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Category:Letter
MONTHYEARML24219A0262024-08-12012 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-24-033, Central Emergency Control Center Emergency Plan Implementing Procedure Revisions2024-04-17017 April 2024 Central Emergency Control Center Emergency Plan Implementing Procedure Revisions 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 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-24-008, Guarantee of Payment of Deferred Premiums - 2023 Annual Report2024-03-27027 March 2024 Guarantee of Payment of Deferred Premiums - 2023 Annual Report CNL-24-007, Annual Insurance Status Report2024-03-27027 March 2024 Annual Insurance Status 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-24-029, 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 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 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 IR 05000390/20230042024-02-13013 February 2024 Integrated Inspection Report 05000390/2023004 and 05000391/2023004 and Apparent Violation ML24038A3342024-02-0707 February 2024 Change to South Texas Project Electric Generating Station (Stepgs) Emergency Plan 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 ML24008A2462024-01-18018 January 2024 Revision to the Reactor Vessel Material Surveillance Capsule Withdrawal Schedule 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 CNL-24-016, Supplement to Application to Modify the Technical Specification Surveillance Requirement 3.9.5.1 (WBN-TS-21-14)2024-01-10010 January 2024 Supplement to Application to Modify the Technical Specification Surveillance Requirement 3.9.5.1 (WBN-TS-21-14) CNL-23-052, Application to Adopt TSTF-427-A, Revision 2, Allowance for Non-Technical Specification Barrier Degradation on Supported System Operability2024-01-0909 January 2024 Application to Adopt TSTF-427-A, Revision 2, Allowance for Non-Technical Specification Barrier Degradation on Supported System Operability CNL-23-062, Application to Revise the Technical Specifications Section 3.8.2, AC Sources-Shutdown, to Remove Reference to the C-S Diesel Generator (WBN-TS-23-018)2024-01-0808 January 2024 Application to Revise the Technical Specifications Section 3.8.2, AC Sources-Shutdown, to Remove Reference to the C-S Diesel Generator (WBN-TS-23-018) ML23346A1382024-01-0303 January 2024 Regulatory Audit Summary Related to Request to Increase the Number of Tritium Producing Burnable Absorber Rods CNL-23-069, 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 IR 05000390/20234412023-12-21021 December 2023 Plantfinal Significance Determination for a Security-Related Greater than Green Finding, Nov, and Assessment Follow-up, 05000390-2023441 and 05000391-2023441-Public 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) 2024-08-07
[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
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- Tennessee Valley Authority, Post Office Box 2000, Spring City, Tennessee 37381-2000 October 16, 2012 10 CFR 50.46 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555-0001 Watts Bar Nuclear Plant, Unit 2 NRC Docket No. 50-391
Subject:
WATTS BAR NUCLEAR PLANT (WBN) 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 Reference 1: Supplemental Safety Evaluation Report (SSER) 24, "Safety Evaluation Report Related to the Operation of Watts Bar Nuclear Plant, Unit 2, Docket No. 50-391, Tennessee Valley Authority," published September 2011 The purpose of this letter is to report, in accordance with 10 CFR 50.46, a significant change in PCT of greater than 50 degrees (i.e., 175°F increase). TVA was recently notified by Westinghouse letter, LTR-LIS-12-413, dated September 20, 2012, that fuel pellet thermal conductivity degradation (TCD) and peaking factor burndown were not explicitly considered in the Watts Bar Unit 2 Best Estimate Large Break Loss-of-Coolant Accident (BE LBLOCA)
Analysis of Record (AOR). Taking TCD and peaking factor burndown into account resulted in the 175 0 F increase in PCT. This results in a new PCT of 1,727°F, replacing the 1,552 0 F value previously accepted by NRC in Reference 1.
Enclosure 1 provides an evaluation of this estimated effect. Since the estimated increase of 175 0 F PCT is based on the generic Westinghouse Owner's Group analysis, a specific WBN Unit 2 analysis will be performed to provide a unit-specific AOR PCT value prior to Unit 2 licensing. This action is captured as SSER open item no. 61; therefore, this action does not represent a new commitment. Enclosure 2 provides the Unit 2 Westinghouse Rackup Sheet.
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U.S. Nuclear Regulatory Commission Page 2 October 16, 2012 There are no new commitments made in this letter.
I declare under penalty of perjury that the foregoing is true and correct. Executed on the 1 6 th day of October, 2012.
If you have any questions, please contact me at (423) 365-2004.
Respectfully, Raymond A. Hruby, Jr.
General Manager, Technical Services Watts Bar Unit 2
Enclosures:
- 1. Evaluation of Fuel Pellet Thermal Conductivity Degradation and Peaking Factor Burndown
- 2. Westinghouse Rackup Sheet cc (Enclosures):
U. S. Nuclear Regulatory Commission Region II Marquis One Tower 245 Peachtree Center Ave., NE Suite 1200 Atlanta, Georgia 30303-1257 NRC Resident Inspector Unit 2 Watts Bar Nuclear Plant 1260 Nuclear Plant Road Spring City, Tennessee 37381
Enclosure I Evaluation of Fuel Pellet Thermal Conductivity Degradation and Peaking Factor Burndown
Background
Fuel pellet thermal conductivity degradation (TCD) and peaking factor burndown were not explicitly considered in the Watts Bar Unit 2 Best Estimate Large Break Loss-of-Coolant Accident (BE LBLOCA) Analysis of Record (AOR). NRC Information Notice 2011-21 (Reference 1) notified addressees of recent information obtained concerning the impact of irradiation on fuel thermal conductivity and its potential to cause significantly higher predicted peak cladding temperature (PCT) results in realistic emergency core cooling system (ECCS) evaluation models. This evaluation provides an estimated effect of fuel pellet TCD and peaking factor burndown on the PCT calculation for the WBN Unit 2 BE LBLOCA AOR. This change represents a Non-Discretionary Change in accordance with Section 4.1.2 of WCAP-13451 (Reference 2).
Affected Evaluation Model 2004 Westinghouse Realistic Large Break LOCA Evaluation Model Using ASTRUM Estimated Effect A quantitative evaluation, as discussed in Reference 3, was performed to assess the PCT effect of fuel pellet TCD and peaking factor burndown on the WBN Unit 2 BE LBLOCA analysis and concluded that the estimated PCT impact is 175 0 F for 10 CFR 50.46 reporting purposes. The peaking factor burndown included in the evaluation is provided in Table 1 and is conservative for the first cycle. Tennessee Valley Authority and its vendor, Westinghouse Electric Company LLC, utilize processes which ensure the LOCA analysis input values conservatively bound the as-operated plant values for those parameters and will be validated as part of the reload design process.
Table 1: Peaking Factors Assumed in the Evaluation of TCD Rod Burnup (MWd/MTU) FdH (1), (2) FQ Transient (1) FQ Steady-State 0 1.650 2.500 2.000 30,000 1.650 2.500 2.000 60,000 1.400 1.875 1.500 62,000 1.400 1.875 1.500 (1) Includes uncertainties.
(2) Hot assembly average power follows the same burndown, since it is a function of FdH.
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Enclosure I References
- 1. NRC Information Notice 2011-21, McGinty, T. J., and Dudes, L. A., "Realistic Emergency Core Cooling System Evaluation Model Effects Resulting From Nuclear Fuel Thermal Conductivity Degradation," December 13, 2011. (NRC ADAMS #
ML113430785)
- 2. WCAP-13451, "Westinghouse Methodology for Implementation of 10 CFR 50.46 Reporting," October 1992.
- 3. OG-12-386, "For Information Only - Input Supporting the PWROG LBLOCA Program Regarding Nuclear Fuel Thermal Conductivity Degradation (PA-ASC-1073, Revision 0) (Proprietary/Non-Proprietary)," September 18, 2012.
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Enclosure 2 Westinghouse Rackup Sheet Westinghouse LOCA Peak Clad Temperature Summary for ASTRUM Best Estimate Large Break Plant Name: Watts Bar Unit 2 Future Utiliq"Name: Tennessee Valley Authority Reision Date: 9/20/2012 Analvsit Information EM: ASTRUTIM (2004) Analysis Date: 10114/2009 Limiting Break Size: Split FQ: 2.5 FdH: 1.65 Fuel: RFA-2 SGTP (%): 10 Notes:
Clad Temp (IF) Ref. Notes LICENSING BASIS Analysis-Of-Record PCT 15152 1 PCT ASSESSMENTS (Delta PCT)
A. PRIOR ECCS MODEL ASSESSMENTS I . None 0 B. PLANN,-ED PLANT MODIFICATION EVALUATIONS I . None 0 C. 2012 ECCS MODEL ASSESSMENTS I . Evaluation of Fuel Pellet Thermal Conductivity Degradation and 175 2 Peaking Factor Burndown D. OTHER*
1 - None 0 LICENSING BASIS PCT + PCT ASSESSMENTS PCT = 1727
- It is recommended that the licensee determine if these PCT allocations should be considered with respect To 10 CFR 50.46 reporting requirements.
References:
1 . WCAP- I7093-P. Revision 0. "Best-Estimate Anals-sis of the Large-Break Loss-of-Coolant Accident for Watts Bar Unit 2 Nuclear Power Plant Using the ASTRU`-M Methodology." December 2009.
2 . LTR-LIS-12-413. -Watts Bar Units I and 2. 10 CFR 30.46 Notification and Reporting for Fuel Pellet Thermal Conductivity Degradation and Peaking Factor Bundosn.s" September 20. 2012.
Notes:
(a) This evaluation credits peaking factor bumdown, see Reference 2.
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