ML18037A328

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LER 81-004/01T-0:on 810209,main Steam Radiation Monitor 111 Signal Fluctuated,Causing Multiple Half Scrams.Caused by Loose detector-to-cable Connector.Connector Tightened
ML18037A328
Person / Time
Site: Nine Mile Point Constellation icon.png
Issue date: 02/23/1981
From: HARRISON P
NIAGARA MOHAWK POWER CORP.
To:
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML17053C373 List:
References
LER-81-004-01T, LER-81-4-1T, NUDOCS 8103030757
Download: ML18037A328 (4)


Text

S.NUCLEARREGULATORYCIONQs];NROFORM366I7.771LICENSEEEVENTREPORTrCONTROLBLOCK:pl(PLEASEPRINTORTYPEALLREQUIREDINFORMATION)I6[oD1]NYNMP1Q300-00000-00Q341111Q4~ps789LICENSEECODE1415LICENSENUMBER2526LICENSETYPE3057CAT58CON'TQOB6061DOCKETNUMBER6869FVENTDATE7475REPORTDATE80EVENTDESCRIPTIONANDPROBABLECONSEQUENCES10~o2Durinnormaloerationthe8111MainSteamRadiationMonitorinuttotheRPS~D3TripSystemwasinoperableforapproximately90minuteswhilethe811TripSystemwas~D4leftintheuntrippedcondition.Thisis.contrartotheRPSInstrumentChanneloer-~O5abilityrequirementsasgivenintheTechnicalSpecifications.TheTechnicalSpecifi-~DBcationsreuirethattheTriSstembelacedinthetriedconditionwheneitherof~O7theInstrumentChannelsassociatedwiththatTripSstemisinoerable.Duringthis4timetheredundantmonitorinputto/IllTripSystem,andthetwo(2)(SEEOVER)78980SYSTEMCAUSECAUSECOMP.VALVECODECODESUBCODECOMPONENTCODESUBCODESUBCODE~SHQ33~AQ33~AQ33RE1AYXQ14~XQls~ZQ137891011121318'1920SEQUENTIALOCCURRENCEREPORTREVISIONLER/ROEVENTYEARREPORTNO.CODETYPENO.Q33.Rssosv~81+~004+A~01~T++0ZI222324262728Z930-3I32ACTION.FUTUREEFFECTSHUTDOWNATTACHMENTNPRDMIPRIMECOMP.COMPONENTTAKENACTIONONPLANTMETHODHOURS+2~SUBMITTEDFORMSUB.SUPPLIERMANUFACTURER~XQls~HQ33apso~ZQ330000~YQ33~NQ34~NQ330080Qss3334353637404142434447CAUSEDESCRIPTIONANDCORRECTIVEACTIONS27oThesubdectradiationmonitorsignalhadbeen&luctuatingsufficientlytocausemulti-piespurioushalfscramactuations.Consequently,theSSSgrantedpermissiontoin-stallablockin.theRPSactuationrelayofthesublectmonitor,topreventfurther3spurioushalfscrams,whiletheInstrumenttechnicianwastoproceedwithtroubleUponremoval(SEEOVER).80DISCOVERYDESCRIPTION032SUPERVISIONREVIEW80LOCATIONOFRELEASEN/A80808080NRCUSEONLY44a380a0L6869PHONE:4shootingbywithdrawingthedetectorfromtheholder.789FACILITY~3PMETHODOFSTATUS%POWEROTHERSTATUS~DISCOVERYsEQss~087pssN/A~SQ337891012134445ACTIVITYCONTENTRELEASEDOFRELEASEAMOUNTOFACTIVITY~3~ZQ33~ZQ34N/A789101144'5PERSONNELEXPOSURES789'Il1213PERSONNELINJURIES7891112LOSSOFORDAMAGETOFACILITY4378910PU8LICITYISSUEDDESCRIPTION~DGZLEIS8910~@g~AMSOFPRSPARSR

EVENTDESCRIPTIONANDPROBABLECONSEQUENCESmonitorinputsto//12TripSystemwereoperable,thustherewasnosigni-ficantsafetyconcern.CAUSEDESCRIPTIONANDCORRECTIONACTIONSofthedetector,itwasdiscoveredthatthedetector-to-cableconnectorwasloose,whichwascausingthefluctuatingoutputsignal.Theconnectorwastightened,thedetectorreinstalled,andthemonitorreturnedtonormalindication.The,RPSrelayblockwasthenremoved.AtthistimethePillMainSteamLineRadiationMonitorwasfullyoperable.Inordertopreventoccurrencesofthisnatureinthefuture,severalcorrectiveactionshavebeentaken.First,areviewofthecircumstanceswasmadewiththeshiftpersonnelinvolved.Second,aninstructionhasbeenissuedtoalloperationspersonnelregardingthismatter.Third,procedureschangeshavebeenmadetoensurespecificTechnicalSpecifi-cationreviewsaremadeanddocumentedwhenequipmentimportanttosafetyisremovedfromservice.Fourth,thisincidentandaforementionedpro-cedurechangeswillbeincorporatedintoregularlyscheduledtrainingsessionsforOperationspersonnel.Fifth,trainingsessionswillbeconductedwithintheInstrumentandControlDepartment,regardinginstrumentationimportanttosafetyandtheTechnicalSpecificationsrquirementsingeneral.l8,yJJzofGZ~~3 C