ULNRC-06332, Results of Steam Generator Tube In-Service Inspection

Results of Steam Generator Tube In-Service Inspection

ML16286A547
Person / Time
Site:	Callaway
Issue date:	10/11/2016
From:	Cox B Ameren Missouri, Union Electric Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
ULNRC-06332
Download: ML16286A547 (10)

Text

Ameren MISSOURI Callaway Plant October 11,2016 ULNRC-06332 U.S. Nuclear Regulatory Commission Affn: Document Control Desk Washington, DC 20555-0001 Ladies and Gentlemen:

DOCKET NUMBER 50-483 CALLAWAY PLANT UNIT I UNION ELECTRIC CO.

FACILITY OPERATING LICENSE NPF-30 RESULTS OF STEAM GENERATOR TUBE IN-SERVICE INSPECTION In accordance with Callaway Plant Technical Specification 5.6.10, the enclosed report provides the results of the most recent steam generator tube in-service inspection performed at Callaway Plant. This report documents that the steam generator tube integrity performance criteria have been met for operating cycles 19, 20, and 21, and also demonstrates that there is reasonable assurance that the performance criteria will be met for the upcoming 3-cycle operating period, consisting of cycles 22, 23, and 24.

This letter does not contain new commitments.

Sincerely, t

s Barry L. Cox, Senior Director Nuclear Operations DRB

Enclosure:

Callaway Energy Center Steam Generator Tube Inspection Report P.O. Box 620 : Fulton, FV1c 65251  : 4nierenFIlissouri.corii

ULNRC-06332 11 October, 2016 Page 2 cc: Mr. Kriss M. Kennedy Regional Administrator U. S. Nuclear Regulatory Commission Region IV 1600 East Lamar Boulevard Arlington, IX 76011-45 11 Senior Resident Inspector Callaway Resident Office U.S. Nuclear Regulatory Commission 8201 NRC Road Steedman, MO 65077 Mr. L. John Klos Project Manager, Callaway Plant Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Mail Stop 08H4 Washington, DC 20555-0001

ULNRC-063 32 11 October, 2016 Page 3 Index and send hardcopy to QA File A160.0761 Hardcopy:

Certrec Corporation 6100 Western Place, Suite 1050 fort Worth, TX 76107 (Certrec receives ALL attachments as long as they are non-safeguards and may be publicly disclosed.)

Electronic distribution for the following can be made via Responses and Reports ULNRC Distribution:

F. M. Diya T. E. Herrmann B. L. Cox R. C. Wink I. B. Elwood Corporate Communications NSRB Secretary Mr. Greg Voss, REP Manager (SEMA)

STARS Regulatory Affairs Mr. Jay Silberg (Pillsbury Winthrop Shaw Pittman LLP)

Ms. Leanne Tippett-Mosby (DNR)*

Callaway Energy Center 2016 Steam Generator Tube Inspection Report 1.0 PURPOSE The purpose of this report is to document that the Callaway Unit-i steam generator tube integrity performance criteria have been met for operating cycles 19, 20, and 21 (November 2011 to April 2016 of 3.975 EFPY duration) and to also demonstrate that there is reasonable assurance that the performance criteria will be met for the upcoming 3-cycle operating period, consisting of cycles 22, 23, and 24, not to exceed 4.25 EFPY.

2.0 REPORTING REQUIREMENTS Technical Specification 5.6.10 requires that A report shall be submitted within 180 days after initial entry into MODE 4 following completion of an inspection performed in accordance with Specification 5.5.9, Steam Generator (SG) Program. The report shall include:

a. The scope of inspections performed on each steam generator;

b. Degradation mechanisms found;

c. Nondestructive examination techniques utilized for each degradation mechanism;

d. Location, orientation (if linear), and measured size (if available) of service induced indications;

e. Number of tubes plugged during the inspection outage for each degradation mechanism;

f. The number and percentage of tubes plugged to date, and the effective plugging percentage in each steam generator; and

g. The results of condition monitoring, including the results of tube pulls and in-situ testing.

3.0

SUMMARY

The steam generator tube in-service inspections were completed by AREVA during the Refuel 21 outage. An in-service inspection was performed on all four steam generators, primary and secondary side. The scope of inspections performed is described in the following inspection report. The service related degradation mechanisms identified by eddy current inspection (primary side) were 543 AVB (anti-vibration bar) wear indications and 131 TSP (tube support plate) wear indications in total from all four steam liPage

Callaway Energy Center 2016 Steam Generator Tube Inspection Report generators. Callaways plugging limit was set at 30% 1W (through wall), conservatively, to maintain tube integrity for cycle 22, 23 and 24. In total, 25 tubes were removed from service due to AVB wear. TSP wear had no impact on RF-2 1 tube plugging. This equates to a total of 0.230% of tubes, from all four steam generators removed from service to date.

Table 1 Callaway Tube Cumulative Plugging Status Outage SGA SGB SGC SGD Total Pre-Service 1 0 0 0 1 1R15 0 0 0 0 0 iRiS 10 6 12 1 29 1R21 9 0 14 2 25 Total Tubes Plugged 20 6 26 3 55 Total Tubes 5872 5872 5872 5872 23488 Total Percentage 0.341% 0.102% 0443% 0.051% 0.230%

Limit(%) 10.0% 100% 100% 10.0% 10.0%

Sludge Lancing (secondary side) was performed on all 4 steam generators. A combined total of 25.5 pounds of sludge was collected by AREVA. The steam generator tubes and the top of tubesheet were clean, with exception of a small sludge pile located near the center of each steam generators top of tubesheet.

Steam Drum (secondary side) inspections were performed on only two steam generators, SO-A and SG-D. No loose parts (foreign material) or loose hardware was detected in either steam generator. finally, the Condition Monitoring Report concluded that the Callaway steam generator tubes satisfied the structural integrity performance criterion, accident induced leakage criterion and operational leakage criterion.

4.0 INSPECTION REPORT The Callaway Plant was shut down on April 2, 2016 for its 21St refueling outage. During the refueling outage an in-service inspection was performed on all four steam generators.

The inspection scope was as follows:

• Eddy current Bobbin probe examinations (All 4 SGs):

o 100% of all in-service tubes, full length tube-end to tube-end

• Eddy current X-probe examinations (All 4 SGs):

o Tubesheet periphery, 3-tubes deep 2Page

Callaway Energy Center 2016 Steam Generator lube Inspection Report o All cold leg tubes identified as having non-nominal tubesheet drilled hole diameters o 20% of hot leg tubes identified with sludge from the 1R1$ sludge analysis in all four SGs.

o All 1R21 Bobbin Distorted Support Signal with Indication (D$I) indications (i.e., TSP wear) in the Hot Leg of SGA and SGB

• Special interest examinations:

o All AVB wear with a depth ? 28%TW o All new AVB indications with a depth 14%TW o All AVB indications with a growth >14%TW over the past three cycles o Select tubes for AVB wear o All 1R21 Bobbin DSI indications

• Secondary Side Inspections:

o Top of Tubesheet (TTS) water lancing in all four SGs

• Pre-lancing quick-look visual inspection in SG C and SG D o Foreign Object Search and Retrieval (FOSAR) performed in all four $G

• Hot leg and cold leg TTS annulus area (post-lancing) looking in-bundle at the periphery tubes

• No-tube lane (post-lancing)

• Inner bundle passes in the hot leg TTS sludge pile region (post-lancing) o Visual inspections of steam drums in SG-A and SG-D

• Inspections included the loose part trapping screen, the riser barrels, the feedring and J-nozzles 1, 2, 3, 4, 29, and 30

• Visual Examinations o As-found and as-left visual examinations of primary channel heads (both Hot Leg and Cold Leg) o NSAL 12-1 (and IN 20 13-20) primary bowl inspections in all four SGs (both Hot Leg and Cold Leg) o Visual inspections of all plugs installed in the Callaway SGs both prior and during 1 P11 o EVT- 1 on SG-A primary nozzle inner radius. The area of interest consisted of all accessible surfaces of the nozzle inside radius section.

4.1 Primary Side Inspection The bobbin probe (ETSS 96004.1) is used for depth sizing AVB wear. The +Point (ETSS 96910.1) is used for depth and length sizing of TSP wear and providing extent and length sizing of AVB wear.

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Callaway Energy Center 2016 Steam Generator Tube Inspection Report 4.1.1 Eddy Current Inspections Table 2 RF21 Eddy Current Inspection Scope Summary ScD..crlption SGA SGB Exam Description Leg Probe Extent Planned Acquired Resolved RC0mr Plunned Acquired Resolved BobbIn Exams Fuil Length Rown6 HOT 61OHS TECTEH 5525 5525 5525 100.00% 5538 5530 5530 100.00%

H/LCandyCaneRows2.5 HOT 61OHS O8CTEH 270 270 270 100.00% 270 270 270 100.00%

H/LCatxiyCarieRowl HOT 61OHS O8CTEH 66 66 66 100.00% 66 66 66 100.00%

CL SEuig6 R1-5 COW 61OHS O8CTEC 336 336 336 100,00% 336 336 336 100.00%

Array Exams HILAIray HOT 61OXP O1HTEH 965 965 965 100.00% 965 965 965 100.00%

I-IL Array Skxlge Pde sample HOT G1OXP OIHTEH 22 22 22 100.00% 21 21 21 100.00%

CIL Array COLD 61OXP O1CTEC Scope Cancelled Scope Cancelled CL Array TS Drill SinaIs COW

- 610)0 O1CTEC 7 7 7 100.00% N/A N/A N/A J N/A Special Interest May& Point BOTH 610W Various Hot Leg irxbcalions HOT 610W Various 52 52 52 100.00% 35 35 35 100.00%

Cold Leg Ithcetionc COLD 610W Various 26 26 26 100.00% 7 7 7 100.00%

U-Bend lrstcarionc BOTh 610W Various 35 35 35 100.00% 17 17 17 100.00%

Total All Exams

[ 7304 f 7304 f 7304 1 00.00% 7247 7247 7247 100.00%

Scop.D..crlptlon SGC SGD Exam D.acrlplion Leg Probe Extent Planned Acquired Resolved Planned Acquired  % Complete Resolved Resolved Resolved Rnl,hlfl FLil Length Rcnes>°6 HOT 610H5 TECTEH 5524 5524 5524 100.00% 5535 5535 5535 100.00%

HLCIstdycarwRows2-5 HOT 6101-IS O8CTEH 270 270 270 100.00% 270 270 270 100.00%

FIlL CarelyCane Row 1 HOT 6101-IS O8CTEH 66 66 66 100.00% 66 66 66 100.00%

CL Strelolt R1-5 COLD 61OHS OSCTEC 336 336 336 100.00% 336 336 336 100.00%

Array Exams i4lLAnay HOT 610W O1HTEH 965 965 965 100.00% 965 965 965 100.00%

Ft&Array-SkalgePilesanrle HOT 610W O1HTEH 28 28 28 100.00% 19 19 l9 100.00%

C/L Array COW 610W O1CTEC Scope Cancelled Scope Cancelled C/LArrav-TSflrMlSianals COW 610W OICTEC N/A N/A ] N/A N/A 3 3 3 10000%

special lmsrest jTa* rmnt HoiLeglrdicaticx HOT 610W Various 12 12 12 100.00% 7 7 7 100.00%

Cold Leg Iroliceticars COIJ) 610W Various 9 9 9 100.00% 3 3 3 100.00%

U-Bend Ircicaricore BOTH 610W Various 44 44 44 100.00% 19 19 l9 100.00%

Total All Exams

- I 7254 I 7254 I 7254 I l0000% 7223 I 7223 ( 7223 I 00.00%

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Callaway Energy Center 2016 Steam Generator Tube Inspection Report Table 3 RF21 Summary of Wear Indications (Tubes I Indications)

SG A SG B SG C SG D Total Detected AVB 72 160 47 97 106 240 22 46 247 543 TSP 41 56 23 29 19 30 9 16 92 137 124(2) 335(1)(2)(3)

Total iii 216 70 726 270 30 62 674 Plugged AVG 9 40 0 0 14 56 2 8 25 104 Tsp 1 1 0 0 0 0 0 0 1 1 gd) 25t1)

Total 41 0 0 14 56 2 8 105 Returned to Service AVG 63 120 47 97 92 184 20 38 222 439 TSP 40 55 23 29 79 3a 9 16 91 130 j02t1) 31gt1t3)

Total 175 70 126 J10 214 28 54 569 NOTES:

1) SGA Tubes 110-66 and 117-73 have both AVG and TSP wear. Tube 111-73 was plugged for AVG wear

2) SGC Tube 110-72 has both AVB and TSP wear

3) SGD Tube 88-72 has both AVB and TSP wear Callaway plugged 25 tubes due to AVB wear during refuel 21. The total number of tubes repaired to date is 55 (1 plugged during manufacturing). This is 0.230% total tubes plugged to date.

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Callaway Energy Center 2016 Steam Generator Tube Inspection Report Table 4 RF21 Summary of AVB Wear Bobbin Indications Number of New and Repeat Depths Growth Rate of Repeats Indications t%1W) f%TWIEFPY)

SG Repeat UPPr Upper New Average Maximum Average Maximum A 35 125 15.2 29.1 33.0 1.2 2.8 3.3 B 18 79 14.1 26.0 30.0 0.7 2.0 3.0 C 39 201 15.2 32.0 37.0 1.1 3.0 6.3 D 7 39 141 33.8 38.0 0.9 3.0 3.8 AU SGs 99 444 14.9 30.9 38.0 1.1 3.0 63 AVB wear was reported in each of the four steam generators. A total of 543 AVB wear indications were detected. The maximum reported AVB wear depth was 3$%TW.

Table 5 RF21 Summary of TSP Wear Indications Number of New and Repeat Depths Growth Rate of Repeats Indications f%7W) (%TWIEFPY)

SG New Repeat Average UPPt Uppr Maximum Average Maximum A 43 13 7.27 11 17.00 0.66 1.61 1.76 3 20 9 10.59 15 16.00 1.17 1.66 1.76 C 22 8 9.87 14 16.00 0.69 1.42 1.51 D 13 3 5.38 8 11.00 0.17 0.25 0.25 All SGs 98 33 8.37 14 17.00 0.76 1.61 1.76 TSP wear was reported in each of the four steam generators. A total of 131 TSP wear indications were detected. The maximum reported TSP wear depth was 1 7%TW.

4.1.2 Primary Side Visual Examination Remote visual examinations of the primary channel heads in each steam generator were performed to the NSAL 12-1 requirements. No degradation of the cladding, welds, or structures was identified within the channel heads, and no foreign objects were identified.

SG-A primary nozzle inside radius inspection did not identify any indications. No plug deficiencies were identified.

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Callaway Energy Center 2016 Steam Generator Tube Inspection Report 4.2 Secondary Side Inspections The planned FOSAR (annulus, no-tube lane, and inner bundle passes) examinations were performed in each of the four $Gs following water lancing. No foreign objects were detected. Visual inspections of the steam drums in SG-A and SG-D were performed as planned.

4.2.1 Steam Drum Inspections Secondary side inspections were performed in the steam drums of SG-A and SG-D. No loose parts or loose hardware was detected in either 5G.

4.2.2 Sludge Lancing Sludge Lancing was performed on all 4 steam generators. A combined total of 25.5 pounds of sludge was collected by AREVA. The steam generator tubes and the top of tubesheet were clean, with exception of a small sludge pile located near the center of each steam generators top of tubesheet.

Table 6 RF21 Sludge Lancing Results 1 I. 1- i SGA SGB SGC SGD TOTAL Sludge Removed fIbs) 6 3 10.5 6 25.5 4.3 Condition Monitoring The Condition Monitoring report concluded that the Callaway steam generator tubes satisfied the structural integrity performance, accident-induced leakage and operational leakage performance criteria in accordance with Technical Specifications 5.5.9, 3.4.13 and 3.4.17. Callaway did not perform any tube pulls or in-situ testing.

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