ML101480555

License Amendment Request - Safety Limit Minimum Critical Power Ratio Change

ML101480555
Person / Time
Site:	Peach Bottom
Issue date:	05/27/2010
From:	Cowan P B Exelon Corp, Exelon Generation Co, Exelon Nuclear
To:	Document Control Desk, Office of Nuclear Reactor Regulation
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ML101480549	List: ML101480555
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{{#Wiki_filter:Exelon Nuclear 200 Exelon Way Kennett Sq ua re, PA 19348 www.exeloncorp.com Nuclear PROPRIETARY INFORMATION -WITHHOLD UNDER 10 CFR 2.390 10 CFR 50.90 May 27,2010 U.S.Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C.20555-0001 Peach Bottom Atomic Power Station, Unit 2 Renewed Facility Operating License No.DPR-44 NRC Docket No.50-277

Subject:

License Amendment Request-Safety Limit Minimum Critical Power Ratio Change In accordance with 10 CFR 50.90, Exelon Generation Company, LLC (Exelon)requests a proposed change to modify Technical Specification (TS)2.1.1 ("Reactor Core SLs").Specifically, this change incorporates revised Safety Limit Minimum Critical Power Ratios (SLMCPRs)due to the cycle specific analysis performed by Global Nuclear Fuel for Peach Bottom Atomic Power Station (PBAPS), Unit 2, Cycle 19.The proposed changes have been reviewed by the Peach Bottom Atomic Power Station Plant Operations Review Committee, and approved by the Nuclear Safety Review Board in accordance with the requirements of the Exelon Quality Assurance Program.In order to support the upcoming refueling outage at PBAPS, Unit 2, Exelon requests approval of the proposed amendment by September 1, 2010.Once approved, this amendment shall be implemented within 30 days of issuance.Additionally, there are no commitments contained within this letter.Attachment 1 contains the evaluation of the proposed changes.Attachments 2 and 3 provide the marked up TS page and the retyped TS page, respectively. Attachment 4 (letter from J.M.Downs (Global Nuclear Fuel)to J.Tusar (Exelon Generation Company, LLC), dated May 6, 2010)specifies the new SLMCPRs for PBAPS, Unit 2, Cycle 19.Attachment 4 contains information proprietary to Global Nuclear Fuel.Global Nuclear Fuel requests that the document be withheld from public disclosure in accordance with 10 CFR 2.390(b)(4). An affidavit supporting this request is also contained in Attachment 4.Attachment 5 contains a non-proprietary version of the Global Nuclear Fuel document.Attachment 6 contains the power/flow map for Cycles 18 and 19.In accordance with 10 CFR 50.91, Exelon is notifying the State of Pennsylvania of this application for license amendment by transmitting a copy of this letter and its attachments to the designated State Official.Attachment 4 transmitted herewith contains Proprietary Information. When separated from attachments, this document is decontrolled. License Amendment Request Safety Limit Minimum Critical Power Ratio Change May 27,2010 Page 2 Should you have any questions concerning this letter, please contact Tom Loomis at (610)5510.I declare under penalty of perjury that the foregoing is true and correct.Executed on the 2yth of May 2010.Respectfully, f)4 1f _Pamela B.Cowan Director, Licensing&Regulatory Affairs Exelon Generation Company, LLC Attachments: 1)Evaluation of Proposed Changes 2)Markup of Technical Specifications Page 3)Retyped Technical Specifications Page 4)Proprietary Version of Global Nuclear Fuel Letter 5)Non-Proprietary Version of Global Nuclear Fuel Letter 6)Power/Flow Map for Cycles 18 and 19 cc: USNRC Region I, Regional Administrator USNRC Senior Resident Inspector, PBAPS USNRC Project Manager, PBAPSR.R.Janati, Commonwealth of Pennsylvania S.T.Gray, State of Maryland Attachment 1 Peach Bottom Atomic Power Station, Unit 2 Renewed Facility Operating License No.DPR-44 Evaluation of Proposed Changes ATTACHMENT 1 CONTENTS

SUBJECT:

Safety Limit Minimum Critical Power Ratio (SLMCPR)Change 1.0

SUMMARY

DESCRIPTION

2.0 DETAILED

DESCRIPTION

4.0 REGULATORY EVALUATION

4.1 Applicable

Regulatory Requirements/Criteria

4.2 Precedents

4.3 No Significant Hazards Consideration

5.0 ENVIRONMENTAL

CONSIDERATION

6.0 REFERENCES

License Amendment Request Safety Limit Minimum Critical Power Ratio Page 1 1.0

SUMMARY

DESCRIPTION This evaluation supports a request to amend Renewed Facility Operating License No.DPR-44 for Peach Bottom Atomic Power Station (PBAPS), Unit 2.The proposed change modifies Technical Specification (TS)2.1.1 ("Reactor Core SLs").Specifically, this change incorporates revised Safety Limit Minimum Critical Power Ratios (SLMCPRs)due to the cycle specific analysis performed by Global Nuclear Fuel for Peach Bottom Atomic PowerStation(PBAPS), Unit 2, Cycle 19.2.0 DETAILED DESCRIPTION The proposed change involves revising the SLMCPRs contained in TS 2.1.1 for two recirculation loop operation and single recirculation loop operation. The SLMCPR value forloop operation is being changed from 2 1.07 to 2 1.10.The SLMCPR value for single-loop operation is being changed from 2 1.09 to 2 1.14.Marked up Technical Specification page 2.0-1 showing the requested changes is provided in Attachment 2.

3.0 TECHNICAL EVALUATION

The proposed TS change will revise the SLMCPRs contained in TS 2.1.1 for two recirculation loop operation and single recirculation loop operation to reflect the changes in the cycle specific analysis performed by Global Nuclear Fuel for PBAPS, Unit 2, Cycle 19.The new SLMCPRs are calculated using NRC-approved methodology described in24011-P-A,"General Electric Standard Application for Reactor Fuel," Revision 16.A listing of the associated NRC-approved methodologies for calculating the SLMCPRs is provided in Section 1.0 ("Methodology") of Attachment 4.The SLMCPR analysis establishes SLMCPR values that will ensure that during normal operation and during abnormal operational transients, at least 99.9%of all fuel rods in the core do not experience transition boiling if the limit is not violated.The SLMCPRs are calculated to include cycle specific parameters and, in general, are dominated by two key parameters: 1)flatness of the core bundle-by-bundle MCPR distribution, and 2)flatness of the bundle pin-by-pinfactor distribution. Information to support the cycle specific SLMCPRs is included in Attachment 4.That attachment summarizes the methodology, inputs, and results for the change in the SLMCPRs.The PBAPS, Unit 2 Cycle 19 core will consist of GE14 and GNF2 fuel types.Attachment 6 contains the power/flOW map for Cycles 18 and 19.No plant hardware or operational changes are required with this proposed change.

4.0 REGULATORY EVALUATION

4.1 Applicable

Requlatory Requirements/Criteria 10 CFR 50.36,"Technical specifications," paragraph (c)(1), requires that power reactor facility TS include safety limits for process variables that protect the integrity of certain physical barriers that guard against the uncontrolled release of radioactivity. The fuel cladding integrity License Amendment Request Safety Limit Minimum Critical Power Ratio Page 2 SLMCPR is established to assure that at least 99.9%of the fuel rods in the core do not experience boiling transition during normal operation and abnormal operating transients. Thus, the SLMCPR is required to be contained in TS.4.2 Precedents The NRC has approved similar SLMCPR changes for a number of plants: 1)Letter from M.H.Chernoff (U.S.Nuclear Regulatory Commission) to K.W.Singer (Tennessee Valley Authority),"Browns Ferry Nuclear Plant, Unit1-Issuance of Amendment Regarding Cycle-Specific Safety Limit Minimum Critical Power Ratio (TAC NO.MD1721)(TS-455)," dated February 6,2007 2)Letter from J.Kim (U.S.Nuclear Regulatory Commission) to Site Vice President (Entergy Nuclear Operations, Inc.),"Pilgrim Nuclear Power Station-Issuance of Amendment RE: Technical Specification Change Concerning Safety Limit Minimum Critical Power Ratio (TAC NO.ME0241)," dated March 26, 2009 3)Letter from J.Wiebe (U.S.Nuclear Regulatory Commission) to C.Pardee (Exelon Generation Company, LLC),"Quad Cities Nuclear Power Station, Units 1 and2-Issuance of Amendments RE: Safety Limit Minimum Critical Power Ratio (TAC NOS.MD7374 AND MD7375)," dated February 28,2008 4)Letter from C.Lyon (U.S.Nuclear Regulatory Commission) to Vice President, Operations (Entergy Operations, Inc.),"Grand Gulf Nuclear Station, Unit1-Issuance of Amendment RE: Change totheMinimum Critical Power Ratio Safety Limit (TAC NO.ME2474)," dated March 25, 2010 4.3 No Significant Hazards Consideration Exelon Generation Company, LLC (Exelon)has evaluated whether or not a significant hazards consideration is involved with the proposed amendment by focusing on the three standards set forth in 10 CFR 50.92,"Issuance of amendment," as discussed below: 1.Does the proposed amendment involve a significant increase in the probability or consequences of an accident previously evaluated? Response: No.The derivation of the cycle specific Safety Limit Minimum Critical Power Ratios (SLMCPRs)for incorporation into the Technical Specifications (TS), and their use to determine cycle specific thermal limits, has been performed using the methodology discussed in NEDE-24011-P-A,"General Electric Standard Application for Reactor Fuel," Revision 16.The basis of the SLMCPR calculation is to ensure that during normal operation and during abnormal operational transients, at least 99.9%of all fuel rods in the core do not experience transition boiling if the limit is not violated.The new SLMCPRs preserve the License Amendment Request Safety Limit Minimum Critical Power Ratio Page 3 existing margin to transition boiling.The MCPR safety limit is reevaluated for each reload using NRC-approved methodologies. The analyses for Peach Bottom Atomic Power Station (PBAPS), Unit 2, Cycle 19 have concluded that a two loop MCPR safety limit of1.10, based on the application of Global Nuclear Fuel's NRC-approved MCPR safety limit methodology, will ensure that this acceptance criterion is met.For single-loop operation, a MCPR safety limit of1.14 also ensures that this acceptance criterion is met.The MCPR operating limits are presented and controlled in accordance with the PBAPS, Unit 2 Core Operating Limits Report (COLR).The requested Technical Specification changes do not involve any plant modifications or operational changes that could affect system reliability or performance or that could affect the probability of operator error.The requested changes do not affect any postulated accident precursors, do not affect any accident mitigating systems, and do not introduce any new accident initiation mechanisms. Therefore, the proposed TS changes do not involve a significant increase in the probability or consequences of an accident previously evaluated. 2.Does the proposed amendment create the possibility of a new or different kind of accident from any accident previously evaluated? Response: No.The SLMCPR is a TS numerical value, calculated to ensure that during normal operation and during abnormal operational transients, at least 99.9%of all fuel rods in the core do not experience transition boiling if the limit is not violated.The new SLMCPRs are calculated using NRC-approvedmethodologydiscussed in NEDE-24011-P-A,"General Electric Standard Application for Reactor Fuel," Revision 16.The proposed changes do not involve any new modes of operation, any changes to setpoints, or any plant modifications. The proposed revised MCPR safety limits have been shown to be acceptable for Cycle 19 operation. The core operating limits will continue to be developed using NRC-approved methods.The proposed MCPR safety limits or methods for establishing the core operating limits do not result in the creation of any new precursors to an accident.Therefore, this change does not create the possibility of a new or different kind of accident from any previously evaluated. 3.Does the proposed amendment involve a significant reduction in a margin of safety?Response: No.There is no significant reduction in the margin of safety previously approved by the NRC as a result of the proposed change to the SLMCPRs.The new SLMCPRs are calculated using methodology discussed in NEDE-24011-P-A,"General Electric Standard Application for Reactor Fuel," Revision 16.The SLMCPRs ensure that during normal operation and during abnormal operational transients, at least 99.9%of all fuel rods in the core do not experience transition boiling if the limit is not violated, thereby preserving the fuel cladding integrity. Therefore, the proposed TS changes do not License Amendment Request Safety Limit Minimum Critical Power Ratio Page 4 involve a significant reduction in the margin of safety previously approved by the NRC.Based on the above, Exelon Generation Company, LLC, concludes that the proposed amendment does not involve a significant hazards consideration under the standards set forth in 10 CFR 50.92(c), and, accordingly, a finding of no significant hazards consideration is justified.

4.4 Conclusions

In conclusion, based on the considerations discussed above, (1)there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2)such activities will be conducted in compliance with the Commission's regulations, and (3)the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.5.0 ENVIRONMENTAL CONSIDERATION A review has determined that the proposed amendment would change a requirement with respect to installation or use of a facility component located within the restricted area, as defined in 10 CFR 20, or would change an inspection or surveillance requirement. However, the proposed amendment does not involve (i)a significant hazards consideration, (ii)a significant change in the types or significant increase in the amounts of any effluent that may be released offsite, or (iii)a significant increase in individual or cumulative occupational radiation exposure.Accordingly, the proposed amendment meets the eligibility criterion for categorical exclusion set forth in 10 CFR 51.22(c)(9). Therefore, pursuant to 10 CFR 51.22(b), no environmental impact statement or environmental assessment need be prepared in connection with the proposed amendment.

6.0 REFERENCES

1)NEDE-24011-P-A,"General Electric Standard Application for Reactor Fuel," Revision 16. ATTACHMENT 2 Markup of Technical Specifications Page Revised TS Page 2.0-1 (Unit 2) o ,()'\j SLs 2.0 2.0 SAFETY LIMITS (SLs)2.1 SLs 2.1.1 Reactor Core SLs 2.1.1.1 With the reactor steam dome pressure<785 psig or core flow<10%rated core flow: THERMAL POWER shall be25%RTP.2.1.1.2 With the reactor steam dome pressure785 psig and core flow10% flow' >1.07 loop operation sing e recirculation loop operation. 2.1.1.3 Reactor vessel water level shall be greater than the top of active irradiated fuel.2.1.2 Reactor Coolant SYstem Pressure SL Reactor steam dome pressure shall be1325 psig.2.2 SL Violations With any SL violation, the following actions shall be completed within 2 hours: 2.2.1 Restore compliance with all SLs;and 2.2.2 Insert all insertable control rods.(continued) PBAPS UN IT 2 2.0-1 Amendment No.259 ATTACHMENT 3 Retyped Technical Specifications Page Revised TS Page 2.0-1 (Unit 2) SLs 2.0 2.0 SAFETY LIMITS (SLs)2.1 SLs 2.1.1 Reactor Core SLs 2.1.1.1 With the reactor steam dome pressure<785 psig or core flow<10%rated core flow: THERMAL POWER shall be s 25%RTP.2.1.1.2 With the reactor steam dome pressure785 psig and core flow10%rated core flow: MCPR shall be1.10 for two recirculation loop operation or1.14 for single recirculation loop operation. 2.1.1.3 Reactor vessel water level shall be greater than the top of active irradiated fuel.2.1.2ReactorCoolant System pressure SL Reactor steam dome pressure shall be s 1325 psig.2.2 SL Violations* With any SL violation, the following actions shall be completed within 2 hours: 2.2.1 Restore compliance with all SLs;and 2.2.2 Insert all insertable control rods.(continued) PBAPS UNIT 2 2.0-1 Amendment No. ATTACHMENT 5 Non-Proprietary Version of Global Nuclear Fuel Letter GNF NON-PROPRIETARY INFORMATION Class I GNF Attachment May 2010 GNF-0000-01 10-4753-RO-NPeDRFSection:0000-0110-4753 RO GNF Additional Information Regarding the Requested Changes to the Technical Specification SLMCPR Peach Bottom2C 19 Peach Bottom2C 19 Verified Information Page 1 of25 GNF NON-PROPRIETARY INFORMATION Class I GNF Attachment Proprietary Information Notice This document is the GNF version of the GNF proprietary report.From the GNF proprietary version, the information denoted as GNF proprietary (enclosed in double brackets)was deleted to generate this version.Important Notice Regarding Contents of this Report Please Read Carefully The information contained in this document is furnished solely for the purpose(s) stated in the transmittal letter.The only undertakings of GNF-A with respect to information in this documentarecontained in the contracts between GNF-A and its customers or participating utilities, and nothing contained in this document shall be construed as changing that contract.The use of this information by anyone for any purpose other than that for which it is intended is not authorized; and with respect to any unauthorized use, GNF-A makes no representation or warranty, and assumes no liability as to the completeness, accuracy, or usefulness of the information contained in this document.Copyright 2010.Global Nuclear Fuel-Americas, LLC, All Rights Rcserycd Proprietary Information Notice Verified Information Page 2 of25 GNF NON-PROPRIETARY INFORMATION Class I GNF Attachment Table of Contents 1.0 METHODOLOGY 4 2.0 DiSCUSSiON 4 2.J.MAJOR CONTRlm;TORS TO SLMCPR CII.-\NGE2.2.DEVIATIONS IN NRC-AI'I'ROVED UNCERTAINHES 5 2.2./.R*Fa(;/ur 5 2.2.2.Core nul\'Rate ami Randum E.!Tectilte TIP Reading 5 2.2.3.LPRAf Update Interval alld Ca/culated Bundle Power 6 2.3.DEI'AR'll.;R£ FROM NRC-ApPROVED METHOIXJL(X:;Y 7 2.4.FI*E!.AXIAL POWER SII.WE PEN.*\I.TY 7 2.5.METIIOIX)UXiY RESTRICTIONS 8 2.6.MINIMI;M CORE Fr.ow CO"I)I1'I01"< 8 2.7.LIM rI1NG CONTROL ROD PXlTERNS 9 2.8. MONITORING SYSTEM 9 2.9.PO\\'ERlFr..OW MAI'9 2.10.CORE LOADING DIAGRA:-.I 9 2.11.FIGI iRE REFERENCES <)2.12.ADf)(TIOI'L\L SLMCPR LICENSING CONDrnONS 10 2.13.SUM1vL\RY 10

3.0 REFERENCES

1 J List of Figures FIGI iRE 1.CURRENT CYCLE CORE LOADING DJAGRA"'1 12 FIGUIU: 2. CYCLE CORIo LOADING DIAGRAM 13 FIGI'RE 3.FIGI iRE-4.1 FROM NEDC-3260 I P-A 14 FIGliRE 4.FIOURE 1II.5-1 FROM NEDC-32601 P-A 15 FIGl.*RE 5.FICitlRE IH.5-2 NEDC-3260IP-A 16 List of Tables T\BLE I.DESCRIPTIO" OF CORE..17 T.4.UU: 2.SLMCPR CALCULA'!10N MEnloIXlLCXiIES 18 TAllLE 3.MONTE CARLO CALCUL\TED SLMCPR\is.ESTIMATE 19 NO!':-POWER DISTRIBU'110N U1\(.TR*(',\INTIES 21 TABLE 5.POWER DISTRIBUTION UNCERTAI1\TlES 23 TABLE 6.CRme\!.POWER UNCERTAINTIES 25 Table of Contents Verified Information Page 3 of25 GNF NON-PROPRIETARY INFORMATION Class I GNF Attachment

1.0 Methodology

GNF performed the Peach Bottom 2 C19 Safety Limit Minimum Critical Power Ratio (SLMCPR)calculation in accordance to NEDE-240 II-P-A"General Electric Standard Application for Reactor Fuel" (Revision 16)using the following NRC-approved methodologies and uncertainties:

• NEDC-3260 I P-A"Methodology and Uncertainties for Safety Limit MCPR Evaluations" (August 1999).*NEDC-32694P-A"Power Distribution Uncertainties for Safety Limit MCPR Evaluations" (August 1999).*NEDC-32505P-A"R-Factor Calculation Method for GEl I, GE12 and GE13 Fuel" (Revision 1, July 1999)*NEDO-I0958-A"General Electric BWR Thermal Analysis Basis (GET AB): Data, Correlation and Design Application" (January 1977).Table 2 identifies the actual methodologies used for the previous cycle and the current cycle SLMCPR calculations.

2.0 Discussion

In this discussion, the TLO nomenclature is used for two recirculation loops in operation, and the SLO nomenclature is used for one recirculation loop in operation. 2.1.Major Contributors to SLMCPR Change In general, the calculated safety limit is dominated by two key parameters: (I)flatness of the core bundle-by-bundle MCPR distribution, and (2)flatness of the bundle pin-by-pinfactor distribution. Greater flatness in either parameter yields more rods susceptible to boiling transition and thus a higher calculated SLMCPR.MIP (MCPR Importance Parameter) measures the core bundle-by-bundle MCPR distribution and RIP (R-factor Importance Parameter) measures the bundle pin-by-pin power/R-factor distribution. The impact of the fuel loading pattern on the calculated TLO SLMCPR using rated core power and rated core flow conditions has been correlated to the parameter MIPRIP, which combines the MIP and RIP values.Table 3 presents the MIP and RIP parameters for the previous cycle and the current cycle along with the TLO SLMCPR estimate using the MlPRIP correlation. If the minimum core flow case is applicable, the TLO SLMCPR estimate is also provided for that case although the MlPRIP correlation is only applicable to the rated core flow case.This is done only to provide some reasonable assessment basis of the minimum core flow case trend.In addition, Table 3 presents Methodology Verified Information Page 4 of25 GNF NON-PROPRIETARY INFORMATION Class I GNF Attachment estimated impacts on the TLO SLMCPR due to methodology deviations, penalties, and/or uncertainties deviations from approved values.Based on the MIPRlP correlation and any impacts due to deviations from approved values, a final estimated TLO SLMCPR is determined. Table 3 also provides the actual calculated Monte Carlo SLMCPRs.Given the bias and uncertainty in the MIPRIP correlation [[]]and the inherent variation in the Monte Carlo results[[n, the change in the Peach Bottom 2 CI9 calculated Monte Carlo TLO SLMCPR using rated core power and rated core flow conditions is consistent with the corresponding estimated TLO SLMCPR value.2.2.Deviations in NRC-Approved Uncertainties Tables 4 and 5 provide a list of NRC-approved uncertainties along with values actually used.A discussion of deviations from these NRC-approved values follows;all of which are conservative relative to NRC-approved values Also, estimated impact on the SLMCPR is provided in Table 3 for each deviation. 2.2.1.R-Factor At this time, GNF has generically increased the GEXL R-Factor uncertainty from[[]]to account for an increase in channel bow due to the emerging unforeseen phenomena called control blade shadow corrosion-induced channel bow, which is not accounted for in the channel bow uncertainty component of the approved R-Factor uncertainty. The step"(J RPEAK" in Figure 4.I from NEDC-32601 P-A, which has been provided for convenience in Figure 3 of this attachment, is affected by this deviation. Reference 4 technically justifies that a GEXL R-Factor uncertainty of[[]]accounts for a channel bow uncertainty of up to[[]].Peach Bottom 2 has experienced control blade shadow corrosion-induced channel bow to the extent that an increase in the NRC-approved R-Factor uncertainty [[]]is deemed prudent to address its impact.Accounting for the control blade shadow corrosion-induced channel bow, the Peach Bottom2C 19 analysis shows an expected channel bow uncertainty of[[1l.which is bounded by a GEXL R-Factor uncertainty of[[n Thus the use of a GEXLFactor uncertainty of[[]]adequately accounts for the expected control blade shadow corrosion-induced channel bow for Peach Bottom2C 19.2.2.2.Core Flow Rate and Random Effective TIP Reading At this time, GNF has not been able to show that the NRC-approved process to calculate the SLMCPR only at the rated core power and rated core flow condition is adequately bounding relative to the SLMCPR calculated at rated core power and minimum core flow, see Reference 5.The minimum core flow condition can be more limiting due to the control rod pattern used.GNF has modified the NRC-approved process for determining the SLMCPR to include analyses at the rated core power and minimum licensed core flow point in addition to analyses at the rated core power and rated core flow point.GNF believes this modification is conservative and may in the future provide justification that the original NRC-approved process is adequately Discussion Verified Information Page 5 of25 GNF NON-PROPRIETARY INFORMATION Class I GNF Attachment bounding.For the TLO calculations performed at 82.8%core flow, the approved uncertainty values for the core flow rate (2.5%)andthe random effective TIP reading (1.2%)are conservatively adjusted by dividing them by 82.8/100.The steps"()CORE FLOW" and"(j TIP (INSTRUMENT)" in Figure 4.1 from NEDC-3260 IP-A, which has been provided for convenience in Figure 3 of this attachment, are affected by this deviation, respectively Historically, these values have been construed to be somewhat dependent on the core flow conditions as demonstrated by the fact that higher values have always been used when performing SLO calculations. It is for this reason that GNF determined that it is appropriate to consider an increase in these two uncertainties when the core flow is reduced.The amount of increase is determined in a conservative way.For both parameters it is assumed that the absolute uncertainty remains the same as the flow is decreased so that the percentage uncertainty increases inversely proportional to the change in core flow.This is conservative relative to the core flow uncertainty since the variability in the absolute flow is expected to decrease somewhat as the flow decreases. For the random effective TIP uncertainty, there is no reason to believe that the percentage uncertainty should increase as the core flow decreases for TLO.Nevertheless, this uncertainty is also increased as is done in the more extreme case for SLO primarily to preserve the historical precedent established by the SLO evaluation. Note that the TLO condition is different than the SLO condition because for TLO there is no expected tilting of the core radial power shape.The treatment of the core flow and random effective TIP reading uncertainties is based on the assumption that the signal to noise ratio deteriorates as core flow is reduced.GNF believes this is conservative and may in the future provide justification that the original uncertaintiesflow dependent) are adequately bounding.The core flow and random TIP reading uncertainties used in the SLO minimum core flow SLMCPR analysis remain the same as in the rated core flow SLO SLMCPR analysis because these uncertainties (which are substantially larger than used in the TLO analysis)already account for the effects of operating at reduced core flow.2.2.3.LPRM Update Interval and Calculated Bundle Power To adequately address the LPRM update/calibration interval in the Peach Bottom 2 Technical Specifications, GNf has increased the LPRM update uncertainty in the SLMCPR analysis for Peach Bottom2C 19.The approved uncertainty values for the contribution to bundle power uncertainty due to LPRM update[[]]and the resulting total uncertainty in calculated bundle power[[]]are conservatively increased. The steps"0'TIP (INSTRUMENT)" and"0'BUNDLE (MODEL)" in Figure 4.1 from NEDC-32601P-A, which has been provided for convenience in Figure 3 of this attachment, are affected by this deviation. Discussion Verified Information Page 6 of25 GNP NON*PROPRJETARY JNFORMATION Class I GNF Attachment [[]]The total bundl e power uncertainty is a function of the LPRM update uncertainty as detailed in Section 3.3 of32694P-A.2.3.Departure from NRC-Approved Methodology No departures fromNRC-approvedmethodologies were used in the Peach Bottom 2 C19 SLMCPR calculations. 2.4.Fuel Axial Power Shape Penalty At this time, GNF has detennined that higher uncertainties and non-conservative biases in the GEXL correlations for the various types of axial power shapes (i.e., inlet, cosine, outlet and double hump)could potentially exist relative to the NRC-approved methodolo!,'Y values, see References 3, 6, 7 and 8.The following table identifies, by marking with an"X", this potential for each GNF product line currently being offered:[{II Axial bundle power shapes corresponding to the limiting SLMCPR control blade patterns are detennined using the PANACEA 3D core simulator. These axial power shapes are classified in accordance to the following table:[[Discussion Verified Information Page 7 of25 GNF NON-PROPRIETARY INFORMATION Class I GNF Attachment \I If the limiting bundles in the SLMCPR calculation exhibit an axial power shape identified by this table, GNF penalizes the GEXL critical power uncertainties to conservatively account for the impact of the axial power shape.Table 6 provides a list of the GEXL critical power uncertainties detennined in accordance to the NRC-approved methodology contained in NEDE-24011-P-A along with values actually used.For the limiting bundles, the fuel axial power shapes in the SLMCPR analysis were examined to determine the presence of axial power shapes identified in the above table.These power shapes were not found;therefore, no power shape penalties were applied to the calculated Peach Bottom 2 C19 SLMCPRvalues. 2.5.Methodology Restrictions The four restrictions identified on Page 3 of NRC's Safety Evaluation relating to the General Electric Licensing Topical Reports NEDC-32601 P, NEDC-32694P, and Amendment 25 to NEDE-240]I-P-A (March I],]999)are addressed in References 1,2,3, and 9.No new GNF fuel designs are being introduced in Peach Bottom 2 C19;therefore, the32505P-A statement"...if new fuel is introduced, GENE must confirm that the revised R-Factor method is still valid based on new test data" is not applicable. 2.6.Minimum Core Flow Condition For Peach Bottom2C 19, the minimum core flow SLMCPR calculation perfonned at 82.8%core flow and rated core power condition was limiting as compared to the rated core flow and rated core power condition. At low core flows, the search spaces for the limiting rod pattern and the nominal rod pattern are essentially the same.Additionally, the condition that MIP ([]], establishes a reasonably bounding limiting rod pattern.Hence, the rod pattern used to calculate the SLMCPR at 100 percent rated power/82.8 percent rated flow reasonably assures that at least 99.9%of the fuel rods in the core would not be expected to experience boiling transition during nonnal operation or anticipated operational occurrences Discussion Verified Information Page 80f25 GNF NON*PROPRIET ARY INFORMATION Class I GNF Attachment during the operation of Peach Bottom2C 19 Consequently, the SLMCPR value calculated from the 82.8%core flow and rated core power condition limiting MCPR distribution reasonably bounds this mode of operation for Peach Bottom 2 C 19.2.7.Limiting Control Rod Patterns The limiting control rod patterns usedtocalculate the SLMCPR reasonably assures that at least 99.9%of the fuel rods in the core would not be expected to experience boiling transition during normal operation or anticipated operational occurrences during the operation of Peach Bottom 2 C19.2.8.Core Monitoring System For Peach Bottom 2 C 19, the 3DMonicore system will be used as the core monitoring system.2.9.Power/Flow Map The utility has provided the current and previous cycle power/flow map in a separate attachment. 2.10.Core Loading Diagram Figures 1 and 2 provide the core-loading diagram for the current and previous cycle respectively, which are the Reference Loading Pattern as defined by NEDE-24011-P-A. Table I provides a description of the core.2.11.Figure References Figure 3 is Figure 4.1 from NEDC-32601 P-A.Figure 4 is Figure III.5-1 from NEDC-3260IP-A. Figure 5 is Figure 111.5-2 from NEDC-32601 P-A.Discussion Verified Information Page 9 of25 GNF NON-PROPRIETARY INFORMATION Class I GNF Attachment 2.12.Additional SLMCPR Licensing Conditions For Peach Bottom 2 C19, no additional SLMCPR licensing conditions are included in the analysis.2.13.Summary The requested changes to the Technical Specification SLMCPR values are 1.10 for TLO and 1.14 for SLO for Peach Bottom 2 C 19.Discussion Verified Information Page 10 of25 GNF NON-PROPRIETARY INFORMATION Class I GNF Attachment

3.0 References

I.Letter, Glen A.Watford (GNF-A)to U.S.Nuclear Regulatory Commission Document Control Desk with attention to R.Pulsifer (NRC),"Confirmation of lOx 10 Fuel Design Applicability to Improved SLMCPR, Power Distribution and R-Factor Methodologies", FLN-2001-016, September 24,2001.2.Letter, Glen A.Watford (GNF-A)to U.S.Nuclear Regulatory Commission Document Control Desk with attention to 1.Donoghue (NRC),"Confirmation of the Applicability of the GEXL 14 Correlation and Associated R-Factor Methodology for Calculating SLMCPR Values in Cores Containing GEI4 Fuel", FLN-2001-017, October 1,2001.3.Letter, Glen A.Watford (GNF-A)to U,S.Nuclear Regulatory Commission Document Control Desk with attention to Joseph E.Donoghue (NRC),"Final Presentation Material for GEXL Presentation -February I I, 2002", FLN-2002-004, February 12, 2002.4, Letter, John F.Schardt (GNF-A)to U.S.Nuclear Regulatory Commission Document Control Desk with attention to Mel B.Fields (NRC),"Shadow Corrosion Effects on SLMCPR Channel Bow Uncertainty", FLN-2004-030, November 10,2004.5, Letter, Jason S.Post (GENE)to U.S.Nuclear Regulatory Commission Document Control Desk with attention to Chief, Information Management Branch, et a1.(NRC),"Part 21 Final Report: Non-Conservative SLMCPR", MFN 04-108, September 29,2004.6.Letter,Glen A.Watford (GNF-A)to U.S.Nuclear Regulatory Commission Document Control Desk with attention to Alan Wang (NRC),"NRC Technology UpdateProprietary Slides-July 31-August 1,2002", FLN-2002-0 IS, October 31,2002.7.Letter, Jens G.Munthe Andersen (GNF-A)to U.S.Nuclear Regulatory Commission Document Control Desk with attention to Alan Wang (NRC),"GEXL Correlation for IOXIO Fuel", FLN-2003-005, May 31,2003.8, Letter, Andrew A.Lingenfelter (GNF-A)to U.S.Nuclear Regulatory Commission Document Control Desk with cc to MC Honcharik (NRC),"Removal of Penalty Being Applied to GE 14 Critical Power Correlation for Outlet Peaked Axial Power Shapes", FLN-2007-03I, September 18,2007.9.Letter, Andrew A.Lingenfelter (GNF-A)to U.S.Nuclear Regulatory Commission Document Control Desk with cc to MC Honcharik (NRC),"GNF2 Advantage Generic Compliance with NEDE-24011-P-A (GESTAR II), NEDC-33270P, Revision 2, June 2009 and GEXL Correlation for GNF2 Fuel, NEDC-33292P, Revision 3, June 2009", MFN 09-436, June 30, 2009.References Verified Information Page II of25 GNF NON-PROPRIETARY INFORMATION Class I GNF Attachment Figure I.Current Cycle Core Loading Diagram- [!]1!l1!J1!I[][!] rn I!l [!][[][][El[i][I](j][[J I I Fuel Type RGE 14-PIODNAB416-150Z-IOOT*150. T6-2908 14-PIODNAB417-13G60*IOOT-150-T6-2909 5-1 SGZ-looT-ISO-T6-29 10 EOE 14-I'IODNAB4 16-1 50Z-looT-150-T6-29 1 1 G**GE 14-PWDNAB409-1 5Gl*lOOT-150-T6-2913 HONF2-PlOfXi2B406-12G6.0-100T2-150-T6-3337 TGNl:2-PIOIXi2B393-15GZ-IOOT2-IS(J-T6-.B34 .1GNF2*PIODG2B388-6G80/6G7.0206.0-IOOT2-ISO-T6-3336 Figure 1.Current Cycle Core Loading Diagram K=(i NF2-P IOIXi2B392-ISGZ-100T2-1 S()*T6-3335 LfiEI4*PIODNAB420*lJGZ*IOOT*150*T6*3097 M"GEI4-PIODNAB416-15GZ-IOOT-150-16-3098 N-GEI4-PIODNAB416-15GZ-100T-150-T6-2911 OGEI4-PIODNAB411.-15GZ-100T-150-T6-J099 P=G E14*1'1 ODNAB409-15Gl-lOOT-I 50-16-2913 QwGNF2-1'IO[)G2B388-6GIW i (,(}7.0/2G6.0-1 00T2-150*T6-3336 RGNF2-PIOIXi2B3'.12-15GZ-100T2-150-T6-3335 SGNF2-P I O\X,2B392-15GZ-1 OOT2-1 so*T6-3332 Page 12 of25 GNF NON-PROPRIETARY INFORMATION Class I GNF Attachment Figure 2.Previous Cycle Core Loading Diagram 60 58 56 54 52 50 48 46 44 42 40 38 36 34 32 30 28 26 24 22 20 18 16 14 12 10 8 6 4 213579 11 13151719 212325 27 29 31 33 35 37 39 41 43 45 47 49 51 53 555759 Fuel Type 5-16GZ-100T-150-T6-2790 B"'OEI4-PI0DNAB417-13G6,O ...IOOT-150...T6*2909!"'OE 14-PIODNAB420-13G1,-l00T-150*T6-3097 CGEI4-PIODNAB415-15G1,-100T-150-T6-2910 F'GE 14-PIODNAB416-J SOZ-IOOT-l 50-1'6-3098 D"GEI4-PJODNAB416-15GZ-l00T-ISO-T6-291 I K'OEI4-PIODNAB416-15GZ-I00T-1.50-T6-2911 E*GE 14-1'IODNAB416-15GZ-IOOT-ISO-T6-2912 L'GE I 4-PlODNAB4 I J-I SGZ-IOO'l'-150-T6-3099 F=Ci E 14-PIODNAB409-15GZ-IOOT-150-T6-29 13 M'"'GEI4-PIODNAB409-15GZ-IOOT-150-T6-2913 (J"GEI4-PlODNAB415-15GZ-100T-150-T6-2789 Figure 2.Previous Cycle Core Loading Diagram Page 13 of25 GNF NON-PROPRIETARY INFORMATION Class I GNF Attachment Figure 3.Figure 4.1 from NEDC-3260IP-A Figure 3.Figure 4.1 from NEDC-3260 IP-APage 14 of25 GNF NON-PROPRIETARY INFORMATION Class I GNF Attachment [[Figure 4.Figure 111.5-1 from NEDC-32601P-A Figure 4.Figure III.5-1 from NEDC-3260IP-A ]]Page 15 of25 GNF NON-PROPRJET ARY INFORMA nON Class I GNF Attachment Figure 5.Figure 111.5-2 from NEDC-32601P-A Figure 5.Figure III.5-2 from NEDC-32601 P-APage 16 of25 GNF NON-PROPRIETARY INFORMATION Class 1 GNF Attachment Table 1.Description of Core Previous Cycle Previous Cycle Rated Current Cycle Current Cycle Rated Description Minimum Core Flow Core Flow Limiting Minimum Core Flow Core Flow Limiting Limiting Case Case Limiting Case Case Number of Bundles in the 764 764 Core Limiting Cycle Exposure Point (i.e.EOC EOC EDC EOC BOC/MOC/EOC) Cycle Exposure at Limiting Point 13400 13400 12700 13300 (MWd/STU)%Rated Core Flow 82.8 100 82.8 100 Reload Fuel Type GE14 GNF2 Latest Reload Batch 35.6 35.6 Fraction,%Latest Reload Average Batch Weight%4.14 3.94 Enrichment Core Fuel Fraction: GEI4 1.000 0.644 GNF2 0.000 0.356 Core Average Weight%4.15 4.07 Enrichment Table 1.Description of Core Verified[nfoffilation Page 17 of25 GNF NON-PROPRIETARY INFORMATION Class I GNF Attachment Table 2.SLMCPR Calculation Methodologies Previous Cycle Previous Cycle Rated Current Cycle Current Cycle Rated Description Minimum Core Flow Core Flow Limiting Minimum Core Flow Core Flow Limiting Limiting Case Case Limiting Case Case Non-power Distribution NEDC-3 260 I P-A NEDC-32601P-A Uncertainty Power Distribution NEDC-32601 P-A NEDC-3260 I P-A Methodology Power Distribution NEDC-32694P-A NEDC-32694P-A Uncertainty Core Monitoring System 3DMonicore 3DMonicore Table 2.SLMCPR Calculation Methodologies Verified Information Page 18 of25 GNF NON-PROPRIFfARY INFORMA nON Class I GNF Attachment Table 3.Monte Carlo Calculated SLMCPR vs.Estimate Previous Cycle Previous Cycle Rated Current Cycle Current Cycle Rated Description Minimum Core Flow Core Flow Limiting Minimum Core Flow Core Flow Limiting Limiting Case Case Limiting Case Case[[Table 3.Monte Carlo Calculated SLMCPR VS.Estimate Verified lnfonnation Page 19 of25 GNF NON-PROPRIETARY INFORMATION Class I GNF Attachment Table 3.Monte Carlo Calculated SLMCPR vs.Estimate Previous Cycle Previous Cycle Rated Current Cycle Current Cycle Rated Description Minimum Core Flow Core Flow Limiting Minimum Core Flow Core Flow Limiting Limiting Case Case Limiting Case Case II Table 3.Monte Carlo Calculated SLMCPR VS.Estimate Verified Information Page 20 of 25 GNF NON-PROPRIET AR Y INFORMATION Class I GNF Attachment Table 4.Non-Power Distribution Uncertainties Nominal (NRC-Previous Cycle Previous Cycle Current Cycle Current Cycle Approved)Value Minim um Core Rated Core Flow Minimum Core Rated Core Flow+/-(J (%)Flow Limiting Case Limiting Case Flow Limiting Case Limiting Case GETAB Feedwater Flow 1.76 N/A N/A N/A N/A Measurement Feedwater Temperature 0.76 N/A N/A N/A N/A Measurement Reactor Pressure 0.50 N/A N/A N/A N/A Measurement Core Inlet Temperature 0.20 N/A N/A N/A N/A Measurement Total Core Flow 6.0 SLO/2.5 TLO N/A N/A N/A N/A Measurement Channel Flow Area 3.0 N/A N/A N/A N/A Variation Friction Factor 10.0 N/A N/A N/A N/A Multiplier Channel Friction 5.0 N/A N/A N/A N/A Factor Multiplier Table 4.Non-Power Distribution Uncertainties Verified lnfonnation Page 21 of25 GNFNON-PROPRIETARY INFORMATION Class I GNF Attachment Table 4.Non-Power Distribution Uncertainties Nominal (NRC-Previous Cycle Previous Cycle Current Cycle Current Cycle Approved)Value Minim urn Core Rated Core Flow Minimum Core Rated Core Flow+/-(J (%)Flow Limiting Case Limiting Case Flow Limiting Case Limiting Case NEDC-32601 P-A Feedwater Flow[[]][[]][[]][[]][[]]Measurement Feedwater Temperature [[]][[]][[]][[]][[]]Measurement Reactor Pressure[[]][[]][[]][[]][[]]Measurement Core Inlet Temperature 0.2 0.2 0.2 0.2 0.2 Measurement Total Core Flow 6.0 SL0I2.5 TLO 6.0 SL0I3.02 TLO 6.0 SL0/2.5 TLO 6.0 SLO/3.02 TLO 6.0 SLO/2.5 TLO Measurement Channel Flow Area[[]][[]][[]][[]][[]]Variation Friction Factor[[]][[]][[]][[]][[]]Multiplier Channel Friction 5.0 5.0 5.0 5.0 5.0 Factor Multiplier Table 4.Non-Power Distribution Uncertainties Verifi.ed Infonnation Page 22 of25 GNF NON-PROPRIETARY INFORMATION Class 1 GNF Attachment Table 5.Power Distribution Uncertainties Nominal (NRC-Previous Cycle Previous Cycle Current Cycle Current Cycle Description Approved)Value Minimum Core Rated Core Flow Minimum Core Rated Core Flow+/-CJ (%)Flow Limiting Case Limiting Case Flow Limiting Case Limiting Case GETAB/NEDC-32601P-A GEXL R-Factor[[]]N/A N/A N/A N/A Random Effecti ve 2.85 SLO/l.2 TLO N/A N/A N/A N/A TIP Reading Systematic Effective 8.6 N/A N/A N/A N/A TIP Reading NEDC-32694P-A, 3DMONICORE GEXL R-Factor[[]][[]][[]][[]][[]]Random Effective 2.85 SLO/1.2 TLO 2.85 SL0I1.45 TLO 2.85 SLO/1.2 TLO 2.85 SLO/l.45 TLO 2.85 SLO/I.2 TLO TIP Reading TIP Integral[[n[[]J[[]][[)][[J)Four Bundle Power Distribution [[]][[]][[]][[]][[]]Surrounding TIP Location Contribution to Bundle Power[[]][[]][[]][[]][[]]Uncertainty Due to LPRM Update Table 5.Power Distribution Uncertainties Verified Infonnation Page 23 of25 GNF NON-PROPRIETARY INFORMATION Class I GNF Attachment Table 5.Power Distribution Uncertainties Nominal (NRC-Previous Cycle Previous Cycle Current Cycle Current Cycle Description Approved)Value Minim urn Core Rated Core Flow Minimum Core Rated Core Flow+/-G(%)Flow Limiting Case Limiting Case Flow Limiting Case Limiting Case Contribution to Bundle Power Due to[[]][[]][[]][[]][[]]Failed TlP Contribution to Bundle Power Due to[[]][[]][[]][[]][[]]Failed LPRM Total Uncertainty in Calculated Bundle[[]][[]][[]][[]][[]]Power Uncertainty of TIP Signal Nodal[[]][[]][[]][[]][[]]Uncertainty Table 5.Power Distribution Uncertainties Verified Information Page 2401'25 GNFNON-PROPRIETARY INFORMATION Class I GNF Attachment Table 6.Critical Power Uncertainties Nominal Value Previous Cycle Previous Cycle Current Cycle Current Cycle Description +/-CJ (%)Minimum Core Rated Core Flow Minimum Core Rated Core Flow Flow Limiting Case Limiting Case Flow Limiting Case Limiting Case[[]]Table 6.Critical Power Uncertainties Verified lnfonnation Page 25 of25 ATTACHMENT 6 Power/Flow Map for Cycles 18 and 19 Core Flow (Mlb/hr)0 10 20 30 40 SO 60 70 80 90 100 110 120 120 4000 110 A: Natar.l Circulation B: 30" Kinuu,_Pt.UIlp Speed 113.2%Rod LiDe 0 E F C: 61.Pov.rl J8.0'.rlow 3600 100 D: 100.0'Powerl B2.8*.Fle..D': 98.5-Poverl 81.0", Flow.W_)dI_.I: 100.0..Powerl 100.O'Flow F E': Pawer/ Flow 3200 90 F: 100.Pawerl 110.0", Flow P': 98.S:" P""../110.0'Plaw G: 19.'ovet"1 !'low 2800 80 Y: 19.7*Poverl IOO.O'!Flow.-.91.41%TPO....LiDo-I: 19.1, Powerl 37.Flow.-.ICP: Incr****d Cor.flow-70 2400----....U U602000 0 l:l.l:l...fCF'i E SO E..8 1600..u U.t: Approx.30'%Pump SpHd.t:!-40 A u-Limlt Lile!-.---1200 30 Approx.N8tInl Circuldon 800 20 9-----..-----.'...-0 Cavie.tioa IDlcrtock H G.'400 10/IOO"!TPO* HWt 100', CLTP*3458 M1tt ,.100, Core Flow*t02.S Hlb/hr.....'0 0 0 10 20 30 40 SO 60 70 80 90 100 110 120 Core Flow (-1_)}}