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Status of advanced UT systems for the nuclear industry
Nuclear Engineering and Design 102 (1987) 265-273 North-Holland, Amsterdam
265
STATUS OF ADVANCED UT SYSTEMS FOR THE NUCLEAR INDUSTRY M. B E H R A V E S H , M. A V I O L I , G. D A U a n d S.-N. L I U Electric Power Research Institute, P.O. Box, 10412, Palo Alto, CA 94303, USA
Received December 1986 Ultrasonic NDE technology has advanced a great deal within the last two years. Advances have been so rapid that it is often difficult for a utility NDE manager to keep informed of all of the available inspection systems and their capabilities. The terms and concepts used by the developers and manufacturers of the equipment may leave the end user in a state of apprehension when a problem appropriate to an advanced system arises. EPRI is supporting efforts whose goals are to aid the utility NDE manager by providing him with a guide for selection and use of advanced systems and workshops to disseminate the latest information.
1. Introduction An advanced ultrasonic testing (UT) system is a configuration of hardware that includes some type of computer. The computer may be hardwired to perform specific functions or have appropriate software. It may typically be used for data acquisition, signal processing, image generation, pattern recognition and data analysis. Additionally, advanced systems have data storage and are, therefore, different from the standard transducerpulser/receiver systems that rely on human filtering and written documentation of the filtered data. See fig. 1. More and more utilities and service vendors are using or are considering an advanced UT system for preservice (PSI) and inservice (ISI) inspections. A major utility has purchased five Amdata's IntraSpect Ultrasonic Imaging systems. Another has bought and is using a NES/Dynacon's UDRPS system. Science Application Inc's Ultra Image III, along with lnfometric's TestPro software, is being used for turbine rotor bore inspection. lntraSpect imaging technology is being combined with pattern recognition capabilities by a leading service vendor. Fig. 2 shows typical hardware configurations. New and potential users of advanced UT systems are increasing in numbers every day. What these systems offer is so attractive that regulatory agencies consider their deployment an "intelligent choice" for inspection.
2. Background
is the radiation background that is present and increases with years of service. Inspection personnel must always consider the ALARA guidelines (As Low As Reasonably Achievable) for radiation. The human factors include biological hazard and psychological stress. Under these pressures, the data processing capabilities of the human brain are also limited. This is why UT inspection data, when collected manually, is usually in summary form. On the economic side, inspection costs are tied directly to the radiation dose rate at the inspection site. Allowable radiation dose per quarter is regulated and oftentimes results in shortages of qualified personnel to perform UT ISI in nuclear plants. This has economic impact via the deployment of limited personnel to do a job that has not changed in size or scope. The longer the down time, the higher the cost of purchasing replacement power to counter the loss of generating capacity. Advanced systems were developed with the goals of reduced radiation exposure and increased reliability. These systems use scanners for highdensity coverage of components, and since some of them are mechanized and remotely controllable, radiation exposures to personnel can greatly be reduced. Fig. 3 shows the AMAPS in a mechanized scanner developed by EPRI. Digital recording and processing data facilitate repetition of stored scan patterns, data logging for data review, and application of signal processing techniques for noise reduction.
The most significant difference between nuclear power plant UT inspection and, say, aircraft inspection, 0 0 2 9 - 5 4 9 3 / 8 7 / $ 0 3 . 5 0 © Elsevier Science Publishers B.V. ( N o r t h - H o l l a n d Physics Publishing Division)
266
M. Behrauesh et al. / Status of aduanced UT.wstems
TRANSDUCER
i
RECEIVER
Fig. la. Standard UT inspection - Hardware configuration.
TRANSDUCER(S)
:
1
SC,NNER ! ¸11/%!¸¸¸¸!¸¸! i I
/ RECEI VER
,
ENHANCED SIGNALS
Fig. 2a. Imaging system packaged for field deployment.
CONTROLLER
COMPUTER
I J
Jl t
IMAGES
FEATURES INFERENCES
Fig. lb. Advanced UT inspection - System configuration.
3. Advanced systems T h e n u m b e r of systems becoming commercially available is growing each year. The N D E managers of utilities, the end users of these systems, are often faced with the decision as to " W h a t system is right for my inspection problem?". " I s an advanced U T system a cost effective way to go?". To help this group, the Electric Power Research Institute (EPRI) has initiated a project whose end product will b e a Utility N D E Managers' G u i d e to A d v a n c e d U T Systems. A short
Fig. 2b. Imaging system in off line mode.
s u m m a r y of the available data to date will be presented here. Tables are used to give an immediate overview of capabilities. There are two b r o a d classifications of advanced U T systems. These are feature-based systems and imagebased systems. A feature-based system is very similar in concept to a radar system for aircraft. Parameters, or " f e a t u r e s " are extracted from the ultrasonic signals
267
M. Behravesh et al. / Status of advanced UT systems
accumulated during a n inspection. These features are believed to c o n t a i n i n f o r m a t i o n a b o u t the reflector the p r o d u c e d the original ultrasonic echo. As in radar,
processing of echo features can be used to identify the reflector. Fig. 4 illustrates this concept. Imaging systems use arrays of ultrasonic signals o b t a i n e d from surface
Table 1 Commercially available automated UT systems/services - Hardware Intraspect 98
P-Scan
SOL-1000
SMART UT
UDRPS
Ultra Image 111
Zip-scan
V e n d o r - Service group:
Amdata Inc./CE
Independent Testing Labs. & Universal Testing Labs. Inc.
Sigma Research Inc.
General Electric Company
NES/Dynacon Systems Inc.
Ultra Image International
U.S.Testing Company Inc.
Automated scanner
AMAPS
AWS-4
SOL-1003
ALARA-1 or AMAPS
ALARA-1, AMAPS or VERSASCAN
ALARA-1 or AMAPS
MIMIC
MWS-2
SOL-1004
General Dynamics
VERSASCAN
Ultra Image std. minature
Rigid track flex-steel & mag. wheels or plastic belt
Rigid track or flex-steel & mag. wheels
Semi-automated scanner Guide track & mounting
Felx-steel with mag. wheels
Steel track with timing belt
Flex-steel with lock-on carpiage
Rigid track or flex-steel & mag. wheels
Scanner controller
Computer interfaced &joystick
Computer interfaced
Computer interfaced
Controller W / Computer auto or manual interfaced or computer &joystick interfaced
Transducer
Contact or booted
Contact
Contact & Contact immersion or booted
Contact, booted or mult. (6) array
Contact or booted
Contact
UTcomponents
Metrotek
P-Scan
SDL-1000
Ultra image III
Any commercial unit
Ultra Image III
Zipscan
Data storage
Hard disk & floppy & cassette
Magnetic tape cassette
Hard disk & floppy
Hard disk Hard disk. 9-track or & floppy & VHS of A-Scan optical disk or RF
Hard disk & floppy
Hard disk & floppy
Data display
RGB color CRT
B/w CRT
RGB color & B/W CRT
RGB color & B / W CRT
Ramtek color CRT
RGB Color & B / W CRT
B/W CRT
a/w &
VHS & color polaroid
Ramtek Versatec & techtronix color
Techtronix 4632/4634 & matrix color polaroid
3M VRG 40OO
Ultra image III
HP-1000 & AP 400 array processor
Ultra Image III Z-80 80286/8087 Z-80 80286/8087
LSI-11/73
Hardcopy unit
Computer - data processing
(2 EA.)
Techtronix & color polaroid
EPSON FX 80
HP 9836C
P-Scan processor
color polaroid SDL-1001
Flex-chain & non-metallic wheels
Controller W / Computer auto or manual interfaced or computer interfaced
268
M. Behrat, esh et al. / Status of adt,anced UT systems
scanning to create "pictures" of reflectors located within a material. The purpose of the images is to assist an inspector in obtaining information on the spatial char-
acteristics of his inspection problem. EPRI is currently examining systems that combine feature-based and image-based capabilities into, as they
Table 2 Commercially available automated UT systems/services - Software
Vendor group:
Service
Scan motion Acial Circumferential Skew
Data recording Amplitude Position Arrival time
RF waveform Rectified waveform Instrument settings
Intraspect 98
P-Scan
SDL-1000
SMART UT
UDRPS
Ultra Image II1
ZIP-Scan
Amdata Inc./CE
Independent Testing Lab & Universal Testing Lab
Sigma Research Inc.
General Electric Company
NES/Dynacon Systems Inc.
Ultra Image lnternatl
U.S.Testing Company Inc.
mmm mmm mmm
mmm mmm mmm
mmm mmm mmm
mmm mmm
mmm mmm
mmm mmm
mum mmm
mum
mmm
mmm
mmm
mmm mmm
mmm mmm
mmm mmm
mmu mmm
mmm mum
mmm mmm
mmm mmm
mmm mmm
mmm
mmm
mmm mmm
mmm mmm mmm mmm
mmm
mm• mmm mmm
mmm
mmm • mmm mmm
mmm mmm mmm mmm
mmm
mmm mmm mum mmm mmm mmm mmm mmm mmm
mmm mmm mmm
mmm mmm mmm
mmm
Data display A-Scan B-Scan C-scan 3-D Isometric
mmu mmm mmm •
Projected views Time-of-flight Flaw map
mum
mum
mmm
mmm mmm
mnm
mmm
Zoom
Dac curves Averaging Temporal averaging Spatial averaging Synthetic apeture Holography SAFT A rtificial intelligence ALW Feature extraction Pattern recognition Sitting techniques Tandem technique Mode conversion techniq Creeping wave Crack tip diffraction mmm fulll capability
•
partial capability
mmm mmm mmm
mmm
mmm
•
mmm mmm
mmm
mmm mmm
•
mmm •
•
mnm
•
mmm
mmm
mmm
mmm mum mum
mmm mum
mmm mmm mmm
mmm mmm
M. Behravesh et al. / Status of advanced UT systems
269
Fig. 3. The AMAPS mechanized scanner. Table 3 Commercially available components supporting automated UT systems System
Manufacturer
Function/Description
ALARA-1
Virginia Corp.
An automated mechanical scanner and scanner controller that can be interfaced to a computer. Mechanical system provides skew motion as well as standard scan motion. Rigid track and guide assembly.
ALN
Adaptronics/ Gen. Res. Corp.
Adaptive Learning Network (ALN) allows training of the system to distinguish key features of the U T signal unique to specific defects or conditions and assists the inspector in confirming defect or geometry conditions.
AMAPS
Amdata systems inc.
An automated mechanical scanner and scanner controller that can be interfaced to a computer. Configured for hard shoe or booted transducer assembly. Flex-steel, wrap around track with magnetic wheels.
ROBBI
Kraftwerk Union
An automated U T inspection system designed primarily for flaw sizing and not significantly used for initial inspection and detection. System is presently being reconfigured for full inspection use.
SDL-1000
Sigma Research Inc.
An automated U T inspection system capable of A, B, C and 3D scan imaging but principally designed for ultrasonic holography inspection and high resolution imaging of previously detected indications.
SUTARS
Southwest Research Institute
An ultrasonic tracking system used with manual U T to integrate scan position with UT data. Tracking sensors strap to pipe to provide position data for hand held transducer.
TEST PRO
Informetrics Inc.
IBM PC based hardware and software allows integration of all automated U T components and assories to provide fully automated U T system. PC is a value-added component to current automated U T systems. RF waveforms are recorded: artificial intelligence and pattern recognition algorithms are built into the software. Provides additional analysis capability using standard PC software such as Lotus 1-2-3.
270
M. Behral;esh et al.
/ Status qf adt, anced UT ~vstems
~quisition
R-F W A V E F O R M
Signal processing
/ /L ENVELOPE
peak Feature
extraction
ItT Pattern
recognition r Y = W 0 + W 1 • RT + W 2 • PD + W 3 " FT IF Y > T
Class 1
IF Y < T
Class
(crack)
2 (root)
Fig+ 4. Feature-based U T analysis concepts.
M. Behravesh et al. / Status of aduanced UT systems
271
Table 4 Not yet commercial automated UT systems and technologies System
Developers
Function/Description
ALOK
IzFP & Kraft Werk Union
Amplitude detection with time-of-flight signatures are used to detect flaw conditions. System uses standard UT transducers but is being upgraded to incorporate phased array transducer and will be capable of ALOK, ultrasonic holography and line SAFT imaging.
CUDAPS
EPRI & Adaptronics Gen. Res. Corp.
Computerized Ultrasonic Data Acquisition & Processing System (CUDAPS) incorporates ALN systems to provide a complete automatic UT system. Major components are ALN-4060 Flaw Discriminator, LSI-11 Microprocessor and AMAPS scanner controlled by an ALN-4033 Scan Controller. System has been configured at the EPRI NDE Center.
PVIS
EPRI & Sigma Research Inc.
Pressure Vessel Imaging System (PVIS) is an ultrasonic holography inspection system for heavy section steel inspection. The system can perform A, B, C, 3D and holographic imaging and integrate multiple images into final 3D images. System under evaluation at NDE Center.
SAFT
NRC, BattelleNorthwest & CE
Synthethic Aperture Focused Technique (SAFT) is a UT technology which provides focused UT images in the complete inspection volume. A transducer or point UT source is scanned over the volume surface and resulting UT data is analyzed to provide very high resolution focused UT image data at all points in the inspection volume.
Sector Scan
EPR1 & Vintek, Inc.
Real-time sector scan UT imaging uses a phased array or mechanically scanned transducer to provide real-time L and S wave images in a sector B-scan mode. Technology is similar to commonly used medical real-time sector scan units.
are conceived, feature-enhanced imaging systems. Considerations are being given to the use of Personal C o m puters (PC's) for the h a r d w a r e and software needs of these systems. Tables 1 a n d 2 cover systems that are in use today. T a b l e 1 lists the hardware that comprises these systems. The software and software function capability of these systems are listed in table 2. The systems m e n t i o n e d are not restricted to tables 1 and 2 hardware a n d software. T a b l e 3 describes commercially available c o m p o n e n t s that m a y be used as alternatives a n d / o r e n h a n c e m e n t s . Several U T systems that are still u n d e r d e v e l o p m e n t are listed in table 4.
4.
A major concern of the utility N D E m a n a g e r is the compliance of the system he chooses with N R C guidelines. The U S N R C has issued guidelines that define m i n i m u m acceptable performance requirements. Qualification tests have been developed to evaluate advanced U T systems against the established criteria defined by the N R C . Systems that have met all of the U S N R C requirements for I G S C C detection a n d sizing are listed in table 5.
5.
Table 5 Advanced systems satisfying IGSCC demonstration requirements System
Detection
Sizing
ALARA 1 ANL 4060 CUDAPS Intraspect P-Scan Sutars Robie Ultra Image III UDRPS Zipscan
x x x × x x
x
x x x
x x x × x
Qualification
Cost-effectiveness
A n o t h e r concern of the utility N D E m a n a g e r is the cost-effectiveness of inspections with advanced systems. Benefits most frequently cited by experienced utility users, service groups, a n d vendors are: - Better, a n d more complete coverage Traceable results - P e r m a n e n t recording Real-time results - Fewer o v e r / u n d e r calls D a t a comparison Post r e v i e w / a n a l y s i s Better reliability - Low-radiation exposure
70 95
140 140 40 550
4. Average M U T inspection speed: (weld i n c h e s / 1 0 h shift)
5. Average A U T inspection speed: (weld i n c h e s / 1 0 h shift)
6. Average number of welds inspected per outage
7. Average number of weld inches inspected per m a n per outage
These are for DOE work and may not be representative. Utility response - 3 out of 16 with 1 N.A. Vendor response - 9 out of 13 with 4 N.A. Total response - 41% Effective response 24%
Effective A U T / M U T cost ratio (item lb divided by item 9).
9. A U T / M U T benifits ratio
8. Benifits
1.00
3.00
3. Estimated A U T / M U T cost ratio
2.00 0.48
4.00 0.75
500
100
1.25
2.00
500
75
400
200
2.50
83 17 120 6000 20.83 5 5 20 " 150" 83.00 ~
7 93 40 1500 9 5 4 150 1,000 ?
90 10 25 1750 28.00 10 10 250 1,600 8.00
2. In your recent experience for an average UT inspection, what is the: (a) % A U T Inspection (b) % M U T Inspection (c) Total number of welds inspected (d) Total number of weld inches inspected (e) Estimated cost to the utility per weld inch (f) Average % repeat inspection including sizing (g) Average % sizing (h) Average radiation level at weld size ( m R / h ) (i) Average inspector (Level 1/ll) exposure per outage (j) Average cost per m R for total outage
3
35000 2.50
2
?
?
?
60
240
240
1.10
50 50 100 5000 50.00 10 7.5 50 600 ?
10000 1.00
4
Utility, Vandor or Service Group 1
1. Type of automated U T system. (GEDAS. Intraspect, P-Scan, U D R P S & G E S M A R T UT) 9000 1500 (a) Approximate inches of weld inspected (b) Estimated cost compared to equivalent manual U T inspection ( M U T ) 3.00 0.90
Table 6 A U T / M U T cost questionnaire summary 7 / 1 0 / 8 6
1.73
1.10
?
300
?
300
1.90
0 100 200 7500 '~ 1 1 30 1,200 ?
500 1.90
5
0.40
5.00
160
130
140
80
2.00
90 10 130 8380 61.00 20 2 500 1,200 9.23
67000 2.00
6
1.25
2.00
102
,)
q
2.50
,)
9
o
,)
9
q
9
q
,)
7190 2.50
7
0.56
3.82
302
222
132
2.15
83 17 116 6855 46.02 14 4 415 1,169 9.08
130190 2.14
Weighted average &totals
r,.--
I-J
314. Behraoesh et al. / Status of aduanced UT systems
Immediate sizing Documented data - Potentially lower cost. Many of the above benefits have significant long-term cost payoffs that are only realizable over a long time and are not immediately measurable. Each advanced system has different features and components which its marketing literature vigorously promotes. It is not always easy to identify the components or feature most important to a particular utility need. If a significant repair cost can be avoided because of the use of a U T system with advanced data display capabilities, it makes little difference if the system also possesses advanced pattern recognition capabilities. Both capabilities are equally important, but certainly not needed by all utility end users a n d / o r applications. To obtain cost information on a u t o m a t e d / a d v a n c e d U T inspection, a survey of the utilities, vendors, and service groups who have used such systems was conducted. Table 6 summarizes the findings of this survey. A total of 29 utilities and inspection service groups were surveyed. Twelve groups or 41% responded; how-
-
273
ever, several had no relevant data which gave an effective response of 21%. Those responding represent a total of more than 120000 inches of welds that have been inspected by advanced U T - about 1900 equivalent 20-inch diameter pipe welds. The data includes G E D A S , IntraSpect, P-Scan, and U D R P S inspection results. Recognizing that inspections with advanced U T systems provide benefits not readily available with manual UT, the initial equipment cost must be scaled accordingly to obtained the effective inspection cost. Specifically, to obtain the effective cost ratio of advanced U T to manual U T inspection ( A U T / M U T ) , the initial A U T / M U T cost ratio must be divided by the benefit ratio. The average initial A U T / M U T cost ratio was 2.12 - advanced U T inspection initially cost 2.12 times more than equivalent manual U T inspection; the average advanced U T to manual U T benefit ratio was 3.93. Therefore, the average effective A U T / M U T cost ratio is 0.64 and hence the effective cost of advanced U T inspection comes out to be less than two-thirds of the cost of equivalent manual U T inspection.
265
STATUS OF ADVANCED UT SYSTEMS FOR THE NUCLEAR INDUSTRY M. B E H R A V E S H , M. A V I O L I , G. D A U a n d S.-N. L I U Electric Power Research Institute, P.O. Box, 10412, Palo Alto, CA 94303, USA
Received December 1986 Ultrasonic NDE technology has advanced a great deal within the last two years. Advances have been so rapid that it is often difficult for a utility NDE manager to keep informed of all of the available inspection systems and their capabilities. The terms and concepts used by the developers and manufacturers of the equipment may leave the end user in a state of apprehension when a problem appropriate to an advanced system arises. EPRI is supporting efforts whose goals are to aid the utility NDE manager by providing him with a guide for selection and use of advanced systems and workshops to disseminate the latest information.
1. Introduction An advanced ultrasonic testing (UT) system is a configuration of hardware that includes some type of computer. The computer may be hardwired to perform specific functions or have appropriate software. It may typically be used for data acquisition, signal processing, image generation, pattern recognition and data analysis. Additionally, advanced systems have data storage and are, therefore, different from the standard transducerpulser/receiver systems that rely on human filtering and written documentation of the filtered data. See fig. 1. More and more utilities and service vendors are using or are considering an advanced UT system for preservice (PSI) and inservice (ISI) inspections. A major utility has purchased five Amdata's IntraSpect Ultrasonic Imaging systems. Another has bought and is using a NES/Dynacon's UDRPS system. Science Application Inc's Ultra Image III, along with lnfometric's TestPro software, is being used for turbine rotor bore inspection. lntraSpect imaging technology is being combined with pattern recognition capabilities by a leading service vendor. Fig. 2 shows typical hardware configurations. New and potential users of advanced UT systems are increasing in numbers every day. What these systems offer is so attractive that regulatory agencies consider their deployment an "intelligent choice" for inspection.
2. Background
is the radiation background that is present and increases with years of service. Inspection personnel must always consider the ALARA guidelines (As Low As Reasonably Achievable) for radiation. The human factors include biological hazard and psychological stress. Under these pressures, the data processing capabilities of the human brain are also limited. This is why UT inspection data, when collected manually, is usually in summary form. On the economic side, inspection costs are tied directly to the radiation dose rate at the inspection site. Allowable radiation dose per quarter is regulated and oftentimes results in shortages of qualified personnel to perform UT ISI in nuclear plants. This has economic impact via the deployment of limited personnel to do a job that has not changed in size or scope. The longer the down time, the higher the cost of purchasing replacement power to counter the loss of generating capacity. Advanced systems were developed with the goals of reduced radiation exposure and increased reliability. These systems use scanners for highdensity coverage of components, and since some of them are mechanized and remotely controllable, radiation exposures to personnel can greatly be reduced. Fig. 3 shows the AMAPS in a mechanized scanner developed by EPRI. Digital recording and processing data facilitate repetition of stored scan patterns, data logging for data review, and application of signal processing techniques for noise reduction.
The most significant difference between nuclear power plant UT inspection and, say, aircraft inspection, 0 0 2 9 - 5 4 9 3 / 8 7 / $ 0 3 . 5 0 © Elsevier Science Publishers B.V. ( N o r t h - H o l l a n d Physics Publishing Division)
266
M. Behrauesh et al. / Status of aduanced UT.wstems
TRANSDUCER
i
RECEIVER
Fig. la. Standard UT inspection - Hardware configuration.
TRANSDUCER(S)
:
1
SC,NNER ! ¸11/%!¸¸¸¸!¸¸! i I
/ RECEI VER
,
ENHANCED SIGNALS
Fig. 2a. Imaging system packaged for field deployment.
CONTROLLER
COMPUTER
I J
Jl t
IMAGES
FEATURES INFERENCES
Fig. lb. Advanced UT inspection - System configuration.
3. Advanced systems T h e n u m b e r of systems becoming commercially available is growing each year. The N D E managers of utilities, the end users of these systems, are often faced with the decision as to " W h a t system is right for my inspection problem?". " I s an advanced U T system a cost effective way to go?". To help this group, the Electric Power Research Institute (EPRI) has initiated a project whose end product will b e a Utility N D E Managers' G u i d e to A d v a n c e d U T Systems. A short
Fig. 2b. Imaging system in off line mode.
s u m m a r y of the available data to date will be presented here. Tables are used to give an immediate overview of capabilities. There are two b r o a d classifications of advanced U T systems. These are feature-based systems and imagebased systems. A feature-based system is very similar in concept to a radar system for aircraft. Parameters, or " f e a t u r e s " are extracted from the ultrasonic signals
267
M. Behravesh et al. / Status of advanced UT systems
accumulated during a n inspection. These features are believed to c o n t a i n i n f o r m a t i o n a b o u t the reflector the p r o d u c e d the original ultrasonic echo. As in radar,
processing of echo features can be used to identify the reflector. Fig. 4 illustrates this concept. Imaging systems use arrays of ultrasonic signals o b t a i n e d from surface
Table 1 Commercially available automated UT systems/services - Hardware Intraspect 98
P-Scan
SOL-1000
SMART UT
UDRPS
Ultra Image 111
Zip-scan
V e n d o r - Service group:
Amdata Inc./CE
Independent Testing Labs. & Universal Testing Labs. Inc.
Sigma Research Inc.
General Electric Company
NES/Dynacon Systems Inc.
Ultra Image International
U.S.Testing Company Inc.
Automated scanner
AMAPS
AWS-4
SOL-1003
ALARA-1 or AMAPS
ALARA-1, AMAPS or VERSASCAN
ALARA-1 or AMAPS
MIMIC
MWS-2
SOL-1004
General Dynamics
VERSASCAN
Ultra Image std. minature
Rigid track flex-steel & mag. wheels or plastic belt
Rigid track or flex-steel & mag. wheels
Semi-automated scanner Guide track & mounting
Felx-steel with mag. wheels
Steel track with timing belt
Flex-steel with lock-on carpiage
Rigid track or flex-steel & mag. wheels
Scanner controller
Computer interfaced &joystick
Computer interfaced
Computer interfaced
Controller W / Computer auto or manual interfaced or computer &joystick interfaced
Transducer
Contact or booted
Contact
Contact & Contact immersion or booted
Contact, booted or mult. (6) array
Contact or booted
Contact
UTcomponents
Metrotek
P-Scan
SDL-1000
Ultra image III
Any commercial unit
Ultra Image III
Zipscan
Data storage
Hard disk & floppy & cassette
Magnetic tape cassette
Hard disk & floppy
Hard disk Hard disk. 9-track or & floppy & VHS of A-Scan optical disk or RF
Hard disk & floppy
Hard disk & floppy
Data display
RGB color CRT
B/w CRT
RGB color & B/W CRT
RGB color & B / W CRT
Ramtek color CRT
RGB Color & B / W CRT
B/W CRT
a/w &
VHS & color polaroid
Ramtek Versatec & techtronix color
Techtronix 4632/4634 & matrix color polaroid
3M VRG 40OO
Ultra image III
HP-1000 & AP 400 array processor
Ultra Image III Z-80 80286/8087 Z-80 80286/8087
LSI-11/73
Hardcopy unit
Computer - data processing
(2 EA.)
Techtronix & color polaroid
EPSON FX 80
HP 9836C
P-Scan processor
color polaroid SDL-1001
Flex-chain & non-metallic wheels
Controller W / Computer auto or manual interfaced or computer interfaced
268
M. Behrat, esh et al. / Status of adt,anced UT systems
scanning to create "pictures" of reflectors located within a material. The purpose of the images is to assist an inspector in obtaining information on the spatial char-
acteristics of his inspection problem. EPRI is currently examining systems that combine feature-based and image-based capabilities into, as they
Table 2 Commercially available automated UT systems/services - Software
Vendor group:
Service
Scan motion Acial Circumferential Skew
Data recording Amplitude Position Arrival time
RF waveform Rectified waveform Instrument settings
Intraspect 98
P-Scan
SDL-1000
SMART UT
UDRPS
Ultra Image II1
ZIP-Scan
Amdata Inc./CE
Independent Testing Lab & Universal Testing Lab
Sigma Research Inc.
General Electric Company
NES/Dynacon Systems Inc.
Ultra Image lnternatl
U.S.Testing Company Inc.
mmm mmm mmm
mmm mmm mmm
mmm mmm mmm
mmm mmm
mmm mmm
mmm mmm
mum mmm
mum
mmm
mmm
mmm
mmm mmm
mmm mmm
mmm mmm
mmu mmm
mmm mum
mmm mmm
mmm mmm
mmm mmm
mmm
mmm
mmm mmm
mmm mmm mmm mmm
mmm
mm• mmm mmm
mmm
mmm • mmm mmm
mmm mmm mmm mmm
mmm
mmm mmm mum mmm mmm mmm mmm mmm mmm
mmm mmm mmm
mmm mmm mmm
mmm
Data display A-Scan B-Scan C-scan 3-D Isometric
mmu mmm mmm •
Projected views Time-of-flight Flaw map
mum
mum
mmm
mmm mmm
mnm
mmm
Zoom
Dac curves Averaging Temporal averaging Spatial averaging Synthetic apeture Holography SAFT A rtificial intelligence ALW Feature extraction Pattern recognition Sitting techniques Tandem technique Mode conversion techniq Creeping wave Crack tip diffraction mmm fulll capability
•
partial capability
mmm mmm mmm
mmm
mmm
•
mmm mmm
mmm
mmm mmm
•
mmm •
•
mnm
•
mmm
mmm
mmm
mmm mum mum
mmm mum
mmm mmm mmm
mmm mmm
M. Behravesh et al. / Status of advanced UT systems
269
Fig. 3. The AMAPS mechanized scanner. Table 3 Commercially available components supporting automated UT systems System
Manufacturer
Function/Description
ALARA-1
Virginia Corp.
An automated mechanical scanner and scanner controller that can be interfaced to a computer. Mechanical system provides skew motion as well as standard scan motion. Rigid track and guide assembly.
ALN
Adaptronics/ Gen. Res. Corp.
Adaptive Learning Network (ALN) allows training of the system to distinguish key features of the U T signal unique to specific defects or conditions and assists the inspector in confirming defect or geometry conditions.
AMAPS
Amdata systems inc.
An automated mechanical scanner and scanner controller that can be interfaced to a computer. Configured for hard shoe or booted transducer assembly. Flex-steel, wrap around track with magnetic wheels.
ROBBI
Kraftwerk Union
An automated U T inspection system designed primarily for flaw sizing and not significantly used for initial inspection and detection. System is presently being reconfigured for full inspection use.
SDL-1000
Sigma Research Inc.
An automated U T inspection system capable of A, B, C and 3D scan imaging but principally designed for ultrasonic holography inspection and high resolution imaging of previously detected indications.
SUTARS
Southwest Research Institute
An ultrasonic tracking system used with manual U T to integrate scan position with UT data. Tracking sensors strap to pipe to provide position data for hand held transducer.
TEST PRO
Informetrics Inc.
IBM PC based hardware and software allows integration of all automated U T components and assories to provide fully automated U T system. PC is a value-added component to current automated U T systems. RF waveforms are recorded: artificial intelligence and pattern recognition algorithms are built into the software. Provides additional analysis capability using standard PC software such as Lotus 1-2-3.
270
M. Behral;esh et al.
/ Status qf adt, anced UT ~vstems
~quisition
R-F W A V E F O R M
Signal processing
/ /L ENVELOPE
peak Feature
extraction
ItT Pattern
recognition r Y = W 0 + W 1 • RT + W 2 • PD + W 3 " FT IF Y > T
Class 1
IF Y < T
Class
(crack)
2 (root)
Fig+ 4. Feature-based U T analysis concepts.
M. Behravesh et al. / Status of aduanced UT systems
271
Table 4 Not yet commercial automated UT systems and technologies System
Developers
Function/Description
ALOK
IzFP & Kraft Werk Union
Amplitude detection with time-of-flight signatures are used to detect flaw conditions. System uses standard UT transducers but is being upgraded to incorporate phased array transducer and will be capable of ALOK, ultrasonic holography and line SAFT imaging.
CUDAPS
EPRI & Adaptronics Gen. Res. Corp.
Computerized Ultrasonic Data Acquisition & Processing System (CUDAPS) incorporates ALN systems to provide a complete automatic UT system. Major components are ALN-4060 Flaw Discriminator, LSI-11 Microprocessor and AMAPS scanner controlled by an ALN-4033 Scan Controller. System has been configured at the EPRI NDE Center.
PVIS
EPRI & Sigma Research Inc.
Pressure Vessel Imaging System (PVIS) is an ultrasonic holography inspection system for heavy section steel inspection. The system can perform A, B, C, 3D and holographic imaging and integrate multiple images into final 3D images. System under evaluation at NDE Center.
SAFT
NRC, BattelleNorthwest & CE
Synthethic Aperture Focused Technique (SAFT) is a UT technology which provides focused UT images in the complete inspection volume. A transducer or point UT source is scanned over the volume surface and resulting UT data is analyzed to provide very high resolution focused UT image data at all points in the inspection volume.
Sector Scan
EPR1 & Vintek, Inc.
Real-time sector scan UT imaging uses a phased array or mechanically scanned transducer to provide real-time L and S wave images in a sector B-scan mode. Technology is similar to commonly used medical real-time sector scan units.
are conceived, feature-enhanced imaging systems. Considerations are being given to the use of Personal C o m puters (PC's) for the h a r d w a r e and software needs of these systems. Tables 1 a n d 2 cover systems that are in use today. T a b l e 1 lists the hardware that comprises these systems. The software and software function capability of these systems are listed in table 2. The systems m e n t i o n e d are not restricted to tables 1 and 2 hardware a n d software. T a b l e 3 describes commercially available c o m p o n e n t s that m a y be used as alternatives a n d / o r e n h a n c e m e n t s . Several U T systems that are still u n d e r d e v e l o p m e n t are listed in table 4.
4.
A major concern of the utility N D E m a n a g e r is the compliance of the system he chooses with N R C guidelines. The U S N R C has issued guidelines that define m i n i m u m acceptable performance requirements. Qualification tests have been developed to evaluate advanced U T systems against the established criteria defined by the N R C . Systems that have met all of the U S N R C requirements for I G S C C detection a n d sizing are listed in table 5.
5.
Table 5 Advanced systems satisfying IGSCC demonstration requirements System
Detection
Sizing
ALARA 1 ANL 4060 CUDAPS Intraspect P-Scan Sutars Robie Ultra Image III UDRPS Zipscan
x x x × x x
x
x x x
x x x × x
Qualification
Cost-effectiveness
A n o t h e r concern of the utility N D E m a n a g e r is the cost-effectiveness of inspections with advanced systems. Benefits most frequently cited by experienced utility users, service groups, a n d vendors are: - Better, a n d more complete coverage Traceable results - P e r m a n e n t recording Real-time results - Fewer o v e r / u n d e r calls D a t a comparison Post r e v i e w / a n a l y s i s Better reliability - Low-radiation exposure
70 95
140 140 40 550
4. Average M U T inspection speed: (weld i n c h e s / 1 0 h shift)
5. Average A U T inspection speed: (weld i n c h e s / 1 0 h shift)
6. Average number of welds inspected per outage
7. Average number of weld inches inspected per m a n per outage
These are for DOE work and may not be representative. Utility response - 3 out of 16 with 1 N.A. Vendor response - 9 out of 13 with 4 N.A. Total response - 41% Effective response 24%
Effective A U T / M U T cost ratio (item lb divided by item 9).
9. A U T / M U T benifits ratio
8. Benifits
1.00
3.00
3. Estimated A U T / M U T cost ratio
2.00 0.48
4.00 0.75
500
100
1.25
2.00
500
75
400
200
2.50
83 17 120 6000 20.83 5 5 20 " 150" 83.00 ~
7 93 40 1500 9 5 4 150 1,000 ?
90 10 25 1750 28.00 10 10 250 1,600 8.00
2. In your recent experience for an average UT inspection, what is the: (a) % A U T Inspection (b) % M U T Inspection (c) Total number of welds inspected (d) Total number of weld inches inspected (e) Estimated cost to the utility per weld inch (f) Average % repeat inspection including sizing (g) Average % sizing (h) Average radiation level at weld size ( m R / h ) (i) Average inspector (Level 1/ll) exposure per outage (j) Average cost per m R for total outage
3
35000 2.50
2
?
?
?
60
240
240
1.10
50 50 100 5000 50.00 10 7.5 50 600 ?
10000 1.00
4
Utility, Vandor or Service Group 1
1. Type of automated U T system. (GEDAS. Intraspect, P-Scan, U D R P S & G E S M A R T UT) 9000 1500 (a) Approximate inches of weld inspected (b) Estimated cost compared to equivalent manual U T inspection ( M U T ) 3.00 0.90
Table 6 A U T / M U T cost questionnaire summary 7 / 1 0 / 8 6
1.73
1.10
?
300
?
300
1.90
0 100 200 7500 '~ 1 1 30 1,200 ?
500 1.90
5
0.40
5.00
160
130
140
80
2.00
90 10 130 8380 61.00 20 2 500 1,200 9.23
67000 2.00
6
1.25
2.00
102
,)
q
2.50
,)
9
o
,)
9
q
9
q
,)
7190 2.50
7
0.56
3.82
302
222
132
2.15
83 17 116 6855 46.02 14 4 415 1,169 9.08
130190 2.14
Weighted average &totals
r,.--
I-J
314. Behraoesh et al. / Status of aduanced UT systems
Immediate sizing Documented data - Potentially lower cost. Many of the above benefits have significant long-term cost payoffs that are only realizable over a long time and are not immediately measurable. Each advanced system has different features and components which its marketing literature vigorously promotes. It is not always easy to identify the components or feature most important to a particular utility need. If a significant repair cost can be avoided because of the use of a U T system with advanced data display capabilities, it makes little difference if the system also possesses advanced pattern recognition capabilities. Both capabilities are equally important, but certainly not needed by all utility end users a n d / o r applications. To obtain cost information on a u t o m a t e d / a d v a n c e d U T inspection, a survey of the utilities, vendors, and service groups who have used such systems was conducted. Table 6 summarizes the findings of this survey. A total of 29 utilities and inspection service groups were surveyed. Twelve groups or 41% responded; how-
-
273
ever, several had no relevant data which gave an effective response of 21%. Those responding represent a total of more than 120000 inches of welds that have been inspected by advanced U T - about 1900 equivalent 20-inch diameter pipe welds. The data includes G E D A S , IntraSpect, P-Scan, and U D R P S inspection results. Recognizing that inspections with advanced U T systems provide benefits not readily available with manual UT, the initial equipment cost must be scaled accordingly to obtained the effective inspection cost. Specifically, to obtain the effective cost ratio of advanced U T to manual U T inspection ( A U T / M U T ) , the initial A U T / M U T cost ratio must be divided by the benefit ratio. The average initial A U T / M U T cost ratio was 2.12 - advanced U T inspection initially cost 2.12 times more than equivalent manual U T inspection; the average advanced U T to manual U T benefit ratio was 3.93. Therefore, the average effective A U T / M U T cost ratio is 0.64 and hence the effective cost of advanced U T inspection comes out to be less than two-thirds of the cost of equivalent manual U T inspection.