ML072070356
| ML072070356 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 07/25/2007 |
| From: | Grecheck E Dominion, Virginia Electric & Power Co (VEPCO) |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| 07-0421A | |
| Download: ML072070356 (5) | |
Text
VIRGINIA ELECTRIC AND POWER COMPANY
- RICHMOND, VIRGINIA 2326 1 July 25, 2007 U.S. Nuclear Regulatory Commission Attention: Document Control Desk One White Flint North 1 1 555 Rockville Pike Rockville, MD 20852-2738 Serial No.
07-0421 A NLOS IETS Docket Nos. : 50-3381339 License Nos.: NPF-417 VIRGINIA ELECTRIC AND POWER COMPANY (DOMINION)
NORTH ANNA POWER STATION UNlT 1 - CMP-022R1 NORTH ANNA POWER STATION UNlT 2 - CMP-023R1 RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION WELD OVERLAYS AS AN ALTERNATIVE REPAIR TECHNIQUE In letters dated January 3, 2007 and March 17, 2007 (Serial Nos. 06-1007 and 1007A),
Dominion requested approval to use the proposed alternative of applying dissimilar metal weld overlays for repairlreplacement activities.
That request contained alternative requirements for the inservice inspection (ISI) program for scheduled full structural preemptive weld overlays (PWOLs) that are planned to mitigate the potential for primary water stress corrosion cracking (PWSCC) susceptibility at North Anna Units 1 and 2. In a June 29, 2007 e-mail, the NRC requested additional clarification on: 1) the ASME Section XI, Appendix Vlll examination requirements and 2) the stress analysis discussed in our March 17, 2007 alternative.
The attachment to this letter contains the requested information.
PWOLs were completed on the North Anna Unit 2 pressurizer welds in the spring 2007 refueling outage and are scheduled to be completed on North Anna Unit 1 pressurizer welds in the fall 2007 refueling outage. No pre-weld overlay ultrasonic examinations are planned.
If you have any questions regarding this submittal, please contact Mr. Thomas Shaub at (804) 273-2763.
Very truly yours, u
\\
Eugene S. Grecheck Vice President - Nuclear Support Services Commitments made in this letter: None Attachment
- 1.
Response to NRC June 29,2007 Request for Additional Information.
Serial No. 07-0421 A Docket Nos. 50-3381339 RAI - CMP-022R11023Rl Page 2of 2 cc:
U.S. Nuclear Regulatory Commission Region II Sam Nunn Atlanta Federal Center 61 Forsyth Street, SW Suite 237-85 Atlanta, Georgia 30303 Mr. J. E. Reasor, Jr.
Old Dominion Electric Cooperative lnnsbrook Corporate Center 4201 Dominion Blvd.
Suite 300 Glen Allen, Virginia 23060 Mr. J. T. Reece NRC Senior Resident lnspector North Anna Power Station Mr. R. A. Jervey NRC Project Manager -North Anna U. S. Nuclear Regulatory Commission One White Flint North 1 1 555 Rockville Pike Mail Stop 8-G9A Rockville, Maryland 20852 Mr. S. P. Lingam NRC Project Manager - Surry U. S. Nuclear Regulatory Commission One White Flint North 1 1 555 Rockville Pike Mail Stop 8-G9A Rockville, Maryland 20852 Mr. M. M. Grace Authorized Nuclear Insurance lnspector North Anna Power Station
Serial No. 07-0421A Docket Nos. 50-3381339 ATTACHMENT RESPONSE TO JUNE 29,2007 REQUEST FOR ADDITIONAL INFORMATION WELD OVERLAYS AS AN ALTERNATIVE REPAIR TECHNIQUE CMP-022 R1 AND CMP-023 R1 NORTH ANNA POWER STATION UNITS 1 AND 2 VIRGINIA ELECTRIC AND POWER COMPANY (DOMINION)
Serial No. 07-0421A Docket Nos. 50-3381339 RAI - CMP-022R11023Rl Page 1 of 2 RESPONSE TO JUNE 29,2007 REQUEST FOR ADDITIONAL INFORMATION WELD OVERLAYS AS AN ALTERNATIVE REPAIR TECHNIQUE CMP-022 R1 AND CMP-023 R1 NRC Question 1 On page 3 of Attachment 1 to the licensee's January 3, 2007 submittal, the licensee stated that the ultrasonic examination of the completed PWOLs will be accomplished in accordance with the ASME Code,Section XI, 1989 Edition for North Anna Unit 1 and the 1995 Edition including addenda through 1996 for North Anna Unit 2, Appendix VIII, Supplement 11, with the alternative used for complying with the Performance Demonstration Initiative (PDI) program. The staff questions why the licensee proposed to use the 1989 edition to perform UT of the weld overlays at North Anna Unit 1 because 10 CFR 50.55a(g)(6)(ii)(C) requires licensees to use the 1995 Edition with the 1996 addenda of the ASME Code Section XI, Appendix VIII, Supplement 11, to perform UT.
Dominion Res~onse Dominion concludes that the wording could be misleading.
To clarify Dominion's position the following summary is provided:
Dominion performed the ultrasonic examinations on the completed PWOLs for North Anna Unit 2 in accordance with the ASME Code Section XI, 1998 Edition including the 2000 Addenda, Appendix VIII, Supplement 11 with the alternatives used for complying with the PDI Program.
Based on a November 24, 2003 SER for North Anna Units 1 and 2, which permitted the use of the 1998 Edition through 2000 Addenda of ASME Code,Section XI, Subsection IWA-2300, and Appendices VI, VII, and VIII, Dominion will perform ultrasonic examination of the completed PWOLs for North Anna Unit 1 in accordance with the ASME Code Section XI, 1998 Edition including the 2000 Addenda, Appendix VIII, Supplement 11 with the alternatives used for complying with the PDI Program.
NRC Question 2 On page 5 of Attachment 2 to the March 13, 2007 submittal, the licensee stated that
"...This portion of the analysis will be addressed with an engineering evaluation of insurge/outsurge transients... for seven heatups and cooldowns with thirty insurge/outsurge cycles..." These cycles seem to be low for the life of either Unit 1 or Unit 2.
(a) Clarify whether the seven heatups and cooldowns with thirty insurge/outsurge cycles are applied for one operating cycle or for the life of the units in
Serial No. 07-0421 A Docket Nos. 50-3381339 RAI - CMP-022R11023R1 Page 2 of 2 the, ASME Section Ill calculations; (b) Clarify whether the above statement means that seven heatups, seven cooldowns; and thirty insurge/outsurge cycles were used in the ASME Section Ill calculations, and, (c) Describe exactly what ASME Section Ill calculations were performed using the above transient cycles and how were the cycles applied in the analysis.
Dominion R ~ S D O ~ S ~
(a)
Clarify whether the seven heatups and cooldowns with thirty insurge/outsurge cycles are applied for one operating cycle or for the life of the units in the ASME Section Ill calculations, The North Anna specific ASME Section Ill analysis, which addresses the life of the plant, will be completed by December 31, 2007. In the interim, an engineering evaluation was performed for which the number of heatups and cooldowns and insurge/outsurge cycles were derived and qualified by data from the DC Cook ASME Section Ill analysis which is representative of the North Anna conditions and configuration. The seven heatups and cooldowns with thirty insurge/outsurge cycles represent a very conservative limit placed on interim operation and are associated with the interim analysis and interim measures and not meant to correlate with an operating cycle.
(b)
Clarify whether the above statement means that seven heatups, seven cooldowns, and thirty insurge/outsurge cycles were used in the ASME Section Ill calculations, The seven heatups, seven cooldowns, and thirty insurge/outsurge cycles were not used in the ASME Section Ill analysis. The North Anna ASME Section Ill analysis will be completed by December 31, 2007 and will be an elastic-plastic analysis based on the defined number for life of plant transients.
(c)
Describe exactly what ASME Section Ill calculations were performed using the above transient cycles and how were the cycles applied in the analysis.
As stated previously, the North Anna ASME Section Ill analysis has not been completed. The ASME Section Ill analysis will be completed by December 31, 2007 and will account for all transient cycles.