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{{#Wiki_filter:ACCELERATEDD1SIBUNIONDEMONSTRIONSYSTEM' | {{#Wiki_filter:ACCELERATEDD1SIBUNIONDEMONSTRIONSYSTEM'REGULATORY INFORMATION DISTRIBUTION SYSTEM(RIDS)ACCESSION NBR:8904260177 DOC.DATE: | ||
89/04/14NOTARIZED: | |||
NODOCKETgFACIL:50-315 DonaldC.CookNuclearPowerPlant,Unit1,Indiana&0500031550-316DonaldC.CookNuclearPowerPlant,Unit2,Indiana&05000316AUTH.NAMEAUTHORAFFILIATION ALEXICH,M.P.. | |||
IndianaMichiganPowerCo.(formerly Indiana&MichiganEleRECIP.NAME RECIPIENT AFFILIATION MURLEY,T.E. | |||
DocumentControlBranch(Document ControlDesk)R | |||
==SUBJECT:== | ==SUBJECT:== | ||
RespondstostationblackoutruleforplantsusingACindependent stationblackoutresponsepower.DISTRIBUTION CODE:A050DCOPIESRECEIVED:LTR ENCLSIZE:TITLE:ORSubmittal: | |||
StationBlackout(USIA-44)10CFR50.63, MPAA-22NOTES:RECIPIENT IDCODE/NAME PD3-1PDCOPIESLTTRENCL11RECIPIENT IDCODE/NAME STANG,JCOPIESLTTRENCL11i'INTERNAL: | |||
NRRPDl-4PMTAMNRR/DEST/PS BNUDOCS-ABSTRACT EXTERNAL: | |||
LPDRNSIC1122111111NRR/DEST/ESB NRRDESTRSBRFILE0NRCPDR22111111RINarE'IOALLRICSRZCIPZZgZS PLEASEHELPUSK)REDUCEWASTE!CDNZACZ'XHE DOCUMENZCONTROLDESKSKXMPl-37(EXT.20079)KOELIMINATE KXJRMMEFKHDISTRIBUTION LISTSH)RDOCtIMEÃIS YOUDGNiTNEED!DDSTOTALNUMBEROFCOPIESREQUIRED: | |||
LTTR13ENCL13 19~t0~'1indianahlicbigan PowerCompanyP.O.Box16631Columbus, OH43216AEP:NRC:0537D DonaldC.CookNuclearPlantUnits1and2DocketNos.50-315and50-316LicenseNos.DPR-58andDPR-74GENERICRESPONSETOSTATIONBLACKOUTRULEFORPLANTSUSINGACINDEPENDENT STATIONBLACKOUTRESPONSEPOWERU.S.NuclearRegulatory Commission Attn:DocumentControlDeskWashington, D.C.20555Attn:T.E.MurleyApril14,1989 | |||
==DearDr.Murley:== | ==DearDr.Murley:== | ||
'OnJuly21,1988, | 'OnJuly21,1988,theNuclearRegulatory Commission (NRC)amendeditsregulations in10CFR,Part50.Anewsection,50.63,wasaddedwhichrequiresthateachlight-water-cooled nuclearpowerplantbeabletowithstand andrecoverfromastationblackout(SBO)ofaspecified duration. | ||
Dr.T.E.Murley-3-AEP:NRC: | Utilities areexpectedtohavethebaselineassumptions, analysesandrelatedinformation usedintheircopingevaluation available forNRCreview.Italsoidentifies thefactorsthatmustbeconsidered inspecifying thestationblackoutduration. | ||
Section50.63requiresthat,forthestationblackoutduration, theplantbecapableofmaintaining corecoolingandappropriate containment integrity. | |||
Section50.63furtherrequiresthateachlicenseesubmitthefollowing information: | |||
1.Aproposedstationblackoutdurationincluding ajustification fortheselection basedontheredundancy andreliability oftheonsiteemergency ACpowersources,theexpectedfrequency oflossofoffsitepower,andtheprobabletimeneededtorestoreoffsitepower;2.Adescription oftheprocedures thatwillbeimplemented forstationblackouteventsfortheduration(asdetermined in1above)andforrecoverytherefrom; and3.Alistandproposedscheduleforanyneededmodifications toequipment andassociated procedures necessary forthespecified SBOduration. | |||
8904260i77 8904i4rPDRADOCK05000315PPDCpo Dr.T.E.Murley-2-AEP:NRC:0537D TheNRChasissuedRegulatory guide1.155"StationBlackout" whichdescribes ameansacceptable totheNRCStaffformeetingtherequirements of10CFR50.63.Regulatory Guide(RG)1.155statesthattheNRCStaffhasdetermined thatNUMARC87-00"Guidelines andTechnical BasesforNUMARCInitiatives Addressing StationBlackoutAtLightWaterReactors" alsoprovidesguidancethatisinlargepartidentical totheRG1.155guidanceandisacceptable totheNRCstaffformeetingtheserequirements. | |||
Table1toRG1.155providesacross-reference betweenRG1.155andNUMARC87-00andnoteswheretheRGtakesprecedence. | |||
IndianaMichiganPowerhasevaluated theCookNuclearPlant,Units1and2,againsttherequirements oftheSBOruleusingguidancefromNUMARC87-00exceptwhereRG1.155takesprecedence. | |||
Theresultsofthisevaluation aredetailedbelow.A.ProosedStationBlackoutDurationNUMARC87-00,Section3wasusedtodetermine aproposedSBOdurationoffourhours.Nomodifications wererequiredtoattainthisproposedcopingdurationcategory. | |||
Thefollowing plantfactorswereidentified indetermining theproposedstationblackoutduration: | |||
1.ACPowerDesignCharacteristic GroupisP2basedon:a.Expectedfrequency ofgrid-related loss-of-offsite-power events(LOOPs)-doesnotexceedonceper20years;b.Estimated frequency ofLOOPsduetoextremely severeweather(ESW)placestheplantinESWGroup2;c.Estimated frequency ofLOOPsduetosevereweather(SW)placestheplantinSWGroup2;d.TheoffsitepowersystemisintheGroupIl/2.2.Theemergency ACpowerconfiguration groupis"C"basedon:a.Therearetwoemergency ACpowersuppliesperunitnotcreditedasalternate ACpowersources;b.Oneemergency ACpowersupplyperunitisnecessary tooperatesafeshutdownequipment following alossofoffsitepower. | |||
Dr.T.E.Murley-3-AEP:NRC:0537D 3.Thetargetemergency dieselgenerator (EDG)reliability is0.975.AtargetEDGreliability of0.975wasselectedbasedonhavinganuclearunitaverageEDGreliability forthelast20demandsgreaterthan0'0consistent withNUMARC87-00,Section3.2.4.B.Procedure DescritionPlantprocedures havebeenreviewedand,wherenecessary, willbemodifiedbyJuly31,1989,tomeettheguidelines inNUMARC87-00,Section4inthefollowing areas:StationblackoutresponseperNUMARC87-00,Section4.2.1;ACpowerrestoration perNUMARC87-00,Section4.2.2;SevereweatherperNUMARC87-00,Section4.2.3;Procedures reviewedand/orrevisedarelistedbelow:1,2-0HP4023.ECA-O.O LossofAllACPower;*1,2-0HP4023.001.020 ResponsetoLossofOffsitePowertoBothUnitsandAnyOneDieselStarts;OHI-4011ConductofOperations (ShiftStaffing); | |||
1,2-0HP4021.056.002 Operation ofAuxiliary Feedwater SystemDuringStartupandShutdown; 1,2-0HP4030.STP.017T TurbineDrivenAuxiliary Feedwater SystemTest;1,2-0HP4022.055.003 LossofCondensate toAuxiliary Feedwater Pumps;1-OHP4030.STP.039 SecurityDieselGenerator Operability Test;1,2-0HP4023.001.001 RemoteShutdownProcedures; OHI-5030Preventive Maintenance; 1,2-0HP4023.001.006 LossofControlAir;1,2-0HP4023.ECA-0.1 WithoutSIRequired; LossofAllACPowerRecovery1,2-0HP4023.ECA-0.2 WithSIRequired; LossofAllACPowerRecovery Dr.T.E.Murley-4-AEP:NRC:0537D oPMP2080.EPP.111 NaturalEmergency Guidelines; oPMI4010PlantOperations Policy;*oLoadRestoration Plan,IndianaMichiganPowerCompanySystemOperation Department, August,1988.o1,2-0HP4030.STP.043 SafetyRelatedManualValveCycling;* | |||
o1-THP6030.IMP.146(.246forUnit2)Emergency PlantShutdownandCooldownIndication LocalShutdownIndication o1-THP6030.IMP.327 | |||
(.427forUnit2)SteamGenerator Atmosphere SteamReliefControlCalibration/Alignment | |||
*Procedures requiring modification. | |||
C.ProosedModifications andScheduleTheabilityofCookNuclearPlant,Units1and2,tocopewithastationblackoutforfourhoursinaccordance withNUMARC87-00,Section3.2.5andasdetermined inSection"A"above;wasassessedusingNUMARC87-00,Section7withthefollowing results:Condensate InventorForDecaHeatRemovalSection~7.2.1Ithasbeendetermined fromSection7.2.1ofNUMARC87-00thatapproximately 90,000gallonsofwaterperunitarerequiredfordecayheatremoval,aswellasforprimary/secondary sidepressurereduction, forthefourhourblackoutevent.Theminimumpermissible condensate storagetanklevelpertechnical specifications provides175,000gallonsofwaterperunit,whichexceedstherequiredquantityforcopingwithafour-hour stationblackout. | |||
Class1EBatteriesCaacitSection7.2.2TheClass1Ebatteries weredetermined tobeinadequate tomeetstationblackoutloadsforfourhours.Thefollowing procedure changeisnecessary toprovideafour-hour capacity: | |||
variousloadsnotrequiredtomitigatethestationblackouteventwillbestripped. | |||
Theseloadswillbeidentified inplantprocedures'. | |||
ComressedAirSection7.2.3Procedure changesarenecessary toensurethatair-operated valvesrequiredfordecayheatremoval Dr.T.EDMurley-5-AEP:NRC:0537D duringastationblackoutofafour-hour durationhavesufficient backupsourcesforoperation orwillbemanuallyoperated. | |||
Valvesrequiring manualoperation orthatneedbackupsources(i.e.,steamgenerator power-operated reliefvalves)foroperation willbeidentified inplantprocedures. | |||
4.EffectsofLossofVentilation Section7.2.4Thecalculated steadystateambientairtemperature forthesteamdrivenauxiliary feedwater pumproom(thedominantareaofconcernforaPWR)duringastation0blackoutinducedlossofventilation is133.6F.Theassumption inNUMARC87-00,Section2'.1thatthecontrolroomwillnotexceed120Fduringthestation0blackouthasbeenassessed. | |||
ThecontrolroomatCookNuclearPlant,Units1and2,doesnotexceed120Fduringastationblackout. | |||
0Therefore, thecontrolroomisnotadominantareaofconcern.Reasonable assurance oftheoperability ofstationblackoutresponseequipment intheabovedominantarea(s)ofconcernhasbeenassessedusingAppendixFtoNUMARC87-00and/ortheNUMARC87-00TopicalReport.Nomodifications orassociated procedures arerequiredtoprovidereasonable assurance forequipment operability. | |||
Containment Isolation Section7.2.5Theplantlistofcontainment isolation valveshasbeenreviewedtoverifythatvalveswhichmustbecapableofbeingclosedorthatmustbeoperated(cycled)understationblackoutconditions canbepositioned (withindication) independent ofthepreferred andblacked-out unitsClass1Epowersupplies. | |||
Noplantmodifications and/orassociated procedure changesweredetermined toberequiredtoensurethatappropriate containment integrity canbeprovidedunderSBOconditions. | |||
6.ReactorCoolantInventorSection2.5Theabilitytomaintainadequatereactorcoolantsysteminventory toensurethatthecoreiscooledhasbeenassessedforfourhours.Aplant-specific analysiswasusedforthisassessment. | |||
Theexpectedratesofreactorcoolantinventory lossunderSBOconditions donotresultincoreuncoveryinaSBOoffourhours.Therefore, makeupsystemsinadditiontothosecurrently Dr.T.E.Murley-6-AEP'NRC:0537D available underSBOconditions arenotrequiredtomaintaincorecoolingundernaturalcirculation (including refluxboiling). | |||
Theprocedure changesidentified inPartsA,BandCabovewillbecompleted byJuly31,1989.Theframework forthisresponseletterwasgenerically preparedbyNUMARCandwasconcurred withbytheNRCstaff.Plantspecificparameters wereprovidedwhereneededandparagraphs selectedastheyappliedtoCookNuclearPlantfromthegenericresponse. | |||
format.NRCstaffconcurrence fortheframework wasprovidedinanOctober7,1988,letterfromMr.A.S.Thadani,Assistant DirectorforSystems,NuclearReactorRegulation, toMr.W.H.RasinofNUMARC.Thisdocumenthasbeenpreparedfollowing Corporate procedures thatincorporate areasonable setofcontrolstoensureitsaccuracyandcompleteness priortosignature bytheundersigned. | |||
Sincerely, P.AlichVicePresident ldpcc:D.H.Williams, Jr.W.G.Smith,Jr.-BridgmanR.C.CallenG.CharnoffA.B.DavisNRCResidentInspector | |||
-BridgmanG.Bruchmann}} | |||
Revision as of 07:55, 29 June 2018
| ML17326B611 | |
| Person / Time | |
|---|---|
| Site: | Cook |
| Issue date: | 04/14/1989 |
| From: | ALEXICH M P INDIANA MICHIGAN POWER CO. (FORMERLY INDIANA & MICHIG |
| To: | MURLEY T E NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| AEP:NRC:0537D, AEP:NRC:537D, NUDOCS 8904260177 | |
| Download: ML17326B611 (7) | |
Text
ACCELERATEDD1SIBUNIONDEMONSTRIONSYSTEM'REGULATORY INFORMATION DISTRIBUTION SYSTEM(RIDS)ACCESSION NBR:8904260177 DOC.DATE:
89/04/14NOTARIZED:
NODOCKETgFACIL:50-315 DonaldC.CookNuclearPowerPlant,Unit1,Indiana&0500031550-316DonaldC.CookNuclearPowerPlant,Unit2,Indiana&05000316AUTH.NAMEAUTHORAFFILIATION ALEXICH,M.P..
IndianaMichiganPowerCo.(formerly Indiana&MichiganEleRECIP.NAME RECIPIENT AFFILIATION MURLEY,T.E.
DocumentControlBranch(Document ControlDesk)R
SUBJECT:
RespondstostationblackoutruleforplantsusingACindependent stationblackoutresponsepower.DISTRIBUTION CODE:A050DCOPIESRECEIVED:LTR ENCLSIZE:TITLE:ORSubmittal:
StationBlackout(USIA-44)10CFR50.63, MPAA-22NOTES:RECIPIENT IDCODE/NAME PD3-1PDCOPIESLTTRENCL11RECIPIENT IDCODE/NAME STANG,JCOPIESLTTRENCL11i'INTERNAL:
NRRPDl-4PMTAMNRR/DEST/PS BNUDOCS-ABSTRACT EXTERNAL:
LPDRNSIC1122111111NRR/DEST/ESB NRRDESTRSBRFILE0NRCPDR22111111RINarE'IOALLRICSRZCIPZZgZS PLEASEHELPUSK)REDUCEWASTE!CDNZACZ'XHE DOCUMENZCONTROLDESKSKXMPl-37(EXT.20079)KOELIMINATE KXJRMMEFKHDISTRIBUTION LISTSH)RDOCtIMEÃIS YOUDGNiTNEED!DDSTOTALNUMBEROFCOPIESREQUIRED:
LTTR13ENCL13 19~t0~'1indianahlicbigan PowerCompanyP.O.Box16631Columbus, OH43216AEP:NRC:0537D DonaldC.CookNuclearPlantUnits1and2DocketNos.50-315and50-316LicenseNos.DPR-58andDPR-74GENERICRESPONSETOSTATIONBLACKOUTRULEFORPLANTSUSINGACINDEPENDENT STATIONBLACKOUTRESPONSEPOWERU.S.NuclearRegulatory Commission Attn:DocumentControlDeskWashington, D.C.20555Attn:T.E.MurleyApril14,1989
DearDr.Murley:
'OnJuly21,1988,theNuclearRegulatory Commission (NRC)amendeditsregulations in10CFR,Part50.Anewsection,50.63,wasaddedwhichrequiresthateachlight-water-cooled nuclearpowerplantbeabletowithstand andrecoverfromastationblackout(SBO)ofaspecified duration.
Utilities areexpectedtohavethebaselineassumptions, analysesandrelatedinformation usedintheircopingevaluation available forNRCreview.Italsoidentifies thefactorsthatmustbeconsidered inspecifying thestationblackoutduration.
Section50.63requiresthat,forthestationblackoutduration, theplantbecapableofmaintaining corecoolingandappropriate containment integrity.
Section50.63furtherrequiresthateachlicenseesubmitthefollowing information:
1.Aproposedstationblackoutdurationincluding ajustification fortheselection basedontheredundancy andreliability oftheonsiteemergency ACpowersources,theexpectedfrequency oflossofoffsitepower,andtheprobabletimeneededtorestoreoffsitepower;2.Adescription oftheprocedures thatwillbeimplemented forstationblackouteventsfortheduration(asdetermined in1above)andforrecoverytherefrom; and3.Alistandproposedscheduleforanyneededmodifications toequipment andassociated procedures necessary forthespecified SBOduration.
8904260i77 8904i4rPDRADOCK05000315PPDCpo Dr.T.E.Murley-2-AEP:NRC:0537D TheNRChasissuedRegulatory guide1.155"StationBlackout" whichdescribes ameansacceptable totheNRCStaffformeetingtherequirements of10CFR50.63.Regulatory Guide(RG)1.155statesthattheNRCStaffhasdetermined thatNUMARC87-00"Guidelines andTechnical BasesforNUMARCInitiatives Addressing StationBlackoutAtLightWaterReactors" alsoprovidesguidancethatisinlargepartidentical totheRG1.155guidanceandisacceptable totheNRCstaffformeetingtheserequirements.
Table1toRG1.155providesacross-reference betweenRG1.155andNUMARC87-00andnoteswheretheRGtakesprecedence.
IndianaMichiganPowerhasevaluated theCookNuclearPlant,Units1and2,againsttherequirements oftheSBOruleusingguidancefromNUMARC87-00exceptwhereRG1.155takesprecedence.
Theresultsofthisevaluation aredetailedbelow.A.ProosedStationBlackoutDurationNUMARC87-00,Section3wasusedtodetermine aproposedSBOdurationoffourhours.Nomodifications wererequiredtoattainthisproposedcopingdurationcategory.
Thefollowing plantfactorswereidentified indetermining theproposedstationblackoutduration:
1.ACPowerDesignCharacteristic GroupisP2basedon:a.Expectedfrequency ofgrid-related loss-of-offsite-power events(LOOPs)-doesnotexceedonceper20years;b.Estimated frequency ofLOOPsduetoextremely severeweather(ESW)placestheplantinESWGroup2;c.Estimated frequency ofLOOPsduetosevereweather(SW)placestheplantinSWGroup2;d.TheoffsitepowersystemisintheGroupIl/2.2.Theemergency ACpowerconfiguration groupis"C"basedon:a.Therearetwoemergency ACpowersuppliesperunitnotcreditedasalternate ACpowersources;b.Oneemergency ACpowersupplyperunitisnecessary tooperatesafeshutdownequipment following alossofoffsitepower.
Dr.T.E.Murley-3-AEP:NRC:0537D 3.Thetargetemergency dieselgenerator (EDG)reliability is0.975.AtargetEDGreliability of0.975wasselectedbasedonhavinganuclearunitaverageEDGreliability forthelast20demandsgreaterthan0'0consistent withNUMARC87-00,Section3.2.4.B.Procedure DescritionPlantprocedures havebeenreviewedand,wherenecessary, willbemodifiedbyJuly31,1989,tomeettheguidelines inNUMARC87-00,Section4inthefollowing areas:StationblackoutresponseperNUMARC87-00,Section4.2.1;ACpowerrestoration perNUMARC87-00,Section4.2.2;SevereweatherperNUMARC87-00,Section4.2.3;Procedures reviewedand/orrevisedarelistedbelow:1,2-0HP4023.ECA-O.O LossofAllACPower;*1,2-0HP4023.001.020 ResponsetoLossofOffsitePowertoBothUnitsandAnyOneDieselStarts;OHI-4011ConductofOperations (ShiftStaffing);
1,2-0HP4021.056.002 Operation ofAuxiliary Feedwater SystemDuringStartupandShutdown; 1,2-0HP4030.STP.017T TurbineDrivenAuxiliary Feedwater SystemTest;1,2-0HP4022.055.003 LossofCondensate toAuxiliary Feedwater Pumps;1-OHP4030.STP.039 SecurityDieselGenerator Operability Test;1,2-0HP4023.001.001 RemoteShutdownProcedures; OHI-5030Preventive Maintenance; 1,2-0HP4023.001.006 LossofControlAir;1,2-0HP4023.ECA-0.1 WithoutSIRequired; LossofAllACPowerRecovery1,2-0HP4023.ECA-0.2 WithSIRequired; LossofAllACPowerRecovery Dr.T.E.Murley-4-AEP:NRC:0537D oPMP2080.EPP.111 NaturalEmergency Guidelines; oPMI4010PlantOperations Policy;*oLoadRestoration Plan,IndianaMichiganPowerCompanySystemOperation Department, August,1988.o1,2-0HP4030.STP.043 SafetyRelatedManualValveCycling;*
o1-THP6030.IMP.146(.246forUnit2)Emergency PlantShutdownandCooldownIndication LocalShutdownIndication o1-THP6030.IMP.327
(.427forUnit2)SteamGenerator Atmosphere SteamReliefControlCalibration/Alignment
- Procedures requiring modification.
C.ProosedModifications andScheduleTheabilityofCookNuclearPlant,Units1and2,tocopewithastationblackoutforfourhoursinaccordance withNUMARC87-00,Section3.2.5andasdetermined inSection"A"above;wasassessedusingNUMARC87-00,Section7withthefollowing results:Condensate InventorForDecaHeatRemovalSection~7.2.1Ithasbeendetermined fromSection7.2.1ofNUMARC87-00thatapproximately 90,000gallonsofwaterperunitarerequiredfordecayheatremoval,aswellasforprimary/secondary sidepressurereduction, forthefourhourblackoutevent.Theminimumpermissible condensate storagetanklevelpertechnical specifications provides175,000gallonsofwaterperunit,whichexceedstherequiredquantityforcopingwithafour-hour stationblackout.
Class1EBatteriesCaacitSection7.2.2TheClass1Ebatteries weredetermined tobeinadequate tomeetstationblackoutloadsforfourhours.Thefollowing procedure changeisnecessary toprovideafour-hour capacity:
variousloadsnotrequiredtomitigatethestationblackouteventwillbestripped.
Theseloadswillbeidentified inplantprocedures'.
ComressedAirSection7.2.3Procedure changesarenecessary toensurethatair-operated valvesrequiredfordecayheatremoval Dr.T.EDMurley-5-AEP:NRC:0537D duringastationblackoutofafour-hour durationhavesufficient backupsourcesforoperation orwillbemanuallyoperated.
Valvesrequiring manualoperation orthatneedbackupsources(i.e.,steamgenerator power-operated reliefvalves)foroperation willbeidentified inplantprocedures.
4.EffectsofLossofVentilation Section7.2.4Thecalculated steadystateambientairtemperature forthesteamdrivenauxiliary feedwater pumproom(thedominantareaofconcernforaPWR)duringastation0blackoutinducedlossofventilation is133.6F.Theassumption inNUMARC87-00,Section2'.1thatthecontrolroomwillnotexceed120Fduringthestation0blackouthasbeenassessed.
ThecontrolroomatCookNuclearPlant,Units1and2,doesnotexceed120Fduringastationblackout.
0Therefore, thecontrolroomisnotadominantareaofconcern.Reasonable assurance oftheoperability ofstationblackoutresponseequipment intheabovedominantarea(s)ofconcernhasbeenassessedusingAppendixFtoNUMARC87-00and/ortheNUMARC87-00TopicalReport.Nomodifications orassociated procedures arerequiredtoprovidereasonable assurance forequipment operability.
Containment Isolation Section7.2.5Theplantlistofcontainment isolation valveshasbeenreviewedtoverifythatvalveswhichmustbecapableofbeingclosedorthatmustbeoperated(cycled)understationblackoutconditions canbepositioned (withindication) independent ofthepreferred andblacked-out unitsClass1Epowersupplies.
Noplantmodifications and/orassociated procedure changesweredetermined toberequiredtoensurethatappropriate containment integrity canbeprovidedunderSBOconditions.
6.ReactorCoolantInventorSection2.5Theabilitytomaintainadequatereactorcoolantsysteminventory toensurethatthecoreiscooledhasbeenassessedforfourhours.Aplant-specific analysiswasusedforthisassessment.
Theexpectedratesofreactorcoolantinventory lossunderSBOconditions donotresultincoreuncoveryinaSBOoffourhours.Therefore, makeupsystemsinadditiontothosecurrently Dr.T.E.Murley-6-AEP'NRC:0537D available underSBOconditions arenotrequiredtomaintaincorecoolingundernaturalcirculation (including refluxboiling).
Theprocedure changesidentified inPartsA,BandCabovewillbecompleted byJuly31,1989.Theframework forthisresponseletterwasgenerically preparedbyNUMARCandwasconcurred withbytheNRCstaff.Plantspecificparameters wereprovidedwhereneededandparagraphs selectedastheyappliedtoCookNuclearPlantfromthegenericresponse.
format.NRCstaffconcurrence fortheframework wasprovidedinanOctober7,1988,letterfromMr.A.S.Thadani,Assistant DirectorforSystems,NuclearReactorRegulation, toMr.W.H.RasinofNUMARC.Thisdocumenthasbeenpreparedfollowing Corporate procedures thatincorporate areasonable setofcontrolstoensureitsaccuracyandcompleteness priortosignature bytheundersigned.
Sincerely, P.AlichVicePresident ldpcc:D.H.Williams, Jr.W.G.Smith,Jr.-BridgmanR.C.CallenG.CharnoffA.B.DavisNRCResidentInspector
-BridgmanG.Bruchmann