISIONNUMBERNUMBER1998-oos-014OF9TEXTflfmorespaceisrequired, useadditional copiesofNRCForm366A/1171Inadditiontothesevalidevents,thereweretwo(2)invalidCREATSactuations thatoccurredintherecentpast.OnSeptember 18,1998,atapproximately 1631EDST,aninvalidCREATSactuation occurred.

ControlRoomoperators checkedtheControlRoomRadiation Monitorslocally,anddiscovered thattherewasnoalarmcondition.

Therewasnotemperature inversion present,andtherehadbeennosignificant increaseinradioactivity asmonitored bytheControlRo'omRadiation Monitors.

Itwasdetermined thatthisevent(September 18at1631EDST)wasaninvalidactuation.

OnOctober20,1998,atapproximately 0403EDST,anotherinvalidCREATSactuation occurred.

ControlRoomoperators determined thatoneoftheControlRoomRadiation Monitorchannelshadspikedabovethealarmsetpoint.

Therewasnotemperature inversion present,andtherehadbeennosignificant increaseinradioactivity asmonitored bytheControlRoomRadiation Monitors.

Itwasdetermined thatthisevent(October20at0403EDST)wasaninvalidactuation.

C~INOPERABLE STRUCTURES rCOMPONENTS rORSYSTEMSTHATCONTRIBUTEDTOTHEEVENT:NoneD.OTHERSYSTEMSORSECONDARY FUNCTIONS AFFECTED:

NoneE.METHODOFDISCOVERY:

TheeventsofSeptember 4,15,and18wereimmediately apparentduetotheactuation ofCREATStoisolatetheControlRoomatmosphere toandfromoutsideair.Theevent.ofOctober27wasnotapparenttoControlRoomoperators, sincetherewasnoCREATSactuation andnoalarmintheControlRoom.Thiseventwasdiscovered byI&Ctechnicians.

NRCFORM366AI6-1998)

NRCFORM366A(6.1998)LICENSEEEVENTREPORT(LER)TEXTCONTINUATION U.S.NUCLEARREGULATORY COMMISSION R.E.GinnaNuclearPowerPlant50-244'SEQUENTIAL REVISIONNUMBERNUMBER1998-oo3-015OF9TEXT/lfmorespaceisrequired, useadditional copiesofNRC&rm366AlI17lF.OPERATORACTION:DuringtheeventsofSeptember 4,15,and18,theControlRoomoperators acknowledged MainControlBoardannunciators associated withtheradiation monitoralarmsandactuation oftheCREATS,enteredAlarmResponseProcedure AR-E-11(ControlRoomHVACIsola'tion),

andnotifiedhighersupervision andtheNRC.Theyconfirmed thatControlRoomRadiation MonitorR-37(whichmeasuresparticulate radiation) waslockedintothealarmcondition.

Independent airsampleswererequested, andwhentheresultsoftheseairsamplesconfirmed thepresenceofradioactivity (RadonandRadondecay'products),

theControlRoomoperators determined that,validactuations oftheCREATShadoccurred.

FortheeventwhichoccurredonOctober27,nooperatorresponseoractionwaswarranted.

TheShiftSupervisor subsequently notifiedtheNRCper,10CFR50.72(b)(2)(ii),non-emergency fourhournotification, atapproximately 1115EDSTonSeptember 4,1998.OnSeptember 15,1998,theNRCwasnotifiedatapproximately 0442EDST.OnSeptember 18,1998,theNRCwasnotifiedatapproximately 0915EDST.Thislastnotification wasslightlybeyondthefourhourtimeframe duetodelaysinconfirming thepresenceofRadonandRadondecayproducts.

OnOctober27,1998,theNRCwasnotifiedatapproximately 1439EST.G.SAFETYSYSTEMRESPONSES:

IFortheeventsofSeptember 4,15,and18,theCREATSactuatedtoisolatetheControlRoomatmosphere toandfromoutsideairwhentheradiation monitorsreachedtheiralarmsetpoints.

FortheeventonOctober27,theCREATSwasalreadyactuatedasaprerequisite fortroubleshooting thesystem,sonoresponseoccurred.

III.CAUSEOFEVENT:A.IMMEDIATE CAUSE:Theimmediate causeoftheactuation oftheCREATSwasControlRoomRadiation Monitorsreachingtheiralarmsetpoints, resulting inisolation oftheControlRoomatmosphere toandfromoutsideair.(OnOctober27,noactuation occurred.)

NRCFORM366AI6-1998)

NRCFORM366A(6-1996)LICENSEEEVENTREPORTILERITEXTCONTINUATiON.

U.S.NUCLEARREGUlATORY COMMISSION R.E.GinnaNuclearPowerPlant50-244SEOUENTIaL REVISIONNUMBERNUMBER1998-oo3-O16OF9TEXTIifmorespeceisrequired, useedditionel copiesofNRCForm366AII17)B.INTERMEDIATE CAUSE:Theintermediate causeoftheradiation monitorsreachingtheiralarmsetpoints wasincreased radioactivity oftheoutsideair,duetoanunusually highconcentration ofRadonandRadondecayproducts.

C.ROOTCAUSE:TherewerevalidandinvalidCREATSactuations duringtherecentpast.Forthevalidactuations, theunderlying causeoftheunusually highconcentration ofRadonandRadondecayproductswasanatmospheric temperature inversion; whichtrappedthenaturally occurring Radonintheloweratmosphere, limitingthedispersion ofmatterfromthegroundintotheupperatmosphere.

Samplestakenconfirmed thattheCREATSactuation wasduetothetemperature inversion, andnotduetofissionproductactivity.

Also,thealarmsetpoints forR-36andR-37havebeenevaluated tobeunnecessarily conservative, whichresultedinCREATSactuations.

DuetotheinvalidCREATSactuations, troubleshooting androotcauseanalysiswereperformed.

Asaresult,additional factorswereidentified thatcontributed totheinvalidCREATSactuations.

TheControlRoomRadiation Monitorisactuallythree(3)separatechannelsthatanalyzeacommonsampleofoutsideairbeingsuppliedtotheCREATS.ChannelR-36monitorsnoblegas.ChannelR-37monitorsparticulate.

ChannelR-38monitorsiodine.IGCpersonnel identified thatthedetectorforR-37wasgrounded.

Theyalsodiscovered adamageddetectorcableforR-37,andfounddamagedinsulation onthepowersupplycabletotheControlRoomRadiation Monitor.IV.ANALYSISOFEVENT:Theseeventsarereportable inaccordance with10CFR50.73,,LicenseeEventReportSystem,item(a)(2)(iv),whichrequiresareportof,"anyeventorcondition thatresultedinmanualorautomatic actuation ofanyEngineered SafetyFeature(ESF)including theReactorProtection System(RPS)".CREATSislistedinNUREG-1022 asanexamplesystemofwhattheNRCstaffconsiders tobeasystem"provided

.to.mitigate theconsequences ofasignificant event."NRCFORM366AIS-1998)

I\

NRCFORM366A(8-1998)LICENSEEEVENTREPORT(LER)TEXTCONTINUATION U.S.NUCLEARREGULATORY COMMISSION R.E.GinnaNuclearPowerPlant50-244SEQUENTIAL REVISIONNUMBERNUMBER1998-,,oos-017OF9TEXT/Ifmorespaceisrequired, useadditional copiesofNRCFarm366AiI17)Anassessment wasperformed'onsidering boththesafetyconsequences andimplications ofthiseventwiththefollowing resultsandconclusions:

Therewerenooperational orsafetyconsequences orimplications attributed toCREATSactuation because:oTheCREATSprovidesaprotected environment fromwhichoperators cancontroltheplantfollowing anuncontrolled releaseofradioactivity.

Therewasnouncontrolled releaseofradioactivity whichoccurredonSeptember 4,September 15,September 18,andOctober27.0TheCREATSactuation wasinresponsetoincreased radioactivity inthevicinityoftheControlRoom.However,theincreased radioactivity wasduetonaturally occurring RadonandRadondecayproducts.

Theincreaseinradiation detectedwasnotduetoanyplantactivity.

Specifically, itwasnotduetoanincreaseinfissionproductactivitynoranuncontrolled releaseofradioactivity.

0CREATSfunctioned asperdesign,toisolatetheControlRoominresponsetolevelsofradioactivity thatresultedinreachingthealarmsetpoints ontheControlRoomRadiation Monitors.

Basedontheabove,itcanbeconcluded thattheplantoperatedasdesigned, thattherewerenounreviewed safetyquestions, andthatthepublic'shealthandsafetywasassuredatalltimes.V.CORRECTIVE ACTION:A.ACTIONTAKENTORETURNAFFECTEDSYSTEMSTOPRE-EVENT NORMALSTATUS:Attheconclusion ofthethreetemperature inversions inSeptember, andaftertheControlRoomRadiation Monitorsdecreased belowtheiralarmsetpoints, theCREATSactuation signalwasreset,andnormalventilation wasrestoredtotheControlRoom.FortheeventofOctober27,noCREATSactuation occurred,'and noactionswerewarranted.

NRCFORM366AI6-1998)

NRCFORM366AI6-1998)LICENSEEEVENTREPORT(LER)TEXTCONTINUATION U.S.NUCLEARREGULATORY COMMISSION R.E.GinnaNuclearPowerPlant50-244SEQUENTIAL REVISIONNUMBERNUMBER1998-oo3-018OF9TEXTllfmorespaceisrequired, useadditional copiesofiVRCRearm'366AlI17)B~ACTIONTAKENORPLANNEDTOPREVENTRECURRENCE; 0Therootcauseofthevalidactuations wastheunusually highconcentration ofRadonandRadondecayproductsduringanatmospheric temperature inversion, whichtrappedthenaturally occurring Radonintheloweratmosphere, limitingthedispersion ofmatterfromthegroundintotheupper'tmosphere.

Thisisanaturalphenomenon.

0ThesetpointforR-37willbeadjustedtoeliminate unnecessary conservatism inthesetpointforactuation oftheCREATS.00ThesetpointforR-36hasbeenevaluated todetermine ifthereisunnecessary conservatism inthesetpoint.

TheR-36setpointwillremainunchanged.

Contributing factorstotheinvalidCREATSactuations, whichwereduetospikingontheseradiation

monitors, havebeenaddressed bythefollowing actions:1.ThegroundedR-37detectorandthedamagedR-37detectorcablehavebeenreplaced.

2.Thedamagedinsulation onthepowersupplycablehasbeenreplaced.

VI.ADDITIONAL INFORMATION:

A.FAILEDCOMPONENTS:

Thefailedcomponents includedtheR-37particulate detector(failedduetobeinggrounded) andthedetectorcable(failedduetocold-working).

Thesecomponents weremanufactured byorsuppliedbyNuclearResearchCorporation.

ThedetectorisModelNo.MD-34DT.B.PREVIOUSLERsONSIMILAREVENTS:AsimilarLEReventhistorical searchwasconducted withthefollowing results:Nodocumentation ofsimilarLEReventswiththesamerootcauseatGinnaStationcouldbeidentified.

NRCFORM366AI6-1998I

NRCFORM366AI6-1999)LICENSEEEVENTREPORT(LER)TEXTCONTINUATION U.S.NUCLEARREGULATORY COMMISSION R.E.GinnaNuclearPowerPlant50-244SEQUENTIAL REVISIONNUMBERNUMBER1998-003-019OF9TEXT(Ifmorespeceisrequired, useadditional copiesol'VRCForm366AlI17),C.SPECIALCOMMENTS:

Until1998,GinnaStationdidnotconsidertheCREATStobeanESF.In1998,newNRCguidancewaspromulgated inNUREG-1022, Revision1.NRCspecifically listedtheHeating,Ventilating andAirConditioning SystemforControlRoomasanexampleofanESFsystem.Therefore, GinnaStationreporting procedures wererevisedin1998tobeinaccordance withthisNRCguidance.

Individuals recallthat,priorto1998,thereweresomeCREATSactuations atGinnaStation.However,theseactuations werenotreportable at=-thosetimes.Sincetheseearlieractuations werenotreportable, nodocuments existtoconfirmanyoftheseearlieroccurrences.

NRCFORM366AI6-1998)