ML11329A003

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Proposed License Amendment and Exemption Request for Use of Optimized Zirlo Rod Cladding
ML11329A003
Person / Time
Site: Millstone Dominion icon.png
Issue date: 11/17/2011
From: Stoddard D
Dominion, Dominion Nuclear Connecticut
To:
Document Control Desk, Office of Nuclear Reactor Regulation
References
11-598
Download: ML11329A003 (31)
v • d • e


Text

Dominion Nucear Connecticut, Inc.o 5000 Dominion Boulevard, Glen Allen, Virginia 23060 4 Dominion Web Address: www.dom.com November 17, 2011 U.S. Nuclear Regulatory Commission Serial No.11-596 Attention: Document Control Desk NSSL/MAE RO Washington, DC 20555 Docket No. 50-423 License No. NPF-49 DOMINION NUCLEAR CONNECTICUT, INC.

MILLSTONE POWER STATION UNIT 3 PROPOSED LICENSE AMENDMENT AND EXEMPTION REQUEST FOR USE OF OPTIMIZED ZIRLO FUEL ROD CLADDING Pursuant to 10 CFR 50.90, Dominion Nuclear Connecticut, Inc. (DNC) requests an amendment, in the form of changes to the Technical Specifications (TS) to Facility Operating License Number NPF-49 for Millstone Power Station Unit 3 (MPS3). TS 5.3.1, "Reactor Core, Fuel Assemblies," describes the reactor core fuel assemblies, and identifies, in part, zircaloy-4, and ZIRLO as an acceptable fuel rod cladding material. The proposed change will add Optimized ZIRLOTM as an allowable fuel rod cladding material.

In addition, the proposed change will add the Westinghouse topical report on Optimized ZIRLOTM to TS 6.9.1.6.b, "Core Operating Limits Report (COLR)," which lists analytical methods used to determine the core operating limits. These changes are consistent with the U.S. Nuclear Regulatory Commission (NRC) allowed use of Optimized ZIRLOTM fuel cladding material as documented in the Safety Evaluation included in Addendum 1-A to Topical Report WCAP-12610-P-A & CENPD-404-P-A, "Optimized ZIRLOTM.

Additionally, DNC is proposing a non-technical change in the form of a revision to the title of Reference 8 in TS 6.9.1.6.b to correct a typographical error. A discussion of the proposed changes is included in Attachment 1. The marked-up TS pages are included in .

To support the change related to the use of Optimized ZIRLOTM and pursuant to 10 CFR 50.12, DNC is also requesting an exemption from certain requirements of 10 CFR 50.46, "Acceptance Criteria for Emergency Core Cooling Systems for Light Water Nuclear Power Reactors," and Appendix K to 10 CFR 50.46, "ECCS Evaluation Models," for MPS3. The exemption request relates solely to the specific types of cladding material specified in these regulations for use in light water reactors. As written, the regulations presume use of either Zircaloy or ZIRLO fuel rod cladding. The exemption request is required since Optimized ZIRLOTM has a slightly different composition than Zircaloy or standard ZIRLO.

The exemption request is included as Attachment 3.

The NRC has approved the use of Optimized ZIRLOTM fuel rod cladding at Arkansas Nuclear One, Unit 2 (ML080370014) and Waterford Steam Electric Station Unit 3 (ML080380004). Similar changes have also been approved for Surry Power Station Units 1 and 2 (ML103360256, ML103570192 and ML103481056), and North Anna Power Station Units 1 and 2 (ML110601196 and ML110600388).

Serial No.11-596 Docket No. 50-423 Proposed LAR- Optimized ZIRLO Page 2 of 3 DNC requests approval of the proposed amendment by November 18, 2012 to support the core designs for the MPS3 Cycle 16 core reload which is scheduled to begin in the spring of 2013. Once approved, the amendment will be implemented within 60 days.

If you have any questions regarding this submittal, please contact W. D. Craft at (804) 273-4687.

Sincerely, Daniel G. Stoddard Senior Vice President - Nuclear Operations COMMONWEALTH OF VIRGINIA

)

COUNTY OF HENRICO The foregoing document was acknowledged before me, in and for the County and Commonwealth aforesaid, today by Daniel G. Stoddard, who is Senior Vice President - Nuclear Operations of Virginia Electric and Power Company. He has affirmed before me that he is duly authorized to execute and file the foregoing document in behalf of that Company, and that the statements in the document are true to the best.of his knowledge and belief.

Acknowledged before me this L..day of , 2011.

My Commission Expires: -2015 Nota Public Commitments made in this letter:

1. Dominion Nuclear Connecticut, Inc. (DNC) will ensure that the Conditions and Limitations of the NRC Safety Evaluation for Optimized ZIRLOTM, as addressed in Attachment 1, are met prior to the use of Optimized ZIRLOTM in a reload cycle as part of the core reload process for Millstone Power Station Unit 3.
2. Dominion Nuclear Connecticut, Inc. (DNC) will confirm that Westinghouse has provided the NRC additional confirmatory data associated with lead test assembly programs at other facilities, as available, prior to the use of Optimized ZIRLOTM in a reload cycle.

Attachments:

1. Discussion of Technical Specifications Changes
2. Marked-up Technical Specifications Pages
3. Exemption Request

Serial No.11-596 Docket No. 50-423 Proposed LAR- Optimized ZIRLO Page 3 of 3 cc: U.S. Nuclear Regulatory Commission Region I 475 Allendale Road King of Prussia, PA 19406-1415 C. J. Sanders Project Manager - Millstone Power Station U.S. Nuclear Regulatory Commission One White Flint North 11555 Rockville Pike Mail Stop O-8B3 Rockville, MD 20852-2738 NRC Senior Resident Inspector (w/o attachments)

Millstone Power Station Director Bureau of Air Management Monitoring and Radiation Division Department of Environmental Protection 79 Elm Street Hartford, CT 06106-5127

Serial No.11-596 Docket No. 50-423 Proposed LAR - Optimized ZIRLO Attachment 1 Attachment 1 Discussion of Technical Specifications Changes DOMINION NUCLEAR CONNECTICUT, INC.

MILLSTONE POWER STATION UNIT 3

Serial No.11-596 Docket No. 50-423 Proposed LAR - Optimized ZIRLO Attachment 1 Page 1 of 16 Discussion of Technical Specifications Changes Table of Contents 1.0 Summary Description ........................................................................................ 2 2.0 Detailed Description of Proposed Technical Specifications Changes .......... 2 2.1 Design Features - Technical Specification 5.3.1 (Reactor Core, Fuel Assem blies) ............................................................................................2 2.2 Administrative Controls - Technical Specification 6.9.1.6.b (Core Operating Lim its Report) ......................................................................... 3 3.0 Discussion .......................................................................................................... 5 3.1 Background Information ........................................................................... 5 3.2 Lead Test Assembly Program Involving Optimized ZIRLOTm at MPS3 ........................................................................................................... 5 4.0 Technical Evaluation ......................................................................................... 6 5.0 Regulatory Evaluation ..................................................................................... 10 5.1 Applicable Regulatory Requirements and Criteria ............................. 10 5.2 No Significant Hazards Consideration ................................................ 10 5.3 Precedents ............................................................................................ 13 5.4 Conclusion ............................................................................................ 14 6.0 Environmental Considerations ....................................................................... 14 7.0 References ....................................................................................................... 15

Serial No.11-596 Docket No. 50-423 Proposed LAR - Optimized ZIRLO Attachment 1 Page 2 of 16 1.0 Summary Description Dominion Nuclear Connecticut, Inc. (DNC) proposes to change the Millstone Power Station Unit 3 (MPS3) Technical Specifications (TS) to allow the use of an additional fuel rod cladding material, Optimized ZIRLOTM. The current acceptable fuel rod cladding materials are identified in TS 5.3.1, "Reactor Core, Fuel Assemblies." A change to the References listed in TS 6.9.1.6.b, "Core Operating Limits Report (COLR)," is also proposed. This change adds the topical report for Optimized ZIRLOTM to the current list of NRC approved analytical methods used to determine the core operating limits.

Additionally, DNC is proposing a non-technical change in the form of a revision to the title of Reference 8 in TS 6.9.1.6.b to correct a typographical error. The typographical error was previously introduced in Amendment 218, dated March 9, 2004.

In addition to the proposed Technical Specifications changes, an exemption from the provisions of 10 CFR 50.46, "Acceptance Criteria for Emergency Core Cooling Systems for Light Water Nuclear Power Reactors," and Appendix K to 10 CFR Part 50, "ECCS Evaluation Models," is required to support the use of Optimized ZIRLOTM as a fuel rod cladding material. The exemption request is provided in Attachment 3 to this submittal.

DNC currently plans to use fuel assemblies containing Optimized ZIRLOTM fuel rod cladding starting with the new fuel for MPS3 Cycle 16 which is scheduled to begin in the spring of 2013.

2.0 Detailed Description of Proposed Technical Specifications Changes 2.1 Design Features- Technical Specification 5.3.1 (Reactor Core, Fuel Assemblies)

Technical Specification 5.3.1 is being revised to add the Westinghouse Electric Company, LLC (Westinghouse) Optimized ZIRLOTM alloy to the list of materials that may be used as the fuel rod cladding in MPS3 fuel assemblies. The proposed revised specification (with changes in bold) reads as follows:

5.3.1 The core shall contain 193 fuel assemblies. Each fuel assembly shall consist of 264 zircaloy-4, ZIRLO, or Optimized ZIRLOTM clad fuel rods with an initial composition of natural uranium dioxide or a maximum nominal enrichment of 5.0 weight percent U-235 as fuel material. Limited substitutions of zircaloy-4, ZIRLO or stainless steel filler rods for fuel rods, in accordance with NRC-approved applications of fuel rod configurations, may be used. Fuel assembly configurations shall be limited to those fuel designs that have been analyzed with applicable NRC staff-approved codes and methods, and shown by test or cycle-specific reload analyses to comply with all fuel safety design bases. Each fuel rod shall have a nominal active fuel length of 144 inches. A limited number of lead test assemblies that have not completed representative testing may be placed in nonlimiting core regions.

Serial No.11-596 Docket No. 50-423 Proposed LAR - Optimized ZIRLO Attachment 1 Page 3 of 16 2.2 Administrative Controls - Technical Specification 6.9.1.6.b (Core Operating Limits Report)

Technical Specification 6.9.1.6.b currently includes a list of 18 documents that define the NRC reviewed and approved methods used to determine the core operating limits for MPS3. The proposed revision to this list would add a Westinghouse topical report related to Optimized ZIRLOTM as Reference 19 (in bold). Reference 8 of the list would also be revised to correct a typographical error in the title by deleting the number "17" (in bold).

The typographical error was introduced -in Amendment 218, dated March 9, 2004.

The proposed changes are as follows:

6.9.1.6.b The analytical methods used to determine the core operating limits shall be those previously reviewed and approved by the NRC in:

1. WCAP-9272-P-A, "WESTINGHOUSE RELOAD SAFETY EVALUATION METHODOLOGY," & Proprietary). (Methodology for Specifications 2.1.1.1--

Departure from Nucleate Boiling Ratio, 2.1.1.2--Peak Fuel Centerline Temperature, 3.1.1.3--Moderator Temperature Coefficient, 3.1.3.5--Shutdown Bank Insertion Limit, 3.1.3.6--Control Bank Insertion Limits, 3.2.1--AXIAL FLUX DIFFERENCE, 3.2.2--Heat Flux Hot Channel Factor, 3.2.3--Nuclear Enthalpy Rise Hot Channel Factor, 3.1.1.1.1, 3.1.1.1.2, 3.1.1.2 -- SHUTDOWN MARGIN, 3.9.1.1-- Boron Concentration.)

2. T. M. Anderson to K. Kniel (Chief of Core Performance Branch, NRC), January 31, 1980--

Attachment:

Operation and Safety-Analysis Aspects of an Improved Load Follow Package.

3. NUREG-800, Standard Review Plan, U.S. Nuclear Regulatory Commission, Section 4.3, Nuclear Design, July 1981 Branch Technical Position CPB 4.3-1, Westinghouse Constant Axial Offset Control (CAOC), Revision 2, July 1981.
4. WCAP-10216-P-A-RIA, "RELAXATION OF CONSTANT AXIAL OFFSET CONTROL FQ SURVEILLANCE TECHNICAL SPECIFICATION," (W Proprietary). (Methodology for Specifications 3.2.1--AXIAL FLUX DIFFERENCE

[Relaxed Axial Offset Control] and 3.2.2--Heat Flux Hot Channel Factor [W(z) surveillance requirements for FQ Methodology].)

5. WCAP-12945-P-A, "CODE QUALIFICATION DOCUMENT FOR BEST ESTIMATE LOCA ANALYSIS," (W__Proprietary). (Methodology for Specification 3.2.2--Heat Flux Hot Channel Factor.)
6. WCAP-16009-P-A, "REALISTIC LARGE-BREAK LOCA EVALUATION METHODOLOGY USING THE AUTOMATED STATISTICAL TREATMENT OF UNCERTAINTY METHOD (ASTRUM)," &_Proprietary). (Methodology for Specification 3.2.2--Heat Flux Hot Channel Factor.)

Serial No.11-596 Docket No. 50-423 Proposed LAR - Optimized ZIRLO Attachment 1 Page 4 of 16

7. WCAP-1 1946, "Safety Evaluation Supporting a More Negative EOL Moderator Temperature Coefficient Technical Specification for the Millstone Nuclear Power Station Unit 3," (_WProprietary).
8. WCAP-10054-P-A, "WESTINGHOUSE SMALL BREAK ECCS EVALUATION MODEL 4-* USING THE NOTRUMP CODE," &WProprietary).(Methodology for Specification 3.2.2 - Heat Flux Hot Channel Factor.)
9. WCAP-10079-P-A, "NOTRUMP - A NODAL TRANSIENT SMALL BREAK AND GENERAL NETWORK CODE," &__Proprietary). (Methodology for Specification 3.2.2 - Heat Flux Hot Channel Factor.)
10. WCAP-1 2610, "VANTAGE+ Fuel Assembly Report," &_Proprietary).

(Methodology for Specification 3.2.2 - Heat Flux Hot Channel Factor.)

11. Letter from V. L. Rooney (USNRC) to J. F. Opeka, "Safety Evaluation for Topical Report, NUSCO-1 52, Addendum 4, 'Physics Methodology for PWR Reload Design,' TAC No. M91815," July 18, 1995.
12. Letter from E. J. Mroczka to the USNRC, "Proposed Changes to Technical Specifications, Cycle 4 Reload Submittal - Boron Dilution Analysis," B13678, December 4, 1990.
13. Letter from D. H. Jaffe (USNRC) to E. J. Mroczka, "Issuance of Amendment (TAC No. 77924)," March 11, 1991.
14. Letter from M. H. Brothers to the USNRC, "Proposed Revision to Technical Specification, SHUTDOWN MARGIN Requirements and Shutdown Margin Monitor OPERABILITY for MODES 3, 4, and 5 (PTSCR 3-16-97), B16447, May 9,1997.
15. Letter from J. W. Anderson (USNRC) to M. L. Bowling (NNECO), "Issuance of Amendment - Millstone Nuclear Power Station, Unit No. 3 (TAC No. M98699),"

October 21, 1998.

16. WCAP-8301, "LOCTA-IV Program: Loss-of-Coolant Transient Analysis."
17. WCAP-10054-P-A, Addendum 2, "Addendum to the Westinghouse Small Break ECCS Evaluation Model Using the NOTRUMP Code: Safety Injection into the Broken Loop and COSI Condensation Model."
18. WCAP-8745-P-A, "Design Bases for the Thermal Overpower AT and Thermal Overtemperature DT Trip Functions," (Westinghouse Proprietary Class 2).

(Methodology for Specifications 2.1.1 and 2.2.1.)

TM 19.WCAP-12610-P-A & CENPD-404-P-A, Addendum 1-A, "Optimized ZIRLO ,"

(W Proprietary). (Methodology for Specification 3.2.2 - Heat Flux Hot Channel Factor.)

Serial No.11-596 Docket No. 50-423 Proposed LAR - Optimized ZIRLO Attachment 1 Page 5 of 16 3.0 Discussion 3.1 Background Information As the nuclear industry has pursued longer operating cycles with increased fuel discharge burnup and fuel duty, the corrosion performance requirements for the nuclear fuel cladding have become more demanding. Westinghouse developed the Optimized ZIRLOTM cladding material to meet these needs and provide a reduced corrosion rate while maintaining the benefits of mechanical strength and resistance to accelerated corrosion from abnormal chemistry conditions. In addition, fuel rod internal pressures (resulting from the increased fuel duty, use of integral fuel burnable absorbers, and corrosion/temperature feedback effects) have become more limiting with respect to fuel rod design criteria.

Reducing the associated corrosion buildup minimizes temperature feedback effects, thus providing additional margin to the fuel rod internal pressure design criterion.

Optimized ZIRLOTM is described in Westinghouse topical report WCAP-12610-P-A &

CENPD-404-P-A, Addendum 1-A, "Optimized ZIRLOTM (Reference 1). As noted in Reference 2, Optimized ZIRLOTm differs from standard ZIRLO in two respects: 1) lower tin content; and 2) microstructure. The differences in tin content and microstructure can lead to differences in some material properties.

The NRC has approved the use of Optimized ZIRLOTM fuel cladding based upon the following:

1) Similarities to standard ZIRLO,
2) Demonstrated material performance as documented in Reference 1 and in Westinghouse responses to NRC requests for additional information, and
3) A commitment to provide irradiated data and validate fuel performance models ahead of burnups achieved in batch applications.

The NRC safety evaluation for the Reference 1 topical report identified ten Conditions and Limitations that are applicable to the use of Optimized ZIRLOTM. Compliance with these Conditions and Limitations is discussed in Section 4.0 below.

The NRC has approved use of Optimized ZIRLOTM fuel rod cladding material in reload quantities for Arkansas Nuclear One, Unit 2 and Waterford Unit 3. Additionally, Dominion has received NRC approval for the use of Optimized ZIRLOTM at North Anna Power Station, Units 1 and 2 (References 3 and 4) and Surry Power Station, Units 1 and 2 (References 5, 6 and 7). DNC currently plans to use Optimized ZIRLOTM as the fuel rod cladding material for MPS3 reloads starting with the new fuel introduced for Cycle 16 which is scheduled to begin in the spring of 2013.

3.2 Lead Test Assembly Program Involving Optimized ZIRLOTM at MPS3 MPS3 has previously used the Optimized ZIRLOTM fuel rod cladding as part of a lead test assembly (LTA) program during Cycles 10, 11 and 12. The LTA program involved the use

Serial No.11-596 Docket No. 50-423 Proposed LAR - Optimized ZIRLO Attachment 1 Page 6 of 16 of eight next generation fuel (NGF) LTAs which, among other design features, used the Optimized ZIRLOTM cladding material. Related to the LTA program, and specifically to the use of Optimized ZIRLOTM, DNC requested an exemption to the cladding material specified in 10 CFR 50.44, 10 CFR 50.46, and 10 CFR 50 Appendix K, pursuant to 10 CFR 50.12 (References 8 and 9). The NRC subsequently approved DNC's exemption request in Reference 10, allowing for the use of up to 8 NGF LTAs with Optimized ZIRLOTM cladding in the Cycle 10, 11 and 12 cores.

4.0 Technical Evaluation Westinghouse topical report WCAP-12610-P-A & CENPD-404-P-A, Addendum 1-A, "Optimized ZIRLOTM (Reference 1), provides the details and results of material testing of Optimized ZIRLOTM compared to standard ZIRLO as well as the material properties to be used in various models and methodologies when analyzing Optimized ZIRLOTM The associated NRC Safety Evaluation (SE) (Reference 2) contains ten Conditions and Limitations licensees must comply with when referencing the Optimized ZIRLOTM topical report. These ten Conditions and Limitations are listed below and are addressed relative to this MPS3 submittal.

1. Until rulemaking to 10 CFR Part 50 addressingOptimized ZIRLOTM has been completed, implementation of Optimized ZIRLOTM fuel clad requiresan exemption from 10 CFR 50.46 and 10 CFR Part 50 Appendix K.

RESPONSE: A request for the required exemption from 10 CFR 50.46 and 10 CFR Part 50 Appendix K is provided in Attachment 3 to this submittal.

2. The fuel rod burnup limit for this approvalremains at currently establishedlimits: 62 GWd/MTU for Westinghouse fuel designs and 60 GWd/MTU for CE fuel designs.

RESPONSE: For any fuel using Optimized ZIRLOTM fuel rod cladding, the maximum fuel rod burnup limit for Westinghouse fuel designs will continue to be 62 GWd/MTU until such time that a new fuel rod burnup limit is approved for use.

3. The maximum fuel rod waterside corrosion,as predicted by the best-estimate model, will [satisfy proprietarylimits included in the topical report and proprietary version of the safety evaluation]of hydrides for all locations of the fuel rod.

RESPONSE: The maximum fuel rod waterside corrosion for fuel using Optimized ZIRLOTM fuel rod cladding will be confirmed to be less than the specified proprietary limits for all locations of the fuel rod. Evaluations are performed to confirm that the appropriate corrosion limits are satisfied as part of the normal reload design process performed under 10 CFR 50.59.

4. All the conditions listed in previous NRC SE approvals for methodologies used for standardZIRLO and Zircaloy-4 fuel analysis will continue to be met, except that

Serial No.11-596 Docket No. 50-423 Proposed LAR - Optimized ZIRLO Attachment 1 Page 7 of 16 the use of Optimized ZIRLOTM cladding in addition to standardZIRLO and Zircaloy-4 cladding is now approved.

RESPONSE: The fuel analysis of Optimized ZIRLOTM fuel rod cladding will continue to meet all conditions associated with approved methods. For MPS3, confirmation that these conditions are met is currently required as part of the normal reload design process.

5. All methodologies will be used only within the range for which ZIRLO and Optimized ZIRLOTM data were acceptable and for which the verificationsdiscussed in Addendum 1 and responses to RAIs were performed.

RESPONSE: The application of ZIRLO and Optimized ZIRLOTM in approved methodologies will be made consistent with the approach accepted in WCAP-12610-P-A & CENPD-404-P-A, Addendum 1-A "Optimized ZIRLOTM, July 2006.

For MPS3, confirmation that these conditions are met is currently required as part of the normal reload design process. Specifically, all methodologies will be used only within the range for which ZIRLO and Optimized ZIRLOTM data were acceptable and for which the verifications discussed in Addendum 1 and responses to RAIs were performed.

6. The licensee is requiredto ensure that Westinghouse has fulfilled the following commitment: Westinghouse shall provide the NRC staff with a letter(s) containing the following information (Based on the schedule described in response to RAI #3

[Reference 3]):

a. Optimized ZIRLOTM LTA data from Byron, Calvert Cliffs, Catawba, and Millstone.
i. Visual ii. Oxidation of fuel rods iii. Profilometry iv. Fuel rod length
v. Fuel assembly length
b. Using the standardand Optimized ZIRLOTM database including the most recent L TA data, confirm applicabilitywith currently approved fuel performance models (e.g., measured vs. predicted).

Confirmation of the approved models' applicabilityup through the projectedend of cycle burnup for the Optimized ZIRLOTM fuel rods must be completed priorto their initial batch loading and priorto the startup of subsequent cycles. Forexample, prior to the first batch applicationof Optimized ZIRL OT, sufficient L TA data may only be available to confirm the models' applicabilityup through 45 GWd/MTU. In this example, the licensee would need to confirm the models up through the end of the initial cycles. Subsequently, the licensee would need to confirm the models, based upon the latest LTA data, priorto re-insertingthe Optimized ZIRLOTM fuel rods in future cycles. Based upon the L TA schedule, it is expected that this issue may only

Serial No.11-596 Docket No. 50-423 Proposed LAR - Optimized ZIRLO Attachment I Page 8 of 16 be applicable to the first few batch implementations since sufficient L TA data up through the burnup limit should be available within a few years.

RESPONSE: Westinghouse has provided the NRC with information related to test data and models (References 11-15).

Measured data from LTA programs and favorable results from visual examinations of once, twice, and thrice-burned LTAs confirm, for three cycles of operation, that the current fuel performance models are applicable for Optimized ZIRLOTM clad fuel rods. Westinghouse will continue to provide additional data from the Optimized ZIRLOTM LTA programs to the NRC. DNC will confirm that the requirements of this condition will be met as it applies to MPS3.

7. The licensee is requiredto ensure that Westinghouse has fulfilled the following commitment: Westinghouse shallprovide the NRC staff with a letter containingthe following information (Basedon the schedule described in response to RAI #11

[Reference 3D):

a. Vogtle growth and creep data summary reports.
b. Using the standardand Optimized ZIRLOTM databaseincluding the most recent Vogtle data, confirm applicabilitywith currently approved fuel performance models (e.g., level of conservatism in W rod pressure analysis, measured vs. predicted, predictedminus measured vs. tensile and compressive stress).

Confirmation of the approved models' applicabilityup through the projected end of cycle burnup for the Optimized ZIRLOTM fuel rods must be completed priorto their initial batch loading and prior to the startup of subsequent cycles. For example, priorto the first batch applicationof Optimized ZIRLOTM, sufficient L TA data may only be available to confirm the models' applicabilityup through 45 GWd/MTU. In this example, the licensee would need to confirm the models up through the end of the initial cycles. Subsequently, the licensee would need to confirm the models, based upon the latest L TA data, priorto re-insertingthe Optimized ZIRLOTM fuel rods in future cycles. Based upon the L TA schedule, it is expected that this issue may only be applicableto the first few batch implementations since sufficient L TA data up through the burnup limit should be available within a few years.

RESPONSE: Westinghouse has provided the NRC with information related to test data and models (References 11-15).

The data from three cycles of operation has been evaluated, and the fuel rod creep models from fuel rod design codes have been used to predict the growth and creep performance of the samples. This information was provided to the NRC in the most recent informational letter (Reference 15). DNC will confirm that the requirements of this condition will be met as it applies MPS3.

Serial No.11-596 Docket No. 50-423 Proposed LAR - Optimized ZIRLO Attachment 1 Page 9 of 16

8. The licensee shall account for the relative differences in unirradiatedstrength (YS and UTS) between Optimized ZIRLOTM and standardZIRLO in cladding and structuralanalyses until irradiateddata for Optimized ZIRLOTM have been collected and provided to the NRC staff
a. For the Westinghouse fuel design analyses:
i. The measured, unirradiatedOptimized ZIRLOTM strengths shall be used for the BOL analyses.

ii. Between BOL up to a radiationfluence of 3..Ox1O 2 1 n/cm 2 (E>IMeV), pseudo-irradiatedOptimized ZIRLOTM strength set equal to linearinterpolation between the following two strength level points: At zero fluence, strength of Optimized ZIRLOTM equal to measured strength of Optimized ZIRLO and at a fluence of 3.Ox l O n/cm 2 (E>I Me V), irradiatedstrength of standard ZIRLO at the fluence of 3.Ox O21 n/cm 2 (E>IMeV) minus 3 ksi.

iii. During subsequent irradiationfrom 3.Ox 1021 n/cm 2 up to 12x1021 n/cm2 , the differences in strength (the difference at a fluence of 3x10 21 n/cm 2 due to tin content) shall be decreasedlinearly such that the pseudo-irradiated Optimized ZIRLOTM strengths will saturate at the same properties as standardZIRLO at 12x 1021 n/cm2 .

b. For the CE fuel design analyses, the measured, unirradiatedOptimized ZIRLOTM strengths shall be used for all fluence levels (consistent with previously approved methods).

RESPONSE: MPS3 uses a Westinghouse fuel design, and therefore, Condition 8.b does not apply.

The fuel analysis of Optimized ZIRLOTM clad rods will use the yield strength and ultimate tensile strength as modified per Conditions 8.a.i, 8.a.ii, and 8.a.iii until such time that irradiated data for Optimized ZIRLOTM strengths have been collected and provided to the NRC. DNC will confirm that the requirements of this condition will be met as it applies to MPS3.

9. As discussed in response to RAI #21 (Reference 3), for plants introducing Optimized ZIRLOTm that are licensed with LOCBART or STRIKIN-II and have a limiting PCT that occurs during blowdown or early reflood, the limiting LOCBART or STRIKIN-II calculation will be rerun using the specified Optimized ZIRLOTM material properties. Although not a condition of approval, the NRC staff strongly recommends that, for future evaluations, Westinghouse update all computer models with Optimized ZIRLOTM specific materialproperties.

RESPONSE: MPS3 is not licensed with LOCBART or STRIKIN-II. Therefore, this Condition does not apply.

Serial No.11-596 Docket No. 50-423 Proposed LAR - Optimized ZIRLO Attachment 1 Page 10 of 16

10. Due to the absence of high temperature oxidation data for Optimized ZIRLOTM the Westinghouse coolabilitylimit on PCT during the locked rotorevent shall be

[proprietarylimit included in topical report andproprietaryversion of safety evaluation].

RESPONSE: The Westinghouse limit on PCT during the locked rotor event will be assessed relative to the PCT limit included in the topical report and safety evaluation as part of the normal reload design process.

5.0 Regulatory Evaluation 5.1 Applicable Regulatory Requirements and Criteria The NRC has previously allowed the use of Optimized ZIRLOTM fuel cladding material in Westinghouse Original Equipment Manufacturer (OEM) reactors provided that the licensees ensure compliance with the Conditions and Limitations set forth in the NRC Safety Evaluation (SE) for Westinghouse topical report WCAP-1 2610-P-A & CENPD-404-P-A, Addendum 1-A, "Optimized ZIRLOTM,,' July 2006 (Reference 1). The Westinghouse topical report provides the details and results of material testing of Optimized ZIRLOTM compared to standard ZIRLO, as well as the material properties to be used in various models and methodologies when analyzing Optimized ZIRLOTM. Each of the Conditions and Limitations were specifically addressed for their applicability to MPS3 in the Technical Evaluation, Section 4.0 of this LAR. In summary:

" the exemption request required by Condition and Limitation 1 has been prepared and is provided as Attachment 3 to this LAR;

" Westinghouse has provided the NRC with information related to test data and models to address Condition and Limitations 6 and 7;

  • Condition and Limitation 9 is not applicable to MPS3 because MPS3 does not use and is not licensed to use the noted computer codes; and

" the remaining Conditions and Limitations for the insertion of fuel rods with Optimized ZIRLOTM cladding will be addressed in evaluations performed under 10 CFR 50.59 to support normal core reload activities.

5.2 No Significant Hazards Consideration DNC 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 change involve a significant increase in the probability or consequences of an accident previously evaluated?

Serial No.11-596 Docket No. 50-423 Proposed LAR - Optimized ZIRLO Attachment 1 Page 11 of 16 Response: No.

The proposed Technical Specifications changes are: 1) adding Optimized ZIRLOTM to the allowable or approved cladding materials to be used at MPS3, and

2) correcting a typographical error in the title of Reference 8 in Technical 0 Specification (TS) 6. 9.1.6.b. The proposed change of adding a cladding material does not result in an increase to the probability or consequences of an accident previously evaluated. Technical Specification 5.3.1 addresses the fuel assembly design, and currently specifies that "Each assembly shall consist of a matrix of Zircaloy or ZIRLO fuel rods...". The proposed change will add Optimized ZIRLOIm to the approved fuel rod cladding materials listed in this technical specification. In addition, a reference to the topical report for Optimized ZIRLOTM WCAP-12610-P-A and CENPD-404-P-A, Addendum 1-A, will be added to the listing of approved methods used to determine the core operating limits for MPS3 provided in Technical Specification 6.9.1.6.b.

Westinghouse topical report WCAP-12610-P-A & CENPD-404-P-A, Addendum 1-A, "Optimized ZIRLOTM," provides the details and results of material testing of Optimized ZIRLOTM compared to standard ZIRLO, as well as the material properties to be used in various models and methodologies when analyzing Optimized ZIRLOTM. As the nuclear industry pursues longer operating cycles with increased fuel discharge burnup and fuel duty, the corrosion performance requirements for the nuclear fuel cladding become more demanding. Optimized ZIRLOTM was developed to meet these industry needs by providing a reduced corrosion rate while maintaining the composition and physical properties, such as mechanical strength, similar to standard ZIRLO. In addition, margin to the fuel rod design criterion on fuel rod internal pressure has been impacted by increased fuel duty, use of integral fuel burnable absorbers, and corrosion/temperature feedback effects. Reducing the associated corrosion buildup reduces temperature feedback effects, providing additional margin to the fuel rod internal pressure design criterion. The fuel will continue to satisfy the pertinent design basis operating limits, so cladding integrity is maintained. There are no changes that will adversely affect the ability of existing components and systems to mitigate the consequences of any accident. Addition of Optimized ZIRLOTM to the allowable cladding materials for MPS3 therefore does not result in a significant increase in the probability or consequences of an accident previously evaluated.

The NRC has previously approved use of Optimized ZIRLOTM fuel cladding material in Westinghouse fueled reactors provided that licensees ensure compliance with the Conditions and Limitations set forth in the NRC Safety Evaluation for the topical report. Confirmation that these Conditions are satisfied is performed under 10 CFR 50.59 as part of the normal core reload process.

The change to the title of Reference 8 in Technical Specification 6. 9.1.6.b is administrative in nature and does not alter any of the requirements of the affected TS. The proposed change does not modify any plant equipment and does not

Serial No.11-596 Docket No. 50-423 Proposed LAR - Optimized ZIRLO Attachment 1 Page 12 of 16 impact any failure modes that could lead to an accident. Additionally, the proposed change has no effect on the consequence of any analyzed accident since the change does not affect any equipment related to accident mitigation.

Based on this discussion, the proposed change does not significantly increase the probability or consequences of an accident previously evaluated.

2. Does the proposed change create the possibility of a new or different kind of accident from any accident previously evaluated?

Response: No.

The proposed Technical Specifications change adds Optimized ZIRLOTM to the approved fuel rod cladding materials that may be used at MPS3. Optimized ZIRLOTM was developed to provide a reduced cladding corrosion rate while maintaining the benefits of mechanical strength and resistance to accelerated corrosion from potential abnormal chemistry conditions. The fuel rod design bases are established to satisfy the general and specific safety criteria addressed in the MPS3 Final Safety Analysis Report (FSAR), Chapter 15 (Accident Analyses). The fuel rods are designed to prevent excessive fuel temperatures, excessive fuel rod internal gas pressures due to fission gas releases, and excessive cladding stresses and strains. Westinghouse topical report WCAP-12610-P-A & CENPD-404-P-A, Addendum 1-A, "Optimized ZIRLOTM, provides the details and results of material testing of Optimized ZIRLOTM compared to standard ZIRLO, as well as the material properties to be used in various models and methodologies when analyzing Optimized ZIRLOTM. The original fuel design basis requirements have been maintained. No new single failure mechanisms will be created, and there are no alterations to plant equipment or procedures that would introduce any new or unique operational modes or accident precursors.

Therefore, the proposed changes to the MPS3 TSs related to the use of Optimized ZIRLOTM do not create the possibility of a new or different kind of accident or malfunction from those previously evaluated within the FSAR.

The change to the title of Reference 8 in Technical Specification 6. 9.1.6.b is administrative in nature. It does not modify any plant equipment and there is no impact on the capability of the existing equipment to perform their intended functions. No system setpoints are being modified and no changes are being made to the method in which plant operations are conducted. No new failure modes are introduced by the proposed changes. The proposed change does not introduce accident initiators or malfunctions that would cause a new or different kind of accident. Therefore, the proposed change does not create the possibility of a new or different kind of accident from any accident previously evaluated.

3. Does the proposed change involve a significant reduction in a margin of safety?

Response: No.

Serial No.11-596 Docket No. 50-423 Proposed LAR - Optimized ZIRLO Attachment 1 Page 13 of 16 The cladding materials used for fuel rods are designed and tested to prevent excessive fuel temperatures, excessive fuel rod internal gas pressures due to fission .as releases, and excessive cladding stresses and strains. Optimized ZIRLO was developed to meet these needs while providing a reduced cladding corrosion rate and maintaining the benefits of mechanical strength and resistance to accelerated corrosion from potential abnormal chemistry conditions. Reducing the associated corrosion buildup reduces temperature feedback effects, providing additional margin to the fuel rod internal pressure design criterion. Westinghouse topical report WCAP-12610-P-A & CENPD-404-P-A, Addendum 1-A, "Optimized ZIRLOTM,I' provides the details and results of material testing of Optimized ZIRLOTM compared to standard ZIRLO, as well as the material properties to be used in various models and methodologies when analyzing Optimized ZIRLOTM.

The NRC has previously approved use of the Optimized ZIRLOTM fuel cladding material as detailed in their Safety Evaluation for this topical report. The original fuel design basis requirements have been maintained, and evaluations will be performed under 10 CFR 50.59 for each reload cycle that incorporates Optimized ZIRLOTM cladding to confirm that design and safety limits are satisfied. Therefore, inclusion of Optimized ZIRLOTM as an additional fuel rod cladding material for MPS3 does not result in a significant reduction in margin required to preclude or reduce the effects of an accident or malfunction previously evaluated in the FSAR.

The change to the title of Reference 8 in Technical Specification 6. 9.1.6.b is administrative in nature. This change does not alter any of the requirements of the affected TS. The proposed change does not affect any of the assumptions used in the accident analysis, nor does it affect any operability requirements for equipment important to plant safety. Therefore, the proposed change will not result in a significant reduction in the margin of safety.

Based on the above information, DNC concludes that the proposed license amendment presents no significant hazards consideration under the criteria set forth in 10 CFR 50.92(c) and, accordingly, a finding of no significant hazards consideration is justified.

5.3 Precedents The proposed changes to the MPS3 technical specifications are similar to the following proposed changes that have been submitted to allow use of fuel with Optimized ZIRLOTM fuel cladding:

  • Letter from T. G. Mitchell (Entergy) to USNRC, "License Amendment Request To Allow the Use of Optimized ZIRLOTM Fuel Rod Cladding," 2CAN040703, April 24, 2007, Arkansas Nuclear One, Unit 2. (ML071220267)

" Letter from K. T. Walsh (Entergy) to USNRC, "License Amendment Request To Allow the Use of Optimized ZIRLOTM Fuel Rod Cladding," W3F1-2007-0020, April 24, 2007, Waterford Steam Electric Station, Unit 3. (ML071160348)

Serial No.11-596 Docket No. 50-423 Proposed LAR - Optimized ZIRLO Attachment 1 Page 14 of 16

" Letter from J. B. Archie (SCE&G) to USNRC, "License Amendment Request- LAR 09-00562, "License Amendment Request for Use of Optimized ZIRLOTM Fuel Rod Cladding," RF-09-0068, June 9, 2009, Virgil C. Summer Nuclear Station.

(ML091620072)

  • Letter from J. A. Price (Dominion) to USNRC, "Virginia Electric and Power Company (Dominion), North Anna Power Station Units 1 and 2, Proposed License Amendment and Exemption Request for Use of Optimized ZIRLO Fuel Rod Cladding," Dominion Serial No.10-205, May 6, 2010. (ML101260517)
  • Letter from J. A. Price (Dominion) to USNRC, "Surry Power Station, Units 1 and 2, License Amendment Request for Use of Optimized ZIRLO Fuel Rod Cladding,"

Dominion Serial No.10-074, February 10, 2010. (ML100470738)

The requested license amendments for Arkansas Nuclear One, Unit 2 (ML080370014),

and Waterford 3 (ML080380004) were issued by the NRC in March and April, 2008, respectively.

The requested license amendments for North Anna Power Station, Unit Nos. 1 and 2 were issued by the NRC in March-April 2011 (References 3 and 4).

The requested license amendments for Surry Power Station, Unit Nos. 1 and 2 were issued by the NRC in December 2010 (References 5, 6 and 7).

5.4 Conclusion Based on the considerations discussed above, there is reasonable assurance that (1) the health and safety of the public will not be endangered by the operation of MPS3 with Optimized ZIRLOTM fuel rod cladding, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the requested license amendments will not be inimical to the common defense and security or to the health and safety of the public.

6.0 Environmental Considerations DNC has reviewed the proposed license amendment for environmental considerations.

The proposed license 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 from an environmental assessment as 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.

Serial No.11-596 Docket No. 50-423 Proposed LAR - Optimized ZIRLO Attachment 1 Page 15 of 16 7.0 References

1. WCAP-12610-P-A & CENPD-404-P-A, Addendum 1-A, "Optimized ZIRLOTM, July 2006.
2. Letter from H. N. Berkow (USNRC) to J. A. Gresham (Westinghouse), "Final Safety Evaluation for Addendum 1 to Topical Report WCAP-1 2610-P-A & CENPD-404-P-A, 'Optimized ZIRLOTM' (TAC No. MB8041)," June 10, 2005. (ML051670395)
3. Letter from J. S. Wiebe (USNRC) to D. A. Heacock (Dominion), "North Anna Power Station, Unit Nos. 1 and 2, Exemption from the Requirements of Title 10 of the Code of Federal Regulations, Part 50, Section 50.46 and Appendix K (TAC Nos.

ME3885 and ME3886)," Dominion Serial No.11-182, March 23, 2011.

(ML110600388)

4. Letter from J. S. Wiebe (USNRC) to D. A. Heacock (Dominion), "North Anna Power Station, Unit Nos. 1 and 2, Issuance of Amendments Regarding the Use of Optimized ZIRLOTM Fuel Rod Cladding (TAC Nos. ME3885 and ME3886),"

Dominion Serial No.11-237, April 14, 2011. (ML110601196)

5. Letter from K. Cotton (USNRC) to D. A. Heacock (Dominion), "Surry Power Station, Unit Nos. 1 and 2, Issuance of Amendments Regarding the Use of Optimized ZIRLO Fuel Rod Cladding (TAC NOS. ME3343 and ME3344)," Dominion Serial No.10-669, December 22, 2010. (ML103360256)
6. Letter from K. Cotton (USNRC) to D. A. Heacock (Dominion), "Surry Power Station Unit Nos. 1 and 2, Corrections to Amendments Regarding the Use of Optimized ZIRLO Fuel Rod Cladding (TAC NOS. ME3343 and ME3344," Dominion Serial No.10-755, December 23, 2010. (ML103570192)
7. Letter from K. Cotton (USNRC) to D. A. Heacock (Dominion), " Surry Power Station Unit Nos. 1 and 2 - Exemption from the Requirements of 10 CFR Part 50, Section 10.46 (TAC NOS. ME3343 and ME3344," Dominion Serial No.10-756, December 15, 2010. (ML103481056)
8. Letter from J. A. Price (Dominion) to USNRC, "Millstone Power Station, Unit No. 3, Request for Exemption Pursuant to 10 CFR 50.12, Exemption to the Cladding Material Specified in 10 CFR 50.44, 10 CFR 50.46, and 10 CFR 50 Appendix K,"

Dominion Serial No. B18922, July 1, 2003.

9. Letter from J. A. Price (Dominion) to USNRC, "Millstone Power Station, Unit No. 3, Response to Request for Additional Information Regarding Exemption to Use a Low Tin Cladding (TAC No, MB9897)," Dominion Serial No. B19019, November 10, 2003.
10. Letter from V. Nerses (USNRC) to D. A. Christian (Dominion), "Millstone Power Station, Unit No. 3, Exemption from the Requirements of Title 10 of the Code of Federal Regulations (10 CFR) Part 50.44, 10 CFR 50.46, and 10 CFR Part 50, Appendix K (TAC No. M9897)," February 11, 2004.

Serial No.11-596 Docket No. 50-423 Proposed LAR - Optimized ZIRLO Attachment 1 Page 16 of 16

11. Letter from J. A. Gresham (Westinghouse) to USNRC (Document Control Desk),

"SER Compliance with WCAP-12610-P-A & CENPD-404-P-A, Addendum 1-A,

'Optimized ZIRLOTM, LTR-NRC-07-1, January 4, 2007.

12. Letter from J. A. Gresham (Westinghouse) to USNRC (Document Control Desk),

"SER Compliance with WCAP-12610-P-A & CENPD-404-P-A, Addendum 1-A,

'Optimized ZIRLOTM', LTR-NRC-07-58, November 6, 2007. (ML073130555)

13. Letter from J. A. Gresham (Westinghouse) to USNRC (Document Control Desk),

"SER Compliance with WCAP-12610-P-A & CENPD-404-P-A, Addendum 1-A,

'Optimized ZIRLOTM?, LTR-NRC-07-58, Rev. 1, February 5, 2008. (ML080390494)

14. Letter from J. A. Gresham (Westinghouse) to USNRC (Document Control Desk),

"SER Compliance of WCAP-1 2610-P-A & CENPD-404-P-A Addendum 1-A,

'Optimized ZIRLOT M ," LTR-NRC-08-60, December 30, 2008.

15. Letter from J. A. Gresham (Westinghouse) to USNRC (Document Control Desk),

"SER Compliance of WCAP-1 2610-P-A & CENPD-404-P-A Addendum 1-A,

'Optimized ZIRLOTM','" LTR-NRC-10-43, July 26, 2010.

Serial No.11-596 Docket No. 50-423 Proposed LAR - Optimized ZIRLO Attachment 2 Attachment 2 Marked-up Technical Specifications Pages DOMINION NUCLEAR CONNECTICUT, INC.

MILLSTONE POWER STATION UNIT 3

Serial No.11-596 Docket No. 50-423 Proposed LAR - Optimized ZIRLO Attachment 2 Page 1 of 3 Septzxmbef 17, 2402 DESIGN FEATURES 5.3 REACTOR CORE FUEL ASSEMBLIES 5.3.1 The core shal in 193 fuel assemblies. Each fuel assembly shall consist of 264 zircaloy-4 clad fuel rods with an initial composition of natural uranium dioxide or a maximum nominal enrichment of 5.0 weight percent U-235 as fuel material. Limited substitutions of zircaloy-4, ZIRL-O or stainless steel filler rods for fuel rods, in accordance with I ZIRLOG NRC-a ion of fuel rod configurations, may be used. Fuel assembly L I-co~nfigurations shall be limited to those fuel designs that have been analyzed with applicable NRC staff-approved codes and methods, and shown by test or cycle-specific reload analyses to comply with all fuel safety design bases. Each fuel rod shall have a nominal active fuel length of 144 inches. A limited number of lead test assemblies that have not completed representative testing may be placed in nonlimiting core regions.

CONTROL ROD ASSEMBLIES 5.3.2 The core shall contain 61 full-length control rod assemblies. The full-length control rod assemblies shall contain a nominal 142 inches of absorber material. The nominal values of absorber material shall be 95.3% hafnium and 4.5% natural zirconium or 80% silver, 15% indium, and 5% cadmium. All control rods shall be clad with stainless steel.

54 DELETED 5.5 DELETED MILLSTONE - UNIT 3 5-5 Amendment No. +2, 3-7, 8+ ,4 ,

Serial No.11-596 Docket No. 50-423 Proposed LAR - Optimized ZIRLO Attachment 2 Page 2 of 3 ADMINISTRATIVE CONTROLS CORE OPERATING LIMITS REPORT (Cont.)

6.9.1.6.b The analytical methods used to determine the core operating limits shall be those previously reviewed and approved by the NRC in:

I. WCAP-9272-P-A, "WESTINGHOUSE RELOAD SAFETY EVALUATION METHODOLOGY," (W Proprietary). (Methodology for Specifications 2.1.1. 1--Departure from Nucleate Boiling Ratio, 2.1.1.2--Peak Fuel Centerline Temperature, 3.1.1.3--Moderator Temperature Coefficient, 3.1.3.5--Shutdown Bank Insertion Limit, 3.1.3.6--Control Bank Insertion Limits, 3.2. 1 --AXIAL FLUX DIFFERENCE, 3.2.2--Heat Flux Hot Channel Factor, 3.2.3--Nuclear Enthalpy Rise Hot Channel Factor, 3.1.1.1.1, 3.1..1.2, 3.1.1.2 -- SHUTDOWN MARGIN,#

3.9. 1. 1-- Boron Concentration.)

2. T. M. Anderson to K. Kniel (Chief of Core Performance Branch, NRC), January 31, 1980--

Attachment:

Operation and Safety-Analysis Aspects of an Improved Load Follow Package.

3. NUREG-800, Standard Review Plan, U.S. Nuclear Regulatory Commission, Section 4.3, Nuclear Design, July 1981 Branch Technical Position CPB 4.3-1, Westinghouse Constant Axial Offset Control (CAOC), Revision 2, July 1981.
4. WCAP-10216-P-A-RIA, "RELAXATION OF CONSTANT AXIAL OFFSET CONTROL FQ SURVEILLANCE TECHNICAL SPECIFICATION,"

(W Proprietary). (Methodology for Specifications 3.2. 1--AXIAL FLUX DIFFERENCE [Relaxed Axial Offset Control] and 3.2.2--Heat Flux Hot Channel Factor [W(z) surveillance requirements for FQ Methodology].)

5. WCAP-12945-P-A, "CODE QUALIFICATION DOCUMENT FOR BEST ESTIMATE LOCA ANALYSIS," (_W_ Proprietary). (Methodology for Specification 3.2.2--Heat Flux Hot Channel Factor.)

/4

6. WCAP-16009-P-A, "REALISTIC LARGE-BREAK LOCA EVALUATION METHODOLOGY USING THE AUTOMATED STATISTICAL TREATMENT OF UNCERTAINTY METHOD (ASTRUM)," (3 Proprietary). (Methodology for Specification 3.2.2--Heat Flux Hot Channel Factor.)
7. WCAP- 11946, "Safety Evaluation Supporting a More Negative EOL Moderator Temperature Coefficient Technical Specification for the Millstone DoeljOe Nuclear Power Station Unit 3," (& Proprietary).
8. 1l0054-P-A, "WESTINGHOUSE SMALL BREAK ECCS EVALUATION MODE UPUSING THE NOTRUMP CODE," (W Proprietary). (Methodology for Specification 3.2.2 - Heat Flux Hot Channel Factor.)
9. WCAP-10079-P-A, "NOTRUMP - A NODAL TRANSIENT SMALL BREAK AND GENERAL NETWORK CODE," & Proprietary). (Methodology for Specification 3.2.2 - Heat Flux Hot Channel Factor.)
10. WCAP-12610, "VANTAGE+ Fuel Assembly Report," (W Proprietary).

(Methodology for Specification 3.2.2 - Heat Flux Hot Channel Factor.)

MILLSTONE - UNIT 3 6-20 Amendment No. -24,3,60, 69, &4-,

4-20, 4-70, 24-, 249, -36,4

Serial No.11-596 Docket No. 50-423 Proposed LAR - Optimized ZIRLO Attachment 2 Page 3 of 3 M~arch 14, 2007 ADMINISTRATIVE CONTROLS CORE OPERATING LIMITS REPORT (Cont.)

I1. Letter from V L. Rooney (USNRC) to J. F. Opeka, "Safety Evaluation for Topical Report, NUSCO-152, Addendum 4, 'Physics Methodology for PWR Reload Design,' TAC No. M91815," July 18, 1995.

12. Letter from E. J. Mroczka to the USNRC, "Proposed Changes to Technical Specifications, Cycle 4 Reload Submittal.- Boron Dilution Analysis," B13678, December 4, 1990.
13. Letter from D. H. Jaffe (USNRC) to E. J. Mroczka, "Issuance of Amendment (TAC No. 77924)," March 11, 1991.
14. Letter from M. H. Brothers to the USNRC, "Proposed Revision to Technical Specification, SHUTDOWN MARGIN Requirements and Shutdown Margin Monitor OPERABILITY for MODES 3, 4, and 5 (PTSCR 3-16-97), B 16447, May 9,1997.
15. Letter from J. W. Anderson (USNRC) to M. L. Bowling (NNECO), "Issuance of Amendment - Millstone Nuclear Power Station, Unit No. 3 (TAC No. M98699),"

October 21, 1998.

16. WCAP-8301, "LOCTA-IV Program: Loss-of-Coolant Transient Analysis."
17. WCAP-10054-P-A, Addendum 2, "Addendum to the Westinghouse Small Break ECCS Evaluation Model Using the NOTRUMP Code: Safety Injection into the Broken Loop and COSI Condensation Model."
18. WCAP-8745-P-A, "Design Bases for the Thermal Overpower AT and Thermal Overtemperature DT Trip Functions," (Westinghouse Proprietary Class 2).

(Methodology for Specifications 2. 1. and 2.2.1.)

19. WCAP-12610-P-A & CENPD-404-P-A, Addendum 1-A, "Optimized ZIRLOTM,,, (WA)Proprietary). (Methodology for Specification 3.2.2 - Heat Flux Hot Channel Factor.)

MILLSTONE - UNIT 3 6-20a Amendment No. 8+, G-7, 24-, 2-2-9 a-36,

Serial No.11-596 Docket No. 50-423 Proposed LAR - Optimized ZIRLO Attachment 3 Attachment 3 Exemption Request DOMINION NUCLEAR CONNECTICUT, INC.

MILLSTONE POWER STATION UNIT 3

Serial No.11-596 Docket No. 50-423 Proposed LAR - Optimized ZIRLO Attachment 3 Page 1 of 6 Request for Exemption from the Provisions of 10 CFR 50.46 and 10 CFR Part 50 Appendix K to Allow Use of Optimized ZIRLOTM in Core Reload Applications Table of Contents 1.0 P urpose ......................................................................................................... 2 2.0 B ackground ................................................................................................... 2 3.0 Technical Justification of Acceptability ..................................................... 3 4.0 Justification of Exem ption ........................................................................... 3 5.0 Special Circumstances Support the Issuance of an Exemption .............. 4 6.0 C onclusion .................................................................................................... 5 7.0 References .................................................................................................... 5

Serial No.11-596 Docket No. 50-423 Proposed LAR - Optimized ZIRLO Attachment 3 Page 2 of 6 1.0 Purpose Dominion Nuclear Connecticut, Inc. (DNC) requests an exemption from the provisions of 10 CFR 50.46, "Acceptance Criteria for Emergency Core Cooling Systems for Light-Water Nuclear Power Reactors," and Appendix K to 10 CFR Part 50, "ECCS Evaluation Models,"

to allow the use of Optimized ZIRLOTM fuel rod cladding in future core reload applications for Millstone Power Station, Unit 3 (MPS3). The regulation in 10 CFR 50.46 contains acceptance criteria for the emergency core cooling system (ECCS) for reactors that have fuel rods fabricated either with Zircaloy or ZIRLO cladding. Appendix K to 10 CFR Part 50, paragraph I.A.5, requires the Baker-Just equation to be used to predict the rates of energy release, hydrogen concentration, and cladding oxidation for the metal-water reaction. The Baker-Just equation assumed the use of a zirconium alloy different than Optimized ZIRLOTM material. Therefore, an exemption to 10 CFR 50.46 and 10 CFR Part 50, Appendix K is required to support the use of Optimized ZIRLOTM fuel rod cladding.

This exemption request relates solely to the specific cladding material specified in these regulations (i.e., fuel rods with Zircaloy or ZIRLO cladding).

2.0 Background

As the nuclear industry pursues longer operating cycles with increased fuel discharge burnup and fuel duty, the corrosion performance requirements for the nuclear fuel cladding become more demanding. Optimized ZIRLOTM was developed to meet these needs and provide a reduced corrosion rate while maintaining the benefits of mechanical strength and resistance to accelerated corrosion from abnormal chemistry conditions. In addition, fuel rod internal pressures (resulting from the increased fuel duty, use of integral fuel burnable absorbers, and corrosion/temperature feedback effects) have become more limiting with respect to fuel rod design criteria. Reducing the associated corrosion buildup, and thus minimizing temperature feedback effects, provides additional margin to the fuel rod internal pressure design criterion.

Starting in the spring of 2013, the reloads for MPS3 will contain fuel rods with Optimized ZIRLO cladding.

Technical Specifications (TS) changes for MPS3 are required to allow the use of Optimized ZIRLOTM fuel rod cladding for core reload applications. The request for these changes is provided as Attachment 1 to this submittal.

3.0 Technical Justification of Acceptability Westinghouse Electric Company, LLC (Westinghouse~topical report WCAP-1 2610-P-A &

CENPD-404-P-A, Addendum 1-A, "Optimized ZIRLOT "(Reference 1), provides the details and results of testing of Optimized ZIRLOTM material compared to standard ZIRLO as well as the material properties to be used in various models and methodologies when analyzing Optimized ZIRLOTM fuel rod cladding. The NRC Safety Evaluation (SE)

(Reference 2) for the topical report contains ten Conditions and Limitations. The first

Serial No.11-596 Docket No. 50-423 Proposed LAR - Optimized ZIRLO Attachment 3 Page 3 of 6 Condition requires an exemption from 10 CFR 50.46 and 10 CFR Part 50, Appendix K.

Westinghouse has provided the NRC with information related to test data and models (References 3 through 7) to address Conditions and Limitations 6 and 7. Condition and Limitation 9 does not apply because MPS3 is not licensed with LOCBART or STRIKIN-Il.

The remaining Conditions and Limitations are addressed in the MPS3 TS changes included in this submittal or will be addressed in evaluations required to support core reload activities. Since plant specific TS changes are required prior to utilizing Optimized ZIRLOTM fuel rod cladding, no new commitments are necessary to support NRC approval of this exemption request.

The normal core reload evaluations performed under 10 CFR 50.59 requirements will ensure that acceptance criteria are met for the insertion of assemblies with fuel rods clad with Optimized ZIRLOTM. These evaluations will use NRC approved methods and models.

4.0 Justification of Exemption 10 CFR 50.12, "Specific exemptions," states that the NRC may grant exemptions from the requirements of the regulations of this part of the Code of Federal Regulations provided three conditions are met. The three conditions are: 1) the exemption is authorized by law;

2) the exemption will not present an undue risk to the health and safety of the public; and
3) the exemption is consistent with the common defense and security.

The requested exemption to allow the use of Optimized ZIRLOTM fuel rod cladding material in addition to Zircaloy or ZIRLO material for core reload applications at MPS3 satisfies these criteria as described below.

1. This exemption is authorized by law.

As required by 10 CFR 50.12 (a)(1), this requested exemption is "authorized by law." The selection of a specified cladding material in 10 CFR 50.46 and implied in 10 CFR Part 50, Appendix K, was adopted at the discretion of the Commission consistent with its statutory authority. No statute required the NRC to adopt this specification. Additionally, the NRC has the authority under Section 50.12 to grant exemptions from the requirements of Part 50 upon showing proper justification.

Furthermore, by submitting this exemption request, MPS3 does not seek in exemption from the acceptance and analytical criteria of 10 CFR 50.46 and 10 CFR Part 50, Appendix K. Rather, the intent of the request is solely to allow the use of criteria set forth in these regulations for application to the Optimized ZIRLOTM fuel rod cladding material.

2. This exemption will not present an undue risk to public health and safety.

The reload evaluations will ensure that acceptance criteria are met for the insertion of assemblies with fuel rods clad with Optimized ZIRLOTM material. Fuel assemblies using Optimized ZIRLOTM fuel rod cladding will be evaluated using

Serial No.11-596 Docket No. 50-423 Proposed LAR - Optimized ZIRLO Attachment 3 Page 4 of 6 NRC approved analytical methods and plant specific models to address the changes in the cladding material properties. The reload safety analysis for MPS3 is supported by the applicable site specific TSs. Reload cores are required to be operated in accordance with the operating limits specified in the TSs. Thus, the granting of this exemption request will not pose an undue risk to public health and safety.

3. This exemption is consistent with common defense and security.

As noted above, this exemption request is only to allow the application of the aforementioned regulations to an improved fuel rod cladding material. All other requirements and acceptance criteria will be maintained. The special nuclear material in these assemblies is required to be handled and controlled in accordance with approved procedures. Use of full regions of Optimized ZIRLOTM fuel rod cladding in the MPS3 core will not affect plant operations and is consistent with common defense and security.

5.0 Special Circumstances Support the issuance of an Exemption 10 CFR 50.12(a)(2) states that the NRC will not consider granting an exemption to the regulations unless special circumstances are present. The requested exemption meets the special circumstances of 10 CFR 50.12(a)(2)(ii) which states that, "Application of the regulation in the particular circumstances would not serve the underlying purpose of the rule or is not necessary to achieve the underlying purpose of the rule." In this particular circumstance, application of the subject regulations is not necessary to achieve the underlying purpose of the rule.

10 CFR 50.46 identifies acceptance criteria for ECCS performance at nuclear power plants. Due to the similarities in the properties of the Optimized ZIRLOTM cladding material and standard cladding ZIRLO material, the current ECCS analysis approach remains applicable. Westinghouse will perform an evaluation of the MPS3 core using LOCA methods approved for the site to ensure that assemblies with Optimized ZIRLOTM fuel rod cladding material meet all LOCA safety criteria.

The intent of 10 CFR Part 50, Appendix K, paragraph I.A.5 is to apply an equation for rates of energy release, hydrogen generation, and cladding oxidation from a metal-water reaction that conservatively bounds all post-LOCA scenarios (i.e., the Baker-Just equation). Application of the Baker-Just equation has been demonstrated to be appropriate for the Optimized ZIRLOTM alloy. Due to the similarities in the composition of the Optimized ZIRLOTM and standard ZIRLO fuel rod cladding materials, the application of the Baker-Just equation will continue to conservatively bound all post-LOCA scenarios.

Serial No.11-596 Docket No. 50-423 Proposed LAR - Optimized ZIRLO Attachment 3 Page 5 of 6 6.0 Conclusion The acceptance criteria and requirements of 10 CFR 50.46 and 10 CFR Part 50, Appendix K are currently limited in applicability to the use of fuel rods with Zircaloy or ZIRLO cladding. 10 CFR 50.46 and 10 CFR Part 50, Appendix K do not apply to the proposed use of Optimized ZIRLOTM fuel rod cladding material since Optimized ZIRLOTM has a slightly different composition than the Zircaloy or ZIRLO material. With the approval of this exemption request, these regulations will be applied to Optimized ZIRLOTM fuel rod cladding, so Optimized ZIRLOTM may be used at MPS3.

In order to support the use of Optimized ZIRLOTM fuel rod cladding material, an exemption from the requirements of 10 CFR 50.46 and 10 CFR Part 50, Appendix K is requested. As required by 10 CFR 50.12, the requested exemption is authorized by law, does not present undue risk to public health and safety, and is consistent with common defense and security. Approval of this exemption request does not violate the underlying purpose of the rule. In addition, special circumstances do exist to justify the approval of an exemption from the subject requirements.

7.0 References

1. WCAP-12610-P-A & CENPD-404-P-A, Addendum 1-A, "Optimized ZIRLOTM, July 2006.
2. Letter from H. N. Berkow (USNRC) to J. A. Gresham (Westinghouse), "Final Safety Evaluation for Addendum 1 to Topical Report WCAP-12610-P-A & CENPD-404-P-A,

'Optimized ZIRLOTM' (TAC No. MB8041)," June 10, 2005 (ML051670395).

3. Letter from J. A. Gresham (Westinghouse) to USNRC (Document Control Desk),

"SER Compliance with WCAP-12610-P-A & CENPD-404-P-A, Addendum 1-A,

'Optimized ZIRLOTM'," LTR-NRC-07-1, January 4, 2007.

4. Letter from J. A. Gresham (Westinghouse) to USNRC (Document Control Desk),

"SER Compliance with WCAP-12610-P-A & CENPD-404-P-A, Addendum 1-A,

'Optimized ZIRLOTM'," LTR-NRC-07-58, November 6, 2007 (ML073130555).

5. Letter from J. A. Gresham (Westinghouse) to USNRC (Document Control Desk),

"SER Compliance with WCAP-12610-P-A & CENPD-404-P-A, Addendum 1-A,

'Optimized ZIRLOTM', LTR-NRC-07-58, Rev. 1, February 5, 2008 (ML080390494).

6. Letter from J. A. Gresham (Westinghouse) to USNRC (Document Control Desk),

"SER Compliance of WCAP-1 2610-P-A & CENPD-404-P-A Addendum 1-A,

'Optimized ZIRLOTM',"' LTR-NRC-08-60, December 30, 2008.

Serial No.11-596 Docket No. 50-423 Proposed LAR - Optimized ZIRLO Attachment 3 Page 6 of 6

7. Letter from J. A. Gresham (Westinghouse) to USNRC (Document Control Desk),

"SER Compliance of WCAP-1 2610-P-A & CENPD-404-P-A Addendum 1-A,

'Optimized ZIRLOTM,' "LTR-NRC-10-43, July 26, 2010.

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