ML17222A562
| ML17222A562 | |
| Person / Time | |
|---|---|
| Site: | Saint Lucie  |
| Issue date: | 10/31/1988 |
| From: | FLORIDA POWER & LIGHT CO. |
| To: | |
| Shared Package | |
| ML17222A563 | List: |
| References | |
| NUDOCS 8811010413 | |
| Download: ML17222A562 (12) | |
Text
Florida Power
& Light Company St. Lucie Unit f2 Nuclear, Plant Special Report For DDY CURRENT EXAMINATIONOF STEAM GENERATOR TUBING DURING OCTOBER, 1987 Nuclear Energy Services Materials, Codes and Inspections Department Juno Beach, Florida 33408 SSi10104i3 8S1024 PDR ADOCK 05000389 9
I I
1 5(,,
Introduction The Nuclear Energy
- Services, Materials, Codes
& Inspection Department, conducted an inservice eddy current examination of the Florida Power
& Light St. Lucie Unit g2 Steam Generator Tubing in
- October, 1987.
The extent of this examination included 1004 of non-plugged hot leg and cold leg tubes in accordance with plant technical specifications using multi-frequency eddy current equipment and differential bobbin coil test probes.
The eddy current data was subjected to two independent analyses using certified data analysts from Combustion Engineering, NDE Technology and
- Zetec, Inc.
Discrepancies in the independent analyses were resolved by Level III individuals from the respective agencies.
St.
Lucie Unit g2 contains two Combustion Engineering series 67 recirculating steam generators identified as PSL-2A and PSL-2B.
Each steam generator contains approximately 8,411 u-bend tubes made of inconel 600.
A baseline eddy current examination was performed in
- July, 1982 and the first inservice eddy current examination was performed in October, 1984.
An unscheduled inservice eddy current examination was last performed in March,
- 1985, due to primary to secondary tube leakage which was identified and attributed to flow; induced vibrational wear at the diagonal and vertical support
- straps, referred to as batwings (Figures 1 and 2).
To obtain wear progression
- data, 29 tubes which were plugged in March, 1985 were de-plugged in April, 1986 and examined using a
standard bobbin coil and a segmented bobbin coil probe.
The segmented bobbin coil probe provides wear data at both sides of the tube in contact with the batwing.
The results of this wear progression analyses is presented in Combustion Engineering report CEN-328 dated
- May, 1986.
Application of
'he wear progression model and conservative management practice during the
- October, 1987 outage resulted in "preventive maintenance plugging" of six (6) additional tubes in PSL-2A and two (2) additional tubes in PSL-2B.
Table 1
provides a
summary by steam generator of tubes
- examined, indications of tube wall penetration and tubes plugged.
Table 2 provides a listing of tubes plugged as a result of the
- October, 1987 examination and application of wear progression models.
Refer to Figure 1
as a
key to location codes.
A total of 8 tubes were plugged in the PSL-2A generator and 10 tubes were plugged in the PSL-2B generator.
Seven (7) tubes in PSL-2A were plugged as a result of wear at batwing or vertical support straps.
One (1) tube was plugged as a result of wear from a
foreign object; identified by visual examination to be a length of weld wire at the periphery of the tube bundle.
Ten (10) tubes were plugged in PSL-2B as a
result of wear at batwing or vertical support straps.
Table 3 provides a listing of all indications of tube wall penetration by location for each steam generator.
E I'
t, l
A r.
A number of tubes had indications located at the batwing areas which represent the initiation of tube wall damage from vibration as discussed above.
- However, the wear at these areas has not advanced to the point which will produce a
measurable result in terms of wall penetration.
Therefore, these indications are identified in the eddy current database and the affected tubes will be monitored during subsequent examinations or otherwise dispositioned.
PSL-2A PSL-28 V2 V4 vl~
~v5 DH- (Top)
(Bottom) 09H OOH-07H 06H 05H 04H 03H 02H OIH TSH TEH f li I!II I f
I
- (Top)
- (8ot tom) 09C 38.25" 08C 38.25" 070 37.5" 06C 35.0e 050 32.0" 04C 37.5w 030
- 35. 0" 020 32.0" OIC 28.0" TSC.
- 21. 5 TEC INLET OUTLET
'T.
LUCIK II le Ct'atea
~ Kiev.
1 to 7
Drilled Supporte
~ Elev.
8
& 9 STEAK GENERATOR ARRANGEMENT Figure 1
I
HEI l gglP DH-(top)
DH (bottom) gyps
~ ~>+
~APE BEND RFG!ON TVBE, 5UPPORT5 PLANT ST.
LUClK UNlT 2 Figure 2
TABLE 1 St. Lucie Unit 2 Summa of Inservice Edd Current Examination Results for October 1987 PSL-2A PSL-2B TOTAL TUBES EXAMINED Indications of Wall Penetration Less than 204 20 to 394 40 to 1004 Total 337 27 2
366 IND 186 16 9
211 Tubes Plugged based on Wear Progression Analysis and Management Conservatism Tubes Plugged Which Exceeded Plugging Limits Total Tubes Plugged 10 Total Tubes Plugged To Date 208 155
TABLE 2 St. Lucie Unit 2 Steam Generator Tubes Plu ed Durin the October 1987 Outa e Line Row Steam Generator A
Indication Location 56 59 82 92 92 94 98 130 94 133 52 42 44 40 38 116 40 40 33 37 36 34 35 33 V4 DH DC DH DH DH DC TSH + 11.3 Line Rov Steam Generator B
Indication Location 25 38 69 75 80 87 88 100 100 111 89 96 133 41 48 49 46 36 92 93 43 51 62 45 53 33 47 47 28 42 53 V2 V2 V4 V1 V3 DH V3 V3 DC V2 V2
St. Lucie Unit 2 Examination ram October 1987 Steam Generator PSL-2A List of all Tubes with Flaws Line Row Indication 1
Location 27 33 48 52 56 57 58 59 61 64 64 73 81 82 87 91 92 92 94 96 96 98 98 108 117 127 129 130 93 105 126 84 94 95 132 133 83 94 134 47 47 52 69 109 42 44 40 40 50 38 138 96 113 53 87 116 33 31 27 36 25 40 32 28 40 20 29 21 25 20 33 24 34 37 36 34 26 30 35 22 27 22 22 28 33 V4 +
V2 +
DH +
V3 +
V4 +
V4 +
V2 DH +
DH +
V3 +
V2 +
DH +
V3 +
V3
+-
DC +
5C +
TSC +
DH +
DH +
DH +
V3 V3 DC +
DH +
V2 +
5H +
V3 +
V3 +
TSH +
1.0 0.2 0.9 0.2 0.1 0.9 0.8 0.0 0.0 0.9 1.0 0.0 0.9 0.8 0.0 8.9 4.0 0.0 0.0 0.0 0.7 0.8 0.0 0.0 0.7 29.7 0.8 0.7 11.3
TABLE 3 St. Lucie Unit 2 Examination Pr ram October 1987 Steam Generator PSL-2B List of all Tubes with Flaws Line Row Indication Location 24 25 34 38 68 69 75 76 78 79 79 80 83 87 88 88 97 99 100 100 111 122 123 134 96 89 96 96 32 133 41 112 50 47 49 48 89 49 46 56 97 35 36 92 93 94 97 104 30 43 26 51 62 22 45 53 36 21 21 25 33 35 47 47 39 26 28 28 42 53 21 23 20 8H V2 V2 +
V2 V4 DH +
V1 +
V3 7C +
DC +
DH +
DC +
DH +
V3 V3 V3 +
V3 +
TSH +
DC +
DC +
V2 V2 +
V2 V3 +
V1 +
1.0 0.9 0.5 0 '0.9 0.0 0 '
0.9 0 '0.0 0.0 0.0 0.0 0.7 0 '
0 ~ 0 0.8 20.8 0.0 0.0 0.9 0.6 1.1 0.7 0.5