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MONTHYEARCNL-14-176, Application to Revise Technical Specification 6.8.4.h, Containment Leakage Rate Testing Program, (SQN-TS-14-03)2014-12-0202 December 2014 Application to Revise Technical Specification 6.8.4.h, Containment Leakage Rate Testing Program, (SQN-TS-14-03) Project stage: Request ML15016A2732015-01-16016 January 2015 E-mail Regarding Accepted for Review of Sequoyah Tech Spec Change Request Project stage: Approval CNL-15-171, Application to Revise Technical Specification 6.8.4.h, Containment Leakage Rate Testing Program, (SQN-TS-14-03) - Response to Request for Additional Information2015-09-11011 September 2015 Application to Revise Technical Specification 6.8.4.h, Containment Leakage Rate Testing Program, (SQN-TS-14-03) - Response to Request for Additional Information Project stage: Response to RAI CNL-15-218, Application to Revise Technical Specification 6.8.4.h, Containment Leakage Rate Testing Program, (SQN-TS-14-03) (TAC Nos. MF5366 and MF5367), Supplement to Response to Request for Additional Information2015-10-23023 October 2015 Application to Revise Technical Specification 6.8.4.h, Containment Leakage Rate Testing Program, (SQN-TS-14-03) (TAC Nos. MF5366 and MF5367), Supplement to Response to Request for Additional Information Project stage: Supplement 2015-01-16
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Category:Letter type:CNL
MONTHYEARCNL-24-017, Tennessee Valley Authority - Central Emergency Control Center Emergency Plan Implementing Procedure and Emergency Preparedness Department Procedure Revisions2024-01-17017 January 2024 Tennessee Valley Authority - Central Emergency Control Center Emergency Plan Implementing Procedure and Emergency Preparedness Department Procedure Revisions CNL-23-068, Request for Exemption from Enhanced Weapons, Firearms Background Checks, and Security Event Notifications Implementation2023-12-21021 December 2023 Request for Exemption from Enhanced Weapons, Firearms Background Checks, and Security Event Notifications Implementation CNL-23-036, Application to Revise Function 5 of Technical Specification Table 3.3.2-1, Engineered Safety Feature Actuation System Instrumentation, for the Sequoyah Nuclear Plant and Watts Bar Nuclear Plant (SQN-TS-23-02 and WBN-TS-23-08)2023-12-18018 December 2023 Application to Revise Function 5 of Technical Specification Table 3.3.2-1, Engineered Safety Feature Actuation System Instrumentation, for the Sequoyah Nuclear Plant and Watts Bar Nuclear Plant (SQN-TS-23-02 and WBN-TS-23-08) CNL-23-067, Central Emergency Control Center Emergency Plan Implementing Procedure Revisions2023-11-27027 November 2023 Central Emergency Control Center Emergency Plan Implementing Procedure Revisions CNL-23-061, Tennessee Valley Authority - Central Emergency Control Center Emergency Plan Implementing Procedure Revision2023-09-20020 September 2023 Tennessee Valley Authority - Central Emergency Control Center Emergency Plan Implementing Procedure Revision CNL-23-059, Supplement to Sequoyah Nuclear Plant, Units 1 and 2, and Watts Bar Nuclear Plant, Units 1 and 2, Application to Revise Technical Specifications to Adopt TSTF-567-A, Revision 1, Add Containment Sump TS to Address GSI-191 Issues (SQN-TS-23-2023-09-20020 September 2023 Supplement to Sequoyah Nuclear Plant, Units 1 and 2, and Watts Bar Nuclear Plant, Units 1 and 2, Application to Revise Technical Specifications to Adopt TSTF-567-A, Revision 1, Add Containment Sump TS to Address GSI-191 Issues (SQN-TS-23-03 CNL-23-057, Central Emergency Control Center Emergency Plan Implementing Procedure Revisions. Includes CECC-EPIP-1, Revision 76 and CECC-EPIP-9, Revision 642023-09-0505 September 2023 Central Emergency Control Center Emergency Plan Implementing Procedure Revisions. Includes CECC-EPIP-1, Revision 76 and CECC-EPIP-9, Revision 64 CNL-23-028, Application to Revise Technical Specifications to Adopt TSTF-567-A, Revision 1, Add Containment Sump TS to Address GSI-191 Issues (SQN-TS-23-03 and WBN-TS-23-06)2023-08-0202 August 2023 Application to Revise Technical Specifications to Adopt TSTF-567-A, Revision 1, Add Containment Sump TS to Address GSI-191 Issues (SQN-TS-23-03 and WBN-TS-23-06) CNL-23-055, Tennessee Valley Authority - Emergency Preparedness Department Procedure Revision. Includes EPDP-3, Revision 3, Emergency Plan Exercises and Preparedness Drills2023-07-25025 July 2023 Tennessee Valley Authority - Emergency Preparedness Department Procedure Revision. Includes EPDP-3, Revision 3, Emergency Plan Exercises and Preparedness Drills CNL-23-053, Tennessee Valley Authority - Radiological Emergency Plan Revisions2023-07-18018 July 2023 Tennessee Valley Authority - Radiological Emergency Plan Revisions CNL-23-049, Tennessee Valley Authority - Radiological Emergency Plan and Central Emergency Control Center Emergency Plan .2023-06-26026 June 2023 Tennessee Valley Authority - Radiological Emergency Plan and Central Emergency Control Center Emergency Plan . CNL-23-042, Radiological Emergency Plan and Central Emergency Control Center Emergency Plan Implementing Procedure Revisions2023-05-16016 May 2023 Radiological Emergency Plan and Central Emergency Control Center Emergency Plan Implementing Procedure Revisions CNL-23-032, Clinch River, Sequoyah, Units 1 and 2, Watts Bar, Unit 1 and 2, Nuclear Quality Assurance Plan, TVA-NQA-PLN89-A, Revision 412023-04-27027 April 2023 Clinch River, Sequoyah, Units 1 and 2, Watts Bar, Unit 1 and 2, Nuclear Quality Assurance Plan, TVA-NQA-PLN89-A, Revision 41 CNL-23-030, Tennessee Valley Authority - Hydrologic Engineering Center River Analysis System Project Milestone Status Update2023-04-27027 April 2023 Tennessee Valley Authority - Hydrologic Engineering Center River Analysis System Project Milestone Status Update CNL-23-033, Radiological Emergency Plan and Central Emergency Control Center Emergency Plan Implementing Procedure Revision2023-04-24024 April 2023 Radiological Emergency Plan and Central Emergency Control Center Emergency Plan Implementing Procedure Revision CNL-23-029, Radiological Emergency Plan and Central Emergency Control Center Emergency Plan Implementing Procedure Revisions2023-04-11011 April 2023 Radiological Emergency Plan and Central Emergency Control Center Emergency Plan Implementing Procedure Revisions CNL-23-012, Revision to the Application to Revise Updated Final Safety Analysis Report Regarding Changes to Hydrologic Analysis, (TS-19-02)2023-04-11011 April 2023 Revision to the Application to Revise Updated Final Safety Analysis Report Regarding Changes to Hydrologic Analysis, (TS-19-02) CNL-23-023, Annual Insurance Status Report2023-03-30030 March 2023 Annual Insurance Status Report CNL-23-024, TVA Guarantee of Payment of Deferred Premiums - 2022 Annual Report2023-03-29029 March 2023 TVA Guarantee of Payment of Deferred Premiums - 2022 Annual Report CNL-23-022, Decommissioning Funding Status Report2023-03-29029 March 2023 Decommissioning Funding Status Report CNL-23-021, Radiological Emergency Plan and Central Emergency Control Center Emergency Plan Implementing Procedure Revisions2023-03-0808 March 2023 Radiological Emergency Plan and Central Emergency Control Center Emergency Plan Implementing Procedure Revisions CNL-22-037, Application to Revise Technical Specifications to Adopt TSTF-541-A, Add Exceptions to Surveillance Requirements for Valves and Dampers Locked in the Actuated Position (BFN TS-533)2023-01-31031 January 2023 Application to Revise Technical Specifications to Adopt TSTF-541-A, Add Exceptions to Surveillance Requirements for Valves and Dampers Locked in the Actuated Position (BFN TS-533) CNL-23-003, Browns Nuclear Plant, Units 1, 2 & 3; Sequoyah Nuclear Plant, Units 1 & 2; and Watts Bar Nuclear Plant, Units 1 & 2 - Organizational Topic Report TVA-NPOD89-A2023-01-30030 January 2023 Browns Nuclear Plant, Units 1, 2 & 3; Sequoyah Nuclear Plant, Units 1 & 2; and Watts Bar Nuclear Plant, Units 1 & 2 - Organizational Topic Report TVA-NPOD89-A CNL-23-011, Steam Generator Tube Inspection Report to Reflect TSTF-577 Reporting Requirements2023-01-18018 January 2023 Steam Generator Tube Inspection Report to Reflect TSTF-577 Reporting Requirements CNL-23-009, Response to Request for Additional Information Request to Revise Technical Specification 3.4.122023-01-0404 January 2023 Response to Request for Additional Information Request to Revise Technical Specification 3.4.12 CNL-23-008, Tennessee Valley Authority Radiological Emergency Plan and Central Emergency Control Center Emergency Plan Implementing Procedure Revisions2022-12-22022 December 2022 Tennessee Valley Authority Radiological Emergency Plan and Central Emergency Control Center Emergency Plan Implementing Procedure Revisions CNL-22-106, Tennessee Valley Authority - Radiological Emergency Plan and Central Emergency Control Center Emergency Plan Implementing Procedure Revision. Includes CECC EPIP-14, Revision 38, Nuclear Emergency Public Information Organization and Operat2022-11-28028 November 2022 Tennessee Valley Authority - Radiological Emergency Plan and Central Emergency Control Center Emergency Plan Implementing Procedure Revision. Includes CECC EPIP-14, Revision 38, Nuclear Emergency Public Information Organization and Operatio CNL-22-099, Tennessee Valley Authority - Hydrologic Engineering Center River Analysis System Project Milestone Status Update2022-10-31031 October 2022 Tennessee Valley Authority - Hydrologic Engineering Center River Analysis System Project Milestone Status Update CNL-22-104, Correction to Response to Request for Additional Information Regarding Sequoyah Nuclear Plant, Units 1 and 2, American Society of Mechanical Engineers Operation and Maintenance Code, Request for Alternative RV-022022-10-31031 October 2022 Correction to Response to Request for Additional Information Regarding Sequoyah Nuclear Plant, Units 1 and 2, American Society of Mechanical Engineers Operation and Maintenance Code, Request for Alternative RV-02 CNL-22-098, Tennessee Valley Authority - Radiological Emergency Plan and Central Emergency Control Center Emergency Plan Implementing Procedure Revisions. Includes CECC EPIP-7, Rev. 45 & CECC EPIP-8, Rev. 552022-10-17017 October 2022 Tennessee Valley Authority - Radiological Emergency Plan and Central Emergency Control Center Emergency Plan Implementing Procedure Revisions. Includes CECC EPIP-7, Rev. 45 & CECC EPIP-8, Rev. 55 CNL-22-084, Response to Request for Additional Information Regarding License Amendment Request to License Amendment Request to Modify Approved 10 CFR 50.69 Categorization Process (SQN-TS-21-07)2022-09-16016 September 2022 Response to Request for Additional Information Regarding License Amendment Request to License Amendment Request to Modify Approved 10 CFR 50.69 Categorization Process (SQN-TS-21-07) CNL-22-085, Response to Request for Additional Information Regarding Sequoyah Nuclear Plant (Sqn), Units 1 and 2 and Watts Bar Nuclear Plant (Wbn), Units 1 and 2, American Society of Mechanical Engineers Operation and Maintenance Code, Request for Al2022-09-0202 September 2022 Response to Request for Additional Information Regarding Sequoyah Nuclear Plant (Sqn), Units 1 and 2 and Watts Bar Nuclear Plant (Wbn), Units 1 and 2, American Society of Mechanical Engineers Operation and Maintenance Code, Request for Alte CNL-22-053, Response to Request for Additional Information Regarding Application to Revise Sequoyah Nuclear Plant Units 1 and 2 Updated Final Safety Analysis Report Regarding Changes to Hydrologic Analysis - Second Partial Response to Additional Requ2022-08-22022 August 2022 Response to Request for Additional Information Regarding Application to Revise Sequoyah Nuclear Plant Units 1 and 2 Updated Final Safety Analysis Report Regarding Changes to Hydrologic Analysis - Second Partial Response to Additional Reques CNL-22-077, Radiological Emergency Plan and Central Emergency Control Center Emergency Plan Implementing Procedure Revisions2022-08-11011 August 2022 Radiological Emergency Plan and Central Emergency Control Center Emergency Plan Implementing Procedure Revisions CNL-22-030, Application to Revise Technical Specification 3.4.12, Low Temperature Overpressure Protection System for Sequoyah Nuclear Plant (SQN-TSC-22-01) and TS 3.4.12 Cold Overpressure Mitigation System for Watts Bar Nuclear Plant (WBN-TS-22-03)2022-07-27027 July 2022 Application to Revise Technical Specification 3.4.12, Low Temperature Overpressure Protection System for Sequoyah Nuclear Plant (SQN-TSC-22-01) and TS 3.4.12 Cold Overpressure Mitigation System for Watts Bar Nuclear Plant (WBN-TS-22-03) CNL-22-080, Request for Enforcement Discretion from the Requirements of Technical Specification 3.5.2, ECCS - Operating2022-07-22022 July 2022 Request for Enforcement Discretion from the Requirements of Technical Specification 3.5.2, ECCS - Operating CNL-22-081, Supplement to Sequoyah Nuclear Plant, Unit 1, American Society of Mechanical Engineers Operation and Maintenance Code, Request for Alternative RP-122022-07-21021 July 2022 Supplement to Sequoyah Nuclear Plant, Unit 1, American Society of Mechanical Engineers Operation and Maintenance Code, Request for Alternative RP-12 CNL-22-079, American Society of Mechanical Engineers Operation and Maintenance Code, Request for Alternative RP-122022-07-20020 July 2022 American Society of Mechanical Engineers Operation and Maintenance Code, Request for Alternative RP-12 CNL-22-071, Supplement to Application to Revise Technical Specifications to Adopt TSTF-577, Revised Frequencies for Steam Generator Tube Inspections (SQN-TS-21-03 and WBN-TS-21-08)2022-07-13013 July 2022 Supplement to Application to Revise Technical Specifications to Adopt TSTF-577, Revised Frequencies for Steam Generator Tube Inspections (SQN-TS-21-03 and WBN-TS-21-08) CNL-22-039, Application to Revise Technical Specifications to Adopt TSTF-554-A, Revision 1, Revise Reactor Coolant Leakage Requirements (BFN TS-537) (SQN-21-05) (WBN-TS-21-04)2022-07-13013 July 2022 Application to Revise Technical Specifications to Adopt TSTF-554-A, Revision 1, Revise Reactor Coolant Leakage Requirements (BFN TS-537) (SQN-21-05) (WBN-TS-21-04) CNL-22-069, Response to Request for Additional Information Regarding License Amendment Request to Revise Technical Specifications to Adopt Risk-Informed Completion Times TSTF-505, Revision 2, Provide Risk-Informed Extended Completion Times - Ritstf.2022-07-0101 July 2022 Response to Request for Additional Information Regarding License Amendment Request to Revise Technical Specifications to Adopt Risk-Informed Completion Times TSTF-505, Revision 2, Provide Risk-Informed Extended Completion Times - Ritstf. CNL-22-070, Status Regarding the Improved Flood Mitigation System Project2022-06-30030 June 2022 Status Regarding the Improved Flood Mitigation System Project CNL-22-062, Response to Request for Additional Information Regarding American Society of Mechanical Engineers Operation and Maintenance Code, Request for Alternative RV-022022-06-28028 June 2022 Response to Request for Additional Information Regarding American Society of Mechanical Engineers Operation and Maintenance Code, Request for Alternative RV-02 CNL-22-008, and Watts Bar Nuclear Plant - Application to Revise Technical Specifications to Adopt TSTF-529, Clarify Use and Application Rules (BFN-TS-541, SQN-TS-21-09, and WBN-TS-22-002)2022-06-13013 June 2022 and Watts Bar Nuclear Plant - Application to Revise Technical Specifications to Adopt TSTF-529, Clarify Use and Application Rules (BFN-TS-541, SQN-TS-21-09, and WBN-TS-22-002) CNL-22-064, Response to Request for Additional Information Regarding Tennessee Valley Authority License Amendment Request to Revise Emergency Plan Implementing Procedure Regarding Seismic Event Emergency Action Level Change2022-06-0909 June 2022 Response to Request for Additional Information Regarding Tennessee Valley Authority License Amendment Request to Revise Emergency Plan Implementing Procedure Regarding Seismic Event Emergency Action Level Change CNL-22-068, Tennessee Valley Authority - Radiological Emergency Plan and Central Emergency Control Center Emergency Plan Implementing Procedure Revisions2022-06-0808 June 2022 Tennessee Valley Authority - Radiological Emergency Plan and Central Emergency Control Center Emergency Plan Implementing Procedure Revisions CNL-22-047, Central Emergency Control Center Emergency Plan Implementing Procedure and Emergency Preparedness Department Procedure Revisions2022-05-23023 May 2022 Central Emergency Control Center Emergency Plan Implementing Procedure and Emergency Preparedness Department Procedure Revisions CNL-22-034, Second Supplement to License Amendment Request to Revise Technical Specifications to Adopt Risk-Informed Completion Times TSTF-505, Revision 2, Provide Risk-Informed Extended Completion Times - RITSTF Initiative 4b (SQN-TS-20-03)2022-05-13013 May 2022 Second Supplement to License Amendment Request to Revise Technical Specifications to Adopt Risk-Informed Completion Times TSTF-505, Revision 2, Provide Risk-Informed Extended Completion Times - RITSTF Initiative 4b (SQN-TS-20-03) CNL-22-027, Clinch River, Sequoyah, Units 1 and 2, Watts Bar, Unit 1 and 2, Nuclear Quality Assurance Plan, TVA-NQA-PLN89-A, Revision 40 - Annual Update and Proposed Changes to Revision 402022-04-28028 April 2022 Clinch River, Sequoyah, Units 1 and 2, Watts Bar, Unit 1 and 2, Nuclear Quality Assurance Plan, TVA-NQA-PLN89-A, Revision 40 - Annual Update and Proposed Changes to Revision 40 CNL-22-023, Supplement to License Amendment Request to Revise Technical Specifications to Adopt Risk-Informed Completion Times TSTF-505, Revision 2, Provide Risk-Informed Extended Completion Times - Ritstf2022-04-28028 April 2022 Supplement to License Amendment Request to Revise Technical Specifications to Adopt Risk-Informed Completion Times TSTF-505, Revision 2, Provide Risk-Informed Extended Completion Times - Ritstf 2024-01-17
[Table view] Category:Response to Request for Additional Information (RAI)
MONTHYEARML24004A0402024-01-0303 January 2024 Response to NRCs November 8, 2023, Request for Additional Information - Related to Independent Spent Fuel Storage Installation ML23117A1162023-04-27027 April 2023 Response to Follow-up Questions to TVAs Response to NRCs Request for Supplemental Information (Rsi) Related to August 4, 2022, Sequoyah ISFSI Exemption Request CNL-23-009, Response to Request for Additional Information Request to Revise Technical Specification 3.4.122023-01-0404 January 2023 Response to Request for Additional Information Request to Revise Technical Specification 3.4.12 ML22353A0662022-12-19019 December 2022 Response to Request for Supplemental Information (D-RSI) Request for Exemption from Non-Destruction-Examination Compliance CNL-22-084, Response to Request for Additional Information Regarding License Amendment Request to License Amendment Request to Modify Approved 10 CFR 50.69 Categorization Process (SQN-TS-21-07)2022-09-16016 September 2022 Response to Request for Additional Information Regarding License Amendment Request to License Amendment Request to Modify Approved 10 CFR 50.69 Categorization Process (SQN-TS-21-07) CNL-22-085, Response to Request for Additional Information Regarding Sequoyah Nuclear Plant (Sqn), Units 1 and 2 and Watts Bar Nuclear Plant (Wbn), Units 1 and 2, American Society of Mechanical Engineers Operation and Maintenance Code, Request for Al2022-09-0202 September 2022 Response to Request for Additional Information Regarding Sequoyah Nuclear Plant (Sqn), Units 1 and 2 and Watts Bar Nuclear Plant (Wbn), Units 1 and 2, American Society of Mechanical Engineers Operation and Maintenance Code, Request for Alte CNL-22-053, Response to Request for Additional Information Regarding Application to Revise Sequoyah Nuclear Plant Units 1 and 2 Updated Final Safety Analysis Report Regarding Changes to Hydrologic Analysis - Second Partial Response to Additional Requ2022-08-22022 August 2022 Response to Request for Additional Information Regarding Application to Revise Sequoyah Nuclear Plant Units 1 and 2 Updated Final Safety Analysis Report Regarding Changes to Hydrologic Analysis - Second Partial Response to Additional Reques CNL-22-069, Response to Request for Additional Information Regarding License Amendment Request to Revise Technical Specifications to Adopt Risk-Informed Completion Times TSTF-505, Revision 2, Provide Risk-Informed Extended Completion Times - Ritstf.2022-07-0101 July 2022 Response to Request for Additional Information Regarding License Amendment Request to Revise Technical Specifications to Adopt Risk-Informed Completion Times TSTF-505, Revision 2, Provide Risk-Informed Extended Completion Times - Ritstf. CNL-22-062, Response to Request for Additional Information Regarding American Society of Mechanical Engineers Operation and Maintenance Code, Request for Alternative RV-022022-06-28028 June 2022 Response to Request for Additional Information Regarding American Society of Mechanical Engineers Operation and Maintenance Code, Request for Alternative RV-02 CNL-22-064, Response to Request for Additional Information Regarding Tennessee Valley Authority License Amendment Request to Revise Emergency Plan Implementing Procedure Regarding Seismic Event Emergency Action Level Change2022-06-0909 June 2022 Response to Request for Additional Information Regarding Tennessee Valley Authority License Amendment Request to Revise Emergency Plan Implementing Procedure Regarding Seismic Event Emergency Action Level Change CNL-21-024, Partial Response to Additional Request for Information Re Application to Revise Updated Final Safety Analysis Report Re Changes to Hydrologic Analysis (TS-19-02)2021-06-15015 June 2021 Partial Response to Additional Request for Information Re Application to Revise Updated Final Safety Analysis Report Re Changes to Hydrologic Analysis (TS-19-02) CNL-21-039, Response to Request for Additional Information Re Application to Modify Technical Specification to Allow for Transition to Westinghouse RFA-2 Fuel (SQN-TS-20-09)2021-05-0505 May 2021 Response to Request for Additional Information Re Application to Modify Technical Specification to Allow for Transition to Westinghouse RFA-2 Fuel (SQN-TS-20-09) CNL-20-082, Partial Response to Request for Additional Information Regarding Application to Revise Updated Final Safety Analysis Report Regarding Changes to Hydrologic Analysis (TS-19-02)2020-11-10010 November 2020 Partial Response to Request for Additional Information Regarding Application to Revise Updated Final Safety Analysis Report Regarding Changes to Hydrologic Analysis (TS-19-02) CNL-20-076, Response to Request for Additional Information Re Application to Revise Sequoyah Nuclear Plant (SQN) Unit 1 Technical Specifications for Steam Generator Tube Inspection Frequency (SQN-TS-20-01)2020-09-23023 September 2020 Response to Request for Additional Information Re Application to Revise Sequoyah Nuclear Plant (SQN) Unit 1 Technical Specifications for Steam Generator Tube Inspection Frequency (SQN-TS-20-01) CNL-20-057, Tennessee Valley Authority - Application to Revise Sequoyah Nuclear Plant Units 1 & 2 Updated FSAR Changes to Hydrologic Analysis - Partial Response to Additional Request for Additional Information (TS-19-02)2020-08-12012 August 2020 Tennessee Valley Authority - Application to Revise Sequoyah Nuclear Plant Units 1 & 2 Updated FSAR Changes to Hydrologic Analysis - Partial Response to Additional Request for Additional Information (TS-19-02) ML20196L6892020-07-16016 July 2020 TVA Non-Proprietary Slides for Open Session of July 16, 2020, Partially Closed Public Meeting to Discuss Sequoyah License Amendment Request CNL-20-032, Response to Request for Additional Information (TS-19-02) Application to Revise Updated Final Safety Analysis Report Regarding Changes to Hydrologic Analysis2020-05-14014 May 2020 Response to Request for Additional Information (TS-19-02) Application to Revise Updated Final Safety Analysis Report Regarding Changes to Hydrologic Analysis CNL-20-026, Supplement to Application to Revise Sequoyah Nuclear Plant Units 1 and 2 Updated Final Safety Analysis Report Regarding Changes to Hydrologic Analysis, (TS-19-02)2020-02-18018 February 2020 Supplement to Application to Revise Sequoyah Nuclear Plant Units 1 and 2 Updated Final Safety Analysis Report Regarding Changes to Hydrologic Analysis, (TS-19-02) CNL-19-119, Response to Request for Additional Information Regarding Sequoyah Nuclear Plant, Unit 1 Exigent License Amendment Request to Revise Technical Specification 4.2.2, Control Rod Assemblies (SQN-TS-19-05)2019-11-19019 November 2019 Response to Request for Additional Information Regarding Sequoyah Nuclear Plant, Unit 1 Exigent License Amendment Request to Revise Technical Specification 4.2.2, Control Rod Assemblies (SQN-TS-19-05) CNL-19-061, Seismic Probabilistic Risk Assessment for Sequoyah Nuclear Plant, Units 1 and 2 - Response to NRC Request for Information Pursuant to Title 10 of the Code of Federal Regulations 50.54(f) Regarding Recommendation 2.1 of the Near-Term Task2019-10-18018 October 2019 Seismic Probabilistic Risk Assessment for Sequoyah Nuclear Plant, Units 1 and 2 - Response to NRC Request for Information Pursuant to Title 10 of the Code of Federal Regulations 50.54(f) Regarding Recommendation 2.1 of the Near-Term Task Fo ML19231A2082019-08-19019 August 2019 Response to Request for Information Regarding Unit 2 Cycle 22 - 180-Day Steam Generator Tube Inspection Report CNL-19-068, Response to Request for Additional Information Regarding the Sequoyah Nuclear Plant (SQN) Units 1 and 2 and Watts Bar Nuclear Plant (WBN) Units 1 and 2, American Society of Mechanical Engineers Operation and Maintenance Code, Request for2019-07-22022 July 2019 Response to Request for Additional Information Regarding the Sequoyah Nuclear Plant (SQN) Units 1 and 2 and Watts Bar Nuclear Plant (WBN) Units 1 and 2, American Society of Mechanical Engineers Operation and Maintenance Code, Request for .. CNL-19-057, Response to Request for Additional Information Regarding American Society of Mechanical Engineers Boiler and Pressure Vessel Code Section XI, Inservice Inspection Program, Request for Alternative, 18-ISl-12019-06-19019 June 2019 Response to Request for Additional Information Regarding American Society of Mechanical Engineers Boiler and Pressure Vessel Code Section XI, Inservice Inspection Program, Request for Alternative, 18-ISl-1 CNL-19-002, Response to Request for Additional Information Regarding Application to Modify Sequoyah Nuclear Plant Units 1 and 2, Application to Adopt 10 CFR 50.69, Risk-Informed Categorization and Treatment of Structures,.2019-03-21021 March 2019 Response to Request for Additional Information Regarding Application to Modify Sequoyah Nuclear Plant Units 1 and 2, Application to Adopt 10 CFR 50.69, Risk-Informed Categorization and Treatment of Structures,. CNL-19-016, Response to Request for Additional Information on License Amendment Request to Modify Essential Raw Cooling Water Motor Control Center Breakers and to Revise the Updated Final Safety Analysis Report2019-01-30030 January 2019 Response to Request for Additional Information on License Amendment Request to Modify Essential Raw Cooling Water Motor Control Center Breakers and to Revise the Updated Final Safety Analysis Report CNL-18-089, Response to Request for Additional Information Regarding Decommissioning Funding Plan Update for Browns Ferry Nuclear Plant and Sequoyah Nuclear Plant Independent Spent Fuel Storage Installations, Docket Nos. 72-052 and 72-0342018-07-23023 July 2018 Response to Request for Additional Information Regarding Decommissioning Funding Plan Update for Browns Ferry Nuclear Plant and Sequoyah Nuclear Plant Independent Spent Fuel Storage Installations, Docket Nos. 72-052 and 72-034 NL-18-044, Browns Ferry Units 1, 2, and 3; Sequoyah Units 1 and 2; Watts Bar Units 1 and 2 - Tennessee Valley Authority Response to NRC Request for Additional Information Related to Topical Report TVA-NPG-AWA16, TVA Overall Basin Probable Maximum Pre2018-04-19019 April 2018 Browns Ferry Units 1, 2, and 3; Sequoyah Units 1 and 2; Watts Bar Units 1 and 2 - Tennessee Valley Authority Response to NRC Request for Additional Information Related to Topical Report TVA-NPG-AWA16, TVA Overall Basin Probable Maximum Prec CNL-18-044, Tennessee Valley Authority Response to NRC Request for Additional Information Related to Topical Report TVA-NPG-AWA16, TVA Overall Basin Probable Maximum Precipitation.2018-04-19019 April 2018 Tennessee Valley Authority Response to NRC Request for Additional Information Related to Topical Report TVA-NPG-AWA16, TVA Overall Basin Probable Maximum Precipitation. CNL-17-063, Response to Request for Additional Information (RAI) Regarding Application to Modify Technical Specifications Regarding Diesel Generator Steady State Frequency (SQN-TS-14-02)2017-10-26026 October 2017 Response to Request for Additional Information (RAI) Regarding Application to Modify Technical Specifications Regarding Diesel Generator Steady State Frequency (SQN-TS-14-02) CNL-17-104, Response to Request for Additional Information Regarding Proposed Technical Specification Change to Revise the Note Modifying SR 3.8.1.17 of TS 3.8.1 AC Sources - Operating (TS-SQN-16-04)2017-08-0707 August 2017 Response to Request for Additional Information Regarding Proposed Technical Specification Change to Revise the Note Modifying SR 3.8.1.17 of TS 3.8.1 AC Sources - Operating (TS-SQN-16-04) CNL-17-098, Revised Response to NRC Request for Additional Information Related to TVA Fleet License Amendment Request to Adopt NEI 99-01 Revision 6 Emergency Action Levels2017-07-27027 July 2017 Revised Response to NRC Request for Additional Information Related to TVA Fleet License Amendment Request to Adopt NEI 99-01 Revision 6 Emergency Action Levels CNL-17-085, Response to NRC Request for Additional Information Related to TVA Fleet License Amendment Request to Adopt NEI 99-01 Revision 6 Emergency Action Levels2017-07-0707 July 2017 Response to NRC Request for Additional Information Related to TVA Fleet License Amendment Request to Adopt NEI 99-01 Revision 6 Emergency Action Levels CNL-17-039, Response to NRC Request for Information, Per 10CFR50.54(f) Regarding Recommendations 2.1, 2.3 and 9.3 of the Near-Term Task Force Review of Insights from the Fukushima Dai-Ichi Accident - Withdrawal of Regulatory..2017-03-10010 March 2017 Response to NRC Request for Information, Per 10CFR50.54(f) Regarding Recommendations 2.1, 2.3 and 9.3 of the Near-Term Task Force Review of Insights from the Fukushima Dai-Ichi Accident - Withdrawal of Regulatory.. CNL-16-194, Response to NRC Request for Information Pursuant to Title 10 of the Code of Federal Regulations 50.54(f) Regarding Recommendation 2.1 of the Near-Term Task Force Review of Insights from the Fukushima Dai-ichi Accid2016-12-23023 December 2016 Response to NRC Request for Information Pursuant to Title 10 of the Code of Federal Regulations 50.54(f) Regarding Recommendation 2.1 of the Near-Term Task Force Review of Insights from the Fukushima Dai-ichi Accid CNL-16-178, Response to Request for Additional Information (RAI) Regarding Application to Modify Technical Specifications Regarding Diesel Generator Steady State Frequency (SQN-TS-14-02)2016-12-23023 December 2016 Response to Request for Additional Information (RAI) Regarding Application to Modify Technical Specifications Regarding Diesel Generator Steady State Frequency (SQN-TS-14-02) CNL-16-196, Revised Response to NRC Generic Letter 2016-01, Monitoring of Neutron-Absorbing Materials in Spent Fuel Pools2016-12-19019 December 2016 Revised Response to NRC Generic Letter 2016-01, Monitoring of Neutron-Absorbing Materials in Spent Fuel Pools CNL-16-123, Response to NRC Request for Additional Information Request for Approval for Use of Alternate Calibration Block Reflector Requirements 16-PDI-52016-07-28028 July 2016 Response to NRC Request for Additional Information Request for Approval for Use of Alternate Calibration Block Reflector Requirements 16-PDI-5 CNL-16-086, Response to Request for Additional Information Technical Specifications 3.7.8 Change - Essential Raw Cooling Water System2016-05-31031 May 2016 Response to Request for Additional Information Technical Specifications 3.7.8 Change - Essential Raw Cooling Water System CNL-15-218, Application to Revise Technical Specification 6.8.4.h, Containment Leakage Rate Testing Program, (SQN-TS-14-03) (TAC Nos. MF5366 and MF5367), Supplement to Response to Request for Additional Information2015-10-23023 October 2015 Application to Revise Technical Specification 6.8.4.h, Containment Leakage Rate Testing Program, (SQN-TS-14-03) (TAC Nos. MF5366 and MF5367), Supplement to Response to Request for Additional Information CNL-15-171, Application to Revise Technical Specification 6.8.4.h, Containment Leakage Rate Testing Program, (SQN-TS-14-03) - Response to Request for Additional Information2015-09-11011 September 2015 Application to Revise Technical Specification 6.8.4.h, Containment Leakage Rate Testing Program, (SQN-TS-14-03) - Response to Request for Additional Information CNL-15-158, Supplement to TVA Letter, Sequoyah Nuclear Plant - Revision to Commitment No. 28 and Review of Impacts to the SQN Reactor Vessel Internals Aging Management Program Due to Dislodged Reactor Vessel Surveillance Capsules in Unit 1 Reactor.2015-08-0303 August 2015 Supplement to TVA Letter, Sequoyah Nuclear Plant - Revision to Commitment No. 28 and Review of Impacts to the SQN Reactor Vessel Internals Aging Management Program Due to Dislodged Reactor Vessel Surveillance Capsules in Unit 1 Reactor. CNL-15-146, Response to NRC Request for Information Regarding the Review of the License Renewal Application, Set 25 (TAC Nos. MF0481 and MF0482)2015-08-0303 August 2015 Response to NRC Request for Information Regarding the Review of the License Renewal Application, Set 25 (TAC Nos. MF0481 and MF0482) NL-15-158, Supplement to TVA Letter, Sequoyah Nuclear Plant - Revision to Commitment No. 28 and Review of Impacts to the SQN Reactor Vessel Internals Aging Management Program Due to Dislodged Reactor Vessel Surveillance Capsules in Unit 1 Reactor.2015-08-0303 August 2015 Supplement to TVA Letter, Sequoyah Nuclear Plant - Revision to Commitment No. 28 and Review of Impacts to the SQN Reactor Vessel Internals Aging Management Program Due to Dislodged Reactor Vessel Surveillance Capsules in Unit 1 Reactor. CNL-15-136, Response to NRC Request for Additional Information Regarding ASME Request for Relief RP-072015-07-22022 July 2015 Response to NRC Request for Additional Information Regarding ASME Request for Relief RP-07 ML15176A6822015-06-19019 June 2015 Sequoyah Nuclear Plants, Units 1 and 2 Technical Specifications Conversion to NUREG-1431, Rev. 4.0 (SQN-TS-11-10) - Supplement 2. Part 4 of 8 ML15176A6812015-06-19019 June 2015 Sequoyah Nuclear Plants, Units 1 and 2 Technical Specifications Conversion to NUREG-1431, Rev. 4.0 (SQN-TS-11-10) - Supplement 2. Part 3 of 8 ML15176A7482015-06-19019 June 2015 Plants, Units 1 and 2 Technical Specifications Conversion to NUREG-1431, Rev. 4.0 (SQN-TS-11-10) - Supplement 2. Part 8 of 8 ML15176A7402015-06-19019 June 2015 Plants, Units 1 and 2 Technical Specifications Conversion to NUREG-1431, Rev. 4.0 (SQN-TS-11-10) - Supplement 2. Part 7 of 8 ML15176A6792015-06-19019 June 2015 Sequoyah Nuclear Plants, Units 1 and 2 Technical Specifications Conversion to NUREG-1431, Rev. 4.0 (SQN-TS-11-10) - Supplement 2. Part 2 of 8 ML15176A6642015-06-19019 June 2015 Sequoyah Nuclear Plants, Units 1 and 2 Technical Specifications Conversion to NUREG-1431, Rev. 4.0 (SQN-TS-11-10) - Supplement 2. Part 1 of 8 2024-01-03
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1101 Market Street, Chattanooga, Tennessee 37402 CNL-15-171 September 11, 2015 10 CFR 50.90 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555-0001 Sequoyah Nuclear Plant, Units 1 and 2 Facility Operating License Nos. DPR-77 and DPR-79 NRC Docket Nos. 50-327 and 50-328
Subject:
Application to Revise Technical Specification 6.8.4.h, "Containment Leakage Rate Testing Program," (SQN-TS-14-03) (TAC Nos. MF5366 and MF5367),
Response to Request for Additional Information
References:
- 1. Letter from TVA to NRC, CNL-14-176, "Application to Revise Technical Specification 6.8.4.h, "Containment Leakage Rate Testing Program,"
(SQN-TS-14-03)," dated December 2, 2014 (ADAMS Accession No. ML14339A539)
- 2. Nuclear Energy Institute 94-01, Revision 3-A, "Industry Guideline for Implementing Performance-Based Option of 10 CFR Part 50, Appendix J," dated July 2012 (ADAMS Accession No. ML12221A202)
- 3. Electronic mail from Andrew Hon (NRC) to Joseph W. Shea (TVA),
"Sequoyah Nuclear Station, Unit 1 & 2 - Request for Additional Information Related to LAR to Revise Containment Leakage Rate Testing Program," dated August 6, 2015 By letter dated December 2, 2014 (Reference 1), Tennessee Valley Authority (TVA) submitted a license amendment request (LAR) for Sequoyah Nuclear Plant (SQN), Units 1 and 2, revising the SQN, Units 1 and 2, Technical Specifications (TS) 6.8.4.h, "Containment Leakage Rate Testing Program," by adopting Nuclear Energy Institute (NEI) 94-01, Revision 3-A, "Industry Guideline for Implementing Performance-Based Option of 10 CFR Part 50, Appendix J," (Reference 2) as the implementation document for the performance-based Option B of 10 CFR Part 50, Appendix J. The proposed changes permanently extend the Type A containment integrated leak rate testing (ILRT) interval from 10 years to 15 years and the Type C local leakage rate testing intervals from 60 months to 75 months.
U.S. Nuclear Regulatory Commission CNL-15-171 Page 2 September 11, 2015 By electronic mail dated August 6, 2015 (Reference 3), the Nuclear Regulatory Commission (NRC) requested additional information to support the review of the LAR. The response to the request for additional information (RAI) is due September 8, 2015. During a telephone conversation with the NRC Project Manager on September 2, 2015, the due date for the response to the RAI was extended to September 10, 2015. to this letter provides TVA's RAI responses. There are no changes required to the LAR as submitted in the Reference 1 letter as a result of this additional information. to this letter provides a list of regulatory commitments containing one new regulatory commitment.
Consistent with the standards set forth in Title 1O of the Code of Federal Regulations (10 CFR), Part 50.92(c), TVA has determined that the additional information, as provided in this letter, does not affect the no significant hazards consideration associated with the proposed application previously provided in Reference 1.
Additionally, in accordance with 10 CFR 50.91(b)(1 ), TVA is sending a copy of this letter and the enclosure to the Tennessee Department of Environment and Conservation.
There is one new regulatory commitment contained in this submittal. Please address any questions regarding this request to Mr. Edward D. Schrull at (423) 751-3850.
I declare under penalty of perjury that the foregoing is true and correct. Executed on this 11th day of September 2015.
ully,
.*Shea President, Nuclear Licensing
Enclosures:
- 1. Response to Request for Additional Information
- 2. List of Regulatory Commitments Enclosures 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
ENCLOSURE 1 TENNESSEE VALLEY AUTHORITY SEQUOYAH NUCLEAR PLANT UNITS 1 AND 2 Response to Request for Additional Information Request for Additional Information (RAI) RAI 1 Section 4.4.1 of the LAR indicates that SQN, Units 1 and 2, have completed requirements of the first period, second 10-year interval containment IWE in-service inspection and no detrimental flaws have been observed to date. A table has been provided in Section 4.4 of the LAR which indicates that a general visual examination of accessible interior surface of the Unit 1 containment vessel was planned for April 2015. Considering that the LAR may not include the latest inspection results, please discuss the highlights of those inspections and corrective actions (if any) performed subsequent to the submittal of the LAR that relate to the structural integrity and leak-tightness of the SQN Units 1 and 2 primary containments.
TVA Response Since the License Amendment Request (LAR) was submitted on December 2, 2014, only the Sequoyah Nuclear Plant (SQN), Unit 1 containment has been examined. Examinations of the moisture barrier, thermal barrier, Steel Containment Vessel (SCV) inboard and outboard surfaces, and penetration X-129E were completed for the SQN, Unit 1 containment in April and May of 2015 during refueling outage U1R20. The results of these examinations are summarized as follows.
Moisture Barrier The General Visual Examination of the moisture barrier found five areas with indications of loss of adhesion. The areas were excavated after the initial examination. Excavated areas were examined and found to be acceptable. Following excavation and examination, the sealant was reapplied and the areas were reexamined. The resealed areas were found to be acceptable.
Thermal Barrier All loose seams in the Thermal Barrier were caulked.
Steel Containment Vessel The General Visual Examination of the SCV found signs of distress and rust at penetration X-155. There were previously reported indications of coating/paint flaking at various locations on the SCV inboard surface. The SCV outboard surface had scratches and scrapes with light to medium rust, but no recordable indications were found.
None of the indications are greater than 10% of the SCV thickness. There is no effect to the structural integrity of the SCV. There is no indication that an adverse condition exists. The indications were determined to be acceptable for continued service. Successive examinations will be performed next inspection period as prescribed in IWE 2420(b).
Penetration X-129E The American Society of Mechanical Engineers (ASME)Section XI VT-2 Visual Examination found no recordable indications.
CNL-15-171 Enclosure 1, Page 1 of 9
RAI 2
Section 4.4.2 of the LAR states that the Class CC equivalent components at SQN (i.e., the structural base slab and metal liner) are exempt from examination based on the exemptions of IWL-1220(b) and IWE-1220(b). The structural base slab and metal liner are covered with concrete, which forms the reactor building floor and results in these components being inaccessible for examination.
Please provide the timing, frequency, and the extent of inspections for monitoring the aging effects of the reinforced concrete components in accessible areas performed as part of the SQN in-service inspection program and structures monitoring program. Also, provide discussion and demonstrate that there is reasonable assurance that the containment vessel reinforced concrete foundation mat is adequately monitored for its performance or condition in a manner that allows for timely identification and correction of degraded conditions. The response to this request for additional information should also include the results of recent inspections of the SQN Units 1 and 2 shield buildings.
TVA Response A General Examination of containment surfaces is performed in accordance with Section XI, IWE-2412-1 and Table IWE-2500-1 during each inspection period. This is an examination of exposed accessible interior and exterior surfaces of the SCV to verify that no evidence of structural deterioration exists which may affect either the containment structural integrity or leak tightness. In accordance with site procedures special emphasis is placed on the liner to concrete interface areas inside the Annulus and Raceway.
A structures monitoring inspection is performed on a 5-year frequency that includes all structures in the scope of the SQN 10 CFR 50.65 Maintenance Rule Program. During this inspection, a walkdown of the containment is performed looking for obvious degradation or the presence of aging mechanisms on visible/accessible portions of the Shield Building, containment interior concrete, and the SCV.
Inspections of the shield building interior and exterior are also performed under a preventative maintenance surveillance for Shield Building integrity verification. These inspections are performed on a 10-year frequency, and also serve to identify concrete aging mechanisms or degradation.
The Structures Monitoring Program addresses detection of aging effects for inaccessible and below-grade concrete structures in accordance with NUREG-1801, "Generic Aging Lessons Learned (GALL) Report," dated December 2010. The acceptability of inaccessible areas are evaluated when conditions exist in accessible areas that could indicate presence of, or result in, degradation to such inaccessible areas. Also, representative samples of the exposed portions of the below grade concrete are examined when excavated for any reason. TVA committed to revise the SQN Structures Monitoring Program Procedures prior to the Period of Extended Operation (PEO) to include: Opportunistic inspections when normally inaccessible areas (e.g., high radiation areas, below grade concrete walls or foundations, buried or submerged structures) become accessible due to required plant activities. Additionally, inspections will be performed of inaccessible areas in environments where observed conditions in accessible areas exposed to the same environment indicate that significant degradation is occurring," as stated in TVA Letter dated August 21, 2014, Enclosure 2, commitment number 31. There has been no abnormal degradation of the SQN Units 1 and 2 Shield Buildings/containment concrete detected by the above inspections that would indicate the potential for significant concrete degradation in inaccessible areas. The most recent inspections of the Shield Buildings were performed under CNL-15-171 Enclosure 1, Page 2 of 9
the maintenance rule structures inspection program during U1R18 and U2R18, for SQN Unit 1 and Unit 2, respectively.
RAI 3
Section 4.4.1 of the LAR provided information regarding the operating experience and examination of the moisture barrier at the junction of the containment vessel wall and the concrete floor. It is stated that (1) examinations were conducted in 2000, 2003, 2006, 2011, and 2014 for SQN, Unit 2, and in 2000, 2004, 2006, and 2012 for SQN, Unit 1; and (2) in each of the examinations, areas were noted where the moisture barrier was not completely adhered to the concrete interface. The moisture barrier was removed and reapplied in the subject areas.
Please provide the following:
- a. TVAs evaluation of the cause of degradation and specific details on TVAs corrective action(s) to demonstrate effective management of this identified degradation. The response should include details regarding (1) how the lack of bond between the moisture barrier and the respective surfaces at the junction of the concrete floor and the containment vessel wall was resolved; and (2) the effectiveness of the corrective action(s) considering that in each examination since 2000, areas were noted where the moisture barrier was not completely adhered to the concrete interface.
TVA Response Examinations of the moisture barrier have identified areas with lack of bonding of the sealant.
When these areas are identified, the sealant is excavated to allow inspection of the SCV under the moisture barrier and the condition is entered in the Corrective Action Program for evaluation.
Examinations have identified no instances of suspect areas or detrimental flaws that would affect the structural integrity of leak tightness of the SCV. After examination of the excavated areas, the sealant is reapplied and reexamined prior to the end of the outage. Because no instances of suspect areas or detrimental flaws have been identified, other corrective actions were not required as a result of these examinations.
- b. The LAR does not have specific details to determine whether the inspections covered both interior and exterior moisture barriers at the interface of the containment vessel wall and concrete.
TVA Response The moisture barrier is intended to prevent intrusion of moisture against inaccessible areas of the pressure retaining metal containment shell or liner at concrete to metal interfaces that are not seal welded. The moisture barrier is the sealant between the concrete to metal containment interface in the raceway behind the metal flashing. The raceway is an area inboard of the SCV between the Polar Crane Wall and the SCV on the bottom elevation of containment used for access to the accumulator rooms, fan rooms, and inside the polar crane wall. An examination of the moisture barrier is performed each inspection period. The flashing covering the moisture barrier is removed to allow access for examination.
The SCV to concrete interface is visible in the Annulus. The annulus is the area in the reactor building between the SCV and the concrete shield building. No moisture barrier covers the SCV to concrete interface in the Annulus. The metal to concrete interface is examined in the Annulus each inspection period. The following detail provides a representation of the internal and external SCV to concrete interface.
CNL-15-171 Enclosure 1, Page 3 of 9
CNL-15-171 Enclosure 1, Page 4 of 9
RAI 4
As stated in the LAR, the SQN in-service inspection program contains requirements to evaluate the acceptability of the inaccessible areas, if such conditions were identified, in accordance with 10 CFR 50.55a(b)(2)(ix)(A).
Please discuss areas, other than moisture barrier, of the SQN Units 1 and 2 containment vessels that are inaccessible and susceptible to degradation and provide information of instances where existence of or potential for degraded conditions in inaccessible areas were identified and evaluated based on conditions found in accessible areas, as required by 10 CFR 50.55a(b)(2)(ix)(A). As a minimum, the response should discuss the operating experience (1) where stainless steel sheet metal thermal barrier is covering approximately 5 feet of the bottom of the containment vessel wall, as depicted in Section A-A of Figure 3.8.2-7 of the SQN final safety analysis report; and (2) of the areas of the containment vessel that are inaccessible due to the ice condenser system configuration.
TVA Response The areas around inaccessible areas, including those inaccessible due to the ice condenser configuration, are examined and, to date, no areas have been identified that would indicate there is an issue that would adversely affect structural integrity or leak tightness of the SCV in inaccessible areas. Remote visual techniques are used, if possible, to eliminate inaccessibility.
A section of the stainless steel sheet metal thermal barrier is removed during moisture barrier examinations to allow access, and the accessible areas beneath the thermal barrier are examined. No problems have been identified during those examinations.
RAI 5
NRC Information Notice 2004-09 stated that:
Localized water ponding at the clogged drain, in the annulus area, had come in contact with a section of the steel containment vessel (SCV), causing deterioration of the SCV coatings and rusting of the SCV. This area of the SCV is restricted for access due to the close proximity between the SCV and the emergency gas treatment system (EGTS) duct work.
These [Corrective] actions consisted of the removal of the EGTS duct work on both Unit 1 and Unit 2 to allow the SCV area behind the EGTS duct work to be cleaned and recoated. Also the licensee has identified this SCV area behind the EGTS duct work for periodic visual examination.
Please provide information regarding the results of periodic examinations of this SCV area since discovery of the above referenced degradation.
TVA Response The examinations behind the EGTS duct work are performed every inspection period during the outboard SCV inspection in the Annulus. No new indications have been identified during these examinations since NRC Information Notice 2004-09 was issued.
CNL-15-171 Enclosure 1, Page 5 of 9
RAI 6
Section 4.0 of the LAR, in response to Condition 4 in Section 4.1 of the NRC safety evaluation (SE) for Topical Report NEI 94-01, Revision 2, dated June 25, 2008 (ADAMS Accession No. ML081140105), stated that SQN Units 1 and 2 have already replaced the steam generators and the design change process addressed the testing requirements.
In Section 4.1 of the LAR, it is noted that (1) the SQN Units 1 and 2 steam generators required temporary construction openings which were restored by reinstalling the removed steel sections and rewelding them using full penetration welds; and (2) the integrity of the restored vessel was verified by non-destructive examination (NDE) and leak testing of the welds.
In reference to Section 3.1.4 of the NRC safety evaluation for NEI 94-01, Revision 2, dated June 25, 2008, and to adequately address Condition 4 in Section 4.1 of the NRC safety evaluation, please provide the following:
a) The statement in the LAR regarding the integrity of the restored vessel being verified by NDE and leak testing of the welds is brief and gives the appearance that only a local leak rate test was performed. Please provide further information and confirm that all testing committed by TVA for alternative to the testing requirements in paragraph IWE-5221,Section XI of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code regarding post-repair pressure testing following SQN Units 1 and 2 steam generator replacements, as described in the NRC safety evaluations dated May 9, 2003 (ADAMS Accession No. ML031320320) and December 22, 2011 (ADAMS Accession No. ML11313A165) for SQN Units 1 and 2, respectively, were completed and all required acceptance criteria were satisfied.
TVA Response SQN, Unit 1 The NRC Safety Evaluation dated May 9, 2003, described the following testing.
x Magnetic particle test of the back gouge of the root pass x 100 percent radiography on the pressure boundary containment SCV final repair welds x Local leakage/pressure test of the SCV repair welds by pressurizing the containment vessel to the required test pressure of at least accident pressure (Pa) (per the SQN, Unit 1 Technical Specifications (TS) Pa is 12.0 pounds per square inch gauge (psig)) and performing a bubble test of the repair welds TVA confirms that the required testing was completed prior to returning the SQN, Unit 1 SCV to service and that the applicable acceptance criteria were met.
SQN, Unit 2 The NRC Safety Evaluation dated December 22, 2011, described the following testing.
x Magnetic particle testing of the weld preparation area before performing the weld repair x 100 percent radiography of the final repair weld x General visual examination of the SCV pressure boundary welds x VT-3 examination of the SCV pressure boundary welds x A detailed visual VT-1 examination of the SCV pressure boundary welds x Weld leak test by pressurizing the containment to a test pressure, Pa, of at least 12 psig for a minimum of 10 minutes and performing a bubble test of the repair welds CNL-15-171 Enclosure 1, Page 6 of 9
TVA confirms that the required testing was completed prior to returning the SQN, Unit 2 SCV to service and that the applicable acceptance criteria were met.
b) Information regarding examination of the new containment vessel dome welds that are currently implemented as part of the SQN containment in-service inspection.
TVA Response Two SCV cutouts were removed and replaced in each SQN Unit's SCV to allow access to the Steam Generators during the replacement outages.
Grid locations for Ultrasonic Testing (UT) thickness examinations have been selected. Each grid is 12 inches wide and 24 inches long, and they are spaced equally along the cut lines.
Areas with less than the calculated T minimum thickness will be evaluated. These exams are performed every other outage. The last performance of this examination on SQN, Unit 1 was in 2013 during refueling outage U1R19. No thickness readings were less than the T minimum thickness. The last performance of this examination for Unit 2 was in 2014 during refueling outage U2R19. One grid was found to be less than the T minimum thickness, and that grid was evaluated and found to be acceptable.
c) Confirmation that TVA will implement the staff position with regard to any future post-repair pressure testing following major and minor containment repairs and modifications, as explained in Section 3.1.4 of the NRC staff SE for NEI 94-01, Revision 2.
TVA Response TVA will implement the staff position with regard to any future post-repair pressure testing following major and minor SQN, Unit 1 and 2 containment repairs and modifications, as explained in Section 3.1.4 of the NRC staff SE for NEI 94-01, Revision 2. Specifically, TVA commits to revise NEDP-14, "Containment Leak Rate Programs," to incorporate the requirements of NEI 94-01, Revision 2, Section 3.1.4 for future post-repair pressure testing following major and minor SQN, Unit 1 and 2 containment repairs and modifications within 60 days of NRC approval of the License Amendment Request submitted December 2, 2014.
CNL-15-171 Enclosure 1, Page 7 of 9
RAI 7
In Section 4.2, Integrated Leak Rate Test History, page E1-8 of 27, of the submittal, there is a failure of the 4/28/92 as found leakage. The submittal states:
"A single penetration (X-47A) in the ice condenser glycol system was responsible for this failure. Corrective action was implemented to reduce the chance of recurrence."
Please explain how TVA met the criteria of NEI 94-01, Revision 3-A, Section 9.2.3 for two successful consecutive tests in order to be granted a Type A extension. What was the as-left leakage? What type of penetration is X-47A classified?
TVA Response Prior to the start of the April 28, 1992, Type A test, the valves associated with a single penetration (i.e., X-47A) in the ice condenser glycol system failed their as-found local leak rate tests (LLRTs). During the April 1, 1992, performance of the as-found Type C LLRTs of outboard containment barrier isolation valve FCV-61-191 and the associated inboard containment barriers FCV-61-192 and thermal relief check valve VLV-61-533, TVA discovered that both FCV-61-191 and FCV-61-192 (air operated diaphragm valves) failed to fully close. The FCV-61-191 leak rate was determined to be approximately 526.66 SCFH and the FCV-61-192/VLV-61-533 leak rate was determined to be approximately 211.19 SCFH. The resulting as-found minimum path leak rate was calculated as approximately 211.19 SCFH.
The FCVs were repaired and retested on April 2, 1992, with as-left results determined to be 0.00 SCFH for each valve.
At the time of the 1992 Type A test, the minimum path leakage savings (i.e., the difference between the as-found and the as-left leak rates) for all Type B and C tests was added to the Containment Integrated Leak Rate Test (CILRT) results, as described in NRC Information Notice 85-71, "Containment Integrated Leak Rate Tests," dated August 22, 1985. The 1992 Type A test was considered a failure due to addition of the leakage savings from penetration X-47A. In fact, the as-found minimum path leak rate for penetration X-47A of 211.1943 SCFH was greater than the CILRT acceptance criteria of 168.75 SCFH.
NEI 94-01, Revision 3-A, Section 5.0 defines the performance leakage rate as the sum of the Type A upper confidence limit (UCL) and as-left minimum pathway leakage rate (MNPLR) leakage rate for all Type B and Type C pathways that were in service, isolated, or not lined up in their test position (i.e., drained and vented to containment atmosphere) prior to performing the Type A test. In addition, leakage pathways that were isolated during performance of the test because of excessive leakage must be factored into the performance determination. The performance criterion for Type A tests is a performance leak rate of less than 1.0 La.
NEI 94-01, Revision 3-A, Section 9.1.1 also states that the allowable performance leakage rate is calculated as the sum of the Type A UCL and as-left MNPLR leakage rate for all Type B and Type C pathways that were in service, isolated, or not lined up in their test position (i.e., drained and vented to containment atmosphere) prior to performing the Type A test. In addition, leakage pathways that were isolated during performance of the test because of excessive leakage must be factored into the performance determination. If the leakage can be determined by a local leakage rate test, the as- left MNPLR for that leakage path must also be added to the Type A UCL. If the pathway leakage cannot be determined by local leakage rate testing, the performance criteria are not met.
The 1992 Type A test as-found Total Time Leak Rate (TTLR) without the leakage savings from X-47A was calculated at 0.15073%/ day and the as-found Mass Leak Rate (MLR) was CNL-15-171 Enclosure 1, Page 8 of 9
calculated at 0.05773%/ day which is less than 1.0 La (0.25%/day). Therefore, had the NEI 94-01, Revision 3 guidance been in place at the time of the April 28, 1992, Type A test, the test would not have been counted as a failure.
NEI 94-01, Revision 3-A, Section 9.2.3 defines acceptable performance history as successful completion of two consecutive periodic Type A tests where the calculated performance leakage rate was less than 1.0 La. Because the NEI 94-01, Revision 3-A, Section 9.1.1 method for calculating performance leakage rate does not require addition of leakage savings, the 1992 Type A test performance may be counted as one of the two successful consecutive tests to grant a frequency extension in accordance with NEI 94-01, Revision 3, Section 9.2.3.
CNL-15-171 Enclosure 1, Page 9 of 9
ENCLOSURE 2 TENNESSEE VALLEY AUTHORITY SEQUOYAH NUCLEAR PLANT UNITS 1 AND 2 List of Regulatory Commitments Revise NEDP-14, "Containment Leak Rate Programs," to incorporate the requirements of NEI 94-01, Revision 2, Section 3.1.4 for future post-repair pressure testing following major and minor SQN, Unit 1 and 2 containment repairs and modifications within 60 days of NRC approval of the License Amendment Request submitted December 2, 2014.
CNL-15-171 Enclosure 2, Page 1 of 1