ML18040A749

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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'aPennsylvania Power8LightCompanyTwoNorthNinthStreet~Allentown, PA18101~215/770.5151 NormanW.CurtisVicePresident-Engineering 6Construction-Nuclear 215/770-7501 DEC61984DirectorofNuclearReactorRegulation Attention:

Mr.A.Schwencer, ChiefLicensing BranchNo.2DivisionofLicensing U.S.NuclearRegulatory Commission Washington, DC20555SUSQUEHANNA STEAMELECTRICSTATIONPROPOSEDAMENDMENTS 57TOLICENSENPF-14AND12TOLICENSENPF-22ER100450PLA-2370DocketNos.50-38750-388

DearMr.Schwencer:

Thepurposeofthisletteristoproposeamendments totheSusquehanna SESUnit1andUnit2Technical Specifications inordertoavoidtheforcedshutdownofUnit2duringtheUnit1firstrefueling outage.PROBLEM:SSESUnit2currently dependsoncertainUnit1125-voltbatteries tosupportcommonloads;theseUnit1batteries aretherefore listedintheUnit2LCOsonDCsystems.SinceUnit1batteryloadprofiletestingmustbeperformed duringthefirstrefueling outage,anACTIONstatement mustbeenteredintheUnit2Technical Specifications.

TherequiredtestingwillforcetheshutdownofUnit2,sinceitcannotbeperformed withinthetwohoursallottedintheACTIONstatement.

PROPOSEDSOLUTION:

AsinglelinediagramofChannel"A"oftheUnit1125-voltDCsystemisprovidedinFigure1.PP&Lhasdeveloped a.commonloadtransferschemewhichwillallowcommonloadstobepoweredfroma125-voltDCsourceoneitherunitthroughtheuseofmanualtransferswitches(seeFigure2).Inseveralcases,theindividual feederbreakerssupplynotonlyacommonload,but:alsoaUnit1load(SeeFigure3).Therefore, oncetheloadshavebeentransferred totheUnit2'source,theUnit1loads(hereinafter called"tagalongloads")willbeenergized fromaUnit2source.Inthereviseddesign,non-Class 1Eloadswillusuallybetransferred betweentwodifferent Unit1sources;somewillbetransferred betweenUnit1andUnit2sources.Inordertomaintaindivision/channel separation allClass1Eloadsbeingtransferred tosupportthetransferofcommonloads(again,thisincludessometagalongloads)willbetransferred betweentheUnit1andcorresponding Unit2battery.80i2i80b2i 84i20bPDRADOCK05000l387 PPDRAlgC~+fourjP tl4jrillrrfMll'Mrr' HlPage2SSESPLA-2370ER100450File841-8Hr.A.Schwencer PROPOSEDTECHNICAL SPECIFICATION CHANGES:Amark-upofthechangesneededtosupporttheproposedreviseddesignisattached.

Fort'eUnit1specifications, thefollowing changesweremade:pages3/48-10:TheUnit2batteries, fromwhichcommonandtagalongloadsmaynowbepowered,areaddedtotheLCO.AfootnoteisprovidedtoremovethemasanLCOrequirement undersituations whentheyarenotsupporting Unit1operation.

ACTIONawasrevisedtoaffectUnit1equipment only.ACTIONbisprovidedoninsertAtocoverthecommonandtagalongloadtransferintheeventthataUnit2batterysupporting Unit1operation isinoperable.'CTION;c isprovided, tocovertherealignment ofUnit1loadsto,theirnormalUnit1sourceoncethatsourcehasbeenrestoredtoOPERABLEstatus.Finally,ACTIONbhasbeenrelettered.

P"I4opage3/48-11:ACTIONchasbeenrelettered.

opage3/48-12:TheloadprofilefortheUnit1Channel"B"batteryhasbeenrevisedtoprovidemarginforfutureloadadditions,

'shouldtheyoccur.InsertBprovidestheloadprofilesfortheUnit2batteries thatarenowrequiredbytherevisedLCO.opage3/48-15:Seediscussion forpage3/48-10.opage3/48-16:ACTIONScanddhavebeenrelettered.

opage3/48-17:Ason3/48-10,requiredUnit2equipment hasbeenaddedtotheLCOwithafootnotetogovernwhenitisrequiredtosupportUnit1operation.

opage3/48-18:Seeabovediscussion on3/48-17.Also,asdiscussed on3/48-10forsources,appropriate ACTIONstatements havebeenproposedoninsertDfortheaffectedDCloadgroups.opage3/48-20:Seediscussion on3/48-17.opage3/48-21:"And/or"hasbeenrevisedtojust"or"forconsistency withtheLCOrequirement onpage3/48-20.InsertEisprovidedagainforcontrolsovercommonloadtransferandrestoration ofnormalalignment.

FortheUnit2specifications similarchangesweremadetoeachsection.Theonlysignificant differences areontheinserts(AthroughE)whichprovideone,nottwoACTIONstatements.

TheACTIONstatement providedisdifferent thanthefirstACTIONoneachUnit1insertinthatitdoesnotapplytoanyUnit1(tagalong)loads.ThisisbecauseUnit2requiresonlythecommonloadstosupportitsoperation.

ThesecondACTIONproposedintheUnit1insertscoverstherestoration ofthenormalUnit1alignment withrespecttounitizedloads.SincenoUnit2loads C1il'ifmt1LIII""II'I DEC61984Page3SSESPLA-2370ER100450File841-8Mr.A.Schwencer arebeingtransferred duetothischange,suchanACTIONisnotrequiredintheUnit2specifications.

NOSIGNIFICANT HAZARDSCONSIDERATIONS:

I.Theproposedchangesdonotinvolveasignificant increaseintheprobability orconsequences ofanaccidentpreviously evaluated, forthefollowing reasons:Eachunithasfourindependent 125-voltDCpowersources.TheFSARanalysisshowsthataunitcanbesafelyshutdownwithanyone125-voltDCpowersourcedisabled(Section8.3).Basedonthereviseddesign,one125-voltDCsourcewouldfailduetoafaultinaUnit1tagalongloadifbothupstreamprotective devices(fuseanddistribution panelbreaker)failed.ThemorelikelyresultofafaultonaUnit1tagalongloadwouldbelossofanindividual circuit.Therefore, themostprobablefailureislessseverethanthelossofanentirepowersource,whichhasbeenpreviously evaluated.

Finally,theUnit2batteries havebeenanalyzedanddohavesufficient storedenergytooperateallnecessary loadsforthedesignbasisintervaloffourhours,afterlossofACpowerandassumingthelossofthebatterycharger.II.Theproposedchangesdonotcreatethepossibility ofanewordifferent kindofaccidentfromanyaccidentpreviously evaluated.

Asstatedabove,theprobablefailureasaresultofthereviseddesigniswithintheboundsofthepreviousFSARanalysis, andbatterycapacityissufficient tomeetdesigncommitments.

Therefore nonewordifferent possibility exist.III.Theproposedchangesdonotinvolveasignificant reduction inamarginofsafety.Basedontheexistence ofsufficient batterycapacity, theincreased reliability ofUnit1duetocontinuity ofp'ower,andthefactthattheworstcasefailureduetothenewdesignisconsistent withpreviousanalysis, onecanconcludethattheexistingmarginofsafetyhasnotbeenreduced.Basedupontheconsiderations presented above,thischangeappearstofallunderanexampleasstatedin48FR14870, Column3,paragraph (vi).PPSLdoesnotethatthischangepresentsadeviation fromourpreviousFSARcommitments toRegulatory Guide1.81,anduponapprovalofthischangewewilltaketheappropriate stepstorevisetheFSARaccordingly.

~>~~V'I DEC61984Page4SSESPLA-2370ER100450File841-8Mr.A.Schwencer IMPLEMENTATION SCHEDULE:

Asstatedatthebeginning ofthisproposal, themostimmediate problemwhichisbeingavoidedasaresultofthischangeistheshutdownofUnit2duringtheUnit1firstrefueling outage.Therefore, itisimperative thatPP&Lreceiveapprovaloftheproposedchangepriortoorveryearlyintotheoutagesothatbatteryloadprofiletestingcanproceedonscheduleandasaresultofthismodification, notforcetheshutdownofUnit2.Theappropriate feespursuantt'o10CFR170.22 havebeenenclosed.

Anyquestions onthismattershouldbedirectedtoMr.R.Sgarroat(215)770-7855.

Wearewillingtomeetwithyouatyourconvenience tofurtherdiscussthismatter.Verytrulyours,N.W.CurtisVicePresident-Engineering

&Construction-Nuclear Enclosures cc:M.J.Campagnone USNRCR.H.JacobsUSNRCT.M.Gerusky,DirectorBureauofRadiation Protection Pa.Dept.ofEnvironmental Resources P.0.Box2063Harrisburg, PA17120 4~PH~IH\P~'!IIIeHTHIgtt;*rerHT~p"'llPPI~I~~I'~~~HlP~r~PIedIP