ML20087D359

Forwards Sequoyah Nuclear Plant Unit 2,Cycle 6 Insp SG Tubing Insp Results

ML20087D359
Person / Time
Site:	Sequoyah
Issue date:	08/07/1995
From:	Shell R TENNESSEE VALLEY AUTHORITY
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20087D361	List: ML20087D359 ML20087D362
References
NUDOCS 9508100297
Download: ML20087D359 (2)

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tenressen vaney Aceiy post once so. 200a. soder-ca,sy lennessee 37379 August 7,1995 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555 -

Gentlemen:

In the Matter of ) Docket No. 50-328 Tennessee Valley Authority ) 3 SEQUOYAH NUCLEAR PLANT (SON) - UNIT 2 - INSERVICE INSPECTION (ISI) OF UNIT 2 STEAM GENERATOR (S/G) TUBES (UNIT 2 CYCLE 6 REFUELING OUTAGE)

As required by SON Technical Specification (TS) Surveillance Requirement (SR) 4.4.5.5.b, enclosed are the results of the S/G tube ISI completed for Unit 2 during the Unit 2 Cycle 6 refueling outage. The subject ISI was completed on August 25,1994.

The initial inspection samples in all four S/Gs were classified as Category C-2 (categories are defined in SR 4.4.5.2). In S/Gs 1 and 4, the first expansion sample was classified as Category C-1. In S/Gs 2 and 3, the first expansion sample was classified as Category C-2, while the second expansion sample was classified as Category C-1. The enclosed report summarizes service-induced wall-loss indications, sample classification, and S/G inspection scope for the SON Unit 2 Cycle 6 ISI.

TVA performed eddy current examinations such that the following total percentages of tubes were examined with bobbin coil probes fulllength, rotating princake coil (RPC) at the hot-leg top-of-tubesheet (HTS), and RPC on Rows 1 and 2 up to the U-bend:

EXAM TYPE EXTENT S/G 1 S/G 2 S/G 3 S/G 4

(%) (%) (%) (%)

Bobbin Coil F/L 100 100 100 100 RPC HTS 45 100 63 45 RPC Rows 1 & 2 U-bend 100 100 100 100

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l Page 2 August 7,1995 A small number of RPC examinations were performed at hot-leg dented tube support plate intersections. Row 1 hot-leg and cold-leg plugs (previously installed) were removed. U bend heat treatment was performed on Row 1 and 2 U-bend regions.

RPC examinations were performed on Row 1 and 2 U-bend regions and HTS regions prior to their return to service.

As a result of these examinations, the number of tubes plugged and the cumulative total tubes plugged are as follows:

S/G 1 S/G 2 S/G 3 S/G.4 Plugged Cycle 6 Refueling Outage 14 39 20 2 Cumulative Total Plugged 25 64 38 11 No commitments are contained in this submittal. Please direct questions concerning this issue to D. V. Goodin at (615) 843-7734. )

Sincerely,

' i

) R. H. Shell Manager SON Site Licensing Enclosure cc (Enclosure):

Mr. D. E. LaBarge, Project Manager Nuclear Regulatory Commission One White Flint, North 11555 Rockville Pike Rockville, Maryland 20852-2739 NRC Resident inspector Sequoyah Nuclear Plant 2600 Igou Ferry Road Soddy-Daisy, Tennessee 37379-3624 Regional Administrator U.S. Nuclear Regulatory Commission Region 11 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323-2711