ML13198A091

Response to Request for Additional Information ASME Section Xl Inservice Inspection Program Relief Request NI-14-LMT-001 - Fourth Interval Period 1 Limited Examinations

ML13198A091
Person / Time
Site:	North Anna
Issue date:	07/12/2013
From:	Grecheck E Virginia Electric & Power Co (VEPCO)
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
13-393
Download: ML13198A091 (4)

Text

10 CFR 50.55a VIRGINIA ELECTRIC AND POWER COMPANY RICHMOND, VIRGINIA 23261 July 12, 2013 United States Nuclear Regulatory Commission Serial No.13-393 Attention: Document Control Desk NAPS/JHL RO Washington, D.C. 20555 Docket No. 50-338 License No. NPF-4 VIRGINIA ELECTRIC AND POWER COMPANY (DOMINION)

NORTH ANNA POWER STATION UNIT 1 RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION ASME SECTION Xl INSERVICE INSPECTION PROGRAM RELIEF REQUEST NI-14-LMT-001 - FOURTH INTERVAL PERIOD 1 LIMITED EXAMINATIONS By letter dated November 1, 2012 (Serial No.12-660), Virginia Electric and Power Company (Dominion) submitted a relief request for limited examination coverage (i.e.,

less than 90% weld coverage achieved, due to physical interferences that prohibited attaining full weld coverage) obtained during the inservice inspection (ISI) examinations at North Anna Power Station Unit 1 during the fourth ten-year ISI interval. These examinations were performed to meet the requirements of the 2004 Edition of ASME Section Xl with No Addenda and the Risk-Informed/Safety-Based Inservice Inspection (RIS B) Program Plan based on Code Case N-716. In an E-mail from Dr. V. Sreenivas, dated March 4, 2013, the NRC requested additional information to complete the review of the limited examination relief request. This information was provided in a letter dated April 5, 2013 (Serial No.13-141). In a subsequent E-mail from Dr. V. Sreenivas dated July 2, 2013, the NRC requested further clarification of the information provided in the original relief. This information is provided in the attachment to this letter.

If you have any questions or require additional information regarding the information provided in the attachment, please contact Mr. Thomas Shaub at (804) 273-2763.

Very truly yours, E. S. Grecheck Vice President - Nuclear Engineering and Development

Attachment:

Response to Request for Additional Information - ASME Section Xl Inspection Program Relief Request Nl-14-LMT-001 Fourth Interval Period Limited Examinations Commitments made in this letter: None

Serial No.13-393 Docket No. 50-338 Response to Request for Additional Information Fourth Interval Period 1 ISI Limited Exam Relief Request Page 2 of 2 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 Innsbrook Corporate Center 4201 Dominion Blvd.

Suite 300 Glen Allen, Virginia 23060 NRC Senior Resident Inspector North Anna Power Station Ms. K. R. Cotton Gross NRC Project Manager U. S. Nuclear Regulatory Commission One White Flint North Mail Stop 0-8 G9A 11555 Rockville Pike Rockville, Maryland 20852 Dr. V. Sreenivas NRC Project Manager U. S. Nuclear Regulatory Commission One White Flint North Mail Stop 0-8 G9A 11555 Rockville Pike Rockville, Maryland 20852

Serial No.13-393 Docket No. 50-338 Attachment Response to Request for Additional Information ASME Section XI Inservice Inspection Program Relief Request NI-14-LMT-001 - Fourth Interval Period 1 Limited Examinations North Anna Power Station Unit I Virginia Electric and Power Company (Dominion)

Serial No.13-393 Docket No. 50-338 Page 1 of 1 REQUEST FOR ADDITIONAL INFORMATION (RAI)

VIRGINIA ELECTRIC AND POWER COMPANY NORTH ANNA POWER STATION UNIT 1 BACKGROUND By letter dated November 1, 2012 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML12319A278), Virginia Electric and Power Company (Dominion) submitted Relief Request (RR) Nl-14-LMT-001 for U.S. Nuclear Regulatory Commission (NRC) review and approval. Dominion requested relief from certain requirements of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code), Section Xl, specifically related to examination coverage.

RR Nl-14-LMT-001 is applicable to the fourth 10-year inservice inspection (ISI) interval for the North Anna Power Station (NAPS) Unit 1, which commenced on May 1, 2009 and will end on April 30, 2019. On March 4, 2013, the NRC sent Dominion a request for additional information (RAI) concerning this relief request. The response to the RAI was provided on April 5, 2013. In a subsequent e-mail dated July 2, 2013, the NRC requested further clarification of the information provided in the original relief. The NRC RAI and the Dominion responses are provided below.

NRC INFORMATION REQUEST NRC Question The relief request stated that the volumetric examination identified indications in Welds 8 (12"-SI-67) and SW-12 (32"-SHP-58) that were determined to be root geometry.

Please provide the detail:

• How did the licensee determine that these indications were root geometry?

• Were these root geometries also detected by the previous examinations in these welds?

Dominion Response Beam plots, profiles, along with UT signals were used to characterize the geometrical condition of Weld SW-12 on line 32"-SHP-58. The indications were evaluated using the Indication Classification guidance of the Appendix VIII qualified procedure utilized for the examination. This weld had been examined three previous times with intermittent geometry noted in previous reports.

Beam plots, profiles, along with UT signals were also used to characterize the geometrical condition of Weld 8 on line 12"-SI-67. The indications were evaluated using the Indication Classification guidance of the appendix VIII qualified procedure utilized for the examination. This location was not previously examined.