Press Release-92-124, NRC Requests Boiling Water Reactor Licensees Determine Water Level Device Compliance, Press Release-92-124, NRC Requests Boiling Water Reactor Licensees Determine Water Level Device Compliance
| ML003702446 | |
| Person / Time | |
|---|---|
| Issue date: | 08/20/1992 |
| From: | Office of Public Affairs |
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| Category:Press Release "PressRelease-92-124,NRCRequestsBoilingWaterReactorLicenseesDetermineWaterLevelDeviceCompliance" can not be assigned to a declared number type with value 20. "PressRelease" can not be assigned to a declared number type with value -92. | |
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| Press Release-92-124 | |
| Download: ML003702446 (2) | |
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No.92-124FORIMMEDIATERELEASETel.301/504-2240(Thursday,August20,1992)NRCREQUESTSBOILINGWATERREACTORLICENSEESDETERMINEWATERLEVELDEVICECOMPLIANCETheNuclearRegulatoryCommissionstaffhasrequestedutilitieslicensedtooperateboilingwaterreactors(BWRs)to determinepromptlyiftheyareincompliancewithNRCregulations relatedtotheadequacyofreactorvesselwaterlevel
instrumentation.Thestaffisactingonthebasisofitsconclusionthatundersomeunlikelyaccidentconditionstheeffectsof noncondensiblegasinBWRwaterlevelinstrumentsmaycause unreliablelevelindicationandnotsatisfyNRCregulations.
Generaldesigncriteriarequire,inpart,thatreliable instrumentationbeprovidedtomonitorplantsystemsunder accidentsconditionsandthattheeffectsof"naturalphenomena, andofnormaloperating,maintenance,testing,andpostulated accidentconditions...donotresultinthelossoftheprotectionfunction."OnJuly24,theNRCstaffissuedanInformationNoticeadvisingalllicenseesthatnoncondensiblegasesmaybecome dissolvedinapartofBWRwaterlevelinstrumentationandcould resultinafalsehighwaterlevelindicationinthereactor vesselafterarapiddepressurizationaccident.Waterlevel signalsareusedforactuatingautomaticsafetysystemsandfor guidingreactoroperatorsduringandafteranevent.AfterreviewinganalysesprovidedbytheBoilingWaterReactorOwnersgroupataJuly29publicmeetingandassessing selectedaccidentscenarios,theNRCstaffhasconcludedthat interimplantoperationisacceptable.Thereasonsforthe staff'sconclusionarethatautomaticsafetysystemactivationis notinhibitedbythispotentiallevelerror,emergencyprocedures areinplacewhichincludeactionstobetakenforpotential levelerror,anaccidentwhichwouldcausealargewaterlevel errorisremoteandsignificantwaterlevelerroroccurring simultaneouslyinredundantwaterlevelindicatorsisunlikely.However,forlongertermoperationstheNRCstaffconsiderspotentialwaterlevelinstrumentationinaccuraciesanimportant issuebecauselevelindicationhassafetyfunctionsinallmodesofBWRoperation.Further,becausetheanalysesprovidedbythe BWROwnersGrouparegenericandthemagnitudeofpossibleerrors dependsstronglyuponplant-specificfactors,suchassystem leakageandgeometry,theNRCstaffhasrequestedthatthe analysesbereviewedpromptly.Basedonconcernsofpotentialinaccuraciesfromtheeffectsofnoncondensiblegas,BWRlicenseeshavebeenrequested,by letterfromtheNRCstaff,todeterminetheirimpacton:1)automaticsafetysystemresponseduringallreactoreventsandaccidents;2)anoperator'sshortandlong-termactionsduringandafterallreactoreventsandaccidents;and3)operatoractionsprescribedinemergencyoperatingproceduresorotherprocedures.Afterobtainingtheresultsoftheseactions,BWRlicenseesarerequestedtonotifytheNRCofshort-termfixestaken,such asperiodicmonitoringoflevelinstrumentationsystemleakage andimplementationofproceduresandoperatortrainingtoassure thatpotentiallevelerrorswillnotresultinimproperoperator
actions.BWRlicenseesalsohavebeenrequestedtoprovidetheNRCtheirplansandascheduleforcorrectiveactions,includingany proposedhardwaremodificationstoassurethatthelevel instrumentationsystemdesignishighlyreliableforlong-term operations.TheNRCstaffadvisesutilitiestoimplementtheir longertermactionsbeforestartingupafterthenextrefueling outagecommencingthreemonthsafterAugust19.BWRlicenseesarerequiredtoprovidearesponsetoNRCbySeptember27.