ML20244C531
| ML20244C531 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 06/08/1989 |
| From: | Michael Ray TENNESSEE VALLEY AUTHORITY |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML20244C534 | List: |
| References | |
| NUDOCS 8906150008 | |
| Download: ML20244C531 (2) | |
Text
_
A. ;
p m, k TENNESSEE VALLEY AUTHORITY u
CH ATTANOOGA. TENNESSEE 37401 i
5N 1578 Lookout Place 1
JUN 081989 l
U.S. Nuclear Regulatory Commission j
ATTN: Document Control Desk Washington, D.C.
20555 Gentlemen:
In the Matter of
)
Docket No. 50-327 l
Tennessee Valley Authority SEQUOYAH NUCLEAR PLANT (SQN) UNIT 1 - INSERVICE INSPECTION (ISI) 0F UNIT 1 STEAM GENERATOR TUBES
Reference:
Letter from TVA to NRC dated. July 18, 1988, "Sequoyah Nuclear Plant (SQN) - Unit i Steam Generator Tube Plugging"-
As required by SQN Unit 1 Technical Specification 4.4.5.5.b, enclosed are the results of the steam generator tube ISI completed for Unit 1 on July 3,1988.
The referenced letter provided the tube plugging summary for this inspection.
An ISI was performed on 695 tubes'in steam generator 1 and 695 tubes in steam-generator 4.
None of the inspected tubes were determined.to be defective.
The inspection result category was classified by TVA as C-1.
An additional number of non-ISI examinations were performed, bringing the total' number of tubes examined in steam generators 1 and 4 to approximately 25 percent.
Independent of the ISI, TVA performed a self-imposed eddy current examination of all rows 1 and 2 tube U-bend regions in all four steam generators utilizing an optimized probe design (motorized rotating pancake coil probe).
These examinations were performed for the detection of defects in close. radius U-bends. Rotating pancake coil examinations were performed in both steam generators 2 and 3 at the top of the tubesheet expansion / transition region.
Fifty-seven such examinations were performed in steam generator 2, and 73 in steam generator 3; no imperfections were discovered.
The enclosure provides a listing of steam generator-tubes that have recently been plugged based on the results of examinations.
There were-50 Unit 1, row I tubes that were plugged because of imperfections greater than 40 percent of the tube wall thickness. An additional 12 tubes were deplugged and replugged with a permanently installed plug. Also, the steam generator 1, row 10, column 44 tube was stabilized and preventively plugged based on identification as being susceptible to rapidly propagating fatigue cracking.
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8906150008 890600 y1 PDR ADOCK 05000327 4
G PNU 1
- An Equal opportunity Employer
'a t U.S. Nuclear Regulatory Commission AN.08 m.9 l
No commitments are contained in this submittal.
Please direct questions l-concerning this issue to K.' S. Whitaker at (615) 843-7748.
l Very truly yours, TENNESSEE VALLEY AUTHORITY l
[
L Mana$.(
ger, Nuc etr Licensing and Regulatory Affairs cc (Enclosure):
Ms. S. C. Black, Assistant Director for Projects TVA Projects Division U.S. Nuclear Regulatory Commission One White Flint, North 11555 Rockville Pike Rockville, Maryland 20852 Mr. B. A. Wilson, Assistant Director l
for Inspection Programs TVA Projects Division l
U.S. Nuclear Regulatory Commission Region II 101 Marietta-Street, NH, Suite 2900 Atlanta, Georgia 30323 Sequoyah Resident Inspector Sequoyah Nuclear Plant 2600 Igou Ferry Road Soddy Daisy, Tennessee 37379 l
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