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EPID:L-2021-LRO-0003, Expedited Application for Approval to Use a Growth Rate Temperature Adjustment When Implementing the Generic Letter 95-05 Analysis for the (WBN TS-391-21-002) (Approved, Closed) |
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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 Performance Review
MONTHYEARML21350A1662022-01-0505 January 2022 Review of the Fall 2020 Generic Letter 95-05 Voltage-Based Alternate Repair Criteria Report 2022-01-05
[Table view] |
Text
January 5, 2022 Mr. James Barstow Vice President, Nuclear Regulatory Affairs and Support Services Tennessee Valley Authority 1101 Market Street, LP 4A-C Chattanooga, TN 37402-2801
SUBJECT:
WATTS BAR NUCLEAR PLANT, UNIT 2 - REVIEW OF THE FALL 2020 GENERIC LETTER 95-05 VOLTAGE-BASED ALTERNATE REPAIR CRITERIA REPORT (EPID L-2021-LRO-0003)
Dear Mr. Barstow:
By letter dated July 20, 2021, Tennessee Valley Authority (TVA) submitted Revision 1 of the fall 2020 Generic Letter (GL) 95-05 Voltage-Based Alternate Repair Criteria Report for Watts Bar Nuclear Plant, Unit 2. Revision 1 of the report reflects TVAs response to a request for additional information based on Revision 0 of the report, as well as an NRC-approved license amendment for using site-specific GL 95-05 probability of detection values, and an NRC-approved license amendment for applying a reduced operating temperature to the GL 95-05 methodology.
The NRC staff has completed its review of the information provided and concludes that TVA provided the information required by the Watts Bar Nuclear Plant, Unit 2 technical specifications and that no follow-up is needed at this time. The staffs review summary is enclosed.
If you have any questions, please contact me at 301-415-1627 or via e-mail at Kimberly.Green@nrc.gov.
Sincerely,
/RA/
Kimberly J. Green, Senior Project Manager Plant Licensing Branch II-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-391
Enclosure:
As stated cc: Listserv
REVIEW OF THE FALL 2020 GENERIC LETTER 95-05 VOLTAGE-BASED ALTERNATE REPAIR CRITERIA REPORT TENNESSEE VALLEY AUTHORITY WATTS BAR NUCLEAR PLANT, UNIT 2 DOCKET NO. 50-391 By letter dated July 20, 2021 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML21202A062), Tennessee Valley Authority (the licensee) submitted Revision 1 of the fall 2020 Generic Letter (GL) 95-05 Voltage-Based Alternate Repair Criteria Report for Watts Bar Nuclear Plant (Watts Bar), Unit 2. The corresponding steam generator tube inspections were performed during the third refueling outage (RFO 3) in fall 2020.
Revision 1 of the report reflects the licensees response to a request for additional information based on Revision 0 of the report (ADAMS Accession No. ML21134A225), as well as NRC approval of a license amendment request for using site-specific GL 95-05 probability of detection (POD) values (ADAMS Accession No. ML21027A167), and NRC approval of a license amendment request for applying a reduced operating temperature to the GL 95-05 methodology (ADAMS Accession No. ML21161A239). This report also serves as the licensees operational assessment (OA) for the indications of axial outside diameter stress corrosion cracking (ODSCC) at tube support plate (TSP) intersections evaluated under GL 95-05.
The licensee submitted the report in accordance with Technical Specifications (TS) 5.9.9, Steam Generator Tube Inspection Report, which requires that a report be submitted within 90 days after the initial entry into hot shutdown (MODE 4) following completion of an inspection of the steam generators (SGs) performed in accordance with TS 5.7.2.12, Steam Generator Program. The SG Program, required by TS 5.7.2.12, is to be established and implemented to ensure SG tube integrity is maintained.
This is the first GL 95-05 report submitted for Watts Bar, Unit 2, because these alternate repair criteria were implemented for the first time during RFO 3. The second inspection implementing the GL 95-05 criteria was a mid-cycle inspection (following Cycle 4a), performed in September 2021; a separate GL 95-05 report will be submitted for that inspection.
Based on the review of the information provided, the U.S. Nuclear Regulatory Commission (NRC) staff has the following observations:
The number of distorted support indications (DSIs), which are the bobbin probe indications associated with axial ODSCC at TSP intersections, increased from 155 in the RFO 2 inspection to 1,240 in the RFO 3 inspection. The number of DSIs in RFO 3 were 200, 314, 400, and 326 for SGs 1, 2, 3, and 4, respectively.
Enclosure
Some DSIs detected in RFO 3 had large eddy current voltages. Based on the licensees correlation between DSI voltage and conditional probability of burst (POB), the indication with the largest voltage caused the conditional POB for SG 3 to exceed the GL 95-05 condition monitoring (CM) acceptance criterion. This was reported as NRC Event Notification No. 54994 on November 11, 2020 (https://www.nrc.gov/reading-rm/doc-collections/event-status/event/2020/20201111en.html). The conditional POB and steam line break (SLB) leakage CM acceptance criteria were met for SGs 1, 2, and 4.
Based on the Cycle 4a conditional POB and SLB leakage projections using the site-specific POD values and temperature reduction factor for a planned operating temperature reduction of four degrees Fahrenheit, the licensee concluded the acceptance criteria would be met until the planned start of the mid-cycle inspection outage, with a margin of at least 13 calendar days in the limiting case (POB for SG 3).
The licensee determined voltage growth rates for the Cycle 4a OA projections from DSIs detected in both RFO 2 and RFO 3, precursor signals from lookbacks to the RFO 2 inspection data, and RFO 3 DSIs without prior DSI or precursor signals. The licensee applied the bounding growth rate (SG 3) to all SGs for the OA projections.
The NRC staff also notes that the preliminary mid-cycle inspection results at the end of Cycle 4a, which the licensee described in outage calls with the NRC staff (ADAMS Accession No. ML21279A090), suggest the operating temperature reduction was effective in reducing the growth of axial ODSCC at TSPs. At the time of the outage calls, the licensee reported a total of 1,581 DSIs in the four SGs, compared to the projection of a total of 1,854 DSIs in the Cycle 4a OA (ADAMS Accession No. ML21042B342, Table 7-2). The licensee is required to submit a GL 95-05 report for the Cycle 4a inspection. The SGs are scheduled to be replaced during RFO 4, scheduled to begin in March 2022.
Based on a review of the information provided, the NRC staff concludes that the licensee provided the information required by the Watts Bar, Unit 2 TSs. In addition, the staff concludes that there are no technical issues that warrant additional follow-up action at this time, since the licensee implemented the GL 95-05 voltage-based repair criteria in accordance with the methodology approved in the plant TSs.
ML21350A166 OFFICE NRR/DORL/LPL2-2/PM NRR/DORL/LPL2-2/LA NRR/DNRL/NCSG/BC*
NAME KGreen RButler SBloom DATE 12/16/2021 12/30/2021 12/15/2021 OFFICE NRR/DORL/LPL2-2/BC NRR/DORL/LPL2-2/PM NAME DWrona KGreen DATE 01/05/2022 01/05/2022