CNL-18-136, Plants: Tennessee Valley Authority - Hydrologic Engineering Center River Analysis System (HEC-RAS) Project Milestone Status Update

Plants: Tennessee Valley Authority - Hydrologic Engineering Center River Analysis System (HEC-RAS) Project Milestone Status Update

ML18361A803
Person / Time
Site:	Browns Ferry, Watts Bar, Sequoyah
Issue date:	12/27/2018
From:	Henderson E Tennessee Valley Authority
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
CNL-18-136
Download: ML18361A803 (3)

Text

Tennessee Valley Authority, 1101 Market Street, Chattanooga, Tennessee 37402 CNL-18-136 December 27, 2018 10 CFR 50.4 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555-0001 Browns Ferry Nuclear Plant, Units 1, 2, and 3 Renewed Facility Operating License Nos. DPR-33, DPR-52, and DPR-68 NRC Docket Nos. 50-259, 50-260, and 50-296 Sequoyah Nuclear Plant, Units 1 and 2 Renewed Facility Operating License Nos. DPR-77 and DPR-79 NRC Docket Nos. 50-327 and 50-328 Watts Bar Nuclear Plant, Units 1 and 2 Facility Operating License Nos. NPF-90 and NPF-96 NRC Docket Nos. 50-390 and 50-391

Subject:

TENNESSEE VALLEY AUTHORITY - HYDROLOGIC ENGINEERING CENTER RIVER ANALYSIS SYSTEM (HEC-RAS) PROJECT MILESTONE STATUS UPDATE

Reference:

TVA letter to NRC, Tennessee Valley Authority - Hydrologic Engineering Center River Analysis System (HEC-RAS) Project Milestones, dated June 22, 2016 (ML16175A518)

By letter dated June 22, 2016, Tennessee Valley Authority (TVA) provided NRC with dates for several project deliverables associated with the ongoing HEC-RAS external flood modeling project (referenced letter). The HEC-RAS external flood modeling project was the subject of an April 4, 2016 public meeting to discuss technical details and a resolution plan for TVAs HEC-RAS external flood modelling issues. In the referenced letter, TVA committed to provide updates on the status of the specific project deliverables on a six-month frequency.

U.S. Nuclear Regulatory Commission CNL-18-136 Page 2 December 27, 2018 The purpose of this letter is to provide the fifth written update regarding the status of the project milestones consistent with the commitment made in the referenced letter.

There has been no change in milestone status since the update provided by letter dated June 22, 2018 (ML18178A432).

TABLE 1 PROJECT DELIVERABLE SUBMITTAL MILESTONES Submittal Project Deliverable Milestone 1 Browns Ferry Mitigating Strategies Assessment (MSA) Complete 2 Sequoyah MSA Complete 3 Watts Bar MSA Complete 4 Watts Bar Focused Evaluation (FE) April 2019 5 Sequoyah FE April 2019 6 Browns Ferry FE April 2019 7 Sequoyah Hydrology License Amendment Request (LAR) April 2019 8 Watts Bar Hydrology LAR May 2019 The calculations, analyses, and evaluations being performed in support of Tasks 4 - 8 are fundamentally based on precipitation values in Topical Report TVA-NPG-AWA16, TVA Overall Basin Probable Maximum Precipitation and Local Intense Precipitation Analysis, Calculation CDQ0000002016000041. This topical report was submitted to NRC for review by letter dated September 20, 2016. Resolution of several technical issues from NRCs review was achieved by revisions to the topical report. Topical Report TVA-NPG-AWA16, Revision 1, was submitted by letter dated June 22, 2018. Accordingly, the milestone dates for Tasks 4 - 8 reflect the required rework and TVAs current estimate for completion of the corresponding analyses and evaluations in support of these tasks.

U.S. Nuclear Regulatory Commission CNL-18-136 Page 3 December 27, 2018 The projected milestones for the submittal of the Sequoyah and Watts Bar Hydrology LARs will be discussed with the NRC Project Manager.

TVA will provide the sixth status update on these project deliverable submittal milestones by June 30, 2019, consistent with the Commitment made in the referenced letter.

There are no new regulatory commitments contained in this letter.

If additional information is needed regarding this update, please contact Russell Thompson at (423) 751-2567.

Respectfully, E. K. Henderson Director, Nuclear Regulatory Affairs cc:

NRR Director - NRC Headquarters NRC Regional Administrator - Region II NRC Project Manager - Browns Ferry Nuclear Plant NRC Project Manager - Sequoyah Nuclear Plant NRC Project Manager - Watts Bar Nuclear Plant NRC Senior Resident Inspector - Browns Ferry Nuclear Plant NRC Senior Resident Inspector - Sequoyah Nuclear Plant NRC Senior Resident Inspector - Watts Bar Nuclear Plant