WorldWideScience

Sample records for based inspection techniques

  1. Development of the Risk-Based Inspection Techniques and Pilot Plant Activities

    International Nuclear Information System (INIS)

    Phillips, J.H.

    1997-01-01

    Risk-based techniques have been developed for commercial nuclear power plants. System boundaries and success criteria is defined using the probabilistic risk analysis or probabilistic safety analysis developed to meet the individual plant evaluation. Final ranking of components is by a plant expert panel similar to the one developed for maintenance rule. Components are identified as being high risk-significant or low-risk significant. Maintenance and resources are focused on those components that have the highest risk-significance. The techniques have been developed and applied at a number of pilot plants. Results from the first risk-based inspection pilot plant indicates that safety due to pipe failure can be doubled while the inspection reduced to about 80% when compared with current inspection programs. The reduction in inspection reduces the person-rem exposure resulting in further increases in safety. These techniques have been documented in publication by the ASME CRTD

  2. Eye gazing direction inspection based on image processing technique

    Science.gov (United States)

    Hao, Qun; Song, Yong

    2005-02-01

    According to the research result in neural biology, human eyes can obtain high resolution only at the center of view of field. In the research of Virtual Reality helmet, we design to detect the gazing direction of human eyes in real time and feed it back to the control system to improve the resolution of the graph at the center of field of view. In the case of current display instruments, this method can both give attention to the view field of virtual scene and resolution, and improve the immersion of virtual system greatly. Therefore, detecting the gazing direction of human eyes rapidly and exactly is the basis of realizing the design scheme of this novel VR helmet. In this paper, the conventional method of gazing direction detection that based on Purklinje spot is introduced firstly. In order to overcome the disadvantage of the method based on Purklinje spot, this paper proposed a method based on image processing to realize the detection and determination of the gazing direction. The locations of pupils and shapes of eye sockets change with the gazing directions. With the aid of these changes, analyzing the images of eyes captured by the cameras, gazing direction of human eyes can be determined finally. In this paper, experiments have been done to validate the efficiency of this method by analyzing the images. The algorithm can carry out the detection of gazing direction base on normal eye image directly, and it eliminates the need of special hardware. Experiment results show that the method is easy to implement and have high precision.

  3. Evaluation of computer-based NDE techniques and regional support of inspection activities

    International Nuclear Information System (INIS)

    Taylor, T.T.; Kurtz, R.J.; Heasler, P.G.; Doctor, S.R.

    1991-01-01

    This paper describes the technical progress during fiscal year 1990 for the program entitled 'Evaluation of Computer-Based nondestructive evaluation (NDE) Techniques and Regional Support of Inspection Activities.' Highlights of the technical progress include: development of a seminar to provide basic knowledge required to review and evaluate computer-based systems; review of a typical computer-based field procedure to determine compliance with applicable codes, ambiguities in procedure guidance, and overall effectiveness and utility; design and fabrication of a series of three test blocks for NRC staff use for training or audit of UT systems; technical assistance in reviewing (1) San Onofre ten year reactor pressure vessel inservice inspection activities and (2) the capability of a proposed phased array inspection of the feedwater nozzle at Oyster Creek; completion of design calculations to determine the feasibility and significance of various sizes of mockup assemblies that could be used to evaluate the effectiveness of eddy current examinations performed on steam generators; and discussion of initial mockup design features and methods for fabricating flaws in steam generator tubes

  4. a Holistic Approach for Inspection of Civil Infrastructures Based on Computer Vision Techniques

    Science.gov (United States)

    Stentoumis, C.; Protopapadakis, E.; Doulamis, A.; Doulamis, N.

    2016-06-01

    In this work, it is examined the 2D recognition and 3D modelling of concrete tunnel cracks, through visual cues. At the time being, the structural integrity inspection of large-scale infrastructures is mainly performed through visual observations by human inspectors, who identify structural defects, rate them and, then, categorize their severity. The described approach targets at minimum human intervention, for autonomous inspection of civil infrastructures. The shortfalls of existing approaches in crack assessment are being addressed by proposing a novel detection scheme. Although efforts have been made in the field, synergies among proposed techniques are still missing. The holistic approach of this paper exploits the state of the art techniques of pattern recognition and stereo-matching, in order to build accurate 3D crack models. The innovation lies in the hybrid approach for the CNN detector initialization, and the use of the modified census transformation for stereo matching along with a binary fusion of two state-of-the-art optimization schemes. The described approach manages to deal with images of harsh radiometry, along with severe radiometric differences in the stereo pair. The effectiveness of this workflow is evaluated on a real dataset gathered in highway and railway tunnels. What is promising is that the computer vision workflow described in this work can be transferred, with adaptations of course, to other infrastructure such as pipelines, bridges and large industrial facilities that are in the need of continuous state assessment during their operational life cycle.

  5. A HOLISTIC APPROACH FOR INSPECTION OF CIVIL INFRASTRUCTURES BASED ON COMPUTER VISION TECHNIQUES

    Directory of Open Access Journals (Sweden)

    C. Stentoumis

    2016-06-01

    Full Text Available In this work, it is examined the 2D recognition and 3D modelling of concrete tunnel cracks, through visual cues. At the time being, the structural integrity inspection of large-scale infrastructures is mainly performed through visual observations by human inspectors, who identify structural defects, rate them and, then, categorize their severity. The described approach targets at minimum human intervention, for autonomous inspection of civil infrastructures. The shortfalls of existing approaches in crack assessment are being addressed by proposing a novel detection scheme. Although efforts have been made in the field, synergies among proposed techniques are still missing. The holistic approach of this paper exploits the state of the art techniques of pattern recognition and stereo-matching, in order to build accurate 3D crack models. The innovation lies in the hybrid approach for the CNN detector initialization, and the use of the modified census transformation for stereo matching along with a binary fusion of two state-of-the-art optimization schemes. The described approach manages to deal with images of harsh radiometry, along with severe radiometric differences in the stereo pair. The effectiveness of this workflow is evaluated on a real dataset gathered in highway and railway tunnels. What is promising is that the computer vision workflow described in this work can be transferred, with adaptations of course, to other infrastructure such as pipelines, bridges and large industrial facilities that are in the need of continuous state assessment during their operational life cycle.

  6. An Eddy Current Testing Platform System for Pipe Defect Inspection Based on an Optimized Eddy Current Technique Probe Design

    Science.gov (United States)

    Rifai, Damhuji; Abdalla, Ahmed N.; Razali, Ramdan; Ali, Kharudin; Faraj, Moneer A.

    2017-01-01

    The use of the eddy current technique (ECT) for the non-destructive testing of conducting materials has become increasingly important in the past few years. The use of the non-destructive ECT plays a key role in the ensuring the safety and integrity of the large industrial structures such as oil and gas pipelines. This paper introduce a novel ECT probe design integrated with the distributed ECT inspection system (DSECT) use for crack inspection on inner ferromagnetic pipes. The system consists of an array of giant magneto-resistive (GMR) sensors, a pneumatic system, a rotating magnetic field excitation source and a host PC acting as the data analysis center. Probe design parameters, namely probe diameter, an excitation coil and the number of GMR sensors in the array sensor is optimized using numerical optimization based on the desirability approach. The main benefits of DSECT can be seen in terms of its modularity and flexibility for the use of different types of magnetic transducers/sensors, and signals of a different nature with either digital or analog outputs, making it suited for the ECT probe design using an array of GMR magnetic sensors. A real-time application of the DSECT distributed system for ECT inspection can be exploited for the inspection of 70 mm carbon steel pipe. In order to predict the axial and circumference defect detection, a mathematical model is developed based on the technique known as response surface methodology (RSM). The inspection results of a carbon steel pipe sample with artificial defects indicate that the system design is highly efficient. PMID:28335399

  7. Airplane tire inspection by image processing techniques

    OpenAIRE

    Jovancevic , Igor; Arafat , Al; Orteu , Jean-José; Sentenac , Thierry

    2016-01-01

    International audience; In this paper, we propose a new approach to detect and inspect airplane tires. We use normalized correlation based template matching to detect tires and GrabCut segmentation method to extract them from the background. We inspect the tires condition by investigating the tire treads. Ridge based intensity profiling gives satisfying inspection results.

  8. Employing innovative techniques to reduce inspection times

    International Nuclear Information System (INIS)

    Heumueller, R.; Guse, G.; Dirauf, F.; Fischer, E.

    1997-01-01

    Shorter inspection periods mean lower revision costs and less tight revision schedules, but must not detract from the quality of inspection findings. This requirement imposes upon the company performing the inspection the need for top achievements both in quality management and in the use of innovative techniques. Flexible equipment systems and inspection techniques adapted to specific purposes are able to reduce inspection times in many inspection jobs. As part of a complete system designed to reduce inspection times, the new Saphir (Siemens Alok Phased Array Integrated Reliable UT-System) inspection equipment system is the core of most of the recent innovations. Being an integrated inspection equipment system, it is able to handle conventional US probes as well as arrays and phased arrays. It is open for further matching to specific inspection and administrative requirements and developments, and it may be incorporated in the network of an integrated system with a database. A technological leap in probe design in the past few years has allowed controllable wave fields to be generated which are in no way inferior to those of conventional probes with fixed angles of incidence. In this way, a number of inspection techniques can be implemented with a single probe. This reduces inspection times, setup and retooling times, and doses. Typical examples already used in practice are the LLT (longitudinal-longitudinal-transverse waves) technique and the integration of inspections for longitudinal and transverse defects in a single run. In the near future, surfaces with complicated curvatures will be inspected by novel modular robot systems consisting of individual modules of linear axes and rotational axes. (orig.) [de

  9. In-service inspection techniques

    International Nuclear Information System (INIS)

    Backfisch, W.; Zipser, R.R.

    1980-01-01

    The owner of a nuclear power plant (NPP) is obligated and interested to maintain - by regular maintenance and in-service inspections - the operational safety and availability of the plant for the subsequent operating period in a condition, as is specified as the basis of the erection and the last operational permits. In-service inspections are performed to verify the operational safety, and maintenance work is performed to guarantee the availability. Below, the typical in-service inspections of a light-water reactor NPP (operated on a pressurized-water reactor or on a boiling-water reactor) are described with details and examples of typical inspections, especially of recurrent performance tests of the systems. (orig./RW)

  10. Classification Technique for Ultrasonic Weld Inspection Signals using a Neural Network based on 2-dimensional fourier Transform and Principle Component Analysis

    International Nuclear Information System (INIS)

    Kim, Jae Joon

    2004-01-01

    Neural network-based signal classification systems are increasingly used in the analysis of large volumes of data obtained in NDE applications. Ultrasonic inspection methods on the other hand are commonly used in the nondestructive evaluation of welds to detect flaws. An important characteristic of ultrasonic inspection is the ability to identify the type of discontinuity that gives rise to a peculiar signal. Standard techniques rely on differences in individual A-scans to classify the signals. This paper proposes an ultrasonic signal classification technique based on the information tying in the neighboring signals. The approach is based on a 2-dimensional Fourier transform and the principal component analysis to generate a reduced dimensional feature vector for classification. Results of applying the technique to data obtained from the inspection of actual steel welds are presented

  11. Computed Radiography: An Innovative Inspection Technique

    International Nuclear Information System (INIS)

    Klein, William A.; Councill, Donald L.

    2002-01-01

    Florida Power and Light Company's (FPL) Nuclear Division combined two diverse technologies to create an innovative inspection technique, Computed Radiography, that improves personnel safety and unit reliability while reducing inspection costs. This technique was pioneered in the medical field and applied in the Nuclear Division initially to detect piping degradation due to flow-accelerated corrosion. Component degradation can be detected by this additional technique. This approach permits FPL to reduce inspection costs, perform on line examinations (no generation curtailment), and to maintain or improve both personnel safety and unit reliability. Computed Radiography is a very versatile tool capable of other uses: - improving the external corrosion program by permitting inspections underneath insulation, and - diagnosing system and component problems such as valve positions, without the need to shutdown or disassemble the component. (authors)

  12. Optical inspection techniques for security instrumentation

    Science.gov (United States)

    van Renesse, Rudolf L.

    1996-03-01

    This paper reviews four optical inspection systems, in which development TNO Institute of Applied Physics was involved: (1) intaglio scanning and recognition, (2) banknote quality inspection, (3) visualization and reading of a finger pattern, and (4) 3DAS authentication. (1) Intaglio is reserved for high security printing. It renders a tactile relief that can be recognized by a laser scanning technique. This technique is applied by various national banks to detect counterfeit banknotes returning from circulation. A new system is proposed that will detect intaglio on arbitrary wrinkled banknotes. (2) A banknote fitness inspection system (BFIS) that inspects banknotes in specularly reflected light is described. As modern banknotes are provided increasingly with reflective security foils, a new system is proposed that inspects banknotes in specular and diffuse reflection, as well as in transmission. (3) An alternative visualization method for visualization of finger patterns is described, employing a reflective elastomer. A CD scanning system reads the finger patterns. (4) A nonwoven structure has two advantageous properties for card authentication: a random structure which renders each few square millimeters of the pattern uniqueness (identification) and a 3D structure which makes it virtually impossible to be counterfeited (authentication). Both properties are inspected by an extremely simple lenseless reader.

  13. Establishment of effective maintenance method based on the superior inspection technique for the deteriorating hot laboratory exhaust stack

    International Nuclear Information System (INIS)

    Mizukoshi, Yasutaka; Yasu, Tetsunori

    2012-06-01

    The Materials Monitoring Facility is equipped with an exhaust stack to emit air from a controlled area (the hot laboratory) into the atmosphere. Cracks and exfoliation have been observed for the surface of the exhaust stack, which is made of reinforced concrete and was constructed on the seacoast about 25 years ago, so exposed to a salt-corrosive condition. In order to get details of the present condition of the exhaust stack, an inspection was carried out using an electromagnetic wave radar method and chloride content method. Cracks and exfoliation were observed for the whole stack surface, especially for high positions. Moreover, salt damage was observed for the outer surface of the exhaust stack, and it was estimated that the infiltration of the chloride content was about 17 mm. Based on this detailed inspection of the exhaust stack, maintenance and repair work were carried out. (author)

  14. Advanced Inspection and Repair Welding Techniques for SCC Countermeasures

    International Nuclear Information System (INIS)

    Takagi, T.; Nishimoto, K.; Uchimoto, T.

    2012-01-01

    Feasibility studies of advanced inspection and repair welding techniques were conducted in the framework of the Nuclear and Industry Safety Agency of Japan (NISA) project on the enhancement of ageing management and maintenance of NPPs. In this paper, features of NDE methods investigated in the projects, main results of research activities and prospect of nickel based alloy weld inspection are discussed. We also make a review for the integrity and reliability evaluation techniques for repair welding of ageing plants which were intensively investigated in view of regulatory criteria, in NISA project. (author)

  15. An effective technique for the software requirements analysis of NPP safety-critical systems, based on software inspection, requirements traceability, and formal specification

    International Nuclear Information System (INIS)

    Koo, Seo Ryong; Seong, Poong Hyun; Yoo, Junbeom; Cha, Sung Deok; Yoo, Yeong Jae

    2005-01-01

    A thorough requirements analysis is indispensable for developing and implementing safety-critical software systems such as nuclear power plant (NPP) software systems because a single error in the requirements can generate serious software faults. However, it is very difficult to completely analyze system requirements. In this paper, an effective technique for the software requirements analysis is suggested. For requirements verification and validation (V and V) tasks, our technique uses software inspection, requirement traceability, and formal specification with structural decomposition. Software inspection and requirements traceability analysis are widely considered the most effective software V and V methods. Although formal methods are also considered an effective V and V activity, they are difficult to use properly in the nuclear fields as well as in other fields because of their mathematical nature. In this work, we propose an integrated environment (IE) approach for requirements, which is an integrated approach that enables easy inspection by combining requirement traceability and effective use of a formal method. The paper also introduces computer-aided tools for supporting IE approach for requirements. Called the nuclear software inspection support and requirements traceability (NuSISRT), the tool incorporates software inspection, requirement traceability, and formal specification capabilities. We designed the NuSISRT to partially automate software inspection and analysis of requirement traceability. In addition, for the formal specification and analysis, we used the formal requirements specification and analysis tool for nuclear engineering (NuSRS)

  16. Advanced inspection and repair techniques for primary side components

    International Nuclear Information System (INIS)

    Elm, Ralph

    1998-01-01

    The availability of nuclear power plant mainly depends on the components of the Nuclear Steam Supply System (NSSS) such as reactor pressure vessel, core internals and steam generators. The last decade has been characterized by intensive inspection and repair work on PWR steam generators. In the future, it can be expected, that the inspection of the reactor pressure vessel and the inspection and repair of its internals, in both PWR and BWR will be one of the challenges for the nuclear community. Due to this challenge, new, advanced inspection and repair techniques for the vital primary side components have been developed and applied, taking into account such issues as: use of reliable and fast inspection methods, repair of affected components instead of costly replacement, reduction of outage time compared to conventional methods, minimized radiation exposure, acceptable costs. This paper reflects on advanced inspection and repair techniques such as: Baffle Former Bolt inspection and replacement, Barrel Former Bolt inspection and replacement, Mechanized UT and visual inspection of reactor pressure vessels, Steam Generator repair by advanced sleeving technology. The techniques described have been successfully applied in nuclear power plants and improved the operation performance of the components and the NPP. (author). 6 figs

  17. Application of ultrasonic inspection technique for crack depth sizing on nickel based alloy weld. Part 3. Establishment of UT procedure for crack depth sizing by phased array UT

    International Nuclear Information System (INIS)

    Hirasawa, Taiji; Okada, Hisao; Fukutomi, Hiroyuki

    2012-01-01

    Recently, it is reported that the primary water stress corrosion cracking (PWSCC) was occurred at the nickel based alloy weld components such as steam generator safe end weld, reactor vessel safe end weld, and so on, in PWR. Defect detection and sizing is important in order to ensure the reliable operation and life extension of nuclear power plants. In the reactor vessel safe end weld, it was impossible to measure crack depth of PWSCC. The crack was detected in the axial direction of the safe end weld. Furthermore, the crack had some features such as shallow, large aspect ratio (ratio of crack depth and length), sharp geometry of crack tip, and so on. Therefore, development and improvement of defect detection and sizing capabilities for ultrasonic testing (UT) is required. Phased array technique was applied to nickel based alloy weld specimen with SCC cracks. From the experimental results, good accuracy of crack depth sizing by phased array UT for the inside inspection was shown. From these results, UT procedure for crack depth sizing was verified. Therefore, effectiveness of phased array UT for crack depth sizing in the nickel based alloy welds was shown. (author)

  18. Proposal for inclusion of the risk based inspection technique in Regulatory Standard NR 13; Proposta de inclusao da tecnica de inspecao baseada em risco na Norma Regulamentadora NR 13

    Energy Technology Data Exchange (ETDEWEB)

    Esteves, Vinicius Teixeira; Lima, Marco Aurelio Oliveira [Det Norske Veritas Ltda. (DNV), Rio de Janeiro, RJ (Brazil)

    2012-07-01

    In Brazil, the Regulatory Standard n. 13 (NR 13) establishes requirements for the inspection of boilers and pressure vessels which has main objective of preventing accidents with these types of equipment. Additionally, it has the Risk-Based Inspection (RBI) technique as an effective way to manage the mechanical integrity of various types of static mechanical equipment by through an inspection planning based on the risk factor. In this study, it is being proposed to include the RBI technique, in the NR 13, for the planning and definition of periods for the safety inspection of boilers and pressure vessels in order to promote an increase in the operational safety in process industries in Brazil. In this study it was carried out a critical analysis of NR 13 and RBI, and beyond that a bibliographic research of various international documents that relate the operational safety of pressurized equipment with the inspection activity, and the acceptability of RBI by governments, agencies and organizations around the world. It is considered that the inclusion and formal acceptance of RBI technique in the NR 13 must be accompanied by a rigorous control to avoid the 'trivialization' of its use and ensure the implementation rational, efficient and reliable. Finally, it was developed and suggested basic elements and minimum requirements to be inserted in the NR 13, to be attended, in order mandatory, by the companies that choose the implementation and use of the RBI technique as a tool for the planning of safety inspection of boilers and pressure vessels. It is concluded that the formal acceptance of the RBI technique in the NR 13 could aggregate much value to this standard, with regard to the prevention of accidents involving boilers or pressure vessels, and provide a technological jump to the companies that make use of RBI technique in Brazil. (author)

  19. Optimized inspection techniques and structural analysis in lifetime management

    International Nuclear Information System (INIS)

    Aguado, M.T.; Marcelles, I.

    1993-01-01

    Preservation of the option of extending the service lifetime of a nuclear power plant beyond its normal design lifetime requires correct remaining lifetime management from the very beginning of plant operation. The methodology used in plant remaining lifetime management is essentially based on the use of standard inspections, surveillance and monitoring programs and calculations, such as thermal-stress and fracture mechanics analysis. The inspection techniques should be continuously optimized, in order to be able to detect and dimension existing defects with the highest possible degree of accuracy. The information obtained during the inspection is combined with the historical data of the components: design, quality, operation, maintenance, and transients, and with the results of destructive testing, fracture mechanics and thermal fatigue analysis. These data are used to estimate the remaining lifetime of nuclear power plant components, systems and structures with the highest degree possible of accuracy. The use of this methodology allows component repairs and replacements to be reduced or avoided and increases the safety levels and availability of the nuclear power plant. Use of this strategy avoids the need for heavy investments at the end of the licensing period

  20. Engineers find climbing techniques work well for dam inspections

    Energy Technology Data Exchange (ETDEWEB)

    O`Shea, M.; Graves, A. [Bureau of Reclamation, Denver, CO (United States)

    1996-10-01

    Climbing techniques adopted by the Bureau of Reclamation to inspect previously inaccessible or difficult to reach features at dams are described. Following the failure of the steel radial-arm gate at Folsom Dam, engineers mounted an effort to reach and inspect the dam`s seven other spillway gates. This close-up examination was performed to: (1) determine the condition of these gates; and (2) gather clues about the failure of the one gate. The access techniques described involved mountaineering techniques, as opposed to high scaling techniques, performed with dynamic and static nylon kermantle ropes.

  1. 37Ar monitoring techniques and on-site inspection system

    International Nuclear Information System (INIS)

    Duan Rongliang; Chen Yinliang; Li Wei; Wang Hongxia; Hao Fanhua

    2001-01-01

    37 Ar is separated, purified and extracted from air sample with a low temperature gas-solid chromatographic purifying method, prepared into a radioactive measurement source and its radioactivity is measured with a proportional counter. Based on the monitoring result, a judgement can be made if an nuclear explosion event has happened recently in a spectabilis area. A series of element techniques that are associated the monitoring of the trace element 37 Ar have been investigated and developed. Those techniques include leaked gas sampling, 37 Ar separation and purification, 37 Ar radioactivity measurement and the on-site inspection of 37 Ar. An advanced 37 Ar monitoring method has been developed, with which 200 liters of air can be treated in 2 hours with sensitivity of 0.01 Bq/L for 37 Ar radioactivity measurement. A practical 37 Ar On-site Inspection system has been developed. This research work may provide technical and equipment support for the verification protection, verification supervision and CTBT verification

  2. Reliability of surface inspection techniques for pressurized components

    International Nuclear Information System (INIS)

    Kauppinen, P.; Sillanpaeae, J.

    1991-01-01

    In the Nordtest NDT-programme (1984 - 1988) the detection of flaws by surface inspection methods has been studied. In the round-robin exercise, 133 test pieces have been inspected by 32 inspectors in Denmark, Finland, Norway and Sweden. From the results, the detectability of defects by magnetic particle and liquid-penetrant testing and the influence of materials and techniques used are evaluated. (author)

  3. Development of ultrasonic immersion inspection technique for spent fuel canisters

    International Nuclear Information System (INIS)

    Schankula, J.J.

    1982-07-01

    This report summarizes ultrasonic nondestructive testing development for metal matrix supported spent fuel disposal canisters. The work has concentated in two areas: inspection for lack of bond at the shell/matrix interface and inspection for voids in the matrix. The capabilities and limitations of these techniques have been fully established. Unbonded areas as small as 4 mm in diameter and voids 6 mm in diameter, 25 mm deep in the matrix, can readily be detected

  4. Defect sizing using automated ultrasonic inspection techniques at RNL

    International Nuclear Information System (INIS)

    Rogerson, A.; Highmore, P.J.; Poulter, L.N.J.

    1983-10-01

    RNL has developed and applied automated wide-beam pulse-echo and time-of-flight techniques with synthetic aperture processing for sizing defects in clad thick-section weldments and nozzle corner regions. These techniques were amongst those used in the four test plate inspections making up the UKAEA Defect Detection Trials. In this report a critical appraisal is given of the sizing procedures adopted by RNL in these inspections. Several factors influencing sizing accuracy are discussed and results from particular defects highlighted. The time-of-flight technique with colour graphics data display is shown to be highly effective in imaging near-vertical buried defects and underclad defects of height greater than 5 mm. Early characterisation of any identified defect from its ultrasonic response under pulse-echo inspection is seen as a desirable aid to the selection of an appropriate advanced sizing technique for buried defects. (author)

  5. Knowledge-Based Inspection Capabilities

    National Research Council Canada - National Science Library

    Marrano, Lance R; Grussing, Michael N

    2006-01-01

    ... does not present a compelling safety hazard. Abandoning certain inspection programs to reduce costs is not a viable alternative, however, because that could degrade real property investments, soldier quality of life, and mission-readiness...

  6. Development of Inspection Technique for Socket Weld of Small Bore Piping in Nuclear Power Plant

    International Nuclear Information System (INIS)

    Yoon, Byungsik; Kim, Yongsik; Lee, Jeongseok

    2013-01-01

    The losses incurred by unplanned shutdowns are significant; consequently, early crack initiation and crack detection, including the detection of fillet weld manufacturing defects, is of the utmost importance. Current inspection techniques are not capable of reliably inspecting socket welds; therefore, new approaches are needed. The new technique must be sensitive to socket weld cracking, which usually initiates from the root, in order to detect the cracking during the early failure phase. In 2008, Kori unit 3 experienced leakage from the drain line socket weld of a steam generator. From this experience, KHNP enforced a management program to focus on enhancing the reliability of small bore socket weld piping inspections. Currently, conventional manual ultrasonic inspection techniques are used to detect service induced fatigue cracks. But there was uncertainty on manual ultrasonic inspection because of limited access to the welds and difficulties with contact between the ultrasonic probe and the OD surface of small bore piping. In this study, phased array ultrasonic inspection techniques are applied to increase inspection speed and reliability. Additionally a manually encoded scanner has been developed to enhance contact conditions and maintain constant signal quality. A phased array UT technique and system was developed to inspect small bore socket welds. The experimental results show all artificial flaws in the specimen were detected and measured. These experimental results show, that the newly developed inspection system, has improved the reliability and speed of small bore socket weld inspection. Based on these results, future works shall focus on additional experiments, with more realistic flaw responses. By applying this technique to the field, we expect that it can improve the integrity of small bore piping in nuclear power plants

  7. Risk-based methodology for USNRC inspections

    International Nuclear Information System (INIS)

    Wong, S.M.; Holahan, G.M.; Chung, J.W.; Johnson, M.R.

    1995-01-01

    This paper describes the development and trial applications of a risk-based methodology to enhance the inspection processes for US nuclear power plants. Objectives of risk-based methods to complement prescriptive engineering approaches in US Nuclear Regulatory Commission (USNRC) inspection programs are presented. Insights from time-dependent risk profiles of plant configurational from Individual Plant Evaluation (IPE) studies were integrated to develop a framework for optimizing inspection efforts in NRC regulatory initiatives. Lessons learned from NRC pilot applications of the risk-based methodology for evaluation of the effectiveness of operational risk management programs at US nuclear power plant sites are also discussed

  8. Simulation tools for industrial applications of phased array inspection techniques

    International Nuclear Information System (INIS)

    Mahaut, St.; Roy, O.; Chatillon, S.; Calmon, P.

    2001-01-01

    Ultrasonic phased arrays techniques have been developed at the French Atomic Energy Commission in order to improve defects characterization and adaptability to various inspection configuration (complex geometry specimen). Such transducers allow 'standard' techniques - adjustable beam-steering and focusing -, or more 'advanced' techniques - self-focusing on defects for instance -. To estimate the performances of those techniques, models have been developed, which allows to compute the ultrasonic field radiated by an arbitrary phased array transducer through any complex specimen, and to predict the ultrasonic response of various defects inspected with a known beam. Both modeling applications are gathered in the Civa software, dedicated to NDT expertise. The use of those complementary models allows to evaluate the ability of a phased array to steer and focus the ultrasonic beam, and therefore its relevancy to detect and characterize defects. These models are specifically developed to give accurate solutions to realistic inspection applications. This paper briefly describes the CIVA models, and presents some applications dedicated to the inspection of complex specimen containing various defects with a phased array used to steer and focus the beam. Defect detection and characterization performances are discussed for the various configurations. Some experimental validation of both models are also presented. (authors)

  9. Statistical sampling techniques as applied to OSE inspections

    International Nuclear Information System (INIS)

    Davis, J.J.; Cote, R.W.

    1987-01-01

    The need has been recognized for statistically valid methods for gathering information during OSE inspections; and for interpretation of results, both from performance testing and from records reviews, interviews, etc. Battelle Columbus Division, under contract to DOE OSE has performed and is continuing to perform work in the area of statistical methodology for OSE inspections. This paper represents some of the sampling methodology currently being developed for use during OSE inspections. Topics include population definition, sample size requirements, level of confidence and practical logistical constraints associated with the conduct of an inspection based on random sampling. Sequential sampling schemes and sampling from finite populations are also discussed. The methods described are applicable to various data gathering activities, ranging from the sampling and examination of classified documents to the sampling of Protective Force security inspectors for skill testing

  10. Review of inspection of Torness reactor internals using remote techniques

    International Nuclear Information System (INIS)

    Dynan, J.

    1993-01-01

    Inspection of reactor internals is increasingly being achieved by deployment of cameras into areas of sometimes high radiation fields using manipulators. The manipulators have been developed over a number of years and from a variety of sources and those provided at Torness can maybe be seen to be the state of the art development of such machines for AGRS. Torness and Heysham 2 reactors were specifically designed for inspection using remote techniques and special facilities have been provided for this purpose. This paper is written by an operator and not a manipulator specialist and is intended to show what the operator needs versus what the designer gave him. (author)

  11. Development of FBR visual inspection technique in sodium

    International Nuclear Information System (INIS)

    Suzuki, T.; Nagai, S.; Shioyama, T.; Sato, M.; Karasawa, H.; Maruyama, F.; Ota, S.; Hida, T.; Kai, M.

    1995-01-01

    Because the reactor vessel of Fast Breeder Reactor is filled with opaque liquid sodium, it is expected to develop an acoustic visual inspection technique in sodium. The acoustic 3 dimensional image processing technique and the elemental parts of the visual inspection equipment in sodium have been developed at the first stage of the in-sodium visual inspection technique development. The cross correlation processing has been applied to improve the S/N ratio in the acoustic echo that are deteriorated by wetting in sodium and the low sensitivity that are also deteriorated by rather smaller diameter to integrate the high density multiple acoustic sensors. The improvement of S/N ratio has been realized by the cross correlation between acoustic echo data that is reflected from the objects and M-series continuous wave that is transmitted from the acoustic transducer. The high speed parallel processing circuits, in which DSPs (Digital Signal Processors) are included, have been developed to realize high speed processing by employing (the circuits connected to) each of sensors in parallel. Synthetic Aperture Focussing Technique (SAFT) has been applied to the acoustic 3-dimensional image processing. The amounts of ellipsoids must be drawn into the 3-dimensional memory to compose the 3-dimensional image by SAFT. Then, a high performance work-station has been employed to deal with enormous data to compose the acoustic 3 dimensional image. Motors and cables, which can be operated under the condition of high-temperature and high-radiation environment, have been developed as the parts of the manipulator which will be used for visual inspection equipment in sodium. A prototype drive mechanism consists of the manipulator with three joints and a scanner with an arrayed acoustic sensors which a sweeps in fan-shape mechanically. The manipulatory type prototype drive mechanism and the signal processing device have been developed and tested, and the acoustic 3-dimensional image of pyramid

  12. Luminescence imaging strategies for drone-based PV array inspection

    DEFF Research Database (Denmark)

    Benatto, Gisele Alves dos Reis; Riedel, Nicholas; Mantel, Claire

    2017-01-01

    The goal of this work is to perform outdoor defect detection imaging that will be used in a fast, accurate and automatic drone-based survey system for PV power plants. The imaging development focuses on techniques that do not require electrical contact, permitting automatic drone inspections...

  13. Vibrational Based Inspection Of A Steel Mast

    DEFF Research Database (Denmark)

    Kirkegaard, Poul Henning; Rytter, A.

    1994-01-01

    The aim of this paper is to present the results from a research project concerning vibrational based inspection of a 20 meter high steel mast containing well defined damages. Introductory analyses dealing with among other things evaluation of potential damage indicators and determination of accep......The aim of this paper is to present the results from a research project concerning vibrational based inspection of a 20 meter high steel mast containing well defined damages. Introductory analyses dealing with among other things evaluation of potential damage indicators and determination...

  14. Inspection of an artificial heart by the neutron radiography technique

    International Nuclear Information System (INIS)

    Pugliesi, R.; Geraldo, L.P.; Andrade, M.L.G.; Menezes, M.O.; Pereira, M.A.S.; Maizato, M.J.S.

    1999-01-01

    The neutron radiography technique was employed to inspect an artificial heart prototype which is being developed to provide blood circulation for patients expecting heart transplant surgery. The radiographs have been obtained by the direct method with a gadolinium converter screen along with the double coated Kodak-AA emulsion film. The artificial heart consists of a flexible plastic membrane located inside a welded metallic cavity, which is employed for blood pumping purposes. The main objective of the present inspection was to identify possible damages in this plastic membrane, produced during the welding process of the metallic cavity. The obtained radiographs were digitized as well as analysed in a PC and the improved images clearly identify several damages in the plastic membrane, suggesting changes in the welding process

  15. Inspection of an artificial heart by the neutron radiography technique

    CERN Document Server

    Pugliesi, R; Andrade, M L G; Menezes, M O; Pereira, M A S; Maizato, M J S

    1999-01-01

    The neutron radiography technique was employed to inspect an artificial heart prototype which is being developed to provide blood circulation for patients expecting heart transplant surgery. The radiographs have been obtained by the direct method with a gadolinium converter screen along with the double coated Kodak-AA emulsion film. The artificial heart consists of a flexible plastic membrane located inside a welded metallic cavity, which is employed for blood pumping purposes. The main objective of the present inspection was to identify possible damages in this plastic membrane, produced during the welding process of the metallic cavity. The obtained radiographs were digitized as well as analysed in a PC and the improved images clearly identify several damages in the plastic membrane, suggesting changes in the welding process.

  16. IEC-based neutron generator for security inspection system

    International Nuclear Information System (INIS)

    Miley, G.H.; Wu, L.; Kim, H.J.

    2005-01-01

    Use of a combined X-ray and neutron source for security inspections based on Inertial Electrostatic Confinement (IEC) fusion is discussed. Current inspection systems typically use X-ray techniques, but thermal neutron analysis (TNA) and fast neutron analysis (FNA), allow expanded detection of certain types of explosives. The integrated unit proposed here uses three separate IEC sources producing 14 and 2.45 MeV neutrons plus soft X-rays. This combination allows multiple detection methods with the composite signal analysis being done by a fuzzy logic system, significantly reducing false signals. (author)

  17. Multispectral fluorescence imaging techniques for nondestructive food safety inspection

    Science.gov (United States)

    Kim, Moon S.; Lefcourt, Alan M.; Chen, Yud-Ren

    2004-03-01

    The use of spectral sensing has gained acceptance as a rapid means for nondestructive inspection of postharvest food produce. Current technologies generally use color or a single wavelength camera technology. The applicability and sensitivity of these techniques can be expanded through the use of multiple wavelengths. Reflectance in the Vis/NIR is the prevalent spectral technique. Fluorescence, compared to reflectance, is regarded as a more sensitive technique due to its dynamic responses to subtle changes in biological entities. Our laboratory has been exploring fluorescence as a potential means for detection of quality and wholesomeness of food products. Applications of fluorescence sensing require an understanding of the spectral characteristics emanating from constituents and potential contaminants. A number of factors affecting fluorescence emission characteristics are discussed. Because of relatively low fluorescence quantum yield from biological samples, a system with a powerful pulse light source such as a laser coupled with a gated detection device is used to harvest fluorescence, in the presence of ambient light. Several fluorescence sensor platforms developed in our laboratory, including hyperspectral imaging, and laser-induced fluorescence (LIF) and steady-state fluorescence imaging systems with multispectral capabilities are presented. We demonstrate the potential uses of recently developed fluorescence imaging platforms in food safety inspection of apples contaminated with animal feces.

  18. Application of the ultrasonic phased array technique to alloy 182 weld inspection in PWR

    International Nuclear Information System (INIS)

    Hsiao, Chu Chung; Shie, Namg Chian; Chu, Shyr Liang; Lee, Sou See; Toung, Jean Chung; Su, Liang Chun; Yang, Hai Ming

    2006-01-01

    Cracks were found in nickel-based welds frequently in some nuclear power plants. The development of inspection technique capability of finding these cracks is thus in great demand. The difficulties of inspection and evaluation for nickel-based welds include ultrasonic reflection of interface of dissimilar materials, ultrasonic distortion of anisotropic microstructure, and signal-to-noise ratio reduction of coarse grain. In this study, an Alloy 182 mock-up with the same size and material properties as in the field is designed and fabricated. The Alloy 182 mock-up specimen contains various cracks and notches for calibration. Phased array UT and other ultrasonic inspection techniques are used in this study. Based on the experiment results, the phased array probe with 2D dual crystals and low frequency (1.5MHz) longitudinal wave is found to perform well. Finally, phased array ultrasonic testing technique has been approved to be an effectively nondestructive test method for DMW with real size testing block involved. Typically, phased array probe can generate sharp tip diffraction signal and thus reliable and accurate result can be obtained for sizing the defect. Furthermore, phased array probe can also generate various angles and focal lengths and thus combinatorial effect can be achieved for several traditional probes. With a full understanding of the beam behavior and an optimized delay laws, the phased away ultrasonic technique integrated with an automatic scanner will achieve not only to save scanning time but also to reduce the amount of radiation exposure on field inspection.

  19. Surface Casting Defects Inspection Using Vision System and Neural Network Techniques

    Directory of Open Access Journals (Sweden)

    Świłło S.J.

    2013-12-01

    Full Text Available The paper presents a vision based approach and neural network techniques in surface defects inspection and categorization. Depending on part design and processing techniques, castings may develop surface discontinuities such as cracks and pores that greatly influence the material’s properties Since the human visual inspection for the surface is slow and expensive, a computer vision system is an alternative solution for the online inspection. The authors present the developed vision system uses an advanced image processing algorithm based on modified Laplacian of Gaussian edge detection method and advanced lighting system. The defect inspection algorithm consists of several parameters that allow the user to specify the sensitivity level at which he can accept the defects in the casting. In addition to the developed image processing algorithm and vision system apparatus, an advanced learning process has been developed, based on neural network techniques. Finally, as an example three groups of defects were investigated demonstrates automatic selection and categorization of the measured defects, such as blowholes, shrinkage porosity and shrinkage cavity.

  20. Procedure for the determination of gap and base ground surface configurations beneath the bottom plate of storage tanks using neutron gauging inspection techniques : including radiation safety procedure and emergency procedure

    International Nuclear Information System (INIS)

    Jaafar Abdullah

    1993-01-01

    The procedure is intended for the neutron gauging inspection of gap between the bottom plate and the foundation of bulk storage tanks, which potentially exhibit uneven sinking of the bottom plate and the foundation. Its describes the requirements for the performance of neutron back scattered inspection techniques (or radiometric non-destructive evaluation techniques), using an isotopic neutron source associated with neutron detecting systems, to detect and size the gap between the bottom plate and the foundations as well as to quantify the presence of hydrogenous materials (e.g. oil or water) underneath the bottom plate. This procedure is not only outline the requirements for the neutron gauging inspection, but also describes the requirements which shall be taken into account in formulating the radiation safety and emergency procedures for the neutron gauging inspection works

  1. Nuclear reactor vessel surface inspecting technique applying electric resistance probe

    International Nuclear Information System (INIS)

    Yamaguchi, T.; Enami, K.; Yoshioka, M.

    1975-01-01

    A new technique for inspecting the inner surface of the PWR type nuclear reactor vessel by use of an electric resistance probe is introduced, centering on a data processing system. This system is composed of a mini-computer, a system typewriter, an interface unit, a D-A converter and controller, and X-Y recorder and others. Its functions are judging flaws and making flaw detection maps. In order to judge flaws by flaw detection signals, three kinds of flaw judging methods have been developed. In case there is a flaw, its position and depth are calculated and listed on the system typewriter. The flaw detection maps are expressed in four kinds of modes and they are displayed on the X-Y recorder. (auth.)

  2. Use of artificial intelligence techniques for visual inspection systems prototyping. Application to magnetoscopy

    International Nuclear Information System (INIS)

    Pallas, Christophe

    1987-01-01

    The automation of visual inspection is a complex task that requires collaboration between experts, for example inspection specialist, vision specialist. on-line operators. Solving such problems through prototyping promotes this collaboration: the use of a non specific programming environment allows rapid, concrete checking of method validity, thus leading incrementally to the final system. In this context, artificial intelligence techniques permit easy, extensible, and modular design of the prototype, together with heuristic solution building. We define and achieve the SPOR prototyping environment, based on object-oriented programming and rules-basis managing. The feasibility and the validity of an heuristic method for automated visual inspection in fluoroscopy have been proved through prototyping in SPOR. (author) [fr

  3. In service inspection of pipes based on risk methods

    International Nuclear Information System (INIS)

    Mendoza G, G.; Viais J, J.; Carmona C, M.

    2006-01-01

    The politics of the Nuclear Regulatory Commission (by its initials in English NRC) of the United States of America on the use of the Probabilistic Safety Analysis (PSA) in activities of nuclear regulation it foments the use of this analysis technique to improve the decisions making, to reduce the unnecessary work in maintenance aspects, inspection and tests and to improve the regulatory efficiency. The inspection programs in service (ISI by its initials in English) developed by the American Society of Mechanical Engineers (by its initials in English ASME) it has been the one primary mechanism to prove the mechanical equipment in plants of nuclear energy, these programs indeed have been carried out in plants of nuclear energy by more of two decades. Their purpose is to identify the conditions, such as indications of cracks that are precursory of flights and ruptures which violate the integrity principles of the pressure frontier. The inspection in service activities include ultrasonic tests, surface tests and penetrating liquids test, also activities that include the scaffolds construction, removal of insulations and welding polishing. The inspections in service every 18 months during the times outside of service are executed. One of the objectives is to lower the costs of the inspections during the times outside of service and to reduce the exposure to the radiation by part of the personnel during these times out for inspections, while it is increased or it maintains the personnel's safety and the reliability. As part of the methodology a pipe segment is selected for which a fault in any point has the same consequences, being calculated the fault probability of the tube using the dimensions of the segment. In this work the inspection in service methodology is applied based on risk to an aspersion system of low pressure of the Laguna Verde Nucleo electric Central. For this system a reduction in the number of welding to inspect of 103 to only 15 is obtained

  4. Wall thinning inspection technique for large-diameter piping using guided wave

    International Nuclear Information System (INIS)

    Miki, Masahiro; Nagashima, Yoshiaki; Endou, Masao; Kodaira, Kojiro; Maniwa, Kazuhiko

    2009-01-01

    Guided wave inspection technique is effective for detecting defects like corrosion in piping, because it can perform long range inspection. It is possible to expect this inspection as a method that leads to the decrease of the inspection process and its cost, because the incidental work can be reduced. Especially, the contraction effect of the inspection work is extensive in large-diameter piping inspection. In this paper, we introduce the guided wave inspection system to large-diameter piping. The feature is a guided wave sensor that can freely transform according to the curvature of inspection object, and portable inspection equipment. We discuss the result of detection examination for artificial wall-thinning in large-diameter piping using this system. (author)

  5. Risk-based inspection in the context of nuclear power plants

    International Nuclear Information System (INIS)

    Soares, Wellington A.; Vasconcelos, Vanderley de; Rabello, Emerson G.

    2015-01-01

    Nuclear power plant owners have to consider several aspects like safety, availability, costs and radiation exposure during operation of nuclear power plants. They also need to demonstrate to regulatory bodies that risk assessment and inspection planning processes are being implemented in effective and appropriate manner. Risk-Based Inspection (RBI) is a methodology that, unlike time-based inspection, involves a quantitative assessment of both failure probability and consequence associated with each safety-related item. A correctly implemented RBI program classifies individual equipment by its risks and prioritizes inspection efforts based on this classification. While in traditional deterministic approach, the inspection frequencies are constant, in the RBI approach the inspection interval for each item depends on the risk level. Regularly, inspection intervals from RBI result in risk levels lower or equal than deterministic inspection intervals. According to the literature, RBI solutions improve integrity and reduce costs through a more effective inspection. Risk-Informed In-service Inspection (RI-ISI) is the equivalent term used in the nuclear area. Its use in nuclear power plants around world is briefly reviewed in this paper. Identification of practice methodologies for performing risk-based analyses presented in this paper can help both Brazilian nuclear power plant operator and regulatory body in evaluating the RI-ISI technique feasibility as a tool for optimizing inspections within nuclear plants. (author)

  6. Risk-based inspection in the context of nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Soares, Wellington A.; Vasconcelos, Vanderley de; Rabello, Emerson G., E-mail: soaresw@cdtn.br, E-mail: vasconv@cdtn.br, E-mail: egr@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2015-07-01

    Nuclear power plant owners have to consider several aspects like safety, availability, costs and radiation exposure during operation of nuclear power plants. They also need to demonstrate to regulatory bodies that risk assessment and inspection planning processes are being implemented in effective and appropriate manner. Risk-Based Inspection (RBI) is a methodology that, unlike time-based inspection, involves a quantitative assessment of both failure probability and consequence associated with each safety-related item. A correctly implemented RBI program classifies individual equipment by its risks and prioritizes inspection efforts based on this classification. While in traditional deterministic approach, the inspection frequencies are constant, in the RBI approach the inspection interval for each item depends on the risk level. Regularly, inspection intervals from RBI result in risk levels lower or equal than deterministic inspection intervals. According to the literature, RBI solutions improve integrity and reduce costs through a more effective inspection. Risk-Informed In-service Inspection (RI-ISI) is the equivalent term used in the nuclear area. Its use in nuclear power plants around world is briefly reviewed in this paper. Identification of practice methodologies for performing risk-based analyses presented in this paper can help both Brazilian nuclear power plant operator and regulatory body in evaluating the RI-ISI technique feasibility as a tool for optimizing inspections within nuclear plants. (author)

  7. Reliability-Based Inspection Planning for Structural Systems

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard

    1993-01-01

    A general model for reliability-based optimal inspection and repair strategies for structural systems is described. The total expected costs in the design lifetime is minimized with the number of inspections, the inspection times and efforts as decision variables. The equivalence of this model...... with a preposterior analysis from statistical decision theory is discussed. It is described how information obtained by an inspection can be used in a repair decision. Stochastic models for inspection, measurement and repair actions are presented. The general model is applied for inspection and repair planning...

  8. Performance-based inspection and maintenance strategies

    International Nuclear Information System (INIS)

    Vesely, W.E.

    1995-01-01

    Performance-based inspection and maintenance strategies utilize measures of equipment performance to help guide inspection and maintenance activities. A relevant measure of performance for safety system components is component unavailability. The component unavailability can also be input into a plant risk model such as a Probabilistic Risk Assessment (PRA) to determine the associated plant risk performance. Based on the present and projected unavailability performance, or the present and projected risk performance, the effectiveness of current maintenance activities can be evaluated and this information can be used to plan future maintenance activities. A significant amount of information other than downtimes or failure times is collected or can be collected when an inspection or maintenance is conducted which can be used to estimate the component unavailability. This information generally involves observations on the condition or state of the component or component piecepart. The information can be detailed such as the amount of corrosion buildup or can be general such as the general state of the component described as ' high degradation', ' moderate degradation', or ' low degradation'. Much of the information collected in maintenance logs is qualitative and fuzzy. As part of an NRC Research program on performance-based engineering modeling, approaches have been developed to apply Fuzzy Set Theory to information collected on the state of the component to determine the implied component or component piecepart unavailability. Demonstrations of the applications of Fuzzy Set Theory are presented utilizing information from plant maintenance logs. The demonstrations show the power of Fuzzy Set Theory in translating engineering information to reliability and risk implications

  9. Verification of Remote Inspection Techniques for Reactor Internal Structures of Liquid Metal Reactor

    International Nuclear Information System (INIS)

    Joo, Young Sang; Lee, Jae Han

    2007-02-01

    The reactor internal structures and components of a liquid metal reactor (LMR) are submerged in hot sodium of reactor vessel. The division 3 of ASME code section XI specifies the visual inspection as major in-service inspection (ISI) methods of reactor internal structures and components. Reactor internals of LMR can not be visually examined due to opaque liquid sodium. The under-sodium viewing techniques using an ultrasonic wave should be applied for the visual inspection of reactor internals. Recently, an ultrasonic waveguide sensor with a strip plate has been developed for an application to the under-sodium inspection. In this study, visualization technique, ranging technique and monitoring technique have been suggested for the remote inspection of reactor internals by using the waveguide sensor. The feasibility of these remote inspection techniques using ultrasonic waveguide sensor has been evaluated by an experimental verification

  10. Application of ultrasonic phased array technique for inspection of stud bolts in nuclear reactor vessel

    International Nuclear Information System (INIS)

    Choi, Sang Woo; Lee, Joon Ho; Park, Min Su; Cho, Youn Ho; Park, Moon Ho

    2004-01-01

    The stud bolt is one of crucial parts for safety of reactor vessels in nuclear power plants. Cracks initiation and propagation were reported in stud bolts using closure of reactor vessel and head. Stud bolts are inspected by ultrasonic technique during overhaul periodically for the prevention of stud bolt failure and radioactive leakage from nuclear reactor. In conventional ultrasonic testing for inspection of stud bolts, crack was detected by using shadow effect. It take too much time to inspect stud bolt by using conventional ultrasonic technique. In addition, there were numerous spurious signal reflected from every thread. In this study, the advanced ultrasonic phased array technique was introduced for inspect stud bolts. The phased array technique provide fast inspection and high detectability of defects. There are sector scanning and linear scanning method in phased array technique, and these scanning methods were applied to inspect stud bolt and detectability was investigated.

  11. Verification of Remote Inspection Techniques for Reactor Internal Structures of Liquid Metal Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Joo, Young Sang; Lee, Jae Han

    2007-02-15

    The reactor internal structures and components of a liquid metal reactor (LMR) are submerged in hot sodium of reactor vessel. The division 3 of ASME code section XI specifies the visual inspection as major in-service inspection (ISI) methods of reactor internal structures and components. Reactor internals of LMR can not be visually examined due to opaque liquid sodium. The under-sodium viewing techniques using an ultrasonic wave should be applied for the visual inspection of reactor internals. Recently, an ultrasonic waveguide sensor with a strip plate has been developed for an application to the under-sodium inspection. In this study, visualization technique, ranging technique and monitoring technique have been suggested for the remote inspection of reactor internals by using the waveguide sensor. The feasibility of these remote inspection techniques using ultrasonic waveguide sensor has been evaluated by an experimental verification.

  12. The evidence base for school inspection frameworks

    NARCIS (Netherlands)

    Scheerens, Jaap; Ehren, Melanie Catharina Margaretha; Ehren, Melanie C.M.

    2016-01-01

    This chapter describes how Inspectorates of Education operationalize different inspection goals (control, improvement, and liaison) in their inspection indicator frameworks. The chapter provides an overview and examples of the indicators used across a number of countries and how these are

  13. Coke drums inspection and evaluation using stress and strain analysis techniques

    Energy Technology Data Exchange (ETDEWEB)

    Haraguchi, Marcio Issamu [Tricom Tecnologia e Servicos de Manutencao Industrial Ltda., Piquete, SP (Brazil); Samman, Mahmod [Houston Engineering Solutions, Houston, TX (United States); Tinoco, Ediberto Bastos; Marangone, Fabio de Castro; Silva, Hezio Rosa da; Barcelos, Gustavo de Carvalho [Petroleo Brasileiro S.A. (PETROBRAS), Rio de Janeiro, RJ (Brazil)

    2012-07-01

    Coke drums deform due to a complex combination of mechanical and thermal cyclic stresses. Bulges have progressive behavior and represent the main maintenance problem related to these drums. Bulge failure typically result in through-wall cracks, leaks, and sometimes fires. Such failures generally do not represent a great risk to personnel. Repairs needed to maintain reliability of these vessels might require extensive interruption to operation which in turn considerably impacts the profitability of the unit. Therefore the condition, progression and severity of these bulges should be closely monitored. Coke drums can be inspected during turnaround with 3D Laser Scanning and Remote Visual Inspection (RVI) tools, resulting in a detailed dimensional and visual evaluation of the internal surface. A typical project has some goals: inspect the equipment to generate maintenance or inspection recommendations, comparison with previous results and baseline data. Until recently, coke drum structural analysis has been traditionally performed analyzing Stress Concentration Factors (SCF) thought Finite Element Analysis methods; however this technique has some serious technical and practical limitations. To avoid these shortcomings, the new strain analysis technique PSI (Plastic Strain Index) was developed. This method which is based on API 579/ ASME FFS standard failure limit represents the state of the art of coke drum bulging severity assessment has an excellent correlation with failure history. (author)

  14. Risk based inspection for atmospheric storage tank

    Science.gov (United States)

    Nugroho, Agus; Haryadi, Gunawan Dwi; Ismail, Rifky; Kim, Seon Jin

    2016-04-01

    Corrosion is an attack that occurs on a metallic material as a result of environment's reaction.Thus, it causes atmospheric storage tank's leakage, material loss, environmental pollution, equipment failure and affects the age of process equipment then finally financial damage. Corrosion risk measurement becomesa vital part of Asset Management at the plant for operating any aging asset.This paper provides six case studies dealing with high speed diesel atmospheric storage tank parts at a power plant. A summary of the basic principles and procedures of corrosion risk analysis and RBI applicable to the Process Industries were discussed prior to the study. Semi quantitative method based onAPI 58I Base-Resource Document was employed. The risk associated with corrosion on the equipment in terms of its likelihood and its consequences were discussed. The corrosion risk analysis outcome used to formulate Risk Based Inspection (RBI) method that should be a part of the atmospheric storage tank operation at the plant. RBI gives more concern to inspection resources which are mostly on `High Risk' and `Medium Risk' criteria and less on `Low Risk' shell. Risk categories of the evaluated equipment were illustrated through case study analysis outcome.

  15. Rail inspection system based on iGPS

    Science.gov (United States)

    Fu, Xiaoyan; Wang, Mulan; Wen, Xiuping

    2018-05-01

    Track parameters include gauge, super elevation, cross level and so on, which could be calculated through the three-dimensional coordinates of the track. The rail inspection system based on iGPS (indoor/infrared GPS) was composed of base station, receiver, rail inspection frame, wireless communication unit, display and control unit and data processing unit. With the continuous movement of the inspection frame, the system could accurately inspect the coordinates of rail; realize the intelligent detection and precision measurement. According to principle of angle intersection measurement, the inspection model was structured, and detection process was given.

  16. Risk based inspection experience from the European chemical- and petrochemical industries

    International Nuclear Information System (INIS)

    Kristensen, Hans; Jeppesen, Leif; Larsen, Bjarne; Kim, Na Yon

    2001-01-01

    As an inspection vendor with 60 years of experience and with more than 25 years of experience as manufacturer of the Automated Ultrasonic NDT systems, the P-scan systems, FORCE Institute is continuously analysing the market for NDT. This is done to assure that both the equipment product line and the service mix provided by FORCE Institute are meeting the requirements from the industry today and in the future. The concept of Risk Based Inspection Programmes were adopted early by the offshore industry and has in the recent years been adopted by many other industries as a reliable and cost efficient way of maintaining a production facility. A Risk/Reliability Based Inspection Programme is a 'living organism' that constantly needs information if it shall be of any value and NDT information is only one type of information that is required. The NDT information required is normally related to corrosion/base material information and weld integrity information. NDT as an integrated part of a plants maintenance system is, in Europe, currently influenced by the following tendencies which all are related to 'Risk Based Inspection': · Increased use of Base-Line Inspections · Reduction in the use of repeated inspections(qualitative- instead of quantitative Inspections). · Inspection results are fed directly into the plant maintenance system. · Fitness-for-Purpose acceptance criteria instead of conventional acceptance criteria. As repeatability and accuracy is a key issue for the data, automated ultrasonic inspection is increasingly used as an alternative to manual ultrasonic inspection, but due to the physical size of most automated ultrasonic inspection systems the gain in productivity has not been as significant as the gain in repeatability and accuracy. In this paper some of FORCE Institute's practical experiences with examinations carried out in connection with Risk Based Inspection is used to illustrate the above described tendencies. Not only examples using automated

  17. Generic Reliability-Based Inspection Planning for Fatigue Sensitive Details

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Straub, Daniel; Faber, Michael Havbro

    2005-01-01

    of fatigue sensitive details in fixed offshore steel jacket platforms and FPSO ship structures. Inspection and maintenance activities are planned such that code based requirements to the safety of personnel and environment for the considered structure are fulfilled and at the same time such that the overall......The generic approach for planning of in-service NDT inspections is extended to cover the case where the fatigue load is modified during the design lifetime of the structure. Generic reliability-based inspection planning has been developed as a practical approach to perform inspection planning...... expected costs for design, inspections, repairs and failures are minimized. The method is based on the assumption of “no-finds” of cracks during inspections. Each fatigue sensitive detail is categorized according to their type of details (SN curves), FDF values, RSR values, inspection, repair and failure...

  18. Automobile inspection system based on wireless communication

    Science.gov (United States)

    Miao, Changyun; Ye, Chunqing

    2010-07-01

    This paper aims to research the Automobile Inspection System based on Wireless Communication, and suggests an overall design scheme which uses GPS for speed detection and Bluetooth and GPRS for communication. The communication between PDA and PC was realized by means of GPRS and TCP/IP; and the hardware circuit and software for detection terminal were devised by means of JINOU-3264 Bluetooth Module after analyzing the Bluetooth and its communication protocol. According to the results of debugging test, this system accomplished GPRS based data communication and management as well as the real-time detection on auto safety performance parameters in crash test via PC, whereby the need for mobility and reliability was met and the efficiency and level of detection was improved.

  19. Inspection of Buildings in Rio de Janeiro-Brazil: Proving the greater tendency of corrosion at the base of reinforced concrete columns using potential corrosion technique

    OpenAIRE

    Marcelo Henrique Farias de Medeiros

    2013-01-01

    Monitoring the corrosion of steel embedded in concrete is a way to assess the degradation of civil structures. A technique used for this is the measurement of corrosion potential, which includes the use of a reference electrode, connected to a high input impedance voltmeter. There are many factors influencing the measurement of corrosion potential, such as: degree of concrete moisture content, the oxygen access, existence of micro fissures, chloride penetration, carbonation and concrete cover...

  20. Vibrational Based Inspection of Civil Engineering Structures

    DEFF Research Database (Denmark)

    Rytter, Anders

    at the University of Aalborg from 1988 to 1991. Secondly, a research project, In-Field Vibration Based Inspection of Civil Engineering Structures, which has been performed as a pilot project by the Consulting Engineers Rambøll, Hannemann and Højlund in cooperation with the department of Building Technology......The thesis has been written in relation to two different research projects. Firstly, an offshore test programme, Integrated Experimental/Numerical Analysis of the Dynamic behavior of offshore structures, which was performed at the department of Building Technology and Structural Engineering...... and Structural Engineering at the University of Aalborg since the beginning of 1992. Both projects have been supported by the Danish Technical Research Council. Further, the first mentioned project was supported by the Danish Energy Agency. Their financial support is gratefully acknowledged....

  1. Risk-based inspection of nuclear power plants

    International Nuclear Information System (INIS)

    Masopust, R.

    1995-01-01

    A multidiscipline research programme was developed in the USA to establish risk-based inspections for NPP structures and equipment components. Based on this US research effort, the risk-based procedure for developing inspection guidelines for NPPs is described. The procedure includes the definition of systems, qualitative risk assessment, qualitative risk analysis and development of the inspection programme. The method, when adopted and modified, is recommended also for risk-based inspections of structures and equipment of WWER-type NPPs. A pilot application of the method to unit 1 of the Surry NPP is summarized. (Z.S.) 1 tab., 1 fig., 5 refs

  2. Use of mountaineering rope climbing techniques vs custom-built platforms for penstock inspections

    Energy Technology Data Exchange (ETDEWEB)

    Bechai, M.; Dmochowski, A.; Conlon, J.; Bhat, P.D. [Ontario Hydro, Toronto, ON (Canada); Henderson, D. [Remote Access Technology Inc., Dartmouth, NS (Canada)

    1998-12-01

    Ontario Hydro has developed an inspection and maintenance strategy that requires periodic inspections of their ageing penstocks. The utility has 149 operating penstocks distributed throughout the province. Ontario Hydro experienced problems ranging from minor deterioration to major failures requiring immediate and costly shut-down of entire stations. Three levels of the inspection and maintenance strategy are described. These are a routine external inspections, periodic internal and external inspections, and detailed inspection and assessment. Detailed inspection requires full access to all areas of the penstock, inside and outside, with detailed testing and analysis. Rope access techniques have been used successfully and cost effectively to gain access for close up observation and tactile contact allowing for evaluation and testing. Minor, quick repairs can also be carried out. It was noted that specially designed platforms will still be needed when extensive repairs and maintenance is required. 2 refs., 1 tab., 3 figs.

  3. Risk Based Inspection Planning of Ageing Structures

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Ersdal, Gerhard

    2008-01-01

    . Different approaches for updating inspection plans for older installations are considered in order to achieve decreased inspection intervals as the structure are ageing. The most promising method consists in increasing the rate of defects / crack initiation at the end of the expected lifetime. Different...

  4. The evidence base for school inspection frameworks

    NARCIS (Netherlands)

    Scheerens, Jaap; Ehren, Melanie Catharina Margaretha

    2015-01-01

    This article describes how Inspectorates of Education operationalize different inspection goals (control, improvement, liaison) in their inspection indicator frameworks. The paper provides an overview and examples of the indicators used across a number of countries and how these are incorporated in

  5. Ultrasonic recording and display techniques for the inspection of nuclear power plant

    International Nuclear Information System (INIS)

    Ely, R.W.; Hall, G.D.; Johnson, A.; Pascoe, P.T.

    1985-01-01

    This paper describes four systems: MDU, PURDIE, LAURA and DRUID, under development as ultrasonic recording and display techniques for the inspection of nuclear power plant. The MDU system plots either plan or sectional views of the component under test onto a bistable storage screen. PURDIE is a system based around a video cassette recorder which has been modified to record ultrasonic A-scan waveforms and probe positional information. MDU and PURDIE are portable systems, for use under difficult site conditions. They may be manufactured in quantity to satisfy the demanding inspection programmes of nuclear power stations. LAURA is a desk top replay system for the video cassette tapes produced on site by PURDIE. DRUID is a digital desk top replay/display system incorporating a high resolution colour graphics terminal and therefore offering more flexibility and improved display formats. The systems are compatible with each other and some component units are directly interchangeable between the various systems

  6. Nondestructive inspection of chemical warfare based on API-TOF

    International Nuclear Information System (INIS)

    Wang Xinhua; Zheng Pu; He Tie; An Li; Yang Jie; Fan Yu

    2013-01-01

    Background: Real-time, fast, accurate, nondestructive inspection (NDI) and quantitative analysis for chemical warfare are very imperative for chemical defense, anti-terror and nation security. Purpose: Associated Particles Technique (APT)/Neutron Time of Flight (TOF) has been developed for non-invasive inspection of sealed containers with chemical warfare agents. Methods: A prototype equipment for chemical warfare is consisted of an APT neutron generator with a 3×3 matrix of semiconductor detectors of associated alpha-particles, the shielding protection of neutron and gamma-ray, arrayed NaI(Tl)-based detectors of gamma-rays, fully-digital data acquisition electronics, data analysis, decision-making software, support platform and remote control system. Inelastic scattering gamma-ray pulse height spectra of sarin, VX, mustard gas and adamsite induced by 14-MeV neutron are measured. The energies of these gamma rays are used to identify the inelastic scattering elements, and the intensities of the peaks at these energies are used to reveal their concentrations. Results: The characteristic peaks of inelastic scattering gamma-ray pulse height spectra show that the prototype equipment can fast and accurately inspect chemical warfare. Conclusion: The equipment can be used to detect not only chemical warfare agents but also other hazardous materials, such as chemical/toxic/drug materials, if their chemical composition is in any way different from that of the surrounding materials. (authors)

  7. On qualification of TOFD technique for austenitic stainless steel welds inspection

    Energy Technology Data Exchange (ETDEWEB)

    Martinez-Ona, R. [Tecnatom, San Sebastian de los Reyes (Spain); Viggianiello, S.; Bleuze, A. [Metalscan, Saint-Remy (France)

    2006-07-01

    Time of Flight Diffraction (TOFD) technique is gaining ground as a solid method for detection and sizing of defects. It has been reported that TOFD technique provides good results on the inspection of fine grain steels. However, there are few results regarding the application and performance of this technique on austenitic stainless steels. A big challenge of these inspections is the coarse grain structure that produces low signal to noise ratio and may mask the diffraction signals. Appropriate transducer design, selection of technique parameters and analysis tools could overcome the actual difficulties. In this paper, the main design aspects and parameters of the TOFD technique for austenitic steels are presented. It follows the description of qualification tests carried out to validate the technique for inspecting stainless steels welds. To conclude, discussion of results from actual inspections is shown. (orig.)

  8. Noncontact sheet resistance measurement technique for wafer inspection

    Science.gov (United States)

    Kempa, Krzysztof; Rommel, J. Martin; Litovsky, Roman; Becla, Peter; Lojek, Bohumil; Bryson, Frank; Blake, Julian

    1995-12-01

    A new technique, MICROTHERM, has been developed for noncontact sheet resistance measurements of semiconductor wafers. It is based on the application of microwave energy to the wafer, and simultaneous detection of the infrared radiation resulting from ohmic heating. The pattern of the emitted radiation corresponds to the sheet resistance distribution across the wafer. This method is nondestructive, noncontact, and allows for measurements of very small areas (several square microns) of the wafer.

  9. Evaluation of techniques for inspection and diagnostics of HWR pressure tubes

    International Nuclear Information System (INIS)

    Choi, Jong-Ho

    2008-01-01

    Efficient and accurate inspection and diagnostic techniques for various reactor components and systems, especially pressure tubes for Heavy Water Reactors (HWRs), are an important factor in assuring reliable and safe plant operation. To foster international collaboration in the efficient and safe use of nuclear power, the IAEA conducted a Coordinated Research Project (CRP) on Inter-comparison of Techniques for HWR Pressure Tube Inspection and Diagnostics. The objective of the CRP was to inter-compare inspection and diagnostic techniques, in use and being developed, for structural integrity assessment of HWR pressure tubes. During the first phase of the CRP, participants investigated the capability of different techniques to detect and characterize flaws. During the second phase, participants collaborated to determine the hydrogen concentration and to detect and characterize hydride blisters in zirconium alloy pressure tubes. Eight organizations from six countries, which operate HWRs, have participated in this CRP, Most of the techniques examined are well established and many of them are regularly used during in-service inspection of pressure tubes. The inter-comparison of these techniques provides a platform for identifying a particular technique (or a set of techniques), which is more accurate and reliable as compared to others for a specified task. The CRP also witnessed some new methodologies, which can be implemented on in-service inspection tools. These new techniques could complement the existing ones to overcome their limitations, thereby improving the reliability and accuracy of in-service inspection. This CRP also identified future areas of research and development. (author)

  10. Benefits of Risk Based Inspection Planning for Offshore Structures

    DEFF Research Database (Denmark)

    Straub, D.M.; Goyet, J.; Sørensen, John Dalsgaard

    2006-01-01

    The economical benefits of applying risk-based inspection planning (RBI) for offshore structures subject to fatigue are evaluated based on experiences from past industrial projects. To this end, the factors influencing the cost of inspection, repair and failure of structures are discussed......, the financial benefit of RBI is assessed....

  11. Heat Exchanger Tube Inspection of Nuclear Power Plants using IRIS Technique

    International Nuclear Information System (INIS)

    Yoon, Byung Sik; Yang, Seung Han; Song, Seok Yoon; Kim, Yong Sik; Lee, Hee Jong

    2005-01-01

    Inspection of heat exchange tubing include steam generator of nuclear power plant mostly performed with eddy current method. Recently, various inspection technique is available such as remote field eddy current, flux leakage and ultrasonic methods. Each of these techniques has its merits and limitations. Electromagnetic techniques are very useful to locate areas of concern but sizing is hard because of the difficult interpretation of an electric signature. On the other hand, ultrasonic methods are very accurate in measuring wall loss damage, and are reliable for detecting cracks. Additionally ultrasound methods is not affected by support plates or tube sheets and variation of electrical conductivity or permeability. Ultrasound data is also easier to analyze since the data displayed is generally the remaining wall thickness. It should be emphasized that ultrasound is an important tool for sizing defects in tubing. In addition, it can be used in situations where eddy current or remote field eddy current is not reliable, or as a flaw assessment tool to supplement the electromagnetic data. The need to develop specialized ultrasonic tools for tubing inspection was necessary considering the limitations of electromagnetic techniques to some common inspection problems. These problems the sizing of wall loss in carbon steel tubes near the tube sheet or support plate, sizing internal erosion damage, and crack detection. This paper will present an IRIS(Internal Rotating Inspection System) ultrasonic tube inspection technique for heat exchanger tubing in nuclear power plant and verify inspection reliability for artificial flaw embedded to condenser tube

  12. Surface inspection technique with an eddy current testing array probe

    International Nuclear Information System (INIS)

    Nishimizu, Akira; Endo, Hisashi; Tooma, Masahiro; Otani, Kenichi; Ouchi, Hirofumi; Yoshida, Isao; Nonaka, Yoshio

    2010-01-01

    An eddy current testing (ECT) system has been developed for inspecting weld surfaces of components in the reactor pressure vessel of nuclear plants. The system can be applied to curved surfaces with an ECT array probe, it can discriminate flaws from other signal factors by using a combination of arrayed coils signal-phase. The system is applied to a mock-up of core internal components and the signal discrimination using the signal-phase clearly separated flaw and noise signals. (author)

  13. Effectiveness and reliability of US inservice inspection techniques

    International Nuclear Information System (INIS)

    Doctor, S.R.; Becker, F.L.; Selby, G.P.

    1982-01-01

    The work presented is from an ongoing program directed toward measuring the effectiveness and reliability of inservice inspection (ISI) of light water reactor systems (primary piping and pressure vessel). Extensive round robin and parametric evaluations have been conducted in 10 in. Sch. 80 stainless steel as well as centrifugally cast stainless steel and clad ferritic main coolant pipe welds. Results from these measurements will be viewed in relationship to US regulations and ASME Section XI Code requirements. 6 figures

  14. Synthetic Aperture Focusing Technique in Ultrasonic Inspection of Coarse Grained Materials

    Energy Technology Data Exchange (ETDEWEB)

    Stepinski, Tadeusz (Uppsala Univ., Signals and Systems, Box 528, SE-751 20 Uppsala (Sweden))

    2007-12-15

    Experience from the ultrasonic inspection of nuclear power plants has shown that large focused transducers are relatively effective in suppressing grain (structure) noise. Operation of a large focused transducer can be thought of as an integration (coherent summation) of individual beams reflected from the target and received by individual points at the transducer surface. Synthetic aperture focusing technique (SAFT), in its simplest version mimics an acoustic lens used for focusing beams at a desired point in the region of interest. Thus, SAFT should be able to suppress the grain noise in the similar way as the focused transducer does. This report presents the results of investigation of SAFT algorithms applied for post-processing of ultrasonic data acquired in inspection of coarse grained metals. The performance of SAFT in terms of its spatial (cross-range) resolution and grain noise suppression is studied. The evaluation is made based on the experimental data obtained from the ultrasonic inspection of test specimens with artificial defects (side drilled holes). SAFT algorithms for both contact and immersion mode are introduced and experimentally verified

  15. Inspection Based Evaluation of a Danish Road Bridge

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle

    In this paper it is shown how an inspection-based evaluation of a Danish road bridge may be performed using the BRIDGE1 and BRIDGE2 bridge management systems produced within the EC-supported research programme "Assessment of Performance and Optimal Strategies for Inspection and Maintenance...

  16. Vision Based Autonomous Robotic Control for Advanced Inspection and Repair

    Science.gov (United States)

    Wehner, Walter S.

    2014-01-01

    The advanced inspection system is an autonomous control and analysis system that improves the inspection and remediation operations for ground and surface systems. It uses optical imaging technology with intelligent computer vision algorithms to analyze physical features of the real-world environment to make decisions and learn from experience. The advanced inspection system plans to control a robotic manipulator arm, an unmanned ground vehicle and cameras remotely, automatically and autonomously. There are many computer vision, image processing and machine learning techniques available as open source for using vision as a sensory feedback in decision-making and autonomous robotic movement. My responsibilities for the advanced inspection system are to create a software architecture that integrates and provides a framework for all the different subsystem components; identify open-source algorithms and techniques; and integrate robot hardware.

  17. Application of reliability techniques to prioritize BWR [boiling water reactor] recirculation loop welds for in-service inspection

    International Nuclear Information System (INIS)

    Holman, G.S.

    1989-12-01

    In January 1988 the US Nuclear Regulatory Commission issued Generic Letter 88-01 together with NUREG-0313, Revision 2, ''Technical Report on Material Selection and Processing Guidelines for BWR Coolant Pressure Boundary Piping,'' to implement NRC long-range plans for addressing the problem of stress corrosion cracking in boiling water reactor piping. NUREG-0313 presents guidelines for categorizing BWR pipe welds according to their SCC condition (e.g., presence of known cracks, implementation of measures for mitigating SCC) as well as recommended inspection schedules (e.g., percentage of welds inspected, inspection frequency) for each weld category. NUREG-0313 does not, however, specify individual welds to be inspected. To address this issue, the Lawrence Livermore National Laboratory developed two recommended inspection samples for welds in a typical BWR recirculation loop. Using a probabilistic fracture mechanics model, LLNL prioritized loop welds on the basis of estimated leak probabilities. The results of this evaluation indicate that riser welds and bypass welds should be given priority attention over other welds. Larger-diameter welds as a group can be considered of secondary importance compared to riser and bypass welds. A ''blind'' comparison between the probability-based inspection samples and data from actual field inspections indicated that the probabilistic analysis generally captured the welds which the field inspections identified as warranting repair or replacement. Discrepancies between the field data and the analytic results can likely be attributed to simplifying assumptions made in the analysis. The overall agreement between analysis and field experience suggests that reliability techniques -- when combined with historical experience -- represent a sound technical basis on which to define meaningful weld inspection programs. 13 refs., 8 figs., 5 tabs

  18. Ultrasonic inspection of composite hydrogen reservoirs using frequency diversity techniques

    International Nuclear Information System (INIS)

    Zellouf, D.; Goyette, J.; Massicotte, D.; Bose, T.K.

    2000-01-01

    During their service, cryogenic tanks are subjected to both hydrostatic and hygrothermic stresses. This can have as a consequence the initiation of the propagation of cracks within the structure of the material. Nevertheless, the analysis of ultrasonic signals collected during the inspection of composite materials must be dealt with carefully because of the presence of a strong background noise due to the reinforcement. This background noise results mostly from the interferences between the waves diffracted on the reinforcement. The target echo and the noise in which it is embedded both have the same frequency bandwidth. Thus we cannot use conventional linear filters to improve the signal-to-noise ratio

  19. Study of a risk-based piping inspection guideline system.

    Science.gov (United States)

    Tien, Shiaw-Wen; Hwang, Wen-Tsung; Tsai, Chih-Hung

    2007-02-01

    A risk-based inspection system and a piping inspection guideline model were developed in this study. The research procedure consists of two parts--the building of a risk-based inspection model for piping and the construction of a risk-based piping inspection guideline model. Field visits at the plant were conducted to develop the risk-based inspection and strategic analysis system. A knowledge-based model had been built in accordance with international standards and local government regulations, and the rational unified process was applied for reducing the discrepancy in the development of the models. The models had been designed to analyze damage factors, damage models, and potential damage positions of piping in the petrochemical plants. The purpose of this study was to provide inspection-related personnel with the optimal planning tools for piping inspections, hence, to enable effective predictions of potential piping risks and to enhance the better degree of safety in plant operations that the petrochemical industries can be expected to achieve. A risk analysis was conducted on the piping system of a petrochemical plant. The outcome indicated that most of the risks resulted from a small number of pipelines.

  20. Label inspection of approximate cylinder based on adverse cylinder panorama

    Science.gov (United States)

    Lin, Jianping; Liao, Qingmin; He, Bei; Shi, Chenbo

    2013-12-01

    This paper presents a machine vision system for automated label inspection, with the goal to reduce labor cost and ensure consistent product quality. Firstly, the images captured from each single-camera are distorted, since the inspection object is approximate cylindrical. Therefore, this paper proposes an algorithm based on adverse cylinder projection, where label images are rectified by distortion compensation. Secondly, to overcome the limited field of viewing for each single-camera, our method novelly combines images of all single-cameras and build a panorama for label inspection. Thirdly, considering the shake of production lines and error of electronic signal, we design the real-time image registration to calculate offsets between the template and inspected images. Experimental results demonstrate that our system is accurate, real-time and can be applied for numerous real- time inspections of approximate cylinders.

  1. Ergodicity of forward times of the renewal process in a block-based inspection model using the delay time concept

    International Nuclear Information System (INIS)

    Wang Wenbin; Banjevic, Dragan

    2012-01-01

    The delay time concept and the techniques developed for modelling and optimising plant inspection practice have been reported in many papers and case studies. For a system subject to a few major failure modes, component based delay time models have been developed under the assumptions of an age-based inspection policy. An age-based inspection assumes that an inspection is scheduled according to the age of the component, and if there is a failure renewal, the next inspection is always, say τ times, from the time of the failure renewal. This applies to certain cases, particularly important plant items where the time since the last renewal or inspection is a key to schedule the next inspection service. However, in most cases, the inspection service is not scheduled according to the need of a particular component, rather it is scheduled according to a fixed calendar time regardless whether the component being inspected was just renewed or not. This policy is called a block-based inspection which has the advantage of easy planning and is particularly useful for plant items which are part of a larger system to be inspected. If a block-based inspection policy is used, the time to failure since the last inspection prior to the failure for a particular item is a random variable. This time is called the forward time in this paper. To optimise the inspection interval for block-based inspections, the usual criterion functions such as expected cost or down time per unit time depend on the distribution of this forward time. We report in this paper the development of a theoretical proof that a limiting distribution for such a forward time exists if certain conditions are met. We also propose a recursive algorithm for determining such a limiting distribution. A numerical example is presented to demonstrate the existence of the limiting distribution.

  2. Guidelines for risk-based fish inspection

    OpenAIRE

    2015-01-01

    Fish and fishery products are nutritious and healthy and are an important source of food and livelihood for many millions of people worldwide. Fish inspection is concerned with ensuring that the consumer has access to safe and nutritious fish and fish products, whether the fish is from domestic sources of supply, imported or to be exported to consumers in another country. The present guidelines will assist fish inspectors to carry out these responsibilities--Publisher's description.

  3. Two new NDT techniques for inspection of containment welds beneath coatings

    International Nuclear Information System (INIS)

    Fitzpatrick, G.L.; Thome, D.K.

    1991-06-01

    Two new nondestructive testing methods were evaluated for inspection of containment welds beneath coatings, including magneto-optic imaging and Hall effect measurements. Traditional inspection methods, including magnetic particle inspection, are unsatisfactory in the nuclear containment environment coatings must be removed to provide reliable results. This creates radioactive waste, potential airborne contamination, and prolonged radiation exposure to inspection personnel. The new methods offer great improvement because of increased sensitivity and rapid scanning capability. Results obtained during Phase 1 demonstrated that magneto-optic imaging methods offered good detection of cracking in welded carbon steel samples, even through paint. Direct, real-time images were obtained with this technique in a video format ideal for complete documentation of the full inspection. A new method for rapidly inducing the required magnetic fields for inspection was also demonstrated and offers the potential for eliminating bulky, high current power supplies or magnetic yokes. Results obtained with the Hall effect were not as promising as they were on aluminum, due to electrical interference problems and variables biasing caused by residual magnetic fields in the parts. The technique may still be useful for inspecting tight spaces not accessible with magneto-optic imaging devices, but will require significant development. 13 refs., 18 figs

  4. Risk-Based School Inspections: Impact of Targeted Inspection Approaches on Dutch Secondary Schools

    Science.gov (United States)

    Ehren, Melanie C.; Shackleton, Nichola

    2016-01-01

    In most countries, publicly funded schools are held accountable to one inspectorate and are judged against agreed national standards. Many inspectorates of education have recently moved towards more proportional risk-based inspection models, targeting high-risk schools for visits, while schools with satisfactory student attainment levels are…

  5. Optimal Risk-Based Inspection Planning for Offshore Wind Turbines

    DEFF Research Database (Denmark)

    Rangel-Ramirez, Jose G.; Sørensen, John Dalsgaard

    2008-01-01

    , inspection and maintenance activities are developed. This paper considers aspects of inspection and maintenance planning of fatigue prone details in jacket and tripod types of wind turbine support structures. Based oil risk-based inspection planning methods used for oil & gas installations, a framework......Wind turbines for electricity production have increased significantly the last years both in production capability and size. This development is expected to continue also in the coining years. The Support structure for offshore wind turbines is typically a steel structure consisting of a tower...... for optimal inspection and maintenance planning of offshore wind turbines is presented. Special aspects for offshore wind turbines are considered: usually the wind loading are dominating the wave loading, wake effects in wind farms are important and the reliability level is typically significantly lower than...

  6. Risk-based inspection--Development of guidelines

    International Nuclear Information System (INIS)

    1993-07-01

    Effective inservice inspection programs can play a significant role in minimizing equipment and structural failures. Most of the current inservice inspection programs for light water reactor (LWR) nuclear power plant components are based on experience and engineers' qualitative judgment. These programs include only an implicit consideration of risk, which combines the probability of failure of a component under its operation and loading conditions and the consequences of such failure, if it occurs. This document recommends appropriate methods for establishing a risk-based inspection program for LWR nuclear power plant components. The process has been built from a general methodology (Volume 1) and has been expanded to involve five major steps: defining the system; evaluating qualitative risk assessment results; using this and information from plant probabilistic risk assessments to perform a quantitative risk analysis; selecting target failure probabilities; and developing an inspection program for components using economic decision analysis and structural reliability assessment methods

  7. A Study on Techniques for Focusing Circumferential Array Guided Waves for Long Range Inspection of Pipes

    International Nuclear Information System (INIS)

    Kang, To; Kim, Hak Joon; Song, Sung Jin; Cho, Young Do; Lee, Dong Hoon; Cho, Hyun Joon

    2009-01-01

    Ultrasonic guided waves have been widely utilized for long range inspection of structures. Especially, development of array guided waves techniques and its application for long range gas pipe lines(length of from hundreds meters to few km) were getting increased. In this study, focusing algorithm for array guided waves was developed in order to improve long range inspectability and accuracy of the array guided waves techniques for long range inspection of gas pipes, and performance of the developed techniques was verified by experiments using the developed array guided wave system. As a result, S/N ratio of array guided wave signals obtained with the focusing algorithm was increased higher than that of signals without focusing algorithm

  8. Research on automatic inspection technique of real-time radiography for turbine-blade

    International Nuclear Information System (INIS)

    Zhou, Z.G.; Zhao, S.; An, Z.G.

    2004-01-01

    To inspect turbine blade automatically, with a real-time radiographic system based on X-ray flat panel detector, computerized defect extraction technique is studied on the basis of characteristics of turbine blade's digital radiographic images. At first, in the light of a variety of gray-level in a turbine blade's digital radiographic image, it is divided into six subareas. An adaptive median filter is used to smooth defects in each subarea. Then, the filtrated image is subtracted from the raw image and a difference image with flat background and outstanding defects is obtained. After that, thresholding is applied to the difference image and defects in the turbine blade become obvious. Later on, a morphological opening is used to realize noise reduction. In order to ensure the accuracy of defects, a region growing method is adopted to reconstruct the defects. Finally, the feature data of defects are extracted. The comparison between computerized feature extraction results and human interpretation results indicates that the method mentioned above is effective and efficient, which will lay a good foundation for automatic inspection of turbine-blade with X-ray. (author)

  9. Under-Sodium Inspection Techniques for Reactor Internals of KALIMER-600 using Ultrasonic Waveguide Sensor

    International Nuclear Information System (INIS)

    Joo, Young Sang; Kim, Seok Hoon; Lee, Jae Han

    2005-01-01

    KALIMER-600 is a pool type liquid metal reactor (LMR) which is operated with a sodium coolant. The reactor internals of KALIMER-600 are submerged in a liquid sodium pool. As the liquid sodium is opaque to the light, a conventional visual inspection can not be used for observing the internal structures under a sodium condition. An under-sodium viewing (USV) technique using an ultrasonic wave should be applied for the observation of the refueling maneuver and the in-service inspection of the reactor internals. Under-sodium inspection technology utilizing ultrasonic waves has been widely developed for a visualization of the reactor core and internal components of LMR. Immersion sensors and waveguide sensors have been applied to the USV inspection. The immersion sensor has a precise imaging capability, but may have high temperature restrictions and an uncertain life. The waveguide sensor has the advantages of simplicity and reliability, but limited in its movement. The new plate-type waveguide sensor has been developed as a useful alternative to immersion sensors for USV applications. In the viewing and monitoring applications, a beam steering function of a waveguide sensor might be required. A new waveguide sensor and technique are being developed to overcome the limitations of a waveguide ultrasonic sensor. In this study, the under-sodium inspection techniques using the newly developed waveguide sensor for the reactor internal structures of KALIMER-600 is proposed

  10. Phased arrays techniques and split spectrum processing for inspection of thick titanium casting components

    International Nuclear Information System (INIS)

    Banchet, J.; Chahbaz, A.; Sicard, R.; Zellouf, D.E.

    2003-01-01

    In aircraft structures, titanium parts and engine members are critical structural components, and their inspection crucial. However, these structures are very difficult to inspect ultrasonically because of their large grain structure that increases noise drastically. In this work, phased array inspection setups were developed to detected small defects such as simulated inclusions and porosity contained in thick titanium casting blocks, which are frequently used in the aerospace industry. A Cut Spectrum Processing (CSP)-based algorithm was then implemented on the acquired data by employing a set of parallel bandpass filters with different center frequencies. This process led in substantial improvement of the signal to noise ratio and thus, of detectability

  11. A Novel Method of Autonomous Inspection for Transmission Line based on Cable Inspection Robot LiDAR Data

    Directory of Open Access Journals (Sweden)

    Xinyan Qin

    2018-02-01

    Full Text Available With the growth of the national economy, there is increasing demand for electricity, which forces transmission line corridors to become structurally complicated and extend to complex environments (e.g., mountains, forests. It is a great challenge to inspect transmission line in these regions. To address these difficulties, a novel method of autonomous inspection for transmission line is proposed based on cable inspection robot (CIR LiDAR data, which mainly includes two steps: preliminary inspection and autonomous inspection. In preliminary inspection, the position and orientation system (POS data is used for original point cloud dividing, ground point filtering, and structured partition. A hierarchical classification strategy is established to identify the classes and positions of the abnormal points. In autonomous inspection, CIR can autonomously reach the specified points through inspection planning. These inspection targets are imaged with PTZ (pan, tilt, zoom cameras by coordinate transformation. The feasibility and effectiveness of the proposed method are verified by test site experiments and actual line experiments, respectively. The proposed method greatly reduces manpower and improves inspection accuracy, providing a theoretical basis for intelligent inspection of transmission lines in the future.

  12. Value of information-based inspection planning for offshore structures

    DEFF Research Database (Denmark)

    Irman, Arifian Agusta; Thöns, Sebastian; Leira, Bernt J.

    2017-01-01

    with each inspection strategy. A simplified and generic risk-based inspection planning utilizing pre- posterior Bayesian decision analysis had been proposed by Faber et al. [1] and Straub [2]. This paper provides considerations on the theoretical background and a Value of Information analysis......-based inspection planning. The paper will start out with a review of the state-of-art RBI planning procedure based on Bayesian decision theory and its application in offshore structure integrity management. An example of the Value of Information approach is illustrated and it is pointed to further research......Asset integrity and management is an important part of the oil and gas industry especially for existing offshore structures. With declining oil price, the production rate is an important factor to be maintained that makes integrity of the structures one of the main concerns. Reliability based...

  13. Evaluation of piping reliability and failure data for use in risk-based inspections of nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Vasconcelos, V. de; Soares, W.A.; Costa, A.C.L. da; Rabello, E.G.; Marques, R.O., E-mail: vasconv@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2016-07-01

    During operation of industrial facilities, components and systems can deteriorate over time, thus increasing the possibility of accidents. Risk-Based Inspection (RBI) involves inspection planning based on information about risks, through assessing of probability and consequence of failures. In-service inspections are used in nuclear power plants, in order to ensure reliable and safe operation. Traditional deterministic inspection approaches investigate generic degradation mechanisms on all systems. However, operating experience indicates that degradation occurs where there are favorable conditions for developing a specific mechanism. Inspections should be prioritized at these places. Risk-Informed In-service Inspections (RI-ISI) are types of RBI that use Probabilistic Safety Assessment results, increasing reliability and plant safety, and reducing radiation exposure. These assessments use both available generic reliability and failure data, as well as plant specific information. This paper proposes a method for evaluating piping reliability and failure data important for RI-ISI programs, as well as the techniques involved. (author)

  14. Evaluation of piping reliability and failure data for use in risk-based inspections of nuclear power plants

    International Nuclear Information System (INIS)

    Vasconcelos, V. de; Soares, W.A.; Costa, A.C.L. da; Rabello, E.G.; Marques, R.O.

    2016-01-01

    During operation of industrial facilities, components and systems can deteriorate over time, thus increasing the possibility of accidents. Risk-Based Inspection (RBI) involves inspection planning based on information about risks, through assessing of probability and consequence of failures. In-service inspections are used in nuclear power plants, in order to ensure reliable and safe operation. Traditional deterministic inspection approaches investigate generic degradation mechanisms on all systems. However, operating experience indicates that degradation occurs where there are favorable conditions for developing a specific mechanism. Inspections should be prioritized at these places. Risk-Informed In-service Inspections (RI-ISI) are types of RBI that use Probabilistic Safety Assessment results, increasing reliability and plant safety, and reducing radiation exposure. These assessments use both available generic reliability and failure data, as well as plant specific information. This paper proposes a method for evaluating piping reliability and failure data important for RI-ISI programs, as well as the techniques involved. (author)

  15. Nuclear techniques for the inspection of blast furnaces

    International Nuclear Information System (INIS)

    Schweitzer, J. S.; Lanza, R. C.

    1999-01-01

    Carbon hearth wall failures in blast furnaces create safety risks and require a large expense to repair. To avoid failures they are replaced early, incurring costs in wasted hearth wall use. Two non-invasive measurements provide realtime analysis of wall integrity. The two major failure modes are erosion of carbon thickness and iron-filled cracks in the bricks. Measurements of backscattered gamma-ray spectra and thermal neutron decay rate can identify both phenomena. Gamma-ray spectra from a compact Linac beam primarily respond to average carbon thickness. Neutron decay time, using a pulsed neutron source, is sensitive to iron in the carbon volume. Each measurement is sensitive to the other failure made, but the combination permits each phenomenon to be resolved. These techniques can detect a high atomic number and thermal neutron absorption cross section material behind one of low atomic number and thermal neutron absorption cross section

  16. Improvement of testing techniques for inspecting steam turbine rotor in power plant

    International Nuclear Information System (INIS)

    Su, Yeong Shuenn; Wei, Chieng Neng; Wu, Chien Wen; Wu, Yung How

    1997-01-01

    Steam turbine rotor is important to the Utility industry, it degrades over time due to fatigue and corrosion under high temperature and high pressure environment. Periodic inspection is required in the wake of plant annual overhaul to ensure the integrity of turbine rotor. Non-Destructive Testing of turbine rotor is usually performed using magnetic particle testing with wet fluorescent magnetic particle. However, it is very difficult to ensure the reliability of inspection due to the limitation of using one NDT method only. The crack-susceptible areas, such as turbine blade, and blade root have high incidence of stress corrosion cracking, The blade root section is difficult to locate cracks because of the complex geometry which may cause inadequate magnetic field and poor accessibility. Improved inspection practices was developed by our Department, together with remaining life analysis, in maintaining the high availability of steam turbine rotor. The newly-developed inspection system based on the practical study of magnetic field strength distribution, quality of magnetic particle bath and a combination of different NDT methods with Eddy Current Testing using absolute pen-type coil and Visual Testing using reflective mirror to examine the key areas concerned are described. TPC' experience with the well-trained technicians together with the adequate inspection procedure in detecting blade-root flaws are also discussed in the paper. Many of these inspection improvement have been applied in the fields for several times and the inspection reliability has been enhanced substantially. Results are quite encouraging and satisfactory.

  17. Remote Inspection Techniques for Reactor Internals of Liquid Metal Reactor by using Ultrasonic Waveguide Sensor

    International Nuclear Information System (INIS)

    Joo, Young Sang; Kim, Seok Hun; Lee, Jae Han

    2006-02-01

    The primary components such as a reactor core, heat exchangers, pumps and internal structures of a liquid metal reactor (LMR) are submerged in hot sodium of reactor vessel. The division 3 of ASME code section XI specifies the visual inspection and continuous monitoring as major in-service inspection (ISI) methods of reactor internal structures. Reactor core and internal structures of LMR can not be visually examined due to an opaque liquid sodium. The under-sodium viewing and remote inspection techniques by using an ultrasonic wave should be applied for the in-service inspection of reactor internals. The remote inspection techniques using ultrasonic wave have been developed and applied for the visualization and ISI of reactor internals. The under sodium viewing technique has a limitation for the application of LMR due to the high temperature and irradiation environment. In this study, an ultrasonic waveguide sensor with a strip plate has been developed for an application to the under-sodium viewing and remote inspection. The Lamb wave propagation of a waveguide sensor has been analyzed and the zero-order antisymmetric A 0 plate wave was selected as the application mode of the sensor. The A 0 plate wave can be propagated in the dispersive low frequency range by using a liquid wedge clamped to the waveguide. A new technique is presented which is capable of steering the radiation beam angle of a waveguide sensor without a mechanical movement of the sensor assembly. The steering function of the ultrasonic radiation beam can be achieved by a frequency tuning method of the excitation pulse in the dispersive range of the A 0 mode. The technique provides an opportunity to overcome the scanning limitation of a waveguide sensor. The beam steering function has been evaluated by an experimental verification. The ultrasonic C-scanning experiments are performed in water and the feasibility of the ultrasonic waveguide sensor has been verified. The various remote inspection

  18. Evaluation of the feasibility for detecting hidden corrosion damage in multi-layer gusset plates using multiple inspection techniques

    International Nuclear Information System (INIS)

    Cobb, Adam C.; Duffer, Charles E.; Light, Glenn M.

    2014-01-01

    Gusset plates are used to connect the members in truss bridges and they are usually inspected using calipers or conventional thickness measurement ultrasonic testing (UT) devices. The damage mechanism of particular concern in gusset plates is corrosion and the regions most susceptible to corrosion damage are on the gusset interior surface where it intersects the chord, diagonal, and vertical members from water collecting at the interfaces. For heavily loaded gusset plates, one or more shingle plates are used to reinforce the gusset plate, creating a multi-layer structure. While the areas with corrosion damage remain near the members on the gusset plate, the shingle plates cover the gusset plate and greatly limit the surface access to the gusset plate, making UT thickness measurement impractical. Because of the critical nature of the gussets, a viable inspection strategy for multi-layer gusset assemblies must be developed. The premise of this research and development effort was to develop viable, field-deployable inspection approaches for this problem area. This paper presents three separate inspection approaches: two ultrasonic-based techniques and one radiographic approach. Each of these techniques was evaluated on a mock-up specimen provided by the Federal Highway Administration (FHWA) that is representative of gusseted connection from a truss bridge

  19. Evaluation of the feasibility for detecting hidden corrosion damage in multi-layer gusset plates using multiple inspection techniques

    Energy Technology Data Exchange (ETDEWEB)

    Cobb, Adam C.; Duffer, Charles E.; Light, Glenn M. [Southwest Research Institute, 6220 Culebra Road, San Antonio, TX 78238-5166 (United States)

    2014-02-18

    Gusset plates are used to connect the members in truss bridges and they are usually inspected using calipers or conventional thickness measurement ultrasonic testing (UT) devices. The damage mechanism of particular concern in gusset plates is corrosion and the regions most susceptible to corrosion damage are on the gusset interior surface where it intersects the chord, diagonal, and vertical members from water collecting at the interfaces. For heavily loaded gusset plates, one or more shingle plates are used to reinforce the gusset plate, creating a multi-layer structure. While the areas with corrosion damage remain near the members on the gusset plate, the shingle plates cover the gusset plate and greatly limit the surface access to the gusset plate, making UT thickness measurement impractical. Because of the critical nature of the gussets, a viable inspection strategy for multi-layer gusset assemblies must be developed. The premise of this research and development effort was to develop viable, field-deployable inspection approaches for this problem area. This paper presents three separate inspection approaches: two ultrasonic-based techniques and one radiographic approach. Each of these techniques was evaluated on a mock-up specimen provided by the Federal Highway Administration (FHWA) that is representative of gusseted connection from a truss bridge.

  20. Development of ultrasonic inspection technique for crack detection in retaining rings

    International Nuclear Information System (INIS)

    Brook, M.V.

    1990-01-01

    The majority of retaining rings which are currently in service, are composed of a material which is susceptible to stress corrosion when exposed to moisture. Due to the inherent stress levels in the shrunk-on areas, they are particularly susceptible to stress corrosion attack. Therefore, retaining rings require non-destructive examination to avert catastrophic failure. Guidelines for retaining ring inspection issued by EPRI recommend ultrasonic manual and automated methods of inspection for rings in place. Application of the conventional manual method, using S-waves is difficult, and yields unreliable results. Due to the unreliability factor, utilities have been forced to depend upon surface examination methods, such as visual and penetrant techniques. In most instances, a surface exam will necessitate the costly and potentially damaging removal of the rings from the rotor to provide full access to areas of interest. Due to the various complexities of conventional ultrasonic retaining ring inspections, it is essential that the front end ultrasonics (i.e., transducers and techniques) be optimized to produce the best possible examination. For this reason, AMDATA has developed custom transducers and techniques to enhance automated detection capability of flaws in the various suspect areas of retaining rings. When the optimized techniques are applied to generate the best possible raw data, the Intraspect /98 trademark is then used to reliably apply technique, acquire the data and perform post processing evaluations. One of the most promising ultrasonic techniques for retaining ring inspection is creeping waves. This paper investigates the use of creeping waves for retaining ring inspection

  1. Techniques d'inspection par ondes guidees ultrasonores d'assemblages brases dans des reacteurs aeronautiques =

    Science.gov (United States)

    Comot, Pierre

    L'industrie aeronautique, cherche a etudier la possibilite d'utiliser de maniere structurelle des joints brases, dans une optique de reduction de poids et de cout. Le developpement d'une methode d'evaluation rapide, fiable et peu couteuse pour evaluer l'integrite structurelle des joints apparait donc indispensable. La resistance mecanique d'un joint brase dependant principalement de la quantite de phase fragile dans sa microstructure. Les ondes guidees ultrasonores permettent de detecter ce type de phase lorsqu'elles sont couplees a une mesure spatio-temporelle. De plus la nature de ce type d'ondes permet l'inspection de joints ayant des formes complexes. Ce memoire se concentre donc sur le developpement d'une technique basee sur l'utilisation d'ondes guidees ultrasonores pour l'inspection de joints brases a recouvrement d'Inconel 625 avec comme metal d'apport du BNi-2. Dans un premiers temps un modele elements finis du joint a ete utilise pour simuler la propagation des ultrasons et optimiser les parametres d'inspection, la simulation a permis egalement de demontrer la faisabilite de la technique pour la detection de la quantite de phase fragile dans ce type de joints. Les parametres optimises sont la forme de signal d'excitation, sa frequence centrale et la direction d'excitation. Les simulations ont montre que l'energie de l'onde ultrasonore transmise a travers le joint aussi bien que celle reflechie, toutes deux extraites des courbes de dispersion, etaient proportionnelles a la quantite de phase fragile presente dans le joint et donc cette methode permet d'identifier la presence ou non d'une phase fragile dans ce type de joint. Ensuite des experimentations ont ete menees sur trois echantillons typiques presentant differentes quantites de phase fragile dans le joint, pour obtenir ce type d'echantillons differents temps de brasage ont ete utilises (1, 60 et 180 min). Pour cela un banc d'essai automatise a ete developpe permettant d'effectuer une analyse similaire

  2. Nuclear Technology. Course 26: Nondestructive Examination (NDE) Techniques I. Module 26-6, Radiography Inspection.

    Science.gov (United States)

    Pelton, Rick; Espy, John

    This sixth in a series of seven modules for a course titled Nondestructive Examination (NDE) Techniques I explains radiographic inspection as a means of nondestructively examining components, assemblies, structures, and fabricated piping. The module follows a typical format that includes the following sections: (1) introduction, (2) module…

  3. Intercomparison of techniques for inspection and diagnostics of heavy water reactor pressure tubes. Additional information

    International Nuclear Information System (INIS)

    2009-03-01

    The reports from Argentina, Canada, India, Korea and Romania are presented concerning the projects carried out under the Coordinated Research Program (CRP) I3.30.10 of the International Agency for Atomic Energy - Vienna related to 'Intercomparison of Techniques for Pressure Tube Inspection and Diagnostics'

  4. Luminescence Imaging Strategies for Drone-Based PV Array Inspection

    DEFF Research Database (Denmark)

    Benatto, Gisele Alves dos Reis; Riedel, Nicholas; Mantel, Claire

    2017-01-01

    ) acquisition under natural light conditions during several times of the day, under high sun irradiation, to unveil the sunlight noise characteristics towards an InGaAs detector. In order to bring more freedom to a drone-based inspection, we also show the preliminary results of a laser-line based...

  5. Review of techniques for on-line monitoring and inspection of laser welding

    International Nuclear Information System (INIS)

    Shao, J; Yan, Y

    2005-01-01

    Laser welding has been applied to various industries, in particular, automotive, aerospace and microelectronics. However, traditional off-line testing of the welds is costly and inefficient. Therefore, on-line inspection systems with low cost have being developed to increase productivity and maintain high welding quality. This paper presents the applications of acoustic, optical, visual, thermal and ultrasonic techniques and latest development of laser welding monitoring. The advantages and limitations of these techniques are also discussed

  6. Comparison of API 510 pressure vessels inspection planning with API 581 risk-based inspection planning approaches

    International Nuclear Information System (INIS)

    Shishesaz, Mohammad Reza; Nazarnezhad Bajestani, Mohammad; Hashemi, Seyed Javad; Shekari, Elahe

    2013-01-01

    To ensure mechanical integrity, all pressure vessels shall be inspected at the intervals provided in inspection codes or based on a risk-based inspection (RBI) assessment. The RBI assessment may allow previously established inspection intervals to be extended. This paper describes the methodology, analysis and results of two RBI studies conducted on 293 pressure vessel components in two crude oil distillation units. Based on API RBI methodology in API 581 (2008), risk target concept was used for determining inspection dates. It was shown that when thinning is the major active damage, the RBI recommended intervals are as long as twice the API 510 intervals. This paper summarizes that, as a fundamental step in the risk calculation, RBI has a more defined methodology for evaluating equipment for multiple damage mechanisms and a more defined approach to specify the use of other inspection technologies beyond the traditional visual, ultrasonic, and radiography tests. -- Highlights: • RBI calculated inspection intervals are as long as twice of API 510 inspection code. • Two case studies verified the advantage of RBI in inspection planning. • RBI is a more reliable methodology when evaluating multiple damage mechanisms. • Damage factor calculations can be used for determining RSFa value in FFS assessments

  7. Feature Space Dimensionality Reduction for Real-Time Vision-Based Food Inspection

    Directory of Open Access Journals (Sweden)

    Mai Moussa CHETIMA

    2009-03-01

    Full Text Available Machine vision solutions are becoming a standard for quality inspection in several manufacturing industries. In the processed-food industry where the appearance attributes of the product are essential to customer’s satisfaction, visual inspection can be reliably achieved with machine vision. But such systems often involve the extraction of a larger number of features than those actually needed to ensure proper quality control, making the process less efficient and difficult to tune. This work experiments with several feature selection techniques in order to reduce the number of attributes analyzed by a real-time vision-based food inspection system. Identifying and removing as much irrelevant and redundant information as possible reduces the dimensionality of the data and allows classification algorithms to operate faster. In some cases, accuracy on classification can even be improved. Filter-based and wrapper-based feature selectors are experimentally evaluated on different bakery products to identify the best performing approaches.

  8. A novel optical investigation technique for railroad track inspection and assessment

    Science.gov (United States)

    Sabato, Alessandro; Beale, Christopher H.; Niezrecki, Christopher

    2017-04-01

    Track failures due to cross tie degradation or loss in ballast support may result in a number of problems ranging from simple service interruptions to derailments. Structural Health Monitoring (SHM) of railway track is important for safety reasons and to reduce downtime and maintenance costs. For this reason, novel and cost-effective track inspection technologies for assessing tracks' health are currently insufficient and needed. Advancements achieved in recent years in cameras technology, optical sensors, and image-processing algorithms have made machine vision, Structure from Motion (SfM), and three-dimensional (3D) Digital Image Correlation (DIC) systems extremely appealing techniques for extracting structural deformations and geometry profiles. Therefore, optically based, non-contact measurement techniques may be used for assessing surface defects, rail and tie deflection profiles, and ballast condition. In this study, the design of two camera-based measurement systems is proposed for crossties-ballast condition assessment and track examination purposes. The first one consists of four pairs of cameras installed on the underside of a rail car to detect the induced deformation and displacement on the whole length of the track's cross tie using 3D DIC measurement techniques. The second consists of another set of cameras using SfM techniques for obtaining a 3D rendering of the infrastructure from a series of two-dimensional (2D) images to evaluate the state of the track qualitatively. The feasibility of the proposed optical systems is evaluated through extensive laboratory tests, demonstrating their ability to measure parameters of interest (e.g. crosstie's full-field displacement, vertical deflection, shape, etc.) for assessment and SHM of railroad track.

  9. Risk-based inspection and maintenance systems for steam turbines

    International Nuclear Information System (INIS)

    Fujiyama, Kazunari; Nagai, Satoshi; Akikuni, Yasunari; Fujiwara, Toshihiro; Furuya, Kenichiro; Matsumoto, Shigeru; Takagi, Kentaro; Kawabata, Taro

    2004-01-01

    The risk-based maintenance (RBM) system has been developed for steam turbine plants coupled with the quick inspection systems. The RBM system utilizes the field failure and inspection database accumulated over 30 years. The failure modes are determined for each component of steam turbines and the failure scenarios are described as event trees. The probability of failure is expressed in the form of unreliability functions of operation hours or start-up cycles through the cumulative hazard function method. The posterior unreliability is derived from the field data analysis according to the inspection information. Quick inspection can be conducted using air-cooled borescope and heat resistant ultrasonic sensors even if the turbine is not cooled down sufficiently. Another inspection information comes from degradation and damage measurement. The probabilistic life assessment using structural analysis and statistical material properties, the latter is estimated from hardness measurement, replica observation and embrittlement measurement. The risk function is calculated as the sum product of unreliability functions and expected monetary loss as the consequence of failure along event trees. The optimum maintenance plan is determined among simulated scenarios described through component breakdown trees, life cycle event trees and risk functions. Those methods are effective for total condition assessment and economical maintenance for operating plants

  10. Risk Based Inspection of Gas-Cooling Heat Exchanger

    Directory of Open Access Journals (Sweden)

    Dwi Priyanta

    2017-09-01

    Full Text Available On October 2013, Pertamina Hulu Energi Offshore North West Java (PHE – ONWJ platform personnel found 93 leaking tubes locations in the finfan coolers/ gas-cooling heat exchanger. After analysis had been performed, the crack in the tube strongly indicate that stress corrosion cracking was occurred by chloride. Chloride stress corrosion cracking (CLSCC is the cracking occurred by the combined influence of tensile stress and a corrosive environment. CLSCC is the one of the most common reasons why austenitic stainless steel pipework or tube and vessels deteriorate in the chemical processing, petrochemical industries and maritime industries. In this thesis purpose to determine the appropriate inspection planning for two main items (tubes and header box in the gas-cooling heat exchanger using risk based inspection (RBI method. The result, inspection of the tubes must be performed on July 6, 2024 and for the header box inspection must be performed on July 6, 2025. In the end, RBI method can be applicated to gas-cooling heat exchanger. Because, risk on the tubes can be reduced from 4.537 m2/year to 0.453 m2/year. And inspection planning for header box can be reduced from 4.528 m2/year to 0.563 m2/year.

  11. Review of In-Service Inspection and Repair Technique Developments for French Liquid Metal Fast Reactors

    International Nuclear Information System (INIS)

    Baque, F.

    2005-01-01

    In-service monitoring of nuclear plants is indispensable for both the Operator and the Regulator. The notion of in-service monitoring ranges from the continuous monitoring of the reactor in operation to the thorough in-service reactor inspection during programmed shutdowns. However, the highly specific environment found in French liquid metal fast reactor plants - Phenix and Superphenix - makes monitoring and inspection complicated because of the use of a sodium coolant that is hot, opaque, and difficult to drain.The Commissariat a l'Energie Atomique, in collaboration with its traditional French partners, Electricite de France utilities and FRAMATOME/Novatome Engineering, decided to conduct a 6-yr research and development program (1994-2000) to explore this problem vis-a-vis Superphenix, as well as the possibilities of intervening within the reactor block or on components in a sodium environment. Furthermore, the safety reevaluation of Phenix, conducted between 1994 and 2003, represented an excellent 'test bench' during which the limits of inspection processes - applied to an integrated reactor concept - were surpassed using techniques such as fuel subassembly head scanning, ultrasonic examination of the core support, and visual inspection of the cover-gas plenum following a partial sodium draining. Repair techniques were investigated for cleaning of sodium wet structure surfaces, cutting of damaged parts, and welding in sodium aerosol atmosphere. Both conventional and laser processes were tested

  12. Generalizing Perspective-based Inspection to handle Object-Oriented Development Artifacts

    OpenAIRE

    Laitenberger, O.; Atkinson, C.

    1998-01-01

    The value of software inspection for uncovering defects early in the development lifecycle has been well documented. Of the various types of inspection methods published to date, experiments have shown perspective-based inspection to be one of the most effective, because of its enhanced coverage of the defect space. However, inspections in general, and perspective-based inspections in particular, have so far been applied predominantly in the context of conventional structured development meth...

  13. Fast in-situ tool inspection based on inverse fringe projection and compact sensor heads

    Science.gov (United States)

    Matthias, Steffen; Kästner, Markus; Reithmeier, Eduard

    2016-11-01

    Inspection of machine elements is an important task in production processes in order to ensure the quality of produced parts and to gather feedback for the continuous improvement process. A new measuring system is presented, which is capable of performing the inspection of critical tool geometries, such as gearing elements, inside the forming machine. To meet the constraints on sensor head size and inspection time imposed by the limited space inside the machine and the cycle time of the process, the measuring device employs a combination of endoscopy techniques with the fringe projection principle. Compact gradient index lenses enable a compact design of the sensor head, which is connected to a CMOS camera and a flexible micro-mirror based projector via flexible fiber bundles. Using common fringe projection patterns, the system achieves measuring times of less than five seconds. To further reduce the time required for inspection, the generation of inverse fringe projection patterns has been implemented for the system. Inverse fringe projection speeds up the inspection process by employing object-adapted patterns, which enable the detection of geometry deviations in a single image. Two different approaches to generate object adapted patterns are presented. The first approach uses a reference measurement of a manufactured tool master to generate the inverse pattern. The second approach is based on a virtual master geometry in the form of a CAD file and a ray-tracing model of the measuring system. Virtual modeling of the measuring device and inspection setup allows for geometric tolerancing for free-form surfaces by the tool designer in the CAD-file. A new approach is presented, which uses virtual tolerance specifications and additional simulation steps to enable fast checking of metric tolerances. Following the description of the pattern generation process, the image processing steps required for inspection are demonstrated on captures of gearing geometries.

  14. Management of Microbiologically Influenced Corrosion in Risk-Based Inspection Analysis

    DEFF Research Database (Denmark)

    Skovhus, Torben Lund; Andersen, Erlend S.; Hillier, Elisabeth

    2018-01-01

    Operating offshore oil and gas production facilities is often associated with high risk. To manage the risk, operators commonly use aids to support decision making in the establishment of a maintenance and inspection strategy. Risk-based inspection (RBI) analysis is widely used in the offshore...... industry as a means to justify the inspection strategy adopted. The RBI analysis is a decision-making technique that enables asset managers to identify the risk related to failure of their most critical systems and components, with an effect on safety, environmental, and business-related issues. Risk...... influenced corrosion (MIC) is a degradation mechanism that has received increased attention from corrosion engineers and asset operators in the past decades. In this paper, the most recent models that have been developed to assess the impact of MIC on asset integrity will be presented and discussed. From...

  15. Application of risk-based inspection methods for cryogenic equipment

    CERN Multimedia

    CERN. Geneva

    2016-01-01

    Risk-based Inspection (RBI) is widely applied across the world as part of Pressure Equipment Integrity Management, especially in the oil and gas industry, to generally reduce costs compared with time-based approaches and assist in assigning resources to the most critical equipment. One of the challenges in RBI is to apply it for low temperature and cryogenic applications, as there are usually no degradation mechanisms by which to determine a suitable probability of failure in the overall risk assessment. However, the assumptions used for other degradation mechanisms can be adopted to determine, qualitatively and semi-quantitatively, a consequence of failure within the risk assessment. This can assist in providing a consistent basis for the assumptions used in ensuring adequate process safety barriers and determining suitable sizing of relief devices. This presentation will discuss risk-based inspection in the context of cryogenic safety, as well as present some of the considerations for the risk assessme...

  16. Application of the cylindrically guided wave technique for bolt and pump-shaft inspections

    International Nuclear Information System (INIS)

    Light, G.M.; Ruescher, E.H.; Bloom, E.A.; Tsai, Y.M.

    1990-01-01

    Southwest Research Institute (SwRI) has been working with the cylindrically guided wave technique (CGWT) since late 1982. The initial work was aimed at inspecting reactor pressure vessel hold-down studs. The CGWT was shown to be able to detect defects as small as 0.060 inch (1.5 mm) deep through metal paths up to 120 inches (304 cm) in stud bolt carbon steel. Later developments in the application of CGWT were aimed at inspecting reactor coolant pump (RCP) shafts. The RCP shafts are usually approximately 2 meters long and have changing diameters along the length, from approximately 12 cm to 23 cm in discrete steps. The pump shafts have been susceptible to small cracks and can be inspected most cost-effectively from the top of the shaft. A matrix transducer composed of six 1-inch (2.54-cm) diameter transducers along with pulsing and receiving electronics (EPRI Pump-Shaft Inspection System) was developed during 1988. A patent application for this technology has been made. This report describes the work conducted during 1989 and the results obtained

  17. Non-destructive radiometry inspection technique for locating reinforcements and void/porosity in bridge bearings

    International Nuclear Information System (INIS)

    Yahaya bin Jafar; Jaafar bin Abdullah; Mohamad Azmi bin Ismail.

    1989-01-01

    Defects detection in bridge bearings is very important in controlling quality and safety. Typical manufacturing defects include misalligned or bent steel plates and the presence of voids/porosity within the rubber. A non-destructive radiometry inspection technique was used to locate steel plates position and the presence of voids/porosity in bridge bearing samples provided by the Rubber Research Institute of Malaysia (RRIM). Preliminary studies show that the mentioned defects can readily be determined by this technique. Some of the results are also presented. (author)

  18. Technique for rapid at-wavelength inspection of extreme ultraviolet mask blanks

    International Nuclear Information System (INIS)

    Spector, S. J.; White, D. L.; Tennant, D. M.; Ocola, L. E.; Novembre, A. E.; Peabody, M. L.; Wood, O. R. II

    1999-01-01

    We have developed two new methods for at-wavelength inspection of mask blanks for extreme-ultraviolet (EUV) lithography. In one method an EUV photoresist is applied directly to a mask blank which is then flood exposed with EUV light and partially developed. In the second method, the photoresist is applied to an EUV transparent membrane that is placed in close proximity to the mask and then exposed and developed. Both reflectivity defects and phase defects alter the exposure of the resist, resulting in mounds of resist at defect sites that can then be located by visual inspection. In the direct application method, a higher contrast resist was shown to increase the height of the mounds, thereby improving the sensitivity of the technique. In the membrane method, a holographic technique was used to reconstruct an image of the mask, revealing the presence of very small defects, approximately 0.2 μm in size. The demonstrated clean transfer of phase and amplitude defects to resist features on a membrane will be important when flagging defects in an automatic inspection tool. (c) 1999 American Vacuum Society

  19. Verification of split spectrum technique for ultrasonic inspection of welded structures in nuclear reactors

    International Nuclear Information System (INIS)

    Ericsson, L.; Stepinski, T.

    1992-01-01

    Ultrasonic nondestructive inspection of materials is often limited by the presence of backscattered echoes from the material structure. A digital signal processing technique for removal of this material noise, referred to as split spectrum processing (SSP), has been developed and verified using simple laboratory experiments during the last decade. However, application of the split spectrum processing algorithm to industrial conditions has been rarely reported. In the paper the results of the practical evaluation of the SSP technique are presented. A number of different ultrasonic transducers were used for acquiring echoes from artificial flaws as well as natural cracks. The flaws were located in test blocks employed by the Swedish Nuclear Power Companies as reference during ultrasonic inspection of nuclear reactor vessels. The acquired ultrasonic A-scan signals were processed off-line using specially developed algorithms on a personal computer (PC). The experiments show evidence that properly tuned SSP algorithms result in a considerable improvement of the signal to material noise ratio. The enhancements were similar irrespective of the features of the transducer used or the nature of the inspected flaw. The problems related to the development of self-tuning SSP algorithms for on-line processing of B-scans are discussed. (author)

  20. Application of non-destructive liner thickness measurement technique for manufacturing and inspection process of zirconium lined cladding tube

    International Nuclear Information System (INIS)

    Nakazawa, Norio; Fukuda, Akihiro; Fujii, Noritsugu; Inoue, Koichi

    1986-01-01

    Recently, in order to meet the difference of electric power demand owing to electric power situation, large scale load following operation has become necessary. Therefore, the development of the cladding tubes which withstand power variation has been carried out, as the result, zirconium-lined zircaloy 2 cladding tubes have been developed. In order to reduce the sensitivity to stress corrosion cracking, these zirconium-lined cladding tubes require uniform liner thickness over the whole surface and whole length. Kobe Steel Ltd. developed the nondestructive liner thickness measuring technique based on ultrasonic flaw detection technique and eddy current flaw detection technique. These equipments were applied to the manufacturing and inspection processes of the zirconium-lined cladding tubes, and have demonstrated superiority in the control and assurance of the liner thickness of products. Zirconium-lined cladding tubes, the development of the measuring technique for guaranteeing the uniform liner thickness and the liner thickness control in the manufacturing and inspection processes are described. (Kako, I.)

  1. Proving the capabilities of the phased-array probe/ALOK inspection technique

    International Nuclear Information System (INIS)

    Bohn, H.; Kroening, M.; Rathgeb, W.; Gebhardt, W.; Kappes, W.; Barbian, O.A.

    1987-01-01

    The capability of the ALOK phased-probe-array inspection technique results from the simplicity of the testing system structure, the reflector detection and identification by means of transit time curves, and the analytical capacity of the system. Testing times are shortened, with the test results meeting the current standards, and further possibilities being given: Areas that could so far only be inspected with difficulty of not at all, can be examined, thanks to the compact equipment and without having to modify the system, very informative analysis measurements for interpreting indications can be made. Furthermore, it may be expected from the testing practice that descriptions of indications will become more reliable and reproducible, due to transit time curve identification. In addition to conventional criteria for reflector evaluation, the potential of transit time curve identification, and flaw boundary imaging of the reconstruction image can be utilized. (orig.)

  2. Vision based tunnel inspection using non-rigid registration

    Science.gov (United States)

    Badshah, Amir; Ullah, Shan; Shahzad, Danish

    2015-04-01

    Growing numbers of long tunnels across the globe has increased the need for safety measurements and inspections of tunnels in these days. To avoid serious damages, tunnel inspection is highly recommended at regular intervals of time to find any deformations or cracks at the right time. While following the stringent safety and tunnel accessibility standards, conventional geodetic surveying using techniques of civil engineering and other manual and mechanical methods are time consuming and results in troublesome of routine life. An automatic tunnel inspection by image processing techniques using non rigid registration has been proposed. There are many other image processing methods used for image registration purposes. Most of the processes are operation of images in its spatial domain like finding edges and corners by Harris edge detection method. These methods are quite time consuming and fail for some or other reasons like for blurred or images with noise. Due to use of image features directly by these methods in the process, are known by the group, correlation by image features. The other method is featureless correlation, in which the images are converted into its frequency domain and then correlated with each other. The shift in spatial domain is the same as in frequency domain, but the processing is order faster than in spatial domain. In the proposed method modified normalized phase correlation has been used to find any shift between two images. As pre pre-processing the tunnel images i.e. reference and template are divided into small patches. All these relative patches are registered by the proposed modified normalized phase correlation. By the application of the proposed algorithm we get the pixel movement of the images. And then these pixels shifts are converted to measuring units like mm, cm etc. After the complete process if there is any shift in the tunnel at described points are located.

  3. Ultrasonic, microwave, and millimeter wave inspection techniques for adhesively bonded stacked open honeycomb core composites

    Science.gov (United States)

    Thomson, Clint D.; Cox, Ian; Ghasr, Mohammad Tayeb Ahmed; Ying, Kuang P.; Zoughi, Reza

    2015-03-01

    Honeycomb sandwich composites are used extensively in the aerospace industry to provide stiffness and thickness to lightweight structures. A common fabrication method for thick, curved sandwich structures is to stack and bond multiple honeycomb layers prior to machining core curvatures. Once bonded, each adhesive layer must be inspected for delaminations and the presence of unwanted foreign materials. From a manufacturing and cost standpoint, it can be advantageous to inspect the open core prior to face sheet closeout in order to reduce end-article scrap rates. However, by nature, these honeycomb sandwich composite structures are primarily manufactured from low permittivity and low loss materials making detection of delamination and some of the foreign materials (which also are low permittivity and low loss) quite challenging in the microwave and millimeter wave regime. Likewise, foreign materials such as release film in adhesive layers can be sufficiently thin as to not cause significant attenuation in through-transmission ultrasonic signals, making them difficult to detect. This paper presents a collaborative effort intended to explore the efficacy of different non-contact NDI techniques for detecting flaws in a stacked open fiberglass honeycomb core panel. These techniques primarily included air-coupled through-transmission ultrasonics, single-sided wideband synthetic aperture microwave and millimeter-wave imaging, and lens-focused technique. The goal of this investigation has been to not only evaluate the efficacy of these techniques, but also to determine their unique advantages and limitations for evaluating parameters such as flaw type, flaw size, and flaw depth.

  4. Development of an ultrasonic weld inspection system based on image processing and neural networks

    Science.gov (United States)

    Roca Barceló, Fernando; Jaén del Hierro, Pedro; Ribes Llario, Fran; Real Herráiz, Julia

    2018-04-01

    Several types of discontinuities and defects may be present on a weld, thus leading to a considerable reduction of its resistance. Therefore, ensuring a high welding quality and reliability has become a matter of key importance for many construction and industrial activities. Among the non-destructive weld testing and inspection techniques, the time-of-flight diffraction (TOFD) arises as a very safe (no ionising radiation), precise, reliable and versatile practice. However, this technique presents a relevant drawback, associated to the appearance of speckle noise that should be addressed. In this regard, this paper presents a new, intelligent and automatic method for weld inspection and analysis, based on TOFD, image processing and neural networks. The developed system is capable of detecting weld defects and imperfections with accuracy, and classify them into different categories.

  5. From PISC to risk informed inspection

    International Nuclear Information System (INIS)

    Crutzen, S.; Lemaitre, P.; Fabbri, L.

    1998-01-01

    In this paper the correlation between inspection effectiveness, inspection qualification and risk informed inspection will be treated in view of harmonisation of inspection of nuclear plant components. Through the different phases of the PISC programme the necessity has been demonstrated to show the effectiveness of the inspection through a formal process of qualification in order to ensure that a certain level of effectiveness has been reached. Inspection qualification is indeed the way to quantify the capability level of inspection techniques used. The targets to be met by the inspection is information which should be obtained from risk based analyses. (author)

  6. Reliability-based inspection of prestressed concrete containment structures

    International Nuclear Information System (INIS)

    Pandey, M.D.

    1996-03-01

    A study was undertaken to develop a reliability-based approach to the planning of inspection programs for prestressed concrete containment structures. The main function of the prestressing system is to ensure the leak integrity of the containment by maintaining a compressive state of stress under the tensile forces which arise in a hypothesized loss of coolant accident. Prestressing force losses (due to creep and shrinkage, stress relaxation or tendon corrosion) can lead to tensile stresses under accident pressure, resulting in loss of containment leak integrity due to concrete cracking and tensile yielding of the non-prestressed reinforcement. Therefore, the evaluation of prestressing inspection programs was based on their effectiveness in maintaining an acceptable reliability level with respect to a limit state representing yeilding of non-prestressed reinforcement. An annual target reliability of 10 -4 was used for this limit state. As specified in CSA-N287.7, the evaluation of prestressing systems for containment structures is based on the results of lift-off tests to determine the prestressing force. For unbonded systems the tests are carried out on a randomly selected sample from each tendon group in the structure. For bonded systems, the test is carried out on an unbonded test beam that matches the section geometry and material properties of the containment structure. It was found that flexural testing is useful in updating the probability of concrete cracking under accident pressure. For unbonded systems, the analysis indicated that the sample size recommended by the CSA Standard (4% of the tendon population) is adequate. The CSA recommendation for a five year inspection interval is conservative unless severe degradation of the prestressing system, characterized by a high prestressing loss rate (>3%) and a large coefficient of variation of the measured prestressing force (>15%), is observed

  7. Evaluation of computer-based ultrasonic inservice inspection systems

    International Nuclear Information System (INIS)

    Harris, R.V. Jr.; Angel, L.J.; Doctor, S.R.; Park, W.R.; Schuster, G.J.; Taylor, T.T.

    1994-03-01

    This report presents the principles, practices, terminology, and technology of computer-based ultrasonic testing for inservice inspection (UT/ISI) of nuclear power plants, with extensive use of drawings, diagrams, and LTT images. The presentation is technical but assumes limited specific knowledge of ultrasonics or computers. The report is divided into 9 sections covering conventional LTT, computer-based LTT, and evaluation methodology. Conventional LTT topics include coordinate axes, scanning, instrument operation, RF and video signals, and A-, B-, and C-scans. Computer-based topics include sampling, digitization, signal analysis, image presentation, SAFI, ultrasonic holography, transducer arrays, and data interpretation. An evaluation methodology for computer-based LTT/ISI systems is presented, including questions, detailed procedures, and test block designs. Brief evaluations of several computer-based LTT/ISI systems are given; supplementary volumes will provide detailed evaluations of selected systems

  8. Update on the EPRI power generation risk-based inservice inspection pilot plant studies

    International Nuclear Information System (INIS)

    Gosselin, S.R.

    1997-01-01

    The scope for ASME Section XI ISI programs is largely based on deterministic results contained in design stress reports. These reports are normally very conservative and may not be an accurate representation of failure potential. Service experience has shown that failures are due to either corrosion or fatigue and typically occur in areas not included in the plant's ISI program. Consequently, nuclear plants are devoting significant resources to inspection programs that provide minimum benefit. As an alternative, significant industry attention has been devoted to the application of risked-based selection criteria in order to determine the scope of inservice inspection (ISI) programs at nuclear power plants. Preliminary EPRI studies indicate that the application of these techniques will allow operating nuclear plants to reduce the examination scope of current ISI programs by as much as 60 to 80%, significantly reduce costs, and continue to maintain high nuclear plant safety standards

  9. A strategy for the risk-based inspection of pressure safety valves

    International Nuclear Information System (INIS)

    Chien, C.-H.; Chen, C.-H.; Chao, Y.J.

    2009-01-01

    The purpose of a pressure safety valve (PSV) is to protect the life and safety of pressure vessels in a pressurized system. If a weakened PSV fails to function properly, a catastrophic event might occur if no other protective means are provided. By utilizing the as-received test data and statistical analysis of the aging conditions of PSVs in lubricant process units, a risk-based inspection (RBI) system was developed in this study. First of all, the characteristics of PSV were discussed from the practical viewpoint of engineering inspection and maintenance. The as-received test data, which shows obvious PSV damage, will be separated from the data used in the following statistical analysis. Then, the relationship between the aging conditions and the corresponding PSV parameters was analyzed by using the statistical technique-analysis of variance (ANOVA). Finally, a strategy for semi-quantitative RBI is proposed. Also, a definitive estimated inspection interval for every PSV is suggested. The outcome indicated most of the risks result from a few PSVs, for which the corresponding inspection intervals will be shorter than the 2 years in accordance with relative standards and local government regulations

  10. Feasibility of developing risk-based rankings of pressure boundary systems for inservice inspection

    Energy Technology Data Exchange (ETDEWEB)

    Vo, T.V.; Smith, B.W.; Simonen, F.A.; Gore, B.F.

    1994-08-01

    The goals of the Evaluation and Improvement of Non-destructive Examination Reliability for the In-service Inspection of Light Water Reactors Program sponsored by the Nuclear Regulatory Commission at Pacific Northwest Laboratory (PNL) are to (1) assess current ISI techniques and requirements for all pressure boundary systems and components, (2) determine if improvements to the requirements are needed, and (3) if necessary, develop recommendations for revising the applicable ASME Codes and regulatory requirements. In evaluating approaches that could be used to provide a technical basis for improved inservice inspection plans, PNL has developed and applied a method that uses results of probabilistic risk assessment (PRA) to establish piping system ISI requirements. In the PNL program, the feasibility of generic ISI requirements is being addressed in two phases. Phase I involves identifying and prioritizing the systems most relevant to plant safety. The results of these evaluations will be later consolidated into requirements for comprehensive inservice inspection of nuclear power plant components that will be developed in Phase II. This report presents Phase I evaluations for eight selected plants and attempts to compare these PRA-based inspection priorities with current ASME Section XI requirements for Class 1, 2 and 3 systems. These results show that there are generic insights that can be extrapolated from the selected plants to specific classes of light water reactors.

  11. Feasibility of developing risk-based rankings of pressure boundary systems for inservice inspection

    International Nuclear Information System (INIS)

    Vo, T.V.; Smith, B.W.; Simonen, F.A.; Gore, B.F.

    1994-08-01

    The goals of the Evaluation and Improvement of Non-destructive Examination Reliability for the In-service Inspection of Light Water Reactors Program sponsored by the Nuclear Regulatory Commission at Pacific Northwest Laboratory (PNL) are to (1) assess current ISI techniques and requirements for all pressure boundary systems and components, (2) determine if improvements to the requirements are needed, and (3) if necessary, develop recommendations for revising the applicable ASME Codes and regulatory requirements. In evaluating approaches that could be used to provide a technical basis for improved inservice inspection plans, PNL has developed and applied a method that uses results of probabilistic risk assessment (PRA) to establish piping system ISI requirements. In the PNL program, the feasibility of generic ISI requirements is being addressed in two phases. Phase I involves identifying and prioritizing the systems most relevant to plant safety. The results of these evaluations will be later consolidated into requirements for comprehensive inservice inspection of nuclear power plant components that will be developed in Phase II. This report presents Phase I evaluations for eight selected plants and attempts to compare these PRA-based inspection priorities with current ASME Section XI requirements for Class 1, 2 and 3 systems. These results show that there are generic insights that can be extrapolated from the selected plants to specific classes of light water reactors

  12. Application of acoustic emission, as non destructive testing technique, to nuclear components inspection

    International Nuclear Information System (INIS)

    Sanchez Miro, J.J.

    1980-01-01

    A panorama of actual state of acoustic emission as non destructive testing technique, from stand point of its safety applications to nuclear reactor is offered. In first place the physic grounds of acoustic emission phenomenon is briefly exposed. After we speak about the experimental methods for detection, and overall is made an explanation of the problems which are found during the application of this technology to on-line inspection of nuclear oower plants. It is hoped that this repport makes a contribution in the sense of to create a favourable atmosphere toward the introduction in our country of this important technique, and concretely within the nuclear power industry. In this last field the employ of acoustic emission is overcoming the experimental stage. (author)

  13. Development of phased array UT technique for inspection of turbine wheel rim

    International Nuclear Information System (INIS)

    Komura, I.; Nagal, S.; Goto, M.; Ohmatsu, K.

    1986-01-01

    A phased array UT technique has been developed for the improvement of defect detection under the keyway region of shrunk-on type turbine wheel. The sector scanning mode operation with plexiglas wedge of phased array capability was applied to construct the B-scope image of turbine wheel rim region. Preceding to the inspection test of the model specimen having real shape of rim region, the distribution of sound field intensity along the steering angle of the scanning line was measured on the test block. Then, the minimum depth of detectable defect by the B-scope imaging was evaluated on the dovetail shape specimens which had different depth EDM notches at the each hook fillet. As the results, it has been realized that the B-scope imaging of the sector scanning mode phased array technique has a capability for distinguishing the defect echoes from the many reflection echoes caused by the complexed shape of wheel rim region

  14. Machine vision based quality inspection of flat glass products

    Science.gov (United States)

    Zauner, G.; Schagerl, M.

    2014-03-01

    This application paper presents a machine vision solution for the quality inspection of flat glass products. A contact image sensor (CIS) is used to generate digital images of the glass surfaces. The presented machine vision based quality inspection at the end of the production line aims to classify five different glass defect types. The defect images are usually characterized by very little `image structure', i.e. homogeneous regions without distinct image texture. Additionally, these defect images usually consist of only a few pixels. At the same time the appearance of certain defect classes can be very diverse (e.g. water drops). We used simple state-of-the-art image features like histogram-based features (std. deviation, curtosis, skewness), geometric features (form factor/elongation, eccentricity, Hu-moments) and texture features (grey level run length matrix, co-occurrence matrix) to extract defect information. The main contribution of this work now lies in the systematic evaluation of various machine learning algorithms to identify appropriate classification approaches for this specific class of images. In this way, the following machine learning algorithms were compared: decision tree (J48), random forest, JRip rules, naive Bayes, Support Vector Machine (multi class), neural network (multilayer perceptron) and k-Nearest Neighbour. We used a representative image database of 2300 defect images and applied cross validation for evaluation purposes.

  15. A Laser-based Ultrasonic Inspection System to Detect Micro Fatigue Cracks

    International Nuclear Information System (INIS)

    Park, Seung Kyu; Baik, Sung Hoon; Park, Moon Cheol; Lim, Chang Hwan; Cha, Hyung Ki

    2005-01-01

    Laser-based ultrasonic techniques have been established as a viable non-contact alternative to piezoelectric transducers for generating and receiving ultrasound. Laser-based ultrasonic inspection system provides a number of advantages over the conventional generation by piezoelectric transducers, especially a non-contact generation and detection of ultrasonic waves, high spatial scanning resolution, controllable narrow-band and wide-band spectrum, absolute measurements of the moving distance, use of fiber optics, and an ability to operate on curved and rough surfaces and at hard-to-access locations like a nuclear power plant. Ochiai and Miura used the laser-based ultrasound to detect micro fatigue cracks for the inspection of a material degradation in nuclear power plants. This widely applicable laser-based ultrasonic inspection system is comparatively expensive and provides low signal-to-noise ratio to measure ultrasound by using the laser interferometer. Many studies have been carried out to improve the measuring efficiency of the laser interferometer. One of the widely used laser interferometer types to measure the ultrasound is the Confocal Fabry-Perot Interferometer(CFPI). The measurement gain of the CFPI is slightly and continually varied according to the small change of the cavity length and the fluctuations of the measuring laser beam frequency with time. If we continually adjust the voltage of a PZT which is fixed to one of the interferometer mirrors, the optimum working point of the CFPI can be fixed. Though a static stabilizer can fix the gain of the CFPI where the CW laser beam is targeted at one position, it can not be used when the CW laser beam is scanned like a scanning laser source(SLS) technique. A dynamic stabilizer can be used for the scanning ultrasonic inspection system. A robust dynamic stabilizer is needed for an application to the industrial inspection fields. Kromine showed that the SLS technique is effective to detect small fatigue cracks

  16. Use of knowledge based systems for rational reliability analysis based inspection and maintenance planning for offshore structures

    International Nuclear Information System (INIS)

    Tang, M.X.; Dharmavasan, S.; Peers, S.M.C.

    1994-01-01

    The structural integrity of fixed offshore platforms is ensured by periodic inspections. In the past, decisions made as to when, where and how to inspect have been made by engineers using rules-of-thumb and general planning heuristics. It is now hoped that more rational inspection and maintenance scheduling may be carried out by applying recently developed techniques based on structural reliability methods. However, one of the problems associated with a theoretical approach is that it is not always possible to incorporate all the constraints that are present in a practical situation. These constraints modify the decisions made for analysis data input and the interpretation of the analysis results. Knowledge based systems provide a mean of encapsulating several different forms of information and knowledge within a computer system and hence can overcome this problem. In this paper, a prototype system being developed for integrating reliability based analysis with other constraints for inspection scheduling will be described. In addition, the scheduling model and the algorithms to carry out the scheduling will be explained. Furthermore, implementation details are also given

  17. A pattern-based method to automate mask inspection files

    Science.gov (United States)

    Kamal Baharin, Ezni Aznida Binti; Muhsain, Mohamad Fahmi Bin; Ahmad Ibrahim, Muhamad Asraf Bin; Ahmad Noorhani, Ahmad Nurul Ihsan Bin; Sweis, Jason; Lai, Ya-Chieh; Hurat, Philippe

    2017-03-01

    Mask inspection is a critical step in the mask manufacturing process in order to ensure all dimensions printed are within the needed tolerances. This becomes even more challenging as the device nodes shrink and the complexity of the tapeout increases. Thus, the amount of measurement points and their critical dimension (CD) types are increasing to ensure the quality of the mask. In addition to the mask quality, there is a significant amount of manpower needed when the preparation and debugging of this process are not automated. By utilizing a novel pattern search technology with the ability to measure and report match region scan-line (edge) measurements, we can create a flow to find, measure and mark all metrology locations of interest and provide this automated report to the mask shop for inspection. A digital library is created based on the technology product and node which contains the test patterns to be measured. This paper will discuss how these digital libraries will be generated and then utilized. As a time-critical part of the manufacturing process, this can also reduce the data preparation cycle time, minimize the amount of manual/human error in naming and measuring the various locations, reduce the risk of wrong/missing CD locations, and reduce the amount of manpower needed overall. We will also review an example pattern and how the reporting structure to the mask shop can be processed. This entire process can now be fully automated.

  18. Linac based photofission inspection system employing novel detection concepts

    Energy Technology Data Exchange (ETDEWEB)

    Stevenson, John, E-mail: jstevenson@rapiscansystems.com [Rapiscan Laboratories, Inc., 520 Almanor Avenue, Sunnyvale, CA 94085 (United States); Gozani, Tsahi, E-mail: tgozani@rapiscansystems.com [Rapiscan Laboratories, Inc., 520 Almanor Avenue, Sunnyvale, CA 94085 (United States); Elsalim, Mashal; Condron, Cathie; Brown, Craig [Rapiscan Laboratories, Inc., 520 Almanor Avenue, Sunnyvale, CA 94085 (United States)

    2011-10-01

    Rapiscan Systems is developing a LINAC based cargo inspection system for detection of special nuclear material (SNM) in cargo containers. The system, called Photofission Based Alarm Resolution (PBAR) is being developed under a DHD/DNDO Advanced Technology Demonstration (ATD) program. The PBAR system is based on the Rapiscan Eagle P9000 X-ray system, which is a portal system with a commercial 9 MeV LINAC X-ray source. For the purposes of the DNDO ATD program, a conveyor system was installed in the portal to allow scanning and precise positioning of 20 ft ISO cargo containers. The system uses a two step inspection process. In the first step, the basic scan, the container is quickly and completely inspected using two independent radiography arrays: the conventional primary array with high spatial resolution and a lower resolution spectroscopic array employing the novel Z-Spec method. The primary array uses cadmium tungstate (CdWO{sub 4}) detectors with conventional current mode readouts using photodiodes. The Z-Spec array uses small plastic scintillators capable of performing very fast (up to 10{sup 8} cps) gamma-ray spectroscopy. The two radiography arrays are used to locate high-Z objects in the image such as lead, tungsten, uranium, which could be potential shielding materials as well as SNM itself. In the current system, the Z-Spec works by measuring the energy spectrum of transmitted X-rays. For high-Z materials the higher end of the energy spectrum is more attenuated than for low-Z materials and thus has a lower mean energy and a narrower width than low- and medium-Z materials. The second step in the inspection process is the direct scan or alarm clearing scan. In this step, areas of the container image, which were identified as high Z, are re-inspected. This is done by precisely repositioning the container to the location of the high-Z object and performing a stationary irradiation of the area with X-ray beam. Since there are a large number of photons in the 9

  19. Linac based photofission inspection system employing novel detection concepts

    International Nuclear Information System (INIS)

    Stevenson, John; Gozani, Tsahi; Elsalim, Mashal; Condron, Cathie; Brown, Craig

    2011-01-01

    Rapiscan Systems is developing a LINAC based cargo inspection system for detection of special nuclear material (SNM) in cargo containers. The system, called Photofission Based Alarm Resolution (PBAR) is being developed under a DHD/DNDO Advanced Technology Demonstration (ATD) program. The PBAR system is based on the Rapiscan Eagle P9000 X-ray system, which is a portal system with a commercial 9 MeV LINAC X-ray source. For the purposes of the DNDO ATD program, a conveyor system was installed in the portal to allow scanning and precise positioning of 20 ft ISO cargo containers. The system uses a two step inspection process. In the first step, the basic scan, the container is quickly and completely inspected using two independent radiography arrays: the conventional primary array with high spatial resolution and a lower resolution spectroscopic array employing the novel Z-Spec method. The primary array uses cadmium tungstate (CdWO 4 ) detectors with conventional current mode readouts using photodiodes. The Z-Spec array uses small plastic scintillators capable of performing very fast (up to 10 8 cps) gamma-ray spectroscopy. The two radiography arrays are used to locate high-Z objects in the image such as lead, tungsten, uranium, which could be potential shielding materials as well as SNM itself. In the current system, the Z-Spec works by measuring the energy spectrum of transmitted X-rays. For high-Z materials the higher end of the energy spectrum is more attenuated than for low-Z materials and thus has a lower mean energy and a narrower width than low- and medium-Z materials. The second step in the inspection process is the direct scan or alarm clearing scan. In this step, areas of the container image, which were identified as high Z, are re-inspected. This is done by precisely repositioning the container to the location of the high-Z object and performing a stationary irradiation of the area with X-ray beam. Since there are a large number of photons in the 9 MV

  20. Development of ultrasonic testing technique to inspect containment liners embedded in concrete on nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Ishida, H.; Kurozumi, Y. [Inst. of Nuclear Safety System, Incorporated, Mihama, Fukui (Japan); Kaneshima, Y. [The Kansai Electric Power Company, Inc., Mihama, Fukui (Japan)

    2004-07-01

    The purpose of this study is development of ultrasonic testing technique to inspect containment liners embedded in concrete on nuclear power plants. Integrity of containment liners on nuclear power plants can be secured by suitable present operation and maintenance. Furthermore, non-destructive testing technique to inspect embedded liners will ensure the integrity of the containment further. In order to develop the non-destructive testing technique, ultrasonic transducers were made newly and ultrasonic testing data acquisition and evaluation were carried out by using a mock-up. We adopted the surface shear horizontal (SH) wave, low frequency (0.3-0.5MHz), to be able to detect an echo from a defect against attenuation of ultrasonic waves due to long propagation in the liners and dispersion into concrete. We made transducers with three large active elements (40mm x 40mm) in a line which were equivalent to a 120mm width active element. Artificial hollows, {phi}200mm - 19mm depth (1/2thickness) and {phi}200mm - 9.5mm depth (1/4thickness), were made on a surface of a mock-up: carbon steel plate, 38mm thickness, 2,000mm length, 1000mm width. The surfaces of the plate were covered with concrete in order to simulate liners embedded in concrete. As a result of the examinations, the surface SH transducers could detect clearly the echo from the hollows at a distance of 1500mm. We evaluate that the newly made surface SH transducers with three elements have ability of detection of defects such as corrosion on the liners embedded in concrete. (author)

  1. Development of Inspection Robots for Bridge Cables

    Directory of Open Access Journals (Sweden)

    Hae-Bum Yun

    2013-01-01

    Full Text Available This paper presents the bridge cable inspection robot developed in Korea. Two types of the cable inspection robots were developed for cable-suspension bridges and cable-stayed bridge. The design of the robot system and performance of the NDT techniques associated with the cable inspection robot are discussed. A review on recent advances in emerging robot-based inspection technologies for bridge cables and current bridge cable inspection methods is also presented.

  2. Development of inspection robots for bridge cables.

    Science.gov (United States)

    Yun, Hae-Bum; Kim, Se-Hoon; Wu, Liuliu; Lee, Jong-Jae

    2013-01-01

    This paper presents the bridge cable inspection robot developed in Korea. Two types of the cable inspection robots were developed for cable-suspension bridges and cable-stayed bridge. The design of the robot system and performance of the NDT techniques associated with the cable inspection robot are discussed. A review on recent advances in emerging robot-based inspection technologies for bridge cables and current bridge cable inspection methods is also presented.

  3. New techniques provide low-cost X-ray inspection of highly attenuating materials

    International Nuclear Information System (INIS)

    Stupin, D.M.; Mueller, K.H.; Viskoe, D.A.; Howard, B.; Poland, R.W.; Schneberk, D.; Dolan, K.; Thompson, K.; Stoker, G.

    1995-01-01

    As a result of an arms reduction treaty between the United States and the Russian Federation, both countries will each be storing over 40,000 containers of plutonium. To help detect any deterioration of the containers and prevent leakage, the authors are designing a digital radiography and computed tomography system capable of handling this volume reliably, efficiently, and at a lower cost. The materials to be stored have very high x-ray attenuations, and, in the past, were inspected using 1- to 24-MV x-ray sources. This inspection system, however, uses a new scintillating (Lockheed) glass and an integrating CCD camera. Preliminary experiments show that this will permit the use of a 450-kV x-ray source. This low-energy system will cost much less than others designed to use a higher-energy x-ray source because it will require a less expensive source, less shielding, and less floor space. Furthermore, they can achieve a tenfold improvement in spatial resolution by using their knowledge of the point-spread function of the x-ray imaging system and a least-squares fitting technique

  4. Innovative Ultrasonic Techniques for Inspection and Monitoring of Large Concrete Structures

    Directory of Open Access Journals (Sweden)

    Niederleithinger E.

    2013-07-01

    Full Text Available Ultrasonic echo and transmission techniques are used in civil engineering on a regular basis. New sensors and data processing techniques have lead to many new applications in the structural investigation as well as quality control. But concrete structures in the nuclear sector have special features and parameters, which pose problems for the methods and instrumentation currently available, e.g. extreme thickness, dense reinforcement, steel liners or special materials. Several innovative ultrasonic techniques have been developed to deal with these issues at least partly in lab experiments and pilot studies. Modern imaging techniques as multi-offset SAFT have been used e. g. to map delaminations. Thick concrete walls have successfully been inspected, partly through a steel liner. Embedded ultrasonic sensors have been designed which will be used in monitoring networks of large concrete structures above and below ground. In addition, sensitive mathematical methods as coda wave interferometry have been successfully evaluated to detect subtle changes in material properties. Examples of measurements and data evaluation are presented.

  5. Integrating design and production planning with knowledge-based inspection planning system

    International Nuclear Information System (INIS)

    Abbasi, Ghaleb Y.; Ketan, Hussein S.; Adil, Mazen B.

    2005-01-01

    In this paper an intelligent environment to integrate design and inspection earlier to the design stage. A hybrid knowledge-based approach integrating computer-aided design (CAD) and computer-aided inspection planning (CAIP) was developed, thereafter called computer-aided design and inspection planning (CADIP). CADIP was adopted for automated dimensional inspection planning. Critical functional features were screened based on certain attributes for part features for inspection planning application. Testing the model resulted in minimizing the number of probing vectors associated with the most important features in the inspected prismatic part, significant reduction in inspection costs and release of human labor. In totality, this tends to increase customer satisfaction as a final goal of the developed system. (author)

  6. Experience with the implementation of a risk-based ISI program and inspection qualification

    International Nuclear Information System (INIS)

    Chapman, O.J.V.

    1996-01-01

    Rolls Royce and Associates (RRA) are the Design Authority (DA) for Nuclear Steam Raising Plant (NSRP) used for the Royal Naval Nuclear Fleet. Over the past seven years RRA, with support from the Ministry of Defense, has developed and implemented a risk based in-service inspection (RBISI) strategy for the NSRP. Having used risk as a means of optimizing where to inspect, an inspection qualification (IQ) process has now been put in place to ensure that proposed inspections deliver the expected gains assumed. This qualification process follows very closely that currently being put forward by the European Network on Inspection Qualification (ENIQ)

  7. High performance coated board inspection system based on commercial components

    CERN Document Server

    Barjaktarovic, M; Radunovic, J

    2007-01-01

    This paper presents a vision system for defect (fault) detection on a coated board developed using three industrial firewire cameras and a PC. Application for image processing and system control was realized with the LabView software package. Software for defect detection is based on a variation of the image segmentation algorithm. Standard steps in image segmentation are modified to match the characteristics of defects. Software optimization was accomplished using SIMD (Single Instruction Multiple Data) technology available in the Intel Pentium 4 processors that provided real time inspection capability. System provides benefits such as: improvement in production process, higher quality of delivered coated board and reduction of waste. This was proven during successful exploitation of the system for more than a year.

  8. Automated visual inspection system based on HAVNET architecture

    Science.gov (United States)

    Burkett, K.; Ozbayoglu, Murat A.; Dagli, Cihan H.

    1994-10-01

    In this study, the HAusdorff-Voronoi NETwork (HAVNET) developed at the UMR Smart Engineering Systems Lab is tested in the recognition of mounted circuit components commonly used in printed circuit board assembly systems. The automated visual inspection system used consists of a CCD camera, a neural network based image processing software and a data acquisition card connected to a PC. The experiments are run in the Smart Engineering Systems Lab in the Engineering Management Dept. of the University of Missouri-Rolla. The performance analysis shows that the vision system is capable of recognizing different components under uncontrolled lighting conditions without being effected by rotation or scale differences. The results obtained are promising and the system can be used in real manufacturing environments. Currently the system is being customized for a specific manufacturing application.

  9. A study on non-contact ultrasonic technique for on-line inspection of CFRP

    International Nuclear Information System (INIS)

    Lee, Seung-Joon; Park, Won-Su; Lee, Joon-Hyun; Byun, Joon-Hyung

    2007-01-01

    The advantages of carbon fiber reinforced plastic materials (CFRP) are: they are light structure materials, they have corrosion resistance, and higher specific strength and elasticity. The recently developed 3-dimentional fiber placement system is able to produce a more complex and various shaped structures due to less limitations of a product shape according to the problem in conventional fabrication process. This fiber placement system stacks the narrow prepreg tape on the mold according to the designed sequence and thickness. Non-destructive evaluation was rquired for these composites to evaluate changes in strength caused by defects such as delamination and porosity. Additionally, the expectent quality should be satisfied for the high cost fabrication process using the fiber placement system. Therefore, an on line non-destructive evaluation system is required and real-time complement is needed when the defects are detected [1]. Defect imaging by the ultrasonic C-scan method is a useful technique for defect detection in CFRP. However, the conventional ultrasonic C-scan technique cannot be applied during the fabrication process because the test piece should be immersed into the water. Therefore, non-contact ultrasonic techniques should be applied during the fabricating process. For the development of non-contact ultrasonic techniques available in non-destructive evaluation of CFRP, a recent laser-generated ultrasonic technique and an air-coupled transducer that transmit and receive ultrasounds in the air are studied [2-3]. In this study, generating and receiving techniques of laser-generated ultrasound and the characteristics of received signals upon the internal defects of CFRO were studied for non-contact inspection

  10. Inspection with non destructive assay techniques of the aluminium coating of the TRIGA Mark III reactor vat

    International Nuclear Information System (INIS)

    Reyes A, A.I.; Gonzalez M, A.; Castaneda J, G.; Rivera M, H.; Sandoval G, I.

    2001-01-01

    In June 2000, the Reactor Department assigned to the Scientific Research Direction of the National Institute of Nuclear Research requested to the Non-destructive Assays Laboratory (LEND), assigned to the Materials Science Management, the inspection and measurement of thickness of the aluminium coating (liner) of the TRIGA Mark III reactor vat with non-destructive assay techniques, due to that the aluminium coating is exposed mainly to undergo slimming on its back side due to corrosion phenomena. Activity that was able to be carried out from april until august 2001. It is worth pointing out that this type of inspection with these techniques was realized by first time. The non-destructive assays (NDA) are techniques which use indirect physical methods for inspecting the sanitation of components in process or in service, for detect lack of continuity or defects which affect their quality or usefulness. The application of those do not alter the physical, chemical, mechanical or dimensional properties of the part subject of inspection. The results of the application of the ultrasound inspection techniques, industrial radiography and penetrating liquids are presented. (Author)

  11. Use of the cylindrically guided wave technique for the inspection of stud bolts, valve stems and pump shafts

    International Nuclear Information System (INIS)

    Light, G.M.; Bloom, E.A.; Ruescher, E.H.; Lui, S.N.

    1989-01-01

    Over the last several years, nuclear power plants have expressed concern about failures of bolting, valve stems, and pump shafts. This paper reports on the development of an ultrasonic technique to inspect these components. The authors have successfully demonstrated the cylindrically guided wave technique (CGWT) on a wide range of stud bolts. The CGWT employs zero-degree longitudinal waves constrained to travel within the boundary of the cylindrically shaped components during inspection. Theoretically explained, mode conversion occurs because the ultrasonic wave is guided down the length of the component. These mode-converted signals are dependent upon the diameter of the component under inspection and the longitudinal- and shear-wave velocities of the component material. This technique has also been successfully used on valve stems in the field. The geometry of the valve stem is very similar to that of the stud bolt

  12. New approach for risk based inspection of H2S based Process Plants

    International Nuclear Information System (INIS)

    Vinod, Gopika; Sharma, Pavan K.; Santosh, T.V.; Hari Prasad, M.; Vaze, K.K.

    2014-01-01

    Highlights: • Study looks into improving the consequence evaluation in risk based inspection. • Ways to revise the quantity factors used in qualitative approach. • New approach based on computational fluid dynamics along with probit mathematics. • Demonstrated this methodology along with a suitable case study for the said issue. - Abstract: Recent trend in risk informed and risk based approaches in life management issues have certainly put the focus on developing estimation methods for real risk. Idea of employing risk as an optimising measure for in-service inspection, termed as risk based inspection, was accepted in principle from late 80s. While applying risk based inspection, consequence of failure from each component needs to be assessed. Consequence evaluation in a Process Plant is a crucial task. It may be noted that, in general, the number of components to be considered for life management is very large and hence the consequence evaluation resulting from their failures (individually) is a laborious task. Screening of critical components is usually carried out using simplified qualitative approach, which primarily uses influence factors for categorisation. This necessitates logical formulation of influence factors and their ranges with a suitable technical basis for acceptance from regulators. This paper describes application of risk based inspection for H 2 S based Process Plant along with the approach devised for handling the influence factor related to the quantity of H 2 S released

  13. Development of NDT techniques for the inspection of WSGHWR pressure tubes

    International Nuclear Information System (INIS)

    Gray, B.S.; Highmore, P.J.; Rudlin, J.R.; Cooper, A.G.

    1979-01-01

    The fuel for the Steam Generating Heavy Water Reactor at Winfrith Heath is contained in vertical Zircaloy pressure tubes and is cooled by boiling light water. This paper describes the development of NDT techniques for the inservice examination of the pressure tubes to provide continuing assurance of the absence of axial crack-like defects. The resultant equipment has to operate in water-filled tubes in the presence of the radiation field due to the irradiated fuel elements in adjacent tubes. Also, a layer of surface oxide on the inside of the tubes has been found to significantly affect the behaviour of a prototype inspection device. To provide adequate sensitivity in these conditions, without the occurrence of unnecessary spurious indications, a combination of techniques has been developed. This involves the use of ultrasonics in both pulse-echo and 'pitch and catch' mode together with a single frequency eddy current technique. Laboratory work using artificial defects is described and also how the development programme was modified to accommodate the results of in-reactor tests using a prototype device. Reference is also made to the development of CCTV equipment to provide a supplementary visual examination. (author)

  14. SIIA: a knowledge-based assistant for the SAFT ultrasonic inspection system(a)

    International Nuclear Information System (INIS)

    Melton, R.B.; Doctor, S.R.; Taylor, T.T.; Badalamente, R.V.

    1987-01-01

    SIIA(b) is a knowledge-based system designed to assist in making the operation of the Synthetic Aperture Focussing Technique (SAFT) Ultrasonic Inspection System more reliable and efficient. This paper reports on their effort to develop a prototype version of SIIA to demonstrate the feasibility of using knowledge-based systems in nondestructive evaluation (NDE). The first section of the paper describes the structure of the problem and their conceptual design of the knowledge-based system. The next section describes the current state of the prototype SIIA system and relates some of their experiences in developing the system. The final section discusses their plans for future development of SIIA and the implications of this type of system for other NDE techniques and applications

  15. Feature-based tolerancing for intelligent inspection process definition

    International Nuclear Information System (INIS)

    Brown, C.W.

    1993-07-01

    This paper describes a feature-based tolerancing capability that complements a geometric solid model with an explicit representation of conventional and geometric tolerances. This capability is focused on supporting an intelligent inspection process definition system. The feature-based tolerance model's benefits include advancing complete product definition initiatives (e.g., STEP -- Standard for Exchange of Product model dam), suppling computer-integrated manufacturing applications (e.g., generative process planning and automated part programming) with product definition information, and assisting in the solution of measurement performance issues. A feature-based tolerance information model was developed based upon the notion of a feature's toleranceable aspects and describes an object-oriented scheme for representing and relating tolerance features, tolerances, and datum reference frames. For easy incorporation, the tolerance feature entities are interconnected with STEP solid model entities. This schema will explicitly represent the tolerance specification for mechanical products, support advanced dimensional measurement applications, and assist in tolerance-related methods divergence issues

  16. Improved plant availability by advanced condition based inspections

    International Nuclear Information System (INIS)

    Hulshof, Harry J.M.; Noteboom, Jan W.; Welberg, Paul G.M.; Bruijn, Leo E.

    2004-01-01

    An industrial plant has to operate safely, reliably and efficiently at the lowest possible cost. Plant availability plays an important role regarding economic life optimisation. Industrial installations that are under pressure and are operating at high temperatures have a limited life due to creep and fatigue. It is, therefore, of critical importance to know the location of any possible weak spots in the installation. To avoid safety risks, unplanned plant shutdown and, as a consequence, high costs for unavailability, cycling and repair, periodic inspections and strain measurements are recommended. A Speckle Image Correlation Analysis (SPICA) system enables on-stream measurement of deformation due to creep in critical areas like the heat-affected zone in welds. Plant management and operators use the strain measurements to take action when necessary and, consequently, prevent failures. In those plants that have been provided with SPICA-technology for some years plant availability has improved significantly as a result. Another important development for yielding improved availability concerns steam drums. During some 20 years, KEMA has been performing automated ultrasonic steam drum inspections from outside. The Dutch authorities accepted this methodology in this period as an alternative (rather than an addition) after several pilot projects. An advantage of this inspection methodology is the possibility to record of the inspection results and possibility of thus trending these data. The resulting reduction of through time appeared a major benefit for plant owners. Since the authorities adopted the RBI approach during the last 10 years, another advantage of the inspection methodology became apparent: complete scanning and recording of the inspection data of circumferential and longitudinal (butt and fillet) welds, inspection of nozzle welds and inner radius as well as corrosion mapping has been covering all higher risk areas in these drums. This enhanced inspection

  17. Improved plant availability by advanced condition based inspections

    Energy Technology Data Exchange (ETDEWEB)

    Hulshof, Harry J.M.; Noteboom, Jan W; Welberg, Paul G.M.; Bruijn, Leo E

    2004-06-01

    An industrial plant has to operate safely, reliably and efficiently at the lowest possible cost. Plant availability plays an important role regarding economic life optimisation. Industrial installations that are under pressure and are operating at high temperatures have a limited life due to creep and fatigue. It is, therefore, of critical importance to know the location of any possible weak spots in the installation. To avoid safety risks, unplanned plant shutdown and, as a consequence, high costs for unavailability, cycling and repair, periodic inspections and strain measurements are recommended. A Speckle Image Correlation Analysis (SPICA) system enables on-stream measurement of deformation due to creep in critical areas like the heat-affected zone in welds. Plant management and operators use the strain measurements to take action when necessary and, consequently, prevent failures. In those plants that have been provided with SPICA-technology for some years plant availability has improved significantly as a result. Another important development for yielding improved availability concerns steam drums. During some 20 years, KEMA has been performing automated ultrasonic steam drum inspections from outside. The Dutch authorities accepted this methodology in this period as an alternative (rather than an addition) after several pilot projects. An advantage of this inspection methodology is the possibility to record of the inspection results and possibility of thus trending these data. The resulting reduction of through time appeared a major benefit for plant owners. Since the authorities adopted the RBI approach during the last 10 years, another advantage of the inspection methodology became apparent: complete scanning and recording of the inspection data of circumferential and longitudinal (butt and fillet) welds, inspection of nozzle welds and inner radius as well as corrosion mapping has been covering all higher risk areas in these drums. This enhanced inspection

  18. Development of Pipe Inspection Gauge (PIG) for leak detection in buried pipelines using radiotracer technique

    International Nuclear Information System (INIS)

    Pendharkar, A.S.; Sharma, V.K.; Pant, H.J.; Singh, Gursharan

    2004-01-01

    This paper discusses the development of a portable battery operated radioisotope based pipeline inspection gauge( PIG) for detection and location of leaks as well as to examine the condition of the underground pipelines. The system consists of a scintillation detector, power supply for detector and other electronic circuits. Pulse processing amplifier data acquisition system, readout unit and software to transfer data to computer for further processing. The microcontroller based pig is very useful in a field in an underground pipeline of 6 inch diameter and above. The battery operated pig system developed indigenously is rugged and portable with data storage capacity up to 20 hours. The system was tested under simulated leak conditions and field trials are being planned. (author)

  19. Risk Based Inspection Methodology and Software Applied to Atmospheric Storage Tanks

    Science.gov (United States)

    Topalis, P.; Korneliussen, G.; Hermanrud, J.; Steo, Y.

    2012-05-01

    A new risk-based inspection (RBI) methodology and software is presented in this paper. The objective of this work is to allow management of the inspections of atmospheric storage tanks in the most efficient way, while, at the same time, accident risks are minimized. The software has been built on the new risk framework architecture, a generic platform facilitating efficient and integrated development of software applications using risk models. The framework includes a library of risk models and the user interface is automatically produced on the basis of editable schemas. This risk-framework-based RBI tool has been applied in the context of RBI for above-ground atmospheric storage tanks (AST) but it has been designed with the objective of being generic enough to allow extension to the process plants in general. This RBI methodology is an evolution of an approach and mathematical models developed for Det Norske Veritas (DNV) and the American Petroleum Institute (API). The methodology assesses damage mechanism potential, degradation rates, probability of failure (PoF), consequence of failure (CoF) in terms of environmental damage and financial loss, risk and inspection intervals and techniques. The scope includes assessment of the tank floor for soil-side external corrosion and product-side internal corrosion and the tank shell courses for atmospheric corrosion and internal thinning. It also includes preliminary assessment for brittle fracture and cracking. The data are structured according to an asset hierarchy including Plant, Production Unit, Process Unit, Tag, Part and Inspection levels and the data are inherited / defaulted seamlessly from a higher hierarchy level to a lower level. The user interface includes synchronized hierarchy tree browsing, dynamic editor and grid-view editing and active reports with drill-in capability.

  20. Electrical Distribution System Functional Inspection (EDSFI) data base program

    International Nuclear Information System (INIS)

    Gautam, A.

    1993-01-01

    This document describes the organization, installation procedures, and operating instructions for the database computer program containing inspection findings from the US Nuclear Regulatory Commission's (NRC's) Electrical Distribution System Functional Inspections (EDSFIs). The program enables the user to search and sort findings, ascertain trends, and obtain printed reports of the findings. The findings include observations, unresolved issues, or possible deficiencies in the design and implementation of electrical distribution systems in nuclear plants. This database will assist those preparing for electrical inspections, searching for deficiencies in a plant, and determining the corrective actions previously taken for similar deficiencies. This database will be updated as new EDSFIs are completed

  1. Reliability-based inspection planning of 20MW offshore wind turbine jacket

    DEFF Research Database (Denmark)

    Gintautas, Tomas; Sørensen, John Dalsgaard

    2018-01-01

    This paper presents the application of a risk and reliability based inspection planning framework (RBI) for the InnWind 20MW reference wind turbine jacket sub-structure. A detailed fracture mechanics based fatigue crack growth model is developed and used as basis to derive optimal inspection plans...

  2. Reliability Assessment and Reliability-Based Inspection and Maintenance of Offshore Wind Turbines

    DEFF Research Database (Denmark)

    Ramírez, José G. Rangel; Sørensen, John Dalsgaard

    2009-01-01

    Probabilistic methodologies represent an important tool to identify the suitable strategy to inspect and deal with the deterioration in structures such as offshore wind turbines (OWT). Reliability based methods such as Risk Based Inspection (RBI) planning may represent a proper methodology to opt...

  3. Sandy Damage Estimates Based on FEMA IA Registrant Inspection Data

    Data.gov (United States)

    Department of Housing and Urban Development — A FEMA housing inspection for renters is used to assess personal property loss and for owners to assess damage to their home as well as personal property. This...

  4. Seed-a distributed data base architecture for global management of steam-generator inspection data

    International Nuclear Information System (INIS)

    Soon Ju Kang; Yu Rak Choi; Hee Gon Woo; Seong Su Choi

    1996-01-01

    This paper deals with a data management system - called SEED (Steam-generator Eddy-current Expert Database) for global handling of SG (steam generator) tube inspection data in nuclear power plants. The SEED integrates all stages in SG tube inspection process and supports all data such as raw eddy current data, inspection history data, SG tube information, etc. SEED implemented under client/server computing architecture for supporting LAN/WAN based graphical user interface facilities using WWW programming tools. (author)

  5. Towards formalization of inspection using petrinets

    International Nuclear Information System (INIS)

    Javed, M.; Naeem, M.; Bahadur, F.; Wahab, A.

    2014-01-01

    Achieving better quality software has always been a challenge for software developers. Inspection is one of the most efficient techniques, which ensure the quality of software during its development. To the best of our knowledge, current inspection techniques are not realized by any formal approach. In this paper, we propose an inspection technique, which is not only backed by the formal mathematical semantics of Petri nets, but also supports inspecting concurrent processes. We also use a case study of an agent based distributed processing system to demonstrate the inspection of concurrent processes. (author)

  6. Pressure vessel inspection criteria based on fitness-for-purpose assessment

    International Nuclear Information System (INIS)

    Grover, J.L.; Cipolla, R.C.

    1985-01-01

    The paper on pressure vessel inspection investigates the methodology required to establish an inspection strategy consistent with fracture mechanics analysis, i.e. to define allowable flaw sizes based on location within the vessel. The methodology is demonstrated using a sample problem for a typical pressurised water reactor pressure vessel, and shows the impact of certain assumptions on the inspection strategy. The results indicate that the flaw size varies with the shape of the assumed residual stress field and the through-thickness location. Also in general, the fracture mechanics evaluation allows flaws much larger than are allowed by the inspection acceptance criteria. (UK)

  7. SmartInspect: Smart Contract Inspection Technical Report

    OpenAIRE

    Bragagnolo , Santiago; Rocha , Henrique ,; Denker , Marcus; Ducasse , Stéphane

    2017-01-01

    Smart contracts are embedded procedures stored with the data they act upon. Debugging deployed Smart Contracts is a difficult task since once deployed, the code cannot be reexecuted and inspecting a simple attribute is not easily possible because data is encoded. In this technical report, we present SmartInspect to address the lack of inspectability of a deployed contract. Our solution analyses the contract state by using decompilation techniques and a mirror-based architecture to represent t...

  8. Remote Impedance-based Loose Bolt Inspection Using a Radio-Frequency Active Sensing Node

    Energy Technology Data Exchange (ETDEWEB)

    Park, Seung Hee; Yun, Chung Bang [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of); Inman, Daniel J. [Virginia Polytechnic Institute and State University, Virginia (United States)

    2007-06-15

    This paper introduces an active sensing node using radio-frequency (RF) telemetry. This device has brought the traditional impedance-based structural health monitoring (SHM) technique to a new paradigm. The RF active sensing node consists of a miniaturized impedance measuring device (AD5933), a microcontroller (ATmega128L), and a radio frequency (RF) transmitter (XBee). A macro-fiber composite (MFC) patch interrogates a host structure by using a self-sensing technique of the miniaturized impedance measuring device. All the process including structural interrogation, data acquisition, signal processing, and damage diagnostic is being performed at the sensor location by the microcontroller. The RF transmitter is used to communicate the current status of the host structure. The feasibility of the proposed SHM strategy is verified through an experimental study inspecting loose bolts in a bolt-jointed aluminum structure

  9. Remote Impedance-based Loose Bolt Inspection Using a Radio-Frequency Active Sensing Node

    International Nuclear Information System (INIS)

    Park, Seung Hee; Yun, Chung Bang; Inman, Daniel J.

    2007-01-01

    This paper introduces an active sensing node using radio-frequency (RF) telemetry. This device has brought the traditional impedance-based structural health monitoring (SHM) technique to a new paradigm. The RF active sensing node consists of a miniaturized impedance measuring device (AD5933), a microcontroller (ATmega128L), and a radio frequency (RF) transmitter (XBee). A macro-fiber composite (MFC) patch interrogates a host structure by using a self-sensing technique of the miniaturized impedance measuring device. All the process including structural interrogation, data acquisition, signal processing, and damage diagnostic is being performed at the sensor location by the microcontroller. The RF transmitter is used to communicate the current status of the host structure. The feasibility of the proposed SHM strategy is verified through an experimental study inspecting loose bolts in a bolt-jointed aluminum structure

  10. Neutron diffraction tomography: a unique, 3D inspection technique for crystals using an intensifier TV system

    International Nuclear Information System (INIS)

    Davidson, J.B.; Case, A.L.

    1978-01-01

    The application of phosphor-intensifier-TV techniques to neutron topography and tomography of crystals is described. The older, analogous x-ray topography using wavelengths approximately 1.5A is widely used for surface inspection. However, the crystal must actually be cut in order to see diffraction anomalies beneath the surface. Because 1.5-A thermal neutrons are highly penetrating, much larger and thicker specimens can be used. Also, since neutrons have magnetic moments, they are diffracted by magnetic structures within crystals. In neutron volume topography, the entire crystal or a large part of it is irradiated, and the images obtained are superimposed reflections from the total volume. In neutron tomography (or section topography), a collimated beam irradiates a slice (0.5 to 10 mm) of the crystal. The diffracted image is a tomogram from this part only. A series of tomograms covering the crystal can be taken as the specimen is translated in steps across the narrow beam. Grains, voids, twinning, and other defects from regions down to 1 mm in size can be observed and isolated. Although at present poorer in resolution than the original neutron and film methods, the TV techniques are much faster and, in some cases, permit real-time viewing. Two camera systems are described: a counting camera having a 150 mm 6 Li-ZnS screen for low-intensity reflections which are integrated in a digital memory, and a 300-mm system using analog image storage. Topographs and tomograms of several crystals ranging in size from 4 mm to 80 mm are shown

  11. SEM-based characterization techniques

    International Nuclear Information System (INIS)

    Russell, P.E.

    1986-01-01

    The scanning electron microscope is now a common instrument in materials characterization laboratories. The basic role of the SEM as a topographic imaging system has steadily been expanding to include a variety of SEM-based analytical techniques. These techniques cover the range of basic semiconductor materials characterization to live-time device characterization of operating LSI or VLSI devices. This paper introduces many of the more commonly used techniques, describes the modifications or additions to a conventional SEM required to utilize the techniques, and gives examples of the use of such techniques. First, the types of signals available from a sample being irradiated by an electron beam are reviewed. Then, where applicable, the type of spectroscopy or microscopy which has evolved to utilize the various signal types are described. This is followed by specific examples of the use of such techniques to solve problems related to semiconductor technology. Techniques emphasized include: x-ray fluorescence spectroscopy, electron beam induced current (EBIC), stroboscopic voltage analysis, cathodoluminescnece and electron beam IC metrology. Current and future trends of some of the these techniques, as related to the semiconductor industry are discussed

  12. Advanced inspection technology for non intrusive inspection (NII) program

    International Nuclear Information System (INIS)

    Zamir Mohamed Daud

    2003-01-01

    In the current economic environment, plants and facilities are under pressure to introduced cost saving as well as profit maximising measures. Among the many changes in the way things are run is a move towards Risk Based Inspection (RBI), with an emphasis on longer operating periods between shutdowns as well as to utilise components to their maximum capability. Underpinning and RBI program requires good data from an effective online inspections program, which would not require the shutdown of critical components. One methodology of online inspection is known as Non Intrusive Inspection (NII), an inspection philosophy with the objective of replacing internal inspection of a vessel by doing Non Destructive Testing (NDT) and inspections externally. To this end, a variety of advanced NDT techniques are needed to provide accurate online measurements. (Author)

  13. In service inspection for Superphenix vessels development of ultrasonic techniques available at high temperature

    International Nuclear Information System (INIS)

    Gondard, C.

    1983-12-01

    The main and safety vessels of SUPERPHENIX 1 were designed to allow in-service inspections. The remote controlled inspection device MIR was developped for this purpose. The ultrasonic examination has required the development of all new transducers fitted with severe operating conditions prevailing in intervessels interval. A list of problems to be resolved and technological solutions which were found is given. Measurements of acoustical properties on actual probes are compared with theoretical values. It appears that concordance is good and that an in-service inspection using high temperature transducers is possible with a good spatial resolution and signal to noise ratio

  14. Regulatory requirements related to risk-based inspection and maintenance

    International Nuclear Information System (INIS)

    Schroeder, H.C.; Kauer, R.

    2003-01-01

    By asking the question why new inspection and maintenance strategies have to be developed one can often be made aware that there is always a continue demand for cost reduction and optimisation. In this framework, general trends involving staff reduction, outsourcing, benchmarking etc. can often be observed nearly everywhere. Since inspection and maintenance are amongst the few cost factors, which could be actively influenced in the short term, and in combination with the recent regulatory fundamental changes (e.g. PED) yielding to considerably greater responsibilities for the operator of a plant, also the demand for documentation and comprehensibility of measures will increase. (orig.)

  15. Inspection planning

    International Nuclear Information System (INIS)

    Korosec, D.; Levstek, M.F.

    2001-01-01

    Slovenian Nuclear Safety Administration (SNSA) division of nuclear and radiological safety inspection has developed systematic approach to their inspections. To be efficient in their efforts regarding regular and other types of inspections, in past years, the inspection plan has been developed. It is yearly based and organized on a such systematic way, that all areas of nuclear safety important activities of the licensee are covered. The inspection plan assures appropriate preparation for conducting the inspections, allows the overview of the progress regarding the areas to be covered during the year. Depending on the licensee activities and nature of facility (nuclear power plant, research reactor, radioactive waste storage, others), the plan has different levels of intensity of inspections and also their frequency. One of the basic approaches of the plan is to cover all nuclear and radiological important activities on such way, that all regulatory requests are fulfilled. In addition, the inspection plan is a good tool to improve inspection effectiveness based on previous experience and allows to have the oversight of the current status of fulfillment of planned inspections. Future improvement of the plan is necessary in the light of newest achievements on this field in the nuclear world, that means, new types of inspections are planned and will be incorporated into plan in next year.(author)

  16. Feature-Learning-Based Printed Circuit Board Inspection via Speeded-Up Robust Features and Random Forest

    Directory of Open Access Journals (Sweden)

    Eun Hye Yuk

    2018-06-01

    Full Text Available With the coming of the 4th industrial revolution era, manufacturers produce high-tech products. As the production process is refined, inspection technologies become more important. Specifically, the inspection of a printed circuit board (PCB, which is an indispensable part of electronic products, is an essential step to improve the quality of the process and yield. Image processing techniques are utilized for inspection, but there are limitations because the backgrounds of images are different and the kinds of defects increase. In order to overcome these limitations, methods based on machine learning have been used recently. These methods can inspect without a normal image by learning fault patterns. Therefore, this paper proposes a method can detect various types of defects using machine learning. The proposed method first extracts features through speeded-up robust features (SURF, then learns the fault pattern and calculates probabilities. After that, we generate a weighted kernel density estimation (WKDE map weighted by the probabilities to consider the density of the features. Because the probability of the WKDE map can detect an area where the defects are concentrated, it improves the performance of the inspection. To verify the proposed method, we apply the method to PCB images and confirm the performance of the method.

  17. Approaching application of risk-based inspection to ASME code section XI

    International Nuclear Information System (INIS)

    Hedden, Owen F.

    1995-01-01

    This paper will describe current efforts within the ASME Boiler and Pressure Vessel Committee's Subcommittee on Nuclear Inservice Inspection to introduce risk-based technology to optimize inservice inspection of nuclear power plants. The subcommittee is responsible for the content of ASME Boiler and Pressure Vessel Code Section XI, Rules for Inservice Inspection of Nuclear Power Plant Components. The paper will first provide the historical background for the inspection program currently in Section XI. It will then describe the development of new technology through the ASME Center for Research and Technology Development program. Next, the work now going on in two of the groups under the Section XI committee will be described in detail. Each of these two efforts is directed toward the application of new risk-based inspection technology to nuclear piping systems. Finally, the directions of additional research and applications of the technology will be discussed. (author)

  18. Risk-based optimization of pipe inspections in large underground networks with imprecise information

    International Nuclear Information System (INIS)

    Mancuso, A.; Compare, M.; Salo, A.; Zio, E.; Laakso, T.

    2016-01-01

    In this paper, we present a novel risk-based methodology for optimizing the inspections of large underground infrastructure networks in the presence of incomplete information about the network features and parameters. The methodology employs Multi Attribute Value Theory to assess the risk of each pipe in the network, whereafter the optimal inspection campaign is built with Portfolio Decision Analysis (PDA). Specifically, Robust Portfolio Modeling (RPM) is employed to identify Pareto-optimal portfolios of pipe inspections. The proposed methodology is illustrated by reporting a real case study on the large-scale maintenance optimization of the sewerage network in Espoo, Finland. - Highlights: • Risk-based approach to optimize pipe inspections on large underground networks. • Reasonable computational effort to select efficient inspection portfolios. • Possibility to accommodate imprecise expert information. • Feasibility of the approach shown by Espoo water system case study.

  19. Development of flexural vibration inspection techniques to rapidly assess the structural health of timber bridge systems

    Science.gov (United States)

    Xiping Wang; James P. Wacker; Robert J. Ross; Brian K. Brashaw; Robert Vatalaro

    2005-01-01

    This paper describes an effort to develop a global dynamic testing technique for evaluating the overall stiffness of timber bridge superstructures. A forced vibration method was used to measure the natural frequency of single-span timber bridges in the laboratory and field. An analytical model based on simple beam theory was proposed to represent the relationship...

  20. RBI - Risk Based Inspection: new technologies and methods applied to inspections of FPSO (Floating Production, Storage and Offloading Vessel) hull; IBR - Inspecao Baseada em Risco: novas tecnologias e metodos aplicados as inspecoes de casco de FPSOs

    Energy Technology Data Exchange (ETDEWEB)

    Farias, Bruno de; Figueiredo, Eduardo; Luiz, Marcio [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil); Meurer, Gustavo; Duarte, Romulo; Oliveira, Thais; Krzonkalla, Viviane [ABS Consulting, Rio de Janeiro, RJ (Brazil)

    2008-07-01

    With the aging of the FPSO's, which are fundamental to the operation Offshore, better techniques and technologies must be applied to assess more accurately the actual efficiency and structural conditions of producing unit. With the emergence of new engineering techniques and equipment and methods of structural inspection, is now possible to use these new technologies to better manage risk and reliability of the structure of the FPSO, with that, the inspections and methods are more rational and efficient. The Risk-Based Inspection is the tool for monitoring operation of industrial plants with systemic use of technology in conjunction with risk analysis and reliability. His concept is applicable to various branches of industry. The companies began their implementation of oil by refineries. The group of ABS Consulting with PETROBRAS has been developing and implementing these new technologies in inspections of hulls of FPSO's. Applied successfully in the units of the Campos basin, these methods are used by the group of Risk-Based Inspection to improve the efficiency of all the steps involved with the structural integrity of the unit. (author)

  1. Development of nondestructive evaluation techniques for DAM inspection. Progress report, January 1995 through August 1997

    Energy Technology Data Exchange (ETDEWEB)

    Brown, A. E.; Thomas, G.H.

    1997-09-04

    The Lawrence Livermore National Laboratory has concluded a two and a half year study on the development of an ultrasonic inspection system to inspect post stressed steel tendons on dams and flood gates. The inspection systems were part of a program for the California Department of Water Resources. The effort included the identification of the location and amount of corrosion damage to the tendons, identification of the cause of corrosion, and the technology for inhibiting corrosion. Several NDE methods for inspecting and quantifying damage to steel reinforced concrete water pipes were investigated and presented to the DWR for their consideration. The additional methods included Ground Penetrating RADAR, Electro- Potential Measurements, Infrared Technology, Pipe Inspection Crawlers (designed to travel inside pipelines and simultaneously report on the pipe condition as viewed by ultrasonic methods and video cameras from within the pipeline.) Reference to consultants hired by LLNL for similar on-site corrosion inspections were given to the DWR. The LLNL research into industries that have products to prevent corrosion resulted in the identification of an Innsbruck, Austria, company. This company claims to have products to permanently protect post- or pre-stressed tendons. The caveat is that the tendon protection system must be installed when the tendons are installed because no retrofit is available. Corrosion mitigation on the steel reinforcements surrounding the concrete was addressed through active and passive cathodic protection schemes. The combination of corrosion and erosion were addressed during consideration for the inspection of water-pump impeller-blades that are used in the three stage, million horsepower, pumping stations at Edmunston.

  2. Reducing uncertainty in wind turbine blade health inspection with image processing techniques

    Science.gov (United States)

    Zhang, Huiyi

    Structural health inspection has been widely applied in the operation of wind farms to find early cracks in wind turbine blades (WTBs). Increased numbers of turbines and expanded rotor diameters are driving up the workloads and safety risks for site employees. Therefore, it is important to automate the inspection process as well as minimize the uncertainties involved in routine blade health inspection. In addition, crack documentation and trending is vital to assess rotor blade and turbine reliability in the 20 year designed life span. A new crack recognition and classification algorithm is described that can support automated structural health inspection of the surface of large composite WTBs. The first part of the study investigated the feasibility of digital image processing in WTB health inspection and defined the capability of numerically detecting cracks as small as hairline thickness. The second part of the study identified and analyzed the uncertainty of the digital image processing method. A self-learning algorithm was proposed to recognize and classify cracks without comparing a blade image to a library of crack images. The last part of the research quantified the uncertainty in the field conditions and the image processing methods.

  3. Risk-based priorities for inspection of nuclear pressure boundary components at selected LWRs

    International Nuclear Information System (INIS)

    Vo, T.V.; Simonen, F.A.; Gore, B.F.; Doctor, S.R.; Smith, B.W.

    1990-03-01

    Data from existing probabilistic risk assessments for eight representative nuclear power plants were used to identify and prioritize the most relevant systems to plant safety. The objective was to assess current in-service inspection requirements for pressure boundary systems and components, and to develop recommendations for improvements. This study demonstrates the feasibility of using risk-based methods to develop plant-specific inspection plans. Results for the eight representative plants also indicate generic trends that suggest improvements in current inspection plans now based on priorities set in accordance with code definitions of Class 1, 2, and 3 systems. 2 refs., 4 figs., 5 tabs

  4. Risk-based priorities for inspection of nuclear pressure boundary components at selected LWRs

    International Nuclear Information System (INIS)

    Vo, T.V.; Simonen, F.A.; Gore, B.F.; Doctor, S.R.; Smith, B.W.

    1990-01-01

    Data from existing probabilistic risk assessments for eight representative nuclear power plants were used to identify and prioritize the most relevant systems to plant safety. The objective of this paper is to assess current in-service inspection requirements for pressure boundary systems and components, and to develop recommendations for improvements. This study demonstrates the feasibility of using risk-based methods to develop plant-specific inspection plans. Results for the eight representative plants also indicate generic trends that suggest improvements in current inspection plans now based on priorities set in accordance with code definitions of Class 1, 2, and 3 systems

  5. Qualification of Manual Phased Array Ultrasonic Techniques for Pipe Weld Inspection in Nuclear Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Poirier, J.; Hayes, P.; Vicat, F. [GE Inspection Technologies (United States)

    2011-07-01

    Phasor XS can be used for piping weld inspection in any facilities that use EPRI procedures (example: nuclear power plant in Usa, Japan, ...). Whole pipe range is inspected with 5 probes and 6 wedges: 4 1-dimensional probe for sound wave scanning (different frequency, different apertures); 1 dual matrix probe for LW scanning; there are 3 types of wedges optimized for weld inspection. Weld is scanned in 'Raster Scan', maximum range from 35 up to 80 degrees. Probe selection is defined in the procedure according to pipe diameter, pipe thickness and type of access (single or dual side). We have to note that datasets for dual matrix probe are provided with the procedure because this kind of probe cannot be programmed inside Phasor XS

  6. High-speed potato grading and quality inspection based on a color vision system

    Science.gov (United States)

    Noordam, Jacco C.; Otten, Gerwoud W.; Timmermans, Toine J. M.; van Zwol, Bauke H.

    2000-03-01

    A high-speed machine vision system for the quality inspection and grading of potatoes has been developed. The vision system grades potatoes on size, shape and external defects such as greening, mechanical damages, rhizoctonia, silver scab, common scab, cracks and growth cracks. A 3-CCD line-scan camera inspects the potatoes in flight as they pass under the camera. The use of mirrors to obtain a 360-degree view of the potato and the lack of product holders guarantee a full view of the potato. To achieve the required capacity of 12 tons/hour, 11 SHARC Digital Signal Processors perform the image processing and classification tasks. The total capacity of the system is about 50 potatoes/sec. The color segmentation procedure uses Linear Discriminant Analysis (LDA) in combination with a Mahalanobis distance classifier to classify the pixels. The procedure for the detection of misshapen potatoes uses a Fourier based shape classification technique. Features such as area, eccentricity and central moments are used to discriminate between similar colored defects. Experiments with red and yellow skin-colored potatoes have shown that the system is robust and consistent in its classification.

  7. Design and development of Pc-based TOFD ultrasonic scanning system for welds inspection

    International Nuclear Information System (INIS)

    Suhairy Sani; Mohamad Pauzi Ismai; Muhammad Faiz Mohd Shukri; Amry Amin Abas

    2010-01-01

    This paper describes the design and development of a portable PC-based ultrasonic scanning system for industrial applications. The system which is called TOFD Ultrasonic Scanning System (TOFUSS) is used to create a gray scale imaging techniques are applied to the RF (AC) signal phase and enables weld integrity to be observed in real time. TOFD consists of a separate ultrasonic transmitter and receiver. The Probes are aimed at the same point in the weld volume. The entire weld is flooded with ultrasound allowing inspection of the weld. With a time of flight path, the ultrasonic velocity and the spatial relationship of the two probes, location and height of the defects can be very accurately calculated. The algorithm and complete system were implemented in a computer software developed using Microsoft Visual BASIC 6.0. (author)

  8. NDT method in determining the rate of corrosion applicable to risk based inspection

    International Nuclear Information System (INIS)

    Mohamed Hairul Hasmoni; Mohamad Pauzi Ismail; Ab Razak Hamzah

    2004-01-01

    Corrosion is a major problem in oil and gas industries, refineries and chemical process plants as the equipment is often exposed to corrosive environments or elevated temperature. Important equipment need to operate safely and reliably to avoid injuries to personnel and the public, and to prevent loss time and cost incurred due to loss of production and shutdown. The paper assess the approach in evaluating the technique of non-destructive testing (NDT) using Ultrasonic Testing (UT) in determining the rate of corrosion and remaining life of equipment applicable to Risk Based Inspection (RBI). Methods in determining the corrosion rate are presented using analytical method. Examples and data from MINT chiller water pipeline are presented to illustrate the application of these methods. (Author)

  9. Application of risk based inspection as a part of life management of nuclear power plants

    International Nuclear Information System (INIS)

    Vinod, Gopika; Babar, A.K.; Saraf, R.K.; Kushwaha, H.S.; Venkat Raj, V.

    2002-01-01

    Full text: Risk Informed approach is a systematic effort to improve plant safety in a more efficient manner by distributing the available safety resources depending on the importance to plant safety. This approach has found immense application in various aspects associated with Nuclear Power Plants, including design, manufacturing, operation and regulation. Typical applications of Risk Informed approach are in Technical Specification, In-Service Inspection (ISI) requirements, Motor Operated Valve testing, Configuration Control etc. In order to cater to such variety of Probabilistic Safety Assessment (PSA) based Risk Informed requirements, a software package, 'Risk Monitor' has been developed by the authors. An important application of Risk informed approach that has been undertaken for Indian Pressurised Heavy Water Reactor (IPHWR) is towards Risk Informed In-Service Inspection (RI-ISI). Studies are being conducted to evolve an inspection plan that is optimised to provide effective inspections at the right location with a proper inspection frequency. Using risk informed approach, the identification of system / component for inspection resource allocation is based on the results from Level 1 PSA of a NPP. Even though this methodology can be employed on any of the nuclear components/systems such as mechanical systems, instrumentation, etc., as a starting point, piping has been considered for employing Risk Informed Inspection. Plant risk assessment is modelled through the analysis of Core Damage Frequency (CDF) using PSA models. Risk Informed Inspection program of piping involves the estimation of failure probability or frequency of a piping segment and estimation of consequences of piping failures. ISI program changes could affect the failure probability values of piping and can introduce a change in CDF. These effects can be brought out through the implementation of Risk Informed inspection strategy. Various importance measures like Fussel-Vesely, Birnbaum

  10. In service inspection of pipes based on risk methods; Inspeccion en servicio de tuberias basada en metodos de riesgo

    Energy Technology Data Exchange (ETDEWEB)

    Mendoza G, G.; Viais J, J.; Carmona C, M. [ININ, Centro Nuclear ' Dr. Nabor Carrillo Flores' , Carretera Mexico Toluca, S/N. La Marquesa, Ocoyoacac, Mexico, C. P. 52750 (Mexico)]. e-mail: gmg@nuclear.inin.mx

    2006-07-01

    The politics of the Nuclear Regulatory Commission (by its initials in English NRC) of the United States of America on the use of the Probabilistic Safety Analysis (PSA) in activities of nuclear regulation it foments the use of this analysis technique to improve the decisions making, to reduce the unnecessary work in maintenance aspects, inspection and tests and to improve the regulatory efficiency. The inspection programs in service (ISI by its initials in English) developed by the American Society of Mechanical Engineers (by its initials in English ASME) it has been the one primary mechanism to prove the mechanical equipment in plants of nuclear energy, these programs indeed have been carried out in plants of nuclear energy by more of two decades. Their purpose is to identify the conditions, such as indications of cracks that are precursory of flights and ruptures which violate the integrity principles of the pressure frontier. The inspection in service activities include ultrasonic tests, surface tests and penetrating liquids test, also activities that include the scaffolds construction, removal of insulations and welding polishing. The inspections in service every 18 months during the times outside of service are executed. One of the objectives is to lower the costs of the inspections during the times outside of service and to reduce the exposure to the radiation by part of the personnel during these times out for inspections, while it is increased or it maintains the personnel's safety and the reliability. As part of the methodology a pipe segment is selected for which a fault in any point has the same consequences, being calculated the fault probability of the tube using the dimensions of the segment. In this work the inspection in service methodology is applied based on risk to an aspersion system of low pressure of the Laguna Verde Nucleo electric Central. For this system a reduction in the number of welding to inspect of 103 to only 15 is obtained

  11. Proposal of a radiological protection inspection technique for nuclear medicine facilities

    International Nuclear Information System (INIS)

    Mendes, Leopoldino da Cruz Gouveia; Fonseca, Lea Mirian Barbosa da; Carvalho, Antonio Carlos Pires

    2004-01-01

    The main objective of this study is to implement an impartial and efficient inspection method for a correct and secure use of ionizing radiation in nuclear medicine. The radiological protection model was tested in 113 nuclear medicine services (NMS) all over Brazil, following a biannual analysis schedule (1996, 1998, 2000 and 2002). In the analytical process, we adopted the methodology of assigning different importance levels to each of 82 features, based on the risk factors established by the 'Comissao Nacional de Energia Nuclear' (CNEN) and on the International Atomic Energy Agency (IAEA) recommendations. A feature was considered a radioprotection fault when in nonconformity with the rules mentioned above, and was imparted a grade. The sum of those grades, classified the NMS in one of the three different ranges, as follows: operating without restriction - 100 points and below; operating with restriction - between 100 and 300 points; temporary shutdown - above 300 points. Permission for the second group to carry on operation should be attached to a defined and restricted period of time (6 to 12 months), considered enough for the NMS to solve the problems and submit to a new evaluation. The NMS's classified in the third group are supposed to go back into operation only after compliance with all the pending radioprotection requirements. Until the next regular evaluation, a multiplication factor 2 n was applied to the recalcitrant NMS's, where n is the number of unwilling occurrences. The previous establishment of those items of radioprotection, with their respective grades, excluded subjective and personal values in the judgement and technical evaluation of the institutions. (author)

  12. Development of outdoor luminescence imaging for drone-based PV array inspection

    DEFF Research Database (Denmark)

    Benatto, Gisele Alves dos Reis; Riedel, Nicholas; Thorsteinsson, Sune

    2017-01-01

    This work has the goal to examined experimentally PV module imaging methods under natural light conditions, that will be used in a fast, accurate and automatic drone-based inspection system for PV power plants.......This work has the goal to examined experimentally PV module imaging methods under natural light conditions, that will be used in a fast, accurate and automatic drone-based inspection system for PV power plants....

  13. Intercomparison of techniques for inspection and diagnostics of heavy water reactor pressure tubes. Determination of hydrogen concentration and blister characterization

    International Nuclear Information System (INIS)

    2009-03-01

    Heavy water reactors (HWRs) comprise significant numbers of today's operating nuclear power plants, and more are under construction. Efficient and accurate inspection and diagnostic techniques for various reactor components and systems, especially pressure tubes, are an important factor in ensuring reliable and safe plant operation. To foster international collaboration in the efficient and safe use of nuclear power, the IAEA conducted a Coordinated Research Project (CRP) on Intercomparison of Techniques for HWR Pressure Tube Inspection and Diagnostics. This CRP was carried out within the framework of the IAEA's Technical Working Group on Advanced Technologies for HWRs (the TWG-HWR). The TWG-HWR is a group of experts nominated by their governments and designated by the IAEA to provide advice and to support implementation of IAEA's project on advanced technologies for HWRs. The objective of the CRP was to compare non-destructive inspection and diagnostic techniques, in use and being developed, for structural integrity assessment of HWR pressure tubes. During the first phase of this CRP participants investigated the capability of different techniques to detect and characterize flaws. During the second phase participants collaborated to detect and characterize hydride blisters and to determine the hydrogen concentration in zirconium alloys. The intention was to identify the most effective pressure tube inspection and diagnostic methods and to identify further development needs. The organizations which participated in phase 2 of this CRP are: - Comision Nacional de Energia Atomica (CNEA), Argentina; - Atomic Energy of Canada Ltd. (AECL), Chalk River Laboratories (CRL), Canada; - Bhabha Atomic Research Centre (BARC), India; - Korea Atomic Energy Research Institute (KAERI), Republic of Korea; - National Institute for Research and Development for Technical Physics (NIRDTP), Romania; - Nuclear Non-Destructive Testing Research and Services (NNDT), Romania. IAEA-TECDOC-1499

  14. Bases of technique of sprinting

    Directory of Open Access Journals (Sweden)

    Valeriy Druz

    2015-06-01

    Full Text Available Purpose: to determine the biomechanical consistent patterns of a movement of a body providing the highest speed of sprinting. Material and Methods: the analysis of scientific and methodical literature on the considered problem, the anthropometrical characteristics of the surveyed contingent of sportsmen, the analysis of high-speed shootings of the leading runners of the world. Results: the biomechanical bases of technique of sprinting make dispersal and movement of the general center of body weight of the sportsman on a parabolic curve in a start phase taking into account the initial height of its stay in a pose of a low start. Its further movement happens on a cycloidal trajectory which is formed due to a pendulum movement of the extremities creating the lifting power which provides flight duration more in a running step, than duration of a basic phase. Conclusions: the received biomechanical regularities of technique of sprinting allow increasing the efficiency of training of sportsmen in sprinting.

  15. A risk-based restaurant inspection system in Los Angeles County.

    Science.gov (United States)

    Buchholz, U; Run, G; Kool, J L; Fielding, J; Mascola, L

    2002-02-01

    thermometers, and the presence of any food protection violation. In multivariate analysis, the size of restaurant, the incorrect storage of food, the reuse of food, and the presence of any food protection violation remained significant predictors for becoming a case restaurant. Our data suggest that routine restaurant inspections should concentrate on those establishments that have a large seating capacity or a poor inspection history. Evaluation of inspection data bases in individual local health departments and translation of those findings into inspection guidelines could lead to an increased efficiency and perhaps cost-effectiveness of local inspection programs.

  16. Intelligent Automated Nuclear Fuel Pellet Inspection System

    International Nuclear Information System (INIS)

    Keyvan, S.

    1999-01-01

    At the present time, nuclear pellet inspection is performed manually using naked eyes for judgment and decisionmaking on accepting or rejecting pellets. This current practice of pellet inspection is tedious and subject to inconsistencies and error. Furthermore, unnecessary re-fabrication of pellets is costly and the presence of low quality pellets in a fuel assembly is unacceptable. To improve the quality control in nuclear fuel fabrication plants, an automated pellet inspection system based on advanced techniques is needed. Such a system addresses the following concerns of the current manual inspection method: (1) the reliability of inspection due to typical human errors, (2) radiation exposure to the workers, and (3) speed of inspection and its economical impact. The goal of this research is to develop an automated nuclear fuel pellet inspection system which is based on pellet video (photographic) images and uses artificial intelligence techniques

  17. Inspection of training activities by the NRC's Office of Inspection and Enforcement

    International Nuclear Information System (INIS)

    Ruhlman, W.A.

    1975-01-01

    New requirements in the Code of Federal Regulations, the issuance of new Regulatory Guides and ANSI Standards, have indicated the increased emphasis being placed on training by forces in the Nuclear Industry and the Nuclear Regulatory Commission. A brief description is presented of the functions of the Office of Inspection and Enforcement in the training areas. Three areas are examined: general inspection techniques; training inspection scope; and training inspection bases

  18. Additive Manufacturing Infrared Inspection

    Science.gov (United States)

    Gaddy, Darrell; Nettles, Mindy

    2015-01-01

    The Additive Manufacturing Infrared Inspection Task started the development of a real-time dimensional inspection technique and digital quality record for the additive manufacturing process using infrared camera imaging and processing techniques. This project will benefit additive manufacturing by providing real-time inspection of internal geometry that is not currently possible and reduce the time and cost of additive manufactured parts with automated real-time dimensional inspections which deletes post-production inspections.

  19. Robotized system for in-pipe inspection using pressure tolerant electronics technique

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Ramon R; Hsu, Liu; Peixoto, Alessandro J; Gomes, Luiz P.C.S. [Coordenacao dos Programas de Pos-graduacao de Engenharia (UFRJ/COPPE), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Eletrica. Grupo de Simulacao e Controle em Automacao e Robotica (GSCAR)]. E-mail: ramon, liu, jacoud, lpgomes@coep.ufrj.br; Reis, Ney R.S. dos [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil). Centro de Pesquisas. Lab. de Robotica]. E-mail: salvireis@cenpes.petrobras.com.br

    2003-07-01

    This paper reports the development and experimental evaluation of a robotized system devised to perform two kinds of measurements inside a pipeline: the thickness of the internal wall painting layer and the internal radius. The thickness measurement allows the inspection of the painting layer quality and by measuring several radii it is possible to estimate the pipeline transversal section shape. The proposed scheme is shown to yield very satisfactory results on an actual 14'' (inches) pipeline in a real site. (author)

  20. 76 FR 65165 - Importation of Plants for Planting; Risk-Based Sampling and Inspection Approach and Propagative...

    Science.gov (United States)

    2011-10-20

    ..., this 14th day of October 2011. Kevin Shea, Acting Administrator, Animal and Plant Health Inspection... DEPARTMENT OF AGRICULTURE Animal and Plant Health Inspection Service [Docket No. APHIS-2011-0092] Importation of Plants for Planting; Risk-Based Sampling and Inspection Approach and Propagative Monitoring and...

  1. Optical coherence tomography as an accurate inspection and quality evaluation technique in paper industry

    Science.gov (United States)

    Prykäri, Tuukka; Czajkowski, Jakub; Alarousu, Erkki; Myllylä, Risto

    2010-05-01

    Optical coherence tomography (OCT), a technique for the noninvasive imaging of turbid media, based on low-coherence interferometry, was originally developed for the imaging of biological tissues. Since the development of the technique, most of its applications have been related to the area of biomedicine. However, from early stages, the vertical resolution of the technique has already been improved to a submicron scale. This enables new possibilities and applications. This article presents the possible applications of OCT in paper industry, where submicron or at least a resolution close to one micron is required. This requirement comes from the layered structure of paper products, where layer thickness may vary from single microns to tens of micrometers. This is especially similar to the case with high-quality paper products, where several different coating layers are used to obtain a smooth surface structure and a high gloss. In this study, we demonstrate that optical coherence tomography can be used to measure and evaluate the quality of the coating layer of a premium glossy photopaper. In addition, we show that for some paper products, it is possible to measure across the entire thickness range of a paper sheet. Furthermore, we suggest that in addition to topography and tomography images of objects, it is possible to obtain information similar to gloss by tracking the magnitude of individual interference signals in optical coherence tomography.

  2. Remote inspection with multi-copters, radiological sensors and SLAM techniques

    Science.gov (United States)

    Carvalho, Henrique; Vale, Alberto; Marques, Rúben; Ventura, Rodrigo; Brouwer, Yoeri; Gonçalves, Bruno

    2018-01-01

    Activated material can be found in different scenarios, such as in nuclear reactor facilities or medical facilities (e.g. in positron emission tomography commonly known as PET scanning). In addition, there are unexpected scenarios resulting from possible accidents, or where dangerous material is hidden for terrorism attacks using nuclear weapons. Thus, a technological solution is important to cope with fast and reliable remote inspection. The multi-copter is a common type of Unmanned Aerial Vehicle (UAV) that provides the ability to perform a first radiological inspection in the described scenarios. The paper proposes a solution with a multi-copter equipped with on-board sensors to perform a 3D reconstruction and a radiological mapping of the scenario. A depth camera and a Geiger-Müler counter are the used sensors. The inspection is performed in two steps: i) a 3D reconstruction of the environment and ii) radiation activity inference to localise and quantify sources of radiation. Experimental results were achieved with real 3D data and simulated radiation activity. Experimental tests with real sources of radiation are planned in the next iteration of the work.

  3. Recent developments of non-destructive inspection techniques in Takasago R/D center

    International Nuclear Information System (INIS)

    Kurokawa, Masaaki; Enami, Koji; Asada, Yoshiro

    2000-01-01

    Eddy current testing (ECT) has been widely used in in-service-inspection of generator tubes in nuclear power plants. A bobbin coil probe is mainly and routinely used for fully length inspection of all SG tubes in Japan. From the view point of delectability, a mechanically rotating pancake probe is superior among various ECT probes. Therefore, it is highly desirable to develop a new ECT probe which has similar performance to them rotating pancake probe and has similar capability in actual inspection speed to the bobbin coil probe. In this paper, we will explain the new ECT probe. Main results are as follows. (1) It was shown that the new probe with 4 detecting coils and one slant exciting coil was superior in flaw delectability compared with various kinds of conventional probes. (2) It was shown that electric circuits of amplifiers, multiplexer and so on in the probe itself was very useful to reduce the number of signal cables from detecting coils and to increase signal to noise ratio. (3) we designed and made the ECT probe with thin film coils for detecting coils and with miniaturized electric circuits. In experiments, the prototype probe could detect successfully both axial and circumferential EDM notch of 20% tube thickness. It is confirmed that thin film coils have potential to be used for the new ECT probes and basic functions of electric circuits work very well. (Authors)

  4. Remote inspection with multi-copters, radiological sensors and SLAM techniques

    Directory of Open Access Journals (Sweden)

    Carvalho Henrique

    2018-01-01

    Full Text Available Activated material can be found in different scenarios, such as in nuclear reactor facilities or medical facilities (e.g. in positron emission tomography commonly known as PET scanning. In addition, there are unexpected scenarios resulting from possible accidents, or where dangerous material is hidden for terrorism attacks using nuclear weapons. Thus, a technological solution is important to cope with fast and reliable remote inspection. The multi-copter is a common type of Unmanned Aerial Vehicle (UAV that provides the ability to perform a first radiological inspection in the described scenarios. The paper proposes a solution with a multi-copter equipped with on-board sensors to perform a 3D reconstruction and a radiological mapping of the scenario. A depth camera and a Geiger-Müler counter are the used sensors. The inspection is performed in two steps: i a 3D reconstruction of the environment and ii radiation activity inference to localise and quantify sources of radiation. Experimental results were achieved with real 3D data and simulated radiation activity. Experimental tests with real sources of radiation are planned in the next iteration of the work.

  5. A Steel Ball Surface Quality Inspection Method Based on a Circumferential Eddy Current Array Sensor.

    Science.gov (United States)

    Zhang, Huayu; Xie, Fengqin; Cao, Maoyong; Zhong, Mingming

    2017-07-01

    To efficiently inspect surface defects on steel ball bearings, a new method based on a circumferential eddy current array (CECA) sensor was proposed here. The best probe configuration, in terms of the coil quality factor (Q-factor), magnetic field intensity, and induced eddy current density on the surface of a sample steel ball, was determined using 3-, 4-, 5-, and 6-coil probes, for analysis and comparison. The optimal lift-off from the measured steel ball, the number of probe coils, and the frequency of excitation current suitable for steel ball inspection were obtained. Using the resulting CECA sensor to inspect 46,126 steel balls showed a miss rate of ~0.02%. The sensor was inspected for surface defects as small as 0.05 mm in width and 0.1 mm in depth.

  6. A real-time surface inspection system for precision steel balls based on machine vision

    Science.gov (United States)

    Chen, Yi-Ji; Tsai, Jhy-Cherng; Hsu, Ya-Chen

    2016-07-01

    Precision steel balls are one of the most fundament components for motion and power transmission parts and they are widely used in industrial machinery and the automotive industry. As precision balls are crucial for the quality of these products, there is an urgent need to develop a fast and robust system for inspecting defects of precision steel balls. In this paper, a real-time system for inspecting surface defects of precision steel balls is developed based on machine vision. The developed system integrates a dual-lighting system, an unfolding mechanism and inspection algorithms for real-time signal processing and defect detection. The developed system is tested under feeding speeds of 4 pcs s-1 with a detection rate of 99.94% and an error rate of 0.10%. The minimum detectable surface flaw area is 0.01 mm2, which meets the requirement for inspecting ISO grade 100 precision steel balls.

  7. A Steel Ball Surface Quality Inspection Method Based on a Circumferential Eddy Current Array Sensor

    Directory of Open Access Journals (Sweden)

    Huayu Zhang

    2017-07-01

    Full Text Available To efficiently inspect surface defects on steel ball bearings, a new method based on a circumferential eddy current array (CECA sensor was proposed here. The best probe configuration, in terms of the coil quality factor (Q-factor, magnetic field intensity, and induced eddy current density on the surface of a sample steel ball, was determined using 3-, 4-, 5-, and 6-coil probes, for analysis and comparison. The optimal lift-off from the measured steel ball, the number of probe coils, and the frequency of excitation current suitable for steel ball inspection were obtained. Using the resulting CECA sensor to inspect 46,126 steel balls showed a miss rate of ~0.02%. The sensor was inspected for surface defects as small as 0.05 mm in width and 0.1 mm in depth.

  8. Improved Titanium Billet Inspection Sensitivity through Optimized Phased Array Design, Part I: Design Technique, Modeling and Simulation

    International Nuclear Information System (INIS)

    Lupien, Vincent; Hassan, Waled; Dumas, Philippe

    2006-01-01

    Reductions in the beam diameter and pulse duration of focused ultrasound for titanium inspections are believed to result in a signal-to-noise ratio improvement for embedded defect detection. It has been inferred from this result that detection limits could be extended to smaller defects through a larger diameter, higher frequency transducer resulting in a reduced beamwidth and pulse duration. Using Continuum Probe Designer TM (Pat. Pending), a transducer array was developed for full coverage inspection of 8 inch titanium billets. The main challenge in realizing a large aperture phased array transducer for billet inspection is ensuring that the number of elements remains within the budget allotted by the driving electronics. The optimization technique implemented by Continuum Probe Designer TM yields an array with twice the aperture but the same number of elements as existing phased arrays for the same application. The unequal area element design was successfully manufactured and validated both numerically and experimentally. Part I of this two-part series presents the design, simulation and modeling steps, while Part II presents the experimental validation and comparative study to multizone

  9. Non-destructive inservice inspections

    International Nuclear Information System (INIS)

    Kauppinen, P.; Sarkimo, M.; Lahdenperae, K.

    1998-01-01

    In order to assess the possible damages occurring in the components and structures of operating nuclear power plants during service the main components and structures are periodically inspected by non-destructive testing techniques. The reliability of non-destructive testing techniques applied in these inservice inspections is of major importance because the decisions concerning the needs for repair of components are mainly based on the results of inspections. One of the targets of this research program has been to improve the reliability of non-destructive testing. This has been addressed in the sub-projects which are briefly summarised here. (author)

  10. Intercomparison of techniques for inspection and diagnostics of heavy water reactor pressure tubes: Flaw detection and characterization [Phase 1

    International Nuclear Information System (INIS)

    2006-05-01

    Nuclear power plants with heavy water reactors (HWRs) comprise nine percent of today's operating nuclear units, and more are under construction. Efficient and accurate inspection and diagnostic techniques for various reactor components and systems are an important factor in assuring reliable and safe plant operation. To foster international collaboration in the efficient and safe use of nuclear power, the IAEA conducted a Coordinated Research Programme (CRP) on Inter-comparison of Techniques for HWR Pressure Tube Inspection and Diagnostics. This CRP was carried out within the frame of the IAEA Department of Nuclear Energy's Technical Working Group on Advanced Technologies for HWRs (the TWG-HWR). The TWG-HWR is a group of experts nominated by their governments and designated by the IAEA to provide advice and to support implementation of the IAEA's project on advanced technologies for HWRs. The objective of the CRP was to inter-compare non-destructive inspection and diagnostic techniques, in use and being developed, for structural integrity assessment of HWR pressure tubes. During the first phase of this CRP, participants have investigated the capability of different techniques to detect and characterize flaws. During the second phase of this CRP, participants collaborated to detect and characterize hydride blisters and to determine the hydrogen concentration in Zirconium alloys. The intent was to identify the most effective pressure tube inspection and diagnostic methods, and to identify further development needs. The organizations that have participated in this CRP are: - The Comision Nacional de Energia Atomica (CNEA), Argentina; - Atomic Energy of Canada Ltd. (AECL); Chalk River Laboratories (CRL), Canada; - The Research Institute of Nuclear Power Operations (RINPO), China National Nuclear Corporation (CNNC), China; - Bhabha Atomic Research Centre (BARC), India; - The Korea Electric Power Research Institute (KEPRI), Republic of Korea; - The Korea Atomic Energy

  11. Can non-destructive inspection be reliable

    International Nuclear Information System (INIS)

    Silk, M.G.; Stoneham, A.M.; Temple, J.A.G.

    1988-01-01

    The paper on inspection is based on the book ''The reliability of non-destructive inspection: assessing the assessment of structures under stress'' by the present authors (published by Adam Hilger 1987). Emphasis is placed on the reliability of inspection and whether cracks in welds or flaws in components can be detected. The need for non-destructive testing and the historical attitudes to non-destructive testing are outlined, along with the case of failure. Factors influencing reliable inspection are discussed, and defect detection trials involving round robin tests are described. The development of reliable inspection techniques and the costs of reliability and unreliability are also examined. (U.K.)

  12. Phased Array Ultrasonic Inspection of Titanium Forgings

    International Nuclear Information System (INIS)

    Howard, P.; Klaassen, R.; Kurkcu, N.; Barshinger, J.; Chalek, C.; Nieters, E.; Sun, Zongqi; Fromont, F. de

    2007-01-01

    Aerospace forging inspections typically use multiple, subsurface-focused sound beams in combination with digital C-scan image acquisition and display. Traditionally, forging inspections have been implemented using multiple single element, fixed focused transducers. Recent advances in phased array technology have made it possible to perform an equivalent inspection using a single phased array transducer. General Electric has developed a system to perform titanium forging inspection based on medical phased array technology and advanced image processing techniques. The components of that system and system performance for titanium inspection will be discussed

  13. In-service inspection methods for graphite-epoxy structures on commercial transport aircraft

    Science.gov (United States)

    Phelps, M. L.

    1981-01-01

    In-service inspection methods for graphite-epoxy composite structures on commercial transport aircraft are determined. Graphite/epoxy structures, service incurred defects, current inspection practices and concerns of the airline and manufacturers, and other related information were determind by survey. Based on this information, applicable inspection nondestructive inspection methods are evaluated and inspection techniques determined. Technology is developed primarily in eddy current inspection.

  14. Extreme Learning Machine and Moving Least Square Regression Based Solar Panel Vision Inspection

    Directory of Open Access Journals (Sweden)

    Heng Liu

    2017-01-01

    Full Text Available In recent years, learning based machine intelligence has aroused a lot of attention across science and engineering. Particularly in the field of automatic industry inspection, the machine learning based vision inspection plays a more and more important role in defect identification and feature extraction. Through learning from image samples, many features of industry objects, such as shapes, positions, and orientations angles, can be obtained and then can be well utilized to determine whether there is defect or not. However, the robustness and the quickness are not easily achieved in such inspection way. In this work, for solar panel vision inspection, we present an extreme learning machine (ELM and moving least square regression based approach to identify solder joint defect and detect the panel position. Firstly, histogram peaks distribution (HPD and fractional calculus are applied for image preprocessing. Then an ELM-based defective solder joints identification is discussed in detail. Finally, moving least square regression (MLSR algorithm is introduced for solar panel position determination. Experimental results and comparisons show that the proposed ELM and MLSR based inspection method is efficient not only in detection accuracy but also in processing speed.

  15. Robotized system for in-pipe inspection using pressure tolerant electronics technique

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Ramon R.; Hsu, Liu; Peixoto, Alessandro J.; Gomes, Luiz P.C.S. [Coordenacao dos Programas de Pos-graduacao de Engenharia (UFRJ/COPPE), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Eletrica. Grupo de Simulacao e Controle em Automacao e Robotica (GSCAR)]. E-mail: ramon, liu, jacoud, lpgomes@coep.ufrj.br; Reis, Ney R.S. dos [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil). Centro de Pesquisas. Lab. de Robotica]. E-mail: salvireis@cenpes.petrobras.com.br

    2003-07-01

    This paper reports the development and experimental evaluation of a robotized system devised to perform two kinds of measurements inside a pipeline: the thickness of the internal wall painting layer and the internal radius. The thickness measurement allows the inspection of the painting layer quality and by measuring several radii it is possible to estimate the pipeline transversal section shape. The proposed scheme is shown to yield very satisfactory results on an actual 14'' (inches) pipeline in a real site. (author)

  16. Qualification of the LF-eddy current technique for the inspection of stainless steel cladding and applications on the reactor pressure vessel

    International Nuclear Information System (INIS)

    Weiss, R.; Becker, R.; Lucht, B.; Mohr, F.; Hartwig, K.

    2001-01-01

    As part of the re-inspection of the reactor pressure vessel of the nuclear power plant, the low-frequency-eddy current technique was implemented during the 1995 outage. Since then, this inspection technique and the testing equipment have seen steady further development. Therefore, optimization of the entire testing system, including qualification based on the 1995 results, was conducted. The eddy current testing system was designed as a ten-channel test system with sensors having separate transmitter and receiver coils. The first qualification of the testing technique and sensors was performed using a single-channel system; a second qualification was then carried out using the new testing electronics. The sensor design allows for a simultaneous detection of surface and subsurface flaws. This assumes that testing is performed simultaneously using four frequencies. Data analysis and evaluation are performed using a digital multi-frequency regression analysis technique The detection limits determined using this technique led to the definition of the following recording limits for testing in which the required signal-to-noise ratio of 6 dB was reliably observed. - Detection of surface connected longitudinal and transverse flaws: - notch, 3 mm deep and 10 mm long, for weave bead cladding; - notch, 2 mm deep and 20 mm long, for strip weld cladding. - Detection of embedded planar longitudinal and transverse flaws: - ligament of 7 mm for 8 mm clad thickness and 3 mm; - ligament for 4 mm clad thickness, notch starting at the carbon steel base material with a length of 20 mm. - Detection of embedded volumetric longitudinal and transverse flaws: - 3 mm diameter side-drilled hole (SDH) for 8 mm clad thickness; ligament, 4 mm. For 4 mm clad thickness: diameter, 2 mm SDH; ligament, 2 mm. All SDHs are 55 mm deep

  17. POTENTIAL OF UAV-BASED LASER SCANNER AND MULTISPECTRAL CAMERA DATA IN BUILDING INSPECTION

    Directory of Open Access Journals (Sweden)

    D. Mader

    2016-06-01

    Full Text Available Conventional building inspection of bridges, dams or large constructions in general is rather time consuming and often cost expensive due to traffic closures and the need of special heavy vehicles such as under-bridge inspection units or other large lifting platforms. In consideration that, an unmanned aerial vehicle (UAV will be more reliable and efficient as well as less expensive and simpler to operate. The utilisation of UAVs as an assisting tool in building inspections is obviously. Furthermore, light-weight special sensors such as infrared and thermal cameras as well as laser scanner are available and predestined for usage on unmanned aircraft systems. Such a flexible low-cost system is realized in the ADFEX project with the goal of time-efficient object exploration, monitoring and damage detection. For this purpose, a fleet of UAVs, equipped with several sensors for navigation, obstacle avoidance and 3D object-data acquisition, has been developed and constructed. This contribution deals with the potential of UAV-based data in building inspection. Therefore, an overview of the ADFEX project, sensor specifications and requirements of building inspections in general are given. On the basis of results achieved in practical studies, the applicability and potential of the UAV system in building inspection will be presented and discussed.

  18. Reliability-Based Design and Planning of Inspection and Monitoring of Offshore Wind Turbines

    DEFF Research Database (Denmark)

    Marquez-Dominguez, Sergio

    Maintaining and developing a sustainable wind industry is the main motivation of this PhD thesis entitled “Reliability-based design and planning of inspection and monitoring of offshore wind turbines”. In this thesis, statistical methods and probability theory are important mathematical tools used...... and offshore wind turbine foundations with the aim of improving the design, decreasing structural costs and increasing benefits. Recently, wind energy technology has started to adopt risk and reliability based inspection planning (RBI) as a methodology based on Bayesian decision theories together...

  19. Monitoring and inspection techniques for long term storage of higher activity waste packages

    International Nuclear Information System (INIS)

    Bolton, Gary

    2013-01-01

    In 2009, following recent changes in United Kingdom (UK) Government Policy, the Nuclear Decommissioning Authority (NDA) identified a knowledge gap in the area of long term interim storage of waste packages. A cross-industry Integrated Project Team (IPT) for Interim Storage was created with responsibility for delivering Industry Guidance on the storage of packaged Higher Activity Waste (HAW) for the current UK civil decommissioning and clean-up programmes. This included a remit to direct research and development projects via the NDA's Direct Research Portfolio (DRP) to fill the knowledge gap. The IPT for Interim Storage published Industry Guidance in 2012 which established a method to define generic package performance criteria and made recommendations on monitoring and inspection. The package performance method consists of the following steps; identification of the package safety function, identification of evolutionary processes that may affect safety function performance, determination of measurable indicators of these evolutionary processes and calibration of the indicators into package performance zones. This article provides an overview of three projects funded by the NDA's DRP that the UK National Nuclear Laboratory (NNL) have completed to address monitoring and inspection needs of waste packages in interim storage. (orig.)

  20. Development of nuclear fuel rod inspection technique using ultrasonic resonance phenomenon

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Myung Sun; Lee, Jong Po; Ju, Young Sang [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1995-11-01

    Acoustic resonance scattering from a nuclear fuel rod in water is analyzed. A new model for the background which is attributed to the interference of reflected wave and diffracted wave is found and here named {sup t}he inherent background{sup .} The resonance spectrum of a fuel rod is obtained by subtracting the inherent background from the scattered pressure. And also analyzed are the effect of material damping of cladding tube and pellet on the resonance spectrum of a fuel rod. The propagation characteristics of circumferential waves which cause the resonances of cladding tube is produced and the appropriate resonance modes for the application to the inspection of assembled fuel rods are selected. The resonance modes are experimentally measured for pre- and post-irradiated fuel rods and the validation of the fuel rod inspection using ultrasonic resonance phenomenon is examined. And thin ultrasonic sensors accessible into the narrow interval (about 2-3mm) between assembled fuel rods are designed and manufactured. 14 refs. (Author).

  1. GASVOL 18'' gas pipeline - risk based inspection study

    Energy Technology Data Exchange (ETDEWEB)

    Bjoernoey, Ola H.; Etterdal, Birger A. [Det Norske Veritas (DNV), Oslo (Norway); Guarize, Rosimar; Oliveira, Luiz F.S. [Det Norske Veritas (DNV) (Brazil); Faertes, Denise; Dias, Ricardo [TRANSPETRO - PETROBRAS Transporte S.A., Rio de Janeiro, RJ (Brazil)

    2003-07-01

    This paper describes a risk based approach and inspection planning as part of the Pipeline Integrity Management (PIM) system for the 95.5 km long 18'' GASVOL gas pipeline in the South eastern region of Brazil transporting circa 5 000 000 m3 dry gas per day. Pipeline systems can be subject to several degradation mechanisms and inspection and monitoring are used to ensure system integrity. Modern pipeline regulations and codes are normally based on a core safety or risk philosophy. The detailed design requirements presented in design codes are practical interpretations established so as to fulfill these core objectives. A given pipeline, designed, constructed and installed according to a pipeline code is therefore the realization of a structure, which, along its whole length, meets the applicable safety objectives of that code. The main objective of Pipeline Integrity Management (PIM) is to control and document the integrity of the pipeline for its whole service life, and to do this in a cost-effective manner. DNV has a specific approach to RBI planning, starting with an initial qualitative assessment where pipelines and damage type are ranked according to risk and potential risk reduction by an inspection and then carried forward to a quantitative detailed assessment where the level of complexity and accuracy can vary based on availability of information and owner needs. Detailed assessment requires significant effort in data gathering. The findings are dependent upon the accuracy of the inspection data, and on DNV's interpretation of the pipeline reference system and simplifications in the inspection data reported. The following specific failure mechanisms were investigated: internal corrosion, external corrosion, third party interference, landslides and black powder. RBI planning, in general words, is a 'living process'. In order to optimize future inspections, it is essential that the analyses utilize the most recent information regarding

  2. Field experience with advanced inservice inspection NDE-techniques for detection and sizing

    International Nuclear Information System (INIS)

    Engl, G.; Kronig, M.

    1988-01-01

    This document deals with Non-Destructive Examination (NDE) techniques used for the detection and sizing of cracks. Several techniques, such as L-SAFT, ALOK and Phased Array with UT-Tomography are discussed and compared. (TEC)

  3. Field experience with advanced inservice inspection NDE-techniques for detection and sizing

    Energy Technology Data Exchange (ETDEWEB)

    Engl, G; Kronig, M

    1988-12-31

    This document deals with Non-Destructive Examination (NDE) techniques used for the detection and sizing of cracks. Several techniques, such as L-SAFT, ALOK and Phased Array with UT-Tomography are discussed and compared. (TEC).

  4. QUALITY INSPECTION AND ANALYSIS OF THREE-DIMENSIONAL GEOGRAPHIC INFORMATION MODEL BASED ON OBLIQUE PHOTOGRAMMETRY

    Directory of Open Access Journals (Sweden)

    S. Dong

    2018-04-01

    Full Text Available In order to promote the construction of digital geo-spatial framework in China and accelerate the construction of informatization mapping system, three-dimensional geographic information model emerged. The three-dimensional geographic information model based on oblique photogrammetry technology has higher accuracy, shorter period and lower cost than traditional methods, and can more directly reflect the elevation, position and appearance of the features. At this stage, the technology of producing three-dimensional geographic information models based on oblique photogrammetry technology is rapidly developing. The market demand and model results have been emerged in a large amount, and the related quality inspection needs are also getting larger and larger. Through the study of relevant literature, it is found that there are a lot of researches on the basic principles and technical characteristics of this technology, and relatively few studies on quality inspection and analysis. On the basis of summarizing the basic principle and technical characteristics of oblique photogrammetry technology, this paper introduces the inspection contents and inspection methods of three-dimensional geographic information model based on oblique photogrammetry technology. Combined with the actual inspection work, this paper summarizes the quality problems of three-dimensional geographic information model based on oblique photogrammetry technology, analyzes the causes of the problems and puts forward the quality control measures. It provides technical guidance for the quality inspection of three-dimensional geographic information model data products based on oblique photogrammetry technology in China and provides technical support for the vigorous development of three-dimensional geographic information model based on oblique photogrammetry technology.

  5. Quality Inspection and Analysis of Three-Dimensional Geographic Information Model Based on Oblique Photogrammetry

    Science.gov (United States)

    Dong, S.; Yan, Q.; Xu, Y.; Bai, J.

    2018-04-01

    In order to promote the construction of digital geo-spatial framework in China and accelerate the construction of informatization mapping system, three-dimensional geographic information model emerged. The three-dimensional geographic information model based on oblique photogrammetry technology has higher accuracy, shorter period and lower cost than traditional methods, and can more directly reflect the elevation, position and appearance of the features. At this stage, the technology of producing three-dimensional geographic information models based on oblique photogrammetry technology is rapidly developing. The market demand and model results have been emerged in a large amount, and the related quality inspection needs are also getting larger and larger. Through the study of relevant literature, it is found that there are a lot of researches on the basic principles and technical characteristics of this technology, and relatively few studies on quality inspection and analysis. On the basis of summarizing the basic principle and technical characteristics of oblique photogrammetry technology, this paper introduces the inspection contents and inspection methods of three-dimensional geographic information model based on oblique photogrammetry technology. Combined with the actual inspection work, this paper summarizes the quality problems of three-dimensional geographic information model based on oblique photogrammetry technology, analyzes the causes of the problems and puts forward the quality control measures. It provides technical guidance for the quality inspection of three-dimensional geographic information model data products based on oblique photogrammetry technology in China and provides technical support for the vigorous development of three-dimensional geographic information model based on oblique photogrammetry technology.

  6. Risk-Based Inspection and Maintenance Planning Optimization of Offshore Wind Turbines

    DEFF Research Database (Denmark)

    Ramírez, José G. Rangel; Sørensen, John Dalsgaard

    2009-01-01

    A risk-based inspection planning (RBI) approach applied to offshore wind turbines (OWT) is presented, based on RBI methodology developed in the last decades in the oil and gas industry. In wind farm (IWF) and single-alone locations are considered using a code-established turbulence models including...

  7. Reliability of non-destructive test techniques in the inspection of pipelines used in the oil industry

    International Nuclear Information System (INIS)

    Carvalho, A.A.; Rebello, J.M.A.; Souza, M.P.V.; Sagrilo, L.V.S.; Soares, S.D.

    2008-01-01

    The aim of this work is to evaluate the reliability of non-destructive test (NDT) techniques for the inspection of pipeline welds employed in the petroleum industry. Radiography, manual and automatic ultrasonic techniques using pulse-echo and time of flight diffraction (TOFD) were employed. Three classes of defects were analyzed: lack of penetration (LP), lack of fusion (LF) and undercut (UC). The tests were carried out on specimen made from pipelines containing defects, which had been artificially inserted on laying the weld bead. The results showed the superiority of the automatic ultrasonic tests for defect detection compared with the manual ultrasonic and radiographic tests. Additionally, artificial neural networks (ANN) were used in the detection and automatic classification of the defects

  8. Risk-based prioritization and its application to inspection of valves in the water sector

    International Nuclear Information System (INIS)

    Marlow, David R.; Beale, David J.; Mashford, John S.

    2012-01-01

    Isolation valves facilitate the effective operation and maintenance of water supply networks, but their sheer number presents a significant asset management challenge. If left unmanaged, valve reliability issues can become widespread. Inspections provide a means of increasing reliability, but a survey of industry practices indicated that some utilities did not have such a program in place. To improve asset management and reduce business risk exposure, such utilities need an effective means of commencing inspection programs. From a theoretical perspective, risk concepts provide a means of optimizing maintenance effort. However, in the face of poor data on reliability or condition, pragmatic approaches to risk-based prioritization are needed. One such approach, risk indexing, is considered in this paper. Background on the research is presented, including the application of risk-based inspection concepts within the water sector. The development of a risk indexing scheme is then investigated, drawing on two industry workshops in which the analytical hierarchy process was used to set relative weights. It is concluded that risk indexing provides the basis for a rational prioritization process in the absence of data on valve reliability or condition. - Highlights: ► Importance of valve inspections to water network reliability. ► Theoretical perspective of risk concepts that provide a means of optimizing inspection programs. ► Pragmatic approaches to prioritization in light of poor valve data. ► Development and assessment of a risk index scheme. ► Use of the analytical hierarchy process to set relative weights of risk factors.

  9. Reliability Assessment and Reliability-Based Inspection and Maintenance of Offshore Wind Turbines

    DEFF Research Database (Denmark)

    Ramirez, José Rangel

    actions are the most relevant and effective means of control of deterioration. The risk-based inspection planning methodology, based on Bayesian decision theory, represents an important tool to identify the suitable strategy to inspect and control the deterioration in structures such as offshore wind...... performance during the life cycle. The deterioration processes, such as fatigue and corrosion, are typically affecting offshore structural systems. This damage decreases the system performance and increases the risk of failure, thus not fulfilling the established safety criteria. Inspection and maintenance...... to their offshore location, no pollution risks and low human risks since they are unmanned. This allows the allocation of lower reliability level compared to e.g. oil & gas installations. With the incursion to water depths between 20 and 50 meters, the use of jacket and tripod structures represents a feasible...

  10. Risk-based Inspection Guide for the Susquehanna Station HPCI system

    International Nuclear Information System (INIS)

    Travis, R.; Higgins, J.; Gunther, W.; Shier, W.

    1992-11-01

    The High Pressure Coolant Injection (HPCI) system has been examined from a risk perspective. A system Risk-based Inspection Guide (S-RIG) has been developed as an aid to HPCI system inspections at the Susquehanna Steam Electric Station (SSES) which is operated by Pennsylvania Power ampersand Light (PP ampersand L). Included in this S-RIG is a discussion of the role of HPCI in mitigating accidents and a presentation of PRA-based failure modes which could prevent proper operation of the system. The S-RIG uses industry operating experience, including plant-specific illustrative examples, to augment the basic PRA failure modes. It is designed to be used as a reference for both routine inspections and the evaluation of the significance of component failures

  11. A delay time model for a mission-based system subject to periodic and random inspection and postponed replacement

    International Nuclear Information System (INIS)

    Yang, Li; Ma, Xiaobing; Zhai, Qingqing; Zhao, Yu

    2016-01-01

    We propose an inspection and replacement policy for a single component system that successively executes missions with random durations. The failure process of the system can be divided into two states, namely, normal and defective, following the delay time concept. Inspections are carried out periodically and immediately after the completion of each mission (random inspections). The failed state is always identified immediately, whereas the defective state can only be revealed by an inspection. If the system fails or is defective at a periodic inspection, then replacement is immediate. If, however, the system is defective at a random inspection, then replacement will be postponed if the time to the subsequent periodic inspection is shorter than a pre-determined threshold, and immediate otherwise. We derive the long run expected cost per unit time and then investigate the optimal periodic inspection interval and postponement threshold. A numerical example is presented to demonstrate the applicability of the proposed maintenance policy. - Highlights: • A delay time model of inspection is introduced for mission-based systems. • Periodic and random inspections are performed to check the state. • Replacement of the defective system at a random inspection can be postponed.

  12. The API methodology for risk-based inspection (RBI) analysis for the petroleum and petrochemical industry

    International Nuclear Information System (INIS)

    Reynolds, J.T.

    1998-01-01

    Twenty-one petroleum and petrochemical companies are currently sponsoring a project within the American Petroleum Institute (API) to develop risk-based inspection (RBI) methodology for application in the refining and petrochemical industry. This paper describes that particular RBI methodology and provides a summary of the three levels of RBI analysis developed by the project. Also included is a review of the first pilot project to validate the methodology by applying RBI to several existing refining units. The failure for pressure equipment in a process unit can have several undesirable effects. For the purpose of RBI analysis, the API RBI program categorizes these effects into four basic risk outcomes: flammable events, toxic releases, major environmental damage, and business interruption losses. API RBI is a strategic process, both qualitative and quantitative, for understanding and reducing these risks associated with operating pressure equipment. This paper will show how API RBI assesses the potential consequences of a failure of the pressure boundary, as well as assessing the likelihood (probability) of failure. Risk-based inspection also prioritizes risk levels in a systematic manner so that the owner-user can then plan an inspection program that focuses more resources on the higher risk equipment; while possibly saving inspection resources that are not doing an effective job of reducing risk. At the same time, if consequence of failure is a significant driving force for high risk equipment items, plant management also has the option of applying consequence mitigation steps to minimize the impact of a hazardous release, should one occur. The target audience for this paper is engineers, inspectors, and managers who want to understand what API Risk-Based Inspection is all about, what are the benefits and limitations of RBI, and how inspection practices can be changed to reduce risks and/or save costs without impacting safety risk. (Author)

  13. Evaluation techniques of accuracy characteristics for non-contact photonic track inspection system

    Science.gov (United States)

    Popov, Dmitry V.; Ryabichenko, Roman B.; Krivosheina, Elena A.

    2005-06-01

    The most important task in Moscow metro is increasing safety of railway traffic. For safety purposes six track parameters are measured in Moscow Metro with help of track measurement car. Equipment mounted on this car works only in contact mode and doesn't provide modem requirements for accuracy. Also important task is measurement at high speeds, but contact technology limits speed of movement up to 25mph on rail switches. Current system can't measure in real-time mode. For decision of these field of tasks non-contact photonic measurement system (KSIR) is constructed. The KSIR works at speeds up to 70 mph and measure seven track parameters. The KSIR contains four subsystems: rail wear, height and track gauge measurement (BFSM); rail slump measurement (FTP); contact rail measurement (FKR); speed, level and car locating (USI). KSIR contains five CCD matrix cameras, four line CCD cameras, five infrared stripe lasers and four spot infrared lasers. Laser forms shape on the rail. CCD-camera acquires rail image and transfers it into the digital signal processor which produces preliminary calculation ofrail shape. Then image is transferred into the central computer to calculate values of rail characteristics. Angles between photonic unit and rail bring distortions in images from cameras. Additional distortions are caused by short-focus optics and small distance between camera and track. This distance is limited by structure clearance. The transformation algorithms for distortions elimination are applied. It's based on surfaces spline-approximation. As a result the KSIR calculates coefficients of approximating polynomials. The calibration is performed for checking accuracy of measurement in BFSM, FTP and FKR units. Evaluation techniques of accuracy characteristics are considered.

  14. In-Operation Inspection Technology development. Development of the degradation prediction technique

    International Nuclear Information System (INIS)

    Nakamuta, Yasushi; Miyoshi, Toshiaki; O'shima, Eiji

    1999-01-01

    As In-Operation Inspection Technology (IOI) , we selected primary loop recirculation (PLR) pump, sea water pump, small diameter pipe branch in the steam generator (SG) room and motor driven valve for the typical component of the nuclear power plant, and we are developing the technology which can forecast the residual life of parts in the plan until FY2000. With respect to PLR pump and sea water pump, technical procedure for predicting the propagation of bearing wear, under the combined effect of several degradation conditions of each pump during the plant operation are under development. With respect to pipe branch, we are developing the non-contact laser sensors, and we are constructing the system which forecasts high cycle fatigue in the root of pipe branch by monitoring the vibration of pipe branch. With respect to motor driven valve, technical procedure for predicting the thermal degradation of gaskets and gland packing, technical procedure for predicting the stem nut wear and wear of hunging portion of valve disc, and technical procedure for detecting the degradation of driving parts, without disassembling the motor driven valve, are under development. (author)

  15. Development of high-sensitivity ultrasonic techniques for in-service inspection of nuclear reactors

    International Nuclear Information System (INIS)

    Linzer, M.

    1977-01-01

    The principal objective of the program is to develop techniques to enhance the sensitivity of ultrasonic signals which are below the random noise of the system. A secondary objective is to develop instrumentation for improved discrimination of flaw signals from background ''clutter'' and for characterization of failure-related material properties through measurements of ultrasonic parameters such as velocity and attenuation. The improved techniques will be applied to detect flaws in nuclear reactor materials and components

  16. Toward a drone-based EL and PL inspection tool for PV power plants

    DEFF Research Database (Denmark)

    Riedel, Nicholas; Benatto, Gisele Alves dos Reis; Thorsteinsson, Sune

    2017-01-01

    of image detail and qualitative insight compared to IR thermography. Furthermore, detection and identification of incipient or severe faults in PV panels is more straightforward.This project proposes for the first time a fast and accurate automatic drone-based inspection method for large PV plants...

  17. Reliability-based design and planning of inspection and monitoring of offshore wind turbines

    DEFF Research Database (Denmark)

    Dominguez, Sergio Marquez

    When the wind is blowing fiercely, wind turbines must resist. Wind turbines have to withstand the rough environmental conditions in the most reliable manner and start to produce renewable energy when the wind becomes friendly again. Never give up ‘wind turbine’ face the winds and be proud of cont...... of probability and statistics for application in structural reliability-based risk inspections....

  18. Auxiliary Sensor-Based Borehole Transient Electromagnetic System for the Nondestructive Inspection of Multipipe Strings

    Directory of Open Access Journals (Sweden)

    Bo Dang

    2017-08-01

    Full Text Available Transient electromagnetic (TEM techniques are widely used in the field of geophysical prospecting. In borehole detection, the nondestructive inspection (NDI of a metal pipe can be performed efficiently using the properties of eddy currents. However, with increasing concern for safety in oil and gas production, more than one string of pipe is used to protect wellbores, which complicates data interpretation. In this paper, an auxiliary sensor-based borehole TEM system for the NDI of multipipe strings is presented. On the basis of the characteristics of the borehole TEM model, we investigate the principle behind the NDI of multipipe strings using multiple time slices of induced electromotive force (EMF in a single sensor. The results show that the detection performance of NDI is strongly influenced by eddy-current diffusion in the longitudinal direction. To solve this problem, we used time slices of the induced EMF in both the main and auxiliary sensors. The performance of the proposed system was verified by applying it to an oil well with a production casing and liner. Moreover, field experiments were conducted, and the results demonstrate the effectiveness of the proposed method.

  19. Meat and Fish Freshness Inspection System Based on Odor Sensing

    OpenAIRE

    Hasan, Najam ul; Ejaz, Naveed; Ejaz, Waleed; Kim, Hyung Seok

    2012-01-01

    We propose a method for building a simple electronic nose based on commercially available sensors used to sniff in the market and identify spoiled/contaminated meat stocked for sale in butcher shops. Using a metal oxide semiconductor-based electronic nose, we measured the smell signature from two of the most common meat foods (beef and fish) stored at room temperature. Food samples were divided into two groups: fresh beef with decayed fish and fresh fish with decayed beef. The prime objective...

  20. Establishment of mobile based nuclear safety inspection system

    International Nuclear Information System (INIS)

    Kim, In Hyeon; Lee, Yoon; Choi, Keun Ho; Lee, Kwang Pyo; Cha, Gi Hyeon; Gook, Cheol Woong; Park, Tae Joo; Kang, Roc Hyeong; Kim, Ji Young; Yoo, Mi Jung

    2005-03-01

    We have developed the mobile-based atomic energy status real time monitoring system and mobile-based atomic energy accident and trouble retrieval system through this study. The mobile-based atomic energy status real time monitoring system is the system enabling its users to monitor nineteen (19) Nuclear Power Plants under operation in the real time based on the PDA(Personal Digital Assistance) via a wireless communication. We have developed the mobile information providing server program and PDA client program for the purpose of providing the atomic energy status information service on the PDA by linking the real time atomic energy status information collected by the computerized technical advisory system for the radiological emergency installed and operated by the KINS. The mobile based atomic energy accident and trouble retrieval system has been developed under the intention of enabling the site inspector to effectively use the past information upon performing the test works at the sites through the local retrieval of past accidents and troubles occurred in the Nuclear Power Plants at the mobile client(PDA). In this regard, we have developed the client program to retrieve the atomic energy accident and trouble status by installing the accident and trouble information database. We also include the function supporting the rapid site report through the employees' information retrieval, site status image file transmission, e-mail and SMS(Short Message Service)

  1. Meat and fish freshness inspection system based on odor sensing.

    Science.gov (United States)

    Najam ul Hasan; Ejaz, Naveed; Ejaz, Waleed; Kim, Hyung Seok

    2012-11-09

    We propose a method for building a simple electronic nose based on commercially available sensors used to sniff in the market and identify spoiled/contaminated meat stocked for sale in butcher shops. Using a metal oxide semiconductor-based electronic nose, we measured the smell signature from two of the most common meat foods (beef and fish) stored at room temperature. Food samples were divided into two groups: fresh beef with decayed fish and fresh fish with decayed beef. The prime objective was to identify the decayed item using the developed electronic nose. Additionally, we tested the electronic nose using three pattern classification algorithms (artificial neural network, support vector machine and k-nearest neighbor), and compared them based on accuracy, sensitivity, and specificity. The results demonstrate that the k-nearest neighbor algorithm has the highest accuracy.

  2. Meat and Fish Freshness Inspection System Based on Odor Sensing

    Directory of Open Access Journals (Sweden)

    Hyung Seok Kim

    2012-11-01

    Full Text Available We propose a method for building a simple electronic nose based on commercially available sensors used to sniff in the market and identify spoiled/contaminated meat stocked for sale in butcher shops. Using a metal oxide semiconductor-based electronic nose, we measured the smell signature from two of the most common meat foods (beef and fish stored at room temperature. Food samples were divided into two groups: fresh beef with decayed fish and fresh fish with decayed beef. The prime objective was to identify the decayed item using the developed electronic nose. Additionally, we tested the electronic nose using three pattern classification algorithms (artificial neural network, support vector machine and k-nearest neighbor, and compared them based on accuracy, sensitivity, and specificity. The results demonstrate that the k-nearest neighbor algorithm has the highest accuracy.

  3. Application of Synthetic Aperture Focusing Technique for inspection of plate-like structures using EMAT generated Lamb waves

    Directory of Open Access Journals (Sweden)

    Mirchev Yordan

    2018-01-01

    Full Text Available The main challenge for guided wave inspection is exact defect characterization and sizing. EMAT generated Lamb waves usually have low signal-to-noise ratio which reduces the defect detection, characterization and sizing capabilities. That's why in most cases the method is used only as a screening tool. The Synthetic Aperture Focusing Technique is a process that increases the signal-to-noise ratio by numerically focusing the acoustic fields. In this paper the application of SAFT is tested over EMAT generated Lamb waves. The improvement of lateral resolution and signal-to-noise ratio is evaluated. Results are presented as a comparison between standard B-scan and SAFT processed data.

  4. Application of risk-based methods for inspection of nuclear power plant components

    International Nuclear Information System (INIS)

    Balkey, K.R.

    1992-01-01

    In-service inspections (ISIs) can play a significant role in minimizing equipment and structural failures. All aspects of inspections, i.e., objectives, method, timing, and the acceptance criteria for detected flaws can affect the probability of component failure. Where ISI programs exist, they are primarily based on prior experience and engineering judgment. At best, some include an implicit consideration of risk (probability of failure multiplied by consequence). Since late 1988, a multidisciplined American Society of Mechanical Engineers (ASME) Research Task Force on Risk-Based Inspection Guidelines has been addressing the general question of how to formally incorporate risk considerations into plans and requirements for the ISI of components and structural systems. The task force and steering committee that guided the project have concluded that appropriate analytical methods exist for evaluating and quantifying risks associated with pressure boundary and structural failures. With the support of about a dozen industry and government organizations, the research group has recommended a general methodology for establishing a risk-based inspection program that could be applied to any nuclear system or structural system

  5. Development of flexural vibration inspection techniques to rapidly assess the structural health of rural bridge systems

    Science.gov (United States)

    Brian K. Brashaw; Robert Vatalaro; Xiping Wang; Kevin Sarvela; James P. Wacker

    2008-01-01

    Approximately 4,000 vehicle bridges in the State of Minnesota contain structural timber members. Recent research at the University of Minnesota Duluth Natural Resources Research Institute (UMD NRRI) has been conducted on vibration testing of timber bridges as a means of developing rapid in-place testing techniques for assessing the structural health of bridges. The...

  6. Future plans for performance analysis and maintenance/inspection optimization of shutoff rods based on the case study of Bruce Power Unit-3 Shutoff Rod 5 inspection

    International Nuclear Information System (INIS)

    Nasimi, E.; Gabbar, H.A.

    2011-01-01

    Shutdown System 1 (SDS1) is a preferred method for a quick shutdown of nuclear fission process in CANDU (CANada Deuterium Uranium) reactor units. Failure of a routine SDS1 safety test during Fall 2009 outage resulted in the need to develop and execute a new methodology for Shutoff Rod inspection and re-evaluate the known degradation mechanisms and failure modes. This paper describes the development of this methodology and the obtained results. It also proposes several alternative solutions for the future performance analysis and maintenance/inspection optimization for SDS1 Shutoff Rods based on the Bruce Power Unit-3 Shutoff Rod 5 case study. (author)

  7. Bayesian inferences of generation and growth of corrosion defects on energy pipelines based on imperfect inspection data

    International Nuclear Information System (INIS)

    Qin, H.; Zhou, W.; Zhang, S.

    2015-01-01

    Stochastic process-based models are developed to characterize the generation and growth of metal-loss corrosion defects on oil and gas steel pipelines. The generation of corrosion defects over time is characterized by the non-homogenous Poisson process, and the growth of depths of individual defects is modeled by the non-homogenous gamma process (NHGP). The defect generation and growth models are formulated in a hierarchical Bayesian framework, whereby the parameters of the models are evaluated from the in-line inspection (ILI) data through the Bayesian updating by accounting for the probability of detection (POD) and measurement errors associated with the ILI data. The Markov Chain Monte Carlo (MCMC) simulation in conjunction with the data augmentation (DA) technique is employed to carry out the Bayesian updating. Numerical examples that involve simulated ILI data are used to illustrate and validate the proposed methodology. - Highlights: • Bayesian updating of growth and generation models of defects on energy pipelines. • Non-homogeneous Poisson process for defect generation. • Non-homogeneous gamma process for defect growth. • Updating based on inspection data with detecting and sizing uncertainties. • MCMC in conjunction with data augmentation technique employed for the updating.

  8. Risk-based Inspection Planning Optimisation of Offshore Wind Turbines

    DEFF Research Database (Denmark)

    Ramirez, José Rangel; Sørensen, John Dalsgaard

    2011-01-01

    Wind industry is substantially propelled and the future scenarios designate offshore locations as important sites for energy production. With this development, offshore wind farms represent a feasible option to accomplish the needed energy, bringing with it technical and economical challenges......, but considering the lower reliability level for wind turbines. This framework is addressing fatigue prone details in welded steel joints typically located in the wind turbine substructure. The increase of turbulence in-wind farms (IWF) due to wake effects is taken into account using a code-based turbulence model...

  9. A real-time standard parts inspection based on deep learning

    Science.gov (United States)

    Xu, Kuan; Li, XuDong; Jiang, Hongzhi; Zhao, Huijie

    2017-10-01

    Since standard parts are necessary components in mechanical structure like bogie and connector. These mechanical structures will be shattered or loosen if standard parts are lost. So real-time standard parts inspection systems are essential to guarantee their safety. Researchers would like to take inspection systems based on deep learning because it works well in image with complex backgrounds which is common in standard parts inspection situation. A typical inspection detection system contains two basic components: feature extractors and object classifiers. For the object classifier, Region Proposal Network (RPN) is one of the most essential architectures in most state-of-art object detection systems. However, in the basic RPN architecture, the proposals of Region of Interest (ROI) have fixed sizes (9 anchors for each pixel), they are effective but they waste much computing resources and time. In standard parts detection situations, standard parts have given size, thus we can manually choose sizes of anchors based on the ground-truths through machine learning. The experiments prove that we could use 2 anchors to achieve almost the same accuracy and recall rate. Basically, our standard parts detection system could reach 15fps on NVIDIA GTX1080 (GPU), while achieving detection accuracy 90.01% mAP.

  10. Mobile robot teleoperation system for plant inspection based on collecting and utilizing environment data

    International Nuclear Information System (INIS)

    Kawabata, Kuniaki; Watanabe, Nobuyasu; Asama, Hajime; Kita, Nobuyuki; Yang, Hai-quan

    2004-01-01

    This paper describes about development of a mobile robot teleoperation system for plant inspection. In our system, the robot is an agent for collecting the environment data and is also teleoperated by the operator utilizing such accumulated environment data which is displayed on the operation interface. The robot equips many sensors for detecting the state of the robot and the environment. Such redundant sensory system can be also utilized to collect the working environment data on-site while the robot is patrolling. Here, proposed system introduces the framework of collecting and utilizing environment data for adaptive plant inspection using the teleoperated robot. A view simulator is primarily aiming to facilitate evaluation of the visual sensors and algorithms and is also extended as the Environment Server, which is the core technology of the digital maintenance field for the plant inspection. In order to construct detailed seamless digital maintenance field mobile robotic technology is utilized to supply environment data to the server. The sensory system on the robot collect the environment data on-site and such collected data is uploaded to the Environment Server for compiling accurate digital environment data base. The robot operator also can utilize accumulated environment data by referring to the Environment Server. In this paper, we explain the concept of our teleoperation system based on collecting and utilizing environment data. Using developed system, inspection patrol experiments were attempted in the plant mock-up. Experimental results are shown by using an omnidirectional mobile robot with sensory system and the Environment Server. (author)

  11. Development of an eddy current inspection technique for sleeved engine disk bolt holes

    International Nuclear Information System (INIS)

    Palanisamy, R.; Lakin, K.M.

    1983-01-01

    Recent research programs have concentrated mainly on developing techniques to characterize surface breaking cracks and very little has been done towards characterizing subsurface flaws in conducting materials. Presented in this paper are the results of some initial theoretical work aimed at the development of a reliable eddy current technique to detect and characterize defects in engine disk bolt holes under a 0.05'' stainless steel sleeve. The change in impedance of an absolute eddy current coil with and without ferrite core, and the distribution of eddy currents around a second layer crack with and without a thin insulating film between the two conducting layers have been predicted numerically. The overall system development goals and methods to accomplish them are outlined briefly

  12. A pilot application of risk-based methods to establish in-service inspection priorities for nuclear components at Surry Unit 1 Nuclear Power Station

    International Nuclear Information System (INIS)

    Vo, T.; Gore, B.; Simonen, F.; Doctor, S.

    1994-08-01

    As part of the Nondestructive Evaluation Reliability Program sponsored by the US Nuclear Regulatory Commission, the Pacific Northwest Laboratory is developing a method that uses risk-based approaches to establish in-service inspection plans for nuclear power plant components. This method uses probabilistic risk assessment (PRA) results and Failure Modes and Effects Analysis (FEMA) techniques to identify and prioritize the most risk-important systems and components for inspection. The Surry Nuclear Power Station Unit 1 was selected for pilot applications of this method. The specific systems addressed in this report are the reactor pressure vessel, the reactor coolant, the low-pressure injection, and the auxiliary feedwater. The results provide a risk-based ranking of components within these systems and relate the target risk to target failure probability values for individual components. These results will be used to guide the development of improved inspection plans for nuclear power plants. To develop inspection plans, the acceptable level of risk from structural failure for important systems and components will be apportioned as a small fraction (i.e., 5%) of the total PRA-estimated risk for core damage. This process will determine target (acceptable) risk and target failure probability values for individual components. Inspection requirements will be set at levels to assure that acceptable failure probabilistics are maintained

  13. ILT based defect simulation of inspection images accurately predicts mask defect printability on wafer

    Science.gov (United States)

    Deep, Prakash; Paninjath, Sankaranarayanan; Pereira, Mark; Buck, Peter

    2016-05-01

    At advanced technology nodes mask complexity has been increased because of large-scale use of resolution enhancement technologies (RET) which includes Optical Proximity Correction (OPC), Inverse Lithography Technology (ILT) and Source Mask Optimization (SMO). The number of defects detected during inspection of such mask increased drastically and differentiation of critical and non-critical defects are more challenging, complex and time consuming. Because of significant defectivity of EUVL masks and non-availability of actinic inspection, it is important and also challenging to predict the criticality of defects for printability on wafer. This is one of the significant barriers for the adoption of EUVL for semiconductor manufacturing. Techniques to decide criticality of defects from images captured using non actinic inspection images is desired till actinic inspection is not available. High resolution inspection of photomask images detects many defects which are used for process and mask qualification. Repairing all defects is not practical and probably not required, however it's imperative to know which defects are severe enough to impact wafer before repair. Additionally, wafer printability check is always desired after repairing a defect. AIMSTM review is the industry standard for this, however doing AIMSTM review for all defects is expensive and very time consuming. Fast, accurate and an economical mechanism is desired which can predict defect printability on wafer accurately and quickly from images captured using high resolution inspection machine. Predicting defect printability from such images is challenging due to the fact that the high resolution images do not correlate with actual mask contours. The challenge is increased due to use of different optical condition during inspection other than actual scanner condition, and defects found in such images do not have correlation with actual impact on wafer. Our automated defect simulation tool predicts

  14. Microprocessor based techniques at CESR

    International Nuclear Information System (INIS)

    Giannini, G.; Cornell Univ., Ithaca, NY

    1981-01-01

    Microprocessor based systems succesfully used in connection with the High Energy Physics experimental program at the Cornell Electron Storage Ring are described. The multiprocessor calibration system for the CUSB calorimeter is analyzed in view of present and future applications. (orig.)

  15. Application of the cylindrically guided wave technique for bolt and pump shaft inspections

    International Nuclear Information System (INIS)

    Light, G.M.; Ruescher, E.H.; Bloom, E.A.; Joshi, N.R.; Tsai, Y.M.; Liu, S.N.

    1993-01-01

    Elastic wave propagation in a bounded medium significantly differs from that in an unbounded medium. The bounded medium in the form of a cylinder acts like a solid waveguide directing the wave with its geometry. A continuous or a pulsed wave interacts with cylindrical boundaries producing mode-converted signals in addition to the backwall echo. The signals are received at constant time intervals directly proportional to the diameter of a solid cylindrical object such as a bolt or an anchor stud. The Cylindrically Guided Wave Technique (CGWT) makes intelligent use of the mode-converted signals, or trailing pulses, to detect corrosion wastages and cracks in cylindrical objects. (orig.)

  16. Probabilistic Fatigue Life Updating for Railway Bridges Based on Local Inspection and Repair.

    Science.gov (United States)

    Lee, Young-Joo; Kim, Robin E; Suh, Wonho; Park, Kiwon

    2017-04-24

    Railway bridges are exposed to repeated train loads, which may cause fatigue failure. As critical links in a transportation network, railway bridges are expected to survive for a target period of time, but sometimes they fail earlier than expected. To guarantee the target bridge life, bridge maintenance activities such as local inspection and repair should be undertaken properly. However, this is a challenging task because there are various sources of uncertainty associated with aging bridges, train loads, environmental conditions, and maintenance work. Therefore, to perform optimal risk-based maintenance of railway bridges, it is essential to estimate the probabilistic fatigue life of a railway bridge and update the life information based on the results of local inspections and repair. Recently, a system reliability approach was proposed to evaluate the fatigue failure risk of structural systems and update the prior risk information in various inspection scenarios. However, this approach can handle only a constant-amplitude load and has limitations in considering a cyclic load with varying amplitude levels, which is the major loading pattern generated by train traffic. In addition, it is not feasible to update the prior risk information after bridges are repaired. In this research, the system reliability approach is further developed so that it can handle a varying-amplitude load and update the system-level risk of fatigue failure for railway bridges after inspection and repair. The proposed method is applied to a numerical example of an in-service railway bridge, and the effects of inspection and repair on the probabilistic fatigue life are discussed.

  17. Advances based on digital technology named TEDDY+ for inspection of eddy current

    International Nuclear Information System (INIS)

    Barcenilla, V.; Hernandez, J.; Ribes, B.

    2007-01-01

    As a result of the recent developing line of eddy current data acquisition system a new product based on digital technology named TEDDY+, comes to the market. With only 4 kg of weight constitutes a great advance with regards to other equipment's available in the market. These advances, have enabled, among others, to increase considerably the signal to noise (S/N) ratio, avoid typical saturation problems in the eddy current signal, increase the inspection speed, eliminate the reference probe, detect the air/tube signal in real time, and the possibility to integrate the tester inside a push puller thanks to its reduced size and to have integrated as part of the ET equipment the mechanical systems control board. Two product lines have been developed, one oriented to any market and application (nuclear market, industrial and aeronautical, chemical and petrochemical, etc) and other specially dedicated to the massive inspection of tubes, named TEDDY+SP (Suitcase Pusher). Both lines are prepared to use eddy current arrays which clearly constitute the future of the eddy current inspection systems. The new TEDDY+ line of products presented in this paper constitutes one of the most powerful and reliable existing in the market. These improvements and novelties place the new ET inspection system from Tecnatom as one of the most powerful and reliable in the market. (Author)

  18. Development of a risk-based in-service inspection program for an LMR

    International Nuclear Information System (INIS)

    King, R.W.; Buschman, H.W.

    1996-01-01

    The emerging application of risk-based assessment technology to the operation and maintenance of nuclear power plants holds considerable promise for improving efficiency and reducing operating costs. Experimental Breeder Reactor II (EBR-II) is a liquid-metal-cooled fast reactor (LMR) that operated for 30 yr before shutting down in September 1994 due to program termination. Prior to the shutdown of EBR-II, an in-service inspection (ISI) program was developed that exploited certain advantages of the LMR design. For example, it demonstrated passive response to plant upset events, low-pressure primary coolant, and compatibility of the coolant and reactor materials. This ISI program was based on work currently being done by an American Society of Mechanical Engineers (ASME) Research Task Force on Risk-Based Inspection

  19. Evaluation of pipeline defect's characteristic axial length via model-based parameter estimation in ultrasonic guided wave-based inspection

    International Nuclear Information System (INIS)

    Wang, Xiaojuan; Tse, Peter W; Dordjevich, Alexandar

    2011-01-01

    The reflection signal from a defect in the process of guided wave-based pipeline inspection usually includes sufficient information to detect and define the defect. In previous research, it has been found that the reflection of guided waves from even a complex defect primarily results from the interference between reflection components generated at the front and the back edges of the defect. The respective contribution of different parameters of a defect to the overall reflection can be affected by the features of the two primary reflection components. The identification of these components embedded in the reflection signal is therefore useful in characterizing the concerned defect. In this research, we propose a method of model-based parameter estimation with the aid of the Hilbert–Huang transform technique for the purpose of decomposition of a reflection signal to enable characterization of the pipeline defect. Once two primary edge reflection components are decomposed and identified, the distance between the reflection positions, which closely relates to the axial length of the defect, could be easily and accurately determined. Considering the irregular profiles of complex pipeline defects at their two edges, which is often the case in real situations, the average of varied axial lengths of such a defect along the circumference of the pipeline is used in this paper as the characteristic value of actual axial length for comparison purpose. The experimental results of artificial defects and real corrosion in sample pipes were considered in this paper to demonstrate the effectiveness of the proposed method

  20. Application of the risk based inspection in chemical and nuclear installations: a critical evaluation

    International Nuclear Information System (INIS)

    Sousa, Anna Leticia Barbosa de

    2004-01-01

    Risk-based Inspection (RBI) has arisen as an opportunity for the industry to give a specific treatment to items as equipment integrity, failures consequences and the level of risk of each piece of equipment in the inspection programs definitions. Risk-based inspection programs are replacing the traditional ones based on prescriptive requirements, for both the oil and nuclear industries. The aim of this thesis is to demonstrate how the nuclear industry has gotten over several difficulties in implementing risk-based programs considering that its safety design and regulations have traditionally been based on deterministic and prescriptive criteria and requirements. During the development of the work, the study has shown how the absence of a rigid regulation favored the dissemination of RBI diffusion in the oil industry, mainly in the USA, where such industries do not face those difficulties found by the European plants, as long as it is well known that in Europe there are complex interrelations among documents from different countries with diversity of regulation procedures. (author)

  1. Bases en technique du vide

    CERN Document Server

    Rommel, Guy

    2017-01-01

    Cette seconde édition, 20 ans après la première, devrait continuer à aider les techniciens pour la réalisation de leur système de vide. La technologie du vide est utilisée, à présent, dans de nombreux domaines très différents les uns des autres et avec des matériels très fiables. Or, elle est souvent bien peu étudiée, de plus, c'est une discipline où le savoir-faire prend tout son sens. Malheureusement la transmission par des ingénieurs et techniciens expérimentés ne se fait plus ou trop rapidement. La technologie du vide fait appel à la physique, à la chimie, à la mécanique, à la métallurgie, au dessin industriel, à l'électronique, à la thermique, etc. Cette discipline demande donc de maîtriser des techniques de domaines très divers, et ce n'est pas chose facile. Chaque installation est en soi un cas particulier avec ses besoins, sa façon de traiter les matériaux et celle d'utiliser les matériels. Les systèmes de vide sont parfois copiés d'un laboratoire à un autre et le...

  2. Crack-depth effects in the cylindrically guided wave technique for bolt and pump-shaft inspections

    International Nuclear Information System (INIS)

    Tsai, Y.M.; Liu, S.N.; Light, G.M.

    1991-01-01

    Nuclear power plants have experienced the failures of bolts and pump shafts. The industry is concerned about nondestructive evaluation (NDE) techniques that can be applied to these components. The cylindrically guided wave technique (CGWT) has been developed to detect the simulated circumferential defects in long bolts and studs. The ultrasonic CGWT employs the zero-degree longitudinal waves constrained to travel within the boundary of the components with cylindrical shape during inspection. When longitudinal waves are guided to travel along a cylinder, and impinge onto a circumferential defect, the waves are scattered at the crack on the cylinder surface. In this work, the wave scattering at the circumferential crack on a long cylinder is investigated. The transfer factor of the scattered waves is calculated for a wide range of frequency spectra. The scattered waveform at a distance away from a crack is calculated. The effect that crack depth exerts to the waveform in CGWT is shown. CGWT signals, waveform calculation and so on are reported. (K.I.)

  3. Development of ultrasonic testing DSP inspection technique for class 1 system piping in nuclear power plants

    International Nuclear Information System (INIS)

    Ku, Kil Mo; Lee, Ik Whan; Jeong, Hyun Kyu; Park, Moon Ho; Heo, Hyung; Kong, Un Sik

    1996-01-01

    The purpose of this study is to explore the utilization of new constant-Q SSP in ultrasonic NDE. Various engineering problems are reviewed, and suggestions for implementation of the technique are provided. The filters of new Constant-Q SSP centered on frequency points, and normalized type of the filtered signals was not nromalized. The new Constant-Q SSP uses the frequency-dependant response of the interfering coherent noise produced by unresolvable scatters in the resolution range cell of a transducer. It is implemented by splitting the frequency spectrum of the received signal with gaussian bandpass filters. The principles of the SSP and the various optimization algorithms are recalled, and the conventional decomposition method for the SSP was presented

  4. Development of inspection techniques for quantitatively measuring surface contamination on SRM hardware

    Science.gov (United States)

    Law, R. D.

    1989-01-01

    A contaminant is any material or substance which is potentially undesirable or which may adversely affect any part, component, or assembly. Contamination control of SRM hardware surfaces is a serious concern, for both Thiokol and NASA, with particular concern for contaminants which may adversely affect bonding surfaces. The purpose of this study is to develop laboratory analytical techniques which will make it possible to certify the cleanliness of any designated surface, with special focus on particulates (dust, dirt, lint, etc.), oils (hydrocarbons, silicones, plasticizers, etc.), and greases (HD-2, fluorocarbon grease, etc.). The hardware surfaces of concern will include D6AC steel, aluminum alloys, anodized aluminum alloys, glass/phenolic, carbon/phenolic, NBR/asbestos-silica, and EPDM rubber.

  5. Development of ultrasonic testing DSP inspection technique for class 1 system piping in nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Ku, Kil Mo; Lee, Ik Whan; Jeong, Hyun Kyu; Park, Moon Ho; Heo, Hyung; Kong, Un Sik [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1996-01-01

    The purpose of this study is to explore the utilization of new constant-Q SSP in ultrasonic NDE. Various engineering problems are reviewed, and suggestions for implementation of the technique are provided. The filters of new Constant-Q SSP centered on frequency points, and normalized type of the filtered signals was not nromalized. The new Constant-Q SSP uses the frequency-dependant response of the interfering coherent noise produced by unresolvable scatters in the resolution range cell of a transducer. It is implemented by splitting the frequency spectrum of the received signal with gaussian bandpass filters. The principles of the SSP and the various optimization algorithms are recalled, and the conventional decomposition method for the SSP was presented.

  6. Summary Report - Inspections of DoD Facilities and Military Housing and Audits of Base Operations and Support Services Contracts

    Science.gov (United States)

    2016-10-14

    drinking water quality, radon, pest management, mold, and radiation. In addition, during the Japan and Korea inspections, we evaluated the management...Components responsible for facilities management conduct such analyses and use the results of these root cause analyses to improve facility management...water quality, radon, mold, pest infestation, lead-based paint, asbestos, and radiation) requirements. These inspections should be conducted by

  7. Reliability-Based Planning of Inspection, Operation and Maintenance for Offshore Oil & Gas Structures and Wind Turbines

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard

    2011-01-01

    Reliability-based cost-optimal planning of inspection, maintenance and operation has many applications. In this paper applications for planning of inspections for oil & gas jacket structures and of operation and maintenance of offshore wind turbines are described and illustrated by examples....

  8. Enhancement of the reliability of automated ultrasonic inspections using tools of quantitative NDT

    International Nuclear Information System (INIS)

    Kappes, W.; Baehr, W.; Kroening, M.; Schmitz, V.

    1994-01-01

    To achieve reliable test results from automated ultrasonic inspection of safety related components, optimization and integral consideration of the various inspection stages - inspection planning, inspection performance and evaluation of results - are indispensable. For this purpose, a large potential of methods is available: advanced measurement techniques, mathematical-numerical modelling processes, artificial intelligence tools, data bases and CAD systems. The potential inherent in these methods to enhance inspection reliability is outlined by way of different applications. (orig.) [de

  9. Development of nuclear fuel rod inspection technique using ultrasonic resonance phenomenon

    International Nuclear Information System (INIS)

    Choi, Myoung Seon; Joo, Young Sang; Jung, Hyun Kyu; Cheong, Yong Moo.

    1997-02-01

    The scattering of plane acoustic waves normally incident on a multilayered cylindrical shell has been formulated using the global matrix approach. And a simple way to formulate the non-resonant background component in the field scattered by an empty elastic shell has been found. This is to replace the surface admittance for the shell with the zero-frequency limit of the surface admittance for the analogous fluid shell (i.e., the shear wave speed in the elastic shell is set to zero). It has been shown that the background thus obtained is exact and applicable to shells of arbitrary thickness and material makeup, and over all frequencies and mode numbers. This way has been also applied to obtain the expressions of the backgrounds for multilayered shells. The resonant ultrasound spectroscopy system has been constructed to measure the resonance spectrum of a single fuel rod. The leak-defective fuel rod detection system of a laboratory scale has been also constructed. Particularly, all techniques and processes necessary for manufacturing the ultrasonic probe of thin (1.2 mm) strip type have been developed. (author). 38 refs., 34 figs

  10. Research on the Application of Risk-based Inspection for the Boiler System in Power Plant

    Science.gov (United States)

    Li, Henan

    2017-12-01

    Power plant boiler is one of the three main equipment of coal-fired power plants, is very tall to the requirement of the safe and stable operation, in a significant role in the whole system of thermal power generation, a risk-based inspection is a kind of pursuit of security and economy of unified system management idea and method, can effectively evaluate equipment risk and reduce the operational cost.

  11. Influence of turning Treatments on Al6061 by Offline Inspection Technique

    Science.gov (United States)

    Annigeri, Ulhas K.; Sandeep, K. L. G.; Prasanna Chaitanya, M.; Sairam Varma, G.; Datta, B. Arun

    2018-02-01

    Aluminium is mostly extracted from bauxite and is frequently being utilised in the manufacture of sea, land and air vehicles. Since, it has the merit of resistance to corrosion it is frequently being used in sea vehicles. Another outstanding merit of aluminium is its weight which is very less compared to other ferrous materials. In our study, we have selected Al6061 as the material and based on full factorial design the surface roughness has been observed with three base parameters speed, feed and depth of cut. A mathematical model has been developed to predict the surface roughness and also the dominant factor affecting the turning process has been determined. The plots such as main effects, interaction and Pareto chart have been analysed to give an effective conclusion to the process followed in the study. The purpose of these experiments to compare the effect of process treatments in all possible pairs to select the best treatment to the process has been done satisfactorily.

  12. The selection of ultrasonic transducers for inspection of pipeline girth welds. Vol. 3. Evaluation of the pitch-catch technique for examination of the body region

    Energy Technology Data Exchange (ETDEWEB)

    Glover, A G; Fingerhut, M P; Dorling, D V

    1988-10-01

    Research was conducted to develop an ultrasonic inspection design for the nondestructive evaluation of pipeline girth welds made by the mechanized gas metal arc (GMA) welding process for onshore and offshore pipeline construction. This report describes the work carried out to evaluate the performance to the pitch-catch technique with respect to its ability to examine the body region of mechanized GMA welds in 19.5 mm thick material. Evaluation of the pitch-catch technique was carried out on simulated and real weld defects. Results show that an inspection design method and criteria can be specified for the detection of lack of sidewall fusion defects in the body region of mechanized GMA welds. The criteria specified a pitch-catch technique using a 2.25 MHz 45{degrees} transmitter and a 2.25 MHz 55{degrees} receiver probe. A single pair of these transducers can inspect wall thickness from 9.7 mm to 23.0 mm. The pitch-catch technique evaluated on 19.5 mm wall thickness materials demonstrated that the detection goal of projected depth with a signal-to-noise ratio of greater than 12dB could be met, and that no problems occurred with false indications or missed defects. High sensitivities to small defects in the body region were obtained using a single pair of pitch-catch probes that inspected the body region as a single plane. 4 refs., 14 figs., 6 tabs.

  13. Bridging of inspection with corrosion management

    International Nuclear Information System (INIS)

    Zamaluddin Ali; Mohd Hawari Hassan; Rohana Jaafar

    2009-01-01

    Formerly, Inspection and Corrosion Engineers have less interaction and sharing of information to each other even they are working in the same plant or organization. Inspection finding either from visual inspection or NDT techniques rarely shared with corrosion engineers. Similarly corrosion engineers rarely discussed their corrosion prediction and potential damage mechanism with inspection engineers. A demanding request of more holistic plant safety and asset integrity promoted the introduction and implementation of Risk Based Inspection (RBI). RBI analysis demands the input mainly from both disciplines i.e. Inspection and Corrosion Engineers. Most of RBI methodologies are once-off analysis approach which also promoted once-off interaction between Inspection and Corrosion Engineers. PETRONAS has developed a methodology with supporting software, integrating both Inspection and Corrosion disciplines. PETRONAS Risk Based Inspection (PRBI) is intended to promote continuous integration of Inspection and Corrosion management of the plant through out the whole life cycle starting from the design stage to fabrication, operation and decommissions stage. (author)

  14. Development of a risk-based inservice inspection program for a liquid metal reactor

    International Nuclear Information System (INIS)

    King, R.W.; Buschman, H.W.

    1996-01-01

    The emerging application of risk-based assessment technology to the operation and maintenance of nuclear power plants holds considerable promise for improving efficiency and reducing operating costs. EBR-II is liquid-metal-cooled fast reactor which operated for thirty years before shutting down in September 1994 due to program termination. Prior to the shutdown of EBR-II, an in-service inspection (ISI) program was developed that exploited certain advantages of the liquid-metal reactor design, e.g., demonstrated passive response to plant upset events, low pressure primary coolant and compatibility of the coolant and reactor materials. Many of the systems cannot be inspected due to inaccessibility of the components. However, application of a risk-based approach provided the basis for reducing or eliminating inspections in some areas that would otherwise be required. Development and implementation of the risk-based ISI program was interrupted by the DOE-mandated shutdown of EBR-II, so the potential benefits of this approach in terms of reduced O and M costs have yet to be realized. Through the development of this program, however it is clear that there is potential for substantial cost-savings while improving the risk-profile of the facility through this approach

  15. PDBlocal: A web-based tool for local inspection of biological macromolecular 3D structures

    Directory of Open Access Journals (Sweden)

    Pan Wang

    2018-03-01

    Full Text Available Functional research on biological macromolecules must focus on specific local regions. PDBlocal is a web-based tool developed to overcome the limitations of traditional molecular visualization tools for three-dimensional (3D inspection of local regions. PDBlocal provides an intuitive and easy-to-manipulate web page interface and some new useful functions. It can keep local regions flashing, display sequence text that is dynamically consistent with the 3D structure in local appearance under multiple local manipulations, use two scenes to help users inspect the same local region with different statuses, list all historical manipulation statuses with a tree structure, allow users to annotate regions of interest, and save all historical statuses and other data to a web server for future research. PDBlocal has met expectations and shown satisfactory performance for both expert and novice users. This tool is available at http://labsystem.scuec.edu.cn/pdblocal/.

  16. Machine Vision based Micro-crack Inspection in Thin-film Solar Cell Panel

    Directory of Open Access Journals (Sweden)

    Zhang Yinong

    2014-09-01

    Full Text Available Thin film solar cell consists of various layers so the surface of solar cell shows heterogeneous textures. Because of this property the visual inspection of micro-crack is very difficult. In this paper, we propose the machine vision-based micro-crack detection scheme for thin film solar cell panel. In the proposed method, the crack edge detection is based on the application of diagonal-kernel and cross-kernel in parallel. Experimental results show that the proposed method has better performance of micro-crack detection than conventional anisotropic model based methods on a cross- kernel.

  17. Auxiliary feedwater system risk-based inspection guide for the North Anna nuclear power plants

    International Nuclear Information System (INIS)

    Nickolaus, J.R.; Moffitt, N.E.; Gore, B.F.; Vo, T.V.

    1992-10-01

    In a study sponsored by the US Nuclear regulatory Commission (NRC), Pacific Northwest Laboratory has developed and applied a methodology for deriving plant-specific risk-based inspection guidance for the auxiliary feedwater (AFW) system at pressurized water reactors that have not undergone probabilistic risk assessment (PRA). This methodology uses existing PRA results and plant operating experience information. Existing PRA-based inspection guidance information recently developed for the NRC for various plants was used to identify generic component failure modes. This information was then combined with plant-specific and industry-wide component information and failure data to identify failure modes and failure mechanisms for the AFW system at the selected plants. North Anna was selected as a plant for study. The product of this effort is a prioritized listing of AFW failures which have occurred at the plant and at other PWRs. This listing is intended for use by the NRC inspectors in preparation of inspection plans addressing AFW risk important components at the North Anna plant

  18. Auxiliary feedwater system risk-based inspection guide for the Palo Verde Nuclear Power Plant

    International Nuclear Information System (INIS)

    Bumgardner, J.D.; Moffitt, N.E.; Gore, B.F.; Vo, T.V.; Sloan, J.A.

    1993-02-01

    In a study sponsored by the US Nuclear Regulatory Commission (NRC), Pacific Northwest Laboratory has developed and applied a methodology for deriving plant-specific risk-based inspection guidance for the auxiliary feedwater (AFW) system at pressurized water reactors that have not undergone probabilistic risk assessment (PRA). This methodology uses existing PRA results and plant operating experience information. Existing PRA-based inspection guidance information recently developed for the NRC for various plants was used to identify generic component failure modes. This information was then combined with plant-specific and industry-wide component information and failure data to identify failure modes and failure mechanisms for the AFW system at the selected plants. Palo Verde was selected as one of a series of plants for study. The product of this effort is a prioritized listing of AFW failures which have occurred at the plant and at other PWRs. This listing is intended for use by NRC inspectors in the preparation of inspection plans addressing AFW risk-important components at the Palo Verde plants

  19. Auxiliary feedwater system risk-based inspection guide for the McGuire nuclear power plant

    International Nuclear Information System (INIS)

    Bumgardner, J.D.; Lloyd, R.C.; Moffitt, N.E.; Gore, B.F.; Vo, T.V.

    1994-05-01

    In a study sponsored by the US Nuclear Regulatory Commission (NRC), Pacific Northwest Laboratory has developed and applied a methodology for deriving plant-specific risk-based inspection guidance for the auxiliary feedwater (AFW) system at pressurized water reactors that have not undergone probabilistic risk assessment (PRA). This methodology uses existing PRA results and plant operating experience information. Existing PRA-based inspection guidance information recently developed for the NRC for various plants was used to identify generic component failure modes. This information was then combined with plant-specific and industry-wide component information and failure data to identify failure modes and failure mechanisms for the AFW system at the selected plants. McGuire was selected as one of a series of plants for study. The product of this effort is a prioritized listing of AFW failures which have occurred at the plant and at other PWRs. This listing is intended for use by NRC inspectors in the preparation of inspection plans addressing AFW risk-important components at the McGuire plant

  20. Auxiliary feedwater system risk-based inspection guide for the South Texas Project nuclear power plant

    International Nuclear Information System (INIS)

    Bumgardner, J.D.; Nickolaus, J.R.; Moffitt, N.E.; Gore, B.F.; Vo, T.V.

    1993-12-01

    In a study sponsored by the US Nuclear Regulatory Commission (NRC), Pacific Northwest Laboratory has developed and applied a methodology for deriving plant-specific risk-based inspection guidance for the auxiliary feedwater (AFW) system at pressurized water reactors that have not undergone probabilistic risk assessment (PRA). This methodology uses existing PRA results and plant operating experience information. Existing PRA-based inspection guidance information recently developed for the NRC for various plants was used to identify generic component failure modes. This information was then combined with plant-specific and industry-wide component information and failure data to identify failure modes and failure mechanisms for the AFW system at the selected plants. South Texas Project was selected as a plant for study. The product of this effort is a prioritized listing of AFW failures which have occurred at the plant and at other PWRs. This listing is intended for use by the NRC inspectors in preparation of inspection plans addressing AFW risk important components at the South Texas Project plant

  1. Auxiliary feedwater system risk-based inspection guide for the Maine Yankee Nuclear Power Plant

    International Nuclear Information System (INIS)

    Gore, B.F.; Vo, T.V.; Moffitt, N.E.; Bumgardner, J.D.

    1992-10-01

    In a study sponsored by the US Nuclear Regulatory Commission (NRC), Pacific Northwest Laboratory has developed and applied a methodology for deriving plant-specific risk-based inspection guidance for the auxiliary feedwater (AFW) system at pressurized water reactors that have not undergone probabilistic risk assessment (PRA). This methodology uses existing PRA results and plant operating experience information. Existing PRA-based inspection guidance information recently developed for the NRC for various plants was used to identify generic component failure modes. The information was then combined with plant-specific and industry-wide component information and failure data to identify failure modes and failure mechanisms for the AFW system at the selected plants. Maine Yankee was selected as one of a series of plants for study. ne product of this effort is a prioritized listing of AFW failures which have occurred at the plant and at other PWRs. This listing is intended for use by NRC inspectors in the preparation of inspection plans addressing AFW risk-important components at the Maine Yankee plant

  2. Auxiliary feedwater system risk-based inspection guide for the Byron and Braidwood nuclear power plants

    International Nuclear Information System (INIS)

    Moffitt, N.E.; Gore, B.F.; Vo, T.V.

    1991-07-01

    In a study sponsored by the US Nuclear Regulatory Commission (NRC), Pacific Northwest Laboratory has developed and applied a methodology for deriving plant-specific risk-based inspection guidance for the auxiliary feedwater (AFW) system at pressurized water reactors that have not undergone probabilistic risk assessment (PRA). This methodology uses existing PRA results and plant operating experience information. Existing PRA-based inspection guidance information recently developed for the NRC for various plants was used to identify generic component failure modes. This information was then combined with plant-specific and industry-wide component information and failure data to identify failure modes and failure mechanisms for the AFW system at the selected plants. Byron and Braidwood were selected for the fourth study in this program. The produce of this effort is a prioritized listing of AFW failures which have occurred at the plants and at other PWRs. This listing is intended for use by NRC inspectors in the preparation of inspection plans addressing AFW risk-important components at the Byron/Braidwood plants. 23 refs., 1 fig., 1 tab

  3. Auxiliary feedwater system risk-based inspection guide for the H. B. Robinson nuclear power plant

    International Nuclear Information System (INIS)

    Moffitt, N.E.; Lloyd, R.C.; Gore, B.F.; Vo, T.V.; Garner, L.W.

    1993-08-01

    In a study sponsored by the US Nuclear Regulatory Commission (NRC), Pacific Northwest Laboratory has developed and applied a methodology for deriving plant-specific risk-based inspection guidance for the auxiliary feedwater (AFW) system at pressurized water reactors that have not undergone probabilistic risk assessment (PRA). This methodology uses existing PRA results and plant operating experience information. Existing PRA-based inspection guidance information recently developed for the NRC for various plants was used to identify generic component failure modes. This information was then combined with plant-specific and industry-wide component information and failure data to identify failure modes and failure mechanisms for the AFW system at the selected plants. H. B. Robinson was selected as one of a series of plants for study. The product of this effort is a prioritized listing of AFW failures which have occurred at the plant and at other PWRs. This listing is intended for use by NRC inspectors in the preparation of inspection plans addressing AFW risk-important components at the H. B. Robinson plant

  4. Auxiliary feedwater system risk-based inspection guide for the Point Beach nuclear power plant

    International Nuclear Information System (INIS)

    Lloyd, R.C.; Moffitt, N.E.; Gore, B.F.; Vo, T.V.; Vehec, T.A.

    1993-02-01

    In a study sponsored by the US Nuclear Regulatory Commission (NRC), Pacific Northwest Laboratory has developed and applied a methodology for deriving plant-specific risk-based inspection guidance for the auxiliary feedwater (AFW) system at pressurized water reactors that have not undergone probabilistic risk assessment (PRA). This methodology uses existing PRA results and plant operating experience information. Existing PRA-based inspection guidance information recently developed for the NRC for various plants was used to identify generic component failure modes. This information was then combined with plant-specific and industry-wide component information and failure data to identify failure modes and failure mechanisms for the AFW system at the selected plants. Point Beach was selected as one of a series of plants for study. The product of this effort is a prioritized listing of AFW failures which have occurred at the plant and at other PWRS. This listing is intended for use by NRC inspectors in the preparation of inspection plans addressing AFW risk-important components at the Point Beach plant

  5. Auxiliary feedwater system risk-based inspection guide for the Ginna Nuclear Power Plant

    International Nuclear Information System (INIS)

    Pugh, R.; Gore, B.F.; Vo, T.V.; Moffitt, N.E.

    1991-09-01

    In a study sponsored by the US Nuclear Regulatory Commission (NRC), Pacific Northwest Laboratory has developed and applied a methodology for deriving plant-specific risk-based inspection guidance for the auxiliary feedwater (AFW) system at pressurized water reactors that have not undergone probabilistic risk assessment (PRA). This methodology uses existing PRA results and plant operating experience information. Existing PRA-based inspection guidance information recently developed for the NRC for various plants was used to identify generic component failure modes. This information was then combined with plant-specific and industry-wide component information and failure data to identify failure modes and failure mechanisms for the AFW system at the selected plants. Ginna was selected as the eighth plant for study. The product of this effort is a prioritized listing of AFW failures which have occurred at the plant and at other PWRs. This listing is intended for use by NRC inspectors in the preparation of inspection plans addressing AFW risk-important components at the Ginna plant. 23 refs., 1 fig., 1 tab

  6. Neural network Hilbert transform based filtered backprojection for fast inline x-ray inspection

    Science.gov (United States)

    Janssens, Eline; De Beenhouwer, Jan; Van Dael, Mattias; De Schryver, Thomas; Van Hoorebeke, Luc; Verboven, Pieter; Nicolai, Bart; Sijbers, Jan

    2018-03-01

    X-ray imaging is an important tool for quality control since it allows to inspect the interior of products in a non-destructive way. Conventional x-ray imaging, however, is slow and expensive. Inline x-ray inspection, on the other hand, can pave the way towards fast and individual quality control, provided that a sufficiently high throughput can be achieved at a minimal cost. To meet these criteria, an inline inspection acquisition geometry is proposed where the object moves and rotates on a conveyor belt while it passes a fixed source and detector. Moreover, for this acquisition geometry, a new neural-network-based reconstruction algorithm is introduced: the neural network Hilbert transform based filtered backprojection. The proposed algorithm is evaluated both on simulated and real inline x-ray data and has shown to generate high quality reconstructions of 400  ×  400 reconstruction pixels within 200 ms, thereby meeting the high throughput criteria.

  7. A preventive maintenance model with a two-level inspection policy based on a three-stage failure process

    International Nuclear Information System (INIS)

    Wang, Wenbin; Zhao, Fei; Peng, Rui

    2014-01-01

    Inspection is always an important preventive maintenance (PM) activity and can have different depths and cover all or part of plant systems. This paper introduces a two-level inspection policy model for a single component plant system based on a three-stage failure process. Such a failure process divides the system′s life into three stages: good, minor defective and severe defective stages. The first level of inspection, the minor inspection, can only identify the minor defective stage with a certain probability, but can always reveal the severe defective stage. The major inspection can however identify both defective stages perfectly. Once the system is found to be in the minor defective stage, a shortened inspection interval is adopted. If however the system is found to be in the severe defective stage, we may delay the maintenance action if the time to the next planned PM window is less than a threshold level, but otherwise, replace immediately. This corresponds to the well adopted maintenance policy in practice such as periodic inspections with planned PMs. A numerical example is presented to demonstrate the proposed model by comparing with other models. - Highlights: • The system′s deterioration goes through a three-stage process, namely, normal, minor defective and severe defective. • Two levels of inspections are proposed, e.g., minor and major inspections. • Once the minor defective stage is found, instead of taking a maintenance action, a shortened inspection interval is recommended. • When the severe defective stage is found, we delay the maintenance according to the threshold to the next PM. • The decision variables are the inspection intervals and the threshold to PM

  8. The SAFT-UT (synthetic aperture focusing technique for ultrasonic testing) real-time inspection system: Operational principles and implementation

    Energy Technology Data Exchange (ETDEWEB)

    Hall, T. E.; Reid, L. D.; Doctor, S. R.

    1988-06-01

    This document provides a technical description of the real-time imaging system developed for rapid flaw detection and characterization utilizing the synthetic aperture focusing technique for ultrasonic testing (SAFT-UT). The complete fieldable system has been designed to perform inservice inspection of light-water reactor components. Software was written on a DEC LSI 11/23 computer system to control data collection. The unprocessed data is transferred to a VAX 11/730 host computer to perform data processing and image display tasks. A parallel architecture peripheral to the host computer, referred to as the Real-Time SAFT Processor, rapidly performs the SAFT processing function. From the host's point of view, this device operates on the SAFT data in such a way that one may consider it to be a specialized or SAFT array processor. A guide to SAFT-UT theory and conventions is included, along with a detailed description of the operation of the software, how to install the software, and a detailed hardware description.

  9. Vibration measurement-based simple technique for damage detection of truss bridges: A case study

    Directory of Open Access Journals (Sweden)

    Sudath C. Siriwardane

    2015-10-01

    Full Text Available The bridges experience increasing traffic volume and weight, deteriorating of components and large number of stress cycles. Therefore, assessment of the current condition of steel railway bridges becomes necessary. Most of the commonly available approaches for structural health monitoring are based on visual inspection and non-destructive testing methods. The visual inspection is unreliable as those depend on uncertainty behind inspectors and their experience. Also, the non-destructive testing methods are found to be expensive. Therefore, recent researches have noticed that dynamic modal parameters or vibration measurement-based structural health monitoring methods are economical and may also provide more realistic predictions to damage state of civil infrastructure. Therefore this paper proposes a simple technique to locate the damage region of railway truss bridges based on measured modal parameters. The technique is discussed with a case study. Initially paper describes the details of considered railway bridge. Then observations of visual inspection, material testing and in situ load testing are discussed under separate sections. Development of validated finite element model of the considered bridge is comprehensively discussed. Hence, variations of modal parameters versus position of the damage are plotted. These plots are considered as the main reference for locating the damage of the railway bridge in future periodical inspection by comparing the measured corresponding modal parameters. Finally the procedure of periodical vibration measurement and damage locating technique are clearly illustrated.

  10. A brick-architecture-based mobile under-vehicle inspection system

    Science.gov (United States)

    Qian, Cheng; Page, David; Koschan, Andreas; Abidi, Mongi

    2005-05-01

    In this paper, a mobile scanning system for real-time under-vehicle inspection is presented, which is founded on a "Brick" architecture. In this "Brick" architecture, the inspection system is basically decomposed into bricks of three kinds: sensing, mobility, and computing. These bricks are physically and logically independent and communicate with each other by wireless communication. Each brick is mainly composed by five modules: data acquisition, data processing, data transmission, power, and self-management. These five modules can be further decomposed into submodules where the function and the interface are well-defined. Based on this architecture, the system is built by four bricks: two sensing bricks consisting of a range scanner and a line CCD, one mobility brick, and one computing brick. The sensing bricks capture geometric data and texture data of the under-vehicle scene, while the mobility brick provides positioning data along the motion path. Data of these three modalities are transmitted to the computing brick where they are fused and reconstruct a 3D under-vehicle model for visualization and danger inspection. This system has been successfully used in several military applications and proved to be an effective safer method for national security.

  11. Corrosion Assessment by Using Risk-Based Inspection Method for Petrochemical Plant - Practical Experience

    International Nuclear Information System (INIS)

    Choi, Song Chun; Song, Ki Hun

    2009-01-01

    Corrosion assessment has a number of uses but the use considered here is as a precursor to Risk-Based Inspection (RBI) planning. Systematic methods consisting of technical modules of RBI program were used to assess the effect of specific corrosion mechanism on the probability of failure in equipment of petrochemical plants. Especially in part of the damage and corrosion assessment, screening step involved evaluating the combinations of process conditions and construction materials for each equipment item in order to determine which damage mechanisms are potentially active. For general internal corrosion, either API 510 or API 570 was applied as the damage rate in the calculation to determine the remaining life and inspection frequency. In some cases, a measured rate of corrosion may not be available. The technical modules of RBI program employ default values for corrosion, typically derived from published data or from experience with similar processes, for use until inspection results are available. This paper describes the case study of corrosion and damage assessment by using RBI methodology in petrochemical plant. Specifically, this paper reports the methodology and the results of its application to the petrochemical units using the KGS-RBI TM program, developed by the Korea Gas Safety Corporation to suit Korean situation in conformity with API 581 Codes

  12. Review of P-scan computer-based ultrasonic inservice inspection system. Supplement 1

    International Nuclear Information System (INIS)

    Harris, R.V. Jr.; Angel, L.J.

    1995-12-01

    This Supplement reviews the P-scan system, a computer-based ultrasonic system used for inservice inspection of piping and other components in nuclear power plants. The Supplement was prepared using the methodology described in detail in Appendix A of NUREG/CR-5985, and is based on one month of using the system in a laboratory. This Supplement describes and characterizes: computer system, ultrasonic components, and mechanical components; scanning, detection, digitizing, imaging, data interpretation, operator interaction, data handling, and record-keeping. It includes a general description, a review checklist, and detailed results of all tests performed

  13. Under-Sodium-Viewing as one technique for periodic inspections in sodium-cooled fast reactors-- possibilities and limits

    International Nuclear Information System (INIS)

    Weiss, H.

    1979-07-01

    Periodic inspections are gaining increasingly technical importance for fast sodium cooled reactors. Among others the reactor tank and its internals have to be inspected, whereby licensing experts partly are requesting the standards of Light Water Reactors. This leads to difficulties in sodium cooled reactors because of the non-transparent coolant sodium and their compact structure. In order to avoid the complete dumping of the sodium, the under sodium viewing shall be applied besides other inspection methods. Since this is a new method, which is still in its development phase, this report presents and discusses the technical and physical basis and outlines possibilities and limits [de

  14. Developing an App by Exploiting Web-Based Mobile Technology to Inspect Controlled Substances in Patient Care Units

    Science.gov (United States)

    2017-01-01

    We selected iOS in this study as the App operation system, Objective-C as the programming language, and Oracle as the database to develop an App to inspect controlled substances in patient care units. Using a web-enabled smartphone, pharmacist inspection can be performed on site and the inspection result can be directly recorded into HIS through the Internet, so human error of data translation can be minimized and the work efficiency and data processing can be improved. This system not only is fast and convenient compared to the conventional paperwork, but also provides data security and accuracy. In addition, there are several features to increase inspecting quality: (1) accuracy of drug appearance, (2) foolproof mechanism to avoid input errors or miss, (3) automatic data conversion without human judgments, (4) online alarm of expiry date, and (5) instant inspection result to show not meted items. This study has successfully turned paper-based medication inspection into inspection using a web-based mobile device. PMID:28286761

  15. Point-based POMDP Risk Based Inspection of Offshore Wind Substructures

    DEFF Research Database (Denmark)

    Morato, Pablo G.; Mai, Quang A.; Rigo, Philippe

    2018-01-01

    This article presents a novel methodology to select the optimal maintenance strategy of an offshore wind structural component, providing a flexible and reliable support to decision-making and balancing inspection, repair and failure costs. The procedure to create a “Point-Based” Partially...

  16. High Pressure Coolant Injection (HPCI) system risk-based inspection guide: Pilgrim Nuclear Power Station

    International Nuclear Information System (INIS)

    Shier, W.; Gunther, W.

    1992-10-01

    A review of the operating experience for the High Pressure Coolant Injection (HPCI) system at the Pilgrim Nuclear Power Station is described in this report. The information for this review was obtained from Pilgrim Licensee Event Reports (LERs) that were generated between 1980 and 1989. These LERs have been categorized into 23 failure modes that have been prioritized based on probabilistic risk assessment considerations. In addition, the results of the Pilgrim operating experience review have been compared with the results of of a similar, industry wide operating experience review. this comparison provides an indication of areas in the Pilgrim HPCI system that should be given increased attention in the prioritization of inspection resources

  17. High Pressure Coolant Injection (HPCI) System Risk-Based Inspection Guide for Browns Ferry Nuclear Power Station

    International Nuclear Information System (INIS)

    Wong, S.; DiBiasio, A.; Gunther, W.

    1993-09-01

    The High Pressure Coolant Injection (HPCI) system has been examined from a risk perspective. A System Risk-Based Inspection Guide (S-RIG) has been developed as an aid to HPCI system inspections at the Browns Ferry Nuclear Power Plant, Units 1, 2 and 3. The role of. the HPCI system in mitigating accidents is discussed in this S-RIG, along with insights on identified risk-based failure modes which could prevent proper operation of the system. The S-RIG provides a review of industry-wide operating experience, including plant-specific illustrative examples to augment the PRA and operational considerations in identifying a catalogue of basic PRA failure modes for the HPCI system. It is designed to be used as a reference for routine inspections, self-initiated safety system functional inspections (SSFIs), and the evaluation of risk significance of component failures at the nuclear power plant

  18. High Pressure Coolant Injection (HPCI) System Risk-Based Inspection Guide for Browns Ferry Nuclear Power Station

    Energy Technology Data Exchange (ETDEWEB)

    Wong, S.; DiBiasio, A.; Gunther, W. [Brookhaven National Lab., Upton, NY (United States)

    1993-09-01

    The High Pressure Coolant Injection (HPCI) system has been examined from a risk perspective. A System Risk-Based Inspection Guide (S-RIG) has been developed as an aid to HPCI system inspections at the Browns Ferry Nuclear Power Plant, Units 1, 2 and 3. The role of. the HPCI system in mitigating accidents is discussed in this S-RIG, along with insights on identified risk-based failure modes which could prevent proper operation of the system. The S-RIG provides a review of industry-wide operating experience, including plant-specific illustrative examples to augment the PRA and operational considerations in identifying a catalogue of basic PRA failure modes for the HPCI system. It is designed to be used as a reference for routine inspections, self-initiated safety system functional inspections (SSFIs), and the evaluation of risk significance of component failures at the nuclear power plant.

  19. Composite Techniques Based Color Image Compression

    Directory of Open Access Journals (Sweden)

    Zainab Ibrahim Abood

    2017-03-01

    Full Text Available Compression for color image is now necessary for transmission and storage in the data bases since the color gives a pleasing nature and natural for any object, so three composite techniques based color image compression is implemented to achieve image with high compression, no loss in original image, better performance and good image quality. These techniques are composite stationary wavelet technique (S, composite wavelet technique (W and composite multi-wavelet technique (M. For the high energy sub-band of the 3rd level of each composite transform in each composite technique, the compression parameters are calculated. The best composite transform among the 27 types is the three levels of multi-wavelet transform (MMM in M technique which has the highest values of energy (En and compression ratio (CR and least values of bit per pixel (bpp, time (T and rate distortion R(D. Also the values of the compression parameters of the color image are nearly the same as the average values of the compression parameters of the three bands of the same image.

  20. A multi-component and multi-failure mode inspection model based on the delay time concept

    International Nuclear Information System (INIS)

    Wang Wenbin; Banjevic, Dragan; Pecht, Michael

    2010-01-01

    The delay time concept and the techniques developed for modelling and optimising plant inspection practices have been reported in many papers and case studies. For a system comprised of many components and subject to many different failure modes, one of the most convenient ways to model the inspection and failure processes is to use a stochastic point process for defect arrivals and a common delay time distribution for the duration between defect the arrival and failure of all defects. This is an approximation, but has been proven to be valid when the number of components is large. However, for a system with just a few key components and subject to few major failure modes, the approximation may be poor. In this paper, a model is developed to address this situation, where each component and failure mode is modelled individually and then pooled together to form the system inspection model. Since inspections are usually scheduled for the whole system rather than individual components, we then formulate the inspection model when the time to the next inspection from the point of a component failure renewal is random. This imposes some complication to the model, and an asymptotic solution was found. Simulation algorithms have also been proposed as a comparison to the analytical results. A numerical example is presented to demonstrate the model.

  1. Optimizing image-based patterned defect inspection through FDTD simulations at multiple ultraviolet wavelengths

    Science.gov (United States)

    Barnes, Bryan M.; Zhou, Hui; Henn, Mark-Alexander; Sohn, Martin Y.; Silver, Richard M.

    2017-06-01

    The sizes of non-negligible defects in the patterning of a semiconductor device continue to decrease as the dimensions for these devices are reduced. These "killer defects" disrupt the performance of the device and must be adequately controlled during manufacturing, and new solutions are required to improve optics-based defect inspection. To this end, our group has reported [Barnes et al., Proc. SPIE 1014516 (2017)] our initial five-wavelength simulation study, evaluating the extensibility of defect inspection by reducing the inspection wavelength from a deep-ultraviolet wavelength to wavelengths in the vacuum ultraviolet and the extreme ultraviolet. In that study, a 47 nm wavelength yielded enhancements in the signal to noise (SNR) by a factor of five compared to longer wavelengths and in the differential intensities by as much as three orders-of-magnitude compared to 13 nm. This paper briefly reviews these recent findings and investigates the possible sources for these disparities between results at 13 nm and 47 nm wavelengths. Our in-house finite-difference time-domain code (FDTD) is tested in both two and three dimensions to determine how computational conditions contributed to the results. A modified geometry and materials stack is presented that offers a second viewpoint of defect detectability as functions of wavelength, polarization, and defect type. Reapplication of the initial SNR-based defect metric again yields no detection of a defect at λ = 13 nm, but additional image preprocessing now enables the computation of the SNR for λ = 13 nm simulated images and has led to a revised defect metric that allows comparisons at all five wavelengths.

  2. A study on laser-based ultrasonic technique by the use of guided wave tomographic imaging

    Energy Technology Data Exchange (ETDEWEB)

    Park, Junpil, E-mail: jpp@pusan.ac.kr; Lim, Juyoung, E-mail: jpp@pusan.ac.kr [Graduate school, School of Mechanical Engineering, Pusan National University (Korea, Republic of); Cho, Younho [School of Mechanical Engineering, Pusan National University (Korea, Republic of); Krishnaswamy, Sridhar [Center for Quality Engineering and Failure Prevention, Northwestern University, Evanston, IL (United States)

    2015-03-31

    Guided wave tests are impractical for investigating specimens with limited accessibility and coarse surfaces or geometrically complicated features. A non-contact setup with a laser ultrasonic transmitter and receiver is the classic attractive for guided wave inspection. The present work was done to develop a non-contact guided-wave tomography technique by laser ultrasonic technique in a plate-like structure. A method for Lam wave generation and detection in an aluminum plate with a pulse laser ultrasonic transmitter and a Michelson interferometer receiver has been developed. In the images obtained by laser scanning, the defect shape and area showed good agreement with the actual defect. The proposed approach can be used as a non-contact-based online inspection and monitoring technique.

  3. Risk-based maintenance-Techniques and applications

    International Nuclear Information System (INIS)

    Arunraj, N.S.; Maiti, J.

    2007-01-01

    Plant and equipment, however well designed, will not remain safe or reliable if it is not maintained. The general objective of the maintenance process is to make use of the knowledge of failures and accidents to achieve the possible safety with the lowest possible cost. The concept of risk-based maintenance was developed to inspect the high-risk components usually with greater frequency and thoroughness and to maintain in a greater manner, to achieve tolerable risk criteria. Risk-based maintenance methodology provides a tool for maintenance planning and decision making to reduce the probability of failure of equipment and the consequences of failure. In this paper, the risk analysis and risk-based maintenance methodologies were identified and classified into suitable classes. The factors affecting the quality of risk analysis were identified and analyzed. The applications, input data and output data were studied to understand their functioning and efficiency. The review showed that there is no unique way to perform risk analysis and risk-based maintenance. The use of suitable techniques and methodologies, careful investigation during the risk analysis phase, and its detailed and structured results are necessary to make proper risk-based maintenance decisions

  4. Advances in model-based software for simulating ultrasonic immersion inspections of metal components

    Science.gov (United States)

    Chiou, Chien-Ping; Margetan, Frank J.; Taylor, Jared L.; Engle, Brady J.; Roberts, Ronald A.

    2018-04-01

    Under the sponsorship of the National Science Foundation's Industry/University Cooperative Research Center at ISU, an effort was initiated in 2015 to repackage existing research-grade software into user-friendly tools for the rapid estimation of signal-to-noise ratio (SNR) for ultrasonic inspections of metals. The software combines: (1) a Python-based graphical user interface for specifying an inspection scenario and displaying results; and (2) a Fortran-based engine for computing defect signals and backscattered grain noise characteristics. The later makes use the Thompson-Gray measurement model for the response from an internal defect, and the Thompson-Margetan independent scatterer model for backscattered grain noise. This paper, the third in the series [1-2], provides an overview of the ongoing modeling effort with emphasis on recent developments. These include the ability to: (1) treat microstructures where grain size, shape and tilt relative to the incident sound direction can all vary with depth; and (2) simulate C-scans of defect signals in the presence of backscattered grain noise. The simulation software can now treat both normal and oblique-incidence immersion inspections of curved metal components. Both longitudinal and shear-wave inspections are treated. The model transducer can either be planar, spherically-focused, or bi-cylindrically-focused. A calibration (or reference) signal is required and is used to deduce the measurement system efficiency function. This can be "invented" by the software using center frequency and bandwidth information specified by the user, or, alternatively, a measured calibration signal can be used. Defect types include flat-bottomed-hole reference reflectors, and spherical pores and inclusions. Simulation outputs include estimated defect signal amplitudes, root-mean-square values of grain noise amplitudes, and SNR as functions of the depth of the defect within the metal component. At any particular depth, the user can view

  5. Low-Cost Impact Detection and Location for Automated Inspections of 3D Metallic Based Structures

    Directory of Open Access Journals (Sweden)

    Carlos Morón

    2015-05-01

    Full Text Available This paper describes a new low-cost means to detect and locate mechanical impacts (collisions on a 3D metal-based structure. We employ the simple and reasonably hypothesis that the use of a homogeneous material will allow certain details of the impact to be automatically determined by measuring the time delays of acoustic wave propagation throughout the 3D structure. The location of strategic piezoelectric sensors on the structure and an electronic-computerized system has allowed us to determine the instant and position at which the impact is produced. The proposed automatic system allows us to fully integrate impact point detection and the task of inspecting the point or zone at which this impact occurs. What is more, the proposed method can be easily integrated into a robot-based inspection system capable of moving over 3D metallic structures, thus avoiding (or minimizing the need for direct human intervention. Experimental results are provided to show the effectiveness of the proposed approach.

  6. The ASME research task force on risk-based in-service inspection

    International Nuclear Information System (INIS)

    Balkey, K.R.; Chapman, O.J.V.

    1997-01-01

    The use of risk-based methods in the development of in-service inspection (ISI) and in-service testing (IST) programs for nuclear power plant and other industrial applications has been studied for the last several years through the American Society of Mechanical Engineers Centre for Research and Technology Development (ASME 1991, 1992, 1994, 1996). The results of this work are being used as a foundation to develop specific requirements for implementation of risk-based technology in ASME Codes and Standards, regulatory requirements and industry programs both in the U.S. and other countries. This paper provides a brief overview of the ASME Research Methodology and how it has been adapted for application to the inspection of piping within the USA. It also relates how the reliability of nondestructive examination (NDE) methods for pressure boundary components can impact the risk and discusses the relationship between this and NDE qualification/demonstration now being implemented in Europe and the USA. (orig.)

  7. Real-time distortion correction for visual inspection systems based on FPGA

    Science.gov (United States)

    Liang, Danhua; Zhang, Zhaoxia; Chen, Xiaodong; Yu, Daoyin

    2008-03-01

    Visual inspection is a kind of new technology based on the research of computer vision, which focuses on the measurement of the object's geometry and location. It can be widely used in online measurement, and other real-time measurement process. Because of the defects of the traditional visual inspection, a new visual detection mode -all-digital intelligent acquisition and transmission is presented. The image processing, including filtering, image compression, binarization, edge detection and distortion correction, can be completed in the programmable devices -FPGA. As the wide-field angle lens is adopted in the system, the output images have serious distortion. Limited by the calculating speed of computer, software can only correct the distortion of static images but not the distortion of dynamic images. To reach the real-time need, we design a distortion correction system based on FPGA. The method of hardware distortion correction is that the spatial correction data are calculated first under software circumstance, then converted into the address of hardware storage and stored in the hardware look-up table, through which data can be read out to correct gray level. The major benefit using FPGA is that the same circuit can be used for other circularly symmetric wide-angle lenses without being modified.

  8. FPGA based image processing for optical surface inspection with real time constraints

    Science.gov (United States)

    Hasani, Ylber; Bodenstorfer, Ernst; Brodersen, Jörg; Mayer, Konrad J.

    2015-02-01

    Today, high-quality printing products like banknotes, stamps, or vouchers, are automatically checked by optical surface inspection systems. In a typical optical surface inspection system, several digital cameras acquire the printing products with fine resolution from different viewing angles and at multiple wavelengths of the visible and also near infrared spectrum of light. The cameras deliver data streams with a huge amount of image data that have to be processed by an image processing system in real time. Due to the printing industry's demand for higher throughput together with the necessity to check finer details of the print and its security features, the data rates to be processed tend to explode. In this contribution, a solution is proposed, where the image processing load is distributed between FPGAs and digital signal processors (DSPs) in such a way that the strengths of both technologies can be exploited. The focus lies upon the implementation of image processing algorithms in an FPGA and its advantages. In the presented application, FPGAbased image-preprocessing enables real-time implementation of an optical color surface inspection system with a spatial resolution of 100 μm and for object speeds over 10 m/s. For the implementation of image processing algorithms in the FPGA, pipeline parallelism with clock frequencies up to 150 MHz together with spatial parallelism based on multiple instantiations of modules for parallel processing of multiple data streams are exploited for the processing of image data of two cameras and three color channels. Due to their flexibility and their fast response times, it is shown that FPGAs are ideally suited for realizing a configurable all-digital PLL for the processing of camera line-trigger signals with frequencies about 100 kHz, using pure synchronous digital circuit design.

  9. IMAGE ANALYSIS BASED ON EDGE DETECTION TECHNIQUES

    Institute of Scientific and Technical Information of China (English)

    纳瑟; 刘重庆

    2002-01-01

    A method that incorporates edge detection technique, Markov Random field (MRF), watershed segmentation and merging techniques was presented for performing image segmentation and edge detection tasks. It first applies edge detection technique to obtain a Difference In Strength (DIS) map. An initial segmented result is obtained based on K-means clustering technique and the minimum distance. Then the region process is modeled by MRF to obtain an image that contains different intensity regions. The gradient values are calculated and then the watershed technique is used. DIS calculation is used for each pixel to define all the edges (weak or strong) in the image. The DIS map is obtained. This help as priority knowledge to know the possibility of the region segmentation by the next step (MRF), which gives an image that has all the edges and regions information. In MRF model,gray level l, at pixel location i, in an image X, depends on the gray levels of neighboring pixels. The segmentation results are improved by using watershed algorithm. After all pixels of the segmented regions are processed, a map of primitive region with edges is generated. The edge map is obtained using a merge process based on averaged intensity mean values. A common edge detectors that work on (MRF) segmented image are used and the results are compared. The segmentation and edge detection result is one closed boundary per actual region in the image.

  10. Vision-Based Target Finding and Inspection of a Ground Target Using a Multirotor UAV System.

    Science.gov (United States)

    Hinas, Ajmal; Roberts, Jonathan M; Gonzalez, Felipe

    2017-12-17

    In this paper, a system that uses an algorithm for target detection and navigation and a multirotor Unmanned Aerial Vehicle (UAV) for finding a ground target and inspecting it closely is presented. The system can also be used for accurate and safe delivery of payloads or spot spraying applications in site-specific crop management. A downward-looking camera attached to a multirotor is used to find the target on the ground. The UAV descends to the target and hovers above the target for a few seconds to inspect the target. A high-level decision algorithm based on an OODA (observe, orient, decide, and act) loop was developed as a solution to address the problem. Navigation of the UAV was achieved by continuously sending local position messages to the autopilot via Mavros. The proposed system performed hovering above the target in three different stages: locate, descend, and hover. The system was tested in multiple trials, in simulations and outdoor tests, from heights of 10 m to 40 m. Results show that the system is highly reliable and robust to sensor errors, drift, and external disturbance.

  11. NFC based Inspection and Qualification Management (NIQM) System Preventing Counterfeit and Fraudulent Item

    International Nuclear Information System (INIS)

    Chang, Choong Koo; Kim, Young Joo

    2013-01-01

    Design, manufacturing, fabrication, transportation and installation of the devices and equipment for nuclear power plants shall be conducted under the thorough quality assurance program for the nuclear safety. However, from late in the 1980s, NRC began to issue a number of communications alerting licenses to issues involving counterfeit and fraudulent items. A number of incidents identified by the NRC in the 1980s and 1990s catalyzed the US nuclear industry to adopt standard precautions to guard against counterfeit items. The purpose of this paper is to develop the NFC (Near Field Communication) based Inspection and Qualification Management(NIQM) system preventing counterfeit and fraudulent items. NFC is one of the latest wireless communication technologies. As a short-range wireless connectivity technology, NFC offers safe-yet simple and intuitive-communication between electronic devices. As described above, NFC technology can be applied to the inspection and qualification management system very effectively to prevent counterfeit and fraudulent items. In addition, NIQM system can use existing data and information through the interface with legacy system

  12. NFC based Inspection and Qualification Management (NIQM) System Preventing Counterfeit and Fraudulent Item

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Choong Koo; Kim, Young Joo [KEPCO International Nuclear Graduate School, Ulsan (Korea, Republic of)

    2013-10-15

    Design, manufacturing, fabrication, transportation and installation of the devices and equipment for nuclear power plants shall be conducted under the thorough quality assurance program for the nuclear safety. However, from late in the 1980s, NRC began to issue a number of communications alerting licenses to issues involving counterfeit and fraudulent items. A number of incidents identified by the NRC in the 1980s and 1990s catalyzed the US nuclear industry to adopt standard precautions to guard against counterfeit items. The purpose of this paper is to develop the NFC (Near Field Communication) based Inspection and Qualification Management(NIQM) system preventing counterfeit and fraudulent items. NFC is one of the latest wireless communication technologies. As a short-range wireless connectivity technology, NFC offers safe-yet simple and intuitive-communication between electronic devices. As described above, NFC technology can be applied to the inspection and qualification management system very effectively to prevent counterfeit and fraudulent items. In addition, NIQM system can use existing data and information through the interface with legacy system.

  13. A Novel Defect Inspection Method for Semiconductor Wafer Based on Magneto-Optic Imaging

    Science.gov (United States)

    Pan, Z.; Chen, L.; Li, W.; Zhang, G.; Wu, P.

    2013-03-01

    The defects of semiconductor wafer may be generated from the manufacturing processes. A novel defect inspection method of semiconductor wafer is presented in this paper. The method is based on magneto-optic imaging, which involves inducing eddy current into the wafer under test, and detecting the magnetic flux associated with eddy current distribution in the wafer by exploiting the Faraday rotation effect. The magneto-optic image being generated may contain some noises that degrade the overall image quality, therefore, in this paper, in order to remove the unwanted noise present in the magneto-optic image, the image enhancement approach using multi-scale wavelet is presented, and the image segmentation approach based on the integration of watershed algorithm and clustering strategy is given. The experimental results show that many types of defects in wafer such as hole and scratch etc. can be detected by the method proposed in this paper.

  14. Analytical research using synchrotron radiation based techniques

    International Nuclear Information System (INIS)

    Jha, Shambhu Nath

    2015-01-01

    There are many Synchrotron Radiation (SR) based techniques such as X-ray Absorption Spectroscopy (XAS), X-ray Fluorescence Analysis (XRF), SR-Fourier-transform Infrared (SRFTIR), Hard X-ray Photoelectron Spectroscopy (HAXPS) etc. which are increasingly being employed worldwide in analytical research. With advent of modern synchrotron sources these analytical techniques have been further revitalized and paved ways for new techniques such as microprobe XRF and XAS, FTIR microscopy, Hard X-ray Photoelectron Spectroscopy (HAXPS) etc. The talk will cover mainly two techniques illustrating its capability in analytical research namely XRF and XAS. XRF spectroscopy: XRF spectroscopy is an analytical technique which involves the detection of emitted characteristic X-rays following excitation of the elements within the sample. While electron, particle (protons or alpha particles), or X-ray beams can be employed as the exciting source for this analysis, the use of X-ray beams from a synchrotron source has been instrumental in the advancement of the technique in the area of microprobe XRF imaging and trace level compositional characterisation of any sample. Synchrotron radiation induced X-ray emission spectroscopy, has become competitive with the earlier microprobe and nanoprobe techniques following the advancements in manipulating and detecting these X-rays. There are two important features that contribute to the superb elemental sensitivities of microprobe SR induced XRF: (i) the absence of the continuum (Bremsstrahlung) background radiation that is a feature of spectra obtained from charged particle beams, and (ii) the increased X-ray flux on the sample associated with the use of tunable third generation synchrotron facilities. Detection sensitivities have been reported in the ppb range, with values of 10 -17 g - 10 -14 g (depending on the particular element and matrix). Keeping in mind its demand, a microprobe XRF beamline has been setup by RRCAT at Indus-2 synchrotron

  15. Rapid simulation of X-ray transmission imaging for baggage inspection via GPU-based ray-tracing

    Science.gov (United States)

    Gong, Qian; Stoian, Razvan-Ionut; Coccarelli, David S.; Greenberg, Joel A.; Vera, Esteban; Gehm, Michael E.

    2018-01-01

    We present a pipeline that rapidly simulates X-ray transmission imaging for arbitrary system architectures using GPU-based ray-tracing techniques. The purpose of the pipeline is to enable statistical analysis of threat detection in the context of airline baggage inspection. As a faster alternative to Monte Carlo methods, we adopt a deterministic approach for simulating photoelectric absorption-based imaging. The highly-optimized NVIDIA OptiX API is used to implement ray-tracing, greatly speeding code execution. In addition, we implement the first hierarchical representation structure to determine the interaction path length of rays traversing heterogeneous media described by layered polygons. The accuracy of the pipeline has been validated by comparing simulated data with experimental data collected using a heterogenous phantom and a laboratory X-ray imaging system. On a single computer, our approach allows us to generate over 400 2D transmission projections (125 × 125 pixels per frame) per hour for a bag packed with hundreds of everyday objects. By implementing our approach on cloud-based GPU computing platforms, we find that the same 2D projections of approximately 3.9 million bags can be obtained in a single day using 400 GPU instances, at a cost of only 0.001 per bag.

  16. Ultrasonic inspection of the Calder Hall and Chaplecross reactor pressure vessels

    International Nuclear Information System (INIS)

    Pennick, A.M.

    1993-01-01

    This paper describes the ultrasonic inspection surveys that have recently been carried out on the Calder Hall and Chapelcross Magnox steel reactor pressure vessels. The development of the inspection system, which is based on the Rediman manipulator and uses the Sonomatic Zipscan equipment and Time-of-Flight diffraction techniques is discussed. The inspection results are presented and compared with the original inspection findings and limiting crack sizes. (author)

  17. High Pressure Coolant Injection system risk-based inspection guide for Hatch Nuclear Power Station

    International Nuclear Information System (INIS)

    DiBiasio, A.M.

    1993-05-01

    A review of the operating experience for the High Pressure Coolant Injection (HPCI) system at the Hatch Nuclear Power Station, Units 1 and 2, is described in this report. The information for this review was obtained from Hatch Licensee Event Reports (LERs) that were generated between 1980 and 1992. These LERs have been categorized into 23 failure modes that have been prioritized based on probabilistic risk assessment considerations. In addition, the results of the Hatch operating experience review have been compared with the results of a similar, industry wide operating, experience review. This comparison provides an indication of areas in the Hatch HPCI system that should be given increased attention in the prioritization of inspection resources

  18. Wavelet based edge detection algorithm for web surface inspection of coated board web

    Energy Technology Data Exchange (ETDEWEB)

    Barjaktarovic, M; Petricevic, S, E-mail: slobodan@etf.bg.ac.r [School of Electrical Engineering, Bulevar Kralja Aleksandra 73, 11000 Belgrade (Serbia)

    2010-07-15

    This paper presents significant improvement of the already installed vision system. System was designed for real time coated board inspection. The improvement is achieved with development of a new algorithm for edge detection. The algorithm is based on the redundant (undecimated) wavelet transform. Compared to the existing algorithm better delineation of edges is achieved. This yields to better defect detection probability and more accurate geometrical classification, which will provide additional reduction of waste. Also, algorithm will provide detailed classification and more reliably tracking of defects. This improvement requires minimal changes in processing hardware, only a replacement of the graphic card would be needed, adding only negligibly to the system cost. Other changes are accomplished entirely in the image processing software.

  19. System for inspection and quality assurance of software - A knowledge-based experiment with code understanding

    International Nuclear Information System (INIS)

    Das, B.K.

    1989-01-01

    This paper describes a knowledge-based prototype that inspects and quality-assures software components. The prototype model, which offers a singular representation of these components, is used to automate both the mechanical and nonmechanical activities in the quality assurance (QA) process. It is shown that the prototype, in addition to automating the QA process, provides a novel approach to understanding code. These approaches are compared with recent approaches to code understanding. The paper also presents the results of an experiment with several classes of nonsyntactic bugs. It is argued that a structured environment, as facilitated by this unique architecture, along with software development standards used in the QA process, is essential for meaningful analysis of code. 8 refs

  20. Simulation of Specular Surface Imaging Based on Computer Graphics: Application on a Vision Inspection System

    Directory of Open Access Journals (Sweden)

    Seulin Ralph

    2002-01-01

    Full Text Available This work aims at detecting surface defects on reflecting industrial parts. A machine vision system, performing the detection of geometric aspect surface defects, is completely described. The revealing of defects is realized by a particular lighting device. It has been carefully designed to ensure the imaging of defects. The lighting system simplifies a lot the image processing for defect segmentation and so a real-time inspection of reflective products is possible. To bring help in the conception of imaging conditions, a complete simulation is proposed. The simulation, based on computer graphics, enables the rendering of realistic images. Simulation provides here a very efficient way to perform tests compared to the numerous attempts of manual experiments.

  1. New Method to Identify Field Joint Coating Failures Based on MFL In-Line Inspection Signals

    Directory of Open Access Journals (Sweden)

    Lianshuang Dai

    2018-02-01

    Full Text Available Above ground indirect detections and random excavations that have applied the past years for buried long distance oil and gas pipelines can only identify some damaged coating locations. Hence, large number of field joint coating (FJC failures happen unconsciously until they lead to failures of the pipelines. Based on the analysis of magnetic flux leakage (MFL in-line inspection (ILI signals, combined with the statistical results of 414 excavations from two different pipeline sections, a new method to identify the failed FJC is established. Though it can only identify FJC failures when there are signs of corrosion on pipe body, it is much more efficient and cost-saving. The concluded identification rule still needs more validations and improvements to be more applicable and accuracy.

  2. Condition-based inspection/replacement policies for non-monotone deteriorating systems with environmental covariates

    Energy Technology Data Exchange (ETDEWEB)

    Zhao Xuejing [Universite de Technologie de Troyes, Institut Charles Delaunay and STMR UMR CNRS 6279, 12 rue Marie Curie, 10010 Troyes (France); School of mathematics and statistics, Lanzhou University, Lanzhou 730000 (China); Fouladirad, Mitra, E-mail: mitra.fouladirad@utt.f [Universite de Technologie de Troyes, Institut Charles Delaunay and STMR UMR CNRS 6279, 12 rue Marie Curie, 10010 Troyes (France); Berenguer, Christophe [Universite de Technologie de Troyes, Institut Charles Delaunay and STMR UMR CNRS 6279, 12 rue Marie Curie, 10010 Troyes (France); Bordes, Laurent [Universite de Pau et des Pays de l' Adour, LMA UMR CNRS 5142, 64013 PAU Cedex (France)

    2010-08-15

    The aim of this paper is to discuss the problem of modelling and optimising condition-based maintenance policies for a deteriorating system in presence of covariates. The deterioration is modelled by a non-monotone stochastic process. The covariates process is assumed to be a time-homogenous Markov chain with finite state space. A model similar to the proportional hazards model is used to show the influence of covariates on the deterioration. In the framework of the system under consideration, an appropriate inspection/replacement policy which minimises the expected average maintenance cost is derived. The average cost under different conditions of covariates and different maintenance policies is analysed through simulation experiments to compare the policies performances.

  3. Condition-based inspection/replacement policies for non-monotone deteriorating systems with environmental covariates

    International Nuclear Information System (INIS)

    Zhao Xuejing; Fouladirad, Mitra; Berenguer, Christophe; Bordes, Laurent

    2010-01-01

    The aim of this paper is to discuss the problem of modelling and optimising condition-based maintenance policies for a deteriorating system in presence of covariates. The deterioration is modelled by a non-monotone stochastic process. The covariates process is assumed to be a time-homogenous Markov chain with finite state space. A model similar to the proportional hazards model is used to show the influence of covariates on the deterioration. In the framework of the system under consideration, an appropriate inspection/replacement policy which minimises the expected average maintenance cost is derived. The average cost under different conditions of covariates and different maintenance policies is analysed through simulation experiments to compare the policies performances.

  4. 24 CFR 35.1320 - Lead-based paint inspections, paint testing, risk assessments, lead-hazard screens, and...

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 1 2010-04-01 2010-04-01 false Lead-based paint inspections, paint testing, risk assessments, lead-hazard screens, and reevaluations. 35.1320 Section 35.1320 Housing and Urban Development Office of the Secretary, Department of Housing and Urban Development LEAD-BASED PAINT...

  5. Application of the perspective-based reading technique in the nuclear I and C context. CORSICA work report 2011

    Energy Technology Data Exchange (ETDEWEB)

    Lahtinen, J.

    2012-07-01

    Inspections and reviews are one of the most effective ways of detecting errors in software development. The methods are also cost-effective because defects can be spotted early in the development, and thus the cost of repairing the defects is lower. Reading techniques are the procedures that are used in the inspection or review of a software artefact. The most common procedures are simple ad-hoc reading and a checklist- based reading technique. However, more advanced and detailed procedures have been created for various purposes. This report reviews the state-of-the-art software reading techniques used in inspections and reviews, and briefly reviews some of the empirical research in this context. The majority of the empirical research results indicate that, for example, perspective-based reading is more cost-effective and can detect more defects than more basic reading techniques. This report also describes how perspective-based reading can be applied to the inspection of nuclear-domain requirement specifications. For this purpose, seven perspective-based reading scenarios have been created. (orig.)

  6. Graph based techniques for tag cloud generation

    DEFF Research Database (Denmark)

    Leginus, Martin; Dolog, Peter; Lage, Ricardo Gomes

    2013-01-01

    Tag cloud is one of the navigation aids for exploring documents. Tag cloud also link documents through the user defined terms. We explore various graph based techniques to improve the tag cloud generation. Moreover, we introduce relevance measures based on underlying data such as ratings...... or citation counts for improved measurement of relevance of tag clouds. We show, that on the given data sets, our approach outperforms the state of the art baseline methods with respect to such relevance by 41 % on Movielens dataset and by 11 % on Bibsonomy data set....

  7. Computational framework for risk-based planning of inspections, maintenance, and condition monitoring using discrete Bayesian networks

    DEFF Research Database (Denmark)

    Nielsen, Jannie Sønderkær; Sørensen, John Dalsgaard

    2018-01-01

    This paper presents a computational framework for risk-based planning of inspections and repairs for deteriorating components. Two distinct types of decision rules are used to model decisions: simple decision rules that depend on constants or observed variables (e.g. inspection outcome...... expecte d life-cycle costs. For advanced decision rules, simulations are performed to estimate the expected costs, and dBNs are used within the simulations for decision-making. Information from inspections and condition monitoring are included if available. An example in the paper demonstrates...... the framework and the implemented strategies and decision rules, including various types of condition-based maintenance. The strategies using advanced decision rules lead to reduced costs compared to the simple decision rules when condition monitoring is applied, and the value of condition monitoring...

  8. Development of ultrasonic testing technique with the large transducer to inspect the containment vessel plates of nuclear power plant embedded in concrete

    International Nuclear Information System (INIS)

    Ishida, Hitoshi; Kurozumi, Yasuo; Kaneshima, Yoshiari

    2004-01-01

    The containment vessel plates embedded in concrete on Pressurized Water Reactors are inaccessible to inspect directly. Therefore, it is advisable to prepare inspection technology to detect existence and a location of corrosion on the embedded plates indirectly. In order to establish ultrasonic testing technique to be able to inspect the containment vessel plates embedded in concrete widely at the accessible point, experiments to detect artificial hollows simulating corrosion on a surface of a carbon steel plate mock-up covered with concrete simulating the embedded containment vessel plates were carried out with newly made ultrasonic transducers. We made newly low frequency (0.3 MHz and 0.5 MHz) surface shear horizontal (SH) wave transducers combined with three large active elements, which were equivalent to a 120mm width element. As a result of the experiments, the surface SH transducers could detect clearly the echo from the hollows with a depth of 9.5 mm and 19 mm at a distance of 1500mm from the transducers on the surface of the mock-up covered with concrete. Therefore, we evaluate that it is possible to detect the defects such as corrosion on the plates embedded in concrete with the newly made low frequency surface SH transducers with large elements. (author)

  9. Inspection Strategies for Concrete Bridges

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Thoft-Christensen, Palle

    1989-01-01

    In this paper an optimal inspection strategy for concrete bridges based on periodic routine and detailed inspections is presented. The failure mode considered is corrosion of the reinforcement due to chlorides. A simple modelling of the corrosion and of the inspection strategy is presented....... The optimal inspection strategy is determined from an optimization problem, where the design variables are time intervals between detailed inspections and the concrete cover. The strategy is illustrated on a simple structure, namely a reinforced concrete beam....

  10. A Vision-Based Self-Calibration Method for Robotic Visual Inspection Systems

    Science.gov (United States)

    Yin, Shibin; Ren, Yongjie; Zhu, Jigui; Yang, Shourui; Ye, Shenghua

    2013-01-01

    A vision-based robot self-calibration method is proposed in this paper to evaluate the kinematic parameter errors of a robot using a visual sensor mounted on its end-effector. This approach could be performed in the industrial field without external, expensive apparatus or an elaborate setup. A robot Tool Center Point (TCP) is defined in the structural model of a line-structured laser sensor, and aligned to a reference point fixed in the robot workspace. A mathematical model is established to formulate the misalignment errors with kinematic parameter errors and TCP position errors. Based on the fixed point constraints, the kinematic parameter errors and TCP position errors are identified with an iterative algorithm. Compared to the conventional methods, this proposed method eliminates the need for a robot-based-frame and hand-to-eye calibrations, shortens the error propagation chain, and makes the calibration process more accurate and convenient. A validation experiment is performed on an ABB IRB2400 robot. An optimal configuration on the number and distribution of fixed points in the robot workspace is obtained based on the experimental results. Comparative experiments reveal that there is a significant improvement of the measuring accuracy of the robotic visual inspection system. PMID:24300597

  11. A PCA and ELM Based Adaptive Method for Channel Equalization in MFL Inspection

    Directory of Open Access Journals (Sweden)

    Zhenning Wu

    2014-01-01

    Full Text Available Magnetic flux leakage (MFL as an efficient method for pipeline flaw detection plays important role in pipeline safety. This nondestructive test technique assesses the health of the buried pipeline. The signal is gathered by an array of hall-effect sensors disposed at the magnetic neutral plane of a pair of permanent magnet in the pipeline inspection gauge (PIG clinging to the inner surface of the pipe wall. The magnetic flux measured by the sensors reflects the health condition of the pipe. The signal is influenced by not only the condition of the pipe, but also by the lift-off value of the sensors and various properties of electronic component. The consistency of the position of the sensors is almost never satisfied and each sensor measures differently. In this paper, a new scheme of channel equalization is proposed for MFL signal in order to correct sensor misalignments, which eventually improves accuracy of defect characterization. The algorithm proposed in this paper is adaptive to the effects of error on the disposition of the sensor due to manufacturing imperfections and movements of the sensors. The algorithm is tested by data acquired from an experimental pipeline. The results show the effectiveness of the proposed algorithm.

  12. Analysis of risk of nonconformities and applied quality inspection methods in the process of aluminium profiles coating based on FMEA results

    OpenAIRE

    Krzysztof Knop

    2017-01-01

    The article presents the results of risk analysis associated with nonconformities of aluminium profiles in the process of coating and quality inspection methods used to their detection. Analysis of risk was done based on results of FMEA method. Evaluated quality inspection methods were distinguished based on the term of inspection in the ISO 9000:2005 norm. Manufacturing process of aluminium profile in micro-technological approach was presented. Triple quantification of nonconformities risk b...

  13. Vision-Based Corrosion Detection Assisted by a Micro-Aerial Vehicle in a Vessel Inspection Application

    Directory of Open Access Journals (Sweden)

    Alberto Ortiz

    2016-12-01

    Full Text Available Vessel maintenance requires periodic visual inspection of the hull in order to detect typical defective situations of steel structures such as, among others, coating breakdown and corrosion. These inspections are typically performed by well-trained surveyors at great cost because of the need for providing access means (e.g., scaffolding and/or cherry pickers that allow the inspector to be at arm’s reach from the structure under inspection. This paper describes a defect detection approach comprising a micro-aerial vehicle which is used to collect images from the surfaces under inspection, particularly focusing on remote areas where the surveyor has no visual access, and a coating breakdown/corrosion detector based on a three-layer feed-forward artificial neural network. As it is discussed in the paper, the success of the inspection process depends not only on the defect detection software but also on a number of assistance functions provided by the control architecture of the aerial platform, whose aim is to improve picture quality. Both aspects of the work are described along the different sections of the paper, as well as the classification performance attained.

  14. Comparison of a magnetostrictive and an EMAT guided wave technique for the long-range pipe inspection

    International Nuclear Information System (INIS)

    Jung Yong Moo; Kim, Sang Soo; Kim, Young Suk

    2005-01-01

    An EMAT sensor and a magnetostrictive sensor were developed for the long-range guided wave inspection of pipe. An array of EMAT were designed and fabricated for the generation and reception of torsional guided waves. Also a magnetostrictive sensor with a circumferentially magnetized Ni strip and coil for alternating magnetization were fabricated for torsional guided waves, T(0,1) mode. These two approaches were applied to the feeder pipe with various artificial notches. The advantages and limitations of the EMAT method and magnetostrictive method compared in the viewpoint of field application.

  15. Inspection qualification and implementation of ENIQ in Sweden

    International Nuclear Information System (INIS)

    Zettervall, Tommy

    2013-01-01

    Many countries are currently considering their approaches to inspection qualification and risk-informed in-service inspection (RI-ISI) and are carefully assessing experience data. In Europe most of the utilities operating nuclear power plants have joined together to form the European Network for Inspection Qualification ENIQ. In practice, qualification can be performed with varying degrees of complexity and cost, varying from capability statement based on existing evidence, through to an extensive qualification consisting of a detailed Technical Justification (TJ) together with open and blind trials on full-scale test blocks. An Inspection Qualification is an investigation and demonstration, which confirm that an inspection system has the ability to solve its specific tasks. The qualification is a Quality Assurance of an inspection system based on documents and practical trials. A reliable inspection system, based on a reliable qualification and correct prerequisites, will reduce total costs for Licensees and increase the credibility of the inspection result. To get such inspection system, which could be valid for many years, it's of necessity to fulfil all included parts in the process. It begins with the Technical Specification from Licensee, where input data and requirements about the actual component are specified. To get an inspection system that could live over time, the Technical Justification is of importance. Finally the test blocks and used simulation techniques play an important part of the final result, and these test blocks together with TJ form the basis for qualification body's decision. (author)

  16. Evaluating the Usefulness and the Ease of Use of a Web-based Inspection Data Collection Tool

    OpenAIRE

    Dreyer, H.M.; Laitenberger, O.

    1998-01-01

    This paper contributes a valid and reliable measurement instrument in the form of a questionnaire to determine, from a userüs perspective, the usefulness and ease of use of a Web-based Inspection Process Support tool (WIPS) that we developed for inspection data collection. The questionnaire is built upon the work of Fred Davis on perceived usefulness, ease of use, and usage of information technology. To validate the questionnaire and its underlying model as well as to evaluate WIPS, we perfor...

  17. Inspection Database

    Data.gov (United States)

    U.S. Department of Health & Human Services — FDA is disclosing the final inspection classification for inspections related to currently marketed FDA-regulated products. The disclosure of this information is not...

  18. A condition-based maintenance policy with non-periodic inspections for a two-unit series system

    International Nuclear Information System (INIS)

    Castanier, B.; Grall, A.; Berenguer, C.

    2005-01-01

    This paper considers a condition-based maintenance policy for a two-unit deteriorating system. Each unit is subject to gradual deterioration and is monitored by sequential non-periodic inspections. It can be maintained by good as new preventive or corrective replacements. Every inspection or replacement entails a set-up cost and a component-specific unit cost but if actions on the two components are combined, the set-up cost is charged only once. A parametric maintenance decision framework is proposed to coordinate inspection/replacement of the two components and minimize the long-run maintenance cost of the system. A stochastic model is developed on the basis of the semi-regenerative properties of the maintained system state and the associated cost model is used to assess and optimize the performance of the maintenance model. Numerical experiments emphasize the interest of a control of the operation groupings

  19. Modeling and optimizing periodically inspected software rejuvenation policy based on geometric sequences

    International Nuclear Information System (INIS)

    Meng, Haining; Liu, Jianjun; Hei, Xinhong

    2015-01-01

    Software aging is characterized by an increasing failure rate, progressive performance degradation and even a sudden crash in a long-running software system. Software rejuvenation is an effective method to counteract software aging. A periodically inspected rejuvenation policy for software systems is studied. The consecutive inspection intervals are assumed to be a decreasing geometric sequence, and upon the inspection times of software system and its failure features, software rejuvenation or system recovery is performed. The system availability function and cost rate function are obtained, and the optimal inspection time and rejuvenation interval are both derived to maximize system availability and minimize cost rate. Then, boundary conditions of the optimal rejuvenation policy are deduced. Finally, the numeric experiment result shows the effectiveness of the proposed policy. Further compared with the existing software rejuvenation policy, the new policy has higher system availability. - Highlights: • A periodically inspected rejuvenation policy for software systems is studied. • A decreasing geometric sequence is used to denote the consecutive inspection intervals. • The optimal inspection times and rejuvenation interval are found. • The new policy is capable of reducing average cost and improving system availability

  20. Optical profilometer using laser based conical triangulation for inspection of inner geometry of corroded pipes in cylindrical coordinates

    Science.gov (United States)

    Buschinelli, Pedro D. V.; Melo, João. Ricardo C.; Albertazzi, Armando; Santos, João. M. C.; Camerini, Claudio S.

    2013-04-01

    An axis-symmetrical optical laser triangulation system was developed by the authors to measure the inner geometry of long pipes used in the oil industry. It has a special optical configuration able to acquire shape information of the inner geometry of a section of a pipe from a single image frame. A collimated laser beam is pointed to the tip of a 45° conical mirror. The laser light is reflected in such a way that a radial light sheet is formed and intercepts the inner geometry and forms a bright laser line on a section of the inspected pipe. A camera acquires the image of the laser line through a wide angle lens. An odometer-based triggering system is used to shot the camera to acquire a set of equally spaced images at high speed while the device is moved along the pipe's axis. Image processing is done in real-time (between images acquisitions) thanks to the use of parallel computing technology. The measured geometry is analyzed to identify corrosion damages. The measured geometry and results are graphically presented using virtual reality techniques and devices as 3D glasses and head-mounted displays. The paper describes the measurement principles, calibration strategies, laboratory evaluation of the developed device, as well as, a practical example of a corroded pipe used in an industrial gas production plant.

  1. Artificial Intelligence based technique for BTS placement

    Science.gov (United States)

    Alenoghena, C. O.; Emagbetere, J. O.; Aibinu, A. M.

    2013-12-01

    The increase of the base transceiver station (BTS) in most urban areas can be traced to the drive by network providers to meet demand for coverage and capacity. In traditional network planning, the final decision of BTS placement is taken by a team of radio planners, this decision is not fool proof against regulatory requirements. In this paper, an intelligent based algorithm for optimal BTS site placement has been proposed. The proposed technique takes into consideration neighbour and regulation considerations objectively while determining cell site. The application will lead to a quantitatively unbiased evaluated decision making process in BTS placement. An experimental data of a 2km by 3km territory was simulated for testing the new algorithm, results obtained show a 100% performance of the neighbour constrained algorithm in BTS placement optimization. Results on the application of GA with neighbourhood constraint indicate that the choices of location can be unbiased and optimization of facility placement for network design can be carried out.

  2. Artificial Intelligence based technique for BTS placement

    International Nuclear Information System (INIS)

    Alenoghena, C O; Emagbetere, J O; 1 Minna (Nigeria))" data-affiliation=" (Department of Telecommunications Engineering, Federal University of Techn.1 Minna (Nigeria))" >Aibinu, A M

    2013-01-01

    The increase of the base transceiver station (BTS) in most urban areas can be traced to the drive by network providers to meet demand for coverage and capacity. In traditional network planning, the final decision of BTS placement is taken by a team of radio planners, this decision is not fool proof against regulatory requirements. In this paper, an intelligent based algorithm for optimal BTS site placement has been proposed. The proposed technique takes into consideration neighbour and regulation considerations objectively while determining cell site. The application will lead to a quantitatively unbiased evaluated decision making process in BTS placement. An experimental data of a 2km by 3km territory was simulated for testing the new algorithm, results obtained show a 100% performance of the neighbour constrained algorithm in BTS placement optimization. Results on the application of GA with neighbourhood constraint indicate that the choices of location can be unbiased and optimization of facility placement for network design can be carried out

  3. To develop a flying fish egg inspection system by a digital imaging base system

    Science.gov (United States)

    Chen, Chun-Jen; Jywe, Wenyuh; Hsieh, Tung-Hsien; Chen, Chien Hung

    2015-07-01

    This paper develops an automatic optical inspection system for flying fish egg quality inspection. The automatic optical inspection system consists of a 2-axes stage, a digital camera, a lens, a LED light source, a vacuum generator, a tube and a tray. This system can automatically find the particle on the flying egg tray and used stage to driver the tube onto the particle. Then use straw and vacuum generator to pick up the particle. The system pick rate is about 30 particles per minute.

  4. Application of CFD dispersion calculation in risk based inspection for release of H2S

    International Nuclear Information System (INIS)

    Sharma, Pavan K.; Vinod, Gopika; Singh, R.K.; Rao, V.V.S.S.; Vaze, K.K.

    2011-01-01

    In atmospheric dispersion both deterministic and probabilistic approached have been used for addressing design and regulatory concerns. In context of deterministic calculations the amount of pollutants dispersion in the atmosphere is an important area wherein different approaches are followed in development of good analytical model. The analysis based on Computational Fluid Dynamics (CFD) codes offer an opportunity of model development based on first principles of physics and hence such models have an edge over the existing models. In context of probabilistic methods applying risk based inspection (wherein consequence of failure from each component needs to be assessed) are becoming popular. Consequence evaluation in a process plant is a crucial task. Often the number of components considered for life management will be too huge. Also consequence evaluation of all the components proved to be laborious task. The present paper is the results of joint collaborative work from deterministic and probabilistic modelling group working in the field of atmospheric dispersion. Even though API 581 has simplified qualitative approach, regulators find the some of the factors, in particular, quantity factor, not suitable for process plants. Often dispersion calculations for heavy gas are done with very simple model which can not take care of density based atmospheric dispersion. This necessitates a new approach with a CFD based technical basis is proposed, so that the range of quantity considered along with factors used can be justified. The present paper is aimed at bringing out some of the distinct merits and demerits of the CFD based models. A brief account of the applications of such CFD codes reported in literature is also presented in the paper. This paper describes the approach devised and demonstrated for the said issue with emphasis of CFD calculations. (author)

  5. Risk analysis of heat recovery steam generator with semi quantitative risk based inspection API 581

    Science.gov (United States)

    Prayogo, Galang Sandy; Haryadi, Gunawan Dwi; Ismail, Rifky; Kim, Seon Jin

    2016-04-01

    Corrosion is a major problem that most often occurs in the power plant. Heat recovery steam generator (HRSG) is an equipment that has a high risk to the power plant. The impact of corrosion damage causing HRSG power plant stops operating. Furthermore, it could be threaten the safety of employees. The Risk Based Inspection (RBI) guidelines by the American Petroleum Institute (API) 58 has been used to risk analysis in the HRSG 1. By using this methodology, the risk that caused by unexpected failure as a function of the probability and consequence of failure can be estimated. This paper presented a case study relating to the risk analysis in the HRSG, starting with a summary of the basic principles and procedures of risk assessment and applying corrosion RBI for process industries. The risk level of each HRSG equipment were analyzed: HP superheater has a medium high risk (4C), HP evaporator has a medium-high risk (4C), and the HP economizer has a medium risk (3C). The results of the risk assessment using semi-quantitative method of standard API 581 based on the existing equipment at medium risk. In the fact, there is no critical problem in the equipment components. Damage mechanisms were prominent throughout the equipment is thinning mechanism. The evaluation of the risk approach was done with the aim of reducing risk by optimizing the risk assessment activities.

  6. Surface inspection system for industrial components based on shape from shading minimization approach

    Science.gov (United States)

    Kotan, Muhammed; Öz, Cemil

    2017-12-01

    An inspection system using estimated three-dimensional (3-D) surface characteristics information to detect and classify the faults to increase the quality control on the frequently used industrial components is proposed. Shape from shading (SFS) is one of the basic and classic 3-D shape recovery problems in computer vision. In our application, we developed a system using Frankot and Chellappa SFS method based on the minimization of the selected basis function. First, the specialized image acquisition system captured the images of the component. To eliminate noise, wavelet transform is applied to the taken images. Then, estimated gradients were used to obtain depth and surface profiles. Depth information was used to determine and classify the surface defects. Also, a comparison made with some linearization-based SFS algorithms was discussed. The developed system was applied to real products and the results indicated that using SFS approaches is useful and various types of defects can easily be detected in a short period of time.

  7. Automated Signal Processing Applied to Volatile-Based Inspection of Greenhouse Crops

    Science.gov (United States)

    Jansen, Roel; Hofstee, Jan Willem; Bouwmeester, Harro; van Henten, Eldert

    2010-01-01

    Gas chromatograph–mass spectrometers (GC-MS) have been used and shown utility for volatile-based inspection of greenhouse crops. However, a widely recognized difficulty associated with GC-MS application is the large and complex data generated by this instrument. As a consequence, experienced analysts are often required to process this data in order to determine the concentrations of the volatile organic compounds (VOCs) of interest. Manual processing is time-consuming, labour intensive and may be subject to errors due to fatigue. The objective of this study was to assess whether or not GC-MS data can also be automatically processed in order to determine the concentrations of crop health associated VOCs in a greenhouse. An experimental dataset that consisted of twelve data files was processed both manually and automatically to address this question. Manual processing was based on simple peak integration while the automatic processing relied on the algorithms implemented in the MetAlign™ software package. The results of automatic processing of the experimental dataset resulted in concentrations similar to that after manual processing. These results demonstrate that GC-MS data can be automatically processed in order to accurately determine the concentrations of crop health associated VOCs in a greenhouse. When processing GC-MS data automatically, noise reduction, alignment, baseline correction and normalisation are required. PMID:22163594

  8. Risk analysis of heat recovery steam generator with semi quantitative risk based inspection API 581

    International Nuclear Information System (INIS)

    Prayogo, Galang Sandy; Haryadi, Gunawan Dwi; Ismail, Rifky; Kim, Seon Jin

    2016-01-01

    Corrosion is a major problem that most often occurs in the power plant. Heat recovery steam generator (HRSG) is an equipment that has a high risk to the power plant. The impact of corrosion damage causing HRSG power plant stops operating. Furthermore, it could be threaten the safety of employees. The Risk Based Inspection (RBI) guidelines by the American Petroleum Institute (API) 58 has been used to risk analysis in the HRSG 1. By using this methodology, the risk that caused by unexpected failure as a function of the probability and consequence of failure can be estimated. This paper presented a case study relating to the risk analysis in the HRSG, starting with a summary of the basic principles and procedures of risk assessment and applying corrosion RBI for process industries. The risk level of each HRSG equipment were analyzed: HP superheater has a medium high risk (4C), HP evaporator has a medium-high risk (4C), and the HP economizer has a medium risk (3C). The results of the risk assessment using semi-quantitative method of standard API 581 based on the existing equipment at medium risk. In the fact, there is no critical problem in the equipment components. Damage mechanisms were prominent throughout the equipment is thinning mechanism. The evaluation of the risk approach was done with the aim of reducing risk by optimizing the risk assessment activities.

  9. Risk analysis of heat recovery steam generator with semi quantitative risk based inspection API 581

    Energy Technology Data Exchange (ETDEWEB)

    Prayogo, Galang Sandy, E-mail: gasandylang@live.com; Haryadi, Gunawan Dwi; Ismail, Rifky [Department of Mechanical Engineering, Diponegoro University, Semarang (Indonesia); Kim, Seon Jin [Department of Mechanical & Automotive Engineering of Pukyong National University (Korea, Republic of)

    2016-04-19

    Corrosion is a major problem that most often occurs in the power plant. Heat recovery steam generator (HRSG) is an equipment that has a high risk to the power plant. The impact of corrosion damage causing HRSG power plant stops operating. Furthermore, it could be threaten the safety of employees. The Risk Based Inspection (RBI) guidelines by the American Petroleum Institute (API) 58 has been used to risk analysis in the HRSG 1. By using this methodology, the risk that caused by unexpected failure as a function of the probability and consequence of failure can be estimated. This paper presented a case study relating to the risk analysis in the HRSG, starting with a summary of the basic principles and procedures of risk assessment and applying corrosion RBI for process industries. The risk level of each HRSG equipment were analyzed: HP superheater has a medium high risk (4C), HP evaporator has a medium-high risk (4C), and the HP economizer has a medium risk (3C). The results of the risk assessment using semi-quantitative method of standard API 581 based on the existing equipment at medium risk. In the fact, there is no critical problem in the equipment components. Damage mechanisms were prominent throughout the equipment is thinning mechanism. The evaluation of the risk approach was done with the aim of reducing risk by optimizing the risk assessment activities.

  10. Qualification of NDT techniques for in-service inspections in nuclear power plants in accordance with ENIQ - examples and lessons - learned

    International Nuclear Information System (INIS)

    Just, T.; Csapo, G.

    2006-01-01

    ENIQ (European Network for Inspection and Qualification) has developed regulations on how to qualify non-destructive testing (NDT) methods and techniques in a standardized and structured manner. Two major innovative qualifications were carried out and reviewed with regard to implementation, according to the recommended German practice of ENIQ. The conclusions were drawn after performing the ENIQ qualification procedure for in-service inspections (ISI) of real components in nuclear power plants (NPP). The first example covers the qualification of NDT methods for the detection and characterization of surface, subsurface and underclad cracks in the area of the austenitic cladded RPV surface. Open and blind tests were conducted applying UT and ET (from the ID) and UT (from the OD) on realistic flaws (artificially induced IGSCC, hot cracks and fatigue cracks) in the cladding of a full scale RPV mock-up from MPA Stuttgart. The second example covers the qualification of mechanised RT in combination with tomography (developed by the BAM) for the sizing of cracks in pipe welds. For both qualification procedures TUEV NORD SysTec experts were part of the qualification body. The proposed NDT procedures have been qualified within defined limits of application. Recommendations were made to optimise the procedures and the techniques itself further. (orig.)

  11. Risk-Informed Decisions Optimization in Inspection and Maintenance

    International Nuclear Information System (INIS)

    Robertas Alzbutas

    2002-01-01

    The Risk-Informed Approach (RIA) used to support decisions related to inspection and maintenance program is considered. The use of risk-informed methods can help focus the adequate in-service inspections and control on the more important locations of complex dynamic systems. The focus is set on the highest risk measured as conditional core damage frequency, which is produced by the frequencies of degradation and final failure at different locations combined with the conditional failure consequence probability. The probabilities of different degradation states per year and consequences are estimated quantitatively. The investigation of inspection and maintenance process is presented as the combination of deterministic and probabilistic analysis based on general risk-informed model, which includes the inspection and maintenance program features. Such RIA allows an optimization of inspection program while maintaining probabilistic and fundamental deterministic safety requirements. The failure statistics analysis is used as well as the evaluation of reliability of inspections. The assumptions regarding the effectiveness of the inspection methods are based on a classification of the accessibility of the welds during the inspection and on the different techniques used for inspection. The probability of defect detection is assumed to depend on the parameters either through logarithmic or logit transformation. As example the modeling of the pipe systems inspection process is analyzed. The means to reduce a number of inspection sites and the cumulative radiation exposure to the NPP inspection personnel with a reduction of overall risk is presented together with used and developed software. The developed software can perform and administrate all the risk evaluations and ensure the possibilities to compare different options and perform sensitivity analysis. The approaches to define an acceptable level of risk are discussed. These approaches with appropriate software in

  12. Automatic Quality Inspection of Percussion Cap Mass Production by Means of 3D Machine Vision and Machine Learning Techniques

    Science.gov (United States)

    Tellaeche, A.; Arana, R.; Ibarguren, A.; Martínez-Otzeta, J. M.

    The exhaustive quality control is becoming very important in the world's globalized market. One of these examples where quality control becomes critical is the percussion cap mass production. These elements must achieve a minimum tolerance deviation in their fabrication. This paper outlines a machine vision development using a 3D camera for the inspection of the whole production of percussion caps. This system presents multiple problems, such as metallic reflections in the percussion caps, high speed movement of the system and mechanical errors and irregularities in percussion cap placement. Due to these problems, it is impossible to solve the problem by traditional image processing methods, and hence, machine learning algorithms have been tested to provide a feasible classification of the possible errors present in the percussion caps.

  13. 40-Gbps optical backbone network deep packet inspection based on FPGA

    Science.gov (United States)

    Zuo, Yuan; Huang, Zhiping; Su, Shaojing

    2014-11-01

    In the era of information, the big data, which contains huge information, brings about some problems, such as high speed transmission, storage and real-time analysis and process. As the important media for data transmission, the Internet is the significant part for big data processing research. With the large-scale usage of the Internet, the data streaming of network is increasing rapidly. The speed level in the main fiber optic communication of the present has reached 40Gbps, even 100Gbps, therefore data on the optical backbone network shows some features of massive data. Generally, data services are provided via IP packets on the optical backbone network, which is constituted with SDH (Synchronous Digital Hierarchy). Hence this method that IP packets are directly mapped into SDH payload is named POS (Packet over SDH) technology. Aiming at the problems of real time process of high speed massive data, this paper designs a process system platform based on ATCA for 40Gbps POS signal data stream recognition and packet content capture, which employs the FPGA as the CPU. This platform offers pre-processing of clustering algorithms, service traffic identification and data mining for the following big data storage and analysis with high efficiency. Also, the operational procedure is proposed in this paper. Four channels of 10Gbps POS signal decomposed by the analysis module, which chooses FPGA as the kernel, are inputted to the flow classification module and the pattern matching component based on TCAM. Based on the properties of the length of payload and net flows, buffer management is added to the platform to keep the key flow information. According to data stream analysis, DPI (deep packet inspection) and flow balance distribute, the signal is transmitted to the backend machine through the giga Ethernet ports on back board. Practice shows that the proposed platform is superior to the traditional applications based on ASIC and NP.

  14. Defect inspection in hot slab surface: multi-source CCD imaging based fuzzy-rough sets method

    Science.gov (United States)

    Zhao, Liming; Zhang, Yi; Xu, Xiaodong; Xiao, Hong; Huang, Chao

    2016-09-01

    To provide an accurate surface defects inspection method and make the automation of robust image region of interests(ROI) delineation strategy a reality in production line, a multi-source CCD imaging based fuzzy-rough sets method is proposed for hot slab surface quality assessment. The applicability of the presented method and the devised system are mainly tied to the surface quality inspection for strip, billet and slab surface etcetera. In this work we take into account the complementary advantages in two common machine vision (MV) systems(line array CCD traditional scanning imaging (LS-imaging) and area array CCD laser three-dimensional (3D) scanning imaging (AL-imaging)), and through establishing the model of fuzzy-rough sets in the detection system the seeds for relative fuzzy connectedness(RFC) delineation for ROI can placed adaptively, which introduces the upper and lower approximation sets for RIO definition, and by which the boundary region can be delineated by RFC region competitive classification mechanism. For the first time, a Multi-source CCD imaging based fuzzy-rough sets strategy is attempted for CC-slab surface defects inspection that allows an automatic way of AI algorithms and powerful ROI delineation strategies to be applied to the MV inspection field.

  15. Inspection of Pipe Inner Surface using Advanced Pipe Crawler Robot with PVDF Sensor based Rotating Probe

    Directory of Open Access Journals (Sweden)

    Vimal AGARWAL

    2011-04-01

    Full Text Available Due to corrosive environment, pipes used for transportation of water and gas at the plants often get damaged. Defects caused by corrosion and cracking may cause serious accidents like leakage, fire and blasts. It also reduces the life of the transportation system substantially. In order to inspect such defects, a Polyvinyledene Fluoride (PVDF based cantilever smart probe is developed to scan the surface quality of the pipes. The smart probe, during rotation, touches the inner surface of the pipe and experience a broad-band excitation in the absence of surface features. On the other hand, whenever the probe comes across any surface projection, there is a change in vibration pattern of the probe, which causes a high voltage peak/pulse. Such peaks/pulses could give useful information about the location and nature of a defect. Experiments are carried out on different patterns, sizes and shapes of surface projections artificially constructed inside the pipe. The sensor system has reliably predicted the presence and distribution of projections in every case. It is envisaged that the new sensing system could be used effectively for pipe health monitoring.

  16. Working group 8: inspection tools

    Energy Technology Data Exchange (ETDEWEB)

    Billey, Deb; Kania, Richard; Nickle, Randy; Wang, Rick; Westwood, Stephen

    2011-07-01

    This eighth working group of the Banff 2011 conference discussed the inspection tools and techniques used by the upstream and downstream pipeline industry to evaluate pipeline integrity. Special attention was given to the challenges and successes related to in-line inspection (ILI) technology. The background of current dent assessment criteria in B31.8 was presented, including dent definition for ILI vendors and pipeline operators as well as codes (CSA Z662 and B31.8). The workshop described examples of dents and assessments showing inconsistency with current criteria as set out by TCPL and Marathon. This workshop produced a single, industry-wide definition of the dent. It was found that the strain based criteria were more practical because depth based is conservative and may miss shallow occurrences. The creation of joint industry group was proposed to develop strain based criteria for incorporation into CSAZ662 and B31.8.

  17. Accuracy improvement of the H-drive air-levitating wafer inspection stage based on error analysis and compensation

    Science.gov (United States)

    Zhang, Fan; Liu, Pinkuan

    2018-04-01

    In order to improve the inspection precision of the H-drive air-bearing stage for wafer inspection, in this paper the geometric error of the stage is analyzed and compensated. The relationship between the positioning errors and error sources are initially modeled, and seven error components are identified that are closely related to the inspection accuracy. The most effective factor that affects the geometric error is identified by error sensitivity analysis. Then, the Spearman rank correlation method is applied to find the correlation between different error components, aiming at guiding the accuracy design and error compensation of the stage. Finally, different compensation methods, including the three-error curve interpolation method, the polynomial interpolation method, the Chebyshev polynomial interpolation method, and the B-spline interpolation method, are employed within the full range of the stage, and their results are compared. Simulation and experiment show that the B-spline interpolation method based on the error model has better compensation results. In addition, the research result is valuable for promoting wafer inspection accuracy and will greatly benefit the semiconductor industry.

  18. AUTOMATED INSPECTION OF POWER LINE CORRIDORS TO MEASURE VEGETATION UNDERCUT USING UAV-BASED IMAGES

    Directory of Open Access Journals (Sweden)

    M. Maurer

    2017-08-01

    Full Text Available Power line corridor inspection is a time consuming task that is performed mostly manually. As the development of UAVs made huge progress in recent years, and photogrammetric computer vision systems became well established, it is time to further automate inspection tasks. In this paper we present an automated processing pipeline to inspect vegetation undercuts of power line corridors. For this, the area of inspection is reconstructed, geo-referenced, semantically segmented and inter class distance measurements are calculated. The presented pipeline performs an automated selection of the proper 3D reconstruction method for on the one hand wiry (power line, and on the other hand solid objects (surrounding. The automated selection is realized by performing pixel-wise semantic segmentation of the input images using a Fully Convolutional Neural Network. Due to the geo-referenced semantic 3D reconstructions a documentation of areas where maintenance work has to be performed is inherently included in the distance measurements and can be extracted easily. We evaluate the influence of the semantic segmentation according to the 3D reconstruction and show that the automated semantic separation in wiry and dense objects of the 3D reconstruction routine improves the quality of the vegetation undercut inspection. We show the generalization of the semantic segmentation to datasets acquired using different acquisition routines and to varied seasons in time.

  19. Automated Inspection of Power Line Corridors to Measure Vegetation Undercut Using Uav-Based Images

    Science.gov (United States)

    Maurer, M.; Hofer, M.; Fraundorfer, F.; Bischof, H.

    2017-08-01

    Power line corridor inspection is a time consuming task that is performed mostly manually. As the development of UAVs made huge progress in recent years, and photogrammetric computer vision systems became well established, it is time to further automate inspection tasks. In this paper we present an automated processing pipeline to inspect vegetation undercuts of power line corridors. For this, the area of inspection is reconstructed, geo-referenced, semantically segmented and inter class distance measurements are calculated. The presented pipeline performs an automated selection of the proper 3D reconstruction method for on the one hand wiry (power line), and on the other hand solid objects (surrounding). The automated selection is realized by performing pixel-wise semantic segmentation of the input images using a Fully Convolutional Neural Network. Due to the geo-referenced semantic 3D reconstructions a documentation of areas where maintenance work has to be performed is inherently included in the distance measurements and can be extracted easily. We evaluate the influence of the semantic segmentation according to the 3D reconstruction and show that the automated semantic separation in wiry and dense objects of the 3D reconstruction routine improves the quality of the vegetation undercut inspection. We show the generalization of the semantic segmentation to datasets acquired using different acquisition routines and to varied seasons in time.

  20. Modeling of a remote inspection system for NSSS components

    International Nuclear Information System (INIS)

    Choi, Yoo Rark; Kim, Jae Hee; Lee, Jae Cheol

    2003-03-01

    Safety inspection for safety-critical unit of nuclear power plant has been processed using off-line technology. Thus we can not access safety inspection system and inspection data via network such as internet. We are making an on-line control and data access system based on WWW and JAVA technologies which can be used during plant operation to overcome these problems. Users can access inspection systems and inspection data only using web-browser. This report discusses about analysis of the existing remote system and essential techniques such as Web, JAVA, client/server model, and multi-tier model. This report also discusses about a system modeling that we have been developed using these techniques and provides solutions for developing an on-line control and data access system

  1. Application of corrosion screening tools for riser inspection

    International Nuclear Information System (INIS)

    Zamir Mohamed Daud; Vijayan, S.

    2003-01-01

    As offshore facilities approach the end of their design life, owners would like to assess the condition and integrity of plant and equipment. Detailed inspection, including non-destructive testing (NDT), are implemented and results are utilised for predictive maintenance and estimating useful remaining life. Except for risk based inspection, the extent of surface coverage required would be more compared to inspection of pre-determined spots. Risers, for example, usually have several layers of coating that prevent use of conventional techniques for inspection of corrosion. Complete coverage requires access (including removal coatings and insulation). Inspection utilising the conventional NDT tools can be very slow and expensive. However, recent advances have forwarded the use of specialised NDT techniques that were developed for inspection of corrosion under insulation (CUI). This paper details two screening inspection tools, LIXI Profiler and RTD-INCOTEST that have been applied to inspection of risers. LIXI Profiler is based on attenuation of penetrating radiation by materials, and RTD-INCOTEST is based on decay of pulsed eddy current in materials. (Author)

  2. The broken food chain information: cross border issues of risk-based meat inspection in the pig sector in Germany and the Netherlands

    NARCIS (Netherlands)

    Wilke, T.; Wagenberg, van C.P.A.; Oosterkamp, E.B.; Bondt, N.; Lang, J.

    2012-01-01

    European food safety legislation allows for a new type of meat inspection in swine. This ‘risk-based meat inspection without incision’ or ‘supply chain meat inspection’ (SCMI) uses food chain information to derive a veterinary prognosis on the pigs’ health prior to delivery to the slaughterhouse and

  3. Analysis of risk of nonconformities and applied quality inspection methods in the process of aluminium profiles coating based on FMEA results

    Directory of Open Access Journals (Sweden)

    Krzysztof Knop

    2017-10-01

    Full Text Available The article presents the results of risk analysis associated with nonconformities of aluminium profiles in the process of coating and quality inspection methods used to their detection. Analysis of risk was done based on results of FMEA method. Evaluated quality inspection methods were distinguished based on the term of inspection in the ISO 9000:2005 norm. Manufacturing process of aluminium profile in micro-technological approach was presented. Triple quantification of nonconformities risk based on the FMEA method by using three different approaches was conducted. Analysis of nonconformities risks associated with the use of specific quality inspection methods was done. In the last part the analysis of causes of critical nonconformities, proposals for improvement actions reducing the risk of the critical nonconformities and applied critical quality inspection method were showed.

  4. Quantitative Inspection of Remanence of Broken Wire Rope Based on Compressed Sensing.

    Science.gov (United States)

    Zhang, Juwei; Tan, Xiaojiang

    2016-08-25

    Most traditional strong magnetic inspection equipment has disadvantages such as big excitation devices, high weight, low detection precision, and inconvenient operation. This paper presents the design of a giant magneto-resistance (GMR) sensor array collection system. The remanence signal is collected to acquire two-dimensional magnetic flux leakage (MFL) data on the surface of wire ropes. Through the use of compressed sensing wavelet filtering (CSWF), the image expression of wire ropes MFL on the surface was obtained. Then this was taken as the input of the designed back propagation (BP) neural network to extract three kinds of MFL image geometry features and seven invariant moments of defect images. Good results were obtained. The experimental results show that nondestructive inspection through the use of remanence has higher accuracy and reliability compared with traditional inspection devices, along with smaller volume, lighter weight and higher precision.

  5. Quantitative Inspection of Remanence of Broken Wire Rope Based on Compressed Sensing

    Science.gov (United States)

    Zhang, Juwei; Tan, Xiaojiang

    2016-01-01

    Most traditional strong magnetic inspection equipment has disadvantages such as big excitation devices, high weight, low detection precision, and inconvenient operation. This paper presents the design of a giant magneto-resistance (GMR) sensor array collection system. The remanence signal is collected to acquire two-dimensional magnetic flux leakage (MFL) data on the surface of wire ropes. Through the use of compressed sensing wavelet filtering (CSWF), the image expression of wire ropes MFL on the surface was obtained. Then this was taken as the input of the designed back propagation (BP) neural network to extract three kinds of MFL image geometry features and seven invariant moments of defect images. Good results were obtained. The experimental results show that nondestructive inspection through the use of remanence has higher accuracy and reliability compared with traditional inspection devices, along with smaller volume, lighter weight and higher precision. PMID:27571077

  6. ASME development of risk-based inspection guidelines for nuclear power plants

    International Nuclear Information System (INIS)

    Gore, B.F.; Balkey, K.R.

    1992-08-01

    A methodology has been developed for use in preparing guidelines for the in-service inspection of nuclear power plant pressure boundary and structural components. This methodology is a further development of a general methodology previously published by the task force for application to any industry. It is unique in that it utilizes probabilistic risk assessment (PRA) information to improve the quantification of risks associated with component ruptures. A procedure has also been recommended for using the resulting quantified risk estimates to determine target component rupture probability values to be maintained by inspection activities. Characteristics which an inspection strategy must possess in order to maintain target rupture probabilities are being determined by structural risk and reliability analysis (SRRA) calculations. The major features of this methodology are described in this paper, and example applications are briefly discussed. Plans for additional work in developing and applying the methodology are described

  7. Status of ASME risk-based inspection guidelines development for nuclear power plants

    International Nuclear Information System (INIS)

    Gore, B.F.; Vo, T.V.; Balkey, K.R.

    1991-01-01

    The general methodology published by the task force is being applied to develop guidelines for the inspection of nuclear power plant components. The methodology has been expanded to include the use of information from probabilistic risk assessments to improve the quantification of risks associated with component ruptures. In addition, a procedure has been recommended for using these quantified risk estimates to determine target component rupture probability values to be maintained by inspection activities. Finally, the method for determining the characteristics which an inspection strategy must possess in order to maintain these target rupture probabilities has been described. This paper presents the major features of this methodology, along with a discussion of the status of efforts to develop and to apply it further

  8. Quantitative Inspection of Remanence of Broken Wire Rope Based on Compressed Sensing

    Directory of Open Access Journals (Sweden)

    Juwei Zhang

    2016-08-01

    Full Text Available Most traditional strong magnetic inspection equipment has disadvantages such as big excitation devices, high weight, low detection precision, and inconvenient operation. This paper presents the design of a giant magneto-resistance (GMR sensor array collection system. The remanence signal is collected to acquire two-dimensional magnetic flux leakage (MFL data on the surface of wire ropes. Through the use of compressed sensing wavelet filtering (CSWF, the image expression of wire ropes MFL on the surface was obtained. Then this was taken as the input of the designed back propagation (BP neural network to extract three kinds of MFL image geometry features and seven invariant moments of defect images. Good results were obtained. The experimental results show that nondestructive inspection through the use of remanence has higher accuracy and reliability compared with traditional inspection devices, along with smaller volume, lighter weight and higher precision.

  9. Evaluation of effectiveness of inservice inspection in aging PWR plants based on PSA

    Energy Technology Data Exchange (ETDEWEB)

    Hanafusa, Hidemitsu; Irie, Takashi; Suyama, Takeshi [Institute of Nuclear Safety Systems Inc., Mihama, Fukui (Japan); Morota, Hidetsugu [Computer Software Development Co., Ltd., Tokyo (Japan)

    2001-09-01

    By making use of a probabilistic fracture mechanics (PFM) code which had been improved to be able to evaluate the influence of thermal aging embrittlement of cast stainless steel, we evaluated the fracture probability of welding parts of the piping of the pressurized water reactor plants in Japan and the core damage frequency by the fracture. In addition, we ranked the welding parts by the safety significance and evaluated the effectiveness of inservice inspection (ISI). As a result, it is seen that the risk increases about 25% for extending the plant life from 40 to 60 years without ISI. However, the influence of the risk on the plant life becomes negligible, when the ISI is performed adequately. This assessment is useful to plan efficient inspection and test programs of a plant under limited resources, because it is available to rank piping segments by the safety significance and to evaluate the effectiveness of inspection and test quantitatively. (author)

  10. Inspection Robot Based Mobile Sensing and Power Line Tracking for Smart Grid

    Directory of Open Access Journals (Sweden)

    Bat-erdene Byambasuren

    2016-02-01

    Full Text Available Smart sensing and power line tracking is very important in a smart grid system. Illegal electricity usage can be detected by remote current measurement on overhead power lines using an inspection robot. There is a need for accurate detection methods of illegal electricity usage. Stable and correct power line tracking is a very prominent issue. In order to correctly track and make accurate measurements, the swing path of a power line should be previously fitted and predicted by a mathematical function using an inspection robot. After this, the remote inspection robot can follow the power line and measure the current. This paper presents a new power line tracking method using parabolic and circle fitting algorithms for illegal electricity detection. We demonstrate the effectiveness of the proposed tracking method by simulation and experimental results.

  11. Inspection Robot Based Mobile Sensing and Power Line Tracking for Smart Grid.

    Science.gov (United States)

    Byambasuren, Bat-Erdene; Kim, Donghan; Oyun-Erdene, Mandakh; Bold, Chinguun; Yura, Jargalbaatar

    2016-02-19

    Smart sensing and power line tracking is very important in a smart grid system. Illegal electricity usage can be detected by remote current measurement on overhead power lines using an inspection robot. There is a need for accurate detection methods of illegal electricity usage. Stable and correct power line tracking is a very prominent issue. In order to correctly track and make accurate measurements, the swing path of a power line should be previously fitted and predicted by a mathematical function using an inspection robot. After this, the remote inspection robot can follow the power line and measure the current. This paper presents a new power line tracking method using parabolic and circle fitting algorithms for illegal electricity detection. We demonstrate the effectiveness of the proposed tracking method by simulation and experimental results.

  12. Generic safety insights for inspection of boiling water reactors

    International Nuclear Information System (INIS)

    Higgins, J.C.; Taylor, J.H.; Fresco, A.N.; Hillman, B.M.

    1987-01-01

    As the number of operating nuclear power plants (NPP) increases, safety inspection has increased in importance. However, precisely what is important, and what is not important? What should one focus inspection efforts on. Over the last two years Probabilistic Risk Assessment (PR) techniques have been developed to aid in the inspection process. Broad interest in generic PRA-based methods has arisen in the past year, since only about 25% of the US nuclear power plants have completed PRAs, and also, inspectors want PRA-based tools for these plants. This paper describes the BNL program to develop generic BWR PRA-based inspection insights or inspection guidance designed to be applied to plants without PRAs

  13. Inspection vehicle

    International Nuclear Information System (INIS)

    Takahashi, Masaki; Omote, Tatsuyuki; Yoneya, Yutaka; Tanaka, Keiji; Waki, Tetsuro; Yoshida, Tomiji; Kido, Tsuyoshi.

    1993-01-01

    An inspection vehicle comprises a small-sized battery directly connected with a power motor or a direct power source from trolly lines and a switching circuit operated by external signals. The switch judges advance or retreat by two kinds of signals and the inspection vehicle is recovered by self-running. In order to recover the abnormally stopped inspection vehicle to the targeted place, the inspection vehicle is made in a free-running state by using a clutch mechanism and is pushed by an other vehicle. (T.M.)

  14. Application of immersion phased array UT technique in nickel based alloy weld

    International Nuclear Information System (INIS)

    Hirasawa, Taiji; Nagai, Satoshi; Murakami, Koji; Yuguchi, Yasuhiro; Ootsubo, Tooru; Naruse, Katsuhiko

    2007-01-01

    The improvement of defect detection and sizing capabilities for nondestructive inspection technique has been required in order to ensure the reliable operation and life extension of nuclear power plant. Immersion phased array UT technique which is not affected the surface geometry of welds has been developed for inspection of BWR internals such as shroud, shroud support, and so on. Phased array UT technique was applied for shroud support mockup specimen with fatigue crack and partially SCC. From the experimental results, the superior performance of phased array UT for the RPV outside and inside inspection was shown. (author)

  15. MTR fuel inspection at CERCA

    International Nuclear Information System (INIS)

    Fanjas, Y.

    1992-01-01

    The stringent specifications for MTR fuel plates and fuel elements require various sophisticated inspection techniques. In particular, the development of low enriched silicide fuels made it necessary to adapt these techniques to high density plates. This paper presents the status of inspection technology at CERCA. (author)

  16. Probabilistic safety analysis and risk-based inspection of nuclear research reactors: state-of-the-art and implementation proposal

    Energy Technology Data Exchange (ETDEWEB)

    Marques, Raíssa O.; Vasceoncelos, Vanderley de; Soares, Wellington A.; Silva Júnior, Silvério F.; Raso, Amanda L.; Mesquita, Amir Z., E-mail: raissaomarques@gmail.com, E-mail: vasconv@cdtn.br, E-mail: soaresw@cdtn.br, E-mail: silvasf@cdtn.br, E-mail: amandaraso@hotmail.com, E-mail: amir@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2017-07-01

    Industrial facilities systems deteriorate over time during operation, thus increasing the possibility of accidents. Risk-Based Inspection (RBI) classifies such systems by their risk information with the purpose of prioritizing inspection efforts. RBI can reduce inspection activities, resulting in lower risk levels, and maintaining reliability and safety in acceptable levels. Risk-Informed In-Service Inspection (RI-ISI) is a RBI approach used in nuclear industry. RI-ISI uses outcomes from Probabilistic Safety Analysis (PSA) of Nuclear Power Plants (NPP) to plan In-Service Inspections (ISI). Despite nuclear research reactors are simpler and have lower risks than power reactors, the application of PSA to them may be useful for safety improvements once they are more flexible, provide easier access to its core, and allow changes in fuel configurations in case of experimental tests. Ageing management of structures, systems and components important to safety of a nuclear research reactor throughout its lifetime is also required to assure continued adequacy of safety levels, reliable operation, and compliance with operational limits and conditions. This includes periodic review of ISI programs in which monitoring of material deterioration and aging effects are considered, and that can be supported by the RBI approach. A review of state-of-the-art of PSA and RBI applications to nuclear reactors is presented in this work. Advantages to apply these methodologies are also analyzed. PSA and RBI implementation proposal applied to nuclear research reactors is also presented, as well as its application to a TRIGA research nuclear reactor using computer codes developed by ReliaSoft® Corporation. (author)

  17. Probabilistic safety analysis and risk-based inspection of nuclear research reactors: state-of-the-art and implementation proposal

    International Nuclear Information System (INIS)

    Marques, Raíssa O.; Vasceoncelos, Vanderley de; Soares, Wellington A.; Silva Júnior, Silvério F.; Raso, Amanda L.; Mesquita, Amir Z.

    2017-01-01

    Industrial facilities systems deteriorate over time during operation, thus increasing the possibility of accidents. Risk-Based Inspection (RBI) classifies such systems by their risk information with the purpose of prioritizing inspection efforts. RBI can reduce inspection activities, resulting in lower risk levels, and maintaining reliability and safety in acceptable levels. Risk-Informed In-Service Inspection (RI-ISI) is a RBI approach used in nuclear industry. RI-ISI uses outcomes from Probabilistic Safety Analysis (PSA) of Nuclear Power Plants (NPP) to plan In-Service Inspections (ISI). Despite nuclear research reactors are simpler and have lower risks than power reactors, the application of PSA to them may be useful for safety improvements once they are more flexible, provide easier access to its core, and allow changes in fuel configurations in case of experimental tests. Ageing management of structures, systems and components important to safety of a nuclear research reactor throughout its lifetime is also required to assure continued adequacy of safety levels, reliable operation, and compliance with operational limits and conditions. This includes periodic review of ISI programs in which monitoring of material deterioration and aging effects are considered, and that can be supported by the RBI approach. A review of state-of-the-art of PSA and RBI applications to nuclear reactors is presented in this work. Advantages to apply these methodologies are also analyzed. PSA and RBI implementation proposal applied to nuclear research reactors is also presented, as well as its application to a TRIGA research nuclear reactor using computer codes developed by ReliaSoft® Corporation. (author)

  18. Non-Destructive Techniques Based on Eddy Current Testing

    Science.gov (United States)

    García-Martín, Javier; Gómez-Gil, Jaime; Vázquez-Sánchez, Ernesto

    2011-01-01

    Non-destructive techniques are used widely in the metal industry in order to control the quality of materials. Eddy current testing is one of the most extensively used non-destructive techniques for inspecting electrically conductive materials at very high speeds that does not require any contact between the test piece and the sensor. This paper includes an overview of the fundamentals and main variables of eddy current testing. It also describes the state-of-the-art sensors and modern techniques such as multi-frequency and pulsed systems. Recent advances in complex models towards solving crack-sensor interaction, developments in instrumentation due to advances in electronic devices, and the evolution of data processing suggest that eddy current testing systems will be increasingly used in the future. PMID:22163754

  19. Sensor-based monitoring and inspection of surface morphology in ultraprecision manufacturing processes

    Science.gov (United States)

    Rao, Prahalad Krishna

    This research proposes approaches for monitoring and inspection of surface morphology with respect to two ultraprecision/nanomanufacturing processes, namely, ultraprecision machining (UPM) and chemical mechanical planarization (CMP). The methods illustrated in this dissertation are motivated from the compelling need for in situ process monitoring in nanomanufacturing and invoke concepts from diverse scientific backgrounds, such as artificial neural networks, Bayesian learning, and algebraic graph theory. From an engineering perspective, this work has the following contributions: 1. A combined neural network and Bayesian learning approach for early detection of UPM process anomalies by integrating data from multiple heterogeneous in situ sensors (force, vibration, and acoustic emission) is developed. The approach captures process drifts in UPM of aluminum 6061 discs within 15 milliseconds of their inception and is therefore valuable for minimizing yield losses. 2. CMP process dynamics are mathematically represented using a deterministic multi-scale hierarchical nonlinear differential equation model. This process-machine inter-action (PMI) model is evocative of the various physio-mechanical aspects in CMP and closely emulates experimentally acquired vibration signal patterns, including complex nonlinear dynamics manifest in the process. By combining the PMI model predictions with features gathered from wirelessly acquired CMP vibration signal patterns, CMP process anomalies, such as pad wear, and drifts in polishing were identified in their nascent stage with high fidelity (R2 ~ 75%). 3. An algebraic graph theoretic approach for quantifying nano-surface morphology from optical micrograph images is developed. The approach enables a parsimonious representation of the topological relationships between heterogeneous nano-surface fea-tures, which are enshrined in graph theoretic entities, namely, the similarity, degree, and Laplacian matrices. Topological invariant

  20. Inspection of internal tank welds using the ACFM inspection method

    International Nuclear Information System (INIS)

    Topp, D.A.; Lugg, M.C.

    2009-01-01

    The paper describes recent developments of the ACFM technique and describes several case studies where ACFM has been used to inspect the internal plate welds on large steel storage tanks in refineries. For weld inspection, conventional methods such as magnetic particle inspection or vacuum box testing are generally used. This paper presents comparisons of the results from ACFM with those from the conventional methods, from which conclusions are drawn as to the benefits this technique offers in terms of cost, time savings and inspection reliability. (author)

  1. Steam Generator Inspection Planning Expert System

    International Nuclear Information System (INIS)

    Rzasa, P.

    1987-01-01

    Applying Artificial Intelligence technology to steam generator non-destructive examination (NDE) can help identify high risk locations in steam generators and can aid in preparing technical specification compliant eddy current test (ECT) programs. A steam Generator Inspection Planning Expert System has been developed which can assist NDE or utility personnel in planning ECT programs. This system represents and processes its information using an object oriented declarative knowledge base, heuristic rules, and symbolic information processing, three artificial intelligence based techniques incorporated in the design. The output of the system is an automated generation of ECT programs. Used in an outage inspection, this system significantly reduced planning time

  2. Inspection with non destructive assay techniques of the aluminium coating of the TRIGA Mark III reactor vat; Inspeccion con tecnicas de ensayos no destructivos del recubrimiento de aluminio de la tina del reactor TRIGA Mark III

    Energy Technology Data Exchange (ETDEWEB)

    Reyes A, A.I.; Gonzalez M, A.; Castaneda J, G.; Rivera M, H.; Sandoval G, I. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    2001-07-01

    In June 2000, the Reactor Department assigned to the Scientific Research Direction of the National Institute of Nuclear Research requested to the Non-destructive Assays Laboratory (LEND), assigned to the Materials Science Management, the inspection and measurement of thickness of the aluminium coating (liner) of the TRIGA Mark III reactor vat with non-destructive assay techniques, due to that the aluminium coating is exposed mainly to undergo slimming on its back side due to corrosion phenomena. Activity that was able to be carried out from april until august 2001. It is worth pointing out that this type of inspection with these techniques was realized by first time. The non-destructive assays (NDA) are techniques which use indirect physical methods for inspecting the sanitation of components in process or in service, for detect lack of continuity or defects which affect their quality or usefulness. The application of those do not alter the physical, chemical, mechanical or dimensional properties of the part subject of inspection. The results of the application of the ultrasound inspection techniques, industrial radiography and penetrating liquids are presented. (Author)

  3. A whole process quality control system for energy measuring instruments inspection based on IOT technology

    Science.gov (United States)

    Yin, Bo; Liu, Li; Wang, Jiahan; Li, Xiran; Liu, Zhenbo; Li, Dewei; Wang, Jun; Liu, Lu; Wu, Jun; Xu, Tingting; Cui, He

    2017-10-01

    Electric energy measurement as a basic work, an accurate measurements play a vital role for the economic interests of both parties of power supply, the standardized management of the measurement laboratory at all levels is a direct factor that directly affects the fairness of measurement. Currently, the management of metering laboratories generally uses one-dimensional bar code as the recognition object, advances the testing process by manual management, most of the test data requires human input to generate reports. There are many problems and potential risks in this process: Data cannot be saved completely, cannot trace the status of inspection, the inspection process isn't completely controllable and so on. For the provincial metrology center's actual requirements of the whole process management for the performance test of the power measuring appliances, using of large-capacity RF tags as a process management information media, we developed a set of general measurement experiment management system, formulated a standardized full performance test process, improved the raw data recording mode of experimental process, developed a storehouse automatic inventory device, established a strict test sample transfer and storage system, ensured that all the raw data of the inspection can be traced back, achieved full life-cycle control of the sample, significantly improved the quality control level and the effectiveness of inspection work.

  4. Epidemiologic and economic evaluation of risk-based meat inspection for bovine cysticercosis in Danish cattle

    DEFF Research Database (Denmark)

    Calvo Artavia, Francisco Fernando; Nielsen, Liza Rosenbaum; Alban, L.

    2013-01-01

    line. The exact total NEE for the cattle sector depends on how many and which of the abattoirs that would be able to reorganise the work at the slaughter line to save money on inspection of the head of carcases. Overall, the SSSe was low in all scenarios leading to undetected BC-positive cattle both...

  5. On Container versus Time Based Inspection Policies in Invasive Species Management

    NARCIS (Netherlands)

    Batabyal, A.A.; Nijkamp, P.

    2005-01-01

    We study the problem of precluding biological invasions caused by ships transporting internationally traded goods in containers between different regions of the world. Using the long run expected net cost (LRENC) of inspections as the apposite managerial objective, we address the following important

  6. Application of risk based inspection methodology of API 581 BRD to oil pipelines

    Energy Technology Data Exchange (ETDEWEB)

    Pezzi Filho, M. [Petrobras, Rio de Janeiro (Brazil); Freire, J.L.F.; Maragone, F.. [Pontifica Univ. Catolica, Rio de Janeiro (Brazil)

    2004-07-01

    In response to public concerns regarding the safe operation of pipelines, operators are relying on risk management to balance the demands of pipeline integrity and service competitiveness. This paper presented a procedure for calculating the probability of failure according to the API 581 BRD RB I methodology that uses data collected from 3 existing oil pipelines subject to internal corrosion. The risk exposure that the pipeline may be subjected to during its remaining operating life was evaluated. Risk is a function of the probability of failure and the consequences of that failure. Therefore, if the consequences of the failure are assumed to remain unchanged for a given equipment under specific operational conditions, then risk reduction will only be achieved by decreasing the probability of failure and through management of the inspection process. It was shown that if the confidence on the damage rate and on the inspection effectiveness is known, then it is possible to design an alternative to an existing inspection plan. This calls for pig inspections at 5 year intervals to ensure that the probability of failures for pipelines will be under a certain level of tolerable risk. 9 refs., 4 tabs., 3 figs.

  7. Inspection qualification as a tool to risk based ET ISI of VVER type SG tubes

    International Nuclear Information System (INIS)

    Horacek, L.

    2002-01-01

    A Pilot study on Eddy current inspection qualification of VVER 440 steam generator tubes, discussed in this paper, followed the ENIQ methodology principles and covered briefly the assumed scope of ET qualification, relevant elaborated qualification documents, known ISI limitations and a review of input information on component and defects determined for Eddy current inspection qualification of VVER 440 steam generator tubes. The information includes the fabrication of the test blocks with SG tube segments provided by intended defect simulations of realistic SCC type and basic data on the realistic SCC type defects manufacturing technology. Lessons learned from the development of manufacturing technology of SSC type of defects, regional blind tests, elaboration of the preliminary technical justification for Eddy current automated inspections, potential optimisation of inspection procedures, laboratory and practical open trials are summarised in the paper. The results of the Pilot study also especially in relation to POD curve being determined seem to be useful for practical operational ISI programme and Risk informed ISI decisions and the establishment of plugging criteria of VVER 440 and VVER 1000 type steam generator tubes. (orig.)

  8. Health products inspection

    International Nuclear Information System (INIS)

    Stoltz, M.

    2009-01-01

    To protect public health, the Health Products Inspection is a public service mission where the application of regulations concerning activities on human health products and cosmetic products is verified. This mission permits a global approach to assess the health products risk-based benefit and, in monitoring by laboratory testing and by on site inspections, to verify their compliance with appropriate regulations. The seventy five inspectors perform about eight hundred inspections per year, in France and abroad. These inspections are related to data provided in the health products assessment and also to manufacturing and delivery practices. The French inspection body is also involved in the training of foreign inspectors and in the harmonization of national, European and international practices either for operators than for the competent authorities. (author)

  9. Advanced technique for ultra-thin residue inspection with sub-10nm thickness using high-energy back-scattered electrons

    Science.gov (United States)

    Han, Jin-Hee

    2018-03-01

    Recently the aspect ratio of capacitor and via hole of memory semiconductor device has been dramatically increasing in order to store more information in a limited area. A small amount of remained residues after etch process on the bottom of the high aspect ratio structure can make a critical failure in device operation. Back-scattered electrons (BSE) are mainly used for inspecting the defect located at the bottom of the high aspect ratio structure or analyzing the overlay of the multi-layer structure because these electrons have a high linearity with the direction of emission and a high kinetic energy above 50eV. However, there is a limitation on that it cannot detect ultra-thin residue material having a thickness of several nanometers because the surface sensitivity is extremely low. We studied the characteristics of BSE spectra using Monte Carlo simulations for several cases which the high aspect ratio structures have extreme microscopic residues. Based on the assumption that most of the electrons emitted without energy loss are localized on the surface, we selected the detection energy window which has a range of 20eV below the maximum energy of the BSE. This window section is named as the high-energy BSE region. As a result of comparing the detection sensitivity of the conventional and the high-energy BSE detection mode, we found that the detection sensitivity for the residuals which have 2nm thickness is improved by more than 10 times in the high-energy BSE mode. This BSE technology is a new inspection method that can greatly be improved the inspection sensitivity for the ultra-thin residual material presented in the high aspect ratio structure, and its application will be expanded.

  10. Ultrasonic inspection

    International Nuclear Information System (INIS)

    Satittada, Gannaga

    1984-01-01

    Ultrasonic inspection is one of the most widely used methods for nondestructive inspection. The beam of high-frequency sound wave, ultrasonic wave, is introduced into the material. It travels through the material with some attendant loss of energy and can be reflected at interfaces. The reflected beam is detected and analyzed. Ultrasonic inspection is used to detect flaws in metal parts as well as in welded, brazed and bonded joints during research work and developing production and service. It is also used to detect and locate porosity, pipe, and flakes. In addition, it can be used for the measurement of metal thickness. Ultrasonic inspection is therefore used for quality control and material inspection in all major industries

  11. Development of a novel non-contact inspection technique to detect micro cracks under the surface of a glass substrate by thermal stress-induced light scattering method

    Science.gov (United States)

    Sakata, Yoshitaro; Terasaki, Nao; Nonaka, Kazuhiro

    2017-05-01

    Fine polishing techniques, such as a chemical mechanical polishing treatment, are important techniques in glass substrate manufacturing. However, these techniques may cause micro cracks under the surface of glass substrates because they used mechanical friction. A stress-induced light scattering method (SILSM), which was combined with light scattering method and mechanical stress effects, was proposed for inspecting surfaces to detect polishing-induced micro cracks. However, in the conventional SILSM, samples need to be loaded with physical contact, and the loading point is invisible in transparent materials. Here, we introduced a novel non-contact SILSM using a heating device. A glass substrate was heated first, and then the light scattering intensity of micro cracks was detected by a cooled charge-couple device camera during the natural cooling process. Results clearly showed during the decreasing surface temperature of a glass substrate, appropriate thermal stress is generated for detecting micro cracks by using the SILSM and light scattering intensity from micro cracks changes. We confirmed that non-contact thermal SILSM (T-SILSM) can detect micro cracks under the surface of transparent materials.

  12. Corrosion mapping in ducts using the automated ultrasonic technique C-Scan - correlation with results given by pig inspection; Mapeamento de corrosao em dutos atraves da tecnica ultrassonica C-Scan

    Energy Technology Data Exchange (ETDEWEB)

    Feres Filho, Pedro; Moura, Nestor Carlos de [Physical Acoustics South America (PASA), Sao Paulo, SP (Brazil)

    2005-07-01

    In-service inspection has received diverse contributions from technologies and documents with the objective of maximizing equipment availability and minimizing inadequate repairs. Amongst the available technologies, there are the automated ultrasound tests, in the B and C-scan versions. This paper describes an evaluation methodology based on the correlation between the test techniques of instrumented electromagnetic PIG and automated ultrasound, both applied with the purpose of detecting and mapping areas with corrosion in pipes for oil transport. The main objective of the application of the C-scan methodology, in this case, was the measuring and detailing of the corroded area, thus providing an adequate maintenance plan through the substitution or installation of a double gutter. The result demonstrates the correlation between the measurements taken by the PIG and the sizing of the regions done using the C-scan method, consisting of the length, width and thickness values in the points affected by the corrosion. (author)

  13. DCT-based cyber defense techniques

    Science.gov (United States)

    Amsalem, Yaron; Puzanov, Anton; Bedinerman, Anton; Kutcher, Maxim; Hadar, Ofer

    2015-09-01

    With the increasing popularity of video streaming services and multimedia sharing via social networks, there is a need to protect the multimedia from malicious use. An attacker may use steganography and watermarking techniques to embed malicious content, in order to attack the end user. Most of the attack algorithms are robust to basic image processing techniques such as filtering, compression, noise addition, etc. Hence, in this article two novel, real-time, defense techniques are proposed: Smart threshold and anomaly correction. Both techniques operate at the DCT domain, and are applicable for JPEG images and H.264 I-Frames. The defense performance was evaluated against a highly robust attack, and the perceptual quality degradation was measured by the well-known PSNR and SSIM quality assessment metrics. A set of defense techniques is suggested for improving the defense efficiency. For the most aggressive attack configuration, the combination of all the defense techniques results in 80% protection against cyber-attacks with PSNR of 25.74 db.

  14. Auxiliary feedwater system risk-based inspection guide for the Beaver Valley, Units 1 and 2 nuclear power plants

    International Nuclear Information System (INIS)

    Lloyd, R.C.; Vehec, T.A.; Moffitt, N.E.; Gore, B.F.; Vo, T.V.; Rossbach, L.W.; Sena, P.P. III

    1993-02-01

    In a study sponsored by the US Nuclear Regulatory Commission (NRC), Pacific Northwest Laboratory has developed and applied a methodology for deriving plant-specific risk-based inspection guidance for the auxiliary feedwater (AFW) system at pressurized water reactors that have not undergone probabilistic risk assessment (PRA). This methodology uses existing PRA results and plant operating experience information. Existing PRA-based inspection guidance information recently developed for the NRC for various plants was used to identify generic component failure modes. This information was then combined with plant-specific and industry-wide component information and failure data to identify failure modes and failure mechanisms for the AFW system at the selected plants. Beaver Valley Units 1 and 2 were selected as two of a series of plants for study. The product of this effort is a prioritized listing of AFW failures which have occurred at the plant and at other PWRs. This listing is intended for use by NRC inspectors in the preparation of inspection plans addressing AFW risk-important components at Beaver Valley Units 1 and 2

  15. Auxiliary feedwater system risk-based inspection guide for the J.M. Farley Nuclear Power Plant

    International Nuclear Information System (INIS)

    Vo, T.V.; Pugh, R.; Gore, B.F.; Harrison, D.G.

    1990-10-01

    In a study sponsored by the US Nuclear Regulatory Commission (NRC), Pacific Northwest Laboratory has developed and applied a methodology for deriving plant-specific risk-based inspection guidance for the auxiliary feedwater (AFW) system at pressurized water reactors that have not undergone probabilistic risk assessment(PRA). This methodology uses existing PRA results and plant operating experience information. Existing PRA-based inspection guidance recently developed for the NRC for various plants was used to identify generic component failure modes. This information was then combined with plant-specific and industry-wide component information and failure data to identify failure modes and failure mechanisms for the AFW system at the selected plants. J. M. Farley was selected as the second plant for study. The product of this effort is a prioritized listing of AFW failures which have occurred at the plant and at other PWRs. This listing is intended for use by NRC inspectors in the preparation of inspection plans addressing AFW risk-important at the J. M. Farley plant. 23 refs., 1 fig., 1 tab

  16. Nasal base narrowing: the combined alar base excision technique.

    Science.gov (United States)

    Foda, Hossam M T

    2007-01-01

    To evaluate the role of the combined alar base excision technique in narrowing the nasal base and correcting excessive alar flare. The study included 60 cases presenting with a wide nasal base and excessive alar flaring. The surgical procedure combined an external alar wedge resection with an internal vestibular floor excision. All cases were followed up for a mean of 32 (range, 12-144) months. Nasal tip modification and correction of any preexisting caudal septal deformities were always completed before the nasal base narrowing. The mean width of the external alar wedge excised was 7.2 (range, 4-11) mm, whereas the mean width of the sill excision was 3.1 (range, 2-7) mm. Completing the internal excision first resulted in a more conservative external resection, thus avoiding any blunting of the alar-facial crease. No cases of postoperative bleeding, infection, or keloid formation were encountered, and the external alar wedge excision healed with an inconspicuous scar that was well hidden in the depth of the alar-facial crease. Finally, the risk of notching of the alar rim, which can occur at the junction of the external and internal excisions, was significantly reduced by adopting a 2-layered closure of the vestibular floor (P = .01). The combined alar base excision resulted in effective narrowing of the nasal base with elimination of excessive alar flare. Commonly feared complications, such as blunting of the alar-facial crease or notching of the alar rim, were avoided by using simple modifications in the technique of excision and closure.

  17. Short notice inspections

    International Nuclear Information System (INIS)

    Pouchkarev, V.

    1998-01-01

    For 30 years the IAEA safeguards system have evolved and have been strengthened by the regular introduction of new methods and techniques, improving both its effectiveness and efficiency. The member States of the IAEA have indicated their willingness to accept new obligations and associated technical measure that greatly strengthen the nuclear safeguards system. One element of this is the extent to which the IAEA inspectors have physical access to relevant locations for the purpose of providing independent verification of the exclusively peaceful intent of a State nuclear program. The Protocol to Safeguards granted new legal authority with respect to information on, and short notice inspector access to, all buildings on a nuclear site and administrative agreements that improve the process of designating inspectors and IAEA access to modern means of communication. This report is a short description of unannounced or short notice inspections as measures on which the new strengthened and cost efficient system will be based

  18. A trivariate optimal replacement policy for a deteriorating system based on cumulative damage and inspections

    International Nuclear Information System (INIS)

    Tsai, Hsin-Nan; Sheu, Shey-Huei; Zhang, Zhe George

    2017-01-01

    In this article, we study a trivariate replacement model for a deteriorating system consisting of two units. Failures of unit 1 can be classified into two types. Type I failure (minor failure) is fixed by a minimal repair and type II failure (catastrophic failure) is removed by a replacement. Both types of failures can only be detected through inspection. Each type I failure of unit 1 will result in a random amount of damage to unit 2 and the damages are cumulative. The probability of type I failure or type II failure is assumed to depend on the number of failures since the last replacement. We formulate a replacement policy based on the number of type I failure, the occurrence of the first type II failure, and the amount of accumulative damages. Hence the system is replaced either preventively or correctively at any of the following four conditions depend on whichever occurs first; preventively (a) at the Nth type I failure; or (b) when the total damage of unit 2 exceeds a pre-specified level Z (but less than the failure level l); and, correctively (c) at the first type II failure; or (d) when the total damage of unit 2 exceeds a failure level l, where Z and l represent the thresholds of total damage level for unit 2 to preventive and corrective replacements, respectively. Although a type I failure can be fixed by a minimal repair, but the operating period is stochastically decreasing and repair time is stochastically increasing as time goes on. The minimal total expected long-run net cost per unit time of the system is derived and a computational algorithm for determining the optimal policy is developed. A real-world application from electric power industry is provided. Several past studied are shown to be special cases of our model. Finally, a numerical example is presented. - Highlights: • A trivariate replacement policy for a deteriorating system with two units is proposed. • A real-world application from the electric power industry is provided. • The

  19. Development of ultrasonic testing technique with a large transducer to inspect the containment vessel plates embedded in concrete for corrosion on nuclear power plant (2)

    International Nuclear Information System (INIS)

    Ishida, Hitoshi

    2005-01-01

    The containment vessel plates embedded in concrete on Pressurized Water Reactors are inaccessible to inspect directly. Therefore, it is advisable to prepare inspection technology to detect existence and a location of corrosion on the embedded plates indirectly. The purpose of this study is establishment of ultrasonic testing technique to be able to inspect the containment vessel plates embedded in concrete widely from the accessible point. Experiments to detect artificial hollows simulating corrosion and stud bolts which hold the mold of concrete on a surface of a carbon steel plate mock-up covered with concrete were carried out with newly made low frequency (0.3MHz and 0.5MHz) 90 degrees refraction angle shear horizontal (SH) wave transducers combined with three active elements, which were equivalent to a 120 mm width element. As the results: (1) The echoes from the artificial hollows with a depth of 19 mm and 9.5mm at a distance of 1.5 m and the stud bolts with a diameter of 8mm at a distance of 0.7 - 1.7m could be discriminated clearly. (2) The multiple echoes bouncing three times between the front side and the back side of the plate, which was equivalent to a distance of about 12m, could be discriminated. (3) A divergence angle and a -6dB divergence angle of the large element (combined three elements) transducer were about 7 degrees and about 3 degrees. (4) The echoes from the hollows with a depth of 9.5m could be detected at a distance of 3.6 m with a reflection at the side wall of the mock-up. (5) It was estimated that the maximum distance of detection of the echo from the stud bolt with a diameter of 8mm was about 2.9 ∼ 3.6 m. Therefore we evaluate that the large element transducer can propagate the SH wave to about a half of a distance to the bottom of the embedded containment vessel and it is possible to detect the defects such as corrosion to a distance of 3.6 m. (author)

  20. Drum inspection robots: Application development

    International Nuclear Information System (INIS)

    Hazen, F.B.; Warner, R.D.

    1996-01-01

    Throughout the Department of Energy (DOE), drums containing mixed and low level stored waste are inspected, as mandated by the Resource Conservation and Recovery Act (RCRA) and other regulations. The inspections are intended to prevent leaks by finding corrosion long before the drums are breached. The DOE Office of Science and Technology (OST) has sponsored efforts towards the development of robotic drum inspectors. This emerging application for mobile and remote sensing has broad applicability for DOE and commercial waste storage areas. Three full scale robot prototypes have been under development, and another project has prototyped a novel technique to analyze robotically collected drum images. In general, the robots consist of a mobile, self-navigating base vehicle, outfitted with sensor packages so that rust and other corrosion cues can be automatically identified. They promise the potential to lower radiation dose and operator effort required, while improving diligence, consistency, and documentation

  1. Camber Angle Inspection for Vehicle Wheel Alignments.

    Science.gov (United States)

    Young, Jieh-Shian; Hsu, Hong-Yi; Chuang, Chih-Yuan

    2017-02-03

    This paper introduces an alternative approach to the camber angle measurement for vehicle wheel alignment. Instead of current commercial approaches that apply computation vision techniques, this study aims at realizing a micro-control-unit (MCU)-based camber inspection system with a 3-axis accelerometer. We analyze the precision of the inspection system for the axis misalignments of the accelerometer. The results show that the axes of the accelerometer can be aligned to the axes of the camber inspection system imperfectly. The calibrations that can amend these axis misalignments between the camber inspection system and the accelerometer are also originally proposed since misalignments will usually happen in fabrications of the inspection systems. During camber angle measurements, the x -axis or z -axis of the camber inspection system and the wheel need not be perfectly aligned in the proposed approach. We accomplished two typical authentic camber angle measurements. The results show that the proposed approach is applicable with a precision of ± 0.015 ∘ and therefore facilitates the camber measurement process without downgrading the precision by employing an appropriate 3-axis accelerometer. In addition, the measured results of camber angles can be transmitted via the medium such as RS232, Bluetooth, and Wi-Fi.

  2. Camber Angle Inspection for Vehicle Wheel Alignments

    Directory of Open Access Journals (Sweden)

    Jieh-Shian Young

    2017-02-01

    Full Text Available This paper introduces an alternative approach to the camber angle measurement for vehicle wheel alignment. Instead of current commercial approaches that apply computation vision techniques, this study aims at realizing a micro-control-unit (MCU-based camber inspection system with a 3-axis accelerometer. We analyze the precision of the inspection system for the axis misalignments of the accelerometer. The results show that the axes of the accelerometer can be aligned to the axes of the camber inspection system imperfectly. The calibrations that can amend these axis misalignments between the camber inspection system and the accelerometer are also originally proposed since misalignments will usually happen in fabrications of the inspection systems. During camber angle measurements, the x-axis or z-axis of the camber inspection system and the wheel need not be perfectly aligned in the proposed approach. We accomplished two typical authentic camber angle measurements. The results show that the proposed approach is applicable with a precision of ± 0.015 ∘ and therefore facilitates the camber measurement process without downgrading the precision by employing an appropriate 3-axis accelerometer. In addition, the measured results of camber angles can be transmitted via the medium such as RS232, Bluetooth, and Wi-Fi.

  3. Research on Defects Inspection of Solder Balls Based on Eddy Current Pulsed Thermography

    Directory of Open Access Journals (Sweden)

    Xiuyun Zhou

    2015-10-01

    Full Text Available In order to solve tiny defect detection for solder balls in high-density flip-chip, this paper proposed feasibility study on the effect of detectability as well as classification based on eddy current pulsed thermography (ECPT. Specifically, numerical analysis of 3D finite element inductive heat model is generated to investigate disturbance on the temperature field for different kind of defects such as cracks, voids, etc. The temperature variation between defective and non-defective solder balls is monitored for defects identification and classification. Finally, experimental study is carried on the diameter 1mm tiny solder balls by using ECPT and verify the efficacy of the technique.

  4. Differential Laser Doppler based Non-Contact Sensor for Dimensional Inspection with Error Propagation Evaluation

    Directory of Open Access Journals (Sweden)

    Ketsaya Vacharanukul

    2006-06-01

    Full Text Available To achieve dynamic error compensation in CNC machine tools, a non-contactlaser probe capable of dimensional measurement of a workpiece while it is being machinedhas been developed and presented in this paper. The measurements are automatically fedback to the machine controller for intelligent error compensations. Based on a well resolvedlaser Doppler technique and real time data acquisition, the probe delivers a very promisingdimensional accuracy at few microns over a range of 100 mm. The developed opticalmeasuring apparatus employs a differential laser Doppler arrangement allowing acquisitionof information from the workpiece surface. In addition, the measurements are traceable tostandards of frequency allowing higher precision.

  5. Inspection and Reconstruction of Metal-Roof Deformation under Wind Pressure Based on Bend Sensors

    OpenAIRE

    Yang, Liman; Cui, Langfu; Li, Yunhua; An, Chao

    2017-01-01

    Metal roof sheathings are widely employed in large-span buildings because of their light weight, high strength and corrosion resistance. However, their severe working environment may lead to deformation, leakage and wind-lift, etc. Thus, predicting these damages in advance and taking maintenance measures accordingly has become important to avoid economic losses and personal injuries. Conventionally, the health monitoring of metal roofs mainly relies on manual inspection, which unavoidably com...

  6. Integration of design and inspection

    Science.gov (United States)

    Simmonds, William H.

    1990-08-01

    Developments in advanced computer integrated manufacturing technology, coupled with the emphasis on Total Quality Management, are exposing needs for new techniques to integrate all functions from design through to support of the delivered product. One critical functional area that must be integrated into design is that embracing the measurement, inspection and test activities necessary for validation of the delivered product. This area is being tackled by a collaborative project supported by the UK Government Department of Trade and Industry. The project is aimed at developing techniques for analysing validation needs and for planning validation methods. Within the project an experimental Computer Aided Validation Expert system (CAVE) is being constructed. This operates with a generalised model of the validation process and helps with all design stages: specification of product requirements; analysis of the assurance provided by a proposed design and method of manufacture; development of the inspection and test strategy; and analysis of feedback data. The kernel of the system is a knowledge base containing knowledge of the manufacturing process capabilities and of the available inspection and test facilities. The CAVE system is being integrated into a real life advanced computer integrated manufacturing facility for demonstration and evaluation.

  7. Combined factors effect of menstrual cycle and background noise on visual inspection task performance: a simulation-based task.

    Science.gov (United States)

    Wijayanto, Titis; Tochihara, Yutaka; Wijaya, Andi R; Hermawati, Setia

    2009-11-01

    It is well known that women are physiologically and psychologically influenced by the menstrual cycle. In addition, the presence of background noise may affect task performance. So far, it has proven difficult to describe how the menstrual cycle and background noise affect task performance; some researchers have found an increment of performance during menstruation or during the presence of noise, others found performance deterioration, while other still have reported no dominant effect either of the menstrual cycle in performance or of the presence of noise. However, no study to date has investigated the combinational effect between the menstrual cycle and the presence of background noise in task performance. Therefore, the purpose of this study was to examine the combined factor effect of menstrual cycle and background noise on visual inspection task performance indices by Signal Detection Theory (SDT) metrics: sensitivity index (d') and response criteria index (beta). For this purpose, ten healthy female students (21.5+/-1.08 years) with a regular menstrual cycle participated in this study. A VDT-based visual inspection task was used for the experiment in 3x2 factorial designs. Two factors, menstrual phase, pre-menstruation (PMS), menstruation (M), and post-menstruation (PM) and background noise, with 80 dB(A) background noise and without noise, were analyzed as the main factors in this study. The results concluded that the sensitivity index (d') of SDT was affected in all the menstrual cycle conditions (pbackground noise (pbackground noise was found in this study. On the other hand, no significant effect was observed in the subject's tendency in visual inspection, shown by beta along the menstrual cycle and the presence of background noise. According to the response criteria for each individual subject, the presence of noise affected the tendency of some subjects in detecting the object and making decision during the visual inspection task.

  8. Automated PCB Inspection System

    Directory of Open Access Journals (Sweden)

    Syed Usama BUKHARI

    2017-05-01

    Full Text Available Development of an automated PCB inspection system as per the need of industry is a challenging task. In this paper a case study is presented, to exhibit, a proposed system for an immigration process of a manual PCB inspection system to an automated PCB inspection system, with a minimal intervention on the existing production flow, for a leading automotive manufacturing company. A detailed design of the system, based on computer vision followed by testing and analysis was proposed, in order to aid the manufacturer in the process of automation.

  9. User interface inspection methods a user-centered design method

    CERN Document Server

    Wilson, Chauncey

    2014-01-01

    User Interface Inspection Methods succinctly covers five inspection methods: heuristic evaluation, perspective-based user interface inspection, cognitive walkthrough, pluralistic walkthrough, and formal usability inspections. Heuristic evaluation is perhaps the best-known inspection method, requiring a group of evaluators to review a product against a set of general principles. The perspective-based user interface inspection is based on the principle that different perspectives will find different problems in a user interface. In the related persona-based inspection, colleagues assume the

  10. Surface crack detection by magnetic particle inspection

    International Nuclear Information System (INIS)

    Goebbels, K.

    1988-01-01

    For ferromagnetic materials magnetic particle inspection is without doubt the most sensitive method to detect surface cracks and the least sensitive method referring to disturbing boundary conditions. Up to now the technique is based on experiments, experience, on empirical facts and on a subjective evaluation. This contribution for the first time presents a concept which allows the objective, reproducible as well as reliable magnetic particle inspection: Modelling of testing based on Maxwell's equations by finite element calculation; objective setting of test-parameters and their surveillance, handling systems, illumination and sensors, image processing and fully automated evaluation. Economy and safety of magnetic particle inspection are strongly improved by this procedure. (orig./HP) [de

  11. Hospital Inspections

    Data.gov (United States)

    U.S. Department of Health & Human Services — Welcome to hospitalinspections.org, a website run by the Association of Health Care Journalists (AHCJ) that aims to make federal hospital inspection reports easier...

  12. Inspection program for U.S. research reactors

    International Nuclear Information System (INIS)

    Isaac, Patrick J.

    2010-01-01

    This paper presents an established program for inspection of nuclear research reactors to ensure that systems and techniques are in accordance with regulatory requirements and to provide protection for the health and safety of the public. The inspection program, implemented from the time a facility gets licensed, remains in effect through operations, shutdown, decommissioning, and until the license is terminated. The program establishes inspection methodology for operating, safeguards, and decommissioning activities. Using a performance- based approach, inspectors focus their attention on activities important to safety. Inspection procedures allow the inspectors to assess facility safety and compliance to applicable requirements. A well designed inspection program is an integral part of the mechanism to ensure that the level of performance in the strategic areas of reactor safety, radiation safety, and safeguards is acceptable and provides adequate protection of public health and safety. (author)

  13. On-site inspection: A brief overview and bibliography of techniques pertinent to assessing suspected nuclear test sites

    International Nuclear Information System (INIS)

    Carrigan, C.R.

    1993-03-01

    The purpose of this report is to provide a brief overview and bibliography of those techniques that may have application for the evaluation of a site to determine if a high energy release event is nuclear in nature. This effort is motivated by recognition of the changing world political climate and the perception that low yield and non-proliferation issues will grow in importance as countries become increasingly involved as signators to treaties that are intended to limit the development and testing of nuclear weapons. Along with an increasing interest in such issues is the awareness of the need to implement improved capabilities for treaty monitoring programs that must deal with assessing suspicious occurrences of high energy release events. In preparing this report, it is recognized that monitoring can take two main forms. The first involves the resolution of unidentified events detected by seismic and satellite National Technical Means. Events of an indeterminate nature could occur world-wide and could induce tension in neighboring countries. If an on-site measurement capability were available, a monitoring team could be sent to the suspected site of an event to take measurements that could confirm or disprove the occurrence of a clandestine nuclear test. The second monitoring form is the confirmation that a clandestine event is not masked by a declared event. For example, a large mining explosion could mask a decoupled nuclear explosion. On-site measurements before and during the test could confirm that a clandestine event did not occur and could provide assurance that the party carrying out the explosion is not taking advantage of clandestine testing opportunities. 48 refs

  14. Performance of a tagged neutron inspection system (TNIS) based on portable sealed generators

    International Nuclear Information System (INIS)

    Nebbia, G.; Pesente, S.; Lunardon, M.; Viesti, G.; LeTourneur, P.; Heuveline, F.; Mangeard, M.; Tcheng, C.

    2004-01-01

    A portable sealed neutron generator has been modified to produce 14MeV tagged neutron beams with an embedded YAP:Ce scintillation detector. The system has been tested by detecting the coincident gamma-rays produced in the irradiation of a graphite sample by means of a standard NaI(Tl) scintillator. Time resolution of about δt=4-5ns (FWHM) has been measured. The sealed neutron tube has been operated up to 10 7 neutron/s. Possible applications in non-destructive assays and future developments of the Tagged Neutron Inspection System concept are discussed

  15. Inspection of disposal canisters components

    International Nuclear Information System (INIS)

    Pitkaenen, J.

    2013-12-01

    This report presents the inspection techniques of disposal canister components. Manufacturing methods and a description of the defects related to different manufacturing methods are described briefly. The defect types form a basis for the design of non-destructive testing because the defect types, which occur in the inspected components, affect to choice of inspection methods. The canister components are to nodular cast iron insert, steel lid, lid screw, metal gasket, copper tube with integrated or separate bottom, and copper lid. The inspection of copper material is challenging due to the anisotropic properties of the material and local changes in the grain size of the copper material. The cast iron insert has some acoustical material property variation (attenuation, velocity changes, scattering properties), which make the ultrasonic inspection demanding from calibration point of view. Mainly three different methods are used for inspection. Ultrasonic testing technique is used for inspection of volume, eddy current technique, for copper components only, and visual testing technique are used for inspection of the surface and near surface area

  16. Information-Driven Inspections

    International Nuclear Information System (INIS)

    Laughter, Mark D.; Whitaker, J. Michael; Lockwood, Dunbar

    2010-01-01

    New uranium enrichment capacity is being built worldwide in response to perceived shortfalls in future supply. To meet increasing safeguards responsibilities with limited resources, the nonproliferation community is exploring next-generation concepts to increase the effectiveness and efficiency of safeguards, such as advanced technologies to enable unattended monitoring of nuclear material. These include attribute measurement technologies, data authentication tools, and transmission and security methods. However, there are several conceptual issues with how such data would be used to improve the ability of a safeguards inspectorate such as the International Atomic Energy Agency (IAEA) to reach better safeguards conclusions regarding the activities of a State. The IAEA is pursuing the implementation of information-driven safeguards, whereby all available sources of information are used to make the application of safeguards more effective and efficient. Data from continuous, unattended monitoring systems can be used to optimize on-site inspection scheduling and activities at declared facilities, resulting in fewer, better inspections. Such information-driven inspections are the logical evolution of inspection planning - making use of all available information to enhance scheduled and randomized inspections. Data collection and analysis approaches for unattended monitoring systems can be designed to protect sensitive information while enabling information-driven inspections. A number of such inspections within a predetermined range could reduce inspection frequency while providing an equal or greater level of deterrence against illicit activity, all while meeting operator and technology holder requirements and reducing inspector and operator burden. Three options for using unattended monitoring data to determine an information-driven inspection schedule are to (1) send all unattended monitoring data off-site, which will require advances in data analysis techniques to

  17. Inspecting what you expect: Applying modern tools and techniques to evaluate the effectiveness of household energy interventions

    Science.gov (United States)

    Pillarisetti, Ajay

    Exposure to fine particles (PM2.5) resulting from solid fuel use for household energy needs - including cooking, heating, and lighting - is one of the leading causes of ill-health globally and is responsible for approximately 4 million premature deaths and 84 million lost disability-adjusted life years globally. The well-established links between cooking and ill-health are modulated by complex social, behavioral, technological, and environmental issues that pose unique challenges to efforts that seek to reduce this large health burden. Despite growing interest in the field - and numerous technical solutions that, in the laboratory at least, reduce emissions of harmful air pollutants from solid fuel combustion - there exists a need for refined tools, models, and techniques (1) for measuring environmental pollution in households using solid fuel, (2) for tracking adoption of interventions, and (3) for estimating the potential health benefits attributable to an intervention. Part of the need for higher spatial and temporal resolution data on particular concentrations and dynamics is being met by low-cost sensing platforms that provide large amounts of time-resolved data on critical parameters of interest, including PM2.5 concentrations and time-of-use metrics for heat-generating appliances, like stoves. Use of these sensors can result in non-trivial challenges, including those related to data management and analysis, and field logistics, but also enables novel lines of inquiry and insight. Chapter 2 presents a long-term deployment of real-time PM2.5 sensors in rural, solid-fuel-using kitchens, specifically seeking to evaluate how well commonly measured 24 or 48-hour samples represent long-term means. While short-term measures were poor predictors of long-term means, the dataset enabled evaluation of numerous sampling strategies - including sampling once per week, month, or season - that had much lower errors and higher probabilities of estimating the true mean

  18. Synchrotron radiation based analytical techniques (XAS and XRF)

    International Nuclear Information System (INIS)

    Jha, Shambhu Nath

    2014-01-01

    A brief description of the principles of X-ray absorption spectroscopy (XAS) and X-ray fluorescence (XRF) techniques is given in this article with emphasis on the advantages of using synchrotron radiation-based instrumentation/beamline. XAS technique is described in more detail to emphasize the strength of the technique as a local structural probe. (author)

  19. NRF Based Nondestructive Inspection System for SNM by Using Laser-Compton-Backscattering Gamma-Rays

    Science.gov (United States)

    Ohgaki, H.; Omer, M.; Negm, H.; Daito, I.; Zen, H.; Kii, T.; Masuda, K.; Hori, T.; Hajima, R.; Hayakawa, T.; Shizuma, T.; Kando, M.

    2015-10-01

    A non-destructive inspection system for special nuclear materials (SNMs) hidden in a sea cargo has been developed. The system consists of a fast screening system using neutron generated by inertial electrostatic confinement (IEC) device and an isotope identification system using nuclear resonance fluorescence (NRF) measurements with laser Compton backscattering (LCS) gamma-rays has been developed. The neutron flux of 108 n/sec has been achieved by the IEC in static mode. We have developed a modified neutron reactor noise analysis method to detect fission neutron in a short time. The LCS gamma-rays has been generated by using a small racetrack microtoron accelerator and an intense sub-nano second laser colliding head-on to the electron beam. The gamma-ray flux has been achieved more than 105 photons/s. The NRF gamma-rays will be measured using LaBr3(Ce) scintillation detector array whose performance has been measured by NRF experiment of U-235 in HIGS facility. The whole inspection system has been designed to satisfy a demand from the sea port.

  20. An Automated Sorting System Based on Virtual Instrumentation Techniques

    Directory of Open Access Journals (Sweden)

    Rodica Holonec

    2008-07-01

    Full Text Available The application presented in this paper represents an experimental model and it refers to the implementing of an automated sorting system for pieces of same shape but different sizes and/or colors. The classification is made according to two features: the color and weight of these pieces. The system is a complex combination of NI Vision hardware and software tools, strain gauges transducers, signal conditioning connected to data acquisition boards, motion and control elements. The system is very useful for students to learn and experiment different virtual instrumentation techniques in order to be able to develop a large field of applications from inspection and process control to sorting and assembly

  1. A study on the crack inspection signal characteristics for power plant components by phased array UT

    International Nuclear Information System (INIS)

    Cho, Yong Sang; Lim, Sang Gyu; Kil, Du Song

    2001-01-01

    Phased array ultrasonic testing system has become available for practical application in complicated geometry such as turbine blade root, tenon, disc in power industry. This research describes the characteristics of phased array UT signal for various type of blade roots in thermal Power Plant turbines. This application of Phased array ultrasonic testing system has been promoted mainly to save inspection time and labor cost of turbine inspection. The characteristic of phase array UT signal for power plant component is very simple to understand but to difficult for perform the inspection. Since our sophisticated inspection technique and systems are essential for the inspection of steam turbine blade roots that require high reliability, we intend to develop new technology and improve phased array technique based on the wide and much experience for the inspection of turbine components.

  2. Development and application of proposed ASME Section XI Code changes for risk-based inspection of piping

    International Nuclear Information System (INIS)

    West, R.A.

    1996-01-01

    This synopsis has been written to describe a perspective on the development and application of ASME Section XI Code changes for risk-based inspection of piping. The content is specifically related to the use of risk-based technology for Inservice Inspection (ISI) of piping and efforts made to support the ASME Research/Westinghouse Owners Group/Millstone Unit 3 approach for use of this technology. The opinions contained herein may or may not reflect those of the ASME Codes and Standards Committees responsible for these activities. In order to take such a detailed technical subject and put it into an understandable format, the author has chosen to provide an analogy to simplify what is actually taking place. Risk-based technology in the ISI of piping can be likened to the process of making and using specifically ground prescription glasses to allow for better vision. It provides a process to develop and use these uniquely ground glasses that will dynamically focus on all the locations and obstacles within a plant's piping systems that could cause that plant to trip and fall; more importantly it identifies the locations where the fall could possibly hurt someone else. In this way, Nuclear Safety is being addressed

  3. Inspection of bottom and lid welds for disposal canisters

    International Nuclear Information System (INIS)

    Pitkaenen, J.

    2010-09-01

    This report presents the inspection techniques of copper electron beam and friction stir welds. Both welding methods are described briefly and a more detailed description of the defects occurring in each welding methods is given. The defect types form a basis for the design of non-destructive testing. The inspection of copper material is challenging due to the anisotropic properties of the weld and local changes in the grain size of the base material. Four different methods are used for inspection. Ultrasonic and radiographic testing techniques are used for inspection of volume. Eddy current and visual testing techniques are used for inspection of the surface and near surface area. All these methods have some limitations which are related to the physics of the used method. All inspection methods need to be carried out remotely because of the radiation from the spent nuclear fuel. All methods have been described in detail and the use of the chosen inspection techniques has been justified. Phased array technology has been applied in ultrasonic testing. Ultrasonic phased array technology enables the electrical modification of the sound field during inspection so that the sound field can be adjusted dynamically for different situations and detection of different defect types. The frequency of the phased array probe has been chosen to be 3.5 MHz. It is a compromise between good sizing and defect detectability. It must be taken into account that ultrasonic testing is not suitable for detection of defect types which are in the direction of the beam. Ultrasonic and radiographic testing techniques complement each other in case of planar defects. Positioning of the indication in the radial direction is rather limited in radiographic testing. Surface inspection has been added to the inspection routine because indications from the outer surface of the canister cannot be distinguished from weld defects in the radiographic image. A 9 MeV linear accelerator has been used in the

  4. Accelerator based techniques for contraband detection

    Science.gov (United States)

    Vourvopoulos, George

    1994-05-01

    It has been shown that narcotics, explosives, and other contraband materials, contain various chemical elements such as H, C, N, O, P, S, and Cl in quantities and ratios that differentiate them from each other and from other innocuous substances. Neutrons and γ-rays have the ability to penetrate through various materials at large depths. They are thus able, in a non-intrusive way, to interrogate volumes ranging from suitcases to Sea-Land containers, and have the ability to image the object with an appreciable degree of reliability. Neutron induced reactions such as (n, γ), (n, n') (n, p) or proton induced γ-resonance absorption are some of the reactions currently investigated for the identification of the chemical elements mentioned above. Various DC and pulsed techniques are discussed and their advantages, characteristics, and current progress are shown. Areas where use of these methods is currently under evaluation are detection of hidden explosives, illicit drug interdiction, chemical war agents identification, nuclear waste assay, nuclear weapons destruction and others.

  5. An Authentication Technique Based on Classification

    Institute of Scientific and Technical Information of China (English)

    李钢; 杨杰

    2004-01-01

    We present a novel watermarking approach based on classification for authentication, in which a watermark is embedded into the host image. When the marked image is modified, the extracted watermark is also different to the original watermark, and different kinds of modification lead to different extracted watermarks. In this paper, different kinds of modification are considered as classes, and we used classification algorithm to recognize the modifications with high probability. Simulation results show that the proposed method is potential and effective.

  6. Container Inspection Utilizing 14 MeV Neutrons

    Science.gov (United States)

    Valkovic, Vladivoj; Sudac, Davorin; Nad, Karlo; Obhodas, Jasmina

    2016-06-01

    A proposal for an autonomous and flexible ship container inspection system is presented. This could be accomplished by the incorporation of an inspection system on various container transportation devices (straddle carriers, yard gentry cranes, automated guided vehicles, trailers). The configuration is terminal specific and it should be defined by the container terminal operator. This enables that no part of the port operational area is used for inspection. The inspection scenario includes container transfer from ship to transportation device with the inspection unit mounted on it. The inspection is performed during actual container movement to the container location. A neutron generator without associated alpha particle detection is used. This allows the use of higher neutron intensities (5 × 109 - 1010 n/s in 4π). The inspected container is stationary in the “inspection position” on the transportation device while the “inspection unit” moves along its side. The following analytical methods will be used simultaneously: neutron radiography, X-ray radiography, neutron activation analysis, (n, γ) and (n,n'γ) reactions, neutron absorption. and scattering, X-ray backscattering. The neutron techniques will utilize “smart collimators” for neutrons and gamma rays, both emitted and detected. The inspected voxel is defined by the intersection of the neutron generator and the detectors solid angles. The container inspection protocol is based on identification of discrepancies between the cargo manifest, elemental “fingerprint” and radiography profiles. In addition, the information on container weight is obtained during the container transport and screening by measuring of density of material in the container.

  7. Laser-based techniques for combustion diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Georgiev, N.

    1997-04-01

    Two-photon-induced Degenerate Four-Wave Mixing, DFWM, was applied for the first time to the detection of CO, and NH{sub 3} molecules. Measurements were performed in a cell, and in atmospheric-pressure flames. In the cell measurements, the signal dependence on the pressure and on the laser beam intensity was studied. The possibility of simultaneous detection of NH{sub 3} and OH was investigated. Carbon monoxide and ammonia were also detected employing two-photon-induced Polarization Spectroscopy, PS. In the measurements performed in a cold gas flow, the signal strength dependence on the laser intensity, and on the polarization of the pump beam, was investigated. An approach to improve the spatial resolution of the Amplified Stimulated Emission, ASE, was developed. In this approach, two laser beams at different frequencies were crossed in the sample. If the sum of the frequencies of the two laser beams matches a two photon resonance of the investigated species, only the molecules in the intersection volume will be excited. NH{sub 3} molecules and C atoms were studied. The potential of using two-photon LIF for two-dimensional imaging of combustion species was investigated. Although LIF is species specific, several species can be detected simultaneously by utilizing spectral coincidences. Combining one- and two-photon process, OH, NO, and O were detected simultaneously, as well as OH, NO, and NH{sub 3}. Collisional quenching is the major source of uncertainty in quantitative applications of LIF. A technique for two-dimensional, absolute species concentration measurements, circumventing the problems associated with collisional quenching, was developed. By applying simple mathematics to the ratio of two LIF signals generated from two counterpropagating laser beams, the absolute species concentration could be obtained. 41 refs

  8. Operational inspections

    International Nuclear Information System (INIS)

    Bystersky, M.

    1997-01-01

    Special equipment is described, designed for inspection of reactor pressure vessels performed from the inside. Central shaft manipulator ZMM-5 is available for crack detection control using ultrasound and eddy currents, for visual check of surfaces, repair works at the reactor pressure vessel, and hardness measurements. The manipulator consists of the manipulator bridge, a cable container, shaft segments, a control mechanism and auxiliary parts. Eight inspections were performed at the Bohunice nuclear power plant and two at the Paks nuclear power plant. (M.D.)

  9. Endoscopic inspection of steam turbines

    International Nuclear Information System (INIS)

    Maliniemi, H.; Muukka, E.

    1990-01-01

    For over ten years, Imatran Voima Oy (IVO) has developed, complementary inspection methods for steam turbine condition monitoring, which can be applied both during operation and shutdown. One important method used periodically during outages is endoscopic inspection. The inspection is based on the method where the internal parts of the turbine is inspected through access borings with endoscope and where the magnified figures of the internal parts is seen on video screen. To improve inspection assurance, an image-processing based pattern recognition method for cracks has been developed for the endoscopic inspection of turbine blades. It is based on the deduction conditions derived from the crack shape. The computer gives an alarm of a crack detection and prints a simulated image of the crack, which is then checked manually

  10. Historical occupational trichloroethylene air concentrations based on inspection measurements from Shanghai, China.

    Science.gov (United States)

    Friesen, Melissa C; Locke, Sarah J; Chen, Yu-Cheng; Coble, Joseph B; Stewart, Patricia A; Ji, Bu-Tian; Bassig, Bryan; Lu, Wei; Xue, Shouzheng; Chow, Wong-Ho; Lan, Qing; Purdue, Mark P; Rothman, Nathaniel; Vermeulen, Roel

    2015-01-01

    Trichloroethylene (TCE) is a carcinogen that has been linked to kidney cancer and possibly other cancer sites including non-Hodgkin lymphoma. Its use in China has increased since the early 1990s with China's growing metal, electronic, and telecommunications industries. We examined historical occupational TCE air concentration patterns in a database of TCE inspection measurements collected in Shanghai, China to identify temporal trends and broad contrasts among occupations and industries. Using a database of 932 short-term, area TCE air inspection measurements collected in Shanghai worksites from 1968 through 2000 (median year 1986), we developed mixed-effects models to evaluate job-, industry-, and time-specific TCE air concentrations. Models of TCE air concentrations from Shanghai work sites predicted that exposures decreased 5-10% per year between 1968 and 2000. Measurements collected near launderers and dry cleaners had the highest predicted geometric means (GM for 1986 = 150-190 mg m(-3)). The majority (53%) of the measurements were collected in metal treatment jobs. In a model restricted to measurements in metal treatment jobs, predicted GMs for 1986 varied 35-fold across industries, from 11 mg m(-3) in 'other metal products/repair' industries to 390 mg m(-3) in 'ships/aircrafts' industries. TCE workplace air concentrations appeared to have dropped over time in Shanghai, China between 1968 and 2000. Understanding differences in TCE concentrations across time, occupations, and industries may assist future epidemiologic studies in China. Published by Oxford University Press on behalf of the British Occupational Hygiene Society 2014.

  11. Ultrasonic inspections of fuel alignment pins

    International Nuclear Information System (INIS)

    Rathgeb, W.; Schmid, R.

    1994-01-01

    As a remedy to the practical problem of defects in fuel alignment pins made of Inconel X750, an inspection technique has been developed which fully meets the requirements of detecting defects. The newly used fuel alignment pins made of austenite are easy to test and therefore satisfy the necessity of further inspections.For the fuel alignment pins of the upper core structure a safe and fast inspection technique was made available. The inspection sensitivity is high and it is possible to give quantitative directions concerning defect orientation and depth. After the required inspections had been concluded in 1989, a total of 18 inspections were carried out in various national and international nuclear power plants in the following years. During this time more than 6000 fuel alignment pines were examined.For the fuel alignment pins the inspection technique provided could increase the understanding of the defect process. This technique contributed to the development of an adaptive and economical repair strategy. ((orig.))

  12. Packaging supplier inspection guide

    International Nuclear Information System (INIS)

    Stromberg, H.M.; Gregg, R.E.; Kido, C.; Boyle, C.D.

    1991-05-01

    This is document is a guide for conducting quality assurance inspections of transportations packaging suppliers, where suppliers are defined as designers, fabricators, distributors, users, or owners of transportation packaging. This document can be used during an inspection to determine regulatory compliance within the requirements of 10 Code of Federal Regulations, Part 71, Subpart H (10 CFR 71.101--71.135). The guidance described in this document provides a framework for an inspection. It provides the inspector with the flexibility to adapt the methods and concepts presented here to meet the needs of the particular facility being inspected. The guide was developed to ensure a structured and consistent approach for inspections. The method treats each activity at a supplier facility as a separate entity (or functional element), and combines the activities within the framework of an ''inspection tree.'' The method separates each functional element into several areas of performance and then identifies guidelines, based on regulatory requirements, to be used to qualitatively rate each area. This document was developed to serve as a field manual to facilitate the work of inspectors. 1 ref., 1 fig., 5 tabs

  13. Do school inspections improve primary school performance?

    OpenAIRE

    Dinand Webbink; Rob Luginbuhl; I. de Wolf

    2007-01-01

    Inspectors from the Dutch Inspectorate of Education inspect primary schools, write inspection reports on each inspected school, and make recommendations as to how each school can improve. We test whether these inspections result in better school performance. Using a fixed-effects model, we find evidence that school inspections do lead to measurably better school performance. Our assessment of school performance is based on the Cito test scores of pupils in their final year of primary school. ...

  14. Austenitic stainless steel weld inspection

    International Nuclear Information System (INIS)

    Mech, S.J.; Emmons, J.S.; Michaels, T.E.

    1978-01-01

    Analytical techniques applied to ultrasonic waveforms obtained from inspection of austenitic stainless steel welds are described. Experimental results obtained from a variety of geometric and defect reflectors are presented. Specifically, frequency analyses parameters, such as simple moments of the power spectrum, cross-correlation techniques, and adaptive learning network analysis, all represent improvements over conventional time domain analysis of ultrasonic waveforms. Results for each of these methods are presented, and the overall inspection difficulties of austenitic stainless steel welds are discussed

  15. Savannah River Plant waste tank inspection manual

    International Nuclear Information System (INIS)

    McNatt, F.G.

    1979-01-01

    This manual is to aid in making visual and photographic inspections and steel thickness measurements of Building 241-F and -H underground waste storage tanks. It describes the inspection program, the storage tanks, the equipment and techniques used and the results of their application, and the inspection recordkeeping methods

  16. Mechanized ultrasonic inspection of austenitic pipe systems

    International Nuclear Information System (INIS)

    Dressler, K.; Luecking, J.; Medenbach, S.

    1999-01-01

    The contribution explains the system of standard testing methods elaborated by ABB ZAQ GmbH for inspection of austenitic plant components. The inspection tasks explained in greater detail are basic materials testing (straight pipes, bends, and pipe specials), and inspection of welds and dissimilar welds. The techniques discussed in detail are those for detection and sizing of defects. (orig./CB) [de

  17. Remotely deployable aerial inspection using tactile sensors

    Science.gov (United States)

    MacLeod, C. N.; Cao, J.; Pierce, S. G.; Sullivan, J. C.; Pipe, A. G.; Dobie, G.; Summan, R.

    2014-02-01

    For structural monitoring applications, the use of remotely deployable Non-Destructive Evaluation (NDE) inspection platforms offer many advantages, including improved accessibility, greater safety and reduced cost, when compared to traditional manual inspection techniques. The use of such platforms, previously reported by researchers at the University Strathclyde facilitates the potential for rapid scanning of large areas and volumes in hazardous locations. A common problem for both manual and remote deployment approaches lies in the intrinsic stand-off and surface coupling issues of typical NDE probes. The associated complications of these requirements are obviously significantly exacerbated when considering aerial based remote inspection and deployment, resulting in simple visual techniques being the preferred sensor payload. Researchers at Bristol Robotics Laboratory have developed biomimetic tactile sensors modelled on the facial whiskers (vibrissae) of animals such as rats and mice, with the latest sensors actively sweeping their tips across the surface in a back and forth motion. The current work reports on the design and performance of an aerial inspection platform and the suitability of tactile whisking sensors to aerial based surface monitoring applications.

  18. Huffman-based code compression techniques for embedded processors

    KAUST Repository

    Bonny, Mohamed Talal

    2010-09-01

    The size of embedded software is increasing at a rapid pace. It is often challenging and time consuming to fit an amount of required software functionality within a given hardware resource budget. Code compression is a means to alleviate the problem by providing substantial savings in terms of code size. In this article we introduce a novel and efficient hardware-supported compression technique that is based on Huffman Coding. Our technique reduces the size of the generated decoding table, which takes a large portion of the memory. It combines our previous techniques, Instruction Splitting Technique and Instruction Re-encoding Technique into new one called Combined Compression Technique to improve the final compression ratio by taking advantage of both previous techniques. The instruction Splitting Technique is instruction set architecture (ISA)-independent. It splits the instructions into portions of varying size (called patterns) before Huffman coding is applied. This technique improves the final compression ratio by more than 20% compared to other known schemes based on Huffman Coding. The average compression ratios achieved using this technique are 48% and 50% for ARM and MIPS, respectively. The Instruction Re-encoding Technique is ISA-dependent. It investigates the benefits of reencoding unused bits (we call them reencodable bits) in the instruction format for a specific application to improve the compression ratio. Reencoding those bits can reduce the size of decoding tables by up to 40%. Using this technique, we improve the final compression ratios in comparison to the first technique to 46% and 45% for ARM and MIPS, respectively (including all overhead that incurs). The Combined Compression Technique improves the compression ratio to 45% and 42% for ARM and MIPS, respectively. In our compression technique, we have conducted evaluations using a representative set of applications and we have applied each technique to two major embedded processor architectures

  19. Knowledge-based inspection:modelling complex processes with the integrated Safeguards Modelling Method (iSMM)

    International Nuclear Information System (INIS)

    Abazi, F.

    2011-01-01

    Increased level of complexity in almost every discipline and operation today raises the demand for knowledge in order to successfully run an organization whether to generate profit or to attain a non-profit mission. Traditional way of transferring knowledge to information systems rich in data structures and complex algorithms continue to hinder the ability to swiftly turnover concepts into operations. Diagrammatic modelling commonly applied in engineering in order to represent concepts or reality remains to be an excellent way of converging knowledge from domain experts. The nuclear verification domain represents ever more a matter which has great importance to the World safety and security. Demand for knowledge about nuclear processes and verification activities used to offset potential misuse of nuclear technology will intensify with the growth of the subject technology. This Doctoral thesis contributes with a model-based approach for representing complex process such as nuclear inspections. The work presented contributes to other domains characterized with knowledge intensive and complex processes. Based on characteristics of a complex process a conceptual framework was established as the theoretical basis for creating a number of modelling languages to represent the domain. The integrated Safeguards Modelling Method (iSMM) is formalized through an integrated meta-model. The diagrammatic modelling languages represent the verification domain and relevant nuclear verification aspects. Such a meta-model conceptualizes the relation between practices of process management, knowledge management and domain specific verification principles. This fusion is considered as necessary in order to create quality processes. The study also extends the formalization achieved through a meta-model by contributing with a formalization language based on Pattern Theory. Through the use of graphical and mathematical constructs of the theory, process structures are formalized enhancing

  20. Proof of pipeline strength based on measurements of inspection pigs; Festigkeitsnachweis von Pipelines aufgrund der Messergebnisse von Pruefmolchen

    Energy Technology Data Exchange (ETDEWEB)

    De la Camp, H.J.; Feser, G.; Hofmann, A.; Wolf, B.; Schmidt, H. [TUeV Sueddeutschland Bau und Betrieb GmbH, Muenchen (Germany); Herforth, H.E.; Juengling, K.H.; Schmidt, W. [TUeV Anlagentechnik GmbH, Berlin-Schoeneberg (Germany). Unternehmensgruppe TUeV Rheinland/Berlin-Brandenburg

    2002-01-01

    The report is aimed at collecting and documenting the state of the art and the extensive know how of experts and pipeline operators with regard to judging the structural integrity of pipelines. In order to assess the actual mechanical strength of pipelines based on measurement results obtained by inspection pigs, guidance is given for future processing, which eventually can be used as a basis for an industry standard. A literature study of the commercially available types of inspection pigs describes and synoptically lists the respective pros and cons. In essence the report comprises besides check lists of operating data for the pipeline and the pig runs mainly the evaluation of defects and respective calculating procedures. Included are recommendations regarding maintenance planning, verification of defects as well as repetition of pig runs. (orig.) [German] Ziel des Berichtes ist die Erfassung und Dokumentation zum derzeitigen Stand der Technik und des vorhandenen umfangreichen Know-how von Sachverstaendigen und Pipelinebetreibern auf dem Gebiet der sicherheitstechnischen Beurteilung von Pipelines. Fuer den Festigkeitsnachweis von Pipelines aufgrund der Messergebnisse von Pruefmolchen wurde ein Leitfaden als Basis fuer die zukuenftige Vorgehensweise erstellt, der eventuell die Grundlage eines normativen Regelwerkes bilden kann. In einer Literaturstudie wurden die auf dem Markt befindlichen Pruefmolchtypen zusammenfassend beschrieben und ihre Vor- und Nachteile tabellarisch gegenuebergestellt und bewertet. Neben der Erstellung von Checklisten fuer notwendige Daten zum Betrieb der Pipeline und der Molchlaeufe bildet die Fehlerbewertung mit entsprechenden Berechnungsverfahren den Hauptteil dieses Berichtes. Hinweise zur Instandhaltungsplanung (Fehlerverifikation und Molchlaufwiederholung) werden gegeben. (orig.)

  1. Application of polarization in high speed, high contrast inspection

    Science.gov (United States)

    Novak, Matthew J.

    2017-08-01

    Industrial optical inspection often requires high speed and high throughput of materials. Engineers use a variety of techniques to handle these inspection needs. Some examples include line scan cameras, high speed multi-spectral and laser-based systems. High-volume manufacturing presents different challenges for inspection engineers. For example, manufacturers produce some components in quantities of millions per month, per week or even per day. Quality control of so many parts requires creativity to achieve the measurement needs. At times, traditional vision systems lack the contrast to provide the data required. In this paper, we show how dynamic polarization imaging captures high contrast images. These images are useful for engineers to perform inspection tasks in some cases where optical contrast is low. We will cover basic theory of polarization. We show how to exploit polarization as a contrast enhancement technique. We also show results of modeling for a polarization inspection application. Specifically, we explore polarization techniques for inspection of adhesives on glass.

  2. Projector-Based Augmented Reality for Quality Inspection of Scanned Objects

    Science.gov (United States)

    Kern, J.; Weinmann, M.; Wursthorn, S.

    2017-09-01

    After scanning or reconstructing the geometry of objects, we need to inspect the result of our work. Are there any parts missing? Is every detail covered in the desired quality? We typically do this by looking at the resulting point clouds or meshes of our objects on-screen. What, if we could see the information directly visualized on the object itself? Augmented reality is the generic term for bringing virtual information into our real environment. In our paper, we show how we can project any 3D information like thematic visualizations or specific monitoring information with reference to our object onto the object's surface itself, thus augmenting it with additional information. For small objects that could for instance be scanned in a laboratory, we propose a low-cost method involving a projector-camera system to solve this task. The user only needs a calibration board with coded fiducial markers to calibrate the system and to estimate the projector's pose later on for projecting textures with information onto the object's surface. Changes within the projected 3D information or of the projector's pose will be applied in real-time. Our results clearly reveal that such a simple setup will deliver a good quality of the augmented information.

  3. A Generic Deep-Learning-Based Approach for Automated Surface Inspection.

    Science.gov (United States)

    Ren, Ruoxu; Hung, Terence; Tan, Kay Chen

    2018-03-01

    Automated surface inspection (ASI) is a challenging task in industry, as collecting training dataset is usually costly and related methods are highly dataset-dependent. In this paper, a generic approach that requires small training data for ASI is proposed. First, this approach builds classifier on the features of image patches, where the features are transferred from a pretrained deep learning network. Next, pixel-wise prediction is obtained by convolving the trained classifier over input image. An experiment on three public and one industrial data set is carried out. The experiment involves two tasks: 1) image classification and 2) defect segmentation. The results of proposed algorithm are compared against several best benchmarks in literature. In the classification tasks, the proposed method improves accuracy by 0.66%-25.50%. In the segmentation tasks, the proposed method reduces error escape rates by 6.00%-19.00% in three defect types and improves accuracies by 2.29%-9.86% in all seven defect types. In addition, the proposed method achieves 0.0% error escape rate in the segmentation task of industrial data.

  4. Array-based techniques for fingerprinting medicinal herbs

    Directory of Open Access Journals (Sweden)

    Xue Charlie

    2011-05-01

    Full Text Available Abstract Poor quality control of medicinal herbs has led to instances of toxicity, poisoning and even deaths. The fundamental step in quality control of herbal medicine is accurate identification of herbs. Array-based techniques have recently been adapted to authenticate or identify herbal plants. This article reviews the current array-based techniques, eg oligonucleotides microarrays, gene-based probe microarrays, Suppression Subtractive Hybridization (SSH-based arrays, Diversity Array Technology (DArT and Subtracted Diversity Array (SDA. We further compare these techniques according to important parameters such as markers, polymorphism rates, restriction enzymes and sample type. The applicability of the array-based methods for fingerprinting depends on the availability of genomics and genetics of the species to be fingerprinted. For the species with few genome sequence information but high polymorphism rates, SDA techniques are particularly recommended because they require less labour and lower material cost.

  5. Development of high-sensitivity ultrasonic techniques for in-service inspection of nuclear reactors. Annual report, July 1, 1975--June 30, 1976

    International Nuclear Information System (INIS)

    Linzer, M.

    1977-02-01

    Substantial progress was made in the development of improved ultrasonic techniques based on real-time signal averaging, pulse compression, multifrequency transception, and compact electromagnetic transducers. A preliminary correlation was established between ultrasonic velocity and the degree of sensitization of stainless steel

  6. Dual view x-ray inspection system for foreign objects detection in canned food

    Science.gov (United States)

    Lu, Zhiwen; Peng, Ningsong

    2013-04-01

    X-ray inspection technique for foreign objects in food products can determine and mark the presence of contaminants within the product by using image processing and pattern recognition technique on the X-ray transmission images. This paper presents the dual view X-ray inspection technique for foreign objects in food jar via analyzing the weak points of the traditional single view X-ray inspection technique. In addition, a prototype with the new technique is developed in accordance with glass splinters detection within the food jar (glass jar especially) which is a typical tickler. Some algorithms such as: adaptive image segmentation based on contour tracking, nonlinear arctan function transform and etc., are applied to improve image quality and achieve effective inspection results. The false recognition rate is effectively reduced and the detection sensitivity is highly enhanced. Finally the actual test results of this prototype are given.

  7. Experience on inspection at PFPF

    International Nuclear Information System (INIS)

    Aoki, I.; Yamamoto, Y.; Takahashi, Saburo; Ooshima, Hirofumi; Kuniyasu, Kazufusa.

    1993-01-01

    In order to reduce a personal radiation exposure, Plutonium Fuel Production Facility (PFPF) introduced an automated MOX fabrication technology. Safeguards system for the PFPF was designed and installed so as to be compatible with automated process operation as much as possible. Introduction of these system in PFPF made possible to do the inspection measurements with unattended mode and Near Real Time Material Accountancy (NRTA), consequently inspection has been carrying out effectively and efficiently. This paper describes the new Inspection activities as a comparison with old Inspection activities based on our experience. (author)

  8. Base Oils Biodegradability Prediction with Data Mining Techniques

    Directory of Open Access Journals (Sweden)

    Malika Trabelsi

    2010-02-01

    Full Text Available In this paper, we apply various data mining techniques including continuous numeric and discrete classification prediction models of base oils biodegradability, with emphasis on improving prediction accuracy. The results show that highly biodegradable oils can be better predicted through numeric models. In contrast, classification models did not uncover a similar dichotomy. With the exception of Memory Based Reasoning and Decision Trees, tested classification techniques achieved high classification prediction. However, the technique of Decision Trees helped uncover the most significant predictors. A simple classification rule derived based on this predictor resulted in good classification accuracy. The application of this rule enables efficient classification of base oils into either low or high biodegradability classes with high accuracy. For the latter, a higher precision biodegradability prediction can be obtained using continuous modeling techniques.

  9. improvement of digital image watermarking techniques based on FPGA implementation

    International Nuclear Information System (INIS)

    EL-Hadedy, M.E

    2006-01-01

    digital watermarking provides the ownership of a piece of digital data by marking the considered data invisibly or visibly. this can be used to protect several types of multimedia objects such as audio, text, image and video. this thesis demonstrates the different types of watermarking techniques such as (discrete cosine transform (DCT) and discrete wavelet transform (DWT) and their characteristics. then, it classifies these techniques declaring their advantages and disadvantages. an improved technique with distinguished features, such as peak signal to noise ratio ( PSNR) and similarity ratio (SR) has been introduced. the modified technique has been compared with the other techniques by measuring heir robustness against differ attacks. finally, field programmable gate arrays (FPGA) based implementation and comparison, for the proposed watermarking technique have been presented and discussed

  10. Evaluation and improvement in nondestructive examination (NDE) reliability for inservice inspection of light water reactors

    International Nuclear Information System (INIS)

    Doctor, S.R.; Andersen, E.S.; Bowey, R.E.; Diaz, A.A.; Good, M.S.; Heasler, P.G.; Hockey, R.L.; Simonen, F.A.; Spanner, J.C.; Taylor, T.T.; Vo, T.V.

    1991-01-01

    This program is intended to establish the effectiveness, reliability and adequacy of inservice inspection of reactor pressure vessels and primary piping systems and the impact of ISI reliability on system integrity. The objectives of the program include: (a) determine the effectiveness and reliability of ultrasonic inservice inspection (ISI) performed on commercial, light water reactor pressure vessels and piping; (b) recommend Code changes to the inspection procedures to improve the reliability of ISI; (c) using fracture mechanics analysis, determine the impact of NDE unreliability on system safety and determine the level of inspection reliability required to assure a suitably low failure probability; (d) evaluate the degree of reliability improvement which could be achieved using improved NDE techniques; and (e) based on importance of component to safety, material properties, service conditions, and NDE uncertainties, formulate improved inservice inspection criteria (including sampling plan, frequency, and reliability of inspection) for revisions to ASME Section XI and regulatory requirements needed to assure suitably low failure probabilities

  11. Apparatus for inspecting a group of containers and method of using same

    Science.gov (United States)

    Lee, Jr., James H.; Salton, Jonathan R [Albuquerque, NM; Spletzer, Barry L [Albuquerque, NM

    2012-02-28

    An apparatus and method for inspecting a plurality of containers are provided. Each container has an outer surface for housing at least one material therein. The techniques provided involve at least one inspection vehicle and at least one detector. Each inspection vehicle has a plurality of wheels for movably positioning about the plurality of containers. The wheels may have at least one magnet for selectively adhering to the outer surface of at least one of the containers whereby the inspection vehicle traverses the container(s). The detector is positionable proximate at least one of the containers. The detector may be deployable from the inspection vehicle to a position adjacent the container(s). The detector has at least one sensor for measuring at least one characteristic of the plurality of containers. At least one base station may be provided for communicating with the inspection vehicle(s) and/or detector(s).

  12. Rapid analysis of steels using laser-based techniques

    International Nuclear Information System (INIS)

    Cremers, D.A.; Archuleta, F.L.; Dilworth, H.C.

    1985-01-01

    Based on the data obtained by this study, we conclude that laser-based techniques can be used to provide at least semi-quantitative information about the elemental composition of molten steel. Of the two techniques investigated here, the Sample-Only method appears preferable to the LIBS (laser-induced breakdown spectroscopy) method because of its superior analytical performance. In addition, the Sample-Only method would probably be easier to incorporate into a steel plant environment. However, before either technique can be applied to steel monitoring, additional research is needed

  13. Detailed simulation of ultrasonic inspections

    International Nuclear Information System (INIS)

    Chaplin, K.R.; Douglas, S.R.; Dunford, D.

    1997-01-01

    Simulation of ultrasonic inspection of engineering components have been performed at the Chalk River Laboratories of AECL for over 10 years. The computer model, called EWE for Elastic Wave Equations, solves the Elastic Wave Equations using a novel finite difference scheme. It simulates the propagation of an ultrasonic wave from the transducer to a flaw, the scatter of waves from the flaw, and measurement of signals at a receive transducer. Regions of different materials, water and steel for example, can be simulated. In addition, regions with slightly different material properties from the parent material can be investigated. The two major types of output are displays of the ultrasonic waves inside the component and the corresponding A-scans. EPRI and other organizations have used ultrasonic models for: defining acceptable ultrasonic inspection procedures, designing and evaluating inspection techniques, and for quantifying inspection reliability. The EWE model has been applied to the inspection of large pipes in a nuclear plant, gas pipeline welds and steam generator tubes. Most recent work has dealt with the ultrasonic inspection of pressure tubes in CANDU reactors. Pressure tube inspections can reliably detect and size defects; however, there are improvements that can be made. For example, knowing the sharpness of a flaw-tip is crucial for fitness for service assessments. Computer modelling of the ultrasonic inspection of flaws with different root radius has suggested inspection techniques that provide flaw tip radius information. A preliminary investigation of these methods has been made in the laboratory. The basis for the model will be reviewed at the presentation. Then the results of computer simulations will be displayed on a PC using an interactive program that analyzes simulated A-scans. This software tool gives inspection staff direct access to the results of computer simulations. (author)

  14. Experimental modeling of eddy current inspection capabilities

    International Nuclear Information System (INIS)

    Junker, W.R.; Clark, W.G.

    1984-01-01

    This chapter examines the experimental modeling of eddy current inspection capabilities based upon the use of liquid mercury samples designed to represent metal components containing discontinuities. A brief summary of past work with mercury modeling and a detailed discussion of recent experiments designed to further evaluate the technique are presented. The main disadvantages of the mercury modeling concept are that mercury is toxic and must be handled carefully, liquid mercury can only be used to represent nonferromagnetic materials, and wetting and meniscus problems can distort the effective size of artificial discontinuities. Artificial discontinuities placed in a liquid mercury sample can be used to represent discontinuities in solid metallic structures. Discontinuity size and type cannot be characterized from phase angle and signal amplitude data developed with a surface scanning, pancake-type eddy current probe. It is concluded that the mercury model approach can greatly enhance the overall understanding and applicability of eddy current inspection techniques

  15. Mobile X-ray inspection of light weight materials

    International Nuclear Information System (INIS)

    Ewert, Uwe; Redmer, Bernhard; Raedel, Christoph; Osterloh, Kurt; Schnars, Ulf; Henrich, Rudolf; Schimmelmann, Olaf; Bavendiek, Klaus; Jahn, Mirko

    2008-01-01

    Digital detectors such as phosphor imaging plates (IP) and digital detector arrays (DDA) allow radiographic inspection with higher efficiency and improved image quality in comparison to the classic film technique. Mobile X-ray flash tubes are used routinely for veterinarian and security applications. New high sensitive IPs and DDAs enable to apply them for inspection of light materials with low X-ray attenuation as in aluminium, plastics and composites. A versatile computed tomography (CT) system was developed for in situ inspection of large aircraft components under production conditions. A gate based planar computed tomograph was developed and tested for inspection of integrity of the stringer incorporation. Successful test trials were performed to prove the detection rate of cracks in embedded stringers. Honey comb structures of aircrafts have to be inspected for water inclusions during in-service inspections. Thermography is a powerful method for in house inspections when variations in temperature caused e.g. by sunshine can be excluded. A new X-ray diaphragm was developed for mobile back scatter measurements of large components. This method is insensitive to heat alterations in the field and thus can be applied also outdoors. (orig.)

  16. An innovative design for using flexible printed coils for magnetostrictive-based longitudinal guided wave sensors in steel strand inspection

    International Nuclear Information System (INIS)

    Tse, P W; Liu, X C; Wang, X J; Liu, Z H; Wu, B; He, C F

    2011-01-01

    Magnetostrictive sensors (MsSs) that can excite and receive guided waves are commonly used in detecting defects that may occur in cables and strands for supporting heavy structures. A conventional MsS has a hard sensing coil that is wound onto a bobbin with electric wires to generate the necessary dynamic magnetic field to excite the desired guided waves. This tailor-made hard coil is usually bulky and is not flexible enough to fit steel strands of various sizes. The conventional MsS also cannot be mounted to any steel strand that does not have a free end to allow the bobbin to pass through the structure of the tested strand. Such inflexibilities limit the use of conventional MsSs in practical situations. To solve these limitations, an innovative type of coil, called a flexible printed coil (FPC), which is made out of flexible printed film, has been designed to replace the inflexible hard coil. The flexible structure of the FPC ensures that the new MsS can be easily installed on and removed from steel strands with different diameters and without free ends. Moreover, the FPC-based MsS can be wrapped into multiple layers due to its thin and flexible design. Although multi-layer FPC creates a minor asymmetry in the dynamic magnetic field, the results of finite element analysis and experiments confirm that the longitudinal guided waves excited by a FPC-based MsS are comparable to those excited by a conventional hard coil MsS. No significant reduction in defect inspection performance was found; in fact, further advantages were identified when using the FPC-based MsS. When acting as the transmitter, the innovative FPC-based MsS can cover a longer inspection length of strand. When acting as the receiver, the FPC-based MsS is more sensitive to smaller defects that are impossible to detect using a hard coil MsS. Hence, the multi-layer FPC-based MsS has great potential for replacing the conventional hard coil MsS because of its convenient installation, and ease of fitting to

  17. Enabling inspection solutions for future mask technologies through the development of massively parallel E-Beam inspection

    Science.gov (United States)

    Malloy, Matt; Thiel, Brad; Bunday, Benjamin D.; Wurm, Stefan; Jindal, Vibhu; Mukhtar, Maseeh; Quoi, Kathy; Kemen, Thomas; Zeidler, Dirk; Eberle, Anna Lena; Garbowski, Tomasz; Dellemann, Gregor; Peters, Jan Hendrik

    2015-09-01

    The new device architectures and materials being introduced for sub-10nm manufacturing, combined with the complexity of multiple patterning and the need for improved hotspot detection strategies, have pushed current wafer inspection technologies to their limits. In parallel, gaps in mask inspection capability are growing as new generations of mask technologies are developed to support these sub-10nm wafer manufacturing requirements. In particular, the challenges associated with nanoimprint and extreme ultraviolet (EUV) mask inspection require new strategies that enable fast inspection at high sensitivity. The tradeoffs between sensitivity and throughput for optical and e-beam inspection are well understood. Optical inspection offers the highest throughput and is the current workhorse of the industry for both wafer and mask inspection. E-beam inspection offers the highest sensitivity but has historically lacked the throughput required for widespread adoption in the manufacturing environment. It is unlikely that continued incremental improvements to either technology will meet tomorrow's requirements, and therefore a new inspection technology approach is required; one that combines the high-throughput performance of optical with the high-sensitivity capabilities of e-beam inspection. To support the industry in meeting these challenges SUNY Poly SEMATECH has evaluated disruptive technologies that can meet the requirements for high volume manufacturing (HVM), for both the wafer fab [1] and the mask shop. Highspeed massively parallel e-beam defect inspection has been identified as the leading candidate for addressing the key gaps limiting today's patterned defect inspection techniques. As of late 2014 SUNY Poly SEMATECH completed a review, system analysis, and proof of concept evaluation of multiple e-beam technologies for defect inspection. A champion approach has been identified based on a multibeam technology from Carl Zeiss. This paper includes a discussion on the

  18. Clustering condition-based maintenance for a multi-unit system with aperiodic inspections

    NARCIS (Netherlands)

    Olde Keizer, Minou C.A.; Teunter, Ruud H.; Podofillini, Luca; Sudret, Bruno; Stojadinović, Božidar; Zio, Enrico; Kröger, Wolfgang

    2015-01-01

    Condition-Based Maintenance (CBM) is a predictive maintenance strategy, which bases the maintenance scheduling on condition measurements of the components. In this paper, we continue work on the CBM optimization approach proposed by Castanier, B., A. Grall & C. Bérenguer (2005). A condition-based

  19. Periodic inspections of the primary system

    International Nuclear Information System (INIS)

    Dufour, L.B.

    1978-01-01

    An impression is given of the inspection techniques, preparations and background for periodic examinations of the primary system of the Dodewaard Nuclear Reactor over the past 10 years. Unfortunately reliable integral inspection techniques to enable 'listening-in' to developing faults, are not yet available. Until they are, inspections will continue to be executed from a distance using different continuous methods, often under water and with a shortage of space and in the presence of ionising radiations. (C.F.)

  20. In-Line Acoustic Device Inspection of Leakage in Water Distribution Pipes Based on Wavelet and Neural Network

    Directory of Open Access Journals (Sweden)

    Dileep Kumar

    2017-01-01

    Full Text Available Traditionally permanent acoustic sensors leak detection techniques have been proven to be very effective in water distribution pipes. However, these methods need long distance deployment and proper position of sensors and cannot be implemented on underground pipelines. An inline-inspection acoustic device is developed which consists of acoustic sensors. The device will travel by the flow of water through the pipes which record all noise events and detect small leaks. However, it records all the noise events regarding background noises, but the time domain noisy acoustic signal cannot manifest complete features such as the leak flow rate which does not distinguish the leak signal and environmental disturbance. This paper presents an algorithm structure with the modularity of wavelet and neural network, which combines the capability of wavelet transform analyzing leakage signals and classification capability of artificial neural networks. This study validates that the time domain is not evident to the complete features regarding noisy leak signals and significance of selection of mother wavelet to extract the noise event features in water distribution pipes. The simulation consequences have shown that an appropriate mother wavelet has been selected and localized to extract the features of the signal with leak noise and background noise, and by neural network implementation, the method improves the classification performance of extracted features.

  1. Power system stabilizers based on modern control techniques

    Energy Technology Data Exchange (ETDEWEB)

    Malik, O P; Chen, G P; Zhang, Y; El-Metwally, K [Calgary Univ., AB (Canada). Dept. of Electrical and Computer Engineering

    1994-12-31

    Developments in digital technology have made it feasible to develop and implement improved controllers based on sophisticated control techniques. Power system stabilizers based on adaptive control, fuzzy logic and artificial networks are being developed. Each of these control techniques possesses unique features and strengths. In this paper, the relative performance of power systems stabilizers based on adaptive control, fuzzy logic and neural network, both in simulation studies and real time tests on a physical model of a power system, is presented and compared to that of a fixed parameter conventional power system stabilizer. (author) 16 refs., 45 figs., 3 tabs.

  2. Simulation-based optimization parametric optimization techniques and reinforcement learning

    CERN Document Server

    Gosavi, Abhijit

    2003-01-01

    Simulation-Based Optimization: Parametric Optimization Techniques and Reinforcement Learning introduces the evolving area of simulation-based optimization. The book's objective is two-fold: (1) It examines the mathematical governing principles of simulation-based optimization, thereby providing the reader with the ability to model relevant real-life problems using these techniques. (2) It outlines the computational technology underlying these methods. Taken together these two aspects demonstrate that the mathematical and computational methods discussed in this book do work. Broadly speaking, the book has two parts: (1) parametric (static) optimization and (2) control (dynamic) optimization. Some of the book's special features are: *An accessible introduction to reinforcement learning and parametric-optimization techniques. *A step-by-step description of several algorithms of simulation-based optimization. *A clear and simple introduction to the methodology of neural networks. *A gentle introduction to converg...

  3. An Image Registration Based Technique for Noninvasive Vascular Elastography

    OpenAIRE

    Valizadeh, Sina; Makkiabadi, Bahador; Mirbagheri, Alireza; Soozande, Mehdi; Manwar, Rayyan; Mozaffarzadeh, Moein; Nasiriavanaki, Mohammadreza

    2018-01-01

    Non-invasive vascular elastography is an emerging technique in vascular tissue imaging. During the past decades, several techniques have been suggested to estimate the tissue elasticity by measuring the displacement of the Carotid vessel wall. Cross correlation-based methods are the most prevalent approaches to measure the strain exerted in the wall vessel by the blood pressure. In the case of a low pressure, the displacement is too small to be apparent in ultrasound imaging, especially in th...

  4. Memory Based Machine Intelligence Techniques in VLSI hardware

    OpenAIRE

    James, Alex Pappachen

    2012-01-01

    We briefly introduce the memory based approaches to emulate machine intelligence in VLSI hardware, describing the challenges and advantages. Implementation of artificial intelligence techniques in VLSI hardware is a practical and difficult problem. Deep architectures, hierarchical temporal memories and memory networks are some of the contemporary approaches in this area of research. The techniques attempt to emulate low level intelligence tasks and aim at providing scalable solutions to high ...

  5. The Research of Histogram Enhancement Technique Based on Matlab Software

    Directory of Open Access Journals (Sweden)

    Li Kai

    2014-08-01

    Full Text Available Histogram enhancement technique has been widely applied as a typical pattern in digital image processing. The paper is based on Matlab software, through the two ways of histogram equalization and histogram specification technologies to deal with the darker images, using two methods of partial equilibrium and mapping histogram to transform the original histograms, thereby enhanced the image information. The results show that these two kinds of techniques both can significantly improve the image quality and enhance the image feature.

  6. Methodological aspects of a GIS-based environmental health inspection program used in the Athens 2004 Olympic and Para Olympic Games.

    Science.gov (United States)

    Hadjichristodoulou, Christos; Soteriades, Elpidoforos S; Kolonia, Virginia; Falagas, Matthew E; Pantelopoulos, Efstathios; Panagakos, Georgios; Mouchtouri, Varvara; Kremastinou, Jeni

    2005-09-02

    The use of geographical information system (GIS) technologies in public health surveillance is gradually gaining momentum around the world and many applications have already been reported in the literature. In this study, GIS technology was used to help county departments of Public Health to implement environmental health surveillance for the Athens 2004 Olympic and Para Olympic Games. In order to assess the workload in each Olympic county, 19 registry forms and 17 standardized inspection forms were developed to register and inspect environmental health items requiring inspection (Hotels, restaurants, swimming pools, water supply system etc), respectively. Furthermore, related databases were created using Epi Info 2002 and a geographical information system (GIS) were used to implement an integrated Environmental Health inspection program. The project was conducted in Athens by the Olympic Planning Unit (OPU) of the National School of Public Health, in close cooperation with the Ministry of Health and Social Solidarity and the corresponding departments of Public Health in all municipalities that were scheduled to host events during the Athens 2004 Olympic and Para Olympic games. A total of 44,741 premises of environmental health interest were geocoded into GIS databases and several electronic maps were developed. Using such maps in association with specific criteria, we first identified the maximum workload required to execute environmental health inspections in all premises within the eleven Olympic County Departments of Public Health. Six different scenarios were created for each county, based on devised algorithms in order to design the most effective and realistic inspection program using the available inspectors from each municipality. Furthermore, GIS applications were used to organize the daily inspection program for the Olympic games, provide coloured displays of the inspection results and link those results with the public health surveillance of specific

  7. Methodological aspects of a GIS-based environmental health inspection program used in the Athens 2004 Olympic and Para Olympic Games

    Directory of Open Access Journals (Sweden)

    Pantelopoulos Efstathios

    2005-09-01

    Full Text Available Abstract Background The use of geographical information system (GIS technologies in public health surveillance is gradually gaining momentum around the world and many applications have already been reported in the literature. In this study, GIS technology was used to help county departments of Public Health to implement environmental health surveillance for the Athens 2004 Olympic and Para Olympic Games. Methods In order to assess the workload in each Olympic county, 19 registry forms and 17 standardized inspection forms were developed to register and inspect environmental health items requiring inspection (Hotels, restaurants, swimming pools, water supply system etc, respectively. Furthermore, related databases were created using Epi Info 2002 and a geographical information system (GIS were used to implement an integrated Environmental Health inspection program. The project was conducted in Athens by the Olympic Planning Unit (OPU of the National School of Public Health, in close cooperation with the Ministry of Health and Social Solidarity and the corresponding departments of Public Health in all municipalities that were scheduled to host events during the Athens 2004 Olympic and Para Olympic games. Results A total of 44,741 premises of environmental health interest were geocoded into GIS databases and several electronic maps were developed. Using such maps in association with specific criteria, we first identified the maximum workload required to execute environmental health inspections in all premises within the eleven Olympic County Departments of Public Health. Six different scenarios were created for each county, based on devised algorithms in order to design the most effective and realistic inspection program using the available inspectors from each municipality. Furthermore, GIS applications were used to organize the daily inspection program for the Olympic games, provide coloured displays of the inspection results and link those

  8. Generic data base for security equipment and its utility in the safeguards inspection process. Final report 8151-79-FR-16

    International Nuclear Information System (INIS)

    Scala, S.

    1979-01-01

    This report contains material presented at the Nuclear Regulatory Commission (NRC) conference of regional inspectors in Atlanta, Georgia, on January 17, 1979. It describes the contents of the generic data base for security equipment, which was developed by SRI for NRC under a Sandia Laboratories' subcontract, and examines its potential utility in the process of inspection of NRC-licensed facilities

  9. Thermal Texture Selection and Correction for Building Facade Inspection Based on Thermal Radiant Characteristics

    Science.gov (United States)

    Lin, D.; Jarzabek-Rychard, M.; Schneider, D.; Maas, H.-G.

    2018-05-01

    An automatic building façade thermal texture mapping approach, using uncooled thermal camera data, is proposed in this paper. First, a shutter-less radiometric thermal camera calibration method is implemented to remove the large offset deviations caused by changing ambient environment. Then, a 3D façade model is generated from a RGB image sequence using structure-from-motion (SfM) techniques. Subsequently, for each triangle in the 3D model, the optimal texture is selected by taking into consideration local image scale, object incident angle, image viewing angle as well as occlusions. Afterwards, the selected textures can be further corrected using thermal radiant characteristics. Finally, the Gauss filter outperforms the voted texture strategy at the seams smoothing and thus for instance helping to reduce the false alarm rate in façade thermal leakages detection. Our approach is evaluated on a building row façade located at Dresden, Germany.

  10. Terahertz Radome Inspection

    Directory of Open Access Journals (Sweden)

    Fabian Friederich

    2018-01-01

    Full Text Available Radomes protecting sensitive radar, navigational, and communications equipment of, e.g., aircraft, are strongly exposed to the environment and have to withstand harsh weather conditions and potential impacts. Besides their significance to the structural integrity of the radomes, it is often crucial to optimize the composite structures for best possible radio performance. Hence, there exists a significant interest in non-destructive testing techniques, which can be used for defect inspection of radomes in field use as well as for quality inspection during the manufacturing process. Contactless millimeter-wave and terahertz imaging techniques provide millimeter resolution and have the potential to address both application scenarios. We report on our development of a three-dimensional (3D terahertz imaging system for radome inspection during industrial manufacturing processes. The system was designed for operation within a machining center for radome manufacturing. It simultaneously gathers terahertz depth information in adjacent frequency ranges, from 70 to 110 GHz and from 110 to 170 GHz by combining two frequency modulated continuous-wave terahertz sensing units into a single measurement device. Results from spiraliform image acquisition of a radome test sample demonstrate the successful integration of the measurement system.

  11. Fuel assembly inspection device

    International Nuclear Information System (INIS)

    Yaginuma, Yoshitaka

    1998-01-01

    The present invention provides a device suitable to inspect appearance of fuel assemblies by photographing the appearance of fuel assemblies. Namely, the inspection device of the present invention measures bowing of fuel assembly or each of fuel rods or both of them based on the partially photographed images of fuel assembly. In this case, there is disposed a means which flashily projects images in the form of horizontal line from a direction intersecting obliquely relative to a horizontal cross section of the fuel assembly. A first image processing means separates the projected image pictures including projected images and calculates bowing. A second image processing means replaces the projected image pictures of the projected images based on projected images just before and after the photographing. Then, images for the measurement of bowing and images for inspection can be obtained simultaneously. As a result, the time required for the photographing can be shortened, the time for inspection can be shortened and an effect of preventing deterioration of photographing means by radiation rays can be provided. (I.S.)

  12. Laser-based direct-write techniques for cell printing

    Energy Technology Data Exchange (ETDEWEB)

    Schiele, Nathan R; Corr, David T [Biomedical Engineering Department, Rensselaer Polytechnic Institute, Troy, NY (United States); Huang Yong [Department of Mechanical Engineering, Clemson University, Clemson, SC (United States); Raof, Nurazhani Abdul; Xie Yubing [College of Nanoscale Science and Engineering, University at Albany, SUNY, Albany, NY (United States); Chrisey, Douglas B, E-mail: schien@rpi.ed, E-mail: chrisd@rpi.ed [Material Science and Engineering Department, Rensselaer Polytechnic Institute, Troy, NY (United States)

    2010-09-15

    Fabrication of cellular constructs with spatial control of cell location ({+-}5 {mu}m) is essential to the advancement of a wide range of applications including tissue engineering, stem cell and cancer research. Precise cell placement, especially of multiple cell types in co- or multi-cultures and in three dimensions, can enable research possibilities otherwise impossible, such as the cell-by-cell assembly of complex cellular constructs. Laser-based direct writing, a printing technique first utilized in electronics applications, has been adapted to transfer living cells and other biological materials (e.g., enzymes, proteins and bioceramics). Many different cell types have been printed using laser-based direct writing, and this technique offers significant improvements when compared to conventional cell patterning techniques. The predominance of work to date has not been in application of the technique, but rather focused on demonstrating the ability of direct writing to pattern living cells, in a spatially precise manner, while maintaining cellular viability. This paper reviews laser-based additive direct-write techniques for cell printing, and the various cell types successfully laser direct-written that have applications in tissue engineering, stem cell and cancer research are highlighted. A particular focus is paid to process dynamics modeling and process-induced cell injury during laser-based cell direct writing. (topical review)

  13. Laser-based direct-write techniques for cell printing

    International Nuclear Information System (INIS)

    Schiele, Nathan R; Corr, David T; Huang Yong; Raof, Nurazhani Abdul; Xie Yubing; Chrisey, Douglas B

    2010-01-01

    Fabrication of cellular constructs with spatial control of cell location (±5 μm) is essential to the advancement of a wide range of applications including tissue engineering, stem cell and cancer research. Precise cell placement, especially of multiple cell types in co- or multi-cultures and in three dimensions, can enable research possibilities otherwise impossible, such as the cell-by-cell assembly of complex cellular constructs. Laser-based direct writing, a printing technique first utilized in electronics applications, has been adapted to transfer living cells and other biological materials (e.g., enzymes, proteins and bioceramics). Many different cell types have been printed using laser-based direct writing, and this technique offers significant improvements when compared to conventional cell patterning techniques. The predominance of work to date has not been in application of the technique, but rather focused on demonstrating the ability of direct writing to pattern living cells, in a spatially precise manner, while maintaining cellular viability. This paper reviews laser-based additive direct-write techniques for cell printing, and the various cell types successfully laser direct-written that have applications in tissue engineering, stem cell and cancer research are highlighted. A particular focus is paid to process dynamics modeling and process-induced cell injury during laser-based cell direct writing. (topical review)

  14. A novel lobster-eye imaging system based on Schmidt-type objective for X-ray-backscattering inspection

    International Nuclear Information System (INIS)

    Xu, Jie; Wang, Xin; Zhan, Qi; Huang, Shengling; Chen, Yifan; Mu, Baozhong

    2016-01-01

    This paper presents a novel lobster-eye imaging system for X-ray-backscattering inspection. The system was designed by modifying the Schmidt geometry into a treble-lens structure in order to reduce the resolution difference between the vertical and horizontal directions, as indicated by ray-tracing simulations. The lobster-eye X-ray imaging system is capable of operating over a wide range of photon energies up to 100 keV. In addition, the optics of the lobster-eye X-ray imaging system was tested to verify that they meet the requirements. X-ray-backscattering imaging experiments were performed in which T-shaped polymethyl-methacrylate objects were imaged by the lobster-eye X-ray imaging system based on both the double-lens and treble-lens Schmidt objectives. The results show similar resolution of the treble-lens Schmidt objective in both the vertical and horizontal directions. Moreover, imaging experiments were performed using a second treble-lens Schmidt objective with higher resolution. The results show that for a field of view of over 200 mm and with a 500 mm object distance, this lobster-eye X-ray imaging system based on a treble-lens Schmidt objective offers a spatial resolution of approximately 3 mm.

  15. An Algorithm for Inspecting Self Check-in Airline Luggage Based on Hierarchical Clustering and Cube-fitting

    Directory of Open Access Journals (Sweden)

    Gao Qingji

    2014-04-01

    Full Text Available Airport passengers are required to put only one baggage each time in the check-in self-service so that the baggage can be detected and identified successfully. In order to automatically get the number of baggage that had been put on the conveyor belt, dual laser rangefinders are used to scan the outer contour of luggage in this paper. The algorithm based on hierarchical clustering and cube-fitting is proposed to inspect the number and dimension of airline luggage. Firstly, the point cloud is projected to vertical direction. By the analysis of one-dimensional clustering, the number and height of luggage will be quickly computed. Secondly, the method of nearest hierarchical clustering is applied to divide the point cloud if the above cannot be distinguished. It can preferably solve the difficult issue like crossing or overlapping pieces of baggage. Finally, the point cloud is projected to the horizontal plane. By rotating point cloud based on the centre, its minimum bounding rectangle (MBR is obtained. The length and width of luggage are got form MBR. Many experiments in different cases have been done to verify the effectiveness of the algorithm.

  16. Collaborative Video Search Combining Video Retrieval with Human-Based Visual Inspection

    NARCIS (Netherlands)

    Hudelist, M.A.; Cobârzan, C.; Beecks, C.; van de Werken, Rob; Kletz, S.; Hürst, W.O.; Schoeffmann, K.

    2016-01-01

    We propose a novel video browsing approach that aims at optimally integrating traditional, machine-based retrieval methods with an interface design optimized for human browsing performance. Advanced video retrieval and filtering (e.g., via color and motion signatures, and visual concepts) on a

  17. A Novel Web-based Approach for Visualization and Inspection of Reading Difficulties on University Students

    DEFF Research Database (Denmark)

    Mejia, Carolina; Florian-Gaviria, Beatriz; Vatrapu, Ravi

    2017-01-01

    reading difficulties and their characteristics, called PADA (acronym for the Spanish name Panel de Analíticas de Aprendizaje de Dislexia en Adultos), is presented. PADA is a web-based tool designed to facilitate the creation of descriptive visualizations required for a better understanding of students...

  18. Waste Inspection Tomography (WIT)

    International Nuclear Information System (INIS)

    Bernardi, R.T.

    1995-01-01

    Waste Inspection Tomography (WIT) provides mobile semi-trailer mounted nondestructive examination (NDE) and assay (NDA) for nuclear waste drum characterization. WIT uses various computed tomography (CT) methods for both NDE and NDA of nuclear waste drums. Low level waste (LLW), transuranic (TRU), and mixed radioactive waste can be inspected and characterized without opening the drums. With externally transmitted x-ray NDE techniques, WIT has the ability to identify high density waste materials like heavy metals, define drum contents in two- and three-dimensional space, quantify free liquid volumes through density and x-ray attenuation coefficient discrimination, and measure drum wall thickness. With waste emitting gamma-ray NDA techniques, WIT can locate gamma emitting radioactive sources in two- and three-dimensional space, identify gamma emitting isotopic species, identify the external activity levels of emitting gamma-ray sources, correct for waste matrix attenuation, provide internal activity approximations, and provide the data needed for waste classification as LLW or TRU. The mobile feature of WIT allows inspection technologies to be brought to the nuclear waste drum storage site without the need to relocate drums for safe, rapid, and cost-effective characterization of regulated nuclear waste. The combination of these WIT characterization modalities provides the inspector with an unprecedented ability to non-invasively characterize the regulated contents of waste drums as large as 110 gallons, weighing up to 1,600 pounds. Any objects that fit within these size and weight restrictions can also be inspected on WIT, such as smaller waste bags and drums that are five and thirty-five gallons

  19. Remote inspection system for nuclear power plants

    International Nuclear Information System (INIS)

    Inagaki, K.; Fujii, M.; Doi, A.; Harima, T.

    1977-01-01

    A remote inspection system for nuclear power plants was constructed based on an analysis of inspections performed by an operator on patrol. This system consists of an operator's console and a remote station. The remote station, equipped with five kinds of sensors, is steered along the inspection route by a photoelectric guiding system or may be manually controlled from an operator's console in a main control room. Signals for control and inspection data are multiplexed and transmitted through a coaxial cable

  20. Spectroradiometric inspection of nuclear pollution in the atmosphere based on photochemical effects

    Science.gov (United States)

    Chistyakova, Liliya K.; Kopytin, Yurii D.

    2005-07-01

    Results of theoretical and experimental investigations of remote monitoring methods based on secondary radioactivity effects including anomalous gaseous fields and their emissions in optical and microwave ranges are discussed. The feasibility of remote registration of secondary emission and absorption spectra from weakly ionized regions in the atmosphere above nuclear power engineering objects, dumps, and tailings dumps of nuclear wastes are examined. Based on the literature data on the excess concentrations of aerosol and gaseous components produced in radiation fields above their background levels, the diffusion parameters of radioactive emissions in the atmosphere are evaluated. The methods under consideration are shown to be promising for ecological monitoring of atmospheric radioactive pollution. High sensitivities of these methods enable pollutants to be detected at long distances. Simultaneous use of passive and active methods gives additional information on the parameters of radioactive pollution.

  1. Robotic inspection of fiber reinforced composites using phased array UT

    Science.gov (United States)

    Stetson, Jeffrey T.; De Odorico, Walter

    2014-02-01

    Ultrasound is the current NDE method of choice to inspect large fiber reinforced airframe structures. Over the last 15 years Cartesian based scanning machines using conventional ultrasound techniques have been employed by all airframe OEMs and their top tier suppliers to perform these inspections. Technical advances in both computing power and commercially available, multi-axis robots now facilitate a new generation of scanning machines. These machines use multiple end effector tools taking full advantage of phased array ultrasound technologies yielding substantial improvements in inspection quality and productivity. This paper outlines the general architecture for these new robotic scanning systems as well as details the variety of ultrasonic techniques available for use with them including advances such as wide area phased array scanning and sound field adaptation for non-flat, non-parallel surfaces.

  2. Estimate-Merge-Technique-based algorithms to track an underwater ...

    Indian Academy of Sciences (India)

    D V A N Ravi Kumar

    2017-07-04

    Jul 4, 2017 ... In this paper, two novel methods based on the Estimate Merge Technique ... mentioned advantages of the proposed novel methods is shown by carrying out Monte Carlo simulation in .... equations are converted to sequential equations to make ... estimation error and low convergence time) at feasibly high.

  3. GIS-Based bivariate statistical techniques for groundwater potential ...

    Indian Academy of Sciences (India)

    24

    This study shows the potency of two GIS-based data driven bivariate techniques namely ... In the view of these weaknesses , there is a strong requirement for reassessment of .... Font color: Text 1, Not Expanded by / Condensed by , ...... West Bengal (India) using remote sensing, geographical information system and multi-.

  4. Learning Physics through Project-Based Learning Game Techniques

    Science.gov (United States)

    Baran, Medine; Maskan, Abdulkadir; Yasar, Seyma

    2018-01-01

    The aim of the present study, in which Project and game techniques are used together, is to examine the impact of project-based learning games on students' physics achievement. Participants of the study consist of 34 9th grade students (N = 34). The data were collected using achievement tests and a questionnaire. Throughout the applications, the…

  5. Inspection of dissimilar metal welds in reactor pressure vessels in Spain

    Energy Technology Data Exchange (ETDEWEB)

    Gadea, J.R.; Regidor, J.J.; Pelaez, J.A.; Serrano, P. [Tecnatom, S.A., San Sebastian de los Reyes, Madrid (Spain)

    2011-07-01

    MRP-139 recommendations for inspection of dissimilar metal (DM) welds in PWR vessels were launched in the last years in the USA. Basically, it increases the frequency of the examinations in these type of welds, with major emphasis in the hot loops, adding one intermediate inspection at the ten years interval in outlet nozzles. The spanish nuclear power plants (NPP's) have begun the implementation of this type of inspections on the vessel nozzles DM welds. As this type of inspections could have an impact in the critical path duration of the outage, it is necessary the use of a mechanical equipment able to examine the nozzles DM welds in a short vessel occupation time (VOT) with high quality, qualified techniques and minimum requirements of the refuelling platform. Tecnatom undertook the design and development of a new more advanced equipment, named TENIS-DM, for implementing the reactor pressure vessel (RPV) nozzles examination. This equipment was designed in order to accomplish the stringent requirements and the updated examination techniques; it was used for the inspection of the DM welds of Asco 1 NPP inlet and outlet nozzles in March 2011. Examination techniques and procedures were qualified through the GRUVAL validation program, based on ENIC methodology. Mechanical scanner was equipped with a large number of examination probes, and TV cameras -for visual inspection and also for monitoring the ultrasonic inspections. A remote operated submarine was also used to give support to the operational personnel during the manipulation of the equipment and its movements from one nozzle to the others. During two months before the inspection, tests of the complete inspection system were made on a nozzle mock-up installed in a 4 meters deep well at Tecnatom's facilities; this scenario was also used during the training sessions of the inspection crew. The defined technical and practical objectives were achieved: use of qualified techniques and minimal impact on the

  6. Inspection of dissimilar metal welds in reactor pressure vessels in Spain

    International Nuclear Information System (INIS)

    Gadea, J.R.; Regidor, J.J.; Pelaez, J.A.; Serrano, P.

    2011-01-01

    MRP-139 recommendations for inspection of dissimilar metal (DM) welds in PWR vessels were launched in the last years in the USA. Basically, it increases the frequency of the examinations in these type of welds, with major emphasis in the hot loops, adding one intermediate inspection at the ten years interval in outlet nozzles. The spanish nuclear power plants (NPP's) have begun the implementation of this type of inspections on the vessel nozzles DM welds. As this type of inspections could have an impact in the critical path duration of the outage, it is necessary the use of a mechanical equipment able to examine the nozzles DM welds in a short vessel occupation time (VOT) with high quality, qualified techniques and minimum requirements of the refuelling platform. Tecnatom undertook the design and development of a new more advanced equipment, named TENIS-DM, for implementing the reactor pressure vessel (RPV) nozzles examination. This equipment was designed in order to accomplish the stringent requirements and the updated examination techniques; it was used for the inspection of the DM welds of Asco 1 NPP inlet and outlet nozzles in March 2011. Examination techniques and procedures were qualified through the GRUVAL validation program, based on ENIC methodology. Mechanical scanner was equipped with a large number of examination probes, and TV cameras -for visual inspection and also for monitoring the ultrasonic inspections. A remote operated submarine was also used to give support to the operational personnel during the manipulation of the equipment and its movements from one nozzle to the others. During two months before the inspection, tests of the complete inspection system were made on a nozzle mock-up installed in a 4 meters deep well at Tecnatom's facilities; this scenario was also used during the training sessions of the inspection crew. The defined technical and practical objectives were achieved: use of qualified techniques and minimal impact on the critical

  7. Heuristic evaluation of paper-based Web pages: a simplified inspection usability methodology.

    Science.gov (United States)

    Allen, Mureen; Currie, Leanne M; Bakken, Suzanne; Patel, Vimla L; Cimino, James J

    2006-08-01

    Online medical information, when presented to clinicians, must be well-organized and intuitive to use, so that the clinicians can conduct their daily work efficiently and without error. It is essential to actively seek to produce good user interfaces that are acceptable to the user. This paper describes the methodology used to develop a simplified heuristic evaluation (HE) suitable for the evaluation of screen shots of Web pages, the development of an HE instrument used to conduct the evaluation, and the results of the evaluation of the aforementioned screen shots. In addition, this paper presents examples of the process of categorizing problems identified by the HE and the technological solutions identified to resolve these problems. Four usability experts reviewed 18 paper-based screen shots and made a total of 108 comments. Each expert completed the task in about an hour. We were able to implement solutions to approximately 70% of the violations. Our study found that a heuristic evaluation using paper-based screen shots of a user interface was expeditious, inexpensive, and straightforward to implement.

  8. Ultrabroadband Phased-Array Receivers Based on Optical Techniques

    Science.gov (United States)

    2016-02-26

    bandwidths, and with it receiver noise floors , are unavoidable. Figure 1. SNR of a thermally limited receiver based on Friis equation showing the...techniques for RF and photonic integration based on liquid crystal polymer substrates were pursued that would aid in the realization of potential imaging...These models assumed that sufficient LNA gain was used on the antenna to set the noise floor of the imaging receiver, which necessitated physical

  9. Ultrasonic inspection of austenitic welds

    Energy Technology Data Exchange (ETDEWEB)

    Tomlinson, J R; Wagg, A R; Whittle, M J [N.D.T. Applications Centre, CEGB, Manchester (United Kingdom)

    1980-11-01

    The metallurgical structure of austenitic welds is described and contrasted with that found in ferritic welds. It is shown that this structure imparts a marked elastic anisotropy in the ultrasonic propagation parameters. Measurements of variations in the apparent attenuation of sound and deviations in the beam direction are described. The measurements are interpreted in terms of the measured velocity anisotropy. Two applications of the fundamental work are described. In the first it is shown how, by using short pulse compression wave probes, and with major modification of the welding procedure, a stainless steel fillet weld in an AGR boiler can be inspected. In the second application, alternative designs of a transition butt weld have been compared for ease of ultrasonic inspection. The effects of two different welding processes on such an inspection are described. Finally, the paper examines the prospects for future development of inspection and defect-sizing techniques for austenitic welds. (author)

  10. Analisis Remaining Life dan Penjadwalan Program Inspeksi pada Pressure Vessel dengan Menggunakan Metode Risk Based Inspection (RBI

    Directory of Open Access Journals (Sweden)

    Dyah Arina Wahyu Lillah

    2017-01-01

    Full Text Available Seiring perkembangan eksplorasi minyak dan gas bumi di dunia, perusahaan minyak dan gas di Indonesia juga turut berlomba-lomba untuk mendapatkan ladang minyak dan gas bumi sebanyak-banyaknya. Perkembangan ini turut dipengaruhi oleh aturan-aturan pemerintah mengenai keselamatan dan pencegahan bahaya baik pada unit yang dikelola maupun tenaga kerja pengelola. Untuk itu semua perlatan-peralatan (unit kerja harus dijamin kehandalaannya agar tidak menimbulkan bahaya baik bagi pekerja maupun lingkungan. Subjek penelitian dalam tugas akhir ini ialah pada pressure vessel yang dimiliki oleh Terminal LPG Semarang. Kemungkinan bahaya yang dapat menyebabkan kerusakan pada pressure vessel perlu dianalisis agar dapat meminimalkan resiko yang akan terjadi. Metode Risk Based Inspection (RBI diharapkan dapat meminimalkan resiko yang ada pada pressure vessel. Penilaian resiko dalam tugas akhir ini mengacu pada standar API RP 581. Untuk mengetahui besarnya resiko yang ada pada plant, maka terlebih dahulu harus dihitung besarnya probabilitas kegagalan dan konsekuensi apabila terjadi kegagalan. Langkah selanjutnya ialah membandingkan besarnya resiko yang didapat dengan target resiko yang dimiliki oleh perusahaan. Dari hasil perbandingan ini dapat diketahui tingkat resiko pressure vessel, sehingga dapat ditentukan jadwal inspeksi dan metode inspeksi yang tepat.

  11. The development of PC-based real time ultrasonic metal thickness inspection system

    International Nuclear Information System (INIS)

    Suhairy Sani; Mohd Hanif Md Saad; Mohamad Pauzi Ismail; Ab Razak Hamzah; Abd Nassir Ibrahim; Amri Amin Abas

    2006-01-01

    This paper discusses the development of a PC-Based Real Time Ultrasonic Thickness Measurement system (UTMS) for metallic components such as pipes, pressure vessels and metal slabs. Metal thickness measurement for these components is crucial in industrial plants with dangerous environment, such as in oil and gas industry. From the measured metal thickness, a number of deductions could be made, for example the state and the rate of corrosion propagation inside a pipe or pressure vessel, etc. One of the most widely used methods in assessing metal thickness in industry is through the use of Ultrasonic technology. The benefits of using UTMS lies in the flexibility of data analysis, which includes signal processing, feature extraction, visualization capability and intelligent diagnosis. Data can be acquired in real-time and stored for future usage and application. The system was developed as a standalone computer software using Microsoft Visual-BASIC 6. (Author)

  12. Optical supervised filtering technique based on Hopfield neural network

    Science.gov (United States)

    Bal, Abdullah

    2004-11-01

    Hopfield neural network is commonly preferred for optimization problems. In image segmentation, conventional Hopfield neural networks (HNN) are formulated as a cost-function-minimization problem to perform gray level thresholding on the image histogram or the pixels' gray levels arranged in a one-dimensional array [R. Sammouda, N. Niki, H. Nishitani, Pattern Rec. 30 (1997) 921-927; K.S. Cheng, J.S. Lin, C.W. Mao, IEEE Trans. Med. Imag. 15 (1996) 560-567; C. Chang, P. Chung, Image and Vision comp. 19 (2001) 669-678]. In this paper, a new high speed supervised filtering technique is proposed for image feature extraction and enhancement problems by modifying the conventional HNN. The essential improvement in this technique is to use 2D convolution operation instead of weight-matrix multiplication. Thereby, neural network based a new filtering technique has been obtained that is required just 3 × 3 sized filter mask matrix instead of large size weight coefficient matrix. Optical implementation of the proposed filtering technique is executed easily using the joint transform correlator. The requirement of non-negative data for optical implementation is provided by bias technique to convert the bipolar data to non-negative data. Simulation results of the proposed optical supervised filtering technique are reported for various feature extraction problems such as edge detection, corner detection, horizontal and vertical line extraction, and fingerprint enhancement.

  13. Video Multiple Watermarking Technique Based on Image Interlacing Using DWT

    Directory of Open Access Journals (Sweden)

    Mohamed M. Ibrahim

    2014-01-01

    Full Text Available Digital watermarking is one of the important techniques to secure digital media files in the domains of data authentication and copyright protection. In the nonblind watermarking systems, the need of the original host file in the watermark recovery operation makes an overhead over the system resources, doubles memory capacity, and doubles communications bandwidth. In this paper, a robust video multiple watermarking technique is proposed to solve this problem. This technique is based on image interlacing. In this technique, three-level discrete wavelet transform (DWT is used as a watermark embedding/extracting domain, Arnold transform is used as a watermark encryption/decryption method, and different types of media (gray image, color image, and video are used as watermarks. The robustness of this technique is tested by applying different types of attacks such as: geometric, noising, format-compression, and image-processing attacks. The simulation results show the effectiveness and good performance of the proposed technique in saving system resources, memory capacity, and communications bandwidth.

  14. Video multiple watermarking technique based on image interlacing using DWT.

    Science.gov (United States)

    Ibrahim, Mohamed M; Abdel Kader, Neamat S; Zorkany, M

    2014-01-01

    Digital watermarking is one of the important techniques to secure digital media files in the domains of data authentication and copyright protection. In the nonblind watermarking systems, the need of the original host file in the watermark recovery operation makes an overhead over the system resources, doubles memory capacity, and doubles communications bandwidth. In this paper, a robust video multiple watermarking technique is proposed to solve this problem. This technique is based on image interlacing. In this technique, three-level discrete wavelet transform (DWT) is used as a watermark embedding/extracting domain, Arnold transform is used as a watermark encryption/decryption method, and different types of media (gray image, color image, and video) are used as watermarks. The robustness of this technique is tested by applying different types of attacks such as: geometric, noising, format-compression, and image-processing attacks. The simulation results show the effectiveness and good performance of the proposed technique in saving system resources, memory capacity, and communications bandwidth.

  15. Cassette-based in-situ TEM sample inspection in the dual-beam FIB

    International Nuclear Information System (INIS)

    Kendrick, A B; Moore, T M; Zaykova-Feldman, L; Amador, G; Hammer, M

    2008-01-01

    A novel method is presented, combining site-specific TEM sample preparation and in-situ STEM analysis in a dual-beam microscope (FIB/SEM) fitted with a chamber mounted nano-manipulator. TEM samples are prepared using a modified in-situ, lift-out method, whereby the samples are thinned and oriented for immediate in-situ STEM analysis using the tilt, translation, and rotation capabilities of a FIB/SEM sample stage, a nano-manipulator, and a novel cassette. This cassette can provide a second tilt axis, orthogonal to the stage tilt axis, so that the STEM image contrast can be optimized to reveal the structural features of the sample (true STEM imaging in the FIB/SEM). The angles necessary for stage rotation and probe shaft rotation are calculated based on the position of the nano-manipulator relative to the stage and door and the stage tilt angle. A FIB/SEM instrument, equipped with a high resolution scanning electron column, can provide sufficiently high image resolution to enable many failure analysis and process control applications to be successfully carried out without requiring the use of a separate dedicated TEM/STEM instrument. The benefits of this novel approach are increased throughput and reduced cost per sample. Comparative analysis of different sample preparation methods is provided, and the STEM images obtained are shown.

  16. Line impedance estimation using model based identification technique

    DEFF Research Database (Denmark)

    Ciobotaru, Mihai; Agelidis, Vassilios; Teodorescu, Remus

    2011-01-01

    The estimation of the line impedance can be used by the control of numerous grid-connected systems, such as active filters, islanding detection techniques, non-linear current controllers, detection of the on/off grid operation mode. Therefore, estimating the line impedance can add extra functions...... into the operation of the grid-connected power converters. This paper describes a quasi passive method for estimating the line impedance of the distribution electricity network. The method uses the model based identification technique to obtain the resistive and inductive parts of the line impedance. The quasi...

  17. Biometric image enhancement using decision rule based image fusion techniques

    Science.gov (United States)

    Sagayee, G. Mary Amirtha; Arumugam, S.

    2010-02-01

    Introducing biometrics into information systems may result in considerable benefits. Most of the researchers confirmed that the finger print is widely used than the iris or face and more over it is the primary choice for most privacy concerned applications. For finger prints applications, choosing proper sensor is at risk. The proposed work deals about, how the image quality can be improved by introducing image fusion technique at sensor levels. The results of the images after introducing the decision rule based image fusion technique are evaluated and analyzed with its entropy levels and root mean square error.

  18. Electromagnetism based atmospheric ice sensing technique - A conceptual review

    Directory of Open Access Journals (Sweden)

    U Mughal

    2016-09-01

    Full Text Available Electromagnetic and vibrational properties of ice can be used to measure certain parameters such as ice thickness, type and icing rate. In this paper we present a review of the dielectric based measurement techniques for matter and the dielectric/spectroscopic properties of ice. Atmospheric Ice is a complex material with a variable dielectric constant, but precise calculation of this constant may form the basis for measurement of its other properties such as thickness and strength using some electromagnetic methods. Using time domain or frequency domain spectroscopic techniques, by measuring both the reflection and transmission characteristics of atmospheric ice in a particular frequency range, the desired parameters can be determined.

  19. Proposing a Wiki-Based Technique for Collaborative Essay Writing

    Directory of Open Access Journals (Sweden)

    Mabel Ortiz Navarrete

    2014-10-01

    Full Text Available This paper aims at proposing a technique for students learning English as a foreign language when they collaboratively write an argumentative essay in a wiki environment. A wiki environment and collaborative work play an important role within the academic writing task. Nevertheless, an appropriate and systematic work assignment is required in order to make use of both. In this paper the proposed technique when writing a collaborative essay mainly attempts to provide the most effective way to enhance equal participation among group members by taking as a base computer mediated collaboration. Within this context, the students’ role is clearly defined and individual and collaborative tasks are explained.

  20. Knowledge based systems advanced concepts, techniques and applications

    CERN Document Server

    1997-01-01

    The field of knowledge-based systems (KBS) has expanded enormously during the last years, and many important techniques and tools are currently available. Applications of KBS range from medicine to engineering and aerospace.This book provides a selected set of state-of-the-art contributions that present advanced techniques, tools and applications. These contributions have been prepared by a group of eminent researchers and professionals in the field.The theoretical topics covered include: knowledge acquisition, machine learning, genetic algorithms, knowledge management and processing under unc