ML081890489
| ML081890489 | |
| Person / Time | |
|---|---|
| Site: | Monticello  |
| Issue date: | 07/11/2008 |
| From: | Tam P NRC/NRR/ADRO/DORL/LPLIII-1 |
| To: | O'Connor T Nuclear Management Co |
| tam P, NRR/ADRO/DORL, 415-1451 | |
| References | |
| TAC MD6854 | |
| Download: ML081890489 (7) | |
Text
July 11, 2008 Mr. Timothy J. O=Connor Site Vice President Monticello Nuclear Generating Plant Nuclear Management Company, LLC 2807 West County Road 75 Monticello, MN 55362-9637
SUBJECT:
MONTICELLO NUCLEAR GENERATING PLANT (MNGP) - CORRECTION OF ERRORS IN SAFETY EVALUATION ASSOCIATED WITH RELIEF REGARDING LIMITED ULTRASONIC EXAMINATION COVERAGE OF FIVE WELDS (TAC NO. MD6854)
Dear Mr. OConnor:
By letter dated September 26, 2007, as supplemented by letter dated March 21, 2008, Nuclear Management Company (NMC) submitted Relief Request No. 15, seeking relief from the requirements of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code to allow limited ultrasonic test examination coverage at MNGP. By letter dated May 19, 2008, the Nuclear Regulatory Commission staff granted the requested relief.
Subsequently, Ms. Lynne Gunderson of your staff pointed out two errors in the safety evaluation (SE) associated with the relief. We agree that errors have been made in the SE. Enclosed please find two replacement pages as follows: (1) The bottom two lines of Page 4 are corrected by changing Section X, from the 1999 edition to Section XI, from the 1998 edition. The top of Page 8 contains unnecessary text (i.e., redundant lines from the last paragraph on Page 7) and is corrected by deleting those lines.
The corrections do not change the conclusion reached by the SE. We apologize for any inconvenience these errors may have caused you.
Sincerely,
/RA/
Peter S. Tam, Senior Project Manager Plant Licensing Branch III-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-263
Enclosures:
As stated cc w/encl: See next page
ML081890489 OFFICE NRR/LPL3-1/PM NRR/LPL3-1/LA NRR/LPL3-1/BC NAME PTam THarris LJames DATE 7/10/08 7/9/08 7/11/08
design in relation to the welds and the coverage obtained within the examination volume requirements of Code Case N-613-1, Figure 2.
The licensee stated that compliance with the examination coverage requirements of the ASME Code,Section XI, would require modification, redesign, or replacement of components where geometry is inherent to the component design.
3.5 The Licensees Proposed Alternative and Basis In accordance with 10 CFR 50.55a(g)(5)(iii), the licensee requested relief for the components listed above on the basis that the required examination coverage of "essentially 100 percent" is impractical due to physical obstructions and the limitations imposed by design, geometry and materials of construction.
The licensee performed qualified examinations that achieved the maximum, practical amount of coverage obtainable within the limitations imposed by the design of the components.
Additionally, as Class 1 examination Category B-P components, the licensee performs a VT-2 examination on the subject components of the reactor coolant pressure boundary during system pressure tests each refueling outage. This was completed during the 2007 refueling outage and no evidence of leakage was identified for these components.
Therefore, pursuant to 10 CFR 50.55a(g)(5)(iii), the licensee requested relief from the requirements of ASME Section XI Table IWB-2500-1, Category B-D, Item B3.90, and proposed to use these completed exams as acceptable alternatives that provide reasonable assurance of continued structural integrity.
3.6 Duration of the Proposed Request NMC requested the granting of this relief for the fourth 10-year ISI interval of the MNGP ISI program that is scheduled to end on May 31, 2012.
3.7 NRC Staff Evaluation The licensee achieved the following percentages of examination volume coverage for the subject five welds during the 2007 refueling outage inspection.
Component Nozzle number Weld number Exam coverage %
RPV Recirc inlet N-2B N-2B NV 78 RPV Recirc inlet N-2G N-2G NV 78 RPV Feedwater inlet N-4A N-4A NV 79 RPV Top Head Spare N-6A N-6A NV 86 RPV CRD Return Nozzle N-9 N-9 NV 85 The licensees nondestructive examination procedures incorporate inspection techniques qualified under Appendix Vlll of the ASME Code,Section XI, by the Performance Demonstration Initiative (PDI) for examination of the subject nozzle-to-vessel welds, and allow the examination volume to meet the provisions of alternative requirements (i.e., Code Case N-613-1). In the March 21, 2008, letter, the licensee stated that the PDI Program meets the requirements of 10 CFR 50.55a up through the 2001 Edition of Section XI. The ASME Code,Section XI, from the 1998 edition through the 2001 edition has been incorporated by reference in 10 CFR 50.55a.
Corrected by letter of 7/11/2008
Therefore, pursuant to 10 CFR 50.55a(g)(6)(i), relief is granted to MNGP in accordance with ISI Relief Request No. 15 for the fourth 10-year ISI interval. The granting of this relief is authorized by law and will not endanger life or property or the common defense and security, and is otherwise in the public interest giving due consideration to the burden upon the licensee that could result if the requirements were imposed on the facility.
All other requirements of the ASME Code, for which relief has not been specifically requested and approved remain applicable, including third party review by the Authorized Nuclear Inservice inspector.
Principal Reviewer: John Tsao Dated: May 19, 2008 Corrected by letter of 7/11/2008
Monticello Nuclear Generating Plant cc.
Peter M. Glass Assistant General Counsel Xcel Energy Services, Inc.
414 Nicollet Mall (MP4)
Minneapolis, MN 55401 U.S. Nuclear Regulatory Commission Resident Inspector's Office 2807 W. County Road 75 Monticello, MN 55362 Manager, Nuclear Safety Assessment Monticello Nuclear Generating Plant Nuclear Management Company, LLC 2807 West County Road 75 Monticello, MN 55362-9637 Commissioner Minnesota Pollution Control Agency 520 Lafayette Road St. Paul, MN 55155-4194 Commissioner Minnesota Department of Health 717 Delaware Street, S. E.
Minneapolis, MN 55440 Douglas M. Gruber, Auditor/Treasurer Wright County Government Center 10 NW Second Street Buffalo, MN 55313 Commissioner Minnesota Department of Commerce 85 7th Place East, Suite 500 St. Paul, MN 55101-2198 Manager - Environmental Protection Division Minnesota Attorney General=s Office 445 Minnesota St., Suite 900 St. Paul, MN 55101-2127 Nuclear Asset Manager Xcel Energy, Inc.
414 Nicollet Mall (MP4)
Minneapolis, MN 55401 Dennis L. Koehl Chief Nuclear Officer Nuclear Management Company, LLC 414 Nicollet Mall (MP4)
Minneapolis, MN 55401 December 2007