BYRON 2023-0029, Response to Request for Additional Information Regarding Steam Generator Tube Inspection Reports to Reflect TSTF-577 Reporting Requirements

Response to Request for Additional Information Regarding Steam Generator Tube Inspection Reports to Reflect TSTF-577 Reporting Requirements

ML23152A061
Person / Time
Site:	Byron
Issue date:	06/01/2023
From:	Welt H Constellation Energy Generation
To:	Office of Nuclear Reactor Regulation, Document Control Desk
References
BYRON 2023-0029
Download: ML23152A061 (1)

Text

Constellation Energy Generation, LLC (CEG)

Byron Station Constellation,. 4450 N. German Church Road Byron, IL 61010-9794 www.constellationenergy.com June 1, 2023 LTR: BYRON 2023-0029 File: 1D.101 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555-0001 Byron Station, Units 1 and 2 Renewed Facility Operating License Nos. NPF-37 and NPF-66 NRC Docket Nos. STN 50-454 and STN 50-455

Subject:

Response to Request for Additional Information Regarding Byron Station, Units 1 and 2, Steam Generator Tube Inspection Reports to Reflect TSTF-577 Reporting Requirements

References:

1. Letter from K. Lueshen (Constellation Energy Generation, LLC) to U.S. Nuclear Regulatory Commission, "Application to Revise Technical Specifications to Adopt TSTF-577, 'Revised Frequencies for Steam Generator Tube Inspections'," dated August 10, 2022 (ADAMS Accession No. ML22222A068)

2. Letter from J. Wiebe (U.S. Nuclear Regulatory Commission) to D. Rhoades (Constellation Energy Generation, LLC), "Byron Station, Unit Nos. 1 and 2 -

Issuance of Amendments 231 and 231 Re: Adoption of TSTF-577, 'Revised Frequencies for Steam Generator Tube Inspections,' Revision 1 (EPID L-2022-LLA-0115) ," dated December 28, 2022 (ADAMS Accession No. ML22305A699)

3. Letter from H. Welt (Constellation Energy Generation, LLC) to U.S. Nuclear Regulatory Commission, "Byron Station, Unit 1 and Unit 2, Steam Generator Tube Inspection Report to Reflect TSTF-577 Reporting Requirements," dated April 6, 2023 (ADAMS Accession No. ML23096A144)

4. Email from J. Wiebe (U.S. Nuclear Regulatory Commission) to Z. Cox (Constellation Energy Generation, LLC), "Byron, Unit 2, Steam Generator Report- Request for Additional Information," dated May 10, 2023

U.S. Nuclear Regulatory Commission LTR: BYRON 2023-0029 Page 2 June 1, 2023 In Reference 1, Constellation Energy Generation, LLC (CEG) requested amendments to Renewed Facility Operating License Nos. NPF-37 and NPF-66 for the Byron Station (Byron),

Units 1 and 2, to adopt Technical Specifications Task Force (TSTF)-577, "Revised Frequencies for Steam Generator Tube Inspections." Reference 1 was approved by the Nuclear Regulatory Commission (NRC) for Byron with Reference 2. As noted in Reference 1, "CEG will submit SG Tube Inspection Reports meeting the revised TS 5.6.9 requirements within 30 days after implementation of the license amendment at Byron." This was completed with the report dated April 6, 2023 (Reference 3), which included revised Byron Unit 1 and Unit 2 SG Tube Inspection Reports that met the revised Byron TS 5.6.9 reporting requirements.

In Reference 4, the NRC requested additional information that is need needed to complete its review of the Byron Unit 1 and Unit 2 SG Tube Inspection Reports submitted with Reference 3.

As discussed with the NRR Project Manager on May 10, 2023, the information is requested within 30 days of the date of issuance of Reference 4 (i.e., by June 9, 2023). The Attachment and Enclosures provide the additional information.

There are no regulatory commitments included in this letter. Please address any questions regarding this letter to zoe.cox@constellation.com.

Respectfully, Harris Welt Site Vice President Byron Station

Attachment:

Response to Request for Additional Information

Enclosures:

1. Byron Station, Unit 1 Updated Steam Generator Tube Inspection Report

2. Byron Station, Unit 2 Updated Steam Generator Tube Inspection Report cc: NRC Project Manager - NRR - Braidwood/ Byron NRC Regional Administrator, Region Ill NRC Senior Resident Inspector, Byron Station Illinois Emergency Management Agency - Division of Nuclear Safety

ATTACHMENT Response to Request for Additional Information NRC REQUEST FOR ADDITIONAL INFORMATION By letters dated October 27, 2022, and April 6, 2023 (Agencywide Documents Access and Management System Accession Nos. ML22300A049 and ML23096A144, respectively),

Constellation Energy Generation, LLC (the licensee), submitted information summarizing the results of the spring 2022 steam generator (SG) inspections performed at Byron Nuclear Power Station, Unit 2 (Byron Unit 2). The inspections were performed during refueling outage 23.

All pressurized water reactors have Technical Specifications (TS) according to 10 CFR 50.36 that include a SG Program with specific criteria for the structural and leakage integrity, repair, and inspection of SG tubes. At Byron Unit 2, the requirements for performing SG tube inspections and repair are in TS Section 5.5.9, while the requirements for reporting the SG tube inspections and repair are in TS Section 5.6.9, "Steam Generator (SG) Tube Inspection Report."

Reporting requirement 5.6.9c.1 of the SG Tube Inspection Report states that the report shall include for each degradation mechanism found, the location, orientation (if linear), measured size (if available), and voltage response for each indication. For tube wear at support structures less than 20 percent through-wall, only the total number of indications needs to be reported.

Table 4 of the April 6, 2023, letter indicates that there were 5 tubes in SG 2A with anti-vibration bar (AVB) wear indications greater than or equal to 40 percent through-wall. When Attachment A to the April 6, 2023, letter was reviewed for details related to the sizing of these indications, only 3 of the tubes were found to be listed. A comparison was made to the 2017 SG Tube Inspection Report, and it was noted that many tubes with AVB wear indications greater than 20 percent through-wall in SG A and SG B that were reported in 2017 were not reported in 2023.

To complete its review of the reports referenced above, the U.S. Nuclear Regulatory Commission (NRC) staff requests the following additional information:

1. Please resubmit the April 6, 2023, Steam Generator Tube Inspection Report with all indications, in accordance with reporting requirement 5.6.9.c.1.

2. The quality of the scanning is very poor in some key areas of these reports. Mainly this is in Enclosure 1 of the April 6, 2023, letter (Byron Unit 1 report), Figures 3, 4a, and 4b, as well as the table of eddy current indications in Attachment A Especially on the figures, some of the information was lost in the scan, including degradation indications (e.g.,

Figure 4a does not show the indications, and they are barely visible in Figures 3 and 4b).

CEG Response to RAI The requested information is provided in Enclosures 1 and 2. These Enclosures address the above comments regarding quality issues. provides a revised Byron Unit 1 SG Tube Inspection Report in accordance with the revised Byron Unit 1 TS 5.6.9 reporting requirements. Each Byron Unit 1 TS 5.6.9 reporting requirement is listed along with the associated information based on the inspection performed during the Byron Unit 1 Cycle 23 spring 2020 refueling outage (B 1R23), which was the most recent inspection of the Byron Unit 1 replacement SGs (Reference 1).

1 of 2

ATTACHMENT Response to Request for Additional Information provides a revised Byron Unit 2 SG Tube Inspection Report in accordance with the revised Byron Unit 2 TS 5.6.9 reporting requirements. Each Byron Unit 2 TS 5.6.9 reporting requirement is listed along with the associated information based on the inspection performed during the Byron Unit 2 Cycle 23 spring 2022 refueling outage (B2R23), which was the most recent inspection of the Byron Unit 2 SGs (Reference 2).

REFERENCES

1. Exelon letter to U.S. Nuclear Regulatory Commission "Byron Station, Unit 1 Steam Generator Tube Inspection Report for Refueling Outage 23," dated September 10, 2020 (ADAMS Accession No. ML20253A042)

2. Constellation letter to U.S. Nuclear Regulatory Commission "Byron Station, Unit 2 Steam Generator Tube Inspection Report for Refueling Outage 23," dated October 27, 2022 (ADAMS Accession No. ML22300A049) 2 of 2

Enclosur e 1 Byron Station, Unit 1 Updated Steam Generat or Tube Inspectio n Report

Enclosur e 1 Byron Station, Unit 1 Updated Steam Generator Tube Inspection Report Introduction In Reference 1, Constellation Energy Generation (CEG) submitted a request for an amendment to Renewed Facility Operating License No. NPF-37 for the Byron Station (Byron), Unit 1 to adopt Technical Specifications Task Force (TSTF)-577, "Revised Frequencies for Steam Generator Tube Inspections." Reference 1 was approved by the Nuclear Regulatory Commission (NRC) in Reference 2. As noted in Reference 1, "CEG will submit SG Tube Inspection Reports meeting the revised TS 5.6.9 requirements within 30 days after implementatio n of the license amendment at Byron." Based on NRC approval (Reference 2) TSTF-577 was implemented at Byron Station on March 8, 2023, and the revised Byron Unit 1 SG Tube Inspection Report was submitted on April 6, 2023 (Reference 5).

Byron Unit 1 Technical Specification (TS) 5.6.9, "Steam Generator Tube Inspection Report," states "A report shall be submitted within 180 days after the initial entry into MODE 4 following completion of an inspection performed in accordance with the Specification 5.5.9, 'Steam Generator (SG) Program'." This enclosure provides the revised 180-day report with the revised Byron Unit 1 TS 5.6.9 reporting requirements in accordance with References 1 and 2. Each Byron Unit 1 TS 5.6.9 reporting requirement is listed below along with the associated information based on the inspection performed during the Byron Unit 1 Cycle 23 March 2020 refueling outage (B1 R23), which was the last inspection of the Byron Unit 1 replacement steam generators (Reference 3). This report follows the template provided in Appendix G to the Electric Power Research Institute (EPRI) Steam Generator Management Program: Steam Generator Integrity Assessment Guidelines, Revision 5 (Reference 4), which provides additional information beyond the Byron Unit 1 TS 5.6.9 reporting requirements.

1. Design and operating parameters The original SGs at Byron Unit 1 were replaced in 1998 with four Babcock & Wilcox replacement Steam Generators (SGs), which have thermally treated Alloy 690 tubing. The SGs had operated for three fuel cycles since the previous inspection at B1 R20. Table 1 provides the Byron Unit 1 SG design and operating parameter information.

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Enclosure 1 Table 1: Byron Unit 1 - Steam Generator Design and Operating Parameters SG Model / Tube Material / Babcock & Wilcox (Canada) Replacements/ Alloy Number of SGs per Unit 690TT / 4 Number of tubes per SG / 6,633 / 0.6875 in./ 0.040 in Nominal Tube Diameter/ Tube Thickness Support Plate Style / Material Lattice Tube Support Grids and Fan Bars/

stainless steel Last Inspection Date March 2020 Effective full power months 51.144 EFPM [4.262 effective full power years (EFPM) Since Last Inspection (EFPY)] (from B1 R20 to B1 R23)

Total Cumulative SG EFPY 20.8 EFPY (as of B1 R23)

Mode 4 Initial Entry 03/24/2020 from B1 R23 Observed Primary-to-Secon dary No observed leakage Leak Rate Nominal Thot at Full Power 616°F Operation Loose Parts Strainer Each main feedwater pump has small diameter holes in an inlet strainer to prevent the introduction of foreign material into the piping leading to the SGs.

Degradation Mechanism Tubes located on the periphery of the tube bundle are Sub-Population in the highest cross-flow region and were considered in the B1 R23 Degradation Assessment to be more susceptible to foreign object wear.

SG program guideline deviations None since last Inspection SG Schematic See Figure 1 E1 - 2 of 24

Enclosure 1 Figure 1 F06 FOS F09 HO FOl 09( 09H 08( 08H 07( 07H 06C 06H osc OSH 04C 04H 03{. 03H 02.C OZH 01{. 01H TSC TSH TEC TEH Tube Support Arrangement for Byron Unit 1 B&W Replacement SGs Notes:

TEC - Tube End Cold Leg TEH - Tube End Hot Leg TSC - Top-of-Tubesheet Cold Leg TSH - Top-of-Tubesheet Hot Leg 01 C - 09C - Lattice Grid Tube Supports on Cold Leg side 01 H - 09H - Lattice Grid Tube Supports on Hot Leg side F01 - F1 0 - U-Bend Fan Bar Tube Supports E1 - 3 of 24

Enclosure 1

2. The scope of the inspections performed on each SG (TS 5.6.9.a) and if applicable, a discussion of the reason for scope expansion The following inspections were performed during B 1R23 to ensure that 100% of the tubes were inspected during the period as required by TS 5.5.9.d.2 Primary Side Eddy Current Scope:

• 100% full-length bobbin coil eddy current examination of all in-service tubes in all four SGs.

• All Hot leg Dent & Dings >2.0 volts, Plus-Point probe in all four SGs.

• 53% peripheral array (X-Probe) examination on the Hot Leg for potential foreign objects and associated wear (peripheral locations are where crossflow velocities are the highest)

• 47% of peripheral array (X-Probe) examination Cold Leg for potential foreign objects and associated wear.

There was no scope expansion required or performed during the 81 R23 eddy current inspections.

In addition to the eddy current inspections, visual inspections were also performed on both the primary and secondary sides. Primary side visual inspections included the channel head bowl cladding and the divider plate. Secondary side visual inspections were performed at the top of the tubesheet for the detection of foreign objects, assessment of hard deposit buildup in the tube bundle interior kidney region, and for determining the effectiveness of the tubesheet cleaning performed in the four SGs.

3. The nondestructive examination techniques utilized for tubes with increased degradation susceptibility (TS 5.6.9.b)

Tubes located on the periphery of the tube bundle are in the highest cross-flow region and were considered in the Degradation Assessment to be more susceptible to foreign object wear, especially near the tubesheet where most foreign objects are located. As a compensatory measure, tubes in this region were tested with an array (X-probe) which has increased sensitivity for detection of foreign objects and foreign object wear close to the tubesheet. This scope encompassed 53% of the hot leg tubes and 4 7% of the cold leg tubes from the top-of-tubesheet to the 1st tube support (01 C/01 H).

4. The nondestructive examination technique utilized for each degradation mechanism found (TS 5.6.9.c.1)

Steam Generator eddy current examination techniques used (see Table 2 below) were qualified in accordance with Appendix Hor Appendix I of the EPRI PWR SG Examination Guidelines Revision 8. Each examination technique was evaluated to be applicable to the tubing and the degradation mechanisms found in the Byron Station Unit 1 SGs during 81R23.

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Enclosure 1 Table 2: NOE Techniques for Each Existing Degradation Mechanism Found During B1R23 Degradation EPRI Location Orientation Probe EPRI ETSS ETSS Mechanism Rev Fan Bar (U-bend) Wear Vol Bobbin 96004.3 (D&S) 13 Lattice Grid Wear Vol Bobbin 96004.3 (D&S) 13 (Horz. Support)

Bobbin 27091.2 (D) 2 Foreign Object at Array 1790X.1 (D) 0 top of tubesheet Wear Vol

+Point 21998.1 (S) 4 or lattice grid

+Point 27901.1 (S) 1 (D) = Detection (S) = Sizing

5. The location, orientation (if linear), measured size (if available), and voltage response for each indication. For tube wear at support structures less than 20 percent through-wall, only the total number of indications needs to be reported (TS 5.6.9.c.2)

Volumetric wear at support structures was the primary degradation mechanism detected during the 81 R23 inspection. The wear indications detected were located at either fan bar U-bend or horizontal lattice grid tube support structures. Table 3 provides the number of indications reported during the 81 R23 inspection.

Table 3: Number of Indications Detected for Each Degradation Mechanism in 81 R23 Degradation 1A 18 1C 1DSG Total Mechanism Indications Indications Indications Indications Fan Bar (U-bend 25 104 31 59 219 support) wear Lattice grid 6 3 1 3 13 Support Wear Foreign Object 0 5 1 0 6 Wear A detailed listing of all the Fan Bar wear indications reported during the 81 R23 inspection including the measured voltages and depths from the bobbin coil is provided in Attachment A (same data as submitted under Reference 3).

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Enclosure 1 Table 4 provides a listing of all the lattice grid wear indications reported during the 81 R23 inspection including the measured depths from the bobbin coil.

Table 4: 81 R23 Lattice Grid Wear Indications Depth Voltage SG Row Col Location (3/4TW)

(Bobbin SG1A 46 93 02C +1.21 4 0.28 SG1A 62 103 07H +1.25 7 0.33 SG1A 69 94 07H +1.38 6 0.26 SG1A 82 103 07H -0.68 6 0.49 SG1A 84 93 07H +1.34 6 0.30 SG1A 94 57 07H +0.99 11 0.59 SG 18 11 32 05H -1.46 7 0.30 SG 18 43 72 02H -1.61 5 0.26 SG 18 118 73 07H +1.63 11 0.68 SG 1C 21 142 07H -1.31 6 0.34 SG 10 8 1 06C -1.64 4 0.16 SG1D 51 8 08C -1 .48 8 0.29 SG1D 117 78 07H +0.58 10 0.42 Table 5 provides a listing of all the foreign object wear indications reported during the 81 R23 inspection including the measured voltages and depths from the plus-point probe.

Indications of tube wear at support structures are provided regardless of percent through-wall depth and the voltages provided correspond to the bobbin coil.

Table 5: 81 R23 Foreign Object Wear Indications

+Point Axial Circum-

+Point SG Row Col Location Depth Extent ferential Voltage (3/4TW) (Inches) Extent (Inches)

SG18 1 82 TSH+0.15 0.31 30%TW 0.2 0.41 SG1B 2 81 TSH +0.17 0.74 51%TW* 0.3 0.49 SG1B 3 82 TSH +0.26 0.24 25%TW 0.18 0.37 SG 18 4 81 TSH +0.20 0.20 22%TW 0.18 0.35 SG1B 5 82 TSH +0.09 0.17 20%TW 0.15 0.35 SG1C 16 81 03H +0.74 0.17 18%TW 0.11 0.18

• Tube plugged in 81 R23.

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Enclosur e 1

6. A description of the condition monitoring assessment and results, including the margin to the tube integrity performance criteria and comparison with the margin predicted to exist at the inspection by the previous forward-look ing tube integrity assessment (TS 5.6.9.c.3). Discuss any degradation that was not bounded by the prior operational assessment in terms of projected maximum flaw dimensions, minimum burst strength, and/or accident induced leak rate. Provide details of any in situ pressure test.

A condition monitoring (CM) assessment was performed as required by the Byron Unit 1 SG program. The tube degradation detected during the B1 R23 inspection was due to fan wear, lattice grid wear and foreign object wear at the tubesheet. The deepest indication for each mechanism met condition monitoring analytically as shown in Figures 2, 3 and 4a and 4b below. The margin to the structural and condition monitoring limit curve for each detected wear indication can be determined from Figures 2, 3 and 4a and 4b. The CM limit curves include uncertainties for material properties, NOE depth sizing, and the burst pressure relationship. Because the deepest flaws have a depth less than the conservativel y determined CM limit for all degradation mechanisms, the structural integrity performance criterion was met for the operating interval prior to B1 R23. A summary of the CM results from B1 R23 as compared to the predictions from the most recent prior inspection (B1 R20) is provided in Table 6.

Figure 2: Condition Monitoring Results for Fan Bar Wear 100 Note: CM and structural limit curves are 90 based on structural lengths and depths.

-= (l:l 80 Indication depths are conservatively plotted 3:

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Enclosur e 1 Figure 3: Condition Monitoring Results for Lattice Grid Wear 100 Note: CM and structural limit curves are 90 based on structural lengths and depths.

Indication depths are conservatively plotted using rnaximurn depths.

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Enclosure 1 Figure 4a: Condition Monitoring Results for Foreign Object Wear (ETSS 21998.1)

Note: CM and structural limit curves are 90 - --~---------- -~-~:-----, based on structural lengths and depths.

Indication depths are conservatively plotted using maximum depths.

_80

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--Structural Limit

- - Condition Monitoring Limit X

x Foreign Object Wear (21998.1) 0 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 Structural Length (Inches)

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Enclosure 1 Figure 4b: Condition Monitoring Results for Foreign Object Wear (ETSS 27901.1) 100 I I I

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Enclosure 1 Table 6: Comparison of Prior OA Projections to As-Found Results Parameter Prior OA Projection s*1 R23 As-Found Result l\1aximum for Fan Bar

\i\/ear 2 1°c,T\V as-found r*.1aximum Depth for Lattice (3rld V\1ear i',Jo actual d-irm(1e in c.;nJ\\'it-i of F~epe1:1t ForeIQn since forei9n object*::; i\Jo charn;ie :n measured depth Ob[ect \!\/ear Indications are no for 1-Jev flav.: ,von't chollenQe S 1°oT'vV a:~;-found

~;lruGturol or lears;r1~1e inte9rity l\1eets Cfvl limit,, 1:w1c1 The severest indication in 81 R23 had an estimated depth of 51 % TW from the plus-point probe exam. Since foreign object wear is a random event and there had only been 3 foreign object wear indications reported since SG replacement, there was no prediction for new foreign object wear made during the prior inspection in B1 R20.

Because volumetric wear indications will leak and burst at essentially the same pressure, accident-induced leakage integrity is also demonstrated. Operational leakage integrity was demonstrated by the absence of any detectable primary-to-secondary leakage during the operating interval prior to B1 R23. Because tube integrity was demonstrated analytically, in-situ pressure testing was not required nor performed during B1 R23. There were no tube pulls planned or performed during B1 R23.

7. The number of tubes plugged during the inspection outage (TS 5.6.9.c.4). Also, provide the tube location and reason for plugging.

Table 7 provides the number of tubes plugged for each degradation mechanism detected during 81 R23. One tube, SG 18 Row 2 Column 81 was plugged during B1 R23 for wear due to a foreign object at or above the 40% TW plugging limit.

Table 7: Number of Tubes Plugged for Each Degradation Mechanism in 81 R23 (TS 5.6.9.c.4)

Degradation Mechanism 1ASG 1BSG 1CSG 1DSG Total Fan Bar Wear 0 0 0 0 0 Lattice Grid Wear 0 0 0 0 0 Foreiqn Object Wear 0 1 0 0 1 Preventative 0 0 0 0 0 Total Plugged during B1 R23 0 1 0 0 1 E1-11 of24

Enclosure 1

8. An analysis summary of the tube integrity conditions predicted to exist at the next scheduled inspection (the forward-looking tube integrity assessment) relative to the applicable performance criteria, including the analysis methodology, inputs, and results (TS 5.6.9.d). The effective full power months of operation permitted for the current operational assessment.

Based on application of conservative U-bend support structure (fan bars) and lattice grid wear growth rates and foreign object susceptibility, the condition of the Byron Unit 1 SG tubes has been analyzed with respect to continued operability of the SGs without exceeding the SG tube integrity performance criteria at the next scheduled SG inspection in the Spring of 2026 (B1 R27).

Fan Bar Wear Operational Assessment (OA)

For the Fan Bar OA, the Mixed Arithmetic/Simplif ied Statistical method from Table 8-1 of Reference 4 was used. Using this method, a worst-case end-of-cycle (EOC) depth was projected by applying NOE uncertainties and a growth allowance to the deepest flaw returned to service. This projected EOC depth is then compared to an allowable EOC depth which is calculated using a Monte Carlo analysis which incorporates uncertainties in the burst pressure relationship and material properties.

The deepest fan bar indication returned to service was 21 % TW. The NOE sizing parameters for ETSS 96004.3 are a slope of 0.97, an intercept of 2.50, and a standard error of 3.10.

Using the slope and intercept, a best estimate real depth of 22.9% TW (0.97 x 21 + 2.5) is obtained for an indication with a measured depth of 21 %TW.

The standard error of 3.10 from ETSS 96004.3 is the technique uncertainty. Adjusting this value upward to an upper 95th percentile gives an NOE uncertainty of 5.1 % TW (3.10 x 1.645). Adding this uncertainty to the best estimate value of 22.9% TW from the previous paragraph yields a bounding real depth of 28.0% TW (22.9 + 5.1) returned to service.

This hypothesized real depth of 28.0% TW must then be grown at an upper 95th growth rate for the next inspection interval. For this operational assessment, wear at support structures is being evaluated for five fuel cycles of 1.5 EFPY each. The highest upper 95th percentile growth rate for any steam generator over the last two inspection intervals is 0.96% TW per EFPY. Since the growth rates are so low for fan bar wear at Byron Unit 1, a conservative growth rate of 1.5%TW per EFPY was used in the operational assessment. This value conservatively bounds the maximum growth rate from the last two operating intervals.

Applying a growth of 11.3% TW (1.5 x 7.5) gives a bounding real depth at the end of the upcoming inspection interval of 39.3% TW (28.0 + 11.3). For a flaw with an assumed bounding length of 1.7 inches, the allowable structural depth at the end of the upcoming inspection cycle is 59.2% TW. Since the projected depth of 39.3% TW is less than 59.2% TW, there is reasonable assurance that structural integrity will be maintained for lattice grid wear for the next five cycles of operation.

Lattice Grid Wear OA For lattice grid wear, the OA was performed in a manner similar to what was done for fan bar wear. Unlike fan bar wear, however, there is too little data from which to calculate a reliable upper 95 th percentile growth rate. There were thirteen lattice grid wear indications reported during the B 1R23 outage. The deepest indication measured 11 %TW with a bobbin probe. All thirteen E1-12 of 24

Enclosur e 1 indications were also reported in the previous outage (B 1R20). The largest growth was 4% TW over an operating interval of 4.262 EFPY giving a maximum growth rate of 0.94% TW per EFPY.

Similar to fan bar wear, since the growth rates for lattice grid wear are so low, a conservative growth rate of 1.5% TW per EFPY will be used for this operational assessment.

The lattice grid flaws are typically short and occur at one edge of a lattice grid. However, since length measurements were not made for these indications, a bounding flaw length of 3.15 inches will be used in the analysis. This length was obtained from the "high bar" lattice grids which are 3.15 inches tall. This is very conservative based on the flaw lengths observed in previous outages.

Using the same Mixed Arithmetic/Sim plified Statistical method Table 8-1 of Reference 4 and the same bobbin ETSS (96004.3), a best estimate real depth of 13.2% TW (0.97 x 11 + 2.5) is obtained for a measured depth of 11 % TW. Applying upper 95 th percentile NOE uncertainties yields a bounding real depth of 18.3% TW (13.2 + 1.645 x 3.1) returned to service. Further applying a growth rate of 1.5% TW per EFPY (as discussed above) over 7.5 EFPY gives a projected real EOC depth of 29.6% TW (18.3 + 1.5 x 7.5). For a flaw with an assumed bounding length of 3.15 inches, the allowable structural depth at the end of the upcoming inspection cycle is 57.8% TW. Since the projected depth of 29.6% TW is less than 57.8% TW, there is reasonable assurance that structural integrity will be maintained for lattice grid wear for the next five cycles of operation.

Tube Wear from Existing, Remaining and New Foreign Objects OA All of the foreign objects that were classified as potentially causing tubes wear, Priority 1, were removed from the steam generators. The remaining objects were classified as Priority 3, not potentially causing tube wear based on their composition, size and/or low-flow location.

This included objects such as sludge rocks and tube scale which are considered benign based on no known history of causing tube wear. In addition, one metallic object was evaluated for potential wear based on a location in a low velocity zone, making it highly unlikely to cause any detectable tube wear. A summary of the OA results predicted at the next inspection (or longer) is provided in Table 8.

Table 8: Comparison of OA Projections at Next SG Inspection to Structural Limits Degradation Mechanism Maximum depth(%) Predicted Structural limit (wear) at Next Inspection depth(%)

Fan Bar U-bend support 39.3 59.2 Lattice Grid support 29.6 57.8 Existing FO Wear No Growth (FO removed) 60-75% (technique and length dependent)

Remaining FOs < 20%TWWea r 60-75% (technique and length dependent)

New FOs Limiting flaw won't challenge 60-75% (technique and structural or leakage integrity length dependent) after 4 operatinq cycles

9. The number and percentage of tubes plugged to date, and the effective plugging percentage in each SG (TS 5.6.9.e).

Table 9 shows the number of tubes plugged before and after the 81 R23 outage and the percentage of tubes currently plugged (total and effective). No sleeves have been installed in Byron Unit 1.

E1-13 of 24

Enclosure 1 Table 9: Tube Plugging to Date (Number and Percentage per SG) (TS 5.6.9.e) 1ASG 1BSG 1CSG 1DSG Total Pluaaed prior to B1 R23 1 1 14 5 21 Pluaaed durinq B1 R23 0 1 0 0 1 Stabilized during B1 R23 0 0 0 0 0 Total Plugged through B1 R23 1 2 14 5 22 Total/Effective Percent Pluqqed throuqh B 1R23 0.02% 0.03% 0.21% 0.08% 0.08%

10. The results of any SG secondary-side inspection (TS 5.6.9.f). The number, type, and location (if available) of loose parts that could damage tubes removed or left in service in each SG.

Secondary Side Scope:

• Sludge lancing in all four SGs including "post sludge lance" Foreign Object Search and Retrieval (FOSAR)

• Feedring Inspection (1 DSG)

• Steam Drum Internal Inspections (1 C & 1DSG)

• Upper Bundle Inspection (1 DSG)

Secondary Side Visual Inspections of Tubesheet and FOSAR Secondary side tubesheet visual inspections were performed following sludge lancing activities in all four SGs. High flow regions of the annulus, no tube lane and periphery (6-8 tubes deep) were visually inspected for foreign material. Additionally, eight columns for the full depth of the tube bundle interior

("kidney" region) were evaluated for sludge lancing effectiveness and sludge accumulation.

Secondary side foreign object search and retrieval (FOSAR) inspections at the tubesheet were performed in all four SGs. This included visual examination of tube bundle periphery tubes from the hot leg and cold leg annulus and center no tube lane. Fourteen (14) foreign object locations (7 metallic) were identified by visual inspections and/or eddy current examinations and are summarized in Table 10. Five foreign objects were classified as Priority 1 and were removed from the steam generators. Nine additional foreign objects were classified as Priority 3 and were left in the bundle.

Two of the Priority 1 foreign objects were pieces of retainer springs from feedwater regulating valves. The retainer springs pieces are each about 4" long. One spring (ID 1B001) caused wear scars in five neighboring tubes, one of which required plugging. None of the other foreign objects caused detectable tube wear detected by the bobbin or array examinations. The retrieved foreign objects consisted of the 2 retainer spring pieces, bent metal material, weld slag, and a metal clip.

The other objects were classified as Priority 3 parts and were left in the bundle. These objects consisted of sludge rocks, tube scale, and a wire bristle and are considered benign based on having no known history of causing tube wear in the industry. In addition, one small metallic object (1 B007) was identified in a low velocity zone, evaluated for the potential to cause detectable tube wear, classified as Priority 3, and left in place based on an analysis that demonstrated its acceptability for continued operation without exceeding the performance criteria within 72 EFPM (4-cycles) of operation.

E1-14 of 24

Enclosur e 1 A top of tubesheet in-bundle visual inspection in a sample of tube columns was also performed in each SG for the purpose of assessing and trending the level of hardened deposit buildup in the kidney region.

Table 10: Foreign Object Summary SG Row Col Leg Found Priority Elev Ref ID Priority Status Material By Basis 1 82 2 81 Foreign SG1B 3 82 HL TTS +0.5 18001 ECT 1 Retainer Object Retrieved 4 81 Spring Wear 5 82 106 101 Visual Bent SG1B 107 102 HL TTS +0.5 18002 Wear

& 1 Retrieved Metal 108 101 Analysis ECT Material 11 84 Wear Weld SG 1B CL TTS 18003 Visual 1 Retrieved 10 85 Analysis Slaq 108 95 Sludge SG1B HL TTS 18004 Visual 3 Benign Remains 109 96 Rock 117 79 SG1B HL TTS 18005 Visual 3 Benign Remains Scale 118 80 49 10 ECT Sludge SG1B HL TTS +7 18006 3 Benign Remains 51 10 PLP Rock Wear 69 60 Analysis Metallic SG1B CL TTS 18007 Visual 3 Remains 70 61 <20%TW Object

@7.5 vrs 16 137 ECT Wear Metal SG1B CL TTS +5 18008 1 Retrieved 15 138 PLP Analysis Clip 59 16 60 15 61 16 62 15 SG1C 63 16 ECT Wear Retainer CL TTS +3 to 1C001 1 Retrieved 64 15 PLP Analysis Spring

+6 65 16 66 15 67 16 54 84 Wire SG1C CL TTS 1C002 Visual 3 Mobile Remains 55 85 Bristle 95 109 Sludge SG 1D CL TTS 10001 Visual 3 Benign Remains 96 110 Rock 108 55 SG 1D CL TTS 1D002 Visual 3 Benign Remains Scale 109 56 59 14 Sludge SG 1D CL TTS 1D003 Visual 3 Benign Remains 58 15 Rock 60 103 SG 1D CL TTS 1D004 Visual 3 Benign Remains Scale 60 104 E1-15of24

Enclosure 1 Visual inspection of the feedrinq, upper tube bundle and the lattice grids During the Feedring inspections in the 1D SG, no anomalous structural conditions or foreign objects were observed. Additionally, no erosion or component degradation was identified.

During visual inspections in the 1 D SG of the lattice grids at the uppermost (9th) support location for the hot leg and cold leg some deposit accumulation was identified on the hot leg side at the lattice grids and on the tube surfaces. The corresponding cold leg was relatively free of deposit accumulation at the lattice grids and on the tube surfaces, as evidenced by sharply defined lattice grid edges and shiny tube surfaces. No degradation was noted.

Steam drum visual inspections Steam drum visual inspections were performed in the 1C and 1D SGs. No evidence of foreign material, degradation or structural distortion was observed in the steam drum. The primary and secondary moisture separators were in good condition. Steam Drum Inspections were performed on 2 SGs (1 C and 1D). The steam nozzle internals, secondary deck and hardware, internals of 10 secondary moisture separators internals and internals of 5 primary moisture separators in each SG were visually inspected for degradation. None was found.

No repairs were required for the secondary side inspection, and it was concluded that a 4-cycle inspection interval was justified with no adverse consequences for all 4 SGs.

11. The scope, method, and results of secondary-side cleaning performed in each SG Prior to the secondary side FOSAR inspections, sludge, scale, foreign objects, and other deposit accumulations at the top of the tubesheet were removed as part of the top of tubesheet high pressure water lancing process. The weight of deposits removed from each SG by this cleaning process is provided in Table 11. Given Byron Unit 1 had operated 3 cycles from the last sludge lancing in 81 R20, the amount of accumulation per SG was minimal. A visual inspection of the upper lattice grids showed no significant deposit accumulation and no conditions that would adversely impact tube integrity.

Table 11: 81 R23 SG Deposit Removal Weights SG Weight SG1A 15.0lbs SG18 15.0 lbs SG1C 19.0 lbs SG1D 9.5 lbs All SGs 58.5 lbs E1-16 of 24

Enclosure 1

12. The results of primary side component visual inspections performed in each SG.

Visual Inspection of Installed Tube Plugs and Tube-to-Tubesheet Welds All previously installed tube plugs (42) were visually inspected for signs of degradation and leakage. The tube-to-tubesheet welds were visually inspected during eddy current. No degradation or anomalies were found.

SG Channel Head Bowl Visual Inspections Each SG hot and cold leg primary channel head was visually examined in accordance with the recommendations of Westinghouse NSAL 12-01 and NRC IN 2013-20 for evidence of breaches in the cladding or cracking in the divider to channel head weld and for evidence of wastage of the carbon steel channel head. No evidence of cladding breaches, wastage or corrosion in the channel head was identified. Also, no cracking in the divider to channel head weld was identified.

References

1. CEG letter to NRC, RS-22-086, Application to Revise Technical Specifications to Adopt TSTF-577, "Revised Frequencies for Steam Generator Tube Inspections",

dated August 10, 2022 (ML22222A068)

2. NRC letter to CEG, "BYRON STATION, UNIT NOS. 1 AND 2 - ISSUANCE OF AMENDMENTS 231 AND 231 RE: ADOPTION OF TSTF-577, "REVISED FREQUENCIES FOR STEAM GENERATOR TUBE INSPECTIONS," REVISION 1 (EPID L-2022-LLA-0115)",

dated December 28, 2022 (ML22305A699)

3. Exelon Generation letter to NRC, "Byron Station, Unit 1 Steam Generator Tube Inspection Report for Refueling Outage 23," dated September 10, 2020 (ML20253A042)

4. Steam Generator Management Program: Steam Generator Integrity Assessment Guidelines, Revision 5, EPRI, Palo Alto, CA, December 2021 (3002020909)

5. Letter from H. Welt (Constellation Energy Generation, LLC) to NRC, "Byron Station, Unit 1 and Unit 2, Steam Generator Tube Inspection Report to Reflect TSTF-577 Reporting Requirements," dated April 6, 2023 (ADAMS Accession No. ML23096A144)

E1-17of24

Enclosure 1 ATTACHMEN T A - Fan Bar Wear Indications (SG 1A)

Row Col Volts Deg Ind Per Chn Locn lnchl lnch2 BegT EndT PDia PType 78 51 0.8 0 PCT 13 P2 F05 0.73 TEC TEH 0.56 CBAFN 66 55 0.22 0 PCT 5 P2 F05 -1.08 TEC TEH 0.56 CBAFN 70 55 0.31 0 PCT 6 P2 F03 0.95 TEC TEH 0.56 CBAFN 53 58 0.23 0 PCT 4 P2 F06 0.54 TEC TEH 0.56 CBAFN 75 58 0.46 0 PCT 8 P2 F05 -0.7 TEC TEH 0.56 CBAFN 86 59 0.21 0 PCT 4 P2 F04 1.66 TEC TEH 0.56 CBAFN 73 62 0.19 0 PCT 5 P2 F05 -0.73 TEC TEH 0.56 CBAFN 72 63 0.21 0 PCT 5 P2 F05 -1.41 TEC TEH 0.56 CBAFN 100 63 0.32 0 PCT 6 P2 F05 -1.24 TEC TEH 0.56 CBAFN 112 63 0.77 0 PCT 13 P2 F04 0.56 TEC TEH 0.56 CBAFN 64 65 0.55 0 PCT 10 P2 F06 0.76 TEC TEH 0.56 CBAFN 80 67 0.31 0 PCT 6 P2 F06 -1.21 TEC TEH 0.56 CBAFN 84 69 0.27 0 PCT 5 P2 F06 -0.52 TEC TEH 0.56 CBAFN 86 69 0.44 0 PCT 8 P2 F06 -0.42 TEC TEH 0.56 CBAFN 88 69 0.39 0 PCT 7 P2 F06 -0.73 TEC TEH 0.56 CBAFN 96 69 0.72 0 PCT 11 P2 F05 -1.2 TEC TEH 0.56 CBAFN 96 69 0.75 0 PCT 12 P2 F06 -0.88 TEC TEH 0.56 CBAFN 89 70 0.17 0 PCT 3 P2 F09 -0.53 TEC TEH 0.56 CBAFN 86 71 0.33 0 PCT 6 P2 F05 -1.47 TEC TEH 0.56 CBAFN 86 71 0.34 0 PCT 6 P2 F05 -0.61 TEC TEH 0.56 CBAFN 86 71 0.9 0 PCT 14 P2 F06 0.94 TEC TEH 0.56 CBAFN 114 71 0.34 0 PCT 6 P2 F05 -1.5 TEC TEH 0.56 CBAFN 115 78 0.63 0 PCT 10 P2 F05 1.74 TEC TEH 0.56 CBAFN 113 80 0.55 0 PCT 9 P2 F05 -1.11 TEC TEH 0.56 CBAFN 60 93 0.3 0 PCT 4 P2 F06 -1.77 TEC TEH 0.56 CBAFN E1-18 of 24

Enclosur e 1 ATTACHM ENT A - Fan Bar Wear Indications 'SG 1B)

Row Col Volts Deg Ind Per Chn Locn lnchl lnch2 BegT EndT PDia PType 79 52 0.18 0 PCT 4 P2 F05 0.99 TEC TEH 0.56 CBAFN 102 53 0.4 0 PCT 8 P2 F04 -1.37 TEC TEH 0.56 CBAFN 102 53 0.39 0 PCT 7 P2 F04 0.85 TEC TEH 0.56 CBAFN 102 53 0.42 0 PCT 8 P2 F05 -1.3 TEC TEH 0.56 CBAFN 102 53 0.49 0 PCT 9 P2 F05 1.35 TEC TEH 0.56 CBAFN 102 53 0.64 0 PCT 11 P2 F06 -0.72 TEC TEH 0.56 CBAFN 102 53 0.59 0 PCT 10 P2 F06 1.36 TEC TEH 0.56 CBAFN 42 55 0.18 0 PCT 4 P2 F05 0.44 TEC TEH 0.56 CBAFN 109 56 0.3 0 PCT 7 P2 F05 -0.51 TEC TEH 0.56 CBAFN 109 56 0.22 0 PCT 6 P2 F07 0.77 TEC TEH 0.56 CBAFN 109 56 0.32 0 PCT 8 P2 F08 1.81 TEC TEH 0.56 CBAFN 64 57 0.94 0 PCT 16 P2 F06 -1.14 TEC TEH 0.56 CBAFN 75 60 0.47 0 PCT 10 P2 F02 -1.68 TEC TEH 0.56 CBAFN 60 61 0.58 0 PCT 11 P2 F06 -0.57 TEC TEH 0.56 CBAFN 67 62 0.62 0 PCT 11 P2 FOl -1.58 TEC TEH 0.56 CBAFN 81 62 0.4 0 PCT 8 P2 F06 0.95 TEC TEH 0.56 CBAFN 60 63 0.22 0 PCT 4 P2 F05 0.48 TEC TEH 0.56 CBAFN 66 63 0.24 0 PCT 5 P2 F04 1.41 TEC TEH 0.56 CBAFN 68 63 0.28 0 PCT 6 P2 F05 -1.54 TEC TEH 0.56 CBAFN 82 63 0.8 0 PCT 13 P2 F06 1.61 TEC TEH 0.56 CBAFN 86 63 0.8 0 PCT 13 P2 F05 -0.89 TEC TEH 0.56 CBAFN 86 63 1.63 0 PCT 21 P2 F06 1.46 TEC TEH 0.56 CBAFN 88 63 0.54 0 PCT 10 P2 F08 0.59 TEC TEH 0.56 CBAFN 106 63 0.85 0 PCT 13 P2 F05 -1.15 TEC TEH 0.56 CBAFN 106 63 0.4 0 PCT 7 P2 F05 1.17 TEC TEH 0.56 CBAFN 106 63 0.58 0 PCT 10 P2 F07 1.66 TEC TEH 0.56 CBAFN 114 63 0.27 0 PCT 7 P2 F05 1.51 TEC TEH 0.56 CBAFN 114 63 0.33 0 PCT 8 P2 F06 0.73 TEC TEH 0.56 CBAFN 114 63 0.55 0 PCT 12 P2 F07 1.76 TEC TEH 0.56 CBAFN 114 63 0.44 0 PCT 10 P2 F08 0.81 TEC TEH 0.56 CBAFN 65 64 0.54 0 PCT 11 P2 F05 0.65 TEC TEH 0.56 CBAFN 77 64 0.79 0 PCT 14 P2 F05 -1.34 TEC TEH 0.56 CBAFN 77 64 0.35 0 PCT 8 P2 F05 0.66 TEC TEH 0.56 CBAFN 91 64 0.67 0 PCT 11 P2 F06 -0.94 TEC TEH 0.56 CBAFN 97 64 0.53 0 PCT 9 P2 F05 1.08 TEC TEH 0.56 CBAFN 97 64 1 0 PCT 15 P2 F06 -0.48 TEC TEH 0.56 CBAFN 113 64 0.44 0 PCT 8 P2 F04 0.85 TEC TEH 0.56 CBAFN 113 64 0.35 0 PCT 6 P2 F07 0.71 TEC TEH 0.56 CBAFN 52 65 0.36 0 PCT 8 P2 F04 -1.67 TEC TEH 0.56 CBAFN E1-19of24

Enclosur e 1 ATTACHMENT A - Fan Bar Wear Indications SG 1B)

Row Col Volts Deg Ind Per Chn Locn lnchl lnch2 BegT EndT PDia PType 66 65 0.22 0 PCT 5 P2 F03 -1.51 TEC TEH 0.56 CBAFN 74 65 0.47 0 PCT 10 P2 F06 1.64 TEC TEH 0.56 CBAFN 76 65 0.47 0 PCT 10 P2 F05 0.49 TEC TEH 0.56 CBAFN 90 65 0.58 0 PCT 10 P2 F05 1.48 TEC TEH 0.56 CBAFN 90 65 0.36 0 PCT 7 P2 F06 -1.29 TEC TEH 0.56 CBAFN 106 65 0.28 0 PCT 6 P2 F05 1.76 TEC TEH 0.56 CBAFN 106 65 0.35 0 PCT 7 P2 F06 -1.27 TEC TEH 0.56 CBAFN 110 65 0.67 0 PCT 12 P2 F06 0.9 TEC TEH 0.56 CBAFN 112 65 0.57 0 PCT 10 P2 F05 1.87 TEC TEH 0.56 CBAFN 112 65 0.61 0 PCT 11 P2 F06 -1.47 TEC TEH 0.56 CBAFN 67 66 0.33 0 PCT 7 P2 F06 0.79 TEC TEH 0.56 CBAFN 79 66 0.39 0 PCT 7 P2 F06 -1.63 TEC TEH 0.56 CBAFN 95 66 0.48 0 PCT 9 P2 F05 -0.78 TEC TEH 0.56 CBAFN 109 66 0.56 0 PCT 10 P2 F04 -1.12 TEC TEH 0.56 CBAFN 109 66 0.64 0 PCT 11 P2 F04 1.12 TEC TEH 0.56 CBAFN 109 66 0.65 0 PCT 11 P2 F05 1.27 TEC TEH 0.56 CBAFN 109 66 0.68 0 PCT 12 P2 F08 -1.57 TEC TEH 0.56 CBAFN 113 66 0.6 0 PCT 11 P2 F03 1.16 TEC TEH 0.56 CBAFN 113 66 0.6 0 PCT 11 P2 F05 -1.25 TEC TEH 0.56 CBAFN 91 68 0.49 0 PCT 9 P2 F07 1.68 TEC TEH 0.56 CBAFN 97 68 0.7 0 PCT 11 P2 F06 -1.23 TEC TEH 0.56 CBAFN 46 69 0.4 0 PCT 8 P2 F06 0.79 TEC TEH 0.56 CBAFN 88 69 0.54 0 PCT 10 P2 F05 1.59 TEC TEH 0.56 CBAFN 63 70 0.33 0 PCT 7 P2 F05 1.14 TEC TEH 0.56 CBAFN 109 70 0.44 0 PCT 7 P2 F05 0.68 TEC TEH 0.56 CBAFN 43 72 0.48 0 PCT 9 P2 F06 -0.76 TEC TEH 0.56 CBAFN 95 72 0.44 0 PCT 7 P2 F05 0.97 TEC TEH 0.56 CBAFN 92 73 0.41 0 PCT 7 P2 F06 1.65 TEC TEH 0.56 CBAFN 101 74 0.45 0 PCT 8 P2 F05 1.73 TEC TEH 0.56 CBAFN 88 75 0.45 0 PCT 8 P2 F06 -0.55 TEC TEH 0.56 CBAFN 100 75 0.26 0 PCT 5 P2 F06 1.7 TEC TEH 0.56 CBAFN 51 76 0.36 0 PCT 6 P2 F05 1.53 TEC TEH 0.56 CBAFN 97 76 0.55 0 PCT 9 P2 F09 -0.43 TEC TEH 0.56 CBAFN 109 76 0.53 0 PCT 9 P2 F05 -0.41 TEC TEH 0.56 CBAFN 109 76 0.83 0 PCT 13 P2 F06 1.47 TEC TEH 0.56 CBAFN 109 76 0.52 0 PCT 9 P2 F07 -1.02 TEC TEH 0.56 CBAFN 109 76 0.4 0 PCT 7 P2 F07 0.84 TEC TEH 0.56 CBAFN 109 76 0.19 0 PCT 4 P2 F09 0.47 TEC TEH 0.56 CBAFN 94 77 0.38 0 PCT 7 P2 F07 1.85 TEC TEH 0.56 CBAFN E1-20 of 24

Enclosure 1 ATTACHMENT A - Fan Bar Wear Indications (SG 1B)

Row Col Volts Deg Ind Per Chn Locn lnchl lnch2 BegT EndT PDia PType 104 77 0.25 0 PCT 5 P2 F05 -1.73 TEC TEH 0.56 CBAFN 108 77 0.22 0 PCT 4 P2 F07 -0.66 TEC TEH 0.56 CBAFN 110 77 0.42 0 PCT 7 P2 F05 1.14 TEC TEH 0.56 CBAFN 109 78 0.24 0 PCT 5 P2 F02 -1.57 TEC TEH 0.56 CBAFN 56 79 0.26 0 PCT 5 P2 F06 -0.64 TEC TEH 0.56 CBAFN 114 79 0.27 0 PCT 5 P2 F05 1.44 TEC TEH 0.56 CBAFN 103 80 0.35 0 PCT 6 P2 F06 0.38 TEC TEH 0.56 CBAFN 111 80 0.44 0 PCT 7 P2 F06 0.69 TEC TEH 0.56 CBAFN 82 81 0.32 0 PCT 6 P2 F05 -1.84 TEC TEH 0.56 CBAFN 94 81 0.66 0 PCT 10 P2 F05 1.82 TEC TEH 0.56 CBAFN 84 83 0.47 0 PCT 9 P2 F05 -1.66 TEC TEH 0.56 CBAFN 35 84 0.24 0 PCT 4 P2 F05 -0.63 TEC TEH 0.56 CBAFN 105 84 0.36 0 PCT 7 P2 F05 -0.49 TEC TEH 0.56 CBAFN 94 85 0.26 0 PCT 5 P2 F06 -1.23 TEC TEH 0.56 CBAFN 110 85 0.66 0 PCT 11 P2 F05 0.76 TEC TEH 0.56 CBAFN 65 86 0.43 0 PCT 8 P2 F06 0.7 TEC TEH 0.56 CBAFN 64 87 0.41 0 PCT 7 P2 F05 -0.84 TEC TEH 0.56 CBAFN 65 88 0.5 0 PCT 9 P2 F06 -0.4 TEC TEH 0.56 CBAFN 69 88 0.3 0 PCT 6 P2 F06 -0.62 TEC TEH 0.56 CBAFN 59 90 0.33 0 PCT 6 P2 F05 -0.72 TEC TEH 0.56 CBAFN 87 90 0.52 0 PCT 9 P2 F06 1.61 TEC TEH 0.56 CBAFN 113 90 0.2 0 PCT 4 P2 F07 0.92 TEC TEH 0.56 CBAFN 109 92 0.25 0 PCT 5 P2 F04 -1.59 TEC TEH 0.56 CBAFN 63 94 0.33 0 PCT 5 P2 F06 1.66 TEC TEH 0.56 CBAFN 85 98 0.13 0 PCT 3 P2 F07 1.78 TEC TEH 0.56 CBAFN 102 107 0.41 0 PCT 8 P2 F05 -0.7 TEC TEH 0.56 CBAFN E1-21 of 24

Enclosur e 1 ATTACHMENT A - Fan Bar Wear Indications (SG 1C)

Row Col Volts Deg Ind Per Chn Locn lnchl lnch2 BegT EndT PDia PType 47 14 0.35 0 PCT 6 P2 F05 0.92 TEC TEH 0.56 CBAFN 41 38 0.25 0 PCT 4 P2 F05 -1.69 TEC TEH 0.56 CBAFN 45 46 0.24 0 PCT 4 P2 F05 -1.77 TEC TEH 0.56 CBAFN 56 47 0.2 0 PCT 3 P2 F04 0.74 TEC TEH 0.56 CBAFN 87 64 0.24 0 PCT 4 P2 F05 1.36 TEC TEH 0.56 CBAFN 40 67 0.18 0 PCT 3 P2 F05 0.79 TEC TEH 0.56 CBAFN 48 69 0.13 0 PCT 3 P2 F06 0.76 TEC TEH 0.56 CBAFN 70 71 0.24 0 PCT 6 P2 F05 1.5 TEC TEH 0.56 CBAFN 71 72 0.28 0 PCT 6 P2 F07 -0.51 TEC TEH 0.56 CBAFN 63 76 0.25 0 PCT 6 P2 F05 1.83 TEC TEH 0.56 CBAFN 102 77 0.18 0 PCT 3 P2 F04 -1.82 TEC TEH 0.56 CBAFN 109 78 0.23 0 PCT 4 P2 F05 -1.03 TEC TEH 0.56 CBAFN 52 79 0.23 0 PCT 5 P2 F05 -1.77 TEC TEH 0.56 CBAFN 98 79 0.45 0 PCT 9 P2 F05 -1.62 TEC TEH 0.56 CBAFN 113 80 0.75 0 PCT 14 P2 F04 1.34 TEC TEH 0.56 CBAFN 113 80 0.2 0 PCT 5 P2 F05 0.7 TEC TEH 0.56 CBAFN 60 81 0.23 0 PCT 4 P2 F05 1.53 TEC TEH 0.56 CBAFN 76 81 0.3 0 PCT 5 P2 F05 -1.78 TEC TEH 0.56 CBAFN 76 81 0.52 0 PCT 9 P2 F06 -1 TEC TEH 0.56 CBAFN 94 81 0.53 0 PCT 9 P2 F05 -1.38 TEC TEH 0.56 CBAFN 97 84 0.5 0 PCT 10 P2 F05 -0.68 TEC TEH 0.56 CBAFN 97 84 0.51 0 PCT 10 P2 F06 -0.91 TEC TEH 0.56 CBAFN 109 84 0.66 0 PCT 12 P2 F04 0.59 TEC TEH 0.56 CBAFN 109 84 0.18 0 PCT 4 P2 F05 0.64 TEC TEH 0.56 CBAFN 109 84 0.48 0 PCT 9 P2 F06 1.39 TEC TEH 0.56 CBAFN 52 85 0.34 0 PCT 5 P2 F05 0.69 TEC TEH 0.56 CBAFN 90 85 0.61 0 PCT 9 P2 F05 -1.57 TEC TEH 0.56 CBAFN 48 87 0.17 0 PCT 4 P2 F05 -1.79 TEC TEH 0.56 CBAFN 100 89 0.38 0 PCT 6 P2 F05 -0.75 TEC TEH 0.56 CBAFN 53 92 0.44 0 PCT 7 P2 F05 -0.98 TEC TEH 0.56 CBAFN 99 94 0.43 0 PCT 6 P2 F03 0.75 TEC TEH 0.56 CBAFN E1-22 of 24

Enclosure 1 ATTACHMEN T A - Fan Bar Wear Indications (SG 1D)

Row Col Volts Deg Ind Per Chn Locn lnchl lnch2 BegT EndT PDia PType 102 55 0.43 0 PCT 10 P2 F05 1.58 TEC TEH 0.56 CBAFN 80 57 0.21 0 PCT 5 P2 F06 -0.92 TEC TEH 0.56 CBAFN 106 57 0.19 0 PCT 4 P2 F07 -1. 7 TEC TEH 0.56 CBAFN 112 57 0.22 0 PCT 5 P2 F08 -1.79 TEC TEH 0.56 CBAFN 113 58 0.41 0 PCT 8 P2 F06 0.69 TEC TEH 0.56 CBAFN 78 59 0.23 0 PCT 6 P2 F05 1.75 TEC TEH 0.56 CBAFN 78 59 0.6 0 PCT 13 P2 F06 1.72 TEC TEH 0.56 CBAFN 86 59 0.42 0 PCT 10 P2 F05 1.79 TEC TEH 0.56 CBAFN 86 59 0.36 0 PCT 9 P2 F06 1.33 TEC TEH 0.56 CBAFN 98 59 0.35 0 PCT 8 P2 F05 1.82 TEC TEH 0.56 CBAFN 100 59 0.42 0 PCT 10 P2 F05 1.76 TEC TEH 0.56 CBAFN 107 60 0.28 0 PCT 7 P2 F05 1.62 TEC TEH 0.56 CBAFN 107 60 0.72 0 PCT 14 P2 F06 -0.48 TEC TEH 0.56 CBAFN 107 60 0.25 0 PCT 7 P2 F07 0.84 TEC TEH 0.56 CBAFN 70 61 0.27 0 PCT 7 P2 F07 1.92 TEC TEH 0.56 CBAFN 112 61 0.59 0 PCT 11 P2 F06 1.34 TEC TEH 0.56 CBAFN 91 62 0.24 0 PCT 5 P2 F06 0.7 TEC TEH 0.56 CBAFN 102 63 0.62 0 PCT 13 P2 F05 1.3 TEC TEH 0.56 CBAFN 102 63 0.22 0 PCT 6 P2 F06 -1.38 TEC TEH 0.56 CBAFN 106 63 0.39 0 PCT 9 P2 F04 0.98 TEC TEH 0.56 CBAFN 106 63 0.35 0 PCT 9 P2 F05 1.21 TEC TEH 0.56 CBAFN 77 64 0.35 0 PCT 8 P2 F07 0.74 TEC TEH 0.56 CBAFN 113 64 0.18 0 PCT 4 P2 F04 -1.6 TEC TEH 0.56 CBAFN 113 64 0.47 0 PCT 9 P2 F05 -0.77 TEC TEH 0.56 CBAFN 113 64 0.29 0 PCT 6 P2 F06 1.88 TEC TEH 0.56 CBAFN 113 64 0.34 0 PCT 7 P2 F09 -0.74 TEC TEH 0.56 CBAFN 72 65 0.54 0 PCT 11 P2 F06 1.45 TEC TEH 0.56 CBAFN 76 65 0.5 0 PCT 10 P2 F06 1.77 TEC TEH 0.56 CBAFN 80 65 0.32 0 PCT 7 P2 F06 1.83 TEC TEH 0.56 CBAFN 84 65 0.49 0 PCT 10 P2 F06 1.77 TEC TEH 0.56 CBAFN 106 65 0.64 0 PCT 12 P2 F06 -1.31 TEC TEH 0.56 CBAFN 106 65 0.64 0 PCT 12 P2 F07 1.78 TEC TEH 0.56 CBAFN 89 66 0.28 0 PCT 7 P2 F06 1.27 TEC TEH 0.56 CBAFN 99 66 0.43 0 PCT 10 P2 F05 1.41 TEC TEH 0.56 CBAFN 105 66 0.46 0 PCT 11 P2 F05 1.75 TEC TEH 0.56 CBAFN 82 67 0.5 0 PCT 11 P2 F06 1.39 TEC TEH 0.56 CBAFN 90 67 0.5 0 PCT 11 P2 F06 1.44 TEC TEH 0.56 CBAFN 92 67 0.45 0 PCT 11 P2 F06 1.3 TEC TEH 0.56 CBAFN 102 67 0.56 0 PCT 13 P2 F06 1.64 TEC TEH 0.56 CBAFN E1-23 of 24

Enclosure 1 ATTACHMENT A - Fan Bar Wear Indications (SG 1 D)

Row Col Volts Deg Ind Per Chn Locn lnchl lnch2 BegT EndT PDia PType 106 67 0.22 0 PCT 6 P2 F05 -0.8 TEC TEH 0.56 CBAFN 106 67 0.45 0 PCT 11 P2 F06 1.78 TEC TEH 0.56 CBAFN 108 67 0.14 0 PCT 4 P2 F08 1.95 TEC TEH 0.56 CBAFN 112 67 0.17 0 PCT 5 P2 F05 -1.08 TEC TEH 0.56 CBAFN 73 68 0.19 0 PCT 5 P2 F05 -0.55 TEC TEH 0.56 CBAFN 103 68 0.71 0 PCT 13 P2 F06 0.87 TEC TEH 0.56 CBAFN 107 68 0.37 0 PCT 8 P2 F06 0.67 TEC TEH 0.56 CBAFN 113 68 0.44 0 PCT 9 P2 F06 1.09 TEC TEH 0.56 CBAFN 112 69 0.42 0 PCT 9 P2 F04 0.7 TEC TEH 0.56 CBAFN 112 69 0.58 0 PCT 11 P2 F05 -1.42 TEC TEH 0.56 CBAFN 112 69 0.77 0 PCT 14 P2 F06 1.18 TEC TEH 0.56 CBAFN 83 76 0.3 0 PCT 7 P2 F05 -1.14 TEC TEH 0.56 CBAFN 58 79 0.31 0 PCT 8 P2 F06 0.65 TEC TEH 0.56 CBAFN 69 82 0.44 0 PCT 10 P2 F05 -0.96 TEC TEH 0.56 CBAFN 67 84 0.41 0 PCT 9 P2 F06 1.41 TEC TEH 0.56 CBAFN 75 84 0.37 0 PCT 8 P2 F06 1.8 TEC TEH 0.56 CBAFN 79 84 0.37 0 PCT 8 P2 F05 0.94 TEC TEH 0.56 CBAFN 65 90 0.28 0 PCT 7 P2 F06 1.66 TEC TEH 0.56 CBAFN 70 95 0.21 0 PCT 5 P2 F06 -1.25 TEC TEH 0.56 CBAFN 63 104 0.13 0 PCT 3 P2 F06 1.35 TEC TEH 0.56 CBAFN E1-24 of 24

Enclosu re 2 Byron Station, Unit 2 Updated Steam Generat or Tube Inspectio n Report

Enclosure 2 Byron Station, Unit 2 Updated Steam Generator Tube Inspection Report Introduction In Reference 1, Constellation Energy Generation (CEG) submitted a request for an amendment to Renewed Facility Operating License No. NPF-66 for the Byron Station (Byron), Unit 2 to adopt Technical Specifications Task Force (TSTF)-577, "Revised Frequencies for Steam Generator Tube Inspections." Reference 1 was approved by the Nuclear Regulatory Commission (NRC) in Reference 2. As noted in Reference 1, "CEG will submit SG Tube Inspection Reports meeting the revised TS 5.6.9 requirements within 30 days after implementation of the license amendment at Byron." Based on NRC approval (Reference 2) TSTF-577 was implemented at Byron Station on March 8, 2023, and the Byron Unit 2 SG Tube Inspection Report was submitted on April 6, 2023 (Reference 5).

Byron Unit 2 Technical Specification (TS) 5.6.9, "Steam Generator Tube Inspection Report," states "A report shall be submitted within 180 days after the initial entry into MODE 4 following completion of an inspection performed in accordance with the Specification 5.5.9, 'Steam Generator (SG) Program'." This enclosure provides the revised 180-day report with the revised Byron Unit 2 TS 5.6.9 reporting requirements in accordance with References 1 and 2. Each Byron Unit 2 TS 5.6.9 reporting requirement is listed below along with the associated information based on the inspection performed during the Byron Unit 2 Cycle 23 April 2022 refueling outage (B2R23), which was the last inspection of the Byron Unit 2 steam generators (SGs) (Reference 3). This report follows the template provided in Appendix G to the Electric Power Research Institute (EPRI) Steam Generator Management Program: Steam Generator Integrity Assessment Guidelines, Revision 5 (Reference 4),

which provides additional information beyond the Byron Unit 2 TS 5.6.9 reporting requirements.

E2 - 1 of 40

Enclosure 2

1. Design and operating parameters The SGs at Byron Unit 2 are original Westinghouse Model D5 SGs, which have thermally treated Alloy 600 tubing. Inspections of the SGs were last performed during B2R23. These inspections included eddy current testing of the SG tubing as well as primary and secondary side cleanings and visual inspections. Table 1 provides the Byron Unit 2 SG design and operating parameter information.

Table 1: Byron Unit 2 - Steam Generator Design and Operating Parameters SG Model / Tube Material / Westinghouse Model D5 / Alloy 600TT I 4 Number of SGs per Unit Number of tubes per SG / 4,570 I 0.75 in./ 0.043 in Nominal Tube Diameter/ tube thickness Support Plate Style I Material Quatrefoil (Broached) TSPs and U-bend AVBs /

stainless steel Last Inspection Date Spring 2022 during 82R23 EFPM Since Last Inspection 52.33 EFPM (4.36 EFPY) (from B2R20 to 82R23)

Total Cumulative SG EFPY 31.4 EFPY (as of 82R23)

Mode 4 Initial Entry 5/10/2022 from B2R23 Observed Primary-to-Secon dary No Observed Leakage Leak Rate Nominal Thot at Full Power 611 °F Operation Loose Parts Strainer The Model D5 design has a preheater section with multiple baffles through which the main feedwater travels. Foreign objects entering the SGs tend to collect on the lowest elevation baffle plate. In addition, each main feedwater pump has small diameter holes in an inlet strainer to prevent the introduction of foreiqn material into the pipinq leading to the SGs.

Degradation Mechanism A sub-population of 65 potentially high residual Sub-Population stress tubes has been identified from screen eddy current U-bend offset signals and are currently designated as a sub population potentially more susceptible to ODSCC in the B2R23 degradation assessment.

SG program guideline deviations None since last Inspection SG Schematic See Figure 1 E2 - 2 of 40

Enc losu re 2 Figure 1: Tube Suppo rt Arran geme nt for Byron Unit 2 Model D5 SGs AnU-vl bration

~==-- -C.... .--\-.I J---~ -bars 11H 11C 111H 10C a'9H 09C 0811 DBC D7H 07C 06C 05H 05C 04C i=eedw a1ar 03H Inlet 03C 02C 01H on::

TSH TSC TEH TEC Nozzle filanwa y Notes: Anti-V ibratio n Bars (AVB) are denote d as AV in the figure tt#-C - Cold Leg Tube Suppo rt Plate (quatr efoil) / Baffle (drilled hole) tt#-H - Hot Leg Tube Suppo rt Plate (quatr efoil) / Baffle (drilled hole)

TSH/T SC -Hot/C old Tubes heet (desig nates top of tubesh eet)

TEH/T EC - Hot/Co ld Tube End E2 - 3 of 40

Enclosure 2

2. The scope of the inspections performed on each SG (TS 5.6.9.a) and if applicable, a discussion of the reason for scope expansion The B2R23 outage was comprised of a 100% bobbin and 100% array probe full length examination of all in service tubes in all four SGs. These inspections may use a combination probe that contains a bobbin coil and array coils.

• Due to a low bend radius of tubes in Rows 1 and 2, these tubes were only inspected from tube end to the 11 th hot leg or cold leg tube support (11 H or 11 C).

Rotating pancake coil (RPC) probes (Plus-Point) were used for special interest testing and resolution of bobbin and array indications when necessary. These included:

• 100% Row 1 and Row 2 U-bend region from TSP 11 H to 11 C.

• 100% Dents/Dings >5.0 volts located in the Hot leg, Cold leg and U-bend.

There was no scope expansion required or performed during the B2R23 eddy current inspections.

In addition to the eddy current inspections, visual inspections were also performed on both the primary and secondary sides. Primary side visual inspections included the channel head bowl cladding and the divider plate. There were no previously installed tube plugs to inspect from the primary side. Secondary side visual inspections were performed at the top of the tubesheet for the detection of foreign objects, assessment of hard deposit buildup in the tube bundle interior kidney region, and for determining the effectiveness of the tubesheet cleaning performed in the four SGs.

3. The nondestructive examination techniques utilized for tubes with increased degradation susceptibility (TS 5.6.9.b).

Prior to B2R23, there were 65 tubes designated as having increased degradation susceptibility to ODSCC based on a screening performed by Framatome and EPRI which was correlated to residual stress. Although none of these tubes were found to have cracking a during the B2R23 inspection, 7 tubes believed to have the highest susceptibility were preventatively plugged during B2R23 (see Tables 8 and 9). Full length Array probe and Plus Point at Dents and Dings > 2V and any wear indications was performed on all 65 tubes.

4. The nondestructive examination technique utilized for each degradation mechanism found (TS 5.6.9.c.1 ).

All SG eddy current examination techniques used for detection (see Table 2 below) and sizing degradation (see Table 3 below) were qualified in accordance with Appendix H or I of the EPRI PWR SG Examination Guidelines Revision 8. Each examination technique was evaluated to be applicable to the tubing and the degradation mechanisms found in the Byron Station Unit 2 SGs during B2R23.

E2 - 4 of 40

Enclosure 2 Table 2 : NOE Detection Techniques Utilized Detection Detection Technique ETSS< 1l Degradation Location Probe Type Mechanism Existing Degradation Mechanisms Bobbin 96041.1 (Rev 6) (App. I) Wear AVB Supports Array 17908.1 /.4 (Rev 1) (App. I)

Bobbin 96042.1 (Rev. 4) (App. I) Wear FOB/ Baffle Pates Array 17908.1/.4 (Rev 1) (App. I) (Drilled Hole)

Bobbin 96004.1 (Rev 13) Wear Quatrefoil TSPs Array 11956.3/.4 (Rev 3) (App. I) (broach)

Bobbin 27091.2 (Rev 2) Wear due to Foreign Top of Tubesheet and Array 17901.1/.3 through 17906.1/.3 Objects Sludge Pile Tube (Rev 0) Support Plates Array 20400.1 (Rev 5) and Freespan Array 20402.1 (Rev 5)

Array 20403.1 (Rev 5)

Potential Degradation Mechanisms Array 20501.1 (Rev 4) -Axial Array 20500.1 (Rev 4) - Gire. PWSGG, Axial/Gire. Expansion Region to

+POINT 11524.1 (Rev 0) - Gire. (App. I) TTS-14.01" Array 20501.1 (Rev 4) -Axial PWSGG, Axial/Gire. Expansion Region to Array 20500.1 (Rev 4) - Gire. (BLG/OXP) TTS-14.01"

+POINT 96511.2 (Rev 16) -Axial/Gire. PWSGG, Axial/Gire. Row 1/Row 2 U-Bend Array 23513.1 (Rev 3) -Axial/Gire. Low Row U-bend Array OD: Top of Tubesheet 20402.1 (Rev 5) -Axial ODSGG/PWSGG Expansion Transition 20400.1 (Rev 5) - Gire. Axial/Gire. and ID: Pre-heater Baffle Plate 20501.1 (Rev 4) -Axial Expansion Transitions 20500.1 (Rev 4) - Gire. (TSP 02G/03G)

Bobbin 28413 (Rev 5) -Axial (App. I)

+POINT 28424 (Rev 4) -Axial (App. I)

+POINT 21410.1 (Rev6)-Girc. ODSGG, Axial/Gire. Sludge Pile Array 20402.1 (Rev 5) - Axial Array 20403.1 (Rev 5) -Axial Array 20400.1-Girc Bobbin 128413 (broach/freespan) Tube Support Plates, 128411 (drilled) FOB/Baffle Plates, Freespan, High Row U-

+POINT 128424 (drilled) ODSGG, Axial Bend 128425 (broach and freespan) (Rows 10 and higher)

Array 20402.1 Array 10413.2-Axial ODSGG, Axial Low Row U-bends, Rows 3-5 Bobbin 10013.1 (Dents) -Axial Dents/Dings <5v 24013.1 (Dings) - Axial

+POINT 22401.1 (Dents/Dings) -Axial ODSGG, Axial/Gire. Dents/Dings >5v 21410.1 (Dents/Dings) - Gire. Baffle Plate Dents 2-5v Dings below Baffle Plates 2-5v Bobbin 96005.2 Pitting, Volumetric Top of tubesheet, Array 24998.1 Indications Freespan Note: (1) ETSS - Examination Technique Specification Sheet E2 - 5 of 40

Enclosur e 2 Table 3 : NOE Sizing Techniques Utilized EPRI Detection ETSS Degradation Technique Location Applicability Probe Rev. Mechanism ETSS

+Point' Volumetric 21998.1 4 Foreign Object Wear Locations Wear Bobbin Wear at AVBs< 1>

96004.3 13 Structure

+Point' 96910.1 Wear at TSPs< 1> (Quatrefoil and Drilled Hole 11 Structure Baffle)

Note: (1) TSP - Tube Support Plate AVB -Anti-Vibration Bar

5. The location, orientation (if linear), measured size (if available), and voltage response for each indication. For tube wear at support structures less than 20 percent through-wall , only the total number of indications needs to be reported (TS 5.6.9.c.2).

Volumetric wear was the only degradation mechanism detected during the 82R23 inspection.

Anti-Vibration Bar (AVB) Wear Tube degradation was found during bobbin coil examination in the U-Bend region due to fretting of the AVB on the outer surface of the tube. A total of 1212 indications were reported. After 3 operating cycles eleven (11) tubes in the 4 SGs had indications of AVB wear meeting or exceeding the 40% TW plugging limit and were removed from service by mechanical tube plugging. The largest AVB wear indication found during B2R23 was measured at 50% through-wall (TW). The Table 4 below provides a summary of AVB wear degradation. Refer to Attachment A for detailed locations and sizing for all AVB wear indications.

Table 4: B2R23 AVB Wear Summary SG2A SG 28 SG 2C SG 20 Total

1. of Ind. # of Ind. # of Ind. # of Ind. # of Ind.

10-39% TW 263 427 314 197 1201

>= 40% TW 5 2 3 1 11 TOTAL 268 429 317 198 1212 Mechanical Wear at Tube Support Plates (TSPs) - Tube degradation attributed to wear in the quatrefoil (broached) TSPs and in the pre-heater TSPs, which are drilled support baffle plates, was identified. A total of 24 indications in 16 support plate structures were identified as wear during B2R23. Within this population, 14 pre-existing TSP wears were identified in the 28, 2C, and 20 SGs and 10 newly identified TSP wears were found in 4 tubes in 20 SG. The depth of the TSP wear ranged from 11 % TW to 32% TW. Table 5 below provides a summary of the tubes that contain indications of pre-heater or quatrefoil TSP wear as identified during B2R23.

E2 - 6 of 40

Enclosur e 2 Table 5: 82R23 Tube Support (Quatrefoil and Baffle Plate) Wear Summary Max Plus Row Wear 82R23 Total Wear SG Col Loe Depth Point Type 3/4TW Length Character 3/4TW Voltage 28 15 91 06C Baffle 11 11 0.62 0.18 Flat 07C-#1 Quatrefoil 21 23 1.26 0.44 Flat 2B 46 50 07C-#2 Quatrefoil 15 15 0.75 0.27 Tapered 2B 47 54 07C Quatrefoil 22 23 1.21 0.46 Tapered 2B 47 75 02C Baffle 12 12 0.3 0.21 Flat 2B 49 64 07C Quatrefoil 12 14 0.99 0.20 Flat 2B 49 73 07C Quatrefoil 15 15 0.64 0.26 Tapered 2C 48 63 07C Quatrefoil 25 29 1.01 0.51 Tapered 08C-#1 Quatrefoil 21 21 1.14 0.47 Tapered 20 48 51 08C-#2 Quatrefoil ( 1) 15 0.67 (1) Tapered 08C-#3 Quatrefoil ( 1) 11 0.41 (1) Tapered 05C Baffle 17 17 0.41 0.34 Tapered 20 48 63 07C Quatrefoil 19 23 1.13 0.41 Tapered 08C Quatrefoil 32 32 1.14 0.96 Tapered 08C-#1 Quatrefoil 21 21 0.98 0.47 Tapered 20 49 62 08C-#2 Quatrefoil ( 1) 16 0.87 ( 1) Tapered 07C-#1 Quatrefoil 18 19 1.03 0.37 Tapered 20 49 63 07C-#2 Quatrefoil 26 26 1.03 0.66 Tapered 07C-#3 Quatrefoil 19 25 1.03 0.42 Tapered 07C-#1 Quatrefoil 22 27 1.11 0.49 Tapered 07C-#2 Quatrefoil ( 1) 13 0.72 ( 1) Tapered 20 49 64 08C-#1 Quatrefoil 16 16 0.84 0.32 Tapered 08C-#2 Quatrefoil (1) 13 0.83 ( 1) Flat 20 49 70 05C Baffle 15 15 0.49 0.30 Tapered Notes:

(1) Five (5) additional quatrefoil TSP wear indications were identified during depth profiling and were located at the same elevation as an existing indication but at another quatrefoil land. The Plus Point voltage for these< 20% TW indications was not provided.

Foreign Object Wear - A total of 34 indications of FO wear were identified during B2R23. Twenty-eight (28) of the indications were historical and the remaining six (6) were newly reported during B2R23. The indications ranged from 9% TW to 37% TW. The historical FO wear shows no significant change in eddy current signal response. All FO associated with the historical wear indications were removed in a prior outage.

All six (6) tubes with new wear had an FO still present, i.e., an associated PLP signal from eddy current. While the depths of the indications did not meet or exceed the 40% TW tube plugging limit, these tubes were preventatively plugged due to the FO that caused the wear is still present and could cause continued tube wear. The table below lists the data record for the eddy current signals corresponding to foreign object wear indications detected during B2R23.

E2 - 7 of 40

Enclos ure 2 Table 6: Byron B2R23 Foreign Object Wear Indication Summary and Sizing Results Plus SG Row TSP Depth Point Axial Circ New/ FO Col lnch1 Loe. (%TW) Voltage Length Extent Legacy Present (inch) (degrees) 2A 5 88 06C 0.49 28 0.27 0.25 66 New Yes 2A 8 76 07H -0.95 20 0.19 0.14 37 Legacy No 2A 20 65 08H -1.56 34 0.41 0.21 62 New Yes 2A 21 66 07H 41.88 22 0.17 0.19 52 New Yes 2A 28 56 07H -0.73 13 0.11 0.16 32 Legacy No 2A 30 50 03H -0.69 23 0.24 0.11 29 Legacy No 2A 39 50 02C 2.33 14 0.11 0.11 31 Legacy No Yes (in 2A 41 53 07H -0.79 19 0.14 29 New Adj.

0.17 Tube) 2A 45 67 02C 1.2 18 0.16 0.2 62 Legacy No 2A 45 67 02C 3.02 21 0.19 0.11 35 Legacy No 2A 47 67 02C 0.42 25 0.18 0.34 62 Legacy No 2B 1 54 02C -0.28 26 0.28 0.29 25 Legacy No 2B 14 4 05H 0.89 9 0.07 0.27 65 Legacy No 2B 17 48 05H 34.71 25 0.28 0.26 54 Legacy No 2B 27 74 05H -0.92 16 0.15 0.27 63 Legacy No 2B 29 25 01H 0.62 9 0.08 0.27 63 Legacy No 2B 29 26 01H 0.67 18 0.17 0.3 60 Legacy No 2B 35 15 07H -0.97 14 0.12 0.19 46 Legacy No 2B 37 74 07H -1.05 19 0.19 0.19 46 Legacy No 2B 38 35 05H -0.88 11 0.09 0.11 46 Legacy No 2B 38 35 05H -0.49 25 0.28 0.13 52 Legacy No 2B 38 66 02C 1.44 21 0.21 0.51 43 Legacy No 2B 39 66 02C 0.82 10 0.09 0.21 31 Legacy No 2C 6 48 05H -0.85 20 0.18 0.27 66 Legacy No 2C 13 58 07H -0.83 26 0.26 0.27 71 New Yes 2C 16 18 01H 0.59 22 0.19 0.16 28 Legacy No 2C 17 18 01H 0.68 15 0.12 0.16 26 Legacy No 2C 48 35 02C 0.5 31 0.35 0.3 71 Legacy No 2D 6 44 08H -0.54 34 0.44 0.19 31 Legacy No 2D 9 76 07H -0.83 18 0.16 0.26 58 Legacy No 2D 24 47 05H -0.78 30 0.35 0.25 58 Legacy No 2D 24 65 02C 1.01 34 0.33 0.36 69 Legacy No 2D 25 65 02C 1.45 15 0.08 0.2 58 Legacy No 2D 38 43 07H -0.98 37 0.37 0.19 62 New Yes E2 - 8 of 40

Enclosure 2

6. A description of the condition monitoring assessment and results, including the margin to the tube integrity performance criteria and comparison with the margin predicted to exist at the inspection by the previous forward-looking tube integrity assessment (TS 5.6.9.c.3). Discuss any degradation that was not bounded by the prior operational assessment in terms of projected maximum flaw dimensions, minimum burst strength, and/or accident induced leak rate. Provide details of any in situ pressure test.

A condition monitoring assessment was performed for each inservice degradation mechanism found during the B2R23 SG inspection. The condition monitoring assessment was performed in accordance with TS 5.5.9.a and NEI 97-06 Rev. 3 using the EPRI Steam Generator Integrity Assessment Guidelines, Revision 4. For each identified degradation mechanism, the as-found condition was compared to the appropriate performance criteria for tube structural integrity, accident induced leakage, and operational leakage as defined in TS 5.5.9.b. For each degradation mechanism a tube structural limit was determined to ensure that SG tube integrity would be maintained over the full range of normal operating conditions, all anticipated transients in the design specifications, and design basis accidents. This includes retaining a safety factor of 3.0 against burst under normal steady state full power operation primary to secondary pressure differential and a safety factor of 1.4 against burst under the limiting design basis accident pressure differential. The structural limits for wear related degradation were performed in accordance with the EPRI Steam Generator Integrity Assessment Guidelines and the EPRI Steam Generator Degradation Specific Management Flaw Handbook, Revision 2 (Flaw Handbook).

The as-found condition of each tubing degradation mechanism found during the B2R23 outage was shown to meet the appropriate limiting structural integrity performance parameter with a probability of 0.95 at 50% confidence, including consideration of relevant uncertainties thus satisfying the condition monitoring requirements. The NOE measured flaw depths are compared to the structural integrity condition monitoring (CM) limits, which account for tube material strength, burst relation, and NOE measurement uncertainties with a 0.95 probability at 50% confidence. Therefore, the NOE measured flaw sizes are directly compared to the CM limit. No indications met the requirements for proof or leakage testing; therefore, no In Situ Pressure tests were performed during B2R23. In addition, no tube pulls were performed during B2R23.

The sections below provide a summary of the condition monitoring assessment for each degradation mechanism found during B2R23.

AVB Wear- The two largest AVB wear indications found during the B2R23 inspection were 49% TW in SG 2A (R42-C56) and 50% TW in SG B (R42-C44) as measured by the EPRI Appendix H qualified technique 96004.3, Rev. 13. This is below the AVB wear CM limit of 64.3% TW.

Pre-Heater Baffle/TSP Wear- All TSP wear located at quatrefoil TSPs or drill hole baffle plate supports and independent if tapered or flat was depth sized using the +Point Examination Technique Specification Sheet (ETSS) 96910.1, Rev. 11 technique.

None of the TSP/drilled hole baffle plate wear indications exceeded the CM limits. The maximum quatrefoil TSP wear indication reported during B2R23 was in SG 2D at R48-C63 TSP 08C measuring an NOE depth of 32% TW. This bounding quatrefoil wear is below the CM limit for quatrefoil TSP wear of 52.7% TW. In addition, the maximum baffle plate wear indication reported during B2R23 was in SG 2D at R48-C63 TSP 05C measuring an NOE depth of 17% TW. The bounding quatrefoil wear (32% TW) is below the CM limit for quatrefoil TSP wear of 52.7% TW and bounding baffle plate wear (17% TW) is less than the CM limit for E2 - 9 of 40

Enclosure 2 drilled hole baffle plate wear of 54.9% TW. Therefore, condition monitoring for structural and leakage integrity has been satisfied for both quatrefoil TSP wear and baffle plate wear.

Foreign Object Wear - All foreign object wear was depth sized using the +Point Examination Technique Specification Sheet (ETSS) 21998.1, Rev. 4 technique for small diameter indications. The deepest foreign object wear indication found during the B2R23 inspection was 37% TW with axial extent of 0.19 inch and a circumferential extent of 0.22 inch (Tube R38-C43 in SG 2D). The CM limit for wear flaws with limited circumferential extent (up to 135 degrees/

0.88 inch) and an axial extent of up to 0.25 inches is 64.1 % thus the CM performance criteria was satisfied. Note: Other shallower depth wear indications were longer and/or wider.

Nevertheless, all historical FO wear and newly identified FO wear falls within the bounds of the CM limit of 53.0% TW defined by a 0.55 inch axial extent and 135 degree circumferential wear indication.

A summary of the CM results from B2R23 as compared to the predictions from the most recent prior inspection (B2R20) is provided in Table 7.

Table 7: Comparison of Prior OA Projections to As-Found Results Parameter B2R20 OA Projection B2R23 As-Found Result (NOE Depth)

Maximum Depth for Anti-Vibration Bar (AVB) Wear 58.3%TW 50%TW Maximum Depth for Tube 49.6% TW Quatrefoil Support Wear 32%TW Quatrefoil 32.0% TW Baffle Plate 11 %TW Baffle Plate No actual change in depth Growth of Repeat Foreign expected since foreign objects No change in measured depth Object Wear Indications are no longer present Maximum Depth for New Limiting flaw won't challenge 37% TW as-found met Foreign Object Wear structural or leakage integrity CM limit (53% TW) analytically Because volumetric wear indications will leak and burst at essentially the same pressure, accident-induced leakage integrity is also demonstrated. Operational leakage integrity was demonstrated by the absence of any detectable primary-to-second ary leakage during the operating interval prior to B2R23. Because tube integrity was demonstrated analytically, in-situ pressure testing was not required nor performed during B2R23. There were no tube pulls planned or performed during B2R23.

E2 - 10 of 40

Enclosure 2

7. The number of tubes plugged during the inspection outage (TS 5.6.9.c.4). Also, provide the tube location and reason for plugging.

Table 8 provides the numbers of tubes plugged for each degradation mechanism detected and for tubes plugged preventatively. Table 9 provides the tube location and reason for plugging.

Table 8: B2R23 Tube Plugging by Degradation Mechanism Degradation Mechanism 2ASG 2BSG 2CSG 2DSG Total Anti-Vibration Bar (AVB) Wear

> 40% TW / Preventative (< 40% TW) 5/4 2/3 3/0 1/ 1 11 / 8 Quatrefoil TSP Wear .:::_40% TW /

0/0 0/4 0 /1 0/5 0 /10 Preventative (<40% TW)

Foreign Object Wear .:::_40% TW /

0/4 0/0 0/1 0I 1 0/6 Preventative (<40% TW)

Preventative - PLP 2 0 0 0 2 Preventative - High stress Tube 1 2 1 3 7 Total Pluaaed durinq B2R23 16 11 6 11 44 Table 9: Byron B2R23 New Plugging by Location, Degradation Mechanism and Reason Degradation Plugging Reason SG Row Col Mechanism 2A 5 88 Foreign Object Wear Preventative <40% TW 2A 5 89 PLP Preventative 2A 20 65 Foreign Object Wear Preventative <40% TW 2A 21 66 Foreign Object Wear Preventative <40% TW 2A 21 71 High Stress Tube Preventative 2A 29 10 AVB Wear Tech. Spec. >40%TW 2A 38 63 AVB Wear Preventative <40% TW 2A 39 94 AVB Wear Tech. Spec. >40% TW 2A 40 91 AVB Wear Tech. Spec . .:::_40%TW 2A 41 53 Foreign Object Wear Preventative <40% TW 2A 41 54 PLP Preventative 2A 41 85 AVB Wear Preventative <40% TW 2A 42 25 AVB Wear Tech. Spec. >40% TW 2A 42 56 AVB Wear Tech. Spec . .:::_40%TW 2A 44 88 AVB Wear Preventative <40% TW 2A 46 64 AVB Wear Preventative <40% TW 2B 11 29 High Stress Tube Preventative 2B 12 6 High Stress Tube Preventative 2B 31 12 AVB Wear Tech. Spec. >40%TW 2B 33 14 AVB Wear Preventative <40% TW 2B 36 16 AVB Wear Preventative <40% TW 2B 40 41 AVB Wear Preventative <40% TW E2 - 11 of 40

Enclosure 2 2B 42 44 AVB Wear Tech. Spec. ~40%TW 2B 46 50 TSP Wear Preventative <40% TW 2B 47 54 TSP Wear Preventative <40% TW 2B 49 64 TSP Wear Preventative <40% TW 2B 49 73 TSP Wear Preventative <40% TW 2C 13 58 Foreign Object Wear Preventative <40% TW 2C 41 63 AVB Wear Tech. Spec. ~40%TW 2C 42 89 AVB Wear Tech. Spec. >40%TW 2C 42 93 AVB Wear Tech. Spec. >40%TW 2C 43 68 High Stress Tube Preventative 2C 48 63 TSP Wear Preventative <40% TW 20 15 54 High Stress Tube Preventative 20 20 88 High Stress Tube Preventative 20 21 67 High Stress Tube Preventative 20 38 43 Foreign Object Wear Preventative <40% TW 20 39 80 AVB Wear Preventative <40% TW 20 41 60 AVB Wear Tech. Spec. >40%TW 20 48 51 TSP Wear Preventative <40% TW 20 48 63 TSP Wear Preventative <40% TW 20 49 62 TSP Wear Preventative <40% TW 20 49 63 TSP Wear Preventative <40% TW 20 49 64 TSP Wear Preventative <40% TW

8. An analysis summary of the tube integrity conditions predicted to exist at the next scheduled inspection (the forward-looking tube integrity assessment) relative to the applicable performance criteria, including the analysis methodology, inputs, and results (TS 5.6.9.d). The effective full power months of operation permitted for the current operational assessment.

Anti-Vibration Bar (AVB) Wear Operational Assessment (OA)

The OA for AVB wear will use the worst-case degraded tube simplified analysis procedure for plugging on NOE sizing where the NOE uncertainties are combined using a mixed arithmetic/simplified statistical strategy. This method combines the largest flaw left in service as measured by NOE techniques and growth allowance is applied to determine the predicted flaw depth at the end of the next inspection interval. The predicted NOE flaw depth is compared to the condition monitoring limit that includes uncertainties for NOE measurement, material property, and burst relation that are combined through Monte Carlo simulations.

The largest AVB wear left in service during B2R23 was measured at 39% TW (ETSS 96004.3) and is used as the BOC flaw size for OA and the largest 95 th percentile growth rate found in any of the SGs over the last three inspections is 2.28% TW/EFPY which was from Cycle 18 and the growth period which includes the 1.077 MUR uprate AVB wear growth rate factor.

The OA methodology must address flaws that may be undetected by the inspection technique however the 95 th percentile undetected flaw is only 18.2%TW. Since the 18.2% TW flaw is bounded by the largest flaw returned to service (39% TW) and 100% inspections were performed in B2R23 and planned future inspection, the OA for existing flaws is bounding. A separate OA for undetected flaws is not necessary.

E2 - 12 of 40

Enclosure 2 A 3-cycle and a 4-cycle OA prediction was performed to provide flexibility in outage planning. The largest flaw size projected at B2R26 (3 cycles) and B2R27 (4-cycles) is determined as follows:

OA for AVB Wear 3-cycle OA 4-cvcle OA Maximum BOC NOE Depth, %TW 39.0o/oTW 39.0o/oTW 99th Percentile Growth per EFPY 3.5%TW/EFPY 3.5% TW/EFPY EFPY per Cycle 1.46 EFPY 1.46 EFPY Number of Cycles 3 4 Predicted NOE Depth 54.3%TW 59.4%TW Condition Monitorinq LimitC 1l 63.6%TW 63.6%TW Notes:

(1) The CM limit includes NOE measurement, material property, and burst relation uncertainties at 0.95 probability and 50% confidence level.

Mechanical Wear at Quatrefoil Tube Supports OA The OA for Quatrefoil TSP wear will use the worst-case degraded tube simplified analysis procedure for plugging on NOE sizing where the NOE uncertainties are combined using a mixed arithmetic/simplified statistical strategy. This method combines the largest flaw left in service as measured by NOE techniques and growth allowance is applied to determine the predicted flaw depth at the end of the next inspection interval. The predicted NOE flaw depth is compared to the condition monitoring limit that includes uncertainties for NOE measurement, material property, and burst relation that are combined through Monte Carlo simulations.

For OA purposes, all quatrefoil TSP wear flaws are conservatively assumed to be flat wear and conservatively assumes a flat wear profile of the maximum flaw depth applied over the entire 1.12 inch TSP thickness.

During the B2R23 inspection a newly reported tapered TSP wear was observed at a maximum depth 32% TW (20 R48C63 at TSP 08C). Historical data review of showed a small precursor signal at the prior inspection. This tube also contained to other support wear indications at 19%TW at TSP 07C and 17%TW at TSP 05C, both had no or little growth from historical reports.

Due to the limited number of growth data points and limited time to complete a detailed analysis for this apparent higher than expected growth to support inspection closeout, all 10 tubes found with quatrefoil TSP wear during B2R23 were preventively plugged to preserve a 4-cycle inspection interval.

The maximum growth rate observed for quatrefoil TSP wear over the last three inspections dating to B2R18 (2014) was 5.05%TW/EFPY. This growth rate was obtained during the B2R23 inspection and was associated with the newly reported 32% TW flaw. This growth was after operation at MUR uprated conditions, therefore no uprate growth adjustments are necessary. The growth rate used for this OA will be rounded up to 5.1 %TW/EFPY.

The 95 th percentile undetected flaw left in service is 17.4%TW. Since all TSP wear indications were removed from service during B2R23, the wear depth for an undetected (i.e., BOC flaw size) will conservatively be assumed to be 18% TW.

A 3-cycle and a 4-cycle OA prediction was performed to provide flexibility in outage planning. The largest 3-cycle flaw size projected at B2R26 (3-cycles) and B2R27 (4-cycles) is determined as follows:

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Enclosure 2 OA for Quatrefoil TSP Wear 3-cycle OA 4-cycle OA 95 th Percentile from POD Curve, %TW (BOC 18%TW 18%TW depth) 95th Percentile Growth per EFPY 5.1 %TW/EFPY 5.1 %TW/EFPY EFPY per Cycle 1.46 EFPY 1.46 EFPY Number of Cycles 3 4 Predicted NOE Depth 40.3%TW 47.8%TW Condition MonitorinQ Limit( 1 l 51.8%TW 51.8%TW Notes:

(1) The CM limit includes NOE measurement, material property, and burst relation uncertainties at 0.95 probability and 50% confidence level.

Mechanical Wear at Drilled Hole Baffle Plate Supports OA The OA for drilled hole baffle plate wear will use the worst-case degraded tube simplified analysis procedure for plugging on NOE sizing where the NOE uncertainties are combined using a mixed arithmetic/simplified statistical strategy. This method combines the largest flaw left in service as measured by NOE techniques and growth allowance is applied to determine the predicted flaw depth at the end of the next inspection interval. The predicted NOE flaw depth is compared to the condition monitoring limit that includes uncertainties for NOE measurement, material property, and burst relation that are combined through Monte Carlo simulations.

Similar to the quatrefoil TSP OA methodology described above, the OA for drilled hole baffle supports will conservatively assume flat wear instead of tapered wear.

The largest drill hole baffle plate tube support wear left in service during B2R23 was measured at 17% TW by ETSS 96910.1. There have been very few drilled hole baffle plate wear indications at Byron-2, therefore, the maximum growth rate for drill hole baffle plate wear observed over history will be used. The largest flaw of either type that is left in service will be used as the BOC depth.

The maximum depth will be applied uniformly over the entire thickness of the baffle plate will be applied (0.75 inch). The largest growth rate of wear at drilled hole baffle plates at Byron-2 since B2R13 (2007) is 2.48% TW/EFPY. As a conservative measure, the quatrefoil TSP wear growth rate of 5.1 %TW/EFPY was used in OA.

For worst case simplified OA methods when 100% inspections have been performed and planned in the future, the larger of the return to service flaw depth or the 95 th percentile POD depth is used as the BOC flaw depth assumption. In this case, the largest returned to service flaw depth of 17% TW was used as the BOC flaw size.

A 3-cycle and a 4-cycle OA prediction was performed to provide flexibility in outage planning. The largest 3-cycle flaw size projected at B2R26 (3 cycles) and B2R27 (4-cycles) is determined as follows:

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Enclosure 2 OA for Drilled Hole Baffle Wear 3-cycle OA 4-cycle OA Maximum BOC NOE Depth, % TW 17%TW 17%TW 95th Percentile Growth per EFPY 5.1 % TW/EFPY 5.1%TW/EFPY EFPY per Cycle 1.46 EFPY 1.46 EFPY Number of Cycles 3 4 Predicted NOE Depth 39.3%TW 46.8%TW Condition MonitorinQ Limit< 1l 54.1%TW 54.1%TW Notes:

(1) The CM limit includes NOE measurement, material property, and burst relation uncertainties at 0.95 probability and 50% confidence level.

Mechanical Wear due to Foreign Objects OA All tubes containing newly reported FO wear during B2R23 were preventively plugged. The only FO wear indications remaining inservice have been in service for multiple cycles and with no evidence of a FO. These indications have not changed or grown since their initial detection.

Therefore, continued operation until the next planned SG inspection during B2R26 or B2R27 is acceptable since there is no wear mechanism for continued growth. All the existing FO wear indication wear depths are less than the condition monitoring limit and therefore meets the OA performance criteria for existing volumetric wear with the upper tube bundle.

For new FO wear associated with migration of objects that caused the existing wear found in B2R23, an OA is performed based upon a volumetric work rate that caused a known existing or new wear FO wear in the upper bundle. The 3-cycle volume work rate model results in a predicted B2R26 flaw size of 45.2% TW, which is satisfies the condition monitoring limit of 68.3% TW that includes NOE, material property and burst relation uncertainties at 95/50. The 4-cycle OA results in a predicted B2R27 flaw size of 54.8% TW, also satisfying the axial flaw condition monitoring limit 68.3% TW. Legacy Foreign objects which have not caused wear and benign objects left in the SGs were also evaluated. SG operation for current and legacy foreign objects remaining in the SGs satisfies the condition monitoring limit at the end of a 4-cycle inspection interval until B2R27.

Based upon the above evaluations, it is concluded that OA performance criteria is satisfied with margin for all existing wear degradation mechanisms for inspection intervals of both 3-cycles and 4-cycles. These results are summarized in Table 10.

Table 10: Byron-2 Deterministic Operational Assessment Summary for Existing Wear Degradation Mechanisms 3-Cycle 4-Cycle Condition 3-Cycle 4-Cycle Degradation Projection, Projection, Monitoring Margin to Margin to Mechanism 3/4TW 3/4TW Limit, 3/4TW Limit, 3/4TW Limit, 3/4TW AVB Wear 54.3 59.4 63.6 9.3 4.2 Quatrefoil TSP Wear 40.3 47.8 51.8 11.5 4 Drilled Hole Baffle Wear 39.3 46.8 54.1 14.8 7.3 Foreiqn Object Wear< 1l 37( 1) 37( 1) 53< 1) - -

Foreign Object Wear< 2l 45.2 54.8 68.3 23.1 13.5 Notes: (1) Legacy-No known foreign objects present, therefore, there is no mechanism to propagate the flaw. Values listed are the largest flaws left in-service.

(2) New -Affected tube(s) in 82R23 are plugged. Values listed assume object migrates to an in-service tube.

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Enclosure 2 Stress Corrosion Cracking (Potential Degradation) OA Byron-2 has not experienced any form of stress corrosion cracking (SCC) other than at the tube ends but sec is characterized as a potential degradation mechanism based on other A600TT plant experience. Site-specific fully probabilistic OA projections were performed for three common stress corrosion cracking mechanisms. These OA projections demonstrated that the SG performance criteria will be maintained over the next 3-cycle and 4-cycle inspection intervals. Table 11 provides a summary of the OA results for the SCC mechanism evaluated using fully probabilistic methods with their margin to the performance criterion.

Table 11: Byron-2 Fully Probabilistic Operational Assessment Summary for Potential sec Degradation Mechanisms Burst SLB Leak SLB OA Probability Burst Pressure Rate Degradation Probability Leak Interval, of Burst, Pressure, Margin to Margin to Mechanism of Leak,% Rate, cycles  % psi Criterion, Criterion, gpm psi gpm Circ ODSCC 3 0.663 0.936 5891 0 1691 0.5 at Exp. Trans. 4 2.3 2.762 5246 0.135 1046 0.365 Axial ODSCC 3 0.352 0.069 5825 0 1625 0.5 at Exp. Trans. 4 0.733 0.167 5336 0 1136 0.5 Axial ODSCC 3 0.809 0.655 5525 0 1325 0.5 at TSPs 4 2.006 1.773 4845 0 645 0.5 Performance Criterion ~5% ~5%  ::C:4200 ~0.5

9. The number and percentage of tubes plugged to date, and the effective plugging percentage in each SG (TS 5.6.9.e).

Table 12 shows the number of tubes plugged before and after the B2R23 outage and the percentage of tubes currently plugged (total and effective). No sleeves have been installed in Byron Unit 2.

Table 12: Byron-2 Tube Plugging Through B2R23 SG2A SG 28 SG 2C SG 2D Total No. Tubes Plugged prior to B2R23 159 142 166 42 509 No. Tubes Plugged during B2R23 16 11 6 11 44 Total No. Tubes Plugged through B2R23 175 153 172 53 553 Percent (Actual and Effective) Tubes 3.83% 3.35% 3.76% 1.16% 3.03%

Plugged Allowable Percent Tubes Plugged 10% 10% 10% 10% 10%

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Enclosure 2

10. The results of any SG secondary-side inspection (TS 5.6.9.f). The number, type, and location (if available) of loose parts that could damage tubes removed or left in service in each SG.

Secondary side foreign object search and retrieval (FOSAR) inspections were performed in all four SGs after sludge lancing. This included visual examination of tube bundle periphery tubes from the hot leg and cold leg annulus and center no tube lane. As listed in Table 13, a total of 11 foreign objects were removed from the top of the tubesheet region and one piece of scale was removed from the 8th tube support and 11 objects remain on the secondary side among the four SGs. The foreign objects remaining are small pieces of foil, bristles, scale and sludge rocks, which are located at the top of the tubesheet on either the HL or CL side. One piece of legacy weld slag also remains wedged in between tubes. It has been present since 2004 and has not moved or caused any tube wear. The limiting foreign object in terms of dimensions and potential to cause foreign object wear was a rod found in the annulus region measuring ~5 inch long and 0.06 inch in diameter located at the cold leg tubesheet in SG 2A at tube row 49 column 76/77. However, no tube wear in that area was detected. The remaining objects removed were not considered capable of causing significant tube wear.

Any foreign objects not able to be retrieved were characterized and an analysis performed to demonstrate acceptability of continued operation without exceeding the performance criteria. A limited top of tubesheet in-bundle visual inspection was also performed in each SG for the purpose of assessing and trending the level of hardened deposit buildup in the kidney region. The tube integrity assessment of the foreign objects remaining in the SGs also supports the conclusion as no adverse effects on tube integrity are projected within 4 cycles of operation.

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Enclosur e 2 Table 13: Byron 82R23 Foreign Objects Detected by Visual Inspections SG I Foreign Retrieval Inspection New/ Dimensions, Priority Object Leg Row-Col Fixity Comment FOID Status Elevation Legacy inch Description 2A/001 Active 3 Slag HL TTS, Annulus R28/29-C105 Legacy 0.75 Historic, No X 0.33 X 0.75 Wedged change 2A/002 Retrieved 1 Rod CL TTS, Annulus R49-C76/77 New 5.0 X 0.06 Loose ---

Soft metallic 2A/003 Active 3 Blue Foil CL TTS, Annulus C69/70 New 0.03 foil. Also found X 0.03 X 0.15 Loose on 2B Grit Tank Screen 2A/004 Active 3 Scale CL TTS, Annulus R48/49 New 0.5 X 0.06 Wedged ---

2A/005 Active 3 Wire Bristle TL TTS, TL R 1/2-C79/80 New 0.15 X 0.06 Loose ---

2A/006 Active 3 Wire Bristle CL TSP 02C R22/23-C94 New 0.2 Lost during X 0.01 ---

retrieval 2A/007 Active 3 Wire Bristle CL TSP 02C R21/22-C94 New 0.2 Non-metallic by X 0.01 Loose magnet 2A/008 Retrieved 3 Wire Bristle CL TTS R11-C57 New 0.4 X 0.03 Loose PLP from ECT 2A/009 Retrieved 3 Tape R19/20- ---

CL TTS New 0.3 X 0.3 X 0.3 Loose C56/57 2A/010 Sludge R14/15- ---

Retrieved 3 CL TTS New 0.31 X 0.31 X 0.31 Loose Rock C56/57 2A/011 Retrieved Machine 3 CL TTS R11/12-C57/58 New 0.29 X 0.29 X 0.29 Loose ---

Remnant 2B/001 Retrieved 3 Wire Bristle CL TTS, Annulus R40/41-C96/97 New 0.5 X 0.06 X 0.06 --- ---

2B/002 Retrieved 3 Scale HL TTS, Annulus R7/8-C113/114 New 0.31 x0.13x0.13 --- ---

2B/100 Retrieved 3 Scale HL TSP 08 R8/9-C39/40 New 0.75 X 0.2 X 0.02 --- ---

2D/001 Active 3 Scale HL TTS, Annulus R43/44-C22/23 New ---

0.75 X 0.05 X 0.1 ---

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Enclosure 2 Table 13: Byron B2R23 Foreign Objects Detected by Visual Inspections Foreign SG I Retrieval Inspection New/ Dimensions, Priority Object Leg Row-Col Fixity Comment FOID Status Elevation Legacy inch Description 2D/002 Active 3 Scale HL FOB Scale broken R4/5-C96/97 New 1 X 0.02 X 0.13 --- up 2D/003 Retrieved 3 Wire Bristle CL TSP 02C R8/9-C60/61 New 0.5 X 0.03 --- ---

2D/004 Active 3 Wire Bristle CL TSP 02C R3/4-C60/61 New 0.25 X 0.03 --- Fixed in crevice 2D/005 Active 3 Scale CL TSP 02C R30/31-C25/26 New 0.4 X 0.03 X 0.03 --- ---

2D/006 Retrieved 3 Wire Bristle CL TSP 02C R40/41-C54/53 New 0.5 X 0.01 --- Fixed in crevice Copper 2D/007 Retrieved 3 CL TSP 02C R41 /42-C22/23 New 0.7 X 0.01 --- ---

Wire 2D/008 Active 3 Wire Bristle CL TSP 02C R31/-C104/ New 0.75 X 0.01 --- Fixed in crevice 2D/009 Retrieved 3 Wire Bristle CL TSP 02C R5/6-C62/63 New 0.5 X 0.01 --- ---

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Enclosure 2 Waterbox/ Pre-Heater Inspections A visual inspection of the 2A, 2C, and 20 SG waterbox and cap plate regions were performed during B2R23. It was observed that the waterbox cap plate vent holes are rounded indicating minor erosion in both SGs, however, the condition is similar to previous inspections. The rounding of the cap plate vent holes is judged to pose no operational or structural concerns. The function of the cap plate vent holes is to provide venting of air during the filling of a SG. No other anomalies were identified in SG's 2A and 20. During a prior refueling outage at Byron Unit 2 (B2R20), a visual inspection of the preheater region of SG 2C found a loose part (backing bar) that was subsequently determined to have been generated from the steam generator's waterbox where the feedwater enters the steam generator. The waterbox of SG 2C was inspected during B2R23, all the remaining backing bars were found to be present and intact.

A visual inspection of the 2A and 20 SG preheater regions where the feedwater enters the SG were performed during B2R23. All four (4) fit-up blocks under TSP 03C were found intact in the 2A and 20 SGs inspected. The waterbox vertical rib plates and target plate in both SGs inspected were found to be in acceptable condition with no indication of degradation, erosion or other anomalies.

Steam Drum Inspections Inspection results for the SG 2A and SG 2B primary moisture separators in the steam drum still show signs Flow Accelerated Corrosion (FAC)/erosion wear and that it is, in general, progressing slowly with a 95th percentile upper bound wear rate of 0.020 in. /cycle. The minimum component thickness on SG 2A was on a riser barrel, which had an ultrasonic thickness measurement of 0.093 inches compared to the nominal component thickness of 0.25 inches. The minimum component thickness on SG 2B was on a tangential nozzle, which had an ultrasonic thickness measurement of 0.092 inches compared to the nominal component thickness of 0.25 inches. No repairs were required in B2R23, and it was concluded that operation for at least 2 and up to 4 cycles until repair and/or the next scheduled inspection is justified with no adverse consequences for the moisture separators in all 4 SGs.

11. The scope, method, and results of secondary-side cleaning performed in each SG Prior to the secondary side FOSAR inspections, sludge, scale, foreign objects, and other deposit accumulations at the top of the tubesheet were removed as part of the top of tubesheet high pressure water lancing process. The weight of deposits removed from each SG by this cleaning process is provided in Table 14. Secondary side deposits that may affect tube integrity have been managed by periodic sludge lancing, one "soft" chemical cleaning (ASCA) in 2017 and improving deposit removal efficiency through the use of a polyacrylic acid dispersant (PAA). These actions, combined with a lower feedwater iron concentration achieved through the combination of high pH and amines, have maintained the iron deposit inventory low and broach blockage at a low level such that SG water levels and steam pressure have been relatively steady for the past 2 years (4/21 to 4/23).

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Enclosure 2 Table 14: B2R23 and Prior Outage Sludge Lance Deposit Removal Results SG 2A SG 28 SG 2C SG 2D Total Outage Date (lbs) (lbs) (lbs) (lbs) (lbs)

B2R16 9/26/2011 24.5 28.0 25.5 34.0 112.0 B2R17 4/8/2013 Sludge Lancing Not Performed B2R18 9/29/2014 14.0 23.50 14.5 21.5 73.5 B2R19 4/16/2016 Sludge Lancing Not Performed B2R20 10/2/2017 733.0 635.0 653.0 817.0 2838.0 (ASCA)

B2R20 10/2/2017 73.5 81.5 68.0 71.5 294.5 B2R21 4/8/2019 Sludge Lancing Not Performed B2R22 10/5/2020 Sludge Lancing Not Performed B2R23 4/18/2022 13.0 19.5 30.0 15.5 78.0

12. The results of primary side component visual inspections performed in each SG Visual Inspection of Installed Tube Plugs and Tube-to-Tubesheet Welds All previously installed tube plugs (1018) were visually inspected for signs of degradation and leakage. The tube-to-tubesheet welds were visually inspected during eddy current. No degradation or anomalies were found.

SG Channel Head Bowl Visual Inspections Each SG hot and cold leg primary channel head was visually examined in accordance with the recommendations of Westinghouse NSAL 12-01 and NRC IN 2013-20 for evidence of breaches in the cladding or cracking in the divider to channel head weld and for evidence of wastage of the carbon steel channel head. No evidence of cladding breaches, wastage or corrosion in the channel head was identified. Also, no cracking in the divider to channel head weld was identified.

13. Byron Unit 2 has the following plant specific reporting requirements:

For Unit 2, the operational primary to secondary leakage rate observed (greater than three gallons per day) in each steam generator (if it is not practical to assign the leakage to an individual steam generator, the entire primary to secondary leakage should be conservatively assumed to be from one steam generator) during the cycle preceding the inspection which is the subject of the report (TS 5.6.9.g); and There was no confirmed operational primary to secondary leakage rate exceeding 3 gallons per day in the operating period since the last SG inspection.

For Unit 2, the calculated accident induced leakage rate from the portion of the tubes below 14.01 inches from the top of the tubesheet for the most limiting accident in the most limiting SG. In addition, if the calculated accident induced leakage rate from the most limiting accident is less than 3.11 times the maximum operational primary to secondary leakage rate, the report should describe how it was determined (TS 5.6.9.h); and E2 - 21 of 40

Enclosure 2 Based on the Byron Updated Final Safety Analysis Report (UFSAR) the accident leakage limit for the most limiting accident scenario leading to offsite dose consequences is the steam line break (SLB) accident. For this accident, the limiting accident induced leak rate in the affected SG is 0.5 gpm. If no sec is detected above the tubesheet and in the portion of the tube 14.01 inches from the top of the tubesheet and no wear induced leakage exists, then the entire accident induced allowable leakage (0.5 gpm) divided by 3.11 can be allocated to the tubesheet expansion region below 14.01 inches from the top of the tubesheet. Effectively, this means that 0.16 gpm leakage (0.5 gpm/3.11) is allowed during operation from the faulted SG within the portion of the tubes below 14.01 inches from the top of the tubesheet. Therefore, no administrative limit on operational leakage is necessary since the more limiting 150 gpd (0.104 gpm) TS operational leakage limit assures that the 0.5 gpm accident leakage limit is not exceeded.

For Unit 2, the results of monitoring for tube axial displacement (slippage). If slippage is discovered, the implications of the discovery and corrective action shall be provided (TS 5.6.9.i).

The bobbin data collected from all SGs were screened by automated data analysis for large amplitude tubesheet indications of greater than 50 volts with a phase angle between 25° and 50° suggestive of tube severance with tube slippage. No indications of tube slippage were detected during the B2R23 inspection. Additionally, the 100% full-length array probe inspections did not identify any signals indicative of tube severance (i.e., tube slippage) within the tubesheet.

References

1. Constellation Energy Generation letter to NRC, BYRON 2022-0072, "Byron Station, Unit 2 Steam Generator Tube Inspection Report for Refueling Outage 23", dated October 27, 2022 (ML22300A049)

2. NRC letter to CEG, "BYRON STATION, UNIT NOS. 1 AND 2 - ISSUANCE OF AMENDMENTS 231 AND 231 RE: ADOPTION OF TSTF-577, "REVISED FREQUENCIES FOR STEAM GENERATOR TUBE INSPECTIONS," REVISION 1 (EPID L-2022-LLA-0115)",

dated December 28, 2022 (ML22305A699)

3. CEG letter to NRC, "Byron Station Unit 2, Steam Generator Tube Inspection Report for Refueling Outage 23" dated October 27, 2022 (ML22300A049)

4. Steam Generator Management Program: Steam Generator Integrity Assessment Guidelines, Revision 5, EPRI, Palo Alto, CA, December 2021 (3002020909)

5. Letter from H. Welt (Constellation Energy Generation, LLC) to NRC, "Byron Station, Unit 1 and Unit 2, Steam Generator Tube Inspection Report to Reflect TSTF-577 Reporting Requirements," dated April 6, 2023 (ADAMS Accession No. ML23096A144)

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Enclosure 2 ATTACHMENT A Anti-Vibration Bar (AVB) Wear Indications (SG 2A)

SG Row Col Volts Per Locn lnchl SG Row Col Volts Per Locn lnchl 2A 19 5 0.72 11 AV4 0.29 2A 37 19 1.99 25 AVl 0.19 2A 20 6 0.61 10 AV4 0 2A 37 19 3.94 36 AV3 -0.17 2A 25 7 1.12 15 AV2 -0.09 2A 37 19 0.92 15 AV4 0.03 2A 24 8 0.4 6 AVl 0.29 2A 38 19 1.43 20 AV3 0.2 2A 25 8 0.55 8 AVl 0.28 2A 38 19 1.68 22 AV4 0.08 2A 25 8 2.18 24 AV3 0.09 2A 37 20 0.76 13 AV2 -0.25 2A 25 8 0.87 12 AV4 0.03 2A 37 20 1.98 24 AV3 0.05 2A 26 8 0.73 11 AV3 0.33 2A 38 20 2.98 30 AVl -0.03 2A 29 10 4.99 40 AV3 0 2A 38 20 2.16 26 AV2 0.39 2A 29 11 0.54 10 AV2 0 2A 38 20 1.4 19 AV3 -0.33 2A 29 11 1.31 19 AV3 0 2A 38 20 1.84 23 AV4 -0.35 2A 29 12 0.96 15 AV2 0.25 2A 36 21 1.51 21 AV3 -0.41 2A 29 12 2.31 27 AV3 -0.45 2A 36 21 1.07 17 AV4 0 2A 29 13 1.31 19 AV3 0 2A 37 21 1.22 18 AV3 0 2A 31 14 1.63 22 AV3 0.02 2A 38 21 1.6 22 AVl -0.39 2A 31 14 1.52 21 AV4 0 2A 38 21 1.18 18 AV3 0.03 2A 34 14 2.04 25 AV2 0.17 2A 38 21 0.84 14 AV4 0.16 2A 34 14 0.98 16 AV3 0.19 2A 39 21 0.68 12 AVl 0 2A 31 15 0.63 11 AV3 0.07 2A 39 21 3.19 32 AV3 0 2A 31 15 0.54 10 AV4 -0.21 2A 39 21 1.21 18 AV4 0 2A 35 15 1.58 21 AV3 0 2A 31 22 0.8 13 AV4 -0.26 2A 35 15 0.95 15 AV4 -0.28 2A 38 22 1.78 23 AV2 0.46 2A 36 15 1 16 AV3 0.01 2A 38 22 1.34 19 AV3 -0.35 2A 36 15 1.87 24 AV4 -0.08 2A 40 22 0.6 10 AV3 0.16 2A 35 16 3.1 31 AV2 0.11 2A 41 22 3.93 36 AV2 0.05 2A 35 16 1.39 19 AV3 0.36 2A 37 23 2.23 26 AV2 0.3 2A 35 16 1.04 16 AV4 -0.44 2A 37 23 2.42 28 AV3 0 2A 37 16 0.57 10 AV3 -0.02 2A 37 23 1.07 16 AV4 0 2A 37 16 1.15 18 AV4 0.15 2A 38 23 1.71 23 AVl 0 2A 38 16 2.02 25 AV3 -0.14 2A 38 23 1.1 17 AV2 -0.32 2A 38 16 1.57 21 AV4 0.06 2A 38 23 2.89 31 AV3 0 2A 37 17 2.72 30 AV3 0 2A 38 23 2.32 27 AV4 0 2A 27 18 1.11 17 AVl -0.1 2A 39 23 2.39 28 AV2 -0.14 2A 35 18 0.56 10 AV3 0.17 2A 39 23 2.3 27 AV3 0.03 2A 36 18 1.48 20 AV2 0.08 2A 39 23 1.25 18 AV4 -0.36 2A 36 18 1.56 21 AV3 -0.3 2A 42 23 0.91 15 AV2 0 2A 37 18 1.92 24 AV2 -0.33 2A 42 23 1.02 16 AV3 0 2A 37 18 1.03 16 AV4 0.37 2A 42 23 0.64 11 AV4 0 E2 - 23 of 40

Enclosur e 2 ATTACHMENT A Anti-Vibration Bar (AVB) Wear Indications (SG 2A)

SG Row Col Volts Per Locn lnchl SG Row Col Volts Per Locn lnchl 2A 43 23 1.1 17 AV4 0 2A 42 42 0.86 14 AV2 -0.3 2A 38 24 1.8 23 AV2 0 2A 40 46 1.07 17 AVl -0.13 2A 38 24 1.4 19 AV3 -0.25 2A 40 46 1.74 23 AV2 0.3 2A 42 24 0.59 10 AV3 -0.16 2A 40 46 3.53 34 AV3 0 2A 43 24 1.09 17 AV4 -0.31 2A 31 50 0.8 13 AV2 0 2A 42 25 0.85 14 AVl 0.05 2A 25 51 0.78 12 AV4 -0.54 2A 42 25 1.75 23 AV2 -0.47 2A 48 55 0.7 12 AV4 0 2A 42 25 1.53 21 AV4 0.08 2A 42 56 0.92 15 AVl 0.38 2A 42 25 7.19 47 AV3 0 2A 42 56 1.2 18 AV2 -0.11 2A 45 25 1.4 20 AV3 0 2A 42 56 1.71 23 AV4 0.44 2A 45 25 1.31 19 AV4 0.05 2A 42 56 7.82 49 AV3 0 2A 38 26 1.99 24 AV2 0.44 2A 48 56 2.11 26 AV3 -0.31 2A 38 27 0.93 15 AV3 -0.28 2A 48 56 1.58 22 AV4 -0.12 2A 42 27 1.16 17 AV3 0.17 2A 40 59 1.33 18 AV3 0.2 2A 47 28 0.74 13 AV4 0.21 2A 40 59 0.76 11 AV4 0 2A 29 29 0.69 12 AV3 0 2A 44 59 1.04 14 AV3 0 2A 33 30 0.78 13 AV3 0.06 2A 47 59 1.32 18 AVl 0.13 2A 38 30 0.71 12 AV2 0.35 2A 47 59 1.17 16 AV2 -0.03 2A 38 30 1.7 22 AV3 -0.36 2A 47 59 0.63 10 AV3 0.11 2A 38 30 0.76 13 AV4 0.09 2A 9 61 1.58 17 AV4 0.96 2A 37 31 0.56 10 AV2 -0.18 2A 37 61 1.05 12 AV3 0.14 2A 37 31 0.7 12 AV3 -0.3 2A 42 61 0.56 10 AVl 0.37 2A 42 32 1.01 16 AV2 -0.14 2A 38 63 3.23 29 AV2 0.12 2A 42 32 0.52 10 AV3 0 2A 38 63 3.77 33 AV3 0.05 2A 25 33 1.06 16 AV2 0 2A 38 63 1.04 12 AV4 0.13 2A 41 33 1.1 17 AV2 0.07 2A 20 64 1.5 20 AVl 0.33 2A 41 33 1.52 21 AV3 -0.44 2A 31 64 1.92 24 AV4 -0.03 2A 42 33 0.97 16 AV3 -0.37 2A 40 64 1.28 18 AVl -0.49 2A 29 34 1.12 17 AV3 0 2A 46 64 1.18 16 AV2 0 2A 38 34 1.05 17 AV2 0.12 2A 46 64 4.66 39 AV3 -0.46 2A 38 34 1.56 22 AV3 0 2A 46 64 4.56 38 AV4 -0.38 2A 48 34 0.51 10 AV4 -0.24 2A 40 66 1.14 16 AVl 0.29 2A 29 35 0.49 9 AVl 0 2A 40 66 0.79 13 AV2 0.11 2A 29 35 1.09 16 AV3 0 2A 31 67 1 12 AV2 0 2A 39 35 1.04 16 AV3 0.07 2A 31 67 0.59 8 AV4 0.38 2A 37 36 0.68 12 AV4 0.14 2A 30 68 0.74 13 AV2 0.14 2A 45 36 0.99 16 AV2 0.14 2A 30 68 0.66 12 AV3 0.25 2A 40 42 0.63 11 AV2 0 2A 30 69 1.53 18 AV2 -0.18 E2 - 24 of 40

Enclosure 2 ATTACHMENT A Anti-Vibration Bar (AVB) Wear Indications (SG 2A)

SG Row Col Volts Per Locn lnchl SG Row Col Volts Per Locn lnchl 2A 30 69 1.46 18 AV3 -0.22 2A 34 89 0.64 12 AV2 -0.05 2A 37 69 0.95 11 AV3 -0.32 2A 39 89 4.37 38 AV3 -0.13 2A 30 70 0.82 13 AV2 0 2A 39 89 3.48 34 AV2 0.46 2A 30 70 0.66 11 AV4 0 2A 39 89 1.52 22 AV4 -0.32 2A 30 70 0.53 10 AV3 0 2A 40 89 1.68 22 AV3 -0.14 2A 38 72 2.22 26 AV3 0.03 2A 41 89 1.23 19 AV2 0.47 2A 38 72 1.4 19 AV4 -0.35 2A 41 89 0.67 12 AV3 0.08 2A 38 73 3.36 32 AV3 0 2A 45 89 1.76 23 AV4 0.14 2A 38 73 1.02 13 AV2 0.02 2A 34 90 2.11 25 AV3 -0.48 2A 32 76 1.17 17 AV3 0.06 2A 40 90 2.55 28 AV3 0.26 2A 43 78 0.91 15 AVl 0.19 2A 40 90 2.18 26 AV2 0 2A 32 79 1.59 19 AV4 0 2A 40 90 1.27 18 AV4 0.12 2A 32 79 1.22 15 AV3 0.09 2A 44 90 4.78 39 AV3 0 2A 44 79 1.14 15 AV2 -0.2 2A 44 90 1.5 21 AV2 0 2A 40 82 2.34 26 AV2 0 2A 44 90 1.6 21 AV4 -0.34 2A 40 82 1.38 19 AV3 0.08 2A 34 91 0.68 13 AV3 0.11 2A 44 82 0.61 10 AV3 0.06 2A 40 91 6.79 46 AV3 0 2A 39 84 1.37 20 AV2 0.49 2A 40 91 2.7 29 AV2 0 2A 41 84 1.52 21 AV3 0.57 2A 36 92 1.41 20 AV3 0.11 2A 41 84 1.28 19 AV2 0.4 2A 40 92 1.86 24 AV2 0 2A 27 85 3.11 32 AV2 0.41 2A 40 92 0.93 15 AV3 0 2A 27 85 1.01 17 AV3 0.03 2A 41 92 3.44 34 AV2 0.05 2A 27 85 0.95 16 AVl -0.39 2A 41 92 2.03 26 AV4 -0.11 2A 39 85 1.47 21 AV2 0.38 2A 41 92 1.22 19 AV3 0.17 2A 39 85 0.78 14 AV3 -0.05 2A 34 94 0.84 14 AV2 0.38 2A 40 85 1.82 24 AV3 0.09 2A 39 94 5.43 41 AV3 0.06 2A 41 85 3.29 33 AV2 0.03 2A 39 94 2 26 AV2 0.08 2A 41 85 2.01 26 AV3 0.2 2A 39 94 1.23 19 AVl 0.32 2A 41 85 0.73 13 AV4 0.18 2A 34 95 1.15 18 AV2 0 2A 39 86 1.64 22 AV3 0 2A 36 95 1.22 19 AV3 -0.33 2A 39 86 1.59 21 AV2 0.36 2A 36 95 0.78 14 AV4 0.09 2A 39 86 1.16 17 AV4 0.21 2A 40 95 3.98 36 AV2 0.03 2A 40 87 0.83 15 AV2 0.22 2A 40 95 3.38 33 AVl 0 2A 41 88 1.5 21 AV2 0.14 2A 40 95 3.31 33 AV3 0.08 2A 44 88 4.29 37 AV3 0.46 2A 40 95 2.86 30 AV4 0 2A 44 88 2.2 26 AV4 -0.08 2A 36 96 2.84 30 AV2 -0.03 2A 44 88 2.09 25 AV2 0.17 2A 38 96 0.92 16 AV2 0.01 2A 34 89 0.84 15 AV3 -0.6 2A 39 96 1.75 23 AV3 -0.43 E2 - 25 of 40

Enclosure 2 ATTACHMENT A Anti-Vibration Bar (AVB) Wear Indications (SG 2A)

SG Row Col Volts Per Locn lnchl SG Row Col Volts Per Locn lnchl 2A 39 96 1.35 19 AV4 0.41 2A 23 109 1.1 15 AVl 0.03 2A 37 98 3.7 35 AV2 -0.53 2A 23 109 0.45 7 AV4 -0.36 2A 37 98 3.88 35 AV3 0.08 2A 37 98 0.85 14 AV4 0.14 2A 38 98 1.41 20 AVl 0.03 2A 38 98 2.95 31 AV2 0 2A 38 98 1.4 20 AV3 0 2A 28 99 1.04 16 AVl 0.17 2A 32 99 1.26 19 AV3 -0.3 2A 34 99 1.18 19 AV3 -0.3 2A 37 99 0.99 16 AV2 -0.4 2A 37 99 1.69 22 AV3 0.09 2A 35 100 1.5 21 AV3 0.2 2A 31 101 1.59 21 AV2 0 2A 31 101 2.74 30 AV3 0 2A 33 102 0.83 14 AV4 0.19 2A 30 103 1.52 21 AV2 0.34 2A 31 103 1.76 23 AV2 0 2A 31 103 1.64 22 AV3 0 2A 31 103 0.86 14 AV4 0.05 2A 27 104 1.18 16 AV2 0.08 2A 28 104 1.15 16 AV4 0.2 2A 29 104 0.91 13 AV3 0.08 2A 30 104 1.31 18 AV2 0.5 2A 30 104 0.68 11 AV3 -0.08 2A 28 105 0.97 15 AV3 -0.26 2A 28 105 1.84 23 AV4 0.02 2A 30 105 0.67 10 AV2 0.03 2A 24 106 0.54 9 AV4 -0.03 2A 25 106 0.65 10 AVl 0.33 2A 26 106 1.18 16 AVl -0.41 2A 26 106 0.87 13 AV3 0.03 2A 27 106 1.54 20 AVl 0.03 2A 27 106 1.76 22 AV2 0 2A 27 106 2.42 27 AV3 0.63 2A 26 107 1.04 15 AV2 -0.33 2A 26 107 1.45 19 AV3 0.11 2A 22 109 0.57 9 AV4 0.24 E2 - 26 of 40

Enclosure 2 ATTACHMENT A Anti-Vibration Bar (AVB) Wear Indications (SG 28)

SG Row Col Volts Per Locn lnchl SG Row Col Volts Per Locn lnchl 2B 21 6 0.88 11 AV4 0 2B 33 14 1.42 20 AV4 -0.35 2B 23 7 1 12 AV4 0.08 2B 35 14 1.36 19 AV1 0.11 2B 25 8 1.24 15 AV2 0 2B 35 14 1.95 23 AV2 -0.11 2B 25 8 0.7 12 AV3 0 2B 35 14 0.81 13 AV3 -0.22 2B 27 10 0.9 14 AV2 0.3 2B 31 15 2.39 27 AV2 0 2B 28 11 0.86 16 AV2 0 2B 31 15 0.83 14 AV4 -0.24 2B 28 11 3.13 32 AV3 0 2B 35 15 2.76 29 AV2 -0.03 2B 28 11 1.48 22 AV4 0 2B 31 16 0.89 15 AV1 -0.28 2B 27 12 0.77 15 AV3 0.3 2B 31 16 1.72 22 AV3 -0.32 2B 28 12 0.64 14 AV1 0.16 2B 32 16 1.25 18 AV2 -0.3 2B 28 12 1.09 19 AV2 -0.08 2B 32 16 1.14 17 AV3 0.08 2B 28 12 0.42 10 AV4 0 2B 34 16 0.87 13 AV3 -0.33 2B 30 12 1.16 17 AV2 0.19 2B 35 16 0.9 15 AV1 0.35 2B 30 12 1.49 20 AV3 0.08 2B 35 16 2.16 26 AV3 -0.41 2B 31 12 2.31 26 AV1 0.49 2B 36 16 1.01 15 AV1 -0.14 2B 31 12 3.37 32 AV2 0.03 2B 36 16 2.59 28 AV2 0.17 2B 31 12 5.18 40 AV3 -0.25 2B 36 16 4.8 38 AV3 -0.45 2B 31 12 2.27 26 AV4 0.03 2B 36 16 1.8 22 AV4 0.19 2B 32 12 1.08 16 AV1 0 2B 31 17 0.95 15 AV2 0.33 2B 32 12 2.55 28 AV2 0 2B 31 17 1.37 19 AV3 0.19 2B 32 12 0.48 8 AV3 0 2B 34 17 1.31 18 AV3 0.05 2B 32 12 1.54 20 AV4 0.11 2B 34 17 0.74 12 AV4 0 2B 29 13 0.6 11 AV3 -0.03 2B 36 17 0.98 15 AV1 -0.33 2B 30 13 1.11 16 AV3 0.05 2B 36 17 1.89 23 AV2 0.13 2B 30 13 0.57 10 AV4 0.02 2B 36 17 0.87 13 AV3 0.05 2B 31 13 0.66 12 AV1 0.03 2B 37 17 1.64 20 AV2 0.19 2B 31 13 1.24 18 AV2 0.22 2B 37 17 1.01 15 AV3 0 2B 31 13 0.96 15 AV3 0.08 2B 28 18 0.77 15 AV4 0.16 2B 31 13 1.28 19 AV4 0.05 2B 34 18 1.14 16 AV4 0.11 2B 33 13 1.36 19 AV1 0.11 2B 36 18 1.5 20 AV2 0.1 2B 33 13 1.02 15 AV3 -0.05 2B 36 18 1.1 15 AV3 0.14 2B 28 14 1.01 18 AV2 0.16 2B 31 19 1.09 17 AV1 -0.53 2B 28 14 0.97 17 AV4 0.28 2B 34 19 0.81 13 AV3 0.1 2B 30 14 1.02 15 AV3 0 2B 37 19 2.64 28 AV2 -0.12 2B 30 14 0.79 13 AV4 0 2B 39 19 3.03 30 AV2 0.16 2B 33 14 2.94 30 AV1 0.14 2B 39 19 2.33 26 AV3 -0.38 2B 33 14 3.5 33 AV2 0.46 2B 39 19 1.81 23 AV4 -0.25 2B 33 14 1.37 19 AV3 0.19 2B 35 20 1.13 17 AV3 0.11 E2 - 27 of 40

Enclosure 2 ATTACHMENT A Anti-Vibration Bar (AVB) Wear Indications (SG 28)

SG Row Col Volts Per Locn lnchl SG Row Col Volts Per Locn lnchl 28 36 20 1.13 16 AV1 -0.1 28 28 29 1.11 17 AV2 0 28 36 20 2.05 24 AV2 -0.05 28 28 29 0.95 16 AV3 -0.03 28 36 20 1.28 18 AV3 0.17 28 36 29 1.1 17 AV2 0.08 28 39 20 1.4 19 AV2 0.25 28 36 29 1.1 17 AV3 0.11 28 40 20 2.84 30 AV2 0.05 28 39 29 0.78 13 AV3 0 28 40 20 2.38 27 AV3 0.06 28 41 29 1.26 18 AV3 0 28 40 20 1.23 18 AV4 0.08 28 43 29 1.59 21 AVl 0 28 39 21 1.52 20 AV2 0.11 28 43 29 4.43 37 AV2 0 28 39 21 1.26 18 AV3 -0.05 28 43 29 1.14 17 AV3 0 28 36 23 1.62 21 AV2 0.11 28 45 29 0.81 13 AV4 0 28 40 23 0.7 13 AV4 -0.11 28 34 30 1.05 15 AV1 -0.08 28 40 24 2.24 26 AV2 0 28 34 30 1.21 17 AV2 -0.25 28 43 25 4.16 36 AV2 0.38 28 34 30 2.4 26 AV3 0 28 43 25 2.71 28 AV3 -0.11 28 34 30 0.99 15 AV4 0 28 43 25 1.14 16 AV4 -0.11 28 27 31 0.88 17 AV3 0.02 28 45 25 0.9 14 AV4 0 28 27 31 1.42 23 AV4 0 28 34 26 1.89 23 AV3 0 28 48 31 0.55 10 AV4 0.11 28 35 26 0.93 15 AV2 0 28 49 31 0.97 15 AV1 0.08 28 39 26 2.13 25 AV2 0 28 49 31 0.86 14 AV3 0.11 28 39 26 0.65 11 AV3 0 28 49 31 0.7 12 AV4 -0.27 28 40 26 1.06 16 AV2 0.33 28 28 32 1.25 18 AV2 0.32 28 44 26 2.97 31 AV2 0.49 28 28 32 0.66 13 AV3 0 28 44 26 1.09 18 AV3 -0.11 28 31 32 0.75 14 AVl 0.3 28 45 26 2.75 29 AV2 0.41 28 31 32 0.85 15 AV2 0.24 28 45 26 4 35 AV3 -0.35 28 32 32 0.95 15 AV1 0.11 28 45 26 2.12 25 AV4 0.1 28 32 32 1.65 22 AV2 -0.05 28 28 27 1.21 17 AV2 0 28 32 32 2.55 28 AV3 -0.05 28 28 27 0.95 14 AV3 -0.13 28 32 32 0.98 16 AV4 0.14 28 39 27 1.4 19 AV2 0.22 28 35 32 0.67 13 AV2 -0.27 28 39 27 1.4 19 AV3 0.17 28 45 32 1.44 21 AV2 0.19 28 40 27 1.1 17 AV2 0.41 28 45 32 1.94 24 AV3 0.33 28 40 27 1.97 24 AV3 -0.35 28 34 33 1.97 24 AV2 0.38 28 40 27 0.52 10 AV4 0.17 28 34 33 0.95 15 AV3 0.14 28 32 28 1.87 23 AV2 0.39 28 39 33 1.17 17 AV2 0.41 28 32 28 1.39 20 AV3 0 28 39 33 1.5 20 AV3 0.11 28 32 28 1.35 20 AV4 0 28 39 33 1.05 16 AV4 -0.16 28 27 29 0.8 15 AV2 0.37 28 40 33 0.84 13 AV2 0.25 28 27 29 1.1 19 AV3 0.3 28 40 33 1.01 15 AV3 -0.38 E2 - 28 of 40

Enclosur e 2 ATTACHMENT A Anti-Vibration Bar (AVB) Wear Indications (SG 28)

SG Row Col Volts Per Locn lnchl SG Row Col Volts Per Locn lnchl 2B 42 33 0.97 15 AV2 0.38 28 40 41 1.58 21 AV2 0.32 2B 49 33 0.81 13 AVl 0.16 2B 40 41 2.97 30 AV3 -0.51 2B 49 33 0.7 13 AV4 0 2B 32 42 0.62 12 AV3 -0.08 2B 31 34 0.82 15 AV3 0.14 2B 41 43 1.9 23 AVl -0.3 2B 40 34 0.78 13 AVl -0.06 2B 41 43 3.83 34 AV2 0 2B 40 34 3.96 35 AV2 0.35 2B 41 43 4.75 38 AV3 -0.4 2B 40 34 0.8 14 AV3 0 2B 42 44 8.76 50 AV3 0 2B 42 34 0.85 14 AV2 0.3 28 42 44 3.04 31 AV2 0.13 2B 40 35 0.86 13 AV3 -0.19 28 42 44 1.76 24 AV4 0.03 2B 32 36 1.51 21 AV2 0.38 2B 21 45 1.1 16 AV4 0.17 2B 32 36 1.23 18 AV3 0 28 40 45 1.16 17 AV2 0 2B 34 36 1.38 21 AV2 0.22 2B 44 45 0.9 14 AV2 0.21 2B 34 36 0.61 12 AV3 -0.08 2B 44 45 2.04 24 AV3 -0.54 2B 42 36 1.38 20 AV2 0.35 2B 28 46 1.12 17 AV2 0.05 2B 45 36 0.83 15 AV2 0.32 2B 49 49 0.93 16 AVl 0.14 2B 45 36 2.99 31 AV3 -0.16 2B 31 52 0.9 17 AV2 0.05 2B 45 36 3.14 31 AV4 0 2B 40 54 1.57 23 AV2 0 2B 28 37 1.4 19 AV3 -0.11 2B 40 54 1.47 20 AV3 0.28 2B 42 37 1.29 18 AVl 0.25 2B 47 56 1.23 18 AVl 0 2B 42 37 2.04 24 AV2 0.33 2B 47 56 2.71 30 AV2 0 2B 42 37 2.46 27 AV3 0 2B 40 59 2.7 28 AV3 0.06 2B 49 37 0.8 13 AVl 0.03 2B 40 59 1.1 15 AV4 0 2B 49 37 0.56 10 AV3 -0.11 2B 42 68 1.08 15 AVl 0.13 2B 28 38 0.58 12 AV3 0.11 2B 42 68 2.77 28 AV2 0 2B 31 38 0.74 14 AV2 0.08 2B 42 68 2.57 27 AV3 0.02 2B 39 38 1.78 24 AV2 -0.11 2B 42 68 0.98 14 AV4 0.12 2B 39 38 2.08 24 AV3 0.08 2B 39 69 1.14 17 AV3 0.22 2B 10 39 1.15 16 AV4 0.78 2B 38 71 1.25 19 AVl -0.24 2B 32 39 0.99 15 AV3 0.27 2B 38 71 1.42 20 AV2 0.24 2B 32 39 0.71 12 AV4 0.25 2B 38 71 3.17 32 AV3 -0.04 2B 34 39 1.15 18 AV2 -0.02 2B 38 71 1.26 19 AV4 0.17 2B 39 39 0.98 16 AVl 0.27 2B 33 72 2.58 29 AV3 0 2B 39 39 1.31 18 AV2 -0.36 2B 33 72 1.21 19 AV4 -0.05 2B 42 39 0.67 12 AV3 0.15 2B 40 72 0.79 15 AV3 -0.35 2B 46 39 1.12 16 AV2 -0.11 2B 39 76 1.03 16 AV2 0.38 2B 46 39 2.02 24 AV3 -0.11 2B 39 76 1.14 17 AV3 0 2B 32 40 1.04 18 AV2 0.28 2B 41 76 1.22 18 AVl -0.07 28 32 40 1.07 18 AV3 0.26 2B 44 76 2.41 27 AV2 0.19 28 32 40 1.01 17 AV4 0.05 2B 44 76 1.73 23 AV3 -0.12 E2 - 29 of 40

Enclos ure 2 ATTACH MENT A Anti-Vibration Bar (AVB) Wear Indications (SG 28)

SG Row Col Volts Per Locn lnchl SG Row Col Volts Per Locn lnchl 28 44 76 1.16 18 AV4 -0.19 28 42 89 2.38 27 AV3 0 28 28 77 1.09 18 AV2 0.23 28 42 89 1.26 18 AV4 0 28 39 77 0.9 16 AV3 0.07 28 44 89 1.34 18 AV4 0.11 28 36 78 1.96 24 AV3 0 28 45 89 0.83 13 AVl -0.08 28 36 78 0.65 12 AV4 0 28 45 89 4.81 38 AV2 0.49 28 28 79 0.56 11 AV2 0.32 28 45 89 2.11 24 AV3 0.33 28 28 79 0.72 14 AV3 -0.39 28 36 90 0.89 13 AV2 -0.25 28 41 79 1.21 19 AV3 -0.28 28 36 90 1.42 19 AV3 -0.46 28 41 79 0.77 14 AV4 -0.1 28 37 90 1.08 15 AV2 0.41 28 36 80 1.51 20 AV3 0.06 28 37 90 1.37 18 AV3 0.11 28 44 82 1.1 16 AV3 0.06 28 44 90 1.01 15 AV2 0.32 28 30 83 0.84 15 AV4 -0.48 28 44 90 4.68 38 AV3 0 28 37 83 1.19 17 AV2 0.4 28 44 90 1.29 17 AV4 0.03 28 41 83 1.04 16 AV2 0.12 28 25 91 0.84 14 AV3 0 28 45 83 2.16 25 AV2 0.08 28 40 91 1.63 21 AV2 0 28 45 83 1.99 24 AV3 0 28 42 91 0.97 15 AV2 0 28 45 83 1.3 19 AV4 0 28 42 91 1.11 17 AV3 0 28 42 84 1.47 19 AV2 0.43 28 42 91 1.17 17 AV4 0.15 28 42 84 1.57 20 AV3 0.11 28 43 91 0.97 15 AV2 0 28 41 85 1.56 21 AV2 0 28 43 91 2.86 30 AV3 0 28 44 85 1.76 23 AV2 0 28 43 91 0.95 15 AV4 0 28 44 85 4.27 36 AV3 0 28 36 92 0.85 13 AV4 -0.43 28 44 85 2.52 28 AV4 0.05 28 37 92 4.21 36 AV2 0.49 28 42 86 1.89 23 AV2 0.38 28 38 92 1.52 20 AV2 -0.05 28 45 86 1.61 20 AVl 0.11 28 38 92 1.01 15 AV3 0.41 28 45 86 3.54 33 AV2 0.59 28 38 92 1.37 18 AV4 0.45 28 45 86 1.95 23 AV3 0.36 28 39 92 1.92 23 AV3 -0.3 28 28 87 0.69 12 AV2 -0.15 28 39 92 1.86 22 AV4 -0.27 28 28 87 1.15 17 AV3 0.02 28 40 92 3.41 32 AV3 0.47 28 41 87 2.04 25 AVl -0.03 28 40 92 0.78 12 AV4 0.26 28 41 87 3.86 35 AV2 0 28 43 92 1.6 20 AV3 0.43 28 41 87 2.39 27 AV3 0.11 28 37 93 1.12 17 AV2 0 28 41 87 1.26 18 AV4 0.1 28 37 93 3.56 33 AV3 0 28 36 88 1.81 22 AV3 -0.43 28 38 93 0.95 15 AVl 0 28 39 88 1.85 22 AV2 -0.14 28 38 93 1.15 17 AV2 0.22 28 25 89 1.27 18 AV4 0.31 28 38 93 1.62 21 AV3 -0.26 28 36 89 1.01 15 AV2 0 28 38 93 1.2 17 AV4 0 28 42 89 3.63 34 AVl 0 28 39 93 1.11 16 AV2 0 28 42 89 4.66 38 AV2 0 28 39 93 2.2 26 AV3 0.06 E2 - 30 of 40

Enclosur e 2 ATTACHM ENT A Anti-Vibration Bar (AVB) Wear Indications (SG 2B)

SG Row Col Volts Per Locn lnchl SG Row Col Volts Per Locn lnchl 2B 39 93 0.8 13 AV4 0 2B 33 97 3.09 31 AV3 0.35 2B 41 93 1.41 19 AVl -0.05 2B 35 97 0.81 12 AV2 0.03 2B 41 93 2.24 25 AV2 0 2B 35 97 4.46 37 AV3 0.11 2B 41 93 3.16 31 AV3 0.03 2B 35 97 1.33 18 AV4 0.14 2B 41 93 1.9 23 AV4 -0.49 2B 20 98 1.2 17 AV4 0.03 2B 43 93 1.27 17 AV4 0.06 2B 29 98 1.46 19 AV2 -0.32 2B 25 94 1.06 15 AV4 -0.03 2B 29 98 1.28 17 AV4 -0.51 2B 36 94 1.85 22 AV2 0.38 2B 32 98 1.88 22 AV3 -0.35 2B 36 94 0.89 13 AV3 0.11 2B 32 98 0.94 14 AV4 0.06 2B 36 94 1.15 16 AV4 -0.35 2B 33 98 1.67 21 AV2 -0.27 2B 37 94 1.09 15 AV2 0.16 2B 33 98 2.29 25 AV3 -0.03 2B 37 94 0.95 14 AV3 -0.35 2B 33 98 1.11 16 AV4 -0.03 2B 39 94 2.23 25 AV2 0.03 2B 35 98 2.18 25 AVl 0.14 2B 39 94 4.17 36 AV3 -0.4 2B 35 98 0.96 14 AV2 0.35 2B 39 94 1.87 22 AV4 -0.41 2B 35 98 1.64 21 AV3 0.11 2B 40 94 1 15 AVl 0 2B 35 98 1.8 22 AV4 0.16 2B 40 94 3.95 35 AV2 0 2B 28 99 1.28 18 AV2 0 2B 33 95 1.18 17 AV3 0.03 2B 28 99 0.93 15 AV4 -0.38 2B 34 95 1.07 16 AV3 0.13 2B 29 99 1.11 16 AV4 0.15 28 38 95 4.89 39 AVl 0 2B 30 99 1.47 20 AV3 0 2B 38 95 2.03 24 AV2 -0.13 2B 32 99 1.89 24 AV3 0 2B 38 95 1.98 24 AV3 0 2B 33 99 1.44 20 AVl -0.26 2B 38 95 1.8 23 AV4 0 2B 33 99 2.57 28 AV2 0 2B 39 95 2.1 25 AV2 0 2B 33 99 1.95 24 AV3 0.05 28 39 95 1.84 23 AV3 0.08 2B 33 99 0.95 15 AV4 0.2 28 39 95 2.05 25 AV4 -0.03 2B 34 99 0.9 14 AV3 0.03 28 40 95 1.34 18 AV3 0.14 2B 34 99 0.86 14 AV4 0.05 2B 40 95 1.37 18 AV4 -0.41 2B 35 99 0.82 14 AV2 0 2B 41 95 2.59 27 AVl -0.05 2B 35 99 1.26 18 AV3 0 2B 41 95 4.58 37 AV2 0.03 2B 35 99 1.28 18 AV4 0 2B 41 95 2.67 28 AV3 -0.46 2B 29 100 1.11 16 AV2 -0.16 2B 35 96 1.73 21 AV3 0 2B 31 100 0.98 14 AV2 0.35 2B 38 96 3.08 30 AVl -0.35 2B 32 100 0.62 10 AV3 0.05 2B 38 96 2.2 25 AV2 0.11 2B 34 100 1.94 23 AV3 0.16 2B 38 96 1.37 18 AV3 -0.4 2B 34 100 1.49 19 AV4 0.35 2B 38 96 3.16 31 AV4 0.27 2B 35 100 2.44 26 AV2 -0.4 2B 19 97 0.91 15 AV4 0 2B 35 100 1.58 20 AV3 0.05 2B 29 97 1.21 17 AV4 0.07 2B 35 100 2.88 29 AV4 -0.03 28 32 97 0.97 15 AV4 0 2B 30 101 1.33 21 AVl -0.03 E2 - 31 of 40

Enclosure 2 ATTACHMENT A Anti-Vibration Bar (AVB) Wear Indications (SG 28)

SG Row Col Volts Per Locn lnchl SG Row Col Volts Per Locn lnchl 2B 30 101 0.83 16 AV2 -0.16 2B 25 108 1.03 14 AV3 0.3 2B 30 101 0.97 17 AV4 0.24 2B 25 108 2.38 26 AV4 0 2B 35 101 4.34 36 AV3 0.08 2B 22 109 1.26 16 AV1 -0.03 2B 35 101 3 30 AV4 -0.41 2B 21 110 0.68 12 AV4 0.13 2B 28 102 1.68 20 AV3 0.16 2B 30 102 3.29 32 AV2 0 2B 30 102 1.29 18 AV3 0.3 2B 30 102 1.39 19 AV4 0 2B 31 102 1.73 22 AV3 0.16 2B 34 102 1.58 20 AV4 -0.38 2B 25 103 1.98 23 AV2 0.37 2B 28 103 1.76 21 AV1 0.16 2B 28 103 1.86 23 AV2 0 2B 28 103 1.98 24 AV3 0 2B 25 104 1.55 19 AV2 0.24 2B 28 104 2.1 25 AV2 0.42 2B 28 104 1.9 23 AV3 0 2B 26 105 2.53 28 AV3 -0.31 2B 27 105 1.34 19 AV1 -0.07 2B 27 105 2.5 27 AV2 0 2B 27 105 2.62 28 AV3 0 2B 27 105 1.09 16 AV4 0 2B 29 105 1.88 23 AV2 0 2B 29 105 1.67 20 AV4 0 2B 30 105 3.39 32 AV4 0 2B 23 106 0.88 12 AV2 -0.03 2B 24 106 1.16 17 AV2 0 2B 25 106 0.48 9 AV2 -0.27 2B 25 106 1.22 16 AV4 0.24 2B 23 107 1.04 14 AV3 0 2B 24 107 1.1 15 AV2 0.32 2B 24 107 0.96 13 AV3 0.16 2B 25 107 1.8 23 AV2 0.38 2B 25 107 1.69 20 AV3 -0.03 2B 26 107 1.34 19 AV2 0.19 2B 23 108 3.29 31 AV2 0.03 2B 23 108 1.04 16 AV3 0 2B 24 108 2.12 24 AV4 0.1 2B 25 108 0.72 12 AV2 0 E2 - 32 of 40

Enclosur e 2 ATTACHM ENT A Anti-Vibration Bar (AVB) Wear Indications (SG 2C)

SG Row Col Volts Per Locn lnchl SG Row Col Volts Per Locn lnchl 2( 21 6 0.72 16 AVl -0.07 2( 36 20 1.08 17 AV3 0.05 2( 22 6 1.44 22 AVl 0 2C 37 20 1.01 16 AV2 -0.08 2( 22 6 1.29 21 AV4 0 2C 37 20 1.02 16 AV3 -0.32 2( 23 6 2.15 29 AV4 0.05 2C 39 20 1.09 17 AV2 0.3 2( 26 8 0.84 18 AVl -0.07 2C 36 21 2.43 28 AV3 0.4 2( 26 8 1.35 23 AV2 -0.32 2( 38 21 0.8 14 AV3 0.03 2( 26 8 0.89 19 AV3 -0.32 2( 40 21 3.66 34 AV2 0.33 2( 26 9 1.27 21 AV2 0.25 2( 40 21 1.42 21 AV3 -0.27 2( 26 9 1.31 21 AV3 0.17 2( 35 22 0.88 14 AVl 0.14 2( 26 9 1.84 25 AV4 -0.37 2( 35 22 2.09 26 AV3 0.11 2( 27 11 0.82 14 AV3 0.02 2( 36 22 1.3 19 AV2 0 2( 29 11 1.6 22 AVl 0.37 2( 36 22 1.23 18 AV3 0.09 2( 31 12 1.08 17 AV3 0.06 2( 38 22 1.73 23 AVl 0.2 2( 26 13 0.56 13 AV2 0.05 2( 38 22 1.23 18 AV2 -0.11 2( 32 13 1.3 19 AV2 0.39 2( 38 22 1.44 20 AV3 0 2( 32 13 1.73 23 AV3 0.27 2C 36 23 0.76 14 AV2 0.24 2( 31 14 1.2 19 AVl 0.31 2C 37 23 1.2 19 AV2 0.33 2( 31 14 1.56 22 AV3 -0.15 2C 37 23 1.05 17 AV3 0.27 2( 34 15 0.74 13 AV2 0 2( 42 23 1.31 18 AV3 0 2( 33 16 0.75 14 AV3 0 2C 36 24 0.99 16 AVl -0.58 2( 38 16 1.97 25 AVl 0.27 2C 36 24 0.93 15 AV2 -0.08 2( 38 16 1.26 18 AV2 0.11 2( 36 24 2.53 29 AV3 0.07 2( 38 16 0.92 15 AV3 0 2( 35 25 0.64 12 AVl 0.27 2( 30 17 0.68 12 AV2 -0.27 2( 35 25 1.88 24 AV2 0 2( 30 17 0.93 15 AV3 -0.39 2( 35 25 1.6 22 AV3 -0.05 2( 36 17 1.04 16 AV3 0.08 2( 36 25 1.59 22 AV2 -0.27 2( 37 17 1.67 23 AVl 0 2( 38 25 1.32 19 AVl 0.36 2( 37 17 1.31 20 AV3 0.39 2C 38 25 1.74 23 AV2 0.5 2( 26 18 0.92 17 AV3 0.31 2( 38 25 1.21 18 AV3 0.22 2( 35 18 1.28 19 AV2 0.27 2( 39 25 1.11 16 AVl 0.05 2C 35 19 1.06 17 AV2 0.06 2C 39 25 0.67 11 AV2 0.43 2( 35 19 1.03 17 AV3 0 2C 42 25 2.16 25 AV3 -0.3 2( 36 19 0.9 15 AV2 0.14 2C 39 26 1.19 17 AV3 0.03 2( 36 19 2.06 25 AV3 0.11 2C 41 26 1.14 18 AV2 0.11 2( 38 19 1.08 17 AV2 -0.29 2C 41 26 1.45 20 AV3 0.22 2( 39 19 1.13 19 AV2 0.06 2C 34 27 2.47 28 AV2 0 2( 39 19 4.16 36 AV3 -0.13 2C 34 27 1.13 18 AV3 0 2( 36 20 0.8 13 AV2 0.46 2C 36 27 1.5 21 AV3 0.03 E2 - 33 of 40

Enclosure 2 ATTACHMENT A Anti-Vibration Bar (AVB) Wear Indications (SG 2C)

SG Row Col Volts Per Locn lnchl SG Row Col Volts Per Locn lnchl 2C 39 27 0.66 11 AVl 0.11 2C 33 39 1.26 20 AV3 -0.34 2C 41 27 1.17 18 AV2 0.08 2C 29 40 1.39 22 AV2 0 2C 31 28 0.65 14 AV2 0.25 2C 29 40 1.33 21 AV3 0.02 2C 32 28 0.92 17 AV2 0.16 2C 39 40 0.62 12 AV2 0.38 2C 32 28 0.95 18 AV3 0.06 2C 39 40 1.1 17 AV3 -0.16 2C 36 28 0.94 18 AV3 0.05 2C 29 41 1.17 20 AV2 0.22 2C 29 29 1.58 23 AV2 0.37 2C 31 42 0.62 13 AV2 0.05 2C 29 29 1.69 24 AV3 -0.32 2C 36 42 1.06 19 AV3 0 2C 34 29 1.23 21 AV2 0.38 2C 29 43 0.83 16 AV2 0.16 2C 34 29 1.11 20 AV3 0.08 2C 29 43 1.81 25 AV4 0 2C 41 29 1.19 18 AV2 -0.03 2C 39 43 0.86 15 AVl 0.3 2C 41 29 0.96 16 AV3 -0.33 2C 29 44 1.01 18 AVl 0.28 2C 42 29 0.74 12 AVl 0 2C 29 44 1.17 20 AV2 0 2C 42 29 1.33 19 AV2 0.33 2C 29 44 1.51 23 AV3 0.08 2C 42 29 2.22 26 AV3 0 2C 37 46 0.88 16 AVl 0 2C 29 30 1.08 19 AV2 0 2C 37 46 1.14 19 AV3 0.11 2C 35 30 2.13 27 AV2 0.29 2C 33 47 0.96 18 AV2 0.19 2C 43 30 1.01 16 AV3 -0.39 2C 31 48 1.08 19 AV2 0 2C 27 34 0.78 13 AV3 0 2C 29 49 0.8 16 AV3 -0.3 2C 37 34 0.95 17 AV3 0 2C 39 49 1.3 21 AVl 0.11 2C 43 34 0.91 15 AV3 0.14 2C 39 49 1.02 18 AV2 0.09 2C 28 35 1.3 20 AV3 0.03 2C 31 50 0.87 17 AVl 0 2C 28 35 1.42 21 AV4 -0.29 2C 33 50 0.82 16 AV3 0.09 2C 30 35 1.52 24 AV3 0 2C 37 50 1.45 22 AV2 0.02 2C 36 35 0.71 15 AV2 0.16 2C 48 56 0.31 7 AV2 0.14 2C 39 35 1.05 17 AVl 0.33 2C 37 60 0.61 11 AV2 0 2C 39 35 3.94 35 AV2 -0.05 2C 37 60 2.08 25 AV3 0 2C 39 35 3.67 34 AV3 -0.45 2C 38 62 1.35 21 AVl -0.35 2C 46 35 1.48 20 AV2 0.05 2C 38 62 2.39 29 AV2 0.02 2C 30 36 0.7 15 AV2 0.22 2C 38 62 1.52 23 AV3 0.07 2C 31 36 1.25 20 AV2 -0.31 2C 41 63 1.31 21 AVl 0 2C 43 36 2.03 25 AV3 0 2C 41 63 2.88 32 AV3 0 2C 43 36 1.04 17 AV4 0 2C 41 63 1.01 18 AV4 0 2C 29 38 0.92 17 AV3 -0.15 2C 41 63 4.94 40 AV2 0.33 2C 29 38 0.98 18 AV4 -0.21 2C 31 64 1.48 22 AV2 -0.08 2C 39 38 1 16 AV2 -0.16 2C 37 64 0.78 15 AV2 0.31 2C 39 38 1.82 23 AV3 -0.35 2C 48 67 0.62 12 AV4 0.18 2C 33 39 1.29 21 AV2 -0.16 2C 44 72 0.87 16 AVl 0.06 E2 - 34 of 40

Enclosure 2 ATTACHMENT A Anti-Vibration Bar (AVB) Wear Indications (SG 2C)

SG Row Col Volts Per Locn lnchl SG Row Col Volts Per Locn lnchl 2C 32 73 1.13 20 AV3 0.36 2C 39 83 1.93 25 AV2 0.05 2C 21 74 1.45 21 AVl 0.66 2C 39 83 0.9 16 AV3 0.38 2C 30 74 0.94 17 AV2 0.72 2C 39 83 0.79 14 AV4 0.33 2C 30 74 1.03 18 AV3 0.06 2C 40 83 3.81 36 AV2 -0.13 2C 32 74 1.43 23 AV3 -0.36 2C 40 83 1.75 25 AV3 0 2C 19 75 1.64 22 AVl 0.14 2C 28 84 1.85 23 AV3 -0.42 2C 19 75 1.09 17 AV4 -0.37 2C 30 84 1.06 17 AV2 0.22 2C 32 79 1.07 19 AV2 -0.05 2C 37 84 1.18 18 AV2 -0.03 2C 32 79 1.86 26 AV3 -0.34 2C 37 84 1.36 19 AV3 0.05 2C 41 79 1.22 19 AV3 0 2C 41 84 1.02 16 AVl 0 2C 35 80 0.87 16 AVl -0.08 2C 41 84 0.83 14 AV2 0.05 2C 35 80 0.78 15 AV2 -0.39 2C 41 84 1.39 20 AV3 0 2C 35 80 1.19 20 AV3 -0.38 2C 26 85 1.49 21 AV2 0 2C 36 80 0.89 17 AVl -0.08 2C 30 85 1.05 18 AV2 0.29 2C 36 80 1.64 24 AV3 -0.34 2C 30 85 1.04 18 AV3 0.05 2C 36 80 0.93 18 AV4 0.56 2C 34 85 1.23 20 AV2 -0.1 2C 21 81 1.41 20 AVl 0 2C 34 85 0.83 15 AV3 0 2C 21 81 1.63 22 AV4 0 2C 35 85 1.06 18 AVl 0 2C 33 81 0.79 15 AV3 0.07 2C 35 85 2.15 27 AV2 0 2C 33 81 0.77 15 AV4 0.42 2C 35 85 3.39 34 AV3 0 2C 35 81 0.92 17 AV2 0.22 2C 41 85 0.65 13 AVl 0.13 2C 36 81 0.91 17 AV3 0 2C 41 85 1.11 19 AV3 0.07 2C 39 81 1.28 20 AV2 0 2C 42 85 1.11 19 AV3 -0.45 2C 39 81 0.95 16 AV3 -0.33 2C 31 86 1.3 19 AV3 0.14 2C 31 82 1.21 20 AV3 0.07 2C 35 86 1 16 AVl 0.11 2C 32 82 1.75 25 AV2 0.1 2C 35 86 3.36 32 AV2 -0.58 2C 35 82 1.11 19 AV2 0.1 2C 35 86 1.27 19 AV3 0.1 2C 35 82 1.59 23 AV3 -0.29 2C 42 86 1.09 17 AVl 0.05 2C 39 82 0.8 15 AV2 0.06 2C 42 86 1.92 24 AV2 0.02 2C 39 82 0.79 14 AV3 0 2C 42 86 4.15 36 AV3 0 2C 40 82 0.92 17 AV2 -0.03 2C 42 86 0.86 14 AV4 0 2C 43 82 0.66 13 AV3 -0.3 2C 25 87 0.7 14 AVl 0.08 2C 32 83 0.89 17 AVl 0 2C 35 87 0.86 16 AVl 0 2C 32 83 1.53 24 AV3 0.33 2C 35 87 1.18 19 AV3 0.21 2C 33 83 0.83 16 AVl 0.42 2C 35 87 0.72 14 AV4 0.06 2C 35 83 0.99 18 AV2 0 2C 45 87 0.61 12 AV4 -0.07 2C 35 83 1.11 19 AV3 0 2C 35 88 1.47 20 AV3 0.2 2C 39 83 0.82 15 AVl 0.14 2C 41 88 2.18 26 AV2 0.15 E2 - 35 of 40

Enclosur e 2 ATTACHMENT A Anti-Vibration Bar (AVB) Wear Indications (SG 2C)

SG Row Col Volts Per Locn lnchl SG Row Col Volts Per Locn lnchl 2C 41 88 2.9 30 AV3 0.07 2C 42 93 1.04 18 AV2 0 2C 42 88 1.63 22 AV2 0.05 2C 42 93 1.01 17 AV4 0.2 2C 42 88 1.95 24 AV3 0.05 2C 42 93 5.3 41 AV3 -0.25 2C 41 89 2.43 29 AVl -0.42 2( 34 94 1.19 18 AV2 -0.06 2C 41 89 1.75 24 AV2 -0.08 2C 34 94 0.96 15 AV3 0.14 2( 41 89 3.28 34 AV3 0.14 2C 34 94 1.11 17 AV4 0.12 2( 41 89 2.55 30 AV4 -0.36 2C 36 94 1.25 18 AV2 0 2( 42 89 1.36 21 AVl 0.08 2C 39 94 1.47 22 AV2 0 2( 42 89 3.02 33 AV2 0 2C 39 94 0.95 17 AV3 0.02 2C 42 89 4.99 41 AV3 0 2C 34 95 0.83 15 AV2 -0.39 2( 42 89 1.41 22 AV4 0.05 2C 35 95 1.16 19 AV2 -0.44 2( 22 90 1.27 19 AVl 0 2C 40 95 1.71 24 AVl -0.17 2C 27 90 0.75 13 AVl -0.35 2C 40 95 0.9 16 AV2 0 2C 30 90 1.24 18 AV2 -0.3 2C 40 95 1.84 25 AV3 -0.18 2( 40 90 0.7 12 AVl -0.15 2C 35 96 1.27 19 AV2 0 2C 40 90 1.32 19 AV2 0.05 2( 35 96 0.78 13 AV4 0.05 2C 40 90 1.05 16 AV3 0.07 2C 36 96 2.49 28 AV2 -0.03 2( 40 90 0.91 15 AV4 0.08 2( 36 96 0.68 12 AV3 0 2C 42 90 1.18 18 AVl -0.12 2C 29 98 0.64 11 AV3 -0.19 2C 42 90 1.75 23 AV2 -0.26 2C 30 98 0.84 14 AV2 -0.42 2C 42 90 3.11 31 AV3 0.07 2C 28 99 0.92 16 AVl 0 2( 42 90 1.3 19 AV4 0 2C 30 99 0.57 12 AV2 0.35 2C 27 91 0.81 15 AV3 -0.3 2C 38 99 1.19 19 AV2 0.08 2C 34 92 1.36 19 AV2 -0.18 2C 30 100 1.04 16 AV2 0.12 2( 34 92 1.26 19 AV3 0.09 2C 30 100 0.95 15 AV3 -0.17 2( 34 92 0.62 11 AV4 0.03 2C 32 100 1.16 18 AV2 0.25 2( 39 92 1.47 20 AV2 0.22 2C 32 100 0.75 13 AV3 0.08 2C 41 92 1.48 21 AVl 0.08 2C 35 100 1.21 18 AV3 0.02 2C 41 92 0.78 13 AV2 0.08 2C 27 101 0.73 14 AV3 0.17 2C 41 92 3.23 32 AV3 0.11 2C 27 101 0.8 15 AV4 0 2( 41 92 1.54 21 AV4 0.06 2C 28 101 0.8 15 AV2 0.05 2( 35 93 1.14 19 AV2 0.02 2C 28 101 0.59 12 AV3 -0.45 2C 36 93 1.3 20 AV2 0.2 2C 30 101 0.83 15 AV2 -0.32 2C 39 93 1.21 18 AV4 0.08 2C 30 101 1.02 18 AV3 -0.46 2( 40 93 1.57 23 AVl 0.23 2C 32 101 0.82 15 AV2 0.05 2( 40 93 1.09 18 AV2 -0.38 2C 32 101 0.93 16 AV3 0.05 2( 40 93 1.74 24 AV3 -0.32 2C 28 103 2.09 27 AV3 -0.03 2C 42 93 2.29 28 AVl 0 2C 32 103 0.91 16 AV3 -0.16 E2 - 36 of 40

Enclosure 2 ATTACHMENT A Anti-Vibration Bar (AVB) Wear Indications (SG 2C)

SG Row Col Volts Per Locn lnchl 2C 33 103 0.69 13 AV4 0 2C 30 104 1.33 21 AV2 0.08 2C 30 104 1.15 19 AV3 -0.49 2C 25 105 0.82 14 AV2 0.26 2C 30 105 0.8 15 AV4 -0.33 2C 25 106 1.06 17 AV1 0.24 2C 27 106 1.1 18 AV2 0.34 2C 27 106 2.83 32 AV3 0.05 2C 25 107 1.29 20 AV4 -0.17 2C 25 108 0.83 15 AVl 0.08 2C 25 108 2.92 32 AV2 -0.43 2C 25 108 2.16 27 AV3 -0.09 2C 25 108 0.55 11 AV4 0.48 E2 - 37 of 40

Enclosur e 2 ATTACHMENT A Anti-Vibration Bar (AVB) Wear Indications (SG 20)

SG Row Col Volts Per Locn lnchl SG Row Col Volts Per Locn lnchl 2D 20 5 0.55 12 AV4 0.2 2D 40 26 1.32 20 AV3 0.05 2D 23 7 1.28 19 AV3 -0.35 2D 38 27 0.69 13 AV2 0.34 2D 25 7 1.01 18 AVl 0.05 2D 39 27 0.93 16 AV2 0.08 2D 28 11 0.95 16 AV2 0.13 2D 39 27 0.85 16 AV3 0.33 2D 28 11 0.89 16 AV3 -0.38 2D 47 27 0.82 15 AV4 0.03 2D 31 13 1.11 18 AVl 0.11 2D 28 28 2.06 26 AV4 -0.46 2D 31 13 0.7 14 AV2 0.19 2D 40 28 1.26 19 AV3 -0.05 2D 31 13 1.77 24 AV3 -0.43 2D 40 29 3.26 33 AV2 -0.07 2D 31 14 1 18 AV4 0.03 2D 40 29 2.25 27 AV3 0 2D 35 14 1.39 21 AV4 -0.39 2D 42 29 1.5 21 AV2 0.22 2D 31 15 0.96 17 AV2 -0.14 2D 25 30 0.77 14 AV3 -0.2 2D 32 16 0.71 13 AV2 0.05 2D 41 32 0.61 12 AV2 0.38 2D 35 17 2.16 27 AV2 0.05 2D 41 32 1.58 23 AV3 0.53 2D 35 17 1.12 19 AV3 0.08 2D 37 33 0.58 12 AVl 0.05 2D 36 17 1.31 20 AV2 0.2 2D 37 33 3.35 34 AV2 0.49 2D 36 17 0.84 15 AV3 0.25 2D 37 33 2.81 31 AV3 0 2D 31 18 0.94 17 AV2 0.36 2D 40 33 1.42 21 AV2 0 2D 36 18 0.68 12 AV2 0.05 2D 40 33 2.34 28 AV3 0 2D 36 19 1.92 25 AV3 -0.28 2D 40 33 0.95 16 AV4 0 2D 39 19 0.88 16 AV3 0.17 2D 41 33 1.45 22 AV2 0.41 2D 35 20 1.84 25 AV2 0.16 2D 41 33 1.62 23 AV3 0.2 2D 35 20 1.01 17 AV3 0.28 2D 33 34 0.66 13 AV2 0.25 2D 41 20 1.07 18 AVl 0 2D 33 34 0.73 14 AV3 0.25 2D 41 20 2.23 28 AV2 0.11 2D 28 36 3.91 36 AV2 0.41 2D 36 21 0.96 16 AVl 0.39 2D 28 36 0.86 15 AV3 -0.37 2D 36 21 1.31 20 AV2 0.41 2D 40 36 1.23 19 AV2 0 2D 41 21 0.88 16 AV2 0.16 2D 40 36 1.25 20 AV3 0 2D 41 21 0.89 16 AV3 0.08 2D 42 36 1.14 18 AVl 0.12 2D 40 22 0.86 15 AV2 -0.29 2D 42 36 3.92 36 AV2 0 2D 40 22 1.17 18 AV3 -0.29 2D 42 36 1.72 24 AV3 0.07 2D 40 22 1.02 17 AV4 -0.34 2D 42 36 0.62 13 AV4 0.34 2D 43 22 1.58 23 AVl -0.49 2D 36 37 3.18 33 AV2 0 2D 43 22 1.81 25 AV2 0.05 2D 36 37 2.52 30 AV3 0.52 2D 43 22 1.03 18 AV3 0.11 2D 37 42 3.35 34 AV2 -0.45 2D 28 24 0.81 14 AVl -0.1 2D 37 42 1.25 20 AV3 -0.41 2D 38 25 0.74 13 AV2 0.22 2D 31 44 2.99 32 AV2 -0.03 2D 38 25 1.56 22 AV3 0.1 2D 31 44 1.48 22 AV3 0.42 2D 40 25 0.98 16 AV3 0.02 2D 41 44 0.59 12 AV3 0.33 E2 - 38 of 40

Enclosur e 2 ATTACHMENT A Anti-Vibration Bar (AVB) Wear Indications (SG 20)

SG Row Col Volts Per Locn lnchl SG Row Col Volts Per Locn lnchl 20 41 44 0.46 10 AV4 -0.31 20 28 78 0.93 16 AV3 0 20 29 45 0.67 13 AV3 0.14 20 33 78 0.82 14 AV2 -0.46 20 31 50 0.8 15 AVl 0.08 20 32 79 1.2 19 AV3 0.08 20 31 50 1.9 25 AV2 0.14 20 39 80 3.31 34 AV2 0.05 20 31 50 3.12 32 AV3 0 20 39 80 4.82 39 AV3 0.48 20 31 50 0.87 15 AV4 -0.07 20 41 80 1.83 25 AVl -0.03 20 39 52 0.66 13 AV3 0.36 20 41 80 0.61 12 AV3 0.08 20 39 52 0.55 11 AV4 0.06 20 42 80 0.49 11 AVl 0.03 20 47 56 1.1 18 AV3 0.08 20 46 80 0.95 17 AV4 0.5 20 47 56 2.17 27 AV4 0 20 19 82 0.96 18 AV4 -0.54 20 21 57 0.54 11 AVl 0.11 20 25 82 0.68 12 AV2 -0.13 20 21 57 0.92 16 AV4 -0.33 20 26 82 0.52 11 AV3 0.29 20 48 59 1.76 25 AV3 0.33 20 29 82 1.04 16 AV2 -0.03 20 48 59 0.99 18 AV4 0.03 20 36 82 2.63 30 AV2 0 20 41 60 0.95 17 AVl 0 20 36 82 1.63 23 AV3 0 20 41 60 4.5 38 AV2 0 20 36 82 1.25 20 AV4 0 20 41 60 6.65 45 AV3 0 20 37 82 1.13 19 AV2 0.11 20 36 62 0.62 11 AV2 0.19 20 37 82 0.91 16 AV4 -0.38 20 29 63 0.83 16 AV2 0.46 20 35 83 0.61 12 AV2 0.33 20 41 63 0.75 15 AVl 0.17 20 35 83 0.44 10 AV4 -0.19 20 28 65 0.95 17 AV2 0.24 20 36 83 0.94 17 AVl 0.08 20 26 70 0.86 16 AVl -0.3 20 36 83 1.69 24 AV2 0 20 26 70 2.06 26 AV2 0 20 36 83 1.01 17 AV3 0 20 26 70 1.37 21 AV3 0 20 31 84 1.59 21 AV2 0.03 20 33 70 0.78 15 AV3 0.08 20 31 84 1.69 22 AV3 -0.32 20 33 70 1.23 20 AV4 -0.43 20 31 84 1.01 16 AV4 -0.6 20 48 71 0.46 10 AVl -0.06 20 36 84 0.74 14 AV2 0 20 36 72 1.01 16 AV2 0 20 43 85 0.91 16 AV2 -0.17 20 36 72 0.53 10 AV3 0 20 43 85 0.96 16 AV3 -0.34 20 39 72 0.78 15 AVl 0.11 20 34 87 1.38 21 AV2 -0.14 20 39 72 0.96 17 AV2 0 20 34 87 1.17 19 AV3 0.14 20 39 72 1.59 23 AV3 0.33 20 34 87 0.58 12 AV4 -0.05 20 40 73 0.84 15 AVl 0.19 20 37 87 0.93 17 AV3 0.08 20 40 73 0.93 17 AV2 0 20 43 87 0.83 15 AV3 0.14 20 29 75 0.69 12 AV3 -0.34 20 34 89 0.57 12 AV3 0.08 2D 29 76 0.94 15 AV4 -0.22 2D 46 89 0.74 14 AV4 0.16 20 40 76 0.71 14 AVl 0 20 40 90 0.79 15 AV2 0 20 40 76 1.89 25 AV2 0 20 40 90 2.18 27 AV3 0 E2 - 39 of 40

Enclosure 2 ATTACHMENT A Anti-Vibration Bar (AVB) Wear Indications (SG 2D)

SG Row Col Volts Per Locn lnchl SG Row Col Volts Per Locn lnchl 2D 35 91 0.99 16 AV2 -0.49 2D 30 104 0.8 15 AV4 0.23 2D 35 91 0.61 11 AV3 0.33 2D 31 104 0.65 13 AVl -0.46 2D 43 91 0.64 13 AV4 -0.33 2D 31 104 1.22 20 AV3 0.17 2D 35 92 0.91 15 AV2 0.36 2D 26 107 1.62 23 AV3 -0.32 2D 35 92 0.99 16 AV3 0.08 2D 26 107 0.87 16 AV4 0.08 2D 40 92 0.98 17 AV3 -0.36 2D 25 108 1.54 23 AVl 0 2D 41 92 0.65 13 AV2 0 2D 25 108 1.09 18 AV2 0 2D 41 92 0.8 15 AV3 0 2D 25 108 1.46 22 AV4 0.03 2D 44 92 0.64 13 AVl 0.08 2D 36 94 0.54 11 AVl 0.24 2D 36 94 0.86 16 AV2 -0.16 2D 36 94 1.4 21 AV3 0.14 2D 22 95 0.86 15 AV4 -0.16 2D 34 95 1.2 19 AV3 0.11 2D 35 95 2.5 29 AV2 0.38 2D 35 95 0.96 17 AV3 -0.05 2D 36 95 0.92 17 AV3 -0.08 2D 34 97 1.1 17 AVl -0.06 2D 34 97 3.16 32 AV2 0.5 2D 34 97 1.04 16 AV3 0 2D 34 98 1.11 19 AV2 0 2D 34 98 1.74 24 AV3 0 2D 34 98 0.54 11 AV4 0.03 2D 31 100 0.54 11 AVl 0.08 2D 31 100 0.56 12 AV3 -0.16 2D 34 100 0.72 12 AVl 0 2D 34 100 1.37 19 AV3 0 2D 34 100 0.52 10 AV4 0.27 2D 36 100 0.81 15 AV4 -0.08 2D 28 102 1.17 19 AV3 0 2D 29 102 0.86 14 AV3 0.28 2D 34 102 0.79 15 AV4 0 2D 30 103 1.56 23 AV2 0 2D 31 103 1.82 25 AV2 0 2D 31 103 1.4 21 AV3 0.11 2D 31 103 1.66 24 AV4 0.08 2D 25 104 0.58 10 AV3 0.09 2D 30 104 1.62 23 AV2 -0.4 E2 - 40 of 40