ML17037C261

Nine Mile Point Unit 1 - Letter Responding to a Request for Additional Information Concerning the Drywell Vacuum Breakers

ML17037C261
Person / Time
Site:	Nine Mile Point
Issue date:	07/20/1973
From:	Schneider R R Niagara Mohawk Power Corp
To:	Skovholt D J US Atomic Energy Commission (AEC)
References
Download: ML17037C261 (10)

Text

.AECDISBUTIONFORPART50DOCKETMA~AL'TEMPORARYFORM)CONTROLNO:PILE:'RON:NiagaraMohawkPowerCorporationSyracuse,N.Y.13202R.R.Schneider'-20-737-25-73DATEOFDOCDATEREC'DMEMORPTOTHERTOvhCLASSUNCLASSXXPROPINFOORIG3si~nedINPUTCCOTHERNOSREC'D40SENTAECPDRXSENTLOCALPDRXDOCKETNO:50-220DESCRIPTION:LtrfurnishingrequestedinforedrywellvacuumbreakersattheNineMilePointNuclearStationUnit0l.......PLANTNAME..NineMilePointUnit81ENCLOSURES:NQJil/>gggDo,go<Remove~t~FORACTION/INFORMATION7-25-73ABBUTLER(L)W/CopiesCLARK(L)W/CopiesGOLLER(L)W/'CopiesKNIEL(L)W/CopiesSCHWENCER(L)W/CopiesSTOLZ(L)W/CopiesVASSALLO(L)W/'CopiesSCHEMEL(L)W/CopiesNIEMANN(L)W/6CopiesDICKER(E)W/CopiesKNIGHTON(E)W/CopiesYOUNGBLOOD(E)W/CopiesINTERNALDISTRIBUTIONREGAN(E)W/CopiesW/Copies'W/CopiesW/CopiesGPIROGC,ROONP-506A~MUNTZING/STAFFCASEGIAMBUSSOBOYDMOORE(L)(BWR)DEYOUNG(L)(PWR)~SKOVHOLT(L)P.COLLINSREGOPR~ILE&REGION(3)MORRISSTEELETECHREVIEWHENDRIESCHROEDERMACCARYKNIGHTPAWLICKISHAOSTELLOHOUSTONNOVAKROSSIPPOLITO~TEDESCOLONG~LAINASBENAROYAVOLIMERDENTONGRIMESGRMILL'ASTNERBALLARDSPANGLERENVIROMULLERDICKERKNIGHTONYOUNGBLOODREGANPROJECTLDRHARLESSLICASSTBR(MN(E)DIGGS(L)GEARIN(L)GOULBOURNE(L)LEE(L)MAIGRET(L)SERVICE(L)SHEPPARD(E)SMITH(L)TEETS(L),WADE(E)WILLIAMS(E)WILSON(L)A/TINDBRATIMANSALTZMANPLANSMCDONALDDUBEINFOC.MILES~J.RIESLANDW.BUTLER+STOLZCLARKEXTERNALDISTRIBUTION~l<<LOCALPDR~1-DTIE(ABERNATHY)(l)(2)(9)-NATIONALLAB'S~-NSIC(BUCHANAN)'1-R.Schoonmaker,OC,GT,D-3231-ASLB(YORE/SAYRE/1-R.CATLIN)E-256-GTWOODARD/"H"ST.1-CONSULTANT'16-CYSACRSHGMRHGSENTTOLICASST.NEWARK/BLAT/AGBABIANR.DIGGSON7-25-.733."GERALDULRIKSON~ORNL1-PDR-SAN/LA/K(1-GERALDLELLOU0BROOKHAVENNAT.LAB1-AGMED(WALTERKOESTERRM-C-427"GT1-RDMULLER.F-309GT Cot~tl,I'

.AeIYutatory'NIAGARAMOHAWKPOWERCORPORATIONNIAGARA~MOHAWK300ERIEBOULEVARDWESTSYRACUSE,NY.l3202July20,1973~III'r"gJulg5)gg~

DearMr.Skovholt:

Re:ProvisionalOperatingLicense:DocketNo.:50-220DPR-17Mr.DonaldJ.SkovholtAssistantDirectorforReactorOperationsDivisionofReactorLicensingUnitedStatesAtomicEnergyCommissionWashington,D.C.20545O0,<<~)8jpjogg6'OIIQggIIIIII~idltlfRegardingyourletterrequestingadditionalinformationconcerningthedrywellvacuumbreakersatNineMilePointNuclearStationUnit81,thefollowingissubmitted:ITEM1Thepresentpositionindicatingsystemutilizestwosetsoflimitswitches,thesnaplocklimitswitchmanufacturedbytheNationalAcmeCompanyandtheHoney-wellModelDTE6-2RNheavyduty,microswitches.Thesnaplocklimitswitchisusedtodetermineandindicatetheopenpositionofanyonevalve'tothecontrolroom.TheHoneywellmicroswitchisusedtodetermineandindicatetheclosedpositionofanyonevalvetothecontrolroom.ThissystemwasreviewedduringtheSpring",.I973refuelingoutageandtheHoneywellmicroswitchesinstalledatthattime.Sincethepurposeoftheselimitswitchesistoprovidethecontrolroomoperatorwithinformationregardingthepositionofthebreakervalves,physicalseparationofthecontrolwiringorindicatinglightsisnotrequired.However,anadditionalHoneywelllimit,switchwillbeinstalledtodetecttheclosedpositionandprovideanalarmtothecontrolroomintheeventanydrywellvacuumbreakervalvemovesoffitsseatapredeterminedamount.RedundancesinthealarmcircuitwillthusbeprovidedandIEEE279criteriasatisfied.ThepretravelontheHoneywell'switchis.065"maximumandmeasurementshaveshownthemtobe.04"ofpretravel.Thevacuumbreakerpositionisdetectedbythoselimitslvitchesandareactuatedbysmallarmsattachedtothevalveshaft.Thediscmusttravelapproximately.2"beforeactuationofthelimitswitchisachieved.Thlerefore,thefullpotentialaccuracycannotberealizedduetotheexistingmountingoftheswitches.At,thepresenttime,thesystemisunderastaffreviewtodeterminewhatmustbedonetoachievethedesiredaccuracyof.05"-.06"ofdiscmovement.Thisreviewshouldbecompletedwithinamonthandactualimplimentationswilltakeplace,afterappropriatereviews,within30-60days.Thedrywellvacuumbreakersarecompletelyaccessibleduringthe II Mr.DonaldJ.SkovholtUnitedStatesAtomicEnergyCommissionPage27/20/73poweroperatingconditionandthusonlinemodificationscanbemade.Untiltheaccuracyof.05"-.06"discopeningcanbemetandthealarmredundancycompletedthefollowingwillbedone:a.Eachreactortransientinvolvingthesuppressionchamberwillbefollowedwithanoperabilitytestofthedrywellvacuumbreakervalves.b.Adialindicationwillbeinstalledoneachvalveaccuratetoindicate.06"move-mentofthedisc.ThissystemwillprovideadailysurveillanceofvalveclosurewithintheacceptablelimitsasinITEM3below.TheseindicatorswillbeinstalledpriortoAugust1,1973.'ITEM2Duringthevalveoperabilitytest,whenairisreleasedfromtheairtestcylinderthevalverapidlyclosesleavingoperatingpersonnelnoactiontotaketomanuallyclosethevalve.However,toprecludeagainstmanualclosure.ofthevalvefollowingtestingamanagementpersonwillbemonitoringthetestingatthetestsite(i.e.thevalvelocation)to:assurethatnomanualinterventiontakesplace.SeeItem1responseregardingvalveoperabilitytestandotheradditionalsurveillancetobedoneuntilITEM1iscompliedwithinfull.ITEM3Thelimitoneachindividualvalvewillbesetsuchthatwithallvalvesattheirlimitthemaximumvalueofcumulativeleakagewillnotexceedthemaximumallowable.Thevaluewillbeapproximately.06"ofdisc'raveloff.itsseatandwillbealarmedin.the,controlroom.Thetorusinstrumentsthatwouldbeusedforsurveillancetestingandleakratetestingofthedrywellvacuumbreakervalvesreadoutintheauxilarycontrolroom.Theirrangeandaccuracyareasfollows:Pressure:0-50psia+.05psi.Temperature:0-200'F+1'FPSID0-1.0psid+.001psiTheinstrumentationusedbytheoperatorduringanLOCAareinthecontrolroomandincludenotonlyanindicatedpressureinstrumentbutarecorderaswell.Theirrangeandaccuracyisasfollows:Pressure:low0-4psig+.1psihigh0-75psig+1.5psiTemperature:50-300'F+5'FThecomputer.alsorecordsthedrywellandpressuresuppressionchamberpressureandtemperatureasfollows:

e~~PP Mr.DonaldJ.SkovholtUnitedStatesAtomicEnergyCommissionPage37/20/73Pressure:0-40psig+.1psi-alarmat2.5psigTemperature:50-300'F+1'Falarmat100'FTorus,120'FDrywellITEM4Td'chnicalSpecificationConsiderationsProposedTechnicalSpecificationswillbesubmittedseparately,afterthenecessaryreviewsarecomplete.Considerationis,beinggiventoaddingthefollowingconditionsandsurveillancerequirements.LimitingConditionsforOperation3.3.6DrywellPressureSuppressionChamberVacuumBreakersa.lienprimarycontainmentisrequired,alldrywell-suppressionchambervacuumbreakersshallbeoperableandpositionedintheclosedpositionasindicatedbythepositionindicationsystem,exceptduringtestingandexceptasspecifiedin3.3.6bandc,below.b.Anydrywell-suppressionchambervacuumbreakermay.=benon-fullyclosedasindicatedbythepositionindicationsystemprovidedthatadrywelltotoruspressuredifferentialcanbemaintainedgreaterthan1/2theinitialdifferentialpressurefor1hourwithnoN2makeup.c.Uptoonedrywell-suppressionchambervacuumbreakermaybesecuredintheclosedposition.d.IfSpecifications3.3.6a,borccannotbemet,thesituationshallbecorrectedwithin24hoursor.thexeactor.shallbeplacedinacoldshut=downconditionwithin24hours.SurveillanceRequirements4.3.6Drywell-PressuxeSuppressionChamberVacuumBreakersa.Eachdrywell-suppressionchambervacuumbreakershallbeexercisedthroughanopening-closingcyclemonthly.b.1&enitisdeterminedthatanyvacuumbreakervalveisnotfullyclosedasindicatedbythepositionindicationsystematatimewhensuchclosureisrequired,theapparentlymalfunctioningvacuumbreakervalvesshallbeexercisedandpressuretestedasspecifiedin3.3.6bimmediatelyand"every15daysthereafteruntiltheapparentlymalfunctioningvalveshavebeenreturnedtonormalservice.c.Onceeachoperatingcycle,eachvacuumbreakervalveshallbevisuallyinspectedtoensurepropermaintenanceandoperation.

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her.,DonaldJ.SkovholtUnited'tatesAtomicEnergyCommissionPage47/20/73d.Aleaktestofthedrywelltosuppressionchamberstructureshallbeconductedduringeachrefuelingoutage.Nebelievethisreporttoberesponsivetoallitemsenumeratedinyourletter.Verytrulyyours,1e1eVicePresident-ElectricOperationsRRS:pw-00'I4