CNL-24-080, Response to Request for Additional Information Regarding Application to Revise Updated Final Safety Analysis Report Regarding Changes to Hydrologic Analysis (WBN-19-011)
| ML24325A470 | |
| Person / Time | |
|---|---|
| Site: | Watts Bar  |
| Issue date: | 11/20/2024 |
| From: | Hulvey K Tennessee Valley Authority |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| References | |
| CNL-24-080, EPID L-2024-LLA-0006 | |
| Download: ML24325A470 (1) | |
Text
10 CFR 50.90 1101 Market Street, Chattanooga, Tennessee 37402 CNL-24-080 November 20, 2024 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555-0001 Watts Bar Nuclear Plant, Units 1 and 2 Facility Operating Licenses Nos. NPF-90 and NPF-96 NRC Docket Nos. 50-390 and 50-391
Subject:
Response to Request for Additional Information Regarding Application to Revise Watts Bar Nuclear Plant, Units 1 and 2 Updated Final Safety Analysis Report Regarding Changes to Hydrologic Analysis (WBN-19-011) (EPID L-2024-LLA-0006)
References:
- 1. TVA letter to NRC, CNL-23-005, Application to Revise Watts Bar Nuclear Plant Units 1 and 2 Updated Final Safety Analysis Report Regarding Changes to Hydrologic Analysis (WBN-19-011), dated December 26, 2023 (ML24003A270)
- 2. NRC electronic mail to TVA, Request for Additional Information - LAR to Revise Watts Bar UFSAR for Hydrologic Analysis (EPID L-2024-LLA-0006), dated October 29, 2024 (ML24304A375)
In Reference 1, Tennessee Valley Authority (TVA) submitted a request for an amendment to Facility Operating License Nos. NPF-90 and NPF-96 for the Watts Bar Nuclear Plant (WBN), Units 1 and 2, respectively. The proposed change revises the WBN Units 1 and 2 Updated Final Safety Analysis Report (UFSAR) to reflect the results from a new hydrologic analysis.
In Reference 2, the Nuclear Regulatory Commission issued a request for additional information (RAI) and requested that TVA respond by November 28, 2024.
The enclosure to this submittal provides the response to the RAI.
This letter does not change the no significant hazard consideration nor the environmental consideration contained in Reference 1. Additionally, in accordance with Title 10 of the Code of Federal Regulations (10 CFR) 50.91(b)(1), TVA is sending a copy of this letter and enclosures to the Tennessee State Department of Environment and Conservation.
U.S. Nuclear Regulatory Commission CNL-24-080 Page 2 November 20, 2024 There are no new regulatory commitments in this letter. Please address any questions regarding this submittal to Amber V. Aboulfaida, Senior Manager, Fleet Licensing, at avaboulfaida@tva.gov.
I declare under penalty of perjury that the foregoing is true and correct. Executed on the 20th day of November 2024.
Respectfully, Kimberly D. Hulvey General Manager, Nuclear Regulatory Affairs & Emergency Preparedness
Enclosure:
Response to Request for Additional Information (RAI) cc (Enclosure):
NRC Regional Administrator - Region II NRC Senior Resident Inspector - Watts Bar Nuclear Plant NRC Project Manager - Watts Bar Nuclear Plant Director, Division of Radiological Health - Tennessee State Department of Environment and Conservation Digitally signed by Edmondson, Carla Date: 2024.11.20 11:28:20 -05'00'
Enclosure Response to Request for Additional Information (RAI)
Enclosure CNL-24-080 E1 of 1 NRC 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 [sic] 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.
TVA Response The PMF elevation listed in the proposed revision of WBN UFSAR Section 2.4.14 is based on calculation CDQ0000002017000070, Probable Maximum Flood (PMF) Results Summary, Revision 2, listed as Reference 71 in Enclosure 8 of the LAR.
To allow for potential anomalies in the model or inputs that may be identified in the future, this value is 0.5 ft higher than the calculated maximum water surface elevation listed in CDQ0000002017000062, Revision 1.