Letter Sequence RAI |
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Initiation
- Request, Request, Request, Request, Request, Request
- Acceptance
- Supplement, Supplement, Supplement, Supplement, Supplement, Supplement, Supplement
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MONTHYEARML0630602512003-10-15015 October 2003 WB1-DWD-015A, Containment Debris Walkdown Package Watts Bar N. P. Unit 1. Project stage: Other ML0629105222003-11-0505 November 2003 WB1-DWD-024A, Containment Debris Walkdown Package Watts Bar N. P. Unit 1. Project stage: Other ML0629105132004-08-24024 August 2004 TVAW001-RPT-001, Rev. 0, Report on Watts Bar, Unit 1 Containment Building Walkdowns for Emergency Sump Strainer Issues. Project stage: Other ML0515205802005-06-0303 June 2005 Request for Additional Information Related to Generic Letter 2004-02, Potential Impact of Debris Blockage on Emergency Sump Recirculation at Pressurized-water Reactors Project stage: RAI ML0603800822006-02-10010 February 2006 RAI, Response to GL-2004-02, Potential Impact of Debris Blockage on Emergency Recirculation During Design-Basis Accidents at Pressurized-water Reactors Project stage: RAI ML0610402192006-04-11011 April 2006 Generic Letter 2004-02 - Potential Impact of Debris Blockage on Emergency Recirculation During Design-Basis Accidents at Pressurized Water Reactors - Response to Request for Additional Information Project stage: Response to RAI ML0610101802006-05-10010 May 2006 Request for Additional Info the Nuclear Regulatory Commission Staff Audit on the Containment Sump Modification Project stage: Acceptance Review ML0629105082006-07-0303 July 2006 Generic Letter 2004-02 - Request for Additional Information Regarding NRC Staff Audit on Containment Sump Modifications Project stage: Request ML0621204722006-07-0303 July 2006 Watts Bar Nuclear Plant (WBN) Unit 1 - Generic Letter 2004-02 - Request for Additional Information Regarding the Nuclear Regulatory Commission Staff Audit on the Containment Sump Modifications Project stage: Request ML0621800772006-08-11011 August 2006 Proprietary Letter, Request for Withholding Information from Public Disclosure, Containment Sump Modifications Project stage: Withholding Request Acceptance ML0721501092007-08-0101 August 2007 Generic Letter 2004-02 - Potential Impact of Debris Blockage on Emergency Recirculation During Design-Basis Accidents at Pressurized Water Reactors - Request for Extension of Completion Date for Corrective Actions Project stage: Request ML0727604492007-10-0202 October 2007 Watts Bar Nuclear Plant (WBN) Unit 1, Generic Letter 2004-02, Recirculation During Design-Basis Accidents at Pressurized Water Reactors - Request for Extension of Completion Date for Corrective Actions Project stage: Request ML0733801522007-12-0606 December 2007 Generic Letter 2004-02 Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized Water Reactors Extension Request Evaluation Project stage: Other ML0810905032008-03-31031 March 2008 Enclosure 1, Supplemental Response Addressing GL-04-002 Actions, Calculation No. PCI-5464-S01, Rev. 2, Attachments a and B, Page 384 of 680 Project stage: Supplement ML0810905012008-03-31031 March 2008 Enclosure 1, Supplemental Response Addressing GL-04-002 Actions, Pages E1-1 Through Figure 4.24 - Case 3 Project stage: Supplement ML0810905002008-03-31031 March 2008 Supplemental Response to NRC Generic Letter 2004-02, Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized-Water Reactors - Notice of Completion Project stage: Supplement ML0811201592008-03-31031 March 2008 Enclosure 1, Supplemental Response Addressing GL-04-002 Actions, Calculation No. PCI-5343-S01, Rev. 0, Attachment D, Page 374 of 575 Through Calculation No. PCI-5343-S02, Rev 0, Attachment B, Page 100 of 631 Project stage: Supplement ML0810905022008-03-31031 March 2008 Enclosure 1, Supplemental Response Addressing GL-04-002 Actions, Figure 4.25 - Case 3 Through Calculation PCI-5464-S01, Page 107 Project stage: Supplement ML0810905052008-03-31031 March 2008 Enclosure 1, Supplemental Response Addressing GL-04-002 Actions, Calculation No. PCI-5464-S01, Rev. 2, Attachment B, Page 385 Through 680 Project stage: Supplement ML0810905082008-03-31031 March 2008 Enclosure 1, Supplemental Response Addressing GL-04-002 Actions, Calculation No. PCI-5464-S02, Rev. 0, Attachment B Page 101 Through End Project stage: Supplement ML0833700332008-12-0303 December 2008 Request for Additional Information Regarding Generic Letter 2004-02. Potential Impact of Debris Blockage During Design Basis Accidents at Pressurized-Water Reactors (Tac No. MC4730) Project stage: RAI ML0907208692009-02-25025 February 2009 Calculation, ALION-CAL-TVA-2739-03, Rev. 4, Watts Bar Reactor Building GSI-191 Debris Generation Calculation. Project stage: Other ML0907208682009-03-0303 March 2009 Response to Request for Additional Information Regarding Generic Letter 2004-02,.Potential Impact of Debris Blockage During Design Basis Accidents at Pressurized-Water Reactors. Project stage: Response to RAI ML0926502602009-09-29029 September 2009 RAI, Regarding Generic Letter 2004-02, Potential Impact of Debris Blockage During Design Basis Accidents at Pressurized-Water Reactors Project stage: RAI ML0936502182009-12-23023 December 2009 GL 2004-02 Final RAI Responses Due Date Project stage: RAI ML1000601162010-01-0707 January 2010 Change of Response Date Regarding Request for Additional Information for Generic Letter 2004-02 Potential Impact of Debris Blockage During Design-Basis Accidents at Pressurized Project stage: RAI ML1015905562010-06-0909 June 2010 Request for Withholding Proprietary Information from Public Disclosure Related to Generic Letter 2004-02 Project stage: Other ML1016600442010-06-17017 June 2010 Summary of Conference Call with TVA on Proposed Response to Request for Additional Information on Generic Letter 2004-02 Project stage: RAI ML1107000312011-04-15015 April 2011 Notice of Meeting with Tennessee Valley Authority to Discuss Responses to NRC Requests for Additional Information for Generic Letter 2004-02, Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accident at Pre Project stage: RAI ML11152A1702011-05-12012 May 2011 05/12/2011-Meeting Slides from Meeting with TVA on Their Proposed Response to a Request for Additional Information on Generic Letter 2004-02 Project stage: Response to RAI ML11152A1632011-06-28028 June 2011 Summary of Meeting with TVA on Their Proposed Response to a Request for Additional Information on Generic Letter 2004-02 Project stage: RAI ML11230B2502011-11-0303 November 2011 Request for Withholding Proprietary Information from Public Disclosure Related to Generic Letter 2004-02 Project stage: Other CNL-15-009, Resolution of Generic Safety Issue 1912015-04-17017 April 2015 Resolution of Generic Safety Issue 191 Project stage: Request ML15191A1832015-09-17017 September 2015 Closeout of Generic Letter 2004-02, Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized-Water Reactors Project stage: Other CNL-15-252, License Amendment Request and Request for Deviation from 10 CFR 50, Appendix R in Support of Closure of Generic Safety Issue 191 (WBN-TS-16-01)2016-02-23023 February 2016 License Amendment Request and Request for Deviation from 10 CFR 50, Appendix R in Support of Closure of Generic Safety Issue 191 (WBN-TS-16-01) Project stage: Request 2008-03-31
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Category:Letter
MONTHYEARCNL-24-060, Supplement to Request for Approval of the Tennessee Valley Authority Nuclear Quality Assurance Program Description2024-09-24024 September 2024 Supplement to Request for Approval of the Tennessee Valley Authority Nuclear Quality Assurance Program Description CNL-24-047, Decommitment of Flood Mode Mitigation Improvement Systems2024-09-24024 September 2024 Decommitment of Flood Mode Mitigation Improvement Systems ML24262A0602024-09-23023 September 2024 Summary of August 19, 2024, Meeting with Tennessee Valley Authority Regarding a Proposed Supplement to the Tennessee Valley Authority Nuclear Quality Assurance Plan CNL-24-065, Tennessee Valley Authority – Central Emergency Control Center Emergency Plan Implementing Procedure Revisions2024-09-18018 September 2024 Tennessee Valley Authority – Central Emergency Control Center Emergency Plan Implementing Procedure Revisions 05000390/LER-2024-002, Automatic Reactor Trip Due to Main Generator Protection Relay Actuation2024-09-0505 September 2024 Automatic Reactor Trip Due to Main Generator Protection Relay Actuation IR 05000390/20240052024-08-28028 August 2024 Updated Inspection Plan and Assessment Follow-Up Letter for Watts Bar Nuclear Plant, Units 1 and 2 - Report 05000390-2024005 and 05000391-2024005 ML24218A1442024-08-27027 August 2024 Issuance of Amendment Nos. 169 and 75 Regarding Technical Specification Surveillance Requirement 3.9.5.1 to Reduce the Residual Heat Removal Flow Rate IR 05000390/20244022024-08-20020 August 2024 – Security Baseline Inspection Report 05000390-2024402 and 05000391/2024402 - Public CNL-24-061, Supplement to Application to Revise Function 5 of Technical Specification Table 3.3.2-1, ‘Engineered Safety Feature Actuation System Instrumentation,’ for the Sequoyah and Watts Bar (SQN-TS-23-02 and WBN-TS-23-08),2024-08-19019 August 2024 Supplement to Application to Revise Function 5 of Technical Specification Table 3.3.2-1, ‘Engineered Safety Feature Actuation System Instrumentation,’ for the Sequoyah and Watts Bar (SQN-TS-23-02 and WBN-TS-23-08), ML24219A0262024-08-12012 August 2024 Request for Withholding Information from Public Disclosure IR 05000390/20240022024-08-0707 August 2024 Integrated Inspection Report 05000390/2024002 and 05000391/2024002 Rev ML24204A2652024-07-25025 July 2024 Regulatory Audit Summary Related to Request to Revise Technical Specification Surveillance Requirement 3.9.5.1 to Reduce the Residual Heat Removal Flow Rate ML24199A0012024-07-22022 July 2024 Clarification and Correction to Exemption from Requirement of 10 CFR 37.11(c)(2) ML24172A1342024-07-15015 July 2024 Exemptions from 10 CFR 37.11(C)(2) (EPID L-2023-LLE-0024) - Letter ML24170A8002024-07-15015 July 2024 Issuance of Amendment Nos. 168 and 74 Regarding Revision to Technical Specification Table 1.1-1 for Required Number of Fully Tensioned Reactor Pressure Vessel Head Closure Bolts IR 05000390/20244402024-07-12012 July 2024 95001 Supplemental Inspection Supplemental Report 05000390-2024440 and 05000391-2024440 and Follow-Up Assessment Letter ML24131A0012024-07-0202 July 2024 Issuance of Amendment Nos. 167 and 73 Regarding Adoption of Technical Specification Task Force Traveler TSTF-427-A, Revision 2 CNL-24-052, Response to Request for Additional Information Regarding Application to Modify the Technical Specification Surveillance Requirement 3.9.5.1 (WBN-TS-21-14)2024-06-27027 June 2024 Response to Request for Additional Information Regarding Application to Modify the Technical Specification Surveillance Requirement 3.9.5.1 (WBN-TS-21-14) CNL-24-018, License Amendment Request for Adoption of Technical Specification Task Force Traveler TSTF-276-A, Revision 2, Regarding TS 3.8.1 AC Sources – Operating to Clarify Requirements for Diesel Generator Testing (WBN-TS2024-06-25025 June 2024 License Amendment Request for Adoption of Technical Specification Task Force Traveler TSTF-276-A, Revision 2, Regarding TS 3.8.1 AC Sources – Operating to Clarify Requirements for Diesel Generator Testing (WBN-TS ML24089A1152024-06-21021 June 2024 Transmittal Letter, Environmental Assessments and Findings of No Significant Impact Related to Exemption Requests from 10 CFR 37.11(c)(2) ML24141A0482024-05-17017 May 2024 EN 56958_1 Ametek Solidstate Controls, Inc ML24100A7642024-05-16016 May 2024 Issuance of Amendment No. 166 Regarding Revision to Technical Specification 3.8.2, AC Sources-Shutdown, to Remove Reference to C-S Diesel Generator (CNL-23-062) IR 05000390/20240012024-05-14014 May 2024 Integrated Inspection Report 05000390/2024001 and 05000391/2024001 CNL-24-040, Tennessee Valley Authority - Central Emergency Control Center Emergency Plan Implementing Procedure Revisions2024-05-0808 May 2024 Tennessee Valley Authority - Central Emergency Control Center Emergency Plan Implementing Procedure Revisions IR 05000391/20240072024-04-30030 April 2024 Assessment Follow-up Letter for Watts Bar Nuclear Plant, Unit 2 – Report 05000391/2024007 ML24120A1182024-04-29029 April 2024 – Notification of NRC Supplemental Inspection (95001) and Request for Information CNL-24-037, Clinch River, Sequoyah, Units 1 and 2, Watts Bar, Unit 1 and 2, Nuclear Quality Assurance Plan, TVA-NQA-PLN89-A, Revision 422024-04-22022 April 2024 Clinch River, Sequoyah, Units 1 and 2, Watts Bar, Unit 1 and 2, Nuclear Quality Assurance Plan, TVA-NQA-PLN89-A, Revision 42 ML24087A1912024-04-18018 April 2024 Exemption from Select Requirements of 10 CFR Part 73, Security Notifications, Reports, and Recordkeeping and Suspicious Activity Reporting CNL-24-010, License Amendment Request to Recapture Low-Power Testing Time (WBN-TS-23-19)2024-04-17017 April 2024 License Amendment Request to Recapture Low-Power Testing Time (WBN-TS-23-19) CNL-24-024, Hydrologic Engineering Center River Analysis System Project Milestone Status Update2024-04-17017 April 2024 Hydrologic Engineering Center River Analysis System Project Milestone Status Update CNL-24-033, Central Emergency Control Center Emergency Plan Implementing Procedure Revisions2024-04-17017 April 2024 Central Emergency Control Center Emergency Plan Implementing Procedure Revisions ML24072A0052024-04-15015 April 2024 Issuance of Amendment Nos. 165 and 72 Regarding Increase in the Maximum Number of Tritium Producing Burnable Absorber Rods and Supporting Changes, and Revision to the Updated Final Safety Analysis Report CNL-24-004, Application to Modify the Watts Bar Nuclear Plant, Unit 1 and Unit 2 Technical Specifications for Main Control Room Chiller Completion Time Extension (WBN-TS-23-13)2024-04-0404 April 2024 Application to Modify the Watts Bar Nuclear Plant, Unit 1 and Unit 2 Technical Specifications for Main Control Room Chiller Completion Time Extension (WBN-TS-23-13) IR 05000390/20244012024-04-0202 April 2024 – Security Baseline Inspection Report 05000390/2024401 and 05000391/2024401 - (Public) CNL-24-020, Clinch River, Sequoyah, Units 1 and 2, Watts Bar, Units 1 and 2, Request for Approval of Quality Assurance Program Description and Application to Revise the Technical Specifications Associated with QAPD Requirements2024-04-0101 April 2024 Clinch River, Sequoyah, Units 1 and 2, Watts Bar, Units 1 and 2, Request for Approval of Quality Assurance Program Description and Application to Revise the Technical Specifications Associated with QAPD Requirements CNL-24-007, Annual Insurance Status Report2024-03-27027 March 2024 Annual Insurance Status Report CNL-24-008, Guarantee of Payment of Deferred Premiums - 2023 Annual Report2024-03-27027 March 2024 Guarantee of Payment of Deferred Premiums - 2023 Annual Report CNL-24-025, Notice of Intent to Pursue License Renewal for Watts Bar Nuclear Plant, Unit 1 - Submittal Schedule2024-03-25025 March 2024 Notice of Intent to Pursue License Renewal for Watts Bar Nuclear Plant, Unit 1 - Submittal Schedule ML24081A0262024-03-21021 March 2024 Emergency Plan Implementing Procedure Revisions ML24079A0312024-03-19019 March 2024 Wb 2024-301, Corporate Notification Letter (210-day Ltr) CNL-24-031, Supplement to Request for Exemption from Various Part 72 Regulations Resulting from Fuel Basket Design Control Compliance2024-03-18018 March 2024 Supplement to Request for Exemption from Various Part 72 Regulations Resulting from Fuel Basket Design Control Compliance CNL-24-028, Response to Request for Additional Information Regarding Watts Bar Nuclear Plant, Units 1 and 2, Exemption from Enhanced Weapons, Firearms Background Checks, and Security Event Notifications Implementation2024-03-14014 March 2024 Response to Request for Additional Information Regarding Watts Bar Nuclear Plant, Units 1 and 2, Exemption from Enhanced Weapons, Firearms Background Checks, and Security Event Notifications Implementation CNL-24-029, Response to Request for Additional Information Regarding Tennessee Valley Authority - Request for Exemption from Specific Requirements of 10 CFR Part 372024-03-14014 March 2024 Response to Request for Additional Information Regarding Tennessee Valley Authority - Request for Exemption from Specific Requirements of 10 CFR Part 37 IR 05000390/20240102024-03-0808 March 2024 Age-Related Degradation Inspection Report 05000390/2024010 and 05000391/2024010 CNL-24-012, Request for Exemption from Various Part 72 Regulations Resulting from Fuel Basket Design Control Compliance2024-02-28028 February 2024 Request for Exemption from Various Part 72 Regulations Resulting from Fuel Basket Design Control Compliance IR 05000390/20230062024-02-28028 February 2024 Annual Assessment Letter for Watts Bar Nuclear Plant Units 1 and 2 - Report 05000390/2023006 and 05000391/2023006 CNL-24-023, Central Emergency Control Center Emergency Plan Implementing Procedure Revision. Includes CECC EPIP-17, Revision 252024-02-20020 February 2024 Central Emergency Control Center Emergency Plan Implementing Procedure Revision. Includes CECC EPIP-17, Revision 25 ML24009A1712024-02-16016 February 2024 Environmental Assessment and Finding of No Significant Impact Related to an Increase in the Maximum Number of Tritium Producing Burnable Absorber Rods (EPID L-2023-LLA-0039) - Letter ML24019A0722024-02-14014 February 2024 Request for Withholding Information from Public Disclosure IR 05000390/20230042024-02-13013 February 2024 Integrated Inspection Report 05000390/2023004 and 05000391/2023004 and Apparent Violation 2024-09-05
[Table view] Category:Request for Additional Information (RAI)
MONTHYEARML24260A0322024-09-10010 September 2024 NRR E-mail Capture - Request for Additional Information Regarding the Watts Bar Unit 2 Steam Generator Tube Inspection Report for U2R5 ML24155A1372024-05-29029 May 2024 Email from K. Green to S. Hughes Request for Additional Information Related to License Amendment Request to Revise Residual Heat Removal Flow Rate ML24120A1182024-04-29029 April 2024 – Notification of NRC Supplemental Inspection (95001) and Request for Information ML24116A2012024-04-17017 April 2024 Nrctva ISFSI CBS (RFI) ML24045A0312024-02-14014 February 2024 NRR E-mail Capture - Request for Additional Information Related to the Exemption Request for the 10 CFR Part 73 Enhanced Weapons Rule ML23166A1142023-06-15015 June 2023 Document Request for Watts Bar Nuclear Plant - Radiation Protection Inspection - Inspection Report 2023-03 ML23067A2372023-03-0808 March 2023 WB_2023-02_RP_inspection_doc_request ML23030A3512023-01-25025 January 2023 Notification of Watts Bar Nuclear Plant - Design Bases Assurance Inspection (Programs) and Initial Information Request ML22343A0692022-12-0808 December 2022 NRR E-mail Capture - Request for Additional Information - Sequoyah Nuclear Plant, Units 1 and 2, and Watts Bar Nuclear Plant, Units 1 and 2, License Amendment Request to Revise Technical Specification 3.4.12 (L-2022-LLA-0103) ML22227A0272022-08-11011 August 2022 NRR E-mail Capture - Request for Additional Information Related to Alternative Requests RP-11 for Sequoyah Nuclear Plant, Units 1 and 2, and IST-RR-9 for Watts Bar Nuclear Plant, Units 1 and 2 ML22144A1002022-05-12012 May 2022 NRR E-mail Capture - Request for Additional Information Related to Tva'S Request to Revised the TVA Plants' Radiological Emergency Plans ML22115A1402022-04-25025 April 2022 NRR E-mail Capture - Requests for Confirmation of Information and Additional Information Regarding Watts Bar Nuclear Plant, Unit 2 Exemption Request Re 10 CFR Part 26 (L-2022-LLE-0017) ML22083A2372022-03-24024 March 2022 NRR E-mail Capture - Request for Additional Information and Confirmation of Information Related to Tva'S Request for Changes to Watts Bar Nuclear Plant, Units 1 and 2, Technical Specification 3.7.8 ML22056A3802022-02-25025 February 2022 Document Request for Watts Bar Nuclear Plant - Radiation Protection Inspection - Inspection Report 2022-02 ML21267A1392021-09-23023 September 2021 Document Request for Upcoming RP Inspection at Watts Bar ML21221A2602021-08-0909 August 2021 NRR E-mail Capture - Request for Additional Information Regarding Tva'S Request to Revise Watts Bar, Unit 1 Tech Specs Related to Continuous Opening of the Auxiliary Building Secondary Containment Enclosure Boundary ML21102A1312021-04-19019 April 2021 Request for Withholding Information from Public Disclosure for Watts Bar Nuclear Plant, Unit 1 ML21095A0402021-04-0202 April 2021 NRR E-mail Capture - Request for Additional Information Re Generic Letter 95-05 90-Day Report and LAR to Adjust Growth Rate for Thot (EPIDs L-2021-LRO-0003 and L-2021-LLA-0026) ML21095A0422021-04-0202 April 2021 NRR E-mail Capture - Added Clarification to RAI 2 for Thot LAR ML21091A0772021-04-0101 April 2021 NRR E-mail Capture - Request for Additional Information Regarding Tva'S Request to Revise Technical Specification 5.7.2.19, Containment Leakage Rate Testing Program ML21095A0442021-04-0101 April 2021 NRR E-mail Capture - Revised Draft RAI - Combined RAI Set for Watts Bar Unit 2 90-Day Report and Thot LAR (EPIDs L-2021-LRO-0003 and L-2021-LLA-0026) ML21095A0412021-04-0101 April 2021 NRR E-mail Capture - Revised Draft RAI - Combined RAI Set for Watts Bar Unit 2 90-Day Report and Thot LAR (EPIDs L-2021-LRO-0003 and L-2021-LLA-0026) ML21095A0462021-03-22022 March 2021 NRR E-mail Capture - Draft Request for Additional Information Regarding Tva'S Generic Letter 95-05 90-Day Report for Watts Bar Unit 2 ML21039A6402021-02-0808 February 2021 NRR E-mail Capture - Request for Additional Information Regarding Tva'S Request to Revise the Watts Bar Nuclear Plant, Unit 1 Technical Specifications Related to Steam Generator Tube Inspection Frequency ML21012A2032021-01-11011 January 2021 NRR E-mail Capture - Request for Additional Information Regarding Tva'S Request to Revise the Watts Bar UFSAR to Use Alternate Probability of Detection ML20350B5592020-12-15015 December 2020 NRR E-mail Capture - Request for Additional Information Regarding Tva'S Request to Adopt Traveler TSTF-490 Deletion of E Bar Definition and Revision to RCS Specific Activity Tech Spec ML20338A3202020-12-0303 December 2020 Notification of an NRC Fire Protection Team Inspection (NRC Inspection Report 05000390/2021011 and 05000391/2021011) and Request for Information ML20322A4412020-11-17017 November 2020 NRR E-mail Capture - Request for Additional Information Regarding Tva'S Request to Revise TS 3.7.11 Related to the MCR Chiller Replacement ML20322A4392020-11-0505 November 2020 NRR E-mail Capture - Draft Request for Additional Information Regarding Tva'S Request to Revise TS 3.7.11 Related to the MCR Chiller Replacement ML20308A3512020-11-0202 November 2020 Request for Additional Information on WBN Request for Exemption from 10 CFR Part 73, Appendix B, Section VI for the Conduct of an Annual Force-on-Force Exercise (EPID L-2020-LLE-0165 (COVID-19)) ML20253A1782020-09-0909 September 2020 Emergency Preparedness Program Inspection Request for Information ML20266G4592020-08-14014 August 2020 Notification of Inspection and Request for Information ML20196L8622020-07-14014 July 2020 NRR E-mail Capture - Watts Bar Nuclear Plant, Units 1 and 2 - Request for Additional Information Regarding Request to Implement the Full Spectrum LOCA Methodology ML20086G4802020-03-26026 March 2020 NRR E-mail Capture - Request for Additional Information for WBN2 Request Measurement Uncertainty Recapture Power Uprate (L-2019-LLS-0000) - Part 2 ML20085G3572020-03-25025 March 2020 NRR E-mail Capture - Request for Additional Information for WBN2 Request Measurement Uncertainty Recapture Power Uprate (L-2019-LLS-0000) ML20084M1942020-03-24024 March 2020 NRR E-mail Capture - Request for Additional Information for WBN2 Request Measurement Uncertainty Recapture Power Uprate (L-2019-LLS-0000) ML20083J3952020-03-12012 March 2020 NRR E-mail Capture - Draft Request for Additional Information for WBN2 Request Measurement Uncertainty Recapture Power Uprate (L-2019-LLS-0000) ML19340A6842019-12-0505 December 2019 NRR E-mail Capture - Request for Additional Information for WBN2 Request for One-Time Extension of Completion Time for TS 3.7.8 (L-2019-LLA-0020) ML19218A0302019-08-0505 August 2019 NRR E-mail Capture - Watts Bar Nuclear Plant - Second-Round Request for Additional Information Related to Application to Revise Technical Specifications Regarding DC Electrical Systems, TSTF-500, Revision 2 ML19218A0282019-07-25025 July 2019 NRR E-mail Capture - Watts Bar Nuclear Plant - Draft Second-Round Request for Additional Information Related to Application to Revise Technical Specifications Regarding DC Electrical Systems, TSTF-500, Revision 2 ML19186A4352019-07-0505 July 2019 NRR E-mail Capture - Watts Bar Nuclear Plant - Correction to Final Request for Additional Information Related to Application to Adopt 10 CFR 50.69 ML19169A3592019-06-18018 June 2019 NRR E-mail Capture - Watts Bar Nuclear Plant - Final Request for Additional Information Related to Application to Adopt 10 CFR 50.69 ML19148A7912019-05-28028 May 2019 NRR E-mail Capture - Sequoyah Nuclear Plant and Watts Bar Nuclear Plant - Final Request for Additional Information Related to Request for Alternative to OM Code Requirements ML19106A0462019-04-15015 April 2019 NRR E-mail Capture - Watts BAR, Units 1 and 2 Request for Additional Informatin (RAI) Regarding Changes to Technical Specifications Sections 3.8.1, 3.8.7, 3.8.8, and 3.8.9 ML19071A3542019-03-0808 March 2019 NRR E-mail Capture - Watts Bar Nuclear Plant - Final Request for Additional Information Related to Request to Adopt TSTF-425 to Relocate Specific Surveillance Frequency Requirements to Licensee-Controlled Program ML18313A2202018-11-0707 November 2018 Notification of Inspection and Request for Information for NRC Problem Identification and Resolution Inspection ML18282A6372018-10-0909 October 2018 NRR E-mail Capture - RAIs (Final) - LAR to Revise the Steam Generator Technical Specifications for Watts Bar Nuclear Plant, Unit 2 ML18270A2362018-09-26026 September 2018 NRR E-mail Capture - Watts Bar Units 1 and 2 RAIs - Modify TS 3.8.9 Completion Time for Inoperable 120V AC Vital Buses (L-2018-LLA-0050) ML18240A0702018-08-27027 August 2018 NRR E-mail Capture - RAI for Watts Bar Unit 2 Tpbars LAR and Watts Bar Units 1 and 2 LAR Related to Fuel Storage ML18199A1822018-07-17017 July 2018 NRR E-mail Capture - Request for Additional Information Regarding Watts Bar Unit 1 Extension of Surveillance Requirement Intervals 2024-09-10
[Table view] |
Text
February 10, 2006 Mr. Karl W. Singer Chief Nuclear Officer and Executive Vice President Tennessee Valley Authority 6A Lookout Place 1101 Market Street Chattanooga, Tennessee 37402-2801
SUBJECT:
WATTS BAR NUCLEAR PLANT, UNIT 1, REQUEST FOR ADDITIONAL INFORMATION RE: RESPONSE TO GENERIC LETTER 2004-02, POTENTIAL IMPACT OF DEBRIS BLOCKAGE ON EMERGENCY RECIRCULATION DURING DESIGN-BASIS ACCIDENTS AT PRESSURIZED-WATER REACTORS (TAC NO. MC4730)
Dear Mr. Singer:
On September 13, 2004, the Nuclear Regulatory Commission (NRC) issued Generic Letter (GL) 2004-02, Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized-Water Reactors, as part of the NRCs efforts to assess the likelihood that the emergency core cooling system (ECCS) and containment spray system (CSS) pumps at domestic pressurized water reactors (PWRs) would experience a debris-induced loss of net positive suction head margin during sump recirculation. The NRC issued this GL to all PWR licensees to request that addressees (1) perform a mechanistic evaluation using an NRC-approved methodology of the potential for the adverse effects of post-accident debris blockage and operation with debris-laden fluids to impede or prevent the recirculation functions of the ECCS and CSS following all postulated accidents for which the recirculation of these systems is required, and (2) implement any plant modifications that the above evaluation identifies as being necessary to ensure system functionality. Addressees were also required to submit information specified in GL 2004-02 to the NRC in accordance with Title 10 of the Code of Federal Regulations Section 50.54(f). Additionally, in the GL, the NRC established a schedule for the submittal of the written responses and the completion of any corrective actions identified while complying with the requests in the GL.
By letter dated March 7, 2005, as supplemented by letters dated July 21, 2005, and September 1, 2005, Tennessee Valley Authority provided a response to the GL. The NRC staff is reviewing and evaluating your response along with the responses from all PWR licensees.
The NRC staff has determined that responses to the questions in the enclosure to this letter are necessary in order for the staff to complete its review. Please note that the Office of Nuclear Reactor Regulations Division of Component Integrity is still conducting its initial reviews with respect to coatings. Although some initial coatings questions are included in the enclosure to this letter, the NRC might issue an additional request for information regarding coatings issues in the near future.
K. W. Singer February 10, 2006 Please provide your response within 60 days from the date of this letter. If you have any questions, please contact me at (301) 415-1364.
Sincerely,
/RA/
Douglas V. Pickett, Project Manager Plant Licensing Branch II-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-390
Enclosure:
Request for Additional Information cc w/encl: See next page
K. W. Singer February 10, 2006 Please provide your response within 60 days from the date of this letter. If you have any questions, please contact me at (301) 415-1364.
Sincerely,
/RA/
Douglas V. Pickett, Project Manager Plant Licensing Branch II-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-390
Enclosure:
Request for Additional Information cc w/encl: See next page Distribution:
PUBLIC RidsNrrDorlDpr RArchitzel LPLII-2 Reading File WBateman THaffera RidsNrrDorlLpld JLehning RidsNrrPMDPickett RidsNrrLACSola HWagage RidsOgcRp MMurphy SLu RidsAcrsAcnwMailCenter PKlein JHannon MScott MYoder RidsRgn2Mailcenter RidsNrrPMJHopkins BSingal (BKS1)
Accession No.: ML060380082 *per e-mail NRR-088 OFFICE LPL2-2/PM LPL2-2/LA DSS/SSIB DCI/CSGB LPL2-2/BC NAME DPickett CSola DSolorio* EMurphy* MMarshall DATE 02/08/2006 02/08/2006 2/6/06 02/08/2006 02/10/2006 OFFICIAL RECORD COPY
Mr. Karl W. Singer Tennessee Valley Authority WATTS BAR NUCLEAR PLANT cc:
Mr. Ashok S. Bhatnagar, Senior Vice President Mr. Glenn W. Morris, Manager Nuclear Operations Corporate Nuclear Licensing Tennessee Valley Authority and Industry Affairs 6A Lookout Place Tennessee Valley Authority 1101 Market Street 4X Blue Ridge Chattanooga, TN 37402-2801 1101 Market Street Chattanooga, TN 37402-2801 Mr. Larry S. Bryant, Vice President Nuclear Engineering & Technical Services Mr. Paul L. Pace, Manager Tennessee Valley Authority Licensing and Industry Affairs 6A Lookout Place Watts Bar Nuclear Plant 1101 Market Street Tennessee Valley Authority Chattanooga, TN 37402-2801 P.O. Box 2000 Spring City, TN 37381 Mr. Robert J. Beecken, Vice President Nuclear Support Mr. Jay Laughlin, Plant Manager Tennessee Valley Authority Watts Bar Nuclear Plant 6A Lookout Place Tennessee Valley Authority 1101 Market Street P.O. Box 2000 Chattanooga, TN 37402-2801 Spring City, TN 37381 Mr. Michael D. Skaggs Senior Resident Inspector Site Vice President Watts Bar Nuclear Plant Watts Bar Nuclear Plant U.S. Nuclear Regulatory Commission Tennessee Valley Authority 1260 Nuclear Plant Road P.O. Box 2000 Spring City, TN 37381 Spring City, TN 37381 County Executive General Counsel 375 Church Street Tennessee Valley Authority Suite 215 ET 11A Dayton, TN 37321 400 West Summit Hill Drive Knoxville, TN 37902 County Mayor P. O. Box 156 Mr. John C. Fornicola, Manager Decatur, TN 37322 Nuclear Assurance and Licensing Tennessee Valley Authority Mr. Lawrence E. Nanney, Director 6A Lookout Place Division of Radiological Health 1101 Market Street Dept. of Environment & Conservation Chattanooga, TN 37402-2801 Third Floor, L and C Annex 401 Church Street Nashville, TN 37243-1532 Ms. Ann P. Harris 341 Swing Loop Road Rockwood, Tennessee 37854
GL 2004-02 RAI Questions Plant Materials
- 1. (Not applicable).
- 2. Identify the amounts (i.e., surface area) of the following materials that are:
(a) submerged in the containment pool following a loss-of-coolant accident (LOCA),
(b) in the containment spray zone following a LOCA:
- aluminum
- zinc (from galvanized steel and from inorganic zinc coatings)
- copper
- carbon steel not coated
- uncoated concrete Compare the amounts of these materials in the submerged and spray zones at your plant relative to the scaled amounts of these materials used in the Nuclear Regulatory Commission (NRC) nuclear industry jointly-sponsored Integrated Chemical Effects Tests (ICET) (e.g., 5x the amount of uncoated carbon steel assumed for the ICETs).
- 3. Identify the amount (surface area) and material (e.g., aluminum) for any scaffolding stored in containment. Indicate the amount, if any, that would be submerged in the containment pool following a LOCA. Clarify if scaffolding material was included in the response to Question 2.
- 4. Provide the type and amount of any metallic paints or non-stainless steel insulation jacketing (not included in the response to Question 2) that would be either submerged or subjected to containment spray.
Containment Pool Chemistry
- 5. Provide the expected containment pool pH during the emergency core cooling system (ECCS) recirculation mission time following a LOCA at the beginning of the fuel cycle and at the end of the fuel cycle. Identify any key assumptions.
- 6. For the ICET environment that is the most similar to your plant conditions, compare the expected containment pool conditions to the ICET conditions for the following items:
boron concentration, buffering agent concentration, and pH. Identify any other significant differences between the ICET environment and the expected plant-specific environment.
- 7. For a large-break LOCA (LBLOCA), provide the time until ECCS external recirculation initiation and the associated pool temperature and pool volume. Provide estimated pool temperature and pool volume 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> after a LBLOCA. Identify the assumptions used for these estimates.
Enclosure
Plant-Specific Chemical Effects
- 8. Discuss your overall strategy to evaluate potential chemical effects including demonstrating that, with chemical effects considered, there is sufficient net positive suction head margin available during the ECCS mission time. Provide an estimated date with milestones for the completion of all chemical effects evaluations.
- 9. Identify, if applicable, any plans to remove certain materials from the containment building and/or to make a change from the existing chemicals that buffer containment pool pH following a LOCA.
- 10. If bench-top testing is being used to inform plant specific head loss testing, indicate how the bench-top test parameters (e.g., buffering agent concentrations, pH, materials, etc.)
compare to your plant conditions. Describe your plans for addressing uncertainties related to head loss from chemical effects including, but not limited to, use of chemical surrogates, scaling of sample size and test durations. Discuss how it will be determined that allowances made for chemical effects are conservative.
Plant Environment Specific
- 11. Provide a detailed description of any testing that has been or will be performed as part of a plant-specific chemical effects assessment. Identify the vendor, if applicable, that will be performing the testing. Identify the environment (e.g., borated water at pH 9, deionized water, tap water) and test temperature for any plant-specific head loss or transport tests. Discuss how any differences between these test environments and your plant containment pool conditions could affect the behavior of chemical surrogates.
Discuss the criteria that will be used to demonstrate that chemical surrogates produced for testing (e.g., head loss, flume) behave in a similar manner physically and chemically as in the ICET environment and plant containment pool environment.
- 12. For your plant-specific environment, provide the maximum projected head loss resulting from chemical effects (a) within the first day following a LOCA, and (b) during the entire ECCS recirculation mission time. If the response to this question will be based on testing that is either planned or in progress, provide an estimated date for providing this information to the NRC.
ICET 1 and ICET 5 Plants
- 13. Results from the ICET #1 environment and the ICET #5 environment showed chemical products appeared to form as the test solution cooled from the constant 140 oF test temperature. Discuss how these results are being considered in your evaluation of chemical effects and downstream effects.
Trisodium Phosphate Plants
- 14. (Not applicable).
- 15. (Not applicable).
- 16. (Not applicable).
Additional Chemical Effects Questions
- 17. (Not applicable).
- 18. (Not applicable).
- 19. (Not applicable).
- 20. (Not applicable).
- 21. (Not applicable).
- 22. (Not applicable).
- 23. The Watts Bar GL 2004-02 response indicates that the critical parameters in the ICET
- 5 bound the plant parameters. This response also indicates the post-accident pH in the Watts Bar sump ranges from 7.5-10 pH, but will generally be less than the value used in testing. Given the ICET #5 pH ranged between 8 and 8.5, discuss how your plant-specific chemical effects evaluation accounts for potential pH levels greater than those tested in ICET #5.
- 24. (Not applicable).
Coatings Generic - All Plants
- 25. Describe how your coatings assessment was used to identify degraded qualified/acceptable coatings and determine the amount of debris that will result from these coatings. This should include how the assessment technique(s) demonstrates that qualified/acceptable coatings remain in compliance with plant licensing requirements for design basis accident (DBA) performance. If current examination techniques cannot demonstrate the coatings ability to meet plant licensing requirements for DBA performance, licensees should describe an augmented testing and inspection program that provides assurance that the qualified/acceptable coatings continue to meet DBA performance requirements. Alternately, assume all containment coatings fail and describe the potential for this debris to transport to the sump.
Plant Specific
- 26. (Not applicable).
- 27. (Not applicable).
- 28. (Not applicable).
- 29. (Not applicable).
- 30. The NRC staffs safety evaluation (SE) addresses two distinct scenarios for formation of a fiber bed on the sump screen surface. For a thin bed case, the SE states that all coatings debris should be treated as particulate and assumes 100% transport to the sump screen. For the case in which no thin bed is formed, the staffs SE states that the coatings debris should be sized based on plant-specific analyses for debris generated from within the zone of influence (ZOI) and from outside the ZOI, or that a default chip size equivalent to the area of the sump screen openings should be used (Section 3.4.3.6). Describe how your coatings debris characteristics are modeled to account for your plant-specific fiber bed (i.e. thin bed or no thin bed). If your analysis considers both a thin bed and a non-thin bed case, discuss the coatings debris characteristics assumed for each case. If your analysis deviates from the coatings debris characteristics described in the staff-approved methodology, provide justification to support your assumptions.
- 31. Your submittal indicated that you had taken samples for latent debris in your containment, but did not provide any details regarding the number, type, and location of samples. Please provide these details.
- 32. You indicated that you would be evaluating downstream effects in accordance with WCAP 16406-P. The NRC is currently involved in discussions with the Westinghouse Owners Group (WOG) to address questions/concerns regarding this WCAP on a generic basis, and some of these discussions may resolve issues related to your particular station. The following issues have the potential for generic resolution; however, if a generic resolution cannot be obtained, plant-specific resolution will be required. As such, formal RAIs will not be issued on these topics at this time, but may be needed in the future. It is expected that your final evaluation response will specifically address those portions of the WCAP used, their applicability, and exceptions taken to the WCAP. For your information, topics under ongoing discussion include:
- a. Wear rates of pump-wetted materials and the effect of wear on component operation
- b. Settling of debris in low flow areas downstream of the strainer or credit for filtering leading to a change in fluid composition
- c. Volume of debris injected into the reactor vessel and core region
- d. Debris types and properties
- e. Contribution of in-vessel velocity profile to the formation of a debris bed or clog
- f. Fluid and metal component temperature impact
- g. Gravitational and temperature gradients
- h. Debris and boron precipitation effects
- i. ECCS injection paths
- j. Core bypass design features
- k. Radiation and chemical considerations
- l. Debris adhesion to solid surfaces
- m. Thermodynamic properties of coolant
- 14. Your response to GL 2004-02 question (d) (viii) indicated that an active strainer design will not be used, but does not mention any consideration of any other active approaches (i.e., backflushing). Was an active approach considered as a potential strategy or backup for addressing any issues?
- 15. The NRC staffs SE discusses a systematic approach to the break selection process where an initial break location is selected at a convenient location (such as the terminal end of the piping) and break locations would be evaluated at 5-foot intervals in order to evaluate all break locations. For each break location, all phases of the accident scenario are evaluated. It is not clear that you have applied such an approach. Please discuss the limiting break locations evaluated and how they were selected.
- 16. The staffs SE refers to Regulatory Guide 1.82 which lists considerations for determining the limiting break location (staff position 1.3.2.3). Please discuss how these considerations were evaluated as part of the Watts Bar break selection analyses.
- 17. The licensee did not provide information on the details of the debris characteristics (debris size distribution) assumptions other than to state that the Nuclear Energy Institute and SE methodologies were applied. Please provide a description of the assumptions applied in these evaluations and include a discussion of the technical justification for deviations from the SE-approved methodology.
- 18. Watts Bar operates with a tritium producing core which requires much higher boron concentration levels in the refueling water storage tank. Please discuss how this might influence a new screen design, particularly from a chemical effects perspective?
- 19. Has debris settling upstream of the sump strainer (i.e., the near-field effect) been credited or will it be credited in testing used to support the sizing or analytical design basis of the proposed replacement strainers? In the case that settling was credited for either of these purposes, estimate the fraction of debris that settled and describe the analyses that were performed to correlate the scaled flow conditions and any surrogate debris in the test flume with the actual flow conditions and debris types in the plants containment pool.
- 20. Are there any vents or other penetrations through the strainer control surfaces which connect the volume internal to the strainer to the containment atmosphere above the containment minimum water level? In this case, dependent upon the containment pool height and strainer and sump geometries, the presence of the vent line or penetration could prevent a water seal over the entire strainer surface from ever forming; or else this seal could be lost once the head loss across the debris bed exceeds a certain criterion, such as the submergence depth of the vent line or penetration. According to Appendix A to Regulatory Guide 1.82, Revision 3, without a water seal across the entire strainer surface, the strainer should not be considered to be fully submerged.
Therefore, if applicable, explain what sump strainer failure criteria are being applied for the vented sump scenario described above.