ML102020020

07/13/2010-Summary of Public Meeting with Oconee, to Discuss Safety Significance of Two Preliminary Greater than Green Findings with Two Associated Apparent Violations and Severity Level of One AV Considered for Potential Escalated Enforcem

ML102020020
Person / Time
Site:	Oconee
Issue date:	07/20/2010
From:	Bartley J NRC/RGN-II/DRP/RPB1
To:	Baxter D Duke Energy Carolinas
References
Download: ML102020020 (66)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION REGION II 245 PEACHTREE CENTER AVENUE NE, SUITE 1200 ATLANTA, GEORGIA 30303-1257 July 20, 2010

Mr. David A. Baxter Site Vice President Duke Energy Carolinas, LLC Oconee Nuclear Station 7800 Rochester Highway Seneca, SC 29672

SUBJECT:

PUBLIC MEETING

SUMMARY

- OCONEE NUCLEAR STATION - DOCKET NOS. 50-269, 50-270, AND 50-287

Dear Mr. Baxter:

This refers to the Category 1 public meeting which was held on July 13, 2010, in Atlanta, GA. The purpose of this meeting was to discuss the safety significance of two preliminary greater than Green findings with two associated Apparent Violations (AV) and the severity level of one AV considered for potential Escalated Enforcement that were documented in NRC Inspection Report 05000269,05000270,05000287/2010007. A listing of meeting attendees and information presented during the meeting are enclosed.

In accordance with 10 CFR 2.390 of the NRC's "Rules of Practice," a copy of this letter will be available electronically for public inspection in the NRC Public Document Room (PDR) or from the Publicly Available Records (PARS) component of NRC's document system (ADAMS).

ADAMS is accessible from the NRC Web site at http://www.nrc.gov/reading-rm/adams.html (the Public Electronic Reading Room).

Should you have any questions concerning this meeting, please contact me at (404) 997-4607.

Sincerely,

/RA/

Jonathan H. Bartley, Chief Reactor Projects Branch 1 Division of Reactor Projects Docket Nos.: 50-269, 50-270, 50-287 License Nos.: DPR-38, DPR-47, DPR-55

Enclosures:

1. List of Attendees

2. Summary of Violations

3. Duke Energy Carolinas Presentation

cc w/encls: (See page 2)

_________________________

G SUNSI REVIEW COMPLETE OFFICE RII:DRP RII:DRP SIGNATURE JHB /RA for/ JHB /RA/ NAME EStamm JBartley DATE 7/ /2010 7/ /2010 7/ /2010 7/ /2010 7/ /2010 7/ /2010 7/ /2010 E-MAIL COPY? YES NO YES NO YES NO YES NO YES NO YES NO YES NO DEC 2 cc w/encl:

David A. Baxter Site Vice President Oconee Nuclear Station Duke Energy Carolinas, LLC Electronic Mail Distribution Kent Alter Regulatory Compliance Manager Oconee Nuclear Station Duke Energy Carolinas, LLC Electronic Mail Distribution J. W. (Bill) Pitesa Senior Vice President Nuclear Operations Duke Energy Carolinas, LLC Electronic Mail Distribution Scott L. Batson Engineering Manager Oconee Nuclear Station Duke Energy Carolinas, LLC Electronic Mail Distribution Philip J. Culbertson Oconee Nuclear Station Duke Energy Carolinas, LLC Electronic Mail Distribution Preston Gillespie Station Manager Oconee Nuclear Station Duke Energy Carolinas, LLC Electronic Mail Distribution

R. L. Gill, Jr. Manager Nuclear Regulatory Issues & Industry Affairs Duke Energy Carolinas, LLC Electronic Mail Distribution Dhiaa M. Jamil Group Executive and Chief Nuclear Officer Duke Energy Carolinas, LLC Electronic Mail Distribution David A. Repka Winston Strawn LLP Electronic Mail Distribution Kathryn B. Nolan Senior Counsel Duke Energy Corporation 526 South Church Street-EC07H Charlotte, NC 28202 Charles Brinkman Director Washington Operations Westinghouse Electric Company, LLC Electronic Mail Distribution County Supervisor of Oconee County 415 S. Pine Street Walhalla, SC 29691-2145

Mark Yeager Division of Radioactive Waste Mgmt. S.C. Department of Health and Environmental Control Electronic Mail Distribution

Lara Nichols Associate General Counsel Duke Energy Corporation Electronic Mail Distribution

Susan E. Jenkins Director, Division of Waste Management Bureau of Land and Waste Management S.C. Department of Health and Environmental Control Electronic Mail Distribution W. Lee Cox, III Section Chief Radiation Protection Section N.C. Department of Environmental Commerce & Natural Resources Electronic Mail Distribution Jim Kammer RES Manager Duke Energy Carolinas, LLC Electronic Mail Distribution Paul Fisk MCE Manager Duke Energy Carolinas, LLC Electronic Mail Distribution TVA 3 Letter to David A. Baxter from Jonathan H. Bartley dated July 20, 2010

SUBJECT:

OCONEE NUCLEAR STATION - NRC INTEGRATED INSPECTION REPORT 05000269/2010, 05000270/2010 AND 05000287/2010 Distribution w/encl:

C. Evans, RII EICS (Part 72 Only) L. Slack, RII EICS (Linda Slack) OE Mail (email address if applicable)

RIDSNRRDIRS PUBLIC RidsNrrPMOconee Resource

Enclosure 1

2 Enclosure 1

Enclosure 2 OCONEE REGULATORY AND PREDECISIONAL ENFORCEMENT CONFERENCEJuly 13, 2010[SSF Letdown Filter]

2 Enclosure 2 Apparent Violation #110 CFR 50, Appendix B, Criterion XVI, Corrective Action, requires, in part, that measures shall be established to assure that conditions adverse to quality, such as failures, deficiencies, and defective material are promptly identified and corrected. Contrary to the above, from October 19, 2009, to February 20, 2010, (Unit 2) and February 23, 2010, (Unit 3) the licensee failed to promptly identify and correct a condition adverse to quality involving foreign material on the Unit 2 and 3 SSF letdown line filters. In this case, after identification of a condition adverse to quality on Unit 1, the licensee failed to identify and correct a similar condition adverse to quality on Unit 2 and Unit 3. The condition would have adversely affected the operator's ability to control reactor coolant system inventory during a postulated event involving the use of the Standby Shutdown Facility.

3 Enclosure 2 Apparent Violation #2Technical Specification 3.10.1 required the SSF to be operable in Modes 1, 2 and 3 and Condition C allowed the RCM subsystem to be inoperable for up to seven days without additional actions being taken. Contrary to the above, the SSF RCM system was inoperable whenever the unit was in Modes 1, 2, or 3 from May 30, 2008, until October 9, 2009, for Unit 1; from December 10, 2008, until February 20, 2010, for Unit 2; and from May 19, 2009, until February 23, 2010, for Unit 3 because the letdown line could not pass the required flow.

4 Enclosure 2 Apparent Violation #310 CFR 50.9(a) requires, in part, that information provided to the Commission by a licensee shall be complete and accurate in all material respects. Contrary to the above, on December 18, 2009, the licensee provided information to the NRC that was not complete and accurate in all material respects. The information provided described compensatory actions for controlling pressurizer level during an SSF event which was not available due to a closed manual valve inside containment. This information, combined with an evaluation that showed flow rates on Unit 2 and Unit 3 were greater than the required value for level control in the last as-tested condition, was material to the NRC because it was used, in part, as the basis for determining whether the licensee's response to the degraded condition was adequate and whether additional compensatory actions or NRC review would be necessary.

Enclosure 3 OCONEE REGULATORY AND PREDECISIONAL ENFORCEMENT CONFERENCEJuly 13, 2010[SSF Letdown Filter]

2 Enclosure 3 1Foreign Material Found in the Standby Shutdown Facility (SSF) Letdown Line Strainer for Units 1, 2, and 3NRC Region II OfficeAtlanta, GeorgiaJuly 13, 2010Oconee Nuclear StationRegulatory Conference

3 Enclosure 3 2Duke ParticipantsBill Pitesa, Senior Vice President, Nuclear OperationsDave Baxter,Oconee Site Vice PresidentPreston Gillespie, Oconee Station ManagerScott Batson,Oconee Engineering ManagerJim Kammer,Oconee RES Engineering ManagerPaul Fisk,Oconee MCE Engineering ManagerSteve Nader,NGO PRA Engineering SupervisorChris Nolan,NGO Licensing Manager

4 Enclosure 3 3 AgendaOpening RemarksD. BaxterSSF Letdown Line OverviewS. BatsonTimelineJ. KammerTesting OverviewP. FiskSDP Highlights and ResultsS. NaderRegulatory PerspectivesC. NolanCause Analysis and Corrective ActionsP. Fisk / Jim KammerClosing RemarksD. Baxter / B. Pitesa

5 Enclosure 3 4Opening RemarksThe SSF performs an important safety function with a high risk worthNRC staff played a key role in recognizing the common mode vulnerability of this issueOconee will present its cause analysis and corrective actionsOconee will present insights from its fire PRA which was submitted to NRC for Oconee's NFPA 805 amendment requestOconee agrees with NRC's characterization:Apparent violation of 10 CFR 50.9Apparent violation of Appendix B, Criteria XVIApparent violation of Technical Specifications

6 Enclosure 3 5Opening Remarks -cont.NRC proposed two findings to address letdown line degradation:A current performance issue that is forward looking from discoveryA legacy issuewith the original design that is a look backOconee proposes a combined performance deficiency to address both perspectives reflective of this single eventFailure to promptly identify and correct a degraded condition in the SSF RCM letdown line for Units 1, 2, & 3Aligns regulatory focus, significance, and inspectionThe maximum exposure time would be applied to each unit (1 year)Avoids the appearance of double counting

7 Enclosure 3 SSF Letdown Line Overview 6Scott Batson,Engineer Manager,Oconee Nuclear Station

8 Enclosure 3 SSF Letdown Line Overview:System Flow Diagram 7

9 Enclosure 3 8SSF Letdown Line Overview:TimelineSSF RC Letdown Line Orifice Strainer history~ 1982:Original installation of letdown line orifice / strainer~ 1994/95:Orifice determined to be under-sized; new orifice installed~ 1996/97:Flow test performed on all units, passedRecent testing of SSF RC Letdown Line02/2007:Unit 3 RBES legacy foreign material finding10/2008:Unit 2 SSF RC letdown line flow test passed04/2009:Unit 3 SSF RC letdown line flow test passed10/2009:Unit 1 SSF RC letdown line flow test failed, root cause evaluation conducted, strainer removed correcting condition

10 Enclosure 3 SSF Letdown Line Overview:Cause AnalysisOconee approach to cause analysisFleet approachEach site reviews other site root causes and corrective actions to prevent recurrence; expectation is fleet consistency for these actionsNuclear System & other lower tier directives apply fleet wide 9IssueCause AnalysisInaccurate material information provided to NRCPIP 10-0561 Apparent Cause Analysis completed 3/24/10SSF RCLetdown Line inoperable due to foreign material09-7536 Root Cause AnalysisRev. 0 completed 12/03/09Rev. 1 completed 04/8/10Inadequate correctiveactions from October2009 to 23 February 201010-1213 Root Cause Analysis Includes additional organizational &

programmatic issues related to inaccurate material information provided to NRC 11 Enclosure 3 Timeline 10Jim Kammer,Reactor & Electrical Systems Engineer Manager 12 Enclosure 3 Timeline02/13/07:RBES White Finding06/27/08:Decision to use SSF letdown line flow path verification test method to address RBES White Finding10/11/09:Unit 1 flow test was performed and failed10/19/09:Debris found in orifice strainer 10/23/091HP-426 disassembled, backseat gasket missing10/27/09:Archived data used to generate flow information from prior tests and compared to expected results10/27/09:Flowserve indicated no previous reports of problems with backseat gasket or material 11 13 Enclosure 3 Timeline11/10/09:Three spare valves examined and backseat gaskets found in place11/20/09:ONS concluded that the performance issue was isolated to Unit 111/23/09:Strainer proof of concept/methodology performed using a positive displacement pump -strainer deformation observed12/03/09:Site CARB approves Root Cause Rev 0 (09-7536)12/18/09: Additional analyses re-affirmed adequate flow for Units 2 and 3 and recognized Unit 2 had less margin than originally estimated 12 14 Enclosure 3 Timeline~ 01/18/10:Regulatory Impact Team reviewed flow analysis and questioned the reduced margin for Unit 2 and the lack of a PIP01/25/10:PIP 10-0494 written documenting less margin than expected on Unit 201/25/10:Operations concurred with Immediate Determination of Operability (Re-affirmed 2/8/10)02/17/10:Operations concurred with Prompt Determination of Operability 02/18/10: NRC asks Operations questions related to operability including: Could strainer deform under expected dP, and what would be the impact on flow?

13 15 Enclosure 3 Timeline02/18/10:Operations requests Engineering assistance to address NRC questions02/18/10:Unit 2 SSF Letdown Line declared Inoperable02/20/10:Unit 2 power reduced to 20% to remove the SSF LD line orifice strainer02/21/10:PIP 10-1203 written to assess impact on Unit 3 of new data from Unit 202/23/10:Unit 3 power reduced to 20% to remove the SSF LD line orifice strainer03/10 -05/10:Offsite testing conducted at Alden Research Laboratory, Inc.

14 16 Enclosure 3 Testing Overview 15Paul Fisk,Mechanical & Civil SystemsEngineer Manager

17 Enclosure 3 Testing Overview: Problem IdentificationUnit 1 blockage detected while performing flow test to address Unit 3 RBES Foreign Material corrective actions (October 2009) RCS conditions held stable in Mode 5 Flow established from HPI Letdown, through 1HP-426 and pressure reduction orifice, to Spent Fuel Pool Acceptance criteria: 3 inch decrease in Pressurizer level in 15 minutesUnit 2 and Unit 3 tested (Fall 2008 / Spring 2009) Unit 1 result was no appreciable Pressurizer level change 16 18 Enclosure 3 Testing Overview: Problem IdentificationSubsequent inspection found debris in pipe and orifice strainer screen downstream of valve, 1HP-426Debris identified by Met Lab as mixture of "legacy" and graphite materials 17Top ViewUnit 1 orifice strainerSide ViewUnit 1 orifice strainer

19 Enclosure 3 Testing Overview: Problem IdentificationGraphite material found to be from upstream valve, 1HP-426Valve backseat insert gasket ("Grafoil") had become dislodged and flowed to strainer 181HP-426 valve internalsBackseat GasketCross-section Sketch

20 Enclosure 3 Testing Overview: Problem IdentificationSimilar failure mode subsequently identified in Unit 2 and Unit 3 systems 19Unit 1 MaterialUnit 2 MaterialUnit 3 MaterialLargerGrafoilStrips & Shreds~20 mils thick by 1/8-inch wide and up to 1/2-inch in lengthGrafoilMaterialMost of the Grafoil particles consisted of very fine flakesGrafoilMaterialFivepieces up to 0.3-inchDiscrete,irregular chunks of plastic material (epoxy)Alumina AbrasivePaint ChipsFiner mixed particulate consisting of above materials and fine metal shavingsStainless Steel ShavingsRust FlakesFine FibersMixture of Very Fine Particulate

21 Enclosure 3 Testing Overview: Offsite TestingUsed to determine flow rates at full system pressure for as-found conditionsResulted in the following significant observations:Grafoil material in the amount of one gasket is sufficient to deform the strainer and reduce flow less than acceptance criteriaStrainer deformation does not result in complete flow blockageLegacy material only slightly reduces flow (meets acceptance criteria)Strainer deformation does not occur under legacy material loadingWith entire Grafoil backseat gasket captured by orifice strainer.Strainer deformation expected with flow reduction, not complete blockageFlow reduction not adequate to perform design function.Design function would be satisfied with legacy material alone (i.e. -no Grafoil)20 22 Enclosure 3 SDP Highlights and Results 21Steve Nader,NGO PRA Engineering Supervisor

23 Enclosure 3 SDP Highlights:NRC Risk SignificanceNRC's June 9, 2010, letter provided lower bound for riskRisk analyses associated with fire are not finalizedOconee aligns with NRC's assessment in the following areas:Overall approachInternal Events riskHELB riskInternal Flood riskSeismic riskTornado riskOperator Action 22 24 Enclosure 3 23SDP Highlights:Fire Modeling and NFPA 805Fire Risk -still under developmentOn-going discussions between Oconee and NRC PRA expertsFire risk will likely drive final significance determinationObjective of SDP is to achieve a "best estimate" assessment of riskTherefore, fire risk should be a "best estimate" valueOconee is a pilot for NFPA 805 (LAR submitted 4/14/10)We have a detailed Fire PRA modelGood tool to evaluate this kind of scenarioHowever, pilot experience has shown that NUREG 6850 does not provide "best estimate" results

25 Enclosure 3 24 SDP Highlights:Fire Model BackgroundNUREG 6850 provides fire frequenciesPilots (Oconee, Harris) saw the need to develop refinementsDeviations were peer reviewedOther industry efforts also underway to refine NUREG 6850EPRI published TR-1016735 (NRC approved limited use per FAQ 08-048)PWROG working on improving details of past fire events to allow more accurate estimation of fire frequenciesNEI has presented information showing NUREG 6850 results in over estimation of fires in low voltage electrical cabinets by 10x compared to actual operating experienceACRS has recommended refinement of NUREG 6850

26 Enclosure 3 25 SDP Highlights:Key Fire Model InputsLow Voltage Electrical CabinetsCabinets could have a fire that propagates to adjacent cables resulting in loss of redundant functions -SBONUREG 6850 methodology Does not differentiate between high and low voltage cabinetsAssumes most multi-cable bundle cabinet fires propagate to low (3' to 4') overhead cables; not conducive to scenario refinement Per NEI, this methodology predicts the industry should have had ~ 130 severe fires in these types of cabinetsOnly 13 in the industry data baseOconee approachDifferent treatment for low and high voltagecabinetsDifferent treatment for sealed vs. ventilated cabinets

27 Enclosure 3 SDP Highlights:Key Fire Model InputsElectrical Cabinet Fires (Oconee approach -con't)Sealed CabinetsWell sealed cabinets do not propagatePoorly ventilated (leaky) cabinets exhibit similar fire behaviorInternal cabinet failures include concurrent spurious Ventilated CabinetsSeverity Factor appliedNUREG 6850 heat release rate (HRR) distribution profiles used for a broad range of applications (load centers, switchgear, etc.)Oconee applied an empirically based factor for low voltage cabinets 26 28 Enclosure 3 27 SDP Highlights:Key Fire Model InputsCabinets with wirewaysAdjacent cabinets with wirewaysin the walls to allow cables to pass between cabinetsOconee's best estimate approach assumes fires do not propagate between cabinets nor to adjacent equipmentBased on limited openings, and therefore limited oxygen sourceNo PVC material inside cabinet to challenge penetrations If propagation is assumed ("severe" fires)FAQ on "super cabinets" provides an alternate way to count the cabinets and apply the proper fire frequencyTiming should be considered, credit for fire brigade

29 Enclosure 3 28 SDP Highlights:Key Fire Model InputsBus Ducts:NUREG 6850 methodology has been a topic of industry discussionEPRI has calculated new frequencies (older data receives less weight) One plant experienced 3 of the 7 eventsShould be plant specific (Bayesian update)Duke's opinion is that:Oconee bus ducts are robustThickness of enclosure offers better containment relative to sheet metalCircular construction provides better protectionArmored cables are less vulnerable targets(galvanized steel)

30 Enclosure 3 29 SDP Highlights:Key Fire Model InputsLoss of Normal Letdown ScenariosFire could cause a loss of normal letdown and the auto-alignment to BWSTCould result in the loss of key safety pumps (no suction path)Oconee emergency procedures provide multiple optionsRefill Letdown Storage Tank, orAlign Low Pressure pumps to BWST and use piggy back modeBoth of these strategies ensure a continuous suction path

31 Enclosure 3 SDP Results:Treatment of Event Exposure TimeRisk results are calculated on a per year basisAdjusted to match actual event durationCurrent risk analysisUnit 1:12 monthsUnits 2/3: 12 months+ ~4 monthsProposedUnits 1/2/3: 12 months 30 32 Enclosure 3 SDP Results:ConclusionsSDP Risk SignificanceTotal delta CDF ~ 8.0E-06/yr [Draft] (based on one year duration)NUREG/CR-6850 does not provide "best estimate" results for this applicationObservations regarding NRC's proposed actionUnits 2 & 3 assessed 16 months of cumulative exposure time 31 33 Enclosure 3 Regulatory Perspectives 32Chris Nolan,NGO Licensing Manager

34 Enclosure 3 Regulatory Perspectives:Apparent Violation of 10 CFR 50.9Oconee's action plan for the SSF letdown line issue was provided to NRC on 12/18/2009 Identified Oconee's intention to remove the Unit 2 and Unit 3 orifice strainers in the event of a forced outage to Mode 3Identified three alternate methods to provide pressurizer level control including:TSC directed action to utilize reactor coolant makeup pump (RCMUP) bypass lineFlow path could be initiated within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> A closed manual valve inside containment precluded the use of this flow path 33 35 Enclosure 3 Regulatory Perspectives:Apparent Violation of 10 CFR 50.912/18/09:Action Plan White Paper provided to NRC01/27/10:Manual valve (2,3 HP-427) discovered closedDiscovered during engineering change process updating design basis documents for this event01/27/10:Immediately entered into corrective action program01/27/10:The NRC SRI was informed01/28/10:Containment entry made to open 2 HP-42701/29/10:Containment entry made to open 3 HP-42701/29/10: Compliance was restored02/09/10:Prompt corrective actions completed 34 36 Enclosure 3 Regulatory Perspectives:Apparent Violation of 10 CFR 50.9NSD-227, "Communicating with the NRC" was not followedNSD-227 is robust and the validation process required in NSD-227, if followed correctly, would have identified the inconsistencyCorrective ActionsAccountability for administrative procedure compliance reinforcedReinforcement of expectations regarding communications with NRCCompliance Manager written expectations to Regulatory Compliance Group on NSD 227SA Manager conducted table top session with Regulatory Compliance Group Engineering continuing training lessons learnedCatawba/McGuire Regulatory Compliance Group lessons learnedFleet wide communication by Senior VP 35 37 Enclosure 3 Regulatory Perspectives:Apparent Violation of 10 CFR 50.9Oconee agrees with the apparent violation (AV)No aspects of willfulness were identified with the AVNo traditional escalated enforcement activity within two yearsOconee identified the violation and promptly informed the NRCPrompt & comprehensive corrective actions have been takenOconee acknowledges that this violation could be assessed as a Severity Level IIIBased on our review of the Enforcement Policy, Oconee does not believe that a civil penalty is warranted 36 38 Enclosure 3 Regulatory Perspectives:Current Performance IssueExpectations were not met regarding Oconee's response to SSF letdown line degradationApparent Violation of Appendix B, Criterion XVIOconee agrees with the performance deficiency for Units 2 & 3This issue was reflective of current performance and foreseeable This issue has a low to moderate risk significanceOconee agrees with the cross-cutting aspect of H.1(b)Oconee agrees with the apparent violationCorrective actions taken to restore complianceComprehensive actions taken or planned to address extent of condition 37 39 Enclosure 3 Regulatory Perspectives:Legacy IssueApparent Violation of TS 3.10.1Oconee agrees with the violationCorrective actions taken to restore complianceComprehensive actions taken or planned for extent-of-conditionSignificanceThis issue has a low to moderate risk significanceOconee has offered its risk insights regarding the PRA analysis:Treatment of low voltage cabinet firesTreatment of bus ductsEvent exposure timeThis issue is not reflective of current performance 38 40 Enclosure 3 Regulatory Perspectives:Legacy IssueSingle performance deficiency to address the event: Failure to promptly identify and correct a degraded condition for the Unit 1, 2, & 3 SSF RCMU letdown lineValid performance deficiency that was reasonably foreseeableUntimely recognition of a new degradation mechanism as a common mode failureMissed opportunities to identify in 2008 & 2009Addresses testing weaknesses in context of current performanceCharacterizes the significance of the event and applies that significance to all three units (1year of exposure time)Apparent violations of Criterion XVI and TS 3.10.1 would apply 39 41 Enclosure 3 Regulatory Perspectives:Legacy IssuesChallenges with the Legacy Performance DeficiencyNo regulatory requirement or licensee standard to test the lineThis issue is not reflective of current performanceTesting was a corrective action related to RBES FMThe letdown line failure was not reasonably foreseeableA new degradation mechanism impacted performance

• Deteriorating backseat gasket in combination with fine mesh strainer

• Vendor was not aware of mechanism (10 CFR 21 notification)

• Oconee shared operating experience with other utilitiesNon-Grafoilmaterial insufficient to reduce flow below acceptable levelsLegacy issue should not be considered a valid performance deficiency 40 42 Enclosure 3 Regulatory Perspectives:SummaryOconee propose a single performance deficiency to address RCMU letdown line flow degradation:The finding would apply to all three unitsIssue characterized with a low to moderate risk significanceThe maximum exposure time of 1 year would applyApparent violations of Criterion XVI and TS 3.10.1 would apply Aligns the regulatory focus, significance, corrective actions, and inspection outcomesAvoids the appearance of double countingOconee plans to test the SSF letdown line on a refueling outage basis going forward 41 43 Enclosure 3 Cause Analysis & Corrective Actions Legacy Issue 42Paul Fisk,Mechanical & Civil SystemsEngineer Manager

44 Enclosure 3 Legacy Issue: Cause DeterminationInitial root cause completed on 12/03/09Root cause identified as valve vendor assembly errorImmediate corrective actions removed 1HP-426 backseat gasket and Unit 1 orifice strainerStrainer removal and flow testing work orders written for Unit 2 and Unit 3 and added to forced outage listsRoot cause reopened based on new information from Unit 2 & 3 strainer removal / inspectionsProblem statement redefined as flow blockage on U1 and flow reduction on U2Scope expanded to include deeper look at O&P factorsExtent of condition expanded beyond SSF subsystemsExtent of cause examined for all causes (root and contributing) 43 45 Enclosure 3 Legacy Issue: Cause DeterminationRoot Cause (from Revision 1, completed 4/8/10)Improper strainer selectionContributing Causes Inadequate testingUntimely and ineffective Unit 3 Emergency Sump foreign material corrective actionsInadequate design documentationValve manufacturing deficiency Legacy foreign material 44 46 Enclosure 3 Legacy Issue:Corrective Actions -CompletedStrainers removed from all units as of 2/24/10, resulting in full compliance with Tech Spec 3.10.1Rigorous testing establishedExtent of condition evaluated for all plant valves with similar backseat gasket design SSF test matrices evaluated for weaknesses in light of lessons learned 45 47 Enclosure 3 Legacy Issue:Corrective Actions -CompletedSolicited independent industry expert to evaluate effectiveness of root cause analysis and corrective actionsOverall conclusion was a rigorous, detailed and thorough cause analysisImprovement recommendations captured in corrective action programReviewed outstanding U3 RBES event corrective actions for riskProvided lessons-learned training to Engineering organizationCommunicated to all site personnel involved in design changes and establishing test acceptance criteria 46 48 Enclosure 3 Legacy Issue:Corrective Actions -PlannedIndependent, non-ONS team to review adequacy of current SSF testingReview and validate the adequacy of test matrix and test acceptance criteria for all MR high safety significant functionsRevise directives related to testing 47 49 Enclosure 3 Cause Analysis & Corrective ActionsCurrent Performance Issue 48Jim Kammer,Reactor & Electrical Systems Engineer Manager 50 Enclosure 3 Current Performance Issue:Cause AnalysisOconee Root Cause Methodology Independent Contractor brought in to apply MORT methodologyStatus: Comment resolution in progress 49 51 Enclosure 3 Current Performance Issue:Key InsightsDecision MakingFailed to ensure selected test method was adequate to provide the desired information.Failed to validate quality (precision) of informationCorrective Action ProgramFailed to initiate new PIPs when significant new information was receivedFailed to adequately assess potential failure modes of equipment during Operability Determination Process.Identified weaknesses in issue managementInadequate oversight Inadequate communicationsInadequate transition from outage emergent issue to other process 50 52 Enclosure 3 Current Performance Issue: Corrective ActionsDecision MakingAccountability reinforcementEngineering Continuing TrainingFleet communication on issue from Senior VPNow require Management Review Team process for each Prompt Determination of Operability Evaluate process changes to require Management Review Team for Prompt Determinations of Operability (Fleet)Leadership Academy training on decision-making 51 53 Enclosure 3 Current Performance Issue: Corrective ActionsCorrective Action ProgramAccountability reinforcementEnhance guidance for new PIP threshold when already working within PIPEnhance Cause Analysis Process to identify situations that will require a formal FMEACorrective Action Review Board TrainingLessons LearnedRoot CauseOperabilityExtent of Condition/Extent of Cause 52 54 Enclosure 3 Current Performance Issue: Corrective ActionsIssue Management Accountability reinforcementProcess enhancementsEnhance issue management roles and responsibilities for the management lead in the areas of providing oversight, clear communications, coordination of hand-offs between processes.Establish clear expectations for communications frequency and content with a focus on new information and its potential relationships to the issue under investigation.Establish clear hand-off from outage emergent issue to other oversight process. Fleet communication on issue from Senior VP 53 55 Enclosure 3 Closing Remarks 54Dave Baxter,Site Vice PresidentBill Pitesa,Senior Vice President, Nuclear Operations

56 Enclosure 3 55Closing RemarksOconee's performance did not meet expectationsOconee has described its cause analysis and corrective actionsOconee agrees with the apparent violations of 10 CFR 50.9, Appendix B Criterion XVI, and TS 3.10.1 proposed by NRCOconee has offered its perspectives regarding riskProposal to combine performance deficiencies to reflect the legacy and current performance perspectives of a single event Focuses on current performance issues that were foreseeable Aligns regulatory focus, significance, corrective actions, and inspection outcomesEqual treatment of units impacted by a common mode failure Avoids the appearance of double counting