ML082540495

North Anna and Surry Power Station, Units 1 and 2, NRC Generic Letter (GL) 2004-02, Potential Impact of Debris Accidents at Pressurized-water Reactors Request for Extension of Completion Dates for Corrective Actions

ML082540495
Person / Time
Site:	Surry, North Anna
Issue date:	09/05/2008
From:	Matthews W R Virginia Electric & Power Co (VEPCO)
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
08-0541, GL-04-002
Download: ML082540495 (8)

Text

VIRGINIA ELECTRIC AND POWER COMPANY RICHMOND, VIRGINIA 23261 September 5, U.S.NuclearRegulatoryCommission Attention:

DocumentControlDeskOneWhiteFlintNorth11555RockvillePikeRockville,MD 20852-2738 2008SerialNo.NL&OS/GDMDocketNos.LicenseNos.

08-0541 RO 50-338/339 50-280/281 NPF-4/7 DPR-32/37 VIRGINIA ELECTRICANDPOWER COMPANY (DOMINION)NORTHANNAANDSURRYPOWERSTATIONUNITS1AND2 NRC GENERIC LETTER(GL)2004-02.

POTENTIAL IMPACT OF DEBRIS BLOCKAGE ON EMERGENCY RECIRCULATIONDURINGDESIGNBASIS ACCIDENTS AT PRESSURIZED-WATER REACTORS REQUEST FOR EXTENSION OF COMPLETIONDATESFOR CORRECTIVE ACTIONSInaletterdated November15,2007(SerialNo.07-0660),DominionsubmittedscheduleextensionrequestsforbothunitsofNorthAnnaandSurryPowerStationstoextendthecompletiondateforcorrectiveactionsassociatedwithGL2004-02.Therequestwasprimarilyforthecompletionof downstream effects evaluationsandchemicaleffectstestingandevaluation.Therequested extensiondatefortheNorthAnnaandSurryunitswas November30,2008.InaletterdatedDecember13,2007,theNRCgrantedDominionanextensiontoMay31,2008citingtheimportanceofpromptclosureofGL2004-02andthepotentialforscheduleimprovement.ItlaterbecameevidentthatnotalloftheremainingcorrectiveactionscouldbecompletedbyMay 31,2008.InaletterdatedMay 21,2008(SerialNo.08-0275),Dominionrequestedanextensionuntil September30,2008tocompleteGL2004-02correctiveactionsforNorthAnnaandSurry.Therequestedextensionperiodwastocompletetheremainingchemicaleffectstestingandevaluationanddownstreameffectsanalyses.ByletterdatedJuly1,2008,theNRCapprovedtheextensionrequest.

RequestforExtensionforNorthAnnaUnits1and2andSurryUnits1and2 Significantprogresshasbeenmadetocompletetheremainingchemicaleffectstestingandevaluationandthedownstreamcomponentwear,systemperformance,andpumpsealevaluations.Asfurtherdiscussedbelow,thecompletedchemicaleffectsevaluationsforNorthAnnaandSurryhaveconcludedthatthequantityofaluminumincontainmentthatissubjecttosprayorsubmergenceduringadesignbasisaccidentmustbereducedtoensurepropercontainmentsumpperformance.Inaddition,furtheranalysisofHighHeadSafetyInjection(HHSI) pump wearandseal performanceisrequiredto determineamorerealisticevaluationofpump performanceunderexpected post-accident conditions.

Serial No.08-0541DocketNos.

50-338/339/280/281GL2004-02;RequestforExtensionsPage2of5*ChemicalEffectsTesting/EvaluationResults-DominionhascompletedchemicaleffectstestingandevaluationsforNorthAnnaandSurryUnits1and2.Thetestresultsindicatethataluminumremediationbyencapsulation,removaland/orrelocationisrequiredfortheSurryUnit1andNorthAnnaUnits1and2containmentstoensurethatthecontainmentsumpstrainerscaneffectivelyperformtheirdesignfunctioninapost-accidentenvironment.TherequiredaluminumreductionforSurryUnit1consistsofeitherremovingorprotectinganaluminumstorageboxincontainment.ThealuminumremediationeffortrequiredforNorthAnnaUnits1and2isconsiderablymoreextensivethanSurry.Severalactivitiesareunderwaytodecreasetheamountofaluminumincontainmentthatissubjecttocorrosionincluding:1)thedeterminationofthenumberofcontrolroddrivemechanisms(CRDM)andreactorprotectioninstrumentation(RPI)connectorsthataresubjecttospray,2)theimplementationofprocedurechangestoensurethattheCRDMfansarenotrestartedwhentheQuenchSprayand/or Recirculation Spray(RS)systemsareinoperation,and3)theencapsulation,removal,and/orrelocationofaluminumladderstoeliminatethechemicaleffectsofthecontainmentsprays.TheseactivitieswillbecompletedbythecurrentSeptember30,2008extensiondateforSurryUnit1andNorthAnnaUnit1andpriortorestartofNorthAnnaUnit2afterenteringamidSeptember2008refuelingoutage.*DownstreamEffectsAnalysisResults(PumpWearandSealPerformance)Thedownstreameffects evaluationsthatwere performedfortheRSsystemandtheEmergencyCoreCoolingSystem(ECCS)pumpshaveconcludedthattheRSandLowHeadSafety Injection(LHSI)pumps'wearandsealperformanceareexpectedtobe acceptable for post-accident sump conditions.

However, theinitialevaluations performedforHHSIpumpwearandsealperformance indicated that additional analysisusingmore realistic, yet conservative, operatingconditionsis requiredtoconfirmproperpump performanceunderexpectedaccidentoperating conditions.

This confirmatoryanalysisisongoingbytheoriginalpumpmanufacturerandfavorableresultsare expected.However, theSurryandNorthAnna evaluationswillnotbe completed, reviewedandaccepteduntilOctober31,2008.

• LicensingandDesignBasis DocumentationUpdate-DuetotheneedforanextensiontocompletetheHHSIpumpwearandsealevaluationsforSurryandNorthAnnaUnits1and2, additionaltimeisalso requiredtocompletethenecessarydesignand licensing bases documentationupdatesuponcompletionofthese activities.Therefore,basedonthe information discussed above,anextensionis requested toNovember30,2008forSurryandNorthAnnaUnits1and2.The remaining Serial No.08-0541 Docket Nos.50-338/339/280/281 GL 2004-02;Request for ExtensionsPage3of5milestonesforthe completionofGL2004-02 correctiveactionsforSurryandNorthAnnaunitsare providedinthe attachment.BasisfortheExtension RequestThisextensionrequestissupportedbythepreviousextensionrequestbasesincludedinDominion'sNovember15,2007letter,asupdatedbytheMay21,2008letter,whichaddressedthethreecriteriacontainedinSECY-06-0078datedMarch31,2006,"CriteriaforEvaluatingDelayofHardwareChanges,"andtheapplicableelementsoftheNRCjustificationforcontinuedoperationinthe"SummaryofJuly26-27,2001MeetingwithNuclearEnergyInstituteandIndustryonECCSStrainerBlockageinPWRs,"datedAugust14,2001foreachplant.ThebasesincludedintheNovember15,2007andMay21,2008letters,remainvalidandapplicableforthisextensionrequestandcontinuetoconfirmthatNorthAnnaandSurryUnits1and2willcontinuetomeettheircurrentplantlicensingbasesregardingthefunctionandoperabilityofthecontainmentsumpsduringtheperiodoftherequestedextensionsinthat:*Theplantshavecompletedconsiderablephysicalmodificationsandanalyticalactivities,includingreplacingtheECCSandRSstrainers,toensureahighdegreeofEmergencyCoreCoolingSystem(ECCS)andRecirculationSpray(RS)System(asapplicable)performance,*TheplantshaveimplementedmitigativemeasurestominimizetheriskofdegradedECCSandRS(asapplicable)functionsduringtheextensionperiod,and*Theplantshaveplant-specificplanswithmilestonesandschedulestoaddresstheoutstandingtechnicalissueswithsufficientconservatismtoaddressuncertainties(seeattachment).

Furthermore,ariskassessment associatedwiththe extensionforthecompletionoftheSurryandNorthAnnaUnits1and2GL2004-02correctiveactionswaspreviouslyperformedandwasalsoprovidedinourNovember15,2007letter.Theriskassessmentdeterminedthattheriskwas"small"foranextensionofcorrectiveactioncompletionuntilNovember30,2008andremainsvalidfortheSurryandNorthAnnaextensionrequeststoNovember30,2008containedhereinaswell.Therefore,DominionhasestablishedthatthereisreasonableassuranceduringtherequestedextensionperiodthatNorthAnnaUnits1and2andSurryUnits1and2willprovideacceptablestrainerfunctionwithadequatemarginforuncertainties,aspreviouslyconfirmedintheNRC'sJuly 1,2008 letter.

Serial No.08-0541 Docket Nos.50-338/339/280/281GL2004-02; Request for ExtensionsPage4of5Ifyouhaveany questionsorrequire additional information, please contact Mr.Gary D.Millerat(804)273-2771.Sincerely, cc>""""<0.-..:)W.R.Matthews Senior Vice President-Nuclear Operations AttachmentGL2004-02ProjectMilestoneSchedules Commitmentsmadeinthis correspondence:

1.This letter containsnonew commitments.

Completion dates are changed for regulatory commitments previously associatedwithGL 2004-02.COMMONWEALTH OF VIRGINIA))COUNTY OF HENRICO)The foregoing document was acknowledged beforeme,inand for the County and Commonwealth aforesaid, today by William R.Matthews,whois Senior Vice President-Nuclear Operations of Virginia Electric and Power Company.Hehas affirmed beforemethatheisduly authorized to executeandfilethe foregoing document in behalf of thatcompany,andthatthe statementsinthe document aretruetothebestofhis knowledgeandbelief.

Acknowledged beforemethis 5 1/1dayof ,2008.My Commission Expires:.&g..3<dmoNotaryPublic cc:U.S.Nuclear Regulatory CommissionRegionIISamNunn Atlanta Federal Center61ForsythStreet,SWSuite23T85Atlanta,Georgia30303 NRC Senior Resident InspectorNorthAnnaPowerStation NRC Senior Resident Inspector Surry Power StationMr.S.P.Lingam NRC Project ManagerU.S.Nuclear Regulatory Commission One WhiteFlintNorthMailStop8G9A11555RockvillePikeRockville,Maryland20852Mr.J.F.Stang,Jr.

NRC Project ManagerU.S.Nuclear Regulatory Commission One WhiteFlintNorthMailStop8G9A11555RockvillePikeRockville,Maryland20852Ms.D.N.Wright NRC Project ManagerU.S.Nuclear Regulatory Commission One WhiteFlintNorthMailStop8H4A11555RockvillePikeRockville,Maryland20852SerialNo.08-0541DocketNos.

50-338/339/280/281GL2004-02; Request for Extensions Page 5 of 5 Serial No.08-0541DocketNos.

50-338/339/280/281GL2004-02;RequestforExtensions ATTACHMENT GL 2004-02 Project Milestone SchedulesVirginiaElectricand Power Company (Dominion)NorthAnnaandSurry PowerStationsUnits1and2 SerialNo.08-0541 Docket Nos.50-338/339/280/281GL2004-02; Request for Extensions Attachment Page 1of2 NORTH ANNA UNITS1AND2 MILESTONE SCHEDULE UNIT 1&21&2HHSIPumpSealEvaluation1ReduceAluminumInventoryin Containment2ReduceAluminumInventoryin Containment GSI-191 De1&2FieldChangeUnit2ContainmentSumpStrainerDesignChangePackage1&2Updatedocumentationforcompletecompliancewith GSI-191 10/31/08 09/30/08 10/15/08*"Priortorestartfromrefuelingoutage.

tion 11/15/08 11/30/08 Serial No.08-0541DocketNos.

50-338/339/280/281GL2004-02; Request for Extensions Attachment Page 2 of2 SURRYUNITS1AND2 MILESTONE SCHEDULE 1&2 1&2 1ObtainNRCApprovalofLARtodeleteobsoleteRSsystemminimumflowvalue 09/301081&2IncorporateapprovedLARintoLicensingandDesignBases1&2FieldChangeUnit1ContainmentSump StrainerDesignChangePackage1&2UpdatedocumentationforcompletecompliancewithGSI-191 10/22/08 11/15/08 11/30108