Proprietary Information Withhold Under 10 CFR § 2.390 This letter is decontrolled when separated from Enclosure 2

Tennessee Valley Authority, 1101 Market Street, Chattanooga, 37402

CNL-20-014

September 23, 2020

10 CFR 50.90

U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555-0001

Sequoyah Nuclear Plant, Units 1 and 2 Renewed Facility Operating License Nos. DPR-77 and DPR-79 NRC Docket Nos. 50-327 and 50-328

Subject: Application to Modify the Nuclear Plant Units 1 and 2 Technical Specification to Allow for Transition to Westinghouse RFA-2 Fuel (SQN-TS-20-09)

References: 1. Summary of November 14, 2018, Meeting with Tennessee Valley Authority Regarding Presubmittal Licensing Actions - , Units 1 and 2 (ML18344A567)

2. Summary of January 31, 2019, Meeting with Tennessee Valley Authority Regarding Presubmittal Licensing Actions - Sequoyah Nuclear Plant, Units 1 and 2 (ML19038A469)

3. Summary of February 20, 2020, Public Meeting with Tennessee Valley Authority Regarding the Future Submittal of License Amendment Requests RE: Fuel Transition and Operation with One Control Rod Removed (ML20055C231)

4. NRC Letter to TVA, “Sequoyah Nuclear Plant, Unit 1 - Issuance of Exigent Amendment No. 348 to Operate One Cycle With One Control Rod Removed (EPID L-2019-LLA-0239),” dated November 21, 2019 (ML19319C831)

5. NRC Letter to TVA, “Sequoyah Nuclear Plant, Unit 2 - Issuance of Exigent Amendment No. 342 to Operate One Cycle with One Control Rod Removed (EPID L 2020 LLA 0078),” dated April 23, 2020 (ML20108F049)

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U.S. Nuclear Regulatory Commission CNL-20-014 Page 2 September 23, 2020

In accordance with the provisions of Title 10 of the Code of Federal Regulations (10 CFR) 50.90, “Application for amendment of license, construction permit, or early site permit,” Tennessee Valley Authority (TVA) is submitting a request for an amendment to Renewed Facility Operating License Nos. DPR-77 and DPR-79 for the Sequoyah Nuclear Plant (SQN) Units 1 and 2. This amendment is needed to facilitate transition to Westinghouse RFA-2 fuel with Optimized ZIRLOTM 1 cladding.

The proposed change revises these Technical Specifications (TSs):  TS 2.0 SAFETY LIMITS (SLs) TS 2.1.1, “Reactor Core SLs” Figure 2.1.1-1, “Reactor Core Safety Limit – Four Loops in Operation” is revised and relocated to the Core Operating Limits Report (COLR), Reactor Core Safety Limit 2.1.1.1 is revised to implement the methodology in the Westinghouse WRB-2M departure from nucleate boiling (DNB) correlation, and Reactor Core Safety Limit 2.1.1.2 is revised to implement the Westinghouse Performance Analysis and Design Model (PAD5) methodology for fuel melt temperature.  TS 3.1.4, “Rod Group Alignment Limits” is revised to be consistent with revised TS 3.2.1, “Heat Flux Hot Channel Factor (FQ(Z))” Surveillance Requirement numbering.  TS 3.1.7, “Rod Position Indication” is revised to implement BEACONTM 2 core power distribution measurement.  TS 3.2.1, “Heat Flux Hot Channel Factor (FQ(X,Y,Z))” is revised to reflect Standard Technical Specification (STS) 3.2.1 in NUREG-1431 and the methodology in WCAP-17661-P-A Revision 1, “Improved RAOC and CAOC FQ Surveillance Technical Specifications” with deviations to the Condition B Required Action Completion Times.  TS 3.2.2, “Nuclear Enthalpy Rise Hot Channel Factor F∆H(X,Y),” and 3.2.4, “Quadrant Power Tilt Ratio (QPTR),” are revised to implement Westinghouse STS format and content consistent with NUREG-1431, and TS 3.2.4 is revised to implement BEACON core power distribution measurement.  TS 3.3.1, “RTS Instrumentation” is revised to implement BEACON core power distribution measurement and relocation of OT∆T and OP∆T setpoint parameter values to the COLR consistent with TSTF-339-A, Rev. 2, “Relocate TS Parameters to COLR,” and WCAP-14483-A, “Generic Methodology for Expanded Core Operating Limits Report.”  TS 3.4.1, “RCS Pressure, Temperature, and Flow Departure from Nucleate Boiling (DNB) Limits” is revised to reflect a lower Thermal Design Flow rate and the relocation of parameter values to the COLR consistent with TSTF-339-A and WCAP-14483-A. ______

1Optimized ZIRLO is a trademark or registered trademarks of Westinghouse Electric Company LLC, its affiliates and/or its subsidiaries in the United States of America and may be registered in other countries throughout the world. All rights reserved. Unauthorized use is strictly prohibited. Other names may be trademarks of their respective owners. 2BEACON, FULL SPECTRUM and FSLOCA are trademarks or registered trademarks of Westinghouse Electric Company LLC, its affiliates and/or its subsidiaries in the United States of America and may be registered in other countries throughout the world. All rights reserved. Unauthorized use is strictly prohibited. Other names may be trademarks of their respective owners.

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U.S. Nuclear Regulatory Commission CNL-20-014 Page 3 September 23, 2020

 TS 4.2.1, “Fuel Assemblies” is revised to add Optimized ZIRLO as a fuel assembly cladding material in accordance with WCAP-12610-P-A & CENPD-404-P-A, Addendum 1-A, “Optimized ZIRLO.”  TS 4.2.1, “Fuel Assemblies,” is revised to delete the reference to Framatome lead test assemblies and the corresponding BAW-2328 topical report.  TS 4.2.2, “Control Rod Assemblies” is revised to reflect 52 rod cluster control assembly (RCCAs) for Units 1 and 2.  TS 5.6.3, “Core Operating Limits Report” is revised to reflect Westinghouse core safety analysis methodologies and to replace the loss-of-coolant accident (LOCA) analysis evaluation model references with the FULL SPECTRUM™3 Loss-of-Coolant Accident (FSLOCA™3) Evaluation Model analysis applicable to SQN Units 1 and 2.

In addition, the following Operating License (OL) License Conditions are proposed for replacement with new restrictions associated with the mixed or transition cores.  Unit 1 OL, License Condition 2(C)25  Unit 2 OL, License Condition 2(C)18

In Reference 1, TVA proposed an alternative approach for a fuel transition license amendment. NRC provided feedback on this approach via public meeting in Reference 2, noting specific concerns related to the fuel transition to be included for review for the staff to independently verify the fuel transition could be implemented in conformance with NRC requirements. Therefore, in addition to the TS and OL changes discussed above, the proposed change presents the following to address the staff’s feedback:  The core configurations for the transition based on the expected transition and equilibrium core designs being presented.  The operating limits for the RFA-2 fuel and the Framatome HTP fuel in the transition cores.  The use of the Westinghouse methods for core design and for determining core operating limits in the transition cores and subsequent equilibrium cores containing only RFA-2 fuel.  The safety analyses, specifically, that these analyses satisfy the applicable conditions and limitations associated with the employed methods and that these analyses meet applicable safety analysis and regulatory acceptance criteria.

Enclosure 1 provides a description of the proposed changes, technical evaluation of the proposed changes, regulatory evaluation, and a discussion of environmental considerations. Attachments 1 and 2 to the enclosure provide the existing TS pages marked-up to show the proposed changes for

______3 FULL SPECTRUM and FSLOCA are trademarks of Westinghouse Electric Company LLC

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U.S. Nuclear Regulatory Commission CNL-20-014 Page 4 September 23, 2020

SQN Unit 1 and Unit 2, respectively. Attachments 3 and 4 to the enclosure provide the SQN Unit 1 and Unit 2 TS pages retyped to show the proposed changes. Attachment 5 to the enclosure provides the existing SQN Unit 1 TS Bases pages marked-up to show the proposed changes. Only the Unit 1 TS Bases pages have been provided, as the Unit 2 changes will be nearly identical except for some editorial differences. Changes to the existing TS Bases are provided for information only and will be implemented under the TS Bases Control Program.

As discussed in References 4 and 5, both units have approved temporary Technical Specification changes to allow the RCCA in core location H-08 to be removed. As a result of the timing of the fuel transition, the request for permanent removal of the RCCA has been integrated into the attached amendment request.

Enclosure 1 also contains:  Attachment 6 – revised Core Operating Limits Report (COLR) Template for SQN Units 1 and 2 (For Information Only)  Attachment 7 – revised Technical Requirements Manual (TRM) (Mark-Ups) for SQN Unit 1 (For Information Only)  Attachment 8 – Compliance with Limitations and Conditions from NRC-Approved Newly Applied Topical Reports  Attachment 9 – Justification for Permanent Removal of SQN Units 1 and 2 RCCA H-08  Attachment 10 – Sequoyah Safety Analysis UFSAR Impact Summary for the WEC RFA-2 Fuel Transition

Enclosure 2 to this letter provides a summary of the SQN Units 1 and 2 LOCA Analysis with the FSLOCA Evaluation Methodology. This document contains information that Westinghouse Electric Company LLC considers to be proprietary in nature and subsequently, pursuant to Title 10 of the Code of Federal Regulations (10 CFR), Part 2.390, “Public inspections, exemptions, requests for withholding,” paragraph (a)(4), TVA requests that this proprietary information be withheld from public disclosure. Enclosure 3 contains a non-proprietary version of the summary of the SQN Units 1 and 2 LOCA Analysis with the FSLOCA Evaluation Methodology.

Enclosure 4 provides the Westinghouse Application for Withholding Proprietary Information from Public Disclosure CAW-20-5063 affidavit supporting this proprietary withholding request, signed by Westinghouse, the owner of the information. The affidavit sets forth the basis on which the information may be withheld from public disclosure by the Nuclear Regulatory Commission (“Commission”) and addresses with specificity the considerations listed in paragraph (b)(4) of Section 2.390 of the Commission's regulations. Accordingly, TVA requests that the information which is proprietary to Westinghouse be withheld from public disclosure in accordance with 10 CFR Section 2.390 of the Commission's regulations. Correspondence with respect to the copyright or proprietary aspects of the items listed above or the supporting Westinghouse affidavit should reference CAW-20-5063 and should be addressed to Camille T. Zozula, Manager,

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U.S. Nuclear Regulatory Commission CNL-20-014 Page 5 September 23, 2020

Regulatory Compliance & Corporate Licensing, Westinghouse Electric Company, 1000 Westinghouse Drive, Building 1, Cranberry Township, Pennsylvania 16066.

In addition, as the Westinghouse RFA-2 fuel will have Optimized ZIRLO cladding, an exemption request has been included for NRC approval in Enclosure 5.

TVA has determined that there are no significant hazards considerations associated with the proposed amendment and TS changes. The proposed amendment and TS changes qualify for a categorical exclusion from environmental review pursuant to the provisions of 10 CFR 51.22(c)(9). In accordance with 10 CFR 50.91(b)(1), TVA is sending a copy of this letter and attachments to the Division of Radiological Health – Tennessee State Department of Environment and Conservation.

As discussed in Reference 3, the technical evaluations, calculations and safety analyses for the transition to Westinghouse RFA-2 fuel have been completed and will be made available for regulatory audits to leverage the review efficiency as suggested by NRC in Reference 2.

TVA requests approval of the proposed license amendment within one year from the date of this submittal. The TS changes are to be implemented when the Westinghouse RFA-2 fuel is loaded for Cycle 26 in both SQN units. Approximate dates for implementation are November 1, 2022 for SQN Unit 1 and March 15, 2023 for SQN Unit 2.

There are no new regulatory commitments associated with this submittal. If you have any questions about this proposed change, please contact Gordon Williams, Senior Manager, Fleet Licensing (Acting) at (423) 751-2687.

I declare under penalty of perjury that the foregoing is true and correct. Executed on this 23rd day of September 2020.

Respectfully,

James Barstow Vice President, Nuclear Regulatory Affairs & Support Services

Enclosures cc: see Page 6

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U.S. Nuclear Regulatory Commission CNL-20-014 Page 6 September 23, 2020

Enclosure 1: Evaluation of the Transition to Westinghouse RFA-2 Fuel Enclosure 2: Application of Westinghouse FULL SPECTRUM LOCA Evaluation Model to the Sequoyah Nuclear Plant (Proprietary) FSLOCA Enclosure 3: Application of Westinghouse FULL SPECTRUM LOCA Evaluation Model to the Sequoyah Nuclear Plant (Non-Proprietary) FSLOCA Enclosure 4: Affidavit Enclosure 5: Exemption Request cc (Enclosures)

NRC Regional Administrator – Region II NRC Resident Inspector – Sequoyah Nuclear Plant NRC Project Manager – Sequoyah Nuclear Plant Director, Division of Radiological Health – Tennessee State Department of Environment and Conservation

Proprietary Information Withhold Under 10 CFR § 2.390 This letter is decontrolled when separated from Enclosure 2 Enclosure 1

Evaluation of the Transition to Westinghouse RFA-2 Fuel

Subject: Application to Modify the Sequoyah Nuclear Plant Units 1 and 2 Technical Specification to Allow for Transition to Westinghouse RFA-2 Fuel (SQN-TS-20-09)

CONTENTS

1.0 Summary Description ...... 1 2.0 Detailed Description ...... 2 2.1 Background ...... 2 2.2 Need for Proposed Changes ...... 3 2.3 Proposed Changes ...... 3 2.4 Condition Intended to Resolve ...... 6 3.0 TECHNICAL EVALUATION ...... 7 3.1 System Description ...... 7 3.1.1 Seismic/LOCA Impact on Fuel Assemblies ...... 8 3.1.2 Safety Analysis Impact Summary ...... 9 3.1.3 Source Terms ...... 9 3.1.4 Nuclear Core Design ...... 9 3.2 Technical Analysis ...... 27 3.2.1 TS 2.0 Safety Limits Changes ...... 27 3.2.2 TS 3.1 Reactivity Control Systems Changes ...... 30 3.2.3 TS 3.2 Power Distribution Limits Changes ...... 32 3.2.4 TS 3.3.1 Reactor Trip System (RTS) Instrumentation Changes ...... 39 3.2.5 TS 3.4.1 RCS Pressure, Temperature, and Flow Departure from Nucleate Boiling (DNB) Limits Changes ...... 41 3.2.6 TS 4.2.1 Fuel Assemblies Changes ...... 43 3.2.7 TS 4.2.2 Control Rod Assemblies Changes ...... 44 3.2.8 TS 5.6.3 Core Operating Limits Report Changes ...... 44 3.2.9 Operating License Conditions 2.C (25) and 2.C (18) Changes ...... 49 3.3 Conclusion ...... 49 4.0 REGULATORY EVALUATION ...... 50 4.1 Applicable Regulatory Requirements/Criteria ...... 50 4.1.1 Regulations ...... 50 4.1.2 General Design Criteria ...... 51 4.1.3 Regulatory Guidance and Miscellaneous References ...... 53 4.2 Precedent ...... 54 4.3 No Significant Hazards Consideration ...... 55

Enclosure 1

Evaluation of the Transition to Westinghouse RFA-2 Fuel

4.4 Conclusions ...... 60 5.0 ENVIRONMENTAL CONSIDERATION ...... 61 6.0 REFERENCES ...... 61

ATTACHMENTS 1. Proposed TS Changes Mark-Ups for SQN Unit 1 2. Proposed TS Changes Mark-Ups for SQN Unit 2 3. Proposed TS Changes (Final Typed) for SQN Unit 1 4. Proposed TS Changes (Final Typed) for SQN Unit 2 5. Revised TS Bases Page Changes (Mark-Ups) for SQN Unit 1 (For Information Only) 6. Revised Core Operating Limits Report (COLR) Template for Units 1 and 2 (For Information Only) 7. Revised Technical Requirements Manual (TRM) (Mark-Ups) for Units 1 and 2 (For Information Only) 8. Compliance with Limitations and Conditions from NRC-Approved Newly Applied Topical Reports 9. Justification for Permanent Removal of Units 1 and 2 RCCA H08 10. Sequoyah Safety Analysis UFSAR Impact Summary for the WEC RFA-2 Fuel Transition

Enclosure 1

Evaluation of the Transition to Westinghouse RFA-2 Fuel

1.0 SUMMARY DESCRIPTION

This evaluation supports a request to amend Renewed Facility Operating License No. DPR-77 for the Sequoyah Nuclear Plant (SQN) Unit 1, and Renewed Facility Operating License No. DPR-79 for the SQN Unit 2.

The proposed amendment revises the following SQN Units 1 and 2 Technical Specifications (TSs):

 TS 2.0 SAFETY LIMITS (SLs) TS 2.1.1, “Reactor Core SLs” Figure 2.1.1-1, “Reactor Core Safety Limit – Four Loops in Operation,” is revised and relocated to the Core Operating Limits Report (COLR), Reactor Core Safety Limit 2.1.1.1 is revised to implement the methodology in the Westinghouse WRB-2M departure from nucleate boiling (DNB) correlation, and Reactor Core Safety Limit 2.1.1.2 is revised to implement the Westinghouse Performance Analysis and Design Model (PAD5) methodology for fuel melt temperature.  TS 3.1.4, “Rod Group Alignment Limits,” is revised to be consistent with revised TS 3.2.1, “Heat Flux Hot Channel Factor (FQ(Z))” Surveillance Requirement numbering.  TS 3.1.7, “Rod Position Indication,” is revised to implement BEACONTM 4 core power distribution measurement.  TS 3.2.1, “Heat Flux Hot Channel Factor (FQ(XY,Z)),” is revised to reflect STS 3.2.1 in NUREG-1431 and the methodology in WCAP-17661-P-A Revision 1, “Improved RAOC and CAOC FQ Surveillance Technical Specifications” with deviations to the Condition B Required Action Completion Times.  TS 3.2.2, “F∆H(X,Y),” and 3.2.4, “Quadrant Power Tilt Ratio (QPTR),” are revised to implement Westinghouse Standard Technical Specification (STS) format and content consistent with NUREG-1431, and TS 3.2.4 is revised to implement BEACON core power distribution measurement.  TS 3.3.1, “RTS Instrumentation” is revised to implement BEACON core power distribution measurement and relocation of OT∆T and OP∆T setpoint parameter values to the COLR consistent with TSTF-339-A, Rev. 2, “Relocate TS Parameters to COLR,” and WCAP-14483-A, “Generic Methodology for Expanded Core Operating Limits Report.”  TS 3.4.1, “RCS Pressure, Temperature, and Flow Departure from Nucleate Boiling (DNB) Limits,” is revised to reflect a lower Thermal Design Flow rate and the relocation of parameter values to the COLR consistent with TSTF-339-A and WCAP-14483-A.  TS 4.2.1, “Fuel Assemblies” is revised to add Optimized ZIRLOTM 5 as a fuel assembly cladding material in accordance with WCAP-12610-P-A & CENPD-404-P-A, Addendum 1-A, “Optimized ZIRLO.”  TS 4.2.1, “Fuel Assemblies,” is revised to delete the reference to Framatome lead test assemblies and the corresponding BAW-2328 topical report.  TS 4.2.2, “Control Rod Assemblies” is revised to reflect 52 RCCAs for Units 1 and 2. ______

4BEACON, FULL SPECTRUM and FSLOCA are trademarks or registered trademarks of Westinghouse Electric Company LLC, its affiliates and/or its subsidiaries in the United States of America and may be registered in other countries throughout the world. All rights reserved. Unauthorized use is strictly prohibited. Other names may be trademarks of their respective owners. 5Optimized ZIRLO is a trademark or registered trademarks of Westinghouse Electric Company LLC, its affiliates and/or its subsidiaries in the United States of America and may be registered in other countries throughout the world. All rights reserved. Unauthorized use is strictly prohibited. Other names may be trademarks of their respective owners. CNL-20-014 E1 1 of 63 Enclosure 1

Evaluation of the Transition to Westinghouse RFA-2 Fuel x TS 4.2.2, “Control Rod Assemblies” is revised to reflect 52 RCCAs for Units 1 and 2. x TS 5.6.3, “Core Operating Limits Report” is revised to reflect Westinghouse core safety analysis methodologies and to replace the loss-of-coolant accident (LOCA) analysis evaluation model references with the FULL SPECTRUM™6 Loss-of-Coolant Accident (FSLOCA™6) Evaluation Model analysis applicable to SQN Units 1 and 2.

The proposede also chan revisesg the S QN Units 1 and 2 Operating License (OL) to replace OL condition 2.C(25) and 2.C(18), respectively. These Conditions will no longer be applicable with Westinghouse fuel in the core. However, during the transition or mixed cores, new penalties will be established, as discussed in Section 3.2.8 below.

The proposed changes to the SQN Units 1 and 2 TSs are consistent with NUREG-1431, “Standard Technical Specifications Westinghouse Plants,” Revision 4.

Attachments 1 and 2 to this Enclosure provide the TS pages marked-up to show the proposed changes for SQN Unit 1 and Unit 2, respectively. Attachments 3 and 4 to the enclosure provide the SQN Unit 1 and Unit 2 TS pages retyped to show the proposed changes.

Attachment 5 to the enclosure provides the existing SQN Unit 1 TS Basese pag s marked-up to show the proposed changes. Only the Unit 1 TS Bases pages have been provided, as the Unit 2 changes will be nearly identical except for some editorial differences. Changes to the existing TS Bases are provided for information only and will be implemented under the Technical Specification Bases Control Program.

The enclosure also includes: x Attachment 6 – revised Core Operating Limits Report (COLR) Template for SQN Units 1 and 2 (For Information Only) x Attachment 7 – revised Technical Requirements Manual (TRM) (Mark-Ups) for SQN Unit 1 (For Information Only) x Attachment 8 – Compliance with Limitations and Conditions from NRC-Approved Newly Applied Topical Reports x Attachment 9 – Justification for Permanent Removal of SQN Units 1 and 2 RCCA H08 x Attachment 10 – Sequoyah Safety Analysis UFSAR Impact Summary for the WEC RFA-2 Fuel Transition

2.0 DETAILED DESCRIPTION

2.1 Background

Tennessee Valley Authority (TVA) plans to transition Sequoyah Units 1 and 2 from Framatome-supplied high thermal performance (HTP) fuel to Westinghouse 17x17 Robust Fuel Assembly-2 (RFA-2), commencing with Unit 1 Cycle 26 and Unit 2 Cycle 26. The 17x17 RFA-2 fuel for SQN Units 1 and 2 includes the following features: x Integral fuel burnable absorbers (IFBAs) x Robust protective grid (RPG) ______6 FULL SPECTRUM and FSLOCA are trademarks of Westinghouse Electric Company LLC CNL-20-014 E1 2 of 63 Enclosure 1

Evaluation of the Transition to Westinghouse RFA-2 Fuel x Standardized debris filter bottom nozzle (SDFBN) x High-burnup bottom grid x Debris mitigating long fuel rod bottom end plugs x Wet annular burnable absorbers (WABA) x Removable top nozzle (RTN) x Three ZIRLO intermediate flow mixer (IFM) grids x Six ZIRLO RFA-2 structural mid-grids x Reduced rod bow (RRB) INCONEL® top grid x Optimized ZIRLO high-performance fuel cladding with a coated cladding feature x Thicker-walled guide thimble and instrumentation tubes to improve fuel assembly stiffness and to address incomplete rod insertion (IRI) considerations.

The 17x17 RFA-2 fuel is similar to the fuel in use at North Anna Units 1 and 2. Except for Optimized ZIRLO cladding, the 17x17 RFA-2 fuel is similar to the fuel in several other plants, including Millstone 3, Seabrook, Beaver Valley, and Watts Bar. An exemption request for the use of Optimized ZIRLO cladding at Sequoyah is included with this amendment request as Enclosure 5.

The structural mid-grid design used in the RFA-2 fuel assembly is a modification of the low-pressure-drop mid-grid design that was accepted by the NRC for use in the VANTAGE-5-Hybrid (V5H) fuel assembly design (Reference 1). The RFA-2 mid-grid design was the culmination of several changes evaluated by means of the NRC-approved Fuel Criteria Evaluation Process (FCEP) (Reference 2). By complying with the requirements of the FCEP, it has been demonstrated that the mid-grid design meets all design criteria of the tested mid-grids that form the basis of the WRB-2M correlation database and that the WRB-2M correlation applies to the new RFA-2 mid-grid as well as the IFM grid (References 3, 4, and 5).

The proposed transition to Westinghouse 17x17 RFA-2 fuel for SQN Units 1 and 2 will require changes to the TS and OL as discussed below.

2.2 Need for Proposed Changes

The proposed TS and OL changes and the exemption request are needed for the SQN Unit 1 and 2 transition to Westinghouse RFA-2 fuel with Optimized ZIRLO cladding, which includes the Westinghouse transition core methodology, Westinghouse core safety analysis methodology, the FSLOCA Evaluation Model, the BEACON core monitoring capability, and the PAD5 fuel performance analysis and design model. This license amendment request (LAR) also includes a request for permanent removal of a rod cluster control assembly (RCCA) at core location H-08 for both units.

2.3 Proposed Changes

The proposed change revises the SQN Units 1 and 2 TS and OL as follows.

TS 2.1.1 Reactor Core Safety Limits (SL) Changes

The proposed change would revise TS 2.1.1, “Reactor Core SLs” Figure 2.1.1-1, “Reactor Core Safety Limit – Four Loops in Operation” which specifies the acceptable operation

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Evaluation of the Transition to Westinghouse RFA-2 Fuel

domain with consideration given to the fraction of Rated Thermal Power, Reactor Coolant System (RCS) highest loop average temperature, and pressurizer pressure. The Reactor Core Safety Limit Figure would be revised based upon the application of Nuclear Regulatory Commission (NRC) approved WCAP-11397-P-A, “Revised Thermal Design Procedure” (Reference 6) evaluation methodology. The proposed change to TS 2.1.1 would also relocate the revised figure to the COLR consistent with NRC-approved TSTF-339-A, Rev. 2, “Relocate TS Parameters to COLR” (Reference 7), and NRC-approved WCAP-14483-A, “Generic Methodology for Expanded Core Operating Limits Report” (Reference 8). Relocating the Reactor Core Safety Limit Figure from TS 2.1.1 to the COLR will also be consistent with TS 2.1.1 in NUREG-1431, “Standard Technical Specifications Westinghouse Plants” (Reference 9).

The proposed change would revise Reactor Core Safety Limit 2.1.1.1 based upon the application of NRC approved WCAP-15025-P-A, “Modified WRB-2 Correlation, WRB-2M, for Predicting Critical Heat Flux in 17x17 Rod Bundles with Modified LPD Mixing Vane Grids” (Reference 10) evaluation methodology. The change would replace the three Framatome departure from nucleate boiling (DNB) correlation values with a single WRB-2M DNB correlation value.

The proposed change would revise Reactor Core Safety Limit 2.1.1.2 based upon the application of NRC approved WCAP-17642-P-A, Revision 1, “Westinghouse Performance Analysis and Design Model (PAD5)” (Reference 11) evaluation methodology. The change would replace the peak fuel centerline temperature derived from Framatome methodology with the burnup-dependent Westinghouse PAD5 peak fuel centerline temperature limit.

TS 3.1 REACTIVITY CONTROL SYSTEMS Changes

The proposed change would revise TS 3.1.4, “Rod Group Alignment Limits,” Required Action B.2.4 to add SR 3.2.1.2, consistent with changes to TS 3.2.1, “Heat Flux Hot Channel Factor (FQ(X,Y,Z)).” Surveillance Requirements (SRs) 3.2.1.1 and 3.2.1.2 would be revised consistent with TS 3.2.1, “Heat Flux Hot Channel Factor (FQ(Z)),” from NRC-approved WCAP-17661-P-A Revision 1, “Improved RAOC and CAOC FQ Surveillance Technical Specifications” (Reference 12) which incorporated improvements to the relaxed axial offset control (RAOC) version of TS 3.2.1B from NUREG-1431, Revision 4 (Reference 9). Steady state and transient FQ surveillances are also consistent with the RAOC version of TS 3.2.1 in Reference 9.

The proposed change would revise TS 3.1.7, “Rod Position Indication,” Required Actions A.1, A.2.1, B.3, and C.1 to implement BEACON core power distribution measurement consistent with NRC-approved WCAP-12472-P-A, “BEACON Core Monitoring and Operations Support System” (Reference 13), and WCAP-12472-P-A, Addendum 4-A, Revision 0, “BEACON Core Monitoring and Operation Support System, Addendum 4” (Reference 14), and replace the discussion of flux maps obtained solely using the movable incore detectors with more generic terminology (i.e., “core power distribution measurement information”).

TS 3.2 POWER DISTRIBUTION LIMITS Changes

The proposed change would revise TS 3.2.1, “Heat Flux Hot Channel Factor (FQ(X,Y,Z)),” based upon STS 3.2.1, “Heat Flux Hot Channel Factor (FQ(Z)),” from Reference 9 as revised by NRC-approved WCAP-17661-P-A, Appendix A for RAOC plants, with deviations based on

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Evaluation of the Transition to Westinghouse RFA-2 Fuel

References 30 and 31. The change would also implement BEACON core power distribution measurement consistent with WCAP-12472-P-A,” and WCAP-12472-P-A, Addendum 4-A.

The proposed change would revise TS 3.2.2, “Nuclear Enthalpy Rise Hot Channel Factor Fǻ+(X,Y),” to be consistent with STS 3.2.2, “Nuclear Enthalpy Rise Hot Channel Factor N (F 'H)” in Reference 9.

The proposed change would revise TS 3.2.4, “Quadrant Power Tilt Ratio (QPTR),” Required Actions A.3 and A.6 to be consistent with the Surveillance Requirement numbering in revised TS 3.2.1 and revised TS 3.2.2. SR 3.2.4.2 would be changed to implement BEACON core power distribution measurement consistent with WCAP-12472-P-A and WCAP-12472-P-A, Addendum 4-A, and replace the discussion of flux maps obtained solely using the movable incore detectors with more generic terminology (i.e., “core power distribution measurement information”).

TS 3.3.1 RTS Instrumentation Changes

The proposed change would revise TS 3.3.1, “RTS Instrumentation,” SRs 3.3.1.3 and 3.3.1.6 to implement BEACON core power distribution measurement consistent with NRC-approved WCAP-12472-P-A and WCAP-12472-P-A, Addendum 4-A. Table 3.3.1-1 Note 1, ³2YHUWHPSHUDWXUHǻ7´ZRXOGEHUHYLVHGWRLQFUHDVHWKH.2 DQG.3 FRHIILFLHQWVLQWKH27ǻ7 reactor trip function .2 ZLOOEHLQFUHDVHGIURP•q)WR•q).3 will be increased from 0.00055/psig to 0.0008/psig) using NRC-approved WCAP-8745-P-A, “Design Bases for the 7KHUPDO2YHUSRZHU¨7DQG7KHUPDO2YHUWHPSHUDWXUH¨77ULS)XQFWLRQV´(Reference 15) evaluation methodology.

Table 3.3.1-1RWHVDQGZRXOGEHUHYLVHGWRUHORFDWH27ǻ7DQG23¨7SDUDPHWHUYDOXHV (nominal RCS average temperature and operating pressure at full power, LaPlace transform FRQVWDQWV.1 WKURXJK.6DQG3URFHVV3URWHFWLRQ6\VWHPFDUGGHOD\WLPHVIJ1 WKURXJKIJ5) to the COLR consistent with NRC approved TSTF-339-A, Rev. 2, and WCAP-14483-A.

TS 3.4.1 RCS Pressure, Temperature, and Flow Departure from Nucleate Boiling (DNB) Limits Changes

The proposed change would revise TS 3.4.1, “RCS Pressure, Temperature, and Flow Departure from Nucleate Boiling (DNB) Limits,” to remove the specified Minimum Measured Flow rate of 378,400 gpm and insert the revised Thermal Design Flow rate of 360,000 gpm. The proposed change would relocate the current parameter values from LCO 3.4.1 and SRs 3.4.1.1 – 3.4.1.4 to the COLR. The LCO 3.4.1, SR 3.4.1.3, and SR 3.4.1.4 RCS total flow rate is revised from ³•JSP´WRWKH7KHUPDO'HVLJQ)ORZ 7') YDOXHRI³•JSP” in conjunction with “and greater than or equal to the limit specified in the COLR.” This change is consistent with TSTF-339-A, Rev. 2, WCAP-14483-A, and NUREG-1431.

TS 4.2.1 Fuel Assemblies Changes

The proposed change would revise TS 4.2.1, “Fuel Assemblies” to add Optimized ZIRLO as a fuel assembly cladding material in accordance with NRC-approved WCAP-12610-P-A & CENPD-404-P-A, Addendum 1-A, “Optimized ZIRLO” (Reference 16). The Optimized ZIRLO clad material contains a lower tin content than ZIRLO cladding, thereby reducing corrosion. An

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Evaluation of the Transition to Westinghouse RFA-2 Fuel exemption to 10 CFR 50.46 is also requested in Enclosure 5 consistent with WCAP-12610-P-A & CENPD-404-P-A, Addendum 1-A. The proposed change would also delete the discussion of Framatome lead test assemblies and report BAW-2328 consistent with the proposed implementation of Westinghouse core safety analysis methodology.

TS 4.2.2 Control Rod Assemblies

The proposed change would revise TS 4.2.2, “Control Rod Assemblies” to require 52 rod cluster control assemblies (RCCAs) with no full-length control rod assembly in core location H-08 for Units 1 and 2. This change would also remove any cycle-specific restraints associated with this configuration. This proposed change is discussed in Attachment 9 to this Enclosure.

TS 5.6.3 Core Operating Limits Report Changes

The proposed change would revise TS 5.6.3.a, “Core Operating Limits Report,” to add additional core operating limits for Limiting Conditions for Operation (LCOs) 2.1.1, 3.1.4, 3.1.8, 3.3.1, and 3.4.1. In addition, the existing LCO titles will be revised consistent with the proposed TS changes discussed above. TS 5.6.3.b is revised to change analytical methods used to determine the core operating limits from Framatome methods to Westinghouse core safety analysis methodology references. This includes the application of the FSLOCA Evaluation Methodology (Reference 17) to evaluate the peak cladding temperatures for SQN Units 1 and 2 large-break and small-break LOCAs (LBLOCA and SBLOCA).

Renewed License No. DPR-77 and DPR-79

The proposed change also revises the SQN Units 1 and 2 Operating License (OL) to replace OL condition 2.C (25) and 2.C (18) respectively, as a result of the implementation of Westinghouse core safety analysis methodology. Specifically, the following license condition is proposed. When the Framatome HTP fuel assemblies are co-resident with the Westinghouse RFA-2 fuel assemblies the: N x HTP fuel assemblies F ǻ+ shall be maintained less than 1.61. x RFA-2 fuel assemblies the DNBR limit shall be reduced by: — 0.25% for the WRB-2M critical heat flux correlation — 0.50% for the ABB-NV critical heat flux correlation

2.4 Condition Intended to Resolve

The proposed change will allow TVA to use Westinghouse core safety analysis methodologies as part of a transition from Framatome-supplied HTP fuel to Westinghouse 17x17 RFA-2 fuel with Optimized ZIRLO cladding. This includes the use the FSLOCA Evaluation Model to evaluate the peak cladding temperatures for LBLOCAs and SBLOCAs for SQN Units 1 and 2. The proposed change will allow TVA to operate with 52 RCCAs and no full-length control rod assembly in core location H-08 for Units 1 and 2 for the fuel transition and subsequent cycles.

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Evaluation of the Transition to Westinghouse RFA-2 Fuel

3.0 TECHNICAL EVALUATION

3.1 System Description

Beginning in Cycle 9, both SQN units were reloaded with Mark-BW fuel supplied by Framatome. Beginning with Cycle 19 for Unit 2 and Cycle 20 for Unit 1, each SQN unit was loaded with Advanced W17 high thermal performance (HTP) fuel supplied by AREVA NP, Inc. (Framatome). The Advanced W17 HTP fuel assembly consists of 264 fuel rods, 24 guide tubes and one instrument tube in a 17x17 square array. The guide tubes are annealed Zircaloy-4 and provide guidance for control rod insertion. The fuel assembly contains 7 Zircaloy-4 spacer grid assemblies including the uppermost grid and 1 nickel alloy 718 lowermost spacer grid assembly. The Advanced W17 HTP fuel assembly also includes 3 Zircaloy-4 intermediate flow mixing spacer grid assemblies. The bottom nozzle is a proven debris resistant design.

The basic design parameters of the Framatome Mark-BW and Advanced W17 HTP fuel assemblies are comparable to those of the Westinghouse Standard and Vantage 5H 17x17 fuel assemblies. The Mark-BW and Advanced W17 HTP fuel assemblies incorporate proven design features while maintaining compatibility with the Westinghouse reactor internals and fuel assemblies.

TVA plans to transition SQN Units 1 and 2 from Framatome-supplied HTP fuel to Westinghouse 17x17 Robust Fuel Assembly-2 (RFA-2), commencing with Unit 1 Cycle 26 and Unit 2 Cycle 26. The results of evaluations and analyses performed to confirm the acceptable transition to Westinghouse 17x17 RFA-2 fuel for SQN Units 1 and 2 are provided in this enclosure and supporting attachments.

Based on a comparison between the 17x17 V5H and RFA-2 designs, it was determined that the RFA-2 design is compatible with the HTP design. This was determined based on the compatibility of the RFA-2 fuel with the V5H fuel, explicit analysis, and the previous experience of mixed cores of V5H and Mark-BW fuel, and the ability for Sequoyah to adequately transition from Framatome Mark-BW fuel to HTP fuel. The changes between the V5H and RFA-2 fuel do not impact the compatibility of the RFA-2 fuel with the HTP fuel. The 17x17 RFA-2 fuel assembly is concluded to be mechanically and hydraulically compatible with the Framatome 17x17 HTP fuel assembly in full or transition cores since the Framatome 17x17 Mark-BW fuel assembly was once mixed with the 17x17 V5H design.

Westinghouse has established and obtained NRC approval for the design bases for several PWR fuel system designs (e.g., WCAP-9500-A, “Reference Core Report – 17 x 17 Optimized Fuel Assembly,” May 1982, WCAP 10444-P-A, “Westinghouse Reference Core Report – VANTAGE 5 Fuel Assembly,” September 1985, and WCAP-10125-P-A, “Extended Burnup Evaluation of Westinghouse Fuel,” December 1985). These design bases, or Specified Acceptable Fuel Design Limits (SAFDLs), and their respective evaluations comply with the “Acceptance Criteria” of SRP 4.2, “Fuel System Design,” and as such provide assurance that the fuel system is mechanically designed to perform safely. The plant specific requirements outlined in the NRC’s Safety Evaluation Reports (SER) for WCAP-9500-A and WCAP-10444-P-A will be adhered to in applying the Fuel Criteria Evaluation Process (FCEP – as described in WCAP-12488-A) to plant specific applications.

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Evaluation of the Transition to Westinghouse RFA-2 Fuel

The NRC-approved generic design criteria used to assess the performance of the RFA-2 fuel assemblies were developed to satisfy certain objectives as described in Reference 2 (WCAP-12488-A, “Westinghouse Fuel Criteria Evaluation Process,” October 1994). These objectives are used for designing fuel assemblies to provide the following assurances. x The fuel assembly (system) shall not fail as a result of normal operation and anticipated operational occurrences. The fuel assembly (system) dimensions shall be designed to remain within operational tolerances and the functional capabilities of the fuels shall be established to either meet or exceed those assumed in the safety analysis. x Fuel assembly (system) damage shall never prevent control rod insertion when it is required. x The number of fuel rod failures shall be conservatively estimated for postulated accidents. x Fuel coolability shall always be maintained. x The mechanical design of fuel assemblies shall be compatible with co-resident fuel and the reactor core internals.

The generic criteria are applied to the fuel rod and fuel assembly designs.

3.1.1 Seismic/LOCA Impact on Fuel Assemblies

The evaluation of the 17x17 RFA-2 fuel and Framatome high thermal performance (HTP) fuel assembly structural integrity in both mixed transition cores and full 17x17 RFA-2 core was performed with the established method focusing on the Beginning-of-Life (BOL) condition, as presented in WCAP-12610-P-A. Additionally, a fuel assembly analysis to address the RFA-2 fuel at the End-of-Life (EOL) condition has also been performed according to PWROG 16043-P-A, Rev. 2. The seismic analysis considered the safe shutdown earthquake (SSE) and operating basis earthquake (OBE) conditions. The LOCA analysis considered two different pipe break situations: accumulator (ACC) line break and pressurizer (PZR) surge line break. The seismic/LOCA analysis results were obtained using the time history numerical integration technique. The maximum grid impact forces obtained from both seismic and LOCA transient cores were combined using the square root sum of the squares (SRSS) method. The maximum grid impact forces were compared to the allowable grid crush strength.

The detailed site-specific seismic and LOCA fuel assembly analyses have been performed in accordance with NRC-approved methodologies: WCAP 12610-P-A (Reference 32), WCAP 12488-A (Reference 2), and WCAP-9401 (Reference 18). The standard BOL analysis was supplemented by fuel assembly seismic/LOCA analysis to address RFA-2 fuel at the EOL condition in both full core (RFA-2 fuel only) and co-resident (with Framatome fuel) cores using methodology approved by the NRC in PWROG-16043-P-A (Reference 19).

The analysis predicted no permanent grid deformation (grid crush) to occur in both homogeneous core and mixed cores under combined seismic and LOCA loadings. Because there was no thimble tube damage observed during the grid crush testing and the stress analysis shows that no fragmentation occurs for the fuel rods under the combined seismic and LOCA loads, it is concluded that the RCCA insertability is maintained and coolable geometry is maintained.

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Evaluation of the Transition to Westinghouse RFA-2 Fuel

An additional seismic and LOCA analysis was performed for a mixed core of HTP and RFA-2 fuel per the Framatome method of evaluation described in Reference 29. This analysis determines the impact loads on the HTP fuel in the mixed core and demonstrates that coolable geometry, control rod insertability, and fuel rod integrity are maintained for the HTP fuel.

3.1.2 Safety Analysis Impact Summary

As expected, the majority of the Updated Final Safety Analysis Report (UFSAR) safety analyses are revised to reflect the inputs and results from applying the Westinghouse methods and codes used to support the RFA-2 fuel, in addition to applying the FSLOCA and PAD5 methods. Attachment 10 (Sequoyah Safety Analysis UFSAR Impact Summary for the WEC RFA-2 Fuel Transition) summarizes the impact to the UFSAR safety analysis.

3.1.3 Source Terms

To address the transition to Westinghouse fuel, an assessment of the design basis source term (core activity inventory) for SQN Units 1 and 2 has been performed. The assessment consisted of comparing the current analysis of record (AOR) source key term input parameters to corresponding key input parameters for the representative transition and equilibrium fuel cycles associated with the reload transition.

The core loading parameters (core thermal power level, Uranium mass, cycle average burnup, Uranium-235 fuel enrichment) of the representative reload transition cycles were compared to the AOR core loading parameters. The AOR core loading parameters are bounding for all inputs based on conservatisms incorporated into the AOR, such as core thermal power which is directly proportional to the nuclide-specific activities.

It is concluded that the AOR core activity inventory remains applicable for the transition to Westinghouse fuel. This is due mainly to the similar and/or conservative input parameters applied to the AOR calculations.

3.1.4 Nuclear Core Design

Representative core designs were developed for the first two transition cycles that include Framatome fuel. If future designs desire to utilize HTP fuel, the requirements will be similar (if not identical) to the requirements during the first and second transition, which can be dealt with on a case by case basis. An equilibrium cycle design with only Westinghouse fuel was used to approximate subsequent reloads. Note that the core designs utilized are not intended to represent limiting designs, but were instead developed with the intent to determine if sufficient margin exists between typical parameter values and the corresponding safety analysis limits to allow flexibility in designing future cores. The margins for the Sequoyah core designs were compared to the values for recent Watts Bar reload cycles to evaluate the adequacy of margins between typical safety parameter values and the corresponding limits. As mentioned previously, cycle-specific calculations will confirm that the actual values are within the safety analysis limits.

Additional core designs were developed, apart from those already mentioned, for use in the FSLOCA methodology limit setting. These cores exhibit unrealistically high peaking factors which are intended to bound future reload peaking factors. These core designs are fully

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Evaluation of the Transition to Westinghouse RFA-2 Fuel representative of the range of core characteristics expected during and after the fuel transition from Framatome HTP fuel to Westinghouse RFA-2 fuel.

Further, two transition core designs in addition to two equilibrium cycles were developed as representative core designs to move Sequoyah from Framatome HTP fuel to Westinghouse RFA-2 fuel. The purpose of the loading patterns is to determine acceptability of core safety parameters with representative designs. The loading patterns were developed based on typical cycle energy requirements with current operating parameters for power, flow, and temperatures. The loading patterns are representative of both Sequoyah Units 1 and 2.

The transition cycles contain both Framatome HTP and Westinghouse RFA-2 fuel. The first transition cycle feeds 85 assemblies of Westinghouse RFA-2 fuel with both once and twice burned Framatome HTP fuel. A higher than usual feed batch is utilized to maximize the population of Westinghouse RFA-2 fuel in the first transition core. The second transition cycle includes feed and once burned Westinghouse RFA-2 fuel and twice burned Framatome HTP fuel. The two equilibrium cycles are representative loading patterns once the entire core contains Westinghouse RFA-2 fuel.

Figures 1 through 4 depict the representative loading patterns that were utilized for the reload transition safety analysis. Figures 5 through 8 show cycle characteristics of critical boron, axial RIIVHW)4DQG)ǻ+UHVSHFWLYHO\. Figures 9 through 16 show the beginning of cycle and end of cycle power and burnup distributions for each loading pattern.

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Evaluation of the Transition to Westinghouse RFA-2 Fuel

Figure 1: Representative First Sequoyah Transition Loading Pattern

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Evaluation of the Transition to Westinghouse RFA-2 Fuel

Figure 2: Representative Second Sequoyah Transition Loading Pattern

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Evaluation of the Transition to Westinghouse RFA-2 Fuel

Figure 3: Representative 77 Feed Sequoyah Equilibrium Loading Pattern

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Evaluation of the Transition to Westinghouse RFA-2 Fuel

Figure 4: Representative 76 Feed Sequoyah Equilibrium Loading Pattern

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Evaluation of the Transition to Westinghouse RFA-2 Fuel

1400

1200

1000

800 Equilibrium 2 Equilibrium 1 600 Transition 2

Critical Boron (ppm) Boron Critical Transition 1 400

200

0 0 2000 4000 6000 8000 10000 12000 14000 16000 18000 20000 22000 Burnup (MWD/MTU)

Figure 5: Critical Boron Concentrations for Transition and Equilibrium Cycles

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Evaluation of the Transition to Westinghouse RFA-2 Fuel

12

10

8

6 Equilibrium 2 4 Equilibrium 1 Transition 2 2 Transition 1 HFP Axial OFfset (%)

0 0 2000 4000 6000 8000 10000 12000 14000 16000 18000 20000 22000

-2

-4 Burnup (MWD/MTU)

Figure 6: HFP Axial Offset Comparisons for Transition and Equilibrium Cycles

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Evaluation of the Transition to Westinghouse RFA-2 Fuel

1.8

1.75

1.7 Equilibrium 2

FQ Equilibrium 1 1.65 Transition 2 Transition 1

1.6

1.55 0 2000 4000 6000 8000 10000 12000 14000 16000 18000 20000 22000 Burnup (MWD/MTU)

Figure 7: FQ Comparisons for Transition and Equilibrium Cycles

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Evaluation of the Transition to Westinghouse RFA-2 Fuel

1.48

1.46

1.44

1.42 Equilibrium 2 H ǻ

F Equilibrium 1 1.4 Transition 2 Transition 1 1.38

1.36

1.34 0 2000 4000 6000 8000 10000 12000 14000 16000 18000 20000 22000 Burnup (MWD/MTU)

)LJXUH)ǻ+&RPSDULVRQVIRU7UDQVLWLRQDQG(TXLOLEULXP&\FOHV

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Evaluation of the Transition to Westinghouse RFA-2 Fuel

H G F E D C B A

TR1 P1 TR1 P1 TR1 P1 TR1 P2 1.297 1.172 1.271 1.234 1.344 1.122 1.067 0.472 8 1.385 1.239 1.395 1.309 1.453 1.214 1.264 0.736 0 21464 0 21404 0 22499 0 31839 P1 TR1 P1 P1 P1 TR1 TR1 P2 1.171 1.346 1.181 1.229 1.228 1.138 1.06 0.44 9 1.239 1.415 1.257 1.302 1.311 1.257 1.242 0.72 21486 0 22845 21451 19559 0 0 33987 TR1 P1 TR1 P1 TR1 P1 TR1 P2 1.269 1.179 1.313 1.262 1.233 1.088 1.09 0.407 10 1.393 1.256 1.402 1.341 1.397 1.16 1.305 0.712 0 22835 0 19292 0 22761 0 35861 P1 P1 P1 TR1 P1 TR1 TR1 P2 1.231 1.223 1.257 1.275 1.11 1.143 1.013 0.313 11 1.306 1.293 1.336 1.398 1.197 1.266 1.265 0.641 21400 21615 19427 0 20886 0 0 41560 TR1 P1 TR1 P1 P1 TR1 P1 1.339 1.221 1.228 1.107 1.119 1.16 0.607 12 1.449 1.303 1.391 1.195 1.188 1.332 0.899 0 19704 0 20958 21516 0 22544 P1 TR1 P1 TR1 TR1 TR1 P3 1.12 1.132 1.082 1.143 1.166 1.048 0.323 13 1.211 1.252 1.155 1.266 1.334 1.342 0.666 22448 0 22845 0 0 0 36726 TR1 TR1 TR1 TR1 P1 P2 1.065 1.055 1.083 1.012 0.618 0.371 14 1.261 1.238 1.298 1.262 0.898 0.771 0 0 0 0 22225 34098 P2 P2 P2 P2 0.471 0.437 0.395 0.31 15 0.734 0.722 0.676 0.635 31889 33649 37102 41846

Region Assembly Power Max Rod Power Assembly Burnup

Figure 9: BOC Power and Burnup Distributions for Transition 1

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Evaluation of the Transition to Westinghouse RFA-2 Fuel

H G F E D C B A

TR1 P1 TR1 P1 TR1 P1 TR1 P2 1.304 1.019 1.291 0.975 1.303 1.059 1.216 0.549 8 1.341 1.059 1.348 1.028 1.362 1.101 1.33 0.809 25914 42184 25184 41514 26587 44688 24088 42063 P1 TR1 P1 P1 P1 TR1 TR1 P2 1.019 1.286 0.978 0.955 1.049 1.29 1.223 0.516 9 1.059 1.328 1.039 1.003 1.131 1.342 1.352 0.789 42201 25665 42814 41247 41479 26060 24182 43564 TR1 P1 TR1 P1 TR1 P1 TR1 P2 1.291 0.978 1.257 1.049 1.343 1.063 1.227 0.48 10 1.348 1.039 1.312 1.127 1.39 1.108 1.361 0.786 25177 42795 25173 41110 26896 44732 24129 44673 P1 P1 P1 TR1 P1 TR1 TR1 P2 0.975 0.954 1.047 1.297 1.025 1.313 1.129 0.373 11 1.028 1.001 1.126 1.339 1.068 1.369 1.334 0.707 41493 41352 41195 26202 41865 26096 21892 48302 TR1 P1 TR1 P1 P1 TR1 P1 1.304 1.048 1.342 1.024 1.011 1.267 0.655 12 1.363 1.13 1.39 1.067 1.063 1.369 0.935 26559 41560 26849 41913 42368 24949 35012 P1 TR1 P1 TR1 TR1 TR1 P3 1.06 1.29 1.063 1.314 1.27 1.055 0.36 13 1.102 1.342 1.107 1.37 1.371 1.277 0.692 44636 26015 44763 26096 25042 20467 43201 TR1 TR1 TR1 TR1 P1 P2 1.217 1.223 1.225 1.13 0.662 0.401 14 1.331 1.352 1.36 1.335 0.932 0.777 24084 24125 24043 21886 34871 41482 P2 P2 P2 P2 0.549 0.515 0.471 0.371 15 0.807 0.792 0.755 0.704 42103 43207 45708 48543

Region Assembly Power Max Rod Power Assembly Burnup

Figure 10: EOC Power and Burnup Distributions for Transition 1

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Evaluation of the Transition to Westinghouse RFA-2 Fuel

H G F E D C B A

TR1 TR1 TR1 TR1 TR2 TR1 TR2 TR1 1.342 1.373 1.322 1.196 1.134 1.122 1.043 0.485 8 1.394 1.427 1.375 1.28 1.235 1.177 1.243 0.749 25912 25181 24086 25669 0 25184 0 26583 TR1 TR2 TR1 TR2 TR1 TR1 TR2 P1 1.373 1.298 1.334 1.208 1.182 1.145 1.019 0.366 9 1.427 1.403 1.407 1.329 1.275 1.21 1.221 0.566 25174 0 24123 0 24125 26899 0 35018 TR1 TR1 TR2 TR1 TR1 TR2 TR2 P2 1.322 1.336 1.26 1.307 1.186 1.102 0.989 0.329 10 1.375 1.409 1.358 1.371 1.267 1.222 1.208 0.549 24082 24044 0 25061 26114 0 0 43564 TR1 TR2 TR1 TR1 TR2 TR1 TR2 P1 1.197 1.21 1.308 1.364 1.186 1.213 1.057 0.274 11 1.281 1.33 1.372 1.436 1.328 1.283 1.33 0.531 25663 0 24959 20473 0 21897 0 41192 TR2 TR1 TR1 TR2 TR1 TR2 TR1 1.134 1.182 1.186 1.187 1.174 1.205 0.63 12 1.235 1.275 1.268 1.328 1.224 1.354 0.959 0 24181 26099 0 26198 0 26057 TR1 TR1 TR2 TR1 TR2 TR2 P2 1.122 1.145 1.102 1.214 1.206 1.05 0.315 13 1.177 1.21 1.222 1.284 1.354 1.373 0.655 25170 26881 0 21891 0 0 48488 TR2 TR2 TR2 TR2 TR1 P2 1.043 1.02 0.991 1.058 0.631 0.315 14 1.243 1.22 1.209 1.332 0.959 0.655 0 0 0 0 26013 48517 TR1 P1 P2 P1 0.485 0.366 0.331 0.274 15 0.749 0.566 0.555 0.532 26555 34878 43207 41107

Region Assembly Power Max Rod Power Assembly Burnup

Figure 11: BOC Power and Burnup Distributions for Transition 2

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Evaluation of the Transition to Westinghouse RFA-2 Fuel

H G F E D C B A

TR1 TR1 TR1 TR1 TR2 TR1 TR2 TR1 0.968 1.033 1.011 1.052 1.283 1.055 1.257 0.611 8 0.987 1.062 1.049 1.091 1.336 1.088 1.363 0.89 46711 47453 45583 47395 25216 46269 23433 37258 TR1 TR2 TR1 TR2 TR1 TR1 TR2 P1 1.033 1.248 1.1 1.282 1.058 1.087 1.252 0.48 9 1.063 1.322 1.167 1.337 1.085 1.143 1.377 0.701 47448 25786 47437 25954 45733 48836 23316 43266 TR1 TR1 TR2 TR1 TR1 TR2 TR2 P2 1.011 1.1 1.3 1.09 1.054 1.33 1.201 0.424 10 1.049 1.168 1.354 1.15 1.105 1.396 1.364 0.68 45581 47381 26878 48190 47957 25953 22565 50884 TR1 TR2 TR1 TR1 TR2 TR1 TR2 P1 1.052 1.282 1.091 1.136 1.318 1.141 1.096 0.327 11 1.091 1.337 1.152 1.235 1.37 1.185 1.306 0.609 47391 25970 48114 44502 26618 45095 21132 46910 TR2 TR1 TR1 TR2 TR1 TR2 TR1 1.283 1.058 1.054 1.318 1.089 1.243 0.633 12 1.336 1.085 1.105 1.37 1.123 1.358 0.892 25216 45783 47950 26622 48684 24704 38055 TR1 TR1 TR2 TR1 TR2 TR2 P2 1.055 1.087 1.33 1.141 1.243 1.023 0.335 13 1.089 1.143 1.396 1.186 1.358 1.262 0.65 46257 48818 25960 45097 24708 19891 54545 TR2 TR2 TR2 TR2 TR1 P2 1.257 1.252 1.202 1.096 0.633 0.335 14 1.363 1.377 1.364 1.306 0.892 0.65 23434 23320 22581 21146 38021 54574 TR1 P1 P2 P1 0.611 0.481 0.425 0.328 15 0.89 0.701 0.681 0.609 37233 43145 50564 46839

Region Assembly Power Max Rod Power Assembly Burnup

Figure 12: EOC Power and Burnup Distributions for Transition 2

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Evaluation of the Transition to Westinghouse RFA-2 Fuel

H G F E D C B A

EQ1 N1 EQ1 N1 EQ1 N1 EQ1 N1 1.303 1.364 1.217 1.215 1.176 1.282 1.15 0.523 8 1.392 1.421 1.353 1.283 1.289 1.363 1.364 0.803 0 24462 0 24144 0 24142 0 25892 N1 N1 N1 EQ1 N1 N1 EQ1 N2 1.364 1.311 1.24 1.153 1.182 1.248 1.102 0.427 9 1.421 1.379 1.355 1.254 1.247 1.348 1.332 0.704 24462 25148 23088 0 25575 24112 0 42938 EQ1 N1 EQ1 N1 N1 EQ1 EQ1 N2 1.217 1.242 1.181 1.18 1.167 1.129 1.035 0.379 10 1.353 1.357 1.303 1.251 1.224 1.237 1.232 0.651 0 22993 0 26430 26222 0 0 46381 N1 EQ1 N1 N1 EQ1 N1 EQ1 N2 1.215 1.156 1.181 1.324 1.166 1.219 1.051 0.299 11 1.283 1.256 1.251 1.413 1.289 1.292 1.341 0.607 24144 0 26430 19341 0 20908 0 47156 EQ1 N1 N1 EQ1 N1 EQ1 N2 1.176 1.185 1.168 1.167 1.16 1.162 0.543 12 1.289 1.253 1.221 1.289 1.206 1.323 0.951 0 25634 26260 0 25740 0 44046 N1 N1 EQ1 N1 EQ1 EQ1 N2 1.282 1.254 1.133 1.221 1.163 0.997 0.293 13 1.363 1.353 1.241 1.294 1.324 1.323 0.61 24142 24305 0 20946 0 0 47708 EQ1 EQ1 EQ1 EQ1 N2 N2 1.15 1.114 1.042 1.054 0.544 0.293 14 1.364 1.342 1.236 1.345 0.952 0.61 0 0 0 0 44083 47779 N1 N2 N2 N2 0.523 0.446 0.383 0.302 15 0.803 0.747 0.654 0.612 25892 36950 46949 46930

Region Assembly Power Max Rod Power Assembly Burnup

Figure 13: BOC Power and Burnup Distributions for Equilibrium 1

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Evaluation of the Transition to Westinghouse RFA-2 Fuel

H G F E D C B A

EQ1 N1 EQ1 N1 EQ1 N1 EQ1 N1 1.221 1.053 1.287 1.152 1.3 1.105 1.249 0.592 8 1.276 1.116 1.353 1.194 1.359 1.15 1.359 0.857 24890 46728 26003 47914 26103 47093 24331 36720 N1 N1 N1 EQ1 N1 N1 EQ1 N2 1.053 1.007 1.081 1.3 1.054 1.111 1.24 0.504 9 1.116 1.031 1.106 1.36 1.102 1.148 1.368 0.769 46728 46576 45462 25958 47475 46999 23941 51852 EQ1 N1 EQ1 N1 N1 EQ1 EQ1 N2 1.287 1.082 1.28 1.04 1.05 1.324 1.192 0.45 10 1.353 1.108 1.331 1.082 1.102 1.388 1.354 0.728 26003 45400 25632 48061 47939 26083 22834 54357 N1 EQ1 N1 N1 EQ1 N1 EQ1 N2 1.152 1.301 1.04 1.142 1.316 1.142 1.076 0.343 11 1.194 1.361 1.082 1.247 1.372 1.186 1.295 0.657 47914 25999 48067 43040 26261 44009 20759 53213 EQ1 N1 N1 EQ1 N1 EQ1 N2 1.3 1.054 1.049 1.316 1.093 1.224 0.562 12 1.359 1.102 1.101 1.372 1.131 1.352 0.888 26103 47563 47981 26262 48122 23912 54399 N1 N1 EQ1 N1 EQ1 EQ1 N2 1.105 1.111 1.323 1.141 1.223 1.001 0.322 13 1.15 1.147 1.388 1.185 1.352 1.25 0.625 47093 47242 26123 44053 23914 19070 53423 EQ1 EQ1 EQ1 EQ1 N2 N2 1.249 1.246 1.193 1.076 0.562 0.321 14 1.359 1.371 1.355 1.295 0.887 0.623 24331 24126 22916 20790 54438 53485 N1 N2 N2 N2 0.592 0.518 0.451 0.344 15 0.857 0.808 0.724 0.659 36720 46299 54964 53019

Region Assembly Power Max Rod Power Assembly Burnup

Figure 14: EOC Power and Burnup Distributions for Equilibrium 1

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H G F E D C B A

EQ1 EQ1 EQ1 EQ1 EQ2 EQ1 EQ2 EQ1 1.334 1.345 1.258 1.258 1.184 1.284 1.147 0.518 8 1.383 1.425 1.313 1.314 1.291 1.364 1.362 0.797 24890 24331 26003 23914 0 23912 0 26103 EQ1 EQ2 EQ1 EQ2 EQ1 EQ1 EQ2 N1 1.345 1.237 1.233 1.171 1.182 1.248 1.1 0.428 9 1.425 1.362 1.321 1.29 1.249 1.35 1.33 0.7 24331 0 22916 0 25958 23941 0 43040 EQ1 EQ1 EQ2 EQ1 EQ1 EQ2 EQ2 N1 1.258 1.234 1.167 1.182 1.167 1.127 1.031 0.377 10 1.313 1.324 1.263 1.25 1.22 1.235 1.227 0.647 26003 22834 0 26261 26083 0 0 46728 EQ1 EQ2 EQ1 EQ1 EQ2 EQ1 EQ2 N1 1.258 1.175 1.183 1.325 1.164 1.217 1.046 0.297 11 1.314 1.294 1.247 1.414 1.287 1.289 1.335 0.603 23914 0 26262 19070 0 20759 0 47242 EQ2 EQ1 EQ1 EQ2 EQ1 EQ2 N1 1.184 1.185 1.168 1.165 1.158 1.161 0.544 12 1.291 1.244 1.22 1.288 1.203 1.321 0.949 0 25999 26123 0 25632 0 44009 EQ1 EQ1 EQ2 EQ1 EQ2 EQ2 N1 1.284 1.253 1.13 1.219 1.162 1.001 0.302 13 1.364 1.354 1.239 1.291 1.321 1.323 0.643 23912 24126 0 20790 0 0 45462 EQ2 EQ2 EQ2 EQ2 N1 N1 1.147 1.114 1.039 1.051 0.545 0.302 14 1.362 1.34 1.232 1.34 0.95 0.644 0 0 0 0 44053 45400 EQ1 N1 N1 N1 0.518 0.449 0.383 0.3 15 0.797 0.743 0.653 0.609 26103 36720 47093 46999

Region Assembly Power Max Rod Power Assembly Burnup

Figure 15: BOC Power and Burnup Distributions for Equilibrium 2

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H G F E D C B A

EQ1 EQ1 EQ1 EQ1 EQ2 EQ1 EQ2 EQ1 1 1.059 1.011 1.114 1.294 1.108 1.252 0.591 8 1.02 1.111 1.036 1.177 1.35 1.154 1.362 0.856 45965 46381 47151 46903 25892 46949 24461 36951 EQ1 EQ2 EQ1 EQ2 EQ1 EQ1 EQ2 N1 1.059 1.261 1.082 1.286 1.049 1.114 1.244 0.508 9 1.111 1.328 1.14 1.34 1.093 1.151 1.371 0.771 46381 25148 45057 25575 47708 46930 24112 52078 EQ1 EQ1 EQ2 EQ1 EQ1 EQ2 EQ2 N1 1.011 1.083 1.297 1.046 1.053 1.326 1.195 0.452 10 1.036 1.142 1.35 1.087 1.108 1.39 1.357 0.73 47151 45003 25740 47948 47881 26222 22993 54762 EQ1 EQ2 EQ1 EQ1 EQ2 EQ1 EQ2 N1 1.114 1.287 1.046 1.148 1.32 1.146 1.078 0.343 11 1.177 1.342 1.09 1.252 1.376 1.189 1.297 0.658 46903 25634 47963 42938 26429 44046 20908 53340 EQ2 EQ1 EQ1 EQ2 EQ1 EQ2 N1 1.294 1.05 1.052 1.319 1.096 1.228 0.566 12 1.35 1.095 1.107 1.375 1.134 1.355 0.891 25892 47779 47927 26430 48203 24142 54496 EQ1 EQ1 EQ2 EQ1 EQ2 EQ2 N1 1.108 1.114 1.326 1.145 1.227 1.008 0.333 13 1.154 1.151 1.39 1.188 1.355 1.254 0.656 46949 47156 26260 44083 24143 19341 51364 EQ2 EQ2 EQ2 EQ2 N1 N1 1.252 1.25 1.197 1.078 0.566 0.333 14 1.362 1.374 1.358 1.297 0.89 0.656 24461 24305 23088 20946 54546 51307 EQ1 N1 N1 N1 0.591 0.524 0.454 0.345 15 0.856 0.809 0.728 0.661 36951 46230 55194 53137

Region Assembly Power Max Rod Power Assembly Burnup

Figure 16: EOC Power and Burnup Distributions for Equilibrium 2

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3.2 Technical Analysis

3.2.1 TS 2.0 Safety Limits Changes

Background

Based on design comparisons and hydraulic testing of the fuel assemblies, the Framatome HTP fuel and the Westinghouse 17x17 RFA-2 fuel assembly designs are considered to be hydraulically compatible. The Westinghouse 17x17 RFA-2 fuel design is compatible with the core components and the SQN resident Framatome HTP fuel. The dimensions of the two fuel types are essentially equivalent, i.e., the grid envelope, fuel rod, thimble and instrument tube diameters are unchanged between the Westinghouse 17x17 RFA-2 design and the Framatome HTP fuel. The thermal-hydraulic (T/H) evaluation of the 17x17 RFA-2 fuel has shown that the Westinghouse 17x17 RFA-2 and Framatome HTP fuel types are hydraulically compatible.

Methodology

The T/H analysis for the Westinghouse 17x17 RFA-2 fuel for SQN Units 1 and 2 is based on the following. 1. The Westinghouse Revised Thermal Design Procedure (RTDP) Departure from Nucleate Boiling Ratio (DNBR) Evaluation Methodology (WCAP-11397-P-A) 2. The VIPRE-W code (WCAP-14565-P-A [Reference 20]) 3. The WRB-2M DNB correlation (WCAP-15025-P-A and Letter from D. S. Collins (USNRC) to J. A. Gresham (Westinghouse), “Modified WRB-2 Correlation WRB-2M for Predicting Critical Heat Flux in 17x17 Rod Bundles with Modified LPD Mixing Vane Grids,” February 2006 [Reference 21].

WCAP-11397-P-A is referenced as the design method (RTDP) used to meet the DNB design basisin the Sequoyah current licensing basis (Reference 95 in UFSAR Section 4.4.6). In the RTDP method, uncertainties in plant operating parameters nuclear thermal parameters, fuel fabrication parameter, computer codes, and DNB correlation predictions are considered statistically to obtain DNB uncertainty factors. Based on the DNB uncertainty factors, RTDP design limit DNBR values are determined such that there is at least a 95% probability at a 95% confidence level that DNB will not occur on the most limiting fuel rod during normal operation and operational transients and during transient conditions arising from faults of moderate frequency (Condition I and II events as defined in ANSI N18.2). Because the uncertainties in these parameters are considered in determining the design DNBR value, the plant safety analyses are performed using input values without uncertainties for these parameters.

The applicability of the WRB-2M DNB correlation to analyses for Westinghouse 17x17 RFA-2 fuel is documented in WCAP-14565-P-A. The VIPRE-W models employ the WRB-2M DNB correlation for at-power events and for analyses applicable to the region above the first mixing vane grid. When any of the conditions are outside the range of the WRB-2M DNB correlation, the W-3 and W-3 Alternative (ABB-NV and WLOP) DNB correlations and a deterministic treatment of key DNBR analysis uncertainties is used. These correlations have been approved by the NRC and are described in WCAP-14565-P-A, Addendum 1-A (Reference 22), and WCAP-14565-P-A, Addendum 2-P-A (Reference 23).

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The Westinghouse PAD5 fuel performance code from WCAP-17642-P-A was used to evaluate fuel temperatures and rod internal pressure for Safety Analysis considering the Sequoyah Units 1 and 2 fuel transition conditions. Analyses were performed to predict best estimate and upper bound fuel centerline temperatures as a function of rod local burnup and power based on a limiting steady-state power history. These fuel centerline temperature analyses are the same as those performed to provide maximum fuel temperature input to LOCA and Non-LOCA safety analysis. Using these upper bound fuel centerline temperatures in conjunction with the burnup dependent fuel melting temperature limit, the local power level at which fuel centerline melt will occur is determined for each burnup step. The safety analyses confirmed that the peak linear heat rate (expressed in kW/ft) does not provide a value that could result in fuel centerline melting.

The PAD5 fuel pellet overheating (power-to-melt) analysis confirmed that fuel rods will not fail due to fuel centerline melting for Condition I and Condition II events for the Sequoyah Units 1 and 2 fuel transition conditions and will be confirmed as part of the cycle-specific Reload Safety Analysis Checklist (RSAC) along with the other PAD5 generated data for Safety Analysis.

Refer to Attachment 8 for how the Limitations and Conditions were met for each of the NRC approved methodologies applied to the proposed Sequoyah Units 1 and 2 fuel transition.

Results

TS 2.1.1, “Reactor Core SLs” Figure 2.1.1-1, “Reactor Core Safety Limit – Four Loops in Operation” resulting from the combination of Thermal Power, Reactor Coolant System (RCS) highest loop average temperature, and pressurizer pressure is revised from the application of WCAP-11397-P-A evaluation methodology. The revised reactor core safety limit figure would also be relocated to the COLR consistent with NRC-approved TSTF-339-A and WCAP-14483-A. As discussed below from the NRC Safety Evaluation for WCAP- 14483-A, the justification is provided for why this figure may be relocated to the COLR and replaced with the DNB design basis limit and the fuel centerline melt limit.

“The current TS figure (2.1.1-1) presents core limits on RCS temperature conditions (T-avg) as a function of pressurizer pressure and fractional rated thermal power. This figure was originally included in the Westinghouse TS to satisfy the requirements of 10CFR50.36 which states that ‘safety limits for nuclear reactors are limits upon important process variables that are found to be necessary to reasonably protect the integrity of certain physical barriers that guard against the uncontrolled release of radioactivity.’ However, the figure is not a complete representation of reactor core safety limits but is intended to provide the relationship between the process variables that are available to the operator (i.e., T-avg, pressurizer pressure, and thermal power) and the DNB design basis safety limit.

To ensure that the requirements of 10CFR50.36 are met, i.e., limits upon important process variables, the WOG has proposed to retain the requirement for a Reactor Core Limits figure in the Safety Limits TS, but relocate the actual figure to the COLR and replace it with the DNB design basis limit and the fuel centerline melt limit (Ref. 2). Both of these limits are criteria that must be satisfied for normal operation and for AOOs to prevent overheating of the fuel cladding and possible cladding perforation which would

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result in the release of fission products to the RCS and are, therefore, the true safety limits. The reactor protection system (RPS) and the Reactor Core Limits figure would then be used to determine whether the actual DNB and fuel centerline melt safety limits were violated should an event occur that could potentially challenge them. Appropriate functioning of the RPS and the steam generator safety valves ensures that for variations in the thermal power, RCS pressure, RCS average temperature, RCS flow rate, and ǻI (percent power in top half of core minus percent power in bottom half of core), the reactor core safety limits will be satisfied during steady-state operation, normal operational transients, and AOOs. Therefore, in the event of an AOO, verification that the RPS and the main steam system safety valves are functioning as designed will ensure that all safety limits are met. In the event that the RPS is not functioning as designed, an evaluation of any transient condition would be required to determine whether or not the safety limits have been violated.

In addition, since the Reactor Core Limits figure is based on the nuclear enthalpy rise N hot channel factor limit, F 废宋. and the RCS total flow rate, both of which may be in the COLR, relocation of the figure to the COLR would eliminate the need for a license amendment if cycle-dependent changes to these parameters were to exist.

The staff concludes that the Reactor Core Limits figure may be relocated to the COLR and replaced with the DNB design basis limit and the fuel centerline melt limit. The NRC-approved methodology used to derive the parameters in the figure is contained in WCAP-9272-P-A, "Westinghouse Reload Safety Evaluation Methodology," dated July 1985, (or other applicable approved reload methodology), and will be referenced in the Reporting Requirements section of the TS.”

Relocating the reactor core safety limit figure from TS 2.1.1 to the COLR will also be consistent with TS 2.1.1 in NUREG-1431. The DNB design basis limit and the fuel centerline melt limit are contained in Reactor Core Safety Limits 2.1.1.1 and 2.1.1.2.

Reactor Core Safety Limit 2.1.1.1 is revised from the application of WCAP-15025-P-A evaluation methodology. The change would replace the three Framatome correlation departure from nucleate boiling ratio (DNBR) values with the WRB-2M correlation DNBR value. With the significant improvement in the accuracy of the critical heat flux (CHF) prediction by using the WRB-2M correlation instead of previous DNB correlations, a DNBR limit of 1.14 is applicable for the 17x17 RFA-2 Standard fuel assembly.

Reactor Core Safety Limit 2.1.1.2 is revised from the application of WCAP-17642-P-A evaluation methodology. The change would replace the peak fuel centerline temperature derived from Framatome methodology with the Westinghouse PAD5 peak fuel centerline temperature value. With PAD5, an improved melting temperature model is used in which burnup has less of an impact on the fuel melt temperature limit, as indicated by the following equation that is conservatively based on the UO2 fuel melting point equation used in PAD5.

Tmelt = 5080°F – __9__ (BU) 10000 where, Tmelt = UO2 melting temperature, °F BU = UO2 burnup, MWD/MTU

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Summary and Conclusions

The T/H evaluation of the 17x17 RFA-2 fuel has shown that the Westinghouse 17x17 RFA-2 and Framatome HTP fuel types are hydraulically compatible. The existing DNB methodology is applicable with the addition of the transition core DNB effect. The design criteria associated with rod bow, fuel temperatures, bypass flow, core component analysis, void fraction, and hydrodynamic stability have been satisfied.

The PAD5 fuel performance code was used to assess the fuel rod design criteria and generate the fuel performance data (i.e., fuel temperatures, rod internal pressure, and fuel centerline melt for the respective downstream analyses). Fuel performance evaluations were completed for each of the representative fuel regions to demonstrate that the design criteria can be satisfied for all fuel rod types in the core under the planned operating conditions for the Sequoyah Units 1 and 2 proposed fuel transition. Cycle-specific core designs and fuel performance analyses are performed for each reload cycle to guarantee that the fuel rod design criteria will remain satisfied for cycle-specific operating conditions.

3.2.2 TS 3.1 Reactivity Control Systems Changes

Background

TS 3.1.4, “Rod Group Alignment Limits” Required Action B.2.4 is revised to be consistent with FQ surveillance requirement numbering changes to TS 3.2.1. The proposed changes to TS 3.2.1 (discussed in subsection 3.2.3 of this enclosure) will address the issues identified in Westinghouse Nuclear Safety Advisory Letter (NSAL) NSAL-09-5, Revision 1, “Relaxed Axial Offset Control FQ Technical Specification Actions” (Reference 24), and also will address issues identified in NSAL-15-1, “Heat Flux Hot Channel Factor Technical Specification Surveillance” (Reference 25).

TS 3.1.7, “Rod Position Indication” Required Actions A.1, A.2.1, B.3, and C.1 are revised to implement BEACON core power distribution measurement consistent with WCAP-12472-P-A, and WCAP-12472-P-A, Addendum 4-A, and replace using “movable incore detectors” with “core power distribution measurement information”. The proposed TS 3.1.7 changes will allow the use of a dedicated on-line core power distribution monitoring system (PDMS) to enhance surveillance of core thermal limits. The PDMS to be used at SQN Units 1 and 2 is the NRC-approved Westinghouse proprietary core analysis system called Best Estimate Analyzer for Core Operations – Nuclear (BEACON). Currently, for conditions involving inoperable rod position indicators, Required Actions A.1, A.2.1, B.3, and C.1 require plant operators to verify the position of the rod(s) with inoperable position indicators by using movable incore detectors. The generic phrase “core power distribution measurement information” is substituted for “movable incore detectors,” as this would allow the use of either a PDMS or the movable incore detectors for verifying the position of the rod(s) with an inoperable rod position indicator.

Methodology

As discussed in WCAP-17661-P-A, the Heat Flux Hot Channel Factor [FQ(Z)] TS provides assurance that the heat flux hot channel factor, FQ, will remain within the limits assumed in the plant safety analyses when the core is operated within its allowed operating space. Performing SR 3.2.1.1 and SR 3.2.1.2 verifies that that FQ(Z), as approximated by C equilibrium FQ(Z) [FQ (Z)] and transient FQ(Z) for future non-equilibrium operation within the

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W allowed operating space [FQ (Z)], are within the limits specified in the COLR. The application of WCAP-17661-P-A is discussed in more detail in subsection 3.2.3 of this enclosure.

As described in WCAP-12472-P-A, the Westinghouse BEACON PDMS was developed to improve the operational support for pressurized water reactors (PWRs). BEACON is an advanced core monitoring and support package that utilizes existing plant instrumentation such as core exit thermocouple temperatures, reactor coolant system (RCS) cold leg temperatures, control bank positions, power range detector output, and reactor power level. These data are sent by the plant computer in the form of a file that BEACON can interpret to perform nodal power distribution prediction calculations. The PDMS does not provide any protection or control system function.

The BEACON-TSM (Technical Specification Monitor) system level was developed to provide licensees with the functionality needed to integrate BEACON into the plant TS for monitoring of current TS thermal power limits such as peak linear power density (FQ – TS 3.2.1, Heat N Flux Hot Channel Factor (FQ(Z))) and peak enthalpy rise (F ǻ+ – TS 3.2.2, Nuclear N Enthalpy Rise Hot Channel Factor (F ǻ+)). The application of WCAP-12472-P-A, and WCAP-12472-P-A, Addendum 4-A is discussed in detail in subsection 3.2.3 of this enclosure.

Refer to Attachment 8 of this Enclosure for how the Limitations and Conditions were met for each of the NRC approved methodologies that were applied for the proposed Sequoyah Units 1 and 2 fuel transition.

Results

TS 3.1.4 Required Action B.2.4 for continued operation with a misaligned rod verifies that hot channel factors FQ(Z) are within limits. Required Action B.2.4 is revised to add “and SR 3.2.1.2” consistent with changes to TS 3.2.1 Surveillance Requirements (SRs) from Appendix A of WCAP-17661-P-A. The revised TS 3.1.4 Required Action B.2.4 would C require performance of both SR 3.2.1.1 to “Verify FQ (Z) is within limit”, and SR 3.2.1.2 to W “Verify FQ (Z) is within limit”. Performing SR 3.2.1.1 and SR 3.2.1.2 verifies that FQ(Z), as C W approximated by FQ (Z) and FQ (Z), is within the required limits and ensures that operation DW”573ZLWKDURGPLVDOLJQHGZLOOQRWUHVXOWLQSRZHUGLVWULEXWLRQVWKDWPD\LQYDOLGDWH safety analysis assumptions at full power.

Rod position may be determined indirectly by use of core power distribution measurement information. Core power distribution measurement information can be obtained from flux maps using the movable incore detectors, or from a functional PDMS. TS 3.1.7, “Rod Position Indication” Required Actions A.1, A.2.1, B.3, and C.1 are revised to implement BEACON core power distribution measurement consistent with WCAP-12472-P-A, and WCAP-12472-P-A, Addendum 4-A, and replace using “movable incore detectors” with “core power distribution measurement information.”

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Summary and Conclusions

The Reactivity Control Systems TS 3.1.4 and TS 3.1.7 Required Action changes are consistent with the changes from the application of WCAP-17661-P-A, WCAP-12472-P-A, and WCAP-12472-P-A, Addendum 4-A. Application of these NRC approved topical reports is discussed in more detail in subsection 3.2.3 of this enclosure.

3.2.3 TS 3.2 Power Distribution Limits Changes

TS 3.2.1 Change Discussion

TS 3.2.1, “Heat Flux Hot Channel Factor (FQ(X,Y,Z)),” is revised to implement the methodology and Technical Specification markups consistent with TS 3.2.1, “Heat Flux Hot Channel Factor (FQ(Z)),” from Appendix A of WCAP-17661-P-A (Reference 12), with deviations to the Condition B Required Action Completion Times based on References 30 and 31, for RAOC plants using the format and much of the content contained within NUREG-1431 Revision 4 (Reference 9). Additionally, TS 5.6.3.b would be revised to list WCAP-17661-P-A Revision 1 as a COLR methodology reference.

NSAL-09-5, Revision 1, “Relaxed Axial Offset Control FQ Technical Specification Actions,” dated September 23, 2009, (Reference 24), notified Westinghouse customers of an issue associated with the Required Actions for Condition B of NUREG-1431 (Reference 9) TS 3.2.1B, “Heat Flux Hot Channel Factor (FQ(Z) (RAOC-W(Z) Methodology),” for plants that have implemented the W RAOC methodology. In certain situations where transient FQ, FQ (Z), is not within its limit, the W existing Required Actions may be insufficient to restore FQ (Z) to within the limit.

NSAL-15-1, “Heat Flux Hot Channel Factor Technical Specification Surveillance,” dated February 3, 2015, (Reference 25) notified Westinghouse customers of an issue associated with Surveillance Requirement (SR) 3.2.1.2 of NUREG-1431 (Reference 9). Specifically, one aspect of the SR may not be sufficient to assure that the peaking factor assumed in the licensing basis analysis remains valid under all conditions between the instances of performance of SR 3.2.1.2. Implementing the TS changes of WCAP-17661-P-A, Revision 1, will resolve the non-conservatism identified in NSAL-15-1 by inclusion of the penalty factor from the NUREG-1431 SR 3.2.1.2 NOTE in the surveillance formulation and therefore make it applicable at all times as part of the SQN Unit 1 and 2 transition to Westinghouse RFA-2 fuel.

These non-conservatisms identified in NSAL-09-5 Revision 1 and NSAL-15-1 are not applicable to the current SQN TS 3.2.1, but are applicable to the NUREG-1431 TS 3.2.1B. The proposed changes to TS 3.2.1 implement a modified version of NUREG-1431 TS 3.2.1B from WCAP-17661-P-A that will resolve the non-conservatisms identified in NSAL-09-5 Revision 1 and NSAL-15-1 as part of the SQN Unit 1 and 2 transition to Westinghouse RFA-2 fuel.

The improved FQ surveillance methodology in WCAP-17661-P-A resolves the issues identified in NSAL-09-5 Revision 1 and NSAL-15-1. The new surveillance methodology requires the measurement of FXY(Z), which is then multiplied by factors that characterize the maximum transient T(Z) values postulated to occur during non-equilibrium operation. This formulation essentially eliminates the sensitivity of the surveillance to the surveillance axial power shape. Additionally, the improved FQ surveillance methodology incorporates various RAOC operating spaces, consisting of combinations of control bank rod insertion, AFD, and thermal power limits

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that provides sufficient FQ margin for future operation. These improvements to TS 3.2.1 are discussed below in the "Methodology for 3.2.1 Changes” section of this enclosure.

The Completion Times for Required Actions B.2.1, B.2.2, and B.2.3 have been revised from the Technical Specification markups of WCAP-17661-P-A Revision 1 Appendix A, based on information contained in References 30 and 31

TSTF-241-A Revision 4 (Reference 30) approved the addition of “after each FQ(Z) determination” to the Completion Times of STS 3.2.1A Required Actions A.1 through A.4 and C “after each FQ (Z) determination” to the Completion Times of STS 3.2.1B Required Actions A.1 through A.3. These changes were made to assure that the Required Actions were continued, with the associated Completion Time resets, after subsequent peaking factor determinations were made while continuing to operate under the applicable Condition with the peaking factor parameter not within its limit. The NRC approved Reference 30 on January 13, 1999.

TSTF-290-A Revision 0 (Reference 31) made the following changes of note for this license amendment request.

x Deleted Required Action A.2 of STS 3.2.1A (renumbering the subsequent Required Actions of that LCO) and renamed STS 3.2.1A to “FQ(Z) (CAOC-Fxy Methodology)”

x Added new Required Actions B.2 and B.3 to STS 3.2.1B and renamed STS 3.2.1B to “FQ(Z) (RAOC-W(Z) Methodology)”

x Added new STS 3.2.1C (“FQ(Z) (CAOC-W(Z) Methodology)”

The NRC approved Reference 31 on June 30, 1999.

Both References 30 and 31 were included in STS NUREG-1431 Revision 2 (published by the NRC in June 2001). However, the related effects of References 30 and 31 were not reconciled in the various versions of the FQ STS 3.2.1 prior to publication of STS NUREG-1431 Revision 2. It appears that all Required Actions in Reference 31 which required either a power reduction or reactor trip setpoint change should have had a Completion Time that was reset after each FQ determination, the intent of Reference 30. The logic for this is as follows.

TSTF-290 introduced a new Condition B with Required Actions and Completion Times similar to those in Condition A. However, the parallel work on TSTF-241 appears to have not been reconciled to TSTF-290 to recognize the new Condition B and did not include the appropriate Completion Time changes for Condition B.

TS 3.2.1 Bases in WCAP-17661-P-A Revision 1 Appendix B makes the following statements for Required Action B.2.1:

“The Completion Time of 4 hours provides an acceptable time to reduce the THERMAL POWER and AFD limits in an orderly manner to preclude entering an unacceptable condition during future non-equilibrium operation. The limit on THERMAL POWER initially determined by Required Action B.2.1 may be affected by subsequent W determinations of FQ (Z) that are not within limit and would require power reductions W within 4 hours of the FQ (Z) determination if necessary to comply with the decreased

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W THERMAL POWER limit. Decreases in FQ (Z) would allow increasing the THERMAL POWER limit and increasing THERMAL POWER up to this revised limit.”

C The steady state FQ (Z) peaking factor Completion Times for new Actions A.1, A.2, and A.3 in C TS 3.2.1 allow for subsequent Completion Time resets after each steady state FQ (Z) peaking factor determination. However, the Completion Times for new Actions B.2.1 through B.2.3 in WCAP-17661-P-A Revision 1 Appendix A do not allow for subsequent Completion Time resets W after each transient FQ (Z) peaking factor determination.

W This license amendment request proposes that subsequent transient FQ (Z) peaking factor determinations while the plant continues to operate in Condition B, either pursuant to Required Action B.2.4 or from the nominal performance of SR 3.2.1.2 if it should come due while the plant remains in Condition B, should reset the Completion Times for Required Actions B.2.1, B.2.2, W and B.2.3. Without the required Completion Time resets, subsequent transient FQ (Z) peaking factor determinations that occur after 4 hours (Required Action B.2.1) or 72 hours (Required Actions B.2.2 and B.2.3) would be met with an expired Completion Time resulting in a required shutdown to MODE 2.

TS 3.2.2 Change Discussion

TS 3.2.2, “Nuclear Enthalpy Rise Hot Channel Factor Fǻ+(X,Y),” is revised to reflect N TS 3.2.2, “Nuclear Enthalpy Rise Hot Channel Factor (F 'H),” in Reference 9. Adopting the latest version of the NRC-approved Standard Technical Specification 3.2.2 essentially returns the Sequoyah Units 1 and 2 Technical Specifications to their licensing basis for the

F¨H LCO prior to Reference 26 which addressed their conversion from Westinghouse fuel to Framatome Cogema Fuel, except for two Completion Times (CTs).

Prior to Reference 26, with F¨H not within limit, Sequoyah Units 1 and 2 had an Action to reduce Thermal Power to less than 50% of Rated Thermal Power (RTP) within 2 hours. During the industry efforts following the NRC’s Interim Policy Statement on Technical Specification Improvements (52 FR 3788) which led up to NUREG-1431 Revision 0 (September 1992), WCAP-12159, “MERITS Program, Phase II, Technical Specifications and Bases,” March 1989, used the Vogtle Unit 1 Technical Specifications of that vintage as the latest licensed version of TS 3.2.2. The CT for the 50% power reduction was 4 hours in the Vogtle licensing basis at that time. The 4-hour CT was also used in WCAP-13029 Volume 1, “MERITS Program, Phase III, Comments on Draft NUREG-1431, Standard Technical Specifications – Westinghouse Plants,” July 1991, and has been used ever since with the NRC’s approval in NUREG-1431 Revisions 0 through 4. The 4-hour CT for this power reduction is acceptable because it provides an appropriate time to reach the required power level from full power operation without allowing the plant to remain in an unacceptable condition for an extended period of time.

Prior to Reference 26, with F¨H not within limit, Sequoyah Units 1 and 2 also had an Action to reset the power range neutron flux WULSVHWSRLQWVWR”55% RTP within 6 hours. Similar to the discussion above, this CT was 8 hours in the Vogtle licensing basis at that time, which was also used in WCAP-12159 and WCAP-13029 Volume 1 and used with the NRC’s approval in NUREG-1431 Revisions 0 and 1. Prior to the issuance of NUREG-1431 Revision 2, the NRC approved TSTF-95-A to increase this CT to 72 hours by letter from Christopher I. Grimes (NRC OTSB) to James Davis (NEI) dated 9-27-96. TSTF-95-A was cited in the NRC’s approval of the 72-hour CT in LA274/155 for Beaver Valley Units 1 and 2 dated

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2-27-06 (ADAMS Accession Number ML060330636). The 72-hour CT for resetting the trip setpoints is acceptable, recognizing that after the power level is reduced the safety analysis assumptions are satisfied. This CT balances the non-urgent need to reset the trip setpoints against the sensitivity of an operation that could inadvertently trip the reactor.

TS 3.2.4 Change Discussion

TS 3.2.4, “Quadrant Power Tilt Ratio (QPTR),” Required Actions A.3 and A.6 are changed to be consistent with the Surveillance Requirement numbering in revised TS 3.2.1 and revised TS 3.2.2. SR 3.2.4.2 would also be changed to implement BEACON core power distribution measurement consistent with WCAP-12472-P-A (Reference 13) and WCAP-12472-P-A, Addendum 4-A (Reference 14), and replace the discussion of flux maps obtained solely using the movable incore detectors with more generic terminology (i.e., “core power distribution measurement information”). The basis for implementing the BEACON methodology was previously discussed in subsection 3.2.2.

Methodology for TS 3.2.1 Changes

Heat Flux Hot Channel Factor (FQ(Z))

FQ(Z) is defined as the maximum local fuel rod linear power density divided by the average fuel rod linear power density and is a measure of the peak fuel pellet power within the reactor core. The values of FQ vary along the axial height (Z) of the core. FQ(Z) also varies with fuel loading patterns, control bank insertion, fuel burnup, and changes in axial power distribution. The purpose of the limits on the values of FQ(Z) is to limit the local (i.e., pellet) peak power density.

FQ(Z) is measured periodically using either the movable incore detector system (MIDS) or the power distribution monitoring system (PDMS). Because these measurements are generally taken with the core at or near equilibrium conditions, the measured FQ(Z) does not include the variations which would be present during non-equilibrium situations, such as load following or power ascension.

To account for these possible variations, the equilibrium values of FQ(Z) are adjusted by elevation-dependent factors that account for the expected maximum values postulated to occur during RAOC operation.

The proposed changes to TS 3.2.1 involve a re-formulation of these elevation-dependent factors, designated as [T(Z)]COLR. The proposed TS 3.2.1 incorporates various RAOC Operation Spaces (ROS) that define the corresponding elevation-dependent factors, [T(Z)]COLR. Each ROS is composed of corresponding COLR limits associated with TS 3.2.3, “Axial Flux Difference (AFD),” and TS 3.1.6, “Control Bank Insertion Limits,” assumed in the calculation of each particular [T(Z)]COLR function.

Axial Flux Difference (AFD)

The purpose of TS 3.2.3 is to establish limits on the values of AFD in order to limit the amount of axial power distribution skewing to either the top or bottom of the core. By limiting the amount of power distribution skewing, core peaking factors are consistent with the assumption used in the safety analyses. Limiting power distribution skewing over time

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also minimizes the xenon distribution skewing, which is a significant factor in axial power distribution control.

AFD is the difference in normalized flux signals between the top and bottom halves of a two-section excore neutron detector. AFD is a measure of the axial power distribution skewing to either the top or bottom half of the core. AFD is sensitive to many core-related parameters such as control bank positions, core power level, axial burnup, axial xenon distribution, and, to a lesser extent, reactor coolant temperature and boron concentration.

The allowed range of AFD is used in the nuclear design process to confirm that operation within these limits produces core peaking factors and axial power distributions that meet safety analysis requirements. The limits on AFD ensure that FQ(Z) is not exceeded during either normal operation or in the event of xenon redistribution following power changes. The limits on AFD also restrict the range of power distributions that are used as initial conditions in the analyses of Condition II, III, or IV events as described in Chapter 15 of the SQN Updated Final Safety Analysis Report (reference Attachment 10 for a summary of the safety analysis changes to the UFSAR).

RAOC, as described in WCAP-10216-P-A, Revision 1A, “Relaxation of Constant Axial Offset Control/FQ Surveillance Technical Specification,” (Reference 27), is a calculational procedure that defines the allowed operational space of the AFD versus THERMAL POWER. AFD limits are selected by considering a range of axial xenon distributions that may occur as a result of large variations of AFD. Subsequently, power peaking factors and power distributions are examined to ensure that the loss of coolant accident (LOCA), loss of flow accident, and anticipated transient limits are met. Violation of the AFD limits invalidates the conclusions of the accident and transient analyses with regard to fuel cladding integrity.

The RAOC methodology establishes a xenon distribution library with tentatively wide AFD limits. One-dimensional axial power distribution calculations are then performed to demonstrate that normal operation power shapes are acceptable for LOCA and loss of flow accident and for initial conditions of anticipated transients. The tentative limits are adjusted as necessary to meet the safety analysis requirements.

Control Bank Insertion Limits

The insertion of the control banks directly affects core power and fuel burnup distributions and assumptions of available ejected rod worth, shutdown margin (SDM), and initial reactivity insertion rate. Rod insertion limits (RILs) are established and rod positions are monitored against the RILs and controlled during power operation to ensure that the power distribution and reactivity limits defined by the design power peaking and SDM limits are preserved.

The rod cluster control assemblies (RCCAs) are divided among control banks and shutdown banks. Each bank may be further subdivided into two groups to provide for precise reactivity control (shutdown banks C and D have only one group each). A group consists of two or more RCCAs that are electrically paralleled to step simultaneously. Except for shutdown banks C and D, a bank of RCCAs consists of two groups that are moved in a staggered fashion, but always within one-step of each other. There are four control banks and four shutdown banks.

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TS 3.1.5 requires each shutdown bank to be within the insertion limits as specified in the COLR. TS 3.1.6 requires the control banks to be within the insertion, sequence, and overlap limits as specified in the COLR. The control banks are operated in sequence by withdrawal of Bank A, Bank B, Bank C, and then Bank D. The control banks are sequenced in reverse order upon insertion.

Overlap is the distance travelled together by two control banks. Upon initiation of control bank withdrawal, control bank A is withdrawn by itself. At a predetermined position, control bank B begins withdrawing, resulting in both banks withdrawing simultaneously until control bank A is fully withdrawn. Control bank B will continue withdrawing until, at a subsequent predetermined position, control bank C begins withdrawing. This process continues until control bank D is withdrawn to the full power position. As such, each bank’s overlap is the number of steps that each bank travelled from the following bank’s predetermined position to the fully withdrawn position.

The power density at any point in the core must be limited so that the fuel design criteria are maintained. Together, TS 3.1.4, “Rod Group Alignment Limits,” TS 3.1.5, TS 3.1.6, TS 3.2.3, and TS 3.2.4, “Quadrant Power Tilt Ratio (QPTR),” provide limits on control component operation and on monitored process variables, which ensure that the core operates within the fuel design criteria. The shutdown and control bank insertion and alignment limits, AFD, and QPTR are process variables that together characterize and control the three dimensional power distribution of the reactor core.

Refer to Attachment 8 for how Limitations and Conditions were met.

Results

As described in detail in WCAP-17661-P-A, the proposed change implements an improved RAOC FQ Surveillance formulation and TS. The new formulation also improves accuracy of part-power surveillances. Finally, the improved RAOC FQ Surveillance TS incorporates the concept of RAOC operating spaces that are defined in the COLR. If the FQ limit is exceeded during a surveillance, a more restrictive RAOC operating space can be implemented that provides the required additional FQ margin for future operation.

Sequoyah Technical Specification 3.2.1 is entirely replaced with a new TS which is a composite of References 9, 12, 30, and 31. New Sequoyah TS 3.2.1 is changing as compared to Westinghouse Standard TS (STS) 3.2.1B, “Heat Flux Hot Channel Factor (FQ(Z) (RAOC-W(Z) Methodology)” as follows.

Condition A

C x Revises setpoint reductions required when FQ (Z) limit is exceeded. Required Actions C A.2 and A.3 are being revised replacing “1 percent for each 1 percent FQ (Z) exceeds limits” with “1% for each 1% that THERMAL POWER is limited below RATED THERMAL POWER by Required Action A.1.” x The Note is being revised to clarify when SR 3.2.1.2 is required. x These changes are evaluated in Section 4.2 of the NRC Final Safety Evaluation included in WCAP-17661-P-A. 

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Condition B

x A new Required Action B.1.1 is included, which allows the plant to “Implement a RAOC W operating space specified in the COLR that restores FQ (Z) to within limits” whenever W FQ (Z) is determined to be not within the limits. The RAOC operating space is a unique combination of axial flux difference (AFD) limits and control bank insertion limits. The operating spaces are pre-analyzed using the approved WCAP-17661-P-A methodology and included in the COLR. x A new Required Action B.1.2 assures that for situations involving control rod movement, C W SRs 3.2.1.1 and 3.2.1.2 will be performed to ensure that FQ (Z) and FQ (Z) remain within limits. x Completion Times for Required Actions B.2.1, B.2.2, and B.2.3 with the resets discussed W above (i.e., after each FQ (Z) determination). x Other than the last bulleted item, these changes are evaluated in Section 4.3 of the NRC Final Safety Evaluation included in WCAP-17661-P-A Revision 1.

Removal of Notes for FQ Surveillance

x Two Notes are deleted in the revised SRs. The first removed Note applied to both SR 3.2.1.1 and SR 3.2.1.2 and required obtaining the power distribution map for C W measuring FQ (Z) and FQ (Z) at equilibrium conditions during power escalation at the W beginning of each cycle. The effect of the change is that FQ (Z) will not be determined until 24 hours after exceeding 75 percent of RTP, instead of within 12 hours of achieving equilibrium conditions after exceeding 75 percent RTP following refueling outages as currently specified. W x The second removed Note applies to SR 3.2.1.2 and required multiplication of FQ (Z) by a factor and increased surveillance under certain conditions. In the improved methodology, the penalty factor is embedded in the methodology and a separate penalty factor is not applicable. x The deletion of these notes is evaluated in Section 4.4 of the NRC Final Safety Evaluation included in WCAP-17661-P-A.

Revision of Second Surveillance Frequency for SRs 3.2.1.1 and 3.2.1.2

x The time interval for completing the SRs is increased from 12 to 24 hours. x These changes are evaluated in Section 4.5 of the NRC Final Safety Evaluation included in WCAP-17661-P-A.

Deletion of Note in SR 3.2.1.2

x The deleted Note required increasing the Frequency to once per 7 effective full power days (EFPD) for certain conditions until the conditions are satisfied. In the new W methodology, the required penalty factor is part of the FQ (Z) formulation. x This change is evaluated in Section 4.6 of the NRC Final Safety Evaluation included in WCAP-17661-P-A. 

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Change in Frequency of SR 3.2.1.2 during Power Escalations

W x The Frequency is being changed to require FQ (Z) to be verified within the limits following each refueling within 24 hours after THERMAL POWER exceeds 75 percent RTP. x This change is evaluated in Section 4.7 of the NRC Final Safety Evaluation included in WCAP-17661-P-A.

Summary and Conclusions for TS 3.2.1 Changes

This proposed amendment resolves non-conservative NUREG-1431 TS 3.2.1 Required Actions identified via Westinghouse NSAL-09-5, Revision 1 and also resolves non-conservative NUREG-1431 TS 3.2.1 Surveillance Requirements identified via Westinghouse NSAL-15-1. The proposed amendment also revises TS 5.6.3.b to include WCAP-17661-P-A, Revision 1, as a COLR methodology reference.

The new FQ formulation will remove the surveillance sensitivity to the predicted axial power shapes and remove the potential non-conservatism in TS 3.2.1. Additional actions for the new Condition B Required Action Completion Times have also been proposed. The detailed proposed changes to SQN TS are provided in mark-up and retyped forms in Attachments 1 through 4 to this enclosure. The detailed changes to the SQN (Unit 1) TS Bases are provided for information in markup form in Attachment 5 to this enclosure.

3.2.4 TS 3.3.1 Reactor Trip System (RTS) Instrumentation Changes

Background

TS 3.3.1, “Reactor Trip System (RTS) Instrumentation” SR 3.3.1.3 and 3.3.1.6 are revised to implement BEACON core power distribution measurement consistent with WCAP-12472-P-A, and WCAP-12472-P-A, Addendum 4-A, and replace “incore detector” with “core power distribution” measurement. The proposed TS 3.3.1 changes will allow the use of a dedicated on-line core PDMS to enhance surveillance of core thermal limits. The PDMS to be used at SQN Units 1 and 2 is the NRC-approved Westinghouse proprietary core analysis system called BEACON.

Currently, SR 3.3.1.3 requires plant operators to compare the Nuclear Instrumentation System (NIS) excore neutron detectors channel output to the incore system AFD measurement by using movable incore detectors. SR 3.3.1.6 requires plant operators to calibrate excore channels to agree with the incore measurement system. The generic phrase “core power distribution” is substituted for “incore detector,” as this would allow the use of either a PDMS or the movable incore detectors to compare the results of the incore and NIS excore measurements.

Table 3.3.1-1 Note 1, “2YHUWHPSHUDWXUHǻ7´LVUHYLVHGWRLQFUHDVHWKH.DQG.FRHIILFLHQW YDOXHVLQWKH27ǻ7UHDFWor trip function .2 ZLOOEHLQFUHDVHGIURP•q)WR•qF; .3 will be increased from 0.00055/psig to 0.0008/psig) to protect the core thermal limits associated with this program. In addition, the Tƍ (nominal Tavg at RTP), Pƍ (nominal RCS RSHUDWLQJSUHVVXUH .-.FRHIILFLHQWVȫȫȫand ȫparameter values are relocated to the COLR consistent with TSTF-339-A, Rev. 2, and WCAP-14483-A. Table 3.3.1-1

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Evaluation of the Transition to Westinghouse RFA-2 Fuel

Note ³2YHUSRZHUǻ7´ is revised to relocate the TƎ (nominal Tavg at RTP), .-. coefficients, and ȫ3parameter values to the COLR consistent with TSTF-339-A, Rev. 2, and WCAP-14483-A.

Methodology

As described in WCAP-12472-P-A, the Westinghouse BEACON PDMS was developed to improve the operational support for pressurized water reactors (PWRs). BEACON is an advanced core monitoring and support package that utilizes existing plant instrumentation such as core exit thermocouple temperatures, reactor coolant system (RCS) cold leg temperatures, control bank positions, power range detector output, and reactor power level. These data are sent by the plant computer in the form of a file that BEACON can interpret to perform nodal power distribution prediction calculations. The PDMS does not provide any protection or control system function.

The BEACON-TSM (Technical Specification Monitor) system level was developed to provide licensees with the functionality needed to integrate BEACON into the plant TS for monitoring of current TS thermal power limits such as peak linear power density (FQ – TS 3.2.1, Heat N Flux Hot Channel Factor (FQ(Z))) and peak enthalpy rise (F ǻ+ – TS 3.2.2, Nuclear N Enthalpy Rise Hot Channel Factor (F ǻ+)). The application of WCAP-12472-P-A, and WCAP-12472-P-A, Addendum 4-A is discussed in detail in subsection 3.2.3 of this enclosure.

The NRC-approved setpoint methodology, WCAP-8745-P-A, “Design Bases for the Thermal Overpower ǻ7 and Thermal Overtemperature ǻ7 Trip Functions,” is included in the references to be added to TS 5.6.3 as discussed in subsection 3.2.8 of this enclosure. The .DQG.FRHIILFLHQWVLQWKH27ǻ7UHDFWRUWULSIXQFWLRQZHUHERWKLQFUHDVHGWRSURWHFWWKH core thermal limits associated with this program to account for uncertainty. The adequacy of WKH27ǻ7UHDFWRUWULSVHWSRLQWVZDVFRQILUPHGE\VKRZLQJWKDWWKH'1%GHVLJQEDVLVLVPHW in the analyses of those events that credit these functions for accident mitigation.

Refer to Attachment 8 for how the Limitations and Conditions were met for each of the NRC approved methodologies that were applied for the Sequoyah Units 1 and 2 fuel transition.

As discussed in the NRC Safety Evaluation for WCAP-14483-A, the justification is provided for why these parameter values may be relocated to the COLR. Cycle-specific TS parameters of Westinghouse plants have been approved by the NRC for inclusion in COLRs. The NRC has also extended this philosophy to the cycle-dependent OTǻ7 and OPǻ7 setpoint parameters and function modifiers. This allows these setpoints to be based on cycle-specific core design parameters, which are verified on a cycle-specific basis, thereby avoiding the necessity of overly conservative TS limits.

Results

NIS excore neutron detectors channel output can be compared to the incore measurement either through the PDMS or by using the movable incore detectors. SR 3.3.1.3 and 3.3.1.6 are revised to implement BEACON core power distribution measurement and replace using “incore detectors” with “core power distribution” measurement, consistent with WCAP-12472-P-A, and WCAP-12472-P-A, Addendum 4-A.

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7KH.DQG.FRHIILFLHQWvalues LQWKH27ǻ7UHDFWRUWULSIXQFWLRQDUHUHYLVHGDQGUHORFDWHG to the COLR along with other cycle-specific and cycle-FRQILUPHG27ǻ7DQG23¨7 parameter values consistent with TSTF-339-A, Rev. 2, and WCAP-14483-A.

Summary and Conclusions

The SR 3.3.1.3 and 3.3.1.6 changes are consistent with the changes from the application of WCAP-12472-P-A, and WCAP-12472-P-A, Addendum 4-A. Application of these NRC approved topical reports is discussed in detail in subsection 3.2.3 of this enclosure. Table 3.3.1-1RWH27ǻ7DQG1RWH23¨7 parameter values are relocated to the COLR.

3.2.5 TS 3.4.1 RCS Pressure, Temperature, and Flow Departure from Nucleate Boiling (DNB) Limits Changes

Background

The proposed change would revise TS 3.4.1, “RCS Pressure, Temperature, and Flow Departure from Nucleate Boiling (DNB) Limits,” to revise the specified RCS total flow rate, and relocate parameter values from LCO 3.4.1 and SRs 3.4.1.1 through 3.4.1.4 to the COLR, consistent with NRC approved TSTF-339-A, Rev. 2, and WCAP-14483-A.

The LCO 3.4.1, SR 3.4.1.3, and SR 3.4.1.4 RCS total flow rate is revised from ³•JSP´ WRWKH5&67KHUPDO'HVLJQ)ORZ 7') YDOXHRI³•JSPDQGJUHDWHUWKDQRUHTXDOWR the limit specified in the COLR.” The LCO 3.4.1 and SR 3.4.1.1 pressurizer pressure value is relocated to the COLR. The LCO 3.4.1 and SR 3.4.1.2 and RCS average temperature value is also relocated to the COLR.

Methodology

As discussed in the NRC SER for WCAP-14483-A, the justification is provided below for why these parameter values may be relocated to the COLR.

The TS limits on the DNB parameters assure that pressurizer pressure, RCS flow, and the RCS T-avg will be maintained within the limits of steady-state operation assumed in the accident analyses. These limits must be consistent with the initial full power conditions considered in the FSAR safety analysis for normal operation and anticipated operational occurrences (AOOs) in which precluding DNB is the primary criterion. The DNB parameter limits are also based on initial conditions assumed for accidents in which precluding DNB is not a criterion.

The minimum RCS total flow rate value currently specified in LCO 3.4.1 will be relocated to the COLR. In accordance with NRC approved WCAP-14483-A, the minimum limit for RCS flow (TDF) is proposed for inclusion in the LCO.

The justification for the minimum limit for RCS flow is contained within WCAP-14483-A and the associated NRC SER. The reason why there is a flow value in LCO 3.4.1 as well as a

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Evaluation of the Transition to Westinghouse RFA-2 Fuel reference to the COLR is explained below. The SER for WCAP-14483-A agreed with the Westinghouse Owners Group request to:

1. Revise TS 3.4.1 of NUREG-1431, RCS Pressure, Temperature, and Flow Departure from Nucleate Boiling (DNB) Limits, to relocate the pressurizer pressure, RCS average temperature (T-avg), and RCS total flow rate values to the COLR. The minimum limit for total flow based on that used in the reference safety analysis will be retained in the TS.

The reasoning behind the minimum limit remaining in the TS was discussed in the WCAP-14483-A SER:

Although some plants operate with lower steam generator tube plugging levels and thus higher RCS flow rates than those assumed in the safety analyses, a change in RCS flow is an indication of a physical change to the plant which should be reviewed by the NRC staff. Because of this, the staff recommended that if RCS flow rate were to be relocated to the COLR, the minimum limit for RCS total flow based on a staff approved analysis (e.g., maximum tube plugging) should be retained in the TS to assure that a lower flow rate than reviewed by the staff would not be used.

Because the lowest RCS flow rate used in any of the safety analyses is the Thermal Design Flow (TDF), the value for the ‘minimum limit for total flow’ which complies with the WCAP-14483-A SER requirement is the TDF value of 360,000 gpm.

Cycle-specific TS parameters of Westinghouse plants have been approved by the NRC for inclusion in COLRs. This allows the cycle-specific core design parameters to be verified on a cycle-specific basis, thereby avoiding the necessity of overly conservative TS limits.

Results

The pressurizer pressure value of “•2220 psia” in LCO 3.4.1 and SR 3.4.1.1 is relocated to the COLR, and replaced with “greater than or equal to the limit specified in the COLR.”

The RCS average temperature value “”583°F” in LCO 3.4.1 and SR 3.4.1.2 is relocated to the COLR, and replaced with “less than or equal to the limit specified in the COLR.”

The RCS total flow rate is revised from “•378,400 JSP´WR³•360,000 gpm and greater than or equal to the limit specified in the COLR” in LCO 3.4.1, SR 3.4.1.3, and SR 3.4.1.4.

These changes are not required to support the SQN transition to Westinghouse fuel; rather, it is an opportunity to make TS 3.4.1 more consistent with NUREG-1431 and provide for more operational flexibility in the future.

Summary and Conclusions

The RCS total flow rate is revised, and the pressurizer pressure and RCS average temperature values are relocated to the COLR with other cycle-confirmed parameter values.

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3.2.6 TS 4.2.1 Fuel Assemblies Changes

Background

This proposed license amendment (Enclosure 1) would modify the SQN Units 1 and 2 Technical Specifications (TS) 4.2.1, “Fuel Assemblies,” and 5.6.3, “Core Operating Limits Report,” to allow the use of Optimized ZIRLO as an approved fuel rod cladding material. The change would revise TS 4.2.1 to add Optimized ZIRLO as a fuel assembly cladding material in accordance with WCAP-12610-P-A & CENPD-404-P-A, Addendum 1-A (Proprietary) “Optimized ZIRLO” (Reference 16). The proposed change to TS 4.2.1 would also delete the discussion of Framatome report BAW-2328 consistent with the proposed implementation of Westinghouse core safety analysis methodologies, which are discussed in subsection 3.2.8 of this enclosure. Also, as mentioned earlier, Attachment 10 has been added to provide a summary of the revised safety analysis impact to the UFSAR.

In support of this license amendment request, Enclosure 5 contains an exemption request in accordance with 10 CFR 50.12, “Specific exemptions,” from certain requirements of 10 CFR 50.46, “Acceptance criteria for emergency core cooling systems for light-water reactors,” DQG&)5$SSHQGL[.³ECCS Evaluation Models.” This exemption request relates solely to the specific type 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 is required because Optimized ZIRLO has a slightly different composition than Zircaloy or ZIRLO.

Optimized ZIRLO was developed to meet the needs of longer operating cycles with increased fuel discharge burnup and fuel duty. Fuel rod internal pressure (resulting from the increased fuel duty, use of integral fuel burnable absorbers, and corrosion and temperature feedback effects) has 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. Compared to ZIRLO, the lower tin content and microstructure difference of Optimized ZIRLO provides a reduced corrosion rate while maintaining the benefits of mechanical strength and resistance to accelerated corrosion from abnormal chemistry conditions.

TVA currently plans to install Optimized ZIRLO clad fuel rods as part of the fuel transition.

Methodology

Reference 16 provides the details and test results of Optimized ZIRLO compared to ZIRLO fuel rod cladding material. Reference 16 also contains the material properties to be used in various models and methodologies when analyzing Optimized ZIRLO fuel rod cladding. The NRC safety evaluation for Reference 16 contains ten limitations and conditions that are addressed in Attachment 8 to this enclosure.

Subsection 3.2.8 of this enclosure discusses the proposed changes to SQN Units 1 and 2 TS 5.6.3, “Core Operating Limits Report” which includes adding Westinghouse Electric Company LLC (Westinghouse) topical report WCAP-12610-P-A and CENPD-404-P-A, Addendum 1-A, “Optimized ZIRLO,” (Reference 16) to the list of analytical methods used to determine the core operating limits approved by the NRC.

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Lead test assemblies (LTAs) with fuel pellets made from highly enriched reprocessed uranium blended down with natural uranium were evaluated by BAW-2328, “Blended Uranium Lead Test Assembly Design Report,” July 1998. These LTAs will not be used in reload cores after the SQN Unit 1 and 2 transition to Westinghouse RFA-2 fuel.

Results

TS 4.2.1, “Fuel Assemblies,” is revised to add “Optimized ZIRLO”.

The following sentence is deleted from TS 4.2.1: “Sequoyah is authorized to place a limited number of lead test assemblies into the reactor as described in the Framatome-Cogema Fuels report BAW-2328, beginning with the Unit 1 Operating Cycle 12.”

Summary and Conclusions

TS 4.2.1 is revised to add Optimized ZIRLO as an approved fuel rod cladding material and the reference to Framatome report BAW-2328 is removed from TS 4.2.1.

3.2.7 TS 4.2.2 Control Rod Assemblies Changes

Background

TS 4.2.2 is revised to require 52 RCCAs with no full-length control rod assembly in core location H-08 for both SQN Units 1 and 2. This proposed change is discussed in Attachment 9 to this enclosure.

Summary and Conclusions

Based on the assessments summarized in Attachment 9, TVA has determined that the SQN reactor cores can be safely designed and operated for the life of the plant with 52 control rods.

3.2.8 TS 5.6.3 Core Operating Limits Report Changes

Background

TS 5.6.3.a, “Core Operating Limits Report,” is revised to add additional core operating limits for Limiting Conditions for Operation (LCOs) 2.1.1, 3.1.4, 3.1.8, 3.3.1, and 3.4.1. In addition, the existing LCO titles will be revised consistent with the proposed TS changes discussed above. TS 5.6.3.b is revised to change analytical methods used to determine the core operating limits from Framatome methods to Westinghouse core safety analysis methodology references. This includes the application of the FSLOCA EM to evaluate the peak cladding temperatures for SQN Units 1 and 2 large-break and small-break LOCAs (LBLOCA and SBLOCA).

The thermal limits on the Framatome HTP fuel ensure that DNB and fuel centerline melt (FCM) will not occur if DNB and FCM do not occur in the Westinghouse RFA-2 fuel. Therefore, SLs 2.1 do not contain explicit limits for the Framatome HTP fuel. In addition, keeping the Framatome HTP fuel within operating limits of previous HTP cores, and applying additional thermal limit restrictions on this fuel, ensures that the Westinghouse

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RFA-2 fuel will always be limiting and establishes core operating limits for the transition cores. While the Framatome HTP fuel remains within compliance with the Framatome methodologies listed in the current TS 5.6.3, these Framatome methods no longer establish core operating limits or PCT during a LOCA and have been removed.

Methodology

Eighteen Westinghouse topical reports represent the methodologies used to determine the values presented in the revised SQN Units 1 and 2 COLR template (Attachment 6).

WCAP-8745-P-$ PHWKRGRORJ\IRU27¨7DQG23¨75HDFWRU7ULS6\VWHPVHWSRLQWVLQ76

WCAP-9272-P-A (methodology for Shutdown Margin, Moderator Temperature Coefficient, Shutdown Bank Insertion Limit, Control Bank Insertion Limits, Axial Flux Difference, Heat Flux Hot Channel Factor, Nuclear Enthalpy Rise Hot Channel Factor, DNB Limits, Refueling Pool Boron Concentration)

WCAP-10216-P-A Revision 1A (methodology for Axial Flux Difference limits with Relaxed Axial Offset Control and Heat Flux Hot Channel Factor (W(z)) Surveillance Requirements for FQ)

WCAP-10444-P-A (methodology for Axial Flux Difference and Heat Flux Hot Channel Factor Limits)

WCAP-10444-P-A Addendum 2-A (methodology for Axial Flux Difference and Heat Flux Hot Channel Factor Limits)

WCAP-10965-P-A (methodology for Shutdown Margin, Moderator Temperature Coefficient, Shutdown Bank Insertion Limit, Control Bank Insertion Limits, Axial Flux Difference, Heat Flux Hot Channel Factor, Nuclear Enthalpy Rise Hot Channel Factor, Refueling Pool Boron Concentration)

WCAP-10965-P-A, Addendum 2-A, Revision 0 (methodology for Shutdown Margin, Moderator Temperature Coefficient, Shutdown Bank Insertion Limit, Control Bank Insertion Limits, Heat Flux Hot Channel Factor, Nuclear Enthalpy Rise Hot Channel Factor, Axial Flux Difference, TS 3.4.1 DNB Limits, Refueling Pool Boron Concentration)

WCAP-11397-P-A (methodology for Reactor Core Safety Limits, Nuclear Enthalpy Rise Hot Channel Factor, TS 3.4.1 DNB Limits)

WCAP-12610-P-A (methodology for Axial Flux Difference and Heat Flux Hot Channel Factor Limits)

WCAP-12610-P-A & CENPD-404-P-A, Addendum 1-A (methodology for Axial Flux Difference and Heat Flux Hot Channel Factor Limits)

WCAP-14565-P-A (methodology for DNB Safety Limit, Nuclear Enthalpy Rise Hot Channel Factor, and TS 3.4.1 DNB Limits)

WCAP-14565-P-A, Addendum 1-A, Revision 0 (methodology for DNB Safety Limit)

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WCAP-14565-P-A, Addendum 2-P-A, Revision 0 (methodology for DNB Safety Limit)

WCAP-15025-P-A (methodology for DNB Safety Limit and Nuclear Enthalpy Rise Hot Channel Factor)

WCAP-16045-P-A (methodology for Shutdown Margin, Moderator Temperature Coefficient, Shutdown Bank Insertion Limit, Control Bank Insertion Limits, Heat Flux Hot Channel Factor, Nuclear Enthalpy Rise Hot Channel Factor, Axial Flux Difference, TS 3.4.1 DNB Limits, Refueling Pool Boron Concentration)

WCAP-16045-P-A, Addendum 1-A (methodology for Moderator Temperature Coefficient)

N WCAP-16996-P-A, Revision 1 (methodology for FQ and F ¨H limits)

WCAP-17661-P-A, Revision 1 (methodology for control bank insertion limits, FQ limits, and AFD limits)

Many of the methodology topical reports being added to TS 5.6.3.b are discussed elsewhere in this amendment request and listed below.

WCAP-8745-P-A (see subsection 3.2.4) WCAP-9272-P-A (see subsection 3.2.1) WCAP-11397-P-A (see subsection 3.2.1) WCAP-12610-P-A & CENPD-404-P-A, Addendum 1-A (see subsection 3.2.6) WCAP-14565-P-A and Addendum 1-A and Addendum 2-A (see subsection 3.2.1) WCAP-15025-P-A (see subsection 3.2.1) WCAP-16996-P-A Revision 1 (see Enclosures 2 and 3) WCAP-17661-P-A, Revision 1 (see subsection 3.2.3)

Refer to Attachment 8 for how Limitations and Conditions were met for each of these core safety analysis methodology references.

Redistribution of flow in pressurized water reactor cores is a well-documented and modeled phenomenon that occurs generally because of differences in hydraulic resistance, i.e., the differences in mixing vane grid loss coefficients between the two fuel types. In a mixed core, with assemblies having different overall hydraulic resistance, the local hydraulic resistance differences are also a mechanism for flow redistribution. This redistribution results in the fluid velocity vector having a lateral component as well as the dominant axial component. The lateral component is commonly referred to as crossflow. The crossflow induced by local hydraulic resistance differences will typically impact the mechanical design of the fuel assemblies, as well as the safety analysis of the core.

In safety analyses, crossflow affects DNB because the flow redistribution affects both mass velocity and enthalpy distributions. With the current DNB correlations that will be licensed for use at Sequoyah, WRB-2M and ABB-NV, the flow redistribution affects the prediction of minimum DNBR. As such, the design procedure for the DNB analysis of a mixed core is based on the principle that once the transition core DNBR penalty is determined, all further plant-specific analyses may proceed as if it were a full core of one fuel type.

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Transition cores are analyzed as if they were full cores of one assembly type by applying the applicable transition core DNBR penalties. Transition core DNBR penalties are calculated according to the methodology documented in WCAP-11837-P-A (Reference 28). It is noted that with the exception of the inlet group, the fuel assembly loss coefficient and the section/grid loss coefficients for the Westinghouse 17x17 RFA-2 fuel (w/IFMs) are lower than that of the Framatome HTP fuel. It is therefore expected that there will be a transition core penalty levied against the Westinghouse fuel for bottom-skewed shapes, but not for double-humped or top-skewed shapes. The penalties on the 17x17 RFA-2 fuel are calculated with the VIPRE-W code (Reference 20).

Typically, transition core penalties are reported as a function of the percentage of each fuel type in the core, as approved in Reference 28. However, for the Sequoyah reload transition safety analysis, it was determined that a bounding transition core penalty would be reported for the 17x17 RFA-2 fuel, for separate use with the WRB-2M and ABB-NV correlations.

The transition core DNBR penalty for the Sequoyah reload transition safety analysis is based on a comparison of the DNBR results obtained by modeling two different configurations of 3x3 fuel assembly arrays. One model represents a uniform array of Westinghouse 17x17 RFA-2 fuel assemblies (w/IFMs) and the other model represents a mixed array of the Westinghouse and Framatome fuel types, i.e., one Westinghouse assembly surrounded by eight Framatome assemblies.

The VIPRE-W models employ the WRB-2M DNB correlation for at-power events and for analyses applicable to the region above the first mixing vane grid. The WRB-2M correlation is applicable for pressures ranging from 1495 psia to 2425 psia, and for a local quality ranging from -0.10 to 0.29. For the rod withdrawal from subcritical (RWFS) (below the first mixing vane grid) and hot zero power (HZP) steam line break (SLB) events and any other analyses/conditions where the WRB-2M correlation is not applicable, the W-3 or the W-3 alternative correlations are employed. The ABB-NV correlation is applicable for pressures UDQJLQJIURPWRSVLDDQGIRUTXDOLW\”+=36/%FDVHVZLOl be evaluated using the WLOP CHF correlation. The WLOP correlation is applicable for pressures ranging from 185 SVLWRSVLDQGIRUDTXDOLW\”

The transition core DNBR penalties that are reported in subsection 3.2.9 are only applicable to Westinghouse 17x17 RFA-2 fuel; they are expected to bound the safety analyses for reload evaluations and for anticipated Chapter 15 events. For conservatism, the design limit transition core penalty has been rounded up by >10.0 percent from the transition core penalty that was obtained from the mixed core analysis. The DNBR results were computed within the respective correlation limits for quality and pressure. Sufficient available DNBR margin to cover the cycle-specific transition core penalties for each fuel type will be demonstrated on a cycle-specific basis.

A separate calculation was performed with the VIPRE-W code to analyze the impact of the transition core effect on the Framatome HTP fuel. The same methodology and process that was used on the RFA-2 assemblies described above was applied to the HTP fuel. The WRB-1 correlation was used in the HTP transition core evaluation, although it is not directly licensed for use with the HTP fuel. The WRB-1 correlation was used to show the general impact of a transition core scenario on the HTP fuel, as it is an older more conservative correlation compared to the WRB-2M and newer correlations, and is applicable over the full range of plant

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conditions. The main focus on the transition core evaluation for the HTP fuel was quantifying the flow loss present during a transition core scenario with the VIPRE-W code.

The transition core DNBR penalty for the Sequoyah reload transition safety analysis is based on a comparison of the DNBR results obtained by modeling two different configurations of 3x3 fuel assembly arrays. One model represents a uniform array of Framatome 17x17 HTP fuel assemblies and the other model represents a mixed array of the Westinghouse and Framatome fuel types, i.e., one HTP assembly surrounded by eight RFA-2 assemblies.

The maximum calculated transition core DNB penalty on the Framatome HTP fuel was 2.14 percent in a mixed core scenario with the WRB-1 correlation. The total flow reduction in the limiting HTP assembly through the top of the heated length was approximately 1.64 percent. Another 7.30 percent flow left the limiting HTP assembly above the heated length, for a total of 8.94 percent flow reduction. The 7.30 percent flow loss after the heated length of the fuel will have little impact on the CHF calculations. Therefore, this flow reduction’s impact on CHF and '1%ZLOOEHRIIVHWE\WKHSHUFHQW)ǻ+UHGXFWLRQDSSOLHGWRWKH+73IXHOGXULQJWKHWUDQVLWLRQ core cycles. $FDVHZDVUXQZLWKWKH+73IXHODWWKHUHGXFHG)ǻ+YDOXHLQD[matrix surrounded by RFA-2 fuel and resulted in a DNB increase from the full core case due to the UHGXFHG)ǻ+YDOXHVKRZLQJWKDWWKHSHUFHQW)ǻ+UHGXFWLRQRIIVHWVWKHWUDQVLWLRQFRUH'1% effect.

As an additional note, Westinghouse methods address the loss of the Leading Edge Flow Meter (LEFM) through administrative procedures. The uncertainty associated with the LEFM is 0.7% of 3455 MWt and the uncertainty associated with the feedwater venturis is 2% of 3411 MW. Upon loss of the LEFM, operation may continue at the uprated thermal power of 3455 MWt while continuing to use the power indications from the Nuclear Instrumentation System (NIS) power range channels. If the LEFM has not been returned to service prior to the required 12-hour NIS output adjustment (SR 3.3.1.2), then the reactor power must be administratively restricted to 98.7 percent of 3455 MWt (3411 MWt) and operated at a reduced power level until the LEFM is brought back into service to allow for the 2% venturi-based power measurement uncertainty. Consistent with the approach used at plants with Westinghouse fuel, this measure precludes the need for adjustment of the COLR limits to maintain the validity of the safety analyses).

Results

Attachment 6 presents the revised SQN Units 1 and 2 COLR template. Eighteen Westinghouse topical report references represent the methodologies used to determine the values presented in Attachment 6. The previous B&W, Areva, or Framatome methods are not needed to justify the transition to Westinghouse RFA-2 fuel. Where necessary, transition core penalties or N conservative operational limits are set for the RFA-2 vs. HTP fuel (e.g., a 5 percent F ǻ+ reduction (from 1.70 to 1.61) will be applied to the Framatome HTP fuel during the transition core cycles, a minimal (<1.0%) transition core DNBR penalty will be applied to the RFA-2 fuel while co-resident HTP fuel is loaded, the surveillance FQ limit for all fuel will be set at 2.62 in order to maintain a single FQ surveillance limit consistent with the current limit for Framatome HTP fuel, and a transition core PCT penalty of 23°F for Framatome HTP fuel resulting from a hydraulic mismatch during transition cycles to Westinghouse RFA-2 fuel).

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Summary and Conclusions

The analytical methods used to determine the core operating limits have been previously reviewed and approved by the NRC. This satisfies the stipulation in NRC Generic Letter 88-16 for relocating cycle-specific variables to the COLR. Attachment 8 goes into more detail on the application of these methodologies as well as others, such as PAD5, that aren’t specifically cited in the COLR.

3.2.9 Operating License Conditions 2.C (25) and 2.C (18) Changes

Background

The proposed change also revises the SQN Units 1 and 2 Operating License (OL) to replace OL condition 2.C(25) and 2.C(18) respectively, as a result of the implementation of Westinghouse core safety analysis methodology. Specifically, the following license condition is proposed.

When the Framatome HTP fuel assemblies are co-resident with the Westinghouse RFA-2 fuel assemblies the: N x HTP fuel assemblies F ǻ+ shall be maintained less than 1.61. x RFA-2 fuel assemblies the DNBR limit shall be reduced by: — 0.25% for the WRB-2M critical heat flux correlation — 0.50% for the ABB-NV critical heat flux correlation

Summary and Conclusions

Removal of the current license conditions is appropriate as the conditions were associated with a mixed core DNBR penalty resulting from the Framatome fuel conversion in 1997. The proposed license conditions are appropriate for the mixed cores until a homogeneous core of Westinghouse RFA-2 fuel exists. Additional information is provided above in subsection 3.2.8.

3.3 Conclusion

The proposed changes are needed to support the transition to Westinghouse RFA-2 fuel. The changes are based upon NRC approved methods and methodologies and with the exception of the application of WCAP-17661-P-A Revision 1, have received NRC approval for identical requested changes from other licensees.

Additionally, due to the application of a large number of Topical Reports for the fuel transition, Attachment 8 has been created to address SQN Units 1 and 2 compliance with the Limitations and Conditions stipulated in the NRC safety evaluation approving each of the Topical Reports, with one exception. The FSLOCA summary report (Enclosure 2 of this LAR) contains proprietary information, including the proprietary disposition to the Limitations and Conditions contained in the NRC safety evaluation approving WCAP-16996-P-A, Revision 1, “Realistic LOCA Evaluation Methodology Applied to the Full Spectrum of Break Sizes (FULL SPECTRUM LOCA Methodology),” November 2016.

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4.0 REGULATORY EVALUATION

4.1 Applicable Regulatory Requirements/Criteria

4.1.1 Regulations

Section 182a of the Atomic Energy Act requires applicants for operating licenses to include Technical Specifications (TSs) as part of the license. The TSs ensure the operational capability of structures, systems, and components that are required to protect the health and safety of the public. The U.S. Nuclear Regulatory Commission’s (NRC’s) requirements related to the content of the TSs are contained in Section 50.36 of Title 10 of the Code of Federal Regulations (10 CFR 50.36) which requires that the TSs include items in the following specific categories: (1) safety limits, limiting safety systems settings, and limiting control settings; (2) limiting conditions for operation; (3) surveillance requirements per 10 CFR 50.36(c)(3); (4) design features; and (5) administrative controls.

This amendment request involves each of the five categories in 10 CFR 50.36(c)(1) through 10 CFR 50.36(c)(5).

10 CFR 50.46 requires, in part, that each boiling or pressurized light-water nuclear power reactor fueled with uranium oxide pellets within cylindrical Zircaloy or ZIRLO cladding must be provided with an emergency core cooling system (ECCS) that must be designed so that its calculated cooling performance following postulated loss-of-coolant accidents conforms to the criteria set forth in 10 CFR 50.46(b). $SSHQGL[.WR 10 CFR Part 50 establishes the regulations for conservative ECCS evaluation models. Enclosure 5 contains an exemption UHTXHVWIURP&)5DQG$SSHQGL[.WR&)53DUW, in accordance with 10 CFR 50.12. In Reference 16, the NRC approved Addendum 1-A to WCAP-12610-P-A and CENPD-404-P-A for the use of Optimized ZIRLO as an acceptable fuel rod cladding material for Westinghouse fuel designs.

TS 4.2.2, “Control Rod Assemblies,” describes a Design Feature required per 10 CFR 50.36(c)(4). The proposed change does not eliminate the design feature requiring control rod assemblies. Rather, it allows for a revised number of control rod assemblies.

TS 3.1.4, “Rod Group Alignment Limits,” requires all shutdown and control rods to be operable. Because the control rod in location H-08 would be permanently removed under the proposed change, this TS requirement would not be applicable to that control rod position. As such, no changes to TS 3.1.4 are required.

The requirements of 10 CFR 50.62(c) concerning an alternate rod injection system were also assessed.

Removal of Control Rod H-08 does not impact either the reactor protection system or ATWS Mitigation System Actuation Circuitry because the trip reactivity remains bounding. The changes to other parameters described in the license amendment request do not impact the ATWS analysis. The all-rods-out moderator temperature coefficient (MTC) is not impacted by removal of Control Rod H-08. Therefore, the requirements of 10 CFR 50.62(c)(1) continue to be met and there is no impact to the ATWS analysis.

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The requirements of 10 CFR 50.62(c)(2) are not applicable because SQN is a Westinghouse pressurized water reactor. Also, 10 CFR 50.62(c)(3), (4), and (5) are applicable to boiling water reactors and therefore not applicable to SQN.

4.1.2 General Design Criteria

As noted in the SQN UFSAR Section 3.1.2, the Sequoyah Nuclear Plant was designed to meet the intent of the Proposed General Design Criteria for Nuclear Power Plant Construction Permits published in July, 1967. The Sequoyah construction permit was issued in May, 1970. This UFSAR, however, addresses the NRC General Design Criteria (GDC) published as Appendix A to 10 CFR 50 in July 1971.

The SQN UFSAR contains the following relevant GDCs. Compliance with these GDCs is described in Section 3.1.2 of the SQN UFSAR.

Criterion 4 – Environmental and Missile Design Bases Structures, systems, and components important to safety are designed to accommodate the effects of and to be compatible with the environmental conditions associated with normal operation, maintenance, testing, and postulated accidents, including LOCA. These structures, systems and components shall be appropriately protected against dynamic effects, including the effects of missiles, pipe whipping, and discharging fluids, that may result from equipment failures and from events and conditions outside the nuclear power unit.

Criterion 10 – Reactor Design The reactor core and associated coolant, control, and protection systems shall be designed with appropriate margin to assure that specified acceptable fuel design limits are not exceeded during any condition of normal operation, including the effects of anticipated operational occurrences.

Criterion 11 – Reactor Inherent Protection The reactor core and associated coolant systems shall be designed so that in the power operating range the net effect of the prompt inherent nuclear feedback characteristics tends to compensate for a rapid increase in reactivity.

Criterion 12 – Suppression of Reactor Power Oscillations The reactor core and associated coolant, or, control and protection systems shall be designed to assure that power oscillations which can result in conditions exceeding specified acceptable fuel design limits are not possible or can be reliably and readily detected and suppressed.

Criterion 20 -- Protection System Functions The protection system shall be designed (1) to initiate automatically the operation of appropriate systems including the reactivity control systems, to assure that specified acceptable fuel design limits are not exceeded as a result of anticipated operational occurrences and (2) to sense accident conditions and to initiate the operation of systems and components important to safety.

Criterion 23 – Protection System Failure Modes The Protection System shall be designed to fail into a safe state or into a state demonstrated to be acceptable on some other defined basis if conditions such as disconnection of the

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Criterion 25 – Protection System Requirements for Reactivity Control Malfunctions The Protection System shall be designed to assure that specified acceptable fuel design limits are not exceeded for any single malfunction of the Reactivity Control Systems, such as accidental withdrawal (not ejection or dropout) of control rods.

Criterion 26 – Reactivity Control System Redundance and Capability Two independent reactivity control systems of different design principles shall be provided. One of the systems shall use control rods, preferably including a positive means for inserting the rods, and shall be capable of reliably controlling reactivity changes to assure that under conditions of normal operation, including anticipated operational occurrences, and with appropriate margin for malfunctions such as stuck rods, specified acceptable fuel design limits are not exceeded. The second reactivity control system shall be capable of reliably controlling the rate of reactivity changes resulting from planned, normal power changes (including xenon burnout) to assure acceptable fuel design limits are not exceeded. One of the systems shall be capable of holding the reactor core subcritical under cold conditions.

Criterion 27 – Combined Reactivity Control Systems Capability The Reactivity Control Systems shall be designed to have a combined capability, in conjunction with poison addition by the Emergency Core Cooling System (ECCS), of reliably controlling reactivity changes to assure that under postulated accident conditions and with appropriate margin for stuck rods the capability to cool the core is maintained.

Criterion 28 – Reactivity Limits The Reactivity Control Systems shall be designed with appropriate limits on the potential amount and rate of reactivity increase to assure that the effects of postulated reactivity accidents can neither (1) result in damage to the reactor coolant pressure boundary greater than limited local yielding nor (2) sufficiently disturb the core, its support structures or other reactor pressure vessel internals to impair significantly the capability to cool the core. These postulated reactivity accidents shall include consideration of rod ejection (unless prevented by positive means), rod dropout, steam line rupture, changes in reactor coolant temperature and pressure, and cold water addition.

Criterion 29 – Protection against Anticipated Operational Occurrences The Protection and Reactivity Control Systems shall be designed to assure an extremely high probability of accomplishing their safety functions in the event of anticipated operational occurrences.

Criterion 35 – Emergency Core Cooling A system to provide abundant emergency core cooling shall be provided. The system safety function shall be to transfer heat from the reactor core following any loss of reactor coolant at a rate such that (1) fuel and clad damage that could interfere with continued effective core cooling is prevented and (2) clad metal-water reaction is limited to negligible amounts.

Suitable redundancy in components and features, and suitable interconnections, leak detection, isolation, and containment capabilities shall be provided to assure that for onsite electric power system operation (assuming offsite power is not available) and for offsite

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electric power system operation (assuming onsite power is not available) the system safety function can be accomplished, assuming a single failure.

With the implementation of the proposed changes, SQN Units 1 and 2 continue to meet the applicable regulations and requirements, subject to the previously approved exceptions.

4.1.3 Regulatory Guidance and Miscellaneous References

NRC Generic Letter (GL) 88-16

GL 88-16, “Removal of Cycle-Specific, Parameter Limits from Technical Specifications,” dated October 4, 1988, provides that it is acceptable for licensees to control reactor physics parameter limits by specifying an NRC-approved calculation methodology. These parameter limits may be removed from the TS and placed in a cycle-specific COLR that is required to be submitted to the NRC every operating cycle or each time it is revised. Consistent with the guidance in NRC GL 88-16, SQN Units 1 and 2 TS 5.6.3, “Core Operating Limits Report (COLR)” requires the following.

x The analytical methods used to determine the core operating limits shall be those previously reviewed and approved by the NRC. x The COLR, including any mid-cycle revisions or supplements, is to be provided upon issuance for each reload cycle to the NRC. x The TS include a list of references of the NRC-approved methodologies that are used to determine the cycle-specific core operating limits. TS 5.6.3 identifies the NRC-approved analytical methodologies that are used to determine the core operating limits for SQN Units 1 and 2.

Upon approval of the proposed LAR, the guidance in GL 88-16 continues to be met because the proposed change will continue to specify the NRC-approved methodologies used to determine the core operating limits open and therefore provide input to the associated RTS channel.

Standard Review Plan NUREG-0800, “Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants: LWR Edition” (SRP), Section 4.2, “Fuel System Design,” provides regulatory guidance to the NRC staff for the review of fuel rod cladding materials and fuel system. According to SRP Section 4.2, the fuel system safety review provides assurance as follows. x The fuel system is not damaged as a result of normal operation and anticipated operational occurrences (AOOs). x Fuel system damage is never so severe as to prevent control rod insertion when it is required. x The number of fuel rod failures is not underestimated for postulated accidents. x Coolability is always maintained.

Upon approval of the proposed LAR, the guidance in SRP 4.2 continues to be met because the proposed change will continue to comply with the NRC-approved design standards discussed in Section 3.1 of this enclosure.

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Regulatory Guide (RG) 1.236 RG 1.236 Revision 0, “Pressurized-Water Reactor Control Rod Ejection and Boiling-Water Reactor Control Rod Drop Accidents,” was reviewed for impact on this LAR. The results of this review are discussed in footnote 1 to the table in Attachment 10 to this enclosure. No unacceptable impact was found during this review.

Conclusion

There are no changes being proposed in this amendment application such that commitments to the regulations and regulatory guidance documents above would come into question. The evaluations documented above confirm that Sequoyah Units 1 and 2 will continue to comply with all applicable regulatory requirements.

4.2 Precedent

The following precedents are related to the proposed TS change in this submittal.

FSLOCA Relative to FSLOCA, this LAR is similar to one approved by the NRC for the Diablo Canyon Nuclear Power Plant (ML19316A109), which revised Diablo Canyon TS 5.6.5b, “Core Operating Limits Report (COLR),” to replace the existing LOCA methodologies with the NRC-approved LOCA methodology contained in WCAP-16996-P-A, Revision 1.

Use of Optimized ZIRLO Relative to the use of Optimized ZIRLO, this LAR is similar in nature to the following LARs and exemption requests approved by the NRC that authorized the use of Optimized ZIRLO fuel rod cladding: x Beaver Valley , Units 1 and 2 (ML18022B116 and ML17313A550) x Palo Verde Nuclear Generating Station, Units 1, 2, and 3 (ML17319A214 and ML17319A107) x Wolf Creek Generating Station (ML16179A293 and ML16179A440)

TVA also reviewed the related RAI responses associated with the Palo Verde Nuclear Generating Station, Units 1, 2, and 3 LAR (ML17153A373) and the Wolf Creek Generating Station LAR (ML16161A509) and incorporated the requested information as appropriate.

Removal of RCCA at location H-08 The changes proposed in this LAR for permanent operation of SQN-1 and SQN-2 with no RCCA in core location H-08 is similar to one approved by NRC for South Texas Project, Unit 1, in LA No. 211 issued on December 21, 2016 (ML16319A010).

COLR Parameter Relocation The changes proposed in this LAR for relocating RCS-related cycle specific parameters are consistent with similar changes approved by the NRC for other nuclear power plants. These include changes approved for the following. x Braidwood Station, Units 1. and 2, and Byron Station, Units 1 and 2, by License Amendment (LA) Nos. 106 and 113, respectively, issued on May 15, 2000 (ML003717646) x Wolf Creek Generating Station by LA No. 144, issued on March 28, 2002 (ML020180190)

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x , Units 1 and 2 by LA Nos. 210 and 204, respectively, issued on December 19, 2003 (ML033570127) x McGuire Nuclear Station, Units 1 and 2 by LA Nos. 219 and 201, respectively, issued on January 14, 2004 (ML040140090) x Millstone Power Station, Unit No. 3 by LA No. 218 issued on March 9, 2004 (ML033450435) x Indian Point Nuclear Generating Unit No. 3 by LA No. 225, issued on March 24, 2005 (ML050600380).

BEACON Relative to the use of BEACON, this LAR is similar to one approved by NRC for Watts Bar Unit 1 in LA No. 82, issued on October 27, 2009 (ML092710381)

4.3 No Significant Hazards Consideration

The Tennessee Valley Authority (TVA) is proposing an amendment to revise the Sequoyah Nuclear Plant (SQN) Units 1 and 2 Technical Specifications (TSs) as follows.

The proposed change would revise SQN Units 1 and 2 Technical Specification (TS) 5.6.3, “Core Operating Limits Report,” to replace the loss-of-coolant accident (LOCA) analysis evaluation model references with reference to the FULL SPECTRUM Loss-of-Coolant Accident (FSLOCA) Evaluation Model analysis applicable to both SQN Unit 1 and Unit 2 with replacement steam generators.

TVA is applying the FSLOCA Evaluation Model to determine the peak cladding temperatures for LBLOCA and SBLOCA. The use of the FSLOCA Evaluation Model results in a reduction in the peak cladding temperature in analyses of LBLOCA and SBLOCA. The safety analysis process for each reload design will continue to demonstrate that all regulatory criteria are met.

TVA is applying topical report WCAP-17661-P-A, Revision 1, which corrects a non-conservatism in the Standard Technical Specifications for Westinghouse PWRs (NUREG-1431). Specifically, the proposed change revises TS 3.2.1 Conditions and Surveillance Requirements to eliminate non-conservatisms described in NSAL-09-5 Revision 1 and NSAL-15-1. The proposed change also revises TS 5.6.3 to include WCAP-17661-P-A, Revision 1, as a reference. STS 3.2.1 from NUREG-1431 is adopted in areas not specifically revised by WCAP-17661-P-A Revision 1. Deviations to the TS 3.2.1 Condition B Completion Times in WCAP-17661-P-A Revision 1 are also proposed.

TS 3.2.2, “Nuclear Enthalpy Rise Hot Channel Factor Fǻ+(X,Y),” is revised to reflect TS 3.2.2, N “Nuclear Enthalpy Rise Hot Channel Factor (F 'H),” in NUREG-1431. Adopting the latest version of the NRC-approved Standard Technical Specification 3.2.2 essentially returns the

Sequoyah Units 1 and 2 Technical Specifications to their licensing basis for the F¨H LCO prior to the conversion from Westinghouse fuel to Framatome Cogema Fuel, except for two Completion Times (CTs).

This proposed license amendment would modify the SQN Units 1 and 2 Technical Specifications (TS) 4.2.1, “Fuel Assemblies,” and 5.6.3, “Core Operating Limits Report,” to allow the use of Optimized ZIRLO as an approved fuel rod cladding material. The change would revise TS 4.2.1 to add Optimized ZIRLO as a fuel assembly cladding material in accordance with WCAP-12610-P-A & CENPD-404-P-A, Addendum 1-A (Proprietary), “Optimized ZIRLO”

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(Reference 16). The proposed change to TS 4.2.1 would also delete the discussion of Framatome report BAW-2328 consistent with the proposed implementation of Westinghouse core safety analysis methodologies.

TS 4.2.2 is revised to require 52 RCCAs with no full-length control rod assembly in core location H-08 for both Units 1 and 2.

The proposed changes will relocate cycle-specific parameter limits from TSs 2.1.1, 3.3.1, and 3.4.1 to the CORE OPERATING LIMITS REPORT (COLR). The proposed changes to TS 2.1.1, “Reactor Core Safety Limits,” will relocate the revised Reactor Core Safety Limits figure to the COLR and add new Safety Limits for departure from nucleate boiling ratio (DNBR) and peak fuel centerline temperature. The proposed changes to TS Table 3.3.1-1, “Reactor Trip System Instrumentation,” will relocate the Overtemperature ¨T and Overpower ¨T setpoint parameters (nominal RCS average temperature, nominal RCS operating pressure, .YDOXHVand dynamic compensation time constants (IJ values) to the COLR. The proposed changes to TS 3.4.1, “RCS Pressure, Temperature, and Flow Departure from Nucleate Boiling (DNB) Limits,” will relocate the pressurizer pressure and RCS average temperature values to the COLR and revise the thermal design flow rate. TS 5.6.3, “CORE OPERATING LIMITS REPORT (COLR),” will be revised to add several topical reports and allow all cited topical reports to be identified by title and number only.

The proposed changes to the TSs also involve allowing the use of the Best Estimate Analyzer for Core Operations Nuclear (BEACON) Power Distribution Monitoring System (PDMS) to perform core power distribution surveillances. The proposed changes allow for the power distribution surveillances to be performed by PDMS rather than using the Movable Incore Detector (MID) System. In addition, a RAOC-type axial flux distribution methodology is planned to be implemented along with the proposed implementation of PDMS. The proposed TS changes for PDMS and RAOC are supported by the NRC approved methodologies. All reload specific input will be confirmed via an approved reload methodology employed by TVA and Westinghouse.

TVA has evaluated whether or not a significant hazards consideration is involved with the proposed amendment by focusing on the three standards set forth in 10 CFR 50.92, “Issuance of amendment,” as discussed below:

1. Does the proposed amendment involve a significant increase in the probability or consequences of an accident previously evaluated?

Response: No

The proposed change to SQN Units 1 and 2 TS 5.6.3, “Core Operating Limits Report,” to replace the LOCA analysis evaluation model references with the FSLOCA Evaluation Model analysis applicable to both SQN Unit 1 and Unit 2 with replacement steam generators. These changes implement a Nuclear Regulatory Commission (NRC) approved LOCA evaluation model. The analysis results for SQN Units 1 and 2, based on using the new evaluation model, meet the regulatory requirements of 10 CFR 50.46. The use of a new NRC-approved LOCA evaluation model will not increase the potential for an accident. Therefore, the possibility of an accident is not increased by the proposed changes. Because the reactor core meets the regulatory requirements of 10 CFR 50.46 after a

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postulated LOCA, the consequences of an accident are not increased by the proposed changes.

The proposed amendment will allow the use of Optimized ZIRLO clad nuclear fuel at SQN Units 1 and 2. The NRC approved topical report WCAP-12610-P-A and CENPD-404-P-A, Addendum 1-A, which addresses Optimized ZIRLO fuel rod cladding and demonstrates that Optimized ZIRLO fuel rod cladding has essentially the same properties as ZIRLO fuel rod cladding. The use of Optimized ZIRLO fuel rod cladding material will not result in adverse changes to the operation or configuration of the facility. The fuel cladding itself is not an accident initiator and does not affect accident probability. Use of Optimized ZIRLO meets the fuel design acceptance criteria and hence does not significantly affect the consequences of an accident.

The proposed changes described in WCAP-17661, Revision 1, resolve non-conservative TS Required Actions identified via Westinghouse NSAL-09-5, Revision 1. The proposed changes also resolve non-conservative TS Surveillance Requirements identified via Westinghouse NSAL-15-1. Operation in accordance with the revised TS ensures that the assumptions for initial conditions of key parameter values in the safety analyses remain valid and does not result in actions that would increase the probability or consequences of any accident previously evaluated.

TVA has performed a multi-cycle assessment on SQN reactor cores. Operation of SQN with the H-08 control rod removed will not involve a significant increase in the probability or consequences of an accident previously evaluated. Shutdown Margin (SDM) is reduced by the absence of the H-08 control rod, but remains bounded by the limits specified by the COLR. Because the impacts on the cycle-specific nuclear design parameters are bounded by the conservative input values used in the fuel transition accident analyses.

Overall protection system performance will remain within the bounds of the previously performed accident analyses since there are no design changes. The design of the reactor trip system (RTS) instrumentation and engineered safety feature actuation system (ESFAS) instrumentation will be unaffected and these protection systems will continue to function in a manner consistent with the plant design basis. All design, material, and construction standards that were applicable prior to this amendment request will be maintained.

The proposed changes will not adversely affect accident initiators or precursors nor alter the design assumptions, conditions, and configuration of the facility or the manner in which the plant is operated and maintained. The proposed changes will not alter or prevent the ability of structures, systems, and components (SSCs) from performing their intended functions to mitigate the consequences of an initiating event within the assumed acceptance limits. Accidents/events were analyzed/evaluated using approved methods and codes. Results were within established acceptance criteria, and the plant’s assumed source term remains bounding; therefore, there’s no increase in consequences.

These changes do not physically alter safety-related systems nor affect the way in which safety-related systems perform their functions. Additional Safety Limits on the DNB design basis and peak fuel centerline temperature are being imposed in TS 2.1.1, “Reactor Core Safety Limits,” and the Reactor Core Safety Limits figure is being relocated to the COLR. The additional Safety Limits are consistent with the values stated in the UFSAR. The proposed changes do not, by themselves, alter any of the relocated parameter limits. The

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removal of the cycle-specific parameter limits from the TS does not eliminate existing requirements to comply with the parameter limits. TS 5.6.3 ensures that the analytical methods used to determine the core operating limits meet NRC reviewed and approved methodologies. TS 5.6.3 ensures that applicable limits of the safety analyses are met.

Power Distribution Monitoring System (PDMS) performs continuous core power distribution monitoring. It in no way provides any protection or control system functionality. Fission product barriers are not impacted by these proposed changes. The proposed changes occurring with PDMS will not result in any additional challenges to plant equipment that could increase the probability of any previously evaluated accident. The changes associated with the PDMS do not affect plant systems such that their function in the control of radiological consequences is adversely affected. These proposed changes will therefore not affect the mitigation of the radiological consequences of any accident described in the Updated Final Safety Analysis Report (UFSAR).

Continuous on-line monitoring through the use of PDMS provides significantly more information about the power distributions present in the core than is currently available. This results in more time (i.e., earlier determination of an adverse condition developing) for operator action prior to having any adverse condition develop that could lead to an accident condition or to unfavorable initial conditions for an accident.

Therefore, 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

The proposed change to SQN Units 1 and 2 TS 5.6.3 to replace the LOCA analysis evaluation model references with the FSLOCA Evaluation Model. The use of this new analytical methodology will not create the possibility of a new or different kind of accident from any accident previously evaluated.

The use of Optimized ZIRLO fuel rod cladding material will not result in adverse changes to the operation or configuration of the facility. WCAP-12610-P-A and CENPD-404-P-A, Addendum 1-A demonstrated that the material properties of Optimized ZIRLO fuel rod cladding are similar to those of ZIRLO fuel rod cladding. Therefore, Optimized ZIRLO fuel rod cladding will perform similarly to ZIRLO fuel rod cladding, thus precluding the possibility of the fuel rod cladding becoming an accident initiator and causing a new or different kind of accident.

The proposed change to the adopted Westinghouse Standard TS (NUREG-1431) 3.2.1 and 3.2.2 does not involve a physical alteration of the plant (i.e., no new or different type of equipment will be installed). Operation in accordance with the revised TS and its limits precludes new challenges to systems, structures, or components that might introduce a new type of accident. Applicable design and performance criteria will continue to be met and no new single failure mechanisms will be created. The proposed change for resolution of Westinghouse NSAL-09-5, Revision 1 and NSAL-15-1 does not involve the alteration of plant equipment or introduce unique operational modes or accident precursors.

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Operation of SQN with the H-08 control rod removed will not create the possibility of a new or different kind of accident from any accident previously evaluated and the safety evaluations performed with the H-08 control rod removed validated that the impacts to the nuclear design parameters were within the bounds of those assumed in the fuel transition accident analyses. Additionally, by installing a flow restrictor in the H-08 upper internals control rod guide tube, the hydraulic characteristics of the reactor vessel upper internals are unchanged and all plant equipment will continue to meet applicable design and safety requirements.

Relocation of cycle-specific parameter limits has no influence on, nor does it contribute to, the possibility of a new or different kind of accident. The relocated cycle specific parameter limits will continue to be calculated using the NRC reviewed and approved methodologies. The proposed changes do not alter assumptions made in the safety analyses. Operation within the core operating limits will continue to be observed.

As stated previously, the implementation of the PDMS system has no influence or impact on plant operations or safety, nor does it contribute in any way to the probability or consequences of an accident. No safety-related equipment, safety function, or plant operation will be altered as a result of this proposed change. The possibility for a new or different type of accident from any accident previously evaluated is not created because the changes associated with PDMS do not result in a change to the design basis of any plant component or system. The evaluation of the effects of the PDMS changes shows that all design standards and applicable safety criteria limits are met. These changes, therefore, do not cause the initiation of any accident nor create any new failure mechanisms. All equipment important to safety will operate as designed. Component integrity is not challenged. The proposed changes do not result in any event previously deemed incredible being made credible. The PDMS changes will not result in more adverse conditions and will not result in any increase in the challenges to safety systems. The cycle specific variables required by the PDMS are calculated using NRC approved methods. The Technical Specifications (TS) will continue to require operation within the required core operating limits and appropriate actions will be taken when or if limits are exceeded.

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

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

Response: No

The proposed change to SQN Units 1 and 2 TS 5.6.3 to replace the LOCA analysis evaluation model references with the FSLOCA Evaluation Model. The analysis results for SQN Units 1 and 2, based on using the new evaluation model, meet the regulatory requirements of 10 CFR 50.46 with increased margin after a postulated LOCA.

WCAP-12610-P-A and CENPD-404-P-A, Addendum 1-A, demonstrated that the material properties of the Optimized ZIRLO fuel rod cladding are similar to those of ZIRLO fuel rod cladding. Optimized ZIRLO fuel rod cladding is expected to perform similarly to ZIRLO fuel rod cladding for normal operating and accident scenarios, including both loss-of-coolant

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accident (LOCA) and non-LOCA scenarios. The use of Optimized ZIRLO fuel rod cladding will not result in adverse changes to the operation or configuration of the facility.

Operation in accordance with the revised TS and its limits does not impact assumptions made in the safety analyses. This ensures that applicable design and performance criteria associated with the safety analysis will continue to be met and that the margin of safety is not affected. In addition, to address mixed core safety analysis impacts, a combination of PCT and DNB penalties has been imposed.

Operation of SQN with the H-08 control rod removed will not involve a significant reduction in a margin of safety. The margin of safety is established by setting safety limits and operating within those limits. The proposed change does not alter any design basis or safety limit and does not change any setpoint at which automatic actuations are initiated. The proposed change has been evaluated for effects on available shutdown margin, boron worth, trip reactivity as a function of time, and moderator temperature coefficient. The results of these evaluations show that the proposed change does not exceed or alter a design basis or safety limit.

For the relocated values, the proposed changes do not eliminate any surveillances or alter the frequency of surveillances required by the Technical Specifications. The nominal RTS and ESFAS trip setpoints will remain unchanged. None of the acceptance criteria for any accident analysis will be changed as a result of the relocated values. The development of cycle-specific parameter limits for future reload designs will continue to conform to NRC reviewed and approved methodologies, and will be performed pursuant to 10 CFR 50.59 to assure that plant operation remains within cycle-specific parameter limits.

The margin of safety is not affected by the implementation of PDMS. The margin of safety presently provided by current TS remains unchanged. Appropriate measures exist to control the values of these cycle-specific limits. The proposed changes continue to require operation within the core limits that are based on NRC approved reload design methodologies. The proposed changes continue to ensure that appropriate actions will be taken if limits are violated. These actions remain unchanged. The development of the reload specific limits, including RAOC bands, for future reloads will continue to conform to the methods described in WCAP-9272-P-A which includes a review to assure that operation of the units, within the cycle specific limits, will not involve a reduction in the margin of safety as defined in the basis for any Technical Specification.

Therefore, the proposed amendment does not involve a significant reduction in a margin of safety.

Based on the above, TVA concludes that the proposed amendment does not involve a significant hazards consideration under the standards set forth in 10 CFR 50.92 (c), and, accordingly, a finding of “no significant hazards consideration” is justified.

4.4 Conclusions

In conclusion, based on the considerations discussed above, (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commission's regulations,

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and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.

5.0 ENVIRONMENTAL CONSIDERATION

A review has determined that the proposed amendment would change a requirement with respect to installation or use of a facility component located within the restricted area, as defined in 10 CFR 20, or would change an inspection or surveillance requirement. However, the proposed amendment does not involve (i) a significant hazards consideration; (ii) a significant change in the types or significant increases in the amounts of any effluents that may be released offsite; or (iii) a significant increase in individual or cumulative occupational radiation exposure. Accordingly, the proposed amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9). Therefore, pursuant to 10 CFR 51.22(b), no environmental impact statement or environmental assessment needs to be prepared in connection with the issuance of the amendment.

6.0 REFERENCES

1. Westinghouse Report WCAP-10444-P-A, Addendum 2-A (Proprietary), “VANTAGE 5H FUEL ASSEMBLY,” February 1989.

2. Westinghouse Report WCAP-12488-A, Revision 0, “Westinghouse Fuel Criteria Evaluation Process,” October 1994.

3. Westinghouse Letter NSD-NRC-98-5796, “Fuel Criteria Evaluation Process Notification for the 17x17 Robust Fuel Assembly with IFM Grid Design,” October 13, 1998. (ML20154M323)

4. Letter from Henry A. Sepp (Westinghouse) to J. S. Wermiel (U.S. NRC), LTR-NRC-01-44, “Fuel Criterion Evaluation Process (FCEP) Notification of the RFA-2 Design (Proprietary),” December 19, 2001.

5. Letter from Henry A. Sepp (Westinghouse) to J. S. Wermiel (U.S. NRC), LTR-NRC-02-55, “Fuel Criterion Evaluation Process (FCEP) Notification of the RFA-2 Design, Revision 1 (Proprietary),” November 13, 2002. (ML023190181)

6. WCAP-11397-P-A (Proprietary), “Revised Thermal Design Procedure,” April 1989.

7. TSTF-339-A, Revision 2, “Relocate TS Parameters to COLR,” June 2000. (ML003723269)

8. WCAP-14483-A, “Generic Methodology for Expanded Core Operating Limits Report,” January 1999.

9. NUREG-1431, Revision 4, “Standard Technical Specifications Westinghouse Plants,” November 2011.

10. WCAP-15025-P-A (Proprietary), “Modified WRB-2 Correlation, WRB-2M, for Predicting Critical Heat Flux in 17x17 Rod Bundles with Modified LPD Mixing Vane Grids,” April 1999.

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Evaluation of the Transition to Westinghouse RFA-2 Fuel

11. WCAP-17642-P-A, Revision 1 (Proprietary) “Westinghouse Performance Analysis and Design Model (PAD5),” November 2017.

12. WCAP-17661-P-A, Revision 1 (Proprietary), “Improved RAOC and CAOC FQ Surveillance Technical Specifications,” February 2019. (ML19225C081)

13. WCAP-12472-P-A (Proprietary) “BEACON Core Monitoring and Operations Support System,” August 1994. (ML12270A386)

14. WCAP-12472-P-A, Addendum 4, Revision 0 (Proprietary) “BEACON Core Monitoring and Operation Support System, Addendum 4,” September 2012.

15. WCAP-8745-P-A (Proprietary) ³'HVLJQ%DVHVIRUWKH7KHUPDO2YHUSRZHU¨7DQG Thermal 2YHUWHPSHUDWXUH¨77ULS)XQFWLRQV´6HSWHPEHU

16. WCAP-12610-P-A & CENPD-404-P-A, Addendum 1-A (Proprietary) “Optimized ZIRLO,” July 2006. (ML062080563)

17. WCAP-16996-P-A, Revision 1 (Proprietary) “Realistic LOCA Evaluation Methodology Applied to the Full Spectrum of Break Sizes (FULL SPECTRUM LOCA Methodology),” November 2016. (ML17277A131)

18. WCAP-9401-P-A, “Verification Testing and Analysis of the 17 x 17 Optimized Fuel Assembly,” August 1981.

19. PWROG-16043-P-A, Revision 2, “PWROG Program to Address NRC Information Notice 2012-09: ‘Irradiation Effects on Fuel Assembly Spacer Grid Cush Strength’ for Westinghouse and CE PWR Fuel Designs,” November 2019.

20. WCAP-14565-P-A, “VIPRE-01 Modeling and Qualification for Pressurized Water Reactor Non-LOCA Thermal-Hydraulic Safety Analysis,” October 1999.

21. Letter from D. S. Collins (USNRC) to J. A. Gresham (Westinghouse), “Modified WRB-2 Correlation WRB-2M for Predicting Critical Heat Flux in 17x17 Rod Bundles with Modified LPD Mixing Vane Grids,” February 2006. (ML060320290)

22. WCAP-14565-P-A, Addendum 1-A, Revision 0, “Addendum 1 to WCAP 14565-P-A Qualification of ABB-NV Critical Heat Flux Correlations with VIPRE-01 Code,” August 2004.

23. WCAP-14565-P-A, Addendum 2-P-A, Revision 0, “Addendum 2 to WCAP-14565-P-A Extended Application of ABB-NV Correlation and Modified ABB-NV Correlation WLOP for PWR Low Pressure Applications,” April 2008.

24. NSAL-09-5, Revision 1, “Relaxed Axial Offset Control FQ Technical Specification Actions,” September 23, 2009.

25. NSAL-15-1, “Heat Flux Hot Channel Factor Technical Specification Surveillance,” February 3, 2015.

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Evaluation of the Transition to Westinghouse RFA-2 Fuel

26. Sequoyah Units 1 and 2 License Amendments 223/214 dated 4-21-97 (ML013320456).

27. WCAP-10216-P-A, Revision 1A (Proprietary) “Relaxation of Constant Axial Offset Control / FQ Surveillance Technical Specification,” February 1994.

28. WCAP-11837-P-A, Revision 0, “Extension of Methodology for Calculating Transition Core DNBR Penalties,” January 1990.

29. BAW-10133NP-A, Rev. 1, Addendum 1 and Addendum 2, “Mark-C Fuel Assembly LOCA-Seismic Analysis,” October 2000. (ML003767624)

30. TSTF-241-A, Revision 4, “Allow Time for Stabilization after Reducing Power due to QPTR out of Limit” (NRC approved on January 13, 1999). (ML040611034)

31. TSTF-290-A, Revision 0, “Revision to Hot Channel Factor Specifications, (NRC approved on June 30, 1999). (ML040630063)

32. Westinghouse Report WCAP-12610-P-A, Revision 0, “VANTAGE+ Fuel Assembly Reference Core Report,” April 1995.

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ATTACHMENT 1

Proposed TS Changes (Mark-Ups) for SQN Unit 1

CNL-20-014 - 11-

F. Post Accident Sampling (Section 22.3, II.B.3)

This condition has been deleted.

H. Instruments for Inadequate Core Cooling (Section 22.3, II.F.2)

(1) By January 1, 1982, TVA shall install a backup indication for incore thermocouples. This display shall be in the control room and cover the temperature range of 200 F - 2000 F.

(2) At the first outage of sufficient duration but no later than startup following the second refueling outage, TVA shall install reactor vessel water level instrumentation which meets NRC requirements.

I. Upgrade Emergency Support Facilities (Section 22.3, II.A.1.2)

(1) At the first outage of sufficient duration, but no later than startup following the second refueling outage, TVA shall update the Technical Support Facilities to meet NRC requirements.

(2) TVA shall maintain interim emergency support facilities (Technical Support Center, Operations Support Center and the Emergency Operations Facility) until the final facilities are complete.

J. Relief and Safety Valve Test Requirements (Section 22.2, II.D.1)

TVA shall conform to the results of the EPRI test program. TVA shall provide documentation for qualifying (a) reactor coolant system relief and safety valves, (b) piping and supports, and (c) block valves in accordance with the review schedule given in SECY 81-491 as approved by the Commission.

(24) Compliance with Regulatory Guide 1.97

TVA shall implement modifications necessary to comply with Revision 2 of Regulatory Guide 1.97, "Instrumentation for Light Water Cooled Nuclear Power Plants to Assess Plant Conditions During and Following An Accident," dated December 1980 by startup from the Unit 2 Cycle 4 refueling outage. Transition Core Peaking Penalties (25) Mixed Core DNBR Penalty

When Framatome HTP fuel assemblies are co-resident with the Westinghouse RFA-2 fuel assemblies: TVA will obtain NRC approval prior to startup for any cycle's core that involves a (a) The HTP fuel assemblies FN shall be maintained less than 1.61; reduction in the ǻdepartureH from nucleate boiling ratio initial transition core penalty (b) The RFA-2 fuel assemblies DNBR limit shall be reduced by: below that value stated in TVA's submittal on Framatome fuel conversion dated 1. 0.25% for the WRB-2M critical heat flux correlation 2. 0.50% forApril the 6,ABB-NV 1997. critical heat flux correlation

Renewed License No. DPR 77 September 28, 2015 For information only

This note is for NRC information

TABLE OF CONTENTS Page

1.0 USE AND APPLICATION 1.1 Definitions ...... 1.1-1 1.2 Logical Connectors ...... 1.2-1 1.3 Completion Times ...... 1.3-1 1.4 Frequency ...... 1.4-1

2.0 SAFETY LIMITS (SLs) ...... 2.0-1 2.1 SLs 2.2 SL Violations

3.0 LIMITING CONDITION FOR OPERATION (LCO) APPLICABILITY ...... 3.0-1 3.0 SURVEILLANCE REQUIREMENT (SR) APPLICABILITY ...... 3.0-4

3.1 REACTIVITY CONTROL SYSTEMS 3.1.1 SHUTDOWN MARGIN (SDM) ...... 3.1.1-1 3.1.2 Core Reactivity ...... 3.1.2-1 3.1.3 Moderator Temperature Coefficient (MTC) ...... 3.1.3-1 3.1.4 Rod Group Alignment Limits ...... 3.1.4-1 3.1.5 Shutdown Bank Insertion Limits ...... 3.1.5-1 3.1.6 Control Bank Insertion Limits ...... 3.1.6-1 3.1.7 Rod Position Indication ...... 3.1.7-1 3.1.8 PHYSICS TESTS Exceptions - MODE 2 ...... 3.1.8-1

3.2 POWER DISTRIBUTION LIMITS 3.2.1 Heat Flux Hot Channel Factor (FQ(X,Y,Z)) (RAOC-T(Z) Methodology) ...... 3.2.1-1 N 3.2.2 Nuclear Enthalpy Rise Hot Channel Factor (F ¨H(X,Y)) ...... 3.2.2-1 3.2.3 AXIAL FLUX DIFFERENCE (AFD) ...... 3.2.3-1 3.2.4 QUADRANT POWER TILT RATIO (QPTR) ...... 3.2.4-1

3.3 INSTRUMENTATION 3.3.1 Reactor Trip System (RTS) Instrumentation ...... 3.3.1-1 3.3.2 Engineered Safety Feature Actuation System (ESFAS) Instrumentation ...... 3.3.2-1 3.3.3 Post Accident Monitoring (PAM) Instrumentation ...... 3.3.3-1 3.3.4 Remote Shutdown Monitoring Instrumentation ...... 3.3.4-1 3.3.5 Loss of Power (LOP) Diesel Generator (DG) Start Instrumentation ...... 3.3.5-1 3.3.6 Containment Ventilation Isolation Instrumentation ...... 3.3.6-1 3.3.7 Control Room Emergency Ventilation System (CREVS) Actuation Instrumentation ...... 3.3.7-1 3.3.8 Auxiliary Building Gas Treatment System (ABGTS) Actuation Instrumentation ...... 3.3.8-1 3.3.9 Boron Dilution Monitoring Instrumentation (BDMI) ...... 3.3.9-1

3.4 REACTOR COOLANT SYSTEM (RCS) 3.4.1 RCS Pressure, Temperature, and Flow Departure from Nucleate Boiling (DNB) Limits ...... 3.4.1-1 3.4.2 RCS Minimum Temperature for Criticality ...... 3.4.2-1 3.4.3 RCS Pressure and Temperature (P/T) Limits ...... 3.4.3-1 3.4.4 RCS Loops - MODES 1 and 2 ...... 3.4.4-1

SEQUOYAH - UNIT 1 i Amendment 334, SLs 2.0

2.0 SAFETY LIMITS (SLs)

2.1 SLs the COLR 2.1.1 Reactor Core SLs 9

specified In MODES 1 and 2, the combination of THERMAL POWER, Reactor Coolant System (RCS) highest loop average temperature, and pressurizer pressure shall not exceed the limits shown in Figure 2.1.1-1; and the following SLs shall not be exceeded:

2.1.1.1 The departure from nucleate boiling ratio (DNBR) shall be maintained • 1.132 for the BHTP correlation, • 1.21 for the BWU-N correlation, and • 1.21 for the BWCMV correlation. 1.14 for the WRB-2M

2.1.1.2 The maximum local fuel pin centerline temperature shall be maintained < 5080 ”ƒ)GHFUHDVLQJE\ƒ)SHU0:'078RIEXUQXSIRU COPER1,&DSSOLFDWLRQVDQG”ƒ)GHFUHDVLQJE\ƒ)SHU 10,000 MWD/MTU of burnup for TACO3 applications.

2.1.2 Reactor Coolant System Pressure SL

In MODES 1, 2, 3, 4, and 5, the RCS SUHVVXUHVKDOOEHPDLQWDLQHG” 2735 psig.

2.2 SAFETY LIMIT VIOLATIONS

2.2.1 If SL 2.1.1 is violated, restore compliance and be in MODE 3 within 1 hour.

2.2.2 If SL 2.1.2 is violated:

2.2.2.1 In MODE 1 or 2, restore compliance and be in MODE 3 within 1 hour.

2.2.2.2 In MODE 3, 4, or 5, restore compliance within 5 minutes.

SEQUOYAH – UNIT 1 2.0-1 Amendment 334 6/V  Relocate to COLR

      

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6(482<$+±81,7  $PHQGPHQW Rod Group Alignment Limits 3.1.4

ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME

B.2.1.2 Initiate boration to restore 1 hour SDM to within limit.

AND

B.2.2 Reduce THERMAL 2 hours 32:(5WR” RTP.

AND

B.2.3 Verify SDM is within the Once per limits specified in the 12 hours COLR.

AND

B.2.4 Perform SR 3.2.1.1 and SR KRXUV 3.2.1.2.

AND

% Perform SR 3.2.2.1. KRXUV

AND

B.2.6 Re-evaluate safety GD\V analyses and confirm results remain valid for duration of operation under these conditions.

C. Required Action and C.1 Be in MODE 3. 6 hours associated Completion Time of Condition B not met.

D. More than one rod not D.1.1 Verify SDM is within the 1 hour within alignment limit. limits specified in the COLR.

OR

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6(482<$+±81,7  $PHQGPHQW FQ(Z) (RAOC-T(Z) Methodology) 3.2.1

3.2 POWER DISTRIBUTION LIMITS

3.2.1 Heat Flux Hot Channel Factor (FQ(Z)) (RAOC-T(Z) Methodology)

C W LCO 3.2.1 FQ(Z), as approximated by FQ(Z) and FQ (Z), shall be within the limits specified in the COLR.

APPLICABILITY: MODE 1.

ACTIONS

CONDITION REQUIRED ACTION COMPLETION TIME

A. ------NOTE------A.1 Reduce THERMAL 15 minutes after each Required Action A.4 C POWER • 1% RTP for FQ(Z) determination shall be completed C each 1% FQ(Z) exceeds whenever this Condition limit. is entered prior to increasing THERMAL AND POWER above the limit of Required Action A.1. A.2 Reduce Power Range 72 hours after each SR 3.2.1.2 is not C Neutron Flux – High trip F (Z) determination required to be Q setpoints • 1% for performed if this each 1% that THERMAL Condition is entered POWER is limited below prior to THERMAL RTP by Required POWER exceeding Action A.1. 75% RTP after a

refueling. AND ------

A.3 Reduce Overpower ¨T trip FC(Z) not within limit. 72 hours after each Q setpoints • 1% for each 1% C FQ(Z) determination that THERMAL POWER is limited below RTP by Required Action A.1.

AND

A.4 Perform SR 3.2.1.1 and Prior to increasing SR 3.2.1.2. THERMAL POWER above the limit of Required Action A.1

SEQUOYAH – UNIT 1 3.2.1-1 Amendment 334, FQ(Z) (RAOC-T(Z) Methodology) 3.2.1

ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME

W B. FQ (Z) not within limits B.1.1 Implement a RAOC 4 hours operating space specified in the COLR that restores W FQ (Z) to within its limits.

AND

B.1.2 Perform SR 3.2.1.1 and 72 hours SR 3.2.1.2 if control rod motion is required to comply with the new operating space.

OR

B.2.1 ------NOTE------Required Action B.2.4 shall be completed whenever Required Action B.2.1 is performed prior to increasing THERMAL POWER above the limit of Required Action B.2.1. ------

Limit allowable THERMAL 4 hours after each W POWER and AFD limits as FQ (Z) determination specified in the COLR.

AND

B.2.2 Limit Power Range 72 hours after each W Neutron Flux - High trip FQ (Z) determination setpoints • 1% for each 1% that THERMAL POWER is limited below RTP by Required Action B.2.1.

AND

SEQUOYAH – UNIT 1 3.2.1-2 Amendment 334, FQ(Z) (RAOC-T(Z) Methodology) 3.2.1

CONDITION REQUIRED ACTION COMPLETION TIME

B.2.3 Limit Overpower ¨T trip 72 hours after each W setpoints • 1% for each 1% FQ (Z) determination that THERMAL POWER is limited below RTP by Required Action B.2.1.

AND

B.2.4 Perform SR 3.2.1.1 and SR 3.2.1.2. Prior to increasing THERMAL POWER above the limit of Required Action B.2.1

C. Required Action and C.1 Be in MODE 2. 6 hours associated Completion Time not met.

SURVEILLANCE REQUIREMENTS

SURVEILLANCE FREQUENCY

C SR 3.2.1.1 Verify FQ(Z) is within limit. Once after each refueling prior to THERMAL POWER exceeding 75% RTP

AND

Once within 24 hours after achieving equilibrium conditions after exceeding, by • 10% RTP, the THERMAL

SEQUOYAH – UNIT 1 3.2.1-3 Amendment 334, FQ(Z) (RAOC-T(Z) Methodology) 3.2.1

SURVEILLANCE REQUIREMENTS (continued)

SURVEILLANCE FREQUENCY

POWER at which C FQ(Z) was last verified

AND

In accordance with the Surveillance Frequency Control Program

W SR 3.2.1.2 Verify FQ (Z) is within limit. Once after each refueling within 24 hours after THERMAL POWER exceeds 75% RTP

AND

Once within 24 hours after achieving equilibrium conditions after exceeding, by • 10% RTP, the THERMAL POWER at which W FQ (Z) was last verified

AND

In accordance with the Surveillance Frequency Control Program

SEQUOYAH – UNIT 1 3.2.1-4 Amendment 334, Replace with new TS 3.2.2 on the following pages Fǻ+(X,Y) 3.2.2

3.2 POWER DISTRIBUTION LIMITS

3.2.2 Nuclear Enthalpy Rise Hot Channel Factor Fǻ+(X,Y)

LCO 3.2.2 Fǻ+(X,Y) shall be within the limits specified in the COLR.

APPLICABILITY: MODE 1.

ACTIONS

CONDITION REQUIRED ACTION COMPLETION TIME

A. ------NOTE------A.1 Reduce allowable 2 hours Required Actions A.3 THERMAL POWER from and A.5 must be 573E\•55+PXOWLSOLHG completed whenever times the Fǻ+ min margin. Condition A is entered. ------AND

Fǻ+ min margin < 0. A.2 Reduce Power Range 72 hours Neutron Flux – High trip VHWSRLQWVE\•55+ multiplied times the Fǻ+ min margin.

AND

A.3 Perform SR 3.2.2.1. 24 hours

AND

A.4 Reduce Overtemperature 48 hours ¨T trip setpoint by • TRH multiplied times the Fǻ+ min margin.

AND

SEQUOYAH – UNIT 1 3.2.2-1 Amendment 334 N F¨H 3.2.2

3.2 POWER DISTRIBUTION LIMITS

N 3.2.2 Nuclear Enthalpy Rise Hot Channel Factor (F¨H)

N LCO 3.2.2 F¨H shall be within the limits specified in the COLR.

APPLICABILITY: MODE 1.

ACTIONS

CONDITION REQUIRED ACTION COMPLETION TIME

N A. ------NOTE------A.1.1 Restore F¨H to within limit. 4 hours Required Actions A.2 and A.3 must be OR completed whenever Condition A is entered. A.1.2.1 Reduce THERMAL 4 hours ------POWER to < 50% RTP.

N F¨H not within limit. AND

A.1.2.2 Reduce Power Range 72 hours Neutron Flux – High trip setpoints to ” 55% RTP.

AND

A.2 Perform SR 3.2.2.1. 24 hours

AND

A.3 ------NOTE------THERMAL POWER does not have to be reduced to comply with this Required Action. ------

Perform SR 3.2.2.1. Prior to THERMAL POWER exceeding 50% RTP

AND

SEQUOYAH – UNIT 1 3.2.2-1 Amendment 334, N F¨H 3.2.2

ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME

Prior to THERMAL POWER exceeding 75% RTP

AND

24 hours after THERMAL POWER reaching • 95% RTP

B. Required Action and B.1 Be in MODE 2. 6 hours associated Completion Time not met.

SURVEILLANCE REQUIREMENTS

SURVEILLANCE FREQUENCY

N SR 3.2.2.1 Verify F¨H is within limits specified in the COLR. Once after each refueling prior to THERMAL POWER exceeding 75% RTP

AND

In accordance with the Surveillance Frequency Control Program

SEQUOYAH – UNIT 1 3.2.2-2 Amendment 334, QPTR 3.2.4

3.2 POWER DISTRIBUTION LIMITS

3.2.4 QUADRANT POWER TILT RATIO (QPTR)

LCO 3.2.4 7KH4375VKDOOEH” 

APPLICABILITY: 02'(ZLWK7+(50$/32:(5!573

ACTIONS

CONDITION REQUIRED ACTION COMPLETION TIME

A. QPTR not within limit. A.1 Reduce THERMAL 2 hours after each 32:(5•IURP573IRU QPTR determination HDFKRI4375! 

AND

A.2 Determine QPTR. Once per 12 hours

AND

A.3 Perform SR 3.2.1.1, 24 hours after SR 3.2.1.2, SR achieving equilibrium 3.2.1.3,and conditions from a SR 3.2.2.1., and SR 3.2.2.2. THERMAL POWER reduction per Required Action A.1

AND

2QFHSHUGD\V thereafter

AND

SEQUOYAH – UNIT 1 3.2.4-1 Amendment 334 QPTR 3.2.4

ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME

A.4 Reevaluate safety analyses Prior to increasing and confirm results remain THERMAL POWER valid for duration of operation above the limit of under this condition. Required Action A.1

AND

$ ------NOTES------1. Perform Required ActLRQ$RQO\DIWHU Required Action A.4 is completed.

2.Required Action A.6 shall be completed whenever 5HTXLUHG$FWLRQ$LV performed. ------

Normalize excore detectors to Prior to increasing restore QPTR to within limit. THERMAL POWER above the limit of Required Action A.1 AND

A.6 ------NOTE------Perform Required Action A.6 RQO\DIWHU5HTXLUHG$FWLRQ$ is completed. ------

Perform SR 3.2.1.1, Within 24 hours after SR 3.2.1.2, SR 3.2.1.3,and achieving equilibrium SR 3.2.2.1., and SR 3.2.2.2. conditions at RTP QRWWRH[FHHG hours after increasing THERMAL POWER above the limit of Required Action A.1

SEQUOYAH – UNIT 1 3.2.4-2 Amendment 334 QPTR 3.2.4

ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME

B. Required Action and %1 Reduce THERMAL 4 hours associated Completion POWER to ”  RTP. Time not met.

SURVEILLANCE REQUIREMENTS

SURVEILLANCE FREQUENCY

SR 3.2.4.1 ------NOTES------ With input from one Power Range Neutron Flux channel inoperable and THERMAL POWER” 573WKHUHPDLQLQJWKUHHSRZHUUDQJH channels can be used for calculating QPTR.

 SR 3.2.4.2 may be performed in lieu of this Surveillance. ------

Verify QPTR is within limit by calculation. In accordance with the Surveillance Frequency Control Program

SR 3.2.4.2 ------NOTE------Only required to be performed if input to QPTR from one or more Power RangeNeutron Flux channels are inoperable with7+(50$/ 32:(5! RTP. ______

SEQUOYAH - UNIT 1 3.2.4-3 Amendment 3 4 3I Verify QPTR is within limit using core power Once within 12 distribution measurement information.the movable hours incore detectors. AND

In accordance with the Surveillance Frequency Control Program

SEQUOYAH - UNIT 1 3.2.4-3 Amendment 3 4 3I RTS Instrumentation 3.3.1

SURVEILLANCE REQUIREMENTS ------NOTE------Refer to Table 3.3.1-1 to determine which SRs apply for each RTS Function. ------

SURVEILLANCE FREQUENCY

SR 3.3.1.1 Perform CHANNEL CHECK. In accordance with the Surveillance Frequency Control Program

SR 3.3.1.2 ------NOTE------Not required to be performed until 12 hours after THERMAL POWER is t 573 ------

Compare results of calorimetric heat balance In accordance calculation to power range channel output. Adjust with the power range channel output if absolute difference is Surveillance ! Frequency Control Program

SR 3.3.1.3 ------NOTE------1RWUHTXLUHGWREHSHUIRUPHGXQWLOKRXUV after THERMAL POWER is t 573 ------

Compare results of the incore core power In accordance distribution detector measurements to Nuclear with the Instrumentation System (NIS) AFD. Adjust NIS Surveillance channel if absolute difference is t  Frequency Control Program

SR 3.3.1.4 ------NOTE------This Surveillance must be performed on the reactor trip bypass breaker prior to placing the bypass breaker in service. ------

Perform TADOT. In accordance with the Surveillance Frequency Control Program

SEQUOYAH – UNIT 1 3.3.1- Amendment 334 RTS Instrumentation 3.3.1

SURVEILLANCE REQUIREMENTS (continued)

SURVEILLANCE FREQUENCY

SR  Perform ACTUATION LOGIC TEST. In accordance with the Surveillance Frequency Control Program

SR 3.3.1.6 ------NOTE------Not required to be performed until 24 hours after 7+(50$/32:(5LV•573 ------

Calibrate excore channels to agree with incore  In accordance core power distribution detector with the measurements. Surveillance Frequency Control Program

SR  ------NOTE------Not required to be performed for source range instrumentation prior to entering MODE 3 from MODE 2 until 4 hours after entry into MODE 3. ------

Perform COT. In accordance with the Surveillance Frequency Control Program

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6(482<$+±81,7  $PHQGPHQW Design Features 4.0

4.0 DESIGN FEATURES

4.1 Site Location

The Sequoyah Nuclear Plant is located on a site near the geographical center of Hamilton County, Tennessee, on a peninsula on the western shore of at mile (TRM) 484.5. The Sequoyah site is approximately 7.5 miles northeast of the nearest city limit of Chattanooga, Tennessee, 14 miles west-northwest of Cleveland, Tennessee, and approximately 31 miles south-southwest of TVA's .

4.2 Reactor Core Optimized ZirloTM

4.2.1 Fuel Assemblies

The reactor shall contain 193 fuel assemblies. Each assembly shall consist of a matrix of Zircaloy or M5 clad fuel rods with an initial composition of natural or slightly enriched uranium dioxide (UO2) as fuel material. Limited substitutions of zirconium alloy or stainless steel filler rods for fuel rods, in accordance with approved applications of fuel rod configurations, may be used. Fuel assemblies shall be limited to those fuel designs that have been analyzed with applicable NRC staff approved codes and methods and shown by tests or analyses to comply with all fuel safety design bases. A limited number of lead test assemblies that have not completed representative testing may be placed in nonlimiting core regions. Sequoyah is authorized to place a limited number of lead test assemblies into the reactor as described in the Framatome-Cogema Fuels report BAW-2328, beginning with the Unit 1 Operating Cycle 12.

4.2.2 Control Rod Assemblies

------NOTE------Operation with 52 full length control rod assemblies (with no control rod assembly installed in core location H-08) is permitted during Cycle 24. ------

The reactor core shall contain 53 full length and no part 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 80 percent silver, 15 percent indium, and 5 percent cadmium. All control rods shall be clad with stainless steel tubing. 52

4.3 Fuel Storage (with no full length control rod assembly in core location H-08) 4.3.1 Criticality

4.3.1.1 The spent fuel storage racks are designed and shall be maintained with:

a. Fuel assemblies having a maximum U-235 enrichment of 5.0 weight percent;

SEQUOYAH – UNIT 1 4.0-1 Amendment 334 348 Reporting Requirements 5.6

5.6 Reporting Requirements

5.6.3 CORE OPERATING LIMITS REPORT

a. Core operating limits shall be established prior to each reload cycle, or prior to any remaining portion of a reload cycle, and shall be documented in the COLR for the following: 1. LCO 2.1.1, "Reactor Core Safety Limits"; 2. 1. LCO 3.1.1, "SHUTDOWN MARGIN (SDM)";

3. 2. LCO 3.1.3, "Moderator Temperature Coefficient (MTC)"; 4. LCO 3.1.4, "Rod Group Alignment Limits"; 5. 3. LCO 3.1.5, "Shutdown Bank Insertion Limits";

6. 4. LCO 3.1.6, "Control Bank Insertion Limits"; 7. LCO 3.1.8, "PHYSICS TESTS Exceptions - MODE 2"; 8. 5. LCO 3.2.1, "Heat Flux Hot Channel Factor (F (X, Y, Z))"; Q N

9. 6. LCO 3.2.2, "Nuclear Enthalpy Rise Hot Channel Factor (F¨+(X,Y))"; (RAOC-T(Z) 10. 7. LCO 3.2.3, "AXIAL FLUX DIFFERENCE (AFD)"; Methodology) ;

11. 8. LCO 3.3.1, "Reactor Trip System (RTS) Instrumentation," f1(¨I) limits for 2YHUWHPSHUDWXUH¨7DQGf2(¨I) limits for 2YHUSRZHU¨71RPLQDO Trip Setpoints; and 12. LCO 3.4.1, "RCS Pressure, Temperature, and Flow Departure from 13. 9. LCO 3.9.1, "Boron Concentration." Nucleate Boiling (DNB) Limits"; and

b. The analytical methods used to determine the core operating limits shall be those previously reviewed and approved by the NRC, specifically those described in the following documents:

Add 1. BAW-10180-A, Revision 1, "NEMO - Nodal Expansion Method Insert A Optimized," March 1993;

2. BAW-10169P-A, Revision 0, "RSG Plant Safety Analysis - B&W Safety Analysis Methodology for Recirculating Steam Generator Plants," October 1989;

3. BAW-10163P-A, Revision 0, "Core Operating Limit Methodology for Westinghouse-Designed PWRs," June 1989;

SEQUOYAH – UNIT 1 5.6-2 Amendment 334 Reporting Requirements 5.6

5.6 Reporting Requirements

5.6.3 CORE OPERATING LIMITS REPORT (continued)

4. EMF-2328(P)(A), "PWR Small Break LOCA Evaluation Model," March 2001;

5. BAW-10227P-A, Revision 1, "Evaluation of Advanced Cladding and Structural Material (M5) in PWR Reactor Fuel," June 2003;

6. BAW-10186P-A, Revision 2, "Extended Burnup Evaluation," June 2003;

7. EMF-2103P-A, Revision 0, "Realistic Large Break LOCA Methodology for Pressurized Water Reactors," April 2003;

8. BAW-10241P-A, Revision 1, "BHTP DNB Correlation Applied with LYNXT," July 2005;

9. BAW-10199P-A, Revision 0, "The BWU Critical Heat Flux Correlations," August 1996;

10. BAW-10189P-A, "CHF Testing and Analysis of the Mark-BW Fuel Assembly Design," January 1996;

11. BAW-10159P-A, "BWCMV Correlation of Critical Heat Flux in Mixing Vane Grid Fuel Assemblies," August 1990; and

12. BAW-10231P-A, Revision 1, "COPERNIC Fuel Rod Design Computer Code" January 2004.

c. The core operating limits shall be determined such that all applicable limits (e.g., fuel thermal mechanical limits, core thermal hydraulic limits, Emergency Core Cooling Systems (ECCS) limits, nuclear limits such as SDM, transient analysis limits, and accident analysis limits) of the safety analysis are met.

d. The COLR, including any midcycle revisions or supplements, shall be provided within 30 days of issuance for each reload cycle to the NRC.

SEQUOYAH – UNIT 1 5.6-3 Amendment 334 INSERT A

1. WCAP-8745-P-$³'HVLJQ%DVHVIRUWKH7KHUPDO2YHUSRZHU¨7DQG7KHUPDO 2YHUWHPSHUDWXUH¨77ULS)XQFWLRQV´6HSWHPEHU;

2. WCAP-9272-P-A, “Westinghouse Reload Safety Evaluation Methodology,” July 1985;

3. WCAP-10216-P-A, Revision 1A, “Relaxation of Constant Axial Offset Control – FQ Surveillance Technical Specification,” February 1994;

4. WCAP-10444-P-A, “Reference Core Report VANTAGE 5 Fuel Assembly,” September 1985;

5. WCAP-10444-P-A Addendum 2-A, “VANTAGE 5H Fuel Assembly,” February 1989;

6. WCAP-10965-P-A, “ANC: A Westinghouse Advanced Nodal Computer Code,” September 1986;

7. WCAP-10965-P-A, Addendum 2-A, Revision 0, “Qualification of the New Pin Power Recovery Methodology,” September 2010;

8. WCAP-11397-P-A, “Revised Thermal Design Procedure,” April 1989;

9. WCAP-12610-P-A, “VANTAGE+ Fuel Assembly Reference Core Report,” April 1995;

10. WCAP-12610-P-A & CENPD-404-P-A, Addendum 1-A, “Optimized ZIRLOTM,” July 2006;

11. WCAP-14565-P-A, “VIPRE-01 Modeling and Qualification for Pressurized Water Reactor Non-LOCA Thermal-Hydraulic Safety Analysis,” October 1999;

12. WCAP-14565-P-A, Addendum 1-A, Revision 0, “Addendum 1 to WCAP 14565-P-A Qualification of ABB-NV Critical Heat Flux Correlations with VIPRE-01 Code,” August 2004;

13. WCAP-14565-P-A, Addendum 2-P-A, Revision 0, “Addendum 2 to WCAP-14565-P-A Extended Application of ABB-NV Correlation and Modified ABB-NV Correlation WLOP for PWR Low Pressure Applications,” April 2008;

14. WCAP-15025-P-A, “Modified WRB-2 Correlation, WRB-2M, for Predicting Critical Heat Flux in 17x17 Rod Bundles with Modified LPD Mixing Vane Grids,” April 1999;

15. WCAP-16045-P-A, “Qualification of the Two-Dimensional Transport Code PARAGON,” August 2004;

16. WCAP-16045-P-A, Addendum 1-A, “Qualification of the NEXUS Nuclear Data Methodology,” August 2007;

17. WCAP-16996-P-A, Revision 1, “Realistic LOCA Evaluation Methodology Applied to the Full Spectrum of Break Sizes (FULL SPECTRUM LOCA Methodology),” November 2016; and

18. WCAP-17661-P-A, Revision 1, "Improved RAOC and CAOC FQ Surveillance Technical Specifications," February 2019. Enclosure 1

Evaluation of the Transition to Westinghouse RFA-2 Fuel

ATTACHMENT 2

Proposed TS Changes (Mark-Ups) for SQN Unit 2

CNL-20-014 - 11 -

s. Primary Coolant Outside Containment (Section 22.2, III.D.1.1)

Prior to exceeding 5 percent power level, TVA is required to complete the leak tests on Unit 2, and results are to be submitted within 30 days from the completion of the testing.

(17) Surveillance Interval Extension

The performance interval for the 36-month surveillance requirements in TS 4.3.2.1.3 shall be extended to May 18, 1996, to coincide with the Cycle 7 refueling outage. The extended interval shall not exceed a total of 50 months for the 36-month surveillances. Transition Core Peaking Penalties (18) Mixed Core DNBR Penalty When Framatome HTP fuel assemblies are co-resident with the Westinghouse RFA-2 fuel assemblies: N (a) The HTP fuel assembliesTVA will obtain F ǻH shallNRC be approval maintained prior less to thanstartup 1.61; for any cycle's core that involves a (b) The RFA-2 fuelreduction assemblies in theDNBR departure limit shall from be reduced nucleate by: boiling ratio initial transition core penalty 1. 0.25% for thebelow WRB-2M that value critical stated heat flux in TVA'scorrelation submittal on Framatome fuel conversion dated 2. 0.50% for theApril ABB-NV 6, 1997. critical heat flux correlation

(19) Steam Generator Replacement Project

During the Unit 1 Cycle 12 refueling and steam generator replacement outage, lifts of heavy loads will be performed in accordance with Table 3.1 of NRC Safety Evaluation dated March 26, 2003.

(20) Control Room Air Conditioning System Maintenance

TVA commits to the use of a portable chiller package and air-handling unit to provide alternate cooling if both trains of the control room air condition system become inoperable during the maintenance activities to upgrade the compressors and controls or immediately enter Technical Specification 3.0.3.

(21) Mitigation Strategy License Condition

Develop and maintain strategies for addressing large fires and explosions and that include the following key areas:

(a) Fire fighting response strategy and with the following elements: 1. Pre-defined coordinated fire response strategy and guidance 2. Assessment of mutual aid fire fighting assets 3. Designated staging areas for equipment and materials 4. Command and control 5. Training of response personnel

Renewed License No. DPR 79 September 28, 2015 For Information Only

This note is for NRC information TABLE OF CONTENTS Page

1.0 USE AND APPLICATION 1.1 Definitions ...... 1.1-1 1.2 Logical Connectors ...... 1.2-1 1.3 Completion Times ...... 1.3-1 1.4 Frequency ...... 1.4-1

2.0 SAFETY LIMITS (SLs) ...... 2.0-1 2.1 SLs 2.2 SL Violations

3.0 LIMITING CONDITION FOR OPERATION (LCO) APPLICABILITY ...... 3.0-1 3.0 SURVEILLANCE REQUIREMENT (SR) APPLICABILITY ...... 3.0-4

3.1 REACTIVITY CONTROL SYSTEMS 3.1.1 SHUTDOWN MARGIN (SDM) ...... 3.1.1-1 3.1.2 Core Reactivity ...... 3.1.2-1 3.1.3 Moderator Temperature Coefficient (MTC) ...... 3.1.3-1 3.1.4 Rod Group Alignment Limits ...... 3.1.4-1 3.1.5 Shutdown Bank Insertion Limits ...... 3.1.5-1 3.1.6 Control Bank Insertion Limits ...... 3.1.6-1 3.1.7 Rod Position Indication ...... 3.1.7-1 3.1.8 PHYSICS TESTS Exceptions - MODE 2 ...... 3.1.8-1 (RAOC-T(Z) Methodology) 3.2 POWER DISTRIBUTION LIMITS 3.2.1 Heat Flux Hot Channel Factor (F Q(X,Y,Z)) ...... 3.2.1-1 3.2.2 Nuclear Enthalpy Rise Hot Channel Factor (F¨+(X,Y)) ...... 3.2.2-1 3.2.3 AXIAL FLUX DIFFERENCE (AFD) ...... 3.2.3-1 3.2.4 QUADRANT POWER TILT RATIO (QPTR) ...... 3.2.4-1

N 3.3 INSTRUMENTATION F ȜH 3.3.1 Reactor Trip System (RTS) Instrumentation ...... 3.3.1-1 3.3.2 Engineered Safety Feature Actuation System (ESFAS) Instrumentation ...... 3.3.2-1 3.3.3 Post Accident Monitoring (PAM) Instrumentation ...... 3.3.3-1 3.3.4 Remote Shutdown Monitoring Instrumentation ...... 3.3.4-1 3.3.5 Loss of Power (LOP) Diesel Generator (DG) Start Instrumentation ...... 3.3.5-1 3.3.6 Containment Ventilation Isolation Instrumentation ...... 3.3.6-1 3.3.7 Control Room Emergency Ventilation System (CREVS) Actuation Instrumentation ...... 3.3.7-1 3.3.8 Auxiliary Building Gas Treatment System (ABGTS) Actuation Instrumentation ...... 3.3.8-1 3.3.9 Boron Dilution Monitoring Instrumentation (BDMI) ...... 3.3.9-1

3.4 REACTOR COOLANT SYSTEM (RCS) 3.4.1 RCS Pressure, Temperature, and Flow Departure from Nucleate Boiling (DNB) Limits ...... 3.4.1-1 3.4.2 RCS Minimum Temperature for Criticality ...... 3.4.2-1 3.4.3 RCS Pressure and Temperature (P/T) Limits ...... 3.4.3-1 3.4.4 RCS Loops - MODES 1 and 2 ...... 3.4.4-1

SEQUOYAH - UNIT 2 i Amendment 327 SLs 2.0

2.0 SAFETY LIMITS (SLs)

2.1 SLs the COLR 2.1.1 Reactor Core SLs 9 specified In MODES 1 and 2, the combination of THERMAL POWER, Reactor Coolant System (RCS) highest loop average temperature, and pressurizer pressure shall not exceed the limits shown in Figure 2.1.1-1; and the following SLs shall not be exceeded:

2.1.1.1 The departure from nucleate boiling ratio (DNBR) shall be maintained • 1.132 for the BHTP correlation, • 1.21 for the BWU-N correlation, and • 1.21 for the BWCMV correlation. 1.14 for the WRB-2M 2.1.1.2 The maximum local fuel pin centerline temperature shall be maintained ”ƒ)GHFUHDVLQJE\ƒ)SHU0:'078RIEXUQXSIRU < 5080 COPER1,&DSSOLFDWLRQVDQG”ƒ)GHFUHDVLQJE\ƒ)SHU 10,000 MWD/MTU of burnup for TACO3 applications.

2.1.2 Reactor Coolant System Pressure SL

In MODES 1, 2, 3, 4, and 5, the RCS SUHVVXUHVKDOOEHPDLQWDLQHG” 2735 psig.

2.2 SAFETY LIMIT VIOLATIONS

2.2.1 If SL 2.1.1 is violated, restore compliance and be in MODE 3 within 1 hour.

2.2.2 If SL 2.1.2 is violated:

2.2.2.1 In MODE 1 or 2, restore compliance and be in MODE 3 within 1 hour.

2.2.2.2 In MODE 3, 4, or 5, restore compliance within 5 minutes.

SEQUOYAH – UNIT 2 2.0-1 Amendment 327 SLs 2.0

Relocate to COLR

0.0 0.2 0.4 0.6 0.8 1.0 1.2

FRACTION OF RATED THERMAL POWER

Figure 2.1.1-1 (page 1 of 1) Reactor Core Safety Limit - Four Loops in Operation

SEQUOYAH – UNIT 2 2.0-2 Amendment 327 Rod Group Alignment Limits 3.1.4

ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME

B.2.1.2 Initiate boration to restore 1 hour SDM to within limit.

AND

B.2.2 Reduce THERMAL 2 hours POWER to ” 75% RTP.

AND

B.2.3 Verify SDM is within the Once per limits specified in the 12 hours COLR.

AND and SR 3.2.1.2

B.2.4 Perform SR 3.2.1.1. 72 hours

AND

B.2.5 Perform SR 3.2.2.1. 72 hours AND

B.2.6 Re-evaluate safety analyses and confirm 5 days results remain valid for duration of operation under these conditions.

C. Required Action and C.1 Be in MODE 3. 6 hours associated Completion Time of Condition B not met.

D. More than one rod not D.1.1 Verify SDM is within the 1 hour within alignment limit. limits specified in the COLR.

OR

SEQUOYAH – UNIT 2 3.1.4-2 Amendment 327 Rod Position Indication 3.1.7

3.1 REACTIVITY CONTROL SYSTEMS

3.1.7 Rod Position Indication

LCO 3.1.7 The Rod Position Indication System and the Demand Position Indication System shall be OPERABLE.

APPLICABILITY: MODES 1 and 2.

ACTIONS ------NOTES------1. Separate Condition entry is allowed for each inoperable rod position indicator and each demand position indicator.

2. LCO 3.0.4.a and b are not applicable for Required Actions A.2.1 and A.2.2 following a startup from a refueling outage, or following entry into MODE 5 of sufficient duration to safely repair an inoperable rod position indication. ------

CONDITION REQUIRED ACTION COMPLETION TIME

A. One rod position A.1 Verify the position of the Once per 12 hours indicator per bank rods with inoperable inoperable. position indicators indirectly by using movable incore detectors.

OR

------NOTE------Required Actions A.2.1 and A.2.2 may only be applied to one inoperable rod position indicator. ------

A.2.1 Verify position of the 8 hours rod with inoperable position indicator indirectly AND by using movable incore detectors. core power distribution measurement information

SEQUOYAH – UNIT 2 3.1.7-1 Amendment 327 Rod Position Indication 3.1.7

ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME

B. More than one rod B.1 Place the control rods Immediately position indicator per under manual control. bank inoperable. AND

B.2 Monitor and record Reactor Once per 1 hour Coolant System Tavg.

AND

B.3 Verify the position of the Once per 12 hours rods with inoperable position indicators indirectly by using the movable incore detectors.

AND

B.4 Restore inoperable position 24 hours indicators to OPERABLE status such that a maximum of one rod position indicator per bank is inoperable.

C. One or more rods with C.1 Verify the position of the Immediately inoperable position rods with inoperable indicators have been position indicators indirectly moved in excess of 24 by using movable incore steps in one direction detectors. since the last determination of the OR rod’s position. C.2 Reduce THERMAL 8 hours POWER to < 50% RTP.

core power distribution measurement information

SEQUOYAH – UNIT 2 3.1.7-3 Amendment 327 Replace with new TS 3.2.1 on the FQ(X,Y,Z) 3.2.1 following pages

3.2 POWER DISTRIBUTION LIMITS

3.2.1 Heat Flux Hot Channel Factor (FQ(X,Y,Z))

LCO 3.2.1 FQ(X,Y,Z) shall be within the limits specified in the COLR.

APPLICABILITY: MODE 1.

ACTIONS

CONDITION REQUIRED ACTION COMPLETION TIME

A. ------NOTE------A.1 Reduce THERMAL 15 minutes after each C Required Action A.5 32:(5• 1% RTP for FQ (X,Y,Z) C shall be completed each 1% FQ (X,Y,Z) determination whenever this Condition exceeds limit. is entered. ------AND

C FQ (X,Y,Z) not within the A.2 Reduce, by administrative 2 hours after each C steady state limit. means, $)'OLPLWV•IRU FQ (X,Y,Z) C each 1% FQ (X,Y,Z) exceeds determination limit.

AND

A.3 5HGXFH2YHUSRZHU¨7WULS 48 hours after each C VHWSRLQWV•IRUHDFK1% FQ (X,Y,Z) C FQ (X,Y,Z) exceeds limit. determination

AND

A.4 Reduce Power Range 72 hours after each C Neutron Flux – High trip FQ (X,Y,Z) VHWSRLQWV•IRUHDFK determination C FQ (X,Y,Z) exceeds limit.

AND

A.5 Perform SR 3.2.1.1, Prior to increasing SR 3.2.1.2, and SR 3.2.1.3. THERMAL POWER above the limit of Required Action A.1

SEQUOYAH – UNIT 2 3.2.1-1 Amendment 327 FQ(Z) (RAOC-T(Z) Methodology) 3.2.1

3.2 POWER DISTRIBUTION LIMITS

3.2.1 Heat Flux Hot Channel Factor (FQ(Z)) (RAOC-T(Z) Methodology)

C W LCO 3.2.1 FQ(Z), as approximated by FQ(Z) and FQ (Z), shall be within the limits specified in the COLR.

APPLICABILITY: MODE 1.

ACTIONS

CONDITION REQUIRED ACTION COMPLETION TIME

A. ------NOTE------A.1 Reduce THERMAL 15 minutes after each Required Action A.4 C POWER • 1% RTP for FQ(Z) determination shall be completed C each 1% FQ(Z) exceeds whenever this Condition limit. is entered prior to increasing THERMAL AND POWER above the limit of Required Action A.1. A.2 Reduce Power Range 72 hours after each SR 3.2.1.2 is not C Neutron Flux – High trip F (Z) determination required to be Q setpoints • 1% for performed if this each 1% that THERMAL Condition is entered POWER is limited below prior to THERMAL RTP by Required POWER exceeding Action A.1. 75% RTP after a

refueling. AND ------

A.3 Reduce Overpower ¨T trip FC(Z) not within limit. 72 hours after each Q setpoints • 1% for each 1% C FQ(Z) determination that THERMAL POWER is limited below RTP by Required Action A.1.

AND

A.4 Perform SR 3.2.1.1 and Prior to increasing SR 3.2.1.2. THERMAL POWER above the limit of Required Action A.1

SEQUOYAH – UNIT 2 3.2.1-1 Amendment 327, FQ(Z) (RAOC-T(Z) Methodology) 3.2.1

ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME

W B. FQ (Z) not within limits B.1.1 Implement a RAOC 4 hours operating space specified in the COLR that restores W FQ (Z) to within its limits.

AND

B.1.2 Perform SR 3.2.1.1 and 72 hours SR 3.2.1.2 if control rod motion is required to comply with the new operating space.

OR

B.2.1 ------NOTE------Required Action B.2.4 shall be completed whenever Required Action B.2.1 is performed prior to increasing THERMAL POWER above the limit of Required Action B.2.1. ------

Limit allowable THERMAL 4 hours after each W POWER and AFD limits as FQ (Z) determination specified in the COLR.

AND

B.2.2 Limit Power Range 72 hours after each W Neutron Flux - High trip FQ (Z) determination setpoints • 1% for each 1% that THERMAL POWER is limited below RTP by Required Action B.2.1.

AND

SEQUOYAH – UNIT  3.2.1-2 Amendment 334, FQ(Z) (RAOC-T(Z) Methodology) 3.2.1

CONDITION REQUIRED ACTION COMPLETION TIME

B.2.3 Limit Overpower ¨T trip 72 hours after each W setpoints • 1% for each 1% FQ (Z) determination that THERMAL POWER is limited below RTP by Required Action B.2.1.

AND

B.2.4 Perform SR 3.2.1.1 and SR 3.2.1.2. Prior to increasing THERMAL POWER above the limit of Required Action B.2.1

C. Required Action and C.1 Be in MODE 2. 6 hours associated Completion Time not met.

SURVEILLANCE REQUIREMENTS

SURVEILLANCE FREQUENCY

C SR 3.2.1.1 Verify FQ(Z) is within limit. Once after each refueling prior to THERMAL POWER exceeding 75% RTP

AND

Once within 24 hours after achieving equilibrium conditions after exceeding, by • 10% RTP, the THERMAL

SEQUOYAH – UNIT  3.2.1-3 Amendment 334, FQ(Z) (RAOC-T(Z) Methodology) 3.2.1

SURVEILLANCE REQUIREMENTS (continued)

SURVEILLANCE FREQUENCY

POWER at which C FQ(Z) was last verified

AND

In accordance with the Surveillance Frequency Control Program

W SR 3.2.1.2 Verify FQ (Z) is within limit. Once after each refueling within 24 hours after THERMAL POWER exceeds 75% RTP

AND

Once within 24 hours after achieving equilibrium conditions after exceeding, by • 10% RTP, the THERMAL POWER at which W FQ (Z) was last verified

AND

In accordance with the Surveillance Frequency Control Program

SEQUOYAH – UNIT  3.2.1-4 Amendment 334, Replace with new TS 3.2.2 on Fǻ+(X,Y) the following pages 3.2.2

3.2 POWER DISTRIBUTION LIMITS

3.2.2 Nuclear Enthalpy Rise Hot Channel Factor Fǻ+(X,Y)

LCO 3.2.2 Fǻ+(X,Y) shall be within the limits specified in the COLR.

APPLICABILITY: MODE 1.

ACTIONS

CONDITION REQUIRED ACTION COMPLETION TIME

A. ------NOTE------A.1 Reduce allowable 2 hours Required Actions A.3 THERMAL POWER from and A.5 must be 573E\•55+PXOWLSOLHG completed whenever times the Fǻ+ min margin. Condition A is entered. ------AND

Fǻ+ min margin < 0. A.2 Reduce Power Range 72 hours Neutron Flux – High trip VHWSRLQWVE\•55+ multiplied times the Fǻ+ min margin.

AND

A.3 Perform SR 3.2.2.1. 24 hours

AND

A.4 Reduce Overtemperature 48 hours ¨T trip setpoint by • TRH multiplied times the Fǻ+ min margin.

AND

SEQUOYAH – UNIT 2 3.2.2-1 Amendment 327 N F¨H 3.2.2

3.2 POWER DISTRIBUTION LIMITS

N 3.2.2 Nuclear Enthalpy Rise Hot Channel Factor (F¨H)

N LCO 3.2.2 F¨H shall be within the limits specified in the COLR.

APPLICABILITY: MODE 1.

ACTIONS

CONDITION REQUIRED ACTION COMPLETION TIME

N A. ------NOTE------A.1.1 Restore F¨H to within limit. 4 hours Required Actions A.2 and A.3 must be OR completed whenever Condition A is entered. A.1.2.1 Reduce THERMAL 4 hours ------POWER to < 50% RTP.

N F¨H not within limit. AND

A.1.2.2 Reduce Power Range 72 hours Neutron Flux – High trip setpoints to ” 55% RTP.

AND

A.2 Perform SR 3.2.2.1. 24 hours

AND

A.3 ------NOTE------THERMAL POWER does not have to be reduced to comply with this Required Action. ------

Perform SR 3.2.2.1. Prior to THERMAL POWER exceeding 50% RTP

AND

SEQUOYAH – UNIT 2 3.2.2-1 Amendment 327, N F¨H 3.2.2

ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME

Prior to THERMAL POWER exceeding 75% RTP

AND

24 hours after THERMAL POWER reaching • 95% RTP

B. Required Action and B.1 Be in MODE 2. 6 hours associated Completion Time not met.

SURVEILLANCE REQUIREMENTS

SURVEILLANCE FREQUENCY

N SR 3.2.2.1 Verify F¨H is within limits specified in the COLR. Once after each refueling prior to THERMAL POWER exceeding 75% RTP

AND

In accordance with the Surveillance Frequency Control Program

SEQUOYAH – UNIT 2 3.2.2-2 Amendment 327, QPTR 3.2.4

3.2 POWER DISTRIBUTION LIMITS

3.2.4 QUADRANT POWER TILT RATIO (QPTR)

LCO 3.2.4 7KH4375VKDOOEH” 1.02.

APPLICABILITY: MODE 1 with THERMAL POWER > 50% RTP.

ACTIONS

CONDITION REQUIRED ACTION COMPLETION TIME

A. QPTR not within limit. A.1 Reduce THERMAL 2 hours after each 32:(5• 3% from RTP for QPTR determination each 1% of QPTR > 1.02.

AND

A.2 Determine QPTR. Once per 12 hours

AND

A.3 Perform SR 3.2.1.1, 24 hours after SR 3.2.1.2, SR 3.2.1.3, achieving equilibrium SR 3.2.2.1, and SR 3.2.2.2. conditions from a THERMAL POWER reduction per and Required Action A.1

AND

Once per 7 days thereafter

AND

SEQUOYAH – UNIT 2 3.2.4-1 Amendment 327 QPTR 3.2.4

ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME

A.4 Reevaluate safety analyses Prior to increasing and confirm results remain THERMAL POWER valid for duration of operation above the limit of under this condition. Required Action A.1

AND

A.5 ------NOTES------1. Perform Required Action A.5 only after Required Action A.4 is completed.

2. Required Action A.6 shall be completed whenever Required Action A.5 is performed. ------

Normalize excore detectors to Prior to increasing restore QPTR to within limit. THERMAL POWER above the limit of Required Action A.1 AND

A.6 ------NOTE------Perform Required Action A.6 only after Required Action A.5 is completed. ------

Perform SR 3.2.1.1, Within 24 hours after SR 3.2.1.2, SR 3.2.1.3, achieving equilibrium SR 3.2.2.1, and SR 3.2.2.2. conditions at RTP not to exceed 48 hours after and increasing THERMAL POWER above the limit of Required Action A.1

SEQUOYAH – UNIT 2 3.2.4-2 Amendment 327 QPTR 3.2.4

ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME

B. Required Action and B.1 Reduce THERMAL 4 hours associated Completion POWER to ” 50% RTP. Time not met.

SURVEILLANCE REQUIREMENTS

SURVEILLANCE FREQUENCY

SR 3.2.4.1 ------NOTES------1. With input from one Power Range Neutron Flux channel inoperable and THERMAL POWER ” 75% RTP, the remaining three power range channels can be used for calculating QPTR.

2. SR 3.2.4.2 may be performed in lieu of this Surveillance. ------

Verify QPTR is within limit by calculation. In accordance with the Surveillance Frequency Control Program

SR 3.2.4.2 ------NOTE------Only required to be performed if input to QPTR from one or more Power Range Neutron Flux channels are inoperable with THERMAL POWER > 75% RTP. ------

Verify QPTR is within limit using the movable incore Once within 12 detectors. hours

AND core power distribution measurement In accordance information with the Surveillance Frequency Control Program SEQUOYAH – UNIT 2 3.2.4-3 Amendment 327 336 RTS Instrumentation 3.3.1

SURVEILLANCE REQUIREMENTS ------NOTE------Refer to Table 3.3.1-1 to determine which SRs apply for each RTS Function. ------

SURVEILLANCE FREQUENCY

SR 3.3.1.1 Perform CHANNEL CHECK. In accordance with the Surveillance Frequency Control Program

SR 3.3.1.2 ------NOTE------Not required to be performed until 12 hours after THERMAL POWER is t 15% RTP. ------

Compare results of calorimetric heat balance In accordance calculation to power range channel output. Adjust with the power range channel output if absolute difference is Surveillance > 2%. Frequency Control Program

SR 3.3.1.3 ------NOTE------Not required to be performed until 96 hours after THERMAL POWER is t 15% RTP. core power distribution ------

Compare results of the incore detector In accordance measurements to Nuclear Instrumentation System with the (NIS) AFD. Adjust NIS channel if absolute Surveillance difference is t 3%. Frequency Control Program

SR 3.3.1.4 ------NOTE------This Surveillance must be performed on the reactor trip bypass breaker prior to placing the bypass breaker in service. ------

Perform TADOT. In accordance with the Surveillance Frequency Control Program

SEQUOYAH – UNIT 2 3.3.1-9 Amendment 327 RTS Instrumentation 3.3.1

SURVEILLANCE REQUIREMENTS (continued)

SURVEILLANCE FREQUENCY

SR 3.3.1.5 Perform ACTUATION LOGIC TEST. In accordance with the Surveillance Frequency Control Program

SR 3.3.1.6 ------NOTE------Not required to be performed until 24 hours after 7+(50$/32:(5LV• 50% RTP. ------core power distribution Calibrate excore channels to agree with incore In accordance detector measurements. with the Surveillance Frequency Control Program

SR 3.3.1.7 ------NOTE------Not required to be performed for source range instrumentation prior to entering MODE 3 from MODE 2 until 4 hours after entry into MODE 3. ------

Perform COT. In accordance with the Surveillance Frequency Control Program

SEQUOYAH – UNIT 2 3.3.1-10 Amendment 327 RTS Instrumentation 3.3.1

Table 3.3.1-1 (page 7 of 9) Reactor Trip System Instrumentation

Note 2YHUWHPSHUDWXUH¨7

7KH2YHUWHPSHUDWXUH¨7)XQction Allowable Value shall not exceed the following Nominal Trip Setpoint by more than 1.9% RI¨7VSDQ

§1W S · ­ § 1W S · ½ 4 1 c c 'T ¨ ¸ 0 ® 'd KKT 21 ¨ ¸>@ 3  1 ' IfPPKTT )()( ¾ ©1W 5 S ¹ ¯ ©1W 2 S ¹ ¿

Where: ¨T is measured RCS ¨T,°F. ¨T0 LVWKHLQGLFDWHG¨7DW573ƒ) S is the Laplace transform operator, sec-1. T is the measured RCS average temperature,°F. ' T is the nominal Tavg DW573” 578.2°F.

P is the measured pressurizer pressure, psig P' is the nominal RCS operating pressure, = 2235 psig **

K1 ” 1.15 K2 • 0.011/°F K3 = 0.00055/psig W 1 • 33 sec ** W 2 ” 4 sec W 4 • 5 sec W 5 ” 3 sec

and f1 ('I) is a function such that:

(i) for qt - qb between QTNL* and QTPL* f1 ('I) = 0

* (ii) for each percent that the magnitude of (qt - qb) exceeds QTNL , the 'T nominal trip setpoint shall be automatically reduced by QTNS* of its value at RATED THERMAL POWER.

* (iii) for each percent that the magnitude of (qt - qb) exceeds QTPL , the 'T nominal trip setpoint shall be automatically reduced by QTPS* of its value at RATED THERMAL POWER.

Where qt and qb are percent RTP in the upper and lower halves of the core, respectively, and qt + qb is the total THERMAL POWER in percent RTP.

*QTNL, QTPL, QTNS, and QTPS are specified in the COLR.

The values denoted with ** are specified in the COLR.

SEQUOYAH – UNIT 2 3.3.1-20 Amendment 327 RTS Instrumentation 3.3.1

Table 3.3.1-1 (page 8 of 9) Reactor Trip System Instrumentation

Note 2YHUSRZHU¨7

7KH2YHUSRZHU¨7)XQFWLRQ$OORZDEOH9DOXHVKDOOQRWH[FHHGWKHIROORZLQJNominal Trip Setpoint by more than 1.7% RI¨7VSDQ

§1W S · ­ § W S · ½ 'T 4 'd KKT ¨ 3 ¸ ' IfTTKT )(" ¨ ¸ 0 ® 54 ¨ ¸ 6 2 ¾ ©1W 5 S ¹ ¯ ©1W 3S ¹ ¿

Where: ¨T is measured RCS ¨T,°F. ¨T0 LVWKHLQGLFDWHG¨7DW573ƒ) S is the Laplace transform operator, sec-1. T is the measured RCS average temperature,°F. " T is the nominal Tavg DW573” 578.2°F.

** " K4 ” 1.087 K5 • 0.02/°F for increasing Tavg K6 • 0.0011/°F when T > T " 0/°F for decreasing Tavg 0ƒ)ZKHQ7” T ** W 3 •10 sec W 4 • 5 sec W 5 ” 3 sec

and f2 ('I) is a function such that:

(i) for qt - qb between QPNL* and QPPL* f2 ('I) = 0

* (ii) for each percent that the magnitude of (qt - qb) exceeds QPNL , the 'T nominal trip setpoint shall be automatically reduced by QPNS* of its value at RATED THERMAL POWER.

(iii) for each percent that the magnitude of (qt - qb) exceeds QPPL*, the ǻT nominal trip setpoint shall be automatically reduced by QPPS* of its value at RATED THERMAL POWER.

Where qt and qb are percent RTP in the upper and lower halves of the core, respectively, and qt + qb is the total THERMAL POWER in percent RTP.

*QPNL, QPPL, QPNS, and QPPS are specified in the COLR.

The values denoted with ** are specified in the COLR.

SEQUOYAH – UNIT 2 3.3.1-21 Amendment 327 RCS Pressure, Temperature, and Flow DNB Limits 3.4.1

3.4 REACTOR COOLANT SYSTEM (RCS)

3.4.1 RCS Pressure, Temperature, and Flow Departure from Nucleate Boiling (DNB) Limits greater than or equal to the limit specified

in the COLR LCO 3.4.1 RCS DNB parameters for pressurizer pressure, RCS average temperature, and RCS total flow rate shall be within the limits specified below:

a. Pressurizer pressure is • 2220 psia; less than or equal to the limit b. RCS average temperature is ” 583°F; and specified in the

COLR c. 5&6WRWDOIORZUDWH• 378,400 gpm. 360,000

APPLICABILITY: MODE 1. and greater than or equal to the limit specified in the COLR ------NOTE------Pressurizer pressure limit does not apply during:

a. THERMAL POWER ramp > 5% RTP per minute;

b. THERMAL POWER step > 10% RTP;

c. PHYSICS TESTS; or

d. Performance of SR 3.1.3.2. ------

ACTIONS

CONDITION REQUIRED ACTION COMPLETION TIME

A. One or more RCS DNB A.1 Restore RCS DNB 2 hours parameters not within parameter(s) to within limit. limits.

B. Required Action and B.1 Be in MODE 2. 6 hours associated Completion Time not met.

SEQUOYAH – UNIT 2 3.4.1-1 Amendment 327 RCS Pressure, Temperature, and Flow DNB Limits 3.4.1

SURVEILLANCE REQUIREMENTS

SURVEILLANCE FREQUENCY

SR 3.4.1.1 Verify pressurizer pressure is •SVLD. In accordance with the Surveillance greater than or equal to the limit Frequency specified in the COLR Control Program

SR 3.4.1.2 Verify RCS average temperature is ”ƒ). In accordance with the less than or equal to the limit Surveillance specified in the COLR 360,000 Frequency Control Program

SR 3.4.1.3 9HULI\5&6WRWDOIORZUDWHLV• 378,400 gpm. In accordance with the Surveillance and greater than or equal to the limit Frequency specified in the COLR Control Program

SR 3.4.1.4 Verify by measurement that RCS total flow rate is In accordance • 378,400 gpm. with the 360,000 Surveillance Frequency and greater than or equal to the limit specified in the COLR Control Program

SEQUOYAH – UNIT 2 3.4.1-2 Amendment 327 Design Features 4.0

4.0 DESIGN FEATURES

4.1 Site Location

The Sequoyah Nuclear Plant is located on a site near the geographical center of Hamilton County, Tennessee, on a peninsula on the western shore of Chickamauga Lake at Tennessee River mile (TRM) 484.5. The Sequoyah site is approximately 7.5 miles northeast of the nearest city limit of Chattanooga, Tennessee, 14 miles west-northwest of Cleveland, Tennessee, and approximately 31 miles south-southwest of TVA's Watts Bar Nuclear Plant.

4.2 Reactor Core Optimized ZirloTM 4.2.1 Fuel Assemblies

The reactor shall contain 193 fuel assemblies. Each assembly shall consist of a matrix of Zircaloy or M5 clad fuel rods with an initial composition of natural or slightly enriched uranium dioxide (UO2) as fuel material. Limited substitutions of zirconium alloy or stainless steel filler rods for fuel rods, in accordance with approved applications of fuel rod configurations, may be used. Fuel assemblies shall be limited to those fuel designs that have been analyzed with applicable NRC staff approved codes and methods and shown by tests or analyses to comply with all fuel safety design bases. A limited number of lead test assemblies that have not completed representative testing may be placed in nonlimiting core regions. Sequoyah is authorized to place a limited number of lead test assemblies into the reactor as described in the Framatome-Cogema Fuels report BAW-2328, beginning with the Unit 2 Operating Cycle 10 core.

4.2.2 Control Rod Assemblies

------NOTE------Operation with 52 full length control rod assemblies (with no control rod assembly installed in core location H-08) is permitted during Cycles 24. ------52 The reactor core shall contain 53 full length and no part 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 80 percent silver, 15 percent indium, and 5 percent cadmium. All control rods shall be clad with stainless steel tubing.

4.3 Fuel Storage (with no full length control rod assembly 4.3.1 Criticality in core location H-08)

4.3.1.1 The spent fuel storage racks are designed and shall be maintained with:

a. Fuel assemblies having a maximum U-235 enrichment of 5.0 weight percent;

SEQUOYAH – UNIT 2 4.0-1 Amendment 327, 342 Reporting Requirements 5.6

5.6 Reporting Requirements

5.6.3 CORE OPERATING LIMITS REPORT

a. Core operating limits shall be established prior to each reload cycle, or prior to any remaining portion of a reload cycle, and shall be documented in the COLR for the following: 1. LCO 2.1.1, "Reactor Core Safety Limits"; 2. 1. LCO 3.1.1, "SHUTDOWN MARGIN (SDM)";

3. 2. LCO 3.1.3, "Moderator Temperature Coefficient (MTC)"; 4. LCO 3.1.4, "Rod Group Alignment Limits"; 5. 3. LCO 3.1.5, "Shutdown Bank Insertion Limits";

6. 4. LCO 3.1.6, "Control Bank Insertion Limits"; 7. LCO 3.1.8, "PHYSICS TESTS Exceptions - MODE 2"; 8. 5. LCO 3.2.1, "Heat Flux Hot Channel Factor (FQ(X, Y, Z))"; N (RAOC T(Z) Methodology) 9. 6. LCO 3.2.2, "Nuclear Enthalpy Rise Hot Channel Factor (F¨+(X,Y))";

10. 7. LCO 3.2.3, "AXIAL FLUX DIFFERENCE (AFD)"; ; 11. 8. LCO 3.3.1, "Reactor Trip System (RTS) Instrumentation," f1(¨I) limits for 2YHUWHPSHUDWXUH¨7DQGf2(¨I) limits for 2YHUSRZHU¨71RPLQDO Trip Setpoints; and 12. LCO 3.4.1, "RCS Pressure, Temperature, and Flow Departure from 13. 9. LCO 3.9.1, "Boron Concentration." Nucleate Boiling (DNB) Limits"; and

b. The analytical methods used to determine the core operating limits shall be those previously reviewed and approved by the NRC, specifically those described in the following documents:

Add 1. BAW-10180-A, Revision 1, "NEMO - Nodal Expansion Method Insert A Optimized," March 1993;

2. BAW-10169P-A, Revision 0, "RSG Plant Safety Analysis - B&W Safety Analysis Methodology for Recirculating Steam Generator Plants," October 1989;

3. BAW-10163P-A, Revision 0, "Core Operating Limit Methodology for Westinghouse-Designed PWRs," June 1989;

SEQUOYAH – UNIT 2 5.6-2 Amendment 327 Reporting Requirements 5.6

5.6 Reporting Requirements

5.6.3 CORE OPERATING LIMITS REPORT (continued)

4. EMF-2328(P)(A), "PWR Small Break LOCA Evaluation Model," March 2001;

5. BAW-10227P-A, Revision 1, "Evaluation of Advanced Cladding and Structural Material (M5) in PWR Reactor Fuel," June 2003;

6. BAW-10186P-A, Revision 2, "Extended Burnup Evaluation," June 2003;

7. EMF-2103P-A, Revision 0, "Realistic Large Break LOCA Methodology for Pressurized Water Reactors," April 2003;

8. BAW-10241P-A, Revision 1, "BHTP DNB Correlation Applied with LYNXT," July 2005;

9. BAW-10199P-A, Revision 0, "The BWU Critical Heat Flux Correlations," August 1996;

10. BAW-10189P-A, "CHF Testing and Analysis of the Mark-BW Fuel Assembly Design," January 1996;

11. BAW-10159P-A, "BWCMV Correlation of Critical Heat Flux in Mixing Vane Grid Fuel Assemblies," August 1990; and

12. BAW-10231P-A, Revision 1, "COPERNIC Fuel Rod Design Computer Code" January 2004.

c. The core operating limits shall be determined such that all applicable limits (e.g., fuel thermal mechanical limits, core thermal hydraulic limits, Emergency Core Cooling Systems (ECCS) limits, nuclear limits such as SDM, transient analysis limits, and accident analysis limits) of the safety analysis are met.

d. The COLR, including any midcycle revisions or supplements, shall be provided within 30 days of issuance for each reload cycle to the NRC.

SEQUOYAH – UNIT 2 5.6-3 Amendment 327 INSERT A

1. WCAP-8745-P-$³'HVLJQ%DVHVIRUWKH7KHUPDO2YHUSRZHU¨7DQG7KHUPDO 2YHUWHPSHUDWXUH¨77ULS)XQFWLRQV´6HSWHPEHU;

2. WCAP-9272-P-A, “Westinghouse Reload Safety Evaluation Methodology,” July 1985;

3. WCAP-10216-P-A, Revision 1A, “Relaxation of Constant Axial Offset Control – FQ Surveillance Technical Specification,” February 1994;

4. WCAP-10444-P-A, “Reference Core Report VANTAGE 5 Fuel Assembly,” September 1985;

5. WCAP-10444-P-A Addendum 2-A, “VANTAGE 5H Fuel Assembly,” February 1989;

6. WCAP-10965-P-A, “ANC: A Westinghouse Advanced Nodal Computer Code,” September 1986;

7. WCAP-10965-P-A, Addendum 2-A, Revision 0, “Qualification of the New Pin Power Recovery Methodology,” September 2010;

8. WCAP-11397-P-A, “Revised Thermal Design Procedure,” April 1989;

9. WCAP-12610-P-A, “VANTAGE+ Fuel Assembly Reference Core Report,” April 1995;

10. WCAP-12610-P-A & CENPD-404-P-A, Addendum 1-A, “Optimized ZIRLOTM,” July 2006;

11. WCAP-14565-P-A, “VIPRE-01 Modeling and Qualification for Pressurized Water Reactor Non-LOCA Thermal-Hydraulic Safety Analysis,” October 1999;

12. WCAP-14565-P-A, Addendum 1-A, Revision 0, “Addendum 1 to WCAP 14565-P-A Qualification of ABB-NV Critical Heat Flux Correlations with VIPRE-01 Code,” August 2004;

13. WCAP-14565-P-A, Addendum 2-P-A, Revision 0, “Addendum 2 to WCAP-14565-P-A Extended Application of ABB-NV Correlation and Modified ABB-NV Correlation WLOP for PWR Low Pressure Applications,” April 2008;

14. WCAP-15025-P-A, “Modified WRB-2 Correlation, WRB-2M, for Predicting Critical Heat Flux in 17x17 Rod Bundles with Modified LPD Mixing Vane Grids,” April 1999;

15. WCAP-16045-P-A, “Qualification of the Two-Dimensional Transport Code PARAGON,” August 2004;

16. WCAP-16045-P-A, Addendum 1-A, “Qualification of the NEXUS Nuclear Data Methodology,” August 2007;

17. WCAP-16996-P-A, Revision 1, “Realistic LOCA Evaluation Methodology Applied to the Full Spectrum of Break Sizes (FULL SPECTRUM LOCA Methodology),” November 2016; and

18. WCAP-17661-P-A, Revision 1, "Improved RAOC and CAOC FQ Surveillance Technical Specifications," February 2019.

Enclosure 1

Evaluation of the Transition to Westinghouse RFA-2 Fuel

ATTACHMENT 3

Proposed TS Changes (Final Typed) for SQN Unit 1

CNL-20-014 - 11-

F. Post Accident Sampling (Section 22.3, II.B.3)

This condition has been deleted.

H. Instruments for Inadequate Core Cooling (Section 22.3, II.F.2)

(1) By January 1, 1982, TVA shall install a backup indication for incore thermocouples. This display shall be in the control room and cover the temperature range of 200 F - 2000 F.

(2) At the first outage of sufficient duration but no later than startup following the second refueling outage, TVA shall install reactor vessel water level instrumentation which meets NRC requirements.

I. Upgrade Emergency Support Facilities (Section 22.3, II.A.1.2)

(1) At the first outage of sufficient duration, but no later than startup following the second refueling outage, TVA shall update the Technical Support Facilities to meet NRC requirements.

(2) TVA shall maintain interim emergency support facilities (Technical Support Center, Operations Support Center and the Emergency Operations Facility) until the final facilities are complete.

J. Relief and Safety Valve Test Requirements (Section 22.2, II.D.1)

TVA shall conform to the results of the EPRI test program. TVA shall provide documentation for qualifying (a) reactor coolant system relief and safety valves, (b) piping and supports, and (c) block valves in accordance with the review schedule given in SECY 81-491 as approved by the Commission.

(24) Compliance with Regulatory Guide 1.97

TVA shall implement modifications necessary to comply with Revision 2 of Regulatory Guide 1.97, "Instrumentation for Light Water Cooled Nuclear Power Plants to Assess Plant Conditions During and Following An Accident," dated December 1980 by startup from the Unit 2 Cycle 4 refueling outage.

(25) Transition Core Peaking Penalties

When Framatome HTP fuel assemblies are co-resident with the Westinghouse RFA-2 fuel assemblies: N (a) The HTP fuel assemblies FοH shall be maintained less than 1.61; (b) The RFA-2 fuel assemblies DNBR limit shall be reduced by: 1. 0.25% for the WRB-2M critical heat flux correlation 2. 0.50% for the ABB-NV critical heat flux correlation

Renewed License No. DPR 77 XXXXXX, XX XXXX

TABLE OF CONTENTS Page

1.0 USE AND APPLICATION 1.1 Definitions ...... 1.1-1 1.2 Logical Connectors ...... 1.2-1 1.3 Completion Times ...... 1.3-1 1.4 Frequency ...... 1.4-1

2.0 SAFETY LIMITS (SLs) ...... 2.0-1 2.1 SLs 2.2 SL Violations

3.0 LIMITING CONDITION FOR OPERATION (LCO) APPLICABILITY ...... 3.0-1 3.0 SURVEILLANCE REQUIREMENT (SR) APPLICABILITY ...... 3.0-4

3.1 REACTIVITY CONTROL SYSTEMS 3.1.1 SHUTDOWN MARGIN (SDM) ...... 3.1.1-1 3.1.2 Core Reactivity ...... 3.1.2-1 3.1.3 Moderator Temperature Coefficient (MTC) ...... 3.1.3-1 3.1.4 Rod Group Alignment Limits ...... 3.1.4-1 3.1.5 Shutdown Bank Insertion Limits ...... 3.1.5-1 3.1.6 Control Bank Insertion Limits ...... 3.1.6-1 3.1.7 Rod Position Indication ...... 3.1.7-1 3.1.8 PHYSICS TESTS Exceptions - MODE 2 ...... 3.1.8-1

3.2 POWER DISTRIBUTION LIMITS 3.2.1 Heat Flux Hot Channel Factor (FQ(Z)) (RAOC-T(Z) Methodology) ...... 3.2.1-1 N 3.2.2 Nuclear Enthalpy Rise Hot Channel Factor (F ¨H) ...... 3.2.2-1 3.2.3 AXIAL FLUX DIFFERENCE (AFD) ...... 3.2.3-1 3.2.4 QUADRANT POWER TILT RATIO (QPTR) ...... 3.2.4-1

3.3 INSTRUMENTATION 3.3.1 Reactor Trip System (RTS) Instrumentation ...... 3.3.1-1 3.3.2 Engineered Safety Feature Actuation System (ESFAS) Instrumentation ...... 3.3.2-1 3.3.3 Post Accident Monitoring (PAM) Instrumentation ...... 3.3.3-1 3.3.4 Remote Shutdown Monitoring Instrumentation ...... 3.3.4-1 3.3.5 Loss of Power (LOP) Diesel Generator (DG) Start Instrumentation ...... 3.3.5-1 3.3.6 Containment Ventilation Isolation Instrumentation ...... 3.3.6-1 3.3.7 Control Room Emergency Ventilation System (CREVS) Actuation Instrumentation ...... 3.3.7-1 3.3.8 Auxiliary Building Gas Treatment System (ABGTS) Actuation Instrumentation ...... 3.3.8-1 3.3.9 Boron Dilution Monitoring Instrumentation (BDMI) ...... 3.3.9-1

3.4 REACTOR COOLANT SYSTEM (RCS) 3.4.1 RCS Pressure, Temperature, and Flow Departure from Nucleate Boiling (DNB) Limits ...... 3.4.1-1 3.4.2 RCS Minimum Temperature for Criticality ...... 3.4.2-1 3.4.3 RCS Pressure and Temperature (P/T) Limits ...... 3.4.3-1 3.4.4 RCS Loops - MODES 1 and 2 ...... 3.4.4-1

SEQUOYAH - UNIT 1 i Amendment 334, 2.0 SAFETY LIMITS (SLs)

2.1 SLs

2.1.1 Reactor Core SLs

In MODES 1 and 2, the combination of THERMAL POWER, Reactor Coolant System (RCS) highest loop average temperature, and pressurizer pressure shall not exceed the limits specified in the COLR; and the following SLs shall not be exceeded:

2.1.1.1 The departure from nucleate boiling ratio (DNBR) shall be maintained • 1.14 for the WRB-2M correlation.

2.1.1.2 The maximum local fuel pin centerline temperature shall be maintained < 5080°F, decreasing by 9°F per 10,000 MWD/MTU of burnup.

2.1.2 Reactor Coolant System Pressure SL

In MODES 1, 2, 3, 4, and 5, the RCS pressure shall be maintained ” 2735 psig.

2.2 SAFETY LIMIT VIOLATIONS

2.2.1 If SL 2.1.1 is violated, restore compliance and be in MODE 3 within 1 hour.

2.2.2 If SL 2.1.2 is violated:

2.2.2.1 In MODE 1 or 2, restore compliance and be in MODE 3 within 1 hour.

2.2.2.2 In MODE 3, 4, or 5, restore compliance within 5 minutes.

SEQUOYAH – UNIT 1 2.0-1 Amendment 334 Rod Group Alignment Limits 3.1.4

ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME

B.2.1.2 Initiate boration to restore 1 hour SDM to within limit.

AND

B.2.2 Reduce THERMAL 2 hours POWER to ” 75% RTP.

AND

B.2.3 Verify SDM is within the Once per limits specified in the 12 hours COLR.

AND

B.2.4 Perform SR 3.2.1.1 and 72 hours SR 3.2.1.2.

AND

B.2.5 Perform SR 3.2.2.1. 72 hours

AND

B.2.6 Re-evaluate safety 5 days analyses and confirm results remain valid for duration of operation under these conditions.

C. Required Action and C.1 Be in MODE 3. 6 hours associated Completion Time of Condition B not met.

D. More than one rod not D.1.1 Verify SDM is within the 1 hour within alignment limit. limits specified in the COLR.

OR

SEQUOYAH – UNIT 1 3.1.4-2 Amendment 334, Rod Position Indication 3.1.7

3.1 REACTIVITY CONTROL SYSTEMS

3.1.7 Rod Position Indication

LCO 3.1.7 The Rod Position Indication System and the Demand Position Indication System shall be OPERABLE.

APPLICABILITY: MODES 1 and 2.

ACTIONS ------NOTES------1. Separate Condition entry is allowed for each inoperable rod position indicator and each demand position indicator.

2. LCO 3.0.4.a and b are not applicable for Required Actions A.2.1 and A.2.2 following a startup from a refueling outage, or following entry into MODE 5 of sufficient duration to safely repair an inoperable rod position indication. ------

CONDITION REQUIRED ACTION COMPLETION TIME

A. One rod position A.1 Verify the position of the Once per 12 hours indicator per bank rods with inoperable inoperable. position indicators indirectly by using core power distribution measurement information.

OR

------NOTE------Required Actions A.2.1 and A.2.2 may only be applied to one inoperable rod position indicator. ------8 hours A.2.1 Verify position of the rod with inoperable AND position indicator indirectly by using core power distribution measurement information.

SEQUOYAH – UNIT 1 3.1.7-1 Amendment 334, Rod Position Indication 3.1.7

ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME

B. More than one rod B.1 Place the control rods Immediately position indicator per under manual control. bank inoperable. AND

B.2 Monitor and record Reactor Once per 1 hour Coolant System Tavg.

AND

B.3 Verify the position of the Once per 12 hours rods with inoperable position indicators indirectly by using core power distribution measurement information.

AND 24 hours B.4 Restore inoperable position indicators to OPERABLE status such that a maximum of one rod position indicator per bank is inoperable.

C. One or more rods with C.1 Verify the position of the Immediately inoperable position rods with inoperable indicators have been position indicators indirectly moved in excess of 24 by using core power steps in one direction distribution measurement since the last information. determination of the rod’s position. OR 8 hours C.2 Reduce THERMAL POWER to < 50% RTP.

SEQUOYAH – UNIT 1 3.1.7-3 Amendment 334, FQ(Z) (RAOC-T(Z) Methodology) 3.2.1

3.2 POWER DISTRIBUTION LIMITS

3.2.1 Heat Flux Hot Channel Factor (FQ(Z)) (RAOC-T(Z) Methodology)

C W LCO 3.2.1 FQ(Z), as approximated by FQ(Z) and FQ (Z), shall be within the limits specified in the COLR.

APPLICABILITY: MODE 1.

ACTIONS

CONDITION REQUIRED ACTION COMPLETION TIME

A. ------NOTE------A.1 Reduce THERMAL 15 minutes after each Required Action A.4 C POWER • 1% RTP for FQ(Z) determination shall be completed C each 1% FQ(Z) exceeds whenever this Condition limit. is entered prior to increasing THERMAL AND POWER above the limit of Required Action A.1. A.2 Reduce Power Range 72 hours after each SR 3.2.1.2 is not C Neutron Flux – High trip F (Z) determination required to be Q setpoints • 1% for performed if this each 1% that THERMAL Condition is entered POWER is limited below prior to THERMAL RTP by Required POWER exceeding Action A.1. 75% RTP after a

refueling. AND ------

A.3 Reduce Overpower ¨T trip FC(Z) not within limit. 72 hours after each Q setpoints • 1% for each 1% C FQ(Z) determination that THERMAL POWER is limited below RTP by Required Action A.1.

AND

A.4 Perform SR 3.2.1.1 and Prior to increasing SR 3.2.1.2. THERMAL POWER above the limit of Required Action A.1

SEQUOYAH – UNIT 1 3.2.1-1 Amendment 334, FQ(Z) (RAOC-T(Z) Methodology) 3.2.1

ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME

W B. FQ (Z) not within limits B.1.1 Implement a RAOC 4 hours operating space specified in the COLR that restores W FQ (Z) to within its limits.

AND

B.1.2 Perform SR 3.2.1.1 and 72 hours SR 3.2.1.2 if control rod motion is required to comply with the new operating space.

OR

B.2.1 ------NOTE------Required Action B.2.4 shall be completed whenever Required Action B.2.1 is performed prior to increasing THERMAL POWER above the limit of Required Action B.2.1. ------

Limit allowable THERMAL 4 hours after each W POWER and AFD limits as FQ (Z) determination specified in the COLR.

AND

B.2.2 Limit Power Range 72 hours after each W Neutron Flux - High trip FQ (Z) determination setpoints • 1% for each 1% that THERMAL POWER is limited below RTP by Required Action B.2.1.

AND

SEQUOYAH – UNIT 1 3.2.1-2 Amendment 334, FQ(Z) (RAOC-T(Z) Methodology) 3.2.1

CONDITION REQUIRED ACTION COMPLETION TIME

B.2.3 Limit Overpower ¨T trip 72 hours after each W setpoints • 1% for each 1% FQ (Z) determination that THERMAL POWER is limited below RTP by Required Action B.2.1.

AND

B.2.4 Perform SR 3.2.1.1 and SR 3.2.1.2. Prior to increasing THERMAL POWER above the limit of Required Action B.2.1

C. Required Action and C.1 Be in MODE 2. 6 hours associated Completion Time not met.

SURVEILLANCE REQUIREMENTS

SURVEILLANCE FREQUENCY

C SR 3.2.1.1 Verify FQ(Z) is within limit. Once after each refueling prior to THERMAL POWER exceeding 75% RTP

AND

Once within 24 hours after achieving equilibrium conditions after exceeding, by • 10% RTP, the THERMAL

SEQUOYAH – UNIT 1 3.2.1-3 Amendment 334, FQ(Z) (RAOC-T(Z) Methodology) 3.2.1

SURVEILLANCE REQUIREMENTS (continued)

SURVEILLANCE FREQUENCY

POWER at which C FQ(Z) was last verified

AND

In accordance with the Surveillance Frequency Control Program

W SR 3.2.1.2 Verify FQ (Z) is within limit. Once after each refueling within 24 hours after THERMAL POWER exceeds 75% RTP

AND

Once within 24 hours after achieving equilibrium conditions after exceeding, by • 10% RTP, the THERMAL POWER at which W FQ (Z) was last verified

AND

In accordance with the Surveillance Frequency Control Program

SEQUOYAH – UNIT 1 3.2.1-4 Amendment 334, N F¨H 3.2.2

3.2 POWER DISTRIBUTION LIMITS

N 3.2.2 Nuclear Enthalpy Rise Hot Channel Factor (F¨H)

N LCO 3.2.2 F¨H shall be within the limits specified in the COLR.

APPLICABILITY: MODE 1.

ACTIONS

CONDITION REQUIRED ACTION COMPLETION TIME

N A. ------NOTE------A.1.1 Restore F¨H to within limit. 4 hours Required Actions A.2 and A.3 must be OR completed whenever Condition A is entered. A.1.2.1 Reduce THERMAL 4 hours ------POWER to < 50% RTP.

N F¨H not within limit. AND

A.1.2.2 Reduce Power Range 72 hours Neutron Flux – High trip setpoints to ” 55% RTP.

AND

A.2 Perform SR 3.2.2.1. 24 hours

AND

A.3 ------NOTE------THERMAL POWER does not have to be reduced to comply with this Required Action. ------

Perform SR 3.2.2.1. Prior to THERMAL POWER exceeding 50% RTP

AND

SEQUOYAH – UNIT 1 3.2.2-1 Amendment 334, N F¨H 3.2.2

ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME

Prior to THERMAL POWER exceeding 75% RTP

AND

24 hours after THERMAL POWER reaching • 95% RTP

B. Required Action and B.1 Be in MODE 2. 6 hours associated Completion Time not met.

SURVEILLANCE REQUIREMENTS

SURVEILLANCE FREQUENCY

N SR 3.2.2.1 Verify F¨H is within limits specified in the COLR. Once after each refueling prior to THERMAL POWER exceeding 75% RTP

AND

In accordance with the Surveillance Frequency Control Program

SEQUOYAH – UNIT 1 3.2.2-2 Amendment 334, QPTR 3.2.4

3.2 POWER DISTRIBUTION LIMITS

3.2.4 QUADRANT POWER TILT RATIO (QPTR)

LCO 3.2.4 The QPTR shall be ” 1.02.

APPLICABILITY: MODE 1 with THERMAL POWER > 50% RTP.

ACTIONS

CONDITION REQUIRED ACTION COMPLETION TIME

A. QPTR not within limit. A.1 Reduce THERMAL 2 hours after each POWER • 3% from RTP QPTR determination for each 1% of QPTR > 1.02.

AND

A.2 Determine QPTR. Once per 12 hours

AND

A.3 Perform SR 3.2.1.1, 24 hours after SR 3.2.1.2, and achieving equilibrium SR 3.2.2.1. conditions from a THERMAL POWER reduction per Required Action A.1

AND

Once per 7 days thereafter

AND

SEQUOYAH – UNIT 1 3.2.4-1 Amendment 334, QPTR 3.2.4

ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME

A.4 Reevaluate safety Prior to increasing analyses and confirm THERMAL POWER results remain valid for above the limit of duration of operation under Required Action A.1 this condition.

AND

A.5 ------NOTES------1. Perform Required Action A.5 only after Required Action A.4 is completed.

2. Required Action A.6 shall be completed whenever Required Action A.5 is performed. ------

Normalize excore detectors Prior to increasing to restore QPTR to within THERMAL POWER limit. above the limit of Required Action A.1

AND

A.6 ------NOTE------Perform Required Action A.6 only after Required Action A.5 is completed. ------

Perform SR 3.2.1.1, SR 3.2.1.2, and Within 24 hours after SR 3.2.2.1. achieving equilibrium conditions at RTP not to exceed 48 hours after increasing THERMAL POWER above the limit of Required Action A.1

SEQUOYAH – UNIT 1 3.2.4-2 Amendment 334, QPTR 3.2.4

ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME

B. Required Action and B.1 Reduce THERMAL 4 hours associated Completion POWER to ” 50% RTP. Time not met.

SURVEILLANCE REQUIREMENTS

SURVEILLANCE FREQUENCY

SR 3.2.4.1 ------NOTES------1. With input from one Power Range Neutron Flux channel inoperable and THERMAL POWER ” 75% RTP, the remaining three power range channels can be used for calculating QPTR.

2. SR 3.2.4.2 may be performed in lieu of this Surveillance. ------

Verify QPTR is within limit by calculation. In accordance with the Surveillance Frequency Control Program

SR 3.2.4.2 ------NOTE------Only required to be performed if input to QPTR from one or more Power Range Neutron Flux channels are inoperable with THERMAL POWER > 75% RTP. ------

Verify QPTR is within limit using core power Once within 12 distribution measurement information. hours

AND

In accordance with the Surveillance Frequency Control Program

SEQUOYAH – UNIT 1 3.2.4-3 Amendment 334, 343, RTS Instrumentation 3.3.1

SURVEILLANCE REQUIREMENTS ------NOTE------Refer to Table 3.3.1-1 to determine which SRs apply for each RTS Function. ------

SURVEILLANCE FREQUENCY

SR 3.3.1.1 Perform CHANNEL CHECK. In accordance with the Surveillance Frequency Control Program

SR 3.3.1.2 ------NOTE------Not required to be performed until 12 hours after THERMAL POWER is t 15% RTP. ------

Compare results of calorimetric heat balance In accordance calculation to power range channel output. Adjust with the power range channel output if absolute difference is Surveillance > 2%. Frequency Control Program

SR 3.3.1.3 ------NOTE------Not required to be performed until 96 hours after THERMAL POWER is t 15% RTP. ------

Compare results of the core power distribution In accordance measurements to Nuclear Instrumentation System with the (NIS) AFD. Adjust NIS channel if absolute Surveillance difference is t 3%. Frequency Control Program

SR 3.3.1.4 ------NOTE------This Surveillance must be performed on the reactor trip bypass breaker prior to placing the bypass breaker in service. ------

Perform TADOT. In accordance with the Surveillance Frequency Control Program

SEQUOYAH – UNIT 1 3.3.1-9 Amendment 334, RTS Instrumentation 3.3.1

SURVEILLANCE REQUIREMENTS (continued)

SURVEILLANCE FREQUENCY

SR 3.3.1.5 Perform ACTUATION LOGIC TEST. In accordance with the Surveillance Frequency Control Program

SR 3.3.1.6 ------NOTE------Not required to be performed until 24 hours after THERMAL POWER is • 50% RTP. ------

Calibrate excore channels to agree with core power In accordance distribution measurements. with the Surveillance Frequency Control Program

SR 3.3.1.7 ------NOTE------Not required to be performed for source range instrumentation prior to entering MODE 3 from MODE 2 until 4 hours after entry into MODE 3. ------

Perform COT. In accordance with the Surveillance Frequency Control Program

SEQUOYAH – UNIT 1 3.3.1-10 Amendment 334, RTS Instrumentation 3.3.1

Table 3.3.1-1 (page 7 of 9) Reactor Trip System Instrumentation

NoteU 1: Overtemperature ¨T

The Overtemperature ¨T Function Allowable Value shall not exceed the following Nominal Trip Setpoint by more than 1.9% of ¨T span.

§1W S · ­ § 1W S · ½ 4 1 c c 'T ¨ ¸ 0 ® 'd KKT 21 ¨ ¸>@ 3  1 ' IfPPKTT )()( ¾ ©1W 5 S ¹ ¯ ©1W 2 S ¹ ¿

Where: ¨T is measured RCS ¨T,°F.

¨TR0R is the indicated ¨T at RTP,°F. -1 S is the Laplace transform operator, secP .P T is the measured RCS average temperature,°F. ' TP P is the nominal TRavgR at RTP, ” **°F.

P is the measured pressurizer pressure, psig ' PP P is the nominal RCS operating pressure, = ** psig

KR1R ” ** KR2R • **/°F KR3R = **/psig W1 • ** sec W2 ” ** sec W4 • ** sec W5 ” ** sec

and fR1R ('I) is a function such that:

(i) for qRtR - qRbR between QTNL* and QTPL* fR1R ('I) = 0

* (ii) for each percent that the magnitude of (qRtR - qRbR) exceeds QTNLP ,P the 'T nominal * trip setpoint shall be automatically reduced by QTNSP P of its value at RATED THERMAL POWER.

* (iii) for each percent that the magnitude of (qRtR - qRbR) exceeds QTPLP ,P the 'T nominal * trip setpoint shall be automatically reduced by QTPSP P of its value at RATED THERMAL POWER.

Where qRtR and qRbR are percent RTP in the upper and lower halves of the core,

respectively, and qRtR + qRbR is the total THERMAL POWER in percent RTP.

*QTNL, QTPL, QTNS, and QTPS are specified in the COLR.

The values denoted with ** are specified in the COLR.

SEQUOYAH – UNIT 1 3.3.1-20 Amendment 334, RTS Instrumentation 3.3.1

Table 3.3.1-1 (page 8 of 9) Reactor Trip System Instrumentation

NoteU 2: Overpower ¨T

The Overpower ¨T Function Allowable Value shall not exceed the following Nominal Trip Setpoint by more than 1.7% of ¨T span.

§ 1  W S · ­ § W S · ½ ' T 4 'd KKT ¨ 3 ¸ ' IfTTKT )(" ¨ ¸ 0 ® 54 ¨ ¸ 6 2 ¾ © 1  W 5 S ¹ ¯ © 1W 3 S ¹ ¿

Where: ¨T is measured RCS ¨T,°F.

¨TR0R is the indicated ¨T at RTP,°F. -1 S is the Laplace transform operator, secP .P T is the measured RCS average temperature,°F. " TP P is the nominal TRavgR at RTP, ” **°F.

" KR4R ” ** KR5R • **/°F for increasing TRavgR KR6R • **/°F when T > TP " **/°F for decreasing TRavgR **/°F when T ” TP W3 • ** sec W 4 • ** sec W5 ” ** sec

and fR2R ('I) is a function such that:

(i) for qRtR - qRbR between QPNL* and QPPL* fR2R ('I) = 0

* (ii) for each percent that the magnitude of (qRtR - qRbR) exceeds QPNLP ,P the 'T nominal trip * setpoint shall be automatically reduced by QPNSP P of its value at RATED THERMAL POWER.

(iii) for each percent that the magnitude of (qRtR - qRbR) exceeds QPPL*, the 'T nominal trip setpoint shall be automatically reduced by QPPS* of its value at RATED THERMAL POWER.

Where qRtR and qRbR are percent RTP in the upper and lower halves of the core, respectively, and

qRtR + qRbR is the total THERMAL POWER in percent RTP.

*QPNL, QPPL, QPNS, and QPPS are specified in the COLR.

The values denoted with ** are specified in the COLR.

SEQUOYAH – UNIT 1 3.3.1-21 Amendment 334, RCS Pressure, Temperature, and Flow DNB Limits 3.4.1

3.4 REACTOR COOLANT SYSTEM (RCS)

3.4.1 RCS Pressure, Temperature, and Flow Departure from Nucleate Boiling (DNB) Limits

LCO 3.4.1 RCS DNB parameters for pressurizer pressure, RCS average temperature, and RCS total flow rate shall be within the limits specified below:

a. Pressurizer pressure is greater than or equal to the limit specified in the COLR;

b. RCS average temperature is less than or equal to the limit specified in the COLR; and

c. RCS total flow rate • 360,000 gpm and greater than or equal to the limit specified in the COLR.

APPLICABILITY: MODE 1.

------NOTE------Pressurizer pressure limit does not apply during:

a. THERMAL POWER ramp > 5% RTP per minute;

b. THERMAL POWER step > 10% RTP;

c. PHYSICS TESTS; or

d. Performance of SR 3.1.3.2. ------

ACTIONS

CONDITION REQUIRED ACTION COMPLETION TIME

A. One or more RCS DNB A.1 Restore RCS DNB 2 hours parameters not within parameter(s) to within limit. limits.

B. Required Action and B.1 Be in MODE 2. 6 hours associated Completion Time not met.

SEQUOYAH – UNIT 1 3.4.1-1 Amendment 334, RCS Pressure, Temperature, and Flow DNB Limits 3.4.1

SURVEILLANCE REQUIREMENTS

SURVEILLANCE FREQUENCY

SR 3.4.1.1 Verify pressurizer pressure is greater than or equal In accordance to the limit specified in the COLR. with the Surveillance Frequency Control Program

SR 3.4.1.2 Verify RCS average temperature is less than or In accordance equal to the limit specified in the COLR. with the Surveillance Frequency Control Program

SR 3.4.1.3 Verify RCS total flow rate is • 360,000 gpm and In accordance greater than or equal to the limit specified in the with the COLR. Surveillance Frequency Control Program

SR 3.4.1.4 Verify by measurement that RCS total flow rate is In accordance • 360,000 gpm and greater than or equal to the limit with the specified in the COLR. Surveillance Frequency Control Program

SEQUOYAH – UNIT 1 3.4.1-2 Amendment 334, Design Features 4.0

4.0 DESIGN FEATURES

4.1 Site Location

The Sequoyah Nuclear Plant is located on a site near the geographical center of Hamilton County, Tennessee, on a peninsula on the western shore of Chickamauga Lake at Tennessee River mile (TRM) 484.5. The Sequoyah site is approximately 7.5 miles northeast of the nearest city limit of Chattanooga, Tennessee, 14 miles west-northwest of Cleveland, Tennessee, and approximately 31 miles south-southwest of TVA's Watts Bar Nuclear Plant.

4.2 Reactor Core

4.2.1 Fuel Assemblies

The reactor shall contain 193 fuel assemblies. Each assembly shall consist of a matrix of Optimized ZirloTM, Zircaloy or M5 clad fuel rods with an initial composition of natural or slightly enriched uranium dioxide (UO2) as fuel material. Limited substitutions of zirconium alloy or stainless steel filler rods for fuel rods, in accordance with approved applications of fuel rod configurations, may be used. Fuel assemblies shall be limited to those fuel designs that have been analyzed with applicable NRC staff approved codes and methods and shown by tests or analyses to comply with all fuel safety design bases. A limited number of lead test assemblies that have not completed representative testing may be placed in nonlimiting core regions.

4.2.2 Control Rod Assemblies

The reactor core shall contain 52 full length and no part length control rod assemblies (with no full length control rod assembly in core location H-08). The full length control rod assemblies shall contain a nominal 142 inches of absorber material. The nominal values of absorber material shall be 80 percent silver, 15 percent indium, and 5 percent cadmium. All control rods shall be clad with stainless steel tubing.

4.3 Fuel Storage

4.3.1 Criticality

4.3.1.1 The spent fuel storage racks are designed and shall be maintained with:

a. Fuel assemblies having a maximum U-235 enrichment of 5.0 weight percent;

SEQUOYAH – UNIT 1 4.0-1 Amendment 334, 348, Reporting Requirements 5.6

5.6 Reporting Requirements

5.6.3 CORE OPERATING LIMITS REPORT

a. Core operating limits shall be established prior to each reload cycle, or prior to any remaining portion of a reload cycle, and shall be documented in the COLR for the following:

1. LCO 2.1.1, “Reactor Core Safety Limits”;

2. LCO 3.1.1, "SHUTDOWN MARGIN (SDM)";

3. LCO 3.1.3, "Moderator Temperature Coefficient (MTC)";

4. LCO 3.1.4, “Rod Group Alignment Limits”;

5. LCO 3.1.5, "Shutdown Bank Insertion Limits";

6. LCO 3.1.6, "Control Bank Insertion Limits";

7. LCO 3.1.8, “PHYSICS TESTS Exceptions – MODE 2”;

8. LCO 3.2.1, "Heat Flux Hot Channel Factor (FQ(Z)) (RAOC-T(Z) Methodology)";

N 9. LCO 3.2.2, "Nuclear Enthalpy Rise Hot Channel Factor (F¨H)";

10. LCO 3.2.3, "AXIAL FLUX DIFFERENCE (AFD)";

11. LCO 3.3.1, "Reactor Trip System (RTS) Instrumentation";

12. LCO 3.4.1, “RCS Pressure, Temperature, and Flow Departure from Nucleate Boiling (DNB) Limits”; and

13. LCO 3.9.1, "Boron Concentration."

b. The analytical methods used to determine the core operating limits shall be those previously reviewed and approved by the NRC, specifically those described in the following documents:

1. WCAP-8745-P-A, “Design Bases for the Thermal Overpower ¨T and Thermal Overtemperature ¨T Trip Functions,” September 1986;

2. WCAP-9272-P-A, “Westinghouse Reload Safety Evaluation Methodology,” July 1985;

3. WCAP-10216-P-A, Revision 1A, “Relaxation of Constant Axial Offset Control – FQ Surveillance Technical Specification,” February 1994;

SEQUOYAH – UNIT 1 5.6-2 Amendment 334, Reporting Requirements 5.6

5.6 Reporting Requirements

5.6.3 CORE OPERATING LIMITS REPORT (continued)

4. WCAP-10444-P-A, “Reference Core Report VANTAGE 5 Fuel Assembly,” September 1985;

5. WCAP-10444-P-A Addendum 2-A, “VANTAGE 5H Fuel Assembly,” February 1989;

6. WCAP-10965-P-A, “ANC: A Westinghouse Advanced Nodal Computer Code,” September 1986;

7. WCAP-10965-P-A, Addendum 2-A, Revision 0, “Qualification of the New Pin Power Recovery Methodology,” September 2010;

8. WCAP-11397-P-A, “Revised Thermal Design Procedure,” April 1989;

9. WCAP-12610-P-A, “VANTAGE+ Fuel Assembly Reference Core Report,” April 1995;

10. WCAP-12610-P-A & CENPD-404-P-A, Addendum 1-A, “Optimized ZIRLOTM,” July 2006;

11. WCAP-14565-P-A, “VIPRE-01 Modeling and Qualification for Pressurized Water Reactor Non-LOCA Thermal-Hydraulic Safety Analysis,” October 1999;

12. WCAP-14565-P-A, Addendum 1-A, Revision 0, “Addendum 1 to WCAP 14565-P-A Qualification of ABB-NV Critical Heat Flux Correlations with VIPRE-01 Code,” August 2004;

13. WCAP-14565-P-A, Addendum 2-P-A, Revision 0, “Addendum 2 to WCAP-14565-P-A Extended Application of ABB-NV Correlation and Modified ABB-NV Correlation WLOP for PWR Low Pressure Applications,” April 2008;

14. WCAP-15025-P-A, “Modified WRB-2 Correlation, WRB-2M, for Predicting Critical Heat Flux in 17x17 Rod Bundles with Modified LPD Mixing Vane Grids,” April 1999;

15. WCAP-16045-P-A, “Qualification of the Two-Dimensional Transport Code PARAGON,” August 2004;

16. WCAP-16045-P-A, Addendum 1-A, “Qualification of the NEXUS Nuclear Data Methodology,” August 2007;

17. WCAP-16996-P-A, Revision 1, “Realistic LOCA Evaluation Methodology Applied to the Full Spectrum of Break Sizes (FULL SPECTRUM LOCA Methodology),” November 2016; and

SEQUOYAH – UNIT 1 5.6-3 Amendment 334, Reporting Requirements 5.6

5.6 Reporting Requirements

5.6.3 CORE OPERATING LIMITS REPORT (continued)

18. WCAP-17661-P-A, Revision 1, "Improved RAOC and CAOC FQ Surveillance Technical Specifications," February 2019.

c. The core operating limits shall be determined such that all applicable limits (e.g., fuel thermal mechanical limits, core thermal hydraulic limits, Emergency Core Cooling Systems (ECCS) limits, nuclear limits such as SDM, transient analysis limits, and accident analysis limits) of the safety analysis are met.

d. The COLR, including any midcycle revisions or supplements, shall be provided within 30 days of issuance for each reload cycle to the NRC.

5.6.4 Reactor Coolant System (RCS) PRESSURE AND TEMPERATURE LIMITS REPORT

a. RCS pressure and temperature limits for heat up, cooldown, low temperature operation, criticality, and hydrostatic testing, LTOP arming, and PORV lift settings as well as heatup and cooldown rates shall be established and documented in the PTLR for the following:

1. LCO 3.4.3, "RCS Pressure and Temperature (P/T) Limits”;

2. LCO 3.4.12, "Low Temperature Overpressure Protection (LTOP) System"; and

3. LCO 3.5.2, “ECCS – Operating”.

b. The analytical methods used to determine the RCS pressure and temperature limits shall be those previously reviewed and approved by the NRC, specifically those described in the following documents:

1. Westinghouse Topical Report WCAP-14040-NP-A, "Methodology used to Develop Cold Overpressure Mitigating System Setpoints and RCS Heatup and Cooldown Limit Curves";

2. Westinghouse Topical Report WCAP-15293, "Sequoyah Unit 1 Heatup and Cooldown Limit Curves for Normal Operation and PTLR Support Documentation”; and

3. Westinghouse Topical Report WCAP-15984, "Reactor Vessel Closure Head/Vessel Flange Requirements Evaluation for Sequoyah Units 1 and 2."

c. The PTLR shall be provided to the NRC within 30 days of issuance for each reactor vessel fluence period and for any revision or supplement thereto.

SEQUOYAH – UNIT 1 5.6-4 Amendment 334, Reporting Requirements 5.6

5.6 Reporting Requirements

5.6.5 Post Accident Monitoring Report

When a report is required by Condition B or I of LCO 3.3.3, "Post Accident Monitoring (PAM) Instrumentation," a report shall be submitted within the following 14 days. The report shall outline the preplanned alternate method of monitoring, the cause of the inoperability, and the plans and schedule for restoring the instrumentation channels of the Function to OPERABLE status.

5.6.6 Steam Generator Tube Inspection Report

A report shall be submitted within 180 days after the initial entry into MODE 4 following completion of an inspection performed in accordance with the Specification 5.5.7, "Steam Generator (SG) Program." The report shall include:

a. The scope of inspections performed on each SG;

b. Active degradation mechanisms found;

c. Nondestructive examination techniques utilized for each degradation mechanism;

d. Location, orientation (if linear), and measured sizes (if available) of service induced indications;

e. Number of tubes plugged during the inspection outage for each active degradation mechanism;

f. Total number and percentage of tubes plugged to date;

g. The results of condition monitoring, including the results of tube pulls and in-situ testing; and

h. The effective plugging percentage for all plugging in each SG.

SEQUOYAH – UNIT 1 5.6-5 Amendment 334, Enclosure 1

Evaluation of the Transition to Westinghouse RFA-2 Fuel

ATTACHMENT 4

Proposed TS Changes (Final Typed) for SQN Unit 2

CNL-20-014 - 11 -

s. Primary Coolant Outside Containment (Section 22.2, III.D.1.1)

Prior to exceeding 5 percent power level, TVA is required to complete the leak tests on Unit 2, and results are to be submitted within 30 days from the completion of the testing.

(17) Surveillance Interval Extension

The performance interval for the 36-month surveillance requirements in TS 4.3.2.1.3 shall be extended to May 18, 1996, to coincide with the Cycle 7 refueling outage. The extended interval shall not exceed a total of 50 months for the 36-month surveillances.

(18) Transition Core Peaking Penalties

When Framatome HTP fuel assemblies are co-resident with the Westinghouse RFA-2 fuel assemblies: N (a) The HTP fuel assemblies FοH shall be maintained less than 1.61; (b) The RFA-2 fuel assemblies DNBR limit shall be reduced by: 1. 0.25% for the WRB-2M critical heat flux correlation 2. 0.50% for the ABB-NV critical heat flux correlation

(19) Steam Generator Replacement Project

During the Unit 1 Cycle 12 refueling and steam generator replacement outage, lifts of heavy loads will be performed in accordance with Table 3.1 of NRC Safety Evaluation dated March 26, 2003.

(20) Control Room Air Conditioning System Maintenance

TVA commits to the use of a portable chiller package and air-handling unit to provide alternate cooling if both trains of the control room air condition system become inoperable during the maintenance activities to upgrade the compressors and controls or immediately enter Technical Specification 3.0.3.

(21) Mitigation Strategy License Condition

Develop and maintain strategies for addressing large fires and explosions and that include the following key areas:

(a) Fire fighting response strategy and with the following elements: 1. Pre-defined coordinated fire response strategy and guidance 2. Assessment of mutual aid fire fighting assets 3. Designated staging areas for equipment and materials 4. Command and control 5. Training of response personnel

Renewed License No. DPR 79 XXXXX, XX, 2021 TABLE OF CONTENTS Page

1.0 USE AND APPLICATION 1.1 Definitions ...... 1.1-1 1.2 Logical Connectors ...... 1.2-1 1.3 Completion Times ...... 1.3-1 1.4 Frequency ...... 1.4-1

2.0 SAFETY LIMITS (SLs) ...... 2.0-1 2.1 SLs 2.2 SL Violations

3.0 LIMITING CONDITION FOR OPERATION (LCO) APPLICABILITY ...... 3.0-1 3.0 SURVEILLANCE REQUIREMENT (SR) APPLICABILITY ...... 3.0-4

3.1 REACTIVITY CONTROL SYSTEMS 3.1.1 SHUTDOWN MARGIN (SDM) ...... 3.1.1-1 3.1.2 Core Reactivity ...... 3.1.2-1 3.1.3 Moderator Temperature Coefficient (MTC) ...... 3.1.3-1 3.1.4 Rod Group Alignment Limits ...... 3.1.4-1 3.1.5 Shutdown Bank Insertion Limits ...... 3.1.5-1 3.1.6 Control Bank Insertion Limits ...... 3.1.6-1 3.1.7 Rod Position Indication ...... 3.1.7-1 3.1.8 PHYSICS TESTS Exceptions - MODE 2 ...... 3.1.8-1

3.2 POWER DISTRIBUTION LIMITS 3.2.1 Heat Flux Hot Channel Factor (FQ(Z)) (RAOC-T(Z) Methodology) ...... 3.2.1-1 N 3.2.2 Nuclear Enthalpy Rise Hot Channel Factor (F 'H) ...... 3.2.2-1 3.2.3 AXIAL FLUX DIFFERENCE (AFD) ...... 3.2.3-1 3.2.4 QUADRANT POWER TILT RATIO (QPTR) ...... 3.2.4-1

3.3 INSTRUMENTATION 3.3.1 Reactor Trip System (RTS) Instrumentation ...... 3.3.1-1 3.3.2 Engineered Safety Feature Actuation System (ESFAS) Instrumentation ...... 3.3.2-1 3.3.3 Post Accident Monitoring (PAM) Instrumentation ...... 3.3.3-1 3.3.4 Remote Shutdown Monitoring Instrumentation ...... 3.3.4-1 3.3.5 Loss of Power (LOP) Diesel Generator (DG) Start Instrumentation ...... 3.3.5-1 3.3.6 Containment Ventilation Isolation Instrumentation ...... 3.3.6-1 3.3.7 Control Room Emergency Ventilation System (CREVS) Actuation Instrumentation ...... 3.3.7-1 3.3.8 Auxiliary Building Gas Treatment System (ABGTS) Actuation Instrumentation ...... 3.3.8-1 3.3.9 Boron Dilution Monitoring Instrumentation (BDMI) ...... 3.3.9-1

3.4 REACTOR COOLANT SYSTEM (RCS) 3.4.1 RCS Pressure, Temperature, and Flow Departure from Nucleate Boiling (DNB) Limits ...... 3.4.1-1 3.4.2 RCS Minimum Temperature for Criticality ...... 3.4.2-1 3.4.3 RCS Pressure and Temperature (P/T) Limits ...... 3.4.3-1 3.4.4 RCS Loops - MODES 1 and 2 ...... 3.4.4-1

SEQUOYAH - UNIT 2 i Amendment 327, 2.0 SAFETY LIMITS (SLs)

2.1 SLs

2.1.1 Reactor Core SLs

In MODES 1 and 2, the combination of THERMAL POWER, Reactor Coolant System (RCS) highest loop average temperature, and pressurizer pressure shall not exceed the limits specified in the COLR, and the following SLs shall not be exceeded:

2.1.1.1 The departure from nucleate boiling ratio (DNBR) shall be maintained • 1.14 for the WRB-2M correlation.

2.1.1.2 The maximum local fuel pin centerline temperature shall be maintained < 5080°F, decreasing by 9°F per 10,000 MWD/MTU of burnup

2.1.2 Reactor Coolant System Pressure SL

In MODES 1, 2, 3, 4, and 5, the RCS pressure shall be maintained ” 2735 psig.

2.2 SAFETY LIMIT VIOLATIONS

2.2.1 If SL 2.1.1 is violated, restore compliance and be in MODE 3 within 1 hour.

2.2.2 If SL 2.1.2 is violated:

2.2.2.1 In MODE 1 or 2, restore compliance and be in MODE 3 within 1 hour.

2.2.2.2 In MODE 3, 4, or 5, restore compliance within 5 minutes.

SEQUOYAH – UNIT 2 2.0-1 Amendment 327, Rod Group Alignment Limits 3.1.4

ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME

B.2.1.2 Initiate boration to restore 1 hour SDM to within limit.

AND

B.2.2 Reduce THERMAL 2 hours POWER to ” 75% RTP.

AND

B.2.3 Verify SDM is within the Once per limits specified in the 12 hours COLR.

AND

B.2.4 Perform SR 3.2.1.1 and 72 hours SR 3.2.1.2.

AND

B.2.5 Perform SR 3.2.2.1. 72 hours

AND

B.2.6 Re-evaluate safety 5 days analyses and confirm results remain valid for duration of operation under these conditions.

C. Required Action and C.1 Be in MODE 3. 6 hours associated Completion Time of Condition B not met.

D. More than one rod not D.1.1 Verify SDM is within the 1 hour within alignment limit. limits specified in the COLR.

OR

SEQUOYAH – UNIT 2 3.1.4-2 Amendment 327, Rod Position Indication 3.1.7

3.1 REACTIVITY CONTROL SYSTEMS

3.1.7 Rod Position Indication

LCO 3.1.7 The Rod Position Indication System and the Demand Position Indication System shall be OPERABLE.

APPLICABILITY: MODES 1 and 2.

ACTIONS ------NOTES------1. Separate Condition entry is allowed for each inoperable rod position indicator and each demand position indicator.

2. LCO 3.0.4.a and b are not applicable for Required Actions A.2.1 and A.2.2 following a startup from a refueling outage, or following entry into MODE 5 of sufficient duration to safely repair an inoperable rod position indication. ------

CONDITION REQUIRED ACTION COMPLETION TIME

A. One rod position A.1 Verify the position of the Once per 12 hours indicator per bank rods with inoperable inoperable. position indicators indirectly by using core power distribution measurement information.

OR

------NOTE------Required Actions A.2.1 and A.2.2 may only be applied to one inoperable rod position indicator. ------

A.2.1 Verify position of the 8 hours rod with inoperable position indicator indirectly AND by using core power distribution measurement information.

SEQUOYAH – UNIT 2 3.1.7-1 Amendment 327, Rod Position Indication 3.1.7

ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME

B. More than one rod B.1 Place the control rods Immediately position indicator per under manual control. bank inoperable. AND

B.2 Monitor and record Reactor Once per 1 hour Coolant System Tavg.

AND

B.3 Verify the position of the Once per 12 hours rods with inoperable position indicators indirectly by using core power distribution measurement information.

AND

B.4 Restore inoperable position 24 hours indicators to OPERABLE status such that a maximum of one rod position indicator per bank is inoperable.

C. One or more rods with C.1 Verify the position of the Immediately inoperable position rods with inoperable indicators have been position indicators indirectly moved in excess of 24 by using core power steps in one direction distribution measurement since the last information. determination of the rod’s position. OR 8 hours C.2 Reduce THERMAL POWER to < 50% RTP.

SEQUOYAH – UNIT 2 3.1.7-3 Amendment 327, FQ(Z) (RAOC-T(Z) Methodology) 3.2.1

3.2 POWER DISTRIBUTION LIMITS

3.2.1 Heat Flux Hot Channel Factor (FQ(Z)) (RAOC-T(Z) Methodology)

C W LCO 3.2.1 FQ(Z), as approximated by FQ(Z) and FQ (Z), shall be within the limits specified in the COLR.

APPLICABILITY: MODE 1.

ACTIONS

CONDITION REQUIRED ACTION COMPLETION TIME

A. ------NOTE------A.1 Reduce THERMAL 15 minutes after each Required Action A.4 C POWER • 1% RTP for FQ(Z) determination shall be completed C each 1% FQ(Z) exceeds whenever this Condition limit. is entered prior to increasing THERMAL AND POWER above the limit of Required Action A.1. A.2 Reduce Power Range 72 hours after each SR 3.2.1.2 is not C Neutron Flux – High trip F (Z) determination required to be Q setpoints • 1% for performed if this each 1% that THERMAL Condition is entered POWER is limited below prior to THERMAL RTP by Required POWER exceeding Action A.1. 75% RTP after a

refueling. AND ------

A.3 Reduce Overpower ¨T trip FC(Z) not within limit. 72 hours after each Q setpoints • 1% for each 1% C FQ(Z) determination that THERMAL POWER is limited below RTP by Required Action A.1.

AND

A.4 Perform SR 3.2.1.1 and Prior to increasing SR 3.2.1.2. THERMAL POWER above the limit of Required Action A.1

SEQUOYAH – UNIT 2 3.2.1-1 Amendment 327, FQ(Z) (RAOC-T(Z) Methodology) 3.2.1

ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME

W B. FQ (Z) not within limits B.1.1 Implement a RAOC 4 hours operating space specified in the COLR that restores W FQ (Z) to within its limits.

AND

B.1.2 Perform SR 3.2.1.1 and 72 hours SR 3.2.1.2 if control rod motion is required to comply with the new operating space.

OR

B.2.1 ------NOTE------Required Action B.2.4 shall be completed whenever Required Action B.2.1 is performed prior to increasing THERMAL POWER above the limit of Required Action B.2.1. ------

Limit allowable THERMAL 4 hours after each W POWER and AFD limits as FQ (Z) determination specified in the COLR.

AND

B.2.2 Limit Power Range 72 hours after each W Neutron Flux - High trip FQ (Z) determination setpoints • 1% for each 1% that THERMAL POWER is limited below RTP by Required Action B.2.1.

AND

SEQUOYAH – UNIT  3.2.1-2 Amendment 334, FQ(Z) (RAOC-T(Z) Methodology) 3.2.1

CONDITION REQUIRED ACTION COMPLETION TIME

B.2.3 Limit Overpower ¨T trip 72 hours after each W setpoints • 1% for each 1% FQ (Z) determination that THERMAL POWER is limited below RTP by Required Action B.2.1.

AND

B.2.4 Perform SR 3.2.1.1 and SR 3.2.1.2. Prior to increasing THERMAL POWER above the limit of Required Action B.2.1

C. Required Action and C.1 Be in MODE 2. 6 hours associated Completion Time not met.

SURVEILLANCE REQUIREMENTS

SURVEILLANCE FREQUENCY

C SR 3.2.1.1 Verify FQ(Z) is within limit. Once after each refueling prior to THERMAL POWER exceeding 75% RTP

AND

Once within 24 hours after achieving equilibrium conditions after exceeding, by • 10% RTP, the THERMAL

SEQUOYAH – UNIT  3.2.1-3 Amendment 334, FQ(Z) (RAOC-T(Z) Methodology) 3.2.1

SURVEILLANCE REQUIREMENTS (continued)

SURVEILLANCE FREQUENCY

POWER at which C FQ(Z) was last verified

AND

In accordance with the Surveillance Frequency Control Program

W SR 3.2.1.2 Verify FQ (Z) is within limit. Once after each refueling within 24 hours after THERMAL POWER exceeds 75% RTP

AND

Once within 24 hours after achieving equilibrium conditions after exceeding, by • 10% RTP, the THERMAL POWER at which W FQ (Z) was last verified

AND

In accordance with the Surveillance Frequency Control Program

SEQUOYAH – UNIT  3.2.1-4 Amendment 334, N F¨H 3.2.2

3.2 POWER DISTRIBUTION LIMITS

N 3.2.2 Nuclear Enthalpy Rise Hot Channel Factor (F¨H)

N LCO 3.2.2 F¨H shall be within the limits specified in the COLR.

APPLICABILITY: MODE 1.

ACTIONS

CONDITION REQUIRED ACTION COMPLETION TIME

N A. ------NOTE------A.1.1 Restore F¨H to within limit. 4 hours Required Actions A.2 and A.3 must be OR completed whenever Condition A is entered. A.1.2.1 Reduce THERMAL 4 hours ------POWER to < 50% RTP.

N F¨H not within limit. AND

A.1.2.2 Reduce Power Range 72 hours Neutron Flux – High trip setpoints to ” 55% RTP.

AND

A.2 Perform SR 3.2.2.1. 24 hours

AND

A.3 ------NOTE------THERMAL POWER does not have to be reduced to comply with this Required Action. ------

Perform SR 3.2.2.1. Prior to THERMAL POWER exceeding 50% RTP

AND

SEQUOYAH – UNIT 2 3.2.2-1 Amendment 327, N F¨H 3.2.2

ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME

Prior to THERMAL POWER exceeding 75% RTP

AND

24 hours after THERMAL POWER reaching • 95% RTP

B. Required Action and B.1 Be in MODE 2. 6 hours associated Completion Time not met.

SURVEILLANCE REQUIREMENTS

SURVEILLANCE FREQUENCY

N SR 3.2.2.1 Verify F¨H is within limits specified in the COLR. Once after each refueling prior to THERMAL POWER exceeding 75% RTP

AND

In accordance with the Surveillance Frequency Control Program

SEQUOYAH – UNIT 2 3.2.2-2 Amendment 327, QPTR 3.2.4

3.2 POWER DISTRIBUTION LIMITS

3.2.4 QUADRANT POWER TILT RATIO (QPTR)

LCO 3.2.4 The QPTR shall be ” 1.02.

APPLICABILITY: MODE 1 with THERMAL POWER > 50% RTP.

ACTIONS

CONDITION REQUIRED ACTION COMPLETION TIME

A. QPTR not within limit. A.1 Reduce THERMAL 2 hours after each POWER • 3% from RTP for QPTR determination each 1% of QPTR > 1.02.

AND

A.2 Determine QPTR. Once per 12 hours

AND

A.3 Perform SR 3.2.1.1, 24 hours after SR 3.2.1.2, and achieving equilibrium SR 3.2.2.1. conditions from a THERMAL POWER reduction per Required Action A.1

AND

Once per 7 days thereafter

AND

SEQUOYAH – UNIT 2 3.2.4-1 Amendment 327, QPTR 3.2.4

ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME

A.4 Reevaluate safety analyses Prior to increasing and confirm results remain THERMAL POWER valid for duration of above the limit of operation under this Required Action A.1 condition.

AND

A.5 ------NOTES------1. Perform Required Action A.5 only after Required Action A.4 is completed.

2. Required Action A.6 shall be completed whenever Required Action A.5 is performed. ------Prior to increasing Normalize excore detectors THERMAL POWER to restore QPTR to within above the limit of limit. Required Action A.1

AND

A.6 ------NOTE------Perform Required Action A.6 only after Required Action A.5 is completed. Within 24 hours after ------achieving equilibrium conditions at RTP not Perform SR 3.2.1.1, to exceed 48 hours SR 3.2.1.2, and SR 3.2.2.1. after increasing THERMAL POWER above the limit of Required Action A.1

SEQUOYAH – UNIT 2 3.2.4-2 Amendment 327, QPTR 3.2.4

ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME

B. Required Action and B.1 Reduce THERMAL 4 hours associated Completion POWER to ” 50% RTP. Time not met.

SURVEILLANCE REQUIREMENTS

SURVEILLANCE FREQUENCY

SR 3.2.4.1 ------NOTES------1. With input from one Power Range Neutron Flux channel inoperable and THERMAL POWER ” 75% RTP, the remaining three power range channels can be used for calculating QPTR.

2. SR 3.2.4.2 may be performed in lieu of this Surveillance. ------

Verify QPTR is within limit by calculation. In accordance with the Surveillance Frequency Control Program

SR 3.2.4.2 ------NOTE------Only required to be performed if input to QPTR from one or more Power Range Neutron Flux channels are inoperable with THERMAL POWER > 75% RTP. ------

Verify QPTR is within limit using core power Once within 12 distribution measurement information. hours

AND

In accordance with the Surveillance Frequency Control Program

SEQUOYAH – UNIT 2 3.2.4-3 Amendment 327, 336, RTS Instrumentation 3.3.1

SURVEILLANCE REQUIREMENTS ------NOTE------Refer to Table 3.3.1-1 to determine which SRs apply for each RTS Function. ------

SURVEILLANCE FREQUENCY

SR 3.3.1.1 Perform CHANNEL CHECK. In accordance with the Surveillance Frequency Control Program

SR 3.3.1.2 ------NOTE------Not required to be performed until 12 hours after THERMAL POWER is t 15% RTP. ------

Compare results of calorimetric heat balance In accordance calculation to power range channel output. Adjust with the power range channel output if absolute difference is Surveillance > 2%. Frequency Control Program

SR 3.3.1.3 ------NOTE------Not required to be performed until 96 hours after THERMAL POWER is t 15% RTP. ------

Compare results of the core power distribution In accordance measurements to Nuclear Instrumentation System with the (NIS) AFD. Adjust NIS channel if absolute Surveillance difference is t 3%. Frequency Control Program

SR 3.3.1.4 ------NOTE------This Surveillance must be performed on the reactor trip bypass breaker prior to placing the bypass breaker in service. ------

Perform TADOT. In accordance with the Surveillance Frequency Control Program

SEQUOYAH – UNIT 2 3.3.1-9 Amendment 327, RTS Instrumentation 3.3.1

SURVEILLANCE REQUIREMENTS (continued)

SURVEILLANCE FREQUENCY

SR 3.3.1.5 Perform ACTUATION LOGIC TEST. In accordance with the Surveillance Frequency Control Program

SR 3.3.1.6 ------NOTE------Not required to be performed until 24 hours after THERMAL POWER is • 50% RTP. ------

Calibrate excore channels to agree with core power In accordance distribution measurements. with the Surveillance Frequency Control Program

SR 3.3.1.7 ------NOTE------Not required to be performed for source range instrumentation prior to entering MODE 3 from MODE 2 until 4 hours after entry into MODE 3. ------

Perform COT. In accordance with the Surveillance Frequency Control Program

SEQUOYAH – UNIT 2 3.3.1-10 Amendment 327, RTS Instrumentation 3.3.1

Table 3.3.1-1 (page 7 of 9) Reactor Trip System Instrumentation

Note 1: Overtemperature ¨T

The Overtemperature ¨T Function Allowable Value shall not exceed the following Nominal Trip Setpoint by more than 1.9% of ¨T span.

§1W S · ­ § 1W S · ½ 4 1 c c 'T ¨ ¸ 0 ® 'd KKT 21 ¨ ¸>@ 3  1 ' IfPPKTT )()( ¾ ©1W 5 S ¹ ¯ ©1W 2 S ¹ ¿

Where: ¨T is measured RCS ¨T,°F. ¨T0 is the indicated ¨T at RTP,°F. S is the Laplace transform operator, sec-1. T is the measured RCS average temperature,°F. ' T is the nominal Tavg at RTP, ” **°F.

P is the measured pressurizer pressure, psig P' is the nominal RCS operating pressure, = ** psig

K1 ” ** K2 • **/°F K3 = **/psig W1 • ** sec W2 ” ** sec W4 • ** sec W5 ” ** sec

and f1 ('I) is a function such that:

(i) for qt - qb between QTNL* and QTPL* f1 ('I) = 0

* (ii) for each percent that the magnitude of (qt - qb) exceeds QTNL , the 'T nominal trip setpoint shall be automatically reduced by QTNS* of its value at RATED THERMAL POWER.

* (iii) for each percent that the magnitude of (qt - qb) exceeds QTPL , the 'T nominal trip setpoint shall be automatically reduced by QTPS* of its value at RATED THERMAL POWER.

Where qt and qb are percent RTP in the upper and lower halves of the core, respectively, and qt + qb is the total THERMAL POWER in percent RTP.

*QTNL, QTPL, QTNS, and QTPS are specified in the COLR.

The values denoted with ** are specified in the COLR.

SEQUOYAH – UNIT 2 3.3.1-20 Amendment 327, RTS Instrumentation 3.3.1

Table 3.3.1-1 (page 8 of 9) Reactor Trip System Instrumentation

Note 2: Overpower ¨T

The Overpower ¨T Function Allowable Value shall not exceed the following Nominal Trip Setpoint by more than 1.7% of ¨T span.

§ 1  W S · ­ § W S · ½ ' T 4 'd KKT ¨ 3 ¸ ' IfTTKT )(" ¨ ¸ 0 ® 54 ¨ ¸ 6 2 ¾ © 1  W 5 S ¹ ¯ © 1W 3 S ¹ ¿

Where: ¨T is measured RCS ¨T,°F. ¨T0 is the indicated ¨T at RTP,°F. S is the Laplace transform operator, sec-1. T is the measured RCS average temperature,°F. " T is the nominal Tavg at RTP, ” **°F.

" K4 ” ** K5 • **/°F for increasing Tavg K6 • **/°F when T > T " **/°F for decreasing Tavg **/°F when T ” T W3 • ** sec W 4 • ** sec W5 ” ** sec

and f2 ('I) is a function such that:

(i) for qt - qb between QPNL* and QPPL* f2 ('I) = 0

* (ii) for each percent that the magnitude of (qt - qb) exceeds QPNL , the 'T nominal trip setpoint shall be automatically reduced by QPNS* of its value at RATED THERMAL POWER.

(iii) for each percent that the magnitude of (qt - qb) exceeds QPPL*, the ǻT nominal trip setpoint shall be automatically reduced by QPPS* of its value at RATED THERMAL POWER.

Where qt and qb are percent RTP in the upper and lower halves of the core, respectively, and qt + qb is the total THERMAL POWER in percent RTP.

*QPNL, QPPL, QPNS, and QPPS are specified in the COLR.

The values denoted with ** are specified in the COLR.

SEQUOYAH – UNIT 2 3.3.1-21 Amendment 327, RCS Pressure, Temperature, and Flow DNB Limits 3.4.1

3.4 REACTOR COOLANT SYSTEM (RCS)

3.4.1 RCS Pressure, Temperature, and Flow Departure from Nucleate Boiling (DNB) Limits

LCO 3.4.1 RCS DNB parameters for pressurizer pressure, RCS average temperature, and RCS total flow rate shall be within the limits specified below:

a. Pressurizer pressure is greater than or equal to the limit specified in the COLR psia;

b. RCS average temperature is less than or equal to the limit specified in the COLR; and

c. RCS total flow rate • 360,000 gpm and greater than or equal to the limit specified in the COLR.

APPLICABILITY: MODE 1.

------NOTE------Pressurizer pressure limit does not apply during:

a. THERMAL POWER ramp > 5% RTP per minute;

b. THERMAL POWER step > 10% RTP;

c. PHYSICS TESTS; or

d. Performance of SR 3.1.3.2. ------

ACTIONS

CONDITION REQUIRED ACTION COMPLETION TIME

A. One or more RCS DNB A.1 Restore RCS DNB 2 hours parameters not within parameter(s) to within limit. limits.

B. Required Action and B.1 Be in MODE 2. 6 hours associated Completion Time not met.

SEQUOYAH – UNIT 2 3.4.1-1 Amendment 327, RCS Pressure, Temperature, and Flow DNB Limits 3.4.1

SURVEILLANCE REQUIREMENTS

SURVEILLANCE FREQUENCY

SR 3.4.1.1 Verify pressurizer pressure is greater than or equal In accordance to the limit specified in the COLR. with the Surveillance Frequency Control Program

SR 3.4.1.2 Verify RCS average temperature is less than or In accordance equal to the limit specified in the COLR. with the Surveillance Frequency Control Program

SR 3.4.1.3 Verify RCS total flow rate is • 360,000 gpm and In accordance greater than or equal to the limit specified in the with the COLR. Surveillance Frequency Control Program

SR 3.4.1.4 Verify by measurement that RCS total flow rate is In accordance • 360,000 and greater than or equal to the limit with the specified in the COLR gpm. Surveillance Frequency Control Program

SEQUOYAH – UNIT 2 3.4.1-2 Amendment 327, Design Features 4.0

4.0 DESIGN FEATURES

4.1 Site Location

The Sequoyah Nuclear Plant is located on a site near the geographical center of Hamilton County, Tennessee, on a peninsula on the western shore of Chickamauga Lake at Tennessee River mile (TRM) 484.5. The Sequoyah site is approximately 7.5 miles northeast of the nearest city limit of Chattanooga, Tennessee, 14 miles west-northwest of Cleveland, Tennessee, and approximately 31 miles south-southwest of TVA's Watts Bar Nuclear Plant.

4.2 Reactor Core

4.2.1 Fuel Assemblies

The reactor shall contain 193 fuel assemblies. Each assembly shall consist of a matrix of Optimized ZirloTM, Zircaloy or M5 clad fuel rods with an initial composition of natural or slightly enriched uranium dioxide (UO2) as fuel material. Limited substitutions of zirconium alloy or stainless steel filler rods for fuel rods, in accordance with approved applications of fuel rod configurations, may be used. Fuel assemblies shall be limited to those fuel designs that have been analyzed with applicable NRC staff approved codes and methods and shown by tests or analyses to comply with all fuel safety design bases. A limited number of lead test assemblies that have not completed representative testing may be placed in nonlimiting core regions.

4.2.2 Control Rod Assemblies

The reactor core shall contain 52 full length and no part length control rod assemblies (with no full length control rod assembly in core location H-08). The full length control rod assemblies shall contain a nominal 142 inches of absorber material. The nominal values of absorber material shall be 80 percent silver, 15 percent indium, and 5 percent cadmium. All control rods shall be clad with stainless steel tubing.

4.3 Fuel Storage

4.3.1 Criticality

4.3.1.1 The spent fuel storage racks are designed and shall be maintained with:

a. Fuel assemblies having a maximum U-235 enrichment of 5.0 weight percent;

SEQUOYAH – UNIT 2 4.0-1 Amendment 327, 342, Reporting Requirements 5.6

5.6 Reporting Requirements

5.6.3 CORE OPERATING LIMITS REPORT

a. Core operating limits shall be established prior to each reload cycle, or prior to any remaining portion of a reload cycle, and shall be documented in the COLR for the following:

1. LCO 2.1.1, “Reactor Core Safety Limits”;

2. LCO 3.1.1, "SHUTDOWN MARGIN (SDM)";

3. LCO 3.1.3, "Moderator Temperature Coefficient (MTC)";

4. LCO 3.1.4, “Rod Group Alignment Limits”;

5. LCO 3.1.5, "Shutdown Bank Insertion Limits";

6. LCO 3.1.6, "Control Bank Insertion Limits";

7. LCO 3.1.8, “PHYSICS TESTS Exceptions - MODE 2”;

8. LCO 3.2.1, "Heat Flux Hot Channel Factor Factor (FQ(Z)) (RAOC-T(Z) Methodology)";

N 9. LCO 3.2.2, "Nuclear Enthalpy Rise Hot Channel Factor (F¨H)";

10. LCO 3.2.3, "AXIAL FLUX DIFFERENCE (AFD)";

11. LCO 3.3.1, "Reactor Trip System (RTS) Instrumentation;"

12. LCO 3.4.1, “RCS Pressure, Temperature, and Flow Departure from Nucleate Boiling (DNB) Limits”; and

13. LCO 3.9.1, "Boron Concentration."

b. The analytical methods used to determine the core operating limits shall be those previously reviewed and approved by the NRC, specifically those described in the following documents:

1. WCAP-8745-P-A, “Design Bases for the Thermal Overpower ¨T and Thermal Overtemperature ¨T Trip Functions,” September 1986;

2. WCAP-9272-P-A, “Westinghouse Reload Safety Evaluation Methodology,” July 1985;

3. WCAP-10216-P-A, Revision 1A, “Relaxation of Constant Axial Offset Control – FQ Surveillance Technical Specification,” February 1994;

SEQUOYAH – UNIT 2 5.6-2 Amendment 327, Reporting Requirements 5.6

5.6 Reporting Requirements

5.6.3 CORE OPERATING LIMITS REPORT (continued)

4. WCAP-10444-P-A, “Reference Core Report VANTAGE 5 Fuel Assembly,” September 1985;

5. WCAP-10444-P-A Addendum 2-A, “VANTAGE 5H Fuel Assembly,” February 1989;

6. WCAP-10965-P-A, “ANC: A Westinghouse Advanced Nodal Computer Code,” September 1986;

7. WCAP-10965-P-A, Addendum 2-A, Revision 0, “Qualification of the New Pin Power Recovery Methodology,” September 2010;

8. WCAP-11397-P-A, “Revised Thermal Design Procedure,” April 1989;

9. WCAP-12610-P-A, “VANTAGE+ Fuel Assembly Reference Core Report,” April 1995;

10. WCAP-12610-P-A & CENPD-404-P-A, Addendum 1-A, “Optimized ZIRLOTM,” July 2006;

11. WCAP-14565-P-A, “VIPRE-01 Modeling and Qualification for Pressurized Water Reactor Non-LOCA Thermal-Hydraulic Safety Analysis,” October 1999;

12. WCAP-14565-P-A, Addendum 1-A, Revision 0, “Addendum 1 to WCAP 14565-P-A Qualification of ABB-NV Critical Heat Flux Correlations with VIPRE-01 Code,” August 2004;

13. WCAP-14565-P-A, Addendum 2-P-A, Revision 0, “Addendum 2 to WCAP-14565-P-A Extended Application of ABB-NV Correlation and Modified ABB-NV Correlation WLOP for PWR Low Pressure Applications,” April 2008;

14. WCAP-15025-P-A, “Modified WRB-2 Correlation, WRB-2M, for Predicting Critical Heat Flux in 17x17 Rod Bundles with Modified LPD Mixing Vane Grids,” April 1999;

15. WCAP-16045-P-A, “Qualification of the Two-Dimensional Transport Code PARAGON,” August 2004;

16. WCAP-16045-P-A, Addendum 1-A, “Qualification of the NEXUS Nuclear Data Methodology,” August 2007;

17. WCAP-16996-P-A, Revision 1, “Realistic LOCA Evaluation Methodology Applied to the Full Spectrum of Break Sizes (FULL SPECTRUM LOCA Methodology),” November 2016; and

SEQUOYAH – UNIT 2 5.6-3 Amendment 327, Reporting Requirements 5.6

5.6 Reporting Requirements

5.6.3 CORE OPERATING LIMITS REPORT (continued)

18. WCAP-17661-P-A, Revision 1, "Improved RAOC and CAOC FQ Surveillance Technical Specifications," February 2019.

c. The core operating limits shall be determined such that all applicable limits (e.g., fuel thermal mechanical limits, core thermal hydraulic limits, Emergency Core Cooling Systems (ECCS) limits, nuclear limits such as SDM, transient analysis limits, and accident analysis limits) of the safety analysis are met.

d. The COLR, including any midcycle revisions or supplements, shall be provided within 30 days of issuance for each reload cycle to the NRC.

5.6.4 Reactor Coolant System (RCS) PRESSURE AND TEMPERATURE LIMITS REPORT

a. RCS pressure and temperature limits for heat up, cooldown, low temperature operation, criticality, and hydrostatic testing, LTOP arming, and PORV lift settings as well as heatup and cooldown rates shall be established and documented in the PTLR for the following:

1. LCO 3.4.3, "RCS Pressure and Temperature (P/T) Limits”;

2. LCO 3.4.12, "Low Temperature Overpressure Protection (LTOP) System"; and

3. LCO 3.5.2, “ECCS – Operating”.

b. The analytical methods used to determine the RCS pressure and temperature limits shall be those previously reviewed and approved by the NRC, specifically those described in the following documents:

1. Westinghouse Topical Report WCAP-14040-NP-A, "Methodology used to Develop Cold Overpressure Mitigating System Setpoints and RCS Heatup and Cooldown Limit Curves";

2. Westinghouse Topical Report WCAP-15293, "Sequoyah Unit 1 Heatup and Cooldown Limit Curves for Normal Operation and PTLR Support Documentation”; and

3. Westinghouse Topical Report WCAP-15984, "Reactor Vessel Closure Head/Vessel Flange Requirements Evaluation for Sequoyah Units 1 and 2."

c. The PTLR shall be provided to the NRC within 30 days of issuance for each reactor vessel fluence period and for any revision or supplement thereto.

SEQUOYAH – UNIT 2 5.6-4 Amendment 327, Reporting Requirements 5.6

5.6 Reporting Requirements

5.6.5 Post Accident Monitoring Report

When a report is required by Condition B or I of LCO 3.3.3, "Post Accident Monitoring (PAM) Instrumentation," a report shall be submitted within the following 14 days. The report shall outline the preplanned alternate method of monitoring, the cause of the inoperability, and the plans and schedule for restoring the instrumentation channels of the Function to OPERABLE status.

5.6.6 Steam Generator Tube Inspection Report

A report shall be submitted within 180 days after the initial entry into MODE 4 following completion of an inspection performed in accordance with the Specification 5.5.7, "Steam Generator (SG) Program." The report shall include:

a. The scope of inspections performed on each SG;

b. Active degradation mechanisms found;

c. Nondestructive examination techniques utilized for each degradation mechanism;

d. Location, orientation (if linear), and measured sizes (if available) of service induced indications;

e. Number of tubes plugged during the inspection outage for each active degradation mechanism;

f. Total number and percentage of tubes plugged to date;

g. The results of condition monitoring, including the results of tube pulls and in- situ testing; and

h. The effective plugging percentage for all plugging in each SG.

SEQUOYAH – UNIT 2 5.6-5 Amendment 327, Enclosure 1

Evaluation of the Transition to Westinghouse RFA-2 Fuel

ATTACHMENT 5

Revised TS Bases Page Changes (Mark-Ups) for SQN Unit 1 (For Information Only)

CNL-20-014 Reactor Core SLs B 2.1.1

B 2.0 SAFETY LIMITS (SLs)

B 2.1.1 Reactor Core

BASES

BACKGROUND GDC 10 (Ref. 1) requires that specified acceptable fuel design limits are not exceeded during steady state operation, normal operational transients, and anticipated operational occurrences (AOOs). This is accomplished by having a departure from nucleate boiling (DNB) design basis, which corresponds to a 95% probability at a 95% confidence level (the 95/95 DNB criterion) that DNB will not occur at the limiting rod location during Condition I and II events, and by requiring that fuel centerline temperature stays below the melting temperature with the same 95/95 probability and confidence level.

To meet the DNB design basis for Revised Thermal Design Procedure (RTDP) analyses conducted per Reference 3, uncertainties in plant operating parameters, nuclear and thermal parameters, fuel fabrication parameters, computer codes, and DNB correlation (WRB-2M) predictions are combined statistically to obtain the overall DNBR uncertainty factor. This DNBR uncertainty factor is used to define the design limit DNBR, which corresponds to a 95% probability with 95% confidence that DNB will not occur on the limiting fuel rod during Condition I and II events. Since the parameter uncertainties are considered in determining the RTDP design limit DNBR values, the plant safety analyses which use the RTDP are performed using input parameters at their nominal values. The WRB-2M correlation with a 95/95 correlation limit of 1.14 approved in Reference 4 is used in the VIPRE-W DNBR analyses for at-power events and for analyses applicable to the region above the first mixing vane grid. The ABB-NV and WLOP DNB correlations (approved in References 5 and 6, respectively) are used when the WRB-2M DNB correlation is not applicable. The ABB-NV and WLOP DNB correlation limits used in the DNBR calculations are 1.13 and 1.18, respectively. The design limit DNBR value is 1.23 for both thimble and typical cells with the WRB-2M correlation for RFA-2 fuel. The DNBR design limit values for the ABB- NV correlation are 1.18 for typical cells and 1.19 for thimble cells below the first mixing vane region of the RFA-2 fuel. Margin has been maintained by meeting a safety analysis DNBR limit of 1.58 for both thimble and typical cells for RFA-2 fuel. This DNBR margin can be used to offset known DNBR penalties and to provide operating and design flexibility.

SEQUOYAH – UNIT 1 B 2.1.1-1

Reactor Core SLs B 2.1.1

BASES

BACKGROUND (continued)

The restrictions of this SL prevent overheating of the fuel and cladding (due to departure from nucleate boiling) and overheating of the fuel pellet (centerline fuel melt (CFM)), either of which could result in cladding perforation, which would result in the release of fission products to the reactor coolant. Overheating of the fuel is prevented by maintaining the steady state peak linear heat rate (LHR) below the level at which fuel centerline melting occurs. Overheating of the fuel cladding is prevented by restricting fuel operation to within the nucleate boiling regime, where the heat transfer coefficient is large and the cladding surface temperature is slightly above the coolant saturation temperature.

Operation above the boundary of the nucleate boiling regime could result in excessive cladding temperature because of the onset of DNB and the corresponding significant reduction in heat transfer coefficient from the outer surface of the cladding to the reactor coolant water. Inside the steam film, high cladding temperatures are reached, and a cladding water (zirconium water) reaction may take place. This chemical reaction results in oxidation of the fuel cladding to a structurally weaker form. This weaker form may lose its integrity, resulting in an uncontrolled release of activity to the reactor coolant.

DNB is not a directly measurable parameter during operation and therefore THERMAL POWER and Reactor Coolant Temperature and Pressure have been related to DNB. The DNB correlations have been developed to predict the DNB flux and the location of DNB for axially uniform and non- uniform heat flux distributions. The local DNB heat flux ratio, DNBR, defined as the ratio of the heat flux that would cause DNB at a particular core location to the local heat flux, is indicative of the margin to DNB.

To meet the DNB Design Basis, a statistical core design (SCD) process has been used to develop an appropriate statistical DNBR design limit. Uncertainties in plant operating parameters, nuclear and thermal parameters, and fuel fabrication parameters are considered statistically such that there is at least a 95 percent probability at a 95 percent confidence level that the minimum DNBR for the limiting rod is greater than or equal to the DNBR limit. This DNBR uncertainty derived from the SCD analysis, combined with the applicable DNB critical heat flux correlation limit, establishes the statistical DNBR design limit which must be met in plant safety analysis using values of input parameters without adjustment for uncertainty.

Operation above the maximum local linear heat generation rate for fuel melting could result in excessive fuel pellet temperature and cause melting of the fuel at its centerline. Fuel centerline melting occurs when

SEQUOYAH – UNIT 1 B 2.1.1-2

Reactor Core SLs B 2.1.1

BASES

BACKGROUND (continued)

the local LHR, or power peaking, in a region of the fuel is high enough to cause the fuel centerline temperature to reach the melting point of the fuel. Expansion of the pellet upon centerline melting may cause the pellet to stress the cladding to the point of failure, allowing an uncontrolled release of activity to the reactor coolant. The melting point of uranium dioxide varies slightly with burnup. As uranium is depleted and fission products produced, the net effect is a decrease in the melting point. Fuel centerline temperature is not a directly measurable parameter during operation. The peak fuel maximum local fuel pin centerline temperature is maintained by limiting the local linear heat generation rate in the fuel. The local linear heat generation rate in the fuel is limited so that the peak maximum fuel centerline temperature will not exceed the acceptance criteria discussed in Reference 7.in the safety analysis.

The curves provided in Figure 1 of the COLR 2.1.1-1 show the loci of points of THERMAL POWER, pressurizer Reactor Coolant System pressure, and the highest Reactor Coolant System loop average temperature for which the minimum DNBR is no less than the safety analysis DNBR limit, or the average enthalpy at the vessel exit is equal to the enthalpy of saturated liquid.

These lines are bounding for all fuel types. The curves provided in Figure 1 of the COLR 2.1.1-1 are based upon enthalpy rise hot channel factors that result in acceptable DNBR performance of each fuel type. Acceptable DNBR performance is assured by operation within the DNB- based Limiting Safety Limit System Settings (Reactor Trip System trip limits). The plant trip setpoints are verified to be less than the limits defined by the safety limit lines provided in Figure 1 of the COLR 2.1.1-1 converted from power to delta-temperature and adjusted for uncertainty.

The limiting heat flux conditions for DNB are higher than those calculated for the range of all control rods fully withdrawn to the maximum allowable control rod insertion assuming the axial power imbalance or Delta-, ¨, LV within the limits of the f1 ¨O IXQFWLRQRIWKH2YHUWHPSHUDWXUH'HOWD Temperature trip. When the axial power imbalance exceeds the tolerance (or deadband) of the f1 ¨O WULSUHVHWIXQFWLRQWKHOvertemperature Delta Temperature trip setpoint is reduced by the values in the COLR to provide protection required by the core safety limits.

Similarly, the limiting linear heat generation rate conditions for CFM are higher than those calculated for the range of all control rods from fully withdrawn to the maximum allowable control rod insertion assuming the axial power imbalance or Delta-, ǻ, LVZLWKLQWKHOLPLWVRIWKHI2 ǻ, 

SEQUOYAH – UNIT 1 B 2.1.1-3

Reactor Core SLs B 2.1.1

BASES

BACKGROUND (continued)

function of the Overpower-Delta Temperature trip. When the axial power imbalance exceeds the tolerance (or deadband) of the f2 ǻ, WULSUHVHW function, the Overpower-Delta Temperature trip setpoint is reduced by the values specified in the COLR to provide protection required by the core safety limits.

The proper functioning of the Reactor Trip Protection System (RTPS) and steam generator safety valves prevents violation of the reactor core SLs.

APPLICABLE The fuel cladding must not sustain damage as a result of normal SAFETY operation and AOOs. The reactor core SLs are established to preclude ANALYSES violation of the following fuel design criteria:

a. There must be at least 95% probability at a 95% confidence level (the

95/95 DNB criterion) that the hot fuel rod in the core does not experience DNB and

b. There must be at least a 95% probability at a 95% confidence level that the hot fuel pellet in the core does must not experience centerline fuel melting.

The Reactor Trip System setpoints (Ref. 2), in combination with the LCOs, are designed to prevent any anticipated combination of transient conditions for Reactor Coolant System (RCS) temperature, pressure, 5&6)ORZ¨,DQG7+(50$/32:(5OHYHOWKDWZRXOGUHVXOWLQD departure from nucleate boiling ratio (DNBR) of less than the DNBR limit and preclude the existence of flow instabilities.

Automatic enforcement of these reactor core SLs is provided by the appropriate operation of the RTPS and the steam generator safety valves.

The SLs represent a design requirement for establishing the RTPS trip setpoints identified previously. LCO 3.4.1, "RCS Pressure, Temperature, and Flow Departure from Nucleate Boiling (DNB) Limits," or the assumed initial conditions of the safety analyses (as indicated in the UFSAR, Ref. 2) provide more restrictive limits to ensure that the SLs are not exceeded.

SEQUOYAH – UNIT 1 B 2.1.1-4

Reactor Core SLs B 2.1.1

BASES

SAFETY LIMITS Figure 1 of the COLR 2.1.1-1 shows the loci of points of THERMAL POWER, pressurizer RCS pressure, and highest RCS loop average temperature for which the minimum DNBR is not less than the safety analyses limit, that fuel centerline temperature remains below melting, that the average enthalpy in the hot leg is less than or equal to the enthalpy of saturated liquid, or that the exit quality is within the limits defined by the DNBR correlation.

The reactor core SLs are established to preclude violation of the following fuel design criteria:

a. There must be at least a 95% probability at a 95% confidence level (the 95/95 DNB criterion) that the hot fuel rod in the core does not experience DNB and

b. There must be at least a 95% probability at a 95% confidence level that the hot fuel pellet in the core does not experience centerline fuel melting.

The reactor core SLs are used to define the various RTPS functions such that the above criteria are satisfied during steady state operation, normal operational transients, and anticipated operational occurrences (AOOs). To ensure that the RTPS precludes the violation of the above criteria, DGGLWLRQDOFULWHULDDUHDSSOLHGWRWKH2YHUWHPSHUDWXUHDQG2YHUSRZHU¨7 reactor trip functions. That is, it must be demonstrated that the average enthalpy in the hot leg is less than or equal to the saturation enthalpy and that the core exit quality is within the limits defined by the DNBR correlation. Appropriate functioning of the RTPS ensures that for variations in the THERMAL POWER, RCS Pressure, RCS average WHPSHUDWXUH5&6IORZUDWHDQG¨,WKDWWKHUHDFWRUFRUH6/VZLOOEH satisfied during steady state operation, normal operational transients, and AOOs.

APPLICABILITY SL 2.1.1 only applies in MODES 1 and 2 because these are the only MODES in which the reactor is critical. Automatic protection functions are required to be OPERABLE during MODES 1 and 2 to ensure operation within the reactor core SLs. The steam generator safety valves or automatic protection actions serve to prevent RCS heatup to the reactor core SL conditions or to initiate a reactor trip function, which forces the unit into MODE 3. Setpoints for the reactor trip functions are specified in LCO 3.3.1, "Reactor Trip System (RTS) Instrumentation." In MODES 3, 4, 5, and 6, Applicability is not required since the reactor is not generating significant THERMAL POWER.

SEQUOYAH – UNIT 1 B 2.1.1-5

Reactor Core SLs B 2.1.1

BASES

SAFETY LIMIT The following SL violation responses are applicable to the reactor core VIOLATIONS SLs. If SL 2.1.1 is violated, the requirement to go to MODE 3 places the unit in a MODE in which this SL is not applicable.

The allowed Completion Time of 1 hour recognizes the importance of bringing the unit to a MODE of operation where this SL is not applicable, and reduces the probability of fuel damage.

REFERENCES 1. 10 CFR 50, Appendix A, GDC 10.

2. UFSAR, Section 7.2.

3. WCAP-11397-P-A, “Revised Thermal Design Procedure,” April 1989.

4. WCAP-15025-P-A, “Modified WRB-2 Correlation, WRB-2M, for Predicting Critical Heat Flux in 17x17 Rod Bundles with Modified LPD Mixing Vane Grids,” April 1999.

5. WCAP-14565-P-A, Addendum 1-A, Revision 0, “Addendum 1 to WCAP 14565-P-A Qualification of ABB-NV Critical Heat Flux Correlations with VIPRE-01 Code,” August 2004.

6. WCAP-14565-P-A, Addendum 2-P-A, Revision 0, “Addendum 2 to WCAP-14565-P-A Extended Application of ABB-NV Correlation and Modified ABB-NV Correlation WLOP for PWR Low Pressure Applications,” April 2008.

7. WCAP-17642-P-A, Revision 1, “Westinghouse Performance Analysis and Design Model (PAD5),” November 2017.

SEQUOYAH – UNIT 1 B 2.1.1-6 SDM B 3.1.1

BASES

APPLICABLE SAFETY ANALYSES (continued)

The acceptance criteria for the SDM requirements are that specified acceptable fuel design limits are maintained. This is done by ensuring that:

a. The reactor can be made subcritical from all operating conditions, transients, and Design Basis Events,

b. The reactivity transients associated with postulated accident conditions are controllable within acceptable limits (departure from nucleate boiling ratio (DNBR), fuel centerline temperature limits for AOOs, and ”280 cal/gm fuel energy deposition for the rod ejection accident), and 200 c. The reactor will be maintained sufficiently subcritical to preclude inadvertent criticality in the shutdown condition.

The most limiting accident for the SDM requirements is based on a main steam line break (MSLB), as described in the accident analysis (Ref. 2). The increased steam flow resulting from a pipe break in the main steam system causes an increased energy removal from the affected steam generator (SG), and consequently the RCS. This results in a reduction of the reactor coolant temperature. The resultant coolant shrinkage causes a reduction in pressure. In the presence of a negative moderator temperature coefficient, this cooldown causes an increase in core reactivity. As RCS temperature decreases, the severity of an MSLB decreases until the MODE 5 value is reached. The most limiting MSLB, with respect to potential fuel damage before a reactor trip occurs, is a double ended break of a main steam line inside containment initiated at the end of core life. The positive reactivity addition from the moderator temperature decrease will terminate when the affected SG boils dry, thus terminating RCS heat removal and cooldown. Following the MSLB, a post trip return to power may occur; however, no fuel damage occurs as a result of the post trip return to power, and THERMAL POWER does not violate the Safety Limit (SL) requirement of SL 2.1.1.

In addition to the limiting MSLB transient, the SDM requirements must also protect against:

a. Inadvertent boron dilution,

b. An uncontrolled rod withdrawal from subcritical or low power condition,

SEQUOYAH – UNIT 1 B 3.1.1-2 Revision 45 MTC B 3.1.3

BASES

SURVEILLANCE REQUIREMENTS (continued)

SR 3.1.3.2

In similar fashion, the LCO demands that the MTC be less negative than the specified value for EOL full power conditions. This measurement may be performed at any THERMAL POWER, but its results must be extrapolated to the conditions of RTP and all banks withdrawn in order to make a proper comparison with the LCO value. Because the RTP MTC value will gradually become more negative with further core depletion and boron concentration reduction, a 300 ppm SR value of MTC should necessarily be less negative than the EOL LCO limit. The 300 ppm SR value is sufficiently less negative than the EOL LCO limit value to ensure that the LCO limit will be met when the 300 ppm Surveillance criterion is met.

SR 3.1.3.2 is modified by three Notes that include the following requirements:

a. The SR is not required to be performed until 7 effective full power days (EFPDs) after reaching the equivalent of an equilibrium RTP all rods out (ARO) boron concentration of 300 ppm.

b. If the 300 ppm Surveillance limit is not met, it is possible that the EOL limit on MTC could be reached before the planned EOL. Because the MTC changes slowly with core depletion, the Frequency of 14 effective full power days is sufficient to avoid exceeding the EOL limit on MTC.

c. If the measured MTC at 60 ppm is more positive than the 60 ppm Surveillance limit, the EOL limit on MTC will not be exceeded because of the gradual manner in which MTC changes with core burnup. The 60 ppm Surveillance is only performed if the 300 ppm Surveillance limit was not met (see note b). If the 60 ppm Surveillance limit is met, no further Surveillance of EOL MTC is required for the remainder of the fuel cycle. If the 60 ppm Surveillance limit is not met, then Surveillance of EOL MTC is required for the remainder of the fuel cycle as described in note b.

REFERENCES 1. 10 CFR 50, Appendix A, GDC 11.

2. UFSAR, Chapter 15. WCAP-9272-P-A, “Westinghouse Reload Safety Evaluation Methodology,” July 1985. 3. BAW 10169P-A, "B&W Safety Analysis Methodology for Recirculating Steam Generator Plants," October 1989.

4. UFSAR, Section 15.2.1.

SEQUOYAH – UNIT 1 B 3.1.3-6 Revision 49 Rod Group Alignment Limits B 3.1.4

BASES

ACTIONS (continued)

B.2.2, B.2.3, B.2.4, B.2.5, and B.2.6

For continued operation with a misaligned rod, reactor power RTP must be reduced, SDM must periodically be verified within limits, hot N channel factors (FQ(X,Y,Z) and F ǻ+(X,Y) must be verified within limits, and the safety analyses must be re-evaluated to confirm continued operation is permissible.

Reduction of power to less than or equal to 75% RTP ensures that local LHR increases resulting from a misaligned RCCA will not cause the core design criteria to be exceeded (Ref. 5). The Completion Time of 2 hours gives the operator sufficient time to accomplish an orderly power reduction without challenging the Reactor Trip Protection System.

When a rod is known to be misaligned, there is a potential to impact the SDM. Since the core conditions can change with time, periodic verification of SDM is required. A Frequency of 12 hours is sufficient to ensure this requirement continues to be met.

C W Verifying that FQ(X,Y,Z), as approximated by FQ (Z) and FQ (Z), and N F ǻ+(X,Y) are within the required limits ensures that current operation at ” 75% RTP with a rod misaligned is not resulting in power distributions that may invalidate safety analysis assumptions at full power. The Completion Time of 72 hours allows sufficient time to obtain flux maps of the core power distribution using core power distribution measurement information the incore flux mapping system and to calculate FQ(X,Y,Z) N and F ǻ+(X,Y).

Once current conditions have been verified acceptable, time is available to perform evaluations of accident analysis to determine that core limits will not be exceeded during a Design Basis Event for the duration of operation under these conditions. The accident analyses presented in UFSAR Chapter 15 (Ref. 5) that may be adversely affected will be evaluated to ensure that the analysis results remain valid for the duration of continued operation under these conditions. A Completion Time of 5 days is sufficient time to obtain the required input data and to perform the analysis.

C.1

When Required Actions cannot be completed within their Completion Time, the unit must be brought to a MODE in which the LCO requirements are not applicable. To achieve this status, the unit must be brought to at least MODE 3 within 6 hours, which

SEQUOYAH – UNIT 1 B 3.1.4-6 Revision 45

Rod Position Indication B 3.1.7

BASES

ACTIONS The ACTIONS Table is modified by a Note indicating that a separate Condition entry is allowed for each inoperable rod position indicator and each demand position indicator. This is acceptable because the Required Actions for each Condition provide appropriate compensatory actions for each inoperable position indicator.

A second Note has been added to provide clarification that LCO 3.0.4.a and LCO 3.0.4.b are not applicable for Required Action A.2.1 and A.2.2 following startup from a refueling outage, or following entry into MODE 5 of sufficient duration to safely repair an inoperable rod position indication.

A.1

When one Rod Position Indication channel per bank fails, the position of the rod may be determined indirectly by use of core power distribution measurement informationthe movable incore detectors. Core power distribution measurement information can be obtained from flux maps using the movable incore detectors, or from a functional power distribution monitoring system (PDMS). Based on experience, normal power operation does not require excessive movement of banks. If a bank has been significantly moved, the Required Action of C.1 or C.2 below is required. Therefore, verification of RCCA position within the Completion Time of 12 hours is adequate for allowing continued full power operation, since the probability of simultaneously having a rod significantly out of position and an event sensitive to that rod position is small.

A.2.1 and A.2.2

When one RPI channel per bank fails, the position of the rod may still be determined indirectly by use of core power distribution measurement information the movable incore detectors and reviewing the parameters of the rod control system for indications of unintended rod movement for the rod with the inoperable position indication. Therefore, verification of RCCA position within 8 hours, and once per every 31 days thereafter, prior to increasing THERMAL POWER above 50% RTP, and within 8 hours after reaching 100% RTP is adequate for allowing continued full power operation as long as a review of the parameters of the rod control system for indications of unintended rod movement for the rod with the inoperable position indication is performed within 16 hours and once per every 8 hours thereafter. Furthermore, if the rod control system parameters indicate unintended movement or if the rod with an inoperable position indicator is moved greater than 12 steps, then the verification of the RCCA position must be performed within 8 hours. As long as these compensatory actions are met, reactor operation can then continue until the end of the current cycle or until an entry into MODE 5 of sufficient duration that the repair of the inoperable rod position indication can safely

SEQUOYAH – UNIT 1 B 3.1.7-5 Revision 45

Rod Position Indication B 3.1.7

BASES

ACTIONS (continued) be performed.

Required Actions A.2.1 and A.2.2 are modified by a Note directing that these Required Actions may only be applied to one inoperable rod position indicator.

A.3

Reduction of THERMAL POWER to < 50% RTP puts the core into a condition where rod position is not significantly affecting core peaking factors (Ref. 3).

The allowed Completion Time of 8 hours is reasonable, based on operating experience, for reducing power to < 50% RTP from full power conditions in an orderly manner without challenging plant systems and allowing for rod position determination by Required Action A.1 above.

B.1, B.2, B.3, and B.4

When more than one Rod Position Indication per bank fails, additional actions are necessary to ensure that acceptable power distribution limits are maintained, minimum SDM is maintained, and the potential effects of rod misalignment on associated accident analyses are limited. Placing the Rod Control System in manual assures unplanned rod motion will not occur. Together with the indirect position determination available using core power distribution measurement information via movable incore detectors will minimize the potential for rod misalignment. The immediate Completion Time for placing the Rod Control System in manual reflects the urgency with which unplanned rod motion must be prevented while in this Condition.

Monitoring and recording reactor coolant Tavg helps assure that significant changes in power distribution and SDM are avoided. The once per hour Completion Time is acceptable because only minor fluctuations in RCS temperature are expected at steady state plant operating conditions.

The position of the rods may be determined indirectly by use of core power distribution measurement information.the movable incore detectors. Verification of control rod position once per 12 hours is adequate for allowing continued full power operation for a limited, 24 hour period, since the probability of simultaneously having a rod significantly out of position and an event sensitive to that rod position is small. The 24 hour Completion Time for Required Action C.4 provides sufficient time to troubleshoot and restore the Rod Position Indication System to OPERABLE status operation while avoiding the plant challenges associated with the shutdown without full rod position indication.

SEQUOYAH – UNIT 1 B 3.1.7-6 Revision 45

Rod Position Indication B 3.1.7

BASES

ACTIONS (continued)

Based on operating experience, normal power operation does not require excessive rod movement. If one or more rods has been significantly moved, the Required Action of C.1 or C.2 below is required.

C.1 and C.2

These Required Actions clarify that when one or more rods with inoperable DRPIs have been moved in excess of 24 steps in one direction, since the position was last determined, position verification the Required Actions of A.1 and A.2 or B.1 are still appropriate but must be initiated promptly under Required Action C.1 to begin indirectly verifying that these rods are still properly positioned, relative to their group positions.

If Required Action C.1 is not met, If, the rod positions have not been determined, THERMAL POWER must be reduced to < 50% RTP within 8 hours to avoid undesirable power distributions that could result from continued operation at • 50% RTP, if one or more rods are misaligned by more than 24 steps.

The allowed Completion Time of 8 hours for Required Action C.2 is reasonable, based on operating experience, for reducing power to < 50% RTP from full power conditions in an orderly manner without challenging plant systems.

D.1.1 and D.1.2

With one demand position indicator per bank inoperable, the rod positions can be determined by the Rod Position Indication System. Since normal power operation does not require excessive movement of rods, verification by administrative means that the rod position indicators are OPERABLE and the most withdrawn rod and the least withdrawn rod are ”VWHSVDSDUWZLWKLQWKHDOORZHG&RPSOHWLRQ7LPHRIRQFH every 12 hours is adequate.

D.2

Reduction of THERMAL POWER to < 50% RTP puts the core into a condition where rod position is not significantly affecting core peaking factor limits (Ref. 3). The allowed Completion Time of 8 hours provides an acceptable period of time to verify the rod positions per Required Actions D.1.1 and D.1.2 C.1 and C.2 or reduce power to < 50% RTP from full power conditions in an orderly manner without challenging plant systems.

E.1

SEQUOYAH – UNIT 1 B 3.1.7-7 Revision 45 PHYSICS TESTS Exceptions - MODE 2 B 3.1.8

BASES

BACKGROUND (continued)

The PHYSICS TESTS required for reload fuel cycles (Ref. 4) in MODE 2 are listed below:

a. Critical Boron Concentration - Control Rods Withdrawn;

b. Critical Boron Concentration - Control Rods Inserted;

c. Control Rod Worth; and e. Neutron Flux Symmetry d. Isothermal Temperature Coefficient (ITC).

These and other supplementary tests may be required to calibrate the nuclear instrumentation or to diagnose operational problems. These tests may cause the operating controls and process variables to deviate from their LCO requirements during their performance.

a. The Critical Boron Concentration - Control Rods Withdrawn Test measures the critical boron concentration at hot zero power (HZP). With all rods out, the lead control bank is at or near its fully withdrawn position. HZP is where the core is critical (keff = 1.0), and the Reactor Coolant System (RCS) is at design temperature and pressure for zero power. Performance of this test should not violate any of the referenced LCOs.

b. The Critical Boron Concentration - Control Rods Inserted Test measures the critical boron concentration at HZP, with a bank having a worth of at least 1% ¨k/k when fully inserted into the core. This test is used to measure the boron reactivity coefficient. With the core at HZP and all banks fully withdrawn, the boron concentration of the reactor coolant is gradually lowered in a continuous manner. The selected bank is then inserted to make up for the decreasing boron concentration until the selected bank has been moved over its entire range of travel. The reactivity resulting from each incremental bank movement is measured with a reactivity computer. The difference between the measured critical boron concentration with all rods fully withdrawn and with the bank inserted is determined. The boron reactivity coefficient is determined by dividing the measured bank worth by the measured boron concentration difference. Performance of this test could violate LCO 3.1.4, "Rod Group Alignment Limits," LCO 3.1.5, "Shutdown Bank Insertion Limit," or LCO 3.1.6, "Control Bank Insertion Limits."

SEQUOYAH – UNIT 1 B 3.1.8-2 Revision 45 PHYSICS TESTS Exceptions - MODE 2 B 3.1.8

BASES

BACKGROUND (continued)

c. The Control Rod Worth Test is used to measure the reactivity worth of selected control banks. This test is performed at HZP and has three alternative methods of performance. The first method, the Boron Exchange Method, varies the reactor coolant boron concentration and moves the selected control bank in response to the changing boron concentration. The reactivity changes are measured with a reactivity computer. This sequence is repeated for the remaining control banks. The second method, the Rod Swap Method, measures the worth of a predetermined reference bank using the Boron Exchange Method above. The reference bank is then nearly fully inserted into the core. The selected bank is then inserted into the core as the reference bank is withdrawn. The HZP critical conditions are then determined with the selected bank fully inserted into the core. The worth of the selected bank is inferred, based on the position of the reference bank with respect to the selected bank. This sequence is repeated as necessary for the remaining control banks. The third method, the Boron Endpoint Method, moves the selected control bank over its entire length of travel and then varies the reactor coolant boron concentration to achieve HZP criticality again. The difference in boron concentration is the worth of the selected control bank. This sequence is repeated for the remaining control banks. Performance of this test could violate LCO 3.1.4, LCO 3.1.5, or LCO 3.1.6.

d. The ITC Test measures the ITC of the reactor. This test is performed at HZP and has two methods of performance. The first method, the Slope Method, varies RCS temperature in a slow and continuous manner. The reactivity change is measured with a reactivity computer as a function of the temperature change. The ITC is the slope of the reactivity versus the temperature plot. The test is repeated by reversing the direction of the temperature change, and the final ITC is the average of the two calculated ITCs. The second method, the Endpoint Method, changes the RCS temperature and measures the reactivity at the beginning and end of the temperature change. The ITC is the total reactivity change divided by the total temperature change. The test is repeated by reversing the direction of the temperature change, and the final ITC is the average of the two calculated ITCs. Performance of this test could violate LCO 3.4.2, "RCS Minimum Temperature for Criticality."

AddInsert e on following page

SEQUOYAH – UNIT 1 B 3.1.8-3 Revision 45

e. The Flux Symmetry Test measures the degree of azimuthal symmetry of the neutron flux at as low a power level as practical, depending on the test method employed. This test can be performed at HZP (Control Rod Worth ^LJŵŵĞƚƌLJDĞƚŚŽĚͿŽƌĂƚчϱ0% RTP (Flux Distribution Method). The Control Rod Worth Symmetry Method inserts a control bank, which can then be withdrawn to compensate for the insertion of a single control rod from a symmetric set. The symmetric rods of each set are then tested to evaluate the symmetry of the control rod worth and neutron flux (power distribution). A reactivity computer is used to measure the control rod worths. Performance of this test could violate LCO 3.1.4, >Kϯ͘ϭ͘ϱ͕Žƌ>Kϯ͘ϭ͘ϲ͘dhe Flux Distribution Method uses the incore flux detectors to measure the azimuthal flux distribution at selecteĚůŽĐĂƚŝŽŶƐǁŝƚŚƚŚĞĐŽƌĞĂƚчϱ0% RTP. PHYSICS TESTS Exceptions - MODE 2 B 3.1.8 Westinghouse Reload Safety Evaluation Methodology Report BASES

APPLICABLE The fuel is protected by LCOs that preserve the initial conditions of the SAFETY core assumed during the safety analyses. The methods for development ANALYSES of the LCOs that are excepted by this LCO are described in the Core Operating Limit Methodology for Westinghouse Designed PWRs (Ref. 5). The above mentioned PHYSICS TESTS, and other tests that may be required to calibrate nuclear instrumentation or to diagnose operational problems, may require the operating control or process variables to deviate from their LCO limitations.

The UFSAR defines requirements for initial testing of the facility, including PHYSICS TESTS. Table 14.1-2 summarizes the zero, low power, and power tests. Requirements for reload fuel cycle PHYSICS TESTS are defined in ANSI/ANS-19.6.1-1997 (Ref. 4). Although these PHYSICS TESTS are generally accomplished within the limits for the LCOs, conditions may occur when one or more LCOs must be suspended to make completion of PHYSICS TESTS possible or practical. This is acceptable as long as the fuel design criteria are not violated. When one or more of the requirements specified in LCO 3.1.3, "Moderator Temperature Coefficient (MTC)," LCO 3.1.4, LCO 3.1.5, LCO 3.1.6, and LCO 3.4.2 are suspended for PHYSICS TESTS, the fuel design criteria DUHSUHVHUYHGDVORQJDVWKHSRZHUOHYHOLVOLPLWHGWR” 5% RTP, the UHDFWRUFRRODQWWHPSHUDWXUHLVNHSW• 531°F, and SDM is within the limits provided in the COLR.

The PHYSICS TESTS include measurement of core nuclear parameters or the exercise of control components that affect process variables. Among the process variables involved are AFD and QPTR, representing initial conditions of the unit safety analyses. Also involved are the movable control components (control and shutdown rods), that are required to shut down the reactor. The limits for these variables are specified for each fuel cycle in the COLR.

As described in LCO 3.0.7, compliance with Test Exception LCOs is optional, and therefore no criteria of 10 CFR 50.36(c)(2)(ii) apply. Test Exception LCOs provide flexibility to perform certain operations by appropriately modifying requirements of other LCOs. A discussion of the criteria satisfied for the other LCOs is provided in their respective Bases.

Reference 6 allows special test exceptions (STEs) to be included as part of the LCO that they affect. It was decided, however, to retain this STE as a separate LCO because it was less cumbersome and provided additional clarity.

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BASES

REFERENCES 1. 10 CFR 50, Appendix B, Section XI.

2. 10 CFR 50.59.

3. Regulatory Guide 1.68, Revision 2, August, 1978.

4. ANSI/ANS-19.6.1-1997.

5. BAW-10163P-A, “Core Operating Limit Methodology for Westinghouse Designed PWRs,” June 1989.

5. WCAP-9272-P-A, “Westinghouse Reload Safety Evaluation Methodology,” July 1985.

6. WCAP-11618, including Addendum 1, April 1989.

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) F (Z) (RAOC-T(Z) Methodology) Q FQ(X,Y,Z) B 3.2.1

B 3.2 POWER DISTRIBUTION LIMITS

B 3.2.1 Heat Flux Hot Channel Factor (FQ(X,Y,Z)) (RAOC-T(Z) Methodology)

BASES

BACKGROUND The purpose of the limits on the values of FQ(X,Y,Z) is to limit the local (i.e., pellet) peak power density. The value of FQ(X,Y,Z) varies along the axial height (Z) of the core and by assembly location, X, Y.

FQ(X,Y,Z) is defined as the maximum local fuel rod linear power density divided by the average fuel rod linear power density. Therefore, FQ(X,Y,Z) is a measure of the peak fuel pellet power within the reactor core. density, assuming nominal fuel pellet and fuel rod dimensions.

During power operation, the global power distribution is limited by LCO 3.2.3, "AXIAL FLUX DIFFERENCE (AFD)," and LCO 3.2.4, "QUADRANT POWER TILT RATIO(QPTR)," which are directly and continuously measured process variables. These LCOs, along with LCO 3.1.6, "Control Bank Insertion Limits," maintain the core limits on core power distribution power distributions on a continuous basis. measurement information FQ(X,Y,Z) varies with fuel loading patterns, control bank insertion, fuel obtained from either flux burnup, and changes in axial power distribution. maps using the movable incore detectors or from a FQ(X,Y,Z) is measured periodically using the incore detector system. functional power distribution These measurements are generally taken with the core at or near monitoring system (PDMS). equilibrium conditions. three-dimensional

Using the measured three dimensional power distributions, it is possible to derive a measured value for FQ(X,Y,Z). However, because this value represents an equilibrium condition, it does not include the variations in the value of FQ(X,Y,Z) which are present during nonequilibrium situations such as load following or power ascension. Note: add Insert 3.2.1-A. non-equilibrium To account for these possible variations, "the FQ(X,Y,Z) limits, BQDES(X,Y,Z) and BCDES(X,Y,Z), have been adjusted by pre-calculated factors (MQ(X,Y,Z) and MC(X,Y,Z) respectively) to account for the calculated worst case transient conditions."

Core monitoring and control under non-equilibrium conditions are accomplished by operating the core within the limits of the appropriate LCOs, including the limits on AFD, QPTR, and control rod insertion.

bank

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10 CFR 50.46 acceptance criteria must be met BASES

APPLICABLE This LCO precludes core power distributions that violate the following SAFETY fuel design criteria: ANALYSES a. During a large break loss of coolant accident (LOCA), the peak transient conditions cladding temperature must not exceed 2200°F (Ref. 1), arising from events of moderate frequency b. During a loss of forced reactor coolant flow accident, there must be at (Condition II events), least 95% probability at the 95% confidence level (the 95/95 DNB criterion) that the hot fuel rod in the core does not experience a departure from nucleate boiling (DNB) condition,

c. During an ejected rod accident, the energy deposition to the fuel must not exceed 280 cal/gm (Ref. 2), and 200 d. The control rods must be capable of shutting down the reactor with a minimum required SDM with the highest worth control rod stuck fully withdrawn (Ref. 3).

Limits on FQ(X,Y,Z) ensure that the value of the initial total peaking factor assumed in the accident analyses remains valid. Other criteria must also be met (e.g., maximum cladding oxidation, maximum hydrogen generation, coolable geometry, and long term cooling). However, the peak cladding temperature is typically most limiting.

FQ(X,Y,Z) limits assumed in the LOCA analysis are typically limiting relative to (i.e., lower than) the FQ(X,Y,Z) limit assumed in safety analyses for other postulated accidents. Therefore, this LCO provides conservative limits for other postulated accidents.

FQ(X,Y,Z) satisfies Criterion 2 of 10 CFR 50.36(c)(2)(ii).

LCO The Heat Flux Hot Channel Factor, FQ(X,Y,Z), shall be limited by the following relationships:

౎౐ౌ FQ ;<= ” (F్ / P) K(Z) for P > 0.5

౎౐ౌ FQ(X,Y,Z) ” (F్ / 0.5) K(Z) IRU3” 0.5

౎౐ౌ where: F్ is the FQ(X,Y,Z) limit at RTP provided in the COLR,

K(Z) is the normalized FQ(X,Y,Z) as a function of core height provided in the COLR, and limit P = THERMAL POWER / RTP

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LCO (continued) . ౎౐ౌ For SQN, the actual values of F్ and K(Z) are given in the COLR;

౎౐ౌ however, F్ is normally a number on the order of 2.62. For Relaxed Axial Offset Measured FQ(X,Y,Z) is compared against three limits: Control operation, FQ(Z) is C ౎౐ౌ approximated by FQ (Z) and x Steady state limit, (F్ / P) * K(Z), W C FQ (Z). Thus both FQ (Z) and F W(Z) must meet the x Limiting condition LOCA limit, BQDES(X,Y,Z), and Q preceding limits on FQ(Z). x Limiting condition centerline fuel melt limit, BCDES(X,Y,Z). a core power distribution F (X,Y,Z) is approximated by C )Z,Y,X(F for the steady state limit on measurement in MODE 1 Q Q C obtained from flux maps FQ(X,Y,Z). An Q )Z,Y,X(F evaluation requires using the moveable incore using the movable incore detectors to obtain a power distribution map in MODE 1. From the incore detectors or from a M flux map results we obtain the measured value (FQ (X,Y,Z)) of FQ(X,Y,Z). functional power Then, distribution monitoring is obtained. C system (PDMS) from Q )Z,Y,X(F = overall measured FQ(X,Y,Z) * 1.05 * 1.03 which a where, 1.05 is the measurement reliability factor that accounts for flux map measurement uncertainty (Reference 5) and 1.03 is the local engineering heat flux hot channel factor to account for fuel rod manufacturing tolerance (Reference 4).

BQDES(X,Y,Z) and BCDES(X,Y,Z) are cycle dependent design limits to ensure the FQ(X,Y,Z) limit is met during transients. An evaluation of these limits requires obtaining an incore flux map in MODE 1. From the incore flux map results we obtain the assembly nodal measured value M M ( Q )Z,Y,X(F ) of FQ(X,Y,Z). Q )Z,Y,X(F is compared directly to the limits BQDES(X,Y,Z) and BCDES(X,Y,Z). This is appropriate since BQDES(X,Y,Z) and BCDES(X,Y,Z) have been adjusted for uncertainties.

The expression for BQDES(X,Y,Z) is: BQDES(X,Y,Z) = Pd(X,Y,Z) * MQ(X,Y,Z) * NRF * F1 / MRF

Note: add Insert 3.2.1-B.

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LCO (continued)

where:

x BQDES(X,Y,Z) is the cycle dependent maximum allowable design peaking factor for fuel assembly X,Y at axial location Z. BQDES(X,Y,Z) ensures that the LOCA limit will be preserved for operation within the LCO limits, including allowances for calculational and measurement uncertainties; x Pd(X,Y,Z) is the design power distribution for fuel assembly X,Y at axial location Z, including the operational flexibility factor; x MQ(X,Y,Z) is the minimum available margin ratio for the LOCA limit at assembly X,Y and axial location Z; x NRF is the nuclear reliability factor; x F1 is the spacer grid factor; x MRF is measurement reliability factor.

The expression for BCDES(X,Y,Z) is: BCDES(X,Y,Z) = Pd(X,Y,Z) * MC(X,Y,Z) * NRF * F1 / MRF

where:

x BCDES(X,Y,Z) is the cycle dependent maximum allowable design peaking factor for fuel assembly X,Y, at axial location Z. BCDES(X,Y,Z) ensures that the centerline fuel melt limit will be preserved for operation within the LCO limits, including allowances for calculational and measurement uncertainties;

x MC(X,Y,Z) is the minimum available margin ratio for the centerline fuel melt limit at assembly X,Y and axial location Z;

The reactor core is operating as designed if the measured steady state core power distribution agrees with prediction within statistical variation. This guarantees that the operating limits will preserve the thermal criteria in the applicable safety analyses. The core is operating as designed if the following relationship is satisfied:

M Q )Z,Y,X(F ”%4120 X,Y,Z)

where:

x BQNOM(X,Y,Z) is the nominal design peaking factor for assembly X,Y at axial location Z increased by an allowance for the expected deviation between the measured and predicted design power distribution.

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LCO (continued)

Violating the LCO limits The FQ(X,Y,Z) limits define limiting values for core power peaking that for FQ(Z) could result in precludes peak cladding temperatures above 2200°F during either a large unacceptable or small break LOCA. ensure that the 10 CFR 50.46 acceptance criteria consequences if a are met during a LOCA. design basis event were BQNOM (X,Y,Z), BQDES(X,Y,Z), and BCDES(X,Y,Z) Data bases are provided for the plant power distribution analysis computer codes on a to occur while F (Z) Q cycle specific basis and are determined using the methodology for core exceeds its specified limit generation described in the references in the COLR. limits. This LCO requires operation within the bounds assumed in the safety W required, and if FQ (Z) analyses. Calculations are performed in the core design process to cannot be maintained confirm that the core can be controlled in such a manner during operation C within the LCO limits, a that it can stay within the LOCA FQ(X,Y,Z) limits. If FQ (X,Y,Z) cannot be more restrictive RAOC maintained within the LCO limits, reduction of the core power is required. operating space must Note that sufficient reduction of the AFD limits will also result in a be implemented or core reduction of the core power. power limits and AFD Violating the LCO limits for F (X,Y,Z) produces unacceptable limits (Ref. 6) must be Q consequences if a design basis event occurs while FQ(X,Y,Z) is outside reduced. its specified limits.

APPLICABILITY The FQ(X,Y,Z) limits must be maintained in MODE 1 to prevent core power distributions from exceeding the limits assumed in the safety analyses. Applicability in other MODES is not required because there is either insufficient stored energy in the fuel or insufficient energy being transferred to the reactor coolant to require a limit on the distribution of core power.

ACTIONS A.1

5HGXFLQJ7+(50$/32:(5E\• 1% RTP for each 1% by which C factors FQ (X,Y,Z) exceeds its limit, maintains an acceptable absolute power C M density. FQ (X,Y,Z) is FQ (X,Y,Z) multiplied by a factor accounting for M manufacturing tolerances and measurement uncertainties. FQ (X,Y,Z) is the measured value of FQ(X,Y,Z). The Completion Time of 15 minutes provides an acceptable time to reduce power in an orderly manner and without allowing the plant to remain in an unacceptable condition for an extended period of time. The maximum allowable power level initially determined by Required Action A.1 may be affected by subsequent

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ACTIONS (continued) that are not within limit and could subsequent C determinations of FQ (X,Y,Z) and would require power reductions within 15 C In short, the 15-minute minutes of the FQ (X,Y,Z) determination, if necessary to comply with the C Completion Time for decreased maximum allowable power level. Decreases in FQ (X,Y,Z) Required Action A.1 would allow increasing the maximum allowable power level and applies after each increasing power up to this revised limit. Q F C(Z) determination.

A.2 Note: add Insert 3.2.1-C. Required Action A.2 requires an administrative reduction of the AFD limits C E\• 1% for each 1% by which FQ (X,Y,Z) exceeds the steady state limit. The allowed Completion Time of 2 hours, restricts the axial flux distribution such that even if a transient occurred, core peaking factor limits are not exceeded. The maximum allowable AFD limits initially determined by Required Action A.2 may be affected by subsequent C determinations of FQ (X,Y,Z) and would require further AFD limit C reductions within 2 hours of the FQ (X,Y,Z) determination, if necessary to comply with the decreased maximum allowable AFD limits. Decreases in C FQ (X,Y,Z) would allow increasing the maximum allowable AFD limits.

Note: add Insert 3.2.1-D. A.3

5HGXFWLRQLQWKH2YHUSRZHU¨7WULSVHWSRLQWV YDOXHRI.4 E\• LQ¨7 that THERMAL C span for each 1% by which F (X,Y,Z) exceeds its limit, is a conservative POWER is limited Q 72 action for protection against the consequences of severe transients with below RATED unanalyzed power distributions. The Completion Time of 48 hours is F C(Z) that THERMAL POWER by Q sufficient considering the small likelihood of a severe transient in this timeare not Required Action A.1 period, and the preceding prompt reduction in THERMAL POWER in within limit accordance with Required Action A.1. The maximum allowable and could 2YHUSRZHU¨7WULSVHWSRLQWVLQLWLDOO\GHWHUPLQHGE\5HTXLUHG$FWLRn A.3 C may be affected by subsequent determinations of FQ (X,Y,Z) and would UHTXLUH2YHUSRZHU¨7WULSVHWSRLQWUHGXFWLRQVZLWKLQKRXUVRIWKH C F (X,Y,Z) determination, if necessary to comply with the decreased subsequent Q C 72 maximum allowable OYHUSRZHU¨7WULSVHWSRLQWV'HFUHDVHVLQFQ (X,Y,Z) ZRXOGDOORZLQFUHDVLQJWKHPD[LPXPDOORZDEOH2YHUSRZHU¨7WULS setpoints. In short, the 72-hour Completion Time for C Required Action A.3 applies after each FQ (Z) C determination. Decreases in subsequent FQ (Z) measurements while in Condition A

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ACTIONS (continued)

A.4

A reduction of the Power Range Neutron Flux - High trip setpoints by C • 1% for each 1% by which FQ (X,Y,Z) exceeds its limit, is a conservative action for protection against the consequences of severe transients with unanalyzed power distributions. The Completion Time of 72 hours is sufficient considering the small likelihood of a severe transient in this time period and the preceding prompt reduction in THERMAL POWER in accordance with Required Action A.1. The maximum allowable Power Range Neutron Flux - High trip setpoints initially determined by Required C Action A.4 may be affected by subsequent determinations of FQ (X,Y,Z) and would require Power Range Neutron Flux - High trip setpoint C reductions within 72 hours of the FQ (X,Y,Z) determination, if necessary to comply with the decreased maximum allowable Power Range Neutron C Flux - High trip setpoints. Decreases in FQ (X,Y,Z) would allow increasing the maximum allowable Power Range Neutron Flux - High trip setpoints. A.4

A.5 SR 3.2.1.1 and SR 3.2.1.2 C Verification that FQ (X,Y,Z) has been restored to within its steady state and transient limit, by performing SR 3.2.1.1, SR 3.2.1.2 and SR 3.2.1.3 prior to increasing THERMAL POWER above the limit imposed by Required Action A.1, ensures that core conditions during operation at higher power levels and future operation are consistent with safety analyses prior to increasing assumptions.

THERMAL POWER C Since F (X,Y,Z) exceeds the steady state limit, the limiting condition above the limit of Q operational limit (BQDES) and the limiting condition Reactor Protection required Action A.1. The System limit (BCDES) may also be exceeded. By performing SR 3.2.1.2 note also states that SR and SR 3.2.1.3, appropriate actions with respect to reductions in AFD 3.2.1.2 is not required to OLPLWVDQG23ǻ7WULSVHWSRLQWVZLOOEHSHUIRUPHGHQVXULQJWKDWFRUH be performed if this conditions during operational and Condition II transients are maintained Condition is entered within the bounds of the safety analysis. A.4 prior to THERMAL POWER exceeding 75% Condition A is modified by a Note that requires Required Action A.5 to be performed whenever the Condition is entered. This ensures that RTP after a refueling. SR 3.2.1.1, SR 3.2.1.2 and SR 3.2.1.3 will be performed prior to A.4 increasing THERMAL POWER above the limit of Required Action A.1, even when Condition A is exited prior to performing Required Action A.5. Performance of SR 3.2.1.1, SR 3.2.1.2 and SR 3.2.1.3 are necessary to SR 3.2.1.1 and C assure F (X,Y,Z) is properly evaluated prior to increasing THERMAL SR 3.2.1.2 Q POWER. (if required) SR 3.2.1.1 and SR 3.2.1.2 is

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ACTIONS (continued)

Note: add Insert 3.2.1-E. B.1 and B.2

The FQ(X,Y,Z) margin supporting AFD operational limits (AFD margin) M during transient operations is based on the relationship between FQ (X,Y,Z) and the limiting condition operational limit, BQDES (X,Y,Z), as follows:

§ M ZYXF ),,( · ¨ Q ¸ ¨1 ¸ 100%* %AFD margin = © BQDES ZYX ),,( ¹

The AFD min margin = minimum % margin value of all locations M examined. If the reactor core is operating as designed, then FQ (X,Y,Z) is less than BQDES (X,Y,Z) and calculation of %AFD margin is not required. M If the AFD margin is less than zero, then FQ (X,Y,Z) is greater than BQDES (X,Y,Z) and the AFD limits may not be adequate to prevent exceeding the peaking criteria for a LOCA if a normal operational transient occurs.

Required Actions B.1 and B.2 require reducing the AFD limit lines as follows. The AFD limit reduction is from the full power AFD limits. The adjusted AFD limits must be used until a new measurement shows that a smaller adjustment can be made to the AFD limits, or that no adjustment is necessary:

APL = PAFDL – Absolute Value of (PSLOPEAFD * % AFD Margin) AFD ANL = NAFDL + Absolute Value of (NSLOPE * % AFD Margin)

where,

x APL is the adjusted positive AFD limit. x ANL is the adjusted negative AFD limit. x PAFDL is the positive AFD limit defined in the COLR. x NAFDL is the negative AFD limit defined in the COLR. x PSLOPEAFD is the adjustment to the positive AFD limit required to M compensate for each 1% that FQ (X,Y,Z) exceeds BQDES (X,Y,Z) as defined in the COLR. x NSLOPEAFD is the adjustment to the negative AFD limit required to M compensate for each 1% that FQ (X,Y,Z) exceeds BQDES (X,Y,Z) as defined in the COLR. x % AFD Margin is the most negative margin determined above.

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ACTIONS (continued)

Completing Required Actions B.1 and B.2 within the allowed Completion Time of 2 hours, restricts the axial flux distribution such that even if a transient occurred, core peaking factor limits are not exceeded.

C.1 and C.2

The FQ(X,Y,Z) margin supportiQJWKH2YHUSRZHUǻ7I2 ǻ, EUHDNSRLQWV (f2 ǻ, PDUJLQ GXULQJ transient operations is based on the relationship M between FQ (X,Y,Z) and the limit, BCDES(X,Y,Z), as follows:

§ M ZYXF ),,( · ¨1 Q ¸ 100%* % f ǻ, PDUJLQ  ¨ ¸ 2 © BCDES ZYX ),,( ¹

The f2 ǻ, PLQPDUJLQ PLQLPXPPDUJLQYDOXHRIDOOORFDWLRQV M examined. If the reactor core is operating as designed, then FQ (X,Y,Z) is less than BCDES(X,Y,Z) and calculation of % f2 ǻ, PDUJLQLVQRW M required. If the f2 ǻ, PDUJLQLVOHVVWKDQzero, then FQ (X,Y,Z) is greater than BCDES(X,Y,Z) and there is a potential that the f2 ǻ, OLPLWVDUH insufficient to preclude centerline fuel melt during certain transients.

Required Actions C.1 and C.2 require reducing the f 2 ǻ, EUHDNSRLnt limits as follows. The f2 ǻ, EUHDNSRLQWlimit reduction is always from the full power f2 ǻ, EUHDNSRLQWlimits. The adjusted f2 ǻ, EUHDNSRLQWlimits must be used until a new measurement shows that a smaller adjustment can be made to the f2 ǻ, EUHDNSRLQWlimits, or that no adjustment is necessary.

Limit I ǻ, Posf2 ǻ, Adjusted = Posf2 ǻ, – Absolute Value of (PSLOPE * % f2 ǻ, 0DUJLQ Limit I ǻ, Negf2 ǻ, Adjusted = Negf2 ǻ, + Absolute Value of (NSLOPE * % f2 ǻ, 0DUJLQ

where:

x Posf2 ǻI)Adjusted LVWKHDGMXVWHG23ǻ7SRVLWLYHI2 ǻ, EUHDNSRLQW limit.

x Negf2 ǻ, Adjusted LVWKHDGMXVWHG23ǻ7QHJDWLYHI2 ǻ, EUHDNSRLQW limit. Limit x Posf2 ǻ, LVWKH23ǻ7SRVLWLYHI2 ǻ, EUHDNSRLQWOLPLWGHILQHG in the COLR. Limit x Negf2 ǻ, LVWKH23ǻ7QHJDWLYHI2 ǻ, EUHDNSRLQWOLPLWGHILQHG in the COLR.

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ACTIONS (continued)

I ǻ,  x PSLOPE LVWKHDGMXVWPHQWWRWKHSRVLWLYH23ǻ7I2 ǻ, OLPLW M required to compensate for each 1% that FQ (X,Y,Z) exceeds BCDES(X,Y,Z) as defined in the COLR. I ǻ,  x NSLOPE LVWKHDGMXVWPHQWWRWKHQHJDWLYH23ǻ7I2 ǻ, OLPLW M required to compensate for each 1% that FQ (X,Y,Z) exceeds BCDES(X,Y,Z) as defined in the COLR.

x % f2 ǻ, 0DUJLQLVWKHPRVWQHJDWLYHPDUJLQGHWHUPLQHGDERYH.

Completing Required Actions C.1 and C.2 is a conservative action for protection against the consequences of transients since this adjustment limits the peak transient power level which can be achieved during an anticipated operational occurrence. Completing Required Actions C.1 and C.2 within the allowed Completion Time of 48 hours is sufficient C.1 considering the small likelihood of a limiting transient in this time period.

A.1 through A.4, B.1.1 and B.1.2, or B.2.1 through B.2.4 D.1

If Required Actions A.1 through A.5, B.1, B.2, C.1 or C.2 are not met within their associated Completion Times, the plant must be placed in a mode or condition in which the LCO requirements are not applicable. This is done by placing the plant in at least MODE 2 within 6 hours.

This allowed Completion Time is reasonable based on operating experience regarding the amount of time it takes to reach MODE 2 from full power operation in an orderly manner and without challenging plant systems.

SURVEILLANCE SR 3.2.1.1, SR 3.2.1.2 and SR 3.2.1.3 are modified by a Note. REQUIREMENTS It states that Surveillance performance is not required until 12 hours after an equilibrium power level has been achieved at which a power distribution map can be obtained. This allowance is modified, however, by one of the Frequency conditions that requires verification that C M

FQ (X,Y,Z) and FQ (X,Y,Z) are within their specified limits after a power rise of more than 10% RTP over the THERMAL POWER at which they were C last verified to be within specified limits. Because FQ (X,Y,Z) and M FQ (X,Y,Z) could not have previously been measured in this reload core, there is a second Frequency condition, applicable only for reload cores, that requires determination of these parameters before exceeding C 75% RTP. This ensures that some determination of FQ (X,Y,Z) and M FQ (X,Y,Z) are made at a lower power level at which adequate margin is available before going to 100% RTP. Also, this Frequency condition, C together with the Frequency condition requiring verification of FQ (X,Y,Z) M and FQ (X,Y,Z) following a power increase of more than 10%, ensures that

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SURVEILLANCE REQUIREMENTS (continued)

they are verified as soon as RTP (or any other level for extended operation) is achieved. In the absence of these Frequency conditions, it is possible to increase power to RTP and operate for 31 days without C M

verification of FQ (X,Y,Z) and FQ (X,Y,Z). The Frequency condition is not intended to require verification of these parameters after every 10% increase in power level above the last verification. It only requires verification after a power level is achieved for extended operation that is 10% higher than that power at which FQ(X,Y,Z) was last measured.

C Verification FQ (Z) as described in the LCO Bases SR 3.2.1.1

C M Direct verification that FQ (X,Y,Z) is within its specified limits involves increasing FQ (Z) increasing the overall measured FQ(X,Y,Z) to allow for manufacturing C tolerance and measurement uncertainties in order to obtain FQ (X,Y,Z). C FQ (X,Y,Z) is then compared to its specified limits.

C The limit with which FQ (X,Y,Z) is compared varies inversely with power above 50% RTP and directly with a function called K(Z) provided in the COLR.

The surveillance has been modified by a Note providing an allowance to not perform SR 3.2.1.1 if the Surveillance has been determined to be met based on the performance results of both SR 3.2.1.2 and SR 3.2.1.3. If ensures that some both the AFD min margin and the f2 ǻ, PLQPDUJLQDUH•, then the C steady state limit is met because these margins represent bounding determination of FQ (Z) limiting conditions. However, if AFD min margin or f ǻ, PLQPDUJLQLV is made prior to 2 negative then a direct evaluation of the steady state limit is required to achieving a significant satisfy this surveillance requirement. following each refueling power level where the peak linear heat rate Performing this Surveillance in MODE 1 prior to exceeding 75% RTP C initial or most could approach the limits ensures that the FQ (X,Y,Z) limit is met when RTP is achieved, because assumed in the safety peaking factors generally decrease as power level is increased. recent analyses. ,I7+(50$/32:(5KDVEHHQLQFUHDVHGE\• 10% RTP since the last C determination of FQ (X,Y,Z), another evaluation of this factor is required within 24 12 hours after achieving equilibrium conditions at this higher power level C (to ensure that FQ (X,Y,Z) values are being reduced sufficiently with power increase to stay within the LCO limits). Equilibrium Note: add Insert 3.2.1-F. conditions are The Surveillance Frequency is controlled under the Surveillance Frequency Control Program. achieved when the core is sufficiently stable at the intended operating conditions required

SEQUOYAH – UNIT 1 B 3.2.1-11 Revisionto perform 45 the surveillance. FQ(Z) (RAOC-T(Z) Methodology) FQ(X,Y,Z) B 3.2.1

BASES

SURVEILLANCE REQUIREMENTS (continued)

SR 3.2.1.2 and SR 3.2.1.3

core power distribution The nuclear design process includes calculations performed to determine measurements are that the core can be operated within the FQ(X,Y,Z) limits. Because flux maps are taken in steady state conditions, the variations in power taken at or near distribution resulting from normal operational maneuvers are not present in the flux map data. These variations are, however, conservatively in the measurements calculated by considering a wide range of unit maneuvers in normal The [T(Z)]COLR functions operation. The maximum peaking factor increase over steady state values, calculated as a function of both assembly and axial location are specified in the (X,Y,Z), has been included in the cycle specific limits BQDES(X,Y,Z) and COLR for discrete core BCDES(X,Y,Z) using margin factors MQ(X,Y,Z) and MC(X,Y,Z), elevations. Core respectively (Reference 5). measurement Note: add Insert 3.2.1-G. M information is typically No uncertainties are applied to FQ (X,Y,Z) because the limits, taken for 61 core BQDES(X,Y,Z) and BCDES(X,Y,Z), have been adjusted for uncertainties. W elevations. FQ (Z) BQDES(X,Y,Z) and BCDES(X,Y,Z) limits are not applicable for the evaluations are not following axial core regions, measured in percent of core height: applicable for axial core , regions, measured in a. Lower core region, from 0 to 15% inclusive and percent of core height: , b. Upper core region, from 85 to 100% inclusive. These regions c. Grid plane regions, The top and bottom 15% of the core are excluded from the evaluation ± 2% inclusive, and because of the low probability that these regions would be more limiting in the safety analyses and because of the difficulty of making a precise d. Core plane regions, measurement in these regions. Note: add Insert 3.2.1-H. within ± 2% of the bank demand position This Surveillance has been modified by a Note that may require that more frequent surveillances be performed based on future projections. If of the control banks. M FQ (X,Y,Z) is evaluated and found to be within the applicable limiting condition limits, an evaluation is required to account for any increase to M FQ (X,Y,Z) that may occur and cause the FQ(X,Y,Z) limit to be exceeded before the next required FQ(X,Y,Z) evaluation.

In addition to ensuring via surveillance that the heat flux hot channel factor is within its limits when a measurement is taken, there are also M requirements to extrapolate trends in FQ (X,Y,Z) for the last two measurements out to 31 EFPD beyond the most recent measurement. If M the extrapolation yields an FQ (X,Y,Z) > BQNOM(X,Y,Z), further consideration is required.

SEQUOYAH – UNIT 1 B 3.2.1-12 Revision 45 F (Z) (RAOC-T(Z) Methodology) Q FQ(X,Y,Z) B 3.2.1

BASES

SURVEILLANCE REQUIREMENTS (continued)

The implications of these extrapolations are considered separately for both the operational and RPS heat flux hot channel factor limits. If the M extrapolations of FQ (X,Y,Z) are unfavorable, additional actions must be taken. These actions are to meet the FQ(X,Y,Z) limit with the last M

FQ (X,Y,Z) increased by the appropriate factor specified in the COLR or to M evaluate FQ (X,Y,Z) prior to the projected point in time when the extrapolated values are expected to exceed the extrapolated limits. These alternative requirements prevent FQ(X,Y,Z) from exceeding its limit for any significant period of time without detection using the best available data.

Extrapolation is not required for the initial flux map taken after reaching equilibrium conditions following a refueling outage since the initial flux map establishes the baseline measurement for future trending.

FQ ;<= LVYHULILHGDWSRZHUOHYHOV• 10% RTP above the THERMAL POWER of its last verification within 12 hours after achieving equilibrium conditions to ensure that FQ(X,Y,Z) is within its limit at higher power nominal (non- levels. adequate to monitor conditional) the change of core The Surveillance Frequency is controlled under the Surveillance power distribution Frequency Control Program. with core burnup REFERENCES 1. 10 CFR 50.46, 1974. and is WCAP-18459-P, 2. Regulatory Guide 1.77, Rev. 0, May 1974. Revision 1, “Sequoyah Units 1 and 2 Reload 3. 10 CFR 50, Appendix A, GDC 26. Transition Safety Report 4. WCAP-7308-L-P-A, "Evaluation of Nuclear Hot Channelwith Factor RFA-2 Fuel,” June Uncertainties," June 1988. 2020.

5. BAW-10163PA “Core Operating Limit Methodology for Westinghouse- Designed PWRs” June 1989.

5. WCAP-10216-P-A, Rev. 1A, "Relaxation of Constant Axial Offset Control (and) FQ Surveillance Technical Specification," February 1994.

6. WCAP-17661-P-A, "Improved RAOC and CAOC FQ Surveillance Technical Specifications," February 2019.

7. WCAP-12472-P-A, "BEACON Core Monitoring and Operations Support System," August 1994; and WCAP-12472-P-A, Addendum 4, "BEACONTM Core Monitoring and Operation Support System, Addendum 4," September 2012.

SEQUOYAH – UNIT 1 B 3.2.1-13 Revision 45 Insert 3.2.1-A the elevation dependent measured planar radial peaking factors, FXY(Z), are increased by an elevation dependent factor, [T(Z)]COLR, that accounts for the expected maximum values of the transient axial power shapes postulated to occur during Relaxed Axial Offset Control (RAOC) operation (refer to TS 3.2.3 and TS 3.2.3 Bases). Thus, [T(Z)]COLR accounts for the worst case nonequilibrium power shapes that are expected for the assumed RAOC operating space. The RAOC operating space is defined as the combination of AFD and Control Bank Insertion Limits assumed in the calculation of a particular [T(Z)]COLR function. The [T(Z)]COLR factors are directly dependent on the AFD and Control Bank Insertion Limit assumptions. The COLR may contain different [T(Z)]COLR functions that reflect different operating space assumptions. If the limit on FQ(Z) is exceeded, a more restrictive operating space may be implemented to gain margin for future non-equilibrium operation.

Insert 3.2.1-B

The base FQ measurement uncertainty is defined by the PDMS when it is functional. When the PDMS is not functional and flux maps from the movable incore detectors are used to obtain core power distribution measurements, the base FQ measurement uncertainty defaults to 1.05 and C FQ (Z) is defined as,

C M FQ (Z) = FQ (Z) [1.0815] where 1.0815 is a factor that accounts for fuel manufacturing tolerances (the engineering uncertainty factor, 1.03) multiplied by a factor associated with the flux map uncertainty (1.05) as discussed in Reference 4. If the core power distribution measurement is obtained from a functional PDMS,

C M FQ (Z) = FQ (Z) (1.03)(1.00 + UQ/100) where 1.03 is the engineering uncertainty factor discussed above and UQ is a factor that accounts for the PDMS measurement uncertainty, determined as described in Reference 7. In order to be consistent with the LOCA analysis and the uncertainty inputs utilized, a minimum uncertainty of 5 percent should be used for UQ.

C FQ (Z) is an excellent approximation of FQ(Z) when the reactor is at the steady state power at which the core power distribution measurement was taken. If the core power distribution measurement is obtained from flux maps using the movable W incore detecors, the expression for FQ (Z) is:

W M COLR FQ (Z) = FXY (Z) [T(Z)] AXY(Z) Rj [1.0815] P The various factors in this expression are defined below:

M FXY (Z) is the measured radial peaking factor at axial location Z and is equal to the value of M M M FQ (Z) / P (Z), where P (Z) is the measured core average axial power shape.

[T(Z)]COLR is the cycle and burnup dependent function, specified in the COLR, which accounts for power distribution transients encountered during non-equilibrium normal operation. [T(Z)]COLR functions are specified for each analyzed RAOC operating space (i.e., each unique combination of AFD limits and Control Bank Insertion Limits). The [T(Z)]COLR functions account for the limiting non-equilibrium axial power shapes postulated to occur during normal operation for each RAOC operating space. Limiting power shapes at both full and reduced power operation are considered in determining the maximum values of [T(Z)]COLR. The [T(Z)]COLR functions also account for the following effects: (1) the presence of spacer grids in the fuel assembly, (2) the increase in radial peaking in rodded core planes due to the presence of control rods during non-equilibrium normal operation, (3) the increase in radial peaking that occurs during part-power operation due to reduced fuel and moderator temperatures, and (4) the increase in radial peaking due to non-equilibrium xenon effects. The [T(Z)]COLR functions are normally calculated assuming that the surveillance is performed at nominal RTP conditions with all shutdown and control rods withdrawn, i.e., all rods out (ARO). Surveillance-specific [T(Z)]COLR values may be generated for a given surveillance core condition.

P is the THERMAL POWER / RTP.

W AXY(Z) is a function that adjusts the FQ (Z) surveillance for differences between the reference core condition assumed in generating the [T(Z)]COLR function and the actual core condition that exists when the surveillance is performed. Normally, this reference core condition is 100% RTP, all rods out, and equilibrium xenon. For simplicity, AXY(Z) may be assumed to be 1.0, as this will W typically result in an accurate FQ (Z) surveillance result for a surveillance that is performed at or near the reference core condition, and an underestimation of the available margin to the FQ limit for surveillances that are performed at core conditions different from the reference condition. Alternatively, the AXY(Z) function may be calculated using the NRC approved methodology in Reference 6. 1.0815 is a factor that accounts for fuel manufacturing tolerances and measurement uncertainty.

Rj is a cycle and burnup dependent analytical factor specified in the COLR that accounts W for potential increases in FQ (Z) between surveillances. Rj values are provided for each RAOC operating space.

If the core power distribution measurement is obtained from a functional PDMS,

W M COLR FQ (Z) = FXY (Z) [T(Z)] AXY(Z) Rj [(1.03)(1 + UQ / 100)] P where the factors used in the equation are as defined previously. Insert 3.2.1-C

C Decrease in subsequent FQ (Z) measurements while in Condition A would allow increasing the maximum allowable power level and increasing power up to this revised limit.

C W If an FQ surveillance is performed at 100% RTP conditions, and both FQ (Z) and FQ (Z) exceed their limits (i.e., both Conditions A and B are entered), the option to reduce the THERMAL POWER limit in accordance with Required Action B.2.1 instead of implementing a new operating space in accordance with Required Action B.1.1, will result in a further power reduction after Required Action A.1 has been completed. However, this further power reduction would be permitted to occur over the next 4 hours. In the event the THERMAL POWER reduction in the COLR for Required Action B.2.1 did not result in a further power reduction (for example, if both Condition A and Condition B were entered at less than 100% RTP conditions), then the THERMAL POWER level established as a result of completing Required Action A.1 will take precedence, and will establish the effective operating power level limit for the unit until both Conditions A and B are exited.

Insert 3.2.1-D A reduction of the Power Range Neutron Flux - High trip setpoints E\•IRUHDFKWKDW THERMAL POWER is limited below RATED THERMAL POWER by Required Action A.1 is a conservative action for protection against the consequences of severe transients with unanalyzed power distributions. The Completion Time of 72 hours is sufficient considering the small likelihood of a severe transient in this time period and the preceding prompt reduction in THERMAL POWER in accordance with Required Action A.1. The maximum allowable Power Range Neutron Flux - High trip setpoints initially determined by Required Action A.2 may be C affected by subsequent determinations of FQ (Z) that are not within limit and could require Power Range Neutron Flux - High trip setpoint reductions within 72 hours of the subsequent C FQ (Z) determination, if necessary to comply with the decreased maximum allowable Power Range Neutron Flux - High trip setpoints. In short, the 72-hour Completion Time for Required C C Action A.2 applies after each FQ (Z) determination. Decreases in subsequent FQ (Z) measurements while in Condition A would allow increasing the maximum allowable Power Range Neutron Flux - High trip setpoints. Insert 3.2.1-E B.1.1

If it is found that the maximum calculated value of FQ(Z) that can occur during normal W C maneuvers, FQ (Z), exceeds its specified limits, there exists a potential for FQ (Z) to become excessively high if a normal operational transient occurs. Implementing a more restrictive RAOC operating space, as specified in the COLR, within the allowed Completion Time of 4 hours will restrict the AFD such that peaking factor limits will not be exceeded during non-equilibrium normal operation. Several RAOC operating spaces, representing successively smaller AFD envelopes and, optionally, shallower Control Bank Insertion Limits, may be specified in the COLR. The corresponding T(Z) functions for these operating spaces can be used to determine which RAOC operating space will result in acceptable non-equilibrium operation within the W FQ (Z) limit. B.1.2

If it is found that the maximum calculated value of FQ(Z) that can occur during normal W C maneuvers, FQ (Z), exceeds its specified limits, there exists a potential for FQ (Z) to become excessively high if a normal operational transient occurs. As discussed above, Required Action W B.1.1 requires that a new RAOC operating space be implemented to restore FQ (Z) to within its limits. Required Action B.1.2 requires that SR 3.2.1.1 and SR 3.2.1.2 be performed if control rod motion occurs as a result of implementing the new RAOC operating space in accordance with Required Action B.1.1. The performance of SR 3.2.1.1 and SR 3.2.1.2 is necessary to assure FQ(Z) is properly evaluated after any control rod motion resulting from the implementation of a new RAOC operating space in accordance with Required Action B.1.1. B.2.1

W When FQ (Z) exceeds its limit, Required Actions B.2.1 through B.2.4 may be implemented instead of Required Actions B.1.1 and B.1.2. Required Action B.2.1 limits THERMAL POWER to less than RATED THERMAL POWER by the amount specified in the COLR. It also requires reductions in the AFD limits by the amount specified in the COLR. This maintains an acceptable absolute power density relative to the maximum power density value assumed in the safety analyses.

W If the required FQ (Z) margin improvement exceeds the margin improvement available from the pre-analyzed THERMAL POWER and AFD reductions provided in the COLR, then THERMAL POWER must be further reduced to less than 50% RTP. In this case, reducing THERMAL POWER to less than 50% RTP will provide additional margin in the transient FQ by the required change in THERMAL POWER and the increase in the FQ limit. This will ensure that the FQ limit is met during transient operation that may occur below 50% RTP. The Completion Time of 4 hours provides an acceptable time to reduce the THERMAL POWER and AFD limits in an orderly manner to preclude entering an unacceptable condition during future non-equilibrium operation. The limit on THERMAL POWER initially determined by W Required Action B.2.1 may be affected by subsequent determinations of FQ (Z) that are not W within limit and could require power reductions within 4 hours of the subsequent FQ (Z) determination, if necessary to comply with the decreased THERMAL POWER limit. In short, the W 4-hour Completion Time for Required Action B.2.1 applies after each FQ (Z) W determination. Decreases in subsequent FQ (Z) measurements while in Condition B would allow increasing the THERMAL POWER limit and increasing THERMAL POWER up to this revised limit. Required Action B.2.1 is modified by a Note that states Required Action B.2.4 shall be completed whenever Required Action B.2.1 is performed prior to increasing THERMAL POWER above the limit of Required Action B.2.1. Required Action B.2.4 requires the performance of SR 3.2.1.1 and SR 3.2.1.2 prior to increasing THERMAL POWER above the limit established by Required Action B.2.1. The Note ensures that the SRs will be performed even if Condition B may be exited prior to performing Required Action B.2.4. The performance of SR 3.2.1.1 and SR 3.2.1.2 is necessary to assure FQ(Z) is properly evaluated prior to increasing THERMAL POWER.

C W If an FQ surveillance is performed at 100% RTP conditions, and both FQ (Z) and FQ (Z) exceed their limits (i.e., both Conditions A and B are entered), the option to reduce the THERMAL POWER limit in accordance with Required Action B.2.1 instead of implementing a new operating space in accordance with Required Action B.1.1, will result in a further power reduction after Required Action A.1 has been completed. However, this further power reduction would be permitted to occur over the next 4 hours. In the event the THERMAL POWER reduction in the COLR for Required Action B.2.1 did not result in a further power reduction (for example, if both Condition A and Condition B were entered at less than 100% RTP conditions), then the THERMAL POWER level established as a result of completing Required Action A.1 will take precedence, and will establish the effective operating power level limit for the unit until both Conditions A and B are exited. B.2.2

A reduction of the Power Range Neutron Flux-High trip setpoints by Ŏ 1% for each 1% by which the maximum allowable power is reduced is a conservative action for protection against the consequences of severe transients with unanalyzed power distributions. The Completion Time of 72 hours is sufficient considering the small likelihood of a severe transient in this time period and the preceding prompt reduction in the THERMAL POWER limit and AFD limits in accordance with Required Action B.2.1. The maximum allowable Power Range Neutron Flux - High trip setpoints initially determined by W Required Action B.2.2 may be affected by subsequent determinations of FQ (Z) that are not within limit and could require Power Range Neutron Flux - High trip setpoint reductions within 72 W hours of the subsequent FQ (Z) determination, if necessary to comply with the decreased maximum allowable Power Range Neutron Flux - High trip setpoints. In short, the 72-hour W Completion Time for Required Action B.2.2 applies after each FQ (Z) determination. Decreases W in subsequent FQ (Z) measurements while in Condition B would allow increasing the maximum allowable Power Range Neutron Flux - High trip setpoints. B.2.3

5HGXFWLRQLQWKH2YHUSRZHU¨7WULSVHWSRLQWVE\Ŏ 1% for each 1% by which the maximum allowable power is reduced is a conservative action for protection against the consequences of severe transients with unanalyzed power distributions. The Completion Time of 72 hours is sufficient considering the small likelihood of a severe transient in this time period, and the preceding prompt reduction in the THERMAL POWER limit and AFD limits in accordance with Required Action B.2.1. The maximXPDOORZDEOH2YHUSRZHU¨7WULSVHWSRLQWVLQLWLDOO\GHWHUPLQHGE\5HTXLUHG$FWLRQ W B.2.3 may be affected by subsequent determinations of FQ (Z) that are not within limit and W FRXOGUHTXLUH2YHUSRZHU¨7WULSVHWSRLQWUHGXFWLRQVZLWKLQKRXUVRIWKHVXEVHTXHQt FQ (Z) GHWHUPLQDWLRQLIQHFHVVDU\WRFRPSO\ZLWKWKHGHFUHDVHGPD[LPXPDOORZDEOH2YHUSRZHU¨7 trip setpoints. In short, the 72-hour Completion Time for Required Action B.2.3 applies after W W each FQ (Z) determination. Decreases in subsequent FQ (Z) measurements while in Condition %ZRXOGDOORZLQFUHDVLQJWKHPD[LPXPDOORZDEOH2YHUSRZHU¨7WULSVHWSRLQWV B.2.4

W Verification that FQ (Z) has been restored to within its limit, by performing SR 3.2.1.1 and SR 3.2.1.2 prior to increasing THERMAL POWER above the maximum allowable power limit imposed by Required Action B.2.1, ensures that core conditions during operation at higher power levels and future operation are consistent with safety analyses assumptions. Insert 3.2.1-F The allowance of up to 24 hours after achieving equilibrium conditions at the increased C THERMAL POWER level to complete the next FQ (Z) surveillance applies to situations where C the FQ (Z) has already been measured at least once at a reduced THERMAL POWER level. The observed margin in the previous surveillance will provide assurance that increasing power up to the next plateau will not exceed the FQ limit, and that the core is behaving as designed. This Frequency condition is not intended to require verification of these parameters after every 10% increase in RTP above the THERMAL POWER at which the last verification was performed. It only requires verification after a THERMAL POWER is achieved for extended C operation that is 10% higher than the THERMAL POWER at which FQ (Z) was last measured. The nominal (non-conditional) Surveillance Frequency is adequate to monitor the change of core power distribution with core burnup and is controlled under the Surveillance Frequency Control Program. Insert 3.2.1-G

The measured FQ(Z) can be determined through a synthesis of the measured planar radial M M peaking factors, FXY (Z), and the measured core average axial power shape, P (Z). Thus, C FQ (Z) is given by the following expression:

C M M M FQ (Z) = FXY (Z) P (Z) [1.0815] = FQ (Z) [1.0815] (incore flux maps)

C M M M FQ (Z) = FXY (Z) P (Z) [(1.03)(1.00 + UQ/100)] = FQ (Z) [(1.03)(1.00 + UQ/100)] (with a functional PDMS) For RAOC operation, the analytical [T(Z)]COLR functions, specified in the COLR for each RAOC operating space, are used together with the measured FXY(Z) values to estimate FQ(Z) for non- equilibrium operation within the RAOC operating space. When the FXY(Z) values are measured W at HFP ARO conditions (AXY(Z) equals 1.0), FQ (Z) is given by the following expression:

W M COLR FQ (Z) = FXY (Z) [T(Z)] Rj [1.0815] (incore flux maps)

W M COLR FQ (Z) = FXY (Z) [T(Z)] Rj [(1.03)(1.00 + UQ/100)] (with a functional PDMS) Non-equilibrium operation can result in significant changes to the axial power shape. To a lesser extent, non-equilibrium operation can increase the radial peaking factors, FXY(Z), through control rod insertion and through reduced Doppler and moderator feedback at part-power conditions. The [T(Z)]COLR functions quantify these effects for the range of power shapes, control rod insertion, and power levels characteristic of the operating space. Multiplying [T(Z)]COLR by the M measured full power, unrodded FXY (Z) value, and the factors that account for manufacturing W and measurement uncertainties gives FQ (Z), the maximum total peaking factor postulated for non-equilibrium RAOC operation.

W The limit with which FQ (Z) is compared varies inversely with power above 50% RTP and directly with the function K(Z) provided in the COLR.

Insert 3.2.1-H The excluded regions at the top and bottom of the core are specified in the COLR and are defined to ensure that the minimum margin location is adequately surveilled. A smaller exclusion zone may be specified, if necessary, to include the limiting margin location in the surveilled region of the core.

W SR 3.2.1.2 requires a surveillance of FQ (Z) during the initial startup following each refueling within 24 hours after exceeding 75% RTP. THERMAL POWER levels below 75% RTP are W typically non-limiting with respect to the limit for FQ (Z). Furthermore, startup physics testing also performed at low power, provide confirmation that the core is operating as expected. This W Frequency ensures that verification of FQ (Z) is performed prior to extended operation at power levels where the maximum permitted peak linear heat rate could be challenged and that the first required performance of SR 3.2.1.2 after a refueling is performed at a power level high enough to provide a high level of confidence in the accuracy of the surveillance result. Equilibrium conditions are achieved when the core is sufficiently stable at the intended operating conditions required to perform the surveillance.

W If a previous surveillance of FQ (Z) was performed at part power conditions, SR 3.2.1.2 also W requires that FQ (Z) be verified at power levels >10 RTP above the THERMAL POWER of its W last verification within 24 hours after achieving equilibrium conditions. This ensures that FQ (Z) is within its limit using radial peaking factors measured at the higher power level. The allowance of up to 24 hours after achieving equilibrium conditions will provide a more W accurate measurement of FQ (Z) by allowing sufficient time to achieve equilibrium conditions and obtain the power distribution measurement. N F (X,Y) F ȜH ǻ+ B 3.2.2 N F ȜH B 3.2 POWER DISTRIBUTION LIMITS

B 3.2.2 Nuclear Enthalpy Rise Hot Channel Factor (Fǻ+(X,Y))

BASES

BACKGROUND The purpose of this LCO is to establish limits on the power density at any point in the core so that the fuel design criteria are not exceeded and the accident analysis assumptions remain valid. The design limits on local (pellet) and integrated fuel rod peak power density are expressed in terms of hot channel factors. Control of the core power distribution with respect to these factors ensures that local conditions in the fuel rods and coolant channels do not challenge core integrity at any location during either normal operation or a postulated accident analyzed in the safety analyses. N F ȜH Fǻ+(X,Y) is defined as the ratio of the integral of the linear power along the fuel rod with the highest integrated power to the average integrated fuel rod power. Therefore, Fǻ+(X,Y) is a measure of the maximum total power produced in a fuel rod. N F ȜH N F ȜH Fǻ+(X,Y) is sensitive to fuel loading patterns, bank insertion, and fuel burnup. Fǻ+(X,Y) typically increases with control bank insertion and typically decreases with fuel burnup. N or a functional PDMS N F H F ȜH Ȝ measurement Fǻ+(X,Y) is not directly measurable but is inferred from a power distribution map obtained with the movable incore detector system. measurement Specifically, the results of the three dimensional power distribution map are analyzed by a computer to determine Fǻ+(X,Y). An Fǻ+(X,Y) evaluation requires obtaining an incore flux map in MODE 1. The incore M flux map results provide the measured value ( 'H )Y,X(F ) of Fǻ+(X,Y) for each assembly location (X,Y). The Fǻ+ ratio (FDHR) is used in order to determine the Fǻ+ limit for the measured and design power distributions (Ref. 4). Then, M M 'H )Y,X(F N )ǻ+5 (X,Y) = F ȜH. MAPM / AXIALM )Y,X( where MAPM is the maximum allowable peak from the COLR for the measured assembly power distribution at assembly location (X,Y) which accounts for calculational and measurement uncertainties, and AXIALM )Y,X( is the measured ratio of the peak-to-average axial power at assembly location (X,Y).

BHDES(X,Y) is a cycle dependent design limit to preserve Departure from Nucleate Boiling(DNB) assumed for initial conditions at the time of limiting transients such as a Loss of Flow Accident (LOFA). BRDES(X,Y) is a

SEQUOYAH – UNIT 1 B 3.2.2-1 Revision 45

N F ȜH Fǻ+(X,Y) B 3.2.2

BASES

BACKGROUND (continued)

cycle dependent design limit to preserve reactor protection system safety limits for DNB requirements (Ref. 4).

The expression for BHDES(X,Y) is:

BHDES(X,Y) = )ǻ+5d(X,Y) * MH(X,Y)

d )Y,X(F where: )ǻ+5d(X,Y) = 'H MAPd / AXIALd )Y,X( x MAPd is the maximum allowable peak from the COLR for the design assembly power distribution at assembly location (X,Y) which accounts for calculational and measurement uncertainties,

x AXIALd )Y,X( is the design ratio of the peak-to-average axial power at assembly location (X,Y),

d x 'H )Y,X(F is the design Fǻ+ assembly location (X, Y), and

x MH(X,Y) is the minimum available margin ratio for initial condition DNB at the limiting conditions at assembly location (X,Y).

The expression for BRDES(X,Y) is:

BRDES(X,Y) = )ǻ+5d(X,Y) * MHs(X,Y)

where: MHs(X,Y) is the minimum available margin ratio for steady state DNB at the limiting conditions at assembly location (X,Y).

7KHUHDFWRUFRUHLVƎRSHUDWLQJDVGHVLJQHGƎLIWKHPHDVXUHGVWHDG\VWDWH core power distribution agrees with prediction within statistical variation. This guarantees that the operating limits will preserve the thermal criteria LQWKHDSSOLFDEOHVDIHW\DQDO\VHV7KHFRUHLVƎRSHUDWLQJDVGHVLJQHGƎLI the following relationship is satisfied: measured periodically )ǻ+5M(X,Y) ”%+120 ;< during power operation.

where: BHNOM(X,Y) is the nominal design radial peaking factor for an assembly at core location (X,Y) increased by an allowance for the expected deviation between the measured and predicted design power distribution. This factor is calculated at least every 31 EFPD. However, during power operation, the global power distribution is monitored by LCO 3.2.3, "AXIAL FLUX DIFFERENCE (AFD)," and LCO 3.2.4, "QUADRANT POWER TILT RATIO (QPTR)," which address directly and continuously measured process variables.

SEQUOYAH – UNIT 1 B 3.2.2-2 Revision 45

Compliance with these LCOs, along with the LCOs governing shutdown and control rod insertion and alignment, maintains the core limits on power distribution on a continuous basis. N F ȜH FǻH(X,Y) B 3.2.2

BASES

BACKGROUND (continued) departure from nucleate boiling ratio

The COLR provides peaking factor limits that ensure that the design basis value of the DNB is met for normal operation, operational transients, and any transient condition arising from events of moderate frequency. The DNB design basis precludes DNB and is met by limiting the minimum local DNB heat flux ratio to the design limit value using an NRC approved critical heat flux correlation. All DNB limited transient events are assumed to begin with an FǻH(X,Y) value that satisfies the LCO requirements. N F ȜH Operation outside the LCO limits may produce unacceptable consequences if a DNB limiting event occurs. The DNB design basis ensures that there is no overheating of the fuel that results in possible N cladding perforation with the release of fission products to the reactor F ȜH coolant.

APPLICABLE Limits on FǻH(X,Y) preclude core power distributions that exceed the SAFETY following fuel design limits: ANALYSES a. There must be at least 95% probability at the 95% confidence level For Condition II events, (the 95/95 DNB criterion) that the hottest fuel rod in the core does not there experience a DNB condition, b. During a large break loss of coolant accident (LOCA), peak cladding the 10 CFR 50.46 temperature (PCT) must not exceed 2200°F, acceptance criteria must be met (Ref. 3), c. During an ejected rod accident, the energy deposition to the fuel must not exceed 280 cal/gm (Ref. 1), and the average fuel pellet 200 enthalpy at the hot spot d. Fuel design limits required by GDC 26 (Ref. 2) for the condition when control rods must be capable of shutting down the reactor with a minimum required SDM with the highest worth control rod stuck fully withdrawn. N F ȜH For transients that may be DNB limited, the Reactor Coolant System flow and FǻH(X,Y) are the core parameters of most importance. The limits on N FǻH(X,Y) ensure that the DNB design basis is met for normal operation, F H Ȝ operational transients, and any transients arising from events of moderate frequency. The DNB design basis is met by limiting the minimum local DNBR to the 95/95 DNB DNB heat flux ratio to the design limit value using an NRC approved criterion applicable to a critical heat flux correlation. This value provides a high degree of specific DNBR correlation. assurance that the hottest fuel rod in the core does not experience a DNB. condition. N F ȜH limit increases

The allowable FǻH(X,Y), FǻH min margin and f1(¨I) min margin, increase with decreasing power level. This functionality in FǻH(X,Y) is

N SEQUOYAH – UNIT 1 B 3.2.2-3 F ȜH Revision 49 N F ȜH FǻH(X,Y) B 3.2.2

BASES

APPLICABLE SAFETY ANALYSES (continued)

included in the analyses that provide the Reactor Core Safety Limits (SLs) of SL 2.1.1. Therefore, any DNB events in which the calculation of the core limits is modeled implicitly use this variable value of FǻH(X,Y) in N the analyses. Likewise, all transients that may be DNB limited are F ȜH N an initial F ȜH as a assumed to begin with FǻH min margin and f1 (¨I) min margin. N function of power level also uses F ȜH defined by the COLR The LOCA safety analysis indirectly models FǻH(X,Y) as an input limit equation. parameter. The Nuclear Heat Flux Hot Channel Factor (FQ(X,Y,Z)) and the axial peaking factors are inserted directly into the LOCA safety analyses that verify the acceptability of the resulting peak cladding compliance with the 10 temperature (Ref. 3). supported by CFR 50.46 acceptance criteria The fuel is protected in part by Technical Specifications, which ensure that the initial conditions assumed in the safety and accident analyses remain valid. The following LCOs ensure this: LCO 3.2.3, "AXIAL FLUX DIFFERENCE (AFD)," LCO 3.2.4, "QUADRANT POWER TILT RATIO (QPTR)," LCO 3.1.6, "Control Bank Insertion Limits," LCO 3.2.2, "Nuclear Enthalpy Rise Hot Channel Factor FǻH(X,Y)," and LCO 3.2.1, "Heat Flux Hot Channel Factor (FQ(X,Y,Z))." N F H Ȝ N F ȜH FǻH(X,Y) and FQ(X,Y,Z) are indirectly measured periodically using the movable incore detector system. Measurements are generally taken with the core at, or near, steady state conditions. Core monitoring and control under transient conditions (Condition 1 events) are accomplished by equilibrium operating the core within the limits of the LCOs on AFD, QPTR, and Bank Insertion Limits. or a functional PDMS.

N F ȜH FǻH(X,Y) satisfies Criterion 2 of 10 CFR 50.36(c)(2)(ii).

LCO The LCO states that FǻH(X,Y) shall be less than the limits provided in the COLR. This LCO relationship must be satisfied even if the core is operating at limiting conditions. This requires adjustment to the Note: add Insert 3.2.2-A. measured FǻH(X,Y) to account for limiting conditions and the differences between design and measured conditions. The adjustments are accounted for by comparing FǻHRM(X,Y) to the limits BHDES(X,Y) and BRDES(X,Y). Therefore, if the FǻH min margin is • 0 and f1(¨I) min N F ȜH margin • 0 the LCO is satisfied.

APPLICABILITY The FǻH(X,Y) limits must be maintained in MODE 1 to preclude core power distributions from exceeding the fuel design limits for DNBR and PCT. Applicability in other modes is not required because there is either insufficient stored energy in the fuel or insufficient energy being transferred to the coolant to require a limit on the distribution of core power. Specifically, the design bases events that are sensitive to

SEQUOYAH – UNIT 1 B 3.2.2-4 Revision 49

N F ȜH FǻH(X,Y) B 3.2.2

BASES

APPLICABLITY (continued) N F ȜH FǻH(X,Y) in other modes (MODES 2 through 5) have significant margin to DNB, and therefore, there is no need to restrict FǻH(X,Y) in these modes.

M ACTIONS The % FǻH margin is based on the relationship between F¨HR (X,Y) and the limit, BHDES (X,Y), as follows: N F H Ȝ § F' HRM (X,Y) · % F 'H Margin = ¨1  ¸ x 100% © BHDES(X,Y) ¹

M If the reactor core is Ǝoperating as designedƎ, then F¨HR (X,Y) is less than BHDES (X,Y) and calculation of %FǻH margin is not required. If the M %FǻH margin is less than zero, then F¨HR (X,Y) is greater than BHDES (X, Y) and the FǻH(X,Y) limits may not be adequate to prevent exceeding the initial DNB conditions assumed for transients such as a LOFA. BHDES (X,Y) represents the maximum allowable design radial peaking factors which ensures that the initial condition DNB will be preserved for operation within the LCO limits, and includes allowances for calculational and measurement uncertainties. The FǻH min margin is the minimum for all core locations examined.

Condition A is modified by a Note that requires that Required Actions A.3 and A.5 must be completed whenever Condition A is entered. If FǻH min margin < 0 is restored to within limits prior to completion of the THERMAL Note: add Insert 3.2.2-B. POWER reduction in Required Action A.1, compliance with Required Actions A.3 and A.5 must be met.

However, if power is reduced below 50% RTP, Required Action A.5 requires that another determination of FǻH min margin must be verified prior to exceeding 50% RTP, prior to exceeding 75% RTP, and within 24 hours after reaching or exceeding 95% RTP.

A.1 and A.2

If the value of FǻH min margin is not restored to within its specified limit either by adjusting a misaligned rod or by reducing THERMAL POWER, the alternative option is to reduce allowable THERMAL POWER from RTP by at least RRH% (where RRH = Thermal power reduction required to compensate for each 1% that FǻH(X,Y) exceeds its limit) multiplied by the F¨H min margin in accordance with Required Action A.1 and reduce the Power Range Neutron Flux - High trip setpoints, as specified in TS Table 3.3.1-1 by • RRH% multiplied times the F¨H min margin in accordance with Required Action A.2. Reducing allowable RTP by at least RRH% multiplied by the FǻH min margin increases the DNB

SEQUOYAH – UNIT 1 B 3.2.2-5 Revision 49

N F ȜH FǻH(X,Y) B 3.2.2

BASES

ACTIONS (continued)

margin and does not likely cause the DNBR limit to be violated in steady state operation. The reduction in trip setpoints ensures that continuing operation remains at an acceptable low power level with adequate DNBR margin. The allowed Completion Time of 2 hours for Required Action A.1 provides an acceptable time to reach the required power level from full power operation without allowing the plant to remain in an unacceptable condition for an extended period of time.

The allowed Completion Time of 72 hours to reset the trip setpoints per Required Action A.2 recognizes that, once power is reduced, the safety analysis assumptions are satisfied and there is no urgent need to reduce the trip setpoints. This is a sensitive operation that may inadvertently trip the Reactor Protection System.

A.3

Once the allowable power level has been reduced by at least RRH% multiplied by the F¨H min margin per Required Action A.1, an incore flux map (SR 3.2.2.1) must be obtained and the F¨H min margin is verified • 0 at the lower power level. The unit is provided 22 additional hours to perform this task over and above the 2 hours allowed by Action A.1. The Completion Time of 24 hours is acceptable because of the increase in the DNB margin, which is obtained at lower power levels, and the low probability of having a DNB limiting event within this 24 hour period. Additionally, operating experience has indicated that this Completion Time is sufficient to obtain the incore flux map, perform the required calculations, and evaluate F¨H min margin.

A.4

If the value of F¨HRM(X,Y) is not restored to within its specified limit, Overtemperature ǻT K1 (OTǻT K1) term is required to be reduced by at least TRH multiplied by the F¨H min margin. The value of TRH is provided in the COLR. Completing Required Action A.4 ensures protection against the consequences of transients since this adjustment limits the peak transient power level which can be achieved during an anticipated operational occurrence. Also, completing Required Action A.4 within the allowed Completion Time of 48 hours is sufficient considering the small likelihood of a limiting transient in this time period.

SEQUOYAH – UNIT 1 B 3.2.2-6 Revision 49

N F ȜH Fǻ+(X,Y) B 3.2.2

BASES

ACTIONS (continued)

A.5

Verification that F¨H min margin is • 0 after an out of limit occurrence ensures that the cause that led to the F¨H min margin exceeding its limit is corrected, and that subsequent operation proceeds within the LCO limit. This Action demonstrates that the F¨H min margin limit is • 0 prior to exceeding 50% RTP, again prior to exceeding 75% RTP, and within 24 KRXUVDIWHU7+(50$/32:(5LV• 95% RTP.

This Required Action is modified by a Note that states that THERMAL POWER does not have to be reduced prior to performing this Action.

B.1

M The %f1 ¨, margin is based on the relationship between )¨+5 (X,Y) and the limit, BRDES (X,Y), as follows:

§ F' HR M (X,Y)· % f (' I)Margin = ¨ 1  ¸ x 100% 1 © BRDES(X,Y) ¹

If WKHUHDFWRUFRUHLVƎRSHUDWLQJDVGHVLJQHGƎWKHQ)¨+5M(X,Y) is less than BRDES (X,Y) and calculation of %f1 ¨, margin is not required. If M the %f1 ¨, margin is less than zero, then )¨+5 (X,Y) is greater than BRDES (X, Y) and the 27¨7 setpoint limits may not be adequate to prevent exceeding DNB requirements.

BRDES (X,Y) represents the maximum allowable design radial peaking factors which ensure that the steady state DNBR limit will be preserved for operation within the LCO limits, including allowances for calculational and measurement uncertainties.

Required Action B.1 requires the reduction of the 27¨7.WHUPE\DW least TRH multiplied by the f1 ¨, PLQPDUJLQ TRH is the amount of OTǻ7 K1 setpoint reduction required to compensate for each 1% that F¨H(X,Y) exceeds the limit provided in the COLR. Completing Required Action B.1 within the allowed Completion Time of 48 hours, restricts Fǻ+(X,Y) such that even if a transient occurred, DNB requirements are met. The f1 ¨, PLQPDUJLQLVWKHPLQLPXPRII1 ¨, PDUJLQIRUDOOFRUH locations examined.

SEQUOYAH – UNIT 1 B 3.2.2-7 Revision 45 N F ȜH Fǻ+(X,Y) B 3.2.2

BASES

ACTIONS (continued)

C.1

When Required Actions A.1 through A.5, and B.1, cannot be completed within their required Completion Times, the plant must be placed in a mode in which the LCO requirements are not applicable. This is done by placing the plant in at least MODE 2 within 6 hours. The allowed Completion Time of 6 hours is reasonable, based on operating experience regarding the time required to reach MODE 2 from full power conditions in an orderly manner and without challenging plant systems.

SURVEILLANCE SR 3.2.2.1 and SR 3.2.2.2 are modified by a Note. It states that, "Not REQUIREMENTS required to be performed until 12 hours after an equilibrium power level has been achieved at which a power distribution map can be obtained." SR 3.2.2.1 and SR 3.2.2.2 require using the incore detector system to provide the necessary data to create a power distribution map. To provide the necessary data, MODE 1 needs to be entered, power escalated, stabilized and equilibrium conditions established at some higher power level. These surveillances could not be satisfactorily performed if the requirement for performance of the Surveillances was included in MODE 2 prior to entering MODE 1.

M In a reload core, F ¨+(X,Y) could not have previously been measured, therefore, there is a Frequency condition, applicable only for reload cores, that requires determination of these parameters before exceeding M 75% RTP. This ensures that some determination of F ¨+(X,Y) is made at a lower power level at which adequate margin is available before going to Note: add Insert 3.2.2-C. 100% RTP.

SR 3.2.2.1 and SR 3.2.2.2

In addition to ensuring via Surveillance that the nuclear enthalpy rise hot channel factor is within its limits when a measurement is taken, there are M also requirements to extrapolate trends in F ¨+(X,Y) for the last two measurements out to 31 EFPD beyond the most recent measurement. If WKHH[WUDSRODWLRQ\LHOGVDQ)¨+5M(X,Y) > BHNOM(X,Y), further consideration is required.

The implications of these extrapolations are considered separately for M BHDES(X,Y) and BRDES(X,Y) limits. If the extrapolations of F ¨+(X,Y) are unfavorable, additional actions must be taken. These actions are to meet M the Fǻ+(X,Y) limit with the last F ¨+(X,Y) increased by the appropriate M factor specified in the COLR or to evaluate F ¨+(X,Y) prior to the projected

SEQUOYAH – UNIT 1 B 3.2.2-8 Revision 45

N F ȜH Fǻ+(X,Y) B 3.2.2

BASES

SURVEILLANCE REQUIREMENTS (continued)

point in time when the extrapolated values are expected to exceed the extrapolated limits. These alternative requirements attempt to prevent Fǻ+(X,Y) from exceeding its limit for any significant period of time without detection using the best available data.

Extrapolation is not required for the initial flux map taken after reaching equilibrium conditions following a refueling outage since the initial flux map establishes the baseline measurement for future trending.

The Surveillance Frequency is controlled under the Surveillance Frequency Control Program. WCAP-18459-P, REFERENCES 1. Regulatory Guide 1.77, Rev. 0, May 1974. Revision 1, “Sequoyah Units 1 and 2 Reload 2. 10 CFR 50, Appendix A, GDC 26. Transition Safety Report

3. 10 CFR 50.46. with RFA-2 Fuel,” June 2020. 4. BAW-10163P-A, Revision 0, “Core Operating Limit Methodology for Westinghouse-Designed PWRs,” June 1989.

WCAP-12472-P-A, "BEACON Core Monitoring and Operations Support System," August 1994; and WCAP-12472-P-A, Addendum 4, "BEACONTM Core Monitoring and Operation Support System, Addendum 4," September 2012.

SEQUOYAH – UNIT 1 B 3.2.2-9 Revision 45

Insert 3.2.2-A

N F ǻ+ shall be maintained within the limits of the relationship provided in the COLR.

N The F ǻ+ limit is representative of the coolant flow channel with the maximum enthalpy rise. This channel has the least removal capability and thus the highest probability for a DNB condition.

N The limiting value of F ǻ+ described by the equation contained in the COLR, is the design radial peaking factor used in the unit safety analyses. A power multiplication factor in this equation includes an additional allowance for higher radial peaking factors from reduced thermal feedback and greater control rod insertion at low power N levels. The limiting value of F ǻ+ is allowed to increase by a cycle-dependent factor (PFǻ+, as specified in the COLR) for each 1% RTP reduction in THERMAL POWER.

Insert 3.2.2-B A.1.1

N N With F ǻ+ exceeding its limit, the unit is allowed 4 hours to restore F ǻ+ to within its limits. This restoration may, for example, involve realigning any misaligned rods or reducing power enough N N to bring F ǻ+ within its power dependent limit. When the F ǻ+ limit is exceeded, the DNBR limit is not likely violated in steady state operation, because events that could significantly perturb the N F ǻ+ value (e.g., static control rod misalignment) are considered in the safety analyses. However, the DNBR limit may be violated if a DNB limiting event occurs. Thus, the allowed N Completion Time of 4 hours provides an acceptable time to restore F ǻ+ to within its limits without allowing the plant to remain in an unacceptable condition for an extended period of time.

Condition A is modified by a Note that requires that Required Actions A.2 and A.3 must be completed whenever Condition A is entered. Thus, even if this Required Action is completed within the 4 hour time period, Required Action A.2 requires another measurement and N calculation of F ǻ+ within 24 hours in accordance with SR 3.2.2.1.

N Required Action A.3 requires that another determination of F ǻ+ must be done prior to exceeding 50% RTP, prior to exceeding 75% RTP, and within 24 hours after reaching or exceeding 95% RTP; however, THERMAL POWER does not have to be reduced to comply with these requirements. In addition, Required Action A.2 is performed if power ascension is delayed past 24 hours. A.1.2.1 and A.1.2.2

N If the value of F ǻ+ is not restored to within its specified limit either by adjusting a misaligned rod or by reducing THERMAL POWER, the alternative option is to reduce THERMAL POWER to < 50% RTP in accordance with Required Action A.1.2.1 and reduce the Power Range Neutron Flux-High trip setpoints to ”55% RTP in accordance with Required Action A.1.2.2. Reducing power to < 50% RTP increases the DNB margin and does not likely cause the DNBR limit to be violated in steady state operation. The reduction in trip setpoints ensures that continuing operation remains at an acceptable low power level with adequate DNBR margin. The allowed Completion Time of 4 hours for Required Action A.1.2.1 is consistent with that allowed for in Required Action A.1.1 and provides an acceptable time to reach the required power level from full power operation without allowing the plant to remain in an unacceptable condition for an extended period of time. The Completion Times of 4 hours for Required Actions A.1.1 and A.1.2.1 are not additive.

The allowed Completion Time of 72 hours to reset the trip setpoints per Required Action A.1.2.2 recognizes that, once power is reduced, the safety analysis assumptions are satisfied and there is no urgent need to reduce the trip setpoints; however, for extended operations at the reduced power level, the reduced trip setpoints are required to protect against events involving positive reactivity excursions. This is a sensitive operation that may inadvertently trip the reactor. A.2

N Once actions have been taken to restore F ǻ+ to within its limits per Required Action A.1.1, or the power level has been reduced to < 50% RTP per Required Action A.1.2.1, a core power N distribution measurement (SR 3.2.2.1) must be obtained and the measured value of F ǻ+ verified not to exceed the allowed limit at the lower power level. The unit is provided 20 additional hours to perform this task over and above the 4 hours allowed by either Action A.1.1 or Action A.1.2.1. The Completion Time of 24 hours is acceptable because of the increase in the DNB margin, which is obtained at lower power levels, and the low probability of having a DNB limiting event within this 24 hour period.

Additionally, operating experience has indicated that this Completion Time is sufficient to obtain N the core power distribution measurement, perform the required calculations, and evaluate F ǻ+.

A.3

N Verification that F ǻ+ is within its specified limits after an out of limit occurrence ensures that the N cause that led to the F ǻ+ exceeding its limit is identified, to the extent necessary, and corrected, and that subsequent operation proceeds within the LCO limit. This Action demonstrates that the N F ǻ+ limit is within the LCO limits prior to exceeding 50% RTP, again prior to exceeding 75% RTP, and within 24 hours after THERMAL POWER is •95% RTP.

This Required Action is modified by a Note that states that THERMAL POWER does not have to be reduced to comply with this Required Action prior to performing this Action.

B.1

When Required Actions A.1.1 through A.3 cannot be completed within their required Completion Times, the plant must be placed in a mode in which the LCO requirements are not applicable. This is done by placing the plant in MODE 2 within 6 hours. The allowed Completion Time of 6 hours is reasonable, based on operating experience regarding the time required to reach MODE 2 from full power conditions in an orderly manner and without challenging plant systems. Insert 3.2.2-C SR 3.2.2.1

N The value of F ǻ+ is determined by using the movable incore detector system or a functional PDMS to obtain a power distribution measurement. A data reduction computer program then N calculates the maximum value of F ǻ+ from the measured flux distributions. If the PDMS is used, the appropriate measurement uncertainty is automatically calculated and applied to the N measured F ǻ+ (Ref. 4). ,QRUGHUWREHFRQVLVWHQWZLWKWKH/2&$DQDO\VLVDPLQLPXP 1 XQFHUWDLQW\RISHUFHQWVKRXOGEHXVHGIRU) ǻ+

N If the movable incore detector system is used the measured value of F ǻ+ must be multiplied by N 1.04 to account for measurement uncertainty before making comparisons to the F ǻ+ limit.

N After each refueling, F ǻ+ must be determined in MODE 1 prior to exceeding 75% RTP. This N requirement ensures that F ǻ+ limits are met at the beginning of each fuel cycle. Performing this Surveillance in MODE 1 prior to exceeding 75% RTP, or at a reduced power level at any other N N time, and meeting the 100% RTP F ǻ+ limit, provides assurance that the F ǻ+ limit is met when RTP is achieved, because peaking factors generally decrease as power level is increased.

After the initial surveillance performance, the non-Conditional Surveillance Frequency is controlled under the Surveillance Frequency Control Program. AFD B 3.2.3

B 3.2 POWER DISTRIBUTION LIMITS

B 3.2.3 AXIAL FLUX DIFFERENCE (AFD)

BASES

BACKGROUND The purpose of this LCO is to establish limits on the values of the AFD in order to limit the amount of axial power distribution skewing to either the top or bottom of the core. By limiting the amount of power distribution skewing, core peaking factors are consistent with the assumptions used in the safety analyses. Limiting power distribution skewing over time also minimizes the xenon distribution skewing, which is a significant factor in axial power distribution control. Note: add Insert 3.2.3-A. The AFD limits are selected by considering a range of axial xenon distributions that may occur as a result of large variations of the AFD. Subsequently, power peaking factors and power distributions are examined to ensure that the loss of coolant accident (LOCA), loss of flow accident, and anticipated transient limits are met. Violation of the AFD limits invalidate the conclusions of the accident and transient analyses with regard to fuel cladding integrity.

The AFD is monitored on an automatic basis using the unit process computer, which has an AFD monitor alarm. The computer determines the 1 minute average of each of the OPERABLE excore detector outputs Note: add Insert 3.2.3-B. and provides an alarm message immediately if the AFD for two or more OPERABLE excore channels is outside its specified limits.

APPLICABLE The AFD is a measure of the axial power distribution skewing to either the SAFETY top or bottom half of the core. The AFD is sensitive to many core related ANALYSES parameters such as control bank positions, core power level, axial burnup, axial xenon distribution, and, to a lesser extent, reactor coolant temperature and boron concentration.

The allowed range of the AFD is used in the nuclear design process to confirm that operation within these limits produces core peaking factors and axial power distributions that meet safety analysis requirements (Ref.1). Note: add Insert 3.2.3-C. The limits on the AFD ensure that the Heat Flux Hot Channel Factor (FQ(X,Y,Z)) is not exceeded during either normal operation or in the event of xenon redistribution following power changes. The limits on the AFD II, III, or IV also restrict the range of power distributions that are used as initial conditions in the analyses of Condition 2, 3, or 4 events. A Condition 4 IV III event significantly affected by the initial axial power distribution, as indicated by AFD, is the LOCA. A Condition 3 event significantly affected by AFD is the Complete Loss of RCS Flow event. Compliance with these limits ensures that acceptable levels of fuel cladding integrity is maintained, or cladding damage is limited within acceptance criteria, for these postulated accidents.

SEQUOYAH – UNIT 1 B 3.2.3-1 Revision 45 AFD B 3.2.3

Ref. 1 BASES

APPLICABLE SAFETY ANALYSES (continued)

A Condition 2 event significantly affected by AFD is the Uncontrolled RCCA Bank Withdrawal at Power Event (Ref. 2). Condition 2 accidents, simulated to begin from within the AFD limits are used to confirm the adequacy of the Overpower ¨T and Overtemperature ¨T trip setpoints.

The limits on the AFD satisfy Criterion 2 of 10 CFR 50.36(c)(2)(ii).

LCO The shape of the power profile in the axial (i.e., the vertical) direction is largely under the control of the operator through the manual operation of the control banks or automatic motion of control banks. The automatic motion of the control banks is in response to temperature deviations resulting from manual operation of the Chemical and Volume Control System to change boron concentration or from power level changes. Ref. 2 Signals are available to the operator from the Nuclear Instrumentation System (NIS) excore neutron detectors (Refs. 1 and 3). Separate signals The AFD limits for are taken from the top and bottom detectors. The AFD is defined as the RAOC do not depend difference in normalized flux signals between the top and bottom excore on the target flux detectors in each detector well. For convenience, this flux difference is converted to provide flux difference units expressed as a percentage and difference. However, labeled as %¨ flux or %¨I. the target flux difference may be used The AFD limits are provided in the COLR. The AFD limits resulting from to minimize changes in analysis of core power distributions relative to the initial condition peaking the axial power limits comprise a power-dependent envelope of acceptable AFD values. distribution. During steady-state operation, the core normally is controlled to a target AFD within a narrow (approximately ± 5% AFD) band. However, the limiting AFD values may be somewhat greater than the extremes of the normal operating band.

Violating this LCO on the AFD could produce unacceptable consequences if a Condition 2, 3, or 4 event occurs while the AFD is outside its specified limits. II, III, or IV

APPLICABILITY The AFD requirements are applicable in MODE 1 greater than or equal to 50% RTP when the combination of THERMAL POWER and core peaking factors are of primary importance in safety analysis.

ACTIONS A.1 For AFD limits developed using RAOC methodology, As an alternative to restoring the AFD to within its specified limits, the value of the AFD does Required Action A.1 requires a THERMAL POWER reduction to < 50% RTP. This places the core in a condition for which the value of the not affect the limiting AFD is not important in the applicable safety analyses. A Completion accident consequences with THERMAL POWER < 50% RTP and for lower operatingp ower MODES. SEQUOYAH – UNIT 1 B 3.2.3-2 Revision 49 AFD B 3.2.3

BASES

ACTIONS (continued)

Time of 30 minutes is reasonable, based on operating experience, to reach 50% RTP without challenging plant systems.

SURVEILLANCE SR 3.2.3.1 REQUIREMENTS This Surveillance verifies that the AFD, as indicated by the NIS excore channels channel, is within its specified limits.

The Surveillance Frequency is controlled under the Surveillance Frequency Control Program.

REFERENCES 1. BAW-10163P-A, Revision 0, "Core Operating Limit Methodology for Westinghouse-Designed PWRs," June 1989. 1. 2. UFSAR, Chapter 15. 2. 3. UFSAR, Section 4.3.2.

3. WCAP-8385 (Westinghouse proprietary), "Power Distribution Control and Load Following Procedures,"

Westinghouse Electric Corporation, September 1974.

4. WCAP-10216-P-A, Rev. 1A, “Relaxation of Constant Axial Offset Control (and) FQ Surveillance Technical Specification,” February 1994.

SEQUOYAH – UNIT 1 B 3.2.3-3 Revision 45 Insert 3.2.3-A RAOC is a calculational procedure that defines the allowed operational space of the AFD versus THERMAL POWER. The AFD limits are selected by considering a range of axial xenon distributions that may occur as a result of large variations of the AFD. Subsequently, power peaking factors and power distributions are examined to ensure that the LOCA and transient limits are met. Violation of the AFD limits invalidates the conclusions of the accident and transient analyses with regard to fuel cladding integrity.

Insert 3.2.3-B Although the RAOC defines limits that must be met to satisfy safety analyses, typically an operating scheme such as Constant Axial Offset Control (CAOC) is used to control axial power distribution in day to day operation (Ref. 3). CAOC requires that the AFD be controlled within a narrow tolerance band around a burnup dependent target to minimize the variation of axial peaking factors and axial xenon distribution during Unit maneuvers. The CAOC operating space is typically smaller and lies within the RAOC operating space. Control within the CAOC operating space constrains the variation of axial xenon distributions and axial power distributions. RAOC calculations assume a wide range of xenon distributions and then confirm that the resulting power distributions satisfy the requirements of the accident analyses.

Insert 3.2.3-C The RAOC methodology (Ref. 4) establishes a xenon distribution library with tentatively wide AFD limits. One dimensional axial power distribution calculations are then performed to demonstrate that normal operation power shapes are acceptable for the loss of coolant accident and loss of flow accident, and for initial conditions of anticipated transients. The tentative limits are adjusted as necessary to meet the safety analysis requirements.

QPTR B 3.2.4

B 3.2 POWER DISTRIBUTION LIMITS

B 3.2.4 QUADRANT POWER TILT RATIO (QPTR)

BASES

BACKGROUND The QPTR limit ensures that the gross radial power distribution remains consistent with the design values used in the safety analyses. Precise radial power distribution measurements are made during startup testing, after refueling, and periodically during power operation.

The power density at any point in the core must be limited so that the fuel design criteria are maintained. Together, LCO 3.2.3, "AXIAL FLUX DIFFERENCE (AFD)," LCO 3.2.4, and LCO 3.1.6, "Control Bank Insertion Limits," provide limits on process variables that characterize and control the three dimensional power distribution of the reactor core. Control of these variables ensures that the core operates within the fuel design criteria and that the power distribution remains within the bounds used in the safety analyses.

APPLICABLE This LCO precludes core power distributions that violate the following fuel SAFETY design criteria: ANALYSES 10 CFR 50.46 a. During a large break loss of coolant accident, the peak cladding acceptance criteria must temperature must not exceed 2200°F (Ref. 1), be met b. During a loss of forced reactor coolant flow accident, there must be at During Condition II least 95% probability at the 95% confidence level (the 95/95 departure from nucleate boiling (DNB) criterion) that the hot fuel rod events, in the core does not experience a DNB condition,

c. During an ejected rod accident, the energy deposition to the fuel must not exceed 280 cal/gm (Ref. 2), and 200 d. The control rods must be capable of shutting down the reactor with a minimum required SDM with the highest worth control rod stuck fully withdrawn (Ref. 3).

The LCO limits on the AFD, the QPTR, the Heat Flux Hot Channel Factor N (FQ(X,Y,Z)), the Nuclear Enthalpy Rise Hot Channel Factor (FǻH(X,Y)) and control bank insertion are established to preclude core power distributions that exceed the safety analyses limits. N The QPTR limits ensure that FǻH(X,Y) and FQ(X,Y,Z) remain below their limiting values by preventing an undetected change in the gross radial power distribution.

SEQUOYAH – UNIT 1 B 3.2.4-1 Revision 49 QPTR B 3.2.4

BASES

APPLICABLE SAFETY ANALYSES (continued) N In MODE 1, the Fǻ+(X,Y) and FQ(X,Y,Z) limits must be maintained to preclude core power distributions from exceeding design limits assumed in the safety analyses.

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

LCO The QPTR limit of 1.02, at which corrective action is required, provides a margin of protection for both the DNB ratio and linear heat generation rate contributing to excessive power peaks resulting from X-Y plane power tilts. A limiting QPTR of 1.02 can be tolerated before the margin for N uncertainty in FQ(X,Y,Z) and Fǻ+(X,Y) is possibly challenged.

APPLICABILITY The QPTR limit must be maintained in MODE 1 with THERMAL POWER > 50% RTP to prevent core power distributions from exceeding the design limits.

Applicability in MODE ” 50% RTP and in other MODES is not required because there is either insufficient stored energy in the fuel or insufficient energy being transferred to the reactor coolant to require the implementation of a QPTR limit on the distribution of core power. The N QPTR limit in these conditions is, therefore, not important. Note that the

Fǻ+(X,Y) and FQ(X,Y,Z) LCOs still apply, but allow progressively higher peaking factors at 50% RTP or lower.

ACTIONS A.1

With the QPTR exceeding its limit, a power level reduction of 3% RTP for each 1% by which the QPTR exceeds 1.02 is a conservative tradeoff of total core power with peak linear power. The Completion Time of 2 hours allows sufficient time to identify the cause and correct the tilt. Note that the power reduction itself may cause a change in the tilted condition.

The maximum allowable power level initially determined by Required Action A.1 may be affected by subsequent determinations of QPTR. Increases in QPTR would require power reduction within 2 hours of QPTR determination, if necessary to comply with the decreased maximum allowable power level. Decreases in QPTR would allow increasing the maximum allowable power level and increasing power up to this revised limit. that are not within limit and could require further power reductions within 2 hours of the subsequent QPTR determination, if necessary to comply with the decreased maximum allowable power level. In short, the 2-hour Completion Time for Required Action A.1 applies after each QPTR determination. Decreases in subsequent QPTR determinations while in Condition A would allow increasing the maximum allowable power level and increasing power up to this revised limit.

SEQUOYAH – UNIT 1 B 3.2.4-2 Revision 45 QPTR B 3.2.4

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ACTIONS (continued)

A.2

After completion of Required Action A.1, the QPTR alarm may still be in its alarmed state. As such, any additional changes in the QPTR are detected by requiring a check of the QPTR once per 12 hours thereafter. A 12 hour Completion Time is sufficient because any additional change in QPTR would be relatively slow.

a power distribution A.3 N measurement using either the movable The peaking factors FQ(X,Y,Z) and Fǻ+(X,Y) are of primary importance in incore detector system ensuring that the power distribution remains consistent with the initial N or the Power conditions used in the safety analyses. Performing SRs on Fǻ+(X,Y) and Distribution Monitoring FQ(X,Y,Z) within the Completion Time of 24 hours after achieving System equilibrium conditions from a Thermal Power reduction per Required Action A.1 ensures that these primary indicators of power distribution are THERMAL within their respective limits. Equilibrium conditions are achieved when POWER the core is sufficiently stable at intended operating conditions to support flux mapping. A Completion Time of 24 hours after achieving equilibriumpower conditions from Thermal Power reduction per Required Action A.1 takes distribution THERMAL into consideration the rate at which peaking factors are likely to change, measure- POWER and the time required to stabilize the plant and perform a flux map. If ment. these peaking factors are not within their limits, the Required Actions of the applicable LCOs of these Surveillances provide an appropriate response for the abnormal condition. If the QPTR remains above its N specified limit, the peaking factor surveillances are required each 7 days thereafter to evaluate F (X,Y) and F (X,Y,Z) with changes in power ǻ+ Q once per distribution. Relatively small changes are expected due to either burnup and xenon redistribution or correction of the cause for exceeding the QPTR limit.

A.4 N

Although Fǻ+(X,Y) and FQ(X,Y,Z) are of primary importance as initial conditions in the safety analyses, other changes in the power distribution may occur as the QPTR limit is exceeded and may have an impact on the validity of the safety analysis. A change in the power distribution can affect such reactor parameters as bank worths and peaking factors for rod malfunction accidents. When the QPTR exceeds its limit, it does not

SEQUOYAH – UNIT 1 B 3.2.4-3 Revision 45 QPTR B 3.2.4

BASES

ACTIONS (continued)

necessarily mean a safety concern exists. It does mean that there is an indication of a change in the gross radial power distribution that requires an investigation and evaluation that is accomplished by examining the incore power distribution. Specifically, the core peaking factors and the quadrant tilt must be evaluated because they are the factors that best characterize the core power distribution. This re-evaluation is required to ensure that, before increasing THERMAL POWER to above the limit of Required Action A.1, the reactor core conditions are consistent with the assumptions in the safety analyses.

A.5

If the QPTR is still exceeding the 1.02 limit and a re-evaluation of the safety analysis is completed and shows that safety requirements are met, the excore detectors shall be normalized to restore QPTR to within limits prior to increasing THERMAL POWER to above the limit of Required Action A.1. Normalization is accomplished in such a manner that the indicated QPTR following normalization is near 1.02. This is done to detect any subsequent significant changes in QPTR. 1.00

Required Action A.5 is modified by two Notes. Note 1 states that the QPTR shall not be restored to within limits by excore detector normalization until after the re-evaluation of the safety analysis has a power distribution determined that core conditions at RTP are within the safety analysis measurement using assumptions (i.e., Required Action A.4). Note 2 states that if Required either the movable Action A.5 is performed, then Required Action A.6 shall be performed. Required Action A.5 normalizes the excore detectors to restore QPTR to incore detector system within limits, which restores compliance with LCO 3.2.4. Thus, Note 2 or the Power prevents exiting the Actions prior to completing flux mapping to verify Distribution Monitoring peaking factors, per Required Action A.6. These Notes are intended to System prevent any ambiguity about the required sequence of actions.

A.6

Once the flux tilt is restored to within limits (i.e., Required Action A.5 is performed), it is acceptable to return to full power operation. However, as an added check that the core power distribution is consistent with the safety analysis assumptions, Required Action A.6 requires verification

SEQUOYAH – UNIT 1 B 3.2.4-4 Revision 45 QPTR B 3.2.4 FQ(Z), as approximated by C W FQ (Z) and FQ (Z), and BASES

ACTIONS (continued) N

that FQ(X,Y,Z) and Fǻ+(X,Y) are within their specified limits within 24 hours of achieving equilibrium conditions at RTP. As an added precaution, if the core power does not reach equilibrium conditions at RTP within 24 hours, but is increased slowly, then the peaking factor surveillances must be performed within 48 hours after increasing THERMAL POWER above the limit of Required Action A.1. These Completion Times are intended to allow adequate time to increase THERMAL POWER to above the limit of Required Action A.1, while not permitting the core to remain with unconfirmed power distributions for extended periods of time.

Required Action A.6 is modified by a Note that states that the peaking factor surveillances may only be done after the excore detectors have been normalized to restore QPTR to within limits (i.e., Required Action A.5). The intent of this Note is to have the peaking factor surveillances performed at operating power levels, which can only be accomplished after the excore detectors are normalized to restore QPTR to within limits and the core returned to power.

B.1

If Required Actions A.1 through A.6 are not completed within their associated Completion Times, the unit must be brought to a MODE or condition in which the requirements do not apply. To achieve this status, THERMAL POWER must be reduced to ” 50% RTP within 4 hours. The allowed Completion Time of 4 hours is reasonable, based on operating experience regarding the amount of time required to reach the reduced power level without challenging plant systems.

SURVEILLANCE SR 3.2.4.1 excore REQUIREMENTS SR 3.2.4.1 is modified by two Notes. Note 1 allows QPTR to be calculated with three power range channels if THERMAL POWER is ” 75% RTP and the input from one Power Range Neutron Flux channel is inoperable. Note 2 allows performance of SR 3.2.4.2 in lieu of SR 3.2.4.1.

This Surveillance verifies that the QPTR, as indicated by the Nuclear Instrumentation System (NIS) excore channels, is within its limits.

The Surveillance Frequency is controlled under the Surveillance Frequency Control Program.

SEQUOYAH – UNIT 1 B 3.2.4-5 Revision 45 QPTR B 3.2.4

BASES

SURVEILLANCE REQUIREMENTS (continued)

For those causes of QPTR that occur quickly (e.g., a dropped rod), there typically are other indications of abnormality that prompt a verification of core power tilt. only

SR 3.2.4.2

This Surveillance is modified by a Note, which states that it is not required until 12 hours after the input from one or more Power Range Neutron Flux channels are inoperable and the THERMAL POWER is > 75% RTP.

With an NIS power range channel inoperable, tilt monitoring for a portion of the reactor core becomes degraded. Large tilts are likely detected with the remaining channels, but the capability for detection of small power tilts in some quadrants is decreased.

or a The Surveillance Frequency is controlled under the Surveillance Frequency Control Program. functional PDMS When using For purposes of monitoring the QPTR when one power range channel is the movable inoperable, the moveable incore detectors are used to confirm that the incore normalized symmetric power distribution is consistent with the indicated QPTR and any previous data indicating a tilt. The incore detector detector monitoring is performed with a full incore flux map or two sets of four system, the thimble locations with quarter core symmetry. The two sets of four quadrant power tilt. symmetric thimbles is a set of eight unique detector locations. These locations are C-8, E-5, E-11, H-3, H-13, L-5, L-11, and N-8. Alternatively, when using a functional PDMS, the incore The symmetric thimble flux map can be used to generate symmetric quadrant power tilt generated thimble "tilt." This can be compared to a reference symmetric thimble tilt, by it can be compared to the from the most recent full core flux map, to generate an incore QPTR. incore power tilt prior to the Therefore, incore monitoring of QPTR can be used to confirm that QPTR is within limits. loss of the power range quadrant power tilt channel. With one NIS channel inoperable, the indicated tilt may be changed from the value indicated with all four channels OPERABLE. To confirm that no core power change in tilt has actually occurred, which might cause the QPTR limit to distribution be exceeded, the incore result may be compared against previous flux measurements maps either using the symmetric thimbles as described above or a using a complete flux map. Nominally, quadrant tilt from the Surveillance should functional be within 2% of the tilt shown by the most recent flux map data.

PDMS and power distribution power measurement distribution measurements

SEQUOYAH – UNIT 1 B 3.2.4-6 Revision 45 QPTR B 3.2.4

BASES

REFERENCES 1. 10 CFR 50.46. WCAP-18459-P, Revision 1, 2. Regulatory Guide 1.77, Rev. 0, May 1974. “Sequoyah Units 1 and 2 Reload Transition Safety Report with 3. 10 CFR 50, Appendix A, GDC 26. RFA-2 Fuel,” June 2020.

SEQUOYAH – UNIT 1 B 3.2.4-7 Revision 45 RTS Instrumentation B 3.3.1

BASES

APPLICABLE SAFETY ANALYSES, LCO, and APPLICABILITY (continued)

actuate the safety valves, and the high pressure reactor trip is set below the safety valve setting. Therefore, with the slow rate of charging available, pressure overshoot due to level channel failure cannot cause the safety valve to lift before reactor high pressure trip.

There are three Pressurizer Level - High channels arranged in a two- out-of-three logic. In MODE 1, when there is a potential for overfilling the pressurizer, the Pressurizer Water Level - High trip must be OPERABLE. This trip Function is automatically enabled on increasing power by the P-7 interlock. On decreasing power, this trip Function is automatically blocked below P-7.

10. Reactor Coolant Flow - Low

The Reactor Coolant Flow - Low trip Function ensures that protection is provided against violating the DNBR limit due to low flow in one or more RCS loops, while avoiding reactor trips due to normal variations in loop flow. Above the P-7 setpoint, the reactor trip on low flow in two or more RCS loops is automatically enabled. Above the P-8 setpoint, which is approximately 35% RTP, a loss of flow in any RCS loop will actuate a reactor trip. Each RCS loop has three flow detectors to monitor flow. There are three per loop Reactor Coolant Flow - Low channels using these detectors and are arranged in a two-out-of-three logic for each loop. The flow signals are not used for any control system input.

Design flow is 94,600 (91,400 X 1.035) gpm per loop (Reference 14). UFSAR Table 5.1-1 lists this value as the Full Power Operability Flow, gpm/loop.

The LCO requires three Reactor Coolant Flow - Low channels per loop to be OPERABLE in MODE 1 above P-7.

In MODE 1 above the P-8 setpoint, a loss of flow in one RCS loop could result in DNB conditions in the core because of the higher power level. In MODE 1 below the P-8 setpoint and above the P-7 setpoint, a loss of flow in two or more loops is required to actuate a reactor trip because of the lower power level and the greater margin to the design limit DNBR. Below the P-7 setpoint, all reactor trips on low flow are automatically blocked.

SEQUOYAH – UNIT 1 B 3.3.1-20 Revision 45

RTS Instrumentation B 3.3.1

BASES

SURVEILLANCE REQUIREMENTS (continued)

SR 3.3.1.2

SR 3.3.1.2 compares the calorimetric heat balance calculation to the power range channel output. If the absolute difference is greater than 2 percent, the power range channel is not declared inoperable, but must be adjusted. The power range channel output shall be adjusted consistent with the calorimetric heat balance calculation results if the absolute difference is greater than 2 percent. If the power range channel output cannot be properly adjusted, the channel is declared inoperable.

The Note clarifies that this Surveillance is required only if reactor power is •573DQGWKDWKRXUVDUHDOORZHGIRUSHUIRUPLQJWKHILUVW Surveillance after reaching 15% RTP. A power level of 15% RTP is chosen based on plant stability, i.e., automatic rod control capability and turbine generator synchronized to the grid.

The Surveillance Frequency is controlled under the Surveillance Frequency Control Program.

SR 3.3.1.3

SR 3.3.1.3 compares the incore power distribution measurements system to the NIS channel outpuW,IWKHDEVROXWHGLIIHUHQFHLV•WKH NIS channel is still OPERABLE, but must be readjusted. The excore NIS channel shall be adjusted if the absolute difference between the incore DQGH[FRUH$)'LV• The core power distribution measurements can be obtained using the movable incore detectors or a functional power distribution monitoring system (PDMS).

If the NIS channel cannot be properly readjusted, the channel is declared LQRSHUDEOH7KLV6XUYHLOODQFHLVSHUIRUPHGWRYHULI\WKHI ¨, LQSXWWRWKH RYHUWHPSHUDWXUH¨7DQGRYHUSRZHU¨7)XQFWLRQV

A Note clarifies that the Surveillance is required only if reactor power is •573DQGWKDWKRXUVareis allowed for performing the first Surveillance after reaching 15% RTP.

The Surveillance Frequency is controlled under the Surveillance Frequency Control Program.

SEQUOYAH – UNIT 1 B 3.3.1-45 Revision 45

RTS Instrumentation B 3.3.1

BASES

SURVEILLANCE REQUIREMENTS (continued)

SR 3.3.1.4

SR 3.3.1.4 is the performance of a TADOT. This test shall verify OPERABILITY by actuation of the end devices. A successful test of the required contact(s) of a channel relay may be performed by the verification of the change of state of a single contact of the relay. This clarifies what is an acceptable TADOT of a relay. This is acceptable because all of the other required contacts of the relay are verified by other Technical Specifications and non-Technical Specifications tests at least once per refueling interval with applicable extensions.

The reactor trip breaker test shall include separate verification of the undervoltage and shunt trip mechanisms. Independent verification of reactor trip breaker undervoltage and shunt trip Function is not required for the bypass breakers. No capability is provided for performing such a test at power. The independent test for bypass breakers is included in SR 3.3.1.12. The bypass breaker test shall include a local shunt trip. A Note has been added to indicate that this test must be performed on the bypass breaker prior to placing it in service.

The Surveillance Frequency is controlled under the Surveillance Frequency Control Program.

SR 3.3.1.5

SR 3.3.1.5 is the performance of an ACTUATION LOGIC TEST. The SSPS is tested using the semiautomatic tester. The train being tested is placed in the bypass condition, thus preventing inadvertent actuation. Through the semiautomatic tester, all possible logic combinations, with and without applicable permissives, are tested for each protection function, including operation of the P-7 permissive which is a logic function only.

The Surveillance Frequency is controlled under the Surveillance Frequency Control Program.

SR 3.3.1.6

SR 3.3.1.6 is a calibration of the excore channels to the incore power distribution measurementschannels. If the measurements do not agree, the excore channels are not declared inoperable but must be calibrated to agree with the incore power distribution detector measurements. The core power distribution measurements can be obtained using the movable incore detectors or a functional

SEQUOYAH – UNIT 1 B 3.3.1-46 Revision 45

RTS Instrumentation B 3.3.1

BASES SURVEILLANCE REQUIREMENTS (continued) power distribution monitoring system (PDMS). If the excore channels cannot be adjusted, the channels are declared inoperable. This 6XUYHLOODQFHLVSHUIRUPHGWRYHULI\WKHI ¨, LQSXWWRWKHRYHUWHPSHUDWXUH ¨7DQGRYHUSRZHU¨7)XQFWLRQV

A Note modifies SR 3.3.1.6. The Note states that this Surveillance is required only if reactor power is >greater than or equal to 50% RTP and that 24 hours is allowed for performing the first surveillance after reaching 50% RTP.

The Surveillance Frequency is controlled under the Surveillance Frequency Control Program.

SR 3.3.1.7

SR 3.3.1.7 is the performance of a COT.

A COT is performed on each required channel to ensure the entire channel will perform the intended Function. A successful test of the required contact(s) of a channel relay may be performed by the verification of the change of state of a single contact of the relay. This clarifies what is an acceptable COT of a relay. This is acceptable because all of the other required contacts of the relay are verified by other Technical Specifications and non-Technical Specifications tests at least once per refueling interval with applicable extensions.

Setpoints must be conservative with respect to the Allowable Values specified in Table 3.3.1-1.

The difference between the current "as found" values and the previous test "as left" values must be consistent with the drift allowance used in the setpoint methodology. The setpoint shall be left set consistent with the assumptions of the current unit specific setpoint methodology.

The "as-found" and "as-left" values must also be recorded and reviewed for consistency with the assumptions of Reference 9.

SR 3.3.1.7 is modified by a Note that provides a 4 hour delay in the requirement to perform this Surveillance for source range instrumentation when entering MODE 3 from MODE 2. This Note allows a normal shutdown to proceed without a delay for testing in MODE 2 and for a short time in MODE 3 until the reactor trip breakers are open and SR 3.3.1.7 is no longer required to be performed. If the unit is to be in MODE 3 with the reactor trip breakers closed for > 4 hours this Surveillance must be performed prior to 4 hours after entry into MODE 3.

The Surveillance Frequency is controlled under the Surveillance Frequency Control Program.

SEQUOYAH – UNIT 1 B 3.3.1-47 Revision 45 RTS Instrumentation B 3.3.1

BASES

REFERENCES 1. Regulatory Guide 1.105, Revision 3, "Setpoints for Safety Related Instrumentation."

2. UFSAR, Chapter 7.

3. UFSAR, Chapter 6.

4. UFSAR, Chapter 15.

5. IEEE-279-1971.

6. 10 CFR 50.49.

7. Calculation SQN-EEB-PL&S, Precautions, Limitations, and Setpoints for NSSS.

8. WCAP-14333-P-A, Rev. 1, October 1998.

9. WCAP-10271-P-A, Supplement 1, May 1986.

10. WCAP-13632-P-A, Revision 2, "Elimination of Pressure Sensor Response Time Testing Requirements," January 1996.

11. WCAP-10271-P-A, Supplement 2, June 1990.

12. WCAP-15376, Rev. 0, October 2000.

13. WCAP-14036-P, Revision 1, "Elimination of Periodic Protection Channel Response Time Tests," December 1995.

14. Letter from Siva P. Lingam (NRC) to Joseph W. Shea (TVA), "Sequoyah Nuclear Plant, Units 1 and 2 - Issuance of Amendments to Revise the Technical Specification to allow use of Areva Advanced W17 High Performance Fuel (TS-SQN-2011-07) (TAC NOS. ME6538 and ME6539)," dated September 26, 2012.

SEQUOYAH – UNIT 1 B 3.3.1-55 Revision 45 Engineered Safety Feature Actuation System (ESFAS) Instrumentation B 3.3.2

BASES

APPLICABLE SAFETY ANALYSES, LCO, and APPLICABILITY (continued)

A trip setpoint may be set more conservative than the NTSP as necessary in response to plant conditions. However, in this case, the OPERABILITY of this instrument must be verified based on the field setting and not the NTSP. Failure of any instrument renders the affected channel(s) inoperable and reduces the reliability of the affected Functions.

The LCO generally requires OPERABILITY of four or three channels in each instrumentation function and two channels in each logic and manual initiation function. The two-out-of-three and the two-out-of-four configurations allow one channel to be tripped during maintenance or testing without causing an ESFAS initiation. Two logic or manual initiation channels are required to ensure no single random failure disables the ESFAS.

The required channels of ESFAS instrumentation provide unit protection in the event of any of the analyzed accidents. ESFAS protection functions are as follows: compliance with 1. Safety Injection the 10 CFR 50.46 acceptance criteria Safety Injection (SI) provides two primary functions: (Ref. 16)

1. Primary side water addition to ensure maintenance or recovery of reactor vessel water level (coverage of the active fuel for heat removal, clad integrity, and for limiting peak clad temperature to < 2200°F), and

2. Boration to ensure recovery and maintenance of SDM (keff < 1.0).

These functions are necessary to mitigate the effects of high energy line breaks (HELBs) both inside and outside of containment. The SI signal is also used to initiate other Functions such as:

x Phase A Isolation,

x Containment Ventilation Isolation,

x Reactor Trip,

x ERCW and CCS Pump Start and System Isolation,

x Turbine Trip,

x Feedwater Isolation,

SEQUOYAH – UNIT 1 B 3.3.2-8 Revision 45 Engineered Safety Feature Actuation System (ESFAS) Instrumentation B 3.3.2

BASES

REFERENCES (continued)

10. WCAP-10271-P-A, Supplement 2, Rev. 1, June 1990.

11. License Amendment dated June 13, 1995, Issuance of Amendments to Technical Specifications – Sequoyah Nuclear Plant, Units 1 and 2 (TAC NOS. M91990 and 91991) (ML013320052).

12. WCAP-15376, Rev. 0. October 2000.

13. UFSAR, Section 7.3.

14. WCAP-13632-P-A, Revision 2, "Elimination of Pressure Sensor Response Time Testing Requirements," January 1996.

15. WCAP-14036-P, Revision 1, "Elimination of Periodic Protection Channel Response Time Tests," December 1995.

16. 10 CFR 50.46.

SEQUOYAH – UNIT 1 B 3.3.2-53 Revision 45

RCS Pressure, Temperature, and Flow DNB Limits B 3.4.1

B 3.4 REACTOR COOLANT SYSTEM (RCS)

B 3.4.1 RCS Pressure, Temperature, and Flow Departure from Nucleate Boiling (DNB) Limits

BASES

BACKGROUND These Bases address requirements for maintaining RCS pressure, temperature, and flow rate within limits assumed in the safety analyses. The safety analyses (Ref. 1) of normal operating conditions and anticipated operational occurrences assume initial conditions within the normal steady state envelope. The limits placed on RCS pressure, temperature, and flow rate ensure that the minimum departure from nucleate boiling ratio (DNBR) will be met for each of the transients analyzed.

The RCS pressure limit is consistent with operation within the nominal operational envelope. Each pressurizer pressure indication is compared to the limit. A lower pressure will cause the reactor core to approach DNB limits.

The RCS coolant average temperature limit is consistent with full power operation within the nominal operational envelope. Indications of temperature are averaged to determine a value for comparison to the limit. A higher average temperature will cause the core to approach DNB limits.

The RCS flow rate normally remains constant during an operational fuel cycle with all pumps running. The minimum RCS flow limit corresponds to that assumed for DNB analyses. Each OPERABLE flow rate indication is compared to the limit. If one or more flow rate indications are unavailable, the remaining flow rate indications are averaged to come up with a value for comparison to the limit. A lower RCS flow will cause the core to approach DNB limits.

Operation for significant periods of time outside these DNB limits increases the likelihood of a fuel cladding failure in a DNB limited event.

APPLICABLE The requirements of this LCO represent the initial conditions for DNB SAFETY limited transients analyzed in the plant safety analyses (Ref. 1). The ANALYSES safety analyses have shown that transients initiated from the limits of this LCO will result in meeting the DNBR limitscriterion. This is the acceptance limit for the RCS DNB parameters. Changes to the unit that could impact these parameters must be assessed for their impact on the DNBR criteria. The transients analyzed for include loss of coolant flow events and dropped or misaligned rod events. A key assumption for the analysis of these events is that the core power distribution is within the limits of LCO 3.1.4, “Rod Group Alignment Limits,” LCO 3.1.5, “Shutdown Bank Insertion Limits,” LCO 3.1.6, "Control Bank Insertion Limits," LCO 3.2.3, "AXIAL FLUX DIFFERENCE (AFD)," and LCO 3.2.4, "QUADRANT POWER TILT RATIO (QPTR)."

SEQUOYAH – UNIT 1 B 3.4.1-1 Revision 45

RCS Pressure, Temperature, and Flow DNB Limits B 3.4.1

BASES

APPLICABLE SAFETY ANALYSES (continued)

The pressurizer pressure limit and RCS average temperature limit, as specified in the COLR, correspond to the analytical limits used in the safety analyses, with allowance for measurement uncertainty.

The RCS DNB parameters satisfy Criterion 2 of 10 CFR 50.36(c)(2)(ii).

LCO This LCO specifies limits on the monitored process variables - pressurizer pressure, RCS average temperature, and RCS total flow rate - to ensure the core operates within the limits assumed in the safety analyses. The limit values for pressurizer pressure and RCS average temperature are specified in the COLR to provide operating and analysis flexibility from cycle to cycle. The minimum RCS flow is based on the maximum analyzed steam generator tube plugging. Operating within these limits will result in meeting the DNBR limits criterion in the event of a DNB limited transient.

RCS flow indication calibration must include appropriate considerations for the accuracy of feedwater flow measurement. Sequoyah Nuclear Plant (SQN) can employ either of two methods to measure feedwater flow; an installed Leading Edge Flow Meter (LEFM), or in-line feedwater flow venturis. Unlike the feedwater venturis, the LEFM is not susceptible to fouling during use and possesses a higher accuracy. These attributes make the LEFM the preferred method of measuring feedwater flow as an input to the determination of RCS flow.

In the event the LEFM is unavailable, the feedwater venturis are used to calibrate the RCS flow indicators. However, the calibration assumptions for flow measurement uncertainties areis not applicable to the case where the power calorimetric is based on the venturi feedwater flow indication, even if the LEFM is used to correct the venturi feedwater flow indications for the effects of fouling. For those instances where the LEFM is unavailable, SQN Technical Requirements Manual (TRM) specifies the appropriate actions to be taken.

The numerical values for pressure, temperature, and flow rate specified in the LCO and COLR are given for the measurement location and have been adjusted for instrument error.

APPLICABILITY In MODE 1, the limits on pressurizer pressure, RCS coolant average temperature, and RCS flow rate must be maintained during steady state operation in order to ensure DNBR limits criteria will be met in the event of an unplanned loss of forced coolant flow or other DNB limited transient. In all other MODES, the power level is low enough that DNB is not a concern.

SEQUOYAH – UNIT 1 B 3.4.1-2 Revision 45

RCS Pressure, Temperature, and Flow DNB Limits B 3.4.1

BASES

APPLICABILITY (continued)

A Note has been added to indicate the limit on pressurizer pressure is not applicable during short term operational transients such as a THERMAL POWER ramp increase > 5% RTP per minute or a THERMAL POWER step increase > 10% RTP. Additionally, the limit on pressurizer pressure is not applicable during PHYSICS TESTS and during the performance of SR 3.1.3.2, moderator temperature coefficient (MTC) determination. Measurement of MTC has a high probability of causing a drop in pressure below the specified value, because the reactor coolant system temperature must be dropped several degrees below T avg for an accurate MTC measurement. This results in an associated drop in pressurizer level and in a downswing of pressurizer pressure, making it difficult to maintain pressurizer pressure above the limit. These conditions represent short term perturbations where actions to control pressure variations might be counterproductive. Also, since they represent transients initiated from power levels < 100% RTP, an increased DNBR margin exists to offset the temporary pressure variations.

The DNBR limit is provided in SL 2.1.1, "Reactor Core SLs." The conditions which define the DNBR limit are less restrictive than the limits of this LCO, but violation of a Safety Limit (SL) merits a stricter, more severe Required Action. Should a violation of this LCO occur, the operator must check whether or not an SL may have been exceeded.

ACTIONS A.1

RCS pressure and RCS average temperature are controllable and measurable parameters. With one or both of these parameters not within LCO limits, action must be taken to restore parameter(s).

RCS total flow rate is not a controllable parameter and is not expected to vary during steady state operation. If the indicated RCS total flow rate is below the LCO limit, power must be reduced, per Required Action B.1, to restore DNB margin and eliminate the potential for violation of the accident analysis limitsbounds.

The 2 hour Completion Time for restoration of the parameters provides sufficient time to adjust plant parameters, to determine the cause for the off normal condition, and to restore the readings within limits, and is based on plant operating experience.

B.1

If Required Action A.1 is not met within the associated Completion Time, the plant must be brought to a MODE in which the LCO does not apply. To achieve this status, the plant must be brought to at least MODE 2 within 6 hours. In MODE 2, the reduced power condition eliminates the

SEQUOYAH – UNIT 1 B 3.4.1-3 Revision 45

RCS Pressure, Temperature, and Flow DNB Limits B 3.4.1

BASES

ACTIONS (continued)

potential for violation of the accident analysis limitsbounds. The Completion Time of 6 hours is reasonable to reach the required plant conditions in an orderly manner.

SURVEILLANCE SR 3.4.1.1 REQUIREMENTS Periodic verification that pressurizer pressure is greater than or equal to the limit specified in the COLR ensures that pressure can be restored to a normal operation, steady state condition following load changes and other expected transient operations. This information is used to assess potential degradation and to verify operation is within safety analysis assumptions. The Surveillance Frequency is controlled under the Surveillance Frequency Control Program.

SR 3.4.1.2

Periodic verification that RCS average temperature is less than or equal to the limit specified in the COLR ensures that temperature can be restored to a normal operation, steady state condition following load changes and other expected transient operations. This information is used to assess potential degradation and to verify operation is within safety analysis assumptions. The Surveillance Frequency is controlled under the Surveillance Frequency Control Program.

SR 3.4.1.3

Periodic verification that RCS total flow rate is greater than or equal to 360,000 gpm and greater than or equal to the limit specified in the COLR is performed using the installed flow instrumentation. This information is used to assess potential degradation and to verify operation is within safety analysis assumptions. The Surveillance Frequency is controlled under the Surveillance Frequency Control Program.

SR 3.4.1.4

Measurement of RCS total flow rate by performance of an elbow tap differential flow method (Ref. 2) allows the installed RCS flow instrumentation to be calibrated and verifies the actual RCS flow rate is greater than or equal to 360,000 gpm and greater than or equal to the limit specified in the COLRthe minimum required RCS flow rate.

SEQUOYAH – UNIT 1 B 3.4.1-4 Revision 45 Accumulators B 3.5.1

B 3.5 EMERGENCY CORE COOLING SYSTEMS (ECCS)

B 3.5.1 Accumulators

large break BASES

BACKGROUND The functions of the ECCS accumulators are to supply water to the reactor vessel during the blowdown phase of a loss of coolant accident (LOCA), to provide inventory to help accomplish the refill phase that follows thereafter, and to provide Reactor Coolant System (RCS) makeup for a small break LOCA.

The blowdown phase of a large break LOCA is the initial period of the transient during which the RCS departs from equilibrium conditions, and heat from fission product decay, hot internals, and the vessel continues to be transferred to the reactor coolant. The blowdown phase of the transient ends when the RCS pressure falls to a value approaching that of the containment atmosphere.

In the refill phase of a large break LOCA, which immediately follows the blowdown phase, reactor coolant inventory has vacated the core through steam flashing and ejection out through the break. The core is essentially in adiabatic heatup. The balance of accumulator inventory is then available to help fill voids in the lower plenum and reactor vessel downcomer so as to establish a recovery level at the bottom of the core and ongoing reflood of the core with the addition of safety injection (SI) water.

Initial accumulator The accumulators are pressure vessels partially filled with borated water inventory which is and pressurized with nitrogen gas. The accumulators are passive injected into the components, since no operator or control actions are required in order for reactor vessel is them to perform their function. Internal accumulator tank pressure is lost out the break. sufficient to discharge the accumulator contents to the RCS, if RCS pressure decreases below the accumulator pressure.

Each accumulator is piped into an RCS cold leg via an accumulator line and is isolated from the RCS by a motor operated isolation valve and two check valves in series.

The accumulator size, water volume, and nitrogen cover pressure are selected so that three of the four accumulators are sufficient to partially cover the core before significant clad melting or zirconium water reaction can occur following a large break LOCA. The need to ensure that three accumulators are adequate for this function is consistent with the large break LOCA assumption that the entire contents of one accumulator will be lost via the RCS pipe break during the blowdown phase of the large break LOCA.

SEQUOYAH – UNIT 1 B 3.5.1-1 Revision 45 Accumulators B 3.5.1

BASES

APPLICABLE The accumulators are assumed OPERABLE in both the large and small SAFETY break LOCA analyses at full power (Ref. 1). These are the Design Basis ANALYSES Accidents (DBAs) that establish the acceptance limits for the accumulators. Reference to the analyses for these DBAs is used to assess changes in the accumulators as they relate to the acceptance limits.

In performing the large break LOCA calculations, conservative assumptions are made concerning the availability of ECCS flow. In the early stages of a large break LOCA, with or without a loss of offsite power, the accumulators provide the sole source of makeup water to the RCS. The assumption of loss of offsite power is required by regulations and conservatively imposes a delay wherein the ECCS pumps cannot deliver flow until the emergency diesel generators start, come to rated speed, and go through their timed loading sequence. In cold leg break scenarios, the entire contents of one accumulator are assumed to be lost through the break.

The limiting large break LOCA is a double ended guillotine break. Based on deterministic studies, the worst break location is in the cold leg piping between the reactor coolant pump and the reactor vessel for the RCS loop containing the pressurizer. During this event, the accumulators discharge to the RCS as soon as RCS pressure decreases to belowsafety injection accumulator pressure. signal generation, (for loss of offsite power assumption) As a conservative estimate, no credit is taken for ECCS pump flow until an effective delay has elapsed. This delay accounts for the diesels starting and the pumps being loaded and delivering full flow. The delay time is conservatively set with an additional 2 seconds to account for SI signal generation. During this time, the accumulators are analyzed as providing the sole source of emergency core cooling. No operator action is assumed during the blowdown stage of a large break LOCA. analysis also assumes The worst case small break LOCA analyses also assume a time delay before pumped flow reaches the core. For the larger range of small intermediate breaks, the rate of blowdown is such that the increase in fuel clad is assumed to inject into the temperature is terminated solely by the accumulators, with pumped flow reactor coolant system. then providing continued cooling. As break size decreases, the accumulators, safety injection pumps, and centrifugal charging pumps each play a part in terminating the rise in clad temperature. As break size At very small break sizes, the continues to decrease, the role of the accumulators continues to safety injection pumps are decrease until they are not required and the safety injection and capable of mitigating the centrifugal charging pumps become responsible for terminating the temperature increase. inventory loss during the small- with break LOCA, and the This LCO helps to ensure that the following acceptance criteria accumulators do not play a established for the ECCS by 10 CFR 50.46 (Ref. 2) will be met following a significant role in the accident mitigation.

SEQUOYAH – UNIT 1 B 3.5.1-2 Revision 45 Accumulators B 3.5.1

BASES level of

APPLICABLE SAFETY ANALYSES (continued)

small break LOCA and there is a high probability that the criteria are met following a large break LOCA:

a. Maximum fuel element cladding temperature is ” 2200°F,

b. 0D[LPXPFODGGLQJR[LGDWLRQLV” 0.17 times the total cladding thickness before oxidation,

c. Maximum hydrogen generation from a zirconium water reaction is ” 0.01 times the hypothetical amount that would be generated if all of the metal in the cladding cylinders surrounding the fuel, excluding the cladding surrounding the plenum volume, were to react, and

d. Core is maintained in a coolable geometry. Both large and small- break analyses use a Since the accumulators discharge during the blowdown phase and the nominal accumulator line first few seconds of the refill phase of a large break LOCA, they do not contribute to the long term cooling requirements of 10 CFR 50.46. volume from the accumulator to the check For both the large and small break LOCA analyses, a nominal contained valve. accumulator water volume is used. The contained water volume is the same as the deliverable volume for the accumulators, since the accumulators are emptied, once discharged. The large and small break LOCA safety analyses are performed with accumulator volumes that are consistent with the LOCA evaluation models. The realistic large break LOCA safety analysis takes values between 7515 gallons and 8194 gallons. To allow for instrument inaccuracy, values of 7615 gallons and 7960 gallons are specified. The small break LOCA safety analysis assumes a value from within the range of values used for the large break safety analysis. accumulator water volumes The minimum boron concentration setpoint is used in the post LOCA boron concentration calculation. The calculation is performed to assure reactor subcriticality in a post LOCA environment. Of particular interest is the large break LOCA, since no credit is taken for control rod assembly insertion. A reduction in the accumulator minimum boron concentration would produce a subsequent reduction in the available containment sump concentration for post LOCA shutdown and an increase in the maximum sump pH. The maximum boron concentration is used in determining the cold leg to hot leg recirculation injection switchover time and minimum sump pH.

SEQUOYAH – UNIT 1 B 3.5.1-3 Revision 45 Accumulators B 3.5.1

BASES

APPLICABLE SAFETY ANALYSES (continued) accumulator pressures

The large and small break LOCA analyses are performed with accumulator pressures that are consistent with the LOCA evaluation models. The realistic large break LOCA safety analysis takes values between 600 psig and 683 psig. To allow for instrument inaccuracy, values of 624 psig and 668 psig are specified. The small break LOCA safety analysis assumes a value from the low end of the range of values taken for the large break safety analysis. The maximum nitrogen cover pressure limit prevents accumulator relief valve actuation, and ultimately preserves accumulator integrity.

The effects on containment mass and energy releases from the accumulators are accounted for in the appropriate analyses (Refs. 1 and 3).

The accumulators satisfy Criterion 3 of 10 CFR 50.36(c)(2)(ii).

LCO The LCO establishes the minimum conditions required to ensure that the accumulators are available to accomplish their core cooling safety function following a LOCA. Four accumulators are required to ensure that 100% of the contents of three of the accumulators will reach the core during a LOCA. This is consistent with the assumption that the contents of one accumulator spill through the break. If less than three accumulators are injected during the blowdown phase of a LOCA, the ECCS acceptance criteria of 10 CFR 50.46 (Ref. 2) could be violated.

For an accumulator to be considered OPERABLE, the isolation valve must be fully open, power removed above 2000 psig, and the limits established in the SRs for contained volume, boron concentration, and nitrogen cover pressure must be met.

APPLICABILITY In MODES 1 and 2, and in MODE 3 with RCS pressure > 1000 psig, the accumulator OPERABILITY requirements are based on full power operation. Although cooling requirements decrease as power decreases, the accumulators are still required to provide core cooling as long as elevated RCS pressures and temperatures exist.

This LCO is only applicable at pressures > 1000 psig. At pressures ” 1000 psig, the rate of RCS blowdown is such that the ECCS pumps can provide adequate injection to ensure that peak clad temperature remains below the 10 CFR 50.46 (Ref. 2) limit of 2200°F.

In MODE ZLWK5&6SUHVVXUH” 1000 psig, and in MODES 4, 5, and 6, the accumulator motor operated isolation valves are closed to isolate the accumulators from the RCS. This allows RCS cooldown and depressurization without discharging the accumulators into the RCS or requiring depressurization of the accumulators.

SEQUOYAH – UNIT 1 B 3.5.1-4 Revision 45 ECCS - Operating B 3.5.2

BASES

BACKGROUND (continued)

During low temperature conditions in the RCS, limitations are placed on the maximum number of ECCS pumps that may be OPERABLE. Refer to the Bases for LCO 3.4.12, "Low Temperature Overpressure Protection (LTOP) System," for the basis of these requirements.

The ECCS subsystems are actuated upon receipt of an SI signal. If offsite power is available, the safeguard loads start immediately in the programmed sequence. If offsite power is not available, the Engineered Safety Feature (ESF) buses shed normal operating loads and are connected to the emergency diesel generators (EDGs). Safeguard loads are then actuated in the programmed time sequence. The time delay associated with diesel starting, sequenced loading, and pump starting determines the time required before pumped flow is available to the core following a LOCA.

The active ECCS components, along with the passive accumulators and the RWST covered in LCO 3.5.1, "Accumulators," and LCO 3.5.4, "Refueling Water Storage Tank (RWST)," provide the cooling water necessary to meet GDC 35 (Ref. 1).

APPLICABLE The LCO helps to ensure that the following acceptance criteria for the SAFETY ECCS, established by 10 CFR 50.46 (Ref. 2), will be met following a ANALYSES LOCA: with a high level of probability a. 0D[LPXPIXHOHOHPHQWFODGGLQJWHPSHUDWXUHLV” 2200°F,

b. 0D[LPXPFODGGLQJR[LGDWLRQLV” 0.17 times the total cladding thickness before oxidation,

c. Maximum hydrogen generation from a zirconium water reaction is ” 0.01 times the hypothetical amount generated if all of the metal in the cladding cylinders surrounding the fuel, excluding the cladding surrounding the plenum volume, were to react,

d. Core is maintained in a coolable geometry, and

e. Adequate long term core cooling capability is maintained.

The LCO also limits the potential for a post trip return to power following an MSLB event and ensures that containment temperature limits are met.

SEQUOYAH – UNIT 1 B 3.5.2-3 Revision 45 RWST B 3.5.4

BASES

APPLICABLE SAFETY ANALYSES (continued)

The maximum RWST temperature ensures that the amount of cooling provided from the RWST during the heatup phase of a feedline break is consistent with safety analysis assumptions; the minimum RWST temperature is an assumption in the MSLB analysis.

The MSLB analysis has considered a delay associated with the interlock between the VCT and RWST isolation valves, and the results show that the departure from nucleate boiling design basis is met. The delay has been established as 28 seconds, with offsite power available, or 58 seconds without offsite power.

For a large break LOCA analysis, the minimum water volume limit of 370,000 gallons and the lower boron concentration limit of 2500 ppm are used to compute the post LOCA sump boron concentration necessary to assure subcriticality. The large break LOCA is the limiting case since the safety analysis assumes that all control rods are out of the core.

The upper limit on boron concentration of 2700 ppm is used to determine the maximum allowable time to switch to hot leg recirculation following a LOCA. The purpose of switching from cold leg to hot leg recirculation is to minimize the potential for boron precipitation in the core following the accident. INSERT A The RWST satisfies Criterion 3 of 10 CFR 50.36(c)(2)(ii).

LCO The RWST ensures that an adequate supply of borated water is available to cool and depressurize the containment in the event of a Design Basis Accident (DBA), to cool and cover the core in the event of a LOCA, to maintain the reactor subcritical following a DBA, and to ensure adequate level in the containment sump to support ECCS and Containment Spray System pump operation in the recirculation mode.

To be considered OPERABLE, the RWST must meet the water volume, boron concentration, and temperature limits established in the SRs.

APPLICABILITY In MODES 1, 2, 3, and 4, RWST OPERABILITY requirements are dictated by ECCS and Containment Spray System OPERABILITY requirements. Since both the ECCS and the Containment Spray System must be OPERABLE in MODES 1, 2, 3, and 4, the RWST must also be OPERABLE to support their operation.

SEQUOYAH – UNIT 1 B 3.5.4-3 Revision 45 INSERT A

In the ECCS analysis, the containment spray temperature is assumed to be 55°F, which accounts for measurement uncertainty on the 60°F RWST minimum temperature. If the lower temperature limit is violated, the containment spray further reduces containment pressure, which decreases the rate at which steam can be vented out the break and increases peak clad temperature. The acceptable temperature range of 55°F to 110°F is assumed in the large and small-break LOCA analyses per approved methods (Ref. 2). Exceeding the upper temperature limit could result in a higher peak clad temperature, because there is less heat transfer from the core to the injected water following a LOCA. RWST B 3.5.4

BASES

SURVEILLANCE SR 3.5.4.1 REQUIREMENTS The RWST borated water temperature should be verified to be within the limits assumed in the accident analyses band.

The Surveillance Frequency is controlled under the Surveillance Frequency Control Program.

SR 3.5.4.2

The RWST water volume should be verified to be above the required minimum level in order to ensure that a sufficient initial supply is available for injection and to support continued ECCS and Containment Spray System pump operation on recirculation.

The Surveillance Frequency is controlled under the Surveillance Frequency Control Program.

SR 3.5.4.3

The boron concentration of the RWST should be verified to be within the required limits. This SR ensures that the reactor will remain subcritical following a LOCA. Further, it assures that the resulting sump pH will be maintained in an acceptable range so that boron precipitation in the core will not occur and the effect of chloride and caustic stress corrosion on mechanical systems and components will be minimized.

The Surveillance Frequency is controlled under the Surveillance Frequency Control Program.

REFERENCES 1. UFSAR, Chapter 6 and Chapter 15.

2. WCAP-16996-P-A, Revision 1, "Realistic LOCA Evaluation Methodology Applied to the Full Spectrum of Break Sizes (FULL SPECTRUM LOCA Methodology)," November 2016.

SEQUOYAH – UNIT 1 B 3.5.4-5 Revision 45 Containment Pressure B 3.6.4

BASES

APPLICABLE SAFETY ANALYSES (continued)

For certain aspects of transient accident analyses, maximizing the calculated containment pressure is not conservative. In particular, the cooling effectiveness of the Emergency Core Cooling System during the core reflood phase of a LOCA analysis increases with increasing containment backpressure. Therefore, for the reflood phase, the containment backpressure is calculated in a manner designed to conservatively minimize, rather than maximize, the containment pressure WCAP-16996-P-A, response in accordance with 10 CFR 50, Appendix K (Ref. 2). Revision 1 Containment pressure satisfies Criterion 2 of 10 CFR 50.36(c)(2)(ii).

LCO Maintaining containment pressure, relative to the annulus pressure, at less than or equal to the LCO upper pressure limit ensures that, in the event of a DBA, the resultant peak containment accident pressure will remain below the containment design pressure. Maintaining containment pressure, relative to the annulus pressure, at greater than or equal to the LCO lower pressure limit ensures that the containment will not exceed the design negative differential pressure following the inadvertent actuation of the Containment Spray System.

APPLICABILITY In MODES 1, 2, 3, and 4, a DBA could cause a release of radioactive material to containment. Since maintaining containment pressure within limits is essential to ensure initial conditions assumed in the accident analyses are maintained, the LCO is applicable in MODES 1, 2, 3 and 4.

In MODES 5 and 6, the probability and consequences of these events are reduced due to the pressure and temperature limitations of these MODES. Therefore, maintaining containment pressure within the limits of the LCO is not required in MODE 5 or 6.

ACTIONS A.1

When containment pressure is not within the limits of the LCO, it must be restored to within these limits within 1 hour. The Required Action is necessary to return operation to within the bounds of the containment analysis. The 1 hour Completion Time is consistent with the ACTIONS of LCO 3.6.1, "Containment," which requires that containment be restored to OPERABLE status within 1 hour.

SEQUOYAH – UNIT 1 B 3.6.4-2 Revision 45 Containment Pressure B 3.6.4

BASES

ACTIONS (continued)

B.1 and B.2

If containment pressure cannot be restored to within limits within the required Completion Time, the plant must be brought to a MODE in which the LCO does not apply. To achieve this status, the plant must be brought to at least MODE 3 within 6 hours and to MODE 5 within 36 hours. The allowed Completion Times are reasonable, based on operating experience, to reach the required plant conditions from full power conditions in an orderly manner and without challenging plant systems.

SURVEILLANCE SR 3.6.4.1 REQUIREMENTS Verifying that containment pressure is within limits ensures that unit operation remains within the limits assumed in the containment analysis.

The Surveillance Frequency is controlled under the Surveillance Frequency Control Program.

REFERENCES 1. UFSAR, Section 6.2.

2. 10 CFR 50, Appendix K.

WCAP-16996-P-A, Revision 1, "Realistic LOCA Evaluation Methodology Applied to the Full Spectrum of Break Sizes (FULL SPECTRUM LOCA Methodology)," November 2016.

SEQUOYAH – UNIT 1 B 3.6.4-3 Revision 45 Containment Spray System B 3.6.6

BASES

APPLICABLE SAFETY ANALYSES (continued)

The DBA analyses show that the maximum peak containment pressure of 11.44 psig results from the LOCA analysis, and is calculated to be less than the containment design pressure. The basis of the containment design temperature (327°F) is to ensure the OPERABILITY of safety related equipment inside containment (Ref. 3). The maximum peak containment atmosphere temperature of 325.6°F results from the SLB analysis. Therefore, the calculated peak containment atmosphere temperature is acceptable for the DBA SLB.

The modeled containment spray trains actuation from the containment analysis is based on a response time associated with exceeding the High—High containment pressure signal setpoint to achieving full flow through the containment spray train nozzles. A delayed response time initiation provides conservative analyses of peak calculated containment temperature and pressure responses. The containment spray trains total response time of 250 seconds is composed of signal delay, diesel generator startup, and system startup time to full flow through the containment spray train nozzles.

For certain aspects of transient accident analyses, maximizing the calculated containment pressure is not conservative. In particular, the ECCS cooling effectiveness during the core reflood phase of a LOCA analysis increases with increasing containment backpressure. For these calculations, the containment backpressure is calculated in a manner designed to conservatively minimize, rather than maximize, the calculated transient containment pressures in accordance with 10 CFR 50, Appendix K (Ref. 4). WCAP-16996-P-A, Revision 1 Inadvertent actuation of the Containment Spray System is evaluated in the analysis, and the resultant reduction in containment pressure is calculated. The maximum calculated reduction in containment pressure resulted in a containment external pressure load of 0.49 psid, which is below the containment design external pressure load.

The Containment Spray System satisfies Criterion 3 of 10 CFR 50.36(c)(2)(ii).

LCO During a DBA, one subsystem of Containment Spray System is required to provide the heat removal capability assumed in the safety analyses. To ensure that these requirements are met, two containment spray subsystems must be OPERABLE with power from two safety related, independent power supplies.

A containment spray subsystem shall be compromised of one containment spray train and one RHR spray train.

SEQUOYAH – UNIT 1 B 3.6.6-3 Revision 45 Containment Spray System B 3.6.6

BASES

SURVEILLANCE REQUIREMENTS (continued)

SR 3.6.6.8

With the RHR spray train inlet valves closed and the RHR spray header drained of any solution, low pressure air or smoke can be blown through test connections. This SR ensures that each RHR spray nozzle is unobstructed and that spray coverage of the containment during an accident is not degraded.

The Surveillance Frequency is controlled under the Surveillance Frequency Control Program.

REFERENCES 1. 10 CFR 50, Appendix A, GDC 38, GDC 39, and GDC 40.

2. UFSAR, Section 6.2.

3. 10 CFR 50.49.

4. 10 CFR 50, Appendix K.

5. ASME Code for Operation and Maintenance of Nuclear Power Plants.

WCAP-16996-P-A, Revision 1, "Realistic LOCA Evaluation Methodology Applied to the Full Spectrum of Break Sizes (FULL SPECTRUM LOCA Methodology)," November 2016.

SEQUOYAH – UNIT 1 B 3.6.6-7 Revision 45 ARS B 3.6.11

BASES

BACKGROUND (continued)

The ARS is an ESF system. It is designed to ensure that the heat removal capability required during the post accident period can be attained. The operation of the ARS, in conjunction with the ice bed, the Containment Spray System, and the Residual Heat Removal (RHR) System spray, provides the required heat removal capability to limit post accident conditions to less than the containment design values.

APPLICABLE The limiting DBAs considered relative to containment temperature and SAFETY pressure are the loss of coolant accident (LOCA) and the steam line ANALYSES break (SLB). The LOCA and SLB are analyzed using computer codes designed to predict the resultant containment pressure and temperature transients. DBAs are assumed not to occur simultaneously or consecutively. The postulated DBAs are analyzed, in regard to ESF systems, assuming the loss of one ESF bus, which is the worst case single active failure and results in one train each of the Containment Spray System, RHR System, and ARS being inoperable (Ref. 1). The DBA analyses show that the maximum peak containment pressure results from the LOCA analysis and is calculated to be less than the containment design pressure.

For certain aspects of transient accident analyses, maximizing the calculated containment pressure is not conservative. In particular, the cooling effectiveness of the Emergency Core Cooling System during the core reflood phase of a LOCA analysis increases with increasing containment backpressure. For these calculations, the containment backpressure is calculated in a manner designed to conservatively minimize, rather than maximize, the calculated transient containment pressures, in accordance with 10 CFR 50, Appendix K (Ref. 2). WCAP-16996-P-A, The analysis for minimum internal containment pressure (i.e., maximumRevision 1 external differential containment pressure) assumes inadvertent simultaneous actuation of both the ARS and the Containment Spray System. The containment vacuum relief valves are designed to accommodate inadvertent actuation of either or both systems.

The modeled ARS actuation from the containment analysis is based upon a response time associated with exceeding the containment pressure High-High signal setpoint to achieving full ARS air flow. A delayed response time initiation ensures that no energy released during the initial phase of a DBA will bypass the ice bed through the ARS fans. The ARS total response time of 600 seconds consists of the built in signal delay.

The ARS satisfies Criterion 3 of 10 CFR 50.36(c)(2)(ii).

SEQUOYAH – UNIT 1 B 3.6.11-2 Revision 45 ARS B 3.6.11

BASES

SURVEILLANCE REQUIREMENTS (continued)

SR 3.6.11.2

Verifying ARS fan motor current with the return air dampers closed confirms one operating condition of the fan. This test is indicative of overall fan motor performance. Such inservice tests confirm component OPERABILITY, trend performance, and detect incipient failures by indicating abnormal performance.

The Surveillance Frequency is controlled under the Surveillance Frequency Control Program.

SR 3.6.11.3

Verifying the OPERABILITY of the return air damper provides assurance that the proper flow path will exist when the fan is started. By applying the correct counterweight, the damper operation can be confirmed.

The Surveillance Frequency is controlled under the Surveillance Frequency Control Program

REFERENCES 1. UFSAR, Section 6.2.

2. 10 CFR 50, Appendix K.

WCAP-16996-P-A, Revision 1, "Realistic LOCA Evaluation Methodology Applied to the Full Spectrum of Break Sizes (FULL SPECTRUM LOCA Methodology)," November 2016.

SEQUOYAH – UNIT 1 B 3.6.11-4 Revision 45 Ice Bed B 3.6.12

BASES

BACKGROUND (continued)

Both of these degrading phenomena are reduced by minimizing air leakage into and out of the ice condenser.

The ice bed limits the temperature and pressure that could be expected following a DBA, thus limiting leakage of fission product radioactivity from containment to the environment.

APPLICABLE The limiting DBAs considered relative to containment temperature and SAFETY pressure are the loss of coolant accident (LOCA) and the steam line ANALYSES break (SLB). The LOCA and SLB are analyzed using computer codes designed to predict the resultant containment pressure and temperature transients. DBAs are not assumed to occur simultaneously or consecutively.

Although the ice condenser is a passive system that requires no electrical power to perform its function, the Containment Spray System and the ARS also function to assist the ice bed in limiting pressures and temperatures. Therefore, the postulated DBAs are analyzed in regards to containment Engineered Safety Feature (ESF) systems, assuming the loss of one ESF bus, which is the worst case single active failure and results in one train of the Containment Spray System and one ARS fan being inoperable.

The limiting DBA analyses (Ref. 1) show that the maximum peak containment pressure results from the LOCA analysis and is calculated to be less than the containment design pressure. For certain aspects of the transient accident analyses, maximizing the calculated containment pressure is not conservative. In particular, the cooling effectiveness of the ECCS during the core reflood phase of a LOCA analysis increases with increasing containment backpressure. For these calculations, the containment backpressure is calculated in a manner designed to conservatively minimize, rather than maximize, the calculated transient containment pressures, in accordance with 10 CFR 50, Appendix K (Ref. 2). WCAP-16996-P-A, Revision 1 The maximum peak containment atmosphere temperature results from the SLB analysis and is discussed in the Bases for LCO 3.6.5, "Containment Air Temperature."

In addition to calculating the overall peak containment pressures, the DBA analyses include calculation of the transient differential pressures that occur across subcompartment walls during the initial blowdown phase of the accident transient. The internal containment walls and structures are designed to withstand these local transient pressure differentials for the limiting DBAs.

SEQUOYAH – UNIT 1 B 3.6.12-3 Revision 45 Ice Bed B 3.6.12

BASES

SURVEILLANCE REQUIREMENTS (continued)

thickness of the basket walls relative to corrosion rates expected in their services environment and the results of the long term ice storage testing.

SR 3.6.12.6

This SR ensures that initial ice fill and any subsequent ice additions meet the boron concentration and pH requirements of SR 3.6.12.4. The SR is modified by a Note that allows the chemical analysis to be performed on either the liquid or resulting ice of each sodium tetraborate solution prepared. If ice is obtained from offsite sources, then chemical analysis data must be obtained for the ice supplied.

REFERENCES 1. UFSAR, Section 6.2.

2. 10 CFR 50, Appendix K.

3. Sequoyah Nuclear Plant Units 1 and 2 – Nuclear Steam Supply System Engineering Support Services – Contract 99NAN-251787 – Letter N9873, Contract Work Authorization N20000 020 – Production Core – Post Loss of Coolant Accident (LOCA) Long Term Core Cooling Analysis – N2N 058, dated August 13, 2001.

WCAP-16996-P-A, Revision 1, "Realistic LOCA Evaluation Methodology Applied to the Full Spectrum of Break Sizes (FULL SPECTRUM LOCA Methodology)," November 2016.

SEQUOYAH – UNIT 1 B 3.6.12-8 Revision 45 Ice Condenser Doors B 3.6.13

BASES

APPLICABLE SAFETY ANALYSES (continued)

the ECCS during the core reflood phase of a LOCA analysis increases with increasing containment backpressure. For these calculations, the containment backpressure is calculated in a manner designed to conservatively minimize, rather than maximize, the calculated transient containment pressures, in accordance with 10 CFR 50, Appendix K (Ref. 2). WCAP-16996-P-A, Revision 1 The maximum peak containment atmosphere temperature results from the SLB analysis and is discussed in the Bases for LCO 3.6.5, "Containment Air Temperature."

An additional design requirement was imposed on the ice condenser door design for a small break accident in which the flow of heated air and steam is not sufficient to fully open the doors.

For this situation, the doors are designed so that all of the doors would partially open by approximately the same amount. Thus, the partially opened doors would modulate the flow so that each ice bay would receive an approximately equal fraction of the total flow.

This design feature ensures that the heated air and steam will not flow preferentially to some ice bays and deplete the ice there without utilizing the ice in the other bays.

In addition to calculating the overall peak containment pressures, the DBA analyses include the calculation of the transient differential pressures that would occur across subcompartment walls during the initial blowdown phase of the accident transient. The internal containment walls and structures are designed to withstand the local transient pressure differentials for the limiting DBAs.

The ice condenser doors satisfy Criterion 3 of 10 CFR 50.36(c)(2)(ii).

LCO This LCO establishes the minimum equipment requirements to assure that the ice condenser doors perform their safety function. The ice condenser inlet doors, intermediate deck doors, and top deck doors must be closed to minimize air leakage into and out of the ice condenser, with its attendant leakage of heat into the ice condenser and loss of ice through melting and sublimation. The doors must be OPERABLE to ensure the proper opening of the ice condenser in the event of a DBA. OPERABILITY includes being free of any obstructions that would limit their opening, and for the inlet doors, being adjusted such that the opening and closing torques are within limits. The ice condenser doors function with the ice condenser to limit the pressure and temperature that could be expected following a DBA.

SEQUOYAH – UNIT 1 B 3.6.13-3 Revision 45 Ice Condenser Doors B 3.6.13

BASES

SURVEILLANCE REQUIREMENTS (continued)

steam and water mixture entering the lower compartment does not pass through part of the ice condenser, depleting the ice there, while bypassing the ice in other bays.

The Surveillance Frequency is controlled under the Surveillance Frequency Control Program.

SR 3.6.13.6

Verifying the OPERABILITY of the intermediate deck doors provides assurance that the intermediate deck doors are free to open in the event of a DBA. The verification consists of visually inspecting the intermediate doors for structural deterioration, verifying free movement of the vent assemblies, and ascertaining free movement of each door when lifted with the applicable force shown below:

Door Lifting Force

a. 0-1, 0-5 ” 37.4 lb

b. 0-2, 0-6 ” 33.8 lb

c. 0-3, 0-7 ” 31.0 lb

d. 0-4, 0-8 ” 31.8 lb

The Surveillance Frequency is controlled under the Surveillance Frequency Control Program.

SR 3.6.13.7

Verifying, by visual inspection, that the top deck doors are in place, closed, and not obstructed provides assurance that the doors are performing their function of keeping warm air out of the ice condenser during normal operation, and would not be obstructed if called upon to open in response to a DBA.

The Surveillance Frequency is controlled under the Surveillance Frequency Control Program.

REFERENCES 1. UFSAR, Chapter 6.

2. 10 CFR 50, Appendix K.

WCAP-16996-P-A, Revision 1, "Realistic LOCA Evaluation Methodology Applied to the Full Spectrum of Break Sizes (FULL SPECTRUM LOCA Methodology)," November 2016.

SEQUOYAH – UNIT 1 B 3.6.13-7 Revision 45 MSSVs B 3.7.1

BASES

APPLICABLE SAFETY ANALYSES (continued)

In addition to the decreased heat removal events, reactivity insertion events may also challenge the relieving capacity of the MSSVs. The UFSAR, Section 15.2.2 (Ref. 7) safety analysis of the uncontrolled rod cluster control assembly (RCCA) bank withdrawal at power event is characterized by an increase in core power and steam generation rate until reactor trip occurs when the Overtemperature ¨T, OverpRZHUǻ7 High Pressurizer Pressure, High Pressurizer Water Level, or Power Range Neutron Flux-High setpoint is reached. Steam flow to the turbine will not increase from its initial value for this event. The increased heat transfer to the secondary side causes an increase in steam pressure and may result in opening of the MSSVs prior to reactor trip, assuming no credit for operation of the atmospheric relief or condenser steam dump valves. The analysis of the RCCA bank withdrawal (Reference 8) at power slow event demonstrates that the MSSVs are capable of preventing secondary side overpressurization for this AOO.

The UFSAR safety analyses discussed above assume that all of the MSSVs for each steam generator are OPERABLE. If there are inoperable MSSV(s), it is necessary to limit the primary system power during steady-state operation and AOOs to a value that does not result in exceeding the combined steam flow capacity of the turbine (if available) and the remaining OPERABLE MSSVs. The required limitation on primary system power necessary to prevent secondary system overpressurization may be determined by system transient analyses or conservatively arrived at by a simple heat balance calculation. In some circumstances it is necessary to limit the primary side heat generation that can be achieved during an AOO by reducing the setpoint of the Power Range Neutron Flux-High reactor trip function.

The MSSVs satisfy Criterion 3 of 10 CFR 50.36(c)(2)(ii).

LCO The accident analysis requires that five MSSVs per steam generator be OPERABLE to provide overpressure protection for design basis transients occurring at 102% RTP. The LCO requires that five MSSVs per steam generator be OPERABLE in compliance with Reference 2, and the DBA analysis.

The OPERABILITY of the MSSVs is defined as the ability to open upon demand within the setpoint tolerances, to relieve steam generator overpressure, and reseat when pressure has been reduced. The OPERABILITY of the MSSVs is determined by periodic surveillance testing in accordance with the Inservice Testing Program.

This LCO provides assurance that the MSSVs will perform their designed safety functions to mitigate the consequences of accidents that could result in a challenge to the RCPB, or Main Steam System integrity.

SEQUOYAH – UNIT 1 B 3.7.1-2 Revision 45 MSSVs B 3.7.1

BASES

SURVEILLANCE REQUIREMENTS (continued)

tested or tested in situ at hot conditions using an assist device to simulate lift pressure. If the MSSVs are not tested at hot conditions, the lift setting pressure shall be corrected to ambient conditions of the valve at operating temperature and pressure.

REFERENCES 1. UFSAR, Section 10.3.2.

2. ASME, Boiler and Pressure Vessel Code, Section III, dated 1968, and March 1970 Addenda.

3. UFSAR, Section 15.2.7.

4. ASME Code for Operation and Maintenance of Nuclear Power Plants.

5. ANSI/ASME OM-1-2001 through 2003 Addenda.

6. NRC Information Notice 94-60, "Potential Overpressurization of the Main Steam System," August 22, 1994.

7. UFSAR, Section 15.2.2.

8. AREVA Document 51-5006459-00, “SQN Uncontrolled RCCA Withdrawal Accident Analysis Profile.“

SEQUOYAH – UNIT 1 B 3.7.1-5 Revision 45 Enclosure 1

Evaluation of the Transition to Westinghouse RFA-2 Fuel

ATTACHMENT 6

Revised Core Operating Limits Report (COLR) Template for Units 1 and 2 (For Information Only)

CNL-20-014 TEMPLATE - SEQUOYAH NUCLEARLEARLEA PLANT,PLANT, UNITNIT 11/2,/2/ CYCLE 26

CORE OPERATINGRATINGATING LIMITS REPORREPORT

Month Year

TEMPLATE

1.0 CORE OPERATING LIMITS REPORT

This Core Operating Limits Report (COLR) for Sequoyah Nuclear Plant Unit 1/2 has been prepared in accordance with the requirements of the Technical Specifications (TS) 5.6.3.

The Technical Specifications affected by this report are listed below:

TS COLROLR COLRCOLO Section Technical Specification COLR Parameter Section Page 2.1.1 Reactor Core Safety Limits 2.1 3 2.2.1 3 3.1.1 SHUTDOWN MARGIN (SDM) SDM 2.2.22.2 3 BOL MTC Limit 2.3.1 4 Moderator Temperature Coefficient EOL MTC Limit 2.3.1 4 3.1.3 (MTC) 300 ppm Surveillancee Limitimit 2.3.22. 4 60 ppm Surveillancence Limit 2.3.3 E4 3.1.4 Rod Group Alignment Limits SDM 2.22.2.3 3 Shutdown Bankanknk Insertion Limits 2.4 4 3.1.5 Shutdown Bank Insertion Limits SDM 2.2.4 3 Controll Bank Insertionertion Limits TTE2.5 4 3.1.6 Control Bank Insertion Limits SDMM 2.2.5 3 PHYSICS TESTS Exceptions – 3.1.8 SDM 2.2.6 3 MODE 2 RTP FQ 2.6.1 5 K(Z) AT2.6.2 5 W FQ (Z) 2.6.3 5 Heat Flux Hot Channel Factoractor [T(Z)][T( COLRR 2.6.4 5 3.2.1 (FQ(Z)) Axy(Z)(Z) FactFactor 2.6.5 5 Rj PenaltyPenal LAFactor 2.6.6 5 ThermalThermThe Power Limits 2.6.7 6 UFQ 2.6.8 6

Nuclear Enthalpynthalpy Rise Hot Channel N 3.2.2 N F'H 2.7 6 Factor (FF'H ) P 3.2.3 Axialal Flux Difference (AFD) AFD Limits 2.8 6 Overtemperature ¨T Trip Setpoints 2.9.1 7 Reactor Trip System (RTS)(RTS(RT Overpower ¨T Trip Setpoints 2.9.2 7 3.3.1 Instrumentation QTNL, QTPL, QTNS, and QTPS 2.9.3 7 QPNL, QPPL, QPNS, and QPPS 2.9.4 8 RCS Pressure, TeTemperature,MPM and Pressurizer pressure 3.4.1 Flowow DepartureDepartur from Nucleate RCS average temperature 2.10 8 Boilingng (DNB)(DN Limits RCS flow 3.9.1 Boron ConcentrationCo Refueling Boron Concentration 2.11 8 CORECO OPERATINGEM LIMITS 5.6.36.3 Analytical Methods Table 1 13 TEMPLATETETREPORTRE (COLR)

Unit 1/2 Cycle 26 SEQUOYAH Page 2 of 19 Revision 0

2.0 OPERATING LIMITS

The cycle-specific parameter limits for the specifications listed in Section 1.0 are presented in the following subsections. These limits have been developed using the NRC approved methodologies specified in the Technical Specifications 5.6.3.

The following abbreviations are used in this section:

BOL -- Beginning of Cycle Life ARO -- All Rods Out HZP -- Hot Zero Thermal Power EOL -- End of Cycle Life RTP -- Rated Thermal Power RCS -- Reactor Coolant System RAOC -- Relaxed Axial Offset Control ROS -- RAOC Operating Space SFCP -- Surveillance Frequency Control Programgram

2.1 REACTOR CORE SAFETY LIMITS (Safety Limit 2.1.1).1)

In MODES 1 and 2, the combination of THERMALERMAL POWER, ReactReactor Coolant System (RCS) highest loop average temperature, and pressurizer pressure shshall not exceed the limits in Figure 1.

2.2 SHUTDOWN MARGIN (LCOLCO 3.1.13.1.1,, 3.1.4, 3.1.5, 33.1.6, 3.1.8)

2.2.1 For TS 3.1.16'0VKDOOEH•ǻ6'0VKDOOEH•0VKDOOEH• ǻk/k in MODE 2 with keff < 1.0, MODEMO 3 anand MODE 4.

2.2.2 For TSS 3.1.13.1.1.16'0VKDOOEH•00% ǻk/k in MODE 5.

2.2.33 For TS 3.1.43.1.46'0VKDOO6'0VKDOOEH•ǻk/k in MODE 1 and MODEMOD 2.

2.2.42.2.4 )RU766')RU766'0VKDOOEH•ǻk/k in MODE 1 anda MODE 2.

2.2.52.2.5 )RU76)RU766'0VKDOOEH•ǻk/k in MODEM 1 and MODE 2 with keff • 1.0.

2.2.62.2.6 For TS 3.1.86'0VKDOOEH•ǻk/k TEMPLATE in MODE 2.

Unit 1/2 Cycle 26 SEQUOYAH Page 3 of 19 Revision 0

2.3 MODERATOR TEMPERATURE COEFFICIENT - MTC (LCO 3.1.3)

2.3.1 The Moderator Temperature Coefficient (MTC) limits are:

The BOL/ARO/HZP - MTC shall be less positive than 0 'k/k/qF (upper limit).

The EOL/ARO/RTP - MTC shall be less negative than or equal to -4.29 x 10-5 'k/k/qF (lower limit).

2.3.2 The 300 ppm surveillance limit is:

The measured 300 ppm /ARO/RTP-MTC should be less negative than or equal to -3.39 x 10-4 'k/k/qF.

2.3.3 The 60 ppm surveillance limit is:

The measured 60 ppm /ARO/RTP-MTC shoulduld be lessless negative than or equale to -4.04 x 10-4 'k/k/qF.

2.4 SHUTDOWN BANK INSERTION LIMITS (LCOLCO 3.1.3.1.5)5))

2.4.1 The shutdown banks shall be withdrawn to a position greagre ter than or equal to 225 steps withdrawn.

2.5 CONTROL BANK INSERTIONN LIMITS (LCO 3.1.3.1.6)6)

2.5.1 The control banksks are fully withdrawn or shshall be limited in physical insertion as shown in Figureureur 2.2

2.5.2 Each controlntroltrol bank shall be considereconsidconsidered fully withdrawn from the core at greater than or equall to 225 steps.

2.5.3 The control banks shall be ooperated in sequence by withdrawal of Bank A, Bank B, Bank C, and Bank D.D Th The control banks shall be sequenced in reverse order upon insertion.

2.22.5.45.4 Each control bankba not fully withdrawn from the core shall be operated with the following overlapoov as a function of park position.

Park Position (step(steps) Bank Overlap (steps) Bank Difference Tip-to- Tip Separation (steps) 225 5 97 128 22622 98 128 227 99 128 228 100 128 229 101 128 230 102 128 TEMPLATE 231 103 128

Unit 1/2 Cycle 26 SEQUOYAH Page 4 of 19 Revision 0

2.6 HEAT FLUX HOT CHANNEL FACTOR - FQ(Z) (LCO 3.2.1)

ܨோ்௉ 0.5 < ܲ ݎ݋݂ (ܼ)ܭכ ஼(ܼ) ൑ ொܨ ொ ܲ

ܨோ்௉ ൑0.5ܲ ݎ݋݂ (ܼ)ܭכ ஼(ܼ) ൑ ொܨ ொ 0.5

where: ஼ ெ Uிொ כ (ܼ) ொܨ = (ܼ) ொܨ

ܶܪܧܴܯܣܮ ܱܹܲܧܴ ܲ = ܴܣܶܧܦ ܶܪܧܴܯܣܮ ܱܹܲܧܴ

ோ்௉ 2.6.1 ܨொ = 2.62

2.6.2 K(Z) is provided in Figure 3.

2.6.3 ܨோ்௉ 0.50.5< ܲ ݎ݋݂ (ܼ)ܭכ ௐ(ܼ) ൑ ொܨ ொ ܲ

ܨோ்௉ ൑0.5ܲ ݎ݋݂ (ܼ)ܭכ ௐ(ܼ) ൑ ொܨ ொ 0.5

where: [்(௓)]಴ೀಽೃ U כ ܴכ (ܼ) ܣכ כ ெ[[(ܼ) ܨ] = (ܼ)ௐܨ ொ ௑௒ ௌ௨௥௩ ௉ ௑௒ ௝ ிொ

ெ and, [ܨ௑௒௒(ܼ)]ௌ௨௥௩ is theth P mmeasured planar radial peaking factor. 2.6.46.4

[ܶ(ܼ)]஼ை௅ோ஼ை௅஼ை ோ valuesalues are pprovided in Tables 2 and 3 for Relaxed Axial Offset Control ((RAOC)RAOC) operating spspace one (ROS1) and RAOC operating space two (ROS2).

22.6.5.6.5

TThehe ܣ௑௒(ܼ) factors adjust the surveillance to the reference conditions assumed in ஼ை௅ோ generatinggenera the [ܶ(ܼ)] factors. ܣ௑௒(ܼ) may be assumed to equal 1.0 or may be detedetermined for specific surveillance conditions using the approved methods listed in TS 55.6.3.

2.6.6

TEMPLATEThe ܴ penalty factors account for the potential decrease in transient FQ margin between ௝ surveillances. The ܴ௝ factors for ROS1 and ROS2 are provided in Tables 4 and 5 respectively.

Unit 1/2 Cycle 26 SEQUOYAH Page 5 of 19 Revision 0

2.6.7

Table 6 provides the required limits on THERMAL POWER and the required AFD reductions for each ROS in the event that additional margin is required.

2.6.8

The uncertainty, UFQ, to be applied to measured FQ(Z) shall be calculated by thehe following:

UFQ = Uqu * Ue

where:

Uqu = Base FQ measurement uncertainty = 1.05 whenhenn PDMS is inoperableinopera (Uqu is defined by PDMS when OPERABLE)BLE) Ue = Engineering uncertainty factor = 1.03

N 2.7 NUCLEAR ENTHALPY RISE HOT CHANNEL FACTORCTOR – F'H (LCO 33.2.2)

N RTP F'H * U¨+ d F'H * ( 1 + PF¨+ * ( 1-P))))

where P = Thermal Power / Rated Thermal PPower

RTP F'H = 1.70 for RFA-2 fuel,el, and 1.61.611 for HTP fuel AT

PF¨+ = 0.3

N The uncertainty, U¨+, to be applied tot measumeasured F¨+ shall be 1.04 when PDMS is inoperable (U¨++ is defined by PDMS whenwhew OPERABLE).

2.8 AXIAL FLUXX DIFFERENCE - AFD (L(LCO 3.2.3)

The AFDD limits for Cycle 26 are proprovided in Figure 4.

TEMPLATE

Unit 1/2 Cycle 26 SEQUOYAH Page 6 of 19 Revision 0

2.9 REACTOR TRIP SYSTEM (RTS) INSTRUMENTATION (LCO 3.3.1)

2.9.1 Overtemperature ¨T Trip Setpoints

Parameter Value Overtemperature ¨T reactor trip setpoint K1 ” 1.15 Overtemperature ¨T reactor trip setpoint Tavg coefficient K2 • 0.015/°F Overtemperature ¨T reactor trip setpoint pressure coefficient K3 = 0.0008/psig Nominal Tavg at RTP T' ” 578.2°F Nominal RCS operating pressure P' = 2235 psigig Measured RCS ¨T lead/lag time constants IJ4 • 5 sec IJ5 ” 3 secec Measured RCS average temperature lead/lag time constants IJ1 • 33 sec IJ2 ” 4 sec

2.9.2 Overpower ¨T Trip Setpoints

Parameter Value Overpower ¨T reactor trip setpoint K 4 ” 1.087 Overpower ¨T reactor trip setpoint Tavg rate/lag coefficientoefficientt K 5 • 0.020.02/°F/°F for increasing Tavg 0/°F0 for decreasing Tavg ” Overpower ¨T reactor trip setpoint Tavg heatuptup coefficient K 6 • 00.0011/°F when T > T 0/°F when T ” T” Nominal Tavg at RTP T" ” 578.2°F Measured RCS ¨T lead/lag time constantsonstants ATIJ4 •5 sec IJ5 ”3 sec Measured RCS average temperatureerature rate/lag time constanconstant IJ3 •10 sec

2.9.3 Trip Reset Termm [ff1 ǻ, @IRU2YHUWHPSHUDWXUH¨ ǻ, @IRU2YHUWHPSHUDWX ǻ, @IRU2YHUW T Trip

The followingingg parameters are required tot specify the power level-dependent f1 ǻ, WULSUHVHW term limitsitsit for TS Table 3.33.3.13.3.1--1 (function(fun 6), Overtemperature ¨T trip function: 2.9.3.13.1 QTNL = --20%20% where QTNL = WKHWWKH PD[LPXP QHJDWLYH ǻ, VHWSRLQW DW 5$7(' 7+(50$/ POWER at which the trip setpoint is not reduced by the axial power distribution. 2.2.9.3.29.3.2 QTPL = +5%+ wherwhere QTPL = WKH PD[LPXP SRVLWLYH ǻ, VHWSRLQW DW 5$7(' 7+(50$/ POWER at which the trip setpoint is not reduced by the axial power distribution. 2.2.9.3.39 QTNS = 2.50% where QTNS = the percent reduction in Overtemperature ¨T trip setpoint for each SHUFHQW WKDW WKH PDJQLWXGH RI ǻ, H[FHHGV LWV QHJDWLYH OLPLW DW RATED THERMAL POWER (QTNL). TEMPLATE2.9.3.4 QTPS = 1.40% where QTPS = the percent reduction in Overtemperature ¨T trip setpoint for each percent that the magnitXGH RI ǻ, H[FHHGV LWV SRVLWLYH OLPLW DW RATED THERMAL POWER (QTPL).

Unit 1/2 Cycle 26 SEQUOYAH Page 7 of 19 Revision 0 2.9.4 Trip Reset Term [f2 ǻ, @IRU2YHUSRZHU¨T Trip

The following parameters are required to specify the power level-dependent f2 ǻ, WULSUHVHW term limits for TS Table 3.3.1-1 (function 7), Overpower ¨T trip function: 2.9.4.1 QPNL = % where QPNL = WKH PD[LPXP QHJDWLYH ǻ, VHWSRLQW DW 5$7(' 7+(50$/ POWER at which the trip setpoint is not reduced by the axial power distribution. 2.9.4.2 QPPL = % where QPPL = the maximum SRVLWLYH ǻ, VHWSRLQW DWW 5$7(' 7+(50$/ POWER at which the trip setpoint iss not reduced by the axial power distribution. 2.9.4.3 QPNS = % where QPNS = the percent reduction in Overpowerrpow ¨T trip sesetpoinsetpoint for each SHUFHQW WKDW WKH PDJQLWXGHWXGHWXG RI ǻ, exceedsds its negativeneg limit at RATED THERMAL POWER (QPNL).(Q 2.9.4.4 QPPS = % where QPPS = the percent reductioneduction inn Overpower ¨T triptr setpoint for each SHUFHQWWKDWWKHPDJQLWXGHRIDWWKHPDJQLWXGHRIǻ,H[FHHGHRIǻ,Hǻ,H[FHHGVLWVSRVLWLYHOLPLWDW RATEDD THERMAL POWER (Q(QPPL).P

2.10 RCS PRESSURE, TEMPERATURE,URE, AND FLOW DEPARTUREDEPA FROM NUCLEATE BOILING (DNB) LIMITS (LCOCO 3.3.4.1)4.1)

Parameter Indicated Value

Pressurizer pressure •2220 psia

RCS average temperatureerature ”583ၨ)

RCS floww •378,400 gpm

2.11 REFUELINGEFUELING BORON CONCENTRATIONCON (LCO 3.9.1)

The refueling boron concentrationcon shall be t 1824 ppm. TEMPLATE

Unit 1/2 Cycle 26 SEQUOYAH Page 8 of 19 Revision 0

680

UNACCEPTABLE 660 OPERATION

2465 psia

640 2250 psia E 620

2000 psia

1860 psia 600 Temperature (°F) AT ACCEPTABLE 580 OPERATION LAT 560 PLA

540 00. 0.2 0.4 0.6 0.8 1 1.2

MPLATE Fraction of Rated Thermal Power

EMPLATEEM Figure 1 Reactor Core Safety Limits TETEMPLATERCS T-avg Versus Rated Thermal Power

Unit 1/2 Cycle 26 SEQUOYAH Page 9 of 19 Revision 0

E

Fraction of Rated Thermal Power

Figure 2 Control Bank Insertion Limits Versus Rated Thermal Power MPFour Loop Operation Note: the above control bankba insertion limits are applicable to both ROS1 and ROS2.

* Fully withdrawn region shall be the condition where shutdown and control banks are at a position within the intinterval of t 225 and d 231 steps withdrawn. TEMP

Unit 1/2 Cycle 26 SEQUOYAH Page 10 of 19 Revision 0

1.2

1.1

1

0.9

0.8

0.7 Power Q* 0.6 Core Height K(Z) 0.000 1.000 TE 6.000 1.0001 0.5 12.000 1.0001 Normalized F Normalized

0.4 ATEAT

0.3 LAT

0.2

0.1

0 01234567891011120 1 2 Core Height (feet)

Figure 3 EMPLAEMEK(Z) - Normalized FQ(Z) as a Function of Core Height TETEM

Unit 1/2 Cycle 26 SEQUOYAH Page 11 of 19 Revision 0

120 Unacceptable Operation

100

80

60 Acceptable ROS 1 Operation ROSE 2 % of Rated Thermal Power 40 TET 20 AT 0 -50 -40 -30 -20-10 010 20 30 40 Axial Flux DifferenceDiffere (ȴI) % LATEL

RAOC OOperatingperaterat RAOC Operating Power SSpacepace OOnenen (ROS1) Space Two (ROS2) (% RTP) AFD LLimitPLP (%) AFD Limit (%) 50 -40 -37 100 -13 -10 100 7 4 50 MMPMPLATE28 25 Figure 4 Axialal FluFlux Difference (AFD) Acceptable Operation Limits as a function of EME Rated Thermal Power (RAOC) TEMP

Unit 1/2 Cycle 26 SEQUOYAH Page 12 of 19 Revision 0

Table 1 COLR Methodology Topical Reports

1. WCAP-8745-P-$³'HVLJQ%DVHVIRUWKH7KHUPDO2YHUSRZHU¨7DQG7KHUPDO2YHUWHPSHUDWXUH ¨77ULS)XQFWLRQV´6HSWHPEHU PHWKRGRORJ\IRU27¨7DQG23¨75HDFWRU7ULS6\VWHPVHWSRLQWVLQ76 

2. WCAP-9272-P-A, “Westinghouse Reload Safety Evaluation Methodology,” July 1985.985. (methodology for Shutdown Margin, Moderator Temperature Coefficient, Shutdownown Bank Insertion Limit, Control Bank Insertion Limits, Axial Flux Difference, Heat Fluxluxx Hot Channel Factor, Nuclear Enthalpy Rise Hot Channel Factor, DNB Limits, Refuelingg Pool Boron Concentration)

3. WCAP-10216-P-A, Revision 1A, “Relaxation of Constant Axial Offset Control – FQ SurveillanceSurveillaeilla Technical Specification,” February 1994. (methodology for Axial Flux Difference limits with Relaxed Axial Offset Control and HHeat Flux Hot Channel Factor (W(z)) Surveillance Requirements forr FQ)

4. WCAP-10444-P-A, “Reference Core Report VANTAGEAGE 5 FFueluel Assembly,” SepSSeptember 1985. (methodology for Axial Flux Difference and Heatt Flux Hott Channel Factor Limits)L

5. WCAP-10444-P-A Addendum 2-A, “VANTAGETAGE 5H Fuel AssemblyAssembly,” February 1989. (methodology for Axial Flux Difference andand Heat Flux Hot Channel Factor Limits)

6. WCAP-10965-P-A, “ANC: A Westinghousetinghouse Advanced Nodal Computer Code,” September 1986. (methodology for Shutdown Margin,argin, ModeratorModerator TemperaturTemperature Coefficient, Shutdown Bank Insertion Limit, Control Bankk Insertion Limits, AxialAxial FluxFlu Difference, Heat Flux Hot Channel Factor, Nuclear Enthalpy Risese Hot Channel Factor,FFactor, ReRefueling Pool Boron Concentration)

7. WCAP-10965-P-A, Addendum 22-A,-A, RevisioRevision 0, “Qualification of the New Pin Power Recovery Methodology,” Septembereptembermber 2010. (methodology for Shutdown Margin, ModeratoMode r Temperature Coefficient, Shutdown Bank Insertion Limit,mit, Control Bank Insertion Limits, Heat Flux Hot Channel Factor, Nuclear Enthalpy Rise Hot Channel Factor, Axial Flux Difference, TS 3.4.1 DNB Limits, Refueling Pool Boron Concentration)ntration)ntratio

8. WCWCAP-11397-P-A,AP-11397397-P-A, “Revised“Revise Thermal Design Procedure,” April 1989. (methodology for Reactor Core Safety Limits, Nuclear Enthalpy Rise Hot Channel Factor, TS 3.4.1 DNB Limits)

9. WCAPWCAP-12610-P-A,-12610-P “VANTAGE+ Fuel Assembly Reference Core Report,” April 1995. (methodology for Axial Flux Difference and Heat Flux Hot Channel Factor Limits)

10.0. WCAPWCAP-12610-P-A & CENPD-404-P-A, Addendum 1-A, “Optimized ZIRLOTM,” July 2006. (meth(methodology for Axial Flux Difference and Heat Flux Hot Channel Factor Limits)

11.1 WCAP-14565-P-A, “VIPRE-01 Modeling and Qualification for Pressurized Water Reactor Non- TEMPLATELOCA Thermal-Hydraulic Safety Analysis,” October 1999. (methodology for DNB Safety Limit, Nuclear Enthalpy Rise Hot Channel Factor, and TS 3.4.1 DNB Limits)

Unit 1/2 Cycle 26 SEQUOYAH Page 13 of 19 Revision 0

12. WCAP-14565-P-A, Addendum 1-A, Revision 0, “Addendum 1 to WCAP 14565-P-A Qualification of ABB-NV Critical Heat Flux Correlations with VIPRE-01 Code,” August 2004. (methodology for DNB Safety Limit)

13. WCAP-14565-P-A, Addendum 2-P-A, Revision 0, “Addendum 2 to WCAP-14565-P-A Extended Application of ABB-NV Correlation and Modified ABB-NV Correlation WLOP for PWRR Low Pressure Applications,” April 2008. (methodology for DNB Safety Limit)

14. WCAP-15025-P-A, “Modified WRB-2 Correlation, WRB-2M, for Predicting Criticalritical Heat Flux in 17x17 Rod Bundles with Modified LPD Mixing Vane Grids,” April 1999.9. (methodology for DNB Safety Limit and Nuclear Enthalpy Rise Hot Channelannel Factor)

15. WCAP-16045-P-A, “Qualification of the Two-Dimensional Transportport Code PARAGON,” August 2004. (methodology for Shutdown Margin, Moderator Temperaturee Coefficient, Shutdown BanBBank Insertion Limit, Control Bank Insertion Limits, Heat Flux Hot Channel Factor, NucleaNuclear Enthalpy Rise Hot Channel Factor, Axial Flux Difference, TS 3.4.14.11 DNB Limits, ReRefueling PPool Boron Concentration)

16. WCAP-16045-P-A, Addendum 1-A, “Qualificationation of the NEXUSEXUS NuNucleaNuclear Data Methodology,” August 2007. (methodology for Moderator Temperatureree CoefficCoefficient)

17. WCAP-16996-P-A, Revision 1, “RealisticRealistic LOCA Evaluation MethodologyM Applied to the Full Spectrum of Break Sizes (FULLL SPECTRUM LOCA MethoMethodology),” November 2016. N (methodology for FQ and F ¨++ limits)

18. WCAP-17661-P-A, Revisionvision 1, "Improved"Improve RAOC and CAOC FQ Surveillance Technical Specifications," Februaryruaryuary 2019. (methodology for controltrol bank insertion limitlimits, FQ limits, and AFD limits)

TEMPLATE

Unit 1/2 Cycle 26 SEQUOYAH Page 14 of 19 Revision 0

Table 2 [T(Z)]COLR Factors for ROS1

Elevation 12000 Point (ft) 150 MWD/MTU 4000 MWD/MTU MWD/MTU 20000 MWD/MTU 6 11.1 1.0894 1.0350 1.1758 1.2626 7 10.9 1.1325 1.0953 1.2406 1.2932932 8 10.7 1.1657 1.1456 1.2870 1.3122.3122 9 10.5 1.1912 1.1832 1.3205 1.3193 10 10.3 1.2093 1.2271 1.3390 1.31741.31 11 10.1 1.2279 1.2673 1.3544 1.3132 12 9.9 1.2448 1.2993 1.3666 1.3067 13 9.7 1.2574 1.3224 1.3742 1.2981 14 9.5 1.2647 1.3381 1.3720 1.2890 15 9.3 1.2702 1.3424 1.366262 1.28752875 16 9.1 1.2726 1.3390 1.3513.3513 1.28355 17 8.9 1.2766 1.3338 1.3330 1.2775 18 8.7 1.2876 1.3353 1.3203.320 1.27481.274 19 8.5 1.3026 1.3461 1.3112 1.27281.21 E 20 8.3 1.3132 1.3545 1.3046 1.2730 21 8.1 1.3248 1.3659 1.2964 1.2719 22 7.9 1.3368 1.37866 1.2910 1.2729 23 7.7 1.3445 1.3869869 1.2907 1.2787 24 7.4 1.3491 1.3922 1.2873 TTE1.2834 25 7.2 1.3510 1.3948 1.28201.2 1.2860 26 7.0 1.3498 1.3944 1.27511.2751. 1.2863 27 6.8 1.3459 1.39121 1.26681.2 1.2844 28 6.6 1.3396 1.38551.38 1.2570 1.2801 29 6.4 1.3318 1.3789 1.2458 1.2735 30 6.2 1.32277 1.3731 ATA1.2336 1.2647 31 6.0 1.31103110 1.3680 1.2208 1.2528 32 5.8 1.2996 1.3642642 1.2129 1.2418 33 5.6 1.2914 1.3628 1.2149 1.2363 34 5.4 1.2854 1.37441.37 1.2247 1.2350 35 5.2 1.2888888 1.38391 LAL 1.2340 1.2391 36 5.0 1.2952 1.3905 1.2421 1.2435 37 4.8 1.29971.299 1.3953 1.2502 1.2462 38 4.66 1.3032 1.3977 1.2588 1.2477 39 4.4 1.3054.3054 1.3978 1.2682 1.2480 40 4.2 1.3061 PLP1.3954 1.2772 1.2473 41 4.0 1.30531.3 1.3906 1.2856 1.2457 42 3.88 1.30321.30 1.3826 1.2934 1.2434 43 3.63 1.30091 1.3728 1.3004 1.2426 44 3.4 1.2995 1.3646 1.3084 1.2465 455 3.23. 1.2966 1.3564 1.3174 1.2503 46 3.0 1.2938 1.3487 1.3275 1.2615 47 2.8 MPM1.2978 1.3393 1.3434 1.2798 48 2.6 1.3087 1.3298 1.3649 1.3079 49 2.4 1.3158 1.3246 1.3821 1.3352 50 2.22 1.3203 1.3145 1.3955 1.3625 51 2.0 1.3220 1.2984 1.4039 1.3896 52 1.8 1.3203 1.2767 1.4055 1.4147 53 EME1.6 1.3147 1.2481 1.3983 1.4360 544 1.4 1.3040 1.2117 1.3796 1.4501 55 1.2 1.2864 1.1665 1.3462 1.4519 56 1.0 1.2588 1.1098 1.2931 1.4330 Note: 1. AxialTTEMPLATETE points 1-5 and 57-61 are excluded. Also, axial points within ±2% of the active core height of a grid location or a bank demand position are excluded.

Unit 1/2 Cycle 26 SEQUOYAH Page 15 of 19 Revision 0

Table 3 [T(Z)]COLR Factors for ROS2

Elevation 12000 Point (ft) 150 MWD/MTU 4000 MWD/MTU MWD/MTU 20000 MWD/MTU 6 11.1 1.0128 0.9798 1.1010 1.2220220 7 10.9 1.0555 1.0355 1.1615 1.2494 8 10.7 1.0870 1.0821 1.2046 1.2651 9 10.5 1.1121 1.1175 1.2358 1.2690 10 10.3 1.1318 1.1496 1.2544 1.2625 11 10.1 1.1438 1.1761 1.2607 1.2584 12 9.9 1.1596 1.1932 1.2632 1.2540 13 9.7 1.1825 1.2060 1.26777 1.2493 14 9.5 1.1953 1.2230 1.2685685 1.2425425 15 9.3 1.2038 1.2350 1.2615 1.23011 16 9.1 1.2091 1.2401 1.2490 1.2186 17 8.9 1.2134 1.2480 1.240024 1.20401.20 E 18 8.7 1.2192 1.2604 1.2355 1.19051 19 8.5 1.2305 1.2763 1.23511. 1.1943 20 8.3 1.2428 1.2898 1.2333 1.1999 21 8.1 1.2586 1.30688 1.2353 1.2084 22 7.9 1.2747 1.32523252 1.2391 1.2189 23 7.7 1.2872 1.3396 1.24021.240 TTE1.2270 24 7.4 1.2973 1.3515 1.24021.2 1.2337 25 7.2 1.3047 1.3608 1.23881.231.2 1.2389 26 7.0 1.3095 1.36741 1.23621. 1.2424 27 6.8 1.3119 1.37141.37 1.2326 1.2442 28 6.6 1.3121 1.3730 1.2278 1.2440 29 6.4 1.310303 1.3734 ATA1.2221 1.2420 30 6.2 1.30803080 1.3720.3720 1.2171 1.2386 31 6.0 1.3038 1.367777 1.2113 1.2346 32 5.8 1.2978 1.3629 1.2056 1.2279 33 5.6 1.2914.2914 1.35981.35 1.2043 1.2210 34 5.4 1.2854854 1.35671 LAL 1.2086 1.2200 35 5.2 1.27921.2 1.3516 1.2145 1.2211 36 5.0 1.27611.276 1.3489 1.2201 1.2212 37 4.8.8 1.2744 1.3492 1.2253 1.2198 38 4.6 1.27122712 1.3479 1.2301 1.2173 39 4.4 1.2692 PLP1.3471 1.2346 1.2138 40 4.2 1.26601.26 1.3441 1.2386 1.2094 41 4.0 1.26151.2 1.3386 1.2424 1.2044 42 3.83 1.2553 1.3306 1.2453 1.1989 43 3.6 1.2487 1.3199 1.2482 1.1935 444 3.43 1.2444 1.3069 1.2527 1.1891 454 3.22 1.2393 1.2933 1.2578 1.1866 46 3.0 MPM1.2330 1.2778 1.2642 1.1974 47 2.8 1.2281 1.2684 1.2734 1.2183 48 2.6 1.2307 1.2666 1.2903 1.2400 49 2.4 1.2337 1.2596 1.3040 1.2622 50 2.2 1.2345 1.2484 1.3143 1.2848 51 EME2.0 1.2327 1.2322 1.3201 1.3071 52 1.8 1.2281 1.2105 1.3198 1.3280 53 1.6 1.2202 1.1827 1.3114 1.3455 54 1.4 1.2079 1.1475 1.2925 1.3566 55 1.2 1.1895 1.1041 1.2600 1.3563 TTEMPLATETE56 1.0 1.1623 1.0500 1.2094 1.3373 Note: 1. Axial points 1-5 and 57-61 are excluded. Also, axial points within ±2% of the active core height of a grid location or a bank demand position are excluded.

Unit 1/2 Cycle 26 SEQUOYAH Page 16 of 19 Revision 0

Table 4 Rj Margin Decrease Factors for ROS1

Cycle Burnup Cycle Burnup (MWD/MTU) Rj (MWD/MTU) Rj ” 1.017 12100 1.0011 367 1.023 12318 1.001.001 585 1.026 ”%8”14056 1.000 802 1.027 14273 1.001 1019 1.025 14490 1.002 1236 1.022 14708 1.003.003 1454 1.018 14925 1.0055 1671 1.013 15142 1.006 1888 1.009 153603603 1.0071.01. E 2106 1.006 15577 1.008 2323 1.003 15794 1.009 2540 1.001 160116011 TET1.009 2757 1.000 16229229 1.010 2975 1.000 1644646 1.010 3192 1.001 16663 1.009 3409 1.0022 168801688 ATA 1.010 3626 1.001 170981 1.010 ”%8” 1.000 17315 1.010 5799 1.002 LAL17532 1.010 6017 1.00606 17750 1.010 6234 1.0101.01 17967 1.010 6451 1.012 18184 1.011 6668 1.013 PLP 18401 1.010 6886886 1.0111.01. 18619 1.009 7103 1.009 18836 1.008 7320 1.007 19053 1.006 7537 MPM 1.005 19271 1.005 7755 1.003 19488 1.003 797272 1.002 19705 1.002 8189 1.001 19922 1.001 ”%8””%8” EME 1.000 %8• 1.000 ValuesaluesTEMPLATETET maym be interpolated to the surveillance cycle burnup.

Unit 1/2 Cycle 26 SEQUOYAH Page 17 of 19 Revision 0

Table 5 Rj Margin Decrease Factors for ROS2

Cycle Burnup Cycle Burnup (MWD/MTU) Rj (MWD/MTU) Rj ” 1.033 15142 1.0055 367 1.035 15360 1.007.007 585 1.036 15577 1.008 802 1.035 15794 1.009 1019 1.032 16011 1.009 1236 1.028 16229 1.010.010 1454 1.023 16446 1.0100 1671 1.017 16663 1.010 1888 1.012 168808808 1.0091.01. E 2106 1.008 17098 1.009 2323 1.005 17315 1.009 2540 1.002 175327532 TET1.009 2757 1.001 17750750 1.009 ”%8” 1.000 1796767 1.009 6451 1.003 18184 1.010 6668 1.005055 184011840 ATA 1.009 6886 1.008 186191 1.009 7103 1.007 18836 1.008 7320 1.005 LAL19053 1.007 7537 1.004004 19271 1.005 7755 1.0021.0 19488 1.004 7972 1.001 19705 1.002 ”%8”” 1.000000 PLP 19922 1.001 14708708 1.0021.01. %8• 1.000 14925 1.004 Valuesues may be interpolatedMPM to the surveillance cycle burnup. EM TEMPLATE

Unit 1/2 Cycle 26 SEQUOYAH Page 18 of 19 Revision 0

Table 6 Required Thermal Power Limits and AFD Reductions

Required Required FQW(Z) THERMAL Required AFDAF RAOC Operating Margin POWER Limit Reductiontion Space Improvement (%) (%RTP) (%AFD)AFD)(1)

” ” •

ROS1 !DQG” ” • > 10.2 < 50 N/AN E ” ” •• ROS2 !DQG” ” TET• > 9.5 < 50 N/A

Note: 1. AFD reductions should be applied to both thee positive and negative sides of theth AFDATA operating space. LAL PLPLATE

TEMPL

Unit 1/2 Cycle 26 SEQUOYAH Page 19 of 19 Revision 0 Enclosure 1

Evaluation of the Transition to Westinghouse RFA-2 Fuel

ATTACHMENT 7

Revised Technical Requirements Manual (TRM) (Mark-Ups) for Units 1 and 2 (For Information Only)

CNL-20-014

62,000

SEQUOYAH UNITS 1 AND 2 TRM 8.3.1 TECHNICAL REQUIREMENTS MANUAL Revision 49 October 23, 2015

8.3 INSTRUMENTATION

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8.3.1-3

SEQUOYAH UNITS 1 AND 2 TRM 8.3.5 TECHNICAL REQUIREMENTS MANUAL Revision 49 October 23, 2015

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REFERENCES 1. WCAP--P-A, “BEACON Core Monitoring anG2SHUDWLRQV 6XSSRUW6\VWHP´$XJXVW

2. :HVWLQJKRXVHOHWWHUWR15&/TR-NRC-19-³5HTXHVWWR 0RGLI\6DIHW\(YDOXDWLRQ5HSRUWRQ:&$3--P-A, ‘BEACONTM &RUH0RQLWRULQJDQG2SHUDWLRQV6XSSRUW6\VWHP¶´ GDWHG6HSWHPEHU

8.3.6-9 Enclosure 1

Evaluation of the Transition to Westinghouse RFA-2 Fuel

ATTACHMENT 8

Compliance with Limitations and Conditions from NRC-Approved Newly Applied Topical Reports

CNL-20-014 SEQUOYAH FUEL TRANSITION LAR ATTACHMENT 8

COMPLIANCE WITH TOPICAL REPORT LIMITATIONS AND CONDITIONS

The following methodology topical reports, ordered in sequential number, support the Sequoyah Units 1 and 2 Technical Specification changes in this license amendment request.

WCAP-8745-P-$³'HVLJQ%DVHVIRUWKH7KHUPDO2YHUSRZHU¨7DQG7KHUPDO 2YHUWHPSHUDWXUH¨77ULS)XQFWLRQV´6HSWHPEHU

Applicable Technical Specifications:

3.3.1 Reactor Trip System Instrumentation; 5.6.3.b COLR Methodology 5HORFDWLRQRI27¨7DQG23¨7Reactor Trip System Instrumentation Setpoint Values to the COLR)

Limitation and Condition

“We have reviewed the Westinghouse design bases for the thermal overpower and RYHUWHPSHUDWXUH¨77ULSIXQFWLRQVGHVFULEHGLQ:&$3-8745 and find them acceptable for referencing by Westinghouse in licensing documents for plants that operate under constant axial offset control.

Although Section 1 of the topical report specifies its applicability to Westinghouse plants that reference RESAR-3S and operate under CAOC, Westinghouse has indicated that they FRQVLGHU:&$3-8745 applicable to all Westinghouse plants that employ overpower and RYHUWHPSHUDWXUH¨7WULSIRUFRUHSURWHFWLRQ:HVWLQJKRXVHKDVVWDWHGWKDWQHZPHWKRGV and WHFKQRORJ\GHYHORSHGDIWHUWKHVXEPLWWDORI:&$3-8745 are described in separate topical reports, and GRQRWLQYDOLGDWHWKHFRQFOXVLRQVRI:&$3-8745. As examples of such new methods, Westinghouse has cited changes in DNB analysis methodology (Improved Thermal 'HVLJQ3URFHGXUHDQG:5%-1 and WRB-2 correlations), fuel design (Optimized Fuel Assembly), and plant operating procedure (Relaxed Axial Offset Control), and referenced topical reports describing these changes. While we agree that the basic design philosophy GHVFULEHGLQ:&$3-8745 is not invalidated by changes in DNB analysis methodology, fuel design, and plant operating procedure, the application of this methodology must account for changes in system design and operation. The adequacy of the standard power shapes in establishing the core DNB protection system must be evaluated whenever changes are introduced that could potentially affect the core power distribution.”

Compliance

Sequoyah will operate under Relaxed Axial Offset Control (RAOC) as approved in :&$3-10216-3-A. The NRC Safety Evaluation (SE) IRU:&$3-14483-A (page 2) DFNQRZOHGJHVWKHDFFHSWDELOLW\RIXVLQJ:&$3-8745-3-A as a setpoint methodology to be referenced in Sequoyah Technical Specification 5.6.3.b. 2YHUSRZHU¨7DQG2YHUWHPSHUDWXUH ¨T setpoint adequacy for limiting power distributions will be verified on a cycle-specific basis XVLQJWKH:HVWLQJKRXVHUHORDGPHWKRGRORJ\GHVFULEHGLQ:&$3-9272-3-A.

Enclosure 1 Attachment 8 - 1 of 45 WCAP--P-$³:HVWLQJKRXVH5HORDG6DIHW\(YDOXDWLRQ0HWKRGRORJ\´-XO\

Applicable Technical Specification:

5.6.3.b COLR Methodology (methodology for Shutdown Margin, Moderator Temperature Coefficient, Shutdown Bank Insertion Limit, Control Bank Insertion Limits, Axial Flux Difference, Heat Flux Hot Channel Factor, Nuclear Enthalpy Rise Hot Channel Factor, DNB /LPLWV5HIXHOLQJ3RRO Boron Concentration)

Limitation and Condition

“We have reviewed the Westinghouse Reload Safety Evaluation Methodology described in :&$3-9272 and find it acceptable for referencing by Westinghouse in licensing documents. Since quantitative criteria are not available for determining when an accident re-evaluation rather than a reanalysis can be performed, justification for any reevaluation should be presented in individual Reload Safety Evaluation reports.”

Compliance

The Reload Safety Evaluation process will be implemented for Sequoyah Units 1 and 2 beginning with the first partial core loading of RFA-2 fuel.

Enclosure 1 Attachment 8 - 2 of 45 WCAP--P-$5HYLVLRQ$³5HOD[DWLRQRI&RQVWDQW$[LDO2IIVHW&RQWURO– FQ 6XUYHLOODQFH7HFKQLFDO6SHFLILFDWLRQ´)HEUXDU\

This topical report is already in Sequoyah’s current licensing basis (UFSAR Sections 4.3.2.2.6 and 4.3.4 Reference 30).

Applicable Technical Specifications:

3.2.1 Heat Flux Hot Channel Factor; 3.2.3 Axial Flux Difference; 5.6.3.b COLR Methodology (methodology for Axial Flux Difference limits with Relaxed Axial Offset Control and Heat Flux Hot Channel Factor (W(z)) Surveillance Requirements for FQ)

Limitation and Condition

“The proposed revisions to the FQ Surveillance Technical Specification in those reactors using CAOC or RAOC for power distribution control are acceptable. These revisions would allow the incorporation of a larger penalty to account for FQ(z) increases greater than 2 percent between measurements. These penalties may be incorporated in either the plant 3)/5 or COLR, as described above, and will be calculated with NRC-approved methods. The approved version of :&$3-10216-35HYPXVWEHLQFOXGHGLQWKH$GPLQLVWUDWLYH5Hporting Requirements Section of the TS for those plants incorporating the penalty factor in the COLR. Also, TS Surveillance 4.2.2.2.e.l must be modified to reflect inclusion of this parameter in the 3)/5 or COLR.”

Compliance

The LCO in Sequoyah Technical Specification 3.2.1 requires compliance with the FQ limit VSHFLILHGLQWKH&2/57HFKQLFDO6SHFLILFDWLRQELVEHLQJUHYLVHGWROLVW:&$3-10216-3-A as a COLR methodology reference.

Enclosure 1 Attachment 8 - 3 of 45 WCAP--P-$³5HIHUHQFH&RUH5HSRUW9$17$*()XHO$VVHPEO\´6HSWHPEHU

Applicable Technical Specifications:

5.6.3.b COLR Methodology (methodology for Axial Flux Difference and Heat Flux Hot Channel Factor Limits)

This topical report is already in Sequoyah’s current licensing basis (UFSAR Sections 4.2.1.2.1, 4.2.1.2.2, 4.2.1.3.4, 4.2.4 Reference 20, 4.4.2.7.2, 4.4.6 Reference 93).

Limitation and Condition #1

“7KHVWDWLVWLFDOFRQYROXWLRQPHWKRGGHVFULEHGLQ:&$3-10125 for the evaluation of initial fuel rod to nozzle growth gap has not been approved. This method should not be used in VANTAGE 5.”

Compliance

Not applicable to this license amendment request. The Rod Axial Growth Model in Section 5.9 of the 3$' WRSLFDOUHSRUW :&$3-17642-3-A) was used for the Sequoyah reload transition safety report (RTSR) analysis.

Limitation and Condition #2

“For each plant application, it must be demonstrated that the LOCA/seismic loads considered in :&$3-9401 bound the plant in question; otherwise additional analysis will be required to demonstrate the fuel assembly structural integrity.”

Compliance

Detailed site-specific seismic and loss of coolant accident (LOCA) fuel assembly analyses for Sequoyah Units 1 and 2 have been performed in accordance with approved methodologies. These methodologies were approved by the NRC LQ:&$3-12610-3-A, :&$3-12488-A, :&$3-9401DQG3:52*-16043-3-A.

The analysis predicted no permanent grid deformation (grid crush) to occur in both homogeneous core and mixed cores for Sequoyah Units 1 and 2 under combined seismic and LOCA loadings.

The fuel assembly stress evaluation was performed for the limiting seismic and LOCA (accumulator injection line and pressurizer surge line breaks) loads assuming both a full homogeneous core of RFA-2 fuel and a mixed core of RFA-2 and )UDPDWRPH+73IXHO7KH results show that all grid impact forces on the 17x17 RFA-2 fuel remain below the grid impact strength for both the homogeneous and mixed core configurations. The stresses in the guide thimbles remain below the allowable stress limits for the ZIRLO thimble tubes and the fuel rod stresses remain below the allowable stress limits for the 2SWLPL]HG=,5/2TM cladding. For the Sequoyah units, it is concluded that the 17x17 RFA-2 seismic and LOCA analysis for Conditions I, II, III, and IV demonstrates that core coolability is maintained, full control rod insertion within the allowed rod drop time is maintained, and fuel rod fragmentation will not occur. This discussion will be added to Sequoyah UFSAR Section 4.2.1.3.2.

Enclosure 1 Attachment 8 - 4 of 45 Limitation and Condition #3

“An irradiation demonstration program should be performed to provide early confirmation performance data for the VANTAGE 5 design.”

Compliance

Not applicable to this license amendment request. Since the time of this SE, the VANTAGE 5, VANTAGE 5H, RFA, and RFA-2 fuel designs have collective operating experience in the hundreds of reactor-years.

Limitation and Condition #4

”)RUWKRVHSODQWVXVLQJWKH,7'3WKHUHVWrictions enumerated in Section 4.1 of this report must be addressed and information regarding measurement uncertainties must be provided.”

Compliance

The 5HYLVHG7KHUPDO'HVLJQ3URFHGXUH 57'3 ZDVXVHGIRUWKH6HTXR\DK5765DQDO\VHV 6HHWKHGLVFXVVLRQRI:&$3-11397-3-A. 7KHGLVFXVVLRQRI:&$3-11837-3-A also contains relevant information on transition core DNBR penalties.

Limitation and Condition #5

“The WRB-2 correlation with a DNBR limit of 1.17 is acceptable for application to 17x17 VANTAGE 5 fuel. Additional data and analysis are required when applied to 14x14 or 15x15 fuel with an appropriate DNBR limit. The applicability range of WRB-2 is specified in Section 4.2.”

Compliance

Not applicable to this license amendment request. The WRB-2M DNBR correlation with a DNBR limit of 1.14 is used for RFA-2 fuel to be loaded at the Sequoyah units as discussed XQGHU:&$3-15025-3-A.

Limitation and Condition #6

“For 14x14 and 15x15 VANTAGE 5 fuel designs, separate analyses will be required to determine a transitional mixed core penalty. The mixed core penalty and plant specific safety margin to compensate for the penalty should be addressed in the plant Technical Specifications Bases.”

Enclosure 1 Attachment 8 - 5 of 45 Compliance

Not applicable to this license amendment request. 17x17 RFA-2 fuel is being loaded at the Sequoyah units.

Limitation and Condition #7

“3ODQWVSHFLILFDQDO\VLVVKRXOGEHSHUIRUPHGWRVKRZWKDWWKH'1%5OLPLW will not be violated with the higher value of F¨H.”

Compliance

There will be no DNBR OLPLWYLRODWLRQVDVGLVFXVVHGXQGHU:&$3-11837-3-$:&$3-11397-3- N ADQG:&$3-14545-3-A. A 5 percent F ǻ+ reduction (from 1.70 to 1.61) will be applied to the Framatome +73IXHOGXULQJWKHWUDQVLWLRQFRUHF\FOHV.

Limitation and Condition #8

“The plant-specific safety analysis for the steam system piping failure event should be performed with the assumption of loss of offsite power if that is the most conservative case.”

Compliance

The main steam line rupture was analyzed under both cases, with and without offsite power available.

Limitation and Condition #9

“With regard to the RCS pump shaft seizure accident, the fuel failure criterion should be the 95/95 DNBR limit. The mechanistic method mentioned in WC$3-10444 is not acceptable.”

Compliance

In the locked rotor analysis performed for the Sequoyah RTSR, rods experiencing DNB are assumed to fail with respect to the radiological consequence analysis. The rods-in-DNB were calculated usLQJWKH9,35(-:FRGH :&$3-14565-3-A). The maximum percentage of fuel rods calculated to experience DNB was confirmed to be less than the 10 percent limit used in the radiological dose analysis.

Limitation and Condition #10

“If a positive MTC is intended for VANTAGE 5, the same positive MTC consistent with the plant Technical Specifications should be used in the plant specific safety analysis.”

Compliance

The moderator temperature coefficient (MTC) upper limit in the Technical Specifications, as specified in the COLR, is 0 pcm/qF. However, certain events are analyzed with an MTC of +5 pcm/qF as noted in the markups to UFSAR Chapter 15.

Enclosure 1 Attachment 8 - 6 of 45 Limitation and Condition #11

“The LOCA analysis performed for the reference plant with higher FQ of 2.55 has shown that the 3&7OLPLWRI๦F is violated during transitional mixed core configuration. 3ODQWVSHFLILF/2&$ analysis must be done to show that with the appropriate value of FQ, the 2200qF criterion can be met during use of transitional mixed core.” Compliance

The FSLOCA evaluation model (EM) :&$3-16996-3-A Revision 1) analysis performed for the Sequoyah RTSR used an FQ of 2.65 (a surveillance limit of 2.62 will be used until a full core of RFA-2 fuel is loaded) and calculated a small break (Region I) peak cladding temperature (3&7) of 1213qF and a ODUJHEUHDN 5HJLRQ,, 3&7RIqF. During transitional mixed core FRQILJXUDWLRQVZLWKUHVLGHQW+73IXHOWKH:HVWLQJKRXVH5)$-2 fuel will not be penalized due to its overall lower loss coefficients. While the FSLOCA EM analysis does not explicitly address the co-UHVLGHQW+73IXHODQGWKLV/ &GRHVQRWWKHUHIRUHGLUHFWO\DSSO\LWLVQRWHGWKDWD transition core assessment has determined that the 2200°F criterion continues to be met by the +73IXHOGXULQJWUDQVLWLRQcycles.

Limitation and Condition #12

“2XU6(5RQ:HVWLQJKRXVH VH[WHQGHGEXUQXSWRSLFDOUHSRUW:&$3-10125 is not yet complete; the approval of the VANTAGE 5 design for operation to extended burnup levels is contingent on NRC approval of W&$3-10125. However, VANTAGE 5 fuel may be used to those burnups to which Westinghouse fuel is presently operating. Our review of the Westinghouse extended burnup topical report has not identified any safety issues with operation to the burnup value given in the extended burnup report.”

Compliance

Not applicable to this license amendment request. This limit was increased to a lead rod DYHUDJHEXUQXSRI*:G078IRU:HVWLQJKRXVHIXHO :&$3-10444-3-$DQG:&$3-12610- 3-$ SURYLGHGWKDW3$' :&$3-15063-3-A) or later fuel performance codes were used 15&OHWWHUIURP-'3HUDOWDWR:HVWLQJKRXVHGDted May 25 2006, “Approval for Increase in Licensing Burnup Limit to 62,000 MWD/MTU (TAC NO. MD1486),” ADAMS Accession Number ML061420458). 3$'DQGthe FSLOCA EM have been approved for use up to a lead rod average burnup of 62 GWd/MTU for all approved types of cladding.

Limitation and Condition #13

“Recently, a vibration problem has been reported in a French reactor having 14-foot fuel assemblies; vibration below the fuel assemblies in the lower portion of the reactor vessel is damaging the movable incore instrumentation probe thimbles. The staff is currently evaluating the implications of this problem to other cores having 14 foot long fuel bundle assemblies. Any limitations to the 14-foot core design resulting from the staff evaluation must be addressed in plant-specific evaluations.”

Compliance

Not applicable to this license amendment request. The RFA-2 fuel assemblies to be loaded at Sequoyah are of the standard 12-foot length.

Enclosure 1 Attachment 8 - 7 of 45 WCAP--P-$$GGHQGXP-A, ³9$17$*(+ )XHO$VVHPEO\´)HEUXDU\

Applicable Technical Specifications:

5.6.3.b COLR Methodology (methodology for Axial Flux Difference and Heat Flux Hot Channel Factor Limits)

This topical report is already in Sequoyah’s current licensing basis (UFSAR Sections 4.1.1 Reference 2, 4.2.1.2, 4.2.1.3.2, 4.2.4 Reference 19, 4.4.1.1, 4.4.2.3.1, 4.4.6 Reference 87).

Limitation and Condition

³7KH:&$3-10444-3-A Addendum 2 provides an acceptable method for the application of the :&$3-10444-3-A information in the use of the VANTAGE 5H fuel assemblies in complete and transition core configurations.

)RUWUDQVLWLRQFRUHVWKHWUDQVLWLRQFRUHFRQILJXUDWLRQSHQDOW\VSHFLILHGLQ:&$3-10444-3-A will apply for the estimation of the peak clad temperature in large LOCA analyses.”

Compliance

The Sequoyah Units 1 and 2 analysis with the FSLOCA (0 :&$3-16996-3-A Revision 1) was performed assuming a full core of Westinghouse RFA-2 fuel. For the initial cycles in which Westinghouse RFA-IXHOLVXVHGKRZHYHU)UDPDWRPHKLJKWKHUPDOSHUIRUPDQFH +73 IXHO will also be present. While the two fuel designs have generally similar mechanical designs, a transition core evaluation was performed to address the mixed core effects for both fuel types.

The loss coefficient of the Westinghouse RFA-IXHOLVVOLJKWO\ORZHUWKDQWKH)UDPDWRPH+73 fuel, and the analysis with the FSLOCA EM assuming a homogeneous core of RFA-2 fuel is bounding of the mixed core effect for Westinghouse fuel, because the RFA-2 fuel would receive a flow benefit in the SUHVHQFHRIWKHUHODWLYHO\VWDUYHG+73IXHO

$QHYDOXDWLRQZDVWKHUHIRUHSHUIRUPHGWRDVVHVVWKH3&7HIIHFWRIWKH5)$-2 on the )UDPDWRPH+73IXHOZLWKLQWKHFRQWH[WRIWKHH[LVWLQJDQDO\VLVRIUHcord (AOR) supporting operation with that fuel type.

For SBLOCA transients, core-wide collapsed liquid levels correspond closely to a 1-dimensional (1-D) flow pattern, and the effects of grid loss coefficient differences among the assemblies are not significant LQGHWHUPLQLQJWKH3&7 As such, the existing analysis of record supporting operation with Framatome +73IXHOLVDSSOLFDEOHIRUWKH)UDPDWRPH+73IXHOGXULQJWKH transition cycle(s) to Westinghouse RFA-2 fuel.

For LBLOCA transients, conditions during blowdown and reflood can be affected by mixed core conditions arising from a hydraulic mismatch. The existing AOR performed with the best estimate (BE) $5(9$)UDPDWRPH5/%/2&$PHWKRGRORJ\UHVXOWHGLQD3&7RFFXUULQJDURXQG 265 seconds after the postulated break during the reflood period. 7KH3&7LQFUHDVHIRU )UDPDWRPH+73IXHOUHVXOWLQJIURPWKH hydraulic mismatch was estimated to be 23°F, based on the expected effects on a transient with the reflood time and cladding heatup rate consistent with the Sequoyah Units 1 and 2 RLBLOCA analysis. 7KH3&7HVWLPDWHRIHIIHFWRIƒ)LV DSSOLFDEOHIRUWKH)UDPDWRPH+73IXHOGXULQJWUDQVLWLRQF\FOHVWR Westinghouse RFA-2 fuel.

Enclosure 1 Attachment 8 - 8 of 45 7KHWUDQVLWLRQFRUH3&7SHQDOW\GLVFXVVHGLQ6HFWLRQs 1.2.d, 5.2.1, and 5.2.3 RI:&$3-10444- 3-$LVQRWDSSOLFDEOHWRWKH+73IXHORUWKHXVHRIWKHFSLOCA EM in this license amendment request. Even if WKDWREVROHWHWUDQVLWLRQFRUH3&7SHQDOW\ZHUHWREHDSSOLHGLWZRXOGEH insignificant in comparison to the 322qF margin to the 2200qF regulatory limit. See also the GLVFXVVLRQRI/LPLWDWLRQDQG&RQGLWLRQXQGHU:&$3-10444-3-A.

Enclosure 1 Attachment 8 - 9 of 45 WCAP--P-A, ³$1&$:HVWLQJKRXVH$GYDQFHG1RGDO&RPSXWHU&RGH´ 6HSWHPEHU 

Applicable Technical Specifications:

5.6.3.b COLR Methodology (methodology for Shutdown Margin, Moderator Temperature Coefficient, Shutdown Bank Insertion Limit, Control Bank Insertion Limits, Axial Flux Difference, Heat Flux Hot Channel Factor, Nuclear Enthalpy Rise Hot Channel Factor, RefuHOLQJ3RRO%RURQ Concentration)

This topical report is already in Sequoyah’s current licensing basis (UFSAR Sections 4.3.2.3.1, 4.3.3.3, 4.3.4 Reference 31).

Limitation and Condition

“The ANC code provides an accurate calculation of core reactivity, reactivity coefficients, critical boron, rod worths and core power distribution for use in design and safety analyses. The TXDOLILFDWLRQSUHVHQWHGLQ:&$3-10965 demonstrates that the accuracy of the ANC prediction of these quantities is generally comparable to that of TORTISE.”

Compliance

The ANC code is used in accordance with the approved topical report for the Sequoyah RTSR. This topical report is discussed in Sequoyah UFSAR Sections 4.3.2.3.1 and 4.3.3.3 (cited as Reference 31 – SQN UFSAR will be updated to the approved September 1986 reference). See DOVRWKH3$5$*21DQG1(;86$1&GLVFXVVLRQVXQGHU:&$3-16045-3-A and :&$3-16045-3-A Addendum 1-A.

Enclosure 1 Attachment 8 - 10 of 45 WCAP--P-$$GGHQGXP-$5HYLVLRQ³4XDOLILFDWLRQRIWKH1HZ3LQ3RZHU 5HFRYHU\0HWKRGRORJ\´6HSWHPEHU

Applicable Technical Specifications:

5.6.3.b COLR Methodology (methodology for Shutdown Margin, Moderator Temperature Coefficient, Shutdown Bank Insertion Limit, Control Bank Insertion Limits, Heat Flux Hot Channel Factor, Nuclear Enthalpy Rise Hot Channel Factor, Axial Flux Difference, TS 3.4.1 DNB Limits, Refueling 3RRO%RURQ&RQFHQWUDWLRQ 

Limitation and Condition

“Westinghouse has provided a series of simulations to demonstrate the performance of the ANC code with the new pin power recovery methodology for control rod histories that exacerbate heterogeneous environments. These calculations confirm that the new pin power methodology is accurate for both unrodded and rodded pin power predictions. 3LQSRZHUKLVWRULHVFRPSXWHG with the ANC code, as presented in this safety evaluation, are dependent on the results of the 15&DSSURYHGFRGHV3$5$*21 5HIHUHQFH; VHHGLVFXVVLRQRI:&$3-16045-3-A) and 1(;86 5HIHUHQFH; VHHGLVFXVVLRQRI:&$3-16045-3-A Addendum 1-A). Thus, the use of $1&ZLWKWKHQHZSLQSRZHUUHFRYHU\PHWKRGRORJ\GHVFULEHGLQWKH:&$3-10965-3-A, $GGHQGXP:&$3-10966-A, Addendum 2, TR in licensing applications requires the FRQFRPLWDQWDSSOLFDWLRQRIWKH15&DSSURYHGODWWLFHFRGH3$5$*21DQGWKH15&DSSURYHG FURVVVHFWLRQSDUDPHWHUL]DWLRQDQGUHFRQVWUXFWLRQPHWKRGRORJ\RIWKH1(;86FRGHV\VWHP.

The NRC staff has reviewed the TR submitted by Westinghouse and determined that :&$3-10965-3$GGHQGXP:&$3-10966-A, Addendum 2, is an adequate enhancement to replace the pin power recovery methodologies of NRC-DSSURYHGPHWKRGRORJLHV:&$3-10965- 3-A, DQGZKHUHDSSURSULDWHRI:&$3-10965-3-A, Addendum 1.”

Compliance

7KHSLQSRZHUUHFRYHU\PHWKRGIROORZV:&$3-10965-3-A Addendum 2-A in concert with 1(;86$1&ZKLFKXVHVWKH3$5$*21ODWWLFHFRGH

Enclosure 1 Attachment 8 - 11 of 45 WCAP--P-A, “([WHQVLRQRI0HWKRGRORJ\IRU&DOFXODWLQJ7UDQVLWLRQ&RUH'1%5 3HQDOWLHV´-DQXDU\

Applicable Technical Specification:

2.1.1.1 (Relocation of Safety Limits Figure to the COLR and new DNB Safety Limit)

Limitation and Condition #1

“Because the basic DNBR computational methodology is the same as has been previously used and approved, the restrictions and recommendations with respect to the DNBR methodology cited in the previous SERs will also be applicable in this extension.”

Compliance

The limitations and conditions for DNBR methodologies are discussed under the WRB-2M, ABB-19DQG:/23WRSLFDOUHSRUWV

Limitation and Condition #2

“Because the resulting curve fit used in the extension is a statistical fit through a set of data points corresponding to the DNBR penalties at different fractions of VANTAGE 5 fuels in the transition core, there is an error bound associated with it (Ref. 8) [Westinghouse letter NS-NRC-89-3450 dated 8-1-89]. Therefore, whenever data is read from the curve, its associated error bound should be simultaneously quoted and the data used should incorporate the uncertainty bound in a conservative manner.”

Compliance

For the Sequoyah RTSR, it was determined that a bounding transition core penalty would be reported for the 17x17 RFA-2 fuel, for separate use with the WRB-2M and ABB-NV correlations.

The transition core DNBR penalty for the Sequoyah RTSR is based on a comparison of the DNBR results obtained by modeling two different configurations of 3x3 fuel assembly arrays. One model represents a uniform array of Westinghouse 17x17 RFA-2 fuel assemblies (with intermediate flow mixers (IFM)) and the other model represents a mixed array of the Westinghouse and Framatome fuel types, i.e., one Westinghouse assembly surrounded by eight Framatome assemblies.

For the sake of conservatism, the design limit transition core penalty has been rounded up by >10.0 percent from the transition core penalty that was obtained from the mixed core analysis. The DNBR results were computed within the respective correlation limits for quality and pressure.

$VHSDUDWHFDOFXODWLRQZDVSHUIRUPHGZLWKWKH9,35(-W code to analyze the impact of the WUDQVLWLRQFRUHHIIHFWRQWKH)UDPDWRPH+73IXHO7KHVDPHPHWKRGRORJ\DQGSURFHVVWKDW was used on the RFA-2 aVVHPEOLHVZDVDSSOLHGWRWKH+73IXHO

The transition core DNBR penalty for the Sequoyah RTSR is based on a comparison of the DNBR results obtained by modeling two different configurations of 3x3 fuel assembly arrays. One model represents a uniform arra\RI)UDPDWRPH[+73IXHODVVHPEOLHVDQGWKHRWKHU

Enclosure 1 Attachment 8 - 12 of 45 PRGHOUHSUHVHQWVDPL[HGDUUD\RIWKH:HVWLQJKRXVHDQG)UDPDWRPHIXHOW\SHVLHRQH+73 assembly surrounded by eight RFA-2 assemblies.

Limitation and Condition #3

“Since the case which represents the smallest fraction of VANTAGE 5 in the core in this submittal resulted in the bounding DNBR penalty, should a transition core involve a smaller fraction than 0.11 of VANTAGE 5 fuel assemblies, its DNBR penalty must be explicitly computed rather than using an extrapolated value from this curve.”

Compliance

Not applicable to this license amendment request. The first transition core will contain RFA-2 fuel assemblies in more than 11% of the core. Subsequent transition cores will contain a higher percentage of RFA-2 fuel.

Limitation and Condition #4

“Westinghouse's conclusion with respect to the regions of applicable penalties as described in the concluding paragraph of the subject topical report requires further qualification. Since (a) the study described in Reference 3 [Westinghouse letter NS-(35-2643 dated 8-17-82] only considered transition from STD to OFA using a limited set of conditions, and (b) the limiting set of conditions identified in References 1 and 4 [:&$3-11837-3-$DQG:&$3-10444-3-A] was not used, and (c) all transition core effect studies presented in these reports analyzed generic cores, before any actual penalty from this reference is applied in a plant-specific transient analysis, Westinghouse should demonstrate that (1) the conditions for the analysis then under consideration are within the range of applicability (ranges of power, pressure, mass flux, and inlet temperature, and one of the three axial power shapes) considered in this study, and (2) that the case then being analyzed was otherwise similar to the cases used to develop the curves in this study (i.e., DNB occurred in the same general region of the core so that fluid element history was similar). If Westinghouse is unable to so demonstrate at such time, further justification will be necessary.”

Compliance

The conditions for the analysis under consideration are within the range of applicability (ranges of power, pressure, mass flux, and inlet temperature, and one of the three axial power shapes) considered in WC$3-11837-3-A, and the cases analyzed were otherwise similar to the cases used to develop the curves in :&$3-11837-3-A.

Enclosure 1 Attachment 8 - 13 of 45 WCAP--P-A, ³5HYLVHG7KHUPDO'HVLJQ3URFHGXUH´$SULO

Applicable Technical Specifications:

2.1.1.1 (Relocation of Safety Limits Figure to the COLR and new DNB Safety Limit) 5.6.3.b COLR Methodology (methodology for Reactor Core Safety Limits, Nuclear Enthalpy Rise Hot Channel Factor, TS 3.4.1 DNB Limits)

This topical report is already in the Sequoyah current licensing basis (UFSAR Sections 4.4.1.1, 4.4.6 Reference 95).

Limitation and Condition #1

“Sensitivity factors used for a particular plant and their ranges of applicability should be included in the Safety Analysis Report or reload submittal.”

Compliance

Sensitivity factors were calculated using the WRB-2M, ABB-NVDQG:/23 DNB correlations and WKH9,35(-W code for parameter values applicable to the RFA-2 fuel transition at Sequoyah. 7KHVHVHQVLWLYLW\IDFWRUVZHUHXVHGWRGHWHUPLQHWKH57'3GHVLJQlimit DNBR values for the DNB correlations. The safety analysis DNBR limit is 1.58 for the Sequoyah RTSR DNB analyses. The DNBR design limit value is 1.23 for both typical and thimble cells with the WRB-2M correlation for RFA-2 fuel. The DNBR design limit values for the ABB-NV correlation are 1.18 for typical cells and 1.19 for thimble cells below the first mixing vane region of the RFA-2 fuel.

Limitation and Condition #2

“Any changes in DNB correlation, THINC-IV correlations, or parameter values listed in Table 3-1 RI:&$3-11397 outside of previously demonstrated acceptable ranges require re-evaluation of the sensitivity factors and of the use of Equation (2-3) of the topical report.”

Compliance

Because WKH9,35(-W code is used to replace the THINC-IV code for the Sequoyah RTSR, VHQVLWLYLW\IDFWRUVIRUWKH57'3PHWKRGRORJ\ZHUHFDOFXODWHGXVLQJWKH9,35(-W code for parameter values applicable to the RFA-2 fuel transition at Sequoyah, as discussed in the response to Limitation and Condition #1 above. See the Response to Limitation and Condition #3 for a discussion of the use of Equation (2-3) of the topical report.

Limitation and Condition #3

“If the sensitivity factors are changed as a result of correlation changes or changes in the application or use of the THINC code, then the use of an uncertainty allowance for application of Equation (2-3) must be re-evaluated and the linearity assumption made to obtain Equation (2-17) of the topical report must be validated.”

Enclosure 1 Attachment 8 - 14 of 45 Compliance

As described in :&$3-14565-3-AWKH9,35(-W code has been demonstrated to be equivalent to the THINC code. Equation (2-3) of :&$3-11397-3-A and the linearity approximation made to obtain Equation (2-17) were confirmed to be valid for the Sequoyah RTSR for the combination of the WRB-2M FRUUHODWLRQDQGWKH9,35(-W code as well as for the combination of the ABB-NV DQG:/23correlations DQGWKH9,35(-W code.

Limitation and Condition #4

“Variances and distributions for input parameters must be justified on a plant-by-plant basis until generic approval is obtained.”

Compliance

There were no changes to the operating parameter uncertainties for the Sequoyah RTSR.

Limitation and Condition #5

“Nominal initial condition assumptions apply only to DNBR analyses using 57'3 Other analyses, such as overpressure calculations, require the appropriate conservative initial condition assumptions.”

Compliance

For the Sequoyah RTSR, nominal initial conditions were only applied to DNBR calculations that used the 57'3

Limitation and Condition #6

“Nominal conditions chosen for use in analyses should bound all permitted methods of plant operation.”

Compliance

The nominal conditions used in the Sequoyah RTSR are discussed under Limitation and &RQGLWLRQRI:&$3-14565-3-A. The continued applicability of the bounding input assumptions will be verified on a cycle-specific basis using the Westinghouse reload methodology described in :&$3-9272-3-A.

Limitation and Condition #7

“The code uncertainties specified in Table 3-1 (± 4 percent for THINC-IV and ± 1 percent for transients) must be included in the DNBR analyses XVLQJ57'3”

Compliance

The code uncertainties specified in Table 3-1 of :&$3-11397-3-A remain unchanged and were LQFOXGHGLQWKH'1%5DQDO\VHVXVLQJ57'3 The THINC-IV uncertainty was applied to 9,35(-WEDVHGRQWKHHTXLYDOHQFHRIWKH9,35(-W model approved in :&$3-14565-3-A to THINC-IV.

Enclosure 1 Attachment 8 - 15 of 45 WCAP--P-A, “BEACON Core Monitoring anG2SHUDWLRQV6XSSRUW6\VWHP´ August 

Applicable Technical Specifications for BEACON-760&RUH3RZHU'LVWULEXWLRQ0HDVXUHPHQW:

 5RG3RVLWLRQ,QGLFDWLRQ  4XDGUDQW3RZHU7LOW5DWLR 3.3.1 (Reactor Trip System Instrumentation)

Limitation and Condition

“The staff has reviewed the BEACON system as described in References 2 [Topical Report :&$3-12472-3‘BEACON Core Monitoring and Operations support Systems’," April 1990, C. Beard and T. Morita] and 3 [Letter, with enclosed report, from N. Liparulo, Westinghouse, to R. Jones, NRC, November 4, 1992, "Responses to NRC Request for Additional Information for :&$3-12472-3], the proposed technical specifications for operating with and without that system operable as described in Reference 3, and the attached Brookhaven TER.

BEACON provides a greatly improved continuous on-line power distribution measurement and display, limit surveillance, and operation prediction information system for Westinghouse reactors. No new instrumentation or calculation system (other than interface systems and integration analysis) is introduced. The system is potentially suitable for other reactors, but has been examined in the topical report and by the staff only for current standard Westinghouse systems. Acceptance for others would require further review and approval.

As discussed in the attached TER (section 4.0, "Technical 3RVLWLRQ WKHV\VWHPUHYLHZKDV concluded that BEACON is acceptable for performing core monitoring and operations support, subject to conditions stated in TER sections 3.3 and 3.4 on uncertainties. As discussed in this staff evaluation, the revised proposed TSs provided in Reference 3 (Chapter 7 revision) are acceptable, with the exception of the placement of the thermocouple and incore detector operating limits in the COLR. They should be returned to TS 3/4.3.3.12. The condition stated in TER section 4.0.(3) with references to the TSs has been satisfied in the Reference 3 revision.”

Brookhaven Technical Evaluation Report (TER)

“The BEACON Core Monitoring and Operations Support System Topical Report :&$3- 12472-3DQGVXSSRrting documentation provided in Reference 9 [Responses to NRC 5HTXHVWIRU$GGLWLRQDO,QIRUPDWLRQIRU:&$3-12472-3 3URSULHWDU\ /HWWHU1 J. Liparulo (W) to R. C. Jones (NRC), dated November 4, 1992] have been reviewed in detail. Based on this review, it is concluded that the BEACON system is acceptable for performing core monitoring and operations support functions for Westinghouse 3:5V subject to the conditions stated in Section-3 of this evaluation and summarized in the following.

1) In the cycle-specific applications of BEACON, the power peaking uncertainties U¨h and UQ must provide 95% probability upper tolerance limits at the 95% confidence level (Section 3.3).

2) In order to insure that the assumptions made in the BEACON uncertainty analysis remain valid, the generic uncertainty components may require reevaluation when

Enclosure 1 Attachment 8 - 16 of 45 BEACON is applied to plant or core designs that differ sufficiently to have a significant impact on the :&$3-12472-3GDWD-base (Section 3.4).

3) The BEACON Technical Specifications should be revised to include the changes described in Section 3 concerning Specifications 3.1.3.1 and 3.1.3.2 and the Core Operating Limits Report (Section 3.6).”

Compliance

Implementation of BEACON at the Sequoyah units uses the current standard Westinghouse systems. There are no changes to BEACON core monitoring methodology for the Sequoyah units.

The following discussions address the findings in the Brookhaven TER.

1) The 95/95 requirement in TER Section 3.3 is met.

The uncertainties to be applied to the BEACON power distribution measurements are calculated differently than those applied to the traditional flux map systems because BEACON uses a more comprehensive set of instrumentation.

The uncertainty in the BEACON power peaking resulting from errors in the model calibration and core exit thermocouple (CETC) calibration is determined using a Monte Carlo error propagation technique. In this analysis, the BEACON three-step calibration, model update, and power distribution update procedure are simulated. The model and CETC calibration factors are subjected to random variations, based on their uncertainties, and the resulting variations in the BEACON power distribution are used to determine the 95% probability upper tolerance limit on the assembly power for the approximately twenty highest powered assemblies.

The analysis is performed for a range of operating conditions including off-normal power distributions and extended calibration intervals. A typical set of CETC uncertainties is used together with a relatively large tolerance factor, which results in substantial smoothing of the CETC measurements. The upper tolerance limit on the assembly power peaking factor is calculated and found to increase as the square root of the CETC uncertainty.

N The F ǻ+ and FQ(Z) uncertainties are determined by a statistical combination of the assembly peaking factor, axial peaking factor, model calibration interval, inoperable movable incore detectors, inoperable core exit thermocouples, grid factor, and local N power peaking component uncertainties. The F ǻ+ and FQ(Z) uncertainties are continuously updated by the 3RZHU'LVWULEXWLRQ0RQLWRULQJ6\VWHP (3'06) for actual operating conditions.

The accuracy of the BEACON analysis decreases as the calibration intervals increase and the power distribution diverges from the reference power shape. In order to minimize BEACON uncertainty, the reference power distribution is updated every 15 minutes, or when significant changes occur in the AFD or reactor power.

Enclosure 1 Attachment 8 - 17 of 45 ,IWKH3'06LVfunctional, the core power distribution measurement uncertainty (U)¨+) to N be applied to the F¨H using the 3'06VKDOOEHWKHJUHDWHURI

U)¨+ = 1.04 or U)¨+ = 1.0 + (U¨H / 100)

where:

U¨H = Uncertainty for power peaking factor as defined in Equation 5-19 from :&$3-12472-3-A.

7KLVXQFHUWDLQW\LVFDOFXODWHGDQGDSSOLHGDXWRPDWLFDOO\E\WKH3DMS.

,IWKH3'06LVQRWIXQFWLRQDOthe core power distribution measurement uncertainty N (U)¨+) to be applied to the F¨H shall be 1.04.

,IWKH3'06LVfunctional, the core power distribution measurement uncertainty (UFQ) to be applied to FQ = XVLQJWKH3'06VKDOOEHFDOFXODWHGE\

UFQ = (1.0 + (UQ / 100)) * UE

where:

UQ = Uncertainty for power peaking factor as defined in Equation 5-19 from :&$3-12472-3-A. UE = Engineering uncertainty factor of 1.03.

7KLVXQFHUWDLQW\LVFDOFXODWHGDQGDSSOLHGDXWRPDWLFDOO\E\WKH3DMS.

,IWKH3'06LVQRWIXQFWLRQDOthe core power distribution measurement uncertainty (UFQ) to be applied to FQ(Z) shall be calculated by:

UFQ = UQU * UE

where:

UQU = Base FQ measurement uncertainty of 1.05. UE = Engineering uncertainty factor of 1.03.

7KHXQFHUWDLQW\YDOXHVZLWKWKH3'06QRWIXQFWLRQDOZLOOEHVSHFLILHGLQWKH6HTXR\DK COLR.

2) For the Sequoyah units 1 and 2, unit-specific thermocouple uncertainty parameters will be determined using data collected during the initial power ascension of each fuel cycle. The core design does not differ sufficiently from those used in the uncertainty HYDOXDWLRQRI:&$3-12472-3-A to KDYHDVLJQLILFDQWLPSDFWRQWKH:&$3-12472-3-A database.

3'06UHTXLUHVLQIRUPDWLRQRQFXUUHQWSODQWDQGFRUHFRQGLWLRQVWRGHWHUPLQHWKHFRUH power distribution using the core peaking factor measurement and measurement uncertainty methodology described in :&$3-12472-3-A. The core and plant condition information is used as input to the continuous core power distribution measurement

Enclosure 1 Attachment 8 - 18 of 45 software that continuously and automatically determines the current peaking factor values. The core power distribution calculation software provides the measured peaking factor values at nominal one-minute intervals.

FRU3'06WRDFFXUDWHO\GHWHUPLQHWKHFRUHSHDNLQJIDFWRUYDOXHWKHFRQWLQXRXVFRUH power distribution measurement software requires accurate information measured by the plant instrumentation (e.g., current reactor power level, average reactor vessel inlet temperature, control bank positions, power range detector calibrated voltage values, measured temperatures from a minimum number and distribution of operable CETCs).

The individual uncertainty components in the BEACON monitored power peaking are GLVFXVVHGLQGHWDLOLQ:&$3-12472-3-A, Section 5.7. These components are grouped into three categories, (i.e., a) generic components, b) plant/cycle specific components, and c) input related to the plant operating conditions). The core instrumentation, in particular, can have different characteristics from plant to plant and cycle to cycle. Therefore, the uncertainties are generated on a plant-specific basis for each cycle. $GGLWLRQDOO\3'06FRQWLQXRXVO\XSGDWHVWKHXQFHUWainty depending on the reactor operating conditions and the time since the last calibration constant update. The equations and constants to be used to determine the applicable measurement uncertainties to be applied to the core peaking factors determined E\3'06LQWKHHYHQW WKDW3'06LVLQRSHUDEOHDUHGHILQHGabove.

For eDFKSODQWF\FOHVSHFLILFDSSOLFDWLRQRI3'06, the reload design and plant/cycle specific information (e.g., COLR information, instrumentation data, RCCA data) is updated. This process also generates the cycle-VSHFLILF3'06FRQVWDQWV LH reference model), which includes the initial calculated calibration information.

3) The BEACON topical report Technical Specifications are not applicable to this amendment request. The only changes to the Sequoyah Technical Specifications are to replace various references to the movable incore detectors with core power distribution measurement information in Technical Specifications 3.1.7, 3.2.4, and 3.3.1. The 3'06 will be used to perform the required functions in those Technical Specifications when the 3'06LVIXQFWLRQDO:KHQQRWIXQFWLRQDOWKHPRYDEOHLQFRUHGHWHFWRUVZLOOEHXVHG Consistent with previous licensing precedents, the functionality requirements for the 3'06ZLOOEHOocated in the Sequoyah Technical Requirements Manual (TRM).

Enclosure 1 Attachment 8 - 19 of 45 WCAP--P-$$GGHQGXP-A, RHYLVLRQ³%($&21TM &RUH0RQLWRULQJDQG 2SHUDWLRQ6XSSRUW6\VWHP$GGHQGXP´6HSWHPEHU

Applicable Technical Specifications for BEACON-760&RUH3RZHUDistribution Measurement:

 5RG3RVLWLRQ,QGLFDWLRQ  4XDGUDQW3RZHU7LOW5DWLR 3.3.1 (Reactor Trip System Instrumentation)

Limitation and Condition

“7KH15&VWDIIKDVUHYLHZHGWKH:HVWLQJKRXVHVXEPLWWDO75:&$3-12472-3:&$3-12472- 13 Addendum 4, Revision 0, and found the updated thermocouple methodology, the use of approved Westinghouse design model methodology, and the use of higher order polynomial fits for FID [fixed in-core detector] uncertainties provided in the TR acceptable. The basis for acceptance is due to the provided qualitative and quantitative technical material contained in the TR.”

Compliance

The use of BEACON at the Sequoyah units will meet Addendum 4, including the use of the 1(;86$1&PRGHO

Enclosure 1 Attachment 8 - 20 of 45 WCAP--P-A, ³9$17$*()XHO$VVHPEO\5HIHUHQFH&RUH5HSRUW´$SULO

Applicable Technical Specifications:

5.6.3.b COLR Methodology (methodology for AFD limits and heat flux hot channel factor)

7-1-91 NRC Safety Evaluation - From the SE Conclusions:

Limitation and Condition #1

“The staff has reviewed the Westinghouse VANTAGE+ fuel design and mechanical analyses report described in Reference 1 and find it acceptable for licensing applications up to a rod-average burnup level of 60 MWd/KgM. Our findings on applications beyond a rod-average burnup of 60 MWd/kgM which is addressed in Appendix B of Reference 1, will be reported separately.”

Compliance

Not applicable to this license amendment request. This limit was increased to a lead rod average burnup of 6*:G078IRU:HVWLQJKRXVHIXHO :&$3-10444-3-$DQG:&$3-12610- 3-$ SURYLGHGWKDW3$' :&$3-15063-3-A) or later fuel performance codes were used 15&OHWWHUIURP-'3HUDOWDWR:HVWLQJKRXVHGDWHGMay 25 2006, “Approval for Increase in Licensing Burnup Limit to 62,000 MWD/MTU (TAC NO. MD1486),” ADAMS Accession Number ML061420458). 3$'DQGthe FSLOCA EM have been approved for use up to a lead rod average burnup of 62 GWd/MTU for all approved types of cladding.

Limitation and Condition #2

“This approval is subject to confirmation of expected fuel performance in the fuel surveillance program described in Section 6.0 >31/7(5@of the attached evaluation. lt is expected that any adverse surveillance information with respect to ZIRLO corrosion or hydrogen pickup or other properties considered in the design evaluation will be reported to the NRC.”

Compliance

See the discussion of /LPLWDWLRQDQG&RQGLWLRQXQGHU:&$3-12610-3-A &(13'-404-3-A, Addendum 1-A and Sections 7.4.5 and 7.4.6 of the 3AD5 WRSLFDOUHSRUW :&$3-17642-3-A).

Limitation and Condition #3

“This approval does not include the LOCA evaluation methods described in Appendices F and *RI:&$3-12610.”

Compliance

Not applicable to this license amendment request. The LOCA analysis for Sequoyah Units 1 and 2 was performed in accordance with the FSLOCA EM WRSLFDOUHSRUW :&$3-16996-3-A Revision 1).

10-9-91 NRC Safety Evaluation - From the Enclosure 1 SE Conclusions:

Enclosure 1 Attachment 8 - 21 of 45

Limitation and Condition #1

“We find the modifications to the use of the WHVWLQJKRXVH1275803/2&7$-IV small break evaluation model to analyze VANTAGE+ fuel with ZIRLO cladding and thimble tubes in FRQIRUPDQFHZLWKWKHUHTXLUHPHQWVRI&)53DUW Appendix K and therefore acceptable. The limitations and conditions identified iQSUHYLRXV6(5VIRUWKH1275803/2&7$āIV small break LOCA model continue to apply to this usage of the model.”

Compliance

Not applicable to this license amendment request. The small break LOCA analysis for Sequoyah Units 1 and 2 was performed in accordance with the FSLOCA EM topical report :&$3-16996-3-A Revision 1).

Limitation and Condition #2

“Although ZIRLO is similar to ZIRCALOY, the criteria of acceptance (10 CFR 50.44, 10 CFR 50.46 and 10 CFR 50, Appendix K) cited in the evaluation are specifically identified as appropriate for ZIRCALOY clad fuel. Thus, exemptions must be obtained to allow application of those criteria to ZlRLO-clad fuel.”

Compliance

An exemption request is included with the Sequoyah license amendment request (see Enclosure 5).

10-9-91 NRC Safety Evaluation - From the Enclosure 2 SE Conclusions:

Limitation and Condition #1

“7KHVWDIIILQGVWKDW:&$3-12610, Appendix G, describes LOCA analyses performed with acceptable methods and that results of these analyses demonstrate conformance with the FULWHULDJLYHQLQ&)5DQG&)53DUW50 Appendix K, for a reference plant. We find the criteria applicable and the analyses acceptable. This SER addresses only the reference plant and fuel designs discussed herein. Other applications must be justified.”

Compliance

Not applicable to this license amendment request. The LOCA analysis for Sequoyah Units 1 and 2 was performed in accordance with the FSLOCA EM WRSLFDOUHSRUW :&$3-16996-3-A Revision 1).

Limitation and Condition #2

Although ZIRLO is similar to Zircaloy, the criteria of acceptance {10 CFR 50.46 and 10 CFR 50, Appendix K} cited in the evaluation are specifically identified as appropriate for Zircaloy-clad fuel. Thus, exemptions must be obtained to allow application of those criteria to ZIRLO-clad fuel. Similarly, exemptions must be obtained to allow applicat1on of 10 CFR 50.44 dealing with hydrogen generation and combustible gas control to plants with ZIRLO-clad fuel.”

Enclosure 1 Attachment 8 - 22 of 45 Compliance

An exemption request is included with the Sequoyah license amendment request (see Enclosure 5).

9-15-94 NRC Safety Evaluation – From the SE Conclusions:

Limitation and Condition

“The staff has reviewed the W fuel rod growth model descrLEHGLQ:&$3-12610, Appendix B, Addendum 1 and finds it acceptable for licensing applications up to 60,000 MWD/MTU rod average.”

Compliance

Not applicable to this license amendment request. This limit was increased to a lead rod DYHUDJHEXUQXSRI*:G078IRU:HVWLQJKRXVHIXHO :&$3-10444-3-$DQG:&$3-12610- 3-$ SURYLGHGWKDW3$' :&$3-15063-3-A) or later fuel performance codes were used 15&OHWWHUIURP-'3HUDOWDWR:HVWLQJKRXVHGDted May 25 2006, “Approval for Increase in Licensing Burnup Limit to 62,000 MWD/MTU (TAC NO. MD1486),” ADAMS Accession Number ML061420458). 3$'DQGthe FSLOCA EM have been approved for use up to a lead rod average burnup of 62 GWd/MTU for all approved types of cladding.

Enclosure 1 Attachment 8 - 23 of 45 WCAP--P-A & CENPD--P-$$GGHQGXP-$³2SWLPL]HG=,5/2TM´-XO\

Applicable Technical Specifications:

4.2.1 (Optimized ZIRLOTM cladding) 5.6.3.b COLR Methodology (methodology for AFD limits and heat flux hot channel factor)

Limitation and Condition #1

³8QWLOUXOHPDNLQJWR&)53DUWDGGUHVVLQJOptimized ZIRLOTM has been completed, implementation of Optimized ZIRLOTM fuel clad requires an exemption from 10 CFR 50.46 and &)53DUW$SSHQGL[.”

Compliance

An exemption request is included in the Sequoyah RTSR license amendment submittal (see Enclosure 5).

Limitation and Condition #2

Revised by NRC letter from D. C. Morey to Westinghouse dated May 8, 2019, “Modification of the Condition and Limitation 2 of the U.S. Nuclear Regulatory Commission Safety Evaluation Report for Westinghouse Electric Company Topical Report :&$3-12610-3-$ &(13'-404-3- A, Addendum 1-A, “Optimized ZIRLOTM, (3,'/-2019-723-0004),” ADAMS Accession Number ML19119A127, to read:

“For Westinghouse fuel designs, the fuel rod average burnup limit for this approval remains at the currently established limit of 62 GWd/MTU. For the CE16NGF assembly design, the fuel rod average burnup limit for this approval is 62 GWd/MTU when analyzed with NRC approved analytical methods which properly accounts for TCD. This includes licensees that use penalties and allowances to account for TCD that have been explicitly approved by the NRC. For CE16NGF without NRC approved analytical methods which properly accounts for TCD and all remaining CE fuel designs, the fuel rod average burnup limit for this approval remains at the currently established limit of 60 GWd/MTU.”

Compliance

The lead rod average burnup limit for this license amendment request is 62 GWd/MTU. Sequoyah will transition to Westinghouse RFA-2 fuel.

Limitation and Condition #3

“The maximum fuel rod waterside corrosion, as predicted by the best-estimate model, will [satisfy proprietary limits (included in the topical report and proprietary version of the NRC Safety Evaluation] of hydrides for all locations of the fuel rod.”

Enclosure 1 Attachment 8 - 24 of 45 Compliance

The maximum fuel rod waterside corrosion and hydrogen pickup will be limited to the criteria specified in Limitation and Condition #3. The best estimate maximum predicted oxide thickness will remain below 100 microns. Hydrogen pickup will be limited to the proprietary limit approved in the topical report. The methodologies used for the normal reload process under :&$3-9272-3-A will ensure that the maximum fuel rod waterside corrosion limits will be confirmed to be less than the specified limits for all fuel rod locations as a normal part of the reload design process.

Limitation and Condition #4

“All the conditions listed in previous NRC SE approvals for methodologies used for standard ZIRLO and Zircaloy-4 fuel analysis will continue to be met, except that the use of Optimized ZIRLOTM cladding in addition to standard ZIRLO and Zircaloy-4 cladding is now approved.”

Compliance

All conditions for previously approved cladding-related methodologies, listed in the proposed changes to Sequoyah Technical Specification 5.6.3.b, will continue to be met and confirmed as SDUWRIWKHQRUPDOUHORDGGHVLJQSURFHVVGLVFXVVHGLQ:&$3-9272-3-A. See also the GLVFXVVLRQRIWKH/LPLWDWLRQVDQG&RQGLWLRQVIRU:&$3-12610-3-A.

Limitation and Condition #5

“All methodologies will be used only within the range for which ZIRLOTM and Optimized ZIRLOTM data were acceptable and for which the verifications discussed in Addendum 1 and responses to RAls were performed.”

Compliance

All conditions for previously approved cladding-related methodologies, listed in the proposed changes to Sequoyah Technical Specification 5.6.3.b, will continue to be met within the range of acceptable data and confirmed as part of the normal reload design process discussed in :&$3-9272-3-A. 6HHDOVRWKHGLVFXVVLRQRIWKH/LPLWDWLRQVDQG&RQGLWLRQVIRU:&$3-12610- 3-A.

Limitation and Condition #6

“The licensee is required to 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] [Letter from J. A. Gresham (Westinghouse) to U.S. Nuclear Regulatory Commission, "Westinghouse Responses to NRC Request for Additional Information (RAls) on Optimized ZIRLOTM Topical - $GGHQGXPWR:&$3-12610-3-A," LTR-NRC-04-44, August 4, 2004 (ADAMS Accession No. ML042240408)]:

a. Optimized ZIRLOTM LTA data from Byron, Calvert Cliffs, Catawba, and Millstone. i. Visual ii. Oxidation of fuel rods

Enclosure 1 Attachment 8 - 25 of 45 LLL3URILORPHWU\ iv. Fuel rod length v. Fuel assembly length

b. Using the standard and Optimized ZIRLOTM database including the most recent LTA data, confirm applicability with currently approved fuel performance models (e.g., measured vs. predicted).

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

Compliance

Limitation and Condition 6 has been satisfied by letter from NRC (Kevin Hsueh) to Westinghouse (J. A. Gresham), “Satisfaction of Conditions 6 and 7 of the U.S. Nuclear Regulatory Commission Safety Evaluation for Westinghouse Electric Company Addendum 1 to :&$3-12610-3-A &(13'-404-3-A, “237,0,=('=,5/2TM,” Topical Report,” dated August 3, 2016, ADAMS Accession Number ML16173A354.

Limitation and Condition #7

“The licensee is required to ensure that Westinghouse has fulfilled the following commitment.

Westinghouse shall provide the NRG staff with a letter containing the following information (Based on the schedule described in response to RAI #11 [Reference 3]):

a. Vogtle growth and creep data summary reports.

b. Using the standard ZIRLOTM and Optimized ZIRLOTM database including the most recent Vogtle data, confirm applicability with currently approved fuel performance models (e.g., level of conservatism in W rod pressure analysis, measured vs. predicted, predicted minus measured vs. tensile and compressive stress).

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

Enclosure 1 Attachment 8 - 26 of 45 Compliance

Limitation and Condition 7 has been satisfied by letter from NRC (Kevin Hsueh) to Westinghouse (J. A. Gresham), “Satisfaction of Conditions 6 and 7 of the U.S. Nuclear Regulatory Commission Safety Evaluation for Westinghouse Electric Company Addendum 1 to :&$3-12610-3-$ &(13'-404-3-A, “237,0,=(' ZIRLOTM,” Topical Report,” dated August 3, 2016, ADAMS Accession Number ML16173A354.

Limitation and Condition #8

“The licensee shall account for the relative differences in unirradiated strength (YS and UTS) between Optimized ZIRLOTM and standard ZIRLOTM in cladding and structural analyses until irradiated data for Optimized ZIRLOTM have been collected and provided to the NRC staff. a. For the Westinghouse fuel design analyses:

i. The measured, unirradiated Optimized ZIRLOTM strengths shall be used for BOL analyses.

ii. Between BOL up to a radiation fluence of 3.0 x 1021 n/cm2 (E> 1 MeV), pseudo- irradiated Optimized ZIRLOTM strength set equal to linear interpolation between the following two strength level points: At zero fluence, strength of Optimized ZIRLOTM equal to measured strength of Optimized ZIRLOTM and at a fluence of 3.0 x 1021 n/cm2 (E>1 MeV), irradiated strength of standard ZIRLOTM at the fluence of 3.0 x 1021 n/cm2 (E>1 MeV) minus 3 ksi.

iii. During subsequent irradiation from 3.0 x 1021 n/cm2 up to 12 x 1021 n/cm2, the differences in strength (the difference at a fluence of 3 x 1021 n/cm2 due to tin content) shall be decreased linearly such that the pseudo-irradiated Optimized ZIRLOTM strengths will saturate at the same properties as standard ZIRLOTM at 12 x 1021 n/cm2 . b. For the CE fuel design analyses, the measured, unirradiated Optimized ZIRLOTM strengths shall be used for all fluence levels (consistent with previously approved methods).

Compliance

Limitation and Condition 8.a was addressed in Westinghouse letter LTR-NRC-15-84, “Submittal RI5HVSRQVHWR&RQGLWLRQDRIWKH6DIHW\(YDOXDWLRQ5HSRUW 6(5 RQ:&$3-12610-3-$  &(13'-404-3-A Addendum 1-A, ‘Optimized ZIRLOTM,’ 3URSULHWDU\1RQ-3URSULHWDU\ ,” dated September 29, 2015, ADAMS Accession Number ML15279A113. Based on that Westinghouse letter, the following conclusions were drawn:

“Therefore, the current Condition 8.a requirement is not consistent with the data. Instead, based on the data, the following model is proposed for Westinghouse fuel design analyses:

i. The measured, un-irradiated Optimized ZIRLOTM cladding strength shall be used for BOL analyses.

Enclosure 1 Attachment 8 - 27 of 45 ii. Between the beginning of life up to the proprietary fluence value listed in Section 6 of the attachment to LTR-NRC-15-84, cladding strength will be modeled as described in that letter for Westinghouse fuel design analysis. iii. During subsequent irradiation beyond that level, the irradiated Optimized ZIRLOTM material strengths are the same as the designed irradiated standard ZIRLO® cladding strengths.”

The fuel analysis of Optimized ZIRLOTM clad rods will be confirmed to meet the requirements of LTR-NRC-15-84 as part of the normal reload design process discussed in WCAP-9272-P-A.

Limitation and Condition 8.b is not applicable to the Sequoyah units given the proposed loading of transition cores with Westinghouse RFA-2 fuel.

Limitation and Condition #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 material properties.”

Compliance

Not applicable to this license amendment request. The current licensing basis for the Sequoyah units does not include LOCBART or STRIKIN-II. The LOCA analyses for the Sequoyah RTSR were performed using the FSLOCA EM (see the discussion of WCAP-16996-P-A Revision 1).

Limitation and Condition #10

Due to the absence of high temperature oxidation data for Optimized ZIRLOTM, the Westinghouse coolability limit on PCT during the locked rotor event shall be [less than the proprietary limit included in the proprietary versions of the topical report and NRC Safety Evaluation].

Compliance

For the implementation of Optimized ZIRLOTM fuel cladding, the PCT calculated for the locked rotor event is 1852F, which is considerably less than the limit specified in Limitation and Condition #10. For subsequent core reload designs, the calculated PCT will be confirmed as part of the normal reload design process conducted per WCAP-9272-P-A.

Enclosure 1 Attachment 8 - 28 of 45 WCAP--$³*HQHULF0HWKRGRORJ\IRU([SDQGHG&RUH2SHUDWLQJ/LPLWV5HSRUW´ -DQXDU\

Applicable Technical Specifications:

2.1.1.1 (Relocation of Safety Limits Figure to the COLR and new DNB Safety Limit)  5HORFDWLRQRI2YHUWHPSHUDWXUH¨7DQG2YHUSRZHU¨7.DQGIJ WLPHGHOD\ setpoint values to the COLR) 3.4.1 (Relocation of pressurizer pressure, RCS average temperature, and RCS total flow values to the COLR)

The following statements in Section 4 of the NRC SE are staff conclusions, but are treated as Limitations and Conditions due to the embedded requirements in them.

Limitation and Condition #1

“Revise TS 3.4.1 of NUREG-5&63UHVVXUH7HPSHUDWXUHDQG)ORZ'HSDUWXUH from Nucleate Boiling (DNB) Limits, to relocate the pressurizer pressure, RCS average temperature (T-avg), and RCS total flow rate values to the COLR. The minimum limit for total flow based on that used in the reference safety analysis will be retained in the TS.”

Compliance

The thermal design flow (revised to 360,000 gpm total for four loops as part of the RTSR project) will be added to Technical Specification 3.4.1. This is the minimum RCS total flow rate corresponding to the maximum approved steam generator tube plugging limit. The other DNB limits will be relocated to the COLR per TSTF-339-A Revision 2.

Limitation and Condition #2 “Revise TS Table 3.3.1-1 of NUREG-1431, Reactor Trip System Instrumentation, to relocate the overtemperature ¨T and overpower ¨T (K) constant values and dynamic compensation (IJ) values, and the breakpoint and slope values for the f(¨l) penalty function(s) to the COLR.”

Compliance These values are relocated to the COLR per TSTF-339-A Revision 2.

Limitation and Condition #3 “Revise TS 2.1 Safety Limits of NUREG-1431, and the associated bases to relocate Figure 2.1.1-1 to the COLR and replace it with more specific requirements regarding the safety limits (i.e., the fuel DNB design basis and the fuel centerline melt design basis). The NRC-approved methodology used to derive the parameters in the figure will be referenced in the Reporting Requirements section of the TS.”

Compliance The requirement for compliance with the Safety Limits Figure will be retained in Technical Specification 2.1.1; however, the actual Figure 2.1.1-1 itself will be relocated to the COLR. Technical Specification 5.6.3.b has been revised per the proposed Technical Specification markups to include the approved analytical methods used to determine the core operating limits.

Enclosure 1 Attachment 8 - 29 of 45 WCAP--P-A³9,35(-0RGHOLQJDQG4XDOLILFDWLRQIRU3UHVVXUL]HG:DWHU5HDFWRU Non-LOCA Thermal-+\GUDXOLF6DIHW\$QDO\VLV´2FWREHU

Applicable Technical Specifications:

2.1.1.1 (Relocation of Safety Limits Figure to the COLR and new DNB Safety Limit) 5.6.3.b COLR Methodology (methodology for DNB Safety Limit, Nuclear Enthalpy Rise Hot Channel Factor, and TS 3.4.1 DNB Limits)

Limitation and Condition #1

“Selection of the appropriate CHF correlation, DNBR limit, engineered hot channel factors for enthalpy rise and other fuel-dependent parameters for a specific plant application should be justified with each submittal.”

Compliance

The WRB-2M correlation with a 95/95 correlation limit of 1.14 DSSURYHGLQ:&$3-15025-3-A was XVHGLQWKH9,35(-W DNBR analyses for at-power events and for analyses applicable to the region above the first mixing vane grid. 9,35(-:LVWKH:HVWLQJKRXVHYHUVLRQRI(35,¶V 9,35(-01 code with NRC-approved input options, heat transfer models, and proprietary critical heat flux correlations added. The ABB-NV and :/23'1%FRUUHODWLRQV(approved in :&$3-14565-3-A Addenda 1-A and 2-3-A) were used when the WRB-2M DNB correlation is not applicable. The ABB-NV and :/23'1%FRUUHODWLRQOLPLWVXVHGLQWKH'1%5FDOFXODWLRQV are 1.13 and 1.18, respectively. The Sequoyah RTSR utilizes the Westinghouse 17x17 RFA-2 fuel design, starting with a mixed core of Framatome 17x+73IXHODQG:HVWLQJKRXVH5)$-2 fuel. The effect of mixed cores on departure from nucleate boiling (DNB) analyses is discussed above under W&$3-11837-3-A. 7KH+73IXHOXWLOL]HVDORZHU)ǻ+WRSUHFOXGHWKHQHHGWR penalize the DNB which maintains the current safety analysis. The Westinghouse fuel utilizes a direct DNB penalty applied by the thermal-hydraulic (T/H) design group. As a UHVXOWWKH)ǻ+ WHFKQLFDOVSHFLILFDWLRQZLOOEHPRGLILHGDQGWKH)UDPDWRPH+73IXHOZLOOEHPRQLWRUHGWRDPRUH UHVWULFWLYHYDOXHRI)ǻ+WKDQWKH:HVWLQJKRXVH5)$-2 fuel.

Limitation and Condition #2

“Reactor core boundary conditions determined using other computer codes are generally input LQWR9,35(IRUUHDFWRUWUDQVLHQWDQDO\VHV These inputs include core inlet coolant flow and enthalpy, core average power, power shape and nuclear peaking factors. These inputs should be justified as conservative foUHDFKXVHRI9,35(”

Enclosure 1 Attachment 8 - 30 of 45 Compliance

7KHFRUHERXQGDU\FRQGLWLRQVXVHGLQWKH9,35(-W DNBR calculations for the RFA-2 fuel transition are generated from NRC-approved codes and analysis methodologies. Table 7.1-1 summarizes the thermal-hydraulic (T/H) design parameters for Sequoyah Units 1 and 2 that were used in this analysis. The T/H design parameters remain the same as those presented in the Sequoyah Units 1 and 2 Updated Final Safety Analysis Report, with the following exceptions:

x Thermal Design Flow is increased from 87,000 gpm/loop to 90,000 gpm/loop. N x A 5 percent F ǻ+ reduction (from 1.70 to 1.61) will be applied to the Framatome +73IXHO during the transition core cycles. x The FQ surveillance limit will be reduced from 2.65 to 2.62 until the resident Framatome +73IXHOKDVEHHQIXOO\UHSODFHGZLWK:HVWLQJKRXVH5)$-2 fuel.

All current UFSAR T/H design criteria are satisfied. Continued applicability of the core boundary FRQGLWLRQVDV9,35(-W input will be verified on a cycle-by-cycle basis using the reload methodology described in :&$3-9272-3-A.

Enclosure 1 Attachment 8 - 31 of 45 7DEOH-6HTXR\DK8QLWVDQG7KHUPDO-+\GUDXOLF Design Parameters Thermal-+\GUDXOLF'HVLJQ 7+$QDO\VLV Parameters 9DOXH Reactor Core Heat Output, MWt 3455 Reactor Core Heat Output, 106 Btu/hr 11,789 Heat Generated in Fuel, % 97.4 3UHVVXUL]HU3UHVVXUH1RPLQDOSVLD 2250 Hot Full-3RZHU1RPLQDO&RRODQW&RQGLWLRQV(2) (uncertainties and biases not included) N (1) 5DGLDO3RZHU'LVWULEXWLRQ) ¨+ 1.635 [1+0.3(1-3 @

Vessel Inlet Thermal Design Flow Rate (including bypass) 6 x 10 lbm/hr 136.1 x gpm 360,000 Core Flow Rate (excluding bypass(3)) 6 x 10 lbm/hr 121.1 x gpm 320,400 Core Flow Area, ft2 51.1 6 2 Core Inlet Mass Flux, 10 lbm/hr-ft 2.37 Nominal Vessel/Core Inlet Temperature, °F 545.9 Vessel Average Temperature, °F 578.2 Core Average Temperature, °F 583.7 Vessel Outlet Temperature, °F 610.6 Core Outlet Temperature, °F 617.6 Average Temperature Rise in Vessel, °F 64.7 Average Temperature Rise in Core, °F 71.7 Heat Transfer x Active Heat Transfer Surface Area(4), ft2 59,741 x Average Heat Flux(4), Btu/hr-ft2 197,335 x $YHUDJH/LQHDU3RZHU(4), kW/ft 5.51 x 3HDN/LQHDU3RZHUIRU1RUPDO2SHUDWLRQ(4,5), 14.60 kW/ft 3UHVVXUH'URS$FURVV&RUHSVL(6) 19.39 Notes: 1. 3 thermal power/rated power 2. Based on thermal design flow of 278,400 gpm. 3. Design bypass flow of 11.0 percent was excluded. 4. Based on densified heated length of 143.7 inches.

5. A value of FQ = 2.65 was used to calculate the peak linear power for normal operation. 6. The pressure drop is based on a vessel thermal design flow of 278,400 gpm.

Enclosure 1 Attachment 8 - 32 of 45 Limitation and Condition #3

“The NRC staff’VJHQHULF6(5IRU9,35( 5HI >6DIHW\(YDOXDWLRQ5HSRUWRQ(35,13-2511- &&09,35(-01] set requirements for use of new CHF FRUUHODWLRQVZLWK9,35( Westinghouse has met these requirements for using the WRB-1, WRB-2 and WRB-2M correlations. The DNBR limit for WRB-1 and WRB-2 is 1.17. The WRB-2M correlation has a DNBR limit of 1.14. Use of other CHF correlations not currently LQFOXGHGLQ9,35(ZLOOUHTXLUHDGGLWLRQDO justification.”

Compliance

As discussed in the response to Limitation and Condition #1, the WRB-2M correlation with a 95/95 correlation limit of 1.14 (approved in :&$3-15025-3-A) ZDVXVHGLQWKH9,35(-W DNBR calculations for the RFA-2 fuel transition at Sequoyah Units 1 and 2. The ABB-NV DNBR limit DQGWKH:/23'1%5OLPLW were previously approved in DSSURYHGLQ:&$3-14565-3-A Addenda 1-A and 2-3-A IRUXVHZLWKWKH9,35(-W code.

Limitation and Condition #4

“:HVWLQJKRXVHSURSRVHVWRXVHWKH9,35(FRGHWRHYDOXDWHIXHOSHUIRUPDQFHIROORZLQJ postulated design-basis accidents, including beyond-CHF heat transfer conditions. These evaluations are necessary to evaluate the extent of core damage and to ensure that the core maintains a coolable geometry in the evaluation of certain accident scenarios. The NRC staff’s JHQHULFUHYLHZRI9,35( 5HI GLGQRWH[WHQGWRSRVW&+)FDOFXODWLRQV 9,35(GRHVQRW model the time-dependent physical changes that may occur within the fuel rods at elevated temperatures. Westinghouse proposes to use conservative input in order to account for these effects. The NRC staff requires that appropriate justification be submitted with each usage of 9,35(LQWKHSRVW-CHF region to ensure that conservative results are obtained.”

Compliance

$SSOLFDWLRQRIWKH9,35(-W code does not model the time-dependent physical changes that may occur within the fuel rods at elevated temperatures in the post-CHF (critical heat flux) region.

Enclosure 1 Attachment 8 - 33 of 45 WCAP--P-$$GGHQGXP-$5HYLVLRQ³$GGHQGXPWR:&$3-P-A 4XDOLILFDWLRQRI$%%-19&ULWLFDO+HDW)OX[&RUUHODWLRQVZLWK9,35(-&RGH´ August 

Applicable Technical Specifications:

2.1.1.1 (Relocation of Safety Limits Figure to the COLR and new DNB Safety Limit) 5.6.3.b COLR Methodology (methodology for DNB Safety Limit)

Limitation and Condition #1

³$GGHQGXPWRWKH:&$3-14565-3-$9,35(-01 model must remain consistent with that for WKH'1%GDWDDQDO\VLVGHVFULEHGLQ:&$3-14565-3-$9,35(-01.”

Compliance

7KH9,35(-:PRGHOXVHGIRUWKH5765DQDO\VHVZDVXWLOL]HGDVGHVFULEHGLQ:&$3-14565-3- A. 7KHUHTXLUHGFRQVLVWHQF\EHWZHHQWKH9,35(-W model and DNB data analysis has been maintained.

Limitation and Condition #2

“The current 95/95 DNBR limit of 1.13 [for ABB-NV] remains unchanged.”

Compliance

The ABB-NV DNBR Correlation is used for the rod withdrawal from subcritical analysis below the first mixing vane grid. The 1.13 correlation limit is used.

Limitation and Condition #3

“DNBR calculations for CE-3:5IXHOVDUHZLWKLQWKHFXUUHQWDSSOLFDEOHUDQJHGHILQHGLQ Table 2-1 of the TR.”

Compliance

Not applicable to this license amendment request. Sequoyah is transitioning from Framatome +73IXHOto Westinghouse RFA-2 fuel.

Enclosure 1 Attachment 8 - 34 of 45 WCAP--P-$$GGHQGXP-P-$5HYLVLRQ³$GGHQGXPWR:&$3--P-A ([WHQGHG$SSOLFDWLRQRI$%%-19&RUUHODWLRQDQG0RGLILHG$%%-19&RUUHODWLRQ:/23IRU 3:5/RZ3UHVVXUH$SSOLFDWLRQV´$SULO

Applicable Technical Specifications:

2.1.1.1 (Relocation of Safety Limits Figure to the COLR and new DNB Safety Limit) 5.6.3.b COLR Methodology (methodology for DNB Safety Limit)

Limitation and Condition #1 “The applicable range of the ABB-19DQG:/23FRUUHODWLRQVDUHpresented in Table 1 and Table 2, respectively, of this SE.”

Compliance The ABB-NV DNBR Correlation is used for the rod withdrawal from subcritical analysis below the first mixing vane grid. The applicability range in Table 1 of the SE is met and the 1.13 correlation limit is used. 7KH:/23'1%5&RUUHODWLRQLVXVHGIRUWKHKRW]HURSRZHUVWHDPOLQH break analysis. The applicability range in Table 2 of the SE is met and the 1.18 correlation limit is used.

Limitation and Condition #2

“The ABB-19FRUUHODWLRQDQGWKH:/23FRUUHODWLRQPXVWXVHWKHVDPH)c factor for power shape correction as used in the primary DNB correlation for a specific fuel design.”

Compliance

The FC Tong factor (also referred to as the non-uniform power shape factor) IURP:&$3-8762- 3-A, “New Westinghouse Correlation WRB-IRU3UHGLFWLQJ&ULWLFDO+HDW)OX[LQ5RG%XQGOHV with Mixing Vane Grids,” July 1984, is used with the ABB-19DQG:/23FRUUHODWLRQVDV required by Limitation and Condition #2 of the NRC Safety Evaluation.

Limitation and Condition #3 “Selection of the appropriate DNB correlation, DNBR limit, engineering hot channel factors for enthalpy rise, and other fuel-dependent parameters will be justified for each application of each correlation on a plant specific basis.”

Compliance 6HHWKHGLVFXVVLRQRI/LPLWDWLRQDQG&RQGLWLRQXQGHU:&$3-14565-3-A.

Limitation and Condition #4 “The ABB-19FRUUHODWLRQIRU:HVWLQJKRXVH3:5DSSOLFDWLRQVDQGWKH:/23FRUUHODWLRQ must be used in conjunction with the :HVWLQJKRXVHYHUVLRQRIWKH9,35(- 9,35( FRGH since the FRUUHODWLRQVZHUHMXVWLILHGDQGGHYHORSHGEDVHGRQ9,35(DQGWKHDVVRFLDWHG 9,35(PRGHOLQJ specifications.”

Compliance The ABB-19DQG:/23FRUUHODWLRQVDUHXVHGZLWK9,35(-W in the Sequoyah RTSR analyses.

Enclosure 1 Attachment 8 - 35 of 45 WCAP--P-A, “0RGLILHG:5%-&RUUHODWLRQ:5%-0IRU3UHGLFWLQJ&ULWLFDO+HDW )OX[LQ[5RG%XQGOHVZLWK0RGLILHG/3'0L[LQJ9DQH*ULGV´$SULO

Applicable Technical Specifications:

2.1.1.1 (Relocation of Safety Limits Figure to the COLR and new DNB Safety Limit) 5.6.3.b COLR Methodology (methodology for DNB Safety Limit and Nuclear Enthalpy Rise Hot Channel Factor)

Limitation and Condition #1

“Since WRB-2M was developed from test assemblies designed to simulate Modified 17x17 Vantage 5H fuel the correlation may only be used to perform evaluations for fuel of that type without further justification. Modified Vantage 5H fuel with or without modified intermediate flow mixer grids may be evaluated with WRB-2M.”

Compliance

Sequoyah plans to transition from Framatome-VXSSOLHGKLJKWKHUPDOSHUIRUPDQFH +73 IXHOWR Westinghouse 17x17 Robust Fuel Assembly-2 (RFA-2), commencing with Unit 1 Cycle 26 and Unit 2 Cycle 26. The 17x17 RFA-2 fuel for Sequoyah Units 1 and 2 includes the following features:

• Integral fuel burnable absorbers (IFBAs) • 5REXVWSURWHFWLYHJULG 53* • Standardized debris filter bottom nozzle (SDFBN) • High-burnup bottom grid • Debris mitigating long fuel rod bottom end plugs • Wet annular burnable absorbers (WABA) • Removable top nozzle (RTN) • Three ZIRLO® intermediate flow mixer (IFM) grids • Six ZIRLO RFA-2 structural mid-grids • Reduced rod bow (RRB) INCONEL® top grid • ZIRLO and Optimized ZIRLO™ high-performance fuel cladding with a coated cladding feature • Thicker-walled guide thimble and instrumentation tubes to improve fuel assembly stiffness and to address incomplete rod insertion (IRI) considerations.

The structural mid-grid design used in the RFA-2 fuel assembly is a modification of the low pressure drop mid-grid design that was accepted by the NRC for use in the VANTAGE-5-Hybrid (V5H) fuel assembly design (:&$3-10444-3-A Addendum 2-A, “VANTAGE 5H Fuel Assembly,” February 1989). The RFA-2 mid-grid design is the culmination of several changes HYDOXDWHGE\PHDQVRIWKH15&DSSURYHG)XHO&ULWHULD(YDOXDWLRQ3URFHVV )&(3  (:&$3-12488-$5HYLVLRQ³:HVWLQJKRXVH)XHO&ULWHULD(YDOXDWLRQ3URFHVV´2FWREHU . %\FRPSO\LQJZLWKWKHUHTXLUHPHQWVRI)&(3LWKDVEHHQGHPRQVWUDWHGWKDWWKHQHZPLG-grid design meets all design criteria of existing tested mid-grids that form the basis of the WRB-2M correlation database and that the WRB-2M correlation applies to the new RFA-2 mid-grid as well as the IFM grid (Westinghouse letters LTR-NRC-02-55 dated 11-13-02 and NSD-NRC-98- 5796 dated 10-13-98). As required by the )&(3WKH:HVWLQJKRXVHQRWLILFDWLRQWRWKH15&RI the RFA-2 mid-grid design modifications and the validation of the WRB-2M DNB correlation

Enclosure 1 Attachment 8 - 36 of 45 applicability to the RFA-2 mid-grid was provided in Westinghouse letter LTR-NRC-01-44 dated 12-19-01 as well as the two letters cited parenthetically above.

Some of the significant changes between 17x17 V5H and 17x17 RFA-2 fuel are delineated below:

• RFA-2 structural mid-grids, fabricated of ZIRLO, stress relief annealed (SRA), low-strain dimple with balanced vane pattern – Eliminate grid-to-rod fretting (GTRF) associated with the V5H design

• Thicker ZIRLO thimble and instrument tubes (0.020-inch wall versus 0.016 inch) – Improve incomplete rod insertion (IRI) performance by increasing the stiffness of the fuel assembly

• Introduction of three intermediate flow mixer (IFM) grids, fabricated of ZIRLO, SRA, low-strain dimple

– Improve thermal performance and improve IRI performance due to added stiffness

• 5REXVW3URWHFWLYH*ULG 53* – Reduce the probability of cracking and dimple/ligament separation previously observed at multiple sites

• Standardized debris filter bottom nozzle (SDFBN) – Improve debris mitigation

• Integral fuel burnable absorber (IFBA) rods

• ZIRLO and Optimized ZIRLO high performance fuel rod cladding with a coated cladding feature – Improve cladding corrosion resistance and debris resistance

The other significant mechanical features of the 17x17 RFA-2 fuel design not noted above are as follows:

• Removable top nozzle (RTN) • Reduced rod bow (RRB) Alloy 718 top grid • High-burnup Alloy 718 bottom grid • Debris mitigating long fuel rod bottom end plugs

The RFA-2 fuel can be acceptably analyzed using WRB-2M DNBR correlation.

Enclosure 1 Attachment 8 - 37 of 45 Limitation and Condition #2

“Since WRB-2M is dependent on calculated local fluid properties these should be calculated by a computer code that has been reviewed and approved by the NRC staff for that purpose. Currently WRB-2M with a DNBR limit of 1.14 may be used with the THINC-IV computer code. 7KHXVHRI9,35(-01 by Westinghouse with WRB-2M is currently under separate review.”

Compliance

A DNBR limit of 1.14 was used for WRB-2M. 7KH15&6DIHW\(YDOXDWLRQIRU:&$3-14565-3-A Addendum 1-A (ADAMS Accession Number ML041060018) notes that the WRB-2M correlation ZDVOLFHQVHGDQGLQFRUSRUDWHGLQWR9,35(-W for Westinghouse analyses.

Limitation and Condition #3

“WRB-0PD\EHXVHGIRU3:5SODQWDQDO\VHVRIVWHDG\VWDWHDQGUHDFWRUWUDQVLHQWVRWKHU than loss of coolant accidents. Use of WRB-2M for loss of coolant accident analysis will require additional justification that the applicable NRC regulations are met and the computer code used to calculate local fuel element thermal/hydraulic properties has been approved for that purpose.”

Compliance

Not applicable to this license amendment request. The FSLOCA EM :&$3-16996-3-A Revision 1) is used for the Sequoyah RTSR LOCA analysis.

Limitation and Condition #4

“The correlation should not be used outside its range of applicability defined by the range of the test data from which it was developed. This range is listed in Table 1.”

Compliance

WRB-2M is used within the SE Table 1 range of applicability.

Enclosure 1 Attachment 8 - 38 of 45

WCAP--P-$³4XDOLILFDWLRQRIWKH7ZR-Dimensional Transport &RGH3$5$*21´ $XJXVW

Applicable Technical Specification:

5.6.3.b COLR Methodology

(methodology for Shutdown Margin, Moderator Temperature Coefficient, Shutdown Bank Insertion Limit, Control Bank Insertion Limits, Heat Flux Hot Channel Factor, Nuclear Enthalpy Rise Hot Channel Factor, Axial Flux Difference, TS 3.4.1 DNB Limits, Refueling 3RRO%RURQ&RQFHQWUDWLRQ 

Limitation and Condition #1

“7KH3$5$*21FRGHFDQEHXVHGDVDreplacement IRUWKH3+2(1,;-3ODWWLFHFRGH ZKHUHYHUWKH3+2(1,;-3FRGHis used in NRC-approved methodologies.”

Compliance

3$5$*21LVXVHGIRUWKH6HTXR\DK5765DVGLVFXVVHGLQ:&$3-16045-3-A Addendum 1-A EHORZ 1(;86$1& 

Limitation and Condition #2

“The data base is insufficient to enable the staff to reach a conclusion regarding 3$5$*21 V ability to predict depletion characteristics IRUD02;IXHled core at this time.”

Compliance

Not applicable to this license amendment request. The Sequoyah transition to RFA-2 fuel does QRWXVH02;IXHO

Enclosure 1 Attachment 8 - 39 of 45 WCAP--P-$$GGHQGXP-$³4XDOLILFDWLRQRIWKH1(;861XFOHDU Data 0HWKRGRORJ\´$XJXVW

Applicable Technical Specification:

5.6.3.b COLR Methodology (methodology for Moderator Temperature Coefficient)

Limitation and Condition

“:HVWLQJKRXVHKDVSURYLGHGDVHULHVRIDVVHVVPHQWVIRUWKH1(;86$1C code system in order to qualify the system as an NRC-approved code. While the re-parameterization within the 1(;86DSSURDFKFDSWXUHVWKHGRPLQDQWSK\VLFDOSKHQRPHQDWKH1(;86$1C code system is only approved to perform calculations on uranium-fueled, 3:5V

7KH1(;86$1C code system is limited to uranium-IXHOHG3:5DSSOLFDWLRQVDVWKHRQO\SODQW data assessments presented were for uranium-fueled 3:5V While Westinghouse has SURYLGHGFRPSDULVRQVRIWKHUHODWLYHSHUIRUPDQFHRI3$5$*2N/ANC DQG1(;86$1C for FDOFXODWLRQVZLWK02;IXHOHG3:5IXHODVVHPEOLHVWKH3$5$*2N/ANC code system was not approved for this purpose. ,QWKHDEVHQFHRIDFWXDOSODQWGDWD1(;86$1C has not been DSSURYHGIRU02;DSSOLFDWLRQV”

Compliance

1(;86$1&LVXVHGIRUWKH6HTXRyah transition to RFA-2 fuel. ,WLVQRWXVHGIRU02; applications.

Enclosure 1 Attachment 8 - 40 of 45 WCAP--P-$5HYLVLRQ³:HVWLQJKRXVH3HUIRUPDQFH$QDO\VLVDQG'HVLJQ0RGHO 3$' ´1RYHPEHU

Applicable Technical Specification:

2.1.1.2 (Fuel Centerline Temperature Safety Limit)

Limitation and Condition #4.1.a)

7KH15&VWDIIOLPLWVWKHDSSOLFDELOLW\RIWKH3$'FRGHDQGPHWKRGRORJ\IRUFODGGLQJIXHOW\SHV and reactor for the ranges that are listed below:

Cladding (Manufactured by Westinghouse)

x Zircaloy-4 (includLQJ237,1FRQYHQWLRQDO=LUFDOR\-4, and improved Zircaloy-4) cladding, x ZIRLO cladding, x Optimized ZIRLOTM [within the limitations of Section 4.1 of the NRC Safety Evaluation for :&$3-17642-3-A Revision 1]

Fuel

x Uranium U235 enrichments up to [the limit of Section 4.1 of the NRC Safety Evaluation for :&$3-17642-3-A Revision 1] x ZrB2 fuel pellet coating with B10 enrichment and thickness up to [the respective limits of 6HFWLRQRIWKH15&6DIHW\(YDOXDWLRQIRU:&$3-17642-3-A Revision 1] x Gadolinia concentrations up to [the limit of Section 4.1 of the NRC Safety Evaluation for :&$3-17642-3-A Revision 1] x Erbia concentrations up to [the limit of Section 4.1 of the NRC Safety Evaluation for :&$3-17642-3-A Revision 1] x Fuel grain sizes ranging between [the limits of Section 4.1 of the NRC Safety Evaluation IRU:&$3-17642-3-A Revision 1] x Nominal true pellet density ranging between [the limits of Section 4.1 of the NRC Safety (YDOXDWLRQIRU:&$3-17642-3-A Revision 1] of the theoretical density of UO2

Reactor

x 3:5designs using Low-Enriched Uranium (LEU) fuel loading x Rod average burnups up to 62 GWd/MTU for all approved types of cladding x Steady-state rod average linear heat generation rate and local rates up to [the respective limits of Section 4.1 of the NRC Safety (YDOXDWLRQIRU:&$3-17642-3-A Revision 1] x Transient power and associated fuel temperatures less than the melt temperature

Compliance

No exceptions are taken to the FODGGLQJIXHODQGUHDFWRUOLPLWDWLRQVLQWKH3$'DQDO\VHV performed for the RFA-2 fuel assemblies to be loaded at Sequoyah Units 1 and 2. 7KH3$' fuel performance code was used to assess the fuel rod design criteria and generate the fuel performance data (i.e., fuel temperatures, rod internal pressure, and fuel centerline melt for the respective downstream analyses). 3$'ZDVDOVRXVHGWRSURYLGHthe Westinghouse Transient Analysis (TA) group with representative fuel temperatures to demonstrate that the expected fuel

Enclosure 1 Attachment 8 - 41 of 45 temperatures associated with the )UDPDWRPH+73fuel are similar to those calculated for the RFA-2 fuel. Similar consideration for fuel temperatures was completed for prior fuel transitions (between V5H and the Framatome fuel product (see Section 5.2.2.26.4 of AREVA (Framatome) 5HSRUW$13- 13 5HYLVLRQ³6HTXR\DK+73)XHO7UDQVLWLRQ 1on-3roprietary),” June 2011 (ADAMS Accession No. ML11172A070).

7KH3$'LQSXWVwill be validated on a cycle-specific basis under the reload process performed SHU:&$3-9272-3-A.

Limitation and Condition #4.1.b)

7KHDSSOLFDWLRQRI3$'VKRXOGDWQRWLPHH[FHHGWKHIXHOPHOWLQJWHPSHUDWXUHDVFDOFXODWHGE\ 3$'GXHWRWKHODFNRISURSHUWLHVIRUPROWHQIXHOLQ3$'DQGRWKHUSURSHUWLHVVXFKDVWKHUPDO conductivity and FGR.

Compliance

The peak fuel centerline temperature Safety Limit added to the Sequoyah Units 1 and 2 Technical Specifications as Safety Limit 2.1.1.2 in this license amendment request will assure that fuel melt is precluded during conditions for normal operation and anticipated operational occurrences. To assure that there will be a low probability for fuel melt for Condition I/II operation, the fuel centerline temperature is used to calculate maximum allowable local powers that are checked as part of the Reload Safety Analysis Checklist process to mitigate fuel melting. The definition for the fuel melt has been updated based on the maximum local fuel pin FHQWHUOLQHWHPSHUDWXUHZLWKWKHDSSURYDORI3$'. The specific changes to TS 2.1.1.2 are taken from Equation 6-14 in Section 6.1.5 of :&$3-17642-3-A with consideration given to conversion factors associated with temperature and burnup units. See ADAMS Accession Number ML17338A396 for the non-proprietary version and ADAMS Accession Number ML17334A841 for the proprietary version withheld from public availability. Both versions of the approved topical report were transmitted by Westinghouse letter LTR-NRC-17-75 dated November 27, 2017 (see ADAMS Accession Number ML17334A826 for the cover letter and application for withholding).

Limitation and Condition #4.1.c)

The NRC staff did not review the [proprietary approach] that was suggested as a response to RAI-22 since there is no mention of this in the revised TR.

Compliance

Not applicable to this license amendment request.

Limitation and Condition #4.1.d)

The NRC staff has reviewed the revised TR Chapter 8 on the model and methods improvement SURFHVV 00,3 DQGWKH5$,UHVSRQVH 5HIHUHQFH IURP:HVWLQJKRXVH The NRC staff acknowledges Westinghouse response that it is no longer requesting approval of the 00,3 SURFHVVDQGDVVXFKWKH15&VWDIIGRHVQRWDSSURYHWKHVWUHDPOLQHG00,3ZKHUHE\WKH models, uncertainty bound or methods that would be changed from those described in the revised TR and the RAI responses unless Westinghouse seeks NRC review and approval.

Enclosure 1 Attachment 8 - 42 of 45 Compliance

Not applicable to this license amendment request.

Limitation and Condition #4.1.e)

Since there are many references to the requests for additional information (RAIs) and their responses throughout the SE, the NRC staff is requiring Westinghouse to include the SE, the revised TR and all the responses to the RAIs in the final accepted version (-A) of this TR on 3$' This will enable clarity and completeness.

Compliance

Not applicable to this license amendment request. The NRC accepted the “-A” version of :&$3-17642-3-A in their verification letter dated January 8, 2018 (ADAMS Accession Number 0/$ )XWXUHXSGDWHVWR3$'ZLOOEHsubmitted by Westinghouse as needed.

Enclosure 1 Attachment 8 - 43 of 45 WCAP--P-A5HYLVLRQ,PSURYHG5$2&DQG&$2&)Q 6XUYHLOODQFH7HFKQLFDO 6SHFLILFDWLRQV, )HEUXDU\

Applicable Technical Specifications:

3.2.1 (Heat Flux Hot Channel Factor) 3.2.2 (Enthalpy Rise Hot Channel Factor) 5.6.3.b COLR Methodology (methodology for control bank insertion limits. heat flux hot channel factor, AFD limits)

Limitation and Condition #1, Use of A;< and AQ

“As discussed in Section 4.1.1 of this SE, the use of Methods 1 and 2 are acceptable for calculating A;< and AQ when performing RAOC and CAOC W(Z) surveillances, subject to the following limitations:

1. The NRC-approved methods provided in the response to RAI 15.b must be used to perform the surveillance-specific A;< or AQ calculations. Newer methods with similar capabilities may be considered acceptable provided the NRC staff specifically approves them for calculating A;< and AQ factors.

2. The depletion calculation used to determine the numerator and denominator of the A;< or AQ factor must be performed similarly to the original design calculation, as described in the response to RAI 15.c.

3. The use of Method 1 for calculating AQ is only acceptable subject to the constraints discussed in the response to RAI 15.a. The surveillance Axial Offset must be within W 1.5-percent of the target AO, and there must be assurance that the limiting FQ (Z) location does not lie within a rodded elevation at the time of surveillance. Note that the use of Method 1 remains acceptable when surveillance-specific W(Z) functions are used.”

Compliance

1. TVA will use NRC-approved methods including those listed in the response to RAI 15.b (OG-18-35 Enclosure 1 GDWHG)HEUXDU\LQ$SSHQGL[*RI:&$3-17661-3-A Revision 1). Newer methods with similar capabilities may be used if the NRC specifically approves them for the A;<calculation. The AQ calculation is only applicable to constant axial offset control (CAOC) plants; Sequoyah will use relaxed axial offset control (RAOC) (A;<).

2. TVA will perform depletion calculations to determine the numerator and denominator of the A;< factor similarly to the original design calculations, that is, either with the BEACONTM core monitoring system without using nodal calibration factors, or with Advanced Nodal Code using the same nuclear model and depletion basis used to generate the original T(Z) function. The AQ calculation is only applicable to CAOC plants; Sequoyah will use RAOC (A;<).

3. This limitation applies to CAOC TS only and, thus does not apply to Sequoyah.

Enclosure 1 Attachment 8 - 44 of 45

Limitation and Condition #23RZHU/HYHO5HGXFWLRQWR3HUFHQW573

“As noted in Section 4.3.2 of this SE, the use of 50 percent as the final power level reduction in the event of failed FQ surveillance is not included in the TS, but rather in the BASES and in the COLR. As such, this final power level, 50 percent, must be implemented on a plant-specific basis and included in COLR input generated using this methodology, in order to use this TR.”

Compliance

TVA will implement a final power level of 50 percent in the event of a failed FQ surveillance. This will be on a plant-specific basis and included in COLR input generated using this methodology upon implementing the License Amendment that allows adoption of the topical report.

Enclosure 1 Attachment 8 - 45 of 45 Enclosure 1

Evaluation of the Transition to Westinghouse RFA-2 Fuel

ATTACHMENT 9

Justification for Permanent Removal of Units 1 and 2 RCCA H08

CNL-20-014 Westinghouse Non-Proprietary Class 3 Attachment 9

Justification for Permanent Removal of RCCA H08 from Sequoyah Unit 1 and Unit 2

1.0 Summary Description This evaluation supports a request to amend Renewed Facility Operating License DPR-77 for Sequoyah Nuclear Plant, Unit 1 (SQN1) and Renewed Facility Operating License DPR-79 for Sequoyah Nuclear Plant, Unit 2 (SQN2), by revising Technical Specification (TS) 4.2.2, “Control Rod Assemblies,” to require the cores to contain 52 full-length control rod assemblies with no full-length control rod assembly in core location H-08. This request will permit the SQN1 and SQN2 cores to contain 52 full-length control rods with no full-length control rod in core location H-08, in lieu of the current requirement of 53 full-length control rods. Options were evaluated for repairing or replacing Control Rod H-08 as an alternative to operating with Control Rod H-08 permanently removed from SQN1 and SQN2 as requested herein and concluded that the consequences and uncertainties associated with a Control Rod Drive Mechanism (CRDM) repair or replacement are significant. Repairing or replacing the H-08 CRDM would require the use of specialized remote tooling and processes that do not currently exist and would necessitate cutting and welding on the Reactor Coolant System (RCS) pressure boundary. As discussed in this License Amendment Request (LAR), future reactor cores with 52 control rods that remain can be designed within the criteria established in the current Sequoyah Updated Final Safety Analysis Report (UFSAR) Chapter 15 accident analyses and associated safety margins as modified to support the fuel transition to Westinghouse RFA-2 fuel. Given these conclusions, the most prudent course of action is to continue safely operating Sequoyah Unit 1 and Unit 2 with Control Rod H-08 permanently removed.

2.0 Detailed Description

2.1 Proposed Amendment The proposed amendment would revise TS 4.2.2, “Control Rod Assemblies,” to require the Sequoyah units to operate with 52 full-length control rod assemblies with no full-length control rod assembly in core location H-08, in lieu of the requirement to contain 53 full-length control rod assemblies. The footnote, which permitted the cores to temporarily contain 52 full-length control rod assemblies with no full-length control rod assembly installed in core location H-08 will also be deleted. Supporting design changes and safety analyses discussed in this document are performed in accordance with the station design change process, core reload design process, and the licensing basis.

2.2 Control Rod H-08 Issue On August 27, 2019, at 0109 while operating at 100 percent power, the control rod in core location H-08 (H-08 control rod) unexpectedly dropped into the core, resulting in an automatic reactor trip of Sequoyah Unit 1. Testing and inspections performed during Sequoyah Unit 1 refueling outage Cycle 23 (U1R23) have determined that wear of the CRDM stationary gripper latch mechanism resulted in the inability to maintain the control rod in the fully withdrawn or nearly fully withdrawn position. Similar conditions were discovered later with Sequoyah Unit 2 during the Unit 2 refueling outage Cycle 23 (U2R23). These situations are discussed more fully in References 1 and 2.

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3.0 Technical Evaluation

3.1 System Description The Sequoyah units normally contains 53 full-length control rod assemblies divided into four control banks (Control Banks A, B, C, D) and four shutdown banks (Shutdown Banks A, B, C, D). Of the eight banks, Control Bank D is used for reactivity control during normal at-power operation. The remaining control banks are normally used for reactor startup and shutdown. The shutdown banks provide additional negative reactivity to meet shutdown margin (SDM) requirements. During MODES 1 and 2, the shutdown banks are fully withdrawn from the core in accordance with TS 3.1.5 and as specified in the Core Operating Limits Report (COLR). The H-08 control rod is part of Control Bank D and is located in the center of the core as shown in Figure 1. With the removal of the control rod in core location H-08, Unit 1 and Unit 2 will contain 52 full-length control rod assemblies as shown in the table to Figure 1. Each control rod is moved by a full-length CRDM consisting of a stationary gripper, movable gripper, and a lift pole. Three coils are installed external to the CRDMs to electromechanically manipulate the CRDM components to produce rod motion. The CRDMs are magnetic jacking type mechanisms that move the control rods within the reactor core by sequencing power to the three coils of each mechanism to produce a stepping rod motion. Rod position is achieved through a timed sequence of stationary, movable, and lift coil current. At each point in time during rod positioning, the control rod is being held by either the stationary gripper or movable grippers. Should both sets of grippers be de-energized simultaneously, the corresponding control rod would drop into the core. The primary function of the CRDMs is to insert, withdraw, or hold control rods within the core to control average core temperature and to shut down the reactor. Mechanically, each control rod location includes a guide tube, which is an assembly that houses and guides the control rod through the upper internals.

The full-length Rod Control System receives rod speed and direction signals from the Tavg control system (contained within the Distributed Control System). The automatic rod speed demand signal varies over the corresponding range of 5 to 45 inches per minute (8 to 72 steps/minute) depending on the magnitude of the error signal. The rod direction demand signal is determined by the positive or negative value of the error signal. Manual control is provided to move a control bank in or out at a prescribed fixed speed.

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Bank Identifier Number of Locations Bank Identifier Number of Locations SA 8 CA 4 SB 8 CB 8 SC 4 CC 8 SD 4 CD 8 Figure 1: Control Rod Locations

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3.2 Licensing Basis The reload safety analysis methods are not invalidated by the removal of the H-08 control rod from the core design because these methods are not dependent on a particular rod cluster control assembly (RCCA) configuration. Reload safety analysis methods and supporting computer codes remain applicable to model and evaluate the as-designed/operated configuration of the plant, and the reload methodology is not dependent upon control bank configuration. Cycle-specific reload evaluations of TS limits, safety analysis limits, and operating limits without the H-08 control rod are performed to ensure core protective and operating limits remain satisfied and safety analysis limits remain bounded. As described in Updated Final Safety Analysis Report (UFSAR) Section 4.2.3.2.1, Reactivity Control Components – Rod Cluster Control Assembly: The rod cluster control assemblies are divided into two categories: control and shutdown. The control groups compensate for reactivity changes due to variation in operating conditions of the reactor, i.e., power and temperature variations. Two criteria have been employed for selection of the control groups. First the total reactivity worth must be adequate to meet the nuclear requirements of the reactor. Second, in view of the fact that some of these rods may be partially inserted at power operation, the total power peaking factor should be low enough to ensure that the power capability is met. The control and shutdown groups provide adequate shutdown margin which is defined as the instantaneous amount of reactivity by which the reactor is subcritical or would be subcritical from its present condition assuming all full length rod cluster assemblies (shutdown and control) are fully inserted except for the single rod cluster assembly of highest reactivity worth which is assumed to be fully withdrawn. As described in UFSAR Section 4.3.2.5.2, Rod Cluster Control Assemblies: The number of Rod Cluster Control Assemblies is shown in Table 4.3.2-1. The Rod Cluster Control Assemblies are used for shutdown and control purposes to offset fast reactivity changes associated with: 1. The required shutdown margin in the hot zero power, stuck rod condition, 2. The reactivity compensation as a result of an increase in power above hot zero power (power defect including Doppler, and moderator reactivity changes), 3. Unprogrammed fluctuations in boron concentration, coolant temperatures, or xenon concentration (with rods not exceeding the allowable rod insertion limits), 4. Reactivity ramp rates resulting from load changes. The allowed full-length control bank reactivity insertion is limited at full power to maintain shutdown capability. As the power level is reduced, control rod reactivity requirements are also reduced and more rod insertion is allowed. The control bank position is monitored and the operator is notified by an alarm if the limit is approached. The determination of the insertion limit uses conservative xenon distributions and axial power shapes. In addition, the Rod Cluster Control Assembly withdrawal pattern determined from these analyses is used in determining power distribution factors and in determining the maximum worth of an inserted Rod Cluster Control Assembly ejection accident. For further discussion, refer to the Technical Specifications on Rod Insertion Limits. Power distribution, Rod Ejection and Rod Misalignment analyses are based on the arrangement of the shutdown and control groups of the Rod Cluster Control Assemblies shown in Figure 4.3.2-36. All shutdown Rod Cluster Control Assemblies are withdrawn before withdrawal of the control banks is

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initiated. In going from zero to 100 percent power, control banks [A], B, C and D are withdrawn sequentially. The limits of rod positions and further discussion on the basis for rod insertion limits are provided in the SQN Technical Specifications. The RCCA at SQN1 core location H-08 was removed for Unit 1 Cycle 24 and TS 4.2.2 was revised by issuance of Reference 1. Similarly, the RCCA at SQN2 core location H-08 was removed for Unit 2 Cycle 24 and TS 4.2.2 was revised by issuance of Reference 2.

3.3 Process for Evaluating Plant Design and Core Reload Design Impacts Using the engineering design change process, design changes to the plant are reviewed for impacts to the UFSAR, including the Chapter 15 accidents. Per the engineering design change process, the responsible engineer would request that the Nuclear Fuel and Analysis group perform an impact review on plant design changes that may affect core reload design or UFSAR Chapters 6 and 15 safety analyses. If the change affects the UFSAR Chapters 6 and 15 safety analyses, the impacts of the change are evaluated in the core reload design process to ensure UFSAR Chapter 15 safety analyses remain bounding. The Westinghouse Reload Safety Evaluation Methodology (WCAP-9272-P-A) is being integrated into the TVA design change processes through the core reload design process, which governs design control activities unique to the design of reload cores. Using this process, plant design changes are reviewed for potential impact to core parameters. The core reload design process is performed for each new fuel cycle regardless of whether there are any plant design changes that could impact the core design for that cycle. The removal of RCCA H-08 was evaluated using both the design change process and the core reload design process. The SQN1 and SQN2 Cycle 26 cores were initially designed for 53 control rods. Using the design change and core reload design processes together, TVA was able to implement the removal of RCCA H-08 safely. The need for a flow restrictor in the H-08 guide tube was identified and implemented using the plant design change process.

3.4 Evaluation of Physical Impacts

3.4.1 Physical Configuration Changes The following work activities in support of removing Control Rod H-08 have been performed: x Unlatched the control rod drive shaft from the RCCA and CRDM and completely removed the drive shaft from the reactor vessel x Removed RCCA located in core location H-08 x Installed a flow restrictor in the H-08 control rod guide tube (CRGT) x Removed H-08 control rod inputs to the Rod Position Indication (RPI) system x Modified plant computer position indication and alarm points for the H-08 control rod x Removed visual indications of rod position and rod bottom light for the H 08 control rod on the Main Control Room M-4 panel x Removed rod control system fuses for control power to the H-08 CRDM and lift cables for both control and position indication x Reprogrammed the Integrated Computer System computer to account for the H-08 control rod being removed.

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3.4.2 Thermal-Hydraulic Impacts The thermal-hydraulic reactor internal vessel evaluation is not impacted by removal of the control rod drive shaft and RCCA as long as the flow restrictor at the top of the guide tube housing is installed. The core bypass flow will remain unaffected by the installation of the flow restrictor. The hydraulic equivalence between the H-08 upper guide tube with a control rod drive shaft installed versus a flow restrictor installed ensures that there will be no impact on rod drop times at other core locations and the current rod drop time limits will continue to be met. The installation of a flow restrictor at the top of the H-08 guide tube housing maintains RCS flow characteristics through the upper internals guide tube that are hydraulically equivalent to the previous RCS flow configuration with a control rod drive shaft installed. The flow restrictor assembly is a readily- available part designed so that flow entering or exiting the upper plenum will be essentially unchanged when compared to the original guide tube housing plate design with the control rod drive shaft in place. The flow restrictor assembly is a passive device and has been used successfully in other plants (e.g., South Texas Project Unit 1, Beaver Valley Units 1 and 2, DC Cook Units 1 and 2, Farley Unit 2, Salem Units 1 and 2) after a drive shaft had been removed from a guide tube location for part-length control rod deletion. An evaluation was performed to show that RCCA H-08 removal has a very small impact in core thimble bypass flow, which remains bounded by the flow assumed in the safety analyses supporting the fuel transition.

3.4.3 Functional and Systems Engineering Impacts Per UFSAR Figure 4.3.2-36, H-08 is the location of the center core assembly, which contains an RCCA from control bank D. TVA has requested that Westinghouse evaluate analyses that may be impacted by the removal of the RCCA at location H-08. This section evaluates the impact to the functional and systems engineering area of scope which includes the following: x NSSS Design Transients x Plant Operability/Margin to Trip/Component Sizing o 10% Step Load Increase o 10% Step Load Decrease o Unit Loading & Unloading at 5% / min o 50% Load Rejection o Turbine Trip without Reactor Trip from P-9 x Low Temperature Overpressure Protection System (LTOPS)

NSSS Design Transients The following is an evaluation of the design transients for Sequoyah that were evaluated by Westinghouse for the fuel transition program as well as a qualitative assessment of the impact to the design transients with regards to the removal of the RCCA at H-08 with Westinghouse fuel. The design transients are used to analyze and evaluate the cyclic behavior of the major components, which comprise the NSSS. The NSSS design transients are described by the variations in fluid pressure, fluid temperature, and flow. Key inputs to the design transients include the NSSS design parameters (e.g., rated thermal power level, thermal design flow, full power hot and cold leg temperatures, etc.), control system setpoints (time constants, delay times, etc.), nuclear design parameters, and steam generator parameters.

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Removal of the RCCA at H-08 in control bank D impacts the control rod worth, particularly during the initial insertion from full power all rods out (ARO). The control rod worth data evaluated was developed for the transition to Westinghouse fuel and is based on a representative set of equilibrium cycles for Sequoyah Unit 1 and Unit 2. Review of the data determined that removal of the RCCA results in a slight reduction in the differential rod worth curve, particularly in the range where bank D is moving. A reduction in the differential rod worth would impact the plant response to certain NSSS design transients. Per a review of the original design transients input parameters, the modeled control rod worth remains similar and representative to the control rod worth with H-08 removed. Reasonable variations in the control rod worth, such as that observed in the data, are offset by other conservatisms in the analysis inputs and assumptions, such as modeling zero moderator temperature coefficient. Therefore, the NSSS design transients for Sequoyah that were evaluated by Westinghouse for the fuel transition program remain valid.

Plant Operability / Margin to Trip Evaluation / Component Sizing The plant operability analysis for Sequoyah demonstrated that acceptable margin is maintained to the limiting Reactor Trip System (RTS) and Engineered Safety Features Actuation System (ESFAS) functions during the design basis operational (Condition I) transients. Therefore, the nominal trip setpoints and their associated time constants were confirmed to be acceptable for plant operation. Key inputs to the analysis include NSSS design conditions, control / protection systems setpoints and time constants, pressure control component capabilities, nuclear design parameters, RCS volumes, and steam generator characteristics. The removal of the RCCA at location H-08 impacts the nuclear design parameters. Specifically, the primary concern with the removal of the RCCA is the reduction in differential rod worth (pcm/step) of control bank D, which is the first to insert from ARO conditions. Westinghouse evaluated the impact of H-08 removal for operation following the transition to Westinghouse fuel and determined that the plant response to operational transients remains sufficient such that the conclusions of the current operability analyses remains valid. Other nuclear design parameters such as delayed neutron data, Doppler coefficients, and moderator temperature coefficients are not expected to be significantly impacted by removal of the RCCA at H-08. The minor impact to these parameters is demonstrated as part of the standard reload process by the parameters remaining within current limits. Therefore, the analysis performed for the fuel transition remains valid for the permanent removal of the RCCA at position H-08.

Low Temperature Overpressure Protection System (LTOPS) Evaluation The LTOPS, also referred to as the Cold Overpressure Mitigation System (COMS), protects the reactor vessel from potentially being exposed to conditions of fast propagating brittle fracture caused by pressure transients that can occur during low temperature operation Key inputs to the LTOPS analysis include the design basis transient definitions, RCS volumes, PORV characteristics, steady state Appendix G limits, VWHDPJHQHUDWRUZDWHUPDVVHVDQGSUHVVXUHGURS ǻ3 EHWZHHQWKHpressure transmitter and the reactor vessel mid-plane. The only input potentially impacted by the proposed removal of one RCCA and operation without that 5&&$LVWKHǻ3EHWZHHQWKHSUHVVXUHWUDQVPLWWHUDQGWKHUHDFWRUYHVVHOPLG-plane. A flow restrictor that has the same hydraulic characteristics as the drive rod / upper guide tube that is being removed is planned for installation. Without thimble plugs, there will be a slightly larger flow area through the H-08 assembly since there will be no obstruction in the thimble tubes. This could result in a slight decrease to WKHWRWDOǻ3 6LQFHDODUJHUǻ3LVFRQVHUYDWLYHIRUWKHDQDO\VLVWKHUHPRYDORIWKH5&&$DW+-08 does not adversely impact the LTOPS analysis. The removal of the RCCA at H-08 does not affect the LTOPS design basis transient mitigation capabilities. The key input assumptions and limits that are used to generate the LTOPS setpoints are also

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not impacted by the removal of the RCCA at H-08. Therefore, there are no LTOPS setpoint changes needed and the current setpoints remain valid.

Conclusions This assessment concludes that the following analyses/evaluations remain valid for the permanent removal of the H-08 RCCA at Sequoyah for operation with Westinghouse fuel. x NSSS Design Transients x Plant Operability/Margin to Trip/Component Sizing o 10% Step Load Increase o 10% Step Load Decrease o Unit Loading & Unloading at 5% / min o 50% Load Rejection o Turbine Trip without Reactor Trip from P-9 x Low Temperature Overpressure Protection System

3.4.4 Seismic and Structural Impacts There is no impact on the functionality, structural integrity, or thermal hydraulic configuration of the reactor vessel upper internals with the removal of the control rod drive shaft and RCCA at core location H-08 as long as a flow restrictor is installed in its place. Therefore, there is no impact on the current reactor vessel internals analyses. UFSAR Section 3.7.3.15 discusses the CRDM housing dynamic analysis (seismic and LOCA). Removal of the control rod drive shaft reduces the overall weight of the CRDM, whereby the CRDM dynamic stress evaluation would remain bounding with removal of the control rod H-08.

3.4.5 RCS Water Volume Impact RCS volumes are calculated for boration and dilution analyses. RCS volume (not including the pressurizer) for Sequoyah in the current configuration at cold conditions is approximately 10,320 ft3. Based on available Westinghouse RCCA design drawings, the estimated total volume of the portions of the RCCA that will be removed from the RCS pressure boundary is less than 1 ft3. Since the RCS volume used in boration and dilution analyses is at least 10,320 ft3, the RCCA volume is less than 0.0097% of the total RCS volume. Therefore, the effect of removing one RCCA is considered negligible with respect to RCS total volume.

3.4.6 Reactor Vessel Mass Impacts Removal of the drive rod and RCCA will reduce the overall weight of the reactor pressure vessel system. The CRDS (136 lbs.) and RCCA (149 lbs.) have a combined dry weight of 285 pounds. The weight of the reactor vessel head used in the reactor equipment system model is approximately three hundred thousand pounds. The weight reduction, associated with the removal of one CRDS and RCCA, will have a negligible effect on the current reactor equipment system model, used in the LOCA and seismic analysis of the reactor internals.

3.4.7 Potential Long-Term Impacts The following potential impacts have been reviewed and found to have a minimum impact on safety.

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Functional and Structural Integrity Evaluation The thermal hydraulic reactor internal vessel evaluation is not impacted by removal of the control rod drive shaft (CRDS), RCCA, or lack of the thimble plugging device as long as the flow restrictor is installed in its place, since the flow restrictor is hydraulically equivalent to the control rod at location H- 08. The core bypass flow remains unaffected by the installation of the flow restrictor and lack of the thimble plugging device. Due to the hydraulic equivalence of the upper guide tube with CRDS and the upper guide tube with a flow restrictor, the installation of the flow restrictor will have no impact on the RCCA rod drop times at the other core locations and the current rod drop time Technical Specifications limit remains applicable. Removal of the drive rod and RCCA will reduce the overall weight of the reactor pressure vessel system. The CRDS and RCCA have a combined dry weight of a few hundred pounds. The weight of the reactor vessel head used in the reactor equipment system model is several hundred thousand pounds. The weight reduction associated with the removal of one CRDS and RCCA will have a negligible effect on the current reactor equipment system model used in the LOCA and seismic analysis of the reactor internals. Therefore, there will be no impact on the internals functionality and structural integrity. Hence, there is no impact on the existing reactor internals analyses and the UFSAR. There will also be no impact to the installation or removal of the upper internals during outage maintenance.

Absence or Lack of a Thimble Plugging Device The absence of a thimble plugging device at core location H-08 will not have any impact on the existing Sequoyah thermal hydraulic evaluations of the reactor vessel internals. Therefore, the absence of the thimble plugging device does not impact the hydraulic functionality of the flow restrictor at core location H-08.

Thermal Sleeve Wear The removal of the CRDS and the installation of the flow restrictor at core location H-08 will influence the corresponding reactor vessel (RV) head thermal sleeve wear at location H-08 but will not impact wear of all other thermal sleeves. Although the flow and hydraulic characteristics are not changing due to the removal of the CRDS and installation of the flow restrictor, the CRDS tends to have a damping effect on the thermal sleeve motion. Operating experience (OE) has shown that thermal sleeve locations without drive rods tend to experience an increase in both outside diameter (OD) wear and flange wear. OD thermal sleeve wear can be greatest at the unrodded locations since there is no drive rod to limit how deep the OD of the thermal sleeve can wear against the head adapter inside diameter (ID). However, OD wear tends to be more significant at unrodded thermal sleeves located radially outward from the center of the RV head. Since H-08 is located at or near the centerline of the head, the impact on OD wear is expected to be reduced. Ultrasonic thickness (UT) measurements of the sleeve wall at H-08, taken during the Spring 2015 outage at SQN1 and during the Spring 2014 outage at SQN2, show an average worn wall thickness of 0.172 inch and 0.185 inch, respectively, at Zone 1 which is the OD wear location. Using this data, a wear projection to Fall 2019 for SQN1 and Spring 2020 for SQN2 was first conducted to estimate the current condition of the sleeve. Wear projection curves, for more centrally located un-rodded sleeves, are used to estimate the remaining life of the sleeve at H-08 assuming it is operating without a drive rod. The projected wear life is greater than 60 EFPY for both units. Therefore, separation of the sleeve due to OD wear is not a concern. The ID wear does not encroach on the wall thickness at the elevation of the OD wear and as such the OD wear projections can neglect that ID wear. Once the driveshaft is removed, ID wear will no longer progress as there is no longer anything for the ID of the thermal sleeve to contact.

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Regarding flange wear, OE shows that thermal sleeves located toward the centerline of the RV head have typically had more aggressive wear as compared to sleeves located radially outward. This same pattern is true based on flange wear measurements taken in Fall 2019 for SQN1 and in Fall 2018 for SQN2. Industry OE also shows that unrodded locations also exhibit more aggressive flange wear than rodded locations. Similar to OD wear, this is expected to also be a result of hydrodynamic damping provided by the CRDS. Therefore, removal of the CRDS could significantly impact flange wear of the thermal sleeve at H-08. The flange wear measurements from Fall 2019 for SQN1 and from Fall 2018 for SQN2 show only moderate wear of the thermal sleeve flange at H-08. Therefore, it is unlikely that thermal sleeve flange wear would progress to the point of separation over the next operating cycle. Even if separation should occur as a result of OD wear or flange wear, the separated condition will not result in a condition adverse to safety. Since the drive rod is being removed from H-08, the wear at this location will not progress from the time when the CRDS is removed. However, because there was uncertainty as to the amount of wear at this location it is important to consider the potential that the wear has already progressed to the point where separation could be possible during the next cycle. If a guide funnel should become separated from the thermal sleeve at a unrodded location, the funnel would either rest on the top of the guide tube or fall to the top of the upper support plate. If resting on the top of the upper guide tube, minor wear of the top housing plate or flow restrictor could occur, but this would not impact the structural integrity or function of either of these parts. The more likely scenario, due to the highly turbulent flow, is that the guide funnel would fall to the upper support plate. The only components in this region that are thin enough to cause concern for damage are the conduits that carry the core exit thermocouple leads to the thermocouple columns. Local denting could possibly occur from the initial impacting of the separated part on the conduit. This should not affect the operation of a thermocouple. Even if the loose thermal sleeve were to somehow cause an opening in the thermocouple conduit, the opening would not be of concern. The conduit is not a pressure boundary, and no flow through the opening would occur. There is no flow communication to the outlet plenum as well that could change the overall flow communication between the upper plenum and the outlet plenum. The design of the conduits through the support columns, which house the thermocouple leads, seals off the flow communication at the tip of the thermocouple where it protrudes from the bottom end or near the bottom end (depending on the reactor design) of the support column. Also, the conduits are already filled with water that is in communication with the upper plenum water at the other end inside the thermocouple columns located in the upper plenum area. Wear at the remaining thermal sleeves is not expected to be impacted by the removal of the CRDS and installation of a flow restrictor at core location H-08. The amount of reduced flow blockage is negligible and therefore would not have a significant influence on upper head flow patterns.

Upper Internals Guide Tube, Guide Card Wear The removal of the CRDS and the installation of the flow restrictor at core location H-08 without plugging of the thimble tubes of the fuel will not influence wear of other guide tubes in the upper internals. As discussed for the thermal sleeve above, the exposed length of drive rod in the upper head is negligible in terms of the impact on upper head flow patterns. Furthermore, the installation of a flow restrictor will maintain flow resistance through the top of the upper guide tube equivalent to the flow resistance provided by the presence of a drive rod. Since the upper head flow and guide tube flow is not impacted by this change, nor is the flow-induced vibration of drive rods and control rods in the remaining guide tubes, which are key inputs to guide card wear. As such, there is no anticipated impact to guide card wear because of this change.

Flow-Induced Vibration of the Thermal Couples/Conduits The removal of the drive rod and the installation of the flow restrictor without thimble plugging devices will not influence the flow induced vibration of the core exit thermal couples, mechanical instrumentation

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remnants, or their associated conduits. As previously discussed, the upper head plenum flow and hydraulic characteristics are not changing due to the removal of the CRDS and installation of the flow restrictor without thimble plugging.

Conclusion It is concluded that the manufactured flow restrictor for the guide tube hole is hydraulically equivalent to the previous flow configuration. There is no change to the flow in the Sequoyah, Unit 1 and Unit 2, upper head region. The flow restrictor is structurally adequate. There is no potential interference of an installed guide tube flow restrictor and a thermal sleeve at core location H-08. There is no impact on the CRDM or internals functionality and structural integrity from the CRDS and RCCA removal, the flow restrictor installation, and without a thimble plugging device at core location H-08. Hence, there is no impact on existing CRDM or reactor internals analyses, the UFSAR and downstream groups that use input from reactor internals group. These physical changes have been reviewed and approved by SQN engineering using TVA procedures for design changes. No further changes to the facility are necessary to operate with the RCCA removed at core location H-08.

3.5 Evaluation of Core Reload Design Impacts The NRC-approved core reload design evaluation methodology described in WCAP-9272-P-A (Reference 3) is used to ensure each Sequoyah core reload design is acceptable. WCAP-9272-P-A was developed to use a systematic process that determines if changes associated with a reload core design impact the response characteristics of the reactor core to such an extent as to invalidate the reference safety analysis. The WCAP-9272-P-A methodology uses bounding reference safety analyses, which are not dependent upon a minimum number of RCCAs in a core, a particular RCCA configuration, or the existence of a symmetric RCCA pattern. These types of RCCA pattern details are not included in the list of key safety parameters assumed in the bounding reference safety analysis, in which individual RCCAs are not explicitly modeled. This level of detail is explicitly accounted for each core reload design in the nuclear design calculations to confirm that the key safety parameter values assumed in the reference analyses remain bounding.

3.5.1 Impacts on the RSAC and WCAP-9272-P-A Methodology The safety analysis reported in UFSAR Chapter 15 is performed using core kinetic characteristics, control rod worths, and core power distributions that historically bound most core reload designs. The WCAP- 9272-P-A process identifies which of these parameters are impacted by a core reload design and identifies them as key safety parameters. The basis of selection of a parameter as a key safety parameter for a given accident is that the parameter could change as a result of core rearrangement, and if it changed, it could affect the accident consequence. The key safety parameters form the basis for determining whether the reference safety analysis applies for a reload cycle following changes in fuel assemblies and configuration and performance or setpoint changes in the reactor plant systems. The values of the key safety parameters used as inputs for the reference, or bounding, safety analyses were selected to conservatively bound the values expected in subsequent cycles. During the core reload design process, cycle-specific values for the key safety parameters are generated and compared to the bounding values used in the reference safety analyses. For each reload cycle, values of the key safety parameters are determined for the reload core during the nuclear, thermal and hydraulic, and fuel rod design processes. If all reload safety parameters for a core are conservatively bounded, the reference safety analysis is assumed to be valid and no revisions are necessary. Using this bounding

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analysis concept, the impact of differences from the reference core are evaluated in place of a new safety analysis of each reload core. The WCAP-9272-P-A Safety Evaluation Report (SER) states in section 2 (Summary of Topical Report): The key safety parameters form the basis for determining whether the reference safety analysis applies for a reload cycle following changes in fuel assemblies and configuration, and performance or setpoint changes in the reactor plant systems. The basis of selection of a parameter as a key safety parameter for a given accident is that (i) the parameter could change as a result of core rearrangement, and (ii) if it changed, it could affect the accident consequence. For each reload cycle, values of the key safety parameters are determined for the reload core during the nuclear, thermal and hydraulic, and fuel rod design processes. When a reload key safety parameter is not bounded, each accident, which includes the parameter, is separately evaluated to determine the impact of the deviation on the accident. If the magnitude of the effect is not easily quantifiable by the bounding evaluation, then a reanalysis is performed to ensure the required margin of safety is maintained for each affected accident. The analysis for each reload considers the exact configuration of the core loading pattern including RCCAs. The removal of a single control bank RCCA impacts the cycle specific calculated values of the key safety parameters as discussed below, but these impacts are explicitly captured in the calculations performed each cycle to assess cycle-to-cycle loading patterns and minor fuel changes. The WCAP- 9272-P-A methodology for the reference analysis is not dependent upon a minimum number of RCCAs in a core, a particular RCCA configuration, or even the existence of a symmetric RCCA pattern. These types of RCCA pattern details are not included in the list of key safety parameters assumed in the bounding reference Safety Analysis, in which individual RCCAs are not explicitly modeled. This level of detail is explicitly accounted for in the confirmation of the applicability of the key safety parameter values for each core reload.

3.5.2 Impacts on WCAP-10216-P-A and WCAP-17661-P-A The WCAP-10216-P-A, Revision 1A (Reference 8) methodology for relaxed axial offset control (RAOC) does not have a dependence on the control pattern or minimum number of total control rods. The axial and radial components synthesized in this analysis are calculated with codes that will explicitly account for the removal of the RCCA at location H-08, as described below. Therefore, the application of the methodology described in WCAP-10216-P-A, Revision 1A is not impacted by the removal of RCCA H- 08.

WCAP-17661-P-A, Revision 1 (Reference 9) provides an improved method for FQ Surveillance. Since the calculations supporting this licensed methodology are those licensed under WCAP-10216-P-A, Revision 1A, there is no impact on using the methods in WCAP-17661-P-A, Revision 1 due to removal of the RCCA at location H-08.

3.5.3 Neutronic Code Capability The Nuclear Design analytical methods and codes used in the application of the WCAP-9272-P-A methodology (WCAP-16045-P-A [Reference 4], WCAP-16045-P-A, Addendum 1-A [Reference 5] and WCAP-10965-P-A [Reference 6]) were rigorously benchmarked and qualified for a variety of reactor types (Westinghouse 2,3,4 loop, Combustion Engineering), fuel types (various lattice types and fuel rod diameters), and burnable poison types (IFBA, WABA, Pyrex, Gadolinia). The Advanced Nodal Code (ANC) (WCAP-10965-P-A) is a nodal neutronics code for multidimensional reactor core calculations, including the prediction of such design parameters as reactivity, assembly average power, rod power and flux, Doppler coefficients, moderator coefficients, boron worth, control rod worth, burnable absorber worth, depletion, and other safety-related parameters.

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The lattice code used to provide multi-group data to ANC has been updated to PARAGON/NEXUS (WCAP-16045-P-A, Addendum 1-A). The qualification of ANC included a broad spectrum of reactor, fuel, and burnable absorber designs. WCAP-16045-P-A, Addendum 1-A and WCAP-10965-P-A demonstrate that ANC is an accurate analytical tool for multidimensional nuclear calculations performed in the design, safety analyses, and operational follow of pressurized water reactor cores. The intended usage of ANC encompasses all applications described in the reload safety evaluation methodology topical report. A change in the number of RCCAs is sufficiently represented by the broad spectrum of reactor, fuel, and burnable absorber designs as well as the off normal condition analyses evaluated in WCAP-16045-P-A, Addendum 1-A and WCAP-10965-P-A and does not impact the capabilities of the codes/methodology or the calculational uncertainties used in the methodology. APOLLO is a one-dimensional code utilized to analyze axial power shapes (WCAP-13524-P-A [Reference 7]). Since it is one dimensional only the total bank worth is utilized in the model. The rod worth values are updated each cycle consistent with rod worth values calculated from the three- dimensional ANC model. The change to the control bank configuration has no impact on APOLLO.

3.5.4 Key Safety Parameter Impact

3.5.4.1 Core Reactivity Key Safety Parameters The values of the core reactivity key safety parameters evaluated for a reload core depend on the burnup of the previous cycle, the number and enrichment of fresh fuel assemblies, the loading pattern of burned and fresh fuel, and the number and location of any burnable poisons. As outlined in WCAP-9272-P-A, these parameters are evaluated for each cycle-specific core loading pattern. The impacts of the removal of RCCA H-08 on these core reactivity key safety parameters are summarized in Table 1.

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Table 1: Core Reactivity Key Safety Parameters Key Safety WCAP-9272 Impact of Removal Parameter Section MTC/MDC 3.3.1.1 Slight impact to the most positive MDC because this parameter is conservatively calculated assuming all RCCAs are inserted into the core. A cycle-specific evaluation of the MTC/MDC values with the removal of Control Rod H-08 will be performed for each core reload design to confirm the most positive MDC remains bounding. Fuel Temperature 3.3.1.2 Potential increase to the fission rate primarily in a single (Doppler) assembly depending on the control bank D position. This Coefficient increase is typically in a low power area during HFP operation primarily affecting a single assembly which has negligible impacts impact on global average fuel temperatures. Boron Worth 3.3.1.3 Minor impact as the primary factor in determining boron worth is the total boron concentration. Effective Delayed 3.3.1.4 Potential increase to the fission rate in the top portion of a Neutron Fraction single assembly depending on the control bank D position. This increase is primarily in a low power area (top end of the fuel assembly) which has negligible impacts on power sharing and the delayed neutron fraction. Prompt Neutron 3.3.1.5 Potential increase to the fission rate in the top portion of a Lifetime single assembly depending on the control bank D position. This increase is primarily in a low power area (top end of the fuel assembly) which has negligible impacts on power sharing and the core average prompt neutron lifetime.

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3.5.4.2 Control Rod Worth Key Safety Parameters The control bank D has the ability to be inserted during at-power operation in accordance with the rod insertion limits. It has the potential to impact the overall core power distribution and its removal has the potential to have an impact on the power axial and radial distribution. Reload core designs typically result in changes in individual RCCA worths and control and shutdown bank worths from cycle to cycle. These changes can be attributed to differences in the neutron flux distribution (thus, reactivity importance) resulting from the unique loading; pattern of burned and fresh fuel assemblies for each core and the fuel depletion occurring during the reload fuel cycle. Changes in control rod worths may also affect rod insertion allowance, trip reactivity, differential rod worths, shutdown margin, and shutdown control rod worth. Table 3.3 of WCAP-9272-P-A lists the limiting directions for each of the control rod worth parameters that are evaluated for each reload core to confirm the UFSAR Chapter 15 analyses remain bounding. The impacts of the removal of RCCA H-08 on the control rod worth key safety parameters are summarized in Table 2 below.

Table 2: Control Rod Worth Key Safety Parameters Key Safety WCAP-9272 Impact of Removal Parameter Section Insertion Limits 3.3.2.1 Potential impact since the RCCA H-8 can be inserted during at power operation. The insertion limits are confirmed to be acceptable each cycle through analysis of accident scenarios starting from both ARO and rods at the insertion limits. This will be evaluated on a cycle specific basis. Total Rod Worth 3.3.2.2 Total rod worth will be reduced with the removal of RCCA H- 8. This key safety parameter is evaluated on a cycle specific basis to ensure shutdown margin and trip reactivity limits are met. Trip Reactivity 3.3.2.3 Reduction of trip reactivity as a function of rod insertion position, which reduces the trip reactivity as a function of time after the RCCAs begin to fall -- a cycle specific evaluation is performed to confirm the trip reactivity remains bounded by the key safety parameter value. Differential Rod 3.3.2.4 Reduction in differential rod worth of the control bank D. Worth Differential rod worth differences are implicitly confirmed via analysis of accident scenarios starting from both ARO and rods at the insertion limits on a cycle specific basis.

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3.5.4.3 Nuclear Design Key Safety Parameters for Specific Events WCAP-9272-P-A, Table 3.4, lists each event and the key safety parameters that are evaluated for each event. Table 3 below summarizes the effects of the removal of RCCA H-8 on the nuclear design key safety parameters or the listed events.

Table 3: Nuclear Design Miscellaneous Key Safety Parameters Event Key Safety WCAP- Impact of Removal Parameter 9272 Section Loss of Coolant Heat Flux Hot 3.3.3.1 Potential impact to the core hot channel factor Accident Channel Factor parameter and axial power distribution since (FQ) RCCCA H-8 can be inserted during at-power operation. The FQ determination for the LOCA event is performed on a cycle specific basis. Uncontrolled Maximum 3.3.1.2 Increases the N-1 critical boron concentration. Boron Dilution Critical Boron The removal of RCCA H-8 effectively creates an Event with N-1 N-2 situation. This key safety parameter is Control Rods confirmed on a cycle specific basis. Inserted Single RCCA Maximum 3.3.3.3 Reduced impact since there are fewer rods Events: Nuclear inserted at HFP conditions. The reduction of Enthalpy Rise control rods present minimizes the impact on the -Single RCCA Hot Channel core power distribution and can decrease the Withdrawal at Factor (FN ) FN . These key safety parameters are evaluated power ǻ+ ǻ+ on a cycle specific basis. -Statically misaligned RCCA during power operation -Dropped RCCA during full power operation

Control Rod Maximum 3.3.3.4 Ejected rod worth and FQ are impacted by the Ejection Accident Ejected Rod absence of RCCA H-8. This impacts the power Worth distribution prior to event initiation and the potential rods investigated for rod ejection. This Heat Flux hot accident is evaluated for acceptability on a cycle Channel Factor specific basis. (FQ) at HFP and HZP Steam Line Break Core 3.3.3.5 Potential increase in post-trip reactivity due to the Accident Reactivity removal of RCCA H-8. The power distribution Insertion and at HZP with all rods inserted is also impacted. Core Power These key safety parameters are confirmed for Distribution each reload on a cycle specific basis.

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In addition to the limits discussed in WCAP-9272-P-A, a limit is placed on the effective neutron multiplication factor (keff) following a control rod ejection event. The safety limit for keff at HZP for RCCA Ejection is less than 0.999 to ensure that the reactor can be brought to a subcritical condition following a reactor trip from an RCCA ejection at HZP. The rod ejection safety analysis assumes that, in addition to the ejected rod, an additional rod adjacent to the ejected rod is stuck out of the core (N-2 event). The removal of H-8 effectively removes an additional control rod from this portion of the analysis. This event and subsequent impacts are evaluated on a cycle specific basis.

3.5.4.4. Thermal and Hydraulic Analyses Key Safety Parameters The thermal and hydraulic analyses are performed to assess the impact of the reload core on the design basis acceptance limits. The removal of Control Rod H-08 is discussed below. The hydraulic evaluation of the reload core requires a review of the new fuel assembly design (nozzles, grids, fuel rods, etc.) to be inserted in to the core. This design is compared with the design of the fuel assemblies remaining in the core to ensure the new fuel assemblies are hydraulically compatible with the fuel assemblies remaining in the core. As discussed in Section 3.4.2 of this Attachment, removal of the RCCA from the H-08 core location will have a minimal impact on the hydraulic characteristics of the core and the DNB limits will not be exceeded. Therefore, the removal of H-08 from the fuel assembly in this location will not result in a violation of any safety limits for reload cores. The effects of the removal of Control Rod H-08 on the thermal and hydraulic key safety parameters are summarized in Table 4 below.

Table 4: Thermal-Hydraulic Analysis Key Safety Parameters Key Safety WCAP-9272 Impact of Removal Parameter Section

E Engineering Hot 4.3.1 No impact to heat flux engineering hot channel factor FQ and Channel Factors WKHHQWKDOS\ULVHHQJLQHHULQJKRWFKDQQHOIDFWRU)ǻ+E1 because RCCA H-08 removal does not impact fuel pellet physical characteristics and because RCCA H-08’s removal has a negligible impact on at-power core power distributions. Axial Fuel Stack 4.3.2 No impact because removal of RCCA H-08 does not impact the Shrinkage physical design of the fuel. Fuel Temperatures 4.3.3 No impact on the physical fuel design parameters and negligible impact on the at-power core power distributions assumed in the calculation of fuel temperatures. Rod Internal 4.3.4 No impact because the removal of RCCA H-08 does not affect Pressure the physical design of the fuel and its removal has a negligible impact on the at-power core power distributions assumed in the calculation of rod internal pressure. Core Limit Lines 4.3.5 No impact because the removal of RCCA H-08 has no impact on the parameters presented in Table 4-2 of WCAP-9272-P-A.

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3.5.4.5. DNB Analysis for Specific Events For the reference analyses, a sub-channel thermal hydraulic analysis using the VIPRE thermal-hydraulic computer code is performed using bounding power shapes to ensure the Departure from Nucleate Boiling Ratio (DNBR) stays above the acceptance limit for the following events in Chapter 15 of the UFSAR: • Zero and full power steam line break • Loss of forced RCS flow • Uncontrolled RCCA bank withdrawal from a subcritical or low-power startup condition • Control rod out of position • Dropped RCCA Apart from the steam line break event, the cycle-specific power shapes are compared to the bounding power shapes to ensure they remain bounded. If the cycle-specific event is no longer bounding, an evaluation that may use a sub-channel thermal hydraulic code is performed to ensure the DNBR acceptance limit is satisfied. For the steam line break event, a thermal hydraulic analysis using VIPRE and cycle-specific power shapes is performed for each core reload design to ensure the DNB limits are satisfied.

3.5.5 UFSAR Chapter 15 Safety Analysis Analysis Summary The non-LOCA safety analyses for the fuel transition (RTSR) program have been assessed for the impact of removal of the control rod from core location H-08. These analyses do not explicitly model individual control rods and are not dependent upon control bank configuration. Therefore, they are not directly affected by the removal of the H-08 control rod. The analyses may be indirectly affected by changes to the core and reactor coolant system (RCS) flow and geometrical characteristics data, rod drop characteristics data, and the core neutronics safety parameters. However, it has been determined that only the core neutronics safety parameters are affected by the removal of the H-08 control rod. Note that the removal of the H-08 control rod does not impact the small-break LOCA (SBLOCA) or the large-break LOCA (LBLOCA) analyses. The core neutronics safety parameters used in the non-LOCA safety analyses are selected to conservatively bound the values expected in subsequent reload cycles (i.e., they are intended to be cycle- independent). The cycle specific values are compared to the bounding values and if the bounding values are found to remain conservative, then the non-LOCA analyses remain valid. Therefore, while removal of the H-08 control rod impacts the cycle-specific values for parameters such as shutdown margin, trip reactivity, boron concentration, and moderator temperature coefficient, the values modeled in the non- LOCA analyses remain bounding with the exception of the hot zero power (HZP) stuck rod coefficients. These coefficients are used in the HZP Steamline Break (HZP SLB) analysis to model the reactivity feedback in the core at zero power conditions with the most reactive control rod stuck out of the core. These coefficients are also used in the HZP Feedwater Malfunction (HZP FWM) analysis; however, HZP conditions were not explicitly analyzed for the Sequoyah units in support of the fuel transition. Specifically, a generic study performed by Westinghouse demonstrated that the consequences of a HZP FWM with an increased feedwater flow rate of less than 150% of the nominal full power flow rate are non-limiting. Confirmation of the stuck rod coefficients is performed on a cycle-specific basis as part of the standard reload process. This is accomplished by verifying that the return to power predicted by the core design model, using the HZP SLB statepoint information, is sufficiently close to the peak heat flux

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Westinghouse Non-Proprietary Class 3 Attachment 9 predicted by the safety analysis model. Therefore, the HZP SLB analysis was assessed to address this input change. This assessment, along with each of the events contained within the Sequoyah Updated Final Safety Analysis Report (UFSAR), are discussed in the following sections to support the removal of the H-08 control rod. Uncontrolled Rod Cluster Control Assembly (RCCA) Withdrawal from Subcritical (RWFS) (UFSAR Section 15.2.1) The RWFS event is defined as an uncontrolled addition of reactivity to the reactor core caused by withdrawal of one or more RCCA banks, resulting in a rapid power excursion. The power excursion is limited by the Doppler feedback and the event is promptly terminated by a reactor trip on the Power Range High Neutron Flux Low setpoint. Due to the inherent thermal lag in the fuel pellet, heat transfer to the RCS is relatively slow. The purpose of the analysis is to demonstrate that the departure from nucleate boiling (DNB) design basis is met. All core neutronics safety parameter values applicable to this event, including the event-specific maximum differential rod worth and power distributions, were confirmed to remain valid for the removal of the H-08 control rod and are expected to remain valid for future cycles. Therefore, the analysis performed for the fuel transition supports the permanent removal of the H-08 control rod. Uncontrolled RCCA Withdrawal at Power (RWAP) (UFSAR Section 15.2.2) The RWAP event is defined as an inadvertent addition of reactivity to the core caused by the withdrawal of RCCA banks when the core is at power with the turbine in operation. The event is analyzed at 10%, 60%, and 100% of rated thermal power, assuming beginning of cycle (BOC) and end of cycle (EOC) reactivity conditions, and for a large spectrum of reactivity insertion rates. Unless terminated by manual or automatic action, the power mismatch between the reactor core power generation and the steam generator heat extraction results in a coolant temperature increase that could potentially lead to a violation of the RCS overpressure or DNB ratio (DNBR) limit. Therefore, in order to prevent damage to the fuel clad, the reactor protection system is designed to terminate the transient before the RCS overpressure or DNBR limit is violated. The purpose of the analysis is to demonstrate that the peak RCS pressure remains below the overpressure limit and the minimum DNBR remains above the safety analysis limit (SAL) value. All core neutronics safety parameter values applicable to this event were confirmed to remain valid for the removal of the H-08 control rod and are expected to remain valid for future cycles. Therefore, the analysis performed for the fuel transition supports the permanent removal of the H-08 control rod. RCCA Misalignment (UFSAR Section 15.2.3) The RCCA misalignment analysis includes the following events: x One or more dropped RCCAs within the same group x A dropped RCCA bank x Statically misaligned RCCA For the Statically Misaligned RCCA event, Westinghouse generates nuclear models at accident-specific conditions to demonstrate that the event-specific acceptance criteria (primarily the DNB design basis) are met. This event is bounded by the other misalignment events for the removal of the H-08 control rod. Under the Westinghouse safety analysis methodology, the one or more dropped RCCAs within the same group / dropped RCCA bank (i.e., Dropped Rod) event is analyzed using a generically bounding process.

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Bounding transient statepoints that cover a matrix of reactivity combinations were compiled for various plant designs as part of a Westinghouse Owners Group (WOG) program. These statepoints are evaluated on a plant-by-plant basis to confirm their continued applicability with respect to both the plant design and operating conditions. The primary inputs that must be confirmed are related to the rod control system parameters, which are not affected by the removal of the H-08 control rod. The remaining inputs used in the WOG program were specifically chosen to be conservatively bounding for all plants within the given plant type (i.e., 2-loop, 3 loop, or 4-loop). This ensured that the statepoints generated would produce limiting DNBR calculations. All core neutronics safety parameter values applicable to this event, including the maximum dropped rod worth, were confirmed to remain valid for the removal of the H-08 control rod and are expected to remain valid for future cycles. Therefore, the analysis performed for the fuel transition supports the permanent removal of the H-08 control rod. Uncontrolled Boron Dilution (UFSAR Section 15.2.4) The Boron Dilution event is analyzed to demonstrate that the operator has sufficient time to terminate the RCS dilution before a complete loss of shutdown margin occurs. The calculation of the operator action time for the Boron Dilution event is a function of RCS volumes, thermodynamic properties, initial and critical boron concentrations, and the dilution flow rate. Per UFSAR Section 15.2.4.2, Boron Dilution events during power operation (Mode 1), startup (Mode 2), and refueling (Mode 6) are explicitly addressed for Sequoyah. The high flux at shutdown alarm, which is controlled in accordance with Technical Specification 3.3.9, is available to alert operators to dilutions in the shutdown modes (Modes 3- 5). No calculation is performed for Mode 6, since the event is administratively precluded by Technical Specification 3.9.2. Therefore, only Modes 1 and 2 are explicitly analyzed for the Sequoyah units. All core neutronics safety parameter values applicable to this event, including the minimum initial to critical boron concentration ratios in Modes 1 and 2, were confirmed to remain valid for the removal of the H-08 control rod and are expected to remain valid for future cycles. Additionally, since the RWAP analysis (UFSAR Section 15.2.2) is unaffected, the operator alarm time used in Mode 1 with manual rod control remains valid. Therefore, the analysis performed for the fuel transition supports the permanent removal of the H-08 control rod. Partial Loss of Flow (PLOF) (UFSAR Section 15.2.5), Complete Loss of Flow (CLOF) (UFSAR Section 15.3.4), and Locked Rotor (LR) (UFSAR Section 15.4.4) The PLOF and CLOF events may result from a mechanical or electrical failure in one or more reactor coolant pumps (RCPs). These faults may occur from an undervoltage condition in the electrical supply to the RCPs or from a reduction in motor supply frequency to the RCPs due to a frequency disturbance on the power grid. The Locked Rotor event (which is conservatively analyzed by permitting reverse spinning but no forward flow) is caused by a mechanical failure in a single RCP. The PLOF and CLOF analyses are performed to demonstrate that the minimum DNBR remains above the SAL value. The Locked Rotor analysis determines the percentage of fuel rods expected to experience a DNBR below the

SAL value (i.e., Rods-in-DNB case) and investigates the peak clad temperature (PCT), hot spot Zr-H2O reaction, and maximum RCS pressure transient with respect to the applicable limits (i.e., RCS Overpressure / PCT case). All core neutronics safety parameter values applicable to these events, including the peaking factors, were confirmed to remain valid for the removal of the H-08 control rod and are expected to remain valid for

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future cycles. Therefore, the analysis performed for the fuel transition supports the permanent removal of the H-08 control rod. Startup of an Inactive Reactor Coolant Loop (SUIL) (UFSAR Section 15.2.6) Technical Specification 3.4.4 requires that all four RCPs be operating in Modes 1 and 2; therefore, power operation with an inactive loop is precluded. This event was originally included in the UFSAR when operation with a loop out of service (i.e., N-1 operation) was considered. It remains within the UFSAR for historical purposes but is not actively maintained. Loss of Load / Turbine Trip (LOL/TT) (UFSAR Section 15.2.7) This event is defined as a complete loss of steam load from full-power without a direct reactor trip (or a turbine trip without a direct reactor trip) and is analyzed to demonstrate that 1) RCS and main steam system (MSS) pressures remain below 110% of design and 2) the minimum DNBR remains above the SAL value. All core neutronics safety parameter values applicable to this event were confirmed to remain valid for the removal of the H-08 control rod and are expected to remain valid for future cycles. Therefore, the analysis performed for the fuel transition supports the permanent removal of the H-08 control rod. Loss of Normal Feedwater / Loss of Offsite Power (LONF/LOOP) (UFSAR Sections 15.2.8 and 15.2.9) A loss of normal feedwater (from pump failures, valve malfunctions, or loss of offsite AC power) reduces the capability of the secondary system to remove the heat generated in the reactor core. If an alternative supply of feedwater were not supplied to the plant, decay heat following reactor trip would heat the RCS water causing it to expand. The thermal expansion of the RCS fluid could lead to a water solid pressurizer condition with subsequent damage to the pressurizer safety valves (PSVs) as a result of water relief through these valves. Damage to these valves could compromise the RCS pressure boundary, thus leaving the RCS unisolatable, which is a violation of the acceptance criteria for these events (i.e., accident does not lead to worse plant condition). Thus, these events are conservatively analyzed to ensure that the auxiliary feedwater (AFW) system is adequately sized to reestablish the secondary heat sink prior to filling the pressurizer. In addition to the licensing basis full-power cases, part-power cases are also analyzed to assess the impact of the low-low steam generator trip time delay (TTD) system. All core neutronics safety parameter values applicable to this event were confirmed to remain valid for the removal of the H-08 control rod and are expected to remain valid for future cycles. Therefore, the analysis performed for the fuel transition supports the permanent removal of the H-08 control rod. Feedwater Malfunction (FWM) (UFSAR Section 15.2.10) The FWM event is defined as a reduction in feedwater temperature or an increase in feedwater flow to the steam generators resulting in excessive heat removal from the RCS. While both hot full power (HFP) and HZP conditions are considered, only the HFP condition is explicitly analyzed. The HZP condition is not analyzed since it is non-limiting. The event is analyzed to demonstrate that the DNB design basis is met. All core neutronics safety parameter values applicable to this event were confirmed to remain valid for the removal of the H-08 control rod and are expected to remain valid for future cycles. Therefore, the analysis performed for the fuel transition supports the permanent removal of the H-08 control rod.

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Excessive Load Increase (ELI) (UFSAR Section 15.2.11)

The ELI transient is defined as a rapid increase in steam flow that causes a power mismatch between reactor core power and turbine load demand. Depending on the response characteristics of the reactor protection system, this event may not result in an immediate reactor trip and could possibly lead to DNB. All core neutronics safety parameter values applicable to this event were confirmed to remain valid for the removal of the H-08 control rod and are expected to remain valid for future cycles. Therefore, the analysis performed for the fuel transition supports the permanent removal of the H-08 control rod. Accidental Depressurization of the RCS (UFSAR Section 15.2.12) An accidental depressurization of the RCS (i.e., RCS Depressurization) could occur as a result of an inadvertent opening of a pressurizer power-operated relief valve (PORV) or spray valve. However, the event is conservatively analyzed by modeling a stuck open PSV since it has a much larger capacity than a PORV or spray valve and thus, simulates the most adverse depressurization that could potentially occur(1). The purpose of the analysis is to demonstrate that the minimum DNBR remains above the SAL value. All core neutronics safety parameter values applicable to this event were confirmed to remain valid for the removal of the H-08 control rod and are expected to remain valid for future cycles. Therefore, the analysis performed for the fuel transition supports the permanent removal of the H-08 control rod. Accidental Depressurization of the Main Steam System (MSS) (UFSAR Section 15.2.13) The MSS Depressurization (also known as the credible steamline break event) is defined as the failure of an atmospheric relief valve, steam dump valve, or steam generator safety valve. This event is analyzed as part of the HZP SLB analysis, which is discussed in UFSAR Section 15.4.2.1. Due to the similar nature of these events, the discussion for the HZP SLB (also known as the hypothetical steamline break event) is also applicable to the MSS Depressurization. Based on that discussion, the analysis performed for the fuel transition supports the permanent removal of the H-08 control rod. Inadvertent Operation of the Emergency Core Cooling System at Power (IOECCS) (UFSAR Section 15.2.14) The IOECCS event results in an increase in the RCS inventory that, without mitigation, could lead to a water-solid pressurizer condition with the potential for subsequent damage to the PSVs as a result of water relief through these valves. The main acceptance criterion is to demonstrate that the event does not generate a more serious plant condition (i.e., propagate from a Condition II event into a more severe Condition III or IV event). This criterion (known as the non-escalation criterion) is met by demonstrating that the PSVs remain operable. However, the criterion is conservatively met by demonstrating that the pressurizer does not become water-solid with subsequent water relief through either the pressurizer PORVs or PSVs. This alleviates any concerns related to the possible progression into a Small Break LOCA (Condition III event) due to the potential failure of the PSVs or PORVs to reseat following water relief. As discussed in UFSAR Section 15.2.14.2, the non-escalation criterion is addressed for the Sequoyah units by calculating a realistic pressurizer fill time for the IOECCS event to ensure that the operators have sufficient time to mitigate the event by recovering pressurizer level control. Historically,

1 A stuck open PSV is beyond the scope of a Condition II event and is considered to be a Small Break LOCA (SBLOCA), which is a Condition III event. Since the RCS Depressurization is a Condition II event, a stuck open PSV does not need to be considered. However, it is conservatively modeled to ensure a more limiting DNB analysis; it is not a design basis load condition for pipe stress analysis.

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the IOECCS analysis also confirms that the DNBR remains above the SAL value. However, the DNBR increases throughout the event such that the SAL value is never challenged. All core neutronics safety parameter values applicable to this event were confirmed to remain valid for the removal of the H-08 control rod and are expected to remain valid for future cycles. Therefore, the analysis performed for the fuel transition supports the permanent removal of the H-08 control rod. Minor Secondary System Pipe Breaks (UFSAR Section 15.3.2) The minor secondary system pipe break event is defined in the UFSAR as a break that results in a steam release rate equivalent to a 6-inch diameter break or smaller. The minor breaks must result in the failure of only a small fraction of the fuel elements in the reactor. Since the hypothetical steamline break analyzed in support of UFSAR Section 15.4.2.1 conservatively applies the acceptance criteria that the DNBR and peak linear heat generation rate (kW/ft) SAL values are met, and the largest break size is limiting for the UFSAR Section 15.4.2.1 analysis, this event continues to be bounded by the analysis documented in UFSAR Section 15.4.2.1. Due to the similar nature of these events, the discussion for the hypothetical break is also applicable to minor secondary system pipe breaks. Based on that discussion, the analysis performed for the fuel transition supports the permanent removal of the H-08 control rod. Steamline Break with Coincident Rod Withdrawal at Power (SLB w/ RWAP) (UFSAR Section 15.3.7) The SLB w/ RWAP analysis addresses a HFP SLB occurring outside containment near the turbine impulse transmitters or inside containment near the excore detectors, both of which provide input to the rod control system. If the associated cabling and connections are not environmentally qualified for the steam impinging on the equipment, a potential malfunction of the rod control system that results in a coincidental rod withdrawal must be considered. The rods will withdraw until they reach their full-out position, or a reactor trip signal is generated, thus releasing the rods into the core. The event is conservatively analyzed to demonstrate that the DNBR and peak linear heat generation rate (kW/ft) SAL values are met. All core neutronics safety parameter values applicable to this event, including the event-specific maximum integral rod worth and Doppler defect, were confirmed to remain valid for the removal of the H-08 control rod and are expected to remain valid for future cycles. Therefore, the analysis performed for the fuel transition supports the permanent removal of the H-08 control rod. Hot Zero Power Steamline Break (HZP SLB) (UFSAR Section 15.4.2.1) This event results in excessive steam relief that causes the RCS to cool down, thus invoking a positive reactivity excursion. Since the credible and minor break events (UFSAR Sections 15.2.13 and 15.3.2, respectively) create a depressurization of the secondary side with an effective opening size that is within the spectrum of break sizes analyzed for this event, those events are addressed along with the hypothetical SLB event. The event is conservatively analyzed to demonstrate that the DNBR and peak linear heat generation rate (kW/ft) SAL values are met. All core neutronics safety parameter values applicable to this event were confirmed to remain valid with the exception of the HZP stuck rod coefficients. Therefore, the limiting HZP SLB case documented in the fuel transition analysis, which models a maximum break size of 1.40 ft2 and offsite power available, was rerun with the revised stuck rod coefficients. It was confirmed that an acceptable power match was achieved and that the DNBR and fuel centerline melting SAL values continued to be met.

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Feedline Break (FLB) (UFSAR Section 15.4.2.2) The FLB event is defined as a break in a feedwater pipe large enough to prevent the addition of sufficient feedwater to the steam generators to maintain shell-side fluid inventory in the steam generators. This event is analyzed to demonstrate that margin to the hot leg saturation temperature exists and, as a result, the core remains intact and in a coolable geometry. This event is conservatively analyzed to ensure that the AFW system is adequately sized to reestablish the secondary-side heat sink via the non-faulted steam generators prior to reaching a saturated condition in the RCS hot legs. In addition to the licensing basis full-power cases, part-power cases are also analyzed to assess the impact of the low-low steam generator TTD system. All core neutronics safety parameter values applicable to this event were confirmed to remain valid for the removal of the H-08 control rod and are expected to remain valid for future cycles. Therefore, the analysis performed for the fuel transition supports the permanent removal of the H-08 control rod. RCCA Ejection (UFSAR Section 15.4.6) This event is defined as the mechanical failure of a control rod mechanism pressure housing, resulting in the ejection of the RCCA and drive shaft to the fully withdrawn position. This results in an extremely rapid increase in core reactivity and power. The power excursion is limited by the Doppler feedback and the event is quickly terminated by a reactor trip on Power Range High Neutron Flux. The transient responses for the hypothetical RCCA Ejection event are analyzed at BOC and EOC, for both full and zero power operating conditions, in order to bound the entire fuel cycle and expected operating conditions. The analyses are performed to show that the fuel and clad limits are not exceeded. All core neutronics safety parameter values applicable to this event, including the event-specific Doppler defect, delayed neutron fraction, trip reactivity, peaking factors, maximum ejected rod worth, maximum burnup, and isothermal temperature coefficient, were confirmed to remain valid for the removal of the H-08 control rod and are expected to remain valid for future cycles. Therefore, the analysis performed for the fuel transition supports the permanent removal of the H-08 control rod. Anticipated Transients without Scram (ATWS) (Not a UFSAR Chapter 15 event) As defined in 10 CFR 50.62, the ATWS event is an anticipated operational occurrence (such as loss of feedwater, loss of load, or loss of offsite power) that is accompanied by a failure of the reactor protection system to shut down the reactor. The event results in a severe increase in RCS pressure, actuating both the pressurizer PORVs and PSVs before approaching the American Society of Mechanical Engineers (ASME) Service Level C stress limit (i.e., 3215 psia). The RCS pressure rise is primarily limited by the negative reactivity feedback associated with a negative moderator temperature coefficient (MTC). All core neutronics safety parameter values applicable to this event, including the 95/95 most positive HFP MTC of -8.0 pcm/°F, were confirmed to remain valid for the removal of the H-08 control rod and are expected to remain valid for future cycles. Therefore, the analysis performed for the fuel transition supports the permanent removal of the H-08 control rod. Conclusions The Sequoyah non-LOCA safety analyses have been confirmed to support operation with the permanent removal of the H-08 control rod. Steam Generator Tube Rupture (SGTR) (UFSAR Section 15.4.3) was one of the non-LOCA events that does not depend on the fuel type and local conditions within the core and therefore was not reanalyzed for the fuel transition and thus remains unaffected by the removal of the H-08 control rod.

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3.6 Nuclear Design Multi-Cycle Margin Assessment Nuclear design performed a multi-cycle margin assessment to determine the effect removal of RCCA H- 08 would have on the equilibrium and transition core designs generated for the Sequoyah Reload Transition Safety Report (RTSR). These core designs include the two potential transition cycle designs (from Framatome HTP to Westinghouse RFA-2 designs) and two potential equilibrium cycles (full Westinghouse RFA-2). The 77 and 76 feed equilibrium cycles are labeled in this document as equilibrium cycle 1 and 2, respectively. Although these core designs have not been utilized they are representative of the upcoming transition from Framatome HTP fuel to Westinghouse RFA fuel and the subsequent operation with only Westinghouse RFA fuel. Nuclear design safety confirmations performed for each reload core design with potential to be impacted by the removal of RCCA H-08 were analyzed. Results of this comparison are shown for the cycles analysis both with and without RCCA H-08. The results of this assessment indicate that removal of RCCA H-08 generally reduces the margin for some key safety parameters including shutdown margin while other accident impacts are negligible. This assessment supports the conclusion that reactor cores can be safely designed with RCCA H-08 removed. The core designs generated for the fuel transition are of typical cycle lengths and design and are indicative of potential future core designs. However, these core designs were not designed with RCCA H-08 removal in mind. Future core designs created with RCCA H-08 removal in mind could potentially gain back some of the margin lost due to its removal. Note that margins shown are representative and the calculations are performed only to determine potential impact to the key safety parameters. Exact methods, margins, and confirmations will be determined during each cycles reload design confirmation. Appropriate uncertainties are already included in all safety parameter confirmations and further uncertainties are unnecessary. Shutdown Margin A summary of the shutdown margin is provided in Table 5 below for the four representative loading patterns previously discussed. 7KHNH\VDIHW\SDUDPHWHUOLPLWIRUVKXWGRZQPDUJLQUHDFWLYLW\LVǻȡ The removal of RCCA H-08 has a negative impact on the overall shutdown margin, however, the impacted sample cores retain the minimum shutdown margin currently utilized in the safety analysis. Based on this assessment, there will be sufficient margin to meet the shutdown margin limit with RCCA H-08 removed and current core design strategies. 7KHVKXWGRZQPDUJLQ 6'0 YDOXHRIǻȡERXQGVWKH6'0YDOXHIRUW\SLFDOUHORDGFRUHVDQGLW allows the acceptance criteria to be met. All subsequent reload cores since plant licensing have met the ǻȡOLPLWLQFOXGing the Sequoyah Unit 1 and Unit 2 cores with Control Rod H-08 removed. During the core reload design process, any key safety parameter violations are transmitted to the cognizant safety analysis group for evaluation. Collaboration between the impacted functional groups may identify additional margin that may be available to support evaluation or reanalysis of impacted analyses. If no margin is identified, a reanalysis is performed and the analysis of record (AOR) is updated. Following removal of Control Rod H-08, the Sequoyah Unit 1 and Unit 2 core design was evaluated and several key safety parameters were impacted. However, the impacted parameters remained bounded by the key safety parameter limits and no evaluations or revisions to the analyses of record (AOR) were required.

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Table 5: Shutdown Margin Summary Minimum Minimum Shutdown Margin Shutdown Margin With H-08 Without H-08 Model Burnup (%) (%) BOC 69.5 36.4 Transition 1 EOC 42.5 16.3 BOC 67.4 19.1 Transition 2 EOC 27.5 3.5 BOC 42.5 7.3 Equilibrium 1 EOC 49.9 12.3 BOC 71.1 23.3 Equilibrium 2 EOC 35.1 5.1

Rod Ejection A summary of rod ejection calculated at hot full power (HFP) is shown in Table 6. A summary of rod ejection at hot zero power (HZP) is shown in Table 7. The key safety parameters for rod ejection are ejected rod worth and FQ. All margins are shown based on the analyzed key safety parameters. As seen in the results there is a slight gain of margin in several cases with H-08 removed. Since there is no adjacent rod available to be ejected, the power is more balanced between the ejected rod location and the previously occupied RCCA H-08 location. This causes a slight reduction in both ejected rod worth and power peaking factor leading to either negligible differences or slight margin gain. Based on this assessment, there will be sufficient margin to meet the rod ejection limit with RCCA H-08 removed and current core design strategies.

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Table 6: HFP Rod Ejection Summary

RCCA Rod Worth FQ H-08 Margin Margin Model treatment Burnup (%) (%) Without BOC 79.2 60.7 H-08 EOC 70.7 53.7 Transition 1 With BOC 80.4 60.4 H-08 EOC 71.7 53.8 Without BOC 79.3 61.2 H-08 EOC 68.1 52.2 Transition 2 With BOC 73.9 61.4 H-08 EOC 68.1 52.1 Without BOC 81.9 62.5 H-08 EOC 68.9 53.4 Equilibrium 1 With BOC 79.8 62.1 H-08 EOC 69.5 53.3 Without BOC 81.7 62.4 H-08 EOC 68.7 52.9 Equilibrium 2 With BOC 76.6 62.0 H-08 EOC 68.9 52.7

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Table 7: HZP Rod Ejection Summary

RCCA Rod Worth FQ H-08 Burnup Margin Margin Model treatment (MWD/MTU) (%) (%) Without BOC 52.8 44.4 H-08 EOC 29.0 9.5 Transition 1 With BOC 40.1 34.3 H-08 EOC 23.3 3.3 Without BOC 56.5 38.1 H-08 EOC 16.5 6.9 Transition 2 With BOC 36.0 20.0 H-08 EOC 11.4 2.3 Without BOC 59.0 49.9 H-08 EOC 21.8 14.0 Equilibrium 1 With BOC 43.9 38.3 H-08 EOC 15.2 8.2 Without BOC 58.9 49.7 H-08 EOC 18.7 11.1 Equilibrium 2 With BOC 42.0 36.6 H-08 EOC 13.3 6.4

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N-2 Subcriticality following Rod Ejection

The key parameters of interest for N-2 subcriticality is that keff at HZP for RCCA ejection is less than 0.999. This ensures the reactor can be brought to a subcritical condition following a reactor trip from an RCCA ejection at either HFP or HZP. The N-2 rod worth is the sum of the ejected rod worth plus the highest adjacent rod worth. The key safety parameter limit for N-2 subcriticality is keff ”DQGLVPHW by confirming the N-2 rod worth is less than the actual shutdown margin (SDM) plus the worst stuck rod worth minus uncertainties. Table 8 provides a summary of N-2 subcriticality calculations for the representative cycles. Based on this assessment, there will be sufficient margin to meet the N-2 subcriticality following rod ejection limit with RCCA H-08 removed and current core design strategies.

Table 8: N-2 Subcriticality following Rod Ejection Summary RCCA N-2 H-08 Burnup Margin Model treatment (MWD/MTU) (%) Without BOC 64.4 H-08 EOC Transition 1 16.8 With BOC 60.8 H-08 EOC 12.1 Without BOC 62.3 H-08 EOC Transition 2 19.7 With BOC 54.7 H-08 EOC 14.5 Without BOC 70.8 H-08 EOC Equilibrium 1 20.2 With BOC 65.8 H-08 EOC 15.6 Without BOC 72.0 H-08 EOC Equilibrium 2 23.4 With BOC 55.6 H-08 EOC 17.1

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Moderator Density Coefficient A summary of moderator density coefficient (MDC) is provided in Table 9. The MDC is conservatively confirmed with all rods inserted during HFP conditions. The differences in total rod worth have limited impact on the global parameter of MDC. Based on this assessment, there will be sufficient margin to meet the MDC limit with RCCA H-08 removed and current core design strategies.

Table 9: MDC Summary MDC Margin MDC Margin With H-08 Without H-08 Model (%) (%) Equilibrium 1 17.57 19.90 Equilibrium 2 16.91 17.60 Transition 1 19.32 20.70 Transition 2 16.04 17.01

Fǻ+ vs Power

A summary of Fǻ+ vs Power is provided in Table 10 for beginning of life (BOL) and Table 11 for mid cycle. This limit is confirmed by utilizing the most adverse core operating conditions within the operating space allowed by the anticipated specific limits in the core operating limits report (COLR). In this case, that includes rods inserted to the deepest rod insertion limit position with the axial offset skewed to the most positive value. The limit being confirmed is the Fǻ+ limit intended to be included in the COLR. The intended limit is of a typical Westinghouse structure with the HFP Fǻ+ multiplied by a factor of (1+0.3 * (1- Power)). This increases the Fǻ+limit as power decreases to account for the increased peaking at lower powers. The BOL results in Table 10 show the intended limit being exceeded for some of the low power confirmations when RCCA H-08 is removed. This is only seen during the BOL cases with negligible margin impacts later in cycle as evidenced by Table 11.

The Fǻ+ values seen in the core are loading pattern dependent and can change significantly between differing cycle designs. A loading pattern designed with the knowledge that RCCA H-08 will not be present can meet the intended limit. This is shown with the transition 1 cycle design having sufficient margin at all power levels. Future actual core designs will need to account for the loss of margin at low power for this check and design the core accordingly.

Options in addition to loading pattern design consideration would be to increase the Fǻ+ COLR limit for low power operation or restrict rod insertion via the COLR rod insertion limits. Increasing the Fǻ+ limit for low power conditions would take advantage of the extra margins known to be present for this core condition. All accidents that utilize low power Fǻ+ values will be ensured to use conservative inputs in comparison to the COLR limit as part of each cycles reload design safety confirmation. The second option of restricting the rod insertion limits would decrease the radial power distribution impact seen at lower powers. The decreased rod insertion could be limited to a portion of cycle since the intended limit is only exceeded for a small portion of the cycle. As both limits are present in the COLR, they will be determined on a cycle specific basis as part of the standard design process.

The Fǻ+ vs Power limit violations occurred due to taking core designs which were meant to be bounding representations of Transition and Equilibrium cycles with H-08 present, not actual/typical core designs

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Table 10: BOL Fǻ+ vs. Power Summary

Minimum Fǻ+ Minimum Fǻ+ Margin Margin Power With H-08 Without H-08 Model (%) (%) (%) 1.00 9.53 6.68 0.75 14.25 4.79 Equilibrium 1 0.50 17.96 2.61 0.25 20.65 -1.96 0.00 20.54 -5.95 1.00 10.74 6.17 0.75 16.08 3.73 Equilibrium 2 0.50 20.73 1.67 0.25 20.24 -3.25 0.00 20.05 -7.56 1.00 9.22 6.99 0.75 12.30 5.56 Transition 1 0.50 15.98 2.50 0.25 21.69 4.42 0.00 21.91 6.47 1.00 8.71 6.17 0.75 12.18 3.49 Transition 2 0.50 15.20 1.12 0.25 20.70 -2.94 0.00 22.30 -5.95

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Table 11: Mid Cycle Fǻ+ vs. Power Summary

Minimum Fǻ+ Minimum Fǻ+ Margin Margin Power With H-08 Without H-08 Model (%) (%) (%) 1.00 8.26 8.77 0.75 10.82 12.60 Equilibrium 1 0.50 12.11 15.26 0.25 11.16 15.31 0.00 10.33 15.16 1.00 7.95 8.39 0.75 10.70 12.30 Equilibrium 2 0.50 12.27 15.09 0.25 11.32 15.00 0.00 10.37 14.53 1.00 8.20 8.58 0.75 10.41 12.48 Transition 1 0.50 11.06 14.48 0.25 11.01 15.36 0.00 8.86 13.89 1.00 6.80 6.04 0.75 9.82 7.16 Transition 2 0.50 15.59 7.91 0.25 17.02 15.52 0.00 16.09 20.73

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Dropped Rod A summary of the dropped rod results is provided in Table 12. The key safety parameter for the dropped rod event is departure from nucleate boiling (DNB) monitored via the Fǻ+. The dropped rod event bounds the dropped bank event for Sequoyah. The accident is analyzed by determining the lowest pre-accident Fǻ+ that would lead to a post-accident increase large enough to cause DNB. The impacts to the dropped rod event are seen to be negligible following the removal of RCCA H-08. Based on this assessment, there will be sufficient margin to meet the dropped rod limit with RCCA H-08 removed and current core design strategies.

Table 12: Dropped Rod Summary

Minimum Fǻ+ Minimum Fǻ+ Margin Margin With H-08 Without H-08 Model (%) (%) Equilibrium 1 9.85 10.36 Equilibrium 2 9.91 10.36 Transition 1 9.85 10.67 Transition 2 9.97 10.42

Boron Dilution A summary of the boron dilution results can be seen in Table 13. The key safety parameter confirmed by nuclear design for the boron dilution event is the ratio of initial boron concentration at the most reactive burnup to the maximum critical boron concentration for the applicable modes of operation. This ratio ensures appropriate operator action time for the event. While there is a reduction in margin based on the removal of H-08, the overall impact is seen to be within the accident analysis performed as part of the fuel transition. Based on this assessment, there will be sufficient margin to meet the boron dilution analysis with RCCA H-08 removed and current core design strategies.

Table 13: Boron Dilution Summary Margin Margin With H-08 Without H-08 Model Temperature (%) (%) HFP 63.84 43.09 Equilibrium 1 HZP 12.16 9.07 68 1.91 1.31 HFP 62.16 43.60 Equilibrium 2 HZP 12.05 9.20 68 1.87 1.33 HFP 64.60 45.78 Transition 1 HZP 11.04 8.46 68 1.87 1.86 HFP 55.88 40.29 Transition 2 HZP 11.65 9.08 68 1.73 1.31

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Transient FQ Confirmation

The relaxed axial offset control analysis confirms transient FQ values during normal operation. Since operation without a rod in the control bank has the potential to impact power maneuvers the impact on the peaking factors were investigated. A summary of the transient FQ results can be seen in Table 14. The results show the limiting transient FQ values are negligibly impacted by the removal of RCCA H-08.

Based on the assessment, there will be sufficient margin to meet the transient FQ and kW/ft limits with RCCA H-08 removed and current core design strategies.

Table 14: Transient FQ Summary Limiting Transient Limiting Transient FQ Margin FQ Margin With H-08 Without H-08 Limiting kW/ft Limiting kW/ft Model (%) (%) With H-08 Without H-08 Equilibrium 1 15.2 15.7 18.40 18.38 Equilibrium 2 14.2 15.4 18.50 18.43 Transition 1 12.2 12.5 18.81 18.69 Transition 2 14.8 13.8 18.70 18.90

Trip Reactivity A summary of trip reactivity shape limiting margin is given in Table 15. The key safety parameter is the negative reactivity inserted as a function of axial height. Only the most limiting margin to the trip reactivity shape curve is shown below. Without RCCA H-08, the margin to the trip reactivity shape curve is decreased but remains within the analyzed curve as part of the fuel transition analysis. Based on the assessment, there will be sufficient margin to meet the trip reactivity limits with RCCA H- 08 removed and current core design strategies.

Table 15: Trip Reactivity Shape Summary Margin Margin With H-08 Without H-08 Model (%) (%) Equilibrium 1 24.1 7.9 Equilibrium 2 36.3 14.6 Transition 1 31.6 16.5 Transition 2 36.1 14.0

A summary of trip reactivity versus power is given in Table 16. This ensures that as the rods are inserted to the rod insertion limits there remains sufficient trippable worth of control and shutdown banks in the reactor. The reduction in rod worth based on the removal of H-08 does not impact the values utilized in the safety analysis. Based on the assessment, there will be sufficient margin to meet trip reactivity versus power with RCCA H-08 removed and current core design strategies.

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Table 16: Trip Reactivity vs. Power Summary Margin Margin With H-08 Without H-08 Model (%) (%) Equilibrium 1 17.4 5.6 Equilibrium 2 26.8 11.1 Transition 1 21.0 9.7 Transition 2 27.5 11.3

A summary of trip reactivity following rod withdrawal from subcritical is given in Table 17. The reduction in rod worth based on the removal of H-08 does not impact the values utilized in the safety analysis. Based on the assessment, there will be sufficient margin to meet trip reactivity following rod withdrawal from subcritical with RCCA H-08 removed and current core design strategies.

Table 17: Trip Reactivity following Rod Withdrawal from Subcritical Summary Margin Margin With H-08 Without H-08 Model (%) (%) Equilibrium 1 60.7 35.2 Equilibrium 2 82.3 47.7 Transition 1 71.8 47.6 Transition 2 79.1 45.2

Rod Withdrawal Accidents A summary of rod withdrawal accidents is given in Tables 18 and 19. The key safety parameter for rod withdrawal accidents is the reactivity insertion per distance of rod withdrawal. Significant margins exist between the analyzed safety parameter and the calculated cycle value both with and without RCCA H-08 in the core. The results are not significantly impacted by the removal of RCCA H-08. Based on the assessment, there will be sufficient margin to meet rod withdrawal accidents with RCCA H- 08 removed and current core design strategies.

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Table 18: Rod Withdrawal at Power Summary Differential Differential Rod Worth Margin Rod Worth Margin With H-08 Without H-08 Model Burnup (%) (%) BOC 86.3 87.6 Equilibrium 1 EOC 83.8 84.7 BOC 86.1 87.5 Equilibrium 2 EOC 83.8 84.6 BOC 86.1 87.1 Transition 1 EOC 84.7 85.2 BOC 86.1 87.9 Transition 2 EOC 83.7 84.3

Table 19: Rod Withdrawal from Subcritical Summary Differential Differential Rod Worth Margin Rod Worth Margin With H-08 Without H-08 Model Burnup (%) (%) BOC 50.1 60.7 Equilibrium 1 EOC 47.1 49.8 BOC 49.4 61.0 Equilibrium 2 EOC 47.3 49.6 BOC 45.8 52.9 Transition 1 EOC 48.4 50.9 BOC 50.4 62.8 Transition 2 EOC 47.1 49.3

Steamline Break One of the key safety parameters of the steam line break analysis is kW/ft. A summary of HZP steamline break (SLB) is given in Table 20. A summary of the HFP SLB with coincidental rod withdrawal is given in Table 21. The impact of RCCA removal shows negligible impact for HFP steamline break. The HZP kW/ft is decreased in analysis of cores without RCCA H-08 due to a more even power distribution in the core. Based on the assessment, there will be sufficient margin to meet steamline break with RCCA H-08 removed and current core design strategies.

Table 20: HZP SLB Summary Maximum kW/ft Maximum kW/ft Model With H-08 Without H-08 Equilibrium 1 11.57 8.33 Equilibrium 2 10.80 6.53 Transition 1 15.87 8.79 Transition 2 10.46 7.19

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Table 21: HFP SLB with Coincidental Rod Withdrawal Summary Maximum kW/ft Maximum kW/ft Model With H-08 Without H-08 Equilibrium 1 16.66 16.91 Equilibrium 2 16.59 16.91 Transition 1 16.87 17.20 Transition 2 16.83 17.10

3.7 Impact on Operator Actions There is no impact to operator actions or emergency operating procedures (EOPs) resulting from the removal of Control Rod H-08. A cycle-specific evaluation will be performed as part of the core reload design process to determine if changes are required to EOP emergency boration values for a stuck rod. There are no changes required to the UFSAR Chapter 15 accident analysis inputs to the EOPs and no new operator actions are created.

4.0 References 1, NRC Letter “Sequoyah Nuclear Plant, Unit 1 – Issuance of Exigent Amendment No. 348 to Operate One Cycle with One Control Rod Removed (EPID L-2019-LLA-0239),” November 2019 (ADAMS Accession Number ML19319C831). 2. NRC Letter “Sequoyah Nuclear Plant, Unit 2 – Issuance of Exigent Amendment No. 342 to Operate One Cycle with One Control Rod Removed (EPID L-2020-LLA-0078),” April 2020 (ADAMS Accession Number ML20108F049). 3. Westinghouse Report WCAP-9272-P-A, Revision 0, “Westinghouse Reload Safety Evaluation Methodology,” July 1985. 4. Westinghouse Report WCAP-16045-P-A, Revision 0, “Qualification of the Two-Dimensional Transport Code PARAGON,” August 2004. 5. Westinghouse Report WCAP-16045-P-A, Addendum 1-A, Revision 0, “Qualification of the NEXUS Nuclear Data Methodology,” August 2007. 6. Westinghouse Report WCAP-10965-P-A, Revision 0, “ANC: A Westinghouse Advanced Nodal Computer Code,” September 1986. 7. Westinghouse Report WCAP-13524-P-A, Revision 1, “APOLLO – A One Dimensional Neutron Diffusion Theory Program,” August 1994. 8. Westinghouse Report WCAP-10216-P-A, Revision 1A, “Relaxation of Constant Axial Offset Control. FQ Surveillance Technical Specification,” February 1994.

9. Westinghouse Report WCAP-17661-P-A, Revision 1, “Improved RAOC and CAOC FQ Surveillance Technical Specifications,” February 2019.

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Enclosure 1

Evaluation of the Transition to Westinghouse RFA-2 Fuel

ATTACHMENT 10

Sequoyah Safety Analysis UFSAR Impact Summary for the WEC RFA-2 Fuel Transition

CNL-20-014 Attachment 10

Sequoyah Safety Analysis UFSAR Impact Summary for the WEC RFA-2 Fuel Transition

UFSAR Computer Codes and Section Event / Analysis Description Initial Conditions Analysis Conclusion 15.2.1 Uncontrolled RCCA Bank Withdrawal from Subcritical TWINKLE (spatial neutronic kinetics) The core and the RCS are not adversely Condition – Condition II FACTRAN (fuel rod transient) affected. The reactor is tripped on the VIPRE-01 (transient DNBR) The analysis of the uncontrolled RCCA bank withdrawal from power range high neutron flux trip low subcritical accident is performed in three stages. First, a spatial MTC conservative BOC value setpoint. The worst combination of neutron kinetics computer code, TWINKLE, is used to calculate MDC -- thermal power and coolant temperature the core average nuclear power transient, including the various Doppler least negative Doppler defect result in a DNBR greater than the SAL and core feedback effects (i.e., Doppler and moderator reactivity). Core Power 0 MWt maximum fuel temperature has substantial FACTRAN then uses the average nuclear power calculated by margin to the onset of fuel melting. Thus, TWINKLE and performs a fuel rod transient heat transfer no fuel or cladding damage is predicted as calculation to determine the average heat flux and temperature a result of this transient. transients. Finally, the peak core-average heat flux calculated by FACTRAN is used in VIPRE-01 for transient DNBR calculations. 15.2.2 Uncontrolled RCCA Bank Withdrawal at Power – Condition II LOFTRAN (transient response) The results confirm that the high neutron IOX[DQG27ǻ7WULSIXQFWLRQVSURYLGH The uncontrolled RCCA bank withdrawal at power event was MTC -- analyzed with the LOFTRAN computer code to determine the MDC DQGǻNJPFF adequate protection over the entire range plant transient conditions during/following the event. Doppler lower and upper of possible reactivity insertion rates as the Core Power 3467 and 3491 MWt minimum calculated DNBR is always greater than the safety analysis limit value and the peak core heat flux is less than the overpower limit of 121 percent RTP. In addition, the analysis results demonstrate that the peak system RCS pressure does not exceed 110 percent of the design pressure. The peak main steam system (MSS) pressure is bounded by the loss of load/turbine trip event and is not explicitly evaluated for this event.

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UFSAR Computer Codes and Section Event / Analysis Description Initial Conditions Analysis Conclusion 15.2.3 RCCA Misalignment (Dropped Rod) – Condition II LOFTRAN (transient statepoints) A detailed evaluation was performed using VIPRE-01 (transient DNBR) The dropped control rod assemblies or control rod assembly generic dropped rod statepoints that are banks event is analyzed using a generically bounding process. applicable to Sequoyah Units 1 and 2. MTC -- This analysis demonstrates that DNB and Bounding transient statepoints from the LOFTRAN code, which MDC 0 ǻk/gm/cc cover a matrix of reactivity combinations, were compiled for Doppler upper fuel melt does not occur. These statepoints various plant designs as part of a Westinghouse Owners Group Core Power 3467 MWt are determined assuming no control system (WOG) Program. Additional sets of statepoints were created to actions that would reduce power and no address changes in the rod control system parameters that have reactor trip. occurred since the WOG Program was finished. These generic statepoints are evaluated on a plant-by-plant basis to confirm their applicability with respect to both the plant design and operating conditions. To address the fuel transition, the generic statepoints applicable to Sequoyah Units 1 and 2 are evaluated to confirm that they remain valid for the new fuel product and current plant-specific conditions.

15.2.4 Uncontrolled Boron Dilution – Condition II Hand Calculations (Modes 1 and 2) The results of the evaluation demonstrate that the operators have at least 15 minutes Boron dilution events during power operation (Mode 1), startup N/A (Mode 2), and refueling (Mode 6) are explicitly addressed for from the time of an alarm to terminate the Sequoyah Units 1 and 2. The high flux at shutdown alarm, RCS dilution before a complete loss of which is controlled in accordance with Technical Specification shutdown margin. 3.3.9, is available to alert operators to dilutions in the shutdown modes (Modes 3-5). No calculation is performed for Mode 6, since the event is administratively precluded by Technical Specification 3.9.2. Therefore, only Modes 1 and 2 are explicitly analyzed for the fuel transition. The analyses performed for Modes 1 and 2 are hand calculations to determine the amount of time available for operator mitigation of the

boron dilution event prior to the complete loss of shutdown margin.

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UFSAR Computer Codes and Section Event / Analysis Description Initial Conditions Analysis Conclusion 15.2.5 Partial Loss of Forced Reactor Coolant Flow – Condition II LOFTRAN (transient loop/core flow) The reactor is tripped on low loop flow. FACTRAN (fuel rod transient) The partial loss of flow event is analyzed with three computer The analysis demonstrates that the DNBR VIPRE-01 (transient DNBR) codes. First, the LOFTRAN code is used to calculate the loop does not decrease below the SAL. and core flow during the transient, the time of reactor trip based MTC -- Therefore, no fuel or cladding damage is on the calculated flows, the nuclear power transient, and the MDC 0 ǻk/gm/cc predicted. primary system pressure and temperature transients. The Doppler upper FACTRAN code is then used to calculate the heat flux transient Core Power 3467 MWt based on the nuclear power and flow from LOFTRAN. Finally, the VIPRE-01 code is used to calculate the departure from DNBR during the transient, based on the heat flux from FACTRAN and the flow from LOFTRAN. The WRB-2M correlation is used for DNBR calculation.

15.2.6 Startup of an Inactive Reactor Coolant Loop – Condition II N/A Precluded by Technical Specifications The Sequoyah Units 1 and 2 Technical Specification limiting 3.4.4, which requires that all four RCPs be condition for operation (LCO) 3.4.4 requires that all four reactor operational in Modes 1 and 2. coolant pumps (RCPs) be operating in Modes 1 and 2; therefore, power operation with an inactive loop is precluded. This event was originally included in the UFSAR when operation with a loop out of service (i.e., N-1 operation) was considered. It remains within the UFSAR for historical purposes but is not actively maintained.

Enclosure 1 Attachment 10 - 3 of 13

UFSAR Computer Codes and Section Event / Analysis Description Initial Conditions Analysis Conclusion 15.2.7 Loss of External Electrical Load / Turbine Trip (LOL/TT) – LOFTRAN (transient loop/core flow) Three analyses are performed to determine Condition II the minimum DNBR the maximum RCS MTC -- The analysis used the LOFTRAN computer code. For a MDC ǻNJPFF pressure and the maximum MSS pressure. (LOL/TT) event, the behavior of the unit is analyzed as a Doppler lower The reactor is tripped on either complete loss of steam load from full power without a direct Core Power 3467 and 3491 MWt RYHUWHPSHUDWXUH¨7RUKLJKSUHVVXUL]HU reactor trip. This assumption is made to show the adequacy of pressure. The analyses demonstrate that the pressure relieving devices and to demonstrate core the plant design is such that a total loss of protection margins, by delaying reactor trip until conditions in external electrical load without a direct the RCS result in a trip due to other signals. Thus, the analysis reactor trip on TT presents no hazard to the assumes a worst-case transient. integrity of the RCS or the MSS and no fuel failure occurs. Three cases were analyzed for a LOL/TT event from full-power conditions: This analysis determines the peak RCS and MSS pressure for all UFSAR events. Maximum steam generator tube plugging (SGTP) with automatic pressurizer pressure control (DNB case) Maximum SGTP without automatic pressurizer pressure control (RCS pressure case) Minimum SGTP with automatic pressurizer pressure control (MSS pressure case)

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UFSAR Computer Codes and Section Event / Analysis Description Initial Conditions Analysis Conclusion 15.2.8 Loss of Normal Feedwater – Condition II LOFTRAN (transient loop/core flow) The reactor is tripped on low steam A detailed analysis using the LOFTRAN computer code is generator water level. The analysis MTC -- demonstrates that the AFW system performed to determine the plant transient conditions following MDC 0 ǻk/gm/cc a LONF. Doppler upper capacity is large enough to prevent Core Power 3491 MWt overheating of the RCS such that reactor coolant water is not relieved from the pressurizer relief or safety valves as a result of the event.

15.2.9 Loss of Offsite Power to the Station Auxiliaries – Condition II LOFTRAN (transient loop/core flow) The reactor is tripped on low steam generator water level. The analysis A detailed analysis using the LOFTRAN computer code is MTC -- performed to determine the plant transient conditions following MDC 0 ǻk/gm/cc demonstrates that the AFW system a LOOP event. Doppler upper capacity is large enough to prevent Core Power 3491 MWt overheating of the RCS such that reactor coolant water is not relieved from the pressurizer relief or safety valves as a result of the event.

15.2.10 Excessive Heat Removal due to Feedwater Malfunction – LOFTRAN (transient loop/core flow) The reactor is tripped on high steam Condition II generator water level in the steam MTC -- The excessive heat removal due to feedwater system MDC ǻNJPFF generator with the failed feedwater control malfunction (feedwater control valve to one steam generator Doppler lower valve). The analysis shows that the failure going full open) is analyzed using the detailed digital computer Core Power 3467 MWt of a feedwater control valve does not result code LOFTRAN. in DNB.

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UFSAR Computer Codes and Section Event / Analysis Description Initial Conditions Analysis Conclusion 15.2.11 Excessive Load Increase – Condition II LOFTRAN (transient loop/core flow) The event is initiated by an increase in the main steam system flow rate, which results Four cases are analyzed with the LOFTRAN code to cover both MTC -- minimum and maximum reactivity feedback conditions, with MDC DQGǻNJPFF in overcooling the RCS and a decrease in automatic and manual rod control. Doppler lower and upper the MSS and RCS pressure. The analysis Core Power 3467 MWt demonstrates that the minimum DNBR At beginning of life (BOL), the core has the least-negative during the transient will not drop below the moderator temperature coefficient (MTC) and therefore the least safety analysis limit. No reactor trip is inherent transient capability. At end of life (EOL), the MTC has credited for this event. its highest absolute value. This results in the largest amount of reactivity feedback due to changes in coolant temperature.

15.2.12 Accidental Depressurization of the Reactor Coolant System – LOFTRAN (transient loop/core flow) The reactor trips on low pressurizer Condition II pressure. The analysis shows that the for MTC -- A detailed analysis using the LOFTRAN computer code is MDC ǻNJPFF the most severe RCS depressurization performed to determine the plant transient conditions. The Doppler lower event meets the DNB SAL and thus the transient is simulated by opening one PSV at time “zero.” The Core Power 3467 MWt fuel cladding integrity is maintained. resulting RCS depressurization is more severe than what would occur from a pressurizer relief or spray valve actuation; and thus provides a bounding analysis. 15.2.13 Accidental Depressurization of the Main Steam System – LOFTRAN (transient loop/core flow) The analysis demonstrated that the Condition II VIPRE-01 (transient DNBR) accidental depressurization of the MSS is A detailed analysis using the LOFTRAN computer code is MTC function of MD bounded by the rupture of a main steam performed to determine the plant transient conditions following MDC -- line event (UFSAR events 15.3.7 and a main steam system depressurization. Doppler varies 15.4.2.1) where it was shown the minimum Core Power 0 MWt DNBR remains above the SAL.

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UFSAR Computer Codes and Section Event / Analysis Description Initial Conditions Analysis Conclusion 15.2.14 Spurious Operation of the Safety Injection System at Power – LOFTRAN (transient loop/core flow) Spurious SI operation without immediate Condition II reactor trip does not present any hazard to MTC -- the integrity of the fuel. Operator actions The inadvertent operation of the ECCS at power analysis does MDC ǻNJPFF not lead to a serious challenge of the DNB SAL. The decrease Doppler lower prevent the pressurizer from reaching a in core power and RCS average temperature more than offset Core Power 3491 MWt water-solid condition. Thus, no water is the decrease in RCS pressure such that the minimum calculated relieved through the pressurizer PORVs or DNBR occurs at the start of the transient. Therefore, explicit PSVs. This precludes possible damage to analysis for DNB is not required. the valves, which could potentially generate a more serious plant condition. The non-escalation criterion is addressed for the Sequoyah units by calculating a pressurizer fill time for the inadvertent operation of the ECCS at power event. The calculation demonstrates that the time required to fill the pressurizer exceeds the operator action time of 15 minutes to terminate SI flow.

15.3.1 Loss of Reactor Coolant from Small Ruptured Pipes or from WCOBRA/TRAC-TF2 (T/H analysis) The analysis demonstrates that all relevant Cracks in Large Pipes, which Actuates Emergency Core 10 CFR 50.46 acceptance criteria are met. Cooling System – Condition III FQ 2.65 F¨+ 1.7 The analysis is performed using the FULL SPECTRUM™ Core Power ”0:W loss-of-coolant accident (FSLOCA™) evaluation model (EM), r 0% uncertainty using the WCOBRA/TRAC-TF2 thermal-hydraulic (T/H) analysis code.

15.3.2 Minor Secondary Pipe Breaks – Condition III Bounded by UFSAR Sections 15.2.13 Not analyzed, bounded by UFSAR and 15.4.2.1 Sections 15.2.13 and 15.4.2.1

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UFSAR Computer Codes and Section Event / Analysis Description Initial Conditions Analysis Conclusion 15.3.3 Inadvertent Loading of a Fuel Assembly into an Improper LEOPARD (cross-sections) This event is characterized by the Position – Condition III TURTLE (core power distributions) misplacement of a fuel assembly in the For several fuel assembly loading patterns, cross sections are -- reactor core. No system interaction or MTC effects are included in the event analyses. determined by LEOPARD and input into TURTLE to determine MDC N/A core power distributions. A discrete representation is used Doppler N/A The analyses confirm that the resulting * wherein each individual fuel rod is described by a mesh interval. Core Power 3411 power distribution effects will either be The power distributions for a correctly loaded core assembly are readily detected by the in-core moveable * based on the specified enrichments. These events, performed at a rated thermal detector system or will cause a sufficiently power of 3411 MWt, have been evaluated. The evaluations demonstrate that the analysis of small perturbation to be acceptable within record for each of these events continue to be the uncertainties allowed between nominal applicable to the uprated power of 3455 MWt. and design power shapes.

15.3.4 Complete Loss of Forced Reactor Coolant Flow – Condition III LOFTRAN (transient loop/core flow) The limiting complete loss of flow FACTRAN (fuel rod transient) transient is analyzed as a loss of four RCPs The transients are analyzed with three computer codes. First, VIPRE-01 (transient DNBR) the LOFTRAN code is used to calculate the loop flow, core resulting in a nearly immediate reactor trip flow, the time of reactor trip, the nuclear power transient, and MTC -- on RCP underfrequency. The analysis the primary system pressure and coolant temperature transients. MDC 0 ǻk/gm/cc demonstrates the integrity of the core is The FACTRAN code is then used to calculate the heat flux Doppler upper maintained as the DNBR remains above transient based on the nuclear power and flow from LOFTRAN. Core Power 3467 MWt the SAL. The loss-of-flow event results in Finally, the VIPRE-01 code is used to calculate the DNBR an increase in RCS and MSS pressures, but during the transient based on the heat flux from FACTRAN and these pressure increases do not challenge flow from LOFTRAN. The WRB-2M correlation is used for the integrity of the RCS and MSS. DNBR calculation. The total loss of flow event results in the minimum DNBR for UFSAR Chapter 15 events.

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UFSAR Computer Codes and Section Event / Analysis Description Initial Conditions Analysis Conclusion 15.3.6 Single Rod Cluster Control Assembly Withdrawal at Full Power LEOPARD (cross-sections) For both cases considered, indicators and – Condition III TURTLE (core power distributions) alarms would alert the operator to the THINC (transient DNBR) Power distributions within the core are calculated by the malfunction before DNB could occur. TURTLE based on macroscopic cross section generated by MTC -- The analyses demonstrate that <5% of the LEOPARD. The peaking factors calculated by TURTLE are MDC N/A fuel rods experience DNB. Doppler N/A then used by THINC to calculate the minimum DNB for the 3411* event. Two cases have been considered with the reactor in Core Power

manual control mode and in automatic control mode. * These events, performed at a rated thermal power of 3411 MWt, have been evaluated. The evaluations demonstrate that the analysis of record for each of these events continue to be applicable to the uprated power of 3455 MWt.

15.3.7 Steam Line Break Coincident with Rod Withdrawal at Power – LOFTRAN (transient loop/core flow) The reactor trips on overpower ¨7DQGWKH Condition III VIPRE-01 (transient DNBR) analysis demonstrates that cladding damage will not occur and that the RCS A detailed analysis was performed using the LOFTRAN MTC +5 pcm/°F computer code to determine the plant transient conditions MDC ǻNJPFF and main steam system pressure limits are following a main steam line rupture at full power coincident Doppler most negative doppler defect not challenged. with automatic rod withdrawal at the maximum postulated rate. Core Power 3467 MWt Core heat flux, RCS loop inlet temperatures, pressure, and core flow from LOFTRAN are used as input to the DNB analysis and the calculation of the peak linear heat rate (kW/ft). A detailed core analysis was performed using the ANC code to confirm the validity of the LOFTRAN-predicted reactivity feedback model. The core models developed in ANC were also used to calculate the power peaking factors for input to the DNB analysis and the calculation of the peak kW/ft. The detailed thermal and hydraulic digital computer code VIPRE-01 was used to calculate the DNBR for the limiting time in the transient. The DNBR calculations were performed using the WRB-2M DNB correlation and RTDP methodology.

Enclosure 1 Attachment 10 - 9 of 13

UFSAR Computer Codes and Section Event / Analysis Description Initial Conditions Analysis Conclusion 15.4.1 Major Reactor Coolant System Pipe Ruptures (Loss of Coolant WCOBRA/TRAC-TF2 (T/H analysis) The analysis demonstrates that all relevant Accident) – Condition IV LOTIC2 (containment pressure) 10 CFR 50.46 acceptance criteria are met.

The analysis is performed using the FULL SPECTRUM™ FQ 2.65 The LOCA analysis determines the loss-of-coolant accident (FSLOCA™) evaluation model (EM), F¨+ 1.7 limiting FQ. using the WCOBRA/TRAC-TF2 thermal-hydraulic (T/H) Core Power ”0:W analysis code. r 0% uncertainty

15.4.2.1 Rupture of a Main Steam Line (Hot Zero Power Steamline LOFTRAN (transient loop/core flow) The analysis demonstrates that the Break) – Condition IV VIPRE-01 (transient DNBR) minimum DNBR remains above the SAL. A detailed analysis using the LOFTRAN computer code is MTC function of moderator density This event determines the most negative performed to determine the plant transient conditions following MDC -- moderator temperature coefficient. a main steam line break. The code models the core neutron Doppler varies Low steam line pressure causes the Core Power 0 MWt kinetics, RCS, pressurizer, SGs, SIS and the AFW system initiation of SI and reactor trip. (AFWS). The code computes pertinent variables, including the core heat flux, RCS temperature and pressure. A conservative selection of those conditions is then used to develop core models using the ANC code, which provide input to the detailed thermal and hydraulic digital computer code, VIPRE-01, to

determine the minimum calculated DNBR.

15.4.2.2 Major Rupture of a Main Feedwater Pipe (Feedline Break) – LOFTRAN (transient loop/core flow) The results of this analysis show that for Condition IV the postulated feedline rupture, the MTC 0 and +5 pcm/°F assumed AFWS capacity is adequate to The transient response following a feedwater pipe rupture event MDC ǻNJPFF remove core decay heat, to prevent is calculated by a detailed digital simulation of the plant. The Doppler lower and upper analysis models a simultaneous loss of main feedwater to all Core Power 3491 MWt overpressurizing the RCS and to prevent SGs and subsequent blowdown of the faulted SG. the uncovering of the reactor core. A detailed analysis using the LOFTRAN computer code is The reactor trips on low-low SG narrow performed to determine the plant transient conditions following range level. a feedwater system pipe rupture.

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UFSAR Computer Codes and Section Event / Analysis Description Initial Conditions Analysis Conclusion 15.4.3 Steam Generator Tube Rupture – Condition IV LOFTRAN (transient response) The loss of reactor coolant to the faulted Hand Calculations The licensing basis steam generator tube rupture analysis steam generator secondary side results in a consists of a 30-minute LOFTRAN analysis and a long-term Time release is terminated from faulted reactor trip on low pressurizer pressure mass and energy balance. Changes in the analysis inputs, which steam generator relief valves: 30 minutes followed by a low pressurizer pressure safety injection signal. No DNB analysis LQFOXGHXSGDWHGRYHUWHPSHUDWXUHǻ7VHWSRLQWFRQVWDQWV.DQG Time release is terminated from intact steam K3, have been assessed for the reload transition with the generator relief valves: 8 hours is performed for this event. conclusion that the input to dose is not affected by the input Core Power: 3479 changes. The analysis of the steam generator tube rupture assumes the loss of offsite power and hence involves the release of radioactive steam from the secondary system directly to the atmosphere. Hand calculations are performed to determine the total release of steam through the steam generator relief valves. 15.4.4 Single Reactor Coolant Pump Locked Rotor (Locked LOFTRAN (transient response) The analysis demonstrates that for a locked Rotor/Shaft Break) – Condition IV FACTRAN (hot spot response) rotor event the RCS pressure remains VIPRE-01 (transient DNBR) The locked rotor transient is analyzed with three primary below the faulted condition stress limit and computer codes. First, the LOFTRAN computer code is used to MTC -- the hot spot cladding temperature and fuel calculate the resulting loop and core flow transients following MDC ǻNJPFF centerline temperature remain below the the pump seizure, the time of reactor trip based on the loop flow Doppler upper corresponding limit values. The transient, the nuclear power following reactor trip, and to Core Power 3467 and 3491 MWt percentage of rods in DNB is less than determine the peak pressure. The thermal behavior of the fuel 10 percent of the fuel rods in the core. located at the core hot spot is investigated by using the FACTRAN code using the core flow and the nuclear power calculated by LOFTRAN. The FACTRAN code includes a film boiling heat transfer coefficient. The VIPRE-01 code is then used to calculate the rods-in-DNB using the results of the LOFTRAN and FACTRAN calculations along with the associated initial condition assumptions.

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UFSAR Computer Codes and Section Event / Analysis Description Initial Conditions Analysis Conclusion 15.4.6 Rod Control Cluster Assembly (RCCA) Ejection1 – Condition TWINKLE (spatial neutronic kinetics) The analysis demonstrates that there is no IV FACTRAN (fuel rod transient) fuel dispersal into the coolant or consequential damage to the RCS and The rod ejection transient analysis is performed in two stages, MTC +5.0 pcm/°F (HZP-BOL) first an average core channel calculation and then a hot region 0.0 pcm/°F (HFP-BOL) long-term core cooling will not be calculation. The average core calculation, performed by the -16.817 pcm/°F (HZP-EOL) impaired. TWINKLE computer code, uses spatial neutron-kinetics -22.920 pcm/°F (HFP-EOL) The event trips on high neutron flux. methods to determine the average power generation with time MDC -- Doppler least negative Doppler defect This analysis determines the maximum including the various total core feedback effects, i.e., Doppler * control assembly worth. reactivity and moderator reactivity. Fuel enthalpy and Core Power 0 and 3479 MWt temperature transients at the hot spot are then determined using * The RCCA Ejection event models core thermal the FACTRAN computer code, which multiplies the average power instead of NSSS thermal power. core energy generation by the hot channel factor and performs a fuel rod transient heat transfer calculation. The power distribution calculated without feedback is conservatively assumed to persist throughout the transient.

1 The rod ejection analysis followed the methodology described in WCAP-7588 and shows compliance with the limits in RG 1.77. At the time of completion of this safety analysis, RG 1.77 was the regulatory guidance for the rod ejection transient. Shortly after this work was completed, the guidance in RG 1.77 was superseded by that in RG 1.236, which contains more restrictive limits (e.g., fuel rod cladding failure thresholds and allowable limits on damaged core coolability) than RG 1.77.

Westinghouse has an NRC approved 3D kinetics methodology (3DRE) documented in WCAP-15806-PA to analyze a rod ejection accident per the guidance in RG 1.236. Westinghouse has used this methodology to perform rod ejection analyses for several plants. Based on the results of the most recent analyses Westinghouse expects no or very few fuel failures using RG 1.236. If fuel failures were predicted these would be expected to not exceed the dose analysis assumptions of the plants.

Similar results are expected for Sequoyah for the transition cycles and equilibrium cycles because the core reactivity parameters (e.g. control rod worth and Doppler reactivity), core power level and operating parameters for Sequoyah are similar to the cores analyzed in these most recent rod ejection analyses. Therefore, the analysis of the rod ejection accident supporting the transition to Westinghouse RFA-2 fuel (using RG 1.77 and WCAP-7588) predicts more fuel failures than would be expected from a rod ejection accident for the same plant analyzed using the WCAP-15806-P-A methodology and the guidance and criteria in RG 1.236.

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Nomenclature AFW auxiliary feedwater AFWS AFW System BOL beginning of life CFR Code of Federal Regulations DNB departure from nucleate boiling DNBR departure from nucleate boiling ratio EOL end of life FSLOCA™ FULL SPECTRUM™ loss-of-coolant accident LCO limiting condition for operation LOCA loss of coolant accident LOL/TT loss of load / turbine trip LONF loss of normal feedwater MDC moderator density coefficient MTC moderator temperature coefficient MSS main steam system 27ǻ7 overtemperature ǻ7 PORV power operated relief valve PSV pressurizer safety valve RCCA rod cluster control assembly RCP reactor coolant pump RCS reactor coolant system RTDP revised thermal design procedure SAL Safety Analysis Limit SG steam generator SGTP steam generator tube plugging SI safety injection TT turbine trip RFA-2 Robust Fuel Assembly-2 UFSAR Updated Final Safety Analysis Report WEC Westinghouse Electric Company WOG Westinghouse Owners Group

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Enclosure 2

Application of Westinghouse FULL SPECTRUM LOCA Evaluation Model to the Sequoyah Nuclear Plant (Proprietary)

CNL-20-014 Enclosure 3

Application of Westinghouse FULL SPECTRUM LOCA Evaluation Model to the Sequoyah Nuclear Plant (Non-Proprietary)

CNL-20-014 ENCLOSURE 3

APPLICATION OF WESTINGHOUSE FULL SPECTRUM LOCA EVALUATION MODEL TO THE SEQUOYAH NUCLEAR PLANT

(Non-Proprietary)

(47 pages, including cover page)

© 2020 Westinghouse Electric Company LLC All Rights Reserved Westinghouse Non-Proprietary Class 3 Page 1 of 46

APPLICATION OF WESTINGHOUSE FULL SPECTRUM LOCA EVALUATION MODEL TO THE SEQUOYAH NUCLEAR PLANT

1.0 INTRODUCTION

An analysis with the FULL SPECTRUM™1loss-of-coolant accident (FSLOCA™) evaluation model (EM) has been completed for the Sequoyah Nuclear Plant. The )6/2&$ EM (Reference 1) was developed to address the full spectrum of loss-of-coolant accidents (LOCAs) which result from a postulated break in the reactor coolant system (RCS) of a pressurized water reactor (PWR). The break sizes considered in the Westinghouse )6/2&$ EM include any break size in which break flow is beyond the capacity of the normal charging pumps, up to and including a double ended guillotine (DEG) rupture of an RCS cold leg with a break flow area equal to two times the pipe area, including what traditionally are defined as Small and Large Break LOCAs. The break size spectrum is divided into two regions. Region I includes breaks that are typically defined as Small Break LOCAs (SBLOCAs). Region II includes break sizes that are typically defined as Large Break LOCAs (LBLOCAs). The )6/2&$ EM explicitly considers the effects of fuel pellet thermal conductivity degradation (TCD) and other burnup-related effects by calibrating to fuel rod performance data input generated by the PAD5 code (Reference 2), which explicitly models TCD and is benchmarked to high burnup data in Reference 2. The fuel pellet thermal conductivity model in the WCOBRA/TRAC-TF2 code used in the )6/2&$ EM explicitly accounts for pellet TCD. Three of the Title 10 of the Code of Federal Regulations (CFR) 50.46 criteria (peak cladding temperature (PCT), maximum local oxidation (MLO), and core-wide oxidation (CWO)) are considered directly in the )6/2&$ EM. A high probability statement is developed for the PCT, MLO, and CWO that is needed to demonstrate compliance with 10 CFR 50.46 acceptance criteria (b)(1), (b)(2), and (b)(3) (Reference 3) via statistical methods. The MLO is defined as the sum of pre-transient corrosion and transient oxidation consistent with the position in Information Notice 98-29 (Reference 4). The coolable geometry acceptance criterion, 10 CFR 50.46 (b)(4), is assured by compliance with acceptance criteria (b)(1), (b)(2), and (b)(3), and demonstrating that fuel assembly grid deformation due to combined seismic and LOCA loads does not extend to the in-board fuel assemblies such that a coolable geometry is maintained. The )6/2&$ EM has been generically approved by the Nuclear Regulatory Commission (NRC) for Westinghouse 3-loop and 4-loop plants with cold leg Emergency Core Cooling System (ECCS) injection (Reference 1). Since Sequoyah Units 1 and 2 are Westinghouse designed 4-loop plants with cold leg ECCS injection, the approved method is applicable. Information required to address Limitations and Conditions 9 and 10 of the NRC’s Safety Evaluation Report (SER) for Reference 1 was docketed in Reference 11 in support of application of the )6/2&$ EM to Westinghouse 4-loop plants. This report summarizes the application of the Westinghouse )6/2&$ EM to Sequoyah Units 1 and 2. The application of the )6/2&$ EM to Sequoyah Units 1 and 2 is consistent with the NRC-approved methodology (Reference 1), with exceptions identified under Limitation and Condition Number 2 in

FULL SPECTRUM and FSLOCA are trademarks of Westinghouse Electric Company LLC, its affiliates and/or its subsidiaries in the United States of America and may be registered in other countries throughout the world. All rights reserved. Unauthorized use is strictly prohibited. Other names may be trademarks of their respective owners. Westinghouse Non-Proprietary Class 3 Page 2 of 46

Section 2.3. The application of the )6/2&$ EM to Sequoyah Units 1 and 2 is consistent with the conditions and limitations as identified in the NRC’s SER for Reference 1, and is also applicable for the Sequoyah Units 1 and 2 plant designs and operating conditions. A single composite model was developed for both Sequoyah Units 1 and 2. Both Tennessee Valley Authority and its analysis vendor (Westinghouse) have interface processes which identify plant configuration changes potentially impacting safety analyses. These interface processes, along with Westinghouse internal processes for assessing EM changes and errors, are used to identify the need for LOCA analysis impact assessments. The major plant parameter and analysis assumptions used in the Sequoyah Units 1 and 2 analysis with the )6/2&$ EM are provided in Tables 1 through 3.

2.0 METHOD OF ANALYSIS

2.1 )8//63(&7580LOCA Evaluation Model Development

When the Final Acceptance Criteria (FAC) governing the LOCA for Light Water Reactors was issued in 10 CFR 50.46 (Reference 3), the industry recognized that the stipulations of Appendix K were highly conservative. That is, using the then accepted analysis methods, the performance of the ECCS would be conservatively underestimated, resulting in predicted PCTs much higher than expected. In 1988, the NRC Staff amended the requirements of 10 CFR 50.46 and Appendix K, “ECCS Evaluation Models,” to permit the use of a realistic EM to analyze the performance of the ECCS during a hypothetical LOCA (Reference 6). This decision was based on an improved understanding of LOCA thermal-hydraulic phenomena gained by extensive research programs. Under the amended rules, best- estimate thermal-hydraulic models may be used in place of models with Appendix K features. The rule change also requires, as part of the LOCA analysis, an assessment of the uncertainty of the best-estimate calculations. It further requires that this analysis uncertainty be included when comparing the results of the calculations to the prescribed acceptance criteria of 10 CFR 50.46. Further guidance for the use of best-estimate codes is provided in Regulatory Guide (RG) 1.157 (Reference 7). When the )6/2&$ EM was being developed, the NRC issued RG 1.203 (Reference 8) which expands on the principles of RG 1.157, while providing a more systematic approach to the development and assessment process of a PWR accident and safety analysis EM. Therefore, the development of the )6/2&$ EM followed the Evaluation Model Development and Assessment Process (EMDAP), which is documented in RG 1.203. While RG 1.203 expands upon RG 1.157, there are certain aspects of RG 1.157 which are more detailed than RG 1.203; therefore, both RGs were used for the development of the )6/2&$ EM.

2.2 WCOBRA/TRAC-TF2 Computer Code

The )6/2&$ EM (Reference 1) uses the WCOBRA/TRAC-TF2 code to analyze the system thermal- hydraulic response for the full spectrum of break sizes. WCOBRA/TRAC-TF2 was created by combining a 1D module (TRAC-P) with a 3D module (based on Westinghouse modified COBRA-TF). The 1D and Westinghouse Non-Proprietary Class 3 Page 3 of 46

3D modules include an explicit non-condensable gas transport equation. The use of TRAC-P allows for the extension of a two-fluid, six-equation formulation of the two-phase flow to the 1D loop components. This new code is WCOBRA/TRAC-TF2, where “TF2” is an identifier that reflects the use of a three-field (TF) formulation of the 3D module derived by COBRA-TF and a two-fluid (TF) formulation of the 1D module based on TRAC-P. This best-estimate computer code contains the following features: 1. Ability to model transient three-dimensional flows in different geometries inside the reactor vessel 2. Ability to model thermal and mechanical non-equilibrium between phases 3. Ability to mechanistically represent interfacial heat, mass, and momentum transfer in different flow regimes 4. Ability to represent important reactor components such as fuel rods, steam generators (SGs), reactor coolant pumps (RCPs), etc. A detailed assessment of the computer code WCOBRA/TRAC-TF2 was made through comparisons to experimental data. These assessments were used to develop quantitative estimates of the ability of the code to predict key physical phenomena for a LOCA. Modeling of a LOCA introduces additional uncertainties which are identified and quantified in the plant-specific analysis. The reactor vessel and loop noding scheme used in the )6/2&$ EM is consistent with the noding scheme used for the experiment simulations that form the validation basis for the physical models in the code. Such noding choices have been justified by assessing the model against large and full scale experiments.

2.3 Compliance with )6/2&$ EM Limitations and Conditions

The NRC’s SER for Reference 1 contains 15 limitations and conditions on the NRC-approved )6/2&$ EM. A summary of each limitation and condition and how it was met is provided below.

Limitation and Condition Number 1 Summary The )6/2&$ EM is not approved to demonstrate compliance with 10 CFR 50.46 acceptance criterion (b)(5) related to the long-term cooling. Compliance The analysis for Sequoyah Units 1 and 2 with the )6/2&$ EM is only being used to demonstrate compliance with 10 CFR 50.46 (b)(1) through (b)(4). Westinghouse Non-Proprietary Class 3 Page 4 of 46

Limitation and Condition Number 2 Summary The )6/2&$ EM is approved for the analysis of Westinghouse-designed 3-loop and 4-loop PWRs with cold-side injection. Analyses should be executed consistent with the approved method, or any deviations from the approved method should be described and justified. Compliance Sequoyah Units 1 and 2 are Westinghouse-designed 4-loop PWRs with cold-side injection, so it is within the NRC-approved methodology. The analysis for Sequoyah Units 1 and 2 utilized the NRC-approved )6/2&$ methodology, except for the changes which were previously transmitted to the NRC pursuant to 10 CFR 50.46 in LTR-NRC-18-30 (Reference 5).

Limitation and Condition Number 3 Summary For Region II, the containment pressure calculation will be executed in a manner consistent with the approved methodology (i.e., the COCO or LOTIC2 model will be based on appropriate plant-specific design parameters and conditions, and engineered safety features which can reduce pressure are modeled). This includes utilizing a plant-specific initial containment temperature, and only taking credit for containment coatings which are qualified and outside of the break zone-of-influence. Compliance The containment pressure calculation for the Sequoyah Units 1 and 2 analysis was performed consistent with the NRC-approved methodology. Appropriate design parameters and conditions were modeled, as were the engineered safety features which can reduce the containment pressure. A plant-specific initial temperature associated with normal full-power operating conditions was modeled, and no coatings were credited on any of the containment structures.

Limitation and Condition Number 4 Summary The decay heat uncertainty multiplier will be [ ]a,c The analysis simulations for the )6/2&$ EM will not be executed for longer than 10,000 seconds following reactor trip unless the decay heat model is appropriately justified. The sampled values of the decay heat uncertainty multiplier for the cases which produced the Region I and Region II analysis results will be provided in the analysis submittal in units of sigma and absolute units. Compliance Consistent with the NRC-approved methodology, the decay heat uncertainty multiplier was [ ]a,c for the Sequoyah Units 1 and 2 analysis. The analysis simulations were all executed for no longer than 10,000 seconds following reactor trip. The sampled values of the decay heat uncertainty multiplier for the cases which produced the Region I and Region II analysis results have been provided in units of sigma and approximate absolute units in Table 7. Westinghouse Non-Proprietary Class 3 Page 5 of 46

Limitation and Condition Number 5 Summary The maximum assembly and rod length-average burnup is limited to [ ]a,c respectively. Compliance The maximum analyzed assembly and rod length-average burnup were less than or equal to [ ]a,c respectively, for Sequoyah Units 1 and 2.

Limitation and Condition Number 6 Summary The fuel performance data for analyses with the )6/2&$ EM should be based on the PAD5 code (at present), which includes the effect of thermal conductivity degradation. The nominal fuel pellet average temperatures and rod internal pressures should be the maximum values, and the generation of all the PAD5 fuel performance data should adhere to the NRC-approved PAD5 methodology. Compliance PAD5 fuel performance data were utilized in the Sequoyah Units 1 and 2 analysis with the )6/2&$ EM. The analyzed fuel pellet average temperatures bound the maximum values calculated in accordance with Section 7.5.1 of Reference 2, and the analyzed rod internal pressures were calculated in accordance with Section 7.5.2 of Reference 2.

Limitation and Condition Number 7 Summary The YDRAG uncertainty parameter should be [ ]a,c Compliance Consistent with the NRC-approved methodology, the YDRAG uncertainty parameter was [

]a,c for the Sequoyah Units 1 and 2 Region I analysis.

Limitation and Condition Number 8 Summary The [

]a,c Westinghouse Non-Proprietary Class 3 Page 6 of 46

Compliance Consistent with the NRC-approved methodology, the [

]a,c for the Sequoyah Units 1 and 2 Region I analysis.

Limitation and Condition Number 9 Summary For PWR designs which are not Westinghouse 3-loop PWRs, a sensitivity study will be executed to confirm that the [ ]a,c for the plant design being analyzed. This sensitivity study should be executed once, and then referenced in all applications to that particular plant class. Compliance Sequoyah Units 1 and 2 are Westinghouse-designed 4-loop PWRs. The requested sensitivity study was performed for a 4-loop Westinghouse-designed PWR and is discussed in Reference 11.

Limitation and Condition Number 10 Summary For PWR designs which are not Westinghouse 3-loop PWRs, a sensitivity study will be executed to: 1) demonstrate that no unexplained behavior occurs in the predicted safety criteria across the region boundary, and 2) ensure that the [ ]a,c must cover the equivalent 2 to 4-inch break range using RCS-volume scaling relative to the demonstration plant. This sensitivity study should be executed once, and then referenced in all applications to that particular plant class. Additionally, the minimum sampled break area for the analysis of Region II should be 1 ft2. Compliance Sequoyah Units 1 and 2 are Westinghouse-designed 4-loop PWRs. The requested sensitivity study was performed for a 4-loop Westinghouse-designed PWR and is discussed in Reference 11. The minimum sampled break area for the Sequoyah Units 1 and 2 Region II analysis was 1 ft2.

Limitation and Condition Number 11 Summary There are various aspects of this Limitation and Condition, which are summarized below: Westinghouse Non-Proprietary Class 3 Page 7 of 46

1. The [ ]a,c the Region I and Region II analysis seeds, and the analysis inputs will be declared and documented prior to performing the Region I and Region II uncertainty analyses. The [ ]a,c and the Region I and Region II analysis seeds will not be changed throughout the remainder of the analysis once they have been declared and documented. 2. If the analysis inputs are changed after they have been declared and documented, for the intended purpose of demonstrating compliance with the applicable acceptance criteria, then the changes and associated rationale for the changes will be provided in the analysis submittal. Additionally, the preliminary values for PCT, MLO, and CWO which caused the input changes will be provided. These preliminary values are not subject to Appendix B verification, and archival of the supporting information for these preliminary values is not required. 3. Plant operating ranges which are sampled within the uncertainty analysis will be provided in the analysis submittal for both regions. Compliance This Limitation and Condition was met for the Sequoyah Units 1 and 2 analysis as follows: 1. The [ ]a,c the Region I and Region II analysis seeds, and the analysis inputs were declared and documented prior to performing the Region I and Region II uncertainty analyses. The [ ]a,c and the Region I and Region II analysis seeds were not changed once they were declared and documented. 2. The analysis inputs were not changed once they were declared and documented. 3. The plant operating ranges which were sampled within the uncertainty analyses are provided for Sequoyah Units 1 and 2 in Table 1.

Limitation and Condition Number 12 Summary The plant-specific dynamic pressure loss from the steam generator secondary-side to the main steam safety valves (MSSVs) must be adequately accounted for in analysis with the )6/2&$ EM. Compliance A bounding plant-specific dynamic pressure loss from the steam generator secondary-side to the main steam safety valves was modeled in the Sequoyah Units 1 and 2 analysis.

Limitation and Condition Number 13 Summary In plant-specific models for analysis with the )6/2&$ EM: 1) the> ]a,c and 2) the [ ]a,c Westinghouse Non-Proprietary Class 3 Page 8 of 46

Compliance The [ ]a,c in the analysis for Sequoyah Units 1 and 2. The [ ]a,c in the analysis.

Limitation and Condition Number 14 Summary For analyses with the )6/2&$ EM to demonstrate compliance against the current 10 CFR 50.46 oxidation criterion, the transient time-at-temperature will be converted to an equivalent cladding reacted (ECR) using either the Baker-Just or the Cathcart-Pawel correlation. In either case, the pre-transient corrosion will be summed with the LOCA transient oxidation. If the Cathcart-Pawel correlation is used to calculate the LOCA transient ECR, then the result shall be compared to a 13 percent limit. If the Baker- Just correlation is used to calculate the LOCA transient ECR, then the result shall be compared to a 17 percent limit. Compliance For the Sequoyah Units 1 and 2 analysis, the Baker-Just correlation was used to convert the LOCA transient time-at-temperature to an ECR. The resulting LOCA transient ECR was then summed with the pre-existing corrosion for comparison against the 10 CFR 50.46 local oxidation acceptance criterion of 17%.

Limitation and Condition Number 15 Summary The Region II analysis will be executed twice; once assuming loss-of-offsite power (LOOP) and once assuming offsite power available (OPA). The results from both analysis executions should be shown to be in compliance with the 10 CFR 50.46 acceptance criteria. The [ ]a,c Compliance The Region II uncertainty analysis for Sequoyah Units 1 and 2 was performed twice; once assuming a LOOP and once assuming OPA. The results from both analyses that were performed are in compliance with the 10 CFR 50.46 acceptance criteria (see Section 5.0). The [ ]a,c Westinghouse Non-Proprietary Class 3 Page 9 of 46

3.0 REGION I ANALYSIS

3.1 Description of Representative Transient

The small break LOCA transient can be divided into time periods in which specific phenomena are occurring, as discussed below. Blowdown The rapid depressurization of the RCS coincides with subcooled liquid flow through the break. Following the reactor trip on the low pressurizer pressure setpoint, the pressurizer drains, and safety injection is initiated on the low pressurizer pressure SI setpoint. After reaching this setpoint and applying the safety injection delays, high pressure safety injection flow begins. Phase separation begins in the upper head and upper plenum near the end of this period until the entire RCS eventually reaches saturation, ending the rapid depressurization slightly above the steam generator secondary side pressure near the modeled MSSV setpoint. Natural Circulation This quasi-equilibrium phase persists while the RCS pressure remains slightly above the secondary side pressure. The system drains from the top down, and while significant mass is continually lost through the break, the vapor generated in the core is trapped in the upper regions by the liquid remaining in the crossover leg loop seals. Throughout this period, the core remains covered by a two-phase mixture and the fuel cladding temperatures remain at the saturation temperature level. Loop Seal Clearance As the system drains, the liquid levels in the downhill side of the pump suction (crossover leg) become depressed all the way to the bottom elevations of the piping, allowing the steam trapped during the natural circulation phase to vent to the break (i.e., a process called loop seal clearance). The break flow and the flow through the RCS loops become primarily vapor. Relief of a static head imbalance allows for a quick but temporary recovery of liquid levels in the inner portion of the reactor vessel. Boil-Off With a vapor vent path established after the loop seal clearance, the RCS depressurizes at a rate controlled by the critical flow, which continues to be a primarily high quality mixture of water and steam. The RCS pressure remains high enough such that safety injection flow cannot make up for the primary system fluid inventory lost through the break, leading to core uncovery and a fuel rod cladding temperature heatup. Core Recovery The RCS pressure continues to decrease, and once it reaches that of the accumulator gas pressure, the introduction of additional ECCS water from the accumulators replenishes the reactor vessel inventory and recovers the core mixture level. The transient is considered over as the break flow is compensated by the injected flow.

3.2 Analysis Results

The Sequoyah Units 1 and 2 Region I analysis was performed in accordance with the NRC-approved methodology in Reference 1 with exceptions identified under Limitation and Condition Number 2 in Section 2.3. The transient that produced the analysis PCT result is a cold leg break with a break diameter Westinghouse Non-Proprietary Class 3 Page 10 of 46

of 2.4-inches. The most limiting ECCS single failure of one ECCS train is assumed in the analysis as identified in Table 1. Control rod drop is modeled for breaks less than 1 square foot assuming a 2 second pressurizer pressure reactor trip signal delay time and a 3 second rod drop time. RCP trip is modeled coincident with reactor trip on the low pressurizer pressure setpoint for LOOP transients. When the low pressurizer pressure SI setpoint is reached, there is a delay to account for emergency diesel generator start-up, filling headers, etc., after which safety injection is initiated into the reactor coolant system. The results of the Sequoyah Units 1 and 2 Region I uncertainty analysis are summarized in Table 4. The sampled decay heat uncertainty multipliers for the Region I analysis cases are provided in Table 7. Table 5 contains a sequence of events for the transient that produced the Region I analysis PCT result. Figures 1 through 11 illustrate the calculated key transient response parameters for this transient.

4.0 REGION II ANALYSIS

4.1 Description of Representative Transient

A large-break LOCA transient can be divided into phases in which specific phenomena are occurring. A convenient way to divide the transient is in terms of the various heatup and cooldown phases that the fuel assemblies undergo. For each of these phases, specific phenomena and heat transfer regimes are important, as discussed below. Blowdown – Critical Heat Flux (CHF) Phase In this phase, the break flow is subcooled, the discharge rate of coolant from the break is high, the core flow reverses, the fuel rods go through departure from nucleate boiling (DNB), and the cladding rapidly heats up and the reactor is shut down due to the core voiding. The regions of the RCS with the highest initial temperatures (upper core, upper plenum, and hot legs) begin to flash during this period. This phase is terminated when the water in the lower plenum and downcomer begins to flash. The mixture level swells and a saturated mixture is pushed into the core by the intact loop RCPs, still rotating in single-phase liquid. As the fluid in the cold leg reaches saturation conditions, the discharge flow rate at the break decreases significantly. Blowdown – Upward Core Flow Phase Heat transfer is increased as the two-phase mixture is pushed into the core. The break discharge rate is reduced because the fluid becomes saturated at the break. This phase ends as the lower plenum mass is depleted, the fluid in the loops become two-phase, and the RCP head degrades. Blowdown – Downward Core Flow Phase The break flow begins to dominate and pulls flow down through the core as the RCP head degrades due to increased voiding, while liquid and entrained liquid flows also provide core cooling. Heat transfer in this period may be enhanced by liquid flow from the upper head. Once the system has depressurized to less than the accumulator cover pressure, the accumulators begin to inject cold water into the cold legs. During this period, due to steam upflow in the downcomer, a portion of the injected ECCS water is bypassed around the downcomer and sent out through the break. As the system pressure continues to decrease, the break flow and consequently the downward core flow are reduced. The system pressure approaches the containment pressure at the end of this last period of the blowdown phase. Westinghouse Non-Proprietary Class 3 Page 11 of 46

During this phase, the core begins to heat up as the system approaches containment pressure, and the phase ends when the reactor vessel begins to refill with ECCS water. Refill Phase The core continues to heat up as the lower plenum refills with ECCS water. This phase is characterized by a rapid increase in fuel cladding temperature at all elevations due to the lack of liquid and steam flow in the core region. The water completely refills the lower plenum and the refill phase ends. As ECCS water enters the core, the fuel rods in the lower core region begin to quench and liquid entrainment begins, resulting in increased fuel rod heat transfer. Reflood Phase During the early reflood phase, the accumulators begin to empty and nitrogen is discharged into the RCS. The nitrogen surge forces water into the core, which is then evaporated, causing system re-pressurization and a temporary reduction of pumped ECCS flow; this re-pressurization is illustrated by the increase in RCS pressure. During this time, core cooling may increase due to vapor generation and liquid entrainment, but conversely the early reflood pressure spike results in loss of mass out through the broken cold leg. The pumped ECCS water aids in the filling of the downcomer throughout the reflood period. As the quench front progresses further into the core, the PCT elevation moves increasingly higher in the fuel assembly. As the transient progresses, continued injection of pumped ECCS water refloods the core, effectively removes the reactor vessel metal mass stored energy and core decay heat, and leads to an increase in the reactor vessel fluid mass. Eventually the core inventory increases enough that liquid entrainment is able to quench all the fuel assemblies in the core.

4.2 Analysis Results

The Sequoyah Units 1 and 2 Region II analysis was performed in accordance with the NRC-approved methodology in Reference 1 with exceptions identified under Limitation and Condition Number 2 in Section 2.3. The analysis was performed assuming both LOOP and OPA, and the results of both of the LOOP and OPA analyses are compared to the 10 CFR 50.46 acceptance criteria. The most limiting ECCS single failure of one ECCS train is assumed in the analysis as identified in Table 1. The results of the Sequoyah Units 1 and 2 Region II LOOP and OPA uncertainty analyses are summarized in Table 4. The sampled decay heat uncertainty multipliers for the Region II analysis cases are provided in Table 7. Table 6 contains a sequence of events for the LOOP transient that produced the more limiting analysis PCT result relative to the offsite power assumption. Figures 12 through 25 illustrate the key response parameters for this transient. The containment pressure is calculated using the LOTIC2 code (References 9 and 10) for ice condenser containments. The assumed, conservatively low containment pressure response used for the Sequoyah Units 1 and 2 Region II analysis is compared to the calculated containment backpressure in Figure 19, consistent with the methodology in Reference 1. Westinghouse Non-Proprietary Class 3 Page 12 of 46

5.0 COMPLIANCE WITH 10 CFR 50.46

It must be demonstrated that there is a high level of probability that the following criteria in 10 CFR 50.46 are met: (b)(1) The analysis PCT corresponds to a bounding estimate of the 95th percentile PCT at the 95- percent confidence level. Since the resulting PCT is less than 2,200°F, the analysis with the )6/2&$ EM confirms that 10 CFR 50.46 acceptance criterion (b)(1), i.e., “Peak Cladding Temperature does not exceed 2,200°F,” is demonstrated. The results are shown in Table 4 for Sequoyah Units 1 and 2. (b)(2) The analysis MLO corresponds to a bounding estimate of the 95th percentile MLO at the 95- percent confidence level. Since the resulting MLO is less than 17 percent when converting the time-at-temperature to an equivalent cladding reacted using the Baker-Just correlation and adding the pre-transient corrosion, the analysis confirms that 10 CFR 50.46 acceptance criterion (b)(2), i.e., “Maximum Local Oxidation of the cladding does not exceed 17 percent,” is demonstrated. The results are shown in Table 4 for Sequoyah Units 1 and 2. (b)(3) The analysis CWO corresponds to a bounding estimate of the 95th percentile CWO at the 95- percent confidence level. Since the resulting CWO is less than 1 percent, the analysis confirms that 10 CFR 50.46 acceptance criterion (b)(3), i.e., “Core-Wide Oxidation does not exceed 1 percent,” is demonstrated. The results are shown in Table 4 for Sequoyah Units 1 and 2. (b)(4) 10 CFR 50.46 acceptance criterion (b)(4) requires that the calculated changes in core geometry are such that the core remains in a coolable geometry. This criterion is met by demonstrating compliance with criteria (b)(1), (b)(2), and (b)(3), and by assuring that fuel assembly grid deformation due to combined LOCA and seismic loads is specifically addressed. Criteria (b)(1), (b)(2), and (b)(3) have been met for Sequoyah Units 1 and 2 as shown in Table 4. It is discussed in Section 32.1 of the NRC-approved )6/2&$ EM (Reference 1) that the effects of LOCA and seismic loads on the core geometry do not need to be considered unless fuel assembly grid deformation extends beyond the core periphery (i.e., deformation in a fuel assembly with no sides adjacent to the core baffle plates). Inboard grid deformation due to combined LOCA and seismic loads is not calculated to occur for Sequoyah Units 1 and 2. (b)(5) 10 CFR 50.46 acceptance criterion (b)(5) requires that long-term core cooling be provided following the successful initial operation of the ECCS. Long-term cooling is dependent on the demonstration of the continued delivery of cooling water to the core. The actions that are currently in place to maintain long-term cooling are not impacted by the application of the NRC-approved )6/2&$ EM (Reference 1). Based on the analysis results for Region I and Region II presented in Table 4 for Sequoyah Units 1 and 2, it is concluded that Sequoyah Units 1 and 2 comply with the criteria in 10 CFR 50.46. Westinghouse Non-Proprietary Class 3 Page 13 of 46

6.0 ASSESSMENT OF TRANSITION CORE EFFECTS ON RESIDENT FUEL

The Sequoyah Units 1 and 2 analysis with the )6/2&$ EM was performed assuming a full core of Westinghouse RFA-2 fuel. For the initial cycles in which Westinghouse RFA-2 fuel is used, however, Framatome HTP fuel will also be present. While the two fuel designs have generally similar mechanical designs, a transition core evaluation was performed to address the mixed core effects for both fuel types.

The loss coefficient of the Westinghouse RFA-2 fuel is slightly lower than the Framatome HTP fuel, and thus the analysis with the )6/2&$ EM assuming a homogeneous core of RFA-2 fuel is bounding of the mixed core effect for Westinghouse fuel, since the RFA-2 fuel would receive a flow benefit in the presence of the relatively starved HTP fuel.

An evaluation was therefore performed to assess the PCT effect of the RFA-2 on the Framatome HTP fuel within the context of the existing analysis of record supporting operation with that fuel type.

For SBLOCA transients, core-wide collapsed liquid levels correspond closely to a 1-dimensional flow pattern, and the effects of grid loss coefficient differences among the assemblies are not significant in determining the PCT. As such, the existing analysis of record supporting operation with Framatome HTP fuel is applicable for the Framatome HTP fuel during the transition cycle(s) to Westinghouse RFA-2 fuel.

For LBLOCA transients, conditions during blowdown and reflood can be affected by mixed core conditions arising from a hydraulic mismatch. The existing analysis of record performed with the best- estimate AREVA/Framatome RLBLOCA methodology resulted in a PCT occurring around 265 seconds after the postulated break during the reflood period. The PCT increase for Framatome HTP fuel resulting from the hydraulic mismatch was estimated to be 23 °F, based on the expected effects on a transient with the reflood time and cladding heatup rate consistent with the Sequoyah Units 1 and 2 RLBLOCA analysis. The PCT estimate of effect of 23 °F is applicable for the Framatome HTP fuel during transition cycles to Westinghouse RFA-2 fuel.

7.0 REFERENCES

1. “Realistic LOCA Evaluation Methodology Applied to the Full Spectrum of Break Sizes (FULL SPECTRUM LOCA Methodology),” WCAP-16996-P-A, Revision 1, November 2016. 2. “Westinghouse Performance Analysis and Design Model (PAD5),” WCAP-17642-P-A, Revision 1, November 2017. 3. “Acceptance Criteria for Emergency Core Cooling Systems for Light Water Cooled Nuclear Power Reactors,” 10 CFR 50.46 and Appendix K of 10 CFR 50, Federal Register, Volume 39, Number 3, January 1974. 4. “Information Notice 98-29: Predicted Increase in Fuel Rod Cladding Oxidation,” USNRC, August 1998. 5. “U.S. Nuclear Regulatory Commission 10 CFR 50.46 Annual Notification and Reporting for 2017,” LTR-NRC-18-30, July 2018. 6. “Emergency Core Cooling Systems: Revisions to Acceptance Criteria,” Federal Register, V53, N180, pp. 35996-36005, September 1988. Westinghouse Non-Proprietary Class 3 Page 14 of 46

7. “Best Estimate Calculations of Emergency Core Cooling System Performance,” Regulatory Guide 1.157, USNRC, May 1989. 8. “Transient and Accident Analysis Methods,” Regulatory Guide 1.203, USNRC, December 2005. 9. “Westinghouse Emergency Core Cooling System Evaluation Model – Summary,” WCAP-8339, June 1974. 10. “Long Term Ice Condenser Containment Code – LOTIC Code,” WCAP-8354-P-A, Supplement 1, April 1976. 11. “‘Information to Satisfy the FULL SPECTRUM LOCA (FSLOCA) Evaluation Methodology Plant Type Limitations and Conditions for 4-loop Westinghouse Pressurized Water Reactors (PWRs)’ (Proprietary/Non-Proprietary),” LTR-NRC-18-50, July 2018. Westinghouse Non-Proprietary Class 3 Page 15 of 46

Table 1. Plant Operating Range Analyzed and Key Parameters for Sequoyah Units 1 and 2 Parameter As-Analyzed Value or Range 1.0 Core Parameters a) Core power ”0 MWt r 0% Uncertainty b) Fuel type 17x17 RFA-2, 2SWLPL]HG=,5/2™ High Performance Cladding Material, non- IFBA or IFBA with IFMs

c) Maximum total core peaking factor (FQ), 2.65 including uncertainties d) Maximum hot channel enthalpy rise peaking 1.7 factor (F¨+), including uncertainties e) Axial flux difference (AFD) band at 100% -13% / +7% power f) Maximum transient operation fraction 0.25 2.0 Reactor Coolant System Parameters a) Thermal design flow (TDF) 90,000 gpm/loop

b) Vessel average temperature (TAVG)570.7ƒ)”7AVG ”85.7°F

c) Pressurizer pressure (PRCS) 2200 SVLD”3RCS ”00 psia d) Reactor coolant pump (RCP) model and power Model 93ACS, 6000 hp 3.0 Containment Parameters a) Containment modeling Region I: Constant pressure equal to initial containment pressure Region II: Conservatively low containment pressure (Figure 19) 4.0 Steam Generator (SG) and Secondary Side Parameters a) Steam generator tube plugging level ” b) Main feedwater temperature Nominal (435.7°F) c) Auxiliary feedwater temperature Nominal (80°F) d) Auxiliary feedwater flow rate 200 gpm/SG 5.0 Safety Injection (SI) Parameters a) Single failure configuration ECCS: Loss of one train of pumped ECCS Region II containment pressure: All containment spray trains are available

b) Safety injection temperature (TSI)55ƒ)”7SI ”10°F

Optimized ZIRLO is a trademark of Westinghouse Electric Company LLC, its affiliates and/or its subsidiaries in the United States of America and may be registered in other countries throughout the world. All rights reserved. Unauthorized use is strictly prohibited. Other names may be trademarks of their respective owners. Westinghouse Non-Proprietary Class 3 Page 16 of 46

Table 1. Plant Operating Range Analyzed and Key Parameters for Sequoyah Units 1 and 2 Parameter As-Analyzed Value or Range c) Low pressurizer pressure safety injection safety 1700 psia analysis limit d) Initiation delay time from low pressurizer ”40 seconds (OPA) or ” 55 seconds pressure SI setpoint to full SI flow (LOOP) e) Safety injection flow Minimum flows in Table 2 (Region I) or Table 3 (Region II) 6.0 Accumulator Parameters

a) Accumulator temperature (TACC) ƒ)”7ACC ”ƒ)

3 3 b) Accumulator water volume (VACC) 1005 ft ”9ACC ”IW

c) Accumulator pressure (PACC)610 psia ”3ACC ”700 psia d) Accumulator boron concentration •2350 ppm 7.0 Reactor Protection System Parameters a) Low pressurizer pressure reactor trip signal ”2 seconds processing time b) Low pressurizer pressure reactor trip setpoint 1859 psia 8.0 Refueling Water Storage Tank (RWST) / Switchover Parameters a) Usable RWST volume •231,000 gallons b) Interruption time for switchover to cold leg 0 seconds recirculation Westinghouse Non-Proprietary Class 3 Page 17 of 46

Table 2. Safety Injection Flow Used for Region I Calculation for Sequoyah Units 1 and 2 High Head Safety Injection Intermediate Head Safety Pressure (psia) (HHSI) Flow (gpm) Injection (IHSI) Flow (gpm) 14.7 260.0 398.1 114.7 251.0 381.9 214.7 242.0 365.7 314.7 233.0 348.3 414.7 216.0 330.6 514.7 189.0 312.6 614.7 162.0 294.0 714.7 135.0 272.7 814.7 111.0 250.1 914.7 84.0 225.0 1014.7 54.0 196.1 1114.7 26.0 160.8 1214.7 0.0 116.7 1314.7 0.0 53.4 1414.7 0.0 0.0 Westinghouse Non-Proprietary Class 3 Page 18 of 46

Table 3. Safety Injection Flow Used for Region II Calculation for Sequoyah Units 1 and 2 High Head Safety Intermediate Head Safety Low Head Safety Injection Pressure (psia) Injection (HHSI) Flow Injection (IHSI) Flow (LHSI) Flow (gpm) (gpm) (gpm) 14.7 260.0 398.1 2856.3 34.7 258.2 394.1 2223.7 54.7 256.4 390.2 1577.2 74.7 254.6 386.2 1286.0 94.7 252.8 382.3 955.0 114.7 251.0 378.3 556.0 134.7 249.2 374.3 1.5 154.7 247.4 370.3 0.0 214.7 242.0 358.2 0.0 314.7 233.0 336.6 0.0 414.7 216.0 314.1 0.0 514.7 189.0 290.7 0.0 614.7 162.0 266.4 0.0 714.7 135.0 240.6 0.0 814.7 111.0 206.3 0.0 914.7 84.0 165.2 0.0 1014.7 54.0 115.7 0.0 1114.7 26.0 55.7 0.0 1214.7 0.0 0.0 0.0 Westinghouse Non-Proprietary Class 3 Page 19 of 46

Table 4. Sequoyah Units 1 and 2 Analysis Results with the FSLOCA EM Region II Value Region II Value Outcome Region I Value (OPA) (LOOP) 95/95 PCT 1,213°F 1,878°F 1,878°F 95/95 MLO 6.4% 8.0% 8.5% 95/95 CWO 0.0% 0.5% 0.4%

Table 5. Sequoyah Units 1 and 2 Sequence of Events for Region I Analysis PCT Transient Event Time after Break (sec) Start of Transient 0.0 Reactor Trip Signal 28.8 Safety Injection Signal 46.3 Safety Injection Begins 101 Top of Core Uncovered 2,214 PCT Occurs 3,182 Top of Core Recovered 4,796

Table 6. Sequoyah Units 1 and 2 Sequence of Events for Region II Analysis PCT Transient Event Time after Break (sec) Start of Transient 0.0 Burst Occurs 1.6 Safety Injection Signal 5.5 Accumulator Injection Begins 12.0 End of Blowdown 21.5 Safety Injection Begins 60.5 Accumulator Empty 109 PCT Occurs 276 All Rods Quenched 500 Westinghouse Non-Proprietary Class 3 Page 20 of 46

Table 7. Sequoyah Units 1 and 2 Sampled Value of Decay Heat Uncertainty Multiplier, DECAY_HT, for Region I and Region II Analysis Cases Region Case '(&$

Figure 1: Sequoyah Units 1 and 2 Break Flow Void Fraction for the Region I Analysis PCT Case Westinghouse Non-Proprietary Class 3 Page 22 of 46

Figure 2: Sequoyah Units 1 and 2 Total Pumped SI Flow and Total Break Flow for the Region I Analysis PCT Case Westinghouse Non-Proprietary Class 3 Page 23 of 46

Figure 3: Sequoyah Units 1 and 2 RCS Pressure for the Region I Analysis PCT Case Westinghouse Non-Proprietary Class 3 Page 24 of 46

Figure 4: Sequoyah Units 1 and 2 Hot Assembly Two-Phase Mixture Level (where 0 ft is bottom of active fuel, 12 ft is top of active fuel) for the Region I Analysis PCT Case Westinghouse Non-Proprietary Class 3 Page 25 of 46

Figure 5: Sequoyah Units 1 and 2 Peak Cladding Temperature for all Rods for the Region I Analysis PCT Case Westinghouse Non-Proprietary Class 3 Page 26 of 46

Figure 6: Sequoyah Units 1 and 2 Collapsed Liquid Level for Each Core Channel (where 0 ft is bottom of active fuel, 12 ft is top of active fuel) for the Region I Analysis PCT Case Westinghouse Non-Proprietary Class 3 Page 27 of 46

Figure 7: Sequoyah Units 1 and 2 Vessel Fluid Mass for the Region I Analysis PCT Case Westinghouse Non-Proprietary Class 3 Page 28 of 46

Figure 8: Sequoyah Units 1 and 2 Steam Generator Secondary Side Pressure for the Region I Analysis PCT Case Westinghouse Non-Proprietary Class 3 Page 29 of 46

Figure 9: Sequoyah Units 1 and 2 Normalized Core Power Shapes for the Region I Analysis PCT Case

Note: The localized power decreases occur at grid elevations. Westinghouse Non-Proprietary Class 3 Page 30 of 46

Figure 10: Sequoyah Units 1 and 2 Relative Core Power for the Region I Analysis PCT Case Westinghouse Non-Proprietary Class 3 Page 31 of 46

Figure 11: Sequoyah Units 1 and 2 Vapor Temperature and Void Fraction at Core Outlet for the Region I Analysis PCT Case Westinghouse Non-Proprietary Class 3 Page 32 of 46

Figure 12: Sequoyah Units 1 and 2 Peak Cladding Temperature for all Rods for the Region II Analysis PCT Case Westinghouse Non-Proprietary Class 3 Page 33 of 46

Figure 13: Sequoyah Units 1 and 2 Peak Cladding Temperature Elevation (where 0 ft is bottom of active fuel, 12 ft is top of active fuel) for the Region II Analysis PCT Case Westinghouse Non-Proprietary Class 3 Page 34 of 46

Figure 14a: Sequoyah Units 1 and 2 Vessel-Side Break Mass Flow Rate for the Region II Analysis PCT Case Westinghouse Non-Proprietary Class 3 Page 35 of 46

Figure 14b: Sequoyah Units 1 and 2 Pump-Side Break Mass Flow Rate for the Region II Analysis PCT Case Westinghouse Non-Proprietary Class 3 Page 36 of 46

Figure 15: Sequoyah Units 1 and 2 Lower Plenum Collapsed Liquid Level (where 0 ft is the inside bottom of the reactor vessel) for the Region II Analysis PCT Case Westinghouse Non-Proprietary Class 3 Page 37 of 46

Figure 16: Sequoyah Units 1 and 2 Vapor Mass Flow Rate per Assembly at the Top Cell Face of the Core Average Channel Not Under Guide Tubes for the Region II Analysis PCT Case Westinghouse Non-Proprietary Class 3 Page 38 of 46

Figure 17: Sequoyah Units 1 and 2 RCS Pressure for the Region II Analysis PCT Case Westinghouse Non-Proprietary Class 3 Page 39 of 46

Figure 18: Sequoyah Units 1 and 2 Accumulator Injection Flow per Loop for the Region II Analysis PCT Case Westinghouse Non-Proprietary Class 3 Page 40 of 46

Figure 19: Sequoyah Units 1 and 2 Containment Pressure for the Region II Analysis PCT Case Westinghouse Non-Proprietary Class 3 Page 41 of 46

Figure 20: Sequoyah Units 1 and 2 Vessel Fluid Mass for the Region II Analysis PCT Case Westinghouse Non-Proprietary Class 3 Page 42 of 46

Figure 21: Sequoyah Units 1 and 2 Collapsed Liquid Level for Each Core Channel (where 0 ft is bottom of active fuel, 12 ft is top of active fuel) for the Region II Analysis PCT Case Westinghouse Non-Proprietary Class 3 Page 43 of 46

Figure 22: Sequoyah Units 1 and 2 Average Downcomer Collapsed Liquid Level (where 0 ft is the inside bottom of the reactor vessel) for the Region II Analysis PCT Case Westinghouse Non-Proprietary Class 3 Page 44 of 46

Figure 23: Sequoyah Units 1 and 2 Total Pumped SI Flow Rate per Loop (not including Accumulator Flow) for the Region II Analysis PCT Case Westinghouse Non-Proprietary Class 3 Page 45 of 46

Figure 24: Sequoyah Units 1 and 2 Normalized Core Power Shapes for the Region II Analysis PCT Case

Note: The localized power decreases occur at grid elevations. Westinghouse Non-Proprietary Class 3 Page 46 of 46

Figure 25: Sequoyah Units 1 and 2 Relative Core Power for the Region II Analysis PCT Case Enclosure 4

Affidavit

CNL-20-014 Westinghouse Non-Proprietary Class 3 CAW-20-5063 Page 1 of 3 AFFIDAVIT

COMMONWEALTH OF PENNSYLVANIA: COUNTY OF BUTLER:

(1) I, Korey L. Hosack, have been specifically delegated and authorized to apply for withholding and execute this Affidavit on behalf of Westinghouse Electric Company LLC (Westinghouse).

(2) I am requesting the proprietary portions of CNL-20-014, “Application to Revise Sequoyah Nuclear Plant Units 1 and 2 Technical Specifications to Allow for Transition to Westinghouse RFA-2 Fuel (SQN-TS-20-09)” Enclosure 2 be withheld from public disclosure under 10 CFR 2.390.

(3) I have personal knowledge of the criteria and procedures utilized by Westinghouse in designating information as a trade secret, privileged, or as confidential commercial or financial information.

(4) Pursuant to 10 CFR 2.390, the following is furnished for consideration by the Commission in determining whether the information sought to be withheld from public disclosure should be withheld.

(i) The information sought to be withheld from public disclosure is owned and has been held in confidence by Westinghouse and is not customarily disclosed to the public.

(ii) Public disclosure of this proprietary information is likely to cause substantial harm to the competitive position of Westinghouse because it would enhance the ability of competitors to provide similar technical evaluation justifications and licensing defense services for commercial power reactors without commensurate expenses. Also, public disclosure of the information would enable others to use the information to meet NRC requirements for licensing documentation without purchasing the right to use the information.

Westinghouse Non-Proprietary Class 3 CAW-20-5063 Page 2 of 3 AFFIDAVIT

(5) Westinghouse has policies in place to identify proprietary information. Under that system, information is held in confidence if it falls in one or more of several types, the release of which might result in the loss of an existing or potential competitive advantage, as follows:

(a) The information reveals the distinguishing aspects of a process (or component, structure, tool, method, etc.) where prevention of its use by any of Westinghouse's competitors without license from Westinghouse constitutes a competitive economic advantage over other companies.

(b) It consists of supporting data, including test data, relative to a process (or component, structure, tool, method, etc.), the application of which data secures a competitive economic advantage (e.g., by optimization or improved marketability).

(c) Its use by a competitor would reduce his expenditure of resources or improve his competitive position in the design, manufacture, shipment, installation, assurance of quality, or licensing a similar product.

(d) It reveals cost or price information, production capacities, budget levels, or commercial strategies of Westinghouse, its customers or suppliers.

(e) It reveals aspects of past, present, or future Westinghouse or customer funded development plans and programs of potential commercial value to Westinghouse.

(f) It contains patentable ideas, for which patent protection may be desirable.

(6) The attached documents are bracketed and marked to indicate the bases for withholding. The justification for withholding is indicated in both versions by means of lower case letters (a) through (f) located as a superscript immediately following the brackets enclosing each item of information being identified as proprietary or in the margin opposite such information. These Westinghouse Non-Proprietary Class 3 CAW-20-5063 Page 3 of 3 AFFIDAVIT

lower case letters refer to the types of information Westinghouse customarily holds in confidence identified in Sections (5)(a) through (f) of this Affidavit.

I declare that the averments of fact set forth in this Affidavit are true and correct to the best of my knowledge, information, and belief.

I declare under penalty of perjury that the foregoing is true and correct.

Executed on: ______2020 07 01 ______Korey L. HkHosack, Manager Licensing, Analysis, & Testing Enclosure 5

Exemption Request

CNL-20-014 Sequoyah Nuclear Plant License Amendment Request

REQUEST FOR PERMANENT EXEMPTION 10 CFR 50.46 AND 10 CFR PART 50 APPENDIX K FOR OPTIMIZED ZIRLO™

The proposed license amendment request will revise the Sequoyah Units 1 and 2 Renewed Facility Operating Licenses to allow the use of Optimized ZIRLOTM fuel rod cladding material. Acceptable fuel rod cladding material is identified in Sequoyah Technical Specification (TS) Section 4.2.1, Fuel Assemblies, as either Zircaloy or M5 (the latter is a Framatome product). The proposed change will add Optimized ZIRLO fuel rod cladding material as an acceptable material. As discussed in Section 4.1.3 of the license amendment request, with respect to Limitation and Conditions #1 and #4 in the NRC Safety Evaluation for the Optimized ZIRLO topical report (Reference 1) and the Conclusions in the second NRC Safety Evaluation for WCAP-12610-P-A (Reference 2, which discusses the change from Zircaloy to ZIRLO® cladding), a permanent exemption from certain requirements of 10 CFR 50.46, Acceptance Criteria for Emergency Core Cooling Systems for Light-Water Nuclear Power Reactors, and 10 CFR 50 Appendix K, ECCS Evaluation Models, is required to support this change.

Part 50.46(a)(l)(i) of Title 10 of the Code of Federal Regulations (10 CFR 50.46(a)(l)(i)) states in part:

"Each boiling or pressurized light-water nuclear power reactor fueled with uranium oxide pellets within cylindrical Zircaloy or ZIRLO cladding must be provided with an emergency core cooling system (ECCS) that must be designed so that its calculated cooling performance following postulated loss-of-coolant accidents conforms to the criteria set forth in paragraph (b) of this section. ECCS cooling performance must be calculated in accordance with an acceptable evaluation model and must be calculated for a number of postulated loss-of-coolant accidents of different sizes, locations, and other properties sufficient to provide assurance that the most severe postulated loss-of-coolant accidents are calculated."

10 CFR 50.46 continues with a delineation of specifications for peak cladding temperature, maximum hydrogen generation, coolable geometry, and long-term cooling. Since 10 CFR 50.46 specifically refers to fuel with Zircaloy or ZIRLO® cladding and does not list Optimized ZIRLO cladding, the use of Optimized ZIRLO cladding requires a permanent exemption from this section of the regulations.

10 CFR 50, Appendix K, paragraph I.A.5, states in part:

"The rate of energy release, hydrogen generation, and cladding oxidation from the metal/water reaction shall be calculated using the Baker-Just equation."

The Baker-Just equation presumes the use of Zircaloy or ZIRLO® cladding. The routine use of Optimized ZIRLO cladding requires a permanent exemption from this section of the regulations.

Pursuant to 10 CFR 50.12, Specific Exemptions, TVA is requesting a permanent exemption from the requirements of 10 CFR 50.46, Acceptance Criteria for Emergency Core Cooling Systems for Light-Water Nuclear Power Reactors, and 10 CFR 50, Appendix K, ECCS Evaluation Models, for Sequoyah Units 1 and 2.

E5-1 of 5 Sequoyah Nuclear Plant License Amendment Request

The permanent exemption will allow the use of fuel assemblies manufactured by Westinghouse with Optimized ZIRLO alloy clad fuel rods, consistent with NRC-approved Westinghouse design and analysis methodologies.

As of year-end 2015, Optimized ZIRLO clad fuel had operated in over 41 plants. Full reloads of Optimized ZIRLO clad fuel are currently operating in 27 units worldwide. At the end of 2015, nine units had full cores. Over 4900 assemblies have been delivered with Optimized ZIRLO representing over 1,178,000 fuel rods in operation or discharged.

Background

As the nuclear industry pursues longer operating cycles with increased fuel discharge burnup and fuel duty, in conjunction with the NRC's proposed changes to 10 CFR 50.46, the corrosion performance requirements for the nuclear fuel cladding have become more demanding. Optimized ZIRLO material was developed to meet these needs and provides 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. Optimized ZIRLO provides enhanced corrosion resistance in more adverse in-reactor primary chemistry environments and at higher fuel duties with higher burnups. TVA currently plans to use Optimized ZIRLO fuel rod cladding for Sequoyah reloads starting with new RFA-2 fuel introduced for Sequoyah, Unit 1 Cycle 26.

Zircaloy-4 alloy is different from ZIRLO® by virtue of ZIRLO® having reduced tin and iron content, elimination of the chromium content, and the addition of 1% niobium. Optimized ZIRLO fuel cladding is different from ZIRLO® in two respects: 1) the tin content is lower; and 2) the microstructure is different. This difference in tin content and microstructure can lead to differences in some material properties. Most of the material properties of Zircaloy and Optimized ZIRLO are the same within the uncertainty of the data and therefore use of Zircaloy properties for safety analyses is acceptable. However, the NRC Safety Evaluation for Optimized ZIRLO suggests that the computer codes used to perform fuel design safety analyses incorporate the material properties of Optimized ZIRLO. This has been done for Sequoyah, Units 1 and 2.

Technical Justification of Acceptability

Optimized ZIRLO is described in topical report WCAP-12610-P-A & CENPD-404-P-A, Addendum 1-A, which has been reviewed and approved by the NRC (Reference 1). The NRC staff approved Optimized ZIRLO fuel cladding based on: 1) similarities with standard ZIRLO®, 2) demonstrated material performance; and 3) a commitment to provide irradiated data and validated fuel performance models ahead of burnups achieved in batch application. The NRC Safety Evaluation for Reference 1 included several Limitations and Conditions which are addressed in Attachment 8 to Enclosure 1 of the license amendment request.

E5-2 of 5 Sequoyah Nuclear Plant License Amendment Request

The core reload evaluations will ensure that acceptance criteria are met for the insertion of assemblies with fuel rods clad with Optimized ZIRLO. These assemblies will be evaluated using NRC-approved methods and models to address the use of Optimized ZIRLO.

Justification of Exemption

The standards set forth in 10 CFR 50.12 provide that the Commission may grant exemptions from the requirements of the regulations for reasons consistent with the following:

• The exemption is authorized by law; • The exemption will not present an undue risk to the public health and safety; • The exemption is consistent with the common defense and security; and • Special circumstances are present.

This 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. Further, it should be noted that, by submitting this exemption request, TVA does not seek an exemption from the acceptance and analytical criteria of 10 CFR 50.46 and 10 CFR Part 50, Appendix K. The intent of the request is solely to allow the use of Optimized ZIRLO as the fuel rod cladding material in lieu of Zircaloy or M5 cladding. Therefore, as required by 10 CFR 50.12 (a)(1), this requested exemption is "authorized by law."

The exemption will not present an undue risk to public health and safety. The NRC staff approved Westinghouse topical report WCAP-12610-P-A & CENPD-404-P-A, Addendum 1-A (Reference 1).

The Optimized ZIRLO topical report demonstrates that predicted chemical, mechanical, and material performance characteristics of the Optimized ZIRLO alloy cladding are within those approved for Zircaloy under anticipated operational occurrences and postulated accidents. Topical report WCAP-12610-P-A & CENPD-404-P-A, Addendum 1-A, demonstrates that Optimized ZIRLO has essentially the same properties as the currently licensed Zircaloy cladding in Sequoyah Technical Specification 4.2.1. The safety analysis for Sequoyah Units 1 and 2 is supported by site-specific TS. Reload cores are required to be operated in accordance with the operating limits specified in the TS. Normal reload design and analysis methodologies in use at TVA and at the fuel vendor will evaluate the Optimized ZIRLO clad fuel susceptibility to failure during normal operation, anticipated operational occurrences, and postulated accidents for each core design. Optimized ZIRLO fuel performance (as well as any co-resident Zircaloy and/or M5 clad fuel) in each core design will be evaluated and any predicted fuel failures will be limited such that dose consequence impacts are within the applicable regulatory limits. Therefore, the use of Optimized ZIRLO clad will not present an undue risk to the public health and safety.

E5-3 of 5 Sequoyah Nuclear Plant License Amendment Request

The exemption is consistent with the common defense and security. As previously noted, the exemption request is only to allow the application of the aforementioned regulations to Optimized ZIRLO, an improved fuel rod cladding material. All the 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 Optimized ZIRLO fuel rod cladding will not affect plant operations and is consistent with common defense and security. Therefore, the common defense and security are not impacted by this exemption request.

Special circumstances are present. 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 set forth in 10 CFR 50.12(a)(2)(ii), which states that special circumstances are present whenever:

"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..."

10 CFR 50.46 identifies acceptance criteria for ECCS system performance at nuclear power facilities. The effectiveness of the ECCS will not be affected by the use of Optimized ZIRLO clad fuel assemblies. Due to the similarities in the material properties of the Optimized ZIRLO to Zircaloy as identified in the Optimized ZIRLO topical report, it can be concluded that the ECCS effectiveness would not be adversely affected. Westinghouse has performed evaluations using approved Loss of Coolant Accident (LOCA) methods to ensure that assemblies with Optimized ZIRLO fuel rod cladding material meet all LOCA safety criteria.

The intent of paragraph I.A.5 of Appendix K to 10 CFR 50 is to apply an equation for rates of energy release, hydrogen generation, and cladding oxidation from the metal-water reaction that conservatively bounds all post-LOCA scenarios (i.e., the Baker-Just equation). The supporting documentation for the Optimized ZIRLO topical report shows that due to the similarities in the composition of the Zircaloy and Optimized ZIRLO, the application of the Baker-Just equation will continue to conservatively bound all post-LOCA scenarios.

The regulations of 10 CFR 50.46 and 10 CFR Part 50, Appendix K, make no provision for use of fuel rods clad in a material other than Zircaloy or ZIRLO®. Since the chemical composition of the Optimized ZIRLO alloy differs from the specifications for Zircaloy, a plant-specific exemption is required to allow the use of the Optimized ZIRLO alloy as a cladding material at Sequoyah Nuclear Station. The expected performance of Optimized ZIRLO clad material meets the intent of the regulations, as discussed in the Optimized ZIRLO topical report. Therefore, application of these regulations in this particular circumstance would not serve the underlying purpose of the rule and is not necessary to achieve the underlying purpose of the rule, so special circumstances exist.

E5-4 of 5 Sequoyah Nuclear Plant License Amendment Request

Conclusion

In order to support the use of Optimized ZIRLO 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.

References

1. WCAP-12610-P-A & CENPD-404-P-A, Addendum 1-A, “Optimized ZIRLOTM,” July 2006. 2. WCAP-12610-P-A, “VANTAGE+ Fuel Assembly Reference Core Report,” April 1995.

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