Letter Sequence Response to RAI |
---|
|
|
MONTHYEARML11145A1632011-05-20020 May 2011 Revised Response to Request for Additional Information Question 3 Regarding Final Safety Analysis Report Section 2.4 Project stage: Response to RAI ML11241A1662012-01-25025 January 2012 Tennessee Valley Authority Long-Term Hydrology Issues for Operating Nuclear Plants - Browns Ferry Nuclear Plant, Units 1, 2, and 3; Sequoyah Nuclear Plant, Units 1 and 2; and Watts Bar Nuclear Plant, Unit 1 Project stage: Other 2011-05-20
[Table View] |
|
---|
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] |
Text
Tennessee Valley Authority, Post Office Box 2000, Spring City, Tennessee 37381-2000 May 20, 2011 10 CFR 50.4 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555-0001 Tennessee Valley Authority, Watts Bar Nuclear Plant, Unit 2 Docket No. 50-391
Subject:
Revised Response to Request for Additional Information Question 3 Regarding Final Safety Analysis Report Section 2.4 (TAC NO. ME3945)
Reference:
Letter from TVA to NRC, "Response to Request for Additional Information Regarding Final Safety Analysis Report Section 2.4 (TAC NO. ME3945)," dated April 20, 2011 By the referenced letter, the Tennessee Valley Authority (TVA) provided response to the Request for Additional Information (RAI) regarding Final Safety Analysis Report (FSAR) Section 2.4. Based on TVA's response, a follow-up phone call between the NRC and TVA was held on May 4, 2011. As a result of the call, a revised response to RAI question 3 ý,as required. Enclosure 1 to this letter provides TVA's revised response to RAI question 3. This response supersedes the response to RAI question 3 submitted in the referenced letter.
Regarding the RAI question 2 response submitted in the referenced letter, TVA agreed to revise FSAR Figure 2.4-72 to show the sand baskets. An FSAR Change Request has been submitted to include this revision in FSAR Amendment 104. A copy of the Figure submitted with the Change Request is provided in Enclosure 2.
Note 3 was added to Figure 2.4-72 to describe the sand baskets.
In addition, TVA agreed during the follow-up phone call that completion of the Cherokee and Douglas dams finite element analysis as discussed in RAI response question 2 and the date for permanent modification resolution to address each of the sand basket installations as discussed in RAI response question 4, would be license conditions.
U.S. Nuclear Regulatory Commission Page 2 May 20, 2011 There are no new commitments described in this submittal. If you have any questions, please contact Bill Crouch at (423) 365-2004.
I declare under penalty of perjury that the foregoing is true and correct. Executed on the 20th day of May, 2011.
Respectfully, David Stinson Watts Bar Unit 2 Vice President
Enclosures:
- 1. Revised Response to Request for Additional Information Question 3 Regarding Final Safety Analysis Report Section 2.4
- 2. Revised FSAR Figure 2.4-72 cc (Enclosures):
U.S. Nuclear Regulatory Commission Region II Marquis One Tower 245 Peachtree Center Ave., N.E., Suite 1200 Atlanta, GA 30303-1257 NRC Resident Inspector Unit 2 Watts Bar Nuclear Plant 1260 Nuclear Plant Road Spring City, TN 37381
ENCLOSURE1 REVISED RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION QUESTION 3 REGARDING FINAL SAFETY ANALYSIS REPORT SECTION 2.4 TENNESSEE VALLEY AUTHORITY DOCKET NO. 50-391 By letter dated May 7,2010, Tennessee Valley Authority (TVA) providedAmendment 98 to the Watts Bar Nuclear Plant(WBN), Unit 2, FinalSafety Analysis Report (FSAR).
In Amendment 98, TVA included information in Section 2.4, "HydrologicEngineering."
In a letter dated January24, 2011, TVA also provided anticipatedchanges to FSAR Section 2.4 in advance of FSAR Amendment 103, to facilitate the continuing review by the NuclearRegulatory Commission (NRC) staff. In the discussionin FSAR Subsection 2.4.3 regardingprobablemaximum flood (PMF)on streams and rivers, the staff finds that TVA makes no mention that the predictedPMFlevel is dependent on temporary modification currently in place where sand baskets about 4 feet in height are deployed in the vicinity of four dams (FortLoudoun, Tellico, Cherokee and Watts
.Bar). Thus, the NRC staff requests the following additionalinformation in orderto continue its review:
- 3. NRC Request:
Discuss the basis for concluding the structuraladequacy of the sand baskets under either scenarios of temporary or long-term deployment. Specifically, address the ability of the sand baskets to withstand debris, erosion and impact loading caused by tornado, hurricane, or large moving objects such as trucks.
TVA Response:
The sand baskets installed on embankments at the Cherokee, Fort Loudoun, Tellico and Watts Bar dams are designed for loading conditions that are consistent with the loading conditions used in the design of the dam concrete structures and embankments at these facilities. For the PMF and the seismic-flood events, the sand baskets are designed for the lateral hydrostatic loads resulting from the peak headwater conditions, the uplift pressure on the base of the baskets and the deadweight of the sand baskets. The sand baskets are shown to be stable against sliding by demonstrating that the frictional resistance at the basket/surface interface multiplied by the vertical forces on the base of the sand basket exceeds the applied lateral hydrostatic forces with a minimum factor of safety of 1.1 in accordance with USACE EM 1110-2-2100 for extreme conditions. Sand baskets are shown to be stable against overturning by demonstrating that the resisting moment provided by the deadweight of the baskets exceeds the overturning moment associated with the lateral hydrostatic forces and the uplift pressure on the base of the sand baskets. For the seismic-flood events evaluated, none of the sand baskets are credited except at Fort Loudoun dam.
The Fort Loudoun dam sand baskets are designed for the top-of-embankment horizontal and vertical base accelerations for the seismic event under consideration plus deadweight.
For this loading condition, the sand baskets are shown to be stable against sliding by demonstrating that the frictional resistance at the basket/surface interface multiplied by the E1-1
basket deadweight minus the vertical seismic load exceeds the horizontal seismic inertia loads with a minimum factor of safety of 1.1 in accordance with USACE EM 1110-2-2100 for extreme conditions. Sand baskets are shown to be stable against overturning by demonstrating the resisting moment provided by the deadweight of the sand baskets exceeds the overturning moments associated with the seismic uplift and horizontal inertia loads. Since the respective reservoir headwaters have not reached the base of the sand baskets at the time of the seismic event, no hydrostatic loads are combined with the seismic loading on the baskets.
As discussed above, stability calculations were performed by TVA for the sand baskets using vendor test data for sliding resistance. The stability analysis demonstrated an acceptable factor of safety in sliding for each installation. Based on sand basket vendor estimation of a design life of between 5 and 7 years, the sand baskets can perform their intended function until decisions are made relative to the long-term solution for preventing embankment overflow.
Vendor (HESCO Concertainers) information regarding the ability of the sand baskets to withstand debris and impact loading was provided in TVAs letter to the NRC dated January 14, 2011, "Response to Hydrology Action Items."
Since water does not overtop the sand baskets under PMF conditions, a large sand basket base erosion mechanism does not exist. Testing performed by the sand basket vendor and reviews of the performance of similar sand baskets in the 2009 Fargo, North Dakota flood did not identify sliding or stability concerns resulting from seepage through the baskets. As described in the response to Question 1, the sand baskets are considered to fail when overtopped during the Norris, Cherokee, Douglas and Tellico seismic-flood failure combination.
Consistent with the design of the dam concrete structures and embankments, impact loading caused by tornado, hurricane or large moving objects, such as trucks, is not evaluated in the sand basket structural adequacy calculations. However, should tornado, hurricane or large moving object (such as a land-based truck) impact cause damage to sand baskets, inspections by TVA personnel within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> after these events would detect the damage, and the appropriate repairs would be implemented. Sand basket impact from larger moving objects (such as trucks) in flood conditions is not considered since the driving water flow through the reservoirs would carry such objects to the discharge points of the reservoirs.
Any general degradation of the sand baskets would be detected during the routine periodic inspection by TVA personnel and would be repaired to vendor specifications.
E1-2
ENCLOSURE 2 REVISED FSAR FIGURE 2.4-72 E2-1
oq qO.?g 04 04; 0(6,009 0./Ip W See Note'3 Zse*" &W AV,01404v's
- 3, improvements have increased the effective height of the
& ~'embankment to a minimum El 0!22j Il0- r h.P 836 (See Fort Loudflun Project
~4.30,C.0 Drawing 10W222-1). Field
(/77 ~'~AS$1UO A~i*tAhV.Yl surveys indicate a minimum
- 770n ,height of El 836.9 was achieved.
- " MCLE tEl 730 'UrFSAR Amwadmwc i FINAL SAMFTV TYP/CAL C~AKAEYrT $WT/O//
rFrt Ofa Fzwr£aI32.472