ML20079F575
| ML20079F575 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 09/30/1991 |
| From: | Joshua Wilson TENNESSEE VALLEY AUTHORITY |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9110080205 | |
| Download: ML20079F575 (17) | |
Text
,.
HA
.u
.t
.n.
=e a
Jaa L WAon oi.
,gi u vir s, 4
September 30, 1991 U.S. Nuclear Regulatory Commission ATTNt Document Control Desk Washington, D.C.
20555 Gentlemen:
In the Matter of
)
Docket No 50-328 Tennessee Valley Authority
)
SEQUOYAll NUCLEAR PLANT (SQN) UNIT 2 - IN-SERVICE INSPECTION (ISI) 0F UN!1 l
2 STEAM GENERATOR (S/G) TULES
Reference:
TVA letter to NRC dated October 22. 1990. "Sequoyah Nuclear Plant (SQN) - Unit 2 Steam Generator Tube Plugging" In accordance with the requirements of SQN Unit 2 Technical Specification
-(TS) Surveillance Requirement 4.4.5.5.b. enclosed are the results of the S/G tube ISI completed October 12. 1990.
An ISI was performed on tubes in each of the four S/Gs. The ISI results fulfill all the requirements of SQN TSs.
TVA performed self-imposed eddy current examinations such that the following total percentage of tubes were examined f ull length:
S/G 1 35 percent S/G 2 42 percent S/G 3 32 percent S/G 4 27 percent Also, a minimum of'20 percent of the tubes were examined by rotating pancal.e coil -(RPC) at the hot leg top of tubesheet (HTS) in each S/G.
Because of indications.being found in the initial 20 percent sample in S/G 4, 100 percent of the' unplugged tubes were subsequently examined at the !!TS.
All' Row 2 tube U-bends in each S/G were examined by RPC (Row 1 tubes have been preventively plugged).
PDR ADOCK 050003M
- $i m ee m es
,e,se l
. Od eda 1
6 S
2 U.F. Nuclear Regulatory Commission September 30, 1991 i
As a result of these exams, four tubes were plugged (two preventively) in S/G 1 1ecause of antivibration bar (AVB) weart four tubes were plugged (one preventively) because of AVB wear and two tubes were plugged because of cold leg thinning in S/G 2; one tub was plugged preventively in S/G 3
&c suse of cold leg thinningt and four tubes were plugged because of HTS
,. mary water stress corrosion cracking and one tube was plugged because of HTS outside diameter corrosion in S/G 4.
Additionally, one tube in each of S/Gs 1 and 4 was plugged and a cable damper was installed in the U-bend region because of NRC Bulletin 88-02, " Rapidly Propagating Fatigue Cracks in Steam Generator Tubes."
No connitments are contained in this submittal.
Please direct questions concerning this issue to W. C. Ludwig at (615) 843-7460.
Sincerely, i
f){AL b /VC.
L. Wilson Enclosure ec (Enclosure):
Mr. D. E. LaBarge, Project Manager U.S, Nuclear Regulatory Commission One White Flint, North 11555 Rockville Pike Rockville,: Ma ryland 20852 NRC Resident Inspector Sequoyah Nuclear Plant 2600 Igou Ferry Road Soddy Daisy Tennessee 37379 Mr. B. A. Wilson, Project Chief U.S. Nuclear Regulatory Commission Region II 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323 9
,,-!u
....y
.-m-
.,.~,,
.,,--w.m e.-,_.s,.__.
-w-O 4
s ENCLOSURE SEQUOYAll NUCLEAR PLANT UNIT 2 CYCLE 4 INSPECTION OCTOBER 1990 STEAM GENERATOR TUBING INSPECTION RESULTS (WO3 910926 001) e
a SEQUOYAH NUC1. EAR PLANT UNIT 2 CYC1.E 4 INSPECTION OCTOBER 1990 l
i i
- STEAM GENERATOR (S/G) TUBING INSPECTION RESULTS l
1 f
TABLE OF CONTENTS Table 1 - Inspection Summary Table 2 - S/G 1 Inspection Summary Table 3 - 5/G 2 Inspection Summary Table 4 - S/G 3 inspection Summary Table 5 - S/G 4 Inspection Summary j
Table 6 - Indications Table 1 - Plugged Tube Summary i
Table 8 - Nomenclature a
k r
t v
'.n-cyy-v, c, v w w F-
---aw,-v,wew-,...e
--,..-.,-,..-.~w
...,...r4,,,-
=----w m-ewn.
e-ew--e-,,--me
.- - - --. -.. = ---- - -
- =
w+-e s-
.._....__..___.___m.
t Table 1 SEQUOYAH NUCLEAR PIANT UNIT 2 CYCLE 4 INSPECTION OCTOBER 1990 INSPECTION SUFNARY l
S/G 1 S/G 2 S/G 3 S/G 4 Total tubes-examined 1702 1926 1673 3293 Tubes recording defects 2
5 0
5 (1 0% wall loss) 4 Tubes recording degradations 14 15 3
1 (120% to <40% wall loss)
Tubes recording irnperf ections 21 16 4
1
(<20% wall loss)
I l
l 1-l l.
.n..,.._.
. _,.. ~. _ _... _, _. -... - _ _.... ~. _.,.. _...,.. _ _. _ _ _. _ _ _ _ _. _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
Table 2 l
SEQUOYAll NUCLEAR PLANT UNIT 2 CYCLE 4 INSPECTION OCTOBER 1990 S/G 1 ljiSPECTION_ SDIMARY Examinations er of Tubes General def ect exams (Extent (Probe Type)]
Full length (bobbin coil) - tube end to tube end 1194 Partial length (bobbin coll) -
tubesheet to opposite tube end 4
Partial length (bobbin coil) - hot leg 75 Partial length (bebbin coil) - cold leg 25 Specialty exams (Extent (Probe Type)]
Ilot top of tubesheet (RPC) 685 Support plate intersection (RPC) 685 U-bend (RPC) 94 Total Number of Tubes Examined 1702 Indications Tubes recording defects 2
(1 0% wall loss) 4 Tt.bes recording degradations 14 (120% to <40". wall loss)
Tubes recording imperfections 21
(<20% wall loss)
Table 3 I
SEQUOYAH NUCLEAR PLANT UNIT 2 CYCLE 4 INSPECTION OCTOBER 1990 S/G 2 INSPECTION SUK'4ARY Examinations Number of Tubes General defect exams (Extent (Probe Type)]
Full length (bobbin coll) - tube end to tube enc 1435 Partial length (bobbin coll) -
tubesheet to opposite tube end 15 Partial length (bobbin coll) - U-bend and hot leg 6
Partial length (bobbin coll) - hot leg 30 Specielty exams [ Extent (Probe Type)}
Hot top of tubesheet (RPC) 690 Support plate intersection (RPC) 333 U-bend (RPC) 94 Total Number __of Tubes Examined 1926 Indications Tubes recording defects 5
(140% wall loss)
Tubes recording degradations 15 (1 0% to (40% wall loss) 2 Tubes recording imperfections 16
(<20% wall loss)
o 4
9 Table 4 l
SEQUOYAll NUCLEAR PLANT UNIT 2 CYCLE 4 INSPECTION OCTOBER 1990 S/G 3 INSPECTION SUW3ARY Examinations Number of Tubes General defect exams { Extent (Probe Type)]
Full length (bobbin coll) - tube end to tube end 1082 Full length (bobbin llL & CL / KPC U-bend) -
tube end to tube end (row 2) 4 Partial length (bobbin coil) -
tubesheet to opposite tube end 1
Partial length (bobbin coll) - cold leg 24 Partial length (bobbin coil) - hot leg 25 Specialty exams (Extent (Probe Type)}
Hot top of tubesheet (RPC) 760 Support plate intersection (RPC) 494 U-bend (RPC) 93 T0tal Number of Tubes F.xamined 1673 Indications Tubes recording defects O
r (140% wall loss)
Tubes recording degradations 3
(120% to (40% wall loss)
Tubes recording imperfections 4
(<20% wall loss)
_. _ _. =............., _... - -
.s
- Ft.#
tr.
x._
- f-j g, Ni Table 5 SEQUAYAH NUCLEAR Pl. ANT UNIT 2 CYCLE 4 INSPECTION OCTOBER 1990
- f. (g ?,
,y-h'D f S/G 4 INSPECTION SUjiFIARY 3r
_[
Examinsitons Number of Tebes Gerc al defect exams [Exte.nt (Probe Type)]
Full length (bobbin coil) - tube end to tube end 927 Partial length (bobbin coll) -
tubesheet to opposite tube end 6
Partial length (bobbin coil) - hot leg 25 Partial length (bobbin coil) ~ :old leg 25 Specialty exams (Extent (trobe Type)}
Hot tap of tubesheet (R10) 3293 Support plate int (rsect!on (A?C) 740 U-bend (RPf')
9' Total Number of rubes Examined 3193 e
Edic.itions Tube.4 recording defe r2 5
Q407 wall loss)
Tubes recording degredations 1
Q207. to <h0% iall loss)
Tubes rec v ing imperfectior:.
1
(<^
- tall loss)
t Table 6 SEQUOYAH NUCLEAR PLANT tl NIT 2 CYCLE 4 INSPECTION OCTOBER 1990-l
)
INDICATIONS S/G 1 Row Col Location
% Thru-Wall Characterization Resolution 20 33 H02 + 6.9 11 Manufacturing burnish None required 20
-58 H07 + 0.0 18 OD indication None required 24-42 C05 + 0.0 6
OD indication None required 25 10 CTS + 8.8 18 Manufacturing burnish None required 26 52 H02 + 35.4 17 Manufacturing burnish None required x31-79 C01 + 0.0 8
00 cold leg thinning None required 32 64'
.AV2 + 0.0 17 OD AVB wear None required 33_
44 AV2 + 0.5 12 OD AVB wear None req ~. fred 33 51 AV2 +-0.0 26 OD'AVB wear Note 1 33-15 6 AV3 + 0.0 33-OD AVB wear Note 1 33-57 AV2 + 0.0 29 OD AVB vear Note 1 AV3 + 0.0 19 OD AVB wear Nono required 33-58' AV2 + 0.0 35 00 AVB wear
^
~ 33 59 AV1 + 0.0 21 OD AVB wear Note 1
-AV3 + 0.0
- 22 OD AVB wear Note 1 34 44 AV2 + 0.0 42 00 AVB wear Tube plugged AV3 + 0.0 27 OD AVB weac Tube plugged 34 47 AV1 + 0.0 23 OD AVB wear Note 1 AV2 + 0.0 29 OD AVB wear Nota 1 AV3 + 0.0 31 OD AVB wear Note :
.34 48 AV 2 + 0 ".
39 10D AVD wear Tube plugged AV3 + 0 0 30 OD AVB wear Tube plugged 34 49 AV1 + 0.0 17 OD AVB wear Tube plugged AV2 + 0.0-37 OD AVB wear Tube plugged 34 AV3 + 0.0 33 OD AVB wear Tube plugged 50 AV2 + 1.0 42 OD AVB wear Tube plugged AV3 + 0.0 26 0D AVB wear Tube plugged 34 53 AV2 + 0.0-27 OD AVB wear Note 1 A'.'3 +10.0 2?
OD AVB wear Note 1 34 64~
H03 + 5.2 10
. Manufacturing burnish None required 34 71 H02 + 3.8 6
Manufseturing burnish None recuired 35_
61 H06 + 23.3 18 Manut..cturing burnish None required 35 75
.C04 + 17.8 11 Manufacturing burnish None required 36-62 H05 + 21.6 10 Manufacturing burnish None required 37 62-AV3 + 0.0 17 OD AVB wear None required 38 42
!!TS + - 39.9.
25 Manufacturing burnish Note !
HTS + 32.5
. 24 Manufacturing burnish Note.
l-4
-revv v+-
P
_T--,-_-e
+
u
~
Table 6 SEQUOYAH NUCLEAR PLANT UNIT 2 CYCLE 4 INSPECTION OCTOBER 1990 INDICATIONS S/G 1 (Continued)
Row Coi location
% Thru-Wall Characterization Resolution 40 26 H05 + 45.5 10 Manufacturing burnish None required 42 62 HTS + 13.2 11 Manufacturing burnish None required 42 66 CTS + 32.2 11 Manuf ar:turit.g 'surnish None required 42 67 C04 + 9.9 6
Manufacturing burnish None required 43 33 AV2 + 20.2 14 Manufacturing burnish None required 44 34 C01 + 0.0 25 OD cold leg t' inning Note 1 45 39 CO2 + 0.3 31 OD cold leg t...nning Note 1 Note L. Tube wiii be examined in future inspections.
LL1
/
(
x y,
4.
Table 6
.(Continued)
SEQUOYAH NUCLEAR PLANT UNIT 2 CYCLE 4 INSPECTION OCTOBER 1990 INDICATIONS S/G 2 Row -Col location
% Thru-Wall Characterization Resolution 6
93 col + 0.0 4
OD cold leg thinning None required 8
50 HTS + 48.2 8
Manufacturing burnish None required 12 2-H05 + 25.4 15 Manufacturing burnish None required 17 91 CTS + 16.5 9
Manufacturing burnish None required 20 24 H02 + 4.5 11 CD manufacturjng None required 29 30 C05 + 0.0 27 OD indication Note 1 i
29 32 AV4 + 0.0 17 OD AVB wear None required-
= 29-34 AV2 + 0.0-25 OD AVB wear Note 1 AV3 + 0.0-33' OD AVB wear Note 1 AV4 + 0.0-13 OD AVB wear None required 29 42 AVL + 0.0 11 OD AVB wear None required AV2 + 0.0 18 OD AVB wear None required AV3 + 0.0 24 OD AVB wear Note 1 AV4'+ 0.0 14 OD AVB wear None required 30 44-H04 + 2.7 19 Manufacturing burnish None required L31 13-C01 + 0.0 35 OD cold leg thinning Note 1 32 54.
AV3 + 0.0 24 OD AVB wear Note l' 32 55 AV1 + 0,0 15 OD AVB wear None required AV2 + 0.0 14 OD AV3 wear ikme required AV3 + 0.0 19 OD AVB wear None required 32 59
-AV1 v 0.0 16 OD AVB wear None required
~
AV2 + 0.0 33 OD AVB wear Note 1 AV3 + 0.0 27 OD AVB wear Note 1 32-79 COL + 0.0 22 OD cold leg thinning Note 1
.33 49-AV3 + 0.0 23 00-AVB wear' Note 1
'l AV4 + 0.0 18 OD AVB wear Tube plugged 33 57 AVL + 0.0 35 OD AVB wear Tube plugged AV2 + 0.0 41 OD AVB wear Tube plugged AV3 + 0.0 32 OD AVE wear Tube plugged 34 34 AV2'+ 0.0 38 OD AVB wear Tube plugged AV3 + 0.0 28 OD AVB wear Tube plugged 1
_34 62
-AV2 + 0.0 33 OD AVB wear Tube plugged AV3 + 0.0 41 OD AVB wear Tube plugged 34 64 AV2 + 0.0 16 OD AVB wear None required 34 77 C01 + 0.0 14 OD cold leg thinning None required i
l
Table 6 1
(Contjaued)
SEQUOYAH NUr'. EAR PLANT 'JNIT 2 CYCLE 4 INSPECTION OCTOBER 1990 INDICATIONS S/G 2 (Continued)
Row Col Location
'l Thru-Wall Characterization Resolution 35 18 C01 + 0.0 18 OD cold leg thinning None required CO2 + 0.0 28 OD cold leg thinning Note 1 38 46 AV3 + 0.0 11 OD AVB wear None required AV4 + 0.0 8
OD AVB wear None required 43 33 C01 + 0.0 24 OD cold leg thinning Note 1 43 34 C01
- 0.0 44 OD cold leg thinning Tube plugged 43 35 C01 + 0.0 50 OD cold leg ttinning Tube plugged 43 36 C01 + 3.0 25 OD cold leg tiinning Note 1 Note 1. Tube will be examined in futura inspectitas.
~ - -..
.t.
-Taote 6 (Continued)
SEQUOYAH NUCLEAR PLANT UNIT 2 CYCLE 4.IN5PECT10N OCTOBER 1990 INDICATIONS ~
S/G 3 j
1 Row. Col Location
% Thru-Wall Characterisation ReJolution 8
2 C01 + 0.0 22 OD cold leg thinning Note 1
-12
-28 C05 + 12.5 12 Manufacturing burnish None required
.32-16
'C01 + 0.0 17 0D cold leg thinning None required 34 -
44 -AV1 + 0.0 24 OD AVB wear Note 1~
-l AV2 + 0.0 29.
OD AVB wear Note 1 H
AV3 + 0.0 31 OD AVB wear Note 1
'34
-43 AV2 + 0.0 9
OD'AVB wear.
None required a
43 32 C01 + 0.0 38 OD cold leg thinning Tube plugged 46
- 52..1106 + 45.6 8
Manufacturing burnish None required Note 1. Tube will be examined in future insper* ions.
4 l-
i k i
Table 6-(Continued)
SEQUOY'H NUCLEAR Pl. ANT LNIT 2 CYCLE 4 INSPECTION OCTOBER 1990 INDICATIONS S/G 4 Row Col Location
% Thru-Wall Characterization Resolution j
17 20 CTS + 14.1 8
Manufacturing burnish None required j
27 64 HTS + 0.0 85 ID indication Tube plugged 38 22 CO2 + 0.0 28 OD cold leg thinning Note 1 40-41 HTS - 0.1 75 ID indication Tube plugged
'42 34 HTS - 0.1 46 ID indication rube plugged 43 30-HTS + 0.7 41 OD indication Tube plugged
)
44 43 HTS - 0.1 58 ID indication Tube plugged I
Note 1. Tube will be examined in future inspections.
1-l
- ~ ~. ~....
... -. ~
' Y. ?
- 9. :
b
+
_4 l
Table 7-l l
FEQUOYAH NUCLEAR PLANT UNIT 2 i
-CYCLE 4 INSPECTION-j OCTOBER 1990
)
1 n
PLUGGED TUBE
SUMMARY
S/G 1
-S/G 2 S/G 3 S/G 4:
u i
Previously Plugged Tubes 94 94 95 95 J
)
Tubes Plugged' Cycle 4 by Damage Mechanism i-i-
Primary Water Stress Corrosion 0
0 0
4 j
Cracking (PWSCC)
OD Corrosion HTS 0
0 0
1 Anti-Vibration Bar Wear (AVB) 4
'O O
. Cold Leg Thinning-0 2
1 0
i'
'NRC1 Bulletin 88-02 1
0 0
1 l
s Total ?ubes Plugged 99 100 96 101 i
PWSCC l-
'AVB Note::Thelfollowing-tubes were plugged due to NRC Bulletin 88-02:
i S/G Row Column
+'
1 10 60 4
9 60-
- Tubes plugged due to eddy current indications are identified in Table-6.
l 1
1 d.
4._
1
+,.
._ _.. ~. _ _. -
CL
- e?
o in Table 8 SEQUOYAH NUCLEAR PLANT UNIT 2 CYCLE 4 INSPECTION OCTOBER 1990 NOMENCLATURE Location Nomenclature for Sequoyah Nuclear-Plant
. Notation ~
-Description
'HTE~
' Tube end - hot leg.
HTS Top of tubesheet - hot leg
-H01 First support plate - hot leg H02 Second support plate - hot leg H03-Third support-plate - hot leg H04 Fourth support plate - hot leg H05_
Fifth suppcrt plate - hot leg H06
. Sixth support plate - hot' leg H07-Seventh support plate - hot leg AV1 First anti-vibration bar above H07 AV2 ~
Second anti-vibration bar above H07
- AV3,
.Second anti-vibration bar above C07 AV4 First anti-vibration bar above C07-C07 Seventh support plate - cold leg
~
~C06 Sixth support-plate - cold leg.
C05 Fifth support plate - cold leg-C04
-Fourth support plate - cold leg C03
. Third' support-plate - cold. leg-
-CO2 Second support plate
' cold leg C01 First support plate - cold leg-CIS.
Top of tubesheet - cold leg CTE Tube end - cold leg Indication locations are designated by an above listedLmajor location and numeric values.in inches above-cr below a major location.
Positive inches : indicate. _
positive elevation (exr.mple - HTS + 1.0 is one inch above the hot leg top of tubesheet).
l 1
I' I
.