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| | issue date = 04/21/1999 | | | issue date = 04/21/1999 |
| | title = Forwards Response to NRC 990208 RAI Re NMPC 961121 Submittal Re Revised Previous Responses to GL 95-07 Based Upon Further Review of Method for Evaluating Pressure Locking & Thermal Binding.Supporting Calculation Encl | | | title = Forwards Response to NRC 990208 RAI Re NMPC 961121 Submittal Re Revised Previous Responses to GL 95-07 Based Upon Further Review of Method for Evaluating Pressure Locking & Thermal Binding.Supporting Calculation Encl |
| | author name = ABBOTT R B | | | author name = Abbott R |
| | author affiliation = NIAGARA MOHAWK POWER CORP. | | | author affiliation = NIAGARA MOHAWK POWER CORP. |
| | addressee name = | | | addressee name = |
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| {{#Wiki_filter:CATEGORY1yREGULATRYINFORMATIONDISTRIBUTIONSYSTEM(RIDS)ACCESSIONNBR:990%300067DOC.DATE:99/04/21NOTARIZEDNODOCKET¹FACIL:50-410NineMilePointNuclearStation,Unit2,NiagaraMoha05000410AUTH.NAMEAUTHORAFFILIATIONABBOTT,R.B.NiagaraMohawkPowerCorp.RECIP.NAMERECIPIENTAFFILIATIONRecordsManagementBranch(DocumentControlDesk) | | {{#Wiki_filter:CATEGORY 1y REGULAT RY INFORMATION DISTRIBUTION SYSTEM (RIDS) |
| | ACCESSION NBR:990%300067 DOC.DATE: 99/04/21 NOTARIZED NO DOCKET ¹ FACIL:50-410 Nine Mile Point Nuclear Station, Unit 2, Niagara Moha 05000410 AUTH. NAME AUTHOR AFFILIATION ABBOTT,R.B. Niagara Mohawk Power Corp. |
| | RECIP.NAME RECIPIENT AFFILIATION Records Management Branch (Document Control Desk) |
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| ==SUBJECT:== | | ==SUBJECT:== |
| ForwardsresponsetoNRC990208RAIreNMPC961121submittalorrevisedpreviousresponsestoGL95-07baseduponfurtherQreviewofmethodforevaluatingpressurelocking&thermalbinding.Supprotingcalculationencl.ADISTRIBUTIONCODE:A056DCOPIESRECEIVED:LTRENCLSIZE:0TITLE:GenericLtr95-07-PressureLocking&,ThermalBindingofSafetyRelaENOTES:RECIPIENTIDCODE/NAMENRR/DLPM/EATONHOOD,DINTERNALEXTERNAL:NOACNUDOCSABSTRACTCOPIESLTTRENCL1111111111RECIPIENTIDCODE/NAMELPD1-1PDNRR/DE/EMEB/BNRC"<PDRCOPIESLTTRENCL111111D0ENNOTETOALL"RIDS"RECIPIENTS:PLEASEHELPUSTOREDUCEWASTE.TOHAVEYOURNAMEORORGANIZATIONREMOVEDFROMDISTRIBUTIONLISTSORREDUCETHENUMBEROFCOPIESRECEIVEDBYYOUORYOURORGANIZATION,CONTACTTHEDOCUMENTCONTROLDESK(DCD)ONEXTENSION415-2083TOTALNUMBEROFCOPIESREQUIRED:LTTR8ENCL8
| | Forwards response to NRC 990208 RAI re NMPC 961121 submittal or revised previous responses to GL 95-07 based upon further Q review of method for evaluating pressure locking & thermal binding.Supproting calculation encl. A DISTRIBUTION CODE: A056D TITLE: Generic Ltr COPIES RECEIVED:LTR 95 Pressure Locking &, |
| | ENCL SIZE: |
| | Thermal Binding of Safety Rela 0 |
| | E NOTES: |
| | RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL NRR/DLPM/EATON 1 1 LPD1-1 PD 1 1 HOOD,D 1 1 INTERNAL 1 1 NRR/DE/EMEB/B 1 1 EXTERNAL: NOAC 1 1 NRC "<PDR 1 1 NUDOCS ABSTRACT 1 1 D |
| | 0 E |
| | N NOTE TO ALL "RIDS" RECIPIENTS: |
| | PLEASE HELP US TO REDUCE WASTE. TO HAVE YOUR NAME OR ORGANIZATION REMOVED FROM DISTRIBUTION LISTS OR REDUCE THE NUMBER OF COPIES RECEIVED BY YOU OR YOUR ORGANIZATION, CONTACT THE DOCUMENT CONTROL DESK (DCD) ON EXTENSION 415-2083 TOTAL NUMBER OF COPIES REQUIRED: LTTR 8 ENCL 8 |
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| ~~NiagaraQ$5Mohawk'ichardB.AbbottVicePresidentNuclearfngineeringApril21,1999NMP2L1862Phone:315.349.1812Fax:315.349.4417U.S.NuclearRegulatoryCommissionAttn:DocumentControlDeskWashington,DC20555NineMilePointUnit2DocketNo.50-410 | | ~ ~ |
| | Niagara Q$ |
| | 5Mohawk'ichard B. Abbott Phone: 31 5.349.1812 Vice President Fax: 315.349.4417 Nuclear fngineering April 21, 1999 NMP2L 1862 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555 Nine Mile Point Unit 2 Docket No. 50-410 |
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| ==Subject:== | | ==Subject:== |
| GenericLetter95-07,"PressureLockingandT/dermalBindingofSafety-RelatedPotver-OperatedGateValves"Gentlemen:OnAugust17,1995,theNRCissuedGenericLetter(GL)95-07,"PressureLockingandThermalBindingofSafety-RelatedPower-OperatedGateValves,"torequestthatlicenseestakeactionstoensurethatsafety-relatedpower-operatedgatevalvessusceptibletopressure'lockingorthermalbinding,arecapableofperformingtheirsafetyfunctions.BylettersdatedOctober16,1995,andFebruary13,1996,NiagaraMohawkPowerCorporation(NMPC)providedresponsestoGL95-07.TheNRCStaffrequestedadditionalinformationonMay21,1996,towhichwerespondedonJune20,1996.OnNovember21,1996,NMPCrevisedpreviousresponsestoGL95-07baseduponfurtherreviewofourmethodforevaluatingpressurelockingandthermalbinding.ByletterdatedFebruary8,1999,theStaffindicatedthatadditionalinformationwasrequiredconcerningourNovember21,1996,submittal.TheAttachmenttothisletterprovidestherequestedinformation.Sincerely,RichardB.AbbottVicePresident-NuclearEngineeringRBA~JMTikap,'qoes00067v904.2xAttachmentIPDRADOCK05000410iPPDRxc:Mr.H.J.Miller,NRCRegionalAdministratorMr.S.S.Bajwa,Director,ProjectDirectorateI-l,NRRMr.G.K.Hunegs,SeniorResidentInspectorMr.D.S.Hood,SeniorProjectManager,NRRRecordsManagementNineMilePointNuclearStationPO.Box63,Lycoming,NewYork130930063~www.nimo.corn
| | Generic Letter 95-07, "Pressure Locking and T/dermal Binding of Safety-Related Potver-Operated Gate Valves" Gentlemen: |
| | On August 17, 1995, the NRC issued Generic Letter (GL) 95-07, "Pressure Locking and Thermal Binding of Safety-Related Power-Operated Gate Valves," to request that licensees take actions to ensure that safety-related power-operated gate valves susceptible to pressure |
| | 'locking or thermal binding, are capable of performing their safety functions. By letters dated October 16, 1995, and February 13, 1996, Niagara Mohawk Power Corporation (NMPC) provided responses to GL 95-07. The NRC Staff requested additional information on May 21, 1996, to which we responded on June 20, 1996. |
| | On November 21, 1996, NMPC revised previous responses to GL 95-07 based upon further review of our method for evaluating pressure locking and thermal binding. By letter dated February 8, 1999, the Staff indicated that additional information was required concerning our November 21, 1996, submittal. The Attachment to this letter provides the requested information. |
| | Sincerely, Richard B. Abbott Vice President - Nuclear Engineering RBA~JMTikap,'qoes00067 v904.2x Attachment PDR ADOCK 05000410 i I |
| | P PDR xc: Mr. H. J. Miller, NRC Regional Administrator Mr. S. S. Bajwa, Director, Project Directorate I-l, NRR Mr. G. K. Hunegs, Senior Resident Inspector Mr. D. S. Hood, Senior Project Manager, NRR Records Management Nine Mile Point Nuclear Station PO. Box 63, Lycoming, New York 13093 0063 ~ www.nimo.corn |
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| YourNovember21,1996,submittalstatesthattheRCIC-steam-exhaust-to-suppression-poolvalve,2ICS*MOV122,issusceptibletothermalbinding.Italsostatesthatnocorreciive'ctionisrequiredbecausethevalvewouldbedeclaredinoperableandaTechnicalSpeci+cationPS)actionstatementwouldbeentered.Pleaseclarifywhenthevalve~ouldbedeclaredinoperable(i.e.,theinstantthevalveclosedorwhenthevalvefailedtoopen?).Resyaasa:TherelationshipofthisvalvetoReactorCoreIsolationCooling(RCIC)SystemoperabilityandTechnicalSpecificationactionsneedstobeclarified.Duringsurveillancetesting,oranyothersituationthatwouldrequirethisvalvetobeclosed,priortoclosingthevalvetheRCICsystemisdeclaredinoperableduetothefunctionofthisvalveasaturbineexhaustpathway.OncetheRCICSystemisdeclaredinoperable,theplantisina14dayactionstatement.Attheendofthisactionstatement,ifthevalveisnotreopened,aplantshutdownisrequired.Therefore,thesituationunderwhichthevalveissubjecttothermalbinding(i.e.,closed)isthesamesituationwhichrequiresentryintotheshutdownactionstatementduetoRCICSystemTechnicalSpecificationrequirements.Youperformedcalculationsfornumerousvalvestodemonstratethattheycouldoperatewithoutpressurelocking.IfadditionalcalculationshavebeenperformedthatchangetheNovember21,1996resultsregardingthevalveslistedbelow,thenprovidethosecalculations.Youevaluatedthefollowingvalvesashavingadequateactuatorcapacitytoovercomepressurelockingscenariosatthespecificpointofoperationduringanaccident;therefore,youplannomodijfcationforpressurelockingmitigation:2CSH*MOV1012CSL*MOV1072ICS*MOV1212ICS*MOV1222ICS*MOV1292ICS*MOV1282RHS*MOV4A/B/CHighPressureCoreSpray(HPCS)PumpSuctionIsolationLowPressureCoreSpray(LPCS)PumpMinimumFlowBypassIsolationReactorCoreIsolationCooling(RCIC)SteamSupplyOutboardIsolationRCICSteamZxhausttoSuppressionPoolRCICPumpSuctionIsolationRCICSteamSupplyInboardIsolationResidualHeatRemoval(RHR)LoopPumpMinimumFlowIsolation
| | Your November 21, 1996, submittal states that the RCIC-steam-exhaust-to-suppression-pool valve, 2ICS*MOV122, is susceptible to thermal binding. It also states that no correciive'ction is required because the valve would be declared inoperable and a Technical Speci+cation PS) action statement would be entered. Please clarify when the valve ~ould be declared inoperable (i.e., the instant the valve closed or when the valve failed to open?). |
| | Resyaasa: |
| | The relationship of this valve to Reactor Core Isolation Cooling (RCIC) System operability and Technical Specification actions needs to be clarified. During surveillance testing, or any other situation that would require this valve to be closed, prior to closing the valve the RCIC system is declared inoperable due to the function of this valve as a turbine exhaust pathway. |
| | Once the RCIC System is declared inoperable, the plant is in a 14 day action statement. At the end of this action statement, if the valve is not reopened, a plant shutdown is required. |
| | Therefore, the situation under which the valve is subject to thermal binding (i.e., closed) is the same situation which requires entry into the shutdown action statement due to RCIC System Technical Specification requirements. |
| | You performed calculations for numerous valves to demonstrate that they could operate without pressure locking. Ifadditional calculations have been performed that change the November 21, 1996 results regarding the valves listed below, then provide those calculations. |
| | You evaluated the following valves as having adequate actuator capacity to overcome pressure locking scenarios at the specific point of operation during an accident; therefore, you plan no modijfcation for pressure locking mitigation: |
| | 2CSH*MOV101 High Pressure Core Spray (HPCS) Pump Suction Isolation 2CSL*MOV107 Low Pressure Core Spray (LPCS) Pump Minimum Flow Bypass Isolation 2ICS*MOV121 Reactor Core Isolation Cooling (RCIC) Steam Supply Outboard Isolation 2ICS*MOV122 RCIC Steam Zxhaust to Suppression Pool 2ICS*MOV129 RCIC Pump Suction Isolation 2ICS*MOV128 RCIC Steam Supply Inboard Isolation 2RHS*MOV4A/B/C Residual Heat Removal (RHR) Loop Pump Minimum Flow Isolation |
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| 2RHS*MOV1152RHS*MOVI162SWP*MOVI7A/B2SWP*MOV18A/B2SWP*MOV21A/B2SWP*MOV66A/B2SWP*MOV67A/B2SWP*MOV94A/BServiceWater(SW)/RHRContainmentFloodingCrossTieSW/RHRContainmentFloodingCrossTieIsolationSWtoSpentFuelCooling(SFC)HeatExchangerIsolationSWfromSFCHeatExchangerIsolationSWSpentFuelPoolMakeupIsolationSWReturnIsolationFromDieselGenerator(DG)CoolerSWtoControlRoomChillerIsolationSWReturnFromHPCSDGCoolerIsolationRegardingthemethodologyusedforthesecalculations,discuss:2.1Minimummarginsthatshouldbeappliedbeoveencalculatedpressure-lockingthrustandactuatorcapability,2.2Anydiagnosticequipmentaccuracyrequirements,and2.3Methodologylimitations.2.4Isthismethodologyusedforflexibleand/ordoublediskgatevalves?2.5Hoivdidyouvalidatethismethodology?InNovember21,1996,NiagaraMohawkPowerCorporation(NMPC)indicatedthattwentythree(23)valveshaveadequateactuatorcapacitytoovercometheapplicablepressurelockingscenarios.ThiswasbasedonthemethodologyusedbyNMPCatthattime.NMPChasre-evaluated(seeEnclosureforarevisedcalculationandthecalculationdisposition)these23valvesasdescribedbelow:(1)Eight(8)valvesmeettheCommonwealthEdisonmethodologyplusanadditional20%margin.(2)One(1)valvehasalreadybeenmodifiedtomeettheCommonwealthEdisonmethodologyplusanadditional20%margin.(3)Three(3)valvesmeettheCommonwealthEdisonmethodology,butnottheadditional20%marginandwillbemodified.However,themethodologyusedtodeterminethepressureincreaseinthebonnetisveryconservative.Iffurtherevaluationofthevalve(s)confirm(s)thatmodification(s)is(are)notrequired,NMPCwillnotifytheStaff.(4)Six(6)valvesdonotmeettheCommonwealthEdisonmethodologyandwillbemodified.However,themethodologyusedtodeterminethepressureincreaseinthebonnetisveryconservative.Iffurtherevaluationofthevalve(s)confirm(s)thatmodification(s)is(are)notrequired,NMPCwillnotifytheStaff. | | 2RHS*MOV115 Service Water (SW)/RHR Containment Flooding Cross Tie 2RHS*MOVI16 SW/RHR Containment Flooding Cross Tie Isolation 2SWP*MOVI7A/B SW to Spent Fuel Cooling (SFC) Heat Exchanger Isolation 2S WP*MOV18A/B SWfrom SFC Heat Exchanger Isolation 2SWP*MOV21A/B SW Spent Fuel Pool Makeup Isolation 2SWP*MOV66A/B SW Return Isolation From Diesel Generator (DG) Cooler 2SWP*MOV67A/B SW to Control Room Chiller Isolation 2SWP*MOV94A/B SW Return From HPCS DG Cooler Isolation Regarding the methodology used for these calculations, discuss: |
| | 2.1 Minimum margins that should be applied beoveen calculated pressure-locking thrust and actuator capability, 2.2 Any diagnostic equipment accuracy requirements, and 2.3 Methodology limitations. |
| | 2.4 Is this methodology used forflexible and/or double disk gate valves? |
| | 2.5 Hoiv did you validate this methodology? |
| | In November 21, 1996, Niagara Mohawk Power Corporation (NMPC) indicated that twenty three (23) valves have adequate actuator capacity to overcome the applicable pressure locking scenarios. This was based on the methodology used by NMPC at that time. NMPC has re-evaluated (see Enclosure for a revised calculation and the calculation disposition) these 23 valves as described below: |
| | (1) Eight (8) valves meet the Commonwealth Edison methodology plus an additional 20% margin. |
| | (2) One (1) valve has already been modified to meet the Commonwealth Edison methodology plus an additional 20% margin. |
| | (3) Three (3) valves meet the Commonwealth Edison methodology, but not the additional 20% margin and will be modified. However, the methodology used to determine the pressure increase in the bonnet is very conservative. If further evaluation of the valve(s) confirm(s) that modification(s) is (are) not required, NMPC will notify the Staff. |
| | (4) Six (6) valves do not meet the Commonwealth Edison methodology and will be modified. However, the methodology used to determine the pressure increase in the bonnet is very conservative. If further evaluation of the valve(s) confirm(s) that modification(s) is (are) not required, NMPC will notify the Staff. |
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| (5)Five(5)valveshavebeenfurtherevaluatedandhavebeendeterminednottobesubjectedtopressurelockingorthermalbindingatthetimewhentheyarerequiredtooperatetofulfilltheirsafetyfunction.Therefore,nomodificationisrequired.Thesefivecategoriesofthe23flexiblewedgegatevalvesarediscussedingreaterdetailbelow.2ICS*MOV122,21CS*MOV128,2SWP*MOV17A/B,2SWP*MOV18A/B,2SWP*MOV94Aand2SWP*MOV67AThesevalveshaveapositiveopenthrustmarginusingtheCommonwealthEdisonmethodologyplusanadditional20%margin.2SWP*MOV67BThisvalve'snormalpositioniseitheropenorclosedandwasmodifiedduringRFO6providingsufficientopeningthrustmargintosatisfytheCommonwealthEdisonmethodologyplusanadditional20%margin.2SWP*MOV66A/BThesearenormallyclosedvalveswithanactivesafetyrelatedfunctiontoopenandpermitservicewaterreturnflowfromtherespectiveEmergencyDieselGenerator.ThesevalvesarecapableofopeningagainstthetemperatureinducedpressurelockingforceusingtheCommonwealthEdisonmethodology,butnotsufficienttoaccountfortheadditional20%margin.ThesevalveswillbemodifiedpriortotheendofRefuelingOutage7(RFO7)toprovideadditionalmargin.However,iffurtherevaluationofthevalve(s)confirm(s)thatamodification(s)is(are)notrequired,NMPCwillnotifytheStaff.2SWP*MOV94BThisisanormallyclosedvalvewithanactivesafetyrelatedfunctiontoopen,allowingservicewaterreturnflowfromtherespectiveEmergencyDieselGenerator.ThisvalveiscapableofopeningagainstthetemperatureinducedpressurelockingforceusingtheCommonwealthEdisonmethodology,butnotsufficienttoaccountfortheadditional20%margin.ThisvalvewillbemodifiedpriortotheendofRFO7toprovideadditionalmargin.However,iffurtherevaluationofthevalveconfirmsthatamodificationisnotrequired,NMPCwillnotifytheStaff.2CSL*MOV107ThisistheLowPressureCoreSpray(LPCS)pumpminimumflowvalve.Itisanormallyopenvalvewhichisrequiredtocloseformaximizinginjectionflowafterpumpflowisestablishedgreaterthantherequiredminimumflow.ThevalvewillbemodifiedpriortotheendofRFO7tomeettheCommonwealthEdisonmethodologyplusanadditional20%margin.However,iffurtherevaluationofthevalveconfirmsthatamodificationisnotrequired,NMPCwillnotifytheStaff.2RHS*MOV4A/B/CThesearetheminimumflowvalvesforthethreeResidualHeat | | (5) Five (5) valves have been further evaluated and have been determined not to be subjected to pressure locking or thermal binding at the time when they are required to operate to fulfilltheir safety function. Therefore, no modification is required. |
| | These five categories of the 23 flexible wedge gate valves are discussed in greater detail below. |
| | 2ICS*MOV122, 21CS*MOV128, 2SWP*MOV17A/B, 2SWP*MOV18A/B, 2SWP*MOV94A and 2SWP*MOV67A These valves have a positive open thrust margin using the Commonwealth Edison methodology plus an additional 20% margin. |
| | 2SWP*MOV67B This valve's normal position is either open or closed and was modified during RFO6 providing sufficient opening thrust margin to satisfy the Commonwealth Edison methodology plus an additional 20% margin. |
| | 2SWP*MOV66A/B These are normally closed valves with an active safety related function to open and permit service water return flow from the respective Emergency Diesel Generator. |
| | These valves are capable of opening against the temperature induced pressure locking force using the Commonwealth Edison methodology, but not sufficient to account for the additional 20% margin. These valves will be modified prior to the end of Refueling Outage 7 (RFO7) to provide additional margin. However, if further evaluation of the valve(s) confirm(s) that a modification(s) is (are) not required, NMPC will notify the Staff. |
| | 2SWP*MOV94B This is a normally closed valve with an active safety related function to open, allowing service water return flow from the respective Emergency Diesel Generator. |
| | This valve is capable of opening against the temperature induced pressure locking force using the Commonwealth Edison methodology, but not sufficient to account for the additional 20% |
| | margin. This valve will be modified prior to the end of RFO7 to provide additional margin. |
| | However, if further evaluation of the valve confirms that a modification is not required, NMPC will notify the Staff. |
| | 2CSL*MOV107 This is the Low Pressure Core Spray (LPCS) pump minimum flow valve. It is a normally open valve which is required to close for maximizing injection flow after pump flow is established greater than the required minimum flow. The valve will be modified prior to the end of RFO7 to meet the Commonwealth Edison methodology plus an additional 20% |
| | margin. However, if further evaluation of the valve confirms that a modification is not required, NMPC will notify the Staff. |
| | 2RHS*MOV4A/B/C These are the minimum flow valves for the three Residual Heat |
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| Removal(RHR)pumps.Theyarenormallyopenvalveswhichremainopenduringpumpstartandmustclosetomaximizeinjectionflowintothereactor.Afterclosure,thesevalvesmayhavetoreopenforothersystemfunctions.ThesevalveswillbemodifiedpriortotheendofRFO7tomeettheCommonwealthEdisonmethodologyplusanadditional20%margin.However,iffurtherevaluationofthevalve(s)confirm(s)thatamodification(s)is(are)notrequired,NMPCwillnotifytheStaff.2RHS*MOV115and2RHS*MOV116Thesevalvesarepositionedinseriesandarenormallyclosed.TheyopentoprovideanRHRintertie.withServiceWaterincasecontainmentfloodingisrequired.ThesevalveswillbemodifiedpriortotheendofRFO7tomeettheCommonwealthEdisonmethodologyplusanadditional20%margin.However,iffurtherevaluationofthevalve(s)confirm(s)thatmodification(s)is(are)notrequired,NMPCwillnotifytheStaff.2ICS*MOV121ThisistheRCICoutboardcontainmentisolationvalve.Thisisanormallyopenvalvewithanactivesafetyrelatedfunctiontocloseuponanisolationsignal(RCIClinebreak).Onceclosed,thereisnodesignbasisrequirementthatthevalvebere-opened.Novalvemodificationisrequired.2ICS*MOV129ThisistheRCICsuctionvalvefromtheCondensateStorageTank(CST).ItisanormallyopenvalvewithanactivesafetyrelatedfunctiontoclosefortransferringsuctionfromtheCSTtothesuppressionpool.Oncethevalveisclosedandthesuctiontransferisaccomplished,thereisnodesignbasisrequirementthatthevalvebere-opened.Novalvemodificationisrequired.2SWP*MOV21A/BThesearenormallyclosedvalveswithanactivesafetyrelatedfunctiontoopenandprovideServiceWatermakeuptothespentfuelpool.Theambienttemperatureatthelocationofthesevalveswillbesufficientlyreducedsuchthatthepressurelockingconditionsnolongerexistwhenthevalvesarerequiredtofunction.Novalvemodificationisrequired.2CSH*MOV101ThisistheHighPressureCoreSpray(HPCS)suctionvalvefromtheCSTTank.ItisavalvewhichisnormallyopenwithanactivesafetyrelatedfunctiontoclosefortransferringHPCSpumpsuctionfromtheCSTtothesuppressionpool.Oncethevalveisclosedandthesuctiontransferisaccomplished,thereisnodesignbasisrequirementthatthevalvebere-opened.Novalvemodificationisrequired.:AnydiagnosticequipmentaccuracyrequirementsTherandommeasurementuncertaintyforthestaticunseatingthrustisassumedtobenomorethan+/-15%.:Methodologylimitations.TheCommonwealthEdisonpressurelockingmethodologyisvalidforallflexiblewedgegatevalves. | | Removal (RHR) pumps. They are normally open valves which remain open during pump start and must close to maximize injection flow into the reactor. After closure, these valves may have to reopen for other system functions. These valves will be modified prior to the end of RFO7 to meet the Commonwealth Edison methodology plus an additional 20% margin. |
| t~' | | However, if further evaluation of the valve(s) confirm(s) that a modification(s) is (are) not required, NMPC will notify the Staff. |
| dIgydj'lilldldllCh*kgThemethodologywasusedonflexiblegatevalves.Therearenodoublediskgatessubjecttopressurelockingconditions.:Howdidyouvalidatethismethodology?NMPCusedtheNRCendorsedCommonwealthEdisonmethodologyincludinga20%margin.
| | 2RHS*MOV115 and 2RHS*MOV116 These valves are positioned in series and are normally closed. They open to provide an RHR intertie. with Service Water in case containment flooding is required. These valves will be modified prior to the end of RFO7 to meet the Commonwealth Edison methodology plus an additional 20% margin. However, if further evaluation of the valve(s) confirm(s) that modification(s) is (are) not required, NMPC will notify the Staff. |
| 0~~h*If | | 2ICS*MOV121 This is the RCIC outboard containment isolation valve. This is a normally open valve with an active safety related function to close upon an isolation signal (RCIC line break). Once closed, there is no design basis requirement that the valve be re-opened. No valve modification is required. |
| }} | | 2ICS*MOV129 This is the RCIC suction valve from the Condensate Storage Tank (CST). It is a normally open valve with an active safety related function to close for transferring suction from the CST to the suppression pool. Once the valve is closed and the suction transfer is accomplished, there is no design basis requirement that the valve be re-opened. No valve modification is required. |
| | 2SWP*MOV21A/B These are normally closed valves with an active safety related function to open and provide Service Water makeup to the spent fuel pool. The ambient temperature at the location of these valves will be sufficiently reduced such that the pressure locking conditions no longer exist when the valves are required to function. No valve modification is required. |
| | 2CSH*MOV101 This is the High Pressure Core Spray (HPCS) suction valve from the CST Tank. It is a valve which is normally open with an active safety related function to close for transferring HPCS pump suction from the CST to the suppression pool. Once the valve is closed and the suction transfer is accomplished, there is no design basis requirement that the valve be re-opened. No valve modification is required. |
| | : Any diagnostic equipment accuracy requirements The random measurement uncertainty for the static unseating thrust is assumed to be no more than +/-15%. |
| | : Methodology limitations. |
| | The Commonwealth Edison pressure locking methodology is valid for all flexible wedge gate valves. |
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| | d I gy dj'l ill dl d ll Ch*kg The methodology was used on flexible gate valves. There are no double disk gates subject to pressure locking conditions. |
| | : How did you validate this methodology? |
| | NMPC used the NRC endorsed Commonwealth Edison methodology including a 20% margin. |
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Category:CORRESPONDENCE-LETTERS
MONTHYEARML20217L7971999-10-20020 October 1999 Submits Results of Review of 990521 & 0709 Ltrs Which Provided Core Shroud Insp Results & Tie Rod Stabilizer Assemblies ML20217G1291999-10-15015 October 1999 Forwards Errata to Safety Evaluation for Amend 168 Issued to FOL DPR-63 on 990921.Description of Flow Control Trip Ref Cards to Be Consistent with Application for Amend ML20217K2831999-10-14014 October 1999 Submits Response to NRC Administrative Ltr 99-02, Operating Reactor Licensing Action Estimates, for Fiscal Yrs 2000 & 2001 ML20217H3211999-10-0808 October 1999 Forwards Changed Pages for Issue 5,rev 1 of Nine Mile Point Station Physical Security & Safeguards Contingency Plan,Iaw 10CFR50.54(p).Without Encls ML20212K8601999-10-0606 October 1999 Responds to Concern in 990405 Petition Re Residual Heat Removal Alternate Shutdown Cooling Modes of Operation at Nine Mile Point Nuclear Station,Unit 2 ML20216J9311999-09-30030 September 1999 Forwards Response to NRC 981119 Suppl RAI Re GL 96-06, Assurance of Equipment Operability & Containment Integrity During Design-Basis Accident Conditions ML20212J4651999-09-30030 September 1999 Informs of Completion of mid-cyle PPR of Nine Mile Point Nuclear Station on 990916.Determined That Problems in Areas of Human Performance & Work Control Required Continued Mgt Attention.Historical Listing of Plant Issues Encl ML18040A3701999-09-30030 September 1999 Provides Changes to Application for Amend Re Volumes 1-11 of 981016 Submittal & Discard & Insertion Instructions Re Integration of Proposed Changes,In Response to NRC RAIs ML20212K8641999-09-30030 September 1999 Informs That During 990927 Telcon Between J Williams & J Bobka,Arrangements Were Made for Administration of Exams at Plant During Wk of Feb 14,2000.Preliminary RO & SRO License Applications Should Be Submitted 30 Days Prior Exam ML20212J8831999-09-30030 September 1999 Informs That Util 980810 & 990630 Responses to GL 98-01 & Suppl 1, Y2K Readiness of Computer Sys at NPPs Acceptable. NRC Considers Subj GL to Be Closed for Plant ML20212E9801999-09-23023 September 1999 Submits Info in Response to Request for Estimated Initial Operator Licensing Exam Needs,Per Administrative Ltr 99-03 ML20216F7101999-09-17017 September 1999 Forwards Response to NRC 990806 RAI Re USI A-46,verification of Seismic Adequacy of Mechanical & Electrical Equipment in Operating Reactors.Nrc Is Informed That Actions Required for Resolution of USI A-46 Have Been Completed ML20212B2821999-09-14014 September 1999 Responds to 990712 Correspondence Which Responded to NRC Ltr Re High Failure Rate for Generic Fundamentals Exam of 990407 for Nine Mile Point.Considers Corrective Actions Taken to Be Acceptable ML20212D8981999-09-14014 September 1999 Forwards ISI Summary Rept for Refueling Outage 15 & Flaw Indication Repts.Supporting Info Repts & Calculations, Encl ML20212B2581999-09-10010 September 1999 Requests That Name of Bm Bordenick Be Removed from Nine Mile Point,Units 1 & 2 Service List ML20211P5771999-09-10010 September 1999 Forwards Application for Amends to Licenses DPR-63 & NPF-69, to Transfer Licenses to Amergen Energy Co,Llc.Ts Pages & Proprietary Addendum,Included.Proprietary Encl Withheld ML20212A1341999-09-0707 September 1999 Forwards Summary Rept Secondary Containment Leakage Testing, Dtd June 1999 for Nine Mile Point,Unit 1,IAW TS 6.9.3.f ML20211K8141999-09-0101 September 1999 Forwards Reactor Containment Bldg Ilrt,Iaw Plant TS 6.9.3.e.Testing Confirmed That TS 3.3.3/4.3.3 & 6.16 Primary Containment Leakage Requirements Were Satisfactorily Met ML20211L9221999-09-0101 September 1999 Confirms That Licensee Will Retain Weld 32-WD-050 as IGSCC Category F Until Completion of Reinspection Program,In Response to NRC ML20211J6461999-08-30030 August 1999 Forwards Response to NRC 990625 RAI Re NMPC Responses to GL 92-01,rev 1,supplement 1, Reactor Vessel Structural Integrity ML20211K3001999-08-30030 August 1999 Forwards Semi-Annual Radioactive Effluent Release Rept for 990101-990630 & Revised ODCM, for Nine Mile Point,Unit 1. Format Used for Effluent Data Is Outlined in App B of Regulatory Guide 1.21,rev 1 ML20211K5031999-08-30030 August 1999 Responds to Ltr Addressed to Chairman Dicus, Expressing Concerns Involving 990624 Automatic Reactor Shutdown.Insp Findings & Conclusions Will Be Documented in Insp Repts 50-220/99-06 & 50-410/99-06 by mid-Sept 1999 ML20211H1921999-08-26026 August 1999 Forwards Application for Amend to License DPR-63,supporting Implementation of Noble Metal Chemical Addition by Raising Reactor Water Conductivity Limits in TSs 3.2.3.a,3.2.3.c.1 & 3.2.3.b ML20211P5161999-08-26026 August 1999 Discusses Submitted on Behalf of Niagara Mohawk Power Corp Written Comments Addressing 10CFR2.206 Petition & Request That Ltr & Attached Response Be Withheld from Public Disclosure.Request Denied ML20211G4921999-08-26026 August 1999 Advises That Info Re Comments Addressing 10CFR2.206,dtd 990405 Will Be Withheld from Public Disclosure,In Response to ML20211D7731999-08-20020 August 1999 Forwards Semiannual FFD Program Performance Data Rept Covering Period 990101 Through 990630 ML20211B9371999-08-18018 August 1999 Provides Addl Info Re Application of Method a at Nmp,Unit 1 as Described in Generic Implementation Procedure,Rev 2 (GIP-2),NRC Supplemental SER 2 & Documents Ref in GIP-2 Upon Which GIP-2 Is Based ML18040A3691999-08-16016 August 1999 Forwards Response to NRC 990510 RAI Pertaining to NMP Application for Amend Re Conversion of NMPNS Unit 2 Current TS to Its.Nrc Requested Info Re Several Sections,Including Section 3.6, Containment Sys. ML20210Q0031999-08-11011 August 1999 Informs That Due to Printing Malfunction,Some Copies of Author Ltr Dtd 990726,may Not Have Included Second Page of Encl 2 of Ltr ML20210R6661999-08-10010 August 1999 Confirms Conversation on 990721 Re Concerns of Syracuse Anti-Nuclear Effort on Status of 2.206 Petition (Filed 990524) & Upcoming NRC Performance Review Meeting on Nine Mile Point Units 1 & 2 ML20210R8101999-08-10010 August 1999 Forwards 1998 Annual Repts for NMP & co-tenants,including Rg&E,Energy East Corp/Nyse&G,Chg&E & Long Island Power Authority,Per 10CFR50.71(b) ML20210L5321999-08-0606 August 1999 Forwards List of Subjects Discussed During 990714 Telcon with Representatives of Niagara Mohawk Power Corp on Unit 1 Re USI A-46 Issue ML18041A0711999-07-30030 July 1999 Forwards Rev 1 to NMP2-ISI-006, Second Ten Year Interval ISI Program Plan for Nine Mile Point Nuclear Power Station Unit 2. Significant Changes from Rev 0 Listed ML20210J9351999-07-29029 July 1999 Informs That NMP Is Changing Completion Date for Replacement of Valves Having O Rings with Installed Life Greater than Eight Years.Replacement to Be Completed by 991031, During Hydrogen Monitoring Sys Maintenance Outage ML20216E1491999-07-26026 July 1999 Forwards Two Ltrs Received from NMPC Re Nine Mile Point Unit 1 Core Shroud Related to 10CFR2.206 ML20210E9151999-07-23023 July 1999 Discusses Evaluation of Recirculation Line Weld 32-WD-050 Indication Found During 1997 Refueling Outage (RFO14) at NMPNS Unit 1.Requests Notification of Decision to Retain Category F Classification Until Listed Conditions Satisfied ML20209G7911999-07-12012 July 1999 Provides Info Requested in NRC Re 990407 Generic Fundamentals Exam Failure Causes & Corrective Actions ML20209G3711999-07-12012 July 1999 Provides Final Root Cause Evaluation Re GL 94-03, Intergranular Stress Corrosion Cracking of Core Shrouds in Bwrs, for Unit 1 ML20209G2001999-07-0909 July 1999 Forwards RFO-15 Core Shroud Insp Summary Rept, as Required by GL 94-03, Intergranular Stress Corrosion Cracking of Core Shrouds in BWRs & BWRVIP Rept BWR Core Shroud Insp & Flaw Evaluation Guideline (BWRVIP-01) ML20209F8561999-07-0606 July 1999 Forwards Rev 1 to Nmp,Unit 1 COLR for Cycle 14. Rept Is Being Submitted to Commission in Compliance with TS 6.9.1.f.4 ML20211K5071999-07-0606 July 1999 Submits Concerns Re 990624 Event Involving Automatic Reactor Shutdown.More than 5 Failures Were Identified in Event Number 35857 ML20196J6421999-06-30030 June 1999 Discusses Completion of Licensing Action for GL 96-01, Testing of Safety-Related Logic Circuits, Issued on 960110 ML20209B7071999-06-30030 June 1999 Responds to NRC Request for Info Re Y2K Readiness at Nuclear Facilities,As Contained in GL 98-01,Supp 1, Y2K Readiness of Computer Sys at Nuclear Power Plants. Y2K Readiness Disclosure,Encl ML20211P5271999-06-29029 June 1999 Submits Written Comments Addressing Petition Dtd 990405, Submitted by R Norway as It Relates to Expressed Concerns That Involve NMPC Activities.None of Relief Requested in Petition Warranted ML20196K6461999-06-29029 June 1999 Discusses Ofc of Investigations Rept 1-98-33 Re Unqualified Senior Reactor Operator Assuming Position of Assistant Station Shift Supervisor at Unit 1 on 980616.One Violation Being Cited as Described in Encl NOV ML20209B3501999-06-25025 June 1999 Submits Torus Shell & Coupon Corrosion Rate Determination for Nmpns,Unit 1.Torus Meets ASME Code Requirements,Iaw NRC 920825 & 940811 SERs ML20212J4431999-06-25025 June 1999 Discusses Responses to RAI Re GL 92-01,rev 1,suppl 1, Reactor Vessel Structural Integrity ML20209B3531999-06-25025 June 1999 Informs NRC That All Actions Associated with NRC Bulletin 96-003, Potential Plugging of ECC Suction Strainers by Debris in Bwrs, Has Been Completed.Summary of Actions Completed & Other Pertinent Info Is Provided in Attachment ML20196F5721999-06-23023 June 1999 Forwards Rev 3 to NMP1-IST-003, Third Ten Year Inservice Testing Program Plan, Which Will Begin on 991226.Program Plan Conforms to Requirements of 1989 Edition of ASME Boiler & Pressure Vessel Code.Three Relief Requests,Encl ML20196G1461999-06-23023 June 1999 Informs That Actions Requested in GL 96-01, Testing of Safety-Related Logic Circuits Completed 1999-09-07
[Table view] Category:INCOMING CORRESPONDENCE
MONTHYEARML20217K2831999-10-14014 October 1999 Submits Response to NRC Administrative Ltr 99-02, Operating Reactor Licensing Action Estimates, for Fiscal Yrs 2000 & 2001 ML20217H3211999-10-0808 October 1999 Forwards Changed Pages for Issue 5,rev 1 of Nine Mile Point Station Physical Security & Safeguards Contingency Plan,Iaw 10CFR50.54(p).Without Encls ML18040A3701999-09-30030 September 1999 Provides Changes to Application for Amend Re Volumes 1-11 of 981016 Submittal & Discard & Insertion Instructions Re Integration of Proposed Changes,In Response to NRC RAIs ML20216J9311999-09-30030 September 1999 Forwards Response to NRC 981119 Suppl RAI Re GL 96-06, Assurance of Equipment Operability & Containment Integrity During Design-Basis Accident Conditions ML20212E9801999-09-23023 September 1999 Submits Info in Response to Request for Estimated Initial Operator Licensing Exam Needs,Per Administrative Ltr 99-03 ML20216F7101999-09-17017 September 1999 Forwards Response to NRC 990806 RAI Re USI A-46,verification of Seismic Adequacy of Mechanical & Electrical Equipment in Operating Reactors.Nrc Is Informed That Actions Required for Resolution of USI A-46 Have Been Completed ML20212D8981999-09-14014 September 1999 Forwards ISI Summary Rept for Refueling Outage 15 & Flaw Indication Repts.Supporting Info Repts & Calculations, Encl ML20212B2581999-09-10010 September 1999 Requests That Name of Bm Bordenick Be Removed from Nine Mile Point,Units 1 & 2 Service List ML20211P5771999-09-10010 September 1999 Forwards Application for Amends to Licenses DPR-63 & NPF-69, to Transfer Licenses to Amergen Energy Co,Llc.Ts Pages & Proprietary Addendum,Included.Proprietary Encl Withheld ML20212A1341999-09-0707 September 1999 Forwards Summary Rept Secondary Containment Leakage Testing, Dtd June 1999 for Nine Mile Point,Unit 1,IAW TS 6.9.3.f ML20211K8141999-09-0101 September 1999 Forwards Reactor Containment Bldg Ilrt,Iaw Plant TS 6.9.3.e.Testing Confirmed That TS 3.3.3/4.3.3 & 6.16 Primary Containment Leakage Requirements Were Satisfactorily Met ML20211L9221999-09-0101 September 1999 Confirms That Licensee Will Retain Weld 32-WD-050 as IGSCC Category F Until Completion of Reinspection Program,In Response to NRC ML20211K3001999-08-30030 August 1999 Forwards Semi-Annual Radioactive Effluent Release Rept for 990101-990630 & Revised ODCM, for Nine Mile Point,Unit 1. Format Used for Effluent Data Is Outlined in App B of Regulatory Guide 1.21,rev 1 ML20211J6461999-08-30030 August 1999 Forwards Response to NRC 990625 RAI Re NMPC Responses to GL 92-01,rev 1,supplement 1, Reactor Vessel Structural Integrity ML20211H1921999-08-26026 August 1999 Forwards Application for Amend to License DPR-63,supporting Implementation of Noble Metal Chemical Addition by Raising Reactor Water Conductivity Limits in TSs 3.2.3.a,3.2.3.c.1 & 3.2.3.b ML20211D7731999-08-20020 August 1999 Forwards Semiannual FFD Program Performance Data Rept Covering Period 990101 Through 990630 ML20211B9371999-08-18018 August 1999 Provides Addl Info Re Application of Method a at Nmp,Unit 1 as Described in Generic Implementation Procedure,Rev 2 (GIP-2),NRC Supplemental SER 2 & Documents Ref in GIP-2 Upon Which GIP-2 Is Based ML18040A3691999-08-16016 August 1999 Forwards Response to NRC 990510 RAI Pertaining to NMP Application for Amend Re Conversion of NMPNS Unit 2 Current TS to Its.Nrc Requested Info Re Several Sections,Including Section 3.6, Containment Sys. ML20210R6661999-08-10010 August 1999 Confirms Conversation on 990721 Re Concerns of Syracuse Anti-Nuclear Effort on Status of 2.206 Petition (Filed 990524) & Upcoming NRC Performance Review Meeting on Nine Mile Point Units 1 & 2 ML20210R8101999-08-10010 August 1999 Forwards 1998 Annual Repts for NMP & co-tenants,including Rg&E,Energy East Corp/Nyse&G,Chg&E & Long Island Power Authority,Per 10CFR50.71(b) ML18041A0711999-07-30030 July 1999 Forwards Rev 1 to NMP2-ISI-006, Second Ten Year Interval ISI Program Plan for Nine Mile Point Nuclear Power Station Unit 2. Significant Changes from Rev 0 Listed ML20210J9351999-07-29029 July 1999 Informs That NMP Is Changing Completion Date for Replacement of Valves Having O Rings with Installed Life Greater than Eight Years.Replacement to Be Completed by 991031, During Hydrogen Monitoring Sys Maintenance Outage ML20209G3711999-07-12012 July 1999 Provides Final Root Cause Evaluation Re GL 94-03, Intergranular Stress Corrosion Cracking of Core Shrouds in Bwrs, for Unit 1 ML20209G7911999-07-12012 July 1999 Provides Info Requested in NRC Re 990407 Generic Fundamentals Exam Failure Causes & Corrective Actions ML20209G2001999-07-0909 July 1999 Forwards RFO-15 Core Shroud Insp Summary Rept, as Required by GL 94-03, Intergranular Stress Corrosion Cracking of Core Shrouds in BWRs & BWRVIP Rept BWR Core Shroud Insp & Flaw Evaluation Guideline (BWRVIP-01) ML20209F8561999-07-0606 July 1999 Forwards Rev 1 to Nmp,Unit 1 COLR for Cycle 14. Rept Is Being Submitted to Commission in Compliance with TS 6.9.1.f.4 ML20211K5071999-07-0606 July 1999 Submits Concerns Re 990624 Event Involving Automatic Reactor Shutdown.More than 5 Failures Were Identified in Event Number 35857 ML20209B7071999-06-30030 June 1999 Responds to NRC Request for Info Re Y2K Readiness at Nuclear Facilities,As Contained in GL 98-01,Supp 1, Y2K Readiness of Computer Sys at Nuclear Power Plants. Y2K Readiness Disclosure,Encl ML20211P5271999-06-29029 June 1999 Submits Written Comments Addressing Petition Dtd 990405, Submitted by R Norway as It Relates to Expressed Concerns That Involve NMPC Activities.None of Relief Requested in Petition Warranted ML20209B3501999-06-25025 June 1999 Submits Torus Shell & Coupon Corrosion Rate Determination for Nmpns,Unit 1.Torus Meets ASME Code Requirements,Iaw NRC 920825 & 940811 SERs ML20209B3531999-06-25025 June 1999 Informs NRC That All Actions Associated with NRC Bulletin 96-003, Potential Plugging of ECC Suction Strainers by Debris in Bwrs, Has Been Completed.Summary of Actions Completed & Other Pertinent Info Is Provided in Attachment ML20196G1461999-06-23023 June 1999 Informs That Actions Requested in GL 96-01, Testing of Safety-Related Logic Circuits Completed ML20196F5721999-06-23023 June 1999 Forwards Rev 3 to NMP1-IST-003, Third Ten Year Inservice Testing Program Plan, Which Will Begin on 991226.Program Plan Conforms to Requirements of 1989 Edition of ASME Boiler & Pressure Vessel Code.Three Relief Requests,Encl ML20209B2951999-06-22022 June 1999 Informs That Training Re Pressure Relief Panels Was Completed for Remainder of Target Population on 990226 ML20196E9231999-06-21021 June 1999 Forwards Response to NRC 990510 RAI Re NMP 981116 Application Proposing Changes to TSs to Provide Reasonable Assurance That Coupled neutronic/thermal-hydraulic Instabilities Were Detected & Suppressed in NMPN-1 Reactor ML18040A3651999-06-0707 June 1999 Forwards for Filing Original Application of Central Hudson & Gas & Electric Corp Seeking Extension of Expiration Date of Order,Dtd 980719,issued by Commission ML18040A3661999-06-0404 June 1999 Informs That Entire Attachment to Ltr NMP2L 1862 Dtd 990421, Should Be Replaced with Entire Attachment Being Sent with Present Ltr ML20195C9751999-06-0101 June 1999 Informs That Weld 32-WD-050 Will Be Reclassified Back to GL 88-01 Category a Weld & ASME Code Section XI Insps Will Be Conducted in Next Three Insp Periods ML20195C9601999-05-28028 May 1999 Provides Final Extent of Condition Evaluation Re Failed Cap Screw Beyond Upper Spring.Nmpc Continues to Conclude as Stated in That No Addl Mods Are Needed Other than Those Indicated in Ltr ML20207F1811999-05-24024 May 1999 Petitions NRC to Suspend Operating License of NMP for NMPNS Unit 1 Until Such Time as NMPC Releases Most Recent Insp Data on Plant Core Shroud & Adequate Public Review of Plant Safety Accomplished Because of Listed Concerns ML20195B1861999-05-21021 May 1999 Requests Staff Approval of Proposed Mod to Each of Four Tie Rods Per 10CFR50.55a(a)(3)(i).Summary of Tie Rod Insp Findings,Summary of Root Cause Evaluation of Failure of Cap Screw,Calculation B-13-01739-23 & Summary of Se,Encl ML20207D1541999-05-21021 May 1999 Forwards Issue 5,rev 0 of Physical Security & Safeguards Contingency Plan for Nmpns.Summary of Changes Included to Facilitate Review.Encls Withheld ML20207D5331999-05-21021 May 1999 Forwards Issue 3,Rev 1 of NMP Nuclear Security Training & Qualification Plan.Summary of Changes Is Included with Plan to Provide Basis for Individual Changes & to Facilitate NRC Review.Plan Withheld Per 10CFR2.790 ML20206S2621999-05-16016 May 1999 Expresses Concerns About Safety of Nmp,Unit 1 Nuclear Reactor.Nrc Should Conduct Insp of Reactor Including Area Besides Core Shroud Welds & Publicly Disclose Results at Least Wk Before Restart Date ML20195D5911999-05-13013 May 1999 Submits Final Copy of Open Ltr to Central Ny,With Proposals Re Nine Mile One Core Shroud Insp During Refueling Outage Which Began on 990411 ML20206P1981999-05-11011 May 1999 Forwards Response to NRC RAI Re NMP Previous Responses to GL 96-05, Periodic Verification of Design-Basis of SR Movs, for NMP Units 1 & 2 ML20206R6941999-05-10010 May 1999 Responds to 990413 & 0430 Ltrs Re Apparent Violation Noted in Investigation Rept 1-98-033.Util Agrees with Violation, But Disagrees with Characterization That Violation Was Willful or Deliberate ML20206N0291999-05-0707 May 1999 Forwards Rev 39 to NMP Site Emergency Plan & Revised Epips,Including Rev 1 to EPMP-EPP-03,rev 5 to EPIP-EPP-25 & Rev 5 to EPIP-EPP-28 ML20206G8121999-04-30030 April 1999 Forwards Comments on Draft Reg Guide DG-1083, Content of UFSAR IAW 10CFR50.71(e), Dtd Mar 1999.Util Generally Supports DG-1083 ML20206F7731999-04-22022 April 1999 Forwards Renewal Application for SPDES Permit Number NY-000-1015 for Nmpns,Units 1 & 2 1999-09-07
[Table view] |
Text
CATEGORY 1y REGULAT RY INFORMATION DISTRIBUTION SYSTEM (RIDS)
ACCESSION NBR:990%300067 DOC.DATE: 99/04/21 NOTARIZED NO DOCKET ¹ FACIL:50-410 Nine Mile Point Nuclear Station, Unit 2, Niagara Moha 05000410 AUTH. NAME AUTHOR AFFILIATION ABBOTT,R.B. Niagara Mohawk Power Corp.
RECIP.NAME RECIPIENT AFFILIATION Records Management Branch (Document Control Desk)
SUBJECT:
Forwards response to NRC 990208 RAI re NMPC 961121 submittal or revised previous responses to GL 95-07 based upon further Q review of method for evaluating pressure locking & thermal binding.Supproting calculation encl. A DISTRIBUTION CODE: A056D TITLE: Generic Ltr COPIES RECEIVED:LTR 95 Pressure Locking &,
ENCL SIZE:
Thermal Binding of Safety Rela 0
E NOTES:
RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL NRR/DLPM/EATON 1 1 LPD1-1 PD 1 1 HOOD,D 1 1 INTERNAL 1 1 NRR/DE/EMEB/B 1 1 EXTERNAL: NOAC 1 1 NRC "<PDR 1 1 NUDOCS ABSTRACT 1 1 D
0 E
N NOTE TO ALL "RIDS" RECIPIENTS:
PLEASE HELP US TO REDUCE WASTE. TO HAVE YOUR NAME OR ORGANIZATION REMOVED FROM DISTRIBUTION LISTS OR REDUCE THE NUMBER OF COPIES RECEIVED BY YOU OR YOUR ORGANIZATION, CONTACT THE DOCUMENT CONTROL DESK (DCD) ON EXTENSION 415-2083 TOTAL NUMBER OF COPIES REQUIRED: LTTR 8 ENCL 8
~ ~
Niagara Q$
5Mohawk'ichard B. Abbott Phone: 31 5.349.1812 Vice President Fax: 315.349.4417 Nuclear fngineering April 21, 1999 NMP2L 1862 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555 Nine Mile Point Unit 2 Docket No. 50-410
Subject:
Generic Letter 95-07, "Pressure Locking and T/dermal Binding of Safety-Related Potver-Operated Gate Valves" Gentlemen:
On August 17, 1995, the NRC issued Generic Letter (GL) 95-07, "Pressure Locking and Thermal Binding of Safety-Related Power-Operated Gate Valves," to request that licensees take actions to ensure that safety-related power-operated gate valves susceptible to pressure
'locking or thermal binding, are capable of performing their safety functions. By letters dated October 16, 1995, and February 13, 1996, Niagara Mohawk Power Corporation (NMPC) provided responses to GL 95-07. The NRC Staff requested additional information on May 21, 1996, to which we responded on June 20, 1996.
On November 21, 1996, NMPC revised previous responses to GL 95-07 based upon further review of our method for evaluating pressure locking and thermal binding. By letter dated February 8, 1999, the Staff indicated that additional information was required concerning our November 21, 1996, submittal. The Attachment to this letter provides the requested information.
Sincerely, Richard B. Abbott Vice President - Nuclear Engineering RBA~JMTikap,'qoes00067 v904.2x Attachment PDR ADOCK 05000410 i I
P PDR xc: Mr. H. J. Miller, NRC Regional Administrator Mr. S. S. Bajwa, Director, Project Directorate I-l, NRR Mr. G. K. Hunegs, Senior Resident Inspector Mr. D. S. Hood, Senior Project Manager, NRR Records Management Nine Mile Point Nuclear Station PO. Box 63, Lycoming, New York 13093 0063 ~ www.nimo.corn
Your November 21, 1996, submittal states that the RCIC-steam-exhaust-to-suppression-pool valve, 2ICS*MOV122, is susceptible to thermal binding. It also states that no correciive'ction is required because the valve would be declared inoperable and a Technical Speci+cation PS) action statement would be entered. Please clarify when the valve ~ould be declared inoperable (i.e., the instant the valve closed or when the valve failed to open?).
Resyaasa:
The relationship of this valve to Reactor Core Isolation Cooling (RCIC) System operability and Technical Specification actions needs to be clarified. During surveillance testing, or any other situation that would require this valve to be closed, prior to closing the valve the RCIC system is declared inoperable due to the function of this valve as a turbine exhaust pathway.
Once the RCIC System is declared inoperable, the plant is in a 14 day action statement. At the end of this action statement, if the valve is not reopened, a plant shutdown is required.
Therefore, the situation under which the valve is subject to thermal binding (i.e., closed) is the same situation which requires entry into the shutdown action statement due to RCIC System Technical Specification requirements.
You performed calculations for numerous valves to demonstrate that they could operate without pressure locking. Ifadditional calculations have been performed that change the November 21, 1996 results regarding the valves listed below, then provide those calculations.
You evaluated the following valves as having adequate actuator capacity to overcome pressure locking scenarios at the specific point of operation during an accident; therefore, you plan no modijfcation for pressure locking mitigation:
2CSH*MOV101 High Pressure Core Spray (HPCS) Pump Suction Isolation 2CSL*MOV107 Low Pressure Core Spray (LPCS) Pump Minimum Flow Bypass Isolation 2ICS*MOV121 Reactor Core Isolation Cooling (RCIC) Steam Supply Outboard Isolation 2ICS*MOV122 RCIC Steam Zxhaust to Suppression Pool 2ICS*MOV129 RCIC Pump Suction Isolation 2ICS*MOV128 RCIC Steam Supply Inboard Isolation 2RHS*MOV4A/B/C Residual Heat Removal (RHR) Loop Pump Minimum Flow Isolation
2RHS*MOV115 Service Water (SW)/RHR Containment Flooding Cross Tie 2RHS*MOVI16 SW/RHR Containment Flooding Cross Tie Isolation 2SWP*MOVI7A/B SW to Spent Fuel Cooling (SFC) Heat Exchanger Isolation 2S WP*MOV18A/B SWfrom SFC Heat Exchanger Isolation 2SWP*MOV21A/B SW Spent Fuel Pool Makeup Isolation 2SWP*MOV66A/B SW Return Isolation From Diesel Generator (DG) Cooler 2SWP*MOV67A/B SW to Control Room Chiller Isolation 2SWP*MOV94A/B SW Return From HPCS DG Cooler Isolation Regarding the methodology used for these calculations, discuss:
2.1 Minimum margins that should be applied beoveen calculated pressure-locking thrust and actuator capability, 2.2 Any diagnostic equipment accuracy requirements, and 2.3 Methodology limitations.
2.4 Is this methodology used forflexible and/or double disk gate valves?
2.5 Hoiv did you validate this methodology?
In November 21, 1996, Niagara Mohawk Power Corporation (NMPC) indicated that twenty three (23) valves have adequate actuator capacity to overcome the applicable pressure locking scenarios. This was based on the methodology used by NMPC at that time. NMPC has re-evaluated (see Enclosure for a revised calculation and the calculation disposition) these 23 valves as described below:
(1) Eight (8) valves meet the Commonwealth Edison methodology plus an additional 20% margin.
(2) One (1) valve has already been modified to meet the Commonwealth Edison methodology plus an additional 20% margin.
(3) Three (3) valves meet the Commonwealth Edison methodology, but not the additional 20% margin and will be modified. However, the methodology used to determine the pressure increase in the bonnet is very conservative. If further evaluation of the valve(s) confirm(s) that modification(s) is (are) not required, NMPC will notify the Staff.
(4) Six (6) valves do not meet the Commonwealth Edison methodology and will be modified. However, the methodology used to determine the pressure increase in the bonnet is very conservative. If further evaluation of the valve(s) confirm(s) that modification(s) is (are) not required, NMPC will notify the Staff.
(5) Five (5) valves have been further evaluated and have been determined not to be subjected to pressure locking or thermal binding at the time when they are required to operate to fulfilltheir safety function. Therefore, no modification is required.
These five categories of the 23 flexible wedge gate valves are discussed in greater detail below.
2ICS*MOV122, 21CS*MOV128, 2SWP*MOV17A/B, 2SWP*MOV18A/B, 2SWP*MOV94A and 2SWP*MOV67A These valves have a positive open thrust margin using the Commonwealth Edison methodology plus an additional 20% margin.
2SWP*MOV67B This valve's normal position is either open or closed and was modified during RFO6 providing sufficient opening thrust margin to satisfy the Commonwealth Edison methodology plus an additional 20% margin.
2SWP*MOV66A/B These are normally closed valves with an active safety related function to open and permit service water return flow from the respective Emergency Diesel Generator.
These valves are capable of opening against the temperature induced pressure locking force using the Commonwealth Edison methodology, but not sufficient to account for the additional 20% margin. These valves will be modified prior to the end of Refueling Outage 7 (RFO7) to provide additional margin. However, if further evaluation of the valve(s) confirm(s) that a modification(s) is (are) not required, NMPC will notify the Staff.
2SWP*MOV94B This is a normally closed valve with an active safety related function to open, allowing service water return flow from the respective Emergency Diesel Generator.
This valve is capable of opening against the temperature induced pressure locking force using the Commonwealth Edison methodology, but not sufficient to account for the additional 20%
margin. This valve will be modified prior to the end of RFO7 to provide additional margin.
However, if further evaluation of the valve confirms that a modification is not required, NMPC will notify the Staff.
2CSL*MOV107 This is the Low Pressure Core Spray (LPCS) pump minimum flow valve. It is a normally open valve which is required to close for maximizing injection flow after pump flow is established greater than the required minimum flow. The valve will be modified prior to the end of RFO7 to meet the Commonwealth Edison methodology plus an additional 20%
margin. However, if further evaluation of the valve confirms that a modification is not required, NMPC will notify the Staff.
2RHS*MOV4A/B/C These are the minimum flow valves for the three Residual Heat
Removal (RHR) pumps. They are normally open valves which remain open during pump start and must close to maximize injection flow into the reactor. After closure, these valves may have to reopen for other system functions. These valves will be modified prior to the end of RFO7 to meet the Commonwealth Edison methodology plus an additional 20% margin.
However, if further evaluation of the valve(s) confirm(s) that a modification(s) is (are) not required, NMPC will notify the Staff.
2RHS*MOV115 and 2RHS*MOV116 These valves are positioned in series and are normally closed. They open to provide an RHR intertie. with Service Water in case containment flooding is required. These valves will be modified prior to the end of RFO7 to meet the Commonwealth Edison methodology plus an additional 20% margin. However, if further evaluation of the valve(s) confirm(s) that modification(s) is (are) not required, NMPC will notify the Staff.
2ICS*MOV121 This is the RCIC outboard containment isolation valve. This is a normally open valve with an active safety related function to close upon an isolation signal (RCIC line break). Once closed, there is no design basis requirement that the valve be re-opened. No valve modification is required.
2ICS*MOV129 This is the RCIC suction valve from the Condensate Storage Tank (CST). It is a normally open valve with an active safety related function to close for transferring suction from the CST to the suppression pool. Once the valve is closed and the suction transfer is accomplished, there is no design basis requirement that the valve be re-opened. No valve modification is required.
2SWP*MOV21A/B These are normally closed valves with an active safety related function to open and provide Service Water makeup to the spent fuel pool. The ambient temperature at the location of these valves will be sufficiently reduced such that the pressure locking conditions no longer exist when the valves are required to function. No valve modification is required.
2CSH*MOV101 This is the High Pressure Core Spray (HPCS) suction valve from the CST Tank. It is a valve which is normally open with an active safety related function to close for transferring HPCS pump suction from the CST to the suppression pool. Once the valve is closed and the suction transfer is accomplished, there is no design basis requirement that the valve be re-opened. No valve modification is required.
- Any diagnostic equipment accuracy requirements The random measurement uncertainty for the static unseating thrust is assumed to be no more than +/-15%.
- Methodology limitations.
The Commonwealth Edison pressure locking methodology is valid for all flexible wedge gate valves.
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d I gy dj'l ill dl d ll Ch*kg The methodology was used on flexible gate valves. There are no double disk gates subject to pressure locking conditions.
- How did you validate this methodology?
NMPC used the NRC endorsed Commonwealth Edison methodology including a 20% margin.
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