ML24043A144
| ML24043A144 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 02/09/2024 |
| From: | James Holloway Virginia Electric & Power Co (VEPCO) |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| References | |
| 24-054 | |
| Download: ML24043A144 (1) | |
Text
VIRGINIA ELECTRIC AND POWER COMPANY RICHMOND, VlRGil'HA 23261 February 9, 2024 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555-0001 Serial No.:
NRA/GDM:
Docket Nos.:
10 CFR 50.90 24-054 License Nos.:
R3 50-338/339 NPF-4/7 VIRGINIA ELECTRIC AND POWER COMPANY NORTH ANNA POWER STATION UNITS 1 AND 2 LICENSE AMENDMENT REQUEST TO REVISE THE EMERGENCY PLAN RELOCATION OF THE TECHNICAL SUPPORT CENTER SUPPLEMENTAL INFORMATION By letters dated January 13, 2023 [Agencywide Document Access and Management System (ADAMS) Accession No. ML23013A195] as supplemented by letters dated June 27, 2023 [ADAMS Accession No. ML23192A215], and December 11, 2023 [ADAMS Accession No. ML23346A097], Virginia Electric and Power Company (Dominion Energy Virginia) submitted a license amendment request (LAR) to revise the North Anna Power Station (NAPS) Units 1 and 2 Emergency Plan. The proposed change would relocate the Technical Support Center (TSC) from its current location adjacent to the Main Control Room (MCR) to the building located outside the Protected Area (PA) previously used as the site Local Emergency Operations Facility (LEOF).
In Section 3.1.6 of the LAR, Habitability, a discussion of the TSC ventilation system was provided that stated the following:
During emergency operation, the exhaust fans will be de-energized and isolated via dampers enabling the building's static pressure controller to modulate the filter fan speed to maintain the conditioned space at 0.125 inches water gauge (WG) relative to the outside air pressure to prevent infiltration of outside air.
After submittal of the LAR, it was determined that the filter fan is not modulated. Fan modulation is not required since the design of the HVAC system includes multiple automatic Fan Powered Variable Air Volume (4) and Variable Air Volume (7) units that modulate as necessary to control the temperature in the envelope. Furthermore, during TSC ventilation testing, it was observed that changes of the variable air volume units affect the positive pressure values obtained in the TSC such that the 0.125 inches of water pressure value could be challenged.
Therefore, the TSC positive pressure minimum limit is being reduced to compensate for seasonal temperature changes. As a result, the sentence above is being revised to state the following:
Serial No.: 24-054 Docket Nos.: 50-338/339 Page 2 of 3 During emergency operation, the exhaust fans will be de-energized and isolated via dampers enabling the filter fan to maintain the occupied space at ~O. 10 inches of water relative to the outside air pressure to prevent infiltration of outside air. The penthouse, which is not an occupied space, will be maintained at positive pressure of ~O. 05 inches of water to prevent outside air infiltration.
The TSC dose analysis does not model pressure. It assumes positive pressure and vestibule design features prevent unfiltered inleakage. Therefore, the dose analysis is not impacted by the reduction in the minimum acceptable pressure for the penthouse and occupied TSC space since positive pressure is being maintained.
Should you have any questions or require additional information, please contact Mr. Gary D. Miller at (804) 273-2771.
Respectfully, James E. Holloway Vice President - Nuclear Engineering and Fleet Support Commitments contained in this letter: None.
COMMONWEAL TH OF VIRGINIA )
)
COUNTY OF HENRICO
)
The foregoing document was acknowledged before me, in and for the County and Commonwealth aforesaid, today by James E. Holloway, who is Vice President - Nuclear Engineering and Fleet Support, of Virginia Electric and Power Company. He has affirmed before me that he is duly authorized to execute and file the foregoing document in behalf of that company, and that the statements in the document are true to the best of his knowledge and belief.
-Ht Acknowledged before me this C/
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, 2024.
My Commission Expires: ---- z;...,/=3--11 {=2-4if ____ _
CRAIG D SLY Notary Public Commonwealth of Virginia Reg.# 751 8653
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My Commission Expires December 31, 2U_
Notary Public
cc:
U.S. Nuclear Regulatory Commission - Region II Attn: Regional Administrator 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 09 E-3 11555 Rockville Pike Rockville, Maryland 20852-2738 Mr. L. John Klos NRC Project Manager - Surry Power Station U.S. Nuclear Regulatory Commission One White Flint North Mail Stop 09 E-3 11555 Rockville Pike Rockville, Maryland 20852-2738 NRC Senior Resident Inspector North Anna Power Station State Health Commissioner Virginia Department of Health James Madison Building - 7th floor 109 Governor Street, Suite 730 Richmond, Virginia 23219 Old Dominion Electric Cooperative R-North-Anna-Correspondence@odec.com Serial No.: 24-054 Docket Nos.: 50-338/339 Page 3 of 3