ML24318C462

Emergency Plan Revision - Relocation of the Technical Support Center (TSC) - License Amendment Nos. 315 and 315 Updated Information Regarding TSC Ventilation Design

ML24318C462
Person / Time
Site:	Surry
Issue date:	11/13/2024
From:	James Holloway Virginia Electric & Power Co (VEPCO)
To:	Office of Nuclear Reactor Regulation, Document Control Desk
References
24-319
Download: ML24318C462 (1)

Text

VIRGINIA ELECTRIC At'\\ID Po,VER COMPANY RrCH.\\IOND, VIRGINIA 23261 November 13, 2024 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555-0001 VIRGINIA ELECTRIC AND POWER COMPANY SURRY POWER STATION UNITS 1 AND 2 Serial No.:

24-319 NRA/GDM:

R1 Docket Nos.: 50-280/281 License Nos.: DPR-32/37 EMERGENCY PLAN REVISION - RELOCATION OF THE TECHNICAL SUPPORT CENTER (TSC) - LICENSE AMENDMENT NOS. 315 AND 315 UPDATED INFORMATION REGARDING TSC VENTILATION DESIGN By letter dated November 18, 2022 [Agencywide Document Access and Management System (ADAMS) Accession No. ML22322A182], as supplemented by letter dated May 31, 2023 (ADAMS Accession No. ML23167B007), Virginia Electric and Power Company (Dominion Energy Virginia) submitted a license amendment request (LAR) to revise the Surry Power Station (SPS) Units 1 and 2 Emergency Plan.

The proposed change relocated 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). By letter dated November 7, 2023 (ADAMS Accession No. ML23242A229), the NRC approved the relocation of the TSC in its safety evaluation for SPS Units 1 and 2 License Amendments 315 and 315, respectively.

In Section 3.1.6, Habitability, of the LAR, a description of the relocated TSC ventilation system was provided as follows:

During an emergency, the TSC ventilation system was sized to maintain a positive pressure in the TSC of 0. 125 inches of water.... Closing the isolation dampers enables 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 and prevent infiltration of outside air.

However, during TSC ventilation testing, it was determined that a fixed filter fan speed is necessary to maintain positive pressure as opposed to a modulated fan speed. Also, it was observed that while the positive pressure value of 0.125 inches of water could be attained, this value could be challenged due to seasonal temperature changes.

Consequently, to prevent outside air infiltration going forward, the TSC positive pressure minimum value has been revised as follows: the occupied TSC space will be maintained at~ 0.10 inches of water relative to outside air pressure, and the TSC penthouse, which is not an occupied space, will be maintained at~ 0.05 inches of water relative to outside

Serial No.: 24-319 Docket Nos.: 50-280/281 Page 2 of 3 air pressure. These changes to the TSC ventilation system do not impact the TSC dose analysis since the dose analysis only assumes the TSC is maintained at a positive pressure.

Furthermore, page 18 of the NRG safety evaluation included in TS Amendments 315 and 315 for SPS Units 1 and 2, respectively, states, "the licensee states that to limit the infiltration of airborne radioactivity, the TSC emergency ventilation system is designed to provide a filtered makeup air flow rate to maintain the TSC habitability envelope at a positive pressure.... " This statement remains valid with the updated positive pressure values and fixed fan speed; therefore, the conclusions of the NRG safety evaluation are not affected by the TSC ventilation design changes.

The changes discussed above are provided for the NRC's information and are similar to those previously provided for the relocated North Anna Power Station (NAPS) TSC by letter dated February 9, 2024 (ADAMS Accession No. ML24043A144). The NAPS TSC relocation was approved in the NRG safety evaluation included in Amendments 296 and 279 for NAPS Units 1 and 2, respectively (ADAMS Accession No. ML24005A004), which also notes the TSC will be maintained at a positive pressure during an emergency.

Should you have any questions or require additional information, please contact Mr. Gary D. Miller at (804) 273-2771.

Respectfully, C)~-}(~)**

James E. Holloway Vice President-Nuclear Engineering and Fleet Support Commitments contained in this letter: None.

COMMONWEAL TH OF VIRGINIA )

)

COUNTY OF HENRICO

)

KATHRYN HILL BARRET NOTAAY PUBLIC COMMONWEALTH OF VIRGINIA MY COMMISSION EXPIRES JANUARY 31, 2028 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.

Acknowledged before me this I~+~

day of NoYel"r'l'oeY'"

, 2024.

My Commission Expires: "3"anuaY'"'i "t> l 1 202...8

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. 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 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 NRC Senior Resident Inspector Surry Power Station State Health Commissioner Virginia Department of Health James Madison Building - 7th floor 109 Governor Street, Suite 730 Richmond, Virginia 23219 Serial No.: 24-319 Docket Nos.: 50-280/281 Page 3 of 3