Maintanence Optimization Equipment Reliability Practices

Institute of Graduate Studies in Science and Engineering
Electrical and Electronics Engineering
Power Supply and Actuators in Electrical Railway Systems Lecture
Prof.Dr. Abdul Rahman Hussian
Maintanence Optimization: Equipment Reliability Practices
Harbin, China
May, 2017
Core Processes
•Data Management
•Functional Equipment Groups (FEG) to Support Automated Work Scheduling
•Criticality Determination
•Single Point Failure Vulnerability
•Critical Components and Critical Spares
•Performance Monitoring Plan (PMP) Development and Monitoring
•Maintenance Optimization (MO)
•Long Term Plan Development
•Corrective Action Program
•Maintenance Feedback
Maintenance optimization
•Objectives of NPP maintenance optimization
•Maintenance optimization requirements and
•Key elements of maintenance optimization
•Performance indicators
Criticality Determination
•Identify those components most critical to plant
safety and reliability
•Used to allocate resources
•Used to prioritize work
Critical component failures cause
•significant power transient or derate
•loss of a redundant safety function
•unplanned entry into a technical specification LCO
•half scram or partial trip
•reactor shutdown
•actuation of emergency safeguards features
Critical component failure cause
•failure to control a critical safety function such as reactor water level and
pressure, primary and secondary containment, drywell temperature and
pressure, or spent fuel pool temperature and level
•degraded capability to shut down the reactor and maintain it in a shutdown
•inability to perform an emergency operating procedure, or to prevent or
mitigate the consequences of accidents that could result in potential off-site
exposure in excess of 10CFR100 limits; operator workaround
•operator workaround for performing any of the above functions or procedures.
Criticality Analysis Results
61287 components reviewed
Crit 1 = 13331, or 22% (SR)
Crit 2 = 26462, or 43% (Important)
Crit N = 21494, or 35% (Run to failure)
22 Weeks
4400 Consultant Man-Hours
2100 Internal Man-Hours
Single Point Vulnerability Study
•A SPV exists if failure of a single component results in:
–Reactor Trip, or
–Turbine Trip, or
–Generator electrical power output reduction > 5%.
(Note: Initial condition 100% power)
Most Significant Components Affecting Unit
Reliability - As Derived from SPV Studies
•Air-operated valves
•Emergency diesel generator - electrical
•Main feedwater pump
•Main generator and support systems
(Not listed in order of importance)
Non-critical component
•Component failure creates an unacceptable increase in personnel, industrial,
environmental, or radiological safety hazard.
•The component has a history of unacceptably high repair, replacement, or
operational cost.
•Component failure represents an operator or maintenance burden.
•The component is obsolete, in short supply, or very expensive to repair or
•There is a long lead time for replacement parts, which prevents a required
component from being repaired in a timely fashion.
•The component is necessary for work on critical equipment (for example,
isolation valve).
Non-critical component
•Component failure promotes failure of other components.
•There is a potential for new risks from hazardous chemicals or
environmental concerns.
•Failure results in a power transient, sustained generation loss, or
reduction in the necessary redundancy or defense in-depth.
•Failure may lead to regulatory consequences.
•Component failure will hamper or prevent timely repair of a critical
•It is more cost-effective to maintain the component, as opposed to
repair or replacement.
Run to failure components
•A run-to-failure component is one for which the risks and
consequences of failure are acceptable without any predictive or
repetitive maintenance being performed and there is not a simple,
cost-effective method to extend the useful life of the component.
•The component should be run until corrective maintenance is
Performance Monitoring
Typical Equipment Reliability Program
Criticality Determination:
* Equipment Importance
* Basis
* Duty
* Environment
Functional Equipment Group
* Boundaries
* Equipment In Boundary
* Characteristic Information
Required Levels of
Performance :
* Reliability
(Functional Failures)
* Unavailability
* Cost
* Basis for Levels of
Operating Rounds:
Engineering :
* Walk-down Inspection
* Operational Performance
* Problem Resolution
* Trends in Performance
* System and Component
Health Reports
Pressure Instrument
* Operating Log - Discharge Pressure
within Band
* PM - calibration
(In a Calibration FEG) AA
* Plant Computer - Number of
Breaker Cycles
* Plant Computer - With Flow,
Calculate Run Time
* PM - Disassembly and Inspection
* PM - Overhaul
* PdM - Thermography
Flow Instrument
* Plant Computer - calculate run
time, ID degraded flow
* PM - calibration
Manual Valve
* Run to Failure
* PdM - Vibration Monitoring
* PdM - Oil Sample
* STP - Performance Test
* Operations - Periodic Rotation of
Redundant Equipment
Recirc Pressure
* Run to Failure
* Operate per Procedures
* Configure Plant for
Recorded Parameters : (PMP)
* Plant Operating Logs - in band
* Plant Operating Logs - trended
* Plant Computer - in band
* Plant Computer - trended
* PdM - Vibration Monitoring
* PdM - Oil Sample
* PdM - Motor Circuit Analysis
* PdM - Motor Current Analysis
* PdM - Motor Insulation
* PM - Sample Inspection of
Motor Population
Time or Condition Based
Repetitive Maintenance: (MO)
* Preventive Maintenance (PM)
* Predictive Maintenance (PdM)
* Planned Maintenance
* List Surveillance Test
Procedures (STPs)
* Basis for Repetitive
Motor Operated Valve
* PM - External Inspection
* PM - Stem Lubrication
* PdM - Gear Case Lubrication
* VOTES / MOVATS Testing
* PM - Sample Switch Case Lubricant
Check Valve
* PdM Acoustic
* PM - Sample
FEG Boundary and Characteristic
Manage Performance:
* One-button trending and analysis
* Automatic Gap Identification
* Expert Cause Analysis
* Expert Options Identification and
Decision Making
* Follow-up to Ensure Effectiveness
Manage Work:
* Current Life-cycle Plan
* Schedule Work to Manage Risk
and Greatest Efficiency
* Schedule then Plan Work
* Supply quality -level
parts to meet schedule and
breakdown demands
* Efficient and Quality
Maintenance and Post
Maintenance Test
* Documentation
* Feedback /
Recommendations for
Train / Develop People:
* All personnel are expert
at what they do
Maintenance Optimization
•Apply resources to those components most
important to plant safety and reliability
•Remove resources from those components
that have minimal impact on safety and
reliability and whose loss can be tolerated or
can be replaced easily
Maintenance Optimization
•Corrective maintenance
•Preventive maintenance (3 types)
–Periodic – servicing, parts, time based
–Predictive – monitoring, non-intrusive, analysis
–Planned – scheduled replacement or
refurbishment to prevent failure
PM Change Implementation Process Overview
Planning Support
Categorize PM Changes and Develop PM
Change Implementation Plan
MO Evaluation Results
(PM Basis, Changes to the PM
Program and if Applicable,
Deleted and Superseded PM's
PM Frequency Change
Components added to PMs
Changes to PM Scope
New PM's
Develop PM Change Implementation Plan
WO Planning
- PM Activity Deletions
- PM Frequency Changes
- Model Work Order Development and
- Model Work Instruction Development and
- Requests for Planning Support Activities
Performance Monitoring
- New monitoring requirements
Supply Chain
- New parts
- Obsolete parts
- Obsolescence strategy
- New maintenance practices
- New tools
- New test equipment
PM Change Scheduling
- Establish or Revise Schedule Dates
- Close or Modify Active Work Orders
PM Implementation Considerations
- Prioritize changes
- Consider criticality, as found conditions,
aggregate risk
- Implement easy changes first
- Stagger implementation of large changes
- start long lead items early
- Ensure proper sequencing of changes,
such as in superseded PM activities
- Ensure new schedule dates are aligned
with FEGs or system / train schedule
- Adhere to outage freeze milestones
- Perform risk assessments
- Integrate with the Work Management Look
Ahead process
Assess Effectiveness of PM Changes
- The effectiveness of PM changes will be
evaluated through the Performance
Monitoring / Health Reports
- Training for new tasks
- Training for new tools
- Training for new test equipment
Post Maintenance Test
- New or Modified Test
Procedures and Instructions
- New or Modified Procedures
Maintenance Optimization (MO)
33 Component Type Basis Documents
4577 PM change requests initiated
Effort Required
38 Weeks
5700 Consultant Man-Hours
2400 Internal Man-Hours
MO Implementation Results
3897 PM change requests implemented
680 PM change requests in progress
Effort Required
78 Weeks
9100 Consultant Man-Hours
5500 Internal Man-Hours
Living process – Performance
•Periodic PM and work order condition
reviews provide routine feedback to the PM
process to adjust PM frequencies and scope.
•Analysis of corrective maintenance work
considers whether PM was adequate or
should be modified, or new PMs should be
Living process – Review
•Equipment reliability process is a living process.
Although a considerable effort is committed to
perform the “optimization”, ongoing work is needed
using the same tools and methods.
–The PM review team typically meets routinely to
review PM program changes or additions.
•Work scope team meets weekly to review
upcoming planned PMs (week T-16 to T-26)
Long-Term Plan
•Generation / revenue plan
•Design planning and implementation
•Outage cycle plans
•Unit refurbishment or major component
replacement (reactor vessel head, steam
generator, major cabling)
•Equipment refurbishment (turbine overhauls,
motors, large transformers)
Generator Life Expectancies
Expected Life
•OEM Design
approx. 30 years
•Retaining Rings
20-60 years
10-30 years
•Rotor Windings
20-25 years
•Rotor Forging
30-60 years
Sources of Life Expectancy Data
•LCM Sourcebooks
•Issued for 14 component/systems:
–buried piping, breakers, condenser, ESW, FW heaters
& controls, IA, generator, turbine
•Some LCM plans are based on “engineering practice”
and are less rigorous
•World Association of Nuclear Operators
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Mete Nacar - Harbin Electric International - MS Electrical and Electronics Engineer