ML15217A328

Review of the Steam Generator Tube Inservice Inspections for Cycle 19 Refueling Outage in 2014

ML15217A328
Person / Time
Site:	Sequoyah
Issue date:	08/26/2015
From:	Andrew Hon Plant Licensing Branch II
To:	John Carlin Tennessee Valley Authority
Andrew Hon, 415-8480
References
TAC MF5422
Download: ML15217A328 (3)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 August 26, 2015 Mr. John T. Carlin Site Vice President Sequoyah Nuclear Plant Tennessee Valley Authority P.O. Box 2000, OPS 4A-SQN Soddy Daisy, TN 37384-2000

SUBJECT:

SEQUOYAH NUCLEAR PLANT, UNIT 2 - REVIEW OF THE STEAM GENERATOR TUBE INSERVICE INSPECTIONS FOR CYCLE 19 REFUELING OUTAGE IN 2014 (TAC NO. MF5422)

Dear Mr. Carlin:

By letters dated December 1, 2014 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML14342B004) and May 29, 2015 (ADAMS Accession No. ML15156A388, which includes ML15156A389), Tennessee Valley Authority (TVA) submitted information summarizing the results of the spring 2014 steam generator tube inspections performed at the Sequoyah Nuclear Plant (Sequoyah), Unit 2. These inspections were performed during refueling outage 19.

The U.S. Nuclear Regulatory Commission (NRC) staff has reviewed the information TVA provided and concludes it contains the information required by the Sequoyah, Unit 2, technical specifications and that no additional followup is required at this time. The NRC staff review of the steam generator portions of the report is enclosed.

If you have any questions, please contact me at (301) 415-8480 or Andrew.Hon@nrc.gov.

Sincerely, Andrew Hon, Project Manager Licensing Project Branch 11-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-328

Enclosure:

NRC Review of Report cc w/enclosure: Distribution via Listserv

OFFICE OF NUCLEAR REACTOR REGULATION REVIEW OF STEAM GENERATOR TUBE INSPECTION REPORT FOR CYCLE 19 SEQUOYAH NUCLEAR PLANT UNIT 2 TENNESSEE VALLEY AUTHORITY DOCKET NO. 50-328 By letters dated December 1, 2014 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML14342B004) and May 29, 2015 (ADAMS Accession No. ML15156A388, which includes ML15156A389}, Tennessee Valley Authority (the licensee) submitted information summarizing the results of the spring 2014 steam generator (SG) tube inspections performed at Sequoyah Nuclear Plant (Sequoyah}, Unit 2. These inspections were performed during refueling outage 19.

Sequoyah, Unit 2, has four Model 57 AG+ SGs installed in 2013 that were designed by Westinghouse and fabricated by Doosan Heavy Industries. Each SG contains 4,983 Alloy 690 tubes with a nominal outside diameter of 0.750 inches and nominal wall thickness of 0.043 inches. The tubes were hydraulically expanded for the full depth of the tubesheet.

The licensee provided the scope, extent, methods, and results of its SG tube inspections in the documents referenced above. In addition, the licensee described corrective actions (e.g., tube plugging) taken in response to the inspection findings.

After reviewing the information provided by the licensee, the staff has the following comments/observations:

• During the initial channel head visual inspection, discolored areas were noted, particularly in the SG 22 cold leg. The discoloration was evaluated and deemed not to affect SG function or integrity. The discoloration will be monitored in future inspections.

The cause of the discoloration was not determined. Possible explanations range from residue left during the electropolishing of the primary channel head bowls to refraction effects of the lights used during the examination of the primary channel head.

Based on a review of the information provided, the U.S. Nuclear Regulatory Commission staff concludes that the licensee provided the information required by the technical specifications. In addition, the staff concludes that there are no technical issues that warrant followup action at this time since the inspections appear to be consistent with the objective of detecting potential tube degradation, and the inspection results appear to be consistent with industry operating experience at similarly designed and operated units.

Enclosure

August 26, 2015 Mr. John T. Carlin Site Vice President Sequoyah Nuclear Plant Tennessee Valley Authority P.O. Box 2000, OPS 4A-SQN Soddy Daisy, TN 37384-2000

SUBJECT:

SEQUOYAH NUCLEAR PLANT, UNIT 2 - REVIEW OF THE STEAM GENERATOR TUBE INSERVICE INSPECTIONS FOR CYCLE 19 REFUELING OUTAGE IN 2014 (TAC NO. MF5422)

Dear Mr. Carlin:

By letters dated December 1, 2014 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML14342B004) and May 29, 2015 (ADAMS Accession No. ML15156A388, which includes ML15156A389), Tennessee Valley Authority (TVA) submitted information summarizing the results of the spring 2014 steam generator tube inspections performed at the Sequoyah Nuclear Plant (Sequoyah), Unit 2. These inspections were performed during refueling outage 19.

The U.S. Nuclear Regulatory Commission (NRC) staff has reviewed the information TVA provided and concludes it contains the information required by the Sequoyah, Unit 2, technical specifications and that no additional followup is required at this time. The NRC staff review of the steam generator portions of the report is enclosed.

If you have any questions, please contact me at (301) 415-8480 or Andrew.Hon@nrc.gov.

Sincerely, IRA/

Andrew Hon, Project Manager Licensing Project Branch 11-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-328

Enclosure:

NRC Review of Report cc w/enclosure: Distribution via Listserv DISTRIBUTION:

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DATE 819/15 8/19/15 7/29/15 8/26/15 8/26/15 OFFICIAL RECORD COPY