ML14224A576

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SG-CCOE-14-1, Revision 0, Generic Letter 95-05 Tube Intersection Burst Test, Leakage Test, and Morphology Conclusions.
ML14224A576
Person / Time
Site: Beaver Valley
Issue date: 07/31/2014
From: Thomas Magee
Westinghouse
To:
FirstEnergy Nuclear Operating Co, Office of Nuclear Reactor Regulation
Shared Package
ML14224A573 List:
References
GL-95-005, L-14-241 SG-CCOE-14-1, Rev 0
Download: ML14224A576 (88)
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Text

Enclosure C L-14-241 t Test, Leakage Test, and Morphology Generic Letter 95-05 Tube Intersection Burs Conclusions (87 Pages Follow)

Westinghouse Non-Proprietary Class 3 July 2014 SG-CCOE-14-1 Revision 0 Interim Report: Examination of Steam Generator Tubes Removed from Beaver Valley Unit 2 Prepared for the FirstEnergy Nuclear Operating Company 8 Westinghouse

SS 3 WESTINGHOUSE NON-PROPRIETARY CLA LEGAL NOTICE performed by Westinghouse Electric This report was prepared as an account of work Company LLC, nor any pers on acting on Company LLC. Neit her Westinghouse Electric its behalf:

or implied including the A. Makes any warranty or representation, express with respect merchantability, warranties of fitness for a particular purpose or the information contained in to the accuracy, completeness, or usefulness of ratus, method, or process this report, or that the use of any information, appa owned rights; or disclosed in this report may not infringe privately of, or for damages resulting B. Assumes any liabilities with respect to the use od, or process disclosed in from the use of, any information, apparatus, meth this report.

S3 iii WES TING HOU SE NON -PRO PRIE TAR Y CLAS SG-CCOE-14-1 Revision 0 Com pany Prep ared for the FirstEnergy Nuc lear Operating Interim Report: Examination of Steam Generator Tubes Removed from Beaver Valley Unit 2 For Page s Auth or's Nam e Signature I Date All Thom as P. Mag ee TPM(*)

For Pages Veri fier' s Name Signature I Date All J onna M. Parte zana JMP (*)

For Page s Man ager Nam e Signature I Date All Laur en A. T osatto LAT (*2 m

ated in the Electronic Document Management Syste

  • Electronically Appr oved Records Are Authentic Westinghouse Electric Company LLC 1000 Westinghouse Drive Cranberry Township, PA 16066

© 2014 Westinghouse Electric Company LLC All Rights Reserved

iv RECORD OF REVISIONS Revision Date Revision Description 0 July 2014 Original issue July 2014 Record of Revisions Revision 0 SG-CCOE-14-1

v TABLE OF CONTENTS

....................................................... iv Record of Revisions ................................................................

.....................................................v Table of Contents ........................................................................

......................................................... vi List of Tables ........................................................................

....................................................... vii List of Figures ........................................................................

...................................... 1-1

1. 0 Introduction ................................................................................

.................................. 1-1 1.1 Background ................................................................................

....................................... 1-2 1.2 Steam Generator Description ................................................

ination .................... 1-2 1.3 Description of the Beaver Valley Unit 2 Tubes Pulled for Exam

.................................... 2-1 2.0 Sectioning for Leak and Burst Testing ........................................

......................................... 3-1 3.0 Leak Screening ........................................................................

................................. 3-1 3.1 Purpose ........................................................................................

...................................... 3-1 3.2 Sample Preparation ................................................................

..................................... 3-1 3.3 Procedure ................................................................................

.................................. 3-2 3.4 Results ........................................................................................

......................................... 4-1 4.0 Burst Test ................................................................................

................................. 4-1 4.1 Purpose ........................................................................................

...................................... 4-1 4.2 Sample Preparation ................................................................

.................................... 4-1 4.3 Burst Test Procedure ................................................................

................................ 4-2 4.4 Burst Test Results ........................................................................

...................................... 4-2 4.5 Post-Burst Observations ........................................................

....................................... 5-1 5.0 Post-Burst Sectioning ................................................................

........................................... 6-1 6.0 SEM Fractography ................................................................

...................................... 6-1 6.1 Sample Preparation ................................................................

..................................... 6-1 6.2 Procedure ................................................................................

................................ 6-1 6.3 Fractography Depth Profiles ........................................................

................................... 6-2 6.4 Crack Surface Characterization ................................................

.......................................... 7-1 7.0 Metallography of Cracks ........................................................

..................................... 7-1 7.1 Procedure ................................................................................

................................ 7-1 7.2 R19C38 02H ................................................................................

................................ 7-1 7.3 R24C41 02H ................................................................................

................................ 7-2 7.4 R24C41 03H ................................................................................

................................ 7-2 7.5 R24C41 04H ................................................................................

...................................... 8-1 8.0 Conclusions ................................................................................

........................................ 9-1 9.0 References ................................................................................

July 2014 Table of Contents Revision 0 SG-CCOE-14-1

vi LIST OF TABLES

....................... 1-4 Table 1-1: Support Plate Elevations ...............................................................

................... 1-5 Table 1-2: As-Received Lengths ........................................................................

......................... 2-1 Table 2-1: Leak and Burst Test Samples ......................................................

......................... 3-3 Table 3-1: Leak Screening Results ...............................................................

..................... 4-4 Table 4-1: Measurements Before Leak I Burst Testing ....................................

............................ 4-5 Table 4-2: Burst Results and Post-Burst Measurements ...........................

..................... 6-3 Table 6-1: Summary of Burst Opening Depth Profiles ....................................

...................... 7-4 Table 7-1: Defec t Metallography Samples ......................................................

July 2014 List of Tables Revision 0 SG-CCOE-14-1

vii LIST OF FIGURES Figure 1-1: Orientation System Used in the Examination ...................................................... 1-6 Figure 2-1: R19C3 8 Segment 3 Sectioning Diagram ............................................................. 2-2 Figure 2-2: R19C38 Segment 4 Sectioning Diagram ............................................................. 2-3 Figure 2-3: R24C41 Segment 3 Sectioning Diagram ............................................................. 2-4 Figure 2-4: R24C41 Segment 5 Sectioning Diagram ............................................................. 2-5 Figure 2-5: R24C41 Segment 6 Sectioning Diagram ............................................................. 2-6 Figure 2-6: R24C41 Segment 7 Sectioning Diagram ............................................................. 2-7 Figure 4-1: Burst Test Support Simulation ............................................................................. 4-6 Figure 4-2: Burst Pressurization ofR19C 38-3B (02H) .......................................................... 4-7 Figure 4-3: Burst Pressurization ofR19C 38-4B (Freespan) .................................................. 4-8 Figure 4-4: Burst Pressurization ofR24C 41-3B (02H) .......................................................... 4-9 Figure 4-5: Burst Pressurization of R24C41-5B (03H) ........................................................ 4-10 Figure 4-6: Burst Pressurization ofR24C 41-6B (04H) ........................................................ 4-11 Figure 4-7: Burst Pressurization of R24C41-7B (Freespan) ................................................ 4-12 Figure 4-8: Burst Opening at R19C38-3B (02H) ................................................................. 4-13 Figure 4-9: Burst Opening at R19C38-4B (Freespan) .......................................................... 4-14 Figure 4-10: Burst Opening at R24C41-3B (Burst in Freespan, Outside of 02H) ................. 4-15 Figure 4-11: Burst Opening at R24C41-5B (Burst in Freespan, Outside of 03H) ................. 4-16 Figure 4-12: Burst Opening at R24C41-6B (04H) ................................................................. 4-17 Figure 4-13: Burst Opening at R24C41-7B (Free span) ......... :................................................ 4-18 Figure 4-14: Post-Burst Observations on R19C38-3B (02H Region) .................................... 4-19 Figure 4-15: Short Cracks Near the Bottom of the 02H TSP ofR19C 38 (0° Orientation) .... 4-20 Figure 4-16: Short Cracks Near the Top of the 02H TSP ofR19C 38 (0° Orientation) ......... 4-20 Figure 4-17: Short Cracks Near the Bottom of the 02H TSP ofR19C 38 (200° Orientation) ........................................................................................................ 4-21 Figure 4-18: Post-Burst Observations on R24C41-3B (02H Region) .................................... 4-22 Figure 4-19: Shallow Corrosion Partially Obscured by Surface Deposits, Near the 0° Orientation ofR24C 41 02H ............................................................................... 4-23 Figure 4-20: Post-Burst Observations on R24C41-5B (03H Region) .................................... 4-24 Figure 4-21: Shallow Axial Cracks (Marked with Arrows) Near Center ofR24C 41 03H TSP Region (180° Orientation) .......................................................................... 4-25 Figure 4-22: Shallow Non-axial Cracks at Top of R24C41 03H TSP Region (0° Orientation) ........................................................................................................ 4-25 Figure 4-23: Post-Burst Observations on R24C41-6B (04H Region) .................................... 4-26 Figure 4-24: Larger Axial Cracks Near the Centerline ofR24C 41 04H TSP Region, Between 335°-360° ............................................................................................ 4-27 Figure 4-25: Larger Axial Cracks Near the Centerline ofR24C 41 04H TSP Region, Between 315°-340° ............................................................................................ 4-27 Figure 4-26: Example of Shallow Cracks Located Adjacent to the Burst Opening Of R24C41-6B (04H) at the 90° Orientation .......................................................... 4-28 Figure 5-1: Post-Burst Sectioning ofR19C 38-3B .................................................................. 5-2 Figure 5-2: Post-Burst Sectioning ofR19C 38-4B .................................................................. 5-3 Figure 5-3: Post-Burst Sectioning ofR24C 41-3B .................................................................. 5-4 Figure 5-4: Post-Burst Sectioning ofR24C 41-5B .................................................................. 5-5 July 2014 List of Figures Revision 0 SG-CCOE-14-1

viii

.................................. 5-6 Figure 5-5: Post-Burst Sectioning ofR2 4C41 -6B ................................

.................................. 5-7 Figure 5-6: Post- Burst Sectioning of R24C41-7B ................................

.................................. 6-4 Figure 6-1: SEM Photomontage ofR1 9C38 -3B (02H) Burst Opening

.................................. 6-5 Figure 6-2: SEM Photomontage of R24C41-6B (04H) Burst Opening

................................. 6-6 Figure 6-3: R19C38-3B (02H) Burst Opening Dept h Profile ................

................................. 6-7 Figure 6-4: R24C41-6B (04H) Burst Opening Dept h Profile ................

(Near Top End Figure 6-5: Example ofR1 9C38 -3B Burst Opening Fracture Surface

.............................. 6-8 of Crack) ................................................................................

(Center of Figure 6-6: Example ofR1 9C38 -3B Burst Opening Fracture Surface

................................... 6-9 Crack) ................................................................................

(Axial Direction Figure 6-7: OD Surface ofR1 9C38 02H, Adjacent to Burst Opening

............................. 6-1 0 is Horizontal) ........................................................................

................................. 6-11 Figure 6-8: Example ofR2 4C41 -6B Burst Opening Fracture Surface (Axial Direction Figure 6-9: OD Surface ofR2 4C41 04H, Adjacent to Burst Opening

............................. 6-12 is Horizontal) ........................................................................

................................... 7-5 Figure 7-1: R19C38 02H- Overall View ofTra nsver se Section ........

................................ 7-6 Figure 7-2: R19C38 02H Cracks at 200° ................................................

................................. 7-6 Figure 7-3: R19C38 02H Crack at 340° ................................................

................................... 7-7 Figure 7-4: R24C41 02H - Overall View of Transverse Section ........

.................................. 7-8 Figure 7-5: R24C41 02H Cracks at 20° ................................................

................................ 7-8 Figure 7-6: R24C41 02H Cracks at 160° ................................................

................................ 7-9 Figure 7-7: R24C41 02H Cracks at 340° ................................................

................................. 7-10 Figure 7-8: R24C41 03H- Overall View ofTra nsver se Section ........

.............................. 7-10 Figure 7-9: R24C41 03H Cracks at 180° ................................................

................................. 7-11 Figure 7-10: R24C41 04H - Overall View of Transverse Section ........

................................ 7-12 Figure 7-11: R24C41 04H Cracks at 80° ................................................

................................ 7-12 Figure 7-12: R24C41 04H Cracks at 40° ................................................

.............................. 7-13 Figure 7-13: R24C41 04H Cracks at 350° ................................................

.............................. 7-13 Figure 7-14: R24C41 04H Cracks at 335° ................................................

.............................. 7-14 Figure 7-15: R24C41 04H Cracks at 315° ................................................

TSP from Figure Figure 7-16: R24C41 04H Cracks at 350° ,20 mils Further Dow n the

............................ 7-14 7-13 ........................................................................................

July 2014 List of Figures Revision 0 SG-CCOE-14-1

1-1

1.0 INTRODUCTION

1.1 Background Generic Letter 95-05 (GL 95-05)

The U.S. Nuclear Regulatory Commission (NRC) issued to request a license amendment to the (Reference 1) to give guidance to licensees who may wish ate steam generator tube repair plant 's technical specifications in order to implement altern eter stress corrosion cracking criteria (ARC) that is applicable specifically to outside diam in Westinghouse-designed steam (ODSCC) at the tube-to-tube support plate intersections s (TSPs) and alloy 600 steam generators (SGs) containing drilled-hole tube support plate generator tubing.

per GL 95-05 had been approved for For outages prior to EOC-16, the alternate repair criterion implemented. FirstEnergy Nucl ear Beav er Valley Power Station Unit 2 (BVPS2), but was not criterion due to the low number of Operating Company (FENOC) had not implemented the 1 by +Point' to contain axial bobb in indications at TSP intersections that were confirmed 2R16 initial inspection plan did not outside diameter stress corrosion cracking (ODSCC). The was implemented at 2R16 due to an include application ofGL 95-05; however, the criterion (DSis) that were confirmed to contain increase in the number of Distorted Support Indications axial ODSCC.

cation of the GL 95-05 voltage-based The 2R17 outage (Spring 2014) represents the second appli the Beav er Valley Unit 2 SGs. The repair criteria, and implementation of its requirements, to 2.

analysis of the 2R17 outage data is reported in Reference of tube removal for testing and Implementation of the GL 95-05 ARC includes a progr am examination. The purpose of this progr am is to:

anism, (1) confirm axial ODSCC as the dominant degradation mech (2) monitor the degradation mechanism over time, probability oflea kage , and (3) provide additional data to enhance the burst pressure,

, and conditional leak rate correlations described in GL 95-05 (4) assess inspection capability.

laboratory examination, each During the 2R17 outage, FENO C removed two tubes for These tubes were sent to the containing a TSP location with confirmed axial ODSCC.

atory examination.

Westinghouse Churchill Site (WCS) to complete the labor GL 95-05 are as follows:

Reporting requirements for the laboratory examination in tube intersections remo ved from the SG.

The results of metallurgical examinations perfo rmed for a minimum, the burst test, If it is not practical to provide all the results within 90 days, aswithi n 90 days. The remaining ded leakage test and morphology conclusions shou ld be provi ble.

information shou ld be submitted when it becomes availa 1

+Point' is a trademark of Zetec, Inc.

July 2014 Introduction Revision 0 SG-CCOE-14-1

1-2 leakage test and morphology The purpose of this interim report is to provide the burst test, requirement.

results and conclusions to satisfy the 90-day GL 95-05 reporting 1.2 Steam Generator Description nghouse designed pressurized Beave r Valley Unit 2, operated by FENO C, is a three loop Westi commercial operation in water reactor located in Shippingport, P A. The plant commenced Augu st 1987.

heat transfer tubes per steam The Westinghouse Mode l51M steam generators contain 3376 fter Alloy 600) with a nominal generator. The tubes are mill-annealed NiCrFe Alloy 600 (herea ted in 21.25 inches thick low 0.875 inch OD and 0.050 inch wall thickness. The tubes are moun nch thick carbon steel tube support alloy steel tubesheets. The tubes are supported by seven 0.75-i carbon steel flow distribution plates (TSP). Most tubes also pass through one 0.75-inch thick baffle (FDB), which is referred to as TSP# l.

3).

Table 1-1 provides a summary ofthe TSP elevations (Reference ination 1.3 Description of the Beaver Valley Unit 2 Tubes Pulled for Exam examination, based on the 2R17 Two tubes were selected by FENO C for removal and laboratory

s. Both tube selections were outage eddy current examination results and GL 95-05 requirement in the "C" steam generator (SG-C).

n coil Distorted Support The tube at Row 19, Column 38 (R19C38) had a 0.62 volt bobbi tion was confirmed by +Point.

Indication (DSI) at hot leg TSP#2 (02H) location. This indica n coil DSI at its 04H location The tube at Row 24, Column 41 (R24C41) had a 0.47 volt bobbi 02H location that was not that was confirmed by +Point. It also had a 1.19 volt DSI at its confirmed by +Point.

ry side of the tubesheet of SG-C.

Segments from the two tubes were pulled from the hot leg prima and cut into four segments. Tube Tube R19C38 was cut below 03H, pulled through the tubesheet cut into seven segments.

R24C41 was cut below 05H, pulled through the tubesheet and red to the WCS laboratories.

Table 1-2 provides a summary of the segments that were delive nt was provided in its own Reference 4 acknowledges the receipt of the segments. Each segme n and section (segment) number.

individual plastic tube, labelled so as to indicate the row, colum The orientation within the steam generator was also marked.

at about a 45° angle so as to aid in As each segment was pulled through the tubesheet, it was cut small notch was made at the tracing the azimuthal orientation from segment-to-segment. A nt was the bottom and to indicate bottom of most segments to indicate which end of each segme 38, the notch is on the side of an azimuthal orientation reference. For the segments from R19C R24C41, the notch is on the the tube that was closest to the periphery. For the segments from side of the tube that was closest to the manway.

July 2014 Introduction Revision 0 SG-CCOE-14-1

1-3 this bottom end notch.

For the laboratory examination, the orientation system was based on the bottom end of the Segments that did not have a notch were given an identifying mark on The notch was used as the segment, at the same azimuthal orientation as on an adjacent segment.

in the clockwise 0° azimuthal reference point; all other azimuthal orientations progressed for a sketch of the direction while viewing the tube from the bottom end. See Figure 1-1 was transferred to sections that orientation system used in the laboratory. This orientation system le.

were cut from these segments by making a similar mark, where possib of the Beaver Valley Unit In comparison with tubes pulled from other plants, the condition of all fresh outer surface 2 pulled tube segments from SG-C was good. There were relatively few ter reductions were scratches/scrapes on the outer surfaces. No significant bends or diame detected from the pulling operation.

July 2014 Introduction Revision 0 SG-CCOE-14-1

1-4 Table 1-1: Support Plate Elevations Distance Above Tube Mouth (inches)

Location 0

Tubesheet Primary Side I Cladding Surface 0.04 Tube End (recessed for tube-to-tubesheet weld) 0.25 Cladding-to-Tubesheet Interface (nominal, cladding thickness 2': 0.15 inch) 21.47 Top-of-Tubesheet (tubesheet thickn ess= 21.34 I 21.22 inches) 41.55 Center ofTSP #1 (FDB) 71.6 Center of TSP #2 122.1 Center of TSP #3 172.6 Center of TSP #4 223.1 Center of TSP #5 273.6 Center of TSP #6 324.1 Center of TSP #7 374.6 Center of TSP #8 July 2014 Introduction Revision 0 SG-CCOE-14-1

1-5 Table 1-2: As-Received Lengths Tube Segment Region Length (in)

R19C38 1 Tubesheet and Top of Tubesheet 25.9 2 FDB (01H) 31.8 3 TSP (02H) 25.7 4 All Freespan 32.4 1 Tubesheet and Top of Tubesheet 24.5 R24C41 2 FDB (01H) 31.2 3 TSP (02H) 27.7 4 All Frees pan 33.9 5 TSP (03H) 32.9 6 TSP (04H) 32.7 7 All Freespan 35.6 July 2014 Introduction Revision 0 SG-CCOE-14-1

1-6 top elevation forth is segment:;:;>.

look ingtt tBot tom End 0 11 elevation for this segment=>

D 0

Figure 1-1: Orientation System Used in the Examination July 2014 Introduction Revision 0 SG-CCOE-14-1

2-1 2.0 SECTIONING FOR LEAK AND BURST TESTING and burst testing. Samples A total of six samples were cut from the tube segments for leak TSP region along its length. The having a TSP region were cut, as best as possible, to center the ng sectioning diagrams are samples are summarized in Table 2-1 below, and the correspondi P regions are shown as a darker provided in Figure 2-1 through Figure 2-6. The locations ofTS d to the tube segments during color on applicable diagrams. The orientation notch that was applie of the segment. This orientation the pulling operation is shown as a small oval near the bottom t tube, and is shown as a white was transferred to other sections as they were cut from the paren mark.

the appropriate row, column Sections were stored in individual containers, each labelled with with appropriate WCS work and section number. Traceability was maintained in accordance instructions (Reference 5).

The ends of each sample were deburred prior to testing.

Table 2-1: Leak and Burst Test Samples Confirmed ECT Sectioning Leak Burst Indication Diagr am Section Teste d Scree n Test Tube Segment Re_gion 3 TSP (02H) X Figure 2-1 R19C38-3B X X R19C38 4 Freespan Figure 2-2 R19C38-4B X 3 TSP (02H) Figure 2-3 R24C41-3B X R24C41 5 TSP (03H) Figure 2-4 R24C41-5B X 6 TSP (04H) X Figure 2-5 R24C41-6B X X 7 Freesgan Figure 2-6 R24C41-7B X July 2014 Sectioning for Leak and Burst Testing Revision 0 SG-CCOE-14-1

2-2 Section 3C: 5.92" Section 3B: 12.011 02H; 6.0" from bot Section 3A: 7.5" notch Figure 2-1: R19C38 Segment 3 Sectioning Diagram July 2014 Sectioning for Leak and Burst Testing Revision 0 SG-CCOE-14-1

2-3 R19C38- 40: 1" R19C38- 4C: 12u R19C38- 4B: 12" Rl9C38- 4A: 7.2" Figure 2-2: Rl9C38 Segment 4 Sectioning Diagram July 2014 Sectioning for Leak and Burst Testing Revision 0 SG-CCOE-14-1

2-4 Section 3C; 5. 7" Section 3B: 12.0" 02H: 6.0" from bot Section 3A: 9.69" notch Figure 2-3: R24C41 Segment 3 Sectioning Diagram July 2014 Sectionin g for Leak and Burst Testing Revision 0 SG-CCOE-14-1

2-5 Sectton SC; 20.44u Sec\lon SB; 12,0 03H; 4.50" from bot notch Section SA\ 0,19" Figure 2-4: R24C41 Segment 5 Sectioning Diagram July 2014 Sectioning for Leak and Burst Testing Revision 0 SG-CCOE-14-1

2-6 11 Section 6C: 3,56 04H: 6.0" from bot Section 66~ 12.0" Section 6A: 1,6.94" notch Figure 2-5: R24C41 Segment 6 Sectioning Diagram July 2014 Sectioning for Leak and Burst Testing Revisi on 0 SG-CCOE-14-1

2-7 R24C41 -7D; 1" R24C41 -7C: 12" R24C41 -7B: 1211 R24C41 - 7A: 10.5

Figure 2-6: R24C41 Segment 7 Sectioning Diagram July 2014 Sectioning for Leak and Burst Testing Revisi on 0 SG-CCOE-14-1

3-1 3.0 LEAK SCREENING 3.1 Purpose two TSP regions To determine if a leak path had developed through the tube wall, each of the

. Leak screening with confirmed crack-like eddy current indications were screened for leakage screening test does differs from leak rate testing in that there is no measurement of a leak rate. A leak" condition at not provide a leak rate (other than zero); it provides a result of "leak" or "no tes the requirements each pressure tested. Leak screening, rather than leak rate testing, elimina measurements associated with measuring small leak rates. If leakage was identified, leak rate would be conducted.

in the Degradation Each TSP region was pressurized to the pressures identified for in situ testing made if the sample Assessment (Reference 6) using room temperature water. An assessment was leak screening was leaking based on visual observations and the loss of internal pressure. The of TSP was performed without internal bladders or fixtures that simulate the constraints intersections.

3.2 Sample Preparation (02H from In preparation for leak screening, and subsequent burst testing, the two TSP regions s, with the TSP R19C38-3B and 04H from R24C41-6B) were sectioned into 12 inch long sample 2-1 through region centered as well as possible across the length (see Table 2-1 and Figure Figure 2-6). The ends of the samples were deburred after cutting.

after cutting.

The outer diameters (OD) and wall thicknesses of each sample were measured These are presented in Table 4-1.

the equipm ent In addition, a dummy piece was leak screened to check for proper operation of to be workin g properl y and all and for any leakage in the test lines. All equipment was found sample are not sources of leakage from the test lines were sealed. The results of the dummy included in this report.

ed with deionized Swagelok fittings were then affixed to the tube ends and each tube was pre-fill temper ature water to water. One end of each sample had a fitting that allowed pressurized room pass into the sample from a 1/8 inch diameter supply line.

3.3 Procedure instructions Leak screening was conducted in accordance with the appropriate WCS work (Reference 8).

(Reference 7). These work instructions are in compliance with EPRI Guidelines ted pressure Each sample was connected to pressurization equipment, which included a calibra the pressure inside transducer used to measure the internal pressure of the tube, a valve to isolate reading vs. time.

the tube and a data acquisition system for recording the pressure transducer July 2014 Leak Screening Revision 0 SG-CCOE-14-1

3-2 and 50 psi was Axial flaw leak test pressures included a temperature adjustment factor of 1.10 d up to the nearest added for measurement uncertainty. Target test pressures were rounde e differential increment of 25 psi. Three target test pressures were used: normal operating pressur condition (1700 psig), an intermediate test pressure (2250 psig), and steam line break (SLB)

(2875 psig).

(5.0) minutes, Each sample was pressurized to the target pressure of 1700 psig, held for five s, then pressurized to the second target pressure of2250 psig, held for five (5.0) minute include a one-minute pressurized to the final target pressure of2875 psig. The hold times do not hold to allow the test system to stabilize after the pressure had been increased.

leakage. Tissue During each hold period, each sample was periodically observed for signs of tion. Also, the loss of internal pressure paper was pressed against the sample to aid in this observa d during the hold was observed as a second criterion. A loss of 100 psi (maximum) was allowe period to account for system stabilization.

3.4 Results the pressure loss Neithe r sample showed any sign ofleaka ge by either the visual observation or criteria at any pressure. The results are summarized in Table 3-1.

temperature As neither sample with a confirmed eddy current indication leaked during room testing, it was deemed unnecessary to test the samples at an elevated temperature.

July 2014 Leak Screening Revision 0 SG-CCOE-14-1

3-3 Table 3-1: Leak Screening Results Target Start End Pressure Pressure Pressure Leakage Samgle Region (psi g) (psi g) (psi g) Observed 02H 1700 1799 1789 no R19C38-3B 2250 2253 2243 no 2875 2905 2892 no 04H 1700 1743 1719 no R24C41-6B 2250 2335 2315 no 2875 3070 3040 no July 2014 Leak Screening Revision 0 SG-CCOE-14-1

4-1 4.0 BURST TEST 4.1 Purpose sections exceeded The primary purpose of the burst testing was to determine if the degraded tube EPRl Tube the NEI 97-06 requirements on burst strength (Reference 9), implemented by g require ment is that the tube Integrity Assessment Guidelines (Reference 10). The most limitin t burst. 3NOP is must sustain three times normal operating pressure differential (3NOP) withou for room approximately 4446 psid for Beaver Valley Unit 2 at temperature, or 4950 psid temperature testing (Reference 6).

4.2 Sample Preparation long samples, In preparation for burst testing, all four TSP regions were sectioned into 12 inch additio n, a freespan section with the TSP region centered as well as possible across the length. In test samples (see from each tube was also selected to establish a baseline, for a total of six burst Table 2-1). The ends of the samples were deburred after cutting.

after cutting.

The outer diameters (OD) and wall thicknesses of each sample were measured These are presented in Table 4-1.

the equipment. All In addition, a dummy piece was burst tested to check for proper operation of are not included equipment was found to be working properly. The results of the dummy sample in this report.

ed with deionized Swagelok fittings were then affixed to the tube ends and each tube was pre-fill ature water to water. One end of each sample had a fitting that allowed pressurized room temper pass into the sample from a 1/8 inch diameter supply line.

4.3 Burst Test Procedure ce 11 procedure Room temperature burst tests were performed in accordance with the Referen was supplied by a and the Reference 8 EPRl Guidelines. The pressurized water for the burst test a single, piston delivery system. Pressure was increased and supplied to the sample with ly constant controlled stroke of the piston. A feedback loop was used to establish a relative was recorded pressurization rate of20-5 00 psi/second. The internal pressure of the specimen digitally through a data acquisition system and a redundant data acquisition system bladder and The Reference 8 guidelines and the Reference 11 procedure allow an internal a pre-identified backing foil to achieve a successful burst test elevated pressure when there is all eddy current signals leak path from the tube. Since none of the samples had a leak path and and not used.

were relatively small, an internal bladder or foil was judged to be unnecessary e the The TSP regions were laterally restrained by a support system designed to simulat acciden t conditi ons. Figure 4-1 conditions in the Beaver Valley Unit 2 steam generators under d to the top end of shows a sketch of the support system. An unpressurized extension was attache July 2014 Burst Test Revision 0 SG-CCOE-14-1

4-2 several feet to its length.

each sample by a welded cap that both sealed the top end and added simulation while the The top end of the extension passed through a% inch wide support plate simulation. The tube-to-attached test sample passed through anothe r% inch wide support plate support plate simulations support clearance was obtained from the Reference 12 document. The of the TSP region on each were spaced a fixed 50.5 inches apart (see Table 1-1). The centerline t plate simulation to section was positioned two (2.0) inches above the centerline of the suppor g of the tubesheet with conservatively approximate the displacement encountered by the bowin The specimen was tubes that are not locked into their supports during accident conditions.

the specimen with the pressurized through a Swagelok fitting that connected the bottom of pressurization equipment.

The freespan samples were not tested with the support system.

was pressurized to burst, Once each sample was connected to the pressurization equipment, it EPRI Guidelines without hold points, at a rate of20-5 00 psi/second. Section 2.2 of the (Reference 8) provides the acceptance criteria for a burst test.

4.4 Burst Test Results for all of the burst tests.

Figure 4-2 through Figure 4-7 provides the burst pressurization data res were significantly greater than Table 4-2 summarizes the burst test results. All burst pressu

9) and EPRI Guideline the 3NOP criteria of 4950 psig and thus meet NEI 97-06 (Reference (Reference 10) criteria.

within the TSP region, The 02H region ofR19 C38 and the 04H region ofR24 C41 both burst at pressures equal to or both at 9678 psig. The other four samples burst in a freespan region above 10,733 psig. All bursts were axially-orientated.

4.5 Post-Burst Observations the burst test samples.

Table 4-2 presents a summary of the post-test measurements made on Tearing was confirmed at Figure 4-8 through Figure 4-13 present photos ofthe burst openings.

with Reference 8 criteria) all burst tips, by microscope, for all six samples, thus (in accordance ofR19 C38 and the 04H each burst test was considered to be a valid burst test. The 02H region ary cracks outside of region ofR24 C41 (Figure 4-8 and Figure 4-12, respectively) show second d no evidence of any the burst opening; the freespan bursts of the other four samples showe cracks.

its entire circumference in Each burst test sample was viewe d under a stereomicroscope around vicinity of any freespan the vicinity ofthe burst. No corrosion or cracks were observed in the burst.

stereomicroscope around its Each burst test sample with a TSP location was also viewed under a observed in all four TSP

  • entire circumference in the vicinity of the TSP region. Cracks were ed. One TSP region had regions of various depths and numbers. Cellular cracking was not observ July 2014 Burst Test Revision 0 SG-CCOE-14-1

4-3 as a region of short axial marginally-discernable OD corrosion that was difficult to distinguish of a TSP region.

cracks or intergranular attack (IGA). Cracking was not found outside fication) to identify the Each TSP region was viewed under a stereomicroscope (up to 20X magni to show location and location of cracks, corrosion or other features. These were mapped out to provide qualitative extent, such as that shown in Figure 4-14. The features were photographed the axial direction as documentation of the feature. In this section, each photo is oriented with horizontal and the bottom side of the view to the left side of the photo.

of the burst was The 02H TSP region of tube R19C38 burst in the TSP region. The center openin g extend ed above and skewed about 0.2 inches above the TSP centerline and the burst were several regions of below the TSP region. The burst occurred at the 350° orientation. There were located near the short (<0.15 inch) axial cracks around the circumference, most of which these short cracks can be burst opening. These are shown in the Figure 4-14 diagram. Some of in Figure 4-15, Figure 4-16 seen near the burst opening as shown in Figure 4-8; others are shown and Figure 4-17.

a region ofmar ginall y-The 02H TSP region of tube R24C41 did not have a burst. There was e deposits, and was either a discernable (shallow) corrosion that was partially obscured by surfac w corrosion that was patch of short axial cracks or IGA. It also had another region with shallo m and in the Figure 4-19 discernable as axial cracks. These are shown in the Figure 4-18 diagra photo.

two regions with shallow The 03H TSP region of tube R24C41 did not have a burst. There were 4-21 shows the shallow cracks. These are shown in the Figure 4-20 diagram. The photo in Figure arrows. Figure 4-22 shows axial cracks located near the 180° orientation, as indicated by the two tion. These cracks are neither the shallow cracks at the top of the TSP region near the 0° orienta and shallow depth.

axial nor circumferential, which may be attributable to their short length of the burst was The 04H TSP region of tube R24C41 burst in the TSP region. The center and below the TSP region.

aligned with the TSP centerline and the burst opening extended above of small axial cracks The burst occurred at the 90° orientation. There were several regions line of the TSP region.

around the circumference, most of which were located near the center and 360°, all within the There was another region oflarg er axial cracks, located between 315° shown in the Figure 4-23 center third (0.25-inch long) portion of the TSP length. These are

. These cracks are diagram. Figure 4-24 and Figure 4-25 show the region of the larger cracks cracking adjacent to the significantly oriented in the axial direction. Figure 4-12 shows some burst opening; Figure 4-26 shows a closer view of these cracks.

July 2014 Burst Test Revision 0 SG-CCOE-14-1

4-4 Table 4-1: Measurements Before Leak I Burst Testing Tube R19C38 R19C38 R24C41 R24C41 R24C41 R24C41 Section 3B 4B 3B 5B 6B 7B Region 02H Freespan 02H 03H 04H Freespa n Length (in) 12 12 12 12 12 12 02H midspan 02H 03H 04H midspan Location of OD Measurements OD (0°-180°) (in) 0.876 0.876 0.873 0.879 0.880 0.873 OD (90°-270°) (in) 0.876 0.876 0.869 0.880 0.876 0.874 Location of Wall Thicknesses bottom bottom bottom bottom bottom bottom 0° (in) 0.056 0.056 0.054 0.056 0.057 0.052 90° (in) 0.060 0.058 0.055 0.056 0.057 0.056 180° (in) 0.057 0.053 0.055 0.057 0.056 0.055 270° (in) 0.054 0.055 0.057 0.055 0.057 0.057 OD and wall thickness measurements may include deposit thickness.

July 2014 Burst Test Revision 0 SG-CCOE-14-1

4-5 Table 4-2: Burst Results and Post-Burst Measurements Tube R19C38 R19C38 R24C41 R24C41 R24C41 R24C41 Section 3B 4B 3B 5B 6B 7B Regio n 02H Freespan 02H 03H 04H Freespan Burst Pressure (psig) 9,678 10,983 10,741 10,733 9,678 10,770 Burst Orientation axial axial axial axial axial axial 100 99 98 99 99 97 Avg. Pressurization Rate (psi/sec) an Location of Burst 02H free span freespan free span 04H freesp 6.20 4.91 8.20 7.73 6.00 5.29 Center ofBur st, inches above bottom 350° 310° 315° 220° 90° 240° Azimuthal Location of Burst 1.20 1.91 1.42 1.83 1.28 1.82 Length of Burst Opening (in) 0.33 0.38 0.32 0.36 0.33 0.41 Width of Burst Opening (in) 1.180 1.249 1.309 1.265 1.102 1.285 Maxim um Diameter (in) 1.066 1.103 1.154 1.129 1.076 1.137 Diameter, 90° from Maxim um (in)

July 2014 Burst Test Revision 0 SG-CCOE-14-1

4-6 Upper TSP simulation Screws ... _m~

I II Hose clamp (affixed to extension to serve as a stop on the upper TSP simulation)

.Extension Pipe 50.5" Swagelok fitting welded to extension

\., I Sped men ~

TSP region on specimen 1 _J_

Lower TSP simulation (tube moves freely)

Screws ~

\.

-r---

Swagelok fitting that allows water entry Source of pressure ...... tl 2.0" L Threaded rod. to help ln positioning of lower TSP during set-up Figure 4-1: Burst Test Support Simulation July 2014 Burst Test Revision 0 SG-CCO E-14-1

4-7 Beaver Valley 2, Tube R19C38-3B 06/24/20 14 12000 ,------- -------- -------- -------- -------- -------- -------- -------- -------- --

10000 "-----------.. ***-**----******--*-******-*"-*******--*---*--*-------*--*----"*--*-***--------~'-**. ********"*. ~--------~*--**"*--******---. *----------*

aooo ~-------------------------------------~-------r-----------------

-1:11)

-0.

!!! 6000

I 5500- 9000 psig

~

Q) 0:

.1* --*-**------------------*---

4000 o*---""""--* ------------ ------.. ~

1000-5400 psig 20001-------~~--------------------------~------------------

0 -~----~--------~------~------~--------,-----~~----------

20 40 60 80 100 120 140 160 0

Time (seconds)

Figure 4-2: Burst Pressurization ofR19C38-3B (02H)

July 2014 Burst Test Revision 0 SG-CCOE-14-1

4-8 Beaver Valley 2, Tube R19C38-4B 06/24/201 4 12000 ' ----~~ ~~~~~-~--~~~--------- ~**~ .. ~~~~~~~~~--------

10,983 psig 100 00 ~---~~~~-*-~--~-~*~------ **~---~*~--~*--***--~*~*~~**---------~-*---------***~~~-~*----**~~~~~~~ ----------~~~~~~*-----*--~--*~-*-~-- ....*-~------------ ~-~~.~--~*-. * - - - - *.........;;.:---*-*---~*1-----*------------*. -*

8000 ------*-~-----*---- . . . ----------- *--# *----1----- *-*-*---

-1).1) 92psi/s 5500 -10000 psig

-Q.

....:sQ) 6000 -----------------------------~---------------------------r-------

VI VI Q)

Q:

4000 r-------------------------~~----------------------------------r----------

105psifs SOD- 5400 psig 2000 + _, 1------

0 ~* . ~** . ..,

0 20 40 60 80 100 120 140 160 Time (seconds) Il Figure 4-3: Burst Pressurization ofR19C38-4B (Freespan)

Burst Test July 2014 SG-CCOE-14-1 Revision 0

4-9 Beaver Valley 2, Tube R24C41-3B 06/24 /2014 12000 .,-,- - - - - - -

  • 10.,741psi g 1 0000 +*-***-----------........................- ..........................,....._,.____,___. _____________,,...................,........._,____,,_,,_,________

~

8000 ~----- --*M*----- -*--- ,_,,,,,, ......... *- *------...

-Q l)

Vi c..

Q,)

l 6000 Q,)

Q,.

4000 2000 1 ~

0 -;- =

60 80 100 120 140 160 0 20 40 Time (seconds}

Figure 4-4: Burst Pressurization ofR24C41-3B (02H)

July 2014 Burst Test Revision 0 SG-CCOE-14-1

4-10 Beaver Valley 2, Tube R24C41-5B 06/24/20 14 12000 '

10,733psig

  • -'-'-'"-'~

10000 +*~*,--~---*-.,,,,,_,_,,_,,,,,,,,,.,,,,_,_,,,,,.,,_,__,_,_,,,,_,_,_,_,,,_,.,.,,M,M-<*O--"""'''''''*****'"'"-"''''**'*'"'"'"-'"~---~*-**

800 0 f-.....-------*--*-**-*..**--*-*----*-*-*-*- ---*-*----..--- ----*-----JIII'C *I -----..- - - - - * - - - - -

-Q.O 91 psi/s s5oo -1oooo psig

-Q..

~

~

VI 6000 +----' --- {----- ----

Ill

<1.1 0..

4000 ~---------------------------------~~-----------------

105psifs 1000-5400 psig 2000 1!--------~~------------------------------------~

0 ~~~--~------~------~--------~------~------~--~--~-------

0 20 40 60 80 100 120 140 160 Time (seconds)

Figure 4-5: Burst Pressurization ofR24C41-5B (03H)

July 2014 Burst Test Revision 0 SG-CCOE-14-1

4-11 Beaver Valley 21 Tube R24C41-6B 06/24/2 014 12000 ,,------ ------- ------- ------- ------- ------- ------- ------- -------

~--------------

10000 +-----------------------------------------------------~~

8000

-0.0

  • v;

-c.

11)

J 6000

<I)

<I) 11)

Q.

4000 106psi/s 1000 - 5400 psfg 2000 +---~-------,ttf'.*

0 cc===

20 40 60 80 100 120 140 0

Time (seconds)

Figure 4-6: Burst Pressurization ofR24C41-6B (04H)

July 2014 Burst Test Revision 0 SG-CCOE-14-1

4-12 Beaver Valley 2, Tube R24C41-7B 06/24/201 4 12000 .-

10~770 psig 10000 +---~**----------***----****-* ********-------***** --------*--***-------*------**-**********--*-***** ****--***-----*----***-------~/

8000 +-**-- *****--*********-**-***----*****--***--*-**-*-**-**----*--* **-******-*-****-**---**- -/-****----*------****** **--*--*---1---**--**-* *

-~

89psi/s 5500 -10000 psig VI a.

a> 6000

s VI VI a>

Q.

4000 I

I / 105 psi/s l000-5400 ps1g .

/

2000 0~~~--~--~--~--~~--~--~--- 20 40 60 80 100 120 140 160 Time (seconds)

Figure 4-7: Burst Pressurization ofR24C41-7B (Freespan)

Burst Test July 2014 SG-CCOE-14-1 Revision 0

4-13

-~

~

~

--~

Figure 4-8: Burst Opening at R19C38-3B (02H)

Burst Test July 2014 SG-CCOE-14-1 Revision 0

4-14 Figure 4-9: Burst Opening at R19C38-4B (Freespan)

July 2014 Burst Test Revision 0 SG-CCOE-14-1

4-15

  • J~~<:

Figure 4-10: Burst Opening at R24C41-3B (Burst in Freespan, Outside of02H)

July 2014 Burst Test Revision 0 SG-CCOE-14-1

4-16 Figure 4-11: Burst Opening atR24C41-5B (Burst in Freespan, Outside of03H)

July 2014 Burst Test Revision 0 SG-CCOE-14-1

4-17

~ _,

Figure 4-12: Burst Opening at R24C41-6B (04H)

Burst Test July 2014 SG-CCOE-14-1 Revision 0

4-18

__.-7 Figure 4-13: Burst Opening at R24C41-7B (Freespan)

Burst Test July 2014 SG-CCOE-14-1 Revision 0

4-19 1 =axial crack Burst=350..

Burst Tip TSPTop ---------------- -------:-------- -------------- L____ -------------------1----------

.I ----7~--~~-~

I Ill I I

I I

TSP center -----------------------~----------------------r-----------------------1-------------------.,

I I

I I i, I t I 111 p I I

[IIJ I
1f I

11tr 1 11 11 TSP Bot ----------------------*-T-------

1

rI t

t

~-

I I I

Burst Tip I I oo 90.. 180.. 270° 360° Figure 4-14: Post-Burst Observations on R19C38-3B (02H Region)

Burst Test July 2014 SG-CCOE-14-1 Revision 0

4-20

-E- Axial ~

tation)

Figure 4-15: Short Cracks Near the Bottom of the 02H TSP ofR19 C38 (0° Orien

-E- Axial ~

tation)

Figure 4-16: Short Cracks Near the Top of the 02H TSP ofR19C38 (0° Orien July 2014 Burst Test Revision 0 SG-CCOE-14-1

4-21

~Axial ~

Figure 4-17: Short Cracks Near the Bottom of the 02H TSP ofR19C38 (200°0rientation)

July 2014 Burst Test Revision 0 SG-CCOE-14-1

4-22

,f:t.

I= shallow axial cracks ,:;:;" =very shallow IGA/ short axial cracks TSP Top  : \ ~;: 1 t

J l t' l 1' ~ ~ i

  • l ~ t t
t. 1 t 1 .J ~ ** l t.

1 1 1 1 1 1

! 1 ill t**'* *** * *, t t t )- t frt'

-: l:.: j! .; 1:.: l: ~

1

  • l t J 1 '1 1 t I 1 1
t. t: t: l: t:

1 l t l' l

1 t J l: l: t: t: t: .: ~ J!

~: I: I~ ~  :  : J t t 1 1 1 1 I ' iti:tttitt 1 t 1 1 1 1 t a't 1i t t l t t 1 1 l t! t t i l: t 1 J :1

~ ~ J I I

~ l ~.! 1: l! 1~ J: l~f.: t

1: t: 1:

1 J t .f J i f

t * ,*t*-~:tttftifftltl!

t.ll!fltt t t t t 1 1 ( t It IT I l l 1 f I~

~ t l t 1t i t!t!f:  :

  • I
t  : t:I*:1:J:t:t:t:l:i:

It * .f.! :t lt!1 (It i tlt l: 1!.: r: I~ l: t! I:

I

~~ Jlf,

I:~:

I

:  : t 1 tltflltfiJ1llJ1 t
::------------------- -----r----------------------r-- --------------------- ~------------*::: :::::: ~:: :~: ::

I I l

1 tJ:t TSP center I I t I l i t* t t t 1 1

f t 1

~ I I I *'**ili:t1 A 1 tl1li 1 4 t If 11 if it 1 :f .t: l I f ~ ) l l

~ l. il

~t:~

't I

1 I I

'  :. t*:*~*:,:*~*:*~l:f

~ *t J ~ l l l t l l . f t J I t 1' t t i l' f t t t f 1t 1 :r. l **** .f

~ 1 * :t: '

(

1 i I J t l J ttl f t .J

  • t tAt t ~

k l t :t I

~ t *1 t l: f 1 f 1*1 t* f1l t

~t lf 1 I 1 l l J t J't t t t - l I

I l I

, I t f l tlttlJtJll-t! ** 't't f;IJit I * ' ~ t rtf~* s t, :r t * .~ t t J

~ 1 tlJ

-*~l I ~

t

~

)f l 1) t I 'lt *i t

f t

t t * *~t*t*~~*

1 J t I 1 I :J t J t t f f 1' 1 It i J ~f) t l ll t

't

~I~ If f: ~ ~ t:

  • t t t i t i t 't t.

l I t :t t I l t l; t : t a~: l!

t i

  • i ~I l I t

I 1 f I 1 t t l-

' a~ t ~ t I I t 1 l ~ l fIt f J f ~ t TSP Bot 0"' 90"' 180"' 270"' 360"'

Figure 4-18: Post-Burst Observations on R24C41-3B (02H Region)

July2014 Burst Test Revision 0 SG-CCOE-14-1

4-23

-E- Axial ~

Figure 4-19: Shallow Corrosion Partially Obscured by Surface Deposits, Near the 0° Orientation ofR24C41 02H July 2014 Burst Test Revision 0 SG-CCOE-14-1

4-24 I =shallo w crack TSP Top /J-

t ------------------ - r----- ------------------1----------------------

j TSP center I

I 1I I

t I

I I

I t TSP Bot oo 90° 180° 270° 360° Figure 4-20: Post-Burst Observations on R24C41-5B (03H Region)

July2014 Burst Test Revision 0 SG-CCOE-14-1

4-25

~Axial ~

03H TSP Figure 4-21: Shallow Axial Cracks (Marked with Arrows) Near Center ofR24 C41 Region (180° Orientation)

~ Axial -7 ation)

Figure 4-22: Shallow Non-axial Cracks at Top ofR24C41 03H TSP Region (0° Orient July 2014 Burst Test Revision 0 SG-CCOE-14-1

4-26 Series of axial cracks, along cente r Burst=90o third of TSP region , from 315° - oo Burst Tip TSPTop -----------------------*----------------------r-----------------------,-----------*----------

1 i

,*,t  ;

I .

~~::-----------~~;- -t~-----------------t-----------------~-1~-----------ti-~-li-~

t TSP cente r I

I 1,1 I I

I I

11t 1 I TSP Bot ----------*--------*-----------------~---------------:----------------------

1 Burst Tip oo 900 180° 270° 360° I

Shallo w axial cracks Figure 4-23: Post-Burst Observations on R24C41-6B (04H Region)

July2014 Burst Test Revision 0 SG-CCOE-14-1

4-27

<E- Axial ~

Between Figure 4-24: Larger Axial Cracks Near the Centerline ofR24C41 04H TSP Region, 335°-360°

<E- Axial ~

Between Figure 4-25: Larger Axial Cracks Near the Centerline ofR24C41 04H TSP Region, 315°-340° July 2014 Burst Test Revision 0 SG-CCOE-14-1

4-28

--E- Axial ~

Burst Opening Figure 4-26: Example of Shallow Cracks Located Adjacent to the Burst Opening OfR24 C41-6B (04H) at the 90° Orientation July 2014 Burst Test Revision 0 SG-CCOE-14-1

5-1 5.0 POST-BURST SECTIONING ng Electron Following the completion of the burst tests, samples were sectioned for Scanni Figure 5-6 Microscope (SEM) fractography and defect metallography. Figure 5-l through

, the circled "A" and "B",

provide sketches of how each sample was sectioned. In each diagram

. These cuts and the adjacent dotted line, represent the cuts that were made within the section ble).

were made in order of the "A" cut first and the "B" cut second (where applica July 2014 Post-Burst Sectioning Revision 0 SG-CCOE-14-1

5-2 rranwerl;.t ~:19(~J1,.,:J.Bl~ t2:'1 ~:see d!!ti!>ili::td fflil;tl for r.:U1iiteeirh more tutsl bt;rr!!<t 1lP 382C:

  • Arthfve TSP Top

'3B2C TSP center 3B2;.\

B TSP Bot Eh.Jrst Tip 0" 90 180" 270" 360" 13lJ rs.t;::::3 50"'

A

'3B2A,; 1~1J1l

'" SEM  : " Defect Metallogr.a p hy Figure 5-1: Post-Burst Sectioning ofR19C 38-3B July 2014 Post-Burst Sectioning Revision 0 SG-CCOE-14-1

5-3 II a*1:;>*n!r'Se

~\.il in i!w:h bUr"~ tip

'4B2B:

.., Archive Burst Tip 4B2B 4132A Burst Tip 27{1" 360" A

4B2A:

  • SEM Depth Profile Figure 5-2: Post-Burst Sectioning ofR19C 38-4B July 2014 Post-Burst Sectioning Revision 0 SG-CCOE-14-1

5-4 fl'i;~"IS'tl!rS*~

r:ue at !!JL'h bUI'it tlf1!

r~1fl1i!llr~i1pt!Y l*lli **441!~~ hl ~llYA' 'lll~A' !If LLl! .J! ~':OP shr1iin\*** cr.n:k!k re*ntorhnrr jt.r;l !h!JIIi!ij' !~!'

t>;<Htllri!Ht:' laci

!7r)" and Jt5' l!J'I 1

3848:

!* Archive A

Burst: Tip

3B4B 3B-4A Burst Tip 0"'; 90" 180" 360" Burst~315" A

3B4A~

  • SEM Depth Pronle Figure 5-3: Post-Burst Sectioning ofR24C 41-3B July 2014 Post-Burst Sectioning Revision 0 SG-CCOE-14-1

5-5 lri¥H!:.!rm:Jt:

o.lt ilt ,,:;:u::n ll'.Jr~ hJI Mt:!~;t~ll.:)!lFi!Pit~

'1mn~l:it::l:>e ,Cl ~hoo'J *Jk'W pf cui 111 TSP iih;Jltr..v,il,i i.:!&:rtk!l:

t:Cflf,IH!inr< rll~l behlW TSP

  • ~l!f'ltl1rlinn li11t llli.l'r SB4B;
  • Archive Burst Tlp SB4B Borst Tlp 0"

Burst=2ZO A SB4A:

  • .- SEM Depth Profile Figure 5-4: Post-Burst Sectioning ofR24C 41-5B July 2014 Post-Burst Sectioning Revision 0 SG-CCOE-14-1

5-6

~i-an!iV~cse Hi4C*H {itl.l; l,~:fl"  !"lrw r~!~lilitJt~rl fl!l~fl fnr

(~IJ~ ,;~f ct:v.:h !ltCII ~ tl.lt~:~

burst tl~

6B2A 6828 TSP Bot

~~- -~~ w-'-~'-"'-"'~'~---** ~~ _.,_. ---~--~*-;

--*-c- -- ---~--" !*~-~-_____. ,,.__ ______,_,~~---*~ "* --~~

<0-

    • ~*

Burst Tip ,_ ~~-*--~-~*-----*-'-" ,_.. ,....,*-~*-'-" ---~-

I 0" 90" i 180" 270° 360" Burst=90" AI 682A:

  • SEM *6B2B:
  • Defect Metallography Figure 5-5: Post-Burst Sectioning ofR24C41-6B July 2014 Post-Burst Sectioning Revision 0 SG-CCOE-14-1

5-7 Tr;ms,*~r*r.o i:'4lt ,;"It !'::::lth ll<ll~'!t tlfl 1124D11*7Ul,, '-.~.1':1~

7B2B
A I* Archive Burst Tip 7826 7B2A Burst Tip 0" 270., 360" A Burst=240

,7B2A:

  • SEM Depth P~ofile Figure 5-6: Post-Burst Sectioning ofR24C41-7B July 2014 Post-Burst Sectioning Revision 0 SG-CCOE-14-1

6-1 6.0 SEM FRACTOGRAPHY 6.1 Sample Preparation in the A 12-inch wide sample was cut from the right side of each burst opening, as was depicted

. Each diagrams of Section 5.0. The cuts were made so as to include both tips ofthe burst opening of dry oil-free sample examined by Scanning Electron Microsc opy (SEM) was blown with a jet e

air to minimiz e non-conductive particulates from the fracture surfaces that would otherwis collect an electrical charge (and thus hinder the view) during the SEM examina tion.

6.2 Procedure A

Observations made during the SEM examina tion were documented with micrographs.

for the fractogr aphy examina tion.

TESCA N LYRA Scanning Electron Microsc ope was used d

Operatio n of the SEM followed the manufac turer's instruction. ASTM has not publishe surfaces examine d by SEM in accorda nce procedu res for fractography examinations. Howeve r, fractogr aphs with accepted scientific principles and EPRI guidelines can be compare d with presente d in various fractography textbooks, such as "Metals Handbook, Volume 12, Fractog raphy," 9th Edition, America n Society of Metals, 1985.

SEM fractographs were taken of the entire fracture surface of each burst opening. These fracto graphs were then aligned end to end to complete a photomo ntage of each crack surface.

depth of The photomo ntage was obtained using the back-sca ttered electron SEM detector. The the corrosion was measure d at selected intervals, providin g a set of depth vs. axial location the measurements. The depths were converte d to percent throughwall (% TW) values by dividing depth measure ment by the nominal wall thicknes s of 50 mils.

the crack Fracto graphs were taken of selected locations at higher magnifications to characterize detector.

morphology. Crack characterization was perform ed using the secondary electron SEM 6.3 Fractography Depth Profiles have no The four burst openings that occurred in regions of freespan tubing were confirmed to corrosion. The remaining two burst openings that occurred on the TSP regions in section No R19C38 -3B (02H) and R24C41-6B (04H) both had corrosion within each TSP region.

corrosio n was observed outside of a TSP region.

lower Each burst opening was cut from its tube so as to include both the upper burst tip and the magnifi cation views of the burst tip in the same sample. Figure 6-1 and Figure 6-2 show low burst opening fractography photomontages for R19C38 -3B (02H) and R24C41-6B (04H),

some respectively. Because of the length of each image, the photomo ntage was split in two with and the overlap. The top of the burst opening is shown in the upper end of the left photomo ntage bottom of the burst opening is shown in the lower end of the right photomontage.

Figure The depth profiles of the cracks in these two burst openings are shown in Figure 6-3 and of the burst 6-4, respectively. Crack depth measurements were taken along the axial direction July 2014 SEM Fractography Revision 0 SG-CCOE-14-1

6-2

, located at opening, starting at the lowest elevation of the burst opening (bottom of the sample n, to the the bottom tip of the burst opening) and proceeding up the tube, in the axial directio ement was obtained upper tip of the burst opening. Figure 6-1 shows how one crack depth measur at the indicated distance from the bottom of the sample.

8-3B (02H)

Table 6-1 provides a summary of the depth profiles for the burst openings. R19C3 had a had the deepest corrosion, at 49.9%TW. The burst opening ofR24C 41-6B (04H) maxim um depth of corrosion of 48.6%TW.

6.4 Crack Surface Characterization opening. The Figure 6-5 presents an example of the crack surface of the R19C38-3B burst of the tube wall surfaces having the rock candy appearance is intergranular cracking - the part

- the part of the that occurred during in-service operation. The dimpled surface is ductile tearing of the fracture tube wall that failed during the burst test. Figure 6-6 presents another region opening .

surface with intergranular cracking. These surfaces are typical of the burst view, the axial Figure 6-7 shows the OD surface ofR19C 38 02H near the burst opening. In this cracks with direction is horizontal. This fractograph montage shows several secondary axial (IGA). All of the secondary some minor branching and a small patch ofinter granula r attack on cracking cracks are intergranular. This surface is typical of axial OD initiated stress corrosi (ODSCC).

. The fracture Figure 6-8 shows an area on the crack surface ofthe R24C41-6B burst opening ductile tearing. The surface consists ofinter granula r cracking (the rock candy topography) and

. This example is figure shows a higher magnification view of the inter granular fracture surface typical of the burst opening fracture surface.

view, the axial Figure 6-9 shows the OD surface ofR24C 41 04H near the burst opening. In this cracks and some direction is horizontal. This fractograph montage shows several secondary axial ODSCC.

patches of shallow intergranular attack (IGA). This surface is typical of axial e of transgranular The corrosion observed on all surfaces was intergranular; there was no evidenc cracking.

July 2014 SEM Fractography Revision 0 SG-CCOE-14-1

6-3 Table 6-1: Summary of Burst Opening Depth Profiles Section Region of Burst Crack Length (in) Maxim um Depth (%TW)

Rl9C3 8-3B 02H 0.702 49.9 Rl9C3 8-4B Freespan 0 0 R24C41-3B Freespan 0 0 R24C41-5B Frees12_an 0 0 R24C41-6B 04H 0.270 48.6 R24C41-7B Freespan 0 0 July 2014 SEM Fractography Revision 0 SG-CCOE-14-1

6-4 Top of Burst Opening

= 1000 ~tm = scale ---*

Crack Depth e Above Bottom of Sample Bottom of Burst Opening Figure 6-1: SEM Photomontage ofR19 C38-3 B (02H) Burst Opening July 2014 SEM Fractography Revision 0 SG-CCOE-14-1

6-5 Top ofBurs t Opening

\ = 500 ~tm = scale ----+

Bottom of Burst Opening Figure 6-2: SEM Photomontage ofR24C41-6B (04H) Burst Opening July 2014 SEM Fractography Revision 0 SG-CCOE-14-1

6-6 ro.o.--- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------- -------

~D i------------------------------------~------------------

40.0 .l ..& i

~

..c ----------------------

"ll. 30.0 I f"' I I H'-+----------------::--A'""-H-------+-------------

(!J c

~

u m

a

  • l-** **---....... -t-*-***------- ......._..........._ ********---- *---*-----

20.0 +-¥--

10.0 -!i-ll---

o.o L_J-_Jll---Ui---==.-

0 200 400 roo

--!.--:~--.--~~~~~--~

800 1000 1200 1400 Distance Above Bottom ofSample (mils.)

Figure 6-3: R19C38-3B (02H) Burst Opening Depth Profile July 2014 SEM Fractography Revision 0 SG-CCOE-14-1

6-7 60.0 50.0 40.0

~~

~

~'

£.

-a 30.0

....a e" 4

~*

u

,1, 20.0

~0.0

~ I 0.0 0 200 400 600 800 1000 1200 ~400 Distance Aoove Bottom of Sample {mils}

Figure 6-4: R24C41-6B (04H) Burst Opening Depth Profile SEM Fractography July 2014 SG-CCOE-14-1 Revision 0

6-8 Intergranular Cracking ("Rock Candy" Surface) Intergranular Cracking ("Rock Candy" Surface)

Figure 6-5: Example ofR19C38-3B Burst Opening Fracture Surface (Near Top End of Crack)

July 2014 SEM Fractography Revision 0 SG-CCOE-14-1

6-9 Figure 6-6: Example ofR19C38-3B Burst Opening Fracture Surface (Center of Crack)

July 2014 SEM Fractography Revision 0 SG-CCOE-14-1

6-10 Figure 6-7: OD Surface ofR19C3 8 02H, Adjacent to Burst Opening (Axial Direction is Horizontal)

July 2014 SEM Fractography Revision 0 SG-CCOE-14-1

6-11 Figure 6-8: Example ofR24C41-6B Burst Opening Fracture Surface July 2014 SEM Fractography Revision 0 SG-CCOE-14-1

6-12 Figure 6-9: OD Surface ofR24C4 1 04H, Adjacent to Burst Opening (Axial Direction is Horizontal)

July 2014 SEM Fractography Revision 0 SG-CCOE-14-1

7-1 7.0 METALLOGRAPHY OF CRACKS 7.1 Procedure 7-1 summarizes One transverse section was taken from each of the support plate regions. Table the defect metallography samples.

ection. Each The metallographic samples were mounted in epoxy to show the cracks in cross-s polishing oil, mounted sample was ground with SiC papers, followed by diamond wheels using mirror finish.

followed by diamond aerosol sprays, leaving the edge to be examined with a The electrolytic Samples were then examined and photographed after an electrolytic Nital etch.

boundaries.

Nital etch was used to highlight the relationship between the cracks and the grain 7.2 R19C38 02H from the 02H TSP Figure 7-1 shows a view of a transverse cross-sectional sample (3B2B) taken 5-1 sectioning ofR19C 38. The gap in the circumference is the SEM sample (refer to the Figure

'2' mark in the figure.

diagram). The left side ofthe burst opening is just to the left ofthe g, that showed At this elevation of the TSP, there were only two areas, other than the burst openin The ' 1' marker is any sign of corrosion; these are indicated by the number markers in Figure 7-1.

and Figure where the cracks at the 200° azimuthal location were identified (see Figure 4-14 n (see Figure 4-17). The numbe r '2' marker is associated with the cracks near the 340° locatio the 280° location 4-14). Cracks near the 0° location are on the SEM sample and the cracks near were very short and were not captured in this cross section.

have been widened Figure 7-2 shows a closer view ofthe cracks at the 200° location. The cracks t signs ofiGA by the swelling of the tube during the burst test. Cracking is intergranular withou As these initiate from the outer and are thus intergranular stress corrosion cracks (IGSCC).

break the OD surface, they are also ODSCC. The figure shows several cracks, two of which r elevation that is surface at this elevation and two cracks which break the OD surface at anothe not shown in this view. The deepest of these (the middle crack) is 25.7%TW.

opening. The Figure 7-3 shows a crack at the 340° location, as well as the left side ofthe burst 27%TW at 340° crack is 22.9%TW and the crack depth of the burst opening is approximately the OD surface at another this elevation. The figure also shows two other cracks which break elevation that is not shown in this view.

7.3 R24C41 02H the 02H TSP of Figure 7-4 shows a view of a transverse cross-sectional sample (3B2) taken from is shown. The R24C41. As the burst occurred outside of the TSP region, the entire circumference "0" that is inside the tube corresponds with the oo location (since the view is in the down

n. This elevatio n was direction, azimuthal locations proceed in the counter-clockwise directio corrosion on both chosen to show the cracks at about the 170° location and the patch of shallow at about 20°, the '2' sides of 0° (see Figure 5-3 and Figure 4-18). The' 1' marker is located marker is at about 160° and '3' marker is located at about the 340° location.

July 2014 Metallography of Cracks Revision 0 SG-CCOE-14-1

7-2 shallow axial ODSCC, without Figure 7-5 shows the 20° location of Marker '1 '. It shows two any IGA. The maxim um depth shown is 11.3%TW.

shallow axial ODSCC, witho ut Figure 7-6 shows the 160° location of Marker '2'. It shows three any IGA. The maxim um depth shown is 14.2%TW.

shallow axial ODSCC, witho ut Figure 7-7 shows the 340° location of Marker '3'. It shows two any IGA. The maximum depth shown is 10.7%TW.

7.4 R24C41 03H e (5B2) taken from the 03H TSP of Figure 7-8 shows a view of a transverse cross-sectional sampl entire circumference is shown. The R24C41. As the burst occurred outside of the TSP region, the the view is in the down "0" that is inside the tube corresponds with the 0° location (since e direction). This elevation was direction, azimuthal locations proceed in the counter-clockwis shallow corrosion (see Figure 5-4 chosen to show the cracks at the 180° location and the patch of and Figure 4-20). The '1' marker is located at about 180°.

intergranular, but are shallow.

Figure 7-9 shows the cracks at the 180° location. The cracks are is 4.4% TW.

These are only 2-4 grains deep. The deepest crack in this view 7.5 R24C41 04H e (6B2B) taken from the 04H TSP Figure 7-10 shows a view of a transverse cross-sectional sampl (refer to the Figure 5-5 sectioning ofR24 C41. The gap in the circumference is the SEM sample of the' 1' mark in the figure, and diagram). The left side of the burst opening is just to the right the "0" that is inside the tube corresponds with the oo location (since the view is in the down e direction).

direction, azimuthal locations proce ed in the counter-clockwis 4-23), there were several patches As the mid-plane of the visual observation map shows (Figure cracks at the 80° location of cracks around the mid-plane of the 04H TSP. There were small in the 315°-360° range (Markers (Marker '1 '),the 40° location (Marker '2'), and larger cracks

'3', '4' and '5').

l axial ODSCC cracks with a Figure 7-11 shows the 80° location of Marker '1 '. It shows severa shown is 16.4%TW.

patch of shallow (<2 grains deep) I GA. The maxim um crack depth axial ODSCC cracks, without Figure 7-12 shows the 40° location ofMa rker '2'. It shows three any IGA. The maximum crack depth shown is 23.2%TW.

l axial ODSCC cracks, Figure 7-13 shows the 350° location ofMa rker '3'. It shows severa TW.

witho ut any IGA. The maximum crack depth shown is 35.2%

l axial deep ODSCC cracks, Figure 7-14 shows the 335° location ofMa rker '4'. It shows severa TW.

without any IGA. The maximum crack depth shown is 40.8%

July 2014 Metallography of Cracks Revision 0 SG-CCOE-14-1

7-3 ODSCC cracks, Figure 7-15 shows the 315° location ofMar ker '5'. It shows several axial deep without any IGA. The maxim um crack depth shown is 45.4%TW.

depth in the burst Many of the cracks in the 315 °-3 60° region approached the maximum crack mounted sample fracture (48.6%TW). Consequently, another three levels were examined. The 20 mils further down the TSP was ground/polished and etched another 5 mils, 14 mils and level (Figure 7-16).

region. The 350° orientation had a maxim um depth of 46%TW at the 20 mil July 2014 Metallography of Cracks Revision 0 SG-CCOE-14-1

7-4 Table 7-1: Defect Metallography Samples Tube TSP Section Mount# View Sectioning Diagram Rl9C3 8 02H 3B2B M3136 Transverse - Down Figure 5-l R24C41 02H 3B2 M3139 Transverse - Down Figure 5-3 R24C41 03H 5B2 M3138 Transverse - Down Figure 5-4 R24C41 04H 6B2B M3137 Transverse - Down Figure 5-5 July 2014 Metallography of Cracks Revision 0 SG-CCOE-14-1

7-5 Figure 7-1: R19C38 02H- Overall View ofTransverse Section July 2014 Metallography of Cracks Revision 0 SG-CCOE-14-1

7-6 Figure 7-2: R19C38 02H Cracks at 200° Opening Ductile Figure 7-3: R19C38 02H Crack at 340° July 2014 Metallography of Cracks Revision 0 SG-CCOE-14-1

7-7 Figure 7-4: R24C41 02H- Overall View of Transverse Section July 2014 Metallography of Cracks Revision 0 SG-CCOE-14-1

7-8 Figure 7-5: R24C41 02H Cracks at 20° Figure 7-6: R24C41 02H Cracks at 160° July 2014 Metallography of Cracks Revision 0 SG-CCOE-14-1

7-9 Figure 7-7: R24C41 02H Cracks at 340° July 2014 Metallog raphy of Cracks Revision 0 SG-CCOE-14-1

7-10 Figure 7-8: R24C41 03H- Overall View of Transverse Section Figure 7-9: R24C41 03H Cracks at 180° July 2014 Metallography of Cracks Revision 0 SG-CCOE-14-1

7-11 Figure 7-10: R24C41 04H- Overall View ofTransverse Section July 2014 Metallography of Cracks Revision 0 SG-CCOE-14-1

7-12 Figure 7-11: R24C41 04H Cracks at 80° Figure 7-12: R24C41 04H Cracks at 40° July 2014 Metallography of Cracks Revisio n 0 SG-CCOE-14-1

7-13 Figure 7-13: R24C41 04H Cracks at 350° Figure 7-14: R24C41 04H Cracks at 335° July 2014 Metallography of Cracks Revision 0 SG-CCOE-14-1

7-14 Figure 7-15: R24C41 04H Cracks at 315° Figure 7-16: R24C41 04H Cracks at 350°, 20 mils Further Down the TSP from Figure 7-13 July 2014 Metallography of Cracks Revision 0 SG-CCOE-14-1

8-1

8.0 CONCLUSION

S Hot leg TSP regions ofBeav er Valley Unit 2 SG-C pulled tubes R19C38 and R24C41 were examined in the laboratory at WCS. The TSP regions were screened for leakage, were burst cracks.

tested, and were examined by SEM and metallography to assess the morphology of their Room temperature leak screening was conducted at pressures up to and including SLB pressure None of the tubes that were pulled for laboratory examination leaked.

the TSP Room temperature burst tests were conducted on all of the TSP regions provided. All of psi g.

regions had burst pressures far in excess of 3NOP. The lowest burst pressure was 9678 SEM and metallography examinations confirmed that corrosion in the TSP regions was Cellular predominantly axially orientated ODSCC with a few small and shallow patches ofiGA.

corrosion was not observed. There was no corrosion found outside of the TSP regions. The 1.a of observed degradation is in accordance with the morphology criteria provided in Section GL 95-05 (Reference 1). The observed degradation is consistent with the current GL 95-05 database (Reference 13).

n.

All four TSP regions that were pulled for laboratory examination had some degree of corrosio The two TSP regions that had confirmed bobbin coil indications (R19C38-02H and R24C41 04H) had the deepest cracking. The R19C38-02H TSP had a maximu m crack depth of the 49.9%TW. The R24C41-04H TSP had a maximu m crack depth of 48.6%T W located within burst fracture, but there was another region of multiple axial cracks that were nearly as deep (maximum measured depth of 46.0%TW).

and The two TSP regions that did not have confirmed bobbin coil indications (R24C41-02H depth of R24C41-03H) had shallower cracks. The R24C41-02H TSP had a maximum crack 14.2%TW. The R24C41-03H TSP had a maximu m crack depth of 4.4%TW.

July 2014 Conclusions Revision 0 SG-CCOE-14-1

9-1

9.0 REFERENCES

1. NRC Generic Letter 95-05, "Voltage-Based Repair Criteria for Westinghouse Steam Generator Tubes Affected by Outside Diameter Stress Corrosion Cracking," USNRC Office ofNuclea r Reactor Regulation, August 3, 1995.
2. "Beaver Valley Unit 2 End-of-Cycle 17 Analysis and Prediction for End-of.:.Cycle 18 Voltage-Based Repair Criteria 90-Day Report," Latest Revision, SG-SGMP-14-17.
3. "Beaver Valley Unit 2 Model51 M Steam Generator Secondary Side Tube Support Plate Elevations for Eddynet Confirmation," DLC-98-768 I NSD-CPM-98-142, August 25, 1998.
4. "Transmittal ofLTR-CCOE-14-54 'Pulled Tubes Receipt'," FENOC-14-41, June 3, 2014.
5. "Steam Generator Tube Sample Identification," Churchill Site Level3 Work Instruction CS-W-9.19, Revision 0, June 2014.
6. "Beaver Valley Power Station Unit 2 2R17 Refueling Outage Steam Generator Degradation Assessment," SG-SGMP-14-4, March 2014.
7. "Leak Screening of Steam Generator Tubing," Churchill Site Level 3 Work Instruction CS-W-14.32, Revision 0, June 2014.
8. "Steam Generator Tubing Burst Testing and Leak Rate Testing Guidelines," Revision 0.

EPRI, Palo Alto, CA: 2002. 1006783.

9. "Steam Generator Program Guidelines," NEI 97-06 Revision 3, March 2011.
10. "Steam Generator Management Program: Steam Generator Integrity Assessment Guidelines," Revision 3. EPRI, Palo Alto, CA: 2009. 1019038.
11. "Burst Testing of Steam Generator Tubing," Churchill Site Level 3 Work Instruction CS-W-14.31, Revision 0, June 2014.
12. "Steam Generator Information Report," LTR-SGDA-11-189, Revision 0, August 2011.
13. "Steam Generator Tubing Outside Diameter Stress Corrosion Cracking at Tube Support Plates Database for Alternate Repair Limits," Addendum 7 to NP-7480-L Database.

EPRI, Palo Alto, CA: 2008. 1018047.

July 2014 References Revision 0 SG-CCOE-14-1

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