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Check Valve Condition Monitoring Workshop

Check Valve Condition Monitoring Workshop. ISTOG/NIC Summer Meeting 2005. WORKSHOP TEAM MEMBERS Debbie Masters, FP&L – Team Lead Shawn Comstock, WCNOC Les Harris, SCE&G Steve Hart, Duke Power Brian Lindenlaub, APS Tony Maanavi, EXELON Mike Robinson, K&M Consulting

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Check Valve Condition Monitoring Workshop

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  1. Check Valve Condition Monitoring Workshop ISTOG/NIC Summer Meeting 2005 WORKSHOP TEAM MEMBERS Debbie Masters, FP&L – Team Lead Shawn Comstock, WCNOC Les Harris, SCE&G Steve Hart, Duke Power Brian Lindenlaub, APS Tony Maanavi, EXELON Mike Robinson, K&M Consulting Vinod Sharma, Kalsi Engineering

  2. Workshop Rules • Professional Etiquette • Only one speaker at a time • Hold major questions for panel discussion – pl. use index card • Stay on time - time keeper will be used

  3. Workshop Format • Code broken down into sections • Review the applicable sections of the code - these slides will be in ‘Italics’ • In simple terms, explain what it means - our interpretation • Examples - from different plants using CM • Implementation tips • Discussions

  4. AGENDA 8:00 – 8:25 Appendix II.1 Introduction - DM 8:25 – 8:50 Appendix II.2 Groupings - VS BREAK 9:00 – 9:25 Appendix II.3 Analysis - LH 9:25 – 9:50 Appendix II.4 Condition Monitoring Activities - DM BREAK 10:00 – 10:25 Appendix II.5 & II.6 Implementation - MR 10:25 – 10:50 CM Best Practices - VS BREAK 11:00 – 11:30 Panel Discussion

  5. INTRODUCTION Presented by: Debbie Masters

  6. What is CM? • Alternative to prescriptive testing of IST valves • Living Program • Continuous/periodic measurement of characteristics using the proper mix of activities to validate the condition of a check valve • A trending process and evaluation process that’s part of a living check valve program in which predictions are confirmed and adjusted - review after each outage/test to validate the plan • Test strategy is to identify and trend attributes indicative of degradation that could lead to failure

  7. CM Evolution... • ASME/NRC agree on the need for improved rules for check valve • Testing not detecting all degradation • Need for trending • testing and need for disassembly • Initial OM22 meeting • Standard vs. Code • Piece meal changes to Code - Shawn’s paper • NIC proactively works to change testing requirements • NRC requests - NIC work with OM22 for better/improved testing related guidance and requirements • NRC to ASME - need to revise the requirements to ensure the adequacy of certain pump and valves to perform their intended safety function • NUREG 1352 - NRC expressed concern about MOV’s & CV’s • Generic Letter 89-04 (NUREG-1482)

  8. ...CM Evolution • NRC Activities • NUREG’s 1482 and 5944 • Studies ORNL/NRC/LTR-96/11 and -96/13 • Symposiums • Change 10CFR50.55A to include Condition Monitoring • Approval (Sept 1999) of Rule Change which included Appendix II of the ASME OM Code with limits (discussed later) • Approval (Nov 2004) of Rule Change which includes step wise interval extensions with outage time based maximum intervals.

  9. Workshop Objectives • Review the code requirements to establish a Condition Monitoring Program • Present actual information and data from utilities on how to establish a program • Address issues related to Condition Monitoring • Use as basis to develop “CM for Dummies”

  10. Appendix II.1 Purpose • To establish and maintain a Check Valve Condition Monitoring Program in accordance with ISTC - 5222

  11. What valves can go into CM? • IST (Inservice Test) Program Valves only • Concept of CM Program may be applied to non-IST valves - may or may not be in the same program • Begin with the ones that provide the mostbang for the buck All Check Valves IST CM

  12. Traditional IST vs. CM • TRADITIONAL IST • Check valve tested as a part of a system – all check valves are treated and tested as if they are the same • Prescriptive test program is set at the beginning of each code update(change requires a relief request) • Test is a snapshot of valve’s ability to function in the safety direction – at the time of the test • CONDITION MONITORING • Check valve treated as a component with unique, design, application & failure mechanisms • Flexible program allows adopting most suitable test methods and technologies as they become available or continuing existing maintenance and test practices • Use of methods (disassembly, NIT, etc) that are already being used • Test strategy concentrates on likely failure mechanisms and therefore addresses present and future reliability

  13. Why go to CM? TECHNICALLY: Value adding test activities - concentrate on developing useful intelligence on unique valve(/group) specific failure mechanisms ECONOMICS: Living program cuts costs through savings in - valve maintenance/testing crew man-hours for scaffolding, insulation, temporary instrumentation, RP/OPS/MM/Engineering/RT • ALARA mRem exposure avoided, • Reduced disassemblies – with reduction in maintenance induced failures, • aligning CM program with other programs e.g. by taking credit for Option B for leak testing, Appendix J LLRT program, PIV Additional cost savings through • Enables setting test frequency based on plant history • Step wise interval extension • Enables adopting latest and most suitable test methods & technologies • Added flexibility - Scheduling tests and disassemblies off the critical path, bidirectional test not required in the same interval – on-line disassemblies, LCOs

  14. Why not go to CM? TECHNICALLY: Not yet at 10-yr update - Will eventually have to go to bidirectional testing; ECONOMICS: • implementation costs • Testing in safety direction only • If already gone to update and it is too late to implement CM immediately

  15. Invoking Condition Monitoring • 10-yr Code Update OR • Letter to NRC – should include the following: • What valves are going into the program • Application of the latest code to all of the IST valves • Implementation time frame - rule of thumb - two years • Using a letter, utility must wait for NRC approval before implementing later editions of the code. Clarified in NRC Regulatory Issue Summary 2004-12 <PROVIDE SAMPLE>

  16. Definitions • Cherry Picking - If you have not had a code update, cherry picking is choosing to apply Appendix II to some of the your valves without bi-directionally testing all of them. Any application of Appendix II will require testing all IST check valves to the latest code (bi-directional testing). • Bi-directional Testing - Valve opening and closing functions must be demonstrated when flow testing or examination methods (non-intrusive or disassembly) are used. Flow testing does not need to be at full flow.

  17. Terms Used in Workshop • CM - Condition Monitoring Program • PM - Preventative Maintenance • CM-PI - Condition Monitoring Program - Performance Improvement • CM-O - Condition Monitoring Program - Optimization

  18. GROUPING Presented by: Vinod Sharma

  19. Appendix II.2 Grouping Determined by Owner Shall be technically justified based on: • Intended Purpose: CM-PI or CM-O • Assessment/performance analysis (Plant Specific) • Test results • Maintenance History • Justification: • Design Characteristics: Types, sizes • Application/safety function • Services Conditions: frequency of usage

  20. Interpretation… • Why are the valves being added to the Condition Monitoring Program? Performance Improvement or Optimization • Background knowledge • Available plant specific tests • Why are the valves being grouped together? • Design Characteristics – Type & Model – incl. suffixs • Bonnet: Bolted, pressure seal, seal welded, screwed, • Seat: soft, hard • Hangar Arm: Bonnet Hung • Materials: Body, seat • Flange design • Size • Application/safety function • Services Conditions : Fluid, duty, flow, pressure, temperature

  21. …Interpretation • Justification factors to consider: • Manufacturing data • Manufacturer • Valve type • Size • Model Number • Vendor Drawing • Vendor Manual

  22. Example - Plant A - Grouping Evaluation

  23. Example - Plant A - Design Characteristics

  24. Example - Plant B - Design Characteristics

  25. Tips - Grouping • Look at the IST population not as 100 valves but 30 groups. Much easier to manage • No benefit of very large groups – e.g. Hard to correlate performance data for stepwise interval extension (4 valves/ group optimal e.g. 8 as in 2 groups of 4 clumped together –cannot extend interval) • Typical type groupings - same valve on different trains, accumulator dump valves, favored trains (but watch for exceptions - two pumps with elbow oriented differently) • Difference between CM-O and CM-I • Groups across units vs. keep separate: + interval extension for all – Do common cause for all

  26. Application Experience/Quick Clarification – 5 Minutes • Any utility experiences with groupings

  27. ANALYSIS Presented by: Les Harris

  28. Appendix II.3 Analysis Analyze test & history of valve or group to establish a basis for specifying in-service testing, examination, and preventive maintenance; shall: • Identify common failure or maintenance patterns • Analyze patterns to determine significance and identify potential failure mechanisms to determine (plant specific and industry) • If certain PM will mitigate failure or maintenance patterns • Feasibility & effectiveness of CM activities like NIT in monitoring for valve/group specific failure mechanisms • Effectiveness of periodic disassembly & examination in in monitoring for valve/group specific failure mechanisms • Need for changes in the valve grouping

  29. Interpretation... • For each group (looking at history): • analyze all of the maintenance history • analyze all of the test history • Need to review industry information • Determine if there is any common failure or maintenance history patterns • Evaluate potential effects

  30. ...Interpretation... • If there is no common failure or maintenance pattern, then group can go into CM activity – optimization of good actors • If there is a common failure or maintenance pattern, then the group needs to be analyzed for the significance and potential failure mechanisms. • Determine: • If certain PM will mitigate failure or maintenance patterns • Feasibility & effectiveness of CM activities like NIT in monitoring for valve/group specific failure mechanisms • Effectiveness of periodic disassembly & examination in monitoring for valve/group specific failure mechanisms • Need for changes in the valve grouping

  31. ...Interpretation… • If there is sufficient information to perform the analysis, then the group may be placed in the CM - optimization • If there is not sufficient information to perform the analysis or if the analysis is not conclusive, then the group shall be placed in the CM - performance improvement activities (3 years or 2 cycles which ever is greater)

  32. ...Interpretation – Where to get information • NRC – Generic Notices, Information Notices • NIC templates and failure database • LER/OE notices • EPIX database review • EPRI PM Templates • Vendor Notifications • Utility/Plant Records • IOM Review • Post 1984 – NIC database 95% completed

  33. Examples – Failure Modes • Failure to Open • Failure to Close • Internal Leakage • External Leakage • Disk Separation • Hinge Pin Wear EG: PWR full dump of SI tank if failure to open is not a plausible failure then can Go to partial stroke NIT test to avoid flow testing; also can use PIV tests.

  34. Examples – Failure Causes • Abnormal Wear – flow velocity < Vmin or seat leakage • Design • Human Error • Maintenance Error • Manufacturing Defect • Corrosion • Foreign Material • Procedure Error • Improper Installation • Stress Corrosion Cracking • Erosion/Corrosion • Improper Installation • Other

  35. Examples - Test & Inspection Effectiveness to Detect Failure/Degradation • Full Open Stroke w/flow • Partial Open Stroke w/flow • Back Flow Test • Manual Exercise • Leak Test/LLRT • Disassembly & Inspection • PIV • Other • Temperature Monitoring • Thermography • Radiography • Ultrasonic Testing • Magnetics • Acoustics • Routine Operator Rounds • System Monitoring

  36. Example - Analysis - Plant A

  37. Example - Analysis - Plant B

  38. Example - Analysis - Plant C

  39. Example - Analysis(continued) - Plant C

  40. Tips - Analysis • Service Experience: NRC – NIC database (www.checkvalve.org), GNs & INs, LER/OE notices, EPIX, Vendor Notifications • Get best information possible

  41. Application Experience/Quick Clarification – 5 Minutes • Utility experiences with analysis

  42. CONDITION MONITORING ACTIVITIESPerformance Improvement and Optimization Presented by: Debbie Masters

  43. Appendix II.4a Condition Monitoring Activities - Performance Improvement... IF lacking sufficient information for II.3 Analysis or if results are inconclusive then perform the following to determine cause of the failure or maintenance patterns, THEN identify • interim tests to assess performance • interim examination to evaluate potential degradation mechanisms • Other types of analyses to assess valve condition • Set of above performance improvement (CM-PI) activities for each valve in the group and interval for activity; Document PI activities in CM Program test plan

  44. …Appendix II.4a Performance Improvement Perform PI activities until, • Sufficient information to assess performance adequacy • End of 5 years or two fueling outages Review results of each PI to determine need for changes; if changes significant repeat Sections of II.2, II.3 & II.4 asapplicable

  45. Interpretation - Performance Improvement • If determined to be in Performance Improvement then: • Develop an interim strategy to gather data for the 2 refueling or 5 years (which ever is less) • Strategy should identify: • interim test to assess performance • interim examination to evaluate degradation • other types of analysis to assess condition • the interval of each activity • Need to gather sufficient information to perform analysis • If enough information is gathered, then CM-optimization

  46. Tips - Performance Improvement • Performance improvement plan is done until enough information is gathered to perform the analysis and determine if there are any common mode failures or maintenance patterns

  47. Appendix II.4b Condition Monitoring Activities - Optimization... If sufficient information for II.3 Analysis to assess performance adequacy, then identify • Applicable PM activities & intervals to maintain continued acceptable valve performance • Applicable examination activities & intervals to periodically assess the condition • Applicable test activities & intervals to periodically verify acceptable performance • Set of above CM-O activities to be performed on each valve in the group and interval for activity Revise CM Program test plan to document CM-O activities

  48. …Appendix II.4b Condition Monitoring Activities - Optimization Perform CM-O activities Review results of CM-O activities to determine need for changes; if changes significant repeat Sections of II.2, II.3 & II.4 as applicable

  49. Interpretation- CM Optimization... • If the group has been determined to be in CM-optimization then the following activities need to be considered: • preventative maintenance activities required to maintain performance • examination activities to assess condition • test activities to verify acceptable performance

  50. ...Interpretation - CM Optimization • The activity plan identifies: • which activities will be performed on each valve in group and • the interval for each activity • There are NRC limitationson these - will be discussed next

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