ML20209A536

Response to Request for Additional Information Regarding Relief Request IR-3-33 for Limited Coverage Examinations Performed in the Second Period of the Third 10-Year Inspection Interval

ML20209A536
Person / Time
Site:	Millstone
Issue date:	07/27/2020
From:	Mark D. Sartain Dominion Energy Nuclear Connecticut
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
20-257
Download: ML20209A536 (4)

Text

Dominion Energy Nuclear Conn ecticut, Inc.

5000 Domini on Boulevard, Glen All en, VA 23 060 Dom inionE nergy.com P

j I Dominion Energy'*,

July 27, 2020 U. S. Nuclear Regulatory Commission Serial No ,20-257 Attention: Document Control Desk NRA/SS RO Washington , DC 20555 Docket No . 50-423 License No. NPF-49 DOMINION ENERGY NUCLEAR CONNECTICUT, INC.

MILLSTONE POWER STATION UNIT 3 RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING RELIEF REQUEST IR-3-33 FOR LIMITED COVERAGE EXAMINATIONS PERFORMED IN THE SECOND PERIOD OF THE THIRD 10-YEAR INSPECTION INTERVAL By letter dated February 17, 2020 (ADAMS Accession No, ML20049A088), Dominion Energy Nuclear Connecticut, Inc. (DENC) submitted relief requests for Millstone Power Station Unit 3 (MPS3) for the second period of the third 10-year inservice inspection interval. MPS3 began the third 10-year interval on April 23 , 2009 . Pursuant to 10 CFR 50.55a(g)(5)(iii) , DENC requested relief on the basis that the required examination coverage was impractical for the identified components due to physical obstructions and limitations imposed by design, geometry and materials of construction of the subject components .

In an email dated June 29, 2020 , the NRC issued a draft request for additional information (RAI) related to relief request IR-3-33, which was included in the February 17, 2020 submittal. DENC indicated that a clarification call was not necessary to respond to the information request and agreed to respond to the RAI by August 3, 2020. In an email dated July 2, 2020 , the NRC transmitted the final version of the RAI.

The attachment provides DENC 's response to the RAI.

Should you have any questions regarding this submittal , please contact Shayan Sinha at (804) 273-4687.

Mark D. Sartain Vice President - Nuclear Engineering & Fleet Support

Serial No: 20-257 Docket No. 50-423 Page 2 of 2

Attachment:

Response to Request for Additional Information Related to Millstone Power Station Unit 3 Relief Request IR-3-33 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 - Millstone Power Station U.S. Nuclear Regulatory Commission One White Flint North 11555 Rockville Pike Mail Stop 08 C2 Rockville, MD 20852-2738 NRC Senior Resident Inspector Millstone Power Station

Serial No.20-257 Docket No. 50-423 ATTACHMENT RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION RELATED TO MILLSTONE POWER STATION UNIT 3 RELIEF REQUEST IR-3-33 DOMINION ENERGY NUCLEAR CONNECTICUT, INC.

MILLSTONE POWER STATION UNIT 3

Serial No.20-257 Docket No. 50-423 Attachment, Page 1 of 1 By letter dated February 17, 2020 (ADAMS Accession No. ML20049A088), Dominion Energy Nuclear Connecticut, Inc. (DENC) submitted relief requests for Millstone Power Station Unit 3 {MPS3) for the second period of the third 10-year inservice inspection interval. MPS3 began the third 10-year interval on April 23, 2009. Pursuant to 10 CFR 50.55a(g)(5)(iii), DENC requested relief on the basis that the required examination coverage was impractical for the identified components due to physical obstructions and limitations imposed by design, geometry and materials of construction of the subject components.

In an email dated June 29, 2020, the NRC issued a draft request for additional information (RAI) related to relief request IR-3-33, which was included in the February 17, 2020 submittal. DENC indicated that a clarification call was not necessary to respond to the information request and agreed to respond to the RAI by August 3, 2020. In an email dated July 2, 2020, the NRC transmitted the final version of the RAI. This attachment provides DENC's response to the RAI.

RAI 1

ASME Code,Section XI, Article 1-2210 states that ultrasonic examination of vessels not greater than 2 inches in thickness shall be conducted in accordance with Appendix Ill, as supplemented by Table 1-2000-1. Relief Request IR-3-33 states that Weld 03-074-004, an Examination Category C-A Pressure Retaining Weld in Pressure Vessels, was examined using equipment and procedures written in accordance with ASME Section XI, Appendix I and Section V, Article 4. The staff notes that the thickness of Weld 03-074-004 is less than 2 inches; therefore, it appears that this weld should be examined in accordance with Appendix Ill of the ASME Code,Section XI as well.

Please discuss whether Weld 03-074-004 was examined in accordance with ASME Code,Section XI, Appendix Ill as supplemented by Table 1-2000-1, as required by Section XI, Article 1-2210. If not, please provide justification.

DENC Response to RAI 1 The ultrasonic examination record for weld 03-074-004 has been reviewed to determine the examination procedure used to perform this examination. This weld has been verified as an Examination Category C-A, Pressure Retaining Weld in Pressure Vessels, less than 2.0 inches in thickness. The examination record documents that this weld was examined in accordance with an ultrasonic procedure that complies with ASME Section XI, Appendix 111, as supplemented by Table 1-2000-1.