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MONTHYEARML0232505162002-11-21021 November 2002 RAI, Bulletin 2002-01 60-Day Responses Project stage: RAI ML0300308632003-01-0303 January 2003 RAI, Licensee Identified Material Wastage Project stage: RAI ML0300704182003-01-14014 January 2003 Technical Assessment of Minor Reactor Vessel Head Material Wastage Project stage: Other ML0302805842003-01-27027 January 2003 Bulletin 2002-01, Reactor Pressure Vessel Head Degradation & Reactor Coolant Pressure Boundary Integrity, 15-Day Response for Sequoyah Nuclear Plant, Units 1 & 2 Project stage: Other ML0304204982003-02-0303 February 2003 Response to NRC Request for Additional Information Regarding Licensee Identified Material Wastage Project stage: Response to RAI ML0309703472003-03-26026 March 2003 Supplement to NRC Request for Additional Information Regarding Licensee Identified Material Wastage Project stage: Supplement 2003-01-27
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Category:Letter
MONTHYEARML24032A0202024-01-31031 January 2024 NPDES Biocide/Corrosion Treatment Plan Annual Report, Cy 2023 ML23319A2452024-01-29029 January 2024 Issuance of Amendment Nos. 366 and 360; 164 and 71 Regarding the Adoption of TSTF-567, Revision 1, Add Containment Sump TS to Address GSI-191 Issues CNL-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 ML24018A0142024-01-17017 January 2024 Engine Systems, Inc., Report No. 10CFR21-0137, Rev. 1, 56913-EN 56913 ML24011A3182024-01-11011 January 2024 Submittal of Discharge Monitoring Report (Dmr), October 2023 ML24011A3172024-01-11011 January 2024 Submittal of Discharge Monitoring Report (Dmr), September 2023 ML24011A3202024-01-11011 January 2024 Submittal of Discharge Monitoring Report (Dmr), December 2023 ML24011A3162024-01-11011 January 2024 Submittal of Discharge Monitoring Report (Dmr), August 2023 ML24011A3192024-01-11011 January 2024 Submittal of Discharge Monitoring Report (Dmr), November 2023 IR 05000327/20234422024-01-11011 January 2024 95001 Supplemental Inspection Report 05000327/2023442 and 05000328/2023442 and Follow-Up Assessment Letter ML24010A2132024-01-10010 January 2024 CFR 21.21 Final Report Regarding Siemens Medium Voltage Circuit Breakers ML24018A0952024-01-0404 January 2024 Engine Systems, Inc., 10CFR21 Reporting of Defects and Non-Compliance Report No. 10CFR21-0137, Rev. 0 ML24004A0332024-01-0303 January 2024 Interim Report of a Deviation or Failure to Comply Crompton Instruments Type 077 Ammeter ML24004A0402024-01-0303 January 2024 Response to NRCs November 8, 2023, Request for Additional Information - Related to Independent Spent Fuel Storage Installation 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) ML23346A1222023-12-12012 December 2023 Annual Non-Radiological Environmental Operating Report - 2023 IR 05000327/20234202023-11-28028 November 2023 Security Baseline Inspection Report 05000327/2023420 and 05000328/2023420 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 ML23324A4362023-11-0909 November 2023 Exam Corporate Notification Letter Aka 210-day Letter ML23307A0822023-11-0808 November 2023 Request for Additional Information August 4, 2022, Exemption Request for Deviating from the Conditions of Certificate of Compliance No. 1032, Amendment No. 3, Related to Sequoyah Nuclear Plant Independent Spent Fuel Storage Installation IR 05000327/20230032023-11-0303 November 2023 Integrated Inspection Report 05000327/2023003 and 05000328/2023003 ML23306A1592023-11-0202 November 2023 Enforcement Action EA-22-129 Inspection Readiness Notification ML23292A0792023-10-19019 October 2023 Tennessee Valley Authority - Emergency Plan Implementing Procedure Revision, Includes EPIP-5, Revision 58, General Emergency IR 05000327/20230112023-10-16016 October 2023 Triennial Fire Protection Inspection Report 05000327/2023011 and 05000328/2023011 ML23285A0882023-10-12012 October 2023 Submittal of Sequoyah Nuclear Plant, Units 1 and 2, Submittal of Updated Final Safety Analysis Report Amendment 31 ML23284A4252023-10-11011 October 2023 10 CFR 50.59 and 10 CFR 72.48 Changes, Tests, and Experiments Summary Report; Commitment Summary Report; and Update to the Fire Protection Report ML23283A2792023-10-10010 October 2023 Revisions to the Sequoyah Nuclear Plant Units 1 and 2 Technical Requirements Manual ML23279A0612023-10-0505 October 2023 Paragon Energy Solutions LLC, Part 21 Final Report Re Potential Defect with Eaton Jd and Hjd Series Molded Case Circuit Breakers (Mccbs) ML23277A0462023-10-0404 October 2023 Revisions to the Sequoyah Nuclear Plant Units 1 and 2 Technical Specification Bases ML23275A0272023-09-29029 September 2023 Submittal of Discharge Monitoring Report (DMR) Quality Assurance Study 43 Final Report 2023 ML23271A1662023-09-28028 September 2023 Registration of Spent Fuel Storage Cask Pursuant to 10 CFR 72.212(b)(2) 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-23-061, 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 IR 05000327/20234032023-09-14014 September 2023 Cyber Security Inspection Report 05000327/2023403 and 05000328/2023403 (Cover Letter) ML23257A0062023-09-14014 September 2023 Enforcement Action EA-22-129 Inspection Postponement Request ML23254A2192023-09-11011 September 2023 Emergency Plan Implementing Procedure Revisions ML23254A0652023-09-0707 September 2023 Registration of Spent Fuel Storage Cask Pursuant to 10 CFR 72.212(b)(2) 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 IR 05000327/20230052023-08-29029 August 2023 Updated Inspection Plan for Sequoyah Nuclear Plant, Units 1 and 2 - Report 05000327/2023005 and 05000328/2023005 ML23233A0122023-08-17017 August 2023 Unit 1 Cycle 25 Refueling Outage - 90-Day Inservice Inspection Summary Report - Supplement ML23233A0142023-08-15015 August 2023 Discharge Monitoring Report (Dmr), July 2023 ML23215A1212023-08-0303 August 2023 301 Exam Administrative Items (2B) Normal Release ML23215A1572023-08-0303 August 2023 Enforcement Action EA-22-129 Inspection Readiness Notification 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) ML23192A4472023-07-31031 July 2023 Staff Assessment of Updated Seismic Hazards at TVA Sites Following the NRC Process for the Ongoing Assessment of Natural Hazards Information 2024-01-04
[Table view] Category:Report
MONTHYEARML23284A4252023-10-11011 October 2023 10 CFR 50.59 and 10 CFR 72.48 Changes, Tests, and Experiments Summary Report; Commitment Summary Report; and Update to the Fire Protection Report ML23192A4472023-07-31031 July 2023 Staff Assessment of Updated Seismic Hazards at TVA Sites Following the NRC Process for the Ongoing Assessment of Natural Hazards Information ML21246A2802021-09-29029 September 2021 Final Ea/Fonsi for Tva'S Initial and Updated Triennial Decommissioning Funding Plans for Sequoyah Nuclear Plant ISFSIs IR 05000327/20210052021-08-18018 August 2021 Updated Inspection Plan for Sequoyah Nuclear Plant, Units 1 and 2 Report 05000327/2021005 and 05000328/2021005 CNL-21-072, TVA Nuclear Calculation Coversheet/ Ecm Metadata Update2021-08-13013 August 2021 TVA Nuclear Calculation Coversheet/ Ecm Metadata Update ML21140A0282021-05-14014 May 2021 Gravel Lot Restoration Project, Construction General Permit, Notice of Intent CNL-20-102, 10 CFR 71.95 Report for 3-60B Casks User2020-12-16016 December 2020 10 CFR 71.95 Report for 3-60B Casks User ML20350B7202020-12-15015 December 2020 Discharge Monitoring Report Quality Assurance Study 40 Final Report 2020 ML20308A4762020-11-0202 November 2020 10 CFR 50.59 and 10 CFR 72.48 Changes, Tests, and Experiments Summary Report and Commitment Summary Report ML20304A4032020-10-28028 October 2020 Revisions to the Sequoyah Nuclear Plant Units 1 and 2 Technical Requirements Manual ML19156A2612019-06-0505 June 2019 10 CFR 50.59 and 10 CFR 72.48 Changes, Tests, and Experiments Summary Report and Commitment Summary Report ML18352A2292018-12-17017 December 2018 Pressure Temperature Limits Report, Revision 7 ML18340A0302018-11-30030 November 2018 Tennessee Valley Authority - Sequoyah, Study to Confirm Calibration of Numerical Model ML18136A4952018-05-15015 May 2018 Pressure Temperature Limits Report, Revision 6 ML18061A0362018-03-0202 March 2018 IAEA Report of the Operational Safety Review Team (Osart) Mission to the Sequoyah Nuclear Power Plant ML17278A7592017-10-0505 October 2017 Soarca Sequoyah Updated Draft Executive Summary ML15336A9402015-11-26026 November 2015 Submittal of 10 CFR 50.46 Combined Annual and 30-Day Report ML15321A4542015-11-13013 November 2015 Submittal of 10 CFR 71.95 Report on the 8-120B Cask CNL-15-143, the Tennessee Valley Authority (TVA) Nuclear Power Group Commercial Grade Dedication Recovery Project - Closure Report2015-07-31031 July 2015 the Tennessee Valley Authority (TVA) Nuclear Power Group Commercial Grade Dedication Recovery Project - Closure Report CNL-15-106, 3, Sequoyah and Watts Bar, Units 1 & 2 - Provides Service List Update for Routine Information2015-07-0808 July 2015 3, Sequoyah and Watts Bar, Units 1 & 2 - Provides Service List Update for Routine Information ML15156A3892015-04-28028 April 2015 LTR-SGMP-15-25 Np, Response to NRC Request for Additional Information on the Design Features of the Sequoyah, Unit 2, Replacement Steam Generators. ML14325A0692014-11-17017 November 2014 CFR 50.59 and 10 CFR 72.48 Changes, Tests, and Experiments Summary Report ML14283A5132014-11-17017 November 2014 NRC Staff Review Documentation Provided by TVA for the Sequoyah Nuclear Plant, Units 1 and 2 Concerning Resolution of GL2004-02 Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurizer-Wate ML14259A3382014-09-12012 September 2014 Plant(Sqn) - NPDES Permit No. TN0026450 - Discharge Monitoring Report(Dmr) for August 2014 CNL-14-130, Third Six-Month Status Report in Response to the March 12, 2012, Commission Order Modifying Licenses with Regard to Reliable Spent Fuel Pool Instrumentation (Order Number EA-12-051) for Sequoyah Nuclear Plant2014-08-28028 August 2014 Third Six-Month Status Report in Response to the March 12, 2012, Commission Order Modifying Licenses with Regard to Reliable Spent Fuel Pool Instrumentation (Order Number EA-12-051) for Sequoyah Nuclear Plant CNL-14-038, Tennessee Valley Authority'S Seismic Hazard & Screening Report (CEUS Sites), Response to NRC Request for Information Pursuant to 10 CFR 50.54(f) Recommendation 2.1 of Near-Term Task Force Review of Insights from the Fukushima Dai-ichi Acc2014-03-31031 March 2014 Tennessee Valley Authority'S Seismic Hazard & Screening Report (CEUS Sites), Response to NRC Request for Information Pursuant to 10 CFR 50.54(f) Recommendation 2.1 of Near-Term Task Force Review of Insights from the Fukushima Dai-ichi Accid CNL-14-033, Second Six-Month Status Report and Revised Overall Integrated Plan in Response to March 12, 2012 Commission Order Modifying Licenses Re Requirements for Mitigation Strategies for Beyond-Design-Basis External Events2014-03-0505 March 2014 Second Six-Month Status Report and Revised Overall Integrated Plan in Response to March 12, 2012 Commission Order Modifying Licenses Re Requirements for Mitigation Strategies for Beyond-Design-Basis External Events ML14063A5422014-03-0404 March 2014 TVA Response to Request for Clarification to NRC Request for Additional Information Regarding the Review of the Sequoyah Nuclear Plant, Units 1 and 2, License Renewal Application, LRA B.1.31, B.1.25.1 B, B.1.34-Sa, B.1.34-9a, LRA Annual ... ML14002A1132014-02-19019 February 2014 Interim Staff Evaluation Relating to Overall Integrated Plan in Response to Order EA-12-049 (Mitigation Strategies) ML14041A1922014-02-16016 February 2014 Mega-Tech Services, LLC Technical Evaluation Report Regarding the Overall Integrated Plan for Sequoyah Nuclear Plant, Units 1 and 2, TAC Nos.: MF0864 and MF0865 ML14016A0392014-02-0606 February 2014 Staff Assessment of the Seismic Walkdown Report Supporting Implementation of Near-Term Task Force Recommendation 2.3 Related to the Fukushima Dai-Ichi Nuclear Power Plant Accident CNL-14-013, Highlights of Improvements to the Sequoyah Nuclear Plant IPEEE Seismic Analysis Results and Supplemental Response to NRC Request for Information Pursuant to Title 10 of the Code of Federal Regulations 50.54(f)Regarding...2014-01-31031 January 2014 Highlights of Improvements to the Sequoyah Nuclear Plant IPEEE Seismic Analysis Results and Supplemental Response to NRC Request for Information Pursuant to Title 10 of the Code of Federal Regulations 50.54(f)Regarding... CNL-13-117, 10 CFR 50.46 - Combined Annual and 30-Day Report2013-11-18018 November 2013 10 CFR 50.46 - Combined Annual and 30-Day Report ML13298A0312013-10-22022 October 2013 SQN Femp Energy and Ghg Reporting Tool: Results Summary Fy 2008 - Fy 2012 Listed in Letter from TVA, Dated Sep 20, 2013, in Response to RAI 6.a.i.9 (7 Pages) ML13294A4302013-09-26026 September 2013 Fukushima Near-Term Task Force Recommendation 2.3: Seismic Response Report, Revision 1 ML13282A2332013-09-26026 September 2013 Fukushima Near-Term Task Force Recommendation 2.3: Seismic Response Report ML13206A0042013-06-24024 June 2013 Methodology for Evaluating the Potential for Multiple Dam Failures Due to Seismic Events ML13144A5762013-05-22022 May 2013 Watt Bar, Units 1 & 2, Report of Drug Testing Error in Accordance with 10 CFR 26.719(c)(1) ML13142A1982013-05-16016 May 2013 Path Forward for Resolution of Generic Safety Issue (GSI)-191 ML13080A0732013-03-12012 March 2013 Extension Request Regarding the Flooding Hazard Reevaluation Report Required by NRC Request for Information Pursuant to Title 10 of the Code of Federal Regulations 50.54(f) Regarding Recommendation.. ML13072A5802013-03-0505 March 2013 Storm Water Pollution Prevention Plan ML13032A2532013-01-10010 January 2013 WCAP-17539-NP, Revision 0, Sequoyah, Units 1 and 2 Time-Limited Aging Analysis on Reactor Vessel Integrity ML12335A3402012-11-27027 November 2012 Tennessee Valley Authority - Fleet Response to NRC Request for Information Pursuant to Title 10 of the Code of Federal Regulations 50.54(f) Regarding the Flooding Walkdown Results of Recommendation 2.3 of the Near-Term Task Force Review of ML12240A1742012-09-18018 September 2012 Review of the 2011 Refueling Outage Steam Generator Tube Inservice Inspection Reports ML1218500102012-06-30030 June 2012 Enclosure 2, Tennessee Valley Authority Sequoyah Nuclear Plant Units 1 and 2 - ANP-3053(NP), Revision 4, Sequoyah Htp Fuel Transition - NRC RAIs and Responses, June 2012 (Non-Proprietary Version) ML12153A3782012-05-31031 May 2012 Enclosure 2, Sequoyah Nuclear Plant, Units 1 & 2 - ANP-3053 (Np), Revision 3, Sequoyah Htp Fuel Transition - NRC RAIs and Responses ML12137A2982012-05-15015 May 2012 ANP-2970Q2(NP), Rev 0, Sequoyah, Units 1 and 2 Htp Fuel Realistic Large Break LOCA Analysis ML12118A1662012-04-26026 April 2012 ANP-2970Q1(NP), Revision 000, Htp Fuel Realistic Large Break LOCA Analysis, April 2012 (Non-Proprietary Version), Enclosure 2 ML12114A0612012-04-0505 April 2012 Technical Report, SQN2-SGR-TRI, Revision 3, Sequoyah Unit 2 Steam Generator Replacement Rigging and Heavy Load Handling. ML12088A1712012-03-31031 March 2012 ANP-3053(NP), Revision 2, Sequoyah Htp Fuel Transition - NRC RAIs and Responses, March 2012 (Non-Proprietary Version), Enclosure 2 2023-07-31
[Table view] Category:Technical
MONTHYEARML23192A4472023-07-31031 July 2023 Staff Assessment of Updated Seismic Hazards at TVA Sites Following the NRC Process for the Ongoing Assessment of Natural Hazards Information CNL-21-072, TVA Nuclear Calculation Coversheet/ Ecm Metadata Update2021-08-13013 August 2021 TVA Nuclear Calculation Coversheet/ Ecm Metadata Update ML21140A0282021-05-14014 May 2021 Gravel Lot Restoration Project, Construction General Permit, Notice of Intent CNL-20-102, 10 CFR 71.95 Report for 3-60B Casks User2020-12-16016 December 2020 10 CFR 71.95 Report for 3-60B Casks User ML20350B7202020-12-15015 December 2020 Discharge Monitoring Report Quality Assurance Study 40 Final Report 2020 ML20308A4762020-11-0202 November 2020 10 CFR 50.59 and 10 CFR 72.48 Changes, Tests, and Experiments Summary Report and Commitment Summary Report ML20304A4032020-10-28028 October 2020 Revisions to the Sequoyah Nuclear Plant Units 1 and 2 Technical Requirements Manual ML18352A2292018-12-17017 December 2018 Pressure Temperature Limits Report, Revision 7 ML18340A0302018-11-30030 November 2018 Tennessee Valley Authority - Sequoyah, Study to Confirm Calibration of Numerical Model ML18136A4952018-05-15015 May 2018 Pressure Temperature Limits Report, Revision 6 ML18061A0362018-03-0202 March 2018 IAEA Report of the Operational Safety Review Team (Osart) Mission to the Sequoyah Nuclear Power Plant CNL-15-143, the Tennessee Valley Authority (TVA) Nuclear Power Group Commercial Grade Dedication Recovery Project - Closure Report2015-07-31031 July 2015 the Tennessee Valley Authority (TVA) Nuclear Power Group Commercial Grade Dedication Recovery Project - Closure Report ML14283A5132014-11-17017 November 2014 NRC Staff Review Documentation Provided by TVA for the Sequoyah Nuclear Plant, Units 1 and 2 Concerning Resolution of GL2004-02 Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurizer-Wate CNL-14-038, Tennessee Valley Authority'S Seismic Hazard & Screening Report (CEUS Sites), Response to NRC Request for Information Pursuant to 10 CFR 50.54(f) Recommendation 2.1 of Near-Term Task Force Review of Insights from the Fukushima Dai-ichi Acc2014-03-31031 March 2014 Tennessee Valley Authority'S Seismic Hazard & Screening Report (CEUS Sites), Response to NRC Request for Information Pursuant to 10 CFR 50.54(f) Recommendation 2.1 of Near-Term Task Force Review of Insights from the Fukushima Dai-ichi Accid ML14063A5422014-03-0404 March 2014 TVA Response to Request for Clarification to NRC Request for Additional Information Regarding the Review of the Sequoyah Nuclear Plant, Units 1 and 2, License Renewal Application, LRA B.1.31, B.1.25.1 B, B.1.34-Sa, B.1.34-9a, LRA Annual ... ML14002A1132014-02-19019 February 2014 Interim Staff Evaluation Relating to Overall Integrated Plan in Response to Order EA-12-049 (Mitigation Strategies) ML14041A1922014-02-16016 February 2014 Mega-Tech Services, LLC Technical Evaluation Report Regarding the Overall Integrated Plan for Sequoyah Nuclear Plant, Units 1 and 2, TAC Nos.: MF0864 and MF0865 ML13282A2332013-09-26026 September 2013 Fukushima Near-Term Task Force Recommendation 2.3: Seismic Response Report ML13206A0042013-06-24024 June 2013 Methodology for Evaluating the Potential for Multiple Dam Failures Due to Seismic Events ML13142A1982013-05-16016 May 2013 Path Forward for Resolution of Generic Safety Issue (GSI)-191 ML13072A5802013-03-0505 March 2013 Storm Water Pollution Prevention Plan ML13032A2532013-01-10010 January 2013 WCAP-17539-NP, Revision 0, Sequoyah, Units 1 and 2 Time-Limited Aging Analysis on Reactor Vessel Integrity ML1218500102012-06-30030 June 2012 Enclosure 2, Tennessee Valley Authority Sequoyah Nuclear Plant Units 1 and 2 - ANP-3053(NP), Revision 4, Sequoyah Htp Fuel Transition - NRC RAIs and Responses, June 2012 (Non-Proprietary Version) ML12153A3782012-05-31031 May 2012 Enclosure 2, Sequoyah Nuclear Plant, Units 1 & 2 - ANP-3053 (Np), Revision 3, Sequoyah Htp Fuel Transition - NRC RAIs and Responses ML12137A2982012-05-15015 May 2012 ANP-2970Q2(NP), Rev 0, Sequoyah, Units 1 and 2 Htp Fuel Realistic Large Break LOCA Analysis ML12118A1662012-04-26026 April 2012 ANP-2970Q1(NP), Revision 000, Htp Fuel Realistic Large Break LOCA Analysis, April 2012 (Non-Proprietary Version), Enclosure 2 ML12114A0612012-04-0505 April 2012 Technical Report, SQN2-SGR-TRI, Revision 3, Sequoyah Unit 2 Steam Generator Replacement Rigging and Heavy Load Handling. ML12088A1712012-03-31031 March 2012 ANP-3053(NP), Revision 2, Sequoyah Htp Fuel Transition - NRC RAIs and Responses, March 2012 (Non-Proprietary Version), Enclosure 2 ML11266A1582011-09-16016 September 2011 C17 Voltage-Based ARC 90-Day Report ML11266A1592011-09-16016 September 2011 Areva Np, Inc., Sequoyah 2C17 W-Star 90-Day Report ML11210B5322011-07-31031 July 2011 ANP-2986(NP), Revision 3, Sequoyah Htp Fuel Transition. Attachment 2 ML11172A0702011-06-30030 June 2011 ANP-2986(NP), Revision 2, Sequoyah Htp Fuel Transition, Attachment 8 ML11172A0722011-05-31031 May 2011 ANP-2971(NP), Rev 1, Sequoyah Units 1 and 2 Htp Fuel S-RELAP5 Small Break LOCA Analysis, Attachment 9 ML11172A0642011-04-30030 April 2011 ANP-2970(NP), Rev 0, Sequoyah, Units 1 and 2 Htp Fuel Realistic Large Break LOCA Analysis, Attachment 10 ML11116A2112011-04-21021 April 2011 Technical Report No. SQN2-SGR-TR3, Revision 0 Sequoyah Unit 2 Steam Generator Replacement Alternate Rebar Splice - Bar-Lock Mechanical Splices Technical Report, Attachment 2 ML1005507732010-01-31031 January 2010 SG-SGMP-10-2, Condition Monitoring and Operational Assessment: GL-95-05 Alternate Repair Criterion End of Cycle 16 - 90 Day Report, Enclosure 1 ML1108310412009-05-31031 May 2009 Engineering Evaluation of Hesco Barriers Performance at Fargo, Nd 2009, Wenck File 2283-01, Enclosure 2 ML0904007952009-02-0404 February 2009 GSI-189 Action Plan, Feb. 09 Update, Publicly Available Version ML0821900132008-08-0707 August 2008 Monthly Operating Reports Second Quarter 2008 ML0824806912008-07-31031 July 2008 SG-CDME-08-24, Revision 0, Condition Monitoring and Operational Assessment: GL-95-05 Alternate Repair Criterion End of Cycle 15 90 Day Report, Sequoyah Unit 2. ML0810803382008-02-29029 February 2008 ANP-2695(NP), Rev 0, Enclosure 3, Sequoyah Nuclear Plant Unit 1, Realistic Large Break Loss of Coolant Accident Analysis ML0734000922007-11-30030 November 2007 Rev. 2 to SG-CDME-07-7, Condition Monitoring and Operational Assessment: GL-95-05 Alternate Repair Criterion End of Cycle 14, 90 Day Report for Sequoyah Unit 2. ML0732400482007-09-30030 September 2007 Rev. 0 to SG-CDME-07-21-NP, Examination of a Steam Generator Tube Removed from Sequoyah Unit 2. ML0711602272007-04-24024 April 2007 Staff Technical Evaluation Report, 06-03 ML0523405032005-08-15015 August 2005 Unit 2 Cycle 13 (U2C13) 90-Day Steam Generator (S/G) Report for Voltage-Based Alternate Repair Criteria and W* Alternate Repair Criteria ML11307A4202005-04-30030 April 2005 Enclosure 2 - Wenck Associates, Inc., Engineering Evaluation of Hesco Barriers Performance at Fargo, Nd 2009, May 2009 ML1108310422005-04-30030 April 2005 Texas Transportation Institute, DOS K12 Crash Test and Evaluation of the Hesco C-3315 Flood Barrier, April 2005, Enclosure 3 ML0410506212004-04-12012 April 2004 Diffuser Line Manhole Breach ML0409104172004-03-18018 March 2004 TRC Studies, EPA Information, Bmp Plan, Biodetergent 73551 ML0402106382003-12-0202 December 2003 November 2003 - Discharge Monitoring Report 2023-07-31
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Tennessee Valley Authority, Post Office Box 2000, Soddy-Datsy, Tennessee 37384-2000 February 3, 2003 U.S. Nuclear Regu~atory Commission ATTN: Document Control Desk Washington, D. C.120555 Gentlemen:
In the Matter of ) Docket No. 50-328 Tennessee Valley Authority SEQUOYAH NUCLEAR PLANT (SQN) - UNIT 2 - RESPONSE TO NRC REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSEE IDENTIFIED MATERIAL WASTAGE (TAC NO. MB4579)
Reference:
NRC letter to TVA dated January 3, 2003, Sequoyah Nuclear Plant Unit 2 - Request for Additional Information Concerning Licensee Identified Material Wastage (TAC NO. MB4579)
The purpose of this submittal is to provide additional information in response to the staff's referenced letter.
Based on discussion with the staff during a conference call on January 3, 2002, TVA is providing the requested information to allow the staff to complete their review of the inspection results for SQN Unit 2. provides additional information in response to staff's letter of request. Enclosure 2 provides photographs from the Unit 2 reactor vessel head inspection. Enclosure 3 provides schematic drawings of the reactor vessel. Enclosure 4 provides the unidentified leakage trend history for Unit 2.
Printed on recycled paper
U.S. Nuclear Regulatory Commission Page 2 February 3, 2003 This letter is being sent in accordance with NRC RIS 2001-05.
There are no commitments contained in this letter.
If you have any questions about this change, please telephone me at (423) 843-7170 or J. D. Smith at (423) 843-6672.
nsing and Industry Affairs Manager Enclosures cc (Enclosures)
Mr. Raj K. Anand, Senior Project Manager U.S. Nuclear Regulatory Commission MS 0-8G9 One White Flint North 11555 Rockville Pike Rockville, Maryland 20852-2739
ENCLOSURE 1 TENNESSEE VALLEY AUTHORITY SEQUOYAH NUCLEAR PLANT (SQN)
UNIT 2 DOCKET NO. 328 ADDITIONAL INFORMATION REGARDING LICENSEE IDENTIFIED MATERIAL WASTAGE NRC Question No. 1 There are apparently two leak sources: (1) through a reactor vessel level indication system (RVLIS) mechanical joint and (2) through a conoseal or canopy seal control rod drive mechanism penetration. What was the impact of these two separate leakage sources (i.e., what was the extent of the degradation)? How long have there been leaks from these two sources and how was that determined?
TVA Response There were two leaks discovered as part of the head inspection found during the recent Unit 2 forced outage. These were the reactor vessel level instrumentation system (RVLIS) mechanical joint and a canopy seal leak at location J-11.
- 1. The RVLIS joint leak was the predominate contributor to the increase in radioactivity in containment. The RVLIS mechanical joint leak was at a compression fitting joint which is disconnected each outage to facilitate head removal. This joint sprayed onto the side of the control rod drive ventilation shroud and down onto the insulation that covers the reactor vessel flange bolting. The borated water then followed the insulation seam joint and dripped down onto the vessel head resulting in some wastage of the alloy steel (Mg Mo) vessel head. The area of wastage is approximately 5 inches long, 1/2 inch wide and 1/8 inch deep.
- 2. The canopy seal leak at J-1l was minor and the dried boron residue traces did not reach the reactor vessel head, as confirmed by inspection using a video probe.
In August 2002 containment radioactivity trended upward at the same time a fuel assembly leak was identified. Based on trending it was conservatively decided that a reactor coolant system (RCS) leak existed in containment from start up of the May 2002 Unit 2 refueling outage. The unidentified leak rate trending data shows E1-I
that the leak was small, (less than 0.1 gpm) consistent with data scatter in the lower level of detection range.
NRC Question No. 2 It was communicated that degradation on the upper head is somewhat groove-like, about 5-inches long, and 1/8-inch deep.
This morphology is not typical for wastage caused by boric acid; please provide more details to describe the morphology of the degradation. Is the extent of the degradation consistent with TVA's expectations with respect to head temperatures, exposure time, etc.?
TVA Response As the water dripped through the insulation onto the reactor vessel head, it migrated down the head curvature and evaporated shortly after contact with the reactor vessel head (approximate operating temperature of 550 0 F). The temperature of the air at the insulation and control rod drive (CRD) shroud area where the leak spread is approximately 115°F to 135 0 F.
The morphology of the wastage area described in the TVA response to question 1 is consistent with EPRI tests where boric acid is dripped on a 600°F heated surface (Reference Boric Acid Corrosion Guidebook, Revision 1 - Test Reference EPRI-5). The corrosion is described as consisting of narrow troughs that coincide with the edges of the boric acid flow lines. The wastage rates associated with this test ranged from 1.2 to 1.9 inches/year.
Concentrated boric acid at approximately 212°F - 220'F is the point of maximum corrosion rate. However, if the metal surfaces are hot and the leakage rate very low, the solution can boil off quickly, leaving dry boric acid crystals that cause essentially no corrosion. (Reference Boric Acid Guidebook Revision 1 Section 4.10.)
Considering the amount of wastage and the assumption that the RVLIS leak occurred shortly after start up, the amount of wastage is indicative of a corrosion rate of 0.02 inches/month.
NRC Question No. 3 What is the trend of reactor coolant system (RCS) unidentified leakage since the last refueling outage and how well does the amount of boron recovered correlate to the known trend of RCS unidentified leakage? What is the location of insulation seams in the vicinity of this degradation? What is the distance between the leaking RVLIS mechanical joint and the top of the EI-2
reactor vessel head? What is the approximate temperature of this joint with respect to ventilation in the area and the leak path for the leaking RCS fluid given ventilation in the area.
TVA Response Unit 2 unidentified leakage noted since startup following the May 2002 refueling outage has been low (see enclosure 3 and the information in TVA' s response to NRC Question 1).
As can be seen from the enclosed photographs (see enclosure 2),
the RVLIS connection protrudes through the CRD shroud above the insulation over the vessel flange bolting. The RVLIS leak resulted in a spray pattern on the vertical insulation. The process fluid that remained in liquid form then progressed to the insulation seam joint and dripped on the reactor vessel head.
The distance from the RVLIS mechanical joint to the reactor vessel head is approximately 4 feet.
The temperature of the air at the insulation and CRD shroud area where the leak spread is about 115*F to 135 0 F.
NRC Question No. 4.
Explain why the Westinghouse fatigue evaluation focuses on one additional startup and shutdown cycle.
TVA Response The Westinghouse fatigue evaluation was originally prepared with minimal information regarding the material loss on the reactor head. Subsequently, Westinghouse included in its evaluation, allowances for sharp corners which increased the stress concentration factors and affected the fatigue life of the reactor head. As a result Westinghouse included conservative operational restrictions on the number of heatup and cooldown cycles and recommended blending any sharp edges in the depressed area.
Further visual examination indicated there were no abrupt corners. This provided the basis for the relaxation of any operational restrictions and the removal of the recommendation to blend the area. The text regarding sharp edges was left in the evaluation to stress the importance of removing any sharp edges.
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NRC Question No. 5 How was the extent of the degradation evaluated? For example, it looks like some borated water could have contacted the RV flange bolts. How was this assessed if the bolts were not removed for inspection?
TVA Response Extent of condition associated with the RVLIS mechanical joint leak was evaluated by a visual inspection of the exposed reactor vessel flange and flange bolting. The original visual inspection documented the extent and appearance of boric acid deposits. The affected portion of the head, flange and accessible bolt threads were visually inspected for material condition. The boric acid in the flange area was dry and loose with no signs of active corrosion that would have affected the bolting.
The canopy seal weld leak at Jll and other accessible canopy seals were inspected using a video probe through two inspection ports in the CRD shroud. In addition, the areas under the insulation at J-1l were inspected with a video probe to verify that no boron traveled onto the reactor head.
NRC Question No. 6 What caused Tennessee Valley Authority to inspect the RV head?
Was there a licensing commitment, TS requirement, or some other vehicle that cased them to inspect? What was the amount of unidentified leakage at the time of shutdown? When was the last time TVA inspected the head and what did the inspection consist of (e.g., bare metal visual)? What would have been the consequences had the inspections not been performed, the borated water leakage identified, corrected, and cleaned up?
TVA Response Proactive measures taken at the onset of the forced outage included inspections of lower containment and the pressurizer compartment looking for potential leakage. Inspection of the reactor vessel head was a result of conservative management decision making which took into account the trend of containment activity data and the fact that two different inspection teams did not find a leak that could account for the activity being seen.
A 100 percent bare metal visual inspection of the reactor vessel head was performed in the May 2002 Unit 2 refueling outage. TVA has committed to follow the MRP plan for head inspections in addition to the ASME Section XI required examinations.
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If the leak had not been found during this forced outage and operation continued until the October 2003 refueling outage, some additional wastage of the reactor vessel head would have occurred. Given the limited data available, however, we do not believe that it is possible to arrive at any credible estimate of additional leakage consequences.
The leak would have been discovered during the refueling outage when the insulation and RVLIS connection are removed as part of the vessel disassembly. Borated water inspections of the accessible head and canopy seal welds performed as a scheduled refueling outage activity would have identified and evaluated any degradation at this particular location.
NRC Question No. 7 What was the root cause for leakage occurring in the RVLIS mechanical fitting and how will you confirm that there will not be any additional leaks of this nature?
TVA Response At this time TVA is conducting a root cause analysis. Following completion, TVA plans to submit the results of the analysis.
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ENCLOSURE 2 TENNESSEE VALLEY AUTHORITY SEQUOYAH NUCLEAR PLANT (SQN)
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ENCLOSURE 3 TENNESSEE VALLEY AUTHORITY SEQUOYAH NUCLEAR PLANT (SQN)
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ENCLOSURE 4 TENNESSEE VALLEY AUTHORITY SEQUOYAH NUCLEAR PLANT (SQN)
UNIT 2 DOCKET NO. 328 UNIDENTIFIED LEAKAGE TREND HISTORY
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