ML19324C294

Special Rept:On 891026,inservice Insp of Tubing in Steam Generators Completed.Degradation Mechanisms of Steam Generator Tubing Falls In,Cold Leg Support Plate Thinning & Hot Leg Support Plate Damage

ML19324C294
Person / Time
Site:	Beaver Valley
Issue date:	11/08/1989
From:	Noonan T DUQUESNE LIGHT CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
ND3MNO:1986, NUDOCS 8911160091
Download: ML19324C294 (3)

Text

4'

.; f " l

~ '

'Af Telephone (41h 393 6000

ar-Shippingpo 1. PA 15077 0004 November 8, 1989 ND3MNO:1986 i

Beaver Valley Power Station, Unit-No. 1 Docket No. 50-334, License No. DPR-64 Suecial ReDort L

United States Nuclear Regulatory Commission ,

Document' Control. Desk l L Washington , DC 20555 4 l-  !

E i

U Gentlemen:

In accordance with Appendix A, Beaver Valley. Technical )

Specifications 4.4.5.5.a and 4 .4.5.5.c, " Steam Generators," the 1 following Special Report is submitted. This report is required to I I

document the results of the Inservice Inspection of the steam

~

generator tubes, performed during the Seventh Refueling Outage.

1 On October 26, 1989, the inservice inspection of the tubing in l steam generators RC-E-1A (S/G A), RC-E-1B (S/G B) and RC-E-1C (S/G  :

C) was completed. The number of tubes inspected is listed below.

During the first sample inspection of 3352 tubes in the "B" steam generator, 44 tubes were identified as defective. These results fall into a C-3 Category which requires reporting to the Nuclear' Regulatory . Commission prior to plant restart, in ,

I

'accordance with Technical Specification 4.4.5.5.c. This also '

requires inspection of 100% of the tubes in the other two steam generators. In order to investigate the cause of the degradatiori, we have conducted rotating eddy current examinations of 446 tube locations in the "B" steam generator and plan to examine 392

, locations in the other two steam generators. Additionally, L rotating ultrasonic examinations of several locations in the "A" steam generator were performed.

The degradation mechanisms of the steam generator tubing falls ,

in, Cold Leg Support Plate Thinning and Hot Leg Support Plate L damage. The Cold Leg Thinning results from a combination of tube vibration and chemical conditions in the steam generator secondary sides. The Hot Leg Support Plate damage indicates the presence of Intergranular Attack.

6911160091 891108 4$

V PDR ADOCK 05000334 S PDC '

t 0

r

- p

.,NovCmber 8, 1989-ND3MNO:1986 '

,Page 2 l

Boric acid additions are planned for the secondary sides of the steam generators to neutralize the concentration of chemicals

, which is believed responsible for the Cold Leg Thinning.

This report also documents the number of plug retainers installed and the number of plugs replaced with new pluge in each g

steam generator.

S/G A S/G B S/G C t

Number of tubes plugged as a result of 86 45 19 this inservice inspection Number of plug retainers installed in 12 N/A N/A Westinghouse plugs, heat no. NX-3962 Number of Babcock & Wilcox plugs 48 36 27 replaced During this inspection all Babcock & Wilcox plugs were replaced on the inlet side only, no outlet side p1 sty replacement was performed.

Very truly yours,

$fmd T. P. Joonan General Manager Nuclear Operations JT/cj Attachment l

y - -

t

'/h ,Novcab2r 8, 1989' ND3MNot1986

. . .'Page 3 cc: Mr. William T. Russell Regional Administrator United States Nuclear Regulatory Commission Region 1 475'Allendale Road King of Prussia, PA 19406 l C. A. Roteck, Ohio Edison ,

Mr.-Peter Tam, BVPS Licensing Project Manager t United States Nuclear. Regulatory Commission Washington, DC 20555 '

J. Beall, Nuclear Regulatory Commission, ,

BVPS Senior Resident Inspector Dave Amerine Centerior Energy 6200 Oak Tree Blvd. >

Independence, Ohio 44101 INPO Records Center Suite 1500 1100 Circle 75 Parkway Atlanta, GA 30339 G. E. Muckle, Factory Mutual Engineering, Pittsburgh Mr. J. N. Steinmetz, Operating Plant Projects Manager Mid Atlantic Area Westinghouse Electric Corporation Energy Syster.J Service Division Box 355 L

Pittsburgh, PA 15230 ,

American Nuclear Insurers c/o Dottie Sherman, ANI Library The Exchange Suite 245 270 Farmington Avanue Farmington, CT 06032 Mr. Richard Janati Department of Environmental Resources P. O. Box 2063 16th Floor, Fulton Building Harrisburg, PA 17120 Director, Safety Evaluation & Control Virginia Electric & Power Co.

P. O. Box 26666 One James River Plaza Richmond, VA 23261

. . . _ . . -- .. . . _ - _ - . _--_-_____. .. . .-- -.