6/21/2016

Tom Burnett & Nikhil Kumar

Intertek

Risk Based Inspection for Power Plants

AWARE UGM 2016

222

Evolving Business Models

Centralized Distributed

CapEx OpExStatic/Dumb

Connected/Smart

3

Intertek Smart Platform

AWARE + CostCom

Condition Assessment

Failure Analysis/

BTFR

High Energy Piping

Flow Accelerated Corrosion

Power Plant Cycling

Fitness for Service

EconometricsLife Extension

(Risk Adjusted)

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Why do RBI

• Improve plant and worker safety – Avoidance of catastrophic failure

• Increased availability and reliability of equipment

• Better understanding of equipment and processes

• Focus resources in correct areas

• Save money

• Improved turnaround planning

• Specific inspection and maintenance activities

• Avoid failures and downtime

• Detailed equipment inspection plans

• Follow industry best practices

• Make informed management decisions

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Hazard versus Risk

Hazard Risk

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What is RiskC

ost

Reliability

Reliability Analysis

Total Cost

Outage Cost

Capital & Maintenance

Cost

Risk = (Likelihood of Failure) x (Consequence of Failure)

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What about API compliance?

API RP 580 was intended to provide guidance and provide basic elements for

developing and implementing a RBI program. It is an introduction to concepts and

principles of RBI, with the intent of producing a documented methodology.

AWARE is fully compliant with these guidelines.

API 581 has been updated over time and now includes step by step analysis

procedures similar to ASME FFS-1 as well as ASME Section VIII

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Why was RBI Developed

• Most pressure equipment contain flaws

• Most flaws are innocuous - Don’t cause problems

• Few flaws cause catastrophic failure

• Must find (inspect) those critical flaws in high risk service - Cost effectively

• Typically 80% of the risk is associated with < 20% of the pressure

equipment

Loss of containment events resulting in major

insurance losses in petrochemical process plants.

Only about half of the causes of loss of containment

can be influenced by inspection activities (41% of

mechanical failures plus some portion of the “unknown”

failures). Other mitigation actions are required.

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• As with other industries, the goal for

the electric generation industry as a

whole is to predict and prevent

failures before they occur.

• The implementations rely on both

Qualitative Risk Analysis, as well as

a Quantitative Risk Analysis, which

includes in-depth reliability and

financial analysis.

• Level I – Qualitative risk, simple

• Level II – Qualitative risk analysis,

supplemented with quantitative

methods

• Level III – Quantitative risk analysis,

in depth analysis

RBI – Qualitative or Quantitative?

Rank

Process

Units

Review and

Adjust COF

Rating

Identify

Consequence

Modifiers

Calculate

Preliminary

Consequence Index

Gather Data for

Consequence

Estimate

Review of

Process and

Operational Data

Consequence

of Failure

(COF)

Risk Rank = COF

x LOF

Development of Equipment

Worksheet

Equipment

Documentation

Review

Review and

Adjust LOF

Rating

Calculate Initial

Damage Rank

Identify

Failure

Modes

Identify Potential

Damage

Mechanisms

Identify Industry Specific

Unit Exp.(Interviews -

Process, Maint.

Engrs./Insp.)

Likelihood of

Failure (LOF)

Risk

Directed

Inspection

Plan -

Scope &

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What does inspection planning involve:

• Determining risk in terms of

likelihood of failure and

consequence of failure

• Inspection scope, schedule, and

cost planning and risk reduction

estimations

• Presentation of the results in

terms of a risk matrix

• Evaluation of the costs and risk

reduction of countermeasures

Inspection Planning

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Intertek Approach

AWARE Decision Analysis

No detection + No Repair

Equipment Failure

Equipment Risk

Assessment

No detection + No Repair

Detection + No Repair

Detection + Repair

Detection + No Repair

Equipment Failure

Equipment Risk

Assessment

No detection + No Repair

Detection + No Repair

Detection + Repair

No detection + No Repair

Equipment Failure

Equipment Risk

AssessmentDetection +

Repair

Risk Mitigation

Plan

Inspection Plan

Risk Matrix

Data Analysis

[Determine POF/COF]

Data Input in AWARE

Data Collection

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Factors:

• Incorrect Design

• Incorrect Material (size, schedule,

metallurgy)

• Construction Defects (lay-up,

welds)

• In Service Induced Defects

(corrosion, erosion, fatigue, creep,

creep/fatigue, etc.)

• Cycling

• Operational and Maintenance

Caused Defects

• Define Damage Potential

• Identify Potential Failure Mechanisms

• Determine Potential Failure Modes for Damage Mechanisms

• Assign Damage Rank Based on:

• Possibility of Occurrence

• Failure Mode if Undetected

• Consider Mitigating/Aggravating Factors and Assign an Overall Likelihood of Failure Rank to Component Considering:

• Corrosion, erosion, fatigue, creep, creep/fatigue, etc.

• Operating Considerations

• Thermal Cycles, Stress Cycles, Transients and Off Normal Operations

• Inspection Considerations - Scope, Frequency, and Technique

• Quality of Documentation and Plant Experience

Likelihood of Failure

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− Reliability Models for

certain key equipment

(High Energy Piping or

Pressure Vessels),

where damage

mechanisms and

uncertainties are well

understood and

statistical distributions

are available. In this

scenario, the model uses

the following equation to

determine POF:

• 𝑃𝑓 𝑡 = 𝑔𝑓𝑓. 𝐷𝑓 𝑡 . 𝐹𝑀,

where 𝑃𝑓 𝑡 is the function

of a generic failure

frequency 𝑔𝑓𝑓, damage

factor 𝐷𝑓(𝑡), and a

management system

factor 𝐹𝑀

− Statistical Models. These models are based on generic data collected either using frequencies available in the AWARE database or other models developed by Intertek Engineering. We will also rely on EPRI data to develop and determine the POF.

• Where appropriate, two parameter Weibull models will be used to estimate failure frequency, 𝑃𝑓 𝑡 =

1 − exp[−𝑡

𝐶𝐿′

𝐵] ; where:

CL’ is the updated characteristic life and B is the shape factor

• For some key boiler pressure parts Intertek’s probabilistic failure rate damage models such as TUBETECH or SAFESEAM, or SAFEGIRTH will be used to estimate the likelihood (i.e., probability, frequency) of failure

− Expert Judgment. will be

relied upon when the

information on likely

damage mechanism or

failure frequency is

found inadequate.

Likelihood of Failure

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Possible Consequence:

(a) formation of a vapor cloud that could

ignite, causing injury and equipment

damage

(b) release of a toxic chemical that could

cause health problems

(c) a spill that could cause environmental

damage

(d) a rapid release of superheated steam

that could cause damage and injury

(e) a forced unit shutdown that could

have an adverse economic impact

(f) minimal safety, health, environmental,

and/or economic impact

• Calculate Consequence Value

• Worst Case Pressure & Temperature

• Volume of Contained Fluid/Gas

• Density Factor

• NFPA Factors (Flammability, Toxicity, Reactivity, Other)

• Assign Consequence Rank to Component Considering Mitigating/Aggravating Factors

• Location Relative to Other Equipment

• Location Relative to Concentrations of Personnel

• Environmental Factors (Reportable Release Quantities)

Consequence of Failure

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• Calculate Preliminary Consequence Value (PCV)

• Product of Worst Case: Temperature, Volume, Pressure and Density factors.

• Sum of MSDS Factors: Flammability, Toxicity, Reactivity, Other (steam).

• Final Product (PCV)

• Modify PCV by considering Mitigating, Aggravating Factors

• Location Relative to Other Equipment

• Location Relative to Concentrations of Personnel

• Environmental Factors (Reportable Release Quantities)

• Fire detection and suppression devices

Estimating Consequence

Four Categories Based Consistent With Industry Approach

Consequence of Component Failure

Considerable 1

Serious 2

Some 3

Minor or No Impact on Personnel 4

Rank Consequence Based on

Potential For Harm to Site

Personnel & Environment

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RBI pitfalls

RBI will not compensate for

• inaccurate or missing information

• inadequate design or faulty equipment

• improper installation and/or operation

• operating outside the acceptable design envelope

• not effectively implementing the inspection plan

• lack of qualified personnel or team work

• lack of sound engineering or operational judgment

• failure to promptly take corrective action or implement appropriate mitigation

strategies

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Risk Management

Reducing likelihood of failure is not only restricted to inspections:

• Inspection and Maintenance

• Understanding damage

• Correct NDE techniques

• MOC/Record Keeping/Report

• Repair, Replace, Control

• Operational Controls

• Online Monitoring

• Materials

RBI focuses on “inspectable risk”. RBI is not intended to replace

other practices that have proven satisfactory or substitute for the

judgment of a responsible, qualified inspector or engineer.

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Life Optimization Program

• What is Intertek’s AIM Life

Optimization Program:

• API 580 Compliant

• System Risk Analysis Tool

• Justification for future maintenance

costs and maintenance planning aid

• A Living document

• Flexible and adaptable to changing

management and operations

• Easy to use and inexpensive, with a

quick ROI.

A typical RBI implementation results in an inspection plan as the primary output. Instead, Intertek’s program

goes beyond the basic requirements of RBI and its objectives are:

• Organizing and maintaining key inspection and overhaul reports from past years

• Developing inspection and real-time data acquisition plans needed to assess equipment health

• Developing a database structure to organize the vast data in a way that is easily retrieved and

disseminated