ML17331A296

Suppls 920515 Ltr Re Status of Mod of Commitment Re Control Room Habitability,Per GDC 19.Damper No Longer Being Maintained Closed.Ts Changes & Supporting Analyses Associated W/Control Room Habitability Will Be Submitted

ML17331A296
Person / Time
Site:	Cook
Issue date:	04/26/1993
From:	FITZPATRICK E INDIANA MICHIGAN POWER CO. (FORMERLY INDIANA & MICHIG
To:	MURLEY T E NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
AEP:NRC:0398Y, AEP:NRC:398Y, NUDOCS 9305030341
Download: ML17331A296 (5)

Text

ACCELERATED DOCUMENTDISTRIBUTION SYSTEMREGULATINFORMATION DISTRIBUTIO1YSTEM (RIDE)ACCESSION NBR'.9305030341 DOC.DATE:

93/04/26NOTARIZED:

NODOCKETFACIL:5Q.-315 DonaldC.CookNuclearPowerPlant,Unit1,IndianaM0500031550-316DonaldC.CookNuclearPowerPlant,Unit2,IndianaM05000316AUTH.NAMEAUTHORAFFILIATION FITZPATRICK,E.

IndianaMichiganPowerCo.(formerly Indiana&MichiganEleRECIP.NAME RECIPIENT AFFILIATION MURLEY,T.E.

DocumentControlBranch(Document ControlDesk)I

SUBJECT:

Suppls920515ltrrestatusofmodofcommitment recontrolroomhabitability,per GDC19.Damper neednolongerbemaintained closed.TS changesssupporting analysesassociated w/control roomhabitability willbesubmitted.

DISTRIBUTION CODE:A003DCOPIESRECEIVED:LTR iENCL0SIZE:TITLE:OR/Licensing Submittal:

Suppl1toNUREG-0737(Generic Ltr82-33)NOTES:DRECIPIENT IDCODE/NAME PD3-1LADEANFWINTERNAL:

NR/JVRHHFBllEXILE01EXTERNAL:

NRCPDRCOPIESLTTRENCLRECIPIENT IDCODE/NAME PD3-1PDOC/LFMBRES/DSIR/EIB NSICCOPIESLTTRENCLDDDNOTETOALL"RIDS"RECIPIENTS PLEASEHELPUSTOREDUCEWASTE!CONTACTTHEDOCUMENTCONTROLDESK,ROOMPl-37(EXT.504-2065)

TOELIMINATE YOURNAMEFROMDISTRIBUTION LISTSFORDOCUMENTS YOUDON'TNEED!TOTALNUMBEROFCOPIESREQUIRED:

LTTR10ENCL AmericanElectricP~ServiceCorporation~

1Riverside PlazaColumbus, OH432154142231000SlNMICQNKI.MTQICIrWMAEP:NRC:0398Y DonaldC.CookNuclearPlantUnits1and2DocketNos.50-315and50-316LicenseNos.DPR-58andDPR-74MODIFICATION OFCOMMITMENT REGARDING CONTROLROOMHABITABILITY U.S.NuclearRegulatory Commission DocumentControlDeskWashington, D.C.20555Attn:T.E.MurleyApril26,1993

DearDr.Murley:

InourletterAEP:NRC:0398W, datedMay15,1992,weprovidedtheNRCwithinformation onmeasureswehaveimplemented attheDonaldC.CookNuclearPlantinordertobringthecontrolroomventilation systemsmoreincompliance withtheNRC'sinterpretation ofthedoselimitsof10CFR50AppendixAGeneralDesignCriteria(GDC)19.Thisletterprovidesanupdatedstatusregarding thosemeasures.

InAEP:NRC:0398W, wecommitted tomaintaining the(non-redundant) normalintakeisolation damperinaclosedposition, andtolimitallowable airintakeratessuchthatthewholebodyandthyroiddoseswouldbewithintheStandardReviewPlancriteriaof5and30rem,respectively.

(Thesemeasureswouldresultinacorresponding skindoseofapproximately 32rem,whichwaswithin7%ofthe30remStandardReviewPlanlimit.)Maintaining thenormalintakeisolation damperclosedeliminated theneedtoaccountforthepossiblefailureofthisdamper,andthusreducedthecalculated doseeAlthoughthecontrolzoomremainedhabitable fromanenvironmental perspective withthenormalintakeisolation damperclosed,thiswasnotadesirable longtermsolutionsinceitdoeslimittheamountoffreshairthatentersthecontrolroomduringnormaloperations.

Inordertoreducethecalculated dosesandtherefore demonstrate compliance withtheStandardReviewPlandosecriteriawithoutrelyingonmaintaining thenormalintakeisolation damperclosed,weobtainedtheservicesofameteorological consulting firmtoprovideaplantspecificdetermination oftheatmospheric dispersion term(Chi/Q)thatisusedintheanalytical model.Theplantspecificevaluation resiilted inaninetyfifthpercentile Chi/Qof~I<<t930503034i

<930426PDRADOCK05000315PDR' "iEl,'I~

Dr.T.E.MurleyAEP:NRC:0398Y 7.85E-4sec/m3,versusthepreviousvalueof2.41E-3sec/m3whichhadbeenderivedusingthegenericmethodology referenced intheStandardReviewPlan.Sincecalculated dosesaredirectlyproportional toChi/Q,thenewlycalculated dosesareonlyonethirdoftheprevious.

Theconsultant's reportisavailable forauditattheAEPSCofficesinColumbus, OHandattheCookNuclearPlant.Thereduction indoseenablesustoaccommodate afailureofthenon-redundant normalintakeisolation dampertoclosewhilestilldemonstrating compliance withtheStandardReviewPlandoselimitsdose,providedappropriate limitsonairintakeareapplied.(Inaccordance withtheguidanceofSection6.4oftheStandardReviewPlan,thedamperisassumedtobeclosedmanuallytwohoursaftertheaccident.)

Therefore, thisdamperneednolongerbemaintained closed.LimitswillbeappliedtoairintakeratessuchthattheStandardReviewPlandoselimitsforwholebody,thyroid,andskindosesaremet.Itisourintenttosubmitproposedtechnical specification changes(andthesupporting analyses) associated withcontrolroomhabitability.

Thiswillbethesubjectofseparatecorrespondence.

Sincerely, ee~~qE.E.FitzatrickVicePresident drcc:A.A.Blind-BridgmanJ.R.PadgettG.CharnoffA.B.Davis-RegionIIINRCResidentInspector

-BridgmanNFEMSectionChief

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