ML103190360

Closeout of Generic Letter 2008-01 Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems

ML103190360
Person / Time
Site:	Sequoyah
Issue date:	04/22/2011
From:	Siva Lingam Plant Licensing Branch II
To:	Krich R Tennessee Valley Authority
Lingam, S NRR/DORL 415-1564
References
TAC MD7879, TAC MD7880, GL-08-001
Download: ML103190360 (4)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 April 22. 2011 Mr. Rodney M. Krich Vice President, Nuclear Licensing Tennessee Valley Authority 3R Lookout Place 1101 Market Street Chattanooga, TN 37402-2801

SUBJECT:

SEQUOYAH NUCLEAR PLANT, UNITS 1 AND 2 - CLOSEOUT OF GENERIC LETTER 2008-01 "MANAGING GAS ACCUMULATION IN EMERGENCY CORE COOLING, DECAY HEAT REMOVAL, AND CONTAINMENT SPRAY SYSTEMS" (TAC NOS. MD7879 AND MD7880)

Dear Mr. Krich:

On January 11, 2008, the U.S. Nuclear Regulatory Commission (NRC) issued Generic Letter (GL) 2008-01, "Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems" (Agencywide Documents Access and Management System (ADAMS) Accession No. ML072910759) The stated purpose of GL 2008-01 was (a) to request addressees to submit information to demonstrate that the subject systems are in compliance with the current licensing and design bases and applicable regulatory requirements, and that suitable design, operational, and testing control measures are in place for maintaining this compliance; and, (b) to collect the requested information to determine if additional regulatory action is required.

GL 2008-01 requested that licensees provide the following information within 9 months of the date of the GL:

(a) A description of the results of evaluations that were performed pursuant to requested actions specified in the GL. This description should provide sufficient information to demonstrate that you are or will be in compliance with the quality assurance criteria in Sections III, V, XI, XVI and XVII of Appendix B to Title 10 of the Code of Federal Regulations, Part 50 and the licensing basis and operating license as those requirements apply to the subject systems; (b) A description of all corrective actions, including plant, programmatic, procedure. and licensing basis modifications that you determined were necessary to assure compliance with these regulations; and, (c) A statement regarding which corrective actions were completed, the schedule for completing the remaining corrective actions, and the basis for that schedule.

In Item c, licensees typically had to wait for a refueling outage to access parts of the plant that were inaccessible at power. Consequently, Tennessee Valley Authority (TVA the licensee) provided or plans to provide supplementary responses following the outage.

R. Krich -2 By letters dated October 11, 2008, July 24, 2009, February 19, 2010, and July 15, 2010 (ADAMS Accession Nos. ML082890540, ML092080447, ML100541590, and ML102010061 respectively)

TVA provided responses to GL 2008-01 for Sequoyah Nuclear Plant (SON), Units 1 and 2. The NRC staff has reviewed the licensee responses and has documented the evaluation in "Suggestions for the Sequoyah Nuclear Plant (SON) Inspection Using the Guidance Provided in Temporary Instruction [Til 2515/177" (ML102090699, non-publicly available). The NRC staff determined that the licensee has acceptably addressed each request.

The licensee's Technical Specifications require the licensee to demonstrate that the Emergency Core Cooling System (ECCS) is operable at least once per 31 days by verifying the system piping is filled with water through venting from high point vents. In addition, the licensee stated "current procedures require ultrasonic level measurement at specific locations on a monthly (Le., 31-day) basis." Based upon the current surveillance requirements and evaluation history, the NRC staff finds that the licensee has demonstrated that these systems are currently operable.

SON uses its corrective actions program (CAP) to document gas intrusion/accumulation issues.

The CAP process identifies relevant plant equipment for evaluation and potential impact on operability and reportability. Whenever a void is found through venting or ultrasonic testing (UT),

a Problem Evaluation Report is created and the void is trended by the ECCS system engineer.

SON has incorporated gas intrusion and its consequences into its operations and maintenance training program. Engineering provided plant-specific examples of methods employed to control gas accumulation. The NRC staff finds that SON is effectively using its CAP process to demonstrate current operability.

The NRC staff has concluded that the licensee has acceptably demonstrated "that gas accumulation is maintained less than the amount that challenges operability of these systems, and that appropriate action is taken when conditions adverse to quality are identified," as stated in GL 2008-01. We are continuing to engage with stakeholders regarding the creation of durable guidance for Gas Management that may require additional actions by the licensee beyond the scope of GL 2008-01.

The NRC staff has completed the GL 2008-01 review and has concluded that the subject systems are currently operable. Notwithstanding, the NRC's Region II staff may decide to perform (and would contact you to schedule) an inspection using TI 2515/177, "Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems (NRC Generic Letter 2008-01)" (ADAMS Accession No. ML082950666) to assess applicable information that is available at the plant and to confirm our conclusion or, conversely, to identify items where additional follow-up is necessary to confirm our conclusion. The TI 2515/177 is confirmatory in nature in that it directs NRC inspectors to selectively verify that the licensee has implemented or is in the process of acceptably implementing the commitments, modifications, and programmatically control/ed actions described in the licensee's response to GL 2008-01 and the plant-specific information supports a conclusion that the subject systems operability is reasonably ensured.

R. Krich -3 If you have any questions, please contact Siva P Lingam at 301-415-1564.

Sincerely .

~ ~,. ~{J~'--

Siva P Lingam, Project Manager Plant Licensing Branch 11-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-327 and 50-328 cc: Distribution via ListServ

R. Krich - 3 If you have any questions, please contact Siva P. Lingam at 301-415-1564.

Sincerely, IRA!

Siva P. Lingam, Project Manager Plant Licensing Branch 11-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-327 and 50-328 cc: Distribution via ListServ Distribution:

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