ML030550107

From kanterella
Jump to navigation Jump to search
End-of-Cycle 19 Refueling Outage, November 2002 Steam Generator Inservice Inspection Summary Report
ML030550107
Person / Time
Site: Oconee Duke Energy icon.png
Issue date: 02/12/2003
From: Rosalyn Jones
Duke Power Co
To:
Document Control Desk, Office of Nuclear Reactor Regulation
References
Download: ML030550107 (19)
v • d • e


Text

D Duke R A.JONES Lr Power Vice President A Duke Energy Company Duke Power 29672 / Oconee Nuclear Site 7800 Rochester Highway Seneca, SC 29672 864 885 3158 864 885 3564 fax February 12, 2003 U. S. Nuclear Regulatory Commission Document Control Desk Washington, DC 20555

Subject:

Oconee Nuclear Station, Unit 2 Docket No. 50-270 End-of-Cyclel 9 Refueling Outage, November 2002 Steam Generator Inservice Inspection Summary Report Enclosed is a copy of the Steam Generator Tube Inservice Inspection Summary Report for the subject refueling outage. This Summary Report is provided per American Society of Mechanical Engineers Boiler and Pressure Vessel Code,Section XI, Article IWA-6230.

Please address questions to R. C. Douglas at (864) 885-3073.

Very try *u rs, Site Vice President Enclosure www duke-energy corn

U. S. Nuclear Regulatory Commission Page 2 February 12, 2003 xc w/attachments: Mr. Luis A. Reyes Regional Administrator, Region II xc w/o attachments: Mr. M. C. Shannon NRC Senior Resident Inspector Mr. L. N. Olshan ONRR, Senior Project Manager Mr. Virgil R. Autry DHEC

Enclosure Oconee Unit 2 End-of-Cycle 19 Steam Generator Inservice Inspection Summary Report Number Contents of Pages Signature Sheet 1 Form NIS-1 2 Attachment to NIS-1 12

Steam Generator In-service Inspection Summary Report Oconee Unit 2 2002 Outage EOC 19 Location: 7800 Rochester Highway, Seneca, South Carolina 29672 NRC Docket No. 50-270 National Board No. N/A Commercial Service Date: September 9, 1974 Owner: Duke Energy Corporation 526 South Church St.

Charlotte, N.C. 28201-1006 f Revision 0 Prepared By: Date: 1211 /f 0 "u~d~t)

Reviewed By: Date: q21 0?o Approved By: Date: 0 Copy No. 1 Assigned To 0CQ Controlled: " Uncontrolled:

ONS Master File no. OS-208.20

Distribution for Steam Generator In-service Inspection Summary Report Oconee Unit 2 2002 Outage EOC 19 ControlledDistribution Copy No. Assigned To Original Oconee Nuclear Station Document Control Master File OS -208.20 1 NRC Document Control UncontrolledDistribution 2 Hartford Steam Boiler Of Connecticut (AIA)

FORM NIS-I OWNER'S DATA REPORT FOR INSERVICE INSPECTIONS As required by the Provisions of the ASME Code Rules

1. Owner: Duke Energy Corporation, 526 S. Church St. Charlotte, NC 28201-1006 (Name and Address of Owner)
2. Plant: Oconee Nuclear Station, 7800 Rochester Highway, Seneca, SC 29672 (Name and Address of Plant)
3. Plant Unit: 2
4. Owner Certificate of Authorization (if required) N/A
5. Commercial Service Date: September 9, 1974
6. National Board Number for Unit N/A
7. Components Inspected:

Manufacturer State or National Component Manufacturer Serial No. Province No. Board No.

Steam Generator A Babcock & Wilcox 620-0004-55-2 N/A N-108 Steam Generator B Babcock & Wilcox 620-0004-55-1 N/A N-107 Note: Supplemental sheets in form of lists, sketches, or drawings may be used provided (1) size is 81/2 in. x 11 in., (2) information in items 1 through 6 on this data report is included on each sheet, and (3) each sheet is numbered and the number of sheets is recorded at the top of this form.

FORM NIS-1 (Back)

8. Examination Dates: May 14, 2001 TO October 12, 2002
9. Inspection Period Identification: Third Period
10. Inspection Interval Identification: Third Interval
11. Applicable Edition of Section XI: 1989 Addenda None
12. Date/Revision of Inspection Plan: Technical Specification 5.5.10 Steam Generator, through 9/5/02 Tech. Spec. Revision
13. Abstract of Examinations and Test. Reference attached Steam Generator In-service Inspection Summary Report
14. Abstract of Results of Examination and Tests. Reference attached Steam Generator In-service Inspection Summary Report
15. Abstract of Corrective Measures. Reference attached Steam Generator In-service Inspection Summary Report We certify that a) the statements made in this report are correct b) the examinations and tests meet the Inspection Plan as required by the ASME Code,Section XI, and c) corrective measures taken conform to the rules of the ASME Code,Section XI.

Certificate of Authorization No. (if applicable) N/A Expiration Date N/A Date , --- (' 20 02 Signed Duke Energy Corp. By _____ ,__ ___

Owner CERTIFICATE OF INSERVICE INSPECTION I, the undersigned, holding a valid commission issued by the National Board of Boiler and Pressure Vessel Inspectors and the State of Province of South Carolina employed by *The HSB CT have inspected the components described in this Owner's Report during the period 6- 0 I to 9- ' - 0 3o -, and state that to the best of my knowledge and belief, the Owner has performed examinations and tests and taken corrective measures described in the Owner's Report in accordance with the Inspection Plan and as required by the ASME Code,Section XI.

By signing this certificate neither the Inspector nor his employer makes any warranty, expressed or implied, concerning the examinations, test, and corrective measures described in this Owner's Report.

Furthermore, neither the Inspector nor his employer shall be liable in any manner for any personal injury or property damage or a loss of any kind arising from or connected with this inspection 07*,- '/ Commissions I. 6 A':

A,,- i C Inspector's Signature National Board, State, Province, and Endorsements Date a {-G- a oo

  • __-80_ X/&/03
  • Hartford Steam Boiler of Connecticut 200 Ashford Center North Suite 300 Atlanta, GA. 30338

Attachment to Form NIS-1 Steam Generator In-service Inspection Summary Report Oconee Nuclear Station Unit 2 - 2002 Outage EOC-19 Steam Generator Tubing Surveillance 1.0 Introduction Eddy current examinations were performed on the 0.625" OD x 0.037" wall Inconel 600 tubing and the sleeved portion of the tubes in steam generators "A" and "B" at the Oconee Nuclear Station Unit 2 during the October 2002 refueling outage ONS 2 EOC 19.

Framatome ANP DE&S prepared this report as a summary of the eddy current results.

2.0 Technical Summary This section provides a technical summary of the eddy current examinations performed at Duke Energy's, Oconee Nuclear Station, Unit 2 EOC19.

The Inconel 600 tubing in the two Babcock and Wilcox once through steam generators (OTSG's) "A" and "B" were examined by various eddy current techniques. The tubing in the generators measures 0.625 inch nominal outside diameter with a 0.037 inch nominal wall thickness.

Personnel from Framatome ANP DE&S, Framatome ANP (FANP),

ANATEC, and MoreTech performed the examinations during the 19th refueling outage.

A magnetic-bias bobbin coil examination was performed on 14,661 tubes in steam generator "A" and 14,403 tubes in steam generator "B". All in service sleeves were examined with a bobbin coil probe. A single coil "plus-point" motorized rotating coil MRPC probe was used to examine sleeve upper and lower rolls. All 1-600 and 1-690 plugs were visually examined during this refueling outage. Special Interest locations, upper tubesheet rolls and lower tubesheets were examined with two-coil MRPC probe.

A total of 13 tubes were de-plugged and examined in OTSG "A" and 25 in OTSG "B". A magnetic-bias bobbin coil examination was performed after the plug removal. Special interest locations were examined with two-coil MRPC8 probe.

SG In-service Inspection Page 1 of 12 ONS-2 EOC-19 Summary Report

2.1 Summary The following summarizes the results of eddy current examinations for each steam generator.

Note: Attachment 1 contains a list of all three-letter codes and acronyms used throughout this report.

OTSG A:

0 Eddy current examinations began on 10/15/02 @ 0900 and were completed on 10/29/02 @ 1100.

  • 430 tubes were removed from service by plugging.
  • 14,661 tubes were examined with a bobbin coil probe, does not include de-plugged tubes.
  • 2 tubes were reported to have indications of 40% TW or greater with the bobbin coil probe examination.
  • 18 tubes were reported to have indications of 20-39% TW with the bobbin coil probe examination.

0 275 sleeves were examined with a bobbin coil probe.

0 275 sleeves were examined with the plus point coil MRPC probe at the upper and lower rolls.

  • 207 tubes in the lane/wedge region were examined at the 015 TSP and UTS intersections with a 2-coil MRPC probe.

0 14,386 HLRT were examined with the plus point 2-coil MRPC probe.

  • 2034 LTS were examined with the plus point 2-coil MRPC probe.
  • 2 LTS Manufacture Re-rolls were examined with the plus point coil MRPC probe.
  • 2,182 tubes were examined for SI using the 2-coil MRPC probe.
  • 13 de-plugged tubes were examined with a bobbin coil probe.
  • 13 de-plugged tubes were examined for Sl using the 2-coil MRPC probe.

OTSG B:

  • Eddy current examinations began on 10/16/02 @ 0400 and were completed on 10/30/02 @ 0300.
  • 38 tubes were repaired using FTI/ANP "Re-rolling" process
  • 560 tubes were removed from service by plugging, 25 tubes were de-plugged in the upper and re-plugged.
  • 14,403 tubes were examined with a bobbin coil probe, does not include de-plugged tubes.

SG In-service Inspection Page 2 of 12 ONS-2 EOC-1 9 Summary Report

1 tube was reported to have indications of 40% TW or greater with the bobbin coil probe examination.

32 tubes were reported to have indications of 20-39% TW with the bobbin coil probe examination.

  • 251 sleeves were examined with a bobbin coil probe.
  • 251 sleeves were examined with the plus-point coil MRPC probe at the upper and lower rolls.

201 tubes in the lane/wedge region were examined at the 015 TSP and UTS intersections with the 2-coil MRPC probe.

14,152 HLRT were examined with the plus point 2-coil MRPC probe.

  • 2,085 LTS were examined with the plus point 2-coil MRPC probe.
  • 1 LTS Manufacture Re-roll was examined with the plus point coil MRPC probe.
  • 2,964 tubes were examined for Sl using the 2-coil MRPC probe..
  • 25 de-plugged tubes were examined with a bobbin coil probe.
  • 25 de-plugged tubes were examined for Sl using the 2-coil MRPC probe.
  • 38 Re-rolls were examined for Sl using the 2-coil MRPC probe.

2.2 Examinations The examination, equipment and personnel were in compliance with the requirements of the Framatome ANP DE&S NDE Program Manual for In-service Inspection, the applicable Duke Power Co. Technical Specifications, the ASME Boiler and Pressure Vessel Code Section XI, 1989 Edition and industry standards. Analysis of the eddy current data was performed in accordance with the "Eddy Current Analysis Guidelines for Oconee Nuclear Station Unit 2, EOC-1 9.

The steam generator tubing examinations were performed by technicians qualified to Level II, or Level I under direct supervision of personnel qualified to Level II in accordance with Framatome ANP DE&S procedure NDE-B. The data was evaluated by personnel qualified to a minimum of Level IIA in accordance with Framatome ANP DE&S procedure NDE-B. The examination and evaluation procedures used during the eddy current examinations were approved by personnel qualified to Level III in accordance with Framatome ANP DE&S procedure NDE-B.

All inspection frequencies were generated using a Zetec MlZ-30 remote data acquisition unit.

SG In-service Inspection Page 3 of 12 ONS-2 EOC-19 Summary Report

The bobbin coil examinations were performed with .510 inch, .500 inch, and .480 inch diameter probes. The inspection frequencies used were 600, 400, 200 and 35 kHz operating in both differential and absolute modes. A 400/200 kHz differential tube support plate suppression mix was used to enhance the detection of indications occurring at TSP intersections.

The sleeve examinations were performed with a .400 inch diameter bobbin coil probe. The inspection frequencies used were 400, 250, 150 and 75 kHz operating in the differential and absolute mode. A 400/150 kHz differential tube support plate suppression mix was used to enhance the detection of indications occurring at TSP intersections.

Sleeve roll expansions were inspected using a .400 inch diameter plus-point coil MRPC probe. The inspection frequencies used were 200, 120, 75 and 50 kHz operating in the differential mode.

The lane & wedge and special interest examinations were performed with .460 inch diameter 2-coil MRPC probes. The inspection frequencies used were 300, 200, 100 and 15 kHz. A 300/100 kHz TSP suppression mix on the pancake coil was used to enhance the detection of indications occurring at TSP intersections.

Official results of the data analysis were recorded on optical disks and verified by two Eddy Current Data Management systems, Framatome Data Management System, (FDMS) and EddyNet Inspection Management System, (ELMS). These systems are used to check the data for invalid analysis entries, perform data sorting routines, ensure all the proper tubes were examined and to printout final data sheets.

2.3 Areas of Concern In OTSG's, certain modes of degradation have been identified in specific regions of the generator.

Eddy current examinations cannot, in all cases, determine the actual cause of damage. The signal recorded during the eddy current examination can be used to estimate the physical size of any tube damage detected (i.e., penetration into the wall, axial extent), however, the actual type of degradation and its cause can only be determined by tube removal and metallurgical studies.

a) Impingement Erosion - An erosion/corrosion type of discontinuity occurring from the flow of secondary side water with contaminants or debris entrapped in the secondary side fluid stream.

b) High Cycle Fatigue - OD circumferential cracking normally occurring in the vicinity of the 15th TSP or upper tubesheet secondary face (UTS)

SG In-service Inspection Page 4 of 12 ONS-2 EOC-19 Summary Report

in the open lane & wedge region. The initiating mechanism for high cycle fatigue is believed to be a combination of surface damage from corrosion, fretting and high crossflow velocities.

c) Wear - Wear fretting occurs at TSP intersections in tubes near the periphery or outermost rows in the generator. This damage mechanism is caused by flow-induced mechanical vibrations, which are influenced by design parameters, environmental and operating conditions.

d) Inter-granular Stress Corrosion Cracking (IGSCC) - Tube pull results have confirmed the presence of axially oriented inter-granular stress corrosion cracking. IGSCC has been primarily confirmed at locations from the 007TSP and higher. This problem is not associated with a particular region of the steam generator. Indications are characterized as axial and may display a multiple intermittent response over several inches. IGSCC has been confirmed in the sludge pile on the lower tubesheet and noted at the upper tubesheet and dented TSP locations.

e) Inside Diameter Inter-granular Attack (ID IGA) - Numerous indications indicative of ID IGA have been reported in the upper tubesheet of Oconee Unit 1, SG B. This mechanism is not believed to be active and is believed to have been initiated as a result of the manufacturing process and unique to SG B of Unit 1.

f) Primary Water Stress Corrosion Cracking (PWSCC) - PWSCC has been confirmed through tube pulls in the upper tube end (Hot Leg) roll expansion. Indications are generally axially oriented and located in the transition or the expanded region. Plugs and sleeves are also susceptible to this type of damage mechanism.

g) Inter-granular Attack (IGA) - OD initiated IGA has been detected at the upper spans and within the upper tubesheet crevice, lower tubesheet crevice and first span pit-like IGA.

2.4 Results A number of indications within both generators were given a non quantifiable (NQI) code in the percent through-wall column. This code was used during the bobbin examinations for indications where an accurate depth determination could not be made.

Additionally, a number of indications within both generators were reported as an Absolute Drift Indication (ADI) in the percent through wall column. These are indications of degradation that could not be accurately quantified on differential channels.

SG In-service Inspection Page 5 of 12 ONS-2 EOC-19 Summary Report

2.5 OTSG A and B results:

Attachment 2 details the results of the various eddy current examinations performed in OTSG A and OTSG B. A total of four hundred and thirty (430) tubes were removed from service in OTSG "A" and five hundred and sixty (560) tubes in OTSG "B". This total does not include tubes that were de-plugged in upper channel heads.

These tubes were removed from service based on the results of the following eddy current examinations. Refer to Data Management Report for results and specific tube numbers for tubes plugged during the outage.

SG In-service Inspection Page 6 of 12 ONS-2 EOC-19 Summary Report

Attachment 1 DESCRIPTION CODE DESCRIPTION ADI Absolute Drift Indication AXI Axial Indication FTI Framatome Technologies DRS Distorted Roll Signal DWI Dent With Indication HLRT Hot Leg Roll Transition IDI Inside Diameter Indication LTP Lower Tubesheet Primary face LTS Lower Tubesheet Secondary face MAI Multiple Axial Indication MCI Multiple Circumferential Indication MMI Mix Mode Indication MVI Multiple Volumetric Indication MRPC Motorized Rotating Pancake Coil NDD No Degradation Detected NQI Non-Quantifiable Indication OD Outside Diameter ODI Outside Diameter Indication OTSG Once-Through Steam Generator PVN Permeability PWSCC Primary Water Stress-Corrosion Cracking QA Quality Assurance RBD Retest - Bad Data RIC Retest - Incomplete RNC Retest - Number Check SAI Single Axial Indication SCI Single Circumferential Indication SI Special Interest SVI Single Volumetric Indication TEA Tube End Anomalies TSP Tube Support Plate TW Through Wall TWD Through Wall Depth UTP Upper Tubesheet Primary face UTS Upper Tubesheet Secondary face VOL Volumetric indication SG In-service Inspection Page 7 of 12 ONS-2 EOC-19 Summary Report

Attachment 2 ONS 2 EOC 19 OTSG A and B Eddy Current Results.

Bobbin Examinations Steam Generator "A" Steam Generator "B" Tubes Tested: 14,661 Tubes Tested: 14,403 Tubes With Number of Tubes With Number of Indications Indications Indications Indications TWD > 40% 2 2 1 1 TWD 20-39% 18 18 32 32 TWD < 20% 16 16 34 37 ADI 68 70 65 69 NQI 1739 2603 2086 2975 DWI 24 26 30 33 BLG 0 0 1 1 Bobbin Examinations on de-plugged tubes I.

Steam Generator "A" Steam Generator "B" Tubes Tested: 13 Tubes Tested: 25 Tubes With Number of Tubes With Number of Indications Indications Indications Indications TWD > 40% 0 0 0 0 TWD 20-39% 0 0 0 0 TWD < 20% 0 0 0 0 ADI 0 0 3 3 NQI 13 67 22 36 DWI 0 0 0 0 BLG 0 0 1 1 DNT 2 2 1 1 SG In-service Inspection Page 8 of 12 ONS-2 EOC-19 Summary Report

Lane and Wedge Examinations Steam Generator "A" FSteam Generator "B" Tubes Tested: 207 Tubes Tested: 201 Tubes With Number of Tubes With Number of Indications Indications Indications Indications Wear 0 0 0 0 VOL 0 0 0 0 NQI 0 0 0 0 SAI 0 0 0 0 MAI 0 0 0 0 SO 0 0 0 0 MCI 0 0 0 0 MMI 0 0 0 0 SVI 0 0 0 0 DNT 0 0 0 0 MVI 0 0 0 0 Sleeve Roll Examinations Steam Generator "A" Steam Generator "B" Tubes Tested: 275 Tubes Tested: 251 Sleeves With Number of Sleeves With Number of Indications Indications Indications Indications DRS 0 0 1 1 VOL 4 4 1 2 NQI 0 0 0 0 SAI 0 0 1 1 MAI 0 0 0 0 SCI 0 0 0 0 MCI 0 0 0 0 MMI 0 0 0 0 SVI 1 1 0 0 MVI 0 0 0 0 PVN 5 5 2 2 SG In-service Inspection Page 9 of 12 ONS-2 EOC-19 Summary Report

Upper Tubesheet Roll Examinations Steam Generator "A" Steam Generator "B" Tubes Tested: 14,386 1 Tubes Tested: 14,152 Rolls With Number of Rolls With Number of Indications Indications Indications Indications VOL 0 0 2 2 NQI 0 0 0 0 SAI 8 8 12 12 MAI 1 1 0 0 SCI 10 10 118 118 MCI 0 0 7 7 MMI 0 0 1 1 SVI 2 2 2 2 MVI 0 0 0 0 PVN 1 1 1 1 Upper Tubesheet Re-Roll Examinations (re-rolls performed during this RFO)

Steam Generator "A" Steam Generator "B" Tubes Re-Rolled: 0 Tubes Re-Rolled: 38 Re-Rolls With Number of Re-Rolls With Number of Indications Indications Indications Indications VOL N/A N/A 0 0 NQI N/A N/A 0 0 SAI N/A N/A 0 0 MAI N/A N/A 0 0 SCI N/A N/A 0 0 MCI N/A N/A 0 0 MMI N/A N/A 0 0 SVI N/A N/A 0 0 MVI N/A N/A 0 0 SG In-service Inspection Page 10 of 12 ONS-2 EOC-19 Summary Report

Special Interest Examinatiofis Steam Generator "A" Steam Generator "B" Tubes Tested: 2182 Tubes Tested: 2964 Locations Tested: 3679 Locations Tested: 4738 Tubes With Number of Tubes With Number of Indications Indications Indications Indications Wear > 40% 1 1 0 0 Wear 20-39% 53 64 10 10 Wear < 20% 383 457 538 587 VOL 73 79 137 151 SAI 373 1019 486 960 MAI 6 8 5 10 SCI 0 0 0 0 MCI 0 0 0 0 MMI 0 0 0 0 SVI 22 35 50 60 MVI 0 0 0 0 DNT 137 180 334 558 Special Interest Examinations, de-plugged tubes Steam Generator "A" Steam Generator "B" Tubes Tested: 13 Tubes Tested: 25 Tubes With Number of Tubes With Number of Indications Indications Indications Indications Wear > 40% 1 1 0 0 Wear 20-39% 8 15 2 2 Wear < 20% 10 29 16 23 VOL 0 0 3 3 SAI 1 24 0 0 MAI 0 0 0 0 SO 0 0 0 0 MCI 0 0 0 0 MMI 0 0 0 0 SVI 1 1 0 0 MVI 0 0 0 0 DNT 3 3 1 4 SG In-service Inspection Page 11 of 12 ONS-2 EOC-19 Summary Report

Lower Tubesheet Kidney Region Examinations Steam Generator "A" Steam Generator "B" Tubes Tested: 2034 Tubes Tested: 2085 Tubes With Number of Tubes With Number of Indications Indications Indications Indications VOL 2 4 1 1 NQI 0 0 0 0 SAI 1 3 0 0 MAI 0 0 0 0 SO 0 0 0 0 MCI 0 0 0 0 MMI 0 0 0 0 SVI 0 0 0 0 MVI 0 0 0 0 PLP 1 1 0 0 Lower Tubesheet Re-Roll Examinations Steam Generator "A" Steam Generator "B" Re-Rolls Tested: 2 Re-Rolls Tested: 1 Tubes With Number of Tubes With Number of Indications Indications Indications Indications VOL 0 0 0 0 NQI 0 0 0 0 SAI 0 0 0 0 MAI 0 0 0 0 SCI 0 0 0 0 MCI 0 0 0 0 MMI 0 0 0 0 SVI 0 0 0 0 MVI 0 0 0 0 SG In-service Inspection Page 12 of 12 ONS-2 EOC-19 Summary Report

Retrieved from "https://kanterella.com/w/index.php?title=ML030550107&oldid=2674334"