ML20246D527

Forwards Steam Generator Tubing Insp Results, Re Cycle 3 Insp.No Addl Tubes Plugged During 890227 Inservice Insp.Eddy Current,Row 2 Inner Radius U-bends in Steam Generators & Propagating Fatigue Cracks Also Examined

ML20246D527
Person / Time
Site:	Sequoyah
Issue date:	07/05/1989
From:	Michael Ray TENNESSEE VALLEY AUTHORITY
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20246D531	List: ML20246D527 ML20246D535
References
NUDOCS 8907110358
Download: ML20246D527 (2)

Text

. _ _ _ - _ _ _ _ _

~

TENNESSEE VALLEY AUTHORITY CH ATTANOOGA TENNESSEE 37401 5N 157B Lookout Place JUL 5 1989 i I

U.S. Nuclear Regulatory Commission i

ATIN: Document Control Desk Hashington, D.C. 20555 Gentlemen:

In the Matter of ) Docket No. 50-328 Tennessee Valley Authority SEQUOYAH NUCLEAR PLANT (SQN) UNIT 2 - INSERVICE INSPECTION (ISI) 0F UNIT 2 STEAM GENERATOR TUBES -

As required by SQN Unit 2 Technical Specification 4.4.5.5.b. enclosed are the results of the steam generator tube ISI completed for Unit 2 on February 27, 1989. No additional tubes were plugged during this inspection.

An ISI was performed on 204 tubes in steam generator 1 and 204 tubes in steam

. generator 4. The ISI result category was classified by TVA as C-1.

Independent of the ISI, TVA performed a self-imposed eddy current examination of all nonplugged, peripheral tubes in all four steam generators and a 20 percent random sample in steam generators 1 and 4. As a result of these examinations, antivibration bar wear was discovered in steam generators 1 and 3 (approximately 300 additional tubes were examined in both steam generators 1 and 3 to ensure bounding of the affected tubes). Twelve tubes in steam generator I and one tube in steam generator 3 were affected.

Additionally, all row 2, inner radius U-bends in all steam generators were examined with an optimized probe design (motorized rotating pancake coll), and 50 rotating pancake coil examinations were performed on steam generator 2 at the top of tubesheet expansion / transitions. TVA also performed examinations for the evaluation of SQN Unit 2 susceptibility to rapidly propagating fatigue cracks.

No commitments are contained in this submittal. Please direct questions concerning this issue to K. S. Whitaker at (615) 843-7748.

Very truly yours, TENNESSEE VALLEY AUTHORITY p

j G h' Manager,Nuc1[ar"[ Licensing and Regulatory Affairs Enclosure cc: See page 2 gp

(\

An Equal Opportunity Employer

~~

.i * .,

' 2-n . ~

U.S. Nuclear Regulatory Commission JUI. 5 8 89 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 1 Rockville, Maryland. 20852-Mr. B. A. Wilson, Assistant Director for Inspection Programs TVA Projects Division-  ;

U.S. Nuclear Regulatory Commission -

l Region II. .

101 Marietta Street, NW, Suite 2900 Atlanta,. Georgia 30323

.NRC Resident Inspector.-

.Sequoyah Nuclear Plant.

2600 Igou Ferry Road Soddy. Daisy, Tennessee 37379 1

_______