ML13022A411

San Onofre Nuclear Generating Station, Unit 2, Response to Request for Additional Information (RAI 11) Regarding Confirmatory Action Letter Response (TAC Me 9727)

ML13022A411
Person / Time
Site:	San Onofre
Issue date:	01/21/2013
From:	St.Onge R J Southern California Edison Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
TAC ME9727
Download: ML13022A411 (21)

Text

SOUTHERN CALIFORNIAAn EDISON INTERNATIONAL CompanyRichard I. St. OngeDirector, Nuclear Regulatory Affairs andEmergency PlanningJanuary 21, 201310 CFR 50.4U.S. Nuclear Regulatory CommissionATTN: Document Control DeskWashington, DC 20555-0001Subject:Docket No. 50-361Response to Request for Additional Information (RAI 11)Regarding Confirmatory Action Letter Response(TAC No. ME 9727)San Onofre Nuclear Generating Station, Unit 2References: 1.Letter from Mr. Elmo E. Collins (USNRC) to Mr. Peter T. Dietrich (SCE), datedMarch 27, 2012, Confirmatory Action Letter 4-12-001, San Onofre NuclearGenerating Station, Units 2 and 3, Commitments to Address Steam GeneratorTube Degradation2. Letter from Mr. Peter T. Dietrich (SCE) to Mr. Elmo E. Collins (USNRC), datedOctober 3, 2012, Confirmatory Action Letter -Actions to Address SteamGenerator Tube Degradation, San Onofre Nuclear Generating Station, Unit 23. Letter from Mr. James R. Hall (USNRC) to Mr. Peter T. Dietrich (SCE), datedDecember 26, 2012, Request for Additional Information Regarding Responseto Confirmatory Action Letter, San Onofre Nuclear Generating Station, Unit 2Dear Sir or Madam,On March 27, 2012, the Nuclear Regulatory Commission (NRC) issued a Confirmatory ActionLetter (CAL) (Reference 1) to Southern California Edison (SCE) describing actions that the NRCand SCE agreed would be completed to address issues identified in the steam generator tubesof San Onofre Nuclear Generating Station (SONGS) Units 2 and 3. In a letter to the NRC datedOctober 3, 2012 (Reference 2), SCE reported completion of the Unit 2 CAL actions andincluded a Return to Service Report (RTSR) that provided details of their completion.By letter dated December 26, 2012 (Reference 3), the NRC issued Requests for AdditionalInformation (RAIs) regarding the CAL response. Enclosure 1 of this letter provides theresponse to RAI 11.P.O. Box 128San Clemente, CA 92672 Document Control Desk-2-January 21, 2013There are no new regulatory commitments contained in this letter. If you have any questions orrequire additional information, please call me at (949) 368-6240.Sincerely,Enclosures:1. Response to RAI 11cc: E. E. Collins, Regional Administrator, NRC Region IVJ. R. Hall, NRC Project Manager, SONGS Units 2 and 3G. G. Warnick, NRC Senior Resident Inspector, SONGS Units 2 and 3R. E. Lantz, Branch Chief, Division of Reactor Projects, NRC Region IV ENCLOSURE 1SOUTHERN CALIFORNIA EDISONRESPONSE TO REQUEST FOR ADDITIONAL INFORMATIONREGARDING RESPONSE TO CONFIRMATORY ACTION LETTERDOCKET NO. 50-361TAC NO. ME 9727Response to RAI 11Page 1 RAI 11Please submit an operational impact assessment for operation at 70% power. The assessmentshould focus on the cycle safety analysis and establish whether operation at 70% power iswithin the scope of SCE's safety analysis methodology, and that analyses and evaluations havebeen performed to conclude operation at 70% power for an extended period of time is safe.The evaluation should also demonstrate that the existing Technical Specifications, includinglimiting conditions for operation and surveillance requirements, are applicable for extendedoperation at 70% power.RESPONSENote: This response includes information requested in RAI 14 associated with the operationalimpact assessment for operation at 70% power. RAI 14 states: "Provide a summary dispositionof the U2C1 7 calculations relative to the planned reduction in power operation."SCE has evaluated the extended reduced power operation for its impacts on the Unit 2 Cycle 17reload core design and safety analysis. The power levels evaluated range from 50% to 100%rated thermal power, which bounds the planned operation at the 70% power level. Theassessments were performed in accordance with NRC approved SONGS reload methodologyand topical reports referenced in the UFSAR and Technical Specification (TS) 5.7.1.5, and theSONGS Core Reload Analyses and Activities Checklist procedure.The impacts of extended reduced power operation on Unit 2 Cycle 17 core design and reloadanalyses, including UFSAR Chapter 15 safety analyses are summarized in Table 1, the impactassessment table. The impact assessment table is organized consistent with the SONGS CoreReload Analyses and Activities Checklist procedure. For each analysis, the Reload Checklistitem number is listed in the second column from the left; when applicable, the second columnalso lists the UFSAR Chapter 15 safety analysis section number. The determination of impactfor each analysis is summarized in the right column of the table.Safety Analysis MethodologyThe NRC approved safety analysis methods, as described in TS 5.7.1.5, are used to establishthe core operating limits specified in the Core Operating Limits Report (COLR) whichencompass from Mode 6 up to Mode 1 operation at the rated thermal power. Therefore,operating at the 70% power level is within the scope of SCE safety analysis methodology. Nochange to the safety analysis methodology is required for extended reduced power operation.Safety AnalysisThe reload and safety analyses determined to be impacted by extended reduced poweroperation were re-analyzed. The conclusions of the reload analyses, including safety analyses,for extended reduced power operation are as follows: (1) All safety analyses results meet theestablished acceptance criteria, and (2) The radiological dose consequences for all safetyanalyses remain bounded by the dose consequences reported in the UFSAR.Page 2 Technical SpecificationsThe existing TS, including limiting conditions for operation (LCO) and surveillance requirements,are applicable for extended operation at 70% power. The impact assessment for TSsurveillance requirements is described in the following section.Impact Assessment for Technical Specification Surveillance RequirementsThe TS surveillance requirements were evaluated for the impacts of reduced power operation.The evaluation concluded all TS surveillance requirements under the reactor core design andmonitoring program that would have been performed at approximately 82% power or at fullpower will be performed with the plant operating at approximately 70% power. The evaluation issummarized in Table 2.Two surveillance procedures related to monitoring Reactor Coolant System (RCS) flow wererevised to (1) reduce the minimum power required to perform the surveillances from 85% to68% power, and to (2) account for the slightly increased RCS flow uncertainty at reduced poweroperation. No other surveillances were identified to be impacted by plant operation at 70%power.ConclusionsExtended reduced power operation at 70% power has been evaluated and determined to beacceptable with respect to Unit 2 Cycle 17 reload core design and safety analysis. Reloadanalyses needed to support reactor startup and operation at 70% power have been completed.All TS LCO and surveillance requirements under the reactor core design and monitoringprogram normally performed at or above 70% power will be performed with the plant operatingat approximately 70% power. The above evaluations demonstrate that the existing TSs,including limiting conditions for operation and surveillance requirements, are applicable forextended operation at 70% power.Page 3 Table 1SONGS Unit 2 Cycle 17 Reduced Power Operation -Summary of Impact Assessment ofReload and UFSAR Chapter 15 Safety AnalysesITEM CHECKLIST ITEM 1# (UFSAR SECTION) DESCRIPTION SUMMARY OF IMPACT ASSESSMENT1 0.1 Reload Ground Rules (RGR) Review No change to analysis is required. No change to Rated Thermal Power (RTP). RGR stilladdresses 0% to 100% RTP operation. RGR addresses the full range of powerindependent and power dependent operating parameters, including those applicable atreduced power. The RGR Analysis Value defines the maximum or minimum value whichmust be bounded in the safety analysis. The number is not necessarily equivalent to thevalue used in an analysis (or Technical Specification) but will be conservative with respectto that value. The RGR Analysis Value includes applicable uncertainties and margins forwhich the safety analyses must be bounding.2 1.1.3 Design Models and Depletions Re-analysis was performed to determine impact, and all results were acceptable.Calculation revised to document depletion at 50% power from Beginning of Cycle (BOC)to End of Cycle (EOC) and comparison to 100% power. SONGS Unit 2 Cycle 17 ($2C17)at 50% power results in radial power distributions (at the same power level and burnup)essentially identical to depleting the core at 100% power.As the radial power distributions and distortion factors have been determined to be valid,no downstream analyses are impacted.Impact of extended reduced power operation on generic axial shapes and scram curves isaddressed in Item 10 (1-D HERMITE model.)3 1.1.4 Design Parameters and FR Versus No change to analysis is required. Radial power distributions and generic axial shapesPower remain applicable. Individual Control Element Assembly (CEA) worth, CEA bank worth,scram worth, peaking factors, distortion factors that are strongly dependent on the radialpower distribution remain applicable. Extended reduced power operation results in lessPu-239 inventory. As such, generic bounding parameters (i.e., Fuel TemperatureCoefficient (FTC), Moderator Temperature Coefficient (MTC), kinetics parameters) remainapplicable. Critical Boron Concentrations (CBC) at Beginning of Cycle (BOC) are notaffected. CBC at End of Cycle (EOC) is similar. Therefore, bounding boron concentrationrequirements and Inverse Boron Worths (IBW) are not impacted. Representative designparameter and Fr values for Reload Analysis Report (RAR) are not impacted.Page 4 Table 1SONGS Unit 2 Cycle 17 Reduced Power Operation -Summary of Impact Assessment ofReload and UFSAR Chapter 15 Safety AnalysesITEM ICHECKLIST ITEM 11# C SECTION) DESCRIPTION SUMMARY OF IMPACT ASSESSMENT# (UFSAR SECTION)4 1.1.5 Physics Input to LOCA, TORC, and No change to analysis is required for the physics inputs to LOCA analysis and TORCFATES Analysis (including Pin code analysis. BOC, limiting boron concentration, reactivity are not affected. RadialCensus) power distribution and peaking data remain applicable. Generic LOCA and TORC inputparameters remain applicable.Re-analysis was performed for the physics input to Fuel Performance Analysis (FATES)code analysis. Radial fall-off curves, Fr, and fast flux data were regenerated for reducedpower operation. Generic axial shapes remain applicable.5 1.1.6 Physics Input to Fuel Mechanical Re-analysis was performed to determine impact, and all results were acceptable.Design Calculation revised to provide power history data for AREVA Lead Fuel Assembly (LFA)mechanical design analysis. Also updated maximum core residence time forWestinghouse analysis. Other generic parameters for Westinghouse mechanical designanalysis remain applicable due to similar radial power distribution.6 1.1.7 Physics Input to ASGT No change to analysis is required. Physics Input to Asymmetric Steam GeneratorTransient (ASGT) is performed at EOC with most negative Technical Specification MTC.Calculations performed at multiple power levels (90%, 70%, 50%, and 20%). Due tosimilar power distributions, results remain applicable.7 1.1.8 Physics Input to Post-Trip Steam Line No change to analysis is required. Analysis performed at EOC. Radial power distributionsBreak Analysis (at the same power level and burnup) are essentially identical. The MTC is tuned to themost negative Tech Spec value (-3.7E-4 Ak/k/fF). Cooling down adds reactivity. Morereactivity is added cooling from 100% power (higher T-fuel and T-mod) than reducedpower to lower temperatures (e.g., 5450F, 3000F, 2000F, 68°F)8 1.1.9 Physics Input to CEA Ejection Analysis No change to analysis is required. Physics data in this analysis were generated atmultiple power levels and the reduced power operating range is covered. Since thereduced power operation results in power distributions essentially identical to those from100% power operation, the data generated from the original analysis are applicable toreduced power operation.9 1.1.10 Physics Input to CEA Withdrawal No change to analysis is required. Calculations performed at multiple power levels.Radial power distributions (at the same power level and burnup) are essential identical.CEA worth remains applicable since it is strongly dependent on power distribution.Limiting axial power shapes from axial shape index (ASI) search remain applicable.Page 5 Table 1SONGS Unit 2 Cycle 17 Reduced Power Operation -Summary of Impact Assessment ofReload and UFSAR Chapter 15 Safety AnalysesITEM CHECKLIST ITEMIE DESCRIPTION SUMMARY OF IMPACT ASSESSMENT# (UFSAR SECTION)10 1.1.11 1-D HERMITE Model Re-analysis was performed to determine impact, and all results were acceptable. Analysisis revised to establish applicability of the generic axial shapes used in the design analysesand applicability of the SCRAM curves used in the design analyses. Analysis also showsthat depletion at reduced power leads to essentially the same limiting shapes from ASIsearch as those selected for the analyses of the design depletions.11 1.1.12 Physics Input to Steam Line Break No change to analysis is required. This EOC event begins at 0% power. Radial powerReturn-to-Power for Cycle N-1 distributions (at the same power level and burnup) are essentially identical.Configuration12 1.1.13 FR Versus Temperature for Cooldown No change to analysis is required. Bounding distortion factors were determined based onEvents multiple CEA configurations, temperature ranges at BOC and EOC. Radial powerdistributions (at the same power level and burnup) are essentially identical.13 1.1.14 Boron Requirement for SITs and No change to analysis is required. The case run for this calculation is performed at hotBAMU Tanks zero power (HZP). The Xenon starting condition is Hot Full Power (HFP) which isconservative.14 1.1.15 LOCA and Non-LOCA Source Term No change to analysis is required. This analysis tests the Cycle 17 conditions of interestagainst the parameters required for applicability of the LOCA and Alternative Source Term(AST) source terms. The power level is used as a maximum not to be exceeded. RunningCycle 17 at reduced power results in less "short half-life" nuclides. Increase in "long half-life" nuclides due to extended calendar time is bounded by the lower production fromextended reduced power.15 1.1.16 Tritium Production No change to analysis is required. Reduced power results in a decrease in tritiumproduction. The analysis at 100% power is conservative.16 1.1.17 STAR Physics Verification No change to analysis is required. This analysis uses BOC (HZP) conditions (Mode 3) foran assessment for S2C 17 inclusion in the Startup Test Activity Reduction (STAR)program.17 1.1.18 Digital Setpoints Physics Data No change to analysis is required. The case sets encompass LCO and Limiting SafetySystem Settings (LSSS) ASI ranges. Power level does not impact axial shapessignificantly, so reduced powers are covered by the case set.Page 6 Table ISONGS Unit 2 Cycle 17 Reduced Power Operation -Summary of Impact Assessment ofReload and UFSAR Chapter 15 Safety AnalysesITEM ICHECKLIST ITEM1I CAECTION) DESCRIPTION SUMMARY OF IMPACT ASSESSMENT# (UFSAR SECTION)18 1.1.19 Physics RAR Inputs Re-analysis was performed to determine impact, and all results were acceptable. RARhas been updated to reflect actual Cycle 16 EOC burnup and Cycle 17 reduced poweroperation.19 1.2.1 Fuel Performance Analysis (FATES) Re-analysis was performed to determine impact, and all results were acceptable.Reduced power results in fuel performance data that is not bounded when compared tothe Generic Fuel Performance data generated for ZIRLOTM in Cycle 14 (data used inLOCA Analysis). A revision to the Fuel Performance and Setpoints Analyses wasperformed to determine the appropriate penalty factors such that the Generic FuelPerformance data remained bounding.20 1.2.2 T-H Input Summary No change to analysis is required. Calculation is a collection of input data that are notimpacted by reduced power.21 1.2.4 T-H Limiting Assembly and CETOP No change to analysis is required. Power is not an input. Calculation is a benchmark ofBenchmarking Analysis CETOP to TORC computer codes at reference departure from nucleate boiling (DNBR)points rather than a benchmark at a given power. This benchmark is mainly driven bypower distributions from physics. Physics Models & Depletions has validated the powerdistributions used in the original calculation.22 1.2.5 Mechanical Design Analysis (Fuel Re-analysis was performed to determine impact, and all results were acceptable.Vendor) Westinghouse performed calculations to determine the impact of reduced power on thefuel mechanical design.AREVA performed calculations to determine the impact of reduced power on the LeadFuel Assembly fuel mechanical design.23 1.2.6 Power Operating Limit Partial No change to analysis is required. The calculation is driven by a large family of axialDerivative Verification shapes, which are not impacted by the power reduction.24 1.2.7 Setpoints Input Summary Re-analysis was performed to determine impact, and all results were acceptable.Calculation has been revised to address the increased reactor coolant system (RCS) flowuncertainty at reduced power.25 1.2.8 RCS Flow Uncertainties Re-analysis was performed to determine impact, and all results were acceptable. Hasbeen reanalyzed. RCS flow uncertainty increases due to reduced delta-temperature andincreased secondary calorimetric power uncertainty.Page 7 Table 1SONGS Unit 2 Cycle 17 Reduced Power Operation -Summary of Impact Assessment ofReload and UFSAR Chapter 15 Safety AnalysesITEM CHECKLIST ITEM DESCRIPTION SUMMARY OF IMPACT ASSESSMENT# (UFSAR SECTION)26 1.2.9 Fuel Mechanical Design Verification No change to analysis is required. The objective of the fuel mechanical design verificationcalculation is to document the design of the fuel based on the fuel vendor Bill of Materials,Design Drawings and the design and material specifications transmitted from the fuelvendor. Reduced power operation has no impact on this analysis.27 1.2.11 Secondary Calorimetric Power No change to analysis is required. Intermediate powers were explicitly analyzed in theUncertainty original calculation.28 1.2.12 Delta-T/Turbine Power Uncertainties No change to analysis is required. The analysis uses a reference power error of 1.3% atfull power. The increase in reference power (i.e., secondary calorimetric power)associated with performing delta-t/turbine power calibrations at reduced power wouldincrease the uncertainties. The bounding results include -0.50% of conservatism;therefore, the analysis of record (AOR) remains bounding. Intermediate powers wereexplicitly analyzed in the original calculation.29 1.2.13 Cycle Independent Data and Setpoints No change to analysis is required. CIDSAL provides cycle independent values to use or toAssumptions List (CIDSAL) be verified in downstream analyses. Reduced power operation does not impact therequirements for downstream analysis verification. None of the calculations explicitlyperformed in the analysis section are dependent upon nominal plant operating conditionsor the power shapes/distributions at reduced power operation.30 1.2.16 Core Protection Calculator (CPC) No change to analysis is required. Intermediate powers were explicitly analyzed in theCalibration Allowances original calculation. Due to less decalibration, full power bounds lower power levels.31 1.2.17 Fuel Duty Index No change to analysis is required. Full power bounds lower power levels.32 1.2.18 T-H MSCU Verification No change to analysis is required. Power is not an input. Calculation is a verification ofresponse surface at reference DNBR points rather than a benchmark at a given power.33 1.2.19 CEA STAR Verification No change to analysis is required. Radial power distributions (at the same power leveland burnup) are essentially identical. At reduced power the plan is to continue to operatewith all rods out. The duration and depth of lead bank CEA insertion beyond the typicalall-rods-out position is monitored per the core follow procedure with notification/action toreview the conservative CEA life analysis when insertion exceeds an insertion assumptionwithin the analysis.Page 8 Table 1SONGS Unit 2 Cycle 17 Reduced Power Operation -Summary of Impact Assessment ofReload and UFSAR Chapter 15 Safety AnalysesITEM CHECKLIST ITEM DESCRIPTION SUMMARY OF IMPACT ASSESSMENT# (UFSAR SECTION)34 1.3.1 Summary of Transients Re-analysis was performed to determine impact, and all results were acceptable.Calculation was revised to perform an evaluation of all Updated Final Safety AnalysisReport (UFSAR) Chapter 15 events for extended reduced power operation.35 1.3.2 CENTS Cycle Update and Action No change to analysis is required. Calculation and associated computer files alreadyModules accommodate power levels from 0 to 100 percent.36 1.3.3 (15.10.1.3.1.1) Main Steam Line Break (MSLB) No change to analysis is required. Pre-trip SLB is analyzed @100% power (withPre-Trip uncertainty). The generic physics inputs remain unchanged. Since the VOPT isgenerated on the rate of change in power setpoint (DELSPV), the actual trip occurs at thesame power rise, independent of the starting power level. As this is a Required OverPower Margin (ROPM) event, the actual initial power level chosen is not significant to theevent.37 1.3.4 (15.10.1.3.1.2) MSLB Post-Trip No change to analysis is required. This event is limiting at hot zero power (HZP). HZPcases show greatest return to power since there is minimum initial stored energy, decayheat and scram worth at HZP conditions. There is no impact to the HZP cases since HZPphysics inputs and initial conditions do not change. A reactivity balance for reduced powershowed that net reactivity change remained negative.38 1.3.5 (15.10.4.1.4) Chemical Volume Control System No change to analysis is required. This is a BOC event that is not analyzed in Mode 1.(CVCS) Malfunction -Boron Dilution The reactivity addition due to a boron dilution event is less adverse than the CEAWithdrawal event at Power and therefore Mode 1 and the higher power portion of Mode 2are not explicitly addressed.39 1.3.6 (15.10.4.1.1) CEA Bank Withdrawal from Subcritical No change to analysis is required. Event is evaluated at subcritical conditions. Note that(CEAW @ SC) this event is being re-evaluated to address the extended shut down.40 1.3.6 (15.10.4.1.1) CEA Bank Withdrawal at Low Power No change to analysis is required. Event is evaluated at hot zero power conditions.(CEAW @ HZP)41 1.3.6 (15.10.4.1.2) CEA Bank Withdrawal at Power No change to analysis is required. CEAW at reduced power is enveloped by CEAW @(CEAW @ Power, 50% & 100%) 50% Power and CEAW @ 100% Power; and the results are acceptable.42 1.3.8 (15.10.1.1.3) Increased Main Steam Flow (IMSF) No change to analysis is required. The system response is the same as IMSF+SF.Page 9 Table 1SONGS Unit 2 Cycle 17 Reduced Power Operation -Summary of Impact Assessment ofReload and UFSAR Chapter 15 Safety AnalysesITEM CHECKLIST ITEM1(USA SECTION) DESCRIPTION SUMMARY OF IMPACT ASSESSMENT# (UFSAR SECTION)43 1.3.8 (15.10.1.2.3) IMSF with Single Failure (SF) No change to analysis is required. IMSF+SF (fast & slow) analyzed @100% power. Thegeneric physics inputs remain unchanged. The fast case credits the VOPT which isgenerated on the rate of change in power (DELSPV) setpoint, as such the actual tripoccurs at the same power rise, independent of the starting power level. Since the fastcase is a Required Over Power Margin (ROPM) event, the actual initial power levelchosen is not significant to the event. The limiting event is the slow trip, which is initiatedfrom a Power Operating Limit. As such, the actual initial power level chosen is notsignificant to the event.44 1.3.9 (15.10.4.3.2) CEA Ejection Re-analysis was performed to determine impact, and all results were acceptable. Theevent is normally analyzed at multiple power levels. It was reanalyzed to address reducedpower data from the fuel performance analysis.45 1.3.10 (15.10.3.3.1) Reactor Coolant Pump Shaft Seizure No change to analysis is required. Bounded by Reactor Coolant Pump Sheared Shaft(RCPSS).46 1.3.10 (15.10.3.3.2) Reactor Coolant Pump Sheared Shaft No change to analysis is required. This is a margin/ fuel failure calculation event. The(RCPSS) thermal margin loss for this event is initiated by the loss of flow from one pump (eitherseized rotor or sheared shaft). The reduction of thermal margin due to the loss of flowfrom one pump is not a function of the initial power (i.e., is constant at any power level).In addition, at reduced power, the initial thermal margin is larger than at the 100% powercondition. Therefore, the analysis at full power is bounding.47 1.3.11 (15.10.2.1.3) Loss of Condenser Vacuum (LOCV) No change to analysis is required. Bounded by LOCV+SF48 1.3.11 (15.10.2.2.3) LOCV with Single Failure No change to analysis is required. This event is driven by plant response and not bydetailed core physics. There are two criteria (peak RCS pressure and peak secondarypressure). At lower powers, there is less internal energy in the reactor core, whichtranslates into a slower RCS pressure transient that is more rapidly mitigated by mainsteam safety valves (MSSVs). The peak secondary pressure event is evaluated atmultiple power levels to establish the allowed power level as a function of the number ofgagged MSSVs (Tech Spec 3.7.1).49 1.3.12 (15.10.6.3.2) Steam Generator Tube Rupture No change to analysis is required. The SGTR is a slow event and not sensitive to initial(SGTR) power. Furthermore, at lower powers there is a higher secondary pressure that translatesto lower primary-to-secondary rupture flow (i.e., lower activity release).Page 10 Table 1SONGS Unit 2 Cycle 17 Reduced Power Operation -Summary of Impact Assessment ofReload and UFSAR Chapter 15 Safety AnalysesITEM CHECKLIST ITEM DESCRIPTION SUMMARY OF IMPACT ASSESSMENT# (UFSAR SECTION)50 1.3.13 (15.10.1.1.4) Inadvertent Opening of a Steam No change to analysis is required. See IOSGADV+SFGenerator Safety or an AtmosphericDump Valve (IOSGADV)51 1.3.14 (15.10.1.2.4) IOSGADV with Single Failure No change to analysis is required. The IOSGADV+SF is analyzed at a power level of 11 MWt.52 1.3.15 (15.10.9.1.1) Asymmetric Steam Generator No change to analysis is required. The ASGT event was analyzed in the AOR at multipleTransient (ASGT) power levels (90%, 70%, 50%, and 20%).53 1.3.16 (15.10.1.1.1) Decrease in Feedwater Temp (DFWT) No change to analysis is required. Since feedwater heating is reduced at reduced power,the potential loss in feedwater heating is also reduced. Impact at reduced power is alsomitigated by increased mass in RCS and Steam Generators (SGs) and increasedrecirculation in SGs at lower power.54 1.3.17 (15.10.1.2.1) DFWT with Single Failure No change to analysis is required. Since feedwater heating is reduced at reduced power,the potential loss in feedwater heating is also reduced. Impact at reduced power is alsomitigated by increased mass in RCS and Steam Generators and increased recirculation inSGs at lower power.55 1.3.18 (15.10.1.1.2) Increase in Feedwater Flow (IFF) No change to analysis is required. Primary to secondary heat transfer is dominated byheat of vaporization (Hfg) which is considerably greater than steam generator enthalpyrise resulting from sensible heat. Consequently, cool downs resulting from Increases inFeedwater Flow events are limited by Increases in Main Steam Flow events. Further,Increases in Steam Flow events occur more rapidly as changes in Feed Water aremitigated by the liquid mass and recirculation flow in the steam generators. Further factorsthat mitigate Increasing Feedwater Flow events at reduced power include greater RCS /SG mass, increased recirculation flow in the sfeam generators, greater steam generatorpressure and earlier reactor trip from increased feedwater flow -steam flow mismatch.56 1.3.18 (15.10.1.2.2) IFF with Single Failure No change to analysis is required. The most adverse single failure postulated for IFF isthe opening of all Steam Bypass Control System (SBCS) valves. Because the Increase inMain Steam Flow (IMSF) event postulates the opening of all SBCS valves and assumesthat Main Feedwater flow increases to match steam flow, the IFF with Single Failure is theessentially the same event as the IMSF event. Therefore, conclusions regarding IMSF areapplicable to IFF with Single Failure.Page 11 Table 1SONGS Unit 2 Cycle 17 Reduced Power Operation -Summary of Impact Assessment ofReload and UFSAR Chapter 15 Safety AnalysesITEM CHECKLIST ITEM DESCRIPTION SUMMARY OF IMPACT ASSESSMENT# (UFSAR SECTION)57 1.3.19 (15.10.2.1.1) Loss of External Load (LOL) No change to analysis is required. The system response to the Loss of External Load,Turbine Trip, and the Loss of Condenser Vacuum are essentially the same. Therefore,the relationship between the events will remain the same at reduced power. As suchthese events remain bounded by LOCV.58 1.3.19 (15.10.2.2.1) LOL with Single Failure No change to analysis is required. The system response to the Loss of External Loadwith single failure, Turbine Trip with single failure, and the Loss of Condenser Vacuumwith single failure are essentially the same. Therefore, the relationship between theevents will remain the same at reduced power. As such these events remain bounded byLOCV+SF.59 1.3.19 (15.10.2.1.2) Turbine Trip (TT) No change to analysis is required. The system response to the Loss of External Load,Turbine Trip, and the Loss of Condenser Vacuum are essentially the same. Therefore,the relationship between the events will remain the same at reduced power. As suchthese events remain bounded by LOCV.60 1.3.19 (15.10.2.2.2) TT with Single Failure No change to analysis is required. The system response to the Loss of External Loadwith single failure, Turbine Trip with single failure, and the Loss of Condenser Vacuumwith single failure are essentially the same. Therefore, the relationship between theevents will remain the same at reduced power. As such these events remain bounded byLOCV+SF.61 1.3.20 (15.10.2.1.4) Loss of Normal AC Power (LONAC) No change to analysis is required. See LONAC+SF62 1.3.20 (15.10.2.2.4) LONAC with Single Failure No change to analysis is required. Operation at lower power level is less challenging withrespect to maintaining an adequate heat sink.63 1.3.21 (15.10.2.2.5) Loss of Normal Feedwater (LONF or No change to analysis is required. See LOFW+SFLOFW)64 1.3.21 (15.10.2.3.2) LOFW with Single Failure No change to analysis is required. Operation at lower power level is less challenging withrespect to maintaining an adequate heat sink.Page 12 Table 1SONGS Unit 2 Cycle 17 Reduced Power Operation -Summary of Impact Assessment ofReload and UFSAR Chapter 15 Safety AnalysesITEM CHECKLIST ITEM DESCRIPTION SUMMARY OF IMPACT ASSESSMENT# (UFSAR SECTION)65 1.3.22 (15.10.2.3.1) Feedwater System Pipe Breaks (FSPB No change to analysis is required. Peak primary and secondary pressure events wereor FWLB) analyzed at the least negative MTC value and main feedwater enthalpy corresponding tofull power. The slightly higher MTC corresponding to reduced power is offset by the lowermain feedwater enthalpy at reduced power. Operation at lower power level is lesschallenging with respect to maintaining an adequate heat sink. The energy in the plant isless at reduced power relative to full power, and therefore pressurizer overfill is boundedby the full power response.66 1.3.23 (15.10.5.1.1) CVCS Malfunction No change to analysis is required. See CVCS Malfunction+SF.67 1.3.23 (15.10.5.2.1) CVCS Malfunction with Single Failure No change to analysis is required. The energy in the plant is less at reduced powerrelative to full power, and therefore pressurizer overfill is bounded by the full powerresponse. Operation at lower power level is less challenging with respect to maintainingan adequate heat sink.68 1.3.24 Pressurizer Spray Malfunction No change to analysis is required. See Core Protection Calculator (CPC) Dynamic FilterAnalysis.69 1.3.25 (15.10.4.1.5) Reactor Coolant Pump (RCP) -Start No change to analysis is required. Modes 1 and 2 were not analyzed because operationUp of an Inactive Loop in these Modes is only allowed with all 4 RCPs running.70 1.3.27 (15.10.4.3.2) CEA Ejection (peak pressure analysis) No change to analysis is required. The event is limiting at hot zero power (HZP).71 1.4 (15.10.6.3.3) Emergency Core Cooling System Re-analysis was performed to determine impact, and all results were acceptable. Impact(ECCS) Analyses including LBLOCA, assessment addressed in analyses performed by Fuel Vendors.SBLOCA and LTC72 (15.10.5.1.2) Inadvertent Operation of ECCS at No change to analysis is required. The system response to the IOECCS and CVCSPower (IOECCS) malfunction events are essentially the same. Therefore, the relationship between theevents will remain the same at reduced power. As such this event continues to bebounded by CVCS malfunction event.73 (15.10.5.2.2) IOECCS with Single Failure No change to analysis is required. The system response to the IOECCS with singlefailure and CVCS malfunction with single failure events are essentially the same.Therefore, the relationship between the events will remain the same at reduced power.As such this event continues to be bounded by CVCS malfunction event with singlefailure.Page 13 Table 1SONGS Unit 2 Cycle 17 Reduced Power Operation -Summary of Impact Assessment ofReload and UFSAR Chapter 15 Safety AnalysesITEM CHECKLIST ITEM DESCRIPTION SUMMARY OF IMPACT ASSESSMENT# (UFSAR SECTION)74 (15.10.6.3.1) Primary Sample or Instrument Line No change to analysis is required. Mass releases are driven by energy in the primaryBreak (PSILB) system which is highest following operation at HFP. The event does not fail fuel, and thereis no ROPM requirement.75 (15.10.6.3.4) Inadvertent Opening of a PSV (IOPSV) No change to analysis is required. The IOPSV event is bounded by small break LOCA.76 1.5.1 Applicability Evaluation of Source No change to analysis is required. There is no change to core activity inventory sourceTerms in Dose Analyses term.77 1.5.2 Cycle Specific Dose Analysis No change to analysis is required. No Cycle 17 event-specific dose analysis wasperformed, therefore no impact for reduced power.78 1.5.4 Applicability Evaluation of Dose Re-analysis was performed to determine impact, and all results were acceptable. RevisedAnalyses to document that the currently modeled radial peaking factors are conservatively greaterthan the increased radial peaking factors at reduced power.The transient analyses and mass release analyses are evaluated at the current 8% steamgenerator (SG) tube plugging limit. The dose calculation uses mass release data per thetransient analyses and their assumed 8% SG tube plugging models. The calculation isrevised with discretionary conservatism to model 20% SG tube plugging in the calculationof the RCS dilution volume and mass considered for non-LOCA events which have claddamage. Evaluated RCS dilution mass at RCS temperatures for both 50% and 100%power, which envelopes powers between 50% and 100%.The mass release calculations are evaluated for a core inlet temperature (Tcold) of 560F,which maximizes core average temperature (Tave). Currently modeled mass releasevalues in the Summary of Transients (SOT) correspond to full power operation. The SOTdid not identify an increase in the amount of steam released from the secondary sidebecause it remains more limiting compared to operation at lower power level due to lowersensible heat in the RCS and lower post trip decay heat.Page 14 Table 1SONGS Unit 2 Cycle 17 Reduced Power Operation -Summary of Impact Assessment ofReload and UFSAR Chapter 15 Safety AnalysesITEM CHECKLIST ITEM 1 SUMMARY OF IMPACT ASSESSMENT# (UFSAR SECTION) DESCRIPTION79 n/a Fuel Corrosion and Oxide Thickness No change to analysis is required.(BOA Code) analysis The Westinghouse BOA code analysis for cycles 15, 16 and 17 was performed as part ofthe Zinc Injection project. This calculation compared predicted values for corrosion andoxide thickness, Fuel Duty Index and crud dryout to the Westinghouse ChemistryGuideline limits.Maximum values of Fuel Duty Index and Crud Dryout are driven by fresh fuel operating athigh power. Operation at reduced power would be bounded by the 100% power cases runin the analysis of record (AOR).Maximum values of corrosion and oxide thickness are driven by both power level andeffective full power days (EFPD). The AOR assumed a core operating strategy whichwould maximize corrosion and oxide; running fuel for three full cycles, a total of 1830EFPD. Table 2-1 of the AOR showed that the maximum predicted oxide thickness forU2C1 7 is 28.4 microns, well below the 100 micron limit. Operation at reduced power forlonger time would not significantly change the fuel rod corrosion rate, and there issubstantial margin to the 100 micron limit.80 n/a AREVA Lead Fuel Assembly (LFA) Re-evaluation was performed to determine impact, and all results were acceptable.compatibility Compatibility was verified by AREVA as documented in revised U2C17 Reload AnalysisReport (RAR).81 n/a WEC Lead Fuel Assembly (LFA) Re-evaluation was performed to determine impact, and all results were acceptable.compatibility Compatibility was verified by Westinghouse as documented in revised U2C17 RAR.82 n/a AREVA and WEC Chemistry Re-evaluation was performed to determine impact, and all results were acceptable.concurrence Concurrence for reduced power operation was performed by Westinghouse and AREVAas documented in revised U2C17 RAR.83 1.6.1 Reload Analysis Report (RAR) Re-analysis was performed to determine impact, and all results were acceptable. Revisedto address extended operation at reduced power.84 1.6.2 Engineering Change Package (ECP) Re-evaluation was performed to determine impact, and all results were acceptable.and 1OCFR5O.59 Review 10CFR50.59: New 10CFR50.59 review issued to address the extended operation atreduced power.ECP: Affected Section Change (ASC) issued to address the extended operation atreduced power.Page 15 Table 1SONGS Unit 2 Cycle 17 Reduced Power Operation -Summary of Impact Assessment ofReload and UFSAR Chapter 15 Safety AnalysesITEM CHECKLIST ITEMI# SAECTION) DESCRIPTION SUMMARY OF IMPACT ASSESSMENT# (UFSAR SECTION)85 2.1.2 Physics Input to FLCEA Drop Analysis No change to analysis is required. Power distributions at the same power level andand PFDTME Verification burnup are essentially identical. Analysis performed at multiple power levels.86 2.1.3 Physics Input to PLCEA Drop Analysis No change to analysis is required. Power distributions at the same power level andburnup are essentially identical. Analysis performed at multiple power levels.87 2.1.5 Physics Input to CEA Deviation Within No change to analysis is required. Power distributions at the same power level andCPC Deadband burnup are essentially identical. Analysis performed at multiple power levels.88 2.1.9 Refueling Boron Concentration No change to analysis is required. Analyzed at BOC, Mode 6.89 2.1.10 CIDSAL Physics Verification No change to analysis is required. Radial power distributions (at the same power leveland burnup) are essentially identical. T-inlet program remain unchanged.90 2.2.1 (15.10.4.1.3) CEA Misoperation -Deviation within No change to analysis is required. Power distributions at the same power level andDead Band (DWDB) burnup are essentially identical. Analysis performed at multiple power levels.91 2.2.2 (15.10.4.1.3) CEA Misoperation -PLR Drop -No change to analysis is required. Power distributions at the same power level andPower < 50% burnup are essentially identical. Event scenario is defined at < 50% Power. Scenarios at>50% power are discussed in "CEA Misoperation -Single Part Length CEA Drop (PLRDrop) -Power > 50%."92 2.2.3 (15.10.4.1.3) CEA Misoperation -Single Full Length No change to analysis is required. Power distributions at the same power level andCEA Drop (FLCEA Drop) burnup are essentially identical. Analyzed at multiple power levels.93 2.2.3 (15.10.4.1.3) CEA Misoperation -Single Part Length No change to analysis is required. Power distributions at the same power level andCEA Drop (PLCEA Drop) -Power > burnup are essentially identical. Analyzed at multiple power levels.50%94 2.2.3 (15.10.4.1.3) CEA Misoperation -Sub Group CEA No change to analysis is required. Power distributions at the same power level andDrop bumup are essentially identical. Analyzed at multiple power levels.95 2.2.4 AOPM Analysis No change to analysis is required. Power distributions at the same power level andburnup are essentially identical. Analyzed at multiple power levels.96 2.2.5 Transient Thermal Margin Summary No change to analysis is required. Analyzed at multiple power levels.Page 16 Table 1SONGS Unit 2 Cycle 17 Reduced Power Operation -Summary of Impact Assessment ofReload and UFSAR Chapter 15 Safety AnalysesITEM CHECKLIST ITEM DESCRIPTION SUMMARY OF IMPACT ASSESSMENT# (UFSAR SECTION)97 2.2.6 (15.10.3.1.1) Partial Loss of RCS Flow (PLOF) No change to analysis is required. Bounded by TLOF.98 2.2.6 (15.10.3.2.2) PLOF with Single Failure No change to analysis is required. Bounded by RCPSS.99 2.2.6 (15.10.3.2.1) Total Loss of Forced Reactor Coolant No change to analysis is required. The total loss of coolant flow event was analyzed for aFlow (TLOF) bounding scenario at 100% power and a MTC of +0.5x10-4 Ap/°F. This scenario boundsall powers from 0 to 100%.100 2.2.6 (15.10.3.3.3) TLOF with Single Failure No change to analysis is required. Bounded by RCPSS.101 2.2.7 CPC Dynamic Filter Analysis (including No change to analysis is required. The bounding events considered include CEAthe Pressurizer Spray Malfunction) -Withdrawal, Excess Load events, etc. As the system response time for these events hasnot changed, the dynamic filter analysis remains conservative.102 2.3.4 MSOUA Database and Files No change to analysis is required. The impact of RCS flow uncertainty changes has beencaptured in MSOUA Post-Processor.103 2.3.5 CPC Reload Data Block (RDB) Update No change to analysis is required. Reduced power has been implemented through CPCType 2 addressable constants, and not CPC RDB.104 2.3.6 MSOUA Post Processor Re-analysis was performed to determine impact, and all results were acceptable.Calculation has been revised for RCS flow uncertainty and the change in UNCERT fromthe FATES fuel performance analysis.105 2.3.7 Core Operating Limits Supervisory No change to analysis is required. Calculation is a prediction of operating margin at fullSystem (COLSS) & CPC Operating power. Reduced power increases operating margin.Margin Assessment106 2.3.8 COLSS Database No change to analysis is required. No changes are being made to the manner in whichCOLSS functions or responds. Therefore the cycle independent constants do not requirechange. The installed Primary AT power Block I constants were verified to be bounding.The cycle specific constants that are impacted by reduced power operation have beenaddressed in the COLSS As-built Database and Test Cases calculation.107 3.1.1 Full Core Load Map No change to analysis is required. Fuel management not changed.Page 17 Table ISONGS Unit 2 Cycle 17 Reduced Power Operation -Summary of Impact Assessment ofReload and UFSAR Chapter 15 Safety Analyses{ITEM[ CHECKLIST ITEM 1ITEM SECTION) DESCRIPTION SUMMARY OF IMPACT ASSESSMENT# (UFSAR SECTION)108 3.1.3 As-Built Models and Depletions Re-analysis was performed to determine impact, and all results were acceptable.Calculation was revised to address extended reduced power operation and to verify LeadFuel Assembly (LFA) compatibility operational requirements.109 3.1.4 CECOR Coefficients Impacted, and all results were acceptable. Calculation was revised to address extendedreduced power operation.110 3.1.5 As-Built Mini Depletion Re-analysis was performed to determine impact, and all results were acceptable.Calculation revised to address extended reduced power operation.111 3.1.6 Decay Heat No change to analysis is required. Decay heat was evaluated at end of Cycle 16condition. The calculation specifically addresses outage times past 99 days.112 3.1.7 Simulator Data Re-analysis was performed to determine impact, and all results were acceptable.Calculation revised to address extended reduced power operation.113 3.1.8 Special Nuclear Material Database No change to analysis is required. The change to Cycle 17 operating power will have noUpdate effect on prior cycle spent fuel and its characteristics.114 3.1.9 Plant Physics Data Book Re-analysis was performed to determine impact, and all results were acceptable. DataBook has been revised to address extended reduced power operation.115 3.1.10 Startup Physics Test Predictions Re-analysis was performed to determine impact, and all results were acceptable.Calculation has been revised to address changes to startup testing power plateaus.116 3.2.1 COLSS As-built Database and Test Re-analysis was performed to determine impact, and all results were acceptable.Cases Calculation has been revised to address extended reduced power operation impact on thecycle specific COLSS reload constants for DNBR & Linear Heat Rate (LHR) penalties.117 3.2.2 CEFAST Database Analysis Re-analysis was performed to determine impact, and all results were acceptable.Calculation has been revised to address extended reduced power operation impact on thecycle specific CPC reload constants for DNBR & Local Power Density (LPD) penalties.Page 18 Table 2SONGS Unit 2 Cycle 17 Reduced Power Operation -Summary of Impact Assessment ofCore Design and Monitoring Technical Specification Surveillance RequirementsI # Power Applicability and Summary of Impact Assessment forSurv # Surveillance Topic Surveillance Frequency I Performing at 68-70% Power3.1.3.1 Reactivity Balance Every 31 EFPD Steady state power (not full power) is required3.1.4.1 MTC within positive limit Prior to Mode 1 Performed at Hot Zero Power and projected to BOG 70%conditions3.1.4.2 MTC within negative limit Within 14 EFPD of peak Boron @ Peak boron occurs at BOG, -performed at Hot Zero PowerRTP and projected to HFP EOC conditions3.1.4.2 MTC within negative limit Within +/- 30 EFPD of Steady state power (not full power) is required; projected to2/3 of expected core burnup HFP EOC conditions3.2.2.1 CPC & COLSS Fxy > Between 40% -85% (i.e., prior to 68%-70% is within the power range required formeasured Fxy (CECOR) exceeding 85%) surveillance3.2.2.1 CPC & COLSS Fxy > Every 31 EFPD Steady state power (not full power) is requiredMeasured Fxy (CECOR)3.2.3.3 CPC Azimuthal Tilt > Every 31 EFPD Steady state power (not full power) is requiredMeasured Tilt (CECOR)3.3.1.2 RCS Flow in CPCs < Every 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> (not required until Procedure changed to perform surveillance at 68% powerMeasured RCS Flow 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> after power > 85% RTP)3.3.1.5 RCS Flow by calorimetric Every 31 days (not required until Procedure changed to perform surveillance at > 68%12 hours after power > 85% RTP) power, and to require additional margin when surveillanceis performed during extended operation at < 95% power3.3.1.11 CPC Shape Annealing Prior to exceeding 85% A minimum ASI change, rather than a specific power level,Matrix (SAM) Verification is requiredN/A Startup Test Activity Normally performed after reaching Results are already adjusted from actual test conditions toReduction Program full power RTP conditions as a part of the test methodReactivity BalanceHZP -HFPPage 19