ML20059N386
| ML20059N386 | |
| Person / Time | |
|---|---|
| Site: | Waterford  |
| Issue date: | 10/03/1990 |
| From: | Mcgaha J ENTERGY OPERATIONS, INC. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| W3A90-0414, W3A90-414, NUDOCS 9010120175 | |
| Download: ML20059N386 (8) | |
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t W3A90-0414 A4.05 QA October 3, 1990 I
- U.'S.' Nuclear. Regulatory Commission ~-
1 ATTENTION:-
Document Control Desk' Washington, D.C.
20555
SUBJECT:
Waterford 3 SES Docket No. 50-382 License No.-NPF-38 ReDortina of Soecial"ReDort:
Gentlemen:
' Attached is Special Report Number SR-89-003-01'for;Waterford Steam Electric Station Unit 3.-
This Special Report' revision is
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l submitted per Technical Specifications 4.4.4.5 and 6.9.2.-
i
.j very truly yours, i
y.
J.
. McGaha General Manager Plant Operations JRM/JEF:glp Attachment a
cc:
Messrs.'R.D. Martin J.T. Wheelock'- INPO Records Center.
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-E.L.
Blake t
W.M.
Stevenson i
D.L. Wigginton l'
NRC Resident Inspectors Office-i l-9010120175 501003 TE j
EDR ADOCK 05000302L
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-o SPECIAL REPORT.
SR-89-003-01' Stean Generator Eddy current Examination (3rd Refueling)
J INTRODUCTION In-service eddy current examination of Steam Generator (SG) tubing was conducted
'by Westinghouse Electric Corporation at Waterford Unit 3 on October 8, 1989.
This report is submitted.in accordance with Technical Specification (TS)~
4.4.4.5 which requires the complete results of this. inspection be submitted in a special report pursuant to TS. 6.9.2 within 12 months.following the inspection.
The examination included full length examination of 6;4% (600) of the tubes in SG #1..
In addition,.163 tubes in SG #1 and 162. tubes in SG #2 were examined to determine progression of tuba 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'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 level II A' data analysts.
RESULTS OF EXAMINATION STEAM GENERATOR #1 The random 6.4% examination in SG #1 resulted in 26 indications less than 20%,
7 indications equal to or greater than 20%~but'less than 40% and no indications-greater than 40% through wall..
The " batwing examination" resulted in 17 indications less than 20%, 11 indications equal to or greater than 20% but less than 40% and 1 indication greater than 40% through wall. Due to the one tube having a greater than 40%
through wall (44%) on SG #1, the tubes surrounding the preventively plugged
" Batwing region" of SG #2 were examined.
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'[In'additionto'theeddycurrentexaminationprogram,!avisualverificationwas:
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- perf$rmed!.to : verify the': location of plugs-installed prior to ^this examination.
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sr All tube' plugs in SG.#1 were secure:acd in"the correct 11ocations..
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The initialT624% (600) examination.ofSG.#2 detected lthefollowing:i
- ROW LINE
% THRU WALL
- LOCATION -
LCOMMENTS^..
49 1,
15
- 25.
-< 20-%
' ~ 6H !
- 70t 38
. 20 %
TSC:
'19 :
67
<=20 %
- bW5 1
L96-.
76
<-20,%;
.- 1 C -
Q 95
- 77
< 20 % -
.50 1
{;
54' 78?
,< 20 %-
4CI
'[
t 1461 80::
< 20 %
.BWis 82 86-L< 20 %:-
'BW9 4.r 80-88
< 20 %~
.8C
[
.104 88
< 20 %-
7H.
- 1 147 91-
< 20 %
.BW9
.4 84
~92
< 20 %.-
7C t
75 105
<'20 %-
-2H T
a 75-105
'< 20 %
3H qq 75 105~
< 20 %
.4H 3
75 105
< 20 %'
SH>
-46 106
<-20-%-
6C:
Lj 77 113
< 20 %
8H 77 113
-<.20 %
6C' 1
136 120
< 20 %
BW1
-t
.30 126
'< 20 %'
- TSC-t 67--
'133
< 20 %J
~TSC i
16 148
< 20 %
.}
l:
22 158
.< 20 %
- 5C -
n q
.158
< 20-%'
5H k
62' 1158'
< 20 %.-
20-37 33 22 %
-TSH.
d
.i t
s !
-V j
2 jC e
1
- R0W-LINE.
% THRU WALL LOCATION COMMENTS-125' 43' 39 %
BW8'
' PLUGGED 93 67 30 %^
7C 93
-93.
.N/A-BW9 PLUGGED DUE-TO-UNINTER-PRETABLE-PERMEABILITY
' INDICATION-AT
~BW9.-
95
.77' 25 %.
7C 104-l88-
~22 %
7H 147 95
-31:%
-BW9-
- PLUGGED' 46 148 30 % '
-6H The sample of 163 tubes examined to determine' the progression ofiwear atil the-diagonal strap in' tubes surrounding the preventively-plugged region. detected -
- the following:
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R0W LINE
% THRU WALL LOCATION-COMMENTS l
33 71
< 20 %
2C 35 71
<'20'%
'4C-37 75
.< 20 %
BW9 43 75-
< 20 %_
BW9-
-l 146 80
< 20 %
-BW1-i 47 83
< 20 %
~ BW9 -
50 86
< 20 %
BW1-49 89
< 20 %
SC-l 48 90
< 20 %'
BW1 l
47 93
< 20 %
-7H 1
42 98
< 20-%-
BW9 45 99
< 20 %
BW1~
47 99
< 20 %
BW9 l
42 100
< 20 %
BW1
-1 L
42 100
< 20 %
BW9 I
48 100
< 20 %
BW9 41 103
< 20 %
BW9 1
v 7'
i h
1 3
1
_.'W hh
p R0W LINE
%-THRU WALL-'
LOCATION' COMMENTS
-35
.73
.44 %
4 iBW1
-PLUGGED-
-36' 74 20 %-
BW99 44 76
-25 %
BW9 ;-
-PLUGGED-
.43 79 27 %-
'BW5 51 87 38 %
BW9 PLUGGED 53-91 27 %
-7C 43 97 28 %
BW9 PLUGGED.
41 99 34 %
BW5.
- PLUGGED, 4
38 100 27 %
BW1 PLUGGED 44' 100 20 %,
BW9 1
l 37 101 27 %
-BW9 PLUGGED
'l 36 102' 23 %-
.BW9 STEAM GENERATOR #2 The " batwing examination" resulted in-19 indications less than 20%, 8 indications j
equal to or greater than 20% but less than 40% and_no indications equal to or
-j greater than 40% through wall. Eleven. tubes outside of the batwing region which; t
contained some type of sonormality identified during previous refuelings were
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examined. There was-no expanded program in this generator.
i During' video scanning of SG #2, tuo tubes (row 33/line 73 and row 19/line 109) were discovered to be erroneously plugged on the hot 1eg side only.,These tubes were plugged during-Refuel 2 (RF2)-in place offtwo other tubes (row 33/line 103 and row'19/line 67) which were selected-to be plugged as a preven-l tive measure based on 31% and 33% through wall degradation respectively. The erroneously plugged tubes are mirror images of the tubes that had been selected for plugging.
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Further investigation revealed that the hot leg tube sheet was marked in error
-during RF2, This-taused a 180 degree offset in the. marking pattern and-resulted in plugging ine wrong tubes.
The marking equipment used during RF2' consisted of a television (TV) camera and ~ 1aser 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 l
tube plugging. A procedural inadequacy contributed to the event; specifically, the Westinghouse marking procedure identified a primary (TV/ laser) and alternate l
(eddy current probe) method. The~ primary method was~used during RF2; however, the eddy current probe method is the more accurate method for positive indexing of SG tubes. Use of the eddy current probe method would have precluded the l
improper marking of the SG tube sheet.
-Additionally, RF2 plug pattern verification techniques were questionable based j
on the fact that en adequate verification technique should have identified the error prior to commencing tube plugging.
Tube row 33/line 103, row 19/line 67, row 33/line 73, and row 19/line 109 have
'l been plugged on both the hot leg and cold leg sides. The Westinghouse tube l
markings procedure will be revised to designate che eddy current probe method as the primary method of tube. indexing at-Waterford 3.
The eddy current 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 q
l resulting from the verification technique review will.be in place prior to RF4. This event has been discussed with the individual responsible.for the' erroneous tube marking. The SG #1 tube sheet was examined during RF3 and showed that all tubes were correctly plugged.
l Because only two tubes were erroneously plugged, SG thermal performance was I
not affected. The two tubes that were selected for pluggiag were plugged as a preventive measure, even though tube degradation was below the plugging limit 4
(40% below nominal wall thickness). Therefore, this event did not threate.. the health and safety of the general public or plant personnel.
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f Theiconditions found in SG'#2 were as follows:
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ROW.
LINE STATUS-1 l'
33 103-31%' degradation-(RF2), plugge'dP I
h on cold leg side'only. = Hot leg ='
side plugged during Refuel 3'.
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33 73 Sound tube, plugged on hot leg side only (RF2).
Cold leg side, j
-plugged during Refuel-3;
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19 67
-33% degradation (RF2),-plugged:'
on cold-leg side ~only.
Hot leg.
. side plugged during Refues 3.' M i
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q 19 109 Sound tube, plugged on. hot l leg-side only~(RF2).
Cold =1~g sidef.
e plugged'during Refuel'3.
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.j The sample of 162 tubes examined +> determine the progression of wear at th'e_
l diagonal strap in tubes surrounding the preventively plugged region detected-
.J the following:
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4 ROW LINE
% THRU WALL LOCATION
- COMMENTS 1
.l i
'30 70
< 20 %
- 4C.
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34 72
< 20 %
BW1
-l 35 73
< 20 %
7H
.)
l-37-75
< 20 %
BW1' l
1 37 75
< 20 %
BW9 l
1 41 77.
.< 20 %-
BW1 45 77
< 20 %
BW1
(;
51 81
< 20 %
BW9 i
I 47 83
< 20 %
BW1 51-85
< 20 %
BW1 d
6 x
_e L.,.1 g..
ROW
- LINE '
% TIIRU WALL-LOCATION COMMENTS 50 86.
< 20.%
BW1 --
48.
c90
< 20 %'
-BW9.
49-91
< 20 %.
_BW1 S1
'91-
< 20 %
BW11 48
-92
< 20 %-
. BW1' 43 97
' < 20 %.
BW1.
i 47 97
< 20 %
BW1 1
39
'101-
< 20.%
BW1 42
'102 1<-.20 %
TSC 401 176 34~%~
- BW1 PL11GGED 42 74 21 %
BW1 47 81-
! 32' L BW9_
PLUGGED 49 89
'34 %
-BW9 PLUGGED-47 93
- 26.: % -
BW1 45
'97 21 %'
BW1 I
40 100 29-%
BW9 PLUGGED' 36 102
.28 %
BV9 PLUGGED I
a Eleven tubes outside of the batwing region which contained some type of j
imperfection identified in previous <refuelings were examined. This examination detected the following:
- l R0W LINE
% TIIRU WALL
' LOCATION COMMENTS 55 21
_< 20 %
1C' 105 31
< 2C %
Sll 22 44
< 20 %-
1 11 137 57
< 20 %
BW1 146 86
< 20 %
BW9 75 111.
< 20 %
.2C 2
114
< 20 %
3C
+F1.77" FROM SUPPORT 2
114
< 20 %
3C.
+8.02" FROM SUPPORT 95 61 22 %
4H l
138 114 25 %
TSil PLANT CONTACT J.E. Iloward, Procurement / Programs Engineering Manager, 504/464-3202.
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