ML24234A074
| ML24234A074 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 08/15/2024 |
| From: | James Holloway Virginia Electric & Power Co (VEPCO) |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| References | |
| 24-247 | |
| Download: ML24234A074 (1) | |
Text
VIRGINIA ELECTRIC AND POWER COMPANY RICHMOND, VIRGINIA 23261 August 15, 2024 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555-0001 VIRGINIA ELECTRIC AND POWER COMPANY NORTH ANNA POWER STATION UNITS 1 AND 2 Serial No.:
24-247 NRA/JH:
R2 Docket Nos.:
50-338/339 License Nos.: NPF-4/7 NOTIFICATION OF DEVIATION FROM PRESSURIZED WATER REACTOR OWNERS GROUP (PWROG) LETTER OG-23-63, "NEI 03-08 NEEDED GUIDANCE: PWR THERMAL SHIELD FLEXURE INSPECTION REQUIREMENTS" In accordance with Appendix B, Section 8.1.c, of reference 1, Virginia Electric and Power Company (Dominion Energy Virginia) hereby provides notification that Dominion Energy Virginia has processed a deviation from "Needed" guidance contained in reference 2 for North Anna Power Station (NAPS) Units 1 and 2. The deviation is from guidance which requires that initial neutron noise monitoring be implemented prior to July 1, 2024, or within two operating cycles of the most recent thermal shield flexure inspection. Dominion Energy Virginia is in the process of purchasing a neutron noise monitoring system to allow utility personnel to obtain the required data. The deviation will be in effect approximately three months and is currently projected to be corrected by October 1, 2024.
NAPS Unit 1 and Unit 2 thermal shield flexures were last inspected during the spring 2018 and fall 2020 refueling outages, respectively, and no indications were identified.
In reference 3, PWROG evaluation concluded that NAPS Units 1 and 2 have low susceptibility to flexure failure. If flexure degradation has occurred since the last visual inspection, industry experience is that negligible degradation would occur during the three months of delay to initiate neutron noise monitoring and identify degradation. Therefore, delay of the initial neutron noise monitoring date by three months is not anticipated to change the ability to meet the level of conservatism in the Reference 2 "Needed" guidance.
Reference 1 allows deviation from "Needed" guidance with the appropriate justification and documentation. The technical justification for this deviation was documented in the Dominion Energy Virginia Corrective Action Program, approved in accordance with Dominion Energy Virginia procedures, and provided to the PWROG.
In accordance with reference 1, this letter is being transmitted for information only and no action is requested from the Nuclear Regulatory Commission staff.
Serial No.: 24-247 Docket Nos.: 50-338/339 Page 2 of 2 If you have any questions or require additional information, please contact Julie Hough at 804-273-3586.
Respectfully,
~
James E. Holloway Vice President - Nuclear Engineering and Fleet Support
References:
- 1. Nuclear Energy Institute (NEI) 03-08, "Guideline for the Management of Materials Issues," Revision 4
PWR Thermal Shield Flexure Inspection Requirements," dated May 8, 2023
- 3. PWROG-21015-P, Revision 1, "Thermal Shield Flexure Susceptibility Study" Commitments made by this letter: None cc:
Regional Administrator, Region II Marquis One Tower 245 Peachtree Center Avenue, NE., Suite 1200 Atlanta, Georgia 30303-1257 Mr. G. Edward Miller NRC Senior Project Manager - North Anna Power Station U. S. Nuclear Regulatory Commission One White Flint North Mail Stop 9 E-3 11555 Rockville Pike Rockville, Maryland 20852-2738 Chief, Vessels and Internals Branch (NRR/DRNL/NVIB)
Chief, Piping and Head Penetrations Branch (NRR/DNRL/NPHP)
NRC Senior Resident Inspector North Anna Power Station