ML13163A296
| ML13163A296 | |
| Person / Time | |
|---|---|
| Site: | Watts Bar, Sequoyah  |
| Issue date: | 07/01/2013 |
| From: | Leeds E Office of Nuclear Reactor Regulation |
| To: | James Shea Tennessee Valley Authority |
| Miller G | |
| References | |
| Download: ML13163A296 (4) | |
Text
July 1, 2013 J. W. Shea Vice President, Nuclear Licensing Tennessee Valley Authority 1101 Market Street Chattanooga, TN 37402
SUBJECT:
SEQUOYAH NUCLEAR PLANT, UNITS 1 AND 2, AND WATTS BAR NUCLEAR PLANT, UNITS 1 AND 2 - 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
Dear Mr. Shea:
By letter dated March 12, 2012,1 the Nuclear Regulatory Commission (NRC) issued a request for information pursuant to Title 10 of the Code of Federal Regulations, Section 50.54(f) (hence referred to as the 50.54(f) letter). The request was issued 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, 2012,2 the NRC issued a prioritization of due dates for all sites. The flooding hazard reevaluation was due on March 12, 2013, for Sequoyah Nuclear Plant (SQN),
Units 1 and 2, and Watts Bar Nuclear Plant (WBN), Units 1 and 2.
By letter dated March 12, 2013,3 Tennessee Valley Authority (TVA), requested an extension to the submittal schedule for the flooding hazard reevaluation for SQN and WBN to May 29, 2015.
The reason for this request is to allow additional time to complete the evaluation of seventeen upstream dams and one downstream dam in order to fully assess the flood hazard for the SQN and WBN sites. In its letter, TVA described a number of additional factors to justify the new schedule.
On April 29, 2013, TVA met with the NRC in a public meeting to discuss the details of its extension request.4 As a result of the discussions at this meeting, TVA agreed to reduce the length of the extension request and support more frequent status notifications. By letter dated May 9, 2013,5 TVA updated its requested submittal schedule to March 12, 2015, and agreed to provide status on a quarterly frequency.
1 The 50.54(f) letter is available in the Agencywide Documents Access and Management System (ADAMS) under Accession No. ML12053A340.
2 The prioritization letter is available under ADAMS Accession No. ML12097A509.
3 The extension request from TVA is available under ADAMS Accession No. ML13080A073.
4 The public meeting summary is available under ADAMS Accession No. ML13141A543.
5 The supplement to the extension request is available under ADAMS Accession No. ML13133A004.
J. Shea The NRC reviewed the justification provided and considered the following factors when reviewing the new schedule:
At the time the 50.54(f) letter was drafted, the licensee was performing reevaluations of flood hazards in conjunction with separate, ongoing regulatory activities. Because these reevaluations were in progress, it was anticipated that TVA would be able to submit their hazard reevaluation report in response to the 50.54(f) letter in a shorter timeline than was assigned to sites of similar hazard complexity but that did not have ongoing activity related to reevaluation of flood hazards. However, as indicated in the extension request provided by TVA, the evaluations performed in conjunction with these other regulatory activities are not as comprehensive as the methodologies chosen to respond to the NRCs March 12, 2012, 50.54(f) letter. As a result, additional time is requested by TVA to complete the flooding hazard assessment for SQN and WBN, and to migrate Tennessee River modeling from the Simulated Open Channel Hydraulic (SOCH) code to the U.S. Army Corps of Engineers Hydraulic Engineering Center River Analysis System (HEC-RAS) program.
The licensee has proposed a number of activities to support the proposed schedule including: submission of quarterly status reports, supplementing existing site flood protection with installation of permanent plant modifications by March 2013, and performance drills at both plants by December 2013.
The requested extension to March 12, 2015, will provide the information requested in the 50.54(f) letter in a time frame similar to sites with complex flooding hazards. The majority of sites with evaluations that are expected to be particularly complex (e.g., sites with coastal flooding hazards) have been assigned a due date of March 12, 2015, which is consistent with the revised due date requested by TVA.
As was discussed in the April 29, 2013, public meeting, the Browns Ferry Nuclear (BFN) hazard reevaluation is currently assigned a due date of March 12, 2014, which is now before that of the SQN and WBN hazard reeanalysis. The BFN assignment considered that the hazard reevaluation of SQN and WBN, which are upstream of BFN, would likely be an input to the BFN hazard reevaluation. In anticipation of a potential extension request for BFN, and acknowledging the hydrologic relationship between the hazard reevaluations at these three sites, the NRC staff maintains an expectation that all hazard reevaluation reports be submitted on, or before, March 12, 2015.
J. Shea Given these considerations, the NRC considers the revised schedule proposed by TVA to be acceptable. Accordingly, and based upon the authority granted to the Director, Office of Nuclear Reactor Regulation, the revised required response date for submitting the hazard reevaluation report for SQN and WBN is March 12, 2015.
Sincerely,
/RA/
Eric J. Leeds, Director Office of Nuclear Reactor Regulation Docket Nos. 50-327, 50-328, 50-390 and 50-391 cc: Listserv
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