ML17292A590

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Special Rept:On 961023,intermediate & High Range Stack Monitors PRM-RE-1B & PRM-RE-1C Declared Inoperable.Caused by Monitor Output Had Upward Trend Due to Electronic Noise Interference.Work Request Generated
ML17292A590
Person / Time
Site: Columbia Energy Northwest icon.png
Issue date: 11/08/1996
From: BEMIS P R
WASHINGTON PUBLIC POWER SUPPLY SYSTEM
To: CALLAN L J
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
References
GO2-96-221, NUDOCS 9611190144
Download: ML17292A590 (4)


Text

CATEGORY, REGULA'INFORMATION DISTRIBUTI SYSTEM(RIDS)ACCESSION NBR:9611190144 DOC.DATE:

96/ll/08NOTARIZED:

NODOCKETFACIAL:50-397 WPPSSNuclearProject,Unit2,Washington PublicPowe05000397AUTH.NAMEAUTHORAFFILIATION BEMIS,P.R.

Washington PublicPowerSupplySystemRECIP.NAME RECIPIENT AFFILIATION CAILAN,L.J.

Region4(Post820201)

SUBJECT:

Specialrept:on961023,intermediate

&highrangestackmonitorsPRM-RE-lB 6PRM-RE-1C declaredinoperable.

Causedbymonitoroutputhadupwardtrendduetoelectronic noiseinterference.

Workrequestgenerated.

DISTRIBUTION CODE:IE22DCOPIESRECEIVED:LTR ENCLSIZE:TITLE:50.73/50.9 LicenseeEventReport(LER),IncidentRpt,etc.NOTES:RECIPIENT IDCODE/NAME PD4-2PDCOPIESLTTRENCLRECIPIENT IDCODE/NAME COLBURNFT COPIESLTTRENCLINTERNAL:

ACRSAEOD/SPD/RRAB NRR/DE/ECGB NRR/DE/EMEB NRR/DRCH/HICB NRR/DRCH/HQMB NRR/DSSA/SPLB RES/DSIR/EIB EXTERNAL:

LSTLOBBYWARDNOACMURPHYFG.A NRCPDRILECENTNRRDEEELBNRR/DRCH/HHFB NRR/DRCH/HOLB NRR/DRPM/PECB NRR/DSSA/SRXB RGN4FILE01LITCOBRYCE,JHNOACPOOREFW.NUDOCSFULLTXTENOTETOALL"RIDS"RECIPIENTS:

PLEASEHELPUSTOREDUCEWASTE.TOHAVEYOURNAMEORORGANIZATION REMOVEDFROMDISTRIBUTION LZSTStORREDUCETHENUMBEROFCOPIESRECEIVEDBYYOUORYOURORGANIZATION, CONTACTTHEDOCUMENTCONTROLDESK(DCD)ONEXTENSION 415-2083TOTRLNUMBEROFCOPIESREQUIRED:

LTTR26ENCL WASHINGTON PUBLICPOWERSUPPLYSYSTEMPO.Box968~3000GeorgeWasirington Way~Richland, Washington 99352.0968

~(509)372-5000November8,1996G02-96-221 DocketNo.50-397L.J.CallanRegionalAdministrator U.S.NuclearRegulatory Commission RegionIV611RyanPlazaDrive,Suite400Arlington, TX76011-8064

DearMr.Callan:

Subject:

WNP-2,OPERATING LICENSENPF-21SPECIALREPORTREACTORBUILDINGEFFLUENTMONITORING SYSTEMThisspecialreportissubmitted pursuanttotherequirements ofWNP-2Technical Specification Section3.3.7.5,"Accident Monitoring Instrumentation,"

Table3.3.7.5-1, Item31,"ReactorBuildingEffluentMonitoring System."ActionStatement 81forthisspecification requiresthat,"WiththenumberofOPERABLEaccidentmonitoring instrumentation channelslessthanrequiredbytheminimumchannelsOPERABLErequirement, eitherrestoretheinoperable channel(s) toOPERABLEstatuswithin72hours,orinitiatethepreplanned alternate methodofmonitoring theappropriate parameters and...prepareandsubmitaSpecialReporttotheCommission pursuanttoSpecification 6.9.2within14daysfollowing theevent..."

Threeradiation monitorsareinstalled intheReactorBuildingelevatedreleasedischarge ducttoidentifyandquantifygaseousradionuclide releaseswhichcouldoccurduringnormalandaccidentconditions.

Theseinstruments haveoverlapping rangesandarecharacterized aslow,intermediate andhighrangemonitors.

Theintermediate andhighrangemonitors, whicharegovernedbytheTechnical Specifications, comprisetheReactorBuildingEffluentMonitoring Systemandprovideaccidentmonitoring capability requiredbyRegulatory Guide1.97.Thelowrangemonitor,whichisgovernedbytheOffsiteDoseCalculation Manual,providesmonitoring pursuantto10CFR20and10CFR50requirements fornormaloperation.

9611190144 961108PDRADOCK050003978PDR Page2REACTORBUILDINGEFFLUENTMONITORING SYSTEMOnOctober23,1996at0740hours,intermediate andhighrangestackmonitorsPRM-RE-1B andPRM-RE-1C weredeclaredinoperable andthe72-hourActionStatement wasentered.Thereasonfortheinoperability determination wasthatmonitoroutputhadtrendedupwardtoapproximately 2,000countspersecond(cps)duetoelectronic noiseinterference.

Achemistry sampleofthestackmonitoratmosphere hadbeenobtainedat0550hoursandnonuclideswereidentified inthesamplecount.OnOctober26,1996at0740hours,theReactorBuildingEffluentMonitoring Systemwasinoperable for72hoursrequiring thesubmittal ofthisspecialreport.Thefollowing information isprovidedinaccordance withTechnical Specification Table3.3.7.5-1, ActionStatement 81.AcionTakenl.AWorkRequestwasgenerated andextensive troubleshooting effortswereperformed, withtheassistance ofacontractor, todetermine thecauseoftheintermediate andhighrangemonitorelevatedsignals.2.TheBackupEmergency DoseProjection Systemwasverifiedoperableasthepreplanned alternate monitoring method.Thesystemwasinitiated onOctober26,1996at0700hoursinaccordance withPlantProcedure (PPM)13.8.1,"Emergency DoseProjection SystemOperations."

aueoftheInoerailitThecauseoftheincreased countratewasduetoelectronic noiseinterference.

Duringtroubleshooting efforts,signalsweremonitored anditwasdetermined that60Hznoiseandfrequencies resulting from60Hzspikingweretransmitted ontheshieldcablesoftheradiation monitoring instruments.

Asaresult,themonitoring instruments werecountingsomeofthe60Hzgenerated electronic noisepulsesinadditiontoallofthesignalsgenerated fromtheassociated detectors, suchthatthenoiselevelexceededthecountsfromthedetector.

emStauOnOctober28,1996atapproximately 1800hours,theelectrical interference stopped.Following furtherevaluation, theequipment wasdeclaredoperableat1915hoursonOctober30,1996.Althoughthesourceoftheinterference isunknownatthistime,effortstoresolvetheproblemarecontinuing andbeingtrackedbymeansoftheProblemEvaluation Requestprocess.Inaddition, PlantOperators recordPRM-RE-1B andPRM-RE-1C readingsduringeachshiftinaccordance withPPM3.1.10,"Operating DataandLogs."Oneofthepurposesofthisprocedure istoprovideplantpersonnel withoperating information thatcouldindicatepotential trendsofdeveloping equipment problems.

Page3REACTORBUILDINGEFFLUENTMONITORING SYSTEMFurthercorrective actionsconsistofacontinuing evaluation of:1)thenoiseimmunityoftheradiation monitoring equipment, and2)thesourceoftheelectronic noiseinterference.

Shouldyouhaveanyquestions orrequireadditional information pertaining tothisletter,pleasecontactMs.LourdesFernandez at(509)377-4147.

Restfully~~ViPr,earperations MDropPE23CC:LJCallan,NRC-RIVKEPerkinsJr.,NRC-RIV,WalnutCreekFieldOfficeNSReynolds, Winston&StrawnTGColburn,NRRDLWilliams, BPAMD399NRCSr.ResidentInspector, MD927N