ML15154B050

Risk Analysis to Support Response to Requests for Additional Information Regarding One Time Emergency License Amendment Request to Revise Tech Spec Section 3.8.1 to Permit Extending the Completion Time. (RAI-APLA 1)

ML15154B050
Person / Time
Site:	Cook
Issue date:	05/29/2015
From:	Heyeck J M Indiana Michigan Power Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
Shared Package
ML15154B043	List: AEP-NRC-2015-52, Response to a Request for Additional Information Regarding the Emergency License Amendment Request to Extend the Allowed Outage Time for an Emergency Diesel Generator ML15154B048 ML15154B050
References
AEP-NRC-2015-52
Download: ML15154B050 (16)

Text

Enclosure 6 to AEP-NRC-2015-52Risk Analysis to Support Response to Requests for Additional Information RegardingOne Time Emergency License Amendment Request to revise Technical SpecificationSection 3.8.1 to permit extending the Completion Time. (RAI-APLA 1) mraN'D. C. COOK NUCLEAR PLANTE&ECTRICPWRCALCULATION/REPORT COVER SHEET[]~bw Bull Renw-denuDocument No. PRA-QNT-005 Rev No, 0[]Status ChangeTitle: Additional Calculation of Regulatory Guide 1.177 Risk Parameters for Potential One-Time EmergencyTechnical Specification Completion Time Change for Unit I AB EDGSTATUS: Z Approved El Superseded El Voided Ii Information OnlyDocument Type/Class: ED Calculation EI Report [] Class 1 0I Class 2 Z Class 3QUALITY SYSTEM UNIT COMPUTER REVIEW METHOD:CLASSIFICATION: CODE: NO.: MEDIA: 0 Detailed ReviewEl Safety-Related 0I Yes El Alternate CalculationLI Non-Safety Related with NAPL I No El OtherSpecial Requirements N N/A -Status/Class Change Only[ Non-Safety RelatedDo any assumptions require later verification? U Yes 0 No If yes, Al No.Description: See PurposeThis non-design calculation is exempted by the approver from the configuration management requirements of 12-EHP-5040-DES-003 section 3.4.5.If the Reviewer is the Preparer's supervisor, the supervisor review is needed and is approved:O N/ASupervisor's Manager's Name Title Signature DateQualification Matrix Verification* The responsible Engineering Supervisor/Manager approval signature also serves to signify that thequalifications of the individual(s) assigned as Preparer(s) and Reviewer(s) and Independent Design Verifier(s)were verified in the Plant Qualification Matrix.Preparation & ReviewPREPARED BY: REVIEWED BY: *APPROVED BY:Name: James M. Heyeck Stephen J. Cherba Andrew Garrett-title: PRA Engineer PRA Engineer ManagerOrganization; Engineering Programs/PRA Engineering Programns/PRA. E ing PgramsSignature:Date: 2Z,'- -( --o _, --. 5El Sign-offs for additional Preparer(s) and Reviewer(s) on next pageThis document includes the following pages: 1-17 (17 Pages total) Page 1 Calculation No. PRA-QNT-005, Rev. 0 Page 2 ITable of Contents1 Purpose ................................................................................................................. 52 M ethodology ................................................................................................... 63 Inputs ................................................................................................................... 74 Assumptions .................................................................................................... 85 Calculations ..................................................................................................... 85.1 2009 Internal Events & Internal Flooding Model Items Addressed in Updated ModelPertinent to Unit 1 AB EDG CT Extension ............................................................................ 85.2 Clarification of Sources of Reduced Risk -Internal Events M odel ........................... 95.3 Fire PRA Model Items Addressed in Analysis Model Pertinent to Unit 1 AB EDG CTE x ten sion ................................................................................................................................... 105.4 Clarification of Sources of Reduced Risk -Fire PRA M odel .................................. 115.5 Risk Analysis Using the 2009 Internal Events PRA Model of Record ...................... 135.6 CDF and LERF Results ............................................................................................... 146 Conclusions .................................................................................................... 157 References .......................................................................................................... 16 I Calculation No. PRA-QNT-005, Rev. 0 Page 3 [List of TablesTable 5.1-1 -Internal Events & Internal Flooding PRA Model Issues and Resolutions for Unit I AB EDG CTE xten sion ................................................................................................ ....... ................................................... 8Table 5.2-1 -Internal Events Model I-EE Review Summary .................................................................................. 10Table 5.3-1 -Fire PRA Model Issues and Resolutions for Unit I AB EDG CT Extension ................................... 10Table 5.4-1 -Fire PRA H FE Review Sum m ary ......................................................................................................... 11Table 5.5-1 -Basic Event Settings for Baseline CDF and LERF without SDS ...................................................... 13Table 5.5-2 -Basic Event Settings for Unit I AB EDG Failed CDF and LERF without SDS ............................. 13Table 5.6-1 -2009 Internal Events Model vs. Updated Internal Events Model Total CDF and LERF Results ......... 14Table 5.6-2 -ICCDP and 1CLERP Results for 65 Day Completion Time ............................................................ 14List of AttachmentsA ttachm ent I -Files on C D ........................................................................................................................................ 17 I1 Calculation No. PRA-QNT-005, Rev. 0Paize 4 1I Calculation No. PRA-ONT-005. Rev. 0 Pa~e4 IList of AbbreviationsAFWAMSACATWSCCPCDF-CSTCRDMCTSCVCSECCSEDGEOPESFASESWFWF-VHEP1HFEHLRHSSICCDPICLERP1ELERFLOCALSSMAAPMDAFPMOR or MORWMTINRCOOSPACPORVPRAPDSPRMRAWRCPRCSRHRRWSTSDGSBOSGSRSSPSSISIPTDAFPTSAuxiliary FeedwaterATWS Mitigating System Actuation CircuitryAnticipated Transient Without ScramCentrifugal Charging PumpCore Damage FrequencyCondensate Storage TankControl Rod Drive MechanismContainment Spray systemChemical and Volume Control SystemEmergency Core Cooling SystemEmergency Diesel GeneratorEmergency Operating ProcedureEngineered Safety Features Actuation SystemEssential Service WaterFeedwaterFussell-VeselyHuman Error ProbabilityHuman Failure EventHigh Level RequirementHigh Safety SignificantIntegrated Conditional Core Damage ProbabilityIntegrated Conditional Large Early Release ProbabilityInternal EventsLarge Early Release FrequencyLoss of Coolant AccidentLow Safety SignificantModular Accident Analysis ProgramMotor-Driven Auxiliary Feedwater PumpModel of RecordMaintenance Technical -Instrument and ControlNuclear Regulatory CommissionOut of service or UnavailablePlant Air CompressorPower-Operated Relief ValveProbabilistic Risk AssessmentPlant Damage StatePlant Response ModelRisk Achievement WorthReactor Coolant PumpReactor Coolant SystemResidual Heat RemovalRefueling Water Storage TankSupplemental Diesel GeneratorStation BlackoutSteam GeneratorSupporting RequirementSolid State Protection SystemSafety InjectionSafety Injection PumpTurbine-Driven Auxiliary Feedwater PumpTechnical Specification I Calculation No. PRA-QNT-005, Rev. 0 Page 51 PurposeThis calculation provides clarifications on changes made to the 2009 PRA Model of Record and the Fire PRAModel of record in support of the Unit I AB EDG one time completion time extension. This information is intendedto provide a response to the NRC's Request for Additional Information regarding the updated, but not yet peerreviewed Internal Events PRA model. It also provides clarification on items that were updated following thepreliminary risk assessment in both the updated Internal Events and Fire PRA model.

I Calculation No. PRA-QNT-005, Rev. 0 Page 6I Calculation No. PRA-QNT-005, Rev. 0Page 62 MethodologyThe PRA risk impact of operation with Unit I AB EDG unavailable was estimated using an application specificupdated WinNUPRA PRA Model (Input 3.1) and an updated Fire PRA model (Input 3.2), modified for thisapplication as described in Reference 7.17. Since the updated Internal Events model has not yet been peer reviewed,this calculation provides results fi'om the 2009 Internal Events PRA Model of Record, for comparison purpose withthe updated model. Regulatory Guide 1.177 (Reference 7.12) risk parameters are calculated using the followinggeneral equations:ACDF = CDFi,, -CDFisewhereCDFinjst = the Unit I CDF value when only the Unit I AB EDG is unavailable, with appropriateallowances for the Unit 2-PAC & I W-MDAFP OOS time and the operation andmaintenance restrictions described below (Assumption 4.1) are in placeCDFb .the Unit 1 "base case" zero maintenance CDF value (with the exceptions shown inAssumption 4.1).ALERF = LERFe,,. -LERFb1ScwhereLERFi,, = the Unit 1 LERF value when only the Unit I AB EDG is unavailable, with an appropriateallowance for the Unit 2-PAC & IW-MDAFP OOS time, and the operation and maintenancerestrictions described below (Assumption 4.1) are in placeLERFnve = the Unit I "base case" zero maintenance LERF value (with the exceptions shown inAssumption 4.1).ICCDP = (ACDF)*(Duration (days) / 365 days/year)ICLERP = (ALERF)*(Duration (days) /365 days/year)Consistent with the cases developed in Section 2 of Reference 7.17, two quantification cases are provided for the2009 Internal Events model.1. A baseline CDF and LERF value with zero maintenance other than the exceptions listed in Assumption 4.1,without credit for the SDS.2. CDF and LERF values with the Unit I AB EDG failed, with zero maintenance other than the exceptionslisted in Assumption 4.1, without credit for the SDS I Calculation No. PRA-QNT-005, Rev. 0 Page 73 Inputs3.1 The 2009 WinNUPRA model of record (Reference 7. 1) is currently undergoing a fill model update. Resultsare provided firom the 2009 model in this calculation, and are provided for comparison to the updated modeldocumented in Reference 7.17.3.2 The Fire PRA model of record (Reference 7.2) was changed for this application as described in Reference7.17. The results firom Reference 7.17 are used in this calculation.

I Calculation No. PRA-QNT-005, Rev. 0 Page 8 14 Assumptions4.1 The average PRA model test and maintenance factors for the following equipment are adjusted to match theout of service durations during the Unit 1 AB EDG unavailability:* The Unit I West MDAFP was unavailable for approximately 28 hours3.240741e-4 days <br />0.00778 hours <br />4.62963e-5 weeks <br />1.0654e-5 months <br />. The test and maintenanceterm is therefore adjusted to 28 Irs/ (14 days

• 24 Ir's). This conservatively accounts for 28 hours3.240741e-4 days <br />0.00778 hours <br />4.62963e-5 weeks <br />1.0654e-5 months <br /> ofunavailability during the onethne extended EDG unavailability window." The Unit 2 PAC was unavailable for approximately 14 hours1.62037e-4 days <br />0.00389 hours <br />2.314815e-5 weeks <br />5.327e-6 months <br />. The test and maintenance term istherefore adjusted to 14 hour1.62037e-4 days <br />0.00389 hours <br />2.314815e-5 weeks <br />5.327e-6 months <br />s/(14 days

• 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />). This conservatively accounts for 14 hours1.62037e-4 days <br />0.00389 hours <br />2.314815e-5 weeks <br />5.327e-6 months <br /> ofunavailability during the onetime extended EDG unavailability window.o The Unit I Middle Heater Drain Pump remained out of service for the majority of the EDGunavailability. This pump is not modeled in the Internal Events or Fire PRA,o Required surveillance runs with short-duration (-15 rains)unavailabilities are not considered. Thisincludes surveillance tests on other EDGs to prove that they remain operable. For EDG runs,multiple equipment operators are stationed at the EDG being tested, such that the EDG can berestored in short order.4.2 All previous assumptions listed in Reference 7.17 are used in this analysis, with the exception of the ESWcrosstie configuration, since no flag settings exist in the 2009 Internal Events model to account for thisconfiguration. This is judged to have an insignificant impact on the overall results, for the same reasons asAssumption 4.7 in Reference 7.17 for the Fire PRA.5 Calculations5.1 2009 Internal Events & Internal Flooding Model Items Addressed in Updated ModelPertinent to Unit 1 AB EDG CT ExtensionThe 2009 Internal Events & Internal Flooding PRA Model contains shortcomings that have the potential to impactthe Unit I AB EDG Completion Time extension. The shortcomings, their resolution, and their impact to the.assessment is provided in the table below.Table 5.1-1 -Internal Events & Internal Flooding PRA Model Issues and Resolutions for Unit I AB EDG CTExtension-2609 Model of-Record Identified Issue Re.oi*-ioni E Updated ModelAverage test and maintenance values were None. The test and maintenance Test and Maintenance valuesincorrectly squared due to a misunderstanding of configuration of the plant is known were adjusted back to theirthe conditional probabilities involved with for the risk analysis. original values, and updated withsupport system initiating events, the latest plant specific data.ESW and CCW pump recovery tenms were Small. Dual Unit SBO sequences Pump repair/recovery is noapplied in internal flooding and dual unit SBO are low probability and have a small longer credited for Internalsequences in which pump repair was unlikely, impact on the assessment Flooding or Dual Unit SBO Pave 9 1I Calculation No. PRA-ONT-005. Rev. 0 Pg.2009 Model of Record Identified"Issue Impact to .AR EDG CT Resolution in Updated Mode.ExtensionNo safety train alignment was considered for theSDGs. The SDGs are procedurally directed to be Safety Train alignment for thealigned to a single safety train on one unit. Small. Dual Unit SBO sequences SDGs was added. This makesAlthough crews would be expected to re-align are low probability and have a small the updated model SBOthem to the alternate train if the first train incurred impact on the assessment contributions higher for therandom equipment failures, no direct procedural SDGs.guidance exists to direct this consideration.A reduction factor was incorrectly used for Significant Impact to the totalsupport system initiating events to reduce the Internal Events CDF, but not acontribution of common cause terms. T[his Itra vnsCF u ocotreduction ofator don eusue thecom on Thisignificant impact to this Reduction factor was removed.reduction factor was used to ensure the cohnilon assessment. Support system This significantly raises the CDFcause. failure only occured during the technical initiating events do not challenge and LERF contribution firomspecification allowed outage times during the offsite power availability and thus Loss of CCW and ESW in theyear. Since common cause failure factors already the unavailability of a single EDG updated model.include the consideration of the failures occurring does not significantly impact thewithin a short time period of each other, this assessment.reduction factor is unnecessary.The WOG 2000 RCP Seal LOCA model was not MAAP analyses have beenModerate. Plant Specific MAAP performed for SBO and updatedfilly incorporated. SBO offsite power recovery analysis provides a better realistic offsite power recovery times(CNU) probabilities ra than being justified by estimate of offsite power recovery were used. This generallyMAAP analysesi times. reduces the SBO contributions inthe updated model.Tile amount of sequences on event trees and the None. Thle quantification issues Event trees were simplified. Nototal number of event trees were unnecessarily only impacted processing time and overall effect on the updatedcomplicated leading to quantification issues, had no hipact on results, model.A full data update wasInitiating event and component data is sourced Moderate. Newer data is more performed for the model update.from older data sources and out of date. representative of the current Component data generallyoperating plant. improved, so this will reduce thecontributions across the model.Very Small. Internal Flooding does Internal Events HFEs wereInternal Flooding initiating events contained not challenge offsite power updated to reflect correct 1EPs.simplified HFEs for isolation of the break which availability and thus the Minor change in overall floodrequire updating. unavailability of a single EDG has a contribution.minor impact on internal flooding.5.2 Clarification of Sources of Reduced Risk -Internal Events ModelSeveral HFEs related to offsite power were reviewed in the updated Internal Events model as part of the riskassessment. The -FEs which resulted in the majority of the CDF reduction fiom the preliminary assessment to thefinal assessment are discussed below:

I Calculation No. PRA-QNT-005, Rev. 0Calclaton N. PA-QN-00, Re. 0Pave 10-110 [Table 5.2-1 -Internal Events Model HFE Review SummaryOriginal~ uiaeWIE, Dscription Assessed Bavalu for- changeHEEP valueExecution stress should not be high asassumed in the HRA due to large time to"Operator Fails top peform perform actions and ease of action.I EXE-RCCHE e 2.8E-2 2.96E-04 Added a recovery step in the execution.RCS cooldown after SBO Procedure step requires operators tocheck SG pressure. This can be used asrecovely in the H RA analysis.Changed time window to 1.62 hrs basedon core uncovery time fi'om MAAP0A-EP-TBUS--HE Operator fails to align 4.14E-2 1.39E-02 Case LI 33d (Reference 7.7). ReducedSDGs to Safety Bus stress level to low because of highSPAR-H ratio.Dependent HIFE The listed actions to not have a conunonCombination of 1 Th.ite.ciost.othv.ac.oCOMBO 41 EXE-RCCiniE and oA-EP- 4.14E-2 1.24E-04 cognitive event (different cues). TheyTBUJS---HE are sequential actions:Operator fails to fullyopen CCW to RHR Heat Decreased level of dependency to lowIC ------ ALIGNHE Exchanger valves after 5.2E-3 2.60E-03 due to high available time for action.ECCS recirculationswitchover5.3 Fire PRA Model Items Addressed in Analysis Model Pertinent to Unit I AB EDG CTExtensionThe Fire PRA Model of Record contains shortcomings that have the potential to impact the Unit I AB EDGCompletion Time extension. The shortcomings, their resolution, and their impact to tile assessment is provided inthe table below.Table 5.3-1 -Fire PRA Model Issues and Resolutions for Unit 1 AB EDG CT ExtensionFire PRA.Model Identified Issue Imipact to i AB EDG CT:ixtension Resolution foi- RishkAssessmentThe Fire PRA reduced the successcriteria for AFW from supplying 2 of 4SGs to 1 of 4 SGs. This reductionrequires containment spray to be Non-conservative success criteria foravailable (References 7.6 and 7.7) to AFW would have a moderate and non- This is conrected in the Fire PRA modelprevent containment failure since conservative impact on the risk used for this application.insufficient containment heat removal is assessment.provided by one SG. This is corrected inthe Fhre PRA model used for thisapplication.

I Calculation No. PRA-QNT-005, Rev. 0page I1 III Calculation No. PRA-ONT-005. Rev. 0 Page 11 IFire PRA Model Identified Issue Impact to 1 ABR EDG CT Extensioni Resolution for. Risk AssessmnentAn HFE was credited in the Fire PRA tore-power the Hydrogen Igniters after For this application, there is increasedfires which left all the busses faulted on The value of the frequency weightedthe fire affected unit. This action takes average f changesequen the m odelithe Unit I AB EDG is not available.3.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> to complete and it was average HEP changes when the model Therefore, a risk mitigating action is takenhoursfie lto complthe tandsitio weidtas configuration does, particularly if fire- t tg h lent oe upyscidentified late in the transition period that induced SBO becomes more to stage ac alternate power supply suchthe time to core damage could be as little significant. that the action can be completed within theas 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> in some sequences (such as 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> time window. No adjustment isAFW failure). The HEP was averaged in made to the HIEP on the basis of this actionthe final model to account for this.The fire-induced SBO fault tree(I SBOINIT.LGC) was noted to contain Since this application increases the RCS inventory makeup via the CVCSan en'or. Successful operation of the likelihood of an SBO, this results in an crosstie was added to this event. AlternateTDAFP constituted success of the top increase in both the base model and the success path based on MAAP analysisgate, despite the fact that an RCP Seal application results. included a RCS cooldown.LOCA would occur due to the blackout.5.4 Clarification of Sources of Reduced Risk -Fire PRA ModelIn the Fire PRA model of record, the 480 gpm/pump Seal LOCA could not be mitigated by the CVCS crosstie basedon MAAP analyses (Reference 7.7). This placed a significant emphasis on the HFE to trip the RCPs within 8minutes (I ----- CCW-RCPHIEF). No RCS cooldown was credited in the model of record analysis, even though acooldown is directed in the Emergency Remote Shutdown procedure (Reference 7.14) and in the Post-LOCAcooldown and depressurization procedure (Reference 7.16). For this risk assessment it was desired to show thatthere was significant conservatism in the importance of tripping the RCPs. The MAAP analysis was performed inReference 7.17, Section 5.2, and shows successful mitigation of the 480 gpm/pump RCP seal LOCA with thecooldown credited. This significantly reduced the risk associated with tripping the RCPs.In addition to the credit for performing an RCS cooldown, the HFEs in the table below were reviewed. In particular,1ASD-SBONOTDPOMA was reviewed because it contributed the majority of the preliminary delta risk. Afterreview and operator interview, this HFEs were re-evaluated in the HRA calculator at a reduced stress level, resultingin a reduction of the HEP. These changes, in combination with the credited cooldown provided the risk decreasefrom the preliminary delta risk valuesdiscussed with NRC.Table 5.4-1 -Fire PRA HFE Review SummaryOriginal UpdatedH1E 'Description Asslessed, 'UEP Basis for ChangeITEPivalue V.al!e'HFE will retain the value of 4.9E-2 and be usedOperator Fails to Crosstie AFW ONLY for scenarios in which the fire occurslASD- and CVCS per Emergency inside the main control room, and stress isRemote Shutdown (Reference 4.9E-2 4.9E-2 expected to be high. Although, the HEP value in7.14) for fires that occur in the the HRA Calculator is 1.33E-02. This value wasMain Control Room left at 4.9E-2 for conservatism in the final NFPA805 model of record.

I Calculation No. PRA-QNT-005, Rev. 0Pap-e 12 1original UpdatedOEDsription Assessed H-EP Basis for ChangHEPv.alue Value....... ..... eNew HFE.HFE will model what IASD-SBONOTDPOMA used to for scenarios inwhich the fire occurs outside the main controlroom, and stress is expected to be moderate.The original EEP assessment foaOperator Fails to Crosstie AFW l ASD-SBONOTDPOMA is very conservative in1FSBO--XTJE- and CVCS per Emergency that a High Operator stress level has beenRemote Shutdown (Reference 4.9E-2 5.3E-03 assigned by default generating a high HEP value.7.14), for fires that do not occur However, since the action is practiced every twoin the Main Control Room years, the plant should respond as expected (i.e.,operators have the plant under control and arefamiliar and comfortable with the actions andprocedures required, workload might be high,but PSFs should be optimal. This was confirmedby operators on phone interview (5/26/2015),therefore a moderate stress level is selected.New HFE.lIFE will model a 14F/hr cooldown per OHP-Operator Fails to initiate RCS 4025-001-00 1, step 25 given success ofCooldown after success of 1FSBO--XTIE-OMA using the same timeI FSBO---RCC- CVCS and AFW crosstie per N/A 6.58E-04 window, based on new MAAP analysis.OMA Emergency Remote Shutdown Execution Time for operator action is 15(Reference 7.14) minutes, confirmed by operators. Moderatestress level assumed based on operator phoneInterview discussed above.Removed firom the model and superseded byI FSBO---RCC-OMA, since the cooldown is1B-RV-- Operator fails to manually open 1.3E-2 N/A credited for fire-induced SBO only, whereMIRV2X3HEF SG PORVs. CVCS and AFW crosstie must first besuccessful.HeLEP agreed upon between DC Cook and theCCW- Operator Fails to Locally Trip 4.80E-03 4.80E-03 NRC and cannot be changed. If stress reduced,RCPHEF RCPs REP = -2E-03 1 Calculation No. PRA-QNT-005, Rev. 0Pap-e 13 11i CacltonN.PAQN-0.Rv. 0Pg 13i5.5 Risk Analysis Using the 2009 Internal Events PRA Model of RecordTwo cases of the 2009 ]ntfernal Events PRA Model of Record are run consistent with the cases developed in Section2, and Reference 7.17. The Unit I West MDAFP and Unit 2 Plant Air Compressor unavailability is taken fiomAssumption 4.1. These cases are:1. A baseline CDF and LERF value with zero maintenance other than the exceptions listed in Assumption 4.1,without credit for the SDS. For this case, the following basic event modifications are made:Table 5.5-1 -Basic Event Settings for Baseline CDF and LERFComponent Basic Event ProbabilityUnit I West MDAFP IDBPM---PP3WTM 8.333E-2Unit 2 Plant Air Compressor 2X-CM---OME4TM 4.167E-2All other Test or Maintenance Events Basic Events ending in "TM" 02. CDF and LERF values withl the Unit I AB EDG failed, with zero maintenance other than the exceptionslisted in Assumption 4.1, without credit for the SDS. For this case, the following basic event modificationsare made:Table 5.5-2 -Basic Event Settings for Unit I AB EDG Failed CDF and LERFComponent Basic Event ProbabilityUnit 1 AB EDG 1 SBDG ---- DGABFR 1Unit I West MDAFP IDBPM ---- PP3WTM 8.333E-2Unit 2 Plant Air Compressor 2X-CM---OME41TM 4.167E-2All other Test or Maintenance Events Basic Events ending in "TM" 0

[ Calculation No. PRA-QNT-005, Rev. 0 Page 15.6 CDF and LERF ResultsThe CDF and LERF results fi-om each case are shown below in Table 5.6-1. The ICCDP and ICLERP calculationsare shown below in Table 5.6-2. ICCDP and ICLERP are calculated assuming a 65 day completion time, using theequations in Section 2. Updated Internal Events and Fire PRA values are obtained from Reference 7.17.41Table 5.6-1 -2009 Internal Events Model vs. Updated Internal Events Model Total CDF and LERF Resultsh.i.terp.al DF LERF Internial ie its CDF vlEvents LERFCase ,20~09 Model .2009 Model> Updated Model < -Updated Model>/r /r /Yr) Oir.Basecase 1.412E-05 2.867E-06 1.268E-04 4.237E-06I AB EDG Failed 1.963E-05 3.454E-06 1,304E-04 5.119E-06Table 5.6-2 -ICCDP and ICLERP Results for 65 Day Completion TimeCase DeltCDF (ij! Delt ".(LtFye) :'ICCDP.. JCLERP2009 Internal Events 5.51E-06 5.87E-07 9.81 E-07 1.05E-07Updated Internal Events 3.60E-06 8.82E-07 6.41E-07 1.57E-07Fire PRA 1.9613-05 7.97E-07 3.49E-06 1.42E-07Total (2009 Internal Events & Fire PRA) 2.5 1E-05 1.38E-06 4.47E-06 2.46E-07Total (Updated Internal Events & Fire PRA)2.32E-052.27E-064.13E-064.04E-07 I Calculation No. PRA-QNT-005, Rev. 0 Page 156 ConclusionsThe 2009 Internal Events PRA model provides a slightly larger estimate of lCCDP and a 50% smaller estimate ofICLERP than the updated Internal Events model. Using the 2009 Model of Record and the Fire PRA, the calculatedvalues of4.47E-06 ICCDP and 2.46E--7 ICLERP are within the Regulatory Guide 1.177 acceptance guidelines ofless than IE-5 ICCDP and IE-6 ICLERP for one time TS completion time changes, given a total TS completiontime of 65 days (Reference 7.12). This one-time TS completion time change is therefore considered acceptable.