ML14342B004

Cycle 19 - 180-Day Steam Generator Tube Inspection Report

ML14342B004
Person / Time
Site:	Sequoyah
Issue date:	12/01/2014
From:	John Carlin Tennessee Valley Authority
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
Download: ML14342B004 (22)

Text

Tennessee Valley Authority, Post Office Box 2000, Soddy Daisy, Tennessee 37384-2000 December 1, 2014 10 CFR 50.4 ATTN: Document Control Desk U. S. Nuclear Regulatory Commission Washington, D.C. 20555-0001 Sequoyah Nuclear Plant, Unit 2 Facility Operating License No. DPR-79 NRC Docket No. 50-328

Subject:

Unit 2 Cycle 19 - 180-Day Steam Generator Tube Inspection Report In accordance with Sequoyah Nuclear Plant (SQN), Unit 2, Technical Specification 6.8.4.k, Steam Generator Program and Technical Specification 6.9.1.16.1, Steam Generator Tube Inspection Report, the Tennessee Valley Authority is submitting the 180-day Steam Generator (SG) Tube Inspection Report that includes the results of inservice inspections performed on Unit 2 SGs during the Unit 2 Cycle 19 refueling outage. SQN Unit 2 Cycle 19 was completed on June 18, 2014, therefore, the due date for this report is December 15, 2014.

There are no new regulatory commitments contained in this letter. If you have any questions concerning this report, please contact Erin Henderson at (423) 843-7170.

Repe Ily, ic President Seq ah Nuclear Plant

Enclosure:

Unit 2 Cycle 19 - 180-Day Steam Generator Tube Inspection Report cc: See Page 2

U.S. Nuclear Regulatory Commission Page 2 December 1, 2014 Enclosure cc (Enclosure):

NRC Regional Administrator- Region II NRC Senior Resident Inspector - Sequoyah Nuclear Plant

U.S. Nuclear Regulatory Commission Page 3 December 1, 2014 ERH:JWP:SKJ Enclosure bcc (Enclosure):

NRC Project Manager - Sequoyah Nuclear Plant M. A. Balduzzi T. J. Bradshaw (NSRB Support)

C. R. Church D. M. Czufin J. P. Grimes T. A. Hess M. R. Henderson M.W. McBrearty P. T. Noe W. J. Pierce P. P. Pratt E. D. Schrull J. W. Shea.

S. A. Vance R. J. Whalen I:License/Steam Generators/cycle 19/U2C19 SG 180-Day SG Report.doc

ENCLOSURE TENNESSEE VALLEY AUTHORITY SEQUOYAH NUCLEAR PLANT UNIT 2 CYCLE 19 180-DAY STEAM GENERATOR TUBE INSPECTION REPORT

A 20004-021 (01/30/2014)

AREVA AREVA Inc.

Engineering Information Record Document No.: 51 - 9198837 - 001 Sequoyah U2R19 Steam Generator Inspection 180-day Report Page 1 of 18

A 20004-021 (01130=2014)

Document No,; 51-9d98837-00a ARE VA Sequoyah U2R19 8tern Generator Inspection 180-day Report SafetyRelated? ZInS QNO Does this document establish design or tecnilcal rcqireme.fls7 fYE. O'NO Does this document contain sumptions requiuingverficfion? ' []YES O NO Does this docament contain Customer Required Format? 1] YES IM NO Signature Block Pagesisoctlons Name and PI. PP, RILR, .reparedlavlewedl TitleMIlsclpIlrne Signature A-CRF, A Dite Approved or Comments Victor Newman LP Al pciujeal aEngineer,1f

.reff Brown Lkt- All Advisry Engi=e A_ __ rvzC{014 ________

lames Campbell A All TeblaMaager,'T/I David lamas. Customer All TVA %4Wf10"4 wOU Approval i1At/t1 Jeremy Mayo Customer Ali TVA - Approval a/sz /,j Tummy SearsCustoe All TVA -C&,---ppova //z4yI Note: P/12 designates PPmparer (P), Lead Preparer (LP)

RJLR dedgnates Reviewer (R), Lead Rviewer (LR)

A-CRF desigous Project Manager Approver of Customer Required Format (A-CRM)

A designates Approver/RTM- Verification ofRoviewer Independence Project Manager Approval of Customer References (WA If not applicable)

Name Title (printed or typed) (printed or typed) Signature Date MAr Lukwald j Project Manager. NA 14/A Page 2

A 20004-021 (01/30/2014)

Document No.: 51-9198837-001 AREVA Sequoyah U2R19 Steam Generator Inspection 180-day Report Record of Revision Revision Pages/Sections/

No. Paragraphs Changed Brief Description / Change Authorization 000 Initial Release N/A 001 Cover Page Proprietary Statement removed at the request of the customer.

Changed "Fall" to "Spring" in first sentence of section 1.0 Page 3

A Document No.: 51-9198837-001 AR EVA Sequoyah U2R19 Steam Generator Inspection 180-day Report Table of Contents Page SIG NATURE BLO CK ............................................................................................................................. 2 RECO RD O F REVISIO N ....................................................................................................................... 3 LIST O F TABLES .................................................................................................................................. 5 LIST O F FIG URES ................................................................................................................................ 6 1.0 INTRO DUCTIO N ........................................................................................................................ 7 2.0 180-DAY STEAM GENERATOR TUBE INSPECTION REPORT .......................................... 9

3.0 REFERENCES

......................................................................................................................... 18 Page 4

A Document No.: 51-9198837-001 AR EVA Sequoyah U2R19 Steam Generator Inspection 180-day Report List of Tables Page TABLE 2-1: EDDY CURRENT INSPECTION SCOPE ................................................................... 10 TABLE 2-2: NUMBER OF INDICATIONS DETECTED FOR EACH DEGRADATION MECHANISM... 14 TABLE 2-3: NDE TECHNIQUES USED FOR EACH DEGRADATION MECHANISM ...................... 15 TABLE 2-4: SERVICE-INDUCED INDICATIO NS ............................................................................ 16 TABLE 2-5: NUMBER OF TUBES PLUGGED FOR EACH DEGRADATION MECHANISM ............... 16 TABLE 2-6: TOTAL NUMBER AND PERCENTAGE OF TUBES PLUGGED TO DATE .................. 16 Page 5

A Document No.: 51-9198837-001 AREVA Sequoyah U2R19 Steam Generator Inspection 180-day Report List of Figures Page FIGURE 1-1: TUBE SUPPORT ARRANGEMENT FOR SEQUOYAH-2 STEAM GENERATORS ......... 8 Page 6

A Document No.: 51-9198837-001 AR EVA Sequoyah U2R19 Steam Generator Inspection 180-day Report

1.0 INTRODUCTION

During the Sequoyah Unit 2 (SQN2) Spring 2014 refueling outage (designated as EOC1 9), inspections of all four SQN2 steam generators (SGs) were performed. These inspections included eddy current inspections of the SG tubing as well as primary and secondary side visual inspections. This report documents the "Sequoyah U2R19 SG Inspection 180-Day Report" as required by the SQN2 Technical Specifications [2].

Commercial operation of the original steam generators began in 1982. Operation of the replacement steam generators (RSG) Westinghouse/Model 57AG SG design began following the Unit 2 EOC18 2012 refueling/steam generator replacement outage. The steam generators operated 1.385 EFPY in their first cycle after replacement.

The first ISI was performed during this most recent U2R19 refueling outage. Additional information is available in Reference [1].

Figure 1-1 below provides the arrangement of the tube support structures for the SQN2 SGs.

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A Document No.: 51-9198837-001 AREVA Sequoyah U2R19 Steam Generator Inspection 180-day Report Figure 1-1: Tube Support Arrangement for Sequoyah-2 Steam Generators Model 57AG+

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A Document No.: 51-9198837-001 AR EVA Sequoyah U2R19 Steam Generator Inspection 180-day Report 2.0 180-DAY STEAM GENERATOR TUBE INSPECTION REPORT In accordance with SQN2 Technical Specification [2] this report documents the scope and results of the U2R19 SG inspections. There are eight specific reporting requirements (labeled "a" through "h" below). Each reporting requirement is followed with the required information based on the inspections performed during the U2R19 outage.

a. The Scope of the Inspections Performed on Each SG The U2R19 outage bobbin coil inspection was planned for 100% of the in-service tubes. In addition to the bobbin coil inspections, 4816 array coil inspections were also performed. The array coil exams were aimed at detection of foreign objects and foreign object wear near the top of the tubesheet and support wear up to the C07 cold leg support. 206 additional Special Interest exams were performed with array coil or +Point as required. (see Table 2-1).

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A Document No.: 51-9198837-001 AREVA Sequoyah U2R19 Steam Generator Inspection 180-day Report Table 2-1: Eddy Current Inspection Scope BOBBIN Tests Total Planned Tests Analyzed and Percent Remaining to S/G Exams Acquired Change Completed Change Retests Change Complete Inspect F/L Combo Array/Bobbin 344 344 0 344 0 0 100.00% 0 2-1 Full Length rows 5+ 4391 4391 0 4391 ____

0 43 0 100.00% 0 H/L candycane rows 1-4 248 248 0 248 0 0 100.00% 0 C/L straight rows 1-4 248 N/A 248 0 0 100.00% 0 F/L Combo Array/Bobbin 339 339 0 339 0 0 100.00% 0 2-2 Full Length rows 5+ 4396 4396 ____

0 4396 0 4 0 100.00% 0 H/L candycane rows 1-4 248 248 0 248 0 14 0 100.00% 0 C/L straight rows 1-4 248 N/A 248 0 3 0 100.00% 0 F/L Combo Array/Bobbin 350 350 0 350 0 0 100.00% 0 2-3 Full Length rows 5+ 4385 4385 0 4385 0 85 0 100.00% 0 H/L candycane rows 1-4 248 248 0 248 0 0 100.00% 0 C/L straight rows 1-4 248 N/A 248 0 0 100.00% 0 F/L Combo Array/Bobbin 346 346 0 346 0 0 100.00% 0 2-4 Full Length rows 5+ 4389 4389 0 4389 0 11 0 100.00%

0 H/L candycane rows 1-4 248 248 0 248 0 0 100.00% 0 C/L straight rows 1-4 248 N/A 248 0 0 100.00% 0 TOTAL 20924 19932 0 20924 0 160 0 100.00% 0 Page 10

A Document No.: 51-9198837-001 AR EVA Sequoyah U2R19 Steam Generator Inspection 180-day Report Table 2-1 continued Array Top of Tubesheet Tests Total Planned Tests Analyzed and Percent Remaining to S/G Exams Acquired Change Completed Change Retests Change Complete Inspect HL = H01-HTE (from Bobbin/Array Combo Exam) 346 N/A N/A 346 0 0 N/A 100.00% 0 2-1 HL = H01-HTE 258 258 0 258 0 1 0 100.00% 0 CL = CO1-CTE (from Bobbin/Array Combo Exam) 346 N/A N/A 346 0 0 N/A 100.00% 0 CL = C07-CTE 258 258 0 258 0 0 0 100.00% 0 HL = H01-HTE (from Bobbin/Array Combo Exam) 339 N/A N/A 339 0 0 N/A 100.00% 0 258 258 0 258 0 0 0 100.00% 0 2-2 HL = H01-HTE CL = COI-CTE (from Bobbin/Array Combo Exam) 339 N/A N/A 339 0 0 N/A 100.00% 0 CL = C07-CTE 258 258 0 258 0 0 0 100.00% 0 HL = HOI-HTE (from Bobbin/Array Combo Exam) 350 N/A N/A 350 0 0 N/A 100.00% 0 2-3 HL = H01-HTE 258 258 0 258 6 0 0 100.00% 0 CL = COi-CTE (from Bobbin/Array Combo Exam) 350 N/A N/A 350 0 0 N/A 100.00% 0 CL = C07-CTE 248 248 0 248 0 0 0 100.00% 0 HL = H01-HTE (from Bobbin/Array Combo Exam) 346 N/A N/A 346 0 9 N/A 100.00% 0 HL = H01-HTE 258 258 0 258 0 0 0 100.00% 0 2-4 CL = C01-CTE (from Bobbin/Array Combo Exam) 346 N/A N/A 346 0 N/A 100.00% 0 CL = C07-CTE 258 258 0 258 0 0 0 100.00% 0 TOTAL 1 4816 2054 0 4816 6 10 0 100.00% 0 Page 11

A Document No.: 51-9198837-001 AREVA Sequoyah U2R19 Steam Generator Inspection 180-day Report Table 2-1 continued Specii Interest Exam Tests Total Locations to Tests Analyzed and Percent Remaining to SIG Inspect Acquired Change Completed Change Retests Change Complete Inspect H/L SI RPC 3 3 0 3 0 0 0 100.00%

CIL SI RPC 1 1 0 1 0 0 0 100.00%

2-1 U-Bend SI RPC 29 29 0 29 0 2 0 100.00%

HiL SI Array 30 30 0 30 0 0 0 100.00%

CIL SI Array 2 2 0 2 0 0 0 100.00%

HIL SI RPC 2 2 0 2 0 0 0 100.00%

CIL SI RPO 6 6 0 6 0 0 0 100.00%

2-2 U-Bend SI RPC 15 15 0 15 0 0 0 100.00%

H/L SI Array 23 23 0 23 0 0 0 100.00%

CIL S1Array 7 7 0 7 0 0 0 100.00%

H/L SI RPC 0 0 0 0 0 0 0 CIL SI RPC 0 0 0 0 0 0 0 2-3 U-Bend SI RPC 3 3 0 3 0 0 0 100.00%

H/L S1Array 29 29 0 29 0 0 0 100.00%

CIL SI Array 4 4 0 4 0 0 0 100.00%

H/L SI RPC 11 11 0 11 0 0 0 100.00%

CIL SI RPC 7 7 0 7 0 0 0 100.00%_

2-4 U-Bend SI RPC 8 8 0 8 0 0 0 100.00%

HIL SI Array 17 0 0 17 0 0 0 100.00%

CIL S I Array 9 9 0 9 0 0 0 100.00%

TOTAL 206 189 43 206 0 2 0 100.00% 0 Page 12

A Document No.: 51-9198837-001 AREVA Sequoyah U2R19 Steam Generator Inspection 180-day Report Table 2-1 continued All Scopes Summary Tests Total Tests Analyzed and Percent Remaining to S/G Total Exams Acquired Change Completed Change Retests Change Complete Inspect 2-1 6504 5564 0 6504 0 46 0 100.00% 0 2-2 6478 5552 0 6478 0 21 0 100.00% 0 2-3 6473 5525 0 6473 6 85 0 100.00% 0 2-4 6491 5534 0 6491 0 20 0 100.00% 0 TOTAL 25946 22175 0 25946 6 172 0 100.00% 0 Page 13

A Document No.: 51-9198837-001 AREVA Sequoyah U2R19 Steam Generator Inspection 180-day Report Visual Inspection Results In addition to the eddy current inspections, visual inspections were also performed on both the primary and secondary sides [1].

Primary Side:

• SG Channel Head interior as-found and cladding inspection.

• Since there were no plugs installed in the SGs, plug inspection was not applicable

• During the initial channel head visual as-found and cladding inspection, discolored areas were noted, particularly in SG 22 cold leg. The discoloration was evaluated by the SG OEM and deemed not to affect SG function or integrity. The discoloration will be monitored in future inspections. Causal reasons for the discoloration are indeterminate. Possible explanations range from residue left during the electropolishing of the primary channel head bowls to refraction effects of the LED lights utilized during the examination of the primary channel head inspection which identified the discoloration [1].

Secondary Side:

" Foreign Object Search and Retrieval (FOSAR) in all SGs as follows:

o As required based on ECT (none required in the absence of any applicable ECT indications) o Removal of foreign objects detected visually o TTS annulus area in all four SGs (following lancing) o No-tube lane in all four SGs (following lancing) o In the area of foreign objects removed, to inspect for visual evidence of damage (no damage found)

b. Active Degradation Mechanisms Found Volumetric wear was the only degradation mechanism detected during the U2R1 9 inspection. All of the wear indications detected were located at U-bend support structures in SG22. None of the indications were plugged. No wear indications attributable to foreign objects were reported. Table 2-2 below shows the number of indications reported during the U2R19 inspection Table 2-2: Number of Indications Detected for Each Degradation Mechanism SG21 SG22 SG23 SG24 Total Location Tubes Indications Tubes Indications Tubes Indications Tubes Indications Tubes Indications Deteted U-bend Detected support 0 0 2 3 0 0 0 0 2 3 Plugged U-bend 0 0 0 0 0 0 0 0 0 0 support ____ ____ ________ ___ _ ___

Returned U-bend to Service support supr 0 0 2 3 0 0 0 0 2 3 Page 14

A Document No.: 51-9198837-001 AREVA Sequoyah U2R19 Steam Generator Inspection 180-day Report

c. Nondestructive Examination (NDE) Techniques Used for Each Degradation Mechanism Table 2-3 below provides the NDE techniques that were qualified for the detection of each degradation mechanism that was considered as existing or potential for the U2R19 inspection [3]. Not all techniques were used as some mechanisms (e.g. loose parts wear, pitting, and tube-to-tube wear) were not detected.

Table 2-3: NDE Techniques Used for Each Degradation Mechanism Degradation Location Inspection Technique EPRI ETSS Mechanism Bobbin / Differential / Detection & Sizing 96004.1 Rev 13 Bobbin / Absolute / Detection & Sizing 96004.3 Rev 13

+Point / Straps and Supports / Detect and 96910.1 Rev. 10 Size 10908.4 Rev 1 Bobbin /Absolute / Detection 13091.1 Rev. 0

+Point / TMSizing 13901.1 Rev. 1 Tube Wear Tube-to-tube X-Probe / Detection / Sizing (Axial) 13902.1 Rev. 0 X-Probe TM / Detection / Sizing (Circ) 13902.2 Rev. 0 27091.2 Rev 1 Bobbin / Differential / Detection 27091.3 Rev 1 Bobbin / Absolute / Detection 21998.1 Rev 4 27901.1 Rev 1

+Point / Sizing 27902.1 Rev 1 TM 27903.1 Rev1 Loose Parts X-ProbeTM / TSP Wear (Axial sensitive coil 27904.1 Rev 1 Tube Wear 27905.1 Rev 1 set) /

27906.1 Rev 1 Detection 27907.1 Rev 1 X-Probe / TSP Wear (Circumferential M

T 27907.1 Rev 1 sensitive coil set) / Detection 11956.4 Rev 2 Bobbin / Differential / Detection 96005.1 Rev 9 Pitting Freespan X-ProbeTM / Detection 24998.1 Rev 1 MBM Freespan Bobbin / Absolute / Detection 96010.1 Rev 7 In addition to the detection techniques shown in the above table, +PointTM probes were also used for confirmation, characterization, and length sizing of wear indications at the U-bend supports.

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A Document No.: 51-9198837-001 AREVA Sequoyah U2R19 Steam Generator Inspection 180-day Report

d. Location, Orientation (if Linear), and Measured Sizes (if Available) of Service Induced Indications Table 2-4 below provides a listing of all service-induced indications reported during the U2R1 9 inspection including the estimated depths from the bobbin coil. If length sizing was available, this information is also provided as reported from the +PointTM inspections.

Table 2-4: Service-Induced Indications SG Row Col Location Depth (%TWD) Length (in.)

(bobbin) (+Point) 22 89 59 VS2 -0.83 7 0.35 22 93 59 VS3 +0.81 6 0.37 22 93 59 VS2 -1.14 12 0.58

e. Number of Tubes Plugged During the Inspection Outage for Each Active Degradation Mechanism Table 2-5 below provides the number of tubes plugged for each degradation mechanism detected.

Table 2-5: Number of Tubes Plugged for Each Degradation Mechanism Inspection SG21 SG22 SG23 SG24 Total Prior to service 0 0 0 0 0 2R19 2014 0 0 0 0 0 Total 0 0 0 0 0

f. Total Number and Percentage of Tubes Plugged to Date Table 2-6: Total Number and Percentage of Tubes Plugged to Date Inspection SG21 SG22 SG23 SG24 Total Prior to service 0 tubes 0% 0 tubes 0% 0 tubes 0% 0 tubes 0% 0 tubes 0%

2R19 2014 0 tubes 0% 0 tubes 0% 0 tubes 0% 0 tubes 0% 0 tubes 0%

Total 0 tubes 0% 0 tubes 0% 0 tubes 0% 0 tubes 0% 0 tubes 0%

g. The Results of Condition Monitoring, Including the Results of Tube Pulls and In-Situ Testing As required by the SQN2 Steam Generator Program, a condition monitoring (CM) assessment was performed [1]. The only tube degradation detected during the U2R19 inspection was wear at U-bend support structures. The deepest indication had an estimated depth of 12%TW from the bobbin coil exam.

The maximum NDE length of any wear flaw was 0.58". The CM limit for a flaw of this length is approximately 48% TWD. This CM limit includes uncertainties for material properties, NDE depth sizing, and the burst pressure relationship. Since the deepest flaw has an NDE depth less than the CM limit, the structural integrity performance criterion was met for the operating period prior to U2R1 9.

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A Document No.: 51-9198837-001 AR EVA Sequoyah U2R19 Steam Generator Inspection 180-day Report Since wear indications will leak and burst at essentially the same pressure, accident-induced leakage integrity at a much lower accident pressure differential is also demonstrated. Operational leakage integrity was demonstrated by the absence of any detectable primary-to-secondary leakage during the operating period prior to U2R1 9.

Since tube integrity was demonstrated analytically, in-situ pressure testing was not required nor performed during the U2R1 9 outage. Likewise, no tube pulls were planned nor performed during U2R1 9.

h. The Effective Plugging Percentage for All Plugging in Each SG There are no sleeves installed in the SQN2 SGs. Therefore, the effective plugging percentage is the same as the plugging percentage shown in Table 2-6. No tubes are plugged, so the effective plugging percentage is 0%.

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A Document No.: 51-9198837-001 AREVA Sequoyah U2R19 Steam Generator Inspection 180-day Report

3.0 REFERENCES

References identified with an (*) are maintained within the TVA Records System and are not retrievable from AREVA Records Management. These are acceptable references per AREVA Administrative Procedure 0402-01, . See the signature page for Project Manager Approval of customer references.

1. AREVA Document 51-9196412-000 "Sequoyah Unit 2 Condition Monitoring for U2R19 and Final Operational Assessment for Cycles 12, 13, and 14"

2.

• Sequoyah Unit 2 Technical Specifications (Administrative Controls), 6.9.1.16.1 "Steam Generator (SG)

Tube Inspection Report", September 26, 2012, Amendment No. 305, 323, 324

3. AREVA Document 51-9198829-000 "Sequoyah U2R19 Steam Generator Degradation Assessment" Page 18