ML15160A414

From kanterella
Revision as of 00:17, 1 July 2018 by StriderTol (talk | contribs) (Created page by program invented by StriderTol)
Jump to navigation Jump to search
NYS000546 - Slides, Nrc/Epri Steam Generator Task Force Meeting (February 12, 2015)
ML15160A414
Person / Time
Site: Indian Point  Entergy icon.png
Issue date: 02/12/2015
From:
State of NY, Office of the Attorney General
To:
Atomic Safety and Licensing Board Panel
SECY RAS
References
RAS 27915, ASLBP 07-858-03-LR-BD01, 50-247-LR, 50-286-LR
Download: ML15160A414 (59)
v • d • e


Text

© 2015 Electric Power Research Institute, Inc. All rights reserved.NRC / EPRI Steam Generator Task Force Meeting February 12, 2015 2© 2015 Electric Power Research Institute, Inc. All rights reserved.Agenda8:30 am IntroductionsNRC and IndustryOpening RemarksNRC and IndustryEPRI SGMP Steam Generator Task Force Update(Industry)Open Technical IssuesNoise MonitoringGeneral Discussion ItemsSan OnofreLessons LearnedTubesheet Joint DesignSteam Generator Requirements in ASME CodeAuto Analysis Workshop Thermal Heat Treatment of TubingAction Levels for Leakage Status of Adopting TSTF

-510 3© 2015 Electric Power Research Institute, Inc. All rights reserved.AgendaGeneral Discussion Items (continued)Consistent Measuring of Flaw AmplitudeBasis for Section D3.1 of In Situ Pressure Test GuidelinesAnti-vibration Bar Position Verification10:00 am Break10:20 am StandingDiscussion Topics(Industry)Summary of Recently Issued SGMP Technical ReportsStatus of Industry GuidelinesInterim GuidanceNEI 03-08 DeviationsRecent Steam Generator Operating ExperienceFeedwaterSupport Generic Implications11:20 am NRC Discussion / Items of Interest(NRC)Issues Discussed in Past (Monitoring)Tube-to-Tubesheet Weld and Divider Plate Cracking Report11:45amAddress Public Questions/Comments(NRC)12:00pm Adjourn 4© 2015 Electric Power Research Institute, Inc. All rights reserved.Open Technical Issues

-SGTFNoise MonitoringRecommendations have been provided to the Examination Guidelines Revision 8 Committee and the Integrity Assessment Revision 4 CommitteeNew appendix has been drafted for the Examination Guidelines for noise monitoringFinal drafts for industry review scheduled mid 2015 5© 2015 Electric Power Research Institute, Inc. All rights reserved.General Discussion Items 6© 2015 Electric Power Research Institute, Inc. All rights reserved.

San OnofreLessons Learned 7© 2015 Electric Power Research Institute, Inc. All rights reserved.Investigation into the Onset of In Plane Fluid Elastic InstabilitySGMP funding has been approved for 2015 2017 to investigate the onset of in plane fluid elastic instabilityA series of tests have been proposed by Canadian Nuclear LabsAir Flow testsDevelop a basic understanding of in plane vibration Two-Phase Freon TestsUse three support configurations and the most relevant two-phase flow conditions, demonstrate in

-plane fluid elastic instability 8© 2015 Electric Power Research Institute, Inc. All rights reserved.Phase 1 Test Setup -2015Meeting among industry experts to determine tube bundle and/or support configuration(s) and flow conditionsComplete test section assembly and calibration 9© 2015 Electric Power Research Institute, Inc. All rights reserved.Phase 2 Air Flow Tests 2015-2016Observe in plane vibration and fluid elastic instability behavior in air flow to make preparations for testing in two

-phase Freon flowExamine a variety of support configurationsTests will be representative of very high void fractions where the supports could be made wet or dryApproximately 24 configurations could be testedDifferent number of U

-bend support locationsDifferent tube

-support designsWet and dry supportsCentered and preloaded supportsA specific test matrix will be developed after the first industry expert meeting 10© 2015 Electric Power Research Institute, Inc. All rights reserved.Phase 3 Two

-Phase Freon Tests 2016-2017Convert the test rig for use with FreonDevelop test plans and proceduresTest at least three support configurations in a two

-phase flow condition most relevant to the industryMeasure tube damping with flowMeasure vibration at 0 to 98% void fraction up to and slightly beyond critical flows 11© 2015 Electric Power Research Institute, Inc. All rights reserved.Application of Test Resultsconstant, more effective supports, etc.)Goal is to understand what leads to the onset of in

-plane fluid elastic instabilityUtilities may be able to use results to avoid operating in these regimesSG designers may be able to understand their margins in operating SGs and avoid it with new designsThis is a learning effort that will be adjusted or stopped as each phase is completed, depending on the resultsfrom the results of this research 12© 2015 Electric Power Research Institute, Inc. All rights reserved.Tubesheet Joint Design 13© 2015 Electric Power Research Institute, Inc. All rights reserved.Tubesheet Joint DesignThe NRC learned that the tube

-to-tubesheet joint at one plant with replacement steam generators (alloy 690 tubing) was designed as the pressure boundary instead of the tube

-to-tubesheet weld.NRC requested the SGMP to determine if other steam generators have this designBased on an SGMP survey provided to the NRC in December 2014, there are 5 other domestic units identified designed and fabricated by the same vendor The tube-to-tubesheetwelds were designed to meet ASME Section III requirements 14© 2015 Electric Power Research Institute, Inc. All rights reserved.ASME Code Section III Requirements for Tube

-to-TubesheetWelds Credited as Pressure BoundaryIn addition, for those plants that consider the tube

-to-tubesheetweld as the pressure boundary, a difference exists in the practices of the vendors regarding whether or not the welds are analyzed in accordance with NB

-3000If the tube

-to-tubesheet weld satisfies the requirements currently specified in NB

-4350, all the ASME design requirements for tube

-to-tubesheet welds in a Class 1 component have been satisfiedAn inquiry was sent to Section III Code Committee for the January 28thinquiry meetingChair of the Interpretations committee will circulate the question to the entire BPV III standards committee on a letter ballotSome committee members stated that it was never intended to require full stress analysis of a tube to tubesheet weld and that NB

-4350 was intended as a design rule A working group has been given the responsibility to resolve the issueThe results of the inquiry may be a Code revision 15© 2015 Electric Power Research Institute, Inc. All rights reserved.SG Requirements in ASME Section XI 16© 2015 Electric Power Research Institute, Inc. All rights reserved.Steam Generator Requirements in ASME CodeNRC Observations from recent meetingsSection XI has rules that go beyond what is covered by the plant Technical Specifications If ASME deletes all the SG requirements from the ASME Code, the NRC will assess whether 10 CFR 50.55a should be modified to incorporate similar requirements NRC preference is to use consensus codes and standards; however, if there are no consensus codes and standards, the NRC may develop its own requirements NRC encouraged the SG industry to evaluate the situation, engage the ASME Code, and discuss in a future meeting 17© 2015 Electric Power Research Institute, Inc. All rights reserved.Steam Generator Requirements in ASME CodeASME Code action to delete steam generator requirements from Section XI did not pass4 negative votes out of 43Working on putting the preservicerequirements in Section IIIChanges to personnel qualification Section XI, IWA

-2300 passed Working Group Personnel Qualification, Surface, Visual, Eddy Current and Subgroup NDE at the January Code meetingAll other requirements should be deletedThe next opportunity to make change is the 2017 Code 18© 2015 Electric Power Research Institute, Inc. All rights reserved.Auto Analysis Workshop 19© 2015 Electric Power Research Institute, Inc. All rights reserved.Steam Generator Auto Data Analysis WorkshopAt the August 2014 NRC meeting with the SGTF, the NRC requested that the industry hold a workshop on SG automated data analysisThe purpose of the meeting would be to : response to previous NRC feedback on auto data analysisDiscuss Industry guidance Provide info on current auto data analysis systemsDiscuss auto analysis operating experienceProvide an opportunity to ask questions of industry auto data analysis expertsThe previous EPRI Auto Analysis Workshop was in Feb 2011The 54 registrants included: NRC (12), Utilities (14), NDE Vendors (20), Researchers (2) and EPRI (6) 20© 2015 Electric Power Research Institute, Inc. All rights reserved.Steam Generator Auto Data Analysis Workshop2015 Auto Data Analysis Workshop Location:EPRI CharlotteSchedule:Follows Aug 19 (AM) NRC meeting with SGTFWorkshop Day 1

-Aug 19: 1:00 PM 5:30 PMWorkshop Day 2

-Aug 20: 8:00 AM 4:30 PMPlanned ParticipantsUtilitiesSG NDE VendorsNRCResearch organizations 21© 2015 Electric Power Research Institute, Inc. All rights reserved.Steam Generator Auto Data Analysis WorkshopProposed 2015 Auto Data Analysis Workshop FormatSession 1

-Industry PerspectiveSession 2

-TechnologySession 3

-Operating ExperienceSession 4

-Panel DiscussionSession 5

-Technology Demonstrations 22© 2015 Electric Power Research Institute, Inc. All rights reserved.Thermal Heat Treatment of Tubing 23© 2015 Electric Power Research Institute, Inc. All rights reserved.Thermal Heat Treatment of Tubing MaterialNRC QuestionGuidelines have a temperature range specified with uncertainty bands (716 degrees C,

-0, +22)Does this range consider measurement uncertainty?Should guidelines be revised to be clearer?Measurement uncertainty is not explicitly addressed within the specification requirements or their technical basis in SGMP Technical Report 3002003124 Section 3.3.6.2 describes the technical basis for the thermal treatment temperature 24© 2015 Electric Power Research Institute, Inc. All rights reserved.Thermal Heat Treatment of Tubing MaterialThermal treatment requirements were developed for Alloy 600 to: Enhance carbide decoration of grain boundaries for SCC resistanceAllow Cr to diffuse back to grain boundaries (reduces possible -depletion at grain boundaries)Reduce residual stress from straightening and surface grinding.None of these objectives are strongly influenced by temperature variations in the range of 716

°C to 738°C. Thermocouple instrument error is insignificant relative to temperatures for carbide precipitation and stress relief. In the 1999 revision of the specification, the thermal treatment time was increased to add additional conservatism 25© 2015 Electric Power Research Institute, Inc. All rights reserved.Thermal Heat Treatment of Tubing MaterialMost significant source of uncertainty is the temperature variation within the furnace: Tubing is produced in accordance with ASME III NB

-2000, which requires calibrated and temperature

-surveyed furnacesHottest and coldest temperatures in the furnace are recorded to ensure compliance.Specification ensures that thermal treatment objectives are met through metallurgical analysis and stress measurements. Specification guidance is sufficient and does not require revision 26© 2015 Electric Power Research Institute, Inc. All rights reserved.Action Levels for Leakage 27© 2015 Electric Power Research Institute, Inc. All rights reserved.

Primary-to-Secondary Leakage LimitsNRC QuestionAction Levels are based on 150 gallon per day limitIs there any guidance to utilities if leakage limit in Technical Specification is less than 150 gallons per day?Guidelines require station procedures to contain limits and actions as required by Technical SpecificationsGuidelines note that, in most facilities, the alarm set points are determined by the plant Technical Specifications (actions to adjust set point ensure that the new set point is within Tech Spec limits) 28© 2015 Electric Power Research Institute, Inc. All rights reserved.Status of Adopting TSTF

-510 29© 2015 Electric Power Research Institute, Inc. All rights reserved.Status of Adopting TSTF

-510Majority of the US Utilities will have TSTF

-510 submittals to the staff by the end of 2015Three units (3 plants) economic evaluation does not support submittals at this time 30© 2015 Electric Power Research Institute, Inc. All rights reserved.Consistent Measuring of Flaw Amplitude 31© 2015 Electric Power Research Institute, Inc. All rights reserved.Feb 2013 SGTF Meeting with NRCThe NRC staff inquired about the industry guidance on evaluating signal amplitude, and phase during eddy current testing when substantial noise is present

.The NRC also asked if there was industry guidance to ensure a method for consistently quantifying flaw signal amplitude changes and phase changes in the presence of tube noise.

32© 2015 Electric Power Research Institute, Inc. All rights reserved.Example of Amplitude Comparison 33© 2015 Electric Power Research Institute, Inc. All rights reserved.Example of Amplitude Comparison 34© 2015 Electric Power Research Institute, Inc. All rights reserved.EPRI SG Examination GuidelinesPresent Guidance Revision 7When historical reviews are performed to determine if supplemental testing is warranted, the licensee shall define what constitutes change in terms of voltage and/or phase angle from the Lissajoussignal in the current inspection as compared to the same Lissajoussignal in the first ISI or the first ISI recorded on optical disk. When cracking mechanisms are present, the process of historical review is reviewing the actual raw or processed eddy current data; review of database report entries is not acceptable. When cracking mechanisms are not present, a review of the database report entries is acceptable.Revision 8 committee is considering additional guidance 35© 2015 Electric Power Research Institute, Inc. All rights reserved.Basis for Section D3.1 of In Situ Pressure Test Guidelines 36© 2015 Electric Power Research Institute, Inc. All rights reserved.Basis for Section D3.1 of In Situ Pressure Test GuidelinesNote in Section D3.1 of In Situ Pressure Test Guidelines: Degradation at lattice type eggcratesupports is not exempt from in situ proof testing, as it has been shown that these supports provide little strengthening to regions with axial degradation. The same is true of broached TSP supports

.axial flaws within eggcratesupports, not documented in the guidelinesTests have recently been performed to provide basis for trefoil and quatrefoil supports and will continue to address eggcrates 37© 2015 Electric Power Research Institute, Inc. All rights reserved.Results of Recent Testing 38© 2015 Electric Power Research Institute, Inc. All rights reserved.ConclusionsFor wear flaws that challenge 3dP structural integrity performance criterion, trefoil supports do not elevate the burst pressureSimilar results are expected for quatrefoil and eggcratesupports 39© 2015 Electric Power Research Institute, Inc. All rights reserved.

Anti-Vibration Bar Position Verification 40© 2015 Electric Power Research Institute, Inc. All rights reserved.Anti-Vibration Bar MispositioningWhite paper developed incorporating information from 2012 meeting among SG vendors regarding AVB position verificationAvailable to utilities on EPRI websiteRecommendations have been provided to the Integrity Assessment Guidelines CommitteeWestinghouse published NSAL 12

-Vibration Bars in Alloy 600TT Steam Generators with Quatrefoil Tube Support PlatesConcluded that it is judged that the worst case consequence of this issue does not result in a Substantial Safety HazardSGMP Project began project in 2012 to provide generic input for plant

-specific U

-bend tube fatigue analysisFollow up survey in 2012 indicates the utilities are familiar with the issue and are taking actions as appropriate 41© 2015 Electric Power Research Institute, Inc. All rights reserved.Anti-Vibration Bar MispositioningThe issue is considered applicable only to those steam generator manufactured before 1985AVB design has reduced or eliminated gaps as much as possible by controlling AVB and tube tolerances.Manufacturing process control has been improved to document the as

-built condition vs. the as

-designed condition. AVB depth of insertion and alignment are recorded in manufacturing records.Significant depths of insertion variations are not expected; hence, the potential for flow peaking factors is minimal.

42© 2015 Electric Power Research Institute, Inc. All rights reserved.SGMP U-Bend Fatigue ProjectSGMP began a project in 2012 to perform the generic work that would provide necessary inputs into plant

-specific analysesATHOS analysis provides input to flow induced vibration analysis for open and occluded TSP conditionsMean stress and unit bending moment calculations for Fixed, Pinned and Open Gap tube constraintsReview of flow peaking factor data from the NRC Bulletin 88

-02 analyses to determine a correction factors for application to affected models of SG (F, D5, 44F, 51F)FIV analysis for rows of interest (F: 5

-12) for Fixed, Pinned and Open Gap tube constraints and case

-specific damping 43© 2015 Electric Power Research Institute, Inc. All rights reserved.SGMP U-Bend Fatigue ProjectModel F work completed in 2013 (Report No. 3002001991)Model D5 technical work was completed in 2014Technical report will be published in 2015Model 44F and 51F work will begin in 2015Technical report will be published in 2016Plants with susceptible SGs are investigating the insertion depths of AVBsThey need to generic work to be completed prior to the site specific analysis 44© 2015 Electric Power Research Institute, Inc. All rights reserved.Standing Discussion Topics 45© 2015 Electric Power Research Institute, Inc. All rights reserved.Recently Issued SGMP Technical ReportsSteam Generator Management Program: Investigation of Crack Initiation and Propagation in the Steam Generator Channel Head AssemblySGMP Technical Report 3002002850 (October 2014

)Steam Generator Management Program: Lead Stress Corrosion Cracking of Nuclear Grade Alloy 800SGMP Technical Report 3002002853 (Nov 2014) 46© 2015 Electric Power Research Institute, Inc. All rights reserved.SGMP Industry Document Status and Revision ScheduleGuideline TitleCurrent Rev #Report #Last Pub DateImple-mentation Date(s)Interim GuidanceReview DateCommentsSG Integrity Assessment Guidelines 31019038Nov 20099/1/10SGMP-IG-10-01SGMP-IG-12-01TBDRev 4 in progressEPRI SG In Situ Pressure Test Guidelines 41025132Oct201210/10/13NoneTBDRev 5 will begin in 2015PWR SG Examination Guidelines 71013706Oct 20079/1/08SGMP-IG-08-04SGMP-IG-12-01SGMP-IG-14-02TBDRev 8 in progressPWR SG Primary

-to-Secondary Leakage Guidelines 41022832Sept. 20114/11/2012 7/11/2012None2015 47© 2015 Electric Power Research Institute, Inc. All rights reserved.SGMP Industry Document Status and Revision ScheduleGuideline TitleCurrent Rev #Report #Last Pub DateImple-mentationDate(s)Interim GuidanceReview DateCommentsPWR Primary Water Chemistry Guidelines 73002000505 April 20141/28/2015None2017PWR Secondary Water Chemistry Guidelines 71016555Feb 20098/20/09 11/20/09SGMP-IG-13-01SGMP-IG-14-01TBDRev 8 process planned to begin in 2015Steam Generator Management Program Administrative Procedures 31022343Dec 20109/1/11 12/31/11NoneN/ARev 4 in progressSteam Generator Degradation Specific Flaw Handbook 11019037Dec 2009N/ANone N/ARev 2 in progress 48© 2015 Electric Power Research Institute, Inc. All rights reserved.Interim Guidance SGMP

-IG-14-02 Examination Guidelines, R7Prescriptive guidance not consistent with current performance

-based requirements in Technical Specifications were removed from Section 3 of the Examination Guidelinesfor each degradation mechanism within the confines of Technical Specification intervalsExample: A plant may be required to inspect 100% of the top of the tubesheet for cracking, but not 100% of the tubing for wear 49© 2015 Electric Power Research Institute, Inc. All rights reserved.Interim Guidance SGMP

-IG-14-02 Examination Guidelines, R7Sampling shall be performed such that all tubing is examined within the periods established by Plant Technical Specifications and the Degradation Assessment. Wording removed:Tube selection within a sample plan shall be governed by the following requirements: 1. The tubes are selected on a random or systematic basis, and evenly distributed across the tube bundle to the extent practical (e.g. As Low As Reasonably Achievable (ALARA) considerations). 2. All inservicetubes that have prior indications of degradation and/or historical possible loose parts (PLP) are examined through the area of interest when the applicable SGs are open for examination. 3. Peripheral tubes, including tubes adjacent to no

-tube lane regions, are included or added to a sample plan or considered a separate sample plan when there is reason to expect that loose parts are present or were introduced into the SG secondary side. A secondary

-side foreign object search and retrieval (FOSAR) examination may be used to meet this requirement.

50© 2015 Electric Power Research Institute, Inc. All rights reserved.Interim Guidance SGMP

-IG-14-02 Examination Guidelines, R7Section 3.6 contains a reference to the Steam Generator Integrity Assessment Guidelines for determining steam generator examination scopeSection 6 of the Integrity Assessment Guidelines requires utilities to develop a Degradation Assessment which includes an inspection scope for all existing and potential degradation mechanisms 51© 2015 Electric Power Research Institute, Inc. All rights reserved.NEI 03-08 DeviationsThreelong-term deviations Two Steam Generator Examination Guidelines, R7Single party auto analysisSteam Generator Integrity Assessment Guidelines, R3Use of site

-specific sizing indicesOne short term deviationsSteam Generator Examination Guidelines, R7PSI prior to hydro 52© 2015 Electric Power Research Institute, Inc. All rights reserved.Operating Experience 53© 2015 Electric Power Research Institute, Inc. All rights reserved.Recent Operating Experience Reported at December SGMP Technical Advisory Group MeetingSpring 2014 outage inspections identified foreign objects generators.These foreign objects were determined to be part of the support system for the feedrings

.Additional inspections identified that the feedringsupports had been damaged due to a steam void in the feedringsystem.The damaged supports were repaired during the outage.The function of the feedringwas not impacted.

54© 2015 Electric Power Research Institute, Inc. All rights reserved.

Recent Operating Experience Reported at December SGMP Technical Advisory Group MeetingThe cause evaluation included a review of the guidance provided in NUREG-0291 and NUREG

-0927Potential causes for the steam void:Feedringleakage through inspection port bolted to ends of feedringBack leakage through the feedwater systemAn important mitigating action is to limit the feed rate while the feedringis uncovered; industry accepted limit is 150 gpmFollow-up inspections will be implemented to verify effectiveness of actions taken This experience was reported at TAG meeting June 2014 55© 2015 Electric Power Research Institute, Inc. All rights reserved.NRC Discussions/Items of Interest 56© 2015 Electric Power Research Institute, Inc. All rights reserved.Acronyms 57© 2015 Electric Power Research Institute, Inc. All rights reserved.AcronymsASME American Society of Mechanical EngineersEPRI Electric Power Research InstituteAVB Anti Vibration BarIG Interim GuidanceN/A Not ApplicableNEI Nuclear Energy InstituteNRC Nuclear Regulatory CommissionPSI Preservice InspectionPWR Pressurized Water ReactorSG Steam Generator 58© 2015 Electric Power Research Institute, Inc. All rights reserved.AcronymsSGMP Steam Generator Management ProgramSGTF Steam Generator Task ForceTBD To Be DeterminedTSP Tube Support PlateTT Thermally TreatedUS United States

© 2015 Electric Power Research Institute, Inc. All rights reserved.Future of Electricity

Retrieved from "https://kanterella.com/w/index.php?title=ML15160A414&oldid=777522"