inspection and monitoring of pipe wall thinning and ruptureinspection and monitoring of pipe wall...

Pusan National University Quality Engineering & Failure Prevention Lab마스터 부제목 스타일 편집

Joon-Hyun Lee

Inspection and Monitoring of

Pipe Wall Thinning and Rupture

Director, Basic Atomic Energy Research Institute School of Mechanical EngineeringPusan National University ,Busan 609-735, Korea

IAEA Workshop on Detection, research, management and monitoring of ageing factors,Buenos Aires, Argentina, 9-12 December 2008

Basic Atomic Energy Research Institute

Pusan National University Quality Engineering & Failure Prevention Lab

Contents

1. Thinned Pipe Management Programme(AMP-11 Flow Accelerated Corrosion)

2. Activities on Dissimilar Metal Weld

3. Development of Mechanical Analysis and Crack Management Technology for DMW

4. Development of Performance Demonstration System for DMW

5. Inspection & Monitoring Technology of Pipe Wall Thinning

6. Evaluation of Statistical Reliability on Ultrasonic Thickness

Measurement Results by Round Robin Test

7. Research Activities of Inspection & Repair Technique Review in Japan


Thinned Pipe Management Program

(AMP-11 Flow Accelerated Corrosion)

3

Pusan National University Quality Engineering & Failure Prevention Lab4

Mihama-3 Accident (2004.8.9)- Pipe rupture due to wall thinning- 5 men killed, 6 injured- Shutdown for 29 months(restarted on Jan. 11, 2007)

- Big loss in human and money- Importance of FAC popped up

Importance of FAC


Overview of TPMP


NSAC-202L-R3(2006.05)

’’96.0896.08--’’99.0899.08 ’’00.0400.04--’’03.0303.03 ’’04.1204.12--’’07.1207.12 ’’09.0409.04--’’11.1211.12Introduction ofNSAC-202L & CHECWORKS

Development ofstandard procedure(TPMP)

Optimization of technical activitieson TPMP

Preparations fornew plants, power uprating

Plant FAC Model• KR3,4 Plant FAC Model

• KR1,2• WS1,2,3,4• YG1,2,3,4• UC1,2,3,4

Plant FAC Model•YG5,6 & UC5,6

Plant FAC Model• SKR1,2 & SWS1,2

PSI (Baseline Data)• YG5,6 & UC5,6

Convert to SFA,DB Expansion, SSE• KR1,2,3,4• WS1,2,3,4• YG1,2,3,4• UC1,2,3,4

PSI (Baseline Data)• SKR1,2 & SWS1,2• 1,000 components• Jacket type insulation

UT Inspection• Partial ⇒ FullSelect Location• Engineering Judgment⇒ Model Analysis

NSAC-202L-R1(1996.11)

NSAC-202L-R2(1999.04)

TR-1011231(2004.11)

WANO SER 2006-1

(2006.09)

INPO EPG(2006.12)

•Criteria for UTCriteria for UTCriteria for UTCriteria for UTthickness measurethickness measurethickness measurethickness measure(Round Robin Test)(Round Robin Test)(Round Robin Test)(Round Robin Test)

•Alternative criteriaAlternative criteriaAlternative criteriaAlternative criteriato ASME CC Nto ASME CC Nto ASME CC Nto ASME CC N----597597597597(Experiment & FEA)(Experiment & FEA)(Experiment & FEA)(Experiment & FEA)

EngineeringEngineeringEngineeringEngineeringevaluation evaluation evaluation evaluation EqsEqsEqsEqs....(FEM & Experiment)(FEM & Experiment)(FEM & Experiment)(FEM & Experiment)

History of TPMP


Scope of TPMP


Assess Plant Wear Level

Inspection(Thickness Measure)

Evaluate Wear and Remaining Life

Determine Following Action

Select Componentwhere Inspection

Needed

Thickness Criteria (tcrit)

Minimizing UT Reading Inaccuracy

Including all Steam Cycle Piping SystemFAC + Erosion (Cavitation/Flashing/LIE)

Establishing Predictive Plant Model

CC-N597 / Next Insp. Period

Chexal-Horowitz FAC Model

8

Engineering Activities of TPMP


Web-Based Management System


• Results : Ratio of Safety Margin– Applicable Moment / Design Moment– Burst Pressure / Design Pressure– Predicted Local Thickness / Allowable Local Thickness

• Applicable to Non-Safety Piping(96% of Secondary System)• Independent Software, engineer can use easily

10

Pipe Thinning Evaluation Program


Alternative Local Wall-Thinning Assessment Criteria

- Provide criteria for structural integrity of pipe- Find locations susceptible to FAC- Minimize the possibility of unexpected pipe failure

Integrated approach onThinned Pipe Management

PredictivePlant

Model &Trend

Tracking

Criteria for the Ultrasonic Thickness

MeasurementBurst Test with Pressure

Failure Test with

Pr. & Bending

Analytical Approach(Elastic -

Plastic, TES)

Effects of TPMP


Activities on Dissimilar Metal Weld


PWSCC Cases in DMW


Activities on DMW in KEPRI


Development of Mechanical Analysis

and Crack Management Technology for

DMW


Mechanical Analysis for DMW


Evaluation of Residual Stresses (1/2)


Evaluation of Residual Stresses (2/2)


Analysis vs. Measurement


Development of

Performance Demonstration System

for DMW


PD of NDE


PD System for DMW(1/3)


Inspection & Monitoring Technology

of Pipe Wall Thinning


� Possibility of long range inspection� Application for inaccessible site� High sensitivity for defect in comparison

with bulk wave� Safe of inspection time and cost due to

fast speed

� Possibility of long range inspection� Application for inaccessible site� High sensitivity for defect in comparison

with bulk wave� Safe of inspection time and cost due to

fast speed

�Contacting generation and reception of the wave

�Time-consuming�Intensity of the wave is not stable due to the variation of the coupling condition�Limitation of inspection area �Temperature limitations

�Contacting generation and reception of the wave

�Time-consuming�Intensity of the wave is not stable due to the variation of the coupling condition�Limitation of inspection area �Temperature limitations

Conventional Ultrasonic testingConventional Ultrasonic testing NDE technique using guided wavesNDE technique using guided waves

Utilization of Guided Wave Technique


Comparison of Various Techniques Using Guided Wave

PZT PVDF MSsR Air-coupled Transducer

Laser(with slit)

Variables Frequency, angle

Frequency,wavelength

Frequency angle wavelength

Contact or not contact contact Closely non-contact

Non-contact Non-contact

PZT PVDF MSsR Air-coupled Transducer

Laser(with slit)

Variables Frequency, angle

Frequency,wavelength

Frequency angle displacement

Contact or not contact Contact Closely non-contact

Non-contact Non-contact

Mode selectivity Selectable Selectable Selectable Selectable NoneS/N ratio best Good Good good Not good

1. Generators of guided wave

2. Receivers of guided wave (frequency < 5MHz)


Long range inspectionLong range inspection

Local inspectionLocal inspection

comb transducer

� Conventional technique using guided waves→→→→ Long range inspection� Ultrasonic testing using laser →→→→ Defect sizing by local inspection in spot

where defect is apt to generate

defect

NDE using Laser Generated Ultrasound

Metal corrosion


Generation of Guided Wave Comb Transducer

Fully contact with cylinderical shape

Generation of axisymmetric guided wave

Mode selectivity of guided wave

Contact method using Comb Transducer

Longitudinal wave

Transverse wave

L wave Incidence


� High power tone burst system

� Transmitter : Comb transducer

� Receiver : Variable angle transducer

Comb transducer- λλλλ = 12mm- Frequency : 1.5Mhz

Com b transducer

λλλλλλλλ

SpecimenSpecimenSpecimenSpecimen Outer DiameterOuter DiameterOuter DiameterOuter Diameter(mm)(mm)(mm)(mm)

Inner DiameterInner DiameterInner DiameterInner Diameter(mm)(mm)(mm)(mm)

Stainless SteelStainless SteelStainless SteelStainless Steel(SUS 304)(SUS 304)(SUS 304)(SUS 304) 114114114114 110110110110

Dimensions of sample tubeDimensions of sample tubeDimensions of sample tubeDimensions of sample tube



2. Artificial wall thinningdepth =0.7mm

L =114mm

Shape of wall thinningShape of wall thinningShape of wall thinningShape of wall thinning

35.0=td

d : depth d : depth d : depth d : depth

t : thicknesst : thicknesst : thicknesst : thickness

Machined Machined PointPoint

1. Mode ConversionOscilloscopeLecroy 9310A

Transmitter Receiver

Pulser/ReceiverRitec RAM-10000

Personal Computer

400 mm 100 mm

guided wave propagationEnd of Pipe



� Linear slit array→ Element width : 4.5mm� Element gap : 2.25mm, Elements : 7� Standoff : 15mm, Propagation distance : 100mm

Laser-Generated Guided wave

Amplifier

Pulse/ Receiver

Oscilloscope

• Wavelength : 532nm• Energy : 32mJ• Pulse rate :1Hz-10Hz• Pulse duration : 7ns

• Bandwidth : 0.04 - 2.25MHz• Aperture : 34mm x 25mmL

Air-coupled Transducer


Carbon steel pipe

Experimental Result (cont.)Signal variation according to varying depth of wall-thinning

Time Domain Time-Frequency Domain

Depth 3.6mm

Depth2.4mm

Depth 1.2mm

DefectFree

DepthLength

6mm

� Length : 48mm� Depth : 1.2, 2.4, 3.6mm� Receiving Angle : 6.4°°°°� Distance between laser - ACT: 90mm

Experimental data


The Schematic of the MsSR 2020 instrumental system

MssR 2020

• Pulse-Echo method

• One sensor can be transmitter and receiver.

• 128kHz torsional dual channel adaptor are used.

Carbon Steel PipeCarbon Steel PipeCarbon Steel PipeCarbon Steel Pipe

Ferromagnetic Strip

Pulse-Echo Method

6.1m Echo SignalTorsional guided waves

Transmitter & Receiver

• T-mode

• Frequency : 128kHz (Dual Channel)

• Direction : (+)

3.5m 0.15m 2.45m

MAGNETOSTRICTION


Monitoring Technology Proposedby PNU, SNU


Overview of New Technology


Principle of ES-DCPD


Principle of Impact Method


Wide Range Monitoring Verification


Narrow Range Monitoring Verification


Impact Method Monitoring Verification


Evaluation of Statistical Reliability on

Ultrasonic Thickness Measurement

Results

by Round Robin Test


Pipeline Management Program

CHECWORKSTM

- software workstation intended to address the corrosion behavior of NPP- data management & corrosion analysis program

• Evaluate UT data obtained during wall thickness inspections• Organize, store, retrieve & management plant data• Evaluate plant water treatment options• Determine FAC wear rate• Identify locations susceptible to FAC• Facilitate outage planning & management

- In Korea, wall-thinning in pipelines has been monitoring on the basis of CHECWORKS program introduced by EPRI since the mid-1990’s


� Investigation of the reliability on Ultrasonic thicknessmeasurement system- Analysis of error factors on Ultrasonic thickness measurement by doing Round Robin test from 4 different experts group using mock-up and field specimens

- Analyze these Data by statistical methods to verify reliability in measurement system

- Derive confidence intervals of local part and inspectorsrespectively

Objective


Gage R&R Analysis (1)

Analysis of errors in measurement system�Measurement system errors divide two part of variations

�Repeatability (A.V.) - variation of repetitive measurementsby an individual inspectorex) measurement position, direction..

�Reproducibility (E.V)- variation of each inspectors in groupex) expertness, condition..Gage R&R method can analyze thesefactors. Measurement system error analysis


Gage R&R analysisE.V. (Equipment Variation ) : Standard deviation of reproducibilE.V. (Equipment Variation ) : Standard deviation of reproducibilityity

n: No. of gridr : No. of repetitionX : data average

d : Duncans coef.R : range average6sigma : 99.73%A.V. (Appraisal Variation) : Standard deviation of reproducibiliA.V. (Appraisal Variation) : Standard deviation of reproducibilityty

( ) ( )22 ....& VEVARGageR +=

Gage R&R Analysis (2)

( ) ( )1*2

6ˆ6.. kRRd

VE ×=

== εσ

*216d

k = 693.1*2 =d

( ) ( ) ( ) ( )nrVEkX

nrVEX

dVA diffdiffo

2

22

22

*2

..)(..6ˆ6.. −=−

== σ


Materials and Experimental Setup (1)

Type Thickness(mm) Flaw Type Thickness

(mm) Flaw

2”

Pipe 3.91 7

8”

Pipe 8.18 7Elbow 3.91 2 Elbow 8.18 2Tee 3.91 3 Tee 8.18 3

Reduce 3.91 2 Reduce 8.18 2

4”

Pipe 6.02 7

12”

Pipe 9.52 7Elbow 6.02 2 Elbow 9.52 2Tee 6.02 3 Tee 9.52 3

Reduce 6.02 2 Reduce - -

6”

Pipe 7.11 7 16” Elbow 12.7 Natural

Elbow 7.11 2 3.5” Elbow 5.49 Natural

Tee 7.11 3 3.5” Tee 5.49 Natural

Reduce 7.11 2 18” Reduce 30.96 Natural

Round-Robin test specimens Pipe : A106 Gr. B Fitting : A234 WPB

Field specimens


8 inch

12 inch

2 inch

4 inch

3.5 inch Tee, Elbow

18 inch Reducer

16 inch Elbow

6 inch

Total grid : 2131 point

Artificial specimens : 19eaField specimens : 4ea

Foreground of round-robin test-loop

Inspector - 12 persons in 3 company(1,2,3,4 group)

Gage - Panametrics 37DL-PLUSCouplant- Sonotech Ultragel ⅡⅡⅡⅡProbe - D790-SM (5MHz) : 11mmD795 (5MHz) :7.1mm

Materials and Experimental Setup (2)

Round Robin Test loop foreground


Experimental method

Round Robin test progress� Measured 3times of 2, 4, 6, 8, 12inch mock-up specimens 19set and field specimens 4set by using 37DL-PLUS gage and D790-SM, D795 probes

� Analyze reliability of normal inspector 3 group and ordinary inspector 1 group � Analyze reliability of pipe sound and local corrosion part� Analyze reliability of elbow Intrados and extrados� Analyze reliability of reducer inlet and outlet

dataTotalgridtimeinspector )716,76(2131312 =××


Diameter(inch)

Pipe( mm)

Elbow( mm)

Tee( mm)

Reducer( mm)

2 0.10 (2.6%) 0.112 (2.8%) 0.19 (3.6%) 0.16 (2.6%)

3.5 - 0.11 (1.9%) 0.15 (2.6%) -4 0.11 (1.8%) 0.09 (1.5%) 0.18 (2.2%) 0.19 (2.4%)6 0.10 (1.4%) 0.16 (2.3%) 0.17 (1.8%) 0.24 (2.9%)8 0.14 (1.5%) 0.17 (2.1%) 0.16 (1.6%) 0.23 (2.2%)12 0.14 (1.5%) 0.13 (1.4%) 0.14 (1.2%) -16 - 0.11 (0.9%) - 0.37 (1.2%)

Gage R&R analysis of ordinary inspectors

Experimental Results (cont.)

(%) : percentage of average thickness

± ± ±±


Diameter(inch)

Pipe( mm)

Elbow( mm)

Tee( mm)

Reducer( mm)

2 0.21 (5.4%) 0.31 (7.9%) 0.31 (5.6%) 0.31 (5.0%)3.5 - 0.37 (6.8%) 0.41 (7.5%) -4 0.17 (2.8%) 0.29 (47%) 0.28 (3.5%) 0.31 (3.9%)6 0.16(2.3%) 0.25 (3.5%) 0.25 (2.7%) 0.24 (2.9%)8 0.16 (1.9%) 0.20 (2.4%) 0.22 (2.1%) 0.20 (2.0%)12 0.17 (1.8%) 0.19 (2.1%) 0.19 (1.6%) -16 - 0.19 (1.5%) - 0.70 (2.3%)

Gage R&R analysis of normal inspectors

(%) : percentage of average thickness

± ± ± ±



0000

0.10.10.10.1

0.20.20.20.2

0.30.30.30.3

PipePipePipePipe ElbowElbowElbowElbow TeeTeeTeeTee ReducerReducerReducerReducer

Gage R&R analysisOrdinaryOrdinaryOrdinaryOrdinary

NormalNormalNormalNormalNormal inspectors error is higher than ordinary inspectorsIncreased rate of errorPipe : 31.6%Elbow : 46.2%Tee : 32.7%Reducer : 43.9%Average : 38.6%skillfulness, calibration, measurement error..



Dia.(inch) Total ( mm) Corrosion( mm) Sound( mm)2 0.10 (2.6%) 0.16 (4.2%) 0.06 (1.4%)4 0.10 (1.8%) 0.12 (1.9%) 0.05 (0.9%)6 0.10 (1.4%) 0.12 (1.8%) 0.09 (1.3%)8 0.14 (1.5%) 0.14 (1.7%) 0.12 (1.5%)12 0.14 (1.5%) 0.16 (1.7%) 0.13 (1.3%)

Average 0.12 (1.8%) 0.14 (2.2%) 0.09 (1.3%)

Corrosion/sound part gage R&R analysis of pipe

Sound part

Corrosion part of FAC shape

± ± ±



0000

0.050.050.050.05

0.10.10.10.1

0.150.150.150.15

0.20.20.20.2

2inch2inch2inch2inch 4inch4inch4inch4inch 6inch6inch6inch6inch 8inch8inch8inch8inch 12inch12inch12inch12inch

Pipe corrosion/sound part analysisPipe corrosion/sound part analysisPipe corrosion/sound part analysisPipe corrosion/sound part analysis

TotalTotalTotalTotal

CorrosionCorrosionCorrosionCorrosion

SoundSoundSoundSound

Local corrosion part shows more higher error.Increased rate of error2inch : 57.3%4inch : 8.3%6inch : 24%8inch : -5.6%12inch : 12.1Average : 19.2%



Intrados / Extrados Gage R&R analysis of elbowDia. (inch) Total ( mm) Intrados ( mm) Extrados ( mm)

2 0.11 (2.8%) 0.13 (3.2%) 0.14 (3.7%)4 0.09 (1.5%) 0.16 (1.4%) 0.11 (1.8%)6 0.16 (2.3%) 0.26 (3.7%) 0.21 (2.9%)8 0.17 (2.1%) 0.27 (2.8%) 0.21 (2.5%)12 0.13 (1.4%) 0.11 (1.2%) 0.17 (1.8%)

Average 0.13 (1.8%) 0.15 (2.2%) 0.14 (2.1%)

Extrados

Intrados

± ± ±



0000

0.050.050.050.05

0.10.10.10.1

0.150.150.150.15

0.20.20.20.2

0.250.250.250.25

0.30.30.30.3

2inch2inch2inch2inch 4inch4inch4inch4inch 6inch6inch6inch6inch 8inch8inch8inch8inch 12inch12inch12inch12inch

Elbow Intrados/Extrados analysisElbow Intrados/Extrados analysisElbow Intrados/Extrados analysisElbow Intrados/Extrados analysis

TotalTotalTotalTotal

IntradosIntradosIntradosIntrados

ExtradosExtradosExtradosExtrados

Intrados/Extrados shows more higher errorIncreased rate of maximum error2inch : 28.6%4inch : 72.8%6inch : 61.1%8inch : 55.0%12inch : 27.3Average : 49%



Local part gage R&R analysis of reducerDia. (inch) Inlet ( mm) Middle ( mm) Outlet ( mm)

2 0.18 (3.4%) 0.17 (2.7%) 0.15 (2.1%)4 0.08 (1.1%) 0.16 (2.0%) 0.09 (1.0%)6 0.13 (1.7%) 0.37 (3.9%) 0.11 (1.1%)8 0.25 (2.7%) 0.21 (2.1%) 0.13 (1.2%)

Average 0.16 (2.2%) 0.21 (2.7%) 0.12 (1.4%)

OutletMiddleInlet

± ± ±



0000

0.050.050.050.05

0.10.10.10.1

0.150.150.150.15

0.20.20.20.2

0.250.250.250.25

0.30.30.30.3

0.350.350.350.35

2inch2inch2inch2inch 4inch4inch4inch4inch 6inch6inch6inch6inch 8inch8inch8inch8inch

Reducer local part analaysisReducer local part analaysisReducer local part analaysisReducer local part analaysis

InletInletInletInlet

MiddleMiddleMiddleMiddle

OutletOutletOutletOutlet

Middle part shows more higher errorsIncreased rate of maximum error2inch : 10.5%4inch : 30.6%6inch : 29.5%8inch : 11.6%Average : 20.6%



Conclusion

� Round Robin Test was conducted for mock-up specimen by 4 groups inspectors from 3 inspection companies.� Precision analysis of test results is obtained using gage R&R method. � Compared skillfulness of ordinary inspectors and normal inspectors� Confidence intervals deviation of corrosion/sound part is 19% in pipe� Confidence intervals deviation of geometrical local part is 49% in elbow

and 21% in reducerVerified confidence intervals of Ultrasonic thickness measurement system.It can be will improve the integrity of CHECWORKS program.


Research Activities of Inspection &

Repair Technique Review in Japan


KoriKori SiteSite ViewView--PWRPWR

Coordination with other Review (FY2007)


Activities for Inspection of SCC & Repair Welding


Research Achievements in FY2007Detection & Monitoring of

Pipe Wall Thinning(a)DC potential drop method(b)EMAT & EC dual probe(c)EMAT(d)Remote field eddy current method(e)Guided waves with reflector(f) Microwave method


(a) Evaluation and imaging of SCC around welds by UT

(b) SCC depth sizing by 3D-SAFT UT method

Research Achievements in FY2007Sizing & Monitoring of SCC


Remarks on the Workshop


Summary

� Overview of Inspection & Repair Technique Review

� Research Achievements in FY2007• Applicability Evaluation of New Technologies• Detection & Monitoring of Pipe Wall Thinning• Sizing & Monitoring of SCC• Integrity of Repair Welding & Reliability of Repaired Welds

� The First Japan-Korea Joint Workshop

inspection and monitoring of pipe wall thinning and ruptureinspection and monitoring of pipe wall...

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