ML19325D979

Discusses Eddy Current Exam of Steam Generator Tubing on 891008.Two Tubes Discovered to Be Erroneously Plugged on Hot Leg Side Only.Caused by Personnel Error.Tube Marking Procedure Revised

ML19325D979
Person / Time
Site:	Waterford
Issue date:	10/23/1989
From:	Mcgaha J LOUISIANA POWER & LIGHT CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
SR-89-003-00, SR-89-3, W3A89-0196, W3A89-196, NUDOCS 8910300214
Download: ML19325D979 (4)

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r l l.ou POWER isi &AN A / .WATERFORD 3 SES

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1 U.S. Nuclear.Regulat'ory Commission

~ ATTENTION

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SUBJECT:

, Waterford 3.SES DocketlNo. 50-382-l~

License No'NPF-38

. Reporting'of Special Report [

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I ' Attached'Is Special Report Number SR-89-003-00 for Waterford: Steam

. .  : Electric Station Unit 3. This Special Report is' submitted per -

R -~10CFR50.36(c)(2))and: Technical' Specifications 4.4.4.5 and 6.9.2. I i

Very truly yours, l i

J . c aha ,

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, Plant Manager -' Nuclear .. :

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Attachment:

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,1 cc s ' . Messrs. R.D. Martin j J.T. Wheelock - INPO Records Center g

. E.L. Blake W.M. Stevenson  !

' I D.L. Wigginton NRC Resident Inspectors ',

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I 'L ' SPECIAL REPORT

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~ Steam Generator Eddy' Current Examination-(3rd. Refueling) 'f p" % ,

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_In-service / eddy current examination of the Steam Generator (SG). tubing'was.

! completed atIWaterford Steam Electric. Station Unit ~3'on October 8,;1989. This

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report is submitted :ba accordance with Technical . Specification ~ (TS) 4'.4.4.o.a -

,1 which requires. reporting.the number pf tubes plugged in,each SG within 15 days '

LM ' < of completin'g 'in-service irispection (ISI) of. SC tubes pursuant to.TS 6.9.2. l A -  !

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, sfollowup report will-be submitted in.accordancefwith-TS 4.4.4.5.b by October t t se  : 18,.1990-. '

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The total number of' tubes which have been plugged in each SG are shown below:  !

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i SG #1 SG #2 {-

l Mat.ufa'cturing/Preservice- 6 20 i I i Batwing (Preventive Plugging) 149' -149 i 4

First. Refueling 0 1 i f

Second Refueling 3 0*

' Third Refueling 10 9

.e TOTAL 168 179

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• This. number represents the number of completely plugged tubes. (See below). l;

'During' eddy current testing (ECT) of SG #2 on October 8,1989, two tubes (row e 33/line 73 and row 19/line 109) were discovered to be erroneously plugged on t the hot leg side only. These tubes were plugged during Refuel 2 (RF2) in place

'" I of two other tubes (row 33/line 103 and row 19/line 67) which were selected to be plugged as a preventive measure based on 31% and 33% through wall degradation t

respectively. The erroneously plugged tubes are mirror images of the tubes that had been selected for plugging. The conditions found in SG #2 on October 8 were as follows:

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b. Row Line- Status 33' ~103 31% degradation:(RF2),; plugged on cold h.y i leg side.only.-

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33. 73 Sound tube, plugged on hot : leg side. '

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g 19 67 33% degradation'(RF2),. plugged on'coli leg side only.

'19, 109' Sound tube, plugged on hot leg side-s ,

only.

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s The SG f1 tube sheet was examined during RF3:and showed that all tubes are correctly plugged.

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. Further investigation revealed that the hot leg tube ' sheet was marked An error

~during RF2. This error caused a 180 degree offset in the marking pattern and resulted in plugging the wrong tubes. The marking equipment used~during RF2

. consisted of a television (TV) camera and laser marking device. This equipment configuration can cause.the operator to misjudge directions and mark the wrong tube. -Personnel error has been determined to be the root cause of the improper tube. plugging. A procedural inadequacy contributed to the event; specifically, the Westinghouse marking procedure identified a primary (TV/ laser) and alternate (ECT probe) method. The primary method was used during RF2; however, the ECT probe method is the more accurate method for positive indexing of SG l tubes. Use of the ECT probe method would have precluded the improper marking l of the SG tube sheet.  !

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Additionally, RF2 plug pattern verification techniques were questionable based .l on the fact that an adequate verification technique should have identified the error prior to commencing tube plugging. l 4

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.y Tube row 33/line 103, row 19/line 67, row 33/line 73, and row 19/line 109 have- '

been plugged'on both the hot leg and cold leg sides, The Westinghouse: tube marking procedure will be revised to designate the ECT probe method as the p'rimary method of ' tube indexing at Waterford 3. The ECT probe method was used during RF3 testing / plugging evolutions. Current plug pattern verification.

techniques will be reviewed to ensure that adequate' controls are utilized in.

order to preclude future tube marking errors. Any enhancements resulting from the verification technique review will belin place prior to RF4, This~ event has been discussed with the individual responsible for the erroneous tube-marking.

J' Because only two tubes were erroneously plugged, SG thermal performance' was not affected. -The two tubes that were selected for plugging were plugged as a

_ preventive measure, even though tube degradation was below the plugging limit (40% below nominal wall thickness). Therefore, this event did not threaten the '

health and' safety of the general public or plant personnel.  ;

PLANT CONTACT 5 J.E. Howard, Procurement / Programs Engineering Manager, 504/464-3202 e

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