ML17266A398

LER 80-071/03L-0:on 801231,during Operation at 100% Power, Vol Control Tank Inadvertently Diluted,Leading to RCS Dilution,Increasing Power Above Tech Specs Limit.Caused by Failed Crosby Relief Valve V2173 on Acid Pump Discharge

ML17266A398
Person / Time
Site:	Saint Lucie
Issue date:	01/29/1981
From:	PACE P L FLORIDA POWER & LIGHT CO.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML17209A641	List: ML17209A640 ML17266A398
References
LER-80-071-03L, LER-80-71-3L, NUDOCS 8102180653
Download: ML17266A398 (3)

Text

NACFORMSSSPTTIt.lCEiNSEEEVCIMTREPORTU.SNUCl.SARREGULATORYCOMMISSIONCONTROLSLOCIKIIII!QI(PLEASEPAINTOATYPEALl,A'EOUIRKDINPOAMATIONII~FILIALEIIIQ001-001010101.00Q411IIIIIQ~Q49UCKNSKSCOOKLICSiu$4EEIUMBERlSTSL;CL'4$4TYPEl0ST~T$4CCN'T0I2RKPQATLLLQS05i00i[!QT404IQOCXETNVMSSR49SVSNTOKSCRIPTIONANOPROSASL,SCO44SSOUSEHCSSQIOOurinnormaloerationat100Kowr,Q8IO!40ll2IIQ>IinadIFertentldilutedleadintIcatedreactorowerincreasedoverabout15mini~Qls,lTcalsoincreaseddurinthetransientreachin5425thes~a>>l.imitis542f.ActionerT.S.3.2.5.u(astakenanddCOMP,VALVECCMPONENTCQQKSVSCQQS'VBCQOS8WXQISmQISI9OCCUAAKiICSREPORTREVISION'QQETYPE~NO.L~JLaic~L3-laJl3*T.ACNMSAT'IPPIO44PRIMECOMP.COMPONENT22SVSMITTEOPOAM$US.SVPPUKRMANUSACTUAKRLueLJOIISLOcFSeg4143444TSYSTEMCAVS4CAVSSCQSCOOKSUSCCOSELLLieIFJSLEJQ14910IIISISSSQUSNTI*lLERIROeVKNTYSAAASPORTNO.Qi;~EFEFEF~BPTITT2334TS4'CHPUTUAKEJPEC.SNVTQCWNSE~ACTIONCNPLANTMKTIIQOHQVAS'SLJSLJSLJOCALSSOKSCRIPTlONANOCORRSCilVSACTIONSQ2loI!Mhileaddinmakeuandd'0~or!reduced.Thisisthefirsteventofthiste.~04T3!reliefvalveV2173CrosbstleJR-MR-SailedreturninboricluostreamfromthereliefwasnormalTandlaterreaired.~AQSIn>>'MES~i<S~ET43IOI'3IS44~EnTYCNTS.'IT~SLe~ioQPRELEASEAMOUNTOPACTIVITYQSS~I!>>~ZQSS~ZQ24NAT3IOIIPSRSONNKEXPOSURESNUMSERQSSCAIPTION2L00000'Q>>~ZLQEqlAT5III'3ISP$1$CNNSLINlURIK3~LBOOOIQ$$QPCAOAMAQS,QPAOLITYQ42SSQESCRIPTIQN~ZQ42NAT43'gPUBLIC:~0.ISSUSOQESCRiPT:QNS~20LNIQ~NA4445IO810218OI'P53.NAMAOPPREPARERP.L.Pace.4saCIIL'~~20MKTIIOOQP$.ATUS-eiPOWEROTIIKRSTATUSQCISCOVERY40I4040NRCUSEONLY443930(305)552-3801QISCOVKRY0ESCALATICNQS20eratorObservationLOCATIONOPRELEASEQ2NA REPORTABLEOCCURRENCE335-80-.71LICENSEEEVENTREPORTPAGETWOADDITIONAICAUSEDESCRIPTIOflThecharginopumps';whichtakesuctionontheYCT,pump..bora'tedwater~intotheRCSforboronconcentrationcontrolandmakeup.llhileblendingboricacidandwatertotheVCTtoslightlydilutetheRCSandaddmake-up',areliefinthelinetotheblendingvalvefailed.Thisreturnedtheboricacic.'otheboricacidmakeupf'inkinsteadofintotheVCT.ThisresultedinthedilutionoftheVCTandthereforethedilutionoftheRCZ.Theplantisdesignedtosafelyaccomodatethistransientbuttheeventispotentiallysignificantduetothemisleadingindicationgiven.Thereliefvalveisdownstreamfromtheboricacidflowelementsotheoperatorshadindicationof'anormalblendtotheVCT.Duetothesmallamountofacidinvolved(afewgallons)andthelargeboricacidtanksize(8,000gallons),tankleveldidnotrespondwithnotice-ableindication.Increasingpowerwasthefirstindicationofthetransientandthecausewasnotreadilyapoarent.SincedilutionviatheVCTisaslowprocess,thetransienthadbeeninorogressforseveralminutesbeforetherewasanyindication.Analternateboroninjecticnpathwasusedtoreducepower.Thereliefwasdisassembledandfoundtohaveacutseatandabentstem.Thseatwasrepairedandthestemreplaced.Thebentstemwastherootcauseofthedilution.Howthestembecamebentisunknown.AreviewbyPlantOperatorsofthisLERandoftheproperactionstaken,willincreaseawarenessofthisproblemandwillhelptheoperatortodealwithsimilarevents,shouldtheyoccurinthefuture.

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