ML14115A287
| ML14115A287 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 05/09/2014 |
| From: | Leeds E Office of Nuclear Reactor Regulation |
| To: | James Shea Tennessee Valley Authority |
| Saba F DORL/LPL2-2 301-415-1447 | |
| References | |
| TAC MF3620, TAC MF3621, TAC MF3622 | |
| Download: ML14115A287 (4) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 Mr. Joseph W. Shea Vice President - Nuclear Licensing Tennessee Valley Authority 1101 Market Street, LP 3D-C Chattanooga, TN 37 402-2801 May 9, 2014
SUBJECT:
BROWNS FERRY NUCLEAR PLANT UNITS 1, 2, AND 3-RELAXATION OF RESPONSE DUE DATES REGARDING FLOODING HAZARD REEVALUATIONS FOR RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE REVIEW OF THE INSIGHTS FROM THE FUKUSHIMA DAI-ICHI ACCIDENT (TAC NOS.
MF3620, MF3621, AND MF3622)
Dear Mr. Shea:
By letter dated March 12, 2012, 5 the Nuclear Regulatory Commission (NRC) issued a request for information under Title 10 of the Code of Federal Regulations, Section 50.54(f) (hence referred to as the 50.54(f) letter). The agency issued the request as a part of implementing lessons-learned from the accident at the Fukushima Dai-ichi nuclear power plant. Enclosure 2 to the 50.54(f) letter requested licensees to perform a reevaluation of all external flooding hazards using present-day guidance and methodologies.
By letter dated May 11, 2012,6 the NRC issued a prioritization of due dates for all sites. For Browns Ferry Nuclear Plant, Units 1, 2, and 3 (Browns Ferry or BFN), the NRC set the flooding hazard reevaluation due date for March 12, 2014.
By letter dated March 11, 2014,7 Tennessee Valley Authority (TVA) requested a 1-year extension to the submittal schedule for the flooding hazard reevaluation for Browns Ferry with a new due date of March 12, 2015. As justification for the request, TVA stated that it would require additional time to complete the evaluation of 21 upstream dams and 1 downstream dam in order to fully assess the flood hazard for the Browns Ferry site. In its letter, TVA described a number of additional factors to justify the new schedule.
During a conference call between the NRC staff and TVA held on April 1, 2014, the NRC staff requested that TVA provide a detailed schedule for completing the Browns Ferry flooding hazard reevaluation. By letter dated April 7, 2014,8 TVA provided the requested schedule.
5 The 50.54(f) letter is available in the Agencywide Documents Access and Management System (ADAMS) under Accession No. ML12053A340.
6 The prioritization letter is available under ADAMS Accession No. ML12097A509.
7 The extension request from TVA is available under ADAMS Accession No. ML14071A094.
8 The schedule for completing the Browns Ferry flooding hazard reevaluations from TVA is available under ADAMS Accession No. ML14098A152.
J.Shea The NRC staff reviewed TVA's justification and considered the following factors when reviewing the new schedule:
TVA operates the Tennessee River reservoir system and has extensive experience and expertise in managing river and stream flooding scenarios. TVA staffs a River Forecasting Center (RFC) 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> a day to monitor and manage the system through a continuous process. The operating plan, referred to as a river forecast, is monitored and modified as necessary to meet operating objectives to the extent possible. The current plan is monitored by checking observed discharges and reservoir elevations against those that were planned, and modifications are made in response to changing demands on the system (e.g., more or less hydropower needed) and changes in weather that result in more or less streamflow coming into the reservoir than was anticipated when the current reservoir forecast was developed.
The RFC has a standard operating procedure that is used to document the required notifications and actions during flood or other hydrological events that may threaten safe operation of TVA nuclear facilities. Included in that standard operating procedure are instructions to notify Browns Ferry when certain potential flooding scenarios are forecasted.
By procedure, TVA staff at Browns Ferry contacts the staff at the RFC when the Wheeler Reservoir is observed to be at elevation 558 feet or greater. The staff at the RFC will then give an estimate of the peak river level and, if the river level is predicted to rise above elevation 565 feet, TVA will commence all Browns Ferry operating units to cold shutdown conditions.
By letter dated July 1, 2013,9 the NRC granted TVA's request for relaxation of the response dates for Sequoyah Nuclear Plant, Units 1 and 2 (SQN) and Watts Bar Nuclear Plant, Units 1 and 2 (WBN). The flooding hazard reevaluation for SQN and WBN was revised to March 12, 2015. The letter also stated that "[t]he BFN assignment [a year later] considered that the hazard reevaluation of SON and WBN, which are upstream of BFN, would likely be an input to the BFN hazard reevaluation."
The licensee will submit quarterly reports on the status of the Browns Ferry hazard reevaluation.
The detailed schedule submitted by TV A provides assurance that it will complete the Browns Ferry hazard reevaluation by March 12, 2015.
The requested extension to March 12, 2015, will allow TVA to provide the information requested in the 50.54(f) letter in a time frame similar to sites with complex flooding hazards. For the majority of sites with evaluations that are expected to be particularly complex (e.g., sites with coastal flooding hazards), the NRC assigned a due date of March 12, 2015. This is consistent with TVA's requested due date.
9 The NRC relaxation approval letter for SQN and WBN is available under ADAMS Accession No. ML13163A296.
Given these considerations, the NRC considers TVA's proposed revised schedule to be acceptable. Accordingly, and based upon the authority granted to the Director of the NRC's Office of Nuclear Reactor Regulation, the required response date for submitting the hazard reevaluation report for Browns Ferry is now March 12, 2015.
Docket Nos. 50-259, 50-260, and 50-296 cc: Listserv Sincerely,
- L~
Office of Nuclear Reactor Regulation
ML14115A287 Sincerely, IRA/
Eric J. Leeds, Director Office of Nuclear Reactor Regulation RidsNrrDorl MMitchell, JLD RidsNrrOd DSkeen, JLD GEMiller, NRR RTaylor, JLD RKuntz, JLD RidsNrrPMBrownsFerry
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