Usnrc Tech Guide on Nde

Nondestructive Examination (NDE) Technology and Codes Student Manual

Volume 1

Chapter 1.0

Introduction

NDE Technology and Codes Student Manual Vol I Table of Contents

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TABLE OF CONTENTS VOL I (CHAPTERS 1-5)

1.0 INTRODUCTION .................................................................................................................. 1

Learning Objectives

1.1_ Overview of Course .......................................................................................................... 1

1.2 Human Factors .................................................................................................................. 2

1.2.1 Examiner Errors .................................................................................................... 2

1.2.1.1 Technique Errors ...................................................................................... 2

1.2.1.2 Inadvertent Errors ..................................................................................... 3

1.2.1.3 Procedural Errors ...................................................................................... 4

1.2.1.4 Conscious Errors....................................................................................... 4

1.2.2 Environmental 5

2.0 PERSONNEL QUALIFICATION AND CERTIFICATION ...................................................... 1

Learning Objectives

2.1 Qualification vs. Certification ................................................................................................ 1

2.2 Employer-Based Certification vs. Centralized Certification .................................................. 1

2.3 Employer-Based Certification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

2.3.1 SNT-TC-1A. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

2.3.1.1 Benefits of SNT-TC-1A ........................................................................... 3

2.3.1.2 Limitations of SNT-TC-1A ...................................................................... 4


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2.3.1.3 Terminology ............................................................................................. 6

2.3.2 ASNT Certification Standard (ANSI/ASNT CP-189) .......................................... 7

2.3.3 Qualification of Personnel for Visual Examination ............................................. 8

2.3.4 Qualification Requirements for Ultrasonic Examination Personnel .................... 9

2.4 ISO 9712 Central Certification ............................................................................................... 9

2.4.1 Term of Certification .......................................................................................... 10

2.4.2 Renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11

2.4.3 Recertification 11

2.5 ASNT Central Certification Program (ACCP) ..................................................................... 11

2.6 AWS Certification of Welding Inspectors (CWI) ................................................................ 11

2.7 Supplemental Qualification Requirements ........................................................................... 12

3.0 CLASSIFICATION AND INTERPRETATION OF INDICATIONS ........................................ 1

Learning Objectives

3.1 Indications ........................................................................................................... 1

3.2 False Indications ..................................................................................................................... 1

3.2.1 Penetrant Examination .......................................................................................... 1


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3.2.2 Magnetic Particle Examination ............................................................................ 2

3.2.3 Radiographic Examination ................................................................................... 2

3.2.4 Ultrasonic/Eddy Current Examination ................................................................. 2

3.2.5 Summary of False Indications .............................................................................. 2

3.3 Nonrelevant Indications .......................................................................................................... 2

3.3.1 Penetrant Examination .......................................................................................... 3

3.3.2 Magnetic Particle Examination ............................................................................ 3

3.3.3 Radiographic Examination ................................................................................... 4

3.3.4 Ultrasonic Examination ........................................................................................ 4

3.3.5 Eddy Current Examination ................................................................................... 4

3.3.6 Summary of Nonrelevant Indications ................................................................... 5

3.4 True Discontinuities ............................................................................................................... 5

3.4.1 Inherent Discontinuities ...................................................................................... 5

3.4.1.1 Inclusions .......................................................................................... 5

3.4.1.2 Laminations ...................................................................................... 5

3.4.1.3 Pipe ................................................................................................... 5

3.4.1.4 Seams ................................................................................................ 5

3.4.2 Primary Processing Discontinuities .................................................................... 5

3.4.2.1 Casting .............................................................................................. 6


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3.4.2.1.1 Casting Processes ............................................................................. 6

3.4.2.1.2 Casting Discontinuities ..................................................................... 7

3.4.2.2 Forging.............................................................................................. 9

3.4.2.2.1 Forging Processes ............................................................................. 9

3.4.2.2.2 Forging Discontinuities .................................................................... 9

3.4.2.3 Rolling ............................................................................................ 10

3.4.2.3.1 Rolling Process .............................................................................. 10

3.4.2.3.2 Rolling Discontinuities .................................................................. 10

3.4.2.4 Extruding ........................................................................................ 10

3.4.3 Secondary Processing Discontinuities .............................................................. 10

3.4.3.1 Tears (Machining) .......................................................................... 11

3.4.3.2 Heat Treating Cracks ...................................................................... 11

3.4.3.3 Grinding Cracks .............................................................................. 11

3.4.3.4 Forming Cracks .............................................................................. 11

3.4.4 Service Discontinuities ..................................................................................... 11

3.4.4.1 Corrosion ........................................................................................ 11

3.4.4.2 Stress Corrosion .............................................................................. 11

3.4.4.3 Microbiological Corrosion ............................................................. 12

3.4.4.4 Intergranular Corrosion .................................................................. 12

3.4.4.5 Fatigue ............................................................................................ 12

3.4.4.6 Wear ................................................................................................ 12

3.4.5 Weld Discontinuities ........................................................................................ 13

3.4.5.1 Cracks ............................................................................................. 13

3.4.5.2 Longitudinal Cracks ....................................................................... 13

3.4.5.3 Transverse Cracks ........................................................................... 14

3.4.5.4 Crater Cracks .................................................................................. 14

3.4.5.5 Porosity ........................................................................................... 14

3.4.5.6 Inclusions ........................................................................................ 14

3.4.5.7 Undercut ......................................................................................... 15


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3.4.5.8 Burn Through ................................................................................. 15

3.4.5.9 Concavity ........................................................................................ 15

3.5 Summary of True Discontinuities ....................................................................................... 15

3.5.1 Defects ........................................................................................................ 15

3.5.2 Repair Considerations....................................................................................... 15

3.6 Interpretation Summary ...................................................................................................... 16

4.0 INTRODUCTION TO VISUAL EXAMINATION ................................................................... 1

Learning Objectives

4.1 History .......................................................................................................... 1

4.2 Personnel Qualification and Certification ............................................................................ 1

4.2.1 Visual Acuity ...................................................................................................... 2

4.2.2 Equipment 2

4.2.3 Experience and Training ..................................................................................... 2

4.2.4 Procedures... ................................................................................................... 3

4.2.5 Certification .................................................................................................... 3

4.3 Principles of Visual Testing ................................................................................................. 4

4.3.1 Applications .................................................................................................... 4


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4.3.2 Visual Factors..5

4.3.3 Human Eye ......................................................................................................... 5

4.3.3.1 Refractivity ....................................................................................... 6

4.3.3.2 Distance Judgment ............................................................................ 6

4.3.3.3 Mechanism of Vision........................................................................ 7

4.3.3.4 Light Receptors................................................................................. 7

4.3.4 Color and Color Vision....................................................................................... 7

4.3.4.1 Color Characteristics ........................................................................ 7

4.3.4.2 Brightness Characteristics ................................................................ 8

4.3.4.3 Spectrum Limits of Visibility ........................................................... 8

4.3.4.4 Color Changes .................................................................................. 8

4.3.5 Observer Differences .......................................................................................... 9

4.3.6 Lighting .......................................................................................................... 9

4.3.7 Specific Lighting Devices ................................................................................ 10

4.4 Imaging Equipment ........................................................................................................ 10

4.4.1 Mirrors ........................................................................................................ 10

4.4.2 Magnification.................................................................................................... 10

4.4.2.1 Focal Length ................................................................................... 11

4.4.2.2 Magnifying Devices ....................................................................... 11

4.4.3 Borescopes and Fiberscopes ............................................................................. 12

4.4.3.1 Borescopes ...................................................................................... 12

4.4.3.2 Fiberscopes ..................................................................................... 13


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4.4.4 Electronic Imaging ........................................................................................... 13

4.4.4.1 Closed Circuit Television ............................................................... 13

4.4.4.2 Cathode-ray Tube (Viewing) .......................................................... 13

4.4.4.3 Digital Imaging ............................................................................... 14

4.4.5 Photographic Techniques ................................................................................. 15

4.4.5.1 Depth of Field ................................................................................. 15

4.4.5.2 Lighting .......................................................................................... 16

4.4.5.3 Film ................................................................................................. 16

4.5 Measuring Equipment 16

4.5.1 Linear Scales ..................................................................................................... 17

4.5.2 Steel Rules ........................................................................................................ 16

4.5.3 The Vernier Scale ............................................................................................. 17

4.5.4 Vernier Calipers ................................................................................................ 17

4.5.5 Dial Calipers ..................................................................................................... 18

4.5.6 Micrometer ....................................................................................................... 18

4.5.7 Micrometer Depth Gages .................................................................................. 18

4.5.8 Dial Indicator .................................................................................................... 18

4.5.9 Balanced Dials .................................................................................................. 18

4.5.10 Combination Square Set ................................................................................... 19

4.5.11 Thread Pitch Gages ........................................................................................... 19


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4.5.12 Thickness Gages ............................................................................................... 19

4.5.13 Levels ........................................................................................................ 19

4.6 Visual Examination of Welds ............................................................................................. 19

4.6.1 Prior to Welding ............................................................................................... 19

4.6.2 During Welding ................................................................................................ 20

4.6.3 After Welding ................................................................................................... 20

4.6.4 Weld Examination Gages ................................................................................. 20

4.6.4.1 Fillet Weld Gage ............................................................................. 20

4.6.4.2 Multipurpose Gage ......................................................................... 21

4.6.4.3 Taper Gage ..................................................................................... 21

4.6.4.4 Hi-Lo Gage ..................................................................................... 21

4.6.4.5 Ferrite Gages ................................................................................... 21

4.7 Remote Visual Inspection (RVI) ........................................................................................ 21

4.7.1 Fiberoptic Borescopes, Fiberscopes, and Videoimagescopes .......................... 21

4.7.2 Liquid Penetrant Examinations Combined with RVI ....................................... 22

4.7.3 Magnetic Particle Examinations Combined with RVI ..................................... 23

4.7.4 Ultrasonic Examinations Combined with RVI ................................................. 23

4.7.5 Eddy Current Examinations Combined with RVI ............................................ 23


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4.8 Specific Applications for Power Generation ...................................................................... 24

4.8.1 Steam Turbines ................................................................................................. 24

4.8.2 Surface Condensers and Heat Exchangers ....................................................... 24

4.9 Visual Examination Code Requirements ............................................................................ 25

4.9.1 ASME-Section V .............................................................................................. 25

4.9.2 ASME-Section XI............................................................................................. 25

4.9.2.1 Supplemental Qualifications of

Examination Personnel ................................................................... 26

4.9.3 AWS Certified Welding Inspector ................................................................... 27

4.10 Records . . . . . . . . .27

4.11 Advantages and Limitations of Visual Testing ............................................................ 27

4.11.1 Advantages ....................................................................................................... 27

4.11.2 Limitations ........................................................................................................ 28

5.0 INTRODUCTION TO RADIOGRAPHIC EXAMINATION ................................................... 1

Learning Objectives

5.1 History . . . . . . . . . . . .......................................................................................................... 1

5.2 Personnel Qualification and Certification ............................................................................ 2


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5.3 Principles . . . . . . . . . .......................................................................................................... 3

5.3.1 Characteristics of Matter .................................................................................... 4

5.3.1.1 Atomic Weight ................................................................................. 4

5.3.1.2 Atomic Number ................................................................................ 5

5.3.1.3 Electron Configuration ..................................................................... 5

5.3.2 Radiation Theory ................................................................................................ 5

5.3.2.1 Radiation Characteristics .................................................................. 5

5.3.2.2 Interaction with Matter ..................................................................... 6

5.3.2.3 Radiation Measurement .................................................................... 9

5.3.3 Radioactive Isotopes ......................................................................................... 10

5.3.3.1 Characteristics of an Isotope ........................................................... 10

5.3.3.2 Production of Radioactive Isotopes ................................................ 11

5.3.3.3 Radioactive Decay .......................................................................... 11

5.3.4 Generation of X-rays ........................................................................................ 12

5.3.4.1 Theory of Generation ...................................................................... 12

5.3.4.2 X-ray Spectrum............................................................................... 12

5.3.4.3 Milliampere-Time or Exposure ...................................................... 13

5.3.4.4 Effective vs. Actual Focal Spot Size .............................................. 13

5.3.5 Geometric Factors ............................................................................................. 13

5.3.5.1 Definition ........................................................................................ 14

5.3.5.2 Contrast ........................................................................................... 15

5.3.6 Exposure Considerations .................................................................................. 16

5.3.6.1 Inverse Square Law ........................................................................ 17

5.3.6.2 Reciprocity Law ............................................................................. 18

5.3.6.3 Film Density ................................................................................... 18


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5.3.6.4 Film Characteristic Curves ............................................................. 18

5.3.6.5 Exposure vs. Density ...................................................................... 19

5.3.6.6 Gamma Ray Exposure .................................................................... 19

5.4 Equipment. . . . . . . . . ........................................................................................................ 19

5.4.1 X-ray Machines ................................................................................................ 19

5.4.2 Isotope Exposure Devices ................................................................................ 20

5.4.3 Radiographic Film ............................................................................................ 21

5.4.3.1 Composition.................................................................................... 21

5.4.3.2 Lead Screens ................................................................................... 21

5.4.4 Film Processing ................................................................................................ 21

5.4.4.1 Manual System ............................................................................... 22

5.4.4.2 Automatic System........................................................................... 22

5.5 Techniques. . ... . . . . .. .......................................................................................................... 22

5.5.1 Single Wall Exposure/Single Wall Viewing ...................................................... 22

5.5.2 Double Wall Exposure/Double Wall Viewing ................................................... 23

5.5.3 Double Wall Exposure/Single Wall Viewing ..................................................... 23

5.5.4 Multiple Film Techniques .................................................................................. 23

5.5.5 Coverage .. .......................................................................................................... 23

5.5.6 Use of Blocks and Step Wedges ......................................................................... 23

5.5.7 Penetrameter Placement ..................................................................................... 23


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5.5.8 Structural Welds ................................................................................................. 24

5.6 Radiographic Quality . ....................................................................................................... 24

5.6.1 Image Quality Indicators .................................................................................... 24

5.6.1.1 ...... Hole Type IQIs ................................................................................. 24

5.6.1.2 ...... Wire IQIs .......................................................................................... 24

5.6.1.3 ...... Penetrameter Requirements .............................................................. 24

5.6.2 Density ..... .......................................................................................................... 25

5.6.3 Improper Use of Penetrameters .......................................................................... 25

5.6.4 Radiographic Film Identification ........................................................................ 25

5.7 Film Viewing Considerations ............................................................................................... 26

5.7.1 High Intensity Illuminators ................................................................................. 26

5.7.1.1 ...... Heat ................................................................................................... 27

5.7.1.2 ...... Diffusion ........................................................................................... 27

5.7.13 ....... Intensity Control ............................................................................... 27

5.7.1.4 ...... Masks ................................................................................................ 27

5.7.1.5 ...... Precautions........................................................................................ 27

5.7.1.6 ...... Magnifiers ......................................................................................... 28

5.7.1.7 ...... Other Viewing Accessories .............................................................. 28

5.8 Interpretation of Radiographs ............................................................................................... 28

5.8.1 False Indications (Artifacts) ............................................................................... 28

5.8.2 Radiographic Image of Discontinuities .............................................................. 30


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5.8.2.1 ...... Weld Discontinuities ........................................................................ 30

5.8.2.2 ...... Casting Discontinuities ..................................................................... 30

5.9 Code Considerations .. ....................................................................................................... 31

5.10 Safety Concerns ... .......................................................................................................... 32

5.11 Advantages and Limitations of Radiographic Examination ........................................... 32

5.11.1 Advantages ......................................................................................................... 32

5.11.2 Limitations .......................................................................................................... 33


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TABLE OF CONTENTS

VOL II (CHAPTERS 6-9)

6.0 INTRODUCTION TO LIQUID PENETRANT EXAMINATION . . . . . . . . . . . . . . . . . . . . . . .1

Learning Objectives

6.1 History. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1

6.2 Personnel Qualification and Certification .............................................................................. 1

6.3 Principles. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

6.3.1 Capillary Action ................................................................................................... 3

6.3.2 Contact Angle ....................................................................................................... 3

6.3.3 Contrast Ratio ....................................................................................................... 3

6.4 Prerequisites............................................................................................................................ 4

6.5 Penetrant Materials ................................................................................................................. 4

6.5.1 Precleaners ............................................................................................................ 4

6.5.1.1 Selection of Cleaning Technique ................................................... 4

6.5.1.2 ...... Typical Cleaning Techniques ............................................................. 4

6.5.1.3 ...... Cleaning Precautions .......................................................................... 5

6.5.1.4 Drying Process ............................................................................... 5

6.5.2 Penetrants.............................................................................................................. 6

6.5.2.1 Penetrant Family ........................................................................... 6

6.5.2.2 Technique Selection .................................................................... 6


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6.5.3 Developers ............................................................................................................ 6

6.5.3.1 ...... Properties ............................................................................................ 6

6.5.3.2 Developer Types ............................................................................. 7

6.6 Penetrant Techniques ............................................................................................................ 7

6.6.1 Water Washable .................................................................................................... 7

6.6.1.1 Water Washable (Fluorescent) ..................................................... 8

6.6.1.2 Water Washable (Visible) ............................................................. 8

6.6.2 Post Emulsifiable .................................................................................................. 9

6.6.2.1 Post Emulsifiable (Fluorescent) .................................................... 9

6.6.2.2 Post Emulsifiable (Visible) ........................................................... 9

6.6.3 Solvent Removable ............................................................................................. 10

6.6.3.1 Solvent Removable (Fluorescent) ............................................... 10

6.6.3.2 Solvent Removable (Visible) ...................................................... 11

6.6.4 Compatibility ...................................................................................................... 11

6.7 Procedures 11

6.7.1 Penetrant Application ......................................................................................... 12

6.7.2 Penetrant Dwell Time ......................................................................................... 12

6.7.3 Removal of Excess Surface Penetrant ................................................................ 12

6.7.3.1 Method A (Water Washable) ...................................................... 12

6.7.3.2 Method B (Lipophilic Emulsifier) .............................................. 12

6.7.3.3 Method D (Hydrophilic Emulsifier) ........................................... 13

6.7.3.4 Method C (Solvents) ................................................................... 13


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6.7.4 Drying ................................................................................................................. 14

6.7.5 Development ....................................................................................................... 14

6.7.5.1 Dry Developer ............................................................................ 14

6.7.5.2 Aqueous Wet Developer ............................................................. 14

6.7.5.3 Nonaqueous Wet Developer ....................................................... 14

6.7.6 Evaluation ...15

6.7.7 Post Cleaning ...................................................................................................... 15

6.8 Procedure Qualification ........................................................................................................ 15

6.9 Nonstandard Temperatures ................................................................................................... 15

6.10 Control Panels................................................................................................................. 16

6.10.1 Limitation of Test Panels .................................................................................... 16

6.11 Penetrant Systems ........................................................................................................... 16

6.11.1 Precleaning Station ............................................................................................. 16

6.11.2 Penetrant Application Station ............................................................................. 16

6.11.3 Penetrant Draining Station.................................................................................. 16

6.11.4 Emulsifier Application Station ........................................................................... 17

6.11.5 Washing or Rinsing Station ................................................................................ 17


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6.11.6 Developer Application Station ........................................................................... 17

6.11.7 Drying Station..................................................................................................... 17

6.11.8 Examination Station ........................................................................................... 17

6.11.9 Post-cleaning Station .......................................................................................... 17

6.12 Portable Systems.. .......................................................................................................... 17

6.12.1 Black Lights ........................................................................................................ 18

6.13 Examination Procedure ................................................................................................... 18

6.13.1 Procedure Revision ............................................................................................. 18

6.14 Applications .................................................................................................................... 19

6.14.1 Welds ................................................................................................................ 19

6.14.2 Castings ... .......................................................................................................... 19

6.14.3 Through Leaks .................................................................................................... 19

6.15 Unacceptable Techniques ............................................................................................... 19

6.16 Variables ......................................................................................................................... 19

6.17 Evaluation ....................................................................................................................... 20

6.17.1 Indications. ......................................................................................................... 20

6.17.1.1 False Indications ............................................................................... 20

6.17.1.2 Nonrelevant Indications .................................................................... 20

6.17.1.3 True Indications ................................................................................ 20


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6.17.2 Interpretation ...................................................................................................... 21

6.17.2.1 Visible Daylight Dye Penetrants....................................................... 21

6.17.2.2 Fluorescent Penetrants .................................................................... 21

6.17.3 Specific Types of Discontinuities ....................................................................... 22

6.17.4 Discontinuity Indication Categories ................................................................... 22

6.18 Advantages and Limitations of Penetrant Examination ................................................. 23

6.18.1 Advantages ......................................................................................................... 23

6.18.2 Limitations .......................................................................................................... 23

7.0 INTRODUCTION TO MAGNETIC PARTICLE EXAMINATION. . . . . . . . . . . . .. . . . . . .1

Learning Objectives

7.1 History. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1

7.2 Personnel Qualification and Certification .............................................................................. 1

7.3 Principles. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2

7.3.1 Key Terms .3

7.3.2 Theory of Magnetism ........................................................................................... 4

7.3.2.1 Horseshoe Magnet .......................................................................... 4

7.3.2.2 Bar Magnet ..................................................................................... 5

7.3.2.3 Flux Line Characteristics ................................................................ 5

7.3.2.4 ...... Classification of Materials .................................................................. 5

7.3.2.5 ...... Molecular Theory ............................................................................... 6


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7.3.2.6 ...... Leakage Fields .................................................................................... 6

7.3.2.7 ...... Hysteresis Loop .................................................................................. 6

7.4 Producing Magnetic Fields ..................................................................................................... 7

7.4.1 Induced Magnetic Fields ...................................................................................... 7

7.4.1.1 Permanent Magnets ........................................................................ 7

7.4.1.2 Electromagnets ............................................................................... 7

7.4.2 Circular Magnetization ......................................................................................... 7

7.4.2.1 Direct Magnetization ................................................................................ 8

7.4.2.2 Indirect Magnetization .............................................................................. 9

7.4.2.3 Equipment ................................................................................................. 9

7.4.2.4 Field Strength Calculations ...................................................................... 9

7.4.2.5 Code Requirements - Circular ................................................................ 10

7.4.2.5.1 Direct Contact Technique (Head Shot) .......................................... 10

7.4.2.5.2 Central Conductor............................................................................. 10

7.4.2.5.3 Prods ................................................................................................. 11

7.4.3 Longitudinal Magnetization ............................................................................... 11

7.4.3.1 Coil Shot ................................................................................................. 12

7.4.3.2 Cable Wrap ............................................................................................. 12

7.4.3.3 Quick Break Technique .......................................................................... 12

7.4.3.4 Equipment ............................................................................................... 13

7.4.3.5 Coil Field Strength Calculations............................................................. 13

7.4.3.6 Code Requirements - Longitudinal......................................................... 13

7.4.4 Field Direction .................................................................................................... 14

7.4.5 Multidirectional Magnetic Fields ....................................................................... 14

7.4.6 Magnetizing Current ........................................................................................... 14


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7.5 Techniques ............................................................................................................................ 16

7.5.1 Continuous .................................................................................................... 16

7.5.2 Residual .................................................................................................... 16

7.6 Magnetic Particles 16

7.6.1 Visible Particles - Wet ........................................................................................ 16

7.6.2 Fluorescent Particles - Wet ................................................................................. 16

7.6.3 Advantages of Wet Particles ............................................................................... 17

7.6.4 Limitations of Wet Particles ............................................................................... 17

7.6.5 Dry Particles .................................................................................................... 17

7.6.6 Advantages of Dry Particles ............................................................................... 18

7.6.7 Limitations of Dry Particles ............................................................................... 18

7.6.8 Particle Characteristics ....................................................................................... 18

7.6.8.1 Wet Particle Concentration ..................................................................... 18

7.6.8.2 Particle Size ............................................................................................ 18

7.6.8.3 Particles for Wet Suspension .................................................................. 18

7.6.8.4 Particle Shape ......................................................................................... 19

7.6.8.5 Magnetic Particle Properties ................................................................... 19

7.6.8.6 Particle Mobility ..................................................................................... 19


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7.7 Stationary Equipment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

7.8 Portable Equipment .............................................................................................................. 21

7.8.1 Yokes . . . ............................................................................................... 21

7.8.1.1 Electro-Magnet Yoke ............................................................................. 21

7.8.1.2 Permanent Magnet Yoke ........................................................................ 21

7.8.2 Prods .................................................................................................... 21

7.8.2.1 Contact Prods .......................................................................................... 21

7.8.2.2 Contact Clamps....................................................................................... 22

7.8.3 Coils .................................................................................................... 22

7.8.3.1 Hand-Held Coil....................................................................................... 22

7.8.3.2 Cable Wrap ............................................................................................. 22

7.9 Applications .......................................................................................................................... 22

7.9.1 Solid Cylindrical Parts ........................................................................................ 22

7.9.2 Hollow Cylindrical Parts .................................................................................... 22

7.9.3 Welds .................................................................................................... 23

7.9.4 Castings .................................................................................................... 23

7.10 Demagnetization ............................................................................................................. 23

7.10.1 Principles of Demagnetization ............................................................................ 23

7.10.2 Measuring Residual Fields ................................................................................. 25

7.11 Procedure Requirements ................................................................................................. 25


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7.12 Calibration..25

7.12.1 Frequency .................................................................................................... 25

7.12.2 Tolerance .................................................................................................... 25

7.12.3 Procedure .................................................................................................... 25

7.12.4 Yoke Calibration................................................................................................. 26

7.13 Surface Preparation .................................................................................................... 26

7.14 Magnetic Field Verification ............................................................................................ 26

7.15 Evaluation ...26

7.15.1 Evaluation Terms ................................................................................................ 26

7.15.1.1 Indications ........................................................................................ 26

7.15.1.2 Nonrelevant Indications .................................................................... 27

7.15.1.3 Interpretation of Nonrelevant Indications......................................... 28

7.15.1.4 True Discontinuity Indications ......................................................... 28

7.15.2 Evaluation Guide ................................................................................................ 28

7.16 Recording........................................................................................................................ 29

7.17 Advantages and Limitations of Magnetic Particle Testing ............................................ 29

7.17.1 Advantages .................................................................................................... 29

7.17.2 Limitations .................................................................................................... 29


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8.0 INTRODUCTION TO ULTRASONIC EXAMINATION .......................................................... 1

Learning Objectives

8.1 History. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1

8.2 Personnel Qualification and Certification ................................................................................. 1

8.2.1 ASME Section V ..................................................................................................... 1

8.2.2 ASME Section XI .................................................................................................... 2

8.3 Principles. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

8.3.1 Frequency ......................................................................................................... 4

8.3.2 Velocity ......................................................................................................... 4

8.3.3 Wavelength ......................................................................................................... 5

8.3.4 Transmission/Reflection .......................................................................................... 5

8.3.5 Attenuation ......................................................................................................... 6

8.3.6 Instrumentation and Control .................................................................................... 6

8.3.7 Ultrasonic Wave Propagation .................................................................................. 6

8.3.7.1 Acoustic Impedance .................................................................................... 7

8.3.7.2 Reflection at Interfaces ................................................................................ 8

8.3.7.3 Fresnel Zone ................................................................................................ 8

8.3.7.4 Fraunhofer Zone (Far Field) ........................................................................ 9

8.3.7.5 Dead Zone .................................................................................................... 9


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8.3.8 Refraction ......................................................................................................... 9

8.3.8.1 Snells Law .................................................................................................. 9

8.3.8.2 First and Second Critical Angles ............................................................... 10

8.3.9 Ultrasonic Examination Variables ......................................................................... 11

8.3.9.1 Equipment .................................................................................................. 11

8.3.9.2 Transducers ................................................................................................ 12

8.3.9.3 Couplant..................................................................................................... 13

8.3.9.4 Scanning Techniques ................................................................................. 13

8.3.9.5 Part Structure ............................................................................................. 13

8.3.9.6 Surface Condition ...................................................................................... 13

8.3.9.7 Part Geometry and Size ............................................................................. 13

8.3.9.8 Discontinuity Type, Shape, and Orientation ............................................. 14

8.4 Equipment 14

8.4.1 Ultrasonic Transducers .......................................................................................... 14

8.4.1.1 Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

8.4.1.2 Care of Transducers ................................................................................... 14

8.4.2 Base Pulse-Echo Instrumentation .......................................................................... 15

8.4.2.1 Time base ................................................................................................... 15

8.4.2.2 Clock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16

8.4.2.3 Pulse Repetition Rate................................................................................. 16

8.4.2.4 Pulser-Receiver .......................................................................................... 16

8.4.2.5 Basic Controls............................................................................................ 16

8.4.2.6 Gates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

8.5 Procedures. .............................................................................................................................. 17

8.5.1 Application of the Various Wave Modes .............................................................. 18

8.5.1.1 Compressional Wave Applications ........................................................... 18


USNRC Technical Training Center Rev 0103 xxv

8.5.1.2 Shear Waves .............................................................................................. 18

8.5.1.3 Surface Waves ........................................................................................... 18

8.5.1.4 Lamb Waves .............................................................................................. 18

8.5.2 Immersion Testing ................................................................................................. 18

8.5.2.1 Immersion Tanks and System Components .............................................. 18

8.5.2.2 Immersion Transducers ............................................................................. 19

8.5.3 Data Display ....................................................................................................... 20

8.5.3.1 A-Scan20

8.5.3.2 B-Scan. .............................................................................................. 20

8.5.3.3 C-Scan. ...................................................................................................... 20

8.5.4 Calibration Techniques .......................................................................................... 21

8.5.4.1 Linearity..................................................................................................... 21

8.5.4.2 Distance Amplitude ................................................................................... 22

8.5.4.3 Resolution .................................................................................................. 23

8.5.4.4 Beam Profile .............................................................................................. 23

8.5.4.5 Test Block Parameters ............................................................................... 23

8.5.5 Unacceptable Techniques ...................................................................................... 23

8.5.5.1 Scanning Problems .................................................................................... 23

8.5.5.2 Interpretation Shortcomings ...................................................................... 23

8.5.5.3 Report Format Problems ............................................................................ 23

8.6 Interpretation and Code Requirements .............................................................................. 24

8.6.1 Weld Calibration Standards ................................................................................... 24

8.6.2 Evaluation .............................................................................................................. 25

8.6.2.1 False Indications ........................................................................................ 25

8.6.2.2 Nonrelevant Indications ............................................................................. 25

8.6.2.3 Relevant Discontinuity Indications ........................................................... 25


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8.6.3 Recording............................................................................................................... 26

8.6.3.1 Use of Examination Forms ........................................................................ 26

8.6.3.2 Recording Techniques ............................................................................... 26

8.7 Advantages and Limitations of Ultrasonic Examination ......................................................... 26

8.7.1 Advantages ............................................................................................................ 26

8.7.2 Limitations ............................................................................................................. 26

9.0 INTRODUCTION TO EDDY CURRENT TESTING EXAMINATION. . . . . . . . . . . . . . . . . . . .1

Learning Objectives

9.1 History. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1

9.2 Personnel Qualification and Certification. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2

9.3 Principles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ... . 3

9.3.1 Electromagnetic Induction ........................................................................................... 4

9.3.2 Eddy Current Characteristics ....................................................................................... 4

9.3.2.1 Material Properties ................................................................................... 5

9.3.2.1.1 Conductivity ............................................................................................. 5

9.3.2.1.2 Permeability .............................................................................................. 6

9.3.2.1.3 Test Display of Material Property Variations ........................................... 6

9.3.2.2 Frequency ................................................................................................. 6

9.3.2.3 Test Specimen Geometry .......................................................................... 7

9.3.2.4 Coil Design ............................................................................................... 7

9.3.2.4.1 Coil Coupling (Lift-Off) ........................................................................... 7

9.3.2.4.2 Edge Effect ............................................................................................... 8


USNRC Technical Training Center Rev 0103 xxvii

9.4 Equipment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

9.4.1 System Components ............................................................................................. 8

9.4.2 Data/Displays .................................................................................................... 10

9.4.2.1 Lift-Off Curves ....................................................................................... 10

9.4.2.2 Conductivity Curve................................................................................. 10

9.4.2.3 Thickness Curves .................................................................................... 10

9.4.2.4 Discontinuity Signal Display .................................................................. 11

9.4.3 Basic Coils .................................................................................................... 12

9.4.3.1 Surface Coils........................................................................................... 12

9.4.3.2 Encircling Coils ...................................................................................... 12

9.4.3.3 Internal Coils .......................................................................................... 13

9.5 Techniques .................................................................................................... 13

9.5.1 Impedance Plane Fundamentals ......................................................................... 13

9.5.2 Impedance Plane Response to Conductivity Variations ..................................... 13

9.5.3 Sorting .14

9.5.4 Discontinuities .................................................................................................... 14

9.5.4.1 Discontinuity Location in Installed Nonferrous Steam Generator

Heat Exchanger Tubing .......................................................................... 14

9.5.4.2 Calibration Procedure ............................................................................. 15

9.5.4.3 Probe Speed ............................................................................................ 16

9.5.5 Thickness .................................................................................................... 16

9.5.5.1 Location of Secondary Layer Corrosion or Cracking ............................ 16


USNRC Technical Training Center Rev 0103 xxviii

9.5.6 Coatings .................................................................................................... 17

9.5.6.1 Variations in Thickness of Plating or Cladding...................................... 17

9.6 Interpretation and Code Requirements ................................................................................. 17

9.6.1 Written Procedure ............................................................................................... 17

9.6.2 Description of Method ........................................................................................ 17

9.6.3 Reference Specimen ........................................................................................... 18

9.6.4 Equipment Qualification ..................................................................................... 18

9.6.5 Procedure Requirements ..................................................................................... 18

9.7 Advantages and Limitations of ET Examinations ................................................................ 18

9.7.1 Advantages .................................................................................................... 18

9.7.2 Limitations .................................................................................................... 18

*Tables and figures are listed in separate Table of Contents that are available for each chapter.

NDE Technology and Codes Student Manual Table of Contents

USNRC Technical Training Center Rev 0103 1i

TABLE OF CONTENTS 1.0 INTRODUCTION .................................................................................................................. 1 Learning Objectives

1.1 Overview of Course .......................................................................................................... 1

1.2 Human Factors .................................................................................................................. 2

1.2.1 Examiner Errors .................................................................................................... 2 1.2.1.1 Technique Errors ...................................................................................... 2 1.2.1.2 Inadvertent Errors ..................................................................................... 3 1.2.1.3 Procedural Errors ...................................................................................... 4 1.2.1.4 Conscious Errors....................................................................................... 4

1.2.2 Environmental ...5

NDE Technology and Codes Chapter 1.0 Student Manual Introduction

USNRC Technical Training Center Rev 0409 11

1.0 INTRODUCTION Learning Objectives: To enable the student to: 1. Understand the importance of nondestructive

examination (NDE). 2. Identify the international interest in NDE. 3. Identify sources of errors that can occur.

1.1 Overview of Course

It is of great importance that both individual components and complete engineering assemblies and structures are free from damaging defects and other possible causes of premature failure. A whole series of examination instruments and techniques have evolved over the years and new methods are still being developed to assist in the process of assessing the integrity and reliability of parts and assemblies. Nondestructive examination methods are widely used in industry for checking the quality of

Electro-Technical Commission (IEC) for electrical standards. In the United States, the American National Standards Institute (ANSI) is the official member of the ISO and IEC.

In the United States, there are 29 National Standards organizations and hundreds of organi-zations worldwide. In addition, there are thou-sands of ISO and IEC standards committees and subcommittees.

There are also dozens of governmental agen-cies that are concerned with the institution of national and international standards.

It takes time to develop adequate procedures and standards for new instruments and new technology. It takes even more time to obtain universal agreement on these standards.

Because of the continuing changes taking place, the information in this manual is for reference purposes only. The information herein should not be taken as authoritative over any formally issued specification, standard, procedure, technique, or instruction.

This manual provides basic background information needed by students, NDE personnel, and managers who want to study the most commonly used NDE methods.

For control of NDE applications and proce-dural quality, international standards are being continuously evolved and developed through two major nongovernmental bodies, the International Organization for Standardization (ISO), for non-electrical standards, and the International

The field of NDE is more dynamic today than ever before. Many of the major technical societies, such as the American Society for Nondestructive Testing (ASNT), the American Society for Metals (ASM), the American Society for Quality (ASQ), the American Welding Society (AWS), and the American Society for Testing and Materials (ASTM) are deeply involved in nondestructive examination and are leading the drive for better understanding



through information dissemination and standardization. 1.2 Human Factors 1.2.1 Examiner Errors

While regulatory agencies can write the most detailed regulations and companies can devise the most sophisticated quality programs and procedures, it still remains that the actions of individual examiners will ultimately determine the success or failure of those programs. It is the human factor that contributes to examiner errors. These errors can have varying causes: Technique errors, Inadvertent errors, Procedural errors, and Conscious errors.

The various causes of examiner errors when taken collectively show an accuracy of about 80 percent. This means that the average group of examiners will find about 80 percent of flaws while missing 20 percent. Worldwide studies have shown this to be an accurate measure of examiner reliability. 1.2.1.1 Technique Errors

There can be several categories addressed under this topic but the most important is job knowledge. Have the examiners been properly trained to perform the required job? In NDE there can be no guarantee that an examination is

performed properly unless the examiner has been trained and properly evaluated by written and practical examinations.

Other causes are physical, such as color blindness; lack of skill due to lack of natural aptitude; or lack of basic education.

A good internal audit system is necessary to evaluate examiners and to assure that these errors are identified before serious problems occur. Management must provide the examiner with feedback. Without this feedback there will be no change in performance.

Management should look at the most successful examiners and find what trait makes them superior performers. These methods should then be transferred to all examiners through additional training or technology.

Where an examiners performance is due to lack of ability, additional training may yield little results. Management can evaluate the examination procedures to see if the procedures can be simplified, or they can reassign the examiner to a job equal to the individuals capacity.

The most effective means to assure that examiners can perform required tasks is a formal certification program. A complete certification program should include: Formal training program,



Detailed written and practical (demonstration on controlled test samples) examinations,

Documentation attesting to the training and examinations,

Periodic renewal of the certification, and A strong internal audit program to assure

performance. 1.2.1.2 Inadvertent Errors

The majority of examiners want to give superior performance, not make errors. However, no matter how well trained or how well intentioned the examiner is, there will be inadvertent errors. The human factor does not allow for perfection.

It is widely assumed and believed by many that 100 percent examination means 100 percent of the discontinuities will be found. As indicated in Section 1.2.1, studies show that examiners only find about 80 percent of the discontinuities.

One example that demonstrates examination fallibility follows:

Federal fuses are the results of years of scientific study combined with the experience of years.

The sentence is flashed before an audience

for 30 seconds to a minute. Each member is asked to count and record the number of times the letter F appears. When the results are tallied, only about 80 percent have been found. The existence of such an extensive error rate has

stimulated many studies to determine why and to reduce this error rate. To date there have not been conclusive answers.

Since we do not know conclusively how to prevent these errors, quality programs have attempted to build in remedies. These remedies include:

Automation - Much of the repetitive errors can be eliminated by automation. Once an instrument is set up and calibrated properly, it will not produce inadvertent errors. Many of the nondestructive examinations now performed, particularly ultrasonics and eddy current, use some type of computer for data acquisition and/or evaluation.

Checklists - Detailed checklists can be used to assure all examination steps are accomplished. An example is the checklist used by a receipt examiner to check an incoming shipment. The checklist would identify all the steps to follow to assure the order meets the requirements of the purchase order.

Comparison Standards - Comparison stan-dards are actual acceptable production pieces used for comparison with other production parts.

Templates - Templates placed on a part being examined will immediately call the examiners attention to a missing part, hole, etc.

Overlays - These are visual aids in the form of transparent sheets that can be marked and placed over the item being examined.



Templates are commonly used in radiography to lay out discontinuities or possible surface conditions. The examiner can then take the overlay and place it on a weld or casting and determine if an indication is surface or internal.

Product Design - Designers and engineers must be aware of what kind of final examination a product will require. If radiography is required, the examiner must have access to both sides of an object. If ultrasonic is required, materials and geometry are factors.

Examination Aids - The use of optical magnifiers and other devices that magnify and enhance a part help eliminate errors.

Work Schedule - If an examiner is fatigued, the individual will not be able to maintain concentration for long periods. This can present both an examination problem and a safety problem. It may be useful to reorganize the work, allow for rest periods, rotate examination activities, or enlarge the job scope to give a wider assortment of tasks. 1.2.1.3 Procedural Errors

Some errors affecting quality may be inadvertent errors caused by persons other than the examination group. Parts may be inadvertently put in the shipping area or a release area before an examination is performed. This error can be eliminated by assuring that all levels of the organization are aware of the quality program and that an adequate marking system for parts is implemented and understood by all

personnel. 1.2.1.4 Conscious Errors

Errors of this type are consciously and knowingly committed by an individual. Such errors may be shortcuts or deciding certain procedural steps are not required or add nothing to the process. These errors may be by a manager, examiner, or both. While errors of this type are committed by examiners, they are more commonly traceable to managers and engineers.

Conflicting Management Policies - Management may write an extensive quality program and state they are committed to quality, but their actions indicate that cost and delivery schedule are the real priority. Most examiners quickly learn the real priorities within a company and act accordingly.

Failure to Enforce Quality Requirements - If management consistently fails to enforce quality requirements and accepts nonconforming materials as accept-as-is, examiners will stop reporting the conditions which could potentially lead to more serious oversights.

Failure to Act - If management does not respond to examiners suggestions or complaints, they will stop raising issues and try to do their best with potentially defective equipment or deficient information.

Management Fraud - In some incidents a manager may attempt to deceive customers or



regulators with fictitious quality records. This usually requires the manager and examiner to work together.

Examiner Fraud - For numerous reasons, including undue supervisory coercion, financial gain, relationships with production personnel requesting a break, or just being lazy, many examiners have been influenced to look the other way. The solution is to use personnel of high integrity and have decisive follow-up on internal audit findings should this type of activity be uncovered.

Examiner Shortcuts - As discussed earlier, the examiner may decide that a certain procedural step can be skipped without causing a problem. The examiner may not understand the importance of the step to the overall process and must not make such independent decisions.

Flinching - Examiners occasionally face borderline examinations. For example, an indication or measurement may be just over or under tolerance. An examiner may think a measurement is close enough. However, an examiner must only accept conditions within drawing or specification tolerance. Acceptance of out-of-tolerance condi-tions must be approved by an engineer and the customer.

Measures of Examiner Accuracy - Because of the collective effect of examiner errors, it is critical to monitor examination activities. Accepting rejected items or rejecting acceptable items can be a costly and potentially hazardous problem. It should be noted that many studies

have shown examiners tend to reject more good products than accept bad products. Conscious errors can be controlled with the following: Strong management support for quality pro-

gram, Training, Certification, and An internal audit program. 1.2.2 Environmental

The environment in which an examiner must work can have an impact on the accuracy of examinations, particularly inadvertent examiner errors. If the examiner becomes distracted with concerns for personal safety, examination accuracy will decrease. Examples of unsatisfactory environments are: Confined spaces, High temperatures, Heights, and Radiation areas.

The types and amounts of protective clothing required affect the examiners attention. Working in full protective clothing, including supplied air, is a high stress and high fatigue environment.

The effects of the environment on the

examiner and human attention cannot be completely eliminated; therefore, the preferred solution is to reduce dependence on the examiner in these environments. The unsatisfactory



environmental condition should be engineered, or remote examination techniques should be employed. This is the joint responsibility of management, engineering, and examination personnel.

Nondestructive Examination (NDE) Technology and Codes Student Manual

Volume 1

Chapter 2.0

Personnel Qualification and Certification


USNRC Technical Training Center Rev 0409 2i

TABLE OF CONTENTS 2.0 PERSONNEL QUALIFICATION AND CERTIFICATION ...................................................... 1 Learning Objectives

2.1 Qualification vs. Certification .......................................................................................... 1

2.2 Employer-Based Certification vs. Centralized Certification ............................................ 1

2.3 Employer-Based Certification .......................................................................................... 2

2.3.1 SNT-TC-1A .................................................................................................... 2 2.3.1.1 Benefits of SNT-TC-1A ..................................................................... 3 2.3.1.2 Limitations of SNT-TC-1A ................................................................ 4 2.3.1.3 Terminology ....................................................................................... 6

2.3.2 ASNT Certification Standard (ANSI/ASNT CP-189) .................................... 6

2.3.3 Qualification of Personnel for Visual Examination ....................................... 8

2.3.4 Qualification Requirements for Ultrasonic Examination Personnel .............. 9

2.4 ISO 9712 Central Certification ......................................................................................... 9

2.4.1 Term of Certification .................................................................................... 10

2.4.2 Renewal .................................................................................................... 11

2.4.3 Recertification .............................................................................................. 11

2.5 ASNT Central Certification Program (ACCP) ............................................................... 11

2.6 AWS Certification of Welding Inspectors (CWI) .......................................................... 11

2.7 Supplemental Qualification Requirements ..................................................................... 12

LIST OF TABLES


USNRC Technical Training Center Rev 0409 2ii

2-1 Training Hours ............................................................................................................................... 13 2-2 Recommended Experience Time ...15

NDE Technology and Codes Chapter 2.0 Student Manual Personnel Qualification and Certification


2.0 PERSONNEL QUALIFICATION AND CERTIFICATION

Learning Objectives: To enable the student to: 1. Understand the differences between central-

ized certification and employer-based certifi-cation.

2. Understand the requirements of various NDE

certification programs, including common U.S. based systems and international systems.

3. Identify the salient features of the Nuclear

Power Industry Performance Demonstration Initiative.

2.1 Qualification vs. Certification

NDE is a discipline that requires formal training and on-the-job experience to develop an individual that is capable of properly performing the examination and obtaining meaningful results. Users of NDE services need assurance that the individual performing NDE has the qualifications necessary to detect the conditions of interest in a predictable, consistent manner.

The certification system has been adopted by industry to provide that assurance. Certification is not to be confused with qualification. Qualification is the ability of an individual resulting from education, training, and experience to perform an NDE correctly. Certification is written testimony that the individual has the proper

qualifications and meets some minimum standard of education, training, and experience.

A number of certification systems have been developed for use by U.S. industries. The Amer-ican Society for Nondestructive Testing (ASNT) has developed several systems for the certification of NDE personnel. The American Welding Society has also developed a system of cert

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