Implementation of a
Performance Evaluation System
for Nondestructive Testing
Methods
Daniel Algernon, Sascha Feistkorn and Michael Scherrer
SVTI Swiss Association for Technical Inspections
Nuclear Inspectorate
NDE Laboratory
Outline
Nondestructive Testing (NDT)
Meaning for Safety
(Making it Measurable)
Ensuring Reliability
(e.g. in the Nuclear Industry)
Transferring Concepts
between Industries
Conclusion
www.svti.ch
ICSC 2016 - "Making Safety Measurable"
Dr.-Ing. Daniel Algernon
Motivation
• Highly safety relevant components & industries
• Assessment of structural integrity:
Nondestructive Testing (NDT)
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ICSC 2016 - "Making Safety Measurable"
Dr.-Ing. Daniel Algernon
Nondestructive Testing (NDT)
NDT Methods
• Ultrasonic Testing
• Eddy Current Testing
• Liquid Penetrant Testing
• Magnetic Particle Testing
• Radiographic Testing
• Thermography
• Visual Testing
•…
www.svti.ch
ICSC 2016 - "Making Safety Measurable"
Dr.-Ing. Daniel Algernon
Meaning of NDT for Safety Concepts
Safety
Structural Integrity
Fracture Mechanics
Condition Assessment
Measures
Nondestructive Testing
• NDT provides safety-relevant information
• «making safety measurable» requires quantitative information
• Reliable information!
www.svti.ch
ICSC 2016 - "Making Safety Measurable"
Dr.-Ing. Daniel Algernon
NDT in the Nuclear Industry
Operation
Struct.
Integrity
Testing &
Evaluation
• Safe Operation of Nuclear Power Plants over design life time
• Long Term Operation based on actual condition
• Structural Iitegrity of safety relevant components
• Significant aspect of technical condition
• Nondestructive Testing and Evaluation (NDE)
• Provide information for condition assessment
• Information provided must be reliable, since it is the basis for determining safety
Reliability
Performance
Evaluation
Demo & TJ
www.svti.ch
• Performance Evaluation of NDE inspection systems to determine their reliability
• Performance assessed in practical demonstrations as well as theoretical investigation
(technical justification)
ICSC 2016 - "Making Safety Measurable"
Dr.-Ing. Daniel Algernon
Elements of NDT
NDT Method
Procedure
Equipment
Personnel
 NDT = Information Provider
 Value of NDT = Value of Information
Test Object
Target
Information
 Information must be relevant and reliable
 Increase in reliability = increase in value
www.svti.ch
ICSC 2016 - "Making Safety Measurable"
Dr.-Ing. Daniel Algernon
How to determine reliability?
• Theoretical Assessment
– Model & Simulation
– Field Experience
• Practical Demonstration
– «See how NDT System performs»
– Compare NDT results to true results
• How to determine truth?
– Investigate in controlled conditions
• Test blocks, simulating testing problem
www.svti.ch
ICSC 2016 - "Making Safety Measurable"
Dr.-Ing. Daniel Algernon
Requirement for Practical Demonstr.
!
Contradiction:
Realistic and Controled (Simulation)
www.svti.ch
ICSC 2016 - "Making Safety Measurable"
Dr.-Ing. Daniel Algernon
ENIQ-Methodology
European Network for Inspection and Qualification
• Qualification of Inspection Systems
– Procedure
– Equipment
– Personnel
• Case Specific Practical Demonstration
– Component and Flaw Specific
– Postulated flaw mechanism
– Realistic flaw simulation in test blocks
• Technical Justification
– Theoretical Assessment of
• Inspection System
• Suitability of Test Blocks and Test Flaws
www.svti.ch
ICSC 2016 - "Making Safety Measurable"
Dr.-Ing. Daniel Algernon
Practical Demonstrations
 Physically simulating field conditions
 Physically simulating relevant flaw types (qualification target)
 Mockups and test blocks
Example: Field Testing
www.svti.ch
Example: Qualification on test block
ICSC 2016 - "Making Safety Measurable"
Dr.-Ing. Daniel Algernon
Component, Test Block, Mockup
 Component
 Full-Scale Mockup
 Weld
 Test flaws
 Test Block
www.svti.ch
ICSC 2016 - "Making Safety Measurable"
Dr.-Ing. Daniel Algernon
Test Flaws
• Mandatory: realistic test flaws
• Example: representing intergranular stress corrosion cracking
(IGSCC)
www.svti.ch
ICSC 2016 - "Making Safety Measurable"
Dr.-Ing. Daniel Algernon
Evaluating Practical Demonstrations
 Test Set = Test block or section containing test flaws
 Test Sets are given to candidates
 Several candidates per qualification project
www.svti.ch
ICSC 2016 - "Making Safety Measurable"
Dr.-Ing. Daniel Algernon
Test set/Candidate Relation in IndEva
• IndEva: Evaluation System of Swiss Qualification Body
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ICSC 2016 - "Making Safety Measurable"
Dr.-Ing. Daniel Algernon
Graphic Representation of Testsets
 Per Test set:
 As-Built Information
 Indications reported by candidates
www.svti.ch
ICSC 2016 - "Making Safety Measurable"
Dr.-Ing. Daniel Algernon
Evaluation Types in IndEva
• Evaluation 1: Singular relation Test Set / Candidate
• Evaluation 2: By candidate and related test sets
• Evaluation 3: Procedure (all candidates and test sets)
www.svti.ch
ICSC 2016 - "Making Safety Measurable"
Dr.-Ing. Daniel Algernon
Analysis Criteria
 Detection: What percentage of flaws has been detected
 False Calls:
 In absolute numbers
 In % of actual number of test flaws
 Per area
 Determining Length and Thruwall extent: Statistics
 RMS (Root Mean Square)
 Mean + Standard deviation
 Positioning: Tolerance window
www.svti.ch
ICSC 2016 - "Making Safety Measurable"
Dr.-Ing. Daniel Algernon
IndEva-Output per Candidate
 Evaluation of each individual candidate regarding qualification criteria for
detection, characterization, length and thruwall sizing
www.svti.ch
ICSC 2016 - "Making Safety Measurable"
Dr.-Ing. Daniel Algernon
IndEva-Results by Procedure
 Total evaluation taking into account the best, worst and averaged results or
median
 Identification of critical test flaws
www.svti.ch
ICSC 2016 - "Making Safety Measurable"
Dr.-Ing. Daniel Algernon
IndEva-Results per Test Flaw (Table)
 List of all individual test flaws and the respective results obtained
www.svti.ch
ICSC 2016 - "Making Safety Measurable"
Dr.-Ing. Daniel Algernon
Qualification
Qualification = Proof (Demonstration
(Demonstration)+ofUnderstanding)
Performance
of Performance
Technical Justification (TJ)
www.svti.ch
ICSC 2016 - "Making Safety Measurable"
Dr.-Ing. Daniel Algernon
Technical Justification: Modeling
•
•
•
•
Use of semi-analytical simulation software CIVA
Powerful tool for parametric studies and technical justification
Perspective: Reduction of testing effort
Validation of model is essential, test blocks still needed!
www.svti.ch
ICSC 2016 - "Making Safety Measurable"
Dr.-Ing. Daniel Algernon
Technical Justification
Practical Trials
(Statistics)
Engineering Understanding
(Technical Justification)
Confidence
www.svti.ch
ICSC 2016 - "Making Safety Measurable"
Dr.-Ing. Daniel Algernon
Technical Justification
Practical Trials
(Statistics)
Engineering Understanding
(Technical Justification)
Confidence
Since number of test flaws and practical trials is limited,
technical justification is an important element
(e.g. in ENIQ Qualification system)
www.svti.ch
ICSC 2016 - "Making Safety Measurable"
Dr.-Ing. Daniel Algernon
Quantification of Technical Justification
Goal:
Combined statistical expression
 of practical trials and technical justification
 of results and confidence level
Approach: Bayesian Statistics
General Idea:
Prior set of parameters adjusted according to
information gained from technical justification and
practical trials, resulting in posterior set of
parameters
Based on Binomial distribution
www.svti.ch
ICSC 2016 - "Making Safety Measurable"
Dr.-Ing. Daniel Algernon
Bayesian Approach
• Gandossi & Simola, 2007
www.svti.ch
ICSC 2016 - "Making Safety Measurable"
Dr.-Ing. Daniel Algernon
Transfering Concepts between
Industries
• Example: «Nuclear2Civil»
Identification of Industry
Specific Practices and
Needs
NDT in new
Industry (Civil
Engineering)
NDT in the
Nuclear Industry
Transfer of
Quality Concepts
Industry (Civil
Engineering)
Specific Adaption
Adaption of quality-assurance (qualification) concepts to new industries
(e.g. NDT in civil engineering).
www.svti.ch
ICSC 2016 - "Making Safety Measurable"
Dr.-Ing. Daniel Algernon
Challenging Material vs. Qualification
• Inhomogeneous
material
• Individual structural
design
• Limited Budget…
Qualification of Concrete-NDT?
• Needs Adaption of Concepts!
• Current Topic for DGZfP Quality Assurance Committee
www.svti.ch
ICSC 2016 - "Making Safety Measurable"
Dr.-Ing. Daniel Algernon
Concrete-NDE Validation Center
Florida Department of Transportation
Laboratory Test Frame for automated application of
nondestructive testing in civil engineering (NDT-CE)
www.svti.ch
ICSC 2016 - "Making Safety Measurable"
Dr.-Ing. Daniel Algernon
Conclusion
Making
Safety
Measurable
Process/
Value Chain
Structural
Integrity
Quantify
NDT
Quantitative
Reliability
Qualification
Industry Specific
Adaption
www.svti.ch
ICSC 2016 - "Making Safety Measurable"
Dr.-Ing. Daniel Algernon
Thank you
www.svti.ch
ICSC 2016 - "Making Safety Measurable"
Dr.-Ing. Daniel Algernon
Conclusion
•
•
•
•
•
•
•
•
•
In many industries: NDT provides information used to rate component safety
reliability has direct effect on the operational safety of a component.
nuclear industry: qualification processes ensure NDT reliability (e.g. ENIQ)
Quantitative measures obtained from qualification target and statistical
distribution of trials
Qualification is combination of theoretical assessment (TJ) and practical
demonstration (PD)
Need: express theoretical assessment quantitatively and combine with PD
Approach: Bayesian statistics (Gandossi & Simola)
- capable, though challenging, since it requires adequate evaluation criteria.
Tool IndEva: statistical evaluation of the practical demonstration, identifying
strengths and weaknesses
- Covers TJ quantification approach, currently evaluated
Methodology Transfer: qualification process transferred to other industries, but
needs adaption
- First example established: civil engineering (concrete structures).
www.svti.ch
ICSC 2016 - "Making Safety Measurable"
Dr.-Ing. Daniel Algernon
Qualification of Inspection Systems
• Qualification = Proof (Demonstration) of Performance
• Qualification process is an important element to
ensure reliable inspections systems
• Qualification is essential especially in case of safetyrelevant compent evaluation (e.g. in nuclear power
plants)
• Swiss Association for Technical Inspections (SVTI)
serves as the NDE Qualification Body (QSt) in
Switzerland
www.svti.ch
ICSC 2016 - "Making Safety Measurable"
Dr.-Ing. Daniel Algernon
IndEva-Form for Testblocks and Flaws
As-Built Information
www.svti.ch
ICSC 2016 - "Making Safety Measurable"
Dr.-Ing. Daniel Algernon
IndEva-Candidate Indication Lists
 Taking into account coordinate offsets or scaling:
(X + Offset ax) * Faktor bx + Offset cx
(Y + Offset ay) * Faktor by + Offset cy
www.svti.ch
ICSC 2016 - "Making Safety Measurable"
Dr.-Ing. Daniel Algernon
IndEva-Results per Candidate
IndEva-Results per Candidate
IndEva-Results per Candidate
WCNDT 2016
Implementation of Performance Evaluation Methodology in INDEVA
IndEva-Results per Candidate
WCNDT 2016
Implementation of Performance Evaluation Methodology in INDEVA
IndEva-Results per Candidate
WCNDT 2016
Implementation of Performance Evaluation Methodology in INDEVA
IndEva-Results per Candidate
IndEva-Results per Test Flaw (Plot)
www.svti.ch
ICSC 2016 - "Making Safety Measurable"
Dr.-Ing. Daniel Algernon
IndEva-Results per Test Flaw
www.svti.ch
ICSC 2016 - "Making Safety Measurable"
Dr.-Ing. Daniel Algernon
IndEva-Results per Test Flaw
www.svti.ch
ICSC 2016 - "Making Safety Measurable"
Dr.-Ing. Daniel Algernon