Check Valve Condition Monitoring Workshop

ISTOG/NIC Summer Meeting 2005

WORKSHOP TEAM MEMBERS

Debbie Masters, FP&L – Team LeadShawn Comstock, WCNOC Les Harris, SCE&GSteve Hart, Duke Power Brian Lindenlaub, APS Tony Maanavi, EXELON Mike Robinson, K&M ConsultingVinod Sharma, Kalsi Engineering

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

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

AGENDA8:00 – 8:25 Appendix II.1 Introduction - DM8:25 – 8:50 Appendix II.2 Groupings - VS

BREAK9:00 – 9:25 Appendix II.3 Analysis - LH9:25 – 9:50 Appendix II.4 Condition Monitoring Activities -

DMBREAK

10:00 – 10:25 Appendix II.5 & II.6 Implementation - MR10:25 – 10:50 CM Best Practices - VS

BREAK11:00 – 11:30 Panel Discussion

INTRODUCTION

Presented by: Debbie Masters

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

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)

...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.

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”

Appendix II.1 Purpose

• To establish and maintain a Check Valve Condition Monitoring Program in accordance with ISTC - 5222

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 most bang for

the buckAll Check Valves

IST

CM

Traditional IST vs. CM

TRADITIONAL IST

1. Check valve tested as a part of a system – all check valves are treated and tested as if they are the same

2. Prescriptive test program is set at the beginning of each code update (change requires a relief request)

3. Test is a snapshot of valve’s ability to function in the safety direction – at the time of the test

CONDITION MONITORING

1. Check valve treated as a component with unique, design, application & failure mechanisms

2. Flexible program allows adopting most suitable test methods and technologies as they become available or continuing existing maintenance and test practices

3. Use of methods (disassembly, NIT, etc) that are already being used

4. Test strategy concentrates on likely failure mechanisms and therefore addresses present and future reliability

Why go to CM?TECHNICALLY: Value adding test activities - concentrate on developing

useful intelligence on unique valve(/group) specific failure mechanismsECONOMICS: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, PIVAdditional 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

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

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>

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.

Terms Used in Workshop

• CM - Condition Monitoring Program

• PM - Preventative Maintenance

• CM-PI - Condition Monitoring Program - Performance Improvement

• CM-O - Condition Monitoring Program - Optimization

GROUPING

Presented by: Vinod Sharma

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

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

…Interpretation

•Justification factors to consider:–Manufacturing data

–Manufacturer–Valve type–Size–Model Number–Vendor Drawing–Vendor Manual

Example - Plant A - Grouping Evaluation

Example - Plant A - Design Characteristics

Example - Plant B - Design Characteristics

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

Application Experience/Quick Clarification – 5 Minutes

• Any utility experiences with groupings

ANALYSIS

Presented by: Les Harris

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

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

...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

...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)

...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

Examples – Failure Modes

• Failure to Open

• Failure to Close

• Internal Leakage

• External Leakage

• Disk Separation

• Hinge Pin WearEG: PWR full dump of SI tank if failure to open is not a plausible failure then canGo to partial stroke NIT test to avoid flow testing; also can use PIV tests.

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

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

Example - Analysis - Plant A

Example - Analysis - Plant B

Example - Analysis - Plant C

Example - Analysis(continued) - Plant C

Tips - Analysis

• Service Experience: NRC – NIC database (www.checkvalve.org), GNs & INs, LER/OE notices, EPIX, Vendor Notifications

• Get best information possible

Application Experience/Quick Clarification – 5 Minutes

• Utility experiences with analysis

CONDITION MONITORING ACTIVITIES

Performance Improvement and Optimization

Presented by: Debbie Masters

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

…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 as applicable

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

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

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

…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

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

...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 limitations on these - will be discussed next

NRC Limitations1.There are no limitations if evoking the code as accepted in the

NRC Rulemaking dated Nov. 2004.

2. If invoking the NRC Rulemaking dated 1998, the NRC required following:

– Valve opening and closing functions must be demonstrated - bi-directional testing

– Initial interval for tests/associated examinations may not exceed 2 fuel cycles or 3 yrs, whichever is longer; any extension of this interval may not exceed 10 yrs (unless adopted 2003 in which case is 10, 12 or 16 years? depending on group size of 1, 2-3, or >=4, respectively)

– If Appendix II Condition Monitoring Program is discontinued, then requirements of ISTC 4.5.1 through 4.5.4 must be implemented.

Example - Condition Monitoring Activities - Plant A

Example - Condition Monitoring Activity - Plant B

Example - Condition Monitoring Activity (continued) - Plant B

Example - Condition Monitoring Activity (continued) - Plant B

Example - Condition Monitoring Activity - Plant C

Example - Condition Monitoring Activity (continued) - Plant C

Tips for Developing Condition Monitoring Activities

• Know what test are performed currently in the plant

• Need to think about the bi-directional test

• Take credit for testing whenever possible - pump starts, valve closure for opposite train pump starts

Application Experience/Quick Clarification – 5 Minutes

• Utility experience with Condition Monitoring Activities

IMPLEMENTATION

Presented by: Mike Robinson

Appendix II.5 Corrective Maintenance

IF

corrective maintenance is performed on valve

THEN

Review analysis used to formulate basis of CM activities for the valve and the group to determine the need for changes; if changes significant repeat Sections of II.2, II.3 & II.4 as applicable

Interpretation for Corrective Maintenance

• It is important to consider baseline data after the completion of corrective maintenance

• Need good baseline data for the application of any frequency extension

Appendix II.6 Documentation

Shall include:• List of valves in program• List of valves in each group• Dates and the reason that the valves were

added/deleted to the program • Analysis forming the basis for the program• Identified failure or maintenance history pattern

for each valve• Program activities & interval

Interpretation for Documentation

• New procedures for CM

• Adding/removing valves

• Extension of due dates/missed test?

• Test Start dates – simultaneously for all groups?

• Importance of feedback

Intervals - Frequency Extensions

• Ensure adequate baseline

• Two successful tests in a row on the group, then one interval extensions may be applied

• Should not exceed one extension at a time

• Do not exceed the code allowable limits

Stepwise Interval Extension Savings Traditional IST vs CM

Oc 0 1 2 3 4 5 6 7 8 9 10 11 12

A X X X X X X X X X X X X X

B X X X X X X X X X X X X X

C X X X X X X X X X X X X X

D X X X X X X X X X X X X X

Oc 0 1 2 3 4 5 6 7 8 9 10 11 12

A Xb X X

B Xb X X

C Xb X

D Xb X X

9< 10 yrs ---- --> X

52 prescriptive tests reduced to 12 targeted CM Program tests over 18 years

TRADITIONAL IST

CONDITION MONITORING

Stepwise Interval Extension Frequency Extensions….

Stepwise Interval Extension ...Frequency Extensions...

Stepwise Interval Extension ...Frequency Extensions

Self Assessments Some Things to Consider

• Defined program responsibilities• Verify testing methodology demonstrates the

required function of the valve• Maintenance and failure reviews have been

conducted and results documented• Valve performance and failures are being

documented and test plan re-evaluated

Example - Interval Extension/Implementation

Implementation Tips - Documentation, Interval Extension,

Self-Assessments • Responsibility for CM program can lie with the

CV engineer, IST Coordinator, or system engineer• Implementation can be done by in-house, vendor

or combination of each of these• Interval extensions may get confusing if train

related outage are employed

Resources Requirements – Time & Expense

Start-upGroupingsAnalysisCondition Monitoring – Performance Improvement

ActivitiesCondition Monitoring – Optimization ActivitiesDocumentation

Program procedure Data Storage

Application Experience/Quick Clarification – 5 Minutes

• Utility experiences with application, frequency extensions or implementation issues

CM Best Practices – Vinod Sharma

• Goal: No unexpected/unanticipated failures • Employ the use of an expert panel - optional• Keep the program living through periodic reviews e.g

grouping basis, power uprate, obsolesence• Aggregate information about the valve from many

different sources - NIT, pressure tests, flow tests, LLRT, etc + Ties in with other programs e.g.AP-913

• Tracking and Trending of trendable attributes- NIC Phase 4, NIC T&T Guide

• CVAP for quantitative analysis – forecasting vs. accounting

• Other examples?

Plants that have implemented CM

PWR• Seabrook• Surry• Millstone• VC Summer• Byron• Wolf Creek• McGuire • Palo Verde

BWR

• Vermont Yankee

• Pilgrim

12/8/04 Feedback

• Add to NIC database

– Frequently asked questions with answers

– References – white papers, presentations, latest OM code; letter (Using a letter, utility must wait for NRC approval before implementing later editions of the code.

Clarified in NRC Regulatory Issue Summary 2004-12 ) in 10CFR50.55

– Provide plant examples – Diablo Canyon

• Procedure change one lines– Reverse closure of parallel pumps; other pump not rotating backwards

• Introduction, Plant CM or not, Expectations