Letter Sequence Other |
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Initiation
- Request, Request, Request, Request, Request, Request, Request, Request, Request, Request, Request, Request, Request, Request
- Acceptance...
- Supplement, Supplement, Supplement, Supplement, Supplement, Supplement, Supplement, Supplement
Administration
- Meeting, Meeting, Meeting, Meeting, Meeting, Meeting, Meeting, Meeting, Meeting, Meeting, Meeting, Meeting, Meeting, Meeting, Meeting
Results
Other: BVY 06-009, 2006/01/25-Vermont Yankee Nuclear Power Station Applicant'S Environmental Report Operating License Renewal Stage, Appendix E, BVY 06-076, 2006/08/10-Vermont Yankee - License Renewal Application, Amendment 8, BVY 06-079, 2006/08/22-Vermont Yankee License Renewal Application, Amendment 11, BVY 06-083, 2006/09/05-Vermont Yankee License Renewal Application, Amendment 12, BVY 06-095, E-mail: (PA-LR) Copy of SAMA Response, BVY 06-096, 2006/10/20-Vermont Yankee - License Renewal Application, Amendment No. 17, BVY 06-097, 2006/10/31-Vermont Yankee License Renewal Application, Amendment 19, BVY 06-098, E-mail: (PA-LR) Copy of Vhs RAI Response, BVY 07-003, Email: (PA-LR) Vermont Yankee Nuclear Power Station License Renewal Commitment List, Rev. 5, BVY 07-009, License Renewal Application, Amendment 24, BVY 07-018, License Renewal Application, Amendment 26, BVY 07-034, License Renewal Application Annual Update, BVY 07-035, (PA-LR) Bvy 07-035 VY Lr SER Comments, BVY 07-047, License Renewal Application, Amendment 27, Submitted on January 25, 2006, BVY 07-058, License Renewal Application, Amendment 29, BVY 07-062, License Renewal Application, Amendment 30, BVY 07-066, License Renewal Application, Amendment 31, BVY 08-016, (PA-LR) Emailing Bvy 08-016 Final SER Review Comments, BVY 10-069, License Renewal Application Annual Update Information, ML060950195, ML060950215, ML060950218, ML060950220, ML060950224, ML060950235, ML060950250, ML060950258, ML060950262, ML060950269, ML060950271, ML060950277, ML060950279, ML060950284, ML060950290, ML060950301, ML060950311, ML060950323, ML060950328, ML060950331, ML060950347, ML060950351, ML060950356, ML060950364, ML060950370, ML060950372, ML060950375, ML060950540, ML060950549, ML060950559, ML060950567... further results
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MONTHYEARML0629203681987-12-31031 December 1987 VY Annual Ecological Studies of the CT River Report 16-final.pdf Project stage: Other ML0629203651989-12-31031 December 1989 VY Annual Ecological Reports from the 1980's (1989) Project stage: Other ML0609503511998-02-28028 February 1998 GALL AMP: XI.M12, Thermal Aging Embrittlement of Cast Austenitic Stainless Steel (CASS) (Audit Worksheet GALL Report AMP) Project stage: Other BVY 06-009, 2006/01/25-Vermont Yankee Nuclear Power Station Applicant'S Environmental Report Operating License Renewal Stage, Appendix E2006-01-25025 January 2006 2006/01/25-Vermont Yankee Nuclear Power Station Applicant'S Environmental Report Operating License Renewal Stage, Appendix E Project stage: Other ML0609505792006-03-22022 March 2006 GALL AMP: XI.M24, Compressed Air Monitoring (Audit Worksheet GALL Report AMP) Project stage: Other ML0609506202006-03-22022 March 2006 GALL AMP: XI.M31, Reactor Vessel Surveillance (Audit Worksheet GALL Report AMP) Project stage: Other ML0609505962006-03-22022 March 2006 GALL AMP: XI.M27, Fire Water System (Audit Worksheet GALL Report AMP) Project stage: Other ML0609502792006-03-22022 March 2006 GALL AMP: XI.M3, Reactor Head Closure Studs (Audit Worksheet, GALL Report AMP) Project stage: Other ML0609506292006-03-22022 March 2006 GALL AMP: XI.M33, Selective Leaching of Materials (Audit Worksheet GALL Report AMP) Project stage: Other ML0609506372006-03-22022 March 2006 GALL AMP: XI.M36, External Surfaces Monitoring (Audit Worksheet GALL Report AMP) Project stage: Other ML0609502842006-03-22022 March 2006 GALL AMP: XI.M4, BWR Vessel Id Attachment Welds (Audit Worksheet GALL Report AMP) Project stage: Other ML0609502202006-03-22022 March 2006 GALL AMP: X.S1, Concrete Containment Tendon Prestress (Audit Worksheet GALL Report AMP) Project stage: Other ML0610001472006-03-22022 March 2006 GALL AMP: XI.S8, Protective Coating Monitoring and Maintenance Program (Audit Worksheet GALL Report AMP) Project stage: Other ML0610001342006-03-22022 March 2006 GALL AMP: XI.S5, Masonry Wall Progam (Audit Worksheet GALL Report AMP) Project stage: Other ML0609502182006-03-22022 March 2006 GALL AMP: X.M1, Metal Fatigue of Reactor Coolant Pressure Boundary (Audit Worksheet, GALL Report AMP) Project stage: Other ML0609505592006-03-22022 March 2006 GALL AMP: XI.M20, Open-Cycle Cooling Water System (Audit Worksheet GALL Report AMP) Project stage: Other ML0609503472006-03-22022 March 2006 GALL AMP: XI.M11A, Nickel Alloy Penetration Nozzles Welded to the Upper Reactor Vessel Closure Heads of Pressurized Water Reactors Project stage: Other ML0609505402006-03-22022 March 2006 GALL AMP: XI.M18, Bolting Integrity (Audit Worksheet GALL Report AMP) Project stage: Other ML0609505672006-03-22022 March 2006 GALL AMP: XI.M21, Closed-Cycle Cooling Water System (Audit Worksheet GALL Report AMP) Project stage: Other ML0610001012006-03-22022 March 2006 GALL AMP: XI.S2, ASME Section XI, Subsection Iwl (Audit Worksheet GALL Report AMP) Project stage: Other ML0609505732006-03-22022 March 2006 GALL AMP: XI.M23, Inspection of Overhead Heavy Load and Light Load (Related to Refueling) Handling Systems (Audit Worksheet GALL Report AMP) Project stage: Other ML0609506102006-03-22022 March 2006 GALL AMP: XI.M29, Aboveground Steel Tanks (Audit Worksheet GALL Report AMP) Project stage: Other ML0609502902006-03-22022 March 2006 GALL AMP: XI.M5, BWR Feedwater Nozzle (Audit Worksheet, GALL Report AMP) Project stage: Other ML0610001382006-03-22022 March 2006 GALL AMP: XI.S6, Structures Monitoring Program (Audit Worksheet GALL Report AMP) Project stage: Other ML0610001262006-03-22022 March 2006 GALL AMP: XI.S4, 10 CFR 50, Appendix J (Audit Worksheet GALL Report AMP) Project stage: Other ML0609502242006-03-22022 March 2006 GALL AMP: XI.E1, Electrical Cables and Connections Not Subject to 10 CFR 50.49 Environmental Qualification Requirements (Audit Worksheet GALL Report AMP) Project stage: Other ML0609506062006-03-22022 March 2006 GALL AMP: XI.M28, Buried Piping and Tanks Surveillance (Audit Worksheet GALL Report AMP) Project stage: Other ML0609502152006-03-22022 March 2006 GALL AMP: X.E1. Environmental Qualification (EQ) of Electric Components (Audit Worksheet GALL Report AMP) Project stage: Other ML0609503752006-03-22022 March 2006 GALL AMP: XI.M17, Flow-Accelerated Corrosion (Audit Worksheet GALL Report AMP) Project stage: Other ML0610000782006-03-22022 March 2006 GALL AMP: XI.M38, Inspection of Internal Surfaces in Miscellaneous Piping and Ducting Components (Audit Worksheet GALL Report AMP) Project stage: Other ML0609505702006-03-22022 March 2006 GALL AMP: XI.M22, Boraflex Monitoring (Audit Worksheet GALL Report AMP) Project stage: Other ML0609503722006-03-22022 March 2006 GALL AMP: XI.M16, PWR Vessel Internals (Audit Worksheet GALL Report AMP) Project stage: Other ML0609503642006-03-22022 March 2006 GALL AMP: XI.M14, Loose Part Monitoring (Audit Worksheet GALL Report AMP) Project stage: Other ML0609502772006-03-22022 March 2006 GALL AMP: XI.M2, Water Chemistry (Audit Worksheet, GALL Report AMP) Project stage: Other ML0609506242006-03-22022 March 2006 GALL AMP: XI.M32, One-Time Inspection (Audit Worksheet GALL Report AMP) Project stage: Other ML0609503112006-03-22022 March 2006 GALL AMP: XI.M7, BWR Stress Corrosion Cracking (Audit Worksheet GALL Report AMP) Project stage: Other ML0609502352006-03-22022 March 2006 GALL AMP: XI.E2, Electrical Cables and Connections Not Subject to 10 CFR 50.49 Environmental Qualification Requirements Used in Instrumentation Circuits (Audit Worksheet GALL Report AMP) Project stage: Other ML0609506342006-03-22022 March 2006 GALL AMP: XI.M35, One-Time Inspection of ASME Code Class 1 Small Bore Piping (Audit Worksheet GALL Report AMP) Project stage: Other ML0609502502006-03-22022 March 2006 GALL AMP: XI.E3, Inaccessible Medium-Voltage Cables Not Subject to 10 CFR 50.49 Environmental Qualification Requirements (Audit Worksheet GALL Report AMP) Project stage: Other ML0610001432006-03-22022 March 2006 GALL AMP: XI.S7, Rg 1.127, Inspection of Water-Control Structures Associated with Nuclear Power Plants (Audit Worksheet GALL Report AMP) Project stage: Other ML0609505492006-03-22022 March 2006 GALL AMP: XI.M19, Steam Generator Tube Integrity (Audit Worksheet GALL Report AMP) Project stage: Other ML0609505872006-03-22022 March 2006 GALL AMP: XI.M26, Fire Protection (Audit Worksheet GALL Report AMP) Project stage: Other ML0609501952006-03-22022 March 2006 GALL AMP: Plant-Specific (Audit Worksheet - GALL Report AMP) Project stage: Other ML0609503702006-03-22022 March 2006 GALL AMP: XI.M15, Neutron Noise Monitoring (Audit Worksheet GALL Report AMP) Project stage: Other ML0609503012006-03-22022 March 2006 GALL AMP: XI.M6, BWR Control Rod Drive Return Line Nozzle (Audit Worksheet GALL Report AMP) Project stage: Other ML0609503282006-03-22022 March 2006 GALL AMP: XI.M9, BWR Vessels Internals (Audit Worksheet GALL Report AMP) Project stage: Other ML0610000962006-03-22022 March 2006 GALL AMP: XI.S1, ASME Section XI, Subsection IWE (Audit Worksheet GALL Report AMP) Project stage: Other ML0609502692006-03-22022 March 2006 GALL AMP: XI.E6, Electrical Cable Connections Not Subject to 10 CFR 50.49 Environmental Qualification Requirements (Audit Worksheet, GALL Report AMP) Project stage: Other ML0609502622006-03-22022 March 2006 GALL AMP: XI.E5, Fuse Holder (Audit Worksheet GALL Report AMP) Project stage: Other ML0609503312006-03-22022 March 2006 GALL AMP: XI.M10, Boric Acid Corrosion (Audit Worksheet GALL Report AMP) Project stage: Other 1998-02-28
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Category:Letter type:BVY
MONTHYEARBVY 24-005, Report of Investigation Pursuant to 10 CFR 20, Appendix G2024-01-30030 January 2024 Report of Investigation Pursuant to 10 CFR 20, Appendix G BVY 24-004, Report of Investigation Pursuant to 10 CFR 20, Appendix G2024-01-23023 January 2024 Report of Investigation Pursuant to 10 CFR 20, Appendix G BVY 24-003, Nuclear Onsite Property Damage Insurance2024-01-0404 January 2024 Nuclear Onsite Property Damage Insurance BVY 24-001, Pre-Notice of Disbursement from Decommissioning Trust2024-01-0202 January 2024 Pre-Notice of Disbursement from Decommissioning Trust BVY 23-030, Report of Investigation Pursuant to 10 CFR 20, Appendix G2023-12-20020 December 2023 Report of Investigation Pursuant to 10 CFR 20, Appendix G BVY 23-029, Proof of Financial Protection2023-12-12012 December 2023 Proof of Financial Protection BVY 23-028, Pre-Notice of Disbursement from Decommissioning Trust2023-11-28028 November 2023 Pre-Notice of Disbursement from Decommissioning Trust BVY 23-027, Report of Investigation Pursuant to 10 CFR 20, Appendix G2023-11-21021 November 2023 Report of Investigation Pursuant to 10 CFR 20, Appendix G BVY 23-026, Report of Investigation Pursuant to 10 CFR 20, Appendix G2023-11-13013 November 2023 Report of Investigation Pursuant to 10 CFR 20, Appendix G BVY 23-025, Pre-Notice of Disbursement from Decommissioning Trust2023-11-0202 November 2023 Pre-Notice of Disbursement from Decommissioning Trust BVY 23-023, License Amendment Request Addition of License Condition 3.K, License Termination Plan; Proposed Change No. 3172023-10-10010 October 2023 License Amendment Request Addition of License Condition 3.K, License Termination Plan; Proposed Change No. 317 BVY 23-022, Pre-Notice of Disbursement from Decommissioning Trust2023-08-23023 August 2023 Pre-Notice of Disbursement from Decommissioning Trust BVY 23-020, Pre-Notice of Disbursement from Decommissioning Trust2023-08-0202 August 2023 Pre-Notice of Disbursement from Decommissioning Trust BVY 23-021, Report of Investigation Pursuant to 10 CFR 20, Appendix G2023-08-0202 August 2023 Report of Investigation Pursuant to 10 CFR 20, Appendix G BVY 23-019, Update to 2022 Radiological Effluent Release Report2023-07-24024 July 2023 Update to 2022 Radiological Effluent Release Report BVY 23-018, Update to Nuclear Onsite Property Damage Insurance2023-07-12012 July 2023 Update to Nuclear Onsite Property Damage Insurance BVY 23-017, Pre-Notice of Disbursement from Decommissioning Trust2023-06-29029 June 2023 Pre-Notice of Disbursement from Decommissioning Trust BVY 23-016, 10 CFR 72.48 Report2023-06-0505 June 2023 10 CFR 72.48 Report BVY 23-015, Report of Investigation Pursuant to 1O CFR 20, Appendix G2023-06-0505 June 2023 Report of Investigation Pursuant to 1O CFR 20, Appendix G BVY 23-014, Pre-Notice of Disbursement from Decommissioning Trust2023-05-31031 May 2023 Pre-Notice of Disbursement from Decommissioning Trust BVY 23-013, 2022 Radiological Environmental Operating Report2023-05-10010 May 2023 2022 Radiological Environmental Operating Report BVY 23-011, 2022 Radiological Effluent Release Report2023-05-10010 May 2023 2022 Radiological Effluent Release Report BVY 23-012, Pre-Notice of Disbursement from Decommissioning Trust2023-05-0202 May 2023 Pre-Notice of Disbursement from Decommissioning Trust BVY 23-009, 2022 Individual Monitoring NRC Form 5 Report2023-04-24024 April 2023 2022 Individual Monitoring NRC Form 5 Report BVY 23-008, Pre-Notice of Disbursement from Decommissioning Trust2023-04-0606 April 2023 Pre-Notice of Disbursement from Decommissioning Trust BVY 23-006, Status of Decommissioning and Spent Fuel Management Fund for Year Ending 20222023-03-29029 March 2023 Status of Decommissioning and Spent Fuel Management Fund for Year Ending 2022 BVY 23-007, Report of Investigation Pursuant to 10 CFR 20, Appendix G2023-03-29029 March 2023 Report of Investigation Pursuant to 10 CFR 20, Appendix G BVY 23-005, Nuclear Onsite Property Damage Insurance2023-03-13013 March 2023 Nuclear Onsite Property Damage Insurance BVY 23-004, Pre-Notice of Disbursement from Decommissioning Trust2023-03-0202 March 2023 Pre-Notice of Disbursement from Decommissioning Trust BVY 23-003, Pre-Notice of Disbursement from Decommissioning Trust2023-01-31031 January 2023 Pre-Notice of Disbursement from Decommissioning Trust BVY 22-030, Documentary Evidence of Performance Bond2022-12-30030 December 2022 Documentary Evidence of Performance Bond BVY 22-028, Re Proof of Financial Protection2022-11-28028 November 2022 Re Proof of Financial Protection BVY 22-027, Bvy 22-027; Pre-Notice of Disbursement from Decommissioning Trust for Vermont Yankee Nuclear Power Station2022-11-11011 November 2022 Bvy 22-027; Pre-Notice of Disbursement from Decommissioning Trust for Vermont Yankee Nuclear Power Station BVY 22-026, Pre-Notice of Disbursement from Decommissioning Trust2022-10-31031 October 2022 Pre-Notice of Disbursement from Decommissioning Trust BVY 22-025, Pre-Notice of Disbursement from Decommissioning Trust2022-10-0404 October 2022 Pre-Notice of Disbursement from Decommissioning Trust BVY 22-023, Pre-Notice of Disbursement from Decommissioning Trust2022-09-0101 September 2022 Pre-Notice of Disbursement from Decommissioning Trust BVY 22-022, Report of Investigation Pursuant to 10 CFR 20, Appendix G2022-08-22022 August 2022 Report of Investigation Pursuant to 10 CFR 20, Appendix G BVY 22-021, Report of Investigation Pursuant to 10 CFR 20, Appendix G2022-08-16016 August 2022 Report of Investigation Pursuant to 10 CFR 20, Appendix G BVY 22-020, Pre-Notice of Disbursement from Decommissioning Trust2022-08-0101 August 2022 Pre-Notice of Disbursement from Decommissioning Trust BVY 22-019, Pre-Notice of Disbursement from Decommissioning Trust2022-07-0606 July 2022 Pre-Notice of Disbursement from Decommissioning Trust BVY 22-013, Notification of Revised Decommissioning Cost Estimate2022-06-17017 June 2022 Notification of Revised Decommissioning Cost Estimate BVY 22-018, Pre-Notice of Disbursement from Decommissioning Trust2022-06-0808 June 2022 Pre-Notice of Disbursement from Decommissioning Trust BVY 22-015, 2021 Radiological Environmental Operating Report2022-05-0505 May 2022 2021 Radiological Environmental Operating Report BVY 22-017, Pre-Notice of Disbursement from Decommissioning Trust2022-05-0505 May 2022 Pre-Notice of Disbursement from Decommissioning Trust BVY 22-014, 2021 Radiological Effluent Release Report2022-04-28028 April 2022 2021 Radiological Effluent Release Report BVY 22-012, Biennial Report for Quality Assurance Program Manual Changes Under 10 CFR 50.54(a)(3), 10 CFR 71.106, and 10 CFR 72.140(d)2022-04-12012 April 2022 Biennial Report for Quality Assurance Program Manual Changes Under 10 CFR 50.54(a)(3), 10 CFR 71.106, and 10 CFR 72.140(d) BVY 22-011, Pre-Notice of Disbursement from Decommissioning Trust2022-04-0404 April 2022 Pre-Notice of Disbursement from Decommissioning Trust BVY 22-009, Status of Decommissioning and Spent Fuel Management Fund for the Year Ending 20212022-03-23023 March 2022 Status of Decommissioning and Spent Fuel Management Fund for the Year Ending 2021 BVY 22-008, Pre-Notice of Disbursement from Decommissioning Trust2022-02-24024 February 2022 Pre-Notice of Disbursement from Decommissioning Trust BVY 22-005, ISFSI Decommissioning Funding Plan2022-02-24024 February 2022 ISFSI Decommissioning Funding Plan 2024-01-04
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Entergy Nuclear Operations, Inc.Vermont Yankee P.O. Box 0500 185 Old Ferry Road Brattleboro, VT 05302-0500 Tel 802 257 5271 September 27, 2007 Docket No. 50-271 BVY 07-062 TAC No. MC 9668 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001
Reference:
Subject:
- 1. Letter, Entergy to USNRC, "Vermont Yankee Nuclear Power Station, License No. DPR-28, License Renewal Application," BVY 06-009, dated January 25, 2006.2. Letter, USNRC to Entergy, "Request for Additional Information for the Review of the Vermont Yankee Nuclear Power Station, License Renewal Application," NVY 07-121, dated August 29, 2007.Vermont Yankee Nuclear Power Station License No. DPR-28 (Docket No. 50-271)License Renewal Application, Amendment 30 On January 25, 2006, Entergy Nuclear Operations, Inc. and Entergy Nuclear Vermont Yankee, LLC (Entergy) submitted the License Renewal Application (LRA) for the Vermont Yankee Nuclear Power Station (VYNPS) as indicated by Reference
- 1. Subsequent to an event that occurred at VYNPS on August 21, 2007, the NRC issued a "Request for Additional Information" (RAI) as indicated by Reference 2 as appropriate to clarify information contained within the LRA.This letter is submitted to provide our response to questions detailed in RAI 2.4.4-2.Should you have any questions concerning this letter, please contact Mr. Dave Mannai at (802)258-5422.I declare under penalty of perjury that the foregoing is true and correct, executed on September 27, 2007.Since rely, Site Yaike Nresident Vermont Yankee Nuclear Power Station cc: See next page enc: Attachment 1 4 ulr' BVY 07-062 Docket No. 50-271 cc: Mr. James Dyer, Director U.S. Nuclear Regulatory Commission Office 05E7 Washington, DC 20555-00001 Mr. Samuel J. Collins, Regional Administrator U.S. Nuclear Regulatory Commission, Region 1 475 Allendale Road King of Prussia, PA 19406-1415 Mr. Jack Strosnider, Director U.S. Nuclear Regulatory Commission Office T8A23 Washington, DC 20555-00001 Mr. Jonathan Rowley, Senior Project Manager U.S. Nuclear Regulatory Commission 11555 Rockville Pike MS-O-1 1 F1 Rockville, MD 20853 Mr. Mike Modes USNRC RI 475 Allendale Rd, King of Prussia, PA 19406 Mr. James S. Kim, Project Manager U.S. Nuclear Regulatory Commission Mail Stop 0 8 C2A Washington, DC 20555 USNRC Resident Inspector Entergy Nuclear Vermont Yankee, LLC P.O. Box 157 (for mail delivery)Vernon, Vermont 05354 Mr. David O'Brien, Commissioner VT Department of Public Service 112 State Street -Drawer 20 Montpelier, Vermont 05620-2601 Diane Curran, Esq.Harmon, Curran, Spielberg
& Eisenberg, LLP 1726 M Street, N.W., Suite 600 Washington, D.C. 20036 BVY 07-062 Docket No. 50-271 Attachment 1 Vermont Yankee Nuclear Power Station License Renewal Application Amendment 30 RAI 2.4.4-2 Response VERMONT YANKEE NUCLEAR POWER STATION LICENSE RENEWAL APPLICATION SUPPLEMENT ATTACHMENT I RAI 2.4.4-2 Please provide the results of the review performed to determine the impact of the circulating water piping, pipe supports, and west cooling tower cell (2-4) failures on license renewal scoping, screening, and applicable aging management programs.Please include the following:
A. A conclusion and basis as to whether the scoping results documented in the LRA, which initially determined that 9 of the 11 west cooling tower cells were not within the scope of license renewal, are still valid.B. If found that the west cooling tower cells are within the scope of license renewal, please provide the following:
- 1. The potential effect of a circulating water piping, pipe supports, or structural failure of the nonsafety-related west cooling tower cells (2-3 through 2-11), which were not included within the scope of license renewal, on safety-related systems, structures, and components (in accordance with 10 CFR 54.4(a)(2)).
Include the potential effect of debris entering the deep basin beneath the cooling tower.I1. The details of any age related degradation which caused the failure of the circulating water piping, pipe supports, and west cooling tower cell.Include the results of the piping and pipe supports inspection related to the current failure and any previously performed, and a description of the identified aging mechanism(s).
C. Any impact on the aging management programs for circulating water piping, pipe supports, or cooling tower cells.Cooling Tower Background Information VYNPS utilizes once-through condenser cooling from the Connecticut River supplemented by two forced draft cooling towers. Each tower consists of eleven cells, each cell equipped with its own forced draft fan. One cell, CT 2-1, of the west cooling tower also provides cooling to the RHR service water system in the alternate cooling system mode and is consequently safety-related.
Cell CT 2-2, the cell adjacent to CT 2-1, is designed and constructed as a Seismic Class I structure to prevent adverse impact to CT 2-1 in the event of a seismic event.Safety-related cooling tower cell CT 2-1 and Seismic Class I CT 2-2 structures have similar construction as the other cooling tower cells for dead weight loads, but a more robust bracing system to withstand wind and seismic loading. They are constructed from high quality timber and use stainless steel hardware for all bolted connections.
The structural columns had been refurbished during the 1980's, with subsequent end wall refurbishment between 2002 and 2007. As required for activities associated with any safety-related and Seismic Class I SSC, the inspections and repairs on cooling tower cells CT 2-1 and CT 2-2 receive additional oversight by site Engineering, Maintenance, and Quality Assurance (QA) groups.Page 1 of 4 BVY 07-062 Docket 50-271 VERMONT YANKEE NUCLEAR POWER STATION LICENSE RENEWAL APPLICATION SUPPLEMENT ATTACHMENT 1 RAI 2.4.4-2.A A conclusion and basis as to whether the scoping results documented in the LRA, which initially determined that 9 of the 11 west cooling tower cells were not within the scope of license renewal, are still valid.Response to Part A: Cooling tower cells CT 2-1 and CT 2-2 are the only cells in the scope of license renewal.Failures of the other cells will not prevent satisfactory accomplishment of a safety function identified in 10 CFR 54.4(a)(1).
The scoping results documented in the LRA remain valid. See response to part B for further discussion of potential failures.RAI 2.4.4-2.B If found that the west cooling tower cells are within the scope of license renewal, please provide the following:
- 1. The potential effect of a circulating water piping, pipe supports, or structural failure of the nonsafety-related west cooling tower cells (2-3 through 2-11), which were not included within the scope of license renewal, on safety-related systems, structures, and components (in accordance with 10 CFR 54.4(a)(2)).
Include the potential effect of debris entering the deep basin beneath the cooling tower.II. The details of any age related degradation which caused the failure of the circulating water piping, pipe supports, and west cooling tower cell.Include the results of the piping and pipe supports inspection related to the current failure and any previously performed, and a description of the identified aging mechanism(s).
Response to Part B Subpart I: As indicated in the LRA and in response to Part A, west cooling tower cells CT 2-1 and CT 2-2 are within the scope of license renewal. The failure of cooling tower cell CT 2-4 or any other of the cooling tower cells, along with the associated circulating water piping and pipe supports has no impact on the ability of the in-scope cooling tower cells and the Cooling Tower No. 2 deep basin to accomplish safety functions under design basis conditions.
Cooling tower cells CT 2-1 and CT 2-2 are seismically designed to ensure that they are not adversely affected by a seismic event or by failure of other cooling tower cells. This design includes "breakaway" connections to the remaining cooling tower cells.The cooling tower basin has a storage capacity of 1.45 million gallons, which is sufficient for 7 days of alternate cooling system (ACS) operation.
The available capacity assumes that cooling tower cells CT 2-3 through CT 2-9 collapse during a seismic event resulting in an estimated 170,427 gallons of water (equivalent to the volume of all material in Page 2 of 4 BVY 07-062 Docket 50-271 VERMONT YANKEE NUCLEAR POWER STATION LICENSE RENEWAL APPLICATION SUPPLEMENT ATTACHMENT I these cells) being displaced (lost). The evaluation does not credit the volume of water in basin below cooling tower cells CT 2-10 and CT 2-11.The potential for debris blockage of the ACS suction following an event involving collapse of cooling tower cells CT 2-3 through CT 2-11 has also been evaluated.
The velocity through the suction grating at an ACS flow rate of 8000 gpm is 0.25 ft/sec which is 10% of the velocity required to keep sediment in suspension.
This low velocity coupled with the tower cross bracing in two directions will prevent migration of debris to the ACS suction.Failure of cooling tower cells CT 2-3 through CT 2-11 (9 of 11 cells) and associated components has no impact on safety-related cooling tower cell CT 2-1.Subpart II: As identified in the VYNPS LRA, the aging effects on the cooling tower wooden structures are a) change in material properties, b) cracking, and c) loss of material.
The aging mechanisms associated with the partial failure of CT 2-4 are iron salt attack (formation of iron salts in the wood where ferrous hardware contacts the lumber and degrades the wood cells), fungal attack (wood destroying microscopic organism called decay fungi that forms in wood exposed to suitable temperature 40 0 F-140'F in moist environment), and repeated wetting and drying cycles causing wood checking and physical damage which reduces wood strength.The circulating water piping within the cooling tower is made of fiberglass and is secured in wooden support saddles. The piping separation event that occurred resulted from distribution deck sag that caused the bell/spigot joint to separate.
It did not result from the effects of aging on the fiberglass piping. The wooden saddles supporting the distribution header were found in good condition with no significant degradation.
The supporting columns for the circulating water header experienced a reduction in strength due to iron salt attack and fungal attack at the upper spliced joints that caused cracking.
This caused the initial failure of several support columns which led to deck sag and separation of the fiberglass circulating water piping joint. This separation increased local water loading and caused additional column failures which lead to the partial CT 2-4 failure.RAI 2.4.4-2.C Any impact on the aging management programs for circulating water piping, pipe supports, or cooling tower cells.Response to Part C: The circulating water piping separated due to the initial CT 2-4 column failure, rather than due to the effects of aging. Consequently, the failure does not indicate a need for change to the aging management programs for the circulating water piping. Thus, there is no impact on the aging management programs for circulating water piping.Page 3 of 4 BVY 07-062 Docket 50-271 VERMONT YANKEE NUCLEAR POWER STATION LICENSE RENEWAL APPLICATION SUPPLEMENT ATTACHMENT 1 Aging effects identified in the VYNPS LRA for the cooling tower structural elements are loss of material, cracking and change in material properties.
These aging effects are consistent with those associated with the failure of CT 2-4. The LRA identifies a need for enhancement to the Structures Monitoring Program to add guidance for performing examinations of wood cooling tower elements to identify loss of material, cracking, and change in material properties.
This enhancement will include details for examination and acceptance criteria for wood structures and structural components (i.e., columns and circulating water pipe supports) to ensure aging effects are identified and corrected prior to loss of intended function.
To detect change in material properties, the enhancement will entail inspections that are more involved than remote visual surface inspections.
Lessons learned from review of the failure of CT 2-4 will be considered in implementation of the enhancement identified for the Structures Monitoring Program.Page 4 of 4 BVY 07-062 Docket 50-271