ML15050A041

End of Cycle 16 Steam Generator Tube Inspection Report

ML15050A041
Person / Time
Site:	Millstone
Issue date:	02/09/2015
From:	Daugherty J Dominion, Dominion Nuclear Connecticut
To:	Document Control Desk, Office of Nuclear Reactor Regulation
Shared Package
ML15050A041	List: ML15050A041
References
15-005
Download: ML15050A041 (22)

Text

Dominion Nuclear Connecticut, Inc. Domnion Rope Ferry Rd., Waterford, CT 06385 Mailing Address: P.O. Box 128 Warerford, CT 06385 dom.orn FEB"0 9 2015 U.S. Nuclear Regulatory Commission Serial No.15-005 Attention: Document Control Desk NSS&L/MLC RO Washington, DC 20555 Docket No. 50-423 License No. NPF-49 DOMINION NUCLEAR CONNECTICUT, INC.

MILLSTONE POWER STATION UNIT 3 END OF CYCLE 16 STEAM GENERATOR TUBE INSPECTION REPORT In accordance with the Millstone Power Station Unit 3 Technical Specification (TS)

Section 6.9.1.7, Dominion Nuclear Connecticut, Inc. hereby submits the End of Cycle 16 (EOC16) Steam Generator (SG) Tube Inspection report. The report is submitted within 180 days after initial entry into MODE 4 following completion of the fall 2014 SG inspections performed in accordance with TS 6.8.4.g, "Steam Generator (SG) Program."

Initial entry into Mode 4 occurred on November 13, 2014.

Enclosure 1 contains the EOC16 SG Tube Inspection report. Enclosure 2 contains a list of acronyms.

The report addresses the following reporting requirements:

a. The scope of inspections performed on each SG,

b. Degradation mechanisms found,

c. Nondestructive examination techniques utilized for each degradation mechanism,

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

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

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

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

h. The primary to secondary LEAKAGE rate observed in each SG (if it is not practical to assign the LEAKAGE to an individual SG, the entire primary to secondary LEAKAGE should be conservatively assumed to be from one SG) during the cycle preceding the inspection which is the subject of the report,

i. The calculated accident induced leakage rate from the portion of the tubes below 15.2 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 2.49 times the maximum operational primary to secondary leakage rate, the report should describe how it was determined; and V"/'

te 4

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Serial No.15-005 Docket No. 50-423 Page 2 of 2

j. The results of monitoring for tube axial displacement (slippage). If slippage is discovered, the implications of the discovery and corrective action shall be provided.

If you have any questions or require additional information, please contact Mr. William D.

Bartron at (860) 444-4301.

Sincerely, J. R augherty Site Vice President - Millstone

Enclosures:

1) Millstone Power Station Unit 3, End of Cycle 16 Steam Generator Tube Inspection Report

2) Acronyms Commitments made in this letter: None cc: U.S. Nuclear Regulatory Commission Region I 2100 Renaissance Blvd, Suite 100 King of Prussia, PA 19406-2713 M. C. Thadani NRC Senior Project Manager U.S. Nuclear Regulatory Commission One White Flint North, Mail Stop 08 B1 11555 Rockville Pike Rockville, MD 20852-2738 NRC Senior Resident Inspector Millstone Power Station

Serial No.15-005 Docket No. 50-423 ENCLOSURE 1 Millstone Power Station Unit 3 End of Cycle 16 Steam Generator Tube Inspection Report MILLSTONE POWER STATION UNIT 3 DOMINION NUCLEAR CONNECTICUT, INC.

Serial No.15-005 Docket No. 50-423 Enclosure 1, Page 1 of 17 End of Cycle 16 Steam Generator Tube Inspection Report Transmittal of this report satisfies Millstone Power Station Unit 3 (MPS3) Technical Specification (TS) 6.9.1.7 which specifies that a report shall be submitted within 180 days after the initial entry into MODE 4 following completion of an inspection performed in accordance with TS 6.8.4.g, Steam Generator (SG) Program. During the MPS3 fall 2014 refueling outage (3R16), steam generator inspections were completed in accordance with (TS) Section 6.8.4.g. Initial entry into Mode 4 occurred on November 13, 2014; therefore, this report is required to be submitted by May 12, 2015.

This enclosure provides responses to TS 6.9.1.7 reporting requirements for SG inspections performed during 3R16. Enclosure 2 contains a list of acronyms.

Introduction MPS3 is a four loop Westinghouse pressurized water reactor with Westinghouse Model F SGs. Each SG contains 5,626 U-bend thermally-treated Inconel 600 tubes. The tubing is nominally 0.688 inches outside diameter with a 0.040 inch nominal wall thickness. During SG fabrication, the tubes were hydraulically expanded over the full depth of the 21.23 inch thick tubesheet. The tubesheet was drilled on a square pitch with 0.98 inch spacing. There are 59 rows and 122 columns in each SG. The radius of the row 1 U-bends is 2.20 inches. U-bends in rows 1 through 10 were stress relieved after being formed. Secondary side tube support structures include a flow distribution baffle, seven plate supports with broached holes on the vertical section of the tubes, and six anti-vibration bars (AVBs) on the U-bend section of the tubes. See Figure 1, "Millstone Power Station Unit 3 Steam Generator Arrangement," for an illustration of the steam generator component locations.

The SGs have accrued 22.02 Effective Full Power Years (EFPYs) of operation as of the end of Cycle 16 (October 2014). MPS3 has the capacity to generate a maximum calculated gross output of approximately 1,296 MWe and operates with an average hot leg temperature of 618 degrees Fahrenheit.

EOC16 SG Tube Inspection Report This section provides responses to each of the requirements specified by MPS3 TS 6.9.1.7.

Bold wording represents TS verbiage. The required information is provided immediately following the restatement of each reporting requirement.

A report shall be submitted within 180 days after the initial entry into MODE 4 following completion of an inspection performed in accordance with TS 6.8.4.g, Steam Generator (SG) Program. The report shall include:

a. The scope of inspections performed on each SG,

Serial No.15-005 Docket No. 50-423 Enclosure 1, Page 2 of 17 One hundred percent of the operational tubes within SG A and SG C, a total of 11,181 tubes or approximately 50 percent of the total population of tubes, were inspected full length. The majority of the tubing length was examined with bobbin probes. The U-bends of rows 1 and 2 (475 in-service tubes) were examined by a Motorized Rotating Probe Coil (MRPC) technique in addition to the bobbin probe examination of the straight legs of the tubes. An additional augmented sample of 689 tube locations was examined with a MRPC probe. The augmented sample inspections were performed in areas of special interest including hot leg expansion transitions, tube overexpansion locations within the hot leg tubesheet, dents, as well as locations where the bobbin probe response was ambiguous. An augmented sample of 12,635 tube locations was inspected with an array coil probe. The array coil probe sample included 100% of the hot leg top-of-tubesheet (TTS) locations (11,181 tubes), and approximately 13% of the cold leg TTS locations (1,454 tubes). The extent of the TTS examinations was from the first support structure detected above the secondary face of the tubesheet to 15.2 inches below the secondary face of the tubesheet.

During 3R16, secondary side activities were performed in SGs A, B, C, and D and included the following:

• Deposit Minimization Treatment (DMT) which is a soft chemical cleaning technique.

" High pressure sludge lancing.

" Post-sludge lancing visual examination of TTS annulus and no-tube lane to assess as-left material condition and cleanliness, and to identify and remove any retrievable foreign objects.

• Visual investigation of accessible locations having eddy current indications potentially related to foreign objects, and if present, removal of those retrievable foreign objects.

" Secondary side upper internal examinations within SG A only as follows:

o Steam drum visual inspections to evaluate the material condition and cleanliness of key components such as moisture separators, drain systems, and interior surfaces.

o Drop down examinations (through the primary separators) of the upper tube bundle and AVB supports.

o Visual inspections of feed ring internal interface for flow assisted corrosion.

o Visual inspections of upper tube support plate (TSP) to assess material conditions and cleanliness.

b. Degradation mechanisms found,

Serial No.15-005 Docket No. 50-423 Enclosure 1, Page 3 of 17 The existing degradation mechanisms found during 3R16 included AVB wear, TSP wear, volumetric indications from fabrication and volumetric degradation from foreign object wear.

A summary of the eddy current test (ECT) results from 3R1 6 is provided in Table 1.

c. Nondestructive examination techniques utilized for each degradation mechanism, Table 2 identifies the examination techniques utilized for each identified degradation mechanism.

d. Location, orientation (if linear), and measured sizes (if available) of service induced indications, Tables 3 through 8 identify the AVB wear and non AVB wear volumetric indications reported during 3R16.

e. Number of tubes plugged during the inspection outage for each degradation mechanism, Based on the inspection results, no tubes were plugged during the 3R16 outage.

f. The number and percentage of tubes plugged to date and the effective plugging percentage in each steam generator, The total number of tubes plugged to date and the effective plugging percentage in each SG are summarized below.

Number and Percentaqe of Tubes Pluqqed To Date

.... _______..SG A SG B SGC-- SG D Prior to 3R16 49 25 22 91 During 3R16 0 0 0 0 Total After 3R16 49 25 22 91 Percentage 0.871 0.444 0.391 1.617 Overall Percentage 0.831 Since no sleeving has been performed in the MPS3 SGs, the effective plugging percentage is the same as the actual plugging percentage.

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

testing, No tubes were pulled and no in-situ pressure tests were performed. The condition monitoring assessment concluded that the structural integrity, operational leakage and accident induced leakage performance criteria were not exceeded during the operating interval preceding 3R16.

Serial No.15-005 Docket No. 50-423 Enclosure 1, Page 4 of 17

h. The primary to secondary LEAKAGE rate observed in each SG (if it is not practical to assign the LEAKAGE to an individual SG, the entire primary to secondary LEAKAGE should be conservatively assumed to be from one SG) during the cycle preceding the inspection which is the subject of the report, No primary to secondary SG leakage was reported during Cycle 16.

i. The calculated accident induced leakage rate from the portion of the tubes below 15.2 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 2.49 times the maximum operational primary to secondary leakage rate, the report should describe how it was determined; For the purposes of condition monitoring assessment, and in accordance with the permanent alternate repair criteria, the accident leakage attributed to degradation within the tubesheet below the H* dimension must be estimated by applying a factor of 2.49 to the operational leakage. There was no recordable operational leakage during Cycle 16; hence, the leakage from this degradation during a limiting accident would have been zero (i.e., 2.49 x 0).

j. The results of monitoring for tube axial displacement (slippage). If slippage is discovered, the implications of the discovery and corrective action shall be provided.

The tube slippage monitoring was performed for SG A and SG C using the bobbin coil data during 3R16. There was no detection of slippage identified during 3R16.

Serial No.15-005 Docket No. 50-423 Enclosure 1, Page 5 of 17 Table 1 ECT Examination Summary for 3R16

... __.. ____",.__;_.. . .."_..___....:SG A SGB" SG C SG D Total Number of Tubes Inservice at start of 3R16 5577 5601 5604 5535 22317 Number of Tubes Inspected F/L w/Bobbin Probe 4491 N/A 4524 N/A 9015 Number of Tubes Inspected w/Bobbin Probe Hot Leg Straights 1086 N/A 1080 N/A 2166 (Rows 1 through 9)

Number of Tubes Inspected w/Bobbin Probe Cold Leg Candy Canes 843 N/A 848 N/A 1691 (Rows 3 through 9)

Number of Tubes Inspected w/Bobbin Probe Cold Leg Straights and 243 N/A 232 N/A 475 MRPC U-Bends (Rows 1 and 2)

Previously Plugged Tubes 49 25 22 91 187 Number of Tubes Incomplete w/Bobbin Probe due to Obstruction 0 N/A 0 N/A 0 Number of Examinations w/MRPC (Total)T 598 N/A 566 N/A 1164

• Row 1 and 2 U-Bends 243 N/A 232 N/A 475

" Hot Leg Misc. Special Interest - Diagnostic Exams and from 278 N/A 238 N/A 516 Previous History

" Cold Leg Misc. Special Interest - Diagnostic Exams and from 58 N/A 71 N/A 129 Previous History

• U-bend. Special Interest - Diagnostic Exams and from 19 N/A 19 N/A 38 Previous History

" Other Extent-Based Exams (e.g., foreign object bounding) 0 N/A 6 N/A 6

" "7  : ,j ::...:..:. :. ..... : .... . . ... ... .. ".I' . H i ".'" , * . . " b" , :' : . *. :. . " . . . : .

Number of Examinations w/ARRAY (Total) 6299 N/A 6336 N/A 12,635 Hot Leg Tubesheet (Baffle Plate)* 4338 N/A 4361 N/A 8699 Hot Leg Tubesheet (Non-Baffle)* 1239 N/A 1243 N/A 2482 Cold Leg Tubesheet (Baffle Plate)* 606 N/A 621 N/A 1227 Cold Leg Tubesheet (Non-Baffle)* 116 N/A 111 N/A 227 Foreign Object Wear Bounding 0 N/A 0 N/A 0 Hot Leg OXP/OVR Array Exam Sample Size 100% N/A 100% N/A N/A Cold Leg OXP/OVR Array Exam Sample Size 16% N/A 17% N/A N/A Tubes w/ Max AVB Wear > 40 % 0 N/A 0 N/A 0 Tubes w/ Max AVB Wear > 20% but < 40% 46 N/A 10 N/A 56 Tubes w/ Max AVB Wear < 20% 119 N/A 29 N/A 148 Tubes w/ Max TSP Wear> 40 % 0 N/A 0 N/A 0 Tubes w/ Max TSP Wear> 20% but < 40% 1 N/A 0 N/A 1 Tubes w/ Max TSP Wear < 20% 5 N/A 6 N/A 11 Tubes w/ Max Non-Structure Vol. Deg. > 40 % 0 N/A 0 N/A 0 Tubes w/ Max Non-Structure Vol. Deg. > 20% but < 40% 8 N/A 7 N/A 15 Tubes w/ Max Non-Structure Vol. Deg. < 20% 5 N/A 20 N/A 25 Total Tubes Plugged as a Result of this Inspection: 0 N/A 0 N/A 0

• Due to AVB Wear > 40% 0 N/A 0 N/A 0

• Due to AVB Wear < 40% (discretionary) 0 N/A 0 N/A 0

• Due to Non-Support Volumetric Degradation > 40 % 0 N/A 0 N/A 0

• Due to Non-Support Volumetric Degradation < 40 % 0 N/A 0 N/A 0 (discretionary)

• Due to BET lower than TTS -1" 0 N/A 0 N/A 0

• Due to ID Chatter (discretionary) 0 N/A 0 N/A 0

• Due to an Obstruction 0 N/A 0 N/A 0

$ Values provided in the total and the sub-bullets correspond to the number of examinations performed.

• Within the cutout region, the upper extent of the array probe exam was the second support (i.e., 02H or 02C)

Serial No.15-005 Docket No. 50-423 Enclosure 1, Page 6 of 17 Table 2 Degradation Mechanisms and Inspection Techniques Degradation

-Classification Mechanism Location Probe Type Existing Tube Wear Anti-Vibration Bars Bobbin - Detection and Sizing Bobbin - Detection Existing Tube Wear Tube Support Plate BointTM-D ion

+Pointm - Sizing Bobbin, Array and +PointTM -

Existing Tube Wear (foreign objects) Freespan and ITS Detection

+Poin(rM - Sizing Existing IGAISCC Tube Ends N/A*

Existing FAC Feed Ring and J Tube to Feed Ring Interface Visual Inspection Bobbin - Detection Existing Tube Wear Flow Distribution Baffle BointTM ection

+Point - Sizing ODSCC Hot Leg Top-of-Tubesheet Array - Detection Potential PWSCC and Sludge Region +PointT- Detection and Sizing Bulges, Dents, Manufacturing Array - Detection Potential ODSCC PWSCC Anomalies, Tubesheet and Above-Overexpansions +Pointm- Detection and Sizing (OVR)

Tubesheet Array - Detection Potential PWSCC Overexpansions (OXP) +PointTM- Detection and Sizing PtnilODSCC T Potential PWSCC Row 1 and 2 U-bends +PointM - Detection and Sizing Potential FAC Moisture Separators Visual Inspection Potential PlugProblems Installation Plugs Visual Inspection Potential Tube Slippage Within Tubesheet Bobbin Detection

• Inspection for this mechanism is not necessary under the permanent alternate repair criteria.

Serial No.15-005 Docket No. 50-423 Enclosure 1, Page 7 of 17 Table 3 3R16 Volumetric Degradation Summary SG A (excludes AVB Wear)

.Rw. .Col S . Max Foreign Object Plugged &

• Supth Cause Remaining Stabilized...

2 17 05H -0.74 10 Tube Support Wear No 3 112 06C -0.8 15 Tube Support Wear No 6 122 TSH +4.07 15 Foreign Object Wear No No 7 3 TSC +0.18 26 Foreign Object Wear No No 15 68 07C -0.74 14 Tube Support Wear No 18 94 03H -0.36 11 Tube Support Wear No 20 97 08C -0.87 7 Tube Support Wear No 23 76 03C +0.32 12 Tube Support Wear No 24 11 TSH +0.27 23 Foreign Object Wear No No 28 112 01H +0.55 37 Foreign Object Wear No No 29 109 TSC +0.17 21 Foreign Object Wear No No 29 110 01H +0.62 15 Foreign Object Wear No No 29 110 TSC +0.2 21 Foreign Object Wear No No 35 71 08C -0.92 16 Tube Support Wear No 36 76 01 H +0.5 7 Tube Support Wear No 43 103 TSC +0.74 17 Foreign Object Wear No No 01C +1.17 19 Foreign Object Wear No No 47 24 01C +0.96 29 Foreign Object Wear No No 01C +0.95 25 Foreign Object Wear No No 47 25 01C +1.19 30 Foreign Object Wear No No 58 47 TSC +0.57 19 Sled No 58 76 TSC +0.57 19 Sled No 59 60 08H -1.57 27 Foreign Object Wear No

Serial No.15-005 Docket No. 50-423 Enclosure 1, Page 8 of 17 Table 4 3R16 Volumetric Degradation Summary SG C (excludes AVB Wear)

T* * *'*......*,.==

......* * . Max .= *,. ..~

Fo.reign, Obje~ct*.. Plugged &.....

Row Col *,'**:** Supp  !':::*':!:*, .Cause' D;epth

• 4 i rg i iemaining R:*:i cg ,,Stabilized? ...

1 5 TSC +3.55 15 Foreign Object Wear No No 1 73 TSC +19.52 18 Foreign Object Wear No No 1 102 01C +4.65 19 Foreign Object Wear No No 2 103 01C +12.91 19 Foreign Object Wear No No 13 120 08C -0.65 13 Tube Support Wear No 20 72 02H +5.69 16 Fabrication No 35 78 08C -0.74 11 Tube Support Wear No 35 110 06C -1.04 24 Foreign Object Wear No No TSC +0.63 20 Sled No TSC +0.56 16 Sled No 36 13 TSC +0.61 19 Sled No TSC +0.43 16 Sled No 36 51 08C -0.62 12 Tube Support Wear No 36 75 08C -0.73 9 Tube Support Wear No 38 15 TSC +0.64 19 Sled No 44 102 TSC +0.63 18 Sled No 46 34 TSH +0.44 18 Foreign Object Wear No No 47 34 TSH +0.45 18 Foreign Object Wear No No 47 61 06C -0.61 8 Tube Support Wear No 48 88 07C -0.57 21 Tube Support Wear No 54 64 TSH +0.28 28 Foreign Object Wear No No 55 68 TSH +0.78 21 Foreign Object Wear No No 56 41 TSH +0.64 18 Foreign Object Wear No No 56 69 TSH +0.23 29 Foreign Object Wear No No TSC +0.62 16 Sled No 56 82 TSC +0.62 18 Sled No

Serial No.15-005 Docket No. 50-423 Enclosure 1, Page 9 of 17 Table 4 3R16 Volumetric Degradation Summary SG C (excludes AVB Wear)

S... Col:

. Supp Max Caue Foreign Object Plugged &

Row Col Supp Depth Cause Remaining Stabilized?

57 44 TSH +0.59 17 Sled No 58 48 TSC +0.65 20 Sled No 58 48 TSH +0.67 17 Sled No 58 49 TSC +0.61 17 Sled No 58 49 TSH +0.61 17 Sled No 58 76 TSC +0.72 19 Sled No 58 76 TSH +0.55 19 Sled No 59 55 TSC +0.68 18 Sled No 59 59 TSC +0.67 17 Foreign Object Wear No No 59 68 TSH +0.57 18 Sled No

Serial No.15-005 Docket No. 50-423 Enclosure 1, Page 10 of 17 Table 5 AVB Wear Listings, Steam Generator A - Repeat Indications

Row. Col AVB *%TW Row C;oCal AVB %TW 12 121 AV6 11 34 46 AV4 15 22 78 AV1 14 34 46 AV5 28 22 78 AV5 16 34 46 AV6 33 22 78 AV6 11 34 48 AVi 19 24 116 AV6 11 34 48 AV2 19 26 115 AVI 25 34 48 AV3 27 26 44 AV2 17 34 73 AV3 14 26 44 AV5 16 34 73 AV4 33 27 115 AVi 19 34 73 AV5 36 28 113 AV5 8 34 73 AV6 10 28 115 AVI 32 34 85 AV5 17 28 36 AV5 10 34 91 AV2 12 29 114 AV2 15 34 91 AV4 9 29 114 AV5 11 34 97 AV3 13 29 12 AV2 14 34 98 AV4 9 29 40 AV2 10 35 100 AV3 12 29 67 AVi 11 35 108 AV2 11 29 67 AV2 15 35 108 AV3 15 29 67 AV5 12 35 49 AV2 12 29 79 AV5 10 35 49 AV5 13 30 10 AV5 15 35 49 AV6 11 30 11 AV5 9 35 59 AV2 29 30 113 AV5 21 35 59 AV3 13 30 114 AVI 13 35 59 AV4 13 30 40 AV2 14 35 59 AV6 14 30 9 AV5 31 35 60 AV4 25 31 109 AV2 10 35 60 AV5 17 31 61 AV5 11 35 60 AV6 10 32 11 AV4 20 35 61 AV2 15 32 i11 AV5 18 35 61 AV4 14 33 il1 AV6 9 35 65 AV2 14 34 107 AV4 10 35 65 AV3 14 34 109 AV4 28 35 65 AV4 15 34 15 AV6 10 35 65 AV5 18 34 41 AV3 17 35 71 AV3 11 34 41 AV4 10 35 71 AV4 25 34 44 AV3 7 35 71 AV5 14 34 46 AV3 18 35 71 AV6 10

Serial No.15-005 Docket No. 50-423 Enclosure 1, Page 11 of 17 Table 5 AVB Wear Listings, Steam Generator A - Repeat Indications Row Col. AVB %TW. Row Col AVB %TW S*

"i...... * .

35 77 AV2 13 39 51 AV3 15 35 77 AV3 20 39 51 AV4 12 35 77 AV4 14 39 57 AV1 13 35 77 AV5 11 39 57 AV2 30 35 80 AV3 10 39 57 AV3 18 35 90 AV2 11 39 57 AV4 18 37 100 AV3 15 39 57 AV5 9 37 100 AV4 12 39 60 AV4 25 37 100 AV5 15 39 62 AV5 10 37 102 AV4 5 39 62 AV6 10 37 106 AV4 18 39 70 AV2 10 37 106 AV5 10 39 70 AV3 17 37 45 AV2 31 39 70 AV4 9 37 45 AV3 21 39 71 AV2 9 37 45 AV4 13 39 71 AV4 19 37 45 AV5 16 39 71 AV5 18 37 56 AV3 16 39 71 AV6 14 37 56 AV4 18 39 75 AV3 11 37 69 AV5 20 39 75 AV4 13 37 69 AV6 19 39 75 AV5 17 37 72 AV3 10 39 75 AV6 15 37 89 AV3 9 39 78 AV3 13 37 90 AV3 23 40 100 AV3 12 37 90 AV4 14 40 102 AV4 9 37 90 AV5 10 40 45 AV3 13 37 91 AV3 23 40 45 AV4 28 37 91 AV4 14 40 45 AV5 14 37 91 AV5 27 40 51 AV4 21 37 91 AV6 21 40 51 AV5 29 37 92 AV5 18 40 58 AV2 14 37 99 AV3 7 40 58 AV3 16 38 106 AV3 19 40 58 AV5 10 38 106 AV4 16 40 64 AV4 17 38 106 AV5 14 40 67 AV2 9 38 52 AV2 17 40 67 AV3 10 38 52 AV3 15 40 71 AV2 16 38 79 AV6 11 40 71 AV3 23 38 86 AV5 14 40 71 AV4 28

Serial No.15-005 Docket No. 50-423 Enclosure 1, Page 12 of 17 Table 5 AVB Wear Listings, Steam Generator A - Repeat Indications Row Col AVB %TW* .Row Col AVB %TW 40 86 AV2 12 42 85 AV2 10 40 94 AV5 21 42 85 AV4 14 41 100 AV3 10 42 86 AV3 10 41 101 AV4 10 42 86 AV4 12 41 101 AV5 11 42 93 AV3 16 41 102 AV4 25 42 93 AV4 19 41 102 AV5 10 42 93 AV5 24 41 61 AV3 21 42 98 AVi 7 41 61 AV4 26 42 98 AV3 31 41 74 AV5 10 42 98 AV4 29 41 87 AV4 18 43 101 AV3 10 42 101 AV2 21 43 101 AV4 19 42 101 AV3 14 43 101 AV5 16 42 101 AV4 24 43 102 AV4 16 42 101 AV5 23 43 102 AV5 17 42 102 AV3 20 43 103 AV5 14 42 102 AV4 32 43 20 AV6 6 42 102 AV5 24 43 49 AV2 11 42 103 AV3 14 43 49 AV3 10 42 103 AV4 13 43 64 AV3 13 42 20 AV6 10 43 64 AV4 13 42 33 AV3 21 43 64 AV5 18 42 33 AV4 13 43 76 AV4 13 42 37 AV2 14 43 80 AV3 20 42 37 AV3 11 43 80 AV4 23 42 37 AV6 13 43 80 AV5 13 42 43 AV2 20 43 80 AV6 15 42 43 AV3 18 43 87 AV2 20 42 53 AV3 11 43 87 AV4 20 42 53 AV4 21 43 87 AV5 21 42 53 AV5 18 43 96 AV5 12 42 63 AV2 11 43 98 AV4 16 42 63 AV3 19 43 98 AV5 12 42 63 AV4 13 43 99 AV4 14 42 63 AV5 9 44 64 AV2 29 42 77 AV2 13 44 64 AV3 19 42 77 AV3 15 44 74 AV4 17 42 77 AV4 27 44 74 AV5 23

Serial No.15-005 Docket No. 50-423 Enclosure 1, Page 13 of 17 Table 5 AVB Wear Listings, Steam Generator A - Repeat Indications Row Col AVB %TW Row Col AVB %TW.

44 74 AV6 18 50 44 AV6 12 44 75 AV3 13 50 50 AV4 19 44 96 AV2 15 50 76 AV2 23 44 96 AV4 17 50 76 AV3 20 44 96 AV5 12 50 82 AV2 20 44 98 AV1 11 50 82 AV3 24 44 98 AV2 23 50 82 AV4 21 44 98 AV4 14 50 86 AV2 13 45 45 AV3 9 50 87 AV2 27 45 71 AV2 13 50 87 AV3 16 45 98 AV4 22 50 87 AV5 9 45 98 AV5 10 51 64 AV3 12 45 98 AV6 14 51 65 AV3 9 45 99 AV4 12 51 65 AV4 9 45 99 AV5 7 51 65 AV5 13 46 97 AV5 10 51 66 AV2 11 46 98 AV5 7 51 66 AV3 10 46 99 AV2 12 51 79 AV3 10 46 99 AV4 17 52 66 AV4 27 46 99 AV5 20 52 90 AV3 13 47 98 AV3 11 52 90 AV4 12 47 99 AV6 10 53 81 AVi 13 48 25 AV3 9 53 81 AV3 29 48 26 AV2 9 54 35 AV4 17 48 26 AV6 10 54 35 AV5 18 48 96 AV6 12 54 49 AV2 14 49 95 AV4 9 54 49 AV3 10 50 29 AV4 10 56 41 AV2 13 50 29 AV5 13 58 54 AV1 13 50 44 AV3 13 59 64 AV6 10 50 44 AV4 16 50 44 AV5 33

Serial No.15-005 Docket No. 50-423 Enclosure 1, Page 14 of 17 Table 6 AVB Wear Listings, Steam Generator A - New Indications Row. Col Supp %TW 21 118 AV6 11 27 8 AV1 11 27 8 AV6 11 27 9 AV3 14 28 36 AV1 10 30 113 AV6 11 34 29 AV3 11 34 29 AV6 10 35 108 AV6 11 35 77 AVi 13 37 34 AVI 11 39 74 AV3 10 41 91 AV3 10 42 53 AV2 10 42 80 AV4 14 43 36 AV1 13 43 85 AV3 10 43 95 AV6 10 45 101 AV6 10 45 96 AV5 10 47 85 AVi 11 49 95 AV2 17 50 76 AV4 12 50 87 AV4 11 51 31 AV2 11 51 64 AV4 11 53 81 AV5 11

Serial No.15-005 Docket No. 50-423 Enclosure 1, Page 15 of 17 Table 7 AVB Wear Listings, SG-C - Repeat Indications Row. Col .AVB %TW Row Col AVB TW. ....

15 66 AV1 8 42 20 AV5 25 25 116 AV6 18 42 20 AV6 15 34 14 AV2 9 42 23 AV3 19 34 14 AV5 11 42 23 AV4 26 36 15 AV5 8 42 23 AV5 25 36 15 AV6 12 45 100 AV5 9 37 15 AV2 20 45 100 AV6 10 37 15 AV3 9 45 57 AV2 9 37 15 AV4 11 46 33 AV6 18 37 15 AV5 28 47 99 AV6 12 37 15 AV6 16 48 98 AV3 10 37 88 AV3 10 48 98 AV4 9 39 17 AV2 14 48 98 AV6 11 39 17 AV3 13 49 96 AV5 20 39 17 AV4 18 49 96 AV6 20 39 17 AV5 20 50 28 AV2 9 39 17 AV6 14 50 28 AV5 17 39 79 AV3 16 50 93 AV5 13 41 105 AV6 9 50 93 AV6 24 41 42 AV3 21 51 92 AV6 11 41 54 -AV1 13 54 35 AV5 13 41 54 AV3 17 54 36 AV4 17 41 54 AV4 15 54 36 AV5 11 41 54 AV5 21 54 86 AVi 9 41 62 AV2 21 56 41 AV2 10 41 62 AV3 15 56 41 AV4 15 41 62 AV3 21 56 41 AV5 24 41 62 AV4 17 56 41 AV6 12 41 62 AV4 25 56 44 AV4 7 41 62 AV5 28 58 49 AV5 11 41 62 AV6 9 41 65 AV4 15 41 65 AV5 17 42 103 AV3 11 42 20 AV2 15 42 20 AV3 22 42 20 AV4 24

Serial No.15-005 Docket No. 50-423 Enclosure 1, Page 16 of 17 Table 8 AVB Wear Listings, Steam Generator C - New Indications Row Col Supp. .,.W 25 8 AVI 10 38 65 AV6 10 39 107 AV6 11 46 97 AVi 10 46 97 AV3 10 48 26 AV4 10 50 95 AV6 10 54 85 AV6 11 57 69 AV1 11

Serial No.15-005 Docket No. 50-423 Enclosure 1, Page 17 of 17

. Figure 1 STEAM GENERATOR ARRANGEMENT

[REDACTED]

Serial No.15-005 Docket No. 50-423 ENCLOSURE 2 Acronyms MILLSTONE POWER STATION UNIT 3 DOMINION NUCLEAR CONNECTICUT, INC.

Serial No.15-005 Docket No. 50-423 Enclosure 2, Page 1 of 1 Acronyms AVB Anti-Vibration Bar OVR Above Tubesheet Over Expansion BET Bottom of the Expansion Transition OXP Over Expansion BLG Bulge PID Positive Identification C Column PLG Tube is plugged CL Cold Leg PLP Possible Loose Part DDH Ding or Dent Signal - Reviewed in PTE Partial Tubesheet Expansion History PWR Pressurized Water Reactor DDI Distorted Dent or Ding Indication PWSCC Primary Water Stress Corrosion DDS Ding or Dent Signal - Non- Cracking Confirming w/RPC R Row DNG Ding RAD Retest Analyst Discretion DNT Dent Indication RBD Retest - Bad Data ECT Eddy Current Test RIC Retest - Incomplete EFPY Effective Full Power Years RRT Retest - Restricted Tube EPRI Electric Power Research Institute S/N Signal-to-Noise Ratio ETSS Examination Technique SAI Single Axial Indication Specification Sheet SCC Stress Corrosion Cracking F/L Full Length SCI Single Circumferential Indication FAC Flow Accelerated Corrosion SG Steam Generator FDB Flow Distribution Baffle SLG Sludge FO Foreign Object SSI Secondary Side Inspection FOTS Foreign Object Tracking System SVI Single Volumetric Indication HL Hot Leg Tube End Cold Leg TEC IGA Intergranular Attack TEH Tube End Hot Leg INF Indication Not Found Tangential Flaw-Like Signal - Reviewed TFH INR Indication Not Reportable in History LPI Loose Part Indication TFS Tangential Flaw-Like Signal - Non-LPR Loose Part Removed Confirming w/RPC LPS Loose Part Signal TSC Top of Tubesheet Cold Leg MRPC Motorized Rotating Pancake Coil TSH Top of Tubesheet Hot Leg NDD No Detectable Degradation TTS Top of Tubesheet NDE Nondestructive Examination TWD Through-Wall Depth NDF No Degradation Found %TW Percent Through-Wall NEI Nuclear Energy Institute VOL Volumetric Indication NQH Non-quantifiable Indication -

Reviewed in History NQI Non-quantifiable Indication OA Operational Assessment ODSCC Outer Diameter Stress Corrosion Cracking