ML042680087
| ML042680087 | |
| Person / Time | |
|---|---|
| Site: | Vermont Yankee File:NorthStar Vermont Yankee icon.png |
| Issue date: | 10/13/2004 |
| From: | Richard Ennis NRC/NRR/DLPM/LPD1 |
| To: | Stramback G General Electric Co |
| Ennis R, NRR/DLPM, 415-1420 | |
| References | |
| TAC MC0761 | |
| Download: ML042680087 (7) | |
Text
ENCLOSURE TRANSMITTED HEREWITH CONTAINS PROPRIETARY INFORMATION.
WHEN SEPARATED FROM THE ENCLOSURE, THIS LETTER IS DECONTROLLED WITH RESPECT TO PROPRIETARY INFORMATION.
October 13, 2004 Mr. George B. Stramback Manager, Regulatory Services General Electric Company 175 Curtner Avenue San Jose, CA 95125
SUBJECT:
VERMONT YANKEE NUCLEAR POWER STATION - TECHNICAL AUDIT OF STEAM DRYER ANALYSIS IN SUPPORT OF EXTENDED POWER UPRATE REQUEST (TAC NO. MC0761)
Dear Mr. Stramback:
By letter dated September 10, 2003, Entergy Nuclear Vermont Yankee, LLC and Entergy Nuclear Operations, Inc. (Entergy or the licensee), submitted a proposed license amendment to the U.S. Nuclear Regulatory Commission (NRC) for the Vermont Yankee Nuclear Power Station (Vermont Yankee). The proposed amendment, Technical Specification Proposed Change No. 263, Extended Power Uprate would allow an increase in the maximum authorized power level for Vermont Yankee from 1593 megawatts thermal (MWt) to 1912 MWt.
On August 24 through 26, 2004, the NRC staff conducted a technical audit of the Vermont Yankee steam dryer analysis performed by General Electric (GE) in support of Entergy's request to operate the plant at extended power uprate (EPU) conditions. Staff members from the NRC's Office of Nuclear Reactor Regulation and Office of Nuclear Regulatory Research, and staff contractors from the Argonne National Laboratory conducted the audit of the methodology and supporting calculations for the steam dryer analysis at GE's offices in San Jose, California.
The objective of the audit was to obtain sufficient information to enable the NRC to reach a decision regarding the adequacy of the current analysis of the Vermont Yankee steam dryer in support of the licensees EPU request by: (1) understanding the details of the steam dryer analysis and its supporting calculations; (2) obtaining responses to specific staff questions related to the steam dryer analysis; and (3) learning about any further support for the capability of the steam dryer that might be provided by the licensee in the near future.
Our audit report consists of the enclosed NRC memorandum dated September 14, 2004, including the associated attachment and appendices. The report is being withheld from public disclosure at this time because it may contain proprietary information pursuant to Title 10 of the Code of Federal Regulations Section 2.390. As was discussed with you on September 23, 2004, it was agreed that GE would respond within 30 days of receipt of this letter and submit a bracketed non-proprietary copy of the audit report and affidavit providing the reasons that you consider this information to be proprietary. The NRC staff does not consider the conclusions of the audit to be proprietary and those conclusions are summarized in the following paragraph.
ENCLOSURE TRANSMITTED HEREWITH CONTAINS PROPRIETARY INFORMATION.
WHEN SEPARATED FROM THE ENCLOSURE, THIS LETTER IS DECONTROLLED WITH RESPECT TO PROPRIETARY INFORMATION.
G. Stramback Although the steam dryer performs a non safety-related function, it must maintain its structural integrity to prevent the occurrence of loose parts in the reactor pressure vessel or attached piping systems that could degrade the ability of safety-related components to perform their safety function. Based on review of the information provided in the licensee's application dated September 10, 2003, and supplements received through October 7, 2004 (Supplements 1 through 19), and as augmented by the information discussed during public meetings on July 21, and 22, 2004, and information reviewed during the GE audit, the NRC staff has determined that the licensees analysis provided to date does not demonstrate that the Vermont Yankee steam dryer will remain capable of maintaining its structural integrity under EPU conditions.
Specifically, the analysis of the Vermont Yankee steam dryer as currently submitted in support of Entergy's EPU request:
- 1. has not adequately identified and verified the excitation sources for flow-induced vibration mechanisms that resulted in significant degradation of similar steam dryers at other boiling water reactor nuclear power plants operating at EPU conditions;
- 2. has not provided a complete load definition for the Vermont Yankee steam dryer for EPU conditions in light of several assumptions that have not been adequately justified;
- 3. has not justified the applied methodology as realistic in light of assumptions to account for uncertainties that resulted in apparent significant overestimation of predicted steam dryer stresses;
- 4. might be non-conservative based on assumptions for reducing the stress experienced by steam dryer parts and the creation of new potential fatigue failure locations as a result of modifications to the Vermont Yankee steam dryer; and
- 5. has not validated the extrapolation of pressure peaks from original power levels to EPU conditions for the steam dryer at Vermont Yankee.
If you have any questions, please contact me at 301-415-1420.
Sincerely,
/RA/
Richard B. Ennis, Senior Project Manager, Section VY Project Directorate I Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket No. 50-271
Enclosure:
As stated cc w/o encl: See next page
ENCLOSURE TRANSMITTED HEREWITH CONTAINS PROPRIETARY INFORMATION.
WHEN SEPARATED FROM THE ENCLOSURE, THIS LETTER IS DECONTROLLED WITH RESPECT TO PROPRIETARY INFORMATION.
G. Stramback Although the steam dryer performs a non safety-related function, it must maintain its structural integrity to prevent the occurrence of loose parts in the reactor pressure vessel or attached piping systems that could degrade the ability of safety-related components to perform their safety function. Based on review of the information provided in the licensee's application dated September 10, 2003, and supplements received through October 7, 2004 (Supplements 1 through 19), and as augmented by the information discussed during public meetings on July 21, and 22, 2004, and information reviewed during the GE audit, the NRC staff has determined that the licensees analysis provided to date does not demonstrate that the Vermont Yankee steam dryer will remain capable of maintaining its structural integrity under EPU conditions.
Specifically, the analysis of the Vermont Yankee steam dryer as currently submitted in support of Entergy's EPU request:
- 1. has not adequately identified and verified the excitation sources for flow-induced vibration mechanisms that resulted in significant degradation of similar steam dryers at other boiling water reactor nuclear power plants operating at EPU conditions;
- 2. has not provided a complete load definition for the Vermont Yankee steam dryer for EPU conditions in light of several assumptions that have not been adequately justified;
- 3. has not justified the applied methodology as realistic in light of assumptions to account for uncertainties that resulted in apparent significant overestimation of predicted steam dryer stresses;
- 4. might be non-conservative based on assumptions for reducing the stress experienced by steam dryer parts and the creation of new potential fatigue failure locations as a result of modifications to the Vermont Yankee steam dryer; and
- 5. has not validated the extrapolation of pressure peaks from original power levels to EPU conditions for the steam dryer at Vermont Yankee.
If you have any questions, please contact me at 301-415-1420.
Sincerely, Richard B. Ennis, Senior Project Manager, Section VY Project Directorate I Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket No. 50-271
Enclosure:
As stated cc w/o encl: See next page DISTRIBUTION:
Public REnnis TScarbrough TMadden, OCA PDI-2 Reading DSkay CWu RBores, OCA JDyer WRuland RJasinski CAnderson, RGN-I RBorchardt JStang TJKim, EDO DFlorek, RGN-I BSheron RBarrett CMiller, EDO DPelton, RGN-I TMarsh CGrimes RVirgilio, STP ACRS JLyons EImbro SBurnell, OPA BPoole, OGC CHolden KManoly DScrenci, OPA VBucci, OIG AHowe DTerao NSheehan, OPA ADAMS Accession Number: ML042680087 OFFICE PDI-VY/PM PDI-2/LA EMEB/BC OGC PDI-III/D PDI-VY/SC NAME REnnis CRaynor EImbro BPoole WRuland AHowe DATE 10/12/04 10/5/04 9/28/04 10/5/04 10/12/04 10/12/04 OFFICIAL RECORD COPY
Vermont Yankee Nuclear Power Station cc:
Regional Administrator, Region I U. S. Nuclear Regulatory Commission 475 Allendale Road King of Prussia, PA 19406-1415 Mr. David R. Lewis Shaw, Pittman, Potts & Trowbridge 2300 N Street, N.W.
Washington, DC 20037-1128 Ms. Christine S. Salembier, Commissioner Vermont Department of Public Service 112 State Street Montpelier, VT 05620-2601 Mr. Michael H. Dworkin, Chairman Public Service Board State of Vermont 112 State Street Montpelier, VT 05620-2701 Chairman, Board of Selectmen Town of Vernon P.O. Box 116 Vernon, VT 05354-0116 Operating Experience Coordinator Vermont Yankee Nuclear Power Station 320 Governor Hunt Road Vernon, VT 05354 G. Dana Bisbee, Esq.
Deputy Attorney General 33 Capitol Street Concord, NH 03301-6937 Chief, Safety Unit Office of the Attorney General One Ashburton Place, 19th Floor Boston, MA 02108 Ms. Deborah B. Katz Box 83 Shelburne Falls, MA 01370 Ms. Carla A. White, RRPT, CHP Radiological Health Vermont Department of Health P.O. Box 70, Drawer #43 108 Cherry Street Burlington, VT 05402-0070 Mr. James M. DeVincentis Manager, Licensing Vermont Yankee Nuclear Power Station P.O. Box 0500 185 Old Ferry Road Brattleboro, VT 05302-0500 Resident Inspector Vermont Yankee Nuclear Power Station U. S. Nuclear Regulatory Commission P.O. Box 176 Vernon, VT 05354 Director, Massachusetts Emergency Management Agency ATTN: James Muckerheide 400 Worcester Rd.
Framingham, MA 01702-5399 Jonathan M. Block, Esq.
Main Street P.O. Box 566 Putney, VT 05346-0566 Mr. John F. McCann Director, Nuclear Safety Assurance Entergy Nuclear Operations, Inc.
440 Hamilton Avenue White Plains, NY 10601 Mr. Gary J. Taylor Chief Executive Officer Entergy Operations 1340 Echelon Parkway Jackson, MS 39213
Vermont Yankee Nuclear Power Station cc:
Mr. John T. Herron Sr. VP and Chief Operating Officer Entergy Nuclear Operations, Inc.
440 Hamilton Avenue White Plains, NY 10601 Mr. Danny L. Pace Vice President, Engineering Entergy Nuclear Operations, Inc.
440 Hamilton Avenue White Plains, NY 10601 Mr. Brian OGrady Vice President, Operations Support Entergy Nuclear Operations, Inc.
440 Hamilton Avenue White Plains, NY 10601 Mr. Michael J. Colomb Director of Oversight Entergy Nuclear Operations, Inc.
440 Hamilton Avenue White Plains, NY 10601 Mr. John M. Fulton Assistant General Counsel Entergy Nuclear Operations, Inc.
440 Hamilton Avenue White Plains, NY 10601 Mr. Jay K. Thayer Site Vice President Entergy Nuclear Operations, Inc.
Vermont Yankee Nuclear Power Station P.O. Box 0500 185 Old Ferry Road Brattleboro, VT 05302-0500 Mr. Kenneth L. Graesser 38832 N. Ashley Drive Lake Villa, IL 60046 Mr. James Sniezek 5486 Nithsdale Drive Salisbury, MD 21801 Mr. Ronald Toole 1282 Valley of Lakes Box R-10 Hazelton, PA 18202 Ms. Stacey M. Lousteau Treasury Department Entergy Services, Inc.
639 Loyola Avenue New Orleans, LA 70113 Mr. Raymond Shadis New England Coalition Post Office Box 98 Edgecomb, ME 04556 Mr. James P. Matteau Executive Director Windham Regional Commission 139 Main Street, Suite 505 Brattleboro, VT 05301 Mr. William K. Sherman Vermont Department of Public Service 112 State Street Drawer 20 Montpelier, VT 05620-2601