2CAN021906, Steam Generator Tube Inspection Report

Steam Generator Tube Inspection Report

ML19059A440
Person / Time
Site:	Arkansas Nuclear
Issue date:	02/28/2019
From:	Arnold T Entergy Operations
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
2CAN021906
Download: ML19059A440 (20)

Text

Entergy Operations, Inc.

1448 S.R. 333 Russellville, AR 72802 Tel 479-858-7826 Timothy L. Arnold Manager, Regulatory Assurance Arkansas Nuclear One 2CAN021906 February 28, 2019 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001

Subject:

Steam Generator Tube Inspection Report Arkansas Nuclear One, Unit 2 Docket No. 50-368 Renewed Facility Operating License No. NPF-6

Dear Sir or Madam:

Entergy Operations, Inc. (Entergy) inspected the Arkansas Nuclear One, Unit 2 (ANO-2) Steam Generator (SG) tubes during the Fall 2018 refueling outage (2R26) in accordance with ANO-2 Technical Specification (TS) 6.5.9, "Steam Generator (SG) Program." ANO-2 TS 6.6.7, "Steam Generator Tube Inspection Report," requires that the results of inspections performed during the report period be submitted to the NRC within 180 days after the initial entry into Mode 4. The initial entry into Mode 4 post-2R26 occurred on November 13, 2018. The required inspection report is provided as an Enclosure to this letter.

The 2R26 inspection performed on both SGs involved an initial full-length bobbin coil examination of 100%.

This submittal completes the reporting requirements of the ANO-2 TSs for this inspection. This submittal contains no regulatory commitments.

2CAN021906 Page 2 of 2 Should you have any questions, please Contact Timothy L. Arnold, Manager, Regulatory Assurance at 479-858-7826.

Respectfully, ORIGINAL SIGNED BY TIMOTHY L. ARNOLD TLA/rwc

Enclosure:

Arkansas Nuclear One, Unit 2 Steam Generator 180 Day Inspection Report cc: Mr. Scott A. Morris Regional Administrator U. S. Nuclear Regulatory Commission Region IV 1600 East Lamar Boulevard Arlington, TX 76011-4511 NRC Senior Resident Inspector Arkansas Nuclear One P. O. Box 310 London, AR 72847 U. S. Nuclear Regulatory Commission Attn: Mr. Thomas Wengert MS O-08B1A One White Flint North 11555 Rockville Pike Rockville, MD 20852

Enclosure 2CAN021906 Arkansas Nuclear One, Unit 2 Steam Generator 180 Day Inspection Report (17 pages)

Enclosure to 2CAN021906 Page 1 of 17 ARKANSAS NUCLEAR ONE, UNIT 2 STEAM GENERATOR 180 DAY INSPECTION REPORT 1 INTRODUCTION Arkansas Nuclear One, Unit 2 (ANO-2) Technical Specification (TS) 6.6.7 states that a report shall be submitted within 180 days after the initial entry into HOT SHUTDOWN following completion of an inspection performed in accordance with TS 6.5.9, Steam Generator (SG)

Program. The report shall include:

a. The scope of inspections performed on each SG,

b. Degradation mechanisms found,

c. Nondestructive examination techniques utilized for each degradation mechanism,

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

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

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

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

The operating period for this report includes one refueling outage inspection, 2R26, which started on September 29, 2018, and was the fifth In Service Inspection (ISI) following SG replacement. This report details the results of that inspection.

2 DESIGN The ANO-2 Replacement Steam Generators (RSGs) are Westinghouse Model Delta 109 SGs with 10,637 thermally treated Alloy 690 U-tubes. The tubes have a nominal outside diameter of 0.688 inch and a nominal wall thickness of 0.040 inch. The tubes are hydraulically expanded through the tubesheet thickness, and are supported by eight, broached-hole tube support plates (TSPs). In the U-bend region, the tubes are supported by five sets of staggered Type 405 stainless steel anti-vibration bars (AVBs).

Enclosure to 2CAN021906 Page 2 of 17 3 REPORT REQUIREMENTS 3.1 The scope of inspections performed on each SG Table 3.1 lists the inspection scope of 2R26.

TABLE 3.1 SGA Number of Examination Type  % Scope Extent Tested Inspections Bobbin 11079 100% Full Length 1455 + 20 tubes for Array Hot Leg (HL) 13.31% various deposit map Array Cold Leg (CL) 1372 12.38% various Special Interest 32 - various Array/+Point SGB Number of Examination Type  % Scope Extent Tested Inspections Bobbin 11070 100% Full Length 1391 + 20 tubes for Array HL 12.75% various deposit map Array CL 1340 12.10% various Special Interest 30 - various Array/+Point

Enclosure to 2CAN021906 Page 3 of 17 3.2 Degradation mechanisms found The primary tube degradation mechanism identified was wear at the AVB supports, with a total of two hundred thirty-six indications. Additionally, forty-three wear indications were identified at the TSP. Eleven loose part wear indications were identified, all of which were historical from prior inspections.

The total number of wear indications in each generator is listed in Table 3.2.

TABLE 3.2 SG AVB Wear TSP Wear Loose Part Wear A 124 17 8 B 112 26 3

Enclosure to 2CAN021906 Page 4 of 17 3.3 Nondestructive examination techniques utilized for each degradation mechanism TABLE 3.3 Degradation Demonstrated / Extended Probe EPRI ETSS Detection Sizing Applicability Mechanism(s) Applicability Bobbin Probe Techniques 96041.1 (Rev. 5)

AVBs/None Yes CMOA @ AVB App. I Support Wear Bobbin AVBs, TSPs, and diagonal 96004.1 (Rev. 13) Yes CMOA @ TSP straps/None PLP wear (Part not present) Not Recommended.

Foreign Object Bobbin 27091.2 (Rev. 2) /PLP Wear (Part present) Yes Size with +Point TM or Wear and volumetric indications Array Wear TM

+Point 10908.4 (Rev. 1) Yes 17908.1 (Rev. 1) AVBs/Loose part wear with AVB Wear App. I CMOA @ AVB Array or without part present Yes 17908.4 (Rev. 1)

App. I TM

+Point 96910.1 (Rev. 11) Yes Broached TSPs/Loose part TSP Wear 11956.3 (Rev 2) wear with or without part CMOA @ TSP Array present Yes 11956.4 (Rev 2) 27901.1 (Rev. 1) Circ groove, Note 1 27902.1 (Rev. 2) Axial groove, Note 1 Detection of Foreign Tapered football, Material based on material 27903.1 (Rev. 1) and proximity of foreign Note 1 material to the tube based Tapered round hole, on EPRI reports 1020631 CMOA Freespan, 27904.1 (Rev. 2)

Foreign Object TM Note 1 and 1018561. expansion transitions and

+Point Wear at structures (Part not Flat wear, present) 27905.1 (Rev. 2)

Note 1 For sizing of PLP wear when part is present based Tapered wear, on EPRI Report 1020631 27906.1 (Rev. 1)

Note 1 on an as needed basis.

45° tapered wear, 27907.1 (Rev. 2)

Note 1

Enclosure to 2CAN021906 Page 5 of 17 TABLE 3.3 continued Demonstrated /

Degradation Probe EPRI ETSS Extended Detection Sizing Applicability Mechanism(s)

Applicability Wear Circ groove, 17906.3 (Rev. 0) - Circ.

Note 3 Axial groove, 17902.1 (Rev. 0) - Ax.

Note 3 Tapered football, CMOA Freespan, 17903.1 (Rev. 0) - Ax.

Foreign Object Note 3 expansion transitions and Array Yes Wear Tapered round hole, at structures (Part not 17904.1 (Rev. 0) - Ax. present)

Note 3 Flat wear, 17905.1 (Rev. 0) - Ax.

Note 3 Tapered wear, 17906.1 (Rev. 0) - Ax.

Note 3 Pitting TM

+Point 21998.1 (Rev. 4) Volumetric in freespan / Yes CMOA Pitting Array 24998.1 (Rev. 1) Sludge pile Yes No - Size with +Point' Diagnostic Techniques (Note 2)

Bobbin Various Various All Locations N/A Array Notes:

1. Demonstrated applicability for 2790x.1 series includes PLP wear (part not present) and extended applicability for 2790x.1 series includes PLP wear at TTS and TSP (part present).

2. For the purposes of this document, diagnostic techniques are actually EPRI Appendix H and/or I qualified techniques that fall outside of the site validation process. The specific applications where diagnostic techniques will be utilized have been evaluated and determined to be consistent with industry practice. In addition, the data analysis instructions provided in the site Guidelines/ETSS provide the requisite assurance that unexpected degradation mechanisms will be detected and reported.

3. Demonstrated applicability for 1790x.1 series includes PLP wear (part not present) and extended applicability for 1790x.1 series includes PLP wear at TTS and TSP (part present)

Enclosure to 2CAN021906 Page 6 of 17 3.4 Location, orientation (if linear), and measured sizes (if available) of service induced indications Service induced indications included wear at the AVBs, TSPs, and due to loose parts. Due to the large number of indications, these are included in Attachment 1 and Attachment 2.

3.5 Number of tubes plugged during the inspection outage for each degradation mechanism Nine tubes were plugged in SG A and three tubes were plugged in SG B during the 2R26 inspection. Details are listed in Table 3.5 below.

TABLE 3.5 SG ROW COL Indication A 132 73 PTP - 28% @A15 A 132 75 PTP - 33% @A11 A 133 82 PTP - 34% @A11 A 138 83 PTP - 39% @ A11 A 124 95 PTP - 34% @A15 A 142 115 PTP - PLP @TSH A 141 116 PTP - PLP @TSH A 143 116 PTP - PLP @TSH A 142 117 PTP - PLP @TSH B 142 83 PTP - 36% @A11 B 142 91 TBP - 42% @A15 B 6 99 PTP - PLP @TSC

Enclosure to 2CAN021906 Page 7 of 17 3.6 The number and percentage of tubes plugged to date, and the effective plugging percentage in each SG Tube plugging during 2R26 and prior outages is detailed below in Table 3.6.

TABLE 3.6 SG A SG B Year Outage Installed Cumulative  % Plug Installed Cumulative  % Plug 2000 Fabrication 0 0 0.00 1 1 0.01 2000 Baseline 0 0 0.00 0 1 0.01 2002 2R15 0 0 0.00 0 1 0.01 2005 2R17 4 4 0.04 8 9 0.08 2009 2R20 1 5 0.05 4 13 0.12 2014 2R23 5 10 0.09 5 18 0.17 2018 2R26 9 19 0.18 3 21 0.20 3.7 The results of condition monitoring, including the results of tube pulls and in-situ testing All of the AVB, TSP, and foreign object wear indications were less than the condition monitoring limits and therefore met condition monitoring analytically. Additionally, the findings of the 2R26 SG examination were bounded by the behavior projected in the 2R23 operational assessment.

There were no tube pulls or in-situ testing performed during 2R26.

Enclosure to 2CAN021906 Page 8 of 17 Attachment 1 Wear Indications - SG A FLAW ROW COL TWD LOCATION ELEVATION COMMENT 1 1 22 9 03C 0.43 TSP 2 2 1 17 02C -0.07 TSP 3 3 28 9 A01 -0.12 AVB 4 4 181 19 03C 0 TSP 5 5 2 12 02C 0 TSP 6 5 2 16 03C -0.07 TSP 7 43 148 17 A06 2.71 AVB 8 52 175 10 A06 -0.42 AVB 9 52 123 7 A07 0.62 AVB 10 52 39 9 A07 0.32 AVB 11 52 135 9 A07 0.47 AVB 12 52 143 12 A07 0.44 AVB 13 53 34 7 A07 0 AVB 14 57 174 9 A17 -0.08 AVB 15 59 60 12 A07 -0.19 AVB 16 60 171 12 A07 0.09 AVB 17 60 171 8 A13 -0.23 AVB 18 60 173 15 A16 -0.25 AVB 19 62 13 15 A05 0.2 AVB 20 63 46 10 A14 -0.11 AVB 21 63 10 11 A15 -0.18 AVB 22 64 61 7 A08 0.34 AVB 23 64 67 7 A13 -0.01 AVB 24 65 144 8 A13 -1.63 AVB 25 66 13 10 A05 0.28 AVB 26 70 61 7 A13 -0.21 AVB 27 74 15 8 A05 -0.08 AVB 28 74 167 8 A07 0.14 AVB 29 74 15 16 A18 0.11 AVB 30 77 68 8 A13 0.08 AVB

Enclosure to 2CAN021906 Page 9 of 17 Attachment 1 Wear Indications - SG A FLAW ROW COL TWD LOCATION ELEVATION COMMENT 31 79 162 9 A15 0.28 AVB 32 80 73 7 A09 -0.23 AVB 33 80 117 8 A09 0.02 AVB 34 80 125 8 A09 0 AVB 35 80 115 9 A09 0.87 AVB 36 80 133 9 A09 0.37 AVB 37 80 121 14 A09 0.18 AVB 38 80 87 17 A09 0.98 AVB 39 80 89 8 A12 -0.81 AVB 40 81 62 8 A09 0.25 AVB 41 81 94 9 A09 0.35 AVB 42 83 18 14 A15 -0.2 AVB 43 83 18 7 A17 -0.02 AVB 44 84 111 7 A09 0 AVB 45 84 165 13 A15 0.15 AVB 46 87 108 18 A09 0.22 AVB 47 88 93 9 A09 0.26 AVB 48 89 110 7 A09 0.21 AVB 49 89 96 9 A09 0.03 AVB 50 89 162 13 A14 0.12 AVB 51 96 101 19 A10 0.35 AVB 52 99 82 9 A09 0.04 AVB 53 99 82 8 A16 0 AVB 54 102 91 11 A09 -0.02 AVB 55 103 94 12 A09 0.05 AVB 56 104 81 13 A17 -0.03 AVB 57 105 50 15 08C 0.43 TSP 58 105 152 10 A12 0.11 AVB 59 105 90 12 A14 0.05 AVB 60 106 27 12 03C 0.46 TSP

Enclosure to 2CAN021906 Page 10 of 17 Attachment 1 Wear Indications - SG A FLAW ROW COL TWD LOCATION ELEVATION COMMENT 61 106 107 9 A12 0.18 AVB 62 109 90 17 A08 -0.01 AVB 63 109 90 15 A11 0.23 AVB 64 109 90 11 A16 -0.05 AVB 65 109 90 11 A20 -0.06 AVB 66 112 91 9 A07 0.02 AVB 67 112 91 9 A13 -0.06 AVB 68 114 81 7 A12 -0.08 AVB 69 117 100 13 A09 0.12 AVB 70 119 100 9 A08 -0.02 AVB 71 121 86 24 A09 0.02 AVB 72 121 138 19 A13 0 AVB 73 121 138 11 A16 0.05 AVB 74 123 46 9 A07 0.32 AVB 75 123 46 10 A13 -0.27 AVB 76 123 46 11 A15 -0.38 AVB 77 123 44 9 A17 -0.24 AVB 78 124 83 8 A07 0.6 AVB 79 124 91 10 A11 0.02 AVB 80 124 45 22 A13 0.2 AVB 81 124 47 22 A13 0.25 AVB 82 124 95 26 A13 0.67 AVB 83 124 47 16 A15 0.16 AVB 84 124 95 34 A15 0 AVB 85 124 95 11 A17 0 AVB 86 125 48 24 A13 -0.38 AVB 87 126 113 8 A09 0.08 AVB 88 127 78 9 A09 0 AVB 89 127 78 10 A15 0.45 AVB 90 128 75 18 A11 0.57 AVB

Enclosure to 2CAN021906 Page 11 of 17 Attachment 1 Wear Indications - SG A FLAW ROW COL TWD LOCATION ELEVATION COMMENT 91 128 75 17 A15 0.33 AVB 92 132 123 11 07C 0.35 TSP 93 132 127 13 A07 0.07 AVB 94 132 73 11 A09 -0.71 AVB 95 132 75 33 A11 0.46 AVB 96 132 73 28 A15 0.23 AVB 97 133 48 12 08H -0.44 TSP 98 133 82 8 A09 -0.84 AVB 99 133 82 34 A11 0.38 AVB 100 133 68 15 A13 0.34 AVB 101 133 96 21 A13 0.47 AVB 102 133 68 24 A15 0.37 AVB 103 134 51 13 06H -0.61 TSP 104 134 87 12 A11 -0.57 AVB 105 134 87 21 A15 0.18 AVB 106 134 87 13 A17 0.12 AVB 107 135 102 18 A07 0.59 AVB 108 135 86 8 A09 -0.67 AVB 109 135 98 13 A09 0.52 AVB 110 135 122 13 A09 0 AVB 111 135 102 26 A09 0.98 AVB 112 135 88 13 A13 0.29 AVB 113 135 102 17 A13 0.49 AVB 114 135 102 23 A15 -0.33 AVB 115 135 102 16 A17 -0.2 AVB 116 136 109 11 A13 0.33 AVB 117 137 74 23 A11 0.39 AVB 118 138 125 12 08H -0.54 TSP 119 138 55 17 08H -0.42 TSP 120 138 119 12 A05 0.32 AVB

Enclosure to 2CAN021906 Page 12 of 17 Attachment 1 Wear Indications - SG A FLAW ROW COL TWD LOCATION ELEVATION COMMENT 121 138 119 15 A09 -0.28 AVB 122 138 119 14 A11 0.44 AVB 123 138 83 39 A11 -0.49 AVB 124 138 123 15 A13 0.02 AVB 125 138 83 17 A13 -0.32 AVB 126 138 119 12 A15 -0.13 AVB 127 138 97 14 A15 0.34 AVB 128 138 119 10 A19 0.12 AVB 129 139 56 9 A07 0.23 AVB 130 139 114 10 A09 0.05 AVB 131 139 88 14 A09 -0.56 AVB 132 139 88 11 A11 -0.68 AVB 133 139 88 23 A13 -0.44 AVB 134 139 88 18 A15 -0.35 AVB 135 139 88 9 A19 0.06 AVB 136 141 118 10 A09 -0.25 AVB 137 142 61 9 06H -0.7 TSP 138 142 61 15 08H -0.41 TSP 139 142 111 26 TSH 27.22 PLP 140 142 119 12 TSH 30.92 PLP 141 142 119 6 TSH 30.26 PLP 142 143 112 11 04H 18.76 PLP 143 143 114 19 08C 0.27 TSP 144 144 119 13 TSH 28.48 PLP 145 146 113 13 TSH 26.83 PLP 146 146 115 11 TSH 26.61 PLP 147 146 115 7 TSH 25.88 PLP 148 148 71 12 03H -0.52 TSP 149 150 105 13 06H -0.66 TSP

Enclosure to 2CAN021906 Page 13 of 17 Attachment 2 Wear Indications - SG B FLAW ROW COL TWD LOCATION ELEVATION COMMENT 1 1 174 10 05C -0.48 TSP 2 3 84 9 05C -0.5 TSP 3 4 81 17 05C 0 TSP 4 8 99 14 05C -0.52 TSP 5 40 177 14 A16 -0.07 AVB 6 42 177 13 A16 -0.03 AVB 7 44 177 14 A16 0 AVB 8 50 41 11 A14 -0.48 AVB 9 52 109 6 A07 0 AVB 10 53 142 7 A07 0.17 AVB 11 55 174 9 A15 -0.34 AVB 12 59 170 7 A07 -0.27 AVB 13 61 164 13 A14 -0.03 AVB 14 64 103 6 A08 0 AVB 15 64 47 8 A08 0.71 AVB 16 69 170 10 A07 0 AVB 17 70 169 7 A05 0 AVB 18 70 169 13 A07 0 AVB 19 75 14 13 03C -0.45 TSP 20 77 168 12 05C 0.41 TSP 21 77 168 7 06C 0.41 TSP 22 79 118 9 A09 -0.27 AVB 23 80 79 10 A09 0.24 AVB 24 80 95 16 A09 0.33 AVB 25 81 82 7 A14 0.05 AVB 26 82 69 7 A08 -0.17 AVB 27 83 128 7 A09 0.19 AVB 28 86 91 6 A17 -0.49 AVB 29 90 163 8 05C -0.6 TSP 30 92 161 8 04C -0.45 TSP

Enclosure to 2CAN021906 Page 14 of 17 Attachment 2 Wear Indications - SG B FLAW ROW COL TWD LOCATION ELEVATION COMMENT 31 92 161 10 05C 0.39 TSP 32 94 161 9 04C 0.45 TSP 33 96 105 6 A10 0 AVB 34 97 158 11 04C 0.45 TSP 35 100 91 7 A07 0 AVB 36 100 25 23 TSC 12.67 PLP 37 105 86 11 A09 -0.37 AVB 38 109 102 7 A05 0.02 AVB 39 109 102 13 A13 0 AVB 40 109 102 26 A18 0.04 AVB 41 109 102 11 A19 0 AVB 42 110 133 8 A16 -0.09 AVB 43 111 108 10 A09 -0.12 AVB 44 111 92 16 A11 0.04 AVB 45 111 102 8 A13 0 AVB 46 111 96 23 A15 0 AVB 47 111 96 17 A16 0 AVB 48 111 96 10 A17 0 AVB 49 112 105 7 A07 0.02 AVB 50 112 149 10 A12 -0.19 AVB 51 112 149 7 A14 -0.21 AVB 52 112 149 17 A18 0.04 AVB 53 113 90 11 A07 0.21 AVB 54 113 92 8 A09 0 AVB 55 113 94 26 A13 0 AVB 56 113 92 15 A14 0 AVB 57 113 92 10 A17 0 AVB 58 115 104 13 A12 0.02 AVB 59 115 92 11 A13 0 AVB 60 115 104 11 A15 0.01 AVB

Enclosure to 2CAN021906 Page 15 of 17 Attachment 2 Wear Indications - SG B FLAW ROW COL TWD LOCATION ELEVATION COMMENT 61 116 99 7 A06 0.02 AVB 62 116 99 20 A09 0.02 AVB 63 116 99 15 A12 -0.03 AVB 64 116 57 16 A16 -0.01 AVB 65 116 57 9 A18 0 AVB 66 117 70 8 A10 0 AVB 67 118 97 9 A12 0 AVB 68 120 63 12 A14 -0.01 AVB 69 120 63 11 A16 0 AVB 70 120 63 8 A18 0 AVB 71 122 91 19 A13 0.02 AVB 72 123 40 11 04C 0.43 TSP 73 124 99 7 A09 0.72 AVB 74 124 83 8 A09 0.07 AVB 75 125 46 9 A11 0.2 AVB 76 125 140 9 A11 -0.49 AVB 77 125 56 9 A13 0.43 AVB 78 125 46 13 A13 0.36 AVB 79 125 96 13 A13 0 AVB 80 125 82 14 A13 0.73 AVB 81 125 62 15 A15 0.29 AVB 82 125 96 20 A15 0 AVB 83 125 62 10 A19 0.11 AVB 84 126 85 12 A11 -0.93 AVB 85 128 93 13 A11 0 AVB 86 128 61 20 A11 0.61 AVB 87 128 93 9 A13 0 AVB 88 128 61 10 A15 -0.22 AVB 89 130 133 10 A17 -0.17 AVB 90 131 122 9 08C 0.34 TSP

Enclosure to 2CAN021906 Page 16 of 17 Attachment 2 Wear Indications - SG B FLAW ROW COL TWD LOCATION ELEVATION COMMENT 91 131 54 8 A13 -0.31 AVB 92 132 83 7 A07 -0.41 AVB 93 132 57 9 A09 -0.25 AVB 94 132 57 23 A11 0.52 AVB 95 132 53 11 A13 0.02 AVB 96 132 57 15 A13 -0.4 AVB 97 133 94 15 A13 0.38 AVB 98 136 53 14 05C 0.47 TSP 99 136 115 14 A09 -0.32 AVB 100 136 115 12 A11 0.56 AVB 101 136 115 22 A13 0.38 AVB 102 136 115 23 A15 -0.18 AVB 103 137 92 10 A09 0 AVB 104 137 92 10 A11 0.58 AVB 105 137 92 17 A15 0.36 AVB 106 138 91 12 A11 0.05 AVB 107 138 105 24 A11 0.5 AVB 108 138 119 9 TSH 1.13 PLP 109 138 119 8 TSH 0.25 PLP 110 139 126 15 08H -0.64 TSP 111 140 123 13 06H -0.43 TSP 112 140 121 7 A09 -0.32 AVB 113 140 77 24 A09 -0.45 AVB 114 140 71 9 A11 0 AVB 115 140 99 12 A11 0.54 AVB 116 140 77 13 A11 -0.47 AVB 117 140 77 19 A11 0.51 AVB 118 140 77 20 A13 -0.29 AVB 119 140 71 8 A15 -0.21 AVB 120 140 99 9 A15 0.05 AVB

Enclosure to 2CAN021906 Page 17 of 17 Attachment 2 Wear Indications - SG B FLAW ROW COL TWD LOCATION ELEVATION COMMENT 121 140 99 22 A17 0.15 AVB 122 141 60 15 04H 0.39 TSP 123 141 102 10 A09 0.33 AVB 124 142 83 12 A09 0.34 AVB 125 142 91 25 A11 0.02 AVB 126 142 83 36 A11 -0.48 AVB 127 142 83 16 A13 -0.36 AVB 128 142 91 34 A13 0.04 AVB 129 142 91 42 A15 0.07 AVB 130 142 91 20 A17 0.04 AVB 131 142 91 15 A19 0.02 AVB 132 143 62 18 05C -0.54 TSP 133 143 94 10 A09 0.36 AVB 134 143 90 11 A11 -0.34 AVB 135 144 67 9 05C 0.45 TSP 136 144 67 12 05C -0.58 TSP 137 144 63 15 05C -0.54 TSP 138 146 113 11 05H -0.58 TSP 139 148 109 8 04H 0.52 TSP 140 148 109 11 04H -0.56 TSP 141 149 86 14 06H 0.37 TSP