ML14035A094

2/4/2014 Waterford Steam Electric Station, Unit 3 - Meeting Slides - NFPA 805 LAR Supplement

ML14035A094
Person / Time
Site:	Waterford
Issue date:	02/04/2014
From:	Entergy Operations
To:	Office of Nuclear Reactor Regulation
Wang A B
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Download: ML14035A094 (29)

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Waterford 3 -NRC Public Meeting February 4, 2014 1NFPA 805 LAR Supplement IntroductionChanges to Supporting Analyses Resulting Impact to:Risk (CDF, LERF) Modifications and Implementation ItemsRecovery Actions LAR Attachment Change SummaryComparison of Risk Areas to Original LAR Impact on RAIs Questions/General Discussion 2 Agenda Updated Internal Events PRA and Fire PRA Resolved Request for Additional Information (RAIs)Updated Fire PRA to use accepted methods.Corrected legacy issuesUpdate to the Nuclear Safety Capability Assessment (NSCA) impacted Variance from Deterministic Requirements (VFDRs) and Recovery Actions 3Introduction Addressed RAI'sResolved Peer Review F&O'sCCW Makeup Ultimate Heat Sink Modeling (Fan Requirements)HVAC Requirements by Fire Area/Room LERF Containment Isolation Size Threshold (> 2 Inches)Containment Atmosphere Release System (CARS) Modeling Update o Routine 5 year Update (Plant Changes/Data Update) 4Changes to Supporting Analysis Internal Events PRA Majority of Changes Addressing RAI'sUpdated to use accepted methodsControl Room Abandonment Analysis (CCDP)Fire Modeling ChangesRefined Transient and Fixed Source ScenariosRefined MCA including Sensitive ElectronicsFire Scenario Analysis Transient Combustible AnalysisHeat Release Rates (HRRs) increasedSecondary Combustibles (RAB 27 impact) 5Changes to Supporting Analysis Fire PRA Transient Combustible Fire Heat Release Rates 69 kW to 317 kW Severity Factor for Severe Pump Oil Fires2/98 to 10/90 Large oil pump fire/Small oil pump fire split fraction Adjustment Factors RemovedTransient Combustible Fire Ignition FrequencyHot Work Ignition Frequency Electric Cabinet Fire Ignition Frequency 6Changes to Supporting AnalysisAddressed RAIs Related to PRA Methods EDG Severity Fire Factor RemovedUse of assumed CCDP (Probability of mitigation failure) to calculated valueControl Room Abandonment TGB Structural Failure oSensitive Electronics -Temperature threshold for damage 7Changes to Supporting AnalysisRAIs Addressed in Supplement Separated NSCA and SSA Calculations VFDR list re-validatedRemoved Cold Shutdown (CSD) VFDRsRemoved unnecessary VFDRs for Recovery Actions, Heymc and multiple Success PathsVFDRs identified in 3 additional Fire Areas: TGB, EDG A, and CCW HX ARemoved credit for Partial Height Walls:Relay Room (RAB7)Switchgear Room (RAB8) 8Changes to Supporting AnalysisNuclear Safety Capability Assessment (NSCA) 3 New FREs prepared for TGB, EDG A, and CCW HX A Fire AreasRelay Room (RAB 7) Analyzed as one Fire AreaSwitchgear Room (RAB 8) Analyzed as one Fire AreaSingle Recovery Action to Manually Trip RCP Motor Breakers in 4 Fire Areas (RAB 1, RAB 7, RAB 8, TGB)N2 Accumulator mission time increased to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> 9Results due to Analysis ChangesFire Risk Evaluations (FREs) o 22 MOVs Require Modification to eliminate IN 92-18 Concerns oFire Area RAB 6 requires ERFBS to support Risk Assumptions (4 Fire Areas in Original LAR) o Radiant Barrier not required in RAB 2 to protect the Essential Chillers oHEAF Barrier not required in Fire Area RAB 8 oSecondary Combustible removal in Fire Area RAB 27 10 11 Resulting Impacts Original LAR Supplement Risk CDF 3.4 E-51.62E-5 CDF 8.4 E-62.31E-6 LERF 7.3E-7 2.89 E-6 LERF 1.1E-7 1.29 E -7 Number of Mods MOVs 15 22 ERFBS (wrap) 4 1 HEAF Barrier 1 0 Radiant Barrier 1 0CodeCompliance 7 7 Recovery Actions 30 4 Same RA in 4 Areas Attachment A (B-1 Table)Section 3.3.8 revised to state WF3 does not have Bulk Storage of Flammable Liquids located in Structures containing SSCs important to nuclear safety Section 3.11.5 revised to state ERFBS required in Fire Area RAB 6 onlyAttachment B (B-2 Table) NEI 00-01 Rev 1 to Rev 2 Gap Analysis updates 12 Attachment Change Summary Attachment C-Table C-1(B-3 Table)Regenerated to reflect 31 new/revised FREs and revised formatRevised Licensing Actions (Attachments K and T)Attachment C -Table C-2 (Formerly Table 4-3) Regenerated to reflect 31 new/revised FREs and Revised formatRevised Licensing Actions (Attachments K and T)Attachment G -(Recovery Actions)Recovery Actions changed due to revised FREsSingle Action (Manually Trip RCP Motor Breakers in TGB Switchgear)4 Fire Areas (RAB 1, RAB 7, RAB 8, TGB) 13 Attachment Change Summary Attachment H (FAQs)Updated to reflect revised FPRA methodsAdded 06-0016 "Ignition source counting guidance for Electrical Cabinets"06-0017 "Ignition source counting guidance for High Energy Arcing Faults (HEAF)" 06-0018 "Ignition source counting guidance for Main Control Board (MCB)" 10-0059 (updated to Revision 5) "Monitoring Plan"Removed 08-0042 "Fire propagation from electrical cabinets" (Did not screen any cabinets due to being "sealed" construction)08-0044 "Large spill oil fire size" (not used) 14 Attachment Change Summary Attachment J (Fire Modeling V&V)Regenerated due to changes in Fire ModelingAttachment K(Licensing Actions)LAR Supplement transitions 5 Deviations (12, 16, 36, 42 & 43) Original LAR transitioned 23 NRC-approved Deviations13 Deviations not required per New GL 86-10 evaluations5 Deviations not required under NFPA 805 Separation requirements 15 Attachment Change Summary Attachment S (Plant Modifications and Implementation Items)Table S-1 Revised/New S1-1 revised list of MOVs due to IN 92-18 Evaluation UpdateS1-5 Removed ERFBS (fire wrap) requirements for Fire Areas RAB 2, RAB 5, RAB 17 S1-8 Updated text in "Risk Informed Characterization" columnS1-14 (New) Action to remove combustibles from Fire Area RAB 27S1-15 (New) Added MOVs to modify to eliminate IN 92-18 failure mechanism on valves that their failure is undesirable, however are not credited in the FREs.Table S-1 Deletions S1-2 no MOVs needed to modify for NPO. S1-3 HEAF Barrier in RAB 8(c) not required S1-4 Radiant Barrier in RAB 2 not requiredS1-6 Recovery Actions that required additional lighting (local operation of HVAC components) not required 16 Attachment Change Summary Attachment S (Plant Modifications and Implementation Items) oTable S-2 Items S2-8 Revised to add procedure EN-DC-161 "Control of Combustibles" to support DID recommendationsS2-21 (New) Revise surveillance procedure to preserve fire scenario-specific mission time assumptions in Fire PRA for selected Nitrogen Accumulators S2-22 (New) Verify the validity of the analysis results post-mod and procedure updatesS2-9 Deleted, floor markings are not required 17 Attachment Change Summary Attachment T (NRC Clarifications) 2 previous Clarifications deleted due to completion of new GL 86-10 Evaluations Control Room Barrier EDG removable wall panelsAttachment U (Internal Events PRA Quality)Regenerated due to revised models and Focused Peer Reviews51 Total F&OsAll 37 Impacting FPRA Closed14 Open F&Os with no impact on FPRA8 deal with Flooding Analysis6 related to internal PRA documentation 18 Attachment Change Summary Attachment V (Fire PRA Quality)Updated to include F&Os and corresponding dispositions from new Focused Scope Peer Review of the Fire PRA Removed Section V.2 which provided Alternate Methods SensitivityAttachment W (Fire PRA Insights)Regenerated due to revised Fire PRA and FREs 19 Attachment Change Summary 20Resulting Fire Area Ranking S u p p l e m e n t r a n k CDF L A R r a n kCDFNotes RAB 1 1 6.90E-06 3 3.17E-06Doubled due to detailed MCR abandonment analysis RAB 7 2 4.33E-06 2 3.67E-06Similar number -increase due to multi-compartment and sensitive electronic issues, but reduced due to re-mapping corrections RAB 8 3 2.55E-06 1 1.63E-05Updated number smaller by factor of 10 primarily due to component mapping (limited dual bus failures)

TGB 4 1.01E-06 20 3.12E-08TGB much higher now due to removal of oil fire split fraction and use of plant specific suppression reliability RAB 15 5 3.84E-07 7 5.63E-07Higher due to removal of split fraction methodfor EDG fire RAB 16 6 3.01E-07 14 1.43E-07Higher due to removal of split fraction method for EDG fire RAB 31 7 1.92E-07 18 3.55E-08 Increase due to update transient methodology (higher HRR with larger ZOI = more targets).YARD 8 1.37E-07 5 7.88E-07Yard was redefined to include Fire Pump House and Condensate Polisher Bldg RAB 2 36 1.20E-09 4 3.00E-06Reduced due to removal of HVAC requirementsfrom PRA model for many areas.

21Resulting Scenario Ranking (Top 9)

LAR Scenario CDF% Total CDF Supplement Scenario CDF% Total CDF 31AB SWGR Fire with HEAF1.12 E-532.8MCR Transient Fire w/ HVAC 2.43 E-6 15.0 Aux Panel 4 Fire 2.82 E-6 8.33B SWGR Fire with HEAF 7.17 E-7 4.4 1B SWGR Fire (7kV) 1.33 E-6 3.9MCR Transient Fire w/ No HVAC7.16 E-7 4.4 CP-10 Fire 1.03 E-6 3.0Relay Room Fixed Source Fire MCA 6.64 E-7 4.1 3B SWGR Fire with HEAF 7.46 E-7 2.2Relay Room Transient Fire in RAB 7A 5.24 E-7 3.2Oil Fire A & B Chillers 6.88 E-7 2.0Relay Room Fixed Source Fire MCA 4.42 E-7 2.7Chilled Water Pump A Oil Fire (Moderate) 6.61 E-7 1.9Relay Room Fixed Source Fire MCA 4.42 E-7 2.7Chilled Water Pump B Oil Fire (Severe) 6.61 E-7 1.9MCR Electrical Cabinet Fire with HVAC and abandonment 4.42 E-7 2.7ESFAS 3A Panel Fire 5.65 E-7 1.7MCR Electrical Cabinet Fire with No HVAC and abandonment 3.03 E-7 1.9 22 Resulting Impacts Original LAR Supplement Risk CDF 3.4 E-51.62E-5 CDF 8.4 E-62.31E-6 LERF 7.3E-7 2.89 E-6 LERF 1.1E-7 1.29 E -7 Number of Mods MOVs 15 22 ERFBS (wrap) 4 1 HEAF Barrier 1 0 Radiant Barrier 1 0CodeCompliance 7 7 Recovery Actions 30 4 Same RA in 4 Areas Information contained in many RAI responses is superseded by the Supplement and supporting documentation/analysisSome RAI responses provided description of methodology, results of preliminary analysis or sensitivity studies, with indication of pending future analysis.In most cases, the descriptions remain valid, however, the numerical values in the LAR Supplement supersede those in the RAI.In some cases, the reanalysis replaces the RAI response information in total.Some RAIs are no longer applicable as the methods in question have been replaced with methods that are believed to be acceptable.

23 Resulting Impacts RAIs RAI Responses Superseded by LAR Supplement 1 24 Resulting Impacts RAIs PRA-01 PRA-20 PRA-33 PRA-45 PRA-56 PRA-07 PRA-21 PRA-34 PRA-47 PRA-57 PRA-12 PRA-23 PRA-35 PRA-50 PRA-58(b)PRA-13 PRA-28 PRA-38 PRA-51 PRA-59 PRA-16 PRA-29 PRA-42 PRA-53 FPE-05 PRA-17 PRA-32 PRA-44PRA-54(d)SS-14 PRA-18 1 Preliminary Review PRA-06 & PRA-40The methodology discussion in the below RAI responses remain valid, however, the numerical results from the Supplement should be used in lieu of data from the RAI responses due to new or revised analysis.PRA-11, PRA-43, PRA-52,SS-02, SS-02.01 a(iii), &

SS-06Revisions to Table S-1 supersedes information in the RAIs. SS-07, SS-08, & SS-13 Attachment G revisions supersedes information in the RAIs. PRA-05 Nitrogen accumulator availability duration is 24 hrs SS-01NSCA calculation is EC-F13-001, not revision to ECF00-026 25 Resulting Impacts RAIs 1 1 Preliminary Review 26 26Responses to Draft PRA RAIs RAI #SubjectDispositionBasis RefernecePRA RAI 01.01 Explain how "plausible secondary ignition sources" are definedExplain: Actual analysis performed PRA-W3-05-006TPRA-W3-05-006FPRA RAI 04.01FRE description should clarify how ignition frequency and CCDP are considered together with other aspects of the fire scenario, such as propagation, detection, and suppression.This process is only briefly covered in the FRE(s) but is in very good detail in the DID report (WF3-FP-13-0004). WF3-FP-13-0004PRA RAI 10.01 Did FRE results include UAMs as basis for evaluation riskNo UAMs, see FM-07 responseN/A no UAMsPRA RAI 16.01 Impact to sensitive electronics in "non-adjacent cabinets" Analysis accounts for Sensitive electronics, see FM-07 responsePRA-W3-05-006TPRA-W3-05-006FPRA RAI 25.0115 minutes for the manual non-suppression probability is "listed time to damage for secondary cable targets of 19 minutes from NUREG/CR-6850"Cite references for 15 min assumption and sensitive electronics sensitivity studyPRA-W3-05-006TPRA-W3-05-006FPRA RAI 29.01 (a)PAU ceiling heights of 7 or 12 ft, or the assumed cabinet height of 7 ft, describe how the generic methodology is applied Explain: Analysis used actual ceiling heightsPRA-W3-05-005 Rev 1PRA RAI 29.01 (b)Reference is made to two groupings for HRRs, 69 kW and 702 kW. It is unclear where these groupings ariseNew methodology conforms to 6850, RAI is no longer applicablePRA-W3-05-005 Rev 1PRA RAI 29.01 (c)With regard to the 69 kW HRR grouping discussed in (b), Clarify HGL screeningExplain: 69 kw not used. See FM-07 for HGL discussionPRA-W3-05-005 Rev 1PRA RAI 43.01Clarify which S table items are in PRA modelExplain S-1 & S-2 mods. Attachment S 27 27Responses to Draft PRA RAIs (cont.)

RAI #Subject DispositionBasis Refernece PRA RAI 44.01 (a)PRA data counting method Explain with requested justificationAttachment U PRA RAI 44.01 (b)

HEP value based on timing changeThe action associated with this RAI (operation of SI-120/121) is no longer credited (CSD)PRA-W3-05-003 PRA RAI 44.01 (c)PRA RAI 44e and stated that the assumed HEP value for EHFMANTNR has no impact on the FPRA results since the event does not appear in a single cutsetEHFMANTNR in cutset with CDF ~1E-13 in IEPRA. Not in Fire PRA cutset due to truncationPSA-WF3-01-HR PRA RAI 44.01 (d)WCT success criteria Explain: modeled nowPRA-WF3-01-SC PRA RAI 44.01 (e)The explanation of modeling of the battery in RAI PRA 44h, but did not provide sufficient information Explain: Add detailPSA-WF3-01-SYS PRA RAI 44.01 (f)Loss of inventory over time considered with flow diversions in Fire PRA?Explain: 1/3 acceptable flow diversion may impact inventory over time. This consequence in FPRA?PRA-W3-05-040 PRA RAI 53.01Modeling of SOVs in Fire PRA including SOV's that are part of AOV'sSOV hot shorts included with actuator failure as appropriate (EFW valves, for example)PSA-W3-03-01 PRA RAI 58.01 (a)

Clarify "the non-compliant case includes basic events that no credit can be given to when compliant with NFPA 805"Explain: eliminate use of confusing verbiagePSA-WF3-03-01 RSC 13-19PRA RAI 58.01 (b), (c), (d)Explain "True" as used in Franx and FPRA Fault trees The term/verbiage "True" is not longer in the supporting documentation No longer applicable PRA RAI 58.01 (e) VFDRs with "Open" StatusOpen' status in the previous submitted LAR meant that the associated VFDR had a proposed modification associated with it. The updated LAR B-3 does not use the term 'open' and has more specific status classifications.

No longer applicable PRA RAI 60HEP is set to a value of TRUE then the joint human error probability (JHEP) is set to 0.Explain: model should already be fixedPRA-W3-05-043 PRA RAI 61 (a)How failure to isolate component cooling water (CCW) is modeled in FPRAExplain: how are CCW cross connects handled in modelPRA-W3-05-040 PRA RAI 61 (b)How CCW makeup modeled in FPRA. CCW makeup system is not included in the FPRA according to Table B-3 of the LARPRA-W3-05-040 was done and the result was to add the CCWMU support to the model. Basically any size flow diversion in CCW may require makup since it is closed loop with fixed inventory. The makup function is not explictly modeled.PRA-W3-05-040 o LAR SupplementAddresses RAIs Provides results using methods described in NUREG/CR-6850 Overall Risk Results are comparable to original LAR Minimal Changes to list of Modifications and Implementation Items oWaterford 3 will support any additional working level meeting(s) on technical details necessary for RAI closure.

28 Conclusions Questions?