ML20155K115
| ML20155K115 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 05/19/1986 |
| From: | Thoma J Office of Nuclear Reactor Regulation |
| To: | Stolz J Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8605270367 | |
| Download: ML20155K115 (55) | |
Text
'
May 19, 1986
. Docket 50-289 NOTE T0: John Stolz, Director PWR Project Directorate #6 Division of PWR Licensing-B FRCM:
John Thoma, Project Manager PWR Project Directorate #6 Division of PWR Licensirg-B
SUBJECT:
MEETING WITH GPUN CONCERNING STEfM GENERATOR REPAIR CRITERIA (TSCR 148)
On May 15, 1986 a eceting was held in Bethesda between GPUN and the NPC. The purpose of the meeting was to discuss steam generator repair criteria as described in the licensee's technical specification change request (TSCR) 148. Enclosure (1) contains a list of attendees. Enclosure (2) contains the licensee's presentation.
l At the close of the meeting NRC staff advised the licensee that they would get back to the licensee in a few days if additional data were necessary. The staff also announced that they intended to publish their SER by July 31, 1986.
9 Dr%1tet e,e 5, John Thoma, Project Manager PWR Project Directorate #6 Division of PWR Licensing-B i
a i
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l 8605270367 860519 PDR ADOCK O E89 g
P
o ENLCOSURE 1 LIST OF ATTENDEES NAME REPRESENTING D homa NRC/PBR-6 J.R.N. Rajan NRC/PWR-B/EB R. Weller NRC/PWR-B/PBD#6 C. McCracken NRC/PBDf6 D. Crutchfield NRC/NRR/PWR-B H.F. Conrad NRC/NRR/BWREB C.Y. Cheng NRC/PWR-B/EB K.R. Wichman NRC/PWR-8/EB R.B. Borsuin Babock & Wilcox-Bethesda L. Connor Doc-Search Associates A.K. Bhattacharyya Pennsylvania State /BRP.
S.D. Leshnoff GPUN T.L. Gerber Structural Integrity Assoc.
F.'S. Giacobbe GPUN 0.K. Croneberger GPUN W.0. Dornsife PA DER M.F. Wagner NRC/0 ELD W.A. Paulson NRC/NRR/PWR-B J. Herring Bechtel E. Murphy NRC P. Cortland NRC/0TE N.C. Kazanas GPUN M. Torborg GPUN J.S. Jandovitz GPUN S.M. Kowkabany GPUN C.
Dodd Oak Ridge National Lab i
-f
s TSCR 148 REVISED TMI-1 OTSG REPAIR LIMITS F. S. GIACOBBE INTRODUCTION STRUCTURAL BASIS S. D. LESHNOFF PREVIOUS WORK STRUCTURAL CAPABILITY W.R.T. FATIGUE STRUCTURAL CAPABILITY W.R.T. RUPTURE ASSESSMENT OF STRUCTURAL MARGIN T. L. GERBER INHERENT IN PROPOSED PLUGGING CRITERIA N. KAZANAS EDDY CURRENT TESTING REVIEW OF ECT RESULTS REVIEW OF 8 X 1 CAPABILITIES FUTURE EXAMINATION (6R)
GPU NUCLEAR CORPORATION MAY 15,1986 s
i---
-r.
_ _ _ _ \\
_ ~
GPUN PRESENTATION TO THE NRC MAY 15, 1986 F. S. GIACOBBE
o.
OTSG TUBE CONDITION History Cause:
Tube damage occurred in 1981 as a result of inadvertent intrusion of sodium thiosulfate into the reactor coolant system.
Location / :
Damage was initiated on the ID surface Type of the OTSG tubing primarily in the upper tube sheet (UTS) region.
Damage was in the form of IGA and circumferentially oriented stress assisted cracks.
Some damage occurred below the UTS.
_ = _.
...m._.
History ( Cont' d)
Mitigation:
Clean up RCS water via ion exchange Peroxide clean RCS surfaces to remove residual sulfur Implement controlled layup conditions Implement revised RCS chemistry specifications Raise minimum Lithium level to 1.0 ppm Limit sulfate / total sulfur to 100 pob~
Confirmation:
Extensive corrosion testing including long term corrosion test Leak rate testing Repeat eddy current tests
==
Conclusion:==
Additional sulfur related damage is not occurring nor expected to recur.
9 9
TYPE OF DAMAGE CIRCuMFERENTIAL INTERGRANULAR CRACKS INITIATING ON THE.ID SURFACE PENETRATING THROUGH WALL WAS THE PRIMARY FORM OF DAMAGE.
THE MAJORITY OF THIS DAMAGE WAS IN THE UTS REGION..
IGA WITH AND WITHOUT IGSAC WAS ALSO OBSERVED TO A LESSER EXTENT BELOW THE UTS.
~
SCOPE OF DAMAGE IGA SURFACE ETCHING
.001" DEEP
,/
s,, N
,/
'N
/
N, IGA ISLANDS IGSAC WITH IGA t
IGA /IGSAC I
IGSAC
/
WITHOUT IGA IGA WITH CRACKS
-x 'N
~ _...
=-
9 CONCLUSIONS Damage to OTSG tubing occurred in 1981 and represents
..a continuum of attack from minor IGA to throughwal'1 IGSAC.
No additional damage has occurred since 1981.
'1 No IGA without IGSAC was observed greater than 50%
throughwall.
IGA islands can have grain fallout which produces the appearance of pitting.
}
Damage is localized to region of attack.
Tube integrity away from attack is maintained.
4 IGA does exist below the threshold of detectability j
by eddy current.
IGA detection con be enhanced by mechanical. strain or i
grain dropout.
l
.i 6
\\
[
LOGIC 0FPRESENTATION STRUCTURALBASIS PREVIOUSWORK o
INITIATED (1982)TODEMONSTRATEMARGIN W,R.T.EDDYCURRENTDETECTIONCAPABILITY o
METHODOLOGYFOUNDACCEPTABLEINNUREG1019 o
PRESENTAPPLICATIONTODEMONSTRATE MARGINW.R.T.PROPOSEDOTSGREPAIRLIMITS RECENTWORK(TSCR148) o INITIATEDTODEMONSTRATECONFORMANCEWITH. REG.
GUIDE 1.121STRUCTURALCONSIDERATIONS 3380f(p.1)
PREVIOUSWORK STRUCTURALCAPABILITYW.R.T. FATIGUE o
DESIGNBASIS(ASMEIII-CRACKINITIATION) 0 INSERVICERULES(ASMEII-CRACKPROPAGATION)
STRUCTURAL CAPABILITY W.R.T. RUPTURE '
o ONETIMEONLY-MAINSTEAMLINEBREAKLOADING 3380f(p.2)
~
=
(-,
Y FATIGUE EVALUATI01;::?
I DESIGN BASIS - ASE III
~
.i PREDICTSLOCALFATIGUkDAMAGEDURINGpESIGNLIF 0
7 0
REPRESENTSCODIFIEDAPPROACH
~
ETHODOLOGY v
MATERIALS.
0 USESDESIGNBASISLOADINGS MAGNITUDE f.
FREQUENCY o
INADDITION,CONSIDERSFLOWINDUCEDVIBRATION L
3380f(p.3)
.. -. __.. ~. _. _.....,
..-.._, _ -... m s
/50'
. / 35'
't L
62 *t o
2 39:* 2
~snous 10*
4<
4 v
&. L5' O
3 20 o
33 do ni T t w.
C?IV'.75 CF P4turdu: An s g g,r g 3
FATIGUEEVALUATIONS(Continued)
INSERVICERULES-ASMEII 0
METHODOLOGYDEMONSTRATESMINIMUMDEFECTWHICH COULDPROPAGATEUNDERSERVICECONDITIONS 0
REPRESENTSCODIFIEDAPPROACH o
USESDESIGNBASISLOADING MAGNITUDE FREQUENCY o
CONSIDERSFLOWINDUCEDVIBRATION 0
CONSIDERSACTUALOPERATINGWATERCHEMISTRY LITERATURE TESTING e
u 3380f(P 4)
9 O
I60' li I
9 I
/~h S'
\\,
i
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e, 0
3 9:?'
2 rencvs W 90 a
S. U*N qx se:ry)
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0 45-4w Q
3 20 4
53 60 tn % ~ w.
C t i u '. T $ O f PA tV'00 : AN AWltj L.
-. = -
,(MAINSTEAMLINE)RUPTUREEVALUATION
~
O SOLIDMECHANICS:
FIRSTPRINCIPLESMETHODOLOGY EQUILIBRIUM 0FFORCESANDM0MENTS COMPATIBILITYOFSLOPESANDDISPLACEMENTS o
LOCUSOFPOINTSREPRESENTINGMAXIMUM STRUCTURALCAPABILITYASDETERMINED BYMATERIALFLOWSTRESS l
)
3380f(p.5)
i I
J 150' l
I e
t ns' =
\\
ns-g A
4.g vg d
J f ?* 2 "JMGU2 4
60*
7 L TC.%
SECTZi)
\\
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E
- 5*
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20 4
52 50 in % M w.
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w
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8 o
m O
m
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20 4
5a 50 10 % T* W.
3Howin G Peop04Gb PL UGGr^tG CR t r$R t A
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1
CONCLUSIONS o
TSCR148REPAIRLIMITSSEPARATEDFROMANALTYICALRESULTS BY10%ONNOMINALTHROUGHWALL(MINIMUM)
O MINIMUMMARGINDEFINEDAGAINSTMOSTLIMITING ANALYTICALRESULT l
3380f(p.6)
~
=.
=..
- =. - =. = =..
~
ASSESSMENT OF STRUCTURAL MARGIN INHERENT IN GPUN PROPOSED OTSG TUBE PLUGGING CRITERIA PRESENTATION T0:
1 NRC STAFF 4
MAY 15, 1986
[
T. L. GERBER STRUCTURAL INTEGRITY ASSOCIATES r
1
s OBJECTIVE:
EVALUATE THE STRUCTURAL MARGINS INHERENT IN GPUN PROPOSED OTSG TUBE PLUGGING CRITERIA (TSC 148, TDR 645)
MEANS:
UTILIZE STATE-0F-THE-ART DUCTILE FAILURE THE0 RIES CONSERVATIVELY ESTIMATE TUBE LOADS AND MATERIAL PROPERTIES EMPLOY REG GUIDE 1.121 RECOMMENDED SAFETY MARGINS 2
\\
FLAW ORIENTATIONS (ID FLAWS OF FINITE LENGTH AND DEPTH)
CIRCUMFERENTIAL AXIAL DUCTILE FAILURE THEORIES NET SECTION COLLAPSE TEARING INSTABILITY MATERIAL PROPERTIES FLOW STRESS FROM ASME CODE (3Sg)
LOWER B0UND STRESS-STRAIN CURVES REPRESENTATIVE J-R DATA EVALUATIONS BASED ON STATE-0F-THE-ART THE0RI.ES AND LOWER B0UND MATERIAL PROPERTIES d
3
..~.
~
NET SECTION COLLAPSE ASSUMES FAILURE OCCURES WHEN STRESS AT NET SECTION EQUALS FLOW STRESS (THE LIMIT LOAD)
ACCOUNTS FOR BENDING DUE TO NON-SYMMETRICAL CRACKING (CIRCUMFERENTIAL CRACKS)
ACCOUNTS FOR BULGING (AXIAL CRACKS)
BASIS FOR FLAW ACCEPTANCE CRITERIA 0F ASME CODE, SECTION XI l
USED EXTENSIVELY TO EVALUATE BWR PIPING FLAWS 4
~%-
.w e
a_-
_w
-. +
-m-
\\
e TEARING INSTABILITY BASED ON ELASTIC-PLASTIC FRACTURE MECHANICS THE0RY AND THE WORK 0F-PARIS ET AL.
ASSUMES FAILURE OCCURS WHEN APPLIED TEARING FORCE EXCEEDS THE TEARING RESISTANCE OF THE MATERIAL BASIS FOR RECOMMENDED EVALUATIONS OF LEAK-BEFORE-BREAK OF LWR PIPING (NUREG-1061, VOL. 3)
USED RECENTLY TO EVALUATE LOW TOUGHNESS WELD METAL CONCERNS IN BWR PIPING S
~
OTSG TUBE LOADS USED IN THESE EVALUATIONS NORMAL OPERATING LOAD STRESS AXIAL 1107 LBS 17.1 KSI PRESSURE 1350 PSI 12.1 KSI FAULTED AXIAL 3140 LBS 49.4 KSI PRESSURE 2672 PSI 23.9 KSI REG. GUIDE 1.121 RECOMMENDED MARGINS NORMAL OPERATING 3.0 FAULTED 1.428 EVALUATIONS BASED ON DESIGN LOADS AND REG. GUIDE 1.121 MARGINS 6
O e
e 9
h CIRCUMFERENTIAL CRACKS l
R1 n
~
L t
'T N
N j
N s
t 4
/
l 7
. ~.
s OTSG TUBE LOADS PSEUDO-ELASTIC & EUWmC-Pt.ASTIC 5.0 PSEUDO-ELASTIC, 5
3140 LB x 1.428 (SF) f P = EAp I
4.0-i 1107 LB x 3.0 (SF)
I 39.4 KSI e
l x.0649 lb2 q
0-42 _KSI _x. _0649 I__l__,_
j g
- " I' 2 KSI 0*
e j
'I 34'nAdo 13 2
t j-r y
', q; '
et 2.0 -
l
\\ 6000F cr-E d
/
2350F<r-e
/
1.0-j
- NSCC For A/T = 0.4, 2% OFFSET l002IN/INx650IN /
L/ CIRC = 1.0 0.0
,'/
0.0 0.4 0.8 1.2 1.6 2.0 2.4 2.8 tusE asetAcnar M ELASTICALLY CALCULATED AND EXPECTED OTSG AXIAL TUBE LOADS a
,_,,_p
8 a
TimF AXIAL LOADS
~
TUBE AXIAL LOADS ARE (PRIMARILY) DUE TO DISPLACEMENT (DIFFERENTIAL THERMAL EXPANSION)
ELASTICALLY CALCULATED LOADS WITH REG.' GUIDE 1.121 RECOMMENDED MARGINS EXCEED THE YIELD LOAD ACTUAL TUBE LOADS ARE LESS THAN THE YIELD LOAD TUBE LOAD WHICH IS ACCEPTABLE FOR 40% OF WALL, 0
360 CRACKS, USED IN THESE EVALUATIONS 1
f e
9
4 OTSG TUBE CIRC. CRACKS NSCC. EOUlVALENC'i TO 40% 360 DEG CPACK 1.0
'\\
O.9 3
UC 0.8 s
N
(
O.6 k
N N _.
N.
U*
\\
y%
N
)
N N
w 0.4 0.3 0.2 0.1 0.0 0.0 0.0 0.4 0.6 0.8 1.0 L/ CIRC.
O NSCC.42KSI a
TDR e645 x
J-T.42KSI T
NSCC*
(NO NEUTRAL AXIAL SHIFT) 42 KSI COMPARISON OF PROPOSED TUBE PLUGGING CRITERIA WITH FAILURE THEORIES FOR CIRCUMFERENTIAL DEFECTS, TUBE LOAD ADJUSTED TO REFLECT 40% OF WALL PLUGGING CRITERION 10
o CIRCUMFERENTIAL' CRACKS CONCLUSIONS PROPOSED TUBE PLUGGING CRITERIA MEET REG. GUIDE 1.121 RECOMMENDED MARGINS FOR ALL CRACK SIZES SHORT, DEEP CRACK (70% 0F WALL, 0.5 INCH LONG) 0 HAVE MORE MARGIN THAN 40% 0F WALL, 360 CRACKS LATERAL RESTRAINT (NEAR SUPPORTS) PROVIDES ADDITIONAL MARGINS 11
A4 - - -
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L-a - -
--ra+-,<m-,
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,ymmy.,.n_
w O
g 6
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AXIAL CRACKS I
d I
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1
+
12 1
i
OTSG TUBE AXlAL CRACKS 3 X NOPWAL OP. STPESS WAX.
1.0 0.9 g
0.8 0.7.
\\
0.6
\\
N 0.5 N
0.4 O.3 - -
0.2 --
0.1 0.0 0.0 0.4 0.8 1.2 1.6 2.0 2.4 CPACK LENGTH (IN)
D 36.2 KSI a
Tort
- 6+5 COMPARISON OF PROPOSED TUBE PLUGGING CRITERIA WITH FAILURE THEORIES FOR AXIAL CRACKS, TUBE STRESS 3 X OPERATING STRESS 1
1 1
13
s OTSG TIJBE AXIAL CRACKS 1.428 X FAULTED STPESS WAX.
1.0 0.9 0.8 0.7 Ji
- -N Q.6 -
w h+
0.5 -
Ji 0.4
-i O.3 0.2 0.1 0.0 0.0 0.4 0.8 1.2 1.6 2.0 2.4 CPACK LENGTH (lN)
O 34.1 KSI a
TDR =(,45 COMPARISON OF PROPOSED TUBE PLUGGING CRITERIA WITH FAILURE THEORIES FOR AXIAL CRACKS, TUBE STRESS 1.428 X FAULTED STRESS i
14
OTSG TUBE AXIAL CRACKS 2.27 X NORMAL OP.
1.148 X F AULTED 1.0 0.9 0.8
\\
0.7..
0.6
\\
N 0.5
\\
0.4 0.3 0.2 0.1 i
l 0.0 0.0 0.4 0.8 1.2 1.6 2.0 2.4 CRACK LENOTH (IN)
D NSCC.07.4 KSI a
TDR e645 x
J-T.27.4 KSI COMPARISON OF PROPOSED TUBE PLUGGING CRITERIA WITH FAILURE THEORIES FOR AXI AL CRACKS, TUBE STRESS 2i27XOPERATING STRESS, 1.15 X FAULTED STRESS 15
.___m..
m..
_. - m. _
>..____...___.___u.
-.c._____m s
10 O
e l-\\
a' E
N4 y
A
~
1 E
N+k= 4 r
s o UnoEFECTro
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- o 1/** Stof E
3 O If2* Slot 2
- a i I/2* stof I
f-saw I* stof i
Npradicted behavior, o o 1o 2c so 50 50 sb 70 to 90 100 1.6 in. defect (equation 5-5) maiuuuotcaAoiTion($ WALL)
RJRST PRESSURES FOR O.625 x 0.034 IN. ECN SLOTS l
10 O
' \\
-s
\\g
- . 7 x
s y
5 Y*
5
+
4
- o unoEFECTED N
E
_ o e.u..tt 3
E g
,5.,,,,3,ggg
\\,
_-i-B&W
\\
c predicted behavior, o 10 20 sc so 50 60 70 to 90 los 1.5 in. defect mzimum otGRADAtlos (5 WALL)
(equation 5-5)
SURST PRESSURES FOR 0.625 x 0.034 IN. ELLIPT *AL RASTAE BURST TEST RESULTS AND PREDICTIONS FOR TUBES WITH PART THROUGH-WALL DEFECTS 4
16
s 50 a
O 40 -
O m
E D
s b
+
a
- ~
n 4!
s N
- zIt 20 -
\\
o g
\\
H e.
\\
8 N
H O
D I
to -
0 0.4 0.8 1.2 1.4 2
2.4 2.8 IMmAL CRACK LINGTH (INCH) 0 0.050 inch wall thickness data [11]
0.050 inch wall thickness prediction 0.030 inch wall thickness data [12]
+
--- 0.030 inch wall thickness prediction BURST TEST RESULTS AND PREDICTIONS FOR TUBES WITH THROUGH-WALL DEFECTS 17
..~..
AXIAL CRACK CONCLUSIONS PROPOSED TUBE PLUGGING CRITERIA MEET REG. GUfDE 1.121 RECOMMENDED MARGINS FOR ALL CRACK SIZES EXCEPT SOME DEEP CRACKS ( h60% OF WALL)
BASED ON FAILURE THEORIES AND MIN. MATERIAL PROPERTIES, MARGINS ARE:
NORMAL OPERATING 2.27 FAULTED 1.15 TUBE BURST TEST DATA SHOW SIGNIFICANT MARGINS
~
OVER PREDICTIONS (BASED ON METHODS USED TO EVALUATE PROPOSED PLUGGING CRITERIA)
I i
18
... ~
i
~
OVERVIEW:
0TSG TUBE PLUGGING CRITERIA PROPOSED BY GPUN CONTAIN MARGINS TO FAILURE EQUAL TO OR GREATER THAN REG. GUIDE 1.121 RECOMMENDED MARGINS MARGINS INHERENT IN A0% OF WALL PLUGGING CRITERION POSSIBLE EXCEPTION TO THIS CONCLUSION IS DEEP, RELATIVELY SHORT, AXIAL CRACKS.
BURST TEST DATA SHOW THAT MARGIN INHERENT IN EVALUATION METHODS MAKES UP FOR THIS DISCREPANCY.
l 19
PURPOSE I.
REVIEW OF ECT RESULTS TO DETERMINE:
1.
IF CORROSION IS ACTIVE 2.
IF KNOWN INDICATIONS ARE PROPAGATING II.
REVIEW 0F 1982 1984. AND 1986 ECT RESULTS III.
REVIEW OF THE'8Xi ECT CAPABILITIES 1.
SENSITIVITY 2.
EXTENT OF COVERAGE IV.
FUTURE EXAMINATIONS REQUIREMENTS 1.
T.S. SAMPLES 2.
AUGMENTED EXAMS 1
e
l REVIEW OF 1982, 1984, 1986 EDDY CURRENT EXAMINATION RESULTS
~
I i
1982 1984 1986 6ENERATOR A
B A
B A
B l
~
NUMBER TUBES 15,530 15,530 14,615 6,500 1,500 1, 239 '
EXAMINED /
PERCENT 100%
100%
100%
42%
10%
8%
NUMBER TUBES 885 273 298 30 10 15 REMOVED FROM SERVICE NUMBER OF 13' 50*
266' 44' 170 22 DEGRADED IUBES NOTE:
EXAMINATIONS PERFORMED FOLLOWING KINETIC EXPANSION (1983) AND DETECTION ~0F LEAKAGE (JULY 1984) ARE NOT INCLUDED.
MANY INDICATIONS CONSERVATIVELY INCLUDED AS DEGitADED CONDITIONS IN 1982 AND 1984 HAVE BEEN DETERMINED TO BE NON-RELEVANT DURING SUBSEQUENT EXAMINATIONS.
ECT EVALUATIONS RESULTS OF 1984 INSPECTION DOCUMENTED IN TDR 652 CONCLUDED THAT N0 SIGNIFICANT TREND OF THROUGH WALL GROWTH WAS ESTABLISHED ECT DATA COMPARIS0N FROM 1982 TO 1984 SHOWS A DECREASE IN THROUGH WALL PENETRATION OF 6.9%
MAJORITY OF INDICATIONS FIRST IDENTIFIED IN 1984 WERE DETECTABLE IN 1982 AFTER REANALYSIS 1982 SIGNAL AMPLITUDE 3 WERE LESS THAN A 3:1 SIGNAL TO NOISE RATIO i
INDICATIONS WITH SIGNAL AMPLITUDES LESS THAN 3:1 WOULD BE OVERCALLED FOR THROUGH WALL DEPTH THE 1986 RESULTS N0 NEW CORR 0SION ISI SUBSET REVEALS NO PROPAGATION i
RAND 0M 31 SAMPLE INSPECTION REVEALS ONLY 1 TUBE FOR REMOVAL FROM SERVICE i
INSPECTIONS FROM HIGH DEFECT AREAS REVEALED SOME MINOR REFINEMENTS REQUIRED (13 TUBES REMOVED)
.~
CHARACTERIZATION OF 1982, 1984, 1986 EDDY CURRENT INDICATIONS *
+
c 0TS6 1982 1984 1986 INDICATION A
76% <2 v0LTS 75% <2 v0LTS 91% <2 VOLTS AMPLITUDE (VOLTAGE)
B 51% <2 v0LTS 471 <2 v0LTS 57% <2 VOLTS PERCENT A
50% >90% T.W.
22 >90% T.W.
1 TUBE
>901 T.W.
THROUGH WALL M I >40% T.W.
40% >40% T.W.
6 TUBES >40% T.W.
e i!
1 B
16% >90% T.W.
1% >90% T.W.
3 TUBES >901 T.W.
]
60% >40% T.W.
27% >40% T.W.
9 TUBES >40% T.W.
! CIRCuMFERENTIAL A
INDICATIONS RANGED INDICATIONS RANGED INDICATIONS RANGED
~
l EXTENT 1-8 COILS 1-3 COILS 1-2 COILS r
B INDICATIONS RANGED INDICATIONS RANGED INDICATIONS RANGED l
1-8 COILS 1-3 COILS 1-3 COILS i
NOTE: 1986 DATA DOES NOT INCLUDE INDICATIONS IN PREVIOUSLY DEGRADED TUBES.
i
's LOCATION OF 1982, 1984, 1986 EDDY CURRENT INDICATIONS 1982 1984 1986 RADIAL OUTER PERIPHERY OUTER PERIPHERY OUTER PERIPHERY AND i
DISTRIBUTION OF BOTH A & B 0F BOTH A & B ALONG LANE AREA DF BOTH A & B AXIAL MOST IN UTS MOST IN UTS MOST IN UTS AND DISTRIBUTION AND 16TH SPAN AND 16TH SPAN AND 16TH SPAN i
BOTH A & B BOTH A & B BOTH A & B
EFFECT OF SIGNAL TO NOISE ON ECT SIGNAL INTERPRETATION ECT INDICATIONS OF AMPLITUDES LESS THAN THREE TO ONE SIGNAL TO NOISE (S/N)
RATIOS RESULTS IN OVERCALLING THROUGH WALL (T/W) DEPTH METALLURGICAL ANALYSIS RESULTS REVEALS 1)
INDICATIONS WITH SIGNAL AMPLITUDE OF LESS THAN 3:1 S/N RATIO - MEAN OVERCALL OF 31%
2)
INDICATIONS SIGNAL AMPLITUDE EXCEEDING 1 VOLT (3:1 SIGNAL TO NOISE) - MEAN OVERCALL 0F 3.8% T.W.
s e
e b
GROWTH PROGRAM (INDICATION FIRST SEEN IN 1984 - REANALYSIS OF 1982 REVEALS PRESENCE)
CONCLUSIONS:
A)
MEAN AMPLITUDE + 1.0 VOLT INCREASE B)
THROUGH WALL
- 6.9%
C)
SUBSET OF NOMINAL 2:1 S/N REVEALS THROUGH WALL
- 4.3%
DEGRADED TUBES (HIGH AMPLITUDE INDICATIONS IN 1983 AND 1984)
~
i CONCLUSIONS:
A)'-
MEAN AMPLITUDE + 0.9 V0LTS INCREASE B)
THROUGH WALL
+ 2.9% INCREASE t
1986 ECT RESblTS TMI-1 INSPECTION TOTAL TUBES NO. OF TUBES N0. OF TUBES POPULATION INSPECTED INDICATIONS <50%
INDICATIONS &50Z*
AND >20%*
A B
TOTAL A
B TOTAL A
B TOTAL 4
ISI TUBES 266 44 310 170 22 192 0
2 2
(1984 INDICATIONS <40%)
0540 SD INDICATIONS 228 50 278 21 2
23 3
0 3
NOT CONFIRED BY 8X1 IN 1984 LANE / WEDGE REGION 414 473 887 2
2 4
1 7
8 HI DEFECT / PLUG AREAS 113 169 282 1
2 3
0 0
0 31 RANDOM SAMPLE 479 483
%2 1
3 4
1 0
.1 TOTAL 1500 1219 2719 5
9 14 10%
8%
9%
j
- CONFIRMED BY THE 8X1 EXAM.
STATISTICAL EVALUATION OF DEGRADED TUBES No INDS No INDS No INDS MEAN STD
% T.W.
% T.W.
% T.W.
CHANGE DEVIATION NUMBER INCREASED DECREASED UNCHANGED
% I.W.
% I.W.
OTSG INDICATIONS 84-86 84-86 84-86 84-86 84-86 A
139 33 96 10
-3.0 6.1 B
13 6
3 4
+2.2 4.1 BOTH 152 39 99 14
-2.6 6.1 AaB l
DETERMINATION OF CIRCUMFERENTIAL EXTENT THE 8X1 TECHNIQUE CAN MEASURE THE CIRCUMFERENTIAL EXTENT OF AN INDICATION.
CIRCUMFERENTIAL EXTENT IS NOT NECESSARILY THE LENGTH OF THE INDICATION.
THE DISPOSITION OF THE TUBE IS BASED.ON THE CIRCUMFERENTIAL EXTENT, NOT THE LENGTH.
THE DETERMINATION OF CIRCUMFERENTIAL EXTENT IS BASED UPON THE NUMBER OF COILS WHICH RESPOND WITH A GIVEN AMPLITUDE SIGNAL.
WHEN DETERMINING CIRCUMFERENTIAL EXTENT OF CONFIRMED INDICATIONS, COIL RESPONSES OF ANY AMPLITUDE GREATER THAN.15 VOLTS ARE EVALUATED.
THIS IS MORE CONSERVATIVE THAN THE.3 VOLT THRESHOLD USED TO ESTABLISH 360* COVERAGE.
AMPLITUDE OF 8X1 AssoLuTE (.187" COILS) 4.0
.187" 3.0 e
1
- "g.
Asuplitudes of EMI Bocches 4
Using Production ECT e
'o Calibration Techniques 3>
2.0 u
I
.100" s's
.060a 1.0
.15 l
I I
I 20 40 60 80 1 Through Well
4 8
- c 1*
P R.0 B E THRESH 0LD 0F DETECTION t,0 7 Coq Tube OD
.625
]
s Min. wall X (2)
.068 p
'N, l
,/
e#p TubeID
.557 8
e' s
u
's CircumfID 1.75 l
Coil dia.
.187 l
i 1 voit peak calibration i
I
.300 volt response l
1 50* coverage per coil a
5' overlap g
COILS MAXIMUM MINIMUM 1
< 40*
.194" Threshold of Detection 2
< 85*
.413" 5'
.024" 3
<130*
.632"
> 45'
.219" 4
<175*
.851"
> 90*
.438" j
5
< 220*
1.07"
>135'
.656" 8
<265*
1.29"
>180*
.875" 7
< 310*
1.51"
> 225*
1.09" 8
360*
1.75"
> 270*
1.31"
~
l MEASURED IGSAC LENGTH VERSUS NUMBER OF COILS (8x1 ABSOLUTE)
REFERENCE TDR 686 N.:
.e 5
2
@NO e
2, t,. v.
1 e
o,0 W&
m 8e U
E d' e
- E
!g I
1 2
3 4
5 6
7 8
i
- of Coils Detected by 8 I 1 Probe POSSIBLE FACTORS ASSOCIATED WITH %ASUREMENT ERROR I
1.
PRECISION OF METALLURGICAL % ASUREMENTS j
2.
ORIENTATION OF IGSAC, LENGTH IS NOT EQUAL TO CIRCUMFERENTIAL EXTENT 3.
VARIATIONS IN PROBE SPEED RESULTS IN j
1-2 COIL INDICATION BEING RECORDED AS 2-1 COIL INDICATIONS.
l NOTE:
THE INDICATIONS SHOWN TO BE UNDERCALLED ABOVE, ARE FROM A TUBE WITH MULTIPLE INDICATIONS AND WOULD HAVE l
BEEN COMBINED WITH ADJACENT INDICATIONS AND THE TUBE f
DISPOSITIONED. PROPERLY.
,,.,,.,-...._4-,a.-,
-... - - - - - ~, _,,
OUTAGE 6R SCOPE (AS CONTAINED IN TR-008)
INSPECTIONS CONSIDERED " TECH SPEC" EXAMINATIONS INSPECTION ECT TECHNIQUES /
POPULATION LENGTH OF INSPECTION COMMENTS DEGRADED TUBES ALL TUBES WITH INDICATIONS l' 20%
A).540" H.G.S.DIFULL T.W. AND % 50% T.W. FROM PREVIOUS LENGTH INSPECTIONS
- 8) 8Xi ABSOLUTE / AREA 0F
.540 INDICATIONS RAND 0M SAMPLE 3% OF ALL TUBES REMAINING A).540" H.G.S.D/ FULL IN SERVICE IN EACH OTSG LENGTH B) 8Xi ABSOLUTE / AREAS OF.540 INDICATIONS 1
l OUTAGE 6R SCOPE
?
(AS CONTAINED IN TR-008)
INSPECTIONS CONSIDERED " AUGMENTED" EXAMINATIONS INSPECTION ECT TECHNIQUES /
POPULATION LENGTH OF INSPECTION COMMENTS 1 - WEAR INSPECTIONS (A) ALL TUBES ADJACENT TO 10 SELECTED A).540" H.G.S.D/ FULL SAMETUBESEXAMINEDbuRING PLUGGED BUT NOT STABILIZED TUBES LENGTH OUTAGE SM (1986)
WITH DEFECTS IN THE 15TH. 10TH AND iST SPANS IN EACH OTSG B) 8X1 ABSOLUTE /AS NECESSARY TO FURTHER CHARACTERIZE.540" INDICATIONS (B) ALL TUBES ADJACENT TO 10 SELECTED SAME AS AB0VE SAME AS AB0VE PLUGGED BUT NOT STABILIZED TUBES j
IN THE PERIPHERY OF EACH OTSG i
(C) ALL TUBES ADJACENT TO 5 PLUGGED SAME AS AB0VE SAME AS AB0VE
)
TUBES WITH 3.0 VOLT INDICATIONS IN THE LOWER PART OF EACH OTSG 2 - HIGH DENSITY PLUGGING AREA j
50 TUBES IN.HIGH DENSITY A).540" H.G.S.D/ FULL SAME TUBES EXAMINED IN LENGTH OUTAGE SM (1986)
PLUGGING AREAS IN EACH OTSG i
)
B) 8X1 ABSOLUTE /AS l
NECESSARY TO CONFIRM
}
Cith TMnTPATTANQ
4 0UTAGE 6R SCOPE (AS CONTAINED IN TR-008)
INSPECTIONS CONSIDERED " AUGMENTED" EXAMINATIONS INSPECTION ECT TECHNIQUES /
POPULATION LENGTH OF INSPECTION COMMENTS 3 - TUBESHEET EXAMS TUBES WITH NEW INDICATIONS IN A) 8Xi ABSOLUTE /6" SAME TUBES EXAMINED IN THE 6" QUAL. LENGTH IN EACH QUALIFICATION OUTAGE SM IN ADDITION TO OTSG LENGTH ANY NEW INDICATIONS FOUND DURING SM THE STATUS OF THE FOLLOWING INSPECTION HAS NOT BEEN DETERMINED. E.G., MAY OR MAY NOT BE REPEATED DURING OUTAGE 6R 1 - 31 0F TUBES IN EACH OTSG A) 8X1 ABSOLUTE / TOP 0F 6" QUAL. LENGTH TO LOWER SURFACE OF UTS
... r FIGURE 3 TDR 442 Rev. 0 1-1 OTSfs Longitudinal Section
'l l
PRIMARY FACE b
UPPER j
TUBESHEET (UTS)
JP
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TUBE
/
'g SUPPORT PLATES me -
ist LOWER i.
TUBESHEET (LTS)
PRIMARY FACE l
l REACTOR BLOG. FLOOR g :
___-___,_....._.J.._.___..
. _.. _. -., _... _ _. -. _.. _.. ~... _... _.., _ _...
~~
,].
D m O n 66 l
MEETING
SUMMARY
DISTRIBUTION Licensee: GPU Nuclear Corporation
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Docket File' NRC PDR L PDR PBD-6 Rdg JStolz PM J
OELD EJordan i
BGrimes ACRS-10 NRC Participants JThoma JRojan RWeller i
CMcCracken i
DCrutchfield HConrad CYCheng KWichman MWagner WPaulson EMurphy PCortland 9
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