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Category:Inservice/Preservice Inspection and Test Report
MONTHYEARL-2023-103, Inservice Inspection Examination Report2023-08-0303 August 2023 Inservice Inspection Examination Report L-2023-023, Revised Steam Generator Tube Inspection Report2023-03-0303 March 2023 Revised Steam Generator Tube Inspection Report SBK-L-22036, Steam Generator Tube Inspection Report2022-04-25025 April 2022 Steam Generator Tube Inspection Report SBK-L-22003, Inservice Inspection Examination Report2022-01-24024 January 2022 Inservice Inspection Examination Report SBK-L-21126, Fourth 10 Year Interval - Inservice Inspection (ISI) Program Plan2022-01-0404 January 2022 Fourth 10 Year Interval - Inservice Inspection (ISI) Program Plan SBK-L-20132, Fourth Interval Inservice Testing (IST) Program2020-10-21021 October 2020 Fourth Interval Inservice Testing (IST) Program SBK-L-20103, Inservice Inspection Examination Report2020-07-27027 July 2020 Inservice Inspection Examination Report SBK-L-19052, Steam Generator Tube Inspection Report2019-04-19019 April 2019 Steam Generator Tube Inspection Report SBK-L-19001, Inservice Inspection Examination Report2019-01-24024 January 2019 Inservice Inspection Examination Report SBK-L-17166, Generator Tube Inspection Report2017-10-17017 October 2017 Generator Tube Inspection Report SBK-L-17117, Inservice Inspection Examination Report2017-07-18018 July 2017 Inservice Inspection Examination Report SBK-L-16100, Inservice Testing Program for the Third 10-Year Interval2016-07-21021 July 2016 Inservice Testing Program for the Third 10-Year Interval SBK-L-16015, Inservice Inspection Examination Report2016-02-10010 February 2016 Inservice Inspection Examination Report SBK-L-14119, Inservice Inspection Examination Report2014-06-14014 June 2014 Inservice Inspection Examination Report SBK-L-13019, Inservice Inspection Examination Report2013-01-28028 January 2013 Inservice Inspection Examination Report SBK-L-11197, Request for Alternative to Use ASME Code Case N-716 to Implement Risk-Informed Inservice Inspection Program2011-11-0707 November 2011 Request for Alternative to Use ASME Code Case N-716 to Implement Risk-Informed Inservice Inspection Program SBK-L-11191, Third Ten-Year Interval Inservice Inspection Relief Requests2011-09-26026 September 2011 Third Ten-Year Interval Inservice Inspection Relief Requests SBK-L-11170, Inservice Inspection Examination Report2011-08-11011 August 2011 Inservice Inspection Examination Report SBK-L-11132, Submittal of Third Ten-Year Interval Inservice Inspection and Second Ten-Year Containment Inservice Inspection Program2011-06-22022 June 2011 Submittal of Third Ten-Year Interval Inservice Inspection and Second Ten-Year Containment Inservice Inspection Program SBK-L-10027, Inservice Inspection Examination Report for Inspections Conducted Prior to and During the Thirteenth Refueling Outage That Concluded on November 12, 20092010-02-0909 February 2010 Inservice Inspection Examination Report for Inspections Conducted Prior to and During the Thirteenth Refueling Outage That Concluded on November 12, 2009 ML0929201562009-10-0707 October 2009 Seabrook Station - 10 CFR 50.55a Request 2AR-07, Second Interval ISI Program Category B-P Exams - 10-Year Class 1 System Leakage Test SBK-L-09122, Response to Request for Additional Information Regarding a Request for Relief from Inservice Inspection Requirements2009-05-27027 May 2009 Response to Request for Additional Information Regarding a Request for Relief from Inservice Inspection Requirements SBK-L-09038, Supplement to Request for Relief from Inservice Inspection Requirements2009-02-24024 February 2009 Supplement to Request for Relief from Inservice Inspection Requirements SBK-L-08135, Inservice Inspection Examination Report for Inspections Conducted Prior to and During the Twelfth Refueling Outage2008-07-21021 July 2008 Inservice Inspection Examination Report for Inspections Conducted Prior to and During the Twelfth Refueling Outage SBK-L-07088, Steam Generator Inservice Inspection2007-05-23023 May 2007 Steam Generator Inservice Inspection SBK-L-07024, Inservice Inspection Examination Report, for Inspections Conducted Prior to and During the Eleventh Refueling Outage That Concluded on November 10, 20062007-02-0202 February 2007 Inservice Inspection Examination Report, for Inspections Conducted Prior to and During the Eleventh Refueling Outage That Concluded on November 10, 2006 SBK-L-05145, Inservice Inspection Examination Report2005-07-29029 July 2005 Inservice Inspection Examination Report SBK-L-04040, Steam Generator Inservice Inspection2004-10-12012 October 2004 Steam Generator Inservice Inspection ML0403601082004-02-18018 February 2004 Review of Steam Generator Tube Inservice Inspection Report for the 2002 Refueling Outage ML0403706262004-01-29029 January 2004 Transmittal of Inservice Inspection Examination Report ML0331804642003-11-0303 November 2003 Steam Generator Tubes Plugged During Ninth Inservice Inspection ML0327314152003-09-23023 September 2003 Revision to Inservice Test Program Relief Request PR-3 ML0312200282003-04-24024 April 2003 Generator Inservice Inspection ML0225500502002-08-29029 August 2002 Inservice Inspection Examination Report 2023-08-03
[Table view] Category:Letter type:SBK
MONTHYEARSBK-L-23053, Radiological Emergency Plan (Ssrep), Revision 802023-06-22022 June 2023 Radiological Emergency Plan (Ssrep), Revision 80 SBK-L-23031, 2022 Annual Radioactive Effluent Release Report2023-04-28028 April 2023 2022 Annual Radioactive Effluent Release Report SBK-L-23044, 2022 Annual Radiological Environmental Operating Report2023-04-28028 April 2023 2022 Annual Radiological Environmental Operating Report SBK-L-23033, 2022 Annual Environmental Operating Report2023-04-11011 April 2023 2022 Annual Environmental Operating Report SBK-L-22093, 75 Day and 150 Day Submittal Letters2022-12-0101 December 2022 75 Day and 150 Day Submittal Letters SBK-L-22113, Radiological Emergency Plan (Ssrep), Revision 792022-11-16016 November 2022 Radiological Emergency Plan (Ssrep), Revision 79 SBK-L-22114, Independent Spent Fuel Storage Installation (Isfsi), Cask Registration2022-11-0909 November 2022 Independent Spent Fuel Storage Installation (Isfsi), Cask Registration SBK-L-22112, Independent Spent Fuel Storage Installation (ISFSI) Cask Registration2022-11-0303 November 2022 Independent Spent Fuel Storage Installation (ISFSI) Cask Registration SBK-L-22094, Relief Request 4RA-22-001, Proposed Alternative in Accordance with 10 CFR 50.55a(z)(2)2022-10-26026 October 2022 Relief Request 4RA-22-001, Proposed Alternative in Accordance with 10 CFR 50.55a(z)(2) SBK-L-22105, Supplement to 2021 Annual Radioactive Effluent Release Report2022-10-24024 October 2022 Supplement to 2021 Annual Radioactive Effluent Release Report SBK-L-22103, 5 to the Physical Security Plan, Training and Qualification Plan and Safeguards Contingency Plan2022-10-12012 October 2022 5 to the Physical Security Plan, Training and Qualification Plan and Safeguards Contingency Plan SBK-L-22102, Independent Spent Fuel Storage Installation (ISFSI) Cask Registration2022-10-0606 October 2022 Independent Spent Fuel Storage Installation (ISFSI) Cask Registration SBK-L-22080, Submittal of 10 CFR 72.48 Report of Changes, Tests and Experiments for August 2020 to July 20222022-08-12012 August 2022 Submittal of 10 CFR 72.48 Report of Changes, Tests and Experiments for August 2020 to July 2022 SBK-L-22054, SBK-L-22054 - License Amendment Request 22-01, Application to Revise Technical Specifications to Adopt TSTF-577, Revised Frequencies for Steam Generator Tube Inspections2022-06-0909 June 2022 SBK-L-22054 - License Amendment Request 22-01, Application to Revise Technical Specifications to Adopt TSTF-577, Revised Frequencies for Steam Generator Tube Inspections SBK-L-22044, 2021 Annual Radioactive Effluent Release Report2022-04-29029 April 2022 2021 Annual Radioactive Effluent Release Report SBK-L-22036, Steam Generator Tube Inspection Report2022-04-25025 April 2022 Steam Generator Tube Inspection Report SBK-L-22040, Radiological Emergency Plan (Ssrep), Revision 7822022-04-20020 April 2022 Radiological Emergency Plan (Ssrep), Revision 782 SBK-L-22024, Response to Request for Additional Information (Raj) Regarding License Amendment Request 21-01, Revise 120-Volt AC Vital Instrument Panel Requirements2022-03-0707 March 2022 Response to Request for Additional Information (Raj) Regarding License Amendment Request 21-01, Revise 120-Volt AC Vital Instrument Panel Requirements SBK-L-22003, Inservice Inspection Examination Report2022-01-24024 January 2022 Inservice Inspection Examination Report SBK-L-21126, Fourth 10 Year Interval - Inservice Inspection (ISI) Program Plan2022-01-0404 January 2022 Fourth 10 Year Interval - Inservice Inspection (ISI) Program Plan SBK-L-21135, Submittal of Changes to the Seabrook Station Technical Specification Bases2021-12-29029 December 2021 Submittal of Changes to the Seabrook Station Technical Specification Bases SBK-L-21108, Core Operating Limits Report for Cycle 222021-11-0404 November 2021 Core Operating Limits Report for Cycle 22 SBK-L-21106, Transmittal of WCAP-18607-NP, Analysis of Capsule X from the NextEra Energy Seabrook Unit 1 Reactor Vessel Radiation Surveillance Program2021-09-30030 September 2021 Transmittal of WCAP-18607-NP, Analysis of Capsule X from the NextEra Energy Seabrook Unit 1 Reactor Vessel Radiation Surveillance Program SBK-L-21105, Withdrawal of Emergency License Amendment Request 21-02, Service Water System I Ultimate Heat Sink One-Time Allowed Outage Time (AOT) Extension2021-09-27027 September 2021 Withdrawal of Emergency License Amendment Request 21-02, Service Water System I Ultimate Heat Sink One-Time Allowed Outage Time (AOT) Extension SBK-L-21103, Request for Exercise of Enforcement Discretion2021-09-25025 September 2021 Request for Exercise of Enforcement Discretion SBK-L-21104, Emergency License Amendment Request 21-02, Service Water System I Ultimate Heat Sink Onetime Allowed Outage Time (AOT) Extension2021-09-25025 September 2021 Emergency License Amendment Request 21-02, Service Water System I Ultimate Heat Sink Onetime Allowed Outage Time (AOT) Extension SBK-L-21098, Supplement to License Amendment Request 21-01, Revise 120-Volt AC Vital Instrument Panel Requirements2021-09-22022 September 2021 Supplement to License Amendment Request 21-01, Revise 120-Volt AC Vital Instrument Panel Requirements SBK-L-21083, NextEra Energy Seabrook, LLC - Relief Request 3IR-18 and 3IR-19 for End of Third 10-Year ISI Interval for Examinations with Limited Coverage2021-08-18018 August 2021 NextEra Energy Seabrook, LLC - Relief Request 3IR-18 and 3IR-19 for End of Third 10-Year ISI Interval for Examinations with Limited Coverage SBK-L-21067, License Amendment Request 21-01, Revise 120-Volt AC Vital Instrument Panel Requirements2021-07-21021 July 2021 License Amendment Request 21-01, Revise 120-Volt AC Vital Instrument Panel Requirements SBK-L-21049, Revision to Updated Final Response to NRC Generic Letter 2004-022021-06-24024 June 2021 Revision to Updated Final Response to NRC Generic Letter 2004-02 SBK-L-21056, Response to Request for Additional Information Regarding Seabrook Steam Generator Tube Inspection Report Review References:2021-05-20020 May 2021 Response to Request for Additional Information Regarding Seabrook Steam Generator Tube Inspection Report Review References: SBK-L-21045, Submittal of 2020 Annual Radioactive Effluent Release Report2021-04-30030 April 2021 Submittal of 2020 Annual Radioactive Effluent Release Report SBK-L-21044, 2020 Annual Radiological Environmental Operating Report2021-04-30030 April 2021 2020 Annual Radiological Environmental Operating Report SBK-L-21042, Response to RIS 2021-01 Preparation and Scheduling of Operator Licensing Examinations2021-04-22022 April 2021 Response to RIS 2021-01 Preparation and Scheduling of Operator Licensing Examinations SBK-L-21033, Response to Request for Additional Information (RAI) Regarding License Amendment Request (LAR) 20-02, Resolve Non-Conservative Heat Flux Hot Channel Factor (Fo(Z)) Requirements2021-03-24024 March 2021 Response to Request for Additional Information (RAI) Regarding License Amendment Request (LAR) 20-02, Resolve Non-Conservative Heat Flux Hot Channel Factor (Fo(Z)) Requirements SBK-L-21023, Radiological Emergency Plan (Ssrep), Revision 772021-03-0404 March 2021 Radiological Emergency Plan (Ssrep), Revision 77 SBK-L-20154, Submittal of Changes to the Seabrook Station Technical Specification Bases2020-12-22022 December 2020 Submittal of Changes to the Seabrook Station Technical Specification Bases SBK-L-20149, Response to Request for Additional Information in Respect to One-Time Exemption from 10 CFR 73, Appendix B, Section VI, Subsection C.3.(I)(1) Regarding Annual Force-on-Force (FOF) Exercises, Due to Covid 19 Pandemic2020-12-0808 December 2020 Response to Request for Additional Information in Respect to One-Time Exemption from 10 CFR 73, Appendix B, Section VI, Subsection C.3.(I)(1) Regarding Annual Force-on-Force (FOF) Exercises, Due to Covid 19 Pandemic SBK-L-20146, One-Time Exemption Request for the Biennial Emergency Preparedness Exercise Requirements of 10 CFR 50, Appendix E. IV.F.2.b and IV.F.2.c2020-12-0303 December 2020 One-Time Exemption Request for the Biennial Emergency Preparedness Exercise Requirements of 10 CFR 50, Appendix E. IV.F.2.b and IV.F.2.c SBK-L-20144, Request for a One-Time Exemption from 10 CFR 73, Appendix B, Section VI Subsection C.3.(1)(1) Regarding Annual Force-on-Force (FOF) Exercises, Due to Covid 19 Pandemic2020-11-23023 November 2020 Request for a One-Time Exemption from 10 CFR 73, Appendix B, Section VI Subsection C.3.(1)(1) Regarding Annual Force-on-Force (FOF) Exercises, Due to Covid 19 Pandemic SBK-L-20143, Withdrawal of Exemption Request Supporting Updated Final Response to NRC Generic Letter 004-022020-11-19019 November 2020 Withdrawal of Exemption Request Supporting Updated Final Response to NRC Generic Letter 004-02 SBK-L-20132, Fourth Interval Inservice Testing (IST) Program2020-10-21021 October 2020 Fourth Interval Inservice Testing (IST) Program SBK-L-20127, Generator Tube Inspection Report2020-10-20020 October 2020 Generator Tube Inspection Report SBK-L-20117, Response to Request for Additional Information Regarding Technical Specification 3/4.8.1 for a One-Time Extension of Allowed Outage Time License Amendment Request2020-09-23023 September 2020 Response to Request for Additional Information Regarding Technical Specification 3/4.8.1 for a One-Time Extension of Allowed Outage Time License Amendment Request SBK-L-20103, Inservice Inspection Examination Report2020-07-27027 July 2020 Inservice Inspection Examination Report SBK-L-20092, Response to Request for Additional Information Regarding License Amendment Requests to Adopt TSTF-411 and TSTF-4182020-07-13013 July 2020 Response to Request for Additional Information Regarding License Amendment Requests to Adopt TSTF-411 and TSTF-418 SBK-L-20068, License Amendment Request 20-01, One-Time Change to the Seabrook Technical Specifications A.C. Sources - Operating2020-07-13013 July 2020 License Amendment Request 20-01, One-Time Change to the Seabrook Technical Specifications A.C. Sources - Operating SBK-L-20085, Supplement to Exemption Request for Access Authorization and Fitness for Duty Requirements Due to COVID-19 Pandemic2020-06-16016 June 2020 Supplement to Exemption Request for Access Authorization and Fitness for Duty Requirements Due to COVID-19 Pandemic SBK-L-20077, Core Operating Limits Report for Cycle 212020-06-0101 June 2020 Core Operating Limits Report for Cycle 21 SBK-L-20057, Response to Request for Additional Information Regarding Degraded Voltage Time Delay Setpoint License Amendment Request2020-05-20020 May 2020 Response to Request for Additional Information Regarding Degraded Voltage Time Delay Setpoint License Amendment Request 2023-06-22
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FPL Energy Seabrook Station P.O. Box 300 FPL Energy Seabrook, NH 03874 Seabrook Station (603) 773-7000 May 23, 2007 Docket No. 50-443 SBK-L-07088 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555-0001 Seabrook Station Steam Generator Jnservice Inspection FPL Energy Seabrook, LLC encloses pursuant to Seabrook Station Technical Specification Surveillance Requirement 4.4.5.5b, a report documenting the results of inservice inspections conducted on the Steam Generators during the eleventh refueling outage that occurred in October 2006.
Should you require further information regarding this matter, please contact Mr. Michael Ossing, Manager of Engineering Support, at (603) 773-7512.
Very truly yours, FPL Energy Seabrook, LLC Gene St. Pierrese Site Vice President cc:
S. J. Collins, NRC Region I Administrator G. E. Miller, NRC Project Manager, Project Directorate 1-2 W. J. Raymond, NRC Senior Resident Inspector an FPL Group company 4C)147
ENCLOSURE TO SBK-L-07088 Steam Generator 12 Month Inservice Inspection Report 1.0 Introduction In October 2006, FPL Energy, Seabrook LLC (Seabrook Station) eleventh refueling outage, Steam Generators (SGs) A, B, C, and D were inspected. This was accomplished in accordance with Seabrook Station Technical Specification 4.4.5. This report presents the results of the inspection pursuant to Technical Specification 4.4.5.5.b. and NEI 97-06.
Seabrook Station is a Westinghouse four-loop pressurized water reactor with Model F steam generators.
The generators are U-bend heat exchangers, with tube bundles fabricated using thermally treated alloy 600 tubing. A row and column number identifies each tube. There are 59 rows and 122 columns in each steam generator, for a total of 5,626 tubes. Nominal tube OD is 0.688" with a 0.040" nominal wall thickness.
The EPRI Steam Generator Examination Guidelines, Revision 6, defines the required inspection periods and their duration. For alloy 600TT tubing, the first inspection interval is up to 120 Effective Full Power Months (EFPM); the second inspection interval is 90 EFPM; the third and subsequent inspection intervals are 60 EFPM. OR 1I is the approximate mid-point of the second inspection interval (90 EFPM) at Seabrook Station. The requirement to complete inspection of 50% of the tubes by the mid-point of the inspection interval is met by the inspections performed at ORI 1.
2.0 Scope of Inspections Performed The inspection program required by Seabrook Station Technical Specifications and the EPRI Steam Generator Examination Guidelines, Revision 6, addresses the known degradation mechanisms observed in Seabrook in prior inspections as well as those regarded as relevant and potential degradation mechanisms. The defined scope implemented in all 4 SGs during ORI 1 included the following, the percentages indicating the approximate inspection sample needed to satisfy the mid-period requirements of EPRI Steam Generator Examination Guidelines, Revision 6:
0 100% Bobbin examination of tubes, full length except for Rows 1 and 2, which are inspected with the bobbin from tube end to TSP#7 on both Hot Leg (HL) and Cold Leg (CL).
0 30% of the U-bends in each of Rows 1 and 2 with + Point.
- 30% HL Top of Tube Sheet (TTS), +/- 3", mid-range + Point examination to complete 50% with tubes examined in OR09.
- 30% Dings and Dents > 5 Volts: HL dings/dents with the mid-range +Point probe. The HL includes the U-bend to just above the top TSP on the CL.
0 50% sample of the hot leg tubesheet expansion zone bulges (BLG) and overexpansions (OXP) in the region from the TTS to the TTS-17"; mid-range +Point examination.
Special interest, mid-range +Point tests at hot leg and cold leg bobbin possible flaw locations (including U-bends), including all "I-code" indications that were new or not resolved after history review.
- Visual inspection of mechanical and weld plugs.
- +Point inspection to bound the tubes exhibiting possible loose parts (PLP) signals during the inspection.
The NRC granted Seabrook Station a one-time technical specification change that effectively changed the definition of where a steam generator tube starts in the tube sheet. This allowed the inspection program to not consider or inspect the portion of the steam generator tubing below 17 inches from the top of the tubesheet on the hot leg side.
Inspection Expansion No expansion of the inspection plan was required. For Anti-Vibration Bar (AVB) wear, a 100%
inspection of the affected tubes was performed in the base bobbin program. No other operational degradation was detected that required expansion of the inspection sample.
3.0 Active Degradation Mechanisms The EPRI Steam Generator Examination guidelines Revision 6 define "Active Damage Mechanism" as:
(1) A combination of 10 or more new indications of degradation (> 20% through-wall distance
[TWD]) of thinning, pitting, wear (excluding loose part wear), or impingement and previous indications that display an average growth rate > 25% of the repair limit in one inspection-to-inspection interval in any one SG.
(2) Alternatively, the existence of 1 or more new or previously identified indications (>20% through-wall) which display a growth > the repair limit in one inspection-to-inspection interval.
(3) Any crack indication (outside diameter intergranular attack/stress corrosion cracking or primary side corrosion cracking).
There are no active degradation mechanisms in any of the Seabrook SGs. However, AVB wear is clearly an ongoing (relevant) degradation mechanism. Based on the above definitions of an active degradation mechanism, for AVB wear to be an active degradation mechanism, a combination of at least ten or more new indications greater than 20%TWD and/or previously detected indication with growth rates greater than 10% would be required.
4.0 NDE Techniques for Damage Mechanisms The NDE (Non Destructive Examination) techniques used met the applicable industry guidance and were qualified, also in accordance with applicable industry guidance, for site specific use.
5.0 Pluein2 Twenty-one tubes were plugged during OR 1I at Seabrook. Table 1 lists the plugged tubes and summarizes what the degradation is attributed to. No tubes were plugged in SG-A. In SG-B, a tube that was identified after restart after OR09 with potentially elevated residual stress was administratively plugged. This tube was inspected prior to plugging and was found free of any degradation. In SGs C and D, several tubes were plugged for AVB wear that exceeded the 40% TWD Technical Specification plugging limit. Other tubes with significant AVB wear were examined for unusual wear patterns and growth rates; none was judged to have growth rates or wear patterns that indicated administrative plugging was warranted.
In SG-C, two tubes were identified initially with possible loose part (PLP) signals in an area that could not be accessed for removal of the foreign object. These tubes exhibited wear signal suggesting that the foreign object was still present; therefore they were plugged. The 14 un-degraded tubes surrounding the tubes were also plugged to create a conservative boundary for the degraded tubes.
In SG-D, a tube was plugged with a volumetric (wear) indication below the 6 th TSP that was sized at 40% TWD using ETSS 29881. The location was bounded by +Point examination; no foreign objects were detected in any of the surrounding tubes.
Table 1 Steam Generator Tube Plugging in ORl 1 SG Tube Attribution Notes A none NA NA B R27C97 Administrative Tube with potentially high residual stress R51 C69 AVB Wear 44% TWD at AVB5 C R51C45 AVB Wear 42% TWD at AVB3 R58C54 Foreign Object. Wear DSI,PLP,SVI,PCT 39% @ O1C+0.51 R59C57 Foreign Object. Wear DSI, SVI, PCT 48%
R58C55 Administrative PLP Box R59C55 Administrative PLP Box R57C56 Administrative PLP Box R58C56 Administrative PLP Box R59C56 Administrative PLP Box R57C57 Administrative PLP Box R58C57 Administrative PLP Box R57C58 Administrative PLP Box R58C58 Administrative PLP Box R59C58 Administrative PLP Box R57C55 Administrative PLP Box R57C53 Administrative PLP Box R58C53 Administrative PLP Box R57C54 Administrative PLP Box D R52C44 AVB Wear 41% TWD at AVB4 R11C102 Volumetric SVI @ 06C-0.74; 40%TWD Note: SVI Single Volumetric Indication PLP Possible Loose Part DSI Distorted Support Indication PCT Percent TWD Though Wall Distance AVB Anti-Vibration Bar The following table (table 2) shows the total number of tubes plugged by steam generator and the effective percentage plugged in each steam generator as well as total tubes plugged and total effective plugging percentage.
Table 2 Total Tubes Plugged and Plugging Percentage S/G A S/G B S/G C S/G D Total Tubes Plugged 31 24 46 60 161 Percent lugged 0.55% 0.43% 0.81% 1.07% 0.72%
6.0 Condition Monitoring Assessment Results.
All indications found in OR 1I satisfy the condition monitoring requirements of NEI 97-06 for structural and leakage integrity. No indications were found to exceed structural limits. These conclusions are based on the evaluations included in this report and summarized below:
- 1. Based on the OR11 inspection results, the Seabrook Station steam generators currently meet all of the performance criteria as specified in NEI 97-06, Revision 2, "Steam Generator Program Guidelines."
- 2. No indications of cracking were observed at any location in all four SGs.
- 3. The maximum observed AVB wear indication (44% TWD) meets the structural requirements of draft Reg. Guide 1.121 when the NDE uncertainties 5.3% at 95% CL (based on the use of a 0/20/40 standard) for AVB wear sizing are added to the observed wear depths.
- 4. AVB wear, classified as a relevant (on-going) degradation mechanism in all four SGs in the pre-outage degradation assessment, is not an active degradation mechanism in any of the SGs based on the OR 1I results. The overall incidence of AVB wear in the Seabrook SGs is consistent with the Model F SG operating experience.
- 5. The previously reported wear at the flow distribution baffle (FDB) was reported again during OR11 at Seabrook. Examination of the prior inspection signals shows that the signals are not changing. FDB wear is attributed to the application of pressure pulse cleaning of the SGs and is observed in other Model F SGs at the same locations and depths. The magnitude of the wear does not challenge the requirements for condition monitoring.
- 6. Volumetric (wear) indications meet the requirements for Condition Monitoring at 95%
probability and 50% confidence. The maximum observed indication was 40% TWD.
- 7. Wear due to foreign objects meets the performance requirements for Condition Monitoring. The maximum wear observed due to foreign objects was 48% TWD; the structural limit for the local wear is 75%. The 95/50 evaluation of the observed wear flaw shows that the requirements for condition monitoring are met.
- 8. No pitting was observed.
- 9. No degradation indications were observed related to potential precursor signals such as dents and dings, or to interference such as permeability variations, etc.
- 10. No degradation was observed in the tubesheet expansion zone during the BLG/OXP program from the TTS to -17 inches.