ML17254A294: Difference between revisions

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=Text=
=Text=
{{#Wiki_filter:REGULATORYFORMATIONDISTRIBUTIONSM(RIDS)
{{#Wiki_filter:REGULATORY FORMATION DISTRIBUTION SM(RIDS)


==SUBJECT:==
==SUBJECT:==
RespondstoNRCr'equestforreviewofcertainconcernsreExxonnuclearCor'pECCSevaluationmodelsBasedonlistedrevieww/Exxon8'riestinghouse<statedconcernsinapplicabletofacility,SIZE:DISTRIBUTIONCODE+A001DCOPIESRECEIVED:LTRENCLTITLE:ORSubmittal:GeneralDistributionACCESSIONNBR;8504030076DOC~DATE:85/03/26NOTARIZED;NODOCKETFACIL:50244RobertEmmetGinnaNuclearPlantgUnitiiRochesterG05000244AUTHINANE'UTHORAFFILIATIONKOBERgR,HERochesterGas8ElectricCorp.RECIP~NAME>>RECIPIENTAFFILIATIONZNOLINSKI'iJ.AOperatingReactorsBranch5NOTES;NRR/DL/SEP1cy,OL:09/19/6905000244RECIPIENTIDCODE/NAME'RRORB5BC01INTERNAL:ACRS'9ELD/HDS4NRR/DLDIRNRR/DL/TSRG.NRR/DSI/RABRGN1COPIESLTTRENCL7611111RECIPIENTIDCODE/NAMEADM/LFMBNRR/DE/MTEBNRR/Dl/ORABETBREFILE04COPIESLTTRENCLEXTERNAL:EGSGBRUSKE,SNRCPDR02NOTES:LPDRNSIC0305TOTALNUMBEROFCOPIESREQUIRED:LTTR28ENCL H(IIIII~~'Ilg''llI'Pt~
RespondstoNRCr'equestforreviewofcertainconcernsreExxonnuclearCor'pECCSevaluation modelsBasedonlistedrevieww/Exxon8'riestinghouse<stated concernsinapplicable tofacility, SIZE:DISTRIBUTION CODE+A001DCOPIESRECEIVED:LTR ENCLTITLE:ORSubmittal:
t///////////////////////////II/El)7/IIII//////8'vis//ROCHESTERGASANDIstAtCELECTRICCORPORATIONo69EASTAVENUE,ROCHESTER,N.Y.14649-0001ROGERtN.KOBERVICePRESIDSNTELECTRIC6STEAMPttODVCTIONMarch26>1985TSI.CPHONCARCACODETld546-2700DirectorofNuclearReactorRegulationAttention:Mr.JohnA.Zwolinski>ChiefOperatingReactorsBranchNo.5U.S.NuclearRegulatoryCommissionWashington<D.C.20555
GeneralDistribution ACCESSION NBR;8504030076 DOC~DATE:85/03/26NOTARIZED; NODOCKETFACIL:50244RobertEmmetGinnaNuclearPlantgUnitiiRochester G05000244AUTHINANE'UTHOR AFFILIATION KOBERgR,HE Rochester Gas8ElectricCorp.RECIP~NAME>>RECIPIENT AFFILIATION ZNOLINSKI'i J.AOperatingReactorsBranch5NOTES;NRR/DL/SEP 1cy,OL:09/19/6905000244RECIPIENT IDCODE/NAME'RR ORB5BC01INTERNAL:
ACRS'9ELD/HDS4NRR/DLDIRNRR/DL/TSRG
.NRR/DSI/RAB RGN1COPIESLTTRENCL7611111RECIPIENT IDCODE/NAME ADM/LFMBNRR/DE/MTEB NRR/Dl/ORABETBREFILE04COPIESLTTRENCLEXTERNAL:
EGSGBRUSKE,SNRCPDR02NOTES:LPDRNSIC0305TOTALNUMBEROFCOPIESREQUIRED:
LTTR28ENCL H(IIIII~~'Ilg''llI'Pt~
t//////////////
/////////////
II/El)7/IIII
//////8'vis//ROCHESTER GASANDIstAtCELECTRICCORPORATION o69EASTAVENUE,ROCHESTER, N.Y.14649-0001 ROGERtN.KOBERVICePRESIDSNT ELECTRIC6STEAMPttODVCTION March26>1985TSI.CPHONC ARCACODETld546-2700DirectorofNuclearReactorRegulation Attention:
Mr.JohnA.Zwolinski>
ChiefOperating ReactorsBranchNo.5U.S.NuclearRegulatory Commission Washington<
D.C.20555


==Subject:==
==Subject:==
Line 26: Line 37:


==DearMr.Zwolinski:==
==DearMr.Zwolinski:==
ThisletterisinresponsetoarequestfrommembersoftheNRCstafftoaddresscertainconcernsregardingExxonNuclearCorporation's(ENC)emergencycorecoolingsystemevaluationmodel.WehavereviewedtheseconcernswithExxonNuclearandwithourcurrentfuelvendorandcoredesignerWestinghouseElectricCorporationand>asdescribedbelow<havereachedtheconclusionthatthestatedconcernsarenotapplicabletoGinnaFrom1978through1983>GinnareloadfuelwassuppliedbyENC.ThemostrecentENClossofcoolantaccidentanalysisforGinnawasperformedinSpring1982andwassubmittedtotheNRCwithourletterdatedAugust9<1982.Thatanalysisresultedinacalculatedpeakcladtemperature(PCT)of1928F.ENChasconfirmedtousthatthespecificmodelsusedfortheGinnaanalysisdidnotcontainanyofthethreeerrorswhichtheNRCStaffhasidentifiedtousregardingheattransfercorrelationsandaugmentationfactorsandmixingassumptions.RegardingthefourthconcernraisedbytheNRCStaff>thefollowingbackgroundinformationandconclusionsareprovided.In1984<RG6EbeganatransitiontoWestinghousefuel.IntheanalysisperformedbyWestinghouseforthattransition<theyevaluatedtheplantresponsetoalltransientswhichmaybeaffectedbyfueltype>includingthelossofcoolantaccident.Westinghousewasprovidedwithdetailedfuelparameterssuchasdimensions>densitiesandenrichments.WestinghouseperformeddetailedpressuredropmeasurementsonWestinghouseoptimizedfuelassembly(OFA)designfuelandENCfuelassemblies.WestinghouseconcludedthatanalyzingacompletecoreofOFAunderLOCAconditionswasconservativewithrespecttoanypotentialcombinationandconfigurationofWestinghouseandENCassemblytypes.TheassumptionofmodelingafullcoreofOFAwasdeterminedtobeconservativefortransitioncyclesfortwomajorreasons:8504OSOO7S850S2SlPDRADOCK05000244PPDRADO),)O ROCHESTERGASANDELECTRICCORP.DATEMarch26>1985TOMr.JohnA.ZwolinskiSHEETNO.2TheincreaseincoreflowareaassociatedwithOFAduetothesmallerroddiameterhasanimportantimpactonfloodingratesduringreflood.AfullOFAcoreconfigurationdecreasescorefloodingrateswhichreducesheattransfercoefficientsandresultsinearliersteamcooling.2.TheOFAhasahighervolumetricheatgenerationratethantheENCfuel.Theanalysisassumestha'tanOFAassemblyhasthehottestrodandmaximumFHwhichmaximizesthecalculatedPCT.Westinghousealsoevaluatedtheimpactofanyhydraulicresistancedifference.TheonlyportionoftheLOCAevaluationmodelimpactedbythesmallhydraulicresistancedifferencewhichexistsbetweentheENCandOFAfuelisthecorerefloodtransient.Sincethehydraulicmismatchissosmall>onlycrossflowsduetosmallerrodsizeandgriddesignsneedtobeevaluated.ThemaximumrefloodaxialflowreductionfortheOFAatanypossiblepeakcladtemperaturelocationinthecore<resultingfromcrossflowstoadjacentENCassemblies<hasbeenconservativelycalculatedtobeonepercent.AnalyseswereperformedwhichdemonstratedthatthemaximumPCTpenaltypossibleofOFAfuelduringthetransitionperiodis4F.Afterthistransition>the0WestinghouseECCSanalysiswillapplytoafull-coreOFAwithoutthecrossflowpenalty.Inadditiontothefactorsidentifiedabove<theburnuplevelsand/orpowerlevelsoftheENCfuelfurtherassurethatthelimitingfuelistheOFAfuel.ThelastregionofENCfuelwasloadedin1983.Fourofthesefuelassemblieshaveburnupsofatleast11,000MWD/MTU<whiletheotherassembliesinthisregionhaveburnuplevelsinexcessof20>000MWD/MTU.EightfreshENCfuelassemblieswereloadedduringtheSpring1984refuelingout-ageandcurrentlyhaveburnupsinexcessofll>000MWD/MTU.Maxi-mumburnupswillremainbelowthedesignlimitsestablishedbyENC.TheENCassembliesarenotlocatedinpeakpowerlocationsforCycle15buthaveFvaluesatleast5%belowthatinthelimitingOFAlocations.TheminimummargintotheFlimitpre-0dietedforanENCassemblyoccursatanelevationwheretheFlimitis2.29andthepredictedFis2.125.Itshouldben8tedthatthisvalueispredictedb2sedonloadfollowoperation<whileGinnatypicallyoperatesbaseloaded.AsdescribedinourletterdatedApril10<1984<wehaveloadedfourENCannularfuelpelletdemonstrationassembliesduringthecurrentCycle14-15refuelingoutage.Inadditiontothefueltemperatureandstoredenergybenefitswhichderivefromtheuseofanannularfuelpellet,theseassembliesareloadedinthecoreperipheryandhaveassemblypowerlevelslessthan0.8timescoreaveragepower.TheseassemblieshavebeenexplicitlymodeledinthemostrecentWestinghousereloadanalysis.Thus>theseassembliesalsoareboundedbytheOFAfuelanalysis.
 
ROCHESTERGASANPELECTRICCORP.pATENarch26,l985ToNr.JohnA.zwolinskiSHEETNO.ForthereasonsstatedaboveiwehaveconcludedthattheanalysesperformedbyWestinghousewiththeapprovedWestinghouseevaluationmodelsboundallfuelcurrentlyloadedintheGinnareactor.ThisevaluationdemonstratesthatthelimitingfueltypeistheWestinghouseOFAfuel.Thus<norelianceiscurrentlymadebytheENCLOCAmodelsandpotentialconcernsregardingthosecodesdonotapplytoGinna.ytrulyyoursiRogerW.Kober}}
ThisletterisinresponsetoarequestfrommembersoftheNRCstafftoaddresscertainconcernsregarding ExxonNuclearCorporation's (ENC)emergency corecoolingsystemevaluation model.WehavereviewedtheseconcernswithExxonNuclearandwithourcurrentfuelvendorandcoredesignerWestinghouse ElectricCorporation and>asdescribed below<havereachedtheconclusion thatthestatedconcernsarenotapplicable toGinnaFrom1978through1983>GinnareloadfuelwassuppliedbyENC.ThemostrecentENClossofcoolantaccidentanalysisforGinnawasperformed inSpring1982andwassubmitted totheNRCwithourletterdatedAugust9<1982.Thatanalysisresultedinacalculated peakcladtemperature (PCT)of1928F.ENChasconfirmed tousthatthespecificmodelsusedfortheGinnaanalysisdidnotcontainanyofthethreeerrorswhichtheNRCStaffhasidentified tousregarding heattransfercorrelations andaugmentation factorsandmixingassumptions.
Regarding thefourthconcernraisedbytheNRCStaff>thefollowing background information andconclusions areprovided.
In1984<RG6Ebeganatransition toWestinghouse fuel.Intheanalysisperformed byWestinghouse forthattransition<
theyevaluated theplantresponsetoalltransients whichmaybeaffectedbyfueltype>including thelossofcoolantaccident.
Westinghouse wasprovidedwithdetailedfuelparameters suchasdimensions>
densities andenrichments.
Westinghouse performed detailedpressuredropmeasurements onWestinghouse optimized fuelassembly(OFA)designfuelandENCfuelassemblies.
Westinghouse concluded thatanalyzing acompletecoreofOFAunderLOCAconditions wasconservative withrespecttoanypotential combination andconfiguration ofWestinghouse andENCassemblytypes.Theassumption ofmodelingafullcoreofOFAwasdetermined tobeconservative fortransition cyclesfortwomajorreasons:8504OSOO7S 850S2SlPDRADOCK05000244PPDRADO),)O ROCHESTER GASANDELECTRICCORP.DATEMarch26>1985TOMr.JohnA.Zwolinski SHEETNO.2Theincreaseincoreflowareaassociated withOFAduetothesmallerroddiameterhasanimportant impactonfloodingratesduringreflood.AfullOFAcoreconfiguration decreases corefloodingrateswhichreducesheattransfercoefficients andresultsinearliersteamcooling.2.TheOFAhasahighervolumetric heatgeneration ratethantheENCfuel.Theanalysisassumestha'tanOFAassemblyhasthehottestrodandmaximumFHwhichmaximizes thecalculated PCT.Westinghouse alsoevaluated theimpactofanyhydraulic resistance difference.
TheonlyportionoftheLOCAevaluation modelimpactedbythesmallhydraulic resistance difference whichexistsbetweentheENCandOFAfuelisthecorerefloodtransient.
Sincethehydraulic mismatchissosmall>onlycrossflows duetosmallerrodsizeandgriddesignsneedtobeevaluated.
Themaximumrefloodaxialflowreduction fortheOFAatanypossiblepeakcladtemperature locationinthecore<resulting fromcrossflows toadjacentENCassemblies<
hasbeenconservatively calculated tobeonepercent.Analyseswereperformed whichdemonstrated thatthemaximumPCTpenaltypossibleofOFAfuelduringthetransition periodis4F.Afterthistransition>
the0Westinghouse ECCSanalysiswillapplytoafull-core OFAwithoutthecrossflowpenalty.Inadditiontothefactorsidentified above<theburnuplevelsand/orpowerlevelsoftheENCfuelfurtherassurethatthelimitingfuelistheOFAfuel.ThelastregionofENCfuelwasloadedin1983.Fourofthesefuelassemblies haveburnupsofatleast11,000MWD/MTU<whiletheotherassemblies inthisregionhaveburnuplevelsinexcessof20>000MWD/MTU.EightfreshENCfuelassemblies wereloadedduringtheSpring1984refueling out-ageandcurrently haveburnupsinexcessofll>000MWD/MTU.Maxi-mumburnupswillremainbelowthedesignlimitsestablished byENC.TheENCassemblies arenotlocatedinpeakpowerlocations forCycle15buthaveFvaluesatleast5%belowthatinthelimitingOFAlocations.
TheminimummargintotheFlimitpre-0dietedforanENCassemblyoccursatanelevation wheretheFlimitis2.29andthepredicted Fis2.125.Itshouldben8tedthatthisvalueispredicted b2sedonloadfollowoperation<
whileGinnatypically operatesbaseloaded.Asdescribed inourletterdatedApril10<1984<wehaveloadedfourENCannularfuelpelletdemonstration assemblies duringthecurrentCycle14-15refueling outage.Inadditiontothefueltemperature andstoredenergybenefitswhichderivefromtheuseofanannularfuelpellet,theseassemblies areloadedinthecoreperiphery andhaveassemblypowerlevelslessthan0.8timescoreaveragepower.Theseassemblies havebeenexplicitly modeledinthemostrecentWestinghouse reloadanalysis.
Thus>theseassemblies alsoareboundedbytheOFAfuelanalysis.
ROCHESTER GASANPELECTRICCORP.pATENarch26,l985ToNr.JohnA.zwolinski SHEETNO.Forthereasonsstatedaboveiwehaveconcluded thattheanalysesperformed byWestinghouse withtheapprovedWestinghouse evaluation modelsboundallfuelcurrently loadedintheGinnareactor.Thisevaluation demonstrates thatthelimitingfueltypeistheWestinghouse OFAfuel.Thus<norelianceiscurrently madebytheENCLOCAmodelsandpotential concernsregarding thosecodesdonotapplytoGinna.ytrulyyoursiRogerW.Kober}}

Revision as of 13:06, 29 June 2018

Responds to NRC Request for Review of Certain Concerns Re Exxon Nuclear Corp ECCS Evaluation Model.Based on Listed Review W/Exxon & Westinghouse,Stated Concerns Inapplicable to Facility
ML17254A294
Person / Time
Site: Ginna 
Issue date: 03/26/1985
From: KOBER R W
ROCHESTER GAS & ELECTRIC CORP.
To: ZWOLINSKI J A
Office of Nuclear Reactor Regulation
References
NUDOCS 8504030076
Download: ML17254A294 (5)
v • d • e


Text

REGULATORY FORMATION DISTRIBUTION SM(RIDS)

SUBJECT:

RespondstoNRCr'equestforreviewofcertainconcernsreExxonnuclearCor'pECCSevaluation modelsBasedonlistedrevieww/Exxon8'riestinghouse<stated concernsinapplicable tofacility, SIZE:DISTRIBUTION CODE+A001DCOPIESRECEIVED:LTR ENCLTITLE:ORSubmittal:

GeneralDistribution ACCESSION NBR;8504030076 DOC~DATE:85/03/26NOTARIZED; NODOCKETFACIL:50244RobertEmmetGinnaNuclearPlantgUnitiiRochester G05000244AUTHINANE'UTHOR AFFILIATION KOBERgR,HE Rochester Gas8ElectricCorp.RECIP~NAME>>RECIPIENT AFFILIATION ZNOLINSKI'i J.AOperatingReactorsBranch5NOTES;NRR/DL/SEP 1cy,OL:09/19/6905000244RECIPIENT IDCODE/NAME'RR ORB5BC01INTERNAL:

ACRS'9ELD/HDS4NRR/DLDIRNRR/DL/TSRG

.NRR/DSI/RAB RGN1COPIESLTTRENCL7611111RECIPIENT IDCODE/NAME ADM/LFMBNRR/DE/MTEB NRR/Dl/ORABETBREFILE04COPIESLTTRENCLEXTERNAL:

EGSGBRUSKE,SNRCPDR02NOTES:LPDRNSIC0305TOTALNUMBEROFCOPIESREQUIRED:

LTTR28ENCL H(IIIII~~'IlgllI'Pt~

t//////////////

/////////////

II/El)7/IIII

//////8'vis//ROCHESTER GASANDIstAtCELECTRICCORPORATION o69EASTAVENUE,ROCHESTER, N.Y.14649-0001 ROGERtN.KOBERVICePRESIDSNT ELECTRIC6STEAMPttODVCTION March26>1985TSI.CPHONC ARCACODETld546-2700DirectorofNuclearReactorRegulation Attention:

Mr.JohnA.Zwolinski>

ChiefOperating ReactorsBranchNo.5U.S.NuclearRegulatory Commission Washington<

D.C.20555

Subject:

LossofCoolantAccidentAnalysisR.E.GinnaNuclearPowerPlantDocketNo.50-244

DearMr.Zwolinski:

ThisletterisinresponsetoarequestfrommembersoftheNRCstafftoaddresscertainconcernsregarding ExxonNuclearCorporation's (ENC)emergency corecoolingsystemevaluation model.WehavereviewedtheseconcernswithExxonNuclearandwithourcurrentfuelvendorandcoredesignerWestinghouse ElectricCorporation and>asdescribed below<havereachedtheconclusion thatthestatedconcernsarenotapplicable toGinnaFrom1978through1983>GinnareloadfuelwassuppliedbyENC.ThemostrecentENClossofcoolantaccidentanalysisforGinnawasperformed inSpring1982andwassubmitted totheNRCwithourletterdatedAugust9<1982.Thatanalysisresultedinacalculated peakcladtemperature (PCT)of1928F.ENChasconfirmed tousthatthespecificmodelsusedfortheGinnaanalysisdidnotcontainanyofthethreeerrorswhichtheNRCStaffhasidentified tousregarding heattransfercorrelations andaugmentation factorsandmixingassumptions.

Regarding thefourthconcernraisedbytheNRCStaff>thefollowing background information andconclusions areprovided.

In1984<RG6Ebeganatransition toWestinghouse fuel.Intheanalysisperformed byWestinghouse forthattransition<

theyevaluated theplantresponsetoalltransients whichmaybeaffectedbyfueltype>including thelossofcoolantaccident.

Westinghouse wasprovidedwithdetailedfuelparameters suchasdimensions>

densities andenrichments.

Westinghouse performed detailedpressuredropmeasurements onWestinghouse optimized fuelassembly(OFA)designfuelandENCfuelassemblies.

Westinghouse concluded thatanalyzing acompletecoreofOFAunderLOCAconditions wasconservative withrespecttoanypotential combination andconfiguration ofWestinghouse andENCassemblytypes.Theassumption ofmodelingafullcoreofOFAwasdetermined tobeconservative fortransition cyclesfortwomajorreasons:8504OSOO7S 850S2SlPDRADOCK05000244PPDRADO),)O ROCHESTER GASANDELECTRICCORP.DATEMarch26>1985TOMr.JohnA.Zwolinski SHEETNO.2Theincreaseincoreflowareaassociated withOFAduetothesmallerroddiameterhasanimportant impactonfloodingratesduringreflood.AfullOFAcoreconfiguration decreases corefloodingrateswhichreducesheattransfercoefficients andresultsinearliersteamcooling.2.TheOFAhasahighervolumetric heatgeneration ratethantheENCfuel.Theanalysisassumestha'tanOFAassemblyhasthehottestrodandmaximumFHwhichmaximizes thecalculated PCT.Westinghouse alsoevaluated theimpactofanyhydraulic resistance difference.

TheonlyportionoftheLOCAevaluation modelimpactedbythesmallhydraulic resistance difference whichexistsbetweentheENCandOFAfuelisthecorerefloodtransient.

Sincethehydraulic mismatchissosmall>onlycrossflows duetosmallerrodsizeandgriddesignsneedtobeevaluated.

Themaximumrefloodaxialflowreduction fortheOFAatanypossiblepeakcladtemperature locationinthecore<resulting fromcrossflows toadjacentENCassemblies<

hasbeenconservatively calculated tobeonepercent.Analyseswereperformed whichdemonstrated thatthemaximumPCTpenaltypossibleofOFAfuelduringthetransition periodis4F.Afterthistransition>

the0Westinghouse ECCSanalysiswillapplytoafull-core OFAwithoutthecrossflowpenalty.Inadditiontothefactorsidentified above<theburnuplevelsand/orpowerlevelsoftheENCfuelfurtherassurethatthelimitingfuelistheOFAfuel.ThelastregionofENCfuelwasloadedin1983.Fourofthesefuelassemblies haveburnupsofatleast11,000MWD/MTU<whiletheotherassemblies inthisregionhaveburnuplevelsinexcessof20>000MWD/MTU.EightfreshENCfuelassemblies wereloadedduringtheSpring1984refueling out-ageandcurrently haveburnupsinexcessofll>000MWD/MTU.Maxi-mumburnupswillremainbelowthedesignlimitsestablished byENC.TheENCassemblies arenotlocatedinpeakpowerlocations forCycle15buthaveFvaluesatleast5%belowthatinthelimitingOFAlocations.

TheminimummargintotheFlimitpre-0dietedforanENCassemblyoccursatanelevation wheretheFlimitis2.29andthepredicted Fis2.125.Itshouldben8tedthatthisvalueispredicted b2sedonloadfollowoperation<

whileGinnatypically operatesbaseloaded.Asdescribed inourletterdatedApril10<1984<wehaveloadedfourENCannularfuelpelletdemonstration assemblies duringthecurrentCycle14-15refueling outage.Inadditiontothefueltemperature andstoredenergybenefitswhichderivefromtheuseofanannularfuelpellet,theseassemblies areloadedinthecoreperiphery andhaveassemblypowerlevelslessthan0.8timescoreaveragepower.Theseassemblies havebeenexplicitly modeledinthemostrecentWestinghouse reloadanalysis.

Thus>theseassemblies alsoareboundedbytheOFAfuelanalysis.

ROCHESTER GASANPELECTRICCORP.pATENarch26,l985ToNr.JohnA.zwolinski SHEETNO.Forthereasonsstatedaboveiwehaveconcluded thattheanalysesperformed byWestinghouse withtheapprovedWestinghouse evaluation modelsboundallfuelcurrently loadedintheGinnareactor.Thisevaluation demonstrates thatthelimitingfueltypeistheWestinghouse OFAfuel.Thus<norelianceiscurrently madebytheENCLOCAmodelsandpotential concernsregarding thosecodesdonotapplytoGinna.ytrulyyoursiRogerW.Kober

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