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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:Licensee 30-Day Written Event Report
MONTHYEARML17235A9052017-08-21021 August 2017 10 CFR 50.46 - 30-Day Report for Watts Bar Nuclear Plant Unit 1 CNL-15-034, Submittal of 30-Day Report of Changes and Errors to the Calculated Peak Cladding Temperature2015-02-0606 February 2015 Submittal of 30-Day Report of Changes and Errors to the Calculated Peak Cladding Temperature ML13246A0762013-08-28028 August 2013 Emergency Core Cooling System Evaluation Model Changes - 30 Day Report ML13120A0052013-04-25025 April 2013 10 CFR 50.46 - 30-Day Report and Annual Report for 2012 ML13120A0042013-04-25025 April 2013 10 CFR 50.46 30-Day Report of Changes and Errors to the Calculated Peak Cladding Temperatures and Annual Report for 2012 ML13080A4052013-03-19019 March 2013 Day Report Changes to the Calculated Peak Cladding Temperature Emergency Core Cooling System Evaluation Model ML12296A2542012-10-18018 October 2012 CFR 50.46 - 30-Day Special Report ML12296A2262012-10-16016 October 2012 Watts, Unit 2, 10 CFR 50.46 Estimated Increase in Peak Clad Temperature (PCT) Due to the Effect of Fuel Pellet Thermal Conductivity Degradation and Peaking Factor Burndown Not Being Considered - 30 Day Report ML0718603882007-07-0303 July 2007 Unit 1 - Emergency Core Cooling System (ECCS) Evaluation Model Changes - 30 Day Report and Annual Notification and Reporting for 2006 ML0523101272005-08-16016 August 2005 Emergency Core Cooling System Evaluation Model Changes - 30 Day Report - 10 CFR 50.46 Notification 2017-08-21
[Table view] Category:Written Event Report (30 or 60 day)
[Table view] |
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Tennessee Valley Authority, Post Office Box 2000, Spring City, Tennessee 37381-2000 AUG 16 2005 10 CFR 50.46 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555-0001 In the Matter of the ) Docket No. 50-390 Tennessee Valley Authority WATTS BAR NUCLEAR PLANT (WBN) UNIT 1 - EMERGENCY CORE COOLING SYSTEM (ECCS) EVALUATION MODEL CHANGES - 30 DAY REPORT - 10 CFR 50.46 NOTIFICATION
References:
- 1. TVA Letter to NRC, February 21, 2003, "WBN Unit 1 -
Emergency Core Cooling System (ECCS) Evaluation Model changes - 30 Day Report.
- 2. TVA Letter to NRC, April 19, 2005, "WBN Unit 1 -
Emergency Core Cooling System (ECCS) Evaluation Model Changes - Annual Notification and Reporting for 2004"
- 3. Westinghouse letter to TVA (WAT-D-11364), August 4, 2005, "Watts Bar Nuclear Plant, "LOCA Peak Clad temperature Summary for Small Break" The purpose of this letter is notify the NRC of a change in the WBN ECCS evaluation models for peak cladding temperature (PCT) in accordance with 10 CFR 50.46 related to a temporary change of more than 50 degrees F in calculated PCT. As reported by Westinghouse in Reference 3, this temporary change to WBN's ECCS evaluation model affects the small break LOCA (SBLOCA) analysis, and is described in Enclosure 1. The PCT margin allocation resulting from this change is summarized in Enclosure 2.
AC (,
Poed Mnrecycw Papew
U.S. Nuclear Regulatory Commission Page 2 AUG 16 2005 As discussed in Enclosure 1, TVA has experienced a repeat condition (Reference 1) involving apparent leakage when running the Watts Bar Unit 1 Safety Injection (SI) pumps which could result in diverting some SI flow to the pressurizer relief tank (PRT). TVA had previously taken measures to identify and correct this situation, including evaluation and replacement/refurbishment of SIS piping relief valves during the Unit 1 Cycle 5 refueling outage. Following this valve replacement, no leakage was identified until a repeat occurrence on July 17, 2005. TVA has decided to conservatively treat this event as a recurrence of the condition and is performing additional cause determinations.
TVA requested Westinghouse to evaluate the impact of this condition. Their evaluation results, Reference 3, were received by TVA on August 4, 2005, and concluded that there will be sufficient flow to meet the requirements of the safety analyses. Westinghouse evaluated the SI flow reduction for its impact on SBLOCA and BELOCA. As a result, a temporary PCT penalty of 120 degrees F has been assessed on SBLOCA for the reduction in SI flow. This penalty has been added to the PCT Summary Sheet in Enclosure 2 and is expected to remain in place for the duration of the current operating cycle (Cycle 7). As shown in the summary sheet, the inclusion of this penalty results in a PCT of 1305 degrees F which is considerably less than the 2200 degrees F regulatory limit.
There was no impact associated with the limiting PCT for BELOCA.
The temporary PCT assessment of 120OF for SBLOCA exceeds the threshold defined in 10 CFR 50.46(a)(3)(i) for a change of more than 500 F in calculated PCT. Therefore, TVA is reporting this change within the 30-day time limit specified in 10 CFR 50.46. In accordance with 10 CFR 50.46(a)(3)(ii), TVA is required to provide a proposed schedule for providing a reanalysis or taking other actions needed to show compliance with 50.46 requirements for the changes or errors discussed above. As a result of the temporary nature of the PCT assessment due to a hardware condition, and based on the acceptable evaluation results described herein, the WBN SBLOCA ECCS Model for the current cycle satisfies and complies with the 10 CFR 50.46 acceptance criteria.
Accordingly, TVA has completed the analysis required of 10 CFR 50.46 for changes or errors in an ECCS model and no further action is currently required. Because the SBLOCA change is a temporary condition which will be moot after the correction of the safety injection flow deficiency, TVA does not consider it will be necessary to make a 30-day report regarding the negative 120OF PCT change (increasing margin) that will occur when WBN reverts back to the previous SBLOCA model.
U.S. Nuclear Regulatory Commission Page 3 AUG 16 2005 There are no regulatory commitments in this letter. Should there be questions regarding the information provided in this letter, please call me at (423) 365-1824.
Sincerely, P . Pace Manager, Site Licensing and Industry Affairs Enclosures
- 1. Description of Change which affects WBN's Emergency Core Cooling System Evaluation Model(s) and its Calculation of Peak Cladding Temperature
- 2. Summary of Peak Cladding Temperature Margin Allocations Resulting from Change to the Emergency Core Cooling System Evaluation Model cc: See Page 4
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U.S. Nuclear Regulatory Commission Page 4 AUG 16 2005 PLP:
Enclosures cc (Enclosures)
NRC Resident Inspector Watts Bar Nuclear Plant 1260 Nuclear Plant Road Spring City, Tennessee 37381 Mr. D. V. Pickett, Project Manager U.S. Nuclear Regulatory Commission MS 08G9 One White Flint North 11555 Rockville Pike Rockville, Maryland 20852-2738 U.S. Nuclear Regulatory Commission Region II Sam Nunn Atlanta Federal Center 61 Forsyth St., SW, Suite 23T85 Atlanta, Georgia 30303
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ENCLOSURE 1 DESCRIPTION OF CHANGE WHICH AFFECTS WBN'S EMERGENCY CORE COOLING SYSTEM EVALUATION MODEL(S) AND ITS CALCULATION OF PEAK CLADDING TEMPERATURE
- 1. Evaluation of Temporary Safety Injection Leakage to Pressurizer Relief Tank (PRT)
Background
Westinghouse was informed by TVA of an apparent leak when running the Safety Injection (SI) pumps in Watts Bar Unit 1 which could result in a loss of up to 30 gpm SI flow to the pressurizer relief tank (PRT). TVA requested Westinghouse to evaluate the impact of this condition. Based on the following evaluations, Westinghouse concluded that the SI shortfall can be accommodated by the amount of margin available and/or the lack of sensitivity to the SI flow volume in the various design basis analyses, and the pump performance will not be degraded and there will be sufficient flow to meet the requirements of the safety analyses. This conclusion is valid for the duration of the current operating cycle (Cycle 7) and is not intended to support a permanent reduction in SI flow.
In particular, the evaluations did account for the presence of Tritium Producing Burnable Absorber Rods in current cycle.
Affected Evaluation Models
- 1. 1985 Westinghouse Small Break LOCA Evaluation Model with NOTRUMP
- 2. 1996 Westinghouse Best Estimate Large Break LOCA Evaluation Model Estimated Effect SBLOCA The 30 gpm SI flow reduction was evaluated for its impact on small break LOCA (SBLOCA). The impact was evaluated based on the SBLOCA analysis of record (References 1 and 2). The most recent small break LOCA PCT summary sheet was transmitted via Reference 3. A PCT penalty of 120 degrees F has been assessed for the reduction in SI flow. This penalty, which has been added to the PCT Summary Sheet provided in Enclosure 2, is expected to remain in place for the duration of the current operating cycle (Cycle 7). As shown in the summary sheet, the inclusion of this penalty results in a PCT of 1305 degrees F which is considerably less than the 2200 degrees F regulatory limit.
El-1
Best Estimate LBLOCA (BELOCA)
The BELOCA analysis for Watts Bar was evaluated for the impact of the reduction in SI flow. It was determined that the 30 gpm reduction results in a total integrated SI flow reduction of 3.36 percent. Based on a calculation documented in Reference 4, which reduced overall SI flow by 10 percent, it is concluded that the 30 gpm SI flow reduction has no effect on the limiting PCT for the BELOCA.
References
- 1. WAT-D-10337, "Tennessee Valley Authority, Watts Bar Nuclear Plant, Final Safety Evaluation to Support Technical Specification Changes," March 5, 1997.
- 2. WAT-D-10356, "Tennessee Valley Authority, Watts Bar Nuclear Plant Units 1 & 2, Final Report and Safety Evaluation for 10% SGTP Program," June 2, 1997.
- 3. Westinghouse letter to TVA (WAT-D-11364), August 4, 2005, "Watts Bar Nuclear Plant, "LOCA Peak Clad temperature Summary for Small Break."
- 4. WCAP-14839, "Best Estimate Analysis of the Large Break Loss of Coolant Accident for the Watts Bar Nuclear Plant," July 1997.
E1-2
ENCLOSURE 2
SUMMARY
OF PEAK CLADDING TEMPERATURE MARGIN ALLOCATIONS RESULTING FROM CHANGE TO THE EMERGENCY CORE COOLING SYSTEM EVALUATION MODEL
Westinahouse LOCA Pcak Clad Temperaturc Summary for Small Break Plant Name: Watts Bar Unit 1 Utility Name: Tenncsscc Vailcy Authority Revision Date: 7 /26,;05 Altalvyis Information Elf: NOTRUNIP Analsis Date: 1 1I;96 Linmlting Break SIke: 4 inch FQ: 2.5 Fdll: 1.65 Fuel: Vantage + SGTI' (V.): 10 Notes: Mixed Core - Vantage -.. Performance - .' RfA-Z Clad Temp (IF) Ref. Notes LICENSING BASIS Analysis-Of-Record rCT 1126 1,2 MARGIN ALLOCATIONS (Delta P CT)
A. PRIOR PERMAINENT ECCS MODEL ASSESSMENTS I . NOTRLM-P MEixturc Lceel Tra;king . Region Depletion Efrors 13 4 2 . NOTP.UMP Bubble Rise. Dritl Flt Model lnconsistency Corrections 3j 5 B. PLANNED PLANT CHANGE EVALUATIONS I. Annular Blankets 10 3 2 . IncreasedStrokcTimc for the ECCS 'alves 0 6 C. 2005 PERMNANENT ECCS MODEL ASSESSMENTS I . None 0 D. TE'MPORARY ECCS MODEL ISSUES*
I . Leaking SIS Relief Valvc 120 7 E. OTHER I . Tavg Uncertainiyof60F I LICENSING BASIS PCT + MARGIN ALLOCATIONS PCT - 1305 It is icconunended that these temporary PCT allocations which nddrcss current LOCA model issues not bc considered with respecl to 10 CFR 50.46 reporting requirements.
References:
I . WAT-D-I 0337. "Tcnncssce Valley Authcritv. Narts Bar Nuclear Plant, Final Safety Evaluation to Support Technical Specifization Changes." March 5, 1997.
2 . WAT-D.10356, 'Tennessee Valley Authority lVatts Bar Nuclear Plant Units I & 2. Final Report and Safety Evaluation for the 10% SGTP Program." June 2. 1997.
3 WAT-D.106 IS. "Tennessee Valley .Authority: Nvats Bar Nucear Plant Unit 1. 10 CFR 50.46 Annual .Notification and Reporting for 1998." March 5. 1999.
4 . WAT-D-I 0810. "Tcnnessee Valley Authority, lVars Bar Nuclear Phlnt Unit 1. 10 CrR 50A.6 Appendix K (BSRT/BASH .XOTRPUMtP) Evaluation Mlodel Mlid-.Vear 'otirciction and Reporting for 2000." June 30.2000.
S . AT.D.l 1195. 'I0 CFR 50.46 Mlid-YCar No(ilkation and Rcporting for 2003," November 2003.
6 . WVA D-I 1285. "Evaluation ofProposed Changes to the Strokc Time for the ECCS Valves,"November2004.
7 . VAT-D-l 1360. 'Safety Injection Pump Discharge Relief Valve Leakage Evaluation." July2005.
Westinahouse LOCA Peak Clad Temperature Summary for Small Break Plant Name: Watts BarUrnt 1 Utilit 'Namc: Tennessec Valley Authority Revision Date: 7/26/05 Notes:
None