NOC-AE-11002722, RE16 Inspection Summary Report for Steam Generator Tubing

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RE16 Inspection Summary Report for Steam Generator Tubing
ML11272A126
Person / Time
Site: South Texas STP Nuclear Operating Company icon.png
Issue date: 09/21/2011
From: Gerry Powell
South Texas
To:
Document Control Desk, Office of Nuclear Reactor Regulation
References
NOC-AE-11002722
Download: ML11272A126 (50)
v • d • e


Text

Nuclear Operating Company South Txas Pro/ect E1ectric Generatin Station P.O Box 289 Wadswvorth, Texas 77483 September 21, 2011 NOC-AE-1 1002722 File No.: G25 10 CFR 50.55a U. S. Nuclear Regulatory Commission Attention: Document Control Desk One White Flint North 11555 Rockville Pike Rockville, MD 20852-2738 South Texas Project Unit 1 Docket No. STN 50-498 1RE16 Inspection Summary Report for Steam Generator Tubinq Enclosed are four copies of the summary report describing the results of the South Texas Project Unit 1 steam generator tube inspection performed during refueling outage 1 RE1 6. The summary report satisfies the reporting requirements of ASME Section Xl, Article IWA-6230, and Section 6.9.1.7 of the South Texas Project Technical Specifications. This report provides the information required by Technical Specification 6.8.3.o for maintaining steam generator tube integrity.

There are no commitments in this letter.

If there are any questions regarding this report, please contact either Mr. P. L. Walker at (361) 972-8392 or me at (361) 972-7566.

G. T. Powell Vice President, Technical Support & Oversight PLW

Enclosure:

1RE16 Inspection Summary Report for Steam Generator Tubing of the South Texas Project Electric Generating Station Unit 1 STI: 32919836

NOC-AE-1 1002722 Page 2 of 2 cc: (one copy of attachment)

(paper copy) (electronic copy)

Regional Administrator, Region IV John Ragan U. S. Nuclear Regulatory Commission Catherine Callaway 612 East Lamar Blvd., Suite 400 Jim von Suskil Arlington, Texas 76011-4125 NRG South Texas LP Balwant K. Singal A. H. Gutterman, Esquire Senior Project Manager Morgan, Lewis & Bockius LLP U.S. Nuclear Regulatory Commission One White Flint North (MS 8B1) 11555 Rockville Pike Balwant K. Singal Rockville, MD 20852 U. S. Nuclear Regulatory Commission Senior Resident Inspector Richard Pena U. S. Nuclear Regulatory Commission Ed Alarcon P. O. Box 289, Mail Code: MN116 Kevin Polio Wadsworth, TX 77483 City Public Service C. M. Canady C. Mele City of Austin City of Austin Electric Utility Department 721 Barton Springs Road Peter Nemeth Austin, TX 78704 Crain Caton & James, P.C.

Richard A. Ratliff Texas Department of State Health Services Alice Rogers Texas Department of State Health Services One copy of the attachment is provided.

a Mr F IREI6 INSPECTION

SUMMARY

REPORT FOR STEAM GENERATOR TUBING of the SOUTH TEXAS PROJECT ELECTRIC GENERATING STATION UNIT I P.O. BOX 289 WADSWORTH, TEXAS 77483 Commercial Operation: August 25, 1988 Issue Date: September 13, 2011

IREI6 INSPECTION

SUMMARY

REPORT FOR STEAM GENERATOR TUBING of the SOUTH TEXAS PROJECT ELECTRIC GENERATING STATION UNIT I USNRC DOCKET NO.: 50-498 OPERATING LICENSE NO.: NPF-76 COMMERCIAL OPERATION DATE: August 25,1988 Prepared By:

D. A. Stuhler Date Approved By: IGO / /

Date Test Engineering

Attachment NOC-AE-1 1002722 Page 1 of 10 SOUTH TEXAS PROJECT UNIT I IREI6 INSPECTION

SUMMARY

REPORT FOR STEAM GENERATOR TUBING Introduction This summary report describes the inspection of steam generator tubing at South Texas Project (STP) Unit 1 performed during refueling outage 1RE16 in April 2011. Eddy current inspection, sludge lancing, and Foreign Object Search and Retrieval (FOSAR) were conducted in steam generators (SG) 1A, 1B, 1C, and 1D. Due to previous operating experience related to loose parts, a more aggressive inspection scope was developed for SG 1 D. Additional inspections of the secondary side of SG 1A and 1 B were also performed.

The eddy current inspection performed during 1RE16 completed the first interval inspection requirements for all Unit 1 steam generators. The outage was performed following 118.83 effective full power months cumulative service with the Delta 94 replacement steam generators.

This report provides the information required by Technical Specification 6.8.3.o for maintaining steam generator tube integrity and the reporting requirements of Technical Specification 6.9.1.7.

Scope of Examination The Inspection Plan, "1RE16 Steam Generator In-Service Inspection Outage Plan April 2011,"

identified the steam generator tube areas to be examined by eddy current testing and the related procedures to be used during the inservice inspection. A Degradation Assessment written prior to the outage established the following scope of primary and secondary side inspections:

Primary Side Inspection Scope 0 Full length Bobbin inspection of the outer three peripheral tubes from tube end to tube end, including 10 tubes inwards into the no-tube lane from the periphery.

0 50% Full length bobbin inspection of all tubes. Scope includes all remaining tubes not inspected full length during 1 RE13.

  • 20% +Point inspection of the upper tube support plate (TSP) hot leg (HL) to upper TSP cold leg (CL) on Rows 1 and 2 (u-bend).

0 +Point inspection of outer three tubes of periphery and divider lane top-of-tubesheet (TTS) +6 inches/-3 inches to aid in loose part detection (HL and CL).

  • 20% Sample +Point inspection of tubesheet-hot (TSH) +6 inches/-3 inches.
  • >20% Sample +Point inspection of TSH +6 inches/-16 inches in tubes with bulges and overexpansions. Of 95 anomalies inspected, 65 are in SG 1A, 18 in SG 1B, five in SG 1C, and seven in SG 1D.
  • +Point inspection of all previously identified dents and dings >5 volts.
  • +Point inspection of all prior and 1RE16 "I-code" and/or non-quantifiable indications as determined by bobbin inspection or any previously reported signal that has changed.

Attachment NOC-AE-1 1002722 Page 2 of 10

" +Point inspection of potential loose parts in the eddy current database as identified by previous eddy current inspections.

  • +Point inspection of all observed loose parts as identified by previous secondary side video inspections and not removed.
  • +Point inspection of a minimum two tube locations surrounding any new potential loose part or foreign object identified in 1 RE16.
  • Video inspection of all installed plugs.

Secondary Side Inspection Scope

" TTS FOSAR in all four SGs including annulus and tube lane.

  • TTS In-bundle FOSAR as follows:

o SG 1A inspect every fourth column both HL and CL beginning with Column 1.

o SG 1 B inspect every fourth column both HL and CL beginning with Column 2.

o SG 1C inspect every fourth column both HL and CL beginning with Column 3.

o SG 1D inspect every second column both HL and CL beginning with Column 1.

" Ultra sludge lancing on all four steam generators.

  • Sludge collector inspection and cleaning (if required based on inspection) in SG 1A.

Sludge collectors to be cleaned if more than 0.5 inch of sludge is observed.

  • Steam drum inspection in SG 1A and lB.

" Upper steam drum inspection of SG 1A.

  • Video probe inspection of ninth support plate on SG 1A.
  • FOSAR of all loose parts left in service during 1RE13 (SG 1A, 1B, and 1C) and 1RE14 (SG 1 D), if reachable by tooling.

" FOSAR of all potential loose parts identified by eddy current inspection, where possible.

Examination Results Table 1 provides a summary of the 1RE16 eddy current indications reported, while Tables 2A-D show the indication distribution. Table 3 and Table 4 provide details of the potential loose part (PLP) calls and reported volumetric (VOL) calls, respectively.

No tube corrosion or wear indications related to Anti-Vibration Bars were reported during the 1RE16 inspections. A few benign signals were observed, including dings/dents (DNG/DNT),

manufacturing burnish marks (MBM), and signals cleared as free from degradation (NQS) by motorized rotating pancake coil (MRPC) (+Point) examination. Signals representative of tube diameter increases (bulges- BLG) were also reported from the bobbin inspection analyses.

Benign signals in the 1RE16 inspection data were assessed by reviewing the prior available inspection data. If the historical lookup did not support the classification as a pre-existing benign signal or the signal exhibited a significant change, they were resolved by MRPC inspection. All identified benign signals are to be inspected in future outages as required by EPRI guidelines.

Attachment NOC-AE-1 1002722 Page 3 of 10

+Point sample inspection of previously reported tubesheet anomalies based on proximity to the expansion transition was performed. 95 anomalies (65 in SG 1A, 18 in SG 1B, five in SG 1C, and seven in SG 1D) were inspected. No degradation was found. This inspection will be the basis for potential future +Point programs should it become necessary in future outages to inspect such locations for primary water stress corrosion cracking (PWSCC), currently regarded as a non-relevant damage mechanism in the Unit 1 replacement steam generators (RSG) due to the Alloy 690TT tubes' resistance to PWSCC.

As noted in Table 3, a total of 104 PLP calls were reported in 1RE16. As required by EPRI guidelines, coordination between the eddy current and secondary visual inspection results was maintained. For those PLP locations where secondary access was available, tube locations showing PLP signals by eddy current were visually inspected to identify the source of the signal.

In addition, all TTS tube locations where foreign objects were identified during visual inspections were included in the TTS +Point inspection program. As seen in Table 3, no PLP calls were reported in SG 1A, three calls were reported in SG 1B, six calls were reported in SG 1C, and 95 calls were reported in SG 1 D. No tube wear was reported associated with any of the PLP calls.

All new PLP calls were "boxed-in" by additional eddy current inspections. Disposition of legacy PLP calls was based on reviewing historical and 1RE16 eddy current data for PLP signals and wear.

Table 4 lists the thirteen reported VOL calls with their through-wall depths. Seven locations in SG 1D were legacy TTS wear. The foreign objects causing the wear were removed during previous inspections and no change in the wear signals was noted. The remaining six VOL calls are new indications. Three of the new VOL calls reported in SG 1C (R112C48 CL, R110C48 CL, and R111C47 CL) were caused by a weld slag remnant which has since been removed. Through-wall wear depths were 6%, 9%, and 9%, respectively. In addition to the TTS wear noted, three TSP locations in SG 1A (R1 26C88 6th TSP HL) and SG 1B (R1 0C50 9th TSP CL and R3C155 6th TSP HL) exhibited low level wear. The low level wear indications correspond with the trefoil land contact and are slightly inward from the edge. The cause of the wear is most likely related to a small manufacturing burr at one of the trefoil lands.

Within the noise of the bobbin data is a very small signal measuring approximately 4%. The signals are very much like the residual on each edge of the TSP. For the 1RE16 inspection, the overall noise was less, the mix residual a little less, and the signal was therefore more defined from its surroundings. Wear at TSP is considered a "potential degradation mechanism" for the RSG's within the 1RE16 Degradation Assessment.

The level of TSP wear observed during 1RE16 will not have an impact on future SG inspection scope, nor limit the planned three cycles of operation prior to the 1RE1 9 outage. No wear due to stabilizer wire or corrosion-induced degradation was observed. Site-specific eddy current detection and sizing techniques qualified in accordance with EPRI non-destructive examination guidelines were used to perform the analyses. All VOL indications were evaluated against the in situ screening criteria. No burst or leak testing was required, and no tubes were removed from service.

PLP calls resolved via secondary side visual inspection where access allowed are listed in Table 5.

Attachment NOC-AE-1 1002722 Page 4 of 10 Table I - Summary of Eddy Current Indications Reported During IREI6 Deposit Signal 0 2 0 0 Free Span Dings 384 15 292 144 Distorted Dent! Ding Indication Not SConfirmed 21 2 4 188 17 1

Dents ( at supports and baffles) 2 0 18 0 Distorted TS Indication Cleared 0 1 1 0 Indication Not Found 0 3 2 104 Distorted Support Signal 1 0 1 3 Indication Not Reported 125 18 56 119 Manufacturing Burnish Mark 142 126 142 155 No Detectable Degradation 7845 8275 8108 8176 Degradation Not Found 325 53 38 9 Non-Quantifiable Signal 29 34 26 28 Previous Rotating Call 3 2 0 5 I Previous Bobbin Call 3 2 3 5 Potential Loose Part 0 3 6 95 Percent 1 1 0 0 Retest Bad Data 126 40 148 27 Retest Incomplete 6 10 11 2 Retest Due to Tube Restriction 0 2 10 0 Retest Due No Data 0 0 2 0 Volumetric 1 2 3 7Notei Notel Legacy wear indications

Attachment NOC-AE-1 1002722 Page 5 of 10 Table 2A- IRE16 Indication Distribution Report for Steam Generator 1A cde tell

'.ST BH -:EH**H *  ;** i1: .. 03H '..04H "- 05H ',I :061H " 07H * - "08H. .., 09H .. V C6de

, TSH FBHI- 018 02H 5 6 ~1 8 9 AVB1 ONG 1 1 1 1 1 180 2 2 DNS - 11 -

DNT - 2 SS - 1 -1 INR I -1 2 2 1 1 1 3 4 2 1 5 52 1 MBMB 3 4 1 7 7 9 3 4 3 19 1 4 7 NDF 5 160 - - - - - - - - - - - 58 -

NOSi - 1 1 1 4 2 2 2 1 3 2

-B - - - - - - - I -1 - 1 - 1

~RIC.

Code " 08C 0C76 0.. 05C 04C 03C, 02C,  : 01C ..BC TSC TEC DNG 1 192 1 1 DNS - 10 -

ODNT a ss -

INR 1 36 3 1 2 1 1 1 - 1 -

MBM I - 10 9 9 ,5 6 5 1 9 9 1 1 3 -

NOF.- 95 - - - - - - - - 7

':NOS 1 1 2 -1 11 - 1

'PB - - - I - 2 PCT - - - - - -

RBD -

VOL - --

Attachment NOC-AE-1 1002722 Page 6 of 10 Table 2B1- 1RE16 Indication Distribution Report for Steam Generator lB Code TEH 'TSH 'FBH 01 H 026 ~03HO04H 05H ~06H 07H' 08H 'C)9H' AVS ON-- _ -2 1 2 1 DNS - - - - - - - - - - - ¶ - - - -

DNT -:: - -

DSS -

INR~ 5 1

BM'W - 2 1 4 4 3 5 6 10 5 10 - 2 7 NDF 2 19 - - - - - - - - - - - 5 -

NOS - - 2 1 1 2 2 5 1 3 1 PCT'__1 PLP - 3 - - - - - -

.'PRC--- - 2 DEP -

VOLd - - - o- o- - - - c - - - - I -:- - -,-....

Code 09C .. .08C.07C0 05C 04C 3C: 02C 01C FBC - TS TEC

DNG 3 411 DNS - - 1 - - - - - -- - - - - - - - - - - 1 sINF3/4 - - 3 INR 2 22 .. 2 -

'IB N1 2 1 9 20 8 4 6 4 - 2 7 2 - -

NOF - - - - - - - - 4- - - - 3 23 NOS - 3 1 2 1 2 1 - I -1 4 -

PBC: - - - -,

PLP -

RRT - - - - - - -

- 1 - L -

Attachment NOC-AE-1 1002722 Page 7 of 10 Table 2C - IREI6 Indication Distribution Report for Steam Generator 1C Code TEH :TSH .. ,T H 1H 02H 031H 04H 05H 06H 07H 0*... S&* 109HW AVB DNG - 2 1 1 21 4 1 DNS - - - - -

DNT --- - 18

'DTS -: 1 INR;, 2 1 4 1 2 1 11 1

MBM 7 1 7 3 5 3 9 3 5 - 7 3 8 NDF 1 2 2 - - - - 19 - -

NOS - - -1 2 1 3 - 2 - 2 1 PBC 1 1 -- 1 PCT. "--

PLP 6 INF - - --

VOL Code 09C 08C> -07C

  • 06 05C 04C * '03C 02C .01.OC- FF. g . TSC TEC ONG 130 - 42 90 -

DNS 14 2 -1 -

ONT - - - -- - -

INF - 1 - - - - -

INR' 1 16 1 1 1 6 2 1 2 - 1 I - - -

'MBM. 2 - 8 - 8 - 12 9 10 10 7 1 4 3 - 6 1 NDF' - 9 - 4 - - -

,N(OS" - 1 2 - 2 - 2 I -

PCT, - - -

RRT . . 8 - 2 - -

RIC -

VOL _- -. 3 -

Attachment NOC-AE-1 1002722 Page 8 of 10 Table 2D - 1RE16 Indication Distribution Report for Steam Generator ID

~Cod~eTEH~ TSH FBH - 01H-I 02H ~§03H '04H *TO5H, 06H~ OT0H ~8H 0 09H1 AVB DNG -- - 1 DSS - - 2 D 1NT -

/INF 9 5 16 6 4 - -

INR 2 - 12 2 4 2 2 3 2 - 1 7 1 2 5 1 AMBM - 4 2 7 5 9 1 4 4 - 4 14 - 10 6 7 NDF. 1 6 - 1 2 NOS - 2 -- 2 3 3 - 3 PBQ,- 1 1 2 - - -

IPLP 4 2 60 2 10 -

PRRC - 4 - - - -

voL 3 Code 1-09Cý - 01BC J"07C 06C* 05C', 4C'03C 01CýFBCý 01C TSC* TEC bNb 1- 39 94 - 9 DNS - 6 5 5 - 1 -

ANF ---- 1 24 14 25 o0ss - - - - _ I -- -- - - - - - -

>INR - 1 11 1 27 3 5 - 1 5 - - 14 2 2 MIBM 1 - 14 - 10 - 4 - 11 8 - 11 - 10 6 1 - 2 -

NDF -- - - - - - - - -

  • NQS 3 2 - 1 2 - 3 3
.PBC' ....- - -

PCvoT ---- , - 2-

~PLP - - - -- - - - - - - - - - 3 14 - -

PRO C VOL - - - - - -- - - -- - - - - - - 2 2

Attachment NOC-AE-1 1002722 Page 9 of 10 Table 3 - Summary of IREI6 Potential Loose Part Calls SG Outage TS FDB 1 TSP"?

IHLý, _CL HL, CL HL I CL A IREI13 0 0 0 '0 01 0 IRE16 0-1 o a 0. G 0.

B IRE 5, '

C, .REi3 1REi6*&_ 0__:__ 6" AiREJ!6. 6. 0 0 0- 0 S 1RE:14. 10 24 976 7 18 1,

_ _RE_6

_.0 627 I 10: 0, Table 4 - Summary of IREI6 Volumetric Calls SG Location KThroughwall Depth (%) Comment, A R126C88 HL 6rn TSP 6 Low level signal noted in IRE12 R3C155 HL 62 TSP 9 Low level signal noted in 1RE12 R10C50 CL 91' TSP 9 Rl12C48 CL TTS 34 C R110048 CL TTS 19 iRE16 Identified Weld slag -weld slag removed R101C47 CL TTS 13 R70C140 HL TTS 9 R84C22 HL TTS 21 R84C24 HL TTS 5 D R2C138 CL TTS 8 7- Legacy Calls R2Ct38 CL TTS 9 R116C48 CL TTS 18

  • 7 R99C35 CLTTS 8

Attachment NOC-AE-1 1002722 Page 10 of 10 Table 5 - IREI6 Top of Tubesheet Potential Loose Part Visual Inspection Results

*SG ID Row Column' Leglý' Elevation Comment PLP-B-001 88 58 HL TrS +0.16' Legacy object from IRE 14 - object not removed

, PLP-B-002 87 59 HL TT+0.1 1" Legacy object from 1RE14 - object not removed PLP-B-003 75 69 HL TTS+0.26" Legacy PLP call from IREI3 PLP-C-001 104 38 HL TTS+0.05"

..... 1FOSAR Object IC015 - Object retrieved PLP-C-002 103 39 HL TTS÷0.18'

" PLP-C-003 87 121 HL TTS÷0.01" PLP-C-004 89 121 HL TTSý0,28" FOSAR Object 1CO16 - Object retrieved PLP-C-005 90 122 HL TTS+0.18" PLP-C-006 88 122 HL TrS+0.16" PLP-D-006 81 25 HL TTS+0.02 FOSAR object 10073 or 1D074 - object not removed PLP-D-034 121 69 HL TTS+0.06 FOSAR Object 1D039 - object not removed D PLP-D-037 86 84 HL: TTS +2.150 Nothing seen PLP-D-052 118 104 HL TTS÷004 Sludge rock - object not removed 7 D057 57 13Sludge rock 1D006 - legacy seen in IRE14 - object not PLP--057 57 113 HL TTS002 removed Plug Inspection Results All installed plugs were visually examined. No anomalies were noted.

Tube Plugging The total number of tubes plugged per steam generator to date is as follows:

Steam Generator 1A 33 0.44%

Steam Generator 1 B 40 0.53%

Steam Generator 1C 26 0.34%

Steam Generator 1D 13 0.17%

No tubes were plugged during 1 RE16.

Condition Monitoring Conclusion Based on the Condition Monitoring evaluation, inservice inspection of tubes in service during Cycle 16 confirms that they all meet the structural integrity requirements of Steam Generator Integrity assessment guidelines, Revision 3. The minor loose parts wear and tube support plate wear do not challenge structural integrity limits. Since no degradation mechanisms challenging structural integrity limits were detected during the 1RE16 inspection and no primary-to-secondary leakage was observed prior to the end of Cycle 16 (EOC 16), the condition monitoring assessment requirements for SG operation are satisfied. With no indications of tube degradation, tube pulls and in-situ tests are not required. No challenges to the SG Performance Criteria were identified; therefore, the condition monitoring requirements for the Unit 1 RSG tube bundles at EOC 16 are satisfied. The next Unit 1 steam generator inspection is scheduled for refueling outage 1RE19.

IREI6 INSPECTION

SUMMARY

REPORT FOR STEAM GENERATOR TUBING of the SOUTH TEXAS PROJECT ELECTRIC GENERATING STATION UNIT I P.O. BOX 289 WADSWORTH, TEXAS 77483 Commercial Operation: August 25, 1988 Issue Date: September 13, 2011

1REI6 INSPECTION

SUMMARY

REPORT FOR STEAM GENERATOR TUBING of the SOUTH TEXAS PROJECT ELECTRIC GENERATING STATION UNIT 1 USNRC DOCKET NO.: 50-498 OPERATING LICENSE NO.: NPF-76 COMMERCIAL OPERATION DATE: August 25, 1988 Prepared By:

D. A. Stuhier -- - -

/~,,

Date D. A. Stuhler Date Test Engin r Approved By:

L6-'.,piess Date Stu$rvisor, Test Engineering

Attachment NOC-AE-1 1002722 Page 1 of 10 SOUTH TEXAS PROJECT UNIT 1 1REI6 INSPECTION

SUMMARY

REPORT FOR STEAM GENERATOR TUBING Introduction This summary report describes the inspection of steam generator tubing at South Texas Project (STP) Unit 1 performed during refueling outage 1RE16 in April 2011. Eddy current inspection, sludge lancing, and Foreign Object Search and Retrieval (FOSAR) were conducted in steam generators (SG) 1A, 18, 1C, and 1D. Due to previous operating experience related to loose parts, a more aggressive inspection scope was developed for SG 1D. Additional inspections of the secondary side of SG 1A and 1B were also performed.

The eddy current inspection performed during 1RE16 completed the first interval inspection requirements for all Unit 1 steam generators. The outage was performed following 118.83 effective full power months cumulative service with the Delta 94 replacement steam generators.

This report provides the information required by Technical Specification 6.8.3.o for maintaining steam generator tube integrity and the reporting requirements of Technical Specification 6.9.1.7.

Scope of Examination The Inspection Plan, "1RE16 Steam Generator In-Service Inspection Outage Plan April 2011,"

identified the steam generator tube areas to be examined by eddy current testing and the related procedures to be used during the inservice inspection. A Degradation Assessment written prior to the outage established the following scope of primary and secondary side inspections:

Primary Side Inspection Scope

  • Full length Bobbin inspection of the outer three peripheral tubes from tube end to tube end, including 10 tubes inwards into the no-tube lane from the periphery.

0 50% Full length bobbin inspection of all tubes. Scope includes all remaining tubes not inspected full length during 1RE13.

  • 20% +Point inspection of the upper tube support plate (TSP) hot leg (HL) to upper TSP cold leg (CL) on Rows 1 and 2 (u-bend).
  • +Point inspection of outer three tubes of periphery and divider lane top-of-tubesheet (TTS) +6 inches/-3 inches to aid in loose part detection (HL and CL).
  • 20% Sample +Point inspection of tubesheet-hot (TSH) +6 inches/-3 inches.
  • >20% Sample +Point inspection of TSH +6 inches/-16 inches in tubes with bulges and overexpansions. Of 95 anomalies inspected, 65 are in SG 1A, 18 in SG 1B, five in SG 1C, and seven in SG 1D.

0 +Point inspection of all previously identified dents and dings >5 volts.

  • +Point inspection of all prior and 1RE16 "I-code" and/or non-quantifiable indications as determined by bobbin inspection or any previously reported signal that has changed.

Attachment NOC-AE-1 1002722 Page 2 of 10

  • +Point inspection of potential loose parts in the eddy current database as identified by previous eddy current inspections.
  • +Point inspection of all observed loose parts as identified by previous secondary side video inspections and not removed.
  • +Point inspection of a minimum two tube locations surrounding any new potential loose part or foreign object identified in 1RE16.

" Video inspection of all installed plugs.

Secondary Side Inspection Scope

" TTS FOSAR in all four SGs including annulus and tube lane.

, TTS In-bundle FOSAR as follows:

o SG 1A inspect every fourth column both HL and CL beginning with Column 1.

o SG 1B inspect every fourth column both HL and CL beginning with Column 2.

o SG 1C inspect every fourth column both HL and CL beginning with Column 3.

o SG 1D inspect every second column both HL and CL beginning with Column 1.

" Ultra sludge lancing on all four steam generators.

  • Sludge collector inspection and cleaning (if required based on inspection) in SG 1A.

Sludge collectors to be cleaned if more than 0.5 inch of sludge is observed.

  • Steam drum inspection in SG 1A and lB.
  • Upper steam drum inspection of SG 1A.
  • Video probe inspection of ninth support plate on SG 1A.

" FOSAR of all loose parts left in service during 1RE13 (SG 1A, 1B, and 1C) and 1RE14 (SG 1 D), if reachable by tooling.

  • FOSAR of all potential loose parts identified by eddy current inspection, where possible.

Examination Results Table 1 provides a summary of the 1RE16 eddy current indications reported, while Tables 2A-D show the indication distribution. Table 3 and Table 4 provide details of the potential loose part (PLP) calls and reported volumetric (VOL) calls, respectively.

No tube corrosion or wear indications related to Anti-Vibration Bars were reported during the 1RE16 inspections. A few benign signals were observed, including dings/dents (DNG/DNT),

manufacturing burnish marks (MBM), and signals cleared as free from degradation (NQS) by motorized rotating pancake coil (MRPC) (+Point) examination. Signals representative of tube diameter increases (bulges- BLG) were also reported from the bobbin inspection analyses.

Benign signals in the 1RE16 inspection data were assessed by reviewing the prior available inspection data. If the historical lookup did not support the classification as a pre-existing benign signal or the signal exhibited a significant change, they were resolved by MRPC inspection. All identified benign signals are to be inspected in future outages as required by EPRI guidelines.

Attachment NOC-AE-1 1002722 Page 3 of 10

+Point sample inspection of previously reported tubesheet anomalies based on proximity to the expansion transition was performed. 95 anomalies (65 in SG 1A, 18 in SG 1B, five in SG 1C, and seven in SG 1D) were inspected. No degradation was found. This inspection will be the basis for potential future +Point programs should it become necessary in future outages to inspect such locations for primary water stress corrosion cracking (PWSCC), currently regarded as a non-relevant damage mechanism in the Unit 1 replacement steam generators (RSG) due to the Alloy 690TT tubes' resistance to PWSCC.

As noted in Table 3, a total of 104 PLP calls were reported in 1RE16. As required by EPRI guidelines, coordination between the eddy current and secondary visual inspection results was maintained. For those PLP locations where secondary access was available, tube locations showing PLP signals by eddy current were visually inspected to identify the source of the signal.

In addition, all TTS tube locations where foreign objects were identified during visual inspections were included in the TTS +Point inspection program. As seen in Table 3, no PLP calls were reported in SG 1A, three calls were reported in SG 1B, six calls were reported in SG lC, and 95 calls were reported in SG 1 D. No tube wear was reported associated with any of the PLP calls.

All new PLP calls were "boxed-in" by additional eddy current inspections. Disposition of legacy PLP calls was based on reviewing historical and 1RE16 eddy current data for PLP signals and wear.

Table 4 lists the thirteen reported VOL calls with their through-wall depths. Seven locations in SG 1D were legacy TTS wear. The foreign objects causing the wear were removed during previous inspections and no change in the wear signals was noted. The remaining six VOL calls are new indications. Three of the new VOL calls reported in SG 1C (Ri12C48 CL, RI1 0C48 CL, and Ri 11 C47 CL) were caused by a weld slag remnant which has since been removed. Through-wall wear depths were 6%, 9%, and 9%, respectively. In addition to the TTS wear noted, three TSP locations in SG 1A (R126C88 6th TSP HL) and SG 1B (R10C50 9th TSP CL and R3C155 6th TSP HL) exhibited low level wear. The low level wear indications correspond with the trefoil land contact and are slightly inward from the edge. The cause of the wear is most likely related to a small manufacturing burr at one of the trefoil lands.

Within the noise of the bobbin data is a very small signal measuring approximately 4%. The signals are very much like the residual on each edge of the TSP. For the 1RE16 inspection, the overall noise was less, the mix residual a little less, and the signal was therefore more defined from its surroundings. Wear at TSP is considered a "potential degradation mechanism" for the RSG's within the 1RE16 Degradation Assessment.

The level of TSP wear observed during 1RE16 will not have an impact on future SG inspection scope, nor limit the planned three cycles of operation prior to the 1RE19 outage. No wear due to stabilizer wire or corrosion-induced degradation was observed. Site-specific eddy current detection and sizing techniques qualified in accordance with EPRI non-destructive examination guidelines were used to perform the analyses. All VOL indications were evaluated against the in situ screening criteria. No burst or leak testing was required, and no tubes were removed from service.

PLP calls resolved via secondary side visual inspection where access allowed are listed in Table 5.

Attachment NOC-AE-1 1002722 Page 4 of 10 Table I - Summary of Eddy Current Indications Reported During IREI6 Deposit Signal 0 2 0 0 Free Span Dings 384 15 292 144 Distorted Dent/ Ding Indication Not 21 4 18 17 Confirmed 21_4 18_1 Dents ( at supports and baffles) 2 0 18 0 Distorted TS Indication Cleared 0 1 1 0 Indication Not Found 0 3 2 104 Distorted Support Signal 1 0 1 3 Indication Not Reported 125 18 56 119 Manufacturing Burnish Mark 142 126 142 155 No Detectable Degradation 7845 8275 8108 8176 Degradation Not Found 325 53 38 9 Non-Quantifiable Signal 29 34 26 28 Previous Rotating Call 3 2 0 5 Previous Bobbin Call 3 2 3 5 Potential Loose Part 0 3 6 95 Percent 1 1 0 0 Retest Bad Data 126 40 148 27 Retest Incomplete 6 10 11 2 Retest Due to Tube Restriction 0 2 10 0 Retest Due No Data 0 0 2 0 Volumetric 1 2 3 7 Note 1 Note' Legacy wear indications

Attachment NOC-AE-1 1002722 Page 5 of 10 Table 2A- 1RE16 Indication Distribution Report for Steam Generator 1A

  • ~DNG 1 192 1 1 --

- 10 --

1 36 3 1 2 1 - -

!tBM 1 10 9 9 5 6 5 1 9 9 1 1 3

- 95 - - - - - - - - - - - - - - - - - - - 7 -

1 5 - - - - - - - -

PE, -- -

Attachment NOC-AE-1 1002722 Page 6 of 10 Table 2B - 1RE16 Indication Distribution Report for Steam Generator 1B

Attachment NOC-AE-1 1002722 Page 7 of 10 Table 2C - 1 REI 6 Indication Distribution Report for Steam Generator IC

~Code< 1.TEH :TH F 3HH0I 5H 7 ~V0

-- -- 1 - - -

-DN _ 18 I-"- - 2 1 4 1 2 1 - 111 1 M8Mý31- 7 1 - 7 3 5 3 9 3 5 7 - 3 8 k[)F 1 2 2 - - - - - I - 19 - -

s I 1 - 1 - - - 1 2 1 3 2 P__ 6 - - -

- rB 6 1 -

C)NF 4r 10 b3 7 10-- C 4 01 8-291 I P 2 - 8 T i Brj - 130 - 42 - 90e 6 # "-- iO2 V D9 14 2 - 11 -

I N - - -

NR 1 16 1 1 1 6 2 2 1 - - -

MBM 2 - 8 - 8 - 12 - 10 10 T 1 4 3 - 6 1 NDPe - 9 - -4 - - - -

Attachment NOC-AE-1 1002722 Page 8 of 10 Table 2D - IRE16 Indication Distribution Report for Steam Generator ID C~d TH

', TS , 77B-' 0. 02H, 6.~3H 0,411~L dsfH OiH ~ 07H 08H ~ Ati{ ~ V D S- -- -- - - - - -

DTs - - -

WN 9 5 16 6 4 INR 2 12 2 4 - 2 2 3 - 2 - 1 - 7 1 2 - 5 1 4 2 7 5 9 1 4 - 4 - 4 - 14 - 10 - 6 7 N13F1 6 - 2 - - -

~NOS2 - - - - - - - - 2 - - 3 - 3 3 - -

P  ! - -

FL 4 2 60 2 10

  • i4 - - - - -
  • 3 - - - --
    • 6 - - 5 - 5 - - - 1 - - - -- - - - - - -

- - -. ...- 1 - 24 14 25 -

1 11 1 27 3 5 1 5 1 - 14 2 2 -

£qBM* 1 - 14 - 10 - 4 11 8 - 11 - 10 - 6 - 1 - 2 - -

N S - - 3 - 2 - - - 1 - - 2 1 3 - - 3 - -

- - - -.. - - - - - - - - 3 14 - - -

4- -,- -- - -

N 1 3 - 94 - - 29

Attachment NOC-AE-1 1002722 Page 9 of 10 Table 3 - Summary of IREI6 Potential Loose Part Calls Table 4- Summary of IREI6 Volumetric Calls R126C88 HL 6m TSP 6 Low level signal noted in 1RE12 R3C155 HL 6*TSP 9 Luo level signal noted in 1REI2 R10C5O CL 9TSP 9 RI12C48 CL TTS 34 RI 10C48 CL TTS 19 1 RE1 6 Identified Weld slag - weld slag removed RllIC47 CL TTS 13 R70C140 HL TTS 9 R84C22 HL TTS 21 R84C24 HL TTS 5 R2C138 CL TTS 8 7- Legacy Calls R2C138 CL TTS 9 RI16C48 CL TTS 18 R99C35 CL TTS 8

Attachment NOC-AE-1 1002722 Page 10 of 10 Table 5 - 1RE1 6 Top of Tubesheet Potential Loose Part Visual Inspection Results 11G Row um ~LEg, Elevfi6~n-: , Colmmý eint~

  • .4 PLP-B-o01 88 58 HL ITS +0.16' Legacy object from 1RE14 - object not removed PLP-B-002 87 59 HL TFS+.11" Legacy object from 1RE14 -object not removed PLP-B-003 75 69 HL TTS+0.26" Legacy PLP call from 1REl3 PLP-C-001 104 38 HL TTS+0.05"
  • PLP-C-002 103 39 HL TTS+0.15" FOSAR Object IC015 - Object retrieved c PLP-C-003 87 121 HL T-TS+0.01" PLP-C-004 89 121 HL TTS+0.28' FOSAR Object IC016 - Object retrieved PLP-C-005 90 122 H-L TTS+0.18" SPLIP-C-006 88 122 HL TTS+0.16"

. PLP-D-006 81 25 HL TTS+o.02 FOSAR object 1D073 or 11D074 - object not removed PLP-D-034 121 69 HL TTS+0.06 FOSAR Object 1D038- object not removed D PLP-D-037 86 84 HL: TTS +2.150 Nothing seen PLP-D-052 118 104 HL TTS+0.04 Sludge rock - object not removed PLP-D-057 57 113 HL HS+002 Sludge rock 1D006 -legacy seen in 1RE14- object not

_ _ _ _ _ _ _ _removed Plug Inspection Results All installed plugs were visually examined. No anomalies were noted.

Tube Plugging The total number of tubes plugged per steam generator to date is as follows:

Steam Generator 1A 33 0.44%

Steam Generator 1 B 40 0.53%

Steam Generator 1C 26 0.34%

Steam Generator 1 D 13 0.17%

No tubes were plugged during 1RE16.

Condition Monitoring Conclusion Based on the Condition Monitoring evaluation, inservice inspection of tubes in service during Cycle 16 confirms that they all meet the structural integrity requirements of Steam Generator Integrity assessment guidelines, Revision 3. The minor loose parts wear and tube support plate wear do not challenge structural integrity limits. Since no degradation mechanisms challenging structural integrity limits were detected during the 1RE16 inspection and no primary-to-secondary leakage was observed prior to the end of Cycle 16 (EOC 16), the condition monitoring assessment requirements for SG operation are satisfied. With no indications of tube degradation, tube pulls and in-situ tests are not required. No challenges to the SG Performance Criteria were identified; therefore, the condition monitoring requirements for the Unit 1 RSG tube bundles at EOC 16 are satisfied. The next Unit 1 steam generator inspection is scheduled for refueling outage 1RE19.

1REI6 INSPECTION

SUMMARY

REPORT FOR STEAM GENERATOR TUBING of the SOUTH TEXAS PROJECT ELECTRIC GENERATING STATION UNIT I P.O. BOX 289 WADSWORTH, TEXAS 77483 Commercial Operation: August 25, 1988 Issue Date: September 13, 2011

IRE16 INSPECTION

SUMMARY

REPORT FOR STEAM GENERATOR TUBING of the SOUTH TEXAS PROJECT ELECTRIC GENERATING STATION UNIT I USNRC DOCKET NO.: 50-498 OPERATING LICENSE NO.: NPF-76 COMMERCIAL OPERATION DATE: August 25, 1988 Prepared By:

D. -*A.

ule ..

D. A. Stuhler 3V-?6.

Date.

Date Test Engin r Approved By:

Date 50ervisor, Test Engineering

Attachment NOC-AE-1 1002722 Page 1 of 10 SOUTH TEXAS PROJECT UNIT I IRE16 INSPECTION

SUMMARY

REPORT FOR STEAM GENERATOR TUBING Introduction This summary report describes the inspection of steam generator tubing at South Texas Project (STP) Unit 1 performed during refueling outage 1RE1 6 in April 2011. Eddy current inspection, sludge lancing, and Foreign Object Search and Retrieval (FOSAR) were conducted in steam generators (SG) 1A, 1B, 1C, and 1D. Due to previous operating experience related to loose parts, a more aggressive inspection scope was developed for SG 1D. Additional inspections of the secondary side of SG 1A and 1B were also performed.

The eddy current inspection performed during 1RE16 completed the first interval inspection requirements for all Unit 1 steam generators. The outage was performed following 118.83 effective full power months cumulative service with the Delta 94 replacement steam generators.

This report provides the information required by Technical Specification 6.8.3.0 for maintaining steam generator tube integrity and the reporting requirements of Technical Specification 6.9.1.7.

Scope of Examination The Inspection Plan, "1RE1 6 Steam Generator In-Service Inspection Outage Plan April 2011,"

identified the steam generator tube areas to be examined by eddy current testing and the related procedures to be used during the inservice inspection. A Degradation Assessment written prior to the outage established the following scope of primary and secondary side inspections:

Primary Side Inspection Scope

  • Full length Bobbin inspection of the outer three peripheral tubes from tube end to tube end, including 10 tubes inwards into the no-tube lane from the periphery.
  • 50% Full length bobbin inspection of all tubes. Scope includes all remaining tubes not inspected full length during 1RE1 3.

0 20% +Point inspection of the upper tube support plate (TSP) hot leg (HL) to upper TSP cold leg (CL) on Rows 1 and 2 (u-bend).

  • +Point inspection of outer three tubes of periphery and divider lane top-of-tubesheet (TTS) +6 inches/-3 inches to aid in loose part detection (HL and CL).
  • 20% Sample +Point inspection of tubesheet-hot (TSH) +6 inches/-3 inches.

0 >20% Sample +Point inspection of TSH +6 inches/-16 inches in tubes with bulges and overexpansions. Of 95 anomalies inspected, 65 are in SG 1A, 18 in SG 1B, five in SG 1C, and seven in SG 1D.

0 +Point inspection of all previously identified dents and dings >5 volts.

  • +Point inspection of all prior and 1RE16 "I-code" and/or non-quantifiable indications as determined by bobbin inspection or any previously reported signal that has changed.

Attachment NOC-AE-1 1002722 Page 2 of 10

  • +Point inspection of potential loose parts in the eddy current database as identified by previous eddy current inspections.

" +Point inspection of all observed loose parts as identified by previous secondary side video inspections and not removed.

  • +Point inspection of a minimum two tube locations surrounding any new potential loose part or foreign object identified in 1RE16.
  • Video inspection of all installed plugs.

Secondary Side Inspection Scope

" TTS FOSAR in all four SGs including annulus and tube lane.

" TTS In-bundle FOSAR as follows:

o SG 1A inspect every fourth column both HL and CL beginning with Column 1.

o SG 1B inspect every fourth column both HL and CL beginning with Column 2.

o SG 1C inspect every fourth column both HL and CL beginning with Column 3.

o SG 1D inspect every second column both HL and CL beginning with Column 1.

  • Sludge collector inspection and cleaning (if required based on inspection) in SG 1A.

Sludge collectors to be cleaned if more than 0.5 inch of sludge is observed.

" Steam drum inspection in SG 1A and lB.

  • Upper steam drum inspection of SG 1A.
  • Video probe inspection of ninth support plate on SG 1A.

" FOSAR of all loose parts left in service during 1RE13 (SG 1A, 1B, and 1C) and 1RE14 (SG 1 D), if reachable by tooling.

  • FOSAR of all potential loose parts identified by eddy current inspection, where possible.

Examination Results Table 1 provides a summary of the 1RE1 6 eddy current indications reported, while Tables 2A-D show the indication distribution. Table 3 and Table 4 provide details of the potential loose part (PLP) calls and reported volumetric (VOL) calls, respectively.

No tube corrosion or wear indications related to Anti-Vibration Bars were reported during the 1RE16 inspections. A few benign signals were observed, including dings/dents (DNG/DNT),

manufacturing burnish marks (MBM), and signals cleared as free from degradation (NQS) by motorized rotating pancake coil (MRPC) (+Point) examination. Signals representative of tube diameter increases (bulges- BLG) were also reported from the bobbin inspection analyses.

Benign signals in the 1RE16 inspection data were assessed by reviewing the prior available inspection data. If the historical lookup did not support the classification as a pre-existing benign signal or the signal exhibited a significant change, they were resolved by MRPC inspection. All identified benign signals are to be inspected in future outages as required by EPRI guidelines.

Attachment NOC-AE-1 1002722 Page 3 of 10

+Point sample inspection of previously reported tubesheet anomalies based on proximity to the expansion transition was performed. 95 anomalies (65 in SG 1A, 18 in SG 1B, five in SG 1C, and seven in SG 1D) were inspected. No degradation was found. This inspection will be the basis for potential future +Point programs should it become necessary in future outages to inspect such locations for primary water stress corrosion cracking (PWSCC), currently regarded as a non-relevant damage mechanism in the Unit 1 replacement steam generators (RSG) due to the Alloy 690TT tubes' resistance to PWSCC.

As noted in Table 3, a total of 104 PLP calls were reported in 1RE16. As required by EPRI guidelines, coordination between the eddy current and secondary visual inspection results was maintained. For those PLP locations where secondary access was available, tube locations showing PLP signals by eddy current were visually inspected to identify the source of the signal.

In addition, all TTS tube locations where foreign objects were identified during visual inspections were included in the TTS +Point inspection program. As seen in Table 3, no PLP calls were reported in SG 1A, three calls were reported in SG 1B, six calls were reported in SG 1C, and 95 calls were reported in SG 1D. No tube wear was reported associated with any of the PLP calls.

All new PLP calls were "boxed-in" by additional eddy current inspections. Disposition of legacy PLP calls was based on reviewing historical and 1RE16 eddy current data for PLP signals and wear.

Table 4 lists the thirteen reported VOL calls with their through-wall depths. Seven locations in SG 1 D were legacy TTS wear. The foreign objects causing the wear were removed during previous inspections and no change in the wear signals was noted. The remaining six VOL calls are new indications. Three of the new VOL calls reported in SG 1C (Ri12C48 CL, R110C48 CL, and R111C47 CL) were caused by a weld slag remnant which has since been removed. Through-wall wear depths were 6%, 9%, and 9%, respectively. In addition to the TTS wear noted, three TSP locations in SG 1A (R1 26C88 6th TSP HL) and SG 1B (R1 0C50 9th TSP CL and R3C155 6th TSP HL) exhibited low level wear. The low level wear indications correspond with the trefoil land contact and are slightly inward from the edge. The cause of the wear is most likely related to a small manufacturing burr at one of the trefoil lands.

Within the noise of the bobbin data is a very small signal measuring approximately 4%. The signals are very much like the residual on each edge of the TSP. For the 1RE16 inspection, the overall noise was less, the mix residual a little less, and the signal was therefore more defined from its surroundings. Wear at TSP is considered a "potential degradation mechanism" for the RSG's within the 1RE16 Degradation Assessment.

The level of TSP wear observed during 1 RE1 6 will not have an impact on future SG inspection scope, nor limit the planned three cycles of operation prior to the 1RE19 outage. No wear due to stabilizer wire or corrosion-induced degradation was observed. Site-specific eddy current detection and sizing techniques qualified in accordance with EPRI non-destructive examination guidelines were used to perform the analyses. All VOL indications were evaluated against the in situ screening criteria. No burst or leak testing was required, and no tubes were removed from service.

PLP calls resolved via secondary side visual inspection where access allowed are listed in Table 5.

Attachment NOC-AE-1 1002722 Page 4 of 10 Table I - Summary of Eddy Current Indications Reported During IREI6 Deposit Signal 0 2 0 0 Free Span Dings 384 15 292 144 Distorted Dent/ Ding Indication Not 21 4 18 17 Confirmed Dents ( at supports and baffles) 2 0 18 0 Distorted TS Indication Cleared 0 1 1 0 Indication Not Found 0 3 2 104 Distorted Support Signal 1 0 1 3 Indication Not Reported 125 18 56 119 Manufacturing Burnish Mark 142 126 142 155 No Detectable Degradation 7845 8275 8108 8176 Degradation Not Found 325 53 38 9 Non-Quantifiable Signal 29 34 26 28 Previous Rotating Call 3 2 0 5 Previous Bobbin Call 3 2 3 5 Potential Loose Part 0 3 6 95 Percent 1 1 0 0 Retest Bad Data 126 40 148 27 Retest Incomplete 6 10 11 2 Retest Due to Tube Restriction 0 2 10 0 Retest Due No Data 0 0 2 0 Volumetric 1 2 3 7 Note 1 Notel Legacy wear indications

Attachment NOC-AE-1 1002722 Page 5 of 10 Table 2A - IRE16 Indication Distribution Report for Steam Generator 1A

Attachment NOC-AE-1 1002722 Page 6 of 10 Table 2B - IREI6 Indication Distribution Report for Steam Generator lB INR2 -6 - 2 7 2 MBKM, 2 1 9 - 20 - 8 - 4 - 6 4 - 2 - 7 - 2 - - - - -

-- - - - - - - - - 4 - -- - 3 23

~N~ S- 3 1 2 -- 2 - I - - 4 - -

'PC' T

Attachment NOC-AE-1 1002722 Page 7 of 10 Table 2C - IRE16 Indication Distribution Report for Steam Generator IC G 130 42 90 - --

ON 14 2 - 1 - -

T 1O

- - -° - --

1 16 1 1 1 6 2 1 2 1 1 2

2BM - 8 - 8 - 12 9 10 10 - 7 1 4 3 6 1 -

,N -F 9 - - - 4 - -

S - - 2 - 2 2 1 - 1 1 - -

R, T - 2-- ---

R 8 - - 2 - - - - -

ULC- - -

Attachment NOC-AE-1 1002722 Page 8 of 10 Table 2D - IREI6 Indication Distribution Report for Steam Generator ID

9 Attachment NOC-AE-1 1002722 Page 9 of 10 Table 3 - Summary of IREI6 Potential Loose Part Calls j(Lit.i U U U 'U U

.REIG: :0 0 0 " 0 0 1RE13 .6-,

1RE16  :-3 . .. . '00 1RE13ý

    • i:6:*

..* 6, o- . ... :o : o... ..

I ""

6 . 0 0 . 0.

0.

!REI4:: 0 24 9 67 18  :

1RE61 :6ý 0 ~ 62 1100, Table 4 - Summary of I REIS6 Volumetric Calls Ti fft 6 iVd fiwj IIý!,

Ixýp ttf, p/o) I CC; R126C88 HL 6 MTSP 6 Low level signal noted in 1RE12 R3C155 HL 6*TSP 9 Low level signal noted in IRE12 R10C50 CL 9TSP 9 Ri 12C48 CL TTS 34 R110C48 CL TTS 19 1 RE16 Identified Weld slag -weld slag removed R II1C47 CL TTS 13 R70C140 HL TTS 9 R84C22 HL TTS 21 R84C24 HL TTS 5 R2C1 38 CL TTS 8 7- Legacy Calls R2C138 CL TTS 9 RI16C48 CL TTS 18 R99C35 CL TTS 8

Attachment NOC-AE-1 1002722 Page 10 of 10 Table 5 - 1 RE1 6 Top of Tubesheet Potential Loose Part Visual Inspection Results PLP-B-001 88 58 HL TrS +0.16' Legacy object from 1REI4 - object not removed PLP-6-002 87 59 HL TTS*0.1 1" Legacy object from IREI4 - object not removed PLP-B-003 75 69 HL TTS+0.26' Legacy PLP call from 1RE13 PLP-C-001 104 38 HL TTS+0.05" FOSAR Object 1CO15 - Object retrieved PLP-C-002 103 39 HL TTS+0.18' PLP-C-003 87 121 HL TTS+0.01t PLP-C-004 89 121 HL TrS+0.28' FOSAR Object 1C016 - Object retrieved PLP-C-005 90 122 HL rTS+0.18" PLP-C-006 88 122 HL TTS+0.16" PLP-D-006 81 25 HL TTS+0H02 FOSAR object 1D073 or 1D074 -object not removed PLP-0-034 121 69 HL TTS+0.06 FOSAR Object 10039 - object not removed PLP-D-037 86 84 HL: TTS +2.150 Nothing seen PLP-D-052 118 104 HL TTS+004 Sludge rock - object not removed PLP-D-057 57 113 HL TTS+0_02 Sludge rock 10006 - legacy seen in 1RE14 - object not I I_ I removed Plug Inspection Results All installed plugs were visually examined. No anomalies were noted.

Tube Plugging The total number of tubes plugged per steam generator to date is as follows:

Steam Generator 1A 33 0.44%

Steam Generator 1 B 40 0.53%

Steam Generator 1C 26 0.34%

Steam Generator 1 D 13 0.17%

No tubes were plugged during 1RE16.

Condition Monitoring Conclusion Based on the Condition Monitoring evaluation, inservice inspection of tubes in service during Cycle 16 confirms that they all meet the structural integrity requirements of Steam Generator Integrity assessment guidelines, Revision 3. The minor loose parts wear and tube support plate wear do not challenge structural integrity limits. Since no degradation mechanisms challenging structural integrity limits were detected during the 1RE16 inspection and no primary-to-secondary leakage was observed prior to the end of Cycle 16 (EOC 16), the condition monitoring assessment requirements for SG operation are satisfied. With no indications of tube degradation, tube pulls and in-situ tests are not required. No challenges to the SG Performance Criteria were identified; therefore, the condition monitoring requirements for the Unit 1 RSG tube bundles at EOC 16 are satisfied. The next Unit 1 steam generator inspection is scheduled for refueling outage 1 RE19.

IREI6 INSPECTION

SUMMARY

REPORT FOR STEAM GENERATOR TUBING of the SOUTH TEXAS PROJECT ELECTRIC GENERATING STATION UNIT I P.O. BOX 289 WADSWORTH, TEXAS 77483 Commercial Operation: August 25, 1988 Issue Date: September 13, 2011

IRE16 INSPECTION

SUMMARY

REPORT FOR STEAM GENERATOR TUBING of the SOUTH TEXAS PROJECT ELECTRIC GENERATING STATION UNIT I USNRC DOCKET NO.: 50-498 OPERATING LICENSE NO.: NPF-76 COMMERCIAL OPERATION DATE: August 25,1988 Prepared By: ,e/ Date Date

//

D. A. Stuhler Approved By:

Test Engineering

Attachment NOC-AE-1 1002722 Page 1 of 10 SOUTH TEXAS PROJECT UNIT I I RE16 INSPECTION

SUMMARY

REPORT FOR STEAM GENERATOR TUBING Introduction This summary report describes the inspection of steam generator tubing at South Texas Project (STP) Unit 1 performed during refueling outage 1 RE1 6 in April 2011. Eddy current inspection, sludge lancing, and Foreign Object Search and Retrieval (FOSAR) were conducted in steam generators (SG) 1A, 1B, 1C, and 1D. Due to previous operating experience related to loose parts, a more aggressive inspection scope was developed for SG 1 D. Additional inspections of the secondary side of SG 1A and 1B were also performed.

The eddy current inspection performed during 1RE16 completed the first interval inspection requirements for all Unit 1 steam generators. The outage was performed following 118.83 effective full power months cumulative service with the Delta 94 replacement steam generators.

This report provides the information required by Technical Specification 6.8.3.o for maintaining steam generator tube integrity and the reporting requirements of Technical Specification 6.9.1.7.

Scope of Examination The Inspection Plan, "1RE16 Steam Generator In-Service Inspection Outage Plan April 2011,"

identified the steam generator tube areas to be examined by eddy current testing and the related procedures to be used during the inservice inspection. A Degradation Assessment written prior to the outage established the following scope of primary and secondary side inspections:

Primary Side Inspection Scope

  • Full length Bobbin inspection of the outer three peripheral tubes from tube end to tube end, including 10 tubes inwards into the no-tube lane from the periphery.
  • 50% Full length bobbin inspection of all tubes. Scope includes all remaining tubes not inspected full length during 1RE13.
  • 20% +Point inspection of the upper tube support plate (TSP) hot leg (HL) to upper TSP cold leg (CL) on Rows 1 and 2 (u-bend).
  • +Point inspection of outer three tubes of periphery and divider lane top-of-tubesheet (TTS) +6 inches/-3 inches to aid in loose part detection (HL and CL).
  • 20% Sample +Point inspection of tubesheet-hot (TSH) +6 inches/-3 inches.
  • >20% Sample +Point inspection of TSH +6 inches/-16 inches in tubes with bulges and overexpansions. Of 95 anomalies inspected, 65 are in SG 1A, 18 in SG 1 B, five in SG 1C, and seven in SG 1D.

0 +Point inspection of all previously identified dents and dings >5 volts.

  • +Point inspection of all prior and 1RE16 "I-code" and/or non-quantifiable indications as determined by bobbin inspection or any previously reported signal that has changed.

Attachment NOC-AE-1 1002722 Page 2 of 10

" +Point inspection of potential loose parts in the eddy current database as identified by previous eddy current inspections.

" +Point inspection of all observed loose parts as identified by previous secondary side video inspections and not removed.

  • +Point inspection of a minimum two tube locations surrounding any new potential loose part or foreign object identified in 1 RE1 6.
  • Video inspection of all installed plugs.

Secondary Side Inspection Scope

" TTS FOSAR in all four SGs including annulus and tube lane.

  • TTS In-bundle FOSAR as follows:

o SG 1A inspect every fourth column both HL and CL beginning with Column 1.

o SG 1B inspect every fourth column both HL and CL beginning with Column 2.

o SG IC inspect every fourth column both HL and CL beginning with Column 3.

o SG 1D inspect every second column both HL and CL beginning with Column 1.

" Ultra sludge lancing on all four steam generators.

  • Sludge collector inspection and cleaning (if required based on inspection) in SG 1A.

Sludge collectors to be cleaned if more than 0.5 inch of sludge is observed.

  • Steam drum inspection in SG 1A and 1B.
  • Upper steam drum inspection of SG 1A.

" Video probe inspection of ninth support plate on SG 1A.

" FOSAR of all loose parts left in service during 1RE13 (SG 1A, 1B, and 1C) and 1RE14 (SG 1 D), if reachable by tooling.

  • FOSAR of all potential loose parts identified by eddy current inspection, where possible.

Examination Results Table 1 provides a summary of the 1 RE1 6 eddy current indications reported, while Tables 2A-D show the indication distribution. Table 3 and Table 4 provide details of the potential loose part (PLP) calls and reported volumetric (VOL) calls, respectively.

No tube corrosion or wear indications related to Anti-Vibration Bars were reported during the 1RE16 inspections. A few benign signals were observed, including dings/dents (DNG/DNT),

manufacturing burnish marks (MBM), and signals cleared as free from degradation (NQS) by motorized rotating pancake coil (MRPC) (+Point) examination. Signals representative of tube diameter increases (bulges- BLG) were also reported from the bobbin inspection analyses.

Benign signals in the 1RE16 inspection data were assessed by reviewing the prior available inspection data. If the historical lookup did not support the classification as a pre-existing benign signal or the signal exhibited a significant change, they were resolved by MRPC inspection. All identified benign signals are to be inspected in future outages as required by EPRI guidelines.

Attachment NOC-AE-1 1002722 Page 3 of 10

+Point sample inspection of previously reported tubesheet anomalies based on proximity to the expansion transition was performed. 95 anomalies (65 in SG 1A, 18 in SG 1B, five in SG 1C, and seven in SG 1 D) were inspected. No degradation was found. This inspection will be the basis for potential future +Point programs should it become necessary in future outages to inspect such locations for primary water stress corrosion cracking (PWSCC), currently regarded as a non-relevant damage mechanism in the Unit 1 replacement steam generators (RSG) due to the Alloy 690TT tubes' resistance to PWSCC.

As noted in Table 3, a total of 104 PLP calls were reported in 1RE16. As required by EPRI guidelines, coordination between the eddy current and secondary visual inspection results was maintained. For those PLP locations where secondary access was available, tube locations showing PLP signals by eddy current were visually inspected to identify the source of the signal.

In addition, all TTS tube locations where foreign objects were identified during visual inspections were included in the TTS +Point inspection program. As seen in Table 3, no PLP calls were reported in SG 1A, three calls were reported in SG 1 B, six calls were reported in SG IC, and 95 calls were reported in SG 1D. No tube wear was reported associated with any of the PLP calls.

All new PLP calls were "boxed-in" by additional eddy current inspections. Disposition of legacy PLP calls was based on reviewing historical and 1 RE16 eddy current data for PLP signals and wear.

Table 4 lists the thirteen reported VOL calls with their through-wall depths. Seven locations in SG 1D were legacy TTS wear. The foreign objects causing the wear were removed during previous inspections and no change in the wear signals was noted. The remaining six VOL calls are new indications. Three of the new VOL calls reported in SG 1C (Rl12C48 CL, R110C48 CL, and R111C47 CL) were caused by a weld slag remnant which has since been removed. Through-wall wear depths were 6%, 9%, and 9%, respectively. In addition to the TTS wear noted, three TSP locations in SG 1A (R126C88 6th TSP HL) and SG 1B (R10C50 9th TSP CL and R3C155 6th TSP HL) exhibited low level wear. The low level wear indications correspond with the trefoil land contact and are slightly inward from the edge. The cause of the wear is most likely related to a small manufacturing burr at one of the trefoil lands.

Within the noise of the bobbin data is a very small signal measuring approximately 4%. The, signals are very much like the residual on each edge of the TSP. For the 1RE16 inspection, the overall noise was less, the mix residual a little less, and the signal was therefore more defined from its surroundings. Wear at TSP is considered a "potential degradation mechanism" for the RSG's within the 1RE16 Degradation Assessment.

The level of TSP wear observed during 1RE1 6 will not have an impact on future SG inspection scope, nor limit the planned three cycles of operation prior to the 1RE19 outage. No wear due to stabilizer wire or corrosion-induced degradation was observed. Site-specific eddy current detection and sizing techniques qualified in accordance with EPRI non-destructive examination guidelines were used to perform the analyses. All VOL indications were evaluated against the in situ screening criteria. No burst or leak testing was required, and no tubes were removed from service.

PLP calls resolved via secondary side visual inspection where access allowed are listed in Table 5.

Attachment NOC-AE-1 1002722 Page 4 of 10 Table I - Summary of Eddy Current Indications Reported During IREI6 Deposit Signal 0 2 0 0 Free Span Dings 384 15 292 144 Distorted Dent I Ding Indication Not 21 4 18 17 Confirmed Dents ( at supports and baffles) 2 0 18 0 Distorted TS Indication Cleared 0 1 1 0 Indication Not Found 0 3 2 104 Distorted Support Signal 1 0 1 3 Indication Not Reported 125 18 56 119 Manufacturing Burnish Mark 142 126 142 155 No Detectable Degradation 7845 8275 8108 8176 Degradation Not Found 325 53 38 9 Non-Quantifiable Signal 29 34 26 28 Previous Rotating Call 3 2 0 5 Previous Bobbin Call 3 2 3 5 Potential Loose Part 0 3 6 95 Percent 1 1 0 0 Retest Bad Data 126 40 148 27 Retest Incomplete 6 10 11 2 Retest Due to Tube Restriction 0 2 10 0 Retest Due No Data 0 0 2 0 Volumetric 1 2 3 Note1 Legacy wear indications

Attachment NOC-AE-1 1002722 Page 5 of 10 Table 2A- IRE16 Indication Distribution Report for Steam Generator 1A

~CdTEH~ * 'SH 3> 0I~~ = 51 16ýiP - 17 * ~ 9NAB IN - -1I-- 1 - 1 -1 180 2 2

,-.11- . . ...

- - - - - - - - - - - --- - - - - '- I

- - - I - 2 2 - 1 1 1 3 4 2 1 5 52 - 1

,MBM 3 4 1 7 7 - 9 3 4 3 19 1 4 7

- 5 160o - - - - 58 -

- - - - - - - 1 1 1 4 1 2 292 3 2

  • Cd4 w9,38Cb .-. C ~ : O~...-Z~ O -~

- ,cr* _ C 1 36 3 1 2 - I 1 - 1

  • [I*,* 1 - 10 - 9 9 5 6 5 1 9 9 1 1 3
  • !* - 95 -7

".-S 12 1 P - 12

ý.'LP

Attachment NOC-AE-1 1002722 Page 6 of 10 Table 2B - IREI6 Indication Distribution Report for Steam Generator lB

- - 1~- 11- 1 -2 5 MBS - - 2 - 4 4 3 5 6 10 5 - 10 2 7 L) 2- 19 5 1 2 2 1 3 P - - 1 1 2 - 4 D2- - , .

,.II 2 1 9 2 - 8 4 - 4 - 2-- 7 2

- -- - - 4 - - - - - 3 23 -

2 1 1 4

Attachment NOC-AE-1 1002722 Page 7 of 10 Table 2C - IREI6 Indication Distribution Report for Steam Generator IC 0 7~0C~ Y K06C 01CO5 MCJ TgSC '*IEC~

EN - 130 - 42 90 ... ..

P;F 14 2 - 1 - -

1 16 1 1 1 6 2 - 2 - - -

2 8 - - 12 9 10 10 7 1 4 3 6 1 - -

F 9 - 4 -

1 - 2 2 2 - - - - -

VC - - - -

Attachment NOC-AE-1 1002722 Page 8 of 10 Table 2D - IREI6 Indication Distribution Report for Steam Generator ID T < TSH PFB4Hý 1 1 02 5ý 0<4UI 6HWl -~0ý~ OR11 ~AV B Cc - _ ~o ~ >8 NF 5 16 6 4 -

N 2 - 12 2 4 - 2 2 3 - 2 1 - 7 1 2 - 5 1

- - - 4 - 2 7 5 - 9 1 4 - 4 - 4 - 14 - 10 - 6 7 1 6 2 1Q~ - - 2 - - - - - 2 - - - 3 - 3 - 3 - -

4 2 60 2 10

- 3 3)r - - - - 06 4 - - 114 T i DN 1 39 - 94 -

- - - - - ---- 1 24 14 25

-S 1 ... - - -. -...-

1R - 1 11 1 27 3 5 1 5 - I - - 14 2 2 114 - 10 - 4 - 1 8 - 11 - 10 6 - 1 - 2 -

NQ!3 2 - - - I - 2 1 3 - - 3 - - -

- - - - - - - 3 14 - - -

- - - -- - - - - - - - - - - - -2

Attachment NOC-AE-1 1002722 Page 9 of 10 Table 3 - Summary of IREI6 Potential Loose Part Calls Table 4 - Summary of IREI6 Volumetric Calls R126C88 HL6l inote TSP 6 Low level signa t R126C88 HL 6 MTSP 5 Low level signal noted in 1 RE12 R3C1 55 HL5e TSP 9 Low level signal noted in IRE12 RiOC5 CL 9" TSP 9 R112C48 CL TTS 34 R1IOC48 CL TTS 19 1RE16 Identified Weld slag - weld slag removed RI11C47 CL TTS 13 R70C140 HL TTS 9 R84C22 HL TTS 21 R84C24 HL TTS 5 R2C138 CL TTS 8 7- Legacy Calls R2C138 CL TTS 9 RI16C48 CL TTS 18 R99C35 CL TTS 8

Attachment NOC-AE-1 1002722 Page 10 of 10 Table 5 - 1RE1 6 Top of Tubesheet Potential Loose Part Visual Inspection Results D Rovi CFo11ifin L>'1 eg LIPD0rl Am- n PLP-B-001 88 58 HL TTS +0.16- Legacy object from IRE14 -object not removed B PLP-B-002 87 59 HL TTS+.0II" Legacy object from 1RE14 -object not removed PLP-B-003 75 69 AL TTS+0.26' Legacy PLP call from IRE13 P1P-0-001 104 38 HL TTS+O.05' FOSAR Object 1C015 - Object retrieved PLP-C-002 103 39 HL TTS+0. 18' PLP-C-003 87 121 HA TTS+0.01' PiP-C-004 89 121 HL TTS+0.28' FOSAR Object 1C016 - Object retrieved PLP-C-005 90 122 AL TTS+0A18" PLP-C-006 88 122 HA TTS+0.16' PLP-D-006 81 25 HL TTS+0.02 FOSAR object 1D073 or 1D074 - object not removed PiP-D-034 121 69 HA TTS+0.06 FOSAR Object 1D039- object not removed PLP-D-037 86 84 HL- TTS +2.150 Nothing seen PLP-D-052 118 104 H TTS+0.04 Sludge rock -object not removed PLP-0-057 57 113 HL TTS+0_02 Sludge rock 10006 -legacy seen in 1RE14 - object not removed Plug Inspection Results All installed plugs were visually examined. No anomalies were noted.

Tube Plugging The total number of tubes plugged per steam generator to date is as follows:

Steam Generator 1A 33 0.44%

Steam Generator 1 B 40 0.53%

Steam Generator 1C 26 0.34%

Steam Generator 1 D 13 0.17%

No tubes were plugged during 1RE16.

Condition Monitoring Conclusion Based on the Condition Monitoring evaluation, inservice inspection of tubes in service during Cycle 16 confirms that they all meet the structural integrity requirements of Steam Generator Integrity assessment guidelines, Revision 3. The minor loose parts wear and tube support plate wear do not challenge structural integrity limits. Since no degradation mechanisms challenging structural integrity limits were detected during the 1RE16 inspection and no primary-to-secondary leakage was observed prior to the end of Cycle 16 (EOC 16), the condition monitoring assessment requirements for SG operation are satisfied. With no indications of tube degradation, tube pulls and in-situ tests are not required. No challenges to the SG Performance Criteria were identified; therefore, the condition monitoring requirements for the Unit 1 RSG tube bundles at EOC 16 are satisfied. The next Unit 1 steam generator inspection is scheduled for refueling outage 1 RE19.

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