ULNRC-05866, Results of Steam Generator Tube In-Service Inspection
| ML12139A275 | |
| Person / Time | |
|---|---|
| Site: | Callaway  |
| Issue date: | 05/17/2012 |
| From: | Neterer D Ameren Missouri, Union Electric Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| ULNRC-05866 | |
| Download: ML12139A275 (10) | |
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WAmeren MISSOURI Callaway Plant May 17, 2012 ULNRC-05866 u.s. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001 Ladies and Gentlemen:
DOCKET NUMBER 50-483 CALLA WAY PLANT UNIT 1 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 16, 17, and 18, and also demonstrates reasonable assurance that the performance criteria will be met for the upcoming 3-cycle operating period, consisting of cycles 19, 20, and 21.
This letter does not contain new commitments.
ACS/nis Sincerely, David W. Neterer, Plant Director
Enclosure:
Callaway Energy Center Steam Generator Tube Inspection Report PO Box 620 Fulton, MO 65251 AmerenMissouri.com
ULNRC-05866 17 May 2012 Page 2 cc:
Mr. Elmo E. Collins Regional Administrator U. S. Nuclear Regulatory Commission Region IV 1600 East Lamar Boulevard Arlington, TX 76011-4511 Senior Resident Inspector Callaway Resident Office U.S. Nuclear Regulatory Commission 8201 NRC Road Steedman, MO 65077 Mr. Kaly Kalyanam Senior Project Manager, Callaway Plant Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Mail Stop 0-8014 Washington, DC 20555-2738
ULNRC-05866 17 May 2012 Page 3 Index and send hardcopy to QA File A160.0761 Hardcopy:
Certrec Corporation 4150 International Plaza Suite 820 Fort Worth, TX 76109 (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:
A. C. Heflin F. M. Diya C. O. Reasoner III L. H. Graessle S. M. Maglio T. B. Elwood R. Holmes-Bobo NSRB Secretary Mr. Paul Parmenter, Director (SEMA)
Mr. Thomas Mohr, Senior REP Planner (SEMA)
Mr. Tom Masso, REP Planner (SEMA)
Mr. Bill Muilenburg (WCNOC)
Mr. Tim Hope (Luminant Power)
Mr. Ron Barnes (APS)
Mr. Tom Baldwin (PG&E)
Mr. Mike Murray (STPNOC)
Ms. Linda Conklin (SCE)
Mr. John O'Neill (Pillsbury Winthrop Shaw Pittman LLP)
Mr. Dru Buntin (DNR)
Callaway Energy Center 2012 Steam Generator Tube Inspection Report 1.0 PURPOSE The purpose of this report is to document that the Callaway Unit-l steam generator tube integrity performance criteria have been met for operating cycles 16, 17, and 18 (May 2007 to October 2011 of 4.099 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 19, 20, and 21, with an estimated duration of 4.2 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 in accordance with Specification 5.5.9, Steam Generator (SG) Program." This report shall include:
- a. The scope of inspections performed on each steam generator;
- b. Active degradation mechanisms found;
- c. Nondestructive examination techniques utilized for each degradation mechanism found;
- d. Location, orientation (if linear), and measured size (if available) of service induced degradation;
- e. Number of tubes plugged during the inspection outage for each active degradation mechanism;
- f.
Total number and percentage of tubes plugged to date, 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 AREV A during the Refuel 18 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 589 AVB (anti-vibration bar) wear indications and 34 TSP (tube support plate) wear indications total from all four steam generators. Callaway's plugging limit was set at 28% TW (through wall), conservatively, IIPage
Callaway Energy Center 2012 Steam Generator Tube Inspection Report to maintain tube integrity for cycle 19, 20 and 21. In total, 29 tubes were removed from service due to AVB wear. TSP wear had no impact on RF-18 tube plugging. This equates to a total of 0.128% of tubes, from all four steam generators removed from service.
Sludge Lancing (secondary side) was perfonned on all 4 steam generators. A combined total of 11 pounds of sludge was collected by AREV A. 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 tube sheet.
Steam Drum (secondary side) inspections were perfonned on only two steam generators, "Bravo" and "Charlie". 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 perfonnance criterion, accident induced leakage criterion and operational leakage criterion.
4.0 INSPECTION REPORT Callaway Plant shut down October 15, 2011 for its 18th refueling outage. During that time an in-service inspection was perfonned 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 o During the bobbin probe examination, verify that tubes bounding any plugged tubes do not exhibit signs of tube-to-tube proximity or contact.
o Visual inspection of previously installed plug 1 plug in SG-A tube 13-109 (welded plug)
Eddy current X-probe examinations (All 4 SGs):
o Tubesheet Periphery 3-tubes deep o No-tube lane 6-tubes deep o Nine (9) of the 33 miss-drilled tubes o PLP bounding not already examined using the rotating coil The X-probe will acquire data from the tube-end to one inch past the first support (both hot and cold legs). The data will be analyzed from three inches below the TTS to one inch above the first support, TTS-3.00" to 0 1 H + 1.00" and TTS-3.00" to 01 C+ 1.00".
Special interest examinations:
o A VB wear (as needed to support CMOA) o Bobbin I-codes (e.g., ADI, DFI, DSI, DTI, LPI, and NQI) o ArrayNQIs 21 P age
Callaway Energy Center 2012 Steam Generator Tube Inspection Report o New Bobbin (e.g., DNT, IDC, PVN, BLG, Wear: [SPT, TSPJ) o PLPs and bounding tubes not already examined using X-probe o PLPs exhibiting loose part wear (even if inspected using X-probe) o 20% random sample per SG of DNGs reported by bobbin o Nine (9) of the 33 miss-drilled tubes o At discretion of analyst or tube integrity engineering Secondary Side Inspections:
o Foreign Object Search and Retrieval (FOSAR) as follows:
As required based on ECT TTS annulus area in all four SGs (following lancing)
No-tube lane in all four SGs (following lancing)
Inner bundle passes (following lancing) o Visual inspections of steam drums in SG-B and SG-C 4.1 Primary Side Inspection The bobbin probe (ETSS 96004.1) is used for depth sizing both AVB wear and TSP wear, and the +Point' probe is used for extent and length sizing.
4.1.1 Eddy Current Inspections Table 1 Eddy Current Testing Task Summary (Tubes Inspected)
ECT Task Extent S/GA S/GB S/GC S/GD Total Tubes 100% Bobbin Tube end hot to 5535 5536 5536 5536 22143 F/L tube end cold Array Top of Tubesheet 965 965 965 965 3860 H/L
+3"1-3" Special Specified 90 61 76 35 262 Interest +Point location (Note: 1 tube plugged m S/G A durmg manufactunng)
F IL = Full Length H/L = Hot Leg (no cold leg array performed) 31Page
AVB TSP Total AVB TSP Total AVB TSP Total Callaway Energy Center 2012 Steam Generator Tube Inspection Report Table 2 Summary of Wear Indications (Tubes I Indications)
SGA SGB SGC SGD Total Detected 71 180 40
'108 100 256 21 45 232 589 11 13
'10 11 5
7 2
3 28 34 82 193 49*
'119 105 263 22*
48 258*
623 Plugged 10 47 6
29 12 53 1
4 29 133 0
0 1
2 0
0 0
0
'I 2
10 47 6*
31 12 53 1
4 29*
135 Returned to Service 61 133 34 79 88 203 20 41 203 456 1'1 13 9
9 5
7 2
3 27 32 72 146 43 88 93 2'10 21*
44 229*
488 Callaway plugged 29 tubes due to AVB wear during refuel 18. The total number of tubes repaired to date is 30 (l plugged during manufacturing). This is 0.128% total tubes plugged to date.
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SG SGA SGA SGA SGA SGA SGA SGA SGA SGA SGA SGA 5GA SGA 5GB SGB 5GB 5GB 5GB SGB SGB SGB 5GB 5GB SGB SGC SGC SGC SGC SGC SGC SGC SGD SGD SGD Callaway Energy Center 2012 Steam Generator Tube Inspection Report Table 3 Summary of Callaway RF-18 TSP Wear Indications Tube Elevation Bobbin RPC Axial RPC eire Row-Col TSP+/- inch
%TW length Extent finchesl lDeoreesl 71-119 OSC -0.S8 9
0.49 40 81-23 05C -0.S8 13 0.5 44 97-35 OSC -0.S7 10 0.37 44 100-68 OSH +0.35 8
0.35 43 102-74 04C +0.48 10 0.34 36 102-74 OSH +0.33 10 0.48 39 104-94 OSC -0.66 9
0.44 36 105-91 05H -0.73 8
0.46 39 105-91 OSH -0.75 8
0.35 35 107-85 06H +0.31 12 0.59 43 108-84 06H -0.76 9
0.51 39 110-80 06H +0.31 11 0.43 39 113-65 04C +0.55 9
0.34 36 89-37 05H -0.76 9
0.29 32 89-59 05H +0.33 9
0.37 36 91-65 08C -0.67 15 0.81 48 91-65 OSC +0.25 8
0.42 36 106-82 05H -0.73 9
0.29 36 108-84 06H +0.27 7
0.56 32 108-86 OSH -0.79 9
0.35 36 110-72 06C +0.42 10 0.39 36 110-74 04C +0.4S 10 0.34 32 111-77 OSH +0.35 11 0.37 32 112-78 05H -0.75 12 0.32 36 103-73 04H +0.42 9
0.21 24 108-84 06H -0.7 11 0.34 56 112-60 04C +0.52 15 0.39 44 112-76 05H -0.73 10 0.31 40 113-67 06C +0.46 7
0.39 32 113-67 07C -0.62 7
0.21 32 113-67 07C +0.42 9
0.42 36 88-72 08C -0.78 8
0.57 23 88-72 OSC +0.29 S
0.27 27 106-56 06H -0.81 10 0.29 44 TSP wear was reported in each of the four steam generators. A total of 34 TSP wear indications were detected. The maximum reported TSP wear depth was 15%TW. The maximum reported axial length was 0.59 inches. The maximum reported circumferential extent was 48 degrees.
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Callaway Energy Center 2012 Steam Generator Tube Inspection Report Table 4 Callaway RF -18 A VB Wear Depths New + Repeat W. TW)
SG Average Upper'95th Maximum A
14.2 28.0 35 B
14.7 28.3 37 C
14.1 28.3 39 0
11.9 25.2 30 All 14.1 28.0 39 SGs Summary of A VB wear depth statistics for both new and repeat indications. Maximum
%TW was identified in "Charlie" steam generator, which was 39%.
4.2 Secondary Side Inspections The planned FOSAR (annulus, no-tube lane, and inner bundle passes) examinations were performed in each of the four SOs following water lancing. Visual inspections of the steam drums in SOs Band C were performed as planned.
4.2.1 Steam Drum Inspections Secondary side inspections were performed in the steam drums of SOB and SOC. No loose parts or loose hardware was detected in either SO.
4.2.2 Foreign Objects and PLP Inspections The bobbin coil and X -probe data was reviewed for possible loose part! wear indications.
There were no PLPs or foreign object degradation (in any SO) detected by ECT inspections. Oiven this condition, no TTS FOSAR was required at lR18 for ECT PLP indications. FOSAR however was performed following water lance activities in each of the four SOs. The post water lance FOSAR only detected a small piece of scale in the cold-leg of SOA. No other loose parts were detected in the other three SOs.
4.2.3 Sludge Lancing Sludge Lancing was performed on all 4 steam generators. A combined total of 11 pounds of sludge was collected by AREV A. The steam generator tubes and the top of tubesheet 61 P age
Callaway Energy Center 2012 Steam Generator Tube Inspection Report were clean, with exception of a small sludge pile located near the center of each steam generators top of tubesheet.
Table 5 Callaway RF-18 Sludge Lancing Results SGA SGB SGC SGD Pounds of Sludge 4
1 4
)
Reilloved 4.3 Condition Monitoring The Condition Monitoring report concluded that the Callaway steam generator tubes satisfied the structural integrity performance criterion, accident induced leakage criterion and operational leakage performance criterion specified in Technical Specification 5.5.9 and LCO 3.4.13, respectively. Callaway did not perform any tube pulls or in-situ testing.
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