ML20245A395

Special Rept SR-88-004-01:on 880420,inservice Eddy Current Exam of Steam Generator Tubing Completed by Westinghouse.Two Tubes Exceeded Plugging Limit in Steam Generator A.All Discrepancies Resolved

ML20245A395
Person / Time
Site:	Waterford
Issue date:	04/10/1989
From:	Carns N LOUISIANA POWER & LIGHT CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
SR-88-004-01, SR-88-4-1, W3A89-0125, W3A89-125, NUDOCS 8904250181
Download: ML20245A395 (5)

Text

.

Ref:

10CFR50.36(c)(2)

LOUISIANA POWER & LIGHT / INTER-OFFICE CORRESPONDENCE maatain April'10, 1989 W3A89-6125 A4.05 QA U.S. Nuclear Regulatory Commission ATTENTION: Document Control Desk Washington, D.C.

20555

SUBJECT:

Waterford 3 SES Docket No. 50-382 License No. NPF-38 Reporting of Special Report Attached is Special Report Number SR-88-004-01 for Waterford Steam Electric Station Unit 3.

This Special Report is submitted per 10CFR50.36(c)(2) and Technical Specifications 4.4.4.5.b.

Very truly yours,

??d w N.S. Ca ns j

Plant Manager - Nuclear l

NSC/WEMark Attachment cc:

R.D. Martin, NRC Resident Inspectors Office, INPO Records Center (J.T. Wheelock), E.L. Blake, W.M. Stevenson, D.L. Wigginton

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8904250181 89041o

{DR ADOCK 05000382 PDC I

"AN EQUAL OPPORTUNITY EMPLOYER"

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SPECIAL REPORT SR-88-004-01 Steam Generator Eddy Current Examination (2nd Refueling)

INTRODUCTION Inservice eddy current examination of steam generator (SG) tubing was completed by Westinghouse Electric Corporation at Louisiana Power & Light's Waterford Steam Electric Station Unit 3 on April 20, 1988. This report is submitted in accordance with Technical Specification (TS) 4.4.4.5.b which requires the complete results of this inspection to be submitted in a Special Report pursuant to TS 6.9.2 within 12 months following the inspection. The examination included a random full length examination of approximately 3% of the tubes in each SG.

In addition, a sample of 300 tubes in each SG was examined to determine progression of tube wear at the diagonal strap region near the central cavity (batwing region).

The tube examinations were conducted in accordance with USNRC Regulatory Guide 1.83 Revision I and ASME Section XI using Westinghouse Procedure MRS 2.4.2 Gen-28 " Digital Multifrequency Eddy Current Inspection of Preservice and Inservice Heat Exchanger Tubing." The eddy current data was independently analyzed by two groups of certified Level IIA data analysts.

Descriptions of Examinations A random selection of 300 tubes in each steam generator (SG) was examined full length. This sample exceeds the minimum of 3% (281 tubes) of the tubes in each SG required to be examined by Technical Specification (TS) 4.4.4.5.

The random pattern included a sample of tubes from potential problem regions and tubes identified previously as being degraded.

i

In addition to the random sample, 165 tubes in SG 'A' and 164 tubes in SG 'B' were examined to determine progression of tube wear at the diagonal strap elevation outside of the p eventatively plugged region.

Two tubes exceeded the plugging limit in SG 'A' (Row 121 Line 45 and Row 42 Line 78). This required SG 'A' to be classified as category C-2 and the scope of the inspection was expanded to include an additional 600 tubes. Although Row 42 Line 78 was a tube in the " batwing" sample, the defect wac located at an elevation not associated with batwing wear and was therefore considered as requiring the additional inspections in accordance with TS 4.4.4.5.

In addition to the eddy current examination program, a visual inspection was performed to verify the location of plugs installed prior to this examination.

All tube plugs in both SGs were secure and in the correct locations.

The Eddy Current data was independently analyzed by two groups of certified Level IIA data analysts. All discrepancies between the primary and independent analysts were resolved on a daily basis.

mm__a____m..m_-_. -. _ _. _ - - - - -. _ - - - - - - _ - - - -

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1 Results of Examination 1

Steam Generator A The initial 3% (300 tubes) examination of SG 'A' detected the following:

P.ow Line

% Thru Wall Location Comments 15 25

<20% thru wall 7H 19 67

<20% thru wall BW5 75 105

<20% thru wall 5H 75 105

<20% thru wall 4H

+ 10.3" from 4H support 75 105

<20% thru wall 4H

+ 1.4" from 4H support 147 95 24% thru wall BW9 121 45 41% thru wall TSC Plugged The sample of 165 tubes examined to determine the progression of wear at the diagonal strap in tubes surrounding the preventively plugged region detected the following:

Row Line

% Thru Wall Location Comments

~5 71

<20% thru wall 4C 3

35 73

<20% thru wall BW1 37 75-

<20% thru wall BW9 41 75

<20% thru wall BW9 43 75

<20% thru wall BW9 38 76

<20% thru wall BW1 44 76

<20% thru wall BW5 50 86

<20% thru wall BW1 51 87

<20% thru wall BW9 49 89

<20% thru wall SC 41 99

<20% thru wall BW5 45 99

<20% thru wall BW1 38 100

<20% thru wall BW1 42 100

<20% thru wall BW1 37 101

<20% thru wall BW9 40 76 21% thru wall BW1 43 79 22% thru wall BW5 53 91 21% thru wall 7C 41 99 23% thru wall BW1 42 78 46% thru wall BW5 Plugged 49 83 31% thru wall BW9 Plugged.

Decision to plug was based on indeterminate wear rate The expanded program of 600 tubes detected the following:

Row Line

% Thru Wall Location Comments 96-76

<20% thru wall IC

~~

77 113

<20% thru wall 8H 77 113

<20% thru wall 6C 1

..a

~

Steam Generator B The initial 3% (300 tubes) examination of SG 'B' detected the following:

Row Line

% Thru Wall Location Comments 55-21

<20% thru wall IC 105 31

<20% thru wall 5H 137 57

<20% thru wall BW1 95 61-

<20% thru wall 4H 146 86

.<20% thru wall BW9 75 111

<20% thru wall 2H 2

114

<20% thru wall 3C 138 114 25% thru wall TSH 19 07 33% thru wall BW5 Plugged. Decision to plug was based upon indeterminate wear rate The sample of 164 tubes examined to determine the progression of wear at the diagonal strap in tubes surrounding the preventively plugged region detected the following:

Row Line

% Thru Wall Location Comments 51 85

<20% thru wall BW1 49 89

<20% thru wall BW9 47 93

<20% thru wall BW1 45 97

<20% thru wall BW1 39 101

<20% thru wall BW1 43 101

<20% thru wall BWS 35 73 23% thru wall 7H 33 103 31% thru wall BW1 Plugged. Decision to plug was based on indeterminate wear rate PLANT CONTACT I

J.E. Howard, Procurement / Programs Engineering Manager, 504/467-2791, ext. 327

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