ML24304A375

NRR E-mail Capture - Request for Additional Information - License Amendment Request (LAR) to Revise Watts Bar Updated Final Safety Analysis Report (UFSAR) for Hydrologic Analysis

ML24304A375
Person / Time
Site:	Watts Bar
Issue date:	10/29/2024
From:	Kimberly Green Plant Licensing Branch II
To:	Taylor A Tennessee Valley Authority
References
L-2024-LLA-0006
Download: ML24304A375 (3)

Text

From:

Kimberly Green Sent:

Tuesday, October 29, 2024 3:31 PM To:

Taylor, Andrew Charles Cc:

Hughes, Shawna Marie

Subject:

Request for Additional Information - LAR to Revise Watts Bar UFSAR for Hydrologic Analysis (EPID L-2024-LLA-0006)

Attachments:

WBN Hydrology LAR RAI.docx

Dear Andy Taylor,

By application dated December 26, 2023 (Agencywide Documents and Access Management System Accession No. ML24003A270), Tennessee Valley Authority (TVA) submitted a license amendment request (LAR) to the U.S. Nuclear Regulatory Commission (NRC) that requested amendments to Facility Operating License Nos. NPF-90 and NPF-96 for Watts Bar Nuclear Plant, Units 1 and 2 (Watts Bar), respectively. Specifically, the proposed amendments would revise the Watts Bar Dual-Unit Updated Final Safety Analysis Report (UFSAR) to reflect the results from a new hydrologic analysis.

The U.S. Nuclear Regulatory Commission (NRC) staff began its review of TVAs application and determined that an audit would be beneficial to aid in the staffs review and allow the staff to confirm referenced information. The NRC staff and its contractor, Oak Ridge National Laboratory, conducted a remote audit from October 15 through October 17. Based on the results of the audit, the NRC identified an area where additional information is needed to complete its review. The draft request for additional information (RAI) was communicated to TVA during the audit exit call on October 28th. TVA indicated that a clarification call was not necessary.

A response to the attached RAI is requested within 30 days of the date of this email. The NRC staff considers that timely responses to RAIs help ensure sufficient time is available for staff review and contribute toward the NRCs goal of efficient and effective use of staff resources. If circumstances result in the need to revise the requested response date, please me at (301) 415-1627 or via email at Kimberly.Green@nrc.gov.

Kimberly Green Senior Project Manager Division of Operating Reactor Licensing U.S. Nuclear Regulatory Commission 301-415-1627

Hearing Identifier:

NRR_DRMA Email Number:

2633 Mail Envelope Properties (SA1PR09MB91639ECCFAF8CC851F78269F8F4B2)

Subject:

Request for Additional Information - LAR to Revise Watts Bar UFSAR for Hydrologic Analysis (EPID L-2024-LLA-0006)

Sent Date:

10/29/2024 3:31:18 PM Received Date:

10/29/2024 3:31:00 PM From:

Kimberly Green Created By:

Kimberly.Green@nrc.gov Recipients:

"Hughes, Shawna Marie" <smhughes@tva.gov>

Tracking Status: None "Taylor, Andrew Charles" <actaylor@tva.gov>

Tracking Status: None Post Office:

SA1PR09MB9163.namprd09.prod.outlook.com Files Size Date & Time MESSAGE 1849 10/29/2024 3:31:00 PM WBN Hydrology LAR RAI.docx 43394 Options Priority:

Normal Return Notification:

No Reply Requested:

No Sensitivity:

Normal Expiration Date:

REQUEST FOR ADDITIONAL INFORMATION TENNESSEE VALLEY AUTHORITY WATTS BAR NUCLEAR PLANT, UNITS 1 AND 2 DOCKET NOS. 50-390 AND 50-391 HYDROLOGIC ANALYSIS

==

Introduction:==

By application dated December 26, 2023 (Agencywide Documents and Access Management System Accession No. ML24003A270), Tennessee Valley Authority (TVA) submitted a license amendment request (LAR) to the U.S. Nuclear Regulatory Commission (NRC) that requested amendments to Facility Operating License Nos. NPF-90 and NPF-96 for Watts Bar Nuclear Plant, Units 1 and 2 (Watts Bar), respectively. Specifically, the proposed amendments would revise the Watts Bar Dual-Unit Updated Final Safety Analysis Report (UFSAR) to reflect the results from a new hydrologic analysis.

Regulatory Basis:

The regulation at 50.34(b) of Title 10 of the Code of Federal Regulations (10 CFR), requires, in part, that the final safety analysis report (FSAR) shall include information that describes the facility, presents the design bases and the limits on its operation, and presents a safety analysis of the structures, systems, and components and of the facility as a whole.

The regulation at 10 CFR 50.71(e) requires, in part, that licensees periodically update the FSAR originally submitted as part of the application for the license, to assure that the information included in the report contains the latest information developed. This submittal shall contain all the changes necessary to reflect information and analyses submitted to the Commission by the applicant or licensee or prepared by the applicant or licensee pursuant to Commission requirement since the submittal of the original FSAR, or as appropriate, the last update to the FSAR under this section.

Request:

The LAR included calculation CDQ0000002017000062, Revision 1, Fort Loudon Dam (FLH) and Tellico Dam (TEC) Probably Maximum Flood (PMF) Analysis, (security-related, not publicly available). The LAR also included proposed mark-ups of section 2.4 of the Watts Bar Dual-Unit UFSAR.

The calculated PMF elevation (still reservoir) at the Watts Bar site proposed to be revised in section 2.4.14 of Watts Bar Dual-Unit UFSAR is 0.5 ft higher than the maximum peak water surface elevation in calculation CDQ0000002017000062, Revision 1; however, a reason for this difference was not provided in the LAR.

Provide an explanation for the 0.5 ft difference in the two maximum flood elevations.