ML21014A427

Supplement to ASME Section XI Inservice Inspection Program Relief Requests for Limited Coverage Examinations Performed in the Third Period of the Fourth-Year Inspection Interval

ML21014A427
Person / Time
Site:	Millstone
Issue date:	01/14/2021
From:	Mark D. Sartain Dominion Energy Nuclear Connecticut
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
20-073A
Download: ML21014A427 (2)

Text

Dominion Energy Nuclear Connecticut, Inc.

5000 Dominion Boulevard, Glen Allen, VA 23060 Dominion DominionEnergy.com Energy January 14, 2021 U.S. Nuclear Regulatory Commission Serial No. 20-073A Attention: Document Control Desk NRA/SS RO Washington, DC 20555 Docket No. 50-336 License No. DPR-65 DOMINION ENERGY NUCLEAR CONNECTICUT, INC.

MILLSTONE POWER STATION UNIT 2 SUPPLEMENT TO ASME SECTION XI INSERVICE INSPECTION PROGRAM RELIEF REQUESTS FOR LIMITED COVERAGE EXAMINATIONS PERFORMED IN THE THIRD PERIOD OF THE FOURTH 10-YEAR INSPECTION INTERVAL By letter dated September 23, 2020 (ADAMS Accession No. ML20268A225), Dominion Energy Nuclear Connecticut, Inc. (DENG) requested that the Nuclear Regulatory Commission (NRC) provide relief from the American Society of Mechanical Engineers (ASME)Section XI requirements (pursuant to 10 CFR 50.55a(g)(5)(iii)) for components at Millstone Power Station Unit 2 (MPS2). Specifically, these requests applied to components that received less than the required examination coverage during the third inspection period of the fourth 10-year inservice inspection interval. Two relief requests were attached to the letter, with Attachment 1 (RR-04-31) being applicable to Examination Category B-B welds, and Attachment 2 (RR-04-32) being applicable to Examination Category R-A piping. (RR-04-31) contained only one weld (i.e., SG-1-BHC-1-A) within its scope.

The required cross-sectional examination area (139 in. 2) provided for weld SG-1-BHC-1A was reviewed by DENG in response to a question from the NRC and found to be incorrect. The corrected required cross-sectional examination area for this weld was determined to be 73.26 in. 2 , resulting in an examination coverage of 91.53%. Since more than 90% of the required volume was actually examined, the examination of weld SG BHC-1A can now be credited as providing essentially 100% coverage (in accordance with ASME Code Case N-460, which has been approved for use in Regulatory Guide 1.147, Revision 19). Due to this correction, relief from ASME Code examination coverage requirements* is no longer needed for weld SG-1-BHC-1A. Since no other welds are contained within the scope of RR-04-31, DENG requests withdrawal of relief request RR-04-31 from the September 23, 2020 letter.

Serial No. 20-073A Docket No. 50-336 Page 2 of 2 If you have any questions or require additional information, please contact Shayan Sinha at (804) 273-4687.

Sincerely, Mark D. Sartain Vice President - Nuclear Engineering & Fleet Support Attachments: None Commitments made in this letter: None cc: U.S. Nuclear Regulatory Commission Region I 2100 Renaissance Blvd, Suite 100 King of Prussia, PA 19406-2713 R. V. Guzman Senior Project Manager U.S. Nuclear Regulatory Commission One White Flint North, Mail Stop 08-C 2 11555 Rockville Pike Rockville, MD 20852-2738 NRC Senior Resident Inspector Millstone Power Station