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Addendum to Final Rept Independent Design Review- Susquehanna Steam Electric Station.
	ML18031A407
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Site:	Susquehanna
Issue date:	10/27/1982
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8TELEDYNEEMQIMEERIMQ SERVICESTR-5599-0 ADDENDUMTOFINALREPORTINDEPENDENT DESIGNREVIEWSUSQUEHANNA STEAMELECTRICSTATIONOCTOBER27,198282iiOi0072 82i027PDRADOCKOS0003871PPDR PENNSYLVANIA POWERANDLIGHTCOMPANYTWONORTHNINTHSTREETALLENTOWN, PENNSYLVANIA 18101TECHNICAL REPORTTR-5599-3 ADDENDUMTOFINALREPORTINDEPENDENT DESIGNREVIEWSUSQUEHANNA STEAMELECTRICSTATIONOCTOBER27,1982'PC'TELEDYNE ENGINEERING SERVICES130SECONDAVENUEWALTHAM,MASSACHUSETTS 02254617-8Rh3350 Technical ReportTR-5599-4 wTELEDYNEENGINEERINQ SERVtCESTABLEOFCONTENTS

1.0INTRODUCTION

2.0CLOSINGOFFINDINGS2.1FindingNumber12.2FindingNumber23.0ANCHORRECONCILIATION, PROGRAM3.1Definition of'Anchor 3.2ProgramDivision3.3ProgramDetails4.0PROGRAMMONITORING

5.0CONCLUSION

S 6.-0REFERENCES

~Pae6APPENDICES 1-TESLetterNumber5599-172-As-BuiltReconciliation ProgramReviewObjectives andProcedures Manual s>TELEGYNEENQINEERlNQ SERVICESTechnical ReportTR-5599-4

1.0INTRODUCTION

Thisreportissubmitted toservetwopurposes.

ThefirstistocloseoutthetwofindingsdefinedintheTESFinalReportNumberTR-5599-3 datedAugust22,1982(Reference 1).ThesecondistoactasanExecutive Sum-marytotheIndependent DesignReviewperformed byTESontheSusquehanna SteamElectricStation.2.0CLOSINGOFFINDINGSThe~following discussion presentsthedetailsbehindtheclosingofFindingsbyTES.2.1FindinNumber1ThisFindingwasclosedbyLetterNumber5599-17,datedOctober19,1982,whichisattachedinAppendix1.ThebasisofFindingNumber1wasthattheDesignSpecification categorization ofplantoperating conditions wasnotproper.InBechtelDesignSpecification 8856-M-175, Revision5,thetransient condition "LossofFeedwater Pumps,MainSteamIsolation ValvesClosed"isclassified asanEmergency Condition.

Basedontherequirements ofASME,BPVCSectionIII(Code)thisclassification precludes thiseventfromconsideration inthefatigueevaluation.

However,theCode.inParagraph NB-3113.3 requiresthataneventclassified asanEmergency Condition:

"shallnotcausemorethan25stresscycleshavinganSavaluegreaterthanthatfor10cyclesfromtheappli-cablefatiguedesigncurvesofFiguresI-9.0."

-s>-TELEDYNE ENGINEERING SERVICESTechnical ReportTR-5599-4 Thisevent,"LossofFWPumpsMSIVClosed"isspecified asoccurring tentimes.Foreachoccurrence, th'reestepchangesintemperature from546Fto40Fandonestepchangeintemperature from546Fto100Fisspecified.

Additionally recoveryfrom40Fto546Fatvarioustimesisalsospecified.

Basedonthespecified conditions, morethan25stresscycleshavinganSvaluegreaterthanthatfor10cyclesfromtheapplicable fatiguecurveswilloccur.Thiseventwillhaveasignificant impactonthefatiguelifeofcomponents andmustbeconsidered inthefatigueevaluation.

Thiscanonlybeaccomplished byclassifying theeventasanUpsetCondition.

Theinformation submitted byBechtelinReference 3addressed theimpactofthe"LossofFeedwater Pumps,MSIVClosed"transient ontheFatigueUsageFactorfortheMainFeedwater System.Further,astudywasdonethatdetermined thefatigueeffectonallotherClass1systemswasnegligible.

Asummaryofthatinformation follows:~SstemFeedwater CoreSprayRPVDrainStandbyLiquidControlRCICHPCIHeadVentHeadSprayMSIVDrainFactor~Stud0.94940.89850.35760.43830.61510.82950.60270.79570.03930.89930.89750.35760.43320.61460.82900.60210.79560.0384~U~5<<RItisimportant tounderstand thattheTESpositiononthisFind-inghasalwaysbeenthatasafetyconcerndidnotexist.Infact,TESpointedoutattwoNRCstaffmeetingsthatourexperience inanalyzing w-TELEDYNE ENGINEERING SERVtCESTechnical ReportTR-5599-4 Class1BWRsystemsindicated thattherequirements oftheASME,BPVCSectionIIIwouldbemetconsidering thiseventasanUpsetOperating Condition.

TESneededdocumentation fromBechtelverifying thisposition.

Thathasbeensubmitted inReference 3.FindingNumber1hasbeenaddressed tothesatisfaction ofTESandistherefore revisedtoanObservation.

2.2FindinNumber2ThisFindingisrelatedtothereconciliation processofas-builtsupportsandresultsfromthefactthatfurthercalculations wererequiredbyBechteltoresolveas-builtgeometries fortheMainFeedwater System.Thefollowing isasummaryoftheFindingasdetailedinReference l.FindingNumber2(Phase1FindingNumbers7,9and10,andObser-vationNumbers3,4,5,6,7and9)Asignificant numberofcommentshavebeengenerated onthesup-portdesignprocess.Mostofthesecommentsarerelatedtoreconciliation ofas-builtgeometrybythesupportdesigner.

Theconcernisbasically associated withacceptability oftheas-builtsupport.Twomajoritems(FindingNos.7and10)havebeenresponded tobyBechtelinthisPhase2portionofthereviewbuttheyonlytendtosupportthattheprocessdidnotwork.TheresponsetoPhase1FindingNo.7indicates thatthepipesupportreviewerandcheckerdetermine whetherarelocated supportwasasignificant enoughchangetowarrantaCivildepartment review.InthecaseofthespecificsupportofconcernnoCivilreviewisapparent.

How-ever,thereisanewplaterequiredintheas-builtdesignwhichisthe I~A~pgLEENQ!NEERlNQ SERVCESTechnical ReportTR-5599-4 responsibility oftheCivildepartment.

Thesupportdesigngroupcalcula-tionsindicatethattheplatewillbehandledbytheCivilgroupandtheCivilcalculations donotaddresstheplatesincetheydonotknowthesupportislocatedonitwithouthavingtheas-builtgeometryforwarded tothem."InthefinalBechtelsubmittal theplatehasbeenanalyzedbytheCivildepartment asaresultoftheTESfindings.

TheresponsetoPhase1FindingNo.10indicates thattheweldattheshieldwallisacceptable afterreducingtheconservatism intheorig-inalanalysisandperforming adetailedcomputersolutionofthesupport.Itisapparentthatthisweldwasnotaceptable byinspection asoriginally statedbyBechtel.Responses toFindingNumber9andtheObservations listedunderthisFindingwerereviewedandinsomecasesindicate, theObservation couldhavebeenclosedifsufficient detailwasprovidedintheBechtelrecon-ciliation process.DuringtheAugust10,1982meetingatTES,Bechtelindicated thatgroupmeetingsandtrainingsessionswereheldtoexplainprocedures usedinthereconciliation process.Further,thereviewercheckseachitemanddetermines acceptability andevencrosseseachitemoffthathejudgesisacceptable onacheckprint.Noneofthisinfor-mationisretainedbyBechtelnoristhereanyrecordmaintained ofmeetingsortrainingsessionsforthispurpose.IInresponsetothisFinding,PPELundertook areviewofthereconciliation processforanadditional 20supportsonsystemsotherthanthefeedwater system.Thatreviewindicated thatoneanchorwouldrequireextensive reanalysis.

Essentially, theas-builtanchorhadapproximately one-fourth oftheas-designed weldlength.Asaresultofthis,PPKLelectedtogotoasampleof400supports.

Thebreakdown ofthatsampleisasfollows:

AEENQlNEERINQ SERVICESTechnical ReportTR-5599-4 ComositionofSamleTe~P1i~5SnubbersSpringsRigidSupportsAnchors25K15K54K6X100K11%3X75K11%100KThesampleconcentrated moreheavilyonrigidsupportsandanchorsbecausetheIDRFindingandtheoriginalPPKLsampleihdicated thatthesewerethemostcriticaltypesupportswithrespecttoreconciliation.

Adetailedprocedure forthereviewofthe400supportswasdeveloped byPPKLandreviewedbyTES.Acopyofthatprocedure isattachedinAppendix2.ATESobserverwaspresentattheBechtelofficesinSanFrancisco duringthemajorpartofthisreviewrelatedtoCategori-zation.Ourobservation ofthatprocessincludedspot-checking ofsupportstodetermine ifTESagreedwiththecategorization.

TESconcluded thattheprocessasdefinedbyPPKLandreviewedbyTESwasbeingcarriedoutsuc-cessfully andthatthepersonnel involvedinCategorization wereallowedtoreachdecisions independently.

Basedonthis,TESdetermined thatareviewofallCategoryIIIsupportswouldbesufficient toreachourconclusion.

Ourreviewof80supportsdesignated asCategoryIIIresultsinthefollow-ing:1.Theoriginalreconciliation processindicates weaknesses intheareaofacceptance ofas-builtdesigns.Thisispri-marilyyrelatedtothosesupportsthatwerereconciled basedonengineer',ng judgment.

Thisisbasedonthefactthat14supportsrequiredextensive reanalysis todetermine adequacyand40supportsrequiredsomesimplerecalculation.

Extensive analysisincludesdetailcomputeranalysisofthe ATELEDYNEENQINEERIMQ SERVlCESTechnical ReportTR-5599-4 supportand/orreanalysis ofthepipingsystemtoreduceloadingconservatisms.

2.Thecategorization of89itemsinCategoryIIIwasverycon-servative.

ItisTES'pinion thatapproximately one-halfofthesesupportsshouldhavebeenCategoryII.3.Allsupportsotherthananchorshavebeendemonstrated tobeadequatebythePPELreviewandtheBechtelresponses, including reanalysis.

TEShassufficient evidencetoremovethesefromfurtherconsideration.

4.Areconciliation problemrelatedtoweldcapacitystillexistsforanchors.Aprogramacceptable toTEShasbeenpresented inSection3.0.Acceptance ofthisprogrambyPP8LwouldsatisfyFindingNumber2oftheIDR;3.0ANCHORRECONCILIATION PROGRAMInorderforTEStoremoveFindingNumber2,thefollowing pro-grammustbeacceptedbyPPSL.3.1Definition ofAnchorAnanchorisdefinedasanysupportthatprovidesrotational aswellastranslational restraint tothepipingsystem.Onedirection ofrotational restraint issufficient forasupporttobecategorized asananchor.Anchorswhicharepartofcontainment (fluedheads)aridanchorsatequipment (pumps,vessels,etc.)arespecifically excludedfromthispro-gram.Essentially, thisprogramislimitedtointermediate anchorswhichusestructural steeltoproviderestraint.

Technical ReportTR-5599-4

><TELEDYNEENQINEERINQ SERVICES3.2ProramDivisionTheprogramshouldbedividedintotwophases,asfollows:1.Phase1-anchorsinsidecontainment.

2.Phase2-anchorsoutsidecontainment.

ThereasonforthisdivisionisthatTESfeelstheplantshouldbeallowedtooperateoncetheanchorsinsidecontainment havebeenreconciled.

Thisisbecausetheearthquake event(OBEorSSE)isasignificant loadforallanchorsand,fortheshorttimeneededtoreconcile anchorsoutsidecon-tainment, theeventprobability shouldbeverylow.3.3~33Allanchorsshal)besubjected tothecategorization processdefinedinAppendix2.ThoseanchorswhichareplacedinCategoryIand/orIIwillbeacceptable bydefinition.

ForthoseanchorsplacedinCat-egoryIIIonlyanalysiscomparable totheas-designed analysisisallowable forreconciliation.

Ifreconciliation cannotbereachedinthismannertheanchorwillbemodifiedtoreflectas-designed.

Whereinterference oraccessdoesnotpermitthisapproach, modifications totheanchormaybemadewhichdonotreflectas-designed butdoprovidethesamedesignmargin.Itisnotedthatanalysistechniques beyondthoseusedintheoriginalanchordesignarenottobeusedtoprovidethedesignmargin.4.0PROGRAMMONITORING TES'eview oftheimplementation ofthePP8Lprogramforrecon-ciliationn ofthe400supportsamplewasquiteextensive.

Basedonthis

-<>-TELEDYNE ENQINEERINQ SERVICESTechnical ReportTR-5599-4 review,ourconfidence inthePP&Lpersonnel involvedandPP&L'scommitment tothisprogram,wefeelthereisnofurtherneedforTESparticipation.

5.0CONCLUSION

S TheIndependent DesignReviewperformed ontheMainFeedwater systemattheSusquehanna SteamElectricStationwasquiteextensive inscope.ThisreviewprovidedTESwithadetailedunderstanding ofthefollowing:

5.1FSARcommitments, 5.2gualityAssurance procedures, processandimplementation, 5.3Designprocedures, processandimplementation, 5.4As-builtconfiguration, 5.5Reconciliation ofas-builtgeometries versusas-designed, and5.6Implementation ofFSARcommitments.

Based'ontheresultsofourIndependent DesignReview,itisTES'pinion that,uponcompletion oftheprogramoutlinedinSection3.0ofthisreport,thecommitments oftheFSARhavebeencompliedwithfortheSusquehanna SteamElectricStation.

6.0REFERENCES

6.1TESFinalReportTR-5599-3, "Independent DesignReview-Susquehanna SteamElectricStation",

datedAugust23,1982.6.2PP&LLetterNumberER100450, PLA-1328, datedOctober4,1982,fromN.W.Curtis(PP&L)toA.Schwencer (USNRC).6.3BechtelLetterNumber0176565,datedSeptember 24,1982,fromE.B.Poser(Bechtel) toR.Enos(TES).

Technical ReportTR-5599-4 ATELEDYNEENQINEERtNQ SERVlCES(APPENDIX1TESLETTERNlNBER5599-17 ATElEDYNEENGINEERlNG SERVlCES130SECONDAVENUEWAOHAM,MASSACHUSETfS 02254(617)6903350IWX(710)324.7580October19,19825599-17Mr.RobertJ.ShovlinAssistant ProjectDirector-Susquehanna Pennsylvania PowerandLightCompanyTwoNorthNinthStreetAllentown,Pennsylvania18101~Sub'ect:

TESIndependent DesignReview-Susquehanna SteamElectricGenerating Station

References:

(1)PPSLLetterER100450datedOctober4,1982(2)BechtelresponsetoPhase2,FindingNo.1(Identifi-cationNo.0176565)datedSeptember 24,1982

DearMr.Shovlin:

Attachedaresixcopiesofthisletter.Wehavealsoforwarded copiestothefollowing partiesinaccordance withyourinstructions.

Mr.A.Schwencer U.'S.NuclearRegulatory Commission 7920NorfolkAvenueBethesda, Maryland20014Mr.RobertPerch(ToBeOpenedbyAddressee Only)U.S.NuclearRegulatory Commission 7920NorfolkAvenueBethesda, Maryland20014Mr.J.B.Violette(4copies)BechtelPowerCorporation P.0.Box3965,"50BealeStreetSanFrancisco, California 94119Thisletterissubmitted asapreliminary reactiontoReferences (1)and(2)responses toPhase2,FindingNo.1,oftheTESFinalReport.Thisitemwillbeaddressed ingreaterdetailinanAddendumtotheTESFinalReport.Itisanticipated thattheAddendumwillbesubmitted uponcom-pletionofareviewbyTESoftheSupportReconciliation ReportbeingpreparedbyPPSLinresponsetoPhase2,FindingNo.2.ThebasisofFindingNo.1isthattheDesignSpeci'fication categorization ofplantoperating conditions isnotproper.Thisisspecifically relatedto"LossofFeedwater Pumps,MSIVClosed"beingclassified asanFNGINFFRS ANOfi';""TALLURGISTS Mr.Shovlin,PPKL5599-17October19,1982Page2PsTELEDYNEENGINEERINQ SERVICESEmergency Condition.

References (1)and(2)indicatethattheinclusion ofthistransient intheUpsetCondition categorydoesnotviolateCodefatiguecriteria.Further,astudyofothersystemsindicates thatthistransient islesssevereandwouldhavenegligible effectonfatigueusagefactorsforthosesystems.TEShasstatedattwomeetingswiththeNRCstaffthatourexperience inanalyzing BMRpipingsystemsindicates thattheresultsobtainedbyBechtelcouldbeexpectedandnosafetyconcernsexisted.Basedonthisknowledge, TESrequested thatsufficient documentation bepresented toindicatethatBechtelreachesthesameconclusion whenthistransient isconsidered asanUpsetCondition.

Thisdocumentation waspresented inReference (2).Itisapparentthatthedefinition ofFindingasusedbyTESintheIDRofSusquehanna isbeingmisunderstood.

AFindingdoesnotnecessarily meanthatasafetyconcernexists.TESfeelsthatanyconcernsresulting fromPhase2,FindingNo.1,withrespect.tosafetyshouldbeeliminated.

Basedontheabove,Phase2,FindingNo.1,shouldbechangedtoanObservation thathasbeensufficiently addressed byPPKL.Ifyouhaveanyquestions concerning thispleasedonothesitatetocontactme.Verytrulyyours,TELEDYNEENGINEERING SERVICESdgt.Lados,DonaldF.LandersSeniorVice-President DFL/lhcc:R.A.Enos(TES)D.Messinger (TES)TESDocumentControl dIl Technical ReportTR-5599-4

<>TELEDYNEENQtNEERIMQ SERVrCESAPPENDIX2AS-BUILTRECONCILIATION PROGRAMREVIEWOBJECTIVES ANDPROCEDURES MANUAL Revision010/9/82Revision1IO/9/82I(Q<~Revision210/12/82AR-BUILTRECONCILIATION PROGRAMREVIEWOBJECTIVES ANDPROCEDURES MANUALSUSQUEHANNA STEAMELECT1GCSTATIONPENNSYLVANIA PCNER&LIGHTCOMPANYR.~NP23/1-1N..Rhoades-P.P.EL.

Page2IHIROIX3CTION Ithasbeenconcluded byPP&Lthatadditional reviewoftheAs-BuiltReconciliation Programisnecessary.

'Ihepurposeofthisreviewistoprovideaveryhighconfidence leveltoPP&LandtheNRCthatthereexistnounsafepipingsupportsintheSusquehanna SteamElectricStation.Accordingly, PP&Lhasselectedasamplesizeoffivehundred(500)seismiccategoryonesupportstobereviewed.

Thissamplesizeprovidesuswiththehighdegreeofconfidence werequire.However,afterwehavereviewedseveralhundredsupports, thissamplesizemaybeadjustedupwardsordownwards depending ontheresultsofthesurveyatthattime.Selection ofthesupportstobereviewedwillbemadebyPP&Lrepresentatives.

Itisintendedthatthesampleselectedberandomwithrespecttosystemsbutskewedinfavorofanchors,rigidandoperationally activesnubberswithlessconsideration towardsdeadweighttypesupports.

Acanpletelistofthosesupportsselectedwillbedocunented inthefinalreport.WP23/1-2 r

Page3DEFINITIONS Thefollowing arethedefinitions ofthecategories ofdifferences betweentheas-builtandengineering drawings.

CAHKORYI:Arethosedifferences whichareconsidered insignifi-cant,suchasslightvariation indimensions.

CATEGORYII:Arethosedifferences whichmaybeofconcernbutuponfurtherinvestigation areconsidered acceptable.

Theinvestigation, however,maybebyengineering judgement orbysimplyreferring totheasMesigned calculation andnotingwhattherequirements oractualstressesare.CATEGORYIII:Arethosedifferences whichareofconcernandrequirefurtherevaluation.

Theevaluation wouldrequireanadditional analysisor,amoredetailedanalysisoftheoriginalcalculation.

REJECT:RejectisdefinedbyPP&Lasanysupportthat,inthejudgement ofPP&L,requiresafieldhardwaremodification.

WP23/1-3 Page4ORGANIZATION Thisprogramisorganized intothreeprimarytaskgroupsplusadocunentation retrieval group.Taskgrouponewillperformthefunctionofcanparing andclearlyidentifying alldifferences betweenthefinal"as-built" andtheengineering analyzedsupportdrawing.Grouptwowillperformthejudgements anddetermine towhichcategoryeachitem,highlighted byGroupone,istobeputanddocumentthatcategory.

GroupthreewilltakethoseCategoryIIIwhichrequireresolution andperformthenecessary calculations oradditional researchworktoverifyacceptability ofthesupport.Iffieldwalkdownforreviewofspecificsupportisrequireditwillbemadeanddocumented bythePP&LResidentEngineering.

DOCUMENTATION RETRIEVAL STEPS-1.Check'Pipe SupportlistagainstDOCRETtonotethelatestEngineering revision.

(DOCRETisthelogofengineering revi-sionsissuedandisgenerated franmicrofilm cardsandwasinexistence atthetimeofas-builtreconciliation.)

W'23/l-4 Page52.CbpyofEngineering revisiona.Retrievecopyb.Make1copyc.'Xbbefiledinbinderlater3.Cbpyofthelatestas-builtfromtheABR(As-Built Reconciliation) bindera.Checkrevisioninbinderreconciliation sheetb.Iacateas-builtP.S.detailintheABR.Checktoensurethatthestickerissigned-off byEngineering.

c.PutmarkerintheABRbinderd.Sign-outoutcarde.Make1copyf.Filebackwheremarkerwasg.Sign-outABRout-card.

CanrisonofEnineeriandAs-BuiltPiSurtDetails(Yellow-out Process):

1.CbtaincopyofEngineering andas-builtP.S.revision2.Yellow-out allitemsthatareidentical onbothEngineering andas-builtpipesupportdetail.3.Itemsnotidentical totheEngineering revisionshouldbecircledinred.m23/1-5 Page64.Identifyitensthatarenotidentified oneitherofthedrawingsbyat'ircleingreenwithanasteriskmark.Itistobeemphasized thatnogudgenents aretobemadebyGrouponepersonnel andthatalldifferences, nomatterhowtrivialtheymayappear,aretobemarkedinredorgreen.Thefollmring exampleisanillustration ofthisrequirment:

Enqineerinq Drawi"AsBuilt"ThisitemistobemarkedinredonAs-BuiltdrawingBillofMaterials Enqineering 4w>3x6'-2""As-Built" 4l4!3x~6'l"Wisitenistobemarkedinred5.Filloutthecoversheetcarpletely 6.Packagecoversheet,Engineering revisionandyellowed-out as-builtP.S.detail.7.Allpackagesreturnedtogrouponetaskcoordinator forPALreview.RP23/1-6 Page7GROUP2ReviewandDissitionofDifferences BetweenEineeriandAs-Built~D'tBWiSl.EnsurethatGroupOneCoverSheethasbeenproperlysignedoffpriortoperforming anyreviews.2.Recordeachdifference ontheprescribed sheet(attached).

3.Categorize eachdifference asCategoryI,II,IIIas-described inDefinitions Section.4.Besolutions:

CategoryIdifferences arethosethatareinsignificant suchasslightvariation indimensions andthus,areacceptable bydefinition.CategoryIIdifferences arethosethatareacceptable byengineering judgement orreference tooriginalcalculations.

Forexample,thedesigncalledfora6"diameterpipehavingawallthickness of3/8".Theas-builtshowsa6"x6"x1/4"thicksquarestructural tubeisusedinstead.Thismaybeacceptable byengineering judgement bycanparing theareaandsectionmodulesoftheminrelationtotheimposedload.Anotherexampleisthedesignhascalledfora3/8"filletweldallaroundamenber.Theas-builtshows5/16"filletweldisusedinstead.Byreferring totheoriginalcalculation, itisnotedthata1/4"filletweldisrequiredandthusisacceptable.

WP23/1-7 Page8(Mte:Theoriginalcalculations areQAdocunents and,assuch,areconsidered validandacceptable designbasiscalculations.

Therefore, therewouldbenoneedtore-review theoriginalcalculations andwouldbebeyondthescopeofthistask).CategoryIIIdifferences arethosethatrequireadditional calculations toresolvethedifference betweentheas-designed andas-built.

YoushouldsearchtheAs-BuiltReconciliation (ABR)booktoseeifthereexistcalculations thataddresseachCategoryIIIdifference.

WhentherearenoABRcalculations foranitemorthecalculations arenotsatisfactory, youshouldidentifythatadditional calculations arerequiredpriortoacceptance orsignoff.Pleaseprintyournameandyourteamleader'snameonthefirstsheetforidentification pursespriortosubmitting themtoyour.teamleader.Whenadditional calculations arerequired, thenecessary calculations willbeperformed byGroupIIIandprovided.

toyou.Ifadditional cal-culations areneededtoresolvethedifference(s),

nomatterhowsimpleacalculation, youarerequested nottomakethemyourself.

Thisisbecauseoftwo(2)reasons.First,thethecalculations needtobeverifiedinaccordance withestablished procedures andbedocunented.

Second,theGroupIIIfunctionistomakethesecalculations andtheyareavailable todoso.AfteryouNP23/1-8 areprovidedwiththecalculations thepackagewillbeconsidered canpleteifyouconcurwiththecalculations andallCategoryIIIdifferences havebeenaddressed.

Ifnot,aresolution forthemwillberequired.

Ifthereisaninpass,PP&Lshalldetermine thefinalresolution for.them.Ifrejectsareidentified (seedefinition) becausehardwarechangesarerequiredtheywouldbeidentified andsignedoff.Needlesstosay,iftherearenoCategoryIIIdifferences, the"As-Built Reconciliation Judgement Verification" formshallbesignedoffbasedonacceptance ofCategoryIandIIdifferences, ifany.5.ItemsthatneedFieldverification orclarification duetodrawing.ambiguity, clarityshouldbeidentified andbroughtto'I@amleader'sattention forresolution.

6.ForwardpackagetoPP&Lrepresentative forreviewandconcurrence.

GROUP3Perfonnance of.Additional Calculations toJustifAdeacoftheDifferences DesinatedasCatoIIIGrouII1.Generatecalculations perPEWasnecessary tovalidatethedifferences andtheas-builtcondition totheextentfeasible.

Allpackagesforwarded toGroup3requireindividualized disposition WP23/1-9 Page10toassuresupportadequacy.

Onceyoureceiveapackageidentifywhatmustbedone,notifyPP&Lofyourintendedaction,andproceed.Ifacalculation needstoberun,proceedimnediately and,onceappropriate calculations areccmplete, attachthemtotheccmpleted package,signthecoversheetandfonmrdthemtoPP&L.Iffieldcheckingofanitemisrequired, notifyPP&Landtheywillmakearrangements forPP&LResidentEngineering grouptomakenecessary checks.Ifanysupportcannotberesolvedbyadditional calculations, notifyPP&Lirrrnediately.

FINALDOCUMENTATICN:

l.Asampleselection oftheFinalDocunentation PackagewillbemadebyPP&Ltoassurethefollowing:

a.As-BuiltReconciliation Judgement Verification sheetcanletely filledin.b.Copiesofyellow-out coversheetsfilledin.c.CopiesofEngineering revisionandas-builtP.S.detail(yellow-out copy)d.Calculations asapplicable, andwhengenerated byGroup3~foreachpipesupport.WP23/1-10 PagellLISTOFATTACHMENTS:

1.SamplesignoffsheetforGroup12.SampleAs-BuiltReconciliation Judgement Verification SignoffsheetforGroup2.WP23/1-l1 f'IlASWUILTRECONCILIATION PROGRAMREVIEWHGRRNORCOMPARISON OFENGINEERING ANDASBUILTPIPESUPPORTDETAILYELLORtOUTPROCESS)PERFORMED BYlPRINTNAMESIGNATUREDATEORGANIZATION REVIEWPERFORIEO'YES SIGNATURE PP.<REVIEWEPBYl(IFYES)PRINTNAMESIGNATUREDATEORGANIZATION ASBUILTRECONCILIATION JUDGMENTVERIFICATION SUPPORTTYPESUPPORTINGoNOs!SOD46sNO>t':ENGGDING)REVeASBUILTREVeSYSTEMSHEET1OFPERFORMED BYlSIGNPRINTREVIEWEDBY,'IGNPRINTFCICATEGORYIDIFFERENCES RESOLUTION CATEGORYIDIFFERENCES AREDEPENDACCEPTABLE BYDEFINITION I~I~~

ASBUILTRECONCILIATION JUDGMENTVERIFICATION SUPPORTDWGINOeSHEETOFiCATEGORYDIFFERENCES RESOLUTION 4llUMIAK-tCATRQQRY3K,RRSPQMSR~ABERCANC.RRQ.QYl6.

MY.ASSU)LTQSV.ABRCALO.PsesrGMmseuiaan".

ABSPQNSR:

RRSPQNSKE'f.QuaAtwmnvseey ASBUILTRECONCILIATION JVDGNENTVERIFICATION SUPPORTIsaNOISHEETOFDIFFERENCES CATEGORYIIRESOLUTION 4CATEGORYI,II I.Issuel.EffectsofLocalEncroachments onPoolSwellLoads2.SafetReliefValveDischareLineSleevesII.Assessment/Res onseTheNRCdispositioned theseconcernsasN/AforSSES.III.FutureActionReuiredNone8211060230 I.Issue3.ECCSReliefValveDischareLinesBelowtheSuressionPoolLevel3.1Thedesignofthestudyplantdidnotconsiderventclearing, condensation oscillation andchuggingloadswhichmightbeproducedbytheactuation ofthesereliefvalves.IIII.Assessment/Res onseInprefacetotheresponsetotheaboveconcern,itshouldbenotedthatthesteamcondensing mode(SCM)isan'operationally non-safety-related subsystem oftheRHRsystem.Itprovidesanoptionalmethodofremovingreactordecayheataftershutdownbycondensing reactorsteamintheRHRheatexchanger.

Areliefvalveisprovidedtoprovideoverpressure protection totheheatexchanger and,associated pipingandcomponents.

TheRHRSRVdischarges intothesuppression poolthrougha10"diameteropen-ended pipeatasubmergence of4'elowlownormalwaterlevel.Duringpoweroperation theRHRheatexchanger isisolatedfromthesteamsupplybytwoindependent andredundant safety-grade isolation valves.Therefore, liftingoftheRHRSRVduetooverpressure isonlyassumedtooccurduringSCMoperation.

Thesteamflowto,theRHRheatexchangers (Hxs)iscontrolled bytwoin-series pressurecontrolvalves(PCVs),whichmaintainanoperating pressureof200psigintheHxs.RHRSRVactuation occursforthefollowing twoscenarios:

oBothPCVsfailopen.oFailedopenRHRSRV.Forthefirstcase,bothPCVsarecontrolled bythesamecontroller; thus,asinglefailureinthecontroller leadstopossiblybothPCVsactuating tothefullopenposition.

Following thefailure,thedownstream pipingpressurizes tothereliefvalvesetpressure andopenstorelievepressure.

SincetheRHRSRVsteamflowexceedstheflowcapacityofthetwocontrollers, thepressuredecreases andtheRHRSRVquicklyreseats.OncetheRHRSRVrecloses, the6"VBsmountedontheRHRSRVDLopentoallowairintotheRHRSRVDL.Thepressureagainincreases untiltheRHRSRVliftstorelievepressurecausingamixtureofairandsteamtoflowintothepool.This"cycling" oftheSRVcontinues untiltheoperatorisolatestheSCMmode.Duringthistime,thesteamflowingthroughthePCVssimultaneously condenses intheRHRHxandflowsthroughtheRHRSRV.Furthermore, theRHRSRVcyclesrapidly,sothatthesteamflowneverreachessteady-state conditions.

Fortheabovereasons,theaveragesteamfluxintheRHRSRVDLismuchlowerthanthetheoretical maximumsteamfluxbasedontheratedflowthroughtheRHRSRVundersteady-state conditions.

PivrIllII Thesecondscenariopostulates afailureintheRHRSRVitself(i.e.,brokenspring)causingtheRHRSRVtofailwideopen.Undertheseconditions, thePCVwillmodulateopentoattempttomaintainadownstream pressureof200psig.However,thecontroller tothePCVselectronically limitsthePCVsto60%fullopen;thus,themaximumflowthroughthePCVswillbelessthantheratedflowofthePCVs.Again,understeady-state conditions, theflowthroughthePCVsmatchestheflowtotheHxandRHRSRV.However,noSRVcyclingoccurs,sincetheRHRSRVfailedopen.Again,theRHRSRVsteamfluxismuchlowerthanthesteamfluxbasedontheratedflowthroughtheRHRSRVundersteady-state conditions, sincethePCVslimittheflowandsteamcondenses simultaneously intheRHRHx.Forbothfailuremodes,theRHRSRVdischarges steamtothesuppression pooluntiltheoperatorisolatesthesystem.WeassumetheoperatorwilldetectandisolatetheSCMsystem10minutesafterthefailureoccurswhichleadstoflowthroughtheRHRSRV.Operatoractionbasedon10-minute delayisjustified sinceinstrumentation isavailable todiagnosethesituation andtakeappropriate corrective action.OnceRHRSRVsteamflowbegins,theSuppression PoolTemperature Monitoring System(SPOTMOS) willalarmonhighpooltemperature andprovideearlywarningofsteamdischarging tothepool.Inaddition, variousindications ofSCMoperation, including RHRHxlevelandpressure, areavailable toindicatetotheoperatorthattheRHRSRVlifted.Ourpreliminary assessment oftheeffectsoftheloadscausedbyactuation oftheRHR,,SRVfollows.Fromaglobalperspective, webelievetheexistingLOCAsteamcondensation andMSRVbuildingresponses boundtheresponses duetoanactuation oftheRHRSRV.Thatis,thebuildingmotioncausedbytheRHRSRVactuation wouldbemuchlessthaneither87ventpipeschugging, ortheresponsetothe16valveMSRVloadcase(reference SSESDAR).Therefore, ourevaluation oftheRHRSRVloadswillbeconfinedtothemosthighlystressed(leastdesignmarginforcurrentdesignbasis)submerged structures andlinerplatead]acent; totheRHRSRVdischarge.

Ourevaluation consistsofqualitatively comparing theoriginaldesignbasisandstressmarginsforthesubmerged structures andlinerplatewiththeexpectedloadsduetoRHRSRVactuation whenconsidering theappropriate loadcombinations.

Thehydrodynamic loadsduetoRHRSRVdischarge havenotbeenspecifically calculated, sincetheyareconsidered tobeboundedbytheexistingdesignbasis.However,weintendtoquantifytheloadsandprovidetheresultsofourassessment byMarch31,1983.Amoredetailedtaskdescription isgiveninSectionIIIofthisresponse.

InordertocomparetheexpectedRHRSRVloadswiththecurrentdesignbasis,wemechanistically determined theappropriate loadcombinations fortheRHRSRVloads.Webelievetheloadcombination tobeasfollows:

I'/V'V')V)II1(I' tRHRSRV+SSE+MSRV(lowsetpressure)',

i1Weeliminated theLOCAloadsbasedonthefollowing.

IfweassumeaLOCAoccursduringSCMoperation, coincident withafailureintheSCMsubsystem thatleadstoRHRSRVactuation, the.RHRSRVdischarge loadswillbeterminated priortothetimewhenthemostsevere'oadings duetoaLOCAoccur.ThesteamsupplytotheSCMsubsystem automatically isolatesviaaLOCAsignaltotwo,inseries,independent andredundant safetygrade,airactuatedvalves.ThesevalvesfailclosewhentheLOCAsignalventsofftheairtothevalveactuator.

Duringstartuptesting,theclosuretimesofthevalvesweremeasuredandindicated aclosuretimeoflessthan15sec.BasedonourreviewofourGKMII-Mdatabase(seeSection9.0oftheSSESDAR),thehighamplitude chuggingandlateraltiploadsatthedowncomer exitoccurmorethan15secafterthebreak.(Aswillbeshownlater,forthesubmerged structures, thelateraltiploadandchuggingsubmerged structure dragloadgeneratethehigheststresses.)

Atthistime,theSCMisolation valveswillhaveterminated thesteamflowtotheRHRSRV.Inaddition, post-LOCA SCMoperation willnormallynotoccur,unlessallothersafety-grade ECCSsystemsarenotavailable forremovingheatfromthereactor.Undertheseconditions, multiplefailureswillhaveoccurredintheECCSsystems,andassuch,thiseventgoesbeyondtheSSESdesignbasis.Thus,theRHRSRVloadswillnotbecombinedwithpost-LOCA hydrodynamic loads.Forthesamereasoning, theSRVADScaseneednotbecombinedwiththeRHRSRVload,sincetheSCMisolation valveswillcloseduringthetwo-minute delaycausedbytheADStimerpriortotheinitiation ofADS.TheMSRVloadresultsfromtheSCM'sinability toremoveallthedecayheatfromthereactorimmediately aftershutdown.

IftheSCMoperatesimmediately aftershutdown, thelowsetpointMSRVswillcycletoremovetheexcessdecayheatuntilsometimeaftershutdownwhentheSCMaloneissufficient toremoveallthereactordecayheat.Weassumeactuation oftheRHRSRVoccursduringthistimeperiod.ForSSES,thetwolowestsetpointMSRVs(1078psigsetpressure) discharge throughquenchers E5Blocatedapproximately 67'nd56.5',respectively, fromthepreviously described submerged structures adjacenttotheRHRSRVdischarge.

Thus,fromthisdistance, weexpectthatthesubmerged structure loadonthedowncomer and.bracingnearesttheRHRSRVdischarge tobenegligible.

Sincethesesubmerged structures experience negligible loadingfromMSRVinertialloading(seeTables3.1and3.2),weexpectnegligible loadingonthecriticaldowncomer anddowncomer bracingduetocyclingofthelowsetpointMSRVs.Inaddition, thesuctionloadonthelinerplateneartheRHRSRVdischarge duetothecyclingofthelowsetpointMSRVwillbemuchless4 r'1I thanthedesignbasissuctionload.Thequenchers E8Barelocatedatazimuthangles45'nd300',respectively, comparedtoanazimuthangleof180'orthelinerplateadjacenttotheRHRSRVdischarge.

BasedontheonevalveMSRVloaddocumented inSubsection 4.1.3.2.1 oftheDAR,thepeakunderpressure decreases asyoumoveazimuthally awayfromthequenchers.

Basedontheazimuthpressuredistribution fortheonevalvecase(seeDARFigure4-26),theunderpressures causedbyafiringofeitherquenchers EorB(angles45'nd300')decreaseto0.2ofthemaximumunderpressure atthequencherlocations atthe180'zimuth anglelocationfortheRHRSRVdischarge.

Thus,thesuctionpressureduetoquenchers EandBfiringresultinlowerloadsatthelinerplateadjacenttotheRHRSRVdischarge.

Basedontheabove,theloadsduetotheactuation ofthelowsetpointMSRVsresultinnegligible increaseinthesubmerged structure loadandlinerplatesuctionpressure, whencombinedwiththeRHRSRV+SSEloads.WecombinetheSSEloadsbasedonpreviousdesigncriteria.

Theonlysubmerged structures closetotheRHRSRVdischarge aretheneighboring downcomer andassociated bracingandthelinerplate.Ourcurrentdesignmarginsforthesesubmerged structures tobecombinedwiththeRHRSRVloadsareasfollows:Downcomer Table3.1providesthestresscomponents in%ofthetotalstressforthevariousloads,andthestressmarginforthecombination ofSSE+SRV(ADS)+LOCA.Asindicated, thestressmarginis53%,withSSEandLOCAlateraltiploadcontributing themoststresses.

TheSSEconsistsmostlyofthesubmerged structure loadduetoseismicslosh(seeSubsection 4.2.4.7oftheDAR).Theinertialloadsforallthreedynamicloadsareminimal,sincedisconnecting thedowncomer bracingfromthecontainment andpedestalwal'1eliminated theinertialloadingfromthesesources.Table3.1indicates thatbyremovingtheLOCAloadthestressmarginincreases to71%.IfwefurtherremovetheSRV(ADS)stresses, andassumeanegligible submerged structure loadonthisdowncomer duetothelowsetpointMSRVcycling,thenthestressmarginincreases to82%.

t TABLE3.1DOWNCOMER STRESSESANDSTRESSMARGINFORWORST-CASE DOWNCOMER ADJACENTTO,RHRSRVDISCHARGE Downcomer BendingStress=21ksiAllowable Stress=45ksiStressMargin=1-21/45=53%SeismicContribution SRV(Building Inertia)SRV(Submerged Structure)

LOCA(Building Inertia)LOCA(Submerged Structure)

LOCA(TipLoad)38%0%(Negligible) 24%3%9%26%100%

IIl TABLE3.2DOWNCOMER BRACINGSTRESSESANDSTRESSMARGINFORWORST-'CASE BRACINGADJACENTTORHRSRVDISCHARGE BracingMemberCombinedStress=1.6ksiAllowable Stress=20ksiStressMargin=1-1.6/45=92%SeismicContribution SRV(Building Inertia)SRV(Submerged Structure)

LOCA(Building Inertia)LOCA(Submerged Structure)

LOCA(TipLoad)0%0%2%0%60%38%(Negligible)

(Negligible)

(Negligible) 100%

~BracinkTable3.2alsoprovidesthestressmarginand%contribution tothetotalstressforeachloadforthemosthighlystressedbracingmemberadjacenttotheRHRSRVdischarge.

This.tableindicates thestressmargintobe92%,withallloadsexceptLOCAresulting innegligible stresses.

"Eliminating allloads,exceptseismic,asbefore,increases thestressmarginto100%.LinerPlateTheworst-case suctionloadoccursduringnon-LOCAconditions, sinceaLOCAresults'n apressurized wetwellairspace.

Thisnetpositivepressureoccursstatically andexceedsthesumofalldynamicsuctionloadscausedbySRV(ADS)+LOCAchugging.

Fornon-LOCAconditions, thelinerplatewasevaluated forthehydrostatic

+SRV(ALL).

But,whenconsidering thesuctionloadsonthelinerplateduetoRHRSRVdischarge, theSRV(ALL)mechanistically neednotbecombined.

Asdescribed above,cyclingofthelowsetpressure SRVsresultsinamuchlowersuctionloadtobecombinedwiththeRHRSRVsuctionload.Basedontheabove,muchconservatism existsinthesubmerged structures adjacenttotheRHRSRVdischarge.

Ourpreliminary evaluation ofthevariousRHRSRVdischarge loadswhenconsidering theabovedesignmarginsisprovidedbelow.TheRHRSRVdischarge phenomena causesseveralconcernsasfollows:waterjetloadduringventclearingairbubbleloadsduringventclearingsteamcondensation loadspotential highamplitude steamcondensation loadsoriginating fromhighwatertemperature inthevicinityoftheRHRSRVdischarge.

WaterJetLoadTherearenosubmerged structures inthevicinitybeneaththeRHRSRVdischarge.

Therefore, loadsresulting fromacolumnofwaterbeingejectedfromthedischarge linearenotaconcern.AirBubbleLoadsLoadsontheworst-case adjacentsubmerged structures andlinerplate(seeTables3.1and3.2)duetotheRHRSRVairbubbleloadareconsidered tobeboundedbythoseproducedbytheMSRVloadusedfordesign.Thisisbasedoncomparing theparameters oftheRHRSRVdischarge tothoseoftheMSRVs:

ur't oTheRHRdischarge linevolumeissmallerthantheMSRVdischarge, therefore, theairbubbleanditsresultant energywouldbesmaller.oTheRHRSRVopensmoreslowlythantheMSRV,decreasing theairbubbleloading.oAspreviously explained, themassfluxthroughtheRHRSRVdischarge linewillbemuchlessthanthetheoretical maximumsteamfluxbasedontheratedflowthroughtheRHRSRV.ThisresultsinalowerbubblepressurerelativetotheMSRVload.oTheRHRSRVdischarge linesubmergence isapproximately 6'thighnormalwaterlevel,ascomparedtoaT-quencher submergence of20.5'orhighnormalwaterlevel.ThisresultsinareducedventclearingpressurerelativetotheMSRVload.Inaddition, aspreviously described, thesubmerged structures andlinerplatecontainsufficient designmargintoaccommodate anyincreaseinthestressesduetoRHRSRVdischarge.

Specifically, forthebracinganddowncomer theRHRSRVbubbleloadmustexceedthestressesduetoSRV(ADS)+LOCA+DESIGNMARGINtoresultinanoverstressed condition.

Similarly, fornon-accident conditions, theRHRSRVsuctionloadmustexceedthehydrostatic

pressure, andthelinerplateallowable stress,ifweassumethe'suctionloadduetocyclingof.,thelowsetpressure MSRVtobenegligible.

SteamCondensation LoadsIThesteamflowthroughtheRHRSRVresultsinsteam'ondensation loadsatthedischarge pipe.Again,thesteammassfluxthroughtheRHRSRVforeitherfailuremodewillbemuchlessthanthesteady-state steammassfluxbasedontheratedflowoftheRHRSRV.Ourpreliminary analysisindicated thattheexpectedsteammassfluxandassociated steamcondensation loadsresultedinstresseswithinthecodeallowables.

Aswiththeairclearingload,significant designmarginexistsinthesubmerged structures andlinerplate,whichwebelieveexceedstheRHRSRVsteamcondensation loadwhencombinedwiththeappropriate loads.HihPoolTemeratureEffectsExperimental datahasshownthatsteamdischarge intowaterthatisataveryhighlocaltemperature canproducecomparatively largeloads.Basedonourpreliminary estimates ofRHRSRVsteamflux,anRHRSRVdischarge eventwillnotenterintosucharegime,sinceitisconsidered thatthesteamflowwillbeterminated priortosignificant localheatupintheareaofthedischarge.

Aspreviously described, theoperatorhasseveralindications fromwhichtodetermine whetheranuncontrolled discharge ofsteamthroughtheRHRSRVexists.Weassumehedetectsandisolatesthe 1[<

r(SCMat10minutesafter,thefailurethatoccurswhichleadstotheRHRSRV:discharge.

Basedontheabove,webelievethewaterget,airclearing, andsteamcondensation loadsonthesubmerged structures andlinerplateduetoRHRSRVdischarge, whencombinedwiththeappropriate loads,arewithintheSSESdesignbasis.III.FutureActionReuired1.Calculate theloadsonthesubmerged structures andlinerplateduetotheRHRSRVairclearingphenomena whencombinedwiththeappropriate loads.Comparethesestressestothecodeallowables.

2.Confirmourpreliminary analysisthattheRHRSRVsteamcondensation loadsresultin'acceptable stressesonthelinerplateandadjacentsubmerged structures.

3.Performpoolheatupcalculation duetoRHRSRVdischarge toverifythatthelocaltemperature neartheRHRSRVdischarge remainsbelowthetransition temperature forunstablesteamcondensation phenomena.

4.DocumentabovetotheNRCbyMarch31,1983.

I.Issue3.2TheSTRIDEdesignprovidedonlynineinchesofsubmergence abovetheRHRreliefvalvedischarge linesatlowsuppression poollevels.II.Assessment/Res onseInterpreting, this'asaconcernofdirect'team discharge towetwellenvironment,'or SSEStheRHRlineissubmerged,3.5'elow theLNWL,hencethisisofnoconcerntoSSES.III.FutureActionReuired<lgNone I.Issue3.3Discharge fromtheRHRreliefvalvesmayproduceairbubbledischarge orothersubmerged structure loadsonequipment inthesuppression pool.II.Assessment/Res onseSeeresponseto3.1.III.FutureActionReuiredSeeresponseto3.1.

IS' I.Issue3.4TheRHRheatexchanger reliefvalvedischarge linesareprovidedwithvacuumbreakerstopreventnegativepressureinthelineswhendischarging steamiscondensed inthepool.Ifthevalvesexperience repeatedactuation, thevacuumbreakersizingmaynotbeadequatetopreventdrawingslugsofwaterbackthroughthedischarge piping.Theseslugsofwatermayapplyimpactloadstothereliefvalveorbedischarged backintothepoolatthenextreliefvalveactuation andapplyimpactloadstosubmerged structures.

II.Assessment/Res onseSSEShasperformed arefloodanalysistocalculate themaximumheightofreflood(i.e.,waterslug)andconsequential impactloadsontheRHRSRVdischarge pipingfollowing subsequent actuations oftheRHRsteamreliefvalve.Hydrodynamic loadsonsuppression poolsubmerged structures aredescribed intheresponseto3.1.Thisanalysisshowsthatthereflooddoesnotreachthevacuumbreaker(VRV)ortheRHRSRV.Therefore, animpactloadontheVRVorSRVduetoawaterslugdoesnotoccur,andtheVRVsizingisshowntobeadequate.

II.FutureActionReuiredNone IIVJgg 3.5TheRHRreliefvalvesmustbecapableofcorrectly functioning following anupperpooldumpwhichmayincreasethesuppression poollevelasmuchas5ftcreatinghigherbackpressureonthereliefvalves.II.Assessment/Res onseTheNRCdispositioned thisconcernasN/AforSSES.III.FutureActionReuiredNone 1JUi1ecII I.Issue3.6IftheRHRheatexchanger reliefvalvesdischarge steamtotheupperlevelsofthesuppression poolfollowing adesign'asis

accident, theywillsignificantly aggravate suppression pooltemperature stratification.

II.Assessment/Res onseSteamcondensing isnotasafetymodeofRHRandisnotusedpost-accident.

Itmaybeused"duringnormalreactorshutdownmodeforhotstandbyorvesseldepressurization operations.

'hemodeoperatesbydrawingsteamfromtheHPCIsteamsupplyline;condensing intheRHRheatexchanger, andreturning thecondensate tothevesselviatheRCICpump.Thereliefvalvesdischarge 3.5'elowthepoolsurface(ratherthan9"asintheMarkIII,design).

IftheRHRsystemwasinth'ismodewhenaLOCA(whileshutdown)

occurred, theredundant, inseries,safety-grade steamsupplyvalveswillautomatically close(seeresponseto3.1).Inothersafety-related modes'ofoperation, theRHRsystempressureis,atalltimes,lowerthanthereliefvalvesetpoint.

However,asingleactivefailure(open)ofthereliefvalvecouldbepostulated whiletheRHRSystemisoperating post-LOCA.

IfthesystemwasintheLPCI,suppression poolcooling,orcontainment spraymodes,thewatersourceisthesuppression pool;therefore, notemperature stratification couldoccur.Theshutdowncoolingmode(whichcouldbeinoperation afteranSBA)isinterlocked fromoperation untilvesselpressureisbelow98psig.Inthiscasethereactorhasalreadybeendepressurized andthepoolhas,therefore, alreadyperformed itspressuresuppression safetyfunctionsothatanypresumedtemperature stratification effectswouldbeofnoconsequence.

Finally,theresponseto4.4indicated thatthermalstratification posesnoproblemsforequipment locatedinthewetwellairspace, sincetheywerequalified todrywellconditions.

III.FutureActionReuiredNone15-C1"7I" I.IssueI3.7TheconcernsrelatedtotheRHRheatexchanger reliefvalvedischarge linesshouldalsobeaddressed forallotherECCSrelieflinesthatexhaustintopool(p.132of5/27/82transcript).

II.Assessment/Res onseTherearenootherECCSrelieflinesthatdischarge tothesuppression poolotherthansmallthermalreliefs.III.FutureActionReuiredNone ll4yr 4.SuressionPoolTemeratureStratification 4.1Thepresentcontainment responseanalysesfordrywellbreakaccidents assumethattheECCSsystemstransferasignificant quantityofwaterfromthesuppression pooltothelowerregionsofthedrywellthroughthebreak.Thisresultsinapoolinthedrywellwhichisessentially isolatedfromthesuppression poolatatemperature ofapproximately 135'F.Thecontainment responseanalysis"assumesthatthedrywellpoolisthoroughly mixedwiththesuppression pool.Iftheinventory inthedrywellisassumedtobeisolatedandtheremainder oftheheatisdischarged tothesuppression pool,anincreaseinbulkpooltemperature of10'Fmayoccur.Footnote1:thedrywell.ThisconcernisrelatedtothetrappingofwaterinII.Assessment/Res onseForSSES,theamountofwater"trapped" inthedrywellislimitedtothe18"ventrisersinthedrywell.Thisrepresents amuchsmallerproportion ofthesuppression poolwatermassthanforaMarkIIIcontainment design.Thisconcernpotentially affectsthetwocontainment analysesusedforlicensing SSES:oThecontainment analysisdocumented inSection6.2oftheFSAR.toTheMass6Energyanalysisdocumented inAppendixIoftheSSESDesignAssessment Report(DAR).Ourreviewofthecontainment analysisdocumented inSection6.2oftheFSARindicated thattrappingofthesuppression poolwaterinthedrywellwasnotconsidered.

However,webelievetheconservatisms inthecontainment analysisexceedthepotential non-conservatism duetotheaboveconcern,-

basedonthefollowing:

oTheanalysisneglected boththesteamcondensation onthedrywellstructures, aswellastheheattransferfromsuppression pooltothecontainment walls.oTheanalysisassumedaservicewatertemperature of95'Ffortheentiretransient.

TheTechnical Specifications limittheinitialservicewatertemperatures to88'F.In'addition, asexplained intheresponseto4.6,ourservicewaterspraypondanalysisindicates thattheworst-case servicewatertemperature neverexceeds92.25'FwithoneunitinLOCAcondition andtheotherunitinforcedshutdown.

d1(IIPHll oFinally,thedecayheatcurveassumedintheanalysiswasveryconservative.

Themorerecentcurvesprovideforalowerintegrated decayheatfortheanalysis.

TheMass&Energyanalysisdocumented inAppendixIoftheSSESDARwascompleted toverifythatthescenarios (i.e.,stuckopenreliefvalve,isolation/scram, andsmallbreakaccident) whichleadtoabnormally highsuppression pooltemperature, coincident withmainsteamSRVactuation andsteamflowthroughtheT-quencher, wouldnotresultinasuppression pooltemperature responsewhichexceedsthemaximumpooltemperature of207'Fstipulated bytheNRCforsafeT-quencher operation.

Ofthesescenarios, onlytheSBAcasesresultinabreachofthereactorpressurevessel,withthepotential fortrappingsuppression poolwateronthedrywellfloor.TheSBAcasedidnotconsidertheeffectsofareduction inthesuppression poolwaterduetodrywelltrapping.

Ourassessment ofthisconcernisprovidedbelow.TableI-2oftheDARindicated amaximumcalculated suppression pooltemperature of193'FfortheSBACase3.a.Thus,thereexistsamarginof207-193=14'Fforthiscase.AswiththeSection6.2analysis, theoriginalMass8Energyanalysiscontained numerousconservatisms asdescribed below:oTheanalysisneglected thewatermasswithinthepedestal.

Thiswaterisapproximately

.5.7%ofthewater'mass usedintheanalysis.

oTheanalysistooknocreditforenergyabsorbedbythecontainment structure.

oAgain,theanalysisassumedaservicewatertemperature of95'F.Forbothscenarios, thecalculated pooltemperature considering thewatertrappedinthedrywellwouldnot'increase bythesamepercentdecreaseinpoolwaterlosttothedrywell(i.e.,1%decreaseinpoolmassequals1%increaseinpooltemperature).

Thatis,thewatertrappedinthedrywellwouldabsorbsomeenergyfromthereactorsystem.Basedontheabove,webelievethisissueposesnoconcernsforSSES.III.FutureActionReuiredNone lajf,JI' I.Issue4.2Theexistence ofthedrywellpoolispredicated uponcontinuous operation oftheECCS.Thecurrentemergency procedure guidelines requiretheoperations tothrottleECCSoperation tomaintainvessellevelbelowlevel8.Consequently, thedrywellpoolmayneverbeformed.Footnote2:Thisissueappliesonlytothosefacilities forwhichEPGsareineffect.II.Assessment/Res onseTheSSEScontainment responseanalysisdoesnotdependontheformation ofa"drywellpool."Asdescribed

.intheresponseto4.1,thewatertrappedinthedrywellislimitedtothe18"'allventriser's.'f'th'drywellpoolisnotformed,as,postulated

herewith, thentheactualpooltemperature responsewouldbeconsistent withthecontainment analysisdocumented inSection6.2oftheFSAR,andtheMass5Energyanalysisdocumented inAppendixIofthe.DAR.1III.FutureActionReuiredNone I.Issue4.3AllMarkIIIanalysespresently assumeaperfectly mixeduniformsuppression pool.Theseanalysesassumethatthetemperature ofthesuctiontotheRHRheatexchangers isthesameasthebulkpooltemperature.

Inactuality, thetemperature inthelowerpartofthepoolwherethesuctionislocatedwillbeasmuchas7-1/2'Fcoolerthanthebulkpooltemperature.,

Thus,theheat-transfer throughtheRHRheatexchanger willbelessthanexpected.

II.Assessment/Res onseAsshowninFSARFigure5.4-4b,theRHRpumpsuctionpenetrates theSSEScontainment atEl.10'bovethebasemat,andthenT'svertically withsuctiontakenateachendoftheTapproximately 8'nd12'bovethebasemat.Thiselevation corresponds tothemid-plane ofthepooland,therefore, weexpecttheRHRpump,suctiontemperature tobe'atleastthebulkpooltemperature'.

Asaresult,thisconcerndoesnotapplytotheSSESdesign.III.FutureActionReuiredNone

)4'NlI I.Issue4.4Thelong-term analysisofcontainment pressure/temperature responseassumesthatthewetwellairspaceisinthermalequilibrium withthesuppressi'on poolwateratalltimes.Thecalculated bulkpooltemperature isusedtodetermine theairspacetemperature.

Ifpoolthermalstratification wereconsidered, thesurfacetemperature, whichisindirectcontactwiththeairspace, wouldbehigher.Therefore, theairspacetemperature (andpressure) wouldbehigher.II.Assessment/Res onseIncontrasttoaMarkIIIcontainment design,theSSESpeakpressureresponsetoaDBAoccursatapproximately 15secaftertheaccidentbegins(seeFSARFigure6.2-2andTable6.2-5).Therefore, potential poolthermalstratification willhavenoeffectontheshorttermcontainment pressureresponse.

Thisconcernalsomayincreasethewetwellairspacetemperature response.

ForSSES,thisposesnoconcerns, sinceallequipment locatedintheairspacehasbeenqualified tothedrywelltemperature profile(maximumtemperature equalto340'F)whichenvelopes anypotential increases inthesurfacepooltemperature.

III.FutureActionReuiredNone Issue4.5Anumberoffactorsmayaggravate suppression poolthermal'stratification.

Thechuggingproducedthroughthefirstrowofhorizontal ventswillnotproduceanymixingfromthesuppression poollayersbelowthe.ventrow.Anupperpooldumpmaycontribute toadditional suppression pooltemperature stratification.

Thelargevolumeofwaterfromtheupperpoolfurthersubmerges RHRheatexchanger effluentdischarge whichwilldecreasemixingofthehotter,upperregionsofthepool.Finally,operation ofthecontainment sprayeliminates theheatexchanger effluentdischarge jetwhichcontributes tomixing.Footnote3:ForMarkIandIIfacilities,'onfine yourresponseonthisissuetothoseconcernswhichcanleadtopoolstratification (e.g.,operation ofthecontainment spray).II.Assessment/Res onseInSSES,thecontainment sprayfallstothediaphragm floor,flowsthroughthedowncomers andexitsatthemid-plane ofthepool,approximately 12'bovethebasemat.Thus,webelievecontainment spraywillnotaggravate anypoolstratification.

Inaddition, as,described intheresponseto4.4,anypoolthermalstratification hasnoeffectontheSSEScontainment design.III.FutureActionReuiredNonekP PIP I.Issue4.6Theinitialsuppression pooltemperature isassumedtobe95'Fwhilethemaximumexpectedservicewatertemperature is90'FforallGGNSaccidentanalysesasnotedinFSARTable6.2-50.Ifthe'ervice watertemperature isconsistently higherthanexpected, asoccurredatKuosheng, theRHRsystemmayberequiredtooperatenearlycontinuously inordertomaintainsuppression pooltemperature atorbelowthemaximumpermissible value.II.Assessment/Res onseAsstated,thisissueappearstobeanoperational concernandisnotrelatedtothesafeoperation oftheplantsincecontinuous, frequentoperation oftheRHRandservicewatersystemsdoesnotaffectthesafeoperation oftheplant.Theinitialsuppression pooltemperature isassumedtobeat90'FforSSESaccidentanalysis.

RHRSWisusedtocoolthesuppression poolwhichtakessuctionfromthespraypond.Thespraypondhasanareaof'8acresandadepthof10-1/2ftwithamaximum'designtemperature of88'F(FSARTables9.2-2789.2-23).Thistemperature isbasedonaveryconservative analysisofsitemeteorology andassumesthatallthewaterinthespraypondwillreachtheworstambienttemperature withoutconsidering theeffectsoftemperature,'stratification inthepond.Ourspraypondanalysisshowsthateve'nforthelong-term post-accident condition withoneunitintheLOCAcondition andtheotherunitatforcedshutdown, themaximumpondtemperature isonly92.25'F(FSARTable9.2-12)fortheminimumHeatTransfercase.Wedonotexpectthebulktemperature ofspraypondtoexceed88'F.TheTechnical Specifications requirethattheplantbeinshutdowncondition iftheaveragepondtemperatures exceed88'F.Inaddition, theTechnical Specifications requireasuppression pooltemperature below90'F(exceptduringtestingwhichaddsheattothepool).Ifthepooltemperature exceeds90'F,theTechnical Specifications directtheoperatortorestorethetemperature tolessthanorequalto90'Fwithin24hoursorbeinatleasthotshutdownwithinthenext12hoursandincoldshutdownwithinthefollowing 24hours.Thus,iftheSWandRHRsystemsfailtomaintainthepooltemperature below90'Fduringhotweather,thentheplantwillbebroughttoanorderlyshutdown, andthisconcernbecomesanoperational problem.III.FutureActionReuiredNone 4t I.Issue4.7Allanalysiscompleted fortheMarkIIIaregenericinnatureanddonotconsiderplantspecificinteractions oftheRHRsuppression poolsuctionanddischarge.

II.Assessment/Res onseThesketchonthenextpageshowstherelativepositions ofRHRsuctionanddischarge.

Thisconfiguration eliminates anyconcernwiththedischarge effluentshortcircuiting thepoolandassuresadequatepoolmixing.III.FutureActionReuiredNone 0

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I.Issue4.8Operation oftheRHRSysteminthecontainment spraymodewilldecreasetheheat'transfer coefficient throughtheRHRheatexchangers duetodecreased systemflow.TheFSARanalysisassumesaconstantheattransferratefromthesuppression poolevenwithoperation ofthecontainment spray.II.Assessment/Res onseThisissueisinterpreted asbeingconcerned withthepotential forincreased bulkpooltemperature andcorresponding wetwellairspacepressureandtemperature.

Asdiscussed intheresponseto4.4,thepeakcontainment pressureisgovernedbytheshort-term DBALOCAresponse, andnotbythelong-term response.

Also,asdiscussed intheresponseto4.4,theonlyconcernrelatedtoincreased suppression pool/wetwell airspacetemperatures hastodowithenvironmental qualification.

Sinceequipment inthewetwellhasbeenqualified todrywelltemperature conditions, whichboundsthewetwellconditions, anypresumeddecreaseinheatremovalratefromthesuppression poolisnotofconcern.Nevertheless, itcanbedemonstrated thattheoperation ofcontainment sprayswouldhavenegligible effectonpeakbulksuppression pooltemperature.

AsopposedtothestandardMarkIIdesignwherecontainment sprayandsuppression poolflowratesareidentical, SSEShasasmaller(9000gpm)containment sprayratethansuppression poolcoolingflowrate(10,000gpm).However,asshowninFSARTable6.2-6,,the worst-case suppression poolpeaktemperature occurswhennocontainment sprayisassumed(Case"D"),i.e.,theRHRsystemisalwaysinthesuppression poolcoolingmode.AlthoughthevaluesinFSARTable6.2-6werecalculated priortothemodification thatresultedinthedecreased containment sprayrate,itcanbeseenthatanominalchangeinsprayflowratehaslittleeffectonpeakpooltemperature.

Comparing Case"B"toCase"C"(allspraycases)wheresprayflowrateisdecreased by5000gpm,itisseenthatthepooltemperature increases byonly3.1'F.Adecreasefrom10,000gpmto9000gpm,then,wouldleadtoaninsignificant changeinpooltemperature, andwouldclearlybe'ounded bythe'eak(nospray,Case"D").temperature of208.2'F.III.FutureActionReuiredNone ltI11fI'h I.Issue4.9Theeffectonthelong-term containment responseandtheoperability ofthespraysystemduetocyclingthecontainment spraysonandofftomaximizepoolcoolingneedstobeaddressed.

Alsoprovideandjustifythecriteriausedbytheoperatorforswitching fromthecontainment spraymodetopoolcoolingmode,andbackagain(pp.147-148of5/27/82transcript).

II.Assessment/Res onsetOurassessment oftheaboveconcernisprovidedbelow:1.Containment PressureResponse"Asdiscussed in4.4,thepeakpressureresponsetoaDBAoccursduringtheshort-term blowdown.

Forthelong-term pressureresponse, theresponseto4.8indicated thatSSES'analyzed forboththeallsprayandnospraycases.Bothcaseswereacceptable.

Thesecasesenvelopthecontainment responseduetocyclingthecontainment spraysonandoffaspostulated above.2.Suppression PoolTemperature ResponseForSSES,thecyclingofthecontainment spraystomaximizepoolcoolingisnotrequired.

Again,asdiscussed under4.8,boththeallsprayandnospraycaseswereevaluated.

FSARFigure6.2-8indicates thateithercaseresultsinanacceptable pooltemperature response.

Thus,thesetwocasesenvelopethepooltemperature responsetoanypotential cyclingfrompoolcoolingtothesprays.Inaddition, emergency procedure

'E0-00-023, "Containment Control,"

providesthecriteriaforoperation ofthespraymodeorpoolcoolingmodeoftheRHRsystem.Theprocedure waspreparedfrom.theemergency procedure guidelines.

developed bytheBWROwnersandGE.Thisprocedure requiresinitiation ofpoolcoolingwhenthesuppression pooltemperature exceeds90'F,andisthepreferred modeforcontainment heatremoval.However,theprocedure requiresinitiation ofthedrywellandsuppression poolsprays,ifthecontainment temperature andpressureexceedpredetermined values.ForSSES,beforethedrywelltemperature reaches340'F,but'fterdrywelltemperature reaches320'F,theprocedure directstheoperatortoinitiatethedrywellsprays.Theprocedure directstheoperatortoinitiatewetwell,spraywithin30minutesofreaching30psigdrywellpressure.

Thisactionisrequiredtobeconsistent withtheSSES-unique steambypassanalysis.

g4tPd1,I Inaddition, theprocedure directstheoperatortoinitiatesuppression poolspray,ifthesuppression poolchamberpressureapproaches theSuppression PoolSprayLimit(seefigurenextpage).Furthermore, theprocedure directstheoperatortoinitiatedrywell'sprays, ifthesuppression chamberpressureapproaches thePressureSuppression Limit(seefigurenextpage).TheSuppression PoolSprayLimitinsuressuppression poolspraybeforereaching50%ofthesuppression chamberdesignpressure.

ThePressureSuppression Limitinsuresdrywellsprayinitiation beforesuppression chamberpressureindicates thatpressuresuppression hasbecomeineffective.

Toaccommodate anyrequiredcyclingofthecontainment sprays,theRHRsystemandpipinghavebeendesignedforapproximately 7,000thermalcycles.III.FutureActionReuiredNone s.s'sIr~Is~~s~srQr;~rQ.)~rCS~~Le,cl.r~r}~~~gr'ss~,~s5"~2Page1of1Attachment CEO-00-023 Revision1Page9of18SUPPRESSION POOLSPRAYLIMITr~&s}'.II}ss}'}~'i-}.I~~~II.I}/rsrrsrs~rIss/ss},~~i'rs~.~rLu~~'rs~Xa)JIs~~sss'Is1~.I/'SrI~~r~s~~s~~)isssIs~I!iiis~Is~s~;r1sI.';I's)Ir.'s~Ir'.~.~!ss!r"I})iI~s~IsI)s~s},'Ss~~I/')'"~~s'.is})I'II}I}s:}r,",)II~,sssS~I!'i')}}ss},Isr~~r~IIIs~s~s~i:Is~.III!lrrIs'~"i//rl)ir..~//C')rIssi)i.iI'!1;II.',~)I!ss~rr,'rsIsSrsss.sr~~i:ss',:iI~/I'-.I';..':.:.IIi::s.I//'IsssssIs~sr~irs,srr8~i'!II~s'I~~srippreaag,o~} O@zest'I~~sssr'~ssss}~2naLLevej (t}r1 J Attachment D.EO-00-023 Revision1Pagellof18PRESSURESUPPRESSION LIMITgs~'I~~IS'sr.~sr')<<4-'.isvsoee'li~~~~If,sII!isIIIrs~~~(,i/~rv~osSI4vv\e+e~~~rII'8~-~~~V~eq,pv<<os~'s~',~e+ovosS~~/~rIi'I,JI~J~SW~sril~I.>>Y."~'--'~I~,~'I(~I~!I~I+siIIslIi~\I,s()sDosi!~~IlI.I'!iJlI/I!i~!iI(J';!~!!:IIIIt~I!~Jr+I~~C(oI!sss)I~~~II~7IsiIl'!iIII(I'iIIIl'!!tI'I!!':II',.iII'(Ii!!'~:!i;!sQCOIIII'!i!!.'E.IIiIi'.!riil.l.Lvii!I!iII~~!it!~sIII'II~!liI~l~~I,~~~IiI~I'I'l~lIsI.'!I,iit~!~IIIIs~I~Il~"~I~:.0-,F'."20':2eeeeeeePssppzeee)sse, Lied.".i!.!'.III~~i!t!~I,~!".0'"'45-.'50..5;rI~zfea~coatafxmenk Wate~ve3D~/s e I.Issue4.10Justifythatthecurrentarrangement ofthedischarge andsuctionpointsofthepoolcoolingsystemmaximizes poolmixing."II.Assessment/Res onseThefiguresattachedtotheresponseto4.7showtherelativepositions oftheRHRsuctionanddischarge. ThesefiguresindicatetheRHRdesignwillprovideadequatepoolmixing.III.FutureActionReuiredNone lQiJ I.Issue5.DrywelltoContainment BypassLeakage5.1Theworst-case ofdrywelltocontainment bypassleakagehasbeenestablished asasmallbreakaccident. Anintermediate breakaccidentwillactuallyproducethemostsignificant drywelltocontainment leakagepriortoinitiation ofcontainment sprays.,II.Assessment/Res onseAsrequiredbySection6.2.1.1.c oftheStandardReviewPlan,PP&Lcompleted asteambypassca/culation forapostulated steam,bypassareaofA//Kequalto0.0535ftforSBAconditions. PLA-923datedSeptember 3,1981,transmitted toyoutheresultsofthesecalculations. TheSBAconditions providedaconservative analysisbasedonthefollowing: oTheanalysismaximized thedrywell-to-wetwell AP,whichdrives'he steamintothewetwellairspace. Fromllsecafterthebreakoccurs,itassumedthatpuresteamatadrywell-to-wetwell APequaltotheventsubmergence wasavailable forsteambypass.oTheanalysisalsomaximized thetimeperiodoverwhichthesteambypassoccurred. Itassumedthatnovesseldepressurization

occurred, andthatthedrywell-to-wetwell APequaltothesubmergence existedfortheentiresteambypasscalculation.

Theanalysisindicated thatsufficient timeexistsforthecontainment pressuretogofrom30psigtothedesignpressureof53psigfortheoperatortomanuallyinitiatethecontainment spray.Onceinitiated, thesprayheatremovalrateissufficient toterminate thecontainment pressureincrease. Furthermore, Supplement No.3totheSSESSafetyEvaluation Reportdocumented yourreviewandacceptance oftheaboveanalysis. III.FutureActionReuired'one I.Issue5.2UnderTechnical Specification limits,bypassleakagecorresponding toA/MK=O.lftconstitutes acceptable operating conditions. Smaller-than-IBA-sized breakscanmaintainbreakflowintothedrywellforlong-time periods,however,becausetheRPVwouldbedepressurized overa6-hourperiod.Given',forexample,anSBAwithA/~K=0.1,projected timeperiodforcontainment pressuretoreach15psigis2hours.Inthelatter4hoursofthedepressurization thecontainment wouldpresumably experience ever-increasing overpressurization. Footnote4:ForMarkIandIIfacilities, refertoAppendixItoSection6.2.1.1.c oftheStandardReviewPlan(SRP).II.Assessment/Res onseAsdescribed intheresponseto5.1,PPSLperformed aSSESuniquesteambypasscalculation pertherequirements ofAppendixItoSection6.2.1.1.c oftheSRP.Thesecalculations assumednovesseldepressurization andadrywell-to-wetwell APequaltothesubmergence forthedurationofthetransient. Thisanalysis, asanysteambypasscalculation would,showedthatthe"containment wouldpresumably experience ever-increasing overpressurization," ifnocontainment sprayinitiation occurred. However,whentheoperatorinitiates thecontainment sprays,thepressureincreaseterminates. The.subjectanalysisshowedthatsufficient timeexistsfor'theoperator. toinitiatethecontainment sprays,whilethecontainment'pressure increases from30psigtothedesignpres'sure'of 53'psig.NfIIII.FutureActionReuir'ed'one I.Issue5.3Leakagefromthedrywelltocontainment willincreasethetemperature andpressureinthecontainment. Theoperators willhavetousethecontainment sprayinordertomaintaincontainment temperature andpressurecontrol.Giventhedecreased effectiveness oftheRHRsysteminaccomplishing thisobjective inthecontainment spraymode,thebypassleakagemayincreasethecyclicaldutyofthecontainment sprays.II.Assessment/Res onseTheresponses to4.8and4.9discussed theeffectsonthelong-term containment analysisofcyclingtheRHRsystembetweenthesprayandpoolingmodes.Asnotedthere,theSSEScontainment designcanaccommodate eitherallornosprayswithnoadverseeffectsonthelong-term containment transients. Thesecasesenvelopethecontainment responsewithcyclingofthecontainment sprays.Furthermore, ifsteambypassrequirescyclingbetweenthespraysandpoolcooling,thesystemdesignwillnotsuffer,sincethespraysweredesignedforupto7000thermalcycles.III.FutureActionReuiredNone 'lll I.Issue5.4Directleakagefromthedrywelltothecontainment maydissipate hydrogenoutsidetheregionwherethehydrogenrecombiners takesuction.Theanticipated leakageexceedsthecapacityofthedrywellpurgecompressors. Thiscouldleadtopocketing ofhydrogenwhichexceedstheconcentration limitof4%byvolume.Footnote5:Thisconcernappliestothosefacilities atwhichhydrogenrecombiners canbeused.II.Assessment/Res onseInSSES,twohydrogenrecombiners arelocatedinthedrywellandtwointhewetwellairspace. Foraninertedcontainment suchasSSES,thepertinent concentration limitis5%oxygen.Whileoperating thedrywellrecombiners, drywellmixingisprovidedbyoperating thesafety-related drywellfans.Forthewetwellairspace, pocketing ofhydrogenisnotexpected, sincetheairspaceisalarge,unpartitioned, openvolume.However,mixinginthewetwellcanbeaccomplished byoperation ofthewetwellsprays.III.FutureActionReuiredNone32 I.Issue5.5Equipment maybeexposed,to localconditions whichexceedtheenvironmental qualification envelopeasaresultofdirectdrywelltocontainment bypassleakage.II.Assessment/Res onseAsexplained intheresponseto4.4,allequipment locatedinthewetwellairspacehasbeenqualified todrywellconditions, whichenvelopeanyconcernsduetodrywell-to-wetwell bypassleakage.III.FutureActionReuiredNone I'tlI/lg I.Issue5.6and5.7II.Assessment/Res onseDispositioned bytheNRCasnotapplicable forMarkII.III.FutureActionReuiredNone I.Issue5.8Thepossibility ofhightemperatures inthedrywellwithoutreachingthe2psighighpressurescramlevelbecauseofbypassleakagethroughthedrywellwallshouldbeaddressed (pp.168-174of5/27/78transcript). II.Assessment/Res onseThedrywelldesigntemperature is"governed byasmallreactorsteambreak.TheFSARSBAanalysis(seeSection6.2.1)demonstrates ittakesabout6hourstoceasereactorblowdownfollowing anSBAwhichisaccomplished byanorderlyreactorshutdownwithacooldownratelimitedto100'Fperhour.Duringthisblowdownperiod,steamenteringthedrywellisinasuperheated condition duetoconstantenthalpydepressurization ofhighpressuresaturated steam.Thedrywelldesigntemperature isdetermined byfindingthecombination ofprimarysystempressureanddrywellpressurethatproducesthemaximumsuperheated steamtemperature. Thistemperature isthenassumedtoexistfortheentiresix-hourperiod.Theresultant maximumsuperheated steamtemperature is340'Fcorresponding totheprimarysystempressureofapproximately 450psiaandanassumedmaximumdrywellpressureof35psig.This340'Fistherefore chosenasthedrywelldesigntemperature. Considering apostulated smallbreakwithoutinitiating automatic highdrywellpressurescrambecauseofbypassleakage,itwouldnotbepossibletoexceedthecurrentdesigntemperature forthefollowing reasons:1.TheSSESTechnical Specifications limitofdrywellpressureis-1psigto+2psig.Thescramsetpointis1.72psig.Thepost-SBAshort-term transient withoutinitiating scramat1.72psigdrywellpressureisonlypossibleforacaseof"smaller-than-small-break -size"inwhichsteamisweepingintothedrywellanddrivingnon-condensables intowetwellthroughthepotential leakagepaths.Duetothisbyp'assleakageeffectfollowing asmaller-than-small-break',anautomatic drywellpressurescramcouldbedelayedforthetimeneededtoslowlypressurize thedrywelltothe1.72psigscramlevel.Thereactorsteam,.entering thedrywellpriortotheinitiation ofscram,.is in'thesuperheated condition whichislessthan340'Fpredicted inFSARanalysis. (Forexample,asnotedinFSARSection6.2.1,decompression of1000psiasaturated steamintoatmosphere willresultin298'Fsuperheated steam.)Therefore, thedrywelltemperature couldnotexceedthecurrentdesigntemperature. 2.Anysignificant temperature excursion thatcouldresultfromsuchapostulated eventwillbeprevented byoperatoraction.TheoperatorisrequiredbytheTechnical Specifications tomaintainthedrywellairspacetemperature below135'F.Ifthetemperature risesandexceeds135'F,emergency operating procedure E0-00-023, "Containment Control," requirestheoperatortostartallavailable drywell Tipltf coolers.Ifthedrywellcoolersareunabletoreducethetemperature, theemergency operating procedures requireinitiating thecontainment spraysforacontainment temperature between320and340'F.3.Finally,therewillbenosignificant delayofscram,sincerelatively smallbypassleakagecapacityexistsinaMarkIIdesign.Thus,thecontainment pressurewillreach1.72psiginashorttimeperiod.III.FutureActionReuiredNone~ I.Issue6.1Weunderstand thatGEhasrecommended forMarkIIIcontainments thatthecombustible gascontrolsystemsbeactivated ifthereactorvesselwaterleveldropstowithinonefootofthetopoftheactivefuel.Indicatewhatyourfacilityisdoinginregardtothisrecommendation. II.Assessment/Res onseThisisnotapplicable toSSES.Nosuchactionisrequired, sincetheSSEScontainment isinertedandshort-term Hcontrolisnotrequired. III.FutureActionReuiredNoneYt

I.Issue6.2GeneralElectrichasrecommended thataninterlock beprovidedtorequirecontainment spraypriortostartingtherecombiners becauseofthelargequantities ofheatinputtothecontainment. Incorrect implementation ofthisinterlock couldresultinaninability tooperatetherecombiners withoutcontainment spray.Footnote5:Thisconcernappliestothosefacilities atwhichrecombiners canbeused.II.Assessment/Res onseThereisnointerlock betweenthecontainment spraysandtherecombiners. III.FutureActionReuiredNone C-Nl I.Issue6.3Therecombiners mayproduce"hotspots"neartherecombiner exhaustswhichmightexceedtheenvironmental qualification envelopeorthecontainment designtemperature. Footnote5:Thisconcernappliestothosefacilities atwhichrecombiners canbeused.II.Assessment/Res onseTheSSESdesignhasaccounted forrecombiner "hotspots."Therecombiners areofanaturalcirculation typedesignwithhotairexhausted fromthetop,sothat"hotspots"arelimitedtothelocalareadirectlyabovetherecombiners. Inthedrywellnoequipment exceptacabletrayisneartherecombiner exhaust.Thecabletrayhasbeenprovidedwithdeflectors whicharedesignedtoinsulatethecabletrayandpreventitstemperature fromexceeding designlimits.Temperature measurements atthecabletraywhileoperating therecombiners haveverifiedthatthedesignandinstallation ofthedeflectors areadequate. Thewetwellrecombiners arelocatedatahighelevation directlybelowthediaphragm slab,andallequipment (suchasSPOTMOSRTDs)arelocatedbelowtherecombiners. Therefore, therearenoenvironmental qualification concerns. III.FutureActionReuiredNone

I.Issue6.4Forthecontainment airmonitoring systemfurnished byGeneralElectric, theanalyzers arenotcapableofmeasuring hydrogenconcentration atvolumetric steamcondensation above60%.Effective measurement isprecluded bycondensation ofsteamintheequipment. II.Assessment/Res onseThecontainment airmonitoring pipingisprovidedwithheattracing"poweredfromsafetygradesourcessothatnocondensation ofsteamwilloccur.NotethatSSESusesComsip-Delphi monitorsratherthanGEequipment. III.FutureActionReuiredNone I.Issue6.5Discussthepossibility oflocaltemperatures duetorecombiner operation beinghigherthanthetemperature qualification profilesforequipment intheregionaroundandabovetherecombiners. Statewhatinstruction's, ifany,areavailable totheoperatortoactuatecontainment spraystokeepthistemperature belowdesignvalues(pp.183-185of5/27/82transcript). 1Footnote5:Thisconcernappliestothosefacilities atwhichrecombiners canbeused.II.Assessment/Res onseEmergency operating procedure E0-00-023, "Containment Control," requirestheoperatortoinitiatetheH2recombiners beforeanH2concentration of3%byvolume.Withaninertedcontainment, thisoccurswithinapproximately 24hoursafterthebreakfortheworst-case analysis(seeFSARSubsection 6.2.5.3). Theheatoutputfromtherecombiners isasmallfractionofthe,totalheatinputtothecontainment fromthereactorvessel.Thus,recombiner operation willnotaffecttheglobaltemperature responseofthecontainment. Inaddition, asdescribed intheresponseto6.3,theSSESdesignconsidered thelocaleffectsofrecombiner operation. fl,Intheeventthecontainment temperature substantially increases, emergency operating procedure E0-00-023, "Containment Control," requirestheoperatortoactuatethedrywellspraysbeforethedrywelltemperature reaches340'F,butafterthedrywelltemperature reaches320'F.III.FutureActionReuiredNone J'AC1kg~IUAII40 I.Issue7.Containment PressureResonse7.1Thewetwellisassumedtobeinthermalequilibrium withaperfectly mixed,uniformtemperature suppression pool.Asnotedundertopic4,thesurfacetemperature ofthepoolwillbehigherthanthebulkpooltemperature. Thismayproducehigherthanexpectedcontainment temperatures andpressures. II.Assessment/Res onseReferto4.4.III.FutureActionReuiredNone I.Issue7.2ThecomputercodeusedbyGeneralElectrictocalculate environmental qualification parameters considers heattransferfromthesuppression poolsurfacetothecontainment atmosphere. Thisisnotinaccordance withtheexistinglicensing basisforMarkIIIenvironmental qualification. Additionally, thebulksuppression pooltemperature wasusedintheanalysisinsteadofthesuppression poolsurfacetemperature. Footnote6:ThisissueasphrasedappliesonlytoaMarkIIIfacility. However,theconcerncanbegeneralized andappliedtotheearliercontainment types.ForMarkIandIIfacilities, indicatewhatmethodology wasusedtocalculate theenvironmental qualification parameters including adiscussion ofheattransferbetweentheatmosphere inthewetwellandthesuppression pool.II.Assessment/Res onseAsexplained in4.4,allequipment locatedinthewetwellairspacewasqualified tothedrywelltemperature profile(T=340'F).Thisenvelopes anyconcernsrelatedtopoolthermalsrratification. maxIII.FutureActionReuiredNone Issue7.3Theanalysisassumesthatthewetwellairspaceisinthermalequilibrium withthesuppression pool.Intheshorttermthisisnon-conservative forMarkIIIduetoadiabatic compression effectsandfinitetimerequiredforheatandmasstobetransferred betweenthepoolandcontainment volumes.Footnote6:ThisissueasphrasedappliesonlytoaMarkIIIfacility. However,theconcerncanbegeneralized andappliedtotheearliercontainment types.ForMarkIandIIfacilities, indicatewhatmethodology wasusedtocalculate theenvironmental qualification parameters including adiscussion ofheattransferbetweentheatmosphere inthewetwellandthesuppression pool.II.Assessment/Res onseDuringpoolswellfollowing theDBALOCA,thewetwellairspaceisassumedtocompressadiabatically (NEDE-21544-P, GE,December, 1976).Thus,thewetwellairspaceandtemperature arerelatedvia1-y=constantForaninitial'wetwellairspacepressureandtemperature of14.8psiaand130'F,thetemperature atthetimeofmaximumwetwellcompression of56.1psia(SSESDARFigure4-39)canbedetermined tobe342'F.Thecompression anddecompression oftheairspacetakesplaceinapproximately 2sec.Duringthistimeperiodnoappreciable heattransfercanoccur,sincethefinalpressure(afterpoolfallback) is,muchlessthan56.1,whichreducesthepeaktemperature tolessthan342'F.Thus,,thiseventisnotincludedintheenvironmental qualification design.However,asdescribed intheresponseto4.4,allequipment wasqualified tothedrywellprofilewithapeaktemperature of340'F.II.FutureActionReuiredNone lpJ1E)II'L I.Issue8.Containment AirMassEffects8.1Thisissueisbasedonconsideration thatsomeTechnical Specifications allowoperation atparameter valuesthatdifferfromthevalues'sed inassumptions forFSARtransient analyses. Normallyanalysesaredoneassuminganominalcontainment pressureequaltoambient(0psig),atemperature nearmaximumoperation (90'F)anddonotlimitthedrywellpressureequaltothecontainment pressure. TheTechnical Specifications operation underconditions suchasapositivecontainment pressure(1.5psig),temperatures lessthanmaximum(60or70'F)anddrywellpressurecanbenegativewithrespecttothecontainment (-0.5psid).Allofthesedifferences wouldresultintransient responsedifferent thantheFSARdescriptions. II.Assessment/Res onseiForSSES,theTechnical Specifications limitthecontainment pressuretobetween-1.0and2.0psig.TheFSARanalysisassumed.aninitialwetwellanddrywellpressurebetween0.1and1.5psig(seeTable6.2-4).TheTechnical Specifications alsolimitthenormaloperating suppression pooltemperature toamaximumof90'F.TheFSARanalysisassumedaninitialpooltemperature of90'F(seeFSARFigure6.2-3).Inaddition, theTechnical Specifications limittheaveragedrywelltemperature toamaximumof135'F,whiletheFSARassumedadrywelltemperature between135'Fand150'F.Theanalysisalsoassumedaninitialwetwellairspacetemperature between90'Fand150'F.Theshort-term pressureresponsetoaDBALOCAdocumented inFSARSection6.2calculated amaximumdrywellpressureof44.2psig,comparedtoadesignpressureof53psig.Inaddition, thecontainment responseignoredtheheatabsorbedbythecontainment structures. Inconclusion, theTechnical Specifications limittheparameter valuesduringoperation tothoseassumedintheFSARtransient analysis. tIII.FutureActionReuiredNone lla~lpf4'Pullt I.Issuea8.2ThedraftGGNStechnical specifications permitoperation oftheplantwithcontainment pressurerangingbetween0and-2psig.Initiation ofcontainment sprayatapressureof-2psigmayreducethecontainment pressurebyanadditional 2psigwhichwouldleadtobucklingandfailuresinthecontainment linerplate.II.Assessment/Res onseFortheMarkIIIdesign,containment sprayinitiation occursautomatically onhighdrywellpressure. Withautomatic initiation, aspurioussignalcouldresultinaninadvertent sprayactuation. However,forSSES,thecontainment spraysmustbeinitiated bymanualaction.Inordertoinitiatethesprays,boththeinboardandoutboardisolation valvesmustbeopened.Theoperating procedures requirepermission fromtheShiftSupervisor toopenthevalves,andthe~kelockswitchplacedtoMANOVERRIDE. Basedontheabove,webelieveinadvertent sprayactuation duringnormaloperation requiresextraordinary circumstances beyondthedesignbasisoftheplant.Nevertheless, weevaluated theworst-case depressurization analysisfornon-accident conditions forSSESbasedontheminimumTechnical Specification initialpressureof13e7psia,andthemaximumTechnical Specification drywelltemperature of135'F.Thesevaluesminimized thepartialpressureofthenon-condensables andmaximized thevaporpressure. Ouranalysisrevealedthataninadvertent sprayactuation withtheseinitialconditions resultedinacontainment negativepressurewhichdoesnotexceedthecontainment negativedesignpressureof-5.0psig(reference FSARTable6.2-1).III.FutureActionReuiredNone-46-' 1'H I.Issue8.3Ifthecontainment ismaintained at-2psig,thetoprowofventscouldadmitblowdowntothesuppression poolduringanSBAwithoutaLOCAsignalbeingdeveloped. II.Assessment/Res onseTheNRCdispositioned thisconcernasN/AtoSSES.III.FutureActionReuired1None I.Issue8.4Describeallofthepossiblemethods,bothbeforeandafteranaccident, ofcreatingacondition oflowairmassinsidethecontainment. Discusstheeffectsonthecontainment designexternalpressureofactuating thecontainment sprays(pp.190-195of5/27/82transcript). II.Assessment/Res onseDuringnormaloperation, theonlywaytocreateacondition oflowairmassinthecontainment istoventthecontainment following asteamleak,poolheatuporlossofdrywellcoolingwhichincreases thecontainment temperature andvaporpressure. Asdescribed intheresponseto8.2,rapidcooldownoftheSSEScontainment duringnormaloperation willnotresultinthefinalcontainment pressureexceeding the-5.0psigdesignpressure. SincetheTechnical Specifications limitthemaximumpooltemperature to120'Fandthedrywelltemperature to135'F,conditions whichresultinalowercontainment airmassthantheaboveanalysiscouldnotexist.Furthermore, theresponseto8.2indicated thataninadvertent sprayactuateduringnormaloperation ishighlyunlikely. Following aLOCA,theStandbyGasTreatment System(SGTS)usedtoventthecontainment isolatesonhighdrywellpressure. Post-accident containment ventingwouldonlyoccurtorelievethecontainment pressureintheeventofimminentcontainment failure.Inaddition, FSARSubsection 6.2.1.1.4 documented theSSES-unique post-LOCA inadvertent sprayactuation (ISA)transient. Thisanalysisprovidedthebasisforthenumberandflowcapacityofourdrywell-to-wetwellVBstolimitthecontainment pressureresponsetolessthanthe-5.0psigdesignpressure. Theanalysisassumedallthenon-condensables inthedrywellwerepurgedintothewetwellairspace, withsteamonlyinthedrywell.Ourreviewofthepost-LOCA ISAanalysisindicated thataninitialpressureof0.1psig(seeFSARTable6.2-23)wasassumed,whiletheTechnical Specifications allowacontainment pressureequalto-1.0psig.However,were-analyzed thepost-LOCA ISAanalysiswithaninitialpressureequalto-1.0psig,anddetermined thenegativepressuretransient doesnotexceedthe-5.0psigdesignpressure. Inaddition, theBWROG'sEPGprogramaddresses thecriteriaforoperatoractionstopreventexceeding thecontainment negativedesignpressureforabnormalplantconditions outsidetheTechnical Specification limits.Theseguidelines arecontained inRevision2oftheEPGs.III.FutureActionReuiredNone Et,tr~,f I.Issue9.FinalDrellAirMass9.1ThecurrentFSARanalysisisbaseduponcontinuous injection ofrelatively coolECCSwaterintothedrywellthroughabrokenpipefollowing adesignbasisaccident. SincetheoperatorisdirectedtothrottleECCSoperation tomaintainthereactorvesselwaterleveltoaboutthelevelofthesteamlines,thebreakwillbereleasing saturated steaminsteadofreleasing relatively coolECCSwater.Therefore, thedrywellairwhichwouldhavebeenpurgedandthendrawnbackintothedrywellwillremaininthewetwell,andhigherpressures thananticipated willresultinboththewetwellandthedrywell.II.Assessment/Res onseAspreviously discussed in4.4,theshort-term pressureresponsetoaDBALOCAcontrolsthemaximumcontainment

pressure, asopposedtoaMarkIIIcontainment design,wherethelong-term pressureresponseyieldsthemaximumpressure.

Therefore, anyECCSthrottling whichpreventsvacuumbreakeractuation willhavenoeffectontheshort-term pressure~~response. III.FutureActionReuiredNone (JP I.Issue9.2Thecontinuous steamingproducedbythrottling theECCSflowwillcauseincreased directleakagefromthedrywelltothecontainment. Thiscouldresultinincreased containment pressure. II.Assessment/Res onseTheSSES-unique steambypasscalculation described intheresponseto5.1assumedacontinuous steamsupplyfromthedrywell,atadrywell-to-wetwellAPequaltothedowncomer submergence fortheentiretransient. Therefore, thesteambypassanalysisaccountsforanyincreased directleakage'rom thedrywell-to-wetwell causedbythrottling theECCSflow.Inaddition, theanalysisshowedthatoncetheoperatorinitiates containment spray,thepressureincreaseterminates. Theresponses to4.8and4.9documented thatnoadverseeffectsontheSSEScontainment designoccurduringoperation ofthecontainment sprays.III.FutureActionReuiredNone I.Issue9.3Itappearsthatsomeconfusion existsastowhetherSBAsandstuckopenSRVaccidents aretreatedastransients ordesignbasisaccidents. Clarifyhowtheyaretreatedandindicatewhethertheinitialconditions weresetatnominalorlicensing values(pp.202-205of5/27/82transcript). II.Assessment/Res onsehAppendixIoftheSSESDARdocumented theSBAandstuckopenreliefvalvetransients. Theassumptions usedinthesub)ectanalysisweredeveloped withintheMarkIIOwners'roup andconformtotherequirements ofdraftNUREG-0783. Supplement No.1oftheSSESSafetyEvaluation Reportdocumented yourreviewandacceptance oftheanalysis. III.FutureActionReuiredNone lH<ic(1I'l4iS I.Issue10.1and10.2II.Assessment/Res onseTheNRCdispositioned theseconcernsasN/AtoSSES.III.FutureActionReuired'one I.Issue,11.0erational ControlofDrelltoContainment Differential Pressures MarkIIIloaddefinitions arebaseduponthelevelsinthesuppression poolandthedrywellweirannulusbeingthesame.TheGGNStechnical specifications permitelevation differences betweenthesepools.Thismayaffectloaddefinition forventclearing. Footnote8:ForMarkIandIIfacilities, considerthewaterinthedowncomers. II.Assessment/Res onseThewatergetloadsoccurring duringthewaterclearingphaseofthepoolswellphenomenon areobtainedusingthemaximumwaterclearingvelocity. Thepermissible difference inwaterelevation from'thenominalvalueinthesuppression poolandthedowncomers are+1ft(VBsetpointequalto0.5psid).Thiselevation difference generates asmalldifference inbackpressure, whichhasbeenshowntohavenegligible effectoneitherventclearingorpoolswellloads.III.FutureActionReuiredNone II(lJ I.Issue12513II.Assessment/Res onseTheNRCdispositioned theseconcernsasN/AforSSES.III.FutureActionReuiredNone AI I.Issue14.RHRBackflowThrouhContainment SraAfailureinthecheckv'alveintheLPCIlinetothereactorvesselcouldresultindirectleakagefrom'thepressurevesseltothecontainment atmosphere. ThisleakagemightoccurastheLPCImotor-operated isolation valveisclosingandthemotor-operated isolation valveinthecontainment spraylineisopening.Thiscouldproduceunanticipated increases inthecontainment spray.II.Assessment/Res onseOperation ofthedrywellspraysisnotautomatic andrequiresoperatoractiontoinitiate. TheRHRoperating procedure requirestheLPCIinjection valvetothevesseltobeclosedandpermission fromtheShiftSupervisor priortoopeningthetwoisolation valvestothedrywellsprays.Inaddition, theLPCIinjection valvesareinterlocked suchthattheywillnotopenuntilthereactorpressuredecreases below430psig.Atthislowreactorpressure, noappreciable flowfromthereactortothespraysviathefailedcheckvalvecouldoccurunlesstheRHRpumptripped.Thus,operatorerrorandtwosinglefailures(failedcheckvalveandpumptrip)arerequiredtoestablish flowfromthevesseltothesprayheader.ThisscenarioexceedsthedesignbasisoftheSSESplant.III.FutureActionReuiredNone i,pIII'4,I~ I.Issue15.SecondarContainment VacuumBreakerPlenumResonseTheSTRIDEplantshad.vacuumbreakersbetweenthecontainment andthesecondary containment. Withsufficiently highflowsthroughthevacuumbreakerstocontainment, vacuumcouldbecreatedinthesecondary containment. II.Assessment/Res onseForSSES,therearenoVBsbetweentheprimarycontainment andsecondary containment. III.FutureActionReuiredNone i~a~~,~i0'4 I.Issue16.EffectofSuressionPoolLevelonTemeratureMeasurement Someofthesuppression pooltemperatures sensorsarelocated(byGErecommendation) 3into12inbelowthepoolsurfacetoprovideearlywarningofhighpooltemperature. However,ifthesuppression poolisdrawndownbelowthelevelofthetemperature sensors,theoperatorcouldbemisledbyerroneous readingsandrequiredsafety,actioncouldbedelayed.II.Assessment/Res onseTheSSESSuppression PoolTemperature Monitoring System(SPOTMOS) has16sensorsat8locations (2perdivision) atEl.20ft.Inaddition, 4moresensorsarelocatedatEl.3.5ft(T-quencher elevation). Thecontrolroompaneldisplaystheaverageofthe8uppersensors;butthepooltemperatures fromthe4lowersensorscanbedisplayed, ifrequired. TheTechnical Specifications requireasuppression poollevelbetween22and24ft.AnalarmsoundsinthecontrolroomifthepoolleveldropstoEl.22.25'.Emergency operating procedure E0-00-23, "Containment Control," instructs theoperatortorestorethesuppression poolleveltobetween22and24ftpertheTechnical Specifications. TheMassandEnergyanalysis(seeAppendixIoftheDAR)requirestheoperatortoscramthereactoratapooltemperature of110'Fanddepressurize thereactoratapooltemperature of120'F.Thesescenarios (i.e.,isolation/scram, stuckopenreliefvalveandsmallbreakaccident) resultinanincrease, notadecrease, inpoollevelduetocombinations offeedwater, HPCI,RCICandroddriveflowfromthecondensate storagetank.Largebreaks,ontheotherhand,coulddecreasethelevelinsuppression pool.However,ifthebreakoccurredattheTechnical Specifications minimumlevelof22ft,amaximumdecreaseinpoollevelof1.5ftcorresponding tothe1.5fttallventrisersinthedrywellwouldstillresultinsubmerged uppersensors.Depressurizing thereactorviathealternate modeofshutdowncoolingcouldreducethesuppression poolleveltobelowtheupper16sensors.Again,theoperatorisinstructed torestorethesuppression poollevelviathecondensate storagetank.Iflevelcannotberestored, the4lowersensorsandthetemperature sensoratthesuctiontotheRHRheatexchangers couldbeusedtomonitorthesuppression pooltemperature. III.FutureActionReuiredNone Jr I.Issue17.EmerencProcedure Guidelines TheEPGscontainacurvewhichspecifies limitations onsuppression poollevelandreactorpressurevesselpressure. Thecurvepresently doesnotadequately accountforupperpooldump.Atpresent,theoperatorwouldberequiredtoinitiateautomatic depressurization whentheonlyactionrequiredistheopeningofoneadditional SRV.II.Assessment/Res onseSSESTechnical Specifications requirethatthepoollevelbemaintained within'thenormaloperating limi'ts'(22to24ft).Iftheycannotberestoredwithin1hour,thentheoperatorisrequiredtobeinhotshutdownwithinthenext12hoursandincoldshutdownwithinthefollowing 24hours.Inaddition, emergency procedure.E0-00-023, "Containment Control," directstheoperatortomaintainthereactorpressureandpoollevelbelowtheSuppression PoolLoadLimit(seefigurenextpage),ifthelevelexceeds24'.Thiscanbeaccomplished bymanuallyactuating oneormoreSRV,however,ifthelevelandpressurecannotbemaintained belowthecurve,thentheoperatorisinstructed toinitiateADS.III.FutureActionReuiredNone 4Attachment FEO-00-023 Revision1Page15of18SUPPRESSION POOLLOADLIMITI~'IijII!I~)i~s~>hh~~I)II!!Ir)!I'!(IIRIa.~lIi'.!IIIIiIII'.I!II)~II'.I)III',):I!)iIIII!III}!.iiII;)iI)IIiIIii:!I!)I1}!!!)!!~1IIIIIIIjIIIi.'!IIIIIII!I')IyIIIIII'!)I~IIl!IIII')!II~I~)IjjII!I)I~!~'~jiIis~!I~I~)I~:!II~~'I,0-';'I;200;-,400,.j,I600.,": 800,.1000;1'200,,1400.IIIPVPressure(ps20-.I"I!II)~j)Page1of1

I.Issue18.EffectsofInsulation Debris18.1Failuresofreflective insulation inthedrywellmayleadtoblockageofthegratingsabovetheweirannulus.Thismayincreasethepressurerequiredinthedrywelltoclearthefirstrowofdrywellventsandperturbtheexistingloaddefinitions. Footnote10:ThisissueasphrasedappliedonlytoaMarkIIIfacility. However,theconcerncanbegeneralized. Accordingly, discusshowtheeffectsofinsulation debriscouldperturbexistingloaddefinitions orcouldblocksuctionstrainers. Inresponding tothisissue,youmayrefertoexistinggenericstudies,e.g.,thestudydonefortheCooperfacility. II.Assessment/Res onseForSSES,thepeakdownwardpressureonthediaphragm slaboccursduringventclearingatapproximately 1secafterthebreak.Thisisinsufficient timeforanyinsulation debristotransittoandblockthedowncomers. Subsequent totheinitialpressurization, anyminorblockagethatmightoccurwouldhaveaninsignificant effectonpoolswellandthepeakdrywellpressure(seeresponsetoIssue18.2fordescription oftheinsulation). III.FutureActionReuiredNone CI I.Issue18.2Insulation debrismaybetransported throughtheventsinthedrywellwallintothesuppression pool.Thisdebriscouldthencause,blockageofthesuctionstrainers. ',Footnote10:ThisissueasphrasedappliesonlytoaMarkIIIfacility. However,theconcerncanbegeneralized. Accordingly, discusshowtheeffectsofinsulation debriscouldperturbexistingloaddefinitions orcouldblocksuctionstrainers. Inresponding tothisissue,youmayrefertoexistinggenericstudies;e.g.,thestudydonefortheCooperfacility. II.Assessment/Res onseThisissueisdiscussed inFSARSection6.2.2.3(inresponsetoNRCQuestion021.20)andissummarized asfollows:Theinsulation usedwithinthecontainment istheallmetal,reflective type.Theinsulation consistsoflargeassemblies heldinplacebystainless steellatches.Thelatchesareequippedwithpositivelockingdevices.Itwouldbeunlikelythattherelatively largerpiecesofmetallicinsulation wouldpassthroughthesmallopeningsatthetopofthe87downcomers. Theseopeningsaremadesmallerbythepresenceofjetdeflectors asshowninFSARFigure6.2-56.,Verylittle,ifany,oftheinsulation wouldfinditswayintothesuppression pool.Thesuctionstrainers oftheECCSpumpsaredesignedtosustain50%cloggingwithoutaffecting systemperformance. InadditiontotheFSARdiscussion above,itshouldbenotedthatthesuctionstrainers arelocatedmidwayupthesuppression poolwall.Sinceanymetallicinsulation enteringthepoolwilleitherfloatorsink,thelikelihood ofanystrainercloggingisextremely remote.III.FutureActionReuiredNone 0 I.Issue21.Containment MakeuAirForBackuPureRegulatory Guide1.7requiresabackuppurgeH2removalcapability. Thisbackup~purgeforMarkIIIisviathedrywellpurgelinewhichdischarges totheshieldannuluswhichinturnisexhausted throughthestandbygastreatment system(SGTS).Thecontainment airisblownintothedrywellviathedrywellpurgecompressor toprovideapositivepurge.Thecompressors drawfromthecontainment; however,withouthydrogenleanairmakeuptothecontainment, noreduction incontainment hydrogenconcentration occurs.Itisnecessary toassurethattheshieldannulusvolumecontainsahydrogenleanmixtureofairtobeadmittedtothecontainment viacontainment vacuumbreakers. ForMarkIandIIfacilities, discussthepossibility ofpurgeexhaustbeingmixedwiththeintakeairwhich,replenishes thecontainment airmass.Assessment/Res onse(IntheSSESdesignthepurgeexhauststhroughtheSGTSsystemandexitsonthewestsideofthereactorbuildingroof(El.872').Thesupplyintakeislocatedontheeastsideofthereactorbuildingatapproximately El.790',andthereactorbuildingis160'ide.Basedonthisseparation, exhaustairshouldnotmixwithintakeair.III.FutureActionReuiredNone 4I4tP)Il'H I.Issue22.Miscellaneous EmerencProcedure Guideline ConcernsTheEPGscurrently inexistence havebeenpreparedwiththeintentofcopingwithdegradedcoreaccidents. Theymaycontainrequirements conflicting withdesignbasisaccidentconditions. Someoneneedstocarefully reviewtheEPGstoassurethattheydonotconflictwiththeexpectedcauseofthedesignbasicaccident. II.Assessment/Res onse-TheSSESEmergency Operating Procedures havebeendeveloped inaccordance withtheBWROwners'roup EPGs.Assuch,theseguidelines underwent arigorousreviewwithinGEand,theOwners'roup. Thisprocessassuredthepreparation ofEPGswhichwillrespondto,andmitigate, anyscenarios whichresultindegradedplantconditions. III.FutureActionReuiredNonePF:sahF-9 %1PlN0}}

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1.0INTRODUCTION

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5.0CONCLUSION

6.0REFERENCES

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ML18031A407: Difference between revisions

Revision as of 04:19, 29 June 2018

Text

1.0INTRODUCTION

5.0CONCLUSION

1.0INTRODUCTION

5.0CONCLUSION

6.0REFERENCES

References:

DearMr.Shovlin:

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