ML17258A570

Forwards Responses to Questions Posed at 760521 Meeting Re Spent Fuel Pool Mod

ML17258A570
Person / Time
Site:	Ginna
Issue date:	08/05/1976
From:	WHITE L D ROCHESTER GAS & ELECTRIC CORP.
To:	SCHWENCER A Office of Nuclear Reactor Regulation
Shared Package
ML17258A569	List: ML17258A568 ML17258A570
References
NUDOCS 8202240227
Download: ML17258A570 (6)

Text

QQCptg>I'pgi;.c.A."ifrE'RiCCOHF'ORAT1CN~S9EA5TAVENUE,ROCHESTER.N.,Y.>>~4~'~,AP'I~.August5,1976A.Schwencer,ChiefOperatingReactorsBranch41DivisionofOperatingReactorsOfficeofNuclearReactorRegulationsU.S.NuclearRegulatoryCommissionWashington,D.C.20555

DearMr.Schwencer:

ThisletterisinresponsetoyourletterofJune24,1976,whichrequestedadditionalinformationregardingourproposedspentfuelpoolmodification.EnclosedpleasefindtheresponsestoyourquestionsandtheresponsestotheStaff'squestionsre-sultingfromtheMay21,1976meetingbetweentheNRCStaffandRG&E.Verytrulyyours,LeonD.White,Jr.LDW/cernEnclosures820224022782021'8PDRADOCN05000244P.PDRJ fp<>

Question15Theproposaltoincreasethestoragecapabilityofthespentfuelstoragepoolfrom210fuelassembliesto595appearstochangethepossibleconsequencesifanobjectsuchasatornadomissileoi.droppedcraneloadimpactsonthestoredspentfuel.Providethefollowingadditionalinformation:RESPONSE:(a)Whatconsiderationhasbeengiventoreducingtheprobabilityorconsequencesofatornadomissileimpactingonstoredspentfuel?Theconsequencesofapostulatedmissileimpactingstoredspentfuelintheproposedracks(595lo-cations)hasbeendecreasedbelowthatoftheexistingracks(210locations)'bypreventingthefuelassembliesinthelatestdischargebatchfrombeingallgroupedtogether.Thefissionproductdensityisgreatestinfuelassembliesthathavetheshortestcooldowntime,assumingsimilarirradiation.Therefore,thestoredfissionproductdensitycanbereducedbysurroundingarecentlydischargefuelassembly'withfuelassembliesthathavebeenstoredforayearormore.Figure15-1illustratesasectionoftheproposedspentfuelstoragerackswiththerecent.discharcrestoredasillustrated.There-mainingstoragelocationswereassumedtobefilledwithfuelassembliesthathavebeenoutofthereactorforoneyear(SeeFigure15-2).ThepossibleconsequencesofapostulatedmissileimpactingstoredfuelwasevaluatedbycomparingthesumofthefissionproductperunitofspentfuelpoolvolumedividedbytheMPCforthatnuclide,orxiMPC~iunitofspentfuelpoolvolumewhere:X.istheifissionproduct..th3.MPC.istheMaximumPermissive3..thConcentrationoftheifissionproduct(10CFR20).15-1 Question15(Continued)Thisquantityweightsthefissionproductdensitysothatthenuclidesmostimportantindosecalculationsaregivenmoreweight.Thisweightingrepresentsamoremeaningfulcomparisonthanifthecomparisonweredoneonfissionproductdensityonly.TheabovequantitywascalculatedfortheexistingspentfuelracksandtheproposedspentfuelrackswiththeloadingpatternillustratedonFigure15-2.Sincethisquantityislessfortheproposedrackandloadingpatternthanfortheexistingracks,theconsequencesofamissilewhichtransversesthesamespentfuelpoolvolumewillalsobelessthanfortheexistingpoolstructure.15-2 Figure15-1ProposedSpentFuelRackWithRecentDischargeStoredAsXllustratedRecentDischargedFuelAssemblyWaterBoxEmptyFuelBox igure15-2OFOFOFOFOFOFOF'FRDF=RecentDischargedFuelOF=OldFuel