ML070650521
| ML070650521 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 03/06/2007 |
| From: | Gerald Bichof Virginia Electric & Power Co (VEPCO) |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| 07-0158 | |
| Download: ML070650521 (3) | |
Text
VIRGINIA ELECTRIC AND POWER COMPANY
- RICHMOND, VIRGINIA 2326 1 March 6, 2007 United States Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C. 20555 Serial No.
07-0158 NLOSIGDM RO Docket No. 50-339 License No. NPF-7 VIRGINIA ELECTRIC AND POWER COMPANY NORTH ANNA POWER STATION UNIT 2 REVISED ASME SECTION XI INSERVICE INSPECTION PROGRAM RELIEF REQUEST PARTIAL EXAMINATION OF REACTOR PRESSURE VESSEL HEAD-TO-FLANGE WELDS - CMP-020-R1 REQUEST FOR ADDITIONAL INFORMATION In a letter dated January 28, 2003 (Serial No.03-050), Virginia Electric and Power Company (Dominion) submitted Relief Request CMP-020 for North Anna Unit 2. Relief Request CMP-020 requested relief from the ASME Section XI requirement to perform a volumetric examination of essentially 100 percent of the weld length of the reactor pressure vessel (RPV) closure head-to-flange weld. The relief was required due to the configuration of the reactor vessel head that precluded 100% volumetric coverage. Two alternate provisions for the 100% volumetric examination requirement were provided in the relief request as follows:
- 1. One third of the reactor pressure vessel head-to-flange weld will be examined each period to the extent permitted by the configuration of the reactor pressure vessel closure head as radiologically practical, and
- 2. The pre-service examinations already completed at the reduced coverage be counted as meeting the Code requirements.
The NRC approved relief request CMP-020, including the two alternate provisions, in their safety evaluation report dated November 13, 2003.
In a letter dated January 9, 2007 (Serial No. 06-1083), Dominion submitted Relief Request CMP-020-1 to revise the first alternative provision noted above. Specifically, the provision was revised to permit the examination of the entire RPV head-to-flange weld, with the noted constraints, in the third period of the third 10-year inservice inspection interval, rather than examination of one third of the weld during each period as stated in approved Relief Request CMP-020. The revised relief request was submitted due to the extensive amount of RPV head inspection activities already planned for the spring 2007 Unit 2 refueling outage, which is the last refueling outage of the second period of the third 10-year interval.
Serial No. 07-0158 Docket No. 50-339 Page 2 In a letter dated February 27, 2007, the NRC requested additional information to facilitate their review of Relief Request CMP-020-1. The NRC stated that it appeared "...that the licensee's intent is to use the pre-service examinations as an alternative for the scheduled second period, third 10-year IS1 interval ASME Code,Section XI volumetric examinations." This is not Dominion's intent. As indicated by the revision bar in the right hand margin of Section V, Alternate Provisions, in Relief Request CMP-020-1, the only change to the relief is the scheduling of the RPV head-to-flange weld examination as allowed by the ASME Code. Specifically, there is only one ASME Table IWB-2500-1, examination category B-A, item number 81.40 weld for North Anna Unit 2 that has not been deferred to the third period. ASME Section IWB-2412 states that when there is only one weld that requires examination, the weld may be examined in any one period.
Therefore, the revised relief request states that the entire RPV head-to-flange weld examination will be performed, consistent with the constraints specified in the relief request, in the third period of the third 10-year inservice inspection interval, as opposed to examining one third of the weld each period as previously approved in Relief Request CMP-020. The second alternate provision in Section V of the relief request associated with pre-service examinations is not affected by the requested revision.
If you have any questions or require additional information, please contact Mr. Tom Shaub at (804) 273-2763.
Very truly yours, Gerald T. Bischof u Vice President - ~uclear Engineering Commitments made in this letter: None
Serial No. 07-0158 Docket No. 50-339 Page 3 cc:
U.S. Nuclear Regulatory Commission Region II Sam Nunn Atlanta Federal Center 61 Forsyth Street, SW Suite 23T85 Atlanta, Georgia 30303 Mr. J. E. Reasor, Jr.
Old Dominion Electric Cooperative l nnsbrook Corporate Center 4201 Dominion Blvd.
Suite 300 Glen Allen, Virginia 23060 Mr. J. T. Reece NRC Senior Resident lnspector North Anna Power Station Mr. S. P. Lingam NRC Project Manager U. S. Nuclear Regulatory Commission One White Flint North 1 1 555 Rockville Pike Mail Stop 8G9A Rockville, Maryland 20852 Mr. R. E. Martin NRC Project Manager U. S. Nuclear Regulatory Commission One White Flint North 1 1555 Rockville Pike Mail Stop 8-HI2 Rockville, Maryland 20852 Mr. M. M. Grace Authorized Nuclear Insurance lnspector North Anna Power Station