ML15092A173

Request for Additional Information Related to Spring 2014 Steam Generator Inspections Report Review

ML15092A173
Person / Time
Site:	Sequoyah
Issue date:	04/02/2015
From:	Andrew Hon Plant Licensing Branch II
To:	James Shea Tennessee Valley Authority
Andy Hon, NRR/DORL/LPLII-2
References
TAC MF5422
Download: ML15092A173 (2)

Text

From: Hon, Andrew Sent: Thursday, April 02, 2015 8:42 AM To: Shea, Joseph W Qwshea@tva.gov)

Cc: Helton, Shana; Hess, Thomas A (tahess@tva.gov); Johnson, Andrew

Subject:

SEQUOYAH NUCLEAR STATION, UNIT 2 - REQUEST FOR ADDITIONAL INFORMATION RELATED TO SPRING 2014 STEAM GENERATOR INSPECTIONS REPORT REVIEW (TAC NO. MF5422)

Follow Up Flag: Follow up Flag Status: Flagged ADAMSAccessionNumber: ML15092A173 Mr. Joseph W. Shea Vice President, Nuclear Licensing Tennessee Valley Authority 6A Lookout Place 1101 Market Street Chattanooga, TN 37 402-2801

SUBJECT:

SEQUOYAH NUCLEAR PLANT, UNITS 1 AND 2,- REQUEST FOR ADDITIONAL INFORMATION RELATED TO THE SPRING 2014 STEAM GENERATOR TUBE INSPECTIONS (TAC NO.

MF5422)

Dear Mr. Shea:

In a letter dated December 1, 2014, (Agencywide Documents Access and Management System (ADAMS)

Accession Nos. ML14342B004), Tennessee Valley Authority (TVA or the licensee) submitted information summarizing the results of the spring 2014 steam generator tube inspections performed at Sequoyah Nuclear Plant, Unit 2. These inspections were performed during refueling outage 19.

The U.S. Nuclear Regulatory Commission (NRC) staff is reviewing your submittal and has determined that additional information is required to complete the review. The specific information requested is addressed below. The proposed questions were discussed by telephone with your staff on April 1, 2015. Your staff confirmed that these questions did not include proprietary or security-related information and agreed to provide a response in 60 days from this request for additional information (RAI), due to upcoming refueling outage.

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The NRC staff considers that timely responses to RAls help ensure sufficient time is available for staff review and contribute toward the NRC's goal of efficient and effective use of staff resources. If circumstances result in the need to revise the agreed upon response date, please contact me at (301) 415-8480 or via e-mail Andrew.Hon@nrc.gov.

Sincerely, RIA Andrew Hon, Project Manager Plant Licensing Branch 11-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-327 and 50-328 Accession No. ML15092A173 REQUEST FOR ADDITIONAL INFORMATION SPRING 2014 STEAM GENERATOR INSPECTIONS SEQUOYAH NUCLEAR PLANT, UNIT 2 DOCKET NO. 50-328 TAC NO. MF5422

1. General information concerning the design of your replacement steam generators (SGs) was provided in the submittal. In order for the staff to better understand the design of your replacement SGs, please provide the following information:

a. A tubesheet map depicting the row and column numbers

b. Tube pitch (e.g., triangular, 1.00-inch center-to-center)

c. Expansion method and extent (e.g., hydraulic expansion for the full length of the tubesheet)

d. Tube support plate and U-bend support material and design

e. Flow distribution baffle design, if applicable

f. Whether tubes were stress relieved after bending, and if so, the rows that were stress relieved

g. The smallest U-bend radius

h. Tubesheet thickness with and without clad

i. The naming convention for the U-bend support structures and a more detailed diagram (since it appears that there are various supports running between the vertical straps within the tube bundle)

2. Please discuss the results of the foreign object search and retrieval inspections.

3. Please clarify Table 2-1 since the "planned exams" and "tests acquired" columns do not match. Please confirm all tubes were inspected and analyzed full length with a bobbin coil. Please clarify the number of tubes inspected with an array probe in both the hot leg and cold leg in all four SGs.

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