portable digital electronic radiography system

INIS-CA—0018

CANADIAN NUCLEAR SOCIETY

CA9800468

Third International Conference on

CANDU MAINTENANCE

Proceedings

NOVEMBER 19-21,1995 HOLIDAY INN ON KING TORONTO, CANADA

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FOREWARD These proceedings record the information presented at the 3rd International Conference on CANDU Maintenance held November 19-21, 1995 in Toronto, Canada. The papers for these proceedings were prepared electronically according to guidelines supplied by the Canadian Nuclear Society and are generally published as submitted by the authors. Responsibilityfor the content of each paper rests solely with the author. The proceedings are copyrighted by the Canadian Nuclear Society. Requests for farther information concerning these proceedings, permission to reprint any part of these proceedings, or orders for copies of these proceedings should be addressed to: Canadian Nuclear Society 144 Front Street West, Suite 725, Toronto, Ontario M5J2L7 Telephone: (416) 977-7620 Fax: (416)979-8356

CANDU MAINTENANCE CONFERENCE 1 9 9 5

PORTABLE DIGITAL ELECTRONIC RADIOGRAPHY SYSTEM Barbara D. Sawicka Nondestructive Testing Development Branch Engineering Technologies Division AECL, Chalk River Laboratories Chalk River, Ontario KOJ 1J0

CA9800479

time. Practical, cost saving applications of this system are expected to include valve monitoring and foreign object (debris) location during maintenance at CANDU reactors.

1. INTRODUCTION Radiography is a standard nondestructive technique in the industrial testing of materials and components. It is routinely used during the construction, maintenance and repair of nuclear plants. Traditionally, radiography is performed using photographic film (film radiography, FR). Recent developments in solid-state area-imaging radiation detectors, miniature electronics, and computer software/hardware techniques have brought electronic alternatives to FR (electronic radiography, ER) [1, 2]. In recent years various ER techniques have served as alternatives to FR; these proved beneficial in some applications. While originally developed to provide real-time imaging, ER may offer other advantages over FR, depending on the application.

2 . BACKGROUND INFORMATION The potential benefits of improved DER inspection methods for plant components are: (1) shorter exposure times and instant image retrieval, resulting in reduced personnel exposure and saved time; (2) digital images suitable for image enhancement, quantitative analysis and easy data storage; (3) larger dynamic range, permitting radiography outside the film range; and (4) elimination of the wet film processing, resulting in a reduction in radiographic-film, as well as film-processing hazardous-waste.

Commercially offered ER equipment mainly aims to provide real-time radiography on a production floor (with radiographs obtained using very short exposure times and without wet film processing). For that reason, while excellent results are obtained for fast inspection, image quality is usually degraded compared to film and the dynamic range is rather limited. Requiring high intensity radiation sources (X-ray generators) and comprising rather bulky detector units, the equipment is generally not suitable for field applications. At present, no turn-key ER instrument is available commercially in a portable version.

The following DER techniques were originally considered: storage screens, reverse geometry radiography (RGX), and solid-state imaging (SSI). While a close watch has been kept on competing technologies, the SSI-based technology was selected at CRL, as being the most promising option to develop for a portable DER system (most flexibility and the most advanced). Laboratory-type SSI systems were constructed at CRL, first in a simple version for proof-of-principle experiments, and then in a more advanced "semiprototype" version. New developments in area-imaging detectors, camera systems and computer software/hardware were used to construct the system. Various tests were performed to optimize system design and its performance. The semi-prototype system comprises compact components that to a large degree will be used in construction of a field prototype system.

Work was undertaken at CRL to review progress in ER techniques and evaluate the possibility of constructing a portable DER (digital electronic radiography) system, for the inspection of power plant components. A suitable DER technique has been developed and a proof-of-principle portable system constructed. As this paper demonstrates, a properly designed ER system can be small and compact, while providing radiographic examination with acceptable image quality and the benefits of ER imaging. The CRL DER system can operate with radioactive sources typical of FR.

3. SSI SYSTEM 3.1. Block diagram and radiation sources Figure 1 shows a block diagram of the DER system. In ER, X- or gamma-radiation from a radiation source is transmitted through the examined component/ object to the detector system, similar to FR. With our

While it does not replace FR, our DER system is expected to be beneficial in specific applications for CANDU maintenance, reducing cost, labour and

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CANDU MAINTENANCE CONFERENCE 1995 DER system, radiation is converted to a light image in an area-imaging scintillator, then picked up by a CCD (charge-coupled-device) sensor via a focusing lens, integrated over exposure time to create a noisefree signal, read-out (digitized) by the CCD camera electronics, and transferred to the PC computer RAM. The image can be viewed on a computer monitor, mathematically processed using image enhancement software, and transferred to permanent electronic storage, such as optical or magnetic disk.

feature is the large dynamic range assured by the linearity of camera response over a wide range of signal intensity. Dark field and bias field corrections are used to reduce noise and assure a wide linear range. A CCD format of 1024 x 1024 pixels was selected (suitable CCD array sizes range from 512 x 512 to 2048 x 2048), with a sensor size of 25 mm x 25 mm and 12-bit and 16-bit digitization levels. A user selected pixel format is possible with one sensor. The CCD camera permits various data acquisition times, from 0.1 s to hours, permitting corresponding various exposure times for radiography. The upper limit of the exposure duration is determined by either the dark current of the sensor or by oversaturation. The CCD sensor geometry and camera optics are important to the size and portability of the whole system.

Radiation sources over a wide range of energies can be used, from low-keV to MeV levels, including sources typical of FR, such as lr-192, Co-60, and Xray generators 3.2. Detector and enclosure Newly developed high-density glass scintillators [3, 4] and commercially developed phosphor screens are used as area-imaging scintillators. The output brightness of the scintillators was studied over the energy range 50 keV to 1.3 MeV. Tests included the use of reflective coating to increase the glass brightness, and metal screens to attenuate some of the scattered lower-energy X-rays.

3.4. Detector size and spatial resolution Large size detectors can be used with this technique; however, to keep the system small, a maximum detector size of 25 cm x 25 cm was selected. Optics can provide fields of view as small as 25 mm x 25 mm, up to the scintillator size. Two versions were constructed, with a scintillator size of 10 cm x 10 cm and 25 cm x 25 cm. It is expected that it will be impractical in field applications to manipulate the optics to change the field of view, especially over a large range; the use of fixed fields of view is recommended. The two system versions are therefore suggested for large and small objects, respectively, with lower and higher resolution. Areas larger than 25 cm will have to be radiographed in parts, and the image composed in a computer.

The area-imaging detector is secured in a light-tight enclosure (detector box, Figure 1), with interior lightabsorbing coatings to eliminate reflected light. A 45degree turning mirror is used to redirect the signal and position the CCD camera away from the radiation beam. The camera is shielded from direct and scattered radiation by tungsten or lead plates. The CCD camera can be either mounted directly in the box to pick up the signal from the focusing lens (direct coupling) or positioned away from the box, with the signal from the lens transmitted to the CCD sensor via a fiberoptic cable (cable coupling). The first option is preferred, as cable coupling causes some image degradation. Tests with cables comprising one million fibers were performed. Cables up to several meters long can be used, without major degradation in signal intensity. Some degradation in image quality and resolution is observed (there is a characteristic "chickenwire" effect and some "dead" pixels); however, this will be insignificant in low resolution imaging. Improvement in image transmission quality can be expected with cables comprising several times more fibers, which at present is impractical (and expensive).

The spatial resolution of a DER system is determined by the pixel number, pixel size relative to the system field of view, the resolution of the scintillating detector, the source size and geometry. With our system, the first three factors are most significant under typical geometry, while source size is important only at very close source-to-detector (S-D) distances. Spatial resolution was tested using image quality indicators (IQI) suitable for high energy radiography. The fields of view of 10 cm x 10 cm and 25 cm x 25 cm provided spatial resolution of 5 Ip/mm (line pairs per mm) and 2 Ip/mm, respectively, in agreement with estimates based on detector size and CCD format. Figure 2 shows a photograph of the detector box (the scintillator of 10 cm x 10 cm), with the CCD camera attached to the box (direct coupling), and a portable industrial computer for data collection and image analysis.

3.3. CCD camera A CCD-array, electronically cooled camera is used, with a fast read-out and high-bit level; the CCD sensor features high sensitivity, high gain, high resolution, and high electronic well capacity. An important

3.5. Image viewing and data processing The computer is used for CCD control, data acquisi72

CANDU MAINTENANCE CONFERENCE 1995 tion, data viewing and preliminary data acquisition. The computer is equipped with 24 Mb RAM and a 0.5 Gb hard disk. With each image requiring about 1 Mb space, this permits a large number of images (up to 500) to be stored and processed. More images are stored on optical disks, each sufficient for more than 100 full size images. Optical disks also provide permanent data archiving.

details are clearly seen in the water-free area, as well as aluminum rods (6 mm in diameter) and some details of the valve exterior and interior. While the flapper in the water is not well represented in this print, its position and some details can be clearly detected through numerical analysis of the data. The image below shows the valve parts under water, not observed in the top image. The image was obtained by .subtracting the image of a similar valve measured without water. While in field applications one cannot expect to be able to take shots of a component empty and full of water, one can store a set of reference images in computer memory. Typical FR shot of this valve would require much longer exposure times at similar exposure conditions.

After exposure, a radiographic image is instantly displayed on the PC monitor. The PC is equipped with image processing software, for mathematical image and data processing, such as filtering, algebraic and statistical operations, and display, with various magnification factors and thresholding. For more advanced data processing, it is more convenient to transfer images to a laboratory computer equipped with a large monitor (Figure 1). Image format provides easy archiving in both computer hard disk and storage disks, which also assures easy data access and retrieval. Both IBM PC and MAC platforms have been used.

5. COMPARISON WITH FILM RADIOGRAPHY AND APPLICATIONS For the fields of view of 10 cm to 25 cm, the spatial resolution of the ER system is 5 to 2 Ip/mm, respectively, which is less than is usually achievable with FR. For small fields of view, the DER system can provide a spatial resolution up to 20 Ip/mm.

4 . EXAMPLES OF RADIOGRAPHIC EXAMINATION

The contrast sensitivity of the ER system was tested using some plate image indicators, and found to be close to (not better than) that for FR.

To illustrate the DER technique and its possible applications, several radiographs are shown below, measured using an lr-192 source. Note that the printed version presents only one of many possible representations of a digital radiograph, and that it does not reproduce the true quality of the image viewed on a computer screen.

The advantage of ER over FR is in exposure times. A radiographic examination of components using our DER system is at least 10 times shorter than that performed using FR at similar exposure conditions. This was confirmed for both small and large and thick components. For example, DER measurements presented above can be compared with FR shots taken for the same components. To make the measurements comparable, one has to correct for source activity and the S-D distance. (The ER measurements were performed with a S-D distance of close to 2 m, because of geometrical restrictions of the shielding flask; shorter distances, similar to FR, will normally be used.) The FR for two small valves, performed using a 30 Ci source and the S-D distance of 0.6 m, required exposure times of 1000 s. Corrected for SD distance, that means exposure times up to 25 times longer than for the DER system. For a large 8" valve, typical FR exposure times (exposure time of 5500 s (1.5 h), using a 37 Ci source and the S-D distance of 0.6 m), when corrected for examination conditions, are also about 10 to 20 times longer. The much shorter exposure time combined with image viewing shortly after exposure allows one to optimize inspection in timely manner.

Figure 3 shows a digital radiograph of a small valve, which was measured with 4800 Ci.s (source activity of 48 Ci, exposure time 100 s, S-D distance 1.9 m). Similar images of this valve were obtained using longer (twice) and shorter (up to 10 times) exposure times. Figure 4 (left) shows a digital radiograph of a small valve half filled with water. Geometry and exposure conditions were as in Figure 3. The water level and water-filled areas, observed in the image, can be enhanced by thresholding the image data. One can also subtract radiographs measured for the valve with and without water (bottom image), which results in a dramatic increase in sensitivity for the water area representation. This last operation illustrates one type of image processing, possible with digital images. Figure 5 shows radiographs of a check valve (Newco 33wcb2, 8 NPS, 300 lbs) from Darlington nuclear generating station. The top radiograph was measured with 30,000 Ci.s (20 Ci source, exposure time 1600 s, S-D distance 1.9 m). In the image, flapper

Due to a greater sensitivity of the scintillator/ CCD camera system in comparison to film, with our DER 73

CANDU MAINTENANCE CONFERENCE 1995 system one can use a low energy (lr-192) source for some inspections, which with FR would require higher energy (Co-60) source. Because DER features a wider dynamic range than film, exposure time does not have to exactly match the object thickness and detector sensitivity (contrary to film). This provides an advantage in cases when object thickness or material properties are not known (such as debris). Also, because with DER a single exposure can cover a wide range of thicknesses, single exposure would be sufficient in some cases where multiple exposures are needed with FR. Finally, the digital form of ER images permits the use of advanced data processing and mathematical image-enhancement techniques and computerbased data storage, which is compact, permits easy data access and retrieval and with soft- and hard-multicopies readily available.

strated in the laboratory and work on field trials is in progress. Compared to typical real-time radiography systems, our DER system offers higher sensitivity, wider dynamic range and portability. Compared to film radiography, this system offers imaging without wet film processing, the possibility of considerably shorter inspection times, easy-to-archive information and the option of mathematical data processing. Exposure times for the present system are typically one tenth those needed for film, and an lr-192 source can be used instead of Co-60 to inspect some thick components. The spatial resolution of the system is usually worse than FR (for a typical 10 cm x 10 cm area detector the spatial resolution is about 4 Ip/mm, and respectively lower and higher for larger and smaller area detectors). Contrast sensitivity is typically similar to that of film radiography. While not replacing film radiography in its standard use, in some applications this electronic radiography system will enable more reliable and faster inspection. Practical, cost-saving uses of this system are expected to include applications such as valve monitoring and foreign object (debris) location during maintenance at CANDU reactors.

The following possible uses of ER in nuclear generating stations have been identified: (1) valve monitoring, including operation of valve internals, (2) foreign object location (such as debris), and (3) monitoring of localized wall loss in reactor piping.

ACKNOWLEDGEMENTS 6. SYSTEM PORTABILITY AND FIELD TESTS

The author appreciates the contribution of the NDT Development Branch personnel, E. Nicholson and K. Sonnenburg, in construction and testing of the SSI laboratory system. Thanks are due to M. Barker and C. Bueno from Lockheed Missiles and Space Co. Inc. NDT Laboratory for discussions on various ER options and SSI properties. Much of this work was supported by the CANDU Owners Group (COG).

The present system will be ready for field tests after only minor modifications. All system components will be secured on a cart, and the detector box will be equipped with attachments for pipes or valves for exposure. Field tests at CANDU stations are being planned with Ontario Hydro personnel.

7. SUMMARY AND CONCLUSIONS

REFERENCES

A novel portable system for radiographic inspection of components, materials and systems has been developed. This is a digital electronic radiography (DER) system, based on the SSI (solid state imaging) technology. Radiographic imaging is performed using a gamma- and X-ray area-imaging scintillator coupled to a high dynamic range, high-bit level CCD camera and a portable industrial computer. Sources typical of film radiography can be used (Co-60, lr-192 and X-ray generators). Radiographs are obtained as digital images, which are displayed on a monitor and stored in a computer memory and on optical disks, for easy data access and further data evaluation. Digital radiographs can be mathematically processed to improve detection sensitivity.

1. "Standard Guide for Radioscopic Real-time Imaging", 1989 Annual Book of ASTM Standards, Sec. 3, Vol. 03.03 (Nondestructive Testing), E1000-89. 2. "Standard Guide for Radioscopy", 1992 Annual Book of ASTM Standards, Sec. 3, Vol. 03.03 (Nondestructive Testing), E1000-92.

The performance of the system has been demon74

3.

C. Bueno and M.D. Barker, "High-resolution Radiography and Three-Dimensional Computed Tomography", SPIE No 2009-21 (1993).

4.

R.C. Placious, D. Polansky, H. Berger, C. Bueno, C.S. Vosberg, R.A. Betz and D.J. Rogerson, "High Density Glass Scintillator for Real-time Xray Inspection", Materials Evaluation 42, no 11: 1419-1421 (1991).

CANDU MAINTENANCE CONFERENCE 1995

f RADIATION I SOURCE

DETECTOR SYSTEM Object at 2xg«orT»tric magnification

DATA PROCESSING AND STORING

Cbjwaal IX geometric magnification

Mirror

Detecior-fo-CCD coupling Radiation shielding

CCO camera

High resolution monitor

Electronics and temperature control

Corrputer for advanced data and image processing

Graphics terminal

Portable computer'

•PC lor control, data acquisition, preliminary data processing and viewing

Figure 1: Block diagram of the SSI system

Figure 2: Photograph of the detector box and computer for data acquisition, preliminary processing and viewing.

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Storage disc


Figure 3: Radiograph of a valve, measured using exposure time of 100 s, with 48 Ci lr-192 source and the S-D distance of - 2 m. Film radiography required more than 10 times longer exposure time, at the same geometry and source intensity.

Figure 4: Left: Radiograph of a small valve half filled with water. {Exposure conditions as in Figure 3). Water leve! and water areas, seen in the valve cavity, can be enhanced by thresholding the image data. To the right is shown the image obtained after subtracting radiographs measured for the valve with and without water, hence showing water only.

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Figure 5: Top: radiograph of an 8 " check valve from Darlington NGS station (20 Ci source, S-D distance ~2 m, exposure time 1600 s). The valve was half filled with water; the image shows valve flapper, aluminum rods (6 mm in diameter) and some details of the valve exterior and interior. Bottom: the result of image subtraction to show portions of the valve containing water.

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CONFERENCE ORGANIZING COMMITTEE Honorary Chair

Ron Field

General Manager Ontario Hydro Nuclear Committee Chair

Mark Brown

Ontario Hydro Technical Program

TimAndreeff

Ontario Hydro Martin Reid

Ontario Hydro Exhibit Co-ordinators

Heather Smith AECL Donna Roach AECL Ronnie Faulkner AECL

Publications

Tim McLaughlin GE Canada

Registration

Sylvie Caron CNS/CNA

Treasurer

John Marczak

Ontario Hydro Advertising and Promotion

Ed Price AECL

Conference Facilities

Isabel Franklin AECL

Plenary Session and Guest Speakers

Vic Luukkonen AECL Ernie Aikens AECL

Secretary

Eva Marczak

Ontario Hydro Site Representatives

Karel Mika

Ontario Hydro Marlene Ramphal

Ontario Hydro Peter Richinson AECL Jim Wills AECL


TABLE OF CONTENTS SESSION 1A - PREDICTIVE MAINTENANCE Using the Time Domain Reflectometer to Check for and Locate a Fault M. Ramphal, E. Sadok, Ontario Hydro, Darlington Development and Implementation of the Bruce B Secondary Side Flow Accelerated Corrosion Program D.E. Stephenson, Ontario Hydro, Bruce B

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SESSION I B - RELIABILITY IMPROVEMENTS - 1 RCM: The Bruce B Experience Earl S. Hill, NUS Corporation, Gaithersburg, Maryland, U.S.A. E. Kevin Doyle, Ontario Hydro, Bruce B

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Darlington NGD Preventive Maintenance Enhancement Program

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D.J. Phillips, Ontario Hydro, Darlington

SESSION 1C - EMERGING ISSUES Bruce NGS A Unit 4 Preheater Divider Plate Failure M. Langridge, D. Mclnnes, Ontario Hydro, Bruce A Relief Valve Failure on Pickering Unit 2 R. Goodman, Ontario Hydro, Pickering (Paper Not Available)

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SESSION I D - STEAM GENERATOR MONITORING & STRATEGY Non-Intrusive Downcomer Flow Measurements: A Means of Monitoring Steam Generator Performance C.E. Taylor, J.E. McGregor, C.A. Kittmer and M.J. Pettigrew, AECL E.R Jelinski, D.A. Seppala, Ontario Hydro, Darlington

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Darlington Steam Generator Life Assurance Program E. Jelinski, M. Dymarski, Ontario Hydro, Darlington C. Maruska, E. Cartar, Ontario Hydro, Nuclear Technology Services

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Corrosion-Product Inventory: The Bruce-B Secondary System J.A. Sawicki, AECL J. Price, Ontario Hydro, Bruce B M.E. Brett, Ontario Hydro, Nuclear Technologies Services

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SESSION IE - TOOLS AND INSTRUMENTATION Portable Radiation Instrumentation Traceability of Standards & Measurements A. Wiseman, M. Walke, Ontario Hydro, Bruce B The Role of a Certified Calibration Laboratory in a Station's Measuring and Test Equipment Calibration, Repair, and Documentation Program K. Ebenstreit, N. Macintosh, Ontario Hydro, Bruce B (iii)

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CANDU MAINTENANCE CONFERENCE 1995 Portable Digital Electronic Radiography System

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B. Sawicka, AECL

SESSION 2A - IMPVORING VALVE PERFORMANCE Air Operated Valve Maintenance at Bruce 'A' K. McLeod, Ontario Hydro, Bruce A Implementation Challenges of a Motor Operated Valve Program T.L. Ferguson, Ontario Hydro, Bruce B Darlington NGD Liquid Injection Shutdown System (LISS) Valve Performance M. Wightman, F. Amantea, B. Speer, A. Rouhi, Ontario Hydro, Darlington

79 87 93

SESSION 2 B - FUEL CHANNEL INSPECTION AND MAINTENANCE - 1 Fuel Channel Replacement Experience at Wolsong Unit 1 B.S. Han, Korea Electric Power Corporation M. Macit Cobanoglu, AECL

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Removal of a Seized Fuel Channel from the Kanupp Reactor W. Butt, Karachi Nuclear Power Plant R. Gunn, AECL

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Wet Scrape Sampling Campaign: Bruce 'B' Unit 6, Spring '95

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S. Bennett, Ontario Hydro, Bruce B

SESSION 2 C - STEAM GENERATOR MAINTENANCE Gentilly2 Divider Plate Replacement J. Forest, Hydro Quebec E. Kiisel, G. McClellan, W. Schneider, Babcock & Wilcox Recent Developments in Plugging of Steam Generator Tubes S. Buhay and R.C. Abucay, Ontario Hydro, Nuclear Technology Services

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SESSION 2 D - ENVIRONMENTAL QUALIFICATION Maintenance and Environmental Qualification R.S. Martin, United Energy Services Inc. D.G. Austin, Ontario Hydro, Pickering

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Environmental Qualification - Walkdowns: The Documentation of Configuration Information for Safety Related Components, Equipment and Systems J. Melmer, Ontario Hydro, Pickering Environmental Qualification Program for Wolsong Project A. Duggal, H. Johal, F. Yee, AECL S-K. Suh, Korea Atomic Energy Research Institute

129 137

SESSION 2E - PREDICTIVE MAINTENANCE - 2 Validation of the Dynamics of SDS and RRS Flux, Flow, Pressure and Temperature Signals Using Noise Analysis Techniques 0. Glockler, D.F. Cooke, Ontario Hydro, Nuclear Technology Services M.V. Tulett, Ontario Hydro, Pickering (iv)

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CANDU MAINTENANCE CONFERENCE 1995 Portable System for Reactor Noise Data Acquisition ST. Craig, P.D. Tonner, J.P. Johnston, L.E. Nicholson, AECL 0. Glockler, Ontario Hydro, Nuclear Technology Services D. Williams, Ontario Hydro, Pickering

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Flow-Accelerated Corrosion in Nuclear Power Plants: Application of Checworks™ at Darlington C. Schefski and J. Pietralik, AECL T. Dyke, Ontario Hydro, Darlington M. Lewis, Ontario Hydro, Pickering

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SESSION 3A - INSTRUMENTATION & CONTROL - 1 A Requirements Checklist for the Replacement of Analog Fischer and Porter Process Controllers with New Digital Models A. Beauchamp, AECL Upgrading from the Dicon Wiring Management System to IntEC at the Gentilly 2 Station P. Theoret, Hydro-Quebec

155 157

Operating Experience in Engineering and Instrumentation & Control Areas Regarding a Candu 600 Refuelling System E. Binetti et al, Nucleoelectrica, Argentina (Paper not Available)

SESSION 3 B - FUEL CHANNEL INSPECTION MAINTENANCE - 2 Slarette Operations at Candu 6 Stations D.J. Burnett, AECL

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Design of the Minislar System for Bruce A M.G. Gray, GE Canada Nuclear Products

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Advanced Slarette Delivery Machine R.R. Bodner, AECL

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Fuel Channel Conditions Encountered During Slar and the Implications on Slar Strategies J. Gierlach, Ontario Hydro, Nuclear Technology M. Furniss, Ontario Hydro, Bruce A P. Gauthier, Hydro-Quebec P. Ahearn, New Brunswick Power

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SESSION 3C - STEAM GENERATOR CLEANING Water Lancing of Bruce-A Unit 3 and 4 Steam Generators F. Puzzuoli, Ontario Hydro, Nuclear Technology Services B. Murchie, S. Allen, Ontario Hydro, Bruce A

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Steam Generator Waterlancing at DNGS D. Seppala, Ontario Hydro, Darlington E. Kiisel, F. Kamler, Babcock & Wilcox J. Malaugh, Ontario Hydro, Nuclear Technology Services,

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Steam Generator Secondary Side Chemical Cleaning at Point Lepreau using the Siemens High Temperature Process K. Verma, C. MacNeil, New Brunswick Power Dr. S. Odar, K. Kuhnke, Siemens

(v)

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CANDU MAINTENANCE CONFERENCE 1995 Pickering Unit 1 Chemical Cleaning J.L. Smee, Niagara Technical Consultants R.J. Fiola, B&W Nuclear Technologies K.R. Brennenstuhl, D.D. Zerkee, C M . Daniel, Ontario Hydro, Pickering

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SESSION 3 D - PREDICTIVE MAINTENANCE - 3 Elastodynamic Spot Testing - Assessing Serviceability of Aging Elastomer Parts B. Gracie, R. Metcalfe, R. Wensel, AECL

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Check Valve Diagnostic Program at Bruce A S. Marsh, Ontario Hydro, Bruce A (Paper not Available) The Role of Lubricant Analysis in Maximizing Lubricant and Equipment Life J. Janis, Ontario Hydro Technologies

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Condition Based Maintenance Pilot Projects at Pickering ND R.T. Zemdegs, Ontario Hydro, Nuclear Technology Services F.K. Fitzsimmons, Ontario Hydro, Pickering

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SESSION 3E - DECONTAMINATION AND RADIATION PROTECTION PND Fuel Handling Decontamination Program: Specialized Techniques and Results R. Pan, K. Hobbs, M. Minnis, K. Graham, Ontario Hydro, Pickering

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Decontamination and Recovery of Materials at Nuclear Facilities - Operating History RJ. Gillis, Non-Destructive Cleaning Inc. J. Ackeroyd, J. Ackeroyd & Associates

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Rehabilitation Activities and Radiation Protection Requirements in a Candu Facility J.K. Mohindra, D. Papavramidis, I. Lake, Ontario Hydro, Pickering

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SESSION 4A - INSTRUMENTATION AND CONTROL - 2 Gentilly 2 Digital Control Computer Maintenance Strategy P. Meloncon, J. Hubert, N. Gour, Hydro Quebec (Paper not Available) Evaluation of Candu Safety-System Calibration Accuracy Through Monitoring H.W. Hinds, AECL R. MacKay, Ontario Hydro, Bruce B

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Point Lepreau NGS RTD Cable Assembly Failure & Replacement Program M.P. Callister, New Brunswick Power

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SESSION 4 B - FUEL CHANNEL PROGRAM OPTIMIZATION Fuel Channel In-Service Inspection Programs Program Design for Maximum Cost Effectiveness N. van den Brekel, Ontario Hydro, Nuclear Technology Services Fuel Channel Life Limiting Factors that Dictate Fuel Channel Maintenance Requirements P.J. Richinson, H.W. Wong, AECL P.J. Ellis, Ontario Hydro, Reactor Engineering Services Department (vi)

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CANDU MAINTENANCE CONFERENCE 1995 New Concepts, Requirements and Methods Concerning the Periodic Inspection of the Candu Fuel Channels J.R Denis, Ontario Hydro, Nuclear Technology Services M. Soare, Institute for Nuclear Research, Romania

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SESSION AC - INSPECTION TECHNIQUES Transm'rt-Receive Eddy Current Probes for Defect Detection and Sizing in Steam Generator Tubes LO. Obrutsky, T. Harasym, V.S. Cecco and S.P. Sullivan, AECL

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Ultrasonic Inspection of Electrosleeved Steam Generator Tubing D.R Jansen, M.D.C. Moles, W.K. Chan, H.D. Mair, Ontario Hydro Technologies E.I. Choi, Ontario Hydro, Nuclear Technology Services

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Eddy Current Technique for Detecting and Sizing Surface Cracks in Steel Components

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V.S. Cecco, J.R. Carter, S.P. Sullivan, AECL

SESSION 4 D - RELIABILITY INPROVEMENTS - 2 Primary Heat Transport Pump Mechanical Seal Replacement Strategy for Pickering B V. Chacinski, Ontario Hydro, Pickering Upgrading Primary Heat Transport Pump Seals T. Graham, R. Metcalfe, D. Rhodes, AECL D. Mclnnes, Ontario Hydro, Bruce A Inflatable Door Seals - Reduced Maintenance and Longer Service-Life S. Kuran, R. Wensel, AECL M. Lazic, Ontario Hydro, Nuclear Technology Services

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SESSION 4E - MAINTENANCE PROGRAM STRATEGIES - 1 The Development of a Station Maintenance Strategy F. Fitzsimmons, R. Bearton, Ontario Hydro, Pickering T. Andreeff, Ontario Hydro, FBS Atomic Energy Control Board (AECB) Staff Assessment and Views of Current Maintenance Practices at a Four Unit Candu Plant I. Malek, Atomic Energy Control Board

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Peer Evaluation Experience with Maintenance Program Evaluation F. Saunders, M. Gerard, Ontario Hydro, Nuclear Safety Division

SESSION 5A - VALVE PACKING EXPERIENCE Control Valve Friction Operational Experience at Darlington NGD B. Speer, Ontario Hydro, Darlington Darlington NGD Valve Packing Program C. Spence, Ontario Hydro, Darlington BNGS B Valve Packing Program D. Cumming, Ontario Hydro, Bruce B

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CANDU MAINTENANCE CONFERENCE 1995 SESSION 5B - REMOTE TOOLING / ROBOTICS Mobile Robotics for Candu Reactor Maintenance: Case Studies and Near-Term Improvements M.G. Lipsett, AECL K.H. Rody, Ontario Hydro, Bruce B

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Ring Thermal Shield Piping Modification at Pickering Nuclear Generating Station 'A' Unit 1 R. Brown, Ontario Hydro, Pickering M. Macit Cobanoglu, AECL

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ARK-2: A Mobile Robot that Navigates Autonomously in an Industrial Environment N. Bains, AECL S. Nickerson, D. Wilkes, Ontario Hydro Technologies

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SESSION 5C - FUEL HANDLING Underwater Fuel Handling Equipment Maintenance Verification of Design Assumptions, Specific Problems and Tools, Case Study J. Kurek, Ontario Hydro, Pickering

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Ultrasonic System for High-Accuracy Thickness Measurement of Fuel Bundle Bearing Pads and Shield Plug Crimps P. Ciorau, B. Bevins, L. Gilham, Ontario Hydro, Nuclear Technology Services

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Darlington NGD Fuel Handling Head Eight Acceptance Program PH. Skelton, T. Sie, Ontario Hydro, Darlington J. Pilgrim, GE Canada, Nuclear Products

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SESSION 5D - RELIABILITY IMPROVEMENTS - 3 Improved Reliability, Maintainability and Safety Through Elastomer Upgrading R. Wensel and K.C. Wittich, AECL

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Status of the Reliability Centered Maintenance Program at Ontario Hydro's Bruce 'A' Nuclear Division I. Khan, Ontario Hydro, Bruce A

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Information Management for Maintenance of Instrument Calibration Data

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