BYRON 2008-0063, Steam Generator Inservice Inspection Summary Report for Refueling Outage 15
| ML081830086 | |
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|---|---|
| Site: | Byron  |
| Issue date: | 06/30/2008 |
| From: | Hoots D Exelon Generation Co, Exelon Nuclear |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
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| 1.10.0101, 3.11.0320, BYRON 2008-0063 | |
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Text
Exelon Exelon Generation Con1pany. LlC Byron Station www.exeloncorp.com Nuclear 4450 North GeTman Church ROJd Byron, Il 61010-9794 June 30, 2008 LTR: BYRON 2008-0063 File: 3.11.0320 1.10.0101 U. S. Nuclear Regulatory Commission AnN: Document Control Desk Washington, DC 20555-0001 Byron Nuclear Power Station, Unit 1 Facility Operating License NPF-37 NRC Docket No. STN 50-454
Subject:
Byron Station Unit 1 Steam Generator Inservice Inspection Summary Report for Refueling Outage 15 In accordance with Technical Specification 5.6.9, "Steam Generator (SG) Tube Inspection Report," Exelon Generation Company, LLC is reporting the results of the steam generator inspections that were completed during the Byron Station Unit 1, Refueling Outage 15. The attached report is also being submitted in accordance with the requirements of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code, 2001 Edition through the 2003 Addenda,Section XI, "Rules for Inservice Inspection of Nuclear Power Plant Components," Article IWA-6000, "Records and Reports," and Paragraph 11-890.2.3, "Reporting" of ASME Section V "Nondestructive Examination", Article 8 - AppendiX II, "Eddy Current Examination of Non-Ferromagnetic Heat Exchanger Tubing", 2001 Edition through the 2003 Addenda.
If there are any questions regarding this report, please contact W. Grundmann, Regulatory Assurance Manager, at (815) 406-2800.
Respectfully,
~~
David M. Hoots Site Vice President Byron Nuclear Generating Station
Attachment:
Byron Station Unit 1 Steam Generator Eddy Current Inspection Report Refueling Outage 15, March 2008 DMH/JRSffLH/vym
Exelon Generation Company, LLC BYRON STATION UNIT 1 4450 North German Church Road Byron, Illinois 61010 COMMERCIAL OPERATION: September 16,1985 BYRON STATION UNIT 1 STEAM GENERATOR EDDY CURRENT INSPECTION REPORT REFUELING OUTAGE 15 March 2008 Exelon Generation Company, LLC 200 Exelon Way Kennett Square, PA 19348 Mailing Address 4300 Winfield Road Warrenville, IL 60555 Documentation Completed Date: June 16, 2008 Page 1 of 68
TABLE OF CONTENTS
1.0 INTRODUCTION
3 2.0
SUMMARY
3 3.0 CERTIFiCATIONS .4 3.1 Procedures/Examinations/Equipment .4 3.2 Personnel 5 4.0 EXAMINATION TECHNIQUE AND EXAMINATION SCOPE 7 4.1 SG Tube Examination Techniques 7 4.2 SG Tube Inspection Scope 8 4.3 Recording of Examination Data 9 4.4 Witness and Verification of Examination 9 5.0 EXAMINATION RESULTS 9 5.1 Indications Found 9 5.2 Other SG Inspection Results 10 6.0 RESULTS OF CONDITION MONITORING 11 6.1 Fan Bar Wear 12 6.2 Lattice Grid Wear 12 6.3 Foreign Object Wear 12 6.4 Primary-to-Secondary Leakage Assessment.. 12 7.0 REPAIR
SUMMARY
13 8.0 DOCUMENTATION 13 9.0 FIGURESITABLES/ATTACHMENTS 14 Page 2 of 68
1.0 INTRODUCTION
Byron Station Unit 1 operates with four Babcock & Wilcox Replacement Steam Generators (SGs) in the four loop pressurized water reactor system. The SGs each contain 6633 thermally treated Alloy-690 U-tubes that have a nominal diameter of 0.6875 inches and a nominal thickness of 0.040 inches. The tubes are supported by stainless steel lattice grid structures and fan bars. The tubes are hydraulically expanded into the full depth of the tubesheet. Main Feedwater enters the SGs above the tube bundle through a feedring and J-tubes. The SG configuration is shown in Figure A.1.
The replacements SGs were installed during the eighth refueling outage.
In accordance with Byron Station Technical Specification (TS) 3.4.19, "Steam Generator (SG) Tube Integrity", TS 5.5.9, "Steam Generator (SG) Program," and American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel (B&PV) Code Section XI 2001 Edition through the 2003 Addenda, IWB 2500-1, Examination Category B-Q, Item B16.20, SG eddy current examinations were performed during the Byron Station, Unit 1 Refueling Outage 15.
The Byron Unit 1 SG's are currently in their first 144 effective full power month (EFPM) inspection interval following SG replacement, per TS 5.5.9.d.2. The Byron Unit 1 SG's have operated 102.14 EFPM within the 144 EFPM Inspection Period at Refueling Outage
- 15. Refueling Outage 15 was neither the inspection period mid-point outage nor the inspection period end-point outage. The mid-point inspection outage was conducted during Refueling Outage 13 (67.9 EFPM within the inspection period) and the end-point inspection outage is expected to be conducted during the Refueling Outage 17 inspection.
The Refueling Outage 15 inspections were performed consistent with the Electric Power Research Institute (EPRI) "PWR Steam Generator Examination Guidelines: Revision 6",
applicable interim guidance and Nuclear Energy Institute (NEI) 97-06, "Steam Generator Program Guidelines, Revision 2." Westinghouse Electric Company LLC conducted the field inspection activities from March 27 through April 5, 2007. The following tube inspections were performed during this outage (TS 5.6.9.a).
o 100% Full Length Bobbin Coil in all four SGs o 100% Plus-Point of the Hot Leg Dents/Dings :;:2.0 volts in all four SGs o 100% Visual Inspection of Previously Installed Welded Tube Plugs o 100% Visual Inspection of Previously Installed Mechanical Tube Plugs in all four SGs o 100% Visual Inspection of Newly Installed Tube Plugs 2.0
SUMMARY
The guidance in Revision 6 of the EPRI "PWR Steam Generator Examination Guidelines" (Le., EPRI Guidelines and applicable interim guidance) was used during this inspection. A degradation assessment was performed prior to each inspection to ensure the proper EPRI Appendix H, "Performance Demonstration for Eddy Current Examination," qualified inspection techniques were used to detect any existing and potential modes of degradation. Each technique was evaluated to ensure that the detection and sizing capabilities are applicable to the Byron Station, Unit 1 site-specific condition in accordance with Section 6.3.2 of the EPRI Guidelines. All data analysts were qualified to Appendix G, "Qualification of Nondestructive Examination Personnel for Analysis of Nondestructive Examination Data," of the EPRI Guidelines (Le., Qualified Data Analyst (QDA)). All data analyst and acquisition personnel satisfactorily completed site specific performance Page 3 of 68
training and testing. An independent QDA process control review was employed to randomly sample the data to ensure that the analysis resolution process was properly performed and that the field calls were properly reported. An analysis feedback process was implemented that required the data analysts to review their missed calls and overcalls on a daily basis.
The modes of tube degradation found during the current inspection were fan bar wear, and lattice grid support plate wear. Pursuant to EPRI Guideline Section 3.5, "Inspection Results Categories", the results of the inspection were classified as inspection category C-1 for all SG's. There were no scanning limitations during the examinations.
As a result of the current eddy current inspections and response to conditions found, a total of thirteen (13) tubes were preventatively repaired by tube stabilization and tube plugging. Table 2.1 provides the tube plugging levels for each SG. Table 2.2 provides the total number of tubes plugged in the current outage by degradation mode.
TABLE 2.1 Equivalent Tube Plugging Level (TS 5.6.9.f & TS 5.6.9.h)
SGA SGB SGC SGD TOTAL Tubes Previously Plugged 1 1 1 5 8 Tubes Plugged in Cycle 13 0 0 13 0 13 Total Tubes Plugged 1 1 14 5 21 Total Tubes Plugged (%) 0.015% 0.015% 0.21% 0.075% 0.08%
- Each SG contains 6633 Tubes TABLE 2.2 Tubes Plugged During Refueling Outage 15 (TS 5.6.9.e)
Mode of Degradation SGA SGB SGC SGD Total Fan Bar Wear 0 0 0 0 0 Lattice Grid Wear 0 0 0 0 0 Foreign Object Wear 0 0 0 0 0 Preventatively Plugged 0 0 13 0 13 Refueling Outage 15 0 0 13 0 13 Plugging Totals 3.0 CERTIFICATIONS 3.1 Procedures/Examinations/Equipment 3.1.1 The examination and evaluation procedures used during the eddy current inspection were approved by personnel qualified to Level III in accordance with the 1984 Edition of the American Society for Nondestructive Testing (ASNT) Recommended Practice SNT-TC-1 A, "Personnel Qualification and Certification in Nondestructive Testing" and the 1991 and 1995 Editions of the American National Standards Institute (ANSI)/ASNT CP-189, "ASNT Standard for Qualification and Certification of Nondestructive Testing Personnel." Exelon Generation Company, LLC (EGG) procedure ER-AP-335-039, "Multifrequency Eddy Current Data Acquisition of Steam Generator TUbing," Revision 4 and EGC procedure ER-AP-335-040, Page 4 of 68
"Evaluation of Eddy Current Data for Steam Generator Tubing," Revision 3, were used for data acquisition and analysis.
3.1.2 The examinations, equipment, procedures and personnel were in compliance with the following requirements: the EGC and Westinghouse Quality Assurance Programs for Inservice Inspection; Byron Station Technical Specification 5.5.9; 2001 Edition through the 2003 Addenda of the ASME B&PV Code Section XI, "Rules for Inservice Inspection of Nuclear Power Plant Components"; 2001 Edition through the 2003 Addenda of the ASME B&PV Code Section V, "Nondestructive Examination"; Revision 6 of the EPRI PWR SG Examination Guidelines; and NEI 97-06, "Steam Generator Program Guidelines," Revision 2.
3.1 .3 Certification packages for examiners, data analysts, and equipment are available at Byron Station. Table A.1 and Table A.2 contained in Attachment A lists all personnel who performed, supervised, or evaluated the data during the current inspection.
3.1.4 Corestar International Corporation Model Omni-200' Remote Data Acquisition Units (RDAUs) with ANSER Version 8.4.3, Revision 299 software was used to acquire the eddy current data. Analysis was performed with Westinghouse ANSER Version 8.4.3, Revision 299 R
computer software and Corestar EddyVISION 32 Release 6.3 computer software.
3.1.5 The bobbin coil examinations were performed with a 0.560-inch diameter bobbin coil eddy current probe. A 0.540-inch diameter probe was used in Rows 1 through 8 where there was difficulty traversing the low radius U-bend region.
3.1.6 The special interest and dent/ding rotating coil examinations were performed with a 0.560-inch diameter three-coil rotating plus-point probe that contained a plus-point coil, a 0.115-inch diameter pancake coil and a 0.080-inch diameter pancake coil.
3.1.7 The rotating coil examinations in the U-Bend region were performed with a 0.520-inch diameter rotating plus-point probe.
3.2 Personnel 3.2.1 The personnel who performed the SG eddy current inspection data acquisition were qualified to Level II or Level I in accordance with the 1984 Edition of the ASNT Recommended Practice SNT-TC-1A, "Personnel Qualification and Certification in Nondestructive Testing" or the 1995 Edition of ANSI/ASNT CP-189, "ASNT Standard for Qualification and Certification of Nondestructive Testing Personnel." A list of certified eddy current personnel who performed data acquisition for the examination are contained in Table A.1 of Attachment A.
3.2.2 The personnel who performed the SG eddy current data analysis were qualified to a minimum of Level II, with special analysis training (i.e.,
Level IIA) in accordance with the 1984 Edition of the ASNT Page 5 of 68
Recommended Practice SNT-TC-1 A, "Personnel Qualification and Certification in Nondestructive Testing" or the 1995 Edition of ANSI/ASNT CP-189, "ASNT Standard for Qualification and Certification of Nondestructive Testing Personnel." A list of certified eddy current personnel who performed data analysis for the examination are contained in Table A.2 of Attachment A 3.2.3 All SG eddy current data analysts were qualified in accordance with EPRI Appendix G for QDA's. In addition, all data analysts were trained and tested in accordance with a site specific performance demonstration program in both the bobbin coil and plus-point inspection data analysis.
Resolution analysts were also trained and tested specifically for the performance of data resolution. All analysts were required to achieve a minimum probability of detection of 80% with a 90% minimum confidence level on practical examinations and a minimum score of 80% on the written test prior to analyzing data.
3.2.4 All SG eddy current data acquisition personnel were trained and tested in accordance with a site specific performance demonstration program.
The data acquisition operators were required to achieve a written test score of 80% or greater prior to acquiring data.
3.2.5 The SG eddy current analysis was subject to two independent analyses.
Primary analysis of all data was performed by personnel from Westinghouse Electric Company, Areva and HRID. Secondary analysis was performed by personnel from NDE Technology, Wiltec, Young Technology Services, Moretech and Anatec. Discrepancies between the two parties required Level III concurrence between both parties for the final resolution. Data Resolution was performed by personnel from Westinghouse, Master-Lee, Moretech and NDE Technologies.
3.2.6 Two independent SG eddy current Level III QDA's who were not part of the resolution team were employed to serve as a process control reviewer, in accordance with EPRI Guidelines, Sections 6.3.3 and 6.7.
The Independent Level III QDA randomly sampled the data to ensure the resolution process was properly performed and that the field calls were properly reported. The Independent Level III QDA also provided data acquisition oversight to ensure that the data collection process was in compliance with appropriate procedures, that all essential variables were set in accordance with the applicable Examination Technique Specification Sheet (ETSS) and to provide a data quality check of acquired data. The Independent Level III QDA reported directly to the EGC Nondestructive Examination Level III.
3.2.7 Personnel from Westinghouse Electric Company, Master-Lee and Hudson performed data acquisition.
3.2.8 Real time data quality verifications were performed by personnel qualified as data analysts.
Page 6 of 68
4.0 EXAMINATION TECHNIQUE AND EXAMINATION SCOPE All eddy current examination techniques used are qualified in accordance with Appendix H of the EPRI PWR SG Examination Guidelines. Each examination technique was evaluated to be applicable to the tubing and conditions of the Byron, Unit 1 SGs.
4.1 SG Tube Examination Techniques (TS 5.6.9.c) 4.1.1 The bobbin coil examinations were performed with a 0.560 inch diameter bobbin coil eddy current probe described in Section 3.1.5. For low row U-Bend regions in Rows 8 and lower, a 0.540-inch diameter bobbin probe was utilized where there was difficulty traversing the U-bend region. The nominal probe inspection speed was 40 inches per second for the 0.560-inch diameter probe and 24 inches per second for the 0.540-inch diameter probe and for the 0.560-inch probe in the low row tubes. Sufficient sampling rates were used to maintain a minimum of 30 samples per inch.
The bobbin coil probes were operated at frequencies of 650 kHz, 320 kHz, 160 kHz, and 35 kHz operating in the differential and absolute test modes.
In addition, suppression mixes were used to enhance the inspection.
These mixes were as follows: 650/160 kHz differential mix, a 320/160 kHz absolute mix, and a 650/320/160 kHz differential mix. The 650/320/160 kHz differential mix was used to aid in detection of foreign objects and foreign object wear.
4.1.2 The rotating coil and plus-point examinations were performed with a 0.560-inch diameter three-coil plus-point eddy current probe described in Section 3.1.6. The nominal probe speed was 0.4 inches per second in straight sections, and 0.1 inches per second for dents and dings. A sampling rate was used to maintain a minimum of 30 samples per inch in the circumferential direction and 25 samples per inch in the axial direction. For dents and dings, a sampling rate was used to maintain a minimum of 30 samples per inch in the circumferential direction and 30 samples per inch in the axial direction. The rotating probes were operated at frequencies of 300 kHz, 200 kHz, 100 kHz and 20 kHz. In addition to the four base frequencies, four process channels were used to display circumferential indications in the positive trace and to provide a suppression mix for indications at the lattice grid 4.1.3 The plus-point examinations in the U-bend regions were performed with a 0.520-inch diameter plus-point probe described in Section 3.1.7. The nominal probe speed was 0.3 inches per second. A sampling rate was used to maintain a minimum of 30 samples per inch in the circumferential direction and 25 samples per inch in the axial direction. The plus-point probe was operated at frequencies of 400 kHz, 300 kHz, 100 kHz, and 20 kHz. In addition to the four base frequencies, four process channels were used to display circumferential indications in the positive trace and to provide a suppression mix for indications at the fan bar support.
4.1.4 The eddy current calibration standards used for the bobbin coil and plus-point inspections met the requirements of Section 6.2.7 of the EPRI PWR Steam Generator Examination Guidelines, Revision 6 and Sections V and XI of the ASME B&PV Code, 2001 Edition through the 2003 Addenda.
Page 7 of 68
4.1.5 The SG eddy current examination techniques used during this inspection were equivalent to the EPRI Appendix H techniques listed in Table 4.1.
Each Examination Technique Specification Sheet (ETSS) was evaluated and determined to be applicable to the site conditions.
Table 4.1 EPRI A~ppend*IX H Tec h* n1ques EPRL' . ETSS. Probe Description" . .. ",'i " . ~ .. ",'
ETSS .
- Revision .' .... , .. '
96004.3 11 Bobbin Fan Bar Wear and Lattice Grid Wear Tube Support Plate (TSP) Outer Diameter Stress Corrosion 96008.1 14 Bobbin Cracking (ODSCC) 96010.1 7 Bobbin Small volume manufacturinq burnish marks in free span 96703.1 17 Plus-Point Dent/Dinq Axial PWSCC 96910.1 10 Plus-Point Support Plate Tapered Wear Flaw Sizing Expansion TransitionfTubesheet (TS) Bulge-Overexpansion 20510.1 7 Plus-Point Dent/Ding Circumferential PWSCC 20511.1 8 Plus-Point Expansion TransitionfTS Bulqe-Overexpansion Axial PWSCC 21409.1 5 Plus-Point Sludqe Pile/Crevice/Expansion Transition Axial ODSCC 21410.1 6 Plus-Point Expansion Transition/Dent/Ding Circumferential ODSCC 21998.1 4 Plus-Point Foreign Object Wear/Free Span Volumetric Indications 22401.1 4 Plus-Point Dent/Dinq Axial ODSCC 4.2 SG Tube Inspection Scope (TS 5.6.9.a) 4.2.1 100% of the tubes in all SGs were inspected full length, tube end to tube end, with a bobbin coil probe described in Section 4.1.1 above.
4.2.3 100% of the hot leg dents and dings that are ,2:2.0 volts were inspected with a plus-point probe described in Section 4.1.2. A total of 2 hot leg dings comprised the 100% hot leg dent/ding inspection population. One was in the 1A SG and the other was in the 1B SG.
4.2.4 Diagnostic examinations were conducted on the following types of indications and conditions using a rotating probe described in Section 4.1.2 and 4.1.3:
o Non-quantifiable indications that were detected by the bobbin coil examination o Tubes in the vicinity of potential foreign objects in order to determine the extent of tubes potentially affected by the objects.
o A 25% sample of new fan bar wear indications (25 total) o All new lattice grid wear indications (2 total)
A total of 116 tubes were inspected as a result of these diagnostic examinations.
4.2.5 Attachment B contains tube sheet maps indicating the tube inspections that were performed during Refueling Outage 15.
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4.3 Recording of Examination Data The raw eddy current data and analysis results were recorded on digital data storage media. The data was then loaded into the Westinghouse Eddy Current Data Management System, "ST Max," version 1.21.02. This system was used to track the proper examination of all tubes and it was also used to generate the final eddy current report summaries.
4.4 Witness and Verification of Examination Eddy current inspections were witnessed and/or verified by the Authorized Nuclear Inservice Inspectors, Mr. Jeff Hendricks and Mr. Lee Malabanan, of the Hartford Steam Boiler of CT of Hartford Connecticut, Chicago Branch, 2443 Warrenville Road, Suite 500, Lisle, Illinois 60532-9871.
The Refueling Outage 15 ASME Form NIS-1, "Owners Report for Inservice Inspections," is contained in Attachment D.
The Refueling Outage 15 ASME Form NIS-2, "Owner's Report for Repair/Replacement Activity" for steam generator mechanical tube plugging activities is contained in Attachment E.
5.0 EXAMINATION RESULTS 5.1 Indications Found (TS 5.6.9.b) 5.1.1 Fan Bar Wear - Tube degradation was found during the Refueling Outage 15 bobbin coil examination in the U-bend region due to fretting of the fan bar supports on the tube. A total of 146 indications in 125 tubes were reported. The EPRI Appendix H bobbin coil examination technique 96004.3 was utilized in this inspection for the depth sizing of fan bar wear.
No tubes exceeded the 40% TW repair limit and no tubes were plugged due to fan bar wear. The largest indication found was 20% through wall (TW) and was found in tube R86-C63 in SG 1B. The depth of the fan bar wear ranged from 1% TW to 20% TW. (Table 5.1.1 provides a summary of fan bar wear degradation. Attachment C provides a listing of all tube flaws containing measurable through wall depth and inservice indications, including fan bar wear.
Table 5.1.1 Refue rmgO uage t 15 Fan B ar Wear S ummary SGA SGB SGC SGD Indications Indications Indications Indications
<10% TW 15 55 16 33 10-19% TW 6 11 4 5
>= 20% TW 0 1 0 0 TOTAL
- 21 67 20 38 Page 9 of 68
5.1.2 Foreign Object Wear - There were no indications of foreign object wear detected during the Refueling Outage 15 inspection. See Section 5.2.3 for preventative plugging due to a non-retrievable foreign object with no associated tube wear.
5.1.3 Lattice Grid Wear - Three (3) tubes were found that contained indications of lattice grid wear. The depth of the lattice grid wear ranged from 4% TW to 10% TWas measured by the EPRI Appendix H qualified bobbin coil examination technique 96004.3. No tubes were plugged as a result of lattice grid wear. Table 5.1.3 below provides a summary of tubes that contain lattice grid wear.
TABLE 5.1.3 Refue rmgO utage 15 L attlce G n"d Wear S ummary Support NDE SG Row Column Location Depth 1B 118 73 07H 10%
10 51 8 08C 4%
10 117 78 07H 4%
5.2 Other SG Inspection Results 5.2.1 Hot Leg DenUDing Inspection: During Refueling Outage 15, 100% of the hot leg dents and dings 2: 2.0 volts were inspected with a three-coil rotating probe, which included a plus-point coil. A total of two tubes contained dings that met the inspection criteria and were inspected. No indication of degradation was found as a result of these inspections.
5.2.2 Visual Inspection of Installed Tube Plugs - All previously installed welded plugs and previously installed mechanical plugs were visually inspected for signs of degradation and leakage. A total of 2 welded plugs and 14 mechanical plugs were visually inspected. In addition, all plugs installed during this outage (i.e., 26 mechanical plugs in 13 tubes) were also visually inspected and the installation parameters were reviewed for acceptable installation. No anomalies were found.
5.2.3 Tubesheet Visual Inspection- Visual inspection of the secondary tubesheet was performed following sludge lancing activities in each SG. The tube annulus, tube lane, and peripheral tubes (6-8 tubes deep) were visually inspected for foreign material. A total of three foreign objects were found during these inspections. A machine turning was found in the 1BSG, a small drilling chip was found in the 10 G and a piece of gasket material was found in the 1C SG. The machine turning and drilling chip were successfully removed from the SG's. The gasket piece in the 1C SG was not retrieved and remains in the SG, following preventative tube plugging.
Page 10 of 68
Thirteen (13) tubes were preventatively plugged and stabilized that did not contain tube flaws or service induced degradation. The tubes were preventatively removed from service to surround a confirmed foreign object characteristic of gasket material that could not be removed from the 1C steam generator. The foreign object did not cause any tube damage. The object was initially detected by visual inspection. The thirteen tubes removed from service included additional tubes not directly adjacent to the foreign object, but were removed from service to ensure that if the object migrated out of the plugged tube box, the object would be in a lower flow velocity field to ensure any potential tube fretting would be acceptable over the next two operating cycles based on an evaluation. The evaluation considered tube vibration, flow conditions and the mass of the object.
Table 5.2.4-1 lists those tubes that were preventatively plugged and stabilized due to the non-retrievable object located on the secondary tubesheet.
Table 5.2.4-1 81 R15 Preventative Tube Plugging/Stabilizing For Forelan
" Ob".Iect-1C SG Row-Col Row-Col Row-Col 107-96 108-97 107-98 106-99 105-98 106-97 103-98 104-97 105-96 106-95 102-97 103-96 104-95 -- --
5.2.4 Attachment C contains tube lists with axial elevations of all tube flaws that contain measurable through wall depth and inservice indications that were found during the Refueling Outage 15 eddy current inspection (TS 5.6.9.d).
6.0 RESULTS OF CONDITION MONITORING (TS 5.6.9.9)
A condition monitoring assessment was performed for each inservice degradation mechanism found during the Refueling Outage 15 inspection. The condition monitoring assessment was performed in accordance with TS 5.5.9.a and NEI 97-06 using the EPRI Steam Generator Integrity Assessment Guidelines, Revision 2. For each identified degradation mechanism, the as-found condition was compared to the appropriate performance criteria for tube structural integrity, accident induced leakage and operational leakage as defined in TS 5.5.9.b. For each damage mechanism a tube structural limit was determined to ensure that SG tube integrity would be maintained over the full range of normal operating conditions and design basis accidents. This includes retaining a safety factor of 3.0 against burst under normal steady state full power operation primary to secondary pressure differential and a safety factor of 1.4 against burst under the limiting design basis accident pressure differential. The structural limit used was based upon 360 degree uniform wall thinning for infinite length assuming ASME Code minimum material properties. The structural limits provided below are conservative in that they assume 360 degree uniform wall thinning for the length of the tube.
Page 11 of 68
Satisfying this structural limit ensures that the SG tube integrity performance criteria for structural integrity, accident induced leakage and operational leakage will be maintained.
The as-found condition of each degradation mechanism found during Refueling Outage 15 was shown to meet the appropriate limiting structural integrity performance parameter with a probability of 0.95 at 50% confidence, including consideration of relevant uncertainties.
No tube pulls or in-situ pressure testing was performed or required during Refueling Outage 15.
Sections 6.1 through 6.3 provide a summary of the condition monitoring assessment for each degradation mechanism. Section 6.4 provides a primary to secondary leakage assessment.
6.1 Fan Bar Wear The largest fan bar wear indication found during the Refueling Outage 15 inspection was 20% TWas measured by the EPRI Appendix H qualified technique 96004.3, Revision 11. Considering technique and analyst uncertainties, the largest fan bar wear indication found is corrected to 28.1 % TW with a 0.95 probability at 50% confidence. This is well below the fan bar wear structural limit of 60% TW.
6.2 Lattice Grid Wear The largest lattice grid wear indication found during the Refueling Outage 15 inspection was 10% TWas measured by the EPRI Appendix H qualified technique 96004.3, Revision 11. Considering technique and analyst uncertainties, the largest lattice grid wear indication found is corrected to 18.5%
TW with a 0.95 probability at 50% confidence. This is well below the lattice grid wear structural limit of 60% TW.
6.3 Foreign Object Wear There were no indications of foreign object wear detected during the Refueling Outage 15 inspection. Therefore, condition monitoring performance criteria was met for foreign object wear. See Section 5.2.3 for preventative plugging due to a non-retrievable foreign object with no associated tube wear.
6.4 Primary-to-Secondary Leakage Assessment Byron Station Unit 1 did not observe any operational primary to secondary leakage greater than three gallons per day over the two operating cycles preceding the inspection. The SG tube inspections did not find any potential sources of tube leakage. Chemistry sampling of the Steam Jet Air Ejector and liquid SG blowdown sample locations did not detect any SG operational leakage that was above the detection threshold. Therefore, it was determined that there was no quantifiable SG operational leakage .
Page 12 of 68
- 7.0 REPAIR
SUMMARY
Repairs were conducted in accordance with ASME Section XI, 2001 Edition through the 2003 Addenda. All tube plugging was performed by Westinghouse using Alloy 690 mechanical tube plugging process in accordance with ASME Section XI IWA-4713, "Heat Exchanger Tube Plugging by Expansion." All repairs were performed in accordance with approved Westinghouse procedures. Table 7.1 depicts the repairs conducted during Refueling Outage 15. Table 7.2 lists the tube locations that were repaired in Refueling Outage 15. All tubes plugged during Refueling Outage 15 were associated with a non-retrievable foreign object located on the hot leg secondary tubesheet in the 1C SG.
TABLE 7.1 of Refuelin Outa e 15 Tube Plu
==~~!b====;=======u SG A SG SG C TOTA
===-I-======{===-==II o 0 13 13 Tubes Stabilized 0 0 13 13
- Includes number of tubes stabilized and plugged.
TABLE 7.2 SGTu b es Repalre dO unng . Refuermg O utage 15 Eddy Stabilizer Current No. SG Row Col Repair Leg Indication Comment 1 lC 102 97 Plug Hot Leg NOD Note 1 2 lC 103 96 PluQ Hot Leg NOD Note 1 3 1C 103 98 Plug Hot Leg NOD Note 1 4 1C 104 95 Plug Hot Leg NOD Note 1 5 lC 104 97 PluQ Hot Leg NOD Note 1 6 1C 105 96 Plug Hot Leg NOD Note 1 7 1C 105 98 Plug Hot Leg NOD Note 1 8 1C 106 95 PJuQ Hot Leg NOD Note 1 9 lC 106 97 Plug Hot Leg NOD Note 1 10 1C 106 99 Plug Hot Leg NOD Note 1 11 lC 107 96 PluQ Hot Leg NOD Note 1 12 1C 107 98 Plug Hot Leg NOD Note 1 13 1C 108 97 Plug Hot Leg NOD Note 1 NOD - No Degradation Detected Note 1: Tube was preventatively plugged to surround a non-retrievable foreign object located on the hot leg tubesheet in the 1C SG. There was no degradation associated with this foreign object.
8.0 DOCUMENTATION All original optical disks have been provided to EGC and are maintained at Byron Station.
The final data sheets and pertinent tube sheet plots are contained in the Westinghouse Page 13 of 68
Final Outage Reports for Byron Station, Unit 1, Refueling Outage 15 Steam Generator Inspection. The report is also maintained at Byron Station.
9.0 FIGURESrrABLES/ATTACHMENTS Attachment A Table A.1 Data Acquisition Personnel Certification List Table A.2 Data Analysis Personnel Certification List Figure A.1 Babcock & Wilcox Replacement Steam Generator Byron Unit 1 Configuration Figure A.2 Byron Station Unit 1 Steam Generator Tubesheet Configuration Attachment 8 Attachment B.1 Hot Leg Bobbin Coil Inspection Scope Attachment B.2 Cold Leg Bobbin Coil Inspection Scope Attachment B.3 Special Interest Plus-Point Inspection Scope, Including Hot Leg Dents and Dings Attachment C Attachment C.1 1A Steam Generator Inservice Indications Attachment C.2 1B Steam Generator Inservice Indications Attachment C.3 1C Steam Generator Inservice Indications Attachment CA 1D Steam Generator Inservice Indications Attachment D ASME Form NIS-1, "Owners Report for Inservice Inspections" Attachment E ASME Form NIS-2, "Owners Report for Repair/Replacement Activity" for 1C SG Tube Plugging Page 14 of 68
ATTACHMENT A PERSONNEL CERTIFICATIONS BABCOCK & WILCOX REPLACEMENT STEAM GENERATOR BYRON UNIT 1 CONFIGURATION Page 15 of 68
TABLE A.1 DATA ACQUISITION PERSONNEL CERTIFICATIONS I No. Name Company Level aDA 1 Bradley, G Westinghouse No 2 Chiplaskey, G Westinghouse No 3 Despaux,C Westinghouse No 4 Evering, D Westinghouse No 5 Gault, W Westinghouse No 6 Lopez, P Hudson No 7 Miller, G Westinghouse No 8 Schachte, D Westinghouse f No 9 Scott, A Westinghouse II No 10 Shaffer, E Master-Lee IIA No 11 Taylor, A Westinghouse I No 12 Taylor, C Hudson II No 13 Walsh, M Westinghouse II No Page 16 of 68
TABLE A.2 DATA ANALYSIS PERSONNEL CERTIFICATIONS No. Name Company Level aDA 1 Alspaugh, K NDE Technology IliA aDA 2 Bernasson, R Wiltec lilA aDA 3 Bowler, S Young Technical IIA aDA 4 "Brown, M NDE Technology lilA aDA 5 Case, J NDE Technology lilA aDA 6 Cvitanovic, N HRID IIA aDA 7 Desflaches, M Westinghouse IIA aDA 8 Dlabik, A Master-Lee IliA aDA 9 Dzapo, M HRID IIA aDA 10 Funanich, J MoreTech III aDA 11 Herold, M Infineddy IIA aDA 12 Ingenthron, J Infineddy IIA aDA 13 Jones,B MoreTech III aDA 14 Kocher, J Master-Lee IliA aDA 15 Kolakowski, C Westinghouse IIA aDA 16 Lareau, K Areva III aDA 17 Lewis, C NDE Technology IIA aDA 18 Lynn, V Master-Lee lilA aDA 19 Maullar, K Wi/tee lilA aDA 20 Mingus, 0 MoreTech IIA aDA 21 Munk, R HRID IIA aDA 22 Obazenu,D Anatec III aDA 23 Popovich, R Westinghouse III aDA 24 Ready, S Anatec IIA aDA 25 Rengel, A HRID IIA aDA 26 Ribaric, T Areva III aDA 27 Schmitz, K NDE Technology lilA aDA 28 "Siegel, R NDE Technology IliA aDA 29 Skirpan, J NDE Technology IIA aDA 30 Terning, G Westinghouse III aDA 31 Tolentino, E Westinghouse IIA aDA 32 Webb, M MoreTech IIA aDA 33 Zerovnik, V HRID IIA aDA
- Independent Qualified Data Analyst Page 17 of 68
FIGURE A.I Babcock & \Vilcox Replacement Steam Generator Byron Unit 1 Configuration STEAH OUTLET NOZZLE:
SE: CONOARY OE:a(
CAP-3 PRlHAAY PRIKARY SEPAAATOOS DECK AltA I LLl MY FEEO\-lATER FEEOl-I.... TER NOZZLE NOZZLE FLAT BAR U-BENO RESTRAINTS REC I RCUJ, T i 0.'-1 NOZZLE FEEO\-lATER HEADER I_
I
! - LATTICE GRID TUBE SUPPORTS (TYP)
LATT ICE GRID INSPECTION PORTS (TYP)
TlBE:SHEET HAk'OHOLE Page 18 of 68
FIGtJRE A.2 Byron Unit I Steam Generator Tuheshcct Configuration (Typical) 10 15 2() 25 30 lS 40 45 50 5S GO G~Yr.on15 St8?ti~n 90U~~T: 11 105S~; luf\ 126 125 130 m 140 us 115
!l6 110 loS J.",_,_~_.._.._ ... _.<---+-+- I I -+----1---.----.. - - 105 II)(} - - - -*.*- 100 j!i -_.- 95 If) --'l>
\J co OJ CD lS --85 16 . _ l -_ _ ._+ 80
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<:t16 15 10 10 15 20 25 10 ,15 40 45 50 55 co 65 70 15 90 90 95 100 165 110 11S 120 IZS 130 US 140}
MANWAY Database: BYRONI Model: 7720 INLET NOZZLE
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o Ol1r<ltl1l Tuba £633 100.00 Daf""lt Slay 6