ML13329A037

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Palo Verde Nuclear Generating Station - Application for Technical Specification Change Regarding Moderator Temperature Coefficient (Mtc) Surveillance for Startup Testactivity Reduction Program Using the Consolidated Line Item Improvement Pr
ML13329A037
Person / Time
Site: Palo Verde  
Issue date: 11/20/2013
From: Mims D C
Arizona Public Service Co
To:
Document Control Desk, Office of Nuclear Reactor Regulation
References
102-06784-DCM/RKR
Download: ML13329A037 (31)
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Text

10 CFR 50.90DWIGHT C. MIMSQ aps Senior Vice President, NuclearRegulatory

& Oversight Palo VerdeNuclear Generating StationP.O. Box 52034Phoenix, AZ 85072Mail Station 7605102-06784-DCM/RKR Tel 623 393 5403November 20, 2013ATTN: Document Control DeskU.S. Nuclear Regulatory Commission 11555 Rockville PikeRockville, Maryland 20852

Dear Sirs:

Reference:

APS to NRC letter number 102-06785, Palo Verde Nuclear Generating

Station, Units 1, 2, and 3, Docket Nos. STN 50-528/529/530, Transmittal ofProprietary Documents for Startup Test Activity Reduction (STAR) ProgramLicense Amendment Request (LAR), dated November 20, 2013

Subject:

Palo Verde Nuclear Generating StationUnits 1, 2, and 3Docket Nos. STN 50-528/529/530 Application for Technical Specification Change Regarding Moderator Temperature Coefficient (MTC) Surveillance forStartup TestActivity Reduction (STAR) Program Using theConsolidated Line Item Improvement Process (CLIIP)In accordance with the provisions of 10 CFR 50.90 Arizona Public Service Company(APS) is submitting a request for an amendment to the technical specifications (TS)for Palo Verde Nuclear Generating Station (PVNGS) Units 1, 2, and 3. The proposedamendment would modify moderator temperature coefficient (MTC) TS surveillance requirements (SR) associated with implementation of WCAP-16011-P-A, StartupTest Activity Reduction (STAR) Program.

The availability of this TS improvement wasannounced in the Federal Register (FR) on September 6, 2007 (72 FR 51259), as partof the Consolidated Line Item Improvement Process (CLIIP).

In addition, relatedTSTF-406, Revision 2, Predicting End-Of-Cycle MTC and Deleting Need for End-Of-Cycle MTC Verification (CE-NPSD-911-A),

is also included in this submittal.

Attachment 1 provides a description of the proposed change, the requested confirmation of applicability and plant-specific verifications.

Attachment 2 providesthe existing TS pages marked up to show the proposed change. Attachment 3provides revised (clean) TS pages. Attachment 4 provides a summary of theregulatory commitments made in this submittal.

Attachment 5 provides theA member of the STARS (Strategic Teaming and Resource Sharing)

AllianceCallaway 0 Comanche Peak 0 Diablo Canyon

  • Palo Verde 0 San Onofre 0 South Texas
  • Wolf .Creek ATTN: Document Control Desk 4U.S. Nuclear Regulatory Commission Application for Technical Specification Change Regarding Moderator Temperature Coefficient (MTC) Surveillance for Startup Test Activity Reduction (STAR) ProgramUsing the Consolidated Line Item Improvement Process (CLIIP)Page 2proposed changes to Technical Specification Bases pages.The changes are consistent with NRC approved Industry Technical Specification Task Force (TSTF) Standard Technical Specification Change Traveler, TSTF-486, Revision 2, Revise MTC Surveillance for Startup Test Activity Reduction (STAR)Program (WCAP-16011).

The non-proprietary version of WCAP-16011, Startup TestReduction Activity Program is available to the NRC staff [Agencywide Documents Access and Management System (ADAMS) Accession number ML050660118].

APSdid not initially participate in the industry effort that developed WCAP-16011.

APShas subsequently become a participant and specific evaluations have beenperformed to support implementation of TSTF-486 for PVNGS. The evaluations included relevant industry operating experience since NRC approval of TSTF-486.

The non-proprietary version of the evaluation document (WCAP-17787, Palo VerdeNuclear Generating Station STAR Program Implementation Report) is provided asAttachment 6 to this submittal.

The proprietary versions of WCAP-16011 andWCAP-17787 were provided by the reference letter.Related TSTF-406, Revision 2, Predicting End-Of-Cycle MTC and Deleting Need forEnd-Of-Cycle MTC Verification (CE-NPSD-911-A),

is included in this submittal.

Thesupporting document for TSTF-406, CE-NPSD-911--A and Amendment 1-A, Analysisof Moderator Temperature Coefficients in Support of a Change in the Technical Specification End of Cycle Negative MTC Limit, September 15, 2000, is available tothe NRC staff (ADAMS Accession number ML003752592).

Attachment 7 is Near Endof Cycle (EOC) MTC Elimination Informational Benchmark, that documents thatcomputer codes CASMO/SIMULATE and DIT/ROCS provide similar results.

Thisattachment, in conjunction with Appendix D of WCAP-17787, supports theapplication of CE-NPSD-911-A and Amendment 1-A for PVNGS.APS requests approval of the proposed license amendment within one year of thedate of this letter. APS requests an implementation period of 90-days afterissuance of the license amendment.

A pre-submittal public meeting was held, regarding this submittal, between APSand the NRC staff on July 11, 2013, and is summarized in NRC letter dated August5, 2013 (ADAMS Accession number ML13197A095).

In accordance with the PVNGS Quality Assurance

Program, the Plant Review Boardand the Offsite Safety Review Committee have reviewed and concurred with theamendment proposed herein. By copy of this letter, this submittal is beingforwarded to the Arizona Radiation Regulatory Agency (ARRA) pursuant to 10 CFR50.91(b)(1).

ATTN: Document Control DeskU.S. Nuclear Regulatory Commission Application for Technical Specification Change Regarding Moderator Temperature Coefficient (MTC) Surveillance for Startup Test Activity Reduction (STAR) ProgramUsing the Consolidated Line Item Improvement Process (CLIIP)Page 3Should you need further information regarding this amendment

request, pleasecontact Robert K. Roehler, Licensing Section Leader, at (623) 393-5241.

I declare under penalty of perjury that the foregoing is true and correct.Executed on bbc1"dbf',?,9o/3 (Date)Sincerely, Fea74 2). Z-.$~DCM/RKR/CJS/hsc Attachments:

1. Description and Assessment
2. Proposed Technical Specification Changes3. Revised Technical Specification Pages4. Regulatory Commitments
5. Proposed Technical Specification Bases Changes6. WCAP-17787, Palo Verde Nuclear Generating Station STAR ProgramImplementation Report (Non-Proprietary Version)7. Near End of Cycle (EOC) MTC Elimination Informational Benchmark, August13, 2013cc: M. L. Dapas NRC Region IV Regional Administrator J. K. Rankin NRC NRR Project ManagerM. A. Brown NRC Senior Resident Inspector for PVNGSA. V. Godwin Arizona Radiation Regulatory Agency (ARRA)T. Morales Arizona Radiation Regulatory Agency (ARRA)

ATTACHMENT 1DESCRIPTION AND ASSESSMENT Attachment ILicense Amendment Request forAdoption of TSTF-486 and TSTF-4061.0 DESCRIPTION The proposed amendment would modify moderator temperature coefficient (MTC)technical specification (TS) surveillance requirements (SR) associated withimplementation of WCAP-16011-P-A, Startup Test Activity Reduction (STAR)Program (WCAP-16011).

The changes are consistent with Nuclear Regulatory Commission (NRC) approved Industry/Technical Specification Task Force (TSTF)Standard Technical Specification change TSTF-486, Revision

2. The Federal Registernotice published on September 6, 2007, announced the availability of this TSimprovement through the consolidated line item improvement process (CLIIP).The changes are consistent with NRC approved TSTF-486, Revision
2. The non-proprietary version of WCAP-16011, Startup Test Reduction Activity Program isavailable to the NRC staff [Agencywide Documents Access and Management System(ADAMS) Accession number ML050660118]

(Reference 1). Arizona Public ServiceCompany (APS) did not initially participate in the industry effort that developed WCAP-16011.

APS has subsequently become a participant and specific evaluations have been performed to support implementation of TSTF-486 for the Palo VerdeNuclear Generating Station (PVNGS).

The evaluations included relevant industryoperating experience since NRC approval of TSTF-486.

The non-proprietary versionof the evaluation document (WCAP-17787, Palo Verde Nuclear Generating StationSTAR Program Implementation Report) is provided as Attachment 6 of thissubmittal.

The proprietary versions of the relevant WCAPs were provided byseparate correspondence.

In addition, TSTF-406, Revision 2, Predicting End-Of-Cycle MTC and Deleting Needfor End-Of-Cycle MTC Verification (NPSD-911-A),

is appropriately reflected in thissubmittal.

The supporting document for TSTF-406, CE-NPSD-911-A andAmendment 1-A, Analysis of Moderator Temperature Coefficients in Support of aChange in the Technical Specification End of Cycle Negative MTC Limit, September 15, 2000, is available to the NRC staff (ADAMS Accession number ML003752592) and, therefore, is not included in this submittal (Reference 2). Attachment 7 isNear End of Cycle (EOC) MTC Elimination Informational Benchmark, that documents that computer codes CASMO/SIMULATE and DIT/ROCS provide similar results.

Thisattachment, in conjunction with Appendix D of WCAP-17787, supports theapplication of CE-NPSD-911-A for PVNGS.2.0 ASSESSMENT 2.1 Applicability of Published Safety Evaluation APS has reviewed the safety evaluation dated August 29, 2007, as part of theCLIIP. This review included a review of the NRC staff's evaluation, as well as thesupporting information provided to support TSTF-486, Revision

2. APS hasconcluded that the justifications presented in the TSTF proposal and the safety1 Attachment 1License Amendment Request forAdoption of TSTF-486 and TSTF-406evaluation prepared by the NRC staff are applicable to PVNGS Units 1, 2 and 3 andjustify this amendment for the incorporation of the changes to the PVNGS TS forthose elements of this license amendment request (LAR) that are derived fromTSTF-486.

Related TSTF-406 is also appropriately included in this LAR. The Regulatory Analysis section of this LAR addresses the no significant hazards consideration determination (NSHCD) for both TSTF-486 and TSTF-406.

3.2 Optional Changes and Variations APS is not proposing variations or deviations from the TS changes described in themodified TSTF-486, Revision 2, and the NRC staff's model safety evaluation datedAugust 29, 2007. The only differences are from the Standard Technical Specification (NUREG-1432) regarding the limiting condition for operation (LCO)number and an existing note in SR 3.1.4.2, which remain consistent with thePVNGS TS.The changes to TS that implement CE-NPSD-911 are consistent with the changesmodeled in the NRC approved CE-NPSD-911 and other industry precedents.

Theproposed change, therefore, differs from the specific text proposed in TSTF-406.

Specifically, a new Note 3 is added to surveillance requirement (SR) 3.1.4.2 thatreads as follows:"The MTC verification at 2/3 of expected core burnup is not required if theresults of the measurement at 40 EFPD are within a tolerance of+/- 0.16*10E4Ak/k/°F from the corresponding design values."The proposed Note is more technically consistent with the underlying analysis thanthe TSTF-406 Note text that refers to a tolerance band of +/-0.16*10E 4Ap/OF of therespective limits in the COLR. In addition, the use of the units Ak/k/°F, ascompared to Ap/°F used in TSTF-406, is consistent with the units used in the LCO.The revised TS pages were formatted, with appropriate page breaks, to facilitate operator use.3.0 REGULATORY ANALYSIS3.1 No Significant Hazards Consideration Determination Arizona Public Service Company (APS) has reviewed the proposed no significant hazards consideration determination (NSHCD) published in the Federal Register aspart of the consolidated line item improvement process (CLIIP).

APS has concluded that the proposed NSHCD presented in the Federal Register notice is applicable tothe Palo Verde Nuclear Generating Station (PVNGS),

Units 1, 2 and 3 and is herebyincorporated by reference to satisfy the requirements of 10 CFR 50.91(a) for theTSTF-486 proposed changes.

In addition, the following NSHCD is provided toreflect the TSTF-406.

2 Attachment 1License Amendment Request forAdoption of TSTF-486 and TSTF-406APS has determined that the proposed TS amendment changes related to TSTF-406do not involve a significant hazards consideration under the standards set forth in10 CFR 50.92(c).

This determination is based on evaluation with respect to thespecific criteria of 10 CFR 50.92(c) as follows:1. Does the proposed amendment involve a significant increase in theprobability or consequences of an accident previously evaluated?

Response:

No.A change is proposed to eliminate the measurement of end-of-cycle (EOC)moderator temperature coefficient (MTC) if the beginning-of-cycle (BOC)measurements are within a given tolerance to the predicted value. MTC is notan initiator of any accident previously evaluated.

Consequently, theprobability of an accident previously evaluated is not significantly increased.

The EOC MTC value is an important assumption in determining theconsequences of accidents previously evaluated.

The analysis presented inthe Topical Report determined that the EOC MTC will be within limits if theBOC measured MTC values are within a given tolerance of the measuredvalues. Therefore, the EOC MTC will continue to be within limits and theconsequences of accidents will continue to be as previously evaluated.

Therefore, the consequences of an accident previously evaluated are notsignificantly increased by this change.Based on the above, the proposed amendment does 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.A change is proposed to eliminate the measurement of EOC MTC if the BOCmeasurements are within a given tolerance to the predicted value. Theproposed change does not involve a physical alteration of the plant (no newor different type of equipment will be installed) or a change in the methodsgoverning normal plant operation.

Based on the above, the proposed amendment does not create the possibility of a new or different kind of accident from any accident previously evaluated.

3 Attachment 1License Amendment Request forAdoption of TSTF-486 and TSTF-4063. Does the proposed amendment involve a significant reduction in a margin ofsafety?Response:

No.A change is proposed to eliminate the measurement of EOC MTC if the BOCmeasurements are within a given tolerance to the predicted value. TheTopical Report concluded that the risk of not measuring the EOC MTC isacceptably small provided that the BOC measured values are within a specifictolerance of the predicted values.Therefore, the proposed amendment does not involve a significant reduction in a margin of safety.Based on the above, APS concludes that the proposed amendment does not involvea significant hazards consideration under the standards set forth in 10 CFR50.92(c),

and accordingly, a finding of "no significant hazards consideration" isjustified.

3.2 Verification and Commitments As discussed in the notice of availability published in the Federal Register onSeptember 6, 2007, for this TS improvement, APS verifies the applicability of TSTF-486 to PVNGS Units 1, 2 and 3, and commits to establishing Technical Specification Bases for TS 3.1.4 as proposed in TSTF-486, Revision 2, and documented inAttachment 4 of this submittal.

APS also will implement the conditions andlimitations of the NRC staff safety evaluation for WCAP-16011.

The proposed TSTF-486 change revises SR 3.1.3.1 in the digital Combustion Engineering standard technical specifications (NUREG-1432)

(i.e., PVNGS 3.1.4.1)by adding a second frequency.

This second frequency requires verifying that MTC iswithin the upper limit each fuel cycle within 7 EFPD after reaching 40 EFPD of coreburnup, but only when the MTC determined prior to entering MODE 1 is verifiedusing predicted MTC as adjusted for actual RCS boron concentration.

The Frequency is consistent with the existing MODE 1 MTC surveillance frequency.

The TS Bases are revised to describe the new requirements and to clarify theanalytical basis of the MTC utilizing the suggested changes in WCAP-16011-P-A.

The Bases modifications clarify the relationship between the MTC limits specified inthe Core Operating Limits Report (COLR) and the maximum positive MTC valuespecified in the LCO. The UFSAR will be revised, pursuant to 10 CFR 50.71(e),

toupdate the description of the performance of rod worth or symmetry testingfollowing each refueling outage. The UFSAR.update will reflect the elimination of rodworth or symmetry testing when the applicability requirements of WCAP-17787 aremet.4 Attachment 1License Amendment Request forAdoption of TSTF-486 and TSTF-4064.0 ENVIRONMENTAL EVALUATION APS has reviewed the environmental evaluation included in the model safetyevaluation dated August 29, 2007, as part of the CLIIP. APS has concluded that thestaff's findings presented in that evaluation are applicable to PVNGS Units 1, 2, and3, and the evaluation is hereby incorporated by reference for this application.

5.0 REFERENCES

1. WCAP- 16011- N P-A, Startup Test Activity Reduction (STAR) Program,Revision 0, dated February 2005 (ADAMS Accession number ML050660118)
2. CE-NPSD-911-A and Amendment 1-A, Analysis of Moderator Temperature Coefficients in Support of a Change in the Technical Specification End ofCycle Negative MTC Limit, dated September 15, 2000 (ADAMS Accession number ML003752592) 5 ATTACHMENT 2PROPOSED TECHNICAL SPECIFICATION CHANGESProposed Technical Specification ChangesTS Pages(Markup Pages)3.1.4-13.1.4-23.1.4-3 MTC3.1.43.1 REACTIVITY CONTROL SYSTEMS3.1.4 Moderator Temperature Coefficient (MTC)LCO 3.1.4APPLICABILITY:

The MTC shall be maintained within the limits specified inthe COLR, and a maximum positive limit that varies linearlyfrom 0.5 E-4 Ak/k/°F at 0% RTP to 0.0 Ak/k/0F at 100% RTP.MODES 1 and 2.ACTIONSCONDITION REQUIRED ACTION COMPLETION TIMEA. MTC not within limits. A.1 Be in MODE 3. 6 hour6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />sSURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.1.4.1 -----------------

NOTE----------------

This Surveillance is not required to beperformed prior to entry into MODE 2.Verify MTC is within the upper limit Prior tospecified in the COLR. entering MODE 1after each fuelloading(continued)

PALO VERDE UNITS 1,2,33.1.4-1AMENDMENT NO. 117 MTC3.1.4SURVEILLANCE REQUIREMENTS (continued)

SURVEILLANCE FREQUENCY ANDSR 3.1.4.1 (continued)

NOTE -----Only requiredto be performed when MTCdetermi nedpr or toentering MODE 1is verifiedusing adjustedpredicted MTCEach fuel cyclewithi-n7 EFPDof reaching 40EFPD coreburnupSR 3.1.4.2 ----------------

NOTES--------------

1. This Surveillance is not required tobe performed prior to entry intoMODE 1 or 2.2. If the MTC is more negative than theGQLR-limit specified in the COLR whenextrapolated to the end of cycle,SR 3.1.4.2 may be repeated.

Shutdownmust occur prior to exceeding theminimum allowable boron concentration at which MTC is projected to exceedthe lower limit.3. The MTC verification at 2/3 ofexpected core burnup is not requiredif the results of the measuremen at40 EFPD are within a toler~afnceo

+/- 0.16*10E-4 Ak/k/°F from thecorresponding design values.PALO VERDE UNITS 1,2,33.1.4-2AMENDMENT NO. -ýý MTC3.1.4SURVEILLANCE REQUIREMENTS (continued)

SURVEILLANCE FREQUENCY SR 3.1.4.2 (continued)

Verify MTC is within the lower limitspecified in the COLR.Each fuel cyclewithin7 effcctive full po'.e'cdays EFPD ofreaching40 EFPD coreburnupANDEach fuel cyclewithin 7 EFPDof reaching 2/3 of expectedcore burnupPALO VERDE UNITS 1,2,33.1.4-3AMENDMENT NO. 444 ATTACHMENT 3REVISED TECHNICAL SPECIFKCATION PAGESTS Pages(Clean Pages)3.1.4-13.1.4-23.1.4-3 MTC3.1.43A1 REACTIVITY CONTROL SYSTEMS3,1.4 Moderator Temperature Coefficient (MTC)LCO 3.1.4APPLICABILITY:

The MTC shall be maintained within the limits specified inthe COLR, and a maximum positive limit that varies linearlyfrom 0.5 E-4 Ak/k/°F at 0% RTP to 0.0 Ak/k/°F at 100% RTP.MODES 1 and 2.ACTIONSCONDITION REQUIRED ACTION COMPLETION TIMEA. MTC not within limits. A.1 Be in MODE 3. 6 hour6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />sPALO VERDE UNITS 1,2,33.1.4-1AMENDMENT NO.

MTC3.1.4SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.1.4.1---- NOTE---------------

This Surveillance is not required to beperformed prior to entry into MODE 2.Verify MTC is within the upper limitspecified in the COLR.Prior toentering MODE 1after each fuelloadingAND------ NOTE -----Only requiredto be performed when MTCdetermined prior toentering MODE 1is verifiedusing adjustedpredicted MTCEach fuel cyclewithin 7 EFPD ofreaching 40 EFPDcore burnup(continued)

PALO VERDE UNITS 1,2,33.1.4-2AMENDMENT NO. 44ý MTC3.1.4SURVEILLANCE REQUIREMENTS (continued)

SURVEILLANCE FREQUENCY SR 3.1.4.2 ----------------

NOTES--------------------

1. This Surveillance is not required tobe performed prior to entry intoMODE 1 or 2.2. If the MTC is more negative than thelimit specified in the COLR whenextrapolated to the end of cycle,SR 3.1.4.2 may be repeated.

Shutdownmust occur prior to exceeding theminimum allowable boron concentration at which MTC is projected to exceedthe lower limit.3. The MTC verification at 2/3 ofexpected core burnup is not requiredif the results of the measurement at40 EFPD are within a tolerance of+/- 0.16*10E-4 Ak/k/0F from thecorresponding design values.Verify MTC is within the lower limit Each fuel cyclespecified in the COLR. within 7 EFPDof reaching40 EFPD coreburnupANDEach fuel cyclewithin 7 EFPDof reaching 2/3of expectedcore burnupL ___________________________________________________________

PALO VERDE UNITS 1,2,33.1.4-3AMENDMENT NO. 44--ý ATTACHMENT 4REGULATORY COMMITMENTS The following table identifies those actions committed to by Arizona Public ServiceCompany (APS) in this document for the Palo Verde Nuclear Generating Station(PVNGS).

Any other statements in this submittal are provided for information purposes and are not considered to be regulatory commitments.

Please directquestions regarding these commitments to Robert K. Roehler, Licensing SectionLeader, at (623) 393-5241.

REGULATORY COMMITMENTS DUE DATE/EVENT APS will establish Technical Specification Complete and implement with approvedBases for TS 3.1.4 consistent with those license amendment implementation.

shown in the license amendment.

APS will include verification of the Complete and implement with approvedapplicability requirements in appropriate site license amendment implementation.

startup testing procedures.

APS will includeguidance in the procedures to ensure thatthe safety analysis and STAR applicability requirements are satisfied when STAR testresults fall outside the test criteria.

If thesafety analysis or STAR applicability requirements are not satisfied, the STARprogram for the affected fuel cycle will notbe used.APS will submit a summary report following Within 90-days of completion of the firstthe first application of STAR at PVNGS that application of STAR at PVNGS.will: (a) identify the core design methodused, (b) compare the measured andcalculated values and the differences between these values to the corresponding core design method uncertainties and (c)show compliance with the STAR applicability requirements.

If the application of STAR isunsuccessful, APS will identify the reasonswhy the STAR application failed.

ATTACHMENT 5PROPOSED TECHNICAL SPECIFICATION BASES PAGES CHANGESTS Bases Pages(Markup Pages)B 3.1.4-1B 3.1.4-2B 3.1.4-3B 3.1.4-4B 3.1.4-5B 3.1.4-6 MTCB 3.1.4B 3.1 REACTIVITY CONTROL SYSTEMSB 3.1.4 Moderator Temperature Coefficient (MTC)BASESBACKGROUND According to GDC 11 (Ref. 1), the reactor core and itsinteraction with the Reactor Coolant System (RCS) must bedesigned for inherently stable power operation, even in thepossible event of an accident.

In particular, the netreactivity feedback in the system must compensate for anyunintended reactivity increases.

The MTC relates a change in core reactivity to a change inreactor coolant temperature.

A positive MTC means thatreactivity increases with increasing moderator temperature:

conversely, a negative MTC means that reactivity decreases with increasing moderator temperature.

The reactor isdesigned to operate with a negative MTC over the largestpossible range of fuel cycle operation.

Therefore, acoolant temperature increase will cause a reactivity

decrease, so that the coolant temperature tends to returntoward its initial value. Reactivity increases that cause acoolant temperature increase will thus be self limiting, andstable power operation will result. The same characteris i4 true when thc MIC is positive andcolant temper-aturce MTC values are predicted at selected burnups andtemperatures during the safety evaluation analysis and areconfirmed to be acceptable by measurements.

Both initialand reload cores are designed so that the beginning of cycle(BOC) MTC is less positive than that allowed by the LCO.The actual value of the MTC is dependent on corecharacteristics such as fuel loading and reactor coolantsoluble boron concentration.

The core design may requireadditional burnable absorbers, either fixed lumped poisonrods or poisons distributed within selected fuel rods toyield an MTC at the BOC within the range analyzed in theplant accident analysis.

The end of cycle (EOC) MTC is alsolimited by the requirements of the accident analysis.

Fuelcycles that are designed to achieve high burnups or thathave changes to other characteristics are evaluated toensure that the MTC does not exceed the EOC limit.(continued)

PALO VERDE UNITS 1,2,3B 3. 1.4-1REVISION 4

MTCB 3.1.4BASES (continued)

APPLICABLE The acceptance criteria for the specified MTC are:SAFETY ANALYSESa. The MTC values must remain within the bounds of thoseused in the accident analysis (Ref. 2);.andb. The MTC must be such that inherently stable poweroperations result during normal operation and duringaccidents, such as overheating and overcooling events.Reference 2 contains analyses of accidents that result inboth overheating and overcooling of the reactor core. MTCis one of the controlling parameters for core reactivity inthese accidents.

Both the most" positive value and mostnegative value of the MTC are important to safety, and bothvalues must be bounded.

Values used in the analysesconsider worst case conditions, such as very large solubleboron concentrations, to ensure the accident results arebounding.

Accidents that cause core overheating, either by decreased heat removal or increased power production, must beevaluated for results when the MTC is positive.

Reactivity accidents that cause increased power production include thecontrol element assembly (CEA) withdrawal transient fromeither subcritical or full THERMAL POWER. The limitingoverheating event relative to plant response is based on theLoss of Condenser Vacuum event (Ref. 3). The most limitingevent with respect to a positive MTC is a CEA withdrawal accident from a subcritical or low (hot zero) powercondition, also referred to as a startup accident (Ref. 4).Accidents that cause core overcooling must be evaluated forresults when the MTC is most negative.

The event thatproduces the most rapid cooldown of the RCS, and istherefore the most limiting event with respect to thenegative MTC, is a steam line break (SLB) event. Following the reactor trip for the postulated EOC SLB event, the largemoderator temperature reduction combined with the largenegative MTC may produce reactivity increases that are asmuch as the shutdown reactivity.

When this occurs, asubstantial fraction of core power is produced with all CEAsinserted, except the most reactive one, which is assumedwithdrawn.

Even if the reactivity increase producesslightly subcritical conditions, a large fraction of corepower may be produced through the effects of subcritical neutron multiplication.

(continued)

PALO VERDE UNITS 1,2,3B 3.1.4-2REVISION 31 MTCB 3.1.4BASES (continued)

APPLICABLE MTC values are bounded in reload safety evaluations assumingSAFETY ANALYSES steady state conditions at BOC and EOC. A middle of cycle(continued)

(MOC) measurement is conducted at conditions when the RCSboron concentration reaches approximately 300 ppm. Themeasured value may be extrapolated to project the EOC value,in order to confirm reload design predictions.

The MTC satisfies Criterion 2 of 10 CFR 50.36 (c)(2)(ii).

LCO LCO 3.1.4 requires the MTC to be within the positive andnegative limits specified in limits of the COLR to ensurethe core operates within tFehassumptions of the accidentanalysis.

During the reload core safety evaluation, the MTCis analyzed to determine that its values remain within thebounds of the original accident analysis during operation.

The positive MTC limit in the COLR The limit on a positiveM-6-ensures that core overheating accidents will not violatethe accident analysis assumptions.

The negative MTC limitfor EOC specified in the COLR ensures that core overcooling accidents will not violate the accident analysisassumptions.

The MTC limit specified in the LCO is the maximum positiveMTG value approved in the plant's licensing basis andensures that the reactor operates with a negative MT7 overthe largest possible range fuel cycle operation.

The cycle-specific MTC limit specified in the COLR must be equal to orless positive than the MTC limit specified in the LCO.MTC is a core physics parameter determined by the fuel andfuel cycle design and cannot be easily controlled once thecore design is fixed. Limited control of MTC can be achievedby adjusting CEA position and boron concentration.

Duringoperation, thereeforp~e,-the LTO can 4-l-y-be ensured throughmeasurement and adjustments to CEA position and boronconcentration.

The surveillance checks at BOG and MOC on anMTC provide confirmation that the MTC is behaving asanticipated, so that the acceptance criteria are met.APPLICABILITY In MODE 1, the limits on the MTC must be maintained toensure that any accident initiated from THERMAL POWERoperation will not violate the design assumptions of theaccident analysis.

In MODE 2. the limits must also bemaintained to ensure accidents, such as the uncontrolled CEA(continued)

PALO VERDE UNITS 1.2,3B 3.1.4-3REVISION MTCB 3.1.4BASES (continued)

APPLICABILITY assembly or group withdrawal, will not violate the(continued) assumptions of the accident analysis.

In MODES 3, 4, 5,and 6, this LCO is not applicable, since no Design BasisAccidents (DBAs) using the MTC as an analysis assumption areinitiated from these MODES except for a MSLB in MODE 3. Inthis case, the analysis assumes worst case MTC, with theECCS systems mitigating the event.However, the variation of the MTC, with temperature in MODES3, 4, and 5, for DBAs initiated in MODES 1 and 2, isaccounted for in the subject accident analysis.

Thevariation of the MTC, with temperature assumed in the safetyanalysis, is accepted.

as valid once the BOC and MOCmeasurements are used for normalization.

ACTIONS A.1MTC is a function of the fuel and fuel cycle designs.

andcannot.be controlled directly once the designs have beenimplemented in the core. If MTC exceeds its limits, thereactor must be placed in MODE 3. This eliminates thepotential for violation of the accident analysis bounds.The associated Completion Time of 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> is reasonable, considering the probability of an accident occurring duringthe time period that would require an MTC value within theLCO limits, and the time for reaching MODE 3 from full powerconditions in an orderly manner and without challenging plant systems.SURVEILLANCE SR 3.1.4.1 and SR 3.1.4.2REQUIREMENTS The SRs for measurement of the MTC at the beginning andmiddle of each fuel cycle provide for confirmation of thelimiting MTC values. The MTC changes smoothly from mostpositive (least negative) to most negative value during fuelcycle operation, as the RCS boron concentration is reducedto compensate for fuel depletion.

For fuel cycles that meet the applicability requirements inReference 5, and specifically the acceptance criteria thatmust be met in order to substitute the measured value of MTCat hot zero power (HZP) with ar alternate MTC value, SR3.1.4.1 may be met prior to entering MODE 1 after each fuel(continued)

PALO VERDE UNITS 1.2,3B 3.1.4-4REVISION 4

MTCB 3.1.4BASES (continued)

SURVEILLANCE SR 3.1.4.1 and SR 3.1.4.2 (continued)

REQUIREMENTS loading by confirmation that the predicted MTC, whenadjusted for the measured RCS boron concentration, is withinthe most positive (least negative)

MTC limit specified inthe COLR. If this adjusted predicted MIC value is used tomeet the SR prior to enterinj MODE 1, a confirmation bymeasurement that MTC is within the upper MTC limit must beperformed in MODE 1 within 7 Effective Full Power Days(EFPD) of reaching 40 EFPD of core burnup. Theapplicability requirements in Reference 5 ensure coredesigns are not significantly different from those used tobenchmark predictions and require that the measured RCSboron concentration meets specific test criteria.

Thisprovides assurance that the MTC obtained from the adjustedpredicted MTC is accurate.

For fuel cycles that do not meet the applicability requirements in Reference 5, the verification of MICrequired prior to entering MODE 1 after each fuel loading isperformed by calculation of the MTC based on measurement ofthe isothermal temperature coefficient, In this case,measurement of MTC within 7 EFPD of reaching 40 EFPD of coreburnup is not required for SR 3.1.4.1.The requirement for measurement prior to operation

> 5% RTPsatisfies the confirmatory check on the most positive (leastnegative)

MTC value.The requirement for measurement, within 7 4ay-, EFPD of(before or after) reaching 40 EFPD effective fuTVT:-,poer daysand a 2/3 core burnup, confirmatory check ofthe most negative MTC value. The measurement is performed at any THERMAL POWER so that the projected EOC MTC may beevaluated before the reactor actually reaches the EOCcondition.

MTC values may be extrapolated and compensated to permit direct comparison to the ,pee4-fie MTC limitsspecified in the COLR.SR 3.1.4.2 is modified by a Note that indicates performance is not required prior to entering MODE 1 or 2. Althoughthis Surveillance is applicable in MODES 1 and 2, thereactor must be critical before the Surveillance can becompleted.

Therefore, entry into the applicable MODE priorto accomplishing the Surveillance is necessary.

(continued)

PALO VERDE UNITS 1,2.3B 3. 1.4-5REVISION

-9 MTCB 3.1.4BASES (continued)

SURVEILLANCE SR 3.1.4.1 and SR 3.1.4.2 (continued)

REQU IREMENTSSR 3.1.4.2 is modified by a second Note, which indicates that if extrapolated MTC is more negative than the EOClimit specified in the COLR. the Surveillance may berepeated.

and that shutdown must occur prior to exceeding the minimum allowable boron concentration at which MTC isprojected to exceed the lower limit. An engineering evaluation is performed if the extrapolated value of MTCexceeds the Specification limits. An extrapolation to theend of cycle is only required if the measurement at 2/3cycle is performed.

SR 3.1.4.2 is modified by a third Note, which indicates thatthe Surveillance, which determines MTC 2/3 expected coreburnup is only required if the MTC determined in SR 3.1.4.1and at 40 EFPD are not within 0.16*10E-4 Ak/k/°F of thecorresponding design values. For cycles that meet theapplicability requirements given in Reference 5, the MTCverification of MIC at 2/3 expected core burnup is notrequired if the result of the measurement at 40 EFPD iswithin a tolerance of 0.16"10E-4 Ak/k/°F of thecorresponding design value.REFERENCES

1. 10 CFR 50, Appendix A, GDC 11.2. UFSAR, Section 15.0.3. UFSAR, Section 15.2.4. UFSAR. Section 15.4.5. WCAP-17787, "Palo Verde [uclear Generating StationSTAR Program Implementation._
6. CE-NPSD-911, "Analysis of Moderator Temperature Coefficients in Support cf a Change in the Technical Specification End-of-Cycle MTC Limit", September 2000.PALO VERDE UNITS 1,2,3B 3.1.4-6REVISION 4

ATTACHMENT 7Near End of Cycle (EOC) MTC Elimination Informational Benchmark, August 13, 2013 I P s A subsidiary of Pinnacle West Capital Corporation Phillip S. Hoffspiegel Tel. 623-393-5144 Mail Station 7693Section Leader Fax 623-393-5797 PO Box 52034Nuclear Analysis e-mail phillip.hoffspiegel

@aps.com

Phoenix, Arizona 85072-2034 Nuclear Fuel AnalysisPalo Verde NuclearGenerating Station162-13763-PSH August 13, 2013

Dear Andrew Cecchetti:

Subject:

Near End of Cycle (EOC) Moderator Temperature Coefficient (MTC) Surveillance Elimination Informational Benchmark Enclosed is Palo Verde's two-thirds expected core burnup surveillance MTC elimination informational benchmark.

This informational benchmark used NRC approved CASMO/SIMULATE methodology.

The Attachment provides the benchmark that will need to be transmitted to the NRCprior to eliminating the need to measure the MTC upon reaching two-thirds of expected core burnup.If you have any further comments or questions please feel free to contact me at 623-393-5144 or viae-mail at phillip.hoffspiegel(ilaps.com.

bDigtallysigned byHoffspiegeI, Phillp S(Z05641)

Hoffspiegel, Phillip S(Z05 o.o6f~~iO3.O.316:27-33-)7'00' Phillip S. Hoffspiegel Section Leader, Nuclear Analysis

Attachment:

1) "Near End of Cycle (EOC) MTC Elimination Informational Benchmark" Distribution (with Attachment):

Brian S. Blackmore (7693)Brian J. Hansen (7693)Scott D. Leland (7693)William F. McDonald (7693)Robert P. Neville (7693)Kathleen R. Parrish (7693)Robert K. Roehler (7636)Daniel A. Smith (7693)Carl J. Stephenson (7636)John D. Wade (7693)Thomas N. Weber (7636)Aloysius J. Wrape Iii (7540)

Attachment to 162-13763 Page 1 of 4Attachment Near End of Cycle (EOC) MTC Elimination Informational Benchmark L Digitally signed by Leland, Scotteland, Scot .(Zo,0o,)_ I _ cn=L elanndh, Scott(Z~oStOlI (Z05601, aminthe athor of this(Z05601)

Date: 2013 3.0.1 12:02:24

-07'00'Prepared By:Scott LelandMcDonald, Digitally signed by McDonald, WilliamRFZ99508)

W illia m /tN: cn=Mconaid.

William F(Z99508) save reviewed this documentF(Z99508)

Date: 2 William McDonaldReviewed By:

Attachment to 162-13763 Page 2 of 4Near EOC MTC Elimination Informational Benchmark Since the licensing of Arizona Public Service Company (APS) to perform its own reload designcalculations, there has been an ongoing effort to replace the CE DIT/ROCS nuclear design packagewith the Studsvik equivalent NRC-approved for Palo Verde CASMO/SIMULATE package.

Thistransition was implemented in such a way as to maintain the current approved CE safety analysismethodology and plant Technical Specifications.

As part of the transition effort, an extensive benchmarking effort was performed to assure that the uncertainties for the Studsvik code suite werewithin the allowances assumed in the CE Safety Analysis methodology.

The CASMO/SIMULATE nuclear code system is now used for the licensing analyses of Palo Verde Units 1, 2, and 3. TheSafety Evaluation Report (SER) for the change in nuclear design methodology (given in Reference 1)approved the use of CASMO/SIMULATE as a replacement for DIT/ROCS for nuclear design andanalysis of Palo Verde.However, it was noted that the SER for CE methodology topical (CE NPSD-91 I-A, Amendment I-A), used by several CE plants to justify elimination of the End-of-Cycle Moderator Temperature Coefficient (EOC MTC) measurement, contained a requirement that if any methodology other thanthe CE methodology were used for the purpose of EOC MTC test elimination, then appropriate Isothermal Temperature Coefficient (ITC) benchmark information should be submitted to the NRC.This letter provides these benchmarks.

Note that this benchmark is being provided for information only. It is Palo Verde's position that the Palo Verde specific SER approving the use ofCASMO/SIMULATE (Reference 1), provides the necessary approval to use CASMO/SIMULATE for all nuclear analysis applications where DIT/ROCS had previously been used. This includes EOCMTC elimination methodology (CE NPSD-91 1-A, Amendment 1-A).A review was conducted of the NRC's approval of Palo Verde's change from DIT/ROCS toCASMO/SIMULATE.

Specifically, the safety evaluation associated with Amendment No. 132 toFacility Operating License No. NPF-41, Amendment No. 132 to Facility Operating License No. NPF-51, and Amendment No. 132 to Facility Operating License No. NPF-74 for the Palo Verde NuclearGenerating

Station, Units 1, 2, and 3, respectively, was reviewed to determine what specific languagethe NRC used to approve acceptability of CASMO/SIMULATE.

The following are direct extractsfrom the NRC's SER:"In its application, the licensee compares the CASMO-4/SIMULA TE-3 predictions ofkey physics parameters against plant data. In this comparison, the licensee used datafirom PVNGS Units 1, 2, and 3 and from critical experiments.

The licensee intends to use the CASMO-4/SIMULATE-3 programs in licensing applications, including calculations for startups, generation of physics input forsafeýy analyses, qualification and quantification of reliability

factors, andapplications to operations and reload sqfety evaluations ofPVNGS Units 1, 2, and 3.The licensee used several cycles of data to benchmark the licensee's CASMO-4/SIMULATE-3 model.for each Unit for a total of 23 cycles, including both initialreload cores. These data covered a varietv of fuel tpes, operating conditions, andcore loading patterns.

The licensee analyzed the plants over a wide range of conditions from cold (ambient) temperature to hot full power operation.

The licensee found good agreement betweenthe measured and the calculated values, as set forth in the attachment to itsapplication.

Attachment to 162-13763 Page 3 of 4For each parameter

compared, a sample mean and standard deviation of theobserved differences were calculated.

Based on the agreement between the measuredand calculated values, the staff has determined that the licensee has validated itsproposed applications of these computer programs for analysis of the PVNGS Units1, 2, and 3."From the regulatory language in the SER for Palo Verde, CASMO/SIMULATE is an acceptable coredesign methodology.

The SER specifically allows the use of CASMO/SIMULATE as a replacement for DIT/ROCS and approves the methodology for steady-state physics calculations for Palo Verde.As noted in the language, there is good agreement between the measured and calculated values.CE NPSD-911-A, Amendment I-A has specific requirements with regard to the ITC/MTCuncertainty of the core design methods.

Specifically, it requires that:a) The ITC/MTC 95/95 uncertainty is less than or equal to 1.6 pcm/°F.b) Sufficient design margin exist to accommodate the uncertainty.

The uncertainty used in theplant safety analyses is 1.6 pcmI°F.c) The variance in the residual error in the ITC prediction from the BOC tests pool with thosefrom the near EOC tests.Benchmarks that were performed in support of the transition of Palo Verde to CASMO/SIMULATE confirm that the MTC predictive uncertainty for CASMO/SIMULATE is within the acceptance valueof 1.6 pcm/°F and the variance at BOC and near EOC pool. The Palo Verde Safety Analyses employa conservative ITC uncertainty of 1.6 pcm/PF.A summary of these benchmarks is documented as Table .1 for informational purposes to show thatCASMO/SIMULATE is acceptable for performing the surveillances described in CE NPSD-91 I-A,Amendment 1-A.Based on the above information, it has been confirmed that the CASMO/SIMULATE code system isan acceptable replacement for the DIT/ROCS code system for the methodology described in CENPSD-91 1-A, Amendment 1-A, and is applicable to all the Palo Verde units. The response to NRCquestion

  1. 4 on Page A3 of CE NPSD-91 1-A, Amendment I-A, "If utilities perform the calculations, what codes will they use?" further substantiates this conclusion.

References:

1. Letter: Jack N. Donohew, Senior Project Manager (NRC) to Gregg R. Overbeck, Senior VicePresident (APS) dated March 20, 2001, "Palo Verde Nuclear Generating Station (PVNGS),Units 1, 2, and 3 -Issuance of Amendments on CASMO-4/SIMULATE-3 (TAC NOS.MA9279, MA9280, and MA9281)."
2. CE NPSD-9 11-A and Amendment I-A, "Analysis of Moderator Temperature Coefficients inSupport of Change in the Technical Specifications End-of-Cycle Negative MTC Limits,"September 15, 2000.

Attachment to 162-13763 Page 4 of 4Table 1Comparison of CASMO/SIMULATE and DIT/ROCS ITC Benchmarks (Difference between Measurement and Prediction)

Code Package:

Number of Standard Deviation K Multiplier 95/95 Reference Measurements Tolerance LimitCASMO/SIMULATE 70 0.066x10-4 Ap/F 2.299 0.152x10-4 Ap/°F Reference IDIT/ROCS 71 0.077x10-4Ap/°F 1.987 0.153x104Ap/0F Reference 2

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