ML20293A080

Summary of October 13, 2020, Closed Meeting with TVA on Responses to Requests for Additional Information Updated Final Safety Analysis Report Hydrologic Analysis License Amendment Request

ML20293A080
Person / Time
Site:	Sequoyah
Issue date:	10/28/2020
From:	Michael Wentzel Plant Licensing Branch II
To:
Wentzel M
References
EPID L-2020-LLA-0004
Download: ML20293A080 (4)

Text

October 27, 2020 LICENSEE: Tennessee Valley Authority FACILITY: Sequoyah Nuclear Plant, Units 1 and 2

SUMMARY

OF OCTOBER 13, 2020, CLOSED MEETING WITH TENNESSEE VALLEY AUTHORITY TO DISCUSS RESPONSES TO REQUESTS FOR ADDITIONAL INFORMATION REGARDING UPDATED FINAL SAFETY ANALYSIS REPORT HYDROLOGIC ANALYSIS LICENSE AMENDMENT REQUEST (EPID L-2020-LLA-0004)

On October 13 2020, the U.S. Nuclear Regulatory Commission (NRC) staff held a closed meeting with representatives of Tennessee Valley Authority (the licensee) to discuss the licensees plan for responding to the staffs July 1, 2020, request for additional information (Agencywide Documents Access and Management System (ADAMS) Accession No. ML20189A211) issued in response to the licensees request to modify the Sequoyah Nuclear Plant, Units 1 and 2 (Sequoyah), Updated Final Safety Analysis Report hydrologic analysis (ADAMS Accession No. ML20016A396). The meeting was closed to allow for the discussion of proprietary and security-related information. The meeting notice and agenda for this meeting, dated September 29, 2020, are available at ADAMS Accession No. ML20273A205.

This was a follow-on meeting to the July 16, 2020, meeting. The summary for that meeting is available at ADAMS Accession No. ML20203M229. A list of attendees to the October 13, 2020, meeting is enclosed. No regulatory decisions were made at this meeting.

During the meeting, the licensee provided an overview of its planned responses to the NRC staffs remaining requests for additional information. During the presentation, the licensee stated that it intended to replace the Microsoft Excel Visual Basic for Applications macros it had previously used to verify the output of the Probable Maximum Precipitation (PMP) Evaluation Tool as part of its commercial grade dedication of this tool with independent manual computations across a subset of areal values. The licensee stated that the manual computations will be used to validate the PMP Evaluation Tool functions. Given that the dedication using the testing methodology for the PMP Evaluation Tool is not limited to those outputs validated by the tests performed, the NRC staff stated that the licensee should provide the technical basis for why the selected areal values for the set of tests used to verify the validity of the PMP Evaluation Tool functions are appropriate to the Sequoyah water basins.

Additionally, the NRC staff stated that it would likely want to perform a regulatory audit of the licensees computations.

The licensee also provided the NRC staff an overview of a recently identified, potentially unconservative assumption that impacts one of the analyses supporting the license amendment request. The licensee stated that it was considering alternatives to address the potentially unconservative assumption and revise the affected analysis prior to making it available to the NRC staff for review.

Please direct any inquiries to me at 301-415-6459 or Michael.Wentzel@nrc.gov.

/RA/

Michael J. Wentzel, Project Manager Plant Licensing Branch II-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-327 and 50-328

Enclosure:

List of Attendees cc: Listserv

ML20293A080 OFFICE NRR/DORL/LPL2-2/PM NRR/DORL/LPL2-2/LA NRR/DORL/LPL2-2/BC NRR/DORL/LPL2-2/PM BAbeywickrama NAME MWentzel UShoop MWentzel (LRonewicz for)

DATE 10/26/2020 10/22/2020 10/26/2020 10/27/2020 LIST OF ATTENDEES OCTOBER 13, 2020, CLOSED MEETING WITH TENNESSEE VALLEY AUTHORITY REGARDING THE UPDATED FINAL SAFETY ANALYSIS REPORT HYDROLOGIC ANALYSIS LICENSE AMENDMENT REQUEST FOR SEQUOYAH NUCLEAR PLANT, UNITS 1 AND 2 Name Organization Hosung Ahn U.S. Nuclear Regulatory Commission (NRC)

Bob Bernardo NRC Yuan Cheng NRC Kim Green NRC Kerri Kavanagh NRC Mike Lee NRC Paul Prescott NRC Kevin Quinlan NRC Michael Wentzel NRC Deanna Zhang NRC Scott DeNeale Oak Ridge National Laboratory Sudershan Gangrade Oak Ridge National Laboratory Shih-Chieh Kao Oak Ridge National Laboratory Laura Groce Tennessee Valley Authority (TVA)

Husein Hasan TVA Dennis Lundy TVA Karl Nesmith TVA Penny Selman TVA Brenda Simril TVA Tom Spink TVA Andrew Taylor TVA Russ Wells TVA Gordon Williams TVA Robert Blackwell Barge Design Solutions Trevor Cropp Barge Design Solutions Stu Henry Barge Design Solutions Janelle Schlamp Barge Design Solutions Heather Sawyer Barge Design Solutions Enclosure