ML18040A749

From kanterella
Revision as of 00:33, 18 May 2018 by StriderTol (talk | contribs) (Created page by program invented by StriderTol)
Jump to navigation Jump to search
Forwards Applications for Proposed Amends 57 & 12 to Licenses NPF-14 & NPF-22,respectively.Amends Change Tech Specs to Separate Unit 1 & 2 Battery Loads to Avoid Forced Shutdown of Unit 2 During Unit 1 Refueling Outage
ML18040A749
Person / Time
Site: Susquehanna  Talen Energy icon.png
Issue date: 12/06/1984
From: CURTIS N W
PENNSYLVANIA POWER & LIGHT CO.
To: SCHWENCER A
Office of Nuclear Reactor Regulation
Shared Package
ML17139C742 List:
References
PLA-2370, NUDOCS 8412180621
Download: ML18040A749 (8)


Text

%'C'aPennsylvaniaPower8LightCompanyTwoNorthNinthStreet~Allentown,PA18101~215/770.5151NormanW.CurtisVicePresident-Engineering6Construction-Nuclear215/770-7501DEC61984DirectorofNuclearReactorRegulationAttention:Mr.A.Schwencer,ChiefLicensingBranchNo.2DivisionofLicensingU.S.NuclearRegulatoryCommissionWashington,DC20555SUSQUEHANNASTEAMELECTRICSTATIONPROPOSEDAMENDMENTS57TOLICENSENPF-14AND12TOLICENSENPF-22ER100450PLA-2370DocketNos.50-38750-388

DearMr.Schwencer:

ThepurposeofthisletteristoproposeamendmentstotheSusquehannaSESUnit1andUnit2TechnicalSpecificationsinordertoavoidtheforcedshutdownofUnit2duringtheUnit1firstrefuelingoutage.PROBLEM:SSESUnit2currentlydependsoncertainUnit1125-voltbatteriestosupportcommonloads;theseUnit1batteriesarethereforelistedintheUnit2LCOsonDCsystems.SinceUnit1batteryloadprofiletestingmustbeperformedduringthefirstrefuelingoutage,anACTIONstatementmustbeenteredintheUnit2TechnicalSpecifications.TherequiredtestingwillforcetheshutdownofUnit2,sinceitcannotbeperformedwithinthetwohoursallottedintheACTIONstatement.PROPOSEDSOLUTION:AsinglelinediagramofChannel"A"oftheUnit1125-voltDCsystemisprovidedinFigure1.PP&Lhasdevelopeda.commonloadtransferschemewhichwillallowcommonloadstobepoweredfroma125-voltDCsourceoneitherunitthroughtheuseofmanualtransferswitches(seeFigure2).Inseveralcases,theindividualfeederbreakerssupplynotonlyacommonload,but:alsoaUnit1load(SeeFigure3).Therefore,oncetheloadshavebeentransferredtotheUnit2'source,theUnit1loads(hereinaftercalled"tagalongloads")willbeenergizedfromaUnit2source.Inthereviseddesign,non-Class1EloadswillusuallybetransferredbetweentwodifferentUnit1sources;somewillbetransferredbetweenUnit1andUnit2sources.Inordertomaintaindivision/channelseparationallClass1Eloadsbeingtransferredtosupportthetransferofcommonloads(again,thisincludessometagalongloads)willbetransferredbetweentheUnit1andcorrespondingUnit2battery.80i2i80b2i84i20bPDRADOCK05000l387PPDRAlgC~+fourjP tl4jrillrrfMll'Mrr' HlPage2SSESPLA-2370ER100450File841-8Hr.A.SchwencerPROPOSEDTECHNICALSPECIFICATIONCHANGES:Amark-upofthechangesneededtosupporttheproposedreviseddesignisattached.Fort'eUnit1specifications,thefollowingchangesweremade:pages3/48-10:TheUnit2batteries,fromwhichcommonandtagalongloadsmaynowbepowered,areaddedtotheLCO.AfootnoteisprovidedtoremovethemasanLCOrequirementundersituationswhentheyarenotsupportingUnit1operation.ACTIONawasrevisedtoaffectUnit1equipmentonly.ACTIONbisprovidedoninsertAtocoverthecommonandtagalongloadtransferintheeventthataUnit2batterysupportingUnit1operationisinoperable.'CTION;cisprovided,tocovertherealignmentofUnit1loadsto,theirnormalUnit1sourceoncethatsourcehasbeenrestoredtoOPERABLEstatus.Finally,ACTIONbhasbeenrelettered.P"I4opage3/48-11:ACTIONchasbeenrelettered.opage3/48-12:TheloadprofilefortheUnit1Channel"B"batteryhasbeenrevisedtoprovidemarginforfutureloadadditions,'shouldtheyoccur.InsertBprovidestheloadprofilesfortheUnit2batteriesthatarenowrequiredbytherevisedLCO.opage3/48-15:Seediscussionforpage3/48-10.opage3/48-16:ACTIONScanddhavebeenrelettered.opage3/48-17:Ason3/48-10,requiredUnit2equipmenthasbeenaddedtotheLCOwithafootnotetogovernwhenitisrequiredtosupportUnit1operation.opage3/48-18:Seeabovediscussionon3/48-17.Also,asdiscussedon3/48-10forsources,appropriateACTIONstatementshavebeenproposedoninsertDfortheaffectedDCloadgroups.opage3/48-20:Seediscussionon3/48-17.opage3/48-21:"And/or"hasbeenrevisedtojust"or"forconsistencywiththeLCOrequirementonpage3/48-20.InsertEisprovidedagainforcontrolsovercommonloadtransferandrestorationofnormalalignment.FortheUnit2specificationssimilarchangesweremadetoeachsection.Theonlysignificantdifferencesareontheinserts(AthroughE)whichprovideone,nottwoACTIONstatements.TheACTIONstatementprovidedisdifferentthanthefirstACTIONoneachUnit1insertinthatitdoesnotapplytoanyUnit1(tagalong)loads.ThisisbecauseUnit2requiresonlythecommonloadstosupportitsoperation.ThesecondACTIONproposedintheUnit1insertscoverstherestorationofthenormalUnit1alignmentwithrespecttounitizedloads.SincenoUnit2loads C1il'ifmt1LIII""II'I DEC61984Page3SSESPLA-2370ER100450File841-8Mr.A.Schwencerarebeingtransferredduetothischange,suchanACTIONisnotrequiredintheUnit2specifications.NOSIGNIFICANTHAZARDSCONSIDERATIONS:I.Theproposedchangesdonotinvolveasignificantincreaseintheprobabilityorconsequencesofanaccidentpreviouslyevaluated,forthefollowingreasons:Eachunithasfourindependent125-voltDCpowersources.TheFSARanalysisshowsthataunitcanbesafelyshutdownwithanyone125-voltDCpowersourcedisabled(Section8.3).Basedonthereviseddesign,one125-voltDCsourcewouldfailduetoafaultinaUnit1tagalongloadifbothupstreamprotectivedevices(fuseanddistributionpanelbreaker)failed.ThemorelikelyresultofafaultonaUnit1tagalongloadwouldbelossofanindividualcircuit.Therefore,themostprobablefailureislessseverethanthelossofanentirepowersource,whichhasbeenpreviouslyevaluated.Finally,theUnit2batterieshavebeenanalyzedanddohavesufficientstoredenergytooperateallnecessaryloadsforthedesignbasisintervaloffourhours,afterlossofACpowerandassumingthelossofthebatterycharger.II.Theproposedchangesdonotcreatethepossibilityofanewordifferentkindofaccidentfromanyaccidentpreviouslyevaluated.Asstatedabove,theprobablefailureasaresultofthereviseddesigniswithintheboundsofthepreviousFSARanalysis,andbatterycapacityissufficienttomeetdesigncommitments.Thereforenonewordifferentpossibilityexist.III.Theproposedchangesdonotinvolveasignificantreductioninamarginofsafety.Basedontheexistenceofsufficientbatterycapacity,theincreasedreliabilityofUnit1duetocontinuityofp'ower,andthefactthattheworstcasefailureduetothenewdesignisconsistentwithpreviousanalysis,onecanconcludethattheexistingmarginofsafetyhasnotbeenreduced.Basedupontheconsiderationspresentedabove,thischangeappearstofallunderanexampleasstatedin48FR14870,Column3,paragraph(vi).PPSLdoesnotethatthischangepresentsadeviationfromourpreviousFSARcommitmentstoRegulatoryGuide1.81,anduponapprovalofthischangewewilltaketheappropriatestepstorevisetheFSARaccordingly.

~>~~V'I DEC61984Page4SSESPLA-2370ER100450File841-8Mr.A.SchwencerIMPLEMENTATIONSCHEDULE:Asstatedatthebeginningofthisproposal,themostimmediateproblemwhichisbeingavoidedasaresultofthischangeistheshutdownofUnit2duringtheUnit1firstrefuelingoutage.Therefore,itisimperativethatPP&Lreceiveapprovaloftheproposedchangepriortoorveryearlyintotheoutagesothatbatteryloadprofiletestingcanproceedonscheduleandasaresultofthismodification,notforcetheshutdownofUnit2.Theappropriatefeespursuantt'o10CFR170.22havebeenenclosed.AnyquestionsonthismattershouldbedirectedtoMr.R.Sgarroat(215)770-7855.Wearewillingtomeetwithyouatyourconveniencetofurtherdiscussthismatter.Verytrulyours,N.W.CurtisVicePresident-Engineering&Construction-NuclearEnclosurescc:M.J.CampagnoneUSNRCR.H.JacobsUSNRCT.M.Gerusky,DirectorBureauofRadiationProtectionPa.Dept.ofEnvironmentalResourcesP.0.Box2063Harrisburg,PA17120 4~PH~IH\P~'!IIIeHTHIgtt;*rerHT~p"'llPPI~I~~I'~~~HlP~r~PIedIP