ML25077A198
| ML25077A198 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 03/17/2025 |
| From: | James Holloway Dominion Energy, Dominion Energy Nuclear Connecticut |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| References | |
| 24-103C | |
| Download: ML25077A198 (1) | |
Text
Dominion Energy Nuclear Connecticut. Inc.
5000 Dominion Boulevard. Glen Allen. VA 23060 Dominion Energy.com March 17, 2025 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555 DOMINION ENERGY NUCLEAR CONNECTICUT, INC.
MILLSTONE POWER STATION UNIT 3 Dominion Energy~
Serial No.:
NRA/NDM Docket No.:
License No.:
24-103C RO 50-423 NPF-49 SUPPLEMENT TO ALTERNATIVE REQUEST IR-4-13, PROPOSED ALTERNATIVE REQUEST TO SUPPORT STEAM GENERA TOR CHANNEL HEAD DRAIN MODIFICATION By letter date April 1, 2024 (ADAMS Accession No. ML24093A102), Dominion Energy Nuclear Connecticut, Inc. (DENG) requested Nuclear Regulatory Commission (NRG) approval of a proposed alternative (Alternative Request IR-4-13) to certain requirements associated with the steam generator (SG) channel head drain weld repairs for Millstone Power Station Unit 3 (MPS3). DENG will be performing modifications on the channel head drain connection for each SG in accordance with the American Society of Mechanical Engineers (ASME) Code Case N-839. Alternative Request IR-4-13 requested relief from the Code Case requirement to use a 48-hour hold time and volumetric inspection method for final examination, due to hardship without a compensating increase in quality or safety in accordance with 10 CFR 50.55(z)(2).
The Alternative Request IR-4-13 submittal stated that the SG channel head drain modifications are scheduled for the spring 2025 MPS3 refueling outage. DENC is updating this information to clarify that the SG channel head drain modification may take place during either the spring 2025 MPS3 refueling outage or the fall 2026 MPS3 refueling outage, pending the results of visual inspections. As explained in Alternative Request IR-4-13, this activity was planned in consideration of operating experience detailed in Westinghouse Technical Bulletin TB-04-19 and was being performed as a proactive modification. Delaying the activity to the fall 2026 MPS3 refueling outage would not change the applicable lnservice Inspection (ISi) interval, as the modification would still be completed during the current fourth MPS3 10-year ISi Interval, which ends on February 22, 2029.
Serial No.: 24-103C Docket No.: 50-423 Page 2 of 2 If you have any questions or require additional information, please contact Nick Maynard at (804) 273-3910.
Sincerely,
°'r= ){il2~y James E. Holloway
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Vice President - Nuclear Engineering & Fleet Support Attachments: None.
Commitments made in this letter: None.
cc:
U.S. Nuclear Regulatory Commission Region I 475 Allendale Road, Suite 105 King of Prussia, PA 19406-1415 Richard. V. Guzman Senior Project Manager U.S. Nuclear Regulatory Commission One White Flint North, Mail Stop 9 E3 11555 Rockville Pike Rockville, MD 20852-2738 NRC Senior Resident Inspector Millstone Power Station