NL-15-2011, Refueling Outrage 1R26 Steam Generator Tube Inspection Report

Refueling Outrage 1R26 Steam Generator Tube Inspection Report

ML15302A277
Person / Time
Site:	Farley
Issue date:	10/29/2015
From:	Pierce C Southern Nuclear Operating Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
NL-15-2011
Download: ML15302A277 (7)

Text

Charles R. Pierce Regulatory Affairs Director OCT 2 9 2011 Docket Nos.: 50-348 Southern Nuclear Operating Company, Inc.

40 Inverness Center Parkway Post Office Box 1295 Birmingham, AL 35242 Tel 205.992.7872 Fax 205.992.7601 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D. C. 20555-0001 Joseph M. Farley Nuclear Plant-Unit 1 SOUTHER.\\

NUCLEAR A SOUTHERN COMPANY NL-15-2011 Refueling Outage 1 R26 Steam Generator Tube Inspection Report Ladies and Gentlemen:

In accordance with the requirements of Joseph M. Farley Nuclear Plant Technical Specification 5.6.1 0, Southern Nuclear Operating Company submits the enclosed report of the steam generator tube inspections performed during the twenty-sixth refueling outage on Unit 1 (1 R26.)

This letter contains no NRC commitments. If you have any questions, please contact Ken McElroy at (205) 992-7369.

Sincerely, tf<*~

C.R. Pierce Regulatory Affairs Director CRP/JMC

Enclosure:

1 R26 Steam Generator Tube Inspection Report

• cc:

Southern Nuclear Operating Company Mr. S. E. Kuczynski, Chairman, President & CEO Mr. D. G. Bast, Executive Vice President & Chief Nuclear Officer Ms. C. A. Gayheart, Vice President - Farley Mr. M. D. Meier, Vice President-Regulatory Affairs Mr. D. R. Madison, Vice President-Fleet Operations Mr. B. J. Adams, Vice President-Engineering Ms. B. L. Taylor, Regulatory Affairs Manager-Farley RTYPE: CFA04.054

U. S. Nuclear Regulatory Commission NL-15-2011 Page 2 U.S. Nuclear Regulatory Commission Mr. L. D. Wert, Regional Administrator (Acting)

Mr. S. A. Williams, NRR Project Manager-Farley Mr. P. K. Niebaum, Senior Resident Inspector-Farley Alabama Department of Public Health Dr. D. E. Williamson, State Health Officer

Joseph M. Farley Nuclear Plant - Unit 1 Refueling Outage 1 R26 Steam Generator Tube Inspection Report Enclosure 1 R26 Steam Generator Tube Inspection Report

Enclosure to NL-15-2011 1 R26 Steam Generator Tube Inspection Report The Joseph M. Farley Nuclear Plant (Farley) - Unit 1 Refueling Outage 26 (1 R26} was conducted after cumulative Replacement Steam Generators (RSG) service equivalent to approximately 13.7 effective full power years (EFPY). The service from previous RSG eddy current inspections at 1 R23 was approximately 4.15 EFPY. No tube leakage was reported during this operating interval comprising of cycles 24, 25, and 26. Based on steam generator (SG) eddy current and visual inspection data, there are two existing degradation mechanisms in the Farley Unit 1 RSGs, and one was observed for the first time during the 1 R26 inspection. The existing degradation mechanisms are:

Mechanical Wear at Anti-Vibration Bar (AVB) Tube Supports Mechanical Wear at Tube Support Plate (TSP) Intersections - NEW A.

The Scope of Inspections Performed on Each Steam Generator The inspection program, as required by EPRI PWR SG Examination Guidelines, addressed the existing and potential degradation mechanisms for Farley Unit 1 RSGs. The defined scope for Farley Unit 1 implemented during refueling outage 1 R26 included the following:

1. Bobbin exams (all 3 SGs) 50% Bobbin full length examination of tubes in all SGs not inspected at 1 R23, except for Rows 1 and 2 which were inspected from tube end to the top TSP from both the hot leg (HL) and cold leg (CL), such that all tubes were inspected in the combined two inspection cycles 1 R23 and 1R26.

2. +Point rotating pancake coil (RPC) (all3 SGs) 50% +Point examination of Rows 1 and 2 U-bends in all SGs not inspected at 1 R23 such that all tubes were inspected in the combined two inspection cycles 1 R23 and 1 R26.

+Point probe examination of the ITS periphery tubes consisting of every other tube three tubes deep on both the HL and CL side at the top of tube sheet (ITS) +1-3 inches in all the SGs. The total number of tests represents at least a 20% +Point probe sample.

1 00% +Point probe examination of all dents and dings ~ 2 volts in the straight lengths and U-bends of all SGs.

+Point tests of Special Interest tube locations in both the HL and CL of possible flaw from the bobbin program.

3. Visual inspection in all SGs channel head primary side HL and CL, inclusive of the entire divider plate to channel head weld and all visible clad surfaces. Specifically, visual inspections of the steam generator hot leg and cold leg divider plates and drain lines were performed, inclusive of the entire divider plate to channel head weld and all visible clad surfaces.

E-1

Enclosure to NL-15-2011 1 R26 Steam Generator Tube Inspection Repqrt

4. ITS Foreign Object Search and Retrieval (FOSAR) (all3 SGs)

Visual examination of tube bundle periphery tubes from both the annulus and tube lane on both the HL and CL.

An in-bundle visual inspection with a focus on regions where objects have been previously identified.

Previous loose part locations and any PLP indications identified by the eddy current program.

5. Steam drum and feedring inspection (all3 SGs)

The steam drum and feedring were inspected for structural integrity, degradation, excessive deposits, flow accelerated corrosion, erosion, blockage, and overall condition.

B.

Active Degradation Mechanisms Found AVB Wear Five indications of AVB wear were identified in one tube, R38 C59, in SG C during Farley 1 R23. The tube was tested again during Farley 1 R26. The bobbin probe sizing of the largest of the five indications was measured at 20% through-wall (TW) while the others were 19% TW, 19% TW, 12%

TW, and 10% TW. This is a change from 16% TW, 16% TW, 15% TW, 10% TW, and 8% TW, respectively. The sixth AVB intersection in SG C was again categorized as a distorted support signal. The bobbin probe sizing results for this degradation mechanism is presented in Table 1 in Section D.

Tube Support Plate Wear Twenty-eight indications of mechanical wear at or near tube intersections with Tube Support Plates (TSP) were identified during 1 R26. The bobbin inspection program performed identified the indications in eighteen different tubes-four in SG A, nine in SG B, and five in SG C.

The indications were subsequently examined with the +Point probe for characterization. The +Point examination allowed the eddy current data analysts to confirm these bobbin calls as volumetric tube wear at TSP intersections. The +Point probe sizing results for this degradation mechanism is presented in Table 2 in Section D. Some of the indications showed interaction with the full 1.12 inch length of the TSP intersection while others were limited to either the top or bottom of the tube intersection with the TSP land.

C.

Nondestructive Examination Techniques Utilized for Each Degradation Mechanism Bobbin and +Point RPC eddy current probes were used to detect both existing and potential degradation mechanisms.

E-2

Enclosure to NL-15-2011 1 R26 Steam Generator Tube Inspection Report D.

Location, Orientation (if Linear) and Measured Sizes (if available) of Service Induced Indication Table 1: Farley 1 R26 AVB Wear Indications: Bobbin SG Row Column Indication c

38 59 PCT c

38 59 PCT c

38 59 PCT c

38 59 PCT c

38 59 PCT c

38 59 DSS

% lWD-Percent Through-Wall Depth PCT-Volumetric Indication Sizing

%TWO 10 19 19 20 12 AV#- Location of AVB Intersection with the Tube DSS-Distorted Support Signal Location AV1 AV2 AV3 AV4 AV5 AV6 Table 2: Farley 1 R26 TSP Wear Indications: +Point SG Row Column Indication

%TWO Location A

1 20 PCT 11 4C A

1 20 PCT 5

4C A

1 20 PCT 9

5C A

1 20 PCT 8

5C A

1 20 PCT 9

6C A

1 41 PCT 12 6C A

1 75 PCT 9

5C A

1 75 PCT 15 6C A

46 37 PCT 6

5H B

1 7

PCT 11 6C B

1 7

PCT 10 6C B

1 22 PCT 6

5C B

2 1

PCT 7

4C B

2 77 PCT 10 5C B

2 77 PCT 4

5C B

4 2

PCT 5

4C B

4 2

PCT 4

4C B

4 2

PCT 6

5C B

4 70 PCT 11 5C B

6 1

PCT 6

5H B

30 55 PCT 10 3H B

46 53 PCT 10 7H c

1 34 PCT 8

6C c

1 74 PCT 5

6C c

1 74 PCT 8

6C c

4 2

PCT 11 5C c

10 4

PCT 9

4H c

16 4

PCT 6

5C E-3

Enclosure to NL-15-2011 1 R26 Steam Generator Tube Inspection Report E.

Number of Tubes Plugged During the Inspection Outage No tubes were plugged in SG 1 A, SG 1 8, or SG 1 C during the 1 R26 refueling outage.

F.

Total Number of Percentage of Tubes Plugged to Date No tubes have been plugged in SG 1 A, SG 1 8, or SG 1 C to date.

Table 3: Farley Unit 1 SG Plugged Tubes SG

1. of Tubes Plugged Total Tubes

%Plugged Tubes in 1R26 Plugged A

3,592 0

0 0.00%

8 3,592 0

0 0.00%

c 3,592 0

0 0.00%

Total 10,776 0

0 0.00%

G.

The results of Condition Monitoring, Including the Results of Tube Pulls and In-Situ Testing Based on the inspection data, AVB wear and TSP wear were the only active degradation mechanisms observed in 1 R26. No indications of AVB and TSP wear were found to be in excess of the Condition Monitoring limits. No tubes exhibited degradation that required in situ pressure testing and there was no primary to secondary leakage prior to the end of the inspection interval. No secondary side tube degradation was attributed to the foreign objects identified from 1 R26 TTS visual inspections and FOSAR. The SG performance criteria for operating leakage and structural integrity were confirmed to have been satisfied for the preceding Farley Unit 1 RSG operating interval.

The visual inspection of the steam generator channel head bowl was performed satisfactory with no degradation observed in the channel heads of all three steam generators. The steam drum and feedring inspections discovered no structural anomalies, and no degradation was observed in any of the steam drum and feedring components.

E-4

Charles R. Pierce Regulatory Affairs Director OCT 2 9 2011 Docket Nos.: 50-348 Southern Nuclear Operating Company, Inc.

40 Inverness Center Parkway Post Office Box 1295 Birmingham, AL 35242 Tel 205.992.7872 Fax 205.992.7601 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D. C. 20555-0001 Joseph M. Farley Nuclear Plant-Unit 1 SOUTHER.\\

NUCLEAR A SOUTHERN COMPANY NL-15-2011 Refueling Outage 1 R26 Steam Generator Tube Inspection Report Ladies and Gentlemen:

In accordance with the requirements of Joseph M. Farley Nuclear Plant Technical Specification 5.6.1 0, Southern Nuclear Operating Company submits the enclosed report of the steam generator tube inspections performed during the twenty-sixth refueling outage on Unit 1 (1 R26.)

This letter contains no NRC commitments. If you have any questions, please contact Ken McElroy at (205) 992-7369.

Sincerely, tf<*~

C.R. Pierce Regulatory Affairs Director CRP/JMC

Enclosure:

1 R26 Steam Generator Tube Inspection Report

• cc:

Southern Nuclear Operating Company Mr. S. E. Kuczynski, Chairman, President & CEO Mr. D. G. Bast, Executive Vice President & Chief Nuclear Officer Ms. C. A. Gayheart, Vice President - Farley Mr. M. D. Meier, Vice President-Regulatory Affairs Mr. D. R. Madison, Vice President-Fleet Operations Mr. B. J. Adams, Vice President-Engineering Ms. B. L. Taylor, Regulatory Affairs Manager-Farley RTYPE: CFA04.054

U. S. Nuclear Regulatory Commission NL-15-2011 Page 2 U.S. Nuclear Regulatory Commission Mr. L. D. Wert, Regional Administrator (Acting)

Mr. S. A. Williams, NRR Project Manager-Farley Mr. P. K. Niebaum, Senior Resident Inspector-Farley Alabama Department of Public Health Dr. D. E. Williamson, State Health Officer

Joseph M. Farley Nuclear Plant - Unit 1 Refueling Outage 1 R26 Steam Generator Tube Inspection Report Enclosure 1 R26 Steam Generator Tube Inspection Report

Enclosure to NL-15-2011 1 R26 Steam Generator Tube Inspection Report The Joseph M. Farley Nuclear Plant (Farley) - Unit 1 Refueling Outage 26 (1 R26} was conducted after cumulative Replacement Steam Generators (RSG) service equivalent to approximately 13.7 effective full power years (EFPY). The service from previous RSG eddy current inspections at 1 R23 was approximately 4.15 EFPY. No tube leakage was reported during this operating interval comprising of cycles 24, 25, and 26. Based on steam generator (SG) eddy current and visual inspection data, there are two existing degradation mechanisms in the Farley Unit 1 RSGs, and one was observed for the first time during the 1 R26 inspection. The existing degradation mechanisms are:

Mechanical Wear at Anti-Vibration Bar (AVB) Tube Supports Mechanical Wear at Tube Support Plate (TSP) Intersections - NEW A.

The Scope of Inspections Performed on Each Steam Generator The inspection program, as required by EPRI PWR SG Examination Guidelines, addressed the existing and potential degradation mechanisms for Farley Unit 1 RSGs. The defined scope for Farley Unit 1 implemented during refueling outage 1 R26 included the following:

1. Bobbin exams (all 3 SGs) 50% Bobbin full length examination of tubes in all SGs not inspected at 1 R23, except for Rows 1 and 2 which were inspected from tube end to the top TSP from both the hot leg (HL) and cold leg (CL), such that all tubes were inspected in the combined two inspection cycles 1 R23 and 1R26.

2. +Point rotating pancake coil (RPC) (all3 SGs) 50% +Point examination of Rows 1 and 2 U-bends in all SGs not inspected at 1 R23 such that all tubes were inspected in the combined two inspection cycles 1 R23 and 1 R26.

+Point probe examination of the ITS periphery tubes consisting of every other tube three tubes deep on both the HL and CL side at the top of tube sheet (ITS) +1-3 inches in all the SGs. The total number of tests represents at least a 20% +Point probe sample.

1 00% +Point probe examination of all dents and dings ~ 2 volts in the straight lengths and U-bends of all SGs.

+Point tests of Special Interest tube locations in both the HL and CL of possible flaw from the bobbin program.

3. Visual inspection in all SGs channel head primary side HL and CL, inclusive of the entire divider plate to channel head weld and all visible clad surfaces. Specifically, visual inspections of the steam generator hot leg and cold leg divider plates and drain lines were performed, inclusive of the entire divider plate to channel head weld and all visible clad surfaces.

E-1

Enclosure to NL-15-2011 1 R26 Steam Generator Tube Inspection Repqrt

4. ITS Foreign Object Search and Retrieval (FOSAR) (all3 SGs)

Visual examination of tube bundle periphery tubes from both the annulus and tube lane on both the HL and CL.

An in-bundle visual inspection with a focus on regions where objects have been previously identified.

Previous loose part locations and any PLP indications identified by the eddy current program.

5. Steam drum and feedring inspection (all3 SGs)

The steam drum and feedring were inspected for structural integrity, degradation, excessive deposits, flow accelerated corrosion, erosion, blockage, and overall condition.

B.

Active Degradation Mechanisms Found AVB Wear Five indications of AVB wear were identified in one tube, R38 C59, in SG C during Farley 1 R23. The tube was tested again during Farley 1 R26. The bobbin probe sizing of the largest of the five indications was measured at 20% through-wall (TW) while the others were 19% TW, 19% TW, 12%

TW, and 10% TW. This is a change from 16% TW, 16% TW, 15% TW, 10% TW, and 8% TW, respectively. The sixth AVB intersection in SG C was again categorized as a distorted support signal. The bobbin probe sizing results for this degradation mechanism is presented in Table 1 in Section D.

Tube Support Plate Wear Twenty-eight indications of mechanical wear at or near tube intersections with Tube Support Plates (TSP) were identified during 1 R26. The bobbin inspection program performed identified the indications in eighteen different tubes-four in SG A, nine in SG B, and five in SG C.

The indications were subsequently examined with the +Point probe for characterization. The +Point examination allowed the eddy current data analysts to confirm these bobbin calls as volumetric tube wear at TSP intersections. The +Point probe sizing results for this degradation mechanism is presented in Table 2 in Section D. Some of the indications showed interaction with the full 1.12 inch length of the TSP intersection while others were limited to either the top or bottom of the tube intersection with the TSP land.

C.

Nondestructive Examination Techniques Utilized for Each Degradation Mechanism Bobbin and +Point RPC eddy current probes were used to detect both existing and potential degradation mechanisms.

E-2

Enclosure to NL-15-2011 1 R26 Steam Generator Tube Inspection Report D.

Location, Orientation (if Linear) and Measured Sizes (if available) of Service Induced Indication Table 1: Farley 1 R26 AVB Wear Indications: Bobbin SG Row Column Indication c

38 59 PCT c

38 59 PCT c

38 59 PCT c

38 59 PCT c

38 59 PCT c

38 59 DSS

% lWD-Percent Through-Wall Depth PCT-Volumetric Indication Sizing

%TWO 10 19 19 20 12 AV#- Location of AVB Intersection with the Tube DSS-Distorted Support Signal Location AV1 AV2 AV3 AV4 AV5 AV6 Table 2: Farley 1 R26 TSP Wear Indications: +Point SG Row Column Indication

%TWO Location A

1 20 PCT 11 4C A

1 20 PCT 5

4C A

1 20 PCT 9

5C A

1 20 PCT 8

5C A

1 20 PCT 9

6C A

1 41 PCT 12 6C A

1 75 PCT 9

5C A

1 75 PCT 15 6C A

46 37 PCT 6

5H B

1 7

PCT 11 6C B

1 7

PCT 10 6C B

1 22 PCT 6

5C B

2 1

PCT 7

4C B

2 77 PCT 10 5C B

2 77 PCT 4

5C B

4 2

PCT 5

4C B

4 2

PCT 4

4C B

4 2

PCT 6

5C B

4 70 PCT 11 5C B

6 1

PCT 6

5H B

30 55 PCT 10 3H B

46 53 PCT 10 7H c

1 34 PCT 8

6C c

1 74 PCT 5

6C c

1 74 PCT 8

6C c

4 2

PCT 11 5C c

10 4

PCT 9

4H c

16 4

PCT 6

5C E-3

Enclosure to NL-15-2011 1 R26 Steam Generator Tube Inspection Report E.

Number of Tubes Plugged During the Inspection Outage No tubes were plugged in SG 1 A, SG 1 8, or SG 1 C during the 1 R26 refueling outage.

F.

Total Number of Percentage of Tubes Plugged to Date No tubes have been plugged in SG 1 A, SG 1 8, or SG 1 C to date.

Table 3: Farley Unit 1 SG Plugged Tubes SG

1. of Tubes Plugged Total Tubes

%Plugged Tubes in 1R26 Plugged A

3,592 0

0 0.00%

8 3,592 0

0 0.00%

c 3,592 0

0 0.00%

Total 10,776 0

0 0.00%

G.

The results of Condition Monitoring, Including the Results of Tube Pulls and In-Situ Testing Based on the inspection data, AVB wear and TSP wear were the only active degradation mechanisms observed in 1 R26. No indications of AVB and TSP wear were found to be in excess of the Condition Monitoring limits. No tubes exhibited degradation that required in situ pressure testing and there was no primary to secondary leakage prior to the end of the inspection interval. No secondary side tube degradation was attributed to the foreign objects identified from 1 R26 TTS visual inspections and FOSAR. The SG performance criteria for operating leakage and structural integrity were confirmed to have been satisfied for the preceding Farley Unit 1 RSG operating interval.

The visual inspection of the steam generator channel head bowl was performed satisfactory with no degradation observed in the channel heads of all three steam generators. The steam drum and feedring inspections discovered no structural anomalies, and no degradation was observed in any of the steam drum and feedring components.

E-4