unit ga unit ga . name ~~~ gas p'e recip.name 'ecipient ...regula y information distributi...

REGULA Y INFORMATION DISTRIBUTI SYSTEM (RIDS)P

ACCESSION NBR:9909240231 DOC.DATE: 99/09/21 NOTARIZED: NO DOCKETFACIL:50-275 Diablo Canyon Nuclear Power Plant, Unit 1, Pacific Ga 05000275

,<'0-,323 Diablo Canyon Nuclear Power Plant, Unit 2, Pacific Ga 05000323RUTH ." NAME AUTHOR AFFILIATION"

WOMACK,L.F. , Pacific Gas &. Electric Co. ~~~ P'e pep:+wRECIP.NAME 'ECIPIENT AFFILIATION

Records Management Branch (Document Control Desk)

SUBJECT: Forwards W rept SG-99-01-004,"NDE Qualification of BobbinDetection &. +Point Detection/Sizing for Axial PWSCC atDented TSP Intersections" & evaluation with previous eddycurrent insp results, included, as recpxested on 990413.

DISTRIBUTION CODE: AOOID COPIES RECEIVED:LTR i ENCL i SIZE:TITLE: OR Submittal: General DistributionNOTES:

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INTERNAL: ACRSNRR/DSSA/SPLBNUDOCS-ABSTRACT

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Pacific Gas andElectric Company

September 21, 1999

PG&E Letter DCL-99-122

'awrence F. WormckVice PresidentNuclear Technical Services

Oiablo Canyon Power PlantP.O. Box 56Avila Beach, CA 93424

605.545.6000

U.S. Nuclear Regulatory CommissionATTN: Document Control DeskWashington, DC 20555-0001

Docket No. 50-275, OL-DPR-80Docket No. 50-323, OL-DPR-82 e

Diablo Canyon Units 1 and 2Bobbin Detection of Axial Prima Water Stress Corrosion Crackin PWSCC inSteam Generator Tubes at Dented Tube Su ort Plate Intersections

Dear Commissioners and Staff:

The NRC letter to PG&E dated March 12, 1998, issued Amendments Nos. 124 and122 for Diablo Canyon Power Plant (DCPP) Units 1 and 2, respectively. Theseamendments allow implementation of voltage-based alternate repair criteria foroutside diameter stress corrosion cracking indications at tube support plate (TSP)intersections. Section 3.1.2 of the NRC safety'evaluation approved the dentinspection program proposed by PG8 E and stated: "ifchanges in eddy currenttechnology indicate that the bobbin coil probe can be qualiTied to detect degradationin dent signals of a particular voltage range, NRC staff would like to have theopportunity to review the qualification data before PG&E implements. the technique."

In 1998, subsequent to the NRC safety evaluation, bobbin coil probe qualificationwas completed for detection of axial PWSCC in s 2 volt dent signals. Thequalification report documented in Westinghouse report SG-99-01-004, "NDEQualification of Bobbin Detection and+Point Detection/Sizing for Axial PWSCC atDented TSP Intersections," dated February 4, 1999, is included as Attachment 1.The report presents a summary of the qualification efforts performed for bobbin coildetection of axial PWSCC in c 2 volt dented TSP intersections, and for Plus Pointcoil detection and sizing of axial PWSCC at dented TSP intersections over all dentvoltages. Separate Westinghouse reports, WCAP 15128 (proprietary) and WCAP15129 (nonproprietary), "Depth-Based SG Tube Repair Criteria for Axial PWSCC atDented TSP Intersections," were prepared to present the results of the performancetest, which validated the bobbin and Plus Point coil techniques. These reports weresubmitted to the NRC by Tennessee Valley Authority, Docket Numbers 50-327 and50-328, letter dated August 16, 1999.

i'90924023i 99092iPDR .ADOCK 05000275P PDR

"I/

Document Control DI:September 21, 1999

Qgg Page2

Ph Letter DCL-99-122

In a telephone call with the NRC on April 13, 1999, to discuss PG8 E's plans toimplement the bobbin detection technique, the NRC requested t'o review thefollowing items prior to implementation: 1) the bobbin qualification data; 2) DCPPinspection results with respect to PWSCC at dented intersections; and 3) PG8 E's

'ssessmentfor using the bobbin technique.

This letter provides the information requested by the NRC. Attachment 1 isWestinghouse Report SG-99-01-004. Attachment 2 is PG8 E's evaluation for use ofthe bobbin probe for detection of PWSCC in s 2 volt dented intersections in theDCPP steam generators. Previous eddy current inspection results with respect toPWSCC at dented intersections are included in the evaluation. A 10 CFR 50.59evaluation was performed which concluded that the changes proposed to use thetechnique do not constitute an unreviewed safety question.

PGRE will not implement this technique until completion of the NRC review.

Sincerely,

Lawrence F. Womack

cc: Edgar Bailey, DHS w/o Attachment 1

Steven D. BloomEllis W. Merschoff w/o Attachment 1

David L. Proulx w/o Attachment 1

Diablo Distribution w/o Attachment 1

Attachments

GRC/A0485126

Attachment 1

G8 E Letter DCL-99-122

WESTINGHOUSE REPORT SG-99-01-004

NDE QUALIFICATIONOF BOBBIN DETECTION AND+POINTDETECTION/SIZING FOR AXIALPWSCC AT DENTED TSP INTERSECTIONS

V

P.

. rI

'

Attachment 2G8 E Letter DCL-99-122

EVALUATIONOF USE OF BOBBIN COIL TO DETECT PRIMARYWATERSTRESS CORROSION CRACKING IN 6 2 VOLT DENTS

This change proposes to allow use of EPRI Examination Technique SpecificationSheet (ETSS) 96012 bobbin techniques for detection of primary water stresscorrosion cracking (PWSCC) in < 2 volt dented intersections. Plus Point inspectionsof < 2 volt dented intersections would continue to be conducted when bobbinidentifies distorted support plate indications, in order to confirm and characterize thedegradation.

The current NRC approved dent inspection program (License Amendment 124/122)requires the following Plus Point inspections, on a steam generator (SG) basis:

> 5 VoltDent Ins ection Criteria

Unit 2: 100 percent of > 5 volts dents, on both hot and cold legs are required to beinspected.

Unit 1, described below:

~ Inspection criteria: 100 percent of > 5 volt hot leg dented intersections up to andincluding the highest tube support plate (TSP) elevation where PWSCC,circumferential indications, or axial outside diameter stress corrosion cracking(ODSCC) not detected by bobbin (AONDB) at > 5 volt dents have beenpreviously detected in that SG, plus 20 percent at each higher hot leg TSPelevation. The inspection will always include a 20 percent sample of > 5 voltdented intersections at each hot leg TSP elevation.

~ Expansion criteria: If PWSCC, circumferential indications, or AONDB at > 5 voltdents, are identified in any 20 percent sample, then in the affected SG, inspect100 percent of > 5 volt dented intersections at that TSP elevation. IfPWSCC,circumferential indications, or AONDB at > 5 volt dents are identified at 7H, thenthe 20 percent expansion will be applied to the cold leg (7C), and will continuedown to the lowest cold leg TSP elevation until a 20 percent sample is obtainedthat is free from PWSCC, circumferential indications, or AONDB at > 5 voltdents.

~ Note: For any 20 percent sample, a minimum of 50 > 5 volt dented intersectionsin that SG at that TSP elevation will be inspected. Ifthe > 5 volt dent populationis less than 50, all the > 5 volt dented intersections at that TSP elevation will beinspected.

~ \

'I 1f ~

Attachment 2G&E Letter DCL-99-122

I

2 to 5 Volt Dent Ins ection Criteria for Units 1 and 2:

~ Inspection Criteria: 100 percent of 2 to 5 volt dented intersections (specifically,> 2 volts and < 5 volts) up to and including the highest TSP elevation wherePWSCC, circumferential indications, or AONDB at 2 to 5 volt dentedintersections have been previously detected in that SG, plus 20 percent at thenext highest TSP elevation.

o Expansion Criteria: IfPWSCC, circumferential indications, or AONDB at 2 to 5volt dented intersections are identified in the 20 percent sample, then in theaffected SG, inspect 100 percent of the 2 to 5 volt dented intersections at thatTSP elevation, plus 20 percent at the next highest TSP elevation. This step-wiseexpansion will be continued down to the lowest cold leg TSP elevation until a 20percent sample is obtained that is free from PWSCC, circumferential indications,or-AONDB at 2 to 5 volt dented intersections.

< 2 VoltDent Ins ection Criteria for Units Sand 2:

The criteria is similar to the 2 to 5 volt dent inspection program.

Inspection of dented intersections using the Plus Point probe was initiated in Unit 1

seventh refueling outage (1R7) and has been used in five subsequent outages.Starting in Unit 2 seventh refueling outage (2R7), the dent inspection program wasexpanded to include dents < 2 volts (i.e., no lower voltage threshold). Approximately2,000 intersections with < 2 volt dents were inspected in 2R7 and approximately3,000 intersections with < 2 volt dents were inspected in each subsequent outage.The inspection criteria listed above was strictly adhered to in Unit 2 eighth refuelingoutage (2R8) and Unit 1 ninth refueling outage (1R9), when voltage-based alternaterepair criteria (ARC) was implemented. In 1R7, only dents > 2 volts were inspected.Because of the complexity in calling dents < 2 volts, low voltage dent populationscan fluctuate.

The number of PWSCC indications at dented TSP intersections detected by PlusPoint since 1R7 is summarized in Table 1. Table 2 provides a detailed listing of theindications in Unit 1 eighth refueling outage (1R8), 2R8, and 1R9.

216 single axial indications (SAI) have been detected in < 2 volt dents, of whichbobbin detected 89 SAls (bobbin calling criteria did not use ETSS 96012 analysistechniques). 35 single circumferential indications (SCI) have been detected in > 2volt dents. Since circumferential flaws initiate at intersections which have largerdent voltages, potential SCls will be detected by Plus. Point during the course of the> 2 volt dent inspection.

s l: ~

4'0 . 4 ~

Attachment 2PG8 E Letter DCL-99-122

Condition Monitonn 1R8 2R8 1R9

Eddy current inspection data for PWSCC at dented TSP intersections during 1R8,2R8, and 1R9, are compiled in Table 2. Plus Point profiles from 1R8, 2R8, and 1R9were adjusted using the procedure described in WCAP-15128, so that validatedPlus Point sizing results (maximum depth, average depth, length) can be compared.Table 2 lists the locations; orientation (SAI or SCI); dent voltage; bobbin result; PlusPoint voltage; and Plus Point maximum depth, average depth, and length/extent foreach SAI; of the PWSCC indications detected in these outages.

243 PWSCC SAls were detected in 1R8, 2R8, and 1R9. The sizes of the SAls werenot significant. Applying the deterministic condition monitoring (CM) methodology inWCAP-15128, none of the PWSCC SAls have leakage potential because all wereless than 98 percent maximum depth, after accounting for 19.2 percentnondestructive examination (NDE) uncertainty. Length and average depths werecompared against Figure 7-1 of WCAP-15128, which provides the end of cycle(EOC) 95 percent/95 percent structural limitcurve for partial depth axial PWSCC,accounting for uncertainty in NDE and material properties. All indications have largemargins against burst relative to 1.4 differential pressure (DP) steam line break(SLB). Therefore, all axial PWSCC passed CM requirements.

Assessment ofBobbin Detection ofPWSCC at < 2 Volt Dents 1R8 2R8 1R9

Bobbin had limited success in detection of PWSCC in < 2 volt dents, detecting 40out of 154 SAls in 1R8, 2R8, and 1R9. Based on Table 2, the structurally limitingSAls in < 2 volt dents that were not detected by bobbin are summarized in Table 3.

Using ETSS 96012 analysis techniques, it is likely that these limiting flaws wouldhave been detected by bobbin based on Level III qualified data analyst expertopinion. Nonetheless, if it is assumed that these flaws were not inspected nordetected by Plus Point, would not have been detected by bobbin and, therefore,would have been left in service, a theoretical deterministic operational assessmentcan be performed. The theoretical EOC depths and lengths are shown in Table 3under EOC columns, applying 95 percent cumulative growth rates per effective fullpower year (EFPY) for average depth and length (defined as 13.3 percent and 0.15inch, respectively, per WCAP-15128). The EFPY for Unit 1 cycle 9, Unit 1 cycle 10,and Unit 2 cycle 9 are 1.62, 1.51, and 1.46, respectively. Based on these EOClengths and average depths, Figure 7-1 of WCAP-15128 shows that the theoreticalEOC flaws have large structural margin against 1.4 DP SLB.

Assessment ofBobbin Detection ofPWSCC at < 2 VoltDents 1R9 Regnal sisusin ETSS 96012

To determine the potential impact of using ETSS 96012 bobbin analysis techniques,the 1R9 bobbin data for the < 2 volt dents that were inspected by Plus Point (over

0

~ f» ~

1a ~ 0 ~

~ Attachment 2PG8E Letter DCL 99 122

3000 intersections), were rereviewed by blind analysis, i.e., the Plus Point resultswere not known. In preparation for this blind analysis, four analysts (two

production'nd

two resolution analysts, representing primary and secondary) successfullycompleted an ETSS 96012 site specific performance demonstration test using thedata set employed in the performance test documented in WCAP-15128. Based onthe results of the bobbin reanalysis, the limiting 1R9 flaw listed in Table 3 wasdetectable by bobbin. The largest SAI in a < 2 volt dent that was undetected bybobbin was located in SG 11 R22C76 at 3H. This SAI had a maximum depth of 47percent, an average depth of 33 percent, and a length of 0.15 in. If it is assumedthat this flaw was not inspected by Plus Point, would not have been detected bybobbin using ETSS 96012 techniques, and therefore, would have been left inservice, a th'eoretical deterministic operational assessment indicates that theaverage depth and length at EOC could be 53 percent and 0.38 in, accounting forgrowth. Figure 7-1 of WCAP-1 5128 shows that this theoretical EOC flaw has largestructural margin against 1.4 DP SLB. The flaw could have a theoretical EOC 10maximum depth of 89.6 percent based on 95 percent cumulative growth rate of 15.5percent per EFPY (for maximum depth) and NDE uncertainty of 19.2 percent (formaximum depth). No SLB leakage would be expected from this flaw at EOCbecause flaws less than 98 percent deep are not expected to leak per WCAP-15128.

Based on the results of the reanalysis, a bobbin probability of detection (POD) curvewas generated using Plus Point maximum and average depths (adjusted to themean NDE uncertainty) as truth. Because the ETSS 96012 reanalysis data set didnot include several larger Plus Point voltage SAIs (not all data was reanalyzed dueto time constraints), and to provide statistical relevance at larger depths, the PODcurve assumed that several larger voltage SAls (> 0.6 volts by Plus Point) wouldhave been detected by bobbin based on the results of expert opinion. The basis forincluding > 0.6 volt indications in the POD curve is because all reanalyzed > 0.6 voltindications were detected by bobbin as part of the ETSS 96012 reanalysis. Theresulting POD curve was compared against the POD curve from the performancetest results documented in WCAP-15128. The curves yield similar results.Therefore, the WCAP POD curve may be applied at Diablo Canyon Power Plant(DCPP) Units 1 and 2. The WCAP POD curve shows that the 95 percent PODvalues for average depth and maximum depth are 35 percent and 45 percent,respectively. Projecting the 45 percent maximum depth to an EOC depth will notresult in exceeding 98 percent maximum depth, accounting for 95 percentcumulative distribution function (CDF) growth rate and NDE uncertainty, and aprojected cycle length up to 2.18 EFPY. Projecting the 35 percent average depth toan EOC depth will not result in exceeding the 95/95 structural limits for 1.4 DP SLBfor flaw lengths up to 1.0 in., accounting for 95 percent CDF growth rate and NDEuncertainty, and a projected cycle length up to 2.18 EFPY.

f t ~

t

~ Attachment 2PG8 E Letter DCL-99-122

Revised Ins ection Criteria

Based on application of ETSS 96012 bobbin detection criteria for axial PWSCC in~ 2 volt dented intersections, Plus Point inspection of < 2 volt dents is no longerrequired. Therefore, the revised eddy current inspection criteria that may beimplemented is as follows:

~ 100 percent bobbin coil inspection of all TSP intersections (no change)~ Plus Point coil inspection of all bobbin coil indications at dented TSP

intersections (no change)~ For Unit 2, Plus Point inspection of 100 percent of > 5 volt dents (no change)~ For Unit 1, Plus Point inspection of > 5 volt dents as described earlier (no

change)~ On a SG basis, Plus Point coil inspection of all TSP intersections having > 2 and

< 5 volt dents up to the highest TSP elevation where PWSCC, circumferentialindications, or AONDB has been detected, plus 20 percent of > 2 and < 5 voltdents at the next highest TSP.

Conclusion

This change proposes to allow use of EPRI ETSS 96012 bobbin techniques fordetection of PWSCC in < 2 volt dented intersections. Plus Point inspections of < 2volt dented intersections would continue to be conducted when bobbin identifiesdistorted support plate indications, in order to confirm and characterize thedegradation.

Westinghouse report SG-99-01-004 provides a detailed EPRI Appendix Hqualification package supporting the bobbin detection technique. The technique hasalso been validated based on'a performance test conducted in 1998. WCAP-15128provides the results of the performance test and resulting POD evaluation. Basedon a review of past inspection results at DCPP Units 1 and 2, the bobbin POD inWCAP-15128 is applicable to DCPP. The WCAP POD curve shows that the 95percent POD values for average depth and maximum depth are 35 percent and 45

'ercent,respectively. The POD will support future DCPP tube integrityassessments, accounting for PWSCC in < 2 volt dents.

Use of the bobbin detection technique should significantly reduce the number ofrequired Plus Point inspections, reducing time, cost, and radiation exposure toworkers.

References

1. PG8 E letter to the NRC dated January 30, 1998 (DCL-98-011)2. NRC letter to PG8 E dated March 12, 1998

~ ~—

Attachment 2PGRE Letter DCL-99-122

3. Westinghouse report SG-99-01-004, "NDE Qualification of Bobbin Detection and+Point Detection/Sizing for Axial PWSCC at Dented TSP Intersections," datedFebruary 4, 1999.

4. WCAP-15128, "Depth Based SG Tube Repair Criteria for Axial PWSCC atDented TSP Intersections," January 1999, Westinghouse proprietary.

5. WCAP-15129, "Depth Based SG Tube Repair Criteria for Axial PWSCC atDented TSP Intersections," January 1999, Westinghouse nonproprietary.

6. EPRI Examination Technique Specification Sheet (ETSS) 96012

1 Attachment 2PG&E Letter DCL-99-122

TABLE 1

PWSCC AT DENTED TSP INTERSECTIONS

Dentvoltage

1R7 2R7 1R8 2R8 1R9 Total

<2

2-5

34 SAI(34)30 SAI

28 SAI (15)

23 SAI,1 SCI

95 SAI (32)

38 SAI 6 SAI,1 SCI

17 SAI,1 SCI

114 SAI,3 SCI

12 SAI (1) 47 SAI (7) 216 SAI (89)

>5

Total

13 SAI,4 SCI77 SAI,4 SCI






Notes:1. SAI = single axial indication, SCI = single circumferential indication2. Numbers in parenthesis are number of SAI detected by bobbin in < 2 volt dents.3. In 1R9, 33 SAI were left in service because they were < 40 percent maximum depth

using qualified Plus Point sizing techniques.

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PC" 4 I ~

1 Attachment 2PG8 E Letter DCL-99-122

TABLE 2PWSCC DETECTED IN 1R8, 2R8, 1R9

Outage SG C Loc +P CrackNo.

Dentvolt

BC +P Max.Volts

MD(%)

AD(%)

Length From(in.)

To Comment

1R8 11

1RS 11

1RS 11

1RS 11

1RS 11

1R8 11

1R8 11

1RS 11

1RS 11

1R8 11

1R8 11

1RS 11

1RS 11

1RS 11

1RS 11

1RS 11

1RS 11

1RS 11

1RS 11

1RS 11

1RS 11

1RS 121RS 121RS 121R8 12

2628282031

2315322920171021

251318232223152317

19

25 1H SAI27 1H SAI27 1H SAI29, 2H SAI31 1H SAI32 3H SAI33 2H SAI34 2H SAI36 2H SAI38 2H SAI39 3H SAI44 1H SAI44 2H SAI57 3H SAI60 2H SAI64 1H SAI64 1H SAI67 3H SAI70 2H SAI76 2H SAI84 2H SAI8 6H SAI10 3H SAI14 2H SAI16 4H SAI

0.892.412.410.510.861.981.103.801.812.054.081.651.930.582.876.161.061.121.790.901.552.844.800.699.61

NDDNDDNDDNDDDSSNDDNDDNDDNDDNDDNDDDSSDSSNDDNDDNDDNDDDSSDSSNDDDSSNDDNDDDSSNDD

1.18 531.29 590.49 250.82 401.17 561.40 700.91 351.41 350.41 221.24 370.91 251.01 492.06 31

0.44 21

0.81 340.62 280.78 280.60 260.49 20

520.71 391.83 341.22 351.14 301.26 25

221816

19

232821

2621

134246172835382425132216332413

0.18 0.130.12 0.120.14 0.260.17 0.050.10 0.410.23 0.000.19 -0.150.49 -0.180.39 -0.260.09 -0.200.20 -0.090.15 -0.170.40 -0.300.13 0.080.21 0.070.39 -0.190.31 -0.250.24 -0.050.24 -0.130.09 -0.140.14 0.000.30 -0.150.26 -0.040.2 -0.12

0.12 0.51

0.310.240.400.220.510.230.040.310.13-0.110.11-0.020.100.210.280.200.060.190.11-0.050.140.150.220.080.63

ID/OD

1RS 12 26 22 4H SAI 0.57 NDD 1.05 30, 24 0.22 -0.05 0.171RS 121RS 121R8 121RS 121RS 121R8 121RS 121RS 121R8 121RS 121RS 121RS 121R8 121RS 121R8 121R8 121RS 121RS 121RS 121RS 121RS 121RS 12

291329

32221910273431

31

32

21

22262932283234

22 2H SAI24 4H SAI24 3H SAI28 3H SAI30 2H SAI32 2H SAI34 2H SAI35 1H SAI36 3H SAI36 3H SAI37 3H SAI37 3H SAI37 3H SAI39 2H SAI42 1H SAI42 1H SAI43 2H SAI43 2H SAI44 4H SAI47 3H SAI47 3H SAI47 2H SAI

1.120.951.871.081.741.000.841.171.921.630.550.551.750.524.990.822.781.604.510.735.901.32

NDDDSSDSSNDDDSSDSSNDDNDDNDDNDDNDDNDDNDDNDDNDDDSSNDDDSSNDDNDDNDDNDD

1.40 553.79 581.45 360.66 390.55 291.49 521.33 380.79 361.29 260.79 200.74 200.47 200.71 200.63 361.32 401.60 460.98 221.29 431.18 320.98 261.99 371.03 34

324524231831

27251710

12

203034143317152721

0.31 -0.070.34 -0.120.13 0.100.18 -0.160.20 -0.090.07 -0.100.07 0.000.09 0.010.15 -0.170.49 -0.230.24 0.010.16 -0.140.20 0.060.15 -0.190.17 0.060.23 -0.20.10 0.03

0.34 -0.110.42 -0.200.20 0.110.10 -0.170.16 -0.20

0.230.220.31-0.07-0.040.240.220.230.020.11-0.030.070.10-0.020.260.250.020.26-0.040.230.030.13

g 0 R et<a'V

~ 0 ~ ~ 5 ~ ~ - ~ * ~ ~

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t Attachment 2PG8 E Letter DCL-99-122


Outage SG R C Loc +P Crack DentNo. volt

BC +P Max.Volts

MD(%)

AD(%)

Length From To(in.)

Comment

1RS1RS1RS1R81R81RS1RS1RS1RS1R81R81R81RS1R81RS

1RS1RS1RS1RS1R81RS1RS1RS1RS1RS1R81RS1RS1RS1R81RS1RS1R81RS1R81RS1RS1RS1R81RS1RS1RS1RS1RS1RS1RS1RS1RS

12 10 4912 43 4912 19 51

12 9 5312 21 5312 36 5312 4 5412 7 5612 28 5612 29 5612 35 5612 33 5712 5 5912 17 5912 34 5912 13 6012 17 6012 21 6012 6 6112 10 6212 30 6212 40 6312 18 6412 27 6412 5 6512 34 6512 5 6612 8 6612 17 6612 31 6612 10 6712 17 6712 35 6712 35 6712 2 6812 7 6812 14 6812 28 6812 31 6812 27 6912 27 6912 37 6912 37 6912 37 6912 6 7012 14 7012 38 7012 11 71

3H3H1H1H6H3H2H1H2H

2H2H1H1H2H2H2H2H2H1H1H1H3H3H1H2H2H2H1H4H1H1H1H3H1H3H1H6H1H1H1H1H1H3H2H1H1H1H

SAI 1 3.40"SAI 1 1.20SAI 1 0.55SAI 1 0.57SAI 1 2.17SAI 1 5.01SAI 1 0.93SAI 1 065SAI 1 0.40SAI 1 0.90SAI 1 1.75SAI 1 067SAI 1 070SAI 1 1.00SAI 1 0.81SAI 1 1.76SAI 1 2.72SAI 1 0.51SAI 1 19.49SAI 1 0.70SAI 1 2.14SAI 1 0.74SAI 1 1.46SAI 1 2.83SAI 1 0.6SAI 1 1.51SAI 1 3.26SAI 1 263SAI 1 0.79SAI 1 6.96SAI 1 2SAI 1 1.91SAI 1 1.22SAI 1 2SAI 1 1.43SAI 1 5.06SAI 1 1.62SAI 1 1.01SAI 1 1.12SAI 1 1.15SAI 2 1.76SAI 2 1.76SAI 1 1.76SAI 1 1.75SAI 1 1.1

SAI 1 6.82SAI 1 2.56SAI 1 2 78

DSSDSSDSSNDDDSSNDDDSSDSSDSSDSSNDDNDDDSSDSSNDDDSSNDDNDDNDDNDDNDDNDDNDDNDDNDDNDDNDDNDDDSSDSSNDDNDDNDDNDDNDDNDDNDDNDDNDDNDDNDDNDDNDDNDDDSSNDDNDDDSS

0.86 32 201.26 49 32

1.34 44 250.36 23 130.45 20 140 86 20 131.00 46 31

0.63 20 11

0.65 20 90.28 33 '60.43 21 150 61 20 100.49 25 100.83 24 150.33 22 141.84 45 361.27 39 240.80 20 100.73 40 31

1.48 33 210.89 20 100.84 26 130.68 21 11

0 91 20 180.51 20 13098 30 181.93 52 440.61 24 151.39 53 440.99 44 210.75 42 31

0.94 31 200.36 200.64 42 27035 34 19

2 44 58 401.11 39 241.97 55 380 44 27 130.91 27 171.50 30 220.98 37 171.53 31 210.52 20 130.65 37 241.22 49 301.27 55 38061 25 18

0.20 0.02 0.220.18 -0.23 -0.050.43 -0.28 0.150.28 -0.05 0.230.64 -0.35 0.290.11 -0.11 0.000.16 -0.06 0.100.12 -0.13 -0.010.27 -0.09 0.180.19 -0.03 0.160.18 0.00 0.180.07 0.10 0.170.33 0.00 0.330.19 -0.03 0.160.07 -0.01 0.060.31 -0.15 0.160.11 -0.21 -0.100.10 -0.23 -0.130.09 -0.40 -0.310.24 -0.05 0.190.12 -0.13 -0.010.13 -0.07 0.060.10 -0.17 -0.070.11 0.08 0.190.24 -0.21 0.030.10 -0.01 0.090.12 -0.08 0.040.08 -0.30 -0.220.35 -0.22 0.1 30.19 -0.01 0.180.36 -0.28 0.080.16 0.07 0.230.33 -0.12 0.210.20 0.33 0.530.14 0.17 0.310.15 0.15 0.300.38 -0.20 0.180.11 0.03 0.140.19 0.01 0.200.39 -0.22 0.170.08 0.06 0.140.24 0.12 0.360.25 -0.12 0.130.22 0.03 0.250.14 -0.09 0.050.14 -0.09 0.050.08 -0.01 0.070.07 0.11 0.18

n ~ ~ ~

Attachment 2PG&E Letter DCL-99-122


Outage SG R Loc +P CrackNo.

Dentvolt

BC +P Max.Volts

MD(%)

AD(%)

Length From(in.)

To Comment

1RS 12 11

1R8 12 11

1RS 12 11

1RS 12 261R8 12 261R8 12 141R8 12 241RS 12 331R8 12 161RS 12 31

1RS 12 37

71

71

71

71

71

727272737373

1H SAI 21H SAI 31H SAI 42H SAI 22H SAI 1

2H SAI 1

1H SAI 1

4H SAI 1

1H SAI 1

4H SCI 1

3H SAI 1

2.782.782.781.021.022.591.612.2319.018.381.83

DSS 0 32 20DSS 0 27 20DSS 1.18 47DSS 0.79 33DSS 0.86 23NDD 0 77 20NDD 0.44 25NDD 0 82 27NDD 0.67 20NDD 0 40DSS 0.86 22

362517

181510

13

0.13 0.120.10 -0.060.33 -0.220.23 -0.140.14 0.140.14 0.050.21 -0.090.21 -0.090.17 -0.27

34 deg0.20 -0.03

0.250.040.110.090.280.190.120.12-0.10

0.17SCI

1R8 12 141RS 12 26 74

1H SAI 1

1H SAI 1

10.482.74

NDD 1.33 19NDD 0 21 33

0.21 -0.1923 0.06 0.41

0.020.47

1R8 12 16 76 2H SAI 1 0.82 NDD 0 59 20 10 0.11 -0.09 0.021RS 12 201RS 12 351RS 12 351RS 12 51RS 12 21RS 12 21RS 12 11

77777778797981

1H SAI 1

1H SAI 21H SAI 1

1H SAI 1

3H SAI 1

3H SAI 22H SAI 1

0.873.563.460.341.621.621.8

DSS 1.15 31

NDD 0.85 29NDD 1.03 40NDD 1.08 22NDD 0.66 20NDD 0 85 20NDD 0.95 20

2415

0.21 -0.110.15 -0.15

22 0.08 0.0813 0.23 0.06

0.18 -0.1610 012 003

0.09 0.11

0.100.000.160.290.020.150.20

1RS 12 131RS 12 14

81

821H SAI 1

1H SAI 1

3.211.63

NDD 0.92 25NDD 0.72 20

1312

0.28 -0.170.15 -0.26

0.11-0.11

1RS 12 16 82 4H SAI 1 2.64 NDD 0.63 25 12 0.18 0.00 0.181R8 12 161R8 12 101RS 12 41RS 12 101R8 12 161R8 12 161RS 12 51RS 12 251RS 12 51RS 12 21RS 12 21R8 12 51R8 14 381RS 14 381RS 14 38

828384858585878789909093242427

1H SAI 1

1H SAI 1

1H SAI 1

4H SAI 1

2H SAI 1

2H SAI 25H SAI 1

4H SAI 1

5H SAI 1

4H SAI 1

4H SAI 21H SAI 1

3H SAI 1

3H SAI 21H SAI 1

1.956.952.540.771.221.221.230.622.463.893.892.731.231.23

13.73

NDD 0 58 33NDD 1.08 27NDD 0.68 20NDD 0.57 20NDD 0.78 36NDD 0.50 23NOD 1.21 48NDD 1.37 50NDD 1.81 42DSS 0.52 20DSS 1.17 50NDD 0.59 20NDD 1.04 38NDD 0 83 32NDD 1.49 41

1616

2012393333

211324"2024

0.24 -0.070.29 -0.210.16 0.000.11 0.160.10 -0.230.14 -0.130.48 -0.230.21 -0.090.39 -0.300.11 -0.330.20 -0.130.08 -0.080.14 -0.070.12 -0.200.17 -0.20

0.170.080.160.27-0.130.010.250.120.09-0.220.070.000.07-0.08-0.03

1RS 14 11

1R8 14 351RS 14 91R8 14 91RS 14 9

3036383838

3H SAI 1

2H SAI 1

2H SAI 32H SAI 22H SAI 1

0.180.650.780.780.78

NDD 0.25 20NDD 0.47 20DSS 0.47 24NDD 0.45 20NDD 0.72 20

10 009 05316 0.17 0.1610 0.14 2.929 0.14 1.91

11 0.14 0.34

0.620.333.062.050.48

1R8 14 39 48 3H SAI 1 1.98 NDD 0.46 20 12 0.15 0.09 0.241R8 14 391RS 14 391RS 14 39

586060

1H SAI 1

2H SAI 23H SAI 1

2.420.50.5

NDD 0.94 20DSS 2 52 80DSS 1.56 58

10

57 0.61 -0.2735 0.36 -0.32

13 0.23 0.09 0.320.340.04

~ ~ t ~ ~ t 'I



Outage SG R C Loc +p Crack DentNo. volt

BC +P Max.Volts

MD(%)

AD(%)

Length(in.)

From To Comment

1RS1RS

1RS2RS2RS2RS2RS2RS2RS2R82RS2RS2R82RS2RS2R82RS2RS2RS2RS

14

14142222222222222222222222222224222424

39 60 2H20 63 3H21 84 1H32 24 1H12 28 1H5 35 1H

17 50 1H33 38 1H14 29 4H4 28 1H3 26 1H

12 51 1H10 26 1H17 36 1H6 24 1H14 45 1H8 24 3H

18 16 1H4 37 3H6 22 3H

SAISAISAISCISAISCISCISAISAISAISCISCISAISAISAISAISAISAISAISAI

1 1.21

1 7.311 1.221 39.691 20.461 20.311 17.331 15.401 12.241 10.431 9.221 8261 8181 7.841 7.641 7.311 5.941 5.691 4.941 4.45

DSS 0.64NDD 0.13NDD 0.71NDD 0.60NDD 0.94NDD 0.79NDD 0 53NDD 0.52NDD 0.46NDD 0.65NDD 0.43NDD 0 33NDD 0 38NDD 0.48NDD 0.62NDD 0.42NDD 0.84NDD 0 63NDD 0.50NDD 0.44

322025

34

373320

322821

24363931

38

16 0.1315 0.19

23 deg31 deg

21 0.0918 0.1610 0.1710 0.1225 0.1828 0.1618 0.0926 0.10

19 0.330.06

16 0.1636 deg

24 0.1419 deg48 deg

27 0.14

-0.130.000.01

-0.18

-0.480.130.04

0.510.51-0.33-0.060.420.40-0.540.16

0.200.060.17

-0.04

-0.340.260.23

0.600.67-0.160.060.600.56-0.450.26

SCI

SCISCI

SCISCI

2R8 24 34 34 3H SAI 1 296 DSS 0.38 36 26 0.16 0.11 0.27 ID/OD2RS2RS2RS2RS2RS2R82RS2RS2RS2RS2RS2RS2RS2RS2RS

222222222222242222222222242223

10 36 1H14 15 2H8 43 4H

19 15 1H5 3 1H

22 45 1H11 17 3H15 42 1H18 44 1H12 50 1H22 44 4H2 2 1H17 20 2H12 39 1H19 78 1H

SCISAISAISAISAISAISAISAISAISAISAISAISAISAISAI

1 2831 2801 2.211 2201 1.811 1.711 1.621 1.201 1.101 0991 0.931 0.791 0.641 0601 059

NDD 1.9DSS 0.36NDD 0.42NDD 0.70NDD 0.55NDD 0.81

NDD 0.40NDD 0.57NDD 0.37NDD 0.39NDD 0.49NDD 0 53NDD 0.65NDD 0.40NDD 0.52

2820243429342038392043392631

19 0.1625 0.3112 0.1730 0.1831 0.412 0.0925 0.1028 0.1616 0.1025 0.16

35 deg19 0.1710 0.0717 0.0920 0.29

-0.27-0.06-0.01-0.27-0.11-0.13-0.07-0.07-0.17'-0.34-0.07-0.03-0.10-0.18

-0.100.010.080.020.050.180:100.110.23-0.250.030.130.00-0.02

SCI

2R8 23 19 78 1H SAI 2 059 NDD 0.73 39 19 0.14 -0.02 0.121R91R91R91R91R91R91R91R91R91R91R9

9 6'H22 7 3H23 14 3H19 15 3H24 20 2H30 21 2H34 24 3H14 27 2H36 30 2H20 33 1H38 42 3H

SAISAISAISAISAISAISAISAISAISAISAI

1 095

1 1.291 0991 1.261 2.481 0.861 208

1.161 0821 1.45

NDD 0.38NDD 0.86NDD 0.37NDD 0.69DSS 0.65NDD 0.45NDD 0.30NDD 0.36NDD 0.66NDD 0.25NDD 0.28

3731343436202843362544

10 0.1813 0.2021 0.1424 0.1414 0.0931 0.12

27 0.1323 0.1623 0.1121 0.1525 0.06

-0.10-0.08-0.10-0.060.01-0.17-0.03-0.16-0.21-0.140.01

0.03 ID/OD0.08 LIS0.01 LIS0.09 LIS0.07 LIS0.01 LIS0.17 LIS-0.02-0.07 LIS-0.05 LIS0.13

I

~ qcwW * ~ e

~ '



Outage SG C Loc +P CrackNo.

Dentvolt

BC +P Max.Volts

MD(%)

AD(%)

Length(in.)

From To Comment

1R91R9

2222

71 2H SAI76 3H SAI

0 9 NDD 0460.45 NDD 0.22

3347

25 0.1033 0.15

0.00-0.01

0.100.14

LIS

1R91R91R91R91R91R91R91R91R91R9

1212

1212121212

1212

20171525

21

80 2H SAI9 6H SAI10 1H SAI17 2H SAI27 3H SAI27 1H SAI28 2H SAI28 1H SAI31 1H SAI33 3H SAI

0.59 DSS 1.112.29 NDD 0.382.15 NDD 0.411.16 NDD 0.491.43 NDD 0.221.89 NDD 0.742.26 NDD 0.502.47 NDD 0.661.82 NDD 0.38299 NDD 088

49433423574747422737

33 0.1036 0.4334 0.0630 0.1218 0.0827 0.16

37 0.2526 0.0823 0.1616 009

-0.34-0.09-0.13-0.19-0.18-0.23-0.10-0.230.01-0.07

-0.09-0.010.03 LIS-0.10 LIS-0.080.20-0.04-0.110.09 LIS0.09 SAI/SCI

1R91R9

1212

2122

33 3H SCI34 2H SAI

2.99 NDD 0.930.85 NDD 0.41 40

72 deg28 018 -0.12 0.06

SAI/SCI

1R9 12 26 39 2H SAI 0.91 NDD 0.41 28 19 0.07 -0.04 0.03 LIS1R91R91R91R91R91R91R91R91R91R91R91R91R91R91R91R91R91R91R91R91R9

121212121212121212121212121212121212121212

20272935

25162136

3833

2719371318

45 1H SAI47 1H SAI47 2H SAI48 3H SAI50 1H SAI51 2H SAI52 3H SAI53 3H SAI55 2H SAI57 1H SAI57 1H SAI60 4H SAI61 2H SAI66 1H SAI68 2H SAI69 1H SAI71 1H SAI74 2H SAI74 3H SAI75 2H SAI75 4H SCI

12.87 NDD 0.660.77 DSS 0.35211 NDD 0550.14 NDD 0.511.53 NDD 0.5409 NDD 029

3.61 NDD 0.661.05 NDD 0 331.16 NDD 0.37514 DSS 0551.02 DSS 1.493.18 NOD 0.571.96 NDD 0.260.75 NDD 0.590.82 NDD 0.301.19 NDD 0 331.57 NDD 0.940.84 NDD 0.270.85 DSS 1.232.23 NDD 0.4210.61 NDD 0.57

222640252831

284023286631

3122392038

5020

170.300.12

18 0.0650 0.3722 0.1223 0.0914 0.1124 0.0713 0.1328 0.1512 0.1042 0.3011 0.11

24 deg

23 0.1317 0.1417 0.0717 0.1015 0.2521 0.1411 008

-0.08-0.05-0.14-0.09-0.22-0.14-0.200.000.14-0.15-0.19-0.170.110.050.04-0.04-0.17-0.14-0.080.00

0.22 LIS0.07 ID/OD-0.010.05 LIS-0.15 LIS-0.04 LIS0.05 LIS0.140.22 LIS-0.09 Tube Pull0.18-0.05 LIS0.20 LIS0.16 LIS0.11 LIS0.09 LIS-0.02 LIS-0.04 LIS0.220.11 ID/OD

SCI1R9 12 77 5H SAI 1.25 NDD 0.59 33 21 0.12 -0.21 -0.09 LIS1R91R91R91R91R91R91R91R91R91R91R9

1212121212121212121212

26

23

13

79 1H SAI80 4H SCI80 2H SAI82 3H SAI82 1H SAI84 1H SAI84 1H SAI86 5H SAI87 4H SAI90 3H SAI91 1H SAI

1.02 NDD 0.4164 NDD 039

0.68 NDD 0.391.42 NDD 1.031.17 NDD 0 28673 NDD 0790.47 NDD 0.62329 NDD 0331.03 NDD 0.171.87 NDD 0.533.24 NDD 0.07

39

204725393228203420

23 0.2038 deg

12 0.1230 0.2016 0.0730 0.1020 0.0716 0.07

0.1323 0.1110 0.03

-0.08

-0.220.080.14-0.51-0.04-0.28-0.07-0.120.16

0.12 LISSCI

-0.100.280.21 LIS-0.410.03 LIS-0.21 Wedge0.06 Wedge-0.01 Wedge0.19 LIS

Attachment 2PG8 E Letter DCL-99-122

~ ~


Outage SG R C Loc +P CrackNo.

Dentvolt

BC +P Max.Volts

MD(%)

AD(%)

Length(in.)

From To Comment

1R9 121R9 141R9 141R9 141R9 14

1R9 141R9 141R9 14

1R9 141R9 141R9 141R9 141R9 14

172035463935393521

21

92 5H SAI24 1H SAI25 1H SAI36 2H SAI42 1H SAI48 3H SAI56 3H SAI58 1H SAI68 3H SAI76 1H SAI84 1H SAI86 1H SAI89 1H SAI

3.57 NDD 0.380.71 NDD 0.33683 NDD 0250.55 NDD 0.492.14 NDD 0.421.79 DSS 0.390.74 NDD 0.413.24 DSS 0.621.87 NDD 0.473.93 NDD 0.451.17 DSS 0.651.89 NDD 0.07696 NDD 008

202020203020

203829292020

13122014

13252018

0.090.110.140.120.150.180.090.160.140.160.070.090.27

-0.04 0.05 LIS0.30 0.41-0.68 -0.540.14 0.26 Deplug-0.11 0.040.05 0.23 Deplug0.01 0.100.09 0.25 Deplug-0.13 0.01-0.17 -0.010.02 0.09 Deplug0.25 0.340.12 0.39

Legend:+P - Plus Point callBC - Bobbin coil callSAI - single axial indicationSCI - single circumferential indicationDSS - distorted support signalNDD - no detectable degradationLIS - left in serviceDeplug - tube was deplugged and returned to serviceID/OD - intersection had both ID and OD flawMD, AD, Length - maximum depth, average depth, and length of the SAI as adjusted byPWSCC sizing software.

13

Attachment 2PG&E Letter DCL-99-122

TABLE 3STRUCTURALLYLIMITINGSAI DETECTED IN 1R8, 2R8, 1R9

THATWERE NDD BY BOBBIN

Outage SG R

1R8 11 231R8 12 271R8 12 5

2R8 22 121R9 12 11

6469875027

Loc +P CrackNo.

1H SAI 1

IH SAI 1

5H SAI 1

1H SAI 1

1H SAI 1

Dentvolt

1.061.151.230.991.89

BC +P AD LengthMax. (%) (in.)Volts

NDD 1.40 38 0.31NDD 1.93 44 0.39NDD 1.21 39 0.48NDD 1.9 31 0.40NDD 0.74 36 0.43

EOCAD%

606661

5056

EOCL in.

0.550.630.720.620.66

14

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