ML20087D359
| 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: |
| References | |
| NUDOCS 9508100297 | |
| Download: ML20087D359 (2) | |
Text
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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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U.S. Nuclear Regulatory Commission 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,
) R. H. Shell i
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