WBL-22-018, Cycle F214 Steam Generator Tube Inspection Report

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Cycle F214 Steam Generator Tube Inspection Report
ML22087A039
Person / Time
Site: Watts Bar Tennessee Valley Authority icon.png
Issue date: 03/28/2022
From: Anthony Williams
Tennessee Valley Authority
To:
Document Control Desk, Office of Nuclear Reactor Regulation
References
WBL-22-018
Download: ML22087A039 (22)
v • d • e


Text

l TENNESSEE VALLEY*

AUTHORITY Post Office Box 2000, Spring City, Tennessee 37381 WBL-22-018 March 28, 2022 10 CFR 50.4 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555-0001 Watts Bar Nuclear Plant, Unit 2 Facility Operating License No. NPF-96 NRC Docket No. 50-391

Subject:

Watts Bar Nuclear Plant (WBN) Unit 2 - Cycle F214 Steam Generator Tube Inspection Report In accordance with the requirements of WBN Technical Specification (TS) 5.9.9, "Steam Generator Tube Inspection Report", the Enclosure provides the 180 Day Steam Generator Inspection Report for the Unit 2 Mid-Cycle outage designated F214. This report is required to be submitted within 180 days after the initial entry into MODE 4 following the completion of an inspection performed in accordance with TS 5.7.2.12, "Steam Generator (SG) Program." The report provides the complete results of the tube inspections.

There are no new regulatory commitments contained in this letter. Please direct any questions concerning this matter to Jonathan Johnson, WBN Licensing Manager, at jtjohnsonO@tva.gov.

Anthony L. Williams IV Site Vice President Watts Bar Nuclear Plant

U.S. Nuclear Regulatory Commission WBL-22-018 Page 2 March 28, 2022

Enclosure:

Watts Bar F214 180 Day Steam Generator Tube Inspection Report cc: (w/o Enclosure):

NRC Regional Administrator - Region II NRC Senior Resident Inspector - Watts Bar Nuclear Plant NRC Project Manager - Watts Bar Nuclear Plant

ENCLOSURE Tennessee Valley Authority Watts Bar Nuclear Plant Unit 2 Watts Bar F214 180 Day Steam Generator Tube Inspection Report

WESTINGHOUSE NON-PROPRIETARY CLASS 3 SG-CDMP-22-4 March2022 Revision 0 Watts Bar F214 180 Day Steam Generator Tube Inspection Report

©2022 Westinghouse Electric Company LLC All Rights Reserved

WESTfNGHOUSE NON-PROPRIETARY CLASS 3 SG-CDMP-22-4 Revision 0 Watts Bar F214 180 Day Steam Generator Tube Inspection Report Prepared for:

Tennessee Valley Authority Author's Name: Signature/ Date For Pages Mitchell D. Krinock _*.:::E:.:.;'fe::..:c:.:. 'e:.:.d,___ _ _ _ _ _ _ _~A=ll

  • f~ro:;:.:n::.:1:.:c=a:.:JI.v..:.A..:.tt"-'JPt:.r:..;o~*:....:

Component Design & Management Programs Verifier's Name: Signature/ Date For Pages Jay R. Smith -*-==E='/e=c=*t::...;ro=n=1=*ca=.l'-'-'lv(....;,.;;A""p'""1J=r-"'o..:..v=ed:=,.__ _ _ _ _ _ _ _..:.A-==ll Component Design & Management Programs Manager's Name: Signature/ Date For Pages Robert Chappo, Manager _.:*-==E:.:.;'fe::..:c:..:*t~ro:;:.:n:..:.;1:.:*c=a:.:JI.v..:.A..:.P~Pt;:.1:..;*o~"'-'e:..:d,___ _ _ _ _ _ _ _~A=ll Component Design & Management Programs Reviewer's Name: Signature/ Date For Pages Mayo, Jeremy Wayne ~~~~~b;~9: ~i';2~ ~/~;.~r V *ync Jeremy W. Mayo All TV A SG Program Manager Reviewer's Name: Signature/ Date For Pages Camp , Emmett D

  • Digitally signed by Camp, Emmett D.

Date: 2022.03.12 07:41 :49 *05'00' A [1 Emmett Camp TVA Watts Bar SG Program Engineer Reviewer's Name: Signature/ Date For Pages Daniel P. Folsom ~~\~

TV A NDE Level Ill "E/ectronic:1//y Appron*d Records are Authenticated i11 the Electro11ic Document .~lwagement System SG-CDi\,tP-22-4 March 2022 Revision 0 Page 2 of 19

Record of Revisions Revision Date Description 0-A Februarv 2022 Draft provided for Tennessee Valley Authority review and comment.

Tennessee Valley Authority's comments addressed and provided for an 0-B March2022 additional round of review and comment.

0 See PRIME Final Version Transmitted to Tennessee Valley Authority SG-CDMP-22-4 March2022 Revision 0 Page 3 of 19

Table of Contents 1.0 Introduction ............................................................................................................................................................................... 5 2.0 180 Day Sterun Generator Tube Inspection Report ................................................................................................................... 6

a. The Scope of Inspections Performed on each SG ...................................................................................................................... 6
b. Degradation Mechanisms Found ............................................................................................................................................... 7
c. Nondestructive Exrunination Techniques Utilized for Each Degradation Mechanism .............................................................. 9
d. Location, Orientation (if Linear), and Measured Sizes (if Available) of Service Induced Indications ..................................... 11
e. Number of Tubes Plugged or Repaired During the Inspection Outage for Each Degradation Mechanism .............................. 18
f. The Number and Percentage of Tubes Plugged or Repaired to Date and the Effective Plugging Percentage in each SG ........ 18
g. The Results of Condition Monitoring, Including the Results of Tube Pulls and In-Situ Testing ............................................. 19
h. Repair Method Utilized and the Number of Tubes Repaired by Each Repair Method ............................................................. 19 List of Tables and Figures Figure 1-1: Tube Support Arrangement for Watts Bar Unit 2 Model D3 Sterun Generators ............................................................. 5 Table 2-1: Watts Bar F214 Sterun Generator Eddy Current Base Inspection Progrrun Scope ............................................................ 7 Table 2-2: Watts Bar F214 Sterun Generator Eddy Current Expansion Inspection Progrrun Scope................................................... 7 Table 2-3: Number oflndications Detected for Each Degradation Mechanism during F214 ............................................................ 8 Table 2-4: NDE Techniques for Each Existing or Potential Degradation Mechanism ....................................................................... 9 Table 2-5: Watts Bar F214 Pre-Service Volumetric Indications -All SGs ..................................................................................... 11 Table 2-6: Watts Bar F214 Anti-Vibration Bar Wear Indications -All SGs ................................................................................... 12 Table 2-7: Watts Bar F214 Tube Support Plate Wear Indications - All SGs ................................................................................... 13 Table 2-8: Watts Bar F214 Foreign Object Wear Indications -All SGs .......................................................................................... 14 Table 2-9: Watts Bar F214 Axial ODSCC at TSP Indications (95-05 Excluded)-All SGs ........................................................... 14 Table 2-10: Watts Bar F214 Axial ODSCC at HTS Indications-All SGs ...................................................................................... 14 Table 2-11: Watts Bar F214 Axial PWSCC at HTS Indications - All SGs ..................................................................................... 14 Table 2-12: Watts Bar F214 Circumferential ODSCC at Freespan Dings Indications -All SGs .................................................... 14 Table 2-13: Watts Bar F214 Oblique ODSCC at TSP Paired Dings Indications -All SGs ............................................................. 14 Table 2-14: Watts Bar F214 Circumferential ODSCC at HTS Indications -All SGs ..................................................................... 15 Table 2-15: Number of Tubes Plugged for each Degradation Mechanism ...................................................................................... 18 SG-CDMP-22-4 March2022 Revision 0 Page 4 of 19

1.0 Introduction The fourth in-service inspections (ISi) of the Watts Bar Unit 2 (WBN2) steam generators (SGs) were performed during the 2021 mid-cycle inspection designated as F214. The F214 inspection was performed after 4.07 effective full power years (EFPY) of plant operation. The inspections consisted of only primary side inspections, which included eddy current testing of SG tubing and primary side visual inspections.

Secondary side activities such as top oftubesheet cleaning and foreign object search and retrieval (FOSAR) were not performed during F214 due to the short operating interval since U2R3, where secondary side activities (top oftubesheet sludge lancing and top oftubesheet FOSAR) in all SGs were performed.

This report documents the "Watts Bar F214 180-Day Steam Generator Tube Inspection Report" as required by the WBN2 Technical Specifications. The SGs at WBN2 are a Westinghouse Model D3 preheater-type design where the majority of the feedwater enters near the top of the tubesheet on the cold leg side and the tubing is made from mill annealed Alloy 600 (Alloy 600MA) material. Figure 1-1 provides the arrangement and location designation of the tube support structures for the WBN2 SGs.

Anti~ Vibration Bar<

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Figure 1-1: Tube Support Arrangement for Watts Bar Unit 2 Model D3 Steam Generators Notes: H/C/AV = Hot Leg Support/Cold Leg Support/Anti-Vibration Bar (AVB) Location HTS/CTS = Hot Leg Top ofTubesheet/Cold Leg Top ofTubesheet HTE/CTE = Hot Leg Tube End/Cold Leg Tube End SG-CDMP-22-4 March 2022 Revision 0 Page 5 of 19

2.0 180 Day Steam Generator Tube Inspection Report In accordance with WBN2 Technical Specification Section 5. 7 .2.12, "Steam Generator (SG) Program", and Technical Specification Section 5.9.9, "Steam Generator Tube Inspection Report", this report documents the scope and results of the Watts Bar F214 SG inspections. There are eight (8) specific reporting requirements associated with the Technical Specification. Each lettered reporting requirement listed below is followed with the associated information based on the inspections performed during F214.

a. The Scope oflnspections Performed on each SG The inspection program addressed the known degradation observed in the WBN2 SGs during the pre-service inspection or the first, second, and third in-service inspections as well as potential SG tube degradation mechanisms relevant to the design and material of the WBN2 SG tubing. The inspections were performed with qualified non-destructive examination (NDE) techniques for each existing and potential mechanism. The defined scope that was implemented in all four SGs included:
  • 100% bobbin inspection of all open tubes in all four SGs full length and tube Rows 1 through 4 to the top support from both the HL and the CL side.
  • 100% +POINT probe inspection of tube Rows 1 through 4 from the top support on the HL side to the top support on the CL side.
  • +POINT probe Special Interest inspections of tube locations with non-resolved bobbin and/or array probe signals.
  • +POINT probe inspection of all F214 reported DSis 2:1.0 volt.
  • +POINT probe inspection of all U2R3 reported DSis 2:0.75 volts.
  • +POINT probe Special Interest inspections of all HL and CL BLG and OXP signals
  • 100% +POINT probe inspection of the hot leg top oftubesheet region from HTS+2/-2 inches. Tubes with crevice roll depths (CRDs) required increased inspection extent into the tubesheet.
  • Array probe inspection of all cold leg peripheral tubes (two tubes deep) from C06 to CTS-2 inches.
  • 100% +POINT or array probe inspection of all DNTS 2:2 volts (HL/CL/UB).
  • 100% +POINT or array probe of all DNGS 2:5 volts in the HL straight lengths, U-bends and the top TSP on the CL side (TSP C14).
  • 50% +POINT or array probe inspection of all DNGs 2:2 volts (HL/CL/UB) .

Note: the 50% sample included all DNGs 2:2 volts not inspected in U2R2 and U2R3 resulting in a 100% inspection between the U2R3 and F214 inspections due to oversampling in U2R3.

Scope Expansion: Expanded to 100% of DNGs 2:2 volts (HL/CL/UB) in SG-3 due to detections for circumferential ODSCC at a freespan ding.

Scope Expansion: Expanded to 100% ofDNGs 2:2 volts at TSP intersections in SG-1 due to detection of an oblique ODSCC indication at paired TSP DNGs.

  • 100% +POINT probe inspection of any DNT or DNG signal located within 1.0 inch or less of an MBM.
  • +POINT or array probe inspection of tubes surrounding known locations of foreign objects.
  • +POINT or array probe inspection of all tubes within a two-tube pitch of the region surrounding any foreign object wear or PLP locations.
  • +POINT probe inspection ofSG-3 tube Row 47 Column 48 at H0l and all tubes within one tube of this location at the same elevation.
  • Array probe inspection of bobbin proximity (PRO or PRX) signals > 1.25 volts.
  • +POINT probe inspection of all pre-service VOL signals and all DFI signals.
  • 100% visual inspection of all installed tube plugs from the primary side on both the HL and CL side .
  • Visual inspection in all SGs of channel head primary side HL and CL inclusive of the entire divider plate to channel head weld and all visible clad surfaces. This included a follow-up inspection of the channel head clad anomaly in the hot leg of SG-1.

SG-CDMP-22-4 March2022 Revision 0 Page 6 of 19

The Watts Bar F214 inspection included all tubes with prior indications of degradation. Table 2-1 summarizes the number and type of eddy current examinations performed during F214 excluding the special interest inspection scope. Table 2-2 provides the expansion scope examinations performed during F214.

Table 2-1: Watts Bar F214 Steam Generator Eddy Current Base Inspection Program Scope Eddv Current Exam Tvoe SGl SG2 SG3 SG4 Full Length Bobbin 4192 4171 4087 4164 CL Rl-R4 Low Row Bobbin 448 447 451 453 HL Rl-R4 Low Row Bobbin 448 447 451 453 U-Bend +Point Rl-R4 448 447 451 453 HL +Point Tubesheet 4640 4618 4538 4617 CL Strafo:ht Leg X-Probe C06 to CTS-2 inch (Perioherv) 630 626 634 631 Axial ODSCC at TSP +Point 87 138 210 105 Dings/Dents >2 volts (+Point & X-Probe) 1168 1290 474 272 Table 2-2: Watts Bar F214 Steam Generator Eddy Current Expansion Inspection Program Scope SGl SG2 SG3 SG4 42 1 53 2

1. The ding inspection scope in SG 1 was expanded for all dings due to the detection of an oblique ODSCC indication at a paired TSP DNG
2. The ding inspection scope in SG 3 was expanded to all ding indications c::2 volts due to detection of circumferential ODSCC at a freespan ding
b. Degradation Mechanisms Found The following degradation mechanisms were detected during the F214 inspection:
  • Volumetric Indications due to Tube Fabrication and Installation (Pre-Service)
  • Mechanical Wear at Anti-Vibration Bars
  • Mechanical Wear at Tube Support Plates
  • Mechanical Wear due to Foreign Objects
  • Circumferential ODSCC at the Hot Leg Top of Tubesheet
  • Axial ODSCC at Expansion Transition and Sludge Pile
  • Axial PWSCC at Expansion Transition
  • Circumferential ODSCC at Freespan Dings
  • Oblique ODSCC at Paired TSP Dings Out of the 11 degradation mechanisms that were reported, Oblique ODSCC at Paired TSP Dings was the first detection of this specific degradation, and therefore, is now categorized as an existing degradation mechanism for WBN2. All other mechanisms were considered existing before F214.

Table 2-3 shows the number of indications reported for each degradation mechanism during the F214 inspections.

SG-CDMP-22-4 March2022 Revision 0 Page 7 of 19

Table 2-3: Number oflndications Detected for Each Degradation Mechanism during F214 De~radation Mechanism SGl SG2 SG3 SG4 Total Volumetric Indications (Pre-Service) 15 2 8 15 40 AVB Wear 7 18 6 34 65 TSP Wear 0 0 61 3 64 Foreign Object Wear 0 0 1 0 1 Axial ODSCC - TSPs (95-05) 302 436 509 336 1583 Axial ODSCC 05 Excluded 0 0 1 0 1 Circ ODSCC - HTS 39 2 54 79 174 Axial ODSCC - HTS 0 0 5 1 6 Axial PWSCC - HTS 0 1 0 1 2 Circ ODSCC - Freespan Ding 0 0 1 0 1 Oblique ODSCC - TSP Paired Dings 1 0 0 0 1 SG-CDMP-22-4 March2022 Revision 0 Page 8 of 19

c. Nondestructive Examination Techniques Utilized for Each Degradation Mechanism Table 2-4 provides the NDE techniques that were used for the detection of each degradation mechanism considered as existing or potential for the F214 inspection. NDE techniques are also listed which were available for diagnostic testing, resolution and confirmation of anomalous indications. All the examination technique specification sheets (ETSSs) used during F214 are from the electric power research institute (EPRI) database. In some cases a variable 'X' is used in the listing of techniques in Table 2-4 which is in reference to a series of ETSSs.

Table 2-4: NDE Techniques for Each Existing or Potential Degradation Mechanism Degradation Mechanism Probe ETSS Technique Existing 27091.1 Bobbin Volumetric Indications due to Tube Fabrication and Installation 27091.2

+Point 21998.1 Bobbin 96041.1

+Point 10908.4 Wear atAVBs 117908.2 Array 117908.5 Bobbin 196042.1

+Point 96910.1 Wear at Tube Support Plates 111956.1 Array 111956.2 Bobbin 128411

+Point 128431 Axial ODSCC at Tube Support Plates +Point 128424 Array 20402.1 Ghent 20407.1

+Point 128424 Ax

+Point 21410.1 Cir Axial and Circumferential ODSCC at the TTS Arrav 20400.1 Ax/Cir Ghent 20406.1 Circ

+Point 20511.1 Ax Axial PWSCC at the TIS Array 20501.1 Ax Ghent 20508.1 128411 Ax Bobbin 24013 .1 Ax 10013.1 Ax 22401.1 Ax ODSCC at Freespan Dings +Point 21410.1 Circ 128432 Ax Array 20400.1 Circ 20403 .1 Ax SG-CDMP-22-4 March 2022 Revision 0 Page 9 of 19

Dee:radation Mechanism Probe ETSS Technique Potential Bobbin 27091.1 21998.1 Wear due to Foreign Objects

+Point 27905.2 27906.2 Bobbin 13091.2 27905.2 (Flat)

+Point Tube-to-Tube Contact Wear 27906.2 (Tapered) 17905.1 Array 17905.3 Bobbin 96005.3 OD Pitting of the Tube Material +Point 21998.1 Array 24998.1

+Point II 1524 Cir

+Point 20510.1 Cir Circumferential PWSCC at the TIS Array 20500.1 Cir Ghent 20507.1 96511.2 Axial and Circumferential PWSCC in the Low Row U-bends +Point 20511.1 Ax 20510.1 Cr 128411 Ax Bobbin 10013.1 Ax 24013.1 Ax 21410.1 Cir ODSCC at Tube Dents

+Point 128431 Ax 22401.1 Cir 20400.1 Cir Array 20403.1 Ax Bobbin 96012.1 Ax

+Point 96703 .1 Ax Axial PWSCC at Dents Arrav 20500.1 Ax Ghent 20509.1 20510.1 Cr

+Point 20511.1 Ax SCC at Tube Bulges and Overexpansions II 1524 Cir Array 20500.1 Cir Arrav 20501.1 Ax 128412 Ax Bobbin 128413 Ax 128431 Ax Slud_ge Pile Axial ODSCC in the Freespan

+Point 128432 Ax Freespan 128425 Ax Array 20403 .1 Ax 22401.1 Cir 21410.1 Cir ODSCC at Dents and Dings Coincident with an MBM +Point 128431 Ax 128432 Ax Machine Burnish Marks Bobbin 96010.1 Acronym Definitions for Table 2-4

+Pt: +POINT Probe MBM: Manufacturing Burnish Mark A: Array Probe OD: Outer Diameter AVB: Anti-Vibration Bar ODSCC: Outer Diameter Stress Corrosion Cracking Ax: Axial PWSCC: Primary Water Stress Corrosion Cracking B: Bobbin Probe SCC: Stress Corrosion Cracking Cir: Circumferential TTS: Top of the Tubesheet ETSS: Eddy current Technique Specification Sheet SG-CDMP-22-4 March 2022 Revision 0 Page 10 of 19

d. Location, Orientation (if Linear), and Measured Sizes (if Available) of Service Induced Indications Table 2-5 through Table 2-14 provide a listing of all pre-service and service-induced indications reported during the F214 inspection including the estimated depths from the associated NDE technique and an indication of whether the tube has been plugged.

Implementation of Generic Letter 95-05 voltage-based alternate repair criteria (ARC) for axial ODSCC at TSP intersections excludes certain tubes and locations from application of the criteria. Indications of axial ODSCC at TSPs in excluded tube locations are identified in Table 2-9. The remaining indications of axial ODSCC at TSPs which have been addressed by GL 95-05 requirements are provided in NRC Accession Number ML21350A209.

Table 2-5: Watts Bar F214 Pre-Service Volumetric Indications-All SGs SG Row Col Location lnchl Indication 3/4TW Plu22ed?

I IO 38 Cll 41.61 VOL 21 No I IO 55 Cl3 32.88 VOL 9 No I 14 18 AVI 4.23 VOL 14 No I 14 98 Cl4 1.63 VOL 21 No I 30 73 Cl3 27.81 VOL 6 No I 31 79 Cl4 -0.58 VOL 17 No I 31 80 Cl4 1.73 VOL 24 No I 32 65 COi 2.39 VOL 11 No I 32 79 Cl4 1.04 VOL 16 No I 32 96 Cl4 0.43 VOL 28 No I 34 77 Cl4 1.49 VOL 8 No I 35 48 HOS 25 .05 VOL 22 No I 39 72 Cl3 41.26 VOL 16 No I 41 42 Cl4 0.7 VOL 25 No I 41 73 Cl4 0.62 VOL 27 No 2 5 103 H0I 0.62 VOL 12 No 2 21 16 H03 34.05 VOL 9 No 3 19 37 Cl3 2.9 VOL 16 No 3 21 41 COi 4.05 VOL 23 No 3 22 43 COi 1.45 VOL 14 No 3 32 46 H0I 4.75 VOL 28 No 3 34 72 HTS -0.59 VOL 42 Yes 3 38 42 H0I 2.4 VOL 25 Yes 1 3 38 42 H0I 1.46 VOL 13 3 38 58 H06 40.22 VOL 18 No 4 I 87 H0I 3 VOL 11 No 4 3 106 Cll 12.52 VOL 11 No 4 8 84 H04 22.43 VOL 11 No 4 9 44 H07 30.87 VOL 8 No 4 20 46 H07 22.9 VOL 7 No 4 21 31 H06 17.69 VOL 5 No 4 21 31 H06 I0.38 VOL 15 No 4 21 31 H06 2.18 VOL 8 No 4 23 77 C09 7.51 VOL 12 No 4 27 46 H04 22.73 VOL 12 No 4 28 95 H04 25 .64 VOL 9 No 4 29 100 Cl3 36.24 VOL 20 No 4 30 14 CIO 9.34 VOL 18 No 4 30 35 CIO 9.52 VOL 18 No 4 38 84 H04 3.26 VOL 5 No I - This tube was not plugged due to the VOL call, but due to GL 95-05 analysis SG-CDMP-22-4 March 2022 Revision 0 Page 11 of 19

Table 2-6: Watts Bar F214 Anti-Vibration Bar Wear Indications-All SGs SG Row Col Location Inchl Ind %TW Plu22ed?

1 35 14 AV2 0.16 PCT 13 No 1 43 54 AV2 0.15 PCT 12 No 1 43 54 AV3 0 PCT 14 No 1 40 79 AV2 0.19 PCT 11 No 1 42 90 AV3 -0.1 PCT 16 No 1 36 91 AV3 0.19 PCT 17 No 1 24 108 AV4 0.17 PCT 17 Yes 1 2 20 6 AVl -0.14 PCT 15 No 2 23 6 AV4 0 PCT 17 No 2 22 8 AV3 0.12 PCT 13 No 2 24 8 AV2 0.12 PCT 15 No 2 25 9 AV2 0.31 PCT 16 No 2 32 15 AV2 0.09 PCT IO No 2 27 21 AV4 0.16 PCT IO No 2 30 23 AV4 0.11 PCT 11 No 2 37 38 AV3 0.14 PCT 12 No 2 47 41 AVl 0.17 PCT 12 No 2 26 45 AV3 0.12 PCT 11 No 2 34 45 AV3 0.12 PCT 12 No 2 36 79 AV3 0 PCT 13 No 2 35 85 AV3 0.14 PCT 18 No 2 28 88 AV2 0 PCT 12 No 2 35 93 AV2 0.14 PCT 14 No 2 35 93 AV4 0.12 PCT 13 No 2 28 95 AVl 0 PCT 14 No 3 40 32 AV2 0 PCT IO No 3 42 64 AV3 0.14 PCT 11 No 3 46 65 AV3 0 PCT 12 No 3 43 73 AV2 0.16 PCT 18 No 3 42 93 AV4 0.04 PCT 11 No 3 30 105 AV3 -0.12 PCT IO No 4 20 5 AV4 -0.17 PCT IO No 4 20 8 AV4 -0.17 PCT 11 No 4 34 13 AV2 0.14 PCT 11 No 4 33 14 AV3 O.Q7 PCT 9 No 4 38 21 AV3 0.14 PCT 15 No 4 41 24 AV2 0.19 PCT IO No 4 41 24 AV3 0.18 PCT 14 No 4 41 27 AVl 0.02 PCT IO No 4 44 28 AV3 0.16 PCT 12 No 4 42 29 AV2 0.12 PCT 19 No 4 42 29 AV3 0.16 PCT 13 No 4 38 32 AV3 0.14 PCT 13 No 4 42 36 AV3 0 PCT 20 No 4 42 40 AV2 0.21 PCT 13 No 4 42 40 AV3 0.25 PCT 20 No 4 44 40 AV3 -0.2 PCT 8 No 4 49 59 AVl 0.12 PCT 17 No 4 49 60 AV3 0 PCT 14 No 4 49 60 AV4a -0.38 PCT IO No 4 49 60 AV4b 0.18 PCT 16 No 4 42 64 AVl 0 PCT IO No 4 42 65 AV2 -0.17 PCT 24 No 4 42 65 AV3 0.19 PCT 15 No 4 35 68 AV2 0 PCT IO No 4 41 74 AV3 0.24 PCT 17 No 4 46 75 AV3 0.05 PCT 8 No 4 42 78 AV3 -0.05 PCT IO No 4 44 78 AV3 -0.02 PCT IO No 4 28 79 AV3 0.17 PCT 7 No 4 29 79 AV3 0.19 PCT 8 No 4 41 88 AV3 0.14 PCT 11 No 4 29 90 AVl 0.39 PCT 13 No 4 41 90 AV4 -0.02 PCT 8 No 4 41 94 AV3 0.14 PCT 12 No 1- This tube was not plugged due to the PCT call, but under GL 95-05 analysis.

SG-CDMP-22-4 March 2022 Revision 0 Page 12 of 19

Table 2-7: Watts Bar F214 Tube Support Plate Wear Indications-All SGs SG Row Col Locn Inchl Ind %TW Plu22ed?

3 41 50 C06 -0.14 PCT 4 No 3 45 49 cos -0.21 PCT 5 No 3 46 53 C06 -0.24 PCT 5 No 3 46 65 cos 0 PCT 8 No 3 48 58 C06 -0.21 PCT 4 No 3 48 59 C06 -0.21 PCT 4 No 3 48 62 cos -0.02 PCT 4 No 3 48 63 C03 0 PCT 3 No 3 48 65 C06 0 PCT 3 No 3 49 55 cos 0.02 PCT 7 No 3 49 58 cos 0.02 PCT 10 No 3 49 60 cos 0.02 PCT 10 No 3 45 63 C06 -0.24 PCT 4 No 3 46 56 cos 0.02 PCT 5 No 3 46 56 C06 -0.17 PCT 9 No 3 46 57 C06 0 PCT 6 No 3 46 58 C06 -0.19 PCT 8 No 3 46 59 cos -0.28 PCT 5 No 3 46 60 C06 -0.19 PCT 4 No 3 46 61 cos 0.09 PCT 13 No 3 46 61 C06 -0.17 PCT 4 No 3 46 65 C06 -0.19 PCT 10 No 3 47 56 C06 -0.24 PCT 7 No 3 47 57 C06 -0.21 PCT 6 No 3 47 58 cos 0.43 VOL 30 No 3 47 59 CO2 -0.02 PCT 7 No 3 47 59 cos 0.05 PCT 14 No 3 47 59 C06 -0.28 PCT 3 No 3 47 60 C03 0.02 PCT 4 No 3 47 60 C06 -0.16 PCT 26 No 3 47 62 C06 -0.12 PCT 7 No 3 47 63 cos -0.05 PCT 23 No 3 47 63 C06 -0.12 PCT 7 No 3 47 64 cos -0.02 PCT 7 No 3 47 64 C06 -0.24 PCT 10 No 3 47 65 cos 0 PCT 14 No 3 48 51 C06 0.44 PCT 4 No 3 48 53 cos -0.28 PCT 6 No 3 48 55 cos -0.28 PCT 3 No 3 48 55 C06 -0.17 PCT 3 No 3 48 56 cos 0 PCT 6 No 3 48 56 C06 0.09 PCT 9 No 3 48 58 C03 0.05 PCT 5 No 3 48 58 cos -0.02 PCT 9 No 3 48 60 cos 0 PCT 12 No 3 48 60 C06 -0.19 PCT 27 No 3 48 61 CO2 0.14 PCT 14 No 3 48 61 cos 0.02 PCT 20 No 3 48 61 C06 -0.19 PCT 7 No 3 48 63 cos -0.19 PCT 7 No 3 48 63 C06 -0.09 PCT 4 No 3 48 64 cos 0 PCT 29 No 3 48 64 C06 -0.21 PCT 13 No 3 48 65 cos 0.05 PCT 33 No 3 48 66 cos -0.19 PCT 6 No 3 48 66 C06 -0.21 PCT 22 No 3 49 59 cos 0.21 PCT 8 No 3 49 59 C06 -0.31 PCT 8 No 3 49 60 CO2 0 PCT 6 No 3 49 60 C06 -0.21 PCT 21 No 3 49 61 C06 -0.21 PCT 16 No 4 48 46 C06 -0.24 PCT 9 No 4 48 77 cos 0.32 PCT 8 No 4 49 74 C06 -0.12 PCT 5 No SG-CDMP-22-4 March2022 Revision 0 Page 13 of 19

Table 2-8: Watts Bar F214 Foreign Object Wear Indications -All SGs SG Row Col Location lnchl Ind %TW Plugged 3 49 66 C06 -1.34 SVI 23 Yes Table 2-9: Watts Bar F214 Axial ODSCC at TSP Indications (95-05 Excluded) -All SGs Max. Total Structural Structural SG Row Col Volt Deg Ind Locn lnchl Depth Length, Effective Effective Plugged

%TW inch Depth,%TW Len2th, inch 3 49 84 0.16 60 SAi H05 -0.07 47.6 0.19 37.7 0.132 Yes Note: The remaining indications of Axial ODSCC at TSP indications which have been addressed bv GL 95-05 are orovided in ML21350A209 Table 2-10: Watts Bar F214 Axial ODSCC at HTS Indications -All SGs Structural Structural Max.Depth, Total Length, SG Row Col Volt Deg Ind Locn Inchl Effective Effective Plugged

%TW inch Depth %TW Len2th inch 3 22 54 0.34 102 SAi HTS 0.17 60 0.42 54.9 0.281 Yes 3 22 63 0.22 80 SAi HTS 0.22 52.8 0.13 47.6 0.108 Yes 3 23 64 0.24 92 SAi HTS 0.42 53.9 0.31 50 0.246 Yes 3 24 60 0.59 92 SAi HTS 0.28 68.1 0.49 54.4 0.419 Yes 3 26 61 0.21 89 SAi HTS 0.69 51.3 0.52 45.8 0.458 Yes 4 19 67 0.78 46 SAi HTS 0.04 73.8 0.14 61 0.106 Yes Table 2-11: Watts Bar F214 Axial PWSCC at HTS Indications -All SGs Max. Structural Max.Depth, Total Structural Depth, Effective SG Row Col Volt Deg Ind Locn Inchl Amplitude, Length, Effective Plugged Phase Length,

%TW inch Depth, %TW

%TW inch 2 27 64 1.44 29 SAi HTS -1.89 97 64.2 0.25 89.8 0.208 Yes 4 21 68 0.95 47 SAi HTS -0.06 99 53.1 0.14 86.3 0.111 Yes Table 2-12: Watts Bar F214 Circumferential ODSCC at Freespan Dings Indications -All SGs Max. FlawCirc Ding Circ Bobbin SG Row Col Volt Ind Locn Inchl Depth PDA Extent, Stabilizer Plugged Extent,Deg DingVpp

%TW Dee 3 13 57 0.52 SCI H07 17.93 65 10.0 44.6 55.4 6.22 HL Yes Table 2-13: Watts Bar F214 Oblique ODSCC at TSP Paired Dings Indications -All SGs Max. Total Structural Structural SG Row Col Volt Ind Locn Inchl Depth,% Length, Effective Effective Stabilizer Plugged TW inch Depth, %TW Lenl!th, inch 1 1 4 0.69 SOI H03 0.11 71.8 0.94 61.7 0.58 HL Yes Note: The Obliaue ODSCC was measured bv line-bv-line deoth orofiling using ETSS 128431 with adiustments for the obliaue angle.

SG-CDMP-22-4 March2022 Revision 0 Page 14 of 19

Table 2-14: Watts Bar F214 Circumferential ODSCC at HTS Indications -All SGs Indication Summarv Resolution Sizine Deoth Profiline Sizine Max Segment Max Segment Depth Max Depth SG Row Col Ind Locn Inchl Depth, Arc, PDA Depth, Arc, Profile Plugged Vpp Profiled

%TW Dee. %TW Dee. PDA 1 7 19 SCI HTS -0.15 0.2 54 103.1 18.0 - - - - Yes 1 7 50 SCI HTS -0.07 0.23 0 46.2 11.0 - - - - Yes 1 8 62 SCI HTS -0.07 0.22 0 189.2 21.8 y 48 197 24.77 Yes 1 11 34 SCI HTS -0.06 0.12 7 24.6 9.4 - - - - Yes 1 13 19 SCI HTS -0.04 0.22 1 133.8 17.6 - - - - Yes 1 14 25 SCI HTS -0.1 0.18 55 66.2 14.4 - - - - Yes 1 18 108 SCI HTS -0.06 0.15 40 90.8 14.4 - - - - Yes 1 19 88 SCI HTS -0.05 0.16 73 175.4 31.7 y 79 174 23.61 Yes 1 20 13 SCI HTS -0.07 0.17 48 158.5 21.9 - - - - Yes 1 22 32 SCI HTS -0.06 0.17 37 35.4 10.2 - - - - Yes 1 22 49 SCI HTS -0.48 0.17 0 158.5 19.5 - - - - Yes 1 24 18 SCI HTS -0.07 0.24 0 118.5 16.5 - - - - Yes 1 24 20 SCI HTS -0.07 0.24 0 170.8 20.4 - - - - Yes 1 24 27 SCI HTS -0.08 0.27 17 106.2 15.5 - - - - Yes 1 24 76 SCI HTS -0.07 0.22 65 167.7 28.1 y 67 223 34.08 Yes 1 25 15 SCI HTS -0.06 0.16 50 76.9 14.8 - - - - Yes 1 25 45 SCI HTS -0.09 0.3 54 175.4 25.4 y 64 123 17.76 Yes 1 26 41 SCI HTS -0.07 0.19 48 24.6 9.7 - - - - Yes 1 28 38 SCI HTS -0.08 0.11 0 92.3 14.5 - - - - Yes 1 32 22 SCI HTS -0.1 0.14 32 63.1 12.3 - - - - Yes 1 34 22 SCI HTS -0.07 0.18 51 147.7 21.7 - - - - Yes 1 34 24 SCI HTS -0.04 0.2 35 86.2 14.0 - - - - Yes 1 41 24 SCI HTS -0.05 0.15 66 60 15.0 - - - - Yes 1 41 34 SCI HTS -0.05 0.34 0 240 25.7 y 42 141 16.37 Yes 1 42 38 SCI HTS -0.07 0.14 0 95.4 14.7 - - - - Yes 1 42 62 SCI HTS -0.11 0.12 0 144.6 18.4 - - - - Yes 1 42 72 SCI HTS -0.12 0.17 51 49.2 12.2 - - - - Yes 1 42 77 SCI HTS -0.07 0.16 30 53.8 11.6 - - - - Yes 1 44 27 SCI HTS -0.04 0.24 0 64.6 12.4 - - - - Yes 1 44 28 SCI HTS -0.1 0.28 0 89.2 14.2 - - - - Yes 1 44 32 SCI HTS -0.1 0.2 0 80 13.5 - - - - Yes 1 44 76 SCI HTS -0.07 0.14 37 53.8 11.6 - - - - Yes 1 46 30 SCI HTS -0.05 0.17 57 209.2 30.1 y 99 131 30.73 Yes 1 46 34 SCI HTS -0.04 0.2 0 101.5 15.2 - - - - Yes 1 46 38 SCI HTS -0.07 0.17 46 56.9 12.4 - - - - Yes 1 46 54 SCI HTS -0.1 0.27 0 169.2 20.3 - - - - Yes 1 46 73 SCI HTS -0.07 0.25 86 135.4 29.5 y 80 150 21.54 Yes 1 47 29 SCI HTS -0.1 0.36 0 166.2 20.1 y 85 158 27.68 Yes 1 47 42 SCI HTS -0.05 0.3 0 164.6 20.0 - - - - Yes 2 31 88 SCI HTS -0.07 0.16 26 109.2 15.8 - - - - Yes 2 45 59 SCI HTS -0.14 0.18 45 40 10.9 - - - - Yes 3 1 45 MCI HTS -0.09 0.19 0 215.4 23.8 - - - - Yes 3 4 20 SCI HTS -0.09 0.18 0 86.7 14.1 - - - - Yes 3 4 90 SCI HTS -0.08 0.2 7 40 10.5 - - - - Yes 3 6 5 SCI HTS -0.09 0.09 52 55.7 13.0 - - - - Yes 3 8 24 SCI HTS -0.08 0.13 64 30 11.1 - - - - Yes 3 8 51 SCI HTS -0.11 0.16 14 53.8 11.6 - - - - Yes 3 9 63 SCI HTS -0.1 0.23 37 41.5 10.6 - - - - Yes 3 9 90 SCI HTS -0.13 0.14 72 170.8 30.8 y 79 158 20.81 Yes 3 11 6 SCI HTS -0.03 0.15 25 67.7 12.6 - - - - Yes 3 11 7 SCI HTS -0.08 0.19 19 264.6 27.5 y 82 204 27.82 Yes 3 11 63 SCI HTS -0.1 0.23 55 27.7 10.4 - - - - Yes 3 12 99 SCI HTS -0.14 0.27 0 124.6 16.9 - - - - Yes 3 12 101 SCI HTS -0.13 0.21 31 212.3 23.6 - - - - Yes 3 12 103 SCI HTS -0.09 0.16 0 63 12.3 - - - - Yes 3 13 49 SCI HTS -0.11 0.24 54 155.4 23.4 - - - - Yes 3 13 96 SCI HTS -0.12 0.16 16 67.7 12.6 - - - - Yes 3 13 99 SCI HTS -0.09 0.13 23 100 15.1 - - - - Yes 3 13 101 SCI HTS -0.11 0.12 60 55 13.7 - - - - Yes SG-CDMP-22-4 March2022 Revision 0 Page 15 of 19

Indication Summary Resolution Sizine Depth Profiline Sizine Max Segment Max Segment Depth Max Depth SG Row Col Ind Locn Inchl Depth, Arc, PDA Depth, Arc, Profile Plugged Vpp Profiled

%TW De!!. %TW De!!. PDA 3 13 104 SCI HTS -0.09 0.16 24 204.6 23.0 - - - - Yes 3 14 6 SCI HTS -0.09 0.19 7 38.5 10.4 - - - - Yes 3 14 22 SCI HTS -0.08 0.28 53 75.4 15.1 - - - - Yes 3 14 49 SCI HTS -0.17 0.17 0 46.2 11.0 - - - - Yes 3 14 94 SCI HTS -0.11 0.23 0 175.4 20.8 - - - - Yes 3 15 18 SCI HTS -0.07 0.33 0 310.8 31.0 y 83 311 42.31 Yes 3 15 61 SCI HTS -0.08 0.16 53 116.9 19.2 - - - - Yes 3 17 15 SCI HTS -0.12 0.15 31 181.5 21.2 - - - - Yes 3 18 18 SCI HTS -0.06 0.16 1 64.6 12.4 - - - - Yes 3 19 11 SCI HTS -0.06 0.16 81 80 19.8 y 69 101 17.05 Yes 3 21 93 SCI HTS -0.08 0.11 71 63.1 16.0 - - - - Yes 3 22 39 SCI HTS -0.09 0.24 0 110.8 15.9 - - - - Yes 3 22 58 SCI HTS -0.15 0.21 81 187.7 36.3 y 83 160 22.66 Yes 3 23 51 SCI HTS -0.39 0.18 32 55.4 11.7 - - - - Yes 3 24 22 SCI HTS -0.08 0.35 0 147.7 18.7 y 81 135 20.16 Yes 3 24 93 SCI HTS -0.11 0.17 48 147.7 20.9 - - - - Yes 3 26 26 SCI HTS -0.12 0.14 1 75.4 13.2 - - - - Yes 3 26 31 SCI HTS -0.08 0.16 67 72.2 16.6 - - - - Yes 3 26 59 SCI HTS -0.06 0.35 84 136.9 29.3 y 93 148 36.44 Yes 3 26 99 SCI HTS -0.06 0.28 24 207.7 23.2 - - - - Yes 3 29 58 SCI HTS -0.05 0.11 55 30.8 10.7 - - - - Yes 3 31 25 SCI HTS -0.09 0.09 48 33.8 10.6 - - - - Yes 3 31 64 SCI HTS -0.07 0.22 37 70.8 12.9 - - - - Yes 3 31 66 SCI HTS -0.1 0.13 17 67.7 12.6 - - - - Yes 3 31 99 SCI HTS -0.11 0.27 39 187 21.6 - - - - Yes 3 33 53 SCI HTS -0.11 0.09 20 27.7 9.6 - - - - Yes 3 34 27 SCI HTS -0.09 0.11 91 32.3 13.1 y 92 73 15.03 Yes 3 36 43 SCI HTS -0.12 0.14 48 123.1 18.7 - - - - Yes 3 42 35 SCI HTS -0.13 0.08 81 196.9 37.7 y 44 142 17.83 Yes 3 45 31 SCI HTS -0.07 0.14 42 33.8 10.2 - - - - Yes 3 45 43 SCI HTS -0.06 0.16 37 60 12.0 - - - - Yes 3 46 64 SCI HTS -0.09 0.18 31 110.8 15.9 - - - - Yes 3 47 82 MCI HTS -0.08 0.28 36 81.5 13.7 - - - - Yes 3 49 41 SCI HTS -0.01 0.16 24 33.8 10.0 - - - - Yes 3 49 54 SCI HTS -0.08 0.09 29 96.9 14.8 - - - - Yes 3 49 66 SCI HTS -0.05 0.14 0 107.7 15.6 - - - - Yes 4 3 3 SCI HTS -0.06 0.24 75 66.2 16.9 - - - - Yes 4 3 9 SCI HTS -0.1 0.24 45 147.7 20.1 - - - - Yes 4 5 26 SCI HTS -0.09 0.23 0 89.2 14.2 - - - - Yes 4 5 68 MCI HTS -0.07 0.16 8 126.2 17.0 - - - - Yes 4 5 75 SCI HTS -0.04 0.27 13 160 19.6 - - - - Yes 4 5 82 SCI HTS -0.15 0.29 65 103.1 20.2 - - - - Yes 4 5 86 SCI HTS -0.01 0.1 74 47.7 14.2 - - - - Yes 4 5 107 MCI HTS -0.05 0.17 21 175.4 20.8 - - - - Yes 4 6 68 MCI HTS -0.1 0.16 0 138.5 18.0 - - - - Yes 4 6 73 MCI HTS -0.11 0.14 65 178.5 29.5 - - - - Yes 4 6 105 SCI HTS -0.07 0.19 0 50.8 11.3 - - - - Yes 4 7 33 SCI HTS -0.11 0.15 0 44.6 10.9 - - - - Yes 4 7 67 SCI HTS -0.06 0.23 0 47.7 11.1 - - - - Yes 4 7 105 MCI HTS -0.09 0.17 0 227.7 24.7 y 40 206 23.72 Yes 4 9 97 SCI HTS -0.09 0.25 80 110.8 24.3 y 82 119 26.75 Yes 4 10 50 SCI HTS -0.1 0.35 0 110.8 15.9 - - - - Yes 4 10 64 SCI HTS -0.1 0.23 16 112.3 16.0 - - - - Yes 4 10 65 SCI HTS -0.07 0.23 38 156.9 19.4 - - - - Yes 4 10 67 SCI HTS -0.04 0.21 42 166.2 20.7 - - - - Yes 4 10 77 SCI HTS -0.03 0.36 11 164.6 20.0 y 97 177 31.02 Yes 4 10 79 MCI HTS -0.07 0.25 42 152.3 19.6 - - - - Yes 4 10 88 SCI HTS -0.07 0.36 32 84.6 13.9 - - - - Yes 4 11 89 SCI HTS -0.03 0.17 0 167.7 20.2 - - - - Yes 4 11 100 SCI HTS -0.06 0.21 57 115.4 19.9 - - - - Yes 4 12 44 SCI HTS 0.02 0.27 50 116.9 18.6 - - - - Yes SG-CDMP-22-4 March2022 Revision 0 Page 16 of 19

Indication Summary Resolution Sizine Depth Profiline Sizine Max Segment Max Segment Depth Max Depth SG Row Col Ind Locn Inchl Depth, Arc, PDA Depth, Arc, Profile Plugged Vpp Profiled

%TW De!!. %TW De!!. PDA 4 12 70 SCI HTS -0.07 0.22 76 50.8 14.8 - - - - Yes 4 12 88 SCI HTS -0.08 0.18 30 80 13.5 - - - - Yes 4 13 85 SCI HTS -0.08 0.17 0 53.8 11.6 - - - - Yes 4 14 50 SCI HTS -0.13 0.31 45 146.2 19.9 - - - - Yes 4 14 95 SCI HTS -0.03 0.31 47 195.4 24.9 y 73 128 18.81 Yes 4 15 66 SCI HTS -0.16 0.16 8 73.8 13.1 - - - - Yes 4 15 67 SCI HTS -0.07 0.28 59 130.8 22.1 - - - - Yes 4 15 95 SCI HTS -0.05 0.45 21 206.2 23.1 y 45 187 22.48 Yes 4 15 99 MCI HTS -0.08 0.36 21 267.7 27.8 y 86 272 42.71 Yes 4 15 101 MCI HTS -0.09 0.21 21 215.4 23.8 y 94 253 39.21 Yes 4 15 103 MCI HTS -0.05 0.35 36 260 27.2 y 94 280 40.33 Yes 4 16 54 SCI HTS -0.07 0.31 0 110.8 15.9 - - - - Yes 4 16 58 SCI HTS -0.04 0.25 9 104.6 15.4 - - - - Yes 4 16 64 SCI HTS -0.1 0.25 94 84.6 22.5 y 96 41 10.27 Yes 4 16 68 SCI HTS -0.07 0.35 0 167.7 20.2 - - - - Yes 4 16 73 SCI HTS -0.13 0.26 0 178.5 21.0 - - - - Yes 4 16 77 SCI HTS -0.07 0.21 0 166.2 20.1 - - - - Yes 4 16 78 SCI HTS -0.09 0.25 40 112.3 16.0 - - - - Yes 4 16 88 MCI HTS -0.11 0.29 45 150.8 20.3 - - - - Yes 4 16 91 SCI HTS -0.03 0.26 3 106.2 15.5 - - - - Yes 4 16 101 SCI HTS -0.09 0.35 19 232.3 25.1 y 94 162 29.2 Yes 4 16 106 SCI HTS -0.08 0.36 0 156.9 19.4 y 68 204 30.26 Yes 4 18 54 SCI HTS -0.12 0.31 0 155.4 19.3 - - - - Yes 4 18 60 SCI HTS -0.09 0.27 74 136.9 26.7 - - - - Yes 4 18 88 MCI HTS -0.1 0.19 45 169.2 21.9 - - - - Yes 4 19 70 SCI HTS -0.12 0.3 84 213.8 41.5 y 96 234 43.09 Yes 4 19 79 SCI HTS -0.12 0.24 0 154.8 19.2 - - - - Yes 4 20 13 SCI HTS -0.14 0.14 0 41.5 10.6 - - - - Yes 4 20 69 SCI HTS -0.1 0.23 21 216.9 23.9 y 98 165 40.54 Yes 4 21 52 SCI HTS -0.24 0.18 48 101.5 16.7 - - - - Yes 4 21 53 SCI HTS -0.2 0.29 42 115.4 16.7 - - - - Yes 4 22 48 SCI HTS -0.21 0.25 73 40 13.0 - - - - Yes 4 22 60 SCI HTS -0.21 0.23 71 66.2 16.4 - - - - Yes 4 22 68 SCI HTS -0.34 0.29 13 126.2 17.0 - - - - Yes 4 23 95 SCI HTS -0.09 0.19 37 60 12.0 - - - - Yes 4 24 25 SCI HTS -0.07 0.2 0 180 21.1 - - - - Yes 4 24 26 SCI HTS -0.15 0.1 0 43.1 10.8 - - - - Yes 4 24 93 SCI HTS -0.05 0.21 41 116.9 16.6 - - - - Yes 4 25 66 SCI HTS -0.46 0.29 25 66.2 12.5 - - - - Yes 4 27 64 MCI HTS -0.11 0.24 74 193.8 34.6 y 83 118 18.39 Yes 4 28 94 SCI HTS -0.09 0.16 40 146.2 18.6 - - - - Yes 4 29 47 SCI HTS -0.09 0.25 80 141.5 28.9 y 98 171 42.37 Yes 4 31 29 SCI HTS -0.1 0.2 0 100 15.1 - - - - Yes 4 33 56 SCI HTS -0.12 0.23 29 66.2 12.5 - - - - Yes 4 33 73 SCI HTS -0.13 0.26 5 110.8 15.9 - - - - Yes 4 34 26 SCI HTS -0.16 0.25 0 86.2 14.0 - - - - Yes 4 34 87 SCI HTS -0.09 0.15 78 61.5 16.6 - - - - Yes 4 38 65 MCI HTS -0.1 0.23 36 181.5 21.2 - - - - Yes 4 41 61 SCI HTS -0.07 0.35 68 173.8 29.9 - - - - Yes 4 42 27 SCI HTS -0.15 0.16 43 150.8 19.8 - - - - Yes 4 45 32 SCI HTS -0.08 0.27 0 218.5 24.0 y 57 244 37.66 Yes 4 45 72 SCI HTS -0.09 0.23 43 75.4 13.6 - - - - Yes 4 46 49 SCI HTS -0.1 0.18 45 155.4 20.7 - - - - Yes 4 49 43 SCI HTS -0.06 0.2 3 38.5 10.4 - - - - Yes SG-CDMP-22-4 March2022 Revision 0 Page 17 of 19

e. Number of Tubes Plugged or Repaired During the Inspection Outage for Each Degradation Mechanism There were 384 tubes plugged during the Watts Bar F214 SG in-service inspection. The only degradation mechanisms detected during F214 that did not require plugging were AVB wear and TSP wear. It is noted that Axial ODSCC at Freespan dings is an existing degradation mechanism for Watts Bar Unit 2, but was not detected during F214. Table 2-15 provides the numbers and percentages of tubes plugged following F214.

Table 2-15: Number of Tubes Plugged for each Degradation Mechanism SGl SG2 SG3 SG4 Total Plu11:11:ed Tubes prior to F214 34 56 136 57 283 Plu22im! Reason Tubes Plu22ed durin2 F214 Volumetric Indications (Pre-Service) 0 0 1 0 1 AVB Wear 0 0 0 0 0 TSP Wear 0 0 0 0 0 Foreil!D Object Wear / Box-in 0 0 61 0 6 Possible Loose Part (PLP) 0 0 0 2 2 Axial ODSCC - TSPs (95-05) 28 41 104 32 205 Axial ODSCC - TSPs (95-05 Excluded) 0 0 1 0 1 Circ ODSCC - HTS 37 2 46 1 76 160 Axial ODSCC - HTS 0 0 4 1 5 Volumetric Indication in Tubesheet F* Region 0 1 0 1 2 Axial ODSCC - Freespan Dings 0 0 0 0 0 Circ ODSCC - Freespan Dings 0 0 1 0 1 Oblique ODSCC - TSP Paired Dings 1 0 0 0 1 Total Plugged Following F214 100 100 298 169 667 Percenta11:e Plu1:ri!ed Followinl! F214 2.14% 2.14% 6.38% 3.62% 3.57%

1 - R49C66 in SG 3 had both Foreign Object Wear and a Circ ODSCC indication on the HTS. This is counted in their respective plugging reason populations but is only counted once in the total amount of plugs following F214 in SG 3.

One of the tubes plugged in SG3 was a volumetric indication newly reported during F214 but observable in eddy current data history back to the pre-service inspection. The remaining tubes were plugged due to indications of foreign object wear, possible loose parts (PLPs), and cracking degradation which are plugged in accordance with the requirements of the Watts Bar Unit 2 Technical Specifications. There were no tubes repaired by sleeving during the Watts Bar F214 SG inspections.

f. The Number and Percentage of Tubes Plugged or Repaired to Date and the Effective Plugging Percentage in each SG Table 2-15 in the previous section provides the number and percentage of tubes plugged to date.

SG-CDMP-22-4 March 2022 Revision 0 Page 18 of 19

g. The Results of Condition Monitoring, Including the Results of Tube Pulls and In-Situ Testing Condition Monitoring, Tube Pulls and In-Situ Testing A condition monitoring (CM) assessment was performed as required by the WBN2 SG program. Based on the WBN2 F214 inspection data, all tubes with observed degradation satisfied the condition monitoring criteria for structural and leakage integrity. The WBN2 Generic Letter (GL) 95-05 Voltage-Based alternate repair criteria final report is provided separately in ML21350A209. This report provides an evaluation of axial ODSCC indications at TSP locations against the GL 95-05.

Operational leakage integrity was demonstrated by the absence of any detectable primary-to-secondary leakage during the operating interval prior to F214. Since tube integrity was demonstrated analytically, in-situ pressure testing was not required nor performed during the F214 outage. No tube pulls were planned or performed during F214.

Primary Visual Inspection Results Visual inspections were performed on only the primary side during F214 in all four SGs. Primary side inspections performed in accordance with Westinghouse Nuclear Safety Advisory Letter NSAL-12-1, Revision 1 included the hot leg and cold leg divider plate, inclusive of the divider plate-to-channel head weld, and all visible clad surfaces of the SG channel head. The NSAL-12-1 examinations performed during U2Rl showed visually apparent evidence of minor indications of degradation of the cladding in SG I located on the hot leg side just above the primary manway opening. The indications were re-inspected during F214 and showed that the indications were consistent with prior inspections with no apparent changes in anomaly size, shape or character. The conclusion of the engineering evaluation performed after U2Rl was that acceptable margin exists for maintenance of structural integrity of the SG channel head base metal for at least six cycles of operation. This conclusion was considered to remain applicable following the F214 inspection. No new indications were reported from the visual examinations of the channel head cladding.

All previously installed tube plugs were visually inspected from the primary side in all four SGs. The inspection results were satisfactory and showed no indication of tube plug leakage or failure.

h. Repair Method Utilized and the Number of Tubes Repaired by Each Repair Method No tubes have been repaired by sleeving at WBN2 to date.

SG-CDMP-22-4 March2022 Revision 0 Page 19 of 19

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