ML17037C144

Nine Mile Point Unit 1 - Letter Reporting That the Nine Mile Point Reactor Was Scrammed from 25 Percent Power on November 20, 1969 and Advising That the Reactor Will Be Brought Critical and the Turbo-Generator Set Placed on the Line on Dece

ML17037C144
Person / Time
Site:	Nine Mile Point
Issue date:	12/06/1969
From:	Burt P A Niagara Mohawk Power Corp
To:	Morris P A US Atomic Energy Commission (AEC)
References
Download: ML17037C144 (4)

Text

l>X>IllKL4MO><<.-,>~W%~I~I/DOCKETEDUSAECDECB1969~-gREGUlATORYNlLSECTIONDOCKETCLERK'>>o'o>)'RegulatoryNineMilePointNuclearStationP.0.Box32.Lycoming,NewYork13093December6,1969NIAGARAMOHAWKPOWERCORPORATION,i>>(I'W;,NIAGARA"~MOHAWKFileCy;,UnitedStatesAtomicEnergyCommissionDivisionofReactorLicensingWashington,D.C.20545Attention:Dr.PeterA.Morris,DirectorGentlemen:OnThursday,'ovember20,1969,theNineMilePointreactorwasscrammedfrom25percentpower.Thirtycontrolrods,whichwerehookeduptoabrushrecorder,averaged4.17secondsfor90percentinsertion.Theoriginal90percentinsertiontimeforALLrodswas3.00seconds.Duringtheapproximatesix-weektimeintervalbetweentheoriginalandNovember20thscrams,eightdriveswerecontinuouslymonitoredforspurious.aswellasplannedscrams.Theirtimesfor90percentinsertionincreasedapproximately40percentduringthemonitoringperiod.DuringtheNovember20thscram,onerodwasoutsidetheTechnicalSpecificationlimitof5.3seconds;RodNo.24-23scrammedin5.32seconds.InasmuchasexcessiverodinsertiontimewasexperiencedatOysterCreekduetopartiallyplugged400meshinnerroddrivestrainersandtherateatwhichourtim-ingwasincreasinggavecausetosuspectournextscrammightbeabovetheTechnicalSpecificationlimi.tof5secondsaverage,itwasdecidedtochangeoutthestrainers.Ascreenhavingclearrectangularopeningsof10by100milswasinstalledinplaceoftheoriginal400UnitedStatesstandard.mesh.Inthismanner,thedriveisprotectedwhiledecreasingscreenpluggageprobabilitybyanorderofmagnitudeofapproximately400times.Theworkwascompleted,includingdrivetiming,onDecember6,1969.Atthislimeallrodshavebeenscramtestedundercoldpressur-izedconditionswithanaverage90percentinsertiontimeof2.7seconds.IYhenthereactorreachesoperatingpressureandtemperatureandwithapproximately5percentbypasssteamtothecondenser,allrodswillbeindividuallyscramtested.Neshallcontinuetohonorcommitmentspreviouslymadeofreportingrodswhose90percentinsertiontimedonotfallwithintherangeof1.9to3.6seconds,also,iftheaverage'f129rodsisnotwithintherangeof2.4to3.1seconds.Thesameeightdrivesasbeforewillcontinue'tobeconstantlymonitoredandscramcheckedonceeverytwoweeksshouldascramnotoccurinthatperiod.Inaddition,theywillbesimilarlytestedbeforeplannedscramsfrom50percentpower.Feed-waterqualitywillbecontrolledatalltimesandespeciallymonitoredwhenimpuri-tiesmightbeadded,suchaswhencuttinginfeedwaterstrings,newpumps,pipingsystems,andsoon.

'I4,Pe1' UnitedStatesAtomicEnergyCommissionPage2December6,1969Thefollowingchemistrysurveillanceisperformedandwillcontinuetobeinordertoevaluatethecrudintroducedintothereactorwater:l.A24-hourintegratedcrudsampleistakenonthefeedwaterenteringthereactorandanalyzeddaily.Thissampletapislocatedsothatitsamplesthefeedwaterjustbeforethereactorregardlessoffeed-waterpathused.2.Acontinuouslyrecordingturbidimeterisinstalledonthereactorfeedwatertogiveassi.stanceinevaluatingtrends.3.Adailygrabsampleforcrudistakenonthereactorwater.4.i&eneitherconductivityortheturbidimeterindicatethatacon-densatedemineralizershouldbechanged,theoperatingdemineralizeroutputs'willbeevaluatedforbothconductivityandcrudtodeter-minewhichbedorbedsshouldbeswitched.5.Everyeffortwillbemadetokeepfeedwatercrudlevelslowbyfrequentchangingofdemineralizersandbyreductionofflowthroughthedemineralizerswherenecessary.6.i&ennewpartsofthefeedwatercyclearebeingcutintoservice,everyeffortwillbemadetorecirculateasmuchcondensatebacktothecondenser,therebypolishingitthroughthedemineralizersatahigherrate.ItisexpectedthattheNineMilePointreactorwillbebroughtcriticalandtheturbo-generatorsetplacedonthelineonDecember8,1969.Duringthefollowingweek,additionalfeedwaterheaterswillbebroughtintoserviceandpowerraisedtothe50percentlevel.Verytrulyyours,P.AllisterBurtStationSuperintendentmjscc:Mr.M.H.PrattMr.F.J.SchneiderMr.J.N.Ewart,Chairman,SR5,ABoardMr.M.Hildr'eth,A.E.C.Compliance h.~Ih~,~0~